To provide a method for producing PAS by which PAS having a small particle size of 50 μm or greater and 550 μm or less as an average particle size can be produced.

In the method for producing PAS, including: (1) a preparation step of preparing a prepared mixture containing an organic polar solvent, a sulfur source, and a dihalo aromatic compound; (2) a pre-stage polymerization step of initiating a polymerization reaction by heating the prepared mixture to produce a prepolymer; (3) a phase separation step of adding water as a phase separation agent to a reaction mixture in a reaction system to form a phase separation state; and (4) a post-stage polymerization step of continuing the polymerization reaction after the phase separation step, in which an organic sulfonic acid metal salt having a specific solubility in water is contained in the prepared mixture or the reaction mixture.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

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.

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.

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.

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.

Provided are a continuous production method and a continuous production apparatus utilizing the solution polycondensation for aromatic cyclic oligomers, which achieve a good space-time yield and are inexpensive and simple. The continuous production method includes: (a) supplying a polymerization solvent and a reaction raw material to a continuous production apparatus; (b) performing a polymerization reaction in the reaction vessels to form a reaction mixture; (c) removing water in gas phase parts of the reaction vessels from the reaction vessels; and (d) successively moving the reaction mixture to each of the reaction vessels; the steps (a), (b), (c), and (d) being performed in parallel; wherein an amount of the polymerization solvent in the reaction vessel positioned furthest downstream in a movement direction of the reaction mixture is not less than 1 L and not greater than 50 L per 1 mol of arylene units in the reaction raw material.

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.

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.