Climate Change Policy and the Sustainable Future

A silicone rubber composition of the addition curing type containing an organopolysiloxane having at least two aliphatic unsaturated hydrocarbon groups in a molecule, silica, an organohydrogenpolysiloxane, a platinum catalyst, and a liquid organopolysiloxane blocked with a (CH3)3SiO+E,fra 1/2+EE unit at either end, having a monovalent hydrocarbon group (exclusive of an aliphatic unsaturated hydrocarbon group) attached to a silicon atom, provides a composition heat curable to a silicone rubber having improved weathering and tracking resistance and thus useful for high-voltage electrical insulators. Also, a silicone rubber composition containing an organopolysiloxane, an inorganic filler and an organic peroxide is improved by using as the organopolysiloxane one or more organopolysiloxanes of the formula: R6fSiO(4-f)/2, and blending therein aluminum hydroxide. There is obtained a composition which is ready for injection molding and cures into a silicone rubber having improved weathering and tracking resistance and thus suitable for high-voltage electrical insulators.