JP3250368B2 - 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 an electrophotographic photoreceptor having excellent mechanical strength and electrical characteristics over a long period of time.

[0002]

2. Description of the Related Art In recent years, electrophotographic technology has been applied to remarkably many applications in the fields of copiers, laser beam printers, and the like because of the advantages of obtaining high speed and high printing quality. Electrophotographic photoreceptors used in these electrophotographic technologies include selenium,
Those using inorganic photoconductive materials such as selenium-tellurium alloy, 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. I have. 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. Because of its superiority, various proposals have been made and put to practical use. On the other hand, at present, a single-layer type organic photoreceptor has systematic advantages such as manufacturability, manufacturing cost, and positive charging (reduction of ozone generation and uniform charging), but on the other hand, electrical performance is poor. There is a problem that it is inferior to a stacked type photoreceptor, and there is still enough room for research and development.

As described above, organic laminated photoconductors have been developed which have sufficient electrophotographic characteristics. However, since the photosensitive layer is made of an organic material, the photoconductor is resistant to external mechanical forces. Properties, i.e., toner, developer,
There are problems such as abrasion and scratches on the surface of the photoreceptor due to a direct load from a sheet, a cleaning member, etc., and a problem of image quality defects due to adhesion of foreign matter such as toner filming, or a problem due to corona discharge. There are problems such as image deletion in a high humidity environment caused by low resistance materials such as ozone and nitrogen oxides, and paper dust and the like generated from copy paper adhering and accumulating on the photoreceptor surface. Regulates photoreceptor life.

In addition, with the digitalization, colorization, speeding up, and miniaturization of copiers or printers, charging-exposure-
One cycle from copying to cleaning to neutralization tends to be performed in a shorter time. Therefore, the photosensitive wavelength range of the photoreceptor is changed to the wavelength of a near-infrared semiconductor laser (780 to 830).
nm), the sensitivity and long-term electrical stability of the formed photoreceptor, as well as faster photoresponsiveness, have been required. As described above, further higher durability is required in view of the complexity of these processes and higher stress. Various materials have been conventionally studied for the binder resin of the photosensitive layer in these electrophotographic photosensitive members, and for example, those using various modified polycarbonate resins as the binder resin of the photosensitive member surface layer have been proposed ( JP-A-60-1
No. 72044, JP-A-62-247374, JP-A-6-247374
JP-A-3-148263, JP-A-1-177551, JP-A-2-254458, JP-A-2-254449, JP-A-3-63651, JP-A-3-150571, JP-A-4-179951, JP-A-5 -80548, JP-A-5-142800. ) In addition, with the colorization and speeding up of copiers and printers,
The process is becoming more complicated and the stress is increasing, and from these points, further higher durability is required.

[0005]

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 it is still not sufficiently satisfactory. . That is, 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 time,
Abrasion of the surface of the photosensitive layer changes the thickness of the photoreceptor, thereby lowering the charging potential and changing the sensitivity, resulting in fogging of the copy or reduction in the copy density. . In addition, there is a problem that image quality defects occur due to surface abrasions of the photoreceptor. On the other hand, when a resin with little wear is used, there is a problem that the electrical characteristics are not sufficient, and image quality defects occur due to adhesion of foreign substances such as toner filming. Further, when forming the photosensitive layer, the compatibility of the charge transport material with the binder resin is important, and if the compatibility is low, crystallization of some charge transport materials,
It has been found that precipitation and the like occur, which significantly affects the electric characteristics and the image quality characteristics. Even if compatibility is good,
In the combination of the copolymerized polycarbonate and the benzidine-based charge transporting material described in JP-A-5-142800, there is a problem that when dissolved in a high boiling point solvent, gelation occurs in several days. Furthermore, in the case of a coating liquid using a low-boiling solvent , control of the liquid viscosity, the surface of the coating film becomes a citrus skin, or whitening by absorbing moisture in the air (brushing)
And the like, and the productivity and yield of the photoconductor are deteriorated. The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a stable and excellent manufacturability without gelling in a solvent having a high boiling point, and furthermore, a specific charge transport material and / or An object of the present invention is to provide an electrophotographic photoreceptor in which the use of a specific charge generating material further improves abrasion resistance and can maintain excellent intrinsic electric 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 by containing a special polycarbonate resin as a binder resin, both electrical characteristics and image quality can be achieved. Further, they have found that the belt-shaped photoreceptor does not cause any crack defect and that the abrasion resistance can be further improved, thereby completing the present invention. That is, the present invention provides a method for forming a charge transport layer and a charge transport layer on a conductive support.
An electrophotographic photoreceptor provided with a photosensitive layer formed by sequentially laminating layers, wherein the charge generation layer is formed of gallium phthalocyanine.
A charge generation layer comprising a charge generation material comprising
But as the binder resin, the following formula (I), the general formula (II)
And a copolymerized polycarbonate resin comprising a repeating structural unit represented by the general formula (III).

Embedded image (Wherein, R represents a hydrogen atom, a methyl group or an aryl group, and X ₁ , X ₂ and X ₃ each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aryl-substituted alkyl group, or a cyclohexyl group. , X ₄ and X
₅ represents a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, an aryl group or an aryl-substituted alkyl group, respectively, or X ₄ and X ₅ are taken together to form a carbocyclic or lactone ring. It represents a necessary atomic group, provided that X ₄ and X ₅ are not the same as the group R and the phenyl group in the formula (I) , and X ₆ represents a hydrogen atom or a methyl group. )

Hereinafter, the electrophotographic photosensitive member of the present invention will be described in more detail. FIG . 1 is a schematic sectional view of an embodiment of the electrophotographic photoreceptor of the present invention . In FIG. 1, a charge generation layer 1 and a charge transport layer 2 are formed on a conductive support 3. In FIG. 2, the undercoat layer 4 is provided on the conductive support 3, and in FIG. 3, the protective layer 5 is provided on the surface. Also in FIG. 4, that are provided with both of the protective layer 5 and the undercoat layer 4.

Examples of the conductive support include metals such as aluminum, nickel, chromium, and stainless steel; and aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, and ITO.
And a plastic film provided with a thin film such as the above, or a paper or plastic film 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, oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed on the surface.

In the present invention, it is preferable to provide an undercoat layer between the conductive support and the photosensitive layer. This undercoat layer prevents the injection of electric charge from the conductive support to the photosensitive layer when the photosensitive layer is charged, and acts as an adhesive layer for integrally bonding and holding the photosensitive layer to the conductive support. Alternatively, in some cases, the conductive support has an effect of preventing light from being reflected. The following materials can be used as a material for the undercoat layer. 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, chloride Vinyl-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, zirconium chelate compound, titanyl chelate compound, Known materials such as a titanyl alkoxide compound, an organic titanyl compound, and a silane coupling agent can be used. These materials can be used alone or in combination of two or more. Further, fine particles such as titanium oxide, aluminum oxide, silica, zirconium oxide, barium titanate, and silicone resin can be mixed. The method as the coating method for forming the undercoat layer, a blade coating method, Meyer barcodes plating method, spray coating, dip coating, bead coating, air knife coating, is typically used in curtain coating Is adopted.
The thickness of the undercoat layer is 0.01 to 10 μm, preferably 0.0
It is set to 5-2 μm.

[0010] In the electrophotographic photoreceptor of the present invention, a photosensitive layer coated on a conductive support, der ones of the stacked structure in which a conductive load generating layer and a charge transport layer are functionally separated by sequentially stacking
You . These photosensitive layer, a charge generating material, the charge transport materials is Ru is composed of coating film contained in <br/> binder resin.

[0011] The charge generation layer or the charge generating material is formed by vacuum deposition, or the binder resin in an organic solvent and dispersing the charge-generating material, Ru can be formed by coating.

In the present invention, the charge generation material
Is a gallium phthalocyanine compound . Photoreceptors using these gallium phthalocyanine compounds are:
Near-infrared semiconductor laser wavelength (780-830 nm)
High sensitivity and stable electrical properties over a long period of time.
Specifically, at least the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum by CuKα is at least 6.
Gallium phthalocyanine having strong diffraction peaks at 8 °, 12.8 °, 15.8 ° and 26.0 ° (see FIG. 5 ), at the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum by CuKα, At least 7.5 °,
9.9 °, 12.5 °, 16.3 °, 18.6 °, 2
Hydroxygallium phthalocyanine with strong diffraction peaks at 5.1 ° and 28.3 ° (see FIG. 7 ), CuK
Bragg angle of X-ray diffraction spectrum by α (2θ ±
0.2 °), at least 7.4 °, 16.6
Chlorogallium phthalocyanine having a strong diffraction peak at chlorogallium phthalocyanine (see FIG. 6 ) having strong diffraction peaks at °, 25.5 ° and 28.3 ° can be mentioned as a preferable example.

Examples of the binder resin in the charge generation layer include polyvinyl butyral resins, polyvinyl formal resins, polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins in which a part of butyral is modified with formal or acetoacetal, and polyamides. Resin, polyester resin, modified ether type polyester resin, polycarbonate resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, silicone resin, phenol resin, phenoxy Resin, melamine resin, benzoguanamine resin, urea resin, polyurethane resin, poly-N-vinylcarbazole resin, polyvinylanthracene resin, polyvinylpyrene resin, etc. Among these, polyvinyl acetal resins, vinyl chloride-vinyl acetate copolymers,
Phenoxy resins and modified ether type polyester resins are preferred. Because these resins disperse the phthalocyanine pigment well, the pigment is not aggregated, the dispersion coating solution is stable for a long time, and a uniform film is formed by using the coating solution. This is because electrical characteristics can be improved and image quality defects can be reduced. However, the resin is not limited to these as long as it can form a film in a normal state. These binder resins can be used alone or in combination of two or more. The mixing ratio of the charge generation material and the binder resin is 5: 1 to 1 by volume.
A range of 1: 2 is preferred.

Solvents used for preparing the coating solution include methanol, ethanol, n-propanol and n-propanol.
-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 can be used alone or in combination of two or more. As a method of applying the coating solution, 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 and a curtain coating method can be used. The thickness of the charge generation layer is generally from 0.01 to 5 μm, preferably from 0.1 to 2.0 μm. If the thickness of the charge generation layer is less than 0.01 μm, it is difficult to form the charge generation layer uniformly, and if it exceeds 5 μm, the electrophotographic properties tend to be significantly reduced.

Examples of the charge transporting material contained in the charge transporting layer include p-benzoquinone, chloranil, bromoanil,
Electron-withdrawing substances such as quinone compounds such as anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds, cyanovinyl compounds and ethylene compounds Having a residue consisting of a triarylamine-based compound, a benzidine-based compound, an arylalkane-based compound, an aryl-substituted ethylene-based compound, a stilbene-based compound, an anthracene-based compound, a hydrazone-based compound, or a compound thereof in a main chain or a side chain. An electron donating substance such as a polymer may be used. 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.

As the benzidine compound, a compound represented by the following general formula (IV) is preferable.

Embedded image (Wherein, 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' are each a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a substituted amino group. Further, m, m ', n and n' each represent an integer of 1 or 2. )

Among the benzidine compounds represented by the above general formula (IV), the following general formula (IV-i) or general formula (IV-ii) described in JP-A-62-247374.
It is preferable to use the compound represented by

Embedded image (In the formula, R ₅ , R ₅ ′, R ₆ , and R ₆ ′ each represent a hydrogen atom or a methyl group.)

Embedded image (Wherein, 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.) When a compound is used, the solubility in a solvent and the 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 produce an electrophotographic photoreceptor having particularly high sensitivity and excellent repetition stability.

Further, as the triarylamine-based compound, a compound represented by the following general formula (V) is preferable.

Embedded image (Wherein, R ₄ represents a hydrogen atom or a methyl group;
₁ and Ar ₂ each represent a halogen atom, an alkyl group, an alkoxy group or an aryl group or a thienyl group which may have a substituted amino group, and k represents an integer of 1 or 2. )

Here, specific examples of benzidine compounds are listed in Tables 1 and 2, and specific examples of triarylamine compounds are listed in Tables 3 to 6, respectively.

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4]

[0023]

[Table 5]

[0024]

[Table 6]

The benzidine compound and the triarylamine compound are not limited to the compounds shown in Tables 1 to 6. For example, in Tables 1 and 2, for convenience, R
₁ and R ₁ ′, R ₂ and R ₂ ′, and R ₃ and R ₃ ′ are the same benzidine-based compounds. However, these are not necessarily the same as each other, and further, R ₁ ′, R ₂ ′, And the substitution position of R ₃ 'may not be the same as R ₁ , R ₂ and R ₃ . The benzidine compound and the triarylamine compound may be used alone or in combination of two or more.

As the binder resin in the charge transport layer, use is made of a copolymerized polycarbonate resin comprising repeating structural units represented by the following general formulas (I), (II) and (III).

Embedded image (In the formula, X _{1 to} X ₆ and R are the same as described above.)

As X _{2 to} X ₅ in the general formula (II), the following substituents can be exemplified. For example, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group may be linear or branched, a methyl group,
Ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, octadecyl and the like. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. Examples of the alicyclic hydrocarbon group include bicyclo [2.2.
1] A heptyl group. Examples of the aryl group include a phenyl group, a naphthyl group and a biphenyl 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.
The alkyl group may be branched, and in the aryl-substituted alkyl group having an alkyl moiety having 2 or more carbon atoms, the aryl group may be substituted not only at the terminal carbon but also at another carbon. Further, the aryl portion of the aryl group and the aryl-substituted alkyl group may be substituted with one or more substituents such as the above-described halogen atoms and alkyl groups. The alicyclic carbocycle formed together with the carbon atom to which X ₄ and X ₅ are bonded includes a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclooctylidene group and the like. Examples include divalent alicyclic compound residues. Similarly, examples of the lactone ring formed together with carbon atoms include divalent residues such as butyrolactone, valerolactone, caprolactone, and caprinolactone.

In the present invention, the copolymerized polycarbonate resin comprising the repeating structural units represented by the above general formulas (I), (II) and (III) has a viscosity average molecular weight of 10,000 to 200,000. In the case of a copolymerized polycarbonate resin having a relatively uniform molecular weight distribution, those having a molecular weight distribution in the range of 20,000 to 100,000 are preferable. 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 unevenness when immersion coating occurs. Also, in the case of 10,000 to 20,000, the formed coating film has low mechanical strength and poor abrasion resistance. If it is larger than 200,000, on the contrary, there is a problem that the viscosity of the coating solution is too high and it is difficult to control a required film thickness. However, these problems can be improved by appropriately mixing and using a copolymerized polycarbonate resin having a viscosity-average molecular weight of 10,000 to 200,000, so that the above-mentioned copolymerized polycarbonate resin having a different viscosity-average molecular weight is mixed. You may use it. In addition, as long as the function and effect of the copolymerized polycarbonate resin are not impaired, a mixture of different types of polycarbonate resins or a copolymerized resin may be used.

Examples of the repeating structural unit represented by the general formula (I) include the following structural formulas.

Embedded image

Examples of the repeating structural unit represented by the general formula (II) include those shown in Tables 7 to 10 below.

[Table 7]

[0031]

[Table 8]

[0032]

[Table 9]

[0033]

[Table 10]

[0034]

[Table 11]

Further, examples of the repeating structural unit represented by the general formula (III) include those having the following structural formulas.

Embedded image

Preferred examples of the copolymerized polycarbonate resin comprising the repeating structural units represented by the above general formulas (I), (II) and (III) are those having a repeating structure shown in Table 12 below. A combination of units can be given.

[Table 12]

Among these, those represented by the following structural formula are particularly preferred.

Embedded image (Where k, m and n are molar ratios and k: m: n
= 5 to 50:20 to 70:10 to 40. )

These copolycarbonate resins are:
It can be produced by a usual synthesis method in which phenolic compounds represented by the following general formulas (I '), (II') and (III ') are reacted with phosgene.

Embedded image (In the formula, X _{1 to} X ₆ and R have the same meanings as described above.)

In the method of copolymerizing using these three or more phenolic compounds, three or more phenolic compounds are first reacted simultaneously with phosgene.
There is a method of reacting a kind of phenolic compound, adding another phenolic compound at a later time to react, and a method of further mixing and reacting the oligomers each reacted with phosgene, and can be arbitrarily selected from these. .
In the copolymerized polycarbonate resin used in the present invention,
A repeating unit represented by the general formula (I); a repeating unit represented by the general formula (II);
The content ratio with the repeating structural unit represented by ()) is (I) :( II) :( III) = 5 to 50:20 to 70:10 to 4 in a molar ratio.
It is preferably 0, particularly preferably (I): (II): (III)
= 25-40: 30-55: 20-35.

In the charge transport layer of the electrophotographic photoreceptor of the present invention, the weight ratio of the charge transport material to the binder resin is suitably in the range of 10:90 to 70:30.
The range of 0:70 to 60:40 is particularly preferred. Further, as the solvent used when providing the charge transport layer, benzene, toluene, aromatic hydrocarbons such as xylene, halogenated aromatic hydrocarbons such as chlorobenzene, acetone,
Commonly used organic solvents such as ketones such as methyl ethyl ketone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform and ethylene chloride, and cyclic or linear ethers such as tetrahydrofuran and ethyl ether are exemplified. These solvents can be used alone or in combination of two or more. As the application method, a commonly used method 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 can be used. The thickness of the charge transport layer in the invention is generally set at 5 to 70 μm, preferably 10 to 50 μm. When the thickness of the charge transporting layer is less than 5 μm, the initial charging potential tends to be low, and when it exceeds 70 μm, the electrophotographic properties and image quality tend to deteriorate.

Further, in order to prevent the deterioration of the photoreceptor due to ozone or oxidizing gas generated in the copying machine, light or heat, an antioxidant, a light stabilizer, a heat stabilizer and the like are added to the photosensitive layer. Agents can be added. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

[0042] In the electrophotographic photoreceptor of the present invention, a protective layer may be formed on the conductive charge transport layer.

[0043]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto. In the examples and comparative examples, “parts” means parts by weight. Example 1 10 parts of a zirconium compound (Orgatic ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 1 part of a silane compound (A1110, manufactured by Nippon Unicar) and i-
A solution consisting of 40 parts of propanol and 20 parts of butanol was applied by a dip coating method.
By heating and drying for 0 minutes, an undercoat layer having a thickness of 0.1 μm was formed. Next, the X-ray diffraction spectrum shown in FIG.
A mixture of 1 part of gallium phthalocyanine having octol, 1 part of polyvinyl butyral resin (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone was subjected to dispersion treatment for 1 hour together with glass beads by a sand mill, and the resulting coating solution was obtained. Is applied on the undercoat layer by a dip coating method, and dried by heating at 100 ° C. for 10 minutes.
A charge generation layer having a thickness of 0.2 μm was formed. Next, a copolymerized polycarbonate (viscosity average molecular weight 40,000) represented by the following structural formula (VI) (PC2170, manufactured by Idemitsu Kosan Co., Ltd.)
And 12 parts of Exemplified Compound No. 8 parts of the benzidine compound of IV-27 was dissolved in 100 parts of monochlorobenzene, and the obtained coating solution was applied on the charge generation layer.
Heat and dry at 35 ° C. for 60 minutes to obtain a film thickness of about 20 μm.
Was formed. In this case, the state of the coating solution and the coating film was visually observed.

The electrophotographic characteristics of the electrophotographic photosensitive member produced as described above were measured as follows. Electrostatic paper tester (electrostatic analyzer:
Using EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.), a corona discharge of -6 KV was performed in an environment of normal temperature and normal humidity (20 ° C., 40% RH) to charge the electrophotographic photosensitive member, and then the light of a tungsten lamp was used. Was dispersed into monochromatic light of 800 nm using a monochromator, adjusted to 1 μW / cm ² on the surface of the photoreceptor, and irradiated. And the initial surface potential V
0 (volts), half-exposure exposure E1 / 2 (erg / cm ² ), and then irradiate 10 lux of white light for 1 second,
The residual potential VRP (volt) was measured. Further, V0, E1 / 2, V after repeating the above charging and exposure 1000 times.
RP was measured. Table 13 shows the results.

Embedded image (Where k: m: n = 10: 12: 9)

Comparative Example 1 The gallium phthalocyanine used as the charge generating material in Example 1
Using titanyl phthalocyanine in place of the copolymer, and replacing the copolymerized polycarbonate resin represented by the structural formula (VI) of the charge transport layer with a copolymerized polycarbonate resin represented by the following structural formula (VII) (average viscosity molecular weight: 39,000)
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that (PC3504, manufactured by Idemitsu Kosan Co., Ltd.) was used, and a similar test was performed. Table 13 shows the results.

Embedded image (Where m: n = 4: 1)

Comparative Example 2 Gallium phthalocyanine as the charge generating material in Example 1
And titanyl phthalocyanine in place of the copolymer, and a copolymerized polycarbonate resin represented by the following structural formula (VIII) (average viscosity molecular weight: 45,000) instead of the copolymerized polycarbonate resin represented by the structural formula (VI) of the charge transport layer.
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that (PC3358, manufactured by Idemitsu Kosan Co., Ltd.) was used, and a similar test was performed. Table 13 shows the results.

Embedded image (Where k: m = 1: 1).

Comparative Example 3 Gallium phthalocyanine as the charge generating material in Example 1
Instead of using a titanyl phthalocyanine in place of the compound, a unit polycarbonate resin having a repeating structure represented by the following structural formula (IX) (PC3359,
(Idemitsu Kosan Co., Ltd.) and a polycarbonate resin (Panlite K) comprising a repeating structural unit represented by the following structural formula (X)
1300, manufactured by Teijin Chemicals Co., Ltd.) and using an electrophotographic photoreceptor in the same manner as in Example 1 except that a mixed solvent of methylene chloride and 1,1,2-trichloroethane in a ratio of 1: 1 was used instead of monochlorobenzene. Was produced, but the coating film became white and opaque. It was found that not only the coating surface caused brushing but also that these polycarbonate resins were not compatible.

Embedded image

[0048]

[0049]

[0050]

[0051]

[Table 13]

[0052]

[0053]

[0054]

[0055] as a charge generating material of Example 2 conductive load generating layer, using a phthalocyanine having an X-ray diffraction spectrum shown in FIG. 5, as the charge transport material in the charge transport layer, the exemplified compound No.
In place of the benzidine compound of IV-27, Exemplified Compound No. An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the triarylamine-based compound of V-64 was used, and the same test was performed. Table 14 shows the results. As a charge generating material of Example 3 conductive load generating layer, using the chlorogallium phthalocyanine having an X-ray diffraction spectrum shown in FIG. 6, a carboxyl-modified vinyl chloride in place of polyvinyl butyral resin as a binder resin - vinyl acetate copolymer (VMCH, manufactured by Union Carbide Co.) except that n-butyl acetate was used instead of cyclohexanone.
An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the same test was performed. Table 14 shows the results. Example 4 The charge-transporting material of the charge-transporting layer in Example 3 was replaced with the above-mentioned Compound No. An electrophotographic photosensitive member was prepared in the same manner as in Example 3 except that the triarylamine compound of V-7 was changed to 9 parts, and a similar test was performed. Table 14 shows the results.
Shown in Example 5 The charge-transporting material of the charge-transporting layer in Example 3 was replaced with the above-mentioned Compound No. IV-27, 2 parts of the benzidine compound and Exemplified Compound No. An electrophotographic photosensitive member was prepared in the same manner as in Example 3 , except that the mixture of 6 parts of the triarylamine compound of V-28 was used, and the same test was performed. Table 14 shows the results.

[0056] As a charge generating material of Example 6 conductive load generating layer, hydroxygallium phthalocyanine using a partial acetal instead of the polyvinyl butyral resin as a binder resin polyvinyl butyral resin having an X-ray diffraction spectrum shown in FIG. 7 ( BX-L, manufactured by Sekisui Chemical Co., Ltd.) except that n-butyl acetate was used instead of cyclohexanone.
An electrophotographic photoreceptor was prepared in the same manner as described above, and the same test was performed. Table 14 shows the results. Example 7 The modified vinyl chloride-vinyl acetate copolymer (VMCH, manufactured by Union Carbide) was used in place of the polyvinyl butyral resin as the binder resin of the charge generation layer in Example 6 , and the charge transport material of the charge transport layer was used. As the above exemplified compound No. IV-27, 2 parts of the benzidine compound, Exemplified Compound No. An electrophotographic photoreceptor was prepared in the same manner as in Example 6 , except that 6 parts of the triarylamine-based compound V-7 was mixed and used, and a similar test was performed. Table 14 shows the results. Example 8 As the charge transporting material for the charge transporting layer in Example 6 , the above-mentioned Compound No. 1 was used. In place of the mixture of IV-27, Exemplified Compound No. An electrophotographic photosensitive member was prepared in the same manner as in Example 6 , except that 9 parts of the triarylamine of V-28 was used, and a similar test was performed. Table 14 shows the results.

[0057]

[Table 14]

[0058]

[0059]

[0060]

[0061]

According to the electrophotographic photosensitive member of the present invention, the product
As a binder resin of the charge transport layer in the photosensitive layer having a layer structure ,
Using a copolymerized polycarbonate resin comprising repeating units represented by the above general formulas (I), (II) and (III),
In addition, gallium phthalocyanine compound is used as a charge generation material.
The Rukoto with things, high-boiling dissolved in a solvent coating solution excellent in stability and manufacturability without gelation, the coating liquid photosensitive layer coating film formed by the wear resistance not higher. Also, the electrophotographic photoreceptor of the present invention without causing problems even after repeated use and long-term in copiers and printers in the photosensitive layer, the electrophotographic characteristics without reducing the length of the copy quality of excellent image quality It has high durability that can be obtained over a period. The electrophotographic photosensitive member of the present invention maintains a superior repetition stability, and those having a high printing durability.

[Brief description of the drawings]

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

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

FIG. 3 is a schematic sectional view of another example of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a schematic sectional view of another example of the electrophotographic photosensitive member of the present invention.

FIG. 5 shows gallium phthalo used in Examples 1 and 2.
X-ray powder diffraction spectrum of cyanine by CuKα
is there.

FIG. 6 shows a chlorogallium lid used in Examples 3 to 5 .
X-ray powder diffraction spectrum of Russiannin by CuKα
It is.

FIG. 7: Hydroxygallium used in Examples 6-8
X-ray powder diffraction spectrum of phthalocyanine by CuKα
FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Charge generation layer, 2 ... Charge transport layer, 3 ... Conductive support,
4 ... Undercoat layer, 5 ... Protective layer.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Ryosaku Igarashi 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (56) References JP-A-6-248066 (JP, A) JP-A-6-27692 ( JP, A) JP-A-5-289372 (JP, A) JP-A-5-289371 (JP, A) JP-A-5-257300 (JP, A) JP-A-2-25464 (JP, A) JP JP-A-6-75408 (JP, A) JP-A-6-67444 (JP, A) JP-A-5-188615 (JP, A) JP-A-5-98181 (JP, A) JP-A-5-263007 (JP) JP-A-5-247361 (JP, A) JP-A-5-194523 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/00

Claims (12)

(57) [Claims] 1. A charge generating layer and a charge transport layer on a conductive support.
An electrophotographic photoreceptor provided with a photosensitive layer formed by sequentially laminating layers, wherein the charge generation layer is formed of gallium phthalocyanine.
A charge generation layer comprising a charge generation material comprising
But as the binder resin, the following formula (I), the general formula (II)
And an electrophotographic photosensitive member comprising a copolymerized polycarbonate resin comprising a repeating structural unit represented by the general formula (III). Embedded image (Wherein, R represents a hydrogen atom, a methyl group or an aryl group, and X ₁ , X ₂ and X ₃ each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aryl-substituted alkyl group, or a cyclohexyl group. , X ₄ and X
₅ represents a hydrogen atom, an alkyl group, an alicyclic hydrocarbon group, an aryl group or an aryl-substituted alkyl group, respectively, or X ₄ and X ₅ are taken together to form a carbocyclic or lactone ring. It represents a necessary atomic group, provided that X ₄ and X ₅ are not the same as the group R and the phenyl group in the formula (I) , and X ₆ represents a hydrogen atom or a methyl group. ) 2. The electrophotographic photosensitive member according to claim 1, wherein the repeating structural unit represented by the general formula (I) is represented by the following structural formula (I ′). Embedded image 3. The electrophotographic photoreceptor according to claim 1, wherein the copolymerized polycarbonate resin has a viscosity average molecular weight of 20,000 or more. 4. The electrophotographic photoconductor according to claim 1, wherein the charge transport layer contains at least one benzidine compound represented by the following general formula (IV) as a charge transport material. Embedded image (Wherein, 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' are each a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a substituted amino group, m, m ', n and n', respectively 1 or 2 Means an integer. ) 5. The electrophotographic photoreceptor according to claim 1, wherein the charge transport layer contains at least one triarylamine compound represented by the following general formula (V) as a charge transport material. Embedded image (Wherein, R ₄ represents a hydrogen atom or a methyl group;
₁ and Ar ₂ represent a halogen atom, an alkyl group, an alkoxy group, or an aryl group or a thienyl group which may have a substituted amino group, and k is 1 or 2
Means an integer. ) 6. The electrophotographic photoreceptor according to claim 1, wherein a mixture of the benzidine compound and the triarylamine compound is used as a charge transport material in the charge transport layer. 7. An outermost surface of the photosensitive layer contains a copolymerized polycarbonate resin comprising a repeating structural unit represented by the general formula (I), the general formula (II) and the general formula (III). The electrophotographic photoreceptor according to claim 1. 8. The method according to claim 1, wherein the gallium phthalocyanine compound is
Bragg angle of X-ray diffraction spectrum by CuKα (2
θ ± 0.2 °), at least 6.8 °, 12.
Strong diffraction peaks at 8 °, 15.8 ° and 26.0 °
Gallium phthalocyanine having
The electrophotographic photosensitive member according to claim 1. 9. The gallium phthalocyanine is CuK
Bragg angle of X-ray diffraction spectrum by α (2θ ±
0.2 °), at least 7.5 °, 9.9 °,
12.5 °, 16.3 °, 18.6 °, 25.1 ° and
With strong diffraction peaks at 28.3 ° and 28.3 °
2. The method according to claim 1, wherein said phthalocyanine is umphthalocyanine.
The electrophotographic photosensitive member according to the above. 10. The method according to claim 1, wherein the gallium phthalocyanine is Cu
Bragg angle of X-ray diffraction spectrum by Kα (2θ ±
0.2 °), at least 7.4 °, 16.6
Strong diffraction peaks at °, 25.5 ° and 28.3 °
Chlorogallium phthalocyanine
The electrophotographic photoreceptor according to claim 1. 11. The charge generation layer as a binder resin,
Polyvinyl acetal Le resin, vinyl chloride - vinyl acetate
Selected from copolymers and polyester resins
2. The composition according to claim 1, wherein the composition contains at least one of them.
Electrophotographic photoreceptor. 12. Between a conductive support and the charge generation layer
2. An electrode according to claim 1, further comprising an undercoat layer.
Child photoreceptor.