Patent ID: RE43452

Claim:
A rubber composition which comprises: a rubber component comprising a styrene-butadiene copolymer rubber, or a blend of the styrene-butadiene copolymer rubber and another conjugated diene based rubber with the styrene-butadiene copolymer rubber being 70% by weight or more of the entire blend, and the entire content of styrene is 30 to 40% by weight of the entire rubber component; silica in an amount of 10 to 60 parts by weight per 100 parts by weight of the rubber component; in an amount of 1 to 20% by weight of the amount of silica, a silane coupling agent represented by following general formula (I): (C n H 2n+1 O) 3 Si—(CH 2 ) m —S y —(CH 2 ) m —Si(OC n H 2n+1 ) 3 (1) wherein n represents an integer of 1 to 3, m represents an integer of 1 to 9, y represents a positive number of 1 or more and has a distribution, and in which the content of trisulfide silane component, where y is 3, is 20% or more based on the entire amount of the silane coupling agent, and the content of high polysulfide silane components, where y is 5 or a number larger than 5, is 50% or less based on the entire amount of silane coupling agent; and carbon black, the sum of the amount of silica and carbon black being 60 to 130 parts by weight per 100 parts by weight of the rubber component.