JP2000122314A - Electrophotographic device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the deterioration of the electrification ability of a photoreceptor, the change of the sensitivity and the wear of the surface layer even when the photoreceptor is repeatedly electrified by incorporating a specified compound into the surface layer of the photoreceptor and specifying the rotational speed of the photoreceptor. SOLUTION: Electrification is carried out with a contact electrifier which impresses a voltage obtained by superposing DC voltage on AC voltage, a p- phenylenediamine compound of the formula is incorporated into the surface layer of a photoreceptor with a photosensitive layer on the electrically conductive substrate and the rotational speed of photoreceptor is regulated to >=90 mm/sec. In the formula, R1 and R2 are each H, an optionally substituted alkyl such as methyl, ethyl or propyl or an optionally substituted aryl such as phenyl, naphthyl or anthryl. The amount of the p-phenylenediamine compound in the surface layer is <=50 wt.%, preferably 0.1-2.5 wt.%, further preferably 1-10 wt.%.

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 having a photosensitive layer on a conductive support, and more particularly to an electrophotographic apparatus having the electrophotographic photosensitive member and a process cartridge.

[0002]

2. Description of the Related Art In recent years, an organic photoconductive material has been widely used as an electrophotographic photosensitive member. this is,
It is largely due to its pollution-free and high productivity. Electrophotographic photoreceptors are widely used in order to satisfy various characteristics required for electrophotography such as electrical characteristics and mechanical characteristics. Used.

The electrophotographic characteristics required of a photoreceptor include required sensitivity, electrical characteristics, optical characteristics, and the like according to an electrophotographic process. Of course, repeated use stability of such characteristics is also important. In other words, the photoreceptor that is used repeatedly must be subjected to electrical and mechanical stresses corresponding to the electrophotographic processes such as corona charging, image exposure, toner development, transfer on paper, and cleaning on the surface layer that is most isolated from the support. Therefore, durability against these factors is required.

[0004] The electrical stress specifically refers to deterioration of the surface due to ozone generated during corona charging, fluctuations in light sensitivity, and the like. This indicates that scratches will occur. Recently, due to advantages such as low ozone, low power, and compactness of the device, a contact charging device, that is, a device in which a charging member is brought into direct contact with the surface of the photoreceptor and a voltage is applied to the surface of the photoreceptor to charge the surface is particularly featured. It has been proposed and widely used in Japanese Patent Application Laid-Open No. 57-17826 and Japanese Patent Application Laid-Open No. 58-40566.

[0005] Charging in this system is performed by applying a voltage of about 1 to 2 KV between the charging member and the photosensitive member and discharging in a minute gap generated between the charging member and the photosensitive member. Therefore, the photosensitive member can be charged by applying a voltage higher than a certain discharge starting voltage between the charging member and the photosensitive member. However, in the method of charging the photoreceptor using only the DC voltage, a change in the temperature or humidity of the charging atmosphere directly changes the resistance of the charging member, and the photoreceptor repeatedly operates. It was difficult to keep the charging potential constant because of the scraping during use and an increase in the capacitance of the photoreceptor.

[0006] Therefore, in order to achieve uniform charging, a system disclosed in Japanese Patent Application Laid-Open No. 63-149669, in which an AC voltage is superimposed on a DC voltage corresponding to a charging voltage to perform charging, is widely used. It became like. By applying the AC voltage, the number of surface charges is averaged, and the surface potential of the photoconductor converges to the DC voltage value, so that a constant charging potential can be obtained without being influenced by the external environment or the change in capacity. .

In the contact charging method, an elastic conductive roller is often used as a charging member because of the stability and safety of the device. As described above, since the charging is performed by the discharge in the minute gap generated between the charging roller and the photosensitive member, the amount of generated ozone is small, and the charging can be performed with low power.

However, even in this charging method, the essential charging mechanism remains unchanged, and the charging is performed by utilizing the discharge phenomenon from the charging member to the photosensitive member, so that a small amount of ozone is generated. Also, in this system, since the discharge utilizes a minute space, the overall ozone concentration is low, but the ozone concentration in the minute space where the discharge is occurring is extremely high, and the surface of the photoreceptor has In terms of damage received by high concentration ozone, it is more than corona discharge. Furthermore,
In a charging method in which an AC voltage is superimposed for uniform charging, the discharge current amount is further increased, and an increase in the amount of ozone generated and further deterioration of the photoreceptor by ozone are problematic.

In general, when a contact charging method is applied to a conventional function-separated type organic photoreceptor, repeated use thereof causes a reduction in chargeability, a change in sensitivity, and an abrasion of a charge transport layer. In comparison, the life of the photoconductor becomes extremely short. Conventionally, these are caused by the fact that in a charge transport layer in which a low-molecular charge transport material is dispersed in a binder resin, charges directly flow locally at the time of contact charging, so that stress is applied not only to the surface of the photoreceptor but also to the inside thereof. It has been considered that the method of applying not only a DC voltage but also an AC voltage promotes the deterioration of the charge transporting material and the binder resin to a deeper layer.

However, the present inventors have found that the deterioration of the photosensitive layer due to the contact charging method is not caused by the stress caused by the charge flowing through the photosensitive layer, but is mainly due to the change in the physical properties of the photosensitive layer exposed to high concentration ozone. I found it. That is, in the case where the organic photoconductive material as described above is used, the damage due to ozone due to the contact charging method in which an AC voltage is superimposed is particularly remarkable, and the problem that the photosensitive layer is deteriorated when repeatedly used is further increased. there were.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a contact charging device in which an AC voltage is superimposed on a DC voltage, and the charging property is improved even when the electrophotographic photosensitive member having a resin as a surface layer is repeatedly charged. It is an object of the present invention to provide an electrophotographic apparatus and a process cartridge which can suppress a reduction in sensitivity, a change in sensitivity, and abrasion of a surface layer.

[0012]

According to the present invention, an electrophotographic photoreceptor, charging means for charging the photoreceptor, image exposure means for exposing the charged photoreceptor to form an electrostatic latent image, and static electricity In an electrophotographic apparatus provided with a developing unit for developing a photoreceptor on which an electrostatic latent image is formed with a toner, charging is performed by a contact charging device that applies a voltage obtained by superimposing a DC voltage on an AC voltage. The surface layer of the photoreceptor having a photosensitive layer thereon contains a P-phenylenediamine compound represented by the following structural formula (1), and the rotation speed of the photoreceptor is 9
An electrophotographic apparatus and a process cartridge characterized by being at least 0 mm / sec are provided.

[0013]

Embedded image

In the formula, R ₁ and R ₂ represent a hydrogen atom, an alkyl group such as a substituted or unsubstituted methyl group, an ethyl group or a propyl group, or an aryl group such as a substituted or unsubstituted phenyl group, a naphthyl group or an anthryl group. Represents a group.

[0015]

Embodiments of the present invention will be described below.

Conventionally, there has been disclosed a technique as disclosed in Japanese Patent Application Laid-Open No. 5-22435 in which various antioxidants are added to a surface layer in order to prevent the surface of the photosensitive layer from being deteriorated by contact charging. This is an attempt to suppress the oxidation phenomenon of the surface layer by utilizing the functions of the antioxidant to suppress generation of radicals, trap radicals, and decompose peroxides.

However, the inventor of the present invention has found that adding only an antioxidant to the surface layer can reduce the deterioration of the surface layer in the contact charging system due to the DC voltage on which the AC voltage is superimposed, especially the potential fluctuation due to repeated use. The insufficiency was confirmed by various studies.

Further, by further studying, by making the rotation speed of the electrophotographic photosensitive member in which P-phenylenediamine is added to the surface layer at a speed of 90 mm / sec or more, contact charging by a DC voltage on which an AC voltage is superimposed is performed. In the system,
It has been found that it is possible to provide an electrophotographic apparatus capable of suppressing a potential change such as a decrease in chargeability and a change in sensitivity in repeated use.

Here, the rotation speed of the electrophotographic photosensitive member is 90 m.
When it is less than m / sec, the change in potential before and after repeated use, especially the change in sensitivity is large, and when another antioxidant is used, even when the process speed is 90 mm / sec or more, it is repeated before and after repeated use. Of the electrophotographic photosensitive member in which P-phenylenediamine was added to the surface layer in the present invention, the rotation speed was 90 mm / sec.
Only the combination having the above speed could produce the above effect.

This is thought to indicate that P-phenylenediamine can efficiently trap ozone before it reaches the deep layer inside the photoreceptor by repeated use. It has not been elucidated yet whether the potential change before and after repeated use could be suppressed by such a synergistic effect.

In the present invention, there is also an effect of reducing the wear of the surface layer. The effect is considered to be more effective than the suppression of the deterioration of the surface layer by the antioxidant function. Not elucidated.

The P-phenylenediamine used in the present invention is 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, N, N′-diphenyl-p
-Phenylenediamine, N, N'-diallyl-p-phenylenediamine, N-phenyl-1,3-dimethylbutyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine and the like. be able to.

The content of the P-phenylenediamine in the surface layer is preferably 50% by weight or less, more preferably 0.1 to 25% by weight, and further preferably 1 to 10% by weight.
% By weight. When the content exceeds 50% by weight,
It is not preferable because the mechanical properties of the surface layer may deteriorate.

When producing the electrophotographic photosensitive member of the present invention,
As the support, those having conductivity itself, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, chromium, titanium, nickel, magnesium, indium, gold, platinum, silver, iron, and the like can be used. .
In addition, aluminum, indium oxide, tin oxide,
A conductive layer formed by depositing gold or the like on a conductive support such as a plastic by vapor deposition or the like, or a conductive layer obtained by mixing conductive fine particles with plastic or paper can be used.

An undercoat layer having an injection blocking function and an adhesion function can be provided between the conductive support and the photoconductive layer.
The undercoat layer can be formed of casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, polyamide, polyurethane, gelatin, or the like. The thickness of the undercoat layer is preferably 0.1 μm to 10 μm, more preferably 0.3 μm to 3 μm. The application of the undercoat layer can be performed by a method such as dip coating, spray coating, or roll coating.

In the present invention, the photosensitive layer may be a single layer type or may have a laminated structure in which a charge transport layer and a charge generation layer are separated in function. The following description will be made with respect to the laminated photosensitive layer.

In the electrophotographic photoreceptor of the present invention, the charge generating layer is obtained by dispersing a charge generating pigment in various binder resins. Specific examples of the pigment that can be used in such a charge generation layer include Sudan Red,
Use azo pigments such as diane blue, quinone pigments such as pyrenequinone and anthantrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, azulhenium salt pigments, copper phthalocyanine pigments having various crystal systems, titanyl phthalocyanine pigments and the like. can do. In addition, a charge generation layer made of an inorganic material such as selenium-arsenic or amorphous silicon may be used. The thickness of such a charge generation layer is preferably 5 μm or less, and most preferably in the range of 0.05 μm to 2 μm.

The charge generation layer is formed by well dispersing the charge generation material together with a binder resin and a solvent by a method such as a homogenizer, an ultrasonic wave, a ball mill, a vibration ball mill, a sand mill, an adrider, a roll mill, and a paint shaker, followed by drying. It is formed. On this occasion,
The ratio (parts by weight) of the charge generation material to the binder resin is preferably from 1: 5 to 5: 1, more preferably from 1: 2 to 3: 1.

The charge transport layer provided on the above-mentioned charge generation layer is formed of a charge transport material and a binder resin. Examples of such charge transporting materials include polycyclic aromatic compounds such as biphenylene, anthracene, pyrene, and phenanthrene; nitrogen-containing cyclic compounds such as indole, carbazole, oxadiazole, and pyrazoline; triarylamine compounds; and hydrazone compounds. And styryl compounds.

The charge transport layer is formed by dispersing or dissolving these charge transporting materials in a binder resin. Specific examples of such resins include polymethyl methacrylate, acrylic resins such as styrene-acryl copolymer, polystyrene, low molecular weight polypropylene, styrene-butadiene rubber, ethylene-vinyl acetate copolymer, vinyl chloride, and acetic acid. Vinyl and their copolymers, petroleum resins, saturated alkyl polyester resins, polyethylene terephthalate resins, polybutylene terephthalate resins, aromatic polyester resins such as polyarylate resins, polyacetals, polycarbonates, polyether sulfones,
Examples thereof include polysulfone, polyphenylene sulfide, and polyetheretherketone. After the charge transporting material and the binder resin are dissolved or dispersed in a suitable solvent, they are coated and formed as a charge transporting layer having a thickness of preferably 5 μm to 40 μm, more preferably 10 μm to 30 μm.

The charge transport layer is formed by dissolving the above-described charge transport material and the binder resin in a solvent and applying the solution. The mixing ratio (parts by weight) of the charge transport material and the binder resin is 3: 1.
１ ： 1: 3, preferably 2: 1１〜1.
1: 2 is more preferred. As the solvent, toluene,
Xylene, or aromatic hydrocarbons such as monochlorobenzene and cyclic ethers, specifically, tetrahydrofuran, tetrahydropyran, 1,4-dioxane and the like,
Examples thereof include halogenated hydrocarbons and ketone compounds.

As a method of applying this solution, specifically, a dip coating method, a spray coating method, a roll coating method, a gravure coating method, and the like are known. In any case, those which can efficiently produce a desired photoreceptor are preferable. For example, for efficient and accurate mass production of drum-shaped electrophotographic photosensitive members, the dip coating method is the best.

After applying and forming this charge transport layer, 10
Air-drying or static drying is performed at a temperature of 200 to 200 ° C., preferably 20 to 150 ° C. for 5 minutes to 5 hours, preferably 10 minutes to 2 hours to obtain a charge transport layer. Further, the stacked photoconductor may have a structure in which a charge generation layer is stacked on a charge transport layer.

Although the construction and the method of forming the electrophotographic photosensitive member have been described in various ways, the rotation speed of the electrophotographic photosensitive member in which P-phenylenediamine is added to the surface layer of the present invention is 90 m.
By setting the speed to m / sec or more, in a contact charging system using a DC voltage on which an AC voltage is superimposed, an electrophotographic apparatus capable of suppressing a change in potential such as a decrease in chargeability and a change in sensitivity in repeated use is provided. The structure of the electrophotographic photoreceptor is not a single layer type, and the effect is remarkable in the laminated photoreceptor system. Further, the charge generation layer contains oxytitanium phthalocyanine, and the charge transport layer has the structural formula (2) or (3). When one or both of a styryl compound and a fluorene compound are contained, the effect is remarkably exhibited.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around an axis 2 at a predetermined peripheral speed in a direction indicated by an arrow. The photoreceptor 1 receives a uniform charge of a predetermined positive or negative potential on the peripheral surface thereof by the primary charging means 3 during the rotation process, and then receives a charge from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure. It receives image exposure light 4. 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 image is developed by the image forming apparatus, and the developed toner-developed image is taken out from a paper feeding unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed.
Are sequentially transferred by the transfer means 6.

The transfer material 7 having undergone the image transfer is separated from the surface of the photoreceptor, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by a cleaning unit 9, and further subjected to a charge removal process by a pre-exposure light 10 from a pre-exposure unit (not shown). Used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 are integrally connected as a process cartridge. 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 unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, which can be attached to and detached from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. Process cartridge 1
It can be 1.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal, and the exposure is performed according to the signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as CRT printers, LED printers, liquid crystal printers, and laser plate making.

The conductive intermediate layer of the electrophotographic photosensitive member according to the present invention can be used regardless of the polarity of the charge, such as positive or negative, or the layer structure of the organic electrophotographic photosensitive member, such as a single-layer structure or a function-separated type. is there.

[0042]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” in the examples indicates parts by weight.

(Example 1) 50 parts of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide,
Phenol resin 25 parts, methyl cellosolve 20 parts, methanol 5 parts, silicone oil (polydimethylsiloxane polyoxyalkylene copolymer, average molecular weight 30
00) 0.002 parts were dispersed in a sand mill using φ1 mm glass beads for 2 hours to prepare a coating for a conductive layer. This paint was applied on an aluminum cylinder having an outer diameter of 30 mm by a dip coating method.
After drying for minutes, a conductive layer having a thickness of 20 μm was formed.

Next, alcohol-soluble copolymerized nylon (trade name: Amilan CM-8000, manufactured by Toray Industries, Inc.) 5
Of a solution in 95 parts of methanol was applied by a dip coating method, and dried at 80 ° C. for 10 minutes to form an undercoat layer having a thickness of 1 μm.

Next, in the characteristic X-ray diffraction of CuKα, the black angles (2θ ± 0.2 °) of 9.0 °, 14.2 °,
3 parts of oxytitanium phthalocyanine having strong peaks at 23.9 ° and 27.1 °, polyvinyl butyral (trade name: Esrec BM2, manufactured by Sekisui Chemical Co., Ltd.) 2
To 35 parts of cyclohexanone and dispersed for 2 hours by a sand mill using φ1 mm glass beads, and then 60 parts of ethyl acetate was added to prepare a coating for a charge generation layer. This paint is applied on the above-mentioned intermediate layer by a dip coating method, and dried at 100 ° C. for 15 minutes.
A 2 μm charge generation layer was formed.

Then, 8 parts of a compound of the following structural formula:

[0047]

Embedded image 2 parts of a compound of the following structural formula:

[0048]

Embedded image N- (p-isopropyl) phenyl-N'-phenyl-p-phenylenediamine 0.3 was added to a solution of 10 parts of a polycarbonate resin (trade name; Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 70 parts of chlorobenzene. Parts were dispersed. This solution was applied on the charge generation layer by a dip coating method and dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 22 μm.

The obtained electrophotographic photosensitive member was mounted on a laser beam printer having a configuration as shown in FIG. 1, and a durability test was evaluated. At this time, the rotation speed of the photoconductor is 9
By setting the AC voltage to 2 KV between peaks and the frequency to 900 Hz with the bias value of the charging roller at 4.3 mm / sec, and setting the DC voltage to -510 V, the dark area potential is set to -5.
00V. Although the details of the evaluation are described in detail in the evaluation section described later, in terms of potential, the chargeability of the photoreceptor and the change in durability of the sensitivity were measured, and the amount of scraping of the photosensitive layer due to the durability was also measured. Table 1 shows the results.

(Embodiment 2) The rotation speed of the photosensitive member is 105 m
An electrophotographic photosensitive member was prepared and evaluated for durability in the same manner as in Example 1 except that m / sec was used. Table 1 shows the results.

Example 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the compound to be added to the charge transport layer was N-phenyl-1,3-dimethylbutyl-p-phenylenediamine. Then, the durability was evaluated. Table 1 shows the results.

Example 4 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that an azo pigment represented by the following structural formula was used instead of oxytitanium phthalocyanine in the charge generation layer, and durability was evaluated. Table 1 shows the results.

[0053]

Embedded image

Example 5 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the compound constituting the charge transport layer was a compound represented by the following structural formula, and durability was evaluated. Table 1 shows the results.

[0055]

Embedded image

Example 6 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the charge transporting layer used was the styryl compound-only charge transporting material shown in Example 1, and the durability was evaluated. Was done. Table 1 shows the results.

(Comparative Example 1) The rotation speed of the photosensitive member was 70.7
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the speed was mm / sec, and the durability was evaluated. Table 1 shows the results.

(Comparative Example 2) Instead of N- (p-isopropyl) phenyl-N'-phenyl-p-phenylenediamine, pentaerythrityl-tetrakis [3- (3,5-di-t- [Butyl-4-hydroxyphenyl) propionate] was prepared in the same manner as in Example 1 to evaluate the durability of the electrophotographic photosensitive member. The results are shown in Table 1.

Comparative Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that N- (p-isopropyl) phenyl-N'-phenyl-p-phenylenediamine was not added to the charge transport layer. Was prepared and the durability was evaluated.
Table 1 shows the results.

Comparative Example 4 The procedure of Example 4 was repeated, except that N- (p-isopropyl) phenyl-N′-phenyl-p-phenylenediamine was not added to the charge transport layer. An electrophotographic photoreceptor was prepared and evaluated for durability. The results are shown in Table 1.

Comparative Example 5 The procedure of Example 5 was repeated, except that N- (p-isopropyl) phenyl-N′-phenyl-p-phenylenediamine was not added to the charge transport layer. An electrophotographic photoreceptor was prepared and evaluated for durability. The results are shown in Table 1.

(Evaluation Method) <Charging Property> The charging property is such that the surface of the photoreceptor is initially biased to −500 V, and the surface potential after endurance is −500.
It is expressed by a potential value that decreases with respect to V, and those with a reduction rate of 10% or less are preferable, and those with a reduction rate of 20% or less are regarded as no problem. Anything more was unsuitable.

<Sensitivity> The sensitivity was evaluated based on the amount of surface potential fluctuation before and after endurance under a light amount of 0.3 μJ / cm ² .
No problem was found within 20%. Anything more was unsuitable.

<Abrasion Amount of Photosensitive Layer> The abrasion amount was determined by using a value obtained by measuring a decrease in thickness of the surface layer before and after endurance, and a ratio when the amount of abrasion in Comparative Example 3 was set to 1, and in other examples, Tables showing durability under the conditions of the comparative example are shown in the table.

[0065]

[Table 1]

[0066]

As described above, an electrophotographic photoreceptor, charging means for charging the photoreceptor, image exposure means for exposing the charged photoreceptor to form an electrostatic latent image, and electrostatic 2. Description of the Related Art In an electrophotographic apparatus provided with a developing unit for developing a photoconductor on which a latent image is formed with a toner, charging is performed by a contact charging device that applies a voltage obtained by superimposing a DC voltage on an AC voltage. The surface layer of the photoreceptor having a photosensitive layer contains a P-phenylenediamine compound represented by the structural formula (1), and the rotation speed of the photoreceptor is 90 mm / sec.
By using the electrophotographic apparatus characterized by the above, it was possible to establish a system in which a change in potential in repeated use, that is, a decrease in chargeability and a change in sensitivity were suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/00 303 G03G 15/00 303 15/02 101 15/02 101 (72) Inventor Hiroki Uematsu Tokyo 3-30-2 Shimomaruko, Ota-ku Canon Inc. (72) Inventor Michiyo Sekiya 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hiroyuki Tanaka 3 Shimomaruko, Ota-ku, Tokyo No. 30-2 F-term in Canon Inc. (reference) 2H003 AA18 BB11 CC05 DD03 2H027 EA01 EC14 ED02 EF09 2H068 AA04 AA19 AA20 AA28 AA34 AA35 BA12 BA13 BA14 BA39 FA02 FA27 FC01 FC05 9A001 BB06

Claims (6)

[Claims] An electrophotographic photosensitive member, a charging unit for charging the photosensitive member, an image exposing unit for performing image exposure on the charged photosensitive member to form an electrostatic latent image, and an electrostatic latent image are formed. In the electrophotographic apparatus provided with a developing means for developing the photosensitive member with toner, the charging is performed by a contact charging device that applies a voltage obtained by superimposing a DC voltage on an AC voltage, and a photosensitive layer is formed on the conductive support. Wherein the surface layer of the photoreceptor comprises a P-phenylenediamine compound represented by the following structural formula (1), and the rotation speed of the photoreceptor is 90 mm / sec or more. Embedded image (Wherein, R ₁ and R ₂ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group) 2. The electrophotographic apparatus according to claim 1, wherein the electrophotographic photosensitive member has a charge generation layer and a charge transport layer on a conductive support. 3. The electrophotography according to claim 2, wherein the charge generation layer of the electrophotographic photosensitive member contains oxytitanium phthalocyanine, and the charge transport layer contains a styryl compound represented by the following structural formula (2). apparatus. Embedded image (Wherein, X represents —CH ₂ —CH ₂ — or —CH ＝ CH—, and R ₃ and R ₄ represent an alkyl group, an aralkyl group, an aromatic ring group or a heterocyclic group which may have a substituent. And R ₅ and R ₆
Represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group which may have a substituent, and Ar ₁ represents an aromatic ring group or a heterocyclic group which may have a substituent.) 4. The electrophotography according to claim 2, wherein the charge generation layer of the electrophotographic photosensitive member contains oxytitanium phthalocyanine, and the charge transport layer contains a fluorene compound represented by the following structural formula (3). apparatus. Embedded image (Wherein, Ar ₂ and Ar ₃ represents an aryl group which may have a substituent, R ₇ and R ₈ represents an alkyl group which may have a substituent, an aralkyl group, an aryl group, R ₉ Represents a hydrogen atom, an alkyl group or an alkoxy group which may have a substituent, a hydroxyl group or a halogen atom) 5. The oxytitanium phthalocyanine of the charge generation layer of the electrophotographic photoreceptor has a Bragg angle (2θ ± 0.2 °) of 9.0 ° in characteristic X-ray diffraction of CuKα,
The electrophotographic apparatus according to claim 2, wherein the electrophotographic apparatus has strong peaks at 14.2 °, 23.9 °, and 27.1 °. 6. An electrophotographic apparatus main body which integrally supports at least one means selected from the group consisting of the electrophotographic photosensitive member according to claim 1, a charging means, a developing means and a cleaning means. A process cartridge which is detachably mounted on a process cartridge.