Patent ID: 7420018
Filing Date: 2008-09-02
Classification: A61F,A61L,B01J,C08F,C08J,G01N

Abstract:
1. A production process for a water-absorbing agent, comprising the steps of: a) mixing water-absorbent resin particles, an ion blocking agent, and a surface-crosslinking agent to surface-crosslink said water-absorbent resin particles by said surface-crosslinking agent in the presence of said ion-blocking agent, wherein said ion blocking agent is an agent other than said surface-crosslinking agent, wherein said water-absorbent resin particles have a carboxyl group and are obtained by polymerizing and crosslinking an acrylic acid and/or a salt thereof as a main component, wherein said surface-crosslinking agent is reactive with said carboxyl group, and wherein said ion blocking agent is selected from a compound in groups (1) to (5) mentioned below: b) after said step of mixing, heating the water-absorbent resin particles to surface-crosslink the particles; and c) wherein, prior to said step of mixing, the water-absorbent resin particles having a carboxyl group contain a water-soluble content of 25% or below.