Patent ID: 6764717
Filing Date: 2004-07-20
Classification: C08G,C09D,Y10T

Abstract:
In a process for reducing aerosol in applying a crosslinkable silicone coating composition onto a substrate wherein an antimisting additive is added to the coating composition, the improvement comprising adding to said crosslinkable silicone coating composition from 0.5 to 10.0 weight percent of an antimisting additive comprising at least one alkenyl-functional siloxane copolymer prepared byreacting, in a first step a compound (1) containing at least three aliphatic double bonds, of the formula R2(CR3&boxH;CH2)xâ€ƒâ€ƒ(I) where R2 is a trivalent or tetravalent hydrocarbon radical optionally containing one or more non-adjacent oxygen, silicon, or titanium heteroatoms, R3 is a hydrogen atom or alkyl radical, and x is 3 or 4 with an organosiloxane (2) having terminal Si-bonded hydrogen atoms, in the presence of at least one hydrosilylation catalyst (3), the ratio of Si-bonded hydrogen in the organosiloxane (2) to aliphatic double bond in organic compound (1) being from 1.3 to 10, and reacting, in a second step, SiH-containing hydrocarbon-siloxane copolymer(s) obtained in the first step with at least one &agr;,&ohgr;-dialkenylsiloxane polymer (4), in the presence of a hydrosilylation catalyst (3), the ratio of aliphatic double bond in the &agr;,&ohgr;-dialkenylsiloxane polymer (4) to SiH groups in the hydrocarbon-siloxane copolymer(s) being from 1.2 to 10, and optionally, in a third step, equilibrating alkenyl-functional siloxane copolymer(s) obtained from the second step with one or more organopolysiloxane(s) (5) selected from the group consisting of linear organopolysiloxanes containing terminal triorganosiloxy groups, linear organopolysiloxanes containing terminal hydroxyl groups, branched organopolysiloxanes optionally containing hydroxyl groups, cyclic organopolysiloxanes, and copolymers comprising diorganosiloxane and monoorganosiloxane units, and crosslinking said composition on said substrate, wherein said weight percents are based on the total weight of the crosslinkable coating composition and the antimisting additive.