JPS5953851A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To prevent softening of a photosensitive layer due to temp. rise and to enhance resistance to crystallization, by using Se-As for a lower layer and adding antimony to the surface layer. CONSTITUTION:An Se-As alloy layer 2 is laminated on a conductive substrate 1 in a 20-100mum thickness, and further on this layer an Se-Te-Sb alloy layer is laminated in a <=10mum thickness in contents of <=10% As, <=50% Te, and <=10% Sb, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electrophotographic photoreceptor. Selenium has traditionally been the most important photosensitive material for electrophotographic photoreceptors, and the namorphous selenium deposited on the substrate can withstand repeated use and is used as a photoreceptor with high resolution and less fatigue. Has a proven track record. However, with selenium alone, the spectral sensitivity does not extend to long wavelengths and it lacks panchromaticity.
It has the disadvantage that it easily crystallizes when the ambient temperature rises and loses its function as a photoreceptor, and that it cannot be used in the copying process due to its low hardness. As a means to improve some of these drawbacks, photoreceptors with excellent panchromatic properties have been put into practical use by sensitizing them with various additives to extend the spectral sensitivity toward longer wavelengths. However, in this case, in the most commonly used Teyal sensitization, the amount of tellurium added is 10% in both the full-layer selenium-selenium-tellurium alloy and the functionally separated selenium-selenium-tellurium alloy.
In the above range, as can be seen from the fact that the crystal transition point is lower than that of selenium, there is a weaker thermal influence (thereby, there is a possibility that crystallization will proceed), which may be a major drawback depending on the application. In addition, when other additives are used, there are disadvantages such as production technology difficulties and the inability to maintain the characteristics of a photoreceptor, but practical use of arsenic has not been attempted. Its characteristics are that as the amount of arsenic added increases, the sensitivity increases, and it is possible to have effective sensitivity up to around 700 nm.It also shows good values for both crystallization resistance and hardness. things are known.

However, on the other hand, Okawa's addition of arsenic causes problems during use, such as large fatigue with long wavelength light and large changes in properties over time. The present invention solves the above-mentioned drawbacks and provides an electrophotographic photoreceptor that has high sensitivity, excellent environmental resistance, and excellent all-color properties, and has improved fatigue and aging properties. In the present invention, selenium and tellurium antimony alloy are laminated on top of the selenium-arsenic alloy. In the case of this structure, by using selenium tellurium in the lower layer, softening of the photosensitive layer due to temperature rise is prevented, and by adding antimony to the surface layer, crystallization resistance is improved. It is also possible to adjust the sensitivity by changing the amount of tellurium added at appropriate times. With such a layer structure, it is possible to produce a photoreceptor with high sensitivity and good environmental resistance without being affected by the addition of a large amount of arsenic. FIG. 1 is a side view of the structure of an electrophotographic photoreceptor according to an embodiment of the present invention. In the figure, 1 is a conductive support made of aluminum or the like, 2 is a selenium-arsenic alloy layer, and 3 is a selenium-tellurium-antimony alloy layer. . 1 conductive support and 2 selenium
- Usual changes and modifications such as interposing an intermediate layer between arsenic alloy layers to improve electrical or mechanical properties are included in the present invention. It goes without saying that the scope of the present invention also includes the inclusion of other impurities in each alloy layer to the extent that they do not significantly affect the properties.

The following will be explained using examples. An aluminum neem drum measuring 120 mm in outer diameter and 300 mm in length and having a mirror-finished surface was washed with trichlorethylene or the like and then subjected to an appropriate surface treatment. This drum was placed in a vacuum deposition tank, and below it a selenium-arsenic alloy containing 5% arsenic was placed in the first evaporator, and a second evaporator was placed in which a selenium-tellurium alloy containing 10% tellurium was placed. A third evaporation source containing antimony was installed. Furthermore, a shutter that could be opened and closed at will was installed above each deposition source. While keeping the temperature of the aluminum drum at 80°C, the inside of the tank was evacuated and vapor deposition was started. First, the tFS1 evaporation source was heated by applying electricity to deposit 55 selenium-arsenic alloy layers, and after closing the shutter, the electricity was turned off. Furthermore, a second evaporation source, a third
The evaporation lake is electrically heated and the shutter is opened when the evaporation rate stabilizes to a desired value. A 5μ co-deposited layer of tellurium and antimony was deposited, and the shutter was closed to turn off the electricity.

Thereafter, the vacuum was broken and the photosensitive drum was taken out from the tank, and the photosensitive drum was a photosensitive member in which 5 μm of a selenium-tellurium-antimony alloy layer containing 4% antimony was laminated on a selenium-arsenic alloy.

This photosensitive drum according to the present invention is referred to as Sample 1, and for comparison, photosensitive drum samples 2 and 3, which are not according to the present invention, do not use antimony but have selenite as an upper layer.

After leaving these samples in an environment of 50°C, an image test was performed. Regarding sample 3, after 100 hours, white spots appeared on the halftone image due to the generation of crystal nuclei, and after 200 hours, white spots appeared on the halftone image. has spread all over the place.

On the other hand, samples 1 and 2 had image quality that was the same as the initial image even after 300 hours. As another evaluation method, a continuous image test was conducted using one copying machine at an ambient temperature of 35°C. The temperature change inside the copying machine at this time rose to 42° C. about 30 minutes after the start of the test, and remained fairly stable thereafter. This indicates that the temperature of the photosensitive drum inside the copying machine also gradually rises.

The results of the continuous image test are as shown in Table 1. Sample 1, which has a selenium-arsenic alloy layered in the lower layer and a selenium-tellurium-andimony alloy layered in the upper layer, remained unchanged even after 50,000 copies were made and was stable in a high-temperature environment. This shows that it can be used.

The large number of scratches on Sample 2 indicates that the photoreceptor is affected by changes in hardness due to not only the surface but also the internal temperature. As is clear from the above description, according to the present invention, an electrophotographic photoreceptor can be obtained that has high sensitivity, good resistance to four environmental conditions such as crystallization and hardness, excellent panchromaticity, and improved change over time. It has a wide range of uses, including copying machines and printers, and has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of the structure of an electrophotographic photoreceptor according to an embodiment of the present invention. 1 is a conductive support, 2 is a selenium-arsenic alloy layer, and 3 is a selenium-tellurium-antimony alloy layer. Shindengen Industries Co., Ltd.

Claims (1)

[Claims] +11 An electrophotographic photoreceptor comprising a selenium-arsenic alloy layer laminated on a conductive support, and a selenium-tellurium-antimony alloy layer further laminated on top of the selenium-arsenic alloy layer. (2) The arsenic concentration in the selenium-arsenic alloy layer is 10% or less, and the tellurium concentration in the selenium-tellurium-antimony alloy layer is 5% or less.
The electrophotographic photoreceptor according to claim 1, characterized in that the antimony concentration is 0% or less and the antimony concentration is 10% or less. (3) The electrophotographic photosensitive material according to claim 1 or 2, characterized in that the film thickness of the selenium-arsenic alloy layer is 20 to 100P, and the film thickness of the selenium-tellurium-antimony alloy layer is IOμ or less. body.