JP5434246B2 - Electrophotographic photosensitive member, and electrophotographic method, electrophotographic apparatus and process cartridge using the electrophotographic photosensitive member - Google Patents

Description

The present invention relates to an electrophotographic photosensitive member used for an electrophotographic printer, a copying machine, etc., and is excellent in responsiveness, compatible with high speed machines, and excellent in durability and ozone resistance and NOx resistance. The present invention relates to an electrophotographic photoreceptor having a property.
The present invention also relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus using the electrophotographic photosensitive member.

  An electrophotographic photoreceptor (hereinafter sometimes referred to as “photoreceptor”) has a function of holding surface charges in the dark, a function of receiving light to generate charges, and a function of receiving light to transport charges. A single layer type photoconductor that combines these functions in a single layer, a layer that mainly contributes to charge generation, surface charge retention in the dark, and charge transfer during photoreception There is a so-called function-separated stacked type photoreceptor in which a layer that has been function-separated is laminated on a layer that contributes to the above.

  For example, a Carlson method is applied to image formation by electrophotography using these photoreceptors. Image formation by this method is performed by charging a photoconductor in a dark place by corona discharge, forming an electrostatic latent image such as text or a picture of an original on the surface of the charged photoconductor, The image is developed by toner, and the developed toner image is transferred and fixed to a support such as paper. After the toner image is transferred, the photoconductor is subjected to charge removal, residual toner removal, light charge removal, etc. Provided for use.

  In recent years, electrophotographic photoreceptors using organic substances have been put into practical use due to advantages such as flexibility, thermal stability, and film formability. Recently, a function-separated laminated type photoreceptor comprising a charge generation layer containing a charge generation agent and a charge transfer layer containing a charge transfer agent has become the mainstream as a photosensitive layer. Among these functionally separated laminated photoreceptors, a layer in which an organic pigment is vapor-deposited as a charge generating agent or a layer dispersed in a resin is used as a charge generating layer, and a layer in which an organic low molecular weight compound is dispersed in a resin as a charge transfer agent A number of negatively charged photoreceptors using a photoconductive layer as a charge transfer layer have been proposed.

  Organic materials have many advantages not found in inorganic materials, but at the same time, organic materials that sufficiently satisfy all the characteristics required for electrophotographic photoreceptors have not been obtained. That is, image quality is deteriorated due to a decrease in charging potential, an increase in residual potential, a change in sensitivity, etc. due to repeated use. Although not all of the causes of this deterioration have been elucidated, as one of the factors, oxidizing gases such as ozone and NOx released from corona discharge chargers, and oxidizing gases such as ozone and NOx in the atmosphere Has been found to cause significant damage to the photosensitive layer. In other words, these oxidizing gases cause various changes in properties by causing a chemical change with the material in the photoreceptor or by forming an adsorbate on the surface of the photosensitive layer. Causes increase in potential and decrease in resolution due to decrease in surface resistance. As a result, the image quality is remarkably deteriorated and the life of the photoreceptor is shortened. As a countermeasure against these problems, proposals have been made to prevent deterioration by adding an antioxidant or a stabilizer to the photosensitive layer. For example, as represented by Patent Document 1, many additions of hindered phenol-based antioxidants and hindered amine-based antioxidants have been proposed. Other examples of addition of amine derivatives include Patent Document 2, Patent Document 3, or Patent Document 4. These proposals had a certain effect.

  However, in recent years, the demand for high durability and high responsiveness has increased for photoreceptors due to demands for high speed and downsizing of copiers or printers. In order to cope with this high responsiveness, It is necessary to use a charge transfer agent having a low ionization potential (Ip) value. However, these charge transfer agents have poor durability against ozone and NOx, and the addition of conventional antioxidants and the like has become insufficient.

The present invention has been made in view of the above points, and an object thereof is to provide an electrophotographic photosensitive member having high responsiveness, high ozone resistance and NOx resistance, and high durability.
Another object of the present invention is to use the electrophotographic photosensitive member, which eliminates the need for replacement of the photosensitive member and realizes downsizing of the apparatus accompanying high-speed printing or reducing the diameter of the photosensitive member. An object of the present invention is to provide an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus that can stably obtain a high-quality image.

In order to solve the above problems, the electrophotographic photoreceptor according to the present invention, the electrophotographic method using the electrophotographic photoreceptor, the electrophotographic apparatus, and the process cartridge for the electrophotographic apparatus are specifically described in the following (1) to (1) to It has the technical features described in (8).
(1): a conductive support and a photosensitive layer provided on the conductive support, the photosensitive layer comprising a charge generating agent and a charge transfer agent represented by the following general formula (I) And an amine compound represented by the following general formula (II).

[In the above formula (I), R _{1 to} R ₃ each independently represent hydrogen, a halogen atom, or an optionally substituted alkyl group having 1 to 6 carbon atoms, and n = 1 . ]

[In the above formula (II), A and B are each independently a group represented by the following formula (i) or the following formula (ii), and may be the same or different.
—CH ₂ X Formula (i)
—CH ₂ CH ₂ Y Formula (ii)
However, X and Y each independently represent an aromatic residue, and these may have a substituent. ]

  By having the configuration described in (1) above, it has excellent electrical characteristics and is emitted from corona discharge chargers such as ozone and NOx, or atmospheric gases such as ozone and NOx. Damage to the photosensitive layer due to is significantly reduced.

(2): A charging step for charging the surface of the electrophotographic photosensitive member according to (1), an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image. The electrophotographic method is characterized by repeatedly performing a developing step for forming a toner image and a transfer step for transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member.

(3): A charging step for charging the surface of the electrophotographic photosensitive member according to (1), an image exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member, and developing the electrostatic latent image. The development process for forming a toner image and the transfer process for transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member are repeated, and the image exposure process is performed by means of an LD or LED. The present invention is a digital electrophotographic method characterized by forming an electrostatic latent image.

(4): The electrophotographic photosensitive member according to (1) above, a charging unit for charging the surface of the electrophotographic photosensitive member, an image exposing unit for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, A developing unit that develops an electrostatic latent image to form a toner image; and a transfer unit that directly transfers the toner image to a recording material or transfers the toner image to a recording material via an intermediate transfer member. An electrophotographic apparatus.

(5): The electrophotographic photosensitive member according to (1), a charging unit that charges the surface of the electrophotographic photosensitive member, an image exposure unit that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member, A developing unit that develops an electrostatic latent image to form a toner image; and a transfer unit that directly transfers the toner image to a recording material or transfers the toner image to the recording material via an intermediate transfer member, and the image exposure. The means is a digital electrophotographic apparatus characterized by being an LD or an LED.

(6) The electrophotographic apparatus according to (4) or (5), wherein the electrophotographic photosensitive member is a tandem type having a plurality of the electrophotographic photosensitive member, the charging unit, the developing unit, and the transfer unit. It is.

(7): An intermediate transfer member and an intermediate transfer unit are further provided, and the transfer unit primarily transfers the toner image formed on the electrophotographic photosensitive member to the intermediate transfer member and then onto the intermediate transfer member. Forming an image, the intermediate transfer unit secondarily transfers the image on the intermediate transfer member onto the recording material, and when the image on the intermediate transfer member is a color image composed of a plurality of colors of toner, the transfer unit includes: The intermediate transfer member forms an image on the intermediate transfer member by sequentially superimposing the colors on the intermediate transfer member, and the intermediate transfer unit performs secondary transfer of the intermediate transfer member on the recording material at once. The electrophotographic apparatus according to any one of (4) to (6) above.

(8): The electrophotographic photosensitive member according to the above (1), charging means for charging the surface of the electrophotographic photosensitive member, image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member, the electrostatic Developing means for developing a latent image to form a toner image, cleaning means for cleaning the surface of the electrophotographic photosensitive member, and transferring means for directly transferring the toner image to a recording material or transferring it to the recording material via an intermediate transfer member And a process cartridge for an electrophotographic apparatus, comprising at least one selected from the above.

According to the present invention, it is possible to provide an electrophotographic photosensitive member in which electrophotographic characteristics such as charging, sensitivity, and residual potential are stabilized and the life is remarkably improved.
According to the present invention, by using the electrophotographic photosensitive member, it is not necessary to replace the photosensitive member, and it is possible to reduce the size of the apparatus associated with high-speed printing or a reduction in the diameter of the photosensitive member. It is possible to provide an electrophotographic method, an electrophotographic apparatus, and a process cartridge capable of stably obtaining a quality image.

1 is a cross-sectional view showing a negatively charged function-separated electrophotographic photoreceptor according to an embodiment of the present invention. 1 is a cross-sectional view showing a positively charged single layer type electrophotographic photoreceptor according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing the configuration of a first embodiment of an electrophotographic apparatus according to the present invention. It is a cross-sectional schematic diagram which shows the structure in 2nd Embodiment of the electrophotographic apparatus which concerns on this invention. It is a cross-sectional schematic diagram which shows the structure in 3rd Embodiment of the electrophotographic apparatus which concerns on this invention. It is a cross-sectional schematic diagram which shows the structure in 4th Embodiment of the electrophotographic apparatus which concerns on this invention. 1 is a schematic cross-sectional view showing a configuration of an embodiment of a process cartridge according to the present invention. It is an X-ray-diffraction spectrum figure of the oxytitanium phthalocyanine used in the Example. It is a figure for demonstrating the printing pattern of 2by2 employ | adopted in the Example.

  An electrophotographic photosensitive member according to the present invention, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic apparatus, and a process cartridge include a conductive support, a photosensitive layer provided on the conductive support, And the photosensitive layer contains a charge generating agent, a charge transfer agent represented by the following general formula (I), and an amine compound represented by the following general formula (II). .

[In the above formula (I), R _{1 to} R ₃ each independently represent hydrogen, a halogen atom, or an optionally substituted alkyl group having 1 to 6 carbon atoms, and n = 1 or 2 is there. ]

[In the above formula (II), A and B are each independently a group represented by the following formula (i) or the following formula (ii), and may be the same or different.

—CH ₂ X Formula (i)
—CH ₂ CH ₂ Y Formula (ii)

  However, X and Y each independently represent an aromatic residue, and these may have a substituent. ]

[Electrophotographic photoconductor]
Next, the electrophotographic photoreceptor according to the present invention will be described in more detail.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached thereto, but the scope of the present invention is intended to limit the present invention in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

  FIG. 1 is a cross-sectional view showing a negatively charged function-separated electrophotographic photoreceptor according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a mainly positively charged single-layer type electrophotographic photoreceptor according to an embodiment of the present invention. 30 is a conductive support, 31 is an undercoat layer, 32 is a charge generation layer, 33 is a charge transfer layer, 34 is a function-separated photosensitive layer comprising the charge generation layer 32 and the charge transfer layer 33, and 34a is a single layer. A photosensitive layer of the mold.

(Conductive support)
The conductive support 30 serves as a support for each of the other layers as well as serving as an electrode of the photoreceptor, and may be any shape such as a cylinder, a plate, or a film.
Examples of the material of the conductive support 30 include, for example, aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, indium, and the like, as well as alloys thereof, Examples thereof include those obtained by conducting a conductive treatment on glass, resin or the like.

(Underlayer)
The undercoat layer 31 is made of a resin-based layer or an anodized oxide film such as alumite, and prevents unnecessary charge injection from the conductive support 30 to the photosensitive layers 34 and 34a, and defects on the surface of the conductive support 30. It is provided as necessary for the purpose of covering, improving adhesion to the photosensitive layers 34 and 34a, and the like.
As the resin (resin binder) as the main component of the undercoat layer 31, polyethylene, polypropylene, polystyrene, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyurethane resin, epoxy resin, polyester resin, melamine resin, silicon resin, polybutyral Resins, polyamide resins, polyimide resins, copolymers thereof, and the like can be used in appropriate combinations. The resin binder may contain metal oxide fine particles. As the metal oxide fine particles, SiO ₂ , TiO ₂ , In ₂ O ₃ , ZrO ₂ or the like can be used.

  The film thickness of the undercoat layer 31 depends on the composition of the undercoat layer, but can be arbitrarily set within a range where no adverse effect such as an increase in residual potential occurs when repeatedly used. Generally, the range is 0.1 μm to 50 μm, preferably 0.5 μm to 20 μm.

(Charge generation layer)
The charge generation layer 32 is formed by vacuum-depositing an organic photoconductive substance or by applying a coating liquid in which particles of the organic photoconductive substance are dispersed in a resin binder, and receives light to generate a charge. To do. At the same time as the charge generation efficiency is high, the injection property of the generated charges into the charge transfer layer 33 is important, and it is desirable that the injection property is good even in a low electric field with little electric field dependency.
Since the charge generation layer 32 only needs to have a charge generation function, the film thickness is determined by the light absorption coefficient of the charge generation agent, and is generally 5 μm or less, and preferably 1 μm or less. The charge generation layer 32 can also be used with a charge transfer agent as a main component and a charge transfer agent added thereto. As the charge generator, phthalocyanine pigments such as metal-free phthalocyanine, titanyl phthalocyanine, tin phthalocyanine, azo pigments, anthanthrone pigments, perylene pigments, perinone pigments, squarylium pigments, thiapyrylium pigments, quinacridone pigments, and the like can be used. These pigments may be used in combination.

  Resin binders used for the preparation of the coating liquid include polycarbonate resin, polyester resin, polyamide resin, polyurethane resin, epoxy resin, polyvinyl butyral resin, polyvinyl acetal resin, vinyl chloride resin, phenoxy resin, silicone resin, methacrylic resin. Acid ester resins and copolymers thereof can be used in appropriate combinations.

(Charge transfer layer)
The charge transfer layer 33 is a film in which a charge transfer agent is dispersed in a resin binder. The charge transfer layer 33 retains the charge of the photoreceptor as an insulator layer in the dark, and transports the charge injected from the charge generation layer 32 when receiving light. Demonstrate the function to do. The charge transfer layer 33 includes a charge transfer agent, a resin binder, and various additives as main components.

  The photosensitive layers 34 and 34a of the electrophotographic photoreceptor of the present invention contain a charge transfer agent represented by the general formula (I) as a charge transfer agent and an amine compound represented by the general formula (II) as an additive. The

In the above formula (I), R _{1 to} R ₃ each independently represent hydrogen, a halogen atom, or an optionally substituted alkyl group having 1 to 6 carbon atoms, and n = 1 or 2. .
More preferably, R _{1 to} R ₃ are each independently hydrogen or a methyl group.

In the above formula (II), A and B are each independently a group represented by the following formula (i) or the following formula (ii), and may be the same or different.
—CH ₂ X Formula (i)
—CH ₂ CH ₂ Y Formula (ii)
However, X and Y each independently represent an aromatic residue, and these may have a substituent.
The X and Y are more preferably each independently a phenyl group or a tolyl group.

  The electrophotographic photosensitive member according to the present invention corresponding to the reduction in diameter and high-speed printing contains the charge transfer agent having high mobility in the photosensitive layers 34 and 34a.

  In the charge transfer agent represented by the general formula (I), the compounds represented by the following chemical formulas (Ia) to (Ih) are particularly preferable because they are excellent in various properties for miniaturization and high-speed printing. Specific compounds are shown below, but the present invention is not limited thereto.

  The additive prevents deterioration of the electrophotographic photosensitive member due to ozone and NOx, and contributes to a longer life.

  Among the compounds represented by the general formula (II), the compounds represented by the following chemical formulas (IIa) to (IIe) are particularly preferable because they have excellent ability to prevent deterioration due to ozone and NOx. Specific compounds are shown below, but the present invention is not limited thereto.

  In this case, the content of the charge transfer agent represented by the general formula (I) in the charge transfer layer 33 is preferably 0.3 to 2.0 parts by mass with respect to 1 part by mass of the resin binder. If the content of the charge transfer agent represented by the general formula (I) is less than 0.3 parts by mass, the electrical characteristics deteriorate, for example, the residual potential increases. On the other hand, when the amount is more than 2.0 parts by mass, mechanical properties such as wear resistance deteriorate.

  Furthermore, the charge transfer agent represented by the general formula (I) and other charge transfer agents can be mixed and used. In this case, the content ratio of the charge transfer agent represented by the general formula (I) and the other charge transfer agent is on a weight basis, (charge transfer agent represented by the general formula (I)): (other charge The transfer agent) is preferably in the range of 50:50 to 95: 5, more preferably in the range of 70:30 to 95: 5.

  Other charge transfer agents include trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone or their derivatives, polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, indole, carbazole Nitrogen-containing heterocyclic compounds such as imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, triphenylmethane, triphenylamine, enamine, stilbene or butadiene compounds can be used. When attention is paid to high responsiveness for these compounds, the molecular weight is preferably 600 or more. Further, even if only one of these is added or two or more compounds are mixed and added, desired photoreceptor characteristics can be obtained.

  Further, the content of the amine compound represented by the general formula (II) in the charge transfer layer 33 may be 0.01 to 0.30 parts by mass of the amine compound with respect to 1 part by mass of the charge transfer agent. preferable. When the content of this compound is less than 0.01 parts by mass, a decrease in charging due to the influence of ozone and NOx and image blurring are remarkable. On the other hand, when the content is more than 0.30 parts by mass, the residual potential increases. .

  Examples of the charge transfer layer resin binder include polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, chlorinated polyether resin, vinyl chloride-vinyl acetate resin, Polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin, polyallylsulfone resin, silicone Resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, EVA (ethylene / vinyl acetate / copolymer) resin, ACS (acrylonitrile / chlorinated polyethylene / polymer) Resins such as photopolymerization resins such as (ethylene) resin, ABS (acrylonitrile butadiene styrene) resin, and epoxy arylate. These may be used alone or as a copolymer, or may be used in a mixture of two or more. It is preferable to use a mixture of resins having different molecular weights because the hardness and wear resistance can be improved.

In addition to the mechanical, chemical and electrical stability, adhesion, etc., the resin binder for the charge transfer layer is important for compatibility with the charge transfer agent.
The film thickness of the charge transfer layer 33 is preferably in the range of 3 to 50 μm, more preferably 10 to 40 μm in order to maintain a practically effective surface potential.

The film thickness of the single-layer type photosensitive layer 34a is preferably in the range of 3 to 50 [mu] m, more preferably 10 to 40 [mu] m, in order to maintain a practically effective surface potential.
Here, the single-layer type photosensitive layer 34a is a layer in which a charge generating agent and a charge transfer agent are dispersed in a resin binder, and one layer has both functions of charge generation and charge transfer. In the single-layer type photosensitive layer 34a, the materials (charge generation agent, charge transfer agent, resin binder) used for the above-described laminated type photosensitive layer (charge generation layer 32, charge transfer layer 33) are used in the same manner. Can do.

  In the case of the single-layer type photosensitive layer 34a, it is preferable to use an electron transfer agent as another charge transfer agent for high sensitivity. Examples of the electron transfer agent include trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone, and derivatives thereof, and polycyclic aromatic compounds such as anthracene, pyrene, and phenanthrene.

In the single-layer type photosensitive layer 34a, the charge generating material is suitably 0.1 to 30% by mass, preferably 0.5 to 5% by mass with respect to the entire photosensitive layer 34a. When the concentration of the charge generating material is low, the photoreceptor sensitivity tends to decrease, and when the concentration is high, the chargeability and film strength tend to decrease.
The content of the charge transfer agent represented by the general formula (I) is preferably 0.3 to 2.0 parts by mass with respect to 1 part by mass of the resin binder. Moreover, it is preferable that content of an electron transfer agent shall be 0.3-2.0 mass parts with respect to 1 mass part of resin binders.
Moreover, it is preferable that content of the amine compound represented by the said general formula (II) shall be 0.01-0.30 mass part of amine compounds with respect to 1 mass part of charge transfer agents.

  In the coating solution for producing the electrophotographic photosensitive member of the present invention, an antioxidant, an ultraviolet absorber, a radical scavenger, a softener, a curing agent, a crosslinking agent, etc. are added as long as the characteristics are not impaired. The characteristics, durability, and mechanical characteristics of the photoreceptor can be improved. In particular, the use of an antioxidant and an ultraviolet absorber in combination with the amine compound represented by the general formula (II) used in the present invention may further contribute to the improvement of the durability of the photoreceptor. Among them, the photosensitive layers 34 and 34a are preferably phenolic antioxidants, amine-based antioxidants, sulfur-based antioxidants, and benzotriazole-based ultraviolet absorbers.

  For example, phenolic antioxidants are 2,6-di-tert-butylphenol, 2,6-di-tert-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6. Tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl propionate-β- (3,5-di-tert-butyl-4-hydroxyphenyl), α- Monophenols such as tocopherol, β-tocopherol, n-octadecyl-3- (3′-5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2,2′-methylenebis (6-tert-butyl) -4-methylphenol), 4,4'-butylidene-bis- (3-methyl-6-tert) Butylphenol), 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3 , 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) ) Propionate] Polyphenols such as methane can be mentioned, and one or more of these can be simultaneously contained in the photosensitive layers 34 and 34a.

  For example, amine antioxidants include N-phenyl-1-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine, N, N-diethyl-p-phenylenediamine, N-phenyl-N′-ethyl. -2-methyl-p-phenylenediamine, N-ethyl-N-hydroxyethyl-p-phenylenediamine, alkylated diphenylamine, N, N'-diphenyl-p-phenylenediamine, N, N'-diallyl-p-phenylene Diamine, N-phenyl-1,3-dimethylbutyl-p-phenylenediamine, 4,4′-dioctyl-diphenylamine, 4,4′-dioctyl-diphenylamine, 6-ethoxy-2,2,4-trimethyl-1, 2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline, N-fluoro Nyl-β-naphthylamine, N, N′-di-2-naphthyl-p-phenylenediamine and the like can be mentioned, and one or more of these can be simultaneously contained in the photosensitive layers 34 and 34a. .

Sulfur-based antioxidants include dilauryl-3,3-thiodipropionate, ditridecyl-3,3-thiodipropionate, dimyristyl-3,3-thiodipropionate, distearyl-3,3-thiodipropioate. sulfonates, lauryl stearyl 3,3-thiodipropionate, bis [2-methyl -4- (3-n- alkyl _C 12 _{-C 14)} thiopropionate) -5-t-butylphenyl] sulfide, pentamethylene Examples include erythritol tetra (β-lauryl-thiopropionate) ester, 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, and the like. It can be contained in 34a.

  For example, as an ultraviolet absorber, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- ( 3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy -5'-tert-octylphenyl) benzotriazoles such as benzotriazole, phenyl salicylate, salicy Salicylic acid systems such as oxalic acid-p-tert-butylphenyl and salicylic acid-p-octylphenyl are preferred. Of these, benzotriazole-based ultraviolet absorbers are particularly preferred.

  The addition amount of the antioxidant and the ultraviolet absorber added to the electrophotographic photoreceptor of the present invention is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the charge transfer agent.

  Furthermore, the addition of a dispersion stabilizer, an anti-settling agent, an anti-coloring agent, a leveling agent, an antifoaming agent, a thickener, a matting agent, etc. can improve the finished appearance of the photoreceptor and the life of the coating solution.

  Further, in the photosensitive layers 34 and 34a of the above-mentioned laminated type and single layer type photoreceptors, an electron accepting material is contained as necessary for the purpose of improving sensitivity, reducing residual potential, or reducing characteristic fluctuations during repeated use. Can be made. Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyromellitic anhydride, pyromellitic acid, trimellitic acid, Examples include compounds having a large electron affinity such as trimellitic anhydride, phthalimide, 4-nitrophthalimide, tetracyanoethylene, tetracyanosinodimethane, chloranil, bromanyl, o-nitrobenzoic acid.

  Solvents used in the coating solution include alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, toluene and xylene. Aromatic hydrocarbons such as dichloromethane, chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran (THF), methoxyethanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone , Esters such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, N, N-dimethylformamide, dimethylsulfoxy And the like. These may be used alone or as a mixture of two or more solvents.

[Electrophotographic apparatus, electrophotographic method]
The electrophotographic apparatus according to the present invention includes the above-described electrophotographic photosensitive member, a charging unit that charges the surface of the electrophotographic photosensitive member, an image exposing unit that forms an electrostatic latent image on the surface of the electrophotographic photosensitive member, A developing unit that develops an electrostatic latent image to form a toner image; and a transfer unit that transfers the toner image to a recording material. The image forming apparatus further includes other units that are appropriately selected as necessary. Do it. Examples of other means include cleaning means, static elimination means, recycling means, and control means.

<First Embodiment>
Next, the electrophotographic apparatus and the electrophotographic method according to the present invention will be described in detail using specific examples with reference to the drawings.
FIG. 3 is a schematic diagram for explaining the electrophotographic apparatus and the electrophotographic method of the present invention, and is a schematic diagram showing the configuration of the electrophotographic apparatus according to the first embodiment of the present invention.
In FIG. 3, a photoreceptor 1 is the above-described electrophotographic photoreceptor according to the present invention. The photosensitive member 1 has a drum shape, but may be a sheet shape or an endless belt shape.
In the embodiment shown in FIG. 3, the drum-shaped photoconductor 1 is rotated counterclockwise in the drawing by a driving means (not shown), and an image is formed by an electrophotographic method by each means provided around the photoconductor 1. The Hereinafter, description will be given in the order of each step of the electrophotographic method.

(Charging means, charging process)
First, the surface of the photoreceptor 1 is uniformly charged by a charging charger 3 as a charging unit. The charging charger 3 may be appropriately selected from conventionally known ones according to the characteristics of the photosensitive member 1 and the developing toner. The surface of the photosensitive member 1 is set to a predetermined potential with a predetermined polarity (positive charging or negative charging). Any one that can be charged is applicable. Examples of the charging charger 3 include a corotron, a scorotron, a solid state charger (solid state charger), a charging roller, and the like.

(Image exposure means, image exposure process)
Next, an electrostatic latent image is formed on the surface of the uniformly charged photoreceptor 1 by an image exposure unit 5 as an image exposure unit. As the image exposure unit 5, for example, fluorescent materials such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and electroluminescence (EL) can be used. It is preferable to use a light emitting diode or a semiconductor laser. In order to irradiate only light in a desired wavelength range during image exposure, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter are used. It can be disposed between the photoreceptor 1 and the image exposure unit 5.

(Development means, development process)
The electrostatic latent image formed on the surface of the photoreceptor 1 is developed by a developing unit 6 as developing means using toner. That is, the electrostatic latent image is developed by the developing unit 6 to form a visible toner image. The developing unit 6 may be appropriately selected from conventionally known developing units according to the toner to be used. Examples of the developing unit 6 include a one-component developing method and a two-component developing method, and further, there are ones for magnetic toner and non-magnetic toner, respectively.

(Transfer means, transfer process)
Further, the toner image carried on the photoreceptor 1 is conveyed to a transfer charger 10 as a transfer unit as the photoreceptor 1 rotates. As the transfer charger 10, the same one as the above-described charging charger 3 can be applied, but a combination of the transfer charger 10 and the separation charger 11 is effective as shown in FIG. 3. Further, in order to improve the transfer efficiency, it is preferable to provide a pre-transfer charger 7 upstream of the transfer charger 10 (relative to the rotation direction of the photosensitive member 1) and precharge the toner image. As the transfer charger 7, the same one as the above-described charging charger 3 can be applied.
On the other hand, at a position where the photoreceptor 1 and the transfer charger 10 face each other, a transfer paper 9 as a recording material is conveyed by a registration roller 8 or the like so that a toner image is transferred to a desired position on the transfer paper 9. The
The toner image is transferred to the transfer paper 9 by the transfer charger 10 at a position where the toner image on the photoreceptor 1 and the transfer paper 9 face each other.

  The transfer paper 9 onto which the toner image has been transferred reaches the separation claw 12 by rotating with the photosensitive member 1 and is separated from the surface of the photosensitive member 1 by the separation claw 12, and further description is omitted. Then, it is discharged outside the electrophotographic apparatus through a fixing process.

(Cleaning means, cleaning process)
Here, on the surface of the photosensitive member 1 after transfer by the transfer charger 10 and separation of the transfer paper 9 by the separation claw 12, toner images that could not be transferred onto the transfer paper 9, so-called transfer residual toner, paper dust, etc. There are deposits. For this reason, deposits are removed from the surface of the photoreceptor 1 by the fur brush 14 and the cleaning blade 15 which are cleaning means. As the cleaning means, in addition to the fur brush 14 and the cleaning blade 15, conventionally known ones such as a mag fur brush can be used. Further, only the fur brush or only the cleaning blade can be used. In order to improve the cleaning efficiency, it is preferable to precharge by the pre-cleaning charger 13 before using the cleaning means. As the pre-cleaning charger 13, the same one as the above-described charging charger 3 can be applied.

(Static elimination means, static elimination process)
The photosensitive member 1 from which the deposits have been removed from the surface by the cleaning means is further discharged by irradiating light from the charge removing lamp 2 as a charge removing means, thereby completing a series of image forming processes by the electrophotographic method. By repeating this series of electrophotographic image forming processes, it is possible to form images on a plurality of recording materials.
Conventionally known means can be used as the charge eliminating means. For example, the charge removing lamp 2 can be the same as the image exposure unit 5 described above.

  In the image forming process by the series of electrophotographic methods described above, a positive (negative) electrostatic latent image is formed on the surface of the photoreceptor 1 when the electrophotographic photoreceptor 1 is positively (negatively) charged and image exposure is performed. Is formed. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. The charging polarity of the electrophotographic photoreceptor 1 and the polarity of the toner used for development are arbitrary, and any may be used.

  Further, the various light sources used in the image exposure unit 5 are not limited to being used in the form shown in FIG. 3, and other than that, a transfer process, a static elimination process, a cleaning process, or a previous process using light irradiation together. It can be used for processes such as exposure.

<Second Embodiment>
FIG. 4 is a schematic diagram showing the configuration of the electrophotographic apparatus according to the second embodiment of the present invention.
The photosensitive member 21 has at least photosensitive layers 34 and 34a, and is driven by driving rollers 22a and 22b. The photosensitive member 21 is charged by a charger 23 as charging means, and is exposed and developed by a light source 24 as image exposure means. Development (not shown), transfer using a transfer charger 25 serving as a transfer unit, exposure before cleaning using a light source 26, cleaning using a cleaning brush 27 serving as a cleaning unit, and static elimination using a light source 28 serving as a charge eliminating unit are repeated. In FIG. 4, the photosensitive member 21 (of course, the support is translucent in this case) is irradiated with light before cleaning from the conductive support 30 side.

  The image forming process by the electrophotographic method performed using the electrophotographic apparatus shown in FIG. 4 exemplifies the embodiment in the present invention, and it goes without saying that other embodiments are possible. For example, in FIG. 4, the pre-cleaning exposure is performed from the conductive support 30 side, but this may be performed from the photosensitive layers 34 and 34a side. You may carry out from 30 side.

  On the other hand, as the process of irradiating light, image exposure, pre-cleaning exposure, and static elimination exposure are illustrated, but in addition, there are provided pre-transfer exposure, pre-exposure of image exposure, and other known light irradiation processes. Thus, the photosensitive member 21 can be irradiated with light.

<Third Embodiment>
Furthermore, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as a full-color electrophotographic apparatus to which the present invention is applied.
FIG. 5 is a schematic view showing the configuration of the electrophotographic apparatus according to the third embodiment of the present invention. In FIG. 5, a drum-shaped photoconductor 56 which is a latent image carrier is uniformly charged by a charging charger 53 which is a charging means using a corotron or a scorotron while the surface thereof is rotated counterclockwise in the figure. After that, the electrostatic latent image is carried by receiving scanning of laser light L emitted from a laser optical device which is an image exposure means (not shown). Since this scanning is performed based on single-color image information obtained by decomposing a full-color image into yellow, magenta, cyan, and black color information, a single-color electrostatic image of yellow, magenta, cyan, or black is formed on the photosensitive drum 56. A latent image is formed. A revolver developing unit 50 is disposed on the left side of the photosensitive drum 56 in the drawing. This has a yellow developing unit, a magenta developing unit, a cyan developing unit, and a black developing unit as developing means in a rotating drum-shaped casing, and each developing unit is opposed to the photosensitive drum 56 by rotation. Move sequentially to development position. The yellow developer, magenta developer, cyan developer, and black developer are for developing an electrostatic latent image by attaching yellow toner, magenta toner, cyan toner, and black toner, respectively. An electrostatic latent image for yellow, magenta, cyan, and black is sequentially formed on the photosensitive drum 56, and these images are sequentially developed by the developing units of the revolver developing unit 50, so that a yellow toner image, a magenta toner image, and a cyan toner are developed. A toner image and a black toner image are obtained.

  An intermediate transfer unit is disposed on the downstream side of the photosensitive drum 56 from the development position. This is because the intermediate transfer belt 58 stretched by a tension roller 59a, an intermediate transfer bias roller 57 as a transfer means, a secondary transfer backup roller 59b, and a belt drive roller 59c is driven by rotation of the belt drive roller 59c. Move endlessly clockwise. The yellow toner image, magenta toner image, cyan toner image, and black toner image developed on the photosensitive drum 56 enter an intermediate transfer nip where the photosensitive drum 56 and the intermediate transfer belt 58 are in contact with each other. Then, while being influenced by the bias from the intermediate transfer bias roller 57, it is superimposed on the intermediate transfer belt 58 and intermediately transferred (primary transfer) to form a four-color superimposed toner image.

  The surface of the photosensitive drum 56 that has passed through the intermediate transfer nip with rotation is cleaned of residual toner by a drum cleaning unit 55 that is a cleaning unit. The drum cleaning unit 55 cleans the transfer residual toner by a cleaning roller to which a cleaning bias is applied, but a cleaning brush made of a fur brush, a mag fur brush, or a cleaning blade may be used. .

  The surface of the photosensitive drum 56 from which the transfer residual toner has been cleaned is neutralized by a neutralizing lamp 54 serving as a neutralizing unit. As the charge removal lamp 54, a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), an electroluminescence (EL), or the like is used. A semiconductor laser is used as the light source of the laser optical device. About these emitted lights, you may make it use only a desired wavelength range by various filters, such as a sharp cut filter, a band pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter.

  On the other hand, the registration roller pair 61 that sandwiches the transfer paper 60 that is a recording material fed from a paper feed cassette (not shown) between the two rollers has a four-color superimposed toner image on the intermediate transfer belt 58. Are fed toward the secondary transfer nip where the intermediate transfer belt 58 and the transfer belt 62 are in contact with each other. The four-color superimposed toner images on the intermediate transfer belt 58 are collectively transferred onto the transfer paper 60 under the influence of the secondary transfer bias from the paper transfer bias roller 63 as the secondary transfer means in the secondary transfer nip. Secondary transferred. A full color image is formed on the transfer paper 60 by this secondary transfer. The transfer paper 60 on which the full-color image is formed is sent to the transport belt 64 by the transfer belt 62. The conveyor belt 64 feeds the transfer paper 60 received from the transfer unit into the fixing unit 65. The fixing unit 65 conveys the transferred transfer paper 60 while being sandwiched between fixing nips formed by contact between the heating roller and the backup roller. The full-color image on the transfer paper 60 is fixed on the transfer paper 60 under the influence of heating from the heating roller and pressure applied in the fixing nip.

  Although not shown, a bias for adsorbing the transfer paper 60 is applied to the transfer belt 62 and the conveyance belt 64. In addition, a paper neutralization charger that neutralizes the transfer paper 60 and three belt neutralization chargers that neutralize each belt (intermediate transfer belt 58, transfer belt 62, and conveyance belt 64) are provided. The intermediate transfer unit also includes a belt cleaning unit having the same configuration as that of the drum cleaning unit 55, thereby cleaning the transfer residual toner on the intermediate transfer belt 58.

FIG. 6 is a schematic diagram showing the configuration of the electrophotographic apparatus according to the fourth embodiment of the present invention. This embodiment is a tandem type electrophotographic apparatus having an intermediate transfer belt 87, and does not share the photosensitive drum 80 for each color, but includes photosensitive drums 80Y, 80M, 80C, and 80Bk for each color. Yes. Further, a developing unit (developing unit) 82, a drum cleaning unit (cleaning unit) 85, a static elimination lamp (static elimination unit) 83, a charging roller (charging unit) 84 for uniformly charging the drum, and a bias roller (secondary transfer unit) 86. Also has one for each color. In the printer shown in FIG. 6, the charging charger 53 is provided as the drum uniform charging means, but in this apparatus, the charging roller 84 is provided. A fur brush 94 is provided as a belt cleaning unit for cleaning the intermediate transfer belt 87.
In addition, a registration roller pair 88, a paper 89 as a recording material, a paper transfer bias roller 90 as a secondary transfer means, a transfer belt 91, a transport belt 92, and a fixing unit 93 are disposed. Since it overlaps with the embodiment, the description is omitted.

  In the tandem method, latent image formation (image exposure process) and development of each color can be performed in parallel, so that the image formation speed can be much faster than the revolver method.

[Process cartridge]
The image forming apparatus as described above may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge. The process cartridge is a single device (part) that contains the photosensitive member 21 and includes at least one means selected from charging means, image exposure means, developing means, transfer means, cleaning means, and static elimination means. is there.

The process cartridge has various shapes and the like, and a general example is shown in FIG.
FIG. 7 is a schematic diagram showing the configuration of an embodiment of a process cartridge according to the present invention.
In the present embodiment, an electrophotographic photosensitive member 16, a charging charger 17 as a charging unit, an image exposing unit 19 as an image exposing unit, a developing roller 20 as a developing unit, and a cleaning brush 18 as a cleaning unit. It comprises.

Of Examples 1 to 12 shown below, Examples 5 to 7 are test examples as reference examples not belonging to the scope of the present invention.
Example 1
An alkyd resin (Beckolite M-6401-50; manufactured by Dainippon Ink & Chemicals, Inc.) and an amino resin (Super Becamine G-821-60) are formed on a cylindrical drum (conductive support) made of uncut aluminum having a diameter of 24 mm. Manufactured by Dainippon Ink & Chemicals, Inc.) at a weight ratio of 65:35 to produce a mixed resin, and the mixed resin and titanium oxide (CR-EL; manufactured by Ishihara Sangyo Co., Ltd.) at a ratio of 1: 3. And an undercoat layer having a thickness of 1.5 μm was formed as a coating solution by dissolving in methyl ethyl ketone.

  Next, 15 g of oxytitanium phthalocyanine powder having a maximum peak at an X-ray diffraction angle Cukα (2θ ± 0.2 degrees) of 27.3 degrees in FIG. 8 was added to glass beads and 500 ml of 1,3 dioxolane with polyvinyl butyral resin (BX- (1; manufactured by Sekisui Chemical Co., Ltd.) A solution in which 10 g was dissolved was added and dispersed with a sand mill disperser for 20 hours. The resulting dispersion was filtered to remove the glass beads, thereby preparing a coating solution for a charge generation layer. This was dip-coated on the undercoat layer and dried to form a charge generation layer having a thickness of 0.2 μm.

  Next, a polycarbonate resin (PCZ-500; manufactured by Mitsubishi Gas Chemical Co., Inc.) as a binder resin, a charge transfer agent represented by the chemical formula (Ia), an amine compound represented by the chemical formula (IIa), and an ultraviolet absorber described below. A compound represented by the chemical formula (A) was prepared at a weight ratio of 1: 1: 0.1: 0.1 and dissolved in tetrahydrofuran to prepare a charge transfer layer coating solution. The substrate on which the charge generation layer was formed was dip-coated in the charge transfer layer coating solution and dried at 130 ° C. for 60 minutes to form a charge transfer layer having a thickness of 25.0 μm, thereby producing an electrophotographic photosensitive member.

(Example 2)
The weight ratio of the binder resin used in Example 1, the charge transfer agent represented by the chemical formula (Ia), the amine compound represented by the chemical formula (IIa), and the compound represented by the chemical formula (A) was 1: 1: An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the ratio was 0.01: 0.1.

(Example 3)
The weight ratio of the binder resin used in Example 1, the charge transfer agent represented by the chemical formula (Ia), the amine compound represented by the chemical formula (IIa), and the compound represented by the chemical formula (A) was 1: 1: An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the ratio was 0.3: 0.1.

Example 4
An electrophotographic photoreceptor is produced in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (Id) is used instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1. did.

(Example 5)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (Ie) was used instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1. did.

(Example 6)
An electrophotographic photoreceptor is produced in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (If) is used instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1. did.

(Example 7)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transfer agent represented by the chemical formula (Ig) was used instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1. did.

(Example 8)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amine compound represented by the chemical formula (IIb) was used instead of the amine compound represented by the chemical formula (IIa) used in Example 1.

Example 9
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the amine compound represented by the chemical formula (IIc) was used instead of the amine compound represented by the chemical formula (IIa) used in Example 1.

(Example 10)
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the amine compound represented by the chemical formula (IId) was used instead of the amine compound represented by the chemical formula (IIa) used in Example 1.

(Example 11)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the amine compound represented by the chemical formula (IIe) was used instead of the amine compound represented by the chemical formula (IIa) used in Example 1.

(Example 12)
In Example 1, an antioxidant represented by the following chemical formula (B) was added, a binder resin, a charge transfer agent represented by the chemical formula (Ia), an amine compound represented by the chemical formula (IIa), and the chemical formula (A) An electrophotographic photosensitive member was produced in the same manner as in Example 1 with the weight ratio of the ultraviolet absorber shown and the antioxidant shown by the following chemical formula (B) being 1: 1: 0.1: 0.1: 0.1. did.

(Comparative Example 1)
Instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1, a charge transfer agent represented by the following chemical formula (C) was used, and the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that. Produced.

(Comparative Example 2)
Instead of the charge transfer agent represented by the chemical formula (Ia) used in Example 1, a charge transfer agent represented by the following chemical formula (D) was used, and the electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that. Produced.

(Comparative Example 3)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the charge transfer layer of Example 1 did not contain the amine compound represented by the chemical formula (IIa).

(Comparative Example 4)
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the antioxidant represented by the chemical formula (B) was used instead of the amine compound represented by the chemical formula (IIa) used in Example 1. did.

(Comparative Example 5)
In the charge transfer layer coating liquid of Example 1, the amine compound represented by the chemical formula (IIa) is replaced with an antioxidant represented by the following chemical formula (E), and an ultraviolet absorber represented by the chemical formula (A) is used. Except for the weight ratio of the binder resin, the charge transfer agent represented by the chemical formula (Ia), and the antioxidant represented by the following chemical formula (E), 1: 1: 0.1. An electrophotographic photosensitive member was produced.

(Comparative Example 6)
In the charge transfer layer coating liquid of Example 1, the amine compound represented by the chemical formula (IIa) was replaced with an antioxidant represented by the following chemical formula (F), except for the ultraviolet absorber formula (A), and a binder. The weight ratio of the resin, the charge transfer agent represented by the chemical formula (Ia), and the antioxidant represented by the following chemical formula (F) was 1: 1: 0.1. The body was made.

(Comparative Example 7)
In the charge transfer layer coating liquid of Example 1, the amine compound represented by the chemical formula (IIa) is replaced with an antioxidant represented by the following chemical formula (G), except for the ultraviolet absorber formula (A). The weight ratio of the resin, the charge transfer agent represented by the chemical formula (Ia), and the antioxidant represented by the following chemical formula (G) was 1: 1: 0.1. The body was made.

(Photoreceptor evaluation)
<Evaluation of electrical characteristics with a simple measuring instrument>
The electrophotographic photosensitive members produced in Examples 1 to 12 and Comparative Examples 1 to 7 were subjected to evaluation of electrophotographic characteristics under the following conditions using a photosensitive drum evaluation device (dynamic mode measurement).

Using an electrophotographic photosensitive member evaluation apparatus (manufactured by Yamanashi Denshi Kogyo Co., Ltd.), the electrophotographic photosensitive member produced in the examples and comparative examples is subjected to the surface potential of the photosensitive member by the scorotron method in an environment of a temperature of 23 ° C. and a humidity of 50%. When the discharge current is adjusted so that the voltage becomes about −700 V, the charging potential at that time is set to (V0), the electrophotographic photosensitive member is charged, and irradiated with a semiconductor laser having a wavelength of 650 nm, the exposure is 0.13 to 0.15 μJ. The surface potential adjusted so that the surface potential of the photoconductor is about ½ (about −350 V) with the amount of energy was defined as (VH). The surface potential when exposed with an exposure energy amount of 0.6 μJ / cm ² was defined as a photoreceptor residual potential (VL).

  The electrophotographic photosensitive member was exposed to an ozone concentration of 5 ppm and an exposure time of 5 days using an ozone exposure test apparatus (manufactured by Directec). The surface potential (VO), sensitivity potential (VH), and residual potential (VL) of the photoconductor before and after exposure were measured. For neutralization, an LED (20 μW) having a wavelength of 660 nm was used. The drum rotation speed of the electrophotographic photosensitive member was 150 rpm, and the time from when the laser beam was irradiated until the potential was measured (movement time from the exposure position to the measurement position) was 0.06 seconds. The results are shown in Table 1 below.

Similarly, the electrophotographic photosensitive member was exposed for 4 days at a NO concentration of 40 ppm and a NO ₂ concentration of 10 ppm with a NOx exposure test apparatus (manufactured by Directec). The surface potential (VO), sensitivity potential (VH), and residual potential (VL) of the photoconductor before and after exposure were measured. For neutralization, an LED (20 μW) having a wavelength of 660 nm was used. The drum rotation speed of the electrophotographic photosensitive member was 150 rpm, and the time from when the laser beam was irradiated until the potential was measured (movement time from the exposure position to the measurement position) was 0.06 seconds. The results are shown in Table 1 below.

  In Table 1, the values of the surface potentials V0 and VH are superior to the initial set values V0 of 700 (-V) and VH350 (-V) as the amount of potential change after light irradiation is smaller.

<Evaluation of actual image (halftone evaluation)>
The electrophotographic photoconductors produced in Examples 1 to 12 and Comparative Examples 1 to 7 were subjected to an initial photoconductor and a photoconductor subjected to an ozone exposure test or an NOx exposure test in a color printer (manufactured by Ricoh: SP C220). Equipped with a half-tone image (2by2) output at room temperature of 23 ° C and humidity of 50%. Image density difference between initial and exposure (measured with Macbeth densitometer) ΔID (ΔID = initial ID-after exposure test) Table 2 shows the results of comparison of (ID).
Note that 2by2 means a print pattern for forming dots of 2 × 2 pixels out of 4 × 4 pixels as shown in FIG.

  Examples 1 to 12 are electrophotographic photosensitive members containing a charge transfer agent represented by the general formula (I) and an amine compound represented by the general formula (II), and are excellent in ozone resistance and NOx resistance. The charging potential, sensitivity potential, residual potential, and image density were favorable. Example 2 is a case where the addition amount of the amine compound represented by the general formula (II) is small. However, although the surface potential and sensitivity potential are slightly inferior to Example 1, the density difference on the image is small and there is no practical problem. It was a level. Further, Example 3 is a case where the amount of the amine compound represented by the general formula (II) is large, but VL is somewhat high, but the image density is the same level as Example 1, and practical use. The top level was fine.

  In Comparative Example 3, an electrophotographic photosensitive member was prepared without adding the amine compound represented by the general formula (II) to the photosensitive layer, but V0 and VH after exposure to ozone and NOx were significantly reduced. The image density change ΔID also has a significantly large value. In Comparative Examples 4 to 7, different compounds were added to the photosensitive layer to prepare an electrophotographic photosensitive member. The decrease in V0 and VH after exposure to ozone and NOx was small, but the change in image density was Although the degree of change was small compared to Comparative Example 1, it was not a practical level, and was inferior to Examples 1-12. Further, in Comparative Examples 1 and 2 using a low molecular weight charge transfer agent, VH and VL were remarkably high, and the image evaluation by the color printer did not give any density and was not the object of comparison.

As can be seen from the above description, the electrophotographic photosensitive member of the present invention is excellent in ozone resistance and NOx resistance, and is excellent in electrical characteristics such as charging, sensitivity and residual potential.
In addition, by using these electrophotographic photosensitive members, it is not necessary to replace the electrophotographic photosensitive member, and high-speed printing is realized or the apparatus is downsized along with the reduction in the diameter of the electrophotographic photosensitive member. In addition, an electrophotographic method, an electrophotographic apparatus, and an electrophotographic process cartridge capable of stably obtaining a high-quality image can be provided.

DESCRIPTION OF SYMBOLS 30 Conductive support 31 Undercoat layer 32 Charge generation layer 33 Charge transfer layer 34 Photosensitive layer 34a Single layer type photosensitive layer

Japanese Unexamined Patent Publication No. 01-230055 Japanese Patent Laid-Open No. 03-172852 JP 2002-333731 A Japanese Patent Laid-Open No. 04-56866

Claims (8)

A conductive support;
A photosensitive layer provided on the conductive support,
The photosensitive layer contains a charge generating agent, a charge transfer agent represented by the following general formula (I), and an amine compound represented by the following general formula (II). body.
[In the above formula (I), R _{1 to} R ₃ each independently represent hydrogen, a halogen atom, or an optionally substituted alkyl group having 1 to 6 carbon atoms, and n = 1 . ]
[In the above formula (II), A and B are each independently a group represented by the following formula (i) or the following formula (ii), and may be the same or different.
—CH ₂ X Formula (i)
—CH ₂ CH ₂ Y Formula (ii)
However, X and Y each independently represent an aromatic residue, and these may have a substituent. ] A charging step for charging the surface of the electrophotographic photosensitive member according to claim 1;
An image exposure step of forming an electrostatic latent image on the electrophotographic photoreceptor;
A developing step of developing the electrostatic latent image to form a toner image;
An electrophotographic method comprising repeatedly performing a transfer step of transferring the toner image directly to a recording material or to a recording material via an intermediate transfer member. A charging step for charging the surface of the electrophotographic photosensitive member according to claim 1;
An image exposure step of forming an electrostatic latent image on the electrophotographic photoreceptor;
A developing step of developing the electrostatic latent image to form a toner image;
A transfer step of transferring the toner image directly to the recording material or to the recording material via an intermediate transfer member, and repeatedly.
In the image exposure step, the electrostatic latent image is formed by an LD or an LED. An electrophotographic photoreceptor according to claim 1;
Charging means for charging the surface of the electrophotographic photosensitive member;
Image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image to form a toner image;
An electrophotographic apparatus comprising: transfer means for transferring the toner image directly to a recording material or transferring the toner image to a recording material via an intermediate transfer member. An electrophotographic photoreceptor according to claim 1;
Charging means for charging the surface of the electrophotographic photosensitive member;
Image exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image to form a toner image;
Transfer means for directly transferring the toner image to a recording material or transferring the toner image to the recording material via an intermediate transfer member,
The digital electrophotographic apparatus, wherein the image exposure means is an LD or an LED.   6. The electrophotographic apparatus according to claim 4, wherein the electrophotographic photosensitive member is a tandem type having a plurality of each of the electrophotographic photosensitive member, the charging unit, the developing unit, and the transfer unit. An intermediate transfer member; and an intermediate transfer means;
The transfer means primarily transfers the toner image formed on the electrophotographic photosensitive member to the intermediate transfer member to form an image on the intermediate transfer member,
The intermediate transfer means secondarily transfers the image on the intermediate transfer member onto the recording material,
When the image on the intermediate transfer member is a color image composed of a plurality of colors of toner,
The transfer means forms an image on the intermediate transfer member by sequentially superimposing colors on the intermediate transfer member,
The electrophotographic apparatus according to claim 4, wherein the intermediate transfer unit performs secondary transfer of the intermediate transfer image onto the recording material in a lump. An electrophotographic photoreceptor according to claim 1;
Charging means for charging the surface of the electrophotographic photosensitive member; image exposing means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member; developing means for developing the electrostatic latent image to form a toner image; And at least one selected from a cleaning unit that cleans the surface of the photosensitive member and a transfer unit that directly transfers the toner image to the recording material or transfers the toner image to the recording material via an intermediate transfer member. Process cartridge for electrophotographic equipment.