| 摘要 |
PROBLEM TO BE SOLVED: To obtain a rubber compsn. which is excellent in workability and gives a pneumatic tire improved in abrasion resistance and uniformity by compounding a specific copolymer rubber, another diene rubber, silica, a carbon black, and a silane coupling agent. SOLUTION: This compsn. is prepd. by compounding (A) 100 pts.wt. rubber blend comprising 55 pts.wt. or above of a copolymer rubber having a glass transition point of -60 deg.C or higher and a vinyl content of butadiene parts of 40-70% and obtd. by copolymerizing 15-30 wt.% styrene and 1,3-butadiene in the presence of an organolithium compd. and 45 pts.wt. or below of other diene rubber with (B) 20-100 pts.wt. silica, (C) 0-100 pts.wt. carbon black, and (D) a silane coupling agent which is represented by the formula (wherein (n) is 1-3; (m) is 1-9; and (y) is 1 or higher) and has a trisulfide silane content (based on the total polysulfide silane content) of 25% or above and a content of higher polysulfide silanes (having (y) of 5 or higher) of 50% or below the amt. of D being 1-20 wt.% of B and the wt. ratio of B/C being (1/1)-(1/0). |
