PROCESS FOR PRODUCTION OF WATER-ABSORBING RESIN PARTICLES

摘要

A process for producing a water-absorbent resin particle comprising subjecting a water-soluble ethylenically unsaturated monomer to a reverse phase suspension polymerization, characterized in that the process for producing a water-absorbent resin particle comprises the steps of (A) subjecting the water-soluble ethylenically unsaturated monomer to a first-step reverse phase suspension polymerization in a hydrocarbon-based solvent using a water-soluble radical polymerization initiator in the presence of a surfactant and/or a polymeric protective colloid, and optionally an internal crosslinking agent; (B) carrying out at least one step of the procedures of adding an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a water-soluble radical polymerization initiator and optionally an internal crosslinking agent to a reaction mixture after the termination of the first-step reverse phase suspension polymerization in a state that the surfactant and/or the polymeric protective colloid is dissolved in the hydrocarbon-based solvent, and subsequently subjecting the mixture to a reverse phase suspension polymerization; and (C) post-crosslinking the resulting water-absorbent resin.