Abstract: There is disclosed a polyphenylene sulfide resin composition which comprises: (a) 100 parts by weight of a polyphenylene sulfide resin; and (b) from about 0.1 to about 10 parts by weight of finely divided calcium carbonate having a mean particle size of less than about 0.5 .mu.m and a BET surface area of greater than about 15 m.sup.2 /g. The resin composition is improved in that it exhibits no or little corrosive action on metals and that it shows excellent mechanical strength.

Abstract: In a process for producing poly (p-phenylenesulfide) from an alkali metal sulfide and a p-dihalobenzene, a product polymer of an advantageously increased molecular weight is obtained by: providing a mixture comprising an alkali metal sulfide, a polar aprotic solvent, a sodium salt of an aliphatic carboxylic acid represented by the general formula: RCOONa (where R is an aliphatic hydrocarbon group having 1-20 carbon atoms), the content of water present in said mixture apart from any water of hydration or crystallization which may be contained in said sulfide and sodium salt being in the range of 5 to 20 moles per mole of said sulfide; thermally dehydrating said sulfide component in said mixture by removing at least part of the water from said mixture; and then contacting the resulting dehydrated mixture with a p-dihalobenzene.

Abstract: A process for producing a polyphenylene sulfide ketone polymer comprising reacting a dihalogen compound of the general formula ##STR1## wherein X and X', which may be the same or different, each represents a fluorine, chlorine, bromine or iodine atom, with an alkali metal sulfide in a polar solvent in such a way that the alkali metal sulfide is not deprived of free water or the water of hydration in the polar solvent before polymerization is started, and that the reaction is performed at a temperature in the range of from 80.degree. to 170.degree. C. in the initial period of polymerization until the percentage of residual unreacted dihalogen compound is reduced to 2% or below, with the subsequent reaction being performed at a temperature in the range of from 200.degree. to 345.degree. C.

Abstract: An improved process for producing poly(arylene sulfide sulfone) of increased molecular weight is provided. The process employs an Li salt of C.sub.1 -C.sub.20 carboxylic acid as a polymerization auxiliary and is carried out in an organic amide solvent by reacting a dihalogenated aromatic sulfone with an alkali metal sulfide in the presence of 10-15 moles of water per mole of the alkali metal sulfide at temperatures within the range of from 160.degree. C. to 230.degree. C.

Abstract: In a process for producing poly (p-phenylenesulfide) from an alkali metal sulfide and a p-dihalobenzene, a product polymer of an advantageously increased molecular weight is obtained by: providing a mixture comprising an alkali metal sulfide, a polar aprotic solvent and a carboxylic acid sodium salt represented by the general formula: ZCOONa (wherein Z is a C.sub.6 -C.sub.20 aromatic hydrocarbon group or a substituted or unsubstituted pyridyl group ##STR1## where substituents R, which may be the same or different, represent each a C.sub.1 -C.sub.

Abstract: An improved process for preparing poly(phenylene sulfide) is provided. In the process, an additional amount of solvent is introduced into the reaction mixture, when a conversion of at least 80% of dihalobenzene, one of the reactants, has been achieved. By the measure, heavy scaling which has been experienced with the conventional processes is effectively inhibited.

Abstract: A class of amide group-containing aromatic dihalide compounds are sulfidized to provide a novel class of aromatic sulfideamide polymers increased in crystalline melting point (T.sub.m). The polymers exhibit excellent resistance to high temperatures, resistance to solvents, flame-retardant properties and improved mechanical properties.

Abstract: A class of amide group-containing aromatic dihalide compounds are sulfidized together with a class of aromatic dihalide compounds to provide a novel class of aromatic sulfideamide polymers increased in crystalline melting point (T.sub.m). The polymers exhibit excellent resistance to high temperatures, resistance to solvents, flame-retardant properties and improved mechanical properties.

Abstract: A method for purifying N-methyl-2-pyrrolidone containing thiophenol and/or diphenyl disulfide is disclosed, comprising adding a polyhalogenated aromatic compound and an alkali metal hydroxide and/or an alkali metal carbonate to the N-methyl-2-pyrrolidone containing thiophenol and/or diphenyl disulfide, heat treating the mixture, and subjecting the mixture to separation by distillation. The thiophenol and/or diphenyl disulfide can be removed with ease and at low cost.

Abstract: A polyphenylene sulfide composition useful for plating is disclosed, comprising a polyphenylene sulfide resin, glass fibers, and potassium titanate fibers. Molded articles of this composition, when plated after etching, provide a plated article which is excellent in appearance and peel strength. Thus these plated articles can be used in outer applications, such as electric parts and automobile parts.