CROSS-REFERENCE TO RELATED APPLICATIONS
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH AND DEVELOPMENT
BACKGROUND OF THE INVENTION
Technical Field
[0003] An "all-in-one" spacer and seal useful in insulating glass units is based on silane-functional,
elastomeric, organic polymer (
e.
g., silicon-curable polyisobutylene or silicon-curable butyl rubber) technology. This
chemically crosslinking (curing) flexible thermoset spacer and seal offers a solution
to overcome the current shortfalls of commercially available thermoplastic spacer
materials. The thermoset material cures, develops adhesion, and offers the strength
to support the glass panels of an insulating glass unit. The spacer and seal offers
four functions of the edge-seal, namely sealing, bonding, spacing, and desiccating,
thus an "all-in-one" solution.
Background
[0004] Insulating glass (IG) units are known in the art. In a typical IG unit, panes of
glass are held parallel to one another a fixed distance apart by a spacer. A primary
sealant is used as a barrier between the panes. The primary sealant may be used to
prevent water vapor from migrating into the space between the panes (interpane space).
The primary sealant may also be used to prevent inert gas, such as argon, from migrating
out of the interpane space. A secondary sealant is used to adhere the panes to each
other and the spacer. Desiccants may be added to the spacer to remove moisture from
the interpane space. The spacer may be formed from metal (
e.
g., aluminum, stainless steel), plastic, plastic coated metal, foam (
e.
g., EPDM, silicone), or other suitable materials.
Problems to be Solved
[0005] A more efficient method for producing IG units is desired. A single sealant composition
that performs more than one of the functions of the primary sealant, secondary sealant,
spacer, and desiccant namely sealing, bonding, spacing, and desiccation, is desired.
Preferably, a single sealant composition that performs all of these functions, thus
an "all-in-one" solution, is desired.
BRIEF SUMMARY OF THE INVENTION
[0006] An "all-in-one" sealant composition useful in IG applications is disclosed. The composition
comprises: (A) a moisture-curable, silane-functional, elastomeric, organic polymer;
(B) a condensation catalyst; (C) a drying agent; and (D) a water release agent that
releases water over an application temperature range.
[0007] The inventors surprisingly found that a moisture-curable, silane-functional, elastomeric,
organic polymer can be cured in the presence of both the drying agent and the water
release agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 is a partial cross section of an IG unit.
[0009] Figure 2 is a partial cross section of an IG unit.
DETAILED DESCRIPTION OF THE INVENTION
[0010] The invention relates to an "all-in-one" sealant composition useful in IG applications.
The composition may be a one-part or multiple-part composition. The composition comprises:
(A) 10 weight parts to 65 weight parts of a moisture-curable, silane-functional, elastomeric,
organic polymer; (B) 0.1 weight parts to 3 weight parts of a condensation catalyst;
(C) 15 weight parts to 25 weight parts of a physical drying agent; (D) 5 weight parts
to 30 weight parts a water release agent that releases water over an application temperature
range; (E) 0 weight parts to 30 weight parts of a filler other than ingredients (C)
and (D); (F) 0 weight parts to 30 weight parts of a non-reactive, elastomeric, organic
polymer; (G) 0 weight parts to 5 weight parts of a crosslinker; (H) 0 weight parts
to 5 weight parts of a chemical drying agent other than ingredient (G); (I) 0 weight
parts to 5 weight parts of an adhesion promoter other than ingredients (G) and (H);
(J) 0 weight parts to 20 weight parts of a microcrystalline wax, which is a solid
at 25 °C and has a melting point selected such that the wax melts at the low end of
the desired application temperature range; (K) 0 weight parts to 3 weight parts of
an anti-aging additive; and (L) 0 weight parts to 20 weight parts of a tackifying
agent.
Ingredient (A) Moisture-Curable, Silane-Functional, Elastomeric. Organic Polymer
[0011] Ingredient (A) is a moisture-curable, silane-functional, elastomeric, organic polymer.
For purposes of this application, 'elastomeric' refers to the rubbery consistency
imparted to the composition by ingredient (A), and ingredient (A) is distinguished
from semi-crystalline and amorphous polyolefins (
e.
g., alpha-olefins), commonly referred to as thermoplastic polymers.
[0012] Ingredient (A) may comprise a silylated copolymer of an iso-mono-olefin and a vinyl
aromatic monomer, a silylated copolymer of a diene and a vinyl aromatic monomer, a
silylated copolymer of an olefin and a diene (
e.
g., an optionally halogenated silylated butyl rubber prepared from polyisobutylene
and isoprene), or a combination thereof (silylated copolymers), a silylated homopolymer
of the iso-mono-olefin, a silylated homopolymer of the vinyl aromatic monomer, a silylated
homopolymer of the diene (
e.
g., silylated polybutadiene or silylated hydrogenated polybutadiene), or a combination
thereof (silylated homopolymers) or a combination silylated copolymers and silylated
homopolymers. For purposes of this application, silylated copolymers and silylated
homopolymers are referred to collectively as 'silylated polymers'. The silylated polymer
may optionally contain one or more halogen groups, particularly bromine groups.
[0013] Ingredient (A) may be a silylated polymer comprising a silane-functional group of
formula:

where D represents a divalent organic group, each X independently represents a hydrolyzable
group, each R independently represents a monovalent hydrocarbon group, subscript e
represents 0, 1, 2, or 3, subscript f represents 0, 1, or 2, and subscript g has a
value ranging from 0 to 18, with the proviso that the sum of e + f is at least 1.
[0014] Alternatively, D may be a divalent hydrocarbon group such as ethylene, propylene,
butylene, and hexylene. Alternatively, each X may be selected from the group consisting
of an alkoxy group; an alkenyloxy group; an amido group, such as an acetamido; a methylacetamido
group, or benzamido group; an acyloxy group such as acetoxy; an amino group; an aminoxy
group; a hydroxyl group; a mercapto group; an oximo group, and a ketoximo group. Alternatively,
each R may be independently selected from alkyl groups of 1 to 20 carbon atoms, aryl
groups of 6 to 20 carbon atoms, and aralkyl groups of 7 to 20 carbon atoms. Alternatively,
subscript g is 0.
[0015] Examples of suitable mono-iso-olefins include but are not limited to isoalkylenes
such as isobutylene, isopentylene, isohexylene, and isoheptylene; alternatively isobutylene.
Examples of suitable vinyl aromatic monomers include but are not limited to alkylstyrenes
such as alpha-methylstyrene, t-butylstyrene, and paramethylstyrene; alternatively
para-methylstyrene. Examples of suitable alkyl groups include methyl, ethyl, n-propyl,
isopropyl, n-butyl, isobutyl, and t-butyl; alternatively methyl. Examples of suitable
alkenyl groups include, vinyl, allyl, propenyl, butenyl, and hexenyl; alternatively
vinyl. Ingredient (A) may have average molecular weight (Mn) ranging from 20,000 to
100,000, alternatively 25,000 to 50,000, and alternatively 28,000 to 35,000. Ingredient
(A) may contain an amount of silane-functional groups ranging from 0.2 % to 10 %,
alternatively 0.5 % to 5 %, and alternatively 0.5 % to 2.0 %.
[0016] Suitable examples of silylated copolymers and methods for their preparation are known
in the art and are exemplified by the silylated copolymers disclosed in
EP 0 320 259 B1 (Dow Coming);
DE 19,821,356 Al (Metallgesellschaft); and
U.S. Patents 4,900,772 (Kaneka);
4,904,732 (Kaneka);
5,120,379 (Kaneka);
5,262,502 (Kaneka);
5,290,873 (Kaneka);
5,580,925 (Kaneka),
4,808,664 (Dow Corning),
6,380,316 (Dow Coming/Exxonmobil); and
6,177,519 (Dow Corning/ExxonMobil).
U.S. Patents 6,380,316 and
6,177,519 are hereby incorporated by reference. Briefly stated, the method for preparing the
silylated copolymers of
U.S. Patent 6,177,519 involves contacting i) an olefin copolymer having at least 50 mole % of an iso-mono-olefin
having 4 to 7 carbon atoms and a vinyl aromatic monomer; ii) a silane having at least
two hydrolyzable organic groups and at least one olefinically unsaturated hydrocarbon
or hydrocarbonoxy group; and iii) a free radical generating agent.
[0017] Alternatively, silylated copolymers may be prepared by a method comprising conversion
of commercially available hydroxylated polybutadiene (such as those commercially available
from Sartomer under tradename Poly BD) by known methods (
e.
g., reaction with isocyanate functional alkoxysilane, reaction with allylchloride in
presence of Na followed by hydrosilylation).
[0018] The amount of ingredient (A) may range from 10 parts to 65 parts, alternatively 10
parts to 35 parts, and alternatively 15 parts to 35 parts, based on the weight of
the composition. Ingredient (A) may be one moisture-curable, silane-functional, elastomeric,
organic polymer. Alternatively, ingredient (A) may comprise two or more moisture-curable,
silane-functional, elastomeric, organic polymers that differ in at least one of the
following properties: structure, viscosity, average molecular weight, polymer units,
and sequence.
Ingredient (B) Condensation Catalyst
[0019] Ingredient (B) is a condensation catalyst. Suitable condensation catalysts include
tin (IV) compounds, tin (II) compounds, and titanates. Examples of tin (IV) compounds
include dibutyl tin dilaurate (DBTDL), dimethyl tin dilaurate, di-(n-butyl)tin bis-ketonate,
dibutyl tin diacetate, dibutyl tin maleate, dibutyl tin diacetylacetonate, dibutyl
tin dimethoxide carbomethoxyphenyl tin tris-uberate, isobutyl tin triceroate, dimethyl
tin dibutyrate, dimethyl tin di-neodeconoate, triethyl tin tartrate, dibutyl tin dibenzoate,
butyltintri-2-ethylhexoate, a dioctyl tin diacetate, tin octylate, tin oleate, tin
butyrate, tin naphthenate, dimethyl tin dichloride, and a combination thereof. Tin
(IV) compounds are known in the art and are commercially available, such as Metatin
740 and Fascat 4202.
[0020] Examples of tin (II) compounds include tin (II) salts of organic carboxylic acids
such as tin (II) diacetate, tin (II) dioctanoate, tin (II) diethylhexanoate, tin (II)
dilaurate, stannous salts of carboxylic acids such as stannous octoate, stannous oleate,
stannous acetate, stannous laurate, and a combination thereof.
[0021] Examples of organofunctional titanates include 1,3-propanedioxytitanium bis(ethylacetoacetate);
1,3-propanedioxytitanium bis(acetylacetonate); diisopropoxytitanium bis(acetylacetonate);
2,3-di-isopropoxy-bis(ethylacetate)titanium; titanium naphthenate; tetrapropyltitanate;
tetrabutyltitanate; tetraethylhexyltitanate; tetraphenyltitanate; tetraoctadecyltitanate;
tetrabutoxytitanium; tetraisopropoxytitanium; ethyltriethanolaminetitanate; a betadicarbonyltitanium
compound such as bis(acetylacetonyl)diisopropyltitanate; or a combination thereof.
Siloxytitanates are exemplified by tetrakis(trimethylsiloxy)titanium, bis(trimethylsiloxy)bis(isopropoxy)titanium,
or a combination thereof.
[0022] The amount of ingredient (B) is sufficient to cure the composition. The amount of
ingredient (B) may range from 0.1 parts to 3 parts, alternatively 0.2 parts to 2 parts,
based on the weight of the composition. Ingredient (B) may be one condensation catalyst.
Alternatively, ingredient (B) may comprise two or more different condensation catalysts.
Ingredient (C) Drying Agent
[0023] Ingredient (C) is a drying agent. The drying agent binds water from various sources.
In IG applications, the drying agent may bind water that an IG unit contains between
panes upon its manufacture and/or that diffuses into the interpane space during service
life of the IG unit. The drying agent may bind by-products of the curing reaction
such as water and alcohols. The drying agent binds the water and by-products by physical
means. For example, the drying agent may bind the water and by-products by physically
adsorbing or absorbing them. Ingredient (C) may be added to the composition to perform
the desiccating function of an edge-seal in an IG unit and to reduce or eliminate
chemical fogging of the IG unit that may be caused by by-products of the curing reaction.
[0024] Examples of suitable adsorbents for ingredient (C) may be inorganic particulates.
The adsorbent may have a particle size of 10 micrometers or less, alternatively 5
micrometers or less. The adsorbent may have average pore size sufficient to adsorb
water and alcohols, for example 10 Å (Angstroms) or less, alternatively 5 Å or less,
and alternatively 3 Å or less. Examples of adsorbents include zeolites such as chabasite,
mordenite, and analcite; molecular sieves such as alkali metal alumino silicates,
silica gel, silica-magnesia gel, activated carbon, activated alumina, calcium oxide,
and combinations thereof. One skilled in the art would be able to select suitable
drying agents for ingredient (C) without undue experimentation. One skilled in the
art would recognize that certain drying agents such as silica gel will bind water,
while others such as molecular sieves may bind water, alcohols, or both.
[0025] Examples of commercially available drying agents include dry molecular sieves, such
as 3 Å (Angstrom) molecular sieves, which are commercially available from Grace Davidson
under the trademark SYLOSIV® and from Zeochem of Louisville, Kentucky, U.S.A. under
the trade name PURMOL, and 4 Å molecular sieves such as Doucil zeolite 4A available
from Ineos Silicas of Warrington, England. Other useful molecular sieves include MOLSIV
ADSORBENT TYPE 13X, 3A, 4A, and 5A, all of which are commercially available from UOP
of Illinois, U.S.A.; SILIPORITE NK 30AP and 65xP from Atofina of Philadelphia, Pennsylvania,
U.S.A.; and molecular sieves available from W.R. Grace of Maryland, U.S.A.
Ingredient (D) Water Release Agent
[0026] Ingredient (D) is a water release agent that releases water over an application temperature
range. Ingredient (D) is selected such that ingredient (D) contains an amount of water
sufficient to cure the composition and such that ingredient (D) releases the sufficient
amount of water to cure the composition when exposed for a sufficient amount of time
to a temperature in the application temperature range, for example, by the method
of reference example 2 herein. However, ingredient (D) binds the water sufficiently
to prevent too much from being released during processing. For example, ingredient
(D) binds the water sufficiently during compounding of the composition such that sufficient
water is available for curing the composition during or after the application process
in which the composition is used. This "controlled release" property also may provide
the benefit of ensuring that not too much water is released too rapidly during the
application process, since this may cause bubbling or voiding in the sealant formed
by curing the composition. For example, when the composition will be used in an IG
application, the application temperature range may be the temperature range at which
the composition will be applied or interposed between glass panes. The application
temperature range will depend on various factors including the IG unit fabricator's
particular fabrication process. Precipitated calcium carbonate may be used as ingredient
(D) when the application temperature ranges from 80 °C to 120 °C, alternatively 90
°C to 110 °C, and alternatively 90 °C to 100 °C. However, when the composition is
prepared on a continuous (
e.
g., twin-screw) compounder, the ingredients may be compounded at a temperature 20 °C
to 30 °C above the application temperature range for a short amount of time. Therefore,
ingredient (D) is selected to ensure that not all of the water content is released
during compounding, however ingredient (D) releases a sufficient amount of water to
cure the composition when exposed to the application temperature range for a sufficient
period of time. Precipitated calcium carbonate is available from Solvay under the
trademark WINNOFIL® SPM. The water release agent selected will depend on various factors
including the other ingredients selected for the composition, including catalyst type
and amount; and the process conditions during compounding, packaging, and application.
In a twin-screw compounder residence time may be less than a few minutes, typically
less than 1-2 minutes. The ingredients are heated rapidly because the surface/volume
ratio in the barrels and along the screw is high and heat is induced by shearing the
ingredients. How much water is removed from ingredient (D) depends on the water binding
capabilities, the temperature, the exposure time (duration), and the level of vacuum
used to strip the material passing through the compounder. Even with compounding temperatures
of up to 200 °C and full operational vacuum stripping, there remains enough water
on precipitated CaCO
3 to cure the composition, after ca. 3 weeks ambient storage, when exposed afterwards
at 90 °C for ca. 30 minutes. Without wishing to be bound by theory, it is thought
that with a twin screw compounding temperature of 120 °C there will remain enough
water on the precipitated CaCO
3 to cure the composition over a period of 1-2 weeks at room temperature when the composition
has been applied at 90 °C. The amount of ingredient (D) in the composition depends
on various factors including the selection of ingredients (A), (B) and (C) and whether
any optional ingredients are present, however the amount of ingredient (D) may range
from 5 to 30 parts based on the weight of the composition. Without wishing to be bound
by theory, it is thought that if the amount of ingredient (D) is less than 5 weight
parts based on 100 weight parts of the composition, then ingredient (D) may contain
insufficient water to cure the composition.
[0027] The present inventors surprisingly found that the composition of this invention will
cure in the presence of ingredient (C) the drying agent when the water source is present.
Without wishing to be bound by theory, it is thought that when the composition is
used in applications such as an IG unit, the low moisture permeability imparted by
ingredient (A) (and ingredient (F), if present) may prevent the composition from curing
by exposure to atmospheric moisture within a reasonable period of time. Ingredient
(D) is added to address this problem. Without wishing to be bound by theory, it is
thought when the composition is heated to the application temperature, the heat will
liberate the water, the water will react with the hydrolyzable groups on ingredient
(A) to cure the composition, and any by-products such as alcohols and/or water left
in the composition may be bound by ingredient (C), thereby allowing the condensation
reaction (which is an equilibrium reaction) to proceed toward completion and preventing
condensation of cure by-products, for example, between panes in an IG unit (known
as "chemical fogging").
[0028] For purposes of this application, ingredient (D) the water release agent may exclude
liquid water, hydrated metal salts such as those disclosed by
U.S. Patent 6,025,445, and combinations thereof. Without wishing to be bound by theory, it is thought that
adding liquid water to the composition may form steam during the compounding process
to make the composition, during the application process of the composition to a substrate,
or both. Without wishing to be bound by theory, it is thought that hydrated metal
salts may have a negative effect on the adhesion of composition, especially when the
adhesion needs to withstand environmental conditions that include water or water vapor.
Ingredient (E) Filler
[0029] The composition may optionally further comprise additional ingredient (E). Ingredient
(E) is a filler other than ingredients (C) and (D). Ingredient (E) generally does
not significantly impact the amount of water present during and after curing the composition.
Ingredient (E) may comprise a reinforcing filler, an extending filler, a thixotropic
filler, a pigment, or a combination thereof. One skilled in the art would be able
to select suitable additional fillers without undue experimentation. Examples of suitable
additional fillers include, but are not limited to, ground calcium carbonate, carbon
black, fumed silica, precipitated silica, talc, titanium dioxide, plastic powders,
glass or plastic (such as Saran
™) microspheres, high aspect ratio fillers such as mica or exfoliated mica, and combinations
thereof. The filler may optionally be treated with a treating agent, such as a fatty
acid (
e.
g., stearic acid).
[0030] Suitable fillers are known in the art and are commercially available. Ground calcium
carbonate is available from QCI Britannic of Miami, Florida, U.S.A. under the trademark
Imerys Gammasperse. Carbon black, such as 1011, is commercially available from Williams.
Silica is commercially available from Cabot Corporation.
[0031] The amount of ingredient (E) in the composition depends on various factors including
the specific water release agent selected and whether any additional fillers are present.
However, the amount of ingredient (E) may range from 0 parts to 30 parts, alternatively
5 parts to 30 parts, based on the weight of the composition. Ingredient (E) may be
one filler. Alternatively, ingredient (E) may comprise two or more fillers that differ
in at least one of the following properties: composition, particle size, and surface
treatment.
Ingredient (F) Non-reactive Binder
[0032] Ingredient (F) is a non-reactive, elastomeric, organic polymer,
i.
e., an elastomeric organic polymer that does not react with ingredient (A). Ingredient
(F) is compatible with ingredient (A),
i.
e., ingredient (F) does not form a two-phase system with ingredient (A). Ingredient
(F) may have sufficiently low gas and moisture permeability, for example, if the composition
will be used in an IG application. Ingredient (F) may have Mn ranging from 30,000
to 75,000. Alternatively, ingredient (F) may be a blend of a higher molecular weight,
non-reactive, elastomeric, organic polymer with a lower molecular weight, non-reactive,
elastomeric, organic polymer. In this case, the higher molecular weight polymer may
have Mn ranging from 100,000 to 600,000 and the lower molecular weight polymer may
have Mn ranging from 900 to 10,000, alternatively 900 to 3,000. The value for the
lower end of the range for Mn may be selected such that ingredient (F) has compatibility
with ingredient (A) and the other ingredients of the composition to minimize chemical
fogging in an IG unit in which the composition will be used.
[0033] Ingredient (F) may comprise a polyisobutylene. Polyisobutylenes are known in the
art and are commercially available. Examples suitable for use as ingredient (F) include
polyisobutylenes marketed under the trademark OPPANOL® by BASF Corporation of Germany.
Such polyisobutylenes are summarized in the table below.
OPPANOL® |
Mw |
Mw/Mn |
Mn |
Mv |
Viscosity (@150C) |
B10 |
36,000 |
3 |
12,000 |
40,000 |
40,000 |
B11 |
46,000 |
3.2 |
14,375 |
49,000 |
100,000 |
B12 |
51,000 |
3.2 |
15,938 |
55,000 |
150,000 |
B13 |
60,000 |
3.2 |
18,750 |
65,000 |
250,000 |
B14 |
65,000 |
3.3 |
19,697 |
73,000 |
450,000 |
B15 |
75,000 |
3.4 |
22,059 |
85,000 |
750,000 |
B30 |
|
|
73,000 |
200,000 |
|
B50 |
|
|
120,000 |
400,000 |
|
B80 |
|
|
200,000 |
800,000 |
|
B 100 |
|
|
250,000 |
1,100,000 |
|
B150 |
|
|
425,000 |
2,600,000 |
|
B200 |
|
|
600,000 |
4,000,000 |
|
Other polyisobutylenes include different Parleam grades such as highest molecular
weight hydrogenated polyisobutene PARLEAM® SV (POLYSYNLANE SV) from NOF CORPORATION
Functional Chemicals & Polymers Div., Yebisu Garden Place Tower, 20-3 Ebisu 4-chome,
Shibuya-ku, Tokyo 150-6019, Japan (Kinematic Viscosity (98.9°C) 4700). Other polyisobutylenes
are commercially available from ExxonMobil Chemical Co. of Baytown, Texas, U.S.A.
and include polyisobutylenes marketed under the trademark VISTANEX®, such as NML-80,
MML-100, MML-120, and MML-140. VISTANEX® polyisobutylenes are paraffinic hydrocarbon
polymers, composed of long, straight-chain macromolecules containing only chain-end
olefinic bonds. VISTANEX® MM polyisobutylenes have viscosity average molecular weight
ranging from 70,000 to 90,000. Lower molecular weight polyisobutylenes include VISTANEX®
LM, such as LM-MS (viscosity average molecular weight ranging from 8,700 to 10,000
also made by ExxonMobil Chemical Co.) and VISTANEX LM-MH (viscosity average molecular
weight of 10,000 to 11,700) as well as Soltex-PB-24 (Mn 950) and Indopol® H-100 (Mn
910) and Indopol® H-1200 (Mn 2100) from Amoco. Other polyisobutylenes are marketed
under the trademarks NAPVIS® and HYVIS® by BP Chemicals of London, England. These
polyisobutylenes include NAPVIS® 200, D10, and DE3; and HYVIS® 200. The NAPVIS® polyisobutylenes
may have Mn ranging from 900 to 1300. Alternatively, ingredient (F) may comprise butyl
rubber. Alternatively, ingredient (F) may comprise a styrene-ethylene/butylene-styrene
(SEBS) block copolymer, a styrene-ethylene/propylene-styrene (SEPS) block copolymer,
or a combination thereof. SEBS and SEPS block copolymers are known in the art and
are commercially available as Kraton® G polymers from Kraton Polymers U.S. LLC of
Houston, Texas, U.S.A., and as Septon polymers from Kuraray America, Inc., New York,
NY, U.S.A. Alternatively, ingredient (F) may comprise a polyolefin plastomer. Polyolefin
plastomers are known in the art and are commercially available as AFFINITY® GA 1900
and AFFINITY® GA 1950 from Dow Chemical Company, Elastomers & Specialty Products Division,
Midland, Michigan, U.S.A.
[0034] The amount of ingredient (F) range from 0 parts to 50 parts, alternatively 10 parts
to 40 parts, and alternatively 5 parts to 35 parts, based on the weight of the composition.
Ingredient (F) may be one non-reactive, elastomeric, organic polymer. Alternatively,
ingredient (F) may comprise two or more non-reactive, elastomeric, organic polymers
that differ in at least one of the following properties: structure, viscosity, average
molecular weight, polymer units, and sequence.
Ingredient (G) Crosslinker
[0035] Ingredient (G) is a crosslinker. Ingredient (G) may be a silane, an oligomeric reaction
product of the silane, or a combination thereof. Alkoxysilane crosslinkers may have
the general formula R
1aSiR
2(4-a), where each R
1 is independently a monovalent organic group such as an alkyl group, alkenyl group,
or aryl group; each R
2 is a hydrolyzable group; and a is 1, 2, or 3. Oligomeric crosslinkers may have the
general formula R
1Si(OSi(R
2)
3)
3, where R
1 and R
2 are as described above.
[0036] In the formulae above, suitable monovalent organic groups for R
1 include, but are not limited to, monovalent substituted and unsubstituted hydrocarbon
groups. Examples of monovalent unsubstituted hydrocarbon groups for R
1 include, but are not limited to, alkyl such as methyl, ethyl, propyl, pentyl, octyl,
undecyl, and octadecyl; cycloalkyl such as cyclohexyl; alkenyl such as vinyl, allyl,
and propenyl; aryl such as phenyl, tolyl, xylyl, benzyl, and 2-phenylethyl. Examples
of monovalent substituted hydrocarbon groups for R
1 include, but are not limited to, monovalent halogenated hydrocarbon groups such as
chlorinated alkyl groups such as chloromethyl and chloropropyl groups; fluorinated
alkyl groups such as fluoromethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl,
4,4,4,3,3-pentafluorobutyl, 5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl,
and 8,8,8,7,7-pentafluorooctyl; chlorinated cycloalkyl groups such as 2,2-dichlorocycliopropyl,
2,3-dichlorocyclopentyl; and fluorinated cycloalkyl groups such as 2,2-difluorocyclopropyl,
2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and 3,4-difluoro-5-methylcycloheptyl.
Examples of monovalent substituted hydrocarbon groups for R
1 include, but are not limited to, hydrocarbon groups substituted with oxygen atoms
such as glycidoxyalkyl, and hydrocarbon groups substituted with nitrogen atoms such
as aminoalkyl and cyano-functional groups such as cyanoethyl and cyanopropyl. Alternatively,
each R
1 may be an alkyl group, alkenyl group, or aryl group.
[0037] Each R
2 may be independently selected from an alkoxy group; an alkenyloxy group; an amido
group, such as an acetamido, a methylacetamido group, or benzamido group; an acyloxy
group such as acetoxy; an amino group; an aminoxy group; a hydroxyl group; a mercapto
group; an oximo group, and a ketoximo group. Alternatively, each R
2 may be an alkoxy group. Suitable alkoxy groups for R
2 include, but are not limited to, methoxy, ethoxy, propoxy, and butoxy.
[0038] Ingredient (G) may comprise an alkoxysilane exemplified by a dialkoxysilane, such
as a dialkyldialkoxysilane or a trialkoxysilane, such as an alkyltrialkoxysilane or
alkenyltrialkoxysilane, or partial or full hydrolysis products thereof, or another
combination thereof. Examples of suitable trialkoxysilanes include methyltrimethoxysilane,
methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane,
phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and a combination
thereof. Examples of alkoxysilane crosslinkers are disclosed in
U.S. Patents 4,962,076;
5,051,455; and
5,053,442.
[0039] Alternatively, ingredient (G) may comprise a dialkoxysilane selected from chloromethylmethyldimethoxysilane,
chloromethylmethyldiethoxysilane, dimethyldimethoxysilane, methyl-n-propyldimethoxysilane,
(2,2-dichloracyclopropyl)-methyldimethoxysilane, (2,2-difluorocyclopropyl)-methyldiethoxysilane,
(2,2-dichlorocyclopropyl)-methyldiethoxysilane, fluoromethyl-methyldiethoxysilane,
fluoromethyl-methyldimethoxysilane, or a combination thereof.
[0040] Alternatively, ingredient (G) may comprise a trialkoxysilane selected from methyltrimethoxysilane,
ethyltrimethoxysilane, propyltrimethoxysilane, isobutyltrimethoxysilane, cyclopentyltrimethoxysilane,
hexyltrimethoxysilane, phenyltrimethoxysilane, 2-ethyl-hexyltrimethoxysilane, 2,3-dimethylcyclohexyltrimethoxislane,
glycidoxypropyltrimethoxysilane, aminoethylaminopropyltrimethoxysilane, (ethylenediaminepropyl)trimethoxysilane,
3-methacryloxypropyltrimethoxysilane, chloromethyltrimethoxysilane, 3-chloropropyltrimethoxysilane,
trichlorophenyltrimethoxysilane, 3,3,3-trifluoropropyl trimethoxysilane, 4,4,4,3,3-pentafluorobutyltrimethoxysilane,
2,2-difluorocyclopropyltriethoxysilane, methyltriethoxysilane, cyclohexyltriethoxysilane,
chloromethyltriethoxysilane, tetrachlorophenyltriethoxysilane, fluoromethyltriethoxysilane,
methyltriisopropoxysilane, methyl-tris(methoxyethoxy)silane, n-propyl-tris(3-methoxyethoxy)silane,
phenyltris-(methoxyethoxy)silane, vinyltrimethoxysilane, vinyltriethoxysilane, or
a combination thereof.
[0041] Alternatively, ingredient (G) may comprise a tetraalkoxysilane selected from tetraethoxysilane,
tetrapropoxysilane, tetrabutoxysilane, or a combination thereof.
[0042] The amount of ingredient (G) depends on the specific crosslinker selected. However,
the amount of ingredient (G) may range from 0 parts to 5 parts, alternatively 0.1
parts to 5 parts, based on the weight of the composition. Ingredient (G) may be one
crosslinker. Alternatively, ingredient (G) may comprise two or more different crosslinkers.
[0043] Ingredient (G) may comprise an acyloxysilane, such as an acetoxysilane. Acetoxysilanes
include a tetraacetoxysilane, an organotriacetoxysilane, a diorganodiacetoxysilane,
or a combination thereof. The acetoxysilane may contain alkyl groups such as methyl,
ethyl, propyl, isopropyl, butyl, and tertiary butyl; alkenyl groups such as vinyl,
allyl, or hexenyl; aryl groups such as phenyl, tolyl, or xylyl; aralkyl groups such
as benzyl or 2-phenylethyl; and fluorinated alkyl groups such as 3,3,3-trifluoropropyl.
Alternatively, ingredient (G) may comprise organotriacetoxysilanes, for example mixtures
containing methyltriacetoxysilane and ethyltriacetoxysilane.
[0044] Alternatively, ingredient (G) may comprise a ketoximosilane. Examples of ketoximosilanes
for ingredient (G) include, but are not limited to, tetra(methylethylketoximo)silane,
methyl-tris-(methylethylketoximo)silane, vinyl-tris-(methylethylketoximo)silane, and
combinations thereof.
[0045] Alternatively, ingredient (G) may comprise a disilane of formula R
43Si-D-SiR
43, where R
4 and D are as described herein. Examples of such disilanes include bis(triethoxysilyl)hexane),
1,4-bis[trimethoxysilyl(ethyl)]benzene, and bis[3-(triethoxysilyl)propyl] tetrasulfide,
as described in,
e.
g.,
U.S. Patent 6,130,306.
Ingredient (H) Chemical Drying Agent
[0046] Alternatively, an amount of a crosslinker added to the composition in addition to
ingredient (G) may function as a chemical drying agent. Without wishing to be bound
by theory, it is thought that the chemical drying agent may be added to the dry part
of a multiple part composition to keep the composition free from water and to assist
in binding water coming from ingredient (D) after the parts of the composition are
mixed together. For example, alkoxysilanes suitable as drying agents include vinyltrimethoxysilane,
vinyltriethoxysilane, and combinations thereof.
[0047] The amount of ingredient (H) depends on the specific drying agent selected. However,
the amount of ingredient (H) may range from 0 parts to 5 parts, alternatively 0.1
parts to 0.5 parts. Ingredient (H) may be one chemical drying agent. Alternatively,
ingredient (H) may comprise two or more different chemical drying agents.
Ingredient (I) Adhesion Promoter
[0048] Ingredient (I) is an adhesion promoter. Ingredient (I) may be an organofunctional
silane other than ingredient (G). The organofunctional silane may have the general
formula R
3bSiR
4(4-b), where each R
3 is independently a monovalent organic group; each R
4 is an alkoxy group; and b is 0, 1, 2, or 3, alternatively b may be 0 or 1.
[0049] Alternatively, the adhesion promoter may comprise an organofunctional silane having
the formula R
5cR
6dSi(OR
5)
4-(c+d) where each R
5 is independently a substituted or unsubstituted, monovalent hydrocarbon group having
at least 3 carbon atoms and each R
6 contains at least one SiC bonded group having an adhesion-promoting group, such as
amino, epoxy, mercapto or acrylate groups, c has the value of 0 to 2 and d is either
1 or 2 and the sum of c+d is not greater than 3. The adhesion promoter can also be
a partial condensate of the above silane.
[0050] Examples of ingredient (I) include a trialkoxysilane such as gamma-aminopropyltriethoxysilane,
(ethylenediaminepropyl)trimethoxysilane, vinyltriethoxysilane, (methacryloxypropyl)trimethoxysilane,
vinyltrimethoxysilane; and a tetraalkoxysilane such as tetraethoxysilane; and combinations
thereof.
[0051] Alternatively, ingredient (I) may comprise a dialkoxysilane such as vinyl,methyl,dimethoxysilane;
vinyl,methyl,diethoxysilane; vinyl,ethyl,dimethoxysilane; vinyl,ethyl,diethoxysilane;
or a combination thereof.
[0052] Alternatively, ingredient (I) may comprise a trialkoxysilane selected from glycidoxypropyltrimethoxysilane,
aminoethylaminopropyltrimethoxysilane, (ethylenediaminepropyl)trimethoxysilane, 3-methacryloxypropyltrimethoxysilane,
vinyltrimethoxysilane, vinyltriethoxysilane, or a combination thereof.
[0053] Alternatively, ingredient (I) may comprise a tetraalkoxysilane selected from tetraethoxysilane,
tetrapropoxysilane, tetrabutoxysilane, or a combination thereof.
[0054] Alternatively, ingredient (I) may comprise a reaction product of an epoxy-functional
silane and an amino-functional silane, described above, and as exemplified by those
disclosed in
U.S. Patents 4,602,078 and
5,405,889. Alternatively, ingredient (I) may comprise a silatrane derivative derived from an
epoxy-functional silane and an amine compound as exemplified by those in
U.S. Patent 5,936,110.
[0055] Alternatively, ingredient (I) may comprise a disilane of formula R
43Si-D-SiR
43, where R
4 and D are as described above. Examples of such disilanes include bis(triethoxysilyl)hexane),
1,4-bis[trimethoxysilyl(ethyl)]benzene, and bis[3-(triethoxysilyl)propyl] tetrasulfide,
as described in,
e.
g.,
U.S. Patent 6,130,306.
[0056] The amount of ingredient (I) depends on the specific adhesion promoter selected.
One skilled in the art would recognize that certain examples for ingredients (G) and
(I) may have both crosslinking and adhesion promoting properties. One skilled in the
art would recognize that the amount of ingredient (I) added to the composition is
in addition to the amount of ingredient (G), and that when ingredient (I) is added,
the adhesion promoter selected may be the same as or different from the crosslinker.
However, the amount of ingredient (I) may range from 0 parts to 5parts, alternatively
0 parts to 2 parts, and alternatively 0.5 parts to 1.5 parts, based on the weight
of the composition. Ingredient (I) may be one adhesion promoter. Alternatively, ingredient
(I) may comprise two or more different adhesion promoters.
[0057] Organofunctional alkoxysilane crosslinkers and adhesion promoters are known in the
art and commercially available. For example, vinyltriethoxysilane, vinyltrimethoxysilane,
phenyltrimethoxysilane, tetraethoxysilane, isobutyltrimethoxysilane, (ethylenediaminepropyl)trimethoxysilane,
and (methacryloxypropyl)trimethoxysilane are available from Dow Corning Corporation
of Midland, Michigan, U.S.A. Aminopropyltriethoxysilane and gamma-isocyanopropyltriethoxysilane
are available from under the designation SILQUEST® (A-1100 and A-1310, respectively)
from Momentive Performance Materials, 187 Danbury Road, Wilton, CT USA.
[0058] One skilled in the art would recognize when selecting ingredients (G), (H), and (I)
that there may be overlap between crosslinker (affecting the physical properties of
the cured product), adhesion promoter (affecting the adhesion of the cured product),
and chemical drying agent (affecting shelf-stability). One skilled in the art would
be able to distinguish among and select ingredients (G), (H), and/or (I) based on
various factors including the intended use of the composition and whether the composition
will be prepared as a one-part or multiple-part composition.
Ingredient (J) Microcrystalline Wax
[0059] Ingredient (J) is a microcrystalline wax that is a solid at 25 °C (wax). The melting
point may be selected such that the wax has a melting point at the low end of the
desired application temperature range. For example, when the composition will be used
in an IG unit, the wax may have a melting point ranging from 80 to 100 °C. Without
wishing to be bound by theory, it is thought that ingredient (J) acts as a process
aid that improves flow properties while allowing rapid green strength development
(
i.
e., a strong increase in viscosity, corresponding to increase in the load carrying
capability of a seal prepared from the composition, with a temperature drop) upon
cooling the composition a few degrees, for example, after the composition is applied
to a substrate. Without wishing to be bound by theory, it is thought that incorporation
of wax may also facilitate incorporation of fillers, compounding and deairing (during
production of the composition), and mixing (static or dynamic mixing during application
of both parts of a two-part composition). It is thought that the wax, when molten,
serves as a process aid, substantially easing the incorporation of filler in the sealant
during compounding, the compounding process itself, as well as the deairing step.
The wax, with a melt temperature below 100 °C, may facilitate mixing of the two parts
of a two part sealant composition before application, even in a simple static mixer.
The wax may also facilitate application of the sealant at temperatures ranging from
80 °C to 110 °C, alternatively 90 °C to 100 °C with good rheology.
[0060] Waxes suitable for use as ingredient (J) may be non-polar hydrocarbons. The waxes
may have branched structures, cyclic structures, or combinations thereof. For example,
petroleum microcrystalline waxes are available from Strahl & Pitsch, Inc., of West
Babylon, NY, U.S.A. and include SP 96 (melting point ranging from 62 °C to 69 °C).
SP 18 (melting point ranging from 73 °C to 80 °C), SP 19 (melting point ranging from
76 °C to 83 °C), SP 26 (melting point ranging from 76 °C to 83 °C), SP 60 (melting
point ranging from 79 °C to 85 °C), SP 617 (melting point ranging from 88 °C to 93
°C), SP 89 (melting point ranging from 90 °C to 95 °C), and SP 624 (melting point
ranging from 90 °C to 95 °C). Other petroleum microcrystalline waxes include waxes
marketed under the trademark Multiwax® by Crompton Corporation of Petrolia, Pennsylvania,
U.S.A. These waxes include 180-W, which comprises saturated branched and cyclic non-polar
hydrocarbons and has melting point ranging from 79 °C to 87 °C; Multiwax® W-445, which
comprises saturated branched and cyclic non-polar hydrocarbons, and has melting point
ranging from 76 °C to 83 °C; and Multiwax® W-835, which comprises saturated branched
and cyclic non-polar hydrocarbons, and has melting point ranging from 73 °C to 80
°C.
[0061] The amount of ingredient (J) depends on various factors including the specific wax
selected and the selections of ingredients (C) and (D) and ingredient (E), if present.
However, the amount of ingredient (J) may range from 0 parts to 20 parts, alternatively
1 parts to 15 parts, and alternatively 1 parts to 5 parts based on the weight of the
composition. Ingredient (J) may be one wax. Alternatively, ingredient (J) may comprise
two or more different waxes.
Ingredient (K) Anti-aging Additive
[0062] Ingredient (K) is an anti-aging additive. Ingredient (K) may comprise an antioxidant,
a UV absorber, a UV stabilizer, a heat stabilizer, or a combination thereof. Examples
of UV absorbers include phenol, 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-, branched
and linear (TINUVIN® 571). Examples of UV stabilizers include bis(1,2,2,6,6-pentamethyl-4-piperidyl)
sebacate; methyl 1,2,2,6,6-pentamethyl-4-piperidyl\ sebacate; and a combination thereof
(TINUVIN® 272). These TINUVIN® additives are commercially available from Ciba Specialty
Chemicals of Tarrytown, NY, U.S.A. Suitable antioxidants are known in the art and
commercially available. Suitable antioxidants include phenolic antioxidants and combinations
of phenolic antioxidants with stabilizers. Phenolic antioxidants include fully sterically
hindered phenols and partially hindered phenols. Stabilizers include organophosphorous
derivatives such as trivalent organophosphorous compound, phosphites, phosphonates,
and a combination thereof; thiosynergists such as organosulfur compounds including
sulfides, dialkyldithiocarbamate, dithiodipropionates, and a combination thereof;
and sterically hindered amines such as tetramethyl-piperidine derivatives. Suitable
antioxidants and stabilizers are disclosed in
Zweifel, Hans, "Effect of Stabilization of Polypropylene During Processing and Its
Influence on Long-Term Behavior under Thermal Stress," Polymer Durability, Ciba-Geigy
AG, Additives Division, CH-4002, Basel, Switzerland, American Chemical Society, vol.
25, pp. 375-396, 1996. Suitable phenolic antioxidants include vitamin E and IRGANOX® 1010 from Ciba Specialty
Chemicals, U.S.A. IRGANOX® 1010 comprises pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate).
Oligomeric (higher molecular weight) stabilizers may be used to minimize potential
for chemical fogging of IG units and migration. Example of an oligomeric antioxidant
stabilizer (specifically, hindered amine light stabilizer (HALS)) is Ciba Tinuvin
622 is a dimethylester of butanedioic acid copolymerized with 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine
ethanol.
[0063] The amount of ingredient (K) depends on the specific anti-aging additive selected.
However, the amount of ingredient (K) may range from 0 parts to 5 parts, alternatively
0.5 parts to 3 parts, based on the weight of the composition. Ingredient (K) may be
one anti-aging additive. Alternatively, ingredient (K) may comprise two or more different
anti-aging additives.
Ingredient (L) Tackifying Agent
[0064] Suitable tackifying agents are known in the art. For example, the tackifying agent
may comprise an aliphatic hydrocarbon resin such as a hydrogenated polyolefin having
6 to 20 carbon atoms, a hydrogenated terpene resin, a rosin ester, a hydrogenated
rosin glycerol ester, or a combination thereof. Tackifying agents are commercially
available. Aliphatic hydrocarbon resins are exemplified by ESCOREZ 1102, 1304, 1310,
1315, and 5600 from Exxon Chemical and Eastotac resins from Eastman, such as Eastotac
H-100 having a ring and ball softening point of 100 °C, Eastotac H-115E having a ring
and ball softening point of 115 °C, and Eastotac H-130L having a ring and ball softening
point of 130 °C. Hydrogenated terpene resins are exemplified by Arkon P 100 from Arakawa
Chemicals and Wingtack 95 from Goodyear. Hydrogenated rosin glycerol esters are exemplified
by Staybelite Ester 10 and Foral from Hercules. Examples of commercially available
polyterpenes include Piccolyte A125 from Hercules. Examples of aliphatic/aromatic
or cycloaliphatic/aromatic resins include ECR 149B or ECR 179A from Exxon Chemical.
[0065] In addition, up to 20 parts by weight, alternatively 10 parts by weight, based on
the weight of ingredient (L) of a solid tackifying agent (
i.
e., a tackifying agent having a ring and ball softening point above 25 °C), which is
compatible with ingredients (A) and (F). Suitable tackifying agents include any compatible
resins or mixtures thereof such as (1) natural or modified rosins such, for example,
as gum rosin, wood rosin, tall-oil rosin, distilled rosin, hydrogenated rosin, dimerized
rosin, and polymerized rosin; (2) glycerol and pentaerythritol esters of natural or
modified rosins, such, for example as the glycerol ester of pale, wood rosin, the
glycerol ester of hydrogenated rosin, the glycerol ester of polymerized rosin, the
pentaerythritol ester of hydrogenated rosin, and the phenolic-modified pentaerythritol
ester of rosin; (3) copolymers and terpolymers of natural terpenes,
e.
g., styrene/terpene and alpha methyl styrene/terpene; (4) polyterpene resins having
a softening point, as determined by ASTM method E28,58T, ranging from 60 °C to 150
°C; the latter polyterpene resins generally resulting from the polymerization of terpene
hydrocarbons, such as the bicyclic monoterpene known as pinene, in the presence of
Friedel-Crafts catalysts at moderately low temperatures; also included are the hydrogenated
polyterpene resins; (5) phenolic modified terpene resins and hydrogenated derivatives
thereof, for example, as the resin product resulting from the condensation, in an
acidic medium, of a bicyclic terpene and phenol; (6) aliphatic petroleum hydrocarbon
resins having a ring and ball softening point ranging from 60 °C to 135 °C; the latter
resins resulting from the polymerization of monomers consisting of primarily of olefins
and diolefins; also included are the hydrogenated aliphatic petroleum hydrocarbon
resins; (7) alicyclic petroleum hydrocarbon resins and the hydrogenated derivatives
thereof; and (8) aliphatic/ aromatic or cycloaliphatic/aromatic copolymers and their
hydrogenated derivatives.
[0066] The amount of ingredient (L) depends on various factors including the specific tackifying
agent selected and the selection of ingredient (I). However, the amount of ingredient
(L) may range from 0 parts to 20 parts based on the weight of the composition. Ingredient
(L) may be one tackifying agent. Alternatively, ingredient (L) may comprise two or
more different tackifying agents.
Preparation of the Composition
[0067] The process may be either a batch compounding process or a continuous compounding
process. A continuous compounding process may allow for better control of stripping
conditions and may minimize duration of heat exposure of the composition, thereby
improving control of the water content of the composition. Without wishing to be bound
by theory, it is thought that improving control of the water content allows for improved
curing of the composition.
[0068] The composition of this invention may be formulated as a one-part composition or
a multiple-part composition, such as a two-part composition. A one-part composition
may be prepared by a process comprising mixing the ingredients under shear. The ingredients
may be mixed under vacuum or a dry inert gas, or both. The ingredients may be mixed
under ambient or elevated temperature, or a combination thereof.
[0069] A one-part composition may be prepared by heating ingredients (A) and (F), and ingredient
(J), if present, before adding ingredients (D) and (C). After combining these ingredients
at elevated temperature, ingredient (B) and additional ingredients such as (E), (G),
(H), (I), (K), and (L) if any, may be added. Alternatively, ingredients (E) and (J)
may be combined, and thereafter ingredients (A), (F), (G), (E), (H), (I), (C), and
(B) may then be added.
[0070] Alternatively, the composition may be prepared as a multiple-part composition, such
as the two-part composition described below. One skilled in the art would recognize
how to prepare a multiple-part composition by storing ingredient (B) the condensation
catalyst and ingredient (D) the water release agent in separate parts. An exemplary
two-part composition comprises a wet (water containing) part and a dry part. The wet
part may be prepared by mixing under shear ingredients comprising (F) a non-reactive,
elastomeric, organic polymer, and (D) a water release agent, and one or more of the
following optional ingredients: (J) wax, (L) tackifying agent, (E) filler such as
reinforcing filler (
e.
g., carbon black), extending filler, or both.
[0071] The dry part may be prepared by mixing under shear ingredients comprising (A) a moisture-curable,
silane-functional, elastomeric, organic polymer, (F) a non-reactive, elastomeric,
organic polymer, (B) a condensation catalyst; (C) a drying agent, and one or more
of the following optional ingredients: (J) wax, (L) tackifying agent, (G) crosslinker
(H) chemical drying agent, (K) stabilizer, and (I) adhesion promoter.
[0072] Alternatively, the wet part may be prepared by mixing under shear ingredients comprising
(A) a moisture-curable, silane-functional, elastomeric, organic polymer, (F) a non-reactive,
elastomeric, organic polymer, and (D) a water release agent. When the wet part comprises
the ingredient (A) care must be taken that none of the other ingredients in the wet
part unintentionally may act as a condensation catalyst. In this case, consideration
should to be given to the nature of the water release agent (D). The dry part may
be prepared by mixing under shear ingredients comprising (A) a moisture-curable, silane-functional,
elastomeric, organic polymer and (B) a condensation catalyst, (C) a physical drying
agent, optionally (G) a crosslinker, optionally (H) a chemical drying agent, optionally
(I) an adhesion promoter, and. Each of the wet part and the dry part may optionally
further comprise one or more additional ingredients selected from, (F) a non-reactive,
elastomeric, organic polymer, (J) a microcrystalline wax, which is a solid at 25 °C,
(K) an anti-aging additive, and (L) a tackifying agent.
The process conditions of shear and heating are selected such that an amount of water
sufficient to cure the composition remains in ingredient (D) the water release agent
during compounding operation to prepare the composition. To achieve sufficient homogeneous
mixing during this operation (especially in terms of the polymers and the powder components,
e.
g., drying agent and water release agent, one skilled in the art may choose a compounding
temperature close to the application temperature, so that the polymer components are
sufficiently liquid to allow efficient incorporation of the powder components. However,
because of the mechanical shear required for this operation, the actual compounding
temperature often will be substantially above the application temperature. For instance,
when manufacturing the composition with a twin-screw compounder, temperature may run
20 to 30 °C above the application temperature (
e.
g., 110 to 120 °C when the composition will be applied at 80 to 100 °C in an IG unit)
and sometimes as high as 100 to 110 °C above the application temperature. While the
composition is not exposed to this temperature for prolonged periods of time, the
'bound' water still needs to survive this compounding step. Without wishing to be
bound by theory, it is thought that ingredient (D) is a water release agent in which
the water is sufficiently tightly bound in order for sufficient amounts of water to
survive the compounding step, while at the same time, the water is bound insufficiently
tightly to prevent a sufficient quantity of water to cure the composition at the application
temperature to initiate cure.
Method of Use
[0073] Ingredient (A) allows the composition to cure via condensation reaction. Ingredients
(A) and (F) are considered low permeability polymers,
i.
e., these polymers minimize moisture permeability and gas permeability of the cured
product of the composition. Therefore, ingredient (D) a water release agent that releases
water over an application temperature range is included in the composition to cure
the composition. In a two-part composition, addition of a water release agent such
as precipitated CaCO
3 to one part of the composition is a suitable means of inducing cure upon mixing of
the two parts when the composition is heated to a temperature that releases a sufficient
amount of water from ingredient (D). Since the composition is exposed to the application
temperature in the application equipment only for a limited duration, the water release
agent may be chosen such that it releases a sufficient amount of water to induce sufficiently
fast cure, even after the composition has cooled down again after its application.
For instance, when the composition is mixed at room temperature or below 40 to 60
°C, the composition may cure too slowly for the industrial manufacturing process of
IG units.
[0074] The composition of this invention may be used in IG applications. Figures 1 (single-seal)
and 2 (dual-seal) are cross sectional views showing portions of IG units. Each IG
unit comprises a first glass pane 101, a second glass pane 102 spaced a distance from
the first glass pane 101. In figure 1, a cured product 103 of the composition described
above is interposed in the interpane space between the first glass pane 101 and the
second glass pane 102. The cured product 103 may act as an integrated edge-seal,
i.
e., acting as a water vapor barrier, a gas barrier, a sealant between the panes, a
spacer, an adhesive, and a desiccant matrix. Figure 2 shows the use of the cured product
103 of the composition described above as a primary sealant. A secondary sealant 104,
such as a polysulfide, polyurethane, or silicone, is adhered to the primary sealant
and the glass panes 101, 102. In the case of dual-seal (figure 2) the cured product
103 may act as an integrated edge-seal,
i.
e., acting as a water vapor barrier, a gas barrier, a sealant between the panes, a
spacer, an adhesive, and a desiccant matrix. The secondary sealant 104 then further
supports the sealing and bonding (adhesive) function of the cured product 103.
[0075] The process of applying the two-part composition may comprise melting the two parts
and feeding them by suitable means (
e.
g., conventional equipment such as a hot melt pump or extruder) into a heated static
or dynamic mixer and from there via a heated hose to an application nozzle. The process
for applying the sealant from the nozzle onto the glass to form the edge-seal and
for making the IG unit offers the advantages of employing the same or similar equipment
currently used for making conventional TPS® IG units, with the exception that the
equipment may be modified to handle two parts (dual feeds) when a two part composition
is used, and the composition described above also allows manufacture of single seals.
One process used to make TPS® units comprises applying the composition as a seal filament
around the perimeter of a first glass pane, moving a second glass pane in parallel
position in close proximity to the first glass pane, optionally filling the inter-pane
volume with a gas (such as argon), and closing the IG unit by pressing the second
glass pane against the filament seal formed on the first glass pane (see, for instance,
EP 0,805,254 B1,
WO 95/11,363,
WO 96/09,456). Alternatively, the glass panes may be held in a parallel, spaced position and the
composition extruded between the glass panes (see
WO 90/02,696), or the composition may be first extruded onto a support to which the composition
adheres less well than to glass, then the composition is transferred from the support
onto one glass pane, both glass panes are made to coincide and are then pressed together
(see
WO 95/11,364).
[0076] The IG unit may be prepared by a process comprising i) bringing the first glass pane
101 and the second glass pane 102 into a parallel position spaced apart by an interpane
space, ii) applying the composition described above into the interpane space along
the perimeter of the first glass pane 101 and the second glass pane 102, and iii)
curing the composition.
[0077] Alternatively, the IG unit may be prepared by a process comprising: i) applying the
composition described above as a filament seal around the perimeter of the first glass
pane 101, ii) moving the second glass pane 102 into a parallel position to the first
glass pane 101 such that the first glass pane 101 and the second glass pane 102 are
spaced apart by an interpane space, optionally iii) filling the interpane space with
a gas such as argon or dry air, iv) pressing the second glass pane 102 against the
filament seal formed on the first glass pane 101, and v) curing the composition.
[0078] Alternatively, the IG unit may be prepared by a process comprising: i) applying a
composition described above as a filament seal onto a support to which the composition
adheres less well than to glass, ii) transferring the filament seal from the support
onto the first glass pane 101, iii) pressing the first glass pane 101 and the second
glass pane 102 together in a parallel position, and iv) curing the composition.
[0079] In any of the processes for preparing the IG unit, a one-part or a two-part composition
described above may be used. When a two-part composition is used, the two parts may
be mixed shortly before process step i) or process step ii). These processes for preparing
the IG unit may offer the advantage that curing the composition may be performed in
the absence of atmospheric moisture. For purposes of this application, "absence of
atmospheric moisture" means that any amount of moisture present in the ambient atmosphere
is insufficient to cure of this invention within a time period of 3 to 4 weeks. Curing
may be performed by heating the composition to the application temperature range,
hereby releasing water from ingredient (D). Curing may be performed during or after
application of the composition to a glass pane. In the processes for preparing the
IG unit, applying the composition may be performed at a temperature ranging from 80
°C to 140 °C.
Curing may be performed at room temperature for 3 to 4 weeks to reach 80 % of the
final properties.
EXAMPLES
[0080] The following examples are included to demonstrate the invention to those of ordinary
skill in the art. However, those of skill in the art should, in light of the present
disclosure, appreciate that many changes can be made in the specific embodiments which
are disclosed and still obtain a like or similar result without departing from the
spirit and scope of the invention set forth in the claims. All amounts, ratios, and
percentages are by weight unless otherwise indicated. The ingredients described in
Table 1 were used in the following examples.
Table 1- Ingredient Information
Ingred. |
Chemical Name |
Physical Properties, viscosity units are mPa·s |
Commercial Source |
(A1) |
A silylated copolymer comprising a reaction product of isobutylene and paramethylstyrene
with methylvinyl dimethoxysilane. |
The silylated copolymer is a random polyisobutylene-p-methylstyrene copolymer grafted
with vinyldimethoxysilane. The molecular weight of the polyisobutylene-p-methylstyrene
ranges from 63,000 to 870,000 before grafting. After grafting, the molecular weight
ranges from 28,000 to 33,000. Viscosity is 43600 @ 150 °C. |
Dow Corning Corporation, Midland, Michigan, U.S.A. |
(B1) |
Di-(n-butyl)tin bis-ketonate |
|
Acima Chemical Industries Metatin 740 |
(B2) |
Di-n-Butyltin-di-Laurate (DBTDL) |
|
Acima Chemical Industries Metatin® 712 |
(C1) |
3Å zeolite molecular sieve (dry) |
Potassium aluminosilicate |
UOP Molsiv 3A |
(C2) |
4Å molecular sieve (dry) |
Sodium aluminosilicate (note: Alflexil 100 was dried at 260 C for 2 hours to desorb
water) |
Alflexil 100 from A. E. Fischer Chemie GmbH & Co. KG of Wiesbaden, Germany |
(C3) |
3Å zeolite molecular sieve (dry) |
Potassium aluminosilicate |
Grace Davidson, Sylosiv 3A |
(D1) |
precipitated CaCO3 treated with fatty acid (i.e., stearic acid) |
Mean particle diameter: < 0.1 µm, specific surface (BET): 20 m2/g, coating content: 2.7 wt %, |
Solvay Chemicals Winnofil SPM |
(D2) |
Hydrated 4Å molecular sieve |
Saturated sodium aluminosilicate |
Ineos Doucil 4A from Ineos Silicas |
(D3) |
Hydrated 4Å molecular sieve |
Saturated sodium aluminosilicate |
Alflexil 100 from A. E. Fischer Chemie GmbH & Co. KG |
(E1) |
Amorphous carbon black |
Average particle size 0.05 µm, specific surface area: 44 m2/g, Oil absorption: 120 (g/100g) |
Elementis Superjet Carbon Black LB-1011 or WMS 1011 |
(E2) |
Fine particle size, wet ground, ammonium stearate treated marble |
Mean particle diameter: 3 um, surface area: 2 m2/g, treatment level: ∼ 1 wt % |
Imerys Marble Inc. Gama-Sperse® CS-11 |
(E3) |
Untreated fumed silica |
Surface area: 108 m2/g |
Cabot Corporation, Cab-O-Sil.L-90 |
(F1) |
Polyisobutylene |
Average Mn is 950 Viscosity is 110 @ 120 °C |
Soltex PB-24 |
(F2) |
Polyisobutylene |
Average Mn is 36,000 Viscosity is 40,000 @ 150°C |
BASF Oppanol B-10 |
(F3) |
Polyisobutylene |
Average Mn is 51,000 Viscosity is 150,000 @ 150°C |
BASF Oppanol B-12 |
(F4) |
Polyisobutylene |
Average Mn is 75,000 Viscosity is 700,000 @ 150 °C |
BASF Oppanol B-15 |
(F5) |
Polyolefin Plastomer |
Density of 0.874 g/ml, viscosity of 17,000 cps at 350° F (177°C) (by Brookfield spindle
#31), and approximate melt index of 500. |
Dow Chemical Company, Affinity GA 1950 POP |
(F6) |
Styrene/ethylene/propylene/styrene block copolymer (SEPS) |
Density of 0.88 g/ml, Styrene content of 13 wt%, pellets |
Kuraray America, Inc., Septon 2063 |
(G1) |
Vinyl triethoxysilane |
|
Dow Corning Corporation, Midland, Michigan, U.S.A. |
(G2) |
Vinyl trimethoxysilane |
Bp 123°C |
Dow Corning Corporation, Midland, Michigan, U.S.A. |
(G3) |
Phenyltrimethoxysilane |
|
Dow Corning Corporation, Midland, Michigan, U.S.A. |
(I1) |
Tetraethylortho silicate (TEOS) |
|
Dow Corning Corporation. Midland, Michigan, U.S.A. |
(I2) |
Gamma-Aminopropyltriethoxysilane |
|
GE Silicones Silquest® A-1100 Silane |
(I3) |
Methacryloxypropyl trimethoxysilane |
|
Dow Corning Corporation, Midland, Michigan, U.S.A. Z-6030 |
(I4) |
Ethylenediaminopropyltrimethoxy-silane |
N2NC2H4NHC3H6-Si(OCH3)3 |
Dow Corning Corporation, Midland, Michigan, U.S.A. Z-6020 |
(I5) |
(Gamma-isocyanopropyl)triethoxysilane |
|
GE Silicones Silquest® A-1310 Silane |
(J1) |
White, highly refined, high molecular weight microcrystalline petroleum wax; consists
of saturated branched and cyclic non-polar hydrocarbons. |
Melting Point, °C 79.4-86.7 ASTM D127 |
Crompton Witco Multiwax 180-W |
(J2) |
microcrystalline petroleum wax |
Melting Point ASTM D 127 88.3-92.7°C |
Strahl & Pitsch S&P 617 |
(K1) |
Mixture of 80 % bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate and 20 % methyl(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate
(general-purpose liquid hindered-amine light stabilizer (HALS)) |
|
Ciba® Tinuvin® 292 |
(K2) |
2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol, branched and linear (benzotriazole
type UV absorber) |
|
Ciba® Tinuvin 571 |
(L1) |
Hydrogenated hydrocarbon tackifying resin made up of hydrogenated hydrocarbons having
6 to 20 carbon atoms |
Ring and Ball softening point ranging from 95 to 105 °C Average Mn is 450 |
Eastman Eastotac H 1 00 |
Reference Example 1 - Property evaluation methods
Ares Rheometer
[0081] The Ares rheometer was used in dynamic shear for cure profiling using the complex
modulus components, and for viscosity and modulus build with time and temperature.
[0082] When doing a cure profiling, conditions used were geometry of 25 mm parallel plates,
a frequency of 1 Hz and a temperature of 95 °C. The software determined the point
in time when G', storage modulus, crossed G", the loss modulus,
i.
e., G'=G" at this point.
This time was then added to the time it took to get the material in the instrument
and that overall time was considered the onset of cure. This point is often referred
to as the gel point (
Melt Rheology and Its Role in Plastics Processing, Dealy, J and Wissbrun, K, 1990
pg. 420) and a finite measurable point for the onset of cure.
[0083] The rheometer was also used to determine the extent of cure by placing cured samples
between the plates taking care not to overload the weigh cells or transducer and then
measuring G' values using 25 mm parallel plates and a frequency of 1 Hz at the desired
temperatures.
[0084] Temperature sweeps of the samples were also done right after mix and days later to
determine the solidification point and the effect of temperature on the viscosity
of the fresh mixed material allowing for rheological profiling for mixing and clean
out purposes. These were done with 25 mm parallel plates or 10 mm parallel plates
and a frequency of 1 Hz for a temperature range from -20 °C to 145 °C depending on
samples being tested.
Durometer - hardness of the material
[0085] The hardness of material was measured through a variation of ASTM D 2240. A Durometer
Type A from Shore Instrument and Manufacturing with a Conveloader was used for testing
material. Materials tested were generally 3 mm thick. In a separate set of tests it
was shown that 3 mm thickness was sufficient for achieving reproducible results when
placing the samples consistently on the Conveloader surface. As with any viscoelastic
material, the samples showed a dependence of durometer measurement on the time of
contact between the durometer pin and surface of the sample. This effect is believed
to be primarily due to the wax contained in the sample. Samples were placed on the
conveloader surface and the durometer head was allowed to fall at its predetermined
rate due to the 1 kg weight. Due to the different nature of this sample, upon initial
contact of the durometer needle with the surface a timer was started for 5 seconds.
Shortly there after a high reading was seen on the instrument and recorded as initial
value. Then after the 5 seconds had passed a second reading on the instrument was
recorded as the 5 second value. A minimum of 3 readings was taken and the median value
was reported of both the initial value and the 5 second value. In the cases where
wax was in the sample, the durometer head generally left a hole that only returned
to its original shape after heating the slab of sample, and the slab was cured prior
to testing.
Adhesive (T/A) joint configurations
[0086] Adhesive (T/A) joint configurations were done to test adhesion between two glass
substrates. The general assembly of the T/A joints with the compositions were done
with molten sample and forced into the joints with the best void free sample after
the sample was either mixed via a Hauschild mixer at 97 °C, then deaired, and mixed
again via a Hauschild mixer at 97 °C, or the sample was prepared via the method outlined
in the two part mixing by volume in the examples below. Dispensing and assembly of
the T/A joints were done in a 95 °C hot workspace and/or high air flow oven that allowed
material to be pressed or dispensed into the joint configuration in a manner that
no air was trapped in the material. After assemblies were filled, they were allowed
to cool to room temperature, but assemblies were often removed from the clamps anytime
after they were cooled and green strength was obtained. Due to the adhesive nature
of the samples, a piece of release liner was placed between the Teflon spacer and
the sample for easy release of the sample from the assembly.
Either upon curing or complete cooling, this release liner could then be removed.
It was found enhanced release of the liner was possible when further cooling of the
assemblies were done in a freezer and a fast pull of the release liner was done to
remove it.
[0087] Adhesive (T/A) joint configurations with the commercial grade TPS material (non-reactive
thermoplastic spacer/seal - comparative example 1) were also done, but assembly was
slightly different by using pre-extruded material to create the 2"x 0.5"x0.5" configuration.
In this case three pieces of TPS were placed together. The TPS material (Koemmerling
Koedimelt® TPS) was pressed into the configuration jig and then was heated at 120
°C for 30 minutes. The configuration was removed from the oven and the TPS material
pressed into the glass configuration using an Arbor Press removing voids and ensuring
good contact between the TPS and glass. The assembly was tightened, allowed to cool
overnight and then disassembled and excess TPS trimmed away prior to testing sample
since no cure time was necessary.
Swell Gel
[0088] Resistance to a solvent, toluene, commonly used to dissolve the materials in the
uncured state was used to determine completion of cure. A sample was allowed to cure
for 5 days after which a known weight was placed into a 1 ounce vial with toluene.
Every few days the toluene was replaced with fresh toluene. After one week the sample
was removed decanting off the bulk of solvent and then placing it into a pre-weighed
dish for drying. The amount left after drying to a stable level was measured and compared
to the weight of original sample to determine the amount of cured network of polymer,
fillers and other curable materials.
Solvent Resistance
[0089] A small piece of sample, nominally 64 mm
2 by 3 mm thick, was placed in a 1 ounce vial and covered with toluene to see if the
sample would dissolve. After a short time it was found samples had differing levels
of solvation and a rating system was devised according to how black the mixture became
due to the carbon black being freed upon polymer solvation.
The rating system suggested a 0 value the "best" with material not solvated and the
solvent staying clear, not turning black. Varying levels of gray to black were determined
with 1 to 10 and 10 being a sample that is totally dissolved. These ratings were done
at set intervals to differentiate cure and extent of cure with different compositions
enabling multiple composition interactions to be differentiated in a shorter time.
An evaluation value was determined after flipping the vial once and observing the
color of the toluene.
Elastic Recovery
[0090] Elastic recovery was investigated using the idea of ASTM C 736-00, but changed for
use with the samples looking to understand bulk properties over adhesive qualities
when conducted at 95 °C. The test was done on cured elastomer and TPS (comparative
example).
In all cases, the sample was pressed or cast into sheets. These sheets were then die-cut
("dogbone" shaped specimens) to have a region of smaller cross sectional area and
one of larger for attaching / clamping. In this case a die for cutting tensile samples
was used in conjunction with an Arbor press and then the bar was cut in half to be
used in the test. Test specimens were made for vertical testing in a 95 °C high air
flow oven. A test sample was held in place with a mechanical clamp and masking tape
between the sample and clamp to help dissipate the clamping pressure on the samples
to prevent the mechanical clamp from crushing the sample causing premature failure
at the attachment point. The original distance of the sample was measured and recorded
as the original length. Clamped samples were placed in a high airflow oven, and samples
alone were tested for heat resistance under the weight of the sample itself for a
predetermined time, sometimes 20 hours. The samples were removed from the oven and
let hang vertically until cool, where samples were again measured and recorded. Then
these samples had a second clamp and weight attached. The weight was predetermined
based on the cross-sectional area and the amount to provide a given force. This set
up was then placed back in the 95 °C oven vertically for a set amount of time and
then removed for cooling while in a vertical position. Upon cooling, the length was
again measured. This number was used to derive a percent elongation as compared to
the original length. Then the second clamp or bottom one was removed, and the sample
was placed back in the oven for a 10 minute recovery time. Upon removal and cooling
the sample length was again measured and then a comparison of this returned length
could be done to the stretched length for a percent recovery or elastic recovery.
Deadload testing
[0091] Deadload testing was done looking for the sample's ability to support a given weight
for an extended period of time. Sample preparation was done in a similar manner to
the elastic recovery just described, but clamped at both ends from the beginning.
Length measurements are also done throughout the testing for elastic recovery measurements
on these samples also. The test was done on cured samples. In all cases, samples were
pressed or cast into sheets and allowed to cure for a given period of time, and in
some cases a post cure was done for added strength. The samples were die-cut from
a tensile die using an Arbor press and the region of smaller cross sectional area
was used to determine the weight necessary to deliver the desired applied force, 2
psi and 3.45 psi, nominally 18.2 grams and 31.4 grams, respectively. Samples were
set up with mechanical clamps and masking tape between the material and clamp to help
dissipate the clamping pressure at both end of the sample. The straight region of
the tensile bar was 34 mm between radii and this was the area judged during the stretching
for elastic recovery. In all cases, the 2 psi test was done on a sample first for
a time period of 3 hours in a high air flow oven at 95 °C after which time the samples
were removed, cooled and measured. The weights and the bottom clamp were then removed
and the samples were placed back in the high air flow oven at 95 °C vertically for
1 hour and then removed for cooling and measurement to determine an elastic recovery.
Samples were then loaded for the 3.45 psi testing and placed in the oven for 17 hours
(overnight); after which time the samples were removed, cooled and measured. The weights
and bottom clamp were then removed and the samples were placed back in the high air
flow oven at 95 °C vertically for 1 hour and then removed for cooling and measurement
to determine an elastic recovery.
Moisture Analysis
[0092] The water content of raw materials was determined via a method of thermogravimetry
using a Mark 4 Moisture Analyzer set at 150 °C. This device measures the weight loss
of the filler or other substances and does make the assumption that the only substance
coming off is water and in this case should be a valid assumption being on the neat
ingredient (D).
Depth of Cure
[0093] In the samples, if not enough internal moisture was present, then only cure from
an exposed surface would occur. Using materials after 7 and 6 days of cure, a solvent
resistance test was done with samples immersed in toluene for one day. Then the samples
were removed and the toluene was allowed to evaporate to determine what was left.
This type of test would be similar to that left behind in a typical swell gel test
if weight measurements were done. However, an indication of sample cure could be seen
from the thickness of the film left behind after the toluene was evaporated. In the
case of very little material left behind, it suggests very little cured network and
most likely just from the surface exposed.
While samples that had enough moisture to cure the bulk of the material and be resistant
to toluene were very thick and suggest a suitable moisture source was available to
make a cured network.
Lap Shear testing
[0094] The lap shear samples were prepared according to ASTM D3164-97 using 1" x 3" glass
panels and applying a heated sample in a heated area to create a 0.25 inch bondline.
Samples were allowed to cure for a predetermined time, and then an Alliance RT/5 Tensiometer
was used to pull the samples and obtain a lap shear value. Samples were applied and
pressed between two glass panels in a 95 °C workspace, allowed to cool, and then tested.
These values were all measured at room temperature or placed in a -31 °C freezer 30
minutes prior to testing and tested immediately after removal from the freezer.
Flexibility
[0095] The mandrel bend test, ASTM 3111 was done at -30 °C. The mandrel and samples were
placed in a freezer at -30 °C for 30 minutes. The size of each sample was 8 mm x 22
mm and 3 mm thick. Upon removal of samples and rod, the samples were immediately bent
over the rod and inspected for any cracking or change. Any signs of cracking or change
were recorded.
Frost Point Testing
[0096] Using ASTM E546-88 Standard Test Method for Frost Point of Sealed Insulating Glass
(IG) units as a guide a laboratory procedure was created for testing the Frost Point.
The test was preformed on small laboratory unit (3"x6"). The unit was made with a
sample that was mixed in a 1 to 1 ratio by volume using a MixPac S-50 hand held gun
and static mixer maintained at 94 °C in a high air flow oven. The sample was dispensed
in such a way to create an entire circle, oval or rectangular shape onto one glass
panel and then a second glass panel was placed on top of the dispensed sample creating
a sealed environment. The sample then desiccated the space between the glass panels.
The unit was allowed to cure at room temperature for 4 days. After cure, the laboratory
IG unit was subjected to dry ice directly on one side of the IG unit for 10 minutes.
The dry ice was then removed and the outer surface was sprayed with isopropyl alcohol
to dissipate the moisture condensing on the outer surface allowing the inner space
of the window unit to be seen. If no condensation was visible, then the sample was
considered to have a frost point below -78 °C, the temperature of dry ice, solid CO
2.
Reference Example 2
[0097] In order to achieve the level of cure previously indicated within 3-4 weeks after
the application of the composition, the composition needs to contain a sufficient
amount of water that is liberated (available) at the given application temperature.
Availability of water at the application temperature is preferably determined on the
"wet" part of a two part composition rather than on the water release agent itself
or the mixed composition. Measurement of water availability on the water release agent
itself neglects any availability of water in the composition due to various other
factors, such as solubility of water in the polymeric ingredients of the composition.
Measurement of water availability in the mixed composition neglects to account for
reaction of water with silanes, silicon-reactive polymer and other water scavenging
ingredients, which may result in the conversion of water to reaction by-products,
such as alcohols.
[0098] Water availability at application temperature in the wet part of the 2-part composition
can be determined using a Karl-Fischer-Coulometer and an analytical scale with an
accuracy of 0.1 mg by a modification of the method described in Annex C of EN 1279
Glass in Building - Insulating Glass Units, Part 2, Long-Term Test Method and Requirements
for Moisture Penetration. Contrary to the standard test method, a temperature ramp-up
is applied. Details on the test procedure are described below:
Procedure Parameters: |
Start Temperature: |
50 °C |
End Temperature: |
250 °C |
Temperature Gradient: |
2 °C/min |
Gas Flow: |
50 ml/min |
Procedure:
[0099] A 0.5 g sample is taken from the bulk (not the surface) of the wet part of the composition
and immediately afterwards transferred into the vial of the Karl-Fischer-Coulometer.
The vial is transferred into an Oven Sample Processor of the Karl-Fischer-Coulometer,
and the measurement is started based on the procedural parameters set in the operating
software of the coulometer. Separate measurements are carried out on triplicate samples.
The Karl-Fischer method then determines the absolute amount of water that is liberated
from the wet part of the composition. Based on the weight of the sample, this absolute
amount can then be converted to weight % water released. Based on this reading, the
amount of water in the mixed, curable composition can be determined based on the mixing
ratio between the two components of the composition.
[0100] Good curability (as defined above) may be obtained when the amount of water released
at the application temperature is above 0.015 %, alternatively above 0.02 %, and alternatively
above 0.025 %, each based on the weight of the total, mixed composition.
Examples 1 to 3 - Comparison of Water Release Agents
[0101] Example 1 contains precipitated calcium carbonate as the only water release agent.
Example 2 contains both precipitated calcium carbonate and hydrated molecular sieves.
Example 3 contains no water release agent. Examples 1 to 3 were prepared as one-part
compositions by mixing the ingredients in Table 2 in the order listed using a Universal
Mixing Machine - Model AM 501 T from Hauschild, Waterkamp 1, Hamm 59075 Germany.
[0102] To prepare samples, first a pre-blend of was made by placing 25.2 grams of ingredient
(J2) wax with 18 grams of ingredient (E1) carbon black in a Hauschild mixing cup,
heating them at 97 °C for 30 minutes, and mixing for 26 seconds. The mixture was stirred
by hand and mixed again. The mixture was removed and pressed between two sheets of
release liner and cooled. This pre-blend was then added as a dry component in the
masterbatch.
Therefore, using 3.6 grams of pre-blend resulted in a 1.5 gram level of carbon black
in the composition.
[0103] Ingredients (A1) silylated copolymer, (F2) polyisobutylene, the pre-blend prepared
above, and (J2) wax were combined in a Hauschild mixing cup, heated at 97 °C in a
high airflow oven for one hour, and then mixed for 26 seconds. Ingredient (G2) vinyltrimethoxysilane
was then added to the cup and mixed with for another 26 seconds.
[0104] The following ingredients were then added in order: (D1) precipitated calcium carbonate,
(E2) ground calcium carbonate, (I1) tetraethylorthosilicate, (I2) gamma-aminopropyltriethoxysilane,
and (C1) molecular sieves. After each addition, the cup was placed in the high air
flow oven at 97 °C for 10 to 15 minutes and the contents of the cup were mixed for
26 seconds.
[0105] At this stage the material was considered the masterbatch for later work. To conserve
material and allow additional testing, a basis of 10 grams of masterbatch was used
and formulated to final compositions. In a smaller mixing cup, the masterbatch was
added and (D2) hydrated molecular sieves, if any, was mixed. This was followed by
adding (B2) tin catalyst and mixing. The time at which the mixer was started after
tin addition was considered the start of reactivity and was considered the start of
curing.
Table 2 - One part compositions.
Example # |
1 |
2 |
3 |
Ingredients |
Masterbatch, grams |
Masterbatch, grams |
Masterbatch, grams |
(A1) silylated copolymer |
15 |
15 |
15 |
(F2) polyisobutylene |
15 |
15 |
34 |
Pre-Blend |
3.6 |
3.6 |
3.6 |
(J2) wax |
7.9 |
7.9 |
7.9 |
heat components above and mix on Hauschild mixer for 26 seconds |
(G2) VTM |
0.2 |
0.2 |
0.2 |
mix on Hauschild mixer 26 seconds and same for every component after this |
(D1) precipitated CaCO3 |
20 |
20 |
|
(E2) ground CaCO3 |
19 |
19 |
19 |
(I1) TEOS |
0.3 |
0.3 |
0.3 |
(I2) A-1100 |
0.8 |
0.8 |
0.8 |
(C1) 3A sieves |
15 |
15 |
15 |
|
|
|
|
Masterbatch above |
9.68 |
9.68 |
9.68 |
(D2) Doucil 4A |
|
0.24 |
0.24 |
(B2) DBTDL |
0.07 |
0.07 |
0.07 |
[0106] The physical property of durometer and solvent resistance were measured as described
in reference example 1, and the results are in Table 3. Examples 1 and 2 show that
in this one-part composition, the presence of (D2) hydrated molecular sieves does
not significantly contribute to green strength, as shown by the initial durometer
results. Table 3 suggests that water from the hydrated molecular sieves (example 2)
does help this composition build 5 second durometer (bulk) and solvent resistance
slightly, although without the water from the precipitated calcium carbonate (example
3), cure would not be sufficiently fast for the fast processing cycle the IG industry
deems necessary. The cure via the Ares Rheometer also suggests internal cure water
allows this formulation to achieve sufficiently fast cure.
Table 3 - Results
Example # |
1 |
2 |
3 |
Days cured |
6 |
6 |
6 |
Durometer, Shore A, initial |
57 |
56 |
37 |
Durometer, Shore A, 5 second |
25 |
30 |
6 |
|
|
|
|
Days Cured |
6 |
6 |
6 |
Toluene solubility, liq. Clarity |
|
|
|
15 min |
|
|
10 |
1 hr |
0 |
0 |
10 |
2 hr |
0 |
0 |
10 |
4 hr |
0 |
0 |
10 |
overnight |
0 |
0 |
10 |
20 days |
1 |
0 |
10 |
|
|
|
|
Ares Rheometer |
|
|
|
initial cure @ 95 °C |
|
|
|
G' crosses G", min |
<4 |
<4 |
>130 |
G', dyn/cm^2 @ 95 °C |
74720 |
60520 |
-6000 |
[0107] Examples 1 and 2 further show formation of an elastomeric network can be achieved
at a rather low silylated copolymer content in this composition. This is surprising
because an insufficiently crosslinked network, resulting in poor elastomeric properties,
such as solvent resistance, swell/gel fraction, elastic recovery, did not occur.
Examples 4 to7-Ability to Cure
[0108] Examples 4 to 7 were used to demonstrate the ability to cure. Compositions were made
in a process similar to that described above for example 1 by mixing materials after
heating at 97 °C via a Hauschild mixer. As few components as possible were used for
differentiation of water source. Upon addition of the tin catalyst, the time for cure
was started. Table 4 below shows that the composition with no water added by some
means, example 4, did not cure in at least the one hour allowed for the testing. The
precipitated calcium carbonate sample, example 5, shows the fastest gel point at 4.5
minutes which was half of the high content hydrated molecular sieve formulation, example
7.
Table 4 - One Part Compositions
Example |
4 |
5 |
6 |
7 |
(A1) silylated copolymer |
20 |
20 |
20 |
20 |
(F1) polyisobutylene |
2 |
2 |
2 |
2 |
(D1) precipitated CaCO3 |
0 |
0 |
20 |
0 |
(D2) hydrated molecular sieves |
0 |
2.4 |
0 |
9.6 |
(B2) DBTDL |
0.7 |
0.7 |
0.7 |
0.7 |
Data on material |
|
|
|
|
% filler |
0 |
9.6 |
46.8 |
29.7 |
% water |
0 |
1.41 |
0.28 |
4.37 |
Ares Rheometer |
|
|
|
|
G' crosses G", min |
no cure |
11.7 |
4.5 |
8.5 |
G', dyn/cm^2 @ cross |
313 |
7185 |
i237300 |
13200 |
[0109] The water contents of the hydrated molecular sieves and precipitated calcium carbonate
were determined via a method of thermogravimetry using a Mark 4 Moisture Analyzer
set at 150 °C on the raw material and not the actual composition. This device measures
the weight loss and makes the assumption that the only substance coming off is water,
which in this case should be a valid assumption being on the raw material.
[0110] These experiments show that, at an application temperature of 100 °C, precipitated
CaCO
3 is a substantially more effective source of water than hydrated molecular sieves
in this composition. The storage modulus (G') is related to elastomeric properties
of the cured product of the composition. The loss modulus (G") is related to viscous
flow properties of the cured product. Achieving a cross-over of G' crosses G" moduli
within a short period of time can be interpreted as the composition starting to cure
more quickly. Example 5 shows that cure begins more quickly with precipitated CaCO
3 in this composition than with hydrated molecular sieves in examples 6 and 7, even
though the % of water in the composition is higher in examples 6 and 7 than in example
5. Example 5 had the highest G' value, corresponding to faster cure (more cure occurs
to form more cured network at this time in example 5 than in the comparative examples).
Without wishing to be bound by theory, it is thought that the composition of this
invention offers the advantage of having improved cure with reduced water content
as compared to compositions that contain larger amounts of water carried on hydrated
molecular sieves, and this may improve storage stability of the composition and may
reduce the risk of moisture diffusing into the interpane space of an IG unit. Based
on the results of examples 1-7, precipitated CaCO
3 may be used as water source for an application temperature range ranging from 90
°C to 110 °C, rather than molecular sieves. However, without wishing to be bound by
theory it is thought that saturated molecular sieve may be used for ingredient (D)
at a higher application temperature range,
e.
g., 120 °C to 140 °C. Furthermore, without wishing to be bound by theory it is thought
that the composition of this invention may offer the advantage of eliminating the
need for a hydrated salt as a water source, thereby avoiding the disadvantages associated
therewith, such as negative effect on adhesion.
[0111] To further investigate the cure by moisture content, examples 4 to 7 were tested
for solvent resistance according to reference example 1. Samples were tested after
7 and 6 days of cure. Although it was difficult see if a sample was dissolving since
no carbon black was present to effectively color the sample, in each case the samples
looked still intact although different. After in toluene for a day, the sample was
removed and the toluene was allowed to evaporate to determine what was left behind,
which is typical of the swell gel test. Weight measurements were not done so percent
gel or unreacted material was not available. However an indication of sample cure
can be seen from the thickness of the film left behind after the toluene evaporated.
In comparative example 2, very little material was left behind at 0.07 mm membrane
thicknesses suggesting very little cured network had formed and most likely cure had
just occurred from the surface exposed. Comparative examples 3 and 4 and example 3
all had enough moisture to cure the bulk of the material and be resistant to toluene
suggesting each to be a suitable moisture source given sufficient cure time. The results
are in Table 5.
Table 5 - Solvent Resistance
Example |
4 |
6 |
5 |
7 |
Toluene solubility, liq. Clarity |
time cured (days) |
7 |
7 |
6 |
6 |
15 min 1 flip |
0 |
0 |
0 |
0 |
2 hour |
0 |
0 |
0 |
0 |
4 hour |
0 |
0 |
0 |
0 |
Overnight |
0 |
0 |
0 |
0 |
thickness of dried film, mm |
0.07 |
2.6 |
2.3 |
2.9 |
Examples 8 to 10 - Ability to formulate product in a two-part system with mix ratio
of 1:1 by volume and 2:1 by weight
[0112] Examples 8-10 show that the composition may be prepared as a two-part composition
with a mix ratio of 1:1 or close to 1:1 (such as 1:2 or 2:1). Without wishing to be
bound by theory, it is thought that this is beneficial because these mix ratios are
more forgiving in terms of mix ratio tolerances than RTV two-part products, which
typically have mix ratios of 10:1 base to catalyst.
Example 8 (mixed), 9 (mixed), and 10 (mixed) gave good product when mixed in a
[0113] 1:1 by volume or 2:1 by weight mix ratio. In the 1:1 by volume examples no formulation
data is presented due to unknown data, but the individual parts can be done on a weight
basis and said to be mixed on a one to one by volume basis considering the specific
gravity of the two parts.
Table - 6 Two Part Compositions
Example |
8 (mixed) |
8 (mixed) |
9 (mixed) |
9 (mixed) |
10 (mixed) |
10 (mixed) |
Ingredients |
2:1 mix by weight |
1:1 mix by volume |
2:1 mix by weight |
1:1 mix by volume |
2:1 mix by weight |
1:1 mix by volume |
(A1) silylated copolymer |
25 |
|
20 |
|
15 |
|
(F3) polyisobutylene |
32.4 |
|
37.4 |
|
42.4 |
|
(J2) wax |
10 |
|
10 |
|
10 |
|
(E1) carbon black |
1.3 |
|
1.3 |
|
1.3 |
|
(G2) VTM |
0.067 |
|
0.067 |
|
0.067 |
|
(D1) precipitated CaCO3 |
14.67 |
|
14.67 |
|
14.67 |
|
(I2) adhesion promoter |
0.33 |
|
0.33 |
|
0.33 |
|
(C1) 3A molecular sieves |
15 |
|
15 |
|
15 |
|
(K1) Tinuvin 292 |
0.25 |
|
0.25 |
|
0.25 |
|
(K2) Tinuvin 571 |
0.25 |
|
0.25 |
|
0.25 |
|
(B1) tin, Metatin 740 |
|
|
|
|
|
|
(B2) tin, DBTDL |
0.7 |
|
0.7 |
|
0.7 |
|
|
|
|
|
|
|
|
Days cured |
4 |
7 |
4 |
7 |
4 |
7 |
Durometer, Shore A, initial |
32 |
48 |
38 |
46 |
32 |
45 |
Durometer, Shore A, 5 second |
4 |
21 |
7 |
15 |
5 |
13 |
Days cured |
6 |
56 |
6 |
56 |
6 |
56 |
Durometer, Shore A, initial |
32 |
55 |
42 |
56 |
32 |
53 |
Durometer, Shore A, 5 second |
4 |
24 |
8 |
22 |
5 |
18 |
|
|
|
|
|
|
|
Days Cured |
6 |
|
6 |
1 |
6 |
|
Toluene solubility, liq. Clarity |
|
|
|
|
|
|
15 min |
|
|
|
2 |
|
|
1 hr |
5 |
|
6 |
5 |
6 |
|
2 hr |
8 |
|
8 |
8 |
8 |
|
4 hr |
10 |
|
10 |
|
10 |
|
Overnight |
10 |
|
10 |
10 |
10 |
|
|
|
|
|
|
|
|
Days Cured |
41 |
56 |
40 |
56 |
40 |
56 |
Toluene solubility, liq. Clarity |
|
|
|
|
|
|
15 min |
0 |
0 |
0 |
0 |
0 |
0 |
1 hr |
|
0 |
|
0 |
|
0 |
2 hr |
0 |
|
0 |
|
0 |
|
4 hr |
0 |
|
0 |
|
0 |
|
Overnight |
0 |
|
0 |
|
0 |
|
[0114] Examples 8, 9, and 10 mixed on a 1 to 1 volume basis were also tested for flexibility.
The mandrel bend test, ASTM 3111 was done at -30°C. The mandrel and specimens of each
example were placed in a freezer at -30°C for 30 minutes. The size of each specimen
was 8 x 22 mm and 3 mm thick. Upon removal of samples and rod the samples were immediately
bent over the rod and inspected for any cracking or change. All samples were easily
bent and showed no signs of cracking.
Examples 11 and 12 - Commercially Available "Curable" and "Structural" PIB/Butyl Materials
[0115] Toluene solubility testing of example 11, Delchem D-2000 (advertised as a
reactive Hot Melt Butyl IG Sealant example 12, Delchem D30 HM Butyl (advertised as a Hot Melt
Butyl IG Sealant with
improved structural properties for the Intercept® spacer system), both commercially available from Delchem, Inc.,
P.O. Box 10703 , Wilmington, DE 19850, U.S.A, and example 13 Ködimelt TPS a (non-curable)
TPS material from Kommerling, Pirmasens, Germany, show these materials do not crosslink
well even after being dispensed and allowed to cure for 3 years. The toluene solubility
data for the Delchem D-2000 based on the numbers reported in Table 7 appears to be
low, even when stored overnight, however the material was falling apart and breaking
up. In previous swell gel testing much of the Delchem D-2000 was dissolved and the
HM Butyl dissolved completely, which is representative of a non-crosslinked system.
Similarly as Kommerling Ködimelt is non-curable, the material dissolves in toluene
even after 3 years storage.
Table - 7 Commercially Available TPS Materials
Example |
11 |
12 |
13 |
|
Delchem D-2000 |
Delchem D-130 HM Butyl. |
Kommerling Ködimelt |
Days Cured |
3 years |
3 years |
|
Toluene solubility, liq. Clarity |
|
|
|
15 min |
0 |
1 |
|
1 hr |
0 |
2 |
|
2 hr |
0.5 |
3 |
|
4 hr |
0.5 |
3 |
|
Overnight |
2* |
8 |
10 |
*color difference was not evidenced and absence of discoloration of solvent was believed
to be due to lack of carbon black filler in the formulation. |
Examples 14 to 17 - Development of Green Strength
[0116] Rapid development of green strength is desirable because it may allow handling of
sealed IG units at the end of a production line and early shipping of the units (units
can be made to order and shipped rapidly). Without wishing to be bound by theory,
it is thought that microcrystalline wax provides excellent green strength to the sealant,
i.
e.
, a strong increase in composition viscosity with a temperature drop.
[0117] Example 15 is meant to demonstrate the development of green strength, or strength
before cure, of a material without the effects of onset of cure confounding green
strength. Example 15, therefore, is an otherwise curable formulation however without
addition of a tin catalyst so as to delay the onset of cure. The lap shear strength
was measured according to ASTM D816-82(1993)e1, D1002-94 using glass panels and applying
heated material in a heated area. The sample produced a lap shear value of 20.4 psi.
Example 16 was made without tin catalyst and gave a lap shear value of 22.7 psi. Example
14 was the same as example 16 except tin catalyst was added. Example 14 produced a
lap shear value of 36.7 psi after 7 days of cure. In comparison, example 17 of Ködimelt
TPS from Kömmerling gave a lap shear value of 13.7 psi. Therefore, the green strength
from composition of example 13 is sufficient for manufacture of IG units. These values
were all measured at room temperature.
Table 8
Example |
15 |
14 |
16 |
17 |
Formulation components |
parts |
parts |
parts |
TPS from Kömmerling |
(A1) silylated copolymer |
10 |
15 |
15 |
|
(F1) polyisobutylene |
10 |
|
|
|
(F2) polyisobutylene |
10 |
15 |
15 |
|
(J1) wax |
10 |
|
|
|
(J2) wax |
|
10 |
10 |
|
(E1) carbon black |
2 |
2.0 |
2.0 |
|
(G1) VTES |
0.2 |
|
|
|
(G2) VTM |
|
0.2 |
0.2 |
|
(D1) precipitated CaCO3 |
20 |
2C |
20 |
|
(E2) ground CaCO3 |
19 |
19 |
19 |
|
(I1) TEOS |
0 |
0.3 |
0.3 |
|
(I2) aminopropyltriethoxysilane |
1 |
0.8 |
0.8 |
|
(C1) 3A sieves (dry) |
|
15 |
15 |
|
(C2) 4A dried sieves (dry) |
15 |
|
|
|
(D3) 4A sieves (wet) |
1.5 |
|
|
|
D2) 4A sieves (wet) |
|
2.4 |
|
|
(B2) tin catalyst, DBTDL |
|
0.7 |
|
|
Lap Shear |
|
|
|
|
days cured |
no cure*) |
7 |
no cure*) |
no cure*) |
peak stress, psi |
20.4 |
36.7 |
22.7 |
13.7 |
% strain at peak |
2.67 |
2.8 |
2.1 |
12.2 |
failure form |
100% cohesive |
10% cohesive-voids |
N/A |
N/A |
*) Tested immediately after cool-down to ambient laboratory temperature (ca. 23°C) |
Example 18 - Cold Flexibility Despite Presence of Wax
[0118] Example 18 Parts A and B mixed by volume on a 1 to 1 basis showed a lap shear value
of 78.4 psi and a strain of 4.6% even at -31°C after 7 days of cure. The sample was
made up in the individual parts similar to the method for Examples 8-10 previously
explained again using a masterbatch of carbon black, but in the case here, the antioxidants
were also added to this blend. The lap shear specimen was prepare by normal means
according to ASTM D816-82(1993)e1, D1002-94 on 2 pieces of glass 1 inch by 3 inches
where the bondline of adhesive was 0.25 inches thick. The material was mixed and applied
to the glass through a two part 50 cc mixing system that used a seventeen element
static mixer while being heated in a 94°C oven.
Table 9 - Two Part Composition
Example |
18A |
18B |
Ingredients |
parts |
parts |
(A1) silylated polyisobutylene |
42.8 |
|
(F3) polyisobutylene |
|
19.6 |
(J2) wax |
10 |
10 |
(E1) carbon black |
1 |
|
(D1) precipitated CaCO3 |
22 |
18 |
(E2) ground CaCO3 |
19 |
19 |
(I4) adhesion promoter |
|
1 |
(G3) phenyltrimethoxysilane |
|
1 |
(C1) molecular sieves |
|
30 |
(D2) hydrated molecular sieves |
4.8 |
|
(K1) Tinuvin 292 |
0.2 |
|
(K2) Tinuvin 571 |
0.2 |
|
(B2) tin catalyst, DBTDL |
|
1.4 |
Example 19 - Two-Part Formulation Prepared on Continuous Compounder
[0119] The two-part composition shown in Table 10 was compounded on a COPERION 25 mm co-rotating,
fully intermeshing twin screw extruder, 12 barrels long (48:1 Length:Diameter, L:D
ratio).
Table 10 - Two-Part Composition
Example |
19A |
19B |
Ingredients |
parts |
parts |
(A1) silylated polyisobutylene |
|
38.0 |
(F4) polyisobutylene |
38.0 |
|
(J2) wax |
1.0 |
1.0 |
(L1) tackifier |
9.0 |
2.0 |
(E1) carbon black |
30.0 |
|
(D1) precipitated CaCO3 |
22.0 |
|
(I4) adhesion promoter |
|
1.0 |
(G2) Vinyltrimethoxysilane |
|
0.2 |
(G3) phenyltrimethoxysilane |
|
1.0 |
(C1) molecular sieves |
|
54.0 |
(K1) Tinuvin 292 |
|
0.4 |
(K2) Tinuvin 571 |
|
0.4 |
(B2) tin catalyst, DBTDL |
|
2.0 |
An intermediate of Part A was prepared by feeding ingredient (F4) in the first barrel
of the extruder via a Bonnot pump and gear pump for metering. Ingredients (J2) and
(L1) were added in the third barrel. A pre-blend of ingredient (D1) and ingredient
(E1) was prepared by shaking these ingredients in a plastic bag, and 60% of this filler
pre-blend (by weight) was added in the ninth barrel of the extruder. Vacuum was pulled
in the eleventh barrel. The resulting mixture was extruded at the end of the twelfth
barrel as an intermediate.
After completion of the intermediate manufacture, this intermediate was again fed
into the first barrel via a Bonnot pump and gear pump for metering. The remaining
40% of the filler pre-blend was added in the ninth barrel of the extruder. Vacuum
was pulled in the eleventh barrel. The resulting mixture was extruded at the end of
the twelfth barrel as Part A of the composition.
[0120] Part B was prepared by feeding ingredient (A1) via a Bonnot pump and gear pump for
metering in barrel 1. Ingredients (J2) and (L1) were added in barrel 3. Ingredients
(I4), (G2), (G3), (K1), (K2), and (B2) were pre-blended in glassware by shaking manually
and then added in barrel 5 via high pressure high pressure dual piston (HPLC) pump.
Vacuum was pulled at barrel 7 to strip off methanol. Ingredient (C1) was added in
barrel 9. Vacuum was pulled in barrel 11. The resulting mixture was extruded at the
end of barrel 12.
[0121] The extruder ran at 200 to 600 rpm for Part A and 100 to 400 rpm for Part B (machine
capability is 0 - 1200 rpm). When making Part A, the temperature profile ranged from
90 °C to 120 °C along the length of the machine (half the length was at 90 °C and
the rest was at 120 °C). When making part B, the temperature profile was typically
90 °C for the whole length of the machine.
[0122] Parts A and B were packaged into 500 mL 'sausage' containers. Parts A and B were
mixed together by a two-part mixing and dosing machine. The sausage containers were
fed into two cylinders pressurized to ca. 280 10
5 Pa by hydraulics for feeding the two parts into a heated static mixer (length 80
cm, minimum 15 static mixing elements) and from there into a gear pump and then into
a Bystronic TPS application head (with a 5.8 mm x 18 mm extrusion die). The equipment
was set to 90 °C application temperature. Further experimental conditions for the
application equipment are in Table 11.
Table 11 - Experimental Conditions Application Trial
Application Equipment Process Parameters |
Units |
Temperature |
90 |
°C |
Hydraulics pressure |
285 |
105 Pa |
Material pressure prior to static mixer |
125 |
105 Pa |
Material pressure post static mixer |
30 |
105 Pa |
|
|
|
Die (nozzle) |
5.8 |
Mm |
Extrusion width |
18.2 |
Mm |
Conveyor speed (estimate) |
0.2 |
m/min |
Extrusion rate |
0.02184 |
l/min |
Appearance of extrusion bead |
Good |
|
Wet-out |
Good |
|
Slump of bead |
Slight slump (ca. 9°) |
Measured after 1 hour |
[0123] Excellent mixing of the two parts was achieved (judged visually by cutting about
1/3 through the bulk mixed material and then extending the cut by pulling the strands
apart) with >15 static mixing elements. At 90 °C, the composition prepared by mixing
the two parts extruded well (except for the low extrusion rate (ca. 100 g/min) achieved
on the application equipment). The composition had good wet-out on glass (judged by
visually inspecting the glass/sealant interface through the glass) and good tack on
glass when applied hot at 90 °C.
When applied at lower temperatures (30 °C to 40 °C) to a cold glass surface, the composition
still exhibited acceptable tack. The composition also had good self-adhesion (newly
applied hot material adhering to previously applied cold material).
[0124] A 2 mm thick sheet of the composition was cured at 90 °C and 30 10
5 Pa pressure for 40 minutes. Afterwards the resulting cured product showed a near
100% elastic recovery when bent by 90° around a mandrel within 1 minute. The cured
product did not dissolve when stored in toluene at room temperature for 1 week with
daily repetitive vigorous shaking.
Example 19 - Two-Part Formulation Prepared on Continuous Compounder
[0125] The two-part composition shown in Table 12 is compounded on a COPERION 25 mm co-rotating,
fully intermeshing twin screw extruder, 12 barrels long (48:1 Length:Diameter, L:D
ratio).
Table 12 - Two-Part Composition
Example |
19A |
19B |
Ingredients |
parts |
parts |
(A1) silylated polyisobutylene |
|
38.0 |
(F4) polyisobutylene |
38.0 |
|
(J2) wax |
1.0 |
1.0 |
(L1) tackifier |
9.0 |
2.0 |
(E1) carbon black |
30.0 |
|
(D1) precipitated CaCO3 |
22.0 |
|
(I4) adhesion promoter |
|
1.0 |
(G2) Vinyltrimethoxysilane |
|
0.2 |
(G3) phenyltrimethoxysilane |
|
1.0 |
(C1) molecular sieves |
|
54.0 |
(K1) Tinuvin 292 |
|
0.4 |
(K2) Tinuvin 571 |
|
0.4 |
(B2) tin catalyst, DBTDL |
|
2.0 |
[0126] Part A is prepared by feeding ingredient (F4) in the first barrel of the extruder
via a Bonnot pump and gear pump for metering. Ingredients (J2) and (L1) are added
in the third barrel. A pre-blend of 22 parts ingredient (D1) and 15 parts ingredient
(E1) is prepared by shaking these ingredients in a plastic bag. The pre-blend is added
in the ninth barrel of the extruder. The remaining 15 parts of ingredient (E1) str
added in the sixth barrel. Vacuum s pulled in the eleventh barrel. The resulting mixture
is extruded at the end of the twelfth barrel.
[0127] Part B is prepared by feeding ingredient (A1) via a Bonnot pump and gear pump for
metering in barrel 1. Ingredients (J2) and (L1) are added in barrel 3. Ingredients
(I4), (G2), (G3), (K1), (K2), and (B2) are pre-blended in glassware by shaking manually
and then added in barrel 5 via high pressure HPLC pump. Vacuum is pulled at barrel
7 to strip off methanol.
Ingredient (C1) is added in barrel 9. Vacuum is pulled in barrel 11. The resulting
mixture is extruded at the end of barrel 12.
[0128] The extruder is run at 200 to 600 rpm for Part A and 100 to 400 rpm for Part B (machine
capability is 0 - 1200 rpm). When making Part A, the temperature profile ranges from
90 °C to 120 °C along the length of the machine (half the length is at 90 °C and the
rest is at 120 °C). When making part B, the temperature profile is typically 90 °C
for the whole length of the machine.
[0129] Parts A and B are packaged into 500 mL 'sausage' containers. Parts A and B are mixed
together by a two-part mixing and dosing machine. The sausage containers are fed into
two cylinders pressurized to ca. 280 10
5 Pa by hydraulics for feeding the two parts into a heated static mixer (length 80
cm, minimum 15 static mixing elements) and from there into a a gear pump and then
into a Bystronic TPS application head (with a 5.8 mm x 18 mm extrusion die). The equipment
is set to 90 °C application temperature. Further experimental conditions for the application
equipment are in Table 13.
Table 13 - Experimental Conditions Application Trial
Application Equipment Process Parameters |
Units |
Temperature |
90 |
°C |
Hydraulics pressure |
285 |
105 Pa |
Material pressure prior to static mixer |
125 |
105 Pa |
Material pressure post static mixer |
30 |
105 Pa |
|
|
|
Die (nozzle) |
5.8 |
Mm |
Extrusion width |
18.2 |
Mm |
Conveyor speed (estimate) |
0.2 |
m/min |
Extrusion rate |
0.02184 |
l/min |
Appearance of extrusion bead |
Good |
|
Wet-out |
Good |
|
Slump of bead |
Slight slump (ca. 9°) |
Measured after 1 hour |
Example 20 - Two-Part Formulation Prepared on Continuous Compounder
[0130] The two-part composition shown in Table 14 was compounded on a COPERION 25 mm co-rotating,
fully intermeshing twin screw extruder, 12 barrels long (48:1 Length:Diameter, L:D
ratio).
Table 14 - Two-Part Composition
Example |
20A |
20B |
Ingredients |
parts |
parts |
(A1) silylated polyisobutylene |
|
47.8 |
(F3) polyisobutylene |
42.35 |
|
(J2) wax |
1.0 |
1.0 |
(F5) polyolefin plastomer |
5.0 |
7.5 |
(F6) SEPS block copolymer |
|
12.5 |
(E3) untreated fumed silica |
10.0 |
10.0 |
(E1) carbon black |
0.05 |
|
(D1) precipitated CaCO3 |
|
20 |
(I4) aminoethylaminopropyltrimethoxysilane adhesion promoter r |
0.8 |
|
(G3) phenyltrimethoxysilane |
|
0.4 |
(C3) molecular sieve (zeolite) 3A (dry) |
40 |
|
(K1) Tinuvin 292 |
|
0.4 |
(K2) Tinuvin 571 |
|
0.4 |
(B2) DBTDL tin catalyst |
0.8 |
|
[0131] Part A was prepared by pre-blending ingredients (J2) and (F5) and metering them into
the first barrel with a gravimetric single screw feeder (K-Tron). The materials are
mixed and masticated in the first two barrels prior to pumping and metering 30-50%
of ingredient (F3) into the third barrel using a Bonnot pump in conjunction with a
gear pump. These materials are thoroughly mixed prior to the injection of ingredients
(I4) and (B2) in the fourth barrel using HPLC pumps, a static mixer, and a high pressure
injection valve. Again, these materials are thoroughly mixed prior to adding ingredients
(C3) and (E1) which are pre-blended and fed into the side of barrel 6 using a twin
screw feeder (Brabender) along with a twin screw side stuffer (Coperion). The materials
are incorporated into the blend and the balance of the remaining 50-70% of ingredient
(F3) is added in barrel 7 using a Bonnot pump in conjunction with a gear pump. The
fillers are well dispersed prior to adding ingredient (F6) in the side of barrel 9
again using a twin screw feeder (K-Tron) in conjunction with a twin screw side stuffer
(Coperion). The second filler is well dispersed and vacuum is applied on barrel 11
to remove residual by-products and air. The resulting mixture is extruded at the end
of the twelfth barrel.
[0132] Part B was prepared by pre-blending ingredients (J2), (F5), and (F6) and metering
them into the first barrel with a gravimetric single screw feeder (K-Tron). The materials
are mixed and masticated in the first two barrels prior to pumping and metering 30-50%
of ingredient (A1) into the third barrel using a Bonnot pump in conjunction with a
gear pump. These materials are thoroughly mixed prior to the injection of ingredients
(G3), (K1), and (K2) in the fourth barrel using HPLC pumps, a static mixer, and a
high pressure injection valve. Again, these materials are thoroughly mixed prior to
adding ingredient (D1) which was fed into the side of barrel 6 using a twin screw
feeder (Brabender) along with a twin screw side stuffer (Coperion). The materials
are incorporated into the blend and the balance of the remaining 50-70% of ingredient
(A1) is added in barrel 7 using a Bonnot pump in conjunction with a gear pump. The
fillers are well dispersed prior to adding ingredient (E3) in the side of barrel 9
again using a twin screw feeder (K-Tron) in conjunction with a twin screw side stuffer
(Coperion). The second filler is well dispersed and vacuum is applied on barrel 11
to remove residual by-products and air. The resulting mixture is extruded at the end
of the twelfth barrel.
[0133] The extruder ran at 200 to 600 rpm for Part A and 100 to 400 rpm for Part B (machine
capability is 0 - 1200 rpm). When making part A, the temperature profile was typically
90 °C for the whole length of the machine. When making Part B, the temperature profile
ranged from 120 °C to 90 °C along the length of the machine (first three barrels were
at 120 °C and the rest of the machine was at 90 °C).
[0134] Parts A and B were packaged into 200 L drums using a lance type filling system. Parts
A and B were mixed together by a two-part mixing and dosing machine. Materials (Part
A and B) from the drums were fed into the pressure cylinders (described in Examples
18 and 19) via hydrolytically operated hot melt drum pumps using heated follower-plate.
The two cylinders were then pressurized to ca. 280 10
5 Pa by hydraulics for feeding the two parts into a heated static mixer (length 80
cm, minimum 15 static mixing elements) and from there into a gear pump and then into
a Bystronic TPS application head (with a 5.8 mm x 18 mm extrusion die). The equipment
was set to 95 °C application temperature. Further experimental conditions for the
application equipment are in Tables 15 and 16.
Table 15 - Experimental Conditions Application Trial
Application Equipment Process Parameters |
Units |
Temperature |
95 |
°C |
Material pressure prior to static mixer |
Variable |
105 Pa |
Material pressure post static mixer |
Variable |
105 Pa |
|
|
|
Die (nozzle) |
5.8 |
Mm |
Extrusion width |
18.2 |
Mm |
Extrusion rate |
Variable |
l/min |
Appearance of extrusion bead |
Good |
|
Wet-out |
Good |
|
Slump of bead |
Slight slump (ca. 9°) |
Measured after 1 hour |
Table 16 - Experimental Conditions Application Trial
Gear pump speed rpm (l/min) |
Torque gear pump (Nm) |
pressure before gear pump (105 Pa) |
pressure after gear pump (105 Pa) |
Extrusion rate (grams / minute) |
10 |
5,1 |
-43 |
∼47 |
294 |
20 |
6,9 |
37-39 |
78-65 |
574,8 |
30 |
7,8 |
36-34 |
92-75 |
838,5 |
40 |
8,7 |
34-32 |
107-82 |
1122 |
50 |
9,2 |
29-28 |
119-90 |
1402,4 |
60 |
9,2 |
29-27 |
128-92 |
1636 |
[0135] Excellent mixing of the two parts was achieved (judged visually by cutting about
1/3 through the bulk mixed material and then extending the cut by pulling the strands
apart) with >15 static mixing elements. At 95 °C, the composition prepared by mixing
the two parts extruded well (at a gear pump rotation speed of 60 rpm, a maximum extrusion
rate of about 1600 grams/minute was achieved. The composition had good wet-out on
glass (judged by visually inspecting the glass/sealant interface through the glass)
and good tack on glass when applied hot at 95 °C. When applied at lower temperatures
(30 °C to 40 °C) to a cold glass surface, the composition still exhibited very good
tack. The composition also had good self-adhesion (newly applied hot material adhering
to previously applied cold material). Up to an extrusion width of 12 mm, the bead
exhibited no slump at all.
[0136] A 2 mm thick sheet of the composition was cured at 100 °C and 30 10
5 Pa pressure for 40 minutes. Afterwards the resulting cured product showed a near
100% elastic recovery when bent by 90° around a mandrel within 1 minute. The cured
product did not dissolve when stored in toluene at room temperature for 1 week with
daily repetitive vigorous shaking.
[0137] A first insulating glass (IG) unit was prepared in order to evaluate the load bearing
capability of the freshly applied bead. The IG unit was assembled as follows: First
a 12 mm wide and 5.8 mm thick bead of the mixed material was applied along the perimeter
of a 4 mm thick float glass pane with 50 x 50 cm
2 dimensions. Immediately afterwards, the glass pane together with the applied bead
was pressed against a 4 mm thick float glass pane with 100 x 100 cm
2 dimensions in such a manner that the smaller pane was centered exactly in the middle
of the larger pane. The smaller pane was then set on wooden setting blocks in such
a way that the larger pane was complete unsupported and the bead of the mixed material
had to carry the weight of the unsupported pane. After 1 hour, a maximum sagging of
2.5 mm of the larger pane was observed. In comparison, a freshly applied TPS/silicone
dual seal tested under the same conditions will results in a maximum sagging of 3-4
mm of the unsupported glass pane.
[0138] A second insulating glass (IG) unit was prepared in order to evaluate the initial
adhesion (tack) of the freshly applied bead. The IG unit was assembled as follows:
First a 12 mm wide and 5.8 mm thick bead of the mixed material was applied along the
perimeter of a 4 mm thick float glass pane with 35 x 55 cm
2 dimensions. Immediately afterwards, the glass pane together with the applied bead
was pressed against a 4 mm thick float glass pane with 35 x 55 cm
2 dimensions. After allowing the material to cool down for 1 hour, the initial adhesion
(tack) of the material was tested by performing the butterfly test on the IG unit
as described in European Standard EN 1279 Part 6 (2002) in Annex F.4.2 Butterfly Test.
The butterfly test was performed by rotating the two cut pieces of float glass by
180° without any loss of adhesion of the sealant material being observed.
[0139] The stability of the material components (Parts A and B) was tested by keeping the
drums heated at 95°C for 16 hours. Afterwards the extrusion rate was tested as described
before in this Example. No changes in extrusion rate were observed.