Patents by Inventor Makiko Tokita

Makiko Tokita 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).

  • Patent number: 5126010
    Abstract: An ink-jet recording sheet that contains as main ingredients 69-95% wood pulp and 4-30 wt % precipitated calcium carbonate and which has a Stockigt sizing degree of 2-25 seconds as measured for a basis weight of 64 g/m.sup.2, or a Stockigt sizing degree ranging from 5.times.(basis weight/64).sup.2 to 25.times.(basis weight/64).sup.2 at a water extracting pH of 4.5-7.5. This sheet allows a clear color to develop and provides an image having circular dots and sharply defined edges. This sheet may also incorporate a cationic synthetic polymer and an alkylketene dimer.
    Type: Grant
    Filed: November 21, 1990
    Date of Patent: June 30, 1992
    Assignee: Oji Paper Co., Ltd.
    Inventors: Akira Kobayashi, Makiko Tokita, Masahiro Nakagawa, Kenji Yasuda
  • Patent number: 4944988
    Abstract: An ink jet recording sheet having an enhanced ink-absorbing property and bright color image-forming property and an excellent surface hardness has a specific coating layer formed on a surface of a substrate sheet, which comprises a pigment and a resinous binder composed of a cationic copolymer prepared by copolymerizing (a) 99.95 molar % or less of a principal copolymerization component comprising at least one fatty acid vinyl ester comonomer with (b) 0.05 to 0.4 molar % of a cationic copolymerization component comprising at least one cationic comonomer having an ethylenically unsaturated hydrocarbon radical and a cationic radical selected from tertiary amino radicals and quaternary ammonium radicals and, optionally, a member selected from (c) an additional copolymerization component comprising at least one polymerizable non-ionic comonomer different from the fatty acid vinyl ester and (d) a graft copolymerization component comprising polyvinyl alcohol.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: July 31, 1990
    Assignee: OJI Paper Co., Ltd.
    Inventors: Kenji Yasuda, Akira Kobayashi, Makiko Tokita, Masao Maekawa, Masahiko Kitajima, Hisao Maruyama
  • Patent number: 4900620
    Abstract: An ink jet recording sheet includes a sheet-like substrate composed mainly of 70 to 100 wt % of wood pulp and 0 to 30 wt % of precipitated calcium carbonate and having a Stockigt sizing degree of not less than 2 seconds and not more than 25 seconds when formed into a sheet having a basis weight of 64 g/m.sup.2, and a coating layer composed mainly of white pigment, with the coating layer being formed on at least one side of the substrate at a weight of 1 to 10 g/m.sup.2. This sheet has a high ink absorption rate and is able to develop bright colors and sharp images.
    Type: Grant
    Filed: October 6, 1988
    Date of Patent: February 13, 1990
    Assignee: OJI Paper Co., Ltd.
    Inventors: Makiko Tokita, Masahiro Nakagawa, Akira Kobayashi, Kenji Yasuda