Silicone release coating compositions
AssigneeDow Corning Corporation
InventorsStephen Edward Cray, John Francis
Life of this patent
Estimating the term…
Abstract
A branched siloxane contains at least three aliphatically unsaturated hydrocarbon groups, is terminated by units of the formula RaRb2SiO1/2 and otherwise consists of: i) one or more units of the formula(SiO4/2); and ii) from 15 to 995 units of the formula Rb2SiO2/2 which units (i) and (ii) may be inter-linked in any appropriate combination. The invention includes a method of making the branched siloxane and release coating and release modifier compositions containing the branched siloxane.
Claims9
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 Si—H groups in the composition to aliphatically unsaturated hydrocarbon groups in the composition is from 0.9:1 to 3:1.
A multi-pack release coating composition comprising a first pack comprising a branched siloxane consisting of (a) at least one Q unit of tho 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 catalyst, a second pack comprising a silicone release modifier and catalyst, and a third pack comprising an organohydrogenpolysiloxane cross-linking agent and hydrosilylation inhibitor.
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, and a fourth pack comprising an organohydrogenpolysiloxane cross-linking agent.
Dependencies are inferred from the claim text.