GB728557A - Improvements in trifluorochloroethylene copolymer - Google Patents

Abstract

Copolymers are prepared by copolymerizing a mixture comprising 75 to 95 per cent of trifluorochlorethylene and from 5 to 25 per cent of vinyl chloride. A portion of the vinyl chloride may be withheld at the beginning of the copolymerization and added at a later stage. Copolymerization is preferably carried out in aqueous emulsion in the presence of a catalyst such as hydrogen peroxide, potassium, sodium, or ammonium persulphate or perborate, acetyl peroxide, peracetic acid and perbenzoic acid, which may be used in the presence of a versivalent metal and a reducing agent. Emulsifying agents which may be used include sodium oleate, potassium stearate, the sodium salts of rosin acids, sodium alkyl sulphates and sulphonates containing from 8 to 22 carbon atoms, the sodium sulphonates of aromatic and alkylated aromatic compounds containing from 8 to 22 carbon atoms, di-(2-ethyl hexyl) sulphosuccinate, sulphated partial fatty glycerides and hexitan stearate. Copolymerization may also be effected in bulk or in solution in an inert solvent, preferably a fluorohydrocarbon or fluorochlorohydrocarbon. The copolymers of the invention are soluble in cyclohexanone, toluene, butyl acetate, chloroform and ethylene dichloride, and the solutions may be used for casting films or forming coatings. The copolymers may be plasticized with chlorinated biphenyl, acetylated methyl ricinoleate, or di-(3,5,5-trimethyl hexyl) diglycolate, and may be used to produce chemical resistant articles such as piping, aprons, equipment lining, gaskets, buckets, ladles, dippers, funnels, flasks, impellers and baffles.