Patents by Inventor Wataru Yokono

Wataru Yokono 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).

  • Water base pigment ink compositions for use in marking pens
    Patent number: 5106881
    Abstract: A water base pigment ink composition for use in marking pens which contain an absorbent ink reservoir and a pen tip connected thereto, the ink composition comprising:(a) water in amounts of not less than 50% by weight;(b) an aqueous emulsion of hollow resin particles in amounts of 0.5-40% by weight as solids;(c) a white pigement in amounts of 1-40% by weight; and(d) a water-solubilized .alpha.-methylstyrene/styrene/acrylic acid copolymer which has a weight average molecular weight of 1000-10000 and a distribution of molecular weight of 0.5-3.3, but which contains substantially no components having a weight average molecular weight of not more than 500, in amounts of 0.1-30% by weight, based on the ink compositions, respectively.The ink composition may contain chromatic or achromatic (other than white) pigments in amounts of 0.1-30% by weight based on the ink composition.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: April 21, 1992
    Assignee: Sakura Color Products Corp.
    Inventors: Hiroshi Inoue, Wataru Yokono, Yasuji Okuda
  • Water base pigment ink compositions for use in marking pens
    Patent number: 5009536
    Abstract: A water base pigment ink composition for use in marking pens which contain an absorbent ink reservoir and a pen tip connected thereto, the ink composition comprising:(a) water in amounts of not less than 50% by weight;(b) an aqueous emulsion of hollow resin particles in amounts of 0.5-40% by weight as solids;(c) a white pigment in amounts of 1-40% by weight; and(d) a water-solubilized .alpha.-methylstyrene/styrene/acrylic acid copolymer which has a weight average molecular weight of 1000-10,000 and a distribution of molecular weight of 0.5-3.3, but which contains substantially no components having a weight average molecular weight of not more than 500, in amounts of 0.1-30% by weight, based on the ink compositions, respectively.The ink composition may contain chromatic or achromatic (other than white) pigments in amounts of 0.1-30% by weight based on the ink composition.
    Type: Grant
    Filed: June 8, 1990
    Date of Patent: April 23, 1991
    Assignee: Sakura Color Products Corp.
    Inventors: Hiroshi Inoue, Wataru Yokono, Yasuji Okuda
  • Water base pigment ink compositions for use in marking pens
    Patent number: 4942185
    Abstract: A water base pigment ink composition for use in marking pens which contain an absorbent ink reservoir and a pen tip connected thereto, the ink composition comprising:(a) water in amounts of not less than 50% by weight;(b) an aqueous emulsion of hollow resin particles in amounts of 0.5-40% by weight as solids;(c) a white pigment in amounts of 1-40% by weight; and(d) a water-solubilized .alpha.-methylstyrene/styrene/acrylic acid copolymer which has a weight average molecular weight of 1000-10,000 and a distribution of molecular weight of 0.5-3.3, but which contains substantially no components having a weight average molecular weight of not more than 500, in amounts of 0.1-30% by weight, based on the ink compositions, respectively.The ink composition may contain chromatic or achromatic (other than white) pigments in amounts of 0.1-30% by weight based on the ink composition.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: July 17, 1990
    Assignee: Sakura Color Products Corp.
    Inventors: Hiroshi Inoue, Wataru Yokono, Yasuji Okuda