Improved polyvinyl chloride compositions

Polyvinyl chloride compositions resistant to discoloration by copper are plasticized with a mixture of a polyester prepared from a glycol, a dibasic acid and at least 5 weight per cent of one or more C10-20 monobasic fatty acids with a minor proportion of an epoxide. The P.V.C. may be a homopolymer of vinyl chloride or a copolymer thereof with other olefinic monomers, e.g. those containing vinyl or acrylic groups. The epoxide may be any epoxidized organic compound. Specified epoxides are epoxidized semi-drying and drying oils, e.g. soya bean or linseed oils; epoxidized polyesters, e.g. those obtained by treating polyesters obtained by condensing diols with dicarboxylic acids and unsaturated monobasic fatty acids with peracids as described in Specification 744,831; epoxidized esters of monohydric alcohols and unsaturated acids obtained by hydrolysis of animal or vegetable fats or oils, e.g. hexyl oleate and esters of 2-ethylhexanol and soybean fatty acids or butanol and linseed oil fatty acids; phenyl glycidyl ether; and p,p1-diphenylolpropane diglycidyl ether. The amount of epoxide should be sufficient to provide at least 0.1%, preferably 0.18 to 0.6% by weight of epoxide in the total composition. An exemplary composition comprises, by weight:-100 parts P.V.C.; 50 parts of a polyester derived from propylene glycol, adipic acid and coconut oil fatty acids; 5 parts of soya bean oil epoxidized with hydrogen peroxide and formic acid and 10 parts of white lead paste.