JP2001134001A - Method for producing substrate of electrophotographic photoreceptor, substrate of electrophotographic photoreceptor and electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a substrate of an electrophotographic photoreceptor having a uniform coating with little thickness deviation by improving anodic oxidation carried out as surface treatment and to obtain an electrophotographic photoreceptor having good printing quality with the substrate. SOLUTION: When plural cylindrical aluminum substrates are put in an electrolytic cell and anodic oxide coatings of aluminum are formed on the surfaces of the substrates by anodic oxidation to produce substrates of electrophotographic photoreceptors, the distance between the centers of the cylindrical aluminum substrates is made >=4 times the radius of the substrates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of an electrophotographic photosensitive substrate made of aluminum having an aluminum anodic oxide film (hereinafter, also simply referred to as "film") on its surface (hereinafter, also simply referred to as "substrate"). The present invention relates to a method, an electrophotographic photoreceptor substrate, and an electrophotographic photoreceptor using the same (hereinafter, also simply referred to as “photoreceptor”).

[0002]

2. Description of the Related Art The technology of electrophotography has been developed in the field of copying machines, and has recently been applied to laser printers and the like. A photoreceptor used in an electrophotographic apparatus is formed by providing a photoconductive layer on a conductive substrate surface. As the material of the photoconductive layer, those using an organic material are mainstream,
As a layer configuration, a function-separated structure (laminated type) in which an undercoat layer, a charge generation layer, and a charge transport layer are sequentially laminated on a substrate is generally used.

As a first undercoat layer (UCL: Under Cort Layer) provided on a substrate surface, a resin material represented by polyamide or melamine is used, and an anodic oxide film is formed on an aluminum substrate surface. In some cases, the latter is generally advantageous in reliability under a high-temperature and high-humidity environment.

[0004] The light source used in the printer is 780n.
The mainstream is a semiconductor laser having a wavelength of m, and this light source has a single wavelength and therefore has excessive coherence. On the other hand, an anodic oxide film of aluminum has a feature that almost all light having a wavelength of 780 nm is transmitted. Therefore, when a photoreceptor using an aluminum substrate having an anodized film is applied to a printer using a semiconductor laser as a light source, reflected light at the interface between the anodized film and aluminum and reflected light at the surface of the anodized film. And the interference effect between them becomes remarkable. Such interference does not cause any particular problem when the anodic oxide film formed on the substrate is uniform.

[0005]

However, due to the nature of the anodic oxidation treatment, it is difficult to form the film thickness completely completely, and the surface of the substrate having the anodic oxide film usually has a certain thickness deviation. Exists. If the film thickness of the film has a deviation greater than or equal to a predetermined value in the substrate, the interference state of the reflected light at both interfaces is different in the substrate, so that there are portions that are strengthened by interference and portions that are weakened by interference, This causes uneven density (interference fringes) at the time of printing, which causes a problem.

Accordingly, an object of the present invention is to realize an electrophotographic photoreceptor substrate having a uniform film with a small thickness deviation by improving anodizing treatment performed as a surface treatment.
Another object of the present invention is to provide an electrophotographic photoreceptor having good printing quality using the same.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, in order to suppress the above-mentioned interference effect on the substrate surface, it is necessary to calculate from the optical constants and the surface roughness of the substrate. It is necessary to suppress the film thickness deviation of the film to a predetermined value or less, for that, since the film thickness of the anodic oxide film is substantially determined by the current density and the conduction time,
By performing anodic oxidation treatment under specific electrolytic conditions to make the current density uniform over the entire substrate, it has been found that a film having a uniform film thickness can be formed,
The present invention has been completed.

That is, in order to solve the above-mentioned problems, a method of manufacturing a photoreceptor substrate for electrophotography according to the present invention comprises: immersing a plurality of cylindrical aluminum substrates in an electrolytic bath; In the method for manufacturing an electrophotographic photosensitive member substrate on which an aluminum anodic oxide film is formed, a distance between centers of the cylindrical aluminum substrates is set to be four times or more a radius of the aluminum substrate.

Further, the electrophotographic photoreceptor substrate of the present invention comprises:
It is manufactured by the above-mentioned manufacturing method, and the thickness deviation of the aluminum anodic oxide film is 0.5 μm or less.

Furthermore, an electrophotographic photoreceptor of the present invention is characterized in that the electrophotographic photoreceptor substrate is used.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing a photoreceptor substrate for electrophotography according to the present invention, a substrate produced by this production method, and a photoreceptor for electrophotography using this substrate will be specifically described.

The electrophotographic photoreceptor substrate of the present invention is an aluminum substrate serving not only as an electrode of the electrophotographic photoreceptor but also as a support for other layers, and has a cylindrical shape. . Also, as aluminum material,
Conventional materials such as JIS6063 and 3003 may be used, and there is no particular limitation.

In the present invention, an anodic oxide film is formed on the surface of such an aluminum substrate. The surface roughness of the aluminum substrate before the anodic oxidation treatment is performed to form the aluminum anodic oxide film is preferably 0.1 mm. 3 ~
3.0 s, more preferably in the range of 0.3 to 1.5 s.

In the anodic oxidation treatment according to the present invention, as shown in FIG. 1, the distance a between the centers of the substrates 2 to be processed in the electrolytic cell 1 during energization is set to be at least four times the substrate radius r. The processing is performed by disposing each substrate 2 to be processed. As shown in FIG. 2, the substrate 2 to be processed in the electrolytic cell is placed on the electrode 3. Therefore, if the electrode 3 can be set so that the distance between the substrates is as described above, a known method is used. An electrolytic cell can be used and is not particularly limited. For example, as shown in FIG. 3, 15 substrates × 2 stages of substrates 2 to be processed are arranged in the electrolytic cell 1 and ten cathodes 4 made of lead or the like are installed to perform the processing. As the cathode 4, for example, FIG.
A shape as shown in FIG. FIG. 5 shows an AA cross section in FIG. The anodic oxidation treatment according to the present invention is not particularly limited as to other treatment conditions, but is preferably performed under the following treatment conditions.

As the acid used in the electrolytic treatment in the anodic oxidation treatment, a conventional acid can be used.
Preferably, sulfuric acid is used. The condition of the electrolyte is
It is preferable that the concentration of free sulfuric acid is 150 to 200 g / l, the concentration of aluminum ion is 1 to 12 g / l, and the temperature is 15 to 25 ° C, particularly 20 ± 0.5 ° C.

The thickness of the anodic oxide film can be appropriately set as desired, and is not particularly limited. Further, since the film thickness of the film is determined by the current density and the processing time as described above, the current density and the energizing time during the processing can be appropriately set according to the desired film thickness, and there is no particular limitation. , Preferably a current density of 0.5 to 1.5 A / dm
² , the energization time is in the range of 15 to 35 minutes. It is preferable to use a lead plate or a carbon plate which is not affected by sulfuric acid as the electrode.

In order to obtain the electrophotographic photoreceptor substrate of the present invention, it is necessary to perform a sealing treatment after the formation of the film. The condition is that either nickel acetate or pure water is used as a sealing treatment agent. Even when used, preferably at 60 to 95 ° C,
More preferably at a temperature of 70-90 ° C., preferably 10
The range is within 30 minutes. Examples of the surfactant used for the pore-sealing treatment include a phosphoric acid ester, a formaldehyde condensate of naphthalene sulfonic acid, a formaldehyde condensate of naphthalene sulfonic acid of bisphenol A, and a preferable concentration thereof is 0.5 to 20 ml. / L, more preferably 1 to 5 ml / l.

The thickness deviation of the aluminum anodic oxide film on the substrate subjected to the above-described anodic oxidation treatment is 0.5 μm or less, which makes it possible to obtain a photosensitive member having good print quality.

Next, specific embodiments of the photoreceptor of the present invention will be described below. The photoreceptor of the present invention only needs to use the above-described photoreceptor substrate of the present invention. Is not particularly limited.

The photoreceptor generally includes a negatively-charged function-separated laminated photoreceptor, a positively-charged function-separated laminated-type photoreceptor, and a positively-charged single-layer type photoreceptor. This will be specifically described by taking a mold type photoconductor as an example. The negatively charged function-separated laminated photoreceptor has a configuration in which a photosensitive layer including a charge generation layer and a charge transport layer is laminated on a conductive substrate via an undercoat layer.

The charge generating layer is formed by vacuum-depositing an organic photoconductive substance or applying a material in which particles of the organic photoconductive substance are dispersed in a resin binder, and receiving light to generate a charge. . It is important that the generated charge is injected into the charge transport layer at the same time as the charge generation efficiency is high, the electric field dependence is small, and the injection is good even at a low electric field. Examples of the charge generation material used for such a charge generation layer include:
Examples include various phthalocyanine compounds, azo compounds, polycyclic quinone compounds, and derivatives thereof.

Examples of the binder for the charge generation layer include polycarbonate, polyester, polyamide, polyurethane, epoxy, polyvinyl butyral, polyvinyl acetal, phenoxy resin, silicone resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, and formal. A resin, a cellulose resin, a copolymer thereof, a halide thereof, and a cyanoethyl compound can be used.

The amount of the charge generating substance to be used is preferably in the range of 5 to 500 parts by weight, more preferably 10 to 100 parts by weight, based on 10 parts by weight of the resin binder. Also,
The thickness of the charge generation layer is preferably from 0.1 to 5 μm, more preferably 1 μm or less.

The charge transport layer is a coating film made of a material in which an organic charge transport material is dispersed in a resin binder. In a dark place, the charge of the photoreceptor is retained as an insulator layer. It has a function of transporting injected charges. As the charge transporting substance in the charge transporting layer, various hydrazones, styryls, diamines, butadiene, indole compounds, and mixtures thereof can be used.

Examples of the binder for the charge transport layer include polycarbonate, polystyrene, and polyphenylene ether acrylic resin. In terms of film strength and printing durability, bisphenol A type, bisphenol Z type, etc. A coalesced polycarbonate is preferably used. Further, the thickness of the charge transport layer is preferably in the range of 10 to 50 μm.

The charge generation layer and the charge transport layer include:
An electron-accepting substance, an antioxidant, a light stabilizer and the like can be added as needed for the purpose of improving sensitivity, reducing residual potential, or improving environmental resistance or stability against harmful light. Further, a surface protective layer may be provided on the photosensitive layer, if necessary, for the purpose of improving environmental resistance and mechanical strength. As such a surface protective layer, a layer that does not significantly hinder light transmission is preferable.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. Examples 1 to 4 An aluminum tube (A6063 material) was cut to a desired size (diameter: 30 mm, total length: 254 mm) with a lathe, and the surface roughness was finished to about Rmax = 1.0 μm and Ra = 0.1 μm ( The cutting oil used is Metalwork ED manufactured by Nippon Oil Co., Ltd.). Then, a degreasing agent (Top Alclean 1)
01: Okuno Pharmaceutical Co., Ltd.) for 3 minutes (40 g / l,
(60 ° C.) After degreasing, it was rinsed with pure water.

The electrolysis conditions were sulfuric acid (free sulfuric acid 180 g / l,
2 g / l of dissolved aluminum and a temperature of 20 ° C.) were used as the electrolytic solution. The energization is performed when the distance a between the substrate centers shown in FIG.
Using a titanium electrode manufactured to have a thickness of 0, 70, 80, or 100 mm, a current density of 0.74 A / dm ² was used.
Minutes.

Thereafter, after sufficient washing with water, a sealing treatment (top seal E110: manufactured by Okuno Pharmaceutical Co., Ltd.) was performed for 1
This was performed for 4 minutes (85 ° C., 5 ml / l) and washed with water.

The thickness deviation of the anodic oxide film of the obtained substrate was evaluated by the difference between the maximum value and the minimum value at three points in the circumferential direction and three points in the length direction (a total of nine points). The evaluation method used a confocal optical system laser microscope (manufactured by Lasertec Co., Ltd.).

Thereafter, the substrate is washed with an alkali detergent (Castrol 450: manufactured by Castrol Co., Ltd., concentration 2% by weight, normal temperature), and is made of a dispersion of γ-type titanyl phthalocyanine and a vinyl chloride vinyl acetate copolymer. A charge generation layer (CGL) is formed by applying a coating liquid and heating and drying, and a coating liquid composed of a mixture of a hydrazone-based conductive agent, a polycarbonate resin and an antioxidant is applied, and then heated and dried to form a charge transporting layer (CTL). ) To prepare a photoreceptor, and its printing performance was evaluated using a printing apparatus (PCPR2000: manufactured by NEC) using a laser beam having a wavelength of 780 nm as a light source.

Examples 5 to 8 Examples 1 to 4 were repeated except that electrodes made of aluminum were used.
The substrate was processed in the same manner as described above to produce a photoreceptor, and the film thickness deviation and printing performance were evaluated.

Comparative Examples 1 to 4 Substrates were processed in the same manner as in Examples 1 to 4 to prepare photoconductors, except that the distance between the centers of the substrates was 40, 45, 50 and 55 mm. And the printing performance were evaluated.

Comparative Examples 5 to 8 Comparative Examples 1 to 4 were performed except that electrodes made of aluminum were used.
The substrate was processed in the same manner as described above to produce a photoreceptor, and the film thickness deviation and printing performance were evaluated. The results are shown in Table 1 below.

[0035]

[Table 1]

As shown in Table 1, in Examples 1 to 8 in which the distance between the centers of the substrates was set to four times or more the substrate radius (15 mm) and the electrolytic treatment was performed, the thickness deviation was suppressed to 0.5 μm or less. The printing quality was also good. On the other hand, in Comparative Examples 1 to 8 in which the processing was performed at less than four times the substrate radius (15 mm), the film thickness deviation was 0.5 μm or more, and printing trouble (interference fringes) due to laser interference was observed.

[0037]

As described above, according to the present invention, in an aluminum substrate having an anodized film used for an electrophotographic photoreceptor, the distance between the centers of the substrates in the anodizing treatment is reduced. By arranging at intervals of at least four times the substrate radius, a good photoreceptor substrate having a thickness variation of the anodic oxide film suppressed to 0.5 μm or less and having no uneven printing density due to laser light interference. It was possible to manufacture a photoreceptor having good printing performance by using the same.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an arrangement of a photoconductor substrate for electrophotography at the time of anodizing treatment according to the present invention.

FIG. 2 is a schematic diagram illustrating an arrangement relationship between a substrate and electrodes.

FIG. 3 is a plan view showing an example of an electrolytic cell.

FIG. 4 is a schematic diagram showing an example of a cathode in an electrolytic cell.

FIG. 5 is a sectional view of the cathode shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolyzer 2 Substrate to be processed 3 Electrode 4 Cathode

Claims (7)

[Claims] 1. A method of manufacturing an electrophotographic photoreceptor substrate, wherein a plurality of cylindrical aluminum substrates are immersed in an electrolytic cell and an aluminum anodic oxide film is formed on the surface by anodizing treatment by electrolysis. A method of manufacturing a photoreceptor substrate for electrophotography, wherein the distance between the centers of the substrates is at least four times the radius of the aluminum substrate. 2. The current density in the electrolysis is 0.5 to
^{2. The} method for producing a photosensitive substrate for electrophotography according to claim 1, wherein the electric current is 1.5 A / dm < ² > and the energizing time is 15 to 35 minutes. 3. The method according to claim 1, wherein sulfuric acid is used as the electrolytic solution. 4. A free sulfuric acid concentration of 150 to 200 g / l.
And the concentration of dissolved aluminum ions is 1 to 12 g / l
4. The method for producing an electrophotographic photosensitive member substrate according to claim 3, wherein 5. The method for producing a photosensitive substrate for electrophotography according to claim 1, wherein the temperature of the electrolyte is 15 to 25 ° C. 6. A method for manufacturing a photoconductor substrate for electrophotography according to claim 1, wherein the aluminum anodic oxide film has a thickness deviation of 0.5 μm or less. Electrophotographic photosensitive substrate. 7. A photoconductor for electrophotography, wherein the photoconductor substrate for electrophotography according to claim 6 is used.