Title:
PROCESS FOR PRODUCTION OF WATER-ABSORBABLE RESIN PARTICLE, AND WATER-ABSORBABLE RESIN PARTICLE PRODUCED BY THE PROCESS
Document Type and Number:
WIPO Patent Application WO/2007/123188
Kind Code:
A1
Abstract:
Disclosed is a process for production of a water-absorbable resin particle, which comprises the following steps (1) to (3): (1) performing the first stage of the reverse phase suspension polymerization of a water-soluble ethylenically unsaturated monomer in a petroleum hydrocarbon solvent in the presence of a dispersion stabilizer to yield a spherical primary particle having a median particle diameter (d) of 30 to 130 μm; (2) cooling the polymerization reaction solution to cause the precipitation of the dispersion stabilizer; and (3) adding a second-stage water-soluble ethylenically unsaturated monomer to the polymerization reaction solution and performing the second stage of the reverse phase suspension polymerization to cause the aggregation of the primary particle, thereby forming a secondary particle having a median particle diameter (D) of 200 to 500 μm, wherein the median particle diameter (d) of the primary particle and the median particle diameter (D) of the secondary particle has the relationship shown by the following formula: 5d/3+150 < D < 5d+150.
Inventors:
HANDA, Masayoshi (())
半田 昌良 (())
半田 昌良 (())
Application Number:
JP2007/058579
Publication Date:
November 01, 2007
Filing Date:
April 20, 2007
Export Citation:
Assignee:
SUMITOMO SEIKA CHEMICALS CO., LTD. (346-1, Miyanishi Harima-cho, Kako-gu, Hyogo 45, 6750145, JP)
住友精化株式会社 (〒45 兵庫県加古郡播磨町宮西３４６番地の１ Hyogo, 6750145, JP)
HANDA, Masayoshi (())
住友精化株式会社 (〒45 兵庫県加古郡播磨町宮西３４６番地の１ Hyogo, 6750145, JP)
HANDA, Masayoshi (())
International Classes:
C08F2/18; B01J20/26; C08F20/06
Attorney, Agent or Firm:
HOSODA, Yoshinori (P.O. Box 26 OMM Building 5th Floor, 7-31, Otemae 1-chome, Chuo-ku, Osaka-sh, Osaka 91, 5406591, JP)
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