JPS5863943A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor free from fatigue phenomenon due to repeated used, by forming an Se type photoconductive layer continuously decreasing in oxygen content from a substrate side toward a surface side on the substrate. CONSTITUTION:A substrate 1 is set to a fixing member 5 in a vapor deposition vessel 4, the air is drawn out of the vessel 4, then, a heater 10 is energized to heat the substrate to 60 deg.C, a heater 7 is energized to melt Se in an evaporation boat 6, the valve 14 of a cylinder 13 to introduce oxygen at the point t1 when Se is uniformly melted, and a shutter 9 is opened to start vapor deposition at the point t2. At the same time, the heater 10 is controlled to gradually raise temp. of the substrate 1 to 75 deg.C, and a flow rate of oxygen is continuously lowered so as to control an oxygen content in a vapor deposited layer to >=100 ppm on the substrate side and to <=20ppm on the surface side, and to <=8,000ppm in the total average content, and so as to deposite 5-100mum thick Se type photoconductive layer. Vapor deposition is completed at the point t3 when Se in the boat 6 has been fully evaporated, and the shutter is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a child photographic photoreceptor that does not cause fatigue even when used repeatedly. Various compositions are taken depending on the electrophotographic process applied,
Basically, a 9゛1 electron-hole pair O is generated from the incident VC of the electromagnetic wave.
It is unique in that charges are caused to drift in the photoconductive layer under an electric field, and is largely dependent on the performance curve of the electrophotographic photoreceptor. In a photoreceptor that has an insulating layer on the surface of the photoconductive layer, an electrostatic image is formed on the insulating layer, and for this purpose, charges are injected into the interface between the insulating layer and the photoconductive layer due to electrification. It is necessary. Examples of such an electrophotographic process include a process consisting of primary charging-am light, AC removal at the same time as image fog light or after image exposure, or charging with a polarity opposite to that of the primary charge, and full-surface side light. The photoconductive layer is B
e. When the photoconductive layer is composed of a P-noodle semiconductor such as SeT, primary charging is performed by negative corona discharge, and positive charges are injected from the support into the photoconductive layer, which is then applied to the photoconductive layer. The electric field transfers the charge to the field l1 between the insulating layer and the photoconductive layer.
I am moving li4c. If it is difficult to inject stains into the support, the amount of insects passing through the interface between the insulating layer and the photoconductive layer can be reduced by uniformly irradiating light from the support side of the photoreceptor immediately before or simultaneously with negative corona discharge. When irradiating light from the support side in this way, the support is made of a light-transmissive material such as net gas or a light-transparent resin film. There is a need.

“For photoreceptors that do not have an insulating layer on the surface of another photoconductive layer, there is no need to inject charge during initial charging, and as an alternative process, if a P conductor is used, the first Applying an electric field to the photoconductive layer by positive corona discharge, image A11oF.

The positive charges generated by this process are transferred to the support side.

Ss and As are conventionally typical photoconductive layers.

Photoconductive layers formed by vacuum evaporation in a Se-containing chamber containing Te, ak, and elements generally have high sensitivity and excellent mechanical chain plates, but it has been pointed out that the characteristics of the photoconductive layer still need to be improved. be done. One of them is repetitive fatigue. That is, m
When the light body is used repeatedly within a short period of time, the potentials of the dark and bright parts of the electrostatic image become smaller than the initial ones, and the contrast decreases f1! be noticed. This is the so-called photoreceptor 12
) [Explained as a labor phenomenon, due to electrical defects in the photoconductive layer, charges are trapped in the photoconductive layer and become space charges. It is presumed that this causes a decrease in the dark St position.

In order to obtain a high-contrast electrostatic image with good reproducibility, it is essential to have a photoconductive layer that does not cause fatigue. Therefore, the main object of the present invention is to provide a photoreceptor which does not exhibit the fatigue phenomenon described above even when the photoreceptor is used repeatedly.

The present invention provides a cryptographic photoreceptor having an Se-based photoconductive layer containing acid Continuously decreases, and the content of #It element on the support side is 100
ppm or more and 20 ppm or less on the front side.The photoconductive layer according to the present invention contains oxygen atoms as impurities, so that the distribution of #l bulk atoms in the photoconductive layer is similar to that of the support. It has a uniform distribution in the plane approximately parallel to the surface, but non-uniform distribution in the thickness direction, and the oxygen atom-containing lid is more distributed on the support side than in the center of the layer. Having a large meeting like this
The photoreceptor according to the present invention, which is equipped with an S-based photoconductive layer, has better charge mobility than conventional ones, and positive charges are trapped in the IIA photoconductive layer that drifts in the photoconductive layer, reducing residual potential and dark potential. Electrophotographic properties without fatigue can be achieved by compensating for electrical defects in the photoconductive layer that may cause a decrease in photoresistance. Therefore, it is particularly effective as a photoreceptor for high-speed copying, for example, when the same part of the photoreceptor is repeatedly subjected to an electrophotographic process with an interval of 2 seconds or less.It also has excellent charge retention properties. There is. Note that the content of oxygen contained in the entire leading conductive layer is ao
It is preferably ooppm or less, particularly 40001)P1m or less. In addition, the acupuncture content on the support side is 200 pp
A typical example of the structure of an electrophotographic photoreceptor for which 0 m or more is particularly suitable is 81 &
! ! Q and Iris 2 are shown.

The photoreceptor shown in Figure 111 is composed of a support iS and a conductive layer 2.The photoreceptor of the second WJ has an insulating layer 3 on its surface. It is transparent.

In the photoreceptor shown in FIG. 3, a photoconductive layer 2' having a higher sensitivity than the photoconductive layer 2 is provided between the insulating layer 3 and the photoconductive layer 2. In the present invention, the # wires contained in the photoconductive layer act to quickly inject hole charges from the support side, and furthermore, when the charges drift in the photoconductive layer, they are trapped in the photoconductive layer. It acts to compensate for electrical defects such as

The thickness of the photoconductive layer is set appropriately depending on the electrophotographic characteristics to be applied, but it is usually 1 to 100μ for a thickness of 5 to 100μ.
It is 0 to 80μ.

Further, a photoconductive layer containing elements such as Te HAs and Sb can also be used. As a support,
Examples include metals such as AI, N1, brass, Cu, and Ag, glass, resins such as polyester and polyethylene, paper, glass, and ceramics.

The insulating layer is usually made of resin.

Examples of effective resins include polyester,
Polyparaxylylene, polyurethane.

Polycarbonate, polystyrene, etc. ◎JII
The highly sensitive photoconductive layer shown in Figure 3 is appropriately selected according to the commonly used electrophotographic process, and includes, for example, ZnO, CdS
, polyvinylcarbazole, and other materials are used. Particularly regarding Ss-based materials, for example, 8e-To,
It is made of 118e alloy materials such as 5s-8b, 5e-Bi, 5a-AI, etc.

The thickness of this highly sensitive photoconductive layer is preferably in the range of 1 to 15 microns, particularly 1 to 5 microns.

Example 1 As shown in FIG. 4, a 100×100 jJHDAj support 1 is placed at a predetermined position in a vapor deposition tank 4. The support 1 is heated by a round heater 10M881.
They are fixed to the fixing member 5 with a distance of m.

Next, 5 ets of quartz vapor deposition boat 6 K#1*5 n1ne were filled. A tungsten spiral heater 7 is provided on the vapor deposition boat 6. The vapor deposition boat 6 is equipped with a round stainless steel pipe 12 for introducing oxygen into an oxygen cylinder 1111M provided outside the vapor deposition tank.

Next, the air in the deposition tank 4 is evacuated in the direction indicated by the arrow 11, and the vacuum 1 is set to 5 x 1 G-' torr. Next, heal
The temperature of the support 10 is raised to 60° C. by igniting O and kept at this temperature.

Hereinafter, changes over time in substrate temperature, deposition rate, and degree of vacuum during deposition will be explained with reference to FIG. 5.

The spiral heater 7 on the first boat 6 is ignited, and the deposition boat is heated to taoo℃, and the temperature inside the deposition boat is O8・'kll.
I melt. The Ss in the deposition boat melts uniformly and takes 7't.
Atl, oxygen is introduced into the oxygen cylinder 13 so that the pulp is 14 tM and the degree of vacuum in the vapor deposition tank is 1.5 x 10-4 torr K, and then the shutter is opened at 1R to start vapor deposition on the support. As shown in Figure 115, the amount of oxygen introduced was gradually increased to 1. tJR2 and 2 true flows at the end of Ss deposition II
cR is set at 1111 JIN to gradually raise the substrate temperature as shown in FIG. 5, and the temperature is controlled so that it reaches 75° C. at the end of S@O vapor deposition.

At a point t1 when S. in the deposition boat is almost gone, the current to the spiral heater 7 is cut off and the shutter 9'ic is closed to complete the deposition.

The thickness of the vapor deposited film is 60μ, and 6 parts. It was 50p- at a position 5μ from the surface side, and 11000pp at Ls (D position) from the support side.

Then, the following method is used to obtain the desired characteristics.

A positive corona discharge with a power supply voltage of 6 KV is applied to the photoconductor, the surface potential is charged to aoo v Vc, the entire surface of the photoconductor is immediately irradiated uniformly, and the static electricity is further removed by KAC corona discharge.90This process is continued for 2 seconds. As shown in the straight line of M6WJ, there was no change in the surface potential after irradiation of all meters from 11th to 100th, and there was almost no fatigue due to repeating Ov. was not recognized.

The surface of the photosensitive plate was coated with polyurethane resin to a thickness of 25 μm, and then the next fixing process was carried out.

C:) A negative corona discharge of 6Kv is performed to reduce the surface potential to (
1) 2000V K band and then 06K as secondary charging
When a positive corona discharge of V is performed to eliminate static electricity from the insulating layer, and then the entire surface is irradiated uniformly, a θgoovo surface potential is obtained. As a result of repeating this process at a cycle of 4 s@e, as shown in the straight line B in Figure 116, <11g1 to 10
There was no change in the surface potential after irradiation after full-surface exposure up to the 0-th mark. (9) No fatigue phenomenon was observed.

Reference Example 1 A photoconductor was prepared in the same process as in Example 1 except that the introduction of oxygen between t and t1 in Example 1 was not carried out. ■ Go to 6KV positive corona radiation 11', ■ 600VK11F, immediately irradiate the photosensitive plate all m*, and j! Static electricity was removed using AC corona discharge. As a result of repeating this process 100 times with a 2-sec period, the surface potential gradually increased with the number of repeats, and reached 200 V at the 100th repeat, as shown in Figure 1C of the IG diagram.
When the temperature increased to K, repeated fatigue phenomena occurred.Furthermore, polyurethane*m was applied to the ON side of the photoreceptor to a thickness of 25 seconds, and further O fixation was carried out. 06KV O negative corona release
The surface of the insulating layer is exposed to 02,000V K IF range, and then a 6KV O positive corona discharge is performed as a secondary charge to eliminate static electricity on the insulating layer surface.Then, the entire surface is irradiated uniformly to 0750V.
The VO surface potential showed 0 such a process at 2 s@e
111 in Figure 6 of the 6th diagram that goes repeatedly at regular intervals! IDK: As shown, the surface potential after the entire surface irradiation gradually decreases with the number of repetitions, and at the 100th time, ToD<repetition fatigue phenomenon occurs at θ650V.

As described above, according to Example 1 and Reference Example 1, the electrophotographic photoreceptor of the present invention can be applied to a process that is applied to a photoreceptor without an insulating layer, or to a process that is applied to a photoreceptor with an insulating layer. It has been recognized that it exhibits excellent characteristics.

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views showing one embodiment of the photoreceptor according to the present invention, respectively.0 Figure 4 is a configuration diagram of a vapor deposition apparatus used for manufacturing the photoreceptor.0 Figure S 27 is a vapor deposition operation for forming a photoconductive layer. Figure 1116 is a graph showing changes in surface potential due to use of the photoreceptor o<D. l... Support, 2... Photoconductive layer, 3... Insulating layer,
XaIm to JI! 1□! IH5; 1st cotton paste j

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor having a Se-based leading W1 layer on a support, the cell content is uniform on the plane parallel to the support, but continuously from the support side to the side. and the content of 0tIt volume on the support side is loo
An electrophotographic photoreceptor characterized in that the content is at least ppm and at most 20 ppm on the front side.