JPS60144752A - Production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enable production of a photosensitive body having a uniform density distribution, an increase in electrifying potential and a decrease in the variance thereof by supplying gradually a material for vacuum deposition to an evaporating source and forming instantaneously the film thereof. CONSTITUTION:Powder SeTe is weighed into a powder supply device 14 and an evaporating source 12 is electrically heated after evacuation to form an electric charge transfer layer 21 on a conductive substrate 11. An evaporating source 13 is then electrically heated to >=400 deg.C prescribed temp. and thereafter the function to supply the powder is started to conduct the powder by a guide 15 to the source 13 and to supply continuously by each small amt. to said source so that the supplied powder is nearly instantaneously evaporated without forming a molten pool in the evaporating source, thus forming an electric charge generating layer 22. If the density distribution of the Te compsn. of a photosensitive body 2 obtd. in such a way is analyzed from the surface to the inside of the photosensitive layer, the resultant film is remarkably improved not only on the compsn. deviation of the Te density with respect to the base material but also in the variance among samples.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing an electrophotographic photoreceptor, and more specifically, to an electrophotographic photoreceptor comprising a layer of a material consisting of an alloy or compound of three or more elements. The present invention relates to a method of forming a layer using a vacuum evaporation method.

BACKGROUND OF THE INVENTION Conventionally, in response to the demand for higher sensitivity of electrophotographic photoreceptors, efforts have been made to achieve this goal by incorporating various sensitizers by vapor deposition. However, there is a problem in that the composition of the evaporation source changes over time due to the vapor pressure, atomic weight, etc. of the constituent components, and the composition of the film changes accordingly. This inconvenience causes a significant increase in costs, such as an increase in the defective rate due to increased product variation in photoconductors and the necessity of resetting copying conditions when replacing photoconductors. In addition, there are problems with film formation at the polishing and development stages, and combinations of ingredients that cannot be formed into films using conventional methods often occur, which limits the range of solutions for each material. This was an obstacle to the research goal of developing better products faster.

Purpose of the Invention The purpose of the present invention is to provide a method for manufacturing an electrophotographic photoreceptor using a vapor deposition method that eliminates the above-mentioned disadvantages and enables film formation that meets the design of the photoreceptor with less product variation (and fewer defects). It is about providing.

Structure of the Invention The method for producing an electrophotographic photoreceptor of the present invention is a method for producing an electrophotographic photoreceptor having a layer of a substance made of an alloy or a compound of at least three elements, wherein the temperature is higher than the temperature at which the substance can evaporate. This method is characterized in that the above-mentioned substance is continuously supplied in small amounts to an evaporation source held in advance and is vacuum-deposited onto a substrate to form a film.

The details of the method for manufacturing an electrophotographic photoreceptor of the present invention will be explained with reference to the drawings.

In its simplest form, an electrophotographic photoreceptor consists of two layers: a conductive substrate and a photosensitive layer. In order to provide additional functions and improve performance, a charge injection blocking layer from the substrate, a charge transport layer, a charge generation layer, a charge injection blocking layer from the surface, a surface layer, etc. may be provided separately or simultaneously. The method of the present invention can also be applied to the case of a layer of 2, and the present invention is not limited thereto.

In order to simplify the explanation, an example will be described below in which the method of the present invention was used to deposit a two-element alloy of 5eTe with respect to the most common electrophotographic photoreceptor, 5e-8eTa, a two-layer photoreceptor. do.

The 5c-5eTa bilayer photoformer has a charge transport layer of Se and a 5e
It means a Ta charge generation layer. The purpose of mixing Te into Se is that when Te is mixed into Se, the properties of 5eTe as a semiconductor become narrow (band gear), and when irradiated with light, electrons are easily excited from the filled band to the conductor. In other words, photoreceptors have not only become more sensitive and capable of high-speed copying, but also become sensitive to long-wavelength light, and are also used as photoreceptors for semiconductor laser printers. This 5e-8eTe photoreceptor is manufactured using a vacuum evaporation machine whose main parts are shown in FIG.

In the figure, 1 is a vacuum evaporator, 11 is a conductive substrate, 12 is an evaporation source for charge transport layer deposition, and 13 is an evaporation source for charge generation layer deposition. After weighing and evacuation of Se in the evaporation source 12 and 5eTe in the evaporation source 13, the evaporation source 12 is heated with electricity to form a charge transport layer 21 on the conductive substrate, and then the evaporation source 13 is heated with electricity to form a charge generation layer. FIG. 2 shows an electrophotographic photoreceptor obtained through such a process in which No. 22 is also formed. T of this photoreceptor
FIG. 3 shows the results of analyzing the concentration distribution of the e composition from the surface to the interior of the photosensitive layer for four cases conducted under the same conditions.

As is clear from FIG. 3, the composition deviation with respect to the base material and the concentration variation between samples are significant. Various proposals have been made to improve this compositional deviation, but all of them require complicated compositional control, or require complicated calculations to be performed, such as changing the weighed raw materials for the next deposition, or changing the evaporation source. At present, fundamental solutions such as disposal of leftover raw materials have not been reached.

In the method of the present invention, for example, in a vacuum evaporation apparatus as shown in FIG.
5e to a device 14 having a mechanism for storing and supplying a mixture of
After weighing and evacuation of Te, the lid generator 12 is heated with electricity to form a charge transport layer on the conductive substrate, and then the evaporation source 13 is heated to a predetermined temperature 4.
After applying electrical heating to 00°C or higher, preferably 500'Q or higher, the powder supply function is started, and the powder is guided to the evaporation source by the guide 15, and is continuously supplied little by little until the supplied powder is heated. To form a charge generation layer in such a way that it evaporates almost instantaneously without forming a molten pool in an evaporation source. The concentration distribution of the Te composition of the photoreceptor thus obtained was analyzed from the surface to the inside of the photosensitive layer, and the results were analyzed under the same conditions.
An example is shown in FIG. As shown in FIG. 5, a film can be obtained in which not only the composition deviation of the T@ concentration with respect to the base material but also the variation between samples is significantly improved.

The present invention is not only applicable to the charge generation layer of the previous example (
, can be applied to all constituent elements of an electrophotographic photoreceptor, if necessary.

For example, NiC can be used as a conductive layer on an electrophotographic photoreceptor support.
r, ■ro (indium tin oxide) SO5
It is formed when forming alloys or compounds such as, or for the purpose of blocking charge injection from the substrate.

Compounds such as Sin, 5i()2, MtF, TiO□ can be applied to the layer. Regarding the sensitizing layers described in the examples, all of them are systems in which Se-based materials are doped with Te as a sensitizer (Sbs Bis In, Tz%As%
Two or more types of S%Ct, V, etc.0) Alloys, CdS, CdS
It can also be applied to compounds such as e, PbS, etc. Furthermore, Co-N i -p % Co which forms a magnetic latent image
-F e 30 I Not only magnetic materials such as CrOH, but also electron
Various phosphor layers for the purpose of sensitization, which are disposed on the back side of the line photographic photoreceptor, are also included in the method of the present invention as constituent elements of the electrophotographic photoreceptor.

The manufacturing method of the present invention will be explained below using Examples and Comparative Examples.

Example The apparatus shown in FIG. 4 was equipped with an aluminum substrate 11 treated with aluminum oxide, an evaporation source 12 for depositing a charge transport layer with Se,
After each of the charge generating layer deposition powder supply means 14f contained the 5e-Ta alloy, it was evacuated to a pressure of 10-'torr. Next, the aluminum substrate was heated to 70° C. and the evaporation source for depositing the charge transport layer was heated to deposit Se, thereby forming a charge transport layer of amorphous Se on the aluminum substrate.

At this time, the evaporation rate was 5 μ/-, and the film thickness was 55 μm. After forming the charge transport layer, the evaporation source 13 for charge generation layer deposition is heated to generate charges. 5s-Te alloy is supplied little by little from the powder supply means for layer deposition to this evaporation source 13 to form the charge generation layer. was vapor-deposited. This 5s-Te alloy contains 40% by weight of To and has a grain size of 150 to 350 μm.
The evaporation source 13 is heated to 450°C, and the 5e-Te alloy is supplied so that the evaporation rate is 0.5μ/- to form a charge generation layer with a thickness of 1/Jm. did.

In forming this charge generation layer, the S e -Te alloy supplied from the supply means 14 is instantaneously evaporated on the evaporation source 13 to form a pool of molten 5e-Te alloy in the evaporation source 13 . There was nothing to do.

A total of 10 photoreceptors were manufactured by performing the same operation, and their electrophotographic characteristics were measured.

Comparative Example Using the apparatus shown in Figure 1, 5s-T was applied to 12fSe%13.
The a-alloy was accommodated, and the charge transport layer was formed in the same manner as in the example. In the formation of the charge generation layer, the S e-Te alloy is
A pellet-shaped 5e-Te alloy with an outer diameter of 6 cm and a thickness of 2 m containing 40% by weight of was vapor-deposited.

A total of 10 photoreceptors were manufactured by performing the same operations as in the examples, and their electrophotographic characteristics were measured.

The measurement results of electrophotographic characteristics of Examples and Comparative Examples are shown in FIG. As is clear from FIG. 6, the photoreceptor according to the method of the present invention has an average charging potential of 900 V and σ of 30 V.
It was V. On the other hand, in the photoreceptor according to the method t of the comparative example, the charging potential was 750 V on average, and σ was 145 V. In other words, it has been revealed that the photoreceptor according to the present invention has a high charging potential (and its variation can be reduced). When the Te concentration in the film thickness direction from the surface of the photoreceptor was measured, it was shown in Fig. 5 in the present invention, and in the comparative example. As shown in FIG. 3, the photoreceptor according to the present invention exhibits a uniform density in the film thickness direction, but the photoreceptor according to the comparative example has a thicker concentration on the surface side and the transport layer side, and There is also large variation between each photoreceptor.

Effects of the Invention The method for manufacturing an electrophotographic photoreceptor of the present invention is such that a substance to be vacuum-deposited is gradually supplied to an evaporation source to form a film instantly, and a photoreceptor with a uniform concentration distribution can be manufactured. As a result, it is possible to manufacture a photoreceptor with a high charging potential and a small variation in charging potential.

[Brief explanation of drawings]

Figure 1 is a schematic front view of a conventional vacuum evaporation apparatus, Figure 2 is a cross-sectional view of a two-layer electrophotographic photoreceptor, and Figure 3 is the Te concentration distribution of a two-layer electrophotographic photoreceptor formed by a conventional method. FIG. 4 is a schematic front view of an example of a vacuum evaporation apparatus used to carry out the manufacturing method of the present invention, and FIG. FIG. 6 is a graph showing the degree distribution, and is a diagram showing variations in the charging potential of two-layer photoreceptors formed by the method of the present invention and the conventional method. Symbols in the figure: l...Vacuum deposition device: 11...Conductive substrate: 12;
...Evaporation source for charge transport: 13...Evaporation source for charge generation layer: 14...Supply powder container; 15...Powder guide; 2...Electrophotographic photoreceptor: 21... -Charge transport layer; 2
2... Charge generation layer. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a method for manufacturing an electrophotographic photoreceptor having a layer of a substance made of an alloy or a compound of three or more elements, a small amount of the substance is placed in an evaporation source that has been maintained in advance at a temperature higher than the temperature at which the substance can evaporate. A method for manufacturing an electrophotographic photoreceptor, characterized in that a film is formed on a substrate by vacuum evaporation.