Abstract: The present invention relates to a method for producing a solubilized polymer by decomposing a recovered water-absorbent resin to produce a solubilized polymer, the method including preparing a mixture containing a recovered water-absorbent resin, water, and a peroxide (excluding persulfates), wherein the mixture has a pH of 6.5 or more and 8.5 or less. The present invention also relates to a method for producing a water-absorbent resin, the method including using, as a part of a raw material, a solubilized polymer produced by decomposing a recovered water-absorbent resin. According to the present invention, a means capable of solubilizing (decomposing) a recovered water-absorbent resin in a short time without using a large amount of decomposer.

Abstract: Provided is a method for producing a solubilized polymer-containing material that makes it possible to efficiently decompose water-absorbent resins to efficiently produce the solubilized polymer-containing material, and provide a method for producing a water-absorbent resin in which a portion of the solubilized polymer-containing material is used as a raw material. The method for producing a solubilized polymer-containing material includes a heat treatment step of heat-treating a mixture containing a water-absorbent resin, water, and a peroxide under conditions satisfying the following i) and ii), in which a mass average molecular weight (Mw) of a water-soluble content of a solubilized polymer-containing material obtained in the heat treatment step is from 30000 to 1000000: i) a solid content concentration of the mixture is 60 mass % or greater, and ii) a temperature of the heat treatment is 60° C. or higher.

Abstract: Provided is a particulate water-absorbing agent that can be used for producing a sanitary product capable of further reducing the re-wetting of absorbed liquid in actual use. The subject particulate water-absorbing agent is a particulate water-absorbing agent having a fluid retention capacity of more than 50 g/g when a swollen gel obtained by bringing the particulate water-absorbing agent into contact with a 0.9% aqueous sodium chloride solution for 10 minutes is let stand for 1 minute without pressure, and having a fluid retention capacity of more than 41.5 g/g when the swollen gel is let stand for 1 minute under a pressure of 4.83 kPa.