Novel organopolysiloxane compositions useful as mold release coatings

Claim 2

An organopolysiloxane composition comprising: (A) 100 parts of a diorganopolysiloxane oil of the average general formula: G(CH.sub.3).sub.2 Si[OSi(CH.sub.3)R].sub.x [OSi(CH.sub.3).sub.2 ].sub.y OSi(CH.sub.3).sub.2 G in which the symbols R, which are identical or different, are each an alkyl radical containing from 7 to 15 carbon atoms, or a phenylalkyl radical, the alkyl moiety of which contains from 1 to 6 carbon atoms; the symbol G is R or a hydroxy or methyl radical; the symbol x is any number ≧6; the symbol y is zero or any number which does not exceed 3/4 of the value of x, with the sum x+y being such that said oil has a viscosity of 50 to 5,000 mPa.s at 25° C.; (B) 15 to 80 parts of an organopolysiloxane copolymer comprising recurring units of the formulae (CH 3 ) 3 SiO 0 .5 and SiO 2 , distributed such that the molar ratio (CH 3 ) 3 SiO 0 .5 /SiO 2 ranges from 0.4 to 1.2; and (C) 200 to 2,000 parts of an inert organic diluent.

Claim 3

The organopolysiloxane composition as defined by claim 1, wherein said oil (A) comprises an oil having one of the formulae: P1: (CH 3 ) 3 Si[OSi(CH 3 )n-octyl] x1 OSi(CH 3 ) 3 P2: (CH 3 ) 3 Si[OSi(CH 3 )CH 2 CH 2 C 6 H 5 ] x2 OSi(CH 3 ) 3 P3: (CH 3 ) 3 Si[OSi(CH 3 )2-ethylhexyl] x3 OSi(CH 3 ) 3 P4: (CH 3 ) 3 Si[OSi(CH 3 )n-decyl] x4 [OSi(CH 3 )n-tetradecyl] x5 [OSi(CH 3 )CH 2 CH(CH 3 )C 6 H 5 ] x6 OSi(CH 3 ) 3 P5: (CH 3 ) 2 n-octyl Si[OSi(CH 3 )n-octyl] x7 [OSi(CH 3 ) 2 ] yl OSi n-octyl(CH 3 ) 2 in which formulae each of the symbols x1 to x7 and y1 is a value such that the polymers P1 to P5 have the following viscosities, in mPa.s at 25° C.: ______________________________________ P1: 400 to 900; P2: 500 to 950; P3: 300 to 800; P4: 600 to 1,200; P5: 450 to 1,000. ______________________________________

Claim 4

The organopolysiloxane composition as defined by claim 1, said copolymer (B) comprising vinyl-containing units of the formula: ##EQU3## wherein the symbol a is 1 or 2, the amount of said vinyl-containing units ranging from 0.2 to 8% of the weight of said copolymer (B), said copolymer (B) thus comprising the recurring units ##EQU4## with the molar ratio (CH 3 ) 3 SiO 0 .5 /SiO 2 ranging from 0.4/1 to 1.2/1.

Claim 5

A mold form, the wall members thereof being provided with non-stick release coatings of the organopolysiloxane composition as defined by claim 1.

Claim 6

The mold form as defined by claim 4, said inert organic diluent having been evaporated from said organopolysiloxane composition.

Claim 7

The mold form as defined by claim 5, said release coatings being essentially uniform and having a thickness ranging from about 0.1 to 10 μm.