The method of manufacturing a surface treatment method and a water-absorbent resin of the water-absorbent resin

The present invention, physical properties by finding the appropriate conditions of the pretreatment step in the surface treatment step of the water-absorbing resin to provide a method for producing stable and superior surface-crosslinked water-absorbent resin. Surface treatment process for a water-absorbent resin of the present invention, 1) by mixing the base polymer and the surface-crosslinking agent solution, humidification mixing step to obtain a "humidified substance"; the temperature was raised in 2) humidifier was pretreatment step to obtain the "pretreated substance", and; and 3) crosslinking the pretreatment material, the surface cross-linking reaction to obtain a is surface crosslinked "water absorbent resin" includes three steps, water absorption a surface treatment method of the resin, the 2) or less 95 ° C. dew point is 50 ° C. or higher in the pretreatment step, and the temperature of the humidifier was elevated from a temperature below the dew point up to dew point + 10 ° C. wherein the temperature of the.