POLYACRYLIC ACID (SALT) WATER-ABSORBABLE RESIN, AND PROCESS FOR PRODUCTION THEREOF

摘要

[Problem] To provide a process for producing a polyacrylic acid (salt) water-absorbable resin, in which the amount of a residual monomer can be reduced, and which can produce a water-absorbable resin that can be used for a practically suitable absorber in a simple manner. [Solution] A process for producing a polyacrylic acid (salt) water-absorbable resin, which comprises a polymerization step of polymerizing an aqueous monomer solution containing an acrylic acid (salt) as the main component, a drying step of drying a water-containing-gel-like crosslinked polymer produced in the polymerization step, a surface crosslinking step of crosslinking the surface of a water-absorbable resin that is in the middle of drying or has been dried, and a packaging step of packaging the surface-crosslinked water-absorbable resin, wherein the iron content in the aqueous monomer solution in the polymerization step is 2 ppm (relative to the amount of the monomer) or less, the water content in the water-absorbable resin in the packaging step is 1 wt% or more, and a storage step of storing the packaged water-absorbable resin for three days or longer is additionally involved subsequent to the packaging step.