JPH01204055A - Manufacture of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance surface strength and to prevent external damage by decomposing a mixture of 2 kinds of specified gases by glow discharge and forming a surface layer composed essentially of amorphous silicon carbide on an amorphous silicon photoconductive layer. CONSTITUTION:The amorphous silicon type photoconductive layer is formed on a cylindrical aluminum substrate by introducing a gaseous mixture of silane, diborane, and hydrogen into a reactor and decomposing them by glow discharge. The surface layer composed essentially of amorphous silicon carbide is formed by introducing a gaseous mixture of fluorohydrocarbon and silicon hydride as starting gases after the reactor has been evacuated, and decomposing them by glow discharge. This surface layer has high surface hardness and resistance to external damage and prevents unsharpness of images. As said fluorohydro carbon, at least one is selected from the formulae shown on the right in which n is an integer, and X is 1-2n+2, Y is 1-2n, and Z is 1-2n-2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing an electrophotographic photoreceptor, and in particular, to a method for manufacturing an electrophotographic photoreceptor, in particular, a method for manufacturing an amorphous silicon-based photoconductive layer and an amorphous silicon carbide-based surface layer. The present invention relates to a method of manufacturing an electrophotographic photoreceptor having the following.

2. Description of the Related Art In recent years, electrophotographic photoreceptors using amorphous silicon as a photosensitive layer have been developed, and various improvements have been attempted. This photoreceptor using amorphous silicon is
When an amorphous film of silicon is formed on a conductive substrate by glow discharge decomposition of silane (SiH4) gas, hydrogen atoms are inevitably incorporated into the amorphous silicon film, resulting in photoconductivity. It is intended to be presented. Amorphous silicon photoreceptors have high photosensitivity to light with a wavelength of about 400 nm to 700 nm, high heat resistance, and excellent mechanical strength. It has been proposed to provide a surface layer having a composition such as SiO. Electrophotographic photoreceptors having such surface layers have a problem in that image blurring occurs when they become wet or are repeatedly used for a long period of time under high temperature and high humidity conditions. In order to improve this point, it has been proposed to provide a surface layer mainly composed of amorphous silicon carbide. (For example, JP-A-57-115551, JP-A No. 57-115556, JP-A No. 58-88753) Problems to be Solved by the Invention By the way, the conventional surface layer mainly composed of amorphous silicon carbide usually The surface layer formed by this method has a Vickers hardness of approximately 30.
The hardness was only about 0 to 400 or less, which was not sufficient in terms of hardness. However, there is a drawback in that the surface condition changes due to friction with a blade for residual toner in the electrophotographic process, a paper peeling claw, etc., and image defects such as white streaks occur in the obtained image.

The present invention has been made in view of the above-mentioned problems in the conventional technology.

Therefore, an object of the present invention is to provide an amorphous silicon-based electrophotographic photoreceptor having a surface layer having high hardness and excellent wear resistance.

Means and Effects for Solving the Problems The present invention provides an electrophotographic photoreceptor in which an amorphous silicon-based photoconductive layer and an amorphous silicon carbide-based surface layer are sequentially formed on a conductive substrate by a glow discharge decomposition method. In the manufacturing method, after forming an amorphous silicon-based photoconductive layer, a gas mixture consisting of a fluorohydrocarbon gas and a silicon hydride gas is introduced into a reaction chamber as a raw material gas, and the amorphous silicon is decomposed by glow discharge decomposition. It is characterized by forming a surface layer mainly composed of silicon carbide.

The present invention will be described in detail below.

The conductive substrate used in the present invention includes alloys such as aluminum, nickel, chromium, and stainless steel;
Examples include a plastic sheet or glass with a conductive film, and paper treated to make it conductive.

The amorphous silicon-based photoconductive layer is formed on the above conductive substrate by glow discharge decomposition using a silicon compound as a reactive gas. In other words, plus? CV D (Ch
chemical vapor [)eposition)
A reactive gas mainly composed of silicon compounds is introduced into the reaction chamber of the device, and by glow discharge decomposition of this reactive gas, an amorphous silicon-based photoconductive conductor is formed on a conductive substrate set at a predetermined position in the reaction chamber. Form a layer.

The silicon compound used in the present invention includes 5f
H4, S! 2 H6,5IC14,5iHC! 3.5f
H2CI2, Sf (CH3>4, S!3 HB
, S! 4 Hlo etc. can be mentioned.

It is also possible to use a mixture of various carrier gases such as hydrogen, helium, argon, neon, etc. together with the silicon compound as required. Furthermore, it is also possible to improve the electrophotographic properties of the amorphous silicon-based photosensitive layer by mixing diborane gas, phosphine gas, or other donor gas into the above gas.

Conditions for glow discharge decomposition for forming an amorphous silicon photosensitive layer using the above gas are as follows, taking the case of AC discharge as an example.

Power frequency is usually 0.1-30M)12. Preferably 5~
20 liters, and the pressure inside the reaction chamber during discharge is 0.1~
5 Torr, and the substrate heating temperature is ioo to 400°C.

The film thickness of the photoconductive layer in the present invention can be set arbitrarily, but 11I! 11~2001I! 11, especially 10ttm
~100- is suitable.

In the present invention, in the electrophotographic photoreceptor, a photoconductive layer that generates charge carriers in response to light irradiation is formed on a conductive substrate. A transport layer and/or a charge blocking layer forming a barrier to the charge carriers may be deposited.

Next, a surface layer mainly composed of amorphous silicon carbide is formed on the amorphous silicon-based photosensitive layer.

As the raw material gas for forming the surface layer, a gas mixture consisting of a fluorohydrocarbon gas and a silicon hydride gas is used. The mixing ratio of these can be set as appropriate, but for example, the ratio of the former and the latter is 20% in flow m ratio.
It is preferable to use it in the range of :1 to 1:2o.

As the fluorohydrocarbon, the following general formula (A) ([3)
and (C) are used, and CnH2n+2
−xFx (A)c, H2,−,F,
CB)Cto1'F
(C)n 2n-2-z z (where 0 represents an integer, X represents an integer from 1 to 2n+2, y represents an integer from 1 to 2n, and 2 represents 1
(representing an integer from 2n-2 to 2n-2) Specifically, for example,
CH3F (fluoromethane), CH2F2 (difluoromethane), CHF3 (fluoroform), CF4
(tetrafluoromethane), C2 [-15F (fluoroethane), C2H4F2 (difluoroethane), c2
F6 (perfluoroethane), C2H3F (fluoroethylene), C3H3F (allyl fluoride), c3F4
(tetraflureo-alene), etc.

In addition, as silicon hydride, S i H4, S l 2
H6, S 13 HB, S! 4 Hlo etc. can be mentioned.

The raw materials for forming the surface layer listed above may be gaseous, solid, or liquid at room temperature, but if they are required to be in solid or liquid form, they are vaporized into the reaction chamber. to be introduced.

The surface layer is formed by glow discharge decomposition of the above raw material gas using a plasma CVD apparatus, but glow discharge decomposition can be performed using either direct current or alternating current discharge. Taking the case of AC discharge as an example, the conditions for film formation are that the frequency is 0.1 to 30 MHz, preferably 5 to 20 MHz, and the degree of vacuum during discharge is 0.1.
~5 Torr (13,3~687 Pa), and the substrate heating temperature is 100~400°C.

The thickness of the surface layer can be set arbitrarily, but is preferably between 0 and 1G, preferably between 0.2 and 5 μm.

In the present invention, since a mixed gas of silicon hydride and fluorohydrocarbon is used to form the amorphous silicon carbide surface layer, hydrogen atoms generated by glow discharge decomposition combine with fluorine atoms to form fluorocarbons. It becomes hydrogen chloride and is removed from the system. Therefore, it is presumed that the amount of hydrogen gas introduced into the formed surface layer is significantly reduced, and the hardness of the formed surface layer is increased.

EXAMPLES Next, the method for manufacturing the electrophotographic photoreceptor of the present invention will be explained with reference to examples.

Example 1 A cylindrical aluminum substrate was placed at a predetermined position in a capacitively coupled plasma CVD apparatus capable of forming an amorphous silicon film on a cylindrical substrate, and silane (S i H4
) gas, diborane (82H6) gas, and hydrogen (H2) gas and performs glow discharge decomposition to form a temporary amorphous silicon charge injection prevention layer with a thickness of 2 on the cylindrical aluminum substrate. An amorphous silicon-based photoconductive layer with a thickness of 20 μm was produced.

The conditions for forming the charge injection prevention layer at this time were as follows.

100% silane gas flow m: 200ci/min3
00ppm hydrogen diluted diborane gas flowffl: 20
0 cffl/min Reactor internal pressure: 0.8 Torr Discharge power: 180 W Discharge time: 40 m1n Discharge frequency: 13.56 aflz Substrate temperature: 250° C. The conditions for forming the photoconductive layer were as follows.

100% silane gas flowffi: 200cffl/
min100ppm hydrogen diluted diborane gas flow 1:5
cIA/min Hydrogen gas flow 17J: 195oyf
/min Reactor internal pressure: 0.8 Torr Discharge power: iaow Discharge time: 400 m1n Discharge frequency: 13.56 l Substrate temperature = 250°C Subsequently, a surface layer was applied on the formed amorphous silicon-based photoconductive layer. was formed. That is, after evacuating the reaction chamber,
A mixed gas consisting of carbon tetrafluoride (CF4) and silane gas (Si4) was introduced into the reaction chamber and decomposed by glow discharge to form a surface layer with a thickness of 0.5P.

The conditions for forming the surface layer at this time were as follows.

Carbon tetrafluoride gas flow 1: 40 CIi/min Silane gas flow rate: 16 CIA/min Reactor internal pressure: 0.5 Torr Discharge power: 200 W Discharge time: 60 m1n Discharge frequency: 13.56 cm2 Substrate temperature: 250°C Manufactured in this way When the Vickers hardness (load=1 (EJ)) of the surface layer of the electrophotographic photoreceptor was measured, it was 780 KI/cri, which was extremely hard.

This electrophotographic photoreceptor was placed in a copying machine, and copies were made using a positive corona charging method, and the image quality of the copied images was evaluated. After copying was repeated 50,000 times, the image quality was evaluated under an environment of a temperature of 35°C and a humidity of 85% RH, and an environment of a temperature of 5°C and a humidity of 15% RH. There were no visible scratches caused by the blade or paper peeling wind.

Example 2 In the same manner as in Example 1, a charge injection prevention layer mainly composed of amorphous silicon with a thickness of about 2 mm and a photoconductive layer with a thickness of about 201 m were produced on a cylindrical aluminum substrate.

Subsequently, perfluoroethane (C2F6
) and silane gas were used in the same manner as in Example 1 to form a surface layer with a thickness of 0.5 μm. The film forming conditions at this time were as follows.

Perfluoroethane flow rate: 40 cffl/min Silane gas flow 1: 24 ci/min Reactor internal pressure: 0.
5Torr Discharge power: 200W Discharge time: 30m1n Discharge frequency = 13゜56M+IZ Substrate temperature: 250°C The Vickers hardness (load = io9) of the surface layer of the electrophotographic photoreceptor thus manufactured was 720KI/c
I needed it with rA. When image quality was evaluated in the same manner as in Example 1, there was no image blurring or decrease in image density, and no scratches caused by the cleaning blade or paper peeling wind were observed.

Comparative Example In the same manner as in Example 1, a charge injection prevention layer mainly composed of amorphous silicon with a thickness of about 2J1m and a photoconductive layer with a thickness of about 20J1m were produced on a cylindrical aluminum substrate.

Subsequently, a film thickness of 0.0.
A 5M surface layer was formed. The film forming conditions at this time were as follows.

Methane gas flow rate: 1007/min Silane gas flow rate: 20 Cffl/min Reactor internal pressure: 0.5T
orr Discharge power: 200 W Discharge time: 30 m1n Discharge frequency: 13.56 min Z Substrate temperature: 250° C. The Vickers hardness (load = iog) of the surface layer of the electrophotographic photoreceptor thus manufactured was 1470 KI/
It was cti.

This electrophotographic photoreceptor was placed in a copying machine, copies were made using a positive corona charging method, and the image quality of the copied images was evaluated. After copying was repeated 1500 times, image defects due to scratches caused by the cleaning blade or paper peeling wind began to be observed on the image.

Effects of the Invention According to the present invention, a surface mainly composed of amorphous silicon carbide is formed on an amorphous silicon photoconductive layer by glow discharge decomposition using a mixed gas of fluorohydrocarbon gas and silicon hydride gas. Since the layer is provided, the formed surface layer has a very high surface hardness of at least 500 Vickers hardness.

Therefore, the electrophotographic photoreceptor of the present invention is less likely to be scratched by cleaning blades, paper separation claws, etc. during use, and can produce copies without blurring of images under any operating conditions. You can get the image.

Patent applicant Fuji Xerox Co., Ltd. Agent
Patent attorney Tsuyoshi Eyebe

Claims (2)

[Claims] (1) In a method for manufacturing an electrophotographic photoreceptor in which an amorphous silicon-based photoconductive layer and an amorphous silicon carbide-based surface layer are sequentially formed on a conductive substrate by a glow discharge decomposition method, After forming the conductive layer, a gas mixture consisting of at least fluorohydrocarbon gas and silicon hydride gas is introduced into the reaction chamber as a raw material gas, and a surface layer mainly composed of amorphous silicon carbide is formed by glow discharge decomposition. 1. A method for producing an electrophotographic photoreceptor, the method comprising: forming an electrophotographic photoreceptor. (2) The electrophotographic photosensitive material according to claim (1), wherein the fluorohydrocarbon is at least one selected from those represented by the following general formulas (A), (B), and (C). How the body is manufactured. C_nH_2_n_+_2_-_xF_x(A) C_nH_2_n_-_yF_y(B) C_nH_2_n_-_2_-_zF_z(C) (In the formula, n represents an integer, x represents an integer from 1 to 2n+2, y represents an integer from 1 to 2n, z is 1
(represents an integer from 2n-2)