Rubber composition and rubber vibration isolator

PROBLEM TO BE SOLVED : To provide a rubber material excellent in vulcanization property, mechanical property and thermal aging property and especially suitable for vibrationproof applications.SOLUTION : There is provided a rubber composition containing (A) a diene rubber, (B) a bismaleimide compound and (C) a phenothiazine compound represented by the following formula (1). (1), where Rand Rare each independently a linear or branched alkyl group having 1 to 8 carbon atoms which may be substituted by hydrogen atom or aromatic ring, an alkoxy group having 1 to 4 carbon atoms, a halogen atom or a cyano group, Ris a hydrogen atom, a linear or cyclic alkyl group having 1 to 6 carbon atoms, a vinyl group or an aromatic group having 6 to 9 carbon atoms, m and n are each independently an integer of 0 to 2.