A polyarylene sulfide in which when the cumulative integral value from the molecular weight of 100 to the molecular weight of 10,000 in a molecular weight distribution curve is 100, the cumulative integrated value at the molecular weight of 4000 is 48 to 53, and when the melt flow rate of the polyarylene sulfide is defined as MFR1, and when the melt flow rate obtained after mixing the polyarylene sulfide with an epoxy silane coupling agent at a weight ratio of 100:1 and heating the resulting mixture at 315.5° C. for 5 minutes is defined as MFR2, the rate of change represented by MFR2/MFR1 is not more than 0.085.

A polyarylene sulfide in which when the cumulative integral value from the molecular weight of 100 to the molecular weight of 10,000 in a molecular weight distribution curve is 100, the cumulative integrated value at the molecular weight of 4000 is 48 to 53, and when the melt flow rate of the polyarylene sulfide is defined as MFR1, and when the melt flow rate obtained after mixing the polyarylene sulfide with an epoxy silane coupling agent at a weight ratio of 100:1 and heating the resulting mixture at 315.5° C. for 5 minutes is defined as MFR2, the rate of change represented by MFR2/MFR1 is not more than 0.085.

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. or higher); and a second-stage polymerization step of adding, in the reaction system, an alkali metal hydroxide in an amount of 1 to 20 mol % per 1 mol of the sulfur source in the presence of a phase separation agent to continue the polymerization reaction at 245 to 290° C. PAS having a melt viscosity (310° C.; shear rate: 1216 sec.sup.-1) of 0.1 to 8000 Pa.Math.s produced by the method.

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. or higher); and a second-stage polymerization step of adding, in the reaction system, an alkali metal hydroxide in an amount of 1 to 20 mol % per 1 mol of the sulfur source in the presence of a phase separation agent to continue the polymerization reaction at 245 to 290° C. PAS having a melt viscosity (310° C.; shear rate: 1216 sec.sup.-1) of 0.1 to 8000 Pa.Math.s produced by the method.

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.

The present invention provides an a polyarylene sulfide (PAS) production device provided with a supply tube for loading corrosive materials such as a strong alkali into a reaction vessel, wherein prescribed amounts of various raw materials or the like can be accurately loaded into the reaction vessel without causing decreases in production efficiency due to the replacement of the supply tube or the repair of the reaction vessel in response to the corrosion of the supply tube or the like.

The present invention is a production device, and a PAS production device, in particular, provided with a reaction vessel equipped with one or a plurality of supply tubes, at least one of the supply tubes having an insert pipe, which is preferably detachable, to be inserted into an outer supply tube; and a tip opening of the insert pipe being positioned further inward than an inside wall of the reaction vessel.

The present invention provides an a polyarylene sulfide (PAS) production device provided with a supply tube for loading corrosive materials such as a strong alkali into a reaction vessel, wherein prescribed amounts of various raw materials or the like can be accurately loaded into the reaction vessel without causing decreases in production efficiency due to the replacement of the supply tube or the repair of the reaction vessel in response to the corrosion of the supply tube or the like.

The present invention is a production device, and a PAS production device, in particular, provided with a reaction vessel equipped with one or a plurality of supply tubes, at least one of the supply tubes having an insert pipe, which is preferably detachable, to be inserted into an outer supply tube; and a tip opening of the insert pipe being positioned further inward than an inside wall of the reaction vessel.

A preparation method of a polyarylene sulfide that may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method with a high molecular weight at a high yield by optimizing the content and molar ratio of an amide-based compound in a polymerization step.

A preparation method of a polyarylene sulfide that may produce a polyarylene sulfide having properties equal to or higher than those of the conventional method with a high molecular weight at a high yield by optimizing the content and molar ratio of an amide-based compound in a polymerization step.

A method of producing a PAS according to an embodiment of the present invention includes: a polymerizing step; a water removal step; a hydrogen sulfide recovering step in which hydrogen sulfide contained in a gas component produced in the water removal step is absorbed and recovered by an aqueous solution of an alkali metal hydroxide; and a condensation step in which the gas component produced in the water removal step is condensed. The hydrogen sulfide recovering step is performed before the condensation step.