Patents by Inventor Okihiko Hirasa

Okihiko Hirasa 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).

  • Porous hydrophilic polypropylene membrane, method for production thereof, and blood plasma separation apparatus
    Patent number: 5186835
    Abstract: A porous hydrophilic polypropylene membrane possessing a fine reticular structure, which is characterized by the fact that at least either of the opposite surfaces of membrane forms a surface layer of a reticular structure substantially equal to that in the interior of membrane, the membrane surfaces and the surfaces of pores in the membrane have a hydrophilic polymer chemically bonded thereto, and the membrane is composed substantially of a polypropylene possessing an average pore diameter in the range 0.1 to 2.0 .mu.m, a bubble point of not more than 2.0 kg/cm.sup.2, a porosity in the range of 60 to 85%, and a water permeability of not less than 2 ml/min.mmHgm.sup.2, a method for the production thereof, and a blood plasma separation apparatus incorporating such membranes in a housing are disclosed.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: February 16, 1993
    Assignees: Agency of Industrial Science and Technology, Terumo Kabushiki Kaisha
    Inventors: Toshio Masuoka, Okihiko Hirasa, Makoto Onishi, Yukio Seita
  • N-(2-methoxyethyl)-N-isopropylacrylamide, hydrophilic-hydrophobic thermally reversible macromolecular compound, method for production thereof, and thermally reversible macromolecular composition
    Patent number: 5162582
    Abstract: N-(2-methoxyethyl)-N-isopropylacrylamide is a novel compound. The polymer obtained by polymerizing this novel compound is a novel hydrophilic-hydrophobic thermally reversible type macromolecular compound having a transition temperature in the range of 12.degree. C. to 14.degree. C.
    Type: Grant
    Filed: January 31, 1990
    Date of Patent: November 10, 1992
    Assignees: Agency of Industrial Science and Technology, Minstry of International Trade and Industry
    Inventors: Shoji Ito, Okihiko Hirasa, Shoei Fujishige, Aizo Yamauchi
  • Hydrophilic porous membrane, method for production thereof, and plasma separator using said membrane
    Patent number: 4845132
    Abstract: A hydrophilic porous membrane has graft chains of a hydrophilic monomer formed on the surface of a hydrophobic porous membrane so as to impart to the surface perfect hydrophilicity such that the produced membrane, when wetted, exhibits a swelling ratio of not more than 1% and a bubble point in the range of 0.5 to 8 kg/cm.sup.2. The hydrophilic porous membrane is produced by irradiating the hydrophobic porous membrane with plasma, feeding the hydrophilic monomer in a gaseous state, and allowing the hydrophilic monomer to be graft polymerized on the surface of the porous membrane. A plasma separator is obtained by using the aforementioned hydrophilic porous membrane as a plasma separation membrane.
    Type: Grant
    Filed: May 6, 1987
    Date of Patent: July 4, 1989
    Assignees: Agency of Industrial Science and Technology, Terumo Kabushiki Kaisha
    Inventors: Toshio Masuoka, Okihiko Hirasa, Yoshio Suda, Makoto Onishi, Yukio Seita