| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a rubber composition for a base tread, capable of improving high mileage property and breaking resistant strength in a good balance, and a pneumatic tire using the composition.SOLUTION: The rubber composition for a base tread comprises a rubber component, silica, and a silane coupling agent having a mercapto group. In the composition, the content of a conjugate diene polymer having a structural unit based on a conjugate diene and a structural unit based on a compound expressed by formula (1) below is 5 mass% or more in 100 mass% of the rubber component; and the content of the silica is 5 to 150 parts by mass with respect to 100 parts by mass of the rubber component. In formula (1), m represents a number of 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, pluralities of Rmay be identical or different from each other; A represents a substituted amino group, and when a plurality of A is present, pluralities of A may be identical or different from each other; and Rrepresents a hydrocarbyl group, a substituted hydrocarbyl group or a substituted amino group, and when a plurality of Ris present, pluralities of Rmay be identical or different from each other.</p> |
