JPH0328704B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for manufacturing an electrophotographic photoreceptor, and particularly to a method for manufacturing a functionally separated type electrophotographic photoreceptor.

(Prior Art) A conventional functionally separated photoreceptor using an organic pigment or an organic dye as a charge generation layer has a charge generation layer 12 on a conductive substrate 11 made of aluminum or the like, as shown in FIG.
A thin film of an organic pigment or organic dye is formed by a vacuum evaporation method or a solution coating method, and an organic charge transport layer 13 is formed on this charge generation layer 12 by a solution coating method such as a doctor blade.

The conductive substrate 11 used in this type of functionally separated photoreceptor is generally made of an aluminum material that has been anodized, and the anodized film is sealed. Furthermore, the charge generation layer 12 is made of a phthalocyanine-based or merocyanine-based organic material formed by vacuum evaporation, and has a thickness of 0.1 to 100 ml.
A thin film of 0.5 μm, or a thin film formed by solution coating such as the doctor blade method using an organic material such as chlorodiane blue, squaryllic acid derivative, or triphenylmethane dye dissolved in an organic solvent, and its dry thickness is 1~3μ
m is normal. The charge transport layer 13 is a thin film with a dry thickness of 10 to 20 μm formed by solution coating of a solution of polyvinylcarbazole (PVK), a pyrazoline derivative mixed with a polycarbonate resin, or a hydrazone derivative mixed with an acrylic resin.

When manufacturing a photoreceptor having the structure shown in FIG. 1, the vacuum evaporation method is particularly used to form the charge generation layer 12, and even an extremely thin uniform film of 0.1 to 0.5 μm can be easily obtained. This method requires the use of a large-scale vacuum device, which is very complicated and requires a large amount of power, resulting in high costs. Furthermore, in the solution coating method, since the charge generator material alone does not have the ability to form a film, it is necessary to add a small amount of binding and film-forming resin material. However, the charge generation layer formed by this method tends to be thicker than 1 μm because it is very difficult to create a uniform extremely thin film of about 0.1 μm. The electrophotographic properties of the photoreceptor manufactured using this method are such that due to the addition of resin materials and the large film thickness, the residual potential is large, and due to the induction effect, it takes a considerable amount of time for the photoreceptor to stabilize from the beginning of use. There are disadvantages in that the required development occurs, and because the film is thick, the strength of this charge generating layer is low and it is easy to peel off from this part.

(Disclosure of the Invention) Therefore, as a result of extensive studies, the present inventors found that
An aluminum substrate with an anodized film formed on its surface by anodizing treatment can easily adsorb dyes or pigments as charge generating materials while remaining active without sealing to form an extremely thin charge generating layer. The present invention was achieved based on the knowledge that this method is a method.

That is, the present invention provides a functionally separated electrophotographic photoreceptor in which a charge generation layer is formed on a conductive substrate and a charge transport layer is formed thereon, in which an aluminum substrate is used as the conductive substrate, and the aluminum substrate is forming an anodized film on the surface of the substrate by anodizing, and immersing the surface of the substrate in a dye or pigment solution without performing a sealing treatment on the anodic oxide film,
This method of manufacturing an electrophotographic photoreceptor is characterized in that a dye or pigment is adsorbed onto the surface of the substrate to form a charge generation layer.

Examples of organic dyes or pigments that can be used as charge-generating materials include anthraquinone, nitroso, monoazo, bisazo, xanthene, pyrazolone, and triphenylmetal dyes.

(Example) Examples of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic process diagram of the example. As shown in this figure, first, the aluminum substrate was degreased (Step A). This degreasing treatment was performed twice. First, the aluminum substrate is immersed in 10% sulfuric acid to which a surfactant has been added at 50°C for the first degreasing process, then washed with water, and then immersed in a sodium hydroxide solution for the second degreasing process. I went to After that, it was immersed in dilute nitric acid and washed with water. After degreasing the aluminum substrate in this way, electrolysis was carried out in 10% sulfuric acid at a current density of 2 A/dm ² with the aluminum substrate as the anode (Step B). The rate of formation of the anodic oxide film at this time was 0.3 μm/min. After electrolyzing the aluminum substrate for 70 minutes to form an anodic oxide film of about 20 μm in this manner, the aluminum substrate was washed with water and dried. After this, the aluminum substrate was stored in a vacuum.

Next, the aluminum substrate stored in vacuum was immersed in a solution (processing liquid) of the charge generation layer material.
(Step C). Here, as a charge generating material, the following general formula is used. The central metal is Al (aluminum), and one Cl (chlorine) is bonded to this Al, and a portion of the hydrogen in the benzene ring around the phthalocyanine ring is converted into Cl.
(hereinafter abbreviated as AlClPc(Cl))
was used. Note that this AlClPc (Cl) was synthesized by the phthalonitrile method and sufficiently purified. Further, a treatment solution was prepared by dissolving 0.5 wt% of this AlClPc (Cl) in anhydrous ethyl alcohol, and an aluminum substrate having an active surface that had been anodized was immersed in this treatment solution for 10 minutes. At this time, the temperature of the treatment liquid was 35°C. In this way, AlClPc (Cl) was adsorbed onto the aluminum substrate to form a charge generation layer.

Thereafter, the aluminum substrate on which AlClPc (Cl) was adsorbed was removed from the treatment solution and thoroughly dried. The thickness of the AlClPc (Cl) film formed on this dried aluminum substrate was about 0.1 μm.

Thereafter, the aluminum substrate on which the charge generation layer was formed was exposed to tetrahydrofuran (THF) vapor for 24 hours for solvent treatment (Step D).
Next, a charge transport layer was formed by coating a THF solution of PVK using a doctor blade so that the dry thickness was 16 μm (Step E).

Finally, the photoreceptor prepared in this way was heated to 80°C.
The solvent was almost completely removed by heating in an air constant temperature bath for 3 hours.

As described above, in the embodiment, an extremely thin charge generation layer can be easily formed by simply immersing an anodized aluminum substrate in a treatment solution containing a dye or pigment.

In addition, as a result of measuring the charge characteristics of the electrophotographic photoreceptor produced according to the example, the corona voltage was -6KV.
When , the initial surface potential (V ₀ ) is −600V, and this
The exposure amount required to halve V ₀ was 1.5 cm ² /μJ when using 800 nm irradiation light, indicating extremely high sensitivity. In addition, the residual potential was small at less than 50V. For comparison, an aluminum substrate was prepared in which an AlClPc (Cl) charge generation layer was anodized using the conventional vacuum evaporation method instead of the charge generation layer formation method using the treatment solution of this example. 0.1μm on top
After the formation, a photoreceptor was prepared in exactly the same manner as shown in FIG. 2, and its charging characteristics were measured. The result is that when the corona voltage is -6KV, the initial surface potential (V ₀ ) is
is −700V, and the exposure amount required to halve this V ₀ is 2.0 when using 800nm irradiation light.
It was cm ² /μJ. Moreover, the residual potential was 30V or less. As is clear from this, the charging characteristics of the two types of photoreceptors prepared by the method using the processing solution according to this example and the method using the conventional vacuum evaporation are almost the same, and both had no induction effect. . In other words, the photoreceptor produced by the method using the treatment liquid exhibited very excellent characteristics, comparable to those produced by the vapor deposition method.

In addition, the photoreceptor of this example had a very thin charge generation layer as described above, so that it had high mechanical strength.

(Effect of the invention) As described above, according to the manufacturing method of the present invention,
A charge generation layer is formed by adsorbing an organic charge generation material on an aluminum substrate that has an anodized film formed on its surface through anodization treatment, using the properties of the active surface without sealing. Therefore, an electrophotographic photoreceptor with high mechanical strength and good properties can be easily produced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a functionally separated photoreceptor, and FIG. 2 is a schematic process diagram showing an embodiment of the method for manufacturing an electrophotographic photoreceptor of the present invention.

Claims (1)

[Claims] 1. In a functionally separated electrophotographic photoreceptor in which a charge generation layer is formed on a conductive substrate and a charge transport layer is formed thereon, an aluminum substrate is used as the conductive substrate, and the aluminum substrate is anodized. an anodic oxide film is formed on the surface of the substrate, and the surface of the substrate is immersed in a dye or pigment solution without sealing the anodic oxide film, and the dye or pigment is adsorbed onto the substrate surface to generate a charge. A method for producing an electrophotographic photoreceptor, characterized in that a layer is formed.