JPH1184705A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of image noises such as black spots on an image in any environment by anodically oxidizing the surface of an Al or Al alloy substrate, carrying out a pore sealing treatment, dipping the substrate in a dispersion of fine resin particles dispersed with an anionic surfactant and forming a photosensitive layer on the resultant photoreceptor substrate. SOLUTION: The surface of an Al or Al alloy substrate is anodically oxidized in an acidic bath such as sulfuric acid, a pore sealing treatment is carried out and the substrate is dipped in a dispersion of fine resin particles dispersed with an anionic surfactant. At least a photosensitive layer is formed on the resultant photoreceptor substrate. The fine resin particles are preferably fine particles of one or more resins selected from the group comprising acrylic resin, fluororesin, vinylidene fluoride resin, styrene resin and urethane resin and the average particle diameter of the fine resin particles is preferably regulated to 0.01-1.0 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member used in an electrophotographic apparatus.

[0002]

2. Description of the Related Art The technology of electrophotography has been developed in the field of copiers, and has recently spread rapidly due to high image quality, high speed, and quietness that are incomparable with conventional apparatuses. With the remarkable progress of the data processing system, laser beam printers, digital copiers, and the like have received special attention. The photoreceptor used in these electrophotographic devices generally has a photosensitive layer formed on a conductive photoreceptor substrate such as aluminum or an aluminum alloy,
As a layer configuration, a function-separated laminated configuration in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate is widely used.

[0003] The image forming method used in the above apparatus uses a laser beam as a light source, and forms an image by adhering toner to a portion irradiated with the laser beam in order to use light effectively or increase resolution. The mainstream is to adopt a reversal developing method. According to this developing method, in particular, a charge is injected from a defective portion on a conductive substrate into a photosensitive layer during development due to a change in temperature and humidity in a use environment, and a toner image is formed at a place where a toner image should not be formed. The problem is that image noise called black spots occurs.

In order to improve lubricity, moisture resistance and abrasion resistance, JP-A-63-296051 discloses an image in which holes in an anodized layer are filled with a fluorine-containing organic resin via a silane coupling agent. A retaining member is disclosed. Further, Japanese Patent Application Laid-Open No. 2-99962 reports a technique of sealing an anodic oxide film with a water-repellent substance in order to prevent water from entering into the pores. However, in any of the techniques, unevenness of the resin film easily occurs and the blocking property becomes non-uniform. In particular, under the high temperature and high humidity conditions, it is impossible to completely prevent image noise such as the above black spots. .

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member which does not generate image noise such as black spots on an image under any environment.

[0006]

According to the present invention, there is provided a resin fine particle dispersion comprising a support made of aluminum or an aluminum alloy, the surface of which is subjected to anodizing treatment and sealing treatment, and then fine resin particles are dispersed with an anionic surfactant. The present invention relates to an electrophotographic photoreceptor characterized in that at least a photosensitive layer is provided on a photoreceptor substrate obtained by immersion treatment.

The inventors of the present invention obtained anodizing and sealing the surface of the support and then immersing the surface of the support in a resin particle dispersion in which resin particles were dispersed with an anionic surfactant. It has been found that an electrophotographic photosensitive member obtained by forming at least a photosensitive layer on a photosensitive substrate does not generate image noise such as black spots on an image under any environment.

In general, regarding the electrical characteristics of the anodized layer,
After the anodizing treatment, the ζ potential is positive, and the surface state is still macroscopically positive by performing the sealing treatment.However, since the surface state becomes unstable, it becomes unstable in a subsequent process, for example, a coating process of the photosensitive layer. It is considered that ionic foreign matter is easily embraced in the transporting process and the like, and charges are injected from the ionic foreign matter to generate black spots. The surface instability after the sealing treatment is caused by cutting scratches on the support, the support material, i.e., fine holes generated in the photoreceptor substrate manufacturing process, particularly in the anodizing process, depending on the purity of the aluminum or aluminum alloy, And the additives contained in the sealing agent, it is considered that the stabilization of the surface of the photoconductor substrate can be achieved by the treatment with the resin fine particle dispersion in the present invention, and the resin fine particles are anodized. It is thought that the function of the anodized layer as a charge injection preventing layer can be promoted by being attached to the layer.

The aluminum or aluminum alloy support (hereinafter simply referred to as the aluminum support) used for producing the substrate of the photoreceptor of the present invention is any one which can be conventionally used for an electrophotographic photoreceptor. However, there is no particular limitation. That is, any conventionally known composition and method can be employed for the aluminum composition, the forming method thereof, the surface processing method, and the like. For example, after melting and casting aluminum ingot having a purity of 99.9% or more, it is subjected to a homogenous treatment and extruded to produce a raw tube. After that, as a precision finishing of the surface, after performing ironing and drawing on the obtained raw tube, or ironing and drawing as necessary,
By performing cutting or grinding, the aluminum support used in the present invention can be manufactured.

[0010] The obtained aluminum support may be subjected to a degreasing treatment and an etching treatment prior to the anodizing treatment. The degreasing treatment is performed for the purpose of cleaning the processing liquid applied to the surface for the purpose of effecting oil such as processing the photoreceptor substrate into a desired shape and rust prevention during storage of the substrate, and the method. Is not particularly limited as long as the object is achieved. For example, this is performed by immersing the substrate in an aqueous solution containing a surfactant at 45 to 65 ° C. for 2 to 5 minutes.

The etching treatment for providing the degreased aluminum support is performed in order to remove a natural oxide film formed on the surface of the aluminum support in order to perform a uniform anodic oxidation treatment. Although not particularly limited as long as the object is achieved, it is preferable to be subjected to an acid etching treatment. For example, if the substrate is
0 to 160 g / l nitric acid aqueous solution at 15 to 30 ° C
This is performed by immersion for ~ 5 minutes.

The aluminum support thus treated is subjected to a conventionally known anodizing treatment. Anodizing is generally performed, for example, with chromic acid, sulfuric acid, phosphoric acid,
It is carried out by a known method in an acidic bath such as oxalic acid, boric acid or sulfamic acid. In the present invention, the anodic oxidation treatment in sulfuric acid is most preferable. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / l, preferably 10 to 300 g / l.
0-200 g / l, dissolved aluminum concentration 2-15 g
/ L, liquid temperature is 15-30 ° C, preferably 15-25 ° C,
It is desirable to set the electrolysis voltage in the range of 5 to 20 V, preferably 10 to 20 V. Further, in the present invention, the surface of the above-mentioned support is provided with a current density of 0.3 to 1.0 A / dm.
^2, preferably at 0.6~1.0A / dm ^2, more preferably 0.7~0.8A / dm ² as low current density, 2
The anodic oxidation treatment is preferably performed for a relatively long time of about 5 to 60 minutes.

The thickness of the anodic oxide layer is 1 to 15 μm,
Preferably, it is 2 to 10 μm, more preferably 4 to 8 μm. When the thickness is less than 1 μm, the function of the anodic oxide layer as the charge injection preventing layer is deteriorated. On the other hand, when the thickness exceeds 15 μm, the cost is increased but no further film thickness is required.

In the present invention, the support having the anodic oxide layer formed as described above is preferably subjected to a sealing treatment. This is because the porous portion in the anodized layer is unstable. Generally, the sealing treatment increases the resistance value of the anodized layer and further improves the blocking property.

In the present invention, any of a low-temperature sealing treatment and a high-temperature sealing treatment may be performed as the sealing treatment, and the high-temperature sealing treatment is preferably performed. If desired, a two-stage sealing process for performing each process may be performed.

The high-temperature sealing treatment means a sealing treatment carried out by immersing the anodic oxide layer in a treatment solution at a relatively high temperature, generally 65 ° C. or higher, and other conditions are known. Same as the method. Hot water sealing or steam sealing with pure water, and a high-temperature sealing agent such as nickel acetate, cobalt acetate, lead acetate, nickel-cobalt acetate,
Various modes such as a sealing treatment using a treatment liquid containing a metal salt such as barium acetate can be mentioned, and it is particularly preferable to perform a hot water sealing treatment. If the temperature is 65 ° C. or lower, the degree of sealing on the surface of the support after treatment is reduced, the blocking property is reduced, and fog may occur during printing.

Specifically, when hot water sealing treatment is performed, hot water at a temperature of 65 to 100.degree. C., preferably 90 to 98.degree.
This is performed by immersion for 0 to 60 minutes, preferably 10 to 40 minutes. When performing a steam sealing process, 3.0
Under a steam pressure of ~ 6.0 kg / cm ² for 10 to 30 minutes,
It is preferably carried out by leaving it for 10 to 20 minutes.

When nickel acetate is used as the high-temperature sealing agent, the concentration of nickel acetate is 3 to 20 g / l, preferably 4 to 20 g / l.
An aqueous solution containing 〜12 g / l, adjusted to pH 5.0-6.0, temperature 65-100 ° C., preferably 80-98 ° C.,
This is performed by immersing the support having the anodized layer therein for 10 to 60 minutes. When using a metal salt such as cobalt acetate other than nickel acetate, lead acetate, nickel-cobalt acetate, and barium acetate as a high-temperature sealing agent,
This is performed according to the case where nickel acetate is used.

The low-temperature sealing treatment means a sealing treatment performed by immersing the anodic oxide layer in a treatment liquid at a relatively low temperature, generally 40 ° C. or lower, and other conditions are known. Same as the method. If desired, the treatment liquid may contain, for example, nickel fluoride, red blood salt, or the like as a low-temperature sealing agent.

Specifically, when nickel fluoride is used as the low-temperature sealing agent, the concentration of nickel fluoride is 2 to 7 g /
, preferably 3 to 6 g / l, at pH 5.
5 to 6.0, temperature 25 to 40 ° C, preferably 30 to 35
° C, and the support having the anodized layer
It is carried out by immersion for 10 to 10 minutes, preferably 2 to 5 minutes. When the temperature is 25 ° C. or less, the diffusion of the aqueous solution is poor,
There is a possibility that the degree of sealing on the surface of the support after treatment is reduced, the blocking property is reduced, and fogging occurs during printing. On the other hand, if the temperature exceeds 40 ° C., the adhesiveness between the obtained photoreceptor substrate and the photosensitive layer formed thereon is reduced, the sealing degree is rather reduced, the blocking property is reduced, and fog is caused during printing. Occurs.

When red blood salt is used as the low-temperature sealing agent, the red blood salt is used at a concentration of 3 to 20 g / l, preferably 5 to 15 g / l.
At pH 5.5 to 6.0 at a temperature of 25 to 40.
C., preferably 25 to 30 ° C., and the support having the anodic oxide layer thereon is kept for 1 to 20 minutes, preferably 5 to 30 ° C.
This is performed by soaking for 10 minutes. When the temperature is 25 ° C. or lower, the diffusion of the aqueous solution is poor, the degree of sealing on the surface of the support after treatment is reduced, the blocking property is reduced, and fog may occur during printing. On the other hand, when the temperature exceeds 40 ° C., the adhesiveness between the obtained photoreceptor substrate and the photosensitive layer formed thereon is reduced, the degree of sealing is rather reduced, the blocking is reduced, and fog occurs during printing. .

As the low-temperature sealing treatment, for example, a humidifying sealing treatment may be performed in addition to the case where the low-temperature sealing agent is used as described above. When performing the humidifying sealing process, a relative humidity of 80
It is carried out by leaving at% RH or more and a temperature of 30 to 40 ° C. for 1 to 10 days.

In addition, high-temperature sealing treatment and low-temperature sealing treatment,
In any of the sealing treatment steps, a surfactant may or may not be contained in the treatment liquid for the purpose of improving the wettability of the surface of the support with the treatment liquid. It is preferable that the treatment liquid does not contain a surfactant from the viewpoint of the efficiency of the immersion treatment with the resin particle dispersion containing an anion later. This is because the pore-sealing treatment with a treatment liquid containing no surfactant does not significantly affect the zeta potential of the surface of the support after the treatment, and the potential is likely to be uniform. When a surfactant is contained, the surfactant may be a cationic surfactant, an anionic surfactant, an amphoteric surfactant or a nonionic surfactant. It is preferable to use an amphoteric surfactant or a nonionic surfactant from the viewpoint of the efficiency of the immersion treatment with the resin fine particle dispersion liquid later. If the treatment liquid contains a cationic surfactant, the efficiency of the pore-sealing treatment may decrease, and if the treatment liquid contains an anion surfactant, the subsequent immersion treatment with the resin fine particle dispersion will be more efficient. This is because it is difficult to perform well.

The support having the anodized layer sealed as described above is subjected to a dipping treatment in a resin particle dispersion in which resin particles are dispersed with an anionic surfactant. Thus, it is considered that the surface of the anodic oxide layer is stabilized, and at the same time, the fine resin particles are chemically adsorbed to the anodic oxide layer, thereby promoting the improvement of the function of the anodic oxide layer as the charge injection preventing layer.

The above resin fine particle dispersion comprises at least resin fine particles, an anionic surfactant and a dispersion medium.
In the dispersion, the resin fine particles are uniformly dispersed by the anionic surfactant. Unless uniform dispersion is achieved, the effects of the present invention are hardly obtained. That is, not only is it difficult to obtain the effect of stabilizing the substrate surface, but also it is not possible to obtain uniform blocking properties of the anodic oxide layer in the obtained photoreceptor substrate.

The resin fine particles dispersed in the resin dispersion may be fine particles made of any resin, for example, acrylic resin, fluorine resin, vinylidene fluoride resin, styrene resin and urethane resin. And two or more resin fine particles selected from these resin fine particles may be used as a mixture. Specific examples include polytetrafluoroethylene, polyurethane, polystyrene, polymethyl methacrylate, polyvinylidene fluoride, styrene-methyl methacrylate copolymer, styrene-divinylbenzene copolymer, and the like. It is preferred to use

The fine particles have an average particle size of 0.01 to 1.0 μm.
m, preferably 0.1 to 0.3 μm, and when the average particle size is smaller than 0.01 μm, the blocking property of the fine particle layer to which the fine particles adhere is reduced, which causes black spots. On the other hand, if the average particle diameter is larger than 1.0 μm, the adhesiveness between the obtained photoreceptor substrate and the photosensitive layer formed thereon is reduced, and the sensitivity is reduced particularly in a low-temperature and low-humidity environment, causing fog during printing. .

Such fine resin particles can be produced by any known method, for example, easily and efficiently by an emulsion polymerization method, a soap-free polymerization method or a seed polymerization method.

The fine particles are contained in the fine particle dispersion in an amount of 5 to 30.
g / l, preferably 10-20 g / l. If the amount is less than 5 g / l, the effect of the present invention cannot be obtained. If the amount is more than 30 g / l, the dispersion of the resin fine particles in the liquid becomes insufficient, and the thickness of the resin fine particle layer attached to the anodic oxide layer is uneven. Becomes

The anionic surfactant contained in the dispersion is preferably a compound capable of dispersing the resin fine particles in a dispersion medium described below.
Without limitation, any one can be used. For example, sodium lauryl sulfate, oleyl sulfate, nonylphenyl, dioctyl sodium sulfosuccinate, dioctyl naphthalene sulphonate, sodium acrylate-hydroxyethyl methacrylate copolymer and the like can be mentioned.

Such an anionic surfactant is contained in the fine particle dispersion at a ratio of 1 to 6 g / l. 1g /
When the amount is less than 1 g or more than 6 g / l, the dispersion of the resin fine particles becomes insufficient, the thickness of the resin fine particle layer attached to the anodic oxide layer becomes uneven, and the effect of the present invention is hardly obtained. Also, in order to improve the properties of the resin fine particle layer,
If necessary, an organic acid may be added.

As a dispersion medium, any solvent can be used as long as it does not dissolve the resin fine particles and can disperse the resin fine particles through the dispersion medium due to the presence of the anionic surfactant. Can be. For example, water, methanol, ethanol, isopropyl alcohol and the like can be mentioned, and water is preferably used.

Between each of the above-mentioned processing steps, it is preferable to provide an auxiliary processing step such as washing with tap water or pure water in order to perform the processing of the next step efficiently and reliably.

A photosensitive layer is formed on the photoreceptor substrate obtained as described above by a known method. A form in which a charge generation layer and a charge transport layer are sequentially laminated as a photosensitive layer,
The charge transport layer and the charge generation layer may be sequentially stacked, or may be any of a single layer type including a charge transport material and a charge generation material.Hereinafter, a charge generation layer and a charge transport layer are used as a photosensitive layer. A case of manufacturing the photoconductors in the form of sequentially laminated layers will be described.

The charge generation layer may be formed by vacuum deposition of the charge generation material, or by dissolving the charge generation material in a solvent such as an amine, or by coating the pigment in an appropriate solvent or, if necessary, a solution in which a binder resin is dissolved. The coating liquid prepared by dispersing is applied and dried to form a charge generation layer. A solution containing a charge transport material and a binder resin is further applied thereon and dried to form a charge transport layer.

Examples of the charge generating material used in the photoreceptor of the present invention include bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes, styryl dyes, and pyrylium dyes. Organic substances such as dyes, azo dyes, quinacridone dyes, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indathrone pigments, squarylium pigments, and phthalocyanine pigments are exemplified. In addition, any material that absorbs light and generates charge carriers with extremely high efficiency can be used.

The charge transporting material used in the photoreceptor of the present invention is preferably an organic substance, such as a hydrazone compound, a pyrazoline compound, a styryl compound, a triphenylmethane compound, an oxadiazole compound, a carbazole compound, a stilbene compound, Various materials such as an enamine compound, an oxazole compound, a triphenylamine compound, a tetraphenylbenzidine compound, and an azine compound can be used.

The binder resin used in the production of the photoreceptor as described above is electrically insulating, and is measured by 1 × 10 ¹²
It is desirable to have a volume resistance of Ω · cm or more. For example, a binder such as a thermoplastic resin, a thermosetting resin, a photocurable resin, or a photoconductive resin known per se can be used. Specifically, polyvinyl butyral resin, polyester resin, polyamide resin, acrylic resin, ethylene-vinyl acetate resin, ion-crosslinked olefin copolymer (ionomer), styrene-butadiene block copolymer, polycarbonate resin, vinyl chloride-vinyl acetate Thermoplastic resins such as copolymers, cellulose esters, polyimide resins, and styrene resins; epoxy resins, urethane resins, silicone resins, phenolic resins, melamine resins,
Thermosetting resins such as xylene resins, alkyd resins, and thermosetting acrylic resins; photocurable resins; and photoconductive resins such as polyvinylcarbazole, polyvinylpyrene, polyvinylanthracene, and polyvinylpyrrole. Used alone or in combination of two or more. When the charge transporting material is a polymer charge transporting material that can be used as a binder, it is not necessary to use another binder resin.

The photoreceptor of the present invention can be used together with a binder resin together with a plasticizer such as halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate, O-terphenyl, chloranil, tetracyanoethylene, 2,4,7.
An electron withdrawing sensitizer such as trinitrofluorenone, 5,6-dicyanobenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride, 3,5-dinitrobenzoic acid, methyl violet, rhodamine B, cyanine dye, pyrylium salt And sensitizers such as thiapyrylium salts.

The photoreceptor of the present invention may have a structure in which an intermediate layer is provided on the above-described anodized layer. As a material used for the intermediate layer, a polyimide resin, a polyamide resin,
Nitrocellulose resin, polyvinyl alcohol resin, phenol resin, melamine resin, epoxy resin and the like are suitable. The film thickness is 0.1 to 30 μm, preferably 1 to 30 μm
m, more preferably 1 to 20 μm.

Further, in the photoreceptor of the present invention, a surface protective layer may be provided on the above-mentioned photosensitive layer. As a material used for the surface protective layer, a polymer such as an acrylic resin, a polyarylate resin, a polycarbonate resin, or a urethane resin as it is, or a material in which a low-resistance compound such as tin oxide or indium oxide is dispersed is suitable. Further, an organic plasma polymerized film can be used as the surface protective layer. The organic plasma polymerized film may optionally contain oxygen, nitrogen, halogen, and atoms of groups 3 and 5 of the periodic table.

The photoreceptor of the present invention can be effectively used in both the reversal developing system and the regular developing system while selecting the photosensitive layer, while obtaining the effects of the present invention. It is particularly preferred to use.

The apparatus into which the photoreceptor manufactured in this manner is incorporated is not particularly limited, and may be any of a full-color, color, or single-color copying machine, a printer, a reader printer, and the like. Also, the shape of the photoconductor is not particularly limited,
Examples include a drum shape, a belt shape, and a plate shape. The present invention is described in more detail by the following examples.

[0044]

EXAMPLE 1 JIS 5657 cylindrical aluminum alloy (outer diameter 100
(mm, length 350 mm, thickness 2 mm) was cut with a cutting tool using natural diamond as a cutting blade. This is treated with a surfactant (Top Alclean 1) as a degreasing agent.
61 (manufactured by Okuno Pharmaceutical Co., Ltd.) 60 ± 5 using 30 g / l
A degreasing treatment was performed at 5 ° C. for 5 minutes, followed by washing with running water. 100g
After etching for 2 minutes in a 1 / l nitric acid solution, the substrate was washed with running water. Next, anodic oxidation treatment was performed at a current density of 1 A / dm ^{2 at} a liquid temperature of 20 ° C. for 25 minutes using 150 g / l sulfuric acid as an electrolytic solution to form an anodized layer having a thickness of 7 μm. Thereafter, the support was washed with running pure water and then sealed with pure boiling water at 98 ° C. for 15 minutes to wash with pure water.

Then, a resin fine particle dispersion (Tople Blend: manufactured by Okuno Pharmaceutical Co., Ltd.) in which polytetrafluoroethylene fine particles having an average particle size of 0.1 to 0.2 μm were dispersed with an anionic surfactant, was dispersed in this dispersion. A treatment solution diluted with pure water was prepared so that the solution concentration became 100 ml / l, and the support subjected to the above sealing treatment was immersed in this treatment solution at 30 ° C. for 5 minutes, and washed with pure water. After drying, a photoreceptor substrate was obtained.

Next, a photosensitive layer was formed on the photoreceptor substrate thus obtained in the following manner. 1 part by weight of τ-type metal-free phthalocyanine (Liophoton TPA-909: manufactured by Toyo Ink Mfg. Co., Ltd.) and 0.5 parts by weight of a polyvinyl butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) together with 50 parts by weight of tetrahydrofuran (THF) It was dispersed by a sand mill. The resulting phthalocyanine-based dispersion was applied to the above-mentioned photoreceptor substrate to a thickness of 0.3 μm after drying.
To form a charge generation layer.

The following formula:

Embedded image

Benzyldiphenyl compound 10 represented by the following formula:
Parts by weight and 10 parts by weight of a polycarbonate resin (K-1300, manufactured by Teijin Chemicals Ltd.) in 180 parts by weight of dichloromethane was coated on the above-mentioned charge generation layer and dried to form a charge transport layer having a thickness of 24 μm. Was formed to produce an electrophotographic photosensitive member.

Comparative Example 1 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the support subjected to the sealing treatment was used as a photoreceptor substrate without being immersed in a processing solution in which fine resin particles were dispersed. Was prepared.

Example 2 A resin fine particle dispersion in which polytetrafluoroethylene fine particles were dispersed with an anionic surfactant (Tople blend:
Average particle size 0.2 to 0.3 μm instead of Okuno Pharmaceutical Co., Ltd.)
Resin dispersion liquid (Anodal SP-1: Clariant Co., Ltd.) in which polyurethane fine particles were dispersed with an anionic surfactant was used.
An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that the temperature was set to 10 ° C. and the processing time was changed to 10 minutes instead of 5 minutes.

(Evaluation of black spots) Each of the electrophotographic photosensitive members obtained in Example 1 and Comparative Example 1 was mounted on a full-color copying machine (CF900; manufactured by Minolta Co., Ltd.), and pure black toner was supplied to all four developing units. A white solid image was copied by superimposing four times with black toner, and the number of black spots (black spots) in an image of 25 mm ² at the initial stage and after copying 1,000 sheets was visually counted and evaluated according to the following.
The copying was performed at low temperature and low humidity (10 ° C., 15% RH), medium temperature and medium humidity (23 ° C., 45% RH) and high temperature and high humidity (30% RH).
(° C., 85% RH) in each environment, and evaluated in all cases. ：: 14 or less; Δ: 15 to 29; ×: 30 or more.

The results of these evaluations are shown in Table 1 below.

[Table 1]

[0053]

According to the present invention, it is possible to provide an electrophotographic photosensitive member which does not generate image noise such as black spots on an image.

Claims (3)

[Claims] An anodizing treatment and a sealing treatment on the surface of a support made of aluminum or an aluminum alloy, followed by immersion treatment in a resin fine particle dispersion in which resin fine particles are dispersed with an anionic surfactant. An electrophotographic photoreceptor comprising a photoreceptor substrate provided with at least a photosensitive layer. 2. The resin fine particles are fine particles made of one or more resins selected from the group consisting of an acrylic resin, a fluorine resin, a vinylidene fluoride resin, a styrene resin and a urethane resin. The electrophotographic photosensitive member according to claim 1, wherein 3. The resin fine particles have an average particle size of 0.01 to 1.0.
3. The electrophotographic photosensitive member according to claim 1, wherein the thickness of the electrophotographic photosensitive member is μm.