Patents by Inventor Isao Hamana

Isao Hamana 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).

  • Novel naphthalate polyester fibers, and their end uses
    Patent number: 4001479
    Abstract: A filament, fiber and yarn consisting of a naphthalate polyester containing at least 85 mol % of ethylene-2,6-naphthalate units and having an intrinsic viscosity of 0.3 to 1.0, said filament, fiber and yarn having a diffraction intensity ratio (R) between a Bragg reflection angle 2.THETA. = 18.7.degree. and 2.THETA. = 15.6.degree., as determined by the X-ray diffraction method, being in the range of 0.15 to 1.73.Electrically insulating material can be produced by heat-treating a fabric consisting mainly of the above naphthalate polyester fibers.
    Type: Grant
    Filed: September 18, 1975
    Date of Patent: January 4, 1977
    Assignee: Teijin Limited
    Inventors: Isao Hamana, Yoshio Fujiwara, Shiro Kumakawa
  • Process for spinning naphthalate polyester fibers
    Patent number: 4000239
    Abstract: A filament, fiber or yarn consisting of a naphthalate polyester containing at least 85 mol % of ethylene-2,6-naphthalate units and having an intrinsic viscosity of 0.45 to 1.0, said filament, fiber or yarn having a diffrection intensity ratio (R) between a bragg refection angle 2.theta. = 187.7.degree. and 2.theta. = 15.6.degree., as determined by the X-ray diffraction method, being in the range of more than 1.73 and up to 5.00.Electrically insulating material can be produced by heat-treating a fabric consisting mainly of the above naphthalate polyester fibers and with a sleeve consisting mainly of the above naphthalate polyester fibers.
    Type: Grant
    Filed: November 30, 1973
    Date of Patent: December 28, 1976
    Assignee: Teijin Limited
    Inventors: Isao Hamana, Yoshio Fuziwara, Shiro Kumakawa
  • Conjugate fiber, fibrous material and fibrous article made therefrom and process for production thereof
    Patent number: 3998988
    Abstract: A conjugate fiber of a thermoplastic synthetic organic polymer composed of a high melting polymer component and a low melting polymer component, said low melting polymer component having a melting point at least 40.degree. C. lower than that of the high melting polymer component, and having adhered to its surface finely divided particles of an adsorbent. The fiber is a good filter having reduced pressure loss and increased adsorbing power. Fibrous materials and articles are made from these conjugate fibers.
    Type: Grant
    Filed: July 11, 1975
    Date of Patent: December 21, 1976
    Assignee: Teijin Limited
    Inventors: Akiro Shimomai, Iwao Fujimoto, Isao Hamana, Kiyoji Katayama
  • Draw-texturing polyester yarns
    Patent number: 3977175
    Abstract: Textured polyester yarn is prepared from multifilament yarn composed of a synthetic linear ethylene terephthalate polyester by draw-texturing at a draw ratio of 1.05 - 1.30X, using a heat-setting temperature of about 170.degree. - 240.degree.. Feed yarn for said draw-texturing process has (a) a break elongation of 40 - 80%, (b) a density of above 1.371 g/cm.sup.3, and (c) a boil-off shrinkage of less than 8%. Said feed yarn is prepared by modified melt spinning of the foregoing polyester at a speed of about 3000 - 5000 meters per minute.
    Type: Grant
    Filed: December 9, 1974
    Date of Patent: August 31, 1976
    Assignee: Teijin Limited
    Inventors: Hirofumi Yoshikawa, Isao Hamana, Shiro Kumakawa