| 摘要 |
PROBLEM TO BE SOLVED: To provide the rubber compsn. capable of realizing a sufficiently low rolling resistance without losing the wear resistance and the crack resis tance, by blending a rubber component of a blend of a natural rubber and a cis-polybutadiene at a specified ratio, with a high-structure carbon black, a silica, and a silane coupling agent. SOLUTION: A rubber compsn. for tire treads can be obtained by blending 100 pts.wt. of a rubber component consisting of 85-45 wt.% of a natural rubber and 15-55 wt.% of a polybutadiene having a cis content of 96% or more; 15-50 pts.wt. of a carbon black which has a cetyl trimethyl ammonium bromide adsorption specific surface area (CTAB value) of 70-160 m<2> /g, a dibutyl phthalate oil absorption (DBP value) of 115-180 mL/100 g, and a compression dibutyl phthalate oil absorption (24M4 DBP value) of 98-140 mL/100 g; 2-30 pts.wt. of silica; and 3-20 wt.%, based on the silica wt., of a silane coupling agent. |
