POLYACRYLIC ACID (SALT) WATER-ABSORBENT RESIN POWDER, AND METHOD FOR PRODUCING SAME

摘要

Provided is a water-absorbent resin having excellent liquid permeability, water absorption speed, anti-impact stability, and weather resistance. A polyacrylic acid (salt) water-absorbent resin powder in which the water absorbency without pressure (CRC) is 30-45 [g/g], the water absorbency against pressure (AAPO.3) is 20-35 [g/g], the water absorbency against pressure (AAPO.7) is 10-28 [g/g], and the weight-average particle diameter (D50) is 300-500 µm, is characterized by: including p-methoxyphenol; having a degradable solute portion (0.05%L-A(saline) for 2 hours / 60°C, one-hour extraction rinse / room temperature) of 40 wt% or less; and having a closed cell proportion of 0.1-2.5%, as specified by the equation [ (closed cell proportion) % = { (true density) - (apparent density)}/(true density)×100 ].