Patents by Inventor Takeshi Kajikawa

Takeshi Kajikawa 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).

  • Thermosensitive recording medium
    Publication number: 20020010095
    Abstract: A thermosensitive recording medium including; a support; and a thermosensitive recording layer formed overlying the support and including a leuco dye, a color developer and a sensitizer, wherein the color developer includes a compound selected from the group consisting of compounds having one of the following formulae (1), (2) and (3): 1
    Type: Application
    Filed: May 30, 2001
    Publication date: January 24, 2002
    Applicant: RICOH COMPANY, LTD
    Inventors: Hiroshi Yamada, Tomohisa Kakuda, Takeshi Kajikawa
  • Thermosensitive recording composition and thermosensitive recording material using the same
    Publication number: 20010003729
    Abstract: A thermosensitive recording composition includes a leuco dye, a color developer containing 4,4′-bisphenol S, and a sensitizer containing 4-acetylbiphenyl. A thermosensitive recording material has a support and a thermosensitive recording layer which is provided on the support and contains the above-mentioned thermosensitive recording composition.
    Type: Application
    Filed: December 1, 2000
    Publication date: June 14, 2001
    Inventors: Tomohisa Kakuda, Takeshi Kajikawa, Hiroshi Yamada
  • Thermosensitive recording medium
    Patent number: 5972836
    Abstract: A thermosensitive recording medium having a support, a thermosensitive layer provided on the support, and a protecting layer provided on the thermosensitive layer and containing montan wax particles having an average particle diameter AD of not greater than 1.5 .mu.m and such a particle size distribution that at least 99% of the montan wax particles have a particle diameter of not greater than (AD+0.5 .mu.m). The protecting layer is obtained by drying a layer of an aqueous dispersion containing an aqueous emulsion of the montan wax particles.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: October 26, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Mitsunobu Morita, Yasutomo Mori, Takeshi Kajikawa
  • Thermosensitive recording medium
    Patent number: 5919729
    Abstract: A thermosensitive recording medium having a support, a thermosensitive layer provided on the support and capable of forming a color image when heated imagewise, and a protecting layer provided on the thermosensitive layer and containing a pigment and a core-shell resin obtained by polymerizing a vinyl monomer in an emulsion containing acrylonitrile-containing polymer seeds such that a polymer of the vinyl monomer is copolymerized on each of the seeds to form a shell surrounding a core of the seed, wherein the core-shell resin meets with at least one of the following criteria (a) and (b):(a) the glass transition point Tg of the core is at least 15.degree. C.; and(b) the glass transition point Tg of the shell is at least 150.degree. C. The vinyl monomer contains acrylamide and/or methacrylamide.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: July 6, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Yasutomo Mori, Takeshi Kajikawa, Mitsunobu Morita, Mitsuru Naruse