Patents by Inventor Tomoyuki YAMAMURA

Tomoyuki YAMAMURA 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).

  • Reversibly thermochromic aqueous ink composition and writing instrument using the same
    Patent number: 11267978
    Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: March 8, 2022
    Assignees: KABUSHIKI KAISHA PILOT CORPORATION, THE PILOT INK CO., LTD.
    Inventors: Katsuyuki Fujita, Yasuaki Kambe, Masayuki Mita, Tomoyuki Yamamura
  • REVERSIBLY THERMOCHROMIC AQUEOUS INK COMPOSITION AND WRITING INSTRUMENT USING THE SAME
    Publication number: 20200325351
    Abstract: To provide a reversibly thermochromic aqueous ink composition excellent in dispersion stability of a reversibly thermochromic microcapsule pigment and a writing instrument using the same. Disclosed is a reversibly thermochromic aqueous ink composition comprising a reversibly thermochromic microcapsule pigment encapsulating a reversibly thermochromic composition comprising (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium to determine an occurrence temperature of a coloring reaction of the component (a) and the component (b), and a vehicle comprising water and a specific gravity adjuster selected from the group consisting of an oxyacid belonging to Group 6 having an atomic weight of 90 to 185 or salt thereof.
    Type: Application
    Filed: October 16, 2018
    Publication date: October 15, 2020
    Applicants: KABUSHIKI KAISHA PILOT CORPORATION (also trading as PILOT CORPORATION), THE PILOT INK CO., LTD.
    Inventors: Katsuyuki FUJITA, Yasuaki KAMBE, Masayuki MITA, Tomoyuki YAMAMURA