JP2887057B2 - Electrophotographic photoreceptor and electrophotographic apparatus using the electrophotographic photoreceptor - Google Patents

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 and an electrophotographic apparatus using the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member basically includes a support,
And a photoconductive layer formed on the support. However, covering defects of the support, improving the coating properties of the photoconductive layer, improving the adhesion between the photoconductive layer and the support, protecting the photoconductive layer against electrical destruction, improving the chargeability, It is effective to provide an intermediate layer between the photoconductive layer and the support for improving the charge injection into the layer. Therefore, the intermediate layer in the electrophotographic photoreceptor is required to have many functions such as covering properties, adhesive properties, mechanical strength, appropriate conductivity and electrical barrier properties.

Conventionally, the following types of intermediate layers have been proposed.

(I) Resin thin film not containing conductive filler (ii) Resin thin film containing conductive filler (iii) A thin film of the above (i) laminated on the thin film of the above (ii) The thin film of i) does not contain a conductive filler and therefore has a high resistance, and must be used as a thick film to cover defects on the support. For this reason, there is a disadvantage that the residual potential at the initial stage and at the time of repeated use is increased. For the practical use of the thin film (i), defects on the support are reduced and the thickness of the intermediate layer is extremely thin. There is a need to.

On the other hand, the thin films (ii) and (iii) have an advantage that a suitable conductivity can be imparted by dispersing the conductive filler. Electrical characteristics such as resistance and dielectric constant change, which greatly affects potential characteristics and image quality. In addition, if the dispersibility of the filler is poor, the surface smoothness of the film becomes poor,
It causes coating defects. Further, if the dispersion of the filler is poor, the adhesion to the support and the mechanical strength also decrease.

Until now, as conductive fillers for the intermediate layer, metals (JP-A-58-18154), metal oxides (JP-A-54-151843), and metal nitrides (JP-A-1-118848) have been used. Gazette) has been reported.

[0007]

However, a conventional electrophotographic photosensitive member using a conductive filler as a filler for an intermediate layer has a large environmental dependency such as temperature and humidity.
It has been difficult to prepare a photoreceptor having potential characteristics and image characteristics that are always stable in all environments from low temperature and low humidity to high temperature and high humidity. For example, under a low temperature and low humidity condition that causes an increase in the resistance of the intermediate layer, when the photoreceptor is used repeatedly, charges are accumulated in the intermediate layer, and the residual potential and the light portion potential increase. On the other hand, under high temperature and high humidity, which causes a decrease in the resistance of the intermediate layer, the electrical barrier capability of the intermediate layer was reduced, carrier injection from the support was accelerated, and a decrease in the dark area potential upon repeated use was observed. As a result, in addition to the decrease in image density under high temperature and high humidity, in the case of an electrophotographic printer that performs reversal development, unnecessary black spots (black spots) appear on the image and fogging easily occurs. .

The reason why the characteristics of the photoreceptor change due to a change in environment is considered to be that the dispersibility of the conductive filler is poor. That is, it is considered that a local resistance change occurs due to a decrease in the dispersibility of the conductive filler inside the intermediate layer, and thus the potential characteristics and the image characteristics are easily affected by environmental changes.

An object of the present invention is to provide an electrophotographic photosensitive member having stable potential characteristics and image characteristics under all environments from low temperature and low humidity to high temperature and high humidity, and an electrophotographic apparatus using the electrophotographic photosensitive member. It is to provide.

[0010]

The electrophotographic photoreceptor of the present invention comprises a support, an intermediate layer and a photoconductive layer in this order from the support side, and a powder comprising phosphorus-containing tin oxide fine particles.
It is contained in the intermediate layer.

An electrophotographic apparatus according to the present invention comprises the above electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, and image exposure of the charged electrophotographic photosensitive member to form an electrostatic latent image. It has an image exposing means for forming and a developing means for developing the electrophotographic photosensitive member on which the electrostatic latent image is formed with toner.

The electrophotographic photoreceptor of the present invention has an intermediate layer and a photoconductive layer on a support in order from the support side. The intermediate layer contains, as a filler, a powder composed of phosphorus-containing tin oxide fine particles.

The fine particles of tin oxide containing phosphorus used in the present invention are solid solutions in which phosphorus atoms are incorporated into the crystal lattice of tin oxide. Tin oxide fine particles containing phosphorus are
The electric resistance is lower than that of the tin oxide fine particles not containing phosphorus.

In the present invention, the specific resistance of the powder is 10 to 1
00 Ωcm is preferred. In the present invention, the specific resistance of the powder is measured by a resistance measuring device Loresta AP (Loreest, manufactured by Mitsubishi Yuka).
aAP). The powder to be measured is 500
At the pressure of kg / cm ² , the sample was mounted on the above-mentioned measuring apparatus as a coin-shaped sample.

The content of phosphorus is preferably 0.01 to 30% by weight, more preferably 0.10 to 10% by weight, based on the tin oxide fine particles. The average particle diameter of the tin oxide fine particles containing phosphorus is preferably 0.02 to 0.2 μm, more preferably 0.02 to 0.1 μm. In the present invention, the average particle size of the fine particles is a value measured by a centrifugal sedimentation method.

In general, when the average particle size of the filler is small, dispersion becomes difficult and reagglomeration is likely to occur. However, the filler used in the present invention is excellent in dispersibility. The content of the filler is 1.0 to 90% by weight based on the intermediate layer,
Further, the content is preferably 5.0 to 80% by weight.

The binder resin used in the intermediate layer of the present invention includes, for example, phenol resin, polyurethane, polyamide, polyimide, polyamideimide, polyamic acid, polyvinyl acetal, epoxy resin, acrylic resin,
Melamine resin or polyester is preferred. These resins may be used alone or in combination of two or more. These resins have good adhesiveness to the support, improve the dispersibility of the filler used in the present invention, and have good solvent resistance after film formation. Among the above resins, phenol resins, polyurethanes and polyamic acids are particularly preferred.

In order to improve the dispersibility of the filler, the surface of the filler may be treated with a treating agent such as a coupling agent (such as a silane coupling agent or a titanium coupling agent) or silicone oil. Moreover, you may make the said processing agent contain in the binder of an intermediate | middle layer.

The thickness of the intermediate layer is preferably 0.1 to 30 μm, more preferably 0.5 to 10 μm. The volume resistivity of the intermediate layer 10 ¹³ [Omega] cm or less, more 10 ¹² [Omega] cm or less 10Ω
cm or more is preferred. In the present invention, the volume resistivity is obtained by applying an intermediate layer to be measured on an aluminum plate, further forming a gold thin film on the intermediate layer, and determining the current flowing between both electrodes of the aluminum plate and the gold thin film by pA. It was determined by measuring with a meter.

The intermediate layer may contain a filler made of powder such as zinc oxide or titanium oxide in addition to the powder made of fine particles of tin oxide containing phosphorus. Further, a leveling agent may be added to enhance the surface properties of the intermediate layer.

The photoconductive layer of the present invention may be a single layer or a laminated structure composed of at least a charge generation layer and a charge transport layer.

When the photoconductive layer is a single layer, a charge generating substance,
The charge transport material is contained in the same layer, and photo carriers are generated and moved in the same layer.

When the photoconductive layer has a laminated structure, the order of lamination of the charge generating layer containing the charge generating substance and the charge transporting layer containing the charge transporting substance may be the order of the charge generating layer and the charge transporting layer from the support side. Good or vice versa.

Examples of the charge generating material include azo pigments (eg, monoazo, bisazo, trisazo, etc.), metal and metal-free phthalocyanine pigments, indigo pigments (eg, indigo, thioindigo, etc.), and quinone pigments (eg, anthantrone, Pyrenequinone), perylene pigments (for example, perylene anhydride, perylene imide, etc.), squarium dyes, pyrylium, thiapyrylium salts, and triphenylmethane dyes. In addition, inorganic materials such as selenium, selenium-tellurium, and amorphous silicon can also be used as the material for generating cargo.

The charge transport material includes an electron transport material and a hole transport material. Examples of the electron transporting material include 2,4,7-trinitrofluorenone, 2,4,5,7
-Tetranitrofluorenone, chloranil, tetracyanoquinodimethane and the like. Examples of the hole transport material include polycyclic aromatic compounds (eg, pyrene, anthracene, etc.) and heterocyclic compounds (eg, carbazole, indole, imidazole, oxazole, thiazole,
Oxadiazole, pyrazole, pyrazoline, thiadiazole, triazole and the like, hydrazone-based compounds (for example, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, N, N-diphenylhydrazino-
3-methylidene-9-ethylcarbazole, etc.), styryl compounds (eg, α-phenyl-4′-N, N-diaminostilbene, 5- [4-di-p-tolylamino)
Benzylidene] -5H-dibenzo [a, d] dicycloheptene), benzidine compounds, and triarylamine compounds.

When the photoconductive layer is a single layer, the thickness of the photoconductive layer is preferably 5 to 100 μm, more preferably 10 to 60 μm. The single layer photoconductive layer contains 10 to 70% by weight of each of the charge generating substance and the charge transporting substance, and more preferably 20 to 7% by weight.
It is preferably contained at 0% by weight.

When the photoconductive layer has a laminated structure, the thickness of the charge generation layer is preferably 0.001 to 5 μm, more preferably 0.05 to 2 μm, and the thickness of the charge transport layer is 1 to 40 μm, and more preferably 1 to 40 μm.
0 to 30 μm is preferred. The charge generating layer preferably contains a charge generating substance in an amount of 10 to 100% by weight, more preferably 40 to 100% by weight. The charge transport layer preferably contains a charge transport material in an amount of 20 to 80% by weight, more preferably 30 to 70% by weight.

The electrophotographic photoreceptor of the present invention is obtained by depositing a material used for a photoconductive layer on a support by vacuum evaporation or combining an appropriate binder resin.

As the binder resin of the photoconductive layer, for example, polyvinyl acetal, polycarbonate, polystyrene,
Polyester, polyacetate, polymethacrylate, acrylic resin, cellulosic resin and the like are preferably used.

Depending on the type of material of the photoconductive layer, free carriers may be injected from the intermediate layer into the photoconductive layer,
The charging ability of the photoreceptor is reduced, which greatly affects image characteristics. In such a case, if necessary, a barrier layer (for example, an appropriate resin thin film) having an electric barrier property is provided between the intermediate layer and the photoconductive layer, thereby effectively suppressing the injection of the free carriers. can do. As the barrier layer, for example, polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose,
Water-soluble resins such as ethyl cellulose, polyglutamic acid, casein, and starch, and resins such as polyamide, polyimide, polyamide imide, polyamic acid, melamine resin, epoxy resin, polyurethane, and polyglutamic acid ester can be used. In particular, coating properties, adhesion,
Polyamide is preferred as the barrier layer in terms of solvent resistance, electrical barrier properties, resistance, and the like. As a polyamide,
Low-crystalline or non-crystalline copolymerized nylon which can be applied in a solution state is suitable. The thickness of the barrier layer is preferably from 0.1 to 2 μm.

In the electrophotographic photoreceptor of the present invention, a protective layer may be provided on the photoconductive layer. The protective layer is mainly composed of a resin. Examples of the material constituting the protective layer include, for example, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallylether, polyacetal, nylon, phenolic resin, and acrylic resin. , Silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, butyral resin and the like. The thickness of the protective layer is 0.05 to 15 μm,
10 μm is preferred.

The support is made of a metal or alloy such as aluminum, aluminum alloy, copper, titanium or stainless steel, or a polymer material such as polyethylene terephthalate, polybutylene terephthalate, phenolic resin, polypropylene or polystyrene, or a hard paper. Can be manufactured using the above materials. The shape of the support is cylindrical,
A belt shape or a sheet shape is preferred. When the material constituting the support has a high volume resistance, it is necessary to conduct a conductive treatment. The conductive treatment can be performed by forming a conductive thin film on the support or dispersing a conductive substance in the support.

The electrophotographic photoreceptor of the present invention is widely used not only for electrophotographic copying machines but also for electrophotographic applications such as laser beam printers, CRT printers, LED printers, liquid crystal printers, facsimile machines, and laser plate making. be able to.

The electrophotographic photoreceptor according to the present invention can realize stable potential characteristics and good image formation in all environments from low temperature and low humidity to high temperature and high humidity.

Next, an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention will be described. FIG. 1 shows a schematic configuration of a transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention. In FIG. 1, reference numeral 1 denotes a drum type photosensitive member of the present invention, which is driven to rotate around an axis 1a in a direction indicated by an arrow at a predetermined peripheral speed.
The photosensitive member 1 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by a charging means 2 during the rotation process, and then, in an exposure section 3, a light image exposure L (slit exposure or Laser beam scanning exposure). As a result, an electrostatic latent image corresponding to the exposure image is sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then developed with toner by developing means 4, and the developed toner image is transferred to transfer means 5.
The recording material P fed from the paper supply unit (not shown) between the photosensitive member 1 and the transfer unit 5 in synchronization with the rotation of the photosensitive member 1
Are sequentially transferred to the surface of The recording material P to which the image has been transferred is separated from the surface of the photoreceptor, introduced into the image fixing means 8, subjected to image fixing, and printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned by removing the untransferred toner by the cleaning means 6, and
The charge is removed by the pre-exposure means 7 and is repeatedly used for image formation. As the uniform charging means 2 for the photoreceptor 1, a corona charging device is generally widely used. Also, the corona transfer means is generally widely used for the transfer device 5. As an electrophotographic apparatus, a plurality of components such as the above-described photoreceptor, developing means, and cleaning means are integrally connected as an apparatus unit, and this unit is configured to be detachable from the apparatus body. May be. For example, the photoreceptor 1 and the cleaning means 6 may be integrated into one apparatus unit, and may be configured to be detachable using a guide means such as a rail of the apparatus body. At this time, the above-described device unit may be provided with a charging unit and / or a developing unit. In the case where the electrophotographic apparatus is used as a copier or a printer, the light image exposure L uses reflected light or transmitted light from the original, or reads the original and converts it into a signal.
This is performed by driving a light emitting diode array or a liquid crystal shutter array.

[0036]

【Example】

Example 1 140 parts by weight of a filler (powder specific resistance 25 Ωcm) composed of phosphorus-containing tin oxide fine particles and a resol-type phenol resin (Priofen J-325, trade name, manufactured by Dainippon Ink and Chemicals, Inc., solid content 70) %) 70 parts by weight and 2
A solution consisting of 100 parts by weight of -methoxy-1-propanol was dispersed in a ball mill for about 30 hours. The average particle size of the filler contained in this dispersion was measured using a particle size analyzer (trade name CA
(PA-700, manufactured by Horiba Seisakusho) by centrifugal sedimentation and found to be 0.08 μm. The phosphorus content in the fine particles was 1% by weight.

The dispersion thus prepared was applied to an outer diameter of 30.
mm, a 360 mm long aluminum cylinder (surface roughness Rmax 5 μm)
The mixture was cured by heating at 40 ° C. for 30 minutes to form an intermediate layer having a thickness of 15 μm. The surface roughness Rmax measured at this time was 0.4 μm. The roughness Rmax is JISB
0601.

Next, a copolymer nylon (trade name: Amiran C)
M8000 (manufactured by Toray Industries, Inc.) 10 parts by weight was dissolved in a mixture of 60 parts by weight of methanol and 40 parts by weight of butanol, dip-coated on the intermediate layer, and dried by heating at 90 ° C. for 10 minutes to obtain a thickness. A 0.5 μm barrier layer was formed.

Next, 4 parts by weight of a titanyloxyphthalocyanine pigment, 2 parts by weight of polyvinyl butyral (trade name BX-1, manufactured by Sekisui Chemical Co., Ltd.), and cyclohexanone 34
After dispersing the solution consisting of parts by weight with a sand mill for 8 hours,
60 parts by weight of tetrahydrofuran was added to prepare a dispersion for the charge generation layer. This dispersion was applied onto the above barrier layer by dip coating, and dried by heating at 80 ° C. for 10 minutes to form a charge generation layer. The thickness of the charge generation layer was about 0.2 μm.

Next, 50 parts by weight of a triarylamine compound represented by the following structural formula was added.

[0041]

[Outside 1]

Polycarbonate (trade name Iupilon Z-)
200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 50 parts by weight of monochlorobenzene were dissolved in 400 parts by weight, and this was applied by dip coating on the charge generation layer, and dried by heating at 120 ° C. for 1 hour to form a charge having a thickness of 20 μm. A transport layer was formed.

The electrophotographic photoreceptor of the present invention thus prepared is mounted on a regular development type electrophotographic copying machine.
The charging-exposure-transfer-cleaning process was repeated in a 0.8 second cycle. The electrophotographic characteristics of this photoreceptor were evaluated in a low-temperature and low-humidity environment (15 ° C., 15% RH). As a result, as shown in Table 1, in this photoreceptor, a large difference could be formed between the dark portion potential (V _D ) and the bright portion potential (V _L ), and sufficient contrast could be obtained. . Further, when an image was continuously output on 10,000 sheets of recording paper, the dark portion potential and the light portion potential hardly changed, and an image with very stable image quality was obtained.

[0044]

[Table 1]

Example 2 An aluminum cylinder having an outer diameter of 30 mm and a length of 260 m
The electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 1 except that m was used. The thus prepared electrophotographic photosensitive member was mounted on a reversal developing type printer, and a charging-exposure-transfer-cleaning process was repeated in a cycle of 6 seconds. The electrophotographic characteristics of this photoreceptor were evaluated in a high-temperature and high-humidity environment (30 ° C., 85% RH). As a result, as shown in Table 2, in this photoreceptor, a large difference could be formed between the dark portion potential (V _D ) and the bright portion potential (V _L ), and sufficient contrast could be obtained. . Further, when an image was continuously output on 5000 sheets of recording paper, neither the dark part potential nor the light part potential changed.
In addition, there was no black spot-like defect or fog, and an image with very stable image quality was obtained.

[0046]

[Table 2]

Example 3 The filler was changed to a powder of tin oxide fine particles having a phosphorus content of 5% by weight (powder specific resistance: 12 Ωcm), and the binder resin of the intermediate layer was changed to polyurethane (Nipporan 2304 (trade name)). An electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 1 except that the product was replaced by Nippon Polyurethane Co., Ltd.). At this time, the average particle size of the filler contained in the dispersion liquid for the intermediate layer was measured in the same manner as in Example 1, and as a result,
It was 0.10 μm.

The thus prepared electrophotographic photosensitive member was mounted on an electrophotographic copying machine of a regular developing system, and a charging-exposure-transfer-cleaning process was repeated at a cycle of 0.8 seconds. Low temperature and low humidity (15 ° C,
The electrophotographic properties were evaluated in an environment of 15% RH).
As a result, as shown in Table 3, with this photoreceptor, a large difference could be formed between the dark portion potential (V _D ) and the bright portion potential (V _L ), and sufficient contrast could be obtained. . Further, when images were continuously formed on 10,000 sheets of recording paper, there was no change in potential and very stable image characteristics were exhibited.

[0049]

[Table 3]

Example 4 The filler was changed to a powder (fine powder resistivity: 10 Ωcm) composed of tin oxide fine particles having a phosphorus content of 10% by weight in the fine particles, and the binder resin of the intermediate layer was changed to a polyamic acid having the following structure. Instead, an electrophotographic photosensitive member of the present invention was prepared in the same manner as in Example 1.

[0051]

[Outside 2] At this time, the average particle diameter of the filler contained in the dispersion liquid for the intermediate layer was measured by the same method as in Example 1, and as a result, was 0.09.
μm.

The thus prepared electrophotographic photosensitive member was mounted on an electrophotographic copying machine of a regular development system, and a charging-exposure-transfer-cleaning process was repeated at a cycle of 0.8 seconds. Low temperature and low humidity (15 ° C,
The electrophotographic properties were evaluated in an environment of 15% RH).
As a result, as shown in Table 4, with this photoreceptor, a large difference could be formed between the dark part potential (V _D ) and the light part potential (V _L ), and sufficient contrast could be obtained. . Further, when images were continuously formed on 10,000 sheets of recording paper, there was no change in potential, and extremely stable image characteristics were exhibited.

[0053]

[Table 4]

Comparative Examples 1 and 2 Comparative Example 1 was performed in the same manner as in Example 1 except that the intermediate layer of Example 1 was replaced with an intermediate layer formed using the following coating solution.
And 2 were prepared. Each of the electrophotographic photoreceptors thus prepared was mounted on an electrophotographic copying machine of a regular development system, and a charging-exposure-transfer-cleaning process was repeated at a cycle of 0.8 seconds. Low temperature and low humidity (15 ° C, 15% RH) for these photoconductors
The electrophotographic properties were evaluated under the following environment. As a result, Table 5
As shown in (1), in each case, a large difference could be formed between the dark portion potential (V _D ) and the bright portion potential (V _L ) in the initial stage, and sufficient contrast was obtained. However, when images were continuously formed on 10,000 sheets of recording paper, a decrease in the dark area potential and an increase in the light area potential were observed for all the electrophotographic photosensitive members.

Formulation for Comparative Example 1 100 parts by weight of fine powder of titanium oxide having an antimony-containing tin oxide coating layer (trade name: ECTT-
1. Titanium Kogyo Co., Ltd.) 70 parts by weight of resole type phenolic resin (trade name Plyofen J-325) 80 parts by weight of methyl cellosolve

Powder of antimony-containing tin oxide fine particles in the formulation of Comparative Example 2
0 parts by weight (trade name T-1, manufactured by Mitsubishi Materials Corporation) 70% by weight of polyester polyurethane (Nipporan 2304) 80 parts by weight of 2-methoxy-1-propanol

[0057]

[Table 5]

Examples 5 and 6 An aluminum cylinder having an outer diameter of 30 mm and a length of 260 m
The electrophotographic photoreceptors of Examples 5 and 6 were prepared in the same manner as in Examples 3 and 4, except that m was used. These electrophotographic photoreceptors of the present invention were mounted on a reversal-developed electrophotographic printer, and a charging-exposure-transfer-cleaning process was repeated at a cycle of 6 seconds. The electrophotographic characteristics of these photoreceptors were evaluated in a high-temperature and high-humidity environment (30 ° C., 85% RH). As a result, as shown in Table 6, in these photoconductors, a large difference can be formed between the dark portion potential (V _D ) and the bright portion potential (V _L ), and sufficient contrast can be obtained. Was. Further, when images were successively output on 5000 sheets of recording paper, almost no change in the dark portion potential and the bright portion potential was observed for any of the electrophotographic photoreceptors, and no unnecessary black spots were generated or fogged. An image with very stable image quality was obtained.

[0059]

[Table 6]

Comparative Examples 3 and 4 An aluminum cylinder was set to have an outer diameter of 30 mm and a length of 260 m.
The electrophotographic photoreceptors of Comparative Examples 3 and 4 were prepared in the same manner as in Comparative Examples 1 and 2, except that m was used. These electrophotographic photosensitive members were mounted on a reversal-developed electrophotographic printer, and a charging-exposure-transfer-cleaning process was repeated at a cycle of 6 seconds. The electrophotographic characteristics of these photoreceptors were evaluated in a high-temperature and high-humidity environment (30 ° C., 85% RH). As a result, as shown in Table 7,
In these photoconductors, a large difference was initially formed between the dark portion potential (V _D ) and the light portion potential (V _L ), and sufficient contrast was obtained. However, when an image was continuously displayed on 5000 sheets of recording paper, a decrease in the dark area potential was observed, and unnecessary black spots were noticeably generated on the image from the beginning.

[0061]

[Table 7]

Example 7 The same intermediate layer dispersion as in Example 1 was applied on an aluminum plate having a length of 250 mm, a width of 150 mm and a thickness of 0.5 mm with a Meyer bar, and dried and cured at 140 ° C. for 30 minutes. An intermediate layer of 5 μm was formed.

Next, 5 parts by weight of a bisazo pigment having the following structural formula

[0064]

[Outside 3] 90 parts by weight of tetrahydrofuran was added and dispersed by a sand mill for 20 hours. Further, a solution prepared by dissolving 2.5 parts by weight of butyral resin (trade name: BLS, manufactured by Sekisui Chemical Co., Ltd.) in 20 parts by weight of tetrahydrofuran was added to the liquid, and the mixture was further dispersed for 2 hours. Cyclohexanone 10
0 parts by weight and 100 parts by weight of tetrahydrofuran were added and diluted, and the mixture was applied on the above-mentioned intermediate layer with a Meyer bar so as to have a thickness of 0.2 μm to form a charge generation layer.

Next, a styryl compound 50 of the following structural formula
Parts by weight

[0066]

[Outside 4] 50 parts by weight of polycarbonate (trade name: Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) is dissolved in 400 parts by weight of monochlorobenzene, and this is dip-coated on the charge generation layer and heated at 120 ° C. for 1 hour. Dry to a film thickness of 2
An electrophotographic photoreceptor of the present invention was formed by forming a 0 μm charge transport layer.

The electrophotographic photoreceptor prepared in this way was tested with an electrostatic copying machine tester (trade name Model SP).
-428, manufactured by Kawaguchi Electric Co., Ltd.). The charging characteristics were evaluated by negatively charging the electrophotographic photoreceptor with a -5 kV corona discharge, leaving it in a dark place for 1 second, exposing it to light with an illuminance of 10 lux using a halogen lamp, and measuring the initial surface potential at this time. (V ₀ ), the exposure amount (E _1/2 ) and the residual potential (V _r ) required to attenuate the surface potential after being left in a dark place by half. Table 8 shows the evaluation results.

Examples 8 and 9 The same intermediate layers as those in Examples 3 and 4 were used.
The electrophotographic photoreceptors of Examples 8 and 9 were prepared in the same manner as in Example 7 except that a barrier layer was provided on the intermediate layer, and the charging characteristics of each electrophotographic photoreceptor were obtained in the same manner as in Example 7. Was evaluated. The barrier layer had a thickness of 1 μm and was formed using the same barrier layer dispersion as in Example 1.

Table 8 shows the results of the evaluation.

[0070]

[Table 8]

Comparative Examples 5 and 6 The electrophotographic photosensitive members of Comparative Examples 5 and 6 were prepared in the same manner as in Example 8 except that the intermediate layer was replaced with the same intermediate layer as in Comparative Examples 1 and 2. The charging characteristics of each electrophotographic photosensitive member were evaluated in the same manner as in Example 7. Table 9 shows the evaluation results.
It was shown to. The electrophotographic sensitivity of these photoconductors was clearly lower than those of the photoconductors prepared in Examples 7 to 9.

[0072]

[Table 9]

[0073]

According to the electrophotographic photoreceptor of the present invention,
Stable potential characteristics and good image formation can be realized in all environments from low temperature and low humidity to high temperature and high humidity.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Charging means 3 Exposure part 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuma Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-2-275468 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 5/00-5/16

Claims (9)

(57) [Claims] 1. An electrophotographic apparatus comprising: a support; an intermediate layer and a photoconductive layer in this order from the support side; and the intermediate layer contains a powder of fine particles of tin oxide containing phosphorus. Photoconductor. 2. The fine particles having an average particle size of 0.02 to 0.2.
2. The electrophotographic photosensitive member according to claim 1, which has a thickness of 2 μm. 3. The method according to claim 1, wherein the average particle size is 0.02 to 0.1 μm.
The electrophotographic photosensitive member according to claim 2, wherein 4. The electrophotographic photosensitive member according to claim 1, wherein the content of the phosphorus is 0.01 to 30% by weight based on the fine particles. 5. The electrophotographic photoconductor according to claim 4, wherein the content is 0.10 to 10% by weight. 6. The binder resin of the intermediate layer is selected from the group consisting of phenolic resin, polyurethane, polyamide, polyimide, polyamideimide, polyamic acid, polyvinyl acetal, epoxy resin, acrylic resin, melamine resin and polyester. The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor is used. 7. A phenol resin as the binder resin,
7. The electrophotographic photoreceptor according to claim 6, wherein one selected from a polyurethane and a polyamic acid is used. 8. The electrophotographic photosensitive member according to claim 1, further comprising a barrier layer between said intermediate layer and said photoconductive layer. 9. An electrophotographic photosensitive member according to claim 1, charging means for charging said electrophotographic photosensitive member, and image exposure for forming an electrostatic latent image by performing image exposure on said charged electrophotographic photosensitive member. And an developing device for developing the electrophotographic photosensitive member on which the electrostatic latent image is formed with toner.