PRODUCTION METHOD FOR POLYACRYLIC ACID (POLYACRYLATE) WATER-ABSORPTIVE RESIN

摘要

Provided is a water-absorptive resin production method that can prevent defects associated with the addition of a particulate additive or a water-absorptive resin fine powder and can stably and efficiently produce a water-absorptive resin that has high physical properties. A polyacrylic acid (polyacrylate) water-absorptive resin production method that includes: a monomer aqueous-solution preparation step for preparing an aqueous solution that includes a monomer that has acrylic acid (acrylate) as a principal component; a polymerization step for polymerizing the monomer and obtaining a hydrous gel-like crosslinked polymer; and a drying step for drying the hydrous gel-like crosslinked polymer and obtaining a dried polymer. The polyacrylic acid (polyacrylate) water-absorptive resin production method also includes an addition step for adding a particulate additive to the monomer aqueous solution and/or to the hydrous gel-like crosslinked polymer, the oxygen concentration of the atmosphere surrounding the particulate additive during the addition step being 5 vol% or less.