GB569927A - Interpolymers of ethylene and vinyl organic esters - Google Patents

Abstract

Improved interpolymers of ethylene and vinyl organic esters are made by heating at super-atmospheric pressure in the presence of a peroxy compound and a non-polymerizable liquid, a mixture having proportions such that the interpolymer contains less than 6 and more than 0.25 mol. per cent of vinyl organic ester. Esters specified are vinyl acetate, diethyl acetate, thiol acetate, trimethyl-acetate, propionate, n-butyrate, isobutyrate, isocaproate, tert-butyl and tert-amyl acetates, benzoate, stearate, laurate, undecylenate, hexanoate, oleate, toluate, hexahydrobenzoate, phenylacetate, furoate, picolinate, and 2,4-diethyl- or dimethyl-pentanoate, methyl vinyl and ethyl vinyl adipates, methyl vinyl succinate and the vinyl ester of thiophene-1-carboxylic acid. Suitable peroxy compounds are benzoyl, acetyl, butyryl, acetyl benzoyl, lauroyl, diethyl, tetralin, and urea peroxides, persuccinic and peracetic acids or alkali metal and ammonium persulphates, perborates, and percarbonates. The menstruum may be water, iso-octane, toluene, butyl acetate, diethyl ether, n-hexane, cyclohexane, 1,4 - dioxane, m - bromotoluene, petroleum ether or petroleum spirit or mixtures. Suitable dispersing agents are starch, water-soluble salts of alkyl sulphates, e.g. the sodium salt of sulphated octadecenyl acetate or alkane sulphonates and alkali metal salts of sulphonated mineral oils. Buffering agents, e.g. potassium dihydrogen phosphate, sodium acetate, sodium carbonate and sodium tetraborate may be present. The reaction vessel is preferably made of or lined with stainless steel, silver, aluminium, tin, lead, enamel or glass. The reactants are preferably agitated during polymerization, e.g. by rapid stirring, shaking, atomization, bubbling gas through the liquid or by turbulence in a continuous flow process. The products may be formed into tough, tear-resistant films which may be cold-drawn. Specification 497,643 is referred to.