Patent ID: 8975339
Filing Date: 2015-03-10
Classification: C08J

Abstract:
1. A surface-treated water-absorbent resin obtained by a method comprising: a) a step for mixing 0.1 to 20 parts by weight of an acid group-containing radically polymerizable compound and 5 to 20 parts by weight of water, relative to 100 parts by weight of a water-absorbent resin; and b) a step for polymerizing the acid group-containing radically polymerizable compound, wherein neutralization ratio of the acid group-containing radically polymerizable compound is 0 to 60% by mol, and is lower than neutralization ratio of the water-absorbent resin; wherein residual amount of monomer is in the range of 0 to 300 ppm by weight; wherein said surface-treated water-absorbent resin has a sodium atom width as determined by electron probe micro analysis (EPMA) in the range of 5 to 50 μm; and wherein the numerical value ratio of the neutralization ratio of the acid group-containing radically polymerizable compound relative to the neutralization ratio of the water-absorbent resin is in the range of 0 to 80%.