JPH04133068A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the electrophotographic sensitive body which exhibits performance stable for a long period of time by forming a protective layer embedded with columnar reinforcing materials consisting essentially of carbon on the extreme surface of the org. resin photosensitive body on a conductive base. CONSTITUTION:The reinforcing material to be embedded into the protective layer consists of the carbon or consist essentially of the carbon. The reinforcing material is formed in the form of a film on the photosensitive layer 102 by using a vapor phase method and is masked by using a photoresist to the required shape. The material is then etched by oxygen plasma. The columnar carbon materials 103 which bristle at about several mum intervals in the photosensitive layer 102 are obtd. in this way.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an electrophotographic photoreceptor having a protective layer embedded with carbon or a fine high-hardness material mainly composed of carbon on the surface of an organic resin photoreceptor. Regarding photoreceptors.

[Prior art]

Conventionally, photoreceptors used in electrophotography include those with a photoconductive layer mainly made of selenium or selenium alloys on a conductive support, and those with a photoconductive layer made of inorganic photoconductive materials such as zinc oxide or cadmium sulfate as a binder. Generally known are those using organic photoconductive materials such as poly-N-vinylcarbazole and trinitrofluorenone or ab pigments, and those using amorphous silicon-based materials. .

By the way, in general, the "electrophotographic method" means that a photoconductive photoreceptor is first charged in a dark place by, for example, corona discharge, and then exposed to image light to selectively dissipate the charge only in the exposed areas to generate electrostatic charge. A latent image is obtained, and this latent image area is developed and visualized with electrostatic fine particles (toner) consisting of a coloring material such as a dye or pigment and a binder such as a polymer substance to form an image. This is the image forming method.

The basic characteristics required of the photoreceptor in such electrophotography are (1) the ability to be charged to an appropriate potential in a dark place;

(2) Less charge dissipation in the dark.

(3) Charge can be quickly dissipated by light irradiation.

There are many things that can be mentioned.

In addition to these basic characteristics, each of the above-mentioned photoreceptors has excellent features and drawbacks in practical use.

For example, selenium or selenium alloys (5e-Te, 5e-
As.

Photoreceptors based mainly on 5e-Te-As (5e-Te-As, etc.) have been in general use for the longest time, and while they have excellent photosensitivity, they are subject to mechanical loads in the electrophotographic process (developing, cleaning, paperback, etc.). It has the disadvantage that image quality is easily affected by scratches on the surface caused by jams, etc. (white stripes, black stripes, etc.).

In addition, amorphous silicon-based photoreceptors have extremely high surface hardness and relatively high photosensitivity, but their manufacturing costs are high, and in actual use they are difficult to use due to ozone generated from chargers in the electrophotographic process. This has the problem that the surface is chemically deteriorated and abnormal images such as image blurring are likely to occur.

Furthermore, in recent years, organic photoreceptors have made remarkable progress due to their low manufacturing cost, low environmental pollution, and relatively flexible photoreceptor design.

In general, an organic photoreceptor is a material in which a charge-generating material and a charge-transporting material are dispersed or dissolved in a binder resin and coated on a conductive support. Single layer type with transport function, charge generation layer (CGL) with charge generation function, charge retention and CG
A charge transport plate (with a function of transporting charges injected from L)
(CTL), and also known as a functionally separated type, which has a laminated layer that has functions such as blocking charge injection from the support or preventing light reflection from the support, if necessary. It is being

These organic photoreceptors have excellent characteristics as mentioned above, but because they are organic materials, they have low surface hardness and are susceptible to damage from developer, transfer, cleaning materials, etc. during actual use in the copying process. It also has the essential drawback of being susceptible to wear and scratches due to mechanical loads.

This abrasion of the photosensitive layer causes a decrease in the charging potential, and local scratches cause streak-like abnormal images to appear on copies, both of which are important problems that affect the life of the photoreceptor.

In order to overcome these drawbacks, a method has been proposed in which a protective layer is provided on the surface of the photosensitive layer to improve its durability against mechanical loads received inside and outside the copying machine.

For example, a method of providing an organic film on the surface of a photosensitive layer (
Japanese Patent Publication No. 38-15446), method of providing an inorganic oxide (Japanese Patent Publication No. 43-14517), method of laminating an insulating layer after providing an adhesive layer (Japanese Patent Publication No. 43-27591), or Plas 7CVD method/photo CVD method a-3i by etc.
A method of laminating layers, a-3iNH layer, a-3i:O:8 layer, etc.
37) etc. have been disclosed. It has been recognized that these methods have some effect on improving the mechanical durability of photoreceptors. However, when laminating organic films, it is necessary to use a solvent that does not affect the organic photoreceptor, so there is little freedom in selecting materials, and silicone-based protective layers have problems such as 03 as mentioned above. It has the essential problem of being susceptible to chemical deterioration, and there are many problems that need to be solved in practical use.

Against this background, the application of carbon or highly hard thin films mainly composed of carbon as a protective layer material for photoreceptors has become active in recent years.

For example, a protective layer made of amorphous carbon or hard carbon is provided on the surface of the photoreceptor layer (Japanese Patent Laid-Open No. 6O-249155).
, one in which a diamond-like carbon protective layer is provided on the outermost surface (JP-A-6L-255352), and one in which a high-hardness insulating layer containing carbon as a main component is formed on the photoreceptor layer (JP-A-6L-255352).
-264355) or a protective layer formed of a plasma organic polymer film containing at least atoms such as nitrogen atoms, oxygen atoms, halogen atoms, alkali metal atoms, etc. on the organic photosensitive layer (JP-A-63-97961-4); A protective layer made of an amorphous hydrocarbon film generated by glow discharge containing at least chalcogen atoms, group II atoms, group II atoms, group II atoms, etc. is provided on the organic photosensitive layer.
-220166 to 9).

All of these proposals include carbon or a highly hard thin film mainly composed of carbon (i-carbon) produced on the surface of the photosensitive layer by an ion process (sputtering method, plasma CVD method, glow discharge decomposition method, photoCVD method, etc.). It forms a diamond-like carbon film.)

In these methods, the protective layer is obtained by a film-forming process that does not use a solvent, so that the effect on the organic photoreceptor is small. The second protective layer has high hardness and has been recognized as having an excellent effect in improving the durability of organic photoreceptors.

It was expected that the photoreceptors obtained by these methods would have improved adhesion between the protective layer and the organic photosensitive layer and would have excellent durability, but the adhesiveness between the protective layer and the organic photosensitive layer was not sufficient. It has become clear that the durability of the photoreceptor in actual use has not been significantly improved because the protective layer and organic resin photosensitive layer peel off at the interface between them in the copying machine. Furthermore, when used repeatedly over a long period of time during the electrophotographic process, it is clear that abnormal images, such as so-called "image blur", may occur, where the copied or printed image flows in environments with high humidity or a sudden increase in humidity. It has become. (Generally, such abnormal images are caused by various ions attached to the surface being captured in the protective layer and forming hydrophilic compounds containing nitrogen compounds, carboxy groups, and aldehyde groups, which cause damage to the photoreceptor surface. (It is said that this phenomenon occurs due to a decrease in the two-dimensional resistance of An object of the present invention is to provide an electrophotographic photoreceptor that exhibits stable performance.

[Structure of the invention]

According to the present invention, the above-mentioned object is to form an organic resin photoreceptor formed on a conductive support, in which the same organic resin as the photoreceptor is embedded with carbon or a columnar reinforcing material mainly composed of carbon. characterized by forming a protective layer of material,
This is achieved using an electrophotographic photoreceptor.

The present invention will be explained in detail below.

FIG. 1 is a schematic cross-sectional view of the electrophotographic photoreceptor of the present invention, in which a photoreceptor layer (102) is formed on a conductive support (101),
Furthermore, there is a protective layer made of an organic resin (104) made of the same material as the photosensitive layer, in which carbon or a columnar reinforcing material (103) mainly composed of carbon is embedded. A feature of the present invention is to use the same material as the photosensitive layer for the organic resin of this protective layer. By adopting this structure, the protective layer and the photosensitive layer have high adhesion and are made of organic resin with high mechanical strength. It is possible to form a photoreceptor.

FIGS. 2(A), (B), (C), and (D) each show an example of the shape and arrangement of columnar reinforcing materials that can be formed in the present invention. (A) round shape, (B) square shape, (C) triangular shape,
(D) There are many possible hexagonal types. In the reinforcing material manufacturing method described later, (A) to (
Example D) can be made as a recess, or (A) to (D)
It is easy to manufacture reinforcing materials having shapes other than those described above, and therefore, the present invention includes such application examples. It is a feature of the present invention that the reinforcements are formed in such a regular arrangement by a method of the type described below. Not limited to photoreceptor materials, dispersion-strengthening ceramics can be easily devised by dispersing powder, such as ceramics, in organic resin materials, but it can be easily devised from the technology of dispersion-strengthened ceramics. When photoreceptor materials are strengthened by dispersion, some dispersions can cause image variations. In contrast, with the method of the present invention, it is easy to control the position and size of the columnar reinforcement. The size of this columnar reinforcing material or pores is 100 μm to 1 μm, preferably 10 μm at the maximum of the pores/open spaces, taking into account the average size of binder particles used in electrophotography.
It should be formed to have a thickness of ~2 μm.

The conductive support used in the present invention may be a conductor or an insulator treated for conductivity, such as A1, Ni, Fe, etc.
In addition to metals such as , Cu, and Au, or their alloys, thin films of metals such as AI, Ag, and Au, or conductive materials such as In20i and SnO2 are formed on insulating substrates such as polyester, polycarbonate, polyimide, and glass. You can use paper that has been treated with electrical conductivity. Also,
There are no particular restrictions on the shape of the conductive support, and any of the shapes of a plate, drum, or belt can be used.

The undercoat layer is provided between the conductive support and the photosensitive layer as necessary for the purpose of improving adhesion between the photosensitive layer and the support and preventing interference of incident light, and its material is Sin. ,
Inorganic materials such as A120x, silane coupling agents, titanium coupling agents, chromium coupling agents, and binder resins with good adhesiveness such as polyamide resins, alcohol-soluble polyamide resins, water-soluble polyvinyl butyral, polyhinyl butyral, and PVA. etc. are used. In addition, a resin in which ZnO1TiO□, ZnS, etc. are dispersed in the resin with good adhesive properties can also be used. As a method for forming the undercoat layer, when an inorganic material alone is used, methods such as sputtering and vapor deposition are used, and when an organic material is used, a normal coating method is used. The thickness of the undercoat layer is suitably 5 μm or less.

FIG. 3 shows an example of a photoreceptor provided with a subbing layer (105).

The photoreceptor layer provided directly or via an undercoat layer on the conductive support may be of an organic type, and either a single layer type or a functionally separated type can be applied.

Examples of single-layer type photoreceptor layers include dye-sensitized photoconductive powders such as zinc oxide, titanium oxide, and zinc sulfate, selenium powder, amorphous silicon powder, Squaric salt pigments, phthalocyanine pigments, Those formed by coating azulenium salt pigments, azo pigments, etc. together with a binder resin and/or an electron-donating compound described below as necessary, and eutectic complexes formed from pyrylium pigments and bisphenol A-based polycarbonate. Examples include those using a composition containing an electron-donating compound. As the binder resin, the same resin as that used in the functionally separated photoreceptor layer described later can be used. The thickness of this single-layer type photoreceptor layer is suitably 5 to 30 μm.

On the other hand, an example of a functionally separated photoreceptor layer is a charge generation layer (C
An example is a structure in which a charge transport layer (GL) and a charge transport layer (CTI) are laminated.

The charge generation layer (CGL) for generating and separating latent image charges by image exposure is made by dispersing or dissolving inorganic photoconductive powder such as crystalline selenium or arsenic selenide or organic dyes and pigments in a binder resin. It is also used.

Examples of organic dyes and pigments as charge-generating substances include:
CI Pigment Blue 25 [Color Index (
CI 21180)), CI Pigment Lit 4
1 (CI 21200), Sea Eye Acid Red 52
(cl 45100), CI Basic Red 3
(Cl 45210), phthalocyanine pigments with a porphyrin skeleton, azulenium salt pigments, squalic salt pigments, and ab pigments with a carbazole skeleton (
(described in JP-A-53-95033), azo pigments having a styrylstilbene skeleton (described in JP-A-53-13822);
No. 9), ab pigments having a triphenylamine skeleton (described in JP-A-53-132547), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-132547),
21728), an azo pigment having an oxadiazole skeleton (described in JP-A-54-12742)
, an azo pigment having a fluorenone skeleton (JP-A-54-2
2834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), ab pigments having a distyryloxadiazole skeleton (described in JP-A-54-2129), Azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-17734), triazo pigments having a carbazole skeleton (JP-A-57-195767), JP-A-57-195
In addition, phthalocyanine pigments such as CI Pigment Blue 16 (CI 74100), CI Bud Brown 5 (CI 73410), etc.
), indigo pigments such as CI Bud Dye (CI 73030), and perylene pigments such as Argo Scarlet B (manufactured by Violet) and Indus Thread Scarlet R (manufactured by Bayer).

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

The amount of the binder resin is 0 to 100 parts by weight of the charge generating substance.
An appropriate amount is 100 parts by weight, preferably 0 to 50 parts by weight.

Binding resins used in combination with these organic dyes and pigments include condensation resins such as polyamide, polyurethane, polyester, epoxy resin, polycarbonate, and polyether, as well as polystyrene, polyacrylate, polymethacrylate, poly-N-vinylcarbazole, polyvinyl butyral, Adhesive and insulating resins such as polymers and copolymers include styrene-butadiene copolymer and styrene-acrylonitrile copolymer.

The charge generation layer is prepared by dispersing a charge generation substance together with an inder resin if necessary using a ball mill, attritor, sand mill, etc. using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, etc., and diluting the dispersion liquid excessively. It can be formed by coating.

Application can be carried out using a dip coating method, a spray coating method, a pea coating method, or the like.

The thickness of the charge generation layer may be approximately 0.01 to 5 μm, preferably 0.1 to 2 μm.

Furthermore, when particles of crystalline selenium or arsenic selenide alloy are used as the charge generating substance in the present invention, an electron-donating binder and/or an electron-donating organic compound are used in combination. Examples of such electron-donating substances include polyvinylcarbazole and its derivatives (for example, those having substituents such as halogen such as chlorine and bromine, methyl group, and amino group in the carbazole skeleton), polyvinylpyrene, oxadiazole, and pyrazoline. , hydrazone, diarylmethane, a-phenylstilbene, triphenylamine compounds, and diarylmethane compounds, but polyvinylcarbazole and derivatives thereof are particularly preferred. These substances can also be used as a mixture, but in this case, it is preferable to add other electron-donating organic compounds to polyvinylcarbazole and its derivatives. The amount is suitably 30 to 90% by weight of the entire layer.Furthermore, when an inorganic charge generating material is used, the thickness of the charge generating layer is 0.2 to 90% by weight.
5 μm is appropriate.

The charge transport layer (CTL) is a layer whose purpose is to hold electric charges and to move the electric charges generated and separated in the charge generation layer by exposure and combine them with the held electric charges. In order to achieve the purpose of retaining the charged charges, a high electrical resistance is required, and in order to achieve the purpose of obtaining a high surface potential from the retained charges, the dielectric constant must be small and the charge mobility must be good. required.

A charge transport layer that satisfies these requirements is composed of a charge transport substance and a binder resin used as necessary. That is, the charge transport layer can be formed by dissolving or dispersing the above-mentioned substances in a suitable solvent and applying and drying the solution.

Charge transport materials include hole transport materials and electron transport materials.

Examples of the hole transport substance include poly-N-vinylcarbazole and its dielectric, poly-γ-rubazolylethyl glitamate and its derivatives, pyrene formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, and oxazole derivatives. Diazole derivatives, imidazole derivatives, triphenylamine derivatives, 9-(pdiethylaminostyryl)anthracene,
1. Examples include electron-donating substances such as l-his-(4-dibenzylaminophenyl)propane, styryl anthracene, styryl birapurine, phenylhydrazones, and a-phenylstilbene derivatives.

Examples of electron transport substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4.7-trinitro-9-fluorenone,
2.4.5.7-tetranitro-9-fluorenone, 2
．． 4.5.7-Titranitroxanthone, 2.4.8-
Trinidrothioxanthone, 2,6. Total trinitro 4
H indeno[1,2-bl thiophenon-4-one, l
, 3.7-trinitrodibenzothiophenone-5.5
- Examples include electron accepting substances such as carbon dioxide.

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

Binder resins that may be used as necessary include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, Polymer, polyvinyl acetate, polyvinylidene chloride, polyacrylate resin, phenoxy resin,
Polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyltoluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin,
Examples include thermoplastic resins or thermosetting resins such as melamine resins, urethane resins, phenol resins, and alkyd resins.

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

The thickness of the charge transport layer is approximately 5 to 100 μm or appropriate.

Furthermore, a plasticizer or a leveling agent may be added to the charge transport layer. As plasticizers, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is approximately 0 to 30% by weight based on the binder resin. . As a leveling agent, silicone oils such as dimethyl silicone oil and methylfinyl silicone oil are used, and the amount used is 0% relative to the binder resin.
Approximately 1% by weight is appropriate.

These CGL and CTL are placed on the support from the support side.
L and CTL may be stacked in this order, or CGL and CTL may be stacked in this order.

In addition, in the present invention, an intermediate layer provided between the photosensitive layer and the surface protective layer may include 5iO1A120. Inorganic materials such as evaporation, sputtering, anodization, etc., and polyimide resin (Japanese Patent Laid-Open No. 58-30
757, JP-A-58-98739), alcohol-soluble nylon resin (JP-A-60196766), water-soluble polyvinyl butyral resin (JP-A-60196766)
232553), polyvinyl butyral resin (JP-A-58-106549), polyvinyl alcohol, or the like can be used.

Furthermore, as the intermediate layer of the present invention, a silane coupling agent,
Titanium coupling agents, chromium coupling agents, etc. can be used. The thickness of the intermediate layer is suitably 0 to 5 μm.

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

In the present invention, the reinforcing material embedded in the protective layer is carbon or carbon-based material, preferably SP
It has a C-C bond similar to diamond with 3 orbitals, and has a Vickers hardness of 100 to 3000 kg/cmz.
Specific resistance (specific resistance) l x 107 ~ l x 10'3 Ω・cm
has the value of optical energy band width (Eg)
Or1. It is OeV or more. It is formed as a columnar material that is transparent in the infrared or visible region.

There are no particular limitations on the manufacturing method for such columnar materials. In the past, proposals have been made to wrap a masking material around the photoreceptor layer and to provide a spotted amorphous hydrocarbon film on the surface using a vapor phase synthesis method or the like. (Patent application
(Heisei 2-214869) However, in such a method, the gap distance between the spots is approximately 25 to 200 μm, and considering that the average particle size of the toner powder is approximately 5 to 20 μm, it is considered that the distance between the spots is approximately 25 to 200 μm. Effects such as filming are inevitable. The present inventors formed this reinforcing material in the form of a film on the photoreceptor layer by a vapor phase method, masked it in the required shape using photoresist, and etched it with oxygen plasma. We devised a method to obtain columnar reinforcing materials that stand in layers at intervals of several micrometers.

Gas phase methods include sputtering method, plasma CVD method,
There are glow discharge decomposition methods and photo CVD methods, and the film forming method is not particularly limited in the present invention, but since it is a plasma CVD method, it is possible to form a film while having a sputtering effect. This provides a protective layer that fosters unique properties. A representative example of this is the patent application [Composite with carbon film and method for manufacturing the same] (Japanese Patent Application No. 56-1469).
29 Filed on September 17, 1981, JP 58-4960
9) etc. can be mentioned.

This method is a film formation method in which a substrate is placed on one electrode (cathode side) of a parallel plate plasma CVD device, and the film is deposited on the top surface of a flat surface using self-bias.Active species are deposited using a microwave excitation method. It is possible to obtain a carbon film with high hardness by strongly exciting the carbon.

The above method is preferably applied to substrates or sheet-shaped substrates, but for example, if a plasma CVD apparatus as shown in FIG. It is possible to make a film.

In the figure, (7) is the vacuum chamber of the plasma CVD equipment, and the loading/unloading preliminary chamber (7") is controlled by the gate valve (9).
). Inside the vacuum chamber (7) is the exhaust system (20)
[Pressure adjustment valve (21), turbo molecular pump (22)
, a rotary pump (23)], the pressure is evacuated and maintained at a constant pressure.

A reaction tank (50) is provided within the vacuum tank (7).

The reaction tank has a frame structure (2) shown in Fig. 5 (A) (B).
(having a square or hexagonal shape when viewed from the electrode side);
Hood (8) (8°) that covers the openings at both ends
It further comprises a pair of first and second electrodes (using metal mesh such as 3X3'X aluminum) having the same shape and disposed on this hood (8X8'). (30) indicates a gas line introduced into the reaction tank (50), to which various gas containers as shown below are connected, each passing through a flow meter (29) to a nozzle (25).
) into the reaction tank (50).

Carrier gas: 82. Material gas such as Ar, hydrocarbon gas (methane, ethylene, etc.) Additive gas: NF3. N1(3,PH3,B2)(
, etc. Etching gas: 02 etc. In the frame structure (2), the support (1) ((1-1), (1-2), . . . (1-n)) on which an organic highly conductive tank is formed is It is arranged as shown in Figure 5 (A) and (B). Note that each of these supports is arranged as a third electrode as described later.

A pair of power supplies (15) [(15-2)] for applying a first alternating voltage are provided to the electrodes (3) (3'), respectively. The frequency of the first alternating voltage is 1~]OO
It is MHz.

These power supplies are each matched French (16-I
Connected to X16-2). The phase in this matching transformer is adjusted by a phase adjuster, and the signals can be supplied 180° or 0° shifted from each other. That is, it has a symmetrical or in-phase output.

One end (4) and the other end (4') of the matching transformer are connected to the first and second electrodes (3) (3 degrees), respectively. Further, the midpoint (5) on the output side of the transformer is maintained at the ground level. Furthermore, between this midpoint (5) and the third electrode, that is, the support (1) [(1,-1), (1-2), .=(
1-n) or a holder (2) electrically connected to them.
A power source (17) for applying a second alternating voltage is provided to the opening of the opening. The frequency of this second alternating voltage is 1 to 5
It is 00KH2.

In this way, plasma is generated between the first and second electrodes (3) (3") by the first alternating voltage. This plasma is generated by the upper and lower hoods (8) (8"), the frame structure (2 ), it does not emit to the outside space (6), and the plasma potential within the reaction space is homogeneous. The reaction gas introduced into this reaction space through the nozzle (25) is decomposed by the energy of the plasma, accelerated by the negative self-bias (-10 to 600V) applied to the support by the second alternating voltage, and Since the film is formed on the body by sputtering, a film with a dense structure can be obtained.

The output of the first alternating voltage applied to the first and second electrodes is o, i to IKW when the frequency is 13.56 MHz, and the output of the second alternating voltage applied to the third electrode, that is, the support. The output is ], 50Kt (approximately 100W for z).

The reaction gases typically used are ethylene and NF3, the ratio of which is NF3/C2H4 = 1/20 to 4/l, and the pressure inside the vacuum chamber during the reaction is 0.001 to 1.0 torr.
It is r.

By such a method, a diamond-like thin film (also called DLC), which is decomposed in ethylene, NF, or plasma and added with N and F, is deposited on a support. (This is called a film whose main component is carbon.)

In addition, the 20 film-forming method allows the physical properties of the resulting film (hardness, light transmittance, specific resistivity, etc.) to be relatively freely changed by changing film-forming conditions such as reaction pressure and reaction gas mixture ratio. I can do it.

In particular, the hardness can be greatly changed by the negative self-bias and reaction pressure applied to the support. In addition, this method does not require any particular heating of the support;
Since carbon or a film containing carbon as a main component can be formed at a low temperature below C, it is possible to form a protective layer without any problem even on an organic photosensitive layer with low heat resistance.

The film thickness of this carbon or carbon-based protective layer is 10
0 to 10 μm, preferably 1000 to 2 μm
It is.

Additives such as halogen elements such as fluorine, nitrogen, phosphorus, and boron can be added to the carbon or carbon-based protective layer as necessary, and the concentration is uniform in the depth direction of the film. However, a gradient may be provided.

In order to draw a pattern, an example of which is shown in Figure 2, on the carbon or carbon-based film obtained in this way, a technique widely used in the semiconductor field is applied. . That is, it is selective etching using a resist.

Hereinafter, a series of steps will be explained according to FIG.

In patterning, the type of resist used does not matter. However, in the present invention, a dry etching resist is used so that patterning can be performed in a dry process without adversely affecting the photosensitive layer, and among these, a PMIPK-bisazide resist, which is a dry development type photoresist, is used. This resist contains aromatic hisazide (here, 4,4-bisazidiphenyl ether) as a photosensitive component that imparts oxygen plasma etching resistance to polymethylisopropekel (PMIPK) as a polymer component. UV-DUV (de
ep [JV□200-300 nm).

tJV-DUV exposure (a) After heating at 100°C for 25~
By heating for 30 minutes (b), an oxygen plasma-resistant mask is formed in the exposed area (c), and then by developing with oxygen plasma (d), a negative resist pattern remains.

When the protective layer masked in this way is continued to be etched with oxygen plasma, parts other than the oxygen-resistant plasma mask will be etched by the oxygen plasma, and more than 40,000 pieces of reinforcing material of a specific shape will be etched per 1 mm2. , will be uniformly formed. Forming a reinforcing material of such a size is not possible without using the forming method of the present invention.

In order to fill the holes and voids in the pattern formed by the reinforcing material and resist, the organic photosensitive material is again applied to the entire surface (e). In the present invention, as the organic photosensitive material to be reapplied for filling, the same components as the photoreceptor layer underlying the columnar reinforcing material were used. Of course, an organic photosensitive material having a different component from that of the underlying photoreceptor layer may be selected.

After drying, the excess portion of the photoreceptor material and resist is mechanically scraped off to obtain an electrophotographic photoreceptor with columnar reinforcement embedded in the surface (f).

Each part in Fig. 6 is (201) conductive substrate, (202X20
2') Photosensitive layer material, (203) carbon protective layer/reinforcing material,
(204) photoresist, (205) oxygen-resistant plasma mask.

The present invention will be explained in more detail below with reference to Examples and Comparative Examples.

rExample 1” Aluminum cylindrical support (outer diameter 60 mmφ,
An undercoat layer forming solution prepared by dispersing a mixture having the following composition ratio in a ball mill for 12 hours was applied to a length of 360 mm by a dipping method so that the film thickness after drying was approximately 2 μm to form an upper arch layer.

[Subbing layer forming liquid]

TiO□ (Tie Bake manufactured by Ishihara Sangyo Co., Ltd.) 1 part by weight Polyamide resin (CM-8000 manufactured by Toshisha Co., Ltd.) 1
Methanol 25〃A charge generation layer coating solution having the following formulation was dip coated on this subbing layer, and 120
C. for 10 minutes to form a charge generation layer.

[Charge generation layer coating liquid]

Trisazo pigment having the following structure: 30 parts by weight Cyclohexanone: 360 parts by weight The above mixture was dispersed in a ball mill for 72 hours, and then further diluted with 500 parts by weight of a mixed solvent of cyclohexanone:methyl ethyl ketone = 1:1 (weight ratio).

Then, a charge transport layer was provided on this charge generation layer by dip coating a charge transport layer coating solution having the following formulation so that the film thickness after drying was about 20 μm.

[Charge transport layer coating liquid]

Next, carbon or a cylindrical reinforcing material mainly composed of carbon was formed on this charge transport layer as described above.

However, in consideration of the binder particle size, the cylinder diameter was set to 4 μmφ and the maximum dimension of the space obtained between the cylindrical reinforcing materials was set to 3 μm so as not to damage the binder or the photoreceptor layer. Next, a charge transport layer material was applied to the hole portions, and after drying, a portion corresponding to the thickness of the mask was mechanically scraped off. In the present invention, the charge transport layer material was filled into the pores by a coating method, but if the material has a possibility of causing swelling in the underlying charge transport layer, coating by spraying, vapor deposition, etc. Gas phase methods may also be used. The total thickness of the protective layer was approximately 0.8 μm.

The synthesis conditions and etching conditions for the carbon film are as follows <Carbon film synthesis conditions> Silicone oil 0.0002 parts by weight (
Product name KF50: Shin-Etsu Silicone) Tetrahydrofuran 80 parts by weight 1 Bias potential:
-300V <Etching conditions> rComparative example 1j In Example 1, the carbon film synthesized to form the columnar reinforcement was used as it was as a protective layer, and no particular etching was performed.

"Example 21 The raw material gas for the carbon film in the example was C2H4+NF3
A protective layer was formed in the same manner as in the example except that only C2H4 was used instead of C2H4.

"Comparative Example 2" In Example 2, the columnar reinforcing material was not formed and the carbon film was used as it was as a protective layer.

The photoreceptors thus obtained (Examples 1 and 2 and Comparative Examples 1 and 2) were installed in an actual copying process (a negative-positive development type laser printer), printed repeatedly, and image evaluated. However, the photoreceptor was used in an uncharged state, and the image was evaluated to see whether the print was well resolved with a line pattern of approximately 5 lines/mm. Shown below.

Table 1 A-D is the evaluation ranking (image deterioration and peeling occur in the order of A-D) From these results, the protective layer embedded with carbon or carbon-based columnar reinforcing material of the present invention can be used even under high humidity and temperature conditions. It was found that it is possible to provide clear images while maintaining high protection ability.

〔Effect of the invention〕

As explained above, the electrophotographic photoreceptor of the present invention maintains stable high image quality over a long period of time due to the durability of the surface protective layer made by embedding carbon or a reinforcing material mainly composed of carbon. Something comes up.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing the basic structure of the electrophotographic photoreceptor of the present invention. FIGS. 2(a) to 2(d) are examples of the arrangement of columnar carbon materials or filling holes in the surface protective layer. Figure 3 is an example of a subbing layer provided between the support and the photoreceptor. FIG. 4 is an example of a plasma CVD apparatus used for producing columnar carbon materials. FIG. 5 is an example of a frame structure in a plasma CVD apparatus used for producing columnar carbon materials. Figure 6 is a simple flowchart up to the production of the protective layer. (101) Conductive substrate photoreceptor layer photoreceptor layer refilled with columnar carbon material subbing layer

Claims (1)

[Claims] 1. In a photoconductor having an organic resin photoreceptor on a conductive support, a reinforcing material is provided by regularly embedding fine high-hardness material in the surface layer of the photoreceptor material, and A photoreceptor for electrophotography, characterized in that the photoreceptor is reinforced by filling the gap with a polymeric material. 2. In claim 1, the polymeric material filled in the etched gaps between the columnar materials of the protective layer to be formed is:
An electrophotographic photoreceptor characterized by being made of an organic resin photoreceptor material. 3. In claim 1, it is stated that the high hardness material is a columnar material made from carbon or a film mainly composed of carbon, which is provided on the surface of an organic resin photoreceptor using a vapor phase method. Characteristic electrophotographic photoreceptor. 4. The electrophotographic photoreceptor according to claim 3, wherein the columnar material is formed by selective dry etching using a plasma-resistant resist.