JP3118129B2 - Electrophotographic photoreceptor, apparatus unit using the electrophotographic photoreceptor, and electrophotographic apparatus - 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 , an apparatus unit using the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic photoreceptor basically comprises 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) A resin thin film containing no conductive filler. (Ii) A resin thin film containing a conductive filler. (Iii) The thin film of (i) is laminated on the thin film of (ii).

[0004] The thin film (i) does not contain a conductive filler and therefore has a high film resistance, and must be used in 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 in all environments from low temperature and low humidity to high temperature and high humidity , and to use the electrophotographic photosensitive member. it is to provide a gastric device unit and an electrophotographic apparatus.

[0010]

The electrophotographic photoreceptor of the present invention comprises a support, an intermediate layer and a photosensitive layer in this order from the support.
An electrophotographic photosensitive member comprising, in the intermediate layer, oxide scan
And barium sulfate fine particles having a coating layer having a coverage of 10 to 80% by weight .

[0011] The apparatus unit of the present invention comprises :
Electrophotographic photoreceptor and charging means according to any one of the above, and development
Means and cleaning means.
And an electrophotographic device book
It is detachable from the body. An electrophotographic apparatus according to the present invention includes the electrophotographic photosensitive member according to any one of claims 1 to 9 , a charging unit, an exposing unit, and a developing unit.

The electrophotographic photosensitive member of the present invention has an intermediate layer and a photosensitive layer on a support in order from the support side. The intermediate layer contains, as a filler, a powder composed of barium sulfate fine particles having a conductive coating layer.

The barium sulfate fine particles have very excellent dispersibility. Further, since the refractive index of the barium sulfate fine particles is substantially equal to the refractive index of the binder resin, the light transmittance of the intermediate layer does not decrease.

In the present invention, a barium sulfate fine particle is provided with a conductive coating layer so as to have an appropriate specific resistance as a filler. As the coating layer, a coating layer formed of tin oxide is used. The specific resistance of the barium sulfate powder having the coating layer is preferably 0.1 to 1000 Ωcm, more preferably 1 to 1000 Ωcm.

In the present invention, the powder specific resistance is measured by a resistance measuring device Loresta AP (Loresta Ap) manufactured by Mitsubishi Yuka.
It measured using. The powder to be measured is 500 kg / c
The sample was mounted on the measuring device as a coin-shaped sample with a pressure of m ² .

The coverage of the coating layer 10 to 80 wt% der
And 30 to 60% by weight is preferred. The coverage of the coating layer is the ratio of the total weight of the coating layer used in the powder to the weight of the powder comprising the fine particles having the coating layer.
The average particle size of the barium sulfate fine particles having the coating layer is 0.0
It is preferably from 5 to 1.0 μm, more preferably from 0.07 to 0.7 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 tends 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 coating layer may contain fluorine or antimony as needed. By containing fluorine or antimony, the specific resistance of the coating layer can be reduced. The coating layer of tin oxide containing fluorine or antimony is a solid solution in which fluorine atoms or antimony atoms are incorporated in the crystal lattice of tin oxide.
The content of fluorine or antimony is preferably 0.01 to 30% by weight, more preferably 0.1 to 10% by weight, based on the coating layer.

The specific resistance of the coating layer can also be reduced by deficient oxygen of tin oxide by a reduction method.

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.

The intermediate layer can be formed by, for example, dipping or applying a solvent using a Meyer bar or the like.

In order to improve the dispersibility of the filler, the filler surface may be treated with a coupling agent (such as a silane coupling agent or a titanium coupling agent) or a treating agent such as 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 setting a current value flowing between both electrodes of the aluminum plate and the gold thin film to _p. It was determined by measuring with an 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 barium sulfate fine particles having a coating layer. Further, a leveling agent may be added to enhance the surface properties of the intermediate layer.

The photosensitive layer of the present invention may be a single layer, or may have a laminated structure comprising at least a charge generation layer and a charge transport layer.

When the photosensitive layer is a single layer, a charge generating substance and a charge transporting substance are contained in the same layer, and photo carriers are generated and moved in the same layer.

When the photosensitive layer has a laminated structure, the charge generating layer containing the charge generating substance and the charge transporting layer containing the charge transporting substance may be laminated in the order of the charge generating layer and the charge transporting layer from the support side. And vice versa.

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

As the charge transport material, there are an electron transport material and a hole transport material. Examples of the electron transporting substance and the hole transporting substance 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.), heterocyclic compounds (eg, carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole, triazole, etc.), Hydrazone-based compounds (for example, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole and the like), styryl-based compounds (for example, α-phenyl-
4'-N, N-diaminostilbene, 5- [4- (di-
p-tolylamino) benzylidene] -5H-dibenzo [a, d] dicycloheptene, a benzidine compound, a triarylamine compound, and the like.

When the photosensitive layer is a single layer, the thickness of the photosensitive layer is 5 to 5.
It is preferably 100 μm, more preferably 10 to 60 μm. In the single photosensitive layer, the charge generating substance and the charge transporting substance are each contained in an amount of 10 to 70% by weight, more preferably 20 to 70% by weight.
It is preferred to contain.

When the photosensitive 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 10 to 40 μm.
-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 contains 2 charge transport materials.
The content is preferably 0 to 80% by weight, more preferably 30 to 70% by weight.

The electrophotographic photoreceptor of the present invention can be obtained by forming a film on a support by combining a material used for a photosensitive layer with a vacuum deposition or an appropriate binder resin.

As the binder resin for the photosensitive layer, for example, polyvinyl acetal, polycarbonate, polystyrene, polyester, polyacetate, polymethacrylate, acrylic resin, cellulose resin and the like are preferably used.

Depending on the kind of the material of the photosensitive layer, free carriers may be injected from the intermediate layer into the photosensitive layer, which lowers the charging ability of the photosensitive member and greatly affects image characteristics.
In such a case, if necessary, a barrier layer (for example, a suitable resin thin film) having an electric barrier property is provided between the intermediate layer and the photosensitive layer to effectively suppress the injection of the free carrier. be able to. As the barrier layer, for example, polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methylcellulose, ethylcellulose, polyglutamic acid, casein, water-soluble resin such as starch, polyamide, polyimide, polyamideimide, polyamic acid, melamine resin, epoxy resin, Resins such as polyurethane and polyglutamic acid ester can be used. In particular, polyamide is preferable as the barrier layer in terms of coating properties, adhesion, solvent resistance, electrical barrier properties, resistance, and the like. As the polyamide, a low-crystalline or non-crystalline copolymer nylon which can be applied in a solution state is suitable. The thickness of the barrier layer is
0.1 to 2 μm is preferred.

In the electrophotographic photosensitive member of the present invention, a protective layer may be provided on the photosensitive layer. The protective layer is mainly composed of a resin. As a material constituting the protective layer, for example, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamide imide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, acrylic resin, Examples include silicone resin, epoxy resin, urea resin, allyl resin, alkyd resin, and butyral resin. 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, stainless steel, or a polymer material such as polyethylene terephthalate, polybutylene terephthalate, phenolic resin, polypropylene, polystyrene, or hard paper. It can be manufactured using 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 the figure, reference numeral 1 denotes a drum type photoconductor of the present invention,
It is driven to rotate around the shaft 1a in the direction of the 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 a developing unit 4, and the developed toner image is transferred by a transfer unit 5 between a photosensitive unit 1 and a transfer unit 5 from a paper supply unit (not shown) in synchronization with the rotation of the photosensitive unit 1. The recording material P is sequentially transferred onto the surface of the taken and fed recording material P. Recording material P after image transfer
Is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing to be printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning means 6, subjected to a charge removal treatment by the pre-exposure means 7, and used repeatedly 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. When the electrophotographic apparatus is used as a copying machine 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, and scans the laser beam according to the signal. This is performed by driving a light emitting diode array or a liquid crystal shutter array.

[0040]

【Example】

Example 1 Powder composed of barium sulfate fine particles having a coating layer of tin oxide (coverage 50% by weight, powder specific resistance 700 Ωcm) 1
20 parts by weight and a resole type phenol resin (Plyofen J-325, manufactured by Dainippon Ink and Chemicals, solid content 7
(0%) A solution consisting of 70 parts by weight and 100 parts by weight of 2-methoxy-1-propanol was dispersed in a ball mill for about 20 hours. The average particle size of the filler contained in this dispersion was 0.22 μm.

The dispersion prepared in this manner was treated with an outer diameter of 30.
mm, an aluminum cylinder having a length of 360 mm (surface roughness R _max 5 μm) was applied by an immersion method.
By heating and curing at 0 ° C for 30 minutes, the thickness is 17 μm
Was formed. Surface roughness R _max of the intermediate layer at this time
Was 0.5 μm. Note that the roughness R _max
Is based on JIS B0601.

Next, a copolymerized nylon resin (Amilan CM)
(8000, manufactured by Toray) A solution prepared by dissolving 10 parts by weight of a mixture of 60 parts by weight of methanol and 40 parts by weight of butanol was dip-coated on the intermediate layer, and dried by heating at 90 ° C. for 10 minutes to obtain a 0.5 μm thick layer Was formed.

Next, a solution consisting of 4 parts by weight of oxytitanium phthalocyanine pigment, 2 parts by weight of polyvinyl butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 34 parts by weight of cyclohexanone was dispersed in a sand mill for 8 hours, and then 60 parts by weight of tetrahydrofuran 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 0.2 μm.

Next, 50 parts by weight of a triarylamine compound represented by the following structure:

[0045]

[Outside 1] A solution prepared by dissolving 50 parts by weight of a polycarbonate resin (Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 400 parts by weight of monochlorobenzene was applied onto the charge generating layer by dip coating, and dried by heating at 120 ° C. for 1 hour to a thickness of 20 μm. Was formed.

The electrophotographic photoreceptor of the present invention thus prepared is mounted on a normal development electrophotographic copying machine.
The charging-exposure-development-transfer-cleaning process was repeated in a 0.8 second cycle. For this photoreceptor, low temperature and low humidity (15 ° C., 15% RH) and high temperature and high humidity (30
(C, 85% RH).
As a result, as shown in Table 1, this photoreceptor can form a large difference between the dark portion potential (V _D ) and the bright portion potential (V _L ) at both low temperature and low humidity and high temperature and high humidity. As a result, sufficient contrast could be obtained. Further, when images were continuously printed on 10,000 sheets of recording paper, the dark potential and the bright potential hardly changed in any environment, and an image of extremely excellent image quality was stably obtained.

[0047]

[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 obtained electrophotographic photosensitive member was mounted on a reversal-developed electrophotographic printer, and subjected to a charge-exposure-development-transfer-cleaning process of 6
Repeated on a second cycle. Low temperature and low humidity (15 ° C., 15% RH) and high temperature and high humidity (30 ° C., 85
% RH), the electrophotographic properties were evaluated. As a result, as shown in Table 2, the photosensitive member has a dark portion potential (V _D ) and a bright portion potential (V _D ) even at a low temperature and a low humidity and a high temperature and a high humidity.
_L ) and a large difference could be formed, and sufficient contrast could be obtained. In addition, 50
When an image was displayed on 00 sheets of recording paper, the dark potential and the bright potential hardly changed in any environment.
In addition, an image of extremely excellent image quality without unnecessary black spot images and fog was stably obtained.

[0049]

[Table 2]

Examples 3 to 6 The same procedure as in Example 1 was carried out except that the intermediate layer of Example 1 was replaced with an intermediate layer formed by using the following coating solution.
Each of the electrophotographic photosensitive members of Nos. 1 to 6 was prepared. Example 3
The average particle size of the filler contained in the coating liquid for the intermediate layer of No. 1 is 0.1.
It was 27 μm. The average particle size of the filler contained in the coating liquid for an intermediate layer of Example 4 was 0.25 μm.

Each of the electrophotographic photosensitive members thus prepared was evaluated in the same manner as in Example 1. As a result, as shown in Table 3, the photoreceptors had a dark potential (V _D ) and a light potential (V _D ) at both low and low humidity and high and high humidity.
_L ) and a large difference could be formed, and sufficient contrast could be obtained. In addition, 100
When an image was displayed on 00 sheets of recording paper, the dark potential and the bright potential hardly changed in any environment.
Images of very good quality were also obtained stably.

Powder composed of barium sulfate fine particles having a coating solution and a fluorine-containing tin oxide coating layer of Example 3 (coating rate: 50% by weight, fluorine content in the coating layer: 9% by weight, powder specific resistance: 40 Ωcm) 150
Parts by weight-70 parts by weight of the same resol-type phenol resin as in Example 1-100 parts by weight of 2-methoxy-1-propanol

[0053] Powder consisting of barium sulfate fine particles having a tin oxide coating layer coating liquid, antimony-containing Example 4 (coating ratio of 50 wt%, antimony content of 9 wt% in the coating layer, powder specific resistance 30Ωc
m) 100 parts by weight-70 parts by weight of the same resol-type phenol resin as in Example 1-80 parts by weight of 2-methoxy-1-propanol

The coating liquid of Example 5 and the powder comprising the same barium sulfate fine particles as in Example 1.
120 parts by weight ・ Polyester polyurethane (Nipporan 2304, manufactured by Nippon Polyurethane) 70 parts by weight ・ 2-methoxy-1-propanol 100 parts by weight

The coating liquid of Example 6 and the powder comprising the same barium sulfate fine particles as in Example 3.
100 parts by weight ・ Polyamic acid resin having the following structural formula (weight average molecular weight: 85
00) 50 parts by weight

[0056]

[Outside 2] ・ N, N-dimethylacetamide 170 parts by weight

[0057]

[Table 3]

Comparative Examples 1 and 2 Comparative Examples 1 and 2 were the same as Example 1 except that the intermediate layer of Example 1 was replaced with an intermediate layer formed by using the following coating solution.
And 2 were prepared. The average particle size of the filler contained in the coating liquid for an intermediate layer of Comparative Example 1 was 0.25 μm. The average particle size of the filler contained in the coating liquid for an intermediate layer of Comparative Example 2 was 0.20 μm.

Each of the electrophotographic photosensitive members thus produced was evaluated in the same manner as in Example 1. As a result, as shown in Table 4, in any of the photoconductors, a large difference can be initially formed between the dark portion potential (V _D ) and the bright portion potential (V _L ), and a sufficient contrast can be obtained. However, when images were continuously formed on 10,000 sheets of recording paper, a drop in the dark area potential and an increase in the light area potential were observed in any of the electrophotographic photosensitive members in a low-temperature and low-humidity environment.

Powder composed of fine particles of titanium oxide having a coating layer of tin oxide containing antimony in Comparative Example 1 (ECTT-1, manufactured by Titanium Industry Co., Ltd.)
150 parts by weight-75 parts by weight of the same resole type phenol resin as in Example 1-60 parts by weight of methyl cellosolve-15 parts by weight of methanol

The powder comprising the coating liquid of antimony-containing tin oxide fine particles of Comparative Example 2 (T-
1, manufactured by Mitsubishi Materials Corporation) 100 parts by weight-70% by weight of the same polyester polyurethane as in Example 5-80 parts by weight of 2-methoxy-1-propanol

[0062]

[Table 4]

Examples 7 to 10 An aluminum cylinder having an outer diameter of 30 mm and a length of 260 m
Others are the same as in Examples 3 to 6, instead of m.
Example 7 (using the intermediate layer of Example 3), Example 8 (using the intermediate layer of Example 4), Example 9 (using the intermediate layer of Example 5), and Example 10 (using the intermediate layer of Example 6). (Using an intermediate layer).

Each of the electrophotographic photosensitive members thus produced was evaluated in the same manner as in Example 2. As a result, as shown in Table 5, these photoconductors can form a large difference between the dark portion potential (V _D ) and the bright portion potential (V _L ) even at low temperature, low humidity and high temperature and high humidity. High contrast was obtained. Furthermore, when images were continuously output on 5000 sheets of recording paper, both the dark potential and the bright potential hardly changed in any environment, and extremely excellent image quality free of unnecessary black spot images and fog Was obtained stably.

[0065]

[Table 5]

Comparative Examples 3 and 4 An aluminum cylinder having an outer diameter of 30 mm and a length of 260 m
Comparative Example 3 (using the intermediate layer of Comparative Example 1) and Comparative Example 4 in the same manner as Comparative Examples 1 and 2 in place of m
An electrophotographic photosensitive member (using the intermediate layer of Comparative Example 2) was prepared.

Each of the electrophotographic photosensitive members thus prepared was evaluated in the same manner as in Example 2. As a result, as shown in Table 6, each of the photoconductors initially had a dark portion potential (V
_D ) and a bright portion potential (V _L ), a large difference could be formed, and sufficient contrast could be obtained.
When an image was continuously formed on 5000 sheets of recording paper, a drop in the dark area potential was observed in any of the electrophotographic photosensitive members under a high temperature and high humidity environment. Unnecessary black spots were found on the recording paper from the beginning in an environment of high temperature and high humidity.

[0068]

[Table 6]

Example 11 The intermediate layer dispersion used in Example 1 was applied on the same aluminum cylinder as in Example 1 by a dipping method.
By drying and curing at 40 ° C. for 30 minutes, an intermediate layer having a thickness of 5 μm was formed.

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

[0071]

[Outside 3] 90 parts by weight of tetrahydrofuran was added and dispersed by a sand mill for 20 hours. A solution of 2.5 parts by weight of butyral resin (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. This dispersion was diluted by adding 100 parts by weight of cyclohexanone and 100 parts by weight of tetrahydrofuran, and applied onto the 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,

[0073]

[Outside 4] A solution prepared by dissolving 50 parts by weight of a polycarbonate resin (Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 400 parts by weight of monochlorobenzene was applied onto the charge generating layer by dip coating, and dried by heating at 120 ° C. for 1 hour to a thickness of 20 μm. To form an electrophotographic photoreceptor of the present invention.

The electrophotographic photosensitive member thus prepared was evaluated in the same manner as in Example 1. As a result, these photoreceptors form a large difference between the dark part potential (V _D ) and the light part potential (V _L ) at both low temperature and low humidity and high temperature and high humidity as shown in Table 7. I was able to get enough contrast. In addition, 1
When an image was formed on 0000 sheets of recording paper, both the dark portion potential and the bright portion potential hardly changed in any environment, and an image with extremely excellent image quality was stably obtained.

[0075]

[Table 7]

Example 12 As the dispersion for the intermediate layer, the one used in Example 3 was used.
Otherwise, the procedure of Example 11 was followed to prepare an electrophotographic photoreceptor of the present invention.

The electrophotographic photosensitive member thus prepared was evaluated in the same manner as in Example 1. As a result, as shown in Table 8, this photoreceptor can form a large difference between the dark portion potential (V _D ) and the bright portion potential (V _L ) even at low and low humidity and at high temperature and high humidity. Sufficient contrast was obtained. Further, when an image was continuously output on 10,000 sheets of recording paper, the dark potential and the bright potential hardly changed in any environment, and an image of extremely excellent image quality was stably obtained.

[0078]

[Table 8]

[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

Continuation of the front page (72) Inventor Akira Shimada Within Canon Inc. 3- 30-2 Shimomaruko, Ota-ku, Tokyo (72) Inventor Kazuma Sato 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc. (56) References JP-A-61-222653 (JP, A) JP-A-58-25363 (JP, A) JP-A-3-45962 (JP, A) JP-A-61-110153 (JP, A) JP-A-61-36755 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/00-5/16

Claims (11)

(57) [Claims] 1. An electrophotographic photoreceptor having a support, an intermediate layer and a photosensitive layer in order from the support, wherein the intermediate layer is formed of tin oxide and has a coverage of 10 to 80% by weight.
% . An electrophotographic photoreceptor containing barium sulfate fine particles having a coating layer having a percentage of 2. The electrophotographic photoreceptor of claim 1, wherein the coating ratio is 30 to 60 wt%. To wherein the coating layer, according to claim 1 or 2 electrophotographic photosensitive member according to contain fluorine or antimony. 4. The electrophotographic photosensitive member according to claim 3 , wherein the content of the fluorine or the antimony is 0.01 to 30% by weight based on the coating layer. 5. The electrophotographic photoreceptor according to claim 4 , wherein said content is 0.1 to 10% by weight. 6. The method according to claim 6, wherein said tin oxide lacks oxygen by a reduction method.
3. The electrophotographic photoreceptor according to claim 1 , wherein the electrophotographic photoreceptor is damaged . 7. A binder resin for the intermediate layer, which is a phenol resin, a polyurethane, a polyamide, a polyimide, a polyamideimide, a polyamic acid, a polyvinyl acetal,
Epoxy resin, according to claim 1 乃 to use one selected from acrylic resins, the group consisting of melamine resin 及 beauty polyester
7. The electrophotographic photosensitive member according to any one of 6 to 6 . 8. A phenol resin as the binder resin,
The electrophotographic photosensitive member according to claim 7, wherein a member selected from the group consisting of polyurethane and polyamic acid is used. 9. An electrophotographic photosensitive member according to any one of claims 1 to 8 having a barrier layer between the intermediate layer and the photosensitive layer. 10. The power supply according to claim 1, wherein
Photographic photoconductor and charging means, developing means and cleaning
At least one means selected from the means
And is removable from the main body of the electrophotographic apparatus.
And a device unit characterized by: 11. An electrophotographic photosensitive member according to any one of claims 1 to 9, a charging means, an electrophotographic apparatus, comprising an exposure means and developing means.