Rubber composition for tire tread

摘要

A rubber composition comprises a diene rubber including not less than 25% by weight of a modified conjugated diene polymer rubber and, per 100 parts by weight of the diene rubber, from 25 to 65 parts by weight of a filler, the filler comprising not less than 50% by weight of silica. The silica has a DBP absorption number of 190 to 250 ml/100 g, an N2SA of 194 to 225 m/g, and a CTAB of 185 to 215 m2/g. A ratio of the N2SA to the CTAB is from 0.9 to 1.4. The modified conjugated diene polymer rubber has a terminal modified group including a functional group that interacts with the silica. In the modified conjugated diene polymer rubber, aromatic vinyl unit content is from 38% to 48% by weight, vinyl unit content is from 20% to 35%, and weight-average molecular weight is from 600,000 to 1,000,000.

主权项

1. A rubber composition for use in tire treads comprising a diene rubber including 40 to 80% by weight of a modified conjugated diene polymer rubber and, per 100 parts by weight of the diene rubber, from 25 to 65 parts by weight of a filler; the filler comprising not less than 50% by weight of silica; the silica having a DBP absorption number of 190 to 250 ml/100 g, a nitrogen specific surface area (N2SA) of 194 to 225 m2/g, and a CTAB specific surface area (CTAB) of 185 to 215 m2/g; a ratio of the N2SA to the CTAB (N2SA/CTAB) being from 0.9 to 1.4; the modified conjugated diene polymer rubber being obtained by copolymerizing a conjugated diene monomer unit and an aromatic vinyl monomer unit in a hydrocarbon solvent using an organic active metal compound as an initiator; a resulting active conjugated diene polymer chain thereof having a terminal modified group, obtained by reacting the active terminal of the polymer chain with at least one type of compound having a functional group that is reactable with the active terminal of the polymer chain; the terminal modified group having a functional group that interacts with the silica; and, in the modified conjugated diene polymer rubber, aromatic vinyl unit content being from 40% to 45% by weight, vinyl unit content being from 26% to 34%, and weight-average molecular weight being from 650,000 to 850,000.