Patent ID: 7851550

Claim:
A method for manufacturing water-absorbing resin, comprising: a modifying step that is a step of heating a mixture of a hydrophilic crosslinked polymer containing a carboxyl group and an aqueous solution containing a surface crosslinking agent containing two or more functional groups which react with the carboxyl group, so as to crosslink a surface of the hydrophilic crosslinked polymer; and a cooling step of cooling down the hydrophilic crosslinked polymer thus surface crosslinked, at least one of the modifying step and the cooling step being carried out by using a stirring device including a rotation axis and including a plurality of stirring boards, wherein a direction parallel to a longitudinal direction of the rotation axis is a y direction, a direction that is perpendicular to the y direction and is parallel to a circumferential direction of the rotation axis is an x direction, and a direction perpendicular to the x direction and the y direction is a z direction, a ratio of a maximum thickness of the stirring board to a minimum thickness of the stirring board being 5 or less in a cross section taken along a y-z plane of the stirring device, wherein the stirring board is in a disc shape or a disc shape a part of which is lacking.