Patents by Inventor Hiroshi Miyashita

Hiroshi Miyashita 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).

  • Ball-point pen ink composition erasable by rubber eraser
    Patent number: 4357431
    Abstract: A ball-point pen ink composition comprising at least a polymeric substance selected form a group consisting of polyisobutylene and ethylene-propylene copolymer, a wax which is solid or semi-solid at room temperature, pigment particles and a low-boiling solvent having a boiling point lower than 200.degree. C. This ball-point pen ink produces writing traces which can easily be erased by an ordinary rubber eraser, especially, even after passage of several days after initial writing.
    Type: Grant
    Filed: June 24, 1981
    Date of Patent: November 2, 1982
    Assignee: Pentel Kabushiki Kaisha
    Inventors: Nobuyuki Murakami, Hiroshi Miyashita