Patents Assigned to Nippon Shokubai Kagaku Kabushiki Kaisha
  • Patent number: 5244735
    Abstract: Water-absorbent resins having an average particle diameter of 100 to 600 .mu.m and a particle diameter distribution of 0.35 or less are prepared by polymerizing an aqueous solution of a water-soluble ethylenically unsaturated monomer, pulverizing and sieving the gel-like polymer so obtained, and crosslinking the surface of the polymer powder. In an alternative process, an aqueous solution of the monomer having a viscosity greater than 15 cps is dispersed in a hydrophobic organic solvent and polymerized to obtain a polymer powder, and the surface of the polymer powder is crosslinked.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: September 14, 1993
    Assignee: Nippon Shokubai Kagaku Kabushiki Kaisha
    Inventors: Kazumasa Kimura, Kinya Nagasuna, Takashi Namba, Kenji Kadonaga, Koji Miyake, Tadao Shimomura