PROCESS FOR PRODUCING WATER ABSORBENT RESIN

摘要

The present invention relates to a process for producing water absorbent resin comprising a step of adding a high-molecular crosslinking agent which has at least 2 azetidinium salt groups in the molecule and has at least 1000 weight-average molecular weight to the water absorbent resin paticles having carboxylic groups and carboxylic acid salt groups and a step of efficiently crosslinking the vicinity of the surface of the water absorbent resin particles. In the process for producing water absorbent resin according to the present invention, the use of high-molecular crosslinking agent achieves less permeation of the crosslinking agent into the water absorbent resin particles and enables efficient crosslinking of the vicinitiy of the surface of the water absorbent resin particles. Consequently, the water absorbent resin having high water absorbency both under pressure-free state and under loading can be manufactured. Because the crosslinking agent contains a large amount of azetidinium salt groups highly reactive to carboxylic acid groups or carboxylic acid salt groups in the molecule, the water absorbent resin having high crosslinking efficiency, good safety, and good flowability can be manufactured.