GB639999A - Improvements in or relating to vinyl interpolymers - Google Patents

Abstract

A mixture of 40-95 per cent by weight of vinyl chloride, 2 to 40 per cent of vinylidene chloride, and 2 to 25 per cent of an alkyl ester of acrylic acid is polymerized, the mixture of vinylidene chloride and acrylic ester being added at a substantially uniform rate to an aqueous emulsion of the vinyl chloride during polymerization. Preferably the amount of acrylate exceeds that of vinylidene chloride. Acrylates specified are methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, n-amyl, 2-ethylhexyl, lauryl, n-octadecyl esters. Actinic radiation, as well as hydrogen, benzoyl or caprylyl peroxides, potassium persulphate or sodium perborate may be used. Buffers such as sodium bicarbonate, sodium acid phosphate, lead acetate or ammonium hydroxide may be present. The reaction may be carried out at a temperature ranging from room temperature to 100 DEG C. and higher, in a stainless steel container, and in the absence of air. Soaps such as sodium oleate, potassium palmitate, or sodium myristate, rosin or dehydrogenated rosin soaps, hymolal sulphates, sodium lauryl sulphates, sodium isopropyl naphthalene sulphonate and the sodium salt of N-octadecyl-N-(1,2-dicarboethyl) sulphosuccinamide may be used as emulsifiers. Plasticizers, pigments and stabilizers may be added during or after copolymerization. The products may be made into films and sheets, or used as a latex, or to make corrosion resistant pipes, gramophone records and extruded goods. The Specification as open to inspection under Sect. 91 comprises also polymerization in bulk and in solvents, with or without the gradual addition of monomers during the process. This subject-matter does not appear in the Specification as accepted.