| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition for a tread capable of improving high mileage, wet grip performance and wear resistance in a good balance, and a pneumatic tire using the composition.SOLUTION: The rubber composition for a tread comprises a rubber component, silica (1) having a nitrogen adsorption specific surface area of 100 m/g or less, and silica (2) having a nitrogen adsorption specific surface area of 180 m/g or more. In 100 mass% of the rubber component, the following conjugate diene polymer is included by 5 mass% or more: the conjugate diene polymer has a structural unit based on a conjugate diene and a structural unit based on a compound expressed by a formula (1). The composition contains, with respect to 100 parts by mass of the rubber composition, 10 to 150 parts by mass of the silica (1) and silica (2) in total, and the content of the silica (1) and the silica (2) satisfies an expression of: (content of silica (1))×0.2≤(content of silica (2))≤(content of silica (1))×6.5. In the formula, m represents a number from 1 to 3; Rrepresents a hydrocarbyl group having a polymerizable carbon-carbon double bond; Rrepresents a hydrocarbylene group and when a plurality of Ris present, the plurality of Rmay be the same or different; A represents a substituted amino group and when a plurality of A is present, the plurality of A may be the same or different; and Rrepresents a hydrocarbyl group, a substituted hydrocarbyl group or a substituted amino group and when a plurality of Ris present, the plurality of Rmay be the same or different. |
