METHOD FOR MANUFACTURING POLYACRYLIC ACID (SALT)-BASED WATER-ABSORBING RESIN POWDER AND POLYACRYLIC ACID (SALT)-BASED WATER-ABSORBING RESIN POWDER

摘要

PROBLEM TO BE SOLVED: To provide a water-absorbing resin and a composition which have improved liquid permeability with a status of maintaining water absorption speed.SOLUTION: There is provided a polyacrylic acid (salt)-based water-absorbing resin having 95 wt.% or more of particles with a particle diameter of 150 to 850 μm of and a logarithmic standard deviation of a particle size distribution (&sgr;ζ) of 0.25 to 0.50 and water absorption magnification under pressure of 20 [g/g] or more, water absorption speed of 0.30 [g/g/s] or more and an inner bubble fraction defined by the following formula of 0.1 to 2.5%. (inner bubble fraction)[%]=[(true density)-(apparent density)]/(true density)×100.