JPH08234470A - Electrophotographic photoreceptor, process cartridge with the same and electrophotoraphic device - Google Patents

Abstract

PURPOSE: To suppress the accumulation of residual potential even after repeated use, to suppress the deterioration of an image and to ensure superior characteristics by incorporating a curable resin into a protective layer and a resin having a specified glass transition temp. into a photosensitive layer. CONSTITUTION: In the electrophotographic photoreceptor with an electrically conductive substrate, a photosensitive layer on the substrate and a protective layer on the photosensitive layer, a curable resin is incorporated into the protective layer and a resin having >=170 deg.C glass transition temp. is incorporated into the photosensitive layer. The curable resin is a resin obtd. by hardening a soln. contg. a monomer or oligomer or further contg. a polymn. initiator, if necessary, by heating or irradiation with light and the resin is, e.g. acrylic resin, urethane resin, silicone resin or melamine resin. Acrylic resin is preferably used from the viewpoint of curability, appliability and the stability of a coating material.

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, and more particularly to an electrophotographic photosensitive member having a protective layer containing a specific resin and a photosensitive layer containing a specific resin, a process cartridge having the same, and an electronic device. Regarding photographic equipment.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in US Pat. No. 229769.
As shown in the specification of No. 1, a photoconductive material which is insulative in a dark place but whose electric resistance is changed according to the irradiation amount received during image exposure is used. The basic characteristics required for an electrophotographic photoreceptor using this photoconductive material are:
(1) Charging to an appropriate potential in a dark place, (2) Little potential dissipation in a dark place, and (3) quick dissipation of electric charge by light irradiation.

Particularly, since various electric and mechanical external forces by a charging means, an exposing means, a developing means, a transferring means, a cleaning means, etc. are directly applied to the surface of an electrophotographic photosensitive member which is repeatedly used, durability against them is increased. Sex is also required.

Specifically, durability against electrical deterioration due to ozone and nitrogen oxides generated during charging, or mechanical deterioration such as surface abrasion or scratches caused by discharge during charging or rubbing by various members. Sex is required.
In particular, electrophotographic photoreceptors using organic photoconductive materials have relatively low mechanical durability, and their improvement is particularly desired.

In order to satisfy the durability characteristics required for the above-mentioned photoreceptor, attempts have been made to provide a surface protective layer containing a resin as a main component on the surface of the photosensitive layer. For example, JP-A-56-42863 and JP-A-53-10374.
Japanese Patent Publication No. 1 discloses that the hardness and wear resistance are improved by using a protective layer containing a curable resin as a main component.

However, when a curable resin is used as the surface protective layer, especially when the lower photosensitive layer is a photosensitive layer containing a resin as a main component, the protective layer or the protective layer may be formed due to volume contraction occurring when the curable resin is cured. Sometimes, the photosensitive layer was cracked and the resulting image had defects.

As a countermeasure against this crack, Japanese Patent Laid-Open No. 5-1
Japanese Patent Publication No. 00464 discloses a protective layer containing a photocurable resin using an acrylic monomer having a relatively small volume shrinkage, but an electron having more excellent characteristics in terms of residual potential and photomemory. Photoconductors are under consideration.

Particularly in recent years, organic photoreceptors have been used even in high-speed processes for printing 10 or more sheets per minute, and there is a strong demand for improvement in durability during repeated use, especially reduction in residual potential.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photosensitive member having excellent characteristics in which residual potential hardly accumulates even when it is repeatedly used and image deterioration does not easily occur.

Another object of the present invention is to provide an electrophotographic photosensitive member in which a photo memory hardly occurs.

A further object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0012]

That is, the present invention provides an electrophotographic photoreceptor having a conductive support, a photosensitive layer on the conductive support, and a protective layer on the photosensitive layer, wherein the protective layer is a curable resin. And an electrophotographic photosensitive member characterized in that the photosensitive layer contains a resin having a glass transition point of 170 ° C. or higher.

The present invention also provides a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION First, the protective layer will be described.
The curable resin used in the present invention is a resin that is cured by applying heat or irradiating light to a solution containing a monomer or an oligomer, and optionally a polymerization initiator. That is, the protective layer of the present invention is formed by applying the solution on the photosensitive layer and then curing the solution.

Examples of the resin used in the present invention include acrylic resin, urethane resin, silicone resin and melamine resin. Among them, acrylic resin is preferable from the viewpoint of curability, coatability and paint stability. . Preferred examples of the acrylic monomer are shown below, but the acrylic monomer is not limited thereto.

[0016]

[Outside 1]

[0017]

[Outside 2]

[0018]

[Outside 3]

[0019]

[Outside 4]

[0020]

[Outside 5] However, R and R'in the above formula are respectively represented by the following formulas.

[0021]

[Outside 6] In the present invention, two or more kinds of curable resins may be used, and they may be mixed with other resins such as polyester, polycarbonate, polyurethane, silicone resin and alkyd resin and vinyl chloride-vinyl acetate copolymer. Can also be used.

In the present invention, the polymerization initiator may or may not be used, but the technical problem of the present invention is more remarkable when the polymerization initiator is used. The addition amount of the polymerization initiator is preferably 0.1 to 80%, and more preferably 0.5 to 50% with respect to the total weight of the monomers and oligomers. Further, since photocuring generally causes less volume shrinkage during curing than thermosetting, a photopolymerization initiator is preferably used in the present invention. Preferred examples of the photopolymerization initiator that can be used are shown below, but the photopolymerization initiator is not limited thereto.

[0023]

[Outside 7] In the present invention, for the purpose of controlling resistance,
It is preferable to disperse conductive particles such as metal oxide particles in the protective layer. As the conductive metal oxide, zinc oxide,
Tin oxide, titanium oxide, antimony oxide, indium oxide, bismuth oxide, tin oxide doped with indium,
Examples thereof include antimony-doped tin oxide and zirconium oxide. These metal oxides are of one type or two types.
A mixture of two or more species is used. The content of metal oxide particles is
5 to 90% of the total solid content of the protective layer is preferable,
90% is more preferable. If the content of the metal oxide is less than 5%, the resistance as a protective layer may be too high, and if it exceeds 90%, the resistance of the surface layer of the photoconductor tends to be low, resulting in a decrease in charging ability or a pinhole. It may be a cause.

In the present invention, it is preferable to disperse lubricating particles such as tetrafluoroethylene in the protective layer for the purpose of improving surface lubricity and environmental stability.

Further, in the present invention, various coupling agents and antioxidants may be added to the protective layer for the purpose of improving dispersibility, adhesiveness and environmental stability.

The thickness of the protective layer used in the present invention is 0.1.
It is preferably from 10 μm, more preferably from 0.5 to 7 μm.

The protective layer may be applied by any general coating method, but the dip coating method is preferred from the viewpoint of productivity.

Next, the photosensitive layer will be described. A photosensitive layer, preferably a charge transport layer having a charge transport material and a binder resin, is formed below the protective layer. As mentioned above,
It is necessary to reduce the residual potential of the photoconductor. If the resistance of the protective layer is simply reduced, conductive particles may be contained in the protective layer, but the residual potential cannot be sufficiently reduced by itself.

As a result of intensive studies, the inventors of the present invention found a correlation between the resin of the photosensitive layer in contact with the protective layer and the residual potential or the photo memory, and arrived at the present invention. That is, by using a resin having a glass transition point (hereinafter abbreviated as Tg) of 170 ° C. or higher as the binder resin of the photosensitive layer that is in contact with the protective layer, the residual potential can be lowered and the residual potential is accumulated due to durability. It can be avoided.

Although the mechanism of the present invention is not clear, it is considered as follows. When a curable resin is used as the protective layer, the monomer or oligomer of the resin itself acts as an organic solvent and corrodes the photosensitive layer on the coated side. The binder resin in the photosensitive layer is not completely dissolved in the monomer or oligomer, and the photosensitive layer swells only near the interface between the photosensitive layer and the protective layer. As a result, the charge transport material and the polymerization initiator migrate to form an electrical trap, and it is considered that the residual potential does not decrease only by reducing the resistance of the protective layer. Since the charge transport material and the polymerization initiator have a low molecular weight, some migration is thought to occur without fail. Therefore, by using a binder resin having a high Tg to prevent the swelling of the photosensitive layer by increasing the crystallinity of the resin and imparting steric hindrance to the photosensitive layer, the transfer of the charge transport material and the polymerization initiator can be prevented. The present invention has been made in view of the obstacles. This does not simply introduce a bulky group into the structure of the monomer constituting the binder resin to impart steric hindrance, but increases the crystallization-prone portion in the molecule during film formation to form a coating film. It is intended to impart steric hindrance.

In the present invention, Tg is preferably 240 ° C. or lower. This is because if the temperature exceeds 240 ° C., the photosensitive layer tends to crack. The Tg in the present invention can be measured from the DTA curve of the resin by a general method.

From the viewpoint of coatability, the molecular weight is preferably 5,000 to 1,000,000, and more preferably 15,000 to 100,000 in terms of weight average molecular weight.

The resin contained in the photosensitive layer in the present invention is
Any one may be used as long as it has a Tg of 170 ° C. or higher, but a polycarbonate is preferable in terms of solvent resistance and hardness. The polycarbonate used in the present invention is a resin having a carbonic acid ester bond in the main chain, and is preferably a resin obtained by polymerizing a bisphenol compound by a phosgene method or a transesterification method. Thermoplastic resins such as polyester and polystyrene may not have sufficient hardness, and thermosetting resins such as phenol resins and urethane resins have many polar groups, which may adversely affect the sensitivity.

In the present invention, the resin may be used alone or may be used by blending with other resin. However, when the Tg of the other resin is less than 170 ° C., the proportion of the resin having the Tg of 170 ° C. or more is preferably 50% by weight or more based on the total weight of the resin in the layer containing the resin. .

As the charge transport material used together with the above binder resin, various triarylamine compounds,
Examples thereof include hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds and thiazole compounds.

The thickness of the charge transport layer in the present invention is 4 to 3
The thickness is preferably 0 μm, and particularly preferably 5 to 20 μm. The weight ratio of the charge transport material to the resin is preferably 1/10 to 20/10,
It is particularly preferably 5/10 to 10/10.

When the photosensitive layer in contact with the protective layer is the charge transporting layer, the underlying layer is the charge generating layer. The charge generation layer is preferably formed by applying a solution in which a charge generation material is dispersed in a binder resin and drying it, but it may be formed by depositing only the charge generation material.

Examples of the charge generating material include phthalocyanine pigments, azo pigments and anthanthrone pigments, and binder resins include polyester, polyacryl, polyvinylcarbazole, phenoxy resin, polycarbonate, polystyrene, polyvinylacetate,
Examples thereof include polysulfone, polyarylate, vinylidene chloride-acrylonitrilo copolymer, and polyvinyl benzal. The weight ratio of the binder resin to the charge generating material is preferably 1/5 to 5/1, and particularly preferably 1/2 to 3/1.

When the photosensitive layer is a single layer, it is formed by applying a solution prepared by dispersing and dissolving the charge generating material and the charge transporting material described above in a resin having Tg of 170 ° C. or less and drying. be able to.

In the present invention, an intermediate layer having a barrier function and an adhesive function can be provided below the photosensitive layer. Examples of the material of the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane and polyether urethane. This layer can be formed by applying a solution of these dissolved in a suitable solvent and drying. The thickness of the intermediate layer is preferably 0.01 to 5 μm, and particularly preferably 0.1 to 1 μm.

In the present invention, a conductive layer having a function of preventing interference fringes and covering defects of the support can be provided under the intermediate layer. This layer can be formed by applying a solution in which a conductive powder such as carbon black or metal particles is dispersed in various binder resins, and drying. The thickness of the conductive layer is preferably 5 to 40 μm, and particularly preferably 5 to 30 μm.

Examples of the method for applying each of these layers include a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method and a beam coating method.

The conductive support forming each of these layers may be any one having conductivity, and may be a metal such as aluminum, or a metal provided with a conductive layer, plastic, paper or the like. The shape is cylindrical, Examples thereof include a film shape.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in laser beam printers, C
It can be widely used in electrophotographic application fields such as RT printers, LED printers, liquid crystal printers and laser plate making.

FIG. 1 shows a schematic structure of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoconductor 1 rotates during the rotation process.
The peripheral surface of the primary charging means 3 is uniformly charged with a positive or negative predetermined potential, and then image exposure light 4 from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images are 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 image is developed by the toner, and the developed toner-developed image is taken out from a paper feeding unit (not shown) between the photoconductor 1 and the transfer means 6 in synchronization with the rotation of the photoconductor 1 and fed to the transfer material 7, The images are sequentially transferred by the transfer means 6.

The transfer material 7 which has received the image transfer is separated from the surface of the photoconductor and introduced into the image fixing means 8 to undergo the image fixing, and is printed out to the outside of the apparatus as a copy.

The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning means 9 by removing the transfer residual toner, and further pre-exposure light 10 from pre-exposure means (not shown).
It is used for repeated image formation after being neutralized by. If the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not always necessary.

In the present invention, among the constituent elements such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9, a plurality of components are integrally combined as a process cartridge, The process cartridge may be detachably attached to the 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 photoconductor 1 to form a cartridge, and the cartridge can be attached to and detached from the apparatus body by using a guide unit such as a rail 12 of the apparatus body. It can be the process cartridge 11.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected light or transmitted light from the original document, or the original document is read by a sensor and converted into a signal, which is performed in accordance with this signal. Laser beam scanning,
It is the light emitted by driving the LED array and driving the liquid crystal shutter array.

On the other hand, when used as a printer for a facsimile, 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 section 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 a 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. Then, when at least one page of image is stored in the memory 19, the image of that page is recorded. The CPU 20 reads out one page of image information from the image memory 19, and the printer controller 21 decodes the decoded one page of image information. Send image information. The printer controller 21 is
When the image information of one page is received from the CPU 20, the printer 22 is controlled to record the image information of the page. The CPU 20 is receiving the next page during recording by the printer 22.

In this way, the image is received and recorded.

[0056]

EXAMPLES Hereinafter, detailed description will be given according to examples. (Example 1) A paint composed of the following materials was applied onto an aluminum cylinder of 30φ x 260 mm by a dip coating method, and heat-cured at 140 ° C for 30 minutes to form a conductive layer having a thickness of 15 µm.

Conductive pigment: tin oxide-coated titanium oxide: 10 parts (parts by weight; the same applies hereinafter) Pigment for adjusting resistance: titanium oxide: 10 parts Binder resin: phenol resin ...・ ・ ・ ・ 10 parts Leveling agent: Silicone oil ・ ・ ・ ・ ・ ・ 0.001 part Solvent: Methanol / methyl cellosolve = 1/1 ・ ・ 20 parts

Next, on this layer, 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon were mixed with 6 parts of methanol.
A solution dissolved in a mixed solvent of 5 parts and 30 parts of n-butanol was applied by a dip coating method and dried to form an intermediate layer of 0.5 μm.

Next, the Bragg angles 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction are 9.0 °, 14.2 °, 23.
Φ1 mm glass beads mixed with 4 parts of oxytitanium phthalocyanine having strong peaks at 9 ° and 27.1 °, 2 parts of polyvinyl butyral (trade name: S-REC BM-2, manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of cyclohexanone After dispersing for 4 hours with a sand mill using
115 parts of methyl ethyl ketone was added to obtain a charge generation layer dispersion liquid. This was applied onto the intermediate layer by a dip coating method and dried to form a charge generation layer having a thickness of 0.3 μm.

Next, 10 parts of an amine compound having the following structural formula

[0061]

[Outside 8] And sample number 1 polycarbonate 10 in Table 1.
30 parts of monochlorobenzene and 30 parts of dichloromethane
Dissolved in a mixed solvent of 1 part. This coating material was applied onto the above-mentioned charge generation layer by a dip coating method and dried at 110 ° C. for 1 hour to form a charge transport layer having a film thickness of 20 μm.

Next, a preparation liquid for the protective layer was prepared by the following procedure. Antimony-containing tin oxide fine particles with an average particle size of 0.02 μm (trade name: T-1, Mitsubishi Materials Corporation)
Manufactured) 100 parts, (3,3,3-trifluoropropyl)
30 parts and 9 parts of trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
A solution obtained by mixing 300 parts of 5% ethanol-5% aqueous solution with a milling device for 1 hour was filtered,
After washing with ethanol, it was dried and the surface of the tin oxide fine particles was treated by heating at 120 ° C. for 1 hour. Next, as a binder resin, acrylic monomer exemplified compound No. A dispersion liquid in which 25 parts of 23, 0.5 parts of 2-methylthioxanthone as a photopolymerization initiator, 35 parts of the surface-treated antimony-containing tin oxide particles and 300 parts of toluene are mixed and dispersed in a sand mill for 96 hours. To
Tetrafluoroethylene resin particles (trade name: Lubron L-2,
A solution prepared by mixing 25 parts of Daikin Industries, Ltd. was dispersed in a sand mill for 8 hours to obtain a dispersion liquid for a protective layer.

This dispersion was spray-coated on the charge transport layer, dried, and then irradiated with ultraviolet rays from a high-pressure mercury lamp at a light intensity of 800 mW / cm ² for 15 seconds to give a film thickness of 4 μm.
m protective layer was formed.

[0064]

[Outside 9]

[0065]

[Outside 10]

[0066]

[Outside 11]

[0067]

[Outside 12]

(Examples 2 to 9) Sample Nos. 2, 3, 5, 6 of Table 1 were used as the binder resin for the charge transport layer.
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the polycarbonates 8, 9, 11 and 12 were used.

The prepared electrophotographic photosensitive member was heated at 23 ° C. and 30%
After being left overnight under RH, it was mounted on a modified laser beam printer LBP-NX manufactured by Canon to measure the residual potential. That is, remove the developing device and cleaner, prepare a cartridge with a potential sensor attached to the position of the developing device,
After removing the transfer roller from the main body, the potential of the surface of the photoconductor was set to V1 after the electrophotographic process for printing 5 A4 sheets in the full black image mode (entire light irradiation), and then the laser irradiation was continued. The surface potential when the primary charge was cut off and the photoconductor rotated 5 times was defined as the residual potential.

Further, 15,000 sheets of paper were passed through, and Vl and residual potential of the photoreceptor immediately after running were measured in the same manner as above.

Further, another photosensitive member prepared in the same manner as above was irradiated with light of a fluorescent lamp of illuminance 2000lux for 6 minutes, left in the dark for 2 minutes after irradiation, and then V1 was measured by the same method as described above. A photo memory is obtained by subtracting Vl of the part where the light was applied from V1 of the part where the light was not applied.

Further, an image in which a black line having a width of 1 dot was repeated at intervals of 2 dots was formed using the photoconductor evaluated for the photo memory, and the obtained image was visually evaluated.

[0073]

Comparative Examples 1 to 6 Sample Nos. 4, 7, 10 and 1 in Table 1 were used as binder resins for the charge transport layer.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the polycarbonates 3, 14, and 15 were used. Table 3 shows the results.

[0075]

Examples 10 to 18 Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Examples 1 to 9 except that the acrylic monomer exemplified compound No. 22 was used as the binder resin for the protective layer.

The results are shown in Table 4.

[0078]

(Examples 19 and 20) Example 1 was repeated except that the charge transporting material having the following structure was used.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Steps 1 and 2. The results are shown in Table 5.

[0080]

[Outside 13]

[0081]

(Comparative Examples 7 and 8) Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Comparative Examples 1 and 2, except that the charge transporting materials having the following structures were used. Table 6 shows the results.

[0083]

[Outside 14]

[0084]

(Examples 21 to 23) Polycarbonates of sample number 2 and sample number 13 of Table 1 were used as binder resins for the charge transport layer in a weight ratio of 7%, respectively.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 2 except that 0/30, 60/40 and 50/50 were used. The results are shown in Table 7.

[0086]

(Comparative Examples 9 and 10) Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Example 1 and Comparative Example 1 except that the thickness of the charge transport layer was 24 μm and no protective layer was applied. . Table 8 shows the results.

[0088]

[0089]

As described above, according to the electrophotographic photoreceptor of the present invention, the process cartridge and the electrophotographic apparatus having the electrophotographic photoreceptor, the residual potential is maintained while maintaining excellent mechanical durability due to the protective layer. Can be reduced, image deterioration due to a rise in residual potential due to durability can be prevented, electrical sensitivity can be increased, and photo memory can be reduced.

[Brief description of 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 showing an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

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Claims (10)

[Claims] 1. An electrophotographic photoreceptor having a conductive support, a photosensitive layer on the conductive support, and a protective layer on the photosensitive layer, wherein the protective layer contains a curable resin, and the photosensitive layer comprises 17
An electrophotographic photosensitive member comprising a resin having a glass transition point of 0 ° C. or higher. 2. The electrophotographic photosensitive member according to claim 1, which has a glass transition point of 240 ° C. or lower. 3. The electrophotographic photosensitive member according to claim 1, wherein the resin having a glass transition point of 170 ° C. or higher is polycarbonate. 4. The electrophotographic photosensitive member according to claim 1, wherein the proportion of the resin having a glass transition point of 170 ° C. or higher is 50% by weight or more based on the total weight of the resin in the contained layer. . 5. The electrophotographic photosensitive member according to claim 1, wherein the curable resin contained in the protective layer is cured by irradiation with light. 6. The electrophotographic photosensitive member according to claim 1, wherein the protective layer contains a photopolymerization initiator. 7. The electrophotographic photosensitive member according to claim 1, wherein the curable resin contained in the protective layer is an acrylic resin. 8. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a charge transport layer on the charge generation layer. 9. An electrophotographic apparatus main body integrally supporting at least one means selected from the group consisting of an electrophotographic photosensitive member according to claim 1 and a charging means, a developing means and a cleaning means. Process cartridge characterized by being removable. 10. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposing unit, a developing unit and a transferring unit.