ONE-PART ORGANOPOLYSILOXANE RUBBER FOR HIGH VOLTAGE ELECTRICAL INSULATOR

摘要

The present invention relates to a one-part room temperature vulcanizable organopolysiloxane rubber composition which is VOC free and crosslinks in the presence of moisture to form a coating for the protection of composite high voltage electrodes. The one-part organopolysiloxane rubber composition comprises the product which is obtained by mixing the following: ;a) from about 20 to about 60 weight percent of one or more polydiorganosiloxane fluids having a viscosity from about 10 to about 100,000 centipoise at 25° C.; ;b) from 0 to about 40 weight percent of a cyclo-organosiloxane; ;c) from 0 to about 40 weight percent of an inorganic extending or non-reinforcing filler; ;d) from about 0.5 to about 15 weight percent of an amorphous SiO₂ reinforcing filler; ;e) from about 1 to about 7 weight percent of an oximinosilane cross-linking agent; ;f) from about 0.2 to about 3 weight percent of an adhesion promoter; ;g) from about 0.02 to about 3 weight percent of an organotin salt as a condensation catalyst; and ;h) from about 20 to about 50 weight percent of alumina trihydrate, the alumina trihydrate having a median particle size of 10 &mgr;m to 30 &mgr;m, containing 65.1 percent Al₂O₃, 34.5 percent combined H₂O, 0.3 percent Na₂O, 0.02 percent CaO, 0.01 percent SiO₂ and having a specific gravity of 2.42.