GB1116990A - Improvements in the production of olefin copolymers - Google Patents

Abstract

Copolymers are prepared by copolymerizing (a) an olefin monomer and a vinyl monomer (i.e. a compound containing a substituted or unsubstituted CH2 = CH- group) to form a binary copolymer wherein the units derived from the olefin and vinyl monomers are in a weight ratio of 9-90:91-10, or (b) acrylonitrile, isobutylene and a said vinyl monomer to form a ternary copolymer wherein the respective monomer units are in a weight ratio of 50-70:10-30:5-35; the reaction vessel and all liquid reaction components being deoxygenated before the reaction to contain less than 1 p.p.m. by weight of free oxygen, and the reaction being conducted in aqueous emulsion in the presence of a polymerization catalyst and under autogenous pressure at a temperature of 25-75 DEG C. Suitable olefins include isobutylene, 3,3-dimethylbutene-1, 2-methyl-pentene-1 and hexene-1. Vinyl monomers specified are acrylonitrile, methacrylonitrile, alkyl acrylates, methacrylates, maleates and fumarates having up to 8 carbon atoms in the alkyl groups which may possibly be substituted (e.g. 2-cyanoethyl acrylate), vinyl acetate, vinyl chloride, vinylidene chloride, styrene and its derivatives (e.g. p-chloro-styrene), and methyl vinyl ketone. Polymerization can be intiated with catalysts such as organic peroxides and hydroperoxides and systems such as potassium persulphate/sodium bisulphite and hydrogen peroxide/Fe3+. The reaction includes an emulsifier, e.g. sodium lauryl sulphate, sodium alkylbenzene sulphonates, sodium sulphonates of the formula <FORM:1116990/C3/1> and alkylphenol polyethyleneglycol ethers. The polymer can be obtained in the form of a fine white granular powder. In examples, the polymerization is effected at a pH of 2-5. The polymers, with or without additives, can be formed into coatings, films, moulded articles, fibres and sheets; also, the polymer emulsions can be used directly for impregnating or coating textiles or paper.