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:
Sep. 15, 2015
Filed:
Jul. 20, 2011
Sachi Kikuno, Kurobe, JP;
Atsushi Heguri, Himeji, JP;
Hideki Yokoyama, Himeji, JP;
Nobuhiro Maeda, Himeji, JP;
Sachi Kikuno, Kurobe, JP;
Atsushi Heguri, Himeji, JP;
Hideki Yokoyama, Himeji, JP;
Nobuhiro Maeda, Himeji, JP;
SUMITOMO SEIKA CHEMICALS CO., LTD., Hyogo, JP;
Abstract
A method for producing a water-absorbent resin comprising at least two stages of reversed-phase suspension polymerization, wherein the first stage of the at least two stages of reversed-phase suspension polymerization comprises the following steps of: (A) performing a primary dispersion by stirring to mix in the absence of surfactants an aqueous solution of a water-soluble ethylenically unsaturated monomer containing a hydrophilic polymeric dispersion agent with a petroleum hydrocarbon dispersion medium in which a hydrophobic polymeric dispersion agent dissolves or disperses; (B) further performing a secondary dispersion by adding a surfactant to the resultant dispersion liquid; and (C) performing a polymerization by using a water-soluble radical polymerization initiator to obtain a water-absorbent resin as particles in a hydrous gel state which disperse in the petroleum hydrocarbon dispersion medium, and a water-absorbent resin obtained by the method.