Abstract: Provided are an adsorbent which can be used in water, particularly even under strong acid conditions, and which has excellent adsorptivity, a method for efficiently separating a separation object substance from a liquid containing the separation object substance using the adsorbent, and further a method for producing a liquid having a separation object substance reduced. More specifically, provided are a method for separating a separation object substance and a liquid using polyarylene sulfide resin particles as an adsorbent from the liquid containing the separation object substance, wherein the liquid contains water, and further a method for producing a liquid having a separation object substance reduced, comprising efficiently separating a separation object substance from a liquid containing the separation object substance using an adsorbent which can be used in water, particularly even under strong acid conditions, and which has excellent adsorptivity.

Abstract: Provided are a purification method for a polyarylene sulfide (PAS) that can efficiently reduce the amount of a carboxyalkylamino group-containing compound in the PAS by treating the carboxyalkylamino group-containing compound in the PAS under a low pressure without using a strong acid, and a production method for a PAS having a reduced amount of the carboxyalkylamino group-containing compound in the PAS. The purification method for a PAS includes: a step of obtaining a crude PAS-containing mixture by removing a solvent from a crude reaction product containing the PAS obtained by reacting a polyhalo aromatic compound with a sulfidizing agent in an organic polar solvent; a step of bringing the crude PAS mixture into contact with water and an oxygen atom-containing solvent to convert the crude PAS into porous particles; and a step of bringing the obtained porous particles into contact with carbonated water.

Abstract: Provided is a method for producing a polyarylene sulfide resin, the method including subjecting a dihaloaromatic compound and a sulfidizing agent to a polymerization reaction in the presence of an aliphatic cyclic compound having a ring openable by hydrolysis, in which corrosion of a production apparatus is suppressed. More particularly, provided is a method for producing a polyarylene sulfide resin, the method including a dehydration step (1) in which a water-containing sulfidizing agent and an aliphatic cyclic compound having a ring openable by hydrolysis are heated in the presence of a dihaloaromatic compound to a liquid temperature in the range of 90° C. or higher and 170° C. or lower under the atmospheric pressure, and then dehydration is performed while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [kPa abs] or higher and 80 [kPa abs] or lower to thus obtain a mixture.

Abstract: Provided is a method for producing a polyarylene sulfide resin, the method including subjecting a dihaloaromatic compound and a sulfidizing agent to a polymerization reaction in the presence of an aliphatic cyclic compound having a ring openable by hydrolysis, in which corrosion of a production apparatus is suppressed. More particularly, provided is a method for producing a polyarylene sulfide resin, the method including a dehydration step (1) in which a water-containing sulfidizing agent and an aliphatic cyclic compound having a ring openable by hydrolysis are heated in the presence of a dihaloaromatic compound to a liquid temperature in the range of 90° C. or higher and 170° C. or lower under the atmospheric pressure, and then dehydration is performed while maintaining the liquid temperature and reducing the pressure to a pressure in the range of 30 [kPa abs] or higher and 80 [kPa abs] or lower to thus obtain a mixture.