JP2003084472A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high durability capable of sufficiently preventing the degradation in electric characteristics accompanying repetitive use and high resolution quality, a process cartridge having the same and an electrophotographic device. SOLUTION: The electrophotographic photoreceptor 100 has a conductive base layer 3, a photosensitive layer 6 containing pigments and an intermediate layer 4 arranged between the conductive base layer and the photosensitive layer, in which the intermediate layer includes zinc oxide particles and a binder resin; the zinc oxide particles included in the intermediate layer are <300 nm in the maximum value of the primary particle size and the average particle size thereof is 20 to 200 nm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor,
The present invention relates to a process cartridge and an electrophotographic apparatus.

[0002]

2. Description of the Related Art In recent years, electrophotographic photoreceptors have been widely used in the fields of copying machines, laser beam printers, etc., because they have the advantages of high speed and high printing quality. As the electrophotographic photosensitive member used in these electrophotographic apparatus, selenium, selenium-tellurium alloy, selenium-arsenic alloy, electrophotographic photosensitive member using an inorganic photoconductive material such as cadmium sulfide, etc., which are cheaper, more manufacturable and safe. An electrophotographic photoreceptor containing an organic photoconductive material such as a phthalocyanine-based pigment, which has excellent advantages, as a charge generating substance has come to be predominant.

Among them, the function-separated type photoreceptor having a photosensitive layer composed of a charge generating layer for generating a charge upon exposure and a charge transporting layer for transferring a charge is an electrophotographic characteristic such as sensitivity and chargeability and its repeated stability. Is excellent, and various proposals have been made and put to practical use.

In the case of this function-separated type photoreceptor, at present, an undercoat layer is formed on a conductive support layer such as an aluminum base material, and then a charge generation layer and a charge transport layer are sequentially formed on the undercoat layer. Often.

In particular, in recent years, a contact charging type charging device which generates less ozone has been used in place of the corotron in the electrophotographic apparatus, but the state of dispersion of the charge generating substance (pigment) in the photosensitive layer is changed. If the surface of the conductive support layer is uneven, there is unevenness or dirt,
If the thickness of the undercoat layer or photosensitive layer formed by coating on the conductive support layer is not uniform over the entire coated area due to coating unevenness or the like, or foreign matter is mixed in the photosensitive layer. When there is a local defect site on the photoconductor, a high electric field is locally applied to the defect site of the photoconductor at the time of contact charging, and an electrical pinhole is generated, which results in an image quality defect. There was a problem.

[0006] This pinhole leak is caused by conductive foreign matter or dust such as carbon fibers or carrier powder generated from members constituting the electrophotographic apparatus when the electrophotographic apparatus is in operation or contact with the photoconductor or penetrate into the photoconductor. It may also occur by doing.

In order to improve the repetitive stability and environmental stability of the photoconductor when used in an electrophotographic apparatus and prevent the occurrence of the above-mentioned image quality defect of the image, not only the performance of the photosensitive layer is improved but also the photosensitivity is improved. It is also necessary to improve the performance of the undercoat layer which is the base of the layer, and it is required to form an undercoat layer having less charge storage property by repeated use.

Therefore, in order to conceal the defects of the conductive support layer (base material) and improve the rise of the residual potential and obtain stable electric characteristics, the layer containing the conductive fine powder is made conductive. A method for forming a photoreceptor formed on a support layer has been studied.

As such a method, for example, a layer containing conductive fine powder is formed on a conductive support layer such as an aluminum base material, and further, a layer containing this conductive fine powder is formed. There has been proposed a method of forming a photoreceptor having a two-layered undercoat layer in which a layer having the same structure as a conventional undercoat layer is formed. In the case of this method, the layer containing the conductive fine powder is caused to conceal defects such as irregularities and stains on the surface of the conductive support layer and to adjust the electric resistance, and the conventional undercoat layer is used. A layer having a similar structure has a blocking (charge injection control) function.

As another method, only a layer containing conductive fine powder is formed as an undercoat layer on a conductive support layer, and this layer has both the blocking function and the resistance adjusting function described above. There is a method of forming a photoconductor having the constitution.

For example, in JP-A-10-177267, there is a large primary particle size (0.1 to 1.0) in the intermediate layer.
The metal oxide particles (inorganic pigment) having a large primary particle diameter (0.1 μm or less) are dispersed respectively, and the content of the metal oxide particles having a large primary particle diameter is 10 An electrophotographic photosensitive member has been proposed in which the content is at least mass%.

Further, in Japanese Patent Laid-Open No. 2000-231214, the content of metal oxide particles having a particle diameter of 0.2 μm or less is 1 among the metal oxide particles contained in the intermediate layer.
An electrophotographic photosensitive member having a content of 0% or more and a method for manufacturing the same have been proposed.

[0013]

However, the above-mentioned conventional electrophotographic photosensitive member is still insufficient in obtaining sufficient electric characteristics to withstand repeated use, and therefore, when the electrophotographic photosensitive member is repeatedly used. However, there is a problem that fogging such as black spots occurs on an image due to an increase in residual potential.

That is, since the electrophotographic photosensitive member having the above-mentioned two-layer structure undercoating layer is inferior in leak resistance, the above-mentioned pinhole leak is apt to occur, so that the charging property of the photosensitive member is deteriorated, and repeated use is caused. Therefore, there is a problem that the image density is lowered. Further, in this case, since the two-layer structure is used, it takes much labor and cost to manufacture the photoconductor.

In the electrophotographic photoreceptors described in JP-A-10-177267 and JP-A-2000-231214, the undercoat layer has a single-layer structure, so that the manufacturing process of the photoreceptor is simplified. However, it is necessary to combine the function of resistance control and the function of charge injection control, and there is a restriction in selecting the constituent material of the undercoat layer.

From the viewpoint of enhancing the leak resistance of the undercoat layer and preventing the occurrence of pinhole leak, it is effective to increase the layer thickness of the undercoat layer (hereinafter referred to as thickening). In order to obtain a thick film, it is necessary to reduce the electric resistance of the undercoat layer in order to obtain good electric characteristics.

However, when the electric resistance is reduced, the charge blocking function is deteriorated, and the occurrence of image defects such as fog tends to increase. Further, there are problems that it is difficult to form an undercoat layer having a large layer thickness, and the mechanical strength after formation is insufficient. Further, when the thickness of the undercoat layer is increased, there is a problem that the sensitivity of the photoreceptor is lowered.

Conventionally, metal oxide particles generally used for the undercoat layer include barium sulfate particles coated with titanium oxide or tin oxide.
The particle size is about 0.4 μm and the particle size is relatively large, and it is difficult to thicken the undercoat layer in which these are dispersed. Further, when titanium oxide is used as the other metal oxide particles in the form of ultrafine particles, it is difficult to obtain good dispersibility in the undercoat layer, and thus it is difficult to obtain particles having good electrical characteristics. It was Further, when tin oxide or antimony oxide-doped tin oxide particles or barium sulfate particles coated with tin oxide is used, the electric resistance of the obtained undercoat layer is low, and an intermediate layer having sufficient leak resistance is obtained. There was a problem that I could not.

The inventors of the present invention have described the above-mentioned Japanese Patent Laid-Open No. 10-177.
Even in the electrophotographic photoreceptors described in JP-A No. 267 and JP-A No. 2000-231214, if the layer thickness of the undercoat layer is increased, good electrical characteristics cannot be obtained and good image quality can be obtained. I found that it would disappear.

The present invention has been made in view of the above-mentioned problems of the prior art, and is an electrophotographic photosensitive member having high durability and high resolution quality capable of sufficiently preventing deterioration of electric characteristics due to repeated use. An object is to provide a body, a process cartridge including the same, and an electrophotographic apparatus.

[0021]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that
As a result of a study on the particle size of the metal oxide particles used in the undercoat layer in the conventional photoconductor and the particle size distribution in the undercoat layer, the characteristics of the photoconductor show that fogging or minute black spots For the occurrence of minute image quality defects in the image,
It was found that the presence of coarse particles contained in the metal oxide particles used in the intermediate layer has a great influence.

When the coarse particles of the metal oxide particles are present, the present inventors have found that the coarse particles serve as a singular point in electric conduction in the intermediate layer, and the electric resistance value of the region of the singular point is It was inferred that the electric resistance value was different from other regions in the intermediate layer.

Then, the present inventors have found that when the metal oxide particles contained in the intermediate layer arranged between the conductive support layer and the photosensitive layer are zinc oxide particles, the maximum value of the primary particle diameter is By not containing particles of 300 nm or more, the maximum value of the primary particle diameter of which is less than 300 nm, and by selectively containing particles having an average particle diameter of 20 to 200 nm, the intermediate layer is thickened. Also found that the increase in the electrical resistance of the undercoat layer can be easily reduced, and reached the present invention.

The present invention has a conductive support layer, a photosensitive layer containing a pigment, and an intermediate layer disposed between the conductive support layer and the photosensitive layer, and the intermediate layer comprises: Zinc oxide particles,
The zinc oxide particles containing a binder resin and contained in the intermediate layer have a maximum primary particle diameter of less than 300 nm, and an average particle diameter of 20 to 200 nm. A photographic photoreceptor is provided.

Even if the intermediate layer is thickened, the electrical resistance of the intermediate layer can be increased by selectively dispersing in the intermediate layer only zinc oxide particles that simultaneously satisfy the conditions of the primary particle diameter and the average particle diameter described above. Can be easily reduced. Therefore, even if the thickness of the intermediate layer is increased, good electrical characteristics of the photoconductor can be obtained, and further, the leak resistance of the undercoat layer can be improved and the occurrence of pinhole leak can be effectively prevented.

Therefore, the electrophotographic photosensitive member of the present invention has high durability and can sufficiently prevent the deterioration of electric characteristics even after repeated use over a long period of time, so that a good image quality is stabilized. Can be obtained.

Here, in the present invention, the reason why the above effects can be obtained by using small zinc oxide particles satisfying the above-mentioned particle size conditions is that the present inventors have the above-mentioned particle size conditions. Small zinc oxide particles that meet
By including in the intermediate layer, a charge conduction path composed of a large number of zinc oxide particles having good electrical conductivity is formed, and a short-circuit current flow in the intermediate layer is suppressed, resulting in a leakage defect due to abnormal discharge. We believe that the occurrence of

Here, when the primary particle diameter of the zinc oxide particles contained in the intermediate layer is 300 nm or more, or when the average particle diameter of the zinc oxide particles exceeds 200 nm,
Since the charge conduction path in the intermediate layer is formed by a small number of zinc oxide particles, local unevenness in the potential of the photoconductor may occur, and nonuniformity such as image fogging may be likely to occur. The average particle diameter of the zinc oxide particles is 20 nm.
When it is less than the above range, the dispersibility in the coating liquid for forming the intermediate layer is deteriorated, and it becomes difficult to form a coating liquid that is good for forming a coating film (intermediate layer).

From the same viewpoint as above, the maximum value of the primary particle diameter of the zinc oxide particles contained in the intermediate layer is 200 n.
More preferably, it is less than m. In addition, the zinc oxide particles contained in the intermediate layer preferably have an average particle diameter of 30 to 100 nm.

In the present invention, the "average particle diameter of zinc oxide particles" is a value determined based on the specific surface area of zinc oxide particles measured by the BET method. The BET method is a method in which a gas such as nitrogen is adsorbed on the zinc oxide particles and the specific surface area (BET specific surface area) of the zinc oxide particles is obtained from the reduced amount of the adsorbed gas. Note that the average particle size in this case indicates a value when the zinc oxide particles are approximated to a spherical shape, so that a zinc oxide particle closer to a spherical shape is closer to the average particle size obtained using a scanning electron microscope or a transmission electron microscope. The value is obtained.

B of zinc oxide particles measured by BET method
When the ET specific surface area is Sm ² / g and the specific gravity of the zinc oxide particles is ρ (= 5.6), the average particle diameter of the zinc oxide particles is
The (BET diameter) [μm] can be calculated as the average particle diameter = 6 / (S · ρ).

In the present invention, the method for selectively obtaining only the zinc oxide particles satisfying the above-mentioned particle size from the powder of zinc oxide particles is not particularly limited. A method of changing the temperature control condition for crystal growth, a method of classifying the obtained zinc oxide particles based on size using a sieve or a centrifuge, and the like can be used.

In the powder of zinc oxide particles, coarse particles that do not satisfy the above-mentioned particle size conditions cannot be observed by the BET method, so that they cannot be observed by an optical microscope such as a scanning electron microscope or a transmission electron microscope. It is possible to directly observe the zinc oxide particle powder by using the method and confirm it.If coarse particles are present, it is possible to add a treatment such as milling by milling to make the coarse particles into fine particles. Is.

Further, in the case of the electrophotographic photosensitive member of the present invention, the thickness of the intermediate layer can be easily increased, so that the layer thickness of the intermediate layer may be 15 to 50 μm, and more than 20 μm. It may be 50 μm or less. By setting the thickness of the intermediate layer to 15 μm or more, and further to 20 μm or more, it is possible to enhance the leak resistance of the undercoat layer and more reliably prevent the occurrence of pinhole leak.

Here, when an intermediate layer having a layer thickness of more than 50 μm is formed on a conductive substrate, it tends to be difficult to maintain good dispersibility of a contained substance such as metal oxide particles. It also becomes difficult to make the layer thickness uniform and the manufacturing cost increases.

In the present invention, the binder resin contained in the intermediate layer is at least one selected from the group consisting of urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin and polyurethane resin. Or a thermosetting resin of
A resin obtained by reacting at least one resin selected from the group consisting of polyamide resin, polyester resin, polyether resin, acrylic resin, polyvinyl alcohol resin, and polyvinyl acetal resin with a curing agent is preferable.

By including the above resin as a binder resin in the intermediate layer, the mechanical strength of the intermediate layer can be made higher than that of the conventional undercoating layer described above, and it is easier to form a thick film. You can Further, since such a binder resin has a low hygroscopicity, the intermediate layer containing the binder resin can sufficiently suppress the fluctuation in conductivity due to the fluctuations in temperature and humidity in the use environment.

Further, since such a binder resin has high mechanical strength and low flexibility, even if foreign matter adheres to the photosensitive layer during use of the electrophotographic photoreceptor, it penetrates through the intermediate layer to provide a conductive support. It is possible to effectively prevent mixing into the body layer.

Further, the present invention integrally includes any one of the electrophotographic photosensitive members described above and at least one unit of a charging unit, a developing unit, a cleaning unit and a charge eliminating unit, and is detachably attached to the main body of the electrophotographic apparatus. A process cartridge is provided.

As a result, the process cartridge of the present invention can obtain high resolution quality without causing fog such as black spots on the image when repeatedly used.

Further, the present invention is any one of the electrophotographic photoconductors described above, a charging unit for charging the electrophotographic photoconductor, an exposing unit for exposing the electrophotographic photoconductor charged by the charging unit, and an exposing unit. Provided is an electrophotographic apparatus, comprising: a developing unit that develops a portion exposed by the developing unit; and a transfer unit that transfers the image developed by the developing unit to the electrophotographic photosensitive member.

As a result, the electrophotographic apparatus of the present invention can maintain high resolution quality for a long period of time without causing fog such as black spots on a copy image when repeatedly used.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus of the present invention will be described in detail below with reference to the drawings. In addition,
In the drawings, the same or corresponding parts are designated by the same reference numerals.

[First Embodiment] FIG. 1A is a sectional view showing a first embodiment of the electrophotographic photosensitive member of the present invention. As shown in FIG. 1A, the electrophotographic photosensitive member 100 includes a conductive support layer 3, an intermediate layer 4, and a photosensitive layer 6.

The conductive support layer 3 is not particularly limited and, for example, a metal drum of aluminum, copper, iron, zinc, nickel or the like can be used. In addition, on a polymer sheet, paper, plastic, or glass, aluminum, copper, gold, silver, platinum, palladium, titanium
A drum-shaped, sheet-shaped, or plate-shaped material obtained by conducting a metal by vapor-depositing a metal such as nickel-chrome, stainless steel, or copper-indium can be used.

Further, a drum-shaped sheet which is conductively processed by vapor-depositing a conductive metal compound such as indium oxide / tin oxide or laminating a metal foil on a polymer sheet, paper, plastic or glass. Condition
Plate-shaped objects can be used. In addition to this,
Drum-shaped or sheet that is conductively treated by dispersing carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. in a binder resin and applying it on a polymer sheet, paper, plastic, or glass Shaped or plate-shaped objects can also be used.

Here, when the metal pipe base material is used as the conductive support layer 3, even if the surface of the metal pipe base material remains the raw pipe, mirror cutting, etching, anodic oxidation, rough cutting,
It is preferable to perform processing such as centerless grinding, sandblasting, wet honing, and coloring treatment. By performing the surface treatment to roughen the surface of the base material, it is possible to prevent wood grain-like density unevenness due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used.

The intermediate layer 4 contains the above-mentioned metal oxide particles satisfying the particle diameter condition and the binder resin. Then, the intermediate layer 4 is
It has a function of preventing injection of charges from the conductive support layer 3 to the photosensitive layer 6. Further, the intermediate layer 4 also functions as an adhesive layer that integrally adheres and holds the photosensitive layer 6 to the conductive support layer 3. Further, the intermediate layer 4 has a function of preventing light reflection of the conductive support layer 3.

Then, as described above, the binder resin is at least one heat selected from the group consisting of urea resin, melamine resin, phenol resin, epoxy resin, unsaturated polyester resin, alkyd resin and polyurethane resin. A curable resin or a resin obtained by reacting at least one resin selected from the group consisting of polyamide resin, polyester resin, polyether resin, acrylic resin, polyvinyl alcohol resin and polyvinyl acetal resin with a curing agent is preferable. Used.

In the case of the intermediate layer 4, the layer thickness may be 15 μm or more, or may be greater than 20 μm. However, as described above, the layer thickness of the intermediate layer 4 is preferably 50 μm or less.

The above-mentioned curing agent is preferably isocyanate. As the isocyanate, of the isocyanates obtained by reacting a polyisocyanate compound with a compound having active hydrogen as a blocking agent, the isocyanate is stable at room temperature and blocks when heated under predetermined conditions (for example, 50 to 200 ° C.). Isocyanates in which the agent dissociates to regenerate the isocyanate groups are preferred.

Examples of the above polyisocyanate compounds include tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, polymethylene polyfell polyisocyanate and the like.

Examples of the blocking agent include lactams such as caprolactom, oximes such as methylethylketoxime and acetoxime, diethyl malonate,
Examples include β-diketones such as diethyl acetoacetate.

The electric resistance value of the intermediate layer 4 is 10 ⁴ to 10 ¹³ Ω.
cm, preferably 10 ⁸ to 10 ¹³ Ωcm, more preferably 10 ⁹ to 10 ¹² Ωcm. If the resistance value is less than 10 ⁴ Ωcm, it tends to be difficult to obtain sufficient leak resistance, and 1
If it exceeds 0 ¹³ Ωcm, there is a large tendency to cause an increase in residual potential. The electric resistance value of the intermediate layer 4 can be controlled by changing the electric resistance value of the metal oxide particles themselves and the addition amount thereof, and by changing the dispersion state of the metal oxide particles in the binder resin.

As the zinc oxide particles contained in the intermediate layer 4, those satisfying the above-mentioned particle size conditions are used. As the zinc oxide particles, those produced by various conventionally known chemical or physical processes can be used. For example, those produced by the indirect method (French method) or the direct method (American method) described in JIS K1410 may be used.

The indirect method (French method) heats metallic zinc to 1000 ° C. and oxidizes zinc vapor with hot air. The zinc oxide particles produced are cooled in an air blower through an air cooler and sorted according to the size of the particles. In addition, the direct method (American method) reduces zinc oxide particles obtained by burning zinc ore with coal etc. and oxidizes the generated zinc vapor with hot air, or leaches the zinc ore with sulfuric acid. Zinc is melted in an electric furnace by adding coke, etc. to the mine, and is oxidized by hot air. Then, this is processed similarly to the indirect method.

In addition, zinc oxide particles obtained by roasting zinc carbonate obtained by reacting zinc chloride with sodium carbonate may be used. Alternatively, zinc oxide particles obtained by a wet manufacturing method in which basic zinc carbonate produced by precipitating a hydrochloric acid solution of zinc with an alkaline solution is burned may be used.

Further, in a reduced pressure atmosphere, a heating means such as plasma is applied to metallic zinc to evaporate the metallic zinc, and a cooling gas containing oxygen is applied to the generated ultrafine particles to oxidize them and to stop crystal growth. You may use the zinc oxide particle obtained by the method.

The zinc oxide particles have a powder resistance value of 10
Those having a powder resistance of 10 ⁴ to 10 ¹⁰ Ω · cm are particularly preferable from the viewpoint of obtaining excellent leak resistance of the intermediate layer 4, although those having a resistivity of ² to 10 ¹¹ Ω · cm can be used. 10 ²
If it is less than Ωcm, sufficient leak resistance cannot be obtained, and 10
^If it exceeds ¹¹ Ωcm, the residual potential tends to rise.

From the viewpoint of suppressing fluctuations in the electric resistance value of the intermediate layer 4 due to fluctuations in temperature and humidity in the use environment, it is preferable that the zinc oxide particles are surface-treated with a coupling agent. This makes it possible to easily control the dispersed state of the zinc oxide particles, which greatly affects the electric resistance of the intermediate layer 4, to a state suitable for obtaining the above-mentioned preferable electric resistance value.

Here, the surface treatment means a treatment in which the coupling agent is adsorbed on the surface of the zinc oxide particles and the alkoxy group of the coupling agent is hydrolyzed there.

The coupling agent is preferably at least one selected from the group consisting of a silane coupling agent, a titanate coupling agent and an aluminate coupling agent.

As the silane coupling agent, for example,
Vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-
Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-
β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-
Examples thereof include aminopropyltriethoxysilane and γ-chloropropyltrimethoxysilane.

Examples of titanate coupling agents include isopropyltriisostearoyl titanate,
Examples thereof include bis (dioctyl pyrophosphate) and isopropyl tri (N-aminoethyl-aminoethyl) titanate.

As the aluminate coupling agent,
Examples thereof include acetoalkoxyaluinium diisopropylate and the like. However, it is not limited thereto. In addition, you may use these coupling agents in mixture of 2 or more types.

The amount of the coupling agent used is preferably 0.1 to 10% by mass of the zinc oxide particles. If the amount of the coupling agent used is less than 0.1% by mass of the zinc oxide particles, the image quality defect tends to occur. Further, if the amount of the coupling agent used exceeds 10% by mass of the zinc oxide particles, the electrical characteristics of the photoconductor 100 may deteriorate and the sensitivity may decrease.

The method of treating the surface of the zinc oxide particles with the coupling agent is not particularly limited, and known methods such as a dry method, a wet method and a vapor phase method may be used.

For example, an example of a procedure for performing the surface treatment based on the dry method will be described. First, before surface treatment, zinc oxide particles are pre-dried at a temperature of 100 to 150 ° C. to remove surface-adsorbed water. By removing this surface-adsorbed water before the treatment, the coupling agent can be uniformly adsorbed on the surface of the zinc oxide particles. At this time, the zinc oxide particles may be pre-dried while being stirred by a mixer having a large shearing force.

Next, the coupling agent is adsorbed on the surface of the zinc oxide particles. At this time, while stirring the zinc oxide particles with a mixer having a large shearing force, the coupling agent is sprayed together with dry air or nitrogen gas, or the coupling agent is dissolved in a solvent (organic solvent, water, etc.). Is sprayed with dry air or nitrogen gas. As a result, the coupling agent is uniformly adsorbed on the surface of the zinc oxide particles.

The temperature at which the coupling agent is adsorbed on the surface of the zinc oxide particles is preferably 50 ° C. or higher. When a solvent is used, it is preferably carried out at a temperature near the boiling point of the solvent.

Then, a baking process is performed at a temperature of 100 ° C. or higher. This allows the hydrolysis reaction of the coupling agent to proceed sufficiently. The baking treatment is preferably performed at a temperature of 150 to 250 ° C. 1
If it is lower than 50 ° C, the hydrolysis reaction of the coupling agent may not be able to proceed sufficiently. If it exceeds 250 ° C, the coupling agent may be decomposed.

Next, if necessary, the surface-treated zinc oxide particles are pulverized. As a result, the aggregate of zinc oxide particles can be crushed, so that the dispersibility of the zinc oxide particles in the mid layer 4 can be improved.

The intermediate layer 4 may contain other additives in order to improve its electric characteristics, shape stability in use environment, and image quality.

For example, chloranil, bromoanil, quinone compounds such as anthraquinone, tetracyanoquinodimethane compound, 2,4,7-trinitrofluorenone, 2,4,5,
Fluorenone compounds such as 7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-
Oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,
Oxadiazole compounds such as 3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ', 5,
Electron-transporting substances such as diphenoquinone compounds such as 5'tetra-t-butyldiphenoquinone, polycyclic condensation systems, electron-transporting pigments such as azo systems, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds A known material such as an organic titanium compound may be contained.

As the titanium chelate compound, for example, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2
-Ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt,
Titanium lactate, titanium lactate ethyl ester,
Examples thereof include titanium triethanolaminate and polyhydroxytitanium stearate.

Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate) and the like. These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds.

Further, from the viewpoint of preventing the foreign matter such as the conductive powder from the outside from penetrating the photoreceptor, which is one of the causes of the current leakage at the time of contact charging, and forming the intermediate layer 4 having high durability, It is effective to increase the hardness of the layer 4, and it is preferable that the Vickers hardness of the intermediate layer 4 is 30 or more, preferably 35 or more as an index of the hardness.

From the viewpoint of preventing interference fringes, the surface roughness of the intermediate layer 4 is adjusted to 1 / 4n (n is the refractive index of the upper layer) to λ when the exposure laser wavelength λ is used. Preferably. The surface referred to here is the surface of the intermediate layer 4 on the side facing the photoreceptor layer. Further, resin particles may be added to the mid layer 4 for adjusting the surface roughness. As the resin particles, silicone resin particles, crosslinked polymethylmethacrylate resin (PMMA) particles and the like can be used.

Further, the surface of the intermediate layer 4 may be polished to adjust the surface roughness. As the polishing method, buffing, sandblasting, wet honing, grinding or the like can be used.

The intermediate layer 4 is obtained by surface-treating the above-mentioned zinc oxide particles with a coupling agent and then dispersing the dispersion liquid in a binder resin to apply the coating liquid onto the conductive support layer 3. Can be formed.

As a solvent for preparing the coating liquid for forming the intermediate layer 4, a known organic solvent such as an alcohol-based solvent,
It can be arbitrarily selected from aromatic series, halogenated hydrocarbon series, ketone series, ketone alcohol series, ether series, ester series and the like.

For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane. , Tetrahydrofuran, methylene chloride, chloroform,
Usual organic solvents such as chlorobenzene and toluene can be used.

The solvents used for dispersion may be used alone or in admixture of two or more. When mixing, any solvent can be used as long as it can dissolve the binder resin as a mixed solvent.

The method of dispersing the metal oxide surface-treated with the coupling agent in the binder resin is as follows:
A method such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill or a paint shaker can be used. Further, as a coating method used when providing the undercoat layer, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be used. Can be used.

Next, the photosensitive layer 6 will be described. Figure 1
As shown in (a), the photosensitive layer 6 is composed of a charge generation layer 1 and a charge transport layer 2.

The pigment (charge generating substance) contained in the charge generating layer 1 is not particularly limited, and known pigments can be used.

In the photoreceptor utilizing infrared light, for example, phthalocyanine pigment, squarylium pigment, bisazo pigment, trisazo pigment, perylene pigment, dithioketopyrrolopyrrole pigment can be used. Further, in the photoreceptor using the visible light laser, for example, a condensed polycyclic pigment, a bisazo pigment, a perylene pigment, trigonal selenium, a dye-sensitized metal oxide, or the like can be used.

Among the above-mentioned pigments, it is preferable to use a phthalocyanine type pigment because an excellent image can be obtained. Accordingly, it is possible to easily form an electrophotographic photosensitive member having a particularly high sensitivity and capable of stably obtaining a good image quality even when repeatedly used.

The phthalocyanine pigment generally has several crystal forms, and any crystal form can be used as long as it is a crystal form capable of obtaining a sensitivity suitable for the purpose. In particular, among the phthalocyanine pigments, the following formula (1)
Phthalocyanine pigments represented by (6) to (6) are preferably used.

[Chemical 1]

In the above formulas (1) to (6), chlorogallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) of 7. in the X-ray diffraction spectrum using Cuk α ray.
Those having at least diffraction peaks at positions of 4 °, 16.6 °, 25.5 °, and 28.3 ° are preferable. Further, as titanyl phthalocyanine, in the X-ray diffraction spectrum using Cuk α-ray, the value of Bragg angle (2θ ± 0.2 °) is 9.6 °, 24.1
At least a diffraction peak at a position of 27.3 °,
Those having a maximum peak at 27.3 ° are preferred.

In addition to the phthalocyanine pigments represented by the following formulas (1) to (6), G which is the coordination center of the formula (4)
A hydroxygallium phthalocyanine in which a Cl atom bonded to a is substituted with an -OH group is also preferable. As such hydroxygallium phthalocyanine, in the X-ray diffraction spectrum using Cuk α-ray, the Bragg angle (2θ
± 0.2 °) value is 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 2
Those having at least diffraction peaks at positions of 5.1 ° and 28.1 ° are preferable.

Further, as such a pigment, a pigment crystal produced by a known method is added to an automatic mortar, planetary mill, vibration mill,
It can be produced by mechanically dry pulverizing with a CF mill, roller mill, sand mill, kneader or the like, or by performing wet pulverization treatment with a solvent using a ball mill, mortar, sand mill, kneader or the like after dry pulverizing.

As the solvent used in the above wet pulverization treatment, aromatics (toluene, chlorobenzene, etc.),
Amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyhydric alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol) , Phenethyl alcohol etc.), esters (acetic acid ester, butyl acetate etc.), ketones (acetone, methyl ethyl ketone etc.), dimethyl sulfoxide, ethers (diethyl ether,
Tetrahydrofuran etc.), a mixed system of several kinds, and a mixed system of water and these organic solvents.

Further, this solvent was added to the pigment crystals in an amount of 1
To 200 parts by mass, preferably 10 to 100 parts by mass. Further, the treatment temperature is 0 ° C to the boiling point of the solvent, preferably 10 to 60 ° C. Further, at the time of crushing, it is possible to use a grinding aid such as sodium chloride and sodium sulfate.

The grinding aid is 0.5 to 20 times the amount of the pigment,
It is preferable to use 1 to 10 times. Further, the pigment crystals produced by a known method can be controlled by combining acid pasting or acid pasting with dry pulverization or wet pulverization as described above.

As the acid used for acid pasting, sulfuric acid is preferable, and the concentration (mass percent concentration) is 70 to
100%, preferably 95-100%, is used, and the melting temperature is set in the range of -20 to 100 ° C, preferably 0 to 60 ° C. The amount of concentrated sulfuric acid is 1 to 100 based on the weight of pigment crystals.
Double, preferably 3 to 50 times. As a solvent for precipitation, water, a mixed solvent of water and an organic solvent, aqueous ammonia, or the like is used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation.

The content of the pigment is preferably 10 to 90% by mass, more preferably 40 to 70% by mass, based on the total mass of the charge generation layer 1. When the content of each pigment is less than the lower limit value of the above numerical range, it becomes difficult to obtain sufficient sensitivity. On the other hand, when the content of the pigment exceeds the upper limit of each of the above numerical ranges, there is a large tendency that adverse effects such as a decrease in charging property and a decrease in sensitivity occur.

The binder resin contained in the charge generation layer 1 is not particularly limited as long as it is an insulating resin.
A wide range of insulating resins can be selected and used.
For example, as a preferable binder resin, polyvinyl acetal resin, polyarylate resin (bisphenol A
Polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin Examples thereof include insulating resins such as casein, polyvinyl alcohol resin, and polyvinylpyrrolidone resin.

From the viewpoint of the dispersibility of the pigment, a polyvinyl acetal resin and a vinyl chloride-vinyl acetate copolymer are preferably used as the binder resin for the charge generation layer 1. The above binder resins may be used alone or in combination of two or more.

Also, the compounding ratio of the pigment and the binder resin
In the case of the charge generation layer 1, the (mass ratio) is preferably in the range of 10: 1 to 1:10. When the mass of the binder resin is less than the value shown by the above blending ratio with respect to the mass of the pigment, there is a large tendency that adverse effects such as poor film forming properties occur. On the other hand, if the mass of the binder resin exceeds the value shown by the above blending ratio with respect to the mass of the pigment, the content in the film becomes relatively small, so that sufficient sensitivity cannot be obtained.

Further, the organic solvent contained in the coating liquid for forming the charge generating layer 1 is a solvent capable of dissolving the binder resin, and has an effect of changing the crystal type of the pigment (charge generating substance). It is not particularly limited as long as it does not affect, and a known organic solvent can be used.

For example, it can be arbitrarily selected from alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters and the like. Specifically, for example, methanol, ethanol, n-
Propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, A usual organic solvent such as toluene can be used. These organic solvents can be used alone or in combination of two or more.

To the charge generation layer 1, other additives similar to those described in the description of the intermediate layer 4 may be added in order to improve its electric characteristics and image quality.

Further, the layer thickness of the charge generation layer 1 is preferably 0.05 to 5 μm, and more preferably 0.1 to 1 μm in order to provide good electric characteristics and image quality. When the thickness of the charge generation layer 1 is less than 0.05 μm,
It cannot give sufficient sensitivity. On the other hand, when the thickness of the charge generation layer 1 exceeds 5 μm, it is easy to cause problems such as poor chargeability.

The charge generation layer 1 comprises a pigment (charge generation substance),
It can be formed by mixing an organic solvent, a binder resin, an additive (for example, a dispersion aid of a pigment, etc.) and the like to prepare a coating liquid, coating this on the intermediate layer 4 and further drying. The charge generation layer 1 can also be formed by vacuum depositing a charge generation substance on the intermediate layer 4.

To prepare the coating liquid for forming the charge generation layer 1, it is mixed with a pigment, a binder resin, an organic solvent, other additives (for example, a pigment dispersion aid, etc.) and the like.
As a method for highly dispersing the pigment in the liquid, a roll mill,
A dispersion method such as a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill or a paint shaker can be used.

From the viewpoint of film-forming property, the particle size of dispersed particles such as pigment contained in the coating liquid for forming the charge generation layer 1 is preferably 0.5 μm or less, and 0.3 μm or less. It is more preferable that the thickness is 0.15 μm or less. If the particle size of the dispersed particles exceeds 0.5 μm, the film-forming property of the charge generation layer 1 deteriorates, and image quality defects are likely to occur.

The coating liquid for forming the charge generation layer 1 was applied to the intermediate layer 4
As a coating method for coating on the surface, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method or a curtain coating method can be used. .

Next, the charge transport layer 2 will be described. The charge transport material contained in the charge transport layer 2 is not particularly limited, and known materials can be used.

For example, oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl-
(2)]-3- (p-Diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline and other pyrazoline derivatives, triphenylamine, tri (P-methyl) phenylamine, N,
Aromatic tertiary such as N'-bis (3,4-dimethylphenyl) biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N'-di (p-tolyl) fluorenone-2-amine Tertiary amino compounds, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-diamine and other aromatic tertiary diamino compounds, 3- (4 'dimethylaminophenyl) -5,6-
1,2-, such as di- (4'-methoxyphenyl) -1,2,4-triazine
4-triazine derivatives, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenylaminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone and other hydrazone derivatives, Quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2,3-di (p-
Benzofuran derivatives such as (methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N'-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N -Hole transporting substances such as vinylcarbazole and its derivatives, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7- Fluorenone compounds such as tetranitro-9-fluorenone, 2- (4-biphenyl) -5
-(4-t-Butylphenyl) -1,3,4-oxadiazole, 2,5-
Bis (4-naphthyl) -1,3,4-oxadiazole, 2,5-bis
(4-Diethylaminophenyl) oxadiazole compounds such as 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, and diphenoquinone compounds such as 3,3 ′, 5,5 ′ tetra-t-butyldiphenoquinone Electron transport materials such as

Further, examples of the charge transport material include polymers having the basic structure of the above-exemplified compounds in the main chain or side chain. These charge transport materials can be used alone or in combination of two or more.

The binder resin contained in the charge transport layer 2 is not particularly limited, and known ones can be used, but a resin capable of forming an electrically insulating film is preferable. .

For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, chloride Vinyl-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin. Silicon-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinylidene chloride. Examples include polymer waxes and polyurethanes.

These binder resins can be used alone or in admixture of two or more. In particular, a polycarbonate resin, a polyester resin, a methacrylic resin, and an acrylic resin are preferably used because they are excellent in compatibility with the charge transport material, solubility in a solvent, and strength.

Further, the compounding ratio (mass ratio) of the binder resin and the charge transporting substance can be arbitrarily set in consideration of deterioration of electric characteristics and deterioration of film strength. The layer thickness of the charge transport layer 2 is preferably 5 to 50 μm, more preferably 10 to 35 μm. Is appropriate.

The charge-transporting layer 2 can be formed by mixing a charge-transporting substance, an organic solvent, a binder resin and the like to prepare a coating solution, coating the coating solution on the charge-generating layer 1 and further drying. .

To prepare a coating solution for forming the charge transport layer 2, it is mixed with a charge transport material, an organic solvent, a binder resin and the like. As a method for highly dispersing the charge transport substance in a liquid, a roll mill, a ball mill, a vibrating ball mill,
A dispersion method such as an attritor, a sand mill, a colloid mill or a paint shaker can be used.

From the viewpoint of film-forming property, the particle size of dispersed particles such as pigment contained in the coating liquid for forming the charge transport layer 2 is preferably 0.5 μm or less, and 0.3 μm or less. It is more preferable that the thickness is 0.15 μm or less. When the particle size of the dispersed particles exceeds 0.5 μm, the film forming property of the charge transport layer 2 is deteriorated, and image quality defects are likely to occur.

Further, as the solvent used for the coating liquid for forming the charge transport layer 2, dioxane, tetrahydrofuran,
Methylene chloride, chloroform, chlorobenzene,
Ordinary organic solvents such as toluene may be used alone or in combination of two or more.

As a method for applying the charge transport layer 2, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method may be used. You can

[Second Embodiment] FIG. 1B is a sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 110 shown in FIG. 1B has the same configuration as the electrophotographic photosensitive member 100 shown in FIG. 1A except that the photosensitive layer 6 has a single-layer structure.

The photosensitive layer 6 shown in FIG. 1B is the same as that shown in FIG.
The charge generating layer 1 and the charge transporting layer 2 shown in 1 above are layers containing both the charge generating substance and the substance including the charge transporting substance.

When the photosensitive layer 6 is a single layer type as described above,
The content of the pigment is 0.1 to the total mass of the photosensitive layer 6.
It is preferably 50% by mass, more preferably 1 to 20% by mass. Further, if the content of the pigment is less than the lower limit of the above numerical range, it becomes difficult to obtain sufficient sensitivity. On the other hand, when the content of the pigment exceeds the upper limit of the above numerical range, there is a large tendency that adverse effects such as a decrease in charging property and a decrease in sensitivity occur.

When the photosensitive layer 6 is of a single layer type as described above, a polycarbonate resin and a methacrylic resin are particularly preferably used as the binder resin from the viewpoint of compatibility with the hole transporting material. Furthermore, poly-N-vinylcarbazole, polyvinylanthracene, and
You may select and use it from organic photoconductive polymers, such as polyvinylpyrene and polysilane. The above binder resins may be used alone or in combination of two or more.

This photosensitive layer 6 also includes the above-mentioned charge transport material,
It may be formed by mixing the above-mentioned charge-transporting substance, the above-mentioned organic solvent, the binder resin and the like to prepare a coating solution, coating the same on the conductive support layer 3 by the same method as described above, and further drying. it can.

[Third Embodiment] FIG. 2A is a sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 120 shown in FIG. 2A has the same configuration as the electrophotographic photoreceptor 100 shown in FIG. 1A except that the protective layer 5 is provided on the photosensitive layer 6.

The protective layer 5 prevents a chemical change in the charge transport layer 2 when the electrophotographic photosensitive member 120 is charged, and prevents the photosensitive layer 6 from being changed.
Used to further improve the mechanical strength of. The protective layer 5 is formed by coating the photosensitive layer 6 with a coating liquid containing a conductive material in a suitable binder resin. This conductive material is not particularly limited,
For example, N, N'-dimethylferrocene and other metallocene compounds, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-
Aromatic amine compounds such as [1,1'-biphenyl] -4,4'-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, barium sulfate and antimony oxide Solid solution carrier, a mixture of the above metal oxides, a mixture of the above metal oxides in a single particle of titanium oxide, tin oxide, zinc oxide or barium sulfate, or titanium oxide, tin oxide, zinc oxide Alternatively, a single particle of barium sulfate coated with the above metal oxide may be used.

As the binder resin used for the protective layer 5, polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin,
Known resins such as polyimide resin and polyamide-imide resin are used. In addition, these can be used by being cross-linked with each other as necessary.

The thickness of the protective layer 5 is preferably 1 to 20 μm, more preferably 2 to 10 μm.
As a coating method of the coating liquid for forming the protective layer 5, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method,
Bead coating method, air knife coating method,
A usual method such as a curtain coating method can be used.

As the solvent used in the coating liquid for forming the protective layer 5, a common organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene is used alone or in combination of two or more. However, it is preferable to use a solvent that hardly dissolves the photosensitive layer 6 to which the coating liquid is applied, as much as possible.

[Fourth Embodiment] FIG. 2B is a sectional view showing a second embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 130 shown in FIG. 2B has the same structure as that shown in FIG. 1 except that the photosensitive layer 6 has a single-layer structure and the protective layer 5 is provided on the photosensitive layer 6.
It has the same structure as the electrophotographic photosensitive member 100 shown in FIG. Then, the photosensitive layer 6 shown in FIG.
It has the same structure as the photosensitive layer 6 shown in (b).

[Fifth Embodiment] FIG. 3A is a sectional view showing a fifth embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member 140 shown in FIG. 3A has the same configuration as the electrophotographic photosensitive member 100 shown in FIG. 1A except that an undercoat layer 42 is provided between the photosensitive layer 6 and the intermediate layer 4. Have. The undercoat layer 42 is provided to improve the electrical characteristics of the photoconductor 140, the image quality, and the adhesiveness of the photosensitive layer 6.

The constituent material of the undercoat layer 42 is not particularly limited, and can be arbitrarily selected from synthetic resin, powder of organic substance or inorganic substance, electron transporting substance and the like.

Examples of synthetic resins include acetal resins such as polyvinyl butyral, polyvinyl alcohol resins, casein, polyamide resins, cellulose resins, gelatin,
Polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin,
Polymer resin compounds such as phenol-formaldehyde resin and melamine resin, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds,
Known materials such as titanium alkoxide compounds, organic titanium compounds, and silane coupling agents can be used.

These compounds can be used alone or as a mixture or polycondensation product of a plurality of compounds. Further, among these, the zirconium chelate compound and the silane coupling agent are excellent in performance such as low residual potential, little potential change due to environment, and little potential change due to repeated use.

Examples of the above silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-
Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-
β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-
Examples thereof include aminopropyltriethoxysilane and γ-chloropropyltrimethoxysilane.

Among these, particularly preferably used silicon compounds are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3
-Aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane A silane coupling agent such as 3-chloropropyltrimethoxysilane can be used.

Examples of the zirconium chelate compound include zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate. , Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate,
Methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like can be mentioned.

As the titanium chelate compound, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate,
Examples thereof include polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanolaminate, and polyhydroxytitanium stearate.

Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate) and the like.

Fine powders of various organic compounds or fine powders of inorganic compounds can be added to the undercoat layer 42 for the purpose of improving electrical characteristics and light scattering. In particular, titanium oxide, zinc oxide, zinc white, zinc sulfide,
White pigments such as lead white and lithopone, inorganic pigments as extender pigments such as alumina, calcium carbonate, barium sulfate, Teflon (registered trademark) resin particles, benzoguanamine resin particles, and styrene resin particles are effective.

The particle size of the added fine powder is 0.01 to 2 μm. The fine powder is added as necessary, and the addition amount is a mass ratio with respect to the total mass of the solid content of the undercoat layer 42.
The amount is preferably 10 to 90% by mass, more preferably 30 to 80% by mass.

Further, it is also effective from the viewpoint of lowering the residual potential and environmental stability that the undercoat layer 42 contains the above-mentioned electron-transporting substance, electron-transporting pigment and the like. Furthermore,
The thickness of the undercoat layer 42 is 0.01 to 30 μm, preferably 0.05 to 25
μm is preferred.

When a coating liquid for forming the undercoat layer 42 is prepared, when a fine powder substance is added, it is added to a solution in which a resin component is dissolved for dispersion treatment. As the dispersion treatment method, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, or the like can be used.

Further, the undercoat layer 42 is the conductive support layer 3
It can be formed by applying a coating liquid for forming the undercoat layer 42 thereon and drying it. As a coating method at this time, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method can be used.

[Sixth Embodiment] FIG. 3B is a sectional view showing a sixth embodiment of the electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor 150 shown in FIG. 3B is shown in FIG. 1A except that the photosensitive layer 6 has a single-layer structure and the undercoat layer 42 is provided between the photosensitive layer 6 and the intermediate layer 4. Electrophotographic photoreceptor 100
It has the same configuration as.

Then, the undercoat layer 42 is formed as shown in FIG.
It has the same structure as the photoconductor 150 shown in FIG.

[Seventh Embodiment] FIG. 4A is a sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.

The electrophotographic photosensitive member 160 shown in FIG.
Provides the protective layer 5 on the photosensitive layer 6, and the photosensitive layer 6 and the intermediate layer 4
The electrophotographic photosensitive member 100 has the same structure as that of the electrophotographic photosensitive member 100 shown in FIG.

Then, the undercoat layer 42 is formed as shown in FIG.
The undercoat layer 42 of the photoconductor 150 shown in FIG. The protective layer 5 also has the same structure as the protective layer 5 of the photoconductor 130 shown in FIG.

[Eighth Embodiment] FIG. 4A is a sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention.

The electrophotographic photosensitive member 170 shown in FIG.
1A except that the protective layer 5 is provided on the photosensitive layer 6, the photosensitive layer 6 has a single layer structure, and the undercoat layer 42 is provided between the photosensitive layer 6 and the intermediate layer 4. It has the same structure as the photographic photoreceptor 100.

Then, the undercoat layer 42 is formed as shown in FIG.
The undercoat layer 42 of the photoconductor 150 shown in FIG. The protective layer 5 also has the same structure as the protective layer 5 of the photoconductor 130 shown in FIG. Further, the photosensitive layer 6 is also the photosensitive layer 6 of the photoconductor 110 shown in FIG.
It has the same configuration as.

The preferred embodiments of the electrophotographic photosensitive member of the present invention have been described above in detail, but the electrophotographic photosensitive member of the present invention is not limited to the above embodiments.

For example, the photosensitive layer of the electrophotographic photosensitive member of the present invention includes two layers such as the photosensitive members 100, 120 and 130 shown in FIGS. 1 (a), 2 (a) and 3 (a). In the case of the constitution consisting of, in any of the cases of the single layer structure like the photoconductors 110, 130 and 150 shown in FIG. 1B, FIG. 2B and FIG. Additives such as antioxidants, light stabilizers, and heat stabilizers may be added for the purpose of preventing the deterioration of the photoreceptor due to ozone or oxidizing gas generated in step 2, or light or heat.

Examples of the antioxidants include hindered phenols, hindered amines, paraphenylenediamines, aryl alkanes, hydroquinones, spirochromans, spiroindanones and their derivatives, organic sulfur compounds and organic phosphorus compounds.

Specific examples of the antioxidant compound include 2,6-di-t-butyl-4-methyl as a phenolic antioxidant.
Phenol, styrenated phenol, n-octadecyl-3
-(3 ', 5'-Di-t-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butyl
Phenol), 2-t-butyl-6- (3'-t-butyl-5'-methyl-
2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-t-butyl-phenol), 4,4'-thio-bis- (3-methyl 6 -t-butylphenol), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- (3 ', 5'-di- t-butyl-4'-hydroxy-phenyl)
Propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-
4-Hydroxy-5-methylphenyl) propionyloxy]
-1,1-Dimethylethyl] -2,4,8,10-tetraoxaspiro
[5,5] Examples include undecane.

As the hindered amine compound, bis
(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3,5 -Di-t-butyl-4-hydroxyphenyl)
Propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4
-Hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5 ] Undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6 succinate -Tetramethylpiperidine polycondensate, poly [[6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl] [(2,2,6, 6-Tetramethyl-4-piperidyl) imino] hexamethylene [(2,3,6,6
-Tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-
Butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N'-bis
(3-Aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6, -pentamethyl-4piperidyl) amino]-
Examples thereof include 6-chloro-1,3,5-triazine condensate.

Examples of the organic sulfur antioxidants include dilauryl-3,3'-thiodipropionate and dimyristyl-3,3'-
Thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thiopropionate), ditridecyl-3,3'-thiodipropionate, 2-mercaptobenz Examples include imidazole. Examples of organophosphorus antioxidants include trisnonylphenylphosphite, triphenylphosphite, and tris (2,4-di-t-butylphenyl) -phosphite.

Organic sulfur-based and organic phosphorus-based antioxidants are 2
It is said to be a secondary antioxidant, and when used in combination with a primary antioxidant such as a phenol type or amine type, a synergistic effect can be obtained.

Examples of the light stabilizer include benzophenone-based, benzotriazole-based, dithiocarbamate-based and tetramethylpiperidine-based derivatives. For example,
As a benzophenone light stabilizer, 2-hydroxy-4-
Methoxy benzophenone, 2-hydroxy-4-octoxy benzophenone, 2,2′-di-hydroxy-4-methoxy benzophenone and the like can be mentioned.

Examples of the benzotriazole-based light stabilizer include 2-(-2'-hydroxy-5'methylphenyl-)-benzotriazole and 2- [2'-hydroxy-3 '-(3'',4').',5'',6''-
Tetra-hydrophthalimido-methyl) -5'-methylphenyl] -benzotriazole, 2-(-2'-hydroxy-3'-t-butyl 5'-methylphenyl-)-5-chlorobenzotriazole, 2- ( 2'-hydroxy-3'-t-butyl 5'-methylphenyl
-)-5-Chlorobenzotriazole, 2- (2'-hydroxy-
3 ', 5'-t-butylphenyl-)-benzotriazole, 2- (2'
-Hydroxy-5'-t-octyl phenyl) -benzotriazole, 2- (2'-hydroxy 3 ', 5'-di-t-amyl phenyl
-)-Benzotriazole and the like.

Other compounds include 2,4, di-t-butylphenyl 3 ', 5'-di-t-butyl-4'-hydroxybenzoate and nickel dibutyl-dithiocarbamate.

The photosensitive layer 6 may contain at least one electron-accepting substance for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

Examples of usable electron accepting substances are succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene. , M-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like.

Of these, fluorenone type, quinone type, and benzene derivatives having an electron-withdrawing substituent such as —Cl, —CN, and —NO ₂ are particularly preferably used. Further, a small amount of silicone oil can be added to the coating liquid for forming the photosensitive layer of the present invention as a leveling agent for improving the smoothness of the coating film.

The electrophotographic photoreceptor of the present invention described above is a laser beam printer that emits near infrared light or visible light, a digital copying machine, an LED printer,
It can be mounted in an electrophotographic apparatus such as a laser facsimile, or a process cartridge provided in such an electrophotographic apparatus. Further, the electrophotographic photoreceptor of the present invention can be used together with a one-component or two-component regular developer or reversal developer. Further, the electrophotographic photosensitive member of the present invention can obtain good characteristics with less current leakage even when mounted on a contact charging type electrophotographic apparatus using a charging roller or a charging brush.

Next, an electrophotographic apparatus and a process cartridge equipped with the electrophotographic photosensitive member of the present invention will be described.

FIG. 5 is a sectional view schematically showing the basic structure of a preferred embodiment of the electrophotographic apparatus of the present invention. Figure 5
In the electrophotographic apparatus 200 shown in FIG. 1, the electrophotographic photosensitive member 7, a charging unit 8 that charges the electrophotographic photosensitive member 7 by a corona discharge method, a power source 9 connected to the charging unit 8, and a charging unit 8 are charged. Exposure means 10 for exposing the electrophotographic photoreceptor 7, developing means 11 for developing the portion exposed by the exposure means 10, and transfer means 12 for transferring the image developed by the developing means 11 to the electrophotographic photoreceptor 7. A cleaning device 13, a static eliminator 14, and a fixing device 15 are provided. The charging unit 8 is not particularly limited, but examples thereof include a corotron and a scorotron.

FIG. 6 is a sectional view schematically showing the basic structure of another embodiment of the electrophotographic apparatus of the present invention shown in FIG.

The electrophotographic apparatus 210 shown in FIG. 6 is provided with the charging means 8 for charging the electrophotographic photosensitive member 7 by the contact method, but the electrophotographic apparatus 200 shown in FIG.
It has the same configuration as. In particular, in an electrophotographic apparatus which employs a contact type charging means in which an AC voltage is superimposed on a DC voltage, it can be preferably used because it has excellent durability. In this case, the static eliminator 14 may not be provided in some cases.

The charging means (charging member) 8 is arranged so as to be in contact with the surface of the photoconductor 7 and uniformly applies a voltage to the photoconductor to charge the surface of the photoconductor to a predetermined potential. The charging means 8 includes a metal such as aluminum, iron or copper,
Conductive polymer materials such as polyacetylene, polypyrrole, polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, etc. A dispersion of metal oxide particles such as copper, silver iodide, zinc sulfide, silicon carbide, and metal oxide can be used.

Examples of this metal oxide include Z ₂ O, SnO ₂ and T.
Examples thereof include iO ₂ , In ₂ O ₃ , MoO _{3 and the} like, or composite oxides thereof. The charging means 8 may be made of an elastomer material containing perchlorate to give conductivity.

Further, the charging means 8 may be provided with a coating layer on its surface. As the material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinyl pyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine and the like are used alone or in combination. It is also possible to use an emulsion resin material, for example, an acrylic resin emulsion, a polyester resin emulsion, polyurethane, especially an emulsion resin synthesized by soap-free emulsion polymerization.

Conductive agent particles may be dispersed in these resins in order to adjust the resistivity, or an antioxidant may be contained in order to prevent deterioration. Also,
The emulsion resin may contain a leveling agent or a surfactant in order to improve the film-forming property when forming the coating layer. Examples of the shape of the contact charging member include a roller type, a blade type, a belt type and a brush type.

The electric resistance value of the charging means 8 is preferably 10 ² to 10 ¹⁴ Ωcm, more preferably 10 ² to 10 ¹² Ωcm.
The range is good. The voltage applied to the contact charging member may be DC or AC. Also, direct current
+ It can also be applied in the form of alternating current.

Further, FIG. 7 is a sectional view schematically showing the basic structure of a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 is integrated with the electrophotographic photoreceptor 7 by combining the charging means 8, the developing means 11, the cleaning device (cleaning means) 13, the opening portion 18 for exposure, and the static eliminator 14 using the mounting rail 16. It has been transformed.

Then, this process cartridge 300
Is detachable from the main body of the electrophotographic apparatus, which includes the transfer unit 12, the fixing device 15, and other components (not shown), and constitutes the electrophotographic apparatus together with the main body of the electrophotographic apparatus. .

[0179]

EXAMPLES The contents of the electrophotographic photosensitive member, the process cartridge and the electrophotographic apparatus of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. is not.

Example 1 A photoconductor having the same structure as the electrophotographic photoconductor 100 shown in FIG. 1A was produced by the following procedure.

First, zinc oxide (E017, manufactured by Teika): 4
1 part by mass, curing agent (blocked isocyanate Sumidule 3175, manufactured by Sumitomo Bayern Urethane Co.): 12 parts by mass, butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.): 6 parts by mass, methyl ethyl ketone: 52 parts by mass , Silicone Ball Tospearl 120 (manufactured by Toshiba Silicone Co., Ltd.): 3 parts by mass and silicone oil SH29P as a leveling agent
A (manufactured by Toray Dow Corning Silicone Co., Ltd.): 100 ppm was mixed and dispersed in a batch type mill for 10 hours to obtain an intermediate layer coating solution.

This coating solution was prepared by dip coating to have a diameter of 30 m.
m, 1 mm thick aluminum base material (conductive support layer)
It was applied on the surface and dried and cured at 150 ° C. for 30 minutes to form an intermediate layer having a layer thickness of 18 μm.

Next, a photosensitive layer having a two-layer structure was formed on the intermediate layer.

First, the Bragg angle (2θ ± 0.2 of the X-ray diffraction spectrum using Cuk α-ray as the charge-generating substance is used.
°) is at least 7.4 °, 16.6 °, 25.5 °,
Gallium phthalocyanine chloride having a diffraction peak at a position of 28.3 °: 15 parts by mass, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.) serving as a binder resin, n-butylacetate: Thirty
The mixture consisting of 0 parts by mass was dispersed in a sand mill for 4 hours using 1 mmφ glass beads.

The obtained dispersion liquid is applied as a coating liquid for forming a charge generating layer onto the intermediate layer by dip coating and dried to give a layer thickness of 0.
A 2 μm charge generation layer was formed.

Further, 4 parts by mass of N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] biphenyl-4,4'-diamine: bisphenol Z polycarbonate resin ( Viscosity average molecular weight 40,000): 6
And 80 parts by mass of chlorobenzene were added and dissolved.

The obtained dispersion liquid was applied as a coating liquid for forming a charge transport layer onto the charge generating layer by dip coating, and dried at 130 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 25 μm.

Incidentally, FIG. 8 shows an SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Example 1. The zinc oxide particles had an average particle diameter of 70 nm and a maximum primary particle diameter of 180 nm. It was confirmed that the zinc oxide particles did not include coarse particles having a maximum primary particle diameter of 300 nm or more.

(Example 2, Comparative Examples 1 to 3) Each electrophotographic photosensitive member was produced in the same procedure as in Example 1 except that the zinc oxide particles were changed to the particles shown in SEM photographs in FIGS. 9 to 12. .

That is, as shown in FIG. 9, the zinc oxide particles (MZ300, manufactured by Teika Co., Ltd.) contained in the intermediate layer of the electrophotographic photosensitive member of Example 2 had an average particle diameter of 30 n.
m, and the maximum primary particle diameter was 80 nm.
The zinc oxide particles have a maximum primary particle size of 300 nm.
It was confirmed that the above coarse particles were not included.

Further, as shown in FIG. 10, the zinc oxide particles (Nanotech ZnO, manufactured by CI Kasei Co., Ltd.) contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 1 had an average particle diameter of 60 nm, Maximum primary particle size is 550 nm
Met. The zinc oxide particles contained coarse particles having a maximum primary particle size of 300 nm or more.

Further, as shown in FIG. 11, the zinc oxide particles (Nanotech ZnO, manufactured by CI Kasei Co., Ltd.) contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 2 had an average particle diameter of 70 nm, The maximum primary particle size is 500 nm
Met. The zinc oxide particles contained coarse particles having a maximum primary particle size of 300 nm or more.

As shown in FIG. 12, the zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 3 (zinc oxide type 1, manufactured by Houseitec Co., Ltd.) have an average particle diameter of 250 nm. Yes, the maximum primary particle size is 500 nm
Met. The zinc oxide particles contained coarse particles having a maximum primary particle size of 300 nm or more.

Example 3 A photoconductor having the same structure as the electrophotographic photoconductor 100 shown in FIG. 1A was manufactured by the following procedure.

First, the zinc oxide particles shown in FIG. 8: 35 parts by mass, butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.): 10 parts by mass, and a curing agent (blocked isocyanate Sumijour 3175, Sumitomo Bayern Urethane). (Made by the company): 10 parts by mass,
Silicone Ball Tospearl 120 (manufactured by Toshiba Silicone Co., Ltd.): 5 parts by mass, methyl ethyl ketone: 50 parts by mass, and silicone oil SH29PA as a leveling agent
(Manufactured by Toray Dow Corning Silicone Co., Ltd.): 0.1 part by mass was mixed and dispersed in a batch type mill for 2 hours to obtain an intermediate layer coating solution.

This coating solution was applied by dip coating to give 30 mmφ ×
It was applied on an aluminum base material (conductive support layer) having a thickness of 404 mm and a thickness of 1 mm, and dried and cured at 150 ° C. for 30 minutes to form an intermediate layer having a layer thickness of 20 μm.

Next, a photosensitive layer having a two-layer structure was formed on the intermediate layer.

First, as the charge generating substance, the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cuk α ray is at least 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1.
Hydroxyl gallium phthalocyanine having a diffraction peak at the 2 °, 28.1 ° position: 15 parts by mass, butyral resin as a binder resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.): 10 parts by mass, n-butyl alcohol 300: parts by mass The mixture was dispersed on a sand mill for 4 hours.

The obtained dispersion liquid is applied as a coating liquid for forming a charge generating layer onto the intermediate layer by dip coating and dried to give a layer thickness of 0.2.
A charge generation layer of μm was formed.

Further, di (3,4-dimethylphenyl) (4-phenylphenyl) amine: 2 parts by mass and N, N'-diphenyl-
N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,
4'-diamine: 2 parts by mass and bisphenol Z polycarbonate (average molecular weight 40,000): 6 parts by mass, tetrahydrofuran: 80 parts by mass and 2,6-di-t-butyl-4-methylphenol: 0.2 parts by mass, respectively. Part and dissolved.

The obtained dispersion liquid was applied as a coating liquid for forming a charge transport layer onto the charge generation layer by dip coating, and dried at 120 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 18 μm.

(Example 4 and Comparative Examples 4 to 6) Table 2 described later
As shown in FIG. 7, each electrophotographic photosensitive member was produced by the same procedure as in Example 3 except that the zinc oxide particles were changed to the particles shown in SEM photographs in FIGS.

Example 5 A photoconductor having the same structure as the electrophotographic photoconductor 140 shown in FIG. 3A was manufactured by the following procedure.

First, the zinc oxide particles shown in FIG. 8 were surface-coated with a silane coupling agent (KBM603, manufactured by Shin-Etsu Chemical Co., Ltd. (the amount of the coupling agent used: 12.5% by mass relative to the zinc oxide particles). Particles: 50 parts by mass, butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.): 6 parts by mass, curing agent (blocked isocyanate Sumijour 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 10 parts by mass, silicone balls
Tospar 120 (manufactured by Toshiba Silicone Co., Ltd.): 2 parts by mass, silicone oil SH29PA (manufactured by Toray Dow Corning Silicone Co., Ltd.) serving as a leveling agent: 0.1 parts by mass, and n-butyl alcohol: 50 parts by mass are mixed to prepare a batch type Dispersion was performed for 10 hours in a mill to obtain a coating liquid for intermediate layer.

This coating solution was applied by dip coating to obtain 80 mmφ ×
It was applied on an aluminum substrate (conductive support layer) having a thickness of 340 mm and a thickness of 1 mm, and dried and cured at 150 ° C. for 30 minutes to form an intermediate layer having a layer thickness of 20 μm.

Next, an undercoat layer was formed on the intermediate layer.

First, 4 parts by mass of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 170 parts by mass of n-butyl alcohol and 30 parts by mass of organic zirconium compound (acetylacetone zirconium butyrate). And a mixture of organosilane compounds (γ-
3 parts by mass of (aminopropyltriethoxysisilane) were mixed and stirred to obtain a coating liquid for forming an undercoat layer.

The coating liquid for forming the undercoat layer was coated on the intermediate layer by a dip coating method, and air-dried at room temperature for 5 minutes,
The temperature was raised at 50 ° C. for 7 minutes. Then, the conductive support layer and the intermediate layer are integrated and heated at 50 ° C. for 7 minutes, and then placed in a constant temperature and humidity bath of 85% RH (dew point 47 ° C.) at 50 ° C. and humidified for 10 minutes. Curing acceleration treatment was performed. Then, this was placed in a hot air drier and dried at 135 ° C. for 10 minutes to form an undercoat layer on the intermediate layer.

Next, a photosensitive layer having a two-layer structure was formed on the undercoat layer.

First, the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cuk α-ray as the charge-generating substance.
Has a diffraction peak at least at the positions of 9.5 °, 11.7 °, 15 °, 24.1 °, 27.3 °: 15
By weight, butyral resin (BX-
1, Sekisui Chemical Co., Ltd.): 10 parts by mass, n-butyl alcohol: 300 parts by mass, a mixture was dispersed for 2 hours with a Dyno mill.

The obtained dispersion liquid is applied as a coating liquid for the charge generation layer onto the undercoat layer by dip coating and dried to give a layer thickness of 0.2 μm.
m charge generating layer was formed.

Further, α-phenylstilbene compound:
4 parts by mass and bisphenol Z polycarbonate (molecular weight 4
10,000 parts: 6 parts by mass were added to tetrahydrofuran: 80 parts by mass and 2,6-di-t-butyl-4-methylphenol: 0.2 parts by mass, respectively, and dissolved.

The resulting dispersion was applied as a coating solution for forming a charge transport layer onto the charge generation layer by dip coating, and dried at 120 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 3018 μm.

(Example 6 and Comparative Examples 7 to 9) Table 3 described later.
Each electrophotographic photosensitive member was produced by the same procedure as in Example 5, except that the zinc oxide particles were changed to the particles shown in SEM photographs in FIGS.

[Electrophotographic Characteristic Evaluation Test of Electrophotographic Photosensitive Member] The electrophotographic photosensitive members of Examples 1 to 6 and Comparative Examples 1 to 9 have the same structure (having a contact charging device) as shown in FIG. Full color printer (C2220DocuPrin
(T, manufactured by Fuji Xerox Co., Ltd.) and the print image quality was examined to evaluate the electrophotographic characteristics of each electrophotographic photosensitive member as follows.

(1) Evaluation by comparison of the degree of fogging in the initial stage of use The surface potential of the photosensitive member is 700 V, and the developing bias voltage is 65.
An image was printed on paper under a severe condition where stress was more likely to occur than the normal setting, which was 0 V, and stress was applied. The degree of fogging of the image obtained after printing was evaluated based on the following evaluation criteria.
The results are shown in Tables 1 to 3. G0: No fogging occurred, and good image quality was obtained. G1; A level with subtle fog. G2; an intermediate level between G1 and G3. G3: A level with a light tinge. G4: Intermediate level between G3 and G5. G5: A level at which the lower color portion is violently blackened due to fogging.

(2) Characteristic evaluation during repeated use Using an electric characteristic test device for a photoconductor having a charging device and an exposure device, under a normal temperature and normal humidity (20 ° C., 40% RH) environment, a grid applied voltage of −700 V The charging potential A of the surface of each electrophotographic photosensitive member was measured when each electrophotographic photosensitive member was charged by the scorotron charger of No. 2.

Next, using a 780 nm semiconductor laser,
10 mJ / m for each electrophotographic photosensitive member 1 second after being charged
Discharge was performed by irradiating light of No. ² and the potential B after light decay of the surface of each electrophotographic photosensitive member at this time was measured.

Subsequently, after 3 seconds from the discharge, each electrophotographic photosensitive member is irradiated with red LED light of 50 mJ / m ² to remove electricity, and the residual potential C on the surface of each electrophotographic photosensitive member at this time is discharged.
I checked.

Here, the higher the value of the potential A, the higher the receptive potential of the electrophotographic photosensitive member, and therefore the higher the contrast can be made. Further, the lower the value of the potential B, the higher the sensitivity of the electrophotographic photosensitive member. Further, the lower the value of the potential C is, the less the residual potential is, and it is evaluated as an electrophotographic photosensitive member having less image memory and so-called fog.

The initial charging potential A is -700V, the exposure light amount is adjusted to set the background potential to -200V,
The charging conditions and the exposure amount were set, and the above operation was repeated, and the number of repeated cycles until the background potential became half (-450 V) to the contrast potential was measured. The number of the repeated cycles was defined as the life of the photoreceptor, and the characteristics of the photoreceptor during repeated use were evaluated. The results are shown in Tables 1 to 3.

(3) Evaluation by Comparison of Degree of Occurrence of Fogging after Repeated Use At the time when the number of repeated cycles reaches 200 kcycle, the photoconductor is mounted on the above-mentioned full-color printer,
The surface potential of the photoconductor was set to -700 V, the developing bias voltage was set to -650 V, and the image was printed on paper under stressed and harsh conditions in which fogging is more likely to occur than in the normal setting. The degree of fogging of the image obtained after printing was evaluated based on the evaluation criteria of G0 to G5 described above. These results are shown in Table 1 to Table 3.
Shown in.

[0223]

[Table 1]

[0224]

[Table 2]

[0225]

[Table 3]

[0226]

As described above, according to the electrophotographic photosensitive member of the present invention, it is possible to obtain high durability and high resolution quality capable of sufficiently preventing the deterioration of electric characteristics due to repeated use. it can. By including this, it is possible to provide a process cartridge and an electrophotographic apparatus that can obtain high resolution quality even when repeatedly used for a long period of time.

[Brief description of drawings]

FIG. 1A is a sectional view showing a first embodiment of an electrophotographic photosensitive member of the present invention, and FIG. 1B is a sectional view showing a second embodiment of an electrophotographic photosensitive member of the present invention. is there.

2A is a sectional view showing a third embodiment of the electrophotographic photosensitive member of the present invention, and FIG. 2B is a sectional view showing a fourth embodiment of the electrophotographic photosensitive member of the present invention. is there.

3A is a sectional view showing a fifth embodiment of the electrophotographic photosensitive member of the present invention, and FIG. 3B is a sectional view showing a sixth embodiment of the electrophotographic photosensitive member of the present invention. is there.

4A is a sectional view showing a seventh embodiment of the electrophotographic photosensitive member of the present invention, and FIG. 3B is a sectional view showing an eighth embodiment of the electrophotographic photosensitive member of the present invention. It is a figure.

FIG. 5 is a sectional view schematically showing the basic structure of a preferred embodiment of the electrophotographic apparatus of the present invention.

FIG. 6 is a sectional view schematically showing the basic structure of another embodiment of the electrophotographic apparatus of the present invention shown in FIG.

FIG. 7 is a sectional view schematically showing the basic structure of a preferred embodiment of the process cartridge of the present invention.

8 is a SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Example 1. FIG.

9 is an SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Example 2. FIG.

10 is an SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 1. FIG.

11 is an SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 2. FIG.

12 is an SEM photograph of zinc oxide particles contained in the intermediate layer of the electrophotographic photosensitive member of Comparative Example 3. FIG.

[Explanation of symbols]

1 ... Charge generation layer, 3 ... Conductive support layer, 4 ... Intermediate layer, 5
... protective layer, 6 ... photosensitive layer, 7 ... electrophotographic photoreceptor, 8 ... charging means, 9 ... power source, 10 ... exposure means, 11 ... developing means, 1
2 ... Transfer means, 13 ... Cleaning device, 14 ... Static eliminator, 16 ... Mounting rail, 18 ... Opening for exposure, 42 ... Undercoat layer, 100, 110, 120, 130,
140, 150, 160, 170 ... Electrophotographic photoreceptor, 2
00 ... Electrophotographic device, 210 ... Electrophotographic device, 300 ...
Process cartridge.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Nakamura             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Michiko Aida             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Yukiko Kamijo             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Masahiro Iwasaki             Fuji Zero, 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture             X Co., Ltd. F-term (reference) 2H035 CA07 CB02 CD14                 2H068 AA21 AA45 AA48 CA22 FA01                       FA27

Claims (5)

[Claims] 1. A conductive support layer, a photosensitive layer containing a pigment, and an intermediate layer disposed between the conductive support layer and the photosensitive layer, wherein the intermediate layer is , Zinc oxide particles and a binder resin are contained, and the zinc oxide particles contained in the intermediate layer have a maximum primary particle diameter of less than 300 nm and an average particle diameter of 20 to 200 nm. An electrophotographic photosensitive member characterized by being present. 2. The electrophotographic photoreceptor according to claim 1, wherein the intermediate layer has a layer thickness of 15 to 50 μm. 3. The electrophotographic photosensitive member according to claim 2, wherein the intermediate layer has a layer thickness of more than 20 μm and not more than 50 μm. 4. An electrophotographic apparatus main body, comprising the electrophotographic photosensitive member according to claim 1 and at least one unit of a charging unit, a developing unit, a cleaning unit and a charge eliminating unit, which are integrated with each other. A process cartridge that is removable. 5. The electrophotographic photosensitive member according to claim 1, a charging unit that charges the electrophotographic photosensitive member, and an exposure that exposes the electrophotographic photosensitive member that is charged by the charging unit. An electrophotographic apparatus comprising: a developing unit, a developing unit that develops a portion exposed by the exposing unit, and a transfer unit that transfers the image developed on the electrophotographic photosensitive member by the developing unit.