Patent ID: 6806339
Filing Date: 2004-10-19
Classification: C08G,C09D

Abstract:
A multi-pack release coating composition comprising a first pack comprising a branched siloxane consisting of (a) at least one Q unit of the formula (SiO4/2) and (b) from 15 to 995 D units of the formula Rb2SiO2/2 which units (a) and (b) may be inter-linked in any appropriate combination, and (c) M units of the formula RaRb2SiO1/2, wherein each Ra substituent is selected from the group consisting of an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 1 to 6 carbon atoms and an alkynyl group having from 1 to 6 carbon atoms, at least three Ra substituents in the branched siloxane being alkenyl or alkynyl units, and each Rb substituent is selected from the group consisting of an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group, an alkoxy group, an acrylate group and a methacrylate group, and a hydrosilylation inhibitor, a second pack comprising a silicone release modifier and hydrosilylation inhibitor, a third pack comprising a hydrosilylation catalyst in a sufficient amount to catalyse the reaction between the branched siloxane and a cross-linking agent and a fourth pack comprising the organohydrogenpolysiloxane cross-linking agent in an amount such that the ratio of the total number of Siâ€”H groups in the composition to aliphatically unsaturated hydrocarbon groups in the composition is from 0.9:1 to 3:1.