Invention Grant
- Patent Title: Method for producing water-absorbent resin particles and water-absorbent resin particles
- Patent Title (中): 吸水性树脂粒子和吸水性树脂粒子的制造方法
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Application No.: US13878616Application Date: 2010-11-24
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Publication No.: US08951637B2Publication Date: 2015-02-10
- Inventor: Atsushi Heguri , Kenji Tanimura , Yuichi Onoda
- Applicant: Atsushi Heguri , Kenji Tanimura , Yuichi Onoda
- Applicant Address: JP Hyogo
- Assignee: Sumitomo Seika Chemicals Co., Ltd.
- Current Assignee: Sumitomo Seika Chemicals Co., Ltd.
- Current Assignee Address: JP Hyogo
- Agency: Hamre, Schumann, Mueller & Larson, P.C.
- Priority: JP2010-233906 20101018
- International Application: PCT/JP2010/070905 WO 20101124
- International Announcement: WO2012/053121 WO 20120426
- Main IPC: B32B5/16
- IPC: B32B5/16

Abstract:
The present invention provides a method for producing water-absorbent resin particles which show an excellent water absorption rate and high equilibrium swelling capacity and which have an appropriate particle size to be excellent in handleability, and water-absorbent resin particles obtained by the method. The present invention is a method for producing water-absorbent resin particles by reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer, the method including the steps of: (A) first reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon dispersion medium using a water-soluble radical polymerization initiator, in the absence of an internal crosslinking agent and in the presence of a surfactant having an HLB of 8 to 12; (B) intermediate crosslinking reaction by adding an intermediate crosslinking agent; (C) second reversed phase suspension polymerization of a water-soluble ethylenically unsaturated monomer added to the petroleum hydrocarbon dispersion medium containing the surfactant dissolved therein using a water-soluble radical polymerization initiator in the absence of an internal crosslinking agent, thereby producing a water-absorbent resin precursor; and (D) post crosslinking reaction of the water-absorbent resin precursor preliminary adjusted to have a moisture content of 30 to 100% by mass relative to a water-soluble ethylenically unsaturated monomer component in the water-absorbent resin precursor.
Public/Granted literature
- US08900707B2 Method for producing water-absorbent resin particles and water-absorbent resin particles Public/Granted day:2014-12-02
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