JP2000314975A - Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable potential characteristic and an image in all environments from low temperature and low humidity to high temperature and high humidity with high sensitivity, good charging characteristics and small dark decay. An object of the present invention is to provide an electrophotographic photosensitive member, a process cartridge using the electrophotographic photosensitive member, and an electrophotographic apparatus. SOLUTION: In an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer, an undercoat layer is provided between the intermediate layer and the support, and the undercoat layer and the intermediate layer are sol-gel. An electrophotographic photosensitive member which is a film formed by a method, a process cartridge using the electrophotographic photosensitive member, and an electrophotographic apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus, and more particularly, to an electrophotographic photosensitive member having an intermediate layer containing a specific material and an undercoat layer. And a process cartridge having the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Generally, in a Carlson type electrophotographic photoreceptor, stability of dark area potential and light area potential is important for forming a fixed image density and an image free from background contamination when charging and exposure are repeated. It has become. For this reason, it has been proposed to provide a layer having a function as a barrier layer between the photosensitive layer and the support.

Further, there has been proposed a layer having a laminated structure in which a photosensitive layer is functionally separated into a charge generation layer and a charge transport layer. Generally, the charge generation layer is provided as an extremely thin layer having a thickness of about 0.5 μm, for example. Therefore, defects, dirt, deposits, scratches, and the like on the support surface cause the charge generation layer to have a non-uniform film thickness. Furthermore, recent efforts to improve image quality have revealed that it is effective to reduce the thickness of the charge transport layer. Therefore, if the thickness of the charge generation layer is non-uniform, it becomes more difficult to control the thickness of the charge transport layer, and the sensitivity of the photoreceptor becomes uneven, so that the charge generation layer should be as uniform as possible. Has been requested.

[0004] For this reason, it has been proposed to provide an intermediate layer having a function as a barrier layer and a function as an adhesive layer between the charge generation layer and the support.

[0005] Conventional layers provided between the photosensitive layer and the support include polyamides (JP-A-46-47344 and JP-A-52-25638) and polyesters (JP-A-52-20836). JP-A-54-267
No. 38), polyurethane (JP-A-49-10044).
JP, JP-A-53-89435), casein (JP-A-55-103556), polypeptide (JP-A-53-48523), polyvinyl alcohol (JP-A-52-100240) , Polyvinyl pyrrolidone (JP-A-48-30936), vinyl acetate-ethylene copolymer (JP-A-48-26141), and maleic anhydride ester polymer (JP-A-52-1).
0138), polyvinyl butyral (Japanese Unexamined Patent Publication No.
-90639, JP-A-58-106549), and a quaternary ammonium salt-containing polymer (JP-A-51-106549).
126149, JP-A-56-60448), ethyl cellulose (JP-A-55-143564) and the like are known.

In an electrophotographic photoreceptor using the above-described material as an intermediate layer, the resistance of the intermediate layer changes due to a change in temperature and humidity. It was difficult to obtain stable potential characteristics and image quality.

In addition, when the charge transport layer is thinned for the purpose of increasing the resolution, the chargeability is reduced by repeated use, and black spot-like defects (black spots) and fog are more likely to occur on the image. When the resistance of the intermediate layer fluctuates due to a change in humidity, the influence on the image tends to be more remarkable. Therefore, as the photoconductor becomes thinner, it is necessary to improve the intermediate layer at a higher level.

Japanese Patent Application Laid-Open No. 61-94057 discloses an intermediate layer containing an organometallic compound as a main component.
JP-287275 discloses an intermediate layer formed of a metal oxide formed by a vacuum thin film manufacturing method. Since the conductivity of the organic intermediate layer is caused by the presence of ions, the organic intermediate layer is easily affected by moisture, and the resistance from high temperature and high humidity to low temperature and low humidity cannot be controlled with a small fluctuation width. On the other hand, the inorganic intermediate layer has less environmental fluctuation than the organic material, the resistance value can be controlled by doping, and the electric (electronic) matching with the photosensitive layer is performed by controlling the ionization potential. There are advantages such as being able to.

However, the intermediate layer containing the above-mentioned organometallic compound as a main component is still inadequate in that many organic substances remain and many impurities and defects are present. Therefore, the film has a large environmental change in film resistance and a low ionization potential, and has problems such as a large dark decay in electrophotographic characteristics.

The intermediate layer made of a metal oxide formed by a vacuum thin film manufacturing method has no problem in the tightness of the film, but has a composition for obtaining a sufficient ionization potential.
Defect control was difficult.

Further, if there are many lattice defects as in the intermediate layer formed by the above-described method, the metal element in the support is doped into the intermediate layer, or the metal element of the support is removed during the firing process. There is a problem that the resistance of the intermediate layer fluctuates and the effect as a barrier layer is reduced, and the environmental characteristics and electrophotographic characteristics of the photoreceptor are easily deteriorated.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity, good charging characteristics and low dark decay, a process cartridge using the electrophotographic photosensitive member, and an electrophotographic apparatus. It is to be.

Another object of the present invention is to provide an electrophotographic photosensitive member capable of obtaining images with stable potential characteristics and images in all environments from low temperature and low humidity to high temperature and high humidity, and a process using the electrophotographic photosensitive member. An object of the present invention is to provide a cartridge and an electrophotographic apparatus.

[0014]

According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer on a conductive support via an intermediate layer, comprising an undercoat layer between the intermediate layer and the support. Also provided are an electrophotographic photosensitive member in which an undercoat layer and an intermediate layer are films formed by a sol-gel method, a process cartridge using the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0015]

Embodiments of the present invention will be described below in detail.

The undercoat layer is formed by applying a hydrolyzate of a sol-gel on a conductive support and baking it. The hydrolyzate of the sol-gel is prepared by adding a starting material to a solvent, adding an acid or a base, and hydrolyzing at an appropriate pH, temperature and time.

As a starting material for the undercoat layer, an alkoxide of silicon is particularly preferred in view of the denseness of the resulting film and the adhesion between the support and the intermediate layer. Preferred undercoat layers include silicon oxide films.

The thickness of the undercoat layer used in the present invention is preferably from 100 to 1 μm, and more preferably from 100 to 1000 in that the semiconductor characteristics of the intermediate layer are not impaired.

The intermediate layer is formed by applying a sol-gel hydrolyzate and baking the same as in the undercoat layer. The formed intermediate layer is an oxide film of a metal exhibiting the characteristics of an n-type semiconductor and selected from groups 2a, 2b, 3b, 4a, and 4b of the periodic table. A preferred oxide layer is a zinc oxide film.

As the starting material of the intermediate layer, 2 in the periodic table is used.
Examples include alkoxides or chelate compounds of metals selected from a, 2b, 3b, 4a, and 4b groups, particularly zinc alkoxides, halides, oxides, hydroxides, dialkylamides, organic acids and acid anhydrides. Ester, β-diketone or β-ketoamine or β-
Chelates with ketoesters and reaction products with alkanolamines are used. Preferably, Zn (OAc) ₂
・ Carboxylic acid esters such as 2H ₂ O, Zn (AcA
c) Chelates such as ₂ · H ₂ O and alkyl zincs, particularly preferably alkyl zincs, are mentioned in view of the tightness of the membrane. These starting materials can be used in combination of two or more.

In general, zinc oxide is represented by ZnO, but a composition deviating from the stoichiometric composition may be produced depending on the conditions of formation.

The thickness of the intermediate layer used in the present invention is preferably from 100 to 10 μm, more preferably from 500 to 10 μm.
5 μm.

As the solvent in the sol-gel method of the present invention, those that dissolve the starting materials can be used. Representative solvents include alcohols, ketones such as β-diketone, and toluene and xylene. Particularly good in the present invention is, for example, Zn (O
Ac) ₂ · 2H ₂ O in ethanol, 1-butanol, 2
-Ethoxyethanol, diethylene glycol, Zn
(AcAc) ₂ · H ₂ O in ethanol, 2-ethoxyethanol, ethyl acetate, ethyl acetate and ethanol in zinc octylate, a zinc naphthenate n- butanol, the alkyl zinc sec- butanol, methyl acetoacetate, ethylene glycol monomethyl Phenyl ether.
Among these solvents, besides those used merely for dissolving the starting materials, those used for the purpose of causing alcohol exchange reaction with the starting materials, and those used for controlling the rate of hydrolysis reaction .

The catalyst used for the hydrolysis may be an acid, a base, or the like, but it is preferable in the present invention that zinc (Zn (OAc) ₂ .2H ₂ O) is acetic acid, Zn (Ac
Ac) ₂ · H ₂ O and alkyl zinc were hydrochloric acid.

As a coating method, a method such as spray coating, dip coating, knife coating, roll coating and the like is appropriately used.
The baking is performed at normal temperature or by heating. The atmosphere can be an air atmosphere, a nitrogen atmosphere, an oxygen atmosphere, an argon atmosphere, or the like.

By using the above-mentioned sol-gel method, uniform thinning of the intermediate layer and the undercoat layer can be easily and conveniently achieved, and the control of the film thickness accompanying the thinning of the photosensitive layer is improved.

Further, the electrophotographic photoreceptor of the present invention uses the above-mentioned metal oxide film for an intermediate layer and an undercoat layer,
It is possible to prevent environmental changes such as a rise in residual potential under low temperature and low humidity and a drop in dark area potential due to a decrease in barrier function under high temperature and high humidity.

Since the metal oxide film of the present invention hardly varies in volume resistance under each environment, an electrophotographic photoreceptor with little environmental change can be obtained when it is used as an intermediate layer. The resistance of a normal organic resin is reduced by about three digits from normal temperature and normal humidity to high temperature and high humidity, but the metal oxide as an inorganic material hardly changes.

Further, since the metal oxide film formed by the sol-gel method is a uniform and dense film without pinholes and the like, it is not affected by environmental changes, especially humidity, and has a silicon oxide film as an undercoat layer. When a film is used, it is considered that the metal element in the support is prevented from being doped into the intermediate layer, or the metal element of the support is prevented from diffusing into the intermediate layer during the firing process. Further, by using a sol-gel metal oxide film having high heat resistance for the undercoat layer, the intermediate layer can be fired at a high temperature, and the crystallinity of the intermediate layer film can be improved.

In particular, since the metal oxide film used for the intermediate layer of the present invention has the characteristics of an n-type semiconductor having a high electron-transporting property, the carrier-transporting property from the photosensitive layer to the conductive support can be improved. This makes it possible to prevent the injection of holes from the conductive support into the photosensitive layer without impairing the image quality.

The support used in the present invention may be any one having conductivity, for example, aluminum,
Metals such as copper, chromium, nickel, zinc, and stainless steel molded on drums or sheets; metal foils such as aluminum and copper laminated on plastic films; aluminum, indium oxide, tin oxide, etc. deposited on plastic films Or a metal, a plastic film, paper, etc. provided with a conductive layer by applying a conductive material alone or with an appropriate binder resin.

The conductive material used for the conductive layer includes metal powders such as aluminum, copper, nickel and silver; metal foils and short metal fibers; conductive metal oxides such as antimony oxide, indium oxide and tin oxide. , Polypyrrole, polyaniline, polymer conductive materials such as polymer electrolytes, carbon fiber, carbon black, graphite powder, organic and inorganic electrolytes, or conductive powders whose surfaces are coated with these conductive materials. .

As the binder resin used for the conductive layer, polyamide, polyester, acrylic resin,
Polyamino acid ester, polyvinyl lactate, polycarbonate, polyvinyl formal, polyvinyl butyral,
Examples thereof include thermoplastic resins such as polyvinyl alkyl ether, polyalkylene ether, and polyurethane elastomer, and thermosetting resins such as thermosetting polyurethane, phenol resin, and epoxy resin.

The mixing ratio between the conductive material and the binder resin is about 5: 1 to 1: 5. This mixing ratio is determined in consideration of the resistance value, surface properties, coating suitability, and the like of the conductive layer.
When the conductive material is a powder, a mixture with a binder resin is prepared and used using a ball mill, a roll mill, a sand mill, or the like.

As other additives, a surfactant, a silane coupling agent, a titanate coupling agent, a silicone oil, a silicone leveling agent and the like may be added.

In the present invention, the photosensitive layer may be a single layer type or a laminated type in which the function is separated into a charge generation layer and a charge transport layer.

The charge generation layer of the laminated structure type photoreceptor is made of an azo pigment such as Sudan Red or Diane Blue, a quinone pigment such as pyrenequinone or anthantrone, a quinolinine pigment, a perylene pigment, an indigo pigment such as indigo or thioindigo, or an azulhenium salt pigment. A copper phthalocyanine, a charge generating material such as a phthalocyanine pigment such as oxytitanium phthalocyanine is dispersed in a binder resin such as polyvinyl butyral, polystyrene, polyvinyl acetate, an acrylic resin, polyvinyl pyrrolidone, ethyl cellulose, and acetic acid-butyrate, and this dispersion liquid is dispersed. Is applied on the above-mentioned intermediate layer. The thickness of such a charge generation layer is preferably 5 μm or less, more preferably 0.05 to 2 μm.

The charge transporting layer provided on the charge generating layer comprises a polycyclic aromatic compound having a structure such as biphenylene, anthracene, pyrene or phenanthrene in a main chain or a side chain, indole, carbazole, oxadiazole, pyrazoline or the like. It is formed using a coating solution in which a charge transporting material such as a nitrogen-containing cyclic compound, a hydrazone compound, a styryl compound or the like is dissolved in a resin having a film-forming property. The reason why the charge transporting material is formed in this manner is that the charge transporting material generally has a low molecular weight and has poor film formability by itself.

As the resin having such a film forming property,
Examples include polyester, polycarbonate, polymethacrylate, and polystyrene. The thickness of the charge transport layer is preferably 5 to 40 µm, more preferably 10 to 40 µm.
30 μm.

In the present invention, an organic photoconductive polymer layer such as polyvinyl carbazole and polyvinyl anthracene, a selenium vapor deposition layer, a selenium-tellurium vapor deposition layer, an amorphous silicon layer and the like can also be used for the photosensitive layer.

In the present invention, a layer structure in which a charge generation layer is provided on the charge transport layer is also possible in addition to the above-mentioned layer structure as the structure of the photosensitive layer. In the present invention, a protective layer can be further provided on the photosensitive layer.

The protective layer is provided for the purpose of protecting the surface of the photoreceptor. Materials used for the protective layer include ABS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, and polyacetal. , Polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin , Butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin and the like.

In the protective layer, a fluorine resin such as polytetrafluoroethylene, a silicone resin, and an inorganic material such as titanium oxide, tin oxide, and potassium titanate are dispersed in these resins for the purpose of improving abrasion resistance. Can be added. As a method of forming the protective layer,
Normal coating methods are used. In addition, the thickness of the protective layer is 0.1.
About 6 to 10 μm is appropriate.

FIG. 1 is a schematic cross-sectional view of an electrophotographic photoreceptor of the present invention in which a protective layer is provided in a laminated structure having a charge generation layer and a charge transport layer.

FIG. 2 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 11 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated around an axis 12 at a predetermined peripheral speed in a direction indicated by an arrow. In the rotation process, the photosensitive member 11 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging means 13, and then output from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure. It receives image exposure light 14 that is enhanced and modulated according to the time-series electrical digital image signal of the desired image information. Thus, an electrostatic latent image corresponding to the target image information is sequentially formed on the peripheral surface of the photoconductor 11.

The formed electrostatic latent image is then transferred to developing means 1
5 and the photosensitive member 1 is fed from a paper feeding unit (not shown).
The toner image formed and carried on the surface of the photoconductor 11 is sequentially transferred by the transfer unit 16 to the transfer material 17 which is taken out and fed in synchronization with the rotation of the photoconductor 11 between the transfer member 1 and the transfer unit 16. go.

The transfer material 17 to which the toner image has been transferred is
After being separated from the photoreceptor surface and introduced into the image fixing means 18 and subjected to image fixing, it is discharged out of the apparatus as an image formed product (print, copy).

The surface of the photoreceptor 11 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 19, and is further subjected to a static elimination process by the pre-exposure light 20 from the pre-exposure means (not shown). Thereafter, it is repeatedly used for image formation. When the primary charging unit 13 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 11, primary charging means 13, developing means 15 and cleaning means 19 are integrally connected as a process cartridge. The process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 13, the developing unit 15, and the cleaning unit 19 is integrally supported with the photoconductor 11 to form a cartridge, and the cartridge can be attached to and detached from the apparatus main body using a guide unit such as the rail 22 of the apparatus main body. The process cartridge 21 can be used.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 14 is obtained by reading the reflected light or transmitted light from the original, or reading the original with a sensor and converting it into a signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as CRT printers, LED printers, faxes, liquid crystal printers, and laser plate making.

[0053]

The present invention will be described in more detail with reference to the following examples. In addition. “Parts” indicates parts by weight.

First, a specific example of the preparation of the coating liquid used for forming the undercoat layer of the present invention will be described.

"Formulation Example 1" 20 parts of an aqueous solution of tetraethylsilicate (21% by weight), 10 parts of ion-exchanged water,
A solution consisting of 0.15 part of N hydrochloric acid and 65 parts of methanol was mixed and allowed to stand for one day to form a coating liquid.

"Formulation Example 2" 20 parts of an aqueous solution of tetraethylsilicate (21% by weight), 10 parts of ion-exchanged water,
A solution composed of 0.15 part of N nitric acid and 65 parts of ethanol was mixed, and allowed to stand for one day to form a coating liquid.

Further, specific examples of the preparation of the coating liquid used for forming the intermediate layer of the present invention will be described.

[0058] "Formulation Example 3" _{Zn (OAc) 2 · 2H 2} O
After dissolving 13.5 g in a mixed solution of 62 g of water / 75 g of ethanol, 2 g of 6N hydrochloric acid was added and reflux was performed for 30 minutes. Then, 5 g of acetic acid, 10-butanol 10
g, 20 g of 2-ethoxyethanol and 5 g of diethylene glycol to prepare a 2.5 wt% ZnO solution.

"Formulation Example 4" Zn (AcAc) ₂ .H ₂ O
8.45 g was dissolved in 26.15 g of ethanol, 5.4 g of 6N hydrochloric acid was added dropwise, and the mixture was refluxed. After cooling,
It was prepared by adding 10 g of 2-ethoxyethanol, 5 g of ethyl acetate and 5 g of pure water.

Formulation Example 5 Zinc octylate (Nikka Octex Zn / mineral spirit solution) 26.7 g was prepared by diluting with 73.3 g of an equal mixture of ethyl acetate / ethanol.

"Formulation Example 6" Zinc naphthenate (Nikka Naphtex Zn / mineral spirit solution) was used as it was.

"Formulation Example 7" 75 g of zinc naphthenate (Nikkanaphtex Zn / mineral spirit solution) was added to n-
It was diluted and prepared with 25 g of butanol.

"Formulation Example 8" diethyl zinc (0.99 mol
1 / l hexane solution) 33 g of methyl acetoacetate 1
The mixture was added dropwise to a mixture of 1.61 g / sec-butanol (40.57 g). After the heat generation was stopped, 34.54 g of ethylene glycol monophenyl ether was added dropwise under a nitrogen flow, and the mixture was allowed to stand overnight. Add 0.001N hydrochloric acid 0.2
A mixed solution of 3 g / sec-butanol (59.77 g) was added dropwise to prepare.

"Formulation Example 9" A solution was prepared by diluting 150 g of a 3% ethanol solution of dipropoxybis (acetylacetonate) titanium with 40 g of sec-butanol.

Next, an embodiment will be described.

Example 1 The coating solution of Formulation Example 1 was used
After dip coating on aluminum plate (5cm x 5cm),
Baking was performed at 500 ° C. for 30 minutes in an air atmosphere to form a 0.5 μm silicon oxide film as an undercoat layer. The coating solution of Formulation Example 3 was applied onto the undercoat layer by the dipping method in the same manner as in the undercoat layer, and baked, and the thickness of the intermediate layer was 0.5 μm.
Was formed.

Next, a Bragg angle (2θ ± 0.2 °) of 23.9 ° in characteristic X-ray diffraction of CuKα was placed on the intermediate layer.
And 4 parts of oxytitanium phthalocyanine (TiOPc) having a strong peak at 27.1 °, 2 parts of polyvinyl butyral (trade name: Esrec BM-2, manufactured by Sekisui Chemical) and 80 parts of cyclohexanone in a sand mill using 1 mmφ glass beads. After dispersion for an hour, 115 parts of methyl ethyl ketone was added to obtain a charge generation layer dispersion.
This was applied on the intermediate layer by a dipping method, and the film thickness was 0.3 μm.
m of the charge generation layer was formed.

Next, 10 parts of an amine compound having the following structural formula

[0069]

Embedded image

And polycarbonate (weight average molecular weight 4
6000) was dissolved in a mixed solvent of 20 parts of dichloromethane / 40 parts of monochlorobenzene. This paint is applied on the above-mentioned charge generating layer by a dipping method,
By drying for a time, a charge transport layer having a thickness of 25 μm was formed.

The electrophotographic photoreceptor piece thus manufactured was subjected to a temperature of 20 ° C./humidity of 50% RH (relative humidity) (N /
N), temperature 15 ° C / humidity 10% RH (L / L), temperature 3
After humidity control in each environment of 0 ° C./85% RH (H / H) overnight, an electrostatic copying paper test apparatus Mode manufactured by Kawaguchi Electric Co., Ltd.
Using EP-8200, evaluation was made as follows.

First, after exposure at an illuminance of 10 lux and charge elimination, corona charging was performed at a discharge voltage of -4.5 kV, and the potential before and after holding for 3 seconds in a dark place was examined. Table 1 shows the results of the initial potential V0 (V) and the dark decay Vdd (V) for 3 seconds in each environment.

(Example 2) The support in Example 1 was replaced with an aluminum cylinder (outer diameter 30 mm, length 260 m).
An electrophotographic photoreceptor of the invention was prepared in the same manner as in Example 1, except that m) was used. The obtained electrophotographic photoreceptor was mounted on a reversal-developed electrophotographic printer, and a charging-exposure-development-transfer-cleaning process was repeated at a cycle of 6 seconds. The electrophotographic characteristics of this photoreceptor were evaluated under low-temperature and low-humidity (temperature 15 ° C./humidity 15% RH) and high-temperature and high-humidity (temperature 30 ° C./humidity 85% RH) environments.

As a result, this electrophotographic photoreceptor has a ratio Vd / Vl = 700/150 (V) between the dark potential (VD) and the light potential (VL) under low temperature and low humidity, and under high temperature and high humidity. Was Vd / Vl = 700/140 (V). That is, in both the low-temperature and low-humidity environment and the high-temperature and high-humidity environment, a large difference can be formed between the dark portion potential (VD) and the bright portion potential (VL), and sufficient contrast can be obtained. .

Further, when images were successively output on 4000 sheets of recording paper, both the dark potential and the bright potential hardly changed in any environment, and were extremely excellent without unnecessary black spot images or fog. An image with a high image quality was also obtained stably. Table 1 shows the results.

Example 3 An electrophotographic photosensitive member was prepared in the same manner as in Example 2, except that the aluminum cylinder in Example 2 was replaced with a cylinder having an outer diameter of 80 mm and the charge transport layer was 10 μm. The apparatus was mounted on a digital color copying machine having a laser beam exposure unit and a modified exposure unit for a photoreceptor, and an image output test was performed in each environment in the same manner as in Example 2.

As a result, this electrophotographic photoreceptor has a ratio Vd / Vl = 690/140 (V) of the dark portion potential (VD) and the bright portion potential (VL) under low temperature and low humidity, and under high temperature and high humidity. Was Vd / Vl = 680/130 (V). That is, in both the low-humidity and low-humidity environment and the high-temperature and high-humidity environment, a large difference can be formed between the dark portion potential (VD) and the bright portion potential (VL), and sufficient contrast can be obtained. .

Further, when images were successively output on 4000 sheets of recording paper, the dark potential and the bright potential hardly changed in any environment, and there was no unnecessary black spot image or fog. Excellent quality images were also obtained stably. Table 1 shows the results.

Example 4 An aluminum plate (5 cm × 5
cm) was applied by dip coating and baked at 500 ° C. for 30 minutes in an air atmosphere to form a silicon oxide film having a thickness of 0.5 μm as an undercoat layer. The coating liquid of Formulation Example 4 was applied on the undercoat layer by the dipping method in the same manner as in the undercoat layer, and baked to form a zinc oxide film having a thickness of 0.5 μm as an intermediate layer. Thereafter, a charge generation layer and a charge transport layer were laminated in the same manner as in Example 1 to prepare an electrophotographic photoreceptor piece, which was evaluated in the same manner as in Example 1. Table 1 shows the results.

(Examples 5 to 8) The coating liquids of Preparation Examples 5 to 8 were applied and baked on the undercoat layer of Example 1 by the dipping method in the same manner as in Example 1 to form a film as an intermediate layer. The thickness is 0.
A zinc oxide film of about 5 μm was formed. Thereafter, a charge generation layer and a charge transport layer were laminated in the same manner as in Example 1 to prepare an electrophotographic photoreceptor piece, which was evaluated in the same manner as in Example 1. Table 1 shows the results.

(Example 9) The coating solution of Formulation Example 9 was applied on the undercoat layer of Example 1 by the dipping method in the same manner as in Example 1, and baked to form an intermediate layer having a thickness of 0.1 μm. Was formed. Hereinafter, a charge generation layer and a charge transport layer were laminated in the same manner as in Example 1 to produce an electrophotographic photoreceptor piece.
Evaluation was performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 1) Instead of the zinc oxide film, the intermediate layer of Example 1 was replaced with N-methoxydimethylated 6 nylon (weight average molecular weight: 120,000, methoxydimethyl group substitution rate: 33).
%) Was used to produce an electrophotographic photoreceptor piece in the same manner as in Example 1, except that Comparative Example 1 was used. The electrophotographic photosensitive member was evaluated in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2 The same procedures as in Example 1 were carried out except that the undercoat layer was not provided and the intermediate layer of Example 1 was a zinc oxide film (thickness 0.5 μm) formed by a vacuum evaporation method. An electrophotographic photoreceptor piece was manufactured in the same manner as Comparative Example 2. The electrophotographic photosensitive member was evaluated in the same manner as in Example 1. Table 1 shows the results.

[0084]

[Table 1]

[0085]

According to the present invention, by providing an undercoat layer and an intermediate layer formed by a sol-gel method between the support and the photosensitive layer, the metal element in the support is doped into the intermediate layer. Alternatively, it is possible to prevent the metal element of the support from diffusing into the intermediate layer during the firing process, and to eliminate the fluctuation of the resistance of the intermediate layer. As a result, it is possible to obtain an electrophotographic photoreceptor having a small variation in potential due to the environment and excellent electrophotographic characteristics, and to provide a high-resolution image, particularly a high-gradation full-color image in which a photograph or the like is used. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member of the present invention.

FIG. 2 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Protective layer 2 Charge transport layer 3 Charge generation layer 4 Intermediate layer 5 Undercoat layer 6 Support 11 Photoconductor 12 Axis 13 Charging means 14 Exposure light 15 Developing means 16 Transfer means 17 Transfer material 18 Fixing means 19 Cleaning means 20 Pre-exposure Light 21 process cartridge 22 guide means

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masataka Kawahara 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H068 AA42 AA50 BA57 BA58 CA06 CA22 EA16 FA27

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support via an intermediate layer, comprising an undercoat layer between the intermediate layer and the support, wherein the undercoat layer An electrophotographic photoreceptor, wherein the intermediate layer is a film formed by a sol-gel method. 2. The electrophotographic photoreceptor according to claim 1, wherein the intermediate layer is an n-type semiconductor and is an oxide film of a metal selected from groups 2a, 2b, 3b, 4a and 4b of the periodic table. 3. The method according to claim 1, wherein the intermediate layer is a zinc oxide film.
Or the electrophotographic photosensitive member according to 2. 4. The electrophotographic photosensitive member according to claim 1, wherein the undercoat layer is a silicon oxide film. 5. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, and developing for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner. Means and at least one means selected from the group consisting of a cleaning means for recovering the toner remaining on the photoreceptor after the transfer step, and are integrally supported and detachable from the main body of the electrophotographic apparatus. Process cartridge. 6. An electrophotographic photosensitive member according to claim 1, a charging means for charging the electrophotographic photosensitive member, and image exposure of the charged electrophotographic photosensitive member to form an electrostatic latent image. Image developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member with toner, and transfer means for transferring the toner image on the electrophotographic photosensitive member onto a transfer material. Electrophotographic equipment.