JP2818882B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electrophotographic photosensitive member having a surface protective layer on an organic photosensitive layer.

2. Description of the Related Art Conventionally, as a photoreceptor used in an electrophotographic method, a photoconductive material in which an inorganic photoconductive material such as selenium is dispersed in a binder on a conductive support, poly-N-vinylcarbazole And those using an organic photoconductive material such as trinitrofluoreon or azo pigment, and those using an amorphous silicon-based material.

The term "electrophotographic method" as used herein generally means that a photoconductive photoreceptor is first charged in a dark place, for example, by corona discharge, and then subjected to image exposure to selectively dissipate the charges in only the exposed portions, thereby reducing the static electricity. An electrostatic latent image is obtained, and the latent image portion is developed and visualized with an inspection fine particle (toner) composed of a coloring material such as a dye or a pigment and a binder such as a polymer substance to form an image. This is one of the image forming methods.

The basic characteristics required of the photoreceptor in such an electrophotographic method are as follows: (1) The photoreceptor can be charged to an appropriate potential in a dark place.

(2) Dissipation of electric charge is not easy in a dark place.

(3) The charge can be quickly dissipated by light irradiation.

And the like.

Each of the above photoreceptors has excellent characteristics and disadvantages in practical use in addition to these basic characteristics. Among them, in recent years, the production cost is low, the environmental pollution is small, and the relatively free photoreceptor is used. Organic photoconductors have been remarkably developed for reasons such as design.

Generally, an organic photoreceptor is one in which a charge transport material is dispersed or dissolved in a binder resin and coated on a conductive support, and has a single layer function of charge retention, charge generation, and charge transport. Single layer type charge generation layer (CGL) with charge generation function, charge transfer layer (CTL) with charge retention and transport function of charge injected from CGL, and optionally from support A function-separated type in which a layer having a function of preventing charge injection or preventing light reflection on a support or the like is laminated is known.

These organic photoreceptors have excellent characteristics as described above, but have a low surface hardness because of the organic material, and are mechanically exposed to a developer, a cleaning member, etc. during actual use in a copying process. There is also an inherent disadvantage that the load is liable to wear and scratches.

This abrasion of the photosensitive layer causes a decrease in the charging potential,
Local flaws cause streak-like abnormal images on a copy, and are all important problems that affect the life of the photoconductor.

In order to solve such disadvantages, a method has been proposed in which a protective layer is provided on the surface of the organic photosensitive layer to improve the durability against the mechanical load applied inside and outside the copying machine.

For example, a method of providing an organic film on the surface of a photoreceptor layer (Japanese Patent Publication No. 38-15446), a method of providing an inorganic oxide (Japanese Patent Publication No. 43-14517), a method of providing an adhesive layer and then laminating an insulating layer (Japanese Patent Publication No. 43-27591), or plasma CVD method, optical CV
A method of laminating an a-Si layer, a-Si: N: H layer, a-Si: O: H layer, etc. by the D method or the like (Japanese Patent Application Laid-Open Nos. 547-179859 and 59-58437).
Are disclosed. In recent years, the application of a high-hardness diamond-like carbon film to a protective layer has been activated. For example, a photosensitive layer provided with a protective layer made of amorphous carbon or hard carbon (JP-A-60-249155) and a protective layer provided with a diamond-like carbon protective layer on the outermost surface (JP-A-61-25535)
2), a high-hardness insulating layer containing carbon as a main component formed on a photosensitive layer (Japanese Patent Laid-Open No. 61-264355), or a plasma containing at least atoms such as nitrogen atoms and alkali metal atoms on an organic photosensitive layer. With a protective layer composed of an organic polymer film (Japanese Patent Laid-Open No. 63-97961-4), generated by glow discharge containing at least atoms such as chalcogen, III, IV and V on the organic photosensitive layer Provided with a protective film made of a coated amorphous hydrocarbon film (JP-A-63-220166-9).

In each of these proposals, carbon or a carbon-based high-hardness thin film (i-carbon film or carbon-based film) formed on the surface of an organic photosensitive layer by an ion process (sputtering, plasma CVD, glow discharge method, CVD method, etc.). Diamond-like carbon film).

"Problems to be Solved by the Invention" By such a method, the surface hardness of the organic photosensitive layer can be increased. However, the adhesion between the high-hardness protective layer and the organic photosensitive layer is not sufficient, and when used in a copying machine, peeling occurs at the interface between the protective layer and the organic photosensitive layer. The problem of poorness then became apparent.

The present invention improves the adhesion between the organic photosensitive layer and a protective layer composed of carbon or a carbon-based film to solve these problems, and has excellent long-term mechanical durability. It is intended to provide an electrophotographic photosensitive member.

"Means for Solving the Problems" In the present invention, an organic photosensitive layer, an intermediate layer if necessary, and a protective layer on the outermost surface are laminated in this order on a conductive support to achieve the above object. In the electrophotographic photoreceptor of the present invention, the protective layer is made of carbon or a film containing carbon as a main component, and the organic photosensitive layer or an intermediate layer provided as required is compared with the carbon or carbon as a main component. The concentration of oxygen, water or an oxygen compound at or near the interface with the substrate is 1 atomic% or less.

The present inventors have conducted research to improve the adhesion between the organic photosensitive layer and a comparison containing carbon or carbon as a main component, and found that 6 to 36 atomic% of oxygen exists on the outermost surface of the organic photosensitive layer, ~ 1
Auger electron spectroscopy revealed that at a depth of 000 °, the oxygen atom concentration was less than one sixth of the outermost surface.
In addition, when a film mainly composed of carbon or carbon is deposited on the organic photosensitive layer without performing intentional treatment, the adhesion between the organic photosensitive layer and the film mainly composed of carbon or carbon can be improved. Although the property is poor, the plasma treatment of the photosensitive layer surface with plasma such as H ₂ , N ₂ , Ar, etc. It is also clear that the minimum number of atoms that can be detected by Auger electron spectroscopy, that is, 1 atomic% or more of oxygen, is not present at the interface between the processed photosensitive layer and the carbon or carbon-based film. The inventors have discovered.

In the case of plasma treatment of the surface of the photoreceptor layer with a plasma of H ₂ , N ₂ , Ar, etc., a bias is applied by an electric field of 1 to 500 KHz by a power source provided separately from an excitation source for generating plasma on the photoreceptor serving as a substrate. It was also found that the effect was more remarkable when was added positively, and the present invention was reached.

"Constitution of the Invention" As the conductive support used in the present invention, a conductor or an insulator subjected to a conductive treatment is used.

For example, a metal such as Al, Ni, Fe, Cu, Au or the like, or a metal such as Al, Ag, Au or the like, or In ₂ O ₃ , SnO ₂
Examples of such materials include those formed with a thin film of a conductive material such as paper, and paper that has been subjected to a conductive treatment.

The shape of the conductive support is not particularly limited, and may be a plate, a drum, or a belt as needed.

Organic photosensitive layers provided directly on the conductive support or via an undercoat layer include a single layer type and a function separation type as described above.

Examples of the single-layer photosensitive layer include dye-sensitized zinc oxide,
Photoconductive powders such as titanium oxide and zinc sulfide, selenium powder,
An amorphous silicon powder, a squaric salt pigment, a phthalocyanine pigment, an azulhenium salt pigment, an azo pigment, or the like, optionally coated with a binder resin and / or an electron-donating compound described later, or a pyrylium dye. Examples include those using a composition in which an electron-donating compound is added to a eutectic complex formed from bisphenol A-based polycarbonate. As the binder resin, the same resin as the function-separated type photosensitive layer described later can be used. The thickness of the single-layer type photosensitive layer is suitably from 5 to 30 μm.

On the other hand, a charge generation layer (CGL) for generating and separating latent image charges by image exposure in the function-separated type photosensitive layer is made of inorganic photoconductive powder such as crystalline selenium or arsenic selenide or an organic dye. What is dispersed or dissolved in an adhesive resin is used.

As an organic dye / pigment as a charge generating substance, for example, C.I. Pigment Blue 25 [color index (CI) 21
180], CI Pigment Red 41 (CI21200), CI Acid Red 52 (CI 45100), CI Basic Red 3 (CI 45210), and a phthalocyanine pigment having a porphyrin skeleton, an azulenium salt pigment, a squaric salt pigment, and a carbazole skeleton Azo pigments having a styrylstilbene skeleton (described in JP-A-53-138229) and azo pigments having a triphenylamine skeleton (described in JP-A-53-138229). JP-A-132547), an azo pigment having a dibenzothiofin skeleton (described in JP-A-54-21728),
Azo pigments having an oxadiazole skeleton (JP-A-54-12
742), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), distyryl oxadi Azo pigments having an azole skeleton (described in JP-A-54-2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-2129), and azo pigments having a distyrylcarbazole skeleton (see JP-A-54-17734), triazo pigments having a carbazole skeleton (JP-A-57-195767, JP-A-57-195767)
195768), phthalocyanine pigments such as C.I. Pigment Blue 16 (CI 74100), indigo pigments such as C.I.Bad Brown 5 (CI 73410), C.I. Perylene pigments such as Red B (manufactured by Van Ollet) and Indus Scarlet R (manufactured by Bayer) can be used.

These charge generating substances are used alone or in combination of two or more.

The binder resin is used in an amount of 0 to 1 based on 100 parts by weight of the charge generating substance.
100 parts by weight, preferably from 0 to 50 parts by weight.
Parts by weight.

Examples of the binder resin used in combination with these organic dyes and pigments include condensation resins such as polyimide, polyurethane, polyester, epoxy resin, polycarbonate, and polyether, and polystyrene, polyacrylate, polymethacrylate, poly-N-vinylcarbazole, and polyvinyl. Butyral, styrene-butadiene copolymer, styrene
Polymers such as acrylonitrile copolymers and adhesive and insulating resins such as copolymers can be used.

The charge generation layer is formed by dispersing the charge generation substance together with a binder resin, if necessary, using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, or dichloroethane using a ball mill, an attritor, or a sand mill.
It can be formed by appropriately diluting the dispersion and applying it. The coating can be performed by a dip coating method, a spray coating method, a bead coating method, or the like. The thickness of the charge generation layer is suitably about 0.01 to 5 μm, and preferably 0.1 to 2 μm.

When particles such as crystalline selenium or arsenic selenide alloy are used as the charge generating substance, they are used in combination with an electron donating binder and / or an electron donating organic compound. Examples of such an electron donating substance include polyvinyl carbazole and derivatives thereof (for example, those having a carbazole skeleton having a halogen such as chlorine or bromine, a substituent such as a methyl group or an amino group), polyvinyl pyrene, oxadiazole, pyrazoline, hydrazone. , Diarylmethane, α-phenylstilbene, nitrogen-containing compounds such as triphenylamine-based compounds, and diarylmethane-based compounds, but polyvinyl carbazole and its derivatives are particularly preferred.
Further, these substances may be used as a mixture. Also in the case of mixing and using, it is preferable to add another electron donating organic compound to polyvinyl carbazole and its derivative. The content of this kind of inorganic charge generating substance is suitably 30 to 90% by weight of the whole layer. When an inorganic charge generation material is used, the thickness of the charge generation layer is suitably 0.2 to 5 μm.

The charge transport layer (CTL) is a layer intended to hold a charge and move the charge generated and separated in the charge generation layer by exposure to combine with the charge held. High electrical resistance is required to achieve the purpose of retaining the charged electric charge, and in order to achieve the purpose of obtaining a high surface potential with the retained charged electric charge, a low dielectric constant and good charge mobility are required. Required.

The charge transport layer for satisfying these requirements is composed of a charge transport material and a binder resin used as needed. That is, the charge transport layer can be formed by dissolving or dispersing the above substances in an applicable solvent and applying and drying the same.

The charge transport materials include a hole transport material and an electron transport material.

Examples of the hole transport material include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline,
Electron donating substances such as phenylhydrazones and α-phenylstilbene derivatives;

Examples of the electron transporting substance include chloroanil, bromanil, tetracyanoethylene, tetracyanoquinonedimethane, 2,4,7-trinitro-9-fluorenone, 2,
4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2- b] Electron accepting substances such as thiophen-4-one, 1,3,7-trinitrodibenzothiophenone-5,5-dioxide.

These charge transport materials are used alone or in combination of two or more.

Examples of the binder resin used as needed include polystyrene, styrene-acrylonitrile copolymer, styrene-butazineene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, and the like.
Vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic Thermoplastic or thermosetting resins such as resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride and the like are used.

The thickness of the charge transport layer is suitably about 5 to 100 μm.
Further, a plasticizer or a leveling agent may be added to the charge transport layer. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer is suitably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil are used.
A suitable amount is about weight%.

These CGL and CTL are placed on the support from the support side.
Or CTL and CGL in this order.

The coating of carbon or carbon as a main component and the method of forming the coating according to the present invention are described above.

FIG. 2 shows an example of an apparatus that can be used in the present invention. In the drawing, the reaction vessel (7) of the plasma CVD apparatus
Is divided by a load / unload spare chamber (7 ') and a gate valve (9). In the gas system (30), the carrier gas is from (31), the reactive gas is from (32), the additive gas is from (33), the etching gas for the reaction vessel is from (34), the valve (28), It is introduced into the reaction system (50) through the nozzle (25) through the flow meter (29).

The reaction system (50) has a frame structure (2) (having a square or hexagonal frame structure as viewed from the electrode side) as shown in FIGS. 3 (A) and 3 (B). In the opening of the hood (8), cover the opening
(8 '). The pair of first and second electrodes (3) and (3 ') having the same shape and disposed on the hoods (8) and (8') are made of aluminum metal mesh. The reactive gas is discharged downward from the nozzle (25). The third electrode has an organic photosensitive layer provided on an aluminum cylindrical support, and the photosensitive layer is an insulating material in terms of direct current. It was made conductive and a bias was applied. The formation surface (1 ') on the substrate (1) is formed by a pair of electrodes (3),
It was arranged to be held in the plasma generated in (3 '). The bases (1-1), (1-2),... (1-n), that is, (1) include the surfaces (1′-1), (1′-2),.
(1'-n), and an alternating voltage of 1 to 500 KHz applied with a second alternating voltage and a negative DC bias is applied. In this case, the DC bias is positively generated by the self-bias accumulated by the second AC power supply and the DC power supply in a capacitor (not shown) provided between the second AC voltage source and the third electrode serving as the base. Either of the applied DC bias may be used. The reactive substrate converted into a glow discharge plasma by the first high frequency alternating voltage is uniformly dispersed in the reaction space (60), and the plasma is surrounded by (2), (8), and (8 '). The gas was not released into the outside space (6) outside in the form of plasma so that it did not adhere to the inner wall of the reaction vessel. Further, the plasma potential in the reaction space was made uniform.

Further, in order to make the potential distribution in the plasma reaction space more uniform, alternating voltages of two kinds of frequencies can be applied to the power supply system (40). The first alternating voltage is 1 to
High frequency of 100MHz, a pair of two power supplies (15-
1) From (15-2), matching transformer (16-1),
(16-2). The phase of the matching transformer is adjusted by a phase adjuster so that the phase difference can be supplied by 180 ° or 0 °. The transformer has a symmetric or in-phase output, and one end (4) and the other end (4 ') of the transformer are connected to a pair of first and second electrodes (3),
(3 '). The output middle point (5) of the transformer is kept at the ground level,
Substrates (1-1 '), (1) through an output capacitor (not shown) to which a 500 KHz alternating electric field (17) is applied.
−2 ′),... (1-n ′), that is, (1) or a third electrode of a holder (2) that electrically connects them.

Thus, plasma (60) is generated in the reaction space. The exhaust system (20) discharges unnecessary gas through the pressure control valve (21), the turbo molecular pump (22), and the rotary pump (23).

These reactive gases are present in the reaction space (60) at 0.001 to 1.0
The frame structure (2) has a rectangular shape or a hexagonal shape. For example, in the case of a rectangular shape, the width is as shown in FIG.
75 cm, depth 75 cm, length 50 cm. Then, a cylindrical gas having a surface to be formed is placed therein (1-1 ′), (1-2),.
As shown in (1-n), here 16 are arranged at equal intervals. Dummy base materials (1-0), (1-
n + 1). In such a space, 1-10
0.5MHz to 5KW (0.3 to 3W / c per unit area)
At m ² ), a first high-frequency voltage is applied. Further, by applying an AC bias by the second alternating voltage,-
A negative self-bias voltage of 10 to -600 V is applied, and a reactive gas accelerated by the negative self-bias voltage can be formed on a substrate while being sputtered, and a dense film can be formed. The hardness of the coating can be controlled by controlling the negative self-via voltage, which is one of the features of the carbon film forming method used in the present invention. FIG. 5 shows an example of the relationship between the self-bias voltage and the film hardness.

Hydrogen or argon can be used as a carrier gas, a hydrocarbon gas such as methane or ethylene or a carbon gas such as carbon fluoride as a reactive gas, and a nitride gas such as nitrogen fluoride or ammonia can be used as an additive gas. Oxygen or a fluoride gas such as nitrogen fluoride or carbon fluoride can be used as an etching gas for the reaction vessel. When, for example, ethylene and nitrogen fluoride are introduced as a reaction gas, a diamond-like carbon film to which nitrogen and fluorine are added (also referred to as DLC, including DLC to which additives are added, the present invention mainly includes carbon or carbon). (Referred to as a film as a component).

The reactive gas is, for example, a mixed gas of ethylene and nitrogen fluoride, and the ratio is NF ₃ / C ₂ H ₄ = 1/20 to 4/1. By changing this ratio, the transmittance and the specific resistance can be controlled.

 The temperature of the substrate is typically kept at room temperature.

Typical properties of coating mainly containing carbon or carbon that is produced by the method as described above makes the C-C bonds of similar diamond having SP ³ orbit, Vickers hardness 100
30003000 kg / cm ² , specific resistance (specific resistance) 1 × 10 ⁷ -1 × 10 ¹⁵
It has a property similar to that of a diamond that has a transmittance of 1.0 eV or more, preferably 1.5 to 5.5 eV, in the infrared or visible region, and has an Ωcm and an engineering energy bandwidth (referred to as Eg) of 1.0 eV or more.

The coating of the present invention containing carbon or carbon as a main component is used as a protective layer, and has a thickness of 0.1 to 5 μm, preferably 0.2 to 1 μm, and a specific resistance of 10 ⁸ to 10 ¹³ Ωcm, preferably 10 to 10 Ωcm.
⁹ to 10 ¹² Ωcm is good.

Further, the carbon or the film containing carbon as a main component of the present invention can be laminated in multiple layers.

 Hereinafter, the present invention will be described with reference to Examples.

Example 1 This example shows an example in which carbon or a film containing carbon as a main component is formed on a cylindrical organic photosensitive layer as shown in FIG.

1A and 1B are cross-sectional views of a cylindrical electrostatic copying drum. FIG. 1B is an enlarged view of the main part.

Aluminum cylindrical support (outer diameter 40mmφ, length 250m
In m), a mixture having the following composition ratio was dispersed in a ball mill for 12 hours, and an adjusted undercoating solution was applied by a dipping method so that the film thickness after drying was about 2 μm, thereby forming an undercoat layer.

(Undercoat layer forming liquid)

TiO ₂ (Taipage manufactured by Ishihara Sangyo Co., Ltd.) 1 part by weight Polyamide resin (CM-8000 manufactured by Toray Co., Ltd.) 1 part by weight Methanol 25 parts by weight Dip coating of a charge generation layer coating solution having the following formulation onto the undercoat layer, The tube was dried at 120 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

(Charge generation layer coating solution)

30 parts by weight of trisazo pigment having the following structure 12 parts by weight of a polyester resin (byron manufactured by Toyobo Co., Ltd.) 360 parts by weight of cyclohexane The above mixture is dispersed in a ball mill for 72 hours, and further diluted with 500 parts by weight of a mixed solvent of cyclohexane: methyl ethyl ketone = 1: 1 (weight ratio).

Next, a charge transport layer coating solution having the following formulation was applied onto the charge generation layer by dip coating so that the film thickness after drying was about 20 μm, thereby providing a charge transport layer.

(Charge transport layer coating solution)

In order to remove oxygen adhering to the surface of the organic photosensitive layer in the form of O ₂ , H ₂ O, etc., a plasma treatment with hydrogen was performed.
The H ₂ flow rate was 50 SCCM, plasma was generated by a first alternating electric field (13.56 MHz), and a bias was applied by a second alternating electric field (50 kHz). The DC component of the bias voltage at this time was -100V.

Thereafter, a film containing carbon or carbon as a main component was formed as follows.

Using the apparatus of FIG. 2, the flow rate of NF ₃ was 5 SCCM, the flow rate of C ₂ H ₄ was 80 SCCM, the reaction pressure was 0.05 Torr, the first alternating electric field frequency was 13.56 MHz, the output was 400 W, An alternating electric field frequency of 250 KHz, a voltage amplitude of 100 V, and a DC bias of −50 V, on an organic photoreceptor having a specific resistance of 1 × 10 ¹³ Ωcm with infrared or visible light transmissive amorphous or crystalline structure. 0.8 μm (central portion) of carbon or a coating mainly composed of carbon was formed. Deposition rate is 500
Å / min, Vickers hardness 1500 kg / mm ² , optical energy bandwidth 2.4 eV.

Thus, a film containing carbon as a main component on the organic photosensitive layer as a substrate, particularly containing not more than 30 atomic% of hydrogen in carbon, containing 0.3 to 3 atomic% of fluorine, and containing 0.3 to 10 atomic% of nitrogen Could be formed.

The number of oxygen atoms present at the interface between the photosensitive layer and carbon or a film containing carbon as a main component was 1 atomic% or less.

Example 2 This example is an example in which carbon or a film containing carbon as a main component, which is the protective layer in Example 1, is formed in a 12-layer structure.

After an organic photoconductive layer was formed on the electrostatic copying drum in the same manner as in Example 1, the same plasma treatment as in Example 1 was performed, and then the flow rate of NF ₃ was changed to 5 SCCM and C ₂ H ₄ . Flow rate 80SC
CM, reaction pressure 0.05 Torr, first alternating electric field frequency 13.56 MH
z, its output 400 W, second alternating electric field frequency 250 KHz, its voltage amplitude 100 V, and DC bias -50 V, on an organic photoreceptor, with a specific resistance of 1 × 10 ¹³ Ωcm for infrared or visible light, A first carbon having an amorphous structure or a crystalline structure or a coating mainly composed of carbon was formed at 0.1 μm (central portion). The deposition rate is 500 mm / min, the hardness is Vickers hardness 500 kg / mm ² , and the optical energy bandwidth is 2.4 eV
Had.

Next, the same plasma treatment with H ₂ as in Example 1 was performed again, and the flow rate of NF ₃ was 20 SCCM, the flow rate of C ₂ H ₄ was 80 SCCM, the reaction pressure was 0.05 Torr, and the first alternating electric field was formed on the first film. 13.56MHz frequency, 400W output, 250K second alternating electric field frequency
Hz, a voltage swing of 400 V and a DC bias of -200 V, a second carbon having a translucent aluminum or transparent structure for infrared or visible light having a specific resistance of 1 × 10 ¹¹ Ωcm on an organic photoreceptor. Or 0.5μm of carbon-based coating
(Center). The film formation speed was 400 mm / min, the hardness was Vickers hardness 1800 kg / mm ² , and the optical energy bandwidth was 1.8 eV.

The electrophotographic photoreceptor prepared according to this embodiment is also the same as that of the first embodiment.
As in the case of the above, the number of oxygen atoms between the organic photosensitive layer and the first coating containing carbon or carbon as a main component and between the first coating and the second coating was 1 atomic% or less.

Comparative Example After forming an organic photoconductive layer in the same manner as in Example 1, the plasma treatment as in Example 1 was not performed.
As in Example 1, carbon or a film containing carbon as a main component was formed. The number of oxygen atoms between the organic photosensitive layer and carbon or a film containing carbon as a main component in the electrophotographic photosensitive member prepared according to this comparative example was 3 atomic%.

The photoconductors manufactured in Examples 1 and 2 were subjected to a temperature cycle of −60 ° C. → room temperature → −60 ° C. 100 times on the photoconductors manufactured in these Examples and Comparative Examples. However, the photoreceptors prepared in Comparative Examples had many cracks and peeled off from the substrate in comparison.

Even in actual copying machines, cleaning blades,
Even if a mechanical load is locally applied by the separating claw, copy, etc., no crack or peeling occurs on the protective film (44) of the photoreceptor formed in the first and second embodiments. Even after copying 100,000 sheets of A4 size paper, scratches did not occur on the surface due to rubbing of the copy paper, but the photoreceptor created in the comparative example peeled off after 30,000 copies. did.

FIG. 4 shows an example in which the photoconductors produced in the first and second embodiments are mounted on an actual copying machine.
When an initial copy is made by forming a protective film, an example of the copy is shown in (A), and the result after copying 100,000 sheets is shown in (B). There was little difference between them. In a conventionally known organic photosensitive drum,
Until now, only 20,000 to 30,000 copies could be made, but it was found that this could be increased by a factor of five or more at a time.

In the present embodiment, the case of the H ₂ plasma treatment has been described.
Xe, plasma treatment is performed while accompanied by sputtering effect by the plasma of the rare gas or N ₂ such as Kr, heating the photosensitive drum to 90 to 120 ° C. in a vacuum of 10 ^-3 Torr, 10 ^-5 T
The amount of interfacial oxygen may be reduced to 1 atomic% or less by using an adsorbed gas releasing means such as holding in a high vacuum of orr or less for a long time.

[Effect] The present invention relates to an electrophotographic photoreceptor having a structure in which an organic photosensitive layer, an intermediate layer if necessary, and a protective layer on the outermost surface are laminated in this order on a conductive support. Oxygen, water or an oxygen compound at or near the interface between the organic photosensitive layer or the intermediate layer provided as necessary and the carbon or the film containing carbon as a main component. Since the concentration of oxygen in the alloy was 1 atomic% or less, the adhesion was improved, and the durability against mechanical stress was able to be significantly improved.

[Brief description of the drawings]

FIG. 1 shows an example in which carbon or a film containing carbon as a main component is coated on a cylindrical substrate of the present invention. FIG. 2 shows an outline of a plasma CVD apparatus of the present invention. FIGS. 3 (A) and 3 (B) show a method of disposing a substrate in the plasma CVD apparatus shown in FIG. FIG. 4 shows an example of electrostatic copying using an organic photosensitive drum made by the method of the present invention. FIG. 5 shows the relationship between negative self-bias voltage and hardness.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Naoki Hirose 398 Hase, Atsugi-shi, Kanagawa Semiconductor Energy Research Institute, Inc. (72) Inventor Mari Sasaki 398 Hase, Atsugi-shi, Kanagawa Semiconductor Energy Research Institute, Inc. Inventor Junichi Takeyama 398 Hase, Atsugi-shi, Kanagawa Pref. Semiconductor Energy Laboratory Co., Ltd. (72) Inventor Toshihiko Nakazawa Investigator in Ricoh Company, Ltd. 1-3-6 Nakamagome, Ota-ku, Tokyo (56) JP-A-63-97961 (JP, A) JP-A-1-243068 (JP, A) JP-A-63-88560 (JP, A) JP-A-61-264355 (JP, A) JP-A-63-97962 (JP, A) JP-A-63-264766 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/147 501

Claims (1)

(57) [Claims] 1. The method according to claim 1, wherein the surface of the conductive support has an oxygen concentration of 1%.
An electrophotographic photosensitive layer comprising: an organic photosensitive layer having a concentration of not more than at.%, And a protective layer comprising carbon or a film containing carbon as a main component containing not more than 30 at. Photoconductor.