	US 12,285,739 B2
	Water absorbent agent and method for producing water absorbent agent
Kazuki Kimura, Himeji (JP); and Reiko Nakatsuru, Himeji (JP)
Assigned to NIPPON SHOKUBAI CO., LTD., Osaka (JP)
Appl. No. 17/421,790
Filed by NIPPON SHOKUBAI CO., LTD., Osaka (JP)
PCT Filed Jan. 10, 2020, PCT No. PCT/JP2020/000645 § 371(c)(1), (2) Date Jul. 9, 2021, PCT Pub. No. WO2020/145383, PCT Pub. Date Jul. 16, 2020.
Claims priority of application No. 2019-003361 (JP), filed on Jan. 11, 2019.
Prior Publication US 2022/0088568 A1, Mar. 24, 2022
Int. Cl. B01J 20/26 (2006.01); B01J 20/28 (2006.01); B01J 20/30 (2006.01)

CPC B01J 20/267 (2013.01) [B01J 20/261 (2013.01); B01J 20/28004 (2013.01); B01J 20/28016 (2013.01); B01J 20/28047 (2013.01); B01J 20/28059 (2013.01); B01J 20/3021 (2013.01); B01J 20/3085 (2013.01); B01J 2220/46 (2013.01)]

15 Claims

1. A method for producing a water absorbent agent comprising:

mixing an inorganic acid alkali metal salt powder with a water-absorbent resin, wherein

a mixing amount of the inorganic acid alkali metal salt powder is not lower than 0.5 parts by mass and not higher than 1 part by mass relative to 100 parts by mass of the water-absorbent resin in an indefinite ground form;

wherein the inorganic acid alkali metal salt powder is at least one type selected from the group consisting of sodium sulfite, sodium bisulfite, sodium sulfate, sodium thiosulfate, sodium carbonate, sodium bicarbonate, sodium phosphate, potassium carbonate, potassium chloride, potassium sulfate, and lithium carbonate; and

the surface of the water absorbent agent is disposed of the inorganic acid alkali metal salt powder, wherein the specific surface area of the water absorbent agent is not lower than 25 m²/kg and proportion of particles of the water-absorbent resin that pass through sieve having mesh opening size of 150 μm to entire water absorbent agent is not higher than 3% by mass.