JPS60166954A - Electrophotographic sensitive body made of selenium - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body good in repeating fatigue resisting characteristics by treating a molten Se material obtained by vacuum distillation, in an inert gas amt. to prepare granular Se material, and vapor depositing it on conductive substrate to form a photosensitive layer. CONSTITUTION:An Se material having a prescribed comspn., such as Se-Te alloy, is distilled in vacuum, the obtained molten material is collected and condensed in an atm. of inert gas, such as N2 to form ingots. They are heated again in the inert gas amt. to melt them, and dropped into water to form granules. The intended electrophotographic sensitive body of Se is obtained by locating this obtained granular Se material at the position of the evaporation source of a vapor deposition device, evaporating and depositing it on a conductuve substrate to form a photosensitive layer. This photosensitive body is not deteriorated in copied image quality even by repeated uses, and it can form always sharp images.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a selenium photoreceptor for electrophotography having a photosensitive layer made of a selenium material deposited on a conductive support.

[Prior art and its problems]

A selenium photoreceptor widely used in electrophotography is manufactured by vacuum-depositing a selenium material such as selenium, a selenium alloy, or a selenium compound onto a conductive support made of aluminum or the like. Conventionally, this type of photoreceptor has had problems such as fatigue characteristics when repeatedly operated in an electrophotographic apparatus, such as a decrease in the contrast of a copied image due to a decrease in surface potential, or a decrease in image quality due to an increase in residual potential. In order to suppress the increase in residual potential, for example, impurities or oxides have been added to the selenium material, and some effects have been obtained. However, no significant measures have been taken to suppress the decrease in surface potential.

[Purpose of the invention]

In view of this, it is an object of the present invention to provide a selenium photoreceptor for electrophotography in which repeated fatigue properties, particularly reduction in surface potential, are suppressed.

[Key points of the invention]

The selenium photoreceptor for electrophotography according to the present invention achieves the above object by having a photosensitive layer formed by vacuum evaporating granular selenium material and depositing it on a conductive support.

[Embodiments of the invention]

Conventionally, in order to produce a photoreceptor having a photosensitive layer made of a selenium-tellurium alloy, commercially available 5.5% by weight Te
The Se alloy containing Se alloy is heated to 400°C and distilled at 1 Torr, and the liquid adhering to the vessel wall is collected into the atmosphere and made into an ingot. This ingot is heated to 380°C in the air to remelt it and dropped into water to create a granular selenium-tellurium alloy.The granular selenium-tellurium alloy is placed in an evaporation source and evaporated, and then exposed to light on a support. layers were deposited. On the other hand, in the embodiment of the present invention, in order to create a granular selenium-tellurium alloy, the liquid selenium-tellurium alloy after vacuum distillation is solidified into an ingot, remelted, and granulated in a similar manner in a nitrogen atmosphere. I went with the temperature.

As described above, 5e02 in the material was analyzed by infrared spectroscopy for 40 t of material prepared by the conventional method for comparison with the material prepared by the example different from the conventional method. For infrared spectroscopy, a 76QCIIL heater (Te02) and a 250 cnt (Se 8 ring
) was calculated using the following formula.

Table 1 shows the oxidation degree of the materials measured by the conventional method and the examples of the present invention.

Table 1 It can be seen from Table 1 that the degree of oxidation of the materials obtained by the examples of the present invention has less variation than that of the conventional method, and is a low value of 10 or less.

Next, these eight types of materials were placed in an evaporation source and vacuum-deposited onto the aluminum photoreceptor substrate. Substrate temperature is approximately ω℃, pressure is 10 Torr *Evaporation source temperature is approximately ωμ at 340℃
A charge transport layer with a thickness of m was obtained. Then on top of this Se -5
, 5 wt % Te, a 5e-12 wt % Te alloy prepared in a nitrogen atmosphere by the conventional method and the present invention was used as a vapor deposition raw material to form a charge generating layer with a thickness of 5 μm. In this way, four photoconductors A-1 were produced using conventional vapor deposition raw materials.
, A-2, A-3, and A-4, and four photoreceptors B-1, B-2, B-3, and B-4 of Examples of the present invention were obtained.

Next, the temperature characteristics and fatigue characteristics of these photoreceptors were evaluated.

(1) Evaluation of temperature characteristics Evaluation of temperature characteristics is based on two points on the temperature dependence curve of surface potential as shown in FIG. The temperature of each photoreceptor is 20
Table 2 shows the temperatures at two points obtained by raising the temperature from ``C''.

As shown in Table 2, it can be seen that the photoreceptors according to the examples of the present invention have better temperature characteristics and are more stable against temperature increases.

(2) Evaluation of Fatigue Characteristics Eight photoreceptors were subjected to the electrophotographic process 1000 times in a copying machine, and the amount of charge reduction was calculated based on the difference after the 1st to 5th 1000 times. In addition, the half-attenuation exposure amount and residual potential after repetition were measured. Table 3 shows the results.

Table 3 As can be seen from Table 3, the selenium-tellurium alloy photoreceptor according to the present invention has better fatigue characteristics in terms of charge reduction, and other characteristics are different from photoreceptors using conventional vapor deposition materials. do not have. It is presumed that this improvement in properties is due to the low degree of oxidation of the vapor deposition raw material.

Similarly, for pure Se and Se compounds other than 5e-Te alloys, improvements in fatigue properties were observed in selenium photoreceptors with photosensitive layers formed using vapor deposition raw materials prepared in a nitrogen atmosphere so as not to come into contact with oxygen. It was done.

[Effect of the invention] The obtained selenium material with a low degree of oxidation is used as a vapor deposition raw material to form a photosensitive layer of an electrophotographic photoreceptor to improve fatigue characteristics. For example, a functionally separated selenium-tellurium alloy photosensitive layer is formed. In contrast to conventional photoconductors using evaporation raw materials made in air, the photoconductor used for secondary photography does not reduce the quality of copied images due to repeated repetitions, and is always Extremely clear images can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a temperature dependence diagram of surface potential showing a method for evaluating temperature characteristics of a photoreceptor in order to understand the effects of the present invention. 9th crystal 1st floor

Claims (1)

[Claims] 1) It has a photosensitive layer formed by evaporating a granular selenium material created by treating a liquid selenium material having a predetermined composition obtained by vacuum distillation in an inert gas atmosphere and depositing it on a conductive support. A selenium photoreceptor for electrophotography characterized by the following.