POLYACRYLIC ACID-BASED WATER-ABSORBING RESIN POWDER AND METHOD FOR PRODUCING THE SAME

摘要

A production method of the present invention is a polyacrylic water-absorbent resin powder production method including the steps of: producing an acrylic monomer solution in which gas is dissolved and/or dispersed; polymerizing the acrylic monomer solution in the absence of a surface active agent or in the presence of not more than 300 ppm of a surface active agent; during or after the step of polymerizing, fragmenting a hydrated gel crosslinked polymer obtained by polymerizing the acrylic monomer solution; and drying by heat the hydrated gel crosslinked polymer thus fragmented, the gas being dissolved and/or dispersed in the acrylic monomer solution by at least one of the methods (a) to (c): (a) applying pressure to the acrylic monomer solution and the gas; (b) creating swirling flows of the acrylic monomer solution and the gas; and (c) introducing the gas with the acrylic monomer solution via fine holes. Accordingly, the production method of the present invention makes it possible to efficiently produce a water-absorbent resin having an excellent water-absorption rate without deteriorating a liquid-absorbent property of a sanitary product or the like.