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:
May. 29, 2012
Filed:
Aug. 27, 2008
Makoto Matsumoto, Hyogo, JP;
Toshihiro Takaai, Hyogo, JP;
Yorimichi Dairoku, Okayama, JP;
Shinichi Fujino, Hyogo, JP;
Satoshi Matsumoto, Hyogo, JP;
Seiji Kato, Hyogo, JP;
Makoto Matsumoto, Hyogo, JP;
Toshihiro Takaai, Hyogo, JP;
Yorimichi Dairoku, Okayama, JP;
Shinichi Fujino, Hyogo, JP;
Satoshi Matsumoto, Hyogo, JP;
Seiji Kato, Hyogo, JP;
Nippon Shokubai Co., Ltd., Osaka, JP;
Abstract
A water absorbent resin is dried in a continuous fluidized bed having a heat transfer tube and at least two drying rooms. Pulverization is performed between a first drying room at not less than 80° C. to not more than 200° C. and a second or subsequent room at not less than 100° C. to not more than 220° C. A method for producing a water absorbent resin includes: (1) polymerizing a monomer aqueous solution; (2) drying a hydrogel polymer of step (1); (3) performing particle size control of the dry polymer of the step (2); (5) surface crosslinking the water absorbent resin powder of step (3), and step (4) of performing a second heat drying on the water absorbent resin powder of step (3), preceding step (5). The water absorbent resin has a moisture content of 0 wt % to 3 wt % before the step (5).