Title:
METHOD FOR PRODUCING WATER-ABSORBING RESIN, WATER-ABSORBING RESIN, ABSORBER, AND ABSORBENT ARTICLE
Document Type and Number:
WIPO Patent Application WO/2022/255300
Kind Code:
A1
Abstract:
Provided is a method for producing a water-absorbing resin having increased water holding capacity, water absorption capacity under load, and DW without pressure. This method for producing a water-absorbing resin produces the same by subjecting a water-soluble ethylenically unsaturated monomer to reverse phase suspension polymerization in a hydrocarbon dispersion medium, the method including: a polymerization step for mixing an aqueous solution containing the water-soluble ethylenically unsaturated monomer, the hydrocarbon dispersion medium, a polymerization initiator, a dispersion stabilizer and an internal crosslinking agent; and a post-crosslinking step in which the polymer obtained in the polymerization step is post-crosslinked. The polymerization initiator includes an azo compound and a peroxide. The water-soluble ethylenically unsaturated monomer contains 70-100 mol% of acrylic acid and salts thereof. The concentration of the water-soluble ethylenically unsaturated monomer in the aqueous solution containing the water-soluble ethylenically unsaturated monomer is 40 mass% or more. The molar ratio of the internal crosslinking agent relative to the azo compound (internal crosslinking agent/azo compound) is 0.05-0.10.
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Inventors:
KOGURE NAOKI (JP)
Application Number:
PCT/JP2022/021925
Publication Date:
December 08, 2022
Filing Date:
May 30, 2022
Export Citation:
Assignee:
SUMITOMO SEIKA CHEMICALS (JP)
International Classes:
C08F20/06; A61F13/15; A61F13/53; B01J20/26; C08F2/18
Domestic Patent References:
| WO2020122219A1 | 2020-06-18 | |||
| WO2008126793A1 | 2008-10-23 | |||
| WO2019074099A1 | 2019-04-18 |
Foreign References:
| JP2020121093A | 2020-08-13 | |||
| JP2007099845A | 2007-04-19 | |||
| JPH03227301A | 1991-10-08 |
Attorney, Agent or Firm:
TANAKA, Junya et al. (JP)
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