| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition for a tire tread having long scorch time while securing dispersibility of silica.SOLUTION: A rubber composition for a tire tread contains diene rubber, silica and a silane coupling agent, and the silane coupling agent is polysiloxane represented by the average composition formula of the formula (1), the content of the silica is 5 to 150 pts.mass based on 100 pts.mass of the diene rubber, and the content of the silane coupling agent is 1 to 20 mass% based on the content of the silica. (A)(B)(C)(R)(R)SiO(1), where A represents an organic group containing a mercapto group, B represents an organic group having S-Si bond, C represents a hydrolyzable group, Rrepresents a monovalent hydrocarbon group having 4 to 10 carbon atoms, Rrepresents a monovalent hydrocarbon group having 1 to 3 carbon atoms, and a to e satisfy relational expressions 0≤a<1, 0<b<1, 0<c<3, 0≤d<1, 0≤e<2 and 0<a+b+c+d+e<4. |
