Rubber composition with nitrogen and phosphorous compound

Claim 1

A rubber composition containing (A) a bismaleimide compound represented by the general formula (I) ##STR7## wherein R is a divalent acyclic aliphatic group, cyclic aliphatic group, aromatic group, or alkylaromatic group, and wherein these groups may contain a hetero atom selected from O, N and S, (B) a sulfenamide compound represented by the general formula (II) ##STR8## wherein R 1 and R 2 denote independently from each other a hydrogen atom, an acyclic aliphatic group, or cyclic aliphatic group, or R 1 and R 2 together denote a chain aliphatic group which may contain an oxygen atom, provided that R 1 and R 2 cannot simultaneously denote a hydrogen atom, (C) a dithiophosphoric acid compound represented by the general formula (III) ##STR9## wherein R 3 and R 4 denote each an aliphatic group, and (D) sulfur, wherein the rubber is at least one member selected from the group consisting of styrene-butadiene rubber, butadiene rubber, isoprene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene-diene terpolymer, and isopreneisobutylene rubber, and which composition contains 0.1 to 8 parts by weight of the bismaleimide compound (I), 0.1 to 8 parts by weight of the sulfenamide compound (II), 0.3 to 6 parts by weight of the dithiophosphoric acid compound (III), and 0.1 to 14 parts by weight of sulfur, each based on 100 parts by weight of rubber.