Process for producing rubber compositions.

摘要

A process for producing a rubber composition comprising the first step of heat-treating at 120 DEG C or more a mixture comprising of 100 parts by weight of an ethylene- alpha -olefin copolymer rubber, 0.5-5 parts by weight of at least one dinitrodiamine and at least one radical generating agent to obtain a heat-treated mixture, the second step of adding a filler to the heat-treated mixture and kneading them to obtain a rubber mixture and the third step of compounding a crosslinking agent with the rubber mixture obtained in the second step at 100 DEG C or less to obtain a rubber composition. According to said process, an ethylene- alpha -olefin copolymer rubber composition which is excellent in heat resistance and durability is obtained.