Patent ID: 6716894
Filing Date: 2004-04-06
Classification: B01J,C08J,Y10S,Y10T

Abstract:
A production process for a water-absorbent resin powder, which comprises the steps of: polymerizing an unsaturated monomer; and drying the resultant crosslinked hydrogel polymer, wherein the water-absorbent resin powder has a crosslinked structure and a mass-average particle diameter of 300 to 600 &mgr;m wherein the ratio of fine particles having particle diameters of not larger than 150 &mgr;m is less than 10 mass % of the water-absorbent resin powder,with the production process being characterized by further comprising a magnetic-flux irradiation step of passing a magnetic field having a magnetic flux density of not less than 0.05 Wb/m2 through the water-absorbent resin powder after the drying step in the production process.