Verfahren zur Herstellung von Polymerisaten des Vinylchlorids

摘要

Thermoplastic moulding materials are made by graft polymerizing vinyl chloride by means of free radicals on to a copolymer of ethylene and a vinyl ester which contains a C1-C5 alkyl or an aryl radical in the ester grouping. The polymerization may be carried out in bulk, in solution in an organic solvent, in a latex of the ethylene-vinyl ester copolymer or, preferably, by dissolving the ethylene-vinyl ester copolymer in vinyl chloride and polymerizing the mixture in suspension in water. Free radicals are supplied by organic peroxides or azodiisobutyronitrile. Preferred graft polymers are made by polymerizing 85 to 96 parts by weight of vinyl chloride with 4 to 15 parts by weight of an ethylene-vinyl acetate copolymer which contains 20-80% by weight of vinyl acetate.