Patent ID: 7193006

Claim:
A process for continuous production of a water-absorbent resin product, wherein the water-absorbent resin comes being continuously produced via a classification step and a surface-modifying step following a step of polymerizing a monomer and a step of drying, wherein the water-absorbent resin has a mass-average particle diameter of 200 to 700 μm (according to JIS-standardized sieves) after the classification, and contains particles of not smaller than 1,000 μm (according to JIS-standardized sieves) in the range of less than 5.0 mass %, which comprises the following steps of: (A) measuring a water-absorbent resin by its predetermined property and/or its predetermined component content after the classification step and/or a surface-modifying step; (B) separating a predetermined amount of water-absorbent resin (a) from the water-absorbent resin that comes being continuously produced, wherein the water-absorbent resin (a) is a water-absorbent resin which displays not less than a definite value and/or a water-absorbent resin which displays not more than a definite value as to the predetermined property and/or the predetermined component content in accordance with results of the aforementioned measurement; and (C) mixing at least a portion of the aforementioned separated predetermined amount of water-absorbent resin (a) into a water-absorbent resin that comes being continuously produced via a classification step and/or a surface-modifying step on the same or another production line, wherein the water-absorbent resin (a) is mixed without being substantially modified.