PARTICULATE WATER ABSORBING AGENT INCLUDING POLYACRYLIC ACID (POLYACRYLATE) BASED WATER ABSORBING RESIN AS A PRINCIPAL COMPONENT, METHOD FOR PRODUCTION THEREOF, WATER-ABSORBENT CORE AND ABSORBING ARTICLE IN WHICH THE PARTICULATE WATER ABSORBING AGENT IS USED

摘要

As a characteristic that had not been known conventionally at all, "permeability potential under pressure (PPUP)" of a particulate water absorbing agent is regulated, and further, "range of particle size distribution" and "coloring" are concomitantly regulated. The present invention is directed to a particulate water absorbing agent having the following (a) to (c): (a) permeability potential under pressure (PPUP) being 50 to 100%; (b) yellowness index (YI) being 0 to 10, and rate of change of yellowness index (DeltaYI) being 100 to 150% following a coloring acceleration test for 14 days at 70±1° C. and the relative humidity of 95±1%; and (c) particles of smaller than 150 mum specified by standard sieve classification accounting for 0 to 5% by weight, weight average particle diameter (D50) being 200 to 550 mum, and logarithmic standard deviation (sigmazeta) of particle size distribution being 0.20 to 0.40.