Patent ID: 9320660
Filing Date: 2016-04-26
CPC Classification: A61F,C08F,C08J,Y10T

Claim Text:
1. A method for producing water-absorbing resin particles, which comprises: preparing a hydrogel polymer by reversed-phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a hydrocarbon solvent in the absence of an internal crosslinking agent but in the presence of a surfactant having an HLB in a range from 8 to 12; and carrying out a post-crosslinking reaction of the hydrogel polymer, whose moisture content has been adjusted so as to form a first-dried gel, to in a range from 30 to 110 mass % relative to a water-soluble ethylenically unsaturated monomer component that forms the hydrogel polymer, wherein a ratio (A:B) is in a range from 99:1 to 70:30, where A is a moisture content (A) of the first-dried gel and B is a moisture amount (B) added with a post-crosslinking agent for the post-crosslinking reaction.