METHOD FOR PRODUCING WATER-ABSORBING AGENT

PROBLEM TO BE SOLVED: To provide means for producing a surface-crosslinked water-absorbing resin (water-absorbing agent) which has an excellent balance between non-pressure water absorption magnification and water absorption magnification under pressure and has no problem in safety at low temperatures for a short time with a safe method at low cost.SOLUTION: A method for producing a water-absorbing agent containing a poly(meth)acrylic acid (salt)-based water-absorbing resin as a main component includes: a) a step of mixing the water-absorbing resin with 50 pts.wt. or less of a treatment liquid containing a radical polymerizable monomer and an organic-based crosslinking agent with respect to 100 pts.wt. of the water-absorbing resin; and b) a step of crosslinking and polymerizing the radical polymerizable monomer and the organic-based crosslinking agent. The organic-based crosslinking agent has a plurality of functional groups selected from the group consisting of functional groups that can react with a (meth)acrylate group or a carboxyl group, and has a molecular weight of less than 200.SELECTED DRAWING: None 【課題】低コストで、かつ安全な手法により、低温かつ短時間で無加圧下吸水倍率と加圧下吸水倍率のバランスに優れ、安全性に問題のない表面架橋された吸水性樹脂（吸水剤）を製造しうる手段を提供する事を目的とする。【解決手段】ポリ（メタ）アクリル酸（塩）系吸水性樹脂を主成分とする吸水剤の製造方法であって、ａ）該吸水性樹脂に、ラジカル重合性単量体及び有機系架橋剤を含む処理液を、吸水性樹脂１００重量部に対して５０重量部以下で混合する工程、及び、ｂ）該ラジカル重合性単量体及び該有機系架橋剤を架橋重合する工程、を含み、該有機系架橋剤が、（メタ）アクリレート基、又は、カルボキシル基と反応しうる官能基、からなる群より選ばれる複数個の官能基を有し、かつ、分子量が２００未満である事を特徴とする吸水剤の製造方法。【選択図】なし