Abstract: A method for producing polyarylene sulfide that can have a high melt viscosity while suppressing ultra-fine powder generation. The method for producing polyarylene sulfide includes: (1) preparing a prepared mixture containing an organic polar solvent, a sulfur source, and a dihalo aromatic compound; (2) initiating a polymerization reaction by heating the prepared mixture to produce a prepolymer; (3) adding water as a phase separation agent to a reaction mixture in a reaction system to form a phase-separated state; and (4) continuing the polymerization reaction after phase separation. In the method, when a dihalo aromatic compound conversion ratio is 80 mass % or greater and 93 mass % or less and after the prepolymer reaches a weight average molecular weight of 10000 or greater in the first-stage polymerization step, an aromatic compound having 3 or more halogen atoms bonded to an aromatic ring is added to the reaction mixture.

Abstract: In production of a polyarylene sulfide (PAS), combination/coalescence and enlargement of the PAS are prevented. A method for producing a PAS according to the present invention includes: first polymerization in which a mixture containing a sulfur source and a dihalo aromatic compound in an organic amide solvent is heated to initiate a polymerization reaction; second polymerization in which a first temperature (T1) is maintained after adding a phase separation agent to continue the reaction; third polymerization in which a second temperature (T2) is maintained to continue the reaction; and fourth polymerization in which the reaction is continued at a third temperature (T3), wherein a relationship among the temperatures is T1>T3>T2.

Abstract: A method of producing a PAS, which is the method capable of providing a PAS having a high melt viscosity in high yield in a shorter polymerization time, is provided. The method including: a preparation step; a first polymerization step; and subsequently a second polymerization step for continuing to perform a polymerization reaction by adding to the reaction mixture from 0.09 to 0.2 mol of an additional alkali metal hydroxide relative to 1 mol of the sulfur source. In the first polymerization step, the polymerization reaction is performed on condition that a pH of the reaction mixture is 11 or higher until a conversion ratio of the dihalo aromatic compound being 50 mol % or greater.

Abstract: A method of producing a polyarylene sulfide (PAS) includes a preparation step of preparing a charged mixture containing an organic amide solvent, a sulfur source, water, and a dihalo aromatic compound; a first-stage polymerization step of performing a polymerization reaction on the charged mixture at a temperature of from 170 to 280° C. to produce a prepolymer having a conversion ratio of the dihalo aromatic compound of 50% or greater; and a second-stage polymerization step of continuing the polymerization reaction in a phase-separated state at a temperature of from 245 to 290° C. in a reaction system containing the prepolymer, and includes adding a polyfunctional compound to the reaction system in the phase-separated state. A PAS having a melt viscosity (310° C., shear rate: 1216 sec?1) of from 0.1 to 8000 Pa·s is produced by the method.

Abstract: The present invention is to provide a method that can produce polyarylene sulfide having a high viscosity at a high yield. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture and producing a prepolymer until a pH of a reaction system reaches a range of 10 to 11; and a second-stage polymerization step of continuing the polymerization reaction.

Abstract: To provide a method for producing granular polyarylene sulfide (hereinafter, PAS), the method capable of providing granular PAS having high particle strength and low melt viscosity in high yield without using special additives and the like; and granular PAS. A method according to the present invention is a method for producing granular PAS having a melt viscosity of from 1 to 30 Pa.s, which is measured at a temperature of 310° C. and a shear rate of 1216/s, by polymerizing a sulfur source and a dihalo aromatic compound in an organic amide solvent.

Abstract: The present invention is to provide a method of producing polyarylene sulfide that can produce polyarylene sulfide having a low halogen content simply and easily and at low cost. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of producing a prepolymer until a pH of a reaction system reaches a range of lower than 10 but 7 or higher by initiating a polymerization reaction by heating the mixture; and a second-stage polymerization step of continuing the polymerization reaction.

Abstract: The present invention is to provide a method of producing polyarylene sulfide that can produce polyarylene sulfide having a low halogen content simply and easily and at low cost. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of producing a prepolymer until a pH of a reaction system reaches a range of lower than 10 but 7 or higher by initiating a polymerization reaction by heating the mixture; and a second-stage polymerization step of continuing the polymerization reaction.

Abstract: Provided are a method of producing a polyarylene sulfide (PAS) by a polymerization reaction of a sulfur source and a dihalo aromatic compound in an organic amide solvent, in which the PAS having a high degree of polymerization can be obtained at a high yield and the generation of a byproduct that imposes a large burden of a waste treatment can be effectively reduced; and a PAS having a high degree of polymerization. The method of producing a PAS includes a preparation step of preparing a charged mixture containing an organic amide solvent, a sulfur source, water, and a dihalo aromatic compound; a first-stage polymerization step of performing a polymerization reaction on the charged mixture at a temperature of from 170 to 280° C. to produce a prepolymer having a conversion ratio of the dihalo aromatic compound of 50% or greater; and a second-stage polymerization step of continuing the polymerization reaction in a phase-separated state at a temperature of from 245 to 290° C.

Abstract: The present invention is to provide a method that can produce polyarylene sulfide having a high viscosity at a high yield. The method of producing polyarylene sulfide according to an embodiment of the present invention includes: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, a dihalo aromatic compound, and an alkali metal hydroxide; a first-stage polymerization step of initiating a polymerization reaction by heating the mixture and producing a prepolymer until a pH of a reaction system reaches a range of 10 to 11; and a second-stage polymerization step of continuing the polymerization reaction.

Abstract: A method of producing polyarylene sulfide (PAS) by subjecting a sulfur source and a dihalo aromatic compound (DHA) to polymerization reaction in an organic amide solvent under alkaline conditions, the method suppressing side reactions or the like and yielding PAS having a high degree of polymerization at a high yield is provided; and PAS having a high degree of polymerization are provided. A method of producing PAS, including: a preparation step of preparing a preparation mixture containing an organic amide solvent, a sulfur source, an alkali metal hydroxide, water, and DHA, and having a pH of 12.5 or higher; a first-stage polymerization step of heating the preparation mixture to 170° C. or higher to initiate a polymerization reaction and continuing the polymerization reaction at 240 to 280° C., thereby forming a prepolymer having a DHA conversion rate of 50% or greater (at this time, a temperature increasing rate from 220° C. to 240° C. is lower than a temperature increasing rate for 240° C.

Abstract: Provided is a method of producing polyarylene sulfide (PAS) that suppresses side reactions and produces PAS with a high purity and a high molecular weight at a high yield. A method of producing PAS in which a sulfur source and a dihalo aromatic compound are polymerized in an organic amide solvent, the method of producing PAS comprising the following steps 1 to 3: step 1: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, water, a dihalo aromatic compound, and an alkali metal hydroxide in an amount that is less than an equimolar amount relative to the sulfur source; step 2: a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion rate of 50% or greater; and step 3: a second-stage polymerization step of adding from 0.11 to 0.3 mol of an alkali metal hydroxide per 1 mol of the sulfur source, and continuing the polymerization reaction.

Abstract: A method of producing polyarylene sulfide (PAS) by subjecting a sulfur source and a dihalo aromatic compound (DHA) to polymerization reaction in an organic amide solvent under alkaline conditions, the method suppressing side reactions or the like and yielding PAS having a high degree of polymerization at a high yield is provided; and PAS having a high degree of polymerization are provided. A method of producing PAS, including: a preparation step of preparing a preparation mixture containing an organic amide solvent, a sulfur source, an alkali metal hydroxide, water, and DHA, and having a pH of 12.5 or higher; a first-stage polymerization step of heating the preparation mixture to 170° C. or higher to initiate a polymerization reaction and continuing the polymerization reaction at 240 to 280° C., thereby forming a prepolymer having a DHA conversion rate of 50% or greater (at this time, a temperature increasing rate from 220° C. to 240° C. is lower than a temperature increasing rate for 240° C.

Abstract: Provided is a method of producing polyarylene sulfide (PAS) that suppresses side reactions and produces PAS with a high purity and a high molecular weight at a high yield. A method of producing PAS in which a sulfur source and a dihalo aromatic compound are polymerized in an organic amide solvent, the method of producing PAS comprising the following steps 1 to 3: step 1: a preparation step of preparing a mixture containing an organic amide solvent, a sulfur source, water, a dihalo aromatic compound, and an alkali metal hydroxide in an amount that is less than an equimolar amount relative to the sulfur source; step 2: a first-stage polymerization step of initiating a polymerization reaction by heating the mixture, and producing a prepolymer having a dihalo aromatic compound conversion rate of 50% or greater; and step 3: a second-stage polymerization step of adding from 0.11 to 0.3 mol of an alkali metal hydroxide per 1 mol of the sulfur source, and continuing the polymerization reaction.

Abstract: A granular polyarylene sulfide; (i) the granular polyarylene sulfide containing an —S— substituent at the terminal, the substituent being formed by cleavage of a disulfide compound; (ii) the granular polyarylene sulfide being an oversize fraction after sifting with a sieve having a mesh size of at least 38 ?m; (iii) the granular polyarylene sulfide having a halogen content of at most 1,500 ppm; and (iv) the granular polyarylene sulfide being a granular polyarylene sulfide having a melt viscosity of 3 to 100 Pa·s when measured under conditions at a temperature of 310° C. and a shear rate of 1,200 sec?1. The granular polyarylene sulfide is well balanced in melt viscosity, halogen content, nitrogen content, thermal stability, and yield.

Abstract: A granular polyarylene sulfide; (i) the granular polyarylene sulfide containing an —S— substituent at the terminal, the substituent being formed by cleavage of a disulfide compound; (ii) the granular polyarylene sulfide being an oversize fraction after sifting with a sieve having a mesh size of at least 38 ?m; (iii) the granular polyarylene sulfide having a halogen content of at most 1,500 ppm; and (iv) the granular polyarylene sulfide being a granular polyarylene sulfide having a melt viscosity of 3 to 100 Pa·s when measured under conditions at a temperature of 310° C. and a shear rate of 1,200 sec?1. The granular polyarylene sulfide is well balanced in melt viscosity, halogen content, nitrogen content, thermal stability, and yield.

Abstract: The invention provides a production process of a poly(arylene sulfide) which contains a step of polymerizing a sulfur source and a dihalo-aromatic compound in an organic amide solvent, said polymerization step containing a phase-separation polymerization step that the polymerization reaction is continued in the presence of a phase separation agent in a phase-separated state, wherein a monohalo-organic compound is added in a proportion of 0.005 to 20 mol per 100 mol of the charged sulfur source into the polymerization reaction system at the time a conversion of the dihalo-aromatic compound has reached 80 to 99% after initiation of the polymerization reaction and before the liquid phase becomes the phase-separated state to be reacted with a formed polymer, and the liquid phase within the polymerization reaction system is then converted to the phase-separated state to continue the polymerization reaction.

Abstract: The invention provides a production process of a poly(arylene sulfide), comprising a polymerization step of subjecting at least one sulfur source selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides and a dihalo-aromatic compound to a polymerization reaction in an organic amide solvent; a reaction step of adding a hydroxyl group-containing organic compound containing no bonded halogen atom in a proportion of 0.001 to 20 mol per 100 mol of the charged sulfur source into the polymerization reaction system containing the organic amide solvent and a formed polymer after the polymerization step to cause the formed polymer to react with the hydroxyl group-containing organic compound; and a collecting step of collecting a polymer from the polymerization reaction system after the reaction step, and the poly(arylene sulfide).

Abstract: The invention provides a production process of a poly(arylene sulfide), comprising a polymerization step of subjecting at least one sulfur source selected from the group consisting of alkali metal sulfides and alkali metal hydrosulfides and a dihalo-aromatic compound to a polymerization reaction in an organic amide solvent; a reaction step of adding a hydroxyl group-containing organic compound containing no bonded halogen atom in a proportion of 0.001 to 20 mol per 100 mol of the charged sulfur source into the polymerization reaction system containing the organic amide solvent and a formed polymer after the polymerization step to cause the formed polymer to react with the hydroxyl group-containing organic compound; and a collecting step of collecting a polymer from the polymerization reaction system after the reaction step, and the poly(arylene sulfide).

Abstract: The invention provides a production process of a poly(arylene sulfide) which contains a step of polymerizing a sulfur source and a dihalo-aromatic compound in an organic amide solvent, said polymerization step containing a phase-separation polymerization step that the polymerization reaction is continued in the presence of a phase separation agent in a phase-separated state, wherein a monohalo-organic compound is added in a proportion of 0.005 to 20 mol per 100 mol of the charged sulfur source into the polymerization reaction system at the time a conversion of the dihalo-aromatic compound has reached 80 to 99% after initiation of the polymerization reaction and before the liquid phase becomes the phase-separated state to be reacted with a formed polymer, and the liquid phase within the polymerization reaction system is then converted to the phase-separated state to continue the polymerization reaction.