Patents by Inventor Hiroyuki Idogawa

Hiroyuki Idogawa 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: 6160035
    Abstract: The oil base pigment ink composition for writing tools comprising at least a pigment, a basic resin having an amino group and an alcohol base solvent and/or a glycol ether base solvent, wherein the basic resin described above is a resin copolymerized monomers containing at least one of a vinyl monomer having a heterocyclic amino group, a vinyl monomer having an aliphatic primary amino group, a vinyl monomer having an aliphatic secondary amino group or a vinyl monomer having an aliphatic tertiary amino group and has preferably a weight average molecular weight of 50000 or less. The pigment is preferably carbon black, particularly preferably carbon black having a pH of 6 or less.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: December 12, 2000
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventor: Hiroyuki Idogawa
  • Patent number: 5965634
    Abstract: Provided is a stable water base ink composition which has a sufficiently high concentration as ink for an ink jet-recording apparatus and writing instruments and prevents the recorded images and the written characters from being blurred or disappearing with water and sweat and which has such an excellent light fastness that the images and the characters do not deteriorate over a long period of time and does not cause a change in physical properties and precipitates. A water base dispersion liquid containing colored resin fine particles is prepared by emulsion-polymerizing a vinyl monomer in the presence of a hydrophobic dye and then diluted with water or a water soluble organic solvent, whereby the water base ink composition is produced.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: October 12, 1999
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroyuki Idogawa, Yasuaki Ogiwara, Atsushi Iwasa, Kiyokazu Sakurai
  • Patent number: 5942560
    Abstract: Provided is a colored resin fine particle water base dispersion liquid which can be a base material for an ink causing no precipitates and having storage stability. Further provided is a water base ink composition for an ink jet recording apparatus or a water base ink composition for a writing tool capable of providing recorded images or written characters and drawn lines which are clear and neither are blurred nor disappear due to water and sweat and which are so excellent in light fastness that they are not deteriorated over a long period of time, wherein the colored resin fine particle water base dispersion liquid is produced by mixing a water soluble basic dye with a mixed vinyl monomer containing a vinyl monomer having an acid functional group and emulsion-copolymerizing the above mixture.
    Type: Grant
    Filed: August 6, 1997
    Date of Patent: August 24, 1999
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroyuki Idogawa, Yasuaki Ogiwara, Atsushi Iwasa, Kiyokazu Sakurai
  • Patent number: 5498281
    Abstract: The present invention provides a recording material containing a carbonaceous powder whose surfaces are modified with a fluorine gas. Even when the recording material of the present invention is stored for a long period of time, a carbonaceous powder such as a graphite powder or carbon black neither coheres nor precipitates. For example, even if the recording material of the present invention is used in a felt pen or a ball-point pen, the carbonaceous powder does not cohere in the container or the pen point, and therefore any clogging does not occur in the pen point and good writing is possible.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: March 12, 1996
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroyuki Idogawa, Atsushi Wakata, Nobuatsu Watanabe, Yong-Bo Chong
  • Patent number: 5437715
    Abstract: The present invention provides a recording material containing a carbonaceous powder whose surfaces are modified with a fluorine gas. Even when the recording material of the present invention is stored for a long period of time, a carbonaceous powder such as a graphite powder or carbon black neither coheres nor precipitates. For example, even if the recording material of the present invention is used in a felt pen or a ball-point pen, the carbonaceous powder does not cohere in the container or the pen point, and therefore any clogging does not occur in the pen point and good writing is possible.
    Type: Grant
    Filed: August 3, 1993
    Date of Patent: August 1, 1995
    Assignee: Mitsubishi Pencil Kabushiki Kaisha
    Inventors: Hiroyuki Idogawa, Atsushi Wakata, Nobuatsu Watanabe, Yong-Bo Chong