Polyacrylic acid (salt)-based water absorbent resin, and method for producing polyacrylic acid (salt)-based water absorbent resin

Abstract

As a method for producing a polyacrylic acid (salt)-based water absorbent resin particle which less generates fine powder and has an excellent impact resistance and a high moisture content even in a case where the polyacrylic acid (salt)-based water absorbent resin particle is produced on a large scale, employed is a production method including the steps of: (a) adding a surface crosslinking agent solution to water absorbent resin powder to obtain a mixture; (b) reacting the mixture; and, thereafter (c) adding an aqueous liquid to at least one selected from the group consisting of (i) the water absorbent resin powder during the step (b) and (ii) the water absorbent resin powder after the step (b), an atmospheric dew point being not lower than 20° C. in the step (c), and a temperature of the water absorbent resin powder being higher than the atmospheric dew point in the step (c).

Dependencies are inferred from the claim text.