| abstract |
Disclosed is a process for the preparation of polyphenylene-sulfide resins, wherein an aromatic polyhalide compound is reacted with an alkali metal sulfide, or hydrogen sulfide and an alkali metal base, or an alkali metal hydrosulfide and an alkali metal base in the presence of an amide polar solvent. A polyphenylene-sulfide resin having a cyclic oligomer content lower than l.5% by weight, as determined according to the methylene chloride extraction method, is obtained by (a) carrying out the reaction in the absence of a polymerization aid, (b) using the amide polar solvent in an amount not larger than 400 g per mole of the aromatic polyhalide compound, and (c) subjecting the polymerization liquid obtained by the reaction to hot solid-liquid separation at a temperature of at least 50°C but below the boiling point of the solvent used, and washing the separated solid with the solvent used for the reaction, which is heated at a temperature of at least 50°C but below its boiling point. |