RUBBER COMPOSITION FOR TIRE, AND PNEUMATIC TIRE

WIPO Patent Application WO/2013/157545

A1

Provided is a rubber composition for tires which has been configured so as to attain further improvements in low rolling resistance, wet grip performance, and wear resistance as compared with conventional levels. The rubber composition is characterized by comprising 100 parts by weight of a diene rubber including 5-50 wt% modified butadiene rubber (BR) that has a vinyl unit content of 10-60 wt%, 2-50 parts by weight of an aromatic-modified terpene resin that has a softening point of 100-130ºC, and 60-130 parts by weight of the sum of two silicas, silica X and silica Y. The rubber composition is further characterized in that the proportion of the silicas in the whole reinforcing filler that may include carbon black is 85 wt% or higher, the silica X has a nitrogen-adsorption specific surface area of 140 m2/g or larger, the silica Y has a nitrogen-adsorption specific surface area larger than 100 m2/g but less than 140 m2/g, and the silica X and the silica Y satisfy the relationship x/7