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: 9086640
    Abstract: A photosensitive layer of an electrophotographic photosensitive member includes a phthalocyanine pigment and a specific dicyanoethylene compound. Alternatively, the photosensitive layer and/or an undercoat layer of the electrophotographic photosensitive member include a specific dicyanoethylene compound, and the photosensitive layer includes the phthalocyanine pigment.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: July 21, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Junpei Kuno, Kaname Watariguchi, Masataka Kawahara, Masato Tanaka
  • Patent number: 9068083
    Abstract: Provided is a method of producing an electrophotographic photosensitive member having improved sensitivity and capable of outputting 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 method of producing a gallium phthalocyanine crystal includes subjecting a gallium phthalocyanine and a specific amine compound, which are added to a solvent, to a milling treatment to perform crystal transformation of the gallium phthalocyanine. In addition, the gallium phthalocyanine crystal is used in the photosensitive layer of the electrophotographic photosensitive member.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: June 30, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masato Tanaka, Masataka Kawahara, Kaname Watariguchi, Takeshi Murakami, Akira Yoshida
  • Patent number: 9057969
    Abstract: A photosensitive layer or a charge generation layer of an electrophotographic photosensitive member contains a gallium phthalocyanine and a particular diamine compound such as 1,2-diaminoethane or 1,3-diaminopropane. The content of the particular diamine compound in the photosensitive layer or the charge generation layer is from 10 ppm to 1,000 ppm (mass ratio) based on the gallium phthalocyanine.
    Type: Grant
    Filed: January 29, 2014
    Date of Patent: June 16, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Publication number: 20150147691
    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: Application
    Filed: November 24, 2014
    Publication date: May 28, 2015
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Patent number: 9040218
    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: January 29, 2014
    Date of Patent: May 26, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Patent number: 9034554
    Abstract: Provided is a method of producing an electrophotographic photosensitive member having improved sensitivity and capable of outputting 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 method of producing a gallium phthalocyanine crystal includes subjecting a gallium phthalocyanine and a specific amine compound, which are added to a solvent, to a milling treatment to perform crystal transformation of the gallium phthalocyanine. In addition, the gallium phthalocyanine crystal is used in the photosensitive layer of the electrophotographic photosensitive member.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: May 19, 2015
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Masato Tanaka, Masataka Kawahara, Kaname Watariguchi, Takeshi Murakami, Akira Yoshida
  • Patent number: 8993204
    Abstract: According to aspects of the present invention, an electrophotographic photosensitive member includes a surface layer comprising a cured resin obtained by polymerizing a compound having at least one polymerizable functional group. Aspects of the present invention provide an electrophotographic photosensitive member whose surface layer comprises a compound (urea derivative) having a certain structure, a method for producing the electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member.
    Type: Grant
    Filed: October 26, 2010
    Date of Patent: March 31, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masaki Nonaka, Masato Tanaka, Masataka Kawahara, Michiyo Sekiya, Akira Yoshida
  • Patent number: 8974991
    Abstract: Provided is an electrophotographic photosensitive member including a support and a photosensitive layer formed on the support, in which the photosensitive layer includes a phthalocyanine crystal containing a compound satisfying the following formulae (A) and (B) in itself: 8.9??P?10.7 (A) and ?3.2?L??1.5 (B) (in the formula (A), ?P represents a polar term of Hansen Solubility Parameters, and in the formula (B), L represents an energy level (eV) of an LUMO (lowest unoccupied molecular orbital) obtained as a result of structural optimization calculation based on density functional calculation B3LYP/6-31G).
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: March 10, 2015
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masataka Kawahara, Masato Tanaka, Kaname Watariguchi, Takeshi Murakami, Akira Yoshida
  • Publication number: 20140363759
    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: Application
    Filed: August 25, 2014
    Publication date: December 11, 2014
    Inventors: Kaname Watariguchi, Takeshi Murakami, Masataka Kawahara, Masato Tanaka, Akira Yoshida
  • Publication number: 20140322637
    Abstract: In an electrophotographic photosensitive member including a charge-generating layer, the charge-generating layer has a matrix-domain structure; in the matrix-domain structure, the domain contains a charge-generating substance, and the matrix contains a binder resin and a fluoranthene compound.
    Type: Application
    Filed: April 28, 2014
    Publication date: October 30, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Junpei Kuno, Takeshi Murakami, Tsutomu Nishida, Masataka Kawahara, Kaname Watariguchi
  • Publication number: 20140308606
    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: Application
    Filed: November 29, 2012
    Publication date: October 16, 2014
    Inventors: Masato Tanaka, Masataka Kawahara, Kaname Watariguchi, Takeshi Murakami, Akira Yoshida
  • Patent number: 8841052
    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: November 21, 2012
    Date of Patent: September 23, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kaname Watariguchi, Takeshi Murakami, Masataka Kawahara, Masato Tanaka, Akira Yoshida
  • Publication number: 20140212801
    Abstract: A photosensitive layer or a charge generation layer of an electrophotographic photosensitive member contains a gallium phthalocyanine and a particular diamine compound such as 1,2-diaminoethane or 1,3-diaminopropane. The content of the particular diamine compound in the photosensitive layer or the charge generation layer is from 10 ppm to 1,000 ppm (mass ratio) based on the gallium phthalocyanine.
    Type: Application
    Filed: January 29, 2014
    Publication date: July 31, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Publication number: 20140212804
    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: Application
    Filed: January 29, 2014
    Publication date: July 31, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Masato Tanaka, Masataka Kawahara
  • Publication number: 20140141362
    Abstract: An electrophotographic photosensitive member includes a support, an undercoat layer formed on the support, and a photosensitive layer which is formed on the undercoat layer and contains a charge generating substance and a hole transporting substance. The undercoat layer contains a specific amine compound, titanium oxide crystal particles having an average primary particle diameter of 3 nm or more and 15 nm or less and an organic resin.
    Type: Application
    Filed: November 12, 2013
    Publication date: May 22, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Kaname Watariguchi, Masato Tanaka, Masataka Kawahara, Akira Yoshida
  • Patent number: 8703372
    Abstract: An electrophotographic photosensitive member includes a support, a charge-generating layer disposed on the support, and a charge-transporting layer disposed on the charge-generating layer, in which the charge-generating layer contains a charge-generating substance and a compound represented by the formula (1). A process cartridge includes the electrophotographic photosensitive member described above. An electrophotographic apparatus includes the electrophotographic photosensitive member described above.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: April 22, 2014
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takeshi Murakami, Masataka Kawahara, Kaname Watariguchi, Masato Tanaka, Akira Yoshida
  • Publication number: 20140065530
    Abstract: A photosensitive layer of an electrophotographic photosensitive member includes a phthalocyanine pigment and a specific dicyanoethylene compound. Alternatively, the photosensitive layer and/or an undercoat layer of the electrophotographic photosensitive member include a specific dicyanoethylene compound, and the photosensitive layer includes the phthalocyanine pigment.
    Type: Application
    Filed: August 29, 2013
    Publication date: March 6, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Junpei Kuno, Kaname Watariguchi, Masataka Kawahara, Masato Tanaka
  • Publication number: 20140065531
    Abstract: A charge-generating layer of an electrophotographic photosensitive member includes a phthalocyanine pigment and a specific tricyanoethylene compound. Alternatively, the charge-generating layer and/or an undercoat layer of the electrophotographic photosensitive member includes a specific tricyanoethylene compound, and the charge-generating layer includes the phthalocyanine pigment.
    Type: Application
    Filed: August 29, 2013
    Publication date: March 6, 2014
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Tsutomu Nishida, Junpei Kuno, Masataka Kawahara, Kaname Watariguchi, Masato Tanaka
  • Patent number: 8088541
    Abstract: The present invention relates to a polyvinyl acetal resin having a specific repeating structural unit, an electrophotographic photosensitive member using the polyvinyl acetal resin, and a process cartridge and an electrophotographic apparatus each having the electrophotographic photosensitive member.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: January 3, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masato Tanaka, Atsushi Fujii, Yuka Ishiduka, Masataka Kawahara, Masaki Nonaka
  • Publication number: 20110129768
    Abstract: According to aspects of the present invention, an electrophotographic photosensitive member includes a surface layer comprising a cured resin obtained by polymerizing a compound having at least one polymerizable functional group. Aspects of the present invention provide an electrophotographic photosensitive member whose surface layer comprises a compound (urea derivative) having a certain structure, a method for producing the electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus including the electrophotographic photosensitive member.
    Type: Application
    Filed: October 26, 2010
    Publication date: June 2, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: Masaki Nonaka, Masato Tanaka, Masataka Kawahara, Michiyo Sekiya, Akira Yoshida