GB1111315A - A process for preparing a copolymer of vinyl chloride and ethylene - Google Patents

Abstract

Copolymers of ethylene and vinyl chloride containing 3 to 12 weight per cent of ethylene, having an inherent viscosity of at least 0.9 at 70 DEG C., and at a concentration of 0.1 gm./100 ml. cyclohexanone, and capable of being fabricated into a sheet having a surface substantially free of "nerve," may be prepared by copolymerizing the monomers in a mole ratio of 0.15 to 1.4 to a conversion of at least 5 weight per cent and thereafter terminating the copolymerization before conversion reaches 20% by injecting into the reaction mixture a compound capable of terminating the reaction. The copolymerization may be effected in bulk or solution, e.g. in inert hydrocarbons, in the presence of a catalyst comprising an organoborane and oxygen or an organic peroxide, or comprising an oil-soluble derivative of a transition metal in an oxidation state in which it is capable of reducing peroxide and a water-insoluble, oil-soluble peroxide. The reaction may be terminated by injecting a basic nitrogen compound, a phosphine or organic phosphite, or when using a transition metal catalyst a phenol, styrene, conjugated diene or quinone. Extensive lists of catalyst components and reaction terminators are given and examples describe the copolymerization of ethylene and vinyl chloride in the presence of triethyl borane/oxygen catalysts and termination of the reaction with ammonia. The products may be used in the manufacture of boxes, cartons, bottles and blister packs.