Rubber compositions for use on tire ground surfaces

摘要

PURPOSE:To obtain a rubber compsn. having improved grip and wear resistance as well as improved low-temperature properties and suitable for use as a material for the tread of a tire having a high traveling performance, by blending a specified raw rubber composed of a rubber mixture with carbon black and a petroleum softener. CONSTITUTION:This rubber compsn. for a tire tread is obtd. by blending 100pts. wt. raw rubber (1) composed of 5-30pts.wt. polybutadiene rubber having a glass transition temp. of not higher than -70 deg.C, 5-50pts.wt. natural rubber or polyisoprene rubber and the balance of at least one styrene/butadiene copolymer rubber having a glass transition temp. of not lower than -50 deg.C with 80-130pts.wt. carbon black (2) having a nitrogen adsorption surface area of not smaller than 110m2/g and 20-90pts.wt. petroleum softener (3) having a viscosity-gravity constant of 0.90-0.98. The compsn. must have a storage shear modules of not higher than 500MPa.