PARTICULATE WATER ABSORBENT AND METHOD FOR PRODUCING SAME

摘要

Disclosed is a particulate water absorbent for an absorbent material, which is mainly composed of a polyacrylic acid (salt) water absorbent resin and exhibits excellent water absorption performance, while having excellent performance of preventing coloring over time. The particulate water absorbent has no odor and is suitable for practical use. Also disclosed is a method for producing a particulate water absorbent mainly composed of a polyacrylic acid (salt) water absorbent resin, which comprises: a step of polymerizing an aqueous monomer solution that is mainly composed of an acrylic acid (salt) that contains 10-200 ppm of a methoxyphenol; a step of drying a hydrated gel-like crosslinked polymer that is obtained by the polymerization; and a surface crosslinking step. The method for producing a particulate water absorbent is characterized by comprising a step of adding a chelating agent and an inorganic reducing agent and by satisfying the following condition (a) and/or (b). (a) The method comprises a step of adding water-insoluble inorganic fine particles. (b) In the drying step and the surface crosslinking step, the moisture content of the polymer is controlled to 3-15% by weight.