Patents by Inventor Shoyo Takagi

Shoyo Takagi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4794152
    Abstract: A bead-like glycidyl (meth)acrylate polymer is produced by aqueous suspension polymerization of glycidyl (meth)acrylate alone or a monomer mixture composed of more than 50 weight % of said monomer and at least one other monomer which forms the remainder, in the presence of a specific aqueous polymer, at a pH of from 2 to 9 and at a stirring speed of from 50 to 500 r.p.m. By heat treating said bead-like polymer at a pH below 3 and at a temperature above 70.degree. C., hydroxyl groups resulting from the ring opening of the epoxy groups are introduced, whereby a solvent-insoluble bead-like polymer having a gel water content not less than 30% is produced.
    Type: Grant
    Filed: February 4, 1986
    Date of Patent: December 27, 1988
    Assignee: Japan Exlan Company Limited
    Inventors: Toshiyuki Kobashi, Hideo Naka, Shoyo Takagi
  • Patent number: 4565832
    Abstract: The present invention relates to a process for producing a packing material for use in liquid chromatography which comprises aqueous suspension polymerizing vinyl acetate, a (meth)acrylic acid ester or a glycidyl monovinyl ester or ether with a monomer mixture composed mainly of a cross-linking monomer in the presence of a diluent selected from among epichlorohydrin and glycidyl ethers and thereafter removing it from the resulting polymer particles by ring-opening the epoxy groups in said diluent. This process provides a packing material for use in liquid chromatography which is uniform and porous and moreover is excellent in mechanical strength.
    Type: Grant
    Filed: November 30, 1984
    Date of Patent: January 21, 1986
    Assignee: Japan Exlan Company Limited
    Inventors: Toshiyuki Kobashi, Shoyo Takagi, Hideo Naka
  • Patent number: 4540754
    Abstract: In the suspension polymerization of acrylonitrile in an aqueous medium, the polymerization is conducted in the presence of a water-soluble polymer and an oil soluble radical initiator while maintaining the acrylonitrile concentration higher than 9 weight percent in the polymerization system, whereby the polymerization of acrylonitrile in the water phase is suppressed and a high molecular weight polymer (weight average molecular weight not less than 400,000) having uniform particle diameters is produced.
    Type: Grant
    Filed: March 26, 1984
    Date of Patent: September 10, 1985
    Assignee: Japan Exlan Company Limited
    Inventors: Toshiyuki Kobashi, Shoyo Takagi