Rubber compositions of ethylene-propylene elastomers
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsKunio Itoh, Toshimichi Oshima, Nobuyuki Uesugi
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Abstract
The invention provides a novel rubber composition based on an ethylene-propylene copolymeric rubbery elastomer and curable by hot air vulcanization under atmospheric pressure giving great advantages over conventional ones vulcanizable only under pressure. The inventive rubber composition comprises, in addition to the ethylene-propylene copolymeric rubbery elastomer, an oganopolysiloxane gum having alkenyl or mercapto groups in the molecule, a reinforcing silica filler, an organic compound having at least two maleimido groups in a molecule and a curing agent which is an organic peroxide or an organic sulfur compound.
Claims3
A curable rubber composition which comprises
- (a) 100 parts by weight of a mixture composed of
- (a-1) from 40 to 99% by weight of an ethylene-propylene copolymeric elastomer, and
- (a-2) from 60 to 1% by weight of an organopolysiloxane gum having an average degree of polymerization of at least 1000 and containing at least one alkenyl group in a molecule,
- (b) from 10 to 150 parts by weight of a reinforcing silica filler having a specific area of at least 50 m.sup.2 /g,
- (c) from 0.5 to 10 parts by weight of N,N'-m-phenylene bismaleimide or N,N'-(2,4-tolylene)dimaleimide,
- (d) from 0.1 to 10 parts by weight of a curing agent.
Dependencies are inferred from the claim text.