JPH1115176A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure sensitivity and to reduce variation of potential acceptance and residual potential due to repeated uses and to enhance preexposure characteristics by incorporating a metal salt of a specified carboxylic acid derivative in a charge transfer layer. SOLUTION: The charge transfer layer contains at least one of the carboxylic acid derivatives represented by the formula in which X is a -NHCO- or -SO2 NH- group; R is a divalent bonding group; and Ar is an optionally substituted aromatic or hetero-cyclic group. The preferable bonding direction of X is an Ar- NHCO- or Ar-SO2 NH- order, and R is a divalent bonding group and it is preferred for R to be an optionally substituted phenylene and alkylene groups, especially, 1,4-phenylene, 1,2-phenylene group and an optionally substituted <=5C alkylene group, and Ar is, preferably, optionally substituted phenyl and naphthyl group and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor having high sensitivity and excellent repetition stability and pre-exposure characteristics.

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2. Description of the Related Art Conventionally, as an electrophotographic photosensitive member,
Those having a photosensitive layer mainly containing an inorganic photoconductor such as selenium, cadmium sulfide, zinc oxide, and silicon have been widely known. However, these are sensitive, heat stable, moisture resistant,
It is not always satisfactory in durability and the like, and in particular, selenium and cadmium sulfide have restrictions in production and handling due to their toxicity.

On the other hand, an electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductive compound as a main component is relatively easy to manufacture, inexpensive, easy to handle,
In addition, it generally has many advantages such as superior thermal stability as compared with selenium photoreceptors, and has attracted much attention in recent years.

[0004] Among them, an electrophotographic photoreceptor in which a charge transfer layer containing a charge transfer material such as triphenylamines, stilbenes and hydrazones and a charge transfer layer containing a charge transfer material such as phthalocyanine pigment and azo pigment are laminated. Has been proposed and active research is being conducted. In this way, the function-separated electrophotographic photoreceptor of the stacked type, in which the charge generation function and the charge transfer function are respectively assigned to different substances, has a wide selection range of materials, and is excellent in charging characteristics, sensitivity, durability and the like. In addition, there is an advantage that an electrophotographic photosensitive member having arbitrary characteristics can be produced relatively easily.

[0005] However, only a few functionally-separated type photoconductors have been put to practical use, and electrical characteristics such as charging characteristics, sensitivity, residual potential, pre-exposure characteristics, and repetition characteristics, scratch resistance, and abrasion resistance. At present, it is difficult to say that all the required properties such as mechanical strength are satisfied.

Many attempts have been made to improve these electrical characteristics. For example, JP-A-3-78753 describes that it is effective to include a metal complex or a metal salt of a specific aromatic carboxylic acid in a charge transfer layer against an increase in residual potential due to repetition. Japanese Patent Application Laid-Open No. 4-296 discloses that it is effective to contain a zinc salt compound of an aliphatic carboxylic acid.
No. 867.

However, the metal complexes and metal salts of aromatic carboxylic acids and zinc salt compounds of aliphatic carboxylic acids described in the above-mentioned publications generally have low solubility in organic solvents, and are particularly suitable for forming various charge-generating layers. The solubility in materials such as dichloromethane, dichloroethane and other halogen-based solvents used for dissolving the materials, and tetrahydrofuran and cyclic ether-based solvents such as 1,3-dioxolane is poor, and the amount added is limited by the solubility. is there. In addition, not only the solubility in the solvent, but poor compatibility with the charge transfer material and the binder resin, it is deposited during coating and drying, or after forming a photoreceptor, and then separated and deposited by storage over time or repeated use, There is a problem of causing an image defect. Further, these compounds have a problem that pre-exposure characteristics are deteriorated because the light fatigue resistance of the photoreceptor is reduced.

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SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity, a small change in charge potential and residual potential due to repetition, and excellent pre-exposure characteristics.

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Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that an electron having at least a photosensitive layer comprising a charge generation layer and a charge transfer layer on a conductive support. In the photoreceptor, it has been found that it is effective to solve the above-mentioned problems if the charge transfer layer contains at least one metal salt of a carboxylic acid derivative represented by the following general formula (I). Was completed.

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In the formula (I), X represents —NHCO— or —SO ₂ NH—, R represents a divalent linking group,
r represents an aromatic ring residue or a heteroaromatic ring residue which may have a substituent.

The present invention specifically relates to an electrophotographic photoreceptor having a blocking layer provided on a conductive support, if necessary, and a photosensitive layer comprising at least a charge generation layer and a charge transfer layer thereon. An electrophotographic photoreceptor comprising the charge transfer layer containing at least one metal salt of a carboxylic acid derivative having excellent solubility in the organic solvent represented by the general formula (I).

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DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, each component of the electrophotographic photoreceptor of the present invention will be described in detail. The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having at least a photosensitive layer comprising a charge generation layer and a charge transfer layer on a conductive support, wherein the charge transfer layer is represented by the formula (I). An electrophotographic photosensitive member containing at least one metal salt of a carboxylic acid derivative to be produced.

The photosensitive layer comprises at least a charge generation layer and a charge transfer layer, and the order of lamination of the charge generation layer and the charge transfer layer is as follows.
Although the charge generation layer and the charge transfer layer may be arranged in this order from the side closest to the conductive support, the charge transfer layer and the charge generation layer may be arranged in this order. It is preferable to provide the layer and the charge transfer layer in this order.

The charge generating layer constituting the photosensitive layer contains at least a charge generating substance, and the charge generating substance alone or the charge generating substance and a binder resin are mixed and dispersed in a solvent.
It is formed by coating and drying.

Examples of the charge generating substance used in the charge generating layer include phthalocyanine pigments represented by metal phthalocyanine, metal-free phthalocyanine, etc .; naphthalocyanine pigments represented by metal naphthalocyanine, metal-free naphthalocyanine, etc .; perylene anhydride , Perylene pigments represented by perylene imide, anthraquinone derivatives, anthranthrone derivatives, dibenzopyrene quinone derivatives, pyranthrone derivatives, anthraquinone pigments represented by biolanthrone derivatives or polycyclic quinone pigments, monoazo pigments, bisazo pigments, trisazo pigments And the like, azo pigments, porphyrin pigments, quinacridone pigments and the like.

Of these, those using bisazo pigments, trisazo pigments, and phthalocyanine pigments are preferred because they have high carrier generation efficiency and provide a highly sensitive photoreceptor. For example, in the case of bisazo pigments, see
2-286058, JP-A-63-23163,
JP-A-63-32557, JP-A-63-89866, JP-A-63-243948, and JP-A-64-21453.
JP-A-64-21455, JP-A-1-200
No. 263, No. 1-202775, No. 1-20
Nos. 2575, 2-150855 and 4-9
Nos. 6068, 5-142841 and 6-3
Nos. 843, 6-27697, 6-277
No. 06 etc. can be used,
In the case of a phthalocyanine pigment, metal-free phthalocyanine, oxytitanium phthalocyanine, vanadyl phthalocyanine, chloroaluminum phthalocyanine,
Diphenoxygermanium phthalocyanine and the like can be used.

As the binder resin used for the charge generation layer, conventionally known styrene, vinyl acetate,
Vinyl chloride, acrylic acid esters, polymers and copolymers of vinyl compounds such as methacrylic acid esters, formal resins, acetal resins such as butyral resins, silicone resins, phenoxy resins, epoxy resins, urethane resins,
Examples include, but are not limited to, phenolic resins, polyamide resins, polyimide resins, polycarbonate resins, polyester resins, polyarylate resins, and the like.

The charge generation layer may be composed of the charge generation substance alone. When a binder resin is used together with the charge generation substance, the binder resin is used in an amount of 1 to 1000 parts by weight, preferably 1 to 1000 parts by weight, per 100 parts by weight of the charge generation substance. Used in the range of 400 parts by weight. The thickness of the charge generation layer is in the range of 0.05 to 20 μm, preferably 0.1 to 2 μm.

As the solvent used for forming the charge generating layer, 1,2-dimethoxyethane, tetrahydrofuran,
Ethers such as 1,4-dioxane and 1,3-dioxolane, methyl ethyl ketone, methyl isobutyl ketone,
Ketones such as diisobutyl ketone and cyclohexanone,
Aromatic hydrocarbons such as toluene and xylene, aprotic polar solvents such as N, N-dimethylformamide, acetonitrile, N-methylpyrrolidone and dimethylsulfoxide; alcohols such as methanol, ethanol and 2-propanol; methyl acetate; acetic acid Ethyl, propyl acetate,
Esters such as butyl acetate and methyl cellosolve acetate; halogenated hydrocarbons such as dichloroethane, dichloromethane and chloroform;

The charge transfer layer constituting the electrophotographic photoreceptor of the present invention contains at least a charge transfer substance and a binder resin, and contains at least one metal salt of a carboxylic acid derivative represented by the following general formula (I). Contains seeds.

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In the formula (I), X represents -NHCO- or -SO ₂ NH-, R represents a divalent linking group,
r represents an aromatic ring residue or a heteroaromatic ring residue which may have a substituent.

In the carboxylic acid derivative represented by the general formula (I), the bonding order of —NHCO— or —SO ₂ NH— is as follows from the Ar side: —NHCO—, —SO ₂ NH— or —CONH—, Although the order of —NHSO ₂ — may be used, in the present invention, the former bonding order is more preferable. R represents a divalent linking group, and is preferably a phenylene group or an alkylene group which may have a substituent, and particularly preferably a 1,4-phenylene group or 1,2.
-A phenylene group or an alkylene group having 5 or less carbon atoms which may have a substituent. Further, Ar represents an aromatic ring residue or a heteroaromatic ring residue which may have a substituent, and preferred examples thereof include a phenyl group which may have a substituent,
A naphthyl group and a thienyl group are particularly preferred, and a phenyl group which may have a substituent is particularly preferred. The substituent is preferably an alkyl group, an alkoxy group, a halogen atom, a cyano group, a trifluoromethyl group, a sulfamoyl group, an N-substituted sulfamoyl group, an N, N-disubstituted sulfamoyl group, and particularly preferably an alkyl group. Group,
An alkoxy group, a trifluoromethyl group, and an N, N-disubstituted sulfamoyl group.

Specific examples of the carboxylic acid derivative represented by the above general formula (I) used in the electrophotographic photoreceptor of the present invention are shown below, but are not limited thereto.

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The metal used in the present invention may be any metal as long as it can form a metal salt together with the above carboxylic acid derivative, but may be aluminum, zinc, chromium, cobalt, nickel, iron, Copper is preferred,
Among them, aluminum and nickel are particularly preferred. In the present invention, the metal salt is not limited to a salt based on ionic bonds, and may be a metal complex.

The metal salt of the carboxylic acid derivative is added in an amount of 0.01 to 10 parts by weight, more preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the charge transfer material. Range.

Next, specific examples of the method for producing the carboxylic acid derivative will be described, but the method is not limited thereto.

Synthesis Example 1 Synthesis of exemplified compound (AD1-32). In a flask equipped with a stirrer and a calcium chloride drying tube, 14.8 parts by weight of phthalic anhydride and triethylamine 1 were added.
1.2 parts by weight and 100 parts by weight of tetrahydrofuran (THF) were charged, and a solution prepared by dissolving 12.4 parts by weight of o-anisidine in 50 parts by weight of THF at room temperature was dropped into the flask. After completion of the dropwise addition, the reaction mixture was stirred at room temperature for 2 hours, then, the reaction mixture was concentrated under reduced pressure, and 200 parts by weight of a 2% aqueous hydrochloric acid solution was added thereto. The precipitated crystals were collected by filtration under reduced pressure, and the obtained crystals were washed with water.
After drying for an hour, the desired carboxylic acid derivative was obtained.

Synthesis Example 2 Synthesis of exemplified compound (AD1-36). In a flask equipped with a stirrer and a calcium chloride drying tube, 14.8 parts by weight of phthalic anhydride and triethylamine 1 were added.
1.2 parts by weight and 100 parts by weight of tetrahydrofuran (THF) were charged, and a solution prepared by dissolving 16.1 parts by weight of m- (trifluoromethyl) aniline in 50 parts by weight of THF at room temperature was dropped into the flask. After completion of the dropwise addition, the reaction mixture was stirred at room temperature for 2 hours, then, the reaction mixture was concentrated under reduced pressure, and 200 parts by weight of a 2% aqueous hydrochloric acid solution was added thereto. The precipitated crystals were collected by filtration under reduced pressure, and the obtained crystals were washed with water and dried at 50 ° C. for 24 hours to obtain a desired carboxylic acid derivative.

Synthesis Example 3 Preparation of zinc salt of exemplified compound (AD1-32). The exemplary compound (AD1-3) was placed in a flask equipped with a stirrer.
2) 9.3 parts by weight, 3.8 parts by weight of sodium bicarbonate,
And 120 parts by weight of distilled water were charged and dissolved in a 60 ° C. water bath with stirring. The mixture was allowed to cool to room temperature, and zinc sulfate 7
An aqueous solution in which 4.8 parts by weight of the hydrate was dissolved in 50 parts by weight of distilled water was added dropwise. After completion of the dropwise addition, the mixture was further stirred at room temperature for 5 hours.
The precipitated crystals were collected by filtration under reduced pressure. The obtained crystals were washed with water and dried at 40 ° C. for 24 hours to obtain a desired zinc salt of a carboxylic acid derivative.

The charge transfer material used for the charge transfer layer includes a hole transfer material and an electron transfer material. Examples of the hole transfer material include oxadiazole compounds described in JP-B-34-5466 and JP-B-45-55.
Japanese Patent Application Publication No. Sho 56-123544, a triphenylmethane compound disclosed in Japanese Patent Publication No. 5 (1994) -42, a pyrazoline compound disclosed in Japanese Patent Publication No. 52-4188, a hydrazone compound disclosed in Japanese Patent Publication No. 55-42380, Oxadiazole compounds disclosed in JP-B-58-32
No. 372, a triarylamine compound, a stilbene compound described in JP-A-58-198043, and an enamine compound described in JP-A-62-237458. On the other hand, examples of electron transfer materials include chloranil, tetracyanoethylene, diphenoquinone, 2,4,7-trinitro-9-
Fluorenone, 2,4,5,7-tetranitroxanthone, 1,3,7-trinitrodibenzothiophene and the like. These charge transfer materials can be used alone or in combination of two or more.

Among these charge transfer materials, hydrazone compounds, stilbene compounds, enamine compounds and the like are preferable because they have a high hole-transfer ability and provide a highly sensitive photoreceptor. For example, in the case of a hydrazone compound, the compounds described in JP-B-55-42380, JP-A-1-100555 and JP-A-2-103 can be used.
Nos. 67, 2-51163, 2--9676
No. 7, JP-A-2-183260, JP-A-2-2-1848
Nos. 56, 2-184858 and 2-184
The hydrazone compounds described in JP-A-859 can be used, and hydrazone compounds described in JP-A-2-226160, JP-A-5-188609 and the like are particularly preferable. As the stilbene compound, compounds disclosed in JP-A-3-75660, and as the enamine compound, compounds disclosed in JP-A-2-51162 and JP-A-6-194851 are preferable.

Examples of the binder resin used for the charge transfer layer include polymers and copolymers of vinyl compounds such as styrene, vinyl chloride, vinyl acetate, acrylates and methacrylates, polycarbonate resins, polyarylate resins and polyester resins. And various polymers such as phenoxy resin, polysulfone, cellulose ester resin, cellulose ether resin, urethane resin, epoxy resin and silicone resin.

Examples of the solvent used for forming the charge transfer layer include tetrahydrofuran, 1,3-dioxolan, methyl ethyl ketone, benzene, toluene, monochlorobenzene, 1,2-dichloroethane, dichloromethane, chloroform, and ethyl acetate.

The binder resin used in the charge transfer layer is used in an amount of 10 to 500 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight of the charge transfer material. The thickness of the charge transfer layer is in the range of 1 to 100 μm, preferably 10 to 50 μm.

The charge transfer layer can be provided by dissolving a charge transfer substance such as a hydrazone compound or a styryl compound and a binder resin in an appropriate solvent, coating and drying.

As the conductive support on which the photosensitive layer of the electrophotographic photoreceptor of the present invention is formed, any of those used for known electrophotographic photoreceptors can be used. In particular,
For example, a drum, a sheet, a belt of gold, silver, platinum, titanium, aluminum, copper, zinc, iron, a metal oxide or the like subjected to a conductive treatment, a laminate of these thin films, a deposit, or the like can be used.

Further, metal powder, metal oxide, carbon black, carbon fiber, copper iodide, charge transfer complex, inorganic salt,
Drums, sheets, belts, etc. made of plastics, ceramics, papers, etc., which are obtained by applying a conductive material such as an ion-conductive polymer electrolyte together with a suitable binder and embedding in a polymer matrix to give a conductive treatment. .

In the construction of the electrophotographic photosensitive member of the present invention, a blocking layer for controlling charge injection from the photosensitive layer to the conductive support may be provided between the photosensitive layer and the conductive support, if necessary. A surface protective layer may be provided on the surface of the photosensitive layer to improve the durability of the photosensitive member.

The blocking layer is composed of a binder resin alone,
Alternatively, it is composed of a mixture of a binder resin and an inorganic pigment. Examples of the binder resin include a polyamide resin, an epoxy resin, and a urethane resin. Also,
Examples of the inorganic pigment include titanium oxide, zinc oxide, zirconium oxide, and the like.

Further, the photosensitive layer may contain a well-known plasticizer in order to improve film formability, flexibility and mechanical strength. Examples of the plasticizer include phthalic acid esters, phosphoric acid esters, chlorinated paraffins, chlorinated fatty acid esters, and aromatic compounds such as methylnaphthalene.

Further, in order to improve the electrophotographic characteristics of the photoreceptor, additives such as an antioxidant may be contained.

[0098]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The charge generating material, the charge transfer material, and the comparative compound used in Examples and Comparative Examples of the present invention are shown below.

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Example 1 1 part by weight of a charge generating substance represented by the exemplified compound (CG-1) and 1 part by weight of a polyvinyl butyral resin (Denka Butyral # 3000-K, manufactured by Denki Kagaku Kogyo Kogyo) were mixed with 1,2-dimethoxyethane 100 The resulting mixture was mixed with glass beads (manufactured by Shinmaru Enterprises, Hybee D-20) for 4 hours using a paint conditioner. The pigment dispersion thus obtained was applied on a metal aluminum thin plate (JIS standard # 1050) using an applicator.
After drying at 15 ° C. for 15 minutes, a charge generation layer having a thickness of about 0.4 μm was obtained.

Next, 10 parts by weight of the charge transfer material represented by Exemplified Compound (CT-1), 0.1 part by weight of a nickel salt of a carboxylic acid derivative represented by Exemplified Compound (AD1-9), and a polycarbonate resin (manufactured by Teijin Chemicals Limited) , Panlight C-13
00) was dissolved in 150 parts by weight of dichloromethane, and this solution was applied on the charge generation layer by an applicator and dried at 80 ° C. for 60 minutes to form a charge transfer layer having a dry film thickness of 20 μm.

The thus-prepared laminated electrophotographic photosensitive member was stored in the dark at room temperature for 24 hours, and then evaluated for electrophotographic characteristics with an electrostatic recording tester (SP-428, manufactured by Kawaguchi Electric Works). The measurement conditions were: Corona applied voltage: -5k
V, static mode No. 3 (process speed 167
mm / s) and irradiation light (white light) illuminance: 2 lx.
As a result, the charging potential was -710 V and the half-exposure amount was 0.86 l.
The value of x · s was very high. Table 1 shows the results. After irradiating the photosensitive member with white light (5000 lx) for 1 minute, the electrophotographic characteristics were evaluated under the same conditions, and the ratio of the charging potential after light irradiation to the charging potential before light irradiation was expressed as a percentage. The exposure characteristics were evaluated. Table 2 shows the results.

Next, this photoreceptor was attached to a drum tube made of aluminum, and the repetition characteristics of charging and light elimination were evaluated by a drum photoreceptor evaluation device (Gentech, Cynthia 90). The measurement was performed with a corona applied voltage of -5.2 k.
V, the process speed was 160 mm / s, and the charge and light elimination were repeated 5000 times in TCCD2 mode. Light elimination was performed using a tungsten lamp array. Table 1 shows the measurement results of the surface potential after charging, that is, the charging potential, and the surface potential after light removal, that is, the residual potential. It can be seen that changes in the charging potential and the residual potential are extremely small. Further, the surface state of the photoreceptor after the repeated test was observed, and the presence or absence of a crystallization point was examined. Table 2 shows the results.

Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the zinc salt was used instead of the nickel salt of the exemplified compound (AD1-9). The same test as in Example 1 was performed.

Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the nickel salt of Exemplified Compound (AD1-9) was replaced by the cobalt salt of Exemplified Compound (AD1-24). A body was prepared, and the same test as in Example 1 was performed.

Example 4 An electrophotographic method was performed in the same manner as in Example 1 except that the zinc salt of the exemplified compound (AD1-36) was used instead of the nickel salt of the exemplified compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Example 5 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the nickel salt of the exemplified compound (AD1-9) was replaced by the aluminum salt of the exemplified compound (AD1-52). A body was prepared, and the same test as in Example 1 was performed.

Example 6 The procedure of Example 1 was repeated, except that the nickel salt of the exemplified compound (AD1-9) was replaced by the cobalt salt of the exemplified compound (AD2-19). A body was prepared, and the same test as in Example 1 was performed.

Example 7 The procedure of Example 1 was repeated, except that the nickel salt of Exemplified Compound (AD1-9) was replaced by the aluminum salt of Exemplified Compound (AD3-7). A body was prepared, and the same test as in Example 1 was performed.

Example 8 Electrophotography was performed in the same manner as in Example 1, except that the zinc salt of the exemplified compound (AD3-23) was used instead of the nickel salt of the exemplified compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Example 9 The procedure of Example 1 was repeated, except that the nickel salt of the exemplified compound (AD3-38) was used instead of the nickel salt of the exemplified compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Example 10 The procedure of Example 1 was repeated, except that the nickel salt of the exemplified compound (AD1-9) was replaced by the zinc salt of the exemplified compound (AD4-18). A body was prepared, and the same test as in Example 1 was performed.

Comparative Example 1 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the nickel salt of the exemplified compound (AD1-9) was not contained. went.

Comparative Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the chromium salt of the comparative compound (EX-1) was used in place of the nickel salt of the exemplary compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Comparative Example 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that the cobalt salt of the comparative compound (EX-5) was used instead of the nickel salt of the exemplary compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Comparative Example 4 The procedure of Example 1 was repeated, except that the zinc salt of the comparative compound (EX-8) was used instead of the nickel salt of the exemplary compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

Comparative Example 5 An electrophotographic method was performed in the same manner as in Example 1 except that the zinc salt of the comparative compound (EX-11) was used instead of the nickel salt of the exemplary compound (AD1-9). A body was prepared, and the same test as in Example 1 was performed.

The results of the electrical characteristics of Examples 1 to 10 are shown in Table 1, and Table 2 shows the presence or absence of crystallization points on the surface of the photoreceptor after the pre-exposure characteristic test and the repeated test. Table 3 shows the results of the electrical characteristics of Comparative Examples 1 to 5, and Table 4 shows the presence or absence of crystallization points on the photoreceptor surface after the pre-exposure characteristic test and the repeated test.

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As described above, the photoconductors exemplified in Examples 1 to 10 have high sensitivity and repetition stability in Examples 6 and 10, although the sensitivity and the repetition stability are slightly inferior to the others in Examples 6 and 10. Excellent pre-exposure characteristics and excellent solubility and compatibility of additives. On the other hand, the photoconductors exemplified in Comparative Examples 1 to 5 have low sensitivity as a whole, low repetition stability, poor pre-exposure characteristics, and poor solubility and compatibility of additives. Except for Comparative Example 1, the crystallization point was generated. In Comparative Example 1, since no additive was added, no decrease in the pre-exposure characteristics and no crystallization point were observed, but the change in the charging potential and the residual potential due to repetition was extremely large. If the repetition stability is inferior as described above, in the actual copying evaluation, the repetition lowers the contrast of the actual image and fog occurs, and the crystallized crystal point causes a defect in the copied image.

Example 11 1 part by weight of the charge transfer material represented by the exemplified compound (CG-2) and 1 part by weight of a polyvinyl butyral resin (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) were mixed with 1 part by weight of methyl isobutyl ketone.
00 parts by weight, and dispersed with glass beads (Hybee D-20, manufactured by Shinmaru Enterprises) for 4 hours using a paint conditioner. The pigment dispersion thus obtained is applied to a metal aluminum sheet (J
It was applied on IS standard # 1050) and dried at 80 ° C. for 15 minutes to obtain a charge generation layer having a thickness of about 0.4 μm.

Next, 10 parts by weight of a charge transfer material represented by the exemplified compound (CT-2), 0.05 parts by weight of a zinc salt of a carboxylic acid derivative represented by the exemplified compound (AD1-35), and a polycarbonate resin (manufactured by Teijin Chemicals Limited) , TS-2050) 8
Parts by weight and polyester resin (manufactured by Toyobo, Byron 22
0) 2 parts by weight were dissolved in 150 parts by weight of dichloromethane, and the solution was applied on the charge generating layer by an applicator and dried at 80 ° C. for 60 minutes to obtain a dry film thickness of 20 μm.
m of charge transfer layers were formed.

After the laminated electrophotographic photosensitive member thus produced was stored in the dark at room temperature for 24 hours, electrophotographic characteristics were evaluated by an electrostatic recording tester (SP-428, manufactured by Kawaguchi Electric Works). The measurement conditions were as follows: Corona applied voltage: -5.
0 kV, static mode No. 3 (Process speed 1
67 mm / s) and irradiation light (white light) illuminance: 2 lx. As a result, the charging potential was -720 V and the half-exposure amount was 0.9.
It showed a very high sensitivity value of 0 lx · s. Table 5 shows the results. In addition, white light (5000 lx) was applied to this photoreceptor for 1
After irradiation for 1 minute, the electrophotographic characteristics were evaluated under the same conditions, and the ratio of the charging potential after light irradiation to the charging potential before light irradiation was expressed as a percentage to evaluate pre-exposure characteristics. Table 6 shows the results
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Next, this photoreceptor was attached to a drum tube made of aluminum, and the repetition characteristics of charging and light elimination were evaluated using a drum photoreceptor evaluation device (Gentech 90, Cynthia 90). The measurement was performed with a corona applied voltage of -5.2 k.
V, the process speed was 160 mm / s, and the charge and light elimination were repeated 5000 times in TCCD2 mode. Light elimination was performed using a tungsten lamp array. Table 5 shows the measurement results of the surface potential after charging, that is, the charging potential, and the surface potential after light removal, that is, the residual potential. It can be seen that changes in the charging potential and the residual potential are extremely small. Further, the surface state of the photoreceptor after the repeated test was observed, and the presence or absence of a crystallization point was examined. Table 6 shows the results.

Example 12 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the zinc salt of the exemplified compound (AD1-35) was replaced with its aluminum salt. 1
The same test as in Example 1 was performed.

Example 13 The procedure of Example 11 was repeated, except that the zinc salt of the exemplary compound (AD2-30) was used instead of the zinc salt of the exemplary compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Example 14 The procedure of Example 11 was repeated, except that the zinc salt of the exemplary compound (AD1-35) was used instead of the zinc salt of the exemplary compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Example 15 An electrophotographic method was performed in the same manner as in Example 11, except that the zinc salt of the exemplified compound (AD2-27) was used instead of the zinc salt of the exemplified compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Example 16 An electrophotographic photosensitive member was prepared in the same manner as in Example 11, except that the zinc salt of the exemplified compound (AD3-6) was used instead of the zinc salt of the exemplified compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Example 17 The procedure of Example 11 was repeated, except that the zinc salt of Exemplified Compound (AD1-35) was replaced by the cobalt salt of Exemplified Compound (AD3-6). A body was prepared, and the same test as in Example 11 was performed.

Example 18 Electrophotography was performed in the same manner as in Example 11, except that the zinc salt of Exemplified Compound (AD1-35) was replaced by the cobalt salt of Exemplified Compound (AD4-6). A body was prepared, and the same test as in Example 11 was performed.

Example 19 An electrophotographic photosensitive member was prepared in the same manner as in Example 11, except that the nickel salt of the exemplified compound (AD3-25) was used instead of the nickel salt of the exemplified compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Example 20 The procedure of Example 11 was repeated, except that the nickel salt of the exemplary compound (AD1-35) was replaced by the zinc salt of the exemplary compound (AD3-28). A body was prepared, and the same test as in Example 11 was performed.

Comparative Example 6 An electrophotographic photosensitive member was prepared in the same manner as in Example 11 except that the zinc salt of the exemplified compound (AD1-35) was not contained, and the same test as in Example 11 was performed. Was.

Comparative Example 7 An electrophotographic photosensitive member was prepared in the same manner as in Example 11 except that the zinc salt of the comparative compound (EX-1) was used instead of the zinc salt of the exemplary compound (AD1-35). A body was prepared, and the same test as in Example 1 was performed.

Comparative Example 8 An electrophotographic photosensitive member was prepared in the same manner as in Example 11, except that the zinc salt of the exemplified compound (AD1-35) was replaced with the aluminum salt of the comparative compound (EX-4). A body was prepared, and the same test as in Example 11 was performed.

Comparative Example 9 An electrophotographic photosensitive member was prepared in the same manner as in Example 11, except that the zinc salt of the comparative compound (EX-7) was used in place of the zinc salt of the exemplary compound (AD1-35). A body was prepared, and the same test as in Example 11 was performed.

Comparative Example 10 The procedure of Example 11 was repeated, except that the zinc salt of the exemplified compound (AD1-35) was replaced by the cobalt salt of the comparative compound (EX-3). A body was prepared, and the same test as in Example 11 was performed.

The results of the electrical characteristics of Examples 11 to 20 are shown in Table 5, and the results of the pre-exposure characteristics and the presence / absence of crystallization points on the surface of the photoreceptor after the repeated test are shown in Table 6. Also,
Table 7 shows the results of the electrical characteristics of Comparative Examples 6 to 10,
Table 8 shows the results of the pre-exposure characteristics and the presence / absence of a crystallization point on the photoreceptor surface after the repeated test.

[0147]

[Table 5]

[0148]

[Table 6]

[0149]

[Table 7]

[0150]

[Table 8]

As described above, the photoconductors exemplified in Examples 11 to 20 have high sensitivity and repetition stability in Examples 13, 15, and 18, although the sensitivity and the repetition stability are slightly inferior to the others in Examples 13, 15 and 18. Excellent in solubility and pre-exposure characteristics, and excellent in solubility and compatibility of additives. On the other hand, the photoconductors exemplified in Comparative Examples 1 to 5 have low sensitivity as a whole, low repetition stability, inferior pre-exposure characteristics, and poor solubility and compatibility of additives. Except for Comparative Example 6, the crystallization point was generated. In Comparative Example 6, since no additive was added, no decrease in pre-exposure characteristics and no crystallization point were observed, but the change in the charging potential and the residual potential due to repetition was extremely large. If the repeat stability is poor like this,
In the actual copy evaluation, the contrast of the actual image is reduced and fogging occurs due to repetition, and the crystallized point causes a copy image defect.

Example 21 One part by weight of the charge transfer material represented by the exemplified compound (CG-3) and 1 part by weight of a polyvinyl butyral resin (Eslek KS-1 manufactured by Sekisui Chemical Co., Ltd.) were mixed with 100 parts of methyl ethyl ketone.
Parts by weight and mixed with glass beads (Shinmaru Enterprises, Hibee D) by a paint conditioner.
-20) and dispersed for 4 hours. The pigment dispersion thus obtained is applied to a metal aluminum sheet (JIS) using an applicator.
Standard # 1050) and dried at 80 ° C. for 15 minutes to obtain a charge generation layer having a thickness of about 0.4 μm.

Next, 10 parts by weight of a charge transfer material represented by the exemplified compound (CT-3), 0.05 parts by weight of an aluminum salt of a carboxylic acid derivative represented by the exemplified compound (AD1-25) and a polycarbonate resin (manufactured by Idemitsu Kosan Co., Ltd.) , Tuffet B-500) is dissolved in 150 parts by weight of dichloromethane, and the solution is applied on the above-mentioned charge generating layer by an applicator and dried at 80 ° C. for 60 minutes to transfer a charge having a dry film thickness of 20 μm. A layer was formed.

The thus-prepared laminated electrophotographic photosensitive member was stored in the dark at room temperature for 24 hours, and then evaluated for electrophotographic characteristics using an electrostatic recording tester (SP-428, manufactured by Kawaguchi Electric Works). The measurement conditions were: Corona applied voltage: -5k
V, static mode No. 3 (process speed 167
mm / s) and irradiation light (white light) illuminance: 2 lx.
As a result, the charging potential was -715 V, the half-exposure amount was 0.98 l.
The value of x · s was very high. Table 9 shows the results. After irradiating the photosensitive member with white light (5000 lx) for 1 minute, the electrophotographic characteristics were evaluated under the same conditions, and the ratio of the charging potential after light irradiation to the charging potential before light irradiation was expressed as a percentage. The exposure characteristics were evaluated. Table 10 shows the results.
Shown in

Next, this photoreceptor was attached to a drum tube made of aluminum, and the repetition characteristics of charging and light elimination were evaluated by a drum photoreceptor evaluation apparatus (Gentech, Cynthia 90). The measurement was performed with a corona applied voltage of -5.2 k.
V, the process speed was 160 mm / s, and the charge and light elimination were repeated 5000 times in TCCD2 mode. Light elimination was performed using a tungsten lamp array. Table 9 shows the measurement results of the surface potential after charging, that is, the charging potential, and the surface potential after light removal, that is, the residual potential. It can be seen that changes in the charging potential and the residual potential are extremely small. Further, the surface state of the photoreceptor after the repeated test was observed, and the presence or absence of a crystallization point was examined. Table 10 shows the results.

Example 22 The procedure of Example 21 was repeated, except that the aluminum salt of the exemplified compound (AD1-25) was replaced by the exemplified compound (AD1-29).
An electrophotographic photoreceptor was prepared in the same manner as in Example 21, except that the aluminum salt was used, and the same test as in Example 21 was performed.

Example 23 In Example 21, the exemplified compound (AD1-42) was used in place of the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was produced in the same manner as in Example 21 except that the zinc salt was used, and the same test as in Example 21 was performed.

Example 24 The procedure of Example 21 was repeated, except that the aluminum salt of the exemplified compound (AD1-25) was replaced with the exemplified compound (AD1-54).
An electrophotographic photoreceptor was prepared in the same manner as in Example 21, except that the aluminum salt was used, and the same test as in Example 21 was performed.

Example 25 The procedure of Example 21 was repeated, except that the aluminum salt of the exemplified compound (AD1-25) was replaced by the exemplified compound (AD1-29).
An electrophotographic photoreceptor was prepared in the same manner as in Example 21 except that the magnesium salt was used, and the same test as in Example 21 was performed.

Example 26 In Example 21, the exemplified compound (AD3-29) was used in place of the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was produced in the same manner as in Example 21 except that the zinc salt was used, and the same test as in Example 21 was performed.

Example 27 In Example 11, the exemplified compound (AD3-48) was used in place of the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was produced in the same manner as in Example 21 except that the zinc salt was used, and the same test as in Example 21 was performed.

Example 28 In Example 21, the exemplified compound (AD3-51) was used in place of the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was produced in the same manner as in Example 21 except that the chromium salt was used, and the same test as in Example 21 was performed.

Example 29 In Example 21, the exemplified compound (AD3-62) was used in place of the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was produced in the same manner as in Example 21 except that the chromium salt was used, and the same test as in Example 21 was performed.

Example 30 In Example 21, the exemplified compound (AD3-30) was replaced with the aluminum salt of the exemplified compound (AD1-25).
An electrophotographic photoreceptor was prepared in the same manner as in Example 21 except that the nickel salt was used, and the same test as in Example 21 was performed.

Comparative Example 11 An electrophotographic photosensitive member was prepared in the same manner as in Example 21, except that the zinc salt of the comparative compound (EX-2) was used in place of the aluminum salt of the exemplary compound (AD1-25). A body was prepared and the same test as in Example 21 was performed.

Comparative Example 12 An electrophotographic photosensitive member was prepared in the same manner as in Example 21, except that the chromium salt of the comparative compound (EX-6) was used in place of the aluminum salt of the exemplary compound (AD1-25). A body was prepared and the same test as in Example 21 was performed.

Comparative Example 13 The procedure of Example 21 was repeated, except that the zinc salt of the comparative compound (EX-9) was used instead of the aluminum salt of the exemplified compound (AD1-25). A photographic photoreceptor was manufactured and the same test as in Example 21 was performed.

Comparative Example 14 An electrophotographic photosensitive member was prepared in the same manner as in Example 21, except that the zinc salt of the comparative compound (EX-10) was used in place of the aluminum salt of the exemplary compound (AD1-25). A body was prepared and the same test as in Example 21 was performed.

Comparative Example 15 An electrophotographic method was performed in the same manner as in Example 21, except that the sodium salt of the comparative compound (EX-12) was used instead of the aluminum salt of the exemplary compound (AD1-25). A body was prepared and the same test as in Example 21 was performed.

Table 9 shows the results of the electrical characteristics of Examples 21 to 30, and Table 10 shows the results of the pre-exposure characteristics and the presence / absence of crystallization points on the surface of the photoreceptor after the repeated test. Table 11 shows the results of the electrical characteristics of Comparative Examples 11 to 15.
Table 12 shows the results of the pre-exposure characteristics and the presence or absence of a crystallization point on the surface of the photoreceptor after the repeated test.

[0171]

[Table 9]

[0172]

[Table 10]

[0173]

[Table 11]

[0174]

[Table 12]

As described above, the photoreceptors exemplified in Examples 21 to 30 have high sensitivity and repetition stability in Examples 25 and 29, though they are slightly inferior in sensitivity and repetition stability in Examples 25 and 29. Excellent pre-exposure characteristics and excellent solubility and compatibility of additives. On the other hand, Comparative Examples 11 to 1
The photoreceptors exemplified in Example 5 were generally low in sensitivity, inferior in repetition stability and pre-exposure characteristics, and inferior in solubility and compatibility of the additives. If the repetition stability is inferior as described above, in the actual copying evaluation, the repetition lowers the contrast of the actual image and fog occurs, and the crystallized crystal point causes a defect in the copied image.

Example 31 1 part by weight of τ-type metal-free phthalocyanine (TPA-891 manufactured by Toyo Ink Manufacturing Co., Ltd.) as a charge transfer material and vinyl chloride
One part by weight of a vinyl acetate copolymer resin (manufactured by Sekisui Chemical Co., Ltd., ESLEC C) was mixed with 100 parts by weight of butyl acetate, and dispersed together with glass beads (manufactured by Shinmaru Enterprises, Hybee D-20) for 4 hours using a paint conditioner. The pigment dispersion thus obtained was applied to a thin metal aluminum plate (JIS # 1050) using an applicator and dried at 80 ° C. for 15 minutes to obtain a charge generation layer having a thickness of about 0.4 μm.

Next, 10 parts by weight of a charge transfer material represented by the exemplified compound (CT-4), 0.1 part by weight of a zinc salt of a carboxylic acid derivative represented by the exemplified compound (AD2-36), and a polycarbonate resin (manufactured by Teijin Chemicals Limited) , Panlight K-130
0) 10 parts by weight were dissolved in 150 parts by weight of dichloromethane, and this solution was applied on the charge generating layer by an applicator and dried at 80 ° C. for 60 minutes to obtain a dry film thickness of 20%.
A μm charge transfer layer was formed.

After the laminated electrophotographic photoreceptor thus produced was stored in the dark at room temperature for 24 hours, the electrophotographic characteristics were evaluated using an electrostatic recording tester (SP-428, manufactured by Kawaguchi Electric Works). The measurement conditions were: Corona applied voltage: -5k
V, static mode No. 3 (process speed 167
mm / s) and irradiation light (white light) illuminance: 2 lx.
As a result, the charging potential was -680 V, the half-reduction exposure amount was 0.98 l.
The value of x · s was very high. Table 13 shows the results. After irradiating the photosensitive member with white light (5000 lx) for 1 minute, the electrophotographic characteristics were evaluated under the same conditions, and the ratio of the charging potential after light irradiation to the charging potential before light irradiation was expressed as a percentage. The exposure characteristics were evaluated. Table 14 shows the results.
Shown in

Next, this photoreceptor was stuck on a drum drum made of aluminum, and the repetition characteristics of charging and light elimination were evaluated by a drum photoreceptor evaluation device (Cynthia 90, manufactured by Gentec). The measurement was performed with a corona applied voltage of -5.2 k.
V, the process speed was 160 mm / s, and the charge and light elimination were repeated 5000 times in TCCD2 mode. Light elimination was performed using a tungsten lamp array. Table 13 shows the measurement results of the surface potential after charging, that is, the charging potential, and the surface potential after light removal, that is, the residual potential. It can be seen that changes in the charging potential and the residual potential are extremely small. Further, the surface state of the photoreceptor after the repeated test was observed, and the presence or absence of a crystallization point was examined. Table 14 shows the results.

Example 32 An electrophotographic photosensitive member was prepared in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD1-36) was used instead of the zinc salt of the exemplified compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Example 33 Electrophotography was performed in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD2-36) was replaced with the aluminum salt of the exemplified compound (AD1-50). A body was prepared and the same test as in Example 31 was performed.

Example 34 Electrophotography was performed in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD2-36) was replaced with the cobalt salt of the exemplified compound (AD1-57). A body was prepared and the same test as in Example 31 was performed.

Example 35 Electrophotography was performed in the same manner as in Example 31 except that the zinc salt of the exemplified compound (AD2-36) was replaced by a copper salt of the exemplified compound (AD1-63). A body was prepared and the same test as in Example 31 was performed.

Example 36 Electrophotography was performed in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD3-11) was used instead of the zinc salt of the exemplified compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Example 37 Electrophotography was performed in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD2-36) was replaced with the aluminum salt of the exemplified compound (AD3-22). A body was prepared and the same test as in Example 31 was performed.

Example 38 An electrophotographic photosensitive member was prepared in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD3-34) was used instead of the zinc salt of the exemplified compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Example 39 An electrophotographic photoreceptor was prepared in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD4-29) was used instead of the zinc salt of the exemplified compound (AD2-26). A body was prepared and the same test as in Example 31 was performed.

Example 40 An electrophotographic photosensitive member was prepared in the same manner as in Example 31 except that the nickel salt of the exemplified compound (AD3-54) was used in place of the zinc salt of the exemplified compound (AD2-36). A body was prepared, and the same test as in Example 11 was performed.

Comparative Example 16 An electrophotographic photosensitive member was prepared in the same manner as in Example 11, except that the zinc salt of the exemplified compound (AD2-36) was replaced by the exemplified compound (AD2-36) itself. It was fabricated and subjected to the same test as in Example 11.

Comparative Example 17 An electrophotographic method was performed in the same manner as in Example 31, except that the zinc salt of the exemplified compound (AD2-36) was replaced with the aluminum salt of the comparative compound (EX-1). A body was prepared and the same test as in Example 31 was performed.

Comparative Example 18 An electrophotographic photosensitive member was prepared in the same manner as in Example 31, except that the zinc salt of the comparative compound (EX-2) was used in place of the zinc salt of the exemplary compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Comparative Example 19 An electrophotographic photosensitive member was prepared in the same manner as in Example 31, except that the cobalt salt of the comparative compound (EX-5) was used in place of the zinc salt of the exemplary compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Comparative Example 20 Electrophotography was performed in the same manner as in Example 31, except that the zinc salt of the comparative compound (EX-12) was used instead of the zinc salt of the exemplary compound (AD2-36). A body was prepared and the same test as in Example 31 was performed.

Table 13 shows the results of the electrical characteristics of Examples 31 to 40, and Table 14 shows the results of the pre-exposure characteristics and the presence / absence of crystallization points on the photoreceptor surface after the repeated test. Table 15 shows the results of the electrical characteristics of Comparative Examples 16 to 20.
Table 16 shows the results of the pre-exposure characteristics and the presence or absence of crystallization points on the surface of the photoreceptor after the repeated test.

[0195]

[Table 13]

[0196]

[Table 14]

[0197]

[Table 15]

[0198]

[Table 16]

As described above, the photosensitive members exemplified in Examples 31 to 40 have high sensitivity, excellent repetition stability, excellent pre-exposure characteristics, and excellent solubility and compatibility of additives. On the other hand, the photoconductors exemplified in Comparative Examples 16 to 20 are generally low in sensitivity, have poor repetition stability and poor pre-exposure characteristics, and have poor solubility and compatibility of additives.
Except for Comparative Example 16, all crystallization points occurred. Comparative Example 16
Is a carboxylic acid derivative itself represented by the exemplified compound (AD2-46), and does not show a significant decrease in pre-exposure characteristics or generation of a crystallization point, but a change in the charged potential and the residual potential due to repetition is extremely large. Big. If the repetition stability is inferior as described above, in the actual copying evaluation, the repetition lowers the contrast of the actual image and fog occurs, and the crystallized crystal point causes a defect in the copied image.

As can be seen from Examples 1 to 40, in an electrophotographic photosensitive member having at least a photosensitive layer composed of a charge generating layer and a charge transfer layer on a conductive support, an additive was added to the charge transfer layer by the general formula ( By including at least one metal salt of a carboxylic acid derivative represented by I), an electrophotographic photosensitive member having high sensitivity, excellent pre-exposure characteristics, and excellent repetition stability can be provided. In addition, the metal salt of the carboxylic acid derivative in the present invention is easily soluble in a solvent for forming a charge transfer layer such as dichloromethane, and has excellent compatibility with a charge transfer material and a binder resin. No crystallization point is generated in the photosensitive layer. on the other hand,
Although the comparative compound has an effect of suppressing the residual potential change to some extent, the pre-exposure characteristics are deteriorated, the solubility in the solvent for forming the charge transfer layer such as dichloromethane is low, and it takes a very long time to dissolve or completely. Is not dissolved and becomes colloidal. When a photoreceptor is formed, a fine crystallization point is generated in the photosensitive layer, or the crystallized point is enlarged or generated by repeated use, which is a serious problem in practical use.

[0201]

As is apparent from the above, according to the present invention, it is possible to provide an electrophotographic photoreceptor having high sensitivity and excellent pre-exposure characteristics and repetition stability.

Claims (4)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer comprising at least a charge generation layer and a charge transfer layer on a conductive support, wherein the charge transfer layer comprises a carboxylic acid derivative represented by the following general formula (I): An electrophotographic photosensitive member comprising at least one metal salt. Embedded image (In the formula (I), X represents —NHCO— or —SO ₂
Represents NH-, R represents a divalent linking group, and Ar represents an aromatic ring residue or a heteroaromatic ring residue which may have a substituent. ) 2. The electrophotographic photosensitive material according to claim 1, wherein R of the carboxylic acid derivative represented by the general formula (I) is a phenylene group or an alkylene group which may have a substituent. body. 3. The electrophotographic photoreceptor according to claim 1, wherein Ar of the carboxylic acid derivative represented by the general formula (I) is a phenyl group which may have a substituent. . 4. The metal salt of the carboxylic acid derivative represented by the general formula (I) is at least one of an aluminum salt, a zinc salt, a chromium salt, a cobalt salt, a nickel salt, an iron salt, and a copper salt. 4. The method according to claim 1, wherein
13. The electrophotographic photoreceptor according to item 6.