Patents by Inventor Michiharu Harakawa

Michiharu Harakawa 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: 5968435
    Abstract: In a step of spinning a molten mesophase pitch in a process for manufacturing a pitch-type carbon fiber, the pitch is allowed to pass through an orifice and to be contracted once, is then expanded in an introduction port with a diameter greater than that of the orifice, and is then allowed to pass through an outlet pore formed at a collecting portion to spin the pitch. The pitch-type carbon fiber has a high elastic modulus in tension and high compressive strength.
    Type: Grant
    Filed: April 23, 1998
    Date of Patent: October 19, 1999
    Assignees: Nippon Steel Corporation, Nippon Steel Chemical Co., Ltd, Nippon Graphite Fiber Corporation
    Inventors: Osamu Kato, Yoshio Kishimoto, Yutaka Arai, Hajime Nakajima, Masatoshi Furuyama, Tsutomu Kihara, Michiharu Harakawa, Shigeo Hara, Ken Kobayashi, Yoshiyuki Doken, Tsutomu Nakamura
  • Patent number: 4717331
    Abstract: A melt-spinning nozzle in which is disposed an elongated molded piece so as to form a space serving as a melt flow path between the elongated molded piece and the inner wall of the nozzle.
    Type: Grant
    Filed: May 30, 1985
    Date of Patent: January 5, 1988
    Assignee: Nippon Oil Company Limited
    Inventors: Naoyuki Maeda, Osamu Kato, Hirosaku Oshimi, Akira Nii, Hiroshi Shimada, Michiharu Harakawa, Takuji Hirano, Shigeo Hara
  • Patent number: 4579645
    Abstract: Provided is a starting pitch for producing carbon fiber by heat-treating the starting pitch to obtain a precursor pitch, melt-spinning the precursor pitch, then rendering the resultant pitch fiber infusible, followed by carbonization, and further followed by graphitization if required, the starting pitch comprising a mixture of (a) 100 parts by weight of a pitch and (b) 5 to 500 parts by weight of a methanol-insoluble and benzene-soluble component contained in a heavy oil obtained in a fluid catalytic cracking of petroleum, the heavy oil having a boiling range not lower than 200.degree. C.
    Type: Grant
    Filed: April 12, 1983
    Date of Patent: April 1, 1986
    Assignee: Nippon Oil Company, Limited
    Inventors: Seiichi Uemura, Hiroaki Takashima, Osamu Kato, Michiharu Harakawa