Polymerisation process

摘要

Vinylidene chloride is polymerized alone or with up to 50% by weight of the mixture of monomers of other copolymerizable monomers in aqueous medium in the presence of a free radical polymerization catalyst and, as surface active agent, at least 0.05% by weight of the polymerizable material of at least one cationic ammonium compound of formula where R is an aliphatic hydrocarbon radical having 8 to 24 carbon atoms, R1 is hydrogen or an alkyl group, B, D and E are straight chain alkylene groups containing at least two carbon atoms, m is a positive integer, n is 0 or 1, x, y and z are 0 or positive integers and the sum of x, y and z is at least n+2, A is an anion and q is the valence of A. The surface active agents may be the acid or ester adducts of polyethoxylated or polypropoxylated lauryl, myristyl, oleyl, stearyl or linoleyl amines or mixtures such as coco amines, tallow amines or soya amines, or the corresponding amino amines. Specified copolymerizable monomers are acrylonitrile, methacrylonitrile, methyl methacrylate, vinyl chloride, dimethyl fumarate, dimethyl maleate, methyl acrylate, ethyl acrylate, acrylic acid, maleic acid, itacanic acid and dicarboxylic acid half esters. Examples describe the copolymerization of vinylidene chloride and acrylonitrile in aqueous media in the presence of hydrogen peroxide and ferrous sulphate and surface active agents obtained by ethoxylating (1) and (2) tallow amines, (3) coco amines and (4) stearylamine and neutralizing the products with hydrochloric acid; and (5) the reaction product of tallow with propylenediamine and neutralizing the product with hydrochloric acid. The stability of the latices may be improved by adding further quantities of the same or different cationic quaternary ammonium surface active agents. The polymers may be used to give antistatic coatings, e.g. on polypropylene or polyethylene terephthalate films, by coating from latices or organic solvent solutions, or may be moulded to form antistatic articles.ALSO:Films of thermoplastic materials, e.g. polypropylene and polyethylene terephthalate, are coated with latices prepared by polymerizing vinylidene chloride, alone or with up to 50 weight per cent of other copolymerizable monomers, in aqueous medium in the presence of, as surface active agent, at least 0,05% by weight of the polymerizable material of at least one cationic ammonium compound of formula: where R is an aliphatic hydrocarbon radical containing 8-24 carbon atoms, R1 is hydrogen or an alkyl group, B, D and E are straight chain alkylene groups containing at least two carbon atoms, m is a positive integer, n is 0 or 1, x, y and z are 0 or positive integers and the sum of x, y and z is at least n+2, A is an anion and q is the valence of A. Specified comonomers are acrylonitrile, methacrylonitrile, methyl methacrylate, vinyl chloride, dimethyl fumarate, dimethyl maleate, methyl acrylate, ethyl acrylate, acrylic acid, maleic acid, itaconic acid and dicarboxylic acid half esters. The ammonium compounds may be polyethoxylated or polypropoxylated lauryl, myristyl, oleyl, stearyl or linoleyl amines or mixtures such as coco amines, tallow amines or soya amines, or the corresponding amino amines. In examples vapour barrier, antistatic and heat sealing properties are imparted to polyethylene terephthalate films by coating with latices of vinylidene chloride/acrylonitrile copolymers prepared in the presence of ethoxylated (1 and 2) tallow amines, (3) coco amines, (4) n-stearylamine, and (5) the reaction product of tallow with propylene diamine; and to (6 to 10) polypropylene film by coating with similar latices.