JPH06301226A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor excellent in electrical characteristics and image quality, keeping the electrical characteristics and image quality almost independent of the outer environment and ensuring satisfactory productivity by forming a specified hardened film as an intermediate layer. CONSTITUTION:When an intermediate layer and a photosensitive layer are successively formed on an electric conductive substrate to obtain an electrophotographic receptor, a hardened film based on amino resin hardened with carboxylic acid, carboxylic acid anhydride or a carboxylic acid-carboxylic acid anhydride mixture as a catalyst and doped with ferric chloride is formed as the intermediate layer by dissolving or dispersing a mixture prepd. by adding various materials to amino resin, carboxylic acid (anhydride) and ferric chloride as essential components in a proper solvent such as a xylol-butanol mixed solvent, THF or methanol, coating the electric conductive substrate with the resulting coating liq. by spraying, dipping or other system and carrying out heating and hardening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to an electrophotographic photosensitive member having a novel intermediate layer and having excellent and stable electric characteristics and image quality.

[0002]

2. Description of the Related Art Electrophotographic photoconductors (hereinafter also simply referred to as photoconductors) used in electrophotographic apparatuses starting from the invention of Carlson have hitherto been inorganic photoconductive materials such as selenium, selenium alloys, zinc oxide, and cadmium sulfide. The mainstream was the use of materials. However, recently, in view of nontoxicity, film-forming property, light weight, low price and the like, development of a photoconductor using an organic photoconductive material has been actively promoted. Among them, the so-called function-separated laminated type organic photoconductor in which the photosensitive layer is divided into a charge generation layer that receives light and generates charge carriers and a charge transfer layer that moves the generated charge carriers It is a mainstream of development because it has many advantages such as being able to significantly improve the sensitivity by forming and combining it with a material optimal for the function of the layer, and being able to increase its spectral sensitivity according to the wavelength of the exposure light. It has been put into practical use and has been used in electrophotographic devices such as copiers, printers and fax machines.

The mainstream of the function-separated laminated type organic photoconductors currently in practical use is a structure in which a photoconductive layer having a charge generation layer and a charge transfer layer laminated in this order on a conductive substrate. . Such a photosensitive member is obtained by sublimating or vapor-depositing an organic charge generating agent on a conductive substrate, or coating and drying a coating liquid in which the organic charge generating agent is dispersed and dissolved in an organic solvent together with a binder. Then, a charge generating layer is formed, and subsequently, a coating liquid in which a charge transfer agent is dissolved in an organic solvent together with a binder is applied and dried to form a charge transfer layer. Basically, the basic performance as a photoreceptor for image formation can be exhibited with such a layer structure. However, it is practically important to obtain a good image free from defects, and it is required that a good image quality be maintained even after repeated use for a long period of time. For that purpose, it is necessary to form a photosensitive layer having a uniform and defect-free film quality and to have excellent electrical properties of the photoconductor. In addition, even if it is used for a long period of time, the film quality and electrical properties are not deteriorated and stable. Is required.

By the way, the charge generation layer absorbs light to generate charge carriers, but the generated charge carriers move quickly without recombination, disappearance, or trapping, and the conductive substrate or It needs to be injected into the charge transfer layer. For this reason, it is desirable to make the charge generation layer as thin as possible, and in the currently practiced photoreceptors, the charge generation layer having a film thickness of the submicron order is usually formed. Since the charge generation layer is formed as such a thin film, dirt on the surface of the conductive substrate,
The non-uniformity and roughness of the shape and properties appear as film formation unevenness of the charge generation layer as they are, resulting in a problem that image defects such as white spots, black spots, and density unevenness occur in the resulting image. As the conductive substrate, an aluminum alloy drawing cylinder or a cylinder whose surface is smoothed by cutting and polishing is generally used. However, the surface roughness of the substrate, surface stains, and alloy components are included. Due to variations in the amount and size of metal deposits and variations in surface properties due to variations in the degree of oxidation of the surface, film formation unevenness occurs in the charge generation layer formed on the surface, and It will have a big impact on quality.

In order to prevent such unevenness of film formation and to obtain a blocking effect for preventing a decrease in charge retention of the photoconductor due to injection of holes from a conductive substrate, which is required separately, a conductive property is obtained. It has been practiced to provide an intermediate layer made of an N-type resin having low electric resistance on the surface of a flexible substrate.

[0006]

As the resin used for the intermediate layer for such purpose, solvent-soluble polyamide, polyvinyl alcohol, polyvinyl butyral,
Resins such as casein are known. These resins are
An ultrathin film, for example, a thin film having a thickness of 0.1 μm or less, can sufficiently perform the above-mentioned purpose only for the purpose of a blocking layer. But for other purposes,
That is, in order to cover the surface shape of the conductive substrate, the variation of the surface properties and the surface stain, and to improve the non-uniformity of the wetting of the coating liquid for the charge generation layer to eliminate the unevenness of the film formation,
A film thickness of at least 1 μm is required, depending on the processing conditions of the substrate and the state of surface contamination, but in some cases 1 μm or more,
Alternatively, a film thickness of several tens of μm or more is required. However, when such a thick resin layer is formed from the above-mentioned polyvinyl alcohol, solvent-soluble polyamide, casein, etc., the residual potential rises, and the electrical characteristics of the photoconductor fluctuate in low-temperature low-humidity and high-temperature high-humidity environments. There was a problem that. This is because these resins have a large water absorption property, and most of the electric conduction is due to ion conduction due to dissociated hydrogen ions or hydrogen ions, and the electric resistance of the resin layer is the water content contained in the resin layer. This is because it fluctuates greatly due to.

Various materials have been conventionally proposed as materials suitable for the intermediate layer because the electric resistance of the layer having such a film thickness is low and the electric resistance thereof is small even when the surrounding environment changes. There is. For example, regarding a solvent-soluble polyamide resin, JP-A-2-193152, JP-A-3-288157, JP-A-4-31870 and the like are known to specify the chemical structure of the polyamide resin. In addition, as an effect expected to suppress a change in electric resistance due to a change in environment by adding an additive to a polyamide resin, JP-B-2-59458, JP-A-3-150572, and JP-A-2-530.
No. 70 publication is known. Further, a mixture of a polyamide resin and another resin is used to adjust the electric resistance and to expect an effect of weakening the influence of a change in the environment, as disclosed in JP-A-3-145652 and JP-A-3-817.
Japanese Patent Laid-Open No. 78 and Japanese Patent Laid-Open No. 2-281262 are known. However, the main material used in these methods is a polyamide resin, and the influence of temperature and humidity cannot be avoided.

An example of using a cellulose dielectric as a material other than the polyamide resin (Japanese Patent Laid-Open No. 2384/1990).
59), examples using polyether urethane (JP-A-2-115858, JP-A-2-280170), examples using polyvinylpyrrolidone (JP-A-2-
No. 105349), examples using polyglycol ether (Japanese Patent Laid-Open No. 2-79859), and the like, and from the idea that the amount of water in the resin layer does not depend on environmental changes. It is also proposed to use a crosslinkable resin, for example, an example using a melamine resin (JP-A-4-22966 and JP-B-4-31576).
Japanese Patent Publication No. 4-31577), an example using a phenol resin (Japanese Patent Laid-Open No. 3-48256), and the like are known. However, these methods are also effective when the resin layer is extremely thin, but when the film is relatively thick such as several μm, the resistance of the photoconductor becomes high, which causes an increase in residual potential.

As one of the methods for eliminating the above-mentioned drawbacks, it is conceivable that the electric conduction of the material forming the intermediate layer is changed to electronic conduction instead of ionic conduction due to moisture contained therein. As a method based on such an idea, a method of providing a resin layer in which a conductive powder such as tin oxide or indium oxide is dispersed has been proposed (Japanese Patent Publication No. 1-5118).
Japanese Patent Publication No. 5 and Japanese Patent Publication No. 48175 / Japanese Patent Publication No. 2-6
No. 0177, Japanese Patent Publication No. 2-62861). However, even with such a method, there are many difficulties in preparing a resin coating solution in which the conductive powder is uniformly dispersed, and the coating solution should be stored stably so that the conductive powder does not separate or settle. However, it is inevitable that minute projections are often formed on the surface of the resin layer formed by applying the conductive powder due to separation and aggregation of the conductive powder, which causes image defects on the photoreceptor. Therefore, there has been proposed a method of forming an intermediate layer by using an organometallic compound instead of the above-mentioned conductive powder, and applying a coating liquid in which the organometallic compound is dissolved in an organic solvent together with a resin (Patent Publication 3). -4904, Japanese Patent Laid-Open No. 2-5
9767). However, this method also has an unstable coating liquid and has many problems to be solved in order to carry out industrial mass production.

The present invention has been made in view of various problems associated with a resin layer as an intermediate layer provided on a conductive substrate as described above, and an intermediate layer containing a specific component is provided. Accordingly, it is an object of the present invention to provide a photoreceptor having excellent electrical characteristics and image quality, being less susceptible to the external characteristics of the electrical characteristics and image quality, and having good productivity.

[0011]

According to the present invention, the above object is to provide an electrophotographic photosensitive member comprising an electroconductive substrate on which an intermediate layer is provided and which is provided with a photosensitive layer.
A cured film containing, as a main component, an amino resin cured by using any one of a carboxylic acid, a carboxylic acid anhydride, and a mixture of a carboxylic acid and a carboxylic acid anhydride as a catalyst and doped with ferric chloride. It is solved by using a photoconductor that is.

[0012]

[Function] The amino resin is cured using "any one of carboxylic acid, carboxylic acid anhydride, and mixture of carboxylic acid and carboxylic acid anhydride" (hereinafter, also referred to as carboxylic acid (anhydride)) as a catalyst. The reason for this is not clear by using a cured film containing ferric chloride as the main component as the intermediate layer, but a film obtained by simply curing an amino resin with a carboxylic acid (anhydride) is used as an intermediate layer. Compared with the case of using a layer, it is extremely thick, for example, 10 μm to 20 μm
The residual potential is low even when the film thickness is set to 0, and problems such as deterioration of charging characteristics and increase of residual potential hardly occur even after repeated use, and electrical characteristics in a wide environmental range from high temperature and high humidity to low temperature and low humidity. It is possible to obtain an excellent photoconductor whose image quality hardly changes.

The amino resin according to the present invention is a methylol compound obtained by reacting a urea compound such as dicyandiamide, urea or thiourea, a triazine compound such as melamine, isomeramine, benzoguanamine or acetoguanamine with formaldehyde to give a methylol compound. For example, it is butyl etherified with butanol or isobutanol, and these are used alone or as a mixture or a cocondensate.

The carboxylic acids and carboxylic acid anhydrides include acetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, succinic acid, adipic acid, azelaic acid and other aliphatic carboxylic acids, terephthalic acid, isophthalic acid, Aromatic carboxylic acids such as phthalic anhydride, trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic dianhydride, 2-naphthalenecarboxylic acid, maleic acid,
Unsaturated carboxylic acids such as maleic anhydride, fumaric acid, itaconic acid, citraconic acid, alicyclic carboxylic acids such as linoleic acid, linoleic anhydride, endomethylenetetrahydrophthalic anhydride, chlorendic anhydride, etc. , Or can be mixed and used.

The amount of the carboxylic acid or carboxylic acid anhydride used is 5 parts by weight to 100 parts by weight of the amino resin.
100 parts by weight is a preferred range. If the addition amount is less than 5 parts by weight, the degree of curing of the film decreases and the solvent resistance decreases, and problems such as swelling and dissolution of the film occur when the charge generation layer is applied thereon, and 100 parts by weight. If the amount exceeds the above range, the pot life of the coating liquid becomes short, which is not preferable.

In the present invention, ferric chloride is doped into a cured film obtained by curing an amino resin with a carboxylic acid (anhydride) as a catalyst. For that purpose, ferric chloride is added to 100 parts by weight of the amino resin. 1 part by weight to 10 parts by weight of a carboxylic acid (anhydride) is dissolved to prepare a coating solution, which is applied, heated and dried to form a cured film. Further, the adhesion between the substrate and the intermediate layer is improved, the adhesion between the charge generating layer and the intermediate layer is improved, or an alcohol-soluble polyamide resin or the like is used as a main component between the intermediate layer and the charge generating layer, if necessary. When a thin film blocking layer is provided, the adhesion between the blocking layer and the intermediate layer can be improved, and an alkyd resin, a phenol resin or the like can be added to the intermediate layer. As the phenol resin, a resol type phenol resin obtained by condensing phenol and formaldehyde under an alkali catalyst can be used.

Furthermore, in the intermediate layer, in order to prevent sagging of the coating film, and in the intermediate layer provided in the photoconductor used in the electrophotographic apparatus which uses coherent light as the exposure light, the light reflected from the substrate is reflected. It is possible to add a filler in order to prevent moiré which appears in an image due to, and as the filler, titanium oxide, aluminum oxide, kaolin, talc, silicon oxide or the like is used.

The intermediate layer of the present invention comprises a mixture of an amino resin, a carboxylic acid (anhydride) and ferric chloride, which are essential main components, with various materials as described above, in a suitable solvent, for example. It is formed by dissolving and dispersing in a mixed solvent of xylol and butanol, tetrahydrofuran, methanol, etc. to prepare a coating liquid, applying the coating liquid on a conductive substrate by a spray method, a dipping method, etc., and heating and curing. . The heating is usually performed at a temperature of 80 ° C to 150 ° C, preferably 120 ° C.
It is sufficient to carry out at 20 to 130 ° C. for 20 minutes to 1 hour.

The intermediate layer thus formed has a sufficiently low electric resistance and is stable, and hardly changes even when the environment changes greatly from high temperature and high humidity to low temperature and low humidity. Therefore, even if the thickness of the intermediate layer is increased to 10 μm to 20 μm, the photoconductor has excellent electric characteristics, and even if it is repeatedly used, fluctuations in electric characteristics such as decrease in charging position, decrease in sensitivity, and increase in residual potential. Rarely occurs. Further, by forming such an intermediate layer of a thick film, the surface of the conductive substrate is covered with variations in properties, shape defects, variations in roughness, stains, etc., and a uniform photosensitive layer with few film defects is formed thereon. It is possible to form a thin charge generation layer easily without causing unevenness in film formation, especially in the case of a function-separated layered type photoreceptor in which a photosensitive layer is laminated in order of a charge generation layer and a charge transfer layer. can do. As a result, it is possible to obtain a photoconductor that can stably obtain a high-quality image with few image defects.

As described above, the present invention is particularly effective for a function-separated laminated type photoreceptor in which a photosensitive layer is laminated in the order of a charge generation layer and a charge transfer layer. In such a photoreceptor, the charge generation layer is a coating liquid in which a pigment such as a phthalocyanine-based pigment, an anthrone pigment, a perylene pigment, a perinone pigment, an azo pigment, or a disazo pigment is dispersed in a solution in which an appropriate binder resin is dissolved. Is coated on the above-mentioned intermediate layer and dried to form a coating film having a film thickness of 0.1 μm to 1 μm, and an enamine compound, a hydrazone compound, a styryl compound, an amine compound, etc. are formed on the film as a phase mixture with these compounds. A coating liquid dissolved in a suitable solvent together with a soluble binder resin such as polycarbonate, polyester, polystyrene, styrene acrylate, etc. is applied and dried to form a charge transfer layer having a film thickness of 5 μm to 40 μm.

Now, the resin used for the intermediate layer of the present invention will be described. (1) Amino resin Urea, melamine, benzoguanamine, acetoguanamine and the like are subjected to methylolation and methylene condensation under an alkali catalyst in a large amount of butanol together with an excess of formaldehyde, followed by butyl etherification under an acid catalyst. It is synthesized by performing. The degree of condensation varies depending on the amount of excess formaldehyde used and the strength of the alkali catalyst, but generally the number average molecular weight is 20
A condensate of 00 to 4000 is produced. When the reaction is carried out with only the acid catalyst from the beginning, a condensate having a number average molecular weight of about 1000 is obtained.

The amino resin thus obtained has long been known as a butylated urea resin, butylated melamine resin, butylated benzoguanamine resin, butylated melamine benzoguanamine co-condensation resin. For example, Uban (Mitsui Toatsu Commercially available under trade names such as Chemicals Co., Ltd., Beckamine and Super Beckamine (Dainippon Ink and Chemicals Co., Ltd.).

(2) Phenolic resin Phenol, m-cresol, o-cresol, p-cresol and the like are synthesized by condensing excess formaldehyde with an acid catalyst and an alkali catalyst.
Resol type phenolic resin synthesized under alkaline catalyst is desirable. Such resins are, for example, plyofen 5010, pryofen 5030-40K, pryofen TD-447, spar becasite 10.
01 (manufactured by Dainippon Ink and Chemicals, Inc.) and the like are commercially available.

By using such a phenol resin together with the above-mentioned amino resin, the adhesiveness between the intermediate layer and the conductive substrate is further improved. At that time, the amount of the phenol resin added to the amino resin is preferably 1 part by weight to 10 parts by weight of the resol type phenol resin with respect to 100 parts by weight of the amino resin. (3) Alkyd resin A resin in which glycerin, phthalic anhydride and a fatty acid are polyesterified by a dehydration condensation reaction under heating. The resin is divided into an oxidized type and a non-oxidized type depending on the fatty acid used, and is longer depending on the amount of the fatty acid in the resin. It is classified from oil type to short oil type. The alkyd resin used together with the amino resin of the present invention is preferably an alkyd resin using a drying oil such as soybean oil, linseed oil and tall oil as the glycerin fatty acid ester, and these alkyd resins are beccosol FS-
5103-50X, beccosol J-510 (manufactured by Dainippon Ink and Chemicals, Inc.) are commercially available. This resin cures by reacting with oxygen in the air, but a dryer is often used to accelerate the reaction with oxygen. As a dryer, cobalt naphthenate, manganese naphthenate, cobalt acetylacetonate, manganese acetylacetate is used. Nart or the like is used, and also in the present invention, such a dryer can be used when adding the alkyd resin to the amino resin. The amount of the alkyd resin added to the amino resin is preferably 5 parts by weight to 50 parts by weight with respect to 100 parts by weight of the amino resin, and the dryer is 0.1% by weight to the alkyd resin.
5% by weight is added.

[0025]

【Example】

[Example of Material Used for Intermediate Layer] In the examples, the following materials were used for forming the intermediate layer. (1) Amino resin A-1: 126 g of melamine, 400 g of n-butanol
A mixture of 150 g of r, paraformaldehyde and 0.3 g of a 1N hydrochloric acid aqueous solution was reacted for 2 hours under reflux dehydration at a temperature of 100 ° C. to distill n-butanol.
A resin liquid having a solid content of 50% by weight was obtained. The melamine resin thus obtained is designated as A-1. Analysis of this melamine resin revealed a number average molecular weight of 1500, a methylol group of 1.7 and a butyl ether group of 1.0.

A-2: U-Van 20HS (trade name; manufactured by Mitsui Toatsu Chemical Co., Ltd.) A-3: U-ban 91-55 (trade name; manufactured by Mitsui Toatsu Chemical Co., Ltd.) A-4: Super Beckamine TD-126 (trade name; manufactured by Dainippon Ink and Chemicals, Inc.) A-5: Beckamine P-138 (trade name; manufactured by Dainippon Ink and Chemicals, Inc.) (2) Carboxylic acid, carboxylic anhydride B -1: Maleic anhydride B-2: Itaconic acid B-3: Adipine B-4: Trimellitic anhydride B-5: Endomethylenetetrahydrophthalic anhydride (3) Phenolic resin C-1: Priofen TD-447 ( Product name: Dainippon Ink and Chemicals, Inc. (4) Alkyd resin D-1: Beckosol J-510 (Brand name: Dainippon Ink and Chemicals, Inc.) (5) Titanium oxide E-1: Rutile Type oxidation R-820 (trade name; manufactured by Ishihara Sangyo Co., Ltd.) (6) Silicon oxide F-1: hydrophobic silica gel R-212 (trade name; manufactured by Nippon Aerosil Co., Ltd.) [Formation of intermediate layer] outer diameter 30 mm , Inner diameter 28mm, length 2
60.5 mm, 1.0 .mu.m surface roughness in maximum height R _{ma x}
An intermediate layer is formed on the aluminum cylinder. Using the materials A to F described above, coating solutions T-1 to T-6 of Examples having compositions as shown in Table 1 were prepared, and the coating solutions were respectively applied onto the aluminum cylinders by the dip coating method. After being applied and dried by touch with a finger, it was baked and cured under the conditions shown in Table 2 to form intermediate layers U-1 to U-6 of the examples shown in Table 2.

For comparison, coating solutions t-1 and t-2 of comparative examples having the compositions shown in Table 1 were prepared, and these coating solutions were applied on the above aluminum cylinders by the dip coating method, After being dried to the touch, it was baked and cured under the conditions shown in Table 2 to form intermediate layers u-1 and u-2 of Comparative Examples as shown in Table 2.

[0028]

[Table 1]

[0029]

[Table 2]

[Production of Photoreceptor] X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals Co., Ltd .; trade name "First Gane Blue 8120B") was placed on each aluminum cylinder provided with the intermediate layer as described above. ) 1 part by weight, vinyl chloride copolymer resin (manufactured by Nippon Zeon Co., Ltd .; trade name "MR-11"
0 ") 1 part by weight was dispersed by a paint shaker together with 100 parts by weight of methylene chloride to carry out dip coating to form a charge generation layer having a dry thickness of 0.2 µm. Subsequently, a polycarbonate resin (manufactured by Mitsubishi Gas Chemical Co., Inc .; trade name "UPILON PCZ-30"
0 ") 10 parts by weight and 10 parts by weight of N, N-diethylaminobenzaldehyde diphenylhydrazone dissolved in 80 parts by weight of tetrahydrofuran are applied by dip coating to form a charge transfer layer having a dry thickness of 20 µm. Also, each photoconductor of Comparative Examples 1 and 4 was produced.

[Evaluation of Photoreceptor] The photoconductor characteristics of each of the photoconductors thus produced were evaluated by a photoconductor process tester. The photoconductor was attached to the tester and the peripheral speed was 78.5.
While rotating at a speed of mm / sec, it is charged to −600 v by a corotron, and the potential when no light is irradiated is defined as the dark part potential V ₀ . After that, the potential when left in the dark for 5 seconds is measured, and the potential holding ratio V _K5 (%) during that period is obtained. Then, wavelength 7
Irradiation with light having a wavelength of 80 nm and an irradiance of ² μW / cm ²
The potential after 2 seconds is defined as the bright portion potential V _i . further,
Let the potential after irradiation for 1.5 seconds be the residual potential V _r . The process of charging and exposing in one cycle as described above
After repeating 10,000 times, the characteristics of the photoconductor were measured at the initial stage (first time) and after repeating 10,000 times. The results are shown in Table 3.

[0032]

[Table 3]

As can be seen from Table 3, the photoconductors of Comparative Examples 1 and 2 which did not contain ferric chloride in the intermediate layer had a high residual potential and poor repeatability. Furthermore, the characteristics of these photoconductors are measured in a low temperature and low humidity environment (LL; temperature: 10 ° C., relative humidity: 50).
%), High temperature and high humidity environment (H, H; temperature 35 ° C, relative humidity 8
5%) to examine its environmental dependence. The results are shown in Table 4.

[0034]

[Table 4]

As is clear from Table 4, those in which the intermediate layer does not contain ferric chloride have large fluctuations in V ₀ and V _i due to environmental changes. Next, these photoconductors were attached to a laser beam printer (manufactured by Hewlett-Packard Co .; trade name "Laser Jet III"), and a low temperature and low humidity environment (L.
L), normal temperature and normal humidity environment (NN; temperature 25 ° C, relative humidity 5)
0%) and high-temperature and high-humidity environment (H.H.) were used for printing, and the image quality at the initial stage and after printing 10,000 sheets was evaluated. The results are shown in Table 5. The image quality is evaluated by 90 mm of the surface of the photoconductor.
The diameter that exists in the area of a square of × 90mm is 0.2mm
The number of black dots is the above, and less than 5 is ◎, 5 or more and less than 20 is ○, 20 or more and less than 50 is △, and 50 or more is ×.
As an ordering.

[0036]

[Table 5]

As can be seen from Table 5, the image quality of the photoconductors of the examples is good, and the image quality of the photoconductors of the comparative examples does not deteriorate even when the environment changes or when printing is repeated. It hardly happens and is stable.

[0038]

According to the present invention, in an electrophotographic photosensitive member comprising an electroconductive substrate on which an intermediate layer is provided and a photosensitive layer is provided thereon, the intermediate layer is formed of amino resin, carboxylic acid, carboxylic acid anhydride, And a cured film containing, as a main component, one obtained by curing ferric chloride doped with one of a mixture of a carboxylic acid and a carboxylic acid anhydride as a catalyst. Such an intermediate layer has a sufficiently low electric resistance,
Moreover, it is stable and hardly changes even if the environment changes significantly. Therefore, it is not necessary to make the film thickness thinner than in the past, and even if the film thickness is made more than one digit thicker than before, the electrical characteristics and image quality are good, and even if it is repeatedly used, there is almost no fluctuation in the electrical characteristics. Moreover, it is possible to obtain an excellent photoconductor whose electric characteristics and image quality are not easily affected by the external environment and are stable. Further, by forming such a thick film intermediate layer, various defects on the surface of the conductive substrate are covered, and a uniform photosensitive layer having few film defects can be formed on the conductive substrate. Even in the case of the function-separated laminated type photoreceptor in which the generation layer and the charge transfer layer are laminated in this order, the thin charge generation layer can be easily formed without causing film formation unevenness. As a result, it is possible to produce with good productivity a photoreceptor that can stably obtain a high-quality image with few image defects.

Claims (1)

[Claims] 1. An electrophotographic photosensitive member comprising an electroconductive substrate having an intermediate layer provided thereon and a photosensitive layer provided thereon, wherein the intermediate layer comprises an amino resin containing a carboxylic acid, a carboxylic acid anhydride, or a carboxylic acid and a carboxylic acid. An electrophotographic photosensitive member comprising a cured film containing, as a main component, one obtained by doping ferric chloride into one obtained by curing any one of a mixture of anhydrides as a catalyst.