Patents by Inventor Naoto Kamata

Naoto Kamata 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: 11926741
    Abstract: A quinacridone solid solution pigment that allows a colored product to have high chroma and a properly yellowish hue and has a controlled particle diameter, and a method for producing the quinacridone solid solution pigment. In the method, a water-containing crude quinacridone solid solution is produced by a co-cyclization reaction of a diarylaminoterepththalic acid and a dialkylarylaminoterephthalic acid in polyphosphoric acid, then the resulting water-containing crude quinacridone solid solution having a mass ratio of unsubstituted quinacridone to a 2,9-dialkylquinacridone of 85:15 to 60:40 is dried, thereby obtaining a powdery, crude quinacridone solid solution having a water content of less than 1%. Then, the resulting powdery, crude quinacridone solid solution is heated in a liquid medium that does not dissolve the crude quinacridone solid solution. Also, a pigment dispersion liquid and an inkjet ink each containing the obtained quinacridone solid solution pigment are provided.
    Type: Grant
    Filed: March 30, 2018
    Date of Patent: March 12, 2024
    Assignee: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Naoto Kamata, Sachio Yoshikawa
  • Patent number: 11773267
    Abstract: There is provided a technique for producing a quinacridone solid solution pigment, the technique making it possible to obtain a quinacridone solid solution pigment which produces a colored product having high chroma and a bluish hue, more preferably which has controlled particle diameters.
    Type: Grant
    Filed: May 16, 2022
    Date of Patent: October 3, 2023
    Assignee: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Naoto Kamata, Toshiyuki Hitotsuyanagi, Sachio Yoshikawa, Satoshi Minami
  • Patent number: 11535755
    Abstract: There is provided a technique for producing a quinacridone solid solution pigment, the technique making it possible to obtain a quinacridone solid solution pigment which produces a colored product having high chroma and a bluish hue, more preferably which has controlled particle diameters.
    Type: Grant
    Filed: October 10, 2017
    Date of Patent: December 27, 2022
    Assignee: Dainichiseika Color & Chemicals Mfg. Co.. Ltd.
    Inventors: Naoto Kamata, Toshiyuki Hitotsuyanagi, Sachio Yoshikawa, Satoshi Minami
  • Publication number: 20220275214
    Abstract: There is provided a technique for producing a quinacridone solid solution pigment, the technique making it possible to obtain a quinacridone solid solution pigment which produces a colored product having high chroma and a bluish hue, more preferably which has controlled particle diameters.
    Type: Application
    Filed: May 16, 2022
    Publication date: September 1, 2022
    Inventors: Naoto KAMATA, Toshiyuki HITOTSUYANAGI, Sachio YOSHIKAWA, Satoshi MINAMI
  • Publication number: 20200407563
    Abstract: The present invention relates to a technique for providing a quinacridone solid solution pigment, by which a quinacridone solid solution pigment that allows a colored product to have high chroma and a properly yellowish hue, and suitably, that has a controlled particle diameter and has the above-described, desired hue can be obtained.
    Type: Application
    Filed: March 30, 2018
    Publication date: December 31, 2020
    Inventors: Naoto KAMATA, Sachio YOSHIKAWA
  • Publication number: 20200062965
    Abstract: There is provided a technique for producing a quinacridone solid solution pigment, the technique making it possible to obtain a quinacridone solid solution pigment which produces a colored product having high chroma and a bluish hue, more preferably which has controlled particle diameters.
    Type: Application
    Filed: October 10, 2017
    Publication date: February 27, 2020
    Applicant: Dainichiseika Color & Chemicals MFG. Co., Ltd.
    Inventors: Naoto KAMATA, Toshiyuki HITOTSUYANAGI, Sachio YOSHIKAWA, Satoshi MINAMI
  • Patent number: 7993446
    Abstract: This invention relates to a dispersant for an organic pigment comprising a compound represented by the below-described formula (1) or (2), and also to its use. According to the present invention, it is possible to provide a dispersant or the like, which can afford a coating formulation for a color filter. The coating formulation is prevented from an increase in viscosity and a reduction in storage stability even when the concentration of a pigment is high, and can fabricate the color filter with excellent transparency and color quality.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: August 9, 2011
    Assignee: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Hiroaki Saikatsu, Hiromitsu Yanagimoto, Naoto Kamata, Michiei Nakamura
  • Publication number: 20100315733
    Abstract: This invention relates to a dispersant for an organic pigment comprising a compound represented by the below-described formula (1) or (2), and also to its use. According to the present invention, it is possible to provide a dispersant or the like, which can afford a coating formulation for a color filter. The coating formulation is prevented from an increase in viscosity and a reduction in storage stability even when the concentration of a pigment is high, and can fabricate the color filter with excellent transparency and color quality.
    Type: Application
    Filed: January 30, 2008
    Publication date: December 16, 2010
    Applicant: DAINICHISEIKA COLOR & CHEMICALS MFG. CO., LTD.
    Inventors: Hiroaki Saikatsu, Hiromitsu Yanagimoto, Naoto Kamata, Michiei Nakamura
  • Patent number: 7393404
    Abstract: A pigment dispersant contains the following component (a) alone or the following components (a) and (b) in combination: Component (a): a composite pigment formed of a diketopyrrolopyrrole pigment having a sulfonic group and another diketopyrrolopyrrole pigment having no sulfonic group, wherein the number of sulfonic group per molecule of the diketopyrrolopyrrole pigments in the composite pigment is from 0.05 to 0.5; and Component (b): a pigment other than the component (a), wherein the pigment has a sulfonic group or its metal salt, ammonium salt or amine salt. Also disclosed are a colored composition for color filters, a process for the fabrication of a color filter, the color filter fabricated by the process, an image display device including the color filter, and an information communication equipment including the image display device.
    Type: Grant
    Filed: February 15, 2006
    Date of Patent: July 1, 2008
    Assignee: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Hiroaki Saikatsu, Hiromitsu Yanagimoto, Naoto Kamata, Kazuhito Ooki, Yutaka Miura, Shigeru Sakamoto, Akio Yoshida, Michiei Nakamura
  • Patent number: 7347894
    Abstract: There is disclosed a pigment dispersant comprises the compound represented by the following formula (I) or a metal salt, ammonium salt, amine salt or alkylammoniumchloride salt thereof. Also disclosed are a colored composition for CF, a process for the fabrication of a CF, the color filter fabricated by the process, an image display device including the color filter, and an information communication equipment including the image display device.
    Type: Grant
    Filed: April 6, 2006
    Date of Patent: March 25, 2008
    Assignee: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Hiromitsu Yanagimoto, Hiroaki Saikatsu, Naoto Kamata, Shigeru Sakamoto, Akio Yoshida, Michiei Nakamura
  • Publication number: 20060241227
    Abstract: There is disclosed a pigment dispersant comprises the compound represented by the following formula (I) or a metal salt, ammonium salt, amine salt or alkylammoniumchloride salt thereof. Also disclosed are a colored composition for CF, a process for the fabrication of a CF, the color filter fabricated by the process, an image display device including the color filter, and an information communication equipment including the image display device. These colored composition, process, color filter, image display device and information communication equipment all make either direct or indirect use of the pigment dispersant.
    Type: Application
    Filed: April 6, 2006
    Publication date: October 26, 2006
    Applicant: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Hiromitsu Yanagimoto, Hiroaki Saikatsu, Naoto Kamata, Shigeru Sakamoto, Akio Yoshida, Michiei Nakamura
  • Publication number: 20060185558
    Abstract: A pigment dispersant contains the following component (a) alone or the following components (a) and (b) in combination: Component (a): a composite pigment formed of a diketopyrrolopyrrole pigment having a sulfonic group and another diketopyrrolopyrrole pigment having no sulfonic group, wherein the number of sulfonic group per molecule of the diketopyrrolopyrrole pigments in the composite pigment is from 0.05 to 0.5; and Component (b): a pigment other than the component (a), wherein the pigment has a sulfonic group or its metal salt, ammonium salt or amine salt. Also disclosed are a colored composition for color filters, a process for the fabrication of a color filter, the color filter fabricated by the process, an image display device including the color filter, and an information communication equipment including the image display device.
    Type: Application
    Filed: February 15, 2006
    Publication date: August 24, 2006
    Applicant: Dainichiseika Color & Chemicals Mfg. Co., Ltd.
    Inventors: Hiroaki Saikatsu, Hiromitsu Yanagimoto, Naoto Kamata, Kazuhito Ooki, Yutaka Miura, Shigeru Sakamoto, Akio Yoshida, Michiei Nakamura