Patents by Inventor Yoshihito Sema

Yoshihito Sema 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).

  • Method of producing magnetic carbon black
    Patent number: 4995999
    Abstract: Magnetic carbon black, a process for preparing the same, and a method of modifying magnetic carbon black are provided. The magnetic carbon black is prepared by process A in which when a hydrocarbon is supplied into a high temperature combustion gas stream formed by combustion of a fuel to prepare carbon black, an organic transition metal compound is supplied together with the hydrocarbon and, at the same time, an oxygen gas is supplied from the circumference of the hydrocarbon, process B in which a transition metal compound is supplied together with a hydrogen gas on the downstream side of the supply position of the hydrocarbon, and process C in which a hydrocarbon is supplied into a high temperature combustion gas stream on both the upstream side and the downstream side and a transition metal compound is supplied from a position between the supply positions of the hydrocarbon.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: February 26, 1991
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Yoshihito Sema, Kazuhito Kataoka
  • Process for preparing magnetic carbon black
    Patent number: 4900465
    Abstract: Magnetic carbon black, a process for preparing the same, and a method of modifying magnetic carbon black are provided. The magnetic carbon black is prepared by process A in which when a hydrocarbon is supplied into a high temperature combustion gas stream formed by combustion of a fuel to prepare carbon black, an organic transition metal compound is supplied together with the hydrocarbon and, at the same time, an oxygen gas is supplied from the circumference of the hydrocarbon, process B in which a transition metal compound is supplied together with a hydrogen gas on the downstream side of the supply position of the hydrocarbon, and process C in which a hydrocarbon is supplied into a high temperature combustion gas stream on both the upstream side and the downstream side and a transition metal compound is supplied from a position between the supply positions of the hydrocarbon.
    Type: Grant
    Filed: February 10, 1988
    Date of Patent: February 13, 1990
    Assignee: Tokai Carbon Co., Ltd.
    Inventors: Toshio Nakada, Fumio Takemura, Yoshihito Sema, Kazuhito Kataoka