Patents by Inventor Ryuji Yokoyama

Ryuji Yokoyama 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).

  • Aqueous pigment dispersion used for preparing ink jet recording aqueous ink, and ink jet recording aqueous ink
    Patent number: 8679243
    Abstract: An aqueous pigment dispersion used for preparing an ink jet recording aqueous ink comprises an anionic group-containing organic polymeric compound, an organic pigment, an organic pigment derivative, and the water, wherein the polymeric compound, the organic pigment, and the organic pigment derivative are dispersed in water, the organic pigment and the organic pigment derivative are a diketopyrrolopyrrole-based red pigment and a phthalimidoalkylated quinacridone, respectively, and the phthalimidoalkylated quinacridone content is in the range of 1.6 to 3.8% relative to the total (100%) of the diketopyrrolopyrrole-based red pigment and the phthalimidoalkylated quinacridone on a mass basis. Furthermore, there is provided an ink jet recording aqueous ink containing such an aqueous pigment dispersion, wherein the aqueous pigment dispersion is diluted such that the total of the organic pigment content and the organic pigment derivative content is from 1 to 8% on a mass basis.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: March 25, 2014
    Assignee: DIC Corporation
    Inventors: Ryuji Yokoyama, Takao Ogihara, Kengo Yasui
  • AQUEOUS PIGMENT DISPERSION USED FOR PREPARING INK JET RECORDING AQUEOUS INK, AND INK JET RECORDING AQUEOUS INK
    Publication number: 20140011917
    Abstract: An aqueous pigment dispersion used for preparing an ink jet recording aqueous ink comprises an anionic group-containing organic polymeric compound, an organic pigment, an organic pigment derivative, and the water, wherein the polymeric compound, the organic pigment, and the organic pigment derivative are dispersed in water, the organic pigment and the organic pigment derivative are a diketopyrrolopyrrole-based red pigment and a phthalimidoalkylated quinacridone, respectively, and the phthalimidoalkylated quinacridone content is in the range of 1.6 to 3.8% relative to the total (100%) of the diketopyrrolopyrrole-based red pigment and the phthalimidoalkylated quinacridone on a mass basis. Furthermore, there is provided an ink jet recording aqueous ink containing such an aqueous pigment dispersion, wherein the aqueous pigment dispersion is diluted such that the total of the organic pigment content and the organic pigment derivative content is from 1 to 8% on a mass basis.
    Type: Application
    Filed: February 22, 2012
    Publication date: January 9, 2014
    Applicant: DIC CORPORATION
    Inventors: Ryuji Yokoyama, Takao Ogihara, Kengo Yasui