GB1012232A - Polythiocarbonates and their preparation - Google Patents

Abstract

High molecular weight polythiocarbonates are made by reacting one or more alkali metal bisphenates with thiophosgene in the presence of a quarternary ammonium compound or a tertiary sulphonium compound as a catalyst. Preferably the reaction is effected with the bisphenate in aqueous solution or suspension and the thiophosgene dissolved in an organic solvent which is preferably a solvent or swelling agent for the polythiocarbonate (e.g. a halogenated hydrocarbon or an aromatic hydrocarbon). The bisphenol is preferably of formula <FORM:1012232/C3/1> where X is an alkylene or alkylidene group or two or more such groups bound together by an arylene, -S-, -SO- or -SO2- group or X represents a cycloaliphatic group, -S-, -SO-, -SO2-, -O-, -CO- or a tertiary amino radical; R1 is an alkyl, aryl, aralkyl, alkaryl or cycloaliphatic group or any of these groups substituted by alkyl or halogen; Y is a halogen atom, an alkyl group or a haloalkyl group; n is 0 or a whole number; and m is 0 or a whole number. The reaction mixture may also include (a) a dihydric phenol of formula <FORM:1012232/C3/2> where Ar is an arylene group (e.g. phenylene, bisphenylene or naphthylene) and Y1 and n1 are the same as Y and n; (b) a diacid chloride of a dicarboxylic acid (e.g. terephthalic, isophthalic, sebacic or adipic acid or bis-(4-carboxyphenyl) ether); (c) a bischloroformate of a dihydric compound (e.g. bisphenol A or ethylene glycol) or (d) phosgene. Some of the polymers are soluble in chlorinated hydrocarbons, aromatic hydrocarbons and cyclic ethers. They are useful in the manufacture of films. Examples describe the reaction of thiophosgene, bisphenol A and, possibly, isophthaloyl chloride.