Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
1999-08-27
2001-01-30
Moore, Margaret G. (Department: 1712)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S838000, C528S034000, C008SDIG001, C008S115580, C008S115640
Reexamination Certificate
active
06180712
ABSTRACT:
FIELD OF THE INVENTION
The invention generally relates to silicone water-based emulsion compositions. More particularly, the invention relates to a silicone water-based emulsion composition that can be converted to silicone elastomer by the removal of water with the concomitant formation of a rubber coating that is highly adherent to substrates.
BACKGROUND OF THE INVENTION
Within the art of silicone water-based emulsion compositions that form rubber coatings upon water removal, Japanese Laid Open (Kokai or Unexamined) Patent Application Number Sho 56-16553 (16,553/1981), for example, teaches a silicone emulsion composition comprising hydroxyl-functional diorganosiloxane, colloidal silica, and an organotin compound or an organoamine compound. One problem with this composition is its inadequate adherence to fabrics and textiles. Although there have been attempts to address this problem through the addition of an amino-functional organoalkoxysilane or epoxy-functional organoalkoxysilane as an adhesion promoter (refer to Japanese Laid Open (Kokai or Unexamined) Patent Application Number Hei 5-98579 (98,579/1993)), this approach can still suffer from an inadequate adherence and may cause post-treatment yellowing of fabrics and textiles.
SUMMARY OF THE INVENTION
It has now been discovered that the problems discussed above can be solved by the inclusion of a silatrane derivative in the water-based silicone composition.
The invention thus relates to a silicone water-based emulsion composition whose main components are
(A) an organopolysiloxane that contains at least 2 silicon-bonded hydroxyl or alkoxy groups in each molecule,
(B) a microparticulate silica,
(C) a curing catalyst, and
(D) a silatrane derivative having the formula
wherein each R
1
is independently selected from hydrogen or C
1
to C
10
alkyl groups, each R
2
is independently selected from hydrogen, C
1
to C
10
alkyl, or an alkoxysilyl-functional organic group with the formula —R
4
Si(OR
5
)
x
R
6
(3-x)
in which R
4
is a divalent organic group, R
5
is C
1
to C
10
alkyl, R
6
is a monovalent organic group, and x is 1, 2, or 3 with the proviso that at least 1 of the R
2
groups is the above-defined alkoxysilyl-functional organic group, and R
3
is selected from substituted or unsubstituted monovalent hydrocarbon groups, C
1
to C
10
alkoxy, glycidoxyalkyl, oxiranylalkyl, acyloxyalkyl, or aminoalkyl.
The invention further relates to a method of treating one or more fibers by coating at least a portion of said fibers with the above described water-based emulsion composition.
DETAILED DESCRIPTION OF THE INVENTION
The organopolysiloxane constituting component (A) is a straight-chain or branched organopolysiloxane that contains at least 2 silicon-bonded hydroxyl or alkoxy groups in each molecule. Diorganopolysiloxane with the following general formula is a typical example of the organopolysiloxane (A) under consideration.
The groups R in this general formula are each independently selected from monovalent organic groups. These monovalent organic groups can be specifically exemplified by saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, and dodecyl; unsaturated aliphatic hydrocarbon groups such as vinyl, allyl, and hexenyl; saturated alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl; aromatic hydrocarbon groups such as phenyl, tolyl, and naphthyl; halogen-substituted hydrocarbon groups such as 3,3,3-trifluoropropyl, 3-chloropropyl and nonafluorobutylethyl; epoxy-functional organic groups such as 3-glycidoxypropyl and 3,4-epoxycyclohexyl; carboxyl or carboxyl derived organic groups such as —(CH
2
)
10
COOH, —(CH
2
)
2
COOCH
3
, —(CH
2
)
10
COOSi(CH
3
)
3
and —CH
2
CH(CH
3
)COOCH
3
; amino-functional organic groups such as —C
3
H
6
NHC
2
H
4
NH
2
, —C
3
H
6
NHC
6
H
11
and —C
3
H
6
NH
2
; and methacryl-functional organic groups such as methacryloxymethyl and 3-methacryloxypropyl. The group X is hydroxyl or alkoxy group, wherein the alkoxy can be exemplified by methoxy, ethoxy, and propoxy. The group Y is hydrogen or an alkyl group, wherein the alkyl can be exemplified by methyl, ethyl, and propyl. The group Z is —(OSiR
2
)
k
X. The subscripts n and k are both integers ≧0, while the subscript m is an integer ≧1. The total number average molecular weight of component (A) should be at least about 20,000, preferably 20,000 to 300,000, and the preferred ranges for the subscripts are as follows: n=integer from 0 to 100, k=integer from 0 to 100, and m=integer from 300 to 4,000. Component (A) is preferably used in emulsion form.
Organopolysiloxane (A) can be exemplified by polymers with the following structures.
Organopolysiloxane (A) can be synthesized by known methods. For example, component (A) can be synthesized by the re-equilibration reaction of &agr;,&ohgr;-dihydroxysiloxane oligomer or organoalkoxysilane with cyclic siloxane, e.g., octamethylcyclotetrasiloxane, in the presence of a catalyst such as alkali metal hydroxide. Component (A) can also be synthesized by known emulsion polymerization techniques, for example, by first emulsifying reactants such as cyclic siloxane and organoalkoxysilane in water using anionic or cationic surfactant and then running a polymerization reaction with the addition of an acid or base catalyst, as necessary. The organoalkoxysilane used for this emulsion polymerization will have the general formula R
q
Si(OR
5
)
4-q
in which R and R
5
are defined as above and q is 1 or 2. This organoalkoxysilane can be exemplified by dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, &ggr;-aminopropyltrimethoxysilane, &ggr;-aminopropyltriethoxysilane, N-(&bgr;-aminoethyl)-&ggr;-amiiiopropyltrimethoxysilane, and &ggr;-glycidoxypropyltrimethoxysilane.
The microparticulate silica (B) functions to improve the post-cure strength of the rubber coating. Colloidal silica is highly suitable for use as component (B). This component can be used in the form of the emulsion afforded by emulsification in water using surfactant, but may also be used by first mixing it into the organopolysiloxane (A) and then dispersing the resulting mixture in water using surfactant. While the quantity of component (B) addition is not critical, component (B) is preferably added at from 0.5 to 100 weight parts per 100 weight parts (A) and more preferably at from 1 to 50 weight parts per 100 weight parts (A).
The curing catalyst (C) functions to induce crosslinking of the composition according to the present invention. This component can be specifically exemplified by the metal salts of organic acids, such as dibutyltin dilaurate, dibutyltin dioctate, dioctyltin dilaurate, dioctyltin diacetate, tin octanoate, zinc stearate, zinc octanoate, and iron octanoate; and by amine compounds such as n-hexylamine and guanidine. Except in those cases in which this component is water soluble, this curing catalyst is advantageously employed in the form of the emulsion prepared in advance by emulsification in water with the aid of surfactant. While the quantity of component (C) addition is not critical, this component is preferably added at from 0.01 to 10 weight parts per 100 weight parts (A) and more preferably at from 0.1 to 5 weight parts per 100 weight parts (A).
Component (D), which functions to improve the adherence and intimacy of contact exhibited by the composition according to the present invention, is a silatrane derivative with the following formula.
Each R
1
in this formula is independently selected from hydrogen or C
1
to C
10
alkyl. The alkyl encompassed by R
1
can be exemplified by methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, cyclopentyl, and cyclohexyl. R
1
is preferably hydrogen or methyl. Each R
2
in the preceding general formula is independently selected from hydrogen, C
1
to C
10
alkyl, or alkoxysilyl-functional organic groups with the formula —R
4
Si(OR
5
)
x
R
6
(3-x)
in which R
4
is a divalent organic grou
Ishikawa Hiroki
Naganawa Tsutomu
Ona Isao
Yoshitake Makoto
Dow Corning Silicone Co., Ltd.
Moore Margaret G.
Weitz Alex
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