JPH06222600A - Electrophotogrpahic sensitive body and electrophotographic apparatus using the same - Google Patents

Abstract

PURPOSE:To obtain potential and image characteristics stable under all the environment from a low temperature and low humidity to a high temperature and high humidity by incorporating a powder comprising fine tin oxide particles containing phosphorus in an interlayer. CONSTITUTION:The electrphotographic sensitive body comprises a substrate and the interlayer and a photosensitive layer in this order from the substrate, and contains the powder comprising fine tin oxide particles containing phosphorus in an amount of 0.01-30 weight % and having an average particle diameter 0.02-0.2mum, and this powder is a solid solution obtained by enclosing the phosphorus atoms in the crystal lattices of the tin oxide. The fine tin oxide particles containing the phosphorus is lower in electric conductivity than the one containing no phosphorus. It is preferred that the powder has a specific resistivity of 10-100OMEGAcm and the binder resin used for the interlayer is a phenol resin, polyurethane, polyamide, and the like.

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 this electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member basically comprises a support,
And a photoconductive layer formed on the support. However, it covers the defects of the support, improves the coating property of the photoconductive layer, improves the adhesion between the photoconductive layer and the support, protects the photoconductive layer from electrical damage, improves the charging property, and improves the photoconductivity from the support. It is effective to provide an intermediate layer between the photoconductive layer and the support in order to improve the charge injection property to the layer. Therefore, the intermediate layer in the electrophotographic photosensitive member is required to have many functions such as covering property, adhesive property, mechanical strength, appropriate conductivity and electric barrier property.

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

(I) Resin thin film containing no conductive filler (ii) Resin thin film containing conductive filler (iii) Laminated thin film of (i) above on the thin film of (ii) above ( Since the thin film of i) does not contain a conductive filler, the resistance of the film is high, and it must be used as a thick film to cover the defects on the support. Therefore, it has a drawback that the residual potential becomes high at initial and repeated use. In order to put the thin film of (i) into practical use, defects on the support are reduced and the thickness of the intermediate layer is made extremely thin. There is a need to.

On the other hand, the thin films of (ii) and (iii) above have the advantage that suitable conductivity can be imparted by dispersing the conductive filler, but if the dispersibility of the conductive filler is poor, the intermediate layer of the intermediate layer Electrical characteristics such as resistance and permittivity change, and have a great influence on potential characteristics and image quality. Also, 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 will also decrease.

So far, as conductive fillers for the intermediate layer, metals (JP-A-58-181054), metal oxides (JP-A-54-151843), and metal nitrides (JP-A-1-1184848). Gazette) etc. have been reported.

[0007]

However, in the electrophotographic photosensitive member using the conventional conductive filler as the filler of the intermediate layer, the environmental dependence such as temperature and humidity is large,
It has been difficult to produce a photoconductor having stable potential characteristics and image characteristics in all environments from low temperature and low humidity to high temperature and high humidity. For example, under low temperature and low humidity, which causes an increase in the resistance of the intermediate layer, when the photoconductor was repeatedly used, charges were accumulated in the intermediate layer and the residual potential and the bright part potential increased. On the other hand, under high temperature and high humidity which causes a decrease in the resistance of the intermediate layer, the electrical barrier ability of the intermediate layer was decreased, carrier injection from the support was accelerated, and a decrease in dark area potential was observed during repeated use. As a result, in addition to a 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) and fogging tend to occur in the image. .

As described above, it is considered that the characteristics of the photoconductor are changed due to the change of environment because 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, which makes the potential characteristics and the image characteristics susceptible to 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 low humidity to high temperature high humidity, and an electrophotographic apparatus using this electrophotographic photosensitive member. Is to provide.

[0010]

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

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

The electrophotographic photosensitive member 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 of tin oxide fine particles containing phosphorus.

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

In the present invention, the specific resistance of the powder is 10 to 1
00 Ωcm is preferable. In the present invention, the powder resistivity is the resistance measuring device Loresta AP (Lorest) manufactured by Mitsubishi Yuka
aAP). The powder to be measured is 500
The sample was attached to the above measuring device as a coin-shaped sample which was hardened by a pressure of kg / cm ² .

The phosphorus content is preferably 0.01 to 30% by weight, more preferably 0.10 to 10% by weight, based on the tin oxide fine particles. The tin oxide fine particles containing phosphorus preferably have an average particle diameter of 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 the centrifugal sedimentation method.

Generally, when the average particle size of the filler is small, it becomes difficult to disperse and re-aggregate easily, but the filler used in the present invention has excellent dispersibility. The content of the filler is 1.0 to 90% by weight with respect to the intermediate layer,
Further, 5.0 to 80% by weight is preferable.

Examples of the binder resin used in the intermediate layer of the present invention include phenol resin, polyurethane, polyamide, polyimide, polyamideimide, polyamic acid, polyvinyl acetal, epoxy resin, acrylic resin,
Melamine resin or polyester is preferable. These resins may be used alone or in combination of two or more. These resins have good adhesion 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 resin, polyurethane and polyamic acid are particularly preferable.

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 (silane coupling agent or 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 is 10 ¹³ Ωcm or less, and further 10 ¹² Ωcm or less 10 Ω.
cm or more is preferable. 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 this intermediate layer, and measuring the current value flowing between both electrodes of the aluminum plate and the gold thin film as 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 tin oxide fine particles containing phosphorus. Furthermore, 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 material,
The charge transport material is contained in the same layer to generate and move photocarriers in the same layer.

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

Examples of the charge generating substance include azo pigments (eg, monoazo, bisazo, trisazo, etc.), metal and metal-free phthalocyanine pigments, indigo pigments (eg, indigo, thioindigo), quinone pigments (eg, anthanthrone, Pyrene quinone), perylene pigments (for example, perylene anhydride, perylene imide, etc.), squalium dyes, pyrylium, thiapyrylium salts, triphenylmethane dyes and the like. Further, an inorganic material such as selenium, selenium-tellurium, or amorphous silicon can also be used as the charge generation substance.

The charge transport material includes an electron transport material and a hole transport material. Examples of the electron transport 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.), heterocyclic compounds (eg, carbazole, indole, imidazole, oxazole, thiazole, etc.)
Oxadiazole, pyrazole, pyrazoline, thiadiazole, triazole, etc.), hydrazone 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, etc.), benzidine compounds, triarylamine compounds and the like.

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 the charge generating material and the charge transporting material, and further 20 to 7% by weight.
It is preferable to contain 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, further 1
0 to 30 μm is preferable. The charge generation layer preferably contains 10 to 100% by weight, and more preferably 40 to 100% by weight of the charge generation substance. The charge transport layer preferably contains 20 to 80% by weight, more preferably 30 to 70% by weight of the charge transport material.

The electrophotographic photoreceptor of the present invention can be obtained by vacuum vapor deposition of the material used for the photoconductive layer or a suitable binder resin in combination to form a film on a support.

As the binder resin for the photoconductive layer, for example, polyvinyl acetal, polycarbonate, polystyrene,
Polyester, polyacetic acid ester, polymethacrylic acid ester, acrylic resin, cellulose resin and the like are preferably used.

Free carriers may be injected from the intermediate layer into the photoconductive layer depending on the kind of material of the photoconductive layer.
The chargeability of the photoconductor is reduced, which greatly affects the image characteristics. In such a case, if necessary, a barrier layer having an electrical barrier property (for example, a suitable resin thin film) is provided between the intermediate layer and the photoconductive layer to effectively suppress the injection of free carriers. can do. As the barrier layer, for example, polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acid, methyl cellulose,
Water-soluble resins such as ethyl cellulose, polyglutamic acid, casein, and starch, and resins such as polyamide, polyimide, polyamideimide, polyamic acid, melamine resin, epoxy resin, polyurethane, and polyglutamic acid ester can be used. In particular, coatability, adhesion,
Polyamide is preferable as the barrier layer in terms of solvent resistance, electric barrier property, resistance and the like. As a polyamide,
A low-crystalline or non-crystalline copolymerized nylon that can be applied in a solution state is suitable. The thickness of the barrier layer is preferably 0.1 to 2 μm.

In the electrophotographic photosensitive member of the present invention, a protective layer may be provided on the photoconductive layer. The protective layer is mainly composed of resin. Examples of the material forming the protective layer include polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone, polyallyl ether, polyacetal, nylon, phenol resin, 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, and further 1 to
10 μm is preferable.

The support may be a metal or alloy such as aluminum, aluminum alloy, copper, titanium or stainless steel, or a polymer material such as polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene or polystyrene, or hard paper. It can be manufactured using the above materials. The shape of the support is cylindrical,
A belt shape or a sheet shape is preferable. 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 by dispersing a conductive substance in the support.

The electrophotographic photosensitive member of the present invention is not only used in an electrophotographic copying machine, but also widely used in electrophotographic application techniques such as laser beam printers, CRT printers, LED printers, liquid crystal printers, facsimiles, and laser plate making. be able to.

The electrophotographic photosensitive member according to the present invention can realize stable potential characteristics and excellent image formation under 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 structure 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 photosensitive member of the present invention, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed.
In the course of its rotation, the photosensitive member 1 is uniformly charged at its peripheral surface by a predetermined positive or negative potential by a charging means 2, and then at an exposure section 3 an optical image exposure L (slit exposure or slit exposure by an image exposure means not shown). Laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is transferred by the transfer means 5.
Thus, the recording material P is fed between the photoconductor 1 and the transfer means 5 from a paper feed unit (not shown) in synchronization with the rotation of the photoconductor 1.
Are sequentially transferred to the surface. The recording material P that has undergone the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where it undergoes image fixing and is printed out as a copy. The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning unit 6 to remove the transfer residual toner,
The charge is removed by the pre-exposure means 7 and repeatedly used for image formation. As a uniform charging means 2 for the photoconductor 1, a corona charging device is generally widely used. Also, as the transfer device 5, corona transfer means is generally widely used. The electrophotographic apparatus is configured by integrally combining a plurality of constituent elements such as the photoconductor, the developing unit, and the cleaning unit described above as an apparatus unit, and the unit is configured to be detachable from the apparatus body. May be. For example, the photosensitive member 1 and the cleaning means 6 may be integrated into one device unit, and may be detachably configured by using guide means such as a rail of the device body. At this time, the above-mentioned apparatus unit may be provided with a charging means and / or a developing means. Further, 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 an original, or makes the original read into a signal, and scans a laser beam according to the signal.
This is performed by driving the light emitting diode array or the liquid crystal shutter array.

[0036]

【Example】

Example 1 140 parts by weight of a filler composed of tin oxide fine particles containing phosphorus (powder specific resistance: 25 Ωcm), and a resol type phenol resin (trade name: Praiophen J-325, 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 by a ball mill for about 30 hours. The average particle size of the filler contained in this dispersion is measured with a particle size analyzer (trade name CA
It was 0.08 μm as measured by the centrifugal sedimentation method using PA-700, manufactured by Horiba Ltd. The phosphorus content in the fine particles was 1% by weight.

The dispersion liquid thus prepared was used to prepare an outer diameter of 30
mm, length: 360 mm, coated on aluminum cylinder (surface roughness Rmax 5 μm) by dipping method, 1
It was heated and cured at 40 ° C. for 30 minutes to form an intermediate layer having a thickness of 15 μm. The surface roughness Rmax at this time was measured and found to be 0.4 μm. The roughness Rmax is JISB.
0601.

Next, copolymerized nylon (trade name Amilan C
10 parts by weight of M8000, manufactured by Toray Industries, Inc., are dissolved in a mixed solution of 60 parts by weight of methanol and 40 parts by weight of butanol, the solution is 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 titanyloxyphthalocyanine pigment, 2 parts by weight of polyvinyl butyral (trade name BX-1, manufactured by Sekisui Chemical Co., Ltd.), cyclohexanone 34
After dispersing a solution consisting of parts by weight in a sand mill for 8 hours,
60 parts by weight of tetrahydrofuran was added to prepare a dispersion liquid 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 film thickness of the charge generation layer was about 0.2 μm.

Then, 50 parts by weight of a triarylamine compound represented by the following structural formula:

[0041]

[Outer 1]

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

The electrophotographic photosensitive member of the present invention thus prepared was mounted on a regular development type electrophotographic copying machine,
The charging-exposure-transfer-cleaning process was repeated with a 0.8 second cycle. The electrophotographic characteristics of this photoreceptor were evaluated under the environment of low temperature and low humidity (15 ° C., 15% RH). As a result, as shown in Table 1, with this photosensitive member, a large difference can be formed between the dark portion potential (V _D ) and the light portion potential ( _VL ) and sufficient contrast can be obtained. . Furthermore, when images were continuously printed on 10000 sheets of recording paper, neither the dark portion potential nor the light portion potential 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
An electrophotographic photosensitive member of the present invention was prepared in the same manner as in Example 1 except that m was replaced by m. The electrophotographic photosensitive member thus prepared was mounted on a reversal development type printer, and the process of charging-exposure-transfer-cleaning was repeated in a cycle of 6 seconds. The electrophotographic characteristics of this photoconductor were evaluated under the environment of high temperature and high humidity (30 ° C., 85% RH). As a result, as shown in Table 2, with this photoreceptor, a large difference can be formed between the dark portion potential (V _D ) and the light portion potential ( _VL ) and sufficient contrast could be obtained. . Furthermore, when images were continuously printed on 5000 sheets of recording paper, neither the dark portion potential nor the light portion potential changed,
In addition, an image with a very stable image quality was obtained without black dot defects and fog.

[0046]

[Table 2]

Example 3 The filler was changed to a powder made of tin oxide fine particles having a phosphorus content of 5% by weight (powder specific resistance: 12 Ωcm), and the binder resin in the intermediate layer was made of polyurethane (trade name: Nipolan 2304). ., Manufactured by Nippon Polyurethane Co., Ltd., and other conditions were the same as in Example 1 to prepare an electrophotographic photoreceptor of the present invention. At this time, the average particle size of the filler contained in the dispersion for the intermediate layer was measured by the same method as in Example 1,
It was 0.10 μm.

The electrophotographic photosensitive member thus prepared was mounted on a regular developing type electrophotographic copying machine, and the process of charging-exposure-transfer-cleaning was repeated in a cycle of 0.8 seconds. Low temperature and low humidity (15 ℃,
The electrophotographic characteristics were evaluated under the environment of 15% RH.
As a result, as shown in Table 3, with this photosensitive member, a large difference can be formed between the dark portion potential (V _D ) and the light portion potential ( _VL ) and sufficient contrast could be obtained. . Further, when images were continuously formed on 10000 sheets of recording paper, there were no fluctuations in the potential, and very stable image characteristics were exhibited.

[0049]

[Table 3]

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

[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 found to be 0.09.
was μm.

The electrophotographic photosensitive member thus prepared was mounted in an electrophotographic copying machine of a regular developing system, and the process of charging-exposure-transfer-cleaning was repeated in a cycle of 0.8 seconds. Low temperature and low humidity (15 ℃,
The electrophotographic characteristics were evaluated under the environment of 15% RH.
As a result, as shown in Table 4, with this photosensitive member, a large difference can be formed between the dark portion potential (V _D ) and the light portion potential ( _VL ) and sufficient contrast could be obtained. . Further, when images were continuously formed on 10000 sheets of recording paper, there were no fluctuations in potential and very stable image characteristics were exhibited.

[0053]

[Table 4]

Comparative Examples 1 and 2 The intermediate layer of Example 1 was replaced with an intermediate layer formed by using the following coating solution, and otherwise the same as in Example 1 and Comparative Example 1
Electrophotographic photoreceptors of 2 and 2 were prepared. Each of the electrophotographic photoconductors thus prepared was mounted in an electrophotographic copying machine of a regular developing system, and the process of charging-exposure-transfer-cleaning was repeated for 0.8 second cycle. Low temperature and humidity (15 ℃, 15% RH) for these photoconductors
The electrophotographic characteristics were evaluated under the following environment. As a result, Table 5
As shown in FIG. 5, in any case, a large difference could be formed between the dark portion potential (V _D ) and the light portion potential ( _VL ) in the initial stage, and sufficient contrast was obtained. However, when images were continuously formed on 10000 sheets of recording paper, a decrease in dark area potential and an increase in light area potential were observed for all electrophotographic photoreceptors.

Formulation of Comparative Example 1 Powder containing fine particles of titanium oxide having a tin oxide coating layer containing antimony 100 parts by weight (trade name: ECTT-
1. Titanium Industry Co., Ltd.-Resol type phenolic resin 70 parts by weight (trade name Praiophen J-325) -Methyl cellosolve 80 parts by weight

Prescription for Comparative Example 2 Powder composed of tin oxide fine particles containing antimony 12
0 parts by weight (trade name T-1, manufactured by Mitsubishi Materials Corp.) 70 parts by weight of polyester polyurethane (trade name Nipporan 2304) 2-methoxy-1-propanol 80 parts by weight

[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 replaced by m. These electrophotographic photoreceptors of the present invention were mounted on an electrophotographic printer of reversal development, and the process of charging-exposure-transfer-cleaning was repeated in a cycle of 6 seconds. The electrophotographic characteristics of these photoconductors were evaluated under the environment of high temperature and high humidity (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 light portion potential ( _VL ) and sufficient contrast can be obtained. It was Furthermore, when images were continuously printed on 5000 sheets of recording paper, almost no fluctuations in the dark portion potential and the light portion potential were observed in any of the electrophotographic photosensitive members, and there were no unnecessary black spots or fog. Images with very stable image quality were obtained.

[0059]

[Table 6]

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

[0061]

[Table 7]

Example 7 An aluminum plate having a length of 250 mm, a width of 150 mm, and a thickness of 0.5 mm was coated with the same dispersion liquid for intermediate layer as in Example 1 using a Meyer bar, and was dried and cured at 140 ° C. for 30 minutes to give a thickness. A 5 μm intermediate layer was formed.

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

[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 this liquid, and the mixture was further dispersed for 2 hours. Cyclohexanone 10 was added to this dispersion.
0 parts by weight and 100 parts by weight of tetrahydrofuran were added to dilute the solution, and the intermediate layer was coated with a Meyer bar to a thickness of 0.2 μm to form a charge generation layer.

Then, a styryl compound 50 having the following structural formula
Parts by weight

[0066]

[Outside 4] Fifty parts by weight of polycarbonate (trade name Iupilon Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) 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 and film thickness is 2
An electrophotographic photoreceptor of the present invention was prepared by forming a 0 μm charge transport layer.

With respect to the electrophotographic photosensitive member thus prepared, an electrostatic copying machine test apparatus (trade name Model SP
-428, manufactured by Kawaguchi Electric Co., Ltd., was used to evaluate the charging characteristics. The charging characteristics were evaluated by negatively charging the electrophotographic photosensitive member with a corona discharge of -5 kV, leaving it in the dark for 1 second, and then exposing it to light with an illuminance of 10 lux using a halogen lamp, and the initial surface potential at this time. (V ₀ ), the amount of exposure (E _1/2 ) required to attenuate the surface potential after standing in the dark to ½, and the residual potential (V _r ) were measured. The evaluation results are shown in Table 8.

Examples 8 and 9 The same intermediate layers as in Examples 3 and 4 were used.
A barrier layer was provided on the intermediate layer, and the electrophotographic photosensitive members of Examples 8 and 9 were prepared in the same manner as in Example 7 except for the above, and the charging characteristics of the respective electrophotographic photosensitive members were performed 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 dispersion liquid for barrier layer as in Example 1.

The evaluation results are shown in Table 8.

[0070]

[Table 8]

Comparative Examples 5 and 6 The intermediate layers were replaced by the same intermediate layers as those of Comparative Examples 1 and 2, and the electrophotographic photosensitive members of Comparative Examples 5 and 6 were prepared in the same manner as in Example 8 except for the above. The charging characteristics of each electrophotographic photosensitive member were evaluated in the same manner as in 7. Table 9 shows the evaluation results.
It was shown to. The electrophotographic sensitivities of these photoconductors were 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 drawings]

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

[Explanation of reference numerals] 1 electrophotographic photosensitive member 2 charging means 3 exposure section 4 developing means 5 transfer means 6 cleaning means 7 pre-exposure means 8 image fixing means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Akira Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuma Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (9)

[Claims] 1. An electrophotography comprising a support, an intermediate layer and a photoconductive layer in this order from the support side, and powder containing tin-containing fine particles of phosphorus contained in the intermediate layer. Photoconductor. 2. The average particle diameter of the fine particles is 0.02 to 0.
The electrophotographic photosensitive member according to claim 1, having a thickness of 2 μm. 3. The average particle diameter 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 phosphorus content is 0.01 to 30% by weight based on the fine particles. 5. The electrophotographic photosensitive member according to claim 4, wherein the content is 0.10 to 10% by weight. 6. The binder resin for the intermediate layer is selected from the group consisting of phenol resin, polyurethane, polyamide, polyimide, polyamide imide, polyamic acid, polyvinyl acetal, epoxy resin, acrylic resin, melamine resin and polyester. The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is used. 7. A phenol resin as the binder resin,
The electrophotographic photosensitive member according to claim 6, wherein one selected from polyurethane and polyamic acid is used. 8. The electrophotographic photosensitive member according to claim 1, further comprising a barrier layer between the intermediate layer and the photoconductive layer. 9. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, and image exposure for forming an electrostatic latent image by performing image exposure on the charged electrophotographic photosensitive member. An electrophotographic apparatus comprising means and developing means for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner.