Patent ID: 7632915

Claim:
A process for producing a poly(arylene sulfide), which comprises the respective steps of: (1) a polymerization step of heating and polymerizing at least one sulfur source selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides and a dihalo-aromatic compound in an organic amide solvent (A) after an alkali metal hydroxide is added as needed, (2) a separation step comprising sifting a reaction mixture containing formed polymer through a screen to separate the polymer from the reaction mixture after the polymerization step, (3) a washing step comprising bringing the separated polymer into contact with an organic solvent (B) comprising a ketone or alcohol to wash the polymer, (4) a purification step of separating the polymer from a liquid component (C) containing the organic solvent (B) used in the washing step by sifting the polymer and wash medium through a screen after the washing step, recovering the organic solvent (B) from the liquid component (C) by distillation, and thereafter purifying the recovered organic solvent (B) by i) adding an inorganic acid to the recovered organic solvent (B) and then conducting distillation again, or ii) bringing the recovered organic solvent (B) into contact with activated carbon and then conducting distillation again, to lower the content of methylamine mixed therein to be at most 3,000 ppm by weight, and (5) a step of recycling the purified organic solvent (B) to the washing step of the poly(arylene sulfide).