JPH10288850A - Electrophotographic photoreceptor substrate and electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate of the electrophotographic photoreceptor reduced in amounts of ions and oxides remaining on the surface of the substrate subjected to anodic oxidation treatment despite of kind of washing agent for the anodic oxidation and capable of preventing occurrence of printing failure and to provide the electrophotographic photoreceptor using this substrate. SOLUTION: This aluminum substrate of the electrophotographic photoreceptor having the anodic oxidation treated film is controlled to a concentration of sulfuric acid in electrolysis processing of this anodic oxidation treatment to 80-150 g/l and the temperature of the sulfuric acid is regulated to 13-24 deg.C, and the electrophotograhic photoreceptor is formed by using this surface-treated substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum electrophotographic photoreceptor substrate having an aluminum anodic oxide film on its surface, and an electrophotographic photoreceptor using the same.

[0002]

2. Description of the Related Art The technology of electrophotography has been developed in the field of copiers, and has recently been applied to laser printers, etc., and boasts high image quality, high speed, and quietness comparable to conventional impact printers. , Used in most of the current recording devices. The photoreceptor used in these apparatuses is formed by providing a photoconductive layer on the surface of a conductive substrate. As a material of the photoconductive layer, an organic material has recently been mainly used, and the layer structure is such that an undercoat layer (UCL), a charge generation layer (CGL), and a charge transfer layer (CT) are formed on the surface of the substrate.
L) is generally a function-separated structure (FIG. 1) in which layers are sequentially stacked. As the material of the first undercoat layer applied to the surface of the substrate, there are two types: a type using a resin-based material such as a polyamide or a melamine type; and a type using an anodic oxide film formed on the surface of an aluminum substrate. The latter is generally advantageous in reliability under a high-temperature and high-humidity environment.

[0003] Anodizing treatment for forming an anodized film on the surface of an aluminum substrate can be performed, for example, according to a known process as shown in Table 1 below.

[0004]

[Table 1]

[0005] Among the anodizing treatments shown in Table 1, sulfuric acid, oxalic acid and the like are used in the electrolytic treatment step, and among them, simple sulfuric acid is generally used. In the case of forming an anodic oxide film with sulfuric acid, the concentration of sulfuric acid is 150 to 250 g / l in JP-A-8-50363 and 160 to 200 g in JP-A-8-171224.
It has been reported that / l is each in a desirable range.

[0006]

When the photosensitive layer is applied after the sealing treatment shown in Table 1, ions and oxides in the sealing agent remaining on the surface of the anodic oxide film, such as acetic acid for the sealing treatment. When nickel is used, if nickel oxide or the like or a large amount of ions or the like during the electrolytic treatment remains locally, the conductivity increases only in that portion, and printing failures, such as fogging and black spots in the reversal phenomenon method, occur. Occurs. Therefore, an operation of cleaning the anodic oxide film is performed as shown in Table 1. It has been found that an alkaline detergent having a pH of 9 to 10 is effective as the detergent used in this operation. However, depending on the surface condition of the anodic oxide film, it may be weak to alkalinity, or if the cleaning property is poor, the surface is partially corroded by washing, and the film thickness unevenness occurs when the photosensitive layer is applied This is also reflected in the print quality, causing uneven density, which is a problem.

Accordingly, an object of the present invention is to provide an electrophotographic photoreceptor substrate in which ions and oxides remaining on the surface of the anodic oxide film can be suppressed to a small extent irrespective of the type of cleaning agent for the anodic oxide film, thereby preventing printing trouble. And an electrophotographic photoreceptor using the same.

[0008]

Means for Solving the Problems The present inventor has analyzed an image defect portion based on the knowledge that it is necessary to reduce ions and oxides on the surface of the anodic oxide film in order to prevent printing trouble. As a result, the concentration of sulfate ions in the portion where black spots were generated was higher than that in the normal portion, and it was clarified that the sulfuric acid concentration during the electrolytic treatment affected image quality. The inventor of the present invention has conducted intensive studies on the anodic oxidation treatment conditions such as the concentration of sulfuric acid.
No. 63 and JP-A-8-171224 have found that the above-mentioned problems can be solved for the first time in a range and a predetermined temperature condition clearly different from the sulfuric acid concentration which is desirable in JP-A-8-171224, and have completed the present invention.

That is, the electrophotographic photosensitive member substrate of the present invention comprises:
In an electrophotographic photoconductor substrate made of aluminum having an aluminum anodic oxide film on its surface, the sulfuric acid concentration during the electrolytic treatment in the anodic oxidation treatment is 80 g / l to 150 g / l.
1 and the sulfuric acid temperature is 13 ° C. or higher and 24
The aluminum anodic oxide film is formed by controlling the temperature to not more than ℃.

The present invention also relates to an electrophotographic photoreceptor using the electrophotographic photoreceptor substrate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The photoreceptor substrate for electrophotography of the present invention will be specifically described below. The electrophotographic photoreceptor substrate of the present invention can be obtained by appropriately controlling the sulfuric acid concentration and the sulfuric acid temperature during the electrolytic treatment in the anodic oxidation treatment in Table 1 shown as an example, and other steps include, for example, This can be done by following Table 1.

Preferably, as shown in Table 1, the aluminum substrate is degreased and washed before being subjected to anodizing treatment. In order to enhance the degreasing effect, etching is usually performed with an alkaline solution such as sodium hydroxide, but etching with an acid that does not generate large etching pits is preferable.

In the present invention, the electrolytic treatment in the anodic oxidation treatment is performed in sulfuric acid, and the sulfuric acid concentration is 80 g / l or more and less than 150 g / l, particularly preferably 130 g / l or more.
It is 45 g / l or less. When the sulfuric acid concentration is less than 80 g / l, the film growth is inferior. On the other hand, when the sulfuric acid concentration is 150 g / l or more,
When used in an electrophotographic photoreceptor, printing troubles such as black spots and fogging occur, which adversely affects image quality.

The temperature during the electrolysis is 13 to 24.
° C, preferably 18 to 23 ° C, particularly preferably 20 to 2 ° C.
1 ° C. If the temperature is lower than 13 ° C., the film grows poorly. On the other hand, if the temperature is higher than 24 ° C., printing troubles such as black spots and fogging occur when used in an electrophotographic photoreceptor, which adversely affects image quality.

Further, the amount of aluminum dissolved in sulfuric acid is 1
0 g / l or less, more preferably 3 to 7 g / l
It is. Nickel acetate is generally used as a sealing agent after anodization, but treatment with pure water may be used. The temperature of the pore-sealing treatment with pure water is preferably from 60 to 80 ° C, but is most preferably about 70 ° C. The processing time is 5 to 10 minutes, preferably 8 to 10 minutes.

Next, the specific structure of the electrophotographic photosensitive member of the present invention using the electrophotographic photosensitive substrate will be described with reference to the drawings. The photoreceptor includes a so-called negatively-charged laminated photoreceptor, a positively-charged laminated-type photoreceptor, and a positively charged single-layered photoreceptor. An example will be specifically described.

In the negative-layer laminated type photoreceptor shown in FIG. 1, a photosensitive layer 5 is further laminated on an undercoat layer 2 laminated on a conductive substrate 1. The photosensitive layer 5 is of a function separation type in which the charge transport layer 4 is laminated on the charge generation layer 3 and is separated into a charge generation layer and a charge transport layer.

The conductive substrate 1 functions not only as an electrode of the photosensitive member but also as a support for the other layers.
This is an aluminum substrate that may be in any of a cylindrical shape, a plate shape, and a film shape. This aluminum substrate has an undercoat layer 2 on the surface.
As the aluminum anodic oxide film.

[0019]

The charge generation layer 3 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. Generates electric charge. It is important for the charge generation layer 3 to have high charge generation efficiency and at the same time to inject the generated charges into the charge transport layer 3, and it is desirable that the charge generation layer 3 has a low electric field dependence and is well injected even at a low electric field. Metal-free phthalocyanine, phthalocyanine compounds such as titanyl phthalocyanine, various azos, quinones, indigo, cyanine, squarylium, azurenium, pyrylium compounds or other pigments or dyes, or selenium or selenium compounds are used as the charge generating material in the charge generating layer. A suitable substance can be selected according to the light wavelength range of the exposure light source used for image formation.
These compounds are used in an amount of 50 to 5,000 parts by weight, preferably 100 to 100 parts by weight, per 100 parts by weight of the resin binder.
0 parts by weight.

Since the charge transport layer 4 is laminated on the charge generating layer 3, its thickness is determined by the light absorption coefficient of the charge generating substance, and is generally 5 μm or less, preferably 1 μm or less.
It is as follows. The charge generation layer 3 may be mainly composed of a charge generation substance and may be used by adding a charge transport substance or the like thereto. As the resin binder for the charge generation layer, polycarbonate, polyester, polyamide, polyurethane,
Polymers and copolymers of polyamitide, epoxy, polyvinyl butyral, phenoxy, silicone, and methacrylic acid esters, and their halides, cyanoethyl compounds, and the like can be appropriately used in combination.

The charge transport layer 4 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, and the charge is received when receiving light. It has a function of transporting charges injected from the generating layer. As the resin binder for the charge transport layer, polycarbonate, polyester, polystyrene, polymers and copolymers of methacrylic acid esters are used, but mechanical, chemical and electrical stability, adhesion, etc. Compatibility with the charge transport material is important. A distyryl compound, a diamine compound, a hydrazone compound, a stilbene compound, or the like is used as a charge transport material in such a charge transport layer. The amount of the compound used is 20 to 500 parts by weight, preferably 30 to 300 parts by weight, per 100 parts by weight of the resin binder.
Parts by weight.

The thickness of the charge transport layer is preferably in the range of 3 to 50 μm in order to maintain a practically effective surface potential.
More preferably, it is 15 to 40 μm.

[0024]

Next, the present invention will be specifically described based on examples. Example 1 An aluminum substrate (JIS6063 material) was degreased (Fine Cleaner 315: Nippon Parker Rising Co., Ltd.)
Degreased at a temperature of 50 ° C., followed by washing with water to remove the degreaser. Thereafter, degreasing was further performed with nitric acid. Next, the electrolytic treatment was performed in sulfuric acid (concentration: 70, 80,
(100, 120, 150, 170, 190 g / l) at a temperature of 20 ° C. for 24 minutes, and then washed with pure water. After performing the sealing treatment with pure water at a temperature of 70 ° C. for 8.5 minutes, the substrate is ultrasonically cleaned with pure water and dried with hot air to produce an aluminum substrate (hereinafter referred to as a base tube) on which an anodized film is formed (hereinafter referred to as a tube). 1000).

Next, the obtained tube was washed at a concentration of 2% by weight with an alkaline cleaning agent (Castrol 450: manufactured by Castrol Co., Ltd.), rinsed with pure water, and dried with hot pure water at 65 ° C. . Next, the charge generation layer (X-type metal-free phthalocyanine was added to vinyl chloride-vinyl acetate copolymer at 40% by weight)
And dispersed in a drying oven at 80 ° C. for 30 minutes. Next, a charge transport layer (a mixture of a polycarbonate and a hydrazone-based material) is applied,
It was dried in a drying oven at 90 ° C. for 2 hours to produce a photoreceptor.

Image evaluation of the produced photoreceptor gave the results shown in Table 2 below. No black spots or fogging were observed at a sulfuric acid concentration of 150 g / l or less. On the other hand, 80
Under conditions of less than g / l, the growth of the film was not good.

[0027]

[Table 2]

Example 2 An aluminum substrate (JIS 5000 type) was treated with a degreasing agent (U cleaner AD68: manufactured by Uemura Kogyo Co., Ltd.) at a concentration of 5%.
%, At a temperature of 40 ° C. for 5 minutes, followed by washing with water to remove the degreasing agent. Thereafter, degreasing was further performed with nitric acid. Next, the electrolytic treatment was performed in sulfuric acid (temperatures 10, 13, 1).
6, 19, 21, 24, 26 and 28 ° C.) at the sulfuric acid concentration of Example 1 at each temperature. However, 28 ° C
Under the condition (1), the dissolution reaction of aluminum was remarkable, and it was difficult to control the film thickness. The obtained raw tube was washed with a 0.5% by weight solution using an alkaline cleaning agent (Castrol 200: manufactured by Castrol Co., Ltd.), and then rinsed with pure water.
It was dried with warm pure water at 5 ° C.

Next, a charge generating layer (X-type metal-free phthalocyanine dispersed in a vinyl chloride-vinyl acetate copolymer at a ratio of 40% by weight) was applied thereto, and dried in an oven at 80 ° C. for 30 minutes.
Dried for minutes. Subsequently, a charge transport layer (a mixture of a polycarbonate and a butadiene-based material) was applied to a thickness of about 25 μm, and dried in a drying oven at 90 ° C. for 2 hours to produce a photoreceptor. In this example, the thickness of the anodic oxide film, the charge generation layer and the charge transport layer of the photoreceptor was 6 to 8 μm, respectively.
It was in the range of 0.2-0.5 μm and 20-24 μm.

When the image of the produced photoreceptor was evaluated, the results shown in Table 3 below were obtained. In the table, ：: print quality is good, Δ: print quality is normal, and x: print quality is poor.

[0031]

[Table 3]

[0032]

According to the present invention, when development is carried out using an electrophotographic photosensitive member using the electrophotographic photosensitive member substrate of the present invention, "black spots"
An excellent image without "density unevenness" can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a laminated structure of a negatively charged electrophotographic photosensitive member according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive substrate 2 undercoat layer 3 charge generation layer 4 charge transport layer 5 photosensitive layer

Claims (2)

[Claims] 1. An aluminum electrophotographic photoreceptor substrate having an aluminum anodic oxide film on a surface thereof.
The concentration of sulfuric acid during the electrolytic treatment in the anodic oxidation treatment was 80 g /
a photoreceptor substrate for electrophotography, wherein the aluminum anodic oxide film is formed by controlling the temperature in a range of 1 to less than 150 g / l and controlling the sulfuric acid temperature in a range of 13 to 24 ° C. 2. An electrophotographic photosensitive member using the electrophotographic photosensitive member substrate according to claim 1.