Patent ID: 7304109

Claim:
A rubber composition comprising (B) 10 to 200 parts by weight of a low molecular weight aromatic vinyl-conjugated diene copolymer having weight average molecular weight of 1.0×10 3 to 1.0×10 5 and aromatic vinyl content of 10 to 75% by weight, wherein the hydrogenation ratio of double bonds in the conjugated diene part is 20 to 55%, based on (A) 100 parts by weight of a rubber component containing at least 60% by weight of a styrene-butadiene copolymer having weight average molecular weight of 5.0×10 5 to 2.5×10 6 and styrene content of 10 to 60% by weight, wherein the amount of vinyl bonds in the butadiene part is 20 to 70%; which satisfies the following relationship 5% by weight< Bv <( As +10% by weight) when As (% by weight) is the styrene content of said styrene-butadiene copolymer (A) and Bv (% by weight) is the aromatic vinyl content of said low molecular weight aromatic vinyl-conjugated diene copolymer (B).