Invention Grant
- Patent Title: Polyacrylic acid (salt)-based water absorbent resin, and method for production thereof
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Application No.: US13994871Application Date: 2011-12-16
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Publication No.: US09962680B2Publication Date: 2018-05-08
- Inventor: Satoshi Matsumoto , Kunihiko Ishizaki , Kanako Tsuru
- Applicant: Satoshi Matsumoto , Kunihiko Ishizaki , Kanako Tsuru
- Applicant Address: JP Osaka
- Assignee: Nippon Shokubai Co., Ltd.
- Current Assignee: Nippon Shokubai Co., Ltd.
- Current Assignee Address: JP Osaka
- Agency: Cesari and McKenna, LLP
- Priority: JP2010-281382 20101217
- International Application: PCT/JP2011/079219 WO 20111216
- International Announcement: WO2012/081702 WO 20120621
- Main IPC: B01J20/26
- IPC: B01J20/26 ; B01J20/28 ; B01J20/30 ; A61L15/60 ; C08F220/06 ; C08F222/10

Abstract:
Provided is a method for producing a polyacrylic acid (salt)-based water absorbent resin, which is a convenient production method for a water absorbent resin for an absorbent suitable for practical use, the water absorbent resin having a reduced amount of residual monomers. Disclosed is a method for producing a polyacrylic acid (salt)-based water absorbent resin, the method comprising a polymerization step of polymerizing an aqueous monomer solution containing acrylic acid (salt) as a main component; a drying step of drying a water-containing gel-like crosslinked polymer obtained in the polymerization step; a surface crosslinking step of surface crosslinking the water absorbent resin under drying or the water absorbent resin which has been dried; and a packaging step of packaging the surface crosslinked water absorbent resin, wherein an iron content in the aqueous monomer solution in the polymerization step is 2 ppm (relative to the monomer(s)) or less, a moisture content of the water absorbent resin in the packaging step is 1% by weight or more, and the method further comprises, after the packaging step, a storage step of storing the packaged water absorbent resin for 3 days or longer.
Public/Granted literature
- US20130264517A1 POLYACRYLIC ACID (SALT)-BASED WATER ABSORBENT RESIN, AND METHOD FOR PRODUCTION THEREOF Public/Granted day:2013-10-10
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