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JP-7856213-B2 - Electrophotographic photoreceptor, method for manufacturing an electrophotographic photoreceptor, process cartridge, and image forming apparatus

JP7856213B2JP 7856213 B2JP7856213 B2JP 7856213B2JP-7856213-B2

Inventors

  • 寺岡 克矩
  • 窪嶋 大輔
  • 今中 祥貴
  • 宍戸 真
  • 清水 智文

Assignees

  • 京セラドキュメントソリューションズ株式会社

Dates

Publication Date
20260511
Application Date
20240520
Priority Date
20230323

Claims (15)

  1. An electrophotographic photoreceptor comprising a conductive substrate, a photosensitive layer, and a protective layer, The photosensitive layer contains a charge generating agent, a hole transporting agent, and a binder resin. The hole transporter has two or fewer chain-like ethene-1,2-diyl groups, or does not have chain-like ethene-1,2-diyl groups. The protective layer is the outermost layer of the electrophotographic photoreceptor and contains a photocurable resin. If the first absorbance of the protective layer, measured by Fourier transform infrared spectroscopy, is A and the second absorbance is B, then the ratio of the first absorbance to the second absorbance, A/B, is 0.160 or less. The first absorbance is the highest absorbance in the wavenumber range of 1627 cm⁻¹ to 1647 cm⁻¹ . The second absorbance is the highest absorbance in the range of wavenumbers greater than 1647 cm⁻¹ and less than or equal to 1800 cm⁻¹ . The photocurable resin comprises repeating units derived from (meth)acrylic acid ester and repeating units derived from urethane (meth)acrylate, wherein the (meth)acrylic acid ester has two to six vinyl groups, and is an electrophotographic photoreceptor.
  2. An electrophotographic photoreceptor comprising a conductive substrate, a photosensitive layer, and a protective layer, The photosensitive layer contains a charge generating agent, a hole transporting agent, and a binder resin. The hole transporter has two or fewer chain-like ethene-1,2-diyl groups, or does not have chain-like ethene-1,2-diyl groups. The protective layer is the outermost layer of the electrophotographic photoreceptor and contains a photocurable resin. If the first absorbance of the protective layer, measured by Fourier transform infrared spectroscopy, is A and the second absorbance is B, then the ratio of the first absorbance to the second absorbance, A/B, is 0.160 or less. The first absorbance is at wavenumber 1627 cm⁻¹. -1 The above is 1647 cm. -1 The highest absorbance is found within the following range: The second absorbance is at wavenumber 1647 cm⁻¹. -1 Super 1800cm -1 The highest absorbance is found within the following range: The hole transporter comprises at least one compound represented by formulas (1), (2), and (3) in an electrophotographic photoreceptor. (In formula (1) above, R 41 , R 42 , R 43 , R 44 , R 45 , and R 46 Each independently represents an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R 47 and R 48 Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and e 1 , e 2 , e 3 , and e 4 Each of these independently represents an integer between 0 and 5, and e 5 and e 6 Each of these independently represents an integer between 0 and 4, In the above formula (2), R 50 , R 51 , and R 54 Each independently represents an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R 52 , and R 53 Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group which may be substituted with an alkyl group having 1 to 8 carbon atoms, and f 3 , f 4 , and f 5 Each of these independently represents an integer of either 0 or 1. In the above formula (3), R 11 , R 12 , R 13 , and R 14 Each independently represents an alkyl group having 1 to 8 carbon atoms, or a phenyl group, a 1 a 2 a 3 , and a 4 Each of these independently represents an integer between 0 and 5 (inclusive).
  3. The electrophotographic photoreceptor according to claim 1 or 2 , wherein the ratio A/B is 0.100 or more and 0.160 or less.
  4. The electrophotographic photoreceptor according to claim 1, wherein the hole transporter comprises at least one of the compounds represented by formulas (1), (2), and (3). (In formula (1) above, R 41 , R 42 , R 43 , R 44 , R 45 , and R 46 each independently represent an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R 47 and R 48 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; e 1 , e 2 , e 3 , and e 4 each independently represent an integer between 0 and 5, and e 5 and e 6 each independently represent an integer between 0 and 4.) In formula (2), R 50 , R 51 , and R 54 each independently represent an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R 52 and R 53 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group which may be substituted with an alkyl group having 1 to 8 carbon atoms; and f 3 , f 4 , and f 5 each independently represent an integer between 0 and 5. In formula (3) above, R11 , R12 , R13 , and R14 each independently represent an alkyl group or phenyl group having 1 to 8 carbon atoms, and a1 , a2 , a3 , and a4 each independently represent an integer between 0 and 5.
  5. The aforementioned photocurable resin has a vinyl group and a carbonyl group, The first absorbance is the absorbance of the peak based on the vinyl group, The electrophotographic photoreceptor according to claim 2 , wherein the second absorbance is the absorbance of the peak based on the carbonyl group.
  6. The electrophotographic photoreceptor according to claim 2 , wherein the photocurable resin contains repeating units derived from a (meth)acrylic acid ester, and the (meth)acrylic acid ester has two to six vinyl groups.
  7. The electrophotographic photoreceptor according to claim 6 , wherein the content of repeating units derived from the (meth)acrylic acid ester in relation to the total repeating units of the photocurable resin is 60% by mass or more.
  8. The electrophotographic photoreceptor according to claim 1 or 2 , wherein the protective layer further contains two types of metal oxides.
  9. The electrophotographic photoreceptor according to claim 8, wherein one of the two metal oxides is alumina.
  10. The electrophotographic photoreceptor according to claim 9, wherein the other of the two metal oxides is phosphorus-doped tin oxide or antimond-doped tin oxide.
  11. The electrophotographic photoreceptor according to claim 1 or 2 , wherein the thickness of the protective layer is 2 μm or more.
  12. The electrophotographic photoreceptor according to claim 1 or 2 , wherein the charge generating agent contained in the photosensitive layer comprises titanyl phthalocyanine or metal-free phthalocyanine.
  13. The process includes forming a protective layer containing the photocurable resin on the photosensitive layer, A method for producing an electrophotographic photoreceptor according to claim 1 or 2, wherein in the protective layer formation step, the photocurable resin is formed by irradiating at least one of the monomer and oligomer on the photosensitive layer with ultraviolet light to polymerize at least one of the monomer and oligomer .
  14. At least one selected from the group consisting of a charging device, an exposure device, a developing device, a transfer device, a cleaning member, a friction roller, and a static elimination device, A process cartridge comprising an electrophotographic photoreceptor according to claim 1 or 2 .
  15. Image carrier and, A charging device for charging the surface of the image carrier, An exposure apparatus for exposing the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier, A developing apparatus that supplies toner to the surface of the image carrier and develops the electrostatic latent image as a toner image, The system comprises a transfer device for transferring the toner image from the image carrier to the transfer target, An image forming apparatus wherein the image carrier is an electrophotographic photoreceptor according to claim 1 or 2 .

Description

This invention relates to an electrophotographic photoreceptor, a method for manufacturing an electrophotographic photoreceptor, a process cartridge, and an image forming apparatus. When images are repeatedly formed using an image forming apparatus equipped with an electrophotographic photoreceptor, the electrophotographic photoreceptor may gradually wear down. To suppress wear and extend the lifespan of the electrophotographic photoreceptor, a hard protective layer may be provided on the surface of the electrophotographic photoreceptor. For example, the electrophotographic photoreceptor described in Patent Document 1 has a photosensitive layer on a conductive support containing a charge generating material and a charge transporting material in the same layer. A protective layer is provided on the photosensitive layer. The volume resistivity of the protective layer is smaller than the volume resistivity of the photosensitive layer. Japanese Patent Publication No. 2010-286707 This is a partial cross-sectional view of a single-layer electrophotographic photoreceptor, which is an example of an electrophotographic photoreceptor according to the first embodiment of the present invention.This is a partial cross-sectional view of a single-layer electrophotographic photoreceptor, which is an example of an electrophotographic photoreceptor according to the first embodiment of the present invention.This is a partial cross-sectional view of a stacked electrophotographic photoreceptor, which is an example of an electrophotographic photoreceptor according to the first embodiment of the present invention.This is a partial cross-sectional view of a stacked electrophotographic photoreceptor, which is an example of an electrophotographic photoreceptor according to the first embodiment of the present invention.This is a partial cross-sectional view of a stacked electrophotographic photoreceptor, which is an example of an electrophotographic photoreceptor according to the first embodiment of the present invention.This is the absorption spectrum of the protective layer of the photoreceptor according to Example 2, measured by Fourier transform infrared spectroscopy.This is the absorption spectrum of a hole transporter before and after irradiation with a predetermined ultraviolet light, measured by ultraviolet-visible spectroscopy. This hole transporter is contained in the photosensitive layer of the photoreceptor according to Example 4.This figure shows an example of an image forming apparatus according to a third embodiment of the present invention.Figure 8 shows an example of the configuration of a developing apparatus. The embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below and can be implemented with appropriate modifications within the scope of the object of the present invention. Acrylic and methacrylate are sometimes collectively referred to as "(meth)acrylic." Acrylate and methacrylate are sometimes collectively referred to as "(meth)acrylate." Acryloyl and methacryloyl are sometimes collectively referred to as "(meth)acryloyl." Unless otherwise specified, the hydroxyl value is the value measured according to "JIS (Japanese Industrial Standards) K0070-1992." Unless otherwise specified, the number-mean primary particle diameter is the number-average value of the equivalent circle diameter (Heywood diameter: the diameter of a circle having the same area as the projected area of the primary particle) of primary particles measured using a scanning electron microscope. For example, the number-mean primary particle diameter is the number-average value of the equivalent circle diameter of 100 primary particles. Unless otherwise specified, the BET specific surface area is the value measured by the BET method using nitrogen adsorption, in accordance with "JIS (Japanese Industrial Standards) Z8830:2001 Method for measuring the specific surface area of powders (solids) by gas adsorption." The term "system" may be added after a compound name to comprehensively refer to the compound and its derivatives. Similarly, when "system" is added after a compound name to represent a polymer name, it means that the repeating units of the polymer originate from the compound or its derivatives. Furthermore, "general formula" and "chemical formula" are collectively referred to as "formula." In the description of a formula, "each independently" means that they may represent the same group or different groups. Unless otherwise specified, each component described herein may be used alone or in combination of two or more. For example, "at least one of A, B, and C" and "at least one of A, B, and C" are synonymous with "at least one selected from the group consisting of A, B, and C." "at least one of A, B, and C" and "at least one of A, B, and C" are synonymous with "at least one selected from the group consisting of A, B, and C." Note that A, B, and C