JP2000221710A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of a photoreceptor by light and to improve durability for repeated use and durability against environmental changes by incorporating a compd. having at least one specified structural unit into a photosensitive layer. SOLUTION: A base coating layer is formed on a conductive supporting body, and a photosensitive layer is laminated thereon. The photosensitive layer contains a compd. having at least one structural unit expressed by the formula. When the photosensitive layer is a laminated type having a charge producing layer and a charge transfer layer, the compd. is incorporated into the charge transfer layer. The content of the compd. is preferably 0.001 to 10 wt.%, more preferably 0.01 to 10 wt.% in the photosensitive layer. By incorporating the aforementioned compd., deterioration of the photoreceptor by light in an electrophotographic device can be prevented. Further, additives such as antioxidant and a preventing agent against deterioration by light can be added to the photosensitive layer so as to prevent deterioration of the photoreceptor due to ozone, acidic gas or light produced in a electrophotographic device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoreceptor for organic electrophotography (hereinafter also referred to as "photoreceptor").
The present invention relates to a photoconductor for organic electrophotography according to an improvement of an additive.

[0002]

2. Description of the Related Art In an electrophotographic system based on the invention of Carlson, the surface of an electrophotographic photosensitive member is charged, an electrostatic latent image is formed by exposure, and the latent image is developed with toner (visible image). The visible image is transferred to paper. The photoreceptor then removes any residual toner attached,
After static elimination, it is repeatedly used from the exposure step. The characteristics required for such a photoreceptor include a charging characteristic, a charge holding characteristic in a dark place, and a charge dissipating property (sensitivity) upon light irradiation.
Is required to have good durability, durability in repeated use over a long period of time, and resistance to environmental changes during use. As a material used for such a photoconductor, conventionally, selenium, a selenium alloy,
Many used inorganic photoconductive materials such as zinc oxide and cadmium sulfide.

Recently, photosensitive materials using organic photoconductive materials have been used, taking advantage of advantages such as low toxicity, transparency, film formability, light weight, and productivity, as compared with inorganic photosensitive materials. The development of the body is actively pursued. Such electrophotographic photoconductors are generally classified into a single-layer type and a multilayer type, and each has a unique advantage.

A single-layer type organic photoreceptor having a charge generation layer and a charge transport layer in the same layer is generally a positively charged type photoreceptor which positively charges a surface potential. This photoreceptor has the advantage that it generates less ozone, which is harmful during use, and is environmentally friendly. Further, in the function-separated laminated organic photoreceptor in which the charge generation layer and the charge transport layer are separated from each other, the sensitivity can be significantly improved by forming each layer with a material optimal for each function and combining them. In addition, there are many advantages such as the ability to set the spectral sensitivity according to the desired wavelength of the exposure light. All of these are widely used in electrophotographic devices such as copiers, printers and fax machines, taking advantage of their respective advantages.

[0005] Further, as conventional problems, repelling, bumping, unevenness, etc. occur due to very small defects, dirt deposits, scratches, etc. on the conductive support, and uneven charge injection from the support. However, there are drawbacks such as white spots appearing on the image. Therefore, in order to improve them, a layer of alumite or the like generally called an undercoat layer is often provided. Many of the function-separated and laminated organic photoconductors currently in practical use are formed by laminating an undercoat layer, a charge generation layer, and a charge transport layer on a conductive support in this order.

[0006]

On the other hand, extending the life of the photoconductor is important from the viewpoint of energy saving.
Above all, to improve the durability when used repeatedly and the resistance to environmental changes, that is, to prevent the deterioration of the photoreceptor due to ozone, oxidizing gas, light or heat generated in the electrophotographic apparatus Is an important issue in the development of photoreceptors. Until now, various antioxidants, light deterioration inhibitors, heat stabilizers and the like have been proposed, but none of them having a sufficient effect has yet been obtained.

Accordingly, an object of the present invention is to focus on the photo-deterioration inhibitor among the above-mentioned additives, and to improve the photo-deterioration inhibitor to be added to the photosensitive layer, so that the photoreceptor of the photoreceptor can be used in an electrophotographic apparatus. An object of the present invention is to provide an electrophotographic photoreceptor which prevents deterioration and has improved durability upon repeated use and improved resistance to environmental changes.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, a compound having a basic skeleton represented by the following structural formula (I) was incorporated into a photosensitive layer. It has been found that the addition improves the repetition durability and environmental durability, and the present invention has been completed.

That is, the electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support. Formula (I), Or a compound having at least one structural unit represented by the formula:

In the electrophotographic photoreceptor of the present invention, the photosensitive layer is composed of a single layer, or the photosensitive layer is composed of a function-separated laminate of a charge generation layer and a charge transport layer. It contains a compound having at least one structural unit represented by the formula (I). The photosensitive layer preferably contains 0.001 to 10% by weight of the compound.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a conceptual cross-sectional view of an example of a function-separated laminated electrophotographic photoconductor of the present invention.
An undercoat layer 2 is provided on a conductive support 1, and a photosensitive layer 5 composed of a charge generation layer 3 and a charge transport layer 4 is further laminated thereon in that order. FIG. 2 is a conceptual cross-sectional view of another example of a single-layer type electrophotographic photoreceptor of the present invention, in which an undercoat layer 2 is provided on a conductive support 1, and a photosensitive layer 5 is provided thereon. Are laminated.

The conductive support 1 serves not only as an electrode of the photoreceptor but also as a support for other layers, and may be any of a cylinder, a plate, and a film. In addition to metals such as iron, a support made of plastic or the like that has been made conductive by depositing a metal on the surface or forming a coating film in which conductive powder is dispersed can be used.

An undercoat layer 2 may be formed on the surface of the conductive support 1 if necessary. The undercoat layer 2 is formed of polyvinyl alcohol resin, polyamide resin, polyurethane resin, melamine resin, epoxy resin or phenol resin, aluminum oxide, or the like.

On the undercoat layer 2, a photosensitive layer 5 is formed. As shown in FIGS. 1 and 2, the photosensitive layer 5 has a function-separated multi-layer structure composed of two layers, that is, a charge generation layer 3 and a charge transport layer 4, and a single layer without separation. Although there is a single-layer type, any of them can be applied in the present invention.

The charge generating layer 3 is formed by forming a charge generating substance by vacuum evaporation or dispersing the charge generating substance in an organic solvent together with a binder resin.
It is formed by coating. As the charge generation material, amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, inorganic photoconductors such as zinc oxide and titanium oxide,
Azo dyes such as chlorodiane blue, anthantrone, quinone pigments such as pyrenequinone, quincyanine pigments,
Perylene pigments, perinone pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments such as metal-free phthalocyanines, titanyl phthalocyanines, tin phthalocyanines, gallium phthalocyanines, copper phthalocyanines, vanadyl phthalocyanines, azulhenium salts, squarium pigments, quinacridone pigments, azo pigments, Various organic pigments and dyes such as anthroquinone pigment, pyrene pigment, pyrylium salt, and thiapyrylium salt are used. In addition, these organic pigments generally have several types of crystal forms, and in particular, phthalocyanine pigments are known to have various crystal types such as α, β, etc. If so, any crystal type may be used.

As the binder resin in the charge generation layer 3,
Melamine resin, epoxy resin, silicone resin, polyurethane resin, acrylic resin, polycarbonate resin, polyarylate resin, phenoxy resin, polyester resin,
Polyvinyl butyral resin, methacrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin and copolymer resin containing two or more of these repeating units, for example, vinyl chloride-vinyl acetate copolymer resin, acrylonitrile-styrene copolymer Insulating resins such as polymer resins can be used, but all commonly used resins can be used alone or in combination of two or more.

The charge transport material of the charge transport layer 4 provided on the charge generation layer 3 includes hydrazone compounds, pyrazoline compounds, triphenylamine compounds, triphenylmethane compounds, stilbene compounds, oxadiazoles. Compounds, enamine compounds, triazine compounds, quinazoline compounds, benzofuran compounds, carbazole compounds, quinone compounds, fluorenone compounds, and xanthone compounds can be used. Two or more can be used in combination.

The binder resin used for the charge transport layer 4 includes acrylic resin, polyarylate, polyester resin, polycarbonate resin, polystyrene resin, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, and polyvinyl formal. And insulating resins such as polysulfone, polyacrylamide, polyamide, and chlorinated rubber; and organic photoconductive polymers such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene.

The charge transport layer 4 can be formed by applying and drying a solution obtained by dissolving the above-described charge transport material and binder resin in an appropriate solvent. Examples of the solvent used for forming the charge transport layer 4 include toluene,
Aromatic hydrocarbons such as xylene, halogenated aliphatic hydrocarbons such as methylene chloride, monochlorobenzene, and chloroform; ketones such as acetone and 2-butanone; and cyclic or straight-chain compounds such as tetrahydrofuran, dioxane, ethylene glycol, and diethyl ether. A chain ether or a mixed solvent thereof can be used.

The photosensitive layer 5 in the single-layer type photosensitive member is
It is formed by dispersing a charge generating substance together with a binder resin in an organic solvent, further mixing and applying a charge transporting substance. As the charge generating material and the charge transporting material of the photosensitive layer 5, the same materials as those used for the charge generating layer 3 and the charge transporting layer 4 can be used, and as the binder resin, the charge generating layer 3 and the charge transporting material can be used. As in the case of the charge transport layer 4, the above resins and all commonly used resins can be used alone or in combination of two or more.

The photosensitive layer 5 is coated and dried by mixing a charge transporting substance or a solution in which the charge transporting substance is dissolved with a dispersion obtained by dispersing the charge generating substance and the binder resin in an appropriate solvent. Can be formed. Examples of the solvent used for forming the photosensitive layer include aromatic hydrocarbons such as toluene and xylene; halogenated aliphatic hydrocarbons such as methylene chloride, monochlorobenzene and chloroform; ketones such as acetone and 2-butanone; Tetrahydrofuran, dioxane, ethylene glycol,
A cyclic or linear ether such as diethyl ether, or a mixed solvent thereof can be used.

The photosensitive layer 5 in the present invention has the following general formula (I): A compound having at least one structural unit represented by the formula: In the case where the photosensitive layer 5 is a laminated type of the charge generation layer 3 and the charge transport layer 4, the compound is contained in the charge transport layer.
The content of the compound in the photosensitive layer is preferably 0.001 to 10% by weight, more preferably 0.01 to 1% by weight.
It is within the range of 0% by weight. By including such a compound in the photosensitive layer, deterioration of the photosensitive member due to light in an electrophotographic apparatus can be prevented, and durability during repeated use and resistance to environmental changes can be improved.

Specific examples of the compound according to the present invention are shown below, but it should not be construed that the invention is limited thereto.

[0024]

[0025]

[0026]

The photosensitive layer 5 contains an antioxidant other than the compound according to the present invention for the purpose of preventing deterioration of the photosensitive member due to ozone or oxidizing gas generated in the electrophotographic apparatus, or light or heat. Additives such as a light deterioration inhibitor and a heat stabilizer can also be added. The coating can be performed by using a coating method such as a dip coating method, a spray coating method, a ring coating method, a bead coating method, a blade coating method, and a roller coating method.

[0028]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. Example 1 On a 30 mm × 30 mm × 1 mm aluminum conductive support, 1.5 parts by weight of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) as an undercoat layer were 50 parts by weight of methanol and 50 parts by weight of methylene chloride. A solution prepared by dissolving in a part by weight of the mixed solution was applied, and dried at 100 ° C. for 15 minutes to provide an undercoat layer having a thickness of 0.1 μm.

Next, 10 parts by weight of an X-type metal-free phthalocyanine as a charge generating substance, and 10 parts by weight of a polyvinyl butyral resin (trade name: ESLEC BM-2, manufactured by Sekisui Chemical Co., Ltd.) as a binder resin , Cyclohexanone 1
00 parts by weight was subjected to a dispersion treatment for 7 hours with a sand grinder using 0.25 mm zirconia balls as a spherical fine pulverizing medium. This dispersion was diluted by adding 600 parts by weight of tetrahydrofuran, and dip-coated on the undercoat layer.
Drying was performed at 30 ° C. for 30 minutes to provide a charge generation layer having a thickness of 0.3 μm.

Next, in providing the charge transport layer on the charge generation layer, compounds represented by the following structural formulas (1) and (2) were used as the charge transport material.

5 parts by weight of the compound (1), 5 parts by weight of the compound (2), and polycarbonate as a binder resin (trade name: PCZ-300, molecular weight 30,000, manufactured by Mitsubishi Gas Chemical Co., Ltd.) 10 parts by weight, 0.1 part by weight of dibutylhydroxytoluene (BHT) and the above specific example (I
After dissolving 0.01 part by weight of the compound of -1) in 90 parts by weight of methylene chloride and dip-coating on the charge generating layer,
Drying was performed at 30 ° C. for 30 minutes to provide a charge transport layer having a thickness of 18 μm. In this way, a function-separated laminated electrophotographic photoconductor composed of three layers was produced.

Example 2 In Example 1, the above specific example (I-
A photoconductor was prepared in the same manner, except that 0.5 part by weight of the compound of 1) was added.

Example 3 On a 30 mm × 30 mm × 1 mm aluminum conductive support, 1.5 parts by weight of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) as an undercoat layer were mixed with 50 parts by weight of methanol and A solution dissolved in a mixed solution of 50 parts by weight of methylene chloride was applied by dip coating, and dried at 100 ° C. for 15 minutes to form an undercoat layer having a thickness of 0.2 μm.

Next, 10 parts by weight of an X-type metal-free phthalocyanine as a charge generating substance and a vinyl chloride-vinyl acetate copolymer (trade name: MR-110, manufactured by Zeon Corporation)
10 parts by weight and 100 parts by weight of cyclohexanone were subjected to a dispersion treatment for 7 hours by a sand grinder using 0.25 mm zirconia balls as a spherical pulverizing medium. This dispersion was diluted by adding 600 parts by weight of tetrahydrofuran, dip-coated on the undercoat layer, and dried at 100 ° C. for 30 minutes to provide a 0.3 μm-thick charge generation layer.

Next, in providing the charge transport layer on the charge generation layer, compounds represented by the following structural formulas (3) and (4) were used as the charge transport material.

5 parts by weight of the compound (3), 5 parts by weight of the compound (4), and 10 parts by weight of polycarbonate (trade name: Panlite L-1250, manufactured by Teijin Chemicals Ltd.) as a binder resin And a phenolic antioxidant (trade name: IRGANOX565, Nippon Ciba Geigy Co., Ltd.)
0.2 parts by weight) and 0.1 part by weight of the compound of the above specific example (I-8) were dissolved in 90 parts by weight of methylene chloride, and then applied by dip coating on the charge generation layer, and then at 100 ° C. for 30 minutes. After drying, a charge transport layer having a thickness of 20 μm was provided. In this way, a function-separated laminated electrophotographic photoconductor composed of three layers was produced.

Example 4 In Example 3, the above-mentioned specific example (I-
A photoconductor was prepared in the same manner, except that 0.5 part by weight of the compound of 8) was added.

Example 5 1.5 parts by weight of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) was used as an undercoat layer on a 30 mm × 30 mm × 1 mm aluminum conductive support. A solution dissolved in a mixed solution of 50 parts by weight of methylene chloride was applied by dip coating, and dried at 100 ° C. for 15 minutes to form an undercoat layer having a thickness of 0.1 μm.

Next, as a charge generating substance, the following structural formula (5): And a polyvinyl butyral resin as a binder resin (trade name: Eslek KS-5)
Z, manufactured by Sekisui Chemical Co., Ltd.) in an amount of 0.25 m
Dispersion treatment was performed for 7 hours with a sand grinder using m zirconia balls. To this dispersion was added methyl ethyl ketone 60
The mixture was diluted by adding 0 parts by weight, dip-coated on the undercoat layer, and dried at 100 ° C. for 30 minutes to provide a 0.3 μm-thick charge generation layer.

Next, as a charge transport material, the following structural formula (3) And a polycarbonate (trade name: PCZ-300, molecular weight 30) as a binder resin.
000, manufactured by Mitsubishi Gas Chemical Co., Ltd.), 10 parts by weight of dibutylhydroxytoluene (BHT), and 1 part by weight of the compound of the specific example (I-10) were dissolved in 90 parts by weight of methylene chloride. Then, after dip coating on the charge generation layer,
Drying was performed at 100 ° C. for 30 minutes to provide a charge transport layer having a thickness of 18 μm. In this way, a function-separated laminated electrophotographic photoconductor composed of three layers was produced.

Example 6 In Example 5, the above-mentioned specific example (I-1) was added to the charge transport layer.
A photoconductor was prepared in the same manner except that 5 parts by weight of the compound (0) was added.

Comparative Example 1 In Example 1, the above-mentioned specific example (I-
A photoconductor was prepared in the same manner except that the compound of 1) was not added.

COMPARATIVE EXAMPLE 2 In Example 3, the above-mentioned specific example (I-
A photoconductor was prepared in the same manner except that the compound of 8) was not added.

Comparative Example 3 In Example 5, the specific example (I-1) was added to the charge transport layer.
A photoconductor was prepared in the same manner except that the compound of 0) was not added.

Example 7 An X-type metal-free phthalocyanine (10 parts by weight) as a charge generating material and a polyvinyl butyral resin as a binder resin (trade name: Eslec BM-2, Sekisui Chemical Co., Ltd.)
10 parts by weight) and 80 parts by weight of tetrahydrofuran were subjected to a dispersion treatment for 3 hours by a sand grinder using 0.5 mm zirconia balls as a spherical pulverizing medium. Also,
Separately, the compound (1) 1
5 parts by weight and 15 parts by weight of the same compound (2) were used, and these were added to a polycarbonate (trade name: P
CZ-300, molecular weight 30,000, Mitsubishi Gas Chemical Co., Ltd.
30 parts by weight and dibutylhydroxytoluene (BH
T) 0.5 part by weight of the compound 0.0 of the specific example (I-1)
1 part by weight and 200 parts by weight of tetrahydrofuran were dissolved and mixed with the dispersion. This mixture was subjected to ultrasonic dispersion for 10 minutes to obtain a coating liquid.

This coating solution was applied onto a 30 mm × 30 mm × 1 mm aluminum conductive support by dip coating, followed by drying at 100 ° C. for 120 minutes to provide a photosensitive layer having a thickness of 18 μm. Thus, a single-layer type electrophotographic photoreceptor was produced.

Example 8 In Example 7, the specific examples (I-
A photoconductor was prepared in the same manner, except that 0.5 part by weight of the compound of 1) was added.

Example 9 On a 30 mm × 30 mm × 1 mm aluminum conductive support, 1.5 parts by weight of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) as an undercoat layer were mixed with 50 parts by weight of methanol and A solution dissolved in a mixed solution of 50 parts by weight of methylene chloride was applied by dip coating, and dried at 100 ° C. for 15 minutes to form an undercoat layer having a thickness of 0.1 μm.

Next, 10 parts by weight of an X-type metal-free phthalocyanine as a charge generating substance and a vinyl chloride-vinyl acetate copolymer (trade name: MR-110, manufactured by Zeon Corporation)
10 parts by weight and 80 parts by weight of tetrahydrofuran were subjected to a dispersion treatment for 3 hours by a sand grinder using 0.5 mm zirconia balls as a spherical pulverizing medium. Separately, 15 parts by weight of the compound (3) and 15 parts by weight of the compound (4) were used as a charge transporting substance, and these were combined with a polycarbonate (trade name: Panlite L-1250; 30 parts by weight of Teijin Chemicals Ltd. and a phenolic antioxidant (trade name: IRGANOX)
565, manufactured by Nippon Ciba Geigy Co., Ltd.)
0.1 part by weight of the compound of the above specific example (I-8) was dissolved in 200 parts by weight of tetrahydrofuran, and mixed with the dispersion. This mixture was subjected to ultrasonic dispersion for 10 minutes to obtain a coating liquid. After dip coating this coating solution on the undercoat layer,
Drying was performed at 00 ° C. for 120 minutes to provide a charge transport layer having a thickness of 18 μm. Thus, a single-layer type electrophotographic photoreceptor was produced.

Example 10 In Example 3, the specific example (I-
A photoconductor was prepared in the same manner, except that 0.5 part by weight of the compound of 8) was added.

Comparative Example 4 In Example 7, the specific example (I-
A photoconductor was prepared in the same manner except that the compound of 1) was not added.

Comparative Example 5 In Example 9, the specific example (I-
A photoconductor was prepared in the same manner except that the compound of 8) was not added.

The evaluation of the photoreceptors prepared in Examples 1 to 4 and Comparative Examples 1 and 2 was conducted by using a fluorescent lamp of 1000 lux with 1 light.
The measurement was performed by measuring the electrical characteristics of the photoconductor before and after the irradiation for 0 minute. The measurement was carried out using an electrostatic charging tester EPA8100 (manufactured by Kawaguchi Electric Works) and measuring 20 watts on a tungsten wire.
The measurement was performed by a constant current method adjusted so that a current of μA flows, and the initial charge position was measured. Next, 7
Exposure was performed with monochromatic light of 80 nm, and the exposure amount (sensitivity) required for the surface potential to attenuate to half of the initial surface potential was determined.

This measurement was performed before, immediately after, after 30 minutes, and
After 3 hours and 24 hours, the results were compared. Table 1 below summarizes the results of the photoreceptors of Examples 1 to 4 and Comparative Examples 1 and 2 with respect to the type of photodeterioration inhibitor and the relationship between the amount of the inhibitor and the electrical characteristics. Show.

[0055]

[Table 1]

The photosensitive members produced in Examples 5 and 6 and Comparative Example 3 were evaluated by measuring the electrical characteristics of the photosensitive members before and after irradiation with light of a 1,000-lux fluorescent lamp for 10 minutes. The measurement was conducted using an electrostatic charging tester EPA8100.
(Kawaguchi Electric Manufacturing Co., Ltd.), the measurement was performed by a constant current method adjusted so that a current of 20 μA flows through the tungsten wire, and the initial charge position was measured. Then, illuminance 5lx
The exposure was performed with white light of s, and the exposure amount (sensitivity) required for the surface potential to attenuate to half of the initial surface potential was determined.

This measurement was carried out before, immediately after, after 30 minutes,
After 3 hours and 24 hours, the results were compared. Table 2 below summarizes the results of the photoreceptors of Examples 5 and 6 and Comparative Example 3 with respect to the type of photodeterioration inhibitor and the relationship between the amount of the inhibitor and the electrical characteristics.

[0058]

[Table 2]

Further, Examples 7 to 10 and Comparative Example 4,
Evaluation of the photoreceptor manufactured in 5 was performed by the same measurement as in Examples 1 to 4 and Comparative Examples 1 and 2. The results are shown in Table 3 below in Examples 7 to 10 and Comparative Examples 4 and 5, which summarize the relationship between the amount of the photodeterioration inhibitor and the electrical properties of the inhibitor.

[0060]

[Table 3]

As is clear from Tables 1, 2 and 3, the photoreceptor prepared by adding the compound of the present invention to the photosensitive layer has a remarkable effect on the recovery of the charged potential after light irradiation. I understood.

[0062]

According to the present invention, in an electrophotographic photosensitive member having a photosensitive layer containing at least a charge generating substance and a charge transporting substance on a conductive support, the photosensitive layer has the above-mentioned structural formula (I) By containing the compound having the structure represented by the formula (1), it is possible to prevent the photoreceptor from being deteriorated by light in an electrophotographic apparatus, and to improve the durability upon repeated use and the resistance to environmental changes.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view of an example of a function-separated stacked type electrophotographic photoconductor of the present invention.

FIG. 2 is a conceptual cross-sectional view of another example of a single-layer type electrophotographic photoreceptor of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 undercoat layer 3 charge generation layer 4 charge transport layer 5 photosensitive layer

Claims (4)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer containing a charge generating substance and a charge transporting substance on a conductive support, wherein the photosensitive layer has the following structural formula (I): An electrophotographic photoconductor, comprising a compound having at least one structural unit represented by the formula: 2. The electrophotographic photoreceptor according to claim 1, wherein said photosensitive layer comprises a single layer. 3. The photosensitive layer comprises a functional separation laminate of a charge generation layer and a charge transport layer, wherein the charge transport layer contains (I)
The electrophotographic photoconductor according to claim 1, further comprising a compound having at least one structural unit represented by the formula: 4. The electrophotographic photosensitive member according to claim 1, wherein the content of the compound is 0.001 to 10% by weight based on the photosensitive layer.