Patents by Inventor Shubun Kujirai

Shubun Kujirai 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).

  • Publication number: 20240094650
    Abstract: An electrophotographic photosensitive member comprising a support, an electroconductive layer, an undercoat layer, a charge generating layer, and a hole transporting layer in this order, wherein when an ionization potential of the electroconductive layer is defined as IPc, the IPc is 5.4 to 5.8 eV, and when an ionization potential of the undercoat layer is defined as IPu, the IPu is 6.0 eV or more, wherein the undercoat layer comprises an electron transporting compound and a compound (?), and when an ionization potential of the compound (?) is defined as IP?, the IPc, the IPu, and the IP? satisfy relation (1): IPu?IPc>IP??IPc??(1).
    Type: Application
    Filed: August 22, 2023
    Publication date: March 21, 2024
    Inventors: KOJI TAKAHASHI, MOTOYA YAMADA, SHUBUN KUJIRAI
  • Patent number: 11237494
    Abstract: There is provided an electrophotographic photosensitive member capable of suppressing the environmental fluctuation in repeated use. A protective layer of the electrophotographic photosensitive member contains a polymer of a composition containing a hole transporting compound having two or more (meth)acryloyloxy groups and a compound having a specific structure.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: February 1, 2022
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Haruki Mori, Shubun Kujirai, Koichi Nakata
  • Patent number: 11204560
    Abstract: Provided is an electrophotographic photosensitive member including a support and a surface layer, wherein the surface layer contains a copolymer of a composition containing a specific hole transporting compound and a specific compound.
    Type: Grant
    Filed: April 22, 2020
    Date of Patent: December 21, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Patent number: 11169453
    Abstract: The present disclosure provides an electrophotographic photosensitive member having a surface layer in which an occurrence of the image deletion is suppressed; a process cartridge equipped with the electrophotographic photosensitive member; and an electrophotographic apparatus provided with the process cartridge. An electrophotographic photosensitive member has a surface layer that includes a copolymerized product of a composition including a metal oxide particle having a polymerizable functional group on a surface thereof and a polymerizable compound having a particular structure.
    Type: Grant
    Filed: June 8, 2020
    Date of Patent: November 9, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Eileen Takeuchi, Koichi Nakata, Shubun Kujirai, Haruki Mori
  • Patent number: 11067910
    Abstract: An electrophotographic photoreceptor includes a support, a photosensitive layer, and a protection layer. The protection layer contains a copolymer of a compound having a specific frame and a hole-transporting compound containing a specific polarizable functional group.
    Type: Grant
    Filed: February 7, 2020
    Date of Patent: July 20, 2021
    Assignee: Canon Kabushiki Kaisha
    Inventors: Haruki Mori, Koichi Nakata, Shubun Kujirai
  • Patent number: 11029616
    Abstract: An electrophotographic photosensitive member including: a support; and a surface layer, wherein the surface layer contains a cured product of a composition containing a curable hole-transport compound, a specific fluorine-atom-containing compound, and a specific polymerizable compound.
    Type: Grant
    Filed: June 8, 2020
    Date of Patent: June 8, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Shubun Kujirai, Koichi Nakata, Haruki Mori
  • Patent number: 11029615
    Abstract: Provided is an electrophotographic photosensitive member improved both in wear resistance and in image unevenness. The electrophotographic photosensitive member includes a support, and a photosensitive layer and a surface layer on the support, wherein the surface layer is a cured product of a composition containing a compound represented by the formula (A) and a charge-transporting substance having at least one reactive functional group selected from the group consisting of a hydroxy group, a methoxy group, an amino group, a thiol group, and a carboxyl group.
    Type: Grant
    Filed: July 23, 2020
    Date of Patent: June 8, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Takahiro Mitsui, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20210124280
    Abstract: There is provided an electrophotographic photosensitive member capable of suppressing the environmental fluctuation in repeated use. A protective layer of the electrophotographic photosensitive member contains a polymer of a composition containing a hole transporting compound having two or more (meth)acryloyloxy groups and a compound having a specific structure.
    Type: Application
    Filed: October 28, 2020
    Publication date: April 29, 2021
    Inventors: Haruki Mori, Shubun Kujirai, Koichi Nakata
  • Patent number: 10976677
    Abstract: The present disclosure provides an electrophotographic photosensitive member that has mechanical durability, and can achieve both of suppression of an image flow and adequate electrical characteristics.
    Type: Grant
    Filed: December 12, 2019
    Date of Patent: April 13, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Patent number: 10969703
    Abstract: Provided is an electrophotographic photosensitive member including a surface layer containing: a copolymerization product of a composition containing a hole-transportable compound having a chain-polymerizable functional group and a compound having a specific structure; and metal oxide particles.
    Type: Grant
    Filed: December 31, 2019
    Date of Patent: April 6, 2021
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Eileen Takeuchi, Koichi Nakata, Shubun Kujirai, Haruki Mori
  • Publication number: 20210033991
    Abstract: Provided is an electrophotographic photosensitive member improved both in wear resistance and in image unevenness. The electrophotographic photosensitive member includes a support, and a photosensitive layer and a surface layer on the support, wherein the surface layer is a cured product of a composition containing a compound represented by the formula (A) and a charge-transporting substance having at least one reactive functional group selected from the group consisting of a hydroxy group, a methoxy group, an amino group, a thiol group, and a carboxyl group.
    Type: Application
    Filed: July 23, 2020
    Publication date: February 4, 2021
    Inventors: Takahiro Mitsui, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20210033992
    Abstract: Provided is an electrophotographic photosensitive member including: a support, a photosensitive layer provided on the support, and a surface layer provided on the photosensitive layer, wherein the surface layer of the electrophotographic photosensitive member contains a cured product of a composition containing a charge transporting substance having a polymerizable functional group, a compound having a specific structure, a fluororesin particle, and polyvinyl acetal.
    Type: Application
    Filed: July 23, 2020
    Publication date: February 4, 2021
    Inventors: Mai Kaku, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20200393772
    Abstract: The present disclosure provides an electrophotographic photosensitive member having a surface layer in which an occurrence of the image deletion is suppressed; a process cartridge equipped with the electrophotographic photosensitive member; and an electrophotographic apparatus provided with the process cartridge. An electrophotographic photosensitive member has a surface layer that includes a copolymerized product of a composition including a metal oxide particle having a polymerizable functional group on a surface thereof and a polymerizable compound having a particular structure.
    Type: Application
    Filed: June 8, 2020
    Publication date: December 17, 2020
    Inventors: Eileen Takeuchi, Koichi Nakata, Shubun Kujirai, Haruki Mori
  • Publication number: 20200393775
    Abstract: An electrophotographic photosensitive member including: a support; and a surface layer, wherein the surface layer contains a cured product of a composition containing a curable hole-transport compound, a specific fluorine-atom-containing compound, and a specific polymerizable compound.
    Type: Application
    Filed: June 8, 2020
    Publication date: December 17, 2020
    Inventors: Shubun Kujirai, Koichi Nakata, Haruki Mori
  • Publication number: 20200341391
    Abstract: Provided is an electrophotographic photosensitive member including a support and a surface layer, wherein the surface layer contains a copolymer of a composition containing a specific hole transporting compound and a specific compound.
    Type: Application
    Filed: April 22, 2020
    Publication date: October 29, 2020
    Inventors: Ryoichi Tokimitsu, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20200341394
    Abstract: Provided is an electrophotographic photosensitive member having a satisfactory suppressing effect on image smearing.
    Type: Application
    Filed: April 22, 2020
    Publication date: October 29, 2020
    Inventors: Kenichi Ikari, Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Patent number: 10761442
    Abstract: Provided are an electrophotographic photosensitive member including a support and a photosensitive layer above the support, in which a surface layer of the electrophotographic photosensitive member includes a polymerization product of a composition containing a specific hole transporting compound, and an electrophotographic apparatus and a process cartridge including the electrophotographic photosensitive member. Also provided is a method of producing the electrophotographic photosensitive member, including (i) forming a coating film of a coating solution for a surface layer which is a composition containing a specific hole transporting compound, and (ii) forming the surface layer of the electrophotographic photosensitive member by a polymerization reaction of the composition containing the specific hole transporting compound.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: September 1, 2020
    Assignee: CANON KABUSHIKI KAISHA
    Inventors: Koichi Nakata, Haruki Mori, Shubun Kujirai, Shinji Takagi, Isao Kawata, Yuto Ito, Ryuji Higashi
  • Publication number: 20200272065
    Abstract: An electrophotographic photoreceptor includes a support, a photosensitive layer, and a protection layer. The protection layer contains a copolymer of a compound having a specific frame and a hole-transporting compound containing a specific polarizable functional group.
    Type: Application
    Filed: February 7, 2020
    Publication date: August 27, 2020
    Inventors: Haruki Mori, Koichi Nakata, Shubun Kujirai
  • Publication number: 20200249590
    Abstract: An electrophotographic photosensitive member which satisfies wear resistance and electrical properties, further has high image deletion prevention properties under a high temperature and high humidity environment, and a small potential variation under a low temperature and low humidity environment is provided. The electrophotographic photosensitive member includes a surface layer containing a polymerization product of a hole transporting compound having a specific structure.
    Type: Application
    Filed: January 30, 2020
    Publication date: August 6, 2020
    Inventors: Koichi Nakata, Haruki Mori, Shubun Kujirai
  • Publication number: 20200218171
    Abstract: Provided is an electrophotographic photosensitive member including a surface layer containing: a copolymerization product of a composition containing a hole-transportable compound having a chain-polymerizable functional group and a compound having a specific structure; and metal oxide particles.
    Type: Application
    Filed: December 31, 2019
    Publication date: July 9, 2020
    Inventors: Eileen Takeuchi, Koichi Nakata, Shubun Kujirai, Haruki Mori