JPH10115946A - Electrophotographic photosensitive member, process cartridge provided with the electrophotographic photosensitive member, and electrophotographic apparatus - Google Patents

Abstract

(57) [Problem] An electrophotographic photoreceptor containing an organic photoconductive compound as a main component has poor solvent crack resistance and mechanical strength.
In addition, there is a drawback that electric resistance characteristics due to direct charging are insufficient, and that photo memory and residual potential characteristics are poor. SOLUTION: In an electrophotographic photosensitive member having a conductive support and a photosensitive layer, the surface layer of the electrophotographic photosensitive member contains a polyarylate resin having a repeating unit represented by the following general formula (1), One having a dielectric constant of 2.3 or more is used. Embedded image (X is —CR ₁₃ R ₁₄ — (wherein R ₁₃ and R ₁₄ are each independently a hydrogen atom, an alkyl group which may be substituted, an aryl group, or a divalent alkylidene group extending over R ₁₃ and R ₁₄ ) ), An optionally substituted alkylene group, a fluorene group, a single bond, -O-, -S-, -SO-, or -SO
_2- . R _{1 to} R ₁₂ are each independently a hydrogen atom, a halogen atom, an alkyl group which may be substituted, or an aryl group. )

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to an electrophotographic photosensitive member having a photosensitive layer containing a specific resin, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in U.S. Pat.
As shown in the specification of JP-A-91, a photoconductive material is used in which the electric resistance changes according to the irradiation amount received during image exposure, and in a dark place, the support is coated with an insulating substance. The basic characteristics required of an electrophotographic photoreceptor using this photoconductive material include (1) being able to be charged to an appropriate potential in a dark place, (2) being small in potential dissipation in a dark place, (3) Quickly dissipating the charge by light irradiation.

Heretofore, as an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer mainly containing an inorganic photoconductive compound such as selenium, zinc oxide, and cadmium sulfide has been widely used. However, they satisfy the above conditions (1) to (3), but are not always satisfactory in heat stability, moisture resistance, durability, and productivity.

In order to overcome the disadvantages of inorganic photoreceptors, electrophotographic photoreceptors containing various organic photoconductive compounds as main components have been actively developed in recent years. For example, US Patent No. 38
No. 37851 discloses a photoreceptor having a charge transport layer containing triallyl pyrazoline, US Pat.
No. 80 discloses a photoreceptor comprising a charge generation layer composed of a perylene pigment derivative and a charge transport layer composed of a condensate of 3-propylene and formaldehyde.

Further, the photosensitive wavelength range of the electrophotographic photosensitive member can be freely selected depending on the organic photoconductive compound.
The substances disclosed in JP-A-72754 and JP-A-56-167759 are disclosed to have high sensitivity in the visible region, and are disclosed in JP-A-57-19576 and JP-A-61-76576.
It is described that the compound disclosed in JP-A-228453 has sensitivity up to the infrared region.

Of these materials, those exhibiting sensitivity in the infrared region are used in laser beam printers (hereinafter abbreviated as LBPs) and LED printers, which have been making remarkable progress in recent years.
The demand frequency is increasing.

Electrophotographic photoreceptors using these organic photoconductive compounds are function-separated type photoreceptors in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical properties. Often used. On the other hand, as a matter of course, the electrophotographic photoreceptor is required to have sensitivity, electrical characteristics, and even optical characteristics according to the applied electrophotographic process.

Particularly, in the case of an electrophotographic photoreceptor that is used repeatedly, the surface of the electrophotographic photoreceptor is exposed to an electric or mechanical external force such as corona or direct charging, image exposure, toner development, transfer process, and surface cleaning. Since they are added directly, durability against them is also required.

More specifically, electrical deterioration due to ozone and nitrogen oxides during charging, discharge during charging, mechanical deterioration in which the surface is worn or scratched due to rubbing of a cleaning member, Durability against mechanical deterioration is required.

[0010] The phenomenon of electrical deterioration, in which carriers accumulate in light-irradiated portions and a potential difference from the light-irradiated portions, is a particular problem, which occurs as a photo memory.

The mechanical deterioration is different from the inorganic photoreceptor in particular,
Organic photoconductors, which are often materially soft, have poor durability against mechanical deterioration, and are particularly desired to improve durability.

Various attempts have been made to satisfy the durability characteristics required for the photosensitive member as described above.

[0013]

As a resin which is often used for the surface layer and has good abrasion and electrical properties, a polycarbonate resin having a bisphenol A skeleton has attracted attention. It cannot be solved, but has the following problems.

(1) It has poor solubility and shows good solubility only in a part of halogenated aliphatic hydrocarbons such as dichloromethane and 1,2-dichloroethane, and since these solvents have a low boiling point, When a photoreceptor is manufactured using a coating solution prepared with these solvents, the coated surface tends to be whitened. It takes time to control the solid content of the coating liquid.

(2) Solvents other than halogenated aliphatic hydrocarbons are partially soluble in tetrahydrafuran, dioxane, cyclohexanone or a mixed solvent thereof, but the solution gels in a few days. It is not suitable for photoreceptor manufacture because of poor aging properties.

(3) Even if the above (1) and (2) are further improved, solvent cracks are liable to occur in the polycarbonate resin having bisphenol A as a skeleton.

(4) In addition, in the conventional polycarbonate resin, the coating formed of the resin has no lubricity, so that the photosensitive member is easily damaged, and the cleaning setting is set so as to reduce the abrasion amount of the electrophotographic photosensitive member. In such a case, an image defect such as fusion of toner may occur, or cleaning failure may occur due to early deterioration of the cleaning blade.

Regarding the solution stability mentioned in the above (1) and (2), polycarbonate Z resin having a bulky cyclohexylene group as a polymer structural unit is used or copolymerized with bisphenol Z, bisphenol C or the like. It has been solved by

Solvent cracks can also be solved by using a silicone-modified polycarbonate or an ether-modified polycarbonate as disclosed in JP-A-6-51544 and JP-A-6-75415. is there. However, these modified polycarbonates have a structure that gives flexibility to internal stress in the polymer in order to prevent solvent cracks as compared with conventional polycarbonate resins, and as a result, the mechanical There was a disadvantage that the strength was reduced.

In recent years, as disclosed in JP-A-57-17826 and JP-A-58-40566, a voltage is directly applied to a charging member to apply a charge to an electrophotographic photosensitive member. The charging method is becoming mainstream.

This is a method in which a roller-shaped charging member made of a conductive rubber or the like is directly brought into contact with an electrophotographic photosensitive member to apply an electric charge. In the scorotron, about 80% of the current flowing through the charger is wasted because it flows through the shield, whereas direct charging has the merit that this wasted portion is extremely economical.

However, direct charging has a disadvantage that charging stability is very poor because of charging by discharge according to the Pashton's rule. As a countermeasure, a so-called AC / DC charging system in which an AC voltage is superimposed on a DC voltage has been devised (JP-A-63-149668).

Although this charging method has improved the stability during charging, the amount of discharge on the surface of the electrophotographic photosensitive member is greatly increased due to the superposition of AC, and the shaving amount of the electrophotographic photosensitive member is increased. This leads to a new disadvantage that not only mechanical strength but also electrical strength is required.

An object of the present invention is to solve the above-mentioned problems associated with the electrophotographic photoreceptor having a conventional polycarbonate resin as a surface layer, to provide excellent solvent crack resistance and high mechanical strength, In addition, by providing an electrophotographic photoreceptor that has good electrical resistance due to direct charging, has a small photo memory and residual potential, and does not require much labor to control the solid content of the coating solution. is there.

Another object of the present invention is to provide a process cartridge having the above electrophotographic photosensitive member.

It is still another object of the present invention to provide an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0027]

That is, the present invention relates to an electrophotographic photoreceptor having a conductive support and a photosensitive layer, wherein the surface layer of the electrophotographic photoreceptor has a repeating unit represented by the following general formula (1). Containing a polyarylate resin having
It comprises an electrophotographic photosensitive member having a dielectric constant of 2.3 or more.

[0028]

Embedded image (X is —CR ₁₃ R ₁₄ — (wherein R ₁₃ and R ₁₄ are each independently a hydrogen atom, an alkyl group which may be substituted, an aryl group, or a divalent alkylidene group extending over R ₁₃ and R ₁₄ ) ), An optionally substituted alkylene group, a fluorene group, a single bond, -O-, -S-, -SO-, or -SO
_2- . R _{1 to} R ₁₂ each independently represent a hydrogen atom,
A halogen atom, an alkyl group which may be substituted, and an aryl group. In the present invention, examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the alkylene group include a methylene group and a dimethylene group. Examples of the aryl group include a phenyl group and a naphthyl group. R
_13, R ₁₄ 2 divalent Examples of alkylidene groups cyclohexylidene group over, etc. cyclopentylidene group, and examples of the halogen atom fluorine atom, a chlorine atom, a bromine atom. Examples of the substituent which these may have include a halogen atom, an alkyl group and an aryl group as described above.

Further, the present invention is a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Table 1 shows specific examples of the structural unit represented by the formula 1, but the present invention is not limited to this.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4] Preferred examples include Structural Unit Examples 1, 2, 3, and 7, and particularly Structural Units 1 and 2.

The polymer having a constitutional unit represented by the formula (1) used in the present invention generally contains a terephthalic acid chloride or an isophthalic acid chloride to improve the solubility of the bisphenol represented by the following formula (2). Interfacial polymerization can be carried out by stirring the mixture in a solvent / water system under an alkali.

The ratio between terephthalic acid chloride and isophthalic acid chloride is determined in consideration of the solubility of the polymer, and there is no established theory. However, if any chloride is 30m
It is necessary to pay attention to the fact that the solubility of the synthesized polymer is extremely reduced when the content is less than ol%. Usually, it is preferable to synthesize at a ratio of 1/1.

The polymer having the structural unit represented by the formula (1) used in the present invention has a small dielectric constant,
In particular, those having a dielectric constant of less than 2.3 have poor durability and poor mechanical strength.

The relationship between the structure, the dielectric constant, and the durability is not yet clear, but is under intensive study.

[0039]

Embedded image (X is —CR ₁₃ R ₁₄ — (wherein R ₁₃ and R ₁₄ are each independently a hydrogen atom, an alkyl group which may be substituted, an aryl group, or a divalent alkylidene group extending over R ₁₃ and R ₁₄ ) ), An optionally substituted alkylene group, a fluorene group, a single bond, -O-, -S-, -SO-, or -SO
_2- . R _{1 to} R ₁₂ each independently represent a hydrogen atom,
A halogen atom, an alkyl group which may be substituted, and an aryl group. In the electrophotographic photoreceptor of the present invention, even if the polymer is composed of the same structural unit represented by the formula (1), the polymer may be composed of two or more different types of structural units represented by the formula (1). It may be united.

Hereinafter, the structure of the electrophotographic photosensitive member used in the present invention will be described.

The electrophotographic photoreceptor of the present invention may be a single layer type in which the photosensitive layer contains a charge transport material and a charge generation material in the same layer, or a laminated type in which the charge transport layer and the charge generation layer are separated. Although good, the laminated type is preferable in terms of electrophotographic characteristics.
The conductive substrate to be used may be any one having conductivity, such as aluminum, a metal such as stainless steel, or a metal provided with a conductive layer, paper, plastic, and the like.
Examples of the shape include a sheet shape and a cylindrical shape.

When the image input is a laser beam, such as LBP, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering a scratch on the substrate. This is carbon black. It can be formed by dispersing conductive powder such as metal particles in a binder resin. The thickness of the conductive layer is 5
40 μm, preferably 10 to 30 μm is suitable.

An intermediate layer having an adhesive function is provided thereon. Examples of the material of the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are applied by dissolving in an appropriate solvent. The thickness of the intermediate layer is 0.05 to 5 μm, preferably 0.1 to 5 μm.
3 to 1 μm is appropriate.

The charge generation layer is formed on the intermediate layer.
As the charge generating substance used in the present invention, selenium-tellurium, pyrylium, thiapyrylium-based dye, phthalocyanine, anthantrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, asymmetric quinocyanine-based pigments. No. In the case of the function-separated type, the charge generation layer comprises a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill, and a liquid collision with the charge generation material together with a binder resin and a solvent in an amount of 0.3 to 4 times. It is formed by dispersing well by a method such as a mold high-speed disperser, applying a dispersion, and drying. The thickness of the charge generation layer is 5 μm
Hereinafter, preferably, 0.1 to 2 μm is appropriate.

The charge transport layer is formed by coating and drying a coating material in which a charge transport material and a binder resin are dissolved in a solvent. Examples of the charge transport material used include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds,
Triarylmethane-based compounds, thiazole-based compounds and the like can be mentioned.

These are combined with 0.5 to 2 times the amount of the binder resin, applied and dried to form a charge transport layer. The thickness of the charge transport layer is 5 to 40 μm, preferably 15 to 30 μm.
μm is appropriate.

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 a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 rotates during the rotation process.
The peripheral surface thereof is uniformly charged with a predetermined positive or negative potential by the primary charging unit 3 and then receives image exposure light 4 from an image exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then transferred to developing means 5
The toner-developed image developed by the toner image is transferred from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed to a transfer material 7 fed therefrom. The image is sequentially transferred by the transfer unit 6.

The transfer material 7 which has undergone the image transfer is separated from the surface of the photoreceptor, introduced into the image fixing means 8 and subjected to image fixing to be printed out as a copy out of the apparatus.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 9, and is further subjected to a pre-exposure light 10 from a pre-exposure means (not shown).
Is used for image formation repeatedly after the charge removal processing. 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 above-described electrophotographic photosensitive member 1, primary charging means 3, developing means 5 and 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 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. The process cartridge 11 can be used.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected and 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.

On the other hand, when used as a facsimile printer, the image exposure light 4 becomes exposure light for printing received 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. 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 a remote terminal connected via the line) is demodulated by the receiving circuit 15 and then decoded by the CPU 20 to be sequentially stored in the image memory 19. Is done. When the image of at least one page is stored in the memory 19, the CPU 20 performs image recording of the page. The CPU 20 reads out the image information of one page from the image memory 19, and Sends out image information. The printer controller 21
When receiving one page of image information from the CPU 20, the printer 22 is controlled to record image information of the page. The CPU 20 is receiving the next page during recording by the printer 22.

In this manner, reception and recording of an image are performed.

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,
RT printer, LED printer, LCD printer,
It can be widely used in electrophotographic applications such as laser plate making.

The following is a description of the embodiment.

[0060]

【Example】

[Example 1] A 30φ254 mm Al cylinder was used as a support, and a coating composed of the following materials was applied on the support by a dip coating method, and was thermally cured at 140 ° C for 30 minutes for 15 minutes.
A μm conductive layer was formed.

[0061] conductive pigments: S _n O ₂ coated processing barium sulfate 10 parts resistance adjusting pigment: Titanium oxide 2 parts Binder resin: phenol resin 6 parts Leveling material: silicone oil 0.001 part Solvent: methanol, methoxypropanol 0. 2 / 0.8 20 parts Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol was applied by dipping. A 0.5 μm intermediate layer was formed.

Next, the diffraction angles 2θ ± 0.2 ° in the X-ray diffraction spectrum of CuKα are 9.0 °, 14.2 °, 2 °
TiOPc having strong peaks at 3.9 ° and 27.1 °
4 parts and polyvinyl butyral (trade name: Eslec BM
2, 2 parts of Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed in a sand mill using φ1 mm glass beads for 4 hours, and 100 parts of ethyl acetate was added to prepare a dispersion for a charge generation layer. This was applied by a dip method.
A 3 μm charge generation layer was formed.

Next, 9 parts of an amine compound having the following structural formula

[0064]

Embedded image 1 part of amine compound of the following structural formula

[0065]

Embedded image And 10 parts of the polymer described in Condition 1 of Table 2 were dissolved in a mixed solvent of 30 parts of monochlorobenzene and 70 parts of dichloromethane.

This polymer was prepared from a predetermined biphenol (0.0
Sodium hydroxide (0.8 g), tetramethylammonium chloride (1 g) dissolved in water (100 ml) and charged into a 1-liter mixer, into which 1,2-dichloroethane (30 ml) was added terephthalic acid chloride (0 ml). .0
05mol), isophthalic acid chloride (0.005mo)
l) was added while stirring, and the mixture was stirred at high speed for 10 minutes and left for 2 hours. Then, 5 mol% of p-tert-butylphenol was added to the monomer to stop the terminal carboxyl group, and the mixture was further stirred for 30 minutes. Thereafter, a 1,2-dichloroethane solution was recovered, and a large amount of hexane was added thereto to recover a polymer. In addition, after the recovery, a water purification, chloroform dissolution, purification step by methanol dripping three times was used.

The dielectric constant of the recovered polymer was measured. The dielectric constant of the polymer described in Condition 1 in Table 2 was 3.1.
Met.

This paint was applied by dipping and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer.

Next, the evaluation will be described.

The device is a Hewlett-Packard LBP
"Laser jet 4plus" (process speed 7
1 mm / sec). In the remodeling, primary charging was controlled by constant current control and constant voltage control. The prepared electrophotographic photosensitive member was subjected to paper passing durability at 32 ° C. and 95% RH with this apparatus. The sequence was an intermittent mode in which the printing was stopped once for each print.

When the toner was exhausted, the toner was replenished, and the image was durable until a problem occurred in the image.

Further, abrasion was performed for 15 minutes using a taper abrasion tester using a polishing tape, and the weight loss at that time was measured.

Further, 3000 l of a part of the electrophotographic photosensitive member
After illuminating with a white fluorescent lamp for 10 minutes ux, the light-area potential was measured after standing for 10 minutes, and how much the light-area potential had dropped before the light was applied was determined as a photo memory value.

Further, regarding the solvent cracking property, sebum was adhered to the surface and left for 48 hours, and the presence or absence of solvent cracking was observed under a microscope.

Table 3 shows the results.

[0076]

[Table 5] The mixing ratio between terephthalic acid chloride and isophthalic acid chloride was 1: 1 on a molar basis. [Example 2-12] An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the binder of the charge transport layer used was one of the conditions 2 to 12 shown in Table 2. Table 3 shows the results.

[0077]

[Table 6] [Comparative Example 1-5] An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the binder of the charge transport layer used was one of the conditions 1 to 5 in Table 4. Table 5 shows the results.

[0078]

[Table 7]

[0079]

[Table 8] Next, the laser beam printer “Laser Shot A404” manufactured by Canon was used for the electrophotographic photosensitive members of Examples 1 to 12.
Was attached to the modified equipment and 50% at 32 ° C and 95% RH.
A continuous durability test of 00 sheets was performed. The apparatus sets the charging potential Vd of the dark portion at the time of non-irradiation to -650 V and the potential Vd at the time of laser light irradiation.
1 was set to be -170V. The evaluation was performed by measuring the charged potential Vd of the dark part before and after the endurance irradiation, the potential Vl during the irradiation with the laser beam, and the residual potential Vsl after the pre-exposure. Table 6 shows the results.

[0080]

[Table 9] Further, the electrophotographic photoreceptors of Comparative Examples 1 to 5 were subjected to continuous durability in the same manner as in each example, and evaluated. Table 7 shows the results.

[0081]

[Table 10]

[0082]

The electrophotographic photoreceptor of the present invention has excellent solvent cracking resistance without impairing the mechanical strength, has high mechanical strength, and has good electric resistance against discharge by direct charging. Thus, it has become possible to provide an electrophotographic photoreceptor suitable for direct charging, which has a small residual potential with a photo memory and is easy to manufacture.

[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.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of this 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 Rail 13 Image reading unit 14 Controller 15 Receiving circuit 16 transmitting circuit 17 telephone 18 line 19 image memory 20 CPU 21 printer controller 22 printer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hirotoshi Uesugi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (3)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, wherein the surface layer of the electrophotographic photosensitive member is
An electrophotographic photosensitive member comprising a polyarylate resin having a repeating unit represented by the following general formula (1) and having a dielectric constant of 2.3 or more. Embedded image (X is —CR ₁₃ R ₁₄ — (wherein R ₁₃ and R ₁₄ are each independently a hydrogen atom, an alkyl group which may be substituted, an aryl group, or a divalent alkylidene group extending over R ₁₃ and R ₁₄ ) ), An optionally substituted alkylene group, a fluorene group, a single bond, -O-, -S-, -SO-, or -SO
_2- . R _{1 to} R ₁₂ each independently represent a hydrogen atom,
A halogen atom, an alkyl group which may be substituted, and an aryl group. ) 2. The electrophotographic photoreceptor 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, integrally supporting
A process cartridge that can be attached to and detached from the electrophotographic apparatus main body. 3. An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 1; and a charging unit, an image exposing unit, a developing unit, and a transferring unit.