| 摘要 |
The present invention is a rubber composition for tire treads, of which the temperature of the peak position of the temperature curve of tan´ is -16.0°C or higher and -6.0°C or lower, tan´ at the peak position is larger than 1.13, tan´ at 0°C is 0.95 or more, and the value obtained by dividing the absolute value of the difference between tan´ at -5°C and tan´ at 5°C by the temperature difference between -5°C and 5°C {| (tan´ at -5°C) - (tan´ at 5°C) |/10} (/°C) is smaller than 0.045/°C. The invention is also a rubber composition containing a rubber component that contains at least two types of styrene-butadiene copolymer rubbers differing in the bound styrene content therein, and a filler; the composition being a rubber composition for tire treads, in which the difference between the bound styrene content St(A) of the styrene-butadiene copolymer rubber (A) having a high bound styrene content and the bound styrene content St (B) of the styrene-butadiene copolymer rubber (B) having a low bound styrene content {St (A) - St(B)} is from 6 to 22% by mass, and of which tan´ at 0°C is 0.95 or more, and the value obtained by dividing the absolute value of the difference between tan´ at -5°C and tan´ at 5°C by the temperature difference between -5°C and 5°C {|(tan´ at -5°C) - (tan´ at 5°C) |/10} (/°C) is smaller than 0.045/°C. The invention provides the rubber compositions for tire treads that more highly satisfy both low-heat-generation property and wet braking performance. |
