| 摘要 |
<p>The present invention provides a method for producing a water-absorbent resin comprising at least two stages of reversed-phase suspension polymerization, wherein an odor originated from a raw material component, in particular, a petroleum hydrocarbon dispersion medium, is further reduced as compared with a water-absorbent resin obtained by a conventional method, and a water-absorbent resin obtained by the method. More specifically, the present invention provides 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.</p> |
