Heat-resistant rubber compositions

摘要

Disclosed is a heat-resistant rubber composition comprising (A) 100 parts by weight of an ethylene/ alpha -olefin copolymer or a modified ethylene/ alpha -olefin copolymer formed by graft-copolymerization with at least one compound selected from the group consisting of unsaturated carboxylic acids and anhydrides and esters thereof, and (B) (i) 10 to 100 parts by weight of a silica type filler which has been treated with a silane compound represented by the following formula: <IMAGE> (I) wherein R1 stands for an alkenyl group, a chloroalkenyl group or a chloroalkyl group, and R2 stands for a lower alkyl group, or (ii) a combination of 10 to 100 parts by weight of said silane-treated silica type filler or an untreated silica type filler and 0.5 to 30 parts by weight of a polyorganosiloxane having an average composition represented by the following formula: (R3)a(R4)bSiO(4-a-b)/2(II) wherein R3 stands for a monovalent saturated or unsaturated hydrocarbon group, R4 stands for a chloroalkyl group or an alkenyl group, a is a number of from 1 to 2.5 and b is a number of from 0.01 to 1.2, with the proviso that the sum of a and b is in the range of from 1.8 to 3.