Thermoplastic linear polysulfonates from di (hydroxyphenyl) valeric acid

New polysulphonates, having carboxyl groups or alkali metal carboxylate groups in side chains, are made by condensing a metal salt of 4,4-di-(4-hydroxyphenyl) -nvaleric acid of formula dissolved in aqueous media with a diacid halide of an aromatic disulphonic acid which is dissolved or dispersed in a water-immiscible organic liquid (e.g. a chlorinated aliphatic hydrocarbon and/or a benzene or toluene). The disulphonyl halide used preferably has the formula wherein Hal is chlorine or bromine; Ar is an aromatic group; X is an alkylene group, alkylidene group, sulphur-containing radical (e.g. -S-, -SO- or -SO2-), ether radical, carbonyl or tertiary amino radical, or may be two or more alkylene or alkylidene groups which are bound together by an aromatic radical, a tertiary amino radical, an ether radical or by a sulphur-containing radical; R is an alkyl, aryl, aralkyl, alkyl-substituted aryl or cycloaliphatic group (any of which may be halogen substituted); Y is a halogen atom, a nitro group or an OR1 or R1 radical wherein R1 is as defined for R; n is O or an integer; m is O or an integer; p is an integer; q is O or 1; and r is an integer or may be O if q also is O. Catalysts for the reaction are tertiary sulphonium compounds and quaternary ammonium, phosphonium and carbonium compounds. At the end of the condensation, the polysulphonate may be precipitated from its solution in the aqueous layer with hydrochloric acid. The salt forms of the polysulphonates are soluble in water and aqueous alkaline medium (e.g. in photographic developing baths) and the acid forms are soluble in ethanol, acetone, dioxane, methylene chloride, tetrachlorofurane, dimethyl formamide and tetrahydrofurane and in mixtures of ethylacetate and tetrahydrofurane, alcohol and dioxane, ethyl acetate and isopropanol, and alcohol together with ethyl acetate and isopropanol. The polysulphonates are useful in the manufacture of film and fibres; binding agents in photographic anti-halotion layers, antistatic layers and protective layers; and as sizing agents and antistatic agents. In examples, in which reaction is effected in the presence of methylene chloride, aqueous sodium carbonate or sodium hydroxide solution and triethylbenzyl ammonium chloride, polysulphonates are obtained by reacting together 4,4-di-(4-hydroxyphenyl) -nvaleric acid and (1) 1,3-dichlorosulphonyl benzene; (2) 1,3-dimethyl-4, 6-di-chlorosulphonyl benzene; (3) 1,3-dichlorosulphonyl benz