Hard organopolysiloxane release coating

Claim 1

A composition of matter comprising (A) 100 parts by weight of a hydroxyfunctional polysiloxane resin copolymer containing CH 3 SiO 3/2 units, C 6 H 5 SiO 3/2 units, (C 6 H 5 ) 2 SiO units and C 6 H 5 (CH 3 )SiO units wherein there is present 0.5 to 5 weight percent hydroxy radicals attached to silicon atoms, the organic group to silicon ratio is from 0.8 to 1.4 and the C 6 H 5 ― to silicon ratio is from 0.35 to 0.85; (B) from 4 to 240 parts by weight, based on 100 parts of (A), of CH 3 SiO 3/2 which is a residual product derived from the alkoxysilane CH 3 Si(OCH 3 ) 3 ; (C) from 0.2 to 6 parts by weight, based on 100 parts of (A), of a fluid polysiloxane having the formula wherein x has a value of from 250 to 850, R is OH or CH 3 - and R' and R" are CH 3 ―, wherein there is present in component (C), less than fifteen percent by weight of (CH 3 ) 3 SiO units; and (D) from 0.48 to 6 parts by weight, based on 100 parts of (A), of a silanol condensation catalyst.

Claim 8

A method of enhancing release from the surface of a solid substrate which method comprises (i) coating a solid substrate with a composition of matter comprising (A) 100 parts by weight of a hydroxyfunctional polysiloxane resin copolymer containing CH 3 SiO 3/2 units, C 6 H 5 SiO 3/2 units, (C 6 H 5 ) 2 SiO units and C 6 H 5 (CH 3 )SiO units wherein there is present 0.5 to 5 weight percent hydroxy radicals attached to silicon atoms, the organic group to silicon ratio is from 0.8 to 1.4 and the C 6 H 5 ― to silicon ratio is from 0.35 to 0.85; (B) from 4 to 240 parts by weight, based on 100 parts of (A), of CH 3 Si0 3/2 , which is a residual product derived from the alkoxy silane CH 3 Si(OCH 3 ) 3 ; (C) from 0.2 to 6 parts by weight, based on 100 parts of (A), of a fluid polysiloxane having the formula wherein x has a value of from 250 to 850, R is OH or CH 3 - and R' and R" are CH a -, wherein there is present in component (C), less than fifteen percent by weight of (CH 3 ) 3 SiO units; and (D) from 0.48 to 6 parts by weight, based on 100 parts of (A), of a silanol condensation catalyst and, (ii) curing the coating, whereupon a solid substrate, having enhanced release, is obtained.

Claim 9

A method of enhancing release from the surface of a solid substrate which method comprises (i) coating a solid substrate with a composition of matter comprising (A) 100 parts by weight of a hydroxyfunctional polysiloxane resin copolymer containing CH 3 SiO 3/2 units, C 6 H 5 SiO 3/2 units, (C 6 H 5 ) 2 SiO units and C 6 H 5 (CH 3 )SiO units wherein there is present 0.5 to 5 weight percent hydroxy radicals attached to silicon atoms, the organic group to silicon ratio is from 0.8 to 1.4 and the C 6 H 5 ― to silicon ratio is from 0.35 to 0.85; (B) from 4 to 240 parts by weight, based on 100 parts of (A), of CH 3 Si0 3/2 , which is a residual product derived from the alkoxy silane CH 3 Si(OCH 3 ) 3 ; (C) from 0.2 to 6 parts by weight, based on 100 parts of (A), of a fluid polysiloxane having the formula wherein x has a value of from 250 to 850, R is OH or CH 3 - and R' and R" are CH a -, wherein there is present in component (C), less than fifteen percent by weight of (CH 3 ) 3 SiO units; and (D) from 0.48 to 6 parts by weight, based on 100 parts of (A), of a silanol condensation catalyst and, (ii) curing the coating, whereupon a solid substrate, having enhanced release, is obtained.