Patents by Inventor Yasuki Karita

Yasuki Karita 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 producing magnetic fluid
    Patent number: 5240628
    Abstract: A magnetic fluid is produced by adding a solution of N-polyalkylenepolyamine-substituted alkenylsuccinimide in a hydrocarbon solvent to an aqueous suspension of fine particles of ferrites, thereby adsorbing the N-polyalkylenepolyamine-substituted alkenylsuccinimide onto the fine particles of ferrites, distilling off water and the hydrocarbon solvent therefrom, and dispersing the fine particles of N-polyalkylenepolyamine-substituted alkenylsuccinimide-adsorbed magnetites as residues into a base oil of low vapor pressure having a vapor pressure of not more than 0.1 mmHg at 25.degree. C.
    Type: Grant
    Filed: December 18, 1991
    Date of Patent: August 31, 1993
    Assignee: NOK Corporation
    Inventors: Takao Kanno, Yutaka Kouda, Yasuki Karita, Hirokazu Nagato, Takahiro Ishizuka