Patents by Inventor Kotaro Sumitomo

Kotaro Sumitomo 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: 8431632
    Abstract: The invention provides a crayon which comprises an alternative plasticizer in place of the conventional phthalate ester plasticizers and yet provides writings excellent in water resistance, the crayon comprising a colorant, a gelling agent, an organic solvent, a resin component, and a plasticizer, wherein the plasticizer is at least one selected from diisononyl adipate, acetyltributyl citrate, 1,2-cyclohexanedicarboxylic acid diisononyl, and alkylsulfonic acid phenyl ester and is contained in an amount of 1 to 20% by weight based on the crayon.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: April 30, 2013
    Assignee: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Patent number: 8299143
    Abstract: The invention provides a process for producing a crayon having a desired hardness stably without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises: dissolving and dispersing a resin component and carbon black having a pH of not less than 5.0 in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating to prepare a raw material solution, pouring the raw material solution into a molding container, and cooling and gelling the raw material solution.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: October 30, 2012
    Assignee: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Patent number: 8242190
    Abstract: The invention provides a process for producing a crayon having a desired hardness stably without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises: dissolving and dispersing a resin component, carbon black having a pH of less than 5.0 and an organic amine in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating to prepare a raw material solution, pouring the raw material solution into a molding container, and cooling and gelling the raw material solution.
    Type: Grant
    Filed: August 29, 2007
    Date of Patent: August 14, 2012
    Assignee: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Patent number: 7943684
    Abstract: The invention provides a process for producing a crayon without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises dissolving and dispersing carbon black and a resin component in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating, pouring the obtained raw material solution into a molding container, and then cooling and solidifying the solution, wherein carbon black having an average particle diameter of primary particles of 20 to 100 nm is used as the carbon black.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: May 17, 2011
    Assignee: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Publication number: 20100273914
    Abstract: The invention provides a crayon which comprises an alternative plasticizer in place of the conventional phthalate ester plasticizers and yet provides writings excellent in water resistance, the crayon comprising a colorant, a gelling agent, an organic solvent, a resin component, and a plasticizer, wherein the plasticizer is at least one selected from diisononyl adipate, acetyltributyl citrate, 1,2-cyclohexanedicarboxylic acid diisononyl, and alkylsulfonic acid phenyl ester and is contained in an amount of 1 to 20% by weight based on the crayon.
    Type: Application
    Filed: July 9, 2008
    Publication date: October 28, 2010
    Applicant: SAKURA COLOR PRODUCTS CORPORATION
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Publication number: 20100016471
    Abstract: The invention provides a process for producing a crayon having a desired hardness stably without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises: dissolving and dispersing a resin component, carbon black having a pH of less than 5.0 and an organic amine in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating to prepare a raw material solution, pouring the raw material solution into a molding container, and cooling and gelling the raw material solution.
    Type: Application
    Filed: August 29, 2007
    Publication date: January 21, 2010
    Applicant: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Publication number: 20090326096
    Abstract: The invention provides a process for producing a crayon having a desired hardness stably without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises: dissolving and dispersing a resin component and carbon black having a pH of not less than 5.0 in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating to prepare a raw material solution, pouring the raw material solution into a molding container, and cooling and gelling the raw material solution.
    Type: Application
    Filed: August 29, 2007
    Publication date: December 31, 2009
    Applicant: Sakura Color Products Corporation
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Publication number: 20090247668
    Abstract: The invention provides a process for producing a crayon without poor gelation using a benzylidene sorbitol gelling agent together with the use of carbon black as a black pigment. The process comprises dissolving and dispersing carbon black and a resin component in an organic solvent, dissolving at least one gelling agent selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof in the resultant under heating, pouring the obtained raw material solution into a molding container, and then cooling and solidifying the solution, wherein carbon black having an average particle diameter of primary particles of 20 to 100 nm is used as the carbon black.
    Type: Application
    Filed: July 9, 2007
    Publication date: October 1, 2009
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Publication number: 20090209678
    Abstract: The invention provides a crayon having excellent feel when writing while having high gel hardness. The crayon comprises a colorant, a gelling agent, an organic solvent and a resin component, wherein the gelling agent is at least one selected from the group consisting of dibenzylidene sorbitol, tribenzylidene sorbitol and derivatives thereof, and the resin component comprises a combination of polyvinyl butyral resin having an average degree of polymerization of less than 350 and polyvinyl butyral resin having an average degree of polymerization of 350 or more.
    Type: Application
    Filed: July 9, 2007
    Publication date: August 20, 2009
    Applicant: SAKURA COLOR PRODUCTS CORPORATION
    Inventors: Kotaro Sumitomo, Masamitsu Takahashi, Hidetoshi Fukuo
  • Patent number: 7485406
    Abstract: The invention provides a photostorage solid drawing medium comprising a solvent, a resin soluble in the solvent, a photostorage pigment and a gelling agent, wherein the photostorage pigment comprises a long afterglow fluorescent substance comprising an alkaline earth aluminosilicate as a matrix activated with a rare earth element wherein the alkaline earth element is at least one selected from the group consisting of strontium, calcium, magnesium and barium. The solvent used is a polar solvent, particularly a mixture of water and a water-soluble organic solvent, or at least one alcoholic solvent selected from the group consisting of glycols, glycol ethers, glycol ether esters and monovalent alcohols.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: February 3, 2009
    Assignee: Sakura Color Products Corporation
    Inventors: Hidetoshi Fukuo, Masamitsu Takahashi, Kotaro Sumitomo
  • Patent number: 7291210
    Abstract: Disclosed herein is a first solid drawing material comprising water, a coloring agent, a solidifying agent that is a fatty acid alkali metal salt, and an O/W type emulsion of a separating agent that is an oily material which hardly volatilizes at room temperature. The first solid drawing material preferably contains silicone oil. A second solid drawing material is also disclosed, which comprises an organic solvent, a coloring agent, a solidifying agent that is at least one selected from the group consisting of dibenzylidene sorbitol, tribenylidene sorbitol, and derivatives thereof, a separating agent that is an oily material which hardly volatilizes at room temperature, and a resin soluble in the organic solvent. In these solid drawing materials, the separating agent is evenly dispersed, and therefore they have stable drawing properties and erasability.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: November 6, 2007
    Assignee: Sakura Color Products Corporation
    Inventors: Keiko Nakamura, Kotaro Sumitomo, Hidetoshi Fukuo
  • Publication number: 20060210924
    Abstract: The invention provides a photostorage solid drawing medium comprising a solvent, a resin soluble in the solvent, a photostorage pigment and a gelling agent, wherein the photostorage pigment comprises a long afterglow fluorescent substance comprising an alkaline earth aluminosilicate as a matrix activated with a rare earth element wherein the alkaline earth element is at least one selected from the group consisting of strontium, calcium, magnesium and barium. The solvent used is a polar solvent, particularly a mixture of water and a water-soluble organic solvent, or at least one alcoholic solvent selected from the group consisting of glycols, glycol ethers, glycol ether esters and monovalent alcohols.
    Type: Application
    Filed: April 7, 2006
    Publication date: September 21, 2006
    Inventors: Hidetoshi Fukuo, Masamitsu Takahashi, Kotaro Sumitomo
  • Publication number: 20050252409
    Abstract: Disclosed herein is a first solid drawing material comprising water, a coloring agent, a solidifying agent that is a fatty acid alkali metal salt, and an O/W type emulsion of a separating agent that is an oily material which hardly volatilizes at room temperature. The first solid drawing material preferably contains silicone oil. A second solid drawing material is also disclosed, which comprises an organic solvent, a coloring agent, a solidifying agent that is at least one selected from the group consisting of dibenzylidene sorbitol, tribenylidene sorbitol, and derivatives thereof, a separating agent that is an oily material which hardly volatilizes at room temperature, and a resin soluble in the organic solvent. In these solid drawing materials, the separating agent is evenly dispersed, and therefore they have stable drawing properties and erasability.
    Type: Application
    Filed: January 28, 2005
    Publication date: November 17, 2005
    Inventors: Keiko Nakamura, Kotaro Sumitomo, Hidetoshi Fukuo
  • Publication number: 20050197423
    Abstract: The invention provides a photostorage solid drawing medium comprising a solvent, a resin soluble in the solvent, a photostorage pigment and a gelling agent, wherein the photostorage pigment comprises a fluorescent substance represented by the general formula MO.Al2SiO8 wherein M is at least one metal element selected from the group consisting of strontium, calcium, magnesium and barium. The solvent used is a polar solvent, particularly a mixture of water and a water-soluble organic solvent, or at least one alcoholic solvent selected from the group consisting of glycols, glycol ethers, glycol ether esters and monovalent alcohols.
    Type: Application
    Filed: November 4, 2004
    Publication date: September 8, 2005
    Inventors: Hidetoshi Fukuo, Masamitsu Takahashi, Kotaro Sumitomo