Verfahren zum Polymerisieren von Vinyl- und Vinylidenchlorid

Polymers and copolymers of vinyl chloride and vinylidene chloride are made by polymerizing the monomer or monomers, in aqueous dispersion, in the presence, as a dispersing agent, of up to 5 per cent of a partial ester of a polyhydric alcohol having a maximum of 10 hydroxy groups in the molecule with a fatty acid having at least 4 carbon atoms in the molecule, separating the polymeric material and drying without any intermediate washing step. The partial ester may be condensed with ethylene oxide. Comonomers specified are acrylonitrile, methacrylonitrile, crotonitrile, methyl and ethyl vinyl ketones, cyclohexyl methacrylate, methyl methacrylate, butyl acrylate, dicyclohexyl maleate, butyl itaconate, cyclohexyl itaconate, diethyl itaconate, dibutyl fumarate, vinyl fluoride, vinyl acetate, vinyl methoxybutyrate and vinyl benzoate. The specified partial esters are glyceryl monocaprate, -stearate, -laurate, -oleate, -heptoate; diethylene glycol mono-oleate; pentaerythritol mono- or di-caprate or laurate; sorbitan monolaurate, sorbitan trioleate and sorbitan mono - stearate polyoxyalkalene derivatives. The polymerization is preferably effected in the presence of a peroxide polymerization catalyst such as orthochlorbenzoyl, caprylyl or benzoyl peroxide, or potassium persulphate. The polymerization mixture may also contain methanol, ethanol, n-butanol, lauryl alcohol, monacetin, glycerol, sodium bicarbonate, sodium hypochlorite or triethanolamine stearate. Plasticizers such as dimethylbenzylether and alpha, alpha1-diphenyl diethyl ether may be incorporated into the polymers and the compositions extruded. Specification 622,481 (as open to inspection under Sect. 91) is referred to.ALSO:Esters of polyhydric alcohols suitable for use as dispersing agents in polymerization reactions are pentaerythritol dicaprate, dilaurate and monolaurate, and the condensation product of ethylene oxide with glycerol monostearate, mono-oleate, monolaurate and diethyleneglycol mono-oleate. Pentaerythritol dicaprate and dilaurate are made by direct esterification under 15 mms. pressure followed by extraction with carbon tetrachloride. Pentaerythritol monolaurate is made by esterification of the theoretical amounts of acid and alcohol in phenol as the solvent and paratoluenesulphonic acid as catalyst. The ethylene oxide condensation products are made by heating the partial ester, ethylene oxide and sodium methoxide in a closed stainless steel tube, to give products which are water-soluble