| 摘要 |
<p>1492960 Catalyst composition for RTV silicone rubbers; syntactic foams GENERAL ELECTRIC CO 23 Dec 1974 [10 Jan 1974] 55516/74 Headings C3T and C3C A catalyst composition for RTV silicone rubber compositions comprises a stannous salt of C 7-12 branched chain alkane carboxylic acid dispersed in a liquid polysiloxane of the average formula wherein R is a C 4-30 alkyl radical and R<SP>1</SP> a tbutyl-hydroxy-aromatic radical, the sum of a and b being 5-40, and the ratio b : a being 0À005-0À1. The composition may be mixed with hollow microspheres, organopolysiloxanes and an organosilane to form syntactic foams. In Examples (1) a catalyst composition of 20 p.b.w. of stannous neodecanoate and 80 p.b.w. of a trimethylsilyl-terminated polymethyldecyl-siloxane containing t-butyl-hydroxy-arylpropyl radicals is used to cure a composition containing 100 p.b.w. of a polydimethylsiloxane diol, 50 p.b.w. CaCO 3 and 3 p.b.w. "Ethyl Silicate 40" to a rubber and (2) one containing 30 p.b.w. of a polydimethylsiloxane diol, 47 p.b.w. of a trimethylsilyl- and silanol-terminated polydimethylsiloxane, 2 p.b.w. of "Ethyl Silicate 40", 7 p.b.w. CaCO 3 , 8 p.b.w. of glass microballoons, 0À4 of hydrogenated castor oil and 0À6 p.b.w. of water to a foam rubber.</p> |
