JPH07140694A - Electrophotographic photoconductor - Google Patents

Abstract

(57) [Summary] [Object] To provide a long-life electrophotographic photoreceptor in which a hard protective layer is laminated on an organic photosensitive layer. [Structure] In an electrophotographic photosensitive member having a structure in which an organic photosensitive layer 2, a first surface protective layer 3, and a second surface protective layer 4 are sequentially laminated on a conductive support 1, the first surface protective layer 3 is made of carbon. Is the main component, and other than that, only hydrogen, oxygen, and nitrogen are contained, and the ratio of the atomic weight of nitrogen and carbon (N / C) is 0 <N /
An electrophotographic photosensitive member made of a film having C ≦ 0.005, and the second surface protective layer 4 made of a film containing at least carbon, a metal element (for example, tin) oxygen, and hydrogen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor having a surface protective layer on the photosensitive layer.

[0002]

2. Description of the Related Art Conventionally, as a photoconductor used in an electrophotographic system, a photoconductive material having selenium or a selenium alloy as a main component is provided on a conductive support, or an inorganic material such as zinc oxide or cadmium sulfide. Generally, a photoconductive material dispersed in a binder, an organic photoconductive material such as poly-N-vinylcarbazole and trinitrofluorenone or an azo pigment, and an amorphous silicon-based material are used. Are known. By the way, generally, the "electrophotographic system" is an electrostatic latent image in which a photoconductive photoconductor is first charged in a dark place by, for example, corona discharge, and then imagewise exposed to selectively dissipate the charge only in the exposed part. Image forming method in which the latent image part is developed with a detection fine particle (toner) composed of a colorant such as a dye or a pigment and a binder such as a polymer substance and visualized to form an image. one of.

The basic characteristics required for a photosensitive member in such an electrophotographic method are: (1) Being capable of being charged to an appropriate potential in a dark place. (2) The dissipation of electric charges is small in the dark. (3) Charges can be rapidly dissipated by light irradiation. And so on.

In recent years, as the speed and size of electrophotographic copying machines have increased, the reliability of the photosensitive member has been strongly required to maintain high image quality even after repeated use over a long period, in addition to the above characteristics. ing. In the copying machine, there are roughly two main causes of impairing the life of the photoconductor in the copying machine. One of them is caused by the mechanical stress received from the developing process, the cleaning process, and the copy paper. One is due to abrasion and scratch, and the other is due to chemical damage caused by corona discharge which is received during charging, transfer and separation processes.
As the former method of preventing abrasion of the photoconductor, a technique of providing a protective layer on the photoconductor surface is known.

For example, a method of providing an organic film on the surface of the photosensitive layer (Japanese Patent Publication No. 38-15466), a method of providing an inorganic oxide (Japanese Patent Publication No. 43-14517), a method of laminating an insulating layer after providing an adhesive layer ( Japanese Patent Publication 43-2759
1), or a-Si layer, a-Si: N: H layer, a-Si: O: H by plasma CVD method, photo CVD method, or the like.
A method of laminating layers and the like (JP-A-57-179859 and JP-A-59-58437) is disclosed. Further, in recent years, a high hardness film (a-) containing carbon or carbon as a main component, which is obtained by a method such as a plasma CVD method, an optical CVD method, or a sputtering method
The application of C: H film, amorphous carbon film, amorphous carbon film, diamond-like carbon film, etc.) to the photoreceptor protective layer is becoming active.

For example, a protective layer made of amorphous carbon or hard carbon is provided on the surface of a photosensitive layer (JP-A-60-249).
155), a diamond-like carbon protective layer provided on the outermost surface (JP-A-61-255352), and a high-hardness insulating layer containing carbon as a main component on the photosensitive layer (JP-A-61-264355). Alternatively, a protective layer comprising an amorphous hydrocarbon film formed by glow discharge containing at least nitrogen atoms, oxygen atoms, halogen atoms, alkali metal atoms and the like is provided on the organic photosensitive layer (Japanese Patent Laid-Open No. 63-
220166-9) etc. can be mentioned. By these methods, it has become possible to obtain a photoreceptor having excellent abrasion resistance with greatly improved surface hardness. However, carbon or a high hardness film containing carbon as a main component has a drawback that it has a light absorption in a short wavelength to a visible wavelength and the applied photoconductor is limited to a long wavelength one.

Therefore, the present inventor has improved the photosensitive material to be applied, which has mechanical durability equivalent to that of carbon or a protective layer containing carbon as a main component and has a good transmittance even in a visible wavelength region. As a protective layer, a plasma CVD thin film protective layer composed of Sn, C, O, H (Japanese Patent Laid-Open No. 63-26).
4766) and a volatile metal-containing compound or a mixed gas of a volatile metal-containing compound and a volatile organic compound as a starting material, the protective layer comprising a film deposited by a glow discharge decomposition method (JP-A-2-50166). Applied for.
The protective layer of the present invention is very excellent in optical and mechanical properties, but when tested after that, when it is used for a long time (100,000 sheets or more), the protective layer is locally and It has been found that there is a problem that the protective layer peels off from the photosensitive layer due to long-term mechanical stress. Therefore, the present inventor further, as a method of suppressing the change with time of the adhesiveness between the protective layer and the photosensitive layer, contains carbon as a main component between the protective layer and the photosensitive layer, and additionally contains only hydrogen and oxygen. An application for an electrophotographic photoreceptor having a structure in which a film is inserted as a first surface protective layer is filed. This allows for a long period (10
The problem that the protective layer peels off from the photosensitive layer even after it has been used (more than 100,000 sheets) has been solved, but there is a rise in the potential of the exposed portion of the photosensitive member when used for a long time (more than 100,000 sheets), and the ultra-high durability photoreceptor It was found that there is room for further improvement.

[0008]

The present invention has been made to solve these problems, and its purpose is to provide a volatile metal-containing compound formed on an organic photosensitive layer, or a volatile metal-containing compound. A protective layer consisting of a film deposited by glow discharge decomposition using a mixed gas of the metal-containing compound and a volatile organic compound as a starting material, and at least Sn, C, O,
In an electrophotographic photoreceptor having a structure in which a plasma CVD thin film protective layer composed of H is laminated, it is possible to improve the peeling resistance of the protective layer and perform stable image formation for a long period of time. To provide the body.

[0009]

As a result of extensive studies to solve the above problems, as a structure in which at least an organic photosensitive layer, a first surface protective layer, and a second surface protective layer are sequentially laminated on a conductive support. , The first surface protection layer is mainly composed of carbon,
Other than that, it contains only hydrogen, oxygen, and nitrogen, and the ratio of the atomic weight of nitrogen and carbon (N / C) is 0 <N / C ≦ 0.005.
And a second surface protective layer comprising a volatile metal-containing compound or a mixed gas of a volatile metal-containing compound and a volatile organic compound as a starting material, the protective layer comprising a film deposited by a glow discharge decomposition method. Or at least Sn,
It has been clarified that the above object can be achieved by using a plasma CVD thin film protective layer composed of C, O and H. This contains carbon as the main component on the organic photosensitive layer, and additionally contains only hydrogen, oxygen and nitrogen, and the ratio (N / C) of the atomic content of nitrogen and carbon is 0 <N / C ≦ 0. When the first surface protective layer is 005, the organic photosensitive layer is chemically and physically damaged by the atmosphere (plasma state) when the second surface protective layer is formed. It is thought that it can be significantly reduced compared to the above, but the detailed mechanism thereof has not yet been clarified at this time.

The present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an electrophotographic photoreceptor of the present invention, which has a structure in which a photosensitive layer 2, a first surface protective layer 3, and a second surface protective layer 4 are sequentially provided on a conductive support 1. is there. Figure 2 (a)
2A to 2D show structural examples of other electrophotographic photoconductors of the present invention. In FIG. 2A, the photosensitive layer 2 includes a charge generation layer (CGL) 2a and a charge transport layer (CTL) 2b. 2B, a photosensitive layer 2, a first surface protective layer 3, and a second surface protective layer 4 are sequentially provided on a conductive support 1 with an undercoat layer 5 interposed therebetween. It is provided, and FIG.
(C) is a structure in which photosensitive layers 2a and 2b of a function separation type, a first surface protective layer 3, and a second surface protective layer 4 are sequentially provided on a conductive support 1 through an undercoat layer 5, FIG. 2D shows a case where the stacking order of CGL and CTL of the function-separated type photosensitive layer 2 is reversed.
In addition, the photosensitive layer 2 and the first surface protective layer 3 on the conductive support 1,
As long as it has at least the second surface protective layer 4, the above-mentioned other layers and the types of the photosensitive layer may be arbitrarily combined.

In the present invention, the conductive support used in the electrophotographic photoreceptor is a conductor or an insulator subjected to a conductive treatment, for example, a metal such as Al, Fe, Cu, Au or an alloy thereof, Al, on an insulating substrate such as polyester, polycarbonate, polyimide, glass,
It is possible to use a thin film of a metal such as Ag or Au or a conductive material such as In ₂ O ₃ , SnO _2, or a paper that has been subjected to a conductive treatment. The shape of the conductive support is not particularly limited and is plate-shaped,
Either a drum shape or a belt shape can be used. An undercoat layer, which is optionally provided between the conductive support and the photosensitive layer, is provided for the purpose of improving the photosensitivity and the adhesiveness, and the material thereof is SiO, Al ₂ O ₃ , or silane coupling. Inorganic materials such as agents, titanium coupling agents, chromium coupling agents, and polyamide resins, alcohol-soluble polyamide resins, water-soluble polyvinyl butyral, polyvinyl butyral, and binder resins with good adhesiveness such as PVA are used. In addition, it is also possible to use a resin in which ZnO, TiO ₂ , ZnS, or the like is dispersed in the resin having good adhesiveness. As a method for forming the undercoat layer, a method such as sputtering or vapor deposition is used when the inorganic material is used alone, and a usual coating method is used when the organic material is used. The thickness of the undercoat layer is appropriately 5 μm or less. The organic photosensitive layer provided on the conductive support directly or through an undercoat layer may be of a single layer type or a function separation type. These will be briefly described below.

Examples of the single-layer organic photosensitive layer include dye-sensitized photoconductive powders of zinc oxide, titanium oxide, zinc sulfate, etc., amorphous silicon powders, squaric salt pigments, phthalocyanine pigments, and azurenium salts. A pigment, an azo pigment, or the like, which is applied and formed together with a binder resin and / or an electron-supplying compound described later, as necessary, or an electron is added to a eutectic complex formed from a pyrrole-based dye and a bisphenol A-based polycarbonate. Examples include those using a composition to which a donor compound is added. As the binder resin, those similar to the function-separated type photoreceptor described below can be used. The thickness of this single-layer type photoreceptor is suitably 5 to 30 μm. On the other hand, as an example of the function-separated photosensitive layer, a charge generation layer (CG
An example is a laminate of L) and a charge transport layer (CTL). As the charge generation layer (CGL) for generating and separating latent image charges by image exposure, an inorganic photoconductive powder such as crystalline selenium or arsenic selenide or an organic dye or pigment is dispersed or dissolved in a binder resin. Used.

Examples of organic dyes and pigments as charge generating substances include CI Pigment Blue 25 [Color Index (CI) 21180], CI Pigment Red 41 (CI21200), CI Acid Red 52 (CI45100), CI Basic Red 3
(CI45210), a phthalocyanine pigment having a porphyrin skeleton, an azurenium salt pigment, a squalic salt pigment, an azo pigment having a carbazole skeleton (described in JP-A-53-95033), and an azo pigment having a styrylstilbene skeleton (53- 138229), azo pigments having a triphenylamine skeleton (described in JP-A-53-132547), and azo pigments having a dibenzothiophene skeleton (JP-A-54-21728).
JP-A No. 54-12834), an azo pigment having an oxadiazole skeleton (described in JP-A-54-12742), an azo pigment having a fluorenone skeleton (described in JP-A-54-22834), and a bisstilbene skeleton. Azo pigments (described in JP-A-54-17733) and azo pigments having a distyryl oxadiazole skeleton (JP-A-54-54).
2129), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-17734), and triazo pigments having a carbazole skeleton (JP-A-57-195767 and 57-195768). , Etc., etc., and also CI Pigment Blue 16
Phthalocyanine pigments such as (CI74100), CI Eye Brown 5 (CI73410), indigo pigments such as CI Bad Dye (CI73030), Argos Scarlet B (Violet), Indence Scarlet R (Bayer), etc. 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 appropriately used in an amount of 0 to 100 parts by weight, preferably 0 to 50 parts by weight, based on 100 parts by weight of the charge generating substance. As the binder resin used in combination with these organic dyes and pigments, polyamide, polyurethane,
Condensed resins such as polyester, epoxy resin, polycarbonate, and polyether, and polymers such as polystyrene, polyacrylate, polymethacrylate, poly-N-vinylcarbazole, polyvinyl butyral, styrene-butadiene copolymer, and styrene-acrylonitrile copolymer, and Examples include adhesive and insulating resins such as copolymers.

In the charge generation layer, the charge generation substance is dispersed with a binder resin if necessary using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, etc. by a ball mill, attritor, sand mill, etc., and the dispersion is diluted appropriately. It can be formed by coating. The coating can be performed by using a dip coating method, a spray coating method, a bead coating method, or the like. A suitable film thickness of the charge generation layer is about 0.01 to 5 μm, preferably 0.1 to 2 μm.

In the present invention, when particles of crystalline selenium or arsenic selenide alloy are used as the charge generating substance, an electron donating adhesive and / or an electron donating organic compound is used in combination. Examples of such an electron-donating substance include polyvinylcarbazole and its derivatives (for example, those having halogens such as chlorine and bromine in the carbazole skeleton, and substituents such as methyl group and amino group), polyvinylpyrene, oxadiazole, pyrazoline, and hydrazone. ,
There are nitrogen-containing compounds such as diarylmethane, α-phenylstilbene, triphenylamine compounds, and diarylmethane compounds, and polyvinylcarbazole and its derivatives are particularly preferable. Further, these substances can be used by mixing, but in this case, it is preferable to add another electron donating organic compound to polyvinyl carbazole and its derivative. The content of this type of inorganic charge generating substance is preferably 30 to 90% by weight of the entire layer. Further, the thickness of the charge generation layer when an inorganic charge generation material is used is appropriately about 0.2 to 5 μm.

The charge transport layer (CTL) is a layer for retaining the charged charge, and for moving the charge generated and separated in the charge generation layer by exposure to combine with the retained charge. High electrical resistance is required to achieve the purpose of retaining the electrostatic charge, and in order to achieve the objective of obtaining a high surface potential with the retained electrostatic charge,
It is required to have a small dielectric constant and good charge mobility. The charge transport layer for satisfying these requirements is composed of a charge transport material and a binder resin used as necessary. That is, the charge transporting layer can be formed by dissolving or dispersing the above substances in a suitable solvent and coating and drying them. The charge transport layer includes a hole transport material and an electron transport material.

As the hole-transporting substance, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene and oxazole derivative. ,
Oxadiazole derivative, imidazole derivative, triphenylamine derivative, 9- (p-diethylaminostyryl) anthracene, 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, Examples thereof include electron-donating substances such as α-phenylstilbene derivatives. Examples of the electron transport material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,7-trinitro-9-fluorenone, 2,
4,5,7-tetranitro-9-fluorene, 2,4
5,7-Tetranitroxanthone, 2,4,8-Trinitrothioxanthone, 2,6,8-Trinitro-4H-
Indeno (1,2-b) thiophenon-4-one, 1,
An electron accepting substance such as 3,7-trinitrodibenzothiophenone-5,5-dioxide may be mentioned. These charge transport materials may be used alone or in combination of two or more.

As the binder resin used as necessary, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride- Vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-
Vinylcarbazole, acrylic resin, silicone resin,
Examples thereof include thermoplastic resins or thermosetting resins such as epoxy resins, melamine resins, urethane resins, phenol resins, and alkyd resins. As the solvent, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, methylene chloride or the like is used.

A suitable thickness of the charge transport layer is 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 a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer used is preferably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil are used, and the amount thereof is preferably about 0 to 1% by weight based on the binder resin. These CGL
And CTL may be stacked on the support in the order of CGL and CTL from the support side, or may be stacked in the order of CTL and CGL. The first surface protective layer, which is laminated on the surface of the photosensitive layer for the purpose of improving peeling resistance and suppressing deterioration of chargeability, contains carbon as a main component, and additionally contains only hydrogen, oxygen, and nitrogen, and nitrogen and carbon. The ratio of the atomic weights contained (N / C) is 0 <N / C ≦ 0.0
It is composed of a high hardness thin film of No. 05.

A first surface which contains carbon as a main component and contains only hydrogen, oxygen and nitrogen in addition to the above, and the ratio (N / C) of atomic contents of nitrogen and oxygen is 0 <N / C ≦ 0.005. and the protective layer is preferably that of a film having a C-C bond similar to diamond having SP ³ orbit. The film may contain a structure similar to graphite having SP ² orbitals, and the crystal structure may be crystalline or amorphous. Such a film uses a hydrocarbon gas (methane, ethane, ethylene, acetylene, etc.) as a main material, a carrier gas such as H ₂ and Ar, and additives such as N ₂ , NH ₃ , NF ₃ , NO, and NO ₂ . It is formed by a plasma CVD method accompanied by a gas, a glow discharge decomposition method, a photo CVD method, a sputtering method using graphite or the like as a target, and the film formation method thereof is not particularly limited. According to the film forming method utilizing the glow discharge decomposition method, the support does not need to be particularly heated and the film can be formed at a low temperature of about 150 ° C. or less, so that the protective layer is formed on the organic photosensitive layer having low heat resistance. There is an advantage that there is no problem when doing it.

This carbon is the main component, and other than that, hydrogen,
The nitrogen content of the first surface protective layer containing only oxygen and nitrogen is 0 <N / C ≦ 0.005 in terms of atomic ratio with carbon (N / C).
Is preferred. When N / C = 0, the effect of suppressing the rise in the potential on the exposed portion of the photoconductor is insufficient, and when it is more than 0.005, the effect of preventing the decrease in the adhesiveness between the protective layer and the photosensitive layer during long-term use becomes insufficient. Further, the thickness of the first surface protective layer containing carbon as the main component and other than hydrogen, oxygen, and nitrogen can be adjusted by controlling the film forming time, etc., but 50 Å
A range of up to 5000Å is desirable. If it is 50 Å or less, the peeling resistance is not improved and the effect of suppressing the deterioration of the charging property is not generated.
This is because if it is 0 Å or more, the light absorption of the first surface protective layer in the visible region becomes large, and the photosensitivity of the photoreceptor is lowered.

The second surface protective layer laminated on the first surface protective layer is composed of a film containing at least carbon, a metal element, oxygen and hydrogen. Such a membrane is
It is formed by a plasma CVD method or a glow discharge decomposition method using a volatile metal-containing compound or a mixed gas of a volatile metal-containing compound and a volatile organic compound as a starting material, and its film forming method is particularly limited. However, according to the film forming method utilizing the plasma CVD method or the glow discharge decomposition method, it is not necessary to heat the support as in the first surface protective layer, and the film can be formed at a low temperature of about 150 ° C. or lower. Therefore, there is an advantage that there is no problem even when the protective layer is formed on the organic photosensitive layer having low heat resistance. Further, in the above method, since it is a gas phase film formation, it is possible to uniformly introduce each constituent element at the size of the atomic and molecular levels, few pinholes, and chemical and physical loads. The feature is that a strong film can be obtained.

The volatile metal-containing compound used when forming the second surface protective layer is a liquid or solid having a gas or vapor pressure at room temperature or a liquid or solid in which vapor pressure can be taken out without decomposition by heating. Specifically, metal alkyl compounds such as tetramethyltin [(CH ₃ ) ₄ Sn], triethylindium [(C ₂ H ₅ ) ₃ In], triethylaluminum [(C ₂ H ₅ ) ₃ Al], tetra butoxy tin _{[Sn (t-OC 4 H 9} ) 4 ], tetrapropoxytitanium [Ti (OC ₃ H _{7) 4]} metal alkoxide compounds such as tin tetrachloride (SnCl _4), titanium tetrachloride (TiCl ₄₎ or the like Metal halides, ferrocene [(C ₅ H ₅ ) ₂ Fe], nickelocene [C ₅ H ₅ ) ₂ Ni]
Metallocene compounds such as tungsten hexacarbonyl [W (CO) ₆ ], iron pentacarbonyl [Fe (C
O) ₅ ] and other metal carbonyl compounds, copper acetylacetonate [Cu (C ₅ H ₇ O ₂ ) ₂ ], nickel acetylacetonate [Ni (C ₅ H ₇ O ₂ ) ₂ ], zinc acetylacetonate [Zn (C ₅ H ₇ O ₂ ) ₂ ] and the like. It should be noted that any metal-containing compound capable of extracting the vapor pressure at room temperature or by heating can be used, and the compounds are not limited to these exemplified compounds.

On the other hand, as a volatile organic compound used in combination with a volatile metal-containing compound as a carbon source for the second surface protective layer or for the purpose of improving the film forming rate and controlling the electrical characteristics, methane (CH ₄ ) is used. , Ethane (C ₂ H ₆ ), ethylene (C ₂ H ₄ ), propene (C ₃ H ₆ ), acetylene (C ₂
H ₂ ) etc., saturated or unsaturated hydrocarbons, benzene, toluene, aromatic hydrocarbons such as phenol, acrylic acid (CH ₂ ═CH—COOH), methacrylic acid [CH ₂ ═C
(CH ₃₎ -COOH], methyl methacrylate [CH ₂ =
C (CH ₃₎ -COOCH _3], styrene

[0026]

[Chemical 1]

Acrylonitrile (CH ₂ = CH-CN)
Organic compounds such as tetramethylsilane,
Silicon-containing organic compounds such as tetramethyldisilazane and tetramethyldisiloxane can also be used. This may be gas, liquid, or solid as long as the vapor pressure can be taken out at room temperature or by heating, and is not limited to the above exemplified compounds. As these starting materials, a volatile metal-containing compound may be used alone, or a volatile metal-containing compound and a volatile organic compound may be mixed and used. Furthermore, a plurality of types of compounds may be mixed and used for each of the volatile metal-containing compound and the volatile organic compound.

In addition, a gas such as Ar, N ₂ , H ₂ or O ₂ may be used as a carrier gas in order to introduce these starting materials into the reactor. As a metal element in the second surface protective layer containing at least carbon, a metal element, oxygen, and hydrogen, Sn has favorable characteristics in terms of controllability of the protective layer specific resistance and protective layer spectral transmittance. When Sn is used as the metal element in the second surface protective layer, the composition ratio of each element is preferably in the following range from the viewpoint of the overall characteristics of electrical characteristics, optical characteristics, and mechanical characteristics.

(Sn _x O _y C _z ) _1-l H _l (x, y, z are atomic ratios, x + y + z = 1, x
= 0.05-0.7, y = 0.05-0.6, z = 0.
05-0.9, 0 ≦ 1 ≦ 0.4) If deviated from these compositions, any one of electric characteristics, optical characteristics, and mechanical characteristics deviates from a range unfavorable as a protective layer of an electrophotographic photoreceptor. I will end up. The thickness of the second surface protective layer is preferably 5000 Å to 5 μm. Fifty
When the film thickness is smaller than 00Å, mechanical durability is insufficient, and when it is larger than 5 μm, problems such as large light absorption and deterioration of minute image reproducibility occur.

A glow discharge decomposition method suitable for forming the first surface protective layer or the second surface protective layer using the above-mentioned starting material is carried out by an apparatus as shown in FIG. 3, for example. In the figure, reference numeral 21 denotes a vacuum chamber in which an object 6 to be processed made of a conductive support having an organic photoconductive layer held by a mandrel 8 rotated by a motor 7 is arranged.
A heater 9 may be provided inside the object 6 to be processed, if necessary. Further, a counter electrode 10 for performing glow discharge is provided around the object 6 to be processed. In FIG. 3, a high frequency power source 11 is connected to the counter electrode 10 and the object 6 is grounded, but the opposite may be true. Further, a bias applying power source different from the high frequency power source 11 may be connected to the object 6 to be processed. Reference numeral 12 is a vacuum pump for exhausting the vacuum chamber, 13 is an exhaust valve for exhausting and adjusting pressure, and 14 is a vacuum gauge. Reference numeral 15 is an example of a container accommodating a volatile metal-containing compound, and 17 is an example of a container accommodating a volatile organic compound. If necessary, both can be kept at a constant temperature in constant temperature baths 16 and 18. A carrier gas cylinder group 20 stores the above-mentioned carrier gas and introduces it into the vacuum chamber as needed.

In FIG. 3, glow discharge is obtained by applying high-frequency power, but the present invention is not limited to this, and glow discharge excited by direct current, light, or another method can also be used. Hereinafter, the details of the present invention will be described with reference to Examples and Comparative Examples. The amounts (parts) of each component described in the examples are parts by weight.

[0032]

【Example】

Example 1 A cylindrical support made of aluminum (outer diameter 80 mmφ,
The undercoat layer-forming liquid described below was applied to a length of 340 mm) by a dipping method so that the film thickness after drying was about 2 μm to form an undercoat layer.

[Undercoat layer forming liquid] Alkyd resin (Beckol 1307-60-EL Dainippon Ink & Chemicals) 3 parts Melamine resin (Super Beckamine G-821-60 Dainippon Ink & Chemicals) 2 parts Titanium oxide (Taipaque CR-EL Ishihara Sangyo Co., Ltd.) 25 parts Methyl ethyl ketone 15 parts After dispersing these for 3 days, methyl ethyl ketone / i-
The solution was diluted with propyl alcohol (10/5 parts), and the following composition was added dropwise to prepare an undercoat layer forming liquid. Polyethylene glycol (PEG6000S Sanyo Kasei) 0.5 part i-Propyl alcohol 5 parts A charge generation layer forming liquid containing a bisazo pigment having the following structure is dip-coated on this undercoat layer and dried at 120 ° C. for 10 minutes,
A charge generation layer (CGL) having a film thickness of about 0.15 μm was formed.

[Charge Generating Layer Forming Liquid] 1 part of bisazo pigment having the following structure

[0035]

[Chemical 2]

Methyl ethyl ketone 9 parts The above is put in a 60 mmφ glass pot, and further 5 mmφP
After adding SZ balls and ball milling for 72 hours,
A charge generation layer forming liquid was prepared by diluting with cyclohexanone / methyl ethyl ketone / polyvinyl butyral resin (40/10 / 0.1 part). Next, a charge transport layer forming liquid having the following composition was applied onto this CGL by dip coating so that the film thickness after drying was about 30 μm to form a charge transport layer (CTL), and an organic photosensitive layer was prepared. [Charge transport layer forming liquid]

[0037]

[Chemical 3]

9 parts Polycarbonate Z (molecular weight 40,000 Teijin Kasei) 10 parts Dichloromethane 85 parts Silicon oil (Shin-Etsu Chemical KF-50) 0.002 parts The above was mixed and dissolved to prepare a charge transport layer forming liquid. The organic photosensitive layer thus produced was set in the plasma CVD apparatus as shown in FIG. 3 to form the first and second surface protective layers. First, the film forming conditions for the film containing carbon as the main component and containing only hydrogen, oxygen, and nitrogen as the first surface protective layer were as follows. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 200 sccm N ₂ flow rate: 5 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: −200 V Composition of this film As a result of analysis by the XPS method, it was found that the film was composed of carbon, oxygen, hydrogen and nitrogen, and the N / C ratio was 0.002.

The thickness of the first surface protective layer was adjusted to 500Å by adjusting the film forming time. After the film formation of the first surface protective layer, the introduction of C ₂ H ₄ and the application of high frequency power were stopped, and after evacuation, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Tetramethyltin flow rate :: 25 sccm Acrylic acid flow rate :: 75 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: − The film thickness of the second surface protective layer was set to 2 μm by adjusting the film forming time of 5 V.

The composition of this film was analyzed by XPS and as a result, it was found to be (Sn _0.08 O _0.06 C _0.86 ) _0.6 H _0.4 . As described above, the electrophotographic photosensitive member of Example 1 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Example 2 An electrophotographic photoconductor of Example 2 was produced in the same manner as in Example 1 except that the thickness of the first surface protective layer was 50Å. Example 3 Example 1 except that the thickness of the first surface protective layer was set to 5000Å
An electrophotographic photoconductor of Example 3 was produced in exactly the same manner as in.

Example 4 An electrophotographic photoconductor of Example 4 was produced in exactly the same manner as in Example 1 except that the film forming conditions for the first surface protective layer were changed as follows. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 200 sccm N ₂ flow rate: ₂ sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: −200 V Composition of this film As a result of analysis by the XPS method, it was found that the film was composed of carbon, oxygen, hydrogen and nitrogen, and the N / C ratio was 0.001. The film thickness of the first surface protective layer was adjusted to 500Å by adjusting the film forming time.

Example 5 An electrophotographic photosensitive member of Example 5 was prepared in exactly the same manner as in Example 4 except that the thickness of the first surface protective layer was 50Å. Example 6 Example 4 except that the thickness of the first surface protective layer was set to 5000Å.
An electrophotographic photoconductor of Example 6 was produced in exactly the same manner as in.

Example 7 An electrophotographic photoconductor of Example 7 was produced in exactly the same manner as in Example 1 except that the film forming conditions for the first surface protective layer were changed as follows. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 200 sccm N ₂ flow rate: 10 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: −200 V Composition of this film As a result of analysis by the XPS method, it was found that the film was composed of carbon, oxygen, hydrogen and nitrogen, and the N / C ratio was 0.005. The film thickness of the first surface protective layer was adjusted to 500 Å by adjusting the film forming time.

Example 8 An electrophotographic photosensitive member of Example 8 was produced in exactly the same manner as in Example 7 except that the film thickness of the first surface protective layer was 50Å. Example 9 Example 7 except that the thickness of the first surface protective layer was set to 5000Å.
An electrophotographic photoreceptor of Example 9 was produced in exactly the same manner as in. Example 10 Example 1 except that the thickness of the second surface protective layer was set to 5000Å.
An electrophotographic photoconductor of Example 10 was produced in exactly the same manner as in. Example 11 An electrophotographic photoconductor of Example 11 was produced in exactly the same manner as in Example 1 except that the thickness of the second surface protective layer was 5 μm.

Example 12 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum exhaust was performed. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Tetramethyltin flow rate: 25 sccm Methyl methacrylate flow rate: 75 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: −10 V By adjusting the film formation time, the thickness of the second surface protective layer was set to 2 μm.

The composition of this film was analyzed by XPS, and as a result, it was found to be (Sn _0.65 O _0.19 C _0.16 ) _0.6 H _0.4 . As described above, the electrophotographic photoreceptor of Example 12 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Example 13 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum exhaust was performed. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Tetramethyltin flow rate: 75 sccm Methyl methacrylate flow rate: 25 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: −5 V By adjusting the film formation time, the thickness of the second surface protective layer was set to 2 μm.

As a result of XPS analysis of the composition of this film, it was found to be (Sn _0.60 O _0.20 C _0.20 ) _0.6 H _0.4 . As described above, the electrophotographic photosensitive member of Example 13 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Example 14 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum exhaust was performed. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Triethylindium flow rate: 25 sccm Acrylic acid flow rate: 75 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: −5 V Film formation The thickness of the second surface protective layer was set to 2 μm by adjusting the time.

As a result of XPS analysis of the composition of this film, it was found to be composed of carbon, oxygen, indium and hydrogen. As described above, the electrophotographic photoreceptor of Example 14 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Comparative Example 1 An electrophotographic photosensitive member of Comparative Example 1 was prepared by forming the organic photosensitive layer of Example 1 in exactly the same manner.

Comparative Example 2 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum exhaust was performed. After that, a film containing carbon as a main component and containing oxygen, hydrogen, and nitrogen was formed as the second surface protective layer under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 90 sccm H ₂ flow rate: 210 sccm NF ₃ flow rate: 45 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: − The film thickness of the second surface protective layer was set to 2 μm by adjusting the film forming time at 10 V. As described above, the first surface protective layer containing carbon as a main component and hydrogen, oxygen, and nitrogen in addition to the organic photosensitive layer and the second surface containing carbon, oxygen, hydrogen, and nitrogen as the main components An electrophotographic photoreceptor of Comparative Example 2 in which a protective layer was laminated was produced.

Comparative Example 3 An electrophotographic photoconductor of Comparative Example 3 was prepared in the same manner as in Example 1, except that the first surface protective layer was not formed. Comparative Example 4 An electrophotographic photoreceptor of Comparative Example 4 was produced in exactly the same manner as in Example 1, except that the thickness of the first surface protective layer was changed to 10Å. Comparative Example 5 An electrophotographic photosensitive member of Comparative Example 5 was produced in exactly the same manner as in Example 1 except that the thickness of the first surface protective layer was 1 μm.

Comparative Example 6 An electrophotographic photoconductor of Comparative Example 6 was produced in exactly the same manner as in Example 1 except that the film forming conditions for the first surface protective layer were as follows. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 200 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: −200 V Composition analysis of this film was performed by XPS method. As a result, it was found that the film was composed of carbon, oxygen and hydrogen. The film thickness of the first surface protective layer was adjusted to 500Å by adjusting the film forming time.

Comparative Example 7 An electrophotographic photosensitive member of Comparative Example 7 was prepared in exactly the same manner as Comparative Example 6 except that the thickness of the first surface protective layer was 50Å. Comparative Example 8 Comparative Example 6 except that the thickness of the first surface protective layer was set to 5000Å
An electrophotographic photoreceptor of Comparative Example 8 was produced in exactly the same manner as in.

Comparative Example 9 An electrophotographic photoreceptor of Comparative Example 9 was produced in exactly the same manner as in Example 1 except that the film forming conditions for the first surface protective layer were changed as follows. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less C ₂ H ₄ flow rate: 200 sccm N ₂ flow rate: 20 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 100 W Bias voltage: −200 V Composition of this film As a result of analysis by the XPS method, it was found that the film was composed of carbon, oxygen, hydrogen and nitrogen, and the N / C ratio was 0.008. The film thickness of the first surface protective layer was adjusted to 500Å by adjusting the film forming time.

Comparative Example 10 An electrophotographic photosensitive member of Comparative Example 10 was produced in exactly the same manner as in Example 1, except that the film thickness of the second surface protective layer was 1000 Å. Comparative Example 11 An electrophotographic photoreceptor of Comparative Example 11 was produced in exactly the same manner as in Example 1 except that the thickness of the second surface protective layer was changed to 10 μm.

Comparative Example 12 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum exhaust was performed. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Tetramethyltin flow rate: 10 sccm Acrylic acid flow rate: 90 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: −5 V By adjusting the film time, the thickness of the second surface protective layer was set to 2 μm.

As a result of XPS analysis of the composition of this film, it was found to be (Sn _0.01 O _0.04 C _0.95 ) _0.6 H _0.4 . As described above, the electrophotographic photoreceptor of Comparative Example 12 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Comparative Example 13 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and vacuum evacuation was performed. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Tetramethyltin flow rate: 25 sccm Acrylic acid flow rate: 75 sccm O ₂ flow rate: 100 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W bias Voltage: -5 V The film thickness of the second surface protective layer was adjusted to 2 μm by adjusting the film forming time.

The composition of this film was analyzed by XPS, and as a result, it was found to be (Sn _0.42 O _0.56 C _0.02 ) _0.7 H _0.3 . As described above, the electrophotographic photoreceptor of Comparative Example 13 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced.

Comparative Example 14 After the organic photosensitive layer and the first surface protective layer were formed in exactly the same manner as in Example 1, introduction of C ₂ H ₄ and application of high frequency power were stopped, and evacuation was carried out. After that, the second surface protective layer was formed under the following film forming conditions. Exhaust pressure before film formation: 2 × 10 ⁻⁵ Torr or less Ar flow rate: 100 sccm Copper acetylacetonate flow rate: 25 sccm Acrylic acid flow rate: 75 sccm Reaction pressure: 0.03 Torr High frequency power output (13.56 MHz): 200 W Bias voltage: −5 V By adjusting the film formation time, the thickness of the second surface protective layer was set to 2 μm.

As a result of composition analysis of this film by the XPS method, it was found that the film was composed of carbon, oxygen, copper and hydrogen. As described above, the electrophotographic photoreceptor of Comparative Example 14 in which the first and second surface protective layers were laminated on the organic photosensitive layer was produced. Examples 1 to 1 produced as described above
14, the protective layer of the electrophotographic photoconductors of Comparative Examples 1 to 14 and the photoconductor properties were evaluated as follows. [Spectral transmittance of protective layer] Each protective layer sample formed on a slide glass plate was measured with a spectrophotometer.

[Photoreceptor Electrostatic Properties] The following characteristic values were measured using a cylinder type photoreceptor checker (manufactured by Ricoh Co., Ltd.) (measured as necessary at the initial stage and after a running test on an actual machine). R ₈₀₀ : Resistance value at 800V in the dark E _1/10 : Light amount required for light attenuation of the photoreceptor surface potential from 800V to 80V (light source is a tungsten lamp white light) V ₃₀ : Photoreceptor 30 seconds after the start of light decay Surface residual potential ΔV ₃₀ : Increase in V ₃₀ after running 500,000 sheets [Actual machine running characteristics] Commercial plain paper copier Recopy F
Using T-3350 (manufactured by Ricoh Co., Ltd.), the characteristics of each photoconductor were evaluated at the initial stage and after running 500,000 sheets.

Fine image reproducibility: Measure how many lines are resolved per 1 mm Abrasion amount: Amount of decrease in thickness of photosensitive layer after running Number of scratches: Number of scratches on the surface of photosensitive layer after running Peeling off Characteristics: peeling state of the surface protective layer after running Evaluation results are shown in Tables 1 and 4.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

[Table 3]

[0070]

[Table 4]

The following can be clearly understood from Tables 1 to 4. The electrophotographic photoconductors of Examples 1 to 14 satisfying the claims of the present invention have: -The spectral transmittance is very good in the visible range to the long wavelength range, and the initial sensitivity is good.・ Small residual potential and good micro image reproducibility. -Even after a long-term running test, no abrasion was observed, few scratches were generated, and peeling of the protective layer was not observed, resulting in excellent mechanical durability.・ Even after a long-term running test, the charging characteristics will deteriorate.
Little increase in residual potential. As a result, it can be seen that it has extremely excellent characteristics as an ultra high durability electrophotographic photoreceptor.

On the other hand, according to the evaluation results of the comparative example, the one having no protective layer (Comparative Example 1) had very large wear and scratches due to long-term running. The one in which the second surface protective layer is composed of carbon or a film containing carbon as a main component (Comparative Example 2) has low transmittance in the visible region and low initial sensitivity. In the case where the first surface protective layer is not provided (Comparative Example 3), peeling occurs due to long-term running, and the chargeability is significantly lowered. -When the first surface protective layer is too thin (Comparative Example 4), peeling occurs due to long-term running as in Comparative Example 3, and the chargeability also deteriorates. -When the film thickness of the first surface protective layer is too thick (Comparative Example 5), the light absorption in the visible region by the first surface protective layer is large and the initial sensitivity is low. -When the 1st surface protection layer consists only of carbon, oxygen, and hydrogen (Comparative Examples 6-8), the rise of residual potential by long-term running is large.

The N / C ratio of the first surface protective layer is 0.005
When it is larger (Comparative Example 9), peeling occurs due to long-term running. -If the film thickness of the second surface protective layer is too thin (Comparative Example 10), mechanical durability is low and many scratches occur. If the second surface protective layer is too thick (Comparative Example 11), it is disadvantageous in terms of minute image reproducibility. When the composition of the second surface protective layer composed of at least Sn, C, O and H is out of the scope of the claims of the present invention, the specific resistance becomes too large, resulting in a large residual potential and a large decrease in sensitivity. However, the specific resistance becomes too small, and as a result, minute image reproducibility cannot be obtained at all (Comparative Example 13). When the second surface protective layer is composed of at least metal, C, O and H, it is not easy to simultaneously satisfy the optical, electrical and mechanical properties required for the photoconductor protective layer. There is also (Comparative Example 14).

From the above, it is clear that if the scope of the claims of the present invention is not satisfied, a protective layer which simultaneously satisfies optical, electrical and mechanical properties cannot be obtained.

[0075]

As described above, the optical, electrical,
By laminating the protective layer of the present invention having excellent mechanical properties on the organic photosensitive layer, an electrophotographic photoreceptor having very good durability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of the configuration of an electrophotographic photoreceptor of the present invention,

FIG. 2 is a schematic cross-sectional view showing the configuration of another specific example of the electrophotographic photosensitive member of the present invention,

FIG. 3 is a glow discharge decomposition method or plasma CV used in forming the first and second surface protective layers of the present invention.
The schematic diagram which shows an example of the apparatus used for D method.

[Explanation of symbols]

 1 Conductive Support 2 Organic Photosensitive Layer 2a Charge Generation Layer (CGL) 2b Charge Transport Layer (CTL) 3 First Surface Protective Layer 4 Second Surface Protective Layer 5 Undercoat Layer 6 Object (Organic Photosensitive Member) 7 Mandrel Rotating Motor 8 Mandrel 9 Heater 10 Counter Electrode 11 High Frequency Power Supply 12 Vacuum Pump for Vacuum Layer Evacuation 13 Exhaust Valve for Exhaust and Pressure Adjustment 14 Vacuum Gauge 15 Volatile Organometallic Compound Storage Container 16 Constant Temperature Tank 17 Volatile Organic Compound Storage Container 18 Constant temperature tank 19 Flow meter 20 Carrier gas cylinder group 21 Vacuum tank

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a structure in which at least an organic photosensitive layer, a first surface protective layer and a second surface protective layer are sequentially laminated on a conductive support, wherein the first surface protective layer is carbon. A main surface of the film, and other than that, containing only hydrogen, oxygen, and nitrogen, and having a ratio of the atomic weight of nitrogen and carbon (N / C) of 0 <N / C ≦ 0.005. The electrophotographic photoreceptor, wherein the protective layer is a film containing at least carbon, a metal element, oxygen, and hydrogen. 2. The second surface protective layer comprising a film containing at least carbon, a metal element, oxygen and hydrogen starts with a volatile metal-containing compound or a mixed gas of a volatile metal-containing compound and a volatile organic compound. 2. A film formed by glow discharge decomposition method as a material.
The electrophotographic photoconductor described. 3. The method according to claim 1, wherein the metal element contained in the second surface protective layer formed of a film containing at least carbon, a metal element, oxygen and hydrogen is tin. Electrophotographic photoreceptor. 4. The electron according to claim 1, wherein the composition of the second surface protective layer made of a film containing at least carbon, tin, oxygen and hydrogen is represented by the following formula. Photoreceptor for photography. (Sn _x O _y C ₂ ) _1-l H _l (where x, y and z are atomic ratios, x + y + z = 1, x
= 0.05-0.7, y = 0.05-0.6, z = 0.
05-0.9, 0 ≦ 1 ≦ 0.4) 5. The film thickness of the first surface protective layer containing carbon as a main component and other than hydrogen and oxygen is 50Å to 5
The photoconductor for electrophotography according to claim 1, wherein the photoconductor is 000Å. 6. The film thickness of the second surface protective layer made of a film containing at least carbon, a metal element, oxygen, and hydrogen is 500.
The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member has a thickness of 0 to 5 μm.