GB694408A - Improvements in or relating to the preparation of vinyl halide copolymers - Google Patents

Abstract

Vinyl halide copolymers are made by heating a vinyl halide in the presence of a peroxy catalyst in a liquid medium in which the vinyl halide homopolymer is relatively insoluble, until there is substantially no monomeric vinyl halide remaining in the reaction mixture, adding a dissimilar polymerizable organic compound and continuing the polymerization. In a modification the polymerization of the vinyl halide is interrupted and substantially all the monomer remaining removed prior to the addition of the dissimilar compound. If desired, the vinyl halide may be copolymerized with another monomer prior to the addition of the dissimilar polymerizable organic compound. The vinyl halide may be vinyl chloride, bromide, iodide or fluoride. Specified dissimilar polymerizable organic compounds are maleic acid, maleic acid esters, tetrahaloethylene, butyl acrylate, methyl methacrylate, allyl acetate and propionate, vinyl acetate and benzoate, styrene, dichlorostyrene, acrylonitrile, methacrylonitrile, vinylidene chloride and bromide, vinyl phenol, acrylic acid, alphabutyl acrylic acid, vinyl methyl ether, allyl chloride, methallyl chloride, allyl methyl ketone, and allyl butyl ketone. The liquid medium may be water, cyclohexane, benzene, toluene, cyclohexanone, heptane and mixtures. When polymerization is effected in water, emulsion or suspension techniques may be employed. Emulsifying agents which may be used are soaps such as sodium, potassium and ammonium myr state, laurate, palmitate, oleate, stearate, rosinate or hydroabietate, the alkali metal alkyl or alkylene sulphates or sulphonates as well as the ammonium salts and amine salts such as laurylamine hydrochloride and stearylamine hydrobromide. Specified peroxy catalysts are benzoyl, acetyl, and di-t-butyl peroxides, persulphuric, peracetic and perphthalic acids, potassium persulphate, t-butyl perbenzoate, cumene hydroperoxide, t-butyl hydroperoxide, monochloro - di - t - butyl peroxide, t - butyl t - amyl peroxide, 2 : 2 - bis - (t - butyl peroxy) butane and t-butyl perpelargonate. The dissimilar polymerizable compound may be added in one lot or intermittently, e.g. at the rate at which it is consumed in the reaction. Monomers which may be added to the vinyl halide prior to the addition of the dissimilar polymerizable organic compound are vinyl acetate, allyl acetate, allyl chloride, methyl acrylate, butyl methacrylate, acrylic acid, methacrylic acid, styrene, methyl styrene, dichlorostyrene, acrylonitrile and methacrylonitrile. The polymers may be made into films for packaging, table tops, toys, buttons or combs or used molten or in solution, as impregnating or laminating agents or surface coatings.