JPS59155852A - Electrophotographic sensitive body and its manufacture - Google Patents

Abstract

PURPOSE:To improve reproducibility of electrophotographic characteristics, sensitivity to He-Ne laser beams, and heat resistance and to extend a life by making the alloy element concn. of the Te-contg. layer of an Se type photosensitive body almost constant in the film thickness direction. CONSTITUTION:The alloy element concn. of the Te-contg. layer (Te-Se alloy layer) 4 of an Se type photosensitive body formed on a conductive substrate 1 is made almost constant in the film thickness direction. The Se photosensitive body is obtained by laminating an Se layer 3 and the layer 4 successively on the substrate 1. The layer 4 is formed by vapor deposition at a temp. about 100 deg.C higher than that of the liquid phase line of the binary constitutional diagram. The layer 4 thus formed makes the content of Te constant in the film thickness direction, enhances glass transition point and heat resistance, and extends its life, and further, eliminates scattering of electrophotographic characteristics, and enhances reproducibility. Since the Te content has correlation with, e.g. sensitivity to He-Ne laser beams, the sensitivity can be held at the optimum value by controlling the Te content.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrophotographic photoreceptor and a method for manufacturing the same, and particularly to a photoreceptor having SeJm' containing Te.
The present invention relates to an electrophotographic photoreceptor that has high sensitivity at long wavelengths, excellent heat resistance, and a long life, and a method for manufacturing the same.

[Prior art]

2. Description of the Related Art It is well known that photoreceptors mainly made of Se (selenium) are used in laser beam printers, copying machines, and the like that utilize electrophotography. In addition, as devices using such photoreceptors become smaller and more versatile, light sources () (
E-N e lasers and semiconductor lasers have been used, and the photoreceptor has come to be used by doping Se with Te (tellurium), As (arsenic), etc. to extend its sensitivity range to the full length wavelength. Further, in the production of the photoreceptor, vacuum evaporation using an alloy evaporation method is mainly used from the viewpoint of mass production.

However, in the alloy explosion method, due to the difference in vapor pressure of the alloying elements, the alloying elements in the vaporized material have a distribution with a significant concentration gradient, resulting in low reproducibility of vapor deposition and variations in electrophotographic properties. Ta.

In general, a photoreceptor with a film structure having a 5e-Te alloy layer with a large concentration gradient of alloy elements on 5eJfiI, or a photoreceptor with a film structure in which a Be layer or Se alloy layer' (I-laminated) is further formed on the top surface. However, in both cases, they have the drawbacks mentioned above.In addition, in the former case in particular, it is difficult to control the thickness of the alloy layer, making it difficult to obtain an alloy layer with the desired composition. Even if obtained, the reproducibility was low.Furthermore, among the electrophotographic characteristics, it had the drawback of large dark decay.Also,
In the latter case, there are problems with heat resistance on the surface layer side, and thermal instability increases due to temperature rise around the photoreceptor during repeated use, resulting in contamination of the surface of the photoreceptor with toner, etc. This resulted in the occurrence of so-called filming or the like.

[Purpose of the invention]

An object of the present invention is to provide a Be photoreceptor having a Te-containing layer with good reproducibility of electrophotographic properties by chemotacticing the alloying element concentration 't - of the Te content, and to improve He-N
The present invention provides an electrophotographic photoreceptor that is highly sensitive to e-lasers, etc., has excellent heat resistance, and has a long life.

[Summary of the invention]

In order to achieve such an object, the present invention makes the alloying element concentration of the Te-containing layer almost constant in the film thickness direction, and as a method of forming it, the Te-containing layer is made of Se-'
The vapor deposition is performed at a heating temperature within a temperature range of 100 C higher than the liquidus line in the 1'e binary phase diagram.

Hereinafter, the present invention will be explained in detail using Examples.

[Embodiments of the invention]

Hereinafter, all embodiments of the present invention will be explained.

FIG. 1 is an explanatory view showing an example of an electrophotographic photoreceptor and a method for manufacturing the same according to the present invention. In the same figure, At
The drum 10 surface is cleaned by a chemical cleaning treatment, and 5
A bzSea layer 2 is formed by vapor deposition. The At drum 1 has an outer diameter of 261 M, an inner diameter of 250 mm, and has a JIS, A-6063/TE-T5 surface processed to a mirror finish.
A length of 4'30+m is used. Also 8b2Se
The substrate temperature was 20 to 30 C for vapor deposition, and a -Km mandrel type Se# deposition apparatus manufactured by Japan Vacuum Technology Co., Ltd. and equipped with substrate heating and cooling equipment was used as the evaporation apparatus.

Furthermore, B is sequentially formed on the upper surface of the S bz S es layer 2.
An e-layer 3 and a 5e-Te alloy layer 4 are deposited.

The material was deposited using the above-mentioned vapor deposition apparatus, and the vapor deposition temperature was raised to 50C to 8 (L). Among these, the formation of the SE-'RE alloy layer 4 was performed by evaporation of various compositions. 3e-T6 alloy t-mack 7.-/'7 SE7 author, Con5titution of13inar
y A110Y8; evaporated by heating above the liquidus temperature of the 5e-Te binary phase diagram of 1958. The above 8e-Te binary phase diagram is shown in FIG. The heating temperature at this time is preferably 100C above the liquidus side temperature.
High temperature range is best, optimally liquidus temperature, 92
A temperature 50C higher than 0C is selected. The reason is that when Be-'1'e heavy alloy is heated and evaporated below the liquidus temperature,
In the Be-'1'e distilled film that is formed, the Te concentration in the film is not constant, and when the temperature exceeds the liquidus temperature by 100C, the bumping phenomenon becomes noticeable and the surface defects of the deposited film are greatly generated. Because it will be.

5e-I116 alloy layer 4 of the photoreceptor formed as above
As a result of quantitative analysis using an ion micro analyzer (manufactured by Hitachi, Model IMA-5), we found that the amount of Te in each composition of the evaporated alloy and the 5e-Te alloy formed were as shown in Figure 3. It has been found that the IfeA degree of the stabilizer in the alloy exhibits a linear correlation.

By the way, when the amount of Te in the vaporized alloy is 25%, the heating temperature is 240tl:', 253t:, 5e-T of 290C.
When the relationship between the amount of Te in the 5e-Te alloy layer and the thickness of the e-alloy layer was investigated, it was found that the relationship is as shown in FIG. Characteristics α, β, and r are obtained when the boat temperatures, which are heating temperatures, are set to t240tT, 253C, and 290C, respectively. As can be seen from this experimental result, the heating temperature was 253C.
It can be seen that within the range from 290C to 290C, the amount of Te in the 3e-'l'e alloy layer is almost constant in the direction of the alloy layer.

Furthermore, as shown in FIG. 5, the thickness of the 5e-Te alloy layer is taken as the horizontal axis and the Te concentration in the alloy layer is taken as the vertical axis.
When examining the distribution of degrees, characteristic A and characteristic B are obtained from the free surface surface.
As shown in Fig. 2, it was observed that the Te concentration remained almost unchanged regardless of the film thickness, and the variation was within ±10% even considering the analysis accuracy for each composition.

△Here, a photoreceptor with a se-'l'e alloy layer having a Te concentration of 20% by weight, which has a sensitivity of about 5rnJ/m'' to a He-Ne laser, is prepared, and the film thickness of the chemotactic part is 5e-1: [Charge retention property against change in film thickness of Te alloy layer (defined as surface potential after 5 seconds of charging/surface potential during charging)
Upon investigation, it was found that the result was as shown in Figure 6.

From the figure, the charge retention property increases when the thickness of the alloy layer is less than 0.5 μm and exceeds 1 μmf. For this reason, the preferred film thickness is between 0.5 μm and 10 μm, but the most desirable range is between 1 μm and 5 μm.

Be-' consisting of 3.5 μm of the optimum film thickness within this range
We prepared a photoreceptor with an I'e alloy layer thickness, mounted it on a laser beam printer equipped with a He-Ne laser light source, and conducted a full printing performance test. As a result, it showed good printing performance with no filming or the like. It was found that a long life can be achieved. This is because Te has a large concentration gradient as previously given.
Differential scanning calorimetry revealed that the Te-containing layer, which has a chemotactic concentration, has a higher vitrification transition temperature than the Te-containing layer, and has improved heat resistance. It is something.

Furthermore, by making the Te concentration in the 5e-Te alloy layer constant, any desired composition of the deposited film can be obtained, and the reproducibility of the composition in the deposited film of the same evaporated alloy becomes excellent. It is also possible to create a multilayer structure consisting of Se-'I'e alloy layers with a desired composition.According to experiments, a trace amount of a third element such as sb, As, or In is added to the Se-'I'e vaporized alloy. However, it was found that the constant alloying in the deposited film did not change.

In the example described above, the amount of Te in the 5e-Te alloy layer is 12
It is assumed that Tet is 0 W%, but it can be seen that Tet has a correlation with the sensitivity when a He--Ne laser is used as a light source, for example.

Figure 7 shows the amount of He-N versus Te in the 5e-Te alloy.
It is a graph showing the relationship between e-laser sensitivity.

If you want to maintain He-N e laser sensitivity at the optimum sensitivity (0.13 to 0.2 m2/mJ), S e-'T
Tet in the e-alloy layer can be selected within the range of 17.5 to 21 W%.

〔Effect of the invention〕

As is clear from the above description, the electrophotographic photoreceptor and the method for manufacturing the same according to the present invention improve the conventional shortcomings of long-wavelength sensitive Be-based photoreceptors having a Te-containing layer. An excellent photoreceptor can be obtained. In particular, as mentioned above, the reproducibility of photoreceptor manufacturing is excellent, and the vitrification transition temperature is increased by forming an alloy layer with a constant composition, which improves the filming resistance in actual use of a laser beam printer.
A photoreceptor with improved heat resistance and long life can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of an electrophotographic photoreceptor and a method for manufacturing the same according to the present invention, including a configuration diagram showing a cross section of the photoreceptor;
Fig. 2 is a Se-'l'e binary phase diagram, Fig. 3 is a graph showing the Te concentration in the constant part of the alloy layer against the amount of Te in the evaporated alloy, and Fig. 4 is a graph showing Be-'l'e depending on the heating temperature. A graph showing the relationship between the film thickness of the 'e alloy layer and the amount of Te in the Se-'l'e alloy layer.
Figure 6 is a graph showing the relationship between the thickness of the alloy layer and the Te concentration in the alloy layer when Se-
It is a graph showing the relationship between 'l'e-l in the 'l'e alloy layer and He-Ne laser sensitivity. 1-At drum, 2.=8bzSes layer, 3..
・Se layer, hair / Figure 2 'Ee Te combination *% ノH'j- (2μm) 51 yen] (2) Se-Te combination' layer, yr reflection f'+ (Pyn-) Hatq diagram Se -7e Taiso Tsuji layer middle arTe%< uyti no 1st
Continued on page ■ Applicant Hitachi Koki Co., Ltd. 2-6-2 Otemachi, Chiyoda-ku, Tokyo

Claims (1)

[Scope of Claims] 1. An electrophotographic photosensitive member having a Te-containing layer on a conductive substrate, characterized in that the alloy element concentration of the Te-containing layer is approximately constant in the film thickness direction. body. 2. The photoreceptor has SeJm and Se-' on the conductive substrate.
An electrophotographic photoreceptor according to claim 1, having a structure in which 1'e alloy layers are sequentially laminated. 3. In the Se-based photoreceptor having Te-containing 1- on the conductive substrate, the Te content is a Be-'fe binary phase diagram. 1. A method for producing an electrophotographic photoreceptor, characterized in that vapor deposition is performed at a heating temperature in the range of 100C higher than the liquidus line.