JPH07120942A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic photoreceptor hardly causing the scuffing of the surface of the photosensitive layer, ensuring satisfactory compatibility with an electric charge transferring material and having improved wear resistance and superior repetition stability. CONSTITUTION:An electric conductive substrate is coated with a photosensitive layer contg. polycarbonate resin contg. repeating structural units represented by the general formula as a bonding resin to obtain the objective electrophotographic photoreceptor. In the formula, each of X1 and X2 is H, an alkyl, aryl, aryl substd. alkyl or cyclohexyl, X1 and X2 may bond to each other to form an atomic group required to form a carbon ring or a lactone ring, X3 is butyl, X4 is H or methyl and (h) is 1 or 2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
More specifically, it relates to an electrophotographic photoreceptor using a specific modified polycarbonate resin as a binder resin.

[0002]

2. Description of the Related Art Conventionally, electrophotographic photoreceptors have been remarkably widely applied in the fields of copying machines, laser beam printers, etc., because they have the advantages of high speed and high printing quality. As electrophotographic photoreceptors used in these electrophotographic techniques, those using inorganic photoconductive materials such as selenium, selenium-tellurium alloys, selenium-arsenic alloys, and cadmium sulfide have been widely known. On the other hand, as compared with electrophotographic photoreceptors using these inorganic photoconductive materials, research on electrophotographic photoreceptors using organic photoconductive materials, which are cheaper and have excellent advantages in terms of manufacturability and disposal, has also been activated. There is. Among them, the function-separated organic laminate type photoreceptor in which a charge generation layer that generates a charge upon exposure and a charge transport layer that transports a charge is laminated is preferable in terms of electrophotographic characteristics such as sensitivity, chargeability and repeated stability thereof. Since it is excellent, various proposals have been made and put into practical use. On the other hand, at present, single-layer type organic photoconductors have the system advantages (reduction of ozone generation, uniform chargeability) in terms of manufacturability, production cost, and positive chargeability, but on the other hand, electrical performance Has a problem that is inferior to the laminated type photoreceptor,
There is still plenty of room for research and development.

As described above, an organic laminated type photoreceptor has been developed which has sufficient performance with respect to the above electrophotographic characteristics. However, since the photosensitive layer is made of an organic material, it is resistant to mechanical external force. Durability, that is, there is a problem of abrasion and scratches on the surface of the photoconductor due to direct load from toner, developer, paper, cleaning member, etc., and image quality defects due to foreign matter such as toner filming. Image in a high humidity environment caused by a problem that occurs, or low resistance substances such as ozone and nitrogen oxides generated by corona discharge, and paper dust generated from copy paper that adheres and accumulates on the photoconductor surface. There are problems such as flow,
These problems limit photoreceptor life. Further, as the color and speed of copying machines and printers have increased, the process has become more complicated and the stress has increased. From these points as well, higher durability is required.

Various materials have been studied for the binder resin of the photosensitive layer in these electrophotographic photoreceptors. For example, various modified polycarbonate resins have been proposed as the binder resin of the photoreceptor surface layer. (JP-A-60-172044, JP-A-61-6203)
9, JP-A-61-137157, JP-A-62-24.
7374, JP-A-63-148263, JP-A-1-
269942, JP-A-1-269943, JP-A-1
-273046 and JP-A-1-125548).

[0005]

However, when the conventionally proposed resin is used as the binder resin for the photosensitive layer, an electrophotographic photosensitive member having relatively good durability can be obtained, but it is still not satisfactory. Absent. That is, the mechanical strength of the coating film formed by using these resins is not always sufficient, and when repeatedly used in a copying machine for a long period of time, the surface of the photosensitive layer is abraded, resulting in a photoreceptor. Since the thickness of the film becomes thin and the sensitivity changes accordingly, there are problems that the charging potential is lowered, fog occurs in the copy, or the copy density is lowered. Further, the surface of the photoconductor is not evenly scraped and becomes scratched, and on the other hand, there arises a problem that an image quality defect occurs due to adhesion of foreign matter such as toner filming. Furthermore, when the photosensitive layer is formed, the compatibility of the charge transport material with the binder resin is also important, and if the compatibility of the binder resin is low, some charge transport materials may cause crystallization, precipitation, etc. Although it is known that the properties and the image quality properties are significantly affected, some of the resins proposed hitherto are insufficient in compatibility. The present invention has been made in view of the circumstances as described above, and an object of the present invention is to prevent scratches on the surface of the photosensitive layer, good compatibility with the charge transport material, and improved abrasion resistance. Another object of the present invention is to provide an electrophotographic photosensitive member that can maintain original excellent electrical characteristics and excellent image quality.

[0006]

Means for Solving the Problems As a result of intensive studies on the material of the photosensitive layer, the present inventors have found that a special polycarbonate resin is contained as a binder resin to achieve both electric characteristics and image quality. It has been found that a further improved abrasion resistance can be achieved, and the present invention has been completed. That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, the photosensitive layer containing a polycarbonate resin containing a repeating structural unit represented by the following general formula (I) as a binder resin. It is characterized by doing.

[Chemical 5] (In the formula, each of X ₁ and X ₂ represents a hydrogen atom, an alkyl group, an aryl group or an aryl-substituted alkyl group, or a cyclohexyl group, or X ₁ and X ₂ together form an alicyclic carbocycle or lactone. Represents an atomic group necessary for forming a ring, X ₃ represents a butyl group, X ₄ represents a hydrogen atom or a methyl group, and h represents an integer of 1 or 2.)

The electrophotographic photoreceptor of the present invention will be described in more detail below. The drawings are schematic cross-sectional views of an example of the electrophotographic photoreceptor of the present invention. FIG. 1 shows a case where the photosensitive layer has a single layer structure, and FIG. 2 shows a case where the photosensitive layer has a laminated structure. In FIG. 1, an undercoat layer 5 is provided on a conductive support 4, and a photoconductive layer 1 is formed thereon.
In FIG. 2, an undercoat layer 5 is provided on a conductive support 4, and a charge generation layer 2 and a charge transport layer 3 are formed thereon.

Examples of the conductive support include metals such as aluminum, nickel, chromium and stainless steel, as well as aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide and IT.
Examples thereof include a plastic film provided with a thin film of O or the like, or paper and a plastic film coated with or impregnated with a conductivity-imparting agent. These conductive supports are used in a suitable 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 present invention, it is preferable to provide an undercoat layer between the conductive support and the photosensitive layer. As a material used for the undercoat layer, a known material can be used.
For example, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polyurethane resin, melamine resin, benzoguanamine resin, polyimide resin, polyethylene resin, polypropylene resin, polycarbonate resin, acrylic resin, methacrylic resin, vinylidene chloride resin, polyvinyl acetal resin , Vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin,
Examples thereof include polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compounds, titanyl chelate compounds, titanyl alkoxide compounds, organic titanyl compounds and silane coupling agents. These materials may be used alone or in combination of two or more. further,
It can be mixed with fine particles such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, barium titanate, and silicone resin. As a coating method for forming the subbing layer, there are commonly used methods such as a blade coating method, a Meyer 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. Adopted. The thickness of the undercoat layer is 0.01 to 10 μm.
m, preferably 0.05-2 μm.

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

The charge generation layer can be formed by vacuum-depositing the charge generation material, or can be formed by dispersing the charge generation material in a binder resin in an organic solvent and applying it. The charge generating material used in the present invention includes amorphous selenium, crystalline selenium-tellurium alloy,
Selenium-arsenic alloys, other selenium compounds and selenium alloys, inorganic photoconductive materials such as zinc oxide and titanium oxide,
Examples include organic pigments and dyes such as phthalocyanine-based, squarylium-based, anthanthrone-based, perylene-based, azo-based, anthraquinone-based, pyrene-based, pyrylium salts and thiapyrylium salts. 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, Examples thereof include vinyl chloride-vinyl acetate copolymer, silicone resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, polyurethane resin, poly-N-vinylcarbazole resin, and the like, which can form a film in a normal state. However, these are not limited. These binder resins may be used alone or in combination of two or more. The mixing ratio of the charge generating material and the binder resin is a volume ratio,
The range of 5: 1 to 1: 2 is preferable.

Solvents used in preparing the coating solution include methanol, ethanol, n-propanol, and n.
-Butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, chlorobenzene, methyl acetate,
Commonly used organic solvents such as n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride and chloroform may be used alone or in combination of two or more. As a coating method of the coating liquid, a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method,
A commonly used method such as an air knife coating method or a curtain coating method can be used. The thickness of the charge generation layer is generally set in the range of 0.01 to 5 μm, preferably 0.1 to 2.0 μm.

The charge transport material contained in the charge transport layer includes p-benzoquinone, chloranil, bromoanil,
Electron withdrawing substances such as quinone compounds such as anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, saxington compounds, benzophenone compounds, cyanovinyl compounds, ethylene compounds , Triarylamine-based compounds, benzidine-based compounds, arylalkane-based compounds, aryl-substituted ethylene-based compounds, stilbene-based compounds, anthracene-based compounds, hydrazone-based compounds, or polymers having groups of these compounds in the main chain or side chain Electron-donating substances such as These charge transport materials can be used alone or in combination of two or more. Among these charge transport materials, benzidine compounds, triarylamine compounds, and mixtures of these compounds are particularly preferably used.

The benzidine compound is preferably a compound represented by the following general formula (III).

[Chemical 6] (In the formula, R ₁ and R ₁ ′ each represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom,
R ₂ , R ₂ ′, R ₃ and R ₃ ′ each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a substituted amino group, and m, m ′, n and n ′ are 1 or 2 respectively. Means an integer. )

Among the benzidine compounds represented by the above general formula (III), the following general formula (III-i) or general formula (III-i) disclosed in JP-A-62-247374 is disclosed.
Preference is given to using the compounds indicated under i).

[Chemical 7] (In the formula, R ₅ , R ₅ ′, R ₆ and R ₆ ′ may be the same or different and each represents a hydrogen atom or a methyl group.)

[0016]

[Chemical 8] (In the formula, R ₇ and R ₇ ′ each represent an alkyl group having 2 or more carbon atoms, and R ₈ and R ₈ ′ each represent a hydrogen atom, an alkyl group, an alkoxy group or a substituted amino group.) Formula (III-i) or general formula (III-i
When the compound represented by ii) is used, solubility in a solvent and compatibility with the polycarbonate resin are high, and a uniform coating film can be obtained. As a result, a uniform interface can be formed, and it becomes possible to manufacture an electrophotographic photosensitive member having particularly high sensitivity and excellent repeated stability.

Further, the triarylamine compound is preferably a compound represented by the following general formula (IV).

[Chemical 9] (In the formula, R ₄ represents a hydrogen atom or a methyl group, and Ar 4
₁ and Ar ₂ each represent a halogen atom, an alkyl group, an aryl group which may have an alkoxy group or a substituted amino group, or a thienyl group, and k is 1 or 2
Means an integer of. )

Specific examples of the benzidine compound are listed in Tables 1 and 2 and specific examples of the triarylamine compound are listed in Tables 3 to 6, respectively.

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

[Table 5]

[Table 6]

In the present invention, the benzidine compound and the triarylamine compound are not limited to the compounds listed in Tables 1 to 6. For example, in Tables 1 and 2, R ₁ and R ₁ ′ are shown for convenience. , R ₂ and R ₂ ′, R ₃ and R
_{Although the} 3'-listed benzidine compounds are the same, these may not necessarily be the same as each other.
The substitution positions of R ₁ ′, R ₂ ′ and R ₃ ′ are also R ₁ and R ₂
And R ₃ need not be the same. Further, the benzidine-based compound and the triarylamine-based compound may be used alone or as a mixture of two or more thereof.

As the binder resin in the charge transport layer, a polycarbonate resin containing a repeating structural unit represented by the following general formula (I) is used. Among them, a repeating structural unit represented by the general formula (II) is used. Is preferred.

[Chemical 10] (In the formula, X _{1 to} X ₄ and h are the same as above.)

[Chemical 11] (In the formula, t-Bu represents a tert-butyl group, X ₁ ,
X ₂ and h are the same as above. )

The following substituents can be exemplified as X ₁ and X ₂ in the general formula (I). For example, the alkyl group may be linear or branched, and a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group,
Examples include octadecyl group. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and the like. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aryl-substituted alkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylbutyl group, a phenylpentyl group, a phenylhexyl group, a biphenylmethyl group, and a naphthylmethyl group, but the alkyl group is a branched chain. Alternatively, in the aryl-substituted alkyl group in which the alkyl moiety has 2 or more carbon atoms, the aryl group can be substituted not only with the terminal carbon but also with another carbon. Further, the aryl moiety of the aryl group and the aryl-substituted alkyl group may be substituted with one or more substituents such as the halogen atom and the alkyl group described above. Further, as an alicyclic carbon ring formed together with the carbon atom to which X ₁ and X ₂ are bonded, a divalent group such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclooctylidene group, etc. The alicyclic compound residue of is mentioned. The lactone ring which is also formed together with the carbon atom includes divalent residues such as butyrolactone, valerolactone, caprolactone and caprinolactone. X ₃ represents a butyl group, but may be linear or branched, and specifically, n-butyl group, i
Examples thereof include so-butyl group, sec-butyl group and tert-butyl group. X ₄ represents a hydrogen atom or a methyl group.

In the present invention, as the polycarbonate resin containing the repeating structural unit represented by the general formula (I), those having a viscosity average molecular weight in the range of 10,000 to 200,000 can be used, and the molecular weight distribution is relatively high. If the polycarbonate resin is uniform, it is preferably in the range of 15,000 to 100,000. When the viscosity average molecular weight is less than 10,000,
The viscosity of the coating solution is low, the required film thickness cannot be obtained, and the film thickness becomes uneven when dip coating. If it is more than 100,000, on the contrary, there is a problem that the viscosity of the coating solution is too high and it becomes difficult to control the required film thickness. However, these problems are ameliorated by appropriately mixing and using a plurality of polycarbonate resins having a viscosity average molecular weight of 10,000 to 200,000. Therefore, in the present invention, the above-mentioned general formula () having different viscosity average molecular weights is used. You may mix and use the polycarbonate resin which consists of a repeating structural unit shown by I). Further, it is also possible to use a mixture of different polycarbonate resins or a copolymer thereof, as long as the functions and effects of the polycarbonate resin are not impaired.

Next, typical examples of the polycarbonate resin used in the present invention will be exemplified by the repeating structural unit represented by the general formula (I).

[Chemical 12]

[0028]

[Chemical 13]

These polycarbonate resins are prepared by using a phenolic compound represented by the following general formula (I '),
It can be produced by a conventional synthetic method of reacting with phosgene. This synthetic method is described in detail in JP-A-62-39624, JP-A-1-87621, etc., and some of the polycarbonates are described in G. Kaemp.
Kunst presented by f, D. Freitag & G. Fengler
stoffe German Plastics, 1992, Vol.82, No.5, P385
Physical properties are listed in ~ 390.

[Chemical 14] (In the formula, X _{1 to} X ₄ and h are the same as above.)
When two or more phenolic compounds are used for copolymerization, a method in which two or more phenolic compounds are first reacted with phosgene at the same time, one phenolic compound is reacted, and a time is allowed There are a method of adding another phenolic compound and reacting it, a method of further mixing and reacting oligomers respectively reacted with phosgene, and the like, and any of these can be selected.

In the charge transport layer of the electrophotographic photosensitive member of the present invention, the composition ratio of the charge transport material to the binder resin is 10:90 to 70/30 by weight, and 3 is appropriate.
The range of 0:70 to 60/40 is particularly preferable. Further, as the solvent used when the charge transport layer is provided, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated aromatic hydrocarbons such as chlorobenzene, methylene chloride and chloroform, Usual organic solvents such as halogenated aliphatic hydrocarbons such as ethylene chloride, cyclic or linear ethers such as tetrahydrofuran and ethyl ether, and the like can be mentioned. These solvents can be used alone or in combination of two or more. Further, as a coating method, a usual method such as a blade coating method, a Mayer 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 can be used. The thickness of the charge transport layer used in the present invention is generally 5 to 50 μm,
It is preferably set to 10 to 35 μm.

Further, in order to prevent deterioration of the photoreceptor due to ozone or oxidizing gas generated in the copying machine, or light or heat, an antioxidant, a light stabilizer, a heat stabilizer, etc. are contained in the photosensitive layer. Additives can be added. For example, as antioxidants, hindered phenols, hindered amines,
Examples thereof include paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroindanone and their derivatives, organic sulfur compounds and organic phosphorus compounds. Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.

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 transport material as those used when the photosensitive layer has a laminated structure are used. As the above, the polycarbonate described in 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 the above-mentioned antioxidants, light stabilizers and heat stabilizers can be 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. The composition ratio of the charge transport layer material and the binder resin is preferably in the range of 60:40 to 30:70 by weight. To coat the conductive support with the photosensitive layer,
After the above-mentioned constituents are uniformly dissolved or dispersed in a solvent as exemplified when forming the charge transport layer, it may be applied by the above-mentioned usual application method and dried. The thickness of the single-layer type photoreceptor is generally 5 to 50 μm, preferably 10 to 25 μm. In the electrophotographic photoreceptor of the present invention, on the photosensitive layer in the case of a single-layer type photoreceptor,
In the case of a laminated type photoreceptor, a protective layer may be formed on the charge transport layer.

[0033]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. In addition, "part" in an Example and a comparative example means a weight part. Example 1 A zirconium compound (trade name: Organix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) on a drum-shaped aluminum substrate.
A solution consisting of 10 parts and 1 part of a silane compound (trade name: A1110, manufactured by Nippon Unicar Co., Ltd.) and 40 parts of i-propanol and 20 parts of butanol was applied by a dip coating method, and dried by heating at 150 ° C. for 10 minutes to form a film. An undercoat layer having a thickness of 0.1 μm was formed. Next, 90 parts of trigonal selenium (manufactured by Xerox Co., USA), 10 parts of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.), n
A mixture of 300 parts of butyl alcohol was dispersed, and 1 part of the resulting dispersion was diluted with 2 parts of n-butyl alcohol to apply the coating liquid on the undercoat layer. After heating and drying for a minute, the film thickness becomes 0.
A 2 μm charge generation layer was formed. Next, as an example of the charge transport material, the exemplified compound No. Polycarbonate resin 1 comprising 8 parts of a benzidine compound represented by III-27 and a repeating structural unit represented by I-13 as a binder resin 1
2 parts (viscosity average molecular weight Mv: 20,500) were dissolved in a mixed solvent of 20 parts of monochlorobenzene and 80 parts of tetrahydrofuran. The obtained coating liquid is applied onto the above charge generation layer by a dip coating method, and the coating liquid is applied at 135 ° C. for 60 hours.
It was heated and dried for a minute to form a charge transport layer having a thickness of about 26 μm, and the state of the coating film was visually observed. The electrophotographic photosensitive member manufactured as described above is used as a copying machine (Viverse).
(500, manufactured by Fuji Xerox Co., Ltd.) was mounted on a modified machine in which the ground pressure for the photoconductor was tripled from the normal, and a copy running test up to 30,000 sheets was carried out. The amount of wear was evaluated. The results are shown in Table 7.

Example 2 As the charge transport material of the charge transport layer in Example 1, the exemplified compound No. Exemplified Compound No. in place of the benzidine compound of III-27. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the benzidine compound of III-15 was used, and the same test was conducted. The results are shown in Table 7. Example 3 As the charge transport material of the charge transport layer in Example 1, Exemplified Compound No. Exemplified Compound No. in place of the benzidine compound of III-27. An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 8 parts by weight of the triarylamine compound of IV-28 was used, and the same test was conducted. The results are shown in Table 7. Example 4 Instead of the polycarbonate resin (I-13) in Example 1, a polycarbonate resin having a repeating structural unit represented by I-17 (viscosity average molecular weight Mv: 18,0) was used.
00) and the charge transport material of the charge transport layer, exemplified compound No. Exemplified Compound No. in place of the benzidine compound of III-27. An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the IV-50 triarylamine compound was used, and the same test was conducted. The results are shown in Table 7. Example 5 As the charge transport material of the charge transport layer in Example 4, the exemplified compound No. 2 parts of a benzidine compound of III-27,
Exemplified compound No. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 6 parts of IV-5 trialinolamine compound was used, and the same test was conducted. The results are shown in Table 7.
Shown in.

Examples 6 to 7 As the binder resin for the charge transport layer in Examples 1 and 2, the polycarbonate resin having the repeating structural unit represented by I-13 above was used instead of the polycarbonate resin represented by I-21 above. An electrophotographic photosensitive member was prepared in the same manner as in Example 1 and Example 2 except that a polycarbonate resin having a repeating structural unit (viscosity average molecular weight Mv: 20,000) was used, and the same test was conducted. It was The results are shown in Table 7. Example 8 As the binder resin for the charge transport layer in Example 1, the above I
Instead of the polycarbonate resin composed of the repeating structural unit represented by -13, 11 parts of a polycarbonate resin composed of the repeating structural unit represented by I-21 (viscosity average molecular weight Mv: 20,000) is exemplified as the charge transport material. Compound No. Instead of the benzidine compound of III-27, the exemplified compound No. An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 9 parts of the IV-7 triarylamine compound was used, and the same test was conducted. The results are shown in Table 7. Example 9 As the charge transport material in Example 8, the exemplified compound No. Instead of the triarylamine compound of IV-7, Exemplified Compound No. An electrophotographic photosensitive member was prepared in the same manner as in the method of Example 8 except that the triarylamine compound represented by IV-64 was used, and the same test was conducted. The results are shown in Table 7. Example 10 As the charge transport material in Example 8, the exemplified compound No. Instead of the triarylamine compound of IV-7, Exemplified Compound No. 1.8 parts of the benzidine compound represented by III-27, the exemplified compound No. An electrophotographic photoreceptor was prepared in the same manner as in Example 8 except that 7.2 parts of the triarylamine compound represented by IV-28 was used, and the same test was conducted. The results are shown in Table 7.

Comparative Examples 1 to 2 Instead of the polycarbonate resin comprising the repeating structural unit represented by I-13 in Examples 1 and 2, a polycarbonate resin comprising a repeating structural unit represented by the following structural formula (V) (Viscosity average molecular weight Mv:
20,000) was used, and an electrophotographic photosensitive member was produced in the same manner as in Examples 1 and 2 except that dichloromethane was used instead of monochlorobenzene, and the same test was performed. The results are shown in Table 7.

[Chemical 15]

Comparative Example 3 Instead of the polycarbonate resin having the repeating structural unit represented by I-17 in Example 4, a polycarbonate resin having a repeating structural unit represented by the following structural formula (VI) (viscosity average molecular weight Mv: 20,000)
An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that was used, and the same test was performed. The results are shown in Table 7.

[Chemical 16]

Comparative Examples 4 to 5 As the binder resin for the charge transport layer in Examples 9 and 10, the following structural formula (VII) was used instead of the polycarbonate resin composed of the repeating structural unit represented by I-21. An electrophotographic photoreceptor was prepared in the same manner as in Example 9 and Example 10 except that a polycarbonate resin (viscosity average molecular weight Mv: 21,000) composed of the repeating structural unit shown was used, and the same test was conducted. I went. The results are shown in Table 7.

[Chemical 17]

[0039]

[Table 7]

Example 11 10 parts of a zirconium compound (Organix ZC540: manufactured by Matsumoto Pharmaceutical Co., Ltd.) and a silane compound (A1110: manufactured by Nippon Unicar Co., Ltd.) on a drum-shaped aluminum substrate.
Part, 40 parts of i-propanol, 15 parts of butanol and 5 parts of distilled water were applied by a dip coating method and dried by heating at 150 ° C. for 10 minutes to give a film thickness of 0.
An undercoat layer of 1 μm was formed. Next, as an example of the charge transport material, the exemplified compound No. III-27 benzidine compound 1
0 part and 12 parts of a polycarbonate resin (viscosity average molecular weight Mv: 18,000) consisting of the repeating structural unit represented by I-17 as a binder resin were dissolved in a mixed solvent of 20 parts of monochlorobenzene and 80 parts of tetrahydrofuran. Then, 1 part of titanyl phthalocyanine was added as a charge generating material, and the mixture was treated with a glass bead for 1 hour in a sand mill to disperse, and the obtained coating solution was applied onto the above-mentioned undercoat layer by a dip coating method. After heating and drying at 120 ° C. for 60 minutes, a single-layer type electrophotographic photoreceptor having a film thickness of about 30 μm was formed. The electrophotographic photosensitive member thus obtained was mounted on a modified laser beam printer (XP-11, manufactured by Fuji Xerox Co., Ltd.), and paper feeding was not performed, that is, transfer to paper was not performed, and 30,000 A print running test was performed up to the number of sheets, and the image quality was evaluated and the amount of wear was measured. The results are shown in Table 8. Comparative Example 6 As a binder resin in Example 11, instead of the polycarbonate resin composed of the repeating structural unit represented by I-17, a polycarbonate resin composed of the repeating structural unit represented by the structural formula (VI) (viscosity average molecular weight) was used. Mv: 20,000) was used to prepare a drum type electrophotographic photosensitive member under the same conditions as in Example 11, and Example 1 was used.
The same evaluation as in 1 was performed. The results are shown in Table 8.

[0041]

[Table 8]

[0042]

INDUSTRIAL APPLICABILITY In the electrophotographic photoreceptor of the present invention, since the polycarbonate resin comprising the repeating unit represented by the general formula (I) is used as the binder resin of the photosensitive layer, the coating film of the formed photosensitive layer. Has an extremely high strength, and therefore, the electrophotographic photoreceptor of the present invention can obtain excellent copy image quality over a long period of time even if it is repeatedly used in a copying machine or a printer for a long period of time. That is, as is clear from the above comparison, the electrophotographic photosensitive member of the present invention has the effects of maintaining excellent repeated stability and having abrasion resistance.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an example of an electrophotographic photosensitive member of the present invention.

FIG. 2 is a schematic cross-sectional view of another example of the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

1 ... Photoconductive layer, 2 ... Charge generation layer, 3 ... Charge transport layer, 4 ...
Conductive support, 5 ... Undercoat layer.

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a polycarbonate resin containing a repeating structural unit represented by the following general formula (I) as a binder resin. An electrophotographic photoconductor characterized by: [Chemical 1] (In the formula, each of X ₁ and X ₂ represents a hydrogen atom, an alkyl group, an aryl group or an aryl-substituted alkyl group, or a cyclohexyl group, or X ₁ and X ₂ together form an alicyclic carbocycle or lactone. Represents an atomic group necessary for forming a ring, X ₃ represents a butyl group, X ₄ represents a hydrogen atom or a methyl group, and h represents an integer of 1 or 2.) 2. The electrophotographic photoreceptor according to claim 1, wherein the polycarbonate resin comprises a repeating structural unit represented by the following general formula (II). [Chemical 2] (In the formula, t-Bu represents a tert-butyl group, X ₁ and X ₂ each represent a hydrogen atom, an alkyl group, an aryl group or an aryl-substituted alkyl group, or a cyclohexyl group, or X ₁ and X ₂ are Represents an atomic group necessary for forming together an alicyclic carbon ring or lactone ring,
h means an integer of 1 or 2. ) 3. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains at least one benzidine compound represented by the following general formula (III) as a charge transport material. [Chemical 3] (In the formula, R ₁ and R ₁ ′ each represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom,
R ₂ , R ₂ ′, R ₃ and R ₃ ′ each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a substituted amino group, and m, m ′, n and n ′ are 1 or 2 respectively. Means an integer. ) 4. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains at least one triarylamine compound represented by the following general formula (IV) as a charge transport material. [Chemical 4] (In the formula, R ₄ represents a hydrogen atom or a methyl group, and Ar 4
₁ and Ar ₂ each represent a halogen atom, an alkyl group, an aryl group which may have an alkoxy group or a substituted amino group, or a thienyl group, and k is 1 or 2
Means an integer of. )