| abstract |
[PROBLEMS] To provide a white water-absorbing resin having an improved water-absorbing speed without maintaining or greatly impairing other physical properties of the water-absorbing resin (liquid permeability, bulk specific gravity, surface tension, water absorption capacity under pressure, impact resistance, etc.). provide. A method for producing a polyacrylic acid-based water-absorbing resin powder according to the present invention comprises a step of polymerizing an aqueous solution of an acrylic acid-based monomer containing bubbles, and a hydrogel crosslinked polymer obtained in the polymerization step. A step of drying the coalesced solution, and reducing the solubility of the dissolved gas in the aqueous monomer solution in the presence of a surfactant and / or a dispersant, thereby generating bubbles in the aqueous acrylic acid monomer solution. A bubble generation containing step is included. [Selection] Figure 13 |