Water-absorbent resin powder and production process therefor

摘要

The present invention provides a production process for a water-absorbent resin powder which is excellent in particle diameter distribution and properties, wherein the production process not only inhibits adhesion and aggregation in the production steps, but also is excellent in energy efficiency, drying efficiency, and productivity. The production process for a water-absorbent resin powder comprises the steps of: polymerizing an aqueous monomer solution containing a crosslinking agent; heat-drying the resultant crosslinked hydrogel polymer; and pulverizing the resultant dry polymer; wherein: the dry polymer resultant from the heat-drying step is forcibly cooled before or during the pulverization step; and the water-absorbent resin powder has an average particle diameter of 200 to 600 mum after the pulverization step wherein the total ratio of particles having particle diameters of not larger than 150 mum and particles having particle diameters of not smaller than 850 mum in the water-absorbent resin powder is not more than 15 weight % of the water-absorbent resin powder.