Abstract: A method for producing a cyclic polyarylene sulfide, wherein a cyclic polyarylene sulfide is produced by heating a reaction mixture which is composed of at least a linear polyarylene sulfide (a), a sulfidizing agent (b), a dihalogenated aromatic compound (c) and an organic polar solvent (d). This method for producing a cyclic polyarylene sulfide is characterized in that not less than 1.25 liters of the organic polar solvent is used per 1 mole of the sulfur content in the reaction mixture. This method enables to efficiently produce a cyclic polyarylene sulfide, more specifically cyclic oligoarylene sulfide by an economical and simple process in short time.

Abstract: The techniques provide a system and a method of producing polyphenylene sulfide (PPS) polymer. The PPS polymer is produced by reacting a sulfur source and a dihaloaromatic compound in the presence of a polar organic compound in a polymerization mixture in a polymerization vessel. The PPS polymer is washed with a base to lower the oligomer content of the PPS polymer and thus the off-gassing during processing.

Abstract: This invention relates to a method of preparing poly(arylene sulfide) (PAS) from an iodo compound and a sulfur compound, and more particularly, to a method of preparing PAS, including adding a sulfur-containing polymerization terminator when PAS is produced using an iodo compound as an intermediate. Thereby, in final PAS, the residual iodine content may be maintained at the same level or decreased and other properties may be maintained at equal or superior levels, thanks to the use of the sulfur-containing polymerization terminator, which is much lower in price than conventional polymerization terminators.

Abstract: In a process for producing a poly(arylene sulfide) by polymerizing a sulfur source and a dihalo-aromatic compound in the presence of an alkali metal hydroxide in an organic amide solvent, the production process comprises washing a polymer obtained by the polymerization with a hydrophilic organic solvent containing water in a proportion of 1 to 30% by weight, thereby collecting a purified polymer, the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer, and a poly(arylene sulfide), the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer.

Abstract: A biaxially oriented polyarylene sulfide film made of a polyarylene sulfide resin composition has a melt crystallization temperature of not lower than 160° C. and not higher than 220° C. The biaxially oriented polyarylene sulfide film contains 70 to 99 parts by weight of the polyarylene sulfide and 1 to 30 parts by weight of thermoplastic resin A; the thermoplastic resin A constitutes a dispersed phase having an average dispersion diameter of 50 nm to 500 nm. The biaxially oriented polyarylene sulfide film has a breaking stress at 200° C. in the machine direction and/or transverse direction of not less than 30 MPa and not more than 90 MPa and has an elongation at break at 200° C. in the machine direction and/or transverse direction of not less than 100% and not more than 250%.

Abstract: A poly(arylene sulfide) having properties that a melt viscosity is 1 to 3,000 Pa·s as measured under conditions of a temperature of 310° C. and a shear rate of 1,216 sec?1, a pH is 7.0 to 12.0 as measured in a mixed solvent of water/acetone (volume ratio=2/1), a crystallization temperature is at most 220° C. as measured in the course of lowing the temperature of the polymer at a rate of 10° C./min from a molten state, and a whiteness degree is at least 70 as measured in the form of a melt molded or formed product, and a production process thereof.

Abstract: The invention provides a production process of a granular poly(arylene sulfide) by polymerizing a sulfur source and a dihalo-aromatic compound in an organic amide solvent by a polymerization process containing a phase-separation polymerization step, wherein the production process contains a step I of adding an aromatic compound in a proportion of 0.01 to 20 mol per 100 mol of the organic amide solvent into the liquid phase containing the organic amide solvent and a formed polymer within the polymerization reaction system, said liquid phase being in the phase-separated state, after the phase-separation polymerization step; a step II of cooling the liquid phase within the polymerization reaction system; and a step III of collecting the formed polymer from the liquid phase.

Abstract: A polyphenylene sulfide fiber has an amount of heat of crystallization measured by DSC is 10 J/g or more and the degree of shrinkage on dry heating of 150° C.×30 minutes is 20% or less. A method produces a densified wet-laid nonwoven fabric, wherein a wet-laid nonwoven fabric that contains 60 to 100% by mass of a polyphenylene sulfide fiber having an amount of heat of crystallization of 10 J/g or more and wherein the amount of heat of crystallization of the polyphenylene sulfide fiber before heating-pressurizing treatments is 5 J/g or more is subjected to heating-pressurizing treatment at a temperature that is not lower than the glass transition temperature and not higher than the melting point of the polyphenylene sulfide fiber.

Abstract: Disclosed are thioethers, methods for preparing such thioethers, and curable compositions, such as coating and sealant compositions, that include such thioethers. The thioethers can be the reaction product of (a) an alpha, omega dihalo organic compound, (b) a metal hydrosulfide, and (c) a metal hydroxide.

Abstract: A composite material is described that contains a reinforcing resin and reinforcing fibers, wherein the reinforcing fibers have a coating containing polyphenylene sulfide and the proportion of polyphenylene sulfide relative to the uncoated fibers is 0.001 to <0.01 wt. %. The composite material shows higher apparent interlaminar shear strength and bending strength as compared with similar composite materials having no PPS coating in the above concentration range.

Abstract: A process for producing a poly(arylene sulfide) including a charging step 1 of preparing a charging mixture containing an organic amide solvent, a sulfur source, an alkali metal hydroxide, water and a dihalo-aromatic compound and having a pH of at least 12.5; a first-stage polymerization step 2 of heating the mixture to initiate a polymerization reaction, thereby forming a prepolymer that a conversion of the dihalo-aromatic compound is at least 50%; and a second-stage polymerization step 3 of adding a phase separation agent into the reaction system and adding an alkali metal hydroxide in an amount corresponding to 1 to 10 mol % per mol of the charged sulfur source at a time or in portions, thereby continuing the polymerization reaction.

Abstract: A method for producing an acid group-containing polyarylene sulfide of the present invention includes a reaction step of reacting a polyhaloaromatic compound (a), an alkali metal hydrosulfide (b), an alkali metal carboxylate (c), and an aromatic compound (d) having an elimination group and an acid group, which function in a nucleophilic reaction, in the presence of a solid alkali metal sulfide.

Abstract: A method for producing an acid group-containing polyarylene sulfide of the present invention includes a reaction step of reacting a polyhaloaromatic compound (a), an alkali metal hydrosulfide (b), and an alkali metal carboxylate (c) in the presence of a solid alkali metal sulfide and a lithium ion.

Abstract: The techniques provide a system and a method of producing polyphenylene sulfide (PPS) polymer. The PPS polymer is produced by reacting a sulfur source and a dihaloaromatic compound in the presence of a polar organic compound in a polymerization mixture in a polymerization vessel. The PPS polymer is washed with a base to lower the oligomer content of the PPS polymer and thus the off-gassing during processing.

Abstract: A dehydration step is conducted by heating a mixture containing an organic amide solvent and a sulfur source including an alkali metal hydrosulfide, and a part of an overall charged amount of an alkali metal hydroxide as needed. The mixture remaining within the system after the dehydration step is mixed with a dihalo-aromatic compound, the resultant mixture is heated to conduct a polymerization reaction, and the alkali metal hydroxide is added to the mixture for polymerization reaction continuously or in portions to control the pH of the mixture for polymerization reaction within a range of from 7 to 12.5 from the beginning to the end of the polymerization reaction. The poly(arylene sulfide) according to the present invention has a nitrogen content of at most 800 ppm.

Abstract: In a process for producing a poly(arylene sulfide) by polymerizing a sulfur source and a dihalo-aromatic compound in the presence of an alkali metal hydroxide in an organic amide solvent, the production process comprises washing a polymer obtained by the polymerization with a hydrophilic organic solvent containing water in a proportion of 1 to 30% by weight, thereby collecting a purified polymer, the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer, and a poly(arylene sulfide), the content of nitrogen contained in an extract extracted by a mixed solvent containing 40% by weight of acetonitrile and 60% by weight of water from the purified polymer is at most 50 ppm on the basis of the weight of the polymer.

Abstract: A polyarylene sulfide has a narrow molecular weight distribution and a high molecular weight and high purity which is industrially useful, wherein the polyarylene sulfide has a weight average molecular weight of 10,000 or more, and weight loss when heated, ?Wr=(W1?W2)/W1 × 100?0.18(%) (wherein ?Wr is weight loss ratio (%), W1 is sample weight when arrived at 100° C. and W2 is sample weight when arrived at 330° C.). Its production method includes a polyarylene sulfide prepolymer which contains a cyclic polyarylene sulfide at least 50 wt % or more, and of which weight average molecular weight is less than 10,000 is heated to be converted to a high polymer of which weight average molecular weight is 10,000 or more.

Abstract: A poly(arylene sulfide) having properties that a melt viscosity is 1 to 3,000 Pa·s as measured under conditions of a temperature of 310° C. and a shear rate of 1,216 sec?1, a pH is 7.0 to 12.0 as measured in a mixed solvent of water/acetone (volume ratio=2/1), a crystallization temperature is at most 220° C. as measured in the course of lowing the temperature of the polymer at a rate of 10° C./min from a molten state, and a whiteness degree is at least 70 as measured in the form of a melt molded or formed product, and a production process thereof.

Abstract: A poly(arylene sulfide) having properties that a melt viscosity is 1 to 3,000 Pa·s as measured under conditions of a temperature of 310° C. and a shear rate of 1,216 sec?1, a pH is 7.0 to 12.0 as measured in a mixed solvent of water/acetone (volume ratio=2/1), a crystallization temperature is at most 220° C. as measured in the course of lowing the temperature of the polymer at a rate of 10° C./min from a molten state, and a whiteness degree is at least 70 as measured in the form of a melt molded or formed product, and a production process thereof.

Abstract: There is provided a method for producing a poly(arylene sulfide) in which a dihalo-aromatic compound and an alkali metal halide are polymerized by heating in an organic amide solvent, wherein the cooling time for the polymerization reaction system is significantly reduced. After the polymerization process, there is provided a cooling process for cooling the polymerization reaction system comprising a liquid phase containing the product poly (arylene sulfide) and the organic amide solvent and a vapor phase containing a gas component (A); and in the cooling process, the gas component (A) in the vapor phase is cooled while the content of a low boiling gas component (A1), which has a lower boiling point than water and exists in the gas component (A), is reduced in the vapor phase of the polymerization system.

Abstract: It is aimed to provide a polyarylene sulfide film for an acoustic instrument vibrating plate excellent in heat resistance, molding processability, acoustic properties, and also heat moldability. Provided is a polyarylene sulfide film wherein the elongation at break in either a longitudinal direction or a width direction of the film is 100% or more and 250% or less, and the Young's modulus in either a longitudinal direction or a width direction of the film is 1.5 GPa or more and less than 4 GPa.

Abstract: Stabilizer system for chlorinated polymers, especially PVC, comprising at least one coordination-polymeric triethanolamineperchlorato(triflato)metal inner complex comprising the monomer unit of the formula (A) The stabilizer system may additionally comprise substituted cyanoacetylureas or/and 6-aminouracils or/and 3-aminocrotonic esters or/and hydantoins or/and monomeric or polymeric dihydropyridines or alkaline earth metal hydroxides or/and hydrotalcites or/and dawsonites or/and zeolites or/and glycidyl compounds or/and cyanamides or/and cyanoguanidines or/and melamines. In addition, phosphites or/and sterically hindered amines or/and NOR-HALS compounds may be present.

Abstract: In the dehydration step, a mixture comprising an organic amide solvent and a sulfur source is heated, vapor volatilized is guided to a distillation column, a fraction comprising the organic amide solvent as a principal component is refluxed into a reaction vessel, a fraction comprising water and hydrogen sulfide is cooled to discharge hydrogen sulfide that is not condensed by the cooling and reflux a part of water condensed into the distillation column, the remaining water is discharged, a relational expression between the total amount of water of an amount of water refluxed and an amount of water discharged without being refluxed, and an amount of hydrogen sulfide discharged from the reaction vessel is determined in advance, and an amount of hydrogen sulfide discharged from the reaction vessel is calculated out from a measured value of the total amount of water on the basis of the relational expression to control a charged molar ratio of the sulfur source to a dihalo-aromatic compound.

Abstract: A dehydration step is conducted by heating a mixture containing an organic amide solvent and a sulfur source including an alkali metal hydrosulfide, and a part of an overall charged amount of an alkali metal hydroxide as needed. The mixture remaining within the system after the dehydration step is mixed with a dihalo-aromatic compound, the resultant mixture is heated to conduct a polymerization reaction, and the alkali metal hydroxide is added to the mixture for polymerization reaction continuously or in portions to control the pH of the mixture for polymerization reaction within a range of from 7 to 12.5 from the beginning to the end of the polymerization reaction. The poly(arylene sulfide) according to the present invention has a nitrogen content of at most 800 ppm.

Abstract: The present invention is a process for the production of polyarylene sulfide based resin, wherein in washing a polyarylene sulfide based resin with a mixed solvent of an aprotic organic solvent and water in a softened or molten state, the polyarylene sulfide based resin partially dissolved in the washing liquid is recovered, to be specific, the polyarylene sulfide based resin dissolved in the washing liquid is precipitated, separated and recovered by cooling the washing liquid after washing and/or adding water to the washing liquid, and it is reused. According to the present invention, capable of being provided is a process for the production of polyarylene sulfide based resin in which the polyarylene sulfide based resin formed by polymerization is scarcely lost in washing the above resin with a solvent.

Abstract: This invention provides a method for producing a polyarylene sulfide, comprising the step of bringing a low-hydrated alkali metal sulfide containing respectively 0.05 to less than 0.8 mole of water and an organic amide solvent per mole of the sulfur contained in the alkali metal sulfide, into contact with a dihalogenated aromatic compound in an organic polar solvent for polymerization. This invention also provides a polyarylene sulfide obtained by the method. The problem to be solved by this invention is to provide a method for efficiently producing a polyarylene sulfide in a short time using an alkali metal sulfide small in water content and organic amide solvent content.

Abstract: The present invention relates to a composition for optical materials, comprising (a) a compound having in one molecule at least one structure represented by the following Formula 1: wherein R1 is a single bond or a C1-10 hydrocarbon group, each of R2, R3 and R4 is a C1-10 hydrocarbon group or hydrogen, Y is O, 5, Se or Te, m is 1 to 5, and n is 0 to 5; (b) a compound having in one molecule at least one isocyanate group and/or at least one isothiocyanate group; (c) a compound having in one molecule at least one mercapto group; and (d) an inorganic compound having sulfur atom and/or selenium atom, and also relates to an optical material produced by polymerization curing the composition, a production method thereof, and an optical lens comprising the optical material. The present invention provides a high refractive, high Abbe's number optical material having an improved impact resistance.

Abstract: A process for continuous production of a branched polyarylene sulfide, which includes pre-polymerizing a sulfur source with a dihalogenated aromatic compound in such a manner that the reaction rate of the dihalogenated aromatic compound is less than 95% so as to produce a polyarylene sulfide, prepolymer, and polymerizing the prepolymer in the presence of a branching agent while dispersing the phase of the polymer into the form of spherical droplets in the phase of a solvent. When the prepolymer is added to the solvent phase to which a phase separator is beforehand added, spherical droplets of the polymer phase can be produced.

Abstract: There is disclosed a process for continuously producing a polyarylene sulfide which comprises reacting a sulfur source with a dihalogenated aromatic compound in an aprotic organic solvent, characterized by maintaining the content of the dihalogenated aromatic compound in the polymerization liquid after the substantial completion of the polymerization reaction at 5 mg/g or higher. It is made possible by the process according to the present invention to efficiently produce the polyarylene sulfide which has a high molecular weight and is excellent in thermal stability.

Abstract: There is disclosed a process for treating a by-product salt of a polyarylene sulfide which comprises subjecting solid matter containing an aprotic organic solvent and the by-product salt that is formed in the case of producing a polyarylene sulfide by polymerization condensation reaction of an alkali metal sulfide and a dihalogenated aromatic compound in the aprotic organic solvent to a drying treatment followed by a firing treatment of the resultant dryingly treated matter at a temperature in the range of 500 to 1000° C. The above process is capable of enhancing the solubility in water, of the by-product salt comprising sodium chloride as the principal component in the production of polyarylene sulfide, and affording waste water which is lowered in SS and COD in the case where the by-product salt is dissolved in water and is discharged as waste water.

Abstract: The polymerizable compositions comprise: A) at least one polyiso(thio)cyanate monomer, and at least one polythiol monomer; or at least one episulfide compound and optionally one or more compounds having two or more functional groups capable of reacting with episulfide groups; and B) as polymerization catalyst, an effective amount of a salt of formula MmP+Yn? Y? is an anion such as the corresponding acid YH has a pKa fulfilling the condition 0.5?pKa?14 with the proviso that when the polymerizable compositions comprise an episulfide compound and MP+ is an ammonium group, the polymerizable composition also comprises an electro-donor compound. Application to the fabrication of optical articles, such as lenses.

Abstract: The invention relates to an ionic compound corresponding to the formula [R1X1(Z1)—Q?—X2(Z2)—R2]m Mm+ in which Mm+ is a cation of valency m, each of the groups Xi is S?Z3, S?Z4, P—R3 or P—R4; Q is N, CR5, CCN or CSO2R5, each of the groups Zi is ?O, ?NC?N, ?C(C?N)2, ?NS (?Z)2R6 or ?C[S(?Z)2R6]2, each of the groups Ri, is Y, YO—, YS—, Y2N— or F, Y represents a monovalent organic radical or alternatively Y is a repeating unit of a polymeric frame. The compounds are useful for producing ion conducting materials or electrolytes, as catalysts and for doping polymers.

Abstract: There is provided a method for producing a poly(arylene sulfide) in which a dihalo-aromatic compound and an alkali metal halide are polymerized by heating in an organic amide solvent, wherein the cooling time for the polymerization reaction system is significantly reduced. After the polymerization process, there is provided a cooling process for cooling the polymerization reaction system comprising a liquid phase containing the product poly (arylene sulfide) and the organic amide solvent and a vapor phase containing a gas component (A); and in the cooling process, the gas component (A) in the vapor phase is cooled while the content of a low boiling gas component (A1), which has a lower boiling point than water and exists in the gas component (A), is reduced in the vapor phase of the polymerization system.

Abstract: Provided is a method of purifying a polyarylene sulfide by washing it with a mixture of an aprotic organic solvent and an alkyl halide, or with a mixture prepared by adding a halogenoaromatic compound having an electron-withdrawing group to an aprotic organic solvent. The method makes it possible to reduce the impurities such as alkali metal halides in polyarylene sulfide, thus giving thermally stable polyarylene sulfide.

Abstract: A facility of collecting a component of high melting point in a gas, excellent in treating efficiency and having a relatively simple structure is provided.

Abstract: There is disclosed a process for treating a by-product salt of a polyarylene sulfide which comprises subjecting solid matter containing an aprotic organic solvent and the by-product salt that is formed in the case of producing a polyarylene sulfide by polymerization condensation reaction of an alkali metal sulfide and a dihalogenated aromatic compound in the aprotic organic solvent to a drying treatment followed by a firing treatment of the resultant dryingly treated matter at a temperature in the range of 500 to 1000° C. The above process is capable of enhancing the solubility in water, of the by-product salt comprising sodium chloride as the principal component in the production of polyarylene sulfide, and affording waste water which is lowered in SS and COD in the case where the by-product salt is dissolved in water and is discharged as waste water.

Abstract: A process for producing oxidative cross-linked polyarylene sulfide using a reaction apparatus including a reaction vessel provided with a resin inlet, a gas inlet, a resin outlet, and a gas outlet, and a transverse type heating member having a helical structure which is rotatable around a central shaft disposed in the reaction vessel. The process includes the step of supplying heated oxygen containing gas to the polyarylene sulfide from the downward direction of the transverse type heating member while the polyarylene sulfide is heated and agitated by the rotation of the transverse type heating member to carry out an oxidative cross-linking reaction of the polyarylene sulfide. According to the process, it becomes possible to increase the productivity and the gas components present in polyarylene sulfide can be effectively removed when the melt viscosity of polyarylene sulfide is increased to a desired degree after polymerizing the polyarylene sulfide.

Abstract: There is disclosed a process for treating a by-product salt from a polyarylene sulfide which comprises treating a solid mixture containing an aprotic organic solvent and the by-product salt that is formed in the case of producing the polyarylene sulfide by subjecting an alkali metal sulfide and a dihalogenated aromatic compound to polymerization condensation reaction in the aprotic organic solvent, characterized in that the aprotic organic solvent is recovered by dry treating the solid mixture by the use of a dryer having a self-cleaning property. It is enabled by the above process to efficiently recover the aprotic organic solvent, and thereby produce the objective polyarylene sulfide at a lower cost.

Abstract: In the preparation of polyarylene sulfide (PAS) by reacting an alkali metal sulfide with a dihaloaromatic compound in an organic amide solvent to obtain a polyarylene sulfide slurry and subjecting the slurry to acid treatment, an acid or hydrogen salt is added to the slurry in such an amount that a pH of the slurry is more than 7.0 and at most 11.0 to carry out the acid treatment. Alternatively, a zinc compound in an amount of 0.1 to 1.5 mole % per mole of the alkali metal sulfide supplied is added to the polyarylene sulfide slurry to treat the slurry, and, then, an acid or hydrogen salt in an amount of at least 0.2 mole % per mole of the alkali metal sulfide supplied is added. The PAS thus obtained has high crystallization speed, high whiteness, high mechanical strength and high melt viscosity, V6.

Abstract: Provided are a polyarylene sulfide having a chloroform soluble content of at most 0.5% by weight and having an inherent viscosity &eegr;inh of from 0.05 to 0.4; a polyarylene sulfide resin composition comprising a polyarylene sulfide and an inorganic filler, of which the chloroform soluble content is at most 0.5% by weight relative to the polyarylene sulfide in the composition; car parts produced through injection molding of the composition; and a method for producing a polyarylene sulfide. The polyarylene sulfide has a reduced content of low-molecular components, and has well balanced properties of fluidity, flexural strength and impact resistance.

Abstract: Provided is a production process for polyarylene sulfide having a high molecular weight and an excellent heat stability. It is a production process for polyarylene sulfide by reacting a dihalogenoaromatic compound with metal sulfide in a polar solvent, wherein all or a part of water required for the reaction is added on a condition that the reaction system is 100° C. or higher, whereby obtained is polyarylene sulfide which is reduced in an intrinsic viscosity [&eegr;] by 0.05 deciliter/g or less at 206° C. when added to an N-methyl-2-pyrrolidone solvent is the polyarylene sulfide of an amount equivalent to the solvent and it is maintained at 265° C. for 8 hours.

Abstract: In a multistage counter current wash operation wherein an original solvent contained in a cake of polymeric material is displaced with a wash solvent which enters the final stage and progresses forwardly a mathematical model of the counter current wash operation is developed for providing a feedforward control system. In use, the feedforward control system maintains a desired weight fraction of the original solvent that remains in the cake exiting the final wash stage at a desired low level by manipulating the wash solvent flow rate as a function of the flow rate of the feed material. Additionally a feedback control is used in conjunction with the feedforward control.

Abstract: In the preparation of polyarylene sulfide (PAS) by reacting an alkali metal sulfide with a dihaloaromatic compound in an organic amide solvent to obtain a polyarylene sulfide slurry and subjecting the slurry to acid treatment, an acid or hydrogen salt is added to the slurry in such an amount that a pH of the slurry is more than 7.0 and at most 11.0 to carry out the acid treatment. Alternatively, a zinc compound in an amount of 0.1 to 1.5 mole % per mole of the alkali metal sulfide supplied is added to the polyarylene sulfide slurry to treat the slurry, and, then, an acid or hydrogen salt in an amount of at least 0.2 mole % per mole of the alkali metal sulfide supplied is added.

Abstract: A process for producing oxidative cross-linked polyarylene sulfide using a reaction apparatus including a reaction vessel provided with a resin inlet, a gas inlet, a resin outlet, and a gas outlet, and a transverse type heating member having a helical structure which is rotatable around a central shaft disposed in the reaction vessel. The process includes the step of supplying heated oxygen containing gas to the polyarylene sulfide from the downward direction of the transverse type heating member while the polyarylene sulfide is heated and agitated by the rotation of the transverse type heating member to carry out an oxidative cross-linking reaction of the polyarylene sulfide. According to the process, it becomes possible to increase the productivity and the gas components present in polyarylene sulfide can be effectively removed when the melt viscosity of polyarylene sulfide is increased to a desired degree after polymerizing the polyarylene sulfide.

Abstract: A resin composition is provided which composition comprises 100 parts by weight of (A) polyarylene sulfide, and 0.01 to 5.0 parts by weight of (B) a product compound of an element selected from the group consisting of group IIA and group IIB of the periodic table, wherein said product compound has such alkalinity that a mixture of said product compound with a 20-fold weight of ultrapure water of grade A4 specified in the Japanese Industrial Standards (JIS) K0557 has a pH of from 10.0 to 12.0. The composition is particularly suited to be used for an optical instrument part such as an object lens driving unit and the like.

Abstract: Provided is a polyarylene sulfide resin composition having well-balanced fluidity and mechanical strength. The composition is such that its spiral flow length, x (mm), to give a molding having a thickness of 1 mm and the flexural strength, y (MPa), of the molding satisfy the following numerical formula (I), and comprises (A) from 50 to 70 parts by weight of a polyarylene sulfide resin, (B) from 30 to 50 parts by weight of glass fibers and (C) from 0 to 3 parts by weight, relative to 100 parts by weight of the polyarylene sulfide resin (A), of a coupling agent. y≧−(3x/10)+340  (I) wherein x falls between 100 and 300.

Abstract: Provided are a polyarylene sulfide resin and its composition of which the moldings are burred little and which has good mechanical properties and good flow moldability. The composition comprises from 20 to 90% by weight of a polyarylene sulfide and from 10 to 80% by weight of an inorganic filler, and is characterized in that its burrs are on the level of at most 120 &mgr;m, that it has a weld strength of at least 50 MPa and that the length of its spiral flow having a thickness of 1 mm is at least 100 mm. Preferably, the polyarylene sulfide to be in the composition has a specific index to the degree of branching and a specific flexural strength.

Abstract: There is disclosed a process for treating a by-product salt from a polyarylene sulfide which comprises treating a solid mixture containing an aprotic organic solvent and the by-product salt that is formed in the case of producing the polyarylene sulfide by subjecting an alkali metal sulfide and a dihalogenated aromatic compound to polymerization condensation reaction in the aprotic organic solvent, characterized in that the aprotic organic solvent is recovered by dry treating the solid mixture by the use of a dryer having a self-cleaning property. It is enabled by the above process to efficiently recover the aprotic organic solvent, and thereby produce the objective polyarylene sulfide at a lower cost.

Abstract: A process is provided for curing poly(arylene sulfide) polymers by achieving and maintaining curing conditions in a cure vessel, then intermittently adding uncured polymer to said cure vessel and intermittently removing polymer from the cure vessel wherein the removal of polymer from the cure vessel is performed at intervals such that the presence of uncured polymer is minimized or avoided.

Abstract: A process is provided to recover at least one modifier compound and at least one polar organic compound from a poly(arylene sulfide) reaction mixture comprising high molecular weight poly(arylene sulfide), low molecular weight poly(arylene sulfide), cyclic and linear poly(arylene sulfide) oligomers, at least one polar organic compound, at least one modifier compound, and an alkali metal halide by-product.