JPH09325504A - Electrophotographic photoreceptor, process cartridge having the electrophotographic photoreceptor and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain stable potential characteristics and good images under the entire environment from a low temp. and low humidity to high temp. and high humidity even if the photosensitive layer of an electrophotographic photoreceptor is made thin by specifying the film thickness of a photosensitive layer to a specific value or below and forming an aluminum base having an anodically oxidized film. SOLUTION: The film thickness of the photosensitive layer of the electrophotographic photoreceptor 1 is specified to <12μm. As a result, the high-quality images which are more sharpened in the potential distribution of the electrostatic latent image on the surface of the electrophotographic photoreceptor 1 and faithfully reproduced in the dots of digital light are obtd. The anodically oxidized film is formed on the surface of the aluminum base. As a result, the charge implantation from the substrate is prohibited even under a high electric field by the thin film and the high-grade and high-stability images having the excellent environment stability and durable stability are obtd. The process cartridge integrally supports the means selected from a group consisting of the electrophotographic photoreceptor 1, an electrostatic charging means 3, a developing means 3 and a cleaning means 9 and is freely attachable and detachable to and from the electrophotographic device body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors are required to have high charge retention ability, potential stability during repeated use, environmental stability, high sensitivity and high quality image quality. Recently, the environment surrounding a computer is changing drastically due to the effects of high-speed CPU, low-cost memory, and OS maintenance. Among them, printers as I / O are required to have higher definition and higher image quality. Currently, image conversion,
Digital recording technology that is easy to edit has become the mainstream. As for the resolution of electrophotography, it is required to reproduce a dot density of 1200 dpi or more for digital light from a laser, an LED array, a liquid crystal shutter, or the like.

As a photoconductor for electrophotography, high definition,
As a means for achieving high image quality, a high γ value photoconductor has been reported (for example, JP-A-1-172863). The high γ-value photoconductor is characterized in that the potential decay behavior of image exposure has a slow induction period in the low light amount range, and shows a sharp potential decay in the middle and high light amount regions. The potential distribution of the dot-shaped electrostatic latent image is sharp, the developer distribution on the surface of the photoreceptor after development and the image density after transfer are also sharp, and the scattering of the developer is small and the resolution is high.
High-quality images can be obtained.

On the other hand, as a means for sharpening the potential distribution of the electrostatic latent image, a method of reducing the film thickness of the electrophotographic photoconductor can be considered. For example, in the case of a laminated photoreceptor, the charges generated in the charge generation layer are injected into the charge transport layer and move to the surface along the electric field to neutralize the surface potential of the photoreceptor to form an electrostatic latent image. By reducing the film thickness of the charge transport layer, the electric field strength is increased and the diffusion length is decreased to suppress the diffusion of charges in the direction perpendicular to the electric field, and a sharp static image faithful to digital light such as laser light is obtained. It becomes possible to form a latent image. Also, considering the photoconductor as a kind of dielectric, the capacitance of the photoconductor increases by decreasing the film thickness,
Therefore, the charge density on the surface of the photoconductor is increased to obtain a predetermined surface potential, and as a result, the developing electric field is increased, the potential of the electrostatic latent image becomes deeper in the potential direction, and high resolution is realized.

However, in conventional photoconductors, when the film becomes thin, the electric field strength increases, so that charge injection from the support side is promoted, and a phenomenon such as so-called fog in the reversal developing system appears, which lowers the charging ability. Further, there has been a problem that the potential fluctuation during durable use becomes large, and in particular, the bright potential (VL) rises non-recovery with durability. Although the cause has not been sufficiently clarified, it is considered that a large electric current flows inside the photoconductor due to an increase in electric field strength, which causes irreversible deterioration of the photoconductor material along with durability. Therefore, when the film thickness of the photoconductor is reduced, dot reproducibility of digital light such as a laser is improved and the resolution is increased, but there is a problem in practical use because there is a problem due to charge injection.

The electrophotographic photosensitive member basically comprises a support and a photosensitive layer formed on the support. Aluminum and aluminum alloys are often used as the support, but on the surface of aluminum and aluminum alloys,
Since there are structural defects such as protrusions and foreign substances, oil such as rust preventive oil, and chemical impurities, the photosensitive layer cannot be provided on the support as it is. Therefore, after forming a uniform surface by a method such as cutting and polishing, oil and impurities are removed by washing with water or an organic solvent and used as a support. However, it is not preferable to use as it is because of the existence of minute structural defects and chemical impurities because the electrophotographic characteristics are unstable.

Therefore, the structural defects of the support are covered, the adhesion between the photosensitive layer and the support is improved, the photosensitive layer is protected from electrical damage, the charging property is improved, and the charge injection property from the substrate to the photosensitive layer is improved. Therefore, it is effective to provide an intermediate layer between the photosensitive layer and the support. Conventionally, as the intermediate layer, there have been proposed (a) a thin film of a resin alone, (b) a thin film of a resin containing a conductive filler, and the like. In the case of the thin film of (a), since the conductive filler is not contained, the resistance of the film is high,
Moreover, a thick film must be used to cover the defects on the support. Therefore, it has a drawback that the residual potential becomes high in the initial and repeated use. In order to put the thin film of (a) into practical use, the defects on the support should be reduced and the thickness of the intermediate layer should be very small. Need to be thin. Further, the thin film of (b) has an advantage that suitable conductivity can be imparted by dispersing the conductive filler, but when the conductive filler has poor dispersibility, the resistance and the dielectric constant of the intermediate layer are reduced. The electrical characteristics change, and the potential characteristics and image quality are greatly affected. Further, if the dispersibility of the filler is poor, the surface smoothness of the film will be poor, and this will cause coating defects. As the conductive filler of (b) above, a metal (Japanese Patent Laid-Open No. 58-181054) is used.
JP-A-58-181054) and metal oxides (JP-A-58-181054).

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member excellent in environmental stability and durability stability, and a process cartridge and an electron using the electrophotographic photosensitive member. It is to provide a photographic device.

[0009]

The present invention provides an electrophotographic photoreceptor having a photosensitive layer on an aluminum support, wherein the thickness of the photosensitive layer is less than 12 μm, and the aluminum support has an anodized film. And an electrophotographic photosensitive member.

The electrophotographic photoreceptor of the present invention comprises an aluminum support and a photosensitive layer formed on the support. As a means for sharpening an electrostatic latent image, the photosensitive layer is thinned, In addition, the aluminum support has an anodized film on its surface.

In the electrophotographic photoreceptor of the present invention, the potential distribution of the electrostatic latent image on the surface of the photoreceptor is further improved by making the thickness of the photosensitive layer thin, specifically, the thickness of the photosensitive layer less than 12 μm. A sharp, high-quality image that faithfully reproduces the dots of digital light can be obtained. Further, by forming an anodic oxide film on the surface of the aluminum support, charge injection from the substrate is prevented even under a high electric field due to the thin film, and for example, so-called fog in a reversal development system or bright potential (V during repeated use due to durability). / L) is suppressed, and a high-quality and highly stable image excellent in environmental stability and durability stability can be obtained.

Conventionally, a corona discharge device has been generally used as a charging means for an electrophotographic photoreceptor, but it has a high ozone generation amount which is harmful to the human body due to environmental problems.
Ozone, and adhered to the charging products photosensitive layer such as NO _X, adversely affecting the chargeability of the reduction and durability characteristics, charging characteristics can prone unstable image unevenness, for use over a long period of time On the other hand, there is a problem such as the problem of wire contamination, and in order to solve these problems, a charging member is provided on the photosensitive layer of the electrophotographic photoconductor, which has a low voltage and generates a small amount of ozone. A contact charging device that contacts and charges is developed. However, since the charging member is in direct contact with the photosensitive layer, if there are local defects in the photosensitive layer and the support, such as foreign substances such as dust, chemical substances such as oil, structural defects of the support, etc. Image defects such as black spots and fog.

Generally, an aluminum anodic oxide film is composed of a dense barrier layer and a porous porous layer, and the formation of the anodic oxide film provides excellent structural uniformity such as chemical and unevenness on the surface. . The barrier layer has a function of inhibiting hole injection from the substrate and needs to have a certain thickness, but if it is too thick, it causes an increase in residual potential and deterioration of sensitivity. Further, the porous layer enhances the adhesive force with the photosensitive layer, but if it is too thick, it causes an increase in residual potential and deterioration of sensitivity as in the case of the barrier layer.

The anodic oxide film used in the electrophotographic photoreceptor of the present invention has a barrier layer thickness of 50 to 1000 angstroms, preferably 100 to 500 angstroms.
The thickness of the porous layer is 1 to 15 μm, preferably 3 to 10 μm
It is.

The anodic oxide film used in the electrophotographic photoreceptor of the present invention uses an inorganic acid such as sulfuric acid, chromic acid, boric acid or the like, or an organic acid such as oxalic acid, sulfonic acid or the like as an electrolytic solution, and the applied voltage, current density, Conditions such as treatment temperature and time can be selected according to the type and film thickness of the above-mentioned electrolytic solution.

The anodic oxide film used in the electrophotographic photosensitive member of the present invention may be subjected to etching treatment with an alkali, acid or the like or degreasing using a surfactant, an organic solvent or the like as a pretreatment for the anodic oxidation.

The anodic oxide film used in the electrophotographic photoreceptor of the present invention may be subjected to electrolytic treatment and then subjected to sealing treatment. As a method of sealing treatment, hot water treatment, steam treatment, various sealing agents such as nickel acetate and nickel fluoride may be used, but treatment with nickel acetate capable of efficiently sealing fine pores is performed. Is preferred.

The photosensitive layer of the electrophotographic photosensitive member of the present invention may be a single layer or a laminated structure composed of a charge generation layer and a charge transport layer. When the photosensitive layer is a single layer, the charge generating substance and the charge transporting substance are contained in the same layer, and the photocarrier is generated and moved in the same layer. When the photosensitive layer has a laminated structure, the order of laminating the charge generating layer containing the charge generating substance and the charge transporting layer containing the charge transporting substance may be from the support side to the charge generating layer and the charge transporting layer, or vice versa. But it's okay.

Examples of the charge generating substance include azo pigments (eg, monoazo, bisazo, trisazo, etc.), metal and metal-free phthalocyanine pigments, indigo pigments (eg, indigo, thioindigo), quinone pigments (eg, anthanthrone). , Pyrenequinone, etc.), perylene pigments (eg, perylene anhydride, perylene imide, etc.),
Examples include squalium-based dyes, pyrylium, thiopyrylium salts, triphenylmethane-based dyes, and the like. Also,
Inorganic materials such as selenium, selenium-tellurium or amorphous silicon can also be used as the charge generating substance.

The charge transport material includes an electron transport material and a hole transport material. Examples of the electron transport material include 2,
4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil, tetracyanoquinodimethane and the like can be mentioned. Examples of the hole transport material include polycyclic aromatic compounds (eg, pyrene, anthracene, etc.), heterocyclic compounds (eg, carbazole, indole-type compounds).
, Imidazole, oxazole, thiazole, oxadiazol, pyrazol, pyrazoline, thiadiazole
, Triazol, etc.), hydrazone compounds (eg p
-Diethylaminobenzaldehyde-N, N-diphenylhydrazone, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazol, etc.), styryl compounds (for example, α-phenyl-4'-N, N-diaminostilbene, 5- [4- (di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] dicycloheptene, etc.), benzidine compounds, triarylamine compounds and the like.

In the single photosensitive layer, the charge generating substance and the charge transporting substance are contained in an amount of 10 to 70% by weight, further 20 to 7% by weight.
It is preferable to contain 0% by weight.

When the photosensitive layer has a laminated structure, the film thickness of the charge generation layer is preferably 0.001 to 5 μm, more preferably 0.05 to 2 μm, and the film thickness of the charge transport layer is 1 to 12 μm, more preferably 5 to 5.
10 μm is preferable. When the total thickness of the charge generation layer and the charge transport layer is 12 μm or less, a remarkable effect of improving the image quality appears. The charge generation layer preferably contains 10 to 100% by weight, more preferably 40 to 400% by weight, of the charge generation material based on the total weight of the charge generation layer. It is preferable to contain the transport substance in an amount of 20 to 80% by weight, and further 30 to 70% by weight.

The electrophotographic photosensitive member of the present invention is formed by forming a film on a support by combining the material used for the photosensitive layer with vacuum deposition or a suitable binder resin. As the binder resin, for example, polyvinyl acetal, polycarbonate,
Preferred binder resins include polystyrene, polyester, polyacetic acid ester, polymethacrylic acid ester, acrylic resin, and cellulose resin.

In the electrophotographic photosensitive member of the present invention, a protective layer may be provided on the photosensitive layer. The protective layer is mainly made of resin. Examples of the material for forming the protective layer include polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene and polycarbonate.
, Polyamide, polypropylene, polyimide, polyamide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin, silicone resin, epoxy resin, urea resin, allyl resin,
Examples thereof include alkyd resin and butyral resin. The thickness of the protective layer is preferably 0.05 to 15 μm, more preferably 1 to 10 μm.

The electrophotographic photoreceptor of the present invention can realize stable potential characteristics and good image formation in all environments from low temperature and low humidity to high temperature and high humidity.

The electrophotographic photosensitive member of the present invention can be used not only in an electrophotographic copying machine but also in a laser beam printer, C.
RT printer, LED printer, LCD printer,
It can also be widely used in electrophotographic application fields such as facsimile and laser plate making.

The present invention integrally supports the electrophotographic photoreceptor of the present invention and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means, and is detachably attached to the main body of the electrophotographic apparatus. It is composed of a process cartridge characterized by being flexible.

The present invention also comprises an electrophotographic apparatus characterized by having the electrophotographic photosensitive member of the present invention, a charging means, an image exposing means, a developing means and a transferring means.

FIG. 1 shows a schematic structure of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photoreceptor of the present invention, which is driven to rotate at a predetermined peripheral speed in the direction of an arrow around a flick 2. In the rotation process, the photosensitive member 1 is uniformly charged at a predetermined positive or negative potential on the peripheral surface thereof by the primary charging means 3, and then the image exposure means (such as a slit exposure or a laser beam scanning exposure) is used. (See FIG. 1). Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then developed.
The toner-developed toner image developed and developed by the transfer material 7 is fed from a sheet feeding unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1. Then, the image is sequentially transferred by the transfer means 6. The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out as a copy (copy) outside the apparatus. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the transfer residual toner by the cleaning means 9, and further subjected to a static elimination process by the pre-exposure light 10 from the pre-exposure means (not shown). After that, it is repeatedly used for image formation. When the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 are integrally connected as a process cartridge. Alternatively, the process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging means 3, the developing means 5 and the cleaning means 9 is integrally supported together with the photoconductor 1 to form a cartridge, and a guide means such as a rail 12 of the apparatus main body is used. The process cartridge 11 can be detachably attached. When the electrophotographic apparatus is a copier or a printer, the image exposure light 4 uses reflected light or transmitted light from the original, or reads the original with a sensor and converts it into a signal. This is light emitted by scanning of the laser beam, driving of the LED array, driving of the liquid crystal shutter array, and the like.

On the other hand, when used as a printer for a facsimile, the image exposure light 4 becomes exposure light for printing the reception data. FIG. 2 is a block diagram showing an example of this case. The controller 14 controls the image reading unit 13 and the printer 22. The entire controller 14 is controlled by the CPU 20. The read data from the image reading unit 13 is transmitted to the partner station through the transmission circuit 16. The data received from the partner station is sent to the printer 22 through the receiving circuit 15. Predetermined image data is stored in the image memory. The printer controller 21 controls the printer 22. 17
Is a telephone. The image received from the line 18 (image information from the remote terminal connected via the line) is demodulated by the receiving circuit 15, and then the image information is decoded by the CPU 20 and sequentially stored in the image memory 19. To be done. When the image of at least one page is stored in the image memory 19, the image of the page is recorded. The CPU 20 reads out the image information of one page from the image memory 19 and sends out the decoded image information of one page to the printer-controller-21. When receiving the image information of one page from the CPU 20, the printer controller 21 controls the printer 22 to record the image information of the page. CPU 20
Is receiving the next page during recording by the printer-22. In this way, the image is received and recorded.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electrophotographic photosensitive member of the present invention is prepared, for example, as follows.

On an aluminum cylinder, an anodic oxide film was formed by using sulfuric acid as an electrolyte, and a sealing treatment was carried out by using nickel acetate as a pore-sealing agent. On a support, oxytitanium phthalocyanine pigment, polyvinyl butyral, cyclohexanone and tetrahydrofuran were formed. To form a charge-generating layer, and then a triarylamine compound as a charge-transporting substance and a polycarbonate are formed.
A coating liquid for a charge generation layer using chlorobenzene and chlorobenzene is applied on the charge generation layer to form a charge transport layer, thereby preparing an electrophotographic photoreceptor.

The cartridge of the present invention integrally supports the electrophotographic photosensitive member of the present invention and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means. It is designed to be removable from the body of the photographic device.

In the electrophotographic apparatus having the process cartridge having the electrophotographic photosensitive member of the present invention, the drum-shaped electrophotographic photosensitive member of the present invention is rotationally driven at a predetermined peripheral speed. In the course of rotation of the photosensitive member, its peripheral surface is uniformly charged with a predetermined positive or negative potential by the primary charging means, and then image exposure from the image exposing means such as slit exposure or laser beam scanning exposure is performed. Upon receiving light, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor, and the formed electrostatic latent image is then toner-developed by the developing means.
The developed image is sequentially transferred by the transfer means to the transfer material fed from the paper supply section between the photoconductor and the transfer means in synchronization with the rotation of the photoconductor. The transfer material having undergone the image transfer is separated from the photoreceptor surface, introduced into an image fixing means, and subjected to image fixing to be printed out as a copy (copy) outside the apparatus. The surface of the photoreceptor after image transfer is clean.
After the transfer residual toner is removed by the polishing means, the surface is cleaned, and after being subjected to a static elimination treatment by the pre-exposure light from the pre-exposure means, it is repeatedly used for image formation.

[0037]

【Example】

Example 1 An aluminum oxide film having a thickness of 1 mm, a length of 254 mm and a diameter of 30 mm was formed on the surface of an aluminum cylinder with sulfuric acid as an electrolyte to form an anodized film having a thickness of 7 μm, and nickel acetate was used as a sealing agent. The material subjected to the sealing treatment was used as a conductive support.

Next, 4 parts by weight of oxytitanium phthalocyanine pigment, polyvinyl butyral (trade name BX-1,
Sekisui Chemical Co., Ltd.) 2 parts by weight, cyclohexanone 3
A mixed solution consisting of 4 parts by weight was dispersed by a sand mill for 10 hours, and then 60 parts by weight of tetrahydrofuran was added to prepare a coating liquid for charge generation layer. This coating solution is dip-coated on the aluminum support on which the anodic oxide film is formed, and 90
By heating and drying at 10 ° C. for 10 minutes, a charge generation layer having a film thickness of 0.2 μm was formed.

Next, 50 parts by weight of a triarylamine compound represented by the following structural formula:

Embedded image A solution prepared by dissolving 50 parts by weight of polycarbonate (Yupiron Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) in 400 parts by weight of chlorobenzene was dip-coated on the charge generation layer, and the temperature was 110 ° C. Heat dried for 1 hour at a film thickness of 11.5μ
A charge transport layer of m was formed to prepare an electrophotographic photoreceptor.

The prepared electrophotographic photosensitive member is mounted on an electrophotographic printer of reversal development, and charging (in this embodiment, the charging method is a contact charging process by a charging roller) -exposure-development-transfer- The cleaning process was repeated with a 6 second cycle. This photoreceptor is kept at low temperature and low humidity (15 ℃, 15
% RH) and high temperature and high humidity (30 ° C., 80% RH) environment, the electrophotographic characteristics were evaluated. As a result, as shown in Table 1, this electrophotographic photosensitive member was able to obtain a large contrast between the dark portion potential (Vd) and the light portion potential (Vl) even at low temperature and low humidity and high temperature and high humidity. Further, even in the result of continuous running of 5000 sheets, neither the dark part potential nor the light part potential changes substantially under both low temperature and low humidity and high temperature and high humidity environments. In addition, an extremely high-quality image having no unnecessary black-spot image or fogging and no toner scattering was obtained.

[Table 1]

Example 2 A polar oxide film was formed on the surface of an aluminum cylinder having a thickness of 1 mm, a length of 260.5 mm and a diameter of 30 mm in the same manner as in Example 1, and then, Example 1 was used. A charge generation layer and a charge transport layer were formed in the same manner as in (1) to prepare an electrophotographic photoreceptor.

The electrophotographic photosensitive member thus prepared was mounted on a reversal developing electrophotographic printer whose charging method was corona charging, and the electrophotographic characteristics were evaluated in the same manner as in Example 1. As a result, as shown in Table 2, this electrophotographic photosensitive member has a dark part potential (Vd) at low temperature and low humidity and high temperature and high humidity.
It was possible to obtain a large contrast between the light potential and the bright part potential (Vl). Further, even in the result of the continuous running of 5000 sheets, neither the dark part potential nor the bright part potential changes substantially under both the low temperature and low humidity environment and the high temperature and high humidity environment.
In addition, an extremely high-quality image having no unnecessary black-spot image or fogging and no toner scattering was obtained.

[Table 2]

Example 3 In the aluminum cylinder used in Example 1, oxalic acid was used as an electrolytic solution for anodic oxidation, and a conductive support having an anodized film of 5 μm in thickness was used. An electrophotographic photoreceptor was prepared in the same manner as in Example 1. The electrophotographic photosensitive member was evaluated by measuring the dark part potential (Vd) and the light part potential (Vl) under low temperature and low humidity and high temperature and high humidity using an electrophotographic printer of reversal development similar to that in Example 1. Image evaluation was performed. In either environment, a sufficiently large contrast could be obtained between the dark part potential and the light part potential, and a very excellent high-quality image without black spot images or fog was obtained. Low temperature and low humidity (15 ° C, 15% RH) Vd: -700V Vl: -150V High temperature and high humidity (30 ° C, 80% RH) Vd: -695V Vl: -145V

Example 4 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the thickness of the anodic oxide film was 10 μm. The electrophotographic photosensitive member was evaluated by measuring the dark part potential (Vd) and the light part potential (Vl) under low temperature and low humidity and high temperature and high humidity using an electrophotographic printer of reversal development similar to that in Example 1. Image evaluation was performed. In either environment, a sufficiently large contrast could be obtained between the dark part potential and the light part potential, and a very excellent high-quality image without black spot images or fog was obtained. Low temperature and low humidity (15 ° C, 15% RH) Vd: -700V Vl: -145V High temperature and high humidity (30 ° C, 80% RH) Vd: -695V Vl: -140V

Example 5 An electrophotographic photosensitive member was prepared in the same manner as in Example 3 except that the thickness of the charge transport layer was 8 μm. The electrophotographic photosensitive member was evaluated by measuring the dark part potential (Vd) and the light part potential (Vl) under low temperature and low humidity and high temperature and high humidity using an electrophotographic printer of reversal development similar to that in Example 1. Image evaluation was performed. Even in the region where the charge transport layer thickness is extremely thin,
It was possible to obtain a sufficiently large contrast between the dark part potential and the bright part potential, and a very excellent high-quality image without a black spot image or fog was obtained. When the electrophotographic photoconductor of Example 1 and the electrophotographic photoconductor of this Example are used to compare the resolution (image) of the image (character), sharpness, and the like, the image quality of the present Example having a thinner photoconductor film is compared. Is excellent. Low temperature and low humidity (15 ° C, 15% RH) Vd: -690V Vl: -150V High temperature and high humidity (30 ° C, 80% RH) Vd: -690V Vl: -145V

Comparative Examples 1 and 2 10 parts by weight of copolymerized nylon (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) was added to 60 parts by weight of methanol on an aluminum cylinder having a thickness of 1 mm, a length of 254 mm and a diameter of 30 mm. And a coating solution prepared by dissolving 40 parts by weight of n-butanol in a mixed solution were applied by dip coating, and dried by heating at 90 ° C. for 10 minutes to form an undercoat layer having a thickness of 1 μm. next,
An electrophotographic photoreceptor (Comparative Example 1) in which a charge generation layer and a charge transport layer were formed in the same manner as in Example 1 and the thickness of the charge transport layer was 10 μm, and an electron in which the thickness of the charge transport layer was 12 μm A photographic photoreceptor (Comparative Example 2) was prepared.

The evaluation of electrophotographic characteristics was carried out in the same manner as in Example 1. The results are shown in Table 3. The electrophotographic photosensitive member of Comparative Example 1 has large fluctuations in the dark portion potential (Vd) and the light portion potential (Vl) during repeated use due to the continuous running of 5000 sheets, and also has no potential recovery property.

[Table 3]

Comparative Example 3 A charge generation layer and a charge transport layer were formed in the same manner as in Example 1 on an aluminum cylinder whose surface was cut (surface roughness: R _Z = 0.5 μm), and charge transport was performed. An electrophotographic photosensitive member having a layer thickness of 10 μm was prepared.

The evaluation of electrophotographic characteristics was carried out in the same manner as in Example 1. The results are shown in Table 4. The electrophotographic photosensitive member of Comparative Example 3 has large fluctuations in the dark portion potential (Vd) and the light portion potential (Vl) during repeated use due to the continuous running of 5000 sheets. In addition, a fog, which is considered to be due to charge injection from the support by a thin film, and a black spot, which is considered to be due to protrusions on the aluminum surface, were generated, and a poor quality image was obtained.

[Table 4]

[0050]

According to the present invention, even if the thickness of the photosensitive layer of the electrophotographic photosensitive member is thinned, a sufficient contrast potential can be obtained under both low temperature and low humidity and high temperature and high humidity conditions, and the repetitive It is possible to obtain an extremely stable image without potential fluctuation due to use and without black spots or fog. Further, in the electrophotographic photosensitive member of the present invention, since the film thickness of the photosensitive layer is less than 12 μm, the potential distribution of the electrostatic latent image formed on the surface of the photosensitive member is sharp and the developer distribution on the surface of the photosensitive member after development and The image density after transfer is also sharp, and a remarkable effect that a sharp image with high resolution can be obtained is exhibited. Also, it can be mounted on a process cartridge and an electrophotographic apparatus to achieve the same excellent effects.

[Brief description of drawings]

FIG. 1 is a process car having an electrophotographic photoreceptor of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a cartridge.

FIG. 2 is a diagram showing an example of a facsimile block having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 1 Electrophotographic Photoreceptor of the Present Invention 2 Axis 3 Primary Charging Means 4 Image Exposure Light 5 Developing Means 6 Transfer Means 7 Transfer Material 8 Image Fixing Means 9 Cleaning Means 10 Pre-Exposure Light 11 Process Cartridge 12 Rails 13 Image reading unit 14 Controller 15 Receiver circuit 16 Transmitter circuit 17 Telephone 18 Line 19 Image memory 20 CPU 21 Printer-Controller 22 Printer-

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on an aluminum support, wherein the thickness of the photosensitive layer is less than 12 μm, and the aluminum support has an anodic oxide film. Photoconductor. 2. The electrophotographic photosensitive member according to claim 1, wherein the film thickness of the photosensitive layer is less than 10 μm. 3. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is a laminated photoreceptor having a charge generation layer and a charge transport layer. 4. The electrophotographic photosensitive member according to claim 1, wherein the thickness of the anodic oxide film on the aluminum support is in the range of 1 to 15 μm. 5. The electrophotographic photosensitive member according to claim 1, and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit are integrally supported, and are detachably attached to the main body of the electrophotographic apparatus. A process cartridge characterized by the following. 6. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposure unit, a developing unit and a transfer unit.