JPH01114855A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the bonding strength of a photosensitive layer to be formed on an anodized film on an Al base body to the anodized film by forming a specified film on said anodized film. CONSTITUTION:An anodized film 2, a film 3 comprising a specified mixture, and an undercoat layer 4 to be formed if necessary, and a photoconductive layer 5, are laminated in the order on a base body consisting of Al. The film 3 is constituted of a mixture of >=one kind of metal compd. (A), and a polymer (B) having OH groups, carboxyl groups, and acrylamide groups, and the amt. of the compd. (A) to be deposited is regulated to >=0.1mg/m<2>. It is preferred to use a Zr compd. (e.g. ammonium zirconium carbonate) or a Zr compd. in addn. to a Cr compd. for the compd. (A). Polyacrylamide, etc., is used for the polymer (B).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an electrophotographic photoreceptor used in electrostatic copying machines, computer printers, and the like.

In this specification, the term aluminum is used to include its alloys.

2. Description of the Related Art Electrophotographic photoreceptors used for the above-mentioned purposes are generally constructed by covering a conductive support made of aluminum with a photoconductive layer made of a photoconductive insulating material.

Conventionally, in order to improve the adhesion between the conductive support and the photoconductive layer, the conductive support is anodized as a base treatment, and an unsealed anode is deposited on the surface of the support as an interface layer. It is known that an oxide film is formed and a photoconductive layer is coated through the film (for example, Japanese Patent Laid-Open No. 61-19824).
No. 3).

Problems to be Solved by the Invention However, the unsealed anodic oxide film has a highly adsorbent surface.
In particular, if the photoconductive layer is formed immediately after the film is formed, good adhesion with the photoconductive layer can be achieved. If the period of time is long, there is a drawback that good adhesion cannot be obtained. That is, in actual production, after the conductive support is anodized, it is kept in stock for several days to a month or more without forming a photoconductive layer.
A photoconductive layer may then be deposited. In such cases, due to the excellent adsorption properties of the anodic oxide film, depending on the storage environment and storage period, natural sealing may occur due to reaction with dirt or moisture in the atmosphere, resulting in deterioration of the oxide film over time. ,
There was a problem in that the desired good adhesiveness could not be obtained and poor adhesion occurred.

Moreover, by interposing an anodic oxide film between the conductive support and the photoconductive layer, the photoreceptor can have excellent electrical properties at room temperature. Depending on the type (particularly sulfuric acid film), when used in a high temperature and high humidity environment, there is a problem in that the electrical characteristics deteriorate and good image characteristics cannot be obtained.

On the other hand, an undercoat layer is also provided between the photoconductive layer and the anodic oxide film for the purpose of further improving the adhesion between the conductive support and the photoconductive layer and improving the electrical properties. However, even in this case, if the period between forming the undercoat layer after the anodizing treatment is long, the adhesion between the undercoat layer and the anodized film will deteriorate, and the high temperature,
It was not possible to prevent the deterioration of electrical characteristics that occurs when used in a high humidity environment.

This invention has been made in view of this technical background, and has excellent adhesion with the photoconductive layer or undercoat layer, and also has good adhesion even when the photoconductive layer etc. is coated after a long period of time. The object of the present invention is to provide an electrophotographic photoreceptor that maintains its properties and does not cause deterioration in electrical performance even under high temperature and high humidity environments.

Means for Solving the Problems For the above purpose, the inventor has conducted various experiments and research, and has found that the surface of the anodic oxide film formed on the conductive support,
Furthermore, by forming a mixed film of a metal compound and a polymer having a hydroxyl group, a carboxyl group, or an acrylamide group, which has excellent adhesiveness and water repellency, the amount of the metal compound adhered to is within a predetermined range. The present invention was completed based on the finding that it is possible to prevent a decrease in the adhesion of a photoconductive layer or an undercoat layer and a deterioration of electrical characteristics due to changes in usage environmental conditions.

That is, as shown in FIG. 1, in this invention, a conductive support (1) made of aluminum is coated with an anodic oxide film (2), and one or two types of anodized film are coated on the surface of the anodic oxide film. The mixed film (3) of the above metal compound and a polymer having a hydroxyl group, a carboxyl group, or an acrylamide group has a coating amount of the metal compound (if two or more types of metal compounds are included, at least one of them). 0. The gist of the present invention is to provide an electrophotographic photoreceptor characterized in that it is coated with a concentration of 111 tW/lri or more, and a photoconductive layer (5) is formed on the mixed film.

The type of aluminum material used as the constituent material of the conductive support (1) is not particularly limited, and an appropriate one may be selected from various commercially available aluminum materials in consideration of workability, strength, hardness, etc. You can use it selectively. - For boat fishing, aluminum wrought materials such as pure aluminum and A3000 series are preferably used. Furthermore, the method for manufacturing the support is not limited.

The type of anodic oxidation film (2) formed on the surface of the conductive support (1) is not limited to a specific film, and various anodic oxidation treatments such as sulfuric acid method, oxalic acid method, chromic acid method, etc. A film formed using any treatment method among the above methods may be used. Further, the anodizing treatment conditions may be set according to a conventional method. Furthermore, the anodic oxide film (2) may be sealed or may be left unsealed.

The mixed film (3) formed on the surface of the anodic oxide film (2) is formed by applying a treatment solution in which a metal compound and a polymer having a hydroxyl group, a carboxyl group, or an acrylamide group are mixed in an aqueous solution or emulsion state. ,
It is formed through a drying process. Here, as the metal compound, a zirconium compound is mentioned as a preferable example. Furthermore, examples of zirconium compounds include ammonium zirconium carbonate, alkali salts of fluorozirconate, ammonium salts, zirconium hydrofluoric acid, etc. However, when a zirconium fluoride is used in particular, the film is formed due to the action of fluorine. (3) It is preferable in that the adhesiveness of itself to the conductive support (1) can be made higher.

Other metal compounds include Cr compounds.

Specific examples of Cr compounds include trivalent or hexavalent Cr
Examples include various salts and oxides containing Cr203 (for example, Cr203). The number of metal compounds contained in the film may be not only one, but two or more. A preferred example of a combination of two or more metal compounds is a combination of a zirconium compound and a chromium compound.

On the other hand, examples of polymers having hydroxyl or carboxyl groups include polyacrylic acid, polyvinyl alcohol, cellulose hydroxyethyl ether, ethylene maleic anhydride, polyvinylpyrrolidine, and polyvinylmethyl ether. Examples of the combination include acrylic copolymer latex. Among these, polyacrylic acid is preferred. Further, the polymer having an acrylamide group refers to so-called polyacrylamide.

The mixing ratio of the metal compound as described above and the polymer having a hydroxyl group, a carboxyl group, or an acrylamide group in the treatment liquid is determined based on the content ratio of the metal compound and the polymer in the film when there is only one type of metal compound. The mixing ratio is preferably 0.5 to 20 parts of the polymer to 1 part of the metal compound, preferably 1 to 10 parts. In addition, even when two types of metal compounds are contained, they are mixed at a ratio such that the content ratio in the film is 0.5 to 20, preferably 1 to 10, of the polymer to 1 of the total amount of metal compounds. It's good. Further, as a method for applying the treatment liquid, any method such as a spray method, a dipping method, a roll coating method, a dipping method, etc. can be adopted. Also, the drying time after application is 15 to 3
It is desirable to carry out the process at a temperature of about 00°C. Although the drying time varies depending on the drying temperature, for example, at 100 to 150°C, it is preferable to dry for about 30 seconds.

By the way, in the present invention, the mixed film (3) has a metal compound (if two or more types of metal compounds are included, at least one of them) with an adhesion amount of 0. IIIt
It is required to be formed in a state specified by g/rd or more. The reason for setting the metal adhesion amount in this way is as follows. That is, by coating the mixed film (3), it is possible to maintain good adhesion even after forming a photoconductive layer or an undercoat layer after a long period of time, and it is possible to maintain good electrical properties in high temperature and high humidity environments. One of the reasons why it does not cause deterioration is that the mixed film is a water-based film, but if the amount of metal compound deposited is 0. This is because, if it is less than IIIy/rd, good water repellency cannot be obtained, resulting in poor adhesion to the photoconductive layer. Even if the number of one-way feeds is increased, the effect will not be particularly increased, but rather the disadvantage of increased costs due to wasted material will result. The preferred range of coating amount is 0.5 to 500rr for any metal compound.
rg#. The amount of the metal compound deposited may be set by setting the mixing ratio of the metal compound and a polymer having a hydroxyl group, a carboxyl group, or an acrylamide group during the production stage of the treatment solution, or by setting the amount of the metal compound attached to the conductive support of the treatment solution. This may be done by adjusting the amount of coating. The final coating amount is 0°5~5000111g/
It is preferable to set it to 1-1100 OIrt/m in terms of being able to more effectively exhibit the effect of improving adhesiveness, etc., and it is particularly good to set it to m.

The photoconductive layer (5) may be directly coated on the surface of the mixed film (3), or may be coated via an undercoat layer (4) as shown in the drawings.

The type of photoconductive layer (5) is not particularly limited,
Any of selenium-based materials, amorphous silicon-based materials, organic materials, etc. may be used. Further, the undercoat layer is generally made of polyamide resin.

Effects of the Invention As described above, the present invention includes forming an anodic oxide film on a conductive support made of aluminum, and coating the surface of the anodic oxide film with one or more metal compounds and a hydroxyl group or a carboxyl group. The mixed film with a polymer having a group or an acrylamide group reduces the adhesion amount of the metal compound (at least one of the metal compounds when two or more types are included) to 0. It is characterized in that it is coated in a state defined by 1111/rd or more, and a photoconductive layer is formed on the mixed film. Therefore, as is clear from consideration of the Examples described later, not only when the photoconductive layer and undercoat layer are formed immediately after forming the mixed film, but also when the photoconductive layer and undercoat layer are formed after a long period of time, the conductive support and the Maintains sufficient adhesion with the conductive layer,
A stable photoreceptor can be obtained without causing phenomena such as separation, blistering, and cracking of the photoconductive layer. Furthermore, by forming a mixed film on the surface of the anodic oxide film, high temperatures and
The photoreceptor does not cause deterioration of electrical performance in a high humidity environment, exhibits excellent electrical performance regardless of the environmental conditions in which it is used, and has excellent image characteristics.

EXAMPLES Next, examples of the present invention will be shown in comparison with comparative examples.

A3003 aluminum alloy was extruded into an extrusion vibrator using a conventional method, then subjected to drawing processing, and then cut to a surface roughness of 0. An IS with a smooth finish was used as a conductive support.

A plurality of the above-mentioned supports were prepared, and each was subjected to a current density in a sulfuric acid electrolyte having a sulfuric acid concentration of 15% and a liquid temperature of 20±1°C; 1. Anodic oxidation treatment was carried out under conditions of 3 A/dTIl and a treatment time of 20 minutes to form a sulfuric acid anodic oxide film.

Then, for half of the conductive supports, the pressure was 4 Kgf.
/cIII pressurized steam treatment was performed for 25 minutes. The other half of the holes were not sealed. After that, the following processing was performed.

(Example 1) First, a solution (A) containing ammonium zirconium carbonate and polyacrylamide having the properties shown below was prepared.

Properties of solution (A) PH: 8.1 (at 25°C) Viscosity: 23 cP (at 27°C) Amount of ammonium zirconium carbonate: (0.3 in zirconium)
%) Amount of polyacrylamide: 5% Then, one part of the solution (A) and two parts of water were mixed to prepare a treatment liquid. Next, this treatment solution was applied to the surface of the anodic oxide film of the conductive support using a rubber roll, and then heated at 150°C.
Drying was performed for 20 seconds to form a mixed film of zirconium compound and polyacrylamide. The amount of film at this time was 100111ff#, and the amount of ammonium zirconium carbonate deposited was about 5η/TIt.

For the pore-sealed one and the unsealed one, one was coated with an undercoat layer to a thickness of about 1 μm immediately after forming the mixed film, and the other was coated with an undercoat layer to a thickness of about 1 μm after forming the mixed film.
After being left for 30 days in an environment of 70% humidity and 70% temperature, a similar undercoat layer was formed. The undercoat layer was formed by applying and drying a polyamide resin.

Thereafter, polyvinyl Rubazol/trinitrofluorenone (PVK/TNF) was coated as a photoconductive layer to obtain photoreceptors according to the present invention (Samples No. 1 to 4).
The PVK/TNF coating was formed by dipping, and the layer thickness was 15 μm in each case.

(Example 2) A solution (B) containing a fluorinated zirconium compound and polyacrylamide and a solution (C) containing a fluorinated chromium compound having the properties shown below were prepared.

Properties of solution (B) PH: 5.2 (at 25°C) Viscosity: 16 cP (at 27°C) Specific gravity: 1.025 (at 27°C) Molecular weight: 5-
Zirconium oxide ffi: (Zirconium 0.5
%) Amount of polyacrylamide: 5% Amount of chromium: 70.83% Concentration of F = 0.9% Then, mix 5 parts of solution (B), 1 part of solution (C), and 10 parts of water to prepare a treatment liquid. , After applying the treatment liquid to the surface of the anodic oxide film of the conductive support using a rubber roll,
Drying was performed at 0° C. for 20 seconds to form a mixed film of a zirconium compound, a chromium compound, and polyacrylamide. The coating amount at this time was 60 rIrg/m. The amount of the zirconium compound attached was 51 ng/d1, and the amount of the chromium compound attached was 2η/g.

As in Example 1, the sealed and unsealed ones were coated with an undercoat layer immediately after forming the mixed film under the same conditions as in Example 1, and the mixed film was formed at a temperature of 25°C. After being left for 30 days in an environment of 70% humidity and 70% temperature, a similar undercoat layer was formed.

Thereafter, PVK/TNF was coated as a photoconductive layer under the same conditions as above to obtain a photoreceptor according to the present invention (Sample No.
5-8).

(Example 3) A 165 gravure mesh roll coat was applied to the surface of the anodic oxide film using a treatment solution having a composition as shown in Table 1 at 10% (V/V) dilution, and then 150°C
It was dried for 30 seconds to form a mixed film of a chromium compound and a polymer having a carboxyl group. The amount of chromium compound deposited at this time was about 2 mg/rrr.

As in Table 1 and Example 1, for the sealed and unsealed ones, the undercoat layer was immediately coated under the same conditions as Example 1 after forming the mixed film, and the mixed film was formed. After leaving it for 30 days in an environment with a temperature of 25° C. and a humidity of 70%, a similar undercoat layer was formed.

Thereafter, PVK/TNF was coated as a photoconductive layer under the same conditions as above to obtain a photoreceptor according to the present invention (Sample No.
9-12).

[Comparative Example] For each of the pore-sealing treated without forming a mixed film and the unsealed pore, one was coated with an undercoat layer under the same conditions as the example immediately after forming the anodic oxide film, and the other was anodized. After forming the oxide film, it was allowed to stand for 30 days in an environment with a temperature of 25° C. and a humidity of 70%, and then an undercoat layer was formed on it to produce a product.

Thereafter, PVK/TNF was coated as a photoconductive layer under the same conditions as above to obtain a photoconductor for comparison (Sample N
o13-1B).

The following tests were conducted on each of the photoreceptors obtained as described above, either during the production or after completion.

[Water-based investigation of mixed films] For each mixed film, drop 2 μΩ of pure water on the surface,
The contact angle was measured after 10 minutes. For comparison products, the surface of the anodic oxide film was investigated.

[Adhesion Test] After forming the undercoat layer, a tape peeling test was conducted.

[Image performance] For each photoreceptor, the occurrence of black spots during the zero printing was investigated. The study was conducted under two different environmental conditions, varying temperature and humidity.

The above results are shown in Table 2 below.

[Blank below] As is clear from the above results, in the product of the present invention, the mixed film of a metal compound and a polymer having a hydroxyl group, a carboxyl group, or an acrylamide group has good water repellency;
In addition, even if it takes a long time to form the undercoat layer after forming the mixed film, the adhesion between the conductive support and the undercoat layer will be affected, as in the case where the coating is formed immediately. It can be seen that it has excellent adhesion with Furthermore, it can be seen that even if the environmental conditions in which the photoreceptor is used are bad, there is no deterioration in the electrical performance of the photoreceptor, and hence there is no deterioration in the image characteristics.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged sectional view showing an embodiment of a photoreceptor according to the present invention. (1) Conductive support, (2) Anodic oxide film, (3) Mixed film, (4) Undercoat layer, (5) Photoconductive layer. that's all

Claims (3)

[Claims] (1) An anodic oxide film is coated on a conductive support made of aluminum, and the surface of the anodic oxide film is coated with one or more metal compounds and a heavy metal compound having a hydroxyl group, a carboxyl group, or an acrylamide group. A mixed film with coalescence is formed to coat the metal compound (if two or more metal compounds are included, at least one of them) in a state in which the amount of adhesion is regulated to be 0.1 mg/m^2 or more, A photoreceptor for electrophotography, characterized in that a photoconductive layer is formed on the mixed film. (2) The electrophotographic photoreceptor according to claim 1, wherein the metal compound is a zirconium compound. (3) The electrophotographic photoreceptor according to claim 1, wherein the metal compound is a zirconium compound and a chromium compound.