Patents by Inventor Yutaka Nakashima

Yutaka Nakashima 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
    Patent number: 4571362
    Abstract: A magnetic recording medium contains, in the coating layer of a magnetic powder, 0.5-15% by weight of at least either nonmagnetic powder of Al.sub.2 O.sub.3 or Cr.sub.2 O.sub.3 and 0.5-15% by weight of .alpha.-Fe.sub.2 O.sub.3, the sum of the proportions of the nonmagnetic powder and .alpha.-Fe.sub.2 O.sub.3 not exceeding 20% by weight, all on the basis of the weight of the magnetic powder. The nonmagnetic powder and .alpha.Fe.sub.2 O.sub.3 both range in particle size from 0.1 to 2 .mu.m.
    Type: Grant
    Filed: September 21, 1982
    Date of Patent: February 18, 1986
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Nobuhiro Sato, Akira Okada, Yutaka Nakashima
  • Magnetic recording medium
    Patent number: 4423115
    Abstract: A magnetic recording medium, consisting of a base coated with a magnetic coating material, uses as a binder a polyurethane resin having a metal sulfonate group, a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol on the basis of the total binder weight, and nitrocellulose, in which magnetic particles are dispersed. The binder may contain an isocyanate compound as a crosslinking agent for added particle dispersibility.
    Type: Grant
    Filed: September 22, 1982
    Date of Patent: December 27, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Fuminori Tokuda, Yutaka Nakashima
  • Magnetic recording medium
    Patent number: 4411957
    Abstract: A magnetic recording medium, consisting of a base coated with a magnetic coating material, uses as a binder a synthetic resin having a metal sulfonate group and a vinyl chloride-vinyl acetate copolymer containing not less than 8% vinyl alcohol, in which magnetic particles are dispersed. The binder may contain an isocyanate compound as a crosslinking agent for added particle durability.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: October 25, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Fukunori Tokuda, Yutaka Nakashima
  • Magnetic recording medium
    Patent number: 4399189
    Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a first non-magnetic powder of Al.sub.2 O.sub.3 and/or Cr.sub.2 O.sub.3 at a ratio of 0.5 to 15 wt. % based on said magnetic powder; a second non-magnetic powder of TiO.sub.2, SiC, SiO.sub.2, ZrO.sub.2 and/or CeO.sub.2 at a ratio of 0.5 to 15 wt. % based on said magnetic powder and a total of said non-magnetic powders of less than 20 wt. % based on said magnetic powder.
    Type: Grant
    Filed: December 11, 1981
    Date of Patent: August 16, 1983
    Assignee: TDK Electronics Co., Ltd.
    Inventors: Yutaka Nakashima, Akira Okada