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EP-4462191-B1 - ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC APPARATUS

EP4462191B1EP 4462191 B1EP4462191 B1EP 4462191B1EP-4462191-B1

Inventors

  • MARUYAMA, AKIHIRO
  • SEKIYA, MICHIYO
  • NISHI, MASASHI
  • KATO, Nanami
  • ISHIDA, TOMOHITO
  • NISHIDA, TSUTOMU

Dates

Publication Date
20260506
Application Date
20240326

Claims (12)

  1. An electrophotographic photosensitive member comprising in this order: a support; an undercoat layer; and a photosensitive layer, wherein the undercoat layer comprises at least one kind of polymer selected from the group consisting of: a polymer having a structural unit represented by the following formula (1); and a polymer having a structural unit represented by the following formula (2): in the formulae (1) and (2), α, β, and γ represent structures represented by the following formulae (α), (β), and (γ), respectively, and R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 21 , R 22 , R 23 , and R 24 each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a trifluoromethyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group: in the formulae (α), (β), and (γ), R 60 , R 61 , R 70 , R 71 , R 80 , and R 81 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Z a , Z b , and Z c each independently represent a single bond, an imino group, an oxygen atom, or a sulfur atom, l a , l b , and l c each independently represent an integer of 0 or more, m a represents an integer of 1 or more, m b and m c each independently represent an integer of 0 or more, when Z a represents a single bond, R 60 represents a substituted or unsubstituted alkyl group, when Z a represents an imino group or a sulfur atom, R 60 represents a hydrogen atom, or a substituted or unsubstituted alkyl group, when Z a represents an oxygen atom, and R 60 represents a hydrogen atom, m a represents an integer of 2 or more, and when Z a represents an oxygen atom, and R 60 represents a substituted or unsubstituted alkyl group, m a represents an integer of 1 or more.
  2. The electrophotographic photosensitive member according to claim 1, wherein a content of the at least one kind of polymer selected from the group consisting of: the polymer having the structural unit represented by the formula (1); and the polymer having the structural unit represented by the formula (2) with respect to a total mass of the undercoat layer is 50 mass% or more.
  3. The electrophotographic photosensitive member according to claim 1 or 2, wherein at least one of R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18 in the formula (1), and at least one of R 21 , R 22 , R 23 , and R 24 in the formula (2) each independently represent a halogen atom, a nitro group, a cyano group, a trifluoromethyl group, a substituted or unsubstituted alkoxy group having 20 or less carbon atoms, a substituted or unsubstituted thiol group having 20 or less carbon atoms, a substituted or unsubstituted amino group having 20 or less carbon atoms, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkynyl group having 20 or less carbon atoms, or a substituted or unsubstituted aryl group having 20 or less carbon atoms.
  4. The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein at least one of R 60 and R 61 in the formula (α), R 70 and R 71 in the formula (β), and R 80 and R 81 in the formula (γ) represents a substituted or unsubstituted alkyl group having 20 or less carbon atoms, or a substituted or unsubstituted aryl group having 20 or less carbon atoms.
  5. The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein l a in the formula (α), l b in the formula (β), and l c in the formula (γ) each independently represent an integer of 0 to 10.
  6. The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein m a in the formula (α) represents an integer of 1 to 40, and wherein m b in the formula (β) and m c in the formula (γ) each independently represent an integer of 0 to 40.
  7. The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein R 60 in the formula (α) represents a substituted or unsubstituted alkyl group having 20 or less carbon atoms.
  8. The electrophotographic photosensitive member according to any one of claims 1 to 7, wherein m a in the formula (α) represents an integer of 2 to 30, and wherein a sum of m a in the formula (α), m b in the formula (β), and m c in the formula (γ) is 3 to 30.
  9. The electrophotographic photosensitive member according to any one of claims 1 to 8, wherein the at least one kind of polymer selected from the group consisting of: the polymer having the structural unit represented by the formula (1); and the polymer having the structural unit represented by the formula (2) has a weight-average molecular weight of 30,000 or less.
  10. The electrophotographic photosensitive member according to any one of claims 1 to 9, wherein the undercoat layer has a volume resistivity of 1×10 10 Ω·cm or more.
  11. A process cartridge comprising: the electrophotographic photosensitive member of any one of claims 1 to 10; and at least one unit selected from the group consisting of: a charging unit; a developing unit; and a cleaning unit, the process cartridge integrally supporting the electrophotographic photosensitive member and the at least one unit, and being detachably attachable to an electrophotographic apparatus.
  12. An electrophotographic apparatus comprising: the electrophotographic photosensitive member of any one of claims 1 to 10; a charging unit; an exposing unit; a developing unit; and a transfer unit.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus. Description of the Related Art In recent years, an electrophotographic apparatus that can form an image having higher quality has been required, and the provision of such an apparatus that the stability of the quality of an image to be output at the time of its repeated use is high has been desired. In an electrophotographic photosensitive member to be used in an electrophotographic process, there is known a technology involving arranging an undercoat layer containing an electron transporting substance between a support and a photosensitive layer for the purpose of suppressing charge injection from the support side to the photosensitive layer side to suppress the occurrence of an image failure such as a black spot. In Japanese Patent Application Laid-Open No. 2014-029479, there is a description of an undercoat layer containing a cured product of a composition containing: an electron transporting substance having a polymerizable functional group; a crosslinking agent; and a resin. In addition, in Japanese Patent Application Laid-Open No. H11-228675, there is a description of an intermediate layer containing a polymer obtained by polymerizing a diphenoquinone derivative. In addition, in Japanese Patent Application Laid-Open No. 2012-032458, there is a description of an aqueous coating liquid for forming an intermediate layer, the coating liquid containing a composition containing: an electron transporting substance having a carboxyl group; a dispersant; and a resin. WO 2007/024522 A1 and JP 3 809398 B2 respectively disclose an electrophotographic photosensitive member comprising in this order a support, an undercoat layer; and a photosensitive layer, wherein the undercoat layer comprises a polymer having a naphthalene imide structure. In recent years, the electrophotographic process has been required to achieve mass printing and high-speed printing. Through an investigation made by the inventors of the present invention, it has been found that in an electrophotographic photosensitive member described in each of Japanese Patent Application Laid-Open No. 2014-029479, Japanese Patent Application Laid-Open No. H11-228675, and Japanese Patent Application Laid-Open No. 2012-032458, when the mass printing and the high-speed printing are performed, a potential fluctuation may become larger. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member that can suppress a potential fluctuation. The above-mentioned object is achieved by the present invention described below. That is, according to the present invention, there is provided an electrophotographic photosensitive member including in this order: a support; an undercoat layer; and a photosensitive layer, wherein the undercoat layer comprises at least one kind of polymer selected from the group consisting of: a polymer having a structural unit represented by the following formula (1); and a polymer having a structural unit represented by the following formula (2): in the formulae (1) and (2), α, β, and γ represent structures represented by the following formulae (α), (β), and (γ), respectively, and R11, R12, R13, R14, R15, R16, R17, R18, R21, R22, R23, and R24 each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a trifluoromethyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group: in the formulae (α), (β), and (γ), R60, R61, R70, R71, R80, and R81 each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Za, Zb, and Zc each independently represent a single bond, an imino group, an oxygen atom, or a sulfur atom, la, lb, and lc each independently represent an integer of 0 or more, ma represents an integer of 1 or more, mb and mc each independently represent an integer of 0 or more, when Za represents a single bond, R60 represents a substituted or unsubstituted alkyl group, when Za represents an imino group or a sulfur atom, R60 represents a hydrogen atom, or a substituted or unsubstituted alkyl group, when Za represents an oxygen atom, and R60 represents a hydrogen atom, ma represents an integer of 2 or more, and when Za represents an oxygen atom, and R60 represents a substituted or unsubstituted alkyl group, ma represents an integer of 1 or more. Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view for illustratin