JP2002139856A - Electrophotographic photoreceptor, electrophotographic device and method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrophotographic photoreceptor realizing the restraint of the fusion of toner, having a high toner recovering rate, restrained from being unevenly ground by a cleaning blade, made excellent intoner transfer efficiency and capable of forming a uniform image. SOLUTION: The surface layer of an a-C system is formed under a film deposition condition (area 1) that the deposition rate of the surface layer is increased with pressure buildup in a reaction container.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor having sensitivity to light such as ultraviolet rays, visible rays, infrared rays, X-rays and .gamma.-rays. The present invention relates to an electrophotographic photoreceptor in which an amorphous carbon-based (hereinafter also referred to as aC-based) surface layer is formed on a photoconductive layer of Si-based.

[0002]

2. Description of the Related Art Materials used for a photoconductive layer of an electrophotographic photosensitive member include selenium, cadmium sulfide, zinc oxide, and the like.
Materials such as phthalocyanine and a-Si-based materials can be mentioned. Among them, hydrogenated a-Si (hereinafter, a-Si: H
A-Si) and halogenated a-Si (hereinafter a-Si:
X) is higher in surface hardness than a photoconductive layer made of another material, and has high sensitivity to long-wavelength light (770 nm to 800 nm) generated from a semiconductor laser or the like. Has good durability and photoelectric properties. Furthermore, these photoconductive layers have high sensitivity, high S / N ratio, good absorption spectrum characteristics, fast photoresponse,
A desired dark resistance value can be realized, and it has desirable characteristics such as being harmless to the human body.For these reasons, an electrophotographic photosensitive member having an a-Si-based photoconductive layer is
It is being widely used in electrophotographic apparatuses, such as high-speed copiers and laser printers (hereinafter, also referred to as LBPs), which require high durability and photoelectric properties.

[0003] a-Si: H and a-Si: X are obtained by a sputtering method or a method of decomposing a source gas by heat (thermal CVD).
Method), a method of decomposing a source gas by light (photo CVD)
Method), a method of decomposing a source gas by plasma (plasma CVD method), and the like.
The photoconductive layer of the electrophotographic photoreceptor is manufactured by a plasma CVD method because dense deposition is possible. That is, the raw material gas is decomposed by glow discharge or the like by direct current or high frequency (RF, VHF), microwave, or the like,
Glass, quartz, heat-resistant synthetic resin film, stainless steel,
A-Si: H and a-Si on a conductive substrate such as aluminum
Deposit Si: X to form a photoconductive layer.

[0004] However, a-Si: H and a-S
The surface of the photoconductive layer made of i: X is easily deteriorated by environmental humidity and chemical species generated by corona discharge. Therefore, when an electrophotographic photosensitive member having these photoconductive layers is used, Although a good image was obtained in the early stage, an image defect sometimes occurred after a relatively short period of use.

[0005] In order to solve this problem, it has been proposed to form an amorphous silicon carbide (hereinafter a-SiC) surface layer on the photoconductive layer to protect the photoconductive layer. . For example, in JP-A-57-115551, a silicon atom and a carbon atom are used as a base,
Non-photoconductive amorphous material containing hydrogen atom,
It has been disclosed to form a surface barrier layer. Japanese Patent Application Laid-Open No. 57-115559 discloses that a surface barrier layer composed of a non-photoconductive amorphous material containing a silicon atom and a carbon atom as a base and containing a halogen atom is disclosed. However, despite the provision of these surface layers, the durability of the electrophotographic photoreceptor was sometimes insufficient.

In order to solve the above-mentioned problems, it has been proposed to form an aC-based surface layer as a surface layer having a further excellent protective effect. For example, hydrogenated amorphous carbon containing 10 to 40 atm% hydrogen atoms (hereinafter a-
The formation of a surface layer by C: H was disclosed in JP-A-61-219961. Further, Japanese Patent Application Laid-Open No. Hei 6-317920 discloses that a frequency of 20 MHz to 4 MHz is used.
It has been disclosed that a surface layer is formed from a non-single-crystal carbon-based material having carbon atoms as a base by a plasma CVD method in which a source gas is decomposed by a glow discharge generated by an electromagnetic wave of 50 MHz. Further, Japanese Patent Application Laid-Open No. 8-158050 discloses that a DLC film (diamond-like carbon film) having high hardness is provided as a surface layer by using an ECR plasma method.

[0007]

However, the required performance of an electrophotographic apparatus is continually becoming more sophisticated, and a-C
With respect to the electrophotographic photoreceptor having the system surface layer formed thereon, further improvements in the performance described below have been desired.

First, for the following reasons, toner fusion on the surface of the electrophotographic photosensitive member, that is, toner is prevented from melting and adhering and depositing on the surface of the electrophotographic photosensitive member during long-term use, It has been required to achieve good toner recovery.

In an electrophotographic apparatus, an electric latent image is formed on an electrophotographic photosensitive member by means such as charging, static elimination, exposure, and the like, and then this electric latent image is developed with toner, and a toner image is formed on a transfer material. After the transfer, the toner image is fixed by heat, pressure, solvent vapor or the like. Further, untransferred toner remaining on the electrophotographic photosensitive member is recovered by cleaning.

The weight average particle diameter of the toner used for the above-mentioned development has conventionally been about 10 to 12 μm. However, in recent years, the demand for more vivid and precise images has been increasing. The size reduction of toner particles has been promoted. However, as compared with the conventional toner having a particle size, the toner having a small particle size is more difficult to be removed from the surface of the electrophotographic photosensitive member by cleaning, and thus may sometimes remain on the surface of the electrophotographic photosensitive member. For this reason, a toner having a small particle diameter tends to cause a problem of fusing, and the recovery efficiency is sometimes low.

Further, the fixing efficiency of a toner image on a transfer material can be improved by using a toner having a low melting point, and a toner having a lower melting point is being used in order to cope with a recent increase in printing speed. . Further, with the spread of full-color electrophotographic apparatuses, color toners are being used for general purposes. However, color toners have a lower melting point than conventional black-and-white toners. In addition, the conventional image fixing device has a built-in heater, and the fixing roller is kept at a temperature of 150 ° C. to 200 ° C., and the toner is fixed on the transfer material by melting the toner. In order to reduce the power consumption of the image forming apparatus, it has been studied to lower the temperature of the fixing roller by using a low melting point toner. For the above reasons, the use of low-melting toner is becoming the mainstream in electrophotographic devices, but the low-melting toner softens at low temperatures, so it easily fuses to the surface of the electrophotographic photosensitive member and is recovered by cleaning. In some cases, the efficiency was low.

When the toner is fused to the surface of the electrophotographic photoreceptor, image defects and fusing marks in a solid white image and a halftone image may occur. It is necessary to go out and perform maintenance first, which increases costs. In addition, since the maintenance is performed by removing the electrophotographic photosensitive member from the main body of the electrophotographic apparatus, there is a danger that dent scratches may be made on the electrophotographic photosensitive member during the operation, and the electrophotographic photosensitive member may become unusable.

Such artificial scratches on the surface of the electrophotographic photosensitive member can be suppressed by, for example, increasing the hardness of the surface layer or increasing the thickness of the surface layer itself. However, from the balance between the other properties of the surface layer and the balance between the band gap of the surface layer and the sensitivity of the electrophotographic photosensitive member,
There were restrictions on the hardness and thickness of the surface layer.

Secondly, there has been a demand for suppressing the uneven wear of the surface of the electrophotographic photosensitive member by the blade when cleaning, that is, removing the toner from the surface of the electrophotographic photosensitive member.

The cleaning is usually performed using a blade and a mag roller (cleaning roller using a magnetic brush) in combination. However, as described above, in order to efficiently remove and recover toner having a small particle diameter and low melting point, and to reduce the fusion of the toner, the hardness of the blade is increased or the pressing pressure of the blade is reduced. When the height is increased, in the case of an electrophotographic photoreceptor having a high hardness surface layer such as an a-Si system, the surface layer is not polished smoothly, and uneven unevenness is generated in a streak shape,
In some cases, image quality was impaired. Such a phenomenon is
This is particularly noticeable when the blade has a high hardness and a high pressing pressure.Therefore, it is possible to increase the hardness and the pressing pressure of the blade to values necessary for suppressing fusion of the toner and achieving a high recovery rate. It was often difficult.

Third, with the widespread use of full-color electrophotographic apparatuses, there has been a demand for more excellent toner transfer efficiency and image quality with more excellent uniformity.

In a full-color electrophotographic apparatus, the gradation and the reproducibility of an image having a high density are good, but the gradation is insufficient for the reproducibility of a light color such as human skin or a blue sky. In some cases, the image was rough. The factor that determines the gradation of a full-color electrophotographic apparatus is closely related not only to the number of bits for determining the density of the three primary colors, but also to the transfer efficiency of the toner, which is a characteristic of the electrophotographic photosensitive member. That is, when a light color is reproduced, since the amount of toner adhering to the electrophotographic photosensitive member is small, the amount of toner transferred to the transfer material slightly changes, and the density largely changes. However, in terms of image quality, it appears as roughness of density.
For this reason, in order to develop a full-color electrophotographic apparatus capable of generating a high-quality image in which image roughness is suppressed, development of an electrophotographic photosensitive member having excellent toner transfer efficiency has been required.

In view of the circumstances described above, fusion of the toner is suppressed, the recovery rate of the toner is high, uneven polishing by the cleaning blade is suppressed, and the transfer efficiency of the toner is high and uniform. An electrophotographic photoreceptor having an aC-based surface layer capable of forming an image formed on an a-Si-based photoconductive layer, an electrophotographic apparatus provided with such an electrophotographic photoreceptor, and It is an object of the present invention to provide a method for producing such an electrophotographic photoreceptor.

[0019]

According to the present invention, there is provided an amorphous silicon-based photoconductive layer formed on a conductive substrate, and an amorphous carbon layer formed on the photoconductive layer. And a system surface layer, wherein the surface layer is formed by a plasma CVD method under conditions in which the deposition rate of the surface layer increases as the pressure in the reaction vessel increases. An electrophotographic photosensitive member is provided.

Further, according to the present invention, at least the amorphous silicon-based photoconductive layer formed on the conductive substrate and the amorphous carbon-based surface layer formed on the photoconductive layer are included. A method of manufacturing an electrophotographic photoreceptor, comprising: a step of forming the photoconductive layer by a plasma CVD method; and a step of forming a photoconductive layer by a plasma CVD method under a condition in which a deposition rate of the surface layer increases with an increase in pressure in a reaction vessel. Forming a surface layer of the electrophotographic photoreceptor.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

The present inventors have conducted intensive studies on the relationship between the manufacturing conditions of the aC-based surface layer and the characteristics of the obtained surface layer.
By producing the surface layer under a manufacturing condition that satisfies the relationship that the pressure in the reaction vessel, that is, the deposition rate of the surface layer increases as the pressure in the discharge space increases, fusion of toner is suppressed, and toner The present inventors have found that an aC-based surface layer which has a high recovery rate, suppresses uneven polishing by a cleaning blade, has a high toner transfer efficiency, and can form a uniform image can be obtained.

The reason why the above characteristics can be realized by forming an aC-based surface layer under the above manufacturing conditions is unknown, but can be guessed as follows.

When an aC-based film is formed by plasma CVD, active species (ions and radicals) decomposed by plasma are adsorbed and bonded to the underlying surface and deposited. Then, a-C fabricated under the conventional manufacturing conditions
The present inventors have found that when the system film is observed with an atomic force microscope (AFM), there are many fine irregularities having a diameter of several tens to several hundreds of nanometers.

On the other hand, when an aC-based film is formed under the film-forming conditions disclosed in the present invention, that is, under such a condition that the deposition rate of the surface layer increases as the pressure in the discharge space increases, the conventional aC-based film is formed. It was confirmed that the occurrence of minute unevenness existing in the film was suppressed and a film surface having excellent smoothness was formed.

Since the fine irregularities on the surface have an anchoring effect on the toner, the toner easily adheres to the irregularities. Then, it is considered that the toner adhered to the irregularities serves as a fusion source, and the adhered lump of the toner grows with the toner as a nucleus, and the fusion proceeds. However, since the surface layer according to the present invention has almost no irregularities that can serve as a fusion source of the toner, the fusion of the toner is significantly suppressed, and at the same time, the releasability of the toner is improved, and a high recovery rate is obtained. It is considered possible.

Further, in the surface layer formed by the manufacturing method of the present invention, not only the occurrence of irregularities on the surface is suppressed but also the inside of the surface layer is dense. For this reason,
It is considered that the surface layer in the present invention is uniformly polished by the cleaning blade. Further, since the surface layer has almost no irregularities, the surface free energy of the surface layer is low and the water repellency is high, so that excellent toner transfer efficiency can be realized and uniform image formation can be achieved. It is considered to be.

The production conditions of the present invention will be described in more detail. In the formation of the aC-based surface layer, film forming parameters such as the pressure in the reaction vessel, the temperature of the conductive substrate, the high-frequency applied power for plasma generation, the frequency, the gas type, and the gas flow rate are set to predetermined values. This makes it possible to realize a condition in which the deposition rate of the surface layer increases as the pressure in the reaction vessel increases. That is, with other deposition parameters being constant,
When the pressure in the reaction vessel is changed, the deposition rate of the surface layer can be changed as shown in FIG. In region 2 of FIG. 1, the deposition rate of the surface layer hardly changes even if the pressure in the reaction vessel is changed. On the other hand, in region 1, the deposition rate increases as the pressure in the reaction vessel increases. The surface layer in the present invention is formed under the film forming conditions corresponding to the region 1.

The upper and lower limits of the pressure in the reaction vessel are not particularly limited as long as the film formation conditions corresponding to region 1 in FIG. 1 can be realized. 56 MHz), it is generally not less than 13.3 Pa and not more than 1333 Pa.
In the case of electric power (typically 50 MHz to 450 MHz), the electric power is generally 13.3 mPa to 13.3 Pa. In the present invention, the pressure in the reaction vessel is preferably 665 Pa or less, more preferably 133 Pa or less, and 66.5 from the viewpoint of the balance of the properties of the obtained surface layer.
Pa or less is more preferable. The lower limit of the pressure in the reaction vessel is preferably equal to or higher than the pressure at which the plasma is stably generated.

The upper and lower limits of the temperature of the conductive substrate are not particularly limited as long as the film forming conditions corresponding to region 1 in FIG. 1 can be realized, but from the viewpoint of the balance of the properties of the obtained surface layer. The temperature of the conductive substrate is preferably 50 ° C. or higher, more preferably 80 ° C. or higher, still more preferably 100 ° C. or higher, preferably 400 ° C. or lower, more preferably 380 ° C. or lower, and even more preferably 350 ° C. or lower.

There is no particular limitation on the upper and lower limits of the high frequency applied power for plasma generation as long as the film formation conditions corresponding to region 1 in FIG. 1 can be realized. From the viewpoint, 5 W / ml or more for hydrocarbon raw material gas, and 10 W / ml for higher power
In some cases, the power may be set to 15 W / ml or more, and the upper limit must be suppressed to such a level that abnormal discharge does not occur.

The upper and lower limits of the frequency of the high frequency applied power for plasma generation are not particularly limited as long as the film formation conditions corresponding to region 1 in FIG. 1 can be realized. From the viewpoint of balance, when the RF band is used, 1 MHz or more and 20 MHz or less, preferably 13.56 MHz is used. When the VHF band is used, the frequency may be 50 MHz or more, at a higher frequency it may be 60 MHz or more, or even 80 MHz or more.
Hz or lower, 200 MHz or lower for lower frequencies, and even 150 MHz or lower.

The upper and lower limits of the deposition rate of the surface layer are not particularly limited as long as the film formation conditions corresponding to region 1 in FIG. 1 can be realized. In light of the above, 0.01 nm / sec or more is preferable, 0.05 nm / sec or more is more preferable, 0.1 nm / sec or more is still more preferable, and 2 nm / sec or more.
sec or less, preferably 1 nm / sec or less, more preferably 0.5 nm / sec or less.

The ratio (ΔD) of the change in the deposition rate of the surface layer (ΔDr) to the change in pressure (ΔPress) in the reaction vessel.
r / ΔPress), the upper and lower limits are shown in region 1 in FIG.
There is no particular limitation as long as the film formation conditions corresponding to the above can be realized, but from the viewpoint of the balance of the properties of the obtained surface layer, it is preferably at least 7.5 × 10 ⁻⁵ nm / sec · Pa, × 10 ^-4 nm / sec · Pa or more is more preferable, 3.7 × 10 ^-4 nm / sec · Pa or more is more preferable, and 7.5 × 10 ^-3 nm / sec · Pa or less is preferable, and 6 × 10 ^-4 nm / sec · Pa or less is preferable. ^-3 nm / sec · Pa or less is more preferable, and 3.7 × 10 ^-3 nm / sec · Pa or less is still more preferable.

By optimizing the film forming conditions described above and forming the surface layer under the optimum film forming conditions, unlike the surface layer manufactured under the conventional film forming conditions, the surface has a diameter of several tens to several It is also possible to produce a surface layer having almost no minute irregularities of 100 nanometers. For example, when the surface of the obtained surface layer is observed with an AFM,
The average number of irregularities having a diameter of 100 nm or more in a region of 0 μm can be 10 or less. Note that the diameter of the unevenness refers to the diameter of a circle circumscribing the region where the unevenness exists.

FIG. 2 schematically shows a cross section of an example of the electrophotographic photosensitive member of the present invention. Reference numeral 210 denotes a conductive substrate having a shape such as a cylinder or a sheet, and can be made of a metal such as aluminum and stainless steel, or a glass and a resin subjected to a conductive treatment.

Reference numeral 220 denotes a photoconductive layer made of an a-Si-based material. a-Si based materials are a-Si: H, a-
Si: X, hydrogenated a-Si (hereinafter a-S)
i: H, X), and specific examples thereof include a-Si: H, a-Si: F, a-Si: Cl, a
-Si: Br, a-Si: I, a-Si: H, F, a-
Si: H, Cl, a-Si: H, Br, a-Si: H,
I and the like. If necessary, these a-Si-based materials may be doped with a Group 13 or Group 15 element. From the viewpoint of the balance of the properties of the photoconductive layer, the ratio of hydrogen or halogen to the entire surface layer (when both hydrogen and halogen are present,
The total ratio) is preferably 10 atm% or more and 40 atm% or less. Further, from the viewpoint of the balance of the characteristics of the entire electrophotographic photosensitive member, the thickness of the photoconductive layer is preferably 1 μm or more,
5 μm or more is more preferable, 100 μm or less is preferable, and 50 μm or less is more preferable.

Reference numeral 230 denotes a surface layer made of an aC-based material. The aC-based materials are aC: H, aC: X,
It means hydrogenated halogenated aC (hereinafter also referred to as aC: H, X) and the like, and specific examples thereof include aC: H,
aC: F, aC: Cl, aC: Br, aC:
I, aC: H, F, aC: H, Cl, aC: H,
Br, aC: H, I and the like. Also,
If necessary, these aC-based materials may be doped with a Group 13 or Group 15 element. From the viewpoint of the balance of the properties of the surface layer, the ratio of hydrogen or halogen to the entire surface layer (the total ratio when both hydrogen and halogen are present) is 40 atm% or more and 60 atm% or more.
atm% or less is preferable. In addition, from the viewpoint of the balance of the characteristics of the entire electrophotographic photosensitive member, the thickness of the surface layer is preferably 5 nm or more, more preferably 10 nm or more, and 1000 n
m or less, and more preferably 500 nm or less.

In the electrophotographic photosensitive member of the present invention, the photoconductive member
Reduce material heterogeneity between the electrical layer 220 and the surface layer 230
In order to improve the adhesion, the photoconductive layer 22
0 and the surface layer 230, a buffer layer 260 is formed.
May be The buffer layer 260 is made of, for example,
Fac silicon carbide (a-Si_1-XC_X, 0 <X <1)
Material, specifically, a-Si_1-XC_X: H, a-Si
_1-XC_X: X, a-Si_{1- X}C_X: H, X; amorphous nitrogen
Silicon (a-Si)_1-YN_Y, 0 <Y <4/3) type material
Material, specifically, a-Si_1-YN_Y: H, a-Si
_1-YN_Y: X, a-Si_{1- Y}N_Y: H, X; amorphous acid
Silicon (a-Si)_1-ZO_Z, 0 <Z <2) based materials,
Specifically, a-Si_1-ZO_Z: H, a-Si_1-ZO_Z:
X, a-Si_1-ZO_Z: Can be formed from H, X, etc.
You. If necessary, these materials may be added to the group 13 or 1
Group 5 elements may be doped. Note that the buffer
The thickness of the layer 260 depends on the spectral sensitivity, residual potential, and electrical consistency.
From the viewpoint of, for example, 10 nm or more and 10000 nm or less are preferable.
New

In the electrophotographic photosensitive member of the present invention, the conductive material
Of electrons from the conductive substrate 210 to the photoconductive layer 220
Conductive substrate 210 and photoconductive layer
When the blocking layer 240 is formed between 220
There is. The blocking layer 240 is made of aluminum oxide, nitrided aluminum, or the like.
Lumi, silicon oxide, silicon nitride, a-Si_1-XC_X:
H, a-Si_1-XC_X: X, a-Si_1-XC_X: H, X, a
-Si_1-YN_Y: H, a-Si_1-YN_Y: X, a-Si_1-Y
N_Y: H, X, a-Si_1-ZO_Z: H, a-Si_{1- Z}O_Z:
X, a-Si_1-ZO_Z: Can be formed from H, X, etc.
You. If necessary, these materials may be added to the group 13 or 1
Group 5 elements may be doped. In addition,
The thickness of the printing layer 240 impairs the characteristics of the entire electrophotographic photosensitive member.
In order to suppress the inflow of electrons without
The upper limit is preferably 10,000 nm or less.

In the electrophotographic photoreceptor of the present invention, a charge transport layer 250 may be formed as a lower layer in contact with the photoconductive layer 220. At this time, the photoconductive layer 220 functions as a charge generating layer. It can also be considered that the photoconductive layer is functionally separated into the charge generation layer and the charge transport layer. That is, the charges generated in the charge generation layer are transported to the conductive substrate via the charge transport layer. The charge transport layer 250 having such a function can be made of an a-Si-based material, and the thickness of the charge transport layer 250 can be adjusted with high efficiency without impairing the characteristics of the entire electrophotographic photosensitive member. Is preferably 1 μm or more and 100 μm or less.

FIG. 3 shows an example of an apparatus for producing an electrophotographic photosensitive member having an aC-based surface layer. Using this apparatus, an aC-based surface layer can be formed by a plasma CVD method using a high-frequency power supply.

This apparatus comprises a reaction vessel 301 and an exhaust device (not shown) for reducing the pressure inside the reaction vessel 301. In the reaction vessel 301, a cylindrical conductive base 302 is mounted on a conductive support 303 connected to the ground. A heater (not shown) for heating is built in the conductive receiving table 303 so that the conductive base 302 can be heated to an arbitrary temperature. The conductive pedestal 303 is connected to a rotating motor 312 by a rotating shaft 304, rotates the conductive substrate 302 during film formation, and deposits the film over the entire circumferential direction. A source gas introduction pipe 306 is attached to the reaction vessel 301 so that the source gas can be supplied from a source gas supply device (not shown). The reaction vessel 301 is provided with a cathode electrode 305, and the cathode electrode 305 is
8 to a high frequency power supply 309. A vacuum gauge 310 is attached to the reaction vessel 301 so that the pressure inside the reaction vessel can be measured. Reaction vessel 3
Numeral 01 is connected to an exhaust device (not shown) via an exhaust port 311 and has a structure capable of vacuum exhaust.

Using such an apparatus, an electrophotographic photosensitive member can be produced, for example, by the following procedure. First, a conductive base 302 whose surface is mirror-finished by lathing or the like is mounted on a conductive support 303, and a raw material gas introduction valve 3 is provided.
07 is closed, the reaction vessel 301 is once evacuated by an exhaust device (not shown) through the exhaust port 311, and then the source gas introduction valve 307 is opened to introduce an inert gas for heating, for example, argon gas as a source gas. The gas is introduced into the reaction vessel 301 through the pipe 306, and the evacuation speed of the evacuation device (not shown) and the flow rate of the heating gas are adjusted while monitoring the vacuum gauge 310 so that the inside of the reaction vessel 301 has a desired pressure. Thereafter, a heater (not shown) built in the conductive receiving base 303 is operated to heat the conductive base 302,
The conductive substrate 302 is controlled to a predetermined temperature. When the conductive substrate 302 is heated to a desired temperature, the source gas introduction valve 307 is closed to stop the gas from flowing into the reaction vessel 301.

Next, a predetermined raw material gas, for example, a material gas such as silane gas, disilane gas, methane gas or ethane gas, and a doping gas such as diborane gas or phosphine gas are mixed by a mixing panel (not shown) from a gas supply device (not shown). After that, the mixture is gradually introduced into the reaction vessel 301 through the source gas introduction valve 307. next,
Each raw material gas is adjusted to a predetermined flow rate by a mass flow controller (not shown). At that time, the evacuation speed is adjusted while watching the vacuum gauge 310 so that the inside of the reaction vessel 301 has a predetermined pressure.

After the preparation for film formation is completed by the above procedure, a photoconductive layer is formed on the conductive substrate 302. After confirming that the pressure has stabilized, the high-frequency power supply 309 is set to a desired power, high-frequency power is supplied to the cathode electrode 305 through the matching box 308, and high-frequency glow discharge is generated as plasma. At this time, the matching box 308 is operated to adjust the reflected wave to be minimum,
A value obtained by subtracting the reflected power from the high-frequency incident power is set as a desired value. This discharge energy causes the reaction vessel 301
Each raw material gas introduced into the inside is decomposed, and the conductive substrate 30 is decomposed.
A predetermined deposited film is formed on the surface 2. After the formation of the desired film thickness, the supply of the high-frequency power is stopped, and the reaction vessel 301 is stopped.
After the flow of each source gas into the reaction vessel 301 is stopped and the inside of the reaction vessel 301 is once pulled up to a high vacuum, the formation of the layer is terminated. In addition, a blocking layer, a charge transport layer, a buffer layer, and the like can be formed in addition to the photoconductive layer by the same operation as described above.

Next, the aC-based surface layer of the present invention is formed. Once the inside of the reaction vessel 301 is pulled up to a high vacuum,
A predetermined source gas, for example, CH
₄ , a reaction gas after mixing hydrocarbon gases such as C ₂ H ₆ , C ₃ H ₈ , C ₄ H ₁₀ and other material gases such as hydrogen gas, helium gas, and argon gas as required by a mixing panel (not shown). Introduced into 301. Next, each raw material gas is adjusted to a predetermined flow rate by a mass flow controller (not shown). At that time, the evacuation speed is adjusted while watching the vacuum gauge 310 so that the inside of the reaction vessel 301 has a predetermined pressure. After confirming that the pressure has stabilized, the high-frequency power supply 309 is set to a desired power, and the power is reduced to the cathode electrode 30.
5 to generate high-frequency glow discharge as plasma. At this time, operating the matching box 308,
Adjustment is made so that the reflected wave is minimized, and a value obtained by subtracting the reflected power from the high-frequency incident power is set as a desired value. Each source gas introduced into the reaction vessel 301 is decomposed by this discharge energy, and a predetermined aC-based deposited film is formed on the photoconductive layer. After the desired film thickness is formed, the supply of the high-frequency power is stopped, the flow of each source gas into the reaction vessel 301 is stopped, and the deposition chamber is once pulled up to a high vacuum, and then the formation of the surface layer is completed.

During the film formation, the conductive substrate 302 is rotated at a predetermined speed by the rotating motor 312 so that the film is deposited on the entire circumference of the conductive substrate 302.

In the present invention, in the step of forming the surface layer, the reaction apparatus is controlled so that the deposition rate of the surface layer increases as the pressure in the reaction vessel increases. In this case, a-
As the manufacturing conditions of the C-based film, the relationship between the pressure in the reaction vessel and the deposition rate may be examined in advance, and the film-forming conditions may be set so that the two are proportional to each other. After that, the relationship between the pressure inside the reaction vessel and the deposition rate when the surface layer is formed may be examined.

The substance that can serve as a carbon supply gas used in the present invention includes CH ₄ , C ₂ H ₆ , C ₃ H ₈ , C ₄ H ₁₀ ,
Hydrocarbon compounds in the gaseous state at normal temperature and normal pressure, such as C ₂ H ₂ ,
Hydrocarbon compounds that can be gasified under film forming conditions can be mentioned. From the viewpoint of carbon supply efficiency, CH ₄ , C ₂ H ₆ ,
C ₂ H ₂ is preferred. Further, these raw material gases for supplying carbon may be diluted with a gas such as H ₂ , He, Ar, Ne or the like, if necessary. Further, as a halogen atom supply gas, F ₂ , BrF, ClF, ClF ₃ , BrF
_In some cases, a halogen compound such as BrF ₅ , IF ₃ , IF ₇ may be mixed. From the viewpoint of halogen supply efficiency, CF ₄ ,
CHF ₃ , C ₂ F ₆ , ClF ₃ , CHClF ₂ , C ₃ F ₈ , C ₄
Fluorine-containing gas of F ₁₀ or the like is preferably used.

In the electrophotographic photosensitive member of the present invention, the fusion of the toner is suppressed, the recovery rate of the toner is high, the uneven polishing by the cleaning blade is suppressed, and the transfer efficiency of the toner is high. Since uniform image formation is realized, the electrophotographic photoreceptor of the present invention can be provided in an electrophotographic apparatus to provide an electrophotographic apparatus with excellent performance.

FIG. 4 shows an electrophotographic photosensitive member 501 of the present invention.
A high-speed copying machine is shown as an example of the electrophotographic apparatus provided with. Around the electrophotographic photosensitive member 501, a corona charger 502 having a built-in charger wire, an electric latent image forming portion 5
03, developing unit 504, transfer material supply system 505, transfer unit 50
6 (a), an image fixing device 506 (b) incorporating a heater for image fixing, a toner collecting device 525 incorporating a cleaning blade 521, a transport system 508, a light source 50 for static elimination.
9 and so on.

In such a high-speed copying machine, the lamp 5
Light emitted from 10 is reflected on a document 512 placed on a document table glass 511, is imaged by a lens 518 in a lens unit 517 via mirrors 513, 514, 515, and is formed via a mirror 516. The light carrying the information is projected onto the electric latent image forming portion 503, and the optical information is converted into electrostatic information on the electrophotographic photoreceptor 501 to form an electric latent image. Prior to the formation of the electric latent image, the electrophotographic photosensitive member 501 is uniformly charged by the corona charger 502 to which a high voltage of +6 to 8 kv has been applied.

In the developing unit 504, a toner is supplied to the electric latent image and developed to form a toner image. On the other hand, the transfer material P such as paper is supplied to the transfer device 506 (a) via the transfer material supply system 505, the timing of leading end supply being adjusted by the registration roller 522. In the transfer unit 506 (a), the toner image is transferred to the transfer material P, and heated in the image fixing unit 506 (b) to fix the toner image. Thereafter, the transfer material P is transferred to the feeding system 50.
8 and is scattered out of the apparatus.

The toner remaining on the electrophotographic photosensitive member 501 is removed by a cleaning blade 521 made of an elastic material such as silicone rubber or urethane rubber, and is collected by a toner collecting device 525. Electrophotographic photoreceptor 501
The electric latent image remaining on the upper surface is erased by the light source 509 for static elimination. A blank exposure LED 520 is provided for exposing the electrophotographic photosensitive member 501 in order to prevent toner from adhering to an area exceeding the width of the transfer material P on the electrophotographic photosensitive member 501.

[0056]

The present invention will be described in more detail with reference to the following examples. (Method of Analyzing Characteristics of Surface Layer and Electrophotographic Photoreceptor) (A) Evaluation of Fusing Modification for experiment was performed so that the pressing pressure of the cleaning blade of a high-speed copying machine (NP6060 manufactured by Canon Inc.) was reduced by half. The environment was set to a normal temperature and low humidity environment of 10% at 25 ° C., and a 1% original was used to create a state in which fusing easily occurred, and an acceleration test was performed. An electrophotographic photosensitive member was set in such an accelerated testing machine, and a 100,000-sheet durability test was performed. During and after the durability test, the degree of fusion was evaluated by image quality and observation of the surface layer with a microscope.
The degree of fusion was quantified by a relative value with the number of fusion occurrences on the surface layer of a-SiC: H being 100. The smaller the numerical value is, the smaller the number of occurrences of fusion is, indicating that it is good.

(A) Evaluation of Non-uniform Polishing by Cleaning Blade (Evaluation of Uneven Sharpness) Regarding the surface layer of the electrophotographic photosensitive member subjected to the durability test,
Stylus type surface roughness meter [Surface coder manufactured by Kosaka Laboratory Co., Ltd.]
SE-30D], the surface roughness was measured with a width of 25 mm in the axial direction, and the average surface roughness (Ra) was calculated. The degree of non-uniform polishing was quantified by a relative value when Ra on the surface layer made of a-SiC: H was 100. The smaller the numerical value, the lower the degree of uneven polishing and the better.

(C) Evaluation of Transfer Efficiency An electrophotographic photosensitive member was attached to an experimental high-speed copying machine (a modified NP6060 manufactured by Canon Inc. for experiments) in which waste toner had been cleaned beforehand. Under the conditions, the charging and developing processes were repeated for 20,000 sheets. Thereafter, the mass of the waste toner collected in the cleaning portion and the waste toner container was measured. The transfer efficiency was quantified by a relative value when the mass of the waste toner on the surface layer made of a-SiC: H was 100. The smaller the numerical value is, the higher the transfer efficiency is and the better the transfer efficiency is.

(D) A rough halftone chart of an image is copied, and the image density of the obtained halftone image is measured with an image densitometer (PROCESS MEA).
Macbeth RD914 manufactured by SUREMENTS)
The measurement was carried out in detail over the entire A3 paper using. The degree of roughness of the image was evaluated by dividing the width of the obtained density variation by the average density. The obtained result is a-S
Assuming that the evaluation result on the surface layer composed of iC: H is 100,
Digitized. The smaller the numerical value is, the less the roughness of the image is, indicating that the image is uniform.

(Experimental Example 1) In order to find a film forming condition in which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel, a cylindrical Al is formed under the following conditions while changing the pressure in the reaction vessel. An aC: H film was formed on the conductive substrate of Example 1 and the deposition rate was measured: CH ₄ 200 ml / min (Normal) Temperature of the conductive substrate 100 ° C. High frequency applied power 1000 W High frequency applied power frequency 13.56 MHz Film time 30 minutes The results obtained are plotted in FIG. From this figure, the pressure in the reaction vessel is set to 50 P
It has been found that by setting the ratio to a or less, a film forming condition in which the deposition rate of the surface layer increases as the pressure in the reaction vessel increases can be satisfied.

(Experimental Example 2) a-
An electrophotographic photoreceptor having a surface layer made of SiC: H was prepared by the following procedure. First, a blocking layer was formed on a cylindrical Al substrate under the following conditions: SiH ₄ 200 ml / min (Normal) H ₂ 500 ml / min (Normal) NO 5 ml / min (Normal) B ₂ H ₆ 2000 ppm Conductive substrate Temperature 250 ° C. Pressure in reaction vessel 80 Pa High frequency applied power 150 W Film thickness 1.5 μm.

Next, a photoconductive layer was formed under the following conditions: SiH ₄ 510 ml / min (Normal) H ₂ 450 ml / min (Normal) Temperature of conductive substrate 250 ° C. Pressure in reaction vessel 73 Pa High frequency applied power 450 W film thickness 20 μm.

Subsequently, a surface layer made of a-SiC: H was formed under the following conditions: SiH ₄ 10 ml / min (Normal) CH ₄ 200 ml / min (Normal) Conductive substrate temperature 250 ° C. In a reaction vessel Pressure 67 Pa High frequency applied power 1000 W Film thickness 0.3 μm.

(Examples 1 to 5) Electrophotographic photoreceptors AE After forming a blocking layer and a photoconductive layer in the same manner as in Experimental Example 2, the pressure in the reaction vessel was changed as shown in Table 1. Electrophotographic photosensitive member A in the same manner as in Experimental Example 1.
To E were prepared.

(Comparative Examples 1 and 2) Electrophotographic photosensitive members F and G The electrophotographic photosensitive members F and G were prepared in the same manner as in Examples 1 to 5 except that the pressure in the reaction vessel was set to the value shown in Table 1. Produced.

Table 1 shows the evaluation results of the electrophotographic photosensitive members manufactured in the above Examples and Comparative Examples. From this, a
By forming the surface layer of -C: H under film-forming conditions in which the deposition rate of the surface layer increases as the pressure in the reaction vessel increases, the fusion of the toner is suppressed, and the toner recovery rate is high.
It was found that non-uniform polishing by the cleaning blade was suppressed, the toner transfer efficiency was good, and an electrophotographic photoreceptor capable of forming a uniform image could be produced.

[0067]

[Table 1] (Example 6-10) electrophotographic photosensitive member H~L was first deposited under the following conditions a blocking layer on the cylindrical Al _{substrate: SiH 4 200ml / min (Normal} ) H 2 500ml / min (Normal) NO 5 ml / min (Normal) B ₂ H ₆ 2000 ppm Temperature of conductive substrate 300 ° C. Pressure in reaction vessel 80 Pa High frequency applied power 150 W Film thickness 1.5 μm.

Next, a photoconductive layer was formed under the following conditions: SiH ₄ 510 ml / min (Normal) H ₂ 450 ml / min (Normal) Temperature of conductive substrate 300 ° C. Pressure in reaction vessel 73 Pa High frequency applied power 450 W film thickness 20 μm.

Subsequently, a buffer layer was formed under the following conditions: SiH ₄ 20 ml / min (Normal) CH ₄ 600 ml / min (Normal) Temperature of conductive substrate 300 ° C. Pressure in reaction vessel 53 Pa High frequency applied power 500 W Film thickness 0.5 μm.

An aC: H surface layer was formed on the buffer layer prepared as described above using C ₂ H ₂ as a gas for supplying carbon under the following conditions. Then, when the film formation conditions under which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel were examined, it was found that the conditions were satisfied at 120 Pa or less. Within this range, the flow rate of the carbon supply gas was changed and the deposition rate of the surface layer was changed as shown in Table 2. Temperature of conductive substrate 200 ° C. Pressure in reaction vessel 107 Pa High-frequency applied power 1800 W High-frequency applied power Frequency 13.56 MHz, film thickness 0.5 μm.

The electrophotographic photosensitive members H to L produced as described above were evaluated, and the results are shown in Table 2. From this, it was found that the characteristics of the electrophotographic photosensitive member were particularly excellent when the deposition rate of the surface layer was 2 nm / sec or less. On the other hand, when the deposition rate is less than 0.01 nm / sec, it takes a long time to form a film, which is not practical.

[0072]

[Table 2] (Examples 11 to 15) Electrophotographic photosensitive members M to Q In the same manner as in Examples 6 to 10, a blocking layer, a photoconductive layer, and a buffer layer were laminated. Thereafter, an aC: H surface layer was formed under the following conditions. Then, when the film formation conditions under which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel were examined, it was found that the condition was satisfied at 800 Pa or less. Within this range, the pressure in the reaction vessel was varied as shown in Table 3: CH ₄ 50 ml / min (Normal) Temperature of conductive substrate 150 ° C. High frequency applied power 2000 W High frequency applied power frequency 13.56 MHz Film thickness 0.6 μm.

The electrophotographic photosensitive members M to Q produced as described above were evaluated, and the results are shown in Table 3. From this, it was found that the characteristics of the electrophotographic photosensitive member were particularly excellent when the pressure in the reaction vessel was 665 Pa or less.

[0074]

[Table 3] (Examples 16 to 22) Electrophotographic Photoreceptors R to X In the same manner as in Examples 6 to 10, a blocking layer, a photoconductive layer, and a buffer layer were laminated. Thereafter, a surface layer of aC: H was formed under the following conditions using CH ₄ as a gas for supplying carbon. Then, when the film formation conditions under which the deposition rate of the surface layer also increases with an increase in the pressure in the reaction vessel were examined,
It was found that the condition was satisfied at 80 Pa or less. Within this range, the CH ₄ flow rate was manipulated to change ΔDr / ΔPress as shown in Table 4: Temperature of conductive substrate 50 ° C. High frequency applied power 1500 W Frequency of high frequency applied power 13.56 MHz Film thickness 0. 3 μm.

The electrophotographic photosensitive members R to X produced as described above were evaluated, and the results are shown in Table 4. From this, ΔD
r / ΔPress is 7.5 × 10 ⁻⁵ nm / sec · Pa
In the case of not less than 7.5 × 10 ⁻³ nm / sec · Pa,
In particular, it was found that the characteristics of the electrophotographic photosensitive member were excellent.

[0076]

[Table 4] (Examples 23 to 27) The high frequency power supply and the matching box of the electrophotographic photoreceptors Y to AC were set to VH
The electrophotographic photoconductors Y to AC were manufactured according to the following procedure, with the frequency of the high frequency applied power being 105 MHz for F.

First, a blocking layer was formed on a cylindrical Al substrate under the following conditions: SiH ₄ 150 ml / min (Normal) H ₂ 300 ml / min (Normal) NO 5 ml / min (Normal) B ₂ H ₆ 3000 ppm Temperature of conductive substrate 200 ° C. Pressure in reaction vessel 0.8 Pa High frequency applied power 180 W Film thickness 1.5 μm.

Next, a photoconductive layer was formed under the following conditions: SiH ₄ 450 ml / min (Normal) H ₂ 6000 ml / min (Norma
l) Temperature of conductive substrate 200 ° C. Pressure in reaction vessel 1.33 Pa High frequency applied power 360 W Film thickness 20 μm.

Subsequently, a buffer layer was formed under the following conditions: SiH ₄ 20 ml / min (Normal) CH ₄ 100 ml / min (Normal) Temperature of conductive substrate 200 ° C. Pressure in reaction vessel 0.53 Pa High frequency application Power 100W Film thickness 0.5μm.

An aC: H surface layer was formed on the buffer layer prepared as described above under the following conditions. Then, when the film forming conditions under which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel were examined, it was found that the condition was satisfied at 30 Pa or less. Within this range, the pressure in the reaction vessel was varied as shown in Table 5: CH ₄ 200 ml / min (Normal) Conductive substrate temperature 200 ° C. High frequency applied power 1000 W Film thickness 0.2 μm.

The electrophotographic photosensitive members Y to AC produced as described above were evaluated, and the results are shown in Table 5. From this, it was found that the characteristics of the obtained electrophotographic photosensitive member were excellent even when the high-frequency applied power was in the VHF band at a frequency of 50 to 450 MHz. In addition, it was also found that the use of high-frequency applied power in the VHF band can further reduce the pressure in the reaction vessel, so that dust such as polysilane in the reaction vessel can be suppressed, which is more preferable.

[0082]

[Table 5] (Examples 28 to 32) In the same manner as in Examples 6 to 10, a blocking layer, a photoconductive layer and a buffer layer were laminated.
Thereafter, a surface layer of aC: H, F was formed under the following conditions. Then, when the film formation conditions under which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel were examined, it was found that the condition was satisfied at 150 Pa or less. Within this range, the pressure in the reaction vessel is increased to 13.3 Pa, 40 Pa, 66.5 Pa, 9
Changed to 3 Pa and 133 Pa: CH ₄ 100 ml / min (Normal) CF ₄ 200 ml / min (Normal) Conductive substrate temperature 100 ° C. High frequency applied power 600 W High frequency applied power frequency 13.56 MHz Film thickness 0.3 μm.

When the electrophotographic photosensitive member produced as described above was evaluated, it was found that the characteristics of the electrophotographic photosensitive member were excellent as in Examples 1 to 5.

[0084]

As is apparent from the above description, a-C
By producing the surface layer of the system under film forming conditions in which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel,
An electrophotographic photoreceptor capable of suppressing fusion of toner, high toner recovery rate, non-uniform polishing by a cleaning blade, good transfer efficiency of toner, and forming a uniform image. Can be made.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a relationship between a deposition rate of a surface layer and a pressure in a reaction vessel.

FIG. 2 is a schematic sectional view for explaining an example of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a schematic diagram for explaining an apparatus for forming an electrophotographic photosensitive member.

FIG. 4 is a schematic diagram for explaining the electrophotographic apparatus of the present invention.

FIG. 5 is a view showing an experimental example of a relationship between a deposition rate of a surface layer and a pressure in a reaction vessel.

[Explanation of symbols]

 210 conductive substrate 220 photoconductive layer 230 surface layer 240 blocking layer 250 charge transport layer 260 buffer layer 301 reaction vessel 302 conductive substrate 303 conductive pedestal 304 rotating shaft 305 cathode electrode 306 source gas introduction pipe 307 source gas introduction valve 308 Matching box 309 High-frequency power supply 310 Vacuum gauge 311 Exhaust port 312 Rotating motor 501 Electrophotographic photosensitive member 502 Corona charger 503 Electrical latent image forming portion 504 Developing device 505 Transfer material supply system 506 (a) Transfer device 506 (b) Image fixing Container 508 Transport system 509 Light source for static elimination 510 Lamp 511 Platen glass 512 Document 513 Mirror 514 Mirror 515 Mirror 516 Mirror 517 Lens unit 518 Lens 520 Blank exposure LED 521 Cleaner Grayed blade 522 resist roller 525 the toner recovery unit P transfer material

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G03G 5/08 360 G03G 5/08 360 C23C 16/26 C23C 16/26 16/32 16/32 16/505 16/505 G03G 5/00 101 G03G 5/00 101 (72) Inventor Ryuji Okamura 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H068 CA03 DA05 DA06 DA07 DA12 DA19 DA46 DA51 EA24 EA33 EA34 4K030 AA09 AA17 BA27 BB12 CA02 CA07 CA16 FA01 GA07 JA01 JA09 JA12 LA17

Claims (12)

[Claims] An electrophotographic photoreceptor comprising at least an amorphous silicon-based photoconductive layer formed on a conductive substrate and an amorphous carbon-based surface layer formed on the photoconductive layer. Thus, the surface layer is formed under the condition that the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel.
An electrophotographic photosensitive member formed by a plasma CVD method. 2. The thickness of the surface layer is 5 nm or more and 100 or more.
2. The electrophotographic photosensitive member according to claim 1, wherein the thickness is 0 nm or less. 3. The photoconductive layer has a thickness of 1 μm or more and 10 μm or more.
3. The electrophotographic photoreceptor according to claim 1, wherein the thickness is 0 μm or less. 4. Between the photoconductive layer and the surface layer,
2. A buffer layer is formed.
4. The electrophotographic photosensitive member according to any one of items 1 to 3, 5. The electrophotographic photosensitive member according to claim 1, wherein the buffer layer is made of an amorphous silicon carbide, an amorphous silicon nitride, or an amorphous silicon oxide. 6. The electrophotographic photoreceptor according to claim 1, wherein a blocking layer is formed between the conductive substrate and the photoconductive layer. 7. The electrophotographic photoreceptor according to claim 1, wherein a charge transport layer is formed as a lower layer in contact with said photoconductive layer. 8. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1. 9. Production of an electrophotographic photoreceptor comprising at least an amorphous silicon-based photoconductive layer formed on a conductive substrate and an amorphous carbon-based surface layer formed on the photoconductive layer. Forming the photoconductive layer by a plasma CVD method;
Forming the surface layer by a plasma CVD method under a condition in which the deposition rate of the surface layer increases with an increase in the pressure in the reaction vessel. 10. In the step of forming the surface layer,
The method according to claim 9, wherein the pressure in the reaction vessel is 665 Pa or less. 11. In the step of forming the surface layer,
The deposition rate of the surface layer is 0.01 nm / sec or more and 2 n
10. The method according to claim 9, wherein the speed is not more than m / sec.
0. The method for producing an electrophotographic photosensitive member according to item 0. 12. The step of forming the surface layer,
The ratio (ΔDr / ΔP) of the change in deposition rate (ΔDr) of the surface layer to the change in pressure (ΔPress) in the reaction vessel.
The electrophotographic photoreceptor according to any one of claims 9 to 11, wherein (res) is 7.5 x ^10-5 nm / sec-Pa or more and 7.5 x ^10-3 nm / sec-Pa or less. Manufacturing method.