Field of the Invention
[0001] The present invention relates to silicone hydrogels having an exceptional balance
of properties which are generated by controlling the reaction kinetics of the components
of the reaction mixture.
Background of the Invention
[0002] Soft contact lenses made from silicone hydrogels offer improved oxygen permeability
as compared to soft lenses made from non-silicone materials such as poly(2-hydroxyethyl
methacrylate) (HEMA). Initial efforts to make silicone hydrogel contact lenses were
hampered by the poor wettability, high modulus, poor clarity, hydrolytic instability
or the high cost of raw materials used to make many of these silicone hydrogels. While
various solutions have proven somewhat successful for each of these deficiencies,
there remains a need for silicone hydrogels that can be made from inexpensive commercially
available monomers, and which have excellent wettability (without the need for surface
modification), low modulus, good clarity, and desirable oxygen permeability.
[0003] Silicone hydrogels formulations containing polymeric wetting agents, such as poly(N-vinylpyrrolidone)
(PVP) and acyclic polyamides have been disclosed. However, these polymers are quite
large and require the use of special compatibilizing components, which need to be
custom manufactured. Examples of compatibilizing components include 2-propenoic acid,
2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propyl
ester (SiGMA).
[0004] An alternative means of forming a wettable silicone hydrogel lens is to incorporate
monomeric N-vinylpyrrolidone (NVP) into the monomer mix used to make the silicone
hydrogel polymer, typically in amounts of about 25-55% (by weight) of the monomer
mix. Such materials have been described in
US patents 4,136,250;
4,153,641;
4,260,725 and
6,867,245. The materials described in these references generally incorporate polyfunctional
silicone monomers or macromers, that act as crosslinking agents, and thereby increase
the modulus of the final polymer.
US 4,139,513 discloses that 2-propenoic acid, 2-methyl-,2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propyl
ester (SiGMA) can be used to form lenses from formulations comprising NVP and HEMA.
SiGMA is the only source of silicone disclosed. However, because of the relatively
low silicone content in those monomers, desirable levels of oxygen permeability in
the final polymers are difficult to achieve.
[0005] US 2010/0048847 discloses silicone hydrogels made from a blend of a monomethacryloxyalkylpolydimethylsiloxane
methacrylate with about 52% NVP, HEMA and TRIS, and using a blend of ethanol and ethyl
acetate as a diluent. The polymers disclosed are (to varying degrees) hazy, but it
was disclosed in this application that the haziness could be reduced by the addition
of at least about 1.5 % methacrylic acid (MAA).
[0006] Addition of anionic monomers such as MAA can, however, cause hydrolytic instability
in silicone hydrogels, as was disclosed in "
The role of ionic hydrophilic monomers in silicone hydrogels for contact lens application",
Lai, Y., Valint, P., and Friends, G.; 213th ACS National Meeting, San Francisco, April
13-17, 1997. For this reason, it remains desirable to form clear, hydrolytically stable, wettable
(without surface treatment) silicone hydrogels with low moduli from a combination
of a monomethacryloxyalkyl polydimethylsiloxane methacrylate such as mPDMS, and NVP.
[0007] US 2002/016383 A1 discloses hydrogel soft contact lens which has contact angle at a lens surface in
a range of 10-50° by the captive bubble method in water and 30-90° by the sessile
drop method in air, oxygen permeability of not less than 30 and water content of not
less than 5%, and also a hydrogel soft contact lens consisting of a polymer comprising
a hydrophilic siloxanyl monomer.
[0008] US 2011/230589 A1 discloses silicone hydrogels obtained by polymerizing a polymerization mix containing
a plurality of monomers containing about 30 to about 98 weight % of at least one silicone
monomer; and about 1 to about 50 weight % of at least one non-silicone (meth)acrylamide
monomer.
[0009] US 2010/249356 A1 discloses silicone hydrogels formed from at least one silicone component comprising
at least one trimethylsiloxy silyl group and at least one ionic component, and the
thermal stability thereof.
[0010] WO 2011/041523 A2 discloses silicone hydrogel contact lenses which, when hydrated, have a plurality
of depressions on one or more of the lens surfaces. The depressions have a depth less
than 1 micrometer, or less than 100 nanometers. The silicone hydrogel contact lenses
have not been subject to treatment with plasma.
Summary of the Invention
[0011] The invention provides a silicone hydrogel formed from a reaction mixture comprising,
consisting of, or consisting essentially of
30 to 75 wt% of at least one slow-reacting hydrophilic monomer having a slow-reacting
hydrophilic monomer kinetic half-life;
at least one silicone-containing component having a silicone-containing component
kinetic half-life, which may be optionally substituted with at least one hydroxyl
containing group ;
at least one visible light photoinitiator;
at least one hydroxyl-containing component selected from at least one hydroxyl-substituted,
silicone-containing component, the at least one silicone-containing component having
a silicone-containing component half-life substituted with at least one hydroxyl containing
group, at least one hydroxyalkyl monomer, and mixtures thereof; and at least one UV
absorbing compound, wherein when the at least one silicone-containing component having
a silicone-containing component kinetic half-life is substituted with at least one
hydroxyl containing group, this may be one and the same component as the at least
one hydroxyl-containing component, and wherein polymerization of the reaction mixture
is initiated using visible light; and
wherein the ratio of said slow-reacting hydrophilic component half-life to said silicone-containing
component half life is at least 2.
[0012] The present disclosure also provides a silicone hydrogel formed from a reaction mixture
comprising, consisting of, or consisting essentially of 30 to 75 wt% of at least one
slow-reacting hydrophilic monomer; at least one silicone-containing component; and
at least one photoinitiator;
wherein at least one of said silicone-containing component, optional additional hydrophilic
components or both comprises at least one hydroxyl group and wherein said slow-reacting
hydrophilic component and said silicone-containing component are selected to have
a conversion ratio at 90% conversion of at least 20.
[0013] The present invention also provides a process for forming the silicone hydrogel of
the invention by photocuring the reaction mixture, wherein said photocuring is completed
in 30 minutes or less.
The invention is defined by the claims.
Description of the Figures
[0014]
Figure 1 is a schematic of a lens assembly.
Figure 2 is a schematic of the dual compartment cure box used for the kinetic evaluations.
Figure 3 is a schematic of compartment 2 of the cure box show in Figure 2.
Figure 4 is a graph of the conversion mole ratio vs. advancing contact angle of the
contact lenses made in Examples 1, 3-13, 17, 19-23 and Comparative Examples 1, 3,
4 and 6-7.
Figure 5 is a graph of the half life ratio vs. advancing contact angle for the contact
lenses made in Examples 1, 3-13, 17, 19-23 and Comparative Examples 1, 3, 4 and 6-7.
Figure 6 is a graph of the half life ratio vs. advancing contact angle for the contact
lenses, with the axis for the half life ratios expanded to show the area up to 3.
Figure 7 is a graph of the half life ratio vs. Dk for the contact lenses with the
axis for the half life ratios expanded to show the area up to 4.
Detailed Description of the Invention
[0015] The present invention relates to silicone hydrogels formed from reaction mixtures
comprising at least one hydrophilic component which has a kinetic half life which
is at least twice as long as the kinetic half life of the slowest silicone containing
composition. At least one component of the reaction mixture comprises at least one
hydroxyl group. The resulting silicone hydrogels are surprisingly easy to process
and display an exceptional balance of properties including haze, water content and
oxygen permeability.
[0016] As used herein, "diluent" refers to a non-reactive solvent for the reactive components.
Diluents do not react to form part of the biomedical devices.
[0017] As used herein, a "biomedical device" is any article that is designed to be used
while either in or on mammalian tissues or fluid, and in or on human tissue or fluids.
Examples of these devices include but are not limited to catheters, implants, stents,
and ophthalmic devices such as intraocular lenses, punctal plugs and contact lenses.
For example, the biomedical devices are ophthalmic devices, particularly contact lenses,
most particularly contact lenses made from silicone hydrogels.
[0018] As used herein, the terms "ophthalmic device" refers to products that reside in or
on the eye. As used herein, the terms "lens" and "ophthalmic device" refer to devices
that reside in or on the eye. These devices can provide optical correction, wound
care, drug delivery, diagnostic functionality, cosmetic enhancement or effect, glare
reduction, UV blocking or a combination of these properties. Examples of ophthalmic
devices include lenses, and punctal plugs. The term lens (or contact lens) includes
to soft contact lenses, hard contact lenses, intraocular lenses, overlay lenses, ocular
inserts, and optical inserts.
[0019] As used herein "reaction mixture" refers to reactive and non-reactive components
(including the diluent) that are mixed together and reacted to form the silicone hydrogels
of the present invention. The reactive components are everything in the reaction mixture
except the diluent and any additional processing aids which do not become part of
the structure of the polymer.
As used herein "(meth)" refers to an optional methyl substitution. Thus, a term such
as "(meth)acrylate" denotes both methacrylic and acrylic radicals.
[0020] All percentages in this specification are weight percentages unless otherwise noted.
[0021] As used herein, the phrase "without a surface treatment" or "not surface treated"
means that the exterior surfaces of the devices of the present invention are not separately
treated to improve the wettability of the device. Treatments which may be foregone
because of the present invention include, plasma treatments, grafting, and coating.
Coatings which provide properties other than improved wettability, such as, antimicrobial
coatings and the application of color or other cosmetic enhancement, are not considered
surface treatment.
[0022] As used herein "silicone macromers" and silicone "prepolymers" mean mono- and multi-functional
silicone containing compounds having molecular weights of greater than 2000.
[0023] As used herein "hydroxyl-containing component" is any component containing at least
one hydroxyl group.
[0024] As used herein "kinetic half life" means the time elapsed at the given reaction conditions
for 50 % of the reactive component to be consumed. It should be appreciated that the
kinetic half life for a given component will be influenced by the other reaction mixture
components, as well as the cure conditions selected, as is described in detail herein.
Kinetic half life is calculated as described in the examples.
[0025] The kinetic half life ratios calculated herein must be calculated using the kinetic
half lives measured from that particular reaction mixture and cure conditions.
[0026] As used herein "monovalent reactive groups" are groups that can undergo free radical
and/or cationic polymerization. Non-limiting examples of free radical reactive groups
include (meth)acrylates, styryls, vinyls, vinyl ethers, C
1-6alkyl(meth)acrylates, (meth)acrylamides, C
1-6alkyl(meth)acrylamides, N-vinyllactams, N-vinylamides, C
2-12alkenyls, C
2-12alkenylphenyls, C
2-12alkenylnaphthyls, C
2-6alkenylphenylC
1-6alkyls, O-vinylcarbamates and O-vinylcarbonates. Examples of cationic reactive groups
include vinyl ethers or epoxide groups and mixtures thereof. Examples of the free
radical reactive groups include (meth)acrylate, acryloxy, (meth)acrylamide, and mixtures
thereof.
[0027] It has been surprisingly found that by selecting the components of the reaction mixture,
silicone hydrogels having a desirable balance of properties may be formed. The reaction
mixtures of the present invention comprise 30 to 75 wt%, between 37 and 75wt%; between
39 and 70wt%; and between 39 and 60 wt% of at least one slow-reacting hydrophilic
monomer;
at least one reactive silicone-containing component;
at least one visible light photoinitiator; and may comprise at least one crosslinker
which has a kinetic half life which is not slower than the kinetic half life of the
fastest reacting silicone containing component. The slowest reacting silicone-containing
component has a kinetic half life which is at least half the kinetic half life of
the slow-reacting hydrophilic monomer. At least one of said components comprises at
least one hydroxyl group. The at least one component may be a hydroxyalkyl (meth)acrylate
or hydroxyalkyl (meth)acrylamide.
[0028] In the present invention the components are selected to react at specific points
in the reaction. For example, "fast reacting" components are selected to polymerize
primarily at the beginning of the overall copolymerization reaction, while the slow
reacting hydrophilic monomer is selected to polymerize primarily at the end of the
overall copolymerization reaction. Fast reacting components include the silicone-containing
components, the hydroxyalkyl monomers and some crosslinkers. In one embodiment slow
reacting components have kinetic half lives which are at least about two times greater
than the fastest silicone containing monomer. Kinetic half lives may be measured as
described herein. It should be appreciated that the kinetic half lives are relative
to specific formulations.
[0029] Examples of slow reacting groups include (meth)acrylamides, vinyls, allyls and combinations
thereof and a least one hydrophilic group. Non-limiting examples of the slow reacting
group include N-vinyl amides, O-vinyl carbamates, O-vinyl carbonates, N-vinyl carbamates,
O-vinyl ethers, O-2-propenyl, wherein the vinyl or allyl groups may be further substituted
with a methyl group. The slow reacting group may be selected from N-vinyl amides,
O-vinyl carbonates, and O-vinyl carbamates.
[0030] Examples of fast reacting groups include (meth)acrylates, styryls, (meth)acryamides
and mixtures thereof. Generally (meth)acrylates are faster than (meth)acrylamides,
and acrylamides are faster than (meth)acrylamides.
[0031] Throughout the specification, wherever chemical structures are given, it should be
appreciated that alternatives disclosed for the substituents on the structure may
be combined in any combination. Thus if a structure contained substituents R
1 and R
2, each of which contained three lists of potential groups, 9 combinations are disclosed.
The same applies for combinations of properties.
[0032] The first component of the reactive mixture is at least one slow-reacting hydrophilic
monomer. The slow-reacting hydrophilic monomer comprises a slow reacting group and
at least one hydrophilic group including hydroxyls, amines, ethers, amides, ammonium
groups, carboxylic acid, carbamates, combinations thereof and the like. Suitable hydrophilic
groups include hydroxyls, ethers, amides, carboxylic acid combinations thereof and
the like.
[0033] If a (meth)acrylamide is selected as the slow-reacting hydrophilic monomer, a silicone-containing
monomer having a very short kinetic half life, such as an acrylate must be used. Methacrylamides
are generally slower reacting that acrylamides, and bulky (meth)acrylamides are slower
than smaller (meth)acrylamides. Examples of a suitable (meth)acrylamide include bis-(2-hydroxyethyl)
methacrylamide, 2,3-dihydroxypropyl methacrylamide,
N-[3-(Dimethylamino)propyl]methacrylamide, N-[tris(hydroxymethyl)methyl]acrylamide
and methacrylamides substituted with one or two polyethylene glycol chains having
2-10, 2-5 repeating units. Where a methacrylamide is used as the slow-reacting hydrophilic
monomer, very fast silicone containing monomer, such as silicone acrylates should
be used to provide the desired difference in kinetic half lives. For example,
N-[3-(Dimethylamino)propyl]methacrylamide may be used as the slow-reacting hydrophilic
monomer with silicone acrylates.
[0034] The slow-reacting hydrophilic monomer may be selected from N-vinylamide monomer of
Formula I, a vinyl pyrrolidone of Formula II-IV, n-vinyl piperidone of Formula V :
wherein R is H or methyl, suitably R is H;
R1, R2, R3, R6, R7, R10, and R11 are independently selected from H, CH3, CH2CH3, CH2CH2CH3, C(CH3)2;
R4 and R8 are independently selected from CH2, CHCH3 and -C(CH3);
R5 is selected from H, methyl, ethyl, ; and
R9 is selected from CH=CH2, CCH3=CH2, and CH=CHCH3.
[0035] The total number of carbon atoms in R
1 and R
2 may be 4 or less, and R
1 and R
2 may be methyl.
[0036] The slow-reacting hydrophilic monomer may be selected from the N-vinyl amide monomer
of Formula I or a vinyl pyrrolidone of Formula II or IV. Suitably R
6 is methyl, R
7 is hydrogen, R
9 is CH=CH
2; and R
10 and R
11 are H.
[0037] The slow-reacting hydrophilic monomer may be selected from ethylene glycol vinyl
ether (EGVE), di(ethylene glycol) vinyl ether (DEGVE), N-vinyl lactams, including
N-vinyl pyrrolidone (NVP), 1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,
5-methyl-3-methylene-2-pyrrolidone; 1-ethyl-5-methylene-2-pyrrolidone, N-methyl-3-methylene-2-pyrrolidone,
5-ethyl-3-methylene-2-pyrrolidone, 1-n-propyl-3-methylene-2-pyrrolidone, 1-n-propyl-5-methylene-2-pyrrolidone,
1-isopropyl-3-methylene-2-pyrrolidone, 1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl
acetamide (VMA), N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,
N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinyl caprolactam, N-2-hydroxyethyl
vinyl carbamate, N-carboxyvinyl-β-alanine (VINAL), N-carboxyvinyl-α-alanine and mixtures
thereof.
[0038] Thus, the slow-reacting hydrophilic monomer may be selected from NVP, VMA and 1-methyl-5-methylene-2-pyrrolidone.
Preferably, the slow-reacting hydrophilic monomer comprises NVP.
[0039] The slow reacting hydrophilic monomer is present in amounts to provide wettability
to the resulting polymer. Wettability may be measured via dynamic contact angle, and
desirable advancing contact angles are less than 80°, less than 70° or less than 60°.
[0040] The at least one silicone-containing monomer is monofunctional and comprises (a)
a fast reacting group thereof and (b) a polydialkyl siloxane chain. The silicon-containing
monomer may comprise a fast reacting group selected from (meth)acrylates, styryls,
amides and mixtures thereof. The at least one silicone-containing monomer may also
contain at least one fluorine. The silicone-containing component may be selected from
mono (meth)acryloxyalkyl polydialkylsiloxane monomer of Formula VII or the styryl
polydialkylsiloxane monomer of Formula VIII:
wherein R12 is H or methyl;
X is O or NR16;
Each R14 is independently a phenyl or C1 to C4 alkyl which may be substituted with fluorine, hydroxyl or ether. Each R14 may be independently selected from ethyl and methyl groups. All R14 may be methyl;
R15 is an unsubstituted C1 to C4 alkyl;
R13 is a divalent alkyl group, which may further be functionalized with a group selected
from the group consisting of ether groups, hydroxyl groups, carbamate groups and combinations
thereof, C1-C6 alkylene groups which may be substituted with ether, hydroxyl and combinations thereof,
or C1 or C3-C6 alkylene groups which may be substituted with ether, hydroxyl and combinations thereof;
a is 2 to 50, or 5 to 15.
R16 is selected from H, C1-4alkyls, which may be further substituted with one or more hydroxyl groups, H or methyl.
[0041] R
12 and each R
14 may be methyl.
[0042] At least one R
14 may be 3,3,3-trifluoropropyl.
[0043] Examples of suitable silicone-containing monomers include monomethacryloxyalkylpolydimethylsiloxane
methacrylates selected from the group consisting of monomethacryloxypropyl terminated
mono-n-butyl terminated polydimethylsiloxane, monomethacryloxypropyl terminated mono-n-methyl
terminated polydimethylsiloxane, monomethacryloxypropyl terminated mono-n-butyl terminated
polydiethylsiloxane, monomethacryloxypropyl terminated mono-n-methyl terminated polydiethylsiloxane,
N-(2,3-dihydroxypropane)-N'-(propyl tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide,
α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane, and mixtures
thereof.
[0044] The silicone-containing component may be selected from the group consisting of monomethacryloxypropyl
terminated mono-n-butyl terminated polydimethylsiloxane, monomethacryloxypropyl terminated
mono-n-methyl terminated polydimethylsiloxane, N-(2,3-dihydroxypropane)-N'-(propyl
tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide, α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane,
and mixtures thereof.
[0046] Additional silicone containing components having one or more polymerizable groups
may also be included. Any additional disclosed silicone components having the herein
disclosed reactive groups may be included. Examples include silicone containing monomers
displaying branched siloxane chains such as SiMAA and TRIS.
[0047] The at least one silicone-containing component is present in the reactive mixture
in an amount sufficient to provide the desired oxygen permeability. It is a benefit
of the present invention that oxygen permeabilities greater than 70 barrers, greater
than 80 barrer, greater than 90 barrer, or greater than 100 barrer may be achieved.
Suitable amounts will depend on the length of the siloxane chain included in the silicone-containing
monomers, with silicone-containing monomers having longer chains requiring less monomer.
Amounts include from 20 to 60 weight%, or from 30 to 55 weight %.
[0048] The slow-reacting hydrophilic monomer and the at least one silicone-containing monomer
are selected such that the ratio of the kinetic half life of the slow-reacting hydrophilic
monomer to the kinetic half life of the slowest silicone-containing component is at
least 2, at least 3 or at least 5.
[0049] As part of the present invention it is desirable to polymerize long chains of the
slow-reacting hydrophilic monomer. A substantial amount of slow-reacting hydrophilic
monomer must polymerize late in the process in order to achieve the desired balance
of properties. This may be characterized by the ratio (unit-less) of the concentrations
(expressed in µmol/g) of the slow-reacting hydrophilic monomer to the slowest reacting
silicone-containing monomer at 90% conversion of the slowest reacting silicone-containing
monomer ("conversion ratio"). The conversion ratio is greater than 10, at least 20,
or at least 30.
[0050] The reaction mixture may be substantially free of TRIS, and also may be substantially
free of silicone containing macromers or prepolymers.
[0051] At least one of the components of the reaction mixture must contain at least one
hydroxyl group. The hydroxyl may be contained on the silicone-containing monomer,
an additional monomer or a combination thereof. It is preferred that the kinetic half
life of the hydroxyl-containing component be close to the kinetic half life of the
silicone containing monomers. Preferred kinetic half life ratios of the hydroxyl-
containing component to the silicone containing monomer include 0.75 to 1.5 and 0.8
to 1.2. The hydroxyl containing components may have the same reactive functionality
as the silicone-containing monomers.
[0052] Also, (meth)acrylate monomers with hydroxyl group(s), such as but not limited to
SiMAA, and HEMA, have been found to be better at compatibilizing NVP, VMA and other
amide containing monomers, than (meth)acrylamide monomers with hydroxyl group(s).
Thus where clear lenses with dynamic advancing contact angles of less than 80° are
desired, the hydroxyl-containing monomers may comprise (meth)acrylate monomers.
[0053] The hydroxyl-containing components may be present in mole percents which form a molar
ratio of hydroxyl groups to the slow-reacting hydrophilic monomer of at least 0.15
or between 0.15 and 0.4. This is calculated by dividing the number of moles of hydroxyl
groups in the hydroxyl group-containing monomers (including any hydroxyl groups on
the slow-reacting hydrophilic monomer and the silicone-containing monomer) by the
number of moles of the slow-reacting hydrophilic monomer per a given mass of the monomer
mix. In this embodiment, for a reaction mixture comprising HO-mPDMS, HEMA, EGVE and
NVP, the hydroxyl groups on each of HO-mPDMS, HEMA and EGVE would be counted. Any
hydroxyl groups present in the diluent (if used) are not included in the calculation.
The at least one silicone-containing monomer may comprise at least one hydroxyl group.
[0054] Alternatively, the molar ratio of all hydroxyl groups on reactive components in the
reaction mixture to silicon (HO:Si) is between 0.16 and 0.4. The molar ratio is calculated
by dividing molar concentration of hydroxyl groups in the components of the reactive
mixture (other than any hydroxyls which are part of the slow-reacting hydrophilic
monomer or diluents) by the molar concentration of silicon. In this embodiment both
the hydroxyalkyl monomers and any hydroxyl-containing silicone components are included
in the calculation. Thus, in calculating the HO:Si ratio of the reaction mixture comprising
HO-mPDMS, HEMA, NVP and EGVE, only the hydroxyl groups on each of HO-mPDMS, HEMA would
be counted in calculating the HO:Si.
[0055] Alternatively, the molar ratio of hydroxyl groups in non-silicone containing components
(other than any hydroxyls which are part of the slow-reacting hydrophilic monomer
or diluents) to silicon is between 0.13 and 0.35. Thus, in calculating the HO
non-Si:Si ratio of the reaction mixture comprising HO-mPDMS, HEMA, EGVE, and NVP only the
hydroxyl groups on, HEMA would be counted in calculating the HO
non-Si:Si ratio.
[0056] It will be appreciated that the minimum amount of hydroxyl component will vary depending
upon a number of factors, including, the number of hydroxyl groups on the hydroxyalkyl
monomer, the amount, molecular weight and presence or absence of hydrophilic functionality
on the silicone containing components. For example, where HEMA is used as the hydroxyalkyl
monomer and mPDMS is used in amounts about 38wt% as the sole silicone containing monomer,
at least 8wt% HEMA (0.16 HO:Si) is included to provide the desired haze values. However,
when lesser amounts of mPDMS are used (20%), as little as 2 or 3% HEMA provides silicone
hydrogel contact lenses having haze values below 50%. Similarly, when the formulation
includes substantial amounts of a hydroxyl-containing silicone component (such as
greater than 20 wt% HO-mPDMS as in Examples 68-73), amounts of HEMA as low as 7 wt%
(0.13 HO:Si, or 0.24 HO
total:Si) may provide the desired level of haze.
[0057] Suitable hydroxyl-containing monomers include hydroxyalkyl (meth)acrylate or (meth)acrylamide
monomer of Formula IX or a styryl compound of Formula X:
wherein R1 is H or methyl,
X is O or NR16, R16 is a H, C1 to C4 alkyl, which may be further substituted with at least one OH, methyl or 2-hydroxyethyl
and
R17 is selected from C2-C4 mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having 1-10 repeating
units; or 2-hydroxyethyl, 2,3-dihydroxypropyl, 2-hydroxypropyl.
[0058] R
1 may be H or methyl, X oxygen and R selected from C
2-C
4 mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having 1-10 repeating
units. Suitably, R
1 may be methyl, X oxygen and R may be selected from C
2-C
4 mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having 2-20 repeating
units. R
1 may be methyl, X oxygen and R selected from C
2-C
4 mono or dihydroxy substituted alkyl. Suitably, at least one hydroxyl group is on
the terminal end of the R alkyl group.
[0059] Examples of suitable hydroxyalkyl-containing monomers include 2-hydroxyethyl methacrylate,
2-hydroxyethyl acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
1-hydroxypropyl-2-(meth)acrylate, 2-hydroxy-2-methyl-propyl (meth)acrylate, 3-hydroxy-2,2-dimethyl-propyl
(meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, 2-hydroxyethyl
(meth)acrylamide, polyethyleneglycol monomethacrylate, bis-(2-hydroxyethyl) (meth)acrylamide,
2,3-dihydroxypropyl (meth)acrylamide, and mixtures thereof.
[0060] The hydroxyl-containing monomer may be selected from the group consisting of 2-hydroxyethyl
methacrylate, glycerol methacrylate, 2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,
3-hydroxy-2,2-dimethyl-propyl methacrylate, and mixtures thereof.
[0061] The hydroxyl-containing monomer may comprise 2-hydroxyethyl methacrylate or 3-hydroxy-2,2-dimethyl-propyl
methacrylate. The hydroxyl-containing monomer may comprise glycerol methacrylate.
[0062] The reactive mixture may further comprise additional hydrophilic monomers. Any hydrophilic
momomers used to prepare hydrogels may be used. For example monomers containing acrylic
groups (CH
2=CROX, where R is hydrogen or C
1-6alkyl an X is O or N) or vinyl groups (-C=CH
2) may be used. Examples of additional hydrophilic monomers are N,N-dimethylacrylamide,
polyethyleneglycol monomethacrylate, methacrylic acid, acrylic acid, combinations
thereof and the like.
[0063] If the additional hydrophilic monomers have kinetic half lives which are intermediate
to the slow reacting hydrophilic monomers and silicone containing components as defined
herein, their concentrations in the formulations of the present invention may be limited
to concentrations which do not provide the lens with an advancing contact angle higher
than 80°. As used herein, "intermediate" half life is one that is between 20% and
70% faster than the slowest reacting silicone component. For example, if the additional
hydrophilic monomer is N,N-dimethylacrylamide, the amount of the additional hydrophilic
monomer is below 3 wt% in cases where uncoated lenses are desired. Where the lens
is to be surface modified, higher amounts of additional monomers may be included.
[0064] The reaction mixtures of the present invention may further comprise at least one
crosslinker which has a kinetic half life less than or equal to the kinetic half life
of at least one of the silicone-containing monomers included in the reaction mixture.
A crosslinker is a monomer with two or more polymerizable double bonds. It has been
found that when the kinetic half life of the crosslinker is longer than at least one
of the silicone-containing monomers, the resulting hydrogel displays decreased modulus
and increased water content. Surprisingly, the reaction rate of the crosslinker can
be substantially reduced by the inclusion of a UV absorbing compound. This increases
the kinetic half life, and in some systems changed the reaction order, such that the
crosslinker reacted more slowly that the silicone-containing monomers. In this circumstance
it may be desirable to use a crosslinker with a faster reaction rate in the presence
of the selected UV absorber.
[0065] Suitable crosslinkers include ethylene glycol dimethacrylate ("EGDMA"), trimethylolpropane
trimethacrylate ("TMPTMA"), glycerol trimethacrylate, polyethylene glycol dimethacrylate
(wherein the polyethylene glycol preferably has a molecular weight up to, e.g., about
5000), and other polyacrylate and polymethacrylate esters, such as the end-capped
polyoxyethylene polyols described above containing two or more terminal methacrylate
moieties. The crosslinker may be used in the usual amounts, e.g., from 0.000415 to
0.0156 mole per 100 grams of reactive components in the reaction mixture. Alternatively,
if the hydrophilic monomers and/or the silicone containing monomers act as the crosslinking
agent, the addition of an additional crosslinking agent to the reaction mixture is
optional. Examples of hydrophilic monomers which can act as the crosslinking agent
and when present do not require the addition of an additional crosslinking agent to
the reaction mixture include polyoxyethylene polyols described above containing two
or more terminal methacrylate moieties.
[0066] An example of a silicone containing monomer which can act as a crosslinking agent
and, when present, does not require the addition of a crosslinking monomer to the
reaction mixture includes α, ω-bismethacryloypropyl polydimethylsiloxane.
[0067] The reaction mixtures can also contain multiple crosslinkers depending on the reaction
rate of the hydrophilic component. With very slow reacting hydrophilic components
(e.g. VMA, EGVE, DEGVE) crosslinkers having slow reacting functional groups (e.g.
di-vinyl, tri-vinyl, di-allyl, tri-allyl) or a combination of slow reacting functional
groups and fast reacting functional groups (e.g. HEMAVc, allylmethacrylate) can be
combined with crosslinkers having fast reacting functional groups to improve the retention
of the polymers of the slow-reacting monomers in the final hydrogel.
[0068] The reaction mixture may comprise at least two crosslinkers, at least one fast reacting
crosslinker having at least two fast reacting groups which will react with the silicone
components and hydroxyl-containing components and at least one slow reacting crosslinker
having at least two slow reacting groups which react with the slow reacting hydrophilic
monomer. This mixture of fast and slow reacting crosslinkers provides the final polymer
with improved resilience and recovery, particularly on the surface of the lens. Examples
of suitable first crosslinkers include those having only (meth)acrylate functionality,
such as EGDMA, TEGDMA and combinations thereof. Examples of suitable second crosslinkers
include those having only vinyl functionality, such as triallyl cyanurate (TAC). When
mixtures are used, suitable amounts of all crosslinker in the reactive mixture include
between 0.10% and 1.0%, or between 0.10% and 2%, excluding diluent respectively. In
another embodiment the total amount of all crosslinker in the reactive mixtures is
between 0.7 to 6.0 mmol/100 g of polymerizable components; between 0.7 to 4.0 mmoles
per 100 g of reactive components. The fast and slow reacting crosslinkers are present
in amounts of 0.3 to 2.0 mmol/100 g of polymerizable components each; and between
0.4 to 2.0 mmoles per 100 g of reactive components.
[0069] The reaction mixture also comprises at least one UV absorbing compound. Surprisingly,
UV absorbing compounds can have a substantially different impact on the reaction kinetics
of the reactive components in the reaction mixtures of the present invention. For
example, it has been found that benzotriazoles substantially slow the rate of reaction
for NVP and TEGDMA is some systems much more than the reaction rates of the silicone-containing
components. In the case of NVP, this is beneficial, as it provides additional processing
flexibility and an exceptional balance of properties, including water contents in
excess of 60%, haze values less than 50%, or less than 10%, advancing contact angles
less than 60° and Dk's greater than 80. When the silicone hydrogel will be used as
an ophthalmic device it may be desirable to incorporate a reactive UV absorbing compound
in the reaction mixture so that the resulting silicone hydrogel will be UV absorbing.
However, the non-reactive UV absorbing compounds may be used solely to achieve the
desired reaction kinetics. Alternatively solution filters may be used. It is believed
that the UV absorbers in the reactive mixtures block incident light below 370 nm which
alters the spectrum of light being imposed on the visible photoinitiator. This tends
to reduce the rate of initiation as well as lower the concentration of initiator radicals
present, which in turn is believed to have a significant impact on the rate of polymerization
of the monomers. Typically, the monomers which are likely to be most significantly
impacted are the slowest and fastest. In several of the examples included herein,
NVP (slowest) and TEGDMA (the fastest) are the most sensitive to the presence of the
UV absorber.
[0070] Suitable UV absorbers may be derived from 2-(2'-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones,
2-hydroxyphenyltriazines, oxanilides, cyanoacrylates, salicylates and 4-hydroxybenzoates;
which may be further reacted to incorporate reactive polymerizable groups, such as
(meth)acrylates. Specific examples of UV absorbers which include polymerizable groups
include 2-(2'-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole (Norbloc), 5-vinyl
and 5-isopropenyl derivatives of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole and 4-acrylates
or 4-methacrylates of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole or 2-(2,4-dihydroxyphenyl)-1,3-2H-dibenzotriazole
, mixtures thereof and the like. A UV absorber is included, it may be included in
amounts between 0.5 and 4 wt%, and suitably between 1 wt% and 2 wt%.
[0071] A polymerization initiator is included in the reaction mixture. The reaction mixtures
of the present invention comprise at least one visible light photoinitiator. The use
of photoinitiation provides desirable cure times (time to reach essentially complete
cure) of less than 30 minutes, less than about 20 minutes or less than 15 minutes.
The photopolymerization systems also greater flexibility in tailoring the properties
of the resulting silicone hydrogel through the use of UV absorbers in the reaction
mixtures. Suitable photoinitiator systems include aromatic alpha-hydroxy ketones,
alkoxyoxybenzoins, acetophenones, acylphosphine oxides, bisacylphosphine oxides, and
a tertiary amine plus a diketone, mixtures thereof and the like. Illustrative examples
of photoinitiators are 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one,
bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide (DMBAPO), bis(2,4,6-trimethylbenzoyl)-phenyl
phosphineoxide (Irgacure 819), 2,4,6-trimethylbenzyldiphenyl phosphine oxide and 2,4,6-trimethylbenzoyl
diphenylphosphine oxide, benzoin methyl ester and a combination of camphorquinone
and ethyl 4-(N,N-dimethylamino)benzoate. Commercially available visible light initiator
systems include Irgacure 819, Irgacure 1700, Irgacure 1800, Irgacure 819, Irgacure
1850 (all from Ciba Specialty Chemicals) and Lucirin TPO initiator (available from
BASF). Commercially available UV photoinitiators include Darocur 1173 and Darocur
2959 (Ciba Specialty Chemicals). These and other photoinitiators which may be used
are disclosed in
Volume III, Photoinitiators for Free Radical Cationic & Anionic Photopolymerization,
2nd Edition by J.V. Crivello & K. Dietliker; edited by G. Bradley; John Wiley and
Sons; New York; 1998. The initiator is used in the reaction mixture in effective amounts to initiate photopolymerization
of the reaction mixture, e.g., from 0.1 to 2 parts by weight per 100 parts of reactive
monomer. As is shown in the Examples, the concentration of photoinitiator used can
affect the reaction kinetics of the reactive components. While increasing the amount
of initiator generally decreases the kinetic half live of all the components, the
half lives are not affected equally. Thus, the ratio of the slow-reacting hydrophilic
monomer and silicone containing monomer can be adjusted by varying the initiator concentration.
The effect can be increased by adding or increasing the concentration of inhibitors
included in the reactive mixture. Some inhibitors may be included with the monomers
which are selected. Inhibitors may also be intentionally added to the reaction mixtures
of the present application. The amount of inhibitor which may be included is from
about 100 to about 2,500 µgm/gm of reaction mixture.
[0072] Inhibitors may optionally be included. Surprisingly the inclusion of even substantial
amounts of BHT, a free radical inhibitor did not substantially change the half life
ratios measured. However, inclusion of increasing amounts of inhibitor did change
the properties of the resulting lenses, decreasing modulus. Thus, it may be desirable
to include at least one inhibitor in the reactive mixture. Free radical inhibitors
are compounds that react rapidly with propagating radicals to produce stable radical
species that terminate the chain. Classes of inhibitors include quinones, substituted
phenols, secondary aromatic amines, lactones and nitro compounds. Specific examples
of inhibitors include BHT, MEHQ, hydroxyamines, benzofuranone derivatives, molecular
oxygen, vitamin E, nitric oxide/nitrogen dioxide mixtures (which form nitroxides in
situ) mixtures and combinations thereof and the like.
[0073] Examples of classes of chain transfer agents include alkyl thiols, dithiocarboxylic
acid esters, combinations thereof and the like. Examples of controlled free radical
initiators include nitroxide mediated polymerization (NMP) (including those disclosed
in
The Chemistry of Radical Polymerization, 2nd ed. Moad and Solomon, pgs 472-479), atom-transfer radical polymerization (ATRP), including low molecular weight activated
organic halides (including those disclosed in
The Chemistry of Radical Polymerization, 2nd ed. Moad and Solomon, pgs 488-89 and
492-497), and reversible addition fragmentation (chain) transfer (RAFT) polymerization, including
thiocarbonylthio agents (such as those disclosed at including those disclosed in
The Chemistry of Radical Polymerization, 2nd ed. Moad and Solomon, pgs 508-514). In the case where controlled free radical initiators are used, they are used as
part or all of the initiator system.
[0074] It is disclosed that polymerization of the reaction mixture can be initiated using
the appropriate choice visible or ultraviolet light. Alternatively, initiation can
be conducted without a photoinitiator using, for example, e-beam. The initiators may
be selected from bisacylphosphine oxides, such as bis(2,4,6-trimethylbenzoyl)-phenyl
phosphine oxide (Irgacure 819®) or a combination of 1-hydroxycyclohexyl phenyl ketone
and bis(2,6-dimethoxybenzoyl)-2,4-4-trimethylpentyl phosphine oxide (DMBAPO). In the
invention, the method of polymerization initiation is visible light. Bis(2,4,6-trimethylbenzoyl)-phenyl
phosphine oxide (Irgacure 819®) is a suitable photoinitiator.
[0075] The reaction mixture may also comprise at least one diluent or may be "neat". If
a diluent is used, the selected diluents should solubilize the components in the reactive
mixture. It will be appreciated that the properties of the selected hydrophilic and
hydrophobic components may affect the properties of the diluents which will provide
the desired compatibilization. For example, if the reaction mixture contains only
moderately polar components, diluents having moderate δp may be used. If however,
the reaction mixture contains strongly polar components, the diluent may need to have
a high δp. However, as the diluent becomes more hydrophobic, processing steps necessary
to replace the diluent with water will require the use of solvents other than water.
This may undesirably increase the complexity and cost of the manufacturing process.
Thus, it is important to select a diluent which provides the desired compatibility
to the components with the necessary level of processing convenience.
[0076] The type and amount of diluent used also effects the properties of the resultant
polymer and article. The haze, wettability and wettability of the final article may
be improved by selecting relatively hydrophobic diluents and/or decreasing the concentration
of diluent used.
[0077] Diluents useful in preparing the devices of this invention include polar diluents,
such as ethers, esters, amides, alcohols, carboxylic acids and combinations thereof.
Amides, carboxylic acids and alcohols are preferred diluents, and carboxylic acids,
secondary and tertiary alcohols are more preferred diluents.
[0078] Examples of alcohols useful as diluents for this invention include those having the
formula

wherein R, R' and R" are independently selected from H, a linear, branched or cyclic
monovalent alkyl having 1 to 10 carbons which may optionally be substituted with one
or more groups including halogens, ethers, esters, aryls, amines, amides, alkenes,
alkynes, carboxylic acids, alcohols, aldehydes, ketones or the like, or any two or
all three of R, R' and R" can together bond to form one or more cyclic structures,
such as alkyl having 1 to 10 carbons which may also be substituted as just described,
with the proviso that no more than one of R, R' or R" is H.
[0079] It is preferred that R, R' and R" are independently selected from H or unsubstituted
linear, branched or cyclic alkyl groups having 1 to 7 carbons. It is more preferred
that R, R', and R" are independently selected form unsubstituted linear, branched
or cyclic alkyl groups having 1 to 7 carbons. The preferred diluent may have 4 or
more, more preferably 5 or more total carbons, because the higher molecular weight
diluents have lower volatility, and lower flammability. When one of the R, R' and
R" is H, the structure forms a secondary alcohol. When none of the R, R' and R" are
H, the structure forms a tertiary alcohol. Tertiary alcohols are more preferred than
secondary alcohols. The diluents are preferably inert and easily displaceable by water
when the total number of carbons is five or less.
[0080] Examples of useful secondary alcohols include 2-butanol, 2-propanol, menthol, cyclohexanol,
cyclopentanol and exonorborneol, 2-pentanol, 3-pentanol, 2-hexanol, 3-hexanol, 3-methyl-2-butanol,
2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 3-octanol, and norborneol.
[0081] Examples of useful tertiary alcohols include tert-butanol, tert-amyl, alcohol, 2-methyl-2-pentanol,
2,3-dimethyl-2-butanol, 3-methyl-3-pentanol, 1-methylcyclohexanol, 2-methyl-2-hexanol,
3,7-dimethyl-3-octanol, 1-chloro-2-methyl-2-propanol, 2-methyl-2-heptanol, 2-methyl-2-octanol,
2-2-methyl-2-nonanol, 2-methyl-2-decanol, 3-methyl-3-hexanol, 3-methyl-3-heptanol,
4-methyl-4-heptanol, 3-methyl-3-octanol, 4-methyl-4-octanol, 3-methyl-3-nonanol, 4-methyl-4-nonanol,
3-methyl-3-octanol, 3-ethyl-3-hexanol, 3-mehtyl-3-heptanol, 4-ethyl-4-heptanol, 4-propyl-4-heptanol,
4-isopropyl-4-heptanol, 2,4-dimethyl-2-pentanol, 1-methylcyclopentanol, 1-ethylcyclopentanol,
1-ethylcyclopentanol, 3-hydroxy-3-methyl-1-butene, 4-hydroxy-4-methyl-1-cyclopentanol,
2-phenyl-2-propanol, 2-methoxy-2-methyl-2-propanol 2,3,4-trimethyl-3-pentanol, 3,7-dimethyl-3-octanol,
2-phenyl-2-butanol, 2-methyl-1-phenyl-2-propanol and 3-ethyl-3-pentanol.
[0082] Examples of useful carboxylic acids include C
2-C
16, carboxylic acids, with one or two carboxylic acid groups and optionally a phenyl
group. Specific examples include acetic acid, decanoic acid, dodecanoic acid, octanoic
acid, benzylic acid, and combinations thereof
[0083] A single alcohol or mixtures of two or more of the above-listed alcohols or two or
more alcohols according to the structure above can be used as the diluent to make
the polymer of this invention.
[0084] The diluent may be selected from secondary and tertiary alcohols having at least
4 carbons. Suitable examples include tert-butanol, tert-amyl alcohol, 2-butanol, 2-methyl-2-pentanol,
2,3-dimethyl-2-butanol, 3-methyl-3-pentanol, 3-ethyl-3-pentanol, and 3,7-dimethyl-3-octanol.
[0085] The diluent may be selected from hexanol, heptanol, octanol, nonanol, decanol, tert-butyl
alcohol, 3-methyl-3-pentanol, isopropanol, t- amyl alcohol, ethyl lactate, methyl
lactate, i-propyl lactate, 3,7-dimethyl-3-octanol, dimethyl formamide, dimethyl acetamide,
dimethyl propionamide, N methyl pyrrolidinone and mixtures thereof. Additional diluents
useful for this invention are disclosed in
US patent 6,020,445, and
US 2010-0280146 A1.
[0086] The diluent may be water soluble at processing conditions and readily washed out
of the lens with water in a short period of time. Suitable water soluble diluents
include 1-ethoxy-2-propanol, 1-methyl-2-propanol, t-amyl alcohol, tripropylene glycol
methyl ether, isopropanol, 1-methyl-2-pyrrolidone, N,N-dimethylpropionamide, ethyl
lactate, dipropylene glycol methyl ether, and mixtures thereof. The use of a water
soluble diluent allows the post molding process to be conducted using water only or
aqueous solutions which comprise water as a substantial component.
[0087] The diluents may be used in amounts up to 40% by weight of the total of all components
in the reactive mixture. The diluent(s) may be used in amounts less than about 30%
for example in amounts between 2 and 20% by weight of the total of all components
in the reactive mixture.
[0088] It has been found that even amounts of diluent as low as 2-20 wt%, can lower the
modulus of the resulting polymer by 20% and improve wettability of the resulting polymers
and lenses.
[0089] The diluent may also comprise additional components to lower the modulus of the resulting
polymers and improve the lens curing efficiency and reducing residuals. Components
capable of increasing the viscosity of the reactive mixture and/or increasing the
degree of hydrogen bonding with the slow-reacting hydrophilic monomer, are desirable.
Suitable components include polyamides, polylactams, such as PVP and copolymers thereof,
polyols and polyol containing components such glycerin, boric acid, boric acid glycerol
esters, polyalkylene glycols, and combinations thereof.
[0090] Suitable polylactams include PVP and copolymers comprising repeating units from NVP
and hydrophilic monomers. The polylactam may be selected from, PVP, and the polyamide
comprises DMA.
[0091] When polyamides or polylactams are used they have a molecular weight of between K12-K120
(3900 to 3,000,000 Dalton M
w) or from K30 to K90 (42,000 to 1,300,000 Dalton M
w).
[0092] Suitable polyalkylene glycols include polyethylene glycol and polypropylene glycols
having molecular weight up to 350, suitably less than 200 gm/mol.
[0093] When used, the polyols, polyol containing components, polyamides and polylactams
are used in amounts less than about 5 wt%, or from 0.2 to 5 wt%. The diluents and
co-diluents of the present invention also reduce the residuals remaining in the polymer
at the end of the photocure. This provides lenses with more consistent properties,
including diameter. The residual slow-reacting hydrophilic component present at the
end of cure may be less than 2 wt% cured polymer ((wt of residual component/wt of
cured polymer) * 100%), or less than 1 wt% and in some cases less than 0.8 wt%. The
reduction in residuals also leads to more consistent lens properties, including lens
diameters, which can vary by less than 0.05 mm.
[0094] The reactive mixture may contain additional components such as, but not limited to,
medicinal agents, antimicrobial compounds, reactive tints, pigments, copolymerizable
and non-polymerizable dyes, release agents and combinations thereof.
[0095] Combinations of reactive components and diluents include those having from 20 to
65 weight % silicone containing monomer, 25 to 70 weight % slow-reacting hydrophilic
monomer, from 2 to 40 weight % of an hydroxyl containing component, from 0.2 to 3
weight % of at least one crosslinking monomer, from 0 to 3 weight % of a UV absorbing
monomer, (all based upon the weight % of all reactive components). The mixture may
further comprises between 20 to 60 weight % (weight % of all components, both reactive
and non-reactive) of one or more diluents.
[0096] The reaction mixtures of the present invention can be formed by any of the methods
known to those skilled in the art, such as shaking or stirring, and used to form polymeric
articles or devices by known methods.
[0097] For example, the biomedical devices of the invention may be prepared by mixing reactive
components and the diluent(s) with a polymerization initiator and curing by appropriate
conditions to form a product that can be subsequently formed into the appropriate
shape by lathing, and cutting. Alternatively, the reaction mixture may be placed in
a mold and subsequently cured into the appropriate article.
[0098] Various processes are known for processing the reaction mixture in the production
of contact lenses, including spincasting and static casting. Spincasting methods are
disclosed in
U.S. Pat. Nos. 3,408,429 and
3,660,545, and static casting methods are disclosed in
U.S. Pat. Nos. 4,113,224 and
4,197,266. The method for producing contact lenses comprising the polymer of this invention
may be by the direct molding of the silicone hydrogels, which is economical, and enables
precise control over the final shape of the hydrated lens. For this method, the reaction
mixture is placed in a mold having the shape of the final desired silicone hydrogel,
i.e., water-swollen polymer, and the reaction mixture is subjected to conditions whereby
the monomers polymerize, to thereby produce a polymer/diluent mixture in the shape
of the final desired product.
[0099] Referring to Fig. 1, a diagram is illustrated of an ophthalmic lens 100, such as
a contact lens, and mold parts 101-102 used to form the ophthalmic lens 100. The mold
parts may include a back surface mold part 101 and a front surface mold part 102.
As used herein, the term "front surface mold part" refers to the mold part whose concave
surface 104 is a lens forming surface used to form the front surface of the ophthalmic
lens. Similarly, the term "back surface mold part" refers to the mold part 101 whose
convex surface 105 forms a lens forming surface, which will form the back surface
of the ophthalmic lens 100. Mold parts 101 and 102 may be of a concavo-convex shape,
preferably including planar annular flanges, which surround the circumference of the
uppermost edges of the concavo-convex regions of the mold parts 101-102.
[0100] Typically, the mold parts 101-102 are arrayed as a "sandwich". The front surface
mold part 102 is on the bottom, with the concave surface 104 of the mold part facing
upwards. The back surface mold part 101 can be disposed symmetrically on top of the
front surface mold part 102, with the convex surface 105 of the back surface mold
part 101 projecting partially into the concave region of the front surface mold part
102. The back surface mold part 101 may be dimensioned such that the convex surface
105 thereof engages the outer edge of the concave surface 104 of the front mold part
102 throughout its circumference, thereby cooperating to form a sealed mold cavity
in which the ophthalmic lens 100 is formed.
[0101] The mold parts 101-102 may be fashioned of thermoplastic and are transparent to polymerization-initiating
actinic radiation, by which is meant that at least some, and sometimes all, radiation
of an intensity and wavelength effective to initiate polymerization of the reaction
mixture in the mold cavity can pass through the mold parts 101-102.
[0102] For example, thermoplastics suitable for making the mold parts can include: polystyrene;
polyvinylchloride; polyolefin, such as polyethylene and polypropylene; copolymers
or mixtures of styrene with acrylonitrile or butadiene, polyacrylonitrile, polyamides,
polyesters, cyclic olefin copolymers such as Topas available from Ticona or Zeonor
available from Zeon, copolymers and blends of any of the foregoing, or other known
material.
[0103] Following polymerization of the reaction mixture to form a lens 100, the lens surface
103 will typically adhere to the mold part surface 104. The steps of the present invention
facilitate release of the surface 103 from the mold part surface. The first mold part
101 can be separated from the second mold part 102 in a demolding process. The lens
100 may have adhered to the second mold part 102 (i.e. the front curve mold part)
during the cure process and remain with the second mold part 102 after separation
until the lens 100 has been released from the front curve mold part 102. Alternatively,
the lens 100 can adhere to the first mold part 101.
[0104] The lens 100 may be released from the mold by any process, including contacting with
a solvent or dry release. For example, the lens 100 and the mold part to which it
is adhered after demolding may be contacted with an aqueous solution. The aqueous
solution can be heated to any temperature below the boiling point of the aqueous solution.
Heating can be accomplished with a heat exchange unit to minimize the possibility
of explosion, or by any other feasible means or apparatus for heating a liquid.
[0105] As used herein, processing includes the steps of removing the lens from the mold
and removing or exchanging the diluent with an aqueous solution. The steps may be
done separately, or in a single step or stage. The processing temperature may be any
temperatures between 30°C and the boiling point of the aqueous solutions, for example
between 30°C and 95°C, or between 50°C and 95°C.
[0106] The aqueous solution is primarily water. The aqueous solution may be at least 70
wt% water, at least 90 weight % water or at least 95%. The aqueous solution may also
be a contact lens packaging solution such as borate buffered saline solution, sodium
borate solutions, sodium bicarbonate solutions and the like. The aqueous solution
may also include additives, such as surfactants, preservatives, release aids, antibacterial
agents, pharmaceutical and nutriceutical components, lubricants, wetting agents, salts,
buffers, and mixtures thereof. Specific examples of additives which may be included
in the aqueous solution include Tween 80, which is polyoxyethylene sorbitan monooleate,
Tyloxapol, octylphenoxy (oxyethylene) ethanol, amphoteric 10), EDTA, sorbic acid,
DYMED, chlorhexadine gluconate, hydrogen peroxide, thimerosal, polyquad, polyhexamethylene
biguanide, mixtures thereof and the like. Where various zones are used, different
additives may be included in different zones. Additives may be added to the hydration
solution in amounts varying between 0.01% and 10% by weight, but cumulatively less
than about 10% by weight.
[0107] Exposure of the ophthalmic lens 100 to the aqueous solution can be accomplished by
any method, such as washing, spraying, soaking, submerging, or any combination of
the aforementioned. For example, the lens 100 can be washed with an aqueous solution
comprising deionized water in a hydration tower.
[0108] Using a hydration tower, front curve mold parts 102 containing lenses 100 can be
placed in pallets or trays and stacked vertically. The aqueous solution can be introduced
at the top of the stack of lenses 100 so that the solution will flow downwardly over
the lenses 100. The solution can also be introduced at various positions along the
tower. The trays can be moved upwardly allowing the lenses 100 to be exposed to increasingly
fresher solution.
[0109] Alternatively, the ophthalmic lenses 100 may be soaked or submerged in the aqueous
solution.
[0110] The contacting step can last up to 12 hours, up to 2 hours or from 2 minutes to 2
hours; however, the length of the contacting step depends upon the lens materials,
including any additives, the materials that are used for the solutions or solvents,
and the temperatures of the solutions. Sufficient treatment times typically shrink
the contact lens and release the lens from the mold part. Longer contacting times
will provide greater leaching.
[0111] The volume of aqueous solution used may be any amount greater than 1 ml/lens and
in some embodiments greater than 5 ml/lens.
[0112] After separation or demolding, the lenses on the front curves, which may be part
of a frame, are mated with individual concave slotted cups to receive the contact
lenses when they release from the front curves. The cups can be part of a tray. Examples
can include trays with 32 lenses each, and 20 trays that can be accumulated into a
magazine.
[0113] Alternatively, the lenses may be submerged in the aqueous solution. Magazines can
be accumulated and then lowered into tanks containing the aqueous solution. The aqueous
solution may also include other additives as described above.
[0114] The ophthalmic devices, and particularly ophthalmic lenses of the present invention
have a balance of properties which makes them particularly useful. Such properties
include clarity, optics, water content, oxygen permeability and advancing contact
angle. Thus, the biomedical devices may be contact lenses having a water content of
greater than 55%, greater than 60% .
[0115] As used herein clarity means substantially free from visible haze. Clear lenses have
a haze value of less than 70%, more preferably less than 50% and less than 10%.
[0116] Suitable oxygen permeabilities include those greater than 80 barrer, greater than
85 barrer, or at least about 100 barrer.
[0117] Also, the biomedical devices, and particularly ophthalmic devices and contact lenses
have moduli which are less than 1.03 MPa (150 psi) or less than 0.69MPa (100psi).
[0118] The biomedical devices, and particularly ophthalmic devices and contact lenses have
average advancing contact angles which are less than 80°, less than 75° or less than
70°. The articles of the present invention may have combinations of the above described
oxygen permeability, water content and contact angle. All combinations of the above
ranges are deemed to be within the present invention.
Hansen Solubility Parameter
Haze Measurement
[0120] Haze is measured by placing a hydrated test lens in borate buffered saline in a clear
20 x 40 x 10 mm glass cell at ambient temperature above a flat black background, illuminating
from below with a fiber optic lamp (Dolan-Jenner PL-900 fiber optic light with 1.27
cm (0.5") diameter light guide set at a power setting of 4-5.4) at an angle 66° normal
to the lens cell, and capturing an image of the lens from above, normal to the lens
cell with a video camera (DVC 1300C:19130 RGB camera with Navitar TV Zoom 7000 zoom
lens) placed 14 mm above the lens platform. The background scatter is subtracted from
the scatter of the lens by subtracting an image of a blank cell using EPIX XCAP V
2.2 software. The subtracted scattered light image is quantitatively analyzed, by
integrating over the central 10 mm of the lens, and then comparing to a -1.00 diopter
CSI Thin Lens®, which is arbitrarily set at a haze value of 100, with no lens set
as a haze value of 0. Five lenses are analyzed and the results are averaged to generate
a haze value as a percentage of the standard CSI lens.
Alternatively, instead of a -1.00 diopter CSI Thin Lenses®, a series of aqueous dispersions
of stock latex spheres (commercially available as 0.49 µm Polystyene Latex Spheres
- Certified Nanosphere Size Standards from Ted Pella, Inc., Product Number 610-30)
can be used as standards. A series of calibration samples were prepared in deionized
water. Each solution of varying concentration was placed in a cuvette (2mm path length)
and the solution haze was measured using the above method.
| Solution |
Concentration (wt% x 10-4) |
Mean GS |
| 1 |
10.0 |
533 |
| 2 |
6.9 |
439 |
| 3 |
5.0 |
379 |
| 4 |
4.0 |
229 |
| 5 |
2.0 |
172 |
| 6 |
0.7 |
138 |
| Mean GS = mean gray scale |
A corrective factor was derived by dividing the slope of the plot of Mean GS against
the concentration (47.1) by the slope of an experimentally obtained standard curve,
and multiplying this ratio times measured scatter values for lenses to obtain GS values.
[0121] "CSI haze value" may be calculated as follows:

Where GS is gray scale and BS is background scatter.
Water Content
[0122] The water content of contact lenses was measured as follows: Three sets of three
lenses are allowed to sit in packing solution for 24 hours. Each lens is blotted with
damp wipes and weighed. The lenses are dried at 60°C for four hours at a pressure
of 0.4 inches Hg or less. The dried lenses are weighed. The water content is calculated
as follows:

[0123] The average and standard deviation of the water content are calculated for the samples
and are reported.
Modulus
[0124] Modulus is measured by using the crosshead of a constant rate of movement type tensile
testing machine equipped with a load cell that is lowered to the initial gauge height.
A suitable testing machine includes an Instron model 1122. A dogbone shaped sample
having a 0.522 inch length, 0.276 inch "ear" width and 0.213 inch "neck" width is
loaded into the grips and elongated at a constant rate of strain of 2 in/min. until
it breaks. The initial gauge length of the sample (Lo) and sample length at break
(Lf) are measured. Twelve specimens of each composition are measured and the average
is reported. Percent elongation is = [(Lf - Lo)/Lo]x 100. Tensile modulus is measured
at the initial linear portion of the stress/strain curve.
Advancing Contact Angle
[0125] All contact angles reported herein are advancing contact angles. The advancing contact
angle was measured as follows. Four samples from each set were prepared by cutting
out a center strip from the lens approximately 5 mm in width and equilibrated in packing
solution. The wetting force between the lens surface and borate buffered saline is
measured at 23°C using a Wilhelmy microbalance while the sample is being immersed
into or pulled out of the saline. The following equation is used

or

where F is the wetting force, γ is the surface tension of the probe liquid, p is
the perimeter of the sample at the meniscus and θ is the contact angle. The advancing
contact angle is obtained from the portion of the wetting experiment where the sample
is being immersed into the packing solution. Each sample was cycled four times and
the results were averaged to obtain the advancing contact angles for the lens.
Oxygen Permeability (Dk)
[0126] The Dk is measured as follows. Lenses are positioned on a polarographic oxygen sensor
consisting of a 4 mm diameter gold cathode and a silver ring anode then covered on
the upper side with a mesh support. The lens is exposed to an atmosphere of humidified
2.1% O
2. The oxygen that diffuses through the lens is measured by the sensor. Lenses are
either stacked on top of each other to increase the thickness or a thicker lens is
used. The L/Dk of 4 samples with significantly different thickness values are measured
and plotted against the thickness. The inverse of the regressed slope is the Dk of
the sample. The reference values are those measured on commercially available contact
lenses using this method. Balafilcon A lenses available from Bausch & Lomb give a
measurement of approx. 79 barrer. Etafilcon lenses give a measurement of 20 to 25
barrer. (1 barrer = 10
-10 (cm
3 of gas x cm
2)/(cm
3 of polymer x sec x cm Hg)).
Lysozyme, Lipocalin & Mucin Uptake
[0127] Lysozyme uptake was measured as follows: The lysozyme solution used for the lysozyme
uptake testing contained lysozyme from chicken egg white (Sigma, L7651) solubilized
at a concentration of 2 mg/ml in phosphate saline buffer supplemented by Sodium bicarbonate
at 1.37g/l and D-Glucose at 0.1 g/l.
[0128] Three lenses for each example were tested using each protein solution, and three
were tested using PBS (phosphate buffered saline) as a control solution. The test
lenses were blotted on sterile gauze to remove packing solution and aseptically transferred,
using sterile forceps, into sterile, 24 well cell culture plates (one lens per well)
each well containing 2 ml of lysozyme solution. Each lens was fully immersed in the
solution. 2 ml of the lysozyme solution was placed in a well without a contact lens
as a control.
[0129] The plates containing the lenses and the control plates containing only protein solution
and the lenses in the PBS, were parafilmed to prevent evaporation and dehydration,
placed onto an orbital shaker and incubated at 35°C, with agitation at 100 rpm for
72 hours. After the 72 hour incubation period the lenses were rinsed 3 to 5 times
by dipping lenses into three (3) separate vials containing approximately 200 ml volume
of PBS. The lenses were blotted on a paper towel to remove excess PBS solution and
transferred into sterile conical tubes (1 lens per tube), each tube containing a volume
of PBS determined based upon an estimate of lysozyme uptake expected based upon on
each lens composition. The lysozyme concentration in each tube to be tested needs
to be within the albumin standards range as described by the manufacturer (0.05 micogram
to 30 micrograms). Samples known to uptake a level of lysozyme lower than 100 µg per
lens were diluted 5 times. Samples known to uptake levels of lysozyme higher than
500 µg per lens (such as etafilcon A lenses) are diluted 20 times.
[0130] 1 ml aliquot of PBS was used for all samples other than etafilcon. 20ml were used
for etafilcon A lens. Each control lens was identically processed, except that the
well plates contained PBS instead of lysozyme solution.
[0131] Lysozyme uptake was determined using on-lens bicinchoninic acid method using QP-BCA
kit (Sigma, QP-BCA) following the procedure described by the manufacturer (the standards
prep is described in the kit) and is calculated by subtracting the optical density
measured on PBS soaked lenses (background) from the optical density determined on
lenses soaked in lysozyme solution.
[0132] Optical density was measured using a SynergyII Micro-plate reader capable for reading
optical density at 562nm.
[0133] Lipocalin uptake was measured using the following solution and method. The lipocalin
solution contained B Lactoglobulin (Lipocalin) from bovine milk (Sigma, L3908) solubilized
at a concentration of 2 mg/ml in phosphate saline buffer (Sigma, D8662) supplemented
by sodium bicarbonate at 1.37g/l and D-Glucose at 0.1 g/l.
[0134] Three lenses for each example were tested using the lipocalin solution, and three
were tested using PBS as a control solution. The test lenses were blotted on sterile
gauze to remove packing solution and aseptically transferred, using sterile forceps,
into sterile, 24 well cell culture plates (one lens per well) each well containing
2 ml of lipocalin solution. Each lens was fully immersed in the solution. Control
lenses were prepared using PBS as soak solution instead of lipocalin. The plates containing
the lenses immersed in lipocalin solution as well as plates containing control lenses
immersed in PBS, were parafilmed to prevent evaporation and dehydration, placed onto
an orbital shaker and incubated at 35°C, with agitation at 100 rpm for 72 hours. After
the 72 hour incubation period the lenses were rinsed 3 to 5 times by dipping lenses
into three (3) separate vials containing approximately 200 ml volume of PBS. The lenses
were blotted on a paper towel to remove excess PBS solution and transferred into sterile
24 well plates each well containing 1 ml of PBS solution.
[0135] Lipocalin uptake was determined using on-lens bicinchoninic acid method using QP-BCA
kit (Sigma, QP-BCA) following the procedure described by the manufacturer (the standards
prep is described in the kit) and is calculated by subtracting the optical density
measured on PBS soaked lenses (background) from the optical density determined on
lenses soaked in lipocalin solution. Optical density was measured using a SynergyII
Micro-plate reader capable for reading optical density at 562nm.
[0136] Mucin uptake was measured using the following solution and method. The Mucin solution
contained Mucins from bovine submaxillary glands (Sigma, M3895-type 1-S) solubilized
at a concentration of 2 mg/ml in phosphate saline buffer (Sigma, D8662) supplemented
by sodium bicarbonate at 1.37g/l and D-Glucose at 0.1 g/l.
[0137] Three lenses for each example were tested using Mucin solution, and three were tested
using PBS as a control solution. The test lenses were blotted on sterile gauze to
remove packing solution and aseptically transferred, using sterile forceps, into sterile,
24 well cell culture plates (one lens per well) each well containing 2 ml of Mucin
solution. Each lens was fully immersed in the solution. Control lenses were prepared
using PBS as soak solution instead of lipocalin.
[0138] The plates containing the lenses immersed in Mucin as well as plates containing control
lenses immersed in PBS were parafilmed to prevent evaporation and dehydration, placed
onto an orbital shaker and incubated at 35°C, with agitation at 100 rpm for 72 hours.
After the 72 hour incubation period the lenses were rinsed 3 to 5 times by dipping
lenses into three (3) separate vials containing approximately 200 ml volume of PBS.
The lenses were blotted on a paper towel to remove excess PBS solution and transferred
into sterile 24 well plates each well containing 1 ml of PBS solution.
[0139] Mucin uptake was determined using on-lens bicinchoninic acid method using QP-BCA
kit (Sigma, QP-BCA) following the procedure described by the manufacturer (the standards
prep is described in the kit) and is calculated by subtracting the optical density
measured on PBS soaked lenses (background) from the optical density determined on
lenses soaked in Mucin solution. Optical density was measured using a SynergyII Micro-plate
reader capable for reading optical density at 562nm.
Kinetics
Preparation of Reactive Monomer Mixes: 15 - 20 g batch
[0140] The preparation of the reactive monomer mixtures for the kinetics studies were prepared
under yellow light as follows. The components for each kinetics example were weighed
into a 20 mL amber borosilicate glass scintillation vial (Wheaton 320 brand; Catalogue
# 80076-576, or equivalent). Vials were capped (using PTFE lined green cap, Qorpak;
Supplier # 5205/100, Catalogue # 16161-213) and rolled on jar roller until all solids
were dissolved and a homogeneous mixtures were obtained.
Degas
[0141] Reactive monomer mixes were degassed under vacuum, under yellow light for 7 - 10
minutes, and back-filling with nitrogen after breaking vacuum. Vials were quickly
capped and placed in compartment 1 of a two compartment nitrogen cure box, via the
gated aperature, 7, as shown in Figure 2. The conditions in compartment 1 were room
temperature and <0.5% oxygen (using continuous nitrogen purge).
Nitrogen Cure Box - Compartment 2
[0142] The oxygen level in both compartments was maintained by continuous/constant nitrogen
purge. The temperature in Compartment 2 was maintained by a heater (COY, Laboratory
Products Inc.). The nitrogen cure box was allowed to equilibrate for a minimum of
4 hours prior to performing each kinetics study. The degassed reactive mixture (in
tightly capped abmber vial) was placed in compartment 1 during the equilibration period.
Light Source and Intensity Setting
[0143] As depicted in Figure 3, 2 fluorescent light fixtures (Lithonia Lighting Fluorescent
Luminaire (Gas Tube Luminaire), 60 cm x 10.5 cm) each equipped with 2 fluorescent
lamps (Philips TLK 40W/03, 58 cm) were arranged in parallel. The cure intensity was
attenuated by adjusting the height of the shelf (shown in Figures 2 and 3) relative
to the light source. The intensity at a given shelf height was measured by placing
the sensor of a calibrated radiometer/photometer on the mirrored surface, consistent
with the position of the sample, as shown in Figure 3. The sensor was placed directly
under the space between the 2
nd and 3
rd lamps in the 4 lamps arrangement.
[0144] Using a calibrated analytical balance (4 decimal places) the weight of a clear borosilicate
glass scintillation vial (Wheaton 986541) with cap (white cap with polyethylene insert)
was determined. The vial with cap was transferred to Compartment 1 of the Nitrogen
Cure Box. The cap was unscrewed and using a calibrated 10 - 100 µL Eppendorf Pipet,
100 µL of the Reactive Monomer Mixture was transferred into the vial. The vial was
tightly capped, quickly moved into Compartment 2, via door 6, and placed on the mirrored
surface 4, as shown in Figure 2. The sample was placed directly under the space between
the 2
nd and 3
rd lamps in the 4 lamps arrangement. The light source 3, was turned on and the sample
was exposed for a specified time period. Although the light source was set at 4 -
5 mW/cm
2, the actual intensity reaching the sample is 0.7 - 1.3 mW/cm
2, due the cap on the sample glass vials. After exposure, the light source 3,was turned
off and the vial (with cap) was re-weighed to determine the sample weight by difference.
Using a calibrated 500 - 5000 µL Eppendorf Pipet, 10 mL HPLC grade methanol was added
to the vial.
[0145] Aliquots (100 µL) of the Reactive Monomer Mixture were pipetted into separate borosilicate
glass scintillation vials and the above procedure described above was performed to
generate samples at the following minimum time points (minutes): 0, 0.25, 0.50, 0.75,
1, 2, 4, 6, 8, 10.
Cured polymers were extracted in methanol overnight by gently shaking at room temperature.
[0146] Extracts were analyzed for residual components by High Performance Liquid Chromatography
with UV detection (HPLC/UV) using the following procedures.
[0147] Quantitation of the mPDMS in the extracts was performed against external calibration
standards (about 6 - 11, using the response of the n=6 oligomer), typically covering
the range of 1 µg/mL - 800 µg/mL. If the concentrations of mPDMS in the extracts were
outside the calibration range, the extracts were diluted with methanol to render concentrations
within the calibration range for more accurate quantitation.
Chromatographic Conditions
[0148]
Column: Agilent Zorbax Eclipse XDB18, 4.6 x 50 mm x 1.8 µm
Column Temperature: 30 °C
UV Detector: 217 nm
Injection Volume: 20 µL
Mobile Phase
Eluent A: De-ionized
Eluent B: Acetonitrile
Eluent C: Isopropanol
Flow Rate: 1 mL/min
| Time (mins) |
%A |
%B |
%C |
| 0.0 |
50 |
48 |
2 |
| 0.5 |
50 |
48 |
2 |
| 2.0 |
0 |
60 |
40 |
| 5.0 |
0 |
60 |
40 |
| 5.1 |
0 |
30 |
70 |
| 8.0 |
0 |
30 |
70 |
| 8.1 |
50 |
48 |
2 |
| 10.0 |
50 |
48 |
2 |
[0149] Quantitation of the components in the extracts other than mPDMS was performed against
external calibration standards (about 6 - 11) for each component, typically covering
the range of 1 µg/mL - 800 µg/mL. If the concentrations of components in the extracts
were outside the calibration range, the extracts were appropriately diluted with methanol
to render concentrations within the calibration range for more accurate quantitation.
Chromatographic Conditions
[0150]
Column: Agilent Zorbax Eclipse Plus 18, 4.6 x 75 mm x 1.8 µm
Column Temperature: 30 °C
UV Detector: 217 nm
Injection Volume: 5 µL
Mobile Phase
Eluent A: De-ionized water with 0.05% H3PO4
Eluent B: Acetonitrile with 0.05% H3PO4
Eluent C: Methanol
Flow Rate: 1 mL/min
| Time (mins) |
%A |
%B |
%C |
| 0 |
95 |
5 |
0 |
| 5 |
95 |
5 |
0 |
| 15 |
0 |
100 |
0 |
| 23 |
0 |
100 |
0 |
| 24 |
0 |
30 |
70 |
| 28 |
0 |
30 |
70 |
| 29 |
95 |
5 |
0 |
| 35 |
95 |
5 |
0 |
Calculations
[0151]
- 1. At each time point the following values are determined:
The concentration (µg/mL) of each component in the sample extract.
The concentration of each component in the sample extract, expressed as a percent
of the sample weight as follows:

The percent unreacted component present, expressed as a percent relative to T0 (where T0 represented 100 % unreacted component)

- 2. Using the % Component calculated above, the concentration of each component in
µmoles/g, is calculated as follows:

- 3. Using the concentration of each component determined in µmoles/g in step 2, the
concentration at Timex was expressed as

where [Ax] is the concentration of component A at x minutes and [Ao] is the concentration of component A at 0 minutes (T0)
[0152] The expression Log [A
x]/[A
o] was determined for each time point.
[0153] First order kinetics were assumed for determining both the polymerization kinetics
rate and half life for each component. The following equations were used for calculating
polymerization rate

and half life

For each component, a plot of Log [A
x]/[A
0] versus time (minutes) was generated. Typically, the data points (x, y) that best
correspond to linear growth (shorter cure times) were plotted and the data were fitted
to a linear equation.
[0154] Using the slope, the kinetic rate constant (k) of each component was evaluated from
the following equation:

[0155] The half-life (minutes) of each component was evaluated from the following equation:

[0156] The evaluated half-life for each component was compared to the data generated for
the percent of each component relative to T
0, at each time point. Typically for each component, the time taken to attain 50% consumption
was close to the half-life based on 1
st order kinetics In cases where the two were significantly different (typically about
30% for half-life of less than about 1 minute, 25% for half-life less than about 2.5
minutes but greater than 1minute and 20% for half-life greater than 2.5 minutes),
the data points (x, y) were re-evaluated to generate kinetic rate constants (k) which
would provide half-lives (based on 1
st order considerations) more consistent (within 20%) with the measured values.
[0157] The Examples below further describe this invention, but do not limit the invention.
They are meant only to suggest a method of practicing the invention. Those knowledgeable
in the field of contact lenses as well as other specialties may find other methods
of practicing the invention. However, those methods are deemed to be within the scope
of this invention.
[0158] Some of the other materials that are employed in the Examples are identified as follows:
EXAMPLES
[0159] The following abbreviations are used in the examples below:
| FC |
Front mold curves |
| BC |
Back mold curves |
| SiMAA |
(3-methacryloxy-2-hydroxypropoxy)propyl-bis(trimethylsiloxy)methylsilane (Also known
as SiGMA) |
| DMA |
N,N-dimethylacrylamide |
| EGVE |
ethylene glycol vinyl ether |
| HEMA |
2-hydroxyethyl methacrylate |
| HEAA |
hydroxyethylacrylamide |
| HBMA |
2-hydroxybutyl methacrylate, prepared as in Example 118 |
| HPMA |
2-hydroxypropyl methacrylate (ACROS) |
| DMHEMA |
dimethylhydroxyethylmethacrylate, prepared as in Example 119 |
| mPDMS |
800-1000 MW (Mn) monomethacryloxypropyl terminated mono-n-butyl terminated polydimethylsiloxane |
| OH-mPDMS |
α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-decamethylpentasiloxane, (MW 612g/mol),
prepared as in Example 8 of US201002499 356 A1 |
| Norbloc |
2-(2'-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole |
| D3O |
3,7-dimethyl-3-octanol |
| IPA |
isopropyl alcohol |
| TAC |
triallylcyanurate |
| TEGDMA |
tetraethyleneglycol dimethacrylate |
| TRIS |
3-methacryloxypropyltris(trimethylsiloxy)silane |
| acPDMS |
bis-3-methacryloxy-2-hydroxypropyloxypropyl polydimethylsiloxane (MW about 1000 g/mole) |
| CGI 819 |
bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide |
| EtOAc |
ethyl acetate |
| DA |
decanoic acid |
| Macromer A |
Described in Example 25 of US 6,943,203 |
| GMMA |
2,3-dihydroxypropyl methacrylate |
| TAA |
t-amyl alcohol |
| ETOH |
ethanol |
| SA-2 |
N-(2,3-dihydroxypropane)-N'-(propyl tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide,
as shown in Formula XI |

|
| VMA |
N-vinyl-N-methyl acetamide |
| NVP |
N-vinylpyrrolidone |
| BHT |
butylated hydroxytoluene |
| PVP |
poly(N-vinylpyrrolidone) |
| EGVE |
ethyleneglycol vinyl ether |
| VINAL |
an ionic amide containing vinyl ether having the structure |

|
| and prepared in Example 120 |
BAE (Boric Acid Ester) was formed as follows:
1.24 parts of a 5% (wt) solution of ethylenediaminetetraacetic acid, 299 parts (wt)
glycerol and 100 parts (wt) boric acid were added to a reaction flask. The mixture
was heated with stirring to 90°C. Vacuum was applied to reduce the pressure to less
than 6 torr as the mixture was stirred for 155 minutes, with removal of water vapor.
The pressure was reduced to less than 2 torr and the reaction was continued for 2
hours, or longer as needed until the % water of the mixture was reduced to less than
0.2% using a Karl Fischer test.
[0160] BAGE (Boric Acid Glycerol Ester) was formed as follows:
To BAE prepared as described above was added 624 parts (wt) glycerol with stirring
for 60 minutes at 35-40°C.
Example 1 and Comparative Example 1
[0161] A reaction mixture was formed by mixing the components listed in Table 1 and degassed
by applying vacuum at ambient temperature for about 17(±3) minutes. The reaction mixture
(75 µL) was then dosed at room temperature and <0.5% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold to produce 8 BC/FC assemblies in a pallet. Eight pallets
were assembled and moved into the cure compartment (Compartment 2, Figure 2). Pallets
were placed on a mirrored surface and a quartz plate (0.50 mm thick) was placed over
each pallet. The lenses were cured for 18 minutes, at an intensity of 4 - 5 mW/cm
2, <0.5% O
2, and 50 - 55 °C.
[0162] The molds were manually demolded (lenses remained in FC) and lenses were released
in 50/50 IPA/H
2O (8 pallets, 8 lenses per pallet), 1 L solution, 1 hour.
[0163] Lenses were "stepped down" into PS in the following order:
25/75IPA/H
2O (10 mins), H
2O (30 mins), H
2O (10 mins), H
2O (10 mins), and stored in borate buffered packing solution in lens vials and sterilized
at 122°C for 30 minutes.
Table 1
| Component |
Ex. 1 NVP |
CE 1 DMA |
| OH-mPDMS, n=4 |
40 |
40 |
| NVP |
50.5 |
0 |
| DMA |
0 |
50.5 |
| HEMA |
6.75 |
6.75 |
| TEGDMA |
0.5 |
0.5 |
| Norblock |
2 |
2 |
| CGI 819 |
0.25 |
0.25 |
Table 2
| Ex. # |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 1 |
58.4 (0.2) |
4 (0) |
44 (4) |
102.9 (11.4) |
220.3 (36.2) |
74.7 |
| CE1 |
59.8 (0.1) |
5 (1) |
127 (14) |
54.1 (7.4) |
227.3 (52.3) |
48.5 |
[0164] The lenses of Example 1 exhibited exceptional haze (4%), wettability (DCA 44°), modulus,
elongation and Dk. The lenses of Comparative Example 1 exhibited greatly increased
advancing contact angle (127°), indicating a marked decrease in wettability. Comparative
Example 1 also displayed a substantially reduced modulus (54.1 psi) and oxygen permeability
(48.5) compared to Example 1 (102.9 and 74.7, respectively).
Examples 2 and Comparative Example 2
[0165] The polymerization rate and half life for each component in the Formulations of Example
1 and Comparative Example 1 were determined using the procedure described in the kinetics
section above. In each Example, for each of the components in the sample extract and
at each of the time points the following information is reported, the wt% of each
residual component measured (Table 3), % incorporation of each residual component
at each time point relative to the % residual measured at T
0 (Table 4), the µmole/g of each residual component at each time point (Table 5) and,
log[A]/[A
0] (Table 6), and the polymerization rate constants and half-lives (Tables 7 and 8).
Table 3
| |
Ex. 2 RESIDUAL MONOMERS WT% |
| Cure Time |
NVP |
HEMA |
TEGDMA |
Norbloc |
CGI 819 |
OH-mPDMS |
| 0.00 |
48.687 |
6.612 |
0.493 |
2.036 |
0.211 |
36.999 |
| 0.25 |
50.127 |
5.740 |
0.377 |
1.805 |
0.167 |
33.584 |
| 0.50 |
50.053 |
4.958 |
0.303 |
1.602 |
0.129 |
29.903 |
| 1.00 |
48.037 |
3.611 |
0.185 |
1.152 |
0.067 |
22.854 |
| 2.00 |
45.327 |
1.722 |
0.072 |
0.554 |
0.020 |
11.709 |
| 4.00 |
37.315 |
0.520 |
0.030 |
0.085 |
0.002 |
3.724 |
| 6.00 |
34.959 |
0.439 |
0.027 |
0.037 |
|
3.393 |
| 8.00 |
32.155 |
0.330 |
0.021 |
0.016 |
|
2.562 |
| 10.00 |
24.624 |
|
|
|
|
|
| 12.00 |
21.977 |
|
|
|
|
|
| 15.00 |
17.041 |
|
|
|
|
|
| 20.00 |
8.579 |
|
|
|
|
|
| 30.00 |
3.241 |
|
|
|
|
|
Table 4
| Ex. 2 % Incorporation |
| |
% |
% |
% |
% |
% |
% |
| Cure Time |
NVP |
HEMA |
TEGDMA |
Norbloc |
CGI 819 |
OH-mPDMS |
| 0.00 |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
| 0.25 |
102.96 |
86.81 |
76.49 |
88.65 |
79.13 |
90.77 |
| 0.50 |
102.81 |
74.99 |
61.35 |
78.69 |
61.15 |
80.82 |
| 1.00 |
98.67 |
54.61 |
37.56 |
56.59 |
31.64 |
61.77 |
| 2.00 |
93.10 |
26.04 |
14.55 |
27.19 |
9.44 |
31.65 |
| 4.00 |
76.64 |
7.86 |
6.10 |
4.18 |
1.04 |
10.06 |
| 6.00 |
71.80 |
6.63 |
5.45 |
1.81 |
|
9.17 |
| 8.00 |
66.04 |
4.99 |
4.15 |
0.77 |
|
6.92 |
| 10.00 |
50.58 |
|
|
|
|
|
Table 5
| Ex. 2 RESIDUAL MONOMERS (umoles/g) |
| Cure Time (mins) |
NVP |
HEMA |
TEGDMA |
Norbloc |
CGI 819 |
OH-mPDMS |
| 0.00 |
4386.23 |
508.60 |
17.25 |
62.66 |
5.04 |
604.57 |
| 0.25 |
4515.93 |
441.52 |
13.20 |
55.55 |
3.99 |
548.76 |
| 0.50 |
4509.28 |
381.39 |
10.58 |
49.31 |
3.08 |
488.62 |
| 1.00 |
4327.69 |
277.76 |
6.48 |
35.46 |
1.60 |
373.43 |
| 2.00 |
4083.51 |
132.44 |
2.51 |
17.04 |
0.48 |
191.32 |
| 4.00 |
3361.70 |
39.99 |
1.05 |
2.62 |
0.05 |
60.85 |
| 6.00 |
3149.41 |
33.74 |
0.94 |
1.14 |
|
55.44 |
| 8.00 |
2896.87 |
25.37 |
0.72 |
0.48 |
|
41.86 |
| 10.00 |
2218.40 |
|
|
|
|
|
Table 6
| |
NVP |
HEMA |
TEGDMA |
Norblock |
CGI 819 |
OH-mPDMS |
| Cure Time |
Log[A]/[A0] |
Log[A]/[A0] |
Log[A]/[A0] |
Log[A]/[A0] |
Log[A]/[A0] |
Log[A]/[A0] |
| 0.25 |
0.0127 |
-0.0614 |
-0.1164 |
-0.0523 |
-0.1017 |
-0.0421 |
| 0.50 |
0.0120 |
-0.1250 |
-0.2122 |
-0.1041 |
-0.2136 |
-0.0925 |
| 1.00 |
-0.0058 |
-0.2627 |
-0.4253 |
-0.2473 |
-0.4997 |
-0.2092 |
| 2.00 |
-0.0311 |
-0.5844 |
-0.8371 |
-0.5656 |
-1.0250 |
-0.4997 |
| 4.00 |
-0.1155 |
-1.1044 |
-1.2146 |
-1.3784 |
-1.9814 |
-0.9972 |
| 6.00 |
-0.1439 |
-1.1783 |
-1.2634 |
-1.7418 |
|
-1.0377 |
| 8.00 |
-0.1802 |
-1.3021 |
-1.3814 |
-2.1130 |
|
-1.1596 |
| 10.00 |
-0.2961 |
|
|
|
|
|
Table 7
| Ex. 2 |
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2),min |
| NVP |
0.25 - 8 min |
0.973 |
-0.0265 |
0.0610 |
11.36 |
| HEMA |
0.25 - 4 min |
0.998 |
-0.2810 |
0.6471 |
1.07 |
| TEGDMA |
0.25 - 4 min |
0.963 |
-0.2951 |
0.6796 |
1.02 |
| Norblock |
0.25 - 4 min |
0.993 |
-0.3568 |
0.8217 |
0.84 |
| CGI 819 |
0.25 - 4 min |
0.999 |
-0.5037 |
1.1600 |
0.60 |
| OH-mPDMS |
0.25 - 4 min |
0.999 |
-0.2582 |
0.5946 |
1.17 |
Table 8
| CE 2 |
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| DMA |
0.25 - 8 min |
0.975 |
-0.1496 |
0.3445 |
2.01 |
| HEMA |
0.25 - 4 min |
0.978 |
-0.2167 |
0.4991 |
1.39 |
| TEGDMA |
0.25 - 4 min |
0.971 |
-0.2254 |
0.5191 |
1.34 |
| Norblock |
0.25 - 4 min |
0.976 |
-0.1873 |
0.4314 |
1.61 |
| CGI 819 |
0.25 - 4 min |
0.981 |
-0.3088 |
0.7112 |
0.97 |
| OH-mPDMS |
0.25 - 4 min |
0.988 |
-0.1814 |
0.4178 |
1.66 |
Table 9
| Ex.# |
2 |
CE2 |
| Hydrophile (HP) |
NVP |
DMA |
| HP ½ life |
11.36 |
2.01 |
| Si ½ life |
1.17 |
1.66 |
| HP/Si |
9.7 |
1.2 |
| [µmol HP/µmol Si] @90% conversion of Si |
55.25 |
9.27 |
[0166] In Example 2, the half-life of the NVP is nearly ten times slower (11.36 minutes)
than the half-lives for the other monomers HEMA (1.07) and OH-mPDMS (1.17). In Comparative
Example 1, the half-life of the DMA (2.01) is nearly the same as the half life of
the silicone-containing component, OH-mPDMS (1.66). It is believed that the difference
in wettability between the formulations of Example 1 and Comparative Example 1 is
due to the substantially slower polymerization of the slow-reacting hydrophilic monomer
in Example 1 (NVP) as compared to the hydrophilic monomer in Comparative Example 1
(DMA). Table 9 also shows that at 90% conversion of the silicone monomer, the molar
ratio of the unreacted slow-reacting hydrophilic monomer NVP, compared to the unreacted
silicone (mPDMS), is 55.25 for NVP, and only 9.27 for the DMA system. The NVP containing
system displays improved wettability, as measured by advancing contact angle, and
increased oxygen permeability. The modulus of the DMA-containing formulation was substantially
lower, which is believed to be an indication that the DMA and silicone monomers are
more randomly incorporated in network. NVP system is believed to have larger blocks
of silicone and NVP. Moreover the ratio of the kinetic half lives for the Comparative
Example 2 system containing DMA as the hydrophile (1.21) is insufficient to provide
a wettable lens. The ratio of molar concentrations of DMA and HO-PDMS for Comparative
Example 1 was less than 10 (9.74).
Examples 3-5 and Comparative Example 3 (Examples 3 and 4 are reference examples)
[0167] The preparation described in Example 1 and kinetics evaluation described in Example
2 were repeated for the formulations listed in Table 10 below. The formulations for
Example 2 and Comparative Example 2 are listed in Table 10 for convenience. Tables
11- 14 show a summary of the calculated kinetics data for Examples 3-5 and Comparative
Example 3, and Table 15 shows the ratios of slow hydrophilic component to the silicone
component. The kinetics data for Example 2 and Comparative Example 2 is shown in Tables
5 and 6, above.
Table 10
| Comp. |
Ex. 2 |
Ex. 3 |
CE2 |
CE 3 |
Ex. 4 |
Ex. 5 |
| OH-mPDMS |
40 |
40 |
40 |
40 |
0 |
0 |
| SA2 |
0 |
0 |
0 |
0 |
41 |
40 |
| NVP |
50.5 |
50.5 |
0 |
0 |
51.5 |
50.5 |
| DMA |
0 |
0 |
50.5 |
50.5 |
0 |
0 |
| HEMA |
6.75 |
8.75 |
6.75 |
8.75 |
6.75 |
6.75 |
| TEGDMA |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
| Norblock |
2 |
0 |
2 |
0 |
0 |
2 |
| CGI 819 |
0.25 |
0.25 |
0.25 |
0.25 |
0.25 |
0.25 |
Table 11: Summary of Example 3 Kinetic Calculations
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 4 min |
0.869 |
-0.1133 |
0.2609 |
2.66 |
| HEMA |
0.25 - 8 min |
0.869 |
-0.2911 |
0.6704 |
1.03 |
| TEGDMA |
0.25 - 4 min |
0.998 |
-0.5114 |
1.1778 |
0.59 |
| CGI 819 |
0.25 - 4 min |
1.000 |
-0.5228 |
1.2040 |
0.58 |
| OH-mPDMS |
0.25 - 2 min |
0.987 |
-0.3080 |
0.7093 |
0.98 |
Table 12: Summary of Comparative Example 3 Kinetics Calculations
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| DMA |
0.25 - 2 min |
0.993 |
-0.1736 |
0.3998 |
1.73 |
| HEMA |
0.25 - 1 min |
0.989 |
-0.3734 |
0.8599 |
0.81 |
| TEGDMA |
0.25 - 2 min |
0.993 |
-0.5279 |
1.2158 |
0.57 |
| CGI 819 |
0.25 - 2 min |
0.991 |
-0.5106 |
1.1759 |
0.59 |
| OH-mPDMS |
0.25 - 1 min |
0.987 |
-0.3262 |
0.7512 |
0.92 |
Table 13: Summary of Example 4 Kinetics Calculations
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 1 min |
0.944 |
-0.1839 |
0.4235 |
1.64 |
| HEMA |
0.25 - 2 min |
0.970 |
-1.1455 |
2.6381 |
0.26 |
| TEGDMA |
0.25 - 2 min |
0.942 |
-1.0470 |
2.411 |
0.29 |
| CGI 819 |
0.25 - 4 min |
0.959 |
-0.3555 |
0.8187 |
0.85 |
| SA2 |
0.25 - 2 min |
0.913 |
-0.7599 |
1.7500 |
0.40 |
Table 14: Summary of Example 5 Kinetics Calculations
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 1 min |
0.891 |
-0.0630 |
0.1451 |
4.78 |
| HEMA |
0.25 - 2 min |
0.947 |
-1.2118 |
2.7908 |
0.25 |
| TEGDMA |
0.25 - 2 min |
0.886 |
-2.1365 |
4.9204 |
0.14 |
| Norbloc |
0.25 - 2 min |
0.981 |
-1.4710 |
3.3877 |
0.20 |
| CGI 819 |
0.25 - 2 min |
0.988 |
-0.4677 |
1.0771 |
0.64 |
| SA2 |
0.25 - 2 min |
0.712 |
-0.4544 |
1.0465 |
0.66 |
Table 15
| Ex.# |
2 |
3 |
CE2 |
CE3 |
4 |
5 |
| Norbloc |
Y |
N |
Y |
N |
N |
Y |
| Hydrophile |
NVP |
NVP |
DMA |
DMA |
NVP |
NVP |
| HP ½ life |
11.36 |
2.66 |
2.01 |
1.73 |
1.64 |
4.78 |
| Silicone |
HO-mPDMS |
HO-mPDMS |
HO-mPDMS |
HO-mPDMS |
SA2 |
SA2 |
| Si ½ life |
1.17 |
0.98 |
1.66 |
0.92 |
0.4 |
0.66 |
| HP/Si |
9.7 |
2.7 |
1.2 |
1.88 |
4.1 |
7.24 |
| [µmol HP/µmol Si] @90% conversion |
55.25 |
40.21 |
9.27 |
8.99 |
55.79 |
60.23 |
[0168] Considering the data in Table 15, including a UV absorbing compound in a photoinitiated
reactive monomer mixture causes the half life of the slow-reacting hydrophilic monomer
NVP to increase by between 60 and 400%, while the half life of DMA increases marginally
from 1.73 to 2.01 (16%). The half life of the HO-mPDMS was also increased. The half
life of the SA2 silicone decreased upon addition of the UV absorber, Norbloc, but
the decrease was not enough to offset the substantial increase in the half life of
the NVP. Comparing Comparative Example 2 (formulation containing DMA and Norbloc)
to Comparative Example 3 (formulation containing DMA without Norbloc), it can be seen
that the inclusion of Norbloc in a DMA-containing formulation slowed the reaction
rate for the crosslinker TEGDMA and more than doubled its half life. In the DMA/Norbloc-containing
formulation, this meant that the crosslinker had a reactivity rate much more similar
to the hydrophilic monomer and silicone-containing component. Even though the inclusion
of a UV absorber such as Norbloc slowed the reaction rate for TEGDMA, it was still
faster (4.92) than both the hydrophilic monomer (0.145) and silicone-containing component
(1.05).
[0169] Contact lenses were made from the Formulations of Examples 3-5 and Comparative Example
3 using the method described in Example 2. The properties of the lenses were measured
and are shown in Table 16, below.
Table 16
| Ex. # |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 2 |
58.4 (0.2) |
4 (0) |
44 (4) |
103 (11) |
220 (36) |
75 |
| 3 |
66.6 (0.1) |
24 (1) |
50 (3) |
63 (8) |
192 (76) |
79 |
| CE2 |
59.8(0.1) |
5(1) |
127(14) |
54 (7) |
227 (52) |
49 |
| CE3 |
58.1 (0.2) |
3 (1) |
132 (7) |
78(7) |
199 (39) |
49 |
| 4 |
67 (0.2) |
67(2) |
51 (3) |
64 (7) |
229 (97) |
82 |
| 5 |
65.5 (0.1) |
8 (1) |
68 (7) |
105 (9) |
242 (49) |
57 |
[0170] The lenses of Examples 2 through 5 show desirable haze and wettability, as well as
a balance of other desirable properties. Each of these Examples had ratios of the
slow-reacting hydrophilic monomer half life:silicone-containing component half life
greater than about 2. Comparative Examples 2 and 3 had half life ratios of below 2
(1.2 and 1.88 respectively). Thus, half life ratios greater than about 2, and greater
than about 3 are desirable to provide desirable wettability.
[0171] Comparing the modulii of Comparative Example 2 (54 psi, with Norbloc) and Comparative
Example 3 (78 psi without Norbloc) it can be seen that the change in the reactivity
rate for TEGDMA caused by the inclusion of Norbloc was sufficient to decrease crosslinking
in the network of the resulting polymer. Thus, in additional to changing the amount
of crosslinker, one can also choose a crosslinker with a different reactivity ratio
to achieve a desired polymer structure and modulus. The same behavior is also observed
comparing the SA2/NVP-containing formulations of Examples 4 and 5.
Examples 6 -7
[0172] Example 1 and 2 were repeated except the amount of initiator was increased to 0.5
and 0.75%, respectively and the amount of NVP was decreased. The kinetics of each
of the formulations was measured and calculated as described in Example 1, and lenses
were made as described in Example 2. The kinetics results are shown in Tables 17 through
19 and the lens properties are shown in Table 19a.
Table 17
| Example 6: 0.50% CGI 819 |
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| |
| NVP |
0.25 - 6 min |
0.956 |
-0.0502 |
0.1156 |
5.99 |
| HEMA |
0.25 - 4 min |
0.941 |
-0.3357 |
0.7731 |
0.90 |
| TEGDMA |
0.25 - 2 min |
0.997 |
-0.6348 |
1.4619 |
0.47 |
| Norbloc |
0.25 - 4 min |
0.996 |
-0.5534 |
1.2745 |
0.54 |
| CGI 819 |
0.25 - 4 min |
0.999 |
-0.4902 |
1.1289 |
0.61 |
| OH-mPDMS |
0.25 - 2 min |
0.994 |
-0.4720 |
1.0870 |
0.64 |
Table 18
| Example 7, 0.75% CGI 819 |
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 4 min |
0.995 |
-0.0511 |
0.1177 |
5.89 |
| HEMA |
0.25 - 4 min |
0.930 |
-0.3754 |
0.8645 |
0.80 |
| TEGDMA |
0.25 - 2 min |
0.976 |
-0.6392 |
1.4721 |
0.47 |
| Norblock |
0.25 - 4 min |
0.984 |
-0.9843 |
2.2668 |
0.31 |
| CGI 819 |
0.25 - 4 min |
0.998 |
-0.4357 |
1.0034 |
0.69 |
| OH-mPDMS |
0.25 - 4 min |
0.998 |
-0.3688 |
0.8493 |
0.82 |
Table 19
| Ex.# |
2 |
6 |
7 |
| CGI819 |
0.25 |
0.5 |
0.75 |
| NVP ½ life |
11.36 |
5.99 |
5.89 |
| Si ½ life |
1.17 |
0.64 |
0.82 |
| HP/Si |
9.7 |
9.4 |
7.2 |
| [µmol HP]/[µmol Si] @90% conversion |
55.25 |
56.05 |
56.40 |
Table 19a
| Ex. # |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 2 |
58.4 (0.2) |
4 (0) |
44 (4) |
102.9 (11.4) |
220.3 (36.2) |
74.7 |
| 6 |
62.4 (0) |
3 (0) |
45 (6) |
76.3 (6.7) |
202.9 (55.2) |
61.7 |
| 7 |
65.3 (0.2) |
4 (0) |
69 (11) |
58.5 (6.5) |
198.3 (49.8) |
78.1 |
[0173] Changing the initiator concentration from 0.25 (Ex. 2) to 0.5 (Ex. 6) had relatively
little effect on the half life ratio of slow-reacting hydrophilic monomer to silicone-containing
component in the formulations or the ratio of the concentrations of the slow-reacting
hydrophilic monomer and silicone-containing components at 90% conversion. Increasing
the initiator concentration to 0.75 wt% (Ex. 75) did measurably change the half life
ratio of slow-reacting hydrophilic monomer to silicone-containing component but had
a neglible effect on the ratio of the concentrations of the slow-reacting hydrophilic
monomer and silicone-containing components at 90% conversion. The lenses of Example
7 displayed acceptable properties including haze and advancing contact angle.
Examples 8 - 12
[0174] The level of BHT and initiator was varied as shown in Table 20. In Example 10 2 wt%
VINAL, was added to the formulation of Example 8.
Table 20
| Ex# |
8 |
9 |
10 |
11 |
12 |
| [BHT] ug/g |
1429 |
166 |
166 |
166 |
1429 |
| mPDMS 1000 |
15 |
15 |
15 |
15 |
15 |
| OH-mPDMS, n=4 |
25 |
25 |
25 |
25 |
25 |
| NVP |
50.5 |
50.5 |
50.38 |
50.25 |
48.5 |
| HEMA |
6.75 |
6.75 |
6.75 |
6.75 |
6.54 |
| VINAL |
0 |
0 |
0 |
0 |
2 |
| TEGDMA |
0.5 |
0.5 |
0.5 |
0.5 |
0.5 |
| Norbloc |
2 |
2 |
2 |
2 |
2 |
| CGI 819 |
0.25 |
0.25 |
0.37 |
0.5 |
0.25 |
[0175] The kinetics for the two formulations were measured and calculated as described in
Example 1, and contact lenses were made as described in Example 2. The kinetics for
the formulations are shown in Tables 21-26, and the lens properties are shown in Table
25.
Table 21: Example 8
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 8 min |
0.975 |
-0.0267 |
0.0615 |
11.27 |
| HEMA |
0.25 - 4 min |
0.993 |
-0.2044 |
0.4707 |
1.47 |
| TEGDMA |
0.25 - 2 min |
0.947 |
-0.3171 |
0.7303 |
0.95 |
| Norblock |
0.25 - 4 min |
0.999 |
-0.2441 |
0.5622 |
1.23 |
| CGI 819 |
0.25 - 4 min |
1.000 |
-0.5438 |
1.2524 |
0.55 |
| OH-mPDMS |
0.25 - 4 min |
0.997 |
-0.1885 |
0.4341 |
1.60 |
| mPDMS 1000 |
0.25 - 4 min |
0.997 |
-0.1515 |
0.3489 |
1.99 |
Table 22: Example 9
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 8 min |
0.989 |
-0.0294 |
0.0677 |
10.24 |
| HEMA |
0.25 - 4 min |
0.997 |
-0.2527 |
0.5820 |
1.19 |
| TEGDMA |
0.25 - 2 min |
0.989 |
-0.4923 |
1.1338 |
0.61 |
| Norblock |
0.25 - 4 min |
0.999 |
-0.3536 |
0.8143 |
0.85 |
| CGI 819 |
0.25 - 4 min |
1.000 |
-0.5228 |
1.2040 |
0.58 |
| OH-mPDMS |
0.25 - 4 min |
0.999 |
-0.2499 |
0.5755 |
1.20 |
| mPDMS 1000 |
0.25 - 2 min |
0.996 |
-0.1474 |
0.3395 |
2.04 |
Table 23: Example 10
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 8 min |
0.990 |
-0.0381 |
0.0877 |
7.90 |
| HEMA |
0.25 - 4 min |
0.985 |
-0.3395 |
0.7819 |
0.89 |
| TEGDMA |
0.25 - 4 min |
0.946 |
-0.3549 |
0.8173 |
0.85 |
| Norblock |
0.25 - 4 min |
0.980 |
-0.5042 |
1.1612 |
0.60 |
| CGI 819 |
0.25 - 4 min |
0.999 |
-0.4793 |
1.1038 |
0.63 |
| OH-mPDMS |
0.25 - 4 min |
0.989 |
-0.3222 |
0.7420 |
0.93 |
| mPDMS 1000 |
0.25 - 4 min |
0.993 |
-0.2765 |
0.6368 |
1.09 |
Table 24: Example 11
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 8 min |
0.887 |
-0.0611 |
0.1407 |
4.92 |
| HEMA |
0.25 - 4 min |
0.924 |
-0.4627 |
1.0656 |
0.65 |
| TEGDMA |
0.25 - 4 min |
0.852 |
-0.4986 |
1.1483 |
0.60 |
| Norblock |
0.25 - 4 min |
0.985 |
-0.6741 |
1.5525 |
0.45 |
| CGI 819 |
0.25 - 4 min |
1.000 |
-0.4326 |
0.99628 |
0.70 |
| OH-mPDMS |
0.25 - 4 min |
0.940 |
-0.4831 |
1.1126 |
0.62 |
| mPDMS 1000 |
0.25 - 4 min |
0.989 |
-0.4703 |
1.0831 |
0.64 |
Table 25: Example 12
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| VINAL |
0.25 - 18 min |
0.904 |
-0.0126 |
0.0290 |
23.88 |
| NVP |
0.25 - 8 min |
0.949 |
-0.0273 |
0.0629 |
11.02 |
| HEMA |
0.25 - 2 min |
0.979 |
-0.3082 |
0.7098 |
0.98 |
| TEGDMA |
0.25 - 2 min |
0.984 |
-0.4253 |
0.9795 |
0.71 |
| Norblock |
0.25 - 2 min |
0.975 |
-0.2924 |
0.6734 |
1.03 |
| CGI 819 |
0.25 - 4 min |
1.000 |
-0.4882 |
1.1243 |
0.62 |
| OH-mPDMS |
0.25 - 2 min |
0.971 |
-0.2819 |
0.6492 |
1.07 |
| mPDMS 1000 |
Not Measured |
Table 26
| Ex.# |
8 |
9 |
10 |
11 |
12 |
| [BHT] ug/g |
9324 |
901 |
901 |
901 |
9324 |
| [CGI819] |
0.25 |
0.25 |
0.37 |
0.5 |
0.25 |
| NVP ½ life |
11.27 |
10.24 |
7.90 |
4.92 |
11.02 |
| mPDMS ½ life |
1.99 |
2.04 |
1.09 |
0.64 |
** |
| OH-mPDMS ½ life |
1.60 |
1.02 |
0.93 |
0.62 |
1.07 |
| NVP/MPDMS |
5.7 |
5.0 |
7.3 |
7.7 |
** |
| NVP/OH-mPDMS |
7.0 |
8.5 |
8.5 |
7.9 |
10.3 |
| VINAL/HO-PDMS |
** |
** |
** |
** |
22.3 |
| [µmol NVP]/[µmol mPDMS] @90% conversion |
211.45 |
233.18 |
273.5 |
251.9 |
XX |
| [µmol NVP]/[µmol HO-mPDMS] @90% conversion |
94.71 |
83.6 |
92 |
99 |
68.57 |
** Not applicable
XX not measured. |
Table 27
| Ex. # |
8 |
9 |
10 |
11 |
12 |
| % H2O |
59.1 (0.1) |
60.0 (0.2) |
61.3(0.2) |
63.6(0.2) |
61.3 (0.2) |
| % Haze |
3 (1) |
5 (1) |
4 (1) |
5 (0) |
NT |
| DCA |
49 (2) |
47 (3) |
52 (4) |
56 (5) |
51(3) |
| Mod. (psi) |
92 (10) |
84 (10) |
65 (9) |
66 (7) |
84 (12) |
| Elong. (%) |
188 (67) |
194 (64) |
197 (25) |
163 (61) |
149(61) |
| Dk |
86.7 |
90.7 |
82.8 |
82.3 |
90.4 |
| Lipocalin (µg/lens) |
3.16 (0.6) |
3.37 (0.2) |
NT |
NT |
2.98 (0.3) |
| Total lipids (µg/lens) |
22.7 (2.9) |
23 (1.9) |
NT |
NT |
13.2 (1.9) |
| Lysozyme (µg/Lens) |
5.6 (0.9) |
NT |
NT |
NT |
39 (6.2) |
| Lysozyme Activity (%) |
68 (2.7) |
NT |
NT |
NT |
78.7 (2.5) |
| PQ1 Uptake (µg/mL) |
7.4 (0.4) |
NT |
NT |
NT |
7.1 (0.1) |
[0176] All the lenses of Examples 8-12 have half life ratios greater than about 5, and all
display desirably low advancing contact angles (less than 60°), very low haze (less
than 10) and desirable oxygen permeabilities greater than 80. The lenses of Examples
8-12 also have concentration ratios of the slow-reacting hydrophilic monomer to the
silicone-containing components at 90% conversion of greater than about 83. Comparing
Examples 8 and 9 shows that decreasing the inhibitor concentration from 1429 µg/g
to 166 µg/g reduces the modulus slightly, but has a negligible impact on the other
measured lens properties. Comparing Examples 9-11, decreases both the modulus and
the Dk and increases the water content of the resultant lenses, particularly comparing
Examples 9 and 11. This would suggest that the incorporation of the HO-PDMS is having
a larger effect on the Dk than the incorporation of the mPDMS, as the kinetic ratio
of NVP to HO-PDMS is trending in the same direction as the Dk for Examples 9-11.
Examples 13-15
[0177] The preparation described in Example 1 and kinetics evaluation described in Example
2 were repeated for the formulations listed in Table 28 below. Tables 29-30 show a
summary of the calculated kinetics data for Examples 13-14, and Table 31 shows the
ratios of slow-reacting hydrophilic monomer to the silicone-containing component.
Lens properties are shown in Table 32.
Table 29: Example 13
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| GMMA |
0.033 - 0.5 min |
0.849 |
-1.8339 |
4.2235 |
0.16 |
| TEGDMA |
0.033 - 0.5 min |
0.825 |
-1.9297 |
4.4441 |
0.16 |
| Norbloc |
0.033 - 0.5 min |
0.834 |
-1.8209 |
4.1935 |
0.17 |
| CGI 819 |
0.033 - 1 min |
0.980 |
-0.3888 |
0.8954 |
0.77 |
| SA2 |
0.083 - 0.75 min |
0.776 |
-0.8522 |
1.9626 |
0.35 |
Table 30: Example 14
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| EGVE |
0.25 - 6 min |
0.944 |
-0.0138 |
0.03178 |
21.81 |
| TEGDMA |
0.25 - 1 min |
0.974 |
-0.8791 |
2.02457 |
0.34 |
| Norbloc |
0.25 - 4 min |
0.990 |
-0.4128 |
0.95068 |
0.73 |
| CGI 819 |
0.25 - 4 min |
0.994 |
-0.3326 |
0.76598 |
0.90 |
| SA2 |
0.25 - 4 min |
0.994 |
-0.3630 |
0.83599 |
0.83 |
Table 31
| |
13 |
14 |
15 |
| HP |
GMMA |
GMMA |
EGVE |
| HP ½ life |
0.16 |
NC |
21.81 |
| SA2 ½ life |
0.35 |
NC |
0.83 |
| HP/SA2 |
0.46 |
NC |
26.3 |
| [µmol HP]/[µmol SA2] @90% conversion |
1.8 |
NC |
93.9 |
Table 32
| Ex. # |
13 |
14 |
15 |
| % H2O |
56.5 (0.1) |
60.7 (0.3) |
NT |
| % Haze |
89 (8) |
15 (1) |
NT |
| DCA |
131 (9) |
123 (7) |
NT |
| Mod. (psi) |
NT |
137 (19) |
NT |
| Elong. (%) |
NT |
147 (51) |
NT |
| Dk |
37.5 |
41.2 |
NT |
[0178] In Example 13, the hydrophilic component, GMMA, cures much faster than the silicone-containing
component, SA2, yielding a kinetic half life ratio of 0.45. Lenses made from the formulation
of Example 13 had an advancing contact angle of 131°, which were very unwettable and
a Dk of only 37.5. Example 13 shows that it is not enough for the kinetic rates of
the hydrophile and the silicone containing component to be different, at least one
hydrophile must be slower to get the desired properties described in the present invention.
Example 14 shows that the inclusion of a diluent in the reactive mixture improved
the haze without substantially changing the water content, advancing contact angle
or Dk. Example 15 showed a kinetic ratio of 26.3, however, lenses made from this formulation
were not fully cured within the 18 minute cure time and lens properties were not measured.
Examples 16-18 (Example 18 is a reference example)
[0179] The preparation and kinetics evaluation described in Examples 1 and 2 were repeated
for the formulations listed in Table 35 below. Tables 36- 38 show a summary of the
calculated kinetics data for Examples 16-18, and Table 39 shows the ratios of slow
hydrophilic component to the silicone component.
Table 35
| Component |
16 |
17 |
18 |
| mPDMS 1000 |
15.00 |
15.00 |
15.00 |
| OH-mPDMS, n=4 |
25.00 |
25.00 |
25.00 |
| VMA |
50.25 |
49.75 |
52.25 |
| HEMA |
6.75 |
6.75 |
6.75 |
| TEGDMA |
0.50 |
0.50 |
0.50 |
| Norbloc |
2.00 |
2.00 |
0.00 |
| CGI 819 |
0.50 |
1.00 |
0.50 |
Table 36: Example 16, 0.5% CGI 819
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| VMA |
0.25 - 6 min |
0.963 |
-0.0111 |
0.0256 |
27.11 |
| HEMA |
0.25 - 10 min |
0.954 |
-0.2126 |
0.4896 |
1.42 |
| TEGDMA |
0.25 - 10 min |
0.734 |
-0.0864 |
0.1990 |
3.48 |
| Norbloc |
0.25 - 6 min |
0.981 |
-0.3048 |
0.7020 |
0.99 |
| CGI 819 |
0.25 - 4 min |
0.996 |
-0.3056 |
0.7038 |
0.98 |
| OH-mPDMS |
0.25 - 10 min |
0.949 |
-0.1878 |
0.4325 |
1.60 |
| mPDMS 1000 |
0.25 - 4 min |
0.991 |
-0.1085 |
0.2499 |
2.77 |
Table 37: Example 17, 1% CGI 819
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| VMA |
0.25 - 6 min |
0.925 |
-0.0134 |
0.0309 |
22.46 |
| HEMA |
0.25 - 6 min |
0.999 |
-0.3642 |
0.8388 |
0.83 |
| TEGDMA |
0.25 - 4 min |
0.495 |
-0.0735 |
0.1693 |
4.09 |
| Norblock |
0.25 - 4 min |
0.998 |
-0.4342 |
1.0000 |
0.69 |
| CGI 819 |
0.25 - 4 min |
0.998 |
-0.3398 |
0.7826 |
0.89 |
| OH-mPDMS |
0.25 - 6 min |
0.998 |
-0.3185 |
0.7335 |
0.94 |
| mPDMS 1000 |
0.25 - 10 min |
0.944 |
-0.1860 |
0.4284 |
1.62 |
Table 38: Example 18, No Norbloc
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| VMA |
0.25 - 10 min |
0.852 |
-0.0247 |
0.0569 |
12.18 |
| HEMA |
0.25 - 8 min |
0.999 |
-0.2553 |
0.5880 |
1.18 |
| TEGDMA |
0.25 - 2 min |
0.998 |
-0.4201 |
0.9675 |
0.72 |
| CGI 819 |
0.25 - 2 min |
0.999 |
-0.3280 |
0.7554 |
0.92 |
| OH-mPDMS |
0.25 - 8 min |
0.999 |
-0.2252 |
0.5186 |
1.34 |
| mPDMS 1000 |
0.25 - 10 min |
0.989 |
-0.1637 |
0.3770 |
1.84 |
Table 39
| |
16 |
17 |
18 |
| [CGI] |
0.5 |
1 |
0.5 |
| [Norbloc] |
2 |
2 |
0 |
| VMA ½ life |
27.11 |
22.46 |
12.18 |
| mPDMS ½ life |
2.77 |
1.62 |
1.84 |
| HO-mPDMS ½ life |
1.6 |
0.94 |
1.34 |
| VMA/mPDMS |
9.8 |
13.9 |
6.6 |
| VMA/HO-mPDMS |
16.9 |
23.9 |
9.1 |
| [µmol VMA]/[µmol mPDMS] @90% conversion |
287.9 |
298.2 |
311.9 |
| [µmol VMA]/[µmol HOPDMS] @90% conversion |
110.2 |
112.1 |
116.4 |
Table 40
| Ex# |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 16 |
66.0 (0.2) |
25 (1) |
NT |
NT |
NT |
103.9 |
| 17 |
77.9 (0.2) |
NT |
64 (10) |
19.0 (2.9) |
161.3 (57.8) |
|
| 18 |
84.0 (0.1) |
NT |
NT |
NT |
NT |
119.6 |
[0180] The formulations of Examples 16-18 all made very wettable contact lenses. Examples
16 and 18 displayed Dk greater than 100 and water contents greater than 60%. All lenses
felt flimsy upon handling, which is evidenced by the modulus of 19 for Example 17.
The inclusion of Norbloc in the VMA systems substantially (>300%,) slowed the kinetic
rate of the crosslinker, TEGDMA (from 0.967 for Example 18, without Norbloc to 0.199
for Example 16 with Norbloc). The kinetic rate of the crosslinker in Example 18 (no
UV absorber) was faster than the silicone components but slower than the silicones
in Example 16 (UV absorber).
[0181] Comparing Examples 16 and 17, increasing the amount of intiator in the formulation
provided a significant increase in the kinetic ratios for both HO-PDMS and mPDMS.
Comparing Example 16 (UV absorber) to Example 18 (no UV absorber), shows that the
inclusion of Norbloc slows the kinetic rate of the VMA by more 100%, and decreases
the kinetic half life. The influence on the kinetics of the silicone components were
not nearly as substantially impacted.
[0182] The properties of the lenses can be improved by improving the efficiency in the incorporation
of the slow components. In addition to optimizing the level of the initiator and UV
absorber and cure conditions (cure intensity, cure temperature and oxygen level),
the concentration and chemistry of the crosslinker(s) can significantly affect the
overall cure efficiency. Crosslinkers with two or more functional groups in which
at least one group is fast curing or a mixture of crosslinkers having varying cure
rates can improve the cure efficiency. Thus, crosslinkers with at least one functional
group (e.g. vinyl, allyl; HEMAVc) which is slow curing compared to the silicone components
may be used as the sole crosslinker or in a mixture with at least one additional crosslinker
can improve the efficiency in the incorporation of the slow curing hydrophile. Fast
curing crosslinkers with at least two reactive groups in which at least two of the
reactive groups are fast curing (e.g. acryloxy; acPDMS) can improve the efficiency
in the cure of the crosslinkers and silicones.
Comparative Examples 4-6
[0183] Comparative Examples 2 and 3 were repeated except that the formulations were changed
to add a high molecular weight wetting agent PVP, as shown in Table 41. The cure intensity
was 4-5 mW/cm
2. The preparation and kinetics evaluation described in Comparative Examples 2 and
3 were repeated. Tables 42-44 show a summary of the calculated kinetics data for Comparative
Examples 4-6. Table 45 shows the ratios of slow hydrophilic component to the silicone
component and Table 46 shows the lenses properties.
Table 41
| Component |
CE2 |
CE3 |
CE4 |
CE5 |
CE6 |
| OH-mPDMS, n=4 |
40.00 |
40.00 |
40.00 |
40.00 |
40.00 |
| DMA |
50.50 |
50.50 |
44.50 |
44.50 |
42.50 |
| HEMA |
6.75 |
8.75 |
8.75 |
6.75 |
8.75 |
| TEGDMA |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
| Norbloc |
2.00 |
0.00 |
0.00 |
2.00 |
2.00 |
| PVP K90 |
0.00 |
0.00 |
6.00 |
6.00 |
6.00 |
| CGI 819 |
0.25 |
0.25 |
0.25 |
0.25 |
0.25 |
Table 42: Comparative Example 4
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| DMA |
0.25 - 4 min |
0.915 |
-0.4257 |
0.9804 |
0.71 |
| HEMA |
0.25 - 4 min |
0.876 |
-0.4703 |
1.0831 |
0.64 |
| TEGDMA |
0.25 - 2 min |
0.962 |
-0.8083 |
1.8615 |
0.37 |
| CGI 819 |
0.25 - 1 min |
0.998 |
-0.5913 |
1.3618 |
0.51 |
| OH-mPDMS |
0.25 - 2 min |
0.975 |
-0.6646 |
1.5306 |
0.45 |
Table 43: Comparative Example 5
| Component |
Time Points |
R2 |
Slope |
k (min1) |
Half-life (t1/2), min |
| DMA |
0.25 - 4 min |
0.894 |
-0.3113 |
0.7169 |
0.97 |
| HEMA |
0.25 - 2 min |
0.744 |
-0.5696 |
1.3118 |
0.53 |
| TEGDMA |
0.25 - 1 min |
0.988 |
-1.4805 |
3.4096 |
0.20 |
| Norbloc |
0.25 - 1 min |
0.947 |
-1.1100 |
2.5563 |
0.27 |
| CGI 819 |
0.25 - 2 min |
0.958 |
-0.4512 |
1.0391 |
0.67 |
| OH-mPDMS |
0.25 - 2 min |
0.635 |
-0.4243 |
0.9771 |
0.71 |
Table 44: Comparative Example 6
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| DMA |
0.25 - 1; 6 min |
0.961 |
-0.2858 |
0.6582 |
1.05 |
| HEMA |
0.25 - 2 min |
0.775 |
-0.5679 |
1.3079 |
0.53 |
| TEGDMA |
0.25 - 0.75 min |
1.000 |
-0.7276 |
1.6757 |
0.41 |
| Norbloc |
0.25 - 2 min |
0.719 |
-0.4515 |
1.0398 |
0.67 |
| CGI 819 |
0.25 - 1min |
0.988 |
-0.4852 |
1.1174 |
0.62 |
| OH-mPDMS |
0.25 - 2 min |
0.659 |
-0.3786 |
0.8719 |
0.79 |
Table 45
| |
CE2 |
CE3 |
CE4 |
CE5 |
CE6 |
| DMA ½ life |
2.01 |
1.73 |
0.71 |
0.97 |
1.05 |
| HO-mPDMS ½ life |
1.66 |
0.92 |
0.45 |
0.71 |
0.79 |
| DMA½ life /HO-mPDMS½ life |
1.2 |
1.9 |
1.6 |
1.4 |
1.3 |
| [µmol DMA]/[µmol HOPDMS] @90% conversion of HOPDMS |
9.3 |
9 |
10.9 |
7.0 |
3.6 |
Table 46
| Ex# |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| CE2 |
59.8 (0.1) |
5 (1) |
127 (14) |
54.1 (7.4) |
227.3 (52.3) |
48.5 |
| CE3 |
58.1 (0.2) |
3 (1) |
132 (7) |
78.1 (6.9) |
198.6 (39.4) |
49.2 |
| CE4 |
63.0 (0.2) |
10 (0) |
107 (6) |
42.8 (3.8) |
271.0 (61.0) |
53.4 |
| CE5 |
62.0 (0.3) |
547 (1) |
121 (7) |
47.3 (4.8) |
274.1 (71.3) |
56.5 |
| CE6 |
58.7 (0.3) |
7 (0) |
99 (7) |
74.6 (6.3) |
242.3 (35.6) |
49.8 |
[0184] All of the formulations other than Comparative Example 5 displayed very low haze
values. All of the kinetic rate ratios are well below 3. Comparative Examples 2 and
3 contain no PVP, and based upon the present invention it was expected that they would
display poor in vitro wettability as measured by advancing contact angle. Comparative
Examples 4-6 contain 6 wt% PVP, a wetting agent known to be effective at improving
wettability. However, the advancing contact angles for Comparative Examples 4-6 are
not substantially better than those for Comparative Examples 2-3.
Comparative Example 7
[0185] Comparative Example 6 was repeated at an intensity of 0.9 mW/cm
2. The kinetics calculations are shown in Table 47. The half-life ratio of DMA:OH-mPDMS
was 1.3 and the advancing contact angle was 114.
Table 47 Comparative Example 7, 0.9 mW/cm2
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life(t1/2), min |
| DMA |
0.25 - 4 min |
0.914 |
-0.1206 |
0.2777 |
2.50 |
| HEMA |
0.25 - 2 min |
0.987 |
-0.1742 |
0.4012 |
1.73 |
| TEGDMA |
0.25 - 6 min |
0.996 |
-0.2155 |
0.4963 |
1.40 |
| Norbloc |
0.25 - 4 min |
0.984 |
-0.1388 |
0.3196 |
2.17 |
| CGI 819 |
0.25 - 6 min |
0.868 |
-0.0279 |
0.0643 |
10.79 |
| OH-mPDMS |
0.25 - 6 min |
0.976 |
-0.1567 |
0.3609 |
1.92 |
Examples 19-22 (reference examples)
[0186] The effect of thermal initiation (Examples 21-22) and photoinitiation (Examples 19-20)
on the ratio of the hydrophilic monomer to the hydrophobic monomers and the cure time
was evaluated on the formulations shown in Table 48. The kinetics for Examples 19
and 20 were evaluated as in Example 1 and lenses of Examples 21 and 22 were made and
evaluated as in Example 2. The kinetics for Examples 21 and 22 were evaluated as in
Example 1, except the light source was turned off and samples were generated at 50
- 55 °C, at the following time points: 0 hour to 5.00 hours in 0.25 hour increments;
and from 5.00 hours to 8.00 hours in 0.50 hour increments. The kinetics are shown
in Tables 49-52, and the lens properties are shown in Table 53. The lenses of Examples
19 and 20 were cured at a temperature of about 55°C for 24 hours.
Table 49: Example 19
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
0.25 - 8 min |
0.748 |
-0.0336 |
0.0774 |
8.96 |
| HEMA |
0.25 - 6 min |
0.999 |
-0.1519 |
0.3498 |
1.98 |
| TEGDMA |
0.25 - 8 min |
0.988 |
-0.1942 |
0.4472 |
1.55 |
| CGI 819 |
0.25 - 1 min |
0.997 |
-0.3746 |
0.8627 |
0.80 |
| TRIS |
0.25 - 1 min |
0.979 |
-0.0714 |
0.1644 |
4.21 |
| mPDMS 1000 |
0.25 - 4 min |
0.998 |
-0.0769 |
0.1771 |
3.91 |
Table 50: Example 20
| Component |
Time Points |
R2 |
Slope |
k (min-1) |
Half-life (t1/2), min |
| NVP |
Calculated Based on Measured % Residuals |
*0.1298 |
5.34 |
| HEMA |
0.25 - 2 min |
0.996 |
-0.2446 |
0.5633 |
1.23 |
| TEGDMA |
0.25 - 4 min |
0.998 |
-0.4205 |
0.9684 |
0.72 |
| CGI 819 |
0.25 - 1 min |
0.999 |
-0.3117 |
0.7179 |
0.97 |
| TRIS |
0.25 - 2 min |
0.995 |
-0.1294 |
0.2980 |
2.33 |
| mPDMS 1000 |
0.25 - 2 min |
0.992 |
-0.1327 |
0.3056 |
2.27 |
| |
|
*k = 0.693/5.34 |
|
|
|
Table 51: Example 21
| Component |
Time Points (hr) |
R2 |
Slope |
k (hr-1) |
Half-life (t1/2), hr |
| NVP |
0.25 - 4 |
0.759 |
-0.0654 |
0.1506 |
4.60 |
| HEMA |
0.25 - 1.75 |
0.891 |
-0.2137 |
0.4922 |
1.41 |
| TEGDMA |
0.25 - 1.75 |
0.926 |
-0.3307 |
0.7616 |
0.91 |
| TRIS |
0.25 - 2 |
0.743 |
-0.1607 |
0.3701 |
1.87 |
| mPDMS 1000 |
0.25 - 2 |
0.741 |
-0.1716 |
0.3952 |
1.75 |
Table 52: Example 22
| Component |
Time Points (hr) |
R2 |
Slope |
k (hr-1) |
Half-life (t1/2), hr |
| NVP |
0.25 - 1.25, 1.75 - 2.00, 3.00 |
0.867 |
-0.0867 |
0.1997 |
3.47 |
| HEMA |
0.25 - 0.75 |
0.893 |
-0.2668 |
0.6144 |
1.13 |
| TEGDMA |
0.25 - 0.75 |
0.908 |
-0.4034 |
0.9290 |
0.75 |
| TRIS |
0.25 - 1.00 |
0.747 |
-0.2225 |
0.5124 |
1.35 |
| mPDMS 1000 |
0.25 - 1.00 |
0.704 |
-0.2319 |
0.5341 |
1.30 |
Table 53
| Ex. # |
19 |
20 |
21 |
22 |
| NVP ½ life |
8.96 |
5.34 |
4.6 |
3.47 |
| TRIS ½ life |
4.21 |
2.33 |
1.87 |
1.35 |
| mPDMS ½ life |
3.91 |
2.27 |
1.75 |
1.3 |
| NVP/TRIS |
2.13 |
2.29 |
2.46 |
2.57 |
| NVP/mPDMS |
2.29 |
2.35 |
2.63 |
2.67 |
| [µmol NVP]/[µmol TRIS] @90% conversion |
37.8 |
41.2 |
61.6 |
58.9 |
| [µmol NVP]/[µmol mPDMS] @90% conversion mPDMS |
115.6 |
127.8 |
200.9 |
135.7 |
Table 54
| Ex.# |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 19 |
56.7 (0.1) |
6 (0) |
41 (4) |
149.8 (9.9) |
107.9 (18.3) |
74.9 |
| 20 |
60.8 (0.1) |
9 (1) |
45 (6) |
102.2 (11.5) |
83.4 (18.0) |
77.2 |
| 21 |
51.9 (0.1) |
5 (1) |
44 (3) |
218.0 (4.3) |
111.2 (16.4) |
77.4 |
| 22 |
53.4 (0.1) |
6 (1) |
34 (6) |
216.5 (12.5) |
125.0 (19.7) |
59 |
[0187] Examples 19 and 20 used visible light initiation, and Examples 21-22 used thermal
initiation. All examples displayed desirable water content, haze and advancing contact
angles. However, Examples 21 and 22 displayed undesirably high modulii (greater than
200 psi) and also undesirably long cure times 24 hours (compared with the cure times
of the formulations of the present invention (less than 30 minutes).
[0188] Figures 4-7 show the importance of the kinetic half life ratios and the conversion
ratios on the resulting advancing contact angle and Dk of the lenses.
[0189] Figure 4 is a graph of the conversion mole ratio vs. advancing contact angle of the
contact lenses made in Examples 1, 3-13, 17, 19-23 and Comparative Examples 1, 3,
4 and 6-7, and Figure 5 is a graph of the half life ratio vs. advancing contact angle
for the same contact lenses. Figure 6 is a graph of the half life ratio vs. advancing
contact angle, but with the axis for the half life ratios expanded to show the area
up 3. Looking at Figures 4 and 6 it can be seen that conversion ratios of at least
20, and kinetic half-life ratios of at least about 2 surprisingly form lenses with
exceptional wettability. Figure 7 also shows that at a kinetic half life ratio of
about 2 there is a surprising discontinuity in the Dk of the resulting lenses, with
contact lenses formed from reaction mixtures where kinetic half life ratio of the
slow-reacting hydrophilic monomer: silicone-containing was 2 or greater had a surprisingly
increased Dk compared to formulations where the kinetic half life ratio of the slow-reacting
hydrophilic monomer: silicone-containing was less than 2.
Example 23 and Comparative Examples 8-12
[0190] A reaction mixture was formed by mixing the components listed in Table 55 and degassed
by applying vacuum at ambient temperature for about 7 - 10 minutes. The amounts of
the reaction components are listed as the weight % of reaction components, without
diluent. The reaction mixture (75 µL) was dosed, cured, and the lenses demolded, released,
packaged and autoclaved using the process of Example 1, with a cure time of 20 minutes.
[0191] Lens properties are shown in Table 56.
Table 55
| Component |
Ex. 23 |
CE8 |
CE9 |
CE10 |
CE11 |
CE12 |
| mPDMS 1000 |
16.50 |
16.50 |
16.50 |
16.50 |
16.50 |
16.50 |
| OH-mPDMS, n=4 |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
| NVP |
46.65 |
44.15 |
41.65 |
39.15 |
35.15 |
23.35 |
| HEMA |
6.75 |
6.75 |
6.75 |
6.75 |
6.75 |
6.75 |
| DMA |
0.00 |
2.50 |
5.00 |
7.50 |
11.50 |
23.30 |
| EGDMA |
0.35 |
0.35 |
0.35 |
0.35 |
0.35 |
0.35 |
| Norbloc |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
| CGI 819 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
| Diluent |
10.00 |
10.00 |
10.00 |
10.00 |
10.00 |
10.00 |
| TAA |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
Table 56
| Ex # |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| Ex 23 |
61 (0) |
6 (1) |
48 (6) |
75 (10) |
145 (57) |
92 |
| CE8 |
63 (0) |
7 (1) |
79 (9) |
57 (6) |
171 (36) |
89 |
| CE9 |
63 (0) |
9 (1) |
107 (3) |
52 (4) |
164 (53) |
89 |
| CE10 |
63 (0) |
9 (1) |
110 (4) |
46(6) |
162 (45) |
89 |
| CE11 |
60 (0) |
6 (1) |
119 (15) |
53 (6) |
184 (56) |
85 |
| CE12 |
56 (0) |
4 (0) |
114 (13) |
66 (6) |
195 (44) |
72 |
[0192] DMA is a hydrophilic component with intermediate reaction kinetics. It can be seen
from the data in Table 56, that amounts of DMA as small as 2.5 wt% (Comparative Example
8), dramatically decrease the modulus, but increase the advancing contact angle of
the resulting contact lenses. Depending upon the other properties of the lens, an
advancing contact angle of about 80°, as shown by Comparative Example 8, may be acceptable.
The Dk of the lenses also decreased as the amount of DMA increased, even though the
amount of silicone containing components remained constant. The kinetics for Examples
23, and Comparative Examples 8 and 9 are shown below in Tables 57-59, below. The kinetic
data was collected and calculated as described above, except that all time points
were measured in seconds.
Table 57
| Ex. 23 |
|
|
|
|
|
| Component |
Time Points |
R2 |
Slope |
k (s-1) |
Half-life (t1/2), s |
Half-life (t1/2), min |
| NVP |
5 - 600 s |
0.978 |
-0.0007 |
0.00161 |
429.87 |
7.16 |
| HEMA |
5 - 120 s |
0.999 |
-0.0068 |
0.01566 |
44.25 |
0.74 |
| EGDMA |
5 - 120 s |
0.994 |
-0.0120 |
0.02764 |
25.08 |
0.42 |
| Norbloc |
5 - 120 s |
0.995 |
-0.0071 |
0.01635 |
42.38 |
0.71 |
| CGI 819 |
5 - 240 s |
0.999 |
-0.0076 |
0.01750 |
39.59 |
0.66 |
| OH-mPDMS |
5 - 120 s |
0.996 |
-0.0060 |
0.01382 |
50.15 |
0.84 |
| mPDMS 1000 |
5 - 120 s |
0.994 |
-0.0038 |
0.00875 |
79.19 |
1.32 |
Table 58
| CE 8 |
|
|
|
|
|
| Component |
Time Points |
R2 |
Slope |
k (s-1) |
Half-life (t1/2), s |
Half-life (t1/2), min |
| DMA |
5 - 60 s |
0.978 |
-0.0032 |
0.00737 |
94.03 |
1.57 |
| NVP |
5 - 360 s |
0.992 |
-0.0008 |
0.00184 |
376.14 |
6.27 |
| HEMA |
5 - 60 s |
0.986 |
-0.0064 |
0.01474 |
47.02 |
0.78 |
| EGDMA |
5 - 60 s |
0.987 |
-0.0126 |
0.02902 |
23.88 |
0.40 |
| Norbloc |
5 - 60 s |
0.996 |
-0.0061 |
0.01405 |
49.33 |
0.82 |
| CGI 819 |
5 - 120 s |
0.995 |
-0.0068 |
0.01566 |
44.25 |
0.74 |
| OH-mPDMS |
5 - 60 s |
0.995 |
-0.0055 |
0.01267 |
54.71 |
0.91 |
| mPDMS 1000 |
5 - 60 s |
0.983 |
-0.0034 |
0.00783 |
88.50 |
1.48 |
Table 59
| CE 9 |
|
|
|
|
|
| Component |
Time Points |
R2 |
Slope |
k (s-1) |
Half-life (t1/2), s |
Half-life (t1/2), min |
| DMA |
5 - 60 s |
0.984 |
-0.0034 |
0.00783 |
88.50 |
1.48 |
| NVP |
5 - 360 s |
0.995 |
-0.0009 |
0.00207 |
334.35 |
5.57 |
| HEMA |
5 - 120 s |
0.996 |
-0.0070 |
0.01612 |
42.99 |
0.72 |
| EGDMA |
5 - 60 s |
0.988 |
-0.0126 |
0.02902 |
23.88 |
0.40 |
| Norbloc |
5 - 60 s |
0.994 |
-0.0061 |
0.01405 |
49.33 |
0.82 |
| CGI 819 |
5 - 120 s |
0.996 |
-0.0072 |
0.01658 |
41.79 |
0.70 |
| OH-mPDMS |
5 - 60 s |
0.99/8 |
-0.0054 |
0.01244 |
55.72 |
0.93 |
| mPDMS 1000 |
5 - 60 s |
0.982 |
-0.0034 |
0.00783 |
88.50 |
1.48 |
[0193] Comparing the kinetic data from Tables 57-59, it can be seen that as DMA is added
to the formulations in increasing amounts the kinetic half life of NVP decreases from
7.16 in Example 23 to 5.57 in Comparative Example 9. The ratio of the kinetic half
life to the silicone monomer HO-PMDS also decreases.
Examples 24-26, and Comparative Example 13
[0194] Lenses were made using the formulations listed in Table 60,
[0195] Each reaction mixture was formed by mixing the components listed in Table 60 and
degassed by applying vacuum at ambient temperature for about 25 minutes. The reaction
mixture (75 µL) was then dosed at room temperature and <0.1% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold to produce 8 BC/FC assemblies in a pallet. Eight pallets
were assembled and moved into the cure compartment (Compartment 2, Figure 2). Pallets
were placed on a mirrored surface and a quartz plate (0.50 mm thick) was placed over
each pallet. The lenses were cured for 20 minutes, an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65 °C.
[0196] The molds were mechanically separated demolded (lenses remained in FC). The lenses
were dry released by pressing on the back of the front curve. Lenses were extracted
in DI water and equilibrated in borate buffered packing solution in lens vials and
sterilized at 122°C for 30 minutes.
[0197] The properties of the lenses were measured and are shown in Table 61, below.
Table 60
| Component |
Ex 24 |
Ex 25 |
Ex. 26 |
CE 13 |
| mPDMS 1000 |
16.50 |
16.50 |
16.50 |
16.50 |
| OH-mPDMS, n=4 |
27.50 |
27.50 |
27.50 |
27.50 |
| NVP |
46.55 |
46.05 |
45.55 |
44.05 |
| HEMA |
6.75 |
6.75 |
6.75 |
6.75 |
| DMA |
0.00 |
0.50 |
1.00 |
2.50 |
| EGDMA |
0.45 |
0.45 |
0.35 |
0.45 |
| Norbloc |
1.75 |
1.75 |
1.75 |
1.75 |
| CGI 819 |
0.50 |
0.50 |
0.50 |
0.50 |
Table 61
| Lens |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| Ex 24 |
54 (0) |
9 (0) |
50 (4) |
111 (12) |
148 (39) |
98 |
| Ex 25 |
54 (0) |
11 (1) |
58 (9) |
117 (8) |
167 (36) |
97 |
| Ex 26 |
55 (0) |
10 (1) |
64 (4) |
122 (9) |
170 (27) |
97 |
| CE 13 |
54 (0) |
10 (0) |
93 (11) |
100 (7) |
146 (31) |
100 |
[0198] Examples 24-26 show that small amounts of non-hydroxyl containing hydrophilic monomers,
which are not slow reacting hydrophilic monomers may be incorporated into the formulations
of the present invention without losing wettablity. Also, comparing Comparative Example
13, with Comparative Example 8 (both had 2.5 wt% DMA), it can be seen that where a
formulation cured without diluents displays undesirable properties (Comparative Example
13, DCA of 93°), including a small amount of diluent may reduce the advancing contact
angle (Comparative Example 8, DCA of 79° and 10% t-amyl alcohol as a diluent).
[0199] Residual NVP in the reaction mixture was analyzed as function of cure time With the
degassed reaction mixtures in Examples 24 - 26 and CE13, cure studies were conducted
as follows. For each reaction mixture (75 µL) was dosed at room temperature and <0.1%
O
2, into thermoplastic contact lens molds (2 pallets containing 8 assemblies each, FC
- Zeonor, BC Polypropylene) which had been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold and the 2 pallets were moved into Compartment 2 and placed
a mirrored surface. A quartz plate (0.50 mm thick) was placed over each pallet and
the assembly was cured for 5 minutes at an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65 °C.
[0200] The molds were mechanically separated and using metallic tweezers and spatula, about
five lenses were removed from the molds and accurately weighed into a glass scintillation
vial. Using a calibrated Eppendorf pipet, 5 mL methanol was added to the vial. Samples
were prepared in duplicate.
[0201] The cure and sample preparation procedures were repeated to generate duplicate samples
at the following cure times (minutes): 10, 15 and 20. Cured polymers were extracted
in methanol overnight by gently shaking at room temperature. Analysis of NVP in the
cured samples was accomplished by HPLC following the method described earlier.
[0202] The concentration of NVP in each sample, expressed as a percent of the sample weight
as follows:

[0203] The results are shown in Table 62.
Table 62a
| Residual NVP, Wt% of Cured Polymer (Stdev.) |
| DMA (Wt. %) |
0.0% |
0.5% |
1.0% |
2.5% |
| Cure Time (mins) |
Ex. 24 |
Ex. 25 |
Ex. 26 |
CE 13 |
| 5 |
14.58 (1.71) |
11.12 (0.72) |
13.41 (0.20) |
8.14 (0.05) |
| 10 |
1.92 (0.02) |
1.91 (0.07) |
2.07 (0.09) |
1.71 (0.06) |
| 15 |
1.12 (0.01) |
1.12 (0.02) |
1.13 (0.01) |
0.97 (0.01) |
| 20 |
0.80 (0.01) |
0.77 (0.00) |
0.82 (0.02) |
0.70 (0.00) |
Table 62b
| Residual NVP, Expressed as % of Initial NVP in Reactive Mixture |
| DMA (Wt. %) |
0.0% |
0.5% |
1.0% |
2.5% |
| Cure Time (mins) |
Ex. 24 |
Ex. 25 |
Ex. 26 |
CE 13 |
| 5 |
31.32 |
24.15 |
29.44 |
18.48 |
| 10 |
4.12 |
4.15 |
4.54 |
3.88 |
| 15 |
2.41 |
2.43 |
2.57 |
2.20 |
| 20 |
1.72 |
1.67 |
1.80 |
1.59 |
[0204] From the data in Tables 62a and b, it can be seen that as the concentration of DMA
increases, the amount of NVP incorporated into the lenses across all the times measured
increases. The difference is particularly noticeable at 5 minutes, which indicates
that more NVP is polymerizing with the silicone monomers when DMA is included in amounts
of 2.5 wt% or more.
Examples 27-33 (reference examples)
[0205] A series of lens formulations were formed from the following reactive components:
38.5 wt% mPDMSp
NVP
hydroxyalkyl methacrylate, shown in Table 63
1 wt % TEGDMA
0.25 CGI 819
[0206] The amount of hydroxylalkyl (meth)acrylate and NVP were varied to provide molar ratios
of the hydroxylalkyl (meth)acrylate:NVP of about 0.2. GMMA has two hydroxyl groups.
Accordingly, formulations having two different concentrations of GMMA were prepared,
Example 32 (13.23 wt% GMMA, 0.408 ratio, counting both hydroxyls) and Example 33 (6.62
wt % GMMA, 0.204, counting two hydroxyl).
[0207] The reactive components were mixed with a diluent (50% TAA/50% DA) in a ratio of
80 wt% reactive components: 20 wt% diluent. Examples 31 and 32 produce hazy reaction
mixtures which were not cured into lenses. Examples 27-30 and 33 produced clear reaction
mixtures which were cast into lenses using the following the procedure. The reaction
mixture was degassed by applying vacuum at ambient temperature for about 17(±3) minutes.
The reaction mixture was then dosed into thermoplastic contact lens molds (front curves
made from Zeonor, and back curves from polypropylene), The BC was placed on the FC
mold to produce 8 BC/FC assemblies in a pallet. Pallets were placed on a mirrored
surface and a quartz plate (12.50 mm x 6.25 mm x 0.50 mm) was placed over each pallet.
The lenses were cured for about 15 minutes at 45°C, under a nitrogen atmosphere, using
Philips TL 20W/03T fluorescent bulbs and 4-5 mW/cm
2.
[0208] Lenses were released in 50/50 IPA/water, extracted in 70/30 IPA/water and subsequently
equilibrated in de-ionized water. Lenses were transferred into vials containing borate
buffered saline for at least 24 hours and then autoclaved at 122°C for 30 minutes.
Lens properties were measured and are reported in Table 63, below.
Table 63
| Example |
27 |
28 |
29 |
30 |
31 |
32 |
33 |
| Component |
HEMA |
HPMA |
HBMA |
DMHEMA |
HEAA |
GMMA |
GMMA |
| [NVP] wt % |
47.5 |
47.5 |
45.18 |
45.18 |
48.75 |
45.01 |
51.63 |
| [HOMA] wt% |
10.75 |
10.75 |
13.07 |
13.07 |
9.50 |
13.23 |
6.62 |
| HOMA:NVP (molar) |
0.193 |
0.174 |
0.203 |
0.203 |
0.188 |
0.408 |
0.204 |
| HO:Si |
0.19 |
0.19 |
0.19 |
0.19 |
0.19 |
0.38 |
0.19 |
| % H2O |
59.1 (0) |
58.9 (0.1) |
54.5 |
60.4 |
NT* |
NT |
62.6 |
| % Haze |
8 (0) |
16 (0) |
8 |
15 |
NT* |
NT* |
12 |
| DCA |
60 (7) |
63 (5) |
46 |
70 |
NT* |
NT* |
49 |
| MOD (psi) |
79.9 (1.9) |
73.4 (1.4) |
120.5 |
68.7 |
NT* |
NT* |
70.4 |
| Elong (%) |
196.2 (24.6) |
230.1 (1.8) |
179.3 |
206.5 |
NT* |
NT* |
203.5 |
| Dk |
89.1 |
93.4 |
93.4 |
90 |
NT* |
NT* |
85.3 |
[0209] Comparing Examples 32 and 33, it can be seen that when the molar amount of GMMA was
adjusted to account for both hydroxyls, clear lenses were formed. It is believed that
Example 20, which included HEAA as the hydroxyalkyl (meth)acrylate, did not provide
wettable lenses because the HEAA contains two polar groups, the amide and hydroxyl
groups, making the HEAA more polar than the other hydroxylalkyl (meth)acrylates used
in Examples 27-30 and 32-33. It is believed that the increased polarity of HEAA caused
compatibility issues with the mPDMS. However, HEAA has the potential to work with
more polar silicones, such as SiMAA, OH-mPDMS, N-(2,3-dihydroxypropane)-N'-(propyl
tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide. Thus, a variety of hydroxylalkyl
(meth)acrylate compounds can be used to form the hydrogels of the present invention.
Examples 34-41
[0210] Additional reaction mixtures were made varying the diluents system used and the siloxane
components as shown in Tables 64 and 65, below. All mixtures were formed using 80wt%
reactive components and 20wt% diluents. The lenses were molded, cured, processed and
sterilized according to the procedure described in Example 27, above. The lens properties
were measured and are shown in Tables 64 and 65.
Table 64
| |
Ex 34 |
Ex 35 |
Ex 36 |
Ex 37 |
| mPDMS |
20 |
20 |
20 |
20 |
| TRIS |
18.5 |
18.5 |
18.5 |
18.5 |
| NVP |
47.5 |
47.5 |
47.5 |
47.5 |
| HEMA |
10.75 |
10.75 |
10.75 |
10.75 |
| TEGDMA |
1 |
1 |
1 |
1 |
| Norbloc |
2 |
2 |
2 |
2 |
| CGI819 |
0.25 |
0.25 |
0.25 |
0.25 |
| Diluent |
1:1 EtOAc: EtOH |
TAA |
D3O |
1:1 TAA:DA |
| EWC |
46.0 ± 1.6% |
55.5 ± 0.1% |
58.9 ± 0.1% |
57.4 ± 0.1% |
| Haze |
50 ± 19 |
10 ± 2 |
12 ± 1 |
7 ± 0 |
| DCA |
NT |
NT |
66 ± 4° |
69 ± 6° |
| Modulus |
100 ± 13 psi |
83 ± 9 psi |
80 ± 7 psi |
88 ± 6 psi |
| Elongation |
305 ± 105% |
330 ± 49% |
307 ± 39% |
285 ± 73% |
| Dk |
NT |
80 |
64 |
75 |
Table 65
| |
Ex 38** |
Ex 39 |
Ex 40** |
Ex 41 |
| mPDMS |
38.5 |
38.5 |
38.5 |
38.5 |
| NVP |
47.5 |
47.5 |
47.5 |
47.5 |
| HEMA |
10.75 |
10.75 |
10.75 |
10.75 |
| TEGDMA |
1 |
1 |
1 |
1 |
| Norbloc |
2 |
2 |
2 |
2 |
| CGI819 |
0.25 |
0.25 |
0.25 |
0.25 |
| diluent |
1:1 EtOAc:EtOH |
TAA |
D30 |
1:1 TAA:DA |
| EWC |
** |
56.3 ± 0.2% |
** |
59 ± 0.1% |
| Haze |
** |
8 ± 0 |
** |
9 ± 1 |
| DCA |
** |
74 ± 2° |
** |
54 ± 3° |
| Modulus |
** |
62 ± 9 psi |
** |
70 ± 5 psi |
| %Elongation |
** |
252 ± 63% |
** |
245 ± 62% |
| Dk |
** |
107 |
** |
91 |
The blends of Examples 38 and 40 were immiscible and were not cast into lenses. These
Examples show that a wide range of diluents may be used to form the lenses of the
present invention. These examples also show that secondary alcohols provide formulations
with a desirable balance of properties, including clarity and modulus, when photocured.
Examples 42-47
[0211] A reaction mixture was formed by mixing the components listed in Table 66 and degassed
by applying vacuum at ambient temperature for about 17(±3) minutes. The amounts of
the reaction components are listed as the weight % of reaction components, without
diluent. The reaction mixture was mixed with the diluents listed in Table 67 to form
the reaction mixtures. The reaction mixture (75 µL) was then dosed at room temperature
and <0.1% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold to produce 8 BC/FC assemblies in a pallet. Eight pallets
were prepared, moved into the cure compartment (Compartment 2) and placed on a mirrored
surface. A quartz plate (12.50 mm x 6.25 mm x 0.50 mm) was placed over each pallet
and the lenses were cured for 20 minutes, at an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65 °C.
[0212] The molds for all the lenses were mechanically separated demolded (lenses remained
in FC). The lenses were dry released by pressing on the back of the front curve. Lenses
were extracted in DI water
[0213] All lenses were stored in borate buffered packing solution in lens vials and sterilized
at 122°C for 30 minutes. The properties of the lenses are shown in Table 68.
Table 66
| Base Formulation |
| Component |
% |
| mPDMS 1000 |
16.50 |
| OH-mPDMS, n=4 |
27.50 |
| NVP |
46.55 |
| HEMA |
6.75 |
| EGDMA |
0.45 |
| Norbloc |
1.75 |
| CGI 819 |
0.50 |
Table 67
| Ex# |
42 |
43 |
44 |
45 |
46 |
47 |
| Diluent @ 10% |
NONE |
100% TAA |
50/50 TAA/BA |
50/50 TAA/BAGE |
70/30 TAA/BAGE |
50/50 TAA/PG |
| Level |
0.00 |
10.00 |
10.00 |
10.00 |
10.00 |
10.00 |
| TAM |
N/A |
100.00 |
50.00 |
50.00 |
70.00 |
50.00 |
| BAGE |
N/A |
N/A |
N/A |
50.00 |
30.00 |
N/A |
| BA |
N/A |
N/A |
50.00 |
N/A |
N/A |
N/A |
| PG |
N/A |
N/A |
N/A |
N/A |
N/A |
50.00 |
Table 68
| Ex# |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
Diameter (mm) |
Residual NVP Wt% @ 20 min. |
| Mod. (psi) |
Elong. (%) |
| 42 |
53.7 (0.1) |
9 (1) |
40 (5) |
136 (16) |
142 (42) |
98 |
13.95 (0.11) |
1.76 (0.01) |
| 43 |
54.6 (0.3) |
8 (1) |
47 (4) |
127 (17) |
163 (36) |
93 |
13.62 (0.16) |
2.08 (0.12) |
| 44 |
60.0 (0.2) |
17 (0) |
82(8) |
92 (13) |
138 (40) |
98 |
14.38 (0.03) |
0.44 (0.03) |
| 45 |
60.8 (0.2) |
17 (1) |
84 (4) |
78 (10) |
162 (34) |
95 |
14.53 (0.03) |
0.27 (0.00) |
| 46 |
60.4 (0.3) |
13 (2) |
79 (6) |
90 (11) |
134 (39) |
96 |
14.49 (0.03) |
0.27 (0.01) |
| 47 |
60.5 (0.2) |
2 (0) |
81 (6) |
87 (12) |
121 (40) |
97 |
14.41 (0.04) |
0.49 (0.04) |
[0214] Example 42 displayed very low haze (9%) and advancing contact angle (40°), but a
modulus of 136, which in some cases is higher than desired. In Examples 43 through
47 various diluent mixtures were evaluated to determine their impact on lens properties.
In each of Example 43 through 47, 10% diluent was added, with different polyhydric
alcohols as codiluents. As can be seen from Examples 44 through 47 the inclusion of
a polyhydric alcohol decreased the modulus of the resulting lenses by up to about
40%. The lenses of Examples 42 and 43 displayed higher than desired deviations in
lens diameter, due to their high levels of extractables at the end of cure. Examples
44-47 show that inclusion of a polyhydric component as a codiluent can reduce the
level of extractables, and the variation in lens diameter.
Examples 47-52
[0215] A reaction mixture was formed by mixing the components listed in Table 69 and degassed
by applying vacuum at ambient temperature for about 17(±3) minutes. The reaction mixture
(75 µL) was then dosed at room temperature and <0.1% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold and the lenses were moved into Compartment 2 and cured
for 20 minutes, at an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65°C.
[0216] The molds for all the lenses were mechanically separated demolded (lenses remained
in FC). The lenses were dry released by pressing on the back of the front curve. Lenses
were extracted in DI water.
[0217] All lenses were stored in borate buffered packing solution in lens vials and sterilized
at 122°C for 30 minutes. The properties of the lenses are shown in Table 70.
Table 69
| BAGE (Wt. %) |
0.0% |
0.0% |
0.5% |
1.0% |
1.5% |
2.5% |
| Component |
47 |
48 |
49 |
50 |
51 |
52 |
| mPDMS 1000 |
16.50 |
16.50 |
16.50 |
16.50 |
16.50 |
16.50 |
| OH-mPDMS, n=4 |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
| NVP |
46.55 |
46.55 |
46.55 |
46.55 |
46.55 |
46.55 |
| HEMA |
6.75 |
6.75 |
6.75 |
6.75 |
6.75 |
6.75 |
| EGDMA |
0.45 |
0.45 |
0.45 |
0.45 |
0.45 |
0.45 |
| Norbloc |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
| CGI 819 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
| Diluent |
0 |
5.00 |
5.00 |
5.00 |
5.00 |
5.00 |
| TAM |
0 |
100.00 |
90.00 |
80.00 |
70.00 |
50.00 |
| BAGE |
0 |
0.00 |
10.00 |
20.00 |
30.00 |
50.00 |
Table 70
| Ex# |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
Diameter (mm) |
| Mod. (psi) |
Elong. (%) |
| 47 |
54 (0) |
7 (0) |
41 (7) |
133 (8) |
170 (31) |
95 |
14.09 (0.08) |
| 48 |
56 (0) |
8 (1) |
36 (13) |
130 (8) |
178 (33) |
93 |
13.96 (0.05) |
| 49 |
56 (0) |
10 (1) |
48 (4) |
115 (7) |
193 (28) |
101 |
14.04 (0.05) |
| 50 |
57 (0) |
18 (1) |
62 (8) |
110 (9) |
159 (22) |
98 |
14.27 (0.05) |
| 51 |
58 (0) |
18 (1) |
84(6) |
107 (8) |
157 (31) |
94 |
14.55 (0.02) |
| 52 |
59 (0) |
15 (1) |
83 (6) |
99 (7) |
169 (39) |
93 |
14.60 (0.05) |
[0218] Example 47 contained no diluent and displayed desirably low haze and advancing contact
angle. Examples 48 through 52 comprised 5 wt% diluent, with Examples 49 through 52
containing between 0.5 and 2.5 wt% BAGE as a codiluent. Examples 49 and 50 displayed
desirable advancing contact angles and reduced modulus compared with both the no diluent
formulation of Example 47 and Example 48 which contained t-amyl alcohol as the only
diluent.
Examples 53-59
[0219] The reaction components listed in Table 71 were combined with the diluents listed
in Table 72. The resulting reaction mixtures were dispensed into lens molds, cured,
and processed as described in Examples 42-47. The properties of the lenses were measured
and are shown in Table 73, below.
Table 71
| Base Formulation |
| Component |
% |
| mPDMS 1000 |
16.50 |
| OH-mPDMS, n=4 |
27.50 |
| NVP |
44.55 |
| HEMA |
8.75 |
| EGDMA |
0.45 |
| Norbloc |
1.75 |
| CGI 819 |
0.50 |
Table 72
| Diluent |
80 |
81 |
82 |
83 |
84 |
85 |
86 |
| TAA |
None |
5.0% |
4.9% |
4.75% |
4.5% |
4.0% |
2.5% |
| PVP K90 |
None |
None |
0.1% |
0.25% |
0.5% |
1.0% |
2.5% |
Table 73
| Lens |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
Dia. (mm) |
Residual NVP% |
| Mod. (psi) |
Elong. (%) |
| 80 |
54 (0) |
11 (1) |
71 (6) |
142 (8) |
164 (32) |
87 |
14.10 (0.05) |
0.69 90.04) |
| 81 |
55 (0) |
10 (1) |
48 (7) |
144 (7) |
153 (31) |
99 |
13.98 (0.03) |
0.13 (0.01) |
| 82 |
56 (0) |
11 (1) |
39 (8) |
140 (9) |
151 (43) |
93 |
14.00 (0.02) |
0.13 (0.00) |
| 83 |
56 (0) |
11 (0) |
64 (10) |
132 (10) |
181 (30) |
94 |
13.99 (0.04) |
0.13 (0.02) |
| 84 |
55 (0) |
11 (1) |
55 (4) |
115 (13) |
188 (36) |
97 |
14.02 (0.04) |
0.14 (0.01) |
| 85 |
55 (0) |
14 (1) |
54 (10) |
117 (12) |
105 (20) |
98 |
14.03 (0.05) |
0.17 (0.01) |
| 86 |
55 (0) |
36 (5) |
64 (7) |
122 (11) |
199 (34) |
90 |
14.13 (0.06) |
0.27 (0.1) |
[0220] Small amounts of PVP (0.1 to 2.5 w% based upon all components in the reaction mixtures)
were added with the diluent. Amounts of PVP between about 0.5 and 2.5 wt% (Examples
57-59) reduced modulus without negatively impacting advancing contact angle. The decrease
in modulus is surprising based upon the small amount of PVP added, and the fact that
the PVP used (molecular weight, K90) is a viscous liquid. Generally increasing the
viscosity of the reaction mixture tends to increase modulus.
Examples 87-102
[0221] The effect of crosslinker on lens properties was evaluated using the base formulation
in Table 74, and the crosslinker type, amount and the concentration of NVP shown in
Table 75, with concentration of the reactive components, excluding the diluent, adding
up to 100 wt%.
Table 74
| Base Formulation |
| Component |
% |
| mPDMS 1000 |
19 |
| OH-mPDMS, n=4 |
27.50 |
| NVP |
44.55 |
| HEMA |
6.75 |
| Norbloc |
1.75 |
| CGI 819 |
0.50 |
| TAA |
5 |
Table 75
| Ex.# |
[NVP] |
[EGDMA] |
[AMA] |
[HEMA-Vc] |
| 87 |
44.25 |
0.25 |
0 |
0 |
| 88 |
44 |
0.5 |
0 |
0 |
| 89 |
43.5 |
1 |
0 |
0 |
| 90 |
43 |
1.5 |
0 |
0 |
| 91 |
44.34 |
0 |
0.16 |
0 |
| 92 |
44.18 |
0 |
0.32 |
0 |
| 93 |
43.87 |
0 |
0.63 |
0 |
| 94 |
43.56 |
0 |
0.94 |
0 |
| 95 |
44.25 |
0 |
0 |
0.25 |
| 96 |
44 |
0 |
0 |
0.5 |
| 97 |
43.5 |
0 |
0 |
1 |
| 98 |
43 |
0 |
0 |
1.5 |
| 99 |
44.05 |
0.45 |
0 |
0 |
| 100 |
43.05 |
0.45 |
0 |
1 |
| 101 |
42.05 |
0.45 |
0 |
2 |
| 102 |
41.05 |
0.45 |
0 |
3 |
[0222] The reaction mixtures were degassed by applying vacuum at ambient temperature for
about 17(±3) minutes. The reaction mixture (75 µL) was then dosed at room temperature
and <0.1% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold and the lenses were moved into Compartment 2 and cured
for 20 minutes, at an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65°C.
[0223] The molds for all the lenses were mechanically separated and the lenses remained
in the FC. The lenses were dry released by pressing on the back of the front curve.
Lenses were extracted in DI water
All lenses were stored in borate buffered packing solution in lens vials and sterilized
at 122°C for 30 minutes.
[0224] The ability of the lenses to recover from mechanical stress, such as folding was
evaluated. A crease was generated in each lens by placing a folded unsterilized lens
between two rectangular glass plates (12.5 cm x 6.3 cm x 0.5 cm (∼113 g)) for five
minutes. The lens was subsequently sterilized and visually inspected using a DL2 (17.5X)
and Optimec, to discern the level of recovery. • Increasing degrees of creasing/stress
were created in unsterilized lenses by using 2, 3, 4 or 5 top plates. The results
of the stress test are shown in Tables 76-79.
[0225] The stress test values for three commercial lenses, ACUVUE OASYS with HYDRACLEAR
Plus, Biofinity and Clariti lenses are shown as controls.
[0226] The properties of the lenses were measured and are shown in Table 80.
Table 76
| Post Sterilization Inspection - DL2 (17.5X) and Optimec |
| Ex# |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 87 |
G |
DL |
DL |
DL |
DL |
DL |
| 88 |
G |
DL |
DL |
DL |
DL |
DL |
| 89 |
G |
DL |
DL |
DL |
DL |
DL |
| 90 |
G |
DL |
DL |
DL |
DL |
DL |
| Oasys |
G |
G |
G |
G |
G |
G |
| Clariti |
G |
G |
G |
G |
G |
G |
| Biofinity |
G |
G |
G |
G |
G |
G |
G = Good (No Detectable Line)
DL = Definitive Line |
Table 77
| Post Sterilization Inspection - DL2 (17.5X) and Optimec |
| Lens |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 91 |
G |
FL |
FL |
FL |
FL |
FL |
| 92 |
G |
VFL |
VFL |
VFL |
VFL |
VFL |
| 93 |
G |
G |
G |
G |
G |
G |
| 94 |
G |
G |
G |
G |
G |
G |
G = Good (No Detectable Line)
FL = Faint Line
VFL = Very Faint Line |
Table 78
| Post Sterilization Inspection - DL2 (17.5X) and Optimec |
| Lens |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 95 |
G |
FL |
FL |
FL |
FL |
FL |
| 96 |
G |
FL |
FL |
FL |
FL |
FL |
| 97 |
G |
G |
G |
G |
G |
G |
| 98 |
G |
G |
G |
G |
G |
G |
G = Good (No Detectable Line)
FL = Faint Line |
Table 79
| Post Sterilization Inspection-DL2 (17.5X) and Optimec |
| Lens |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 99 |
G |
DL |
DL |
DL |
DL |
DL |
| 100 |
G |
G |
G |
G |
G |
G |
| 101 |
G |
G |
G |
G |
G |
G |
| 102 |
G |
G |
G |
G |
G |
G |
Table 80
| Lens |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 87 |
56(0) |
17 (1) |
46(6) |
104 (9) |
239 (52) |
99 |
| 88 |
52 (0) |
11 (2) |
46 (6) |
156 (8) |
174 (42) |
99 |
| 89 |
46 (0) |
8 (1) |
41 (12) |
326 (25) |
52 (19) |
101 |
| 90 |
42 (1) |
4 (0) |
44 (3) |
454 (51) |
45 (6) |
101 |
| 91 |
55 (0) |
13 (1) |
92(3) |
98 (5) |
259 (955) |
104 |
| 92 |
52 (0) |
7 (1) |
8 (10) |
135 (8) |
203 (32) |
101 |
| 93 |
47 (0) |
4 (0) |
102 (7) |
194(13) |
153 (27) |
105 |
| 94 |
42 (0) |
3 (0) |
100 (5) |
294 (29) |
93 (27) |
92 |
| 95 |
55 (0) |
12 (0) |
82 (7) |
97 (10) |
266 (61) |
95 |
| 96 |
51 (0) |
8(1) |
91 (9) |
137 (6) |
208 (48) |
100 |
| 97 |
47 (1) |
5 (1) |
92 (8) |
211 (11) |
135 (27) |
103 |
| 98 |
44 (0) |
5(1) |
102 (6) |
284 (15) |
85 (25) |
99 |
| 99 |
NT |
NT |
35 (7) |
155 (15) |
165 (36) |
NT |
| 100 |
NT |
NT |
80 (12) |
317 (38) |
53 (21) |
NT |
| 101 |
NT |
NT |
102 (18) |
538 (48) |
33 (7) |
NT |
| 102 |
NT |
NT |
109 (7) |
678 (74) |
33 (7) |
NT |
Examples 103-108
[0227] Examples 87-90 were repeated using a mixture of EGDMA and TAC as shown in Table 81
below. The recovery of the lenses is shown in Table 82, and the properties of the
lenses are shown in Table 83.
Table 81
| Component |
103 |
104 |
105 |
106 |
107 |
108 |
| NVP |
44.30 |
44.20 |
44.10 |
44.00 |
43.80 |
43.55 |
| EGDMA |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
| TAC |
0.00 |
0.10 |
0.20 |
0.30 |
0.50 |
0.75 |
Table 82
| Post Sterilization Inspection-DL2 (17.5X) and Optimec |
| Lens |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 103 |
G |
DL |
DL |
DL |
DL |
DL |
| 104 |
G |
VFL |
VFL |
VFL |
VFL |
VFL |
| 105 |
G |
G |
G |
G |
G |
G |
| 106 |
G |
G |
G |
G |
G |
G |
| 107 |
G |
G |
G |
G |
G |
G |
| 108 |
G |
G |
G |
G |
G |
G |
Table 83
| Lens |
%H2O |
% Haze |
DCA |
Mechanicals |
Dk |
| Mod. (psi) |
Elong. (%) |
| 103 |
56 (0) |
16 (1) |
65 (4) |
93 (9) |
236 (72) |
99 |
| 104 |
55 (0) |
8 (0) |
62 (4) |
132 (6) |
217 (39) |
101 |
| 105 |
55 (0) |
5 (0) |
62 (2) |
124 (10) |
258 (43) |
94 |
| 106 |
53 (0) |
4 (1) |
70 (4) |
143 (16) |
169 (53) |
98 |
| 107 |
51 (0) |
3 (0) |
80 (7) |
154 (13) |
133 (45) |
94 |
| 108 |
48 (0) |
3 (0) |
97 (4) |
170 (17) |
180 (34) |
88 |
Examples 109-114
[0228] Lenses were made using the formulations shown in Table 84 and the process described
in Examples 87-102. Lens properties were measured and are shown in Table 85.
Table 84
| Ex.# |
109 |
110 |
112 |
112 |
113 |
114 |
| mPDMS 1000 |
19.35 |
19.35 |
19.35 |
19.35 |
19.35 |
19.35 |
| OH-mPDMS (n=4) |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
27.50 |
| VMA |
0.00 |
8.00 |
12.00 |
22.00 |
32.00 |
44.00 |
| HEMA |
6.50 |
6.50 |
6.50 |
6.50 |
6.50 |
6.50 |
| NVP |
44.00 |
36.00 |
32.00 |
22.00 |
12.00 |
0.00 |
| TEGDMA |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
| TAC |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
0.20 |
| Norbloc |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
1.75 |
| CGI 819 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
0.50 |
| Diluent |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
| TAM |
N/A |
N/A |
N/A |
N/A |
N/A |
N/A |
Table 85
| Lens |
% H2O |
% Haze |
DCA |
Mechanicals |
Dk |
Res. NVP |
Res. VMA |
| Mod. (psi) |
Elong. (%) |
| 109 |
55 (0) |
6 (0) |
55 (3) |
95 (6) |
270 (34) |
96 |
0.8 (0.02) |
N/A |
| 110 |
56 (0) |
6 (0) |
67 (5) |
104 (7) |
233 (49) |
100 |
NT |
NT |
| 111 |
56 (0) |
5 (0) |
58 (4) |
100 (8) |
258 (36) |
100 |
0.51 (0.02) |
1.15 (0.08) |
| 112 |
58 (0) |
6 (0) |
56 (9) |
91 (9) |
223 (54) |
96 |
0.4 (0.04) |
2.2 (0.2) |
| 113 |
58 (0) |
7 (0) |
56 (5) |
92 (10) |
260 (62) |
103 |
0.3 (0.01) |
2.98 (0.06) |
| 114 |
58 (0) |
13 (2) |
50 (10) |
86(7) |
262 (54) |
106 |
N/A |
4.52 (0.61) |
Table 86
| Post Sterilization Inspection-DL2 (17.5X) and Optimec |
| Ex# |
Control (0 Plate) |
1 Plate |
2 Plates |
3 Plates |
4 Plates |
5 Plates |
| 109 |
G |
G |
G |
G |
G |
G |
| 110 |
G |
G |
G |
G |
G |
G |
| 111 |
G |
G |
G |
G |
G |
G |
| 112 |
G |
G |
G |
G |
G |
G |
| 113 |
G |
G |
G |
G |
G |
G |
| 114 |
G |
G |
G |
G |
G |
G |
Examples 115-117
[0229] A reaction mixture was formed by mixing the components listed in Table 87 with 20
wt% of a 50:50 mixture of TAA and decanoic acid and degassed by applying vacuum at
ambient temperature for about 17(±3) minutes. The reaction mixture (75 µL) was then
dosed at room temperature and <0.1% O
2, into thermoplastic contact lens molds (FC - Zeonor, BC Polypropylene) which had
been degassed in N
2 box at RT (Compartment 1, Figure 2) for a minimum of 12 hours prior to dosing. The
BC was placed on the FC mold and the lenses were moved into Compartment 2 and cured
for 20 minutes, at an intensity of 4 - 5 mW/cm
2, <0.1% O
2, and 62 - 65°C.
[0230] Lenses were released in 50/50 IPA/water, extracted in 70/30 IPA/water and subsequently
equilibrated in de-ionized water. Lenses were transferred into vials containing borate
buffered saline for at least 24 hours and then autoclaved at 122°C for 30 minutes.
Lens properties were measured and are reported in Table 88, below.
Table 67
| Component |
115 |
116 |
117 |
| mPDMS 1000 |
20.50 |
20.50 |
20.50 |
| NVP |
65.50 |
70.50 |
72.50 |
| DMA |
0.00 |
0.00 |
0.00 |
| HEMA |
10.75 |
5.75 |
3.25 |
| TEGDMA |
1.00 |
1.00 |
1.50 |
| Norblock |
2.00 |
2.00 |
2.00 |
| CGI 819 |
0.25 |
0.25 |
0.25 |
Table 68
| Ex.# Lens |
%H2O |
% Haze |
DCA |
Mechanicals |
Dk |
HO:Si (mol) |
| Mod. (psi) |
Elong. (%) |
| 115 |
70.5 (0.2) |
4 (1) |
55 (6) |
51.0(6.3) |
208.7 (37.5) |
48.9 |
0.36 |
| 116 |
78.1 (0.1) |
6 (0) |
50 (6) |
30.8 (2.6) |
224.9 (29.6) |
58.1 |
0.19 |
| 117 |
77.9 (0.3) |
30 (1) |
51 (7) |
29.7 (2.2) |
172.0 (36.0) |
61.0 |
0.11 |
Example 118: Preparation of 2-hydroxybutyl methacrylate (HBMA)
[0231] A blend of 72 grams 1,2-epoxybutane (Aldrich), 0.85 g 4-methoxyphenol (Aldrich),
and 6.5 g potassium hydroxide was stirred in a 500 ml round bottomed flask equipped
with an addition funnel and thermocouple thermometer. 172 g methacrylic acid was added
via the addition funnel, and the blend was slowly to 75°C, and stirred overnight under
an air, then increased to 88°C for 4 hours. The mixture was cooled, and 700 ml of
2.0 N NaOH was added to the mixture in a separatory funnel. The upper layer was washed
with borate buffered saline three times. Ethyl ether (200 ml) was added to the combined
saline washes to extract any product. The combined organic layers were dried over
NaSO
4. The NaSO
4 was filtered out and the product was distilled (90-98°C/∼4 mm Hg). 17.5 g product
was collected, to which was added 4 mg 4-methoxyphenol.
1H NMR: 6.1 ppm (1H, m), 5.5 (1H, m), 4.8 (0.25H m), 4.2 (0.64 H, dd, 8.1 and 11.7
Hz), 4.0 (0.64 Hz, dd, 6.9 and 11.4 Hz), 3.6-3.8 1.26H, m), 2.3 (OH, br s), 1.9 (3
H, m), 1.4-1.7 (2 H, m), 0.9 (3H, m); consistent with a blend of 2-hydroxy-1-propylmethacrylate
and 1-hydroxy-2-propylmethacrylate.
Example 119: Preparation of dimethylhydroxyethylmethacrylate
[0232] The same procedure as for HBMA was used, but substituting 1,2-epoxy-2-methylpropane
for the 1,2-epoxypropane. The product was isolated by distillation at 47-48°/0.4-0.6
mm Hg..
1H NMR: 6.1 ppm (1H, s), 5.5 (1H, m), 4.0 (2H, s), 2.1 (OH, br s), 1.9 (3 H, s), 1.2
(6 H, m); consistent 2-hydroxy-2-methyl propylmethacrylate (dimethylhydroxyethylmethacrylate).
Example 120: Preparation of VINAL
[0233] 4.82 g vinyl chloroformate was added to a mixture of 8.19 g β-alanine (Aldrich) in
74 ml acetonitrile. The resulting mixture was refluxed for 2 hours, then cooled to
room temperature and allowed to sit for 2 hours. It was filtered and solvent was removed
under reduced pressure. The crude product was dissolved in 30 ml distilled water and
washed three times with ethyl acetate. The combined ethyl acetate washes were washed
with 50 ml deionized water. Solvent was evaporated from the combined ethyl acetate
washes to yield 4.5 g product as a fluffy yellowish solid.
1H NMR: 7.1 ppm (dd, 1H), 5.4 ppm (br s, OH), 4.7 ppm (dd, 1H), 4.4 ppm (dd, 1H), 3.5
ppm (q, 2H), 2.6 ppm (t, 2H).
1. A silicone hydrogel formed from a reaction mixture comprising 30 to 75 wt% of at least
one slow-reacting hydrophilic monomer having a slow-reacting hydrophilic monomer kinetic
half life;
at least one silicone-containing component having a silicone-containing component
kinetic half life, which may be optionally substituted with at least one hydroxyl
containing group;
at least one visible light photoinitiator;
at least one hydroxyl-containing component selected from said silicone-containing
components substituted with at least one hydroxyl group, at least one hydroxyalkyl
monomer, and mixtures thereof; and
at least one UV absorbing compound,
wherein the ratio of said slow-reacting hydrophilic component half life to said silicone-containing
component half life is at least 2, and
wherein polymerization of the reaction mixture is initiated using visible light.
2. The silicone hydrogel of any preceding claim wherein said kinetic half life ratio
is at least 3, or is at least 5.
3. The silicone hydrogel of any preceding claim further comprising a Dk of at least 80,
or at least 85, wherein Dk is measured according to the method described in the "Oxygen
Permeability (Dk)" section of the detailed description.
4. The silicone hydrogel of any preceding claim further comprising a %haze of less than
70%, or less than 50%, or less than 10%, wherein %haze is measured according to the
method described in the "Haze Measurement" section of the "Haze Solubility Parameter"
of the detailed description.
5. The silicone hydrogel of any preceding claim further comprising a water content of
at least 55%, or at least 60%.
6. The silicone hydrogel of any preceding claim further comprising a modulus of less
than 150 psi, or 100 psi or less, wherein modulus is measured according to the method
described in the "Modulus" section of the detailed description.
7. The silicone hydrogel of any preceding claim wherein said at least one UV absorbing
compound is reactive.
8. The silicone hydrogel of any preceding claim wherein said at least one UV absorbing
compound is selected from benzotriazoles, or
wherein said at least one UV absorbing compound is selected from the group consisting
of reactive 2-(2'-hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, 2-hydroxyphenyltriazines,
oxanilides, cyanoacrylates, salicylates and 4-hydroxybenzoates, or
wherein said at least one UV absorbing compound is selected from the group consisting
of 2-(2'-hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazole, 5-vinyl and 5-isopropenyl
derivatives of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole and 4-acrylates or 4-methacrylates
of 2-(2,4-dihydroxyphenyl)-2H-benzotriazole or 2-(2,4-dihydroxyphenyl)-1,3-2H-dibenzotriazole,
and mixtures thereof.
9. The silicone hydrogel of any preceding claim comprising between 0.5 and 4 wt.%, optionally
between 1 wt% and 2 wt%, of at least one UV absorber.
10. The silicone hydrogel of any preceding claim wherein said reaction mixture is free
of diluent.
11. The silicone hydrogel of any preceding claim wherein said reaction mixture is free
of TRIS (3-methacryloxypropyltris(trimethylsiloxy)silane).
12. The silicone hydrogel of any preceding claim wherein said reaction mixture is free
of silicone containing macromers or prepolymers.
13. The silicone hydrogel of any preceding claim wherein said slow-reacting hydrophilic
monomer comprises a reactive group selected from the group consisting of (meth)acrylamides,
vinyls, allyls and combinations thereof and said silicone-containing component comprises
a reactive group selected from the group consisting of (meth)acrylates, styryls, amides
and mixtures thereof, optionally
wherein said slow-reacting hydrophilic monomer comprises a reactive group selected
from the group consisting of vinyls, allyls and combinations thereof and said silicone-containing
component comprises a reactive group selected from the group consisting of (meth)acrylates,
styryls, amides and mixtures thereof.
14. The silicone hydrogel of any preceding claim wherein said slow-reacting hydrophilic
monomer comprises a reactive group selected from the group consisting of N-vinyl amides,
O-vinyl carbamates, O-vinyl carbonates, N-vinyl carbamates, O-vinyl ethers, O-2-propenyl,
wherein the vinyl or allyl groups may be further substituted with a methyl group.
15. The silicone hydrogel of any preceding claim wherein said slow reacting hydrophilic
monomer comprises at least one hydrophilic group selected from the group consisting
of hydroxyls, amines, ethers, amides, ammonium groups, carboxylic acid, carbamates
and combinations thereof, optionally
wherein said slow reacting hydrophilic monomer comprises at least one hydrophilic
group selected from the group consisting of hydroxyls, ethers, amides, carboxylic
acid combinations thereof.
16. The silicone hydrogel of claims 1 to 12 wherein said slow reacting hydrophilic monomer
is selected from N-vinylamide monomer of Formula I, a vinyl pyrrolidone of Formula
II-IV, n-vinyl piperidone of Formula V :
wherein R is H or methyl;
R1, R2, R3, R6, R7, R10, and R11 are independently selected from H, CH3, CH2CH3 , CH2CH2CH3, C(CH3)2;
R4 and R8 are independently selected from CH2, CHCH3 and C(CH3);
R5 is selected from H, methyl, ethyl; and
R9 is selected from CH=CH2, CCH3=CH2, and CH=CHCH3.
17. The silicone hydrogel of claim 16 wherein the slow-reacting hydrophilic monomer is
selected from the vinyl pyrrolidone of Formula II or IV or the N-vinyl amide monomer
of Formula I, and the total number of carbon atoms in R1 and R2 is 4 or less, or
wherein the slow-reacting hydrophilic monomer is selected from a vinyl pyrrolidone
of Formula III or IV and R6 is methyl, R7 is hydrogen, R9 is CH=CH2, R10 and R11 are H, or
wherein the slow-reacting hydrophilic monomer is selected from the slow-reacting hydrophilic
monomer is selected from ethylene glycol vinyl ether (EGVE), di(ethylene glycol) vinyl
ether (DEGVE), N-vinyl pyrrolidone (NVP), 1-methyl-3-methylene-2-pyrrolidone, 1-methyl-5-methylene-2-pyrrolidone,
5-methyl-3-methylene-2-pyrrolidone; 1-ethyl-5-methylene-2-pyrrolidone, N-methyl-3-methylene-2-pyrrolidone,
5-ethyl-3-methylene-2-pyrrolidone, 1-n-propyl-3-methylene-2-pyrrolidone, 1-n-propyl-5-methylene-2-pyrrolidone,
1-isopropyl-3-methylene-2-pyrrolidone, 1-isopropyl-5-methylene-2-pyrrolidone, N-vinyl-N-methyl
acetamide (VMA), N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide,
N-vinyl acetamide, N-vinyl isopropylamide, allyl alcohol, N-vinyl caprolactam, N-2-hydroxyethyl
vinyl carbamate, N-carboxy-β-alanine N-vinyl ester; N-carboxyvinyl-β-alanine (VINAL),
N-carboxyvinyl-α-alanine and mixtures thereof, optionally
wherein the slow-reacting hydrophilic monomer is selected from NVP, VMA and 1-methyl-5-methylene-2-pyrrolidone,
optionally wherein the slow-reacting hydrophilic monomer comprises NVP .
18. The silicone hydrogel of any preceding claim wherein said silicone-containing component
comprises at least one hydroxyl group.
19. The silicone hydrogel of any preceding claim further comprising at least one hydroxyalkyl
monomer.
20. The silicone hydrogel of claim 19 wherein said hydroxyalkyl monomer is selected from
hydroxyalkyl (meth)acrylate or (meth)acrylamide monomer of Formula VII or a styryl
compound of Formula VIII
wherein R1 is H or methyl,
X is O or NR16, R16 is a H, C1 to C4 alkyl, which may be further substituted with at least one OH, and
R17 is selected from C2-C4 mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having 1-10 repeating
units.
21. The silicone hydrogel of claim 20 wherein R
1 is H or methyl, X is oxygen and R
17 is selected from C
2-C
4 mono or dihydroxy substituted alkyl, and poly(ethylene glycol) having 1-10, or 2-20,
repeating units, or
wherein said hydroxyalkyl monomer is selected from 2-hydroxyethyl methacrylate, 2-hydroxyethyl
acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1-hydroxypropyl-2-(meth)acrylate,
2-hydroxy-2-methyl-propyl (meth)acrylate, 3-hydroxy-2,2-dimethyl-propyl (meth)acrylate,
4-hydroxybutyl (meth)acrylate, glycerol (meth)acrylate, 2-hydroxyethyl (meth)acrylamide,
polyethyleneglycol monomethacrylate, bis-(2-hydroxyethyl) (meth)acrylamide, 2,3-dihydroxypropyl
(meth)acrylamide, and mixtures thereof, optionally
wherein said hydroxyalkyl monomer is selected from the group consisting of 2-hydroxyethyl
methacrylate, glycerol methacrylate, 2-hydroxypropyl methacrylate, hydroxybutyl methacrylate,
3-hydroxy-2,2-dimethylpropyl methacrylate, and mixtures thereof, optionally
wherein said hydroxyalkyl monomer comprises 2-hydroxyethyl methacrylate, 3-hydroxy-2,2-dimethyl-propyl
methacrylate, glycerol methacrylate and mixtures comprising them.
22. The silicone hydrogel of any preceding claim wherein the at least one silicone-containing
monomer is monofunctional and comprises (a) a reactive group selected from (meth)acrylates,
styryls, amides and mixtures thereof and (b) a polydialkyl siloxane chain and may
optionally contain fluorine.
23. The silicone hydrogel of any preceding claim wherein said silicone-containing component
is selected from mono (meth)acryloxyalkyl polydialkylsiloxane monomer of Formula IX
or the styryl polydialkylsiloxane monomer of Formula X:
wherein R12 is H or methyl;
X is O or NR16;
each R14 is independently a C1 to C4 alkyl which may be fluorine substituted, or phenyl;
R15 is a C1 to C4 alkyl;
R13 is a divalent alkyl group, which may further be functionalized with a group selected
from the group consisting of ether groups, hydroxyl groups, carbamate groups and combinations
thereof;
a is 3 to 50;
R16 is selected from H, C1-4, which may be further substituted with one or more hydroxyl
groups.
24. The silicone hydrogel of claim 23 wherein each R14 is independently selected from ethyl and methyl groups, optionally wherein all R14 are methyl, or
wherein R12 and each R14 are methyl, or
wherein at least one R14 is 3,3,3-trifluoropropyl, or
wherein R13 is selected from C1-C6 alkylene groups which may be substituted with ether, hydroxyl
and combinations thereof, or
wherein R13 is selected from C1 or C3-C6 alkylene groups which may be substituted with ether,
hydroxyl and combinations thereof, or
wherein a is 5 to 15, or
whereinR16 is H or methyl, or
wherein said monomethacryloxyalkylpolydimethylsiloxane methacrylate is selected from
the group consisting of monomethacryloxypropyl terminated mono-n-butyl terminated
polydimethylsiloxane, monomethacryloxypropyl terminated mono-n-methyl terminated polydimethylsiloxane,
monomethacryloxypropyl terminated mono-n-butyl terminated polydiethylsiloxane, monomethacryloxypropyl
terminated mono-n-methyl terminated polydiethylsiloxane, N-(2,3-dihydroxypropane)-N'-(propyl
tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide, α-(2-hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-octamethylpentasiloxane,
and mixtures thereof, optionally
wherein said monomethacryloxyalkylpolydimethylsiloxane methacrylate is selected from
the group consisting of monomethacryloxypropyl terminated mono-n-butyl terminated
polydimethylsiloxane, monomethacryloxypropyl terminated mono-n-methyl terminated polydimethylsiloxane,
N-(2,3-dihydroxypropane)-N'-(propyl tetra(dimethylsiloxy) dimethylbutylsilane)acrylamide,
and mixtures thereof, optionally
wherein said slow reacting hydrophilic monomer and said hydroxyl monomer form a molar
ratio of hydroxyl groups to the slow-reacting hydrophilic monomer of between 0.15
and 0.4.
25. The silicone hydrogel of any preceding claim further comprising at least one crosslinking
monomer.
26. The silicone hydrogel of any of claims 18 to 25 wherein said slow-reacting hydrophilic
monomer is selected from N-vinylpyrrolidone, N-vinylacetamide, 1-methyl-3-methylene-2-pyrrolidone,
1-methyl-5-methylene-2-pyrrolidone, 5-methyl-3-methylene-2-pyrrolidone, and mixtures
thereof.
27. The silicone hydrogel of any preceding claim further comprising an advancing contact
angle of less than 80°, or less than 70°.
28. A silicone hydrogel formed from the reaction mixture of claim 1,
wherein at least one of said silicone-containing component, optional additional hydrophilic
components or both comprises at least one hydroxyl group and wherein said slow-reacting
hydrophilic component and said silicone-containing component are selected to have
a conversion ratio at 90% conversion of greater than 10, or at least 20, or at least
30, or at least 90,
wherein the "conversion ratio at 90 % conversion" is the ratio of the concentration
of the slow-reacting hydrophilic monomer to concentration of the slowest reacting
silicone-containing monomer at 90% conversion of the slowest reacting silicone-containing
monomer.
29. The silicone hydrogel of any preceding claim formed from a reaction mixture comprising
37 to 75 wt%, or 37 to 70 wt%, or 39 to 60 wt%, of the at least one slow-reacting
hydrophilic monomer having a slow-reacting hydrophilic monomer kinetic half life.
30. The silicone hydrogel of any preceeding claim further comprising from 5 to 20 wt%
of at least one polar diluent, based upon all components in the reaction mixture,
optionally
wherein said polar diluent is selected from the group consisting of carboxylic acids,
secondary and tertiary alcohols.
31. The silicone hydrogel of claim 30 wherein said diluent further comprises at least
polyhydric codiluent, optionally
wherein said polyhydric codiluent is present in an amount between 0.5 and 5 wt%, based
upon all components in the reaction mixture, or
wherein said polyhydric codiluent is selected from the group consisting of glycerin,
boric acid, boric acid glycerol esters, polyalkylene glycols and mixtures thereof.
32. The silicone hydrogel of any preceding claim wherein said reaction mixture further
comprises at least one slow reacting crosslinker and at least one fast reacting crosslinker,
optionally
wherein said slow reacting crosslinkers have only vinyl reactive functionality and
said fast reacting crosslinkers have (meth)acrylate reactive functionality only, or
wherein said slow reacting crosslinker comprises TAC (triallylcyanurate) and said
fast reacting crosslinker is selected from the group consisting of EDGMA (ethylene
glycol dimethacrylate), TEGDMA (tetraethyleneglycol dimethacrylate) and mixtures thereof.
33. The silicone hydrogel of any preceding claim wherein said reaction mixture is free
from additional hydrophilic components.
34. The silicone hydrogel of claim 30 wherein said reaction mixture comprises less than
5% of intermediate reacting hydrophilic components.
35. The silicone hydrogel of claim 32 wherein said at least one slow reacting crosslinker
and at least one fast reacting crosslinker are each present in said reaction mixture
in amounts between 0.7 to 6.0 mmol/100 g, or 0.7 to 4.0 mmol/100 g, of polymerizable
components, or
wherein said slow reacting crosslinkers have only vinyl reactive functionality and
said fast reacting crosslinkers have (meth)acrylate reactive functionality only and
wherein all crosslinkers are present in an amount less than 2 wt%, or
wherein the amount of all crosslinker in the reactive mixture is between 0.10% and
1.0%, or between 0.10 and 2%, excluding diluent.
36. A process for forming the silicone hydrogel of any preceding claim comprising photocuring
the reaction mixture, wherein said photocuring is completed in 30 minutes or less.
1. Silicon-Hydrogel, gebildet aus einem Reaktionsgemisch umfassend 30 bis 75 Gew.-% an
wenigstens einem langsam reagierenden hydrophilen Monomer mit einer kinetischen Halbwertszeit
des langsam reagierenden hydrophilen Monomers;
wenigstens eine siliconhaltige Komponente mit einer kinetischen Halbwertszeit der
siliconhaltigen Komponente, die gegebenenfalls mit wenigstens einer hydroxyhaltigen
Gruppe substituiert sein kann;
wenigstens einen Photoinitiator für sichtbares Licht;
wenigstens eine hydroxyhaltige Komponente ausgewählt aus den siliconhaltigen Komponenten,
die mit wenigstens einer Hydroxygruppe substituiert sind, wenigstens einem Hydroxyalkylmonomer
und Gemischen davon; und
wenigstens eine UV-absorbierende Verbindung,
wobei das Verhältnis der Halbwertszeit der langsam reagierenden hydrophilen Komponente
zu der Halbwertszeit der siliconhaltigen Komponente wenigstens 2 beträgt und
wobei Polymerisation des Reaktionsgemischs unter Verwendung von sichtbarem Licht eingeleitet
wird.
2. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Verhältnis der
kinetischen Halbwertszeiten wenigstens 3 beträgt oder wenigstens 5 beträgt.
3. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend einen Dk-Wert
von wenigstens 80 oder wenigstens 85, wobei Dk gemäß dem in dem Abschnitt "Sauerstoffdurchlässigkeit
(Dk)" der ausführlichen Beschreibung beschriebenen Verfahren gemessen ist.
4. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend eine %-Trübung
von weniger als 70 % oder weniger als 50 % oder weniger als 10 %, wobei %-Trübung
gemäß dem in dem Abschnitt "Trübungsmessung" von "Trübungs-Löslichkeitsparameter"
der ausführlichen Beschreibung beschriebenen Verfahren gemessen ist.
5. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend einen Wassergehalt
von wenigstens 55 % oder wenigstens 60 %.
6. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, das ferner einen Modul von
weniger als 150 psi oder 100 psi oder weniger aufweist, wobei der Modul gemäß dem
in dem Abschnitt "Modul" der ausführlichen Beschreibung beschriebenen Verfahren gemessen
ist.
7. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei die wenigstens eine
UV-absorbierende Verbindung reaktionsfähig ist.
8. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei die wenigstens eine
UV-absorbierende Verbindung ausgewählt ist aus Benzotriazolen oder
wobei die wenigstens eine UV-absorbierende Verbindung ausgewählt ist aus der Gruppe
bestehend aus reaktionsfähigen 2-(2'-Hydroxyphenyl)benzotriazolen, 2-Hydroxybenzophenonen,
2-Hydroxyphenyltriazinen, Oxaniliden, Cyanoacrylaten, Salicylaten und 4-Hydroxybenzoaten
oder
wobei die wenigstens eine UV-absorbierende Verbindung ausgewählt ist aus der Gruppe
bestehend aus 2-(2'-Hydroxy-5-methacrylyloxyethylphenyl)-2H-benzotriazol, 5-Vinyl-
und 5-Isopropenylderivaten von 2-(2,4-Dihydroxyphenyl)-2H-benzotriazol und 4-Acrylaten
oder 4-Methacrylaten von 2-(2,4-Dihydroxyphenyl)-2H-benzotriazol oder 2-(2,4-Dihydroxyphenyl)-1,3-2H-dibenzotriazol
und Gemischen davon.
9. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, umfassend zwischen 0,5 und
4 Gew.-%, gegebenenfalls zwischen 1 Gew.-% und 2 Gew.-%, an wenigstens einem UV-Absorber.
10. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Reaktionsgemisch
frei von Verdünnungsmittel ist.
11. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Reaktionsgemisch
frei von TRIS (3-Methacryloxypropyltris(trimethylsiloxy)silan) ist.
12. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Reaktionsgemisch
frei von siliconhaltigen Makromeren oder Präpolymeren ist.
13. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das langsam reagierende
hydrophile Monomer eine reaktionsfähige Gruppe ausgewählt aus der Gruppe bestehend
aus (Meth)acrylamiden, Vinylen, Allylen und Kombinationen davon umfasst und die siliconhaltige
Komponente eine reaktionsfähige Gruppe ausgewählt aus der Gruppe bestehend aus (Meth)acrylaten,
Styrylen, Amiden und Gemischen davon umfasst, gegebenenfalls
wobei das langsam reagierende hydrophile Monomer eine reaktionsfähige Gruppe ausgewählt
aus der Gruppe bestehend aus Vinylen, Allylen und Kombinationen davon umfasst und
die siliconhaltige Komponente eine reaktionsfähige Gruppe ausgewählt aus der Gruppe
bestehend aus (Meth)acrylaten, Styrylen, Amiden und Gemischen davon umfasst.
14. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das langsam reagierende
hydrophile Monomer eine reaktionsfähige Gruppe ausgewählt aus der Gruppe bestehend
aus N-Vinylamiden, O-Vinylcarbamaten, O-Vinylcarbonaten, N-Vinylcarbamaten, O-Vinylethern,
O-2-Propenyl umfasst, wobei die Vinyl- oder Allylgruppen ferner mit einer Methylgruppe
substituiert sein können.
15. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das langsam reagierende
hydrophile Monomer wenigstens eine hydrophile Gruppe ausgewählt aus der Gruppe bestehend
aus Hydroxylen, Aminen, Ethern, Amiden, Ammoniumgruppen, Carbonsäure, Carbamaten und
Kombinationen davon umfasst, gegebenenfalls
wobei das langsam reagierende hydrophile Monomer wenigstens eine hydrophile Gruppe
ausgewählt aus der Gruppe bestehend aus Hydroxylen, Ethern, Amiden, Carbonsäure und
Kombinationen davon umfasst.
16. Silicon-Hydrogel gemäß Ansprüchen 1 bis 12, wobei das langsam reagierende hydrophile
Monomer ausgewählt ist aus einem N-Vinylamid-Monomer der Formel I, einem Vinylpyrrolidon
der Formeln II-IV, einem n-Vinylpiperidon der Formel V:
wobei R H oder Methyl ist;
R1, R2, R3, R6, R7, R10 und R11 unabhängig ausgewählt sind aus H, CH3, CH2CH3, CH2CH2CH3, C(CH3)2;
R4 und R8 unabhängig ausgewählt sind aus CH2, CHCH3 und C(CH3) ;
R5 ausgewählt ist aus H, Methyl, Ethyl; und
R9 ausgewählt ist aus CH=CH2, CCH3=CH2 und CH=CHCH3.
17. Silicon-Hydrogel gemäß Anspruch 16, wobei das langsam reagierende hydrophile Monomer
ausgewählt ist aus dem Vinylpyrrolidon der Formel II oder IV und dem N-Vinylamid-Monomer
der Formel I und die Gesamtzahl von Kohlenstoffatomen in R1 und R2 4 oder weniger beträgt oder
wobei das langsam reagierende hydrophile Monomer ausgewählt ist aus einem Vinylpyrrolidon
der Formel III oder IV und R6 Methyl ist, R7 Wasserstoff ist, R9 CH=CH2 ist, R10 und R11 H sind oder
wobei das langsam reagierende hydrophile Monomer ausgewählt ist aus dem langsam reagierenden
hydrophilen Monomer ausgewählt aus Ethylenglycolvinylether (EGVE), Di(ethylenglycol)vinylether
(DEGVE), N-Vinylpyrrolidon (NVP), 1-Methyl-3-methylen-2-pyrrolidon, 1-Methyl-5-methylen-2-pyrrolidon,
5-Methyl-3-methylen-2-pyrrolidon, 1-Ethyl-5-methylen-2-pyrrolidon, N-Methyl-3-methylen-2-pyrrolidon,
5-Ethyl-3-methylen-2-pyrrolidon, 1-n-Propyl-3-methylen-2-pyrrolidon, 1-n-Propyl-5-methylen-2-pyrrolidon,
1-Isopropyl-3-methylen-2-pyrrolidon, 1-Isopropyl-5-methylen-2-pyrrolidon, N-Vinyl-N-methylacetamid
(VMA), N-Vinyl-N-ethylacetamid, N-Vinyl-N-ethylformamid, N-Vinylformamid, N-Vinylacetamid,
N-Vinylisopropylamid, Allylalkohol, N-Vinylcaprolactam, N-2-Hydroxyethylvinylcarbamat,
N-Carboxy-β-alanin-N-vinylester, N-Carboxyvinyl-β-alanin (VINAL), N-Carboxyvinyl-α-alanin
und Gemischen davon, gegebenenfalls
wobei das langsam reagierende hydrophile Monomer ausgewählt ist aus NVP, VMA und 1-Methyl-5-methylen-2-pyrrolidon,
gegebenenfalls wobei das langsam reagierende hydrophile Monomer NVP umfasst.
18. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei die siliconhaltige
Komponente wenigstens eine Hydroxygruppe umfasst.
19. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend wenigstens
ein Hydroxyalkylmonomer.
20. Silicon-Hydrogel gemäß Anspruch 19, wobei das Hydroxyalkylmonomer ausgewählt ist aus
einem Hydroxyalkyl(meth)acrylat- oder -(meth)acrylamid-Monomer der Formel VII und
einer Styrylverbindung der Formel VIII,
wobei R1 H oder Methyl ist,
X O oder NR16 ist, R16 ein H, C1- bis C4-Alkyl, das mit wenigstens einem OH weiter substituiert sein kann, ist, und
R17 ausgewählt ist aus mono- oder dihydroxysubstituiertem C2-C4-Alkyl und Poly(ethylenglycol) mit 1-10 Wiederholungseinheiten.
21. Silicon-Hydrogel gemäß Anspruch 20, wobei R1 H oder Methyl ist, X Sauerstoff ist und R17 ausgewählt ist aus mono- oder dihydroxysubstituiertem C2-C4-Alkyl und Poly(ethylenglycol) mit 1-10 oder 2-20 Wiederholungseinheiten oder
wobei das Hydroxyalkylmonomer ausgewählt ist aus 2-Hydroxyethylmethacrylat, 2-Hydroxyethylacrylat,
3-Hydroxypropyl(meth)acrylat, 2-Hydroxypropyl(meth)acrylat, 1-Hydroxypropyl-2-(meth)acrylat,
2-Hydroxy-2-methylpropyl(meth)acrylat, 3-Hydroxy-2,2-dimethylpropyl(meth)acrylat,
4-Hydroxybutyl(meth)acrylat, Glycerol(meth)acrylat, 2-Hydroxyethyl(meth)acrylamid,
Polyethylenglycolmonomethacrylat, Bis(2-hydroxyethyl)(meth)acrylamid, 2,3-Dihydroxypropyl(meth)acrylamid
und Gemischen davon, gegebenenfalls
wobei das Hydroxyalkylmonomer ausgewählt ist aus der Gruppe bestehend aus 2-Hydroxyethylmethacrylat,
Glycerolmethacrylat, 2-Hydroxypropylmethacrylat, Hydroxybutylmethacrylat, 3-Hydroxy-2,2-dimethylpropylmrethacrylat
und Gemischen davon, gegebenenfalls
wobei das Hydroxyalkylmonomer 2-Hydroxyethylmethacrylat, 3-Hydroxy-2,2-dimethylpropylmrethacrylat
Glycerolmethacrylat und Gemische, die sie umfassen, umfasst.
22. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das wenigstens eine
siliconhaltige Monomer monofunktionell ist und (a) eine reaktionsfähige Gruppe ausgewählt
aus (Meth)acrylaten, Styrylen, Amiden und Gemischen davon und (b) eine Polydialkylsiloxankette
umfasst und gegebenenfalls Fluor enthalten kann.
23. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei die siliconhaltige
Komponente ausgewählt ist aus einem Mono(meth)acryloxyalkylpolydialkylsiloxan-Monomer
der Formel IX und dem Styrylpolydialkylsiloxan-Monomer der Formel X:
wobei R12 H oder Methyl ist;
X O oder NR16 ist;
jedes R14 unabhängig ein C1- bis C4-Alkyl, das fluorsubstituiert sein kann, oder Phenyl ist;
R15 ein C1- bis C4-Alkyl ist;
R13 eine zweiwertige Alkylgruppe ist, die ferner mit einer Gruppe ausgewählt aus der
Gruppe bestehend aus Ethergruppen, Hydroxygruppen, Carbamatgruppen und Kombinationen
davon funktionalisiert sein kann;
a 3 bis 50 ist;
R16 ausgewählt ist aus H, C1-4, das mit einer oder mehreren Hydroxygruppen weiter substituiert
sein kann.
24. Silicon-Hydrogel gemäß Anspruch 23, wobei jedes R14 unabhängig ausgewählt ist aus Ethyl- und Methylgruppen, gegebenenfalls wobei alle
R14 Methyl sind, oder
wobei R12 und alle R14 Methyl sind oder
wobei wenigstens ein R14 3,3,3-Trifluorpropyl ist oder
wobei R13 ausgewählt ist aus C1-C6-Alkylengruppen, die mit Ether, Hydroxy und Kombinationen
davon substituiert sein können, oder
wobei R13 ausgewählt ist aus C1- oder C3-C6-Alkylengruppen, die mit Ether, Hydroxy und Kombinationen
davon substituiert sein können, oder
wobei a 5 bis 15 ist oder
wobei R16 H oder Methyl ist oder
wobei das Monomethacryloxyalkylpolydimethylsiloxanmethacrylat ausgewählt ist aus der
Gruppe bestehend aus Monomethacryloxypropyl-terminiertem Mono-n-butyl-terminiertem
Polydimethylsiloxan, Monomethacryloxypropyl-terminiertem Mono-n-methylterminiertem
Polydimethylsiloxan, Monomethacryloxypropyl-terminiertem Mono-n-butylterminiertem
Polydiethylsiloxan, Monomethacryloxypropyl-terminiertem Mono-n-methylterminiertem
Polydiethylsiloxae, N-(2,3-Dihydroxypropan)-N'-(propyl-tetra(dimethylsiloxy)dimethylbutylsilan)
acrylamid, α-(2-Hydroxy-1-methacryloxypropyloxypropyl)-ω-butyl-octamethylpentasiloxan
und Gemischen davon, gegebenenfalls
wobei das Monomethacryloxyalkylpolydimethylsiloxanmethacrylat ausgewählt ist aus der
Gruppe bestehend aus Monomethacryloxypropyl-terminiertem Mono-n-butyl-terminiertem
Polydimethylsiloxan, Monomethacryloxypropyl-terminiertem Mono-n-methylterminiertem
Polydimethylsiloxan, N-(2,3-Dihydroxypropan)-N'-(propyltetra(dimethylsiloxy)-dimethylbutylsilan)acrylamid
und Gemischen davon, gegebenenfalls
wobei das langsam reagierende hydrophile Monomer und das Hydroxymonomer ein Molverhältnis
von Hydroxygruppen zu dem langsam reagierenden hydrophilen Monomer von zwischen 0,15
und 0,4 bilden.
25. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend wenigstens
ein vernetzendes Monomer.
26. Silicon-Hydrogel gemäß einem der Ansprüche 18 bis 25, wobei das langsam reagierende
hydrophile Monomer ausgewählt ist aus N-Vinylpyrrolidon, N-Vinylacetamid, 1-Methyl-3-methylen-2-pyrrolidon,
1-Methyl-5-methylen-2-pyrrolidon, 5-Methyl-3-methylen-2-pyrrolidon und Gemischen davon.
27. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, das ferner einen Ausbreitungs-Kontaktwinkel
von weniger als 80° oder weniger als 70° aufweist.
28. Silicon-Hydrogel, gebildet aus dem Reaktionsgemisch gemäß Anspruch 1,
wobei wenigstens eine von der siliconhaltigen Komponente, den optionalen zusätzlichen
hydrophilen Komponenten oder beide wenigstens eine Hydroxygruppe umfassen und wobei
die langsam reagierende hydrophile Komponente und die siliconhaltige Komponente so
ausgewählt sind, dass sie ein Umwandlungsverhältnis bei 90 % Umwandlung von mehr als
10 oder wenigstens 20 oder wenigstens 30 oder wenigstens 90 aufweisen,
wobei das "Umwandlungsverhältnis bei 90 % Umwandlung" das Verhältnis der Konzentration
des langsam reagierenden hydrophilen Monomers zu der Konzentration des am langsamsten
reagierenden siliconhaltigen Monomers bei 90 % Umwandlung des am langsamsten reagierenden
siliconhaltigen Monomers ist.
29. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, gebildet aus einem Reaktionsgemisch
umfassend 37 bis 75 Gew.-% oder 37 bis 70 Gew.-% oder 39 bis 60 Gew.-% an dem wenigstens
einen langsam reagierenden hydrophilen Monomer mit einer kinetischen Halbwertszeit
des langsam reagierenden hydrophilen Monomers.
30. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, ferner umfassend von 5 bis
20 Gew.-% an wenigstens einem polaren Verdünnungsmittel bezogen auf alle Komponenten
in dem Reaktionsgemisch, gegebenenfalls
wobei das polare Verdünnungsmittel ausgewählt ist aus der Gruppe bestehend aus Carbonsäuren,
sekundären und tertiären Alkoholen.
31. Silicon-Hydrogel gemäß Anspruch 30, wobei das Verdünnungsmittel ferner wenigstens
polyhydrisches Coverdünnungsmittel umfasst, gegebenenfalls
wobei das polyhydrische Coverdünnungsmittel in einer Menge von zwischen 0,5 und 5
Gew.-%, bezogen auf alle Komponenten in dem Reaktionsgemisch, vorliegt oder
wobei das polyhydrische Coverdünnungsmittel ausgewählt ist aus der Gruppe bestehend
aus Glycerin, Borsäure, Borsäureglycerolestern, Polyalkylenglycolen und Gemischen
davon.
32. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Reaktionsgemisch
ferner wenigstens einen langsam reagierenden Vernetzer und wenigstens einen schnell
reagierenden Vernetzer umfasst, gegebenenfalls
wobei die langsam reagierenden Vernetzer nur vinylreaktive Funktionalität aufweisen
und die schnell reagierenden Vernetzer nur (meth)acrylatreaktive Funktionalität aufweisen
oder
wobei der langsam reagierende Vernetzer TAC (Triallylcyanurat) umfasst und der schnell
reagierende Vernetzer ausgewählt ist aus der Gruppe bestehend aus EDGMA (Ethylenglycoldimethacrylat),
TEGDMA (Tetraethylenglycoldimethacrylat) und Gemischen davon.
33. Silicon-Hydrogel gemäß einem der vorstehenden Ansprüche, wobei das Reaktionsgemisch
frei von zusätzlichen hydrophilen Komponenten ist.
34. Silicon-Hydrogel gemäß Anspruch 30, wobei das Reaktionsgemisch weniger als 5 % an
Zwischenprodukt-reagierenden hydrophilen Komponenten umfasst.
35. Silicon-Hydrogel gemäß Anspruch 32, wobei der wenigstens eine langsam reagierende
Vernetzer und wenigstens ein schnell reagierender Vernetzer in dem Reaktionsgemisch
jeweils in Mengen von zwischen 0,7 und 6,0 mmol/100 g oder 0,7 bis 4,0 mmol/100 g
der polymerisierbaren Komponenten vorhanden sind oder
wobei die langsam reagierenden Vernetzer nur vinylreaktive Funktionalität aufweisen
und die schnell reagierenden Vernetzer nur (meth)acrylatreaktive Funktionalität aufweisen
und wobei alle Vernetzer in einer Menge von weniger als 2 Gew.-% vorhanden sind oder
wobei die Menge aller Vernetzer in dem reaktionsfähigen Gemisch zwischen 0,10 % und
1,0 % oder zwischen 0,10 und 2 %, ohne Berücksichtigung von Verdünnungsmittel, beträgt.
36. Verfahren zur Herstellung des Silicon-Hydrogels gemäß einem der vorstehenden Ansprüche,
umfassend Lichthärten des Reaktionsgemischs, wobei das Lichthärten innerhalb von 30
Minuten oder weniger abgeschlossen ist.
1. Hydrogel de silicone formé d'un mélange de réaction comprenant 30 à 75 % en poids
d'au moins un monomère hydrophile à réaction lente ayant une demi-vie cinétique de
monomère hydrophile à réaction lente ;
au moins un composant contenant du silicone ayant une demi-vie cinétique de composant
contenant du silicone, qui peut être facultativement substitué par au moins un groupe
contenant hydroxyle ;
au moins un photo-initiateur à lumière visible ;
au moins un composant contenant hydroxyle choisi parmi lesdits composants contenant
du silicone substitué par au moins un groupe hydroxyle, au moins un monomère d'hydroxyalkyle,
et des mélanges de ceux-ci ; et
au moins un composé absorbant les UV,
dans lequel le rapport de ladite demi-vie de composant hydrophile à réaction lente
à ladite demi-vie de composant contenant du silicone est au moins 2, et
dans lequel la polymérisation du mélange de réaction est initiée en utilisant de la
lumière visible.
2. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit rapport de demi-vies cinétiques est au moins 3, ou est au moins 5.
3. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre un Dk d'au moins 80, ou au moins 85, dans lequel Dk est mesuré selon le procédé
décrit dans la section « Perméabilité à l'oxygène (Dk) » de la description détaillée.
4. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre un % de trouble inférieur à 70 %, ou inférieur à 50 %, ou inférieur à 10
%, dans lequel le % de trouble est mesuré selon le procédé décrit dans la section
« Mesure de trouble » du « Paramètre de solubilité de trouble » de la description
détaillée.
5. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre une teneur en eau d'au moins 55 %, ou au moins 60 %.
6. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre un module inférieur à 150 psi, ou 100 psi ou moins, dans lequel le module
est mesuré selon le procédé décrit dans la section « Module » de la description détaillée.
7. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit au moins un composé absorbant les UV est réactif.
8. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit au moins un composé absorbant les UV est choisi parmi des benzotriazoles, ou
dans lequel ledit au moins un composé absorbant les UV est choisi dans le groupe constitué
de 2-(2'-hydroxyphényl)benzotriazoles, 2-hydroxybenzophénones, 2-hydroxyphényltriazines,
oxanilides, cyanoacrylates, salicylates et 4-hydroxybenzoates réactifs, ou
dans lequel ledit au moins un composé absorbant les UV est choisi dans le groupe constitué
du 2-(2'-hydroxy-5-méthacrylyloxyéthylphényl)-2H-benzotriazole, de dérivés 5-vinyliques
et 5-isopropényliques de 2-(2,4-dihydroxyphényl)-2H-benzotriazole et 4-acrylates ou
4-méthacrylates de 2-(2,4-dihydroxyphényl)-2H-benzotriazole ou de 2-(2,4-dihydroxyphényl)-1,3-2H-dibenzotriazole,
et des mélanges de ceux-ci.
9. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
entre 0,5 et 4 % en poids, facultativement entre 1 % en poids et 2 % en poids, d'au
moins un absorbeur UV.
10. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit mélange de réaction est exempt de diluant.
11. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit mélange de réaction est exempt de TRIS (3-méthacryloxypropyltris(triméthylsiloxy)silane)
.
12. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit mélange de réaction est exempt de silicone contenant des macromères ou des prépolymères.
13. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit monomère hydrophile à réaction lente comprend un groupe réactif choisi dans
le groupe constitué de (méth)acrylamides, vinyles, allyles et des combinaisons de
ceux-ci et ledit composant contenant du silicone comprend un groupe réactif choisi
dans le groupe constitué de (méth)acrylates, styryles, amides et des mélanges de ceux-ci,
facultativement
dans lequel ledit monomère hydrophile à réaction lente comprend un groupe réactif
choisi dans le groupe constitué de vinyles, allyles et des combinaisons de ceux-ci
et ledit composant contenant du silicone comprend un groupe réactif choisi dans le
groupe constitué de (méth)acrylates, styryles, amides et des mélanges de ceux-ci.
14. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit monomère hydrophile à réaction lente comprend un groupe réactif choisi dans
le groupe constitué de N-vinylamides, O-vinylcarbamates, O-vinylcarbonates, N-vinylcarbamates,
éthers O-vinyliques, O-2-propényle, dans lequel les groupes vinyle ou allyle peuvent
en outre être substitués par un groupe méthyle.
15. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit monomère hydrophile à réaction lente comprend au moins un groupe hydrophile
choisi dans le groupe constitué d'hydroxyles, amines, éthers, amides, groupes ammonium,
acide carboxylique, carbamates et des combinaisons de ceux-ci, facultativement
dans lequel ledit monomère hydrophile à réaction lente comprend au moins un groupe
hydrophile choisi dans le groupe constitué d'hydroxyles, éthers, amides, acide carboxylique
et des combinaisons de ceux-ci.
16. Hydrogel de silicone selon les revendications 1 à 12, dans lequel ledit monomère hydrophile
à réaction lente est choisi parmi un monomère N-vinylamide de formule I, une vinylpyrrolidone
de formule II à IV, une N-vinylpipéridone de formule V :
dans lequel R est H ou méthyle ;
R1, R2, R3, R6, R7, R10 et R11 sont indépendamment choisis parmi H, CH3, CH2CH3, CH2CH2CH3, C(CH3)2 ;
R4 et R8 sont indépendamment choisis parmi CH2, CHCH3 et C (CH3) ;
R5 est choisi parmi H, méthyle, éthyle ; et
R9 est choisi parmi CH=CH2, CCH3=CH2, et CH=CHCH3.
17. Hydrogel de silicone selon la revendication 16, dans lequel le monomère hydrophile
à réaction lente est choisi parmi la vinylpyrrolidone de formule II ou IV ou le monomère
N-vinylamide de formule I, et le nombre total d'atomes de carbone dans R1 et R2 est 4 ou moins, ou dans lequel le monomère hydrophile à réaction lente est choisi
parmi une vinylpyrrolidone de formule III ou IV et R6 est méthyle, R7 est hydrogène, R9 est CH=CH2, R10 et R11 sont H, ou
dans lequel le monomère hydrophile à réaction lente est choisi parmi les éther vinylique
d'éthylène glycol (EGVE), éther vinylique de di(éthylène glycol) (DEGVE), N-vinylpyrrolidone
(NVP), 1-méthyl-3-méthylène-2-pyrrolidone, 1-méthyl-5-méthylène-2-pyrrolidone, 5-méthyl-3-méthylène-2-pyrrolidone
; 1-éthyl-5-méthylène-2-pyrrolidone, N-méthyl-3-méthylène-2-pyrrolidone, 5-éthyl-3-méthylène-2-pyrrolidone,
1-n-propyl-3-méthylène-2-pyrrolidone, 1-n-propyl-5-méthylène-2-pyrrolidone, 1-isopropyl-3-méthylène-2-pyrrolidone,
1-isopropyl-5-méthylène-2-pyrrolidone, N-vinyl-N-méthylacétamide (VMA), N-vinyl-N-éthylacétamide,
N-vinyl-N-éthylformamide, N-vinylformamide, N-vinylacétamide, N-vinylisopropylamide,
alcool allylique, N-vinylcaprolactame, N-2-hydroxyéthylvinylcarbamate, N-carboxy-β-alanine
ester N-vinylique ; N-carboxyvinyl-β-alanine (VINAL), N-carboxyvinyl-α-alanine et
des mélanges de ceux-ci, facultativement
dans lequel le monomère hydrophile à réaction lente est choisi parmi NVP, VMA et 1-méthyl-5-méthylène-2-pyrrolidone,
facultativement dans lequel le monomère hydrophile à réaction lente comprend NVP.
18. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit composant contenant du silicone comprend au moins un groupe hydroxyle.
19. Hydrogel de silicone selon l'une quelconque des revendications précédentes comprenant
en outre au moins un monomère hydroxyalkyle.
20. Hydrogel de silicone selon la revendication 19, dans lequel ledit monomère hydroxyalkyle
est choisi parmi un monomère de (méth)acrylate d'hydroxyalkyle ou (méth)acrylamide
de formule VII ou un composé de styryle de formule VIII
dans lequel R1 est H ou méthyle,
X est O ou NR16, R16 est H, alkyle en C1 à C4, qui peut en outre être substitué par au moins un OH, et
R17 est choisi parmi alkyle en C2-C4 substitué par mono ou dihydroxy, et poly(éthylène glycol) ayant 1 à 10 motifs de
répétition.
21. Hydrogel de silicone selon la revendication 20, dans lequel R1 est H ou méthyle, X est oxygène et R17 est choisi parmi alkyle en C2-C4 substitué par mono ou dihydroxy, et poly(éthylène glycol) ayant 1 à 10, ou 2 à 20,
motifs de répétition, ou
dans lequel ledit monomère d'hydroxyalkyle est choisi parmi les méthacrylate de 2-hydroxyéthyle,
acrylate de 2-hydroxyéthyle, (méth)acrylate de 3-hydroxypropyle, (méth)acrylate de
2-hydroxypropyle, 2-(méth)acrylate de 1-hydroxypropyle, (méth)acrylate de 2-hydroxy-2-méthyl-propyle,
(méth)acrylate de 3-hydroxy-2,2-diméthyl-propyle, (méth)acrylate de 4-hydroxybutyle,
(méth)acrylate de glycérol, 2-hydroxyéthyl-(méth)acrylamide, monométhacrylate de polyéthylèneglycol,
bis-(2-hydroxyéthyl)-(méth)acrylamide, 2,3-dihydroxypropyl-(méth)acrylamide, et des
mélanges de ceux-ci, facultativement dans lequel ledit monomère hydroxyalkyle est
choisi dans le groupe constitué des méthacrylate de 2-hydroxyéthyle, méthacrylate
de glycérol, méthacrylate de 2-hydroxypropyle, méthacrylate d'hydroxybutyle, méthacrylate
de 3-hydroxy-2,2-diméthyl-propyle, et des mélanges de ceux-ci, facultativement
dans lequel ledit monomère hydroxyalkyle comprend le méthacrylate de 2-hydroxyéthyle,
le méthacrylate de 3-hydroxy-2,2-diméthyl-propyle, le méthacrylate de glycérol et
des mélanges comprenant ceux-ci.
22. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
l'au moins un monomère contenant du silicone est monofonctionnel et comprend (a) un
groupe réactif choisi parmi des (méth)acrylates, des styryles, des amides et des mélanges
de ceux-ci et (b) une chaîne de polydialkylsiloxane et peut facultativement contenir
du fluor.
23. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit composant contenant du silicone est choisi parmi un monomère de mono(méth)acryloxyalkyl-polydialkylsiloxane
de formule IX ou le monomère de styryl-polydialkylsiloxane de formule X :
dans lequel R12 est H ou méthyle ;
X est O ou NR16 ;
chaque R14 est indépendamment un alkyle en C1 à C4 qui peut être substitué par fluor, ou phényle ;
R15 est un alkyle en C1 à C4 ;
R13 est un groupe alkyle divalent, qui peut en outre être fonctionnalisé avec un groupe
choisi dans le groupe constitué de groupes éther, groupes hydroxyle, groupes carbamate
et des combinaisons de ceux-ci ;
a est 3 à 50 ;
R16 est choisi parmi H, C1-4, qui peut en outre être substitué par un ou plusieurs groupes
hydroxyle.
24. Hydrogel de silicone selon la revendication 23, dans lequel chaque R14 est indépendamment choisi parmi des groupes éthyle et méthyle, facultativement dans
lequel tous les R14 sont méthyle, ou
dans lequel R12 et chaque R14 sont méthyle, ou
dans lequel au moins un R14 est 3,3,3-trifluoropropyle, ou
dans lequel R13 est choisi parmi des groupes alkylène en C1-C6 qui peuvent être substitués par éther,
hydroxyle et des combinaisons de ceux-ci, ou
dans lequel R13 est choisi parmi des groupes alkylène en C1 ou C3-C6 qui peuvent être substitués
par éther, hydroxyle et des combinaisons de ceux-ci, ou
dans lequel a est 5 à 15, ou
dans lequel R16 est H ou méthyle, ou
dans lequel ledit méthacrylate de monométhacryloxyalkylpolydiméthylsiloxane est choisi
dans le groupe constitué de polydiméthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-butyle, polydiméthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-méthyle, polydiéthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-butyle, polydiéthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-méthyle, N-(2,3-dihydroxypropane)-N'-(propyl-tétra(diméthylsiloxy)diméthylbutylsilane)acrylamide,
α-(2-hydroxy-1-méthacryloxypropyloxypropyl)-ω-butyl-octaméthylpentasiloxane, et des
mélanges de ceux-ci, facultativement
dans lequel ledit méthacrylate de monométhacryloxyalkylpolydiméthylsiloxane est choisi
dans le groupe constitué de polydiméthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-butyle, polydiméthylsiloxane terminé par monométhacryloxypropyle,
terminé par mono-n-méthyle, N-(2,3-dihydroxypropane)-N'-(propyl-tétra(diméthylsiloxy)diméthylbutylsilane)acrylamide,
et des mélanges de ceux-ci, facultativement dans lequel ledit monomère hydrophile
à réaction lente et ledit monomère hydroxyle forment un rapport molaire des groupes
hydroxyle au monomère hydrophile à réaction lente compris entre 0,15 et 0,4.
25. Hydrogel de silicone selon l'une quelconque des revendications précédentes comprenant
en outre au moins un monomère de réticulation.
26. Hydrogel de silicone selon l'une quelconque des revendications 18 à 25, dans lequel
ledit monomère hydrophile à réaction lente est choisi parmi N-vinylpyrrolidone, N-vinylacétamide,
1-méthyl-3-méthylène-2-pyrrolidone, 1-méthyl-5-méthylène-2-pyrrolidone, 5-méthyl-3-méthylène-2-pyrrolidone,
et des mélanges de ceux-ci.
27. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre un angle de contact d'avancement inférieur à 80°, ou inférieur à 70°.
28. Hydrogel de silicone formé à partir du mélange de réaction selon la revendication
1, dans lequel au moins l'un desdits composant contenant du silicone, composants hydrophiles
supplémentaires facultatifs, ou les deux, comprend au moins un groupe hydroxyle et
dans lequel ledit composant hydrophile à réaction lente et ledit composant contenant
du silicone sont choisis de façon à présenter un rapport de conversion à 90 % de conversion
de plus de 10, ou au moins 20, ou au moins 30, ou au moins 90,
dans lequel le « rapport de conversion à 90 % de conversion » est le rapport de la
concentration du monomère hydrophile à réaction lente à la concentration du monomère
contenant du silicone à réaction lente à 90 % de conversion du monomère contenant
du silicone à réaction la plus lente.
29. Hydrogel de silicone selon l'une quelconque des revendications précédentes, formé
à partir d'un mélange de réaction comprenant 37 à 75 % en poids, ou 37 à 70 % en poids,
ou 39 à 60 % en poids, de l'au moins un monomère hydrophile à réaction lente ayant
une demi-vie cinétique de monomère hydrophile à réaction lente.
30. Hydrogel de silicone selon l'une quelconque des revendications précédentes, comprenant
en outre de 5 à 20 % en poids d'au moins un diluant polaire, sur la base de tous les
composants dans le mélange de réaction, facultativement dans lequel ledit diluant
polaire est choisi dans le groupe constitué d'acides carboxyliques, d'alcools secondaires
et tertiaires.
31. Hydrogel de silicone selon la revendication 30, dans lequel ledit diluant comprend
en outre au moins un codiluant polyhydrique, facultativement dans lequel ledit codiluant
polyhydrique est présent en une quantité comprise entre 0,5 et 5 % en poids, sur la
base de tous les composants dans le mélange de réaction, ou
dans lequel ledit codiluant polyhydrique est choisi dans le groupe constitué de la
glycérine, l'acide borique, des esters de glycérol d'acide borique, des polyalkylène
glycols et des mélanges de ceux-ci.
32. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit mélange de réaction comprend en outre au moins un agent de réticulation à réaction
lente et au moins un agent de réticulation à réaction rapide, facultativement
dans lequel lesdits agents de réticulation à réaction lente ont uniquement une fonctionnalité
réactive vinylique et lesdits agents de réticulation à réaction rapide ont uniquement
une fonctionnalité réactive (méth)acrylate, ou
dans lequel ledit agent de réticulation à réaction lente comprend TAC (cyanurate de
triallyle) et ledit agent de réticulation à réaction rapide est choisi dans le groupe
constitué d'EDGMA (diméthacrylate d'éthylèneglycol), TEGDMA (diméthacrylate de tétraéthylèneglycol)
et des mélanges de ceux-ci.
33. Hydrogel de silicone selon l'une quelconque des revendications précédentes, dans lequel
ledit mélange de réaction est exempt de composants hydrophiles supplémentaires.
34. Hydrogel de silicone selon la revendication 30, dans lequel ledit mélange de réaction
comprend moins de 5 % de composants hydrophiles réactifs intermédiaires.
35. Hydrogel de silicone selon la revendication 32, dans lequel lesdits au moins un agent
de réticulation à réaction lente et au moins un agent de réticulation à réaction rapide
sont chacun présents dans ledit mélange de réaction dans des quantités comprises entre
0,7 et 6,0 mmol/100 g, ou 0,7 et 4,0 mmol/100 g, de composants polymérisables, ou
dans lequel lesdits agents de réticulation à réaction lente ont uniquement une fonctionnalité
réactive vinylique et lesdits agents de réticulation à réaction rapide ont uniquement
une fonctionnalité réactive (méth)acrylate et dans lequel tous les agents de réticulation
sont présents en une quantité inférieure à 2 % en poids, ou
dans lequel la quantité de tous les agents de réticulation dans le mélange de réactifs
est comprise entre 0,10 % et 1,0 %, ou entre 0,10 et 2 %, en excluant le diluant.
36. Procédé de formation de l'hydrogel de silicone selon l'une quelconque des revendications
précédentes, comprenant le photodurcissement du mélange de réaction, dans lequel ledit
photodurcissement est terminé en 30 minutes ou moins.