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:
Jan. 24, 2017
Filed:
Nov. 27, 2013
Nippon Shokubai Co., Ltd., Osaka, JP;
Satoshi Matsumoto, Himeji, JP;
Makoto Matsumoto, Himeji, JP;
Seiji Kato, Himeji, JP;
Kazumasa Konishi, Himeji, JP;
Kenji Kadonaga, Himeji, JP;
Shinichi Fujino, Himeji, JP;
Nippon Shokubai Co., Ltd., Osaka-shi, JP;
Abstract
An object of the present invention is to provide a simple method for improving and stabilizing the physical properties (for example, liquid permeability) of a water absorbent resin, without requiring investment in expensive facilities or modification of raw materials. In particular, the object is to provide a method which is useful in the large-scale production of a water absorbent resin. The method for producing polyacrylic acid (salt)-based water absorbent resin of the present invention includes, in order, a step in which an acrylic acid (salt)-based monomer aqueous solution is polymerized, a step in which the water-containing gel-like crosslinked polymer obtained in the polymerization step is dried, a step in which the dried polymer obtained in the drying step is pulverized, and a classification step which takes place after the drying step or after the pulverizing step, wherein, at the time of providing the dried polymer to the roll mill used in the pulverizing step, the dried polymer is provided in a dispersed state in the axial direction of the roll of the roll mill.