GB1235186A - Process for the manufacture of ethylene copolymer dispersions - Google Patents

Abstract

1,235,186. Ethylene copolymer dispersions. FARBWERKE HOECHST A.G. 7 June, 1968 [7 June, 1967], No. 27319/68. Heading C3P. Aqueous dispersions of ethylene copolymers are prepared by copolymerizing ethylene at 50 to 2500 atmospheres and 50‹ to 250‹ C. in an aqueous medium in the absence of an emulsifier and in the presence of a free radical initiator, with 0À1 to 30 weight per cent, calculated on the dispersion solids, of an alkali metal salt of an acylamide N-sulphonic acid of formula R 1 CH=C(R 2 )CONHSO 3 H where R 1 and R 2 are hydrogen or C 1-10 organic-radicals, and optionally less than 50 weight per cent based on the copolymer of one or more further copolymerizable compounds. Preferred salts are dialkali metal, particularly dipotassium, salts of acrylic, α-phenyl acrylic, crotonic and methacrylic amide-N-sulphonic acids. Preferred initiators are azo and peroxy compounds and redox systems. The copolymerization may be effected batchwise or continuously, in a plurality of stages with increasing pressures. Specified comonomers are acrylic compounds, vinyl esters, vinyl and vinylidene halides, butadiene and styrene. The copolymers may be converted to acid form by acidification, and to ethylene/ acylamide copolymers by heating. The copolymers or amide conversion products may be recovered by precipitation and used for moulding. The dispersions are useful for coating, impregnating and finishing. Examples describe the copolymerization of ethylene with (1-3, 5,6 and 8) dipotassium methacrylamide-N- sulphonate, together with (9) methyl methacrylate; and with (4) disodium acrylamide-N- sulphonate and-(7) dipotassium crotylamide-N- sulphonate.