Blockcopolymere und ihre Verwendung zur Herstellung von Kautschukmassen

摘要

1298813 Block copolymers ASAHI KASEI KOGYO KK 12 Dec 1969 [16 Dec 1968] 60782/69 Headings C3P and C3Q Block copolymers of a conjugated diolefin and a total of 15-35% by weight of a marovinyl aromatic hydrocarbon consists of blocks of a random copolymer of a conjugated diolefin and 1-20% by weight of monovinyl aromatic hydrocarbon and blocks of a random copolymer of conjugated diolefin and 25-50% by weight of monovinyl aromatic hydrocarbons and containing no more than 5% of monovinyl aromatic hydrocarbon homopolymer block, said copolymers being polymerized with a lithium based catalyst. The block copolymers may be formed into compositions with process oil, fillers and optionally natural rubber or synthetic rubbers to form a rubbery composition suitable for tyre treads. In the examples block copolymers of 1,3-butadiene and styrene or isoprene and styrene are prepared by a two-stage process in the presence of n-butyl lithium as a catalyst and hexane as solvent, optionally including tetrahydrofuran as a randomizing agent. A butadiene/styrene copolymer formed in this way is formed into a composition with commercial polybutadiene.