BRANCHED STYRENE-BUTADIENE COPOLYMER RUBBER COMPOSITION

摘要

PURPOSE:To prepare the titled composition having excellent moldability and impact resilience, by compounding a specific styrene-butadiene copolymer with a low molecular weight butadiene copolymer at a specific ratio. CONSTITUTION:The objective composition is prepared by compounding (A) a styrene-butadiene copolymer having Mooney viscosity (ML1+4, 100 deg.C) of 50-130 and bonded styrene content of 5-40wt% and containing >=30wt% of branched styrene-butadiene copolymer wherein the bond at the branched part is tin-butadienyl bond with (B) a low molecular weight butadiene (co)polymer having a viscosity-average molecular weight of 15,000-120,000 and a glass transition temperature of <=-30 deg.C. The weight ratio of A/B is 100/(10-60), and the Mooney viscosity of the composition is 30-80.