| 摘要 |
PURPOSE:To improve durability without entailing any damage to abrasion resistance and gripping performance, by constituting a tread with the specified compounded rubber of styrene-butadiene copolymerized rubber or its blended rubber, the specified vulcanization accelerator, a vulcanizing agent and a bismuthamide compound. CONSTITUTION:A rubber composition for a tread is constituted of compounding 0.3-3wt.p. of a vulcanization accelerator of dibenzothiazyldisulfite or the like, 0.3-3wt.p. of sulfur and 0.1-1.5wt.p. of a bismuthamid compound expressed in a chemical equation I (see illustration) to blended rubber of 100wt.p. composed of styrene-butadiene copolymerized rubber or more than 30wt.p. of this rubber and 70wt.p. of rubber selected out of natural rubber or the like. And, the sulfur and the bismuthamid compound are set to 1/1 to 3/1 while the vulcanizing agent and this bismuthamid compound are set to 1/1 to 3/1, respectively. With this constitution, durability is improved. |
