JPH0980792A - Electrophotographic photoreceptor, process cartridge having the same, and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the mechanical strength, while having solvent cracking resistance, and to improve the resistant characteristic direct electrification and to facilitate manufacture by incorporating a specified polymer in a surface layer. SOLUTION: The surface layer of the electrophotographic photoreceptor having a photosensitive layer on a conductive substrate scontains a polymer having structural units represented by the formula in which each of R1 -R16 is H or a halogen atom or an optionally substituted alkyl or the like; and X is an optionally substituted alkylene group or -O- or the like. Both of a polymers consisting of the same structural units and a polymer consisting of >=2 kinds of different structural units may be used. Consequently, an especially excellent solvent cracking resistance and mechanical strength and resistant characteristic in the AC charging can be obtained in combination and superior electrophotographic characteristics can be ensured.

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 An electrophotographic method is disclosed in US Pat.
As described in Japanese Patent Publication No. 91-91, a photoconductive material whose electric resistance changes according to the amount of irradiation received during image exposure and which is composed of a support coated with an insulating substance in a dark place is used. . The basic characteristics required for an electrophotographic photosensitive member using this photoconductive material are (1) being capable of being charged to a potential in a dark place, (2) having little potential dissipation in a dark place, (3) For example, it is possible to rapidly dissipate the electric charge by light irradiation.

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

In order to overcome the drawbacks of inorganic photoconductors, electrophotographic photoconductors using various organic photoconductive compounds as main components have been actively developed in recent years. For example, U.S. Pat. No. 3,837,851 discloses a photoreceptor having a charge transport layer containing triallyl pyrazoline, U.S. Pat. No. 38718.
In JP-A-80, there is known a photoconductor comprising a charge generation layer containing a derivative of a perylene pigment and a charge transport layer containing a condensation product of 3-propylene and formaldehyde.

Further, the organic photoconductive compound can freely select the photosensitive wavelength region of the electrophotographic photosensitive member by the compound. For example, in the case of azo pigment, JP-A-61-2
The substances described in JP-A-72754 and JP-A-56-167759 are disclosed to have high sensitivity in the visible region, and JP-A-57-19576 and JP-A-61-228453. It is disclosed that the compounds described in the publication have sensitivity in the infrared region. Of these materials, those showing sensitivity in the infrared region are used in laser beam printers (hereinafter abbreviated as LBP) and LED printers, which have made remarkable progress in recent years, and their demand frequency is increasing. There is.

An electrophotographic photoreceptor using these organic photoconductive compounds is used as a function-separated photoreceptor in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical characteristics. It is often done.

On the other hand, as a matter of course, the electrophotographic photosensitive member is required to have sensitivity, electric characteristics and optical characteristics according to the electrophotographic process applied. Particularly in an electrophotographic photosensitive member that is repeatedly used, an electric or mechanical external force such as corona or direct charging, image exposure, toner development, transfer process, surface cleaning is directly applied to the surface of the electrophotographic photosensitive member. Therefore, durability against them is also required.

Specifically, electrical deterioration due to ozone and nitrogen oxides during charging, mechanical deterioration such as surface abrasion and scratches due to discharge during charging and rubbing of a cleaning member. However, durability against electrical deterioration is required.

The electrical deterioration is particularly problematic in that the carrier stays in the light-irradiated portion and a potential difference occurs between the light-irradiated portion and the non-irradiated portion, which occurs in the photo memory. Mechanical deterioration is often different from inorganic photoreceptors in that many of them are soft in terms of material. Similar to organic photoreceptors, durability against mechanical deterioration is inferior, and improvement in durability is particularly desired.

Various attempts have been made to satisfy the durability characteristics required for the electrophotographic photosensitive member as described above. Polycarbonate resin having a skeleton of bisphenol A has attracted attention as a good resin which is often used for the surface layer and has good wear properties and electric characteristics, but all of the above problems can be solved. However, it 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 low boiling points, When a photoconductor is manufactured using a coating liquid prepared with these solvents, the coated surface is likely to be whitened. It also takes time to control the solid content of the coating liquid.

(2) It is partially soluble in tetrahydrofuran, dioxane, cyclohexanone or a mixed solvent thereof in solvents other than halogenated aliphatic hydrocarbons, but the solution gels in a few days and so on. It has poor properties and is not suitable for photoconductor production.

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

(4) In addition, in the case of the conventional polycarbonate resin, the film formed of the resin does not have lubricity, so that the photoreceptor is easily scratched and the abrasion amount of the electrophotographic photoreceptor is reduced. In the cleaning setting, an image defect may occur, a cleaning failure may occur due to early deterioration of the cleaning blade, and toner fusion may occur.

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

Regarding the solvent crack, as disclosed in JP-A-6-51544 and JP-A-6-75415, silicon-modified polycarbonate is used.
It is possible to solve this problem by using a polyester or ether modified polycarbonate. However, these modified polycarbonates have a structure having flexibility with respect to internal stress in the polymer in order to prevent solvent cracks, as compared with conventional polycarbonate resins. For,
As a result, there is a drawback that the mechanical strength inherent to the polymer is lowered.

Furthermore, in recent years, a method in which a voltage is directly applied to a charging member and an electric charge is applied to an electrophotographic photoreceptor as disclosed in JP-A-57-17826 and JP-A-58-40566 has become mainstream. It's starting. 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, and the amount of ozone generated is much smaller than that of a scorotron or the like. The scorotron is wasted because about 80% of the current passed through the charger flows in the shield, but direct charging has the merit that it is very economical without such waste. But,
The direct charging has a drawback that the charging stability is very poor because it is charged by the discharge according to Paschen's law. As a countermeasure, a so-called AC / DC in which an AC voltage is superimposed on a DC voltage
A charging method has been proposed (Japanese Patent Laid-Open No. 63-149668).
Issue).

Although this charging method improves the stability during charging, the discharge amount on the surface of the electrophotographic photosensitive member is greatly increased due to the superposition of AC, and the scraped amount of the electrophotographic photosensitive member is increased. A new drawback is caused, and not only mechanical strength but also electrical strength is required.

[0019]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems that existed when a conventional polycarbonate resin was used as the surface layer, and to provide mechanical resistance while having solvent crack resistance. (EN) Provided is a photographic photosensitive member which has high strength, good electric resistance property by direct charging, and is easy to manufacture. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

[0020]

The present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the surface layer of the electrophotographic photosensitive member has a constitutional unit represented by the following formula (1). The electrophotographic photosensitive member is characterized by containing a polymer. Equation (1)

Embedded image In the formula, R _{1 to} R ₁₆ represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted alkylene group, and X is substituted. Also represents an alkylene group, —O—, or —S—.

Regarding the polymer having the constitutional unit represented by the following formula (1) contained in the surface layer of the electrophotographic photoreceptor of the present invention, specific examples of the constitutional unit are shown in Table 1. It is not limited.

[Table 1]

Preferred examples include structural unit examples 1, 2 and 3, with structural units 1 and 2 being particularly preferred.

The polymer having the structural unit represented by the above formula (1) can be synthesized by polymerizing the bisphenol represented by the following formula (2) in the presence of phosgene gas. Equation (2)

Embedded image In the formula, R _{1 to} R ₁₆ represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted alkylene group, and X is substituted. Also represents an alkylene group, —O—, or —S—.

In the electrophotographic photosensitive member of the present invention, even a polymer having the same constitutional unit represented by the formula (1) is composed of two or more different constitutional units represented by the formula (1). The polymer may be Further, the copolymer may be prepared with other general bisphenols such as bisphenol Z, bisphenol A, bisphenol C, and bisphenol AF in consideration of solubility at the time of polymerization. However, in this case, the structural unit represented by the formula (1) is preferably present in an amount of 10 to 90 mol%, more preferably 20 to 50 mol%, based on the whole polymer.

The electrophotographic photosensitive member of the present invention has particularly excellent solvent crack resistance, mechanical strength, and electric resistance characteristics under AC charging, and has excellent electrophotographic characteristics.

The polymer in the present invention contains a unit having rigidity in the constitutional unit, and the unit is partially vitrified at the time of producing the electrophotographic photosensitive member to improve the durability of the entire polymer coating. Is. In addition, it is possible to increase the intramolecular density by partially vitrifying the inside of the molecule, and also to alleviate the intramolecular stress generated at the time of forming the coating film because the amorphous part and the crystalline part are combined in the same molecule. Therefore, it is presumed that the internal stress is maintained even if a chemical that causes a solvent crack enters, and the crack does not occur.

A polycarbonate which is simply composed of bisphenol represented by the following formula (3) is disclosed in JP-A-6-214408, but its rigidity is too strong and it tends to become brittle. Formula (3)

Embedded image In order to avoid it, the bisphenol represented by the formula (2)
The use of fluorene increased the degree of freedom in the molecule of the fluorene skeleton and suppressed the brittleness while increasing the strength.

Further, regarding the electric resistance property, it seems that the durability due to electric deterioration is increased due to the influence of the fluorene skeleton, but the details are unknown. Further, it is presumed that the fluorene skeleton and the triallylamine type charge transport material are structurally susceptible to stacking, and the photomemory can be improved.

The constitution of the electrophotographic photosensitive member of the present invention will be described below. The electrophotographic photoreceptor of the present invention may be a single layer type in which the photosensitive layer contains a charge transporting substance and a charge generating substance in the same layer, or a laminated type in which a charge transporting layer and a charge generating layer are separated. The laminated type is preferable from the viewpoint of photographic characteristics.

The conductive support to be used may be any one having conductivity, and examples thereof include metals and alloys such as aluminum and stainless steel, metals provided with a conductive layer, paper, plastic and the like. , Cylindrical and the like. When the image input such as LBP is laser light, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering scratches on the support. This can be formed by dispersing a conductive powder such as carbon black or metal particles in a binder resin. The thickness of the conductive layer is suitably 5 to 40 μm, preferably 10 to 30 μm.

A subbing layer having an adhesive function can be provided on this. Polyamide as the material of the undercoat layer,
Examples include polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are formed by dissolving in a suitable solvent and applying. The thickness of the undercoat layer is 0.05-5 μ
m, preferably 0.3 to 1 μm.

A charge generation layer is formed on the undercoat layer. Examples of the charge generating substance used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanines, anthanthrone, dibenzpyrenequinone, cyanine, trisazo, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. To be In the case of the function-separated type, the charge generation layer comprises a homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, and the charge generation material together with 0.3 to 4 times the amount of the binder resin and solvent. It is formed by well dispersing by a method such as a roll mill and a liquid collision type high speed disperser, applying the dispersion and drying. The thickness of the charge generation layer is 0.
1-2 μm is suitable.

The charge transport layer is formed mainly by coating and drying a coating solution prepared by dissolving a charge transport substance and the binder resin specified in the present invention in a solvent. Examples of the charge transport material used include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, thiazole compounds and the like. These are 0.
It is combined with a binder resin in an amount of 5 to 2 times, coated and dried to form a charge transport layer. The thickness of the charge transport layer is 5 to 5.
40 μm, preferably 15 to 30 μm is suitable.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser printers and CRTs.
It can be widely used in electrophotographic application fields such as printers and electrophotographic plate making systems.

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

Further, the present invention comprises an electrophotographic apparatus comprising the electrophotographic photosensitive member of the present invention, a charging unit, an image exposing unit, a developing unit and a transferring unit.

FIG. 1 shows a schematic structure 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. 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 by the developing means 5.
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 constituent elements such as the photoconductor 1, the primary charging means 3, the developing means 5 and the cleaning means 9 are integrally combined as a process cartridge. However, the process cartridge may be detachably attached to the main body of the 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.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photosensitive member of the present invention is manufactured, for example, as follows.

A coating solution prepared from barium sulfate, titanium oxide, phenol resin, silicone oil, methanol and methoxypropanol treated with SnO ₂ coat was applied on an aluminum support and heat cured. To form a conductive layer, and then a solution of N-methoxymethylated nylon and copolymerized nylon dissolved in a mixed solvent of methanol and n-butanol is applied to form an intermediate layer. Oxytitanium phthalocyanine, polyvinyl butyral and cyclohexanone were dispersed in a sand mill, ethyl acetate was added to prepare a coating solution for the charge generation layer, and the coating solution was applied onto the intermediate layer to form the charge generation layer. Formed. Then, a charge transporting layer coating solution prepared by dissolving an amine compound as a charge transporting substance and a polymer having the above-mentioned constitutional unit example 1 in a mixed solvent of chlorobenzene and dichloromethane is applied on the charge generating layer to produce a charge. The desired electrophotographic photoreceptor can be prepared by forming the transport layer.

Further, for example, as shown in FIG. 1, the electrophotographic photosensitive member may be provided with a process cartridge integrally supporting a primary charging means, a developing means and a cleaning means.

As shown in FIG. 2, as an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention, for example, a printer can be used as a printer in a facsimile.

[0045]

【Example】

Example 1 An aluminum cylinder having a diameter of 30 mm and a diameter of 254 mm was used as a support, and a coating material composed of the following materials was applied onto the support by a dipping method, followed by heating and curing at 140 ° C. for 30 minutes to 15 μm.
Was formed. Conductive pigment: 10 parts of barium sulfate treated with tin oxide coating 10 parts of resistance adjusting pigment: 10 parts of titanium oxide Binder resin: 6 parts of phenol resin Leveling agent: 0.001 part of silicone oil Solvent: methanol / Methoxypropanol 0.2 / 0.
8 to 20 copies

Next, 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon were mixed with 65 parts of methanol and n.
A solution of 30 parts butanol dissolved in a mixed solvent was applied by a dipping method to form an intermediate layer of 0.5 μm.

Next, the diffraction angles 2θ ± 0.2 ° in the X-ray diffraction spectrum of CuKα are 9.0 °, 14.2 °, 2
4 parts of oxytitanium phthalocyanine (TiOPc) having a strong peak at 3.9 ° and 27.1 °, 2 parts of polyvinyl butyral (trade name S-REC BM-2, manufactured by Sekisui Chemical Co., Ltd.) and cyclohexanone 60 Φ1mm
After dispersing with a sand mill using a glass bead for 4 hours, 100 parts of ethyl acetate was added to prepare a coating liquid for a charge generation layer. This coating solution was applied on the intermediate layer by a dipping method to form a charge generation layer having a thickness of 0.3 μm.

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

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

[Chemical 6] 10 parts of the polymer described in Condition 1 of Table 2 below was dissolved in a mixed solvent of 30 parts of chlorobenzene and 70 parts of dichloromethane.

This polymer was prepared from Biphenol (0.03 mol) and bisphenol required for preparing Structural Example 1.
LeZ (0.07 mol) is placed in a four-necked flask and 228 ml of pyridine is added. While stirring, the flask was provided with a gas introduction pipe and a gas discharge pipe, and phosgene was sent in the draft chamber at a rate of 0.25 g / min for 30 minutes. After the introduction of gas was stopped, the mixture was stirred for 20 minutes, 250 ml of methanol was mixed for 5 minutes, and the precipitated polymer was separated by filtration to remove methanol.
After washing in 500 ml of chloroform, once drying, chloroform 5
What was dissolved in 0 ml, dropped into 1 liter of methanol, separated by filtration and dried was used. Final yield 75%.

The prepared coating solution is applied by a dipping method to obtain 120
2 hours at ℃, to form a charge transport layer with a thickness of 25μm,
An electrophotographic photoreceptor was prepared.

[0051]

[Table 2]

Next, the evaluation will be described. The device is
Let Packard LBP "Laser Jet 4plu"
s "(process speed 71 mm / sec) was modified and used. In the modification, the constant voltage control was used as the primary charging control. The prepared electrophotographic photoreceptor is 28 ° C, 90% RH with this device.
Paper feeding was performed below. The sequence was an intermittent mode in which it stopped once for each print. If the toner disappeared, I replenished it and endured until problems appeared in the image.

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

Further, light of a white fluorescent lamp of 3000 lux for 20 minutes was applied to a part of the electrophotographic photosensitive member, and after allowing to stand for 4 minutes, the light portion potential was measured, and how much the light portion potential decreased before the light was applied. Was measured and used as a photo memory value.

Further, regarding the solvent cracking property, the presence or absence of solvent cracking was observed by microscopic observation after allowing finger grease to adhere to the surface of the electrophotographic photosensitive member, and after leaving it for 48 hours (o is present, x is not). Table 3 shows the results.

Examples 2 to 10 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the polymers described in Conditions 2 to 10 in Table 2 were used as the binder resin for the charge transport layer. It evaluated similarly. The results are shown in Table 3.

[0057]

[Table 3]

Comparative Examples 1 to 5 Electrophotographic photoreceptors were prepared in the same manner as in Example 1 except that the polymers described in Comparative Conditions 1 to 5 in Table 4 were used as the binder resin for the charge transport layer. And evaluated. The results are shown in Table 5.

[0059]

[Table 4]

[0060]

[Table 5]

[0061]

The electrophotographic photoreceptor of the present invention has excellent resistance to solvent cracks without impairing mechanical strength, has high mechanical strength, and has good electric resistance characteristics against discharge by direct charging. Therefore, there is a remarkable effect that it is suitable for direct charging, which is easy to manufacture. The effect of the electrophotographic photosensitive member is excellent in the process cartridge and electrophotographic apparatus of the present invention having the electrophotographic photosensitive member.

[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 (3)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the surface layer of the electrophotographic photoreceptor contains a polymer having a structural unit represented by the following formula (1). And an electrophotographic photoreceptor. Formula (1) In the formula, R _{1 to} R ₁₆ represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted alkylene group, and X is substituted. Also represents an alkylene group, —O—, or —S—. 2. The electrophotographic photosensitive member according to claim 1, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably mountable to the main body of the electrophotographic apparatus. A process cartridge characterized by the following. 3. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit and a transfer unit.