| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rubber composition for tire tread, which is improved in wet grip performance, stability thereof, and wear resistance beyond a conventional level. <P>SOLUTION: The composition includes 100 pts.wt. of diene rubber including 70 wt.% or more of styrene butadiene rubber having a glass transition temperature of -35°C or higher, 20-130 pts.wt. of silica having a BET specific surface area of 50-300 m<SP POS="POST">2</SP>/g, and 5-90 pts.wt. of carbon black, the total amount of silica and carbon black being 80-160 pts.wt. In the composition, the carbon black has CTAB adsorption specific surface area of 150-250 m<SP POS="POST">2</SP>/g and DBP absorption amount of 100-150 ml/100g, and the total of number fractions r1%, r2% of aggregates in which dimensionless numbers X, Y, Z satisfy predetermined conditions (1), (2) respectively is 70% or more and less than 80%, with r2% being larger than r1%, in which X, Y, Z are determined from maximum length L, width W, circumferential length P, projected area A and envelope area S which are determined from analysis of two-dimensional projected image of each aggregate. <P>COPYRIGHT: (C)2012,JPO&INPIT |
