JP2002236383A - Electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized high-speed electrophotographic device capable of forming an image of very high resolution, and having a less frequency in terms of the replacement of components. SOLUTION: In for the electrophotographic device equipped with at least an electrophotographic photoreceptor, an electrifying means, an image exposing means and a developing means, the average beam diameter of the writing light source of the image exposing means is controlled to be 10 to 40 μm, the electrophotographic photoreceptor is constituted of a photoreceptive layer obtained by laminating a Hall transport layer, a charge generation layer and a surface protecting layer in this order on the conductive substrate, and the volumetric resistance of the surface protecting layer is >=104 Ω.cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus such as a copying machine, a printer, a facsimile, etc., an electrophotographic photosensitive member and a process cartridge used therefor, and an electrophotographic method.

[0002]

2. Description of the Related Art In recent years, the development of information processing systems using electrophotography has been remarkable. In particular, a printer using a digital recording method of converting information into a digital signal and recording information by light has remarkably improved in print quality and reliability. This digital recording method is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. Further, since the digital copier is added with various information processing functions, its demand is expected to increase in the future. However, current electrophotographic devices are 300-600 dp
The resolution was about i, which was not enough as a photographic image. There is a demand for a higher resolution electrophotographic apparatus, and development for it has been performed. To increase the resolution, it is effective to reduce the minimum dot diameter. For that purpose, an image exposure means with a smaller beam diameter, an electrophotographic photosensitive member that enables a small potential latent image, and a reproducible Developing means for developing is required.

[0003] However, an electrophotographic apparatus satisfying all of these has not yet been developed. Conventionally, a small, inexpensive and highly reliable semiconductor laser (L
D) and light emitting diodes (LEDs) are often used.
The oscillation wavelength range of the currently most frequently used LD is 780-
It is in the near infrared light region near 800 nm. The beam spot diameter is about 150 to 60 μm. A dot diameter of about 30 μm or 2400 equivalent to 1200 dpi
In order to narrow down the dot diameter to about 15 μm, which is equivalent to dpi, ultra-high precision optical parts and large optical members are required, and it has not been possible to practically use it in terms of cost and space. To solve this problem, it is considered effective to shorten the wavelength of the light source, and an electrophotographic apparatus using a short wavelength laser has been proposed (Japanese Patent Laid-Open No. 19598/1993).
However, an ultra-high resolution image could not be obtained only by reducing the beam diameter in this way. Electrophotographic photoreceptors used in conventional electrophotographic devices generally include a so-called function-separated type photoreceptor in which a charge generation layer is formed on a conductive support and a charge transport layer is provided thereon. It is. Further, a surface protective layer may be formed on the outermost surface of the photoconductor in order to improve mechanical or chemical durability. In this function-separated type photoconductor, when the photoconductor whose surface is charged is exposed, light passes through the charge transport layer and is absorbed by the charge generation material in the charge generation layer. The charge generating material absorbs this light to generate charge carriers. The generated charge carriers are injected into the charge transport layer and move in the charge transport layer along the electric field generated by the charging to neutralize the surface charge of the photoreceptor. As a result, an electrostatic latent image is formed on the surface of the photoconductor. Therefore, the function-separated type photoreceptor has a charge generation material that mainly absorbs light from the near-infrared region to the visible region and does not hinder the transmission of the absorbed light of the charge generation material. In many cases, a combination with a charge transporting material having absorption is used. When such an electrophotographic photoreceptor is used,
Light having a very short wavelength, such as 400 to 450 nm, has a drawback in that the light is absorbed by the charge transport layer and sensitivity is reduced. For this purpose, an electrophotographic apparatus using a charge transport material having relatively low absorption has been proposed. Even if the charge generation layer of the electrophotographic photosensitive member can be irradiated with light having a small beam diameter, it is still difficult to form a super-resolution image. As the image formation speeds up and digitization proceeds, the energy density of the light-irradiated portion increases, and the charge density generated in the charge generation layer of the electrophotographic photosensitive member increases. Charges generated at high density diffuse in the plane direction while moving through the charge transport layer to the surface of the photoreceptor, and even if the beam diameter is reduced, the electrostatic latent image formed on the photoreceptor becomes large. Was. To solve this problem, it is effective to reduce the thickness of the charge transport layer of the electrophotographic photosensitive member.
It is necessary to reduce the charge reproducibility to 2/3, the charge stability, the life, and the dot reproducibility decrease due to potential unevenness due to the unevenness of the conductive support. Under such circumstances, an electrophotographic apparatus having an ultra-high resolution has not yet been provided on the market.

On the other hand, as an electrophotographic photoreceptor used in an electrophotographic apparatus, a single-layer type electrophotographic photoreceptor having a photosensitive layer containing a charge generating material, a charge transporting material and a binder as main components on a conductive support is known. Are known. Since the photoreceptor generates charges by light irradiation at the surface of the photoreceptor, the spread of the electrostatic latent image is reduced, which is advantageous for ultra-high resolution electrophotography. However, the sensitivity and residual potential characteristics are inferior to the function-separated type photoreceptor, and there remains a problem for an electrophotographic apparatus that requires high speed. In addition, an inverse layer type electrophotographic photoreceptor in which a charge transport layer and a charge generation layer are laminated on a conductive support in this order is also known. Also in this case, since the charge is generated at the surface of the photoreceptor, the spread of the electrostatic latent image is reduced, which is advantageous for ultra-high resolution electrophotography. For example,
Japanese Patent Application Laid-Open No. 9-240051 discloses an oscillation wavelength of 400 to 50.
An electrophotographic apparatus using a 0 nm LD as a light source is disclosed. However, in this photoreceptor layer configuration, since a fragile thin-film charge generation layer is formed on the outermost surface, it is charged,
It is not practical because the developing, transferring and cleaning means are susceptible to mechanical and chemical hazards and the photoreceptor is significantly deteriorated by repeated use. In order to prolong the life, a reverse layer photoreceptor having a surface protective layer formed thereon has also been proposed (JP-A-1-170951). In this case, the aim is to provide an electrophotographic apparatus that reduces the amount of generated ozone and has a small environmental load, and has not been designed as a photoconductor for an ultra-high resolution electrophotographic apparatus. As described above, a configuration for preventing the spread of an electrostatic latent image has been proposed as an electrophotographic photoreceptor. Considering the spread of the electrostatic latent image, an electrophotographic apparatus which forms an ultra-high resolution image, has high speed, and has excellent durability cannot be provided.

In general, in order to form an image by an electrophotographic method, the surface of an electrophotographic photosensitive member (hereinafter, also simply referred to as a photosensitive member) is first charged in a dark place by, for example, corona discharge, and the like.
Next, image exposure is performed to selectively dissipate the charge of only the exposed portion to obtain an electrostatic latent image, and the latent image portion is developed with a toner including a colorant such as a dye or a pigment and a polymer material. Then, the toner image is transferred and fixed onto a transfer material to form an image, and the transferred photoreceptor is subjected to cleaning and elimination of residual toner, and is repeatedly used for a long period of time, so-called Carlson process. This is performed by image formation.

Heretofore, various inorganic and organic photoconductors have been known as photoconductors of the electrophotographic photosensitive member. In general, a photoreceptor using an organic photoconductor has a higher degree of freedom in a photosensitive wavelength range, a film forming property,
Currently, most photoconductors use organic photoconductors because of their advantages in flexibility, film transparency, mass productivity, toxicity and cost. The photoreceptor used repeatedly in electrophotography and similar processes has sensitivity,
It has excellent electrostatic properties such as receptive potential, potential holding property, potential stability, residual potential, and spectral sensitivity, as well as physical properties such as printing durability, abrasion resistance, and moisture resistance when used repeatedly. Is also required to be good. In recent years, the development of information processing systems using electrophotography has been remarkable, especially printers using digital recording, which converts information into digital signals and records information using light, have a high print quality and reliability. The improvement is remarkable.
This digital recording method is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. Further, since the digital copier is added with various information processing functions, its demand is expected to increase in the future.

At present, in the field of electrophotographic printers, facsimile machines, electrophotographic copiers and the like, particularly in the field of printers and facsimile machines, the use form has shifted from office use to personal use. Cost reduction, maintenance-free, etc. are required, and further higher speed and higher image quality are being promoted in accordance with the improvement of image processing technology in the future. The conditions of use are becoming more stringent. Particularly, in the cleaning section, a rubber blade is used, and for sufficient cleaning, an increase in rubber hardness and an increase in contact pressure are inevitable, and therefore, abrasion of the photoreceptor is promoted, and potential fluctuation and sensitivity fluctuation are caused. Problems such as abnormal images, color balance of color images being lost, and problems in color reproducibility occur.

Most of electrophotographic photoconductors put into practical use are function-separated electrophotographic photoconductors in which a charge generation layer and a charge transport layer are laminated on a conductive substrate, and these are mainly negatively charged electrophotographic photoconductors. Used in the photographic process. The reason is that most organic materials exhibiting a high charge mobility that does not hinder the high-speed copying process are currently limited to donor compounds having only the property of hole transfer. This is because, in the operation principle, the chargeability of a laminated electrophotographic photosensitive member having a charge transport layer formed on the surface side is limited to negative charge. Further, a highly reliable charging method in the electrophotographic process is based on corona discharge, and most copying machines and printers adopt this method. However, as is well known, the corona discharge of the negative polarity is more unstable than that of the positive polarity, and therefore, a charging method using a scorotron is adopted, which is one of the factors for increasing the cost. In addition, since corona discharge with negative polarity involves a greater amount of ozone, a substance that causes chemical damage, the binder resin and charge transfer material are oxidized and degraded by ozone generated during charging over a long period of time, and during charging, The resulting ionic compounds, such as nitrate ions, sulfate ions, and ammonium ions, accumulate on the surface of the photoreceptor, resulting in a problem that image quality deteriorates. For this reason, in order to prevent ozone from being discharged outside, ozone filters are often used in copying machines and printers of the negative charging type, which also causes an increase in the cost of the apparatus. In addition, a large amount of ozone generates a problem of environmental pollution. In order to solve these problems, a positively charged electrophotographic photosensitive member has been developed. With the positive charging method, the amount of generated ozone is reduced, and with the use of currently widely used two-component developers, positive charging of the electrophotographic photoreceptor results in less environmental fluctuations and stable images. From this aspect, a positively charged electrophotographic photosensitive member is also desirable.

Further, as described above, a charge transporting material suitable for forming a photoreceptor to which a positive charging method can be applied by a layer structure in which a charge generating layer and a charge transporting layer are sequentially laminated on a conductive substrate has been found. In order to enable the function-separated type photoreceptor to be used in a positive charging mode, a layer configuration in which a charge generation layer is formed on a charge transport layer must be used. However, as is well known, the thickness of the charge generation layer is extremely thin, and the deterioration due to mechanical abrasion in processes such as development, transfer, and cleaning is large, and chemical deterioration such as ozone is inevitable. In order to solve these problems and ensure durability, attempts have been made to provide a protective layer on the photosensitive layer.
For example, JP-A-1-109357 and JP-A-1-1-1
JP-A-70951, JP-A-3-13961, JP-A-3-135577 and the like have attempted to increase the durability by incorporating inorganic or organic fine particles in the surface protective layer. JP-A-109357 proposes that a charge transporting material is contained in a surface protective layer to prevent deterioration of the function and characteristics as an electrophotographic photoreceptor. An attempt has been made to improve wear resistance by containing hard fine particles.

Further, as described above, the speed, size, and image quality of electrophotographic printers and electrophotographic copiers using the electrophotographic system have been increasing at present. The use conditions in the electrophotographic process have become more and more severe, and the oxidative degradation of the binder resin and the charge transport material due to ozone generated during charging due to long-term use, and ionic compounds generated during charging, such as nitrate ion, Deterioration of image quality due to accumulation of sulfate ions, ammonium ions, organic acid compounds and the like on the surface of the photoreceptor causes a problem. A method of using such as antioxidants JP 57-122444 Laid as surface preventing deterioration due to oxidation gas such as mentioned above have been proposed, the charge generation layer is one of the photoreceptor structure of the present patent Is present on top of the photosensitive layer, the charge-generating substance is degraded by oxidizing gas,
It is very difficult to prevent surface deterioration, and the above-mentioned drawbacks have not been sufficiently solved. For this reason, it has become more important to further improve the mechanical and chemical durability of the photoreceptor and to improve the properties of the surface layer.

As a light source compatible with the above-mentioned digital recording system, for example, a small, inexpensive and highly reliable semiconductor laser (LD) or light emitting diode (LED) is often used.

Recently, GaN-based semiconductors have been used as light sources for writing data in correspondence with the digital recording method.
Purple to blue short wavelength L having an oscillation wavelength at 450 nm
D, LEDs are being developed and listed. For example, when a short-wavelength LD whose oscillation wavelength is about half that of a conventional near-infrared region LD is used as a writing light source, the spot diameter of a laser beam on a photosensitive member is expressed by the following equation (1). Can be reduced considerably in theory. Therefore, they are very advantageous for increasing the writing density of the latent image, that is, the resolution. d∝ (π / 4) (λf / D) (1) (where d is the spot diameter on the photoconductor, λ is the wavelength of the laser beam, f is the focal length of the fθ lens, and D is the lens diameter) The listing of the short wavelength LDs and LEDs has advantages such as downsizing of an electrophotographic apparatus including an optical system and speeding up of an electrophotographic method by multi-beam writing due to small thermal crosstalk. 450nm
There is a demand for a high-sensitivity, high-resolution, and high-stability electrophotographic photosensitive member corresponding to the LD or LED oscillation light source. In the case of the above-mentioned layer structure, since the protective layer is provided on the photosensitive layer or the charge generation layer, the short wavelength LD or LED irradiation light which is writing light is efficiently passed through the protective layer or the charge generation layer in order to express high sensitivity. Need to feed into layers. That is, it is important that the protective layer does not absorb such light. However, when a resin containing inorganic or organic fine particles is used as the protective layer, the surface hardness is improved, but the surface energy is generally high, cleaning properties are poor, and particles are aggregated to cause light scattering. was there. Further, there is a problem in that the bright portion potential increases during long-term continuous use, and image deterioration such as a decrease in image density and a decrease in image resolution occurs. Furthermore, if the compatibility (elution) of the resin and the fine particles / solvent in the charge generation layer and the charge transport layer in the protection layer is large, the interface between the protection layer, the charge generation layer, and the charge transport layer cannot be maintained, and the latent image deteriorates. Also leads.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic apparatus capable of forming an image with an ultra-high resolution, being small, high-speed, and having a low frequency of component replacement. Another object of the present invention is excellent in mechanical durability, high image quality is maintained, and there is no potential fluctuation even when used repeatedly.
An object of the present invention is to provide a highly durable and highly sensitive electrophotographic photosensitive member, an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus.

[0014]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have completed the present invention. That is, according to the present invention, the following inventions are provided. (1) In an electrophotographic apparatus equipped with at least an electrophotographic photosensitive member, a charging unit, an image exposing unit, and a developing unit, an average beam diameter of a writing light source of the image exposing unit is 10 to 40 μm.
Wherein the electrophotographic photoreceptor comprises a photosensitive layer in which a hole transport layer, a charge generation layer, and a surface protective layer are laminated in this order on a conductive substrate, and the surface protective layer has a volume resistance of 10 ⁴ Ωcm or more An electrophotographic apparatus, comprising: (2) The electrophotographic apparatus according to (1), wherein the binder resin used for the surface protective layer has a volume resistance of 10 ⁵ Ω · cm or more. (3) The electrophotographic apparatus according to the above (1) or (2), wherein the surface protective layer contains a filler and an electron transport material. (4) The above-mentioned (1) to (1), wherein the developing means is a developing means using a toner having an average particle size of 4 to 8 μm.
The electrophotographic apparatus according to any one of (3). (5) The wavelength of the writing light source of the image exposure means is 400 to 4
(1) the semiconductor laser or the light emitting diode having an oscillation wavelength in a range of 50 nm.
The electrophotographic apparatus according to any one of (1) to (4). (6) In an electrophotographic apparatus equipped with at least an electrophotographic photosensitive member, a charging unit, an image exposing unit, and a developing unit, a semiconductor laser or a light emitting device having a writing light source of the image exposing unit having an oscillation wavelength in a range of 400 to 450 nm. A diode, wherein the electrophotographic photoreceptor comprises a photosensitive layer in which a hole transport layer, a charge generation layer, and a surface protective layer are laminated in this order on a conductive substrate, and the thickness of the hole transport layer is 5 to 20 μm; An electrophotographic apparatus, wherein the surface protective layer has a thickness of 3 to 9 μm. (7) The electrophotographic apparatus according to (6), wherein the surface protective layer contains a filler and an electron transport material. (8) The electrophotographic apparatus according to (6) or (7), wherein the developing unit is a developing unit using a toner having an average particle diameter of 4 to 8 μm. (9) The beam diameter of the writing light source of the image exposure means is 10 to 10.
The electrophotographic apparatus according to any one of (6) to (8), wherein the thickness is 30 μm. (10) In an electrophotographic photoreceptor having a photosensitive layer and a protective layer sequentially on a conductive support that operates by positive charging or directly through an undercoat layer, the protective layer emits monochromatic irradiation light having a wavelength range of 390 to 460 nm. An electrophotographic photosensitive member characterized by transmitting light. (11) The electrophotographic photosensitive member according to (10), wherein the protective layer exhibits a transmittance of 50% or more for monochromatic light in a wavelength range of 390 to 460 nm. (12) The electrophotographic photosensitive member according to (10) or (11), wherein the protective layer contains an electron transport material and a filler. (13) The electrophotographic photosensitive member according to any of (10) to (12), wherein the protective layer comprises a first protective layer and a second protective layer. (14) The electrophotographic photoreceptor according to (13), wherein the first protective layer uses a resin and a solvent other than the resin used for the photosensitive layer and a solvent that dissolves the resin. (15) The filler is titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride,
Any one or mixture of calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluorine resin powder, polysiloxane resin powder, polyethylene resin powder, and graft copolymer having a core-shell structure The electrophotographic photosensitive member according to any one of the above (12) to (14), wherein (16) The method according to (10) to (15), wherein the photosensitive layer is formed by laminating a charge transport layer and a charge generation layer on a conductive support directly or via an intermediate layer. The electrophotographic photosensitive member according to any one of the above. (17) The electrophotographic photosensitive member according to any one of the above (10) to (15), wherein the photosensitive layer is a single layer type containing a charge transport material and a charge generating material in a binder resin. body. (18) The electrophotographic photoconductor according to any one of (10) to (17) above, wherein at least the electrophotographic photoconductor, the charging unit, the image exposure unit, the developing unit, and the transfer unit are mounted. An electrophotographic apparatus, characterized in that: (19) the wavelength of the writing light source in said image exposure means 400
The electrophotographic apparatus according to the above (18), wherein the electrophotographic apparatus is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 450 nm to 450 nm. (20) At least one unit selected from the group consisting of an electrophotographic photosensitive member, a charging unit, an image exposing unit, a developing unit, a transferring unit, and a cleaning unit is integrally supported, and is detachable from an electrophotographic apparatus main body. In the configured process cartridge, the electrophotographic photosensitive member is as described in (10) above.
A process cartridge, which is the electrophotographic photosensitive member according to any one of (17) to (17). (21) The wavelength of the writing light source in the image exposure means is 400
The process cartridge according to (20), wherein the process cartridge is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of from 450 nm to 450 nm. (22) In an electrophotographic photoreceptor having an organic photoconductive photosensitive layer operated by positive charge and a protective layer, the protective layer contains an electron transport material and a filler, and the photosensitive layer and / or the protective layer is an antioxidant. An electrophotographic photosensitive member comprising: (23) The electrophotography according to (22), wherein the photosensitive layer is formed by laminating a charge transport layer and a charge generation layer on a conductive support directly or via an intermediate layer in this order. Photoconductor. (24) The electrophotographic photoreceptor according to the above (22), wherein the photosensitive layer is a single-layer type containing a charge transport material and a charge generation material in a binder resin. (25) The electrophotograph according to any one of (22) to (24), wherein the protective layer is a protective layer including a photosensitive layer and a first layer and a second layer sequentially laminated on the photosensitive layer. Photoconductor. (26) The electrophotographic photoreceptor according to any of (22) to (25), wherein the resin used for the protective layer is a protective layer containing a polyamide resin soluble in an alcohol-based solvent. . (27) The electrophotographic photoreceptor according to (26), wherein the resin used for the second protective layer is a resin other than a polyamide resin soluble in an alcohol-based solvent. (28) The antioxidant is at least one selected from the chain reaction initiation inhibitors classified as ultraviolet absorbers, light stabilizers, metal deactivators and ozone deterioration inhibitors (22). The electrophotographic photoreceptor according to any one of claims to (27). (29) The above-mentioned (22) to (27), wherein the antioxidant is at least one selected from radical chain reaction inhibitors classified as phenolic, hydroquinone-based antioxidants and amine-based antioxidants. The electrophotographic photosensitive member according to any one of the above. (30) Any of the above (22) to (27), wherein the antioxidant is at least one selected from peroxide decomposers classified as sulfur antioxidants and phosphorus antioxidants. An electrophotographic photoreceptor as described in Crab. (31) the filler, titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride,
Any one or mixture of calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluorine resin powder, polysiloxane resin powder, polyethylene resin powder, and graft copolymer having a core-shell structure The electrophotographic photosensitive member according to any one of the above (22) to (30), wherein (32) In an electrophotographic method in which charging, image exposure, development, and transfer are performed using an electrophotographic photosensitive member, the electrophotographic photosensitive member according to any one of (22) to (31) is used as the electrophotographic photosensitive member. An electrophotographic method characterized by using a body. (33) The wavelength of the writing light source in the image exposure is 400 to 4
A semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 50 nm;
The electrophotographic method according to 2). (34) In an electrophotographic apparatus equipped with at least an electrophotographic photoreceptor, a charging device, an image exposing unit, a developing unit, and a transfer unit, the electrophotographic photoreceptors described in the above (22) to (22)
An electrophotographic apparatus using the electrophotographic photosensitive member according to any one of (31). (35) The beam system of the writing light source in the image exposure is 10
The electrophotographic apparatus according to (34), wherein the thickness is 30 μm. (36) The wavelength of the writing light source in the image exposure is 400 to 4
A semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 50 nm;
4) or the electrophotographic apparatus according to (35). (37) At least one means selected from the group consisting of an electrophotographic photoreceptor, a charging device, an image exposing means, a developing means, a transferring means and a cleaning means is integrally supported, and is detachable from the electrophotographic apparatus main body. In the configured process cartridge, the electrophotographic photosensitive member according to any one of (22) to (31) is used as the electrophotographic photosensitive member.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The electrophotographic apparatus will be described for each component. The electrophotographic photoreceptor is a photoreceptor in which at least a hole transport layer, a charge generation layer, and a surface protection layer are laminated from the conductive support side. An undercoat layer may be inserted between the support and the hole transport layer in order to improve the adhesion between the support and the hole transport layer and the charge injection property.

As the conductive support, a metal plate such as aluminum, nickel, copper, titanium, gold, stainless steel, a metal drum or a metal foil, aluminum, nickel, copper, titanium, gold tin oxide, indium oxide or the like is deposited. A plastic film or a paper or plastic film or drum coated with a conductive substance is used.

As the hole transporting layer material, oxazole derivatives and oxadiazole derivatives (JP-A-52-139)
Nos. 065 and 52-139066), imidazole derivatives, triphenylamine derivatives (described in JP-A-3-285960), benzidine derivatives (described in JP-B-58-32372), α-phenyl Stilbene derivatives (described in JP-A-57-73075) and hydrazone derivatives (JP-A-55-154955)
No. 55-156954, No. 55-52063,
JP-A-56-81850), triphenylmethane derivatives (described in JP-B-51-10983), anthracene derivatives (described in JP-A-51-94829), styryl derivatives (described in JP-A-56-94829). −2924
No. 5, 58-198043), carbazole derivatives (described in JP-A-58-55252), and pyrene derivatives (described in JP-A-2-94812). Used is dispersed in a binder resin at 30 wt% to 60 wt%. As the binder resin, for example, polystyrene,
Styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer,
Polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyalate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N- Thermoplastic or thermosetting resins such as vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin and alkyd resin. These are formed by coating on a conductive support or an intermediate layer using an appropriate solvent.

The charge generating layer can be provided by adding or dissolving or dispersing a binder resin to a charge generating material and a suitable solvent, if necessary, coating and drying. Examples of the dispersion method of the dispersion liquid for the charge generation layer include a ball mill, ultrasonic waves, a homomixer, and the like.
Examples of the coating means include a dipping coating method, a blade coating method, and a spray coating method. When a charge generating material is dispersed to form a photosensitive layer, the charge generating material preferably has an average particle size of 2 μm or less, preferably 1 μm or less, in order to improve dispersibility in the layer. However,
If the above particle size is too small, it tends to aggregate,
Resistance or increase in the layer, lowered sensitivity and repetition characteristics increasing crystal defects, or on because there is a limit in miniaturizing, preferably the lower limit of the average particle size of 0.01 [mu] m. The thickness of the charge generation layer is suitably about 0.01 to 5 μm, and preferably 0.1 to 2 μm.

The charge generating materials include pigments, such as shown below, for example. As the organic pigment, for example, CI Pigment Blue 25 (color index CI 21)
180), C.I. Pigment Red 41 (CI 21
200), CI Acid Red 52 (CI 451)
00), CI Basic Red 3 (CI4521)
0), an azo pigment having a carbazole skeleton (JP-A-53
95033), azo pigments having a distyrylbenzene skeleton (Japanese Patent Application Laid-Open No. 53-133445), azo pigments having a triphenylamine skeleton (described in Japanese Patent Application Laid-Open No. 53-132347), dibenzothiophene Azo pigments having a skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), and azo pigments having a fluorenone skeleton (described in JP-A-54-12742) No. 22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), and azo pigments having a distyryloxadiazole skeleton (described in JP-A-54-21)
Azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-14967) and azo pigments having a benzanthrone skeleton. For example, CI Pigment Blue 16 (CI
74100), oxotitanium phthalocyanine, chlorogallium phthalocyanine, phthalocyanine pigments such as hydroxy gallium phthalocyanine, CI vat brown 5 (CI 73410), indigo pigments such as C.I. butt die (CI seventy-three thousand and thirty), Argo Scarlet B (Bayer) And perylene pigments such as Insence Scarlet R (manufactured by Bayer AG). These charge generating materials may be used alone or in combination of two or more.

As the solvent used for preparing the dispersion or solution of the charge generation layer, for example, N, N-dimethylformamide, toluene, xylene, monochlorobenzene, 1,2-dichloroethane, 1,1,1- Examples thereof include trichloroethane, dichloromethane, 1,1,2-trichloroethane, trichloroethylene, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, and dioxane.

As the binder resin, any conventionally known binder resin having good insulating properties can be used, and there is no particular limitation. For example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, Polyamide resin, silicone resin, addition polymerization type resin such as melamine resin, polyaddition type resin, polycondensation type resin,
And copolymer resins containing two or more of the repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer, styrene-acryl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and the like. In addition to the insulating resin described above, a polymer organic semiconductor such as poly-N-vinyl carbazole may be used. These binders can be used alone or
It can be used as a mixture of more than one kind. The amount of the binder resin is 0 to 5 with respect to 100 parts by weight of the charge generation material.
00 parts by weight, preferably 10 to 300 parts by weight, is suitable.

Since the surface protective layer is formed above the charge transporting layer, it is, of course, necessary to absorb as little as possible monochromatic irradiation light in the wavelength range of 400 to 450 nm. Materials used are ABS resin, ACS resin,
Olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal,
Polyamide, polyamide imide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone,
Resins such as polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin Can be In addition to the protective layer, a fluorine resin such as polytetrafluoroethylene, a silicone resin, and an inorganic filler or an organic filler having high hardness can be added to these resins for the purpose of improving abrasion resistance. The average particle size of these fillers 0.02μm~
3μm preferably 0.05~1μm is used. If the particle size is smaller than this, the abrasion resistance of the surface protective layer becomes weak, and a long-life image forming apparatus cannot be obtained. When the particle size is large, light scattering causes a reduction in resolution. Specific examples of the filler include titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride,
One or a mixture of calcium oxide, barium sulfate, ITO, silica, colloidal silica, alumina, carbon black, fluorine resin fine powder, polysiloxane resin fine powder, and polymer charge transporting material fine powder may be mentioned. it can.

These fillers may be surface-treated with an inorganic or organic substance for reasons such as improvement in dispersibility and surface property modification. In general, those treated with a silane coupling agent as a water-repellent treatment, those treated with a fluorinated silane coupling agent, those treated with a higher fatty acid or copolymerized with a polymer material, etc., are used. Which are treated with alumina, zirconia, tin oxide, or silica. The filler is pulverized or dispersed as it is with the electron transporting material, the binder resin, and the dispersion solvent, and coated as a photosensitive layer. The filler content in the formed surface protective layer is 5 to 50% by weight.
When the content is less than 10% by weight, the abrasion resistance is not sufficient. When the content is more than 40% by weight, the transparency of the surface protective layer is impaired, and the sensitivity is lowered. It will be. Average particle size of 0.02 to 3.0 μm,
Preferably, it is pulverized and dispersed to 0.05 to 1.0 μm. If the particle size is large, the cueing cleaning blade is scratched on the surface, causing poor cleaning and deteriorating image quality. Dispersion solvents include methyl ethyl ketone, acetone, methyl isobutyl ketone, ketones of cyclohexanone, ethers such as dioxane, tetrahydrofuran and ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, ethyl acetate and butyl acetate. Esters such as are used. Ball mill for adding grinding process
A sand mill, a vibration mill or the like is used.

The surface protective layer in the present invention preferably has an electron transporting property. That is, of the positive and negative charges generated in the charge generation layer, holes leak to the support substrate side through the hole transport layer, and electrons pass through the protective layer and are used to cancel surface charges. By performing this process smoothly, a photoreceptor having high charge stability and high repetition stability can be obtained. Additives are added because electron transportability is insufficient with only the resin film. As the additive, a conventionally known electron transport material is used. Examples of the electron transporting material include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-
Trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro- Indeno 4H-indeno [1,2-b] thiophen-4-one, 1,3,7-
Examples thereof include trinitrodibenzothiophene-5,5-dioxide, and electron transport materials represented by the following formulas (1) to (5) can be used. These electron transport materials are used alone or in combination of two or more.

[0025]

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The thickness of the surface protective layer is 1 to 15 μm,
When the thickness is less than 1 μm, the durability is weak, and therefore, a highly durable image forming apparatus cannot be obtained. If it is thicker than 15 μm,
This causes a decrease in resolution, a decrease in sensitivity, and an increase in accumulated charge, and cannot achieve ultra-high resolution, which is a major problem of the present invention. More preferably, the film thickness is 1 μm to 9 μm. By setting the film thickness in this range, both resolution and durability can be achieved. Further, in the photosensitive layer, a phenol compound, a hydroquinone compound, a hindered phenol compound, a hindered amine compound, a hindered amine and a hindered phenol, for the purpose of improving the chargeability and the like,
Such compounds present in the same molecule that can be added.

The electrophotographic photoreceptor which is a component of the image forming apparatus has been described above.
m to 30 μm, preferably 10 to 25 μm. 8μ
If thinner than m, the withstand voltage of the photosensitive layer becomes weak, discharge or caused, it becomes impossible to generate a number becomes a high-quality image formation of an abnormal image. Also, thicker than 30μm and the resolution of the time of development deteriorates.

In the electrophotographic apparatus of the present invention, the charging means includes a charger, a charger before transfer, a transfer charger, a separation charger, a charger before cleaning (corotron, scorotron), a solid charger (solid state charger), and a charger. A known means such as a roller is used. A method in which the surface of the conductive roller (including an object having a protective layer on the surface) is brought into direct contact with the surface of the member to be charged, and a voltage is applied to the roller to charge the surface of the member to be charged, or the surface of the member to be charged is contacted. A method is used in which a charging member is brought into contact, and a voltage is applied to the contact charging member to charge the surface of the member to be charged.

As the image exposure means, a semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 400 to 450 nm of a writing light source is used. When a semiconductor laser is used, the main components of the image exposure means are a semiconductor laser (LD), an aperture, a collimating lens, a main CYL, a sub CYL, a polygon mirror, a scanning lens 1, a scanning lens 2, and a mirror. L
D is controlled at an image frequency of 65 MHz or more, preferably 100 MHz or more, and more preferably 130 MHz.
z or more. In addition, temperature compensation control is performed, and the rotation speed of the polygon mirror is 50 Krpm or more, preferably 60 Krpm.
m or more. The light source is preferably used with multiple beams, at least two channels, preferably more than four channels.

[0030] As the developing means, conventionally known developing device can be used. For example, a contact development method or a non-contact development method can be used. The non-contact development method refers to a method of forming a gap between the electrostatic image bearing member and the developer bearing member with a thickness greater than the thickness of the developer layer and applying an electric field to visualize the image. The developing voltage may be DC, AC or DC + AC. AC development refers to a method in which an electrostatic latent image holding member and a developer carrying member are opposed to each other and an alternating electric field is applied to visualize the image. At this time, the average particle size of the toner used is 4 to 8 μm, and the toner may be a pulverized toner or a polymerized toner. In the case of a polymerized toner, a toner produced by a method of polymerizing a composition containing a monomer and a colorant, or a composition containing a prepolymer and a colorant in a liquid medium, or if necessary, physically or Represents chemically treated toners and developers containing these toners.

Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram for explaining the electrophotographic apparatus of the present invention, and the following modified examples also belong to the category of the present invention. In FIG. 1, a photoreceptor 1 has a charge transport layer on a conductive support,
A photosensitive layer in which a charge generation layer and a surface protection layer are sequentially laminated is provided. The photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. Known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used for the charging charger 3, the pre-transfer charger 7, the transfer charger 10, the separation charger 11, and the pre-cleaning charger 13. Can be The transfer means
Generally, the above-mentioned charger can be used, but as shown in the figure, a combination of a transfer charger and a separation charger is effective. 400 to 450 nm in the image exposure unit 5
A semiconductor laser having an oscillation wavelength in the range described above is used. Light sources such as the static elimination lamp 2 include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), and a semiconductor laser (L).
D) and general luminescent materials such as electroluminescence (EL) can be used. To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. The light source irradiates the photoreceptor with light by providing a transfer step, a charge removal step, a cleaning step, or a pre-exposure step using light irradiation in addition to the step shown in FIG.

The toner developed on the photosensitive member 1 by the developing unit 6 is being transferred onto the transfer sheet 9, not all are transferred, also caused toner remaining on the photosensitive member 1. Such toner is removed from the photoconductor by the fur brush 14 and the blade 15. Cleaning may be performed only with a cleaning brush,
As the cleaning brush, a known brush such as a fur brush or a mag fur brush is used. When the electrophotographic photosensitive member is positively charged and subjected to image exposure, a positive electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with a negative toner (electrostatic detection fine particles), a positive image can be obtained.
If the toner is developed with a positive polarity toner, a negative image can be obtained. A known method is applied to such a developing unit.
In addition, a known method is used for the charge removing means.

FIG. 2 shows another example of the electrophotographic process according to the present invention. The photoreceptor 21 has the photosensitive layer of the present invention, is driven by drive rollers 22a and 22b, is charged by the charger 23, is exposed to light by the light source 24, is developed (not shown), and is transferred by the charger 25. Exposure before cleaning by the light source 26, cleaning by the brush 27, and static elimination by the light source 28 are repeatedly performed. In Figure 5, the photosensitive member 21 (if of course this support is translucent) light irradiation of the pre-cleaning exposure from the support side in is performed.

The illustrated electrophotographic process is an example of an embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 2, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or the image exposure and the irradiation of the charge removing light may be performed from the support side. On the other hand, the light irradiation step
Although the image exposure, the pre-cleaning exposure, and the charge removal exposure are illustrated, the photosensitive member may be irradiated with light by providing other pre-transfer exposure, image exposure pre-exposure, and other known light irradiation steps.

The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, or may be incorporated in the apparatus in the form of a process cartridge. The process cartridge is configured such that at least one of a photoconductor, a charging unit, a developing unit, and a cleaning unit is integrally formed and is detachable from the apparatus main body. Although there are many shapes and the like of the process cartridge, a general example is shown in FIG. Photoreceptor 16, a charge transport layer on an electroconductive substrate, charge generation layer, a photosensitive layer surface protective layer are sequentially stacked is provided.

Next, the electrophotographic photosensitive member according to the present invention, an electrophotographic apparatus and a process cartridge using the same, and an electrophotographic method will be described in detail. A semiconductor laser (LD) or a light emitting diode (LED) having an oscillation wavelength in the range of 400 to 450 nm is used as a writing light source in the electrophotographic photosensitive member, the process cartridge using the same, and the electrophotographic apparatus in the present invention. It is. These short wavelengths L
D has a very narrow light intensity wavelength distribution, but since the oscillation peak wavelength shifts to a longer or shorter wavelength side by several nm depending on the temperature and the production lot, the protective layer can sufficiently emit light in the range of 390 to 460 nm. It is preferable to transmit the light. In addition, since these LDs have an extremely narrow light intensity wavelength distribution, the protective layer does not need to transmit light in the entire wavelength range of 390 to 460 nm, and it is sufficient that at least one desired monochromatic light can be transmitted in this region. In this case, the transmittance of the irradiation light is preferably 50% or more, and more preferably 70% or more. The protective layer does not have any flatness or smoothness due to the shape of the photosensitive member such as a drum or a sheet, or due to manufacturing problems. Absent. The transmittance in the present invention means a ratio of light obtained by subtracting scattered or reflected light on the surface of the protective layer, that is, light incident on the inside of the photoreceptor and light emerging from the opposite surface. FIG. 4 shows a schematic diagram of the transmission spectrum of the protective layer film. From FIG. 4, the transmittance for light of wavelength λ2 (nm) in the wavelength range of 390 to 460 nm is expressed by the following equation (2).
Required from. Transmittance (%) = T2 / T1 × 100 (2)

(1) Protective Layer (First Protective Layer, Second Protective Layer) The protective layer in the present invention is used here because it transmits monochromatic irradiation light in the wavelength region of 390 to 460 nm. The binder resin needs to transmit light in this wavelength range. For example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, Silicone resin, addition polymerization type resin such as melamine resin, polyaddition type resin, polycondensation type resin, and copolymer resin containing two or more of repeating units of these resins, for example, vinyl chloride-vinyl acetate copolymer Insulating resins such as styrene-acryl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and polymer organic semiconductors such as poly-N-vinyl carbazole. These binders can be used alone or as a mixture of two or more. Further, ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, polyacetal, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polyether sulfone, polyethylene, polyethylene terephthalate , Polyimide,
Acrylic resin, polymethylbenten, polypropylene,
Examples include resins such as polyphenylene oxide, polysulfone, AS resin, butadiene-styrene copolymer, polyvinyl chloride, polyvinylidene chloride resin, and fluorine resin such as polytetrafluoroethylene. However, it is not limited to this. In addition to the above, known materials such as aC and a-SiC formed by a vacuum thin film forming method can be used as the protective layer.

When the protective layer is formed by laminating the first and second protective layers, the resin used for the first protective layer may be a polyamide resin soluble in an alcohol solvent. Although it is not particularly limited as polyamide, for example, CM8000 manufactured by Toray Co., Ltd. used in this example is preferably used. Further, as the solvent, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, butyl alcohol and the like are preferably used. The thickness of the first protective layer is 0.1 μm.
Is preferably a M～2myuemu, particularly 0.5μm~1
More preferably, it is μm. If the thickness is 0.1 μm or less, the effect of maintaining the interface between the photosensitive layer and the protective layer, which is the object of the present invention, may be lost. is there. Second
As the resin used for the protective layer, a resin that does not elute into the first protective layer described above, that is, a resin that is insoluble in an alcohol-based solvent is desirable. Although not particularly limited, for example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin,
Vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin,
Addition polymerization type resins such as melamine resins, polyaddition type resins, polycondensation type resins, and copolymer resins containing two or more of the repeating units of these resins, for example, vinyl chloride-vinyl acetate copolymer, styrene- Insulating resins such as acrylic copolymers and vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, as well as polymer organic semiconductors such as poly-N-vinyl carbazole. These binders can be used alone or as a mixture of two or more. Further, materials used for the second protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, polyacetal, polyamideimide, polyacrylate, polyallyl sulfone, and polybutylene. , Polybutylene terephthalate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, AS resin, butadiene-styrene copolymer, polyvinyl chloride, polyvinylidene chloride resin,
A resin such as a fluorine resin such as polytetrafluoroethylene may be used. As a method for forming the protective layer, a normal coating method is employed. The thickness of the second protective layer is suitably about 1 to 15 μm, particularly preferably about 3 to 10 μm. If the thickness is 1 μm or less, the effect of improving durability, which is the object of the present invention, may be lost.
This is because there is a risk of causing a decrease in sensitivity and an increase in accumulated charge. By setting the film thickness in this range, both resolution and durability can be achieved. a-C formed by further more vacuum thin-film forming method in addition, a known material such as a-SiC may be used as the second protective layer.

(2) Filler In the present invention, by including a filler in the protective layer, mechanical durability can be improved. It is a known fact that the surface hardness is improved when a resin containing a filler is provided in the protective layer. That is, by simultaneously providing the resin and the filler used for the protective layer in the present invention as the protective layer of the photoreceptor, the wear resistance is further improved, and high image quality is maintained. A durable and highly sensitive electrophotographic photoreceptor can be obtained.

[0040] (3) a filler species, titanium oxide as a filler used in the protective layer of the present invention such as the amount, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, silica, colloidal Silica, alumina, carbon black, fluorine-based resin fine powder, polysiloxane-based resin fine powder, polyethylene-based resin fine powder, graft copolymer having a core-shell structure, and the like, among which titanium oxide, silica, Zirconium oxide and alumina are mentioned. Among these, the inorganic filler may be surface-treated with an inorganic or organic substance for the purpose of improving dispersibility. Generally, there are those treated with a silane coupling agent, those treated with a fluorine-based silane coupling agent, and those treated with a higher fatty acid as a water repellent treatment. Alumina, zirconia,
Tin oxide, obtained by silica treatment is known. The filler content of the protective layer containing a filler is 5 to 50% by weight, preferably 10 to 40% by weight. The reason is that when the filler content is less than 10% by weight, the abrasion cannot be sufficiently improved, and when it is more than 40% by weight, the transparency of the entire photosensitive layer is impaired. The filler has an average particle size of 0.05 to 1.0 μm, and is preferably pulverized and dispersed to 0.05 to 0.8 μm. If the average particle size is less than 0.05 μm, the particle size is too small, and improvement in wear resistance cannot be expected. On the other hand, if the average particle size is larger than 0.8 μm, the irregularities on the surface containing the filler become large, and the filler damages the cleaning blade, resulting in poor cleaning. Dispersion solvents include methyl ethyl ketone, acetone, methyl isobutyl ketone, ketones of cyclohexanone, dioxane,
Ethers such as tetrahydrofuran, ethyl cellosolve, toluene, aromatics such as xylene, chlorobenzene, halogens such as dichloromethane, ethyl acetate, esters such as butyl acetate are used. When a pulverizing step is added, a ball mill, a sand mill, a vibration mill or the like is used. As a coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

(4) Electron transporting (transferring) material A conventionally known electron transporting (transferring) material is added in order to impart an electron transporting function to the protective layer containing the filler. Examples of conventionally known electron transporting materials to be added include, for example, chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9 -Fluorenone, 2,4,5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Trinitro-indeno 4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, oxadiazole derivative, (2,3-diphenyl-1 -Indenylidene)
Malononitrile, dinitrobenzene, dinitroanthracene, malononitrile, thiopyran-based compounds, benzoquinone, quinones such as diphenoquinone, stilbenequinone and derivatives thereof, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, dibromo anhydride Maleic acid and the like can be mentioned.
The electron transport materials listed in the formula (5) can be suitably used. These electron transport materials are used alone or in combination of two or more.

Further, when a writing light source in a wavelength region of 400 to 450 nm is used, for example,
The electron transport materials listed in (5) and the following formula (6) can be suitably used. Although the electron transport materials have been described above, the present invention is not limited to these.

Embedded image These electron transport materials may be used alone or in combination of two or more. Furthermore, for example, since the diphenoquinone derivative represented by the formula (3) has absorption in a wavelength range of 390 to 460 nm, the short-wavelength LD writing light is absorbed in the vicinity of the surface of the protective layer, so that the charge generation layer Alternatively, the photosensitive layer cannot reach the photosensitive layer, and in principle, does not exhibit sensitivity. However, in this way, 390-460n
m having an absorption in the wavelength range of 390 to 4
By adding an appropriate amount to an electron transfer material that does not have absorption in the wavelength region of 60 nm, a function may be exhibited without impeding light transmission. is not. Although the electron transfer materials have been described above, the present invention is not limited to these.

The content of the electron transport material in the protective layer,
The content is preferably in the range of 20 to 100 parts by weight, more preferably 50 to 70 parts by weight, based on 100 parts by weight of the binder resin. If the amount is 20 parts by weight or less, the function of electron transfer in the protective layer becomes insufficient, and if the amount is 100 parts by weight or more, the film-forming property is reduced, and the durability may be further reduced.

(5) Description of Layer Structure FIGS. 5 and 6 are sectional views of the photosensitive member of the present invention. The photoreceptor of the present invention can be particularly preferably used by forming the protective layer on the photosensitive layer into two layers. That is, a solvent having low compatibility with the resin used for the photosensitive layer is used, and a resin soluble in the solvent is laminated as a thin film on the photosensitive layer as a first protective layer. By using a solvent having low compatibility with the resin used for the protective layer and laminating a resin soluble in the solvent as a second protective layer on the first protective layer, It is configured by containing a filler, an electron transfer material, and an antioxidant. An antioxidant or the like may be used in the photosensitive layer. In the photoreceptor of FIG. 5, a charge transport layer 5 and a charge generation layer 4 are sequentially laminated on a conductive support 1 to provide a photosensitive layer 2, and a first protective layer 6, a second protective layer 6,
The protective layer 7 is sequentially laminated to provide a protective layer.

In the single-layer photoreceptor shown in FIG. 6, a photosensitive layer 2 'in which a charge generating substance 3 is dispersed in a charge transport medium is provided on a conductive support 1, and a first protective layer is provided on the photosensitive layer. 6, a second protective layer 7 is sequentially laminated to provide a protective layer.

Here, the photosensitive member shown in FIG. 5 is a photosensitive layer 2 comprising a charge transport layer 5 having a charge transport medium on a conductive support 1 and a charge generating layer 4 mainly composed of a charge generating substance 3.
Is provided. Here, as the substance having charge transporting ability used for the charge transporting medium 5, the following hole transporting substances can be used. For example, poly
N-carbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives,
There are an imidazole derivative, a triphenylamine derivative, and a compound represented by the following general formula. Among them, the stilbene compound (3) is suitably used because of its high charge transport ability. However, the present invention is not limited to these.

(Hole transport material) (1) (JP-A-55-154955, JP-A-55-1)
No. 56954)

Embedded image In the above formula, R ¹ represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group; R ² represents a methyl group, an ethyl group, a benzyl group or a phenyl group;
R ³ represents a hydrogen atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. (2) (described in JP-A-55-52063)

Embedded image In the above formula, Ar represents a naphthalene ring, an anthracene ring, a styryl ring or a substituted product thereof, or a pyridine ring, a furan ring or a thiophene ring, and R represents an alkyl group or a benzyl group.

(3) (described in JP-A-56-81850)

Embedded image In the formula, R ¹ represents an alkyl group, a benzyl group, a phenyl group or a naphthyl group, R ² represents a hydrogen atom, 1 to carbon atoms
3 represents an alkyl group, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group or a diarylamino group, n represents an integer of 1 to 4, and when n is 2 or more, R ² is the same But it may be different. R ³ represents a hydrogen atom or a methoxy group. (4) (described in JP-B-51-10983)

Embedded image In the above formula, R ¹ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group,
R ^2, R ³ may be the each selected from the hydrogen atom, an alkyl group having 1 to 4 carbon atoms, hydroxyalkyl group, a chloroalkyl group, or a substituted or unsubstituted aralkyl group, and an R ² R ³ may combine with each other to form a nitrogen-containing heterocyclic ring. R ⁴ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a halogen atom. (5) (described in JP-A-51-94829)

Embedded image In the above formula, R represents a hydrogen atom or a halogen atom;
Represents a substituted or unsubstituted phenyl group, a naphthyl group, an antonyl group or a carbazolyl group.

(6) (described in JP-A-52-128373)

Embedded image In the above formula, R ¹ is a hydrogen atom, a halogen atom, a cyano group,
Represents an alkoxy group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and Ar represents a group represented by the following formula.

Embedded image

Embedded image In the formula, R ² represents an alkyl group having 1 to 4 carbon atoms, R ³
Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a dialkylamino group having 1 to 4 carbon atoms, n is 1 or 2, and when n is 2, R ³ is the same R ⁴ and R ^{5 each} represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted benzyl group.

(7) (described in JP-A-56-29245)

Embedded image In the above formula, R is a carbazolyl group, a pyridyl group, a thienyl group, an indolyl group, a furyl group or a substituted or unsubstituted phenyl group, a styryl group, a naphthyl group, or an anthryl group, and these substituents are dialkylamino Group, alkyl group, alkoxy group, carboxy group or ester thereof, halogen atom, cyano group, aralkylamino group, N-alkyl-N-aralkylamino group, amino group, nitro group and acetylamino group Represents a group. (8) (described in JP-A-58-58552)

Embedded image In the above formula, R ¹ represents a lower alkyl group, a substituted or unsubstituted phenyl group, or a benzyl group, and R ² and R ³ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group Alternatively, it represents an amino group substituted with a lower alkyl group or a benzyl group, and n represents an integer of 1 or 2.

(9) (described in JP-A-57-73075)

Embedded image In the formula, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, R ² and R ³ represents an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ⁴ Represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted phenyl group, and Ar represents a substituted or unsubstituted phenyl group or a naphthyl group.

(Described in JP-A-58-198043)

Embedded image In the above formula, n is an integer of 0 or 1, R ¹ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group, Ar ¹ represents a substituted or unsubstituted aryl group,
R ⁵ represents an alkyl group or a substituted or unsubstituted aryl group, including substituted alkyl groups, A represents a 9-anthryl group, or a substituted or unsubstituted carbazolyl group represented by the following formula. In the above formula, R ² represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or the following groups.

Embedded image

Embedded image

Embedded image In the above formula, R ³ and R ⁴ represent an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ³ and R ⁴ may be the same or different, and R ⁴ represents a ring. When m is 2 or more, R ² may be the same or different. When n is 0, A and R ¹ may form a ring together.

(11) (described in JP-A-49-105537)

Embedded image In the formula, R ^1, R ² and R ³ represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom or a dialkylamino radical, n represents 0 or 1. (12) (described in JP-A-52-139066)

Embedded image In the above formula, R ¹ and R ² represent an alkyl group including a substituted alkyl group, or a substituted or unsubstituted aryl group;
A represents a substituted amino group, a substituted or unsubstituted aryl group or an allyl group. (13) (described in JP-A-52-139065)

Embedded image In the above formula, X represents a hydrogen atom, a lower alkyl group or a halogen atom, R represents an alkyl group containing a substituted alkyl group,
Or A represents a substituted or unsubstituted aryl group, and A represents a substituted amino group or a substituted or unsubstituted aryl group.

(14) (described in JP-A-58-32372)

Embedded image In the formula, R ¹ represents a lower alkyl group, a lower alkoxy group or a halogen atom, R ^2, R ³ may be the same or different, represent a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom, l , M, and n represent an integer of 0 to 4. (15) (described in JP-A-2-178669)

Embedded image In the above formula, R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group,
Alkoxy group, thioalkoxy group, aryloxy group,
A methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted or unsubstituted aryl group, and R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom. However,
R ¹ , R ² , R ³ and R ⁴ are excluded unless all are hydrogen atoms. Also, k, l, m and n are 1, 2, 3 or 4
And when each is an integer of 2, 3 or 4, R ¹ , R ² , R ³ and R ⁴ may be the same or different.

(16) (described in JP-A-3-285960)

Embedded image In the formula, Ar represents a condensed polycyclic hydrocarbon group 18 or less carbon atoms, also, R ¹ and R ² are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted or unsubstituted Represents a substituted phenyl group, which may be the same or different. (17) (described in Japanese Patent Application No. 62-98394)

Embedded image In the above formula, Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and A represents a group represented by the following formula.

Embedded image In the above formula, Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ¹ and R ² are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. (18) (described in JP-A-4-230764)

Embedded image In the above formula, Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. n
Is 0 or 1, m is 1 or 2, and n = 0, m =
In the case of 1, Ar and R may form a ring together.

The compound represented by the general formula (7) includes, for example, 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1-benzyl-1 -Phenylhydrazone, 9-ethylcarbazole-3-aldehyde-
1,1-diphenylhydrazone and the like. Examples of the compound represented by the general formula (8) include 4-diethylaminostyryl-β-aldehyde-1-methyl-1-phenylhydrazone and 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone. and so on. The compound represented by the general formula (9) includes, for example, 4-
Methoxybenzaldehyde-1-methyl-1-phenylhydrazone, 2,4-dimethoxybenzaldehyde-1
-Benzyl-1-phenylhydrazone, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-methoxybenzaldehyde-1- (4-methoxy) phenylhydrazone, 4-diphenylaminobenzaldehyde-1-benzyl-1-phenylhydrazone,
4-dibenzylaminobenzaldehyde-1, 1-diphenylhydrazone and the like. Examples of the compound represented by the general formula (10) include 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, and 1,1-bis (4-dibenzylamino) Phenyl) propane, 2,2′-dimethyl-4,
4'-bis (diethylamino) -triphenylmethane and the like. Examples of the compound represented by the general formula (11) include 9- (4-diethylaminostyryl) anthracene and 9-bromo-10- (4-diethylaminostyryl) anthracene.

The compound represented by the general formula (12) includes, for example, 9- (4-dimethylaminobenzylidene) fluorene and 3- (9-fluorenylidene) -9-ethylcarbazole. Examples of the compound represented by the general formula (15) include 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene. Examples of the compound represented by the general formula (16) include 3-styryl-9-ethylcarbazole and 3- (4-methoxystyryl) -9-ethylcarbazole. Examples of the compound represented by the general formula (17) include 4-diphenylaminostilbene,
4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4-diphenylaminostyryl) naphthalene, 1- (4-diethylaminostyryl) naphthalene and the like. The compound represented by the general formula (18) includes, for example, 4′-diphenylamino-α-phenylstilbene, 4′-bis (4-methylphenyl) amino-
α-phenylstilbene and the like. The compound represented by the general formula (22) includes, for example, 1-phenyl-3- (4
-Diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazolin. Examples of the compound represented by the general formula (24) include 2-N, N-diphenylamino-5- (N-ethylcarbazol-3-yl)-
1,3,4-oxadiazole, 2- (4-diethylaminophenyl) -5- (N-ethylcarbazole-3-
Yl) -1,3,4-oxadiazole and the like. Benzidine compounds represented by the general formula (25) include, for example, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-
Diamine, 3,3'-dimethyl-N, N, N ', N'-
Examples include tetrakis (4-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine. The general formula (2
The biphenylamine compound represented by 6) includes, for example,
4'-methoxy-N, N-diphenyl- [1,1'-biphenyl] -4-amine, 4'-methyl-N, N-bis (4-methylphenyl)-[1,1'-biphenyl]-
4-amine, 4'-methoxy-N, N-bis (4-methylphenyl)-[1,1'-biphenyl] -4-amine and the like. Examples of the triarylamine compound represented by the general formula (27) include 1-diphenylaminopyrene and 1-di (p-tolylamino) pyrene. Examples of the diolefin aromatic compound represented by the general formula (28) include 1,4-bis (4-diphenylaminostyryl) benzene and 1,4-bis [4-di (p
-Tolyl) aminostyryl] benzene.

Examples of the styrylpyrene compound represented by the general formula (30) include 1- (4-diphenylaminostyryl) pyrene and 1- [4-di (p-tolyl) aminostyryl] pyrene.

[0059] In FIGS. 5 and 6, a charge generating layer 4,
The charge generating substance can be provided by dissolving or dispersing a binder resin in an appropriate solvent, if necessary, and then applying and drying the resultant. Examples of the method for dispersing the charge generating substance include a ball mill, ultrasonic wave, and a homomixer, and examples of the application method include a dipping coating method, a blade coating method, and a spray coating method. When the photosensitive layer is formed by dispersing the charge generating substance, the charge generating substance preferably has an average particle diameter of 2 μm or less, preferably 1 μm or less in order to improve the dispersibility in the layer. However, if the above particle size is too small, it tends to aggregate rather than increase, the resistance of the layer increases, the crystal defects increase and the sensitivity and repetition characteristics decrease, or there is a limit in miniaturization. Set the lower limit of the diameter to 0.
It is preferably set to 01 μm. The solvent used in preparing the dispersion or solution of the photosensitive layer 2, 2 ', for example, N, N- dimethylformamide, toluene, xylene, monochlorobenzene, 1,2-dichloroethane,
1,1,1-trichloroethane, dichloromethane, 1,
Examples thereof include 1,2-trichloroethane, trichloroethylene, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, and dioxane. As the binder used for forming the photosensitive layer, any conventionally known binder for an electrophotographic photosensitive member having good insulating properties can be used, and there is no particular limitation. For example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin,
Methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, polyamide resin, silicone resin, addition polymerization type resin such as melamine resin, polyaddition type resin, heavy condensation type resins, and copolymer resins, such as vinyl chloride containing two or more of the repeating units of these resins - vinyl acetate copolymer,
In addition to insulating resins such as styrene-acrylic copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin,
A high molecular organic semiconductor such as poly-N-vinyl carbazole may be used. These binders can be used alone or as a mixture of two or more.

The charge generating substance used in the present invention is:
For example it is possible to use a pigment, such as shown below. As an organic pigment, for example, CI Pigment Blue 2
5 (color index CI 21180), C.I. Pigment Red 41 (CI. 21200), C.I. Acid Red 52 (CI. 45100), C.I. Basic Red 3 (CI. 45210), azo pigments having a carbazole skeleton (see Described), azo pigments having a distyrylbenzene skeleton (JP-A-53-133445), azo pigments having a triphenylamine skeleton (described in JP-A-53-132347), azo pigments having a dibenzothiophene skeleton (Described in JP-A-54-21728) and azo pigments having an oxadiazole skeleton (JP-A-54-12742).
Azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a bisstilbene skeleton (described in JP-A-54-17733), distyryl oxadiazole An azo pigment having a skeleton (described in JP-A-54-2129) and an azo pigment having a distyrylcarbazole skeleton (described in JP-A-52-129)
Azo pigments such as C.I. Pigment Blue 16 (CI 7410).
0), phthalocyanine-based pigments such as titanyl phthalocyanine, for example, C-Ivat Brown 5 (CI 73
410), and indico-based pigments such as CI bat die (CI 73030), and perylene pigments such as Argoscarlet B (manufactured by Bayer) and Insence Scarlet R (manufactured by Bayer). Incidentally, these organic pigments alone or two or more of them may be used in combination. In addition, among the above-mentioned charge generating substances, a photoreceptor having high sensitivity and high durability can be obtained by combining with the phthalocyanine pigment. The phthalocyanine pigment, a compound having a phthalocyanine skeleton represented by the following formula, M (center metal) is an element of metal and metal-free (hydrogen) and the like.

[0061]

Embedded image

Here, M (center metal) is H,
Li, Be, Na, Mg, Al, Si, K, Ca, S
c, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Ga, Ge, Y, Zr, Nb, Mo, Tc, R
u, Rh, Pd, Ag, Cd, In, Sn, Sb, B
a, Hf, Ta, W, Re, Os, Ir, Pt, Au,
Hg, TI, La, Ce, Pr, Nd, Pm, Sm, E
u, Gd, Tb, Dy, Ho, Er, Tm, Yb, L
It consists of a simple substance such as u, Th, Pa, U, Np, and Am, or two or more kinds of elements such as oxide, chloride, fluoride, hydroxide, and bromide. The central metal is not limited to these elements. The charge generation material having a phthalocyanine skeleton in the present invention has only to have a basic skeleton of at least the general formula (N), 2-mer, those with multimeric structure such as trimer, further higher order high It may have a molecular structure. Further, those having various substituents in the basic skeleton may be used. Among these various phthalocyanines, oxotitanium phthalocyanine having TiO as a central metal and metal-free phthalocyanine having H are particularly preferable in terms of photoreceptor characteristics. It is also known that these phthalocyanines have various crystal systems. For example, in the case of oxotitanium phthalocyanine, α, β, γ,
In the case of copper phthalocyanine such as m-type or y-type, it has a polymorphism such as α, β, γ. Even for phthalocyanines having the same central metal, various characteristics change due to the change in the crystal system. Among them, it has been reported that the characteristics of the photoreceptor also change with such a change in the crystal system. (Journal of the Electrophotographic Society, Vol. 29, No. 4, 1990). From this, each phthalocyanine has an optimal crystal system in terms of the photoreceptor characteristics. Is desirable. These charge generating substances may be a mixture of two or more charge generating substances having a phthalocyanine skeleton. Further, it may be mixed with other charge generating substances. In this case, examples of the charge generating substance to be mixed include an inorganic material and an organic material.

Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous silicon. In the case of amorphous silicon, a material obtained by terminating a dangling bond with a hydrogen atom or a halogen atom, or a material obtained by doping a boron atom, a phosphorus atom, or the like is preferably used. On the other hand, as organic materials,
Azurenium salt pigments, methine squaric acid pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton,
An azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazol skeleton, an azo pigment having a bisstilbene skeleton, an azo pigment having a distyryloxadiazol skeleton, an azo pigment having a distyrylcarbazole skeleton,
Perylene pigments, anthraquinone or polycyclic quinone pigments, quinone imine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments and the like. No.

In the case where a photoreceptor is prepared using the above-described layer constitution and substance, there are preferable ranges for the film thickness and the ratio of the substance. In the case of the reverse layer photoconductor <function-separated type (conductive support 1 / charge transport layer 5 / charge generation layer 4)>, a binder is optionally used in the charge generation layer 4, and in that case, the binder is used. The ratio of the charge generating substance 3 to the agent is preferably 20% by weight or more, and the film thickness is preferably 0.01 to 5 μm. In the charge transport layer, the ratio of the charge transport material to the binder is 20 to 200.
It is preferable that the weight% and the film thickness be 5 to 100 μm. Or it may form a charge transport layer 5 on its own when using a polymer charge transport material. Further, the charge generation layer preferably contains a charge transporting substance, which has the effect of suppressing residual potential and improving sensitivity. In this case, the charge transport material is 20 to 2 with respect to the binder.
It is preferred that the content be contained at 00% by weight. In the case of a single-layer type photoreceptor, the ratio of the charge generating substance 3 to the binder resin in the photosensitive layer is 5 to 95% by weight, and the film thickness is 10 to 1%.
It is preferably set to 00 μm. When combined with a charge transport material, the ratio of the charge transport material to the binder resin is preferably from 30 to 200% by weight. Alternatively, the photosensitive layer may be formed of a polymer type charge transporting material and a charge generating material 3, and the ratio of the charge generating material 3 to the polymer type charge transporting material is 5 to 5.
Preferably, the thickness is 95% by weight and the film thickness is 10 to 100 μm.

(7) Description of Each Material The following can be used for the conductive support 1 in the production of the photoreceptor of the present invention. That is, volume resistance 10 ¹⁰
Ω or less, such as aluminum, nickel, chromium, nichrome, copper, titanium, silver, gold, platinum,
Metals such as iron, or oxides such as tin oxide and indium oxide coated on film or cylindrical plastics or paper by vapor deposition or sputtering, or plates of aluminum, aluminum alloy, nickel, stainless steel, etc. Examples of such pipes include pipes formed by extruding, drawing, or the like, and then surface-treated by cutting, superfinishing, polishing, or the like. In order to actually produce the photoreceptor shown in FIG. 5 of the present invention, the charge transport layer 5 is formed on the conductive support 1.
Is formed, the charge generation layer 4 may be formed. By forming the above-mentioned protective layers 6 and 7 on the charge generation layer 4 of the photoreceptor thus obtained, the photoreceptor shown in FIG. 5 can be produced. In addition, to produce the photoreceptor shown in FIG. 6, fine particles of the charge generating substance 3 and a filler and an electron transfer material are dispersed in a solution dissolved in a charge transporting substance and a binder. What is necessary is just to apply | coat on body 1, and to dry, and to form photosensitive layer 2 '. The thickness of the photosensitive layer 2 'is 3 to 100.
μm, preferably 5 to 40 μm is suitable. The amount of the binder occupying the photosensitive layer 2 'is 40 to 90% by weight,
The amount of the charge generating substance 3 occupying the photosensitive layer 2 'is 0.1 to
It is 50% by weight, preferably 1 to 20% by weight.

(8) Other Additives, Subbing Layer, etc. In all the constitutions of the electrophotographic photosensitive member according to the present invention shown in FIGS. Can be provided with an undercoat layer. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving coating properties of the upper layer, reducing residual potential, and the like. The undercoat layer generally contains a resin as a main component. However, considering that these resins are coated thereon with a photosensitive layer using a solvent, the resin may be a resin having high resistance to dissolution in general organic solvents. desirable. Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, polyurethane, melamine resin, alkyd-melamine resin, and epoxy resin. , A curable resin forming a three-dimensional network structure, polyamide, polyurethane, polyester, epoxy resin, polyarylate, polyketone, polycarbonate, polyvinylketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide, polysulfone, methacrylic resin, acetic acid Vinyl, phenoxy resin and the like are used, and any resin having an insulating property and an adhesive property can be used. These binders can be used alone or as a mixture of two or more. Additionally, a plasticizer can be added to the binder. Examples of the plasticizer include halogenated paraffin, dimethylnaphthalene, and dibutylphthalate. And the like. Also, titanium oxide, silica,
Fine powders such as metal oxides exemplified by alumina, zirconium oxide, tin oxide and indium oxide, or metal sulfides and metal nitrides may be added. The undercoat layer can be formed using a suitable solvent, coating method as described above for the photosensitive layer. Further, as the undercoat layer of the present invention, a metal oxide layer formed by, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful. In addition to this, the undercoat layer of the present invention is provided with Al ₂ O ₃ by anodic oxidation, an organic substance such as polyparaxylylene (parylene),
Those provided with an inorganic filler such as SiO, SnO ₂ , TiO ₂ , ITO, CeO ₂ by a vacuum thin film forming method can also be used favorably. The thickness of the undercoat layer is 5 μm or less, more preferably 1 μm or less.
About 5 μm is appropriate. In all of these cases, as a dispersion solvent when forming a layer containing a filler, methyl ethyl ketone, acetone, methyl isobutyl ketone, ketones of cyclohexanone, dioxane, tetrahydrofuran, ethers such as ethyl cellosolve,
Aromatics such as toluene and xylene, chlorobenzene,
Halogen such as dichloromethane and esters such as ethyl acetate and butyl acetate are used, and are dispersed and pulverized using a ball mill, a sand mill, a vibration mill or the like. As a coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

(9) Electrophotographic Apparatus and Process Cartridge The overall configuration of the electrophotographic apparatus and the process cartridge using the photosensitive member is the same as that shown in FIGS. 1 to 3 for the electrophotographic apparatus. be able to. In the case of an electrophotographic apparatus using the photoconductor (see FIG. 1), the photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. Charger 3, pre-transfer charger 7, transfer charger 1
0, separation charger 11, charger 1 before cleaning
For 3, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used.

As the transfer means, generally, the above-mentioned charger can be used. However, as shown in FIG. 1, a combination of a transfer charger and a separation charger is effective. Light sources such as the image exposure unit 5 and the neutralizing lamp 2 include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp,
Light emitting diode (LED), semiconductor laser (LD),
A general light-emitting material such as electroluminescence (EL) can be used. To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. Also, 4
When an LD or LED having an oscillation wavelength in the range of 00 to 450 nm is used, the beam system of the writing light source is 1200
10 to achieve high resolution equivalent to ~ 2400 dpi
It is preferably from 30 to 30 μm. Such a light source or the like irradiates the photoreceptor with light by providing a transfer step, a charge removal step, a cleaning step, or a pre-exposure step using light irradiation in addition to the step shown in FIG.

[0069] The toner developed on the photosensitive member 1 by the developing unit 6 is being transferred onto the transfer sheet 9, not all are transferred, also caused toner remaining on the photosensitive member 1. Such toner is removed from the photoconductor by the fur brush 14 and the blade 15. Cleaning may be performed only with a cleaning brush,
As the cleaning brush, a known brush such as a fur brush or a mag fur brush is used.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrostatic detection fine particles), a positive image can be obtained, and if it is developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to such a developing unit.
In addition, a known method is used for the charge removing means. As another example of the electrophotographic process using the photoreceptor of the present invention, the same one as shown in FIG. 2 can be shown. In this case, the photoconductor of the present invention described above is used as the photoconductor 21.

The above-described electrophotographic process is an example of the embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 4, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or the image exposure and the erasing of the neutralization light may be performed from the support side. On the other hand, the light irradiation step includes image exposure,
Although the pre-cleaning exposure and the static elimination exposure are illustrated, the photosensitive member may be irradiated with light by providing other pre-transfer exposure, pre-exposure of image exposure, and other known light irradiation steps. The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, or may be incorporated in the apparatus in the form of a process cartridge. Although there are many shapes and the like of the process cartridge, a general example is shown in FIG. In this case, the photoconductor of the present invention is used as the photoconductor 16.

Next, the electrophotographic photosensitive member according to the present invention, an electrophotographic apparatus and a process cartridge using the same, and an electrophotographic method will be described in detail.

(1) First protective layer and second protective layer As the resin used for the first protective layer, a polyamide resin soluble in an alcohol solvent can be used. Although it is not particularly limited as polyamide, for example, CM8000 manufactured by Toray Co., Ltd. used in this example is preferably used. Further, as the solvent, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, butyl alcohol and the like are preferably used. The thickness of the first protective layer is 0.1 μm to 2 μm.
m, more preferably 0.5 μm to 1 μm. If the thickness is 0.1 μm or less, the effect of maintaining the interface between the photosensitive layer and the protective layer, which is the object of the present invention, may be lost. is there.

As the resin used for the second protective layer,
Desirable is a resin that does not elute into the first protective layer described above, that is, a resin that is insoluble in an alcohol-based solvent. Although not particularly limited, for example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin , Alkyd resin, polycarbonate resin, silicone resin, addition polymerization type resin such as melamine resin, polyaddition type resin, polycondensation type resin, and copolymer resin containing two or more of repeating units of these resins, for example, chloride Insulating resins such as vinyl-vinyl acetate copolymer, styrene-acrylic copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and poly-N
And high molecular organic semiconductors such as vinyl carbazole. These binders can be used alone or as a mixture of two or more. Further, as the material used for the second protective layer, ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, polyacetal, polyamideimide,
Polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, AS
Resins such as resins, butadiene-styrene copolymers, polyvinyl chloride, polyvinylidene chloride resins, and fluorine resins such as polytetrafluoroethylene. As a method for forming the protective layer, a normal coating method is employed. The thickness of the second protective layer is suitably about 1 to 15 μm, particularly preferably about 3 to 10 μm. If the thickness is 1 μm or less, the effect of improving durability, which is the object of the present invention, may be lost.
This is because there is a risk of causing a decrease in resolution, a decrease in sensitivity, and an increase in accumulated charge. By setting the film thickness in this range, both resolution and durability can be achieved. a-C formed by further more vacuum thin-film forming method in addition, a known material such as a-SiC may be used as the second protective layer.

(2) Filler In the present invention, by including a filler in the protective layer, mechanical durability can be improved. It is a known fact that the surface hardness is improved when a resin containing a filler is provided in the protective layer. That is, by simultaneously providing the resin and the filler used for the protective layer in the present invention as the protective layer of the photoreceptor, the wear resistance is further improved, and high image quality is maintained. A durable and highly sensitive electrophotographic photoreceptor can be obtained.

(3) Filler Type, Amount, etc. As the filler used in the protective layer of the present invention, any of the various fillers described above can be used. The average particle size of the filler is 0.05 to 1.0 μm, preferably 0.0
Pulverization and dispersion to 5 to 0.8 μm are preferred. If the average particle size is less than 0.05 μm, the particle size is too small, and improvement in wear resistance cannot be expected. On the other hand, if the average particle size is larger than 0.8 μm, the irregularities on the surface containing the filler become large, and the filler damages the cleaning blade, resulting in poor cleaning. Dispersion solvents include methyl ethyl ketone, acetone, methyl isobutyl ketone, ketones of cyclohexanone, dioxane, tetrahydrofuran,
Ethers such as ethyl cellosolve, aromatics such as toluene and xylene, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate are used. When a pulverizing step is added, a ball mill, a sand mill, a vibration mill or the like is used. As a coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

(4) Electron Transporting (Transferring) Material A conventionally known electron transporting (transferring) material is added to the protective layer containing the filler to impart an electron transporting function. As the conventionally known electron transporting materials to be added, the various materials described above can be exemplified.

The content of the electron transporting material in the protective layer is as follows:
The content is preferably in the range of 20 to 100 parts by weight, more preferably 50 to 70 parts by weight, based on 100 parts by weight of the binder resin. If the amount is 20 parts by weight or less, the function of electron transfer in the protective layer becomes insufficient, and if the amount is 100 parts by weight or more, the film-forming property is reduced, and the durability may be further reduced.

(5) Antioxidant Next, the antioxidant which is an essential component of the present invention will be described. The antioxidant may be added to the photosensitive layer and the protective layer, or to any of the protective layers. The use of an antioxidant in a photoreceptor generally has an effect on preventing a decrease in chargeability. It is known that the decrease in charge has a correlation with the charge generation layer due to the influence of acidic gases such as NOx and ozone generated during charge. In particular, in a layer configuration in which the charge generation layer, which is one of the layer configurations of the present invention, is laminated on the charge transport layer, the layer is susceptible to hazards such as acidic gas, and therefore, because of the development of oxidation resistance, the use of an antioxidant Although an antioxidant may be added directly to the charge generation layer, it is effective to add the antioxidant to the charge generation layer and add it to the charge generation layer so as to penetrate the charge generation layer. . The oxidation resistance mechanism of the antioxidant cannot be theoretically predicted as in the so-called one-electron transfer. This is presumably because this reaction mechanism often involves a chemical reaction. Therefore, selection of antioxidants is often based on experience, and it is often seen that two or more antioxidants are used in combination. However, when the amount used increases, there is a concern that the residual potential may increase. Further, an antioxidant may be used as a plasticizer in the charge transport layer for the purpose of improving crack resistance and the like. The charge transporting layer contracts when the organic solvent is dried by wet coating.
In this step, internal stress is accumulated in the charge transport layer. This internal stress appears as a crack in the charge transport layer when stress is applied from the outside. The use of antioxidants
It is also effective in improving such mechanical properties of the charge transport layer. In addition, antioxidants are classified as follows according to their functions and actions. Chain reaction initiator inhibitor, a radical chain reaction inhibitor and a peroxide decomposer.

The chain initiation reaction is caused by various factors such as light or heat in this case, and examples of the inhibitors include ultraviolet absorbers and light stabilizers, metal deactivators, and ozone deterioration inhibitors. The ultraviolet absorber and the light stabilizer can be expected to have an effect of preventing a chain reaction by binding to radicals generated by semiconductor laser light as writing light in the image exposure means, and an effect of suppressing generation of radicals.
400 to 45 as writing light in the image exposure means.
When using a semiconductor laser light having a wavelength of 0 nm,
It is expected to combine with the radicals generated by the semiconductor laser light to prevent the chain reaction, and to absorb the excess light energy due to the shortening of the writing light and convert it to lower energy, thereby suppressing the generation of radicals. it can. The metal deactivator reacts with the metal ion to form a complex, inactivates the metal, and suppresses the degradation promoting action of the metal. The ozone deterioration inhibitor has the effect of suppressing the deterioration of the photoreceptor due to ozone generated during charging by selectively reacting with ozone or ozonide or a precursor generated by ozone.

The radical chain reaction inhibitor traps the generated radical and stops the radical chain reaction. Representative examples include phenol-based, hydroquinone-based antioxidants, and amine-based antioxidants. Among the phenolic antioxidants, hydroquinone and the like are excellent in antioxidant capacity of rapid short-term, whereas 2,6-di -t- butyl -p- cresol - Le (BHT), butylated hydroxy anisole Seo - Le (B
Hindered phenolic compounds such as HA) can be expected to have an antioxidant effect over a long period of time. Since hindered phenolic compounds oxidation product hardly colored, clear that is very useful, especially semiconductor laser beam having a wavelength of 400~450nm as an antioxidant of the electrophotographic photosensitive member to be used as writing light Became. On the other hand, amine-based antioxidants are superior to hindered phenol-based compounds in antioxidant ability, but since oxidation products are often colored, attention must be paid to the amount used. These radical chain reaction inhibitors exhibit strong oxidation resistance especially to charge transport materials.
The peroxide decomposing agent has a function of decomposing a peroxide (peroxide) caused by ozone generated at the time of charging into an inactive compound to cut a contribution to a chain reaction. The peroxide decomposers include sulfur antioxidants and phosphoric antioxidants. These antioxidants are effective in suppressing the increase in oxidation, and have the ability to regenerate oxidized phenolic antioxidants. Also have. It is more preferable to use a radical chain reaction inhibitor in combination. As described above, according to the present invention, it has been found that these antioxidants are extremely useful.

The following are specific examples of these antioxidants. Among the chain reaction initiation inhibitors, phenyl salicylate as an ultraviolet absorber and a light stabilizer,
Monoglycol salicylate, 2-hydroxy-4-methoxybenzophenone, 2- (2'-hydroxy-5 '
-Methylphenyl) benzotriazole, resorcinol monobenzoate and the like. Examples of the metal deactivator include N-salicyloyl-N'-aldehyde hydrazine, N, N'-diphenyloxamide and the like. As the ozone deterioration inhibitor, 6-ethoxy-2,2,2
4-trimethyl-1,2-dihydroquinoline, N-phenyl-N′-isopropyl-p-phenylenediamine and the like. Among the phenolic antioxidants among the radical chain reaction inhibitors, monophenolic compounds include 2,6-di-t-butyl-p-cresol,
2,6-di-t-butylphenol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di-t-butyl-4- 2,2'-methylene-bis- as a bisphenol-based compound such as hydroxyphenyl) propionate
(4-methyl-6-t-butylphenol), 2,2 ′
-Methylene-bis- (4-ethyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t
-Butylphenol), 4,4'-butylidenebis-
(1,3-Tris- (2) is a polymer phenolic compound such as (3-methyl-6-t-butylphenol).
-Methyl-4-hydroxy-5-t-butylphenyl)
Butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl)
Benzene, tetrakis- [methylene-3- (3 ′, 5 ′)
-Di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3'-bis (4'-hydroxy-3'-t-butylphenyl) butyric acid] cricol ester, And tocopherols. In addition, hydroquinones such as 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, and 2-t
-Octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone and the like.

As the amine antioxidant, phenyl-β
-Naphthylamine, α-naphthylamine, phenothiazine, N, N′-diphenyl-p-phenylenediamine and the like. Among the peroxide decomposers, dilauryl-3,3'-thiodipropionate and distearyl-3,3'-thiodipropionate are used as sulfur-based antioxidants.
G, ditetradecyl-3,3'-thiodipropione
And laurylstearylthiodipropionate, dimyristylthiodipropionate, 2-mercaptobenzimidazole and the like. Examples of the phosphorus antioxidants include triphenylphosphine, tri (nonylphenyl) phosphine, tri (dinonylphenyl) phosphine, tricresylphosphine, tri (2,4-dibutylphenoxy) phosphine, tridecylphosphine, and tridecylphosphine. Octadecylphosphine and the like. These compounds are known as antioxidants for rubber, plastics, oils and the like, and their details are described in Antioxidant Handbook (Taiseisha). Also, commercially available products can be easily obtained. The addition amount of the antioxidant in the present invention is 0.05 to 100 parts by weight, preferably 0.1 to 30 parts by weight based on 100 parts by weight of the charge transporting material.

(6) Description of Layer Structure The layer structure of the photoreceptor of the present invention is as described in claims 10 to 17 above.
Can have a layer configuration similar to that shown for
The cross-sectional views are shown in FIGS. The photoreceptor of the present invention is obtained by forming the protective layer on the photosensitive layer into two layers, that is, using a solvent having low compatibility with the resin used in the photosensitive layer, and removing the resin soluble in the solvent. After laminating a thin film on the photosensitive layer as the first protective layer, a solvent having low compatibility with the resin used for the first protective layer is used, and a resin soluble in the solvent is applied to the second protective layer. By laminating on the first protective layer as, and in these protective layers filler,
It comprises an electron transfer material and an antioxidant. An antioxidant may also be used in the photosensitive layer. The photoconductor of FIG.
A charge transport layer 5 and a charge generation layer 4 are sequentially laminated on a conductive support 1 to provide a photosensitive layer 2. A first protective layer 6 and a second protective layer 7 are sequentially laminated on the photosensitive layer to form a protective layer. It is provided.

In the single-layer photoreceptor shown in FIG. 6, a photosensitive layer 2 'in which a charge generating substance 3 is dispersed in a charge transport medium is provided on a conductive support 1, and a first protective layer is provided on the photosensitive layer. 6, a second protective layer 7 is sequentially laminated to provide a protective layer.

Here, the photosensitive member in FIG. 5 is a photosensitive layer 2 comprising a charge transport layer 5 having a charge transport medium on a conductive support 1 and a charge generating layer 4 mainly composed of a charge generating substance 3.
Is provided. Here, the substance having the charge transporting ability used for the charge transporting medium 5 includes the aforementioned N
o. 1 to No. Various hole transporting substances shown by 18 can be mentioned. Further, examples of the charge generating substance include the various substances described above.

In the case where a photoreceptor is prepared using the above-described layer constitution and substance, there are preferable ranges for the film thickness and the ratio of the substance. In the case of the reverse layer photoconductor <function-separated type (conductive support 1 / charge transport layer 5 / charge generation layer 4)>, a binder is optionally used in the charge generation layer 4, and in that case, the binder is used. The ratio of the charge generating substance 3 to the agent is preferably 20% by weight or more, and the film thickness is preferably 0.01 to 5 μm. In the charge transport layer, the ratio of the charge transport material to the binder is 20 to 200.
It is preferable that the weight% and the film thickness be 5 to 100 μm. Or it may form a charge transport layer 5 on its own when using a polymer charge transport material. Further, the charge generation layer preferably contains a charge transporting substance, which has the effect of suppressing residual potential and improving sensitivity. In this case, the charge transport material is 20 to 2 with respect to the binder.
It is preferred that the content be contained at 00% by weight. In the case of a single-layer type photoreceptor, the ratio of the charge generating substance 3 to the binder resin in the photosensitive layer is 5 to 95% by weight, and the film thickness is 10 to 1%.
It is preferably set to 00 μm. When combined with a charge transport material, the ratio of the charge transport material to the binder resin is preferably from 30 to 200% by weight. Alternatively, the photosensitive layer may be formed of a polymer type charge transporting material and a charge generating material 3, and the ratio of the charge generating material 3 to the polymer type charge transporting material is 5 to 5.
Preferably, the thickness is 95% by weight and the film thickness is 10 to 100 μm.

(7) Description of Each Material, etc. In the production of the photoreceptor of the present invention, examples of the conductive support include those described above. In order to actually produce the photoreceptor shown in FIG. 5 of the present invention, after forming the charge transport layer 5 on the conductive support 1, the charge generation layer 4 may be formed. By forming the above-mentioned protective layers 6 and 7 on the charge generation layer 4 of the photoreceptor thus obtained, the photoreceptor shown in FIG. 5 can be produced. In addition, to produce the photoreceptor shown in FIG. 6, fine particles of the charge generating substance 3 and a filler and an electron transfer material are dispersed in a solution dissolved in a charge transporting substance and a binder. What is necessary is just to apply | coat on body 1, and to dry, and to form photosensitive layer 2 '. The thickness of the photosensitive layer 2 ′ is 3 to 100 μm, preferably 5 to 40 μm. The amount of the binder in the photosensitive layer 2 'is 40 to 90% by weight, and the amount of the charge generating substance 3 in the photosensitive layer 2' is 0.1 to 50% by weight, preferably 1 to 20% by weight. It is.

(8) Other Additives, Subbing Layer, etc. In all the constitutions of the electrophotographic photosensitive member according to the present invention shown in FIGS. 5 and 6, between the conductive support 1 and the photosensitive layers 2, 2 '. Can be provided with an undercoat layer. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving coating properties of the upper layer, reducing residual potential, and the like. The undercoat layer generally contains a resin as a main component. However, considering that these resins are coated thereon with a photosensitive layer using a solvent, the resin may be a resin having high resistance to dissolution in general organic solvents. desirable. Examples of such a resin include the various resins described above. In such resins, a plasticizer can be further added to the binder. The undercoat layer can be formed using a suitable solvent, coating method as described above for the photosensitive layer. Further, as the undercoat layer of the present invention, a metal oxide layer formed by, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like is also useful. In addition to this, the undercoat layer of the present invention is provided with Al ₂ O ₃ by anodic oxidation, an organic substance such as polyparaxylylene (parylene),
Those provided with an inorganic filler such as SiO, SnO ₂ , TiO ₂ , ITO, CeO ₂ by a vacuum thin film forming method can also be used favorably. The thickness of the undercoat layer is 5 μm or less, more preferably 1 μm or less.
About 5 μm is appropriate. In all of these cases, as a dispersion solvent when forming a layer containing a filler, methyl ethyl ketone, acetone, methyl isobutyl ketone, ketones of cyclohexanone, dioxane, tetrahydrofuran, ethers such as ethyl cellosolve,
Aromatics such as toluene and xylene, chlorobenzene,
Halogen such as dichloromethane and esters such as ethyl acetate and butyl acetate are used, and are dispersed and pulverized using a ball mill, a sand mill, a vibration mill or the like. As a coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

(9) Electrophotographic Apparatus and Process Cartridge The overall configuration of the electrophotographic apparatus and the process cartridge using the photosensitive member is the same as that shown in FIGS. 1 to 3 for the electrophotographic apparatus. be able to. In the case of an electrophotographic apparatus using the photoconductor (see FIG. 1), the photoconductor 1 has a drum shape, but may have a sheet shape or an endless belt shape. Charger 3, pre-transfer charger 7, transfer charger 1
0, separation charger 11, charger 1 before cleaning
For 3, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used.

As the transfer means, generally, the above-mentioned charger can be used. As shown in FIG. 1, it is effective to use a transfer charger and a separation charger in combination. Light sources such as the image exposure unit 5 and the neutralizing lamp 2 include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp,
Light emitting diode (LED), semiconductor laser (LD),
A general light-emitting material such as electroluminescence (EL) can be used. To irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. Also, 4
When an LD or LED having an oscillation wavelength in the range of 00 to 450 nm is used, the beam system of the writing light source is 1200
10 to achieve high resolution equivalent to ~ 2400 dpi
It is preferably from 30 to 30 μm. Such a light source or the like irradiates the photoreceptor with light by providing a transfer step, a charge removal step, a cleaning step, or a pre-exposure step using light irradiation in addition to the step shown in FIG.

The toner developed on the photosensitive member 1 by the developing unit 6 is transferred to the transfer paper 9, but not all of the toner is transferred, and toner remaining on the photosensitive member 1 is generated. Such toner is removed from the photoconductor by the fur brush 14 and the blade 15. Cleaning may be performed only with a cleaning brush,
As the cleaning brush, a known brush such as a fur brush or a mag fur brush is used.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrostatic detection fine particles), a positive image can be obtained, and if it is developed with toner of positive (negative) polarity, a negative image can be obtained. A known method is applied to such a developing unit.
In addition, a known method is used for the charge removing means. As another example of the electrophotographic process using the photoreceptor of the present invention, the same one as shown in FIG. 2 can be shown. In this case, the photoconductor of the present invention described above is used as the photoconductor 21.

The above-described electrophotographic process exemplifies the embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 2, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or the image exposure and the irradiation of the charge removing light may be performed from the support side. On the other hand, the light irradiation step includes image exposure,
Although the pre-cleaning exposure and the static elimination exposure are illustrated, the photosensitive member may be irradiated with light by providing other pre-transfer exposure, pre-exposure of image exposure, and other known light irradiation steps. The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, or may be incorporated in the apparatus in the form of a process cartridge. Although there are many shapes and the like of the process cartridge, a general example is shown in FIG. In this case, the photoconductor of the present invention is used as the photoconductor 16.

[0095]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the inventions according to claims 1 to 5 according to the present invention will be described with reference to embodiments, but the present invention is not limited by these embodiments. All parts are parts by weight.

Example 1 As a charge transport material, 4-N, N-ditolylamino-α-
10 parts of phenylstilbene and 10 parts of a polycarbonate resin [Panelite C-1400 manufactured by Teijin Ltd.] are dissolved in tetrahydrofuran, and the coating solution for the hole transport layer is applied on a nickel plate support by a doctor blade, and is heated at 80 ° C.
And then dried at 130 ° C for 20 minutes to a thickness of 10
A μm hole transport layer was formed. Then, the following structural formula (3
2) 7.5 parts of bisazo compound and 5.0 parts of a phenoxy resin [PKHH manufactured by Union Carbide Co., Ltd.] of 1.5% methyl ethyl ketone / cyclohexanone (4 /
1) 833 parts of the solution were pulverized and mixed in a ball mill, and the resulting dispersion was placed on the intermediate layer with a wet gap of about 35 μm.
Apply with a doctor blade and dry naturally.
A 5 μm charge generation layer was formed.

Embedded image

Next, the above formula (5) is used as an electron transport material.
And a polycarbonate resin as a binder resin (PANLIGHT TS-205 manufactured by Teijin Limited)
0) 6 parts and silica fine particles [KMPX manufactured by Shin-Etsu Chemical Co., Ltd.]
100] 2 parts were dissolved in tetrahydrofuran, applied on the charge generation layer, dried at 130 ° C. for 20 minutes, and dried to a thickness of 5
A μm surface protective layer was formed. In order to measure the volume resistance of the surface protective layer and the binder, the same composition as the surface protective layer and a polycarbonate resin (Panlite TS-205 manufactured by Teijin Limited) having a thickness of 10 μm were formed on an Al plate having a thickness of 1 mm.
0) was applied, and dried at 130 ° C. for 30 minutes to prepare a sample for volume resistance measurement. Volume resistance is J
Performed with a ring electrode in accordance with ISK6911 5.13 resistivity measurement. The volume resistances of the surface protective layer and the binder measured using an HP 4339A high resistance meter and HP16008B resistivity cell manufactured by HP Co. were 1.2 × 10 ¹⁵ Ω · cm and 1.5 × 10 5
It was ¹⁶ Ω · cm. The photoconductor film thus obtained was wound around a metal drum to prepare an electrophotographic photoconductor.
The obtained electrophotographic photosensitive member, a charging roller as a charging unit,
An optical system capable of adjusting the beam system with an aperture by mounting a semiconductor laser having an oscillation wavelength of 405 nm as a light source as an image exposure means, and an image forming experiment machine equipped with a two-component developing unit and a pattern generator as a developing means, and 30 μm in size.
The isolated dots obtained by the beam system were formed on a photoreceptor, transferred to an adhesive tape, read by a CCD camera, and analyzed. The initial charging potential of the photoconductor is 60
The operation was performed at 0 V, and a magnetic toner having an average particle diameter of 6 μm was used. The shape and reproducibility of the isolated dot were visually evaluated in three stages. Table 1 shows the results. Further, the above-mentioned electrophotographic photosensitive drum was mounted on the electrophotographic process shown in FIG.
(Image writing with a polygon mirror), and a probe of a surface voltmeter was inserted so that the surface potential of the photoconductor immediately before development could be measured. Printing was continuously performed on 10,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 10,000 sheets. Table 2 shows the results.

Example 2 In Example 1, a phenoxy resin [PKH manufactured by Union Carbide Co., Ltd.] was used instead of a polycarbonate resin (Panlite TS-2050 manufactured by Teijin Limited) as a binder resin.
H] and silica fine particles [KM manufactured by Shin-Etsu Chemical Co., Ltd.]
A photoconductor was prepared in the same manner except that alumina particles [RFY-C manufactured by Nippon Aerosil Co., Ltd.] were used instead of [PX100]. At this time, the volume resistances of the surface protective layer and the binder were 4.8 × 10 ¹⁵ Ω · cm and 3.8 × 10 ^{16, respectively.}
Ω · cm. Tables 1 and 2 show the results of image analysis performed in the same manner as in Example 1 by assembling the photoconductor.

Example 3 A photoconductor was prepared in the same manner as in Example 2, except that polyvinyl butyral resin [XYHL manufactured by Union Carbide Co., Ltd.] was used as the binder. At this time, the volume resistances of the surface protective layer and the binder were 4.8 × 10 ¹⁵ Ω · c, respectively.
m, 4.3 × 10 ¹⁶ Ω · cm. Tables 1 and 2 show the results of image analysis performed in the same manner as in Example 1 by assembling the photoconductor.

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 2, except that a polyamide resin [Amilan CM-8000 manufactured by Toray Industries, Inc.] was used as a binder. At this time, the volume resistances of the surface protective layer and the binder were 1.0 × 10 ¹³ Ω · cm and 4.2, respectively.
× 10 ¹³ Ω · cm. Tables 1 and 2 show the results of image analysis performed in the same manner as in Example 1 by assembling the photoconductor.

[0101]

[Table 1] ：: Reproduced with good dot quality when dot size is 40 μm or less △: Reproduced with dot size 40 μm or less, but poor in contrast and poor reproducibility ×: Dot size exceeds 40 μm or dot formation is unstable

[0102]

[Table 2]

Example 4 and Comparative Example 2 Evaluation was made in the same manner as in Example 1 except that the average particle size of the toner used was changed. Table 3 shows the results.

[0104]

[Table 3]

Comparative Examples 3 and 4 Evaluation was made in the same manner as in Example 1 except that the average beam diameter of the light source was changed. Table 4 shows the results.

[0106]

[Table 4]

As described above, according to the present invention, it is possible to form an image with minute dots with good reproducibility, and since it has excellent printing durability, it is possible to form an image with an ultra-high resolution of 1200 dpi or 2400 dpi, and to have a small size. It is possible to provide an electrophotographic apparatus that is high-speed and has a low component replacement frequency.

The invention of claims 6 to 9 according to the present invention will be described below with reference to examples, but the present invention is not limited by these examples. All parts are parts by weight.

Example 5 As a charge transporting material, 4-N, N-ditolylamino-α-
10 parts of phenylstilbene and 10 parts of a polycarbonate resin [Panelite C-1400 manufactured by Teijin Ltd.] are dissolved in tetrahydrofuran, and the coating solution for the hole transport layer is applied on a nickel plate support by a doctor blade, and is heated at 80 ° C.
And dried at 130 ° C for 20 minutes to a thickness of 20
A μm hole transport layer was formed. Next, 7.5 parts of a bisazo compound represented by the above structural formula (32) and a phenoxy resin [PKHH manufactured by Union Carbide Co., Ltd.] 5.0
Parts of 833 parts of a 1.5% methyl ethyl ketone / cyclohexanone (4/1) solution were ground and mixed in a ball mill,
The obtained dispersion is applied to the intermediate layer with a wet gap of about 3
It was applied with a doctor blade at 5 μm and dried naturally to form a charge generation layer. Next, 3 parts of the compound represented by the above formula (5) as an electron transporting material and a polycarbonate resin as a binder resin (Panlite TS- manufactured by Teijin Limited)
2050) 6 parts and silica fine particles [K manufactured by Shin-Etsu Chemical Co., Ltd.
MPX100] 2 parts in tetrahydrofuran,
The composition was applied on the charge generation layer and dried at 130 ° C. for 20 minutes to form a surface protective layer having a thickness of 5 μm. The photoconductor film thus obtained was wound around a metal drum to prepare an electrophotographic photoconductor. The obtained electrophotographic photosensitive member, a charging roller as a charging unit, and an oscillation wavelength of 405 n as a light source as an image exposure unit
An isolated dot obtained with a 30 μm beam system by an imaging system equipped with an optical system equipped with a semiconductor laser of m and an aperture capable of adjusting the beam system, a two-component developing unit as a developing means, and a pattern generator is placed on the photoconductor. It was formed, transferred to an adhesive tape, read by a CCD camera, and image analyzed. The initial charging potential of the photoreceptor was set at 600 V, and magnetic toner having an average particle diameter of 6 μm was used. The shape and reproducibility of the isolated dot were visually evaluated in three stages. Table 5 shows the results. Further, the electrophotographic photosensitive drum was mounted in the electrophotographic process shown in FIG. 1 (however, the image exposure light source was an LD emitting light at 405 nm (image writing by a polygon mirror)), and immediately before development. A probe of a surface voltmeter was inserted so that the surface potential of the photoconductor could be measured. Printing was continuously performed on 10,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 10,000 sheets. Table 6 shows the results.

Examples 6 to 10 An image forming apparatus was prepared in the same manner as in Example 5 except that the thickness of the hole transport layer and the thickness of the surface protective layer were changed, and the shape of the isolated dots and the reproducibility were evaluated. went. In addition, a durability test using an actual machine was performed. The results are shown in Tables 5 and 6.

Comparative Examples 5 to 8 An image forming apparatus was manufactured in the same manner as in Example 5 except that the thickness of the hole transport layer and the thickness of the surface protective layer were changed, and the shapes of the isolated dots and the reproducibility were evaluated. went. In addition, a durability test using an actual machine was performed. The results are shown in Tables 5 and 6.

[0112]

[Table 5] ：: Reproduced with good contrast when dot size is 40 μm or less △: Reproduced with dot size 40 μm or less, but poor in contrast and poor reproducibility ×: Dot size exceeds 40 μm or dot formation is unstable

[0113]

[Table 6]

Example 11 and Comparative Example 9 Evaluation was made in the same manner as in Example 7, except that the average particle size of the toner used was changed. Table 7 shows the results.

[0115]

[Table 7]

Comparative Examples 6 and 7 Evaluation was made in the same manner as in Example 7 except that the beam diameter of the light source was changed. Table 8 shows the results.

[Table 8]

As described above, according to the present invention, an image with minute dots can be formed with good reproducibility, and since it has excellent printing durability, an image with an ultra-high resolution of 1200 dpi or 2400 dpi can be formed. Thus, it is possible to provide an electrophotographic apparatus in which component replacement is less frequent.

Next, embodiments of the present invention will be described.

Example 12 A coating solution for an undercoat layer, a coating solution for a charge transport layer, a coating solution for a charge generation layer, a coating solution for a first protective layer, The coating liquid for the second protective layer was sequentially applied and dried to form a 3.5 μm undercoat layer, a 20 μm charge transport layer, a 0.2 μm charge generation layer, a 0.5 μm first protective layer, A second protective layer having a thickness of 5 μm was formed to prepare a photoconductor. [Coating solution for undercoat layer] Alkyd resin (Beccosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals) 6 parts Melamine resin (Super Beckamine G-821-60, manufactured by Dainippon Ink and Chemicals) 4 parts Oxidation Titanium 40 parts Methyl ethyl ketone 50 parts This undercoat layer coating liquid is applied on an aluminum plate support with a doctor blade, and dried at 100 ° C. for 20 minutes to obtain a thickness of 3.
An undercoat layer of 5 μm was formed. [Coating solution for charge transport layer] Next, 4-
7 parts of N, N-ditolylamino-α-phenylstilbene and a polycarbonate resin [Panlite C- manufactured by Teijin Limited]
1400] Dissolve 10 parts in tetrahydrofuran, apply the coating solution for hole transport layer on the undercoat layer with a doctor blade, and dry at 80 ° C. for 2 minutes and then at 130 ° C. for 20 minutes to transport a hole having a thickness of 20 μm. A layer was formed.

[Coating Solution for Charge Generating Layer] Then, 7.5 parts of the bisazo compound represented by the structural formula (32) and a phenoxy resin [PKHH manufactured by Union Carbide Co., Ltd.] 5.0
Parts of 833 parts of a 1.5% methyl ethyl ketone / cyclohexanone (4/1) solution were ground and mixed in a ball mill,
The resulting dispersion was applied on the charge transport layer with a doctor blade at a wet gap of about 35 μm, and dried at 100 ° C. for 10 minutes to form a 0.2 μm thick charge generation layer. [First protective layer coating solution] Then, 2 parts of an alcohol solvent-soluble polyamide resin <CM8000 manufactured by Toray Industries Co., Ltd.> and 38 parts of a methanol / n-butanol (4/1) solution were prepared. A first protective layer coating solution diluted with a butanol (4/1) solution and applied at 2.5 wt% on the charge generation layer, dried at 100 ° C. for 10 minutes, and dried to a thickness of 0.5 μm; A first protective layer was formed. [Coating Liquid for Second Protective Layer] Finally, 3 parts of the compound represented by the above formula (4) as an electron transporting material and a polycarbonate resin as a binder resin (Panlite T manufactured by Teijin Limited)
S-2050) 6 parts and silica fine particles [KMPX100 manufactured by Shin-Etsu Chemical Co., Ltd.] 2 parts are dissolved in tetrahydrofuran, applied on the first protective layer, dried at 130 ° C. for 20 minutes, and dried to a thickness of 5 μm. 2 protective layers were formed. Thus, a photoreceptor was manufactured.

Example 13 Example 12 was carried out in the same manner as in Example 12, except that the material represented by the above formula (6) was used as the electron transporting material in the second protective layer.

Example 14 Example 12 was performed in the same manner as in Example 12, except that the material represented by the above formula (5) was used as the electron transporting material in the second protective layer.

Example 15 The same procedure as in Example 12 was carried out except that the charge generating material in the coating liquid for the charge generating layer in Example 12 was Y-type titanyl phthalocyanine, and the binder resin was a polyvinyl butyral resin.

Comparative Example 12 The same procedure as in Example 12 was carried out except that the material represented by the formula (3) was used as the electron transporting material in the second protective layer in Example 1.

Further, only the second protective layer film was formed on the polyester film by the same operation using the second protective layer coating solution. Second from above polyester film
Was peeled off, the transmission spectrum of the obtained second protective layer film was measured with a spectrophotometer, and the transmittance at each wavelength was obtained from the above equation (2). Table 9 shows the results.

[0126] short length of the resulting electrophotographic photosensitive member LD, L
The spectral sensitivity in the ED oscillation wavelength range was measured with EPA-8100 (manufactured by Kawaguchi Electric Works). Using a xenon lamp as a light source, spectroscopy was performed using a monochromator (manufactured by Nikon Corporation). First, the photoreceptor is moved to −800 by corona discharge.
(V) After the charging, the charging is stopped, and exposure with each monochromatic light is performed so that the surface potential is -800 (V).
From the irradiation light intensity (μW / cm ² ) of each wavelength to the exposure amount (μJ
/ Cm ² ) was calculated. The light attenuation potential difference 700 at this time
(V) was divided by the above exposure amount, and the obtained value was defined as a spectral sensitivity value (V · cm ² / μJ). However, since the potential decrease due to dark decay is included during light decay, the dark decay amount of each photoconductor was measured before measuring the light sensitivity, and each spectral sensitivity value was corrected using this value. Table 9 shows the results.

[0127]

[Table 9]

Table 9 shows that the electrophotographic photosensitive member of Comparative Example 12 of the second protective layer, which does not transmit monochromatic light of 400 to 450 nm in the short wavelength LD or LED oscillation wavelength region, does not exhibit sensitivity in this region. I understand. On the other hand, the second protective layers of the present invention (Examples 12 to 15) all show good light transmission characteristics in this region, and it can be seen that the electrophotographic photoreceptor has high sensitivity.

Example 16 0.5 g of the bisazo compound represented by the structural formula (32) used in Example 12 was added to polycarbonate Z (manufactured by Teijin Chemicals Ltd.).
10 g of solution (dissolved to a concentration of 10% by weight in tetrahydrofuran), 9 g of tetrahydrofuran
After ball milling together with the mixture, a 10% by weight polycarbonate solution was added so that the derivative mixture composition was 2% by weight, the PC-Z composition was 50% by weight, and the charge transporting material used in Example 12 was 28%. Then, a coating solution for a photosensitive layer was prepared. Further, the coating liquids for the first and second protective layers were prepared in the same manner as in Example 12, and these coating liquids were sequentially applied and dried in the same manner as in Example 12 to obtain a single-layer type having a thickness of 20 μm. An electrophotographic photoreceptor was prepared. Examples 12 to 1 below
The same evaluation as that of No. 5 is shown.

[0130]

[Table 10]

Example 17 and Comparative Example 13 The coating liquid used in Example 14 was sequentially applied to an aluminum cylinder and dried to produce a laminated photosensitive drum similar to that in Example 14 (Example 17). Photoconductor). A photosensitive drum of Comparative Example 12 was produced in the same manner as in Example 6, except that the coating solution for the photosensitive layer was changed to that of the comparative example. The above-described electrophotographic photosensitive drum was mounted in the electrophotographic process shown in FIG. 1 (however, the image exposure light source was an LD emitting light at 405 nm (image writing by a polygon mirror)). A probe for a surface electrometer was inserted so that the surface potential of the body could be measured. Printing was continuously performed on 10,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 10,000 sheets. Table 1 shows the results
It is shown in FIG.

[0132]

[Table 11]

In the present invention, the positively charged
By using a protective layer that efficiently transmits monochromatic irradiation light in a wavelength range of 0 to 460 nm, and by including a filler and an electron transfer material in these protective layers, a photoreceptor having both durability and sensitivity characteristics is achieved. We were able to. Further, since the protective layer transmits monochromatic irradiation light in the wavelength range of 390 to 460 nm, the wavelength of the writing light source in the image exposure means can be 400 to 400 by selecting the electron transfer material used in the protective layer.
High durability, high sensitivity electrophotographic photoreceptor that maintains high image quality for a long time in a process having an oscillation wavelength in a range of 450 nm and has no potential fluctuation even when used repeatedly, and an electrophotographic apparatus and process cartridge using the same Can be provided.

Next, embodiments of the present invention according to claims 21 to 36 will be described.

Example 18 1.5 parts of an oil-free alkyd resin (manufactured by Dainippon Ink and Chemicals, Beccolite M6401) and a melamine resin (manufactured by Dainippon Ink and Chemicals: Super Beckamine G-821) 1
Part, titanium dioxide [manufactured by Ishihara Sangyo Co., Ltd .: Taipe CR
-EL]] A mixture of 5 parts and 22.5 parts of 2-butanone was placed in a ball mill pot, and ball milling was performed using alumina balls having a diameter of 10 mm for 48 hours to prepare an intermediate layer coating liquid. This coating solution was applied on an aluminum cylinder to form an intermediate layer having a thickness of about 4 μm. Next, a coating liquid for a charge transport layer, a coating liquid for a charge generation layer, a coating liquid for a first protective layer, and a coating liquid for a second protective layer having the following composition are sequentially coated on the intermediate layer. By drying, a charge transport layer of 20 μm, a charge generation layer of 0.2 μm, a first protective layer of 0.5 μm, and a second protective layer of 5 μm were formed, whereby an electrophotographic photoreceptor of the present invention was produced. . [Coating solution for charge transport layer] Next, 4-
7 parts of N, N-ditolylamino-α-phenylstilbene and a polycarbonate resin [Panlite C- manufactured by Teijin Limited]
1400] 10 parts were dissolved in tetrahydrofuran, and the coating solution for hole transport layer was applied on the intermediate layer to a thickness of 20 parts.
A μm hole transport layer was formed. [Coating solution for charge generation layer] Next, 7.5 parts of a bisazo compound represented by the structural formula (32) and 5.0 parts of a phenoxy resin [PKHH manufactured by Union Carbide Co., Ltd.] 5.0 parts
833 parts of a 4% by weight methyl ethyl ketone / cyclohexanone (4/1) solution was pulverized and mixed in a ball mill, and the resulting dispersion was applied on the charge transport layer to form a 0.2 μm charge generation layer. [First protective layer coating solution] Then, 2 parts of an alcohol solvent-soluble polyamide resin <CM8000 manufactured by Toray Industries Co., Ltd.> and 38 parts of a methanol / n-butanol (4/1) solution were prepared. -A 2.5 wt% coating solution for a first protective layer diluted with a butanol (4/1) solution was applied on the charge generating layer to form a 0.5 µm first protective layer. [Coating Liquid for Second Protective Layer] Finally, 3 parts of the compound represented by the above formula (1) as an electron transporting material and a polycarbonate resin as a binder resin (Panlite T manufactured by Teijin Limited)
S-2050) 6 parts and silica fine particles [KMPX100 manufactured by Shin-Etsu Chemical Co., Ltd.] 2 parts, 2,6- as an antioxidant
0.03 parts of di-t-butyl-p-cresol was dissolved in tetrahydrofuran and applied on the first protective layer to form a 5 μm thick second protective layer.

Example 19 The same procedure as in Example 18 was carried out except that the charge generation material was changed to a Y-type oxotitanium phthalocyanine pigment and a polyvinyl butyral resin (BM-S manufactured by Sekisui Chemical Co., Ltd.) MEK solution in the coating solution for the charge generation layer of Example 18. In the same manner as in No. 18, an electrophotographic photosensitive member of the present invention was produced.

Example 20 An electrophotographic photoreceptor of the present invention was produced in the same manner as in Example 18, except that the antioxidant was changed to resorcinol monobenzoate in the coating liquid for the second protective layer in Example 18.

Example 21 Example 19 was repeated except that the binder resin of the second protective layer was changed to a polyarylate resin (U-6000, manufactured by Unitika) and the antioxidant was changed to 2,5-di-t-octylhydroquinone. In the same manner as in Example 19, an electrophotographic photosensitive member of the present invention was produced.

Example 22 The binder resin of the charge transport layer of Example 19 was changed to a polycarbonate resin (PCX-5, manufactured by Teijin Chemicals Ltd.), and the antioxidant 2,6-di-t-butyl-p was added to the charge transport layer. -An electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 19 except that 0.03 part of -cresol and 0.04 part of distearyl-3,3'-thiodipropionate were added.

Example 23 In the coating solution for the second protective layer in Example 19, the binder resin was changed to a polyarylate resin (U-600 manufactured by Unitika Ltd.).
0) and an electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 19 except that distearyl-3,3'-thiodipropionate was added as an antioxidant.

Example 24 The electrophotographic photosensitive composition of the present invention was prepared in the same manner as in Example 23 except that the filler was changed to titanium oxide fine particles (CR97, manufactured by Ishihara Sangyo Co., Ltd.) in the coating solution for the second protective layer in Example 23. The body was made.

Example 25 In the coating liquid for a charge transport layer of Example 24, 2,6-di-tert-butyl-p-cresol 0.0
All except that 3 parts and 0.04 part of N-phenyl-N'-isopropyl-p-phenylenediamine, and 17 parts of a polymer type charge transporting material represented by the following structural formula were dissolved in 100 parts of tetrahydrofuran. An electrophotographic photosensitive drum was manufactured in the same manner as in Example 19.

Embedded image

Comparative Examples 14 to 21 Coating solutions to which no antioxidant was added were prepared in Examples 18 to 25, respectively.
A photosensitive drum corresponding to No. 25 was produced.

As described above, the electrophotographic photosensitive drums produced in Examples 18 to 25 and Comparative Examples 14 to 21 are shown in FIG.
(Except that the image exposure light source was an LD with emission at 655 nm (polygon
Image writing with a mirror)) Also, a probe of a surface voltmeter was inserted so that the surface potential of the photoconductor immediately before development could be measured. Printing was continuously performed on 5,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 5,000 sheets. Table 12 shows the results.

[0145]

[Table 12]

Example 26 1.5 parts of an oil-free alkyd resin (manufactured by Dainippon Ink and Chemicals, Beccolite M6401) and a melamine resin (Super Beckamine G-821 manufactured by Dainippon Ink and Chemicals) 1
Part, titanium dioxide [manufactured by Ishihara Sangyo Co., Ltd .: Taipe CR
-EL]] A mixture of 5 parts and 22.5 parts of 2-butanone was placed in a ball mill pot, and ball milling was performed using alumina balls having a diameter of 10 mm for 48 hours to prepare an intermediate layer coating liquid. This coating solution was applied on an aluminum cylinder to form an intermediate layer having a thickness of about 4 μm. Next, a ball mixture of a mixture of 0.5 part of a Y-type oxotitanium phthalocyanine pigment, 0.9 part of a polycarbonate resin (manufactured by Teijin Chemicals Ltd .: PCX-5) and 8.1 parts of tetrahydrofuran was used. 50% by weight of a polycarbonate resin (manufactured by Teijin Chemicals Ltd .: PCX-5), 28% by weight of 4-N, N-ditolylamino-α-phenylstilbene as a charge transport material, 2,6 as an antioxidant
A charge transporting material, an antioxidant, and a 10% by weight polycarbonate resin solution were added so that the amount of di-t-butyl-p-cresol was 1% by weight based on the charge transporting material, and the mixture was sufficiently stirred and coated with a photosensitive layer. A liquid was prepared. After applying this coating solution, a photosensitive layer was formed so that the film thickness after drying was 15 μm, and a single-layer type electrophotographic photosensitive drum was prepared.

Example 27 The antioxidant in Example 26 was replaced with distearyl-3,
An electrophotographic photosensitive drum was prepared in the same manner as in Example 26 except that 3'-thiodipropionate was used.

Comparative Examples 22 and 23 Coating solutions to which no antioxidant was added were prepared in Examples 26 and 27, respectively.
A photoconductor drum corresponding to No. 27 was produced.

The electrophotographic photosensitive drums produced in Examples 26 and 27 and Comparative Examples 22 and 23 were mounted in the electrophotographic process shown in FIG. 3 (however, the image exposure light source emitted light at 655 nm). An LD (image writing by a polygon mirror) was used, and a probe of a surface voltmeter was inserted so that the surface potential of the photoconductor immediately before development could be measured. Printing was continuously performed on 5,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 5,000 sheets. Table 13 shows the results.

[0150]

[Table 13]

[0151] was used in place of the electron transport material of the second protective layer in Example 28 Example 22 to the compound represented by the formula (4), the electrophotographic photosensitive drum in the same manner as in Example 22 Produced.

Example 29 Example 29 was repeated except that the electron transporting material in the second protective layer was changed to the compound represented by the formula (6).
An electrophotographic photosensitive drum was produced in the same manner as in Example 2.

Comparative Example 24 An electrophotographic photoreceptor was prepared in the same manner as in Example 28 except that the electron transport material in the second protective layer was changed to the diphenoquinone derivative compound represented by the formula (3). A drum was made.

The electrophotographic photosensitive drums produced in Examples 28 and 29 and Comparative Example 24 were mounted in the electrophotographic process shown in FIG. 3 (however, the image exposure light source was 405 nm).
And a probe of a surface voltmeter was inserted so that the surface potential of the photoconductor immediately before development could be measured. Printing was continuously performed on 5,000 sheets, and the surface potentials of the image-exposed portion and the image non-exposed portion at that time were measured at the initial stage and after 5,000 sheets. Table 14 shows the results.

[0155]

[Table 14]

As can be seen from Tables 12, 13, and 14, the photosensitive members of Examples 18 to 27 of the present invention have the same Comparative Example 14 containing no antioxidant in any layer constitution.
As compared with the photoreceptors No. to No. 123, it can be understood that the electrophotographic photoreceptor has no potential fluctuation even in repeated use. Also,
The photoreceptors of Examples 28 and 29 use a compound that does not show absorption in the wavelength region when a writing light source in the wavelength region of 400 to 450 nm is used for the electron transfer material contained in the second protective layer. It was found that the electrophotographic photosensitive member had no potential fluctuation even when used repeatedly and had excellent mechanical and chemical durability.

In the present invention, by forming the protective layer on the photosensitive layer into two layers, that is, by using a solvent having low compatibility with the resin used in the photosensitive layer, the resin soluble in the solvent is removed. After laminating a thin film on the photosensitive layer as the first protective layer, a solvent having low compatibility with the resin used for the first protective layer is used, and the resin soluble in the solvent is subjected to the second protection. By laminating on the first protective layer as a layer, and by including a filler, an electron transfer material, and an antioxidant in these protective layers, and also by including an antioxidant in the photosensitive layer, durability is improved. A photosensitive member having both high sensitivity and sensitivity characteristics, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic device having the electrophotographic photosensitive member, and a process cartridge used in the electrophotographic device can be provided. Quality By taking this configuration is maintained for a long period of time, repeated no potential variation be used, high durability, electrophotographic method using highly sensitive electrophotographic photoreceptor and it electrophotographic apparatus, process cartridge Can be provided. Further, even when a writing light source in a wavelength region of 400 to 450 nm is used, an electrophotographic photoreceptor, an electrophotographic method, and an electrophotographic photoreceptor having no potential fluctuation even when repeatedly used and having excellent mechanical and chemical durability. A photographic device and a process cartridge for an electrophotographic device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating one example of an electrophotographic apparatus.

FIG. 2 shows a configuration diagram of another example of the electrophotographic apparatus.

FIG. 3 is a configuration diagram illustrating one example of a process cartridge.

FIG. 4 shows a schematic diagram of a transmission spectrum of a protective layer.

FIG. 5 is a diagram illustrating an example of a photoconductor.

FIG. 6 is an explanatory sectional view of another example of the photoconductor.

[Explanation of symbols]

 [FIGS. 1 to 3] 1, 21, 16 Photoconductor [FIGS. 5 to 6] 1 Conductive support 2, 2 'Photosensitive layer 3 Charge generating substance 4 Charge generating layer 5 Charge transport layer or charge transport medium 6th 1 protective layer 7 second protective layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 9/08 G03G 9/08 15/043 15/04 120 15/04 (72) Inventor Tomoyuki Shimada Tokyo 1-3-6 Nakamagome, Ota-ku Ricoh Co., Ltd. (72) Inventor Shinichi Kawamura 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Chiaki Tanaka Nakamagome, Ota-ku, Tokyo 1-3-6 Ricoh F-term in Ricoh Co., Ltd. (reference) 2H005 EA05 2H068 AA03 AA04 AA05 AA08 AA31 AA34 AA35 AA41 BA05 BA12 BB04 BB28 BB31 BB33 BB61 CA02 CA06 CA22 CA29 CA34 CA37 CA40 CA54 FA02 FA27 AB02 AB07 FB07 DA37

Claims (37)

[Claims] At least an electrophotographic photosensitive member, charging means,
In an electrophotographic apparatus equipped with image exposure means and development means, the average light beam diameter of the writing light source of the image exposure means is 10
電子 40 μm, the electrophotographic photosensitive member is composed of a photosensitive layer in which a hole transport layer, a charge generation layer, and a surface protective layer are laminated in this order on a conductive substrate, and the surface protective layer has a volume resistance of 10 ⁴ Ω.
-An electrophotographic apparatus characterized by being at least cm. 2. A binder tree used for the surface protective layer.
Fat volume resistance is 10 ^FiveΩ · cm or more
The electrophotographic apparatus according to claim 1. 3. The electrophotographic apparatus according to claim 1, wherein the surface protective layer contains a filler and an electron transport material. 4. The developing device according to claim 1, wherein said developing device uses a toner having an average particle diameter of 4 to 8 μm.
An electrophotographic apparatus according to any one of claims 1 to 3. 5. The wavelength of a writing light source of said image exposure means is 4
The electrophotographic apparatus according to any one of claims 1 to 4, wherein the electrophotographic apparatus is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range from 00 to 450 nm. 6. An electrophotographic photosensitive member, charging means,
In an electrophotographic apparatus equipped with an image exposure unit and a development unit, the wavelength of a writing light source of the image exposure unit is 400 to 45.
A semiconductor laser or light-emitting diode having an oscillation wavelength in the range of 0 nm, wherein the electrophotographic photoreceptor comprises a photosensitive layer in which a hole transport layer, a charge generation layer, and a surface protective layer are laminated on a conductive substrate in this order; The thickness of the transport layer is 5
An electrophotographic apparatus, wherein the thickness of the surface protection layer is 3 to 9 μm. 7. The electrophotographic apparatus according to claim 6, wherein the surface protective layer contains a filler and an electron transport material. 8. The developing device according to claim 6, wherein said developing device uses a toner having an average particle diameter of 4 to 8 μm.
Or the electrophotographic apparatus according to 7. 9. The image exposure means according to claim 6, wherein said writing light source has a beam diameter of 10 to 30 μm.
The electrophotographic apparatus according to any one of the above. 10. An electrophotographic photoreceptor having a photosensitive layer and a protective layer sequentially on a positively-charged conductive support directly or via an undercoat layer, wherein the protective layer has a thickness of 390 to 460 nm.
An electrophotographic photosensitive member that transmits monochromatic irradiation light in a wavelength region. 11. The electrophotographic photosensitive member according to claim 10, wherein said protective layer has a transmittance of 50% or more for monochromatic light in a wavelength range of 390 to 460 nm. 12. The electrophotographic photoconductor according to claim 10, wherein the protective layer contains an electron transport material and a filler. 13. The electrophotographic photoreceptor according to claim 10, wherein said protective layer comprises a first protective layer and a second protective layer. 14. The electrophotographic photoconductor according to claim 13, wherein the first protective layer uses a resin and a solvent other than a resin used for the photosensitive layer and a solvent that dissolves the resin. 15. The filler may be titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluororesin powder, polysiloxane. The electrophotographic photoreceptor according to any one of claims 12 to 14, wherein the electrophotographic photoreceptor is any one or a mixture of a resin-based resin powder, a polyethylene-based resin powder, and a graft copolymer having a core-shell structure. 16. The photosensitive layer according to claim 10, wherein the photosensitive layer is formed on the conductive support directly or via an intermediate layer in the order of a charge transport layer and a charge generation layer. An electrophotographic photoreceptor as described in Crab. 17. The electrophotographic photoreceptor according to claim 10, wherein the photosensitive layer is a single-layer type containing a charge transport material and a charge generation material in a binder resin. . 18. The electrophotographic photosensitive member according to claim 10, wherein at least the electrophotographic photosensitive member, a charging unit, an image exposing unit, a developing unit, and a transfer unit are mounted. An electrophotographic apparatus, comprising: 19. The electrophotographic apparatus according to claim 18, wherein a wavelength of a writing light source in said exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 400 to 450 nm. 20. At least one unit selected from the group consisting of an electrophotographic photosensitive member, a charging unit, an image exposing unit, a developing unit, a transfer unit and a cleaning unit is integrally supported,
A process cartridge configured to be detachable from an electrophotographic apparatus main body, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to any one of claims 10 to 17. 21. The process cartridge according to claim 20, wherein a wavelength of a writing light source in said image exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 400 to 450 nm. 22. An electrophotographic photoreceptor having an organic photoconductive photosensitive layer operating under positive charge and a protective layer, wherein the protective layer contains an electron transporting material and a filler, and the photosensitive layer and / or the protective layer is oxidized. An electrophotographic photoreceptor containing an inhibitor. 23. The electron according to claim 22, wherein the photosensitive layer is formed by laminating a charge transport layer and a charge generation layer on a conductive support directly or via an intermediate layer in this order. Photoreceptor. 24. The electrophotographic photosensitive member according to claim 22, wherein the photosensitive layer is a single layer type containing a charge transport material and a charge generation material in a binder resin. 25. The electrophotographic photosensitive member according to claim 22, wherein said protective layer is a protective layer comprising a first layer and a second layer sequentially laminated on the photosensitive layer. body. 26. The electrophotographic photoreceptor according to claim 22, wherein the resin used for the protective layer is a protective layer containing a polyamide resin soluble in an alcohol-based solvent. 27. The electrophotographic photoconductor according to claim 26, wherein the resin used for the second protective layer is a resin other than a polyamide resin soluble in an alcohol solvent. 28. The antioxidant is at least one selected from a chain reaction initiation inhibitor classified as an ultraviolet absorber, a light stabilizer, a metal deactivator, and an ozone deterioration inhibitor. Item 29. The electrophotographic photosensitive member according to any one of Items 22 to 27. 29. The antioxidant is at least one selected from radical chain reaction inhibitors classified as phenolic, hydroquinone-based antioxidants and amine-based antioxidants. The electrophotographic photosensitive member according to any one of the above. 30. The antioxidant according to claim 22, wherein the antioxidant is at least one selected from peroxide decomposers classified as sulfur antioxidants and phosphorus antioxidants. 2. The electrophotographic photoreceptor of claim 1. 31. The filler is titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluorine resin powder, polysiloxane. The electrophotographic photoreceptor according to any one of claims 22 to 30, wherein the electrophotographic photoreceptor is any one or a mixture of a resin-based resin powder, a polyethylene-based resin powder, and a graft copolymer having a core-shell structure. 32. An electrophotographic photosensitive member according to claim 22, wherein the electrophotographic photosensitive member is charged, image-exposed, developed, and transferred by using the electrophotographic photosensitive member. An electrophotographic method characterized by using: 33. A writing light source having a wavelength of 4 in the image exposure.
33. The electrophotographic method according to claim 32, wherein the electrophotographic method is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range of 00 to 450 nm. 34. An electrophotographic apparatus equipped with at least an electrophotographic photosensitive member, a charging device, an image exposing unit, a developing unit, and a transfer unit, wherein the electrophotographic photosensitive member is any one of claims 22 to 31. An electrophotographic apparatus using an electrophotographic photosensitive member. 35. The electrophotographic apparatus according to claim 34, wherein a beam system of a writing light source in said image exposure is 10 to 30 μm. 36. The wavelength of the writing light source in the image exposure is 4
The electrophotographic apparatus according to claim 34 or 35, wherein the electrophotographic apparatus is a semiconductor laser or a light emitting diode having an oscillation wavelength in a range from 00 to 450 nm. 37. At least one unit selected from the group consisting of an electrophotographic photosensitive member, a charging device, an image exposing unit, a developing unit, a transferring unit, and a cleaning unit, and integrally supporting,
A process cartridge configured to be detachable from an electrophotographic apparatus main body, wherein the electrophotographic photosensitive member according to claim 22 is used as the electrophotographic photosensitive member.