Abstract: High-quality polyarylene-thioether fibers are provided, which simultaneously satisfy the following conditions:(a) the polyarylene-thioether is a linear polyarylene-thioether having a melt viscosity of 5,300 to 20,000 poise (at 310.degree. C. and a shear velocity of 200 second.sup.-1);(b) the fiber diameter is in the range of 1 to 50 microns;(c) the tensile strength is not less than 40 kg/sq.mm;(d) the tensile modulus of elasticity is not less than 500 kg/sq.mm; and(e) the tensile strength at 200.degree. C. is not less than 20 kg/sq.mm.The fibers are produced by continuously melt-spinning a linear polyarylene-thioether polymer having a melt viscosity of 5,300 to 20,000 poise (at 310.degree. C. and a shear velocity of 200 second.sup.-1), continuously stretching the spun filament, and continuously heat-setting the stretched filament for 0.02 to 100 seconds at a temperature of not lower than the melting point of the polymer minus 100.degree. C.

Abstract: Disclosed herein is a novel process for producing a substantially linear PAS which contains an electrolytic alkali metal of not more than 50 ppm, shows a melt viscosity of 10 to 300 poise (measured at 310.degree. C. and at a shear rate of 10,000 sec.sup.-1) and is suitable as a resin for packaging electronic parts.

Abstract: Disclosed herein is a process for producing a medium- or high-molecular-weight polyarylene sulfide which comprises subjecting an alkali metal sulfide, a dihalo aromatic compound and optionally, small amount of tri- or higher polyhalo aromatic compound to dehalogenation and sulfidation reaction at a temperature of from 235.degree. to 280.degree. C. in the presence of a water in amount of from 0.5 to 5 mol per 1 kg of an aprotic organic polar solvent until the conversion of said dihalo aromatic compound reaches from 70 to 98 mol %, thereby forming a polyarylene sulfide prepolymer having a melt viscosity of from 5 to 300 poise (as measured at 310.degree. C. under a shear rate of 200 sec.sup.-1), adding water to the resultant reaction mixture containing the polyarylene sulfide prepolymer so that from 6 to 15 mol of water is present per 1 kg of said solvent, and then continuing the reaction at a temperature of from 240.degree.-290.degree. C.

Abstract: A polyarylenethioether primary melt formed article having a Hunter whiteness higher than 30% and a parallel light transmittance Tp higher than 60%, as measured for a sheet with a thickness of 0.3 mm, at the process for obtaining the article which comprises producing a polyarylenethioether according to the polymerization reaction comprising a dehalogenation/sulfidization reaction between an alkali metal sulfide and a dihaloaromatic compound in a polar organic solvent by carrying out the reaction with the addition of an effective amount of a halo-substituted organic compound to obtain a stabilized polyarylenethioether, and then subjecting the polyarylenethioether to melt extrusion. The melt formed article thus produced can be subjected to further melt processing to produce a secondary melt formed article or structure of polyarylenethioether.

Abstract: A para-phenylene sulfide block copolymer consisting essentially of a recurring unit (A) ##STR1## and a recurring unit (B) ##STR2## said recurring units (A) being present in the form of a block of 20 to 5,000 units of (A) on the average in the molecular chain, the mol fraction of the recurring units (A) being in the range of 0.50 to 0.98, the block copolymer having a melt viscosity (.eta.*) of 50 to 100,000 poise as determined at 310.degree. C. at a shear rate of 200 sec.sup.-1 and having: (a) a glass transition temperature (Tg) of 20.degree. to 80.degree. C., (b) a crystalline melting point (Tm) of 250.degree. to 285.degree. C.

Abstract: Disclosed herein are a process for producing a high-molecular-weight or ultra-high-molecular-weight granular PAS of an excellent handling property at an inexpensive cost without using a polymerization aid such as an organic acid salt, and a high-molecular-weight or ultra-high-molecular weight granular PAS of an excellent handling property produced by the process thereof.

Abstract: A para-phenylene sulfide block copolymer consisting essentially of a recurring unit (A) ##STR1## and a recurring unit (B) ##STR2## said recurring units (A) being present in the form of a block of 20 to 5,000 units of (A) on the average in the molecular chain, the mol fraction of the recurring units (A) being in the range of 0.50 to 0.98, the block copolymer having a melt viscosity (.eta.*) of 50 to 100,000 poise as determined at 310.degree. C. at a shear rate of 200 sec.sup.-1 and having: (a) a glass transition temperature (Tg) of 20.degree. to 80.degree. C., (b) a crystalline melting point (Tm) of 250.degree. to 285.degree. C.

Abstract: Disclosed herein is a biaxially oriented paraphenylene sulfide block copolymer film showing a heat shrinkage of 0-2.0% at 100.degree.-220.degree. C., comprising a paraphenylene sulfide block copolymer essentially composed of recurring units (A): ##STR1## and recurring units (B): ##STR2## the molar fraction of recurring units (A) being 0.50-0.98, and having a melt viscosity (.eta.*) of 1,000-15,000 poises as measured at 310.degree. C. and shear rate of 200 sec.sup.-1, a glass transition temperature (Tg) of 20.degree.-80.degree. C., a crystalline melting point (Tm) of 250.degree.-285.degree. C. and a crystallization index (Ci) of 15-45 (measured with the non-stretched heat-treated polymer film), and a process for producing the biaxially oriented paraphenylene sulfide block copolymer film.

Abstract: Disclosed herein is a process for producing a biaxially oriented paraphenylene sulfide block copolymer film, comprising melt extruding and molding a paraphenylene sulfide block copolymer essentially composed of recurring units (A): ##STR1## and recurring units (B): ##STR2## the molar fraction of recurring units (A) being 0.50-0.98, and having a melt viscosity (.eta.*) of 1,000-50,000 poises as measured at 310.degree. C. and shear rate of 200 sec.sup.-1, into a film, and after cooling, biaxially stretching the thus molded film at a stretching temperature (T) defined by the following formula:96-50X<T<116-66.7Xwherein T is a stretching temperature (.degree.C.

Abstract: Polyarylene thioethers having increased melt crystallization temperature are produced by subjecting a polyarylene thioether recovered from a conventional polycondensation of dichlorobenzene with sodium sulfide to a treatment with an aqueous non-oxidative strong acid such asd HCl, H.sub.2 SO.sub.4 or H.sub.3 PO.sub.4 or with an aqueous salt of the non-oxidative strong acid with a weak base such as ammonia.

Abstract: In a process for producing a polyarylene thioether having high stability by dehalogenation/sulfurization reaction of an alkali metal (M) sulfide such as sodium sulfide and a dihaloaromatic compound such as paradichlorobenzene in a polar organic solvent, the haloaromatic compound is used excessively in an appropriate range rather than the alkali metal sulfide and the latter stage of the reaction or all period of the reaction is conducted under a powerful stirring condition to a certain degree to obtain the polyarylene thioether wherein the concentration of --SM or --SH groups of the polymer terminal is lowered. The polyarylene thioether thus obtained suppresses the coloration in the processing with an apparatus made of ferrous material such as extruder.

Abstract: A process for the preparation of a high-molecular-weight polyarylene sulfide, which comprises subjecting an alkali metal sulfide such as sodium sulfide and a dihalo aromatic compound such as dichlorobenzene to dehalogenation sulfidation reaction in an organic amide solvent, wherein at least a part of the reaction is carried out in a reaction vessel in which at least the portion which the reaction liquid contacts is made of titanium, through at least the following two steps: (1) the step of carrying out the reaction at a temperature of 180.degree. to 235.degree. C. in the presence of water in an amount of 2.4 to 10 moles per mole of the alkali metal sulfide so that the conversion of the dihalo aromatic compound is at least 50% and the melt viscosity of the formed polyarylene sulfide does not exceed 500 P, and (2) the step of elevating the temperature to 245.degree. to 290.degree. C. in the presence of water in an amount of 2.

Abstract: A novel phenylenesulfide resin composition comprises(I) a poly-p-phenylenesulfide,(II) a poly-m-phenylenesulfide, and(III) a phenylenesulfide block copolymer consisting essentially of a repeating unit ##STR1## (A) and a repeating unit ##STR2## (B), wherein from 20 to 5,000 units on the average of the repeating units (A) linked together exist in the molecular chain in the form of the block component, and wherein the molar faction (X) of the repeating unit (A) is in the range of 0.10 to 0.95, the mixing ratio of the three components (I), (II) and (III) being in a specified range. The composition is characterized by compatibility between the components (I) and (II), whereby transparency, physical properties and other characteristics thereof are markedly enhanced.

Abstract: By maintaining an arylenesulfide prepolymer with a melt viscosity of 5 to 3,000 poise at a temperature of 245.degree. to 290.degree. C. under a liquid-liquid two-phase separated state in a solvent for 1 to 50 hours, the molecular weight of said prepolymer is increased to a high to ultra-high value while the linearity of the polymer is retained.

Abstract: The improvement in a process for producing an aromatic sulfide polymer from (A) hydrous sulfide of an alkali or alkaline earth metal and (B) a dihalo-aromatic compound is disclosed. The improvement is concerned with how the hydrous sulfide is dehydrated and comprises dehydrating the hydrous sulfide by the action thereon of (C) an alkaline earth metal oxide before substantial formation of the aromatic sulfide polymer.

Abstract: A process for obtaining an aromatic sulfide polymer which has a markedly high molecular weight and can be readily formed into films, fibers, and other structures. The process comprises heating, to a temperature of 100.degree. to 270.degree. C. in an organic solvent under the coexistence of a very small amount of water, a dihaloaromatic compound and a substantially anhydrous amorphous vitreous compound composed of (i) S.sup.2- anions and other inorganic salt-forming anions and (ii) ions of an alkali metal and/or an alkaline earth metal.

Abstract: A process for obtaining aromatic sulfide polymer which has a markedly high molecular weight and can be readily formed into films, fibers, and other structures. The process comprises heating, in an aprotic solvent to a temperature of 100.degree. to 250.degree. C., (i) a dihaloaromatic compound and (ii) substantially anhydrous fine powder of the sulfide of an alkali or alkaline earth metal in the presence of (iii) substantially anhydrous fine powder of the carbonate of an alkali or alkaline earth metal, or of a mixture thereof with a hygroscopic inorganic salt and (iv) a strictly controlled very small amount of water dissolved in or solvated with the solvent.

Abstract: A monomer mixture comprising .alpha.-methylstyrene or 2-isopropenylnaphthalene, methyl methacrylate, and acrylonitrile is polymerized in the presence of a crosslinked polymer obtained by copolymerizing a monofunctional monomer such as .alpha.-methylstyrene with a small quantity of a polyfunctional monomer such as divinylbenzene to obtain a copolymer (C). A vinyl chloride resin composition formulated by blending the copolymer (C) thus obtained with a vinyl chloride resin and an impact strength modifier resin in a specific proportion possesses improved thermal deformation resistance and impact strength while retaining processability comparable to that of the vinyl chloride resin mixed with the impact strength modifier resin.

Abstract: A vinyl chloride resin composition comprises:(1) 100 parts of vinyl chloride polymer; and(2) 0.1 to 30 parts of a polymer processing aid comprising:(A) 40 to 90 parts of a copolymer comprising80 to 100% of an alkyl methacrylate, and0 to 20% of a monomer copolymerizable therewith; and(B) 60 to 10 parts of a copolymer comprising20 to 79% of an alkyl methacrylate,20 to 79% of an aromatic vinyl monomer,1 to 49% of diolefin, and0 to 20% of a monomer copolymerizable therewith,the copolymers (A) and (B) having been wet-blended to provide 100 parts of the polymer processing aid, all quantities expressed in parts and percentages being by weight.

Abstract: A composition comprising polyvinyl chloride and a novel polymer processing aid is provided. The polymer processing aid can be obtained either by blending in latex form an alkyl methacrylate copolymer (A) and a copolymer (B) comprising as its essential constituents an alkyl methacrylate, a dialkyl itaconate or an alkyl acrylate, and a diolefin, or by copolymerizing one of the copolymers in the presence of the other copolymer.The polymer processing aid thus obtained improves the processability of the vinyl chloride resin composition with less reduction in impact strength.