JP3186299B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to a photoreceptor using a specific polycarbonate resin as a binder resin, wherein the surface layer has high bending strength and excellent abrasion resistance. And a highly durable electrophotographic photoreceptor.

[0002]

2. Description of the Related Art In recent years, electrophotographic technology has been remarkably developed in the fields of copiers, laser beam printers, and the like because of the advantage that high speed and high printing quality can be obtained. As an electrophotographic photosensitive member used in these electrophotographic techniques, selenium and selenium
Those using an inorganic photoconductive material such as a tellurium alloy, a selenium-arsenic alloy, and cadmium sulfide are widely known. on the other hand,
Research on electrophotographic photoreceptors using organic photoconductive materials, which are inexpensive and have superior advantages in terms of manufacturability and disposability compared to electrophotographic photoreceptors using these inorganic photoconductive materials, has also been activated. . Above all, a function-separated type organic layered photoconductor in which a charge generation layer that generates charges by exposure and a charge transport layer that transports charges are laminated has sensitivity, chargeability, and its repetition stability, in terms of electrophotographic characteristics. It is excellent, and various proposals have been made and put to practical use. On the other hand,
The single-layer type organic photoreceptor has advantages in terms of manufacturability, production cost, and system of positive charging (reduction of ozone generation, uniform charging property), but electrical performance is inferior to that of the laminated type photoreceptor. There is still ample room for research and development.

[0003] Organic layered photoreceptors have been developed which have sufficient performance with respect to the electrophotographic characteristics described above. However, since the photosensitive layer is made of an organic material, the photoreceptor has high durability against mechanical external force. That is, toner, developer, paper,
Problems such as image quality defects caused by abrasion or scratches on the photoreceptor surface due to a direct load from a cleaning member and adhesion of foreign matter such as toner filming, or ozone and nitrogen oxides generated by corona discharge There is a problem such as image deletion in a high humidity environment caused by adhesion and accumulation of a low-resistance substance and paper dust generated from copy paper on the surface of the photoconductor, and regulates the life of the photoconductor. Also, with the colorization and speeding up of copiers and printers,
As the process becomes more complicated and the stress is increased, high durability is also required from these points. Furthermore, a flexible electrophotographic photosensitive member in which a photosensitive layer coating film is formed on a film such as polyethylene terephthalate on which a conductive layer is formed by a method such as vapor deposition can be processed into a belt shape and used repeatedly in a copying machine. However, there is an advantage that the degree of freedom in the shape of the hardware of the copying machine can be increased, but there is a demand that the photosensitive layer must sufficiently follow flexible movement. In order to solve these problems, various materials have been conventionally studied for the binder resin of the photosensitive layer in the electrophotographic photosensitive member. For example, various polycarbonate resins were used as the binder resin of the surface layer. A photoreceptor has been proposed (JP-A-60-1).
72044, JP-A-62-247374,
JP-A-63-148263).

[0004]

However, when a conventionally proposed resin is used as a binder resin for a photosensitive layer, an electrophotographic photosensitive member having relatively good durability can be obtained, but there is still no satisfactory photosensitive member. . In other words, the mechanical strength of the coating film formed using these resins is not always sufficient, and when used repeatedly in a copying machine for a long period of time, the surface of the photosensitive layer is abraded. The body thickness changes and the sensitivity changes. For this reason, fogging occurs in the copy, the charging potential and the copy density decrease, or scratches,
There is a problem that an image quality defect occurs due to adhesion of a foreign substance such as toner filming. In the case of a belt-shaped photoreceptor, when it is repeatedly rotated by a belt driving device in a copying machine, it cannot cope with its flexible movement, and a crack occurs in the photosensitive layer, which appears as a cracked pattern on copy image quality. The problem remained. Further, when forming the photosensitive layer, the compatibility of the charge transport material with the binder resin is important. If the compatibility is low, crystallization and precipitation of a part of the charge transport material occur, and the electrical characteristics and image quality characteristics are reduced. Has a significant effect on The present invention has been made in view of the above-described circumstances, and its purpose is to:
The coating on the surface of the photoreceptor has high bending strength, does not generate defects such as cracks in the coating even when used repeatedly as a belt-like photoreceptor, and further improves the abrasion resistance and the original electrical characteristics and An object of the present invention is to provide an electrophotographic photoreceptor having excellent image quality characteristics.

[0005]

Means for Solving the Problems As a result of intensive studies on the binder resin, the present inventors have found that by including a bisphenol-based polycarbonate resin in the photosensitive layer of the electrophotographic photosensitive member, the original electric characteristics and the like can be improved. It has been found that, even when used as a belt-shaped photoreceptor, cracks are not generated and excellent abrasion resistance is improved while achieving both image quality characteristics, and the present invention has been completed.

That is, the present invention provides an electrophotographic photosensitive member in which a photosensitive layer is coated on a conductive support, wherein the photosensitive layer contains a polycarbonate resin having a repeating unit represented by the following structural formula (I) as a binder resin. In the electrophotographic photoreceptor.

Embedded image (In the formula, X ₁ , X ₁ ′ and X ₂ may be the same or different and represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group or an arylalkyl group.)

Hereinafter, the electrophotographic photosensitive member of the present invention will be described in detail. As the conductive support in the electrophotographic photoreceptor of the present invention, aluminum, nickel, chromium, metals such as stainless steel, and aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, Examples thereof include a plastic film coated with a thin film of ITO or the like, and paper and plastic films coated or impregnated with a conductivity-imparting agent. These conductive supports are used in an appropriate shape such as a drum shape, a sheet shape, and a plate shape, but are not limited thereto. Further, if necessary, the surface of the conductive support can be subjected to various treatments within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed.

In the electrophotographic photoreceptor of the present invention, an undercoat layer is preferably provided between the conductive support and a photosensitive layer described below. This subbing layer prevents the injection of charge from the conductive support to the photosensitive layer during charging of the photosensitive layer, and acts as an adhesive layer that integrally adheres and holds the photosensitive layer to the conductive support. Alternatively, in some cases, the conductive support exhibits an action of preventing light reflection.

Materials for forming the undercoat layer include polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polyurethane resin, melamine resin, benzoguanamine resin, polyimide resin, polyethylene resin, polypropylene resin, polycarbonate resin, and acrylic resin. Resin, methacrylic resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, poly In addition to resins such as acrylic acid and polyacrylamide, zirconium chelate compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compounds, silane coupling agents, etc. Known materials can be used. These materials can be used alone or in combination of two or more. Further, titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, barium titanate,
It can be mixed with fine particles such as silicone resin. As an application method for forming the undercoat layer, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like is employed. You. The thickness of the undercoat layer is 0.
A suitable range is from 01 to 10 μm, preferably from 0.05 to 2 μm.

In the electrophotographic photoreceptor of the present invention, the photosensitive layer coated on the conductive support may have a single-layer structure or a laminated structure in which a charge generation layer and a charge transport layer are functionally separated. You may. These photosensitive layers are composed of a coating film in which a charge generation material or a charge transport material or both of them are contained in a binder resin. When the photosensitive layer has a laminated structure, the charge generating layer and the charge transport layer may be laminated in any order, but the case where the charge transport layer is the upper layer will be mainly described below.

Examples of the charge generation material contained in the charge generation layer include inorganic selenium, crystalline selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, inorganic oxides such as zinc oxide and titanium oxide. Organic pigments and dyes such as photoconductive materials, phthalocyanine-based, squarylium-based, anthrone-based, perylene-based, azo-based, anthraquinone-based, pyrene-based, pyrylium salts, and thiapyrylium salts are used. Further, as the binder resin in the charge generation layer, polyamide resin, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal resin, polyester resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin , A vinyl chloride-vinyl acetate copolymer, a silicone resin, a phenol resin, a melamine resin, a benzoguanamine resin, a urea resin, a polyurethane resin, a poly-N-vinylcarbazole resin, and the like, but a film can be formed in a normal state. The resin is not limited to these. These binder resins can be used alone or in combination of two or more.

The mixing ratio of the charge generating material to the binder resin is preferably in the range of 5: 1 to 1: 2 by volume. The charge generation layer is formed by forming the charge generation material by vacuum evaporation or by dispersing and applying the charge generation material to a binder resin in an organic solvent. Solvents used in preparing the coating solution include methanol, ethanol, n
-Propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate,
Usable are ordinary organic solvents such as methylene chloride and chloroform. These solvents can be used alone or in combination of two or more. As a method for applying the coating solution, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like is employed. The thickness of the charge generation layer is generally 0.01 to 5 μm, preferably 0.1 to 5 μm.
1 to 2.0 μm is appropriate.

The charge transporting material contained in the charge transporting layer includes p-benzoquinone, chloranil, bromoanil,
Electron withdrawing properties of quinone compounds such as anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds, cyanovinyl compounds and ethylene compounds Substances, benzidine compounds,
Triphenylamine-based compounds, arylalkane-based compounds, aryl-substituted ethylene-based compounds, butadiene-based compounds, stilbene-based compounds, anthracene-based compounds, hydrazone-based compounds, or polymers having a group consisting of these compounds in the main chain or side chain And other electron donating substances. These charge transport materials can be used alone or in combination of two or more.

Among these charge transporting materials, a benzidine compound, and a mixture of a benzidine compound and a triphenylamine compound are preferably used.
As the benzidine-based compound, a compound represented by the following general formula (II) is preferable.

Embedded image (Wherein R ₁ and R ₁ ′ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ₂ , R ₂ ′, R ₃ and R ₃ ′)
May be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a substituted amino group. M and m 'and n and n' each represent 1
Or an integer of 2. )

Among the benzidine compounds represented by the general formula (II), the present applicant has already disclosed in Japanese Patent Application Laid-Open No. 62-24737.
The following general formula (III) or general formula (I
When the compound represented by V) is used, the solubility in a solvent and the compatibility with the polycarbonate resin (I) are high, and a uniform coating film can be obtained. Therefore, a uniform interface can be formed, and an electrophotographic photoreceptor having particularly high sensitivity and excellent repetition stability is produced. Therefore, the following compounds (III) or (IV) are particularly preferable as the benzidine-based compound.

[0016]

Embedded image (In the formula, R ₄ , R ₄ ′, R ₅ and R ₅ ′ may be the same or different and represent a hydrogen atom or a methyl group.)

Embedded image (Wherein R ₆ and R ₆ ′ may be the same or different and each represents an alkyl group having 2 or more carbon atoms, and R ₇ and R ₇ ′ may be the same or different and include a hydrogen atom, an alkyl Represents a group, an alkoxy group or a substituted amino group.)

As the triphenylamine compound, a compound represented by the following general formula (V) is preferable.

Embedded image (Wherein, R ₈ and R ₉ may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group, and R ₁₀ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms. Or an aryl group having 6 to 12 carbon atoms.)

Tables 1 and 2 show specific examples of the benzidine compound, and Table 3 shows specific examples of the triphenylamine compound.

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

The benzidine compound and the triphenylamine compound are not limited to the compounds listed in Tables 1 to 3. For example, Tables 1 and 2 list, for convenience, benzidine compounds in which R ₁ and R ₁ ′, R ₂ and R ₂ ′, and R ₃ and R ₃ ′ are the same, but these are not necessarily the same. , And R ₁ ', R ₂ ' and R ₃ '
May not be the same as R ₁ , R ₂ and R ₃ . The benzidine compound and the triphenylamine compound may be used alone or in combination of two or more.

As the binder resin in the charge transport layer, it is desirable to use a polycarbonate resin whose repeating unit is mainly composed of the polycarbonate resin represented by the structural formula (I).

Embedded image (Wherein X ₁ , X ₁ ′ and X ₂ are the same as above)

X ₁ , X ₁ 'and X _{2 in the} general formula (I)
Can be exemplified by the following substituents.
For example, as a halogen atom, a fluorine atom, a chlorine atom,
A bromine atom, an iodine atom and the like can be mentioned. The alkyl group may be linear or branched, a methyl group,
Examples include an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. Examples of the aryl group include a phenyl group and a naphthyl group. Arylalkyl groups include benzyl,
Phenethyl group, phenylpropyl group, phenylbutyl group, phenylpentyl group, phenylhexyl group, naphthylmethyl group, and the like.Alkyl groups may be branched, and in alkyl groups having 2 or more carbon atoms. In the formula, the phenyl group can be substituted not only at the terminal carbon but also at another carbon. Further, these aryl groups include
One or more substituents such as the above-mentioned halogen atoms and alkyl groups may be substituted.

As the polycarbonate resin (I), those having a viscosity average molecular weight in the range of 10,000 to 200,000 can be used. When the polycarbonate resin (I) having a relatively uniform molecular weight distribution is used, it is preferably in the range of 20,000 to 100,000. If the viscosity average molecular weight is less than 20,000, the required viscosity cannot be obtained because the viscosity of the coating solution is low. On the other hand, if the viscosity average molecular weight is larger than 100,000, on the other hand, there is a problem that the viscosity of the coating solution is high and it is difficult to control the required film thickness. However, this point indicates that the viscosity average molecular weight is 10,000-20.
Since it is improved by appropriately mixing and using the polycarbonate resin (I) in the range of 10,000, the polycarbonate resin (I) having a significantly different viscosity average molecular weight may be mixed and used. In addition, as long as the function and effect of the polycarbonate resin (I) are not impaired, a resin mixed with or copolymerized with a different kind of polycarbonate resin can be used.

In the present invention, examples of the polycarbonate resin which can be suitably used include those represented by the structural formulas having the following repeating units. These polycarbonate resins are 1,3-bis [β- (4-
[Hydroxyphenyl) -β-propyl] benzene (hereinafter, referred to as bisphenol compound (1)) or a derivative thereof with phosgene.

[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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The composition ratio of the charge transporting material to the binder resin is suitably in the range of 10:90 to 70:30 by weight.
The range of 0:70 to 60:40 is preferred. Solvents used when forming the charge transport layer include benzene, toluene, aromatic hydrocarbons such as xylene, halogenated aromatic hydrocarbons such as monochlorobenzene, acetone, ketones such as methyl ethyl ketone, methylene chloride, Halogenated aliphatic hydrocarbons such as chloroform and ethylene chloride,
Examples include ordinary organic solvents such as cyclic or linear ethers such as tetrahydrofuran and ethyl ether. These solvents can be used alone or in combination of two or more. In addition, as a method of applying the coating solution, an ordinary method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method is employed. The thickness of the charge transport layer is generally 5 to 50 μm, preferably 10 to 30 μm.
m is appropriate.

In the photoreceptor of the present invention, an antioxidant, a light stabilizer, and a heat stabilizer are contained in the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, light or heat generated in a copying machine. Additives such as stabilizers can be added. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirocoumarone, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like. Examples of light stabilizers include benzophenone, benzotriazole, dithiocarbamate,
Derivatives such as tetramethylpiperidine are exemplified.

When the photosensitive layer of the electrophotographic photosensitive member of the present invention has a single-layer structure, the same charge generating material and charge transporting material as those in the case where the photosensitive layer has a laminated structure are used. The polycarbonate resin described for the charge transport layer is used. The polycarbonate resin may contain less than 50% by weight of the binder resin exemplified in the charge generation layer. Further, if necessary, additives such as antioxidants, light stabilizers and heat stabilizers described above are contained in the photosensitive layer. In the single-layer type photoreceptor, the composition ratio of the charge generating material is 0.1 to 20% by weight, preferably 0.5 to 5% by weight based on the total amount of the charge transporting material and the binder resin.
Is appropriate. The composition ratio of the charge transport material to the binder resin is preferably in the range of 60:40 to 30:70 by weight. To coat the photosensitive layer on the conductive support, after uniformly dissolving or dispersing the above components in a solvent as exemplified in the case of forming the charge transport layer, by the usual coating method described above. What is necessary is just to apply and dry. The thickness of the single-layer type photosensitive layer is generally 5 to 50 μm, preferably 10 to 25 μm.
Is appropriate.

The polycarbonate resin (I) used as the binder resin is desirably contained on the outermost surface of the photosensitive layer. That is, when the photosensitive layer of the electrophotographic photosensitive member has a single layer structure, as described above, the polycarbonate resin (I) is contained in the photosensitive layer. On the other hand, when the photosensitive layer has a laminated structure, the polycarbonate resin (I) is preferably contained in the charge transport layer. However, when the charge generation layer is coated on the upper layer, the polycarbonate resin (I) is added to the charge generation layer. The binder resin described above for the charge generation layer may be used for the charge transport layer. The electrophotographic photoreceptor of the present invention has a single-layer photoreceptor,
In the case of a laminated photoreceptor, a protective layer may be formed on the charge transport layer.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In the examples and comparative examples, “parts” means parts by weight. First, a typical synthesis example of the polycarbonate resin (I) used as a binder resin of the photosensitive layer in the electrophotographic photosensitive member of the present invention will be described.

Synthesis Example 1 0.2 mol of bisphenol compound (1), 400 ml of 4.7% aqueous sodium hydroxide solution and methylene chloride 35
0 ml was charged into a 2 liter reaction vessel, and phosgene was blown at a rate of 400 ml / min for 15 minutes with vigorous stirring. Keep the reaction temperature at 15 ° C, and add 13.7%
40 ml of an aqueous sodium hydroxide solution, 0.2 g of trimethylbenzylammonium chloride and 0.3 ml of triethylamine were added, and stirring was continued at 23 ° C. for 1 hour to carry out a polycondensation reaction. Thereafter, the reaction product was diluted with 400 ml of methylene chloride, and 1 liter of water, 0.5N of 0.01 N hydrochloric acid were added.
and 1 l of water. The obtained organic layer was added to 5 l of methanol to precipitate a white polymer, which was separated by filtration.
After drying at 100 ° C. for 12 hours, about 55 g of the above-mentioned polycarbonate resin (1) (viscosity average molecular weight Mv; 43,000) was obtained.

Synthesis Example 2 Bisphenol compound (1) was converted to 1,3-bis [β- (3
-Methyl-4-hydroxyphenyl) -β-propyl]
About 50 g of the polycarbonate resin (8) (Mv; 46,000) was obtained in the same manner as in Synthesis Example 1 except that benzene was used. Synthesis Example 3 Bisphenol compound (1) was converted to 1,3-bis [β- (3
-Methyl-4-hydroxyphenyl) -β-propyl]
Except having replaced with -5-ethylbenzene, it carried out similarly to the synthesis example 1, and said polycarbonate resin (10) (Mv; 4).
2,000) was obtained. Synthesis Example 4 Bisphenol compound (1) was converted to 1,3-bis [β- (3
-Methyl-4-hydroxyphenyl) -β-propyl]
Except having replaced with -5-phenylbenzene, it carried out similarly to the synthesis example 1, and said polycarbonate resin (17) (Mv; 4).
7,000) was obtained.

Example 1 An aluminum thin film of about 500 angstroms was formed on a polyethylene terephthalate film surface by vacuum evaporation. A coating solution composed of 10 parts of a polyamide resin (Lacamide 5003; manufactured by Dainippon Ink and Chemicals, Inc.), 150 parts of methyl alcohol and 40 parts of water is applied on the substrate, and heated and dried at 120 ° C. for 10 minutes to form a film having a thickness of 1 μm.
Was formed. Next, a mixture consisting of 90 parts of trigonal selenium (manufactured by Xerox Corporation, USA), 10 parts of polyvinyl butyral resin (S-LEC BM-S; manufactured by Sekisui Chemical Co., Ltd.) and 300 parts of n-butyl alcohol is dispersed, and the resulting dispersion is obtained. A solution diluted in a ratio of 2 parts of n-butyl alcohol to 1 part was applied onto the undercoat layer, and dried by heating at 120 ° C. for 10 minutes to form a 0.2 μm-thick charge generating layer. Next, 8 parts of a benzidine-based compound (Compound No. II-27) as a charge transport material and 12 parts of the polycarbonate resin (1) obtained in Synthesis Example 1 were dissolved in 85 parts of monochlorobenzene, and the obtained coating solution was obtained. On an aluminum substrate on which a charge generation layer is formed, and 13
The resultant was dried by heating at 5 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm. Thus, an electrophotographic photoreceptor containing the polycarbonate resin (1) in the charge transport layer was produced.

Example 2 Compound No. 1 was used as a charge transport material. In place of compound II-27, compound No. A photoconductor was prepared by the same way as that of Example 1 except that the benzidine compound of II-15 was used. Example 3 10 parts of a triphenylamine compound (Compound No. III-6) was used as the charge transport material instead of the benzidine compound, and the amount of the polycarbonate resin (1) used was 10 parts as the binder resin of the charge transport layer. A photoconductor was prepared in the same manner as in Example 1, except that

Example 4 A photoconductor was prepared by the same way as that of Example 3 except that a hydrazone compound represented by the following general formula (VI) was used instead of the triphenylamine compound as the charge transporting material.

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Example 5 A photoconductor was prepared by the same way as that of Example 3 except that a stilbene compound represented by the following formula (VII) was used instead of the triphenylamine compound as the charge transporting material.

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Examples 6 to 10 All of Examples 1 to 5 except that the polycarbonate resin (8) obtained in Synthesis Example 2 was used in place of the polycarbonate resin (1) as the binder resin for the charge transport layer. A photoreceptor was produced in the same manner as described above. Examples 11 to 13 In the same manner as in Examples 1 to 3, except that the polycarbonate resin (10) obtained in Synthesis Example 3 was used instead of the polycarbonate resin (1) as the binder resin for the charge transport layer. To produce a photoreceptor. Examples 14 to 16 The same procedures as in Examples 1 to 3 were carried out except that the polycarbonate resin (17) obtained in Synthesis Example 4 was used in place of the polycarbonate resin (1) as the binder resin for the charge transport layer. To produce a photoreceptor.

Comparative Examples 1 to 5 In forming the charge transport layer, a polycarbonate resin (Mv; 3) having a repeating unit represented by the following structural formula (VIII) instead of the polycarbonate resin (1) as the binder resin
000) and methylene chloride was used in place of monochlorobenzene as a coating solvent.
To 5, a photoreceptor was prepared.

Embedded image

Comparative Examples 6 to 8 As the binder resin for the charge transport layer, except that a polycarbonate resin (Mv; 32,000) having a repeating unit represented by the following structural formula (IX) was used instead of the polycarbonate resin (1). Were prepared in the same manner as in Examples 1 to 3.

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Each of the electrophotographic photosensitive members produced as described above was subjected to a repeated bending test up to 50,000 times using a film bending tester (manufactured by Nissin Kagaku). In addition, a copying machine having a belt rotation driving device (Viv
ace800; manufactured by Fuji Xerox Co., Ltd.), the belt tension was tripled, and each electrophotographic photosensitive member was mounted.
A copy running test was performed on up to 80,000 sheets without feeding the paper, that is, without transferring to paper, and the image quality was evaluated every 2,000 copies. In addition, the state (coating property) of the coating film on the surface was visually observed during the production of each photoconductor, and the results are shown in Table 4 together with the above evaluation.

[0046]

[Table 4] *: In each comparative example, the number of bendings at which cracks occurred is shown. #: In each comparative example, it indicates the number of copies in which a fine crack has occurred and an image defect has occurred.

Examples 17 to 22 Drum type photosensitive members were produced under the same conditions as in Examples 1 to 3 and Examples 6 to 8. Each electrophotographic photosensitive member is transferred to a copying machine (Vi
base500 (manufactured by Fuji Xerox Co., Ltd.) was mounted on a remodeled machine in which the contact pressure of the cleaning blade to the photoconductor was tripled the normal value, and a copy running test was performed up to 30,000 times for copying, and the wear amount of the photosensitive layer was measured. did. At the same time, image quality defects after 30,000 copies were evaluated. Table 5 shows the results. Comparative Examples 9 to 14 Drum type photoreceptors were produced under the same conditions as Comparative Examples 1 to 3 and Comparative Examples 6 to 8. In the same manner as in Example 17, the wear amount of each electrophotographic photosensitive member was measured and the image quality defect was evaluated. Table 5 shows the results.

[0048]

[Table 5]

Example 23 10 parts of a zirconium compound (Orgatic ZC540; manufactured by Matsumoto Pharmaceutical Co., Ltd.) and a silane compound (A111)
0; manufactured by Nippon Unicar Co., Ltd.), a solution consisting of 1 part of i-propanol and 20 parts of butanol was applied to a drum-shaped aluminum substrate by a dip coating method,
For 10 minutes to form an undercoat layer having a thickness of 0.1 μm. Next, 10 parts of a benzidine compound (Compound No. II-27) as a charge transporting material and 12 parts of the polycarbonate resin (1) obtained in Synthesis Example 1 as a binder resin were mixed with 20 parts of monochlorobenzene and 80 parts of tetrahydrofuran. Dissolved in the solvent. Next, 1 part of oxytitanyl phthalocyanine as a charge generating material was added, and the mixture was treated with glass beads by a sand mill for 1 hour and dispersed. Then, the obtained coating solution was applied on the undercoat layer by a dip coating method. The film was dried by heating at 1 ° C. for 1 hour to form a single-layer photosensitive layer having a thickness of 25 μm. Thus, an electrophotographic photosensitive member containing the polycarbonate resin (1) in the single-layer type photosensitive layer was produced.

Example 24 A photoconductor was prepared in the same manner as in Example 23, except that the polycarbonate resin (8) obtained in Synthesis Example 2 was used instead of the polycarbonate resin (1) as the binder resin. .

Comparative Examples 15 and 16 As the binder resin, the repeating units represented by the structural formulas (VIII) and (IX) were used in place of the polycarbonate resin (1).
A photoconductor was prepared in the same manner as in Example 23, except for using the polycarbonate resin represented by.

Examples 23 and 24 and Comparative Examples 15 and 16
Each electrophotographic photoreceptor prepared in the above was mounted on a modified machine of a laser beam printer (XP-11; manufactured by Fuji Xerox Co., Ltd.) and equivalent to 30,000 copies without paper feed, that is, without transfer to paper A print running test was performed to measure the amount of wear of the photosensitive layer. At the same time, the image quality defect of the copy obtained was evaluated. Table 6 shows the results.

[0053]

[Table 6]

[0054]

According to the present invention, since the polycarbonate resin having the repeating unit represented by the structural formula (I) is used as the binder resin for the photosensitive layer, the coating film of the formed photosensitive layer is extremely high. Has bending strength. Therefore, when the electrophotographic photoreceptor of the present invention is used in the form of a belt, even if it is repeatedly used for a long time in a copying machine, it does not cause cracks or the like in the photosensitive layer and has high durability. ing. The drum-type photoreceptor also exhibits high abrasion resistance, so that a copy image with excellent image quality can be obtained over a long period of time even when used repeatedly in a copying machine for a long time. As is clear from the above tables, the electrophotographic photoreceptor of the present invention maintains excellent repetition stability and has excellent abrasion resistance.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomozumi Uesaka 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. ) Inventor Fumio Kojima 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (56) References JP-A-4-291348 (JP, A) JP-A-2-25459 (JP, A) JP-A-2- 254458 (JP, A) JP-A-2-189550 (JP, A) JP-A-2-124576 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5 / 05,5 / 06

Claims (7)

(57) [Claims] 1. An electrophotographic photosensitive member in which a photosensitive layer is coated on a conductive support, wherein the photosensitive layer contains a polycarbonate resin having a repeating unit represented by the following structural formula (I) as a binder resin. Electrophotographic photoreceptor. Embedded image (In the formula, X ₁ , X ₁ ′ and X ₂ may be the same or different and represent a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group or an arylalkyl group.) 2. The electrophotographic photosensitive member according to claim 1, wherein a benzidine compound represented by the following general formula (II) is contained in the photosensitive layer as a charge transporting material. Embedded image (Wherein R ₁ and R ₁ ′ may be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ₂ , R ₂ ′, R ₃ and R ₃ ′)
May be the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a substituted amino group. M and m 'and n and n' each represent 1
Or an integer of 2. ) 3. The electrophotographic photoreceptor according to claim 2, wherein a mixture of said benzidine compound and triphenylamine compound is used as a charge transport material. 4. The electrophotographic photosensitive member according to claim 1, wherein said polycarbonate resin is contained on the outermost surface of a photosensitive layer. 5. The photosensitive layer has a single-layer structure.
The electrophotographic photosensitive member according to any one of the above. 6. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer has a structure in which a charge generation layer and a charge transport layer are sequentially laminated, and the polycarbonate resin is contained in the charge transport layer. . 7. The electrophotographic photosensitive member according to claim 1, wherein an undercoat layer is provided between the conductive support and the photosensitive layer.