Patents by Inventor Kaneaki Niita

Kaneaki Niita 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).

  • Magnetic recording medium wherein the magnetic layer contains components having specified polar groups, particle diameters and surface areas or which are in specific relative ratios
    Patent number: 5066539
    Abstract: A magnetic recording medium improved in electromagnetic conversion characteristics and runnability is disclosed. The magnetic recording medium is formed by coating a non-magnetic substrate with a magnetic layer. The magnetic layer contains a fine ferromagnetic powder having a specific surface area larger than 45 m.sup.2 /g, a binder having polar groups such as --SO.sub.3 M and --OSO.sub.3 M in the molecule in an amount of 0.2 to 0.8 .mu.mol per m.sup.2 of the specific surface area of the ferromagnetic powder, and a compound having 2 or more carboxylic groups in an amount of 0.5 to 5.0 .mu.mol per m.sup.2 of the specific surrface of the ferromagnetic powder. The magnetic layer is further incorporated with a carbon powder having a mean diameter of 200 to 400 nm and a specific surface area of 5 to 20 m.sup.2 /g to improve the runnability of the magnetic recording medium while keeping the improved magnetic characteristics.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: November 19, 1991
    Assignee: Sony Corporation
    Inventors: Makoto Inoue, Hiroshi Miura, Kaneaki Niita, Toshiyuki Sano, Yoshitaka Tsukidate, Takahiro Miyazaki