JP2893207B2 - Electrophotographic method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic method, and more particularly, to a method for maintaining high image quality for a long time in an electrostatic copying method using a Carlson process.

[Conventional technology]

At present, a so-called electrophotographic method using a Carlson process as a copy printing method is most widely used.

Here, in the electrophotographic method, a photoconductive material called a photoreceptor formed on a conductive support is first charged in a dark place (generally, corona discharge is used as a charging means), and then image exposure is performed. Then, the charge of only the exposed portion is selectively developed with fine particles called a toner composed of a coloring material and a binder such as a polymer substance, and then transferred and fixed to an image carrier such as paper to fix the image. This is an image forming method for forming an image.

As a photoreceptor used in the electrophotographic method, a conductive support is provided with a Se or Se alloy (Se-As, Se-T
e, Se-As-Te etc.) provided with a photoconductive layer as a main component, inorganic photoconductive materials such as zinc oxide and cadmium sulfate dispersed in a binder, poly-N-vinyl carbazole and tri- Those using an organic photoconductive material such as nitrofluorenone or azo pigment (OPC) and those using an amorphous silicon-based material are generally known.

 The basic characteristics required of these photoconductors are (1) that they can be charged to an appropriate potential in a dark place.

(2) Dissipation of electric charge in a dark place is small.

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

And the like.

Each of the above-mentioned photoreceptors has excellent characteristics and disadvantages in practical use, in addition to these basic characteristics. For example, a photoreceptor mainly composed of selenium or a selenium alloy (Se-Te, Se-As, Se-Te-As, etc.) has been generally used since the oldest and has excellent light sensitivity. , Mechanical load in electrophotographic process (development cleaning,
However, there is a disadvantage that the image quality is easily affected (white tin, black stripes, etc.) by surface scratches caused by paper jams.

Amorphous silicon photoreceptors have extremely high surface hardness and relatively high photosensitivity, but their production costs are high. There is a problem that the surface is chemically degraded and abnormal images such as image deletion are likely to occur.

Furthermore, in recent years, manufacturing costs are low, environmental pollution is low,
Organic photoreceptors have been remarkably developed, for example, because a relatively free photoreceptor can be designed.

Generally, an organic photoreceptor is a material in which a charge generating material and a charge transporting material are dispersed or dissolved in a binder resin and coated on a conductive support. Single layer type with transport function and charge generation layer (CGL) with charge generation function, charge transport layer (CT with charge retention and transport function of charge injected from CGL)
L), and a function-separated type having a structure in which a layer having a function of preventing charge injection from the support or preventing light reflection on the support as necessary is laminated. Have been.

These organic photoreceptors have excellent characteristics as described above, but because of the organic material, the surface hardness is low,
There is also an essential disadvantage that abrasion and scratches are likely to occur due to a mechanical load received from a developer, transfer paper, a cleaning member, and the like during actual use in a copying process.

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.

A method has been proposed in which a protective layer is provided on the surface of the photosensitive layer to improve the durability against the mechanical load received inside and outside the copying machine in order to eliminate such shortcomings of the mechanical durability of the Se-based and OCPC-based systems. I have.

For example, a method of providing an organic film on the surface of a photosensitive layer (Japanese Patent Publication No. 38-015446), a method of providing an inorganic oxide (Japanese Patent Publication No. 43-014517), a method of providing an adhesive layer and then laminating an insulating layer (Japanese Patent Publication No. 43-027591), or plasma CVD method, optical C
A method of laminating an a-Si layer, an s-Si: N: H layer, an a-Si: O: H layer and the like by a VD method or the like (Japanese Patent Laid-Open Nos. 57-179859 and 59-0584).
37) is disclosed.

These methods have the advantage of improving the mechanical durability of the photoreceptor. However, when the organic film is laminated, a solvent that does not affect the organic photoreceptor must be used.
Further, the silicon-based protective layer has an essential problem that it is liable to be chemically degraded by O ₃ or the like as described above, and there are many problems that must be solved in practical use.

Against this background, the application of carbon or a high-hardness thin film containing carbon as a main component as a material for a protective layer of a photoreceptor has recently been active.

For example, a photosensitive layer provided with a protective layer made of amorphous carbon or hard carbon (Japanese Patent Application Laid-Open No. 60-249155), and a protective layer provided with a diamond-like carbon protective layer on the outermost surface (Japanese Patent Application Laid-Open No. Sho 61-249155)
-255352), a high-hardness insulating layer containing carbon as a main component formed on a photosensitive layer (Japanese Patent Laid-Open No. 264355/1986), or a nitrogen atom, oxygen atom, halogen atom, alkali metal atom or the like on an organic photosensitive layer. Provided with a protective layer comprising a plasma organic polymer film containing at least atoms (Japanese Patent Application Laid-Open No. 63-97961)
4), chalcogen atom, group III atom, IV on organic photosensitive layer
One provided with a protective layer made of an amorphous hydrocarbon film generated by glow discharge containing at least an atom such as a group atom or a group V atom (Japanese Patent Application Laid-Open No. 63-220166-9).

In each of these proposals, carbon or a high-hardness thin film containing carbon as a main component (i-carbon film or i-carbon film) formed on the surface of a photoreceptor by an ion process (sputtering, plasma CVD, glow discharge decomposition, photo CVD, etc.) A diamond-like carbon film).

In these methods, since the protective layer is obtained by a film forming process without using a solvent, the influence on the organic photoreceptor is small. In addition, this protective layer has a high hardness, and the film itself has a strong characteristic against an oxidizing atmosphere such as O _3, so that it has an excellent effect in improving the durability of the Se-based and organic-based photoconductors. Has been recognized.

However, even if such a material is used, if it is used repeatedly for a long time in the electrophotographic process, a copy or print image flows under an environment of high humidity or a rapid increase in humidity, so-called "image blur". It is becoming clear that there is still a problem of generating an abnormal image called an image.

The mechanism of the estimated image blur generation is roughly classified as follows: The photoreceptor surface is chemically degraded (oxidized, etc.) by the ozone and the like generated by the corona discharge due to repeated exposure to corona discharge used for charging and other purposes. Changes to hydrophilic.

Ozone and various ions by corona discharge react with impurities such as moisture and carbon dioxide in the air to form hydrophilic compounds containing nitrogen oxides, carboxyl groups, aldehyde groups, etc., which adhere to the photoreceptor surface, It changes to hydrophilic by being deposited.

In either case, an abnormal image is generated because the surface becomes hydrophilic and moisture is adsorbed on the surface of the photoreceptor to lower the resistance in the two-dimensional direction of the surface.

The silicon-based photoreceptor described above is considered to be the dominant cause. However, in the case of a photoreceptor having carbon or a high hardness protective layer containing carbon as a main component, fine irregularities (pitch 10
It is thought to be caused by the adhesion and deposition of hydrophilic substances in the concave part of random shape with no directivity in the axial and circumferential directions (0 to 5000 mm, depth about 50 to 2500 mm) .

As a method of preventing image deletion, (1) a method of heating a photoreceptor (JP-A-59-208558, JP-A-60-095467, JP-A-61-1329)
77, 62-262065 etc.) (2) Method of absorbing and decomposing corona products from corona discharger using activated carbon fiber, Ni, Pt, Au, beryllium alloy etc. for grid, shield case or charge wire (Japanese Unexamined Patent Publication No. 50-34828, 63
-311365, 64-68774, JP-A-1-210974, 1-3
19062), (3) Corona discharge current control method (Japanese Unexamined Patent Publication No. 1-2)
37569). However, these are all related to a charging method using a corona discharger that generates a large amount of ozone and ozone products.In the charging method using this corona discharge, the heating method is highly effective but still insufficient. Although the absorption and decomposition methods are effective, they still have problems with continuity.

In an image forming apparatus such as an electrophotographic apparatus, a corona charging device has been widely used as a means for charging or discharging the surface of a photoreceptor, which uniformly charges a photoreceptor or the like to a predetermined potential in a non-contact state. Although it is effective as a possible means, it has a problem that a high-voltage power supply is required and ozone and the like are generated by corona discharge, which adversely affects a photoreceptor and the like.

In contrast to such a corona charging device, a contact charging device that charges a charged member by applying a voltage to the surface of an image carrier such as a photoreceptor can be charged with a lower applied voltage than corona discharge. It has attracted attention because of its ability to reduce the amount of harmful substances such as ozone.
Specifically, the contact-type charging device generally applies a voltage to a conductive charging member such as a roller, and generally contacts the charging member with a surface to be charged such as a photoreceptor. In addition to the shape, a brush or blade shape is also used.For example, a conductive charging roller to which a voltage of 1 to 2 KV is applied is brought into contact with a photosensitive member or the like to rotate the photosensitive member surface.
It is charged to 0.5-1KV. This is because the voltage is lower than that of a corona charger that requires an applied voltage of several KV,
Since there is no ozone generated by useless shield current flowing through the shield or the like of the discharger, the total amount of ozone generated from the charging device can be reduced.

However, the charging mechanism of the contact charging device is basically based on the corona discharge phenomenon in the minute gap between the charging member and the surface of the photoreceptor, and the generation of harmful substances such as ozone due to the corona discharge. As a result, the deterioration of the characteristics of the charging member itself and the shortening of the life thereof are caused, causing poor charging. Also, as in the case of corona charging, ozone products or the like adhering or staying on or near the charging member surface are exposed to light. Various problems such as the occurrence of abnormal images such as image deletion and image bleeding due to deterioration of the characteristics of the surface of the image carrier such as the photoconductor at or near the contact portion of the charging member, gradually moving to the surface when the body stops, etc. These problems are more serious than the non-contact type corona charger in that the charging member is in contact with the photoreceptor or the like.

[Problems to be solved by the invention]

An object of the present invention is to solve the problems of harmful substances such as ozone generated at the time of charging, and to provide an electrophotographic method capable of stably maintaining a high quality image without generating an abnormal image for a long time. Another object of the present invention is to provide an electrophotographic method using a contact-type charging method which does not cause deterioration in characteristics of an image carrier such as a charging member and a photosensitive member even in long-term use.

[Means for solving the problem]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have a means for maintaining at least a concave portion of at least a concave portion of a protective layer having carbon or carbon as a main component and having fine irregularities on the surface at all times. It has been found that the electrophotographic method is effective for the above problem.

The present invention has been made based on these findings.

That is, according to the present invention, there is provided an electrophotographic photosensitive member having a configuration in which at least a photosensitive layer and a surface protective layer containing carbon or carbon as a main component and having fine irregularities on the surface are laminated in this order on a conductive support. In the photographic method, a solid wax-like nitrogen-containing compound at room temperature is used as a material for sealing at least the concave portion of the fine irregularities of the surface protective layer containing carbon or carbon as a main component, and the concave portion is always subjected to the sealing treatment. An electrophotographic method is provided, characterized in that the electrophotographic method is characterized in that the method is performed in the following manner.

In this case, a preferable method of sealing at least the concave portion of the fine uneven portion of the surface protective layer is to decompose ozone products and the like in the surface layer into fine unevenness of the surface protective layer containing carbon or carbon as a main component. By contacting or rubbing a charging member containing or containing a solid wax-like nitrogen-containing compound at room temperature, the wax-like nitrogen-containing compound is softened or liquefied,
This is a method of keeping the concave portion of the fine unevenness in a state where the concave portion is sealed with this material.

According to such a method, a hydrophilic substance such as an ozone product generated in a gap between the charging member and the photoreceptor surface is decomposed,
Prevents both the surface of the charging member and the surface of the photoconductor from degrading at the same time,
A stable image can be obtained for a long period of time without deteriorating the image quality.

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

FIG. 1 is a schematic cross-sectional view of an electrophotographic photoreceptor that has been subjected to a sealing treatment according to the present invention. The electrophotographic photoreceptor has a photosensitive layer (2) on a conductive support (1) and a carbon or carbon-based surface protective layer ( 3) and 3) show a state in which the concave portions of the fine irregularities are sealed with the waxy nitrogen compound (4).

In FIG. 1, the photosensitive layer 2 is of a single-layer type. However, the photosensitive layer 2 may be a laminated type including a charge generation layer and a charge transport layer, or may be provided between the conductive support (1) and the photosensitive layer (2) or in the photosensitive layer. It is needless to say that the present invention is also applicable to the case where an intermediate layer for improving the adhesion and other properties is provided between (2) and the surface protective layer (3).

As described above, a roller-type contact charging device described in JP-A-63-210864 is preferably used as a method for sealing the concave portions of the fine unevenness of the photoconductor surface protective layer.

Moreover, C ₁₉ or higher alkyl amine as a waxy nitrogen-containing compounds having an ozone decomposition, C ₁₃ or dialkylamine, C ₁₈ or more trialkyl amine, C ₁₀ or more di-amino alkane, C ₁₃ or more oxy alkane, C Those having a melting point of 50 ° C. or higher, such as a carbamate composed of ₁₆ or more cyclic imines, C ₅ or more fatty acid amide, C ₁₂ or more N-methyl fatty acid amide, and C ₁₂ or more alkyl group, are preferably used. .

An image forming operation in the electrophotographic method of the present invention will be described with reference to FIG. 2. Reference numeral 1 denotes a photosensitive drum which is driven to rotate around an axis 1e in a direction indicated by an arrow at a predetermined peripheral speed. The device 2 receives a negative or positive uniform charging process of a predetermined potential on its surface, and then receives an optical image L such as a slit exposure and a laser beam scanning exposure in the image exposure unit 3 to form an electrostatic latent image. The toner is developed by the developing device 4. This toner image is supplied to the paper feed roller 5
The transfer material which is transferred to the surface of the transfer material P conveyed synchronously with the drum peripheral speed by the transfer charger 6 and holds the toner image is separated from the drum surface by the separation charger 7 and fixed by the conveyance unit 8 (Not shown). On the other hand, the drum surface after the transfer of the toner image is cleaned by the cleaning device 9 and the charge is removed by the charge removing unit 10, and is subjected to the next cycle. Here, the contact charging device uses a metal core such as stainless steel as the shaft rod 22 and has an electric resistance of 10 ⁵
A roller 2 having a conductive elastic layer of about Ω · cm and a conductive urethane rubber coating 21 having higher surface accuracy and abrasion resistance on the outer surface thereof is pressed at a voltage of 0.01 to 0.2 kg / cm to apply a high voltage from a power source 23. It is applied to apply contact charge. This conductive roller is normally driven to rotate with the rotation of the photoconductor, but is positively driven to rotate at a predetermined speed in the forward or reverse direction with respect to the rotation direction of the photoconductor by another drive source, or is not driven. It is also possible to make pressure contact while rotating.

As described in JP-A-1-304473, the amount of ozone generated by such a contact-type charging method is reduced to several hundredths of the value of several tens of ppm of a normal corona charger. In the state (1), as described above, there is a problem that occurrence of image deletion or the like is inevitable at or near the contact portion with the charging member after the photosensitive member is stopped.

However, in the present invention, image deletion is prevented by utilizing the fine irregularities on the surface of the photoreceptor surface protective layer, and means for maintaining at least the concave portions of the fine irregularities on the surface protective layer at all times in a sealed state is provided. Therefore, the above-mentioned disadvantages are eliminated. As the pore-sealing method, as described above, a method of contacting or rubbing a contact charging device containing or holding an ozone product-decomposable waxy nitrogen-containing compound in a surface layer with the surface protective layer is preferable. In this case, these nitrogen-containing compounds are uniformly mixed with the material of the surface coating layer 21 of the contact charging roller 2, or a member (not shown) formed of these materials is pressed against the charging roller 2 to contact the surface coating layer 21. Is transferred to the fine concave portions of the photoreceptor surface protective layer.

As the conductive support used in the present invention, a conductor or an insulator subjected to a conductive treatment, for example, Al, Ni, Fe, C
In addition to metals such as u and Au or their alloys, thin films of metals such as Al, Ag and Au or conductive materials such as In ₂ O ₃ and SuO ₂ on insulating substrates such as polyester, polycarbonate, polyimide and glass And conductive-treated paper or the like can be used.

The shape of the conductive support is not particularly limited, and any of a plate shape, a drum shape, and a belt shape can be used.

An undercoat layer provided as needed between the conductive support and the photosensitive layer is provided for the purpose of improving adhesion between the photosensitive layer and the support or preventing interference of incident light, and the material is SiO, Al ₂
Inorganic materials such as O ₃ , silane coupling agent, titanium coupling agent, chromium coupling agent, etc., polyamide resin, alcohol-soluble polyamide resin, water-soluble polyvinyl butyral, polyvinyl butyral, binder resin with good adhesion such as PVA are used. Is done. In addition, those obtained by dispersing ZnO, TiO ₂ , ZnS, and the like in the resin having good adhesiveness can also be used. As a method for forming the undercoat layer, a method such as sputtering or vapor deposition is used when an inorganic material is used alone, and a usual coating method is used when an organic material is used. The heat of the underlayer is 5
μm or less is appropriate.

As the photosensitive layer provided directly or via an undercoat layer on the conductive support, any of an inorganic type and an organic type can be applied.

Examples of the inorganic photosensitive layer include Se or Se alloy (Se-T
e, Se-As, Se-As-Te etc) single-layer type or function-separated type photosensitive layer or amorphous silicon-based material (a-Si: H, a
-Si: C, H, a-Si: Ge, H etc.) and a single-layer type or function-separated type photosensitive layer.

As the organic photosensitive layer, either a single layer type or a function separated type can be applied.

Examples of the single-layer type photosensitive layer include dye-sensitized photoconductive powders such as zinc oxide, titanium oxide, and zinc sulfate, selenium powder, amorphous silicon powder, squaric salt pigment, phthalocyanine pigment, azulhenium salt. Pigments, azo pigments and the like, if necessary, coated with a binder resin and / or an electron-donating compound described below, or an eutectic complex formed from a pyrylium dye and a bisphenol A-based polycarbonate. Examples include a composition using a composition to which a donating compound is added. 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 (CG
L) and a charge transport layer (CTL) are exemplified.

As a charge generation layer (CGL) for generating and separating electrostatic charges by image exposure, an inorganic photoconductive powder such as crystalline selenium or arsenic selenide or an organic dye / pigment is dispersed or dissolved in a binder resin. Is used.

Examples of organic dyes and pigments as charge generating substances include, for example,
CI Pigment Blue 25 [Color Index (C
I) 21180], CI Pigment Red 41 (CI 2120)
0), CI Acid Red 52 (CI 45100), CI Basic Red 3 (CI 45210), phthalocyanine pigments having a polyfin skeleton, azulhenium salt pigments, squaric salt pigments, and azo pigments having a carbazole skeleton (JP-A-53 -95033), azo pigments having a styrylstilbene skeleton (described in JP-A-53-138229), azo pigments having a triphenylamine skeleton (described in JP-A-53-132547), dibenzo Azo pigments having a thiophene skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), and azo pigments having a fluorenone skeleton (described in JP-A-54-12742) 54-22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), and a distyryloxadiazole skeleton. Azo pigments (described in JP-A-54-2129) and azo pigments having a distyrylcarbazole skeleton (JP-A-54-17734)
And triazo pigments having a carbazole skeleton (described in JP-A-57-195767 and JP-A-57-195768), and CI Pigment Blue 16 (CI 741).
Phthalocyanine-based pigments such as 00), indigo-based pigments such as C-I Bad Brown 5 (CI73410), C-I-Dad Dye (CI 73030), Argo Scarlet B (manufactured by Bio Red), and Indus Scarlet R (manufactured by Bayer). Perylene pigments and the like can be used.

These charge generating substances may be 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.
It is suitable to use 00 parts by weight, preferably 0 to 50 parts by weight.

Examples of the binder resin used in combination with these organic pigments include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polycarbonate, and polyether, and polystyrene, polyacrylate, polymethacrylate, poly-N-vinylcarbazole, and polyvinyl butyral. , Styrene-butadiene copolymer, styrene-
Adhesive and insulating resins such as polymers and copolymers such as acrylonitrile copolymers are included.

The charge generating layer includes a charge generating substance, if necessary, together with a binder resin, tetrahydrolan, cyclohexanone,
It can be formed by dispersing with a ball mill, an attritor, a sand mill, or the like using a solvent such as dioxane or dichloroethane, diluting the dispersion appropriately, and applying. 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.

Further, in the present invention, when particles such as crystalline selenium or arsenic selenide alloy are used as the charge generating substance, an electron donating adhesive and / or an electron donating organic compound are used in combination. 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, and hydrazone. And nitrogen-containing compounds such as diarylmethane, α-phenylstilbene, and triphenylamine compounds, and diarylmethane compounds, and polyvinyl carbazole and its derivatives are particularly preferable. These substances can be used even if they are mixed. In this case, it is preferable to add another electron donating organic compound to polyvinyl carbazole and its derivative. The content of such an inorganic charge generating substance is suitably from 30 to 90% by weight of the whole layer. When using an inorganic charge generation material, the thickness of the charge generation layer is 0.2 to
5 μm is appropriate.

The charge transport layer (CTL) is a layer for retaining a charged charge and moving the charge generated and separated in the charge generation layer by exposure to combine with the held charged charge. 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, a charge transport layer can be formed by dissolving or dispersing the above substances in an appropriate 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, and oxazine. Azole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazolin, phenylhydrazones, α- Electron donating substances such as phenylstilbene derivatives;

Examples of the electron transporting material include chloranil, 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 thiophenone-4-one and 1,3,7-trinitrodibenzothiophenone-5,5-dioxide.

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

The binder resin used as needed includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. Polymer, 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 resin, silicone resin, epoxy Thermoplastic resins or thermosetting resins such as resins, melamine resins, urethane resins, phenolic resins, and alkyd resins.

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 general 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.

Further, in the present invention, the intermediate layer provided between the photosensitive layer and the surface protective layer as needed, SiO ₂ , an inorganic material such as Al ₂ O ₃ was provided by a method such as evaporation, sputtering, anodic oxidation and the like. And a polyamide resin (JP-A-58-30757 and JP-A-58-98739), an alcohol-soluble nylon resin (JP-A-60-196766), and a water-soluble polyvinyl butyral resin (JP-A-60-196766). Resin layer such as polyvinyl butyral resin (JP-A-58-106549) and polyvinyl alcohol.

In addition, a dispersion of pigment particles such as ZnO, TiO ₂ , and ZnS in the resin intermediate layer can also be used as the intermediate layer.

Further, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the intermediate layer of the present invention. The thickness of the intermediate layer is suitably from 0 to 5 μm.

In addition, an antioxidant or a light stabilizer may be added to at least one layer of the organic photosensitive layer or an optional intermediate layer for the purpose of improving the electrical characteristics of the photosensitive layer.

In the present invention, the protective layer provided on the outermost surface directly on the photosensitive layer or via the intermediate layer is made of carbon or carbon as a main component, and preferably has a CC bond similar to that of diamond having SP ³ orbitals. With a Vickers hardness of 100 to 3000 kg / cm ² and a specific resistance (specific resistance) of 1 × 10 ⁷ to 1 ×
It has a value of 10 ¹³ Ω · cm and has an optical energy bandwidth (Eg
Is more than 1.0 eV. It is formed of a thin film having a light-transmitting property in the infrared or visible region.

Such films are generally prepared by sputtering, plasma CV
D, formed by glow discharge decomposition method, photo-CVD method, etc., the film forming method is not particularly limited, plasma CV
A protective layer having good characteristics can be obtained by a method in which the film is formed with a sputtering effect while being the D method. Typical examples include the patent application “Composite Having Carbon Coating and Method for Producing the Same” (Japanese Patent Application No. 56-146929, filed on September 17, 1981, Japanese Patent Application Laid-Open No. 58-49609).

The thickness of the protective layer mainly composed of carbon or carbon is 10
It is from 0 ° to 10 µm, preferably from 1000 ° to 2 µm.

The surface of the protective layer composed mainly of carbon or carbon formed on these relatively low-temperature (up to 200 ° C.) substrates has fine irregularities (pitch 100 to 5000 mm, depth 50 to 2500 mm, Random irregularities without directivity in the direction) are observed.

Additives such as fluorine, halogen, nitrogen, phosphorus, and boron can be added to the protective layer containing carbon or carbon as a main component, if necessary, and its concentration is uniform in the depth direction of the film. Alternatively, a gradient may be provided. Further, the protective layer does not need to be a single layer, and may have a multilayer structure in which the presence or absence and type of additives are controlled.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

EXAMPLE As the photoreceptor in FIG. 2, an azo pigment having a fluorenone skeleton was used as a CGL on a basic drum made of Al, and was composed of phenylhydrolazone and a polycarbonate resin thereon.
A CTL was laminated, and a protective film of about 2000 mm similar to diamond was provided by a CVD method having a sputtering effect. Also, as the charging device 2, carbon black is dispersed around the stainless steel shaft bar 22 and coated with a nitrile rubber having an electric resistance of 6 × 10 ³ Ω · cm and polished, and then octacosylamine as a nitrogen-containing compound is coated on the surface together with the epoxy resin. It was dissolved in toluene, and a dispersion in which carbon black was dispersed was repeatedly applied by spraying three times to obtain a voltage resistance of 3 ×
A roller charger provided with a coating layer of 10 ⁶ Ω · cm was used.
While applying a voltage of -1.5 KV from the power supply 23 to this roller,
A method was adopted in which charging was performed while rubbing at a peripheral speed ratio of three times in the direction opposite to the photoreceptor. In order to compare the effects, a roller containing no octakosylamine in the coating layer (Comparative Example) was also prepared and subjected to a running test. As a result, in the comparative example, the image blur was generated at about 1300 sheets, but in the example, the image was not blurred even at 7000 sheets.

〔The invention's effect〕

Since the electrophotographic method of the present invention has the above configuration, it has the following functions and effects.

(1) The amount of generation of ozone product itself can be reduced to several hundredths by the contact charging method as compared with normal corona charging.

(2) Since the sealing material in the concave portion of the surface protective layer has the decomposability of ozone products, a small amount of ozone products generated is completely decomposed and does not accumulate at all.

(3) Since the charging member has the decomposability of ozone products,
Thus, the charging member is decomposed and the deterioration of the charging member itself can be prevented.

(4) The decomposable substance of the ozone product is softened or liquefied by a slight heat of contact or rubbing in the form of a wax, so that it is easy to seal the concave portion of the surface protective layer.

(5) The surface protection layer has a pitch of 100-5000mm and a depth of 50
Since it is extremely fine, that is, up to 2500 °, it is possible to apply a minute amount of a wax-like ozonolytic substance evenly and uniformly.

(6) The charging member and the photoreceptor (surface protective layer) are smoothly and uniformly adhered to each other so that the charging member is uniform and the charging efficiency is improved because the charging member and the photoreceptor (surface protective layer) are in close contact with each other.

For example, an extremely stable image can be obtained for a long period of time without deteriorating image quality.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an electrophotographic photosensitive member having been subjected to a sealing treatment used in the method of the present invention, and FIG. 2 is an explanatory view of an image forming process in the electrophotographic method of the present invention. (1) a conductive support, (2) a photosensitive layer, (3) a surface protective layer, and (4) a surface protective layer having been subjected to a sealing treatment.

Continuation of front page (56) References JP-A-2-132456 (JP, A) JP-A-3-291669 (JP, A) JP-A-1-280767 (JP, A) JP-A-63-220166 (JP) , A) JP-A-61-282846 (JP, A) JP-A-1-96660 (JP, A) JP-T-60-508831 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB Name) G03G 5/147 501

Claims (2)

(57) [Claims] 1. An electrophotographic method using an electrophotographic photosensitive member having a structure in which at least a photosensitive layer and a surface protective layer containing carbon or carbon as a main component and having fine irregularities on its surface are laminated in this order on a conductive support. A state in which a wax-like nitrogen-containing compound that is solid at room temperature is used as a material for sealing at least the concave portion of the fine irregularities of the surface protection layer containing carbon or carbon as a main component, and the concave portion is always sealed. An electrophotographic method characterized in that the method is maintained. 2. The means for sealing the recess is as follows:
2. The electrophotographic method according to claim 1, wherein a charging member containing or holding a waxy nitrogen-containing compound which is solid at room temperature is brought into contact with or rubbed against the charging member.