Patents by Inventor Toyohiro Maeda

Toyohiro Maeda 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).

  • Process for treating coal tar or coal tar pitch
    Patent number: 4986895
    Abstract: Pitch substantially free from primary and secondary QI components and solids comprising secondary QI components are prepared by centrifuging coal tar or coal tar pitch at a high temperature, heat-treating the separated supernatant liquid and centrifuging again the liquid at a high temperature.
    Type: Grant
    Filed: September 5, 1989
    Date of Patent: January 22, 1991
    Assignee: Osaka Gas Company Limited
    Inventors: Makihiko Mori, Katsumi Fujita, Yoshiteru Nakagawa, Yasunori Goda, Toyohiro Maeda
  • Process for preparing carbon fibers elliptical in section
    Patent number: 4859382
    Abstract: A process for preparing a carbon fiber having an elliptical cross section, characterized by the steps of extruding spinnable pitch from a nozzle with an orifice rectangular or otherwise shaped in cross section and having a width/height ratio of more than 1, fully relaxing the molecules orientated by the nozzle on discharge from the nozzle, effecting continuous winding-up to obtain a pitch fiber elliptical in cross section, rendering the fiber infusible and carbonizing the same.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: August 22, 1989
    Assignees: Osaka Gas Company Limited, Dainippon Ink and Chemicals Inc.
    Inventors: Kazutoshi Haraguchi, Eiji Tanigawa, Kenji Nukina, Hiroaki Morita, Toyohiro Maeda
  • Process for preparing pitch
    Patent number: 4640761
    Abstract: Pitch free from quinoline insoluble components is prepared by heat-treating coal tar or coal tar pitch in the absence or in the presence of carbonaceous particles and centrifuging at a high temperature the reaction product resulting from the heat treatment or a mixture of the reaction product from the heat treatment and coal tar-type light or middle oil.
    Type: Grant
    Filed: April 17, 1984
    Date of Patent: February 3, 1987
    Assignee: Osaka Gas Company Limited
    Inventors: Makihiko Mori, Satoshi Kibe, Toyohiro Maeda