Patents by Inventor Toshihiko Yokoyama

Toshihiko Yokoyama 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: 4455179
    Abstract: The invention provides a novel magnetically traceable or detectable explosive blended with a magnetic ferrite powder which facilitates the detection of the misfired explosive, e.g. dynamite, remaining in the field after blasting by a magnetic means but not to adversely affect the stability of the explosive. The ferrite powder is freed of any free alkalinity on the surface before blending with the explosive either by washing with water, neutralization with a dilute acid, reaction with an acid followed by washing with water or neutralization with an alkali and/or by coating with a polymeric material on the particles. The most efficient method for the coating of the ferrite powder with a polymeric material is the in situ polymerization of a radical-polymerizable monomer in contact with the ferrite particles in the presence of hydrogensulfite ions and the explosives blended with such a polymer-coated ferrite powder retain their stability even after a prolonged storage.
    Type: Grant
    Filed: October 26, 1981
    Date of Patent: June 19, 1984
    Assignees: Tohoku Metal Industries, Ltd., Taisei Corporation
    Inventors: Tadashi Yamaguchi, Takayuki Ono, Michitoshi Hirata, Toshihiko Yokoyama
  • Patent number: 4202990
    Abstract: An ester of an unsaturated carboxylic acid is prepared by an ester exchange process which comprises reacting a lower alkyl ester of an unsaturated, 3-4 carbon atom carboxylic acid with a higher alcohol than the alcohol fragment of said lower alkyl ester over a catalyst selected from the group consisting of (1) chelate compounds of zirconium with .beta.-diketone or mixtures thereof, (2) chelate compounds of calcium with .beta.-diketone or mixtures thereof, and mixtures thereof by an ester exchange reaction.
    Type: Grant
    Filed: January 27, 1978
    Date of Patent: May 13, 1980
    Assignee: Mitsubishi Rayon Company, Limited
    Inventors: Fumiki Murakami, Soichi Teshima, Toshihiko Yokoyama
  • Patent number: 4074062
    Abstract: An ester of an unsaturated carboxylic acid is prepared by an ester exchange process which comprises reacting a lower alkyl ester of an unsaturated, 3-4 carbon atom carboxylic acid with an alcohol different than the alcohol fragment of said lower alkyl ester over a catalyst selected from the group consisting of (1) metallic barium, barium compounds and mixtures thereof, (2) metallic thallium, thallium compounds or mixtures thereof, (3) metallic molybdenum, molybdenum compounds or mixtures thereof, and mixtures thereof by an ester exchange reaction.
    Type: Grant
    Filed: July 7, 1976
    Date of Patent: February 14, 1978
    Assignee: Mitsubishi Rayon Company, Limited
    Inventors: Fumiki Murakami, Soichi Teshima, Toshihiko Yokoyama