Abstract: The present invention is a production method for producing polyarylene sulfide, wherein an unreacted dihalo aromatic compound is recovered and reused. The present production method includes: (a) a polymerization step; (b) a separation step; and (c) a recovery step of recovering unreacted dihalo aromatic compound from a water-containing mixture of the separated liquid by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water.

Abstract: To provide: a method of manufacturing granular polyarylene sulfide (PAS) with improved particle strength while improving the yield of the granular PAS by introducing and recovering PAS with a moderate molecular weight in granular PAS; and granular PAS. A method of manufacturing granular PAS according to the present invention includes: a polymerizing step of subjecting a dihalo aromatic compound and at least one type of sulfur source selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides to polymerization reaction in an organic amide solvent; and a cooling step of cooling the reaction product mixture after the polymerizing step. Addition of a phase separation agent to the reaction product mixture is started at a point in time from the start of the polymerizing step to before the start of forming granular PAS in the cooling step, and when the temperature of the reaction product mixture is 245° C.

Abstract: The present invention provides a production method and a production apparatus for a polyarylene sulfide (PAS), thus the formation of a floating polymer and the leakage of the floating polymer to the outside of the vessel in a washing step are prevented, to achieve steady production of the polymer with high quality, to improve the yield of the polymer and to reduce environmental load, wherein the floating polymer refers to a particles of the polymer which are floating on the surface of a washing solution, in the upper part of the inside of a washing vessel, as a result of the adhesion of a gas onto the surface of the particles of the polymer.

Abstract: The present invention is a production method for producing polyarylene sulfide, wherein an unreacted dihalo aromatic compound is recovered and reused. The present invention is a production method for producing polyarylene sulfide, the method include: (a) a polymerization step; (b) a separation step; and (c) a recovery step of recovering an unreacted dihalo aromatic compound from a water-containing mixture in the form of a water-containing liquid mixture containing the separated liquid by steam distillation entailing adjusting the reflux ratio of water in the steam distillation column without adding water other than the refluxed water.

Abstract: A heat treated fine polyarylene sulfide powder. (i) The heat treated fine polyarylene sulfide powder is manufactured from separation liquid. (ii) The heat treated fine polyarylene sulfide powder is obtained by subjecting the separation liquid to solid-liquid separation to obtain a raw material fine powder polyarylene sulfide. Thereafter the raw material fine powder polyarylene sulfide is subjected to pre-heat treatment and heat treatment. (iii) The heat treated fine polyarylene sulfide powder has an average particle size of from 1 to 80 ?m. (iv) The heat treated fine polyarylene sulfide powder has a melt viscosity of 1 Pa·s or greater. (v) A generated gas amount of the heat treated fine polyarylene sulfide is 10 ppm or less.

Abstract: The present invention provides a production method and a production apparatus for a polyarylene sulfide (PAS), thus the formation of a floating polymer and the leakage of the floating polymer to the outside of the vessel in a washing step are prevented, to achieve steady production of the polymer with high quality, to improve the yield of the polymer and to reduce environmental load, wherein the floating polymer refers to a particles of the polymer which are floating on the surface of a washing solution, in the upper part of the inside of a washing vessel, as a result of the adhesion of a gas onto the surface of the particles of the polymer.

Abstract: A longitudinal solid-liquid countercurrent contact method and apparatus are provided in which an aqueous slurry containing solid particles is supplied from an upper part and is caused to pass through a plurality of contact-processing chambers connected in a vertical direction while being caused to proceed downward, a contacting liquid is supplied from a lower part and is caused to pass through the plurality of contact-processing chambers connected in the vertical direction while being caused to proceed upward, and the aqueous slurry and the contacting liquid are caused to be continuously subjected to countercurrent contact, wherein the viscosity of a liquid phase in at least one of the contact-processing chambers is controlled, and especially the viscosity ?1 of a liquid phase in a contact-processing chamber positioned at an uppermost part is controlled to fall within a range of 0.9??1/?0?2.

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 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 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: 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 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 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: 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: 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: 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: 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 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.