JPH06301227A - Laminated electrophotographic sensitive body, its production, and device to remove coating layer of photosensitive body - Google Patents

Abstract

PURPOSE:To provide a laminated electrophotographic sensitive body having high sensitivity and which can suppresses image faults due to repetition of use, and to provide a production method of a laminated electrophotographic sensitive body and a device to remove a photosensitive coating layer so that the edge part of the coating layer of a photosensitive body formed on a cylindrical conductive supporting body can be revmoved with a simple mechanism while preventing adverse infulence of the solvent used for removing the film. CONSTITUTION:The laminated electrophotographic sensitive body has an under coating layer 1 comprising copolymer nylon resin and titanium oxide without conductivity treatment with >=95wt.% titanium oxide content. When the photosensitive coating layer 5 is formed by dipping on a conductive supporting body 1, the photosensitive coating layer on the lower edge part of the supporting body is removed by attaching a protective member 6 to protect the layer not to be removed and then removing the coating layer in the edge part side of the supporting body from the protective member 6 in the presence of a solvent to remove the film.

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 using an organic photoconductive material, and more particularly to a laminated electrophotographic photosensitive member having high sensitivity and excellent repeated stability.

The present invention also relates to a method and apparatus for manufacturing an electrophotographic photosensitive member, and more particularly to a method for manufacturing an electrophotographic photosensitive member formed by removing the coating layer at the lower end.

[0003]

2. Description of the Related Art Electrophotographic photoreceptors currently in practical use can be roughly classified into those using an inorganic material and those using an organic material. Typical inorganic photoreceptors include selenium-based ones such as amorphous selenium (a-Se) and amorphous selenium arsenic (a-As ₇ Se ₃ ), dye-sensitized zinc oxide (ZnO), or cadmium sulfide. (Cd
There are those in which S) is dispersed in a binder resin, those in which amorphous silicon (a-Si) is used, and the like.

On the other hand, in recent years, organic photoconductive materials have been developed and used more than the conventionally used inorganic materials. Typical organic photoreceptors include 2,4,7-trinitro-9-fluorenone (TNF) and poly-N-vinylcarbazole (PV
For example, a charge transfer complex with K) is used.

These photoreceptors have many advantages as well as drawbacks. For example, selenium and CdS
The photoconductor using is problematic in heat resistance and storage stability, and has a limitation that it cannot be easily discarded because it has toxicity and must be recovered. ZnO resin-dispersed photoreceptors are now almost obsolete because of their low sensitivity and lack of durability. Although the a-Si photoconductor has excellent advantages such as high sensitivity and high printing durability, there are problems such as high manufacturing cost due to the complexity of the manufacturing process and image defects due to defects during film formation. Is left.

On the other hand, a photoconductor using an organic material has some problems in sensitivity, durability, environmental stability, etc., but is more common than inorganic materials in terms of toxicity, cost, material design freedom, etc. There are advantages. Since there are various organic materials and various arrangements can be made by synthesis, it is possible to avoid problems such as storage stability and toxicity by appropriately selecting them, and it is possible to manufacture at low cost. We are energetically considering. However, the organic photoreceptor also has a problem of low sensitivity, and its improvement is being promoted. The PVK-TNF charge transfer complex described above was one of the improvements, but it did not reach sufficient sensitivity.

Therefore, various sensitizing methods have been proposed from the enthusiastic examination of each company, and among them, as shown in FIG. 11, substances that generate charge carriers when irradiated with light (hereinafter referred to as "charge generation"). A layer 3 (hereinafter referred to as “substance”) and a layer mainly composed of a substance (hereinafter referred to as “charge transport substance”) that accepts and transports charge carriers generated in the charge generation layer (hereinafter referred to as “charge generation layer”). 4 (hereinafter referred to as “charge transport layer”) and a conductive type support 1 laminated on the laminated type photoreceptor (hereinafter referred to as “function-separated type photoreceptor”) exhibit excellent sensitization, It has accounted for the majority of the organic photoconductor structures that have been commercialized. Further, it is expected to be the mainstream of photoconductors in the future due to the improvement of durability in recent years.

Further, an undercoat layer is provided for the purpose of improving chargeability, preventing unnecessary charge injection from the support, covering defects on the support, preventing pinholes, improving the adhesiveness of the photosensitive layer, and the like. As a result, durability is improving.

The coating method of the organic electrophotographic photoreceptor is a spray method, a bar coating method, a roll coating method,
A blade method, a ring method, a dipping method and the like can be mentioned. In particular, the dip coating method is a method of forming a photosensitive layer by immersing a conductive substrate in a coating tank filled with a photoreceptor coating liquid and then pulling it up at a constant rate or a rate that changes sequentially, but it is relatively simple. Since it is excellent in productivity and cost, it is often used for manufacturing electrophotographic photoreceptors.

[0010]

Although the sensitivity and printing durability have been improved by using the above-mentioned function-separated type photoreceptor, in recent years, it has been required to increase the speed and life of copying machines. Further, it is necessary to improve the sensitivity of the photoconductor. However, if you try to improve the sensitivity, the chargeability is low,
There is a problem that the dark decay becomes large and the repeated stability becomes poor. Further, since a copying machine, a printer or the like may be used under any environment, it is required that the characteristics of the photoconductor be stable under any environmental conditions.

For the purpose of improving these problems, it is known to provide a resin layer called an undercoat layer between the conductive support and the charge generating layer, as disclosed in JP-A-51-114132.
No. 2-25638, No. 56-21129, No. 58-95351, No. 60-218655, No. 61-163346, No. 61-17946.
4, JP-A 61-254951, JP-A 2-1
No. 81158 is proposed.

The resin for the undercoat layer is preferably insoluble in the solvent (halogen-based, benzene-based, ether-based, ester-based, ketone-based, etc.) of the charge generation layer coating liquid,
Generally, alcohol or water-soluble resin is used. However, if only such a resin layer is provided as the undercoat layer, the residual potential increases remarkably after repeated use of tens of thousands of times under low humidity conditions, and image defects such as fog in white letters occur. Under high humidity conditions, there is a problem that a clear image cannot be obtained due to insufficient image density due to a decrease in charging potential. In addition, for the purpose of preventing coating film defects due to substrate defects and using a rough substrate for cost reduction, thickening of the undercoat layer is required, but in this case environmental stability is It is even more problematic.

A photoreceptor using an alcohol-soluble resin (N-alkoxymethylated nylon resin) described in JP-A-58-95351 as an undercoat layer is less susceptible to humidity, but has poor sensitivity and is clear. It is difficult to obtain a thick image for the undercoat layer. Further, a photoreceptor using an undercoat layer made of alumina-coated titanium oxide and a polyamide resin as described in JP-A-2-181158, etc., is a thick film of the undercoat layer by mixing titanium oxide in the undercoat layer. However, there are still problems such as repeated stability depending on environmental conditions.

With the improvement in the performance of the above-described organic electrophotographic photoreceptor, it is expected that the performance of the copying machine, the LBP and the like will be improved, especially the stability of the developing characteristics will be good, and the possibility of mounting in a high speed model. It has started to be done. The positional relationship between the photoconductor and the developing sleeve is very important when considering the stabilization of the developing characteristics and mounting on high-speed models, and the method of using the developing color roller is recommended because the distance between them is kept constant. Has been adopted. Therefore, a large stress is applied to the portion in contact with the color roller, and in the case where the coating layer of the photoconductor is present, the film peeling has an adverse effect. Therefore,
When the coating layer of the electrophotographic photoreceptor is formed by dip coating, it is necessary to remove the coating layer at the lower end of the substrate.

Conventionally, as a method of removing the coating layer at the lower end of the substrate, for example, a method of removing with a brush (Japanese Patent Laid-Open No. 60-
9731), a method using a scraping member (Japanese Patent Application Laid-Open No. Sho 6-66).
1-222271), a method of burning and sublimating by laser light irradiation (JP-A-3-144458).
Etc. are known, and JP-A-63-27846 describes that a blocking agent is provided for removal.

However, in the conventional method, when the coating layer is removed, the non-removed portion is left behind by the vapor or the splash of the removing solvent, which causes a problem of image defects. on the other hand,
The method described in Japanese Patent Laid-Open No. 63-27846 has the drawback that the mechanism is complicated and the operation is not easy.

The present invention has been made in view of the above problems in the prior art.

Therefore, a first object of the present invention is to provide a multi-layer type electrophotographic photosensitive member which has high sensitivity under any environmental conditions and can suppress image defects due to repeated use.

A second object of the present invention is to remove the end portion of the coating layer of the photosensitive member provided on the cylindrical conductive support with a simple mechanism while preventing the removal solvent from being adversely affected. An object of the present invention is to provide a method of manufacturing a laminated type electrophotographic photoconductor and a photoconductor coating layer removing device.

[0020]

To achieve the above object, in the present invention, an electrophotographic photosensitive member having an undercoat layer, a charge generating layer and a charge transporting layer on a conductive support is used as a copolymer nylon. Consists of resin and titanium oxide that has not been subjected to a conductive treatment, and the content of the titanium oxide is 95% by weight.
The above-mentioned undercoat layer is used.

Further, in the production of a laminated electrophotographic photosensitive member having a photosensitive material coating layer provided on a conductive support by dip coating, the photosensitive material coating layer is formed and then the photosensitive material coating layer at the lower end of the support is formed. At the time of removal, a protective member for protecting the non-removed layer is provided at the lower end of the support, and the coating layer on the end of the support with respect to the protective member is removed in the presence of a removal solvent.

The photoconductor coating layer removing device is constituted by a wiping tank for the photoconductor coating layer on the conductive support, which is equipped with a protective member for the shutter mechanism and a solvent removing member.

As the protective member of the shutter mechanism, one having a concentric opening / closing mechanism composed of a plurality of blade members is used.

[0024]

When conductive titanium oxide [powder resistance 10 ² Ωcm or less (100 kg / cm ² green powder)] is used, problems such as insufficient charging potential and reduction in charging potential during repeated use occur, Although the phenomenon becomes more remarkable as the content thereof increases, it can be avoided by using the non-conductive titanium oxide in the present invention.

By using a protective member that opens and closes on a concentric circle, it is possible to prevent the adverse effect of the solvent at the time of removing the photoconductor coating layer, and it is possible to deal with cylindrical conductive supports having different diameters. No replacement required.

The present invention will be further described below with reference to the drawings.

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member of the present invention, in which 1 is a conductive support, 2 is an undercoat layer, 3 is a charge generation layer, and 4 is a charge transport layer.

In the present invention, as the conductive support,
The substrate itself having conductivity, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, nickel, titanium or the like can be used, and aluminum, aluminum alloy, indium oxide, tin oxide or the like is vapor-deposited, or
It is possible to use coated plastics and papers, plastics and papers containing conductive particles, and plastics containing conductive polymers, and the shapes thereof include drum shape, sheet shape, seamless belt shape and the like. Can be used.

Next, for reasons such as scratches on the surface of the conductive substrate, coating of irregularities, prevention of deterioration of chargeability during repeated use, and improvement of charging characteristics in a low temperature / low humidity environment, the conductive substrate and the charge generating layer / An undercoat layer may be provided between the charge transport layer and the charge transport layer.

The resin for the undercoat layer provided between the conductive support and the charge generating layer is a copolymer nylon resin, and the titanium oxide is a non-conductive one. The particle diameter of the non-conductive titanium oxide is 1 μm or less, preferably 0.01
~ 0.2 μm, and the mixing ratio is 95% by weight.
It is preferably up to 99%, and if the content is outside these ranges, problems occur in environmental stability, repeated stability and film physical properties.

As materials for the undercoat layer, polyamide, copolymer nylon, polyvinyl alcohol, polyurethane, polyester, epoxy, phenol resin, casein, cellulose, gelatin and the like have been conventionally known, and particularly alcohol-soluble copolymer. Nylon is often used. These are water and various organic solvents, especially water, methanol, ethanol, butanol as a single solvent, or water / alcohol, a mixed solvent of two or more alcohols, or dichloroethane, chloroform, trichloroethane, trichloroethylene, perchlorethylene, etc. It is dissolved in a mixed solvent of a chlorine-based solvent and alcohol and applied on the surface of the conductive substrate.

In addition, if necessary, zinc oxide, titanium oxide, tin oxide, indium oxide, zinc oxide, titanium oxide, tin oxide, etc. may be used for reasons such as setting the volume resistivity of the undercoat layer and improving the repeated aging characteristics under low temperature / low humidity environment. It is known to disperse and contain inorganic pigments such as silica and antimony oxide.

A mixture of the above-mentioned methoxymethylated nylon resin and non-conductive titanium oxide is mixed with methanol, ethanol or other lower alcohol, or water with a mixture thereof,
Alternatively, an undercoat layer is formed by dispersing and preparing with a solvent in which alcohol is mixed with any one of an aromatic solvent, a halogen solvent, an ester solvent and the like, and applying the coating liquid on a conductive support. . The thickness of the undercoat layer is 0.01 to 10 μm.
m, preferably 0.05 to 5 μm. Examples of the method for dispersing the coating liquid for the undercoat layer include a ball mill, a sand mill, an attritor, a vibration mill and an ultrasonic disperser. As the coating means, there are coating methods such as dip coater, blade coater, applicator, rod coater, knife coater, casting, ring and spray. Next, the present invention will be described in more detail.

A charge generation layer is formed on the undercoat layer. The charge generation layer of the present invention is mainly composed of a charge generation material that generates a charge upon irradiation with light, and optionally contains a known binder, plasticizer and sensitizer.

Examples of the charge generating material used in the charge generating layer include bisazo compounds such as chlorodian blue, polycyclic quinone compounds such as quinacridone, anthraquinone and dibromoanthanthrone, and perylene compounds such as perylene imide and perylene anhydride. Compounds, metal phthalocyanines and metal-free phthalocyanines, phthalocyanine compounds such as halogenated metal-free phthalocyanines, squarylium dyes,
Azurenium dye, thiapyrylium dye, and azo pigment having a carbazole skeleton, styrylstilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bisstilbene skeleton, distyryloxadiazole skeleton or distyrylcarbazole skeleton , And azurenium salt compounds are known.

As a method for forming the charge generating layer, there are a method of directly forming a film of a compound by vacuum vapor deposition and a method of dispersing and coating the compound in a binder resin solution to form a film, and the latter method is generally preferable. The thickness of the layer is 0.05 to 5 μm, preferably 0.1 to 1 μm. In the case of production by coating, as the method of mixing and dispersing the charge generating material in the binder resin solution and the coating method, the same method as that for the undercoat layer is used. Examples of the binder resin for the binder resin solution include melamine resin, epoxy resin, silicone resin, polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate resin, and phenoxy resin. As a solvent for dissolving the resin, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, esters such as butyl acetate, tetrahydrofuran, ethers such as dioxane, benzene, toluene, aromatic hydrocarbons such as xylene, N, N
-Aprotic polar solvents such as dimethylformamide and dimethylsulfoxide can be used.

Examples of the charge transport material of the charge transport layer provided on the charge generation layer include hydrazone compounds, pyrazoline compounds, triphenylamine compounds, triphenylmethane compounds, stilbene compounds, oxadiazole compounds. Etc. can be used, and the charge transport liquid is prepared by dissolving the charge transport substance in the binder resin solution. As the coating method for the charge transport layer, the same method as for the undercoat layer is used.

The thickness of the charge transport layer is 5 to 50 μm, preferably 10 to 40 μm. Further, the photosensitive layer of the electrophotographic photoreceptor of the present invention contains one or more electron-accepting substances or dyes for the purpose of improving sensitivity, suppressing increase in residual potential during repeated use and suppressing fatigue. May be included.

Examples of the electron-accepting substance used here include acid anhydrides such as succinic anhydride, maleic anhydride, phthalic anhydride and 4-chloronaphthalic anhydride, tetracyanoethylene, terephthalmalone. Cyano compounds such as dinitrile, aldehydes such as 4-nitrobenzaldehyde, anthraquinones, anthraquinones such as 1-nitroanthraquinone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone and the like A polycyclic or heterocyclic nitro compound can be used as a chemical sensitizer.

As the dye, for example, an organic photoconductive compound such as a xanthene dye, a thiazine dye, a triphenylmethane dye, a quinoline dye or a copper phthalocyanine pigment can be used as an optical sensitizer.

Further, the photosensitive layer of the electrophotographic photoreceptor of the present invention has the following properties in order to improve moldability, flexibility and mechanical strength.
It may contain a well-known plasticizer. Examples of the plasticizer include dibasic acid ester, fatty acid ester, phosphoric acid ester, phthalic acid ester, chlorinated paraffin, and epoxy type plasticizer. Moreover, you may contain a leveling agent, an antioxidant, an ultraviolet absorber, etc. as needed.

Next, a cross-sectional view and a plan view of an example of the photoconductor coating layer removing device of the present invention are shown in FIGS. 2 and 3, respectively.

In the figure, 1 is a cylindrical conductive support, 5
Is a coating layer of the photoconductor, and the coating layer on the end portion side of the support from the protective member 6 which can be opened and closed concentrically by the movement of a plurality of blade members 7 is removed in a solvent in the lower end wiping tank 8 by a brush 9 It is configured to be removed by using. In order to protect the non-removed part by coming into contact with or close to the cylindrical support, it is desirable that the number of blade members is 6 or more, and if it is less than that, the influence of the removal solvent cannot be prevented. .

In FIG. 3, the shape of the blade of the portion which is in contact with or close to the cylindrical conductive support is linear, but the shape of the blade is cylindrical conductive support. It may have an appropriate curvature in order to improve the close contact with the body. An example of a device with improved closeness is shown in FIGS. 4 and 5.

FIG. 6, FIG. 7, FIG. 8 and FIG. 9 are examples of a sectional view and a plan view of the photoconductor coating layer removing device in which the protective member or the lower end wiping tank can be moved horizontally by the spring 7. is there. In FIGS. 6 to 9, a spring is used as the means capable of moving in the horizontal direction, but other suitable means such as a hydraulic system or a pneumatic system may be used. Further, a method of smoothly moving may be used in combination with a bearing or other means.

As described above, since the protective member and the lower end wiping tank can be moved horizontally, the protective member can be opened and closed concentrically, so that the lower end wiping tank of the electrophotographic photoconductor can be positioned, and the apparatus can be positioned. There is no need for centering.

Although a brush is used as a method for removing the coating layer in FIGS. 2 to 9, any other method such as ultrasonic wave, a blade, a wiping tape or the like may be used. The solvent for removal may be one that dissolves the coating layer, one that does not dissolve it, or any solvent.

The removal of the photoconductor coating layer is carried out by rubbing the cylindrical conductive support provided with the coating layer and the removing member, but the method is to rotate the cylindrical conductive support. Any of a system, a system in which the removing member rotates, a system in which the wiping tank itself rotates, and a system in which the support and the removing member rotate together may be used. Further, the coating layer to be removed may be on both inner and outer surfaces of the end portion of the support or only one of the surfaces.

[0049]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 Methylmethyl alcohol 28.7 parts by weight and 1,2-dichloroethane 53.3 parts by weight in an azeotropic composition mixed solvent were added to a methoxymethylated nylon resin (Teijin Kagaku: Toresin EF-30T).
0.9 parts by weight and non-conductive titanium oxide (Ishihara Sangyo: TTO
A mixture of -55A) and 17.1 parts by weight was dispersed in a paint shaker for 8 hours to prepare an undercoat layer coating solution.

The coating solution prepared in this manner was applied to a thickness of 1 m.
The aluminum drum-shaped substrate 1 of mt × 80 mmφ × 340 mm was coated with the dip coating apparatus shown in FIG. 9 so that the coating layer of the photoconductor was not provided on the upper end 10 mm of the substrate. 10m from the lower end using methyl alcohol as the removal solvent
The coating layer of the m-width photosensitive member was removed. As a result, a uniform and good film thickness is obtained without the influence of the removing solvent splash or vapor.
An undercoat layer of 5 μm was obtained. On top of that, 97 parts by weight of methyl isobutyl ketone was mixed with 1.5 parts by weight of a bisazo pigment (chlordian blue) represented by the following structural formula (I) and 1.5 parts by weight of butyral resin (manufactured by Union Carbide: XYSG). The coating liquid for the charge generation layer prepared by dispersing the prepared product in a paint shaker for 8 hours was coated by the dip coating device so that the coating layer was not formed on the upper end 10 mm of the substrate, and dichloromethane was used as the removal solvent. The coating layer was removed in the same manner as the undercoat layer. As a result, a uniform and favorable charge generation layer having a film thickness of 0.8 μm was obtained, which was free from the influence of the removing solvent and the vapor. On top of that, 8 parts by weight of dichloromethane, 1 part by weight of a hydrazone compound (4, -diethylaminobenzaldehyde-N, N-diphenylhydrazone) of the following structural formula (II) and 1 part by weight of a polycarbonate resin (Iupilon manufactured by Mitsubishi Gas Chemical Co., Inc.) Similar to the charge generation layer, except that the coating liquid for the charge transport layer, which was prepared by stirring and dissolving a mixture of the parts with a magnetic stirrer, was 8 mm in width without the coating layer at the upper and lower ends of the substrate. The coating and coating layer were removed by the method, and a charge transport layer having a film thickness of 20 μm was provided by hot air drying at 80 ° C. for 1 hour. As a result, a uniform and good coating layer was obtained that prevented the harmful effects of the removal solvent splash and vapor. Thus, a laminated electrophotographic photosensitive member having the above was obtained.

[0052]

[Chemical 1]

[0053]

[Chemical 2]

The electrophotographic photosensitive member thus produced was used as an actual device (SF-8100, manufactured by Sharp Corporation).
In order to check the photoconductor surface potential in the developing unit, specifically, the charging property, the photoconductor surface potential (V _O ) in the dark excluding the exposure process and the photoconductor surface potential after static elimination ( V _R)
In order to check the sensitivity, the surface potential ( _VL ) of the photoconductor on the white background portion when exposed was measured.

The electrophotographic photosensitive member of this example was repeated 10,000 times and the potential was measured before and after the repetition at low temperature / low humidity (5 ° C./3).
0% RH), room temperature / normal humidity (25 ° C / 60% RH), high temperature / high humidity (35 ° C / 85% RH) It was possible to obtain an excellent electrophotographic photoreceptor.

Further, problems such as image characteristics due to actual photographing and film peeling due to poor adhesion of the photoconductor did not occur. The above results are shown in Table 1.

[0057]

[Table 1]

Example 2 The mixing ratio of the copolymerized nylon resin used in the undercoat layer of Example 1 and the non-conductive titanium oxide was 0.18 parts by weight of the copolymerized nylon resin and 17.82 of the non-conductive titanium oxide, respectively. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the weight part was used, and the electrophotographic characteristics were measured and the actual copying experiment was conducted in the same manner as in Example 1. Similar results were obtained. Table 2 shows the above measurement results.

[0059]

[Table 2]

Comparative Example 1 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the undercoat layer of Example 1 was changed to 18 parts by weight of copolymerized nylon resin and the non-conductive titanium oxide was removed. When the electrophotographic characteristics were measured by the same method as in Example 1, the charging potential (V _O ), the residual potential (V _R ) increased and the sensitivity (V _L ) deteriorated repetitively, resulting in good results. No electrophotographic photoreceptor was obtained. Table 3 shows the above measurement results.

[0061]

[Table 3]

Comparative Example 2 The mixing ratios of the copolymerized nylon resin and the non-conductive titanium oxide used in the undercoat layer of Example 1 were 3.6 parts by weight of the copolymerized nylon resin and 14.4 of the non-conductive titanium oxide, respectively. An electrophotographic photosensitive member was produced by the same method as in Example 1 except that the weight part was used, and the electrophotographic characteristics were measured by the same method as in Example 1. As in Comparative Example 1, No good electrophotographic photoreceptor was obtained. Table 4 shows the above measurement results.

[0063]

[Table 4]

Comparative Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the non-conductive titanium oxide used in the undercoat layer of Example 1 was replaced with conductive titanium oxide (Ishihara Sangyo: 500 W). Was prepared, and the electrophotographic characteristics were measured by the same method as in Example 1. As a result, the initial charging potential was insufficient and the charging potential (V _o ) was remarkably lowered due to repetition. I couldn't get it. Table 5 shows the above measurement results.

[0065]

[Table 5]

Comparative Example 4 An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the coating layer was removed without using the protective member 3 in FIGS. When removing the lower end of each of the generation layer and the charge transport layer, defects in the coating layer due to the removal solvent occurred, and problems such as spots and uneven density occurred in image evaluation.

Examples 3 and 4 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that a blade and ultrasonic waves were used instead of the brush as the coating layer removing method. All the electrophotographic photoconductors had good characteristics without defects in the coating layer and images.

Example 5 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the lower end wiping tank shown in FIGS. 4 and 5 was used as the lower end wiping tank. An electrophotographic photosensitive member having good characteristics with no defects in the coating layer and the image was obtained.

Example 6 The lower end wiping tank shown in FIGS. 8 and 9 was used as the lower end wiping tank, and the cylindrical conductive support and the lower end wiping tank were placed with their central axes displaced by 5 mm. Is
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1. As a result, an electrophotographic photosensitive member having good characteristics with no defects in the coating layer and the image was obtained.

Comparative Example 5 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 6 except that the lower end wiping tank shown in FIGS. 2 and 3 was used as the lower end wiping tank. The degree of contact of the wiping brush with the coating layer to be removed becomes uneven in the circumferential direction of the support, or the coating layer is not sufficiently protected by the protective member, so that the edge of the coating layer is The processing could not be performed sufficiently, and image defects due to solvent splash occurred.

As is apparent from the above, the laminated electrophotographic photoconductor prepared by using the method for removing the photoconductor coating layer at the lower end of the support according to the present invention has a good yield rate and uniform and good characteristics. However, the method can be easily implemented.

[0072]

As described above, according to the present invention, by providing the undercoat layer comprising the copolymerized nylon resin and the non-conductive titanium oxide between the conductive support and the charge generating layer,
It has become possible to obtain an electrophotographic photosensitive member having excellent repeated stability under any environment.

In addition, the following effects were exhibited.

1. Prevents the adverse effects of solvents when removing the photoconductor coating layer.

2. Since the protective member opens and closes concentrically, there is no need to position (center) the device.

3. Since the protective member opens and closes concentrically, it is possible to support cylindrical conductive supports with different diameters.
There is no need to replace the lower end removal device, and the equipment is simple.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminated electrophotographic photosensitive member of the present invention.

FIG. 2 is a cross-sectional view of a photoconductor coating layer removing device for a laminated electrophotographic photoconductor of the present invention.

FIG. 3 is a plan view of FIG.

FIG. 4 is a cross-sectional view of another photoconductor coating layer removing device for a laminated electrophotographic photoconductor of the present invention.

FIG. 5 is a plan view of FIG.

FIG. 6 is a cross-sectional view of another apparatus for removing a photoreceptor coating layer of a laminated electrophotographic photoreceptor of the present invention.

FIG. 7 is a plan view of FIG.

FIG. 8 is a cross-sectional view of another apparatus for removing a photoreceptor coating layer of a laminated electrophotographic photoreceptor of the present invention.

9 is a plan view of FIG. 8. FIG.

FIG. 10 shows a coating apparatus used for manufacturing the laminated electrophotographic photosensitive member of the present invention.

FIG. 11 is a cross-sectional view of a conventional laminated electrophotographic photosensitive member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2 Undercoat layer 3 Charge generation layer 4 Charge transport layer 5 Coating layer 6 Protective member 7 Blade member 8 Bottom wiping layer 9 Removal brush 10 Spring 11 Strut 12 Motor 13 Coating tank 14 Coating liquid 15 Pump 16 Auxiliary tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tomoko Otsuki, 22-22 Nagaike-cho, Abeno-ku, Osaka, Osaka Incorporated (72) Inventor Ryuhiro Morita 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture

Claims (6)

[Claims] 1. An electrophotographic photoreceptor having an undercoat layer, a charge generation layer and a charge transport layer on a conductive support, wherein the undercoat layer is a copolymerized nylon resin and titanium oxide not subjected to a conductive treatment. And a titanium oxide content of 95% or more by weight. 2. A method for manufacturing a laminated electrophotographic photosensitive member comprising a photosensitive support and a photosensitive coating layer provided on the conductive support by dip coating, wherein the photosensitive coating layer is formed on the lower end of the support after the photosensitive coating layer is formed. When removing, the protective member for protecting the non-removed layer is provided on the lower end of the support, and the coating layer on the end side of the support with respect to the protective member is removed by the presence of a removing solvent. Manufacturing method of laminated electrophotographic photoreceptor. 3. A photosensitive member for a multi-layer electrophotographic photosensitive member, comprising a wiping tank for wiping off a photosensitive member coating layer on a conductive support, comprising a shutter mechanism protecting member and a solvent removing member. Body coating layer removal device. 4. The photoconductor coating layer removing apparatus according to claim 3, wherein the protective member of the shutter mechanism has a concentric opening / closing mechanism composed of a plurality of blade members. 5. The photoconductor coating layer removing device according to claim 3, wherein at least one of the protective member of the shutter mechanism and the coating layer wiping tank is movable in the horizontal direction. 6. The photoconductor coating layer removing device according to claim 4, wherein the inner shape of the blade member which comes into contact with or approaches the conductive support is made substantially equal to the outer shape of the conductive support.