| abstract |
A rubber composition comprising (A) a nitrilengroup-containing copolymer rubber, (B) a metal salt of annethylenically unsaturated carboxylic acid and (C) an organicnperoxide, wherein the rubber (A) comprises 10-40 wt.% of (a) α,β-ethylenically unsaturated nitrite monomer units, 10-60 wt.%nof (b) α,β-ethylenically unsaturated carboxylic acid esternmonomer units, 0.01-56 wt. % of (c) conjugated diene monomer units,nand 14-69.99 wt.% of (d) saturated conjugated diene monomernunits; the sum of monomer units (c) and monomer units (d) is 20-70nwt.%, and the ratio of monomer units (d) to the sum of monomernunits (c) and monomer units (d) is at least 70 wt.%; the differencenbetween the extrapolated glass transition initiation temperaturen(Tig) and the extrapolated glass transition ending temperaturen(Teg) as measured on rubber (A) by differential scanningncalorimetry is not larger than 10°C. The rubber compositionngives a vulcanizate having excellent cold resistance and oilnresistance, and reduced compression set. |