CN-122018264-A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus

CN122018264ACN 122018264 ACN122018264 ACN 122018264ACN-122018264-A

Abstract

An electrophotographic photoreceptor, a process cartridge, and an image forming apparatus, the electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer disposed on the conductive substrate, wherein an outermost layer contains a charge transporting material, a polyarylate resin having a dicarboxylic acid unit represented by the following formula (A) and a diol unit represented by the following formula (B), a polycarbonate resin, and a phenol compound having 3 or less phenolic functional groups and a molecular weight of 300 or more, and the outermost layer has a dielectric loss tangent tan delta value of 0.50 or less at a frequency of 1 Hz. [ chemical formula 1]

Inventors

SASAKI TOMOYA
OYAMADA YUKI
Kiko Youchi
KANO FUYUKI
GAO YANGPING
FUJII RYOUSUKE
Kusano Kawoo
IDE KENTA

Assignees

富士胶片商业创新有限公司

Dates

Publication Date: 20260512
Application Date: 20251009
Priority Date: 20241111

Claims (13)

1. An electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer disposed on the conductive substrate, The outermost layer contains a charge transporting material, a polyarylate resin having a dicarboxylic acid unit represented by the following formula (A) and a diol unit represented by the following formula (B), a polycarbonate resin, and a phenol compound having 3 or less phenolic functional groups and a molecular weight of 300 or more, The dielectric loss tangent tan delta at the frequency of 1Hz of the outermost layer is 0.50 or less, [ Chemical formula 1] In the formula (A), ar A1 and Ar A2 are each independently an aromatic ring which may have a substituent, L A is a single bond or a divalent linking group, n A1 is 0, 1 or 2, In the formula (B), ar B1 and Ar B2 are each independently an aromatic ring which may have a substituent, L B is a single bond, an oxygen atom, a sulfur atom or-C (Rb 1 ）（Rb 2 ）-,n B1 is 0, 1 or 2, Rb 1 and Rb 2 are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms, and Rb 1 and Rb 2 may be bonded to each other to form a cyclic alkyl group.
2. The electrophotographic photoreceptor according to claim 1, wherein, The dielectric loss tangent tan delta of the outermost layer at a frequency of 1Hz is 0.40 or less.
3. The electrophotographic photoreceptor according to claim 1 or 2, wherein, The phenol compound contains a phenol compound having 2 or less phenol functional groups and a molecular weight of 350 or more.
4. The electrophotographic photoreceptor according to any of claim 1 to 3, wherein, The dicarboxylic acid unit represented by the formula (A) comprises at least one selected from the group consisting of a dicarboxylic acid unit (A1) represented by the following formula (A1), a dicarboxylic acid unit (A2) represented by the following formula (A2), a dicarboxylic acid unit (A3) represented by the formula (A3), a dicarboxylic acid unit (A4) represented by the formula (A4) and a dicarboxylic acid unit (A5) represented by the formula (A5), [ Chemical formula 2] In the formula (A1), n 101 is an integer of 0 to 4, n 101 Ra 101 are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, In the formula (A2), n 201 and n 202 are each independently an integer of 0 to 4, n 201 Ra 201 and n 202 Ra 202 are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, In the formula (A3), n 301 and n 302 are each independently an integer of 0 to 4, n 301 Ra 301 and n 302 Ra 302 are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, In the formula (A4), n 401 is an integer of 0 to 6, n 401 Ra 401 are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, In formula (A5), n 501 、n 502 and n 503 are each independently an integer of 0 to 4, and n 501 Ra 501 、n 502 Ra 502 and n 503 Ra 503 are each independently an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.
5. The electrophotographic photoreceptor according to any of claims 1 to 4, wherein, The diol unit represented by the formula (B) includes at least one selected from the group consisting of a diol unit (B1) represented by the following formula (B1), a diol unit (B2) represented by the following formula (B2), a diol unit (B3) represented by the formula (B3), a diol unit (B4) represented by the formula (B4), a diol unit (B5) represented by the formula (B5), a diol unit (B6) represented by the formula (B6), a diol unit (B7) represented by the formula (B7) and a diol unit (B8) represented by the formula (B8), [ Chemical formula 3] [ Chemical formula 4] In the formula (B1), rb 101 is a branched alkyl group having 4 to 20 carbon atoms, rb 201 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, rb 401 、Rb 501 、Rb 801 and Rb 901 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B2), rb 102 is a linear alkyl group having 4 to 20 carbon atoms, rb 202 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, rb 402 、Rb 502 、Rb 802 and Rb 902 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B3), rb 113 and Rb 213 are each independently a hydrogen atom, a linear alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a halogen atom, d is an integer of 7 to 15, and Rb 403 、Rb 503 、Rb 803 and Rb 903 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B4), rb 104 and Rb 204 are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, rb 404 、Rb 504 、Rb 804 and Rb 904 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B5), ar 105 is an aryl group having 6 to 12 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, rb 205 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, rb 405 、Rb 505 、Rb 805 and Rb 905 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B6), rb 116 and Rb 216 are each independently a hydrogen atom, a linear alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a halogen atom, e is an integer of 4 to 6, and Rb 406 、Rb 506 、Rb 806 and Rb 906 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In the formula (B7), rb 407 、Rb 507 、Rb 807 and Rb 907 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a halogen atom, In formula (B8), rb 408 、Rb 508 、Rb 808 and Rb 908 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom.
6. The electrophotographic photoreceptor according to any of claims 1 to 5, wherein, The polyarylate resin and the polycarbonate resin each have a structural unit comprising biphenyl represented by the following formula (BP), [ Chemical formula 5] In the formula (BP), j is an integer of 0 to 4, j R 1 are each independently methyl or ethyl, k is an integer of 0 to 4, and k R 2 are each independently methyl or ethyl.
7. The electrophotographic photoreceptor according to any of claims 1 to 6, wherein, The ratio of the polyarylate resin to the total amount of the polyarylate resin and the polycarbonate resin contained in the outermost layer is 25 mass% or more and 75 mass% or less.
8. The electrophotographic photoreceptor according to any of claims 1 to 7, wherein, The photosensitive layer has a charge generation layer and a charge transport layer, the charge transport layer being the outermost layer.
9. A process cartridge provided with the electrophotographic photoreceptor as claimed in any one of claim 1 to 8, The process cartridge is attached to and detached from the image forming apparatus.
10. An image forming apparatus includes: the electrophotographic photoreceptor of any one of claims 1 to 8; A charging device for charging a surface of the electrophotographic photoreceptor; An electrostatic latent image forming device that forms an electrostatic latent image on a surface of the charged electrophotographic photoreceptor; A developing device for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with a developer containing a toner to form a toner image, and And a transfer device for transferring the toner image to the surface of the recording medium.
11. The image forming apparatus according to claim 10, further comprising: And a cleaning device having a cleaning blade in contact with the surface of the electrophotographic photoreceptor and cleaning the surface of the electrophotographic photoreceptor.
12. The image forming apparatus according to claim 11, wherein, The contact portion of the cleaning blade with the electrophotographic photoreceptor is composed of a member containing a urethane rubber obtained by polymerizing at least a polyol component and a polyisocyanate component, and having a ratio M100/Re of 100% modulus M100 (MPa) to a modulus of resilience Re (%) of 0.25 or more, a modulus of resilience Re of less than 25%, and a tensile stress at 200% strain of 15MPa or more.
13. The image forming apparatus according to claim 12, wherein, The ratio M100/Re is 0.28 or more and 1.0 or less.

Description

Electrophotographic photoreceptor, process cartridge, and image forming apparatus Technical Field The invention relates to an electrophotographic photoreceptor, a process cartridge, and an image forming apparatus. Background Patent document 1 discloses an organic photoreceptor in which a charge generating layer and a charge transporting layer are laminated on a conductive support, wherein the charge transporting layer has a dielectric constant epsilon of 3.4 or less at a frequency of 20Hz and a dielectric loss tan delta of 0.001 to 0.03 at a frequency of 1 kHz. Patent document 2 discloses an electrophotographic photoreceptor in which a photosensitive layer contains a charge generating agent, a charge transporting agent, and a binder resin, and the binder resin contains a polyarylate resin and a polycarbonate resin. Patent document 3 discloses an electrophotographic photoreceptor including a conductive substrate and a layered photosensitive layer having a charge generation layer and a charge transport layer, wherein the charge transport layer contains a charge transport material, a polyarylate resin, and a polycarbonate resin. Patent document 4 discloses a cleaning blade in which a contact portion with a member to be cleaned is constituted of a member containing at least a urethane rubber obtained by polymerizing a polyol component and a polyisocyanate component, and in which a ratio M100/Re of 100% modulus M100 (MPa) to rebound modulus Re (%) is 0.25 or more, rebound modulus Re is less than 25%, and tensile stress at 200% strain is 15MPa or more. Patent document 1 Japanese patent laid-open publication No. 2003-131406 Patent document 2 Japanese patent application laid-open No. 2017-125878 Patent document 3 Japanese patent application laid-open No. 2024-01918 Patent document 4 Japanese patent application laid-open No. 2023-106209 Disclosure of Invention The invention provides an electrophotographic photoreceptor which is not easy to generate image defects even when used under high stress condition until the end of service life. Specific means for solving the above problems include the following means. The formulae are the same as those of the same numbers described below. <1> An electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer disposed on the conductive substrate, The outermost layer contains a charge transporting material, a polyarylate resin having a dicarboxylic acid unit represented by the formula (A) and a diol unit represented by the formula (B), a polycarbonate resin, and a phenol compound having 3 or less phenolic functional groups and a molecular weight of 300 or more, The dielectric loss tangent tan delta at the frequency of 1Hz of the outermost layer is 0.50 or less. <2> The electrophotographic photoreceptor according to <1>, wherein, The dielectric loss tangent tan delta of the outermost layer at a frequency of 1Hz is 0.40 or less. <3> The electrophotographic photoreceptor according to <1> or <2>, wherein, The phenol compound contains a phenol compound having 2 or less phenol functional groups and a molecular weight of 350 or more. <4> The electrophotographic photoreceptor according to any one of <1> to <3>, wherein, The dicarboxylic acid unit represented by the formula (a) includes at least one selected from the group consisting of a dicarboxylic acid unit (A1) represented by the formula (A1), a dicarboxylic acid unit (A2) represented by the formula (A2), a dicarboxylic acid unit (A3) represented by the formula (A3), a dicarboxylic acid unit (A4) represented by the formula (A4), and a dicarboxylic acid unit (A5) represented by the formula (A5). <5> The electrophotographic photoreceptor according to any one of <1> to <4>, wherein, The diol unit represented by the formula (B) includes at least one selected from the group consisting of a diol unit (B1) represented by the formula (B1), a diol unit (B2) represented by the formula (B2), a diol unit (B3) represented by the formula (B3), a diol unit (B4) represented by the formula (B4), a diol unit (B5) represented by the formula (B5), a diol unit (B6) represented by the formula (B6), a diol unit (B7) represented by the formula (B7), and a diol unit (B8) represented by the formula (B8). <6> The electrophotographic photoreceptor according to any one of <1> to <5>, wherein, The polyarylate resin and the polycarbonate resin each have a structural unit comprising biphenyl represented by formula (BP). <7> The electrophotographic photoreceptor according to any one of <1> to <6>, wherein, The ratio of the polyarylate resin to the total amount of the polyarylate resin and the polycarbonate resin contained in the outermost layer is 25 mass% or more and 75 mass% or less. <8> The electrophotographic photoreceptor according to any one of <1> to <7>, wherein, The photosensitive layer has a charge generation layer and a charge transport layer, the charge transport layer being the outermost layer. <9> A process cartridge co