RUBBER COMPOSITION FOR TIRE TREAD

摘要

Provided is a rubber composition for tire treads which brings about lower rolling resistance and better control stability than on the conventional levels. This rubber composition is characterized by comprising 100 parts by weight of a diene rubber containing at least 40 wt.% modified conjugated-diene polymer rubber and 66-110 parts by weight of a filler, the filler comprising at least 50 wt.% silica. The composition is further characterized in that the modified conjugated-diene polymer rubber has modifying end groups obtained by reacting at least one compound with active conjugated-diene polymer chains obtained by copolymerizing a conjugated-diene monomer and an aromatic vinyl monomer in a hydrocarbon solvent using an organic active metal compound as an initiator, the at least one compound having a functional group reactive with the active ends of the polymer chains, the modifying end groups including a functional group that interacts with silica, and that the modified conjugated-diene polymer rubber has an aromatic-vinyl unit content of 38-48 wt.%, a vinyl unit content of 20-35%, and a weight-average molecular weight of 600,000-1,000,000.