abstract |
This invention provides organopolysiloxane elastomers exhibiting a desirable combination of high durometer hardness, tensile strength and tear strength, and a level of heat stability sufficient to retain these properties following prolonged exposure to temperatures above 150°C. The elastomers are prepared by curing a vinyl endblocked polydiorganosiloxane, an organopolysiloxane resin having a specified concentration of vinyl groups, a treated silica filler containing vinylsiloxy groups bonded to the silica particles and an organohydrogenpolysiloxane in the presence of a suitable platinum catalyst. |