JPS5842054A - Method for vapor depositing electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor having no fluctuation of sensitivity and forming a sharp image, by maintaining temp. of the substance to be evaporated not below its crystallization temp. and not above its melting temp., at the early stage of vapor deposition for a prescribed time in manufacture of the photoreceptor by vacuum vapor deposition. CONSTITUTION:Selenium-tellurium alloy or the like is placed on an evaporation boat and set in a vacuum vapor deposition apparats. The alloy is maintained not below the crystallization temp. and not above the melting temp. for a prescribed time so as to adjust heat balance between absorption and emission of heat to substantially negligible amount. An intended electrophotographic receptor is obtained by liaminating the alloy through the vacuum vapor deposition method on a conductive substrate made of aluminum, copper, nickel, or the like. Thus permitting fractionation due to the vapor pressure difference between tellurium and selenium to be prevented, and therefore uneven concn. distribution of tellurium to be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor deposition method for producing a secondary photographic photoreceptor, and more specifically, to suppress the dispersion of the electrophotographic photoreceptor at the initial stage of vapor deposition. The temperature is kept above the crystallization temperature and below the melting temperature of the evaporated substance for a certain period of time.
Concerning how to hold.゛The photoreceptor for electrophotography is 400~
It has excellent spectral sensitivity to light in a wide range of waves and regions around 700 nm, has a low dark decay rate, and has a large light decay rate when irradiated with light and has excellent photosensitivity. It is necessary to improve properties such as low optical fatigue and repeated fatigue, residual potential not increasing with use, good heat resistance, and no crystallization of photoreceptor layer components due to use.

In order to satisfy these various properties, various photoreceptors such as telluruse V) type photoreceptors and tellurium arsenic-7-based photoreceptors are produced.

It has been manufactured by depositing 14111- on a conductive substrate such as aluminum, steel, or aluminum using a vacuum evaporation method or the like.

However, in the production of these photoreceptors, when an alloy Ill such as tellurium/acrylic is formed by vacuum evaporation, the photosensitivity of the resulting photoreceptor becomes uneven, resulting in sharp print images. The disadvantage of not being able to form was particularly severe.

This non-uniformity in photosensitivity is caused by the non-uniform concentration distribution of the components in the uppermost selenium-based alloy layer of the integrated photosensitive area. Due to the large vapor pressure difference between the
゛Also, at that time, the concentration of the component that causes this increases#
First, the non-uniformity has become significant, and as a result, the sensitivity of the photoreceptor has large variations, making it extremely difficult to control the photosensitivity.

For example, in a selenium-tellurium/selenium/aluminum photoreceptor, the tellurium component is heterogeneous! It showed an IIf distribution.

In this case, the method for reducing the non-uniform distribution of tellurium concentration is the fludge vapor deposition method, but this method
i. The pupil filling method is more complicated than the normal vapor deposition method, making it unsuitable for mass production. Also, the evaporation source must be kept at a high temperature, which may cause crystallization of the selenium film on the photoreceptor. However, it is not practical because it has drawbacks such as being undesirable because it causes a decrease in the durability of the photoreceptor.

For this reason, in the current method, a certain degree of fractional distillation is unavoidable, and the vapor deposition operation is carried out at a relatively low temperature in a resistance heating boat.

The purpose of Misfire #4 is to provide a manufacturing method using the laminated photosensitive t-S* method that overcomes these drawbacks of tgL and has no variation in sensitivity.

From the analysis of experimental data up until now, it has been found that the factors contributing to the variation in photosensitivity of the photoreceptor include the grain length distribution of the single shot charge, the degree of crystallinity, and the deposition source temperature e4. However, this is different from the results of previous studies.

Rather, attention should be paid to the thermophysical properties of the evaporated substance, that is, the heat balance during evaporation, and the heat treatment of the M-emitting substance at the initial stage of evaporation has a large effect on the evaporation rate, which affects the concentration distribution of alloy components (for example, tellurium). What is the 6th invention that has been found to give? It was completed based on knowledge such as:.

To explain this point in detail, as shown in the schematic diagram of differential thermal analysis in Figure 1, when the photoreceptor forming material evaporates, the amount of heat absorbed near the glass transition temperature IJj (Tg) and the crystallization temperature (
The calorific value near Te) varies depending on the evaporation material, shape, heating rate, etc., and melting @ll(Tm ) where M evolution begins steadily.
The time it takes for the evaporated material to reach this point is K. For this reason.

In the selenium-tellurium solution, fractional distillation occurs due to the large difference in vapor pressure between tellurium and selenium.
A one-degree distribution will occur.

In order to reduce the variation in the initial evaporation time until the steady evaporation starts, the temperature is set at ＠ij between the crystallization temperature (Te) and the melting temperature (Tm), where the vapor pressure is small.
Maintaining (To≦T≦Tm) for a certain period of time and adjusting the filtering heat balance due to heat absorption and heat generation to the point where it can be practically ignored is the key to preventing the constant speed change from M, and the resulting sensitivity and T variation of the photoreceptor. They discovered that this is effective in suppressing the

When a selenium-tellurium/selenium/aluminum photoreceptor is manufactured by the method of the present invention, a photoreceptor layer of 40 to 60 m thick of selenium is generally used.

A top layer of selenium containing 6 to 15 thick layers with a thickness of 2 to 15 # is laminated. To attach this photoreceptor layer, maintain the aluminum t of the conductive substrate at 60 to 75°C.
Selenium and a selenium-tellurium alloy, which is the evaporation source, are placed in the evaporation board, placed in the evaporation IIF equipment, and placed at port t-32.
Maintained at 0 to 340°C, and inside vacuum evaporation equipment t1 x 1
It is preferable to maintain a vacuum degree of 0-' to 5 X 10-' Torr, and in this case, the deposition of the selenium-tellurium alloy layer depends on the threshold of its crystallization temperature (Te) and melting attitude (Tm). It is generally preferred to maintain the temperature at a constant temperature of 2 to 5 minutes.

The present invention is not limited to the vapor deposition of selenium-tellurium alloys, but rather the vapor deposition process of alloys consisting of components with a large difference between the two vapors. It is applicable to

It is possible to obtain a photoreceptor with significantly less variation in photosensitivity than with a trap.

An embodiment of the present invention will be described below, but the present invention is not limited to this embodiment.

Example 1 20φ aluminum (=super finishing on the surface of the ram base drum)
Next, perform ultrasonic cleaning with trichlorethylene, rinse with water, and wipe with alcohol.

The mixture was heat-treated at 80-150°C for 30-120 minutes, cooled, and then placed in a leather cabinet. As vapor deposition sources, two boards are installed in the vapor deposition equipment, and Sele 71000 is installed on board 41.
g, and put tot* tellurium [containing selenium 5IsIt-] on the second board.

The base temperature of the aluminum substrate is maintained at 70°C.

I X 10-'Torr's true g! Selenium was vacuum deposited on the first board for 28 minutes at a temperature of 28 ffck.

The film was deposited on a selenium first photoreceptor 4t--aluminum base--with a film thickness of 50 srn. Next, the second board was kept at 11°C in the dark for 3 minutes, and then further heated and kept at 320°C for 6 minutes.
Vacuum deposition was performed for minutes.

In this case, the crystallization temperature (Te
) is 165℃, melting@1f, (Tm) is 228℃
Met.

In this way, a selenium-tellurium second photoreceptor layer having a thickness of 5 μm was deposited. The particle size is 1 to 2φ.

In the same manner, a photoreceptor layer having a grain size of 2 to 4 φ was deposited. At this time, keep the temperature of the second board t-, 185°C for 3 minutes, further raise the temperature to 320°C, and deposit for 6 minutes. Created friend.

9th to compare with the above method of book @ Ming, 2nd board 1 grain M
The photoreceptor layer was deposited by simply maintaining the photoreceptor layer at 320 DEG C. for 6 minutes in the case of kl~2φ and for 6 minutes at F1320 DEG C. in the case of 1 mm diameter 2 to 4φ.

V was measured. The results are shown in the table below, Feeling If: 8w
(seconds) fl, give a surface charging potential of 100OV,
Irradiated with light of 20 lux, this charged potential was 1oovt.
The time required for the decay to occur is expressed as 't'.

Table () shows the standard deviation. From this table, it can be seen that the crystallization temperature f('r
The photoreceptor manufactured by the vapor deposition method of the present invention, which is kept at a temperature between e) and the melting temperature (Tm) for a certain period of time, is an excellent product with extremely low sensitivity sensitivity that is ignored in practical terms. I understand that there is something.

[Brief explanation of the drawing]

The figure is a schematic diagram of differential thermal analysis data showing the thermophysical properties of the evaporated material when the temperature is increased. Applicant's agent Kiyoshi Ino

Claims (1)

[Claims] In the production of an electrophotographic photoreceptor by vacuum deposition. A vapor deposition method characterized by maintaining the temperature of the evaporated substance (tLt) at a temperature above the crystallization temperature of the vaporized substance and below the melting temperature for a certain period of time at the initial stage of vapor deposition.