Patent Number: 6,254,990

Title: Surface-crosslinking process for water-absorbent resin

Abstract: The present invention provides a surface-crosslinking process of a water-absorbent resin to obtain a water-absorbing agent which has high absorption speed and excellent absorption capacity under a load (a water-absorbent resin which has specific or larger values of properties). In a process comprising the step of adding a crosslinking agent to a dry water-absorbent resin powder to thereby crosslink the neighborhood of its surface, the surface-crosslinking is carried out while the resin powder having a weight-average particle diameter of 200 to 1,000 .mu.m is pulverized.

Inventors: Ishizaki; Kunihiko (Suita, JP), Kanto; Teruyuki (Himeji, JP), Sakamoto; Shigeru (Himeji, JP), Harada; Nobuyuki (Suita, JP), Hitomi; Kazuhisa (Himeji, JP)

Assignee: Nippon Shokubai Co., Ltd.

International Classification: C08J 3/24 (20060101); C08J 3/12 (20060101); C08F 008/14 ()

Expiration Date: 07/03/2018