Patent ID: 8440757

Claim:
A rubber composition for a tire tread comprising a diene rubber component and silica and carbon black, the diene rubber component comprising: (A) from 30 to 80 mass % of a hydroxy group-containing aromatic vinyl-conjugated diene copolymer comprising from 20 to 30 mass % of aromatic vinyl units and from 0.1 to 10 mass % of isoprene units, and having an amount of vinyl bonds in a conjugated diene part from 40 to 60 mol %; (B) from 10 to 50 mass % of a high-cis butadiene rubber having an amount of 90 mol % or more of cis-1,4 bonds; and (C) from 10 to 50 mass % of natural rubber; wherein a total amount of silica and carbon black is from 90 to 150 parts by mass per 100 parts by mass of the diene rubber component, and wherein the high-cis butadiene rubber (B) is obtained by blending a high molecular weight butadiene rubber having a weight-average molecular weight of from 5.0×10 5 to 1.0×10 6 and a low molecular weight butadiene rubber having a weight-average molecular weight of from 6.0×10 3 to 6.0×10 4 in a solvent; and an amount of the low molecular weight butadiene rubber included is from 20 to 40 mass %.