JP2003098705A - Electrophotographic photoreceptor, electrophotographic method using the electrophotographic photoreceptor, electrophotographic device and process cartridge for electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which can form an image of high picture quality having no image defect and which has excellent durability and to provide an electrophotographic method, an electrophotographic device and a process cartridge for the electrophotographic device by using the electrophotographic photoreceptor which can form an image of high picture quality having no image defect and which has excellent durability. SOLUTION: In the electrophotographic photoreceptor having at least an intermediate layer and a photosensitive layer on a conductive supporting body, the intermediate layer contains at least a binder resin and two kinds of titanium oxides having >=99.0% purity and different average particle sizes. The average particle size (D1 ) of the one titanium oxide (T1 ) and the average particle size (D2 ) of the other titanium oxide (T2 ) satisfy the relation of 1/5<D2 /D1 <=1/2.

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 which gives a high-quality image free from image defects and has excellent durability. Further, the present invention relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus, which uses an electrophotographic photosensitive member having an excellent durability, which gives a high-quality image without image defects.

[0002]

2. Description of the Related Art Conventionally, as a photoconductive material for an electrophotographic photosensitive member, an organic photoconductive material having superiority in sensitivity, thermal stability, toxicity, etc. to inorganic materials such as Se, CdS, ZnO has been used. The development of electrophotographic photoconductors has been actively carried out, and many electrophotographic photoconductors using organic photoconductive materials have been installed in many copying machines and printers.

Generally, in an image forming apparatus such as a printer, a copying machine or a facsimile, an image is formed by a series of processes of charging-exposure-developing-transfer. Therefore, an apparatus for performing such image formation includes at least a charging device, an image exposure device, a developing device (in particular, a reversal developing device), a transfer device and an electrophotographic photoreceptor. However, in the image forming apparatus having such a configuration, an abnormal image is likely to occur during long-term continuous use.

[0004] In particular, background stains and black spots are problems as abnormal images during reversal development. As one of the techniques for improving the main characteristics of an organic photoreceptor, after providing an intermediate layer on a conductive support. It has been proposed to provide a photosensitive layer. Known examples of this are those in which a resin layer is provided on a conductive support, those in which an inorganic pigment (titanium oxide, tin oxide, etc.) is dispersed in a resin (described in JP-A-61-204642), and the like. Has been. Since this method has relatively low cost and good effect, it is applied to many photoreceptors.

However, a conventional resin-only intermediate layer,
Alternatively, the photoreceptor having a structure in which an intermediate layer in which an inorganic pigment is dispersed in a resin is provided maintains good characteristics in the initial stage, but when repeatedly used over tens of thousands of sheets over a long period of time, the image is gradually changed. The actual situation is that the above defects (ground stains, black spots, etc.) become prominent.

In recent years, digitalization has been rapidly progressing, and these printers and copying machines are required to have a photoconductor prescription corresponding to the digitalization and corresponding to a semiconductor laser which is monochromatic light. There is. One of the prescriptions for this is prevention of abnormal images such as moiré, but the intermediate layer plays a major role in this prevention, and it is said that the inclusion of metal oxide fine particles and organic fine particles in the intermediate layer prevents moiré. Things have also been done. There are the following cases for the middle class.

(1) Japanese Unexamined Patent Publication No. 11-15181 A surface of an aluminum or aluminum alloy support is anodized and then mechanically polished, and then subjected to hot water sealing treatment, sealing treatment or humidification sealing treatment. An electrophotographic photoreceptor comprising a photosensitive layer provided on a photoreceptor substrate obtained by the application. (2) JP-A-10-301314 SUMMARY OF THE INVENTION In an electrophotographic photosensitive member in which at least an undercoat layer and a photosensitive layer are provided on a conductive support, colloidal alumina is added to a certain organoalkoxysiloxane as the undercoat layer. An electrophotographic photosensitive member composed of a mixture obtained by heating and curing a composition. (3) JP-A-10-90931 SUMMARY OF THE INVENTION In an electrophotographic photoreceptor in which at least an undercoat layer and a photosensitive layer are provided on a conductive support, a resin in the undercoat layer contains heat-treated titanium oxide. An electrophotographic photosensitive member characterized by the following. (4) JP-A-5-204181 An electrophotographic photosensitive member comprising a support, a conductive polyaniline layer and a photosensitive layer laminated on the support. (5) JP-A-8-44096 SUMMARY OF THE INVENTION In an electrophotographic photoreceptor having an undercoat layer containing titanium oxide and a thermosetting resin on a support and a photosensitive layer, the thermosetting resin contained in the undercoat layer is used. Volume content is 0.5 ~
An electrophotographic photosensitive member having a particle size of 0.6 and an average particle size of titanium oxide in the undercoat layer of 0.4 μm or less. An electrophotographic device using reversal development using this photoconductor. (6) Japanese Unexamined Patent Publication No. 9-34152 SUMMARY OF THE INVENTION Metal alkoxide, organometallic chelate, silane coupling agent on a conductive substrate made of pure aluminum, aluminum-manganese alloy, aluminum-magnesium alloy or aluminum-magnesium-silica alloy. And an undercoat layer containing a compound selected from the reaction products thereof, and a photoconductive layer in this order. (7) Japanese Unexamined Patent Publication No. 9-292730 An anodized layer and a photosensitive layer are formed on a conductive support made of aluminum or an aluminum alloy, and the ridge spacing Sm on the surface of the anodized layer is 0.3 to 250 μm and the maximum height is high. R
An electrophotographic photosensitive member for reversal development having a t of 0.5 to 2.5 μm and a surface glossiness of 60 gloss or more on the surface of the anodized layer. (8) Japanese Patent Laid-Open No. 10-83093 An electrophotographic photosensitive member having an intermediate layer containing titanium oxide fine powder having zirconium oxide at least on the surface between a conductive support and a photosensitive layer. (9) JP-A No. 11-321788 SUMMARY OF THE INVENTION In an electrophotographic photoreceptor having an undercoat layer between a conductive substrate and a photosensitive layer laminated thereon, the undercoat layer is anatase / rutile in a resin. Mixed crystal titanium dioxide is dispersed.

In the above (1) to (9), the structure of the intermediate layer between the conductive support and the photosensitive layer and the substance contained therein are changed, or an anodic oxide coating is provided on the surface of the conductive support. By preventing the injection of holes from the conductive substrate to the photosensitive layer or the charge generation layer during reversal development,
The purpose is to prevent the generation of black spots and black spots. However, even with these conventional techniques, high image quality in recent years and
The current situation is that an intermediate layer corresponding to high durability has not been obtained.

The electrophotographic photosensitive member is manufactured by coating a photosensitive layer on a conductive support, but a non-cutting aluminum tube may be used to reduce the cost of the conductive support. As a non-cutting aluminum tube for this,
As described in Japanese Patent Application Laid-Open No. 3-192265, after the aluminum disc is deep-drawn into a cup shape, the outer surface of the DI pipe is finished by the ironing process, and the aluminum disc is subjected to impact processing to form a cup. After making a state,
II pipe whose outer surface is finished by ironing, EI whose outer surface of aluminum extruded pipe is finished by ironing
Known are tubes and ED tubes that have been cold drawn after extrusion.

However, the non-cutting aluminum tube has a smoother surface morphology than the cutting tube, and abnormal images such as moire are likely to occur. As described in Japanese Patent Application Laid-Open No. 3-192265, streak-shaped defects caused by a difference in physical shape of the surface and residual deposits, and Japanese Patent Application Laid-Open No. 4-32
As described in Japanese Patent No. 6357, there are some in which fine convex defects (projection defects) in a crispy shape are generated. Further, since the anchor effect cannot be expected, there is a problem that the adhesiveness with the photosensitive layer is further lowered.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems, to provide an electrophotographic photosensitive member which gives a high quality image without image defects and is excellent in durability. is there. A further object of the present invention is to provide an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus that use an electrophotographic photosensitive member that gives a high-quality image without image defects and is excellent in durability. is there.

[0012]

As a result of intensive studies on the above problems, the present inventor has found that the above problems can be solved by the following means, and has completed the present invention.
That is, the above-mentioned subject is (1) "In an electrophotographic photoreceptor having at least an intermediate layer and a photosensitive layer on a conductive support, the intermediate layer has at least a purity of 99.0%.
The two or more kinds of titanium oxides having different average particle diameters and the binder resin are contained, one titanium oxide (T ₁ ) has an average particle diameter of (D ₁ ) and the other titanium oxide (T ₂ ) has an average diameter. When the particle size is (D ₂ ), 1/5 <D ₂ / D ₁ ≦ 1 /
An electrophotographic photoconductor characterized by satisfying the relationship of 2>,
(2) “The titanium oxide (T ₂ ) has an average particle diameter (D ₂ ) of 0.05 μm <D ₂ <0.20 μm and a rutile conversion rate of 100 to 10%. the (1) the electrophotographic photosensitive member according to claim>, (3) "rutile content of the titanium oxide (T ₂₎ is, according to the first (2), characterized in that a 60 to 30% Electrophotographic photosensitive member ", (4)" the mixing ratio (weight ratio) of the two kinds of titanium oxides having different average particle diameters is 0.2≤T ₂ / (T ₁ +
T ₂ ) ≦ 0.8, wherein the first (1)
Item 5. The electrophotographic photoconductor according to any one of Items 1 to 3, "5", wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer. To the electrophotographic photosensitive member according to any one of (4) above,
(6) “In the above item (5), the charge generation layer comprises at least a binder resin and an azo pigment, and the azo pigment is an asymmetric disazo pigment represented by the following general formula (I). The described electrophotographic photoreceptor,

## STR00003 ## Cp ₁ -N = NA-N = N-Cp ₂ (I) (In the formula, A includes a carbon atom bonded to a nitrogen atom of each azo group; Cp ₁ and Cp ₂ represent coupler residues having different structures from each other.) ”, (7)
“The asymmetric azo pigment represented by the general formula (I) is a compound represented by the following general formula (II), and the electrophotographic photosensitive member according to the above item (6),

[0013]

[Chemical 4] And (8) "wherein the conductive support is a non-cutting aluminum tube, (1) to (7)
The electrophotographic photosensitive member according to any one of items 1 to 4.

Further, the above-mentioned problem is (9) of the present invention, "at least charging, image exposure, development, and transfer are repeatedly performed on an electrophotographic photoreceptor, and at the time of image exposure, the photoreceptor is exposed by an LD or an LED. In the so-called digital electrophotographic method, in which an electrostatic latent image is written on the surface of the electrophotographic photosensitive member and the development is performed by a reversal development method, the electrophotographic photosensitive member is any one of the above items (1) to (8). An electrophotographic method, which is the electrophotographic photosensitive member according to 1.
An electrophotographic apparatus comprising a reversal developing means, a transfer means, a charge removing means, and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is any one of items (1) to (8) above. (11) "Electrophotographic apparatus, characterized in that it is an electrophotographic apparatus," (11) "A process cartridge for an electrophotographic apparatus comprising at least an electrophotographic photoreceptor, the electrophotographic photoreceptor comprising: And a process cartridge for an electrophotographic apparatus, which is the electrophotographic photosensitive member according to any one of items (1) to (8).

The present invention will be described in detail below. The titanium oxide shown in the present invention can be produced by the sulfuric acid method or the chlorine method, but the chlorine method is preferred to obtain high-purity titanium oxide. In the chlorine method, titanium slag as a raw material is chlorinated with chlorine to form titanium tetrachloride, which is then separated and
It is a production method in which titanium oxide is produced by condensing and purifying and then oxidizing, pulverizing and classifying the produced titanium oxide, subjecting it to a surface treatment, filtering, washing and drying, and then pulverizing. The particle size can be obtained by reducing the primary particle size of titanium oxide produced by oxidation.

Particle sizes having different average particle sizes as shown in the present invention
Concealment of conductive substrate by using titanium oxide
It is possible to improve power and suppress moire
In addition, you can eliminate pinholes that cause abnormal images.
Wear. To this end, the particle size of the two types of titanium oxide used
It is important that the ratio is within a certain range, and it is regulated by the present invention.
If the particle size ratio is outside the specified range, that is,
(T₁) Titanium oxide for the average particle size of
(T_TwoIf the ratio of the average particle size of () is too small (D_Two/ D ₁
≤ 1/5), the activity on the surface of titanium oxide is increased and
Electrostatic stability is significantly impaired when used as a true photoconductor
Like In addition, one of the titanium oxide (T₁) Average grain
The other titanium oxide (T_Two) Is the average particle size ratio
If too large (D_Two/ D₁> 1/2) is a conductive substrate
The hiding power for
Control is reduced. The average particle size was strongly dispersed in an aqueous system.
Obtained from particle size distribution measurements sometimes obtained.

The purity can be controlled by the purity of the raw material, the presence or absence of titanium oxide surface treatment, or the degree thereof, and particularly in the case of the chlorine method, high purity titanium oxide can be obtained. The titanium oxide shown in the present invention needs to have a purity of 99.0% or more. Impurities contained in the metal oxides are mainly hygroscopic substances such as Na ₂ O and K ₂ O and ionic substances. When the purity of the metal oxides is lower than 99.0%, the characteristics of the photoconductor are reduced. Is a cause of large fluctuation due to the environment (particularly humidity) and repeated use, which is not preferable. Further, these impurities are likely to cause image defects such as black spots. For example, the purity of titanium oxide is JIS
It can be determined by the measuring method shown in K5116.

Further, the titanium oxide shown in the present invention preferably has a rutile ratio of 100 to 10%. Generally, titanium oxide has two crystal types of anatase and rutile, and physical properties such as specific gravity, refractive index and hardness are different depending on the crystal types. The control of the crystal form between rutile and anatase depends on the sintering conditions when titanium oxide is produced. Under mild conditions, it becomes anatase type, and it changes to rutile type as the sintering temperature is raised. Therefore, the rutile ratio can be controlled by controlling the sintering conditions, and titanium oxide having the rutile ratio of 60 to 10% as shown in the present invention can be obtained. The reason why titanium oxide having a rutile ratio of 100 to 10% shown in the present invention is preferable is not clear, but by setting it in this range, defects on an image, specifically, background stain can be improved. The rutile ratio can be obtained from the intensity of the interference line resulting from each crystal type in powder X-ray diffraction. In particular, the rutile ratio of titanium oxide is preferably 60 to 30%.

Further, regarding the mixing ratio (weight ratio) of two kinds of titanium oxides having different average particle sizes shown in the present invention, if the mixing ratio is less than 0.2, an abnormal image (particularly black spots / background stains) is obtained. When the mixing ratio is greater than 0.8, the light scattering power in the intermediate layer is reduced, and moire is likely to occur.

Further, the effect of the present invention is further improved by using the asymmetric disazo pigment having the asymmetric disazo content represented by the general formula (I), more preferably the fluorenone represented by the general formula (II) in the central skeleton as the charge generating substance. It will be effective. Although the reason why the asymmetric disazo pigment shown in the present invention is preferable is not clear, it is thought that the influence of the formulation in the intermediate layer is effectively acting from the relationship between the ionization potential of the intermediate layer and the asymmetric disazo pigment. ing.

The present invention will be described below with reference to the constitution of the electrophotographic photosensitive member. FIG. 1 is a cross-sectional view showing a constitutional example of the electrophotographic photosensitive member of the present invention, in which an intermediate layer (23) containing at least the titanium oxide shown in the present invention and a photosensitive layer are provided on a conductive support (21). (25) is laminated.

FIG. 2 is a cross-sectional view showing another constitutional example of the electrophotographic photosensitive member of the present invention, in which an intermediate layer (23) containing at least titanium oxide is provided on a conductive support (21). The charge generation layer (27) and the charge transport layer (29) are laminated.

FIG. 3 is a cross-sectional view showing still another constitutional example of the present invention, in which the protective layer (3) is formed on the charge transport layer (29).
1) is provided.

The conductive support (21) has a volume resistance of 10 ¹⁰ Ω · cm or less, for example, aluminum, nickel, chromium, nichrome, copper, gold,
Metals such as silver and platinum, metal oxides such as tin oxide and indium oxide are vapor-deposited or sputtered to form film-shaped or cylindrical plastics, paper-coated materials, or nickel and stainless steel plates and those extruded, It is possible to use a tube that has been subjected to a surface treatment such as cutting, superfinishing, polishing, etc. after forming a raw tube by a method such as drawing. JIS 3003 for aluminum tube
Type, JIS5000 type, JIS6000 type, etc. aluminum alloys formed into a tubular shape by a general method such as the EI method, the ED method, the DI method, and the II method, and further surface cutting and polishing with a diamond bite, etc. A product that has been subjected to anodizing treatment or the like can be used.

The endless nickel belt and the endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support (21). Further, as described above, a non-cutting aluminum tube may be used to reduce the cost of the conductive support. As a non-cutting aluminum pipe for this purpose, as described in JP-A-3-192265, a DI pipe in which an aluminum disk is deep-drawn into a cup shape and then the outer surface is finished by ironing After the aluminum disc is impact processed into a cup shape, the outer surface of the II pipe is finished by ironing, the EI pipe of the outer surface of the aluminum extruded pipe is finished by ironing, and the ED is cold drawn after extrusion. The tube is known. These non-cutting aluminum pipes are prone to abnormal images such as moire as described above, but according to the present invention, as is clear from the examples described later, the non-cutting aluminum pipes are used. However, an abnormal image such as moire does not occur, and in the present invention, the non-cutting aluminum tube can be used to provide an electrophotographic photoreceptor having high image quality and excellent durability.

In addition, in recent years, a support obtained by dispersing a conductive powder in an appropriate binder resin and coating it on a support made of plastic is also used as the conductive support (21) of the present invention. You can Examples of the conductive powder include carbon black, acetylene black, metal powder of aluminum, nickel, iron, nichrome, copper, zinc, silver, etc., or conductive titanium oxide, conductive tin oxide, IT.
Examples thereof include metal oxide powder such as O. Further, the binder resin used at the same time, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene,
Thermoplastics such as poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin,
A thermosetting resin or a photocurable resin may be used. Such a conductive layer can be provided by dispersing and coating the conductive powder and the binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, 2-butanone, or toluene.

Further, the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and polytetrafluoroethylene fluororesin on a suitable cylindrical substrate. Those provided with a conductive layer by a heat-shrinkable tube can also be favorably used as the conductive support (21) of the present invention.

The intermediate layer (23) is mainly composed of titanium oxide and a resin as shown in the present invention. Considering that the photosensitive layer is coated on the resin with a solvent, the resin is used for a general organic solvent. It is desirable that the resin has high solvent resistance. Such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymer nylon, alcohol-soluble resins such as methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy. Examples of the resin include curable resins that form a three-dimensional network structure, such as resins. In addition, regarding the weight ratio of titanium oxide and resin, titanium oxide /
Resin = 3/1 to 8/1 is preferable. If it is 3/1 or less, the carrier transporting ability of the intermediate layer is lowered, a residual potential is generated, and the photoresponsiveness is lowered. When it is 8/1 or more, voids in the intermediate layer increase, and bubbles are generated when the photosensitive layer is coated on the intermediate layer. These intermediate layers (23) can be formed by using an appropriate solvent and coating method as in the above-mentioned photosensitive layer. The suitable thickness of the intermediate layer (23) is 1.0 to 10 μm. In addition, titanium oxide (T
The average particle diameters of ₁ ) and (T ₂ ) may be within the range of the relational expression shown in claim 1.

The charge generating layer (27) contains at least a charge generating substance and, if necessary, a binder resin. As the binder resin, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicon resin, acrylic resin, polyvinyl butyral, polyvinyl formal,
Polyvinyl ketone, polystyrene, polysulfone, poly-N-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin , Casein, polyvinyl alcohol, polyvinylpyrrolidone and the like. The amount of the binder resin is appropriately 0 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the charge generating substance.

Examples of the charge generating substance include phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azurenium salt pigments, methine squarate citrate pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and Use azo pigments such as triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, monoazo pigments, bisazo pigments, asymmetric disazo pigments, trisazo pigments and tetraazo pigments. You can

Specific examples of the azo pigment include an azo pigment having a carbazole skeleton (described in JP-A-53-95033) and an azo pigment having a triphenylamine skeleton (described in JP-A-53-132547). ), An azo pigment having a stilstilbene skeleton (JP-A-53-1382).
29), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), and azo pigments having a fluorenone skeleton (JP-A-54-228).
34), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), azo pigments having a bisstilbene skeleton (JP-A-54-177).
No. 33), an azo pigment having a distyryloxadiazole skeleton (described in JP-A-54-2129), an azo pigment having a distyrylcarbazole skeleton (described in JP-A-54-17734). And so on. Two or more kinds of these charge generating substances may be mixed and used.

Among these charge generating substances, it is preferable to use the extremely sensitive asymmetric disazo pigment represented by the general formula (I), and these asymmetric disazo pigments are
Corresponding diazonium salt compound and Cp ₁ or Cp ₂
Or a diazonium salt compound obtained by the first coupling reaction with Cp ₁ or Cp ₂ is isolated.
Further, it can be obtained by reacting the remaining coupler. These asymmetric disazo pigments A, Cp ₁ ,
Examples of Cp ₂ are shown in Table 1.

[0033]

[Table 1-1]

[0034]

[Table 1-2]

[0035]

[Table 1-3]

[0036]

[Table 1-4]

[0037]

[Table 1-5]

[0038]

[Table 1-6]

[0039]

[Table 1-7]

[0040]

[Table 1-8]

[0041]

[Table 1-9]

Among these asymmetric disazo pigments, N
o. The compound represented by the general formula (II) having the fluorenone central skeleton represented by A-20 is particularly preferable from the viewpoint of sensitivity and potential stability.

Specific examples of the asymmetric disazo pigment represented by the general formula (II) are shown below, but the invention is not limited thereto. In formula (II), preferred examples of couplers A and B include coupler residues represented by the following formulas (IV) to (IX).

[0044]

[Chemical 5]

[0045]

[Chemical 6]

[0046]

[Chemical 7]

[0047]

[Chemical 8]

[0048]

[Chemical 9]

[0049]

[Chemical 10]

In the general formulas (IV) and (V), X is condensed with a benzene ring to form a naphthalene ring, anthracene ring, carbazole ring, benzcarbazole ring, dibenzofuran ring,
It represents a residue necessary for forming a hydrocarbon ring such as a dibenzothiophene ring or a heterocyclic group. The residue may have a substituent. In formula (IX), Y represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent heterocyclic group containing a nitrogen atom in the ring. General formulas (IV) and (V)
Wherein R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group, and R ₁ , R ₂ , R ₃ and R ₄ may bond a nitrogen atom together to form a cyclic amino group containing a nitrogen atom in the ring. In formula (VI), R ₅ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group. In the general formulas (VII) and (VIII), R ₆ ,
R ₇ is an alkyl group which may have a substituent, an aryl group,
Represents an aralkyl group or a heterocyclic group. General formula (VI),
In (VII), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent or a heterocyclic group. In the general formula (IV), p
Represents 0 or 1.

Examples of the alkyl group represented above include groups such as methyl, ethyl and propyl, examples of the aralkyl group include groups such as benzyl and phenethyl, examples of the aryl group include groups such as phenyl, naphthyl and anthryl, and examples of the heterocyclic group include pyridyl. Examples thereof include groups such as thienyl, thiazolyl, carbazolyl, benzimidazolyl and benzothiazolyl, and examples of the cyclic amino group containing a nitrogen atom in the ring include pyrrole, pyrroline, pyrrolidine, pyrrolidone, indole,
Indolyl, carbazole, imidazole, pyrazole, pyrazoline, oxazine, phenoxazine and the like can be mentioned.

As the substituent, methyl, ethyl,
Alkyl groups such as propyl and butyl, alkoxy groups such as methoxy, ethoxy and propoxy, halogen atoms such as fluorine atom, chlorine atom and bromine atom, dimethylamino,
Examples thereof include a dialkylamino group such as diethylamino, a phenylcarbamoyl group, a nitro group, a cyano group, and a halomethyl group such as trifluoromethyl.

Specific examples of the disazo pigment represented by the general formula (I) are shown below, but the disazo pigment of the present invention is not limited to these.

[0054]

[Table 2-1]

[0055]

[Table 2-2]

[0056]

[Table 2-3]

[0057]

[Table 2-4]

[0058]

[Table 2-5]

[0059]

[Table 2-6]

[0060]

[Table 2-7]

[0061]

[Table 2-8]

[0062]

[Table 2-9]

[0063]

[Table 2-10]

For the charge generation layer (27), at least the charge generation substance and, if necessary, the binder resin are dispersed in a suitable solvent by using a ball mill, an attritor, a sand mill, ultrasonic waves or the like to prepare a coating solution, It is formed by coating on the intermediate layer (23) and drying. Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, dioxolane, ethyl cellosolve, ethyl acetate, acetic acid. Methyl, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene,
Examples include xylene and ligroin. As the coating method of the coating liquid, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used. The film thickness of the charge generation layer (27) is appropriately about 0.01 to 5 μm, preferably 0.05 μm.
It is 1 to 2 μm.

The charge transport layer (29) is a layer containing a charge transport material as a main component, and the charge transport material and the binder resin are used as a suitable solvent, for example, tetrahydrofuran, dioxane, dioxolane, anisole, toluene, monochlorobenzene, dichloroethane, It can be formed by dissolving or dispersing in methylene chloride, cyclohexanone, etc., applying the solution or dispersion, and drying.

The charge-transporting substance includes a hole-transporting substance and an electron-transporting substance. Examples of the electron-transporting substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro. -9-
Fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6
8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, 3,5-dimethyl-
Known electron-accepting substances such as 3 ', 5'-ditert-butyl-4,4'-diphenoquinone and other benzoquinone derivatives can be mentioned. These electron transport materials can be used alone or as a mixture of two or more kinds.

As the hole-transporting substance, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative, diarylamine derivative, triarylamine derivative, stilbene derivative,
α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9
-Styrylanthracene derivative, pyrazoline derivative, divinylbenzene derivative, hydrazone derivative, indene derivative, butadiene derivative, pyrene derivative, bisstilbene derivative, enamine derivative, thiazole derivative, triazole derivative, phenazine derivative, acridine derivative,
Examples thereof include a benzofuran derivative, a benzimidazole derivative, and a thiophene derivative. These hole-transporting substances can be used alone or as a mixture of two or more kinds.

The binder resin used in the charge transport layer includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-acetic acid. Vinyl copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate (bisphenol A type, bisphenol Z type, etc.), cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene , Poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, JP-A-5-158250 and JP-A-6-515.
Examples thereof include thermoplastic or thermosetting resins such as various polycarbonate copolymers described in JP-A-44.

Further, as the binder resin, a polymer charge transporting material having a function as a binder resin and a function as a charge transporting material can also be used. Examples of such a polymer charge transporting substance include (a) a polymer having a carbazole ring in its main chain and / or side chain, for example, poly-N-vinylcarbazole, JP-A-50-
Examples thereof include the compounds described in JP-A-82056, JP-A-54-9632, JP-A-54-11737, and JP-A-4-183719. (B) A polymer having a hydrazone structure in the main chain and / or side chain, for example, JP-A-57-78402 and JP-A-3-5.
Examples thereof include the compounds described in 0555. (C) Polysilylene polymer For example, JP-A-63-285552, JP-A-5-
Examples thereof include compounds described in 19497 and JP-A-5-70595. (D) A polymer having a tertiary amine structure in the main chain and / or side chain, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-13061, JP-A-1-13061. -19049, Japanese Patent Laid-Open No. 1-1728,
JP-A-1-105260, JP-A-2-16733
5, JP-A-5-66598, and JP-A-5-4.
Examples thereof include the compounds described in Japanese Patent No. 0350.

The amount of the binder resin used is the charge transport material 100.
0 to 200 parts by weight is suitable with respect to parts by weight.

If necessary, a plasticizer, a leveling agent, an antioxidant, etc. may be added to the charge transport layer. Examples of such plasticizers include halogenated paraffin, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate and the like, and polymers and copolymers of polyester and the like.

The amount used is appropriate to be about 0 to 30 parts by weight with respect to 100 parts by weight of the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount thereof is 0 to 1 weight with respect to the binder resin. Some parts are appropriate. Further, an antioxidant can be added in order to improve the environmental resistance to oxidizing gases such as ozone and NOx. The antioxidant may be added to any layer containing an organic substance,
Good results are obtained when added to the layer containing the charge transport material.

As the antioxidant, antioxidants such as hindered phenol compounds, sulfur compounds, phosphorus compounds, hindered amine compounds, pyridine derivatives, piperidine derivatives and morpholine derivatives can be used. About 0 to 5 parts by weight is suitable for 100 parts by weight of the resin. The film thickness of the charge transport layer thus formed is suitably about 5 to 50 μm.

The photosensitive layer (25) of the single-layer type photoreceptor comprises a charge generating substance, the dispersant of the present invention, a charge transporting substance, and a binder resin. As the charge generating substance, the dispersant, and the charge transporting substance, the above materials can be used. To form such a single-layer type photosensitive layer, a charge-generating substance, a charge-transporting substance, a dispersant and a binder resin in a suitable solvent, for example, tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone or the like ball mill, It may be dissolved or dispersed by an attritor, a sand mill, etc., diluted appropriately and then applied and dried. The coating can be carried out using a dip bond coating method, a spray coating method, a roll coating method, a blade coating method, or the like. As the binder resin, the binder resin exemplified as the binder resin of the charge transport layer may be used as it is, or may be mixed with the binder resin exemplified as the binder resin of the charge generation layer. Also, a single-layer type photosensitive layer obtained by adding a charge transporting substance to a eutectic complex formed of a pyrylium dye and bisphenol A type polycarbonate may be formed by the same coating method as above using an appropriate solvent. it can.

If necessary, a plasticizer, a leveling agent, an antioxidant, etc. may be added to the single-layer type photosensitive layer. The film thickness of the single-layer type photosensitive layer formed in this manner is appropriately about 5 to 50 μm.

The protective layer (31) is provided for the purpose of improving the durability of the photoconductor, and the materials used for it are ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin. , Phenol resin, polyacetal, polyamide, polyamide imide,
Polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate,
Polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide,
Polysulfone, polystyrene, AS resin, butadiene-
Examples of the resin include styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin and polyester.

The protective layer (31) includes a fluorine resin such as polytetrafluoroethylene, a silicone resin, titanium oxide, aluminum oxide, tin oxide, zinc oxide, zirconium oxide, magnesium oxide for the purpose of improving wear resistance. , Silica and inorganic materials such as surface-treated products thereof can be added, and those to which a charge transport substance is further added can be used. As a method for forming the protective layer (31), an ordinary coating method can be used. It is suitable that the protective layer (31) has a thickness of 0.1 to 10 μm. In addition to the above, aC, a formed by a vacuum thin film forming method
A known material such as —SiC can also be used as the protective layer (31).

In the present invention, it is possible to provide another intermediate layer (not shown) between the photosensitive layer (25) and the protective layer (31). The another intermediate layer generally uses a resin as a main component. Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble butyral resin, polyvinyl butyral, and polyvinyl alcohol. As the method for forming the another intermediate layer, a usual coating method can be used as described above. The film thickness is 0.0
5-2 μm is suitable.

Next, the electrophotographic method and electrophotographic apparatus of the present invention will be described in detail. FIG. 4 is a schematic diagram for explaining the electrophotographic method and the electrophotographic apparatus of the present invention, and the following modified examples also belong to the scope of the present invention. In FIG. 4, the photoconductor (1) has a drum shape, but may have a sheet shape or an endless belt shape. The charging charger (3), pre-transfer charger (7), transfer charger (10), separation charger (11), pre-cleaning charger (13) include corotron, scorotron, solid state charger (solid state charger), and charging. Well-known means such as rollers are used.

Generally, the above-mentioned charger can be used as the transfer means, but it is effective to use a transfer charger and a separation charger together as shown in the figure.

The light sources such as the image exposure section (5) and the static elimination lamp (2) include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LED), semiconductor lasers (LD), electro Luminescent materials such as luminescence (EL) can be used in general. Further, various filters such as a sharp cut filter, a bandpass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range. Such a light source or the like irradiates the photoconductor with light by providing a process such as a transfer process using light irradiation, a charge eliminating process, a cleaning process, or a pre-exposure process in addition to the process shown in FIG.

The toner developed on the photoconductor (1) by the developing unit (6) is transferred to the transfer paper (9), but not all of the toner is transferred, and the photoconductor (1) is not transferred.
Toner that remains on top is also produced. Such toner is removed from the photoreceptor by the fur brush (14) and / or the cleaning blade (15). Cleaning may be performed only with a cleaning brush, and known cleaning brushes such as a fur brush and a magfur brush are used.

When the electrophotographic photosensitive member is positively (negatively) charged and imagewise exposed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. This is a negative (positive) polarity toner (electrolytic fine particles)
By developing with, a positive image can be obtained, and by developing with a toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to the developing means, and a known method is used for the charge removing means.

The above-described electrophotographic method illustrated is an example of the embodiment of the present invention, and, of course, other embodiments are possible. For example, the image forming means forming the electrophotographic apparatus may be incorporated in a copying machine, a facsimile machine, or a printer in the form of a process cartridge. The process cartridge is one device (component) that contains a photoconductor and that also includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit. Although there are many shapes of process cartridges and the like, as a general example, IMAGIO MF200
A cartridge used in (manufactured by Ricoh Co., Ltd.) is shown in FIG.

FIG. 5 is a diagram showing an example of an electrophotographic apparatus using an electrophotographic process cartridge. This apparatus will be described below. In the figure, (101) is an electrophotographic photoreceptor. First, the photoconductor is charged by the charging device (102). After the photoreceptor is charged, exposure (103)
In response to this, electric charge is generated in the exposed portion, and an electrostatic latent image is formed on the surface of the photoconductor. After forming an electrostatic latent image on the surface of the photoconductor, it contacts the developer through the developing device (104),
Form a toner image. The toner image formed on the surface of the photoconductor is transferred by a transfer device (106) to a transfer member (10) such as paper.
5) and is passed through the fixing device (109) to become a hard copy. The residual toner on the electrophotographic photosensitive member (101) is removed by the cleaning blade (107), the residual charge is removed by the charge eliminating lamp (108), and the process proceeds to the next electrophotographic cycle. In this device, the transfer body (105), the transfer device (106), the static elimination lamp (10
8), the fixing device (109) is not included in the cartridge portion.

On the other hand, in the light irradiation step, image exposure, pre-cleaning exposure, and static elimination exposure are shown. In addition, pre-transfer exposure, pre-exposure for image exposure, and other known light irradiation steps are provided to expose the photosensitive material. The body can also be irradiated with light.

[0087]

EXAMPLES Next, the present invention will be explained based on examples, but the present invention is not limited to these examples. In the examples, all parts are parts by weight. Example 1 Titanium oxide T ₂ (purity: 99.8%, rutile conversion rate: 100)
%, Average particle size 0.07 μm) 30 parts by weight, titanium oxide T
₁ (Purity: 99.8%, rutile ratio 100%, average particle size 0.25 μm) 40 parts by weight, alkyd resin (Beckolite M6401-50-S (solid content 50%), manufactured by Dainippon Ink and Chemicals) 18 parts by weight, melamine resin (Super Beckamine G-821-60 (solid content 60%), manufactured by Dainippon Ink and Chemicals, Inc.) 10 parts by weight, methyl ethyl ketone 1
A mixture of 00 parts by weight was dispersed by a ball mill for 72 hours to prepare a coating liquid for intermediate layer. Diameter of this is φ30m
It was applied onto a non-cutting aluminum tube having a length of m and a length of 340 mm and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 3.5 μm.

Next, 10 parts of trisazo pigment represented by the following structural formula (III) and 4 parts of polyvinyl butyral (BM-1: manufactured by Sekisui Chemical Co., Ltd.) were added to a resin solution dissolved in 150 parts of cyclohexanone, and a ball mill was used. Dispersion was carried out for 72 hours. After the dispersion was completed, 210 parts by weight of cyclohexanone was added and dispersion was carried out for 3 hours to prepare a charge generation layer coating liquid. This was applied onto the intermediate layer and dried at 130 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm. next,
7 parts of a compound represented by the following structural formula (IV), 10 parts of a polycarbonate resin (TS-2050: manufactured by Teijin Chemicals Ltd.), silicone oil (KF-50: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.00
2 parts was dissolved in 100 parts tetrahydrofuran to prepare a charge transport layer coating liquid. This was applied onto the charge generation layer and dried at 135 ° C. for 20 minutes to form a charge transport layer having an average film thickness of 23 μm, to obtain an electrophotographic photoreceptor.

[0089]

[Chemical 11]

[0090]

[Chemical 12]

Example 2 Electrophotographic exposure was carried out in the same manner as in Example 1 except that titanium oxide having an average particle diameter of 0.07 μm and having a rutile conversion rate of 40% was used in the coating liquid for the intermediate layer. Created the body.

Comparative Example 1 Titanium oxide having an average particle size of 0.07 μm used in the coating liquid for the intermediate layer was used except that the purity was 99.5%, the rutile conversion rate was 100%, and the average particle size was 0.02 μm. In the same manner as in Example 1, an electrophotographic photosensitive member of Comparative Example 1 was prepared.

Comparative Example 2 Comparative Example 2 was carried out in the same manner as in Example 1 except that titanium oxide having an average particle size of 0.07 μm and a purity of 98.0% was used in the coating liquid for the intermediate layer. An electrophotographic photoreceptor was created.

The electrophotographic photosensitive member thus obtained was evaluated as follows. Regarding the electrophotographic photosensitive member, the image and potential characteristics were evaluated by modifying the Imagio MF2200 (manufactured by Ricoh Co., Ltd.) using a semiconductor laser of 655 nm as an image exposure light source. First, for image evaluation,
The dark potentials (VD) shown below are -690 V and-, respectively.
The number of black spots of 0.1 mm or more appearing in the central 5 cm × 5 cm of the A4 white paper when changed to 805 V and 920 V and the presence or absence of other abnormal images were examined.
In addition, as the electrostatic characteristics of the photoconductor, the above-mentioned Imagio MF220
0 (manufactured by Ricoh Co., Ltd.), and the dark part potential (VD) was -7
The fluctuation range ΔVL = VL (initial) -VL (3) for the bright part potential (VL) at 00V in the initial and after 30,000 continuous runs.
(After running 10,000 sheets). Dark part potential (VD): Photoconductor surface potential when moving to the developing part position after primary charging Bright part potential (VL): When image exposure (solid exposure) is received after the primary charging and moving to the developing part position Table 3 shows the results of the surface potential of the photoreceptor.

[0095]

[Table 3]

Example 3 An electrophotographic photosensitive member of Example 3 was prepared in the same manner as in Example 1 except that an asymmetric disazo pigment represented by the following structural formula (V) was used instead of the trisazo pigment used in Example 1. did.

[0097]

[Chemical 13]

Example 4 An electrophotographic photosensitive member of Example 4 was prepared in the same manner as in Example 1 except that the asymmetric disazo pigment represented by the following structural formula (VI) was used instead of the trisazo pigment used in Example 1. did.

[0099]

[Chemical 14]

Example 5 An electrophotographic photosensitive member of Example 5 was prepared in the same manner as in Example 1 except that the asymmetric disazo pigment represented by the following structural formula (VII) was used instead of the trisazo pigment used in Example 1. did.

[0101]

[Chemical 15]

Examples 6 to 15 and Comparative Examples 3 to 9 Electrophotographic photoreceptors of Examples and Comparative Examples were prepared in the same manner as in Example 5 except that titanium oxide was changed as shown in Table 4. .

[0103]

[Table 4]

As described above, obtained Examples 3 to 15 and Comparative Example 3
With respect to the electrophotographic photoconductors Nos. 9 to 9, the image and potential characteristics were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[0105]

[Table 5]

[0106]

As is clear from the above detailed and specific description, the use of the intermediate layer containing two kinds of titanium oxides of high purity and different in average particle diameter as shown in the present invention provides an image It is possible to obtain an electrophotographic photosensitive member which does not have an abnormal image such as black spots and has good electrostatic characteristics, and has good characteristics without causing moire even in an inexpensive non-cutting raw tube. Further, by specifying the rutile conversion rate of titanium oxide to be used, it is possible to further improve an abnormal image such as black spots. Further, the electrophotographic apparatus using the electrophotographic photosensitive member of the present invention and the process cartridge for the electrophotographic apparatus can have good characteristics.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of an electrophotographic photosensitive member of the present invention.

FIG. 2 is a cross-sectional view showing another configuration example of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a sectional view showing another configuration example of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a schematic diagram for explaining an electrophotographic method and an electrophotographic apparatus of the present invention.

FIG. 5 is a diagram showing an example of an electrophotographic apparatus using the electrophotographic process cartridge of the present invention.

[Explanation of symbols]

1 photoconductor 2 Static elimination lamp 3 Charger 4 Eraser 5 Image exposure unit 6 Development unit 7 Charger before transfer 8 Registration roller 9 Transfer paper 10 Transfer charger 11 Separation Charger 12 separate nails 13 Charger before cleaning 14 fur brush 15 cleaning brush 21 conductive support 23 Middle class 25 Photosensitive layer 27 Charge generation layer 29 Charge transport layer 31 Protective layer 101 photoconductor (photosensitive drum) 102 charging device 103 exposure 104 developing device 105 transfer body 106 transfer device 107 cleaning blade 108 Static elimination lamp 109 fixing device

Claims (11)

[Claims] 1. An electrophotographic photoreceptor having at least an intermediate layer and a photosensitive layer on a conductive support, wherein the intermediate layer has at least two kinds of titanium oxide having a purity of 99.0% or more and different average particle diameters. When the average particle diameter of _one titanium oxide (T ₁ ) is (D ₁ ) and the average particle diameter of the other titanium oxide (T ₂ ) is (D ₂ ), 1 / An electrophotographic photosensitive member characterized by satisfying a relationship of 5 <D ₂ / D ₁ ≦ 1/2. _2. The average particle diameter (D) of the titanium oxide (T ₂ ).
_{2. The} electrophotographic photosensitive member according to claim 1, wherein ₂ ) is 0.05 μm <D ₂ <0.20 μm, and the rutile ratio is 100 to 10%. 3. The electrophotographic photoreceptor according to claim 2, wherein the titanium oxide (T ₂ ) has a rutile ratio of 60 to 30%. 4. The mixing ratio (weight ratio) of the two kinds of titanium oxides having different average particle diameters is 0.2 ≦ T ₂ / (T ₁ +
4. The electrophotographic photosensitive member according to claim 1, wherein T ₂ ) ≦ 0.8. 5. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer. 6. The charge generation layer comprises at least a binder resin and an azo pigment, and the azo pigment has the following general formula (I):
The electrophotographic photosensitive member according to claim 5, which is an asymmetric disazo pigment represented by. Embedded image Cp ₁ -N = NA-N = N-Cp ₂ (I) (In the formula, A includes a carbon atom bonded to the nitrogen atom of each azo group; (Cp ₁ and Cp ₂ are coupler residues having different structures from each other.) 7. The electrophotographic photosensitive member according to claim 6, wherein the asymmetric azo pigment represented by the general formula (I) is a compound represented by the following general formula (II). [Chemical 2] 8. The electrophotographic photosensitive member according to claim 1, wherein the conductive support is a non-cutting aluminum tube. 9. An electrophotographic photosensitive member is repeatedly subjected to at least charging, image exposure, development and transfer, and at the time of image exposure, an electrostatic latent image is written on the photosensitive member by LD or LED. Further, in a so-called digital electrophotographic method in which development is performed by a reversal development method, the electrophotographic photoreceptor is the electrophotographic photoreceptor according to any one of claims 1 to 8. . 10. At least a charging means, an image exposing means,
An electrophotographic apparatus comprising a reversal developing means, a transfer means, a charge eliminating means and an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 8. An electrophotographic device characterized in that 11. A process cartridge for an electrophotographic apparatus, comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 1 to 8. A process cartridge for an electrophotographic apparatus, which is characterized by: