JP2001343778A - Electrophotographic photoreceptor, image forming method, image forming apparatus and process cartridge - Google Patents

Abstract

(57) [Problem] To provide an electrophotographic photoreceptor that generates a small amount of ozone and nitrogen oxides, can use low power, and can form images stably over a long period of time. An electrophotographic photosensitive member having a configuration in which at least a photosensitive layer and a surface protective layer are sequentially laminated on a conductive support, and a charging member arranged in contact with the electrophotographic photosensitive member,
In an image forming apparatus for injecting and charging the electrophotographic photosensitive member by applying a voltage to the charging member, the surface protective layer of the electrophotographic photosensitive member has a diamond-like carbon or amorphous carbon structure containing hydrogen. A photoreceptor for electrophotography, further comprising nitrogen and fluorine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photoreceptor,
The present invention relates to an image forming method, an image forming method, and a process cartridge.

[0002]

2. Description of the Related Art Generally, a corona charging method or a contact charging method has been used as a charging method in electrophotography. The corona charging method includes a corotron method and a scorotron method having a grid, in which a direct current or a superimposed direct current voltage is applied to a tungsten or nickel charge wire mounted in the center of a housing shielded by a metal plate. In this method, a corona discharge is caused to charge the photosensitive member. However, in this method, ozone, nitrogen oxide, and the like are generated because a high voltage is applied to the charge wire. This product is known to adversely affect not only the environmental aspects but also the photoreceptor on durability and image characteristics.

In recent years, instead of this method, a contact charging method has been put to practical use for the purpose of low ozone and low power. Contact charging method, ^{10 2} ~10 10 Ω · cm on the photoreceptor
This is a method in which a DC voltage in which DC or AC is superimposed is applied to a charging member having a certain level of resistance, and the photosensitive member is pressed against the photosensitive member to apply electric charge. Since this charging method is performed by discharging from the charging member to the member to be charged in accordance with Paschen's law, charging is started by applying a voltage higher than a certain threshold voltage. In this contact charging method, the voltage applied to the charging member is lower than that in the corona charging method, but a small amount of ozone and nitrogen oxides are generated due to the accompanying discharge.

For this reason, as a new charging method, a charging method by directly injecting electric charge to a photoreceptor has been disclosed in Japanese Patent Application Laid-Open No. H06-06605.
No. 003921. This charging method is a method in which a charge injection layer is provided on the surface of a photoreceptor, and a voltage is applied to a contact conductive member such as a charging roller, a charging brush, or a charging magnetic brush, and charge is injected to perform charging.
In this charging method, almost one-to-one charging can be performed with respect to an applied voltage with almost no discharge phenomenon. Therefore, compared to the conventional contact charging method, the amount of ozone and NOx generated is very small, It is an excellent charging method with low power.

[0005] The charge injection layer provided on the photoreceptor for performing the charge injection charging uses a resin in which a metal oxide such as tin oxide is dispersed in a resin. The charge injection layer composed of these metal oxides and resins tends to cause uneven charging on the surface of the photoreceptor due to uneven dispersion of the metal oxides. It was found that the durability was poor. As a means for improving the durability, there is a method devised by the present inventors to use a film having a hydrogen-containing diamond-like carbon or amorphous carbon structure as a charge injection layer.
However, it has been found that the charge injection layer has higher durability than the charge injection layer, but when used for a long period of time, the exposed portion potential increases.

[0006]

An object of the present invention is to provide an electrophotographic photoreceptor which generates a small amount of ozone and nitrogen oxides, can use low power, and can form images stably over a long period of time.
An object of the present invention is to provide an image forming method, an image forming method, and a process cartridge.

[0007]

SUMMARY OF THE INVENTION A first aspect of the present invention is to provide an electrophotographic photosensitive member having a structure in which at least a photosensitive layer and a surface protective layer are sequentially laminated on a conductive support, and a contact arrangement with the electrophotographic photosensitive member. In an image forming apparatus having a charging member to be charged and injecting and charging the electrophotographic photosensitive member by applying a voltage to the charging member, the surface protective layer of the electrophotographic photosensitive member includes:
An electrophotographic photoreceptor having a diamond-like carbon or amorphous carbon structure containing hydrogen and further containing nitrogen and fluorine. This electrophotographic photoreceptor is capable of good injection charging, suppresses an increase in the potential of an exposed portion in an actual machine, and improves image characteristics and abrasion resistance. More specifically, by including nitrogen and fluorine in the surface protective layer having a diamond-like carbon or amorphous carbon structure containing hydrogen, it is possible to reduce the increase in residual potential and to improve the electric charge such as good injection charging ability. The properties can be improved, and a surface protective layer having high translucency and high hardness can be formed.

[0008] A second aspect of the present invention is that the surface protective layer is formed of a film containing nitrogen and fluorine, and the content ratio of nitrogen to carbon (N / C ratio) is 0.05 or more;
And the atomic ratio of fluorine to carbon (F / C ratio)
Is 0.005 or more in the first electrophotographic photosensitive member. By defining the content ratio of nitrogen and fluorine to carbon as described above, it is possible to further improve the above-mentioned various characteristics.

The third aspect of the present invention is that the atomic ratio of nitrogen to carbon is larger in the vicinity of the outermost layer than in the vicinity of the photosensitive layer of the surface protective layer. On the photoreceptor.

A fourth aspect of the present invention is that the atomic ratio of fluorine to carbon is larger near the outermost surface layer than near the photosensitive layer of the surface protective layer. On the photoreceptor.

A fifth aspect of the present invention is the liquid crystal display device according to the first aspect, wherein the atomic ratio of nitrogen and fluorine to carbon is larger near the outermost surface layer than near the photosensitive layer of the surface protective layer.
To 4 for electrophotographic photoreceptors. As described above, since the atomic ratio of nitrogen and fluorine to carbon is larger near the outermost layer than near the photosensitive layer of the surface protective layer, the peeling resistance of the surface protective layer is improved. More specifically, the surface protective layer containing a large amount of nitrogen and fluorine is
Adhesion with the photosensitive layer becomes a problem. Therefore, when preparing the surface protective layer, first, a hydrogen-containing carbon film having a small or no content of nitrogen and fluorine is provided in the vicinity of the photosensitive layer to improve the adhesion of the surface protective layer. Next, a surface protective layer having a high content of nitrogen and fluorine is provided on this film. As a result, N ₂ , NH ₃ , C ₂ F ₆ , NF
₃₎ Prevention of damage to the photosensitive layer by an additive gas that can be an etching gas such as ₃ and reduction of contact resistance between the photosensitive layer and the surface protective layer. It is estimated that stable image formation can be performed.

A sixth aspect of the present invention is that the atomic ratio of nitrogen to carbon (N / C ratio) is 0.00 near the photosensitive layer.
5 or less and 0.05 or more near the outermost layer,
Further, the atomic ratio of fluorine to carbon (F / C ratio)
However, it is 0.001 or less near the photosensitive layer and 0.005 or more near the outermost layer in the fifth electrophotographic photosensitive member. As described above, by defining the content ratio of nitrogen and fluorine to carbon, the various characteristics can be further improved.

A seventh aspect of the present invention is that the surface protective layer further comprises a film containing at least one element selected from the group consisting of boron, phosphorus, chlorine, bromine and iodine, and further contains the element with respect to carbon. The first to sixth electrophotographic photoconductors are characterized in that the atomic weight ratio is larger near the outermost surface layer than near the photosensitive layer of the surface protective layer. As described above, the surface protection layer having a diamond-like carbon or amorphous carbon structure containing hydrogen contains an additive element such as boron, phosphorus, chlorine, bromine, and iodine to increase the residual potential. The electrical characteristics such as reduction and good chargeability can be improved, and a high-hardness surface protective layer with high translucency can be formed. However, the surface protective layer containing a large amount of the above-mentioned additive element has a problem of adhesion to the photosensitive layer.
Therefore, when producing the surface protective layer, first, a hydrogen-containing carbon film having a small or no content of the above-mentioned additive element is provided in the vicinity of the photosensitive layer to enhance the adhesiveness of the surface protective layer. Is provided with a surface protective layer having a large content of the additive element.

By adopting the above configuration,
B ₂ H ₆ , BCl ₃ , BBr, BF ₃ , P ₂ used in producing a surface protective layer having a large content of the above-mentioned additive element.
H _3, PF _3, PCl damage prevention and to ₃ such as a photosensitive layer by an additive gas can be a etching gas, due to a decrease in contact resistance of the photosensitive layer and the surface protective layer, peeling resistance of the protective layer of the photosensitive member Is expected to be improved, and long-term stable image formation can be performed.

An eighth aspect of the present invention is the electrophotographic photosensitive member according to any one of the first to seventh aspects, wherein the thickness of the surface protective layer of the electrophotographic photosensitive member is 0.5 to 5 μm. As mentioned above,
When the thickness of the surface protective layer is 0.5 to 5 μm, excellent scratch resistance can be obtained and image deletion can be suppressed.

A ninth aspect of the present invention is the electrophotographic photosensitive member according to any one of the first to eighth aspects, wherein the surface protective layer of the electrophotographic photosensitive member has a volume resistance in a range of 10 ⁹ to 10 ¹² Ω · cm. It is in. As described above, the volume resistance of the surface protective layer is 10 ⁹ to 10 ⁹
When it is in the range of 10 ¹² Ωcm, image injection is small and good injection charging is possible.

According to a tenth aspect of the present invention, there is provided the electrophotographic photosensitive member according to any one of the above items 1 to 9, wherein the Knoop hardness of the surface protective layer of the electrophotographic photosensitive member is 400 kg / mm ² or more. As described above, the Knoop hardness of the surface protective layer is
When it is 400 kg / mm ² or more, the wear resistance is improved.

According to an eleventh aspect of the present invention, there is provided an image forming method using an electrophotographic photosensitive member, wherein at least injection charging, image exposure, development, and transfer processes are repeated. An image forming method characterized by being a photoreceptor.

According to a twelfth aspect of the present invention, there is provided an image forming apparatus comprising at least an electrophotographic photosensitive member, an injection charging unit, an image exposing unit, a developing unit and a transfer unit. An image forming apparatus is an electrophotographic photosensitive member.

According to a thirteenth aspect of the present invention, there is provided an electrophotographic photosensitive member having an exposing means for exposing an image in accordance with image information, and wherein a surface protective layer of the electrophotographic photosensitive member has a wavelength of light of the exposing means. , Having a light transmittance of 50% or more.

A fourteenth aspect of the present invention is a process cartridge for an image forming apparatus comprising at least an electrophotographic photoreceptor, wherein the electrophotographic photoreceptor is one of the electrophotographic photoreceptors 1 to 10. In the process cartridge.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an example of an electrophotographic photoconductor according to the present invention, which has a configuration in which a photosensitive layer and a surface protective layer are provided on a conductive substrate. 2 and 3 show examples of the configuration of another electrophotographic photoreceptor of the present invention. FIG. 2 shows that the photosensitive layers are a charge generation layer (CGL) and a charge transport layer (CT).
L), and CGL and CTL of the conductive substrate and the photosensitive layer of the function separation type.
An undercoat layer is inserted between the layers. Incidentally, as long as it has at least a photosensitive layer and a surface protective layer on the conductive support,
The above-mentioned other layers and the type of the photosensitive layer may be arbitrarily combined.

In the present invention, the conductive support used for the electrophotographic photoreceptor may be a conductor or an insulator subjected to a conductive treatment, for example, a metal such as Al, Fe, Cu, Au, or an alloy thereof. , Polyester, polycarbonate, polyimide, glass, etc.
Those formed with a thin film of a metal such as l, Ag, Au or the like, or a conductive material such as In ₂ O ₃ or SnO _2, or paper subjected to a conductive treatment 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.

The undercoat layer provided between the conductive support and the photosensitive layer is used for the purpose of improving adhesiveness, preventing moiré, improving the coating property of the upper layer, and reducing residual potential. Is provided. The undercoat layer generally contains a resin as a main component. However, considering that the photosensitive layer is coated thereon using a solvent, the resin is a resin having high solubility resistance to a general organic solvent. Is desirable. As such a resin, polyvinyl alcohol, casein, a water-soluble resin such as sodium polyacrylate, a copolymerized nylon, an alcohol-soluble resin such as methoxymethylated nylon,
Curable resins that form a three-dimensional network structure, such as polyurethane, melamine resin, alkyd-melamine resin, epoxy resin, and the like. Further, a fine powder of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, or a metal sulfide or a metal nitride may be added. These undercoat layers can be formed using an appropriate solvent and a coating method. Further, as the undercoat layer of the present invention, a metal oxide layer formed by, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful. In addition to this, the undercoat layer of the present invention may be provided with Al ₂ O ₃ by anodic oxidation, organic substances such as polyparaxylylene (parylene), SnO ₂ , Ti
Those provided with an inorganic substance such as O ₂ , ITO, CeO ₂ by a vacuum thin film manufacturing method can also be used favorably. The thickness of the undercoat layer is 0.
1 to 5 μm is appropriate.

As the type of the photosensitive layer provided on the conductive support via the undercoat layer, any of Se type, OPC type and the like can be applied. In particular, environmental and inexpensive OPC are good. Of these, the OPC system will be briefly described below. The photosensitive layer in the present invention may be of a single layer type or a laminated type. Here, the laminated type will be described. First, the charge generation layer will be described. The charge generation layer is a layer containing a charge generation substance as a main component, and a binder resin may be used as needed. As the charge generation substance, an inorganic material and an organic material can be used.

Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound and the like. On the other hand, as the organic material, a known material can be used. For example, metal phthalocyanine, phthalocyanine pigments such as metal-free phthalocyanine, azulhenium salt pigment, methine squaric acid pigment, azo pigment having a carbazole skeleton, azo pigment having a triphenylamine skeleton, azo pigment having a diphenylamine skeleton, dibenzothiophene skeleton Azo pigment having a fluorenone skeleton, azo pigment having an oxadiazole skeleton, azo pigment having a bisstillene skeleton, azo pigment having a distyryl oxadiazole skeleton, azo pigment having a distyryl carbazole skeleton, perylene Pigments, anthraquinone or polycyclic quinone pigments, quinone imine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, Goido based pigments, and bisbenzimidazole pigments. These charge generating substances can be used alone or as a mixture of two or more kinds.

The binder resin used as needed in the charge generation layer includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, and polyvinyl formal. , Polyvinyl ketone, polystyrene, poly-N-vinyl carbazole, polyacrylamide, and the like. These binder resins can be used alone or as a mixture of two or more. Moreover, you may add a charge transport material as needed. Further, in addition to the binder resin described above, a polymer charge transport material is preferably used as the binder resin for the charge generation layer.

As a method for forming the charge generation layer, a vacuum thin film preparation method and a casting method from a solution dispersion system are mainly mentioned. The former method includes a vacuum deposition method, a glow discharge polymerization method, an ion plating method, a sputtering method,
Reactive sputtering, CVD, or the like is used, and the above-described inorganic and organic materials can be formed favorably. In addition, in order to provide a charge generation layer by a casting method described later, if necessary, the above-mentioned inorganic or organic charge generation substance is used together with a binder resin together with tetrahydrofuran,
It can be formed by dispersing using a solvent such as cyclohexanone, dioxane, dichloroethane, butanone or the like with a ball mill, an attritor, a sand mill or the like, diluting the dispersion liquid appropriately, and coating. 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 provided as described above is
About 0.01 to 5 μm is appropriate, and preferably about 0.0
5 to 2 μm.

The charge transporting layer is a layer intended to hold the charged charges and to move the charges generated and separated in the charge generating layer by exposure to combine with the charged charges held therein. High electrical resistance is required to achieve the purpose of retaining the charged charge, and in order to achieve the purpose of obtaining a high surface potential with the retained charged charge, the dielectric constant is small and the charge mobility is good. Is required. The charge transport layer for satisfying these requirements is composed of a charge transport material and a binder resin used as needed. The charge transport material and the binder resin can be formed by dissolving or dispersing in a suitable solvent, and then applying and drying the solution. If necessary, a plasticizer, an antioxidant, a leveling agent and the like can be added in an appropriate amount in addition to the charge transport material and the binder resin.

The charge transport material includes a hole transport material and an electron transport material. Examples of the electron transporting substance include chloranil, bromanil, tetracyanoethylene,
Tetracyanoquinodimethane, 2,4,7-trinitro-
9-fluorenone, 2,4,5,7-tetranitro-9
Fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,
Electron accepting substances such as 6,8-trinitro-4H-indeno [1,2-b] thiophene-4one and 1,3,7-trinitrodibenzothiophene-5,5-dioxide are exemplified. These electron transport materials can be used alone or
It can be used as a mixture of more than one species.

Examples of the hole transporting material include the following electron donating materials, which are preferably used. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9-
(P-diethylaminostyrylanthracene), 1,1
-Bis- (4-dibenzylaminophenyl) propane,
Styryl anthracene, styryl pyrazoline, phenylhydrazone, α-phenylstilbene derivative, thiazole derivative, triazole derivative, phenazine derivative,
Examples include acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. These hole transport materials can be used alone or as a mixture of two or more.

Further, the polymer charge transport layer material has the following structure. (A) Polymer having a carbazole ring For example, poly-N-vinylcarbazole,
No. 82056, JP-A-54-9632, JP-A-54-11737, JP-A-4-175337, JP-A-4-183719, JP-A-6-23
Compounds described in JP-A-4841 are exemplified. (B) Polymer having a hydrazone structure For example, JP-A-57-78402, JP-A-61-78402
JP-A-20953, JP-A-61-296358,
JP-A-1-134456, JP-A-1-17916
No. 4, JP-A-3-180851, JP-A-3-180851
180852, JP-A-3-50555, JP-A-5-310904, JP-A-6-234840
And the like. (C) Polysilylene polymer For example, JP-A-63-285552,
88461, JP-A-4-264130, JP-A-4-26
4131, JP-A-4-264132, JP-A-4-264
133 and the compounds described in JP-A-4-289867. (D) Polymer having a triarylamine structure For example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-134457, JP-A-2-282264, JP-A-2-282 304456
JP, JP-A-4-133065, JP-A-4-13-1
Compounds described in JP-A-33066, JP-A-5-40350, and JP-A-5-202135 are exemplified. (E) Other polymers For example, a formaldehyde condensation polymer of nitropyrene, JP-A-51-73888, JP-A-56-15074
9, JP-A-6-234836 and JP-A-6-34836.
Compounds described in JP-A-234837 are exemplified.

The polymer having an electron donating group used in the present invention includes not only the above-mentioned polymer but also a copolymer of a known monomer, a block polymer, a graft polymer, a star polymer, For example, it is also possible to use a crosslinked polymer having an electron donating group as disclosed in JP-A-3-109406. The following compounds are exemplified as polycarbonates, polyurethanes, polyesters, and polyethers having a triarylamine structure, which are more useful as the polymer charge transporting material used in the present invention. For example, Japanese Patent Application Laid-Open Nos. 64-1728, 64-13061 and 64-19049
JP, JP-A-4-11627, JP-A-4-22
5014, JP-A-4-230767, JP-A-4-320420, JP-A-5-232727, JP-A-7-56374, JP-A-9-127
713, JP-A-9-222740, JP-A-9-265197, JP-A-9-212877, JP-A-9-309495, and the like.

As the binder resin that can be used in combination with the charge transport layer, polycarbonate (bisphenol A type, bisphenol Z type), polyester, methacrylic resin, acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenolic resin, epoxy resin Polyurethane, polyvinylidene chloride, alkyd resin, silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl formal, polyacrylate, polyacrylamide, phenoxy resin and the like are used. These binders can be used alone or as a mixture of two or more. The thickness of the charge transport layer is suitably about 5 to 100 μm.

In the charge transport layer of the present invention, other antioxidants and plasticizers used for rubbers, plastics, oils and fats may be added. A leveling agent may be added to the charge transport layer. As the leveling agent, silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the chain measurement are used, and the amount used is based on 100 parts by weight of the binder resin. 0 to 1 part by weight is suitable.

Next, the case where the photosensitive layer has a single-layer structure will be described. When a single-layer photosensitive layer is provided by a casting method, it can be formed by dissolving or dispersing a charge generating substance and a low-molecular-weight or high-molecular charge-transporting substance in an appropriate solvent, and applying and drying the resultant. The materials described above can be used as the charge generating substance and the charge transporting substance. Also,
If necessary, a plasticizer can be added. Further, as a binder resin that can be used as needed,
In addition to using the binder resin described above for the charge transport layer as it is, the binder resin described for the charge generation layer may be mixed and used. The thickness of the single-layer photoreceptor is suitably about 5 to 100 μm.

In the present invention, a diamond containing hydrogen is used.
With a carbon-like or amorphous carbon structure
Nitrogen, fluorine, boron, phosphorus, chlorine, bromine and iodine
Contains at least one additive element selected from
Also, the atomic ratio of the additive element to carbon is increased
Higher near the outermost layer than near the photosensitive layer of the protective layer
It is composed of a hard thin film. The surface protective layer
Is preferably SP^ThreeSimilar to diamond with orbit
It is desirable to have a C—C bond. Note that SP ^TwoOrbit
A film with a structure similar to graphite with
In addition, amorphous materials may be used.

As described above, in the surface protective layer, the atomic ratio of nitrogen and fluorine to carbon is higher in the vicinity of the surface layer than in the vicinity of the photosensitive layer, and the atomic ratio of nitrogen to carbon (N / N) is higher. C ratio) in the vicinity of the photosensitive layer.
005 or less in the vicinity of the outermost layer and 0.05 or more, and furthermore, the atomic ratio of fluorine to carbon (F / C
Ratio) is 0.001 or less near the photosensitive layer and 0.005 or more near the outermost layer.
It is preferable that the volume resistance is 5 to 5 μm, the volume resistance is 10 ⁹ to 10 ¹² Ω · cm, and the Knoop hardness is 400 kg / mm ² or more.

The surface protective layer may have a multilayer structure in which the presence or absence, type, etc. of additives are controlled. As an example of this multilayer configuration, a first surface protection layer having a small content of an additive element and a second surface protection layer having a large content of the additive element as compared with the first surface protection layer are laminated. There is a two-layer configuration. Further, the layer configuration can be a multilayer configuration in which the film quality and the like are controlled. Further, the atomic ratio of the additive element contained in the surface protective layer to carbon may be larger in the vicinity of the outermost layer than in the vicinity of the photoreceptor. , It doesn't matter.

When forming the surface protective layer, a carrier gas such as H ₂ or Ar is used with a hydrocarbon gas (methane, ethane, ethylene, acetylene or the like) as a main material. Further, the gas for supplying the additive element may be any gas that can be vaporized under reduced pressure or a gas that can be vaporized by heating. For example, as a gas for supplying an additive element, NH ₃ , N ₂ , C ₂ F ₆ , CH ₃ F, NF ₃ , B ₂ H ₆ , B
Cl ₃ , BBr, BF ₃ , PH ₃ , PF ₃ , PCl ₃ or the like is used. It is formed by a plasma CVD method, a glow discharge decomposition method, an optical CVD method, or the like, or a sputtering method using graphite or the like as a target, using the above-described gas.
Although the method for forming the film is not particularly limited, as a method for forming a film containing carbon as a main component having good characteristics as a protective layer, the film is formed with a sputtering effect while being a plasma CVD method. Method (JP-A-58-496)
No. 09 gazette) and the like. In the method of forming a protective layer containing carbon as a main component using a plasma CVD method, it is not necessary to particularly heat the support, and a film can be formed at a low temperature of about 150 ° C. or less. There is an advantage that there is no problem when forming a protective layer on the layer.

Next, the charging method according to the present invention will be described. The charging method of the present invention is a contact charging method that does not involve a discharge phenomenon. That is, this is a charge injection charging method capable of charging the photoconductor at a potential corresponding to the voltage applied to the contact charging device. Since this method does not involve discharge, the generation of ozone and nitrogen oxides is small, and the applied voltage for charging the photoreceptor is even lower than that of the process using the conventional contact charging method, thus saving energy. . The photoreceptor used is provided with a surface protective layer having the function of a charge injection layer on the outermost layer described above. The charge injection layer plays the role of an electrode of a so-called capacitor. When a conductive contact charging member is brought into contact with this electrode and a voltage is applied, charges can be injected. Without such a charge injection layer, there is no electrode on the surface of the photoreceptor,
Insufficient charge injection is possible.

By providing the charge injection layer on the surface of the photosensitive layer, it is possible to form a uniform charge sheet on the surface of the photosensitive layer below the charge injection layer. The charge injection layer is required to have the property of quickly transferring the charge applied by the contact charging device to the surface layer of the photosensitive layer to form a uniform charge sheet. In order to form a uniform charge sheet, it is necessary for both the charge injection layer and the contact charging device to have uniform properties such as contact properties, nip, contact resistance, and volume specific resistance of the member, and these properties should be within a suitable range. Must be set.

As a contact charging method, there is a method example as shown in FIG. FIG. 4I shows a magnetic brush charging method, and FIG.
(II) is a (conductive) brush charging method, FIG. 4 (III) is a roller charging method using a conductive soft roller, FIG. 4 (IV) is a fixed (blade) charging method, FIG.
(V) is a belt type charging method using two rollers and a conductive belt. To charge the photoreceptor uniformly without discharging, secure the necessary nip with the photoreceptor at the appropriate applied voltage, reduce the gap between the photoreceptor and the charger as much as possible, and make the contact as dense as possible. There is a need. FIG.
In the magnetic brush charging method of (I), a magnetic roller formed by alternately arranging S and N pole magnets with a sleeve made of a non-magnetic material such as aluminum or bakelite is coated on a magnetic roller having a spherical shape or approximately 20-150 μm. Magnetic fine particles such as spherical ferrite, manganese oxide, and gamma ferric oxide, or fine particles coated with them for the purpose of improving the fluidity of polyester resin or fluororesin, protective layer, etc. to a thickness of about 1 to 5 mm. A suctioned and layered product is used. The resistance value of the fine particles is usually 1
It is in the range of 0 ⁵ to 10 ¹⁰ Ω · cm, and the lower the resistance, the better the charge injection property. By using a magnetic brush, it is also possible to form a cleaningless process.

In the conductive brush charging method shown in FIG. 4 (II), fibers such as rayon, acryl, polypropylene, polyester and polyacrylonitrile are conductively treated with carbon or copper sulfide, or zinc oxide, tin oxide or titanium oxide. Is spun with a fiber into which the conductive filler is kneaded, and further, a brush is formed using a member into which a metal thread is knitted. Further, carbon fibers or activated carbon fibers obtained by firing fibers in an inert gas atmosphere can also be used. The resistance of the member of the contact charging device is preferably in the range of 10 ² Ω · cm to ^{10 10} Ω · cm. Carbon fibers and activated carbon fibers can freely change the deposition resistivity at the firing temperature. 9 carbon components
If it exceeds 0%, the resistance becomes extremely low at about 10 ² Ω · cm. Therefore, when there is a pinhole in the photoconductor, there is a risk of discharge breakdown, but there is no problem when the photoconductor is used at a low voltage. Normally, a protection resistor of about 100 KΩ to 5 MΩ is used by being inserted in series between the power supply source.

The (soft) roller charging method of FIG. 4 (III) is suitable for increasing the nip with the photosensitive member and improving the adhesion to the photosensitive member. As a material of the soft roller, a soft rubber or a soft foam (urethane-based sponge, foam, or the like) is used, and the surface layer or the entire layer is subjected to a conductive treatment. As the conductive material, SnO ₂ or Ti
Examples include conductive fillers such as O ₂ , ZnO ₂ and carbon black, and conductive fibers such as carbon fiber and activated carbon fiber.

The charging method of the fixed type (blade type) shown in FIG. 4 (IV) is a method of charging the photoreceptor in such a manner as to rub it.
Most of the members described above can be used. As a configuration, for example, a finely woven carbon fiber or activated carbon fiber (produced by Unitika, Toho Rayon, Bethlon, or the like, or FW210 or 310 in the case of Toho Rayon) is used as a charging member on an elastic member such as a sponge or foam. Is charged in such a manner as to cover the photosensitive member.

The belt-type charging device shown in FIG. 4 (V) is a good means for gaining a nip with the photosensitive member. As a material that can be used, the members described in the conductive brush charging method and the roller charging method can be used. The nip required for contact with the photoreceptor is preferably as wide as possible, but it is usually required to be about 3 to 10 mm or more, and it is desirable to make uniform contact with the photoreceptor. When the various members described above are used as charging members, the volume resistivity is 10 ² to 10 ¹⁰ Ω ·
cm, preferably 10 ⁸ Ω · cm or less. The higher the resistance, the lower the charge injection property. If it is too low, there is no problem in charge injection properties, but if there is a pinhole in the photoreceptor, there is a risk of a power break or horizontal black streaks on the image. Normally, the charged position of the photoconductor is -500.
Since it is about -800 V, there is little danger to discharge breakdown, and even if ozone is generated, it is very small, so that its practical effect is small.

The photoreceptor of the present invention can be used in a general electrophotographic process including a charge injection charging method. Next, an electrophotographic process cartridge which is an example of the electrophotographic process of the present invention will be described. The process cartridge is
Units such as the charging unit, developing unit, and cleaning unit are of an integrated configuration.
It becomes simple. FIG. 5 shows an example of the electrophotographic process cartridge. The electrophotographic process of the present invention will be described along the description of the schematic sectional view.

In the drawing, reference numeral 11 denotes an electrophotographic photosensitive member of the present invention. First, the charging device 12 [the charging device in FIG. 4 (III) in the figure]
As a result, the photoconductor is injected and charged. After the photoreceptor is charged, it is subjected to image exposure 13, and charges are generated in the exposed portion to form an electrostatic latent image on the photoreceptor surface. After an electrostatic latent image is formed on the surface of the photoconductor, the electrostatic latent image is brought into contact with a developer via a developing roller 14 to form a toner image. The toner image formed on the surface of the photoconductor is transferred to a transfer member 15 such as paper by a transfer roller 16 and passes through a fixing unit 19 to form a hard copy. The residual toner on the electrophotographic photoreceptor 11 is removed by the cleaning unit 17 and the residual charge is removed by the charge removing lamp 18, and the process proceeds to the next electrophotographic cycle. The electrophotographic process using the present image forming method and the photoreceptor is not limited to the above-described example, and at least any process that forms an electrostatic latent image by charging and exposure can be used. It doesn't matter. In particular, in this image forming method, the cleaner-less method of improving the transfer efficiency of the toner and collecting the residual toner after the transfer by using a charging device or a developing device without using a cleaning unit is more mechanically required for the photosensitive member. This is desirable because the load is small.

[0050]

EXAMPLES The present invention will be described below with reference to examples, but the embodiments of the present invention are not limited thereto. All parts are by weight.

Example 1 An undercoat layer was formed on an Al support (outer diameter: 30 mmΦ) by dipping so that the film thickness after drying was about 4.0 μm. [Coating liquid for undercoat layer] Alkyd resin 6 parts Melamine resin 4 parts Titanium oxide 40 parts Methyl ethyl ketone 200 parts On this undercoat layer, dip coating was performed with a charge generation layer coating liquid containing a phthalocyanine pigment. After drying for a minute, a charge generation layer was formed.

[Coating Liquid for Charge Generating Layer] Oxo titanium phthalocyanine pigment 5 parts Polyvinyl butyral 2 parts Tetrahydrofuran 80 parts The charge generating layer is immersed in a coating liquid for a charge transport layer containing a low molecular charge transport material having the following structure. Coating, 120 ° C, 25
After drying for a minute, a charge transport layer was obtained.

[Coating solution for charge transport layer] Bisphenol A type polycarbonate 10 parts Low molecular charge transport material having the following structure 10 parts

Embedded image 100 parts of dichloromethane

The organic photosensitive layer produced in this way is shown in FIG.
To a plasma CVD apparatus as shown in FIG. 8 to form a surface protective layer. In FIG. 6, reference numeral 107 denotes a vacuum chamber of the plasma CVD apparatus, which is separated from a load / unload spare chamber 117 by a gate valve 109. The inside of the vacuum chamber 107 is evacuated by an exhaust system 120 (consisting of a pressure adjusting valve 121, a turbo molecular pump 122, and a rotary pump 123), and is kept at a constant pressure. A reaction tank is provided in the vacuum tank 107. As shown in FIGS. 7 and 8, the reaction tank 150 includes a frame-like structure 102 (having a square or hexagonal shape when viewed from the electrode side) and a hood 10 that covers the openings at both ends.
8, 118, and a pair of identically shaped first and second electrodes 103 disposed on the hoods 108, 118;
113 (using metal mesh such as aluminum)
It is composed of Reference numeral 130 denotes a gas line to be introduced into the reaction tank 150, to which various material gas containers are connected, which are introduced into the reaction tank 150 from the nozzles 125 via flow meters 129, respectively.

In the frame-like structure 102, the support 101 (101-1, 101-2,... 101) on which the photosensitive layer is formed is provided.
−n) are arranged as shown in FIGS. The above-mentioned respective supports are arranged as third electrodes as described later. A pair of power supplies 115 (115-115) for applying a first alternating voltage are respectively applied to the electrodes 103 and 113.
1, 115-2) are prepared. The frequency of the first alternating voltage is 1 to 100 MHz. These power supplies
They are connected to matching transformers 116-1 and 116-2, respectively. The phase in the matching transformer is adjusted by the phase adjuster 126 and can be supplied 180 ° or 0 ° from each other. That is, it has a symmetric or in-phase output. One end 104 and the other end 114 of the Matchons transformer
Are connected to the first and second electrodes 103 and 113, respectively. The output middle point 105 of the transformer is maintained at the ground level. Further, the midpoint 105 and the third electrode, that is, the support 101 (101-1, 101-2,...)
101-n) or holder 10 electrically connected thereto
2, a power supply 119 for applying the second alternating voltage is provided. The frequency of this second alternating voltage is 1 to
500 KHz. The output of the first alternating voltage applied to the first and second electrodes is 0.1 to 1 kW at a frequency of 13.56 MHz, and the second alternating voltage applied to the third electrode, ie, the support. Is about 100 W at a frequency of 150 KHz.

A surface protective layer was formed under the following conditions. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 5 sccm C ₂ F ₆ flow rate: 5 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −150 V Film thickness : 2.5 μm

Example 2 A film was prepared in the same manner as in Example 1 except that the thickness of the surface protective layer was 0.4 μm.

Example 3 The procedure of Example 3 was repeated except that the thickness of the surface protective layer was changed to 5.6 μm.

Example 4 A surface protective layer was prepared in the same manner as in Example 1 except that the conditions for forming the surface protective layer were as follows. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 50 sccm C ₂ F ₆ flow rate: 50 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −150 V Film thickness : 2.5 μm

Example 5 The same procedure was followed as in Example 1 except that the conditions for forming the surface protective layer were as follows. CH ₄ flow rate: 100 sccm H ₂ flow rate: 150 sccm N ₂ flow rate: 50 sccm C ₂ F ₆ flow rate: 50 sccm Reaction pressure: 0.01 torr First alternating voltage output: 150 W 13.56 MHz Bias voltage (DC component): −200 V : 2.5 μm

Example 6 A surface protective layer (hereinafter referred to as a first surface protective layer) was formed on the organic photosensitive layer under the following conditions, and the same surface protective layer as in Example 1 (hereinafter referred to as a second surface protective layer) was formed thereon. All were produced in the same manner as in Example 1 except that the sample was provided. (First surface protective layer forming conditions) CH ₄ flow rate: 100 sccm H ₂ flow rate: 100 sccm Reaction pressure: 0.02 Torr first alternating voltage output: 200 W 13.56 MHz bias voltage (DC component): -200 V thickness: 0 .2 μm

Example 7 Except that the first surface protective layer of Example 6 was provided, and the second surface protective layer was the surface protective layer of Example 2, the conditions for producing the surface protective layer of Example 6 were the same as those described below. Except for the above, all were manufactured in the same manner as in Example 1.

COMPARATIVE EXAMPLE 1 The procedure of Example 1 was repeated except that no surface protective layer was provided.

COMPARATIVE EXAMPLE 2 The same procedure as in Example 1 was carried out except that a 2.5 μm-thick charge injection layer mainly composed of SnO ₂ and a photocurable acrylic resin was provided instead of the surface protective layer.

Comparative Example 3 A surface protective layer was prepared in the same manner as in Example 1 except that the conditions for forming the surface protective layer were as follows. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -150 V Film thickness: 2.5 μm Was evaluated using an Imagio MF200 modified machine.

Comparative Example 4 A surface protective layer was produced in the same manner as in Example 1 except that the conditions for producing the surface protective layer were as follows. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 50 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -150 V Film thickness: 2.5 μm

Comparative Example 5 A surface protective layer was produced in the same manner as in Example 1 except that the conditions for producing the surface protective layer were as follows. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm C ₂ F ₆ flow rate: 50 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −150 V Film thickness: 2.5 μm MF200 remodeling machine: The charging unit was a fixed charging method shown in FIG. 4 (IV). (Charging member: FW210 manufactured by Toho Rayon, SP-8 manufactured by Inoac Corporation
0)

(Evaluation 1) The N / C ratio and the F / C ratio of the surface protective layers of Examples 1 to 5 and Comparative Examples 3 and 4 were investigated. The results are shown below. Example 1 N / C → 0.0112, F / C ratio → 0.0021 Example 2 Same as Example 1 Example 3 Same as Example 1 Example 4 N / C → 0.0623 F / C ratio → 0.0063 Example 5: N / C → 0.0652, F / C ratio → 0.0021 Comparative example 3: N / C → lower detection limit, F / C ratio → lower detection limit Comparative example 4: N / C → 0.0712, F / C ratio → below detection limit Comparative Example 5: N / C → below detection limit, F / C ratio → 0.0025

(Evaluation 2) The N / C ratio and the F / C ratio in the depth direction of the surface protective layers of Examples 1, 6, and 7 were examined. The results are shown below. Example 1 N / C ratio → <Outermost layer> 0.0103, <Near photosensitive layer> 0.0121 F / C ratio → <Outermost layer> 0.0021, <Near photosensitive layer> 0.0020 Example 6 N / C ratio → <Outermost layer> 0.0101, <Near photosensitive layer> 0.0012 F / C ratio → <Outermost layer> 0.0020, <Near photosensitive layer> 0.0002 Example 7 N / C ratio → <Top layer> 0.0681, <Near photosensitive layer> 0.0009 F / C ratio → <Top layer> 0.0061, <Near photosensitive layer> 0.0001

(Evaluation 3) The surface protective layers of Examples 6 and 7
Hardness (DUH201 manufactured by Shimadzu Corporation, load 5g
Weight) was measured. Example 6: 360 kg / mm^Two  Example 7: 421 kg / mm^Two

(Evaluation 4) The relationship between the voltage applied to the charger and the charging potential of the photosensitive member was examined using the photosensitive members of Examples 1, 4, 6, 7 and Comparative Example 1 and a modified Imagio MF200. FIG. 9 shows the evaluation results.

(Evaluation 5) Initially, image characteristics were examined using the photoconductors of Examples 1 to 3 and a modified Imagio MF200. (Charging potential: 600 V) Example 1: No problem in particular Example 2 ... No problem in particular Example 3: Image thickening occurred, and thin line reproducibility decreased.

(Evaluation 6) Using the photoreceptors of Examples 6 and 7 and Comparative Example 2 and an Imagio MF200 modified machine, 120,000 sheets (A
4) A paper passing test was performed. The amount of wear of the photoreceptor after passing the paper was examined. Example 1 0.75 μm Example 5 0.49 μm Comparative Example 2 1.78 μm

(Evaluation 7) Using the photoreceptors of Examples 1, 4, 6, 7 and Comparative Example 3 and a modified Imagio MF200 machine, a paper passing test of 90,000 sheets was performed. The amount of change in the potential of the exposed portion before and after passing the paper was adjusted. (△ VL = exposure portion potential after sheet passing−initial exposure portion potential) Example 1 -40V Example 4 -15V Example 6 -38V Example 7 -12V Comparative Example 3 -79V Comparative Example 4 ...- 65V Comparative Example 5 ...- 71V

(Evaluation 9) A 50,000-sheet (A4) paper passing test was performed using the photoconductors of Examples 1 to 3 and a modified Imagio MF200 machine. The appearance and image characteristics of the photoconductor after passing the paper were evaluated. Example 1 Several scratches were observed, but none of them reached the photosensitive layer and had no effect on the image. Example 2 Several scratches were confirmed, some of which reached the photosensitive layer, and abnormal images were generated. Example 3 Several scratches were observed, but none of them reached the photosensitive layer, and there was no abnormal image other than the initially thickened image.

(Evaluation 10) Using the photoreceptors of Examples 1 and 6 and an Imagio MF200 modified machine, a paper passing test of 150,000 sheets (A4) was conducted. As a result, the surface protective layer was peeled off around the end of the photosensitive drum and around the scratch portion in Example 1, and an abnormal image was generated. In the photoconductor of Example 10, no abnormal image due to peeling was observed.

(Evaluation 11) Using the photoreceptor of Example 6 and Comparative Example 2 and a modified Imagio MF200 machine, a predetermined halftone image was taken and evaluated. As compared with the photoconductor of Comparative Example 2,
The image using the photoreceptor of Example 1 had little image unevenness and roughness.

Example 8 An intermediate layer was formed on an Al support (outer diameter: 30 mmΦ) by dipping so that the film thickness after drying was about 4.0 μm. [Coating liquid for undercoat layer] Alkyd resin 6 parts (Beccosol 1307-60-EL: Dainippon Ink and Chemicals) Melamine resin 4 parts (Super Beckamine G-821-60: Dainippon Ink and Chemicals) Titanium oxide ( CR-EL: Ishihara Sangyo Co., Ltd.) 40 parts Methyl ethyl ketone 200 parts The undercoat layer was dip-coated with a charge generation layer coating solution containing a phthalocyanine pigment and dried at 70 ° C. for 10 minutes to form a charge generation layer.

[Coating Liquid for Charge Generating Layer] Oxotitanium phthalocyanine pigment 5 parts Polyvinyl butyral (XYHL: UCC) 2 parts Tetrahydrofuran 80 parts Immersion coating in the coating solution, at 120 ℃, 25
After drying for a minute, a charge transport layer was obtained.

[Coating solution for charge transport layer] Bisphenol A type polycarbonate 10 parts (Teijin: Panlite C1400) Low molecular charge transport material of the above formula 1 10 parts Tetrahydrofuran 100 parts The organic photosensitive layer thus produced is shown in FIG. 6 to 8 were set in a plasma CVD apparatus to form a surface protective layer.

The first surface protective layer was formed under the following conditions. C ₂ H ₄ flow rate: 100 sccm H ₂ flow rate: 5 sccm Reaction pressure: 0.01 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -200 V Film thickness: 0.1 μm

Under the following conditions, a second surface protective layer was formed on the first surface protective layer. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 50 sccm Reaction pressure: 0.05 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -150 V Film thickness: 2.4 μm XPS analysis in the depth direction of the protective layer revealed that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Example 9 The same procedure as in Example 8 was carried out except that the thickness of the second surface protective layer was set to 0.2 μm.

Example 10 The same procedure as in Example 8 was carried out except that the thickness of the surface protective layer was changed to 5.7 μm.

Example 11 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 100 sccm Reaction pressure: 0.03 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −150 V Film thickness: 2.4 μm XPS analysis in the depth direction of the protective layer revealed that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Example 12 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. CH ₄ flow rate: 100 sccm H ₂ flow rate: 200 sccm N ₂ flow rate: 10 sccm Reaction pressure: 0.01 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −180 V Film thickness: 2.4 μm XPS analysis in the depth direction of the protective layer revealed that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Example 13 The same procedure as in Example 8 was carried out except that the conditions for forming the surface protective layer were as follows. (First surface protective layer) C ₂ H ₄ flow rate: 100 sccm H ₂ flow rate: 30 sccm Reaction pressure: 0.02 Torr first alternating voltage output: 100W 13.56 MHz bias voltage (DC component): -200 V thickness: 0. 2 μm

(Second Surface Protective Layer) CH ₄ Flow Rate : 100 sccm H ₂ flow rate: 50 sccm C ₂ F ₆ flow rate: 100 sccm Reaction pressure: 0.01 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -200 V Film thickness: 2.6 μm As a result of XPS analysis in the depth direction of the layer, it was found that the fluorine content near the surface layer was higher than that near the photosensitive layer.

Example 14 A second surface protective layer was manufactured in the same manner as in Example 8, except that the following conditions were used. C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate: 200 sccm B ₂ H ₄ flow rate: 40 sccm Reaction pressure: 0.02 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −200 V Film thickness: 2. XPS analysis was performed in the depth direction of the produced surface protective layer of 5 μm. As a result, it was found that the boron content near the surface layer was higher than that near the photosensitive layer.

Example 15 A surface protective layer was prepared in the same manner as in Example 8 except that the conditions for forming the surface protective layer were as follows. (First surface protective layer) CH ₄ flow rate: 100 sccm H ₂ flow rate: 30 sccm Reaction pressure: 0.02 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −200 V Film thickness: 0.2 μm

(Second surface protective layer) C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate : 150 sccm PH ₃ flow rate: 45 sccm Reaction pressure: 0.02 torr First alternating voltage output: 100W 13.56MHz Bias voltage (DC component): -150V Film thickness: 2.5μm XPS in the depth direction of the produced surface protective layer As a result of analysis, it was found that the phosphorus content near the surface layer was higher than that near the photosensitive layer.

Example 16 A second surface protective layer was manufactured in the same manner as in Example 8, except that the following conditions were used. C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate: 200 sccm CH ₃ Cl flow rate: 50 sccm Reaction pressure: 0.01 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -150 V Film thickness: 2.5 μm As a result of performing XPS analysis in the depth direction of the produced surface protective layer, it was found that the chlorine content near the surface layer was higher than that near the photosensitive layer.

Example 17 A second surface protective layer was manufactured in the same manner as in Example 8, except that the following conditions were used. C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate: 200 sccm CH ₃ Br flow rate: 30 sccm Reaction pressure: 0.02 torr First alternating voltage output: 100 13.56 MHz Bias voltage (DC component): -150 V Film thickness: 2.5 μm XPS analysis of the produced surface protective layer in the depth direction revealed that the bromine content near the surface layer was higher than that near the photosensitive layer.

Example 18 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate: 220 sccm CH ₃ I flow rate: 40 sccm Reaction pressure: 0.02 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −150 V Film thickness: 2.5 μm XPS analysis in the depth direction of the produced surface protective layer revealed that the iodine content near the surface layer was higher than that near the photosensitive layer.

Example 19 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. CH ₄ flow rate: 120 sccm H ₂ flow rate: 200 sccm C ₂ F ₆ flow rate: ₆₀ sccm Reaction pressure: 0.03 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): −200 V Film thickness: 3.0 μm As a result of XPS analysis in the depth direction of the surface protective layer, it was found that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Example 20 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. CH ₄ flow rate: 120 sccm H ₂ flow rate: 100 sccm C ₂ F ₆ flow rate: ₆₀ sccm Reaction pressure: 0.02 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -200 V Film thickness: 2.9 μm As a result of XPS analysis in the depth direction of the surface protective layer, it was found that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Example 21 A second surface protective layer was produced in the same manner as in Example 8, except that the following conditions were used. CH ₄ flow rate: 100 sccm H ₂ flow rate: 15 sccm C ₂ F ₆ flow rate: ₆₀ sccm Reaction pressure: 0.01 torr First alternating voltage output: 100 W 13.56 MHz Bias voltage (DC component): -250 V Film thickness: 3.5 μm As a result of XPS analysis in the depth direction of the surface protective layer, it was found that the nitrogen content near the surface layer was higher than that near the photosensitive layer.

Comparative Example 6 The procedure of Example 8 was repeated except that no surface protective layer was provided.

Comparative Example 7 The procedure of Example 8 was repeated except that a 2.5 μm-thick charge injection layer mainly composed of SnO ₂ and a photocurable acrylic resin was provided instead of the surface protective layer.

Comparative Example 8 The same procedure as in Example 8 was carried out except that the second surface protective layer of Example 8 was not provided, and the surface protective layer having a thickness of 2.37 μm was provided under the conditions for forming the first surface protective layer. It was fabricated and evaluated in the same manner. The results are shown in FIG.

COMPARATIVE EXAMPLE 9 The same procedure as in Example 8 was carried out except that the first surface protective layer of Example 8 was not provided, and the surface protective layer having a thickness of 2.37 μm was provided under the conditions for forming the second surface protective layer. It was fabricated and evaluated in the same manner. The results are shown in FIG. The photoreceptor manufactured as described above was evaluated using an Imagio DA355 modified machine. Imagio DA355 remodeling machine: The charging unit was a fixed charging method shown in FIG. 4 (IV). (Charging member: FW210 manufactured by Toho Rayon, SP-8 manufactured by Inoac Corporation
0)

(Evaluation 12) Surfaces of Examples 8, 11 and 12
Measure volume resistance (500VDC, 1 minute value) of protective layer
did. The results are shown below. Example 1 3.4 × 10^TenΩ · cm^Two  Example 4 5.2 × 10⁷Ω · cm^Two  Example 5 4.3 × 10¹²Ω · cm^Two

(Evaluation 13) Using the photosensitive members of Examples 8, 11, 12 and Comparative Example 6 and a modified Imagio DA355 machine, the relationship between the voltage applied to the charger and the charging potential of the photosensitive member was examined. FIG. 10 shows the evaluation results.

(Evaluation 14) Initially, image characteristics were examined using the photoconductors of Examples 8 to 12 and a modified Imagio DA355 machine. (Charging potential: 600 V) Example 8: No problem in particular Example 9: No problem in particular Example 10: Image thickening occurred, and thin line reproducibility decreased. Example 11 Image deletion occurred. Example 12: No problem

(Evaluation 15) Surfaces of Examples 8, 11 and 12
Knoop hardness of protective layer (DUH201 manufactured by Shimadzu Corporation, load
(5 g load). Example 8 350 kg / mm^Two  Example 11: 415 kg / mm^Two  Example 12: 520 kg / mm^Two

(Evaluation 16) Using the photoconductors of Examples 8, 11, 12 and Comparative Example 7 and a modified Imagio DA355 machine,
A paper passing test of 100,000 sheets (A4) was conducted. The amount of wear of the photoreceptor after passing the paper was examined. Example 8: 0.81 μm Example 11: 0.43 μm Example 12: 0.40 μm Comparative Example 7: 2.01 μm

(Evaluation 17) A 200,000-sheet (A4) paper passing test was performed using the photoconductors of Examples 8 to 10 and an Imagio DA355 modified machine. The appearance and image characteristics of the photoconductor after passing the paper were evaluated. Example 8: Several scratches were observed, but none of them reached the photosensitive layer and had no effect on the image. Example 9: Several scratches were observed, some of which reached the photosensitive layer, and an abnormal image occurred. Example 3 Several scratches were confirmed, but none of them reached the photosensitive layer, and there was no abnormal image other than the initially thickened image.

(Evaluation 18) Using the photoreceptors of Examples 8, 13 to 18 and Comparative Examples 8 and 9 and a modified Imagio DA355 machine, a paper passing test of 250,000 sheets (A4) was performed. The amount of change in the exposed portion potential before and after paper passing was investigated. (ΔVL = exposure portion potential after sheet passing−initial exposure portion potential) Example 8 -20 V Example 13 -19 V Example 14 -21 V Example 15 -17 V Example 16 -15 V Example 17 ... -19V Example 18 ... -22V Comparative Example 8 ... -65V Comparative Example 9 ... -23V

(Evaluation 19) Using the photoconductors of Examples 8, 13 to 18 and Comparative Examples 8 and 9 and a modified Imagio DA355 machine, a paper passing test of 320,000 sheets (A4) was performed. The appearance and image evaluation of the surface layer after passing the paper were performed. Examples 8, 13, 14,
Regarding 15, 16, 17, 18 and Comparative Example 8, some scratches were confirmed, but no abnormal image was seen. On the other hand, in the photoreceptor of Comparative Example 4, peeling of the surface layer was confirmed from the end of the photoreceptor and the scratch portion, and an abnormal image corresponding thereto was observed.

(Evaluation 20) The light transmittance (780 nm) of the surface protective layers of Examples 19 to 21 was measured. Example 18 ... 43% Example 19 ... 53% Example 20 ... 79%

(Evaluation 21) Using the photoreceptors of Examples 19 to 21 and an Imagio DA355 modified machine, a wavelength of 780 nm was used.
The potential of the exposed portion when light having an irradiation energy of 5.0 erg / cm ² was used was examined. Example 18 ... -320 V Example 19 ... -140 V Example 20 ... -130 V

(Evaluation 22) Using the photoconductors of Example 8 and Comparative Example 7 and an Imagio DA355 modified machine, a predetermined halftone image was taken and evaluated. As compared with the photoconductor of Comparative Example 7,
The image using the photoreceptor of Example 8 had little image unevenness and roughness.

[0113]

According to the present invention, since the above-described configuration is employed, the following remarkable effects can be obtained. 1. The present invention provides an electrophotographic photoreceptor capable of performing good injection charging, suppressing an increase in the potential of an exposed portion in an actual machine, and improving image characteristics and abrasion resistance. 2. (2) An electrophotographic photoconductor in which the above-mentioned various characteristics of the invention of (1) is further improved is provided. 3. Claims 3 to 6 Provide an electrophotographic photoconductor in which the surface protective layer has improved peel resistance. 4. Claim 7: An improvement in electrical characteristics such as a decrease in residual potential, good charging ability, and the like, a high light-transmitting and high hardness surface protective layer can be formed, and further, adhesion to a photosensitive layer can be improved. A problem-free electrophotographic photoconductor is provided. 5. Claims 8 to 9 Provide an electrophotographic photoreceptor which is excellent in scratch resistance and hardly causes image deletion. 6. Claim 10 An electrophotographic photoreceptor having improved abrasion resistance is provided. 7. Claims 11 to 13 A process cartridge or an image forming apparatus having the above-mentioned various characteristics is provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a layer configuration of an electrophotographic photoconductor according to the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photoreceptor according to the present invention.

FIG. 3 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member according to the present invention.

FIG. 4 is a schematic sectional view showing an example of a charge injection type contact charging device according to the present invention. (I) Magnetic brush charging method (II) (Conductivity) brush charging method (III) Roller charging method using conductive soft roller (IV) Fixed (blade) charging method (V) Two rollers -Type charging method using a conductive belt with a belt

FIG. 5 is a schematic sectional view showing an example of the electrophotographic process cartridge according to the present invention.

FIG. 6 is an explanatory view of one specific example of a plasma CVD apparatus used for forming a protective layer having a diamond-like carbon or amorphous carbon structure containing hydrogen.

FIG. 7 is a plan view of a frame structure 102 of the plasma CVD apparatus.

FIG. 8 is a plan view of another frame-shaped structure 102 of the plasma CVD apparatus.

FIG. 9 is a diagram showing the results of the relationship between the applied voltage of the charger and the charging potential of the photoreceptor in Examples 1, 4, 6, and 7 and Comparative Example 1 using a modified Imagio MF200 machine.

FIG. 10 is a diagram illustrating the results of the relationship between the applied voltage of the charger and the charging potential of the photoconductor of Examples 8, 11, and 12 and Comparative Example 6 using a modified Imagio DA355 machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Electrophotographic photoreceptor 12 Charging device 13 Image exposure 14 Developing roller 15 Transfer member 16 Transfer roller 17 Cleaning unit 18 Static elimination lamp 19 Fixing unit 101-1 to 101-n Support 102 Frame-shaped structure 103, 113 Electrode 104 114 End of matching transformer 105 ... Transformer output midpoint 107 Vacuum tank 108, 118 Hood 109 Gate valve 114 End of matching transformer 115 Power supply 116-1, 116-2 Matching transformer 117 Load / unload spare room 119 Power supply Reference Signs List 120 exhaust system 121 adjustment valve 122 turbo molecular pump 123 rotary pump 125 gas introduction nozzle 126 phase adjuster 129 flow meter 130 to 134 gas line 140 alternating power supply system 150 reaction tank

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiko Tokumasu 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Masahiko Akato 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Sou Kai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Hiroshi Nagame 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Company, Ltd. (72) Inventor Tetsuro Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2H068 AA02 AA08 AA09 CA01 CA03 CA60 FA01 FC01

Claims (14)

[Claims] An electrophotographic photosensitive member having a structure in which at least a photosensitive layer and a surface protective layer are sequentially laminated on a conductive support, and a charging member arranged in contact with the electrophotographic photosensitive member,
In an image forming apparatus for injecting and charging the electrophotographic photosensitive member by applying a voltage to the charging member, the surface protective layer of the electrophotographic photosensitive member has a diamond-like carbon or amorphous carbon structure containing hydrogen. And an electrophotographic photoreceptor further comprising nitrogen and fluorine. 2. A surface protective layer comprising a film containing nitrogen and fluorine, wherein the atomic ratio of nitrogen to carbon (N / C ratio) is 0.05 or more, and the atomic weight of fluorine to carbon. 2. The electrophotographic photoconductor according to claim 1, wherein the ratio (F / C ratio) is 0.005 or more. 3. The electrophotographic photoconductor according to claim 1, wherein the atomic ratio of nitrogen to carbon is larger near the outermost surface layer than near the photosensitive layer of the surface protective layer. 4. The content atomic ratio of fluorine to carbon is as follows:
The electrophotographic photoconductor according to any one of claims 1 to 3, wherein the surface protective layer is larger near the outermost layer than near the photosensitive layer. 5. The electron according to claim 1, wherein the atomic ratio of nitrogen and fluorine to carbon is larger near the outermost surface layer than near the photosensitive layer of the surface protective layer. Photoreceptor. 6. An atomic ratio (N / N) of nitrogen to carbon.
C ratio) is 0.005 or less near the photosensitive layer and 0.05 or more near the outermost layer, and the atomic ratio of fluorine to carbon (F / C ratio) is 0 near the photosensitive layer. 0.001 or less and 0.00 near the outermost layer.
6. The electrophotographic photosensitive member according to claim 5, wherein the number is at least 005. 7. The surface protective layer further comprises boron, phosphorus, chlorine,
A film containing at least one element selected from the group consisting of bromine and iodine, and the atomic ratio of the element to carbon is larger near the outermost layer than near the photosensitive layer of the surface protective layer. 7. The method according to claim 1, wherein
The electrophotographic photosensitive member according to any one of the above. 8. The electrophotographic photoreceptor according to claim 1, wherein the surface protective layer has a thickness of 0.5 to 5 μm. 9. The volume resistance of the surface protective layer is from 10 ⁹ to 10
9. The method according to claim 1, wherein the resistance is in a range of ¹² Ω · cm.
The electrophotographic photosensitive member according to any one of the above. 10. The Knoop hardness of the surface protective layer is 400 k.
The electrophotographic photoreceptor according to claim 1, wherein the g / mm ^{2 is not} less than g / mm ² . 11. An electrophotographic photoreceptor according to claim 1, wherein said electrophotographic photoreceptor is an image forming method in which at least injection charging, image exposure, development, and transfer processes are repeated. An image forming method, which is a photographic photoreceptor. 12. An image forming apparatus comprising at least an electrophotographic photosensitive member, an injection charging unit, an image exposing unit, a developing unit and a transferring unit, wherein the electrophotographic photosensitive member is according to any one of claims 1 to 10. An image forming apparatus comprising: an electrophotographic photoreceptor; 13. An electrophotographic photoreceptor having an exposing means for exposing an image in accordance with image information, and wherein a surface protective layer of the electrophotographic photoreceptor has 50% or more of a wavelength of light of the exposing means. The image forming apparatus according to claim 12, wherein the image forming apparatus has a light transmittance. 14. A process cartridge for an image forming apparatus comprising at least an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. Characteristic process cartridge.