Patents by Inventor Yu Tsukamoto

Yu Tsukamoto 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).

  • Ink composition for writing instrument and writing instrument
    Patent number: 8137019
    Abstract: The ink composition for a writing instrument has an aqueous component containing water, a thixotropic agent, a polyhydric alcohol and a pigment, dispersed in an oil component having dyes and non-dye components, wherein the IOB value for all of the dyes in the oil component is no greater than 0.9.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: March 20, 2012
    Assignee: Zebra Co., Ltd.
    Inventors: Mayumi Yamaguchi, Yu Tsukamoto, Akinori Tanaka
  • INK COMPOSITION FOR WRITING INSTRUMENT AND WRITING INSTRUMENT
    Publication number: 20100054848
    Abstract: The ink composition for a writing instrument according to the invention has an aqueous component containing water, a thixotropic agent, a polyhydric alcohol and a pigment, dispersed in an oil component having dyes and non-dye components, wherein the IOB value for all of the dyes in the oil component is no greater than 0.9.
    Type: Application
    Filed: August 24, 2009
    Publication date: March 4, 2010
    Applicant: ZEBRA CO., LTD.
    Inventors: Mayumi Yamaguchi, Yu Tsukamoto, Akinori Tanaka