Patent ID: 7829621

Claim:
A rubber composition comprising: a diene rubber, 50 to 120 parts by weight of a reinforcing filler containing carbon black based on 100 parts by weight the diene rubber, of which a nitrogen adsorbing-specific surface area is 100 to 250 m 2 /g, an iodine adsorption amount is 110 to 200 mg/g and a ratio of cetyltrimethylammonium bromide adsorbing-specific surface area to the iodine adsorption amount is 0.85 to 1.2 and 10 to 100 parts by weight of silica based on 100 parts by weight of the diene rubber; 2 to 50 parts by weight of a styrene-butadiene polymer of which the weight average molecular weight is 1,000 to 15,000, the amount of a styrene is 17 to 27% by weight and the amount of vinyl contribution from butadiene is 60 to 80% by weight: and 2 to 25 parts by weight of an indene resin, of which the melting point is 100 to 150° C. based on 100 parts by weight of the diene rubber which comprises 60 to 95% by weight of a solution polymerization styrene-butadiene rubber, wherein weight average molecular weight is 500,000 to 2,500,000, the amount of styrene is 20 to 40% by weight and the amount of vinyl contribution from butadiene is 30 to 60% by weight and 5 to 40% by weight of a natural rubber and/or a butadiene rubber, and the rubber composition further comprising 2 to 12 parts by weight of a silane coupling agent represented by the following formula: (C n H 2n+1 O) 3 —Si—(CH 2 ) m —S 1 —(CH 2 ) m —Si—(C n H 2n+1 O) 3 wherein n is an integer of 1 to 3, m is an integer of 1 to 4 and the average value of 1 is 1.8 to 3.5 based on 100 parts by weight of said silica, and the rubber composition is obtained by kneading at a condition of at least 150° C.