Fluorosilicone rubber composition
First Claim
1. A curable fluorine-substituted organopolysiloxane composition which comprises, in mixture(A) a polyorganosiloxane having a viscosity of at least 400 centipoise at 25°
- C. and a molecular structure represented by the general formula
space="preserve" listing-type="equation">.sup.1 --O--(--SiR.sub.2 --O--).sub.n --(--SiRR.sub.f --O--).sub.m --X.sup.2,or
space="preserve" listing-type="equation">[X.sup.1 --O--(--SiR.sub.2 i--O--).sub.n --(--SiRR.sub.f --O--).sub.m --].sub.p SiR.sub.4-p,in which R is a monovalent hydrocarbon group selected from the class consisting of methyl, vinyl and phenyl groups, Rf is a fluorinated alkyl group having 3 to 10 carbon atoms, n is zero or a positive integer, m is a positive integer with the proviso that n;
(m+n) is in the range from 0.005 to 1, p is 2, 3 or 4, X1 is a vinyl dimethyl siloxy-substituted silyl group represented by the general formula
space="preserve" listing-type="equation">Vi-SiMe.sub.2 --(--O--SiMe.sub.2 --).sub.r --,in which Vi is a vinyl group, Me is a methyl group and r is a positive integer in the range from 1 to 30, and X2 is a hydrogen atom or X1 ; and
(B) an organic peroxide curing agent in an amount sufficient to cure the component (A).
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Accused Products
Abstract
The fluorine-substituted organopolysiloxane as the principal ingredient of the inventive silicone rubber composition has vinyl groups to serve as the cross-linking points at the molecular chain terminals while at least the penultimate siloxane unit or the silicon atom adjacent to the terminal silicon atom has no fluorine-substituted hydrocarbon group bonded to the silicon atom. Being freed from the steric hindrance due to the bulky fluorine-substituted hydrocarbon group bonded to the adjacent silicon atom, the vinyl group bonded to the terminal silicon atom can pertain to the cross-linking reaction much easier than otherwise so that the silicone rubber composition of the invention containing an organic peroxide or a combination of an organohydrogenpolysiloxane and a platinum catalyst as a curing agent can be rapidly cured to give a cured silicone rubber article having excellent resistance against oils and organic solvents as well as mechanical properties.
297 Citations
8 Claims
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1. A curable fluorine-substituted organopolysiloxane composition which comprises, in mixture
(A) a polyorganosiloxane having a viscosity of at least 400 centipoise at 25° - C. and a molecular structure represented by the general formula
space="preserve" listing-type="equation">.sup.1 --O--(--SiR.sub.2 --O--).sub.n --(--SiRR.sub.f --O--).sub.m --X.sup.2,or
space="preserve" listing-type="equation">[X.sup.1 --O--(--SiR.sub.2 i--O--).sub.n --(--SiRR.sub.f --O--).sub.m --].sub.p SiR.sub.4-p,in which R is a monovalent hydrocarbon group selected from the class consisting of methyl, vinyl and phenyl groups, Rf is a fluorinated alkyl group having 3 to 10 carbon atoms, n is zero or a positive integer, m is a positive integer with the proviso that n;
(m+n) is in the range from 0.005 to 1, p is 2, 3 or 4, X1 is a vinyl dimethyl siloxy-substituted silyl group represented by the general formula
space="preserve" listing-type="equation">Vi-SiMe.sub.2 --(--O--SiMe.sub.2 --).sub.r --,in which Vi is a vinyl group, Me is a methyl group and r is a positive integer in the range from 1 to 30, and X2 is a hydrogen atom or X1 ; and (B) an organic peroxide curing agent in an amount sufficient to cure the component (A). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- C. and a molecular structure represented by the general formula
Specification