JP3088221B2 - Manufacturing method of laminated photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated photoreceptor having at least a charge generation layer and a charge transport layer on a substrate.

[0002]

2. Description of the Related Art Photoreceptors used in electrophotography and the like are:
A photosensitive layer serving as a charge generation layer and a charge transport layer is provided on a substrate. Conventionally, inorganic photoconductive materials such as selenium, zinc oxide, titanium oxide, and cadmium sulfide have been used as photosensitive materials for forming such a photosensitive layer, but these inorganic photoconductive materials are highly toxic. And there were also problems with moisture resistance and the like.

For this reason, photoreceptors using an organic photoconductive material as a photosensitive material have come to be used. Such photoreceptors are excellent in film forming property, light weight, cost and the like. For use in a reversal development system such as a laser printer, further improvement in charge retention characteristics, sensitivity, repetition stability, durability, moisture resistance, image quality, and the like is desired.

For example, when a dispersion film using a so-called pigment-dispersed paint in which a pigment (charge generation material) is dispersed in a resin is formed as a charge generation layer on a substrate such as aluminum, the charge is transferred from the substrate to the charge transport layer. Various problems occur in image quality due to injection and the like. This is because the substrate has a structural defect, and various measures as described below have been taken to improve such a defect.

JP-A-58-30757 and JP-A-58-30757
Japanese Patent No. 95744 proposes a photoreceptor using an undercoat layer. JP-A-58-14841, JP-A-59-41360, and JP-A-61-140947 propose a photoreceptor obtained by subjecting an aluminum support to an alumite treatment.

In Japanese Patent Application Laid-Open No. 63-116160, a barrier layer having a thickness of 10
0 to 1000 °, and the thickness of the porous layer is 1 to 15 μm.
There has been proposed a laminated photoreceptor having a two-layered alumite layer formed thereon. In Japanese Patent Application Laid-Open No. 63-116161, a thickness of 1 to 15 μm is formed on an aluminum substrate.
m, and a laminated photoreceptor in which an alumite layer having a molar ratio of crystalline aluminum oxide to amorphous aluminum oxide of 50 to 1500 has been proposed. Japanese Patent Application Laid-Open No. 63-116164 discloses that an aluminum substrate has a thickness of 1 to 15 μm, and contains less than 10% by weight of magnesium, less than 200 ppm of iron, less than 1% by weight of copper and less than 1% by weight of silicon as impurities. % Has been proposed. JP-A-63-116165 proposes a laminated photoreceptor using a substrate in which an alumite layer is provided on an aluminum substrate and an undercoat layer is formed on the alumite layer.

[0007]

However, Japanese Patent Application Laid-Open Nos. 58-30757 and 58-95744 describe above.
JP-A-58-14841, JP-A-59-4136
No. 0, JP-A-61-140947, has the drawback that images are fogged due to changes in the environment, changes in the resistance value, and the like.

Further, JP-A-63-116160, JP-A-63-116161, and JP-A-63-116164
In the photoreceptor described in JP-A-63-116165, it is difficult to use pure aluminum as a substrate from the viewpoint of processability, strength, processing accuracy, price, etc. A so-called aluminum alloy is used, and there is a disadvantage due to this. In other words, the crystallized substance (alloy with the additive metal) exposed on the substrate surface becomes a defect point in the alumite treatment, and a large number of holes are formed on the alumite layer surface, and a charge generation layer is formed on the alumite layer. Even in this case, charge injection occurs from the substrate with the defective portion serving as a contact point. As a result, fog (or black point noise) occurs, and the image quality deteriorates.
Japanese Patent Application Laid-Open No. 63-116161 proposes a combination with an undercoat layer, but it is presumed that it is difficult to eliminate such a defect in combination with the prior application.

The present invention addresses these drawbacks.
It is an object of the present invention to manufacture an electrophotographic photosensitive member having high image quality without fogging.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a method of manufacturing a laminated photoreceptor having at least a charge generation layer and a charge transport layer on an aluminum substrate. An oxide film is formed by an oxidation method, and thereafter, impurities on a surface layer of the aluminum substrate are removed by etching, and an oxide film is further formed on the surface of the aluminum substrate by an anodic oxidation method.

Further, the present invention is characterized in that the aluminum substrate is formed in a cylindrical shape. Further, the present invention is characterized in that an oxide film having a thickness of 260 to 2600 ° is formed on the surface of the aluminum substrate.

[0012]

Generally, an oxide film formed on the surface of an aluminum substrate is composed of a portion made of crystalline or amorphous aluminum oxide called a barrier layer and a portion made of amorphous aluminum oxide called a porous layer. It is said that the barrier layer has an effect of preventing hole injection,
It is said that the porous layer has an effect of maintaining adhesiveness with the photosensitive layer formed thereon.

According to the present invention, however, an oxide film called a barrier layer is formed on the surface of an aluminum substrate by anodization, and impurities such as crystallized substances on the surface layer of the obtained aluminum substrate are removed by etching. Thereafter, an oxide film as a barrier layer is further formed on the surface of the aluminum substrate close to the pure aluminum by an anodic oxidation method. As a result, the barrier layer is in a state in which impurities such as crystallized substances do not exist, and a very high barrier effect is exhibited to prevent charge injection. (Or black point noise) is favorably suppressed.

On the other hand, since there is no aluminum oxide layer called a porous layer, the adhesiveness may be inferior.
When the aluminum substrate is formed into a cylindrical shape, precision drawing is usually performed, and the surface of the obtained aluminum substrate has a myriad of irregularities in the range of about 0.7 μm to 5 μm. Performs the function of maintaining adhesiveness. Therefore, although there is little need to use a porous layer for the aluminum substrate of the present invention, particularly good results can be obtained if present.

Specifically, the aluminum substrate is formed by forming an oxide film on the surface of the substrate by performing an electrolytic treatment using an aluminum support substrate processed into a suitable cylindrical shape as an anode and an organic acid or an inorganic acid as an electrolytic solution. The first step to
A second step of immersing this substrate in an acid solution to dissolve the crystallized compounds scattered on the substrate surface, and further subjecting the substrate to electrolytic treatment to dissolve the crystallized material, thereby forming a hole in the substrate surface. The oxide film is provided on the substrate surface by appropriately repeating the processing including the third step of forming the oxide film as necessary.

The charge generation layer is composed of an organic pigment selected from various azo pigments, perylene pigments, phthalocyanine pigments, polycyclic quinone pigments, indigo pigments, quinacridone pigments, etc. according to necessary characteristics, and various resins. It is obtained by preparing a coating material in which the pigment is uniformly dispersed by stirring and mixing with a solvent, and applying the coating material.

The charge transporting layer is made of an electron-donating substance comprising a derivative such as pyrazoline, triphenylmethane, oxadiazole, carbazole, hydrazone, styryl, imidazole, trinitrofluorenone, tetranitroxanthone, tetracyanoethylene, tetracyanoethylene, or tetracyanoethylene. Substances selected from materials with charge transporting properties such as cyanoquinodimethane, etc.
It is obtained by preparing a coating material in which a charge transporting substance is uniformly dissolved / dispersed by stirring and mixing with a solvent, and applying the coating material.

In the method for producing a photoreceptor of the present invention, a charge transport layer may be laminated on the charge generation layer, or a charge generation layer may be laminated on the charge transport layer. If necessary, an undercoat layer, a surface protective layer and the like may be provided.

Hereinafter, the present invention will be described with reference to examples.

[0020]

【Example】

(Example 1) A cylindrical substrate produced by precision drawing was washed with a detergent, pure water, etc., and as a first step, the cylindrical substrate was put in an electrolytic bath of a liquid temperature of 25 ° C. and 3% ammonium adipic acid. A chemical conversion treatment was performed at 0.5 mA / cm ² to 100 V. Thereafter, as a second step, the substrate was placed in a 10% nitric acid solution to dissolve crystallized substances on the substrate surface. Next, as a third step, the substrate is removed from the first substrate.
0.5 mA / cm ² in the electrolytic bath used in step
A chemical conversion treatment was performed up to 00 V, followed by washing and drying to form an aluminum oxide film on the cylindrical substrate. When the thickness of this aluminum oxide film was measured using an electron microscope, it was about 1300 °.

On this cylindrical substrate, a pigment-dispersed charge-generating coating obtained by mixing metal-free phthalocyanine, polyvinyl butyral resin and S-butyl alcohol at a weight ratio (8: 4: 228) was applied in an amount of about 0.1 to It was applied to a thickness of 0.2 μm and air-dried at room temperature for several minutes. On the formed charge generation layer, 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene, a polycarbonate resin and methylene chloride in a weight ratio (6:
10:68), the charge transport coating was applied so that the film thickness after drying was 25 μm, and dried to form a charge transport layer. Thus, an electrophotographic photoreceptor having the charge generation layer and the charge transport layer formed on the cylindrical substrate was obtained. (Example 2) In the same manner as in Example 1, a cylindrical substrate having a thickness of aluminum oxide of 2600 ° was produced. Further, a photosensitive layer similar to that of Example 1 was formed thereon to obtain an electrophotographic photosensitive member. (Example 3) A cylindrical substrate having a thickness of 650 ° of aluminum oxide was produced in the same manner as in Example 1. Furthermore,
A photosensitive layer similar to that of Example 1 was formed thereon to obtain an electrophotographic photosensitive member. (Example 4) In the same manner as in Example 1, a cylindrical substrate having a thickness of aluminum oxide of 260 ° was produced. Furthermore,
A photosensitive layer similar to that of Example 1 was formed thereon to obtain an electrophotographic photosensitive member. (Comparative Example 1) By performing the processing up to the first step in Example 1, a cylindrical substrate having a thickness of about 1300 ° of aluminum oxide was produced. Further, a photosensitive layer similar to that of Example 1 was formed thereon to obtain an electrophotographic photosensitive member. (Comparative Example 2) On the same cylindrical aluminum substrate used in Example 1, a barrier layer of about 60-70 °, 6-7
After forming a porous aluminum oxide layer having a thickness of μm and performing sealing treatment, a photosensitive layer including a charge generation layer of 0.1 to 0.2 μm and a charge transport layer of 25 μm was formed to obtain an electrophotographic photosensitive member.

The electrophotographic photoreceptor thus obtained was used as a laser beam printer (KX Matsushita Electric Co., Ltd. KX).
-P4620) and subjected to reversal development with corona charging and an initial surface potential set to -700V. The fog (or black spot noise) of the image of the blank portion at this time was measured by a photovoltameter. As a standard, the white paper portion of the paper not passed through the printer was measured with the same photovoltmeter as above, and the fog evaluation result and the image quality judgment result of the photoreceptor of the present invention when the value at that time was set to 100, are shown in the following table. It is shown in FIG.

[0023]

[Table 1]

From Table 1, it can be seen that the images obtained with the laminated photoreceptors of Examples 1, 2, 3 and 4 of the present invention are more fogged than those obtained with the conventional photoreceptors of Comparative Examples 1 and 2. The evaluation results are improved, and it can be seen that the images have excellent image quality.

[0025]

As described above, according to the present invention, the step of removing impurities of the substrate surface layer by etching is incorporated into the step of forming an oxide film on the surface of the aluminum substrate by the anodic oxidation method. It is possible to provide an oxide film in a state in which impurities such as a product do not exist.
Since the charge injection can be more effectively prevented by this oxide film than in the past, the photoreceptor using such an aluminum substrate has a problem of fog (or black spot noise) which is a problem in a laser printer or the like performing reversal development or the like. It is suppressed well and has high image quality characteristics.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Ryuichi Shingae 1006 Kazuma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-4-81861 (JP, A) JP-A Sho 63-116164 (JP, A) JP-A-60-174863 (JP, A) JP-A-5-94032 (JP, A) JP-A-4-174860 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/14 101

Claims (3)

(57) [Claims] In a method of manufacturing a laminated photoreceptor having at least a charge generation layer and a charge transport layer on an aluminum substrate, an oxide film is formed on the surface of the aluminum substrate by anodization, and thereafter, the surface of the aluminum substrate is formed. A method of manufacturing a laminated photoreceptor, comprising removing impurities of a layer by etching, and further forming an oxide film on the surface of the aluminum substrate by an anodic oxidation method. 2. The method according to claim 1, wherein the aluminum substrate is formed in a cylindrical shape. 3. A thickness of 260 mm on the surface of the aluminum substrate.
2. The method according to claim 1, wherein an oxide film of about 2600 [deg.] Is formed.