JP2003043711A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor, a process cartridge and an electrophotographic device having high durability and electric characteristics. SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer containing a charge generating substance and a charge transfer substance on a supporting body, the surface layer of the photoreceptor contains a polymer of monomers having specified structures with polymerizable groups and fine particles having the volume average particle size in a specified range.

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. More specifically, the surface layer contains a monomer having a specific structure and fine particles having a specific particle size. The present invention relates to an electrophotographic photosensitive member containing the electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In recent years, organic photoconductive substances have been widely used as materials used for electrophotographic photoreceptors because they have advantages such as pollution-free property and high productivity. These electrophotographic photoreceptors are often used as function-separated photoreceptors in which a charge generation layer and a charge transport layer are laminated in order to satisfy both electrical and mechanical properties.

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.

In particular, the surface layer of a photoreceptor which is repeatedly used is directly subjected to various electric and mechanical external forces such as charging, exposure, toner development, transfer to paper and cleaning, and therefore has durability against them. Required.
Specifically, lowering of sensitivity, lowering of charging ability and increase of residual potential, and further durability against surface abrasion and scratches are required. In addition, excellent transferability of the toner image and cleaning of the residual toner after transfer are required,
For that purpose, it is necessary that the surface energy is small and the slipperiness is high, and it is desired that the performance is not deteriorated even when it is repeatedly used.

However, the surface layer of the electrophotographic photosensitive member using the organic photoconductive material is generally a thin and flexible resin layer, which is insufficient for obtaining sufficient durability.

The surface layer of an electrophotographic photoreceptor using an organic photoconductive material is generally a thin resin layer, and the characteristics of the resin are very important. In recent years, acrylic resins, polycarbonate resins, and the like have been put into practical use as resins that satisfy the above-described various characteristics to some extent. However, not all of the above-mentioned characteristics are satisfied by these resins, and it is difficult to say that the hardness of the resin is sufficiently high, particularly in order to further improve durability. Even when these resins are used as the resin for the surface layer, the surface layer may be worn or scratched with repeated use. In addition, due to the recent demand for higher sensitivity, a relatively large amount of low molecular weight components such as charge transport substances are often added, and a resin having even higher durability is desired.

As a means for solving these problems, use of a curable resin as a resin for a charge transport layer is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-127652. That is, using a curable resin, the charge transport layer is cured,
Crosslinking increases the film strength, improves wear resistance during repeated use, and makes it possible to achieve higher durability, but although using a curable resin improves wear resistance, On the other hand, there is a problem that scratches are relatively conspicuous due to the lack of abrasion, and the scratch resistance is lowered.
In addition, if the relative permittivity of the thermosetting monomer is high, or if the amount of unreacted polymerizable groups remaining is large, charge retention occurs,
Photo memory is likely to occur. Furthermore, the potential characteristic of the electrophotographic photosensitive member is also deteriorated. Therefore, in order to solve these problems, with respect to scratch resistance, it is proposed to add fine particles capable of absorbing external impact such as toner, roller, and paper dust, for example, fluorine atom-containing resin fine particles and inorganic fine particles. ing. Regarding photo memories, development of thermosetting monomers with low relative permittivity or development of highly reactive polymerizable groups has been carried out. However, none of these can sufficiently satisfy these problems, and although the addition of fine particles improves the wear resistance, the scratch resistance is still insufficient.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus which have good durability and electric characteristics.

[0009]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a support, wherein the surface layer of the electrophotographic photosensitive member is polymerizable. A polymer of a monomer having a structure represented by the formula (1) and having a volume average particle diameter of 0.08
An electrophotographic photosensitive member, characterized in that it contains at least one of organic fine particles and inorganic fine particles having a size in the range of from μm to 0.5 μm.

[0010]

[Outside 9]

The structure represented by the formula (1) is an acyclic structure, and R ¹ and R ² are each an optionally substituted alkylene group, a group having an ether bond in the alkylene group, a cycloalkylene group or an arylene group. Represents a group selected from the group consisting of W ¹ and W ² each represents a group having a structure represented by the following formula (2) or a group having a structure represented by the following formula (3). a is an integer of 1 or more and 10 or less. a
When is 2 or more, R ² may be different from each other.

[0012]

[Outside 10]

[0013]

[Outside 11]

In the formula (2), X represents a single bond or -O-. R ³ represents a hydrogen atom or a methyl group, and b represents 0 or 1. However, when b = 0, R ³ represents a methyl group.

In the formula (3), R ⁴ and R ⁵ each represent a group selected from the group consisting of an optionally substituted alkylene group, a cycloalkylene group and an arylene group, and the substituent of R ⁴ is represented by the above formula ( 3) A group selected from the group consisting of a group having a structure represented by 3), a hydrogen atom, an alkyl group and an aryl group. Y is a group having a structure represented by the above formula (2). c is an integer of 0 or more and 9 or less. However, a + c is 1 or more and 10 or less. When c is 2 or more, R ⁵ may be different from each other.

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

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The feature of the monomer used in the present invention is that it has a fumaric acid ester unit in the central skeleton and a polymerizable group at the end at the same time, so that it has excellent polymerizability, and the polymerization initiation reaction is a reaction with oxygen. That is. Therefore, it is important that oxygen be present during the polymerization reaction, and it is preferable that the amount of oxygen is large.

Then, as a result of studying a method of taking in more oxygen during the polymerization reaction, it became clear that it is preferable to contain fine particles. Polymerization proceeds even without containing fine particles, but in order to form a surface layer having more excellent durability, the addition of fine particles has advantages such as slipperiness imparting, hardness imparting, and reactivity improving. It is preferable to use it effectively.

It is a well-known fact that the addition of fine particles gives slipperiness and hardness, but it is presumed as follows regarding the improvement of reactivity. That is, the oxygen incorporated in the fine particles by containing the fine particles positively promotes the polymerization, thereby increasing the entanglement density of the polymer, and further, at the fine particle-polymer interface which is the original function of the fine particles. It is speculated that the more effective friction of the above absorbs external shock.

Actually, by comparing the difference in the polymerization rate of the monomer with or without the fine particles by infrared absorption spectrum, it has been confirmed that the inclusion of the fine particles has a high polymerization rate.

Further, the smaller the volume average particle diameter of the fine particles, the larger the surface area, which leads to an increase in the oxygen content, so that the volume average particle diameter of the fine particles used in the present invention is 0.
0.08 to 0.5 μm, but 0.08
It is preferable that it is not less than μm and not more than 0.3 μm. 0.0
If it is smaller than 8 μm, the amount of oxygen taken up by the fine particles is too large, and bubbles are generated on the surface of the photoconductor during the production of the drum. If it is larger than 0.5 μm, the amount of oxygen decreases, and at the same time, the polymerizability also decreases.

The dispersion average particle size (volume average particle size) and particle size distribution of fine particles are Leeds and Northr.
It was measured with a product manufactured by Up ([trade name] Microtrac UPA particle size analyzer).

The structure represented by the above formula (1) is an acyclic structure, and R ¹ and R ² are each an optionally substituted alkylene group, a group having an ether bond in the alkylene group, a cycloalkylene group or an arylene group. Among these, an alkylene group, a cycloalkylene group, and an arylene group are preferable among them because not only the reactivity is improved but also excellent electrophotographic characteristics are brought out.

In the above formula (1), a is an integer of 1 or more and 10 or less, but it is preferably an integer of 1 or more and 5 or less, and when it is 1, the reactivity is further improved. preferable.

When a is 2 or more, R ² may be different from each other.

In the above formula (1), W ¹ and W ² are each a group having a structure represented by the following formula (2), a group having a structure represented by the following formula (3), a hydrogen atom, and an alkyl group. , A cycloalkyl group, an aryl group, an oxyalkyl group, an oxyaryl group or a halogen group, but at least one of W ¹ and W ² is represented by the formula (3) from the viewpoint of excellent reactivity and electrophotographic characteristics. The group having a structure represented by the formula (1) is preferable, and the other substituent is preferably a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group.

[0027]

[Outside 12]

[0028]

[Outside 13]

In the above formula (2), X is a single bond or --O--.
, But more preferably —O—, R ³ represents a hydrogen atom or a methyl group, and b represents 0 or 1. However, when b is 0, R ³ represents a methyl group.

In the above formula (3), R ⁴ and R ⁵ each represent an optionally substituted alkylene group, cycloalkylene group or arylene group, and the substituent of R ⁴ has the structure represented by the above formula (3). A group, a hydrogen atom, an alkyl group or an aryl group is shown, and the above formula (3) or an optionally substituted alkyl group is preferable. In addition, the substituent of the alkyl group may be a group having a structure represented by the above formula (3), and it is more preferable that the number of the reactive substituents is in one molecule, and the combination with the fine particles significantly improves the film strength. . Y is a group having a structure represented by the above formula (2). c is an integer of 0 or more and 9 or less, but a positive integer of 0 or more and 5 is preferable because the reactivity is further improved. However, a + c is 0
The above is 10 or less.

When c is 2 or more, R ⁵ may be different from each other.

Further, the monomer having the structure represented by the above formula (1) is, for example, the structure represented by the above formula (2) like the monomer having the structure represented by the following formulas (9) and (10). Having 3 or more groups having a group represented by the formula or having a structure represented by the above formula (3) enhances reactivity with oxygen due to an increase in the number of reactive groups, and stabilizes the reactive species after reaction with oxygen. It is also preferred because it has high properties and good polymerizability is obtained.

[0033]

[Outside 14]

[0034]

[Outside 15]

A in the above formulas (9) and (10) is as shown in the above formula (9).

[Outside 16]

Is shown.

R ⁸ and R ⁹ are R ¹ in the above formula (1),
It is the same as R ² and R ¹⁰ represents a group having 1 to 3 carbon atoms which may have a substituent.

Further, the group having the structure represented by the above formula (2) is a group having the structure represented by the following formula (4), which has high reactivity with oxygen and has a high reactivity with oxygen. The stability of the reactive species is high and good polymerizability is obtained, which is preferable.

[0039]

[Outside 17]

The group having the structure represented by the above formula (3) is a group having the structure represented by the following formula (5), which has a high reactivity with oxygen, and has a high reactivity with oxygen. The stability of the reactive species is high and good polymerizability is obtained, which is preferable.

[0041]

[Outside 18]

In the above formula (5), R ⁶ and R ⁷ each represent a group selected from the group consisting of an optionally substituted alkylene group, a cycloalkylene group and an arylene group, and R 6
The substituent of ⁶ is a group having a structure represented by the above formula (3),
A group selected from the group consisting of a hydrogen atom, an alkyl group and an aryl group is shown.

Further, R ¹ and R ^{2 in} the above formula (1) and R ^{5 in the} above formula (3) have a structure represented by the following formula (6) and a structure represented by the following formula (7). A group having or a group having a structure represented by the following formula (8) is preferable because the photomemory characteristics are further improved.

[0044]

[Outside 19]

[0045]

[Outside 20]

[0046]

[Outside 21]

Regarding the reason why the photo memory characteristic is further improved, one possibility is that the above formulas (7) and (8) are used.
It is mentioned that the group having the structure represented by and (9) has an action of further lowering the dielectric constant of the monomer.

Specific examples of the monomer having the structure represented by the above formula (1) are shown in Table 1, but the present invention is not limited thereto. Further, two or more kinds of monomers may be mixed.

[0049]

[Table 1]

[0050]

[Table 2]

Among these, (1-1), (1-3),
(1-5), (1-6), (1-11), (1-1
2), (1-14) and (1-15) are preferable because they enable both excellent electrical characteristics and film strength to be achieved, and further (1-5), (1-6), (1-14). ), (1-
12) and (1-15) are more preferable.

Next, a method for synthesizing the monomer used in the present invention will be described.

For example, in the case of the monomer (1-5), the fumaric acid ester can be synthesized by a known transesterification method in the presence of an alcohol having a structure represented by the following formula and a catalyst.
In this case, the alcohol is 1 to 1 with respect to one ester group.
A 0-fold molar amount is used.

[0054]

[Outside 22]

Other monomers can be synthesized in the same manner as above by using an alcohol corresponding to each monomer.

Another synthetic method is condensation of fumaric acid with ether.

The solvent used here is, for example,
Examples thereof include benzene, toluene, xylene, dimethylformamide, basic pyridines, picoline and collidine.

[0058] Also, in the case of a monomer having a _CH 3 -CH = CH- _{terminated, CH 2 = CH-CH 2} - can also be synthesized by isomerizing a compound having. This isomerization reaction uses a metal complex such as Pd, Ru, or Rh or a metal-supported catalyst at a reaction temperature of 50 ° C to 200 ° C.
Can be done at.

Considering the problem of image quality deterioration, the content of the above fine particles is 50 in terms of mass ratio with respect to the polymer of the above monomers.
% Or less is preferable.

Further, a group having a structure represented by the above formula (2) or a group having a structure represented by the above formula (3) is 3
Or more monomers having the structure represented by the formula (1), or the above formula (1) having a highly reactive polymerizable group having the structure represented by the formula (4) or (5)
When a monomer having the structure shown in is used, the amount of fine particles may be reduced to prevent deterioration of image quality. In that case, the content of the fine particles is more preferably 30% or less with respect to the polymer of the monomer.

On the other hand, in order to bring out the effect of the present invention more remarkably, the monomer having the structure represented by the above formula (1) may be a group having the structure represented by the following formula (11). In particular, in the case of a monomer having only two or less groups having relatively low reactivity with oxygen, it is preferable that the fine particles have a mass ratio of 20% or more with respect to the polymer of the monomer. .

[0062]

[Outside 23]

When the surface layer is prepared by applying the solution for the surface layer and then drying it, it is preferable that the drying temperature is 130 ° C. or higher because higher curability can be obtained, and more preferably 140 ° C. or higher and 170 ° C. or lower. More preferable.

The surface layer containing the above-mentioned fine particles is preferably thin in order to improve the image quality, and preferably has a layer structure in which a protective layer as a surface layer is provided on the photosensitive layer.

In order to maintain excellent electric characteristics, it is preferable that the protective layer contains a charge-transporting substance not only in the photosensitive layer but also in the layer structure provided with the protective layer.

In order to further increase the strength of the film, the charge transport material preferably has a polymerizable group capable of reacting with the monomer having the structure represented by the above formula (1).

Examples of the charge transporting substance having a polymerizable group capable of reacting with the monomer having the structure represented by the above formula (1) include the following charge transporting substances.

[0068]

[Outside 24]

[0069]

[Outside 25]

[0070]

[Outside 26]

[0071]

[Outside 27]

Of these, (CTM-1) and (CTM-2) are preferable because of their excellent reactivity,
Furthermore, (CTM-1) is more preferable because of its excellent solubility.

The organic fine particles used in the present invention include:
Silicone resin, polymethacrylate (PMMA),
Fine particles of polystyrene, crosslinked polystyrene, acrylic resin, styrene / acrylic resin, melamine resin, benzoguanamine / melamine resin, phenol resin, polytetrafluoroethylene, n-butyl acrylate, urea resin, polyvinylidene fluoride, urethane resin, cellulose acetate, etc. Is mentioned. Among them, the fluorine atom-containing resin fine particles are preferable because they are effective not only for providing lubricity but also for improving the reactivity of the monomer, and more preferably polytetrafluoroethylene fine particles.

If necessary, a dispersion aid may be added to stabilize the dispersion of fine particles.

The inorganic fine particles used in the present invention include:
Oxides such as silica, alumina, zinc oxide and zirconium oxide, carbon nitride, aluminum nitride, nitrides such as silicon nitride, carbides such as silicon carbide, strontium titanate,
Examples thereof include fine particles of a titanic acid compound such as barium titanate. Among them, silica fine particles and alumina fine particles are preferable because they are effective not only for improving the surface hardness but also for improving the reactivity of the monomer. It is presumed that these fine particles contain a large amount of oxygen.

The surface of the inorganic fine particles is preferably hydrophobic in order to suppress environmental fluctuations.

It is more preferable that the inorganic fine particles contain a larger amount of oxygen than the organic fine particles and the film strength is further improved.

The electric resistance value required for the fine particles varies depending on the electric resistance value required for the surface layer.
It is preferable that the 0 ⁸ Ω · cm or more. 10 ⁸ Ω · c
When it is less than m, problems tend to occur in the charge retention of the photoconductor, image quality and the like.

Further, it is necessary that the other layers are not deteriorated by the heat when the surface layer solution is applied and then dried in the process of preparing the surface layer. Further, since the photoreceptor of the present invention has high durability, it is necessary that the electrophotographic characteristics are stable for a long period of time. Therefore, it is required that not only the charge transporting material that constitutes the photosensitive layer but also the charge generating material have excellent repeating characteristics. In particular, the selection of the charge generating substance is one of the factors that greatly influence the durability stability. Therefore, it is preferable that the charge generating substance used is one that is less deteriorated by heat and has excellent durability stability.

From this point of view, as the charge generating substance, phthalocyanine pigments and azo pigments are preferable, and among them, phthalocyanine pigments are more preferable because they can maintain more stable electrophotographic characteristics. Further, among the phthalocyanine pigments, hydroxygallium phthalocyanine or oxytitanium phthalocyanine is preferable because they are particularly excellent in electrophotographic characteristics. With hydroxygallium phthalocyanine, a Bragg angle of 2θ ± 0.2 ° in CuKα X-ray diffraction of 7.5 is preferable. °, 9.9 °, 16.3
°, 18.6 °, 25.1 °, 28.3 °, and a crystalline form of hydroxygallium phthalocyanine is more preferable, and if it is oxytitanium phthalocyanine, the Bragg angle 2θ ± 0.
2 ° 9.0 °, 14.2 °, 23.9 °, 27.1 °
A crystalline form of oxytitanium phthalocyanine having a strong peak is preferred.

CuKα rays were used for the measurement of X-ray diffraction under the following conditions.

Measuring instrument used: Full automatic X-ray diffractometer MXP18 manufactured by Mac Science Co., Ltd. X-ray tube: Cu tube voltage: 50 KV tube current: 300 mA Scan method: 2θ / θ scan Scan speed: 2 deg. / Min Sampling interval: 0.020 deg. Start angle (2θ): 5 deg. Stop angle (2θ): 40 deg. Divergence slit: 0.5 deg. Scattering slit: 0.5 deg. Receiving slit: 0.3 deg. Use of Curved Monochrometer The configuration of the electrophotographic photosensitive member used in the present invention will be described below.

The electrophotographic photoreceptor of the present invention is a single-layer type in which the photosensitive layer contains the charge transporting substance and the charge generating substance in the same layer, but the function separating type in which the charge transporting layer and the charge generating layer are separated. (Laminate type) may be used, but the laminate type is preferable in terms of electrophotographic characteristics. A protective layer may be provided as the surface layer, but at least the surface layer of the electrophotographic photosensitive member may contain the monomer having the reactive site represented by the formula (1) and the fine particles.

The support used in the present invention may be any support as long as it has conductivity. For example, a metal such as aluminum, copper, chromium, nickel, zinc or stainless is molded into a drum or sheet. Thing, metal foil such as aluminum or copper laminated on plastic film, aluminum, indium oxide,
Examples thereof include those obtained by vapor-depositing tin oxide or the like on a plastic film, and surface treatment may be performed if necessary.

When the image input such as a laser beam printer (LBP) is laser light, interference fringes due to scattering are prevented,
Alternatively, a conductive layer may be provided for the purpose of covering scratches on the base. This can be formed by dispersing conductive fine particles such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is 5 to 40 μm, preferably 10 to 30 μm.

Further, an intermediate layer having an adhesive function may be further provided thereon. Examples of materials for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in a suitable solvent and applied. The thickness of the intermediate layer is 0.05-5μ
m, preferably 0.3 to 1 μm.

A charge generation layer is formed on the support, the conductive layer or the intermediate layer when the photosensitive layer is a function-separated type. Examples of the charge generating substance used in the present invention include phthalocyanine, trisazo, disazo and monoazo pigments. For the charge generation layer, a method such as a homogenizer, ultrasonic dispersion, ball mill, vibrating ball mill, sand mill, attritor, roll mill and liquid collision type high speed disperser is used together with a binder resin and a solvent in an amount of 0.3 to 4 times the amount of the charge generation material. It is formed by thoroughly dispersing with, and applying and drying the dispersion liquid. The thickness of the charge generation layer is 5 μm or less, preferably 0.1
˜2 μm is suitable.

Then, when the charge transport layer is a surface layer,
The above-mentioned monomer and fine particles are dissolved in a solvent and dispersed using a dispersion method such as ultrasonic dispersion, a ball mill, a vibrating ball mill, a sand mill, an attritor, a roll mill or a liquid collision type high speed disperser. A liquid collision type high speed disperser is preferable. Further, it is formed by applying and drying a paint in which the dispersed liquid and the charge transport substance are dissolved in a solvent. The charge transport material is combined with 0.5 to 2 times the amount of binder resin, and the film thickness of the charge transport layer is 5 to 40 μm, preferably 15 to 30 μm.

When the charge transport layer is not the surface layer, a thermoplastic resin may be used instead of the polymer of the above monomers. The thermoplastic resin here is a resin generally used in the field of electrophotographic photoreceptors, and examples thereof include polycarbonate, polyarylate, polyamide, polysulfone, phenoxy, and epoxy resin, but are not limited thereto. is not.

When the photosensitive layer is a single layer, it can be formed by coating a solution in which the charge generating substance and the charge transporting substance are dispersed and dissolved in the above-mentioned monomer and drying. The dispersion method is selected from the methods for dispersing the charge generating substance. The thickness of the single layer is 5 to 40 μm, preferably 15 to 30 μm.

Next, when there is a layer for protecting the photosensitive layer, that is, a protective layer, the monomer of the present invention and fine particles are dissolved in a solvent, dispersed and coated. In order to bring out excellent electrophotographic characteristics, it is preferable to use a charge transport material or a conductive metal oxide that controls electric resistance. When using the charge transport material, it is more preferable to use one having a reactive group capable of polymerizing with the monomer according to the present invention.

The surface layer can be formed by a method of curing with heat, light or an electron beam, and may contain a polymerization initiator or an antioxidant if necessary.

Solvents used in the electrophotographic photoreceptor manufacturing process include chlorobenzene, tetrahydrofuran,
1,4-dioxane, toluene, xylene, etc. may be used, and they may be used alone or in combination of a plurality of solvents.

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 rotationally driven around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. In the course of rotation, the photosensitive member 1 is uniformly charged on its peripheral surface with a predetermined positive or negative potential by the primary charging unit 3, and then is exposed from an exposing unit (not shown) such as slit exposure or laser beam scanning exposure. Receive light 4. 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 transferred to the transfer material 7 which is fed between the photosensitive member 1 and the transfer unit 6 in synchronization with the rotation of the photosensitive member 1 from a sheet feeding unit (not shown). The images are sequentially transferred by the transfer means 6.

The transfer material 7 having undergone the image transfer is separated from the surface of the photoconductor and introduced into the image fixing means 8 to undergo the image fixing, so that it is printed out as a copy out of the apparatus.

The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning means 9 after removal of the transfer residual toner, and further the pre-exposure light 1 from the pre-exposure means (not shown).
After being neutralized by 0, it is repeatedly used for image formation. 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, a process in which 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 which can be attached to and detached from the apparatus main body by using a guide unit such as a rail 12 of the apparatus main body. It can be the cartridge 11.

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

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 also be widely used in electrophotographic application fields such as RT printers, LED printers, liquid crystal printers, and laser plate making.

Hereinafter, the present invention will be described in more detail with reference to Examples. In addition, "part" in an Example shows a mass part.

[0103]

[Example 1] [Example 1] Diameter 30 mm, length 357.5
mm aluminum cylinder as a support, and
A coating composed of the following materials is applied on a support by a dip coating method, and heat-cured at 140 ° C. for 30 minutes to give 15 μm.
The conductive layer of was formed.

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 thereon by a dip coating method, and at 100 ° C. It was dried for 10 minutes to form a 0.5 μm intermediate layer.

Next, in the X-ray diffraction of CuKα, Bragg angles 2θ ± 0.2 ° of 7.5 °, 9.9 °, 16.3.
Crystalline hydroxygallium phthalocyanine 4 having strong peaks at °, 18.6 °, 25.1 °, and 28.3 °
To 95 parts of cyclohexanone butyral resin (degree of butyralization 63 mol%, weight average molecular weight 100,000)
Add 2 parts to the melted solution, and use a sand mill using glass beads with a diameter of 1 mm for 20 minutes in an atmosphere at a temperature of 21 ± 3 ° C.
Time dispersed. Then, 60 parts of ethyl acetate was added to prepare a dispersion liquid for the charge generation layer.

Next, a dispersion liquid used in the charge transport layer was prepared.

30 parts of the above monomer (1-1), 5 parts of polytetrafluoroethylene fine particles (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.), and a comb-type fluorine-based graft polymer (Aron) as a dispersion aid. GF-300: manufactured by Toagosei Kagaku Co., Ltd. (0.6 part) was mixed with 70 parts of monochlorobenzene and stirred, and then dispersed by a liquid collision type high-speed disperser. To 100 parts of this dispersion was added 70 parts of monochlorobenzene and 60 parts of dichloromethane, and a charge transport material (CT
M-1) 25 parts was added and dissolved to obtain a charge transport layer coating material,
After dip coating on the charge generation layer, it was dried at 150 ° C. for 60 minutes to provide a charge transport layer having a film thickness of 22 μm to obtain an electrophotographic photoreceptor.

Next, the evaluation will be described.

(Evaluation of initial characteristics) Evaluator GP-40 (plain paper copying machine) (manufactured by Canon Inc.) Charging method: roller contact charging means with AC voltage superimposed (AC / DC roller contact charging means) Process speed : 210 mm / sec Laser light amount: 0.35 μJ / cm ² Cleaning blade: The linear pressure to the photoconductor was set to 1.3 times the usual value.
The dark portion potential Vd, the light portion potential Vl, and the residual potential Vr were measured under a normal temperature and normal humidity environment (N / N) at 3 ° C. and a humidity of 50% RH. Regarding Vd, the amount of dark attenuation was evaluated to make it easier to evaluate the charging ability. That is, the applied voltage and the rotation of the drum were cut off immediately after measuring Vd, and Vd was evaluated after standing for 10 seconds. In addition, in order to measure the electrophotographic characteristics of the photoconductor, the measurement was performed using a potential measuring jig having a probe attached at the developing position.

The smaller the absolute value of dark decay, the better the charging ability, and the smaller the light potentials Vl and Vr, the better the characteristics.

(Durability Evaluation) 4 under normal temperature and normal humidity (N / N)
A 10,000 sheet passing durability test was performed, Vl after 40,000 sheets was measured, and the amount of Vl potential fluctuation at the initial stage and after durability was evaluated. The Vl potential fluctuation amount was calculated according to the following.

Vl potential fluctuation amount = Vl potential after paper running endurance-initial Vl potential Regarding the scratches appearing on the image, image defects due to scratches along the circumferential direction of the photosensitive drum may be seen.

Regarding the depth of the scratch, a surface roughness measuring machine (Surfcoder SE-3300 manufactured by Kosaka Laboratory Ltd.) was used, and the cutoff value was 0.8 mm, the reference length was 0.8 mm, and the evaluation length was 8 mm. The measurement was carried out under the conditions of 0.0 mm and Gaussian filter.

Regarding the wear resistance, an eddy current type film thickness meter (Permascope type E111) manufactured by Fischer Co. was used for measuring the wear amount.

The durable paper feed image is A4, and the printing rate is 4%.
And a grid pattern. Also, the sequence is print 1
The intermittent mode is used in which the sheet is stopped once for each sheet. If the toner runs out, it is replenished.

(Evaluation of Photo-Memory) A part of the electrophotographic photosensitive member after endurance was exposed to light of a white fluorescent lamp of 3000 lux for 20 minutes and allowed to stand for 4 minutes, and then the light-area potential was measured. The amount of change was measured and the amount of change was used as the photo memory value. The amount of change is 0 to 30V
The case is marked with ⊚, the case of 31 to 60V is marked with ◯, the case of 61 to 90V is marked with Δ, and the case of 91 to 120V is marked with x.

Comparative Example 1 Example 1 is the same as Example 1 except that the fine particles and the dispersion aid in the charge transport layer are removed.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in.

Specifically, 150 parts of monochlorobenzene and 60 parts of dichloromethane were added to 40 parts of the monomer (1-1), and 33 parts of the charge transport material (CTM-1) was further added to obtain a coating material for the charge transport layer.

[Examples 2 to 13] In Example 1, instead of the monomer (1-1) and the polytetrafluoroethylene fine particles shown in Table 2, the amounts of the fine particles are shown in Table 2. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except for the above.

Fine particles other than the polytetrafluoroethylene-hexafluoropropylene resin could be dispersed without a dispersing aid.

The fine particles are as follows.

Polytetrafluoroethylene-hexafluoropropylene fine particles: [trade name] NEOFLON, Daikin Industries, Ltd.
Made of acrylic rubber fine particles: [trade name] Staphyroid IM,
Takeda Pharmaceutical Co., Ltd. Silicone resin fine particles: [trade name] XC-99-50
1, GE Toshiba Silicone Co., Ltd. hydrophobized silica fine particles: [trade name] X-120, Shin-Etsu Chemical Co., Ltd. alumina fine particles: [trade name] LS-235, manufactured by Nippon Light Metal Co., Ltd. [Example 14] ] In Example 1, the monomer (1-1)
Instead of the monomer (1-14), a charge transport material (CTM
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the charge transporting material (CTM-5) was used instead of -1) and the amount of fine particles was changed to 13 parts.

[0123]

[Outside 28]

[Comparative Examples 2 to 5] Examples 8, 10, 13 and
14 is the same as Examples 8, 10, 13, and 14 except that the fine particles in the charge transport layer were removed.

Example 15 In the electrophotographic photosensitive member of Example 1, the charge transport layer was changed as follows, and a protective layer was further provided thereon.

Specifically, 30 parts of a polycarbonate resin ([trade name] Iupilon Z400, manufactured by Mitsubishi Gas Chemical Co., Inc.) as a charge transport layer and a charge transport material (CTM-1) 2
7 parts was added to 130 parts of monochlorobenzene and 80 parts of dichloromethane to be dissolved to prepare a charge transport layer coating material, which was applied by dipping and dried at 120 ° C. for 60 minutes to provide a charge transport layer having a film thickness of 17 μm.

Next, as a dispersion of the protective layer, 13 parts of the monomer (1-15) and polytetrafluoroethylene fine particles ([trade name] Lubron L-2, manufactured by Daikin Industries, Ltd.)
After mixing 6.5 parts and 0.5 part of a comb-type fluorine-based graft polymer ([trade name] Aron GF-300, manufactured by Toa Gosei Kagaku Co., Ltd.) as a dispersion aid with 100 parts of monochlorobenzene and stirring, Dispersion was performed in the same manner as in Example 1. 25 parts of this dispersion and charge transport material (CTM-1) 2.
0 part was mixed with 20 parts of monochlorobenzene and 10 parts of dichloromethane and dissolved to obtain a coating material for the surface protective layer. This coating composition was spray coated on the charge transport layer and dried at 150 ° C. for 60 minutes to form a protective layer of 4.0 μm, and an electrophotographic photoreceptor was prepared and evaluated.

[Examples 16 and 17] Example 15 except that the polytetrafluoroethylene fine particles in Example 15 were replaced with the fine particles shown in Table 2 and the amount of the fine particles was changed as shown in Table 2. An electrophotographic photoreceptor is prepared in the same manner as
evaluated.

[Comparative Examples 6 and 7] With respect to Comparative Example 6, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the monomer (1-1) in Example 15 was replaced with the following comparative monomer 1. And evaluated.

[0130]

[Outside 29]

Regarding Comparative Example 7, in Comparative Example 6,
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Comparative Example 6 except that the fine particles in the charge transport layer were removed.

Specifically, 13 parts of the above-mentioned comparative monomer 1 was used.
Part, and 2-methylthioxanthone as a photopolymerization initiator.
07 parts, polytetrafluoroethylene fine particles (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) 3.3 parts, a comb-type fluorine-based graft polymer (Aron GF- as a dispersion aid)
300: Toa Gosei Kagaku Co., Ltd. 0.5 part and 100 parts of methyl cellosolve were mixed and stirred, and then dispersed in the same manner as in Example 1. 25 parts of this dispersion and 2.0 parts of the charge transport substance (1) were mixed and dissolved in 30 parts of monochlorobenzene to obtain a coating material for the surface protective layer. This coating material was spray-coated on the photosensitive layer, dried at 150 ° C. for 20 minutes, and then photocured with a high-pressure mercury lamp at a light intensity of 8 mW / cm ² for 15 seconds to form a protective layer. The thickness of the protective layer was 4 μm. For Comparative Example 7, the fine particles and the dispersion aid were removed.

[Examples 18 and 19, Comparative Examples 8 and 9] In Example 17, the volume average particle diameter of the fine particles of the protective layer is shown in Table 2.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 17, except that the procedure was as shown in.

[Comparative Examples 10 and 11] In Comparative Example 10, an electrophotographic photosensitive member was prepared in the same manner as in Example 17, except that the monomer (1-15) in Example 17 was replaced with the following comparative monomer 2. And evaluated.

[0135]

[Outside 30]

Regarding Comparative Example 11, Comparative Example 10 was used except that the fine particles in the charge transport layer were removed from Comparative Example 10.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in.

Table 2 below shows a list of the monomers and fine particles used in Examples 1 to 19 and Comparative Examples 1 to 11, and Table 3 shows the evaluation results of Examples 1 to 19 and Comparative Examples 1 to 11.

[0138]

[Table 3]

[0139]

[Table 4]

[0140]

[Table 5]

[0141]

[Table 6]

From Table 3, the following can be summarized.

Comparing Example 1 with Comparative Example 1, it can be seen that Example 1 containing fine particles of polytetrafluoroethylene has good initial characteristics, photomemory, variation in endurance potential, and film strength. Comparative Example 1 has a possibility that the characteristics are poor, the abrasion resistance is more than doubled, and the polymerization rate is low.

When Example 2 and Example 3 are compared, when the same monomer is used, the scratch depth of the film is 50% in Example 2 compared with Example 3 containing 17% of fine particles. It can be seen that good results are obtained in terms of.

When Example 5 and Example 6 are compared, Example 6 using hydrophobized silica fine particles is more preferable than Example 5 using polytetrafluoroethylene fine particles when the same monomer is used. It can be seen that good results are obtained in terms of the amount of wear.

Comparing Example 8 with Comparative Example 2, it can be seen that in Example 8 using fine particles, both electrical characteristics and film strength are compatible, but Comparative Example 2 is not compatible.

Comparing Example 14 with Comparative Example 5, the electrical characteristics and the electrical characteristics of Example 14 using the polytetrafluoroethylene fine particles were higher than those of Comparative Example 5 not using the polytetrafluoroethylene fine particles. It can be seen that both the wear amount and the scratch resistance are good.

Examples 16 and 17 are examples of electrophotographic photoreceptors having a layer structure in which a layer for protecting the photosensitive layer, that is, a protective layer is provided. The content of fine particles is different in these two examples,
It can be seen that both examples have good wear resistance and scratch resistance.

Comparative Examples 6 and 7 are examples for observing the effect of fine particles using a comparative monomer. It can be seen that the difference in film strength is small with / without fine particles. on the other hand,
Since the monomer according to the present invention contains the fine particles, the durability is approximately doubled. Therefore, it can be said that the addition of the fine particles further improves the film strength.

From Comparative Examples 8 and 9, it can be seen that the scratch resistance is deteriorated when the volume average particle size of the fine particles is below the lower limit or above the upper limit specified in the present invention.

From Comparative Examples 10 and 11, it is understood that when a monomer whose central skeleton is not a fumaric acid ester unit is used as a comparative monomer, electrophotographic properties and durability are significantly reduced.

Example 20 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the support was replaced by an aluminum cylinder having a diameter of 30 mm and a length of 260.5 mm. In, the evaluation was performed in the same manner as in Example 1 except for the following points.・ Evaluator LBP-SX (laser beam printer) (manufactured by Canon Inc.) Charging method: Corona charging process speed: 47 mm / sec Cleaning blade: Linear pressure to the photoreceptor is set to 1.3 times the normal dark area potential Vd: -600 Laser light amount: set to a light amount such that the bright portion potential Vl becomes -150 V when irradiated with a laser beam having a wavelength of 802 nm. The electrophotographic characteristics were measured using a potential measuring jig with a probe attached at the developing position.

The number of durable sheets was changed to 5,000.

Comparative Example 12 An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 1 except that the support was replaced by an aluminum cylinder having a diameter of 30 mm and a length of 260.5 mm. It evaluated similarly to.

The amount of laser light is the amount of light such that the bright portion potential Vl of the electrophotographic photosensitive member of Example 20 becomes −150 V when the laser beam of wavelength 802 nm is irradiated, that is, the same amount of light as in Example 20. is there.

Example 21 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the support was replaced by an aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm. In, the evaluation was performed in the same manner as in Example 1 except for the following points. Evaluator NP-6030 (plain paper copier) (Canon Co., Ltd.) Charging method: DC voltage application (DC charging) Process speed: 200 (mm / sec) Cleaning blade: Normal linear pressure to the photoreceptor is 1 Set to 5 times dark part potential Vd: -600 Laser light amount: set to light amount so that bright part potential Vl becomes -200 V. Electrophotographic characteristics were measured using a potential measuring jig with a probe attached at the developing position.

The number of durable sheets was changed to 20,000.

Comparative Example 13 An electrophotographic photosensitive member was prepared in the same manner as in Comparative Example 1 except that the support was replaced by an aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm. It evaluated similarly to.

The laser light quantity is the light quantity at which the bright portion potential Vl of the electrophotographic photosensitive member of the twenty-first embodiment becomes -200 V, that is, the same light quantity as that of the twenty-first embodiment.

Table 4 below shows the evaluation results of Examples 20 and 21 and Comparative Examples 12 and 13.

[0161]

[Table 7]

Image defects were found in Comparative Examples 12 and 13, but no image defects were found in Examples 20 and 21.
Therefore, the electrophotographic photosensitive member of the present invention can obtain sufficient electrophotographic characteristics even when it is used in an electrophotographic apparatus having a different charging method.

[0163]

From the above results, the electrophotographic photosensitive member of the present invention having a specific surface layer has good mechanical strength, particularly good scratch resistance, and good electrophotographic characteristics. It can be seen that the photo memory characteristics are good and the repeating characteristics are also excellent.

[Brief description of drawings]

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

[Explanation of symbols]

1 Electrophotographic photoreceptor 2 axes 3 charging means 4 exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge container 12 guidance means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 5/06 371 G03G 5/06 371 5/07 105 5/07 105 5/147 502 5/147 502 503 503 504 504 (72) Inventor Hideki Anayama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Co., Ltd. (reference) 2H068 AA03 AA04 AA06 AA13 AA14 AA20 AA37 BA39 BB05 BB31 BB44 CA06 CA33 EA19 FA27

Claims (24)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a support, and the surface layer of the electrophotographic photosensitive member is represented by formula (1) having a polymerizable group. An electrophotographic photoreceptor comprising a polymer of a monomer having a structure, and at least one of organic fine particles and inorganic fine particles having a volume average particle diameter of 0.08 μm or more and 0.5 μm or less. [Outer 1] (The structure represented by the formula (1) is an acyclic structure, and R ¹ ,
R ² represents a group selected from the group consisting of an alkylene group which may be substituted, a group having an ether bond in the alkylene group, a cycloalkylene group and an arylene group,
W ¹ and W ² each represent a group having a structure represented by the following formula (2) or a group having a structure represented by the following formula (3). a is an integer of 1 or more and 10 or less. When a is 2 or more, R ² may be different from each other. [Outside 2] [Outside 3] In formula (2), X represents a single bond or -O-. R ³ represents a hydrogen atom or a methyl group, and b represents 0 or 1.
However, when b = 0, R ³ represents a methyl group. Formula (3)
Wherein R ⁴ and R ⁵ each represent a group selected from the group consisting of an optionally substituted alkylene group, a cycloalkylene group and an arylene group, and the substituent of R ⁴ is represented by the above formula (3).
Represents a group having a structure represented by, a hydrogen atom, an alkyl group and an aryl group. Y is a group having a structure represented by the above formula (2). c is 0
It is an integer of not less than 9 and not more than 9. However, a + c is 1 or more and 10
It is the following. When c is 2 or more, R ⁵ may be different from each other. ) 2. The method according to claim 1, wherein the monomer represented by the formula (1) has three or more groups having the structure represented by the formula (2) or groups having the structure represented by the formula (3). The electrophotographic photosensitive member described. 3. The group having a structure represented by the formula (2) is a group having a structure represented by the following formula (4), and the group having a structure represented by the formula (3) is a group represented by the following formula (5): 3. The electrophotographic photosensitive member according to claim 1, which is a group having a structure represented by [Outside 4] [Outside 5] (In the formula (5), R ⁶ and R ⁷ each represent a group selected from the group consisting of an optionally substituted alkylene group, a cycloalkylene group and an arylene group, and the substituent of R ⁶ is the above formula (3). Represents a group having a structure represented by, a hydrogen atom, an alkyl group, and an aryl group.) 4. R ¹ and R ^{2 of} the formula (1), R ^{5 of the} formula (3) have a structure represented by the following formula (6), and a structure represented by the following formula (7). The electrophotographic photoreceptor according to claim 1, which is a group selected from the group consisting of a group and a group having a structure represented by the following formula (8). [Outside 6] [Outside 7] [Outside 8] 5. The electrophotographic photosensitive member according to claim 1, wherein the fine particles have a mass ratio of 50% or less with respect to the polymer of the monomer. 6. The electrophotographic photosensitive member according to claim 1, wherein the fine particles have a mass ratio of 30% or less with respect to the polymer of the monomer. 7. The electrophotographic photosensitive member according to claim 1, wherein the fine particles have a mass ratio of 20% or more with respect to the polymer of the monomer. 8. The electrophotographic photosensitive member according to claim 1, wherein a drying temperature for producing a surface layer containing the polymer of the monomer and the fine particles is 130 ° C. or higher. 9. The electrophotographic photoreceptor according to claim 1, wherein the surface layer containing the polymer of the monomer and the fine particles is a protective layer. 10. The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains a charge transport substance. 11. The electrophotographic photosensitive member according to claim 10, wherein the charge transport material has a polymerizable group capable of reacting with the monomer. 12. The volume average particle diameter of the fine particles is 0.08.
The electrophotographic photosensitive member according to any one of claims 1 to 11, wherein the electrophotographic photosensitive member has a size of from µm to 0.3 µm. 13. The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains organic fine particles. 14. The electrophotographic photosensitive member according to claim 13, wherein the organic fine particles are fluorine atom-containing resin fine particles. 15. The electrophotographic photosensitive member according to claim 14, wherein the fluorine atom-containing resin particles are polytetrafluoroethylene. 16. The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains inorganic fine particles. 17. The electrophotographic photosensitive member according to claim 16, wherein the inorganic fine particles are hydrophobized silica fine particles or alumina fine particles. 18. The electrophotographic photosensitive member according to claim 1, wherein the charge generating substance is a phthalocyanine pigment. 19. The electrophotographic photosensitive member according to claim 18, wherein the phthalocyanine pigment is hydroxygallium phthalocyanine. 20. The Bragg angle 2θ ± 0. In the X-ray diffraction of CuKα, wherein the hydroxygallium phthalocyanine is
2 ° 7.5 °, 9.9 °, 16.3 °, 18.6 °,
The electrophotographic photosensitive member according to claim 19, which is a crystalline form of hydroxygallium phthalocyanine having strong peaks at 25.1 ° and 28.3 °. 21. The electrophotographic photosensitive member according to claim 18, wherein the phthalocyanine pigment is oxytitanium phthalocyanine. 22. The Bragg angle 2θ ± 0.2 in X-ray diffraction of CuKα, wherein the oxytitanium phthalocyanine is
The electrophotographic photosensitive member according to claim 21, which is a crystalline form of oxytitanium phthalocyanine having strong peaks at 9.0 °, 14.2 °, 23.9 °, and 27.1 °. 23. An electrophotographic photoreceptor according to any one of claims 1 to 22 and at least one means selected from the group consisting of charging means, exposure means, developing means and cleaning means are integrally supported. , A process cartridge which is detachable from the main body of the electrophotographic apparatus. 24. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposing unit, a developing unit and a cleaning unit.