Abstract Coating compositions containing specified quantities of (a) an Alpha , omega -dihydroxydimethylpolysiloxane polymer, with a viscosity of at least 25,000 cPo at 25*C, containing at most 0.1 percent by weight of hydroxyl groups, (b) a dimethylpolysiloxane rubber terminated at each end of its chain by a unit of the formula (CH3)3SiO0.5 or (CH3)2CH2 CHSiO0.5, with a viscosity of at least 1 million cPo at 25*C, (c) a crosslinking agent of the general formula (Q)4 nSi((OCH2CH2)pOQ'')n in which the symbol Q represents a hydrolysable radical selected from the group consisting of N,N-dialkylaminoxy, ketoniminoxy and aldiminoxy radicals, the symbol Q'' represents a methyl or ethyl radical, the symbol n represents a number from 1 to 4 and the symbol p represents 1 or 2, (d) a tin, titanium or iron catalyst, (e) optionally a specified silicon containing vulcanisation accelerator and (f) an organic solvent are rendered more storage stable by incorporation of a hydroxylic methylpolysiloxane oil containing at least 3 percent by weight of hydroxyl groups, of viscosity between 3 and 400 cPo at 25*C, of the average general formula IN WHICH THE SYMBOL A REPRESENTS A NUMBER FROM 1.7 TO 2.3 AND THE SYMBOL B REPRESENTS A NUMBER FROM 0.14 TO 1. The compositions can be applied to sheets or films of various materials to render the surface non-stick when in contact with tacky substances.
A composition according to claim 1, wherein the hydroxylic methylpolysiloxane oil is an Alpha , omega -dihydroxydimethylpolysiloxane oil of viscosity 50 cPo at 25*C, containing 13 percent by weight of hydroxyl groups.
Claim 2
Dependent Claim
32 words
A composition according to claim 1, wherein the hydroxylic methylpolysiloxane oil is an Alpha - omega -dihydroxydimethylpolysiloxane oil of viscosity 40 cPo at 25*C, containing 4 percent by weight of hydroxyl groups.
Claim 3
Dependent Claim
35 words
A composition according to claim 1, wherein the hydroxylic methylpolysiloxane oil is an oil of viscosity 37.5 cPo at 25*C, containing 6.7 percent by weight of hydroxyl groups and with a CH3/Si ratio of 1.87.
Claim 4
Dependent Claim
24 words
A composition according to claim 1 containing 7-26 parts by weight of the hydroxylic methylpolysiloxane oil per 100 parts by weight of component (a).
Claim 5
Dependent Claim
21 words
A composition according to claim 1 wherein the viscosity of component (a) at 25*C is about 100,000 to 5 million cPo.
Claim 6
Dependent Claim
43 words
A composition according to claim 1 wherein the viscosity of component (b) at 25*C is about 2 million to 50 million cPo and component (b) is present in an amount of 40-230 parts by weight per 100 parts by weight of component (a).
Claim 7
Dependent Claim
12 words
A composition according to claim 1 wherein component (c) is (CH3OCH2CH2O)4Si (C2H5)2NOSi(OCH2CH2OCH3)3
Claim 8
Dependent Claim
12 words
A composition according to claim 1 wherein component (d) is dibutyl-tin dilaurate
Claim 9
Dependent Claim
31 words
A composition according to claim 1 wherein component (e) is methyltriacetoxysilane or vinyltriacetoxysilane present in an amount up to 8 parts by weight per 100 parts by weight of component (a).
Claim 10
Dependent Claim
37 words
A composition according to claim 1 wherein component (f) is toluene, methylcyclohexane or an alkane mixture of b.p. about 93*-114*C present in an amount of 1,000-4,500 parts by weight per 100 parts by weight of component (a).