JPH0394266A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain stable and high image quality even in high-humidity environment by constituting a blocking layer of a anodized porous aluminum film subjected to a sealing treatment by a sealing agent essentially consisting of nickel fluoride. CONSTITUTION:An aluminum base body 1 is anodized in a cleaned state and is thereby formed with the anodized porous aluminum film 3 having fine pores 2. The base body is then immersed into an aq. soln. contg. the nickel fluoride adjusted with, for example, 2 to 10g/l as its essential component, by which the nickel fluoride is packed into the fine pores 2 and sealed parts 4 are formed. The sealing agent essentially consisting of the nickel fluoride can make the sealing treatment at the temp. lower than for the conventional sealing agents and, therefore, the unequalness of the surface generated at the time of drying after the sealing treatment of the anodized porous aluminum film 3 is drastically decreased and the generation of micro-defects is extremely lessened. The images having the high image quality stable in wide environmental conditions is obtd. in this way.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrophotographic photosensitive member used in an image forming system using an electrophotographic method, particularly an electrophotographic photosensitive member used in an image forming system using a reversal development method. Regarding the body.

[Conventional technology]

There are various types of photoreceptors used in electrophotographic imaging systems, but they can be broadly classified into selenium (Se), cadmium sulfide (CdS), and zinc oxide (
An inorganic photoreceptor using materials such as ZnO), polyvinylcarbazole (PVK),
) and other organic photoreceptors.

On the other hand, in the image format system, a printer system that processes digital signals and prints data has been developed and put into practical use. This print printer system transfers digital signal data to a laser beam scanner, LDE array, and so on.
A photoreceptor is irradiated with a light signal using a writing means such as a liquid crystal shutter, and is developed with toner to obtain an image.

Photoreceptors used in such image-forming systems include the above-mentioned Se, ZnO, and CdS, as well as PVK and TNF.
Photoconductors such as CT bodies have been used, but recently there has been a demand for photoconductors that have a high degree of freedom in selecting the sensitive wavelength range, and in particular, can set sensitivity to the output wavelength range of semiconductor lasers. Among these, organic photoreceptors, which are constructed by laminating a charge generation layer and a charge transfer layer, have high sensitivity. It is attracting attention as a product that satisfies the requirements of high durability and non-pollution in a well-balanced manner.

Incidentally, a reversal development method is often adopted as an image forming method for printers. On the other hand, if there is a minute defect on the photoreceptor that lowers the charging potential, it will appear as significant image noise such as fogging due to black spots, but this defect tends to be particularly emphasized when the above-mentioned reversal development method is adopted. be.

The reason for this defect is thought to be that charge is injected between the conductive support and the photoconductive layer in minute portions, resulting in a decrease in the charging potential. As a method to improve this problem, it has been conventionally considered to provide a blocking layer between the conductive support and the photoconductive layer, and this blocking layer can be made of cellulose, gelatin, polyamide, etc. A resin film such as Boria 4D is used.

[Problem to be solved by the invention]

However, when an electrophotographic photoreceptor equipped with a conventional blocking layer is used in a reversal development type image formation system, the problem of fogging caused by minute black spots cannot be completely solved. Particularly when the electrophotographic photoreceptor is used in a high humidity environment, the occurrence of minute black spots is accentuated and the image quality is degraded, so further improvements are required.

It is also possible to use an aluminum base as a conductive support and seal the porous anodic oxide film with a sealant containing nickel acetate as a main component as a blocking layer. This requires a considerably high temperature, and there is a problem that surface unevenness occurs during the sealing treatment process, resulting in the generation of micro defects, and if the sealing treatment temperature is lowered, the sealing performance deteriorates.

The present invention addresses image noise in conventional electrophotographic photoreceptors,
In particular, this invention was made to solve the problem of the occurrence of minute sunspots, and the object is to provide an electrophotographic photoreceptor that can provide stable high image quality even in a high humidity environment.

[Means and effects for solving the problems] In order to solve the above-mentioned problems, the present invention provides an electrophotographic photoreceptor in which a blocking layer and a photoconductive layer are laminated on an aluminum base, in which the blocking layer is a fluorescent layer. It consists of a porous aluminum anodic oxide film sealed with a sealing agent containing nickel oxide as a main ingredient.

In the electrophotographic photoreceptor constructed in this way, the sealant containing nickel fluoride as a main component can be sealed at a lower temperature than the conventional sealant containing nickel acetate as the main component. The surface unevenness that occurs when drying a porous aluminum anodic oxide film after sealing treatment is significantly reduced, and the occurrence of micro defects can be extremely reduced. This makes it possible to produce stable, high-quality images under a wide range of environmental conditions.

〔Example〕

First, a general outline of the electrophotographic photoreceptor according to the present invention will be explained in the first section.
The explanation will be based on the conceptual diagram in the figure and the schematic diagram of the blocking layer in FIG. In the figure, i is an aluminum base,
The aluminum substrate 1 is anodized after being cleaned by various degreasing and cleaning methods, and a porous aluminum anodic oxide film 3 having micropores 2 is formed. The anodizing treatment is performed by a conventionally known method, for example, in an acidic bath of sulfuric acid, oxalic acid, phosphoric acid, chromic acid, or the like. The preferred conditions for anodizing are a bath temperature of 20 DEG to 25 DEG C., a DC applied voltage of 5 to 20 .ANG., and a current density of 0.5 to 2 A/d.

Then 2~10g//! By immersing it in an aqueous solution containing nickel fluoride as a main component prepared by A blocking layer 5 consisting of a membrane is obtained.

The thickness of the anodic oxide film 3 as the blocking layer 5 is:
The thickness is preferably 0.5 to 15 μm.

The photoconductive layer formed on the blocking layer 5 configured as described above may be inorganic or organic, but preferably has a structure in which the charge generation layer 6 and the charge transfer layer 7 are laminated. The charge generation layer 6 is made of Se, Se/Te,
As. It is formed of an inorganic photoconductor such as Ses+ CdS+ ZnO, or an organic pigment such as phthalocyanine or azo dye, either alone or dispersed as fine powder in a binder resin. The thickness of this charge generation layer 6 is 0.1
It is preferable to set it to 1.5 micrometers. On the other hand, charge transfer layer 7
Examples include Se, Se/Te, AstSes+ polyvinylcarbazole, hydrazone derivatives, virazoline derivatives. Stilbene derivatives and the like can be used.

And when using substances that do not have medicinal properties by themselves,
Binder resin is blended. Note that the IHI thickness of this charge transfer layer 7 is 10 to 3 Qt! It is preferable to set it to m.

Next, specific examples of the electrophotographic photoreceptor according to the present invention will be described.

(First Example) A cylinder made of aluminum material according to JIS standard A-6063 was prepared, and the cylinder was washed in a 20 g/l aqueous solution of Alclean #100 (manufactured by Okuno Pharmaceutical Co., Ltd.) and washed with water. After that, 5g/I! ．． HNOI of
Neutralize with an aqueous solution and wash with water. Next, anodic oxidation was performed in a 185 g/i sulfuric acid electrolytic bath at a current density of 1.5 A/d- to form a 3 μm thick anodic oxide film. Next, after successive washing with water, nickel fluoride [Hardwall #5 (manufactured by NICCA CHEMICAL CO., LTD.)] was adjusted to pH 5.5 with acetic acid.
]5g/I! ．． It is immersed in an aqueous solution (temperature: 33°C) for 5 minutes to seal the holes. After washing thoroughly with water, heat at 60"C.
The bronching layer is dried for 15 minutes at room temperature and aged for 24 hours at room temperature.

Next, 10 parts by weight of metal-free lid cyanine (manufactured by Dainippon Ink Chemical Co., Ltd.) and 5 parts by weight of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., BX-2) were added to 1.2. Add 800 parts by weight of cyclohexanone and use a paint shaker (
(manufactured by Toyo Seiki Co., Ltd.) for 6 hours. An aluminum cylinder with a profking layer formed by the previous treatment is immersed in this dispersant, and a charge generation layer is placed on the pronking layer so that the film thickness after drying is 0.5 μm. Admonish the formal precepts.

Next, a vidrazone derivative (manufactured by Anan Fragrance Industry Co., Ltd.,
1.2.
The cylinder in which the charge generation layer was formed or treated was immersed in a solution dissolved in 120 parts by weight of dichloroethane.
A charge transfer layer is provided so that the film thickness after being pulled up and dried is 15 μm. As a result, an electrophotographic photoreceptor according to the present invention is obtained.

(Second Example) The anodized film was sealed with a 5g/e aqueous solution (liquid temperature 30''C) of a sealant AL-7 (manufactured by Okuno Pharmaceutical Co., Ltd.) containing nickel fluoride as its main component. Except that it is done by soaking for a minute.
An electrophotographic photoreceptor according to the second embodiment of the present invention was manufactured using the same processing steps as in the first embodiment.

Next, in order to compare with the electrophotographic photoreceptor according to the present invention, an electrophotographic photoreceptor as a comparative example as shown below was prepared.

(Comparative Example 1) 5.5 g of a sealant DX-500 (manufactured by Okuno Pharmaceutical Co., Ltd.) containing nickel acetate as a main ingredient was used to seal the anodic oxide film.
The electrophotographic photoreceptor of Comparative Example 1 was subjected to the same treatment steps as in Example 1 of the present invention, except that it was immersed in a /f aqueous solution (liquid temperature: 85° C.) for 10 minutes. (Comparative Example 2) The electrophotographic photoreceptor of Comparative Example 2 was prepared in the same process as in the first embodiment of the present invention, except that the anodic oxide film was sealed by immersion in boiling water for 25 minutes. Created.

(Comparative Example 3) An electrophotographic photoreceptor of Comparative Example 3 was prepared using the same processing steps as in the first example of the present invention, except that the anodic oxide film was not sealed.

(Comparative Example 4) The same method as in Example 1 of the present invention was applied directly to the aluminum cylinder surface without providing a profking layer made of a sealed porous aluminum anodic oxide film, that is, without providing an anodic oxide film. An electrophotographic photoreceptor of Comparative Example 4 was produced by forming a charge generation layer and a charge transfer layer in the processing step. The electrophotographic photoreceptors of the Examples and Comparative Examples produced as described above were installed in a laser beam printer using a reversal development method, and images were formed under various environments to evaluate the image quality. The results are shown in Table i. Table 1 As can be seen from Table 1 above, when the electrophotographic photoreceptor of each Example according to the present invention was used, high-quality images without image noise were obtained. Especially when using a photoreceptor? Under rJ humidity, fogging due to minute sunspots occurs and the image quality deteriorates significantly, making it difficult to put it into practical use.
It was confirmed that this was not possible.

(Effects of the Invention) As described above based on the embodiments, according to the present invention, since the sealant containing nickel fluoride as a main component can be sealed at low temperatures, the sealed aluminum anode The occurrence of surface unevenness of the oxide film is significantly reduced, and the occurrence of minute defects is extremely reduced.As a result, an electrophotographic photoreceptor that can form stable high-quality images under a wide range of environmental conditions can be obtained.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram showing an outline of an electrophotographic photoreceptor according to the present invention, and FIG. 2 is a schematic diagram showing an enlarged blocking layer thereof. In the figure, 1 is an aluminum substrate, 2 is a micropore, 3 is a porous aluminum anodic oxide film, 4 is a sealing part, 5 is a blocking layer, 6 is a charge generation layer, and 7 is a charge transfer layer.

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor formed by laminating a blocking layer and a photoconductive layer on an aluminum substrate, the blocking layer is a porous aluminum anodic oxide film sealed with a sealant containing nickel fluoride as a main component. An electrophotographic photoreceptor characterized by comprising: