Patent ID: 6387487
Filing Date: 2002-05-14
Classification: C08G,C08L,C09J,Y10T

Abstract:
A curable silicone coating composition, comprising:(A) about 20 to about 80 parts by weight of an alkenyl-terminated polydiorganosiloxane of formula (I) R2R12SiO(R12SiO)mSiR12R2â€ƒâ€ƒ(I) wherein each R1 is independently an alkyl group having from 1 to about 10 carbon atoms or an aryl group, R2 is an alkenyl group having from 1 to about 10 carbon atoms, and m has an average value of about 20 to about 2000; (B) about 2 to about 80 parts by weight of a silanol-terminated polydiorganosiloxane of formula (II) R12Si(OH)O(R12SiO)pSiR12(OH)â€ƒâ€ƒ(II) wherein each R1 is independently an alkyl group as defined above, and the average value of p is chosen to provide a viscosity of about 100,000 centipoise to about 750,000 centipoise; (C) about 20 to about 80 parts by weight of a resinous copolymer containing R3SiO1/2 units and SiO4/2 units, where R is a hydrocarbon monovalent radical having from 1 to about 6 carbon atoms, said resinous copolymer having a molar ratio of R3SiO1/2 units to SiO4/2 units of about 0.6 to about 0.9; (D) an organohydrogenpolysiloxane of formula (III) R32HSiO(R32SiO)qSiHR32â€ƒâ€ƒ(III) wherein each R3 is independently an alkyl group having 1 to about 10 carbon atoms or an aryl group; q has an average value of 1 to about 300; the molar ratio of silicon-bonded hydrogen groups in (D) to silicon-bonded alkenyl groups in (A) being about 0.8:1 to about 1.5:1; (E) a catalytic amount of a hydrosilation catalyst; and (F) about 0.2 to about 6 parts by weight of a cross-linking agent comprising an organic peroxide or an organic azo compound; wherein all parts by weight are based on the weight of the entire composition.