| 摘要 |
PROBLEM TO BE SOLVED: To provide a rubber composition having good processability, high wear resistance, and high breaking properties before and after aging. SOLUTION: The rubber composition is obtained by blending 100 pts.wt. of a rubber component containing (i) 70-20 pts.wt. of an NR and/or an IR, (ii) 30-80 pts.wt. of a BR having a Mooney viscosity of 50 or higher, and (iii) 0.5-5.0 pts.wt. of an A-B type block copolymer having an Mw of 30,000 to 200,000 with (C) a vulcanization accelerator, (D) sulfur, and (E) 60-90 pts.wt. of a CB of an HAF grade or higher. The block copolymer consists of (A) poly(styrene-butadiene) blocks having a styrene content (ST) of 2-35 wt.%, a butadiene content of 65-98 wt.%, and a 1, 2-vinyl linkage content (VN) of 5-80 mol% and satisfying the relation of the formula: VN≤2ST+30 and (B) polyisoprene blocks having a cis-linkage content of 70 wt.% or higher. The weight ratio of the blocks (A) to the blocks (B) is (20:80) to (80:20). The weight ratio of the vulcanization accelerator (C) to the sulfur (D) is (0.8 to 1.5):1. COPYRIGHT: (C)2004,JPO
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