Patent ID: 7510988

Claim:
A particulate water-absorbing agent containing a particulate polycarboxylic acid water-absorbent resin surface-cross-linked by a surface-cross-linking agent which forms ester bond with a carboxyl group, the particulate water-absorbing agent satisfying following conditions: (a) a centrifuge retention capacity (CRC) for a physiological saline solution being not less than 27 g/g; (b) an absorbency against pressure (AAP) of 4.8 kPa for the physiological saline solution being not less than 20 g/g; (c) a mass average particle diameter (D50) being 200-450 Î¼m; (d) an amount of particles smaller than 150 Î¼m in the particulate water-absorbing agent being 0-5% by mass; (e) a logarithmic standard deviation (ÏƒÎ¶) of particle size distribution being 0.20-0.40; and (f) a content of an alcohol volatile substance evaporated from the particulate water-absorbing agent being 0-10 ppm, the content being measured by a gas detecting tube as an atmosphere concentration.