JPH0545908A - Electrophotographic organic sensitive body - Google Patents

Abstract

PURPOSE:To provide the single layer dispersion type electrophotographic organic sensitive body restrained in residual potential to a low level and superior in sensitivity. CONSTITUTION:The electrophotographic organic sensitive body is provided on a conductive substrate 1 with an organic photosensitive layer 2 made of a composition comprising a charge generating material CG, a positive hole transfer material HT, and a benzoquinone derivative as an electron transfer material ET having a reduction potential of -0.8 to -1.3V, each dispersed into a resin medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic organic photoreceptor useful for copying machines, laser printers and the like, and more particularly to an electrophotographic organic photoreceptor having improved sensitivity and residual potential.

[0002]

2. Description of the Related Art In electrophotographic copying using a digital optical system, a light source having a wavelength of 700 nm or more is usually used. Organic photoconductors (OPC), amorphous silicon (α-S) are used as photoconductors having sensitivity in this wavelength region.
i), some selenium photoreceptors are known, but the sensitivity,
From a comprehensive viewpoint of cost and the like, OPC is often used in this field.

As an organic photoreceptor, a charge generation layer (CG
L) and a charge transport layer (CTL) are stacked, so-called function-separated type organic photoconductors, that is, multi-layered photoconductors are often used, but a single layer dispersion type in which a charge generation substance is dispersed in a medium of a charge transport substance. The organic photoconductor of is also already known. As a charge transport material for this type of photoconductor, one having a high carrier mobility is required, but most of the charge transport agents having a high carrier mobility have a hole transporting property, so that they are practically used. What is present is limited to negatively charged organic photoconductors. However,
Negatively charged organic photoconductors use a negative corona discharge to generate a large amount of ozone, which causes problems such as environmental pollution and photodegradation. To prevent this, do not generate ozone. A special charging system, a system for decomposing generated ozone, a system for exhausting ozone in the apparatus, and the like are required, and there is a drawback that the process and the system are complicated. In addition, in the case of a laminated type photoreceptor, there is an optical problem that interference fringes are likely to occur because the photosensitive layer needs to be coated twice or the interface between the charge generation layer and the charge transport layer is present in the photoreceptor layer. is there.

As a single-layer dispersion type organic photoreceptor, JP-A-59 / 1984
JP-A-174849 discloses the use of a photosensitive layer containing, as essential components, three components of a perylene pigment, a photoconductive polymer such as PVK, and an electron-accepting substance that does not exert an optical sensitizing action on the photoconductive polymer. Is proposed. Further, as a few examples of charge transporting substances having electron transporting ability, JP-A-1-206349 proposes a compound having a diphenoquinone structure as a charge transporting agent for an electrophotographic photoreceptor.

[0005]

In the former prior art, an electron acceptor is blended as an acceptor for a charge generating agent, and the sensitivity is certainly increased by blending the electron acceptor. Because no transportation occurs,
There is a problem that the residual potential is still high.

On the other hand, the latter diphenoquinone derivative used in the prior art has a good compatibility with the binder resin and is said to exhibit a good electron transporting ability. The diphenoquinone derivative is used as a charge transporting layered photosensitive material. The body has a drawback that the residual potential is still high and the sensitivity in practical use is not sufficient.

On the other hand, regarding the charging polarity of the photoconductor,
If it can be used for both positive charging and negative charging, the range of application of the photoconductor can be further widened, and it is extremely advantageous in that various drawbacks described above can be eliminated. Further, if the organic photoreceptor can be used in a single layer dispersion type, many advantages are achieved in terms of facilitating the production of the photoreceptor, preventing the occurrence of coating defects, and improving the optical characteristics.

The inventors of the present invention selected a benzoquinone derivative having a reduction potential of -0.8 V to -1.3 V as an electron transfer agent, combined it with a hole transfer agent, and put it in a resin medium together with a charge generating agent. It has been found that, when dispersed into a single-layer dispersion type organic photoconductor, the residual potential of the photoconductor can be lowered and the sensitivity can be improved.

An object of the present invention is to provide an organic photoconductor for electrophotography, which is of a single-layer dispersion type and has a residual potential suppressed to a low level and excellent sensitivity. Another object of the present invention is to provide an organic photoreceptor which can be positively charged or both charged and which is particularly useful for digital electrophotography.

[0010]

According to the present invention, in an electrophotographic organic photoreceptor having an organic photosensitive layer on a conductive substrate, a charge generating agent in which the organic photosensitive layer is dispersed in a resin medium, The reduction potential as a hole transfer material and an electron transfer material is −
Provided is an organophotoreceptor, which is a composition comprising a 0.8V to -1.3V benzoquinone derivative. The organic photoconductor used in the present invention is preferably the one represented by the above-mentioned "Chemical formula 1". Further, the charge generating agent used in the present invention is preferably one having an ionization potential of 5.3 to 5.6 eV, particularly X-type metal-free phthalocyanine, and the hole transporting agent which matches this, A compound having an ionization potential of 5.3 to 5.6 eV, particularly an alkyl-substituted triphenyldiamine derivative is preferable.

[0011]

According to the present invention, the electron transfer agent has a reduction potential (measurement is carried out by the method described in Examples below).
Select a benzoquinone derivative of 0.8V to -1.3V,
When this is combined with a hole transport material and dispersed in a resin soot together with a charge generating agent to form a single-layer dispersion type organic photoreceptor, the residual potential of the photoreceptor can be lowered and the sensitivity can be improved.

According to the research conducted by the present inventors, both the reduction potential of the benzoquinone derivative and the potential contrast of the photoconductor (the difference between the potential of the unexposed portion and the residual potential of the exposed portion affect both the sensitivity and the residual potential). It has been found that a benzoquinone derivative having a constant reduction potential in a certain range can remarkably improve the potential contrast of the photoconductor in combination with each of the above components.

FIG. 1 shows a benzoquinone derivative of a single-layer dispersion type organic photoconductor containing a charge generating agent, a hole transporting agent, and various benzoquinone derivatives in a resin in a fixed amount ratio (for details, refer to Examples described later). Is a plot of the relationship between the reduction potential and the potential contrast of the photoconductor. By selecting a benzoquinone derivative having a reduction potential within the range of the present invention, the potential contrast is remarkably improved, that is, the sensitivity and the residual potential are increased. It is understood that the reduction of

The benzoquinone derivative used in the present invention is known as an electron-accepting substance, but the fact that a benzoquinone derivative having a reduction potential in the above range carries out electron transport was first discovered by the present invention. ..

Referring to FIG. 2 for explaining the principle of charge image generation in the electrophotographic organic photoreceptor of the present invention, a monolayer-dispersed organic photoreceptor layer 2 is provided on a conductive substrate 1.
In this organic photoreceptor layer 2, a charge generating agent CG, an electron transfer agent ET composed of a benzoquinone derivative and a hole transfer agent HT are dispersed. By the charging process prior to the exposure, the surface of the organic photoconductor layer 2 is positively (+) charged and the surface of the conductive substrate is negatively charged (-). When a light ray (hν) is irradiated in this state, an electric charge is generated in the charge generation agent CG, electrons are injected into the electron transfer agent ET, move to the surface of the organic photoconductor layer 2, and a positive charge (+) is generated. Cancel. On the other hand, the holes (+) are injected into the hole transport material HT, move to the surface of the conductive substrate 1 without being trapped in the middle, and are canceled by the negative charge (−). As described above, the charge image is generated.

The reason why the benzoquinone derivative having a reduction potential of -0.8 V to -1.3 V is used as the electron transporting agent ET in the present invention is that this is excellent in electron transporting property. Is a quinone-based oxygen atom with excellent electron-accepting properties bound to both terminals of the molecular skeleton, and also has a conjugated double bond throughout the molecular chain, which facilitates the transfer of electrons within the structure and the transfer of electrons. Seems to be related to being done easily. Furthermore, the reduction potential is −0.
If it is out of the range of 8V to -1.3V, it is difficult to inject the electrons (carriers) generated by the charge generating agent, whereas in the derivative having the reduction potential of -0.8V to -1.3V, the injection of electrons is difficult. It is recognized that

On the other hand, as a charge transport material, a hole transport material HT
In a system in which the and the electron transfer agent ET coexist, it is necessary to pay attention to the interaction between the two and more specifically to the formation of the charge transfer complex. When such a complex is formed between the two,
Recombination occurs between holes and electrons, and the charge mobility as a whole decreases. When the ionization potential of the hole transfer material HT is smaller than the range of the present invention, the electron transfer material E
Since the tendency to form a complex with T increases and electron-hole recombination occurs, the apparent quantum yield decreases,
It is thought to lead to a decrease in sensitivity.

In the present invention, it is particularly desirable to use the benzoquinone derivative of "Chemical Formula 1" as the electron transfer agent. First, the introduction of an electron-donating substituent brings about the effect of keeping the electron affinity of this derivative within the scope of the present invention. Incidentally, the reduction potential of the halogen-substituted benzoquinone derivative having an electron-withdrawing group introduced is on the order of -0.6 to -0.2V. Secondly, benzoquinone has a problem that it has a low solubility in a solvent used for forming a photosensitive layer and a low compatibility with a resin as a photosensitive layer medium. By introducing a substituent, preferably by making the method of introduction asymmetric, by improving the solubility in a solvent and the compatibility with a resin medium, by dispersing a high concentration of the electron transfer agent, The electron transport property can be improved. Thirdly, by introducing a substituent, especially a sublime substituent, into benzoquinones,
Steric hindrance is imparted to this derivative, the tendency of complex formation with the hole transport material HT is suppressed, and sensitivity can be improved.

In the present invention, the charge generating agent has an ionization potential of 5.3 to 5.6 eV, particularly 5.
A compound having a dose of 32 to 5.38 eV is used, but it is preferable in terms of suppressing the residual potential and improving the sensitivity, and as the hole transferring material, a material having an ionization potential balanced with the charge generating agent is preferable. That is, the ease with which the charge is injected from the charge generating agent CG to the hole transporting agent HT depends on the charge generating agent C.
G, which is closely related to the ionization potential of the hole transfer material HT, and when the ionization potential of CG or HT is larger than the range of the present invention, injection of charges from the charge generation material CG to the hole transfer material HT. It is recognized that the sensitivity is lowered due to the decrease in the number of holes or the degree of transfer of holes between the hole transport materials HT.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The electron transporting material used in the present invention is a benzoquinone derivative having a reduction potential in the range of -0.8 V to -1.3 V, and is particularly one represented by the above "Chemical formula 1". In "Chemical formula 1," the electron-donating group is an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group;
Aryl groups such as phenyl group, tolyl group, cumyl group; alkoxy groups such as methoxy group, ethoxy group, propoxy group;
Examples thereof include amino groups such as dimethylamino group and diethylamino group; however, the present invention is not limited thereto.

The number of substituents is 1 or more, preferably 2 to 4, and two of R1 and R2 are substituents,
Two of R1 and R3 being substituents, R1 and R4
2 are the substituents, three of R1, R2 and R3 are the substituents, and all of R1, R2, R3 and R4 are the substituents.

Examples of suitable derivatives are: 2,6-Dimethyl-p-benzoquinone 2,6-ditert-butyl-p-benzoquinone 1-methyl-p-benzoquinone 1-methoxy-p-benzoquinone p-benzoquinone tetramethyl-p-benzoquinone

As the hole-transporting agent, any hole-transporting substance can be used as long as the above-mentioned conditions are satisfied. Examples thereof include oxadiazole compounds, styryl compounds, carbazole compounds, organic polysilane compounds, pyrazoline compounds,
Hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds,
Of the nitrogen-containing reduction-type compounds such as triazole-based compounds and the condensed poly-reduction-type compounds, the ionization potential is 5.3 to 5.
A 6 eV one is used. In addition, the electric field strength 3 × 10
^- at ⁵ V / cm 10 ^- particularly good those having ⁶ Vcm or more mobility.

Suitable hole transport agents include, but are not limited to, 1,1-bis (p-diethylaminophenyl)-
4,4 diphenyl-1,3-butadiene, N, N'-bis (o, p-dimethylphenyl) -N, N'-diphenylbenzidine, 3,3'-dimethyl-N, N, N ',
N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-diamine, N-ethyl-3-carbazolylaldehyde-N, N'-diphenylhydrazone, 4- [N, N -Bis (p-toluyl) amino] -β
-Phenylstilbene and the like.

Examples of the charge generating agent include selenium, selenium-tellurium, amorphous silicon, pyrylium salt,
Azo pigments, disazo pigments, ansanthuron pigments,
Examples include phthalocyanine pigments, indico pigments, slene pigments, toluidine pigments, pyrazoline pigments, perylene pigments, quinacridone pigments, etc. Used. Ionization potential is 5.3 to 5.6
The following are exemplified as particularly preferable ones. X-type metal-free phthalocyanine, oxotitanyl phthalocyanine.

Various resins can be used as the resin medium in which the above-mentioned respective agents are dispersed. For example, a styrene-based polymer, an acrylic-based polymer, a styrene-acrylic-based polymer, an ethylene-vinyl acetate copolymer. ,polypropylene,
Olefin-based polymers such as ionomers, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyesters,
Alkyd resin, polyamide, polyurethane, epoxy resin, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin,
Examples include various polymers such as a phenol resin and a photocurable resin such as epoxy acrylate. These binder resins may be used alone or in combination of two or more.
Suitable resins include styrene polymers, acrylic polymers,
Examples thereof include styrene-acrylic polymer, polyester, alkyd resin, polycarbonate, polyarylate and the like.

In the photoreceptor of the present invention, the charge generating agent is 0.1 to 5% by weight, preferably 0.25 to 2.
The benzoquinone derivative (ET) may be contained in the photosensitive layer in an amount of 5% by weight, and the benzoquinone derivative (ET) may be contained in an amount of 5 to 50% by solid content.
% By weight, especially 10 to 40% by weight, while the hole transporting agent (H
T) is preferably contained in the photosensitive layer in an amount of 5 to 50% by weight, particularly 10 to 40% by weight, based on the solid content. Further, the ET: HT weight ratio is best in the range of 1: 9 to 9: 1, especially 2: 8 to 8: 2.

The composition for forming a photoreceptor of the present invention contains various compounding agents known per se, such as an antioxidant and a radical scavenger, as long as the electrophotographic properties are not adversely affected.
Singlet quencher, UV absorber, softener, surface modifier, defoamer, extender, thickener, dispersion stabilizer, wax,
An acceptor, a donor, etc. can be blended.

According to the present invention, when the sterically hindered phenolic antioxidant is added in an amount of 0.1 to 50% by weight based on the total solid content, the durability of the photosensitive layer is not adversely affected without adversely affecting the electrophotographic characteristics. It has been found that can be significantly improved. Suitable antioxidants are as follows: 2,6-di t
-Butyl-p-cresol;

[0030]

[Chemical 2]

[0031]

[Chemical 3]

[0032]

[Chemical 4]

[0033]

[Chemical 5]

[0034]

[Chemical 6]

[0035]

[Chemical 7]

[0036]

[Chemical 8]

As the solvent used for forming the coating liquid, various organic solvents can be used, and alcohols such as methanol, ethanol, isopropanol and butanol,
Aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride and chlorobenzene, dimethyl ether, diethyl ether, tetrahydrofuran, Ethylene glycol dimethyl ether, ethers such as diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, esters such as methyl acetate, dimethylformamide, dimethylsulfoxide, etc., various solvents are exemplified, and one or more kinds Used as a mixture. Generally, the solid content concentration of the coating liquid is preferably 5 to 50%.

As the conductive substrate, various conductive materials can be used. For example, aluminum, copper, tin, platinum, gold, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, indium, stainless steel. ,
Examples include simple metals such as brass, plastic materials in which the above metals are vapor-deposited or laminated, and glass covered with aluminum iodide, tin oxide, indium oxide, or the like.

The photoconductor of the present invention is a monolayer dispersion type photoconductor, and since it does not generate interference fringes or the like, it is alumite-treated so that the thickness of the ordinary aluminum tube is 1 to 50 μm. One of the advantages is that the applied blank tube can be used. Incidentally, in order to form the coating liquid, a charge generating material and the like and a binder resin and the like are prepared by a conventionally known method such as a roll mill,
It may be prepared by using a ball mill, an attritor, a paint shaker, an ultrasonic disperser, or the like, coated by a conventionally known coating means, and dried. The thickness of the photosensitive layer is not particularly limited, but is generally 5 to 100 μm, and particularly 10 to 5
It is desirable to be in the range of 0 μm.

[0040]

EXAMPLES The present invention will be described in more detail based on the following examples. Charge Generating Agent I: X-type Free Metal Phthalocyanine (Ip = 5.38)
eV) II: oxotitanyl phthalocyanine (Ip = 5.32e)
V) III: 1,4-dithioketo-3,6-diphenyl-pyrrolo- [3,4-C] pyrrolopyrrole (Ip = 5.46e
V) IV: N, N-bis (3,5-dimethylphenyl) -perylene-3,4,9,10-tetracarboxyldiimide (Ip = 5.60 eV) hole transport agent 4Me-TPD 6Me-TPD electron transport Agent a: tetrachloro-p-benzoquinone (reduction potential
-0.30 V) b: tetrabromo-p-benzoquinone (reduction potential
-0.30 V) c: 2,5-dichloro-p-benzoquinone (reduction potential
-0.51V) d: 2,6-dichloro-p-benzoquinone (reduction potential
-0.51V) e: p-benzoquinone (reduction potential
-0.81V) f: tetramethyl-p-benzoquinone (reduction potential
-1.20 V) g: 2,6-di-tert-butyl-p-benzoquinone (reduction potential -1.30 V)

Method for measuring reduction potential As a measuring solution, 0.1 mol of electrolyte (tert-butylammonium perchlorate), a substance to be measured (each electron transfer agent)
0.1 mol and 1 liter of solvent (dichloromethane) were mixed to prepare a three-electrode type [working electrode / glassy carbon electrode, counter electrode / platinum electrode, reference electrode / silver-silver nitrate electrode (0.1 mo
1 / L AgNO ₃ -acetonitrile solution)] was measured by cyclic voltammetry, and the redox potential was determined from the obtained measurement data.

Examples 1 to 3 and Comparative Examples 1 to 4 1 part by weight of the compound shown in Table 1 as a charge generating agent, 70 parts by weight of the compound shown in Table 1 as a hole transferring material, and Table 1 as an electron transferring material. 30 parts by weight of a benzoquinone derivative, 100 parts by weight of polycarbonate as a binder and a predetermined amount of dichloromethane as a solvent were mixed and dispersed by a ball mill to prepare a single layer type photosensitive layer coating solution, and the prepared solution was coated on an aluminum foil with a wire bar. After coating, 60 at 60 ℃
A single-layer type electrophotographic photoreceptor having a film thickness of 15 to 20 μm was produced by drying with hot air for a minute.

Comparative Example 5 A photoconductor was prepared in the same manner as in Examples 1 to 3 without adding an electron transfer agent.

Examples 4 to 5 and Comparative Example 6 The electrophotographic photoconductors obtained in Examples 1 to 3 and Comparative Example 5 were evaluated by negative charging.

Examples 6 to 9 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that the charge generating agent was 5 parts by weight.

Examples 10 to 12 Photosensitive members were prepared in the same manner as in Examples 1 to 3 except that the charge generating agent was changed to 10 parts by weight.

Examples 13 to 15 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that 10 parts by weight of the hole transfer material was used.

Examples 16 to 18 Photosensitive members were prepared in the same manner as in Examples 1 to 3 except that the amount of the hole transfer material was 80 parts by weight.

Examples 19 to 21 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that the electron transfer agent was changed to 10 parts by weight.

Examples 22 to 24 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that 50 parts by weight of the electron transfer agent was used.

Examples 25 to 27 Photosensitive members were prepared in the same manner as in Examples 1 to 3 except that the film thickness of the photosensitive member was 10 μm.

Examples 28 to 30 Photosensitive members were prepared in the same manner as in Examples 1 to 3 except that the film thickness of the photosensitive member was 30 μm.

Examples 31 to 33 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that the compounds shown in Table 2 were used instead of the hole transfer agent.

Examples 34 to 42 Photoreceptors were prepared in the same manner as in Examples 1 to 3 except that the compounds shown in Table 2 were used as the charge generating agent.

Evaluation of Electrophotographic Photosensitive Member Electrostatic copying tester (EPA-8100, manufactured by Kawaguchi Electric Co., Ltd.)
By applying an applied voltage to the photoconductor obtained in each of the examples to charge it positively or negatively, and the electrophotographic characteristics were measured using white halogen light as a light source. The results are shown in Tables 1 and 2. Indicated. V1 in the table indicates the initial surface potential of the photoconductor when the photoconductor is charged by applying a voltage, and V2
Is measured as the residual potential after 1 second has elapsed from the start of exposure, and the contrast potential is the difference between V1 and V2.

[0056]

[Table 1]

[0057]

[Table 2]

As is clear from Tables 1 and 2, the electrophotographic photoreceptor of the present invention containing a benzoquinone derivative having a reduction potential in the range of -0.8 V to -1.8 V as an electron transfer agent has a reduced residual potential. It was something that was done. On the contrary,
The electrophotographic photoreceptors of Comparative Examples 1 to 4 containing a benzoquinone derivative having a reduction potential outside the range of −0.8 V to −1.8 V and the electrophotographic photoreceptors of Comparative Examples 5 to 6 not containing a benzoquinone derivative, The residual potential was increased.

[0059]

According to the present invention, a benzoquinone derivative having a reduction potential of -0.8 V to -1.3 V is selected as an electron transfer agent, and this is combined with a hole transfer agent, and is combined with a charge generating agent in a resin medium. It was possible to lower the residual potential of the photoconductor and improve the sensitivity by dispersing it into a single layer dispersion type organic photoconductor. This photoreceptor can be used for positive charging and dual charging, and is particularly useful for digital electrophotography.

[Brief description of drawings]

FIG. 1 is a graph plotting the relationship between the reduction potential of benzoquinones and the residual potential contrast of a monolayer dispersion type organic photoconductor containing a charge generating agent, a hole transporting agent and various benzoquinones in a fixed amount ratio.

FIG. 2 is a diagram showing an organic photoconductor for electrophotography of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 2 Organic Photoreceptor Layer CG Charge Generating Agent HT Hole Transporting Agent ET Electron Transporting Agent

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03G 5/06 372 8305-2H

Claims (7)

[Claims] 1. An organic photoreceptor for electrophotography comprising an organic photosensitive layer on a conductive substrate, wherein the organic photosensitive layer is dispersed in a resin medium as a charge generating agent, a hole transfer agent and an electron transfer agent. An organophotoreceptor which is a composition comprising a benzoquinone derivative having a potential of -0.8 to -1.3V. 2. A benzoquinone derivative is represented by the formula: In the formula, R1, R2, R3 and R4 are compounds represented by hydrogen atom or electron donating group under the condition that at least one is electron donating group such as alkyl group, alkoxy group or amino group. The organic photoreceptor according to claim 1. 3. The charge generating agent is a charge generating agent having an ionization potential of 5.3 to 5.6 eV.
The organic photoreceptor described. 4. The organophotoreceptor according to claim 1, wherein the charge generating agent is an X-type metal-free phthalocyanine. 5. The hole transferring material is a hole transferring material having an ionization potential of 5.3 to 5.6 eV.
The organic photoreceptor described. 6. The organophotoreceptor according to claim 1, wherein the hole transporting agent is an alkyl-substituted triphenyldiamine derivative. 7. The charge generating agent is present in an amount of 1.0 to 10% by weight, the hole transfer agent is in an amount of 10 to 80% by weight, and the electron transfer agent is in an amount of 10 to 40% by weight, based on the binder resin. 1. The organic photoreceptor according to 1.