Process for the preparation of polyarylene sulphides

Claim 1

Process for the preparation of high molecular weight branched polyarylene sulphides, characterised in that (a) dihalogenobenzenes, of which 50 to 100 mole % correspond to the formula I ##STR3## and 0 to 50 mole % correspond to the formula II ##STR4## wherein X is fluorine, chlorine, bromine or iodine, and R 1 is identical or different and is hydrogen, C 1 -C 20 -alkyl, C 5 -C 20 -cycloalkyl, C 6 -C 24 -aryl, C 7 -C 24 -alkaryl or C 7 -C 24 -aralkyl, or at least one pair of radicals R 1 can be linked to an aromatic or heterocyclic ring, and always at least one radical R 1 is different from hydrogen, and (b) 0.1 to 2.4 mole %, relative to the dihalogenobenzenes, of a polyhalogenoaromatic of the formula III, ArX.sub.n (III) wherein Ar is a trivalent or tetravalent aromatic or heterocyclic radical having 6-24 C atoms, X has the same meaning as in formula I and II, and n=3 or 4, and (c) an alkali metal sulphide are reacted in (d) a polar solvent, the molar ratio of (a) to (c) being in the range from 0.85:1 to 1.15:1, and (c) to (d) in the range from 1:2 to 1:15, a polycondensation time of up to 10 hours and a polycondensation temperature from 160° to 300° C. being maintained, and the reaction being carried out in the presence of 2 to 30 mole %, relative to alkali metal sulphide, of an alkali metal sulphite and/or alkaline earth metal sulphite.