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. 11, 2010
Filed:
Mar. 12, 2004
Kenya Matsuda, Himeji, JP;
Yuji Kinpara, Himeji, JP;
Tomoki Kawakita, Himeji, JP;
Yasuhiro Nawata, Himeji, JP;
Kenya Matsuda, Himeji, JP;
Yuji Kinpara, Himeji, JP;
Tomoki Kawakita, Himeji, JP;
Yasuhiro Nawata, Himeji, JP;
Sumitomo Seika Chemicals Co., Ltd., Kako-gun, JP;
Abstract
A process for producing a water-absorbent resin particle comprising subjecting a water-soluble ethylenically unsaturated monomer to a reverse phase suspension polymerization, characterized in that the process for producing a water-absorbent resin particle comprises the steps of (A) subjecting the water-soluble ethylenically unsaturated monomer to a first-step reverse phase suspension polymerization in a hydrocarbon-based solvent using a water-soluble radical polymerization initiator in the presence of a surfactant and/or a polymeric protective colloid, and optionally an internal crosslinking agent; (B) carrying out at least one step of the procedures of adding an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a water-soluble radical polymerization initiator and optionally an internal crosslinking agent to a reaction mixture after the termination of the first-step reverse phase suspension polymerization in a state that the surfactant and/or the polymeric protective colloid is dissolved in the hydrocarbon-based solvent, and subsequently subjecting the mixture to a reverse phase suspension polymerization; and (C) post-crosslinking the resulting water-absorbent resin.