Patent ID: 9138505
Filing Date: 2015-09-22
Classification: A61L,C08F,C08J

Abstract:
1. A method for producing a polyacrylic acid (salt) water absorbent resin, comprising steps of: preparing an aqueous monomer solution of acrylic acid (salt), polymerizing the aqueous monomer solution, finely shredding a hydrous gel-like crosslinked polymer during or after polymerization, drying the obtained particulate hydrous gel-like crosslinked polymer, crushing the dried polymer, classifying the dried polymer, heating and surface-crosslinking the dried polymer after the classification, and cooling after the surface-crosslinking, wherein the inner surface area of a cooling apparatus to be used in the cooling step is 0.25 to 0.95 times as large as the inner surface area of a heating apparatus to be used in the heating and surface-crosslinking step.