The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 10, 2003
Filed:
Feb. 22, 2001
Kunihiko Ishizaki, Suita, JP;
Teruyuki Kanto, Himeji, JP;
Nobuyuki Harada, Suita, JP;
Takumi Hatsuda, Takasago, JP;
Shinichi Fujino, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
The present invention provides a production process for a water-absorbent resin powder which is excellent in particle diameter distribution and properties, wherein the production process not only inhibits adhesion and aggregation in the production steps, but also is excellent in energy efficiency, drying efficiency, and productivity. The production process for a water-absorbent resin powder comprises the steps of: polymerizing an aqueous monomer solution containing a crosslinking agent; heat-drying the resultant crosslinked hydrogel polymer; and pulverizing the resultant dry polymer; wherein: the dry polymer resultant from the heat-drying step is forcibly cooled before or during the pulverization step; and the water-absorbent resin powder has an average particle diameter of 200 to 600 &mgr;m after the pulverization step wherein the total ratio of particles having particle diameters of not larger than 150 &mgr;m and particles having particle diameters of not smaller than 850 &mgr;m in the water-absorbent resin powder is not more than 15 weight % of the water-absorbent resin powder.