JPH0588392A - Electrophotographic sensitive body and substrate used for it and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body suitable for an electrophotographic device with high resolution where coherent light with long wave length is made exposure light without applying roughening treatment to the surface of the photosensitive body by manufacturing a substrate having the limited shape, roughness and the material of its surface and using the substrate. CONSTITUTION:The surface of a substrate 11 consisting of aluminum or aluminum alloy is roughened by blowing abrasive containing water against it and washed and dried with warm water to manufacture an substrate for electrophotographic sensitive bodies, substrate where the surface is roughened at random in the >=3 to <=5mum Rmax range and the oxidation degree of the surface evaluated by ESCA is >=2.0. The substrate is used to obtain a suitable photosensitive body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a selenium-based electrophotographic photosensitive member provided with a photosensitive layer made of a selenium-based photoconductive material, a substrate used for the same, and a method for producing the same. TECHNICAL FIELD The present invention relates to a selenium-based electrophotographic photosensitive member used for an apparatus that uses coherent light having a long wavelength as an exposure light among electrophotographic apparatuses such as machines, printers, and facsimiles, a substrate used therefor, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Among electrophotographic devices such as electrophotographic copying machines, printers, facsimiles and the like, a device which uses coherent light having a long wavelength, such as light from a semiconductor laser diode or a light emitting diode, as exposure light. However, there is a problem that an interference fringe pattern appears in an image due to a thickness deviation of a photosensitive layer of an electrophotographic photosensitive member (hereinafter, also simply referred to as a photosensitive member) to be mounted, and particularly in a high resolution model (400 dpi or more). It becomes a big problem. As a method for solving this problem, there is known a method in which the surface of the substrate of the photoconductor is made a rough surface limited to a certain roughness, and the exposure light which is incident and reflected on the surface of the substrate is scattered, or a method in which the photoconductor surface is roughened. ing. Further, the types of toner are increasing due to the diversification of the uses of the apparatus, and depending on the type, toner cleaning becomes insufficient and toner filming easily occurs, and if the cleaning conditions are strict for the purpose of preventing this. There is a problem that the surface of the photoconductor is damaged and the life of the photoconductor is shortened. In order to solve these problems, it is effective to roughen the surface of the photoconductor.

[0003]

As described above, it is effective to roughen the surface of the photoconductor in order to prevent interference fringe patterns from appearing in the image and to facilitate toner cleaning. Is. However, in a photoconductor whose photosensitive layer is made of amorphous As ₂ Se ₃ , or at least a photoconductor whose photosensitive layer surface is made of amorphous As ₂ Se ₃ , the surface hardness is high and the heat resistance is good. However, it is difficult to perform roughening and subsequent cleaning in a photoconductor whose photosensitive layer is made of amorphous Se or an amorphous Se-Te alloy.
The problem arises that image unevenness occurs due to crystallization and cleaning unevenness in cleaning processing such as washing.

By the way, in a selenium-based photoreceptor having high sensitivity to long-wavelength light, a Se-Te alloy having a high Te concentration is used. The higher the Te concentration is, the better the sensitivity is, but the dark decay and fatigue are increased. On the other hand, in a high-resolution electrophotographic apparatus, an image is output at a low speed, so a photoreceptor having a high retention rate (low dark decay) and low fatigue is required. For this reason, a photoreceptor used in a high-resolution electrophotographic apparatus that uses long-wavelength light as exposure light is a carrier transport layer (amorphous Se layer) as disclosed in, for example, JP-A-55-77744. , Carrier generation layer (high Te concentration amorphous Se-Te alloy layer), overcoat layer (lower Te concentration amorphous Se-Te alloy layer than charge generation layer)
The photoconductor is provided with a photosensitive layer having functionally separated layers. Among them, the film thickness of the carrier generation layer and the Te concentration have a great influence on the sensitivity, dark decay, and fatigue. The film thickness exceeds 0.3 μm,
When the Te concentration exceeds 48%, dark decay and fatigue increase, which causes problems, so that the carrier generation layer can be optimized within the range below this. When the film thickness is less than 0.1 μm, the change with time becomes large, which is not preferable. Then, the overcoat layer, which is the surface layer, contains a considerably large amount of Te, which is smaller than that of the carrier generation layer, but it is difficult to perform roughening processing.

The present invention has been made in view of the above points, and produces a substrate having a limited surface shape, surface roughness, and surface material, and by using this substrate, the surface of the photoconductor is roughened. An object of the present invention is to obtain an Se-based photosensitive member suitable for a high-resolution electrophotographic apparatus that uses coherent light having a long wavelength as exposure light without performing a chemical processing.

[0006]

The above-mentioned problems are solved by the present invention.
According to
The maximum height R of the surface_maxIs 3 μm or more and 15 μm or less
The surface is randomly roughened within the range and the X-ray photoelectric
Degree of Oxidation Al Evaluated by Spectroscopic Spectroscopy (ESCA)
_oxide/ Al_metalFor substrates with a value of 2.0 or more
A photosensitive layer made of selenium-based photoconductive material on its surface.
By forming, the surface of the photosensitive layer has a maximum height R _maxBut
10-point average roughness within the range of 0.5 μm to 3.0 μm
R_zIs in the range of 0.35 μm or more and 2.0 μm or less
Solved by using a photoconductor that has a random rough surface
Be done.

The above-mentioned substrate can be manufactured by spraying water containing an abrasive on the surface of a substrate made of aluminum or an aluminum alloy to make it rough, washing it, and then drying with warm water. At this time, it is preferable to use alumina as the polishing agent.

[0008]

[Function] The surface of the substrate made of aluminum or aluminum alloy can be roughened by spraying water containing an abrasive to roughen the surface of the substrate at random, and subsequently, the surface of the substrate can be cleaned to clean the surface. By drying with warm water, a hydroxide film is formed on the surface and wettability is improved. When a photosensitive layer made of a Se-based material is formed on such a substrate, a photosensitive member having a photosensitive layer having good adhesion, a uniform film thickness and a uniform surface, and a random surface is obtained. In such a photosensitive member, the surface of the photosensitive member, that is, the surface of the photosensitive layer is randomly distributed, so that the toner cleaning property is good, the toner filming can be prevented, and the abrasion resistance is also improved. Further, since the surface of the photoconductor is not roughened, crystallization due to the roughening and uneven image due to uneven cleaning do not occur, and the photosensitive layer is used as a carrier transport layer and a carrier generation layer. Since a large amount of Te can be contained in the carrier generation layer as a function-separated type in which overcoat layers are sequentially laminated, it can be made highly sensitive to coherent light at long wavelengths. Further, since the photosensitive layer is formed with good adhesion and a uniform film thickness, it is possible to suppress an increase in dark attenuation due to repeated use and improve fatigue, and it is suitable for use in a high-resolution electrophotographic apparatus. it can. Further, since the surface of the substrate and the surface of the photoconductor are randomly arranged, no interference fringe pattern is generated on the image even when used in an electrophotographic apparatus that uses coherent light having a long wavelength as exposure light. Further, since the interface of the carrier generation layer, which is one of the constituent elements of the photosensitive layer, is also randomly arranged, the effect of further increasing the sensitivity can be obtained.

The surface roughness of the substrate is 3 μm at the maximum height R _max .
It is necessary to be within the above range of 15 μm. By using the substrate whose surface is roughened as described above, the maximum height R _max is within a range of 0.5 μm or more and 3.0 μm or less, and the ten-point average roughness R _z is 0.35 μm or more.2. 0 μm
A photoreceptor that is randomly exposed within the following range is obtained,
The toner can be satisfactorily cleaned and the interference of exposure light can be prevented. Further, in order to obtain a photoreceptor having good adhesion of the photosensitive layer to the substrate and little increase in dark decay and deterioration of fatigue due to repeated use, the substrate surface must be within the above range. In addition, it is necessary to use a substrate having a surface oxidation degree Al _oxide / Al _metal value of 2.0 or more when the substrate surface is evaluated by X-ray photoelectron spectroscopy (ESCA).

[0010]

Embodiments of the present invention will be described below. Example 1 A surface of a cylindrical Al substrate having an outer diameter of 80 mm was sprayed with air having a pressure of 4 kg / cm ² to roughen a surface by mixing # 220 alumina and water at a ratio of alumina 1: water 3. ,
The maximum height R _max is 13 μm and the center line average roughness _Ra is 1.
The surface was roughened to 7 μm. Then, after washing this substrate with a weak alkaline detergent, it is placed in warm water (temperature 60 ° C to 70 ° C) for 1 hour.
It was dipped for 5 seconds, pulled up at a speed of 10 mm / sec and dried to obtain a substrate for a photoreceptor. This substrate was attached to a rotary support shaft in a vacuum vapor deposition furnace, the substrate temperature was kept at 54 ° C., the bell jar temperature was kept at 40 ° C., 2 × 10 ⁻⁵ Torr to 4 × 10 ⁻⁵ T.
Pure Se was evaporated in a vacuum of orr to form a carrier transport layer having a film thickness of 48 μm. Subsequently, a Se—Te alloy having a high Te concentration is vapor-deposited thereon to form a carrier generation layer having a film thickness of 0.15 μm, and further, a Se alloy containing Te is vapor-deposited thereon to have a film thickness of 3 μm. Form an overcoat layer,
A photoconductor having the structure shown in the schematic sectional view of FIG. 1 was produced. In FIG. 1, reference numeral 1 denotes a substrate having a hydroxide film 12 formed on the surface of an Al substrate 11, on which a carrier transport layer 2, a carrier generation layer 3 and an overcoat layer 4 are sequentially formed. The surfaces of 11, the hydroxide film 12, the carrier transport layer 2, the carrier generation layer 3 and the overcoat layer 4 are all randomly arranged surfaces.

Example 2 A photoconductor was prepared in the same manner as in Example 1 except that the alumina was changed to # 300.

Comparative Examples 1 to 5 Comparative Examples 1 to 5 are the same as Example 1 except that the method of roughening the surface of the Al substrate and the subsequent cleaning method and drying method are changed as follows. Each of the photoconductors of 1 to Comparative Example 5 was produced.

1) The surface is roughened with a bite, washed with trichlene, and trichlene vapor dried.

2) Roughening with a grindstone, washing with trichlene, and trichlene vapor drying.

3) A roughening process was carried out in the same manner as in Example 1 except that # 220 of alumina was changed to # 500.
Wash and dry.

4) Roughening was performed in the same manner as in Example 1 except that # 220 of alumina was changed to # 100.
Wash and dry.

5) Roughening is performed in the same manner as in Example 1,
Wash with trichlene and perform trichlene vapor drying.

The surface roughness (R
_max , _Ra ), surface oxidation degree by ESCA Al _oxide /
The surface glossiness was examined by Method 5 of Al _metal , JIS Z 8741. For each photoreceptor, the adhesion of the photosensitive layer (peeling test using an adhesive tape), the surface roughness of the photosensitive layer (R _max , R _a , R _z ) and the surface shape of the photosensitive layer were examined.
Furthermore, the sensitivity, repeated fatigue, toner filming, and image evaluation were performed for each photoconductor. Table 1 shows the results of the above surveys and evaluations and the overall judgment. The sensitivity is for monochromatic light (semiconductor laser light) having a wavelength of 780 nm. Further, as for repeated fatigue, the photoreceptor is mounted on the fatigue evaluation machine whose process arrangement is schematically shown in FIG. 2, and the process is repeated for 250 cycles, and the potential holding ratio before and after that (when the initial potential in the dark is 100 and after 5 seconds The electric potential of is shown as a percentage). In FIG. 2, 1
00 is a photoconductor, 101 is a charge measuring point, 102 is a developing section potential measuring point, 103 is a main charger, 104 is exposure light, 105 is a transfer charger, 106 is a paper separation charger, 107 is a charge removing light, and 108 is a cleaner. ,
Main charger uses scorotron, transfer is DC
At a voltage of 5.2 kv, paper separation was performed at an AC of 500 Hz (maximum amplitude) at a voltage of 4.2 kv, and a red light emitting diode was used as a static elimination light source. Further, the image was evaluated by a commercially available semiconductor laser printer, and the toner filming was evaluated by repeatedly outputting the image with the same printer. In Table 1, ∘ indicates that it was good, triangle indicates that there was some problem, and x indicates that it was defective.

[0019]

[Table 1]

As can be seen from Table 1, it is clear that the photoreceptors of Examples 1 and 2 are excellent. It can be seen that the roughening method in which a mixed solution of alumina and water is sprayed has a rough surface shape in which the surface of the substrate is randomly arranged and the surface of the photoreceptor is also randomly formed. However, Examples 1 and 2 and Comparative Examples 3 and 3 are preferable. 4 that it is necessary to limit the roughness of the surface of the photoconductor, and the roughness of the substrate surface is 3 μ in R _max .
By setting m to 15 μm, the surface roughness of the photoconductor is R
0.5 μm to 3.0 μm at _max and 0.35 μm at R _z
It is preferable that the thickness is 2.0 μm, and for that purpose, it is preferable that the alumina used is within the range of # 150 to # 400. Further, from Examples 1 and 2 and Comparative Examples 1, 2, and 5, it is effective to coat the surface of the substrate with a hydroxide film by drying with warm water to improve the adhesion of the photosensitive layer and the repeated fatigue of the photoconductor. The value of the oxidation degree Al _oxide / Al _metal evaluated by ESCA of the substrate surface is 2.0.
It is understood that the above is preferable.

[0021]

According to the present invention, the surface of a substrate made of aluminum or an aluminum alloy is sprayed with water containing an abrasive to roughen the surface, followed by washing to clean the surface, followed by hot water drying. By doing so, the surface is randomly placed so that R _max is 3 μm to 15 μm,
Further, it is possible to manufacture a photoreceptor substrate having a hydroxide film formed on the surface thereof and having a surface oxidation degree Al _oxide / Al _metal value of 2.0 or more evaluated by ESCA. By forming a photosensitive layer made of a Se-based material on such a substrate, high-resolution electrophotography in which coherent light having a long wavelength is used as exposure light without roughening the surface of the photosensitive body. It is possible to obtain a Se-based photoconductor suitable for the apparatus.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of a photoconductor of the present invention.

FIG. 2 is a conceptual diagram showing a process arrangement of a photoconductor fatigue evaluation machine.

[Explanation of symbols]

 1 Substrate 2 Carrier Transport Layer 3 Carrier Generation Layer 4 Overcoat Layer 11 Al Substrate 12 Hydroxide Film

Claims (4)

[Claims] 1. A surface made of aluminum or an aluminum alloy, the surface of which has a maximum height R _max of 3 μm or more and 15 μm or less at random, and is evaluated by X-ray photoelectron spectroscopy (ESCA). Surface oxidation degree Al
electrophotographic photoreceptor substrate wherein the value of the _oxide / Al _{me tal} is 2.0 or more. 2. A substrate for an electrophotographic photosensitive member, characterized in that the surface of a substrate made of aluminum or an aluminum alloy is roughened by spraying water containing an abrasive, washed, and then dried with warm water. Manufacturing method. 3. The method for producing a substrate for an electrophotographic photosensitive member according to claim 2, wherein the abrasive is alumina. 4. The electrophotographic photosensitive member substrate according to claim 1, comprising a photosensitive layer made of a selenium-based photoconductive material, the photosensitive layer surface having a maximum height R _max of 0.5 μm or more. Within 10 μm or less, ten-point average roughness R _z is 0.35
An electrophotographic photosensitive member having a random rough surface in the range of μm to 2.0 μm.