CN-122018263-A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus

CN122018263ACN 122018263 ACN122018263 ACN 122018263ACN-122018263-A

Abstract

An electrophotographic photoreceptor, a process cartridge, and an image forming apparatus, wherein the electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer disposed on the conductive substrate, wherein the outermost layer includes first and second resins, a charge transporting material, and an antioxidant, at least one of the first and second resins has a structural unit including biphenyl represented by the following formula (BPa), and at least one of the charge transporting material and the antioxidant has at least one of biphenyl represented by the following formula (BPa) and biphenyl represented by the following formula (BPb) in a molecule, and a relationship of 0.0 (BP 1×Mp1+BP2)/(BP 3×Mp3+B4XMp4) < 3.0 is satisfied when the number of biphenyls per unit molecular weight of each of the first and second resins, the charge transporting material, and the antioxidant is BP1, BP2, BP3, and BP4, and the respective proportions of the total amount are MP1, MP2, MP3, and MP 4. [ chemical formula 1] formula (BPa) Formula (BPb)

Inventors

Kusano Kawoo
IDE KENTA
KANO FUYUKI
Kiko Youchi
OYAMADA YUKI
GAO YANGPING

Assignees

富士胶片商业创新有限公司

Dates

Publication Date: 20260512
Application Date: 20250930
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 first resin, a second resin, a charge transport material and an antioxidant, At least one of the first resin and the second resin has a structural unit containing biphenyl represented by the following formula (BPa), At least one of the charge transport material and the antioxidant has at least one of biphenyl represented by the following formula (BPa) and biphenyl represented by the following formula (BPb) in a molecule, When the numbers of biphenyls per unit molecular weight of the first resin, the second resin, the charge transport material, and the antioxidant are BP1, BP2, BP3, and BP4, and the proportions (mass%) of the biphenyls in the total amount of the first resin, the second resin, the charge transport material, and the antioxidant are MP1, MP2, MP3, and MP4, Satisfies the relationship of (Bp1×Mp1+Bp2×Mp2)/(Bp3×Mp3+Bp4×Mp4) less than or equal to 0.0 and less than or equal to 3.0, [ Chemical formula 1] (BPa) (BPb) In the formula (BPa), 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, k R 2 are each independently methyl or ethyl, Multiple methyl and/or ethyl groups may be bonded to form a ring, In the formula (BPb), m is an integer of 0 to 4, m R 3 are each independently methyl or ethyl, n is an integer of 0 to 5, n R 4 are each independently methyl or ethyl, Multiple methyl and/or ethyl groups may be bonded to form a ring.
2. The electrophotographic photoreceptor according to claim 1, wherein, Satisfies the relationship of (Bp1×Mp1+Bp2×Mp2)/(Bp3×Mp3+Bp4×Mp4) being less than or equal to 0.5 and less than or equal to 2.5.
3. The electrophotographic photoreceptor according to claim 1 or 2, wherein, The antioxidant comprises a hindered phenol compound.
4. The electrophotographic photoreceptor according to any of claim 1 to 3, wherein, The first resin is a polyarylate resin, and the second resin is a polycarbonate resin.
5. The electrophotographic photoreceptor according to claim 4, 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.
6. The electrophotographic photoreceptor according to claim 4 or 5, wherein, The polyarylate resin has 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 following formula (A3), a dicarboxylic acid unit (A4) represented by the following formula (A4), and a dicarboxylic acid unit (A5) represented by the following formula (A5), [ Chemical formula 2] (A1) (A2) (A3) (A4) (A5) 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.
7. The electrophotographic photoreceptor according to any of claims 4 to 6, wherein, The polyarylate resin has 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 following formula (B3), a diol unit (B4) represented by the following formula (B4), a diol unit (B5) represented by the following formula (B5), a diol unit (B6) represented by the following formula (B6), a diol unit (B7) represented by the following formula (B7) and a diol unit (B8) represented by the following formula (B8), [ Chemical formula 3] (B1) (B2) (B3) (B4) [ Chemical formula 4] (B5) (B6) (B7) (B8) 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.
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 electrophotographic photoreceptor including a polyester resin having a biphenyl structure as a repeating unit in a photosensitive layer. Patent document 2 discloses a photoreceptor containing at least one of a polyester resin having a structural unit having an aromatic ring and a polycarbonate resin having a structural unit having an aromatic ring in a charge transport layer. Patent document 3 discloses an electrophotographic photoreceptor in which a charge transport layer contains a charge transport material, a polyester resin having a predetermined aromatic structure, and a polycarbonate resin. Patent document 4 discloses a cleaning blade in which a contact portion with a member to be cleaned contains a urethane rubber obtained by polymerizing at least a polyol component and a polyisocyanate component, and the ratio M100/Re of 100% modulus M100 (MPa) to modulus of elasticity Re (%) is 0.25 or more, the modulus of elasticity Re is less than 25%, and the tensile stress at 200% strain is 15MPa or more. Patent document 1 Japanese patent laid-open No. 2001-265021 Patent document 2 Japanese patent application laid-open No. 2023-121553 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 ghost and uneven concentration in an image. 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 first resin, a second resin, a charge transport material and an antioxidant, At least one of the first resin and the second resin has a structural unit containing biphenyl represented by the following formula (BPa), At least one of the charge transport material and the antioxidant has at least one of biphenyl represented by the following formula (BPa) and biphenyl represented by the following formula (BPb) in a molecule, When the numbers of biphenyls per unit molecular weight of the first resin, the second resin, the charge transport material, and the antioxidant are BP1, BP2, BP3, and BP4, and the proportions (mass%) of the biphenyls in the total amount of the first resin, the second resin, the charge transport material, and the antioxidant are MP1, MP2, MP3, and MP4, Meets the requirement of 0.0-0 (Bp1X1Mp1+Bp2X1Mp2)/[ the ratio ] relationship of BP3 xMp3+BP 4 xMp4). Ltoreq.3.0. <2> The electrophotographic photoreceptor according to <1>, wherein, Satisfies the relationship of (Bp1×Mp1+Bp2×Mp2)/(Bp3×Mp3+Bp4×Mp4) being less than or equal to 0.5 and less than or equal to 2.5. <3> The electrophotographic photoreceptor according to <1> or <2>, wherein, The antioxidant comprises a hindered phenol compound. <4> The electrophotographic photoreceptor according to any one of <1> to <3>, wherein, The first resin is a polyarylate resin, and the second resin is a polycarbonate resin. <5> The electrophotographic photoreceptor according to <4>, 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. <6> The electrophotographic photoreceptor according to <4> or <5>, wherein, The polyarylate resin has at least one selected from the group consisting of a dicarboxylic acid unit (A1) represented by formula (A1), a dicarboxylic acid unit (A2) represented by formula (A2), a dicarboxylic acid unit (A3) represented by formula (A3), a dicarboxylic acid unit (A4) represented by formula (A4), and a dicarboxylic acid unit (A5) represented by formula (A5). <7> The electrophotographic photoreceptor according to any one of <4> to <6>, wherein, The polyarylate resin has at least one selected from the group consisting of a diol unit (B1) represented by formula (B1), a diol unit (B2) represented by formula (B2), a diol unit (B3) represented by formula (B3), a diol unit (B4) represented by formula (B4), a diol unit (B5) represented by formula (B5), a diol unit (B6) represented by formula (B6), a diol unit (B7) represented by formula (B7), and a diol unit (B8) represented by formula (B8). <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 comprising an electrophotographic photoreceptor according to any one of <1> to <8>, The pr