Patents by Inventor Masataka Kawahara

Masataka Kawahara 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: 9645515
    Abstract: An electrophotographic photosensitive member capable of outputting an image with suppressed positive ghosting, and a process cartridge and an electrophotographic apparatus each having the electrophotographic photosensitive member are provided. The electrophotographic photosensitive member has a photosensitive layer including a phthalocyanine crystal in which the compound represented by the formula (1) is contained, wherein the content of the compound represented by the formula (1) is 0.1% by mass or more and 1.7% by mass or less based on the phthalocyanine crystal.
    Type: Grant
    Filed: April 17, 2015
    Date of Patent: May 9, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Junpei Kuno, Tsutomu Nishida, Masato Tanaka, Masataka Kawahara, Kaname Watariguchi
  • Publication number: 20170123330
    Abstract: An electrophotographic photosensitive member includes a substrate and a photosensitive layer containing a phthalocyanine pigment. The crystalline particles of the phthalocyanine pigment have a crystallite correlation length r and a particle size R of 400 nm or less, and a parameter k defined by r/R is in the range of 0.17 to 0.42.
    Type: Application
    Filed: October 26, 2016
    Publication date: May 4, 2017
    Inventors: Kaname Watariguchi, Shoma Hinata, Kazuko Sakuma, Tsutomu Nishida, Jumpei Kuno, Hirofumi Kumoi, Masato Tanaka, Masataka Kawahara, Yuto Ito, Isao Kawata
  • Publication number: 20170073835
    Abstract: The present invention provides: an electrophotographic photosensitive member which reduces image defects due to ghosting not only under a normal temperature and normal humidity environment but also even under a low temperature and low humidity environment; and a novel phthalocyanine crystal. The electrophotographic photosensitive member of the present invention comprises a photosensitive layer which comprises a phthalocyanine crystal in which a N,N-dimethylformamide is contained. The content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on the phthalocyanine crystal.
    Type: Application
    Filed: November 28, 2016
    Publication date: March 16, 2017
    Inventors: Masataka Kawahara, Masato Tanaka, Jumpei Kuno, Tsutomu Nishida, Kaname Watariguchi
  • Patent number: 9563139
    Abstract: An electrophotographic photosensitive member wherein a charge generating layer of the electrophotographic photosensitive member includes a gallium phthalocyanine crystal in which an organic compound is contained, wherein the organic compound is at least one compound selected from the group consisting of dimethylsulfoxide, N,N-dimethylformamide, N-methylformamide, N-propylformamide, N-vinylformamide and N-methylpyrrolidone, the content of the organic compound is 0.1% by mass or more and 2.0% by mass or less based on a gallium phthalocyanine in the gallium phthalocyanine crystal, and a charge transporting layer of the electrophotographic photosensitive member includes a polycarbonate resin having structural units represented by formulae (1) and (2).
    Type: Grant
    Filed: October 8, 2015
    Date of Patent: February 7, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masataka Kawahara, Masato Tanaka, Jumpei Kuno, Tsutomu Nishida, Kaname Watariguchi
  • Patent number: 9541850
    Abstract: A photosensitive layer includes a gallium phthalocyanine crystal and 0.2% by mass or more and 20% by mass or less of an arene compound based on the gallium phthalocyanine crystal, and the arene compound has a halogen atom or a halogen-substituted alkyl group, and a sulfonic acid group or a sulfonic acid salt group, as a substituent.
    Type: Grant
    Filed: April 2, 2015
    Date of Patent: January 10, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Patent number: 9535345
    Abstract: A solution of a gallium phthalocyanine contains a compound of formula (1) and a gallium phthalocyanine of formula (2), H2N—CH2—R1—CH2—NH2??(1) wherein R1 represents a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 main-chain carbon atoms, a substituent of the substituted alkylene group is an alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms and being substituted with an amino group, or a hydroxy group, one of the carbon atoms in the main chain of the alkylene group may be replaced with an oxygen atom, a sulfur atom, or a bivalent group represented by the formula —NR2—, and R2 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 3 carbon atoms and being substituted with an amino group, and wherein X1 represents a chlorine atom or hydroxy group.
    Type: Grant
    Filed: May 1, 2015
    Date of Patent: January 3, 2017
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Patent number: 9535347
    Abstract: In order to provide an electrophotographic photosensitive member with which a ghost is suppressed even under a low temperature and low humidity environment, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, the electrophotographic photosensitive member has a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer and comprising a charge generating material and a hole transporting material, wherein the undercoat layer comprises a particular amine compound.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: January 3, 2017
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Kaname Watariguchi, Takeshi Murakami, Masataka Kawahara, Masato Tanaka, Akira Yoshida
  • Patent number: 9519232
    Abstract: An electrophotographic photosensitive member includes a support and a photosensitive layer on the support, and the photosensitive layer contains a hydroxygallium phthalocyanine crystal having peaks at Bragg angles 2?±0.2° of 6.9°, 7.7°, 16.4°, 24.4°, and 26.5° in CuK? X-ray diffraction.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: December 13, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Kawahara, Tsutomu Nishida, Junpei Kuno, Masato Tanaka, Kaname Watariguchi
  • Patent number: 9459545
    Abstract: The present invention provides an electrophotographic photosensitive member which can output images with reduced image defects due to ghosting not only under a normal temperature and normal humidity environment but also even under a low temperature and low humidity environment as especially severe conditions, and a manufacturing method thereof; and a process cartridge and an electrophotographic apparatus each having the electrophotographic photosensitive member. Accordingly, the electrophotographic photosensitive member of the present invention having a support and a photosensitive layer on the support includes the photosensitive layer which contains a solid solution of hydroxygallium phthalocyanine and a compound represented by the following Formula (1) or Formula (1)?, the solid solution having peaks at Bragg angles 2? of 7.4°±0.3° and 28.3°±0.3° in CuK? characteristic X-ray diffraction.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: October 4, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masato Tanaka, Tsutomu Nishida, Masataka Kawahara
  • Patent number: 9459542
    Abstract: Provided is an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus each having the electrophotographic photosensitive member that can output an image having less image defects due to a ghost phenomenon not only under a normal-temperature, normal-humidity environment but also under a low-temperature, low-humidity environment as a particularly severe condition. The electrophotographic photosensitive member includes a support and a photosensitive layer formed on the support, in which the photosensitive layer includes a gallium phthalocyanine crystal containing a specific amine compound in itself.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: October 4, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masato Tanaka, Masataka Kawahara, Kaname Watariguchi, Takeshi Murakami, Akira Yoshida
  • Patent number: 9436106
    Abstract: Provided is an electrophotographic photosensitive member, including a photosensitive layer that includes a phthalocyanine crystal in which a compound represented by the following formula (1) is contained: in the formula (1), X represents a vinyl group or a propyl group.
    Type: Grant
    Filed: April 17, 2015
    Date of Patent: September 6, 2016
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Junpei Kuno, Tsutomu Nishida, Masato Tanaka, Masataka Kawahara, Kaname Watariguchi
  • Publication number: 20160252830
    Abstract: An electrophotographic photosensitive member has a support, a charge generation layer, and a charge transport layer in this order, the charge transport layer containing a charge transport material. The charge transport layer is a surface layer of the electrophotographic photosensitive member and contains a polycarbonate resin having a structural unit selected from group A and a structural unit selected from group B (groups A and B defined in the disclosure).
    Type: Application
    Filed: February 25, 2016
    Publication date: September 1, 2016
    Inventors: Yota Ito, Daisuke Miura, Shoma Hinata, Hiroyuki Tomono, Takashi Anezaki, Tatsuya Yamaai, Kazumichi Sugiyama, Masataka Kawahara, Hirotoshi Uesugi, Akihiro Maruyama, Hirofumi Kumoi, Masato Tanaka
  • Publication number: 20160252829
    Abstract: An electrophotographic photosensitive member has a support, a charge generation layer, and a charge transport layer in this order, the charge transport layer containing a charge transport material. The charge transport layer is a surface layer of the electrophotographic photosensitive member and contains a polycarbonate resin having a structural unit selected from group A and a structural unit selected from group B (groups A and B defined in the disclosure).
    Type: Application
    Filed: February 25, 2016
    Publication date: September 1, 2016
    Inventors: Masataka Kawahara, Hirotoshi Uesugi, Akihiro Maruyama, Hirofumi Kumoi, Masato Tanaka, Hiroyuki Tomono, Shoma Hinata, Yota Ito, Daisuke Miura, Takashi Anezaki, Tatsuya Yamaai, Kazumichi Sugiyama
  • Publication number: 20160252834
    Abstract: An electrophotographic photoconductor comprises a support, an undercoat layer, a charge generation layer, and a hole transport layer in this order. The undercoat layer comprises an electron transport substance, and the charge generation layer comprises a gallium phthalocyanine crystal and an amide compound represented by formula (N1): where R1 represents a methyl group, a propyl group, or a vinyl group.
    Type: Application
    Filed: February 25, 2016
    Publication date: September 1, 2016
    Inventors: Kaname Watariguchi, Masato Tanaka, Masataka Kawahara, Jumpei Kuno
  • Publication number: 20160252833
    Abstract: An electrophotographic photosensitive member includes a support member, a charge generating layer, and a charge transport layer in that order. The charge generating layer contains a gallium phthalocyanine crystal containing therein at least one amide compound selected from the group consisting of N-methylformamide, N-propylformamide, and N-vinylformamide. The charge transport layer contains fluorine-containing resin particles and a fluorine-containing copolymer.
    Type: Application
    Filed: February 26, 2016
    Publication date: September 1, 2016
    Inventors: Hirofumi Kumoi, Masataka Kawahara, Masato Tanaka
  • Publication number: 20160216620
    Abstract: An electrophotographic photosensitive member includes a support and a photosensitive layer in this order. The photosensitive layer of the electrophotographic photosensitive member contains a chlorogallium phthalocyanine crystal having peaks at 7.8°, 16.4°, 24.3°, and 27.8° in an X-ray diffraction pattern (Bragg angle: 2?±0.2°) using the CuK? line.
    Type: Application
    Filed: January 25, 2016
    Publication date: July 28, 2016
    Inventors: Tsutomu Nishida, Masataka Kawahara, Masato Tanaka
  • Publication number: 20160154328
    Abstract: To provide an electrophotographic photosensitive member that can allow a high-quality image, in which photomemory after repeated use in a high-speed process is suppressed, to be output, as well as a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member. An electrophotographic photosensitive member wherein a charge generating layer includes a gallium phthalocyanine crystal in which an organic compound is contained, wherein the organic compound is at least one compound selected from the group consisting of dimethylsulfoxide, N,N-dimethylformamide, N-methylformamide, N-propylformamide, N-vinylformamide and N-methylpyrrolidone, the content of the organic compound is 0.1% by mass or more and 2.0% by mass or less based on a gallium phthalocyanine in the gallium phthalocyanine crystal, and a charge transporting layer includes a polycarbonate resin having structural units represented by the following formula (1).
    Type: Application
    Filed: November 17, 2015
    Publication date: June 2, 2016
    Inventors: Hirofumi Kumoi, Shoma Hinata, Masataka Kawahara, Masato Tanaka
  • Publication number: 20160154326
    Abstract: The charge generating layer includes a gallium phthalocyanine crystal in which an organic compound (P) is contained, the organic compound (P) is at least one compound selected from the group consisting of dimethylsulfoxide, N,N-dimethylformamide, N-methylformamide, N-propylformamide, N-vinylformamide and N-methylpyrrolidone, the content of the organic compound (P) is 0.1% by mass or more and 1.5% by mass or less based on a gallium phthalocyanine in the gallium phthalocyanine crystal, and the charge transporting layer includes a resin having a siloxane structure, and a compound (Q) having a boiling point of 150° C. or more at 1 atm.
    Type: Application
    Filed: October 29, 2015
    Publication date: June 2, 2016
    Inventors: Hirofumi Kumoi, Shoma Hinata, Masataka Kawahara, Masato Tanaka
  • Publication number: 20160139516
    Abstract: An electrophotographic photosensitive member including a support, and a charge generating layer and a charge transporting layer on the support, wherein the charge generating layer includes a gallium phthalocyanine crystal in which an organic compound is contained, wherein the organic compound is at least one compound selected from the group consisting of dimethylsulfoxide, N,N-dimethylformamide, N-methylformamide, N-propylformamide, N-vinylformamide and N-methylpyrrolidone, the content of the organic compound is 0.1% by mass or more and 1.5% or less based on a gallium phthalocyanine in the gallium phthalocyanine crystal, and the charge transporting layer includes a polyester resin having a structural unit represented by formula (1).
    Type: Application
    Filed: November 9, 2015
    Publication date: May 19, 2016
    Inventors: Masataka Kawahara, Masato Tanaka, Jumpei Kuno, Tsutomu Nishida, Kaname Watariguchi
  • Patent number: 9341965
    Abstract: A photosensitive layer of an electrophotographic photosensitive member contains a hydroxygallium phthalocyanine crystal of a crystalline form having peaks at Bragg angles 2?±0.2° of 7.0°, 16.6°, 20.8°, and 26.9° in X-ray diffraction with CuK? radiation.
    Type: Grant
    Filed: November 24, 2014
    Date of Patent: May 17, 2016
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara