Patents by Inventor Tohru Iwahashi

Tohru Iwahashi 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: 5066384
    Abstract: A process for refining coal-derived heavy carbonaceous materials such as pitch to remove quinline insolubles therefrom is disclosed. The process comprises providing a coal-derived heavy carbonaceous material from which all the components having normal boiling points of 270.degree. C. or below and all or part of the components having normal boiling points ranging from 270.degree. C. to 360.degree. C. have been removed; heating the heavy carbonaceous material to make it fluid; mixing the heated carbonaceous material with a ketone solvent having a boiling point below 200.degree. C. for a period sufficient to precipitate coarse insoluble particles in the mixture; separating the precipitated particles from the mixture; and removing the ketone solvent from the mixture, leaving a refined, coal-derived heavy carbonaceous material which is suitable for use in the production of high-grade carbon stocks such as needle coke, carbon fibers, high-purity carbon, etc., and for use as an impregnant or binder pitch.
    Type: Grant
    Filed: February 29, 1988
    Date of Patent: November 19, 1991
    Assignees: Sumitomo Metal Industries, Ltd., Sumikin Chemical Co. Ltd., Kureha Kagaku Kogyo Kabushiki Kaisha
    Inventors: Tohru Iwahashi, Yoshihiko Sunami, Katsumi Satoh, Katsuyuki Ohshima, Kenichi Iwaguro
  • Patent number: 4671907
    Abstract: A method for the manufacture of high-strength, high-density carbon materials is disclosed. The method comprises the steps of pulverizing a carbonaceous raw material having a carbon content of at least 92% by weight, a volatile content of 7-20% by weight up to 900.degree. C., and linear shrinkage as a molded body of at most 6% during heating up to 500.degree. C. to an average particle diameter of greater than 10 .mu.m and at most 40 .mu.m, followed by molding and baking. An organic fiber after baking in an inert atmosphere at a temperature of at least 400.degree. C. may be mixed with the pulverized carbonaceous raw material.
    Type: Grant
    Filed: August 6, 1985
    Date of Patent: June 9, 1987
    Assignee: Sumitomo Metal Industries, Inc.
    Inventors: Tohru Iwahashi, Yoshihiko Sunami, Tadashi Miyamura
  • Patent number: 4402824
    Abstract: A coal-based heavy oil is refined so as to remove quinoline insolubles and provide a hydrocarbon product suitable for making carbon stocks by heating to remove the volatile components which have boiling points ranging from the initial boiling point of the heavy oil to up to at least 200.degree. C. and at most 270.degree. C., thereby leaving a residual coal-based heavy oil, the residual coal-based heavy oil is mixed with a ketone-type solvent having a boiling point less than 200.degree. C. to form an insoluble precipitate (including quinoline insolubles) and a supernatent, the supernatent is treated to recover the ketone-type solvent, and the remaining hydrocarbon mixture is easily processed by vacuum distillation to produce a hydrocarbon product suitable for making carbon stocks.
    Type: Grant
    Filed: March 25, 1981
    Date of Patent: September 6, 1983
    Assignee: Sumitomo Metal Industries, Limited
    Inventors: Yoshihiko Sunami, Keiichi Sasaki, Tohru Iwahashi