FIELD OF THE INVENTION
[0001] This invention relates to the formation of silicone core-shell or gel particles that
can be used encapsulate actives.
BACKGROUND OF THE INVENTION
[0002] In personal care formulations it has become desirable to use low viscosity silicones
to impart a number of benefits to the formulation. However, because of the addition
of the low viscosity silicone, there must be additionally added a thickener to the
personal care formulation. Certain silicone polymers have found utility as the thickening
agent because they can be used in the quantities necessary to thicken the composition
without degrading the properties of the personal care formulation. Typically, the
silicone polymer and low viscosity silicone are combined to form a paste. This paste
can then be used in the personal care formulation. Such silicone polymers are described
in
U.S. Patent No. 4,987,169 to Kuwata et al.,
U.S. Patent No. 5,760,116 to Kilgour et al.,
U.S. Patent No. 5,811,487 to Schulz, Jr. et al. and
U.S. Patent No. 5,889,108 to Zhang and
U.S. Patent No. 6,238,657 to Lin et al.
[0003] This invention relates to the formation of silicone core-shell or gel particles that
can be used to encapsulate actives. The resulting encapsulated actives can be used
in personal care formulations.
SUMMARY OF THE INVENTION
[0004] This invention relates to the formation of silicone core-shell or gel particles that
can be used encapsulate actives. The silicone particles are produced by emulsifying
and reacting a composition comprising
[0005] (I) a siloxane oligomer or polymer having units of

where each Y is independently selected from
R': an alkyl group with 1 to 30 C atoms, an aryl group having 6 to 15 carbon atoms,
an alkaryl group having 6 to 15 carbon atoms, and an aralkyl group having 6 to 15
carbon atoms;
Z: a reactive group selected from epoxy-functional groups or chlorohydrin functional
groups;
Z' : a functional group that reacts with epoxy-functional groups or chlorohydrin functional
groups (i.e. amine, hydroxyl);
F: a functional group other than Z or Z', and
O (oxygen radicals);
[0006] with the proviso that at least 50 mol% of the Y groups in the siloxane are R', preferably
methyl and there are at least two Z and/or Z' groups in the siloxane;
[0007] (II) a crosslinker wherein said crosslinker contains Z and/or Z' groups with the
proviso that when Y in siloxane (I) contains Z groups, the crosslinker contains Z'
groups; when Y in siloxane (I) contains Z' groups, the crosslinker contains Z groups;
and when Y in siloxane (I) contains Z and Z' groups, the crosslinker contains Z groups,
Z' groups or both;
[0008] (III) at least one emulsion liquid;
[0009] (IV) a surfactant; and
[0010] (V) and active ingredient.
[0011] The core-shell and gel particles produced by this method are useful in the encapsulation
of actives. The encapsulated actives are useful in personal care products, textiles,
auto care products, and laundry products for the delivery of active ingredients.
DETAILED DESCRIPTION OF THE INVENTION
[0012] This invention pertains to silicone core-shell or gel particles. The silicone particles
are produced by emulsifying and reacting a composition comprising
[0013] (I) a siloxane oligomer or polymer having units of

where each Y is independently selected from
R': an alkyl group with 1 to 30 C atoms, an aryl group having 6 to 15 carbon atoms,
an alkaryl group having 6 to 15 carbon atoms, and an aralkyl group having 6 to 15
carbon atoms;
Z: a reactive group selected from epoxy-functional groups or chlorohydrin functional
groups;
Z': a functional group that reacts with epoxy-functional groups or chlorohydrin functional
groups (i.e. amine, hydroxyl);
F: a functional group other than Z or Z', and
O (oxygen radicals);
[0014] with the proviso that at least 50 mol% of the Y groups in the siloxane are R', preferably
methyl and there are at least two Z and/or Z' groups in the siloxane;
[0015] (II) a crosslinker wherein said crosslinker contains Z and/or Z' groups with the
proviso that when Y in siloxane (I) contains Z groups, the crosslinker contains Z'
groups; when Y in siloxane (I) contains Z' groups, the crosslinker contains Z groups;
and when Y in siloxane (I) contains Z and Z' groups, the crosslinker contains Z groups,
Z' groups or both;
[0016] (III) at least one emulsion liquid;
[0017] (IV) a surfactant; and
[0018] (V) an active ingredient.
[0019] Component (I) is a siloxane oligomer or polymer having units of

where Y independently is
R' is selected from the group consisting of an alkyl group with 1 to 30 C atoms, an
aryl group having 6 to 15 carbon atoms, an alkaryl group having 6 to 15 carbon atoms,
and an aralkyl group having 6 to 15 carbon atoms;
Z is selected from epoxy-functional groups, chlorohydrin functional groups, or mixtures
thereof
Z' is a functional group that react with epoxy-functional groups or chlorohydrin functional
groups (i.e. amine, hydroxyl),
F is a functional group other than Z or Z', and
O (oxygen radicals);
with the with the proviso that at least 50 mol% of the Y groups in the siloxane are
R', preferably methyl and there are at least two Z and/or Z' groups in the siloxane.
[0020] Siloxane (I) can be comprised of Y
3SiO- units, Y
2SiO
2/2- units, YSiO
3/2- units and SiO
4/2 units wherein Y is as defined above. Preferable siloxane (I) primarily comprises
Y
2SiO
2/2- units.
[0021] R' groups may be exemplified by, but not limited to, methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, and phenyl, preferably methyl.
[0022] Z groups may be exemplified by, but not limited to epoxy groups and chlorohydrin
groups and mixtures thereof.
[0023] Z' groups may be exemplified by, but not limited to, amine groups and hydroxyl groups.
[0024] F groups may be exemplified by, but not limited to, polyether groups, quaternary
ammonium salt groups, monohydroxy alcohol groups, polyhydroxy alcohol groups, carbohydrate
groups, acrylate groups, ester groups, amide groups, carbonate groups, carboxylate
groups, sulfonate groups, sulfate groups, halogen groups, trialkoxysilyl groups, the
following functional groups wherein R is the same as R' defined above:

and mixtures thereof.
[0025] In Siloxane (I), there must be at least two reactive groups selected from Z and/or
Z'. Preferably the reactive group is Z' and even more preferable the reactive group
is an amine functional group.
[0026] Amine functional silicones that may be useful typically are of the formula

wherein R' is independently an alkyl group with 1 to 30 C atoms, an aryl group having
6 to 15 carbon atoms, an alkaryl group having 6 to 15 carbon atoms, and an aralkyl
group having 6 to 15 carbon atoms with the proviso that at least 50% of the total
number of R' groups are methyl; Q is an amine functional substituent of the formula
-R"A wherein R" is a divalent alkylene radical having 3 to 6 carbons and A is a monovalent
radical selected from the group consisting of -NR‴, and -NR"'(CH
2)
bNR
2"'; wherein R"' denotes hydrogen or an alkyl group having 1 to 4 carbons, and b is
a positive integer having a value of from 2 to 6; z has a value of 0 to 1; x has an
average value of 5 to 3000; y has an average value of 0 to 3000 when z is 1, and y
has an average value of 1 to 3000 when z is 0.
[0027] R" groups may be exemplified by, but not limited to, trimethylene, tetramethylene,
pentamethylene, -CH
2CH(CH
3)CH
2-, and -CH
2CH
2CH(CH
3)CH
2- radicals. Preferable R" is a trimethylene or an alkyl substituted trimethylene radical
such as -CH
2CH(CH
3)CH
2-.
[0028] R‴ groups may be exemplified by, but not limited to methyl, ethyl, propyl, isoproplyl,
butyl, and isobutyl.
[0029] A may be exemplified by, but not limited to, -NH
2, alkyl substituted amine radicals such as -NHCH
3, -NHCH
2CH
2CH
2CH
3, and aminoalkyl substituted amine radicals such as -NHCH
2CH
2NH
2, NH(CH
2)
6NH
2 and -NHCH
2CH
2CH
2N(CH
3)
2.
[0030] In the above amine functional silicone formula when z is 0, the silicon has only
pendent amine functional substituents; when z is 1, the amine functional substituents
may be terminal or both terminal and pendant. In the above amine functional silicone,
x is preferably from 5 to 500 and y is preferably from 0 to 100 when z is 1 and from
1 to 100 when z is 0. Most preferably, x + y is in the range of 15 to 1000.
[0031] The amine content (the number of amine functional groups in the molecule of the amine
functional silicone) is generally expressed as mole percent amine. Mole percent amine
is determined according to the relationship y/DP x 100, where y is the value of integer
y in the above formula for the amine functional silicone and DP (Degree of Polymerization)
is x + y + 2 which indicates the chain length of the amine functional silicone.
[0032] Amine functional silicones useful herein are well known in the art and are commercially
available.
[0033] Siloxane (I) may also be an epoxy functional silicone. Epoxy functional silicones
of the general structure shown below can be used, in which subscript a represents
an integer of one or more.

[0034] Epoxy functional silicones are well known in the art and available commercially.
Such silicones have a viscosity ranging from 1 to 200 centistoke (mm
2/s) and molecular weights of 300-6,000.
[0035] During the emulsification siloxane (I) is reacted with a crosslinker (II) wherein
said crosslinker (II) contains Z and/or Z' groups with the proviso that when Y in
siloxane (I) contains Z groups, the crosslinker contains Z' groups; when Y in siloxane
(I) contains Z' groups, the crosslinker contains Z groups; and when Y in siloxane
(I) contains Z and Z' groups, the crosslinker contains Z groups, Z' groups or both.
In addition to Z and/or Z' groups the crosslinker can contain functional groups, F,
as described above.
[0036] The crosslinker (II) can be organic compounds such as organic amines, organic epoxides
or siloxanes of the general formula provided for siloxane (I), above. The amount of
crosslinker (II) will depend on the amount of reactive sites in the either Z and/or
Z' groups in siloxane (I) and the molecular weight of siloxane (I) (i.e.
-NHCH
2CH(CH
3)CH
2NHCH
2CH
2NH
2 groups contains three reactive sites). One skilled in the art will be able to readily
calculate the amount of crosslinker needed to ensure partial or complete reaction
between the Z and Z' groups. Typically the ratio of reactive sites in the Z to Z'
groups is from 0.1:1 to 1.5:1, preferably 0.2:1 to 0.5:1, more preferably 0.25:1 to
0.35:1.
[0037] Organic epoxides containing at least two epoxy groups suitable for use herein include
ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene
glycol diglycidyl ether, glycerine diglycidyl ether, triglycidyl ether, propylene
glycol diglycidyl ether, and butanediol diglycidyl ether; 1,2,3,4-diepoxybutane; 1,2,4,5-diepoxypentane;
1,2,5,6-diepoxyhexane; 1,2,7,8-diepoxyoctane; 1,3-divinylbenzene diepoxide; 1,4-divinylbenzene
diepoxide; 4,4'-isopropylidene diphenol diglycidyl ether, and hydroquinone diglycidyl
ether. Other polyglycidyl ethers of alkane polyols, polyglycidyl ethers of poly(alkylene
glycols), diepoxy alkanes, diepoxy aralkanes, and polyphenol polyglycidyl ethers,
can also be used herein. Alternatively chlorohydrins may be used in place of or in
conjunction with the epoxides.
[0038] Two especially preferred organic epoxides containing at least two epoxy groups are
shown below, in which n is a positive integer determining the molecular weight of
the epoxide.

[0039] Organic amine compounds useful herein include ethane semicarbazole, acetaldehydeammonia,
acetamide, dichloroacetamide, thioacetarnide, acetamidine, o-aminoacetophenone, acrylamide,
adalin, adipamide, allanturic acid, ethyl ester of allophanic acid, allylamine, ammelide,
tert-amylamine, aniline, n-benzohydryl, 2,4-dibromo-6-nitroaniline, o-fluoroaniline,
p-nitrosoaniline, ar-pentachloroaniline, p,p'-thiodianiline, anisamide, m-anisidine,
9,10-anthradiamine, anthranilaldehyde, methyl ester of anthranilic acid, 3-nitroanthranilic
acid, anthranilonitrile, 2-amino-l-hydroxyanthraquinone, arsanilic acid, L-aspartic
acid, p-aminoazobenzene, 5,5-diallylbarbituric acid, 5 (2 furfurylidene)-2 thiobarbituric
acid, benzalhydrazine, benzamidoxime, benzamidine, benzenepentamine, benzenesulfonamide,
3-ethoxybenzidine, benzidine sulfone, benzocaine, p-aminobenzohydrol, benzohydrazide,
3-amino-5-nitrobenzoic acid, o-sulfamylbenzoic acid, 2,2'-diaminobenzophenone, biguanide,
acetylbiuret, bomylamine, 2-aminobutanol, cadaverine, 3-aminocamphor, dithiocarbamic
acid, thiolcarbamic acid-ethyl ester, thionocarbamic acidethyl ester, thiocarbanilide,
1,5-diphenylearbohydrazide, m-aminocinnamic acid, 3-amino-o-cresol, crotonamide, cyanamide,
cyclohexylamine, L-cysteine, diethylenetriamine, ethoxyamine, formamide, formohydrazide,
Dfructosamine, guanidine, p-bromophenylhydrazine, piperazine, o-nitrophenylhydrazine,
lactamide, nicotinamide, ethyloxamate, oxamide, pararosaniline, 2-phenanthrylamine,
2-nitrophenetidine, p-aminothiophenol, 2-aminopyridine, 4-aminoquinoline, thiosemicarbazide,
sulfanilamine, tetradecylamine, 3-thiophenesulfonamide, thiophenine, α,α,α-trifluoro-m-toluidine,
2-bromo-5-nitro-p-toluidine, urea, allylurea, allylthiourea, ethylideneurea, nitrourea,
p-phenethylurea, vinylamine, sulfaguanidine, dimethylgallium amide, and aminophenylmercuric
acetate.
[0040] Preferably the organic amine is selected from ammonia, diethylene triamine, ethylene
diamine, methane diamine, m-phenylene diamine, methylene dianiline, benzohydrazide,
guanidine, benzidene sulfone, thioacetamide, piperazine,
p-amino benzoic acid, thiosemicarbizide, allanturic acid,
p,
p'-thiodianiline, p-bromophenyl hydrazine, benzene pentamine, and N,N'-dimethyl ethylene
diamine.
[0041] If desired, crosslinkers (II) that contain a single Z or Z' group can be included
as an additional component, in order to control the cross link density and the overall
molecular weight of the silicone particle.
[0042] Functional groups such as polyether groups, quaternary ammonium salt groups, monohydroxy
alcohol groups, polyhydroxy alcohol groups, carbohydrate groups, acrylate groups,
ester groups, amide groups, carbonate groups, carboxylate groups, sulfonate groups,
sulfate groups, halogen groups, trialkoxysilyl groups, or mixtures thereof, can be
present in the silicone particle. Such functional groups may be present in the silicone
particle by using an emulsion component that contains the functional group, using
a siloxane (I) and/or crosslinker (II) that contains the functional group, reacting
the functional group into the silicone particle during or following emulsification,
and/or blending a component containing a functional group into the emulsion.
[0043] The amount of siloxane (I) and crosslinker (II) will depend on the amount of silicone
particles desired. Typically the amount of particles is from 0.1 to 80 wt. % based
on the total weight of the emulsion, preferably 10 to 80 wt.%, more preferably 40
to 60 wt. %.
[0044] The reaction between siloxane (I) and crosslinker (II) to produce the silicone particles
is carried out while emulsifying. There should be at least one emulsion liquid (III)
present. When there is only one emulsion liquid present that liquid forms one phase
of the emulsion while the particles form the second phase of the emulsion. When there
are two emulsion liquids present the silicone particles are typically suspended in
one of the liquids and form one phase of the emulsion while the other liquid forms
the other phase. Typically water is used as the emulsion liquid with the water forming
the external phase of the emulsion and the silicone particles forming the internal
phase of the emulsion.
[0045] The emulsion liquids can be chosen from, but not limited to, water, silicone fluids,
polar organic compounds, and non-polar organic compounds, preferably water. The emulsion
liquid is added in an amount of from 1 to 99.8 wt. % based on the total weight of
the emulsion, preferably 10 to 80 wt. %, more preferably 35 to 45 wt. %. A mixture
of liquids can be used to form a single phase so long as the liquids are miscible
and form an essentially homogeneous mixture.
[0046] Silicone fluids may be exemplified by, but not limited to, methyl siloxanes and alkyl
and/or aryl siloxanes containing functional groups wherein the functional groups do
not react with or substantially change the reaction between Z and Z'. Preferred are
volatile methyl siloxanes (VMS). VMS compounds correspond to the average unit formula
(CH
3)
jSiO(
4-j)
/2. in which j has an average value of 2 to 3. The VMS compounds contain siloxane units
joined by Si-O-Si bonds. Representative siloxane units are monofunctional "M" units:
(CH
3)
3SiO
1/2 and difunctional "D" units: (CH
3)
2SiO
2/2. The presence of trifunctional "T" units: CH
3SiO
3/2 results in the formation of branched linear or cyclic volatile methyl siloxanes.
The presence of tetrafunctional "Q" units SiO
4/2 results in the formation of branched linear or cyclic volatile methyl siloxanes.
[0047] Linear VMS have the formula (CH
3)
3SiO{(CH
3)2SiO}
kSi(CH
3)3 where k is 0-5. Cyclic VMS have the formula {(CH
3)
2Si0}m where m is 3-9. Preferably, these volatile methyl siloxane have a boiling point
less than 250° C. and viscosity of 0.65 to 5.0 mm
2/s
.
[0048] Representative linear volatile methyl siloxanes include, but are not limited to,
hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane,
tetradecamethylhexasiloxane, and hexadecamethylheptasiloxane. Representative cyclic
volatile methyl siloxanes are hexamethylcyclotrisiloxane; octamethylcyclotetrasiloxane,
decamethylcyclopentasiloxane; and dodecamethylcyclohexasiloxane.
[0049] Representative branched volatile methyl siloxanes are heptamethyl-3-{(trimethylsilyl)oxy}trisiloxane,
hexamethyl-3,3,bis {(trimethylsilyl)oxy}trisiloxane, and pentamethyl {(trimethylsilyl)oxy}cyclotrisiloxane.
[0050] The silicone fluid useful herein also includes using silicone fluids represented
by formulas R
3SiO(R
2SiO)
nSiR
3 and (R
2SiO)p wherein R is as defined above. The value of subscript n is 0-80, preferably
5-20. The value of subscript p is 3-9, preferably 4-6. These polysiloxanes have a
viscosity generally in the range of 1-100 mm
2/s. Silicone fluids can also be used where n has a value sufficient to provide siloxane
polymers with a viscosity in the range of 100-1,000 mm
2/sec. Typically, n can be 80-375. Illustrative of such silicone fluids are polydimethylsiloxane,
polydiethylsiloxane, polymethylethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane.
[0051] Functional silicone fluids can also be employed as an emulsion liquid. Useful functional
silicone fluids are represented by the formula R
3SiO(RFSiO)nSiR
3 where F is a functional group as defined above and is essentially unreactive with
siloxane (I) and crosslinker (II). Examples of functional silicone fluids include,
but are not limited to, are acrylamide functional siloxane fluids, acrylate functional
siloxane fluids, carbinol functional siloxane fluids, carboxy functional siloxane
fluids, chloroalkyl functional siloxane fluids, glycol functional siloxane fluids,
ketal functional siloxane fluids, mercapto functional siloxane fluids, methyl ester
functional siloxane fluids, perfluoro functional siloxane fluids, polyisobutylene
(PIB) functional siloxane fluids, silanol functional siloxanes, and vinyl functional
siloxane fluids.
[0053] Polar organic compounds useful herein include monohydroxy alcohols such as ethyl
alcohol and isopropyl alcohol; diols and triols such as propylene glycol, 2-methyl-1,3-propane
diol HOCH
2CH(CH
3)CH
2OH, 1,2-hexanediol CH
3(CH
2)
3CH(OH)CH
2OH and glycerol; glycerol esters such as glyceryl triacetate (triacetin), glyceryl
tripropionate (tripropionin), and glyceryl tributyrate (tributyrin); and polyglycols
such as polyethylene glycols and polypropylene glycols, among which are PPG-14 butyl
ether C
4H
9[OCH(CH
3)CH
2]
14OH.
[0054] Non-polar organic compounds may be exemplified by, but not limited to, aromatic hydrocarbons,
aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols,
glycol ethers, alkyl halides, or aromatic halides. Representative compounds are alcohols
such as methanol, ethanol, 1-propanol, cyclohexanol, benzyl alcohol, 2-octanol, ethylene
glycol, propylene glycol, and glycerol; aliphatic hydrocarbons such as pentane, cyclohexane,
heptane, Varnish Maker's & Painter's (VM&P) solvent, and mineral spirits; alkyl halides
such as chloroform, carbon tetrachloride, perchloroethylene, ethyl chloride, and chlorobenzene;
aromatic hydrocarbons such as benzene, toluene, ethylbenzene, and xylene; esters such
as ethyl acetate, isopropyl acetate, ethyl acetoacetate, amyl acetate, isobutyl isobutyrate
benzyl acetate, and isopropyl palmitate; ethers such as ethyl ether, n-butyl ether,
tetrahydrofuran, and 1,4-dioxane; glycol ethers such as ethylene glycol monomethyl
ether, ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether,
and propylene glycol monophenyl ether; ketones such as acetone, methyl ethyl ketone,
cyclohexanone, diacetone alcohol, methyl amyl ketone, and diisobutyl ketone; petroleum
hydrocarbons such as petroleum jelly, mineral oil, gasoline, naphtha, kerosene, gas
oil, heavy oil, and crude oil; lubricating oils such as spindle oil and turbine oil;
and fatty oils such as corn oil, soybean oil, olive oil, rape seed oil, cotton seed
oil, sardine oil, herring oil, and whale oil.
[0055] Non-polar organic compounds are described in
U.S. Patent No. 5,948,855 issued September 7, 1999, herein incorporated by reference for its teaching of non-polar organic compounds.
In particular the non-polar organic compounds can be fragrances, natural oils derived
from animal, vegetable or mineral sources. Most preferred are cosmetic oils such as
almond oil, apricot kernel oil, avocado oil, cacao butter (theobroma oil), carrot
seed oil, castor oil, citrus seed oil, coconut oil, corn oil, cottonseed oil, cucumber
oil, egg oil, jojoba oil, lanolin oil, linseed oil, mineral oil, mink oil, olive oil,
palm kernel oil, peach kernel oil, peanut oil, rapeseed oil, safflower oil, sesame
oil, shark liver oil, soybean oil, sunflower seed oil, sweet almond oil, tallow (beef)
oil, tallow (mutton) oil, turtle oil, vegetable oil, whale oil, and wheat germ oil.
[0056] Additionally present is at least one surfactant (V). The surfactant is typically
present in the amount of 0.1 to 40 wt. % based on the total composition. Preferably
the surfactant is present in the amount of 2 to 20 wt. % based on the total composition
and more preferably in the amount of 8 to 12 wt. %. The surfactant can be a nonionic,
cationic, anionic, or a mixture of such surfactants. Most preferred are organic nonionic
surfactants, but the nonionic surfactant can be one containing silicon atoms. Most
preferred are alcohol ethoxylates R
2-(OCH
2CH
2)
cOH, most particularly fatty alcohol ethoxylates. Fatty alcohol ethoxylates typically
contain the characteristic group -(OCH
2CH
2)
cOH which is attached to fatty hydrocarbon residue R
2 which contains eight to twenty carbon atoms, such as lauryl (C
12), cetyl (C
16) and stearyl (C
18). While the value of "c" may range from 1 to 100, its value is typically in the range
of 2 to 40.
[0057] Some examples of suitable nonionic surfactants are polyoxyethylene (4) lauryl ether,
polyoxyethylene (5) lauryl ether, polyoxyethylene (23) lauryl ether, polyoxyethylene
(2) cetyl ether polyoxyethylene (10) cetyl ether, polyoxyethylene (20) cetyl ether,
polyoxyethylene (2) stearyl ether, polyoxyethylene (10) stearyl ether, polyoxyethylene
(20) stearyl ether, polyoxyethylene (21) stearyl ether, polyoxyethylene (100) stearyl
ether, polyoxyethylene (2) oleyl ether, and polyoxyethylene (10) oleyl ether. These
and other fatty alcohol ethoxylates are commercially available under such names as
ALFONIC
®, BRIJ, GENAPOL
®, LUTENSOL, NEODOL
®, RENEX, SOFTANOL, SURFONIC
®, TERGITOL
®, TRYCOL, and VOLPO.
[0058] One especially useful nonionic surfactant is polyoxyethylene (23) lauryl ether, a
product sold under the name BRIJ 35L by ICI Surfactants, Wilmington, Delaware. It
has an HLB of about 16.9
[0059] Cationic surfactants useful in the invention include compounds containing quaternary
ammonium hydrophilic moieties in the molecule which are positively charged, such as
quaternary ammonium salts represented by R
3R
4R
SR
6N
+X
- where R
3 to R
6 are alkyl groups containing 1-30 carbon atoms, or alkyl groups derived from tallow,
coconut oil, or soy; and X is halogen such as chlorine or bromine, or X can be a methosulfate
group. Most preferred are dialkyldimethyl ammonium salts represented by R
7R
8N
+(CH
3)
2X
-, where R
7 and R
8 are alkyl groups containing 12-30 carbon atoms, or alkyl groups derived from tallow,
coconut oil, or soy; and X is halogen or a methosulfate group. Monoalkyltrimethyl
ammonium salts can also be employed, and are represented by R
9N
+(CH
3)
3X
- where R
9 is an alkyl group containing 12-30 carbon atoms, or an alkyl group derived from tallow,
coconut oil, or soy; and X is halogen or a methosulfate group.
[0060] Representative quaternary ammonium salts are dodecyltrimethyl ammonium bromide (DTAB),
didodecyldimethyl ammonium bromide, dihexadecyldimethyl ammonium chloride, dihexadecyldimethyl
ammonium bromide, dioctadecyldimethyl ammonium chloride, dieicosyldimethyl ammonium
chloride, didocosyldimethyl ammonium chloride, dicoconutdimethyl ammonium chloride,
ditallowdimethyl ammonium chloride, and ditallowdimethyl ammonium bromide. These and
other quaternary ammonium salts are commercially available under such names as ADOGEN,
ARQUAD, SERVAMINE, TOMAH, and VARIQUAT.
[0061] Examples of anionic surfactants include sulfonic acids and their salt derivatives;
alkali metal sulfosuccinates; sulfonated glyceryl esters of fatty acids such as sulfonated
monoglycerides of coconut oil acids; salts of sulfonated monovalent alcohol esters
such as sodium oleyl isothionate; amides of amino sulfonic acids such as the sodium
salt of oleyl methyl tauride; sulfonated products of fatty acid nitriles such as palinitonitrile
sulfonate; sulfonated aromatic hydrocarbons such as sodium alpha-naphthalene monosulfonate;
condensation products of naphthalene sulfonic acids with formaldehyde; sodium octahydro
anthracene sulfonate; alkali metal alkyl sulfates such as sodium lauryl (dodecyl)
sulfate CH
3(CH
2)
11OSO
3Na; ether sulfates having alkyl groups of eight or more carbon atoms; and alkylaryl
sulfonates having one or more alkyl groups of eight or more carbon atoms.
[0062] Commercial anionic surfactants useful in this invention include triethanolamine linear
alkyl sulfonate sold under the name BIO-SOFT N-300 by the Stepan Company, Northfield,
Illinois; sulfates sold under the name POLYSTEP by the Stepan Company; and sodium
n-hexadecyl diphenyloxide disulfonate sold under the name DOWFAX 8390 by The Dow Chemical
Company, Midland, Michigan.
[0063] There is also present in the emulsion composition an active ingredient (VI). The
active ingredient is typically present in the amount of 10 to 50 wt. % based on the
total composition. Preferably the surfactant is present in the amount of 2 to 20 wt.
% based on the total composition and more preferably in the amount of 8 to 12 wt.
%. The active ingredient may be reactive with the siloxane (I) or crosslinker (II)
resulting in the active ingredient being bonded into the silicone particle from which
it can later be released. Or the active ingredient can be blended into the composition
resulting in it being encapsulated by the silicone particle.
[0064] Active ingredients useful herein include, but are not limited to sunscreens (i.e.,
an UV absorber/UV light stabilizer), fragrances, vitamins, drugs including activated
antiperspirant salts such as aluminum chlorohydrate and aluminum-zirconium trichlorohydrate,
and α-hydroxy acids such as glycolic acid, lactic acid, tartaric acid, and citric
acid, i.e.,
fruit acids and mixtures thereof. Preferabley the active ingredient is a suscreen or fragrance.
Vitamins and drugs which can be used are described in
U.S. Patent No. 5,948,855, herein incorporated by reference for its teaching of these actives. These active
ingredients may be further exemplified by vitamin C, vitamin B
1, vitamin B
2, vitamin B
6, vitamin B
12, niacin, folic acid, biotin, and pantothenic acid.
[0065] Fragrances may be exemplified by, but not limited to, perfume ketones and perfume
aldehydes.
[0066] Preferably the perfume ketone is selected for its odor character from buccoxime;
iso jasmone; methyl beta naphthyl ketone; musk indanone; tonalid/musk plus; Alpha-Damascone,
Beta-Damascone, Delta-Damascone, Iso-Damascone, Damascenone, Damarose, Methyl-Dihydrojasmonate,
Menthone, Carvone, Camphor, Fenchone, Alpha-Ionone, Beta-lonone, Gamma-Methyl so-called
lonone, Fleuramone, Dihydrojasmone, Cis-Jasmone, Iso-E-Super, Methyl-Cedrenyl-ketone
or Methyl- Cedrylone, Acetophenone, MethylAcetophenone, Para-Methoxy-Acetophenone,
Methyl-Beta-Naphtyl-Ketone, BenzylAcetone, Benzophenone, Para-Hydroxy-Phenyl-Butanone,
Celery Ketone or Livescone, 6-Isopropyldecahydro-2-naphtone, Dimethyl-Octenone, Freskomenthe,
4-(1-Ethoxyvinyl)-3,3,5,5,-tetramethyl-Cyclohexanone, Methyl-Heptenone, 2-(2-(4-Methyl-3-cyclohexen-1-yl)propyl)-cyclopentanone,
1-(p-Menthen-6(2)-yl)-1-propanone, 4-(4-Hydroxy-3-methoxyphenyl)-2-butanone, 2-Acetyl-3,3-Dimethyl-Norbomane,
6,7-Dihydro-1,2,3,3-Pentamethyl-4(5H-Indanone, 4-Damascol, Dulcinyl or Cassione, Gelsone,
Hexalon, Isocyclemone E, Methyl Cyclocitrone, Methyl-Lavender-Ketone, Orivon, Para-tertiary-Butyl-Cyclohexanone,
Verdone, Delphone, Muscone, Neobutenone, Plicatone, Veloutone, 2,4,4,7-Tetramethyl-oct-6-en-3-one,
and Tetrameran.
[0067] More preferably, the perfume ketones are selected for its odor character from Alpha
Damascone, Delta Damascone, Iso Damascone, Carvone, Gamma-Methyl-Ionone, Iso-E-Super,
2,4,4,7-Tetramethyl-oct-6-en-3-one, Benzyl Acetone, Beta Damascone, Damascenone, methyl
dihydroj asmonate, methyl cedrylone, and mixtures thereof.
[0068] Preferably, the perfume aldehyde is selected for its odor character from adoxal;
anisic aldehyde; cymal; ethyl vanillin; florhydral; helional; heliotropin; hydroxycitronellal;
koavone; lauric aldehyde; lyral; methyl nonyl acetaldehyde; P. T. bucinal; phenyl
acetaldehyde; undecylenic aldehyde; vanillin; 2,6,10-trimethyl-9-undecenal, 3-dodecen-1-al,
alpha-n-amyl cinnamic aldehyde, 4-methoxybenzaldehyde, benzaldehyde, 3-(4-tert butylphenyl)-propanal,
2-methyl-3-(para-methoxyphenyl propanal, 2-methyl-4-(2,6,6-trimethyl-2(1)-cyclohexen-1-yl)
butanal, 3-phenyl-2-propenal, cis-/trans-3,7-dimethyl-2,6-octadien-1-al, 3,7-dimethyl-6-octen-1-al,
[(3,7-dimethyl-6-octenyl)oxy] acetaldehyde, 4-isopropylbenzyaldehyde, 1,2,3,4,5,6,7,8-octahydro-8,8-dimethyl-2-naphthaldehyde,
2,4-dimethyl-3-cyclohexen-1-carboxaldehyde,
2-methyl-3-(isopropylphenyl)propanal, 1-decanal; decyl aldehyde, 2,6-dimethyl-5-heptenal,
4-(tricyclo[5.2.1.0(2,6)]-decylidene-8)-butanal, octahydro-4,7-methano-1H-indenecarboxaldehyde,
3-ethoxy-4-hydroxy benzaldehyde, para-ethyl-alpha, alpha-dimethyl hydrocinnamaldehyde,
alpha-methyl-3,4-(methylenedioxy)-hydrocinnamaldehyde, 3,4-methylenedioxybenzaldehyde,
alpha-n-hexyl cinnamic aldehyde, m-cymene-7-carboxaldehyde, alpha-methyl phenyl acetaldehyde,
7-hydroxy-3,7-dimethyl octanal, Undecenal, 2,4,6-trimethyl-3-cyclohexene-1-carboxaldehyde,
4-(3)(4-methyl-3-pentenyl)-3-cyclohexen-carboxaldehyde,
1-dodecanal, 2,4-dimethyl cyclohexene-3-carboxaldehyde, 4-(4-hydroxy-4-methyl pentyl)-3-cylohexene-1-carboxaldehyde,
7-methoxy-3,7-dimethyloctan-1-al, 2-methyl undecanal, 2-methyl,decanal, 1-nonanal,
1-octanal, 2,6,10-trimetbyl-5,9-undecadienal, 2-methyl-3-(4-tertbutyl)propanal, dihydrocinnamic
aldehyde, 1-methyl-4-(4-methyl-3-pentenyl)-3-cyclohexene-1-carbox aldehyde, 5 or 6
methoxy0hexahydro-4,7-methanoindan-1 or 2- carboxaldehyde, 3,7-dimethyloctan-1-al,
1 -undecanal, 10-undecen-1-al, 4-hydroxy-3-methoxy
benzaldehyde, 1-methyl-3-(4-methylpentyl)-3-cyclhexenecarboxaldehyde, 7-hydroxy-3,7-dimethyl-octanal,
trans-4-decenal, 2,6-nonadienal, paratolylacetaldehyde; 4-methylphenylacetaldehyde,
2-methyl-4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butena 1, ortho-methoxycinnamic aldehyde,
3,5,6-trimethyl-3-cyclohexene carboxaldehyde, 3,7-dimethyl-2-methylene-6-octenal,
phenoxyacetaldehyde, 5,9-dimethyl-4,8-decadienal, peony aldehyde (6,10-dimethyl-3-oxa-5,9-undecadien-1-al),
hexahydro-4,7-methanoindan-1-carboxaldehyde, 2-methyl
octanal, alpha-methyl-4-(1-methyl ethyl) benzene acetaldehyde, 6,6-dimethyl-2-norpinene-2-propionaldehyde,
para methyl phenoxy acetaldehyde, 2-methyl-3-phenyl-2-propen-1-al, 3,5,5-trimethyl
hexanal, Hexahydro-8,8-dimethyl-2-naphthaldehyde, 3-propyl-bicyclo[2.2.1]-hept-5-ene-2-carbaldehyde,
9-decenal, 3-methyl-5-phenyl-1-pentanal, methylnonyl acetaldehyde, hexanal, trans-2-hexenal,
1-p-menthene-q-carboxaldehyde and mixtures thereof.
[0069] More preferred aldehydes are selected for its odor character from 1-decanal, benzaldehyde,
florhydral, 2,4-dimethyl-3-cyclohexen-1-carboxaldehyde; cis/trans-3,7-dimethyl-2,6-octadien-1-al;
heliotropin; 2,4,6-trimethyl-3-cyclohexene-1-carboxaldehyde; 2,6-nonadienal; alpha-n-amyl
cinnamic aldehyde, alpha-n-hexyl cinnamic aldehyde, P.T. Bucinal, lyral, cymal, methyl
nonyl acetaldehyde, hexanal, trans-2-hexenal, and mixture thereof.
[0070] In the above list of perfume ingredients, some are commercial names conventionally
known to one skilled in the art, and also includes isomers. Such isomers are also
suitable for use in the present invention.
[0071] Other active ingredients which can be carried in a phase(s) of the silicone fluid
or non-polar organic compound include, but are not limited to vitamins and drugs among
which are vitamin A, RETINOL, C
2-C
18 esters of RETINOL, vitamin E, tocopherol, esters of vitamin E, retinyl acetate, retinyl
palmitate, retinyl propionate, α-tocopherol, tocophersolan, tocopheryl acetate, tocopheryl
linoleate, tocopheryl nicotinate, tocopheryl succinate, and mixtures thereof. These
active ingredients are described in
U.S. Patent No. 5,948,855, herein incorporated by reference for its teaching of these actives.
[0072] Optionally, there may be present a compound (VII) that introduces functional groups,
F, into the silicone particle or emulsion ("functional compound") wherein F is as
described above. The functional compound may be silicone, organic. It may be reactive
with the siloxane (I) and/or crosslinker (II) resulting in functionality that is bonded
directly to the silicone particle. It may be unreactive resulting in functionality
that is in the emulsion. The functional compound can be added before, during or after
the crosslinking reaction. Combinations of functional compounds can be used or combinations
of functionality may be used so long as the functional compound does not substantially
interfere with the crosslinking chemistry.
[0073] The silicone particles are prepared by combining the siloxane (1), crosslinker (II),
at least one emulsion liquid (III), surfactant (IV), and active ingredient (V) while
mixing sufficiently to produce the emulsion. Methods known in the art for producing
emulsions can be used herein. The order of addition of components is not critical.
Optional components and additional diluents may be added before, during or after the
emulsification reaction has taken place.
[0074] Core-shell particles are typically formed by forming a first mixture comprising the
active ingredient (V) with one reactant (siloxane or crosslinker), preferably an amine
functional crosslinker; forming a second mixture comprising the other reactant, preferably
an epoxy silicone with the emulsion liquid (III), preferably water and surfactant
(IV) and thereafter combining and emulsifying the two mixtures. It is theorized that
the reaction between siloxane (I) and crosslinker (II) takes place at the interface
and forms a rigid particle, protecting the encapsulated material from the external
phase.
[0075] Gel particles are typically formed by blending all of the components and thereafter
emulsifying and reacting to form the particles.
[0076] Although heating is not required it is beneficial to heat while emulsifying. Typically
the emulsion mixture is heated to a temperature of 25°C to 150°C, preferably 50°C
to 100°C.
[0077] One of the benefits derived from silicone particles prepared according to this invention
is their structural integrity against changes in such parameters as temperature, and
the presence or absence of other components such as water, surfactants, and oils.
Another benefit is their reduced permeability for entrapped active ingredients by
the formation of crosslinked structures.
[0078] The silicone particles are useful in personal care products, for example, in preparing
antiperspirants and deodorants. They can be used in skin creams, skin care lotions,
moisturizers, facial treatments such as acne or wrinkle removers, personal and facial
cleansers, bath oils, perfumes, colognes, sachets, sunscreens, pre-shave and after-shave
lotions, shaving soaps, and shaving lathers. They can be used in hair shampoos, hair
conditioners, hair sprays, mousses, permanents, depilatories, and cuticle coats. In
cosmetics they can be added to make-ups, color cosmetics, foundations, blushes, lipsticks,
eyeliners, mascara, oil removers, color cosmetic removers, and powders. In such applications
the compositions may include oil soluble, polar solvent soluble, and water-soluble
ingredients such as vitamins as noted above.
[0079] These compositions are also capable of functioning as carriers for pharmaceuticals,
biocides, herbicides, pesticides, and other biologically active substances; and they
have utility as additives for cellulosic or synthetic nonwoven carrier substrates
used in wet-like cleansing wipes such as wet-wipes, tissues, and towels, marketed
generally for personal hygiene and household cleaning tasks.
EXAMPLES
[0080] The following non-limiting examples are provided so that one skilled in the art may
more readily understand the invention.
Example 1
[0081]
| Water Phase: |
| 40.0g |
DI water |
| 10.0g |
TergitolTMN-6 (Ethoxylated trimethylnonanol) |
| 2.0g |
Lupasol WF (polyethyleneimine) |
| Oil Phase: |
| 40.0g |
Damascone |
| 8.0 g |
Octamethyl-3,5-Bis(Gamma-Glycidoxypropyl) Tetrasiloxane |
[0082] Each phase was mixed separately. The oil phase was added slowly to the water phase
with mixing. The mixture was heated to 70°C while mixing for 2½ hours. The resulting
product was a creamy oil-in-water emulsion.
Example 2
[0083]
| Water Phase |
| 39.0g |
DI Water |
| 5.0g |
Lupasol WF (polyethyleneimine) |
| Oil Phase |
| 40.0g |
OMC (Octylmethoxycinnimate) |
| 4.0g |
Brij 30 (Polyoxyethylene (4) lauryl ether) |
| 12.0g |
Octamethyl-3,5-Bis(Gamma-Glycidoxypropyl) Tetrasiloxane |
[0084] The oil and water phases were each mixed separately. The oil phase was slowly added
to the water phase while mixing @ 700 rpm. The mixture was heated to 85°C+/-2°C with
continuous mixing for 3 hours. The resulting product was a thick, creamy emulsion
that was dilution stable. Under a microscope, rigid particles were evident.
Example 3
[0085]
| 40.6g |
Castor Oil |
|
| 10.0g |
Tergitol 15-S-3 |
Alcohol Ethoxylate |
| 5.9g |
Lupasol WF |
Polyethyleneimine |
| 5.0g |
Octamethyl-3,5-Bis(Gamma-Glycidoxypropyl) |
Tetrasiloxane |
[0086] All ingredients were mixed together and heated to 80°C for 2½ hours. The resulting
prouduct was clear microemulsions gels.
Example 4
[0087]
| 22g |
Isopar M |
| 8.0g |
Delta-damascone |
| 5.or |
Neodol 23-3 (Alcohol Ethoxylate) |
| 3g |
Lupasol WF (Polyethyleneimine) |
| 12g |
Octamethyl-3,5-Bis(Gamma-Glycidoxypropyl) Tetrasiloxane |
[0088] All ingredients were mixed together and heated to 80°C for 2½ hours. The resulting
prouduct was clear microemulsions gels.
Example 5
[0089]
| Oil Phase |
|
| 2-8566 |
9.0% |
| Delta Damascone |
40% |
| Water Phase |
|
| DI water |
40% |
| Tergital TMN-6 |
10% |
| Cross-linker |
|
| 1,4-Butanediol Diglycidal Ether, 95% |
1% |
Components of oil phase were combined. Components of the water phase were combined
and the oil phase was added to the water phase while mixing. The mixture was heated
to about 80°C with continued mixing for 1 hr. The cross-linker was added while continuing
to mix and heat for 1 hour. The result was an oil-in-water emulsion having a very
fine particle size.