Catalytic copolymerisation of 4-methylpentene.

摘要

A copolymer is produced by copolymerizing 4-methyl-pentene-1 with another C2-20 alpha -olefin in a hydrocarbon solvent which can be the monomer, in the presence of a Ziegler-Natta catalyst (e.g. TiCl3 and an alkyl aluminium halide). In a first stage a homopolymer or random copolymer of 4-methylpentene-1 having an alpha -olefin content of not more than 3 mol% and an intrinsic viscosity of at least 2.5 dl/g is formed, and in a second stage a random copolymer having an alpha -olefin content higher than that of the first polymer and no higher than 9 mol% and an intrinsic viscosity of at least 2.5 dl/g is formed, and the produced copolymer insoluble in the solvent is separated to recover a 4-methylpentene-1 copolymer containing from 5 to 80% by weight of the first polymer. Polymerization is at 0-90 DEG C, at atmospheric to 5 kg/cm<2> pressure. The process produces a solvent-insoluble copolymer in an increased yield without impairing transparency of the copolymer. If the copolymer is not moldable, its molecular weight is reduced by decomposition at 250-330 DEG C or with a peroxide catalyst.