JPH07191480A - Electrophotographic photoreceptor and process cartridge and electrophotographic device having the same - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic photoreceptor having high sensitivity and stably having superior potential characteristics even when it is repeatedly used by incorporating a specified disazo pigment into the photosensitive layer of an electrophotographic photoreceptor with the photosensitive layer on the electric conductive substrate. CONSTITUTION:The photosensitive layer of this electrophotographic photoreceptor contains a disazo pigment represented by formula I, wherein each of R1 and R2 is H, halogen, alkyl, alkoxy or cyano, each of A1 and A2 is a residue of a coupler having a phenolic hydroxyl group, A1 and A2 may be different from each other and at least one of them is a residue of a coupler represented by formula II where X1 is a residue required to form a polycyclic arom. ring or hetero ring by condensation with the benzene ring, each of R3 and R4 is H, alkyl, aryl, aralkyl or a heterocyclic group, R3 and R4 may be residues forming a cyclic amino group by bonding to each other and Z1 is O or S.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
Specifically, it relates to an electrophotographic photoreceptor having a photosensitive layer containing a disazo pigment having a specific structure. The present invention also relates to a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member using an organic photoconductive material has advantages such as extremely high productivity and relatively low cost, and in addition, a dye or pigment to be used is selected. This has the advantage that the wavelength range having sensitivity can be freely controlled, and has been extensively studied so far. In particular, a function in which a charge generating layer containing a charge generating substance such as an organic photoconductive dye or pigment and a charge transporting layer containing a charge transporting substance such as a photoconductive polymer or a low molecular weight organic photoconductive substance are laminated. With the development of the electrophotographic photoreceptor having the separation type photosensitive layer, the sensitivity and durability, which have been the drawbacks of the conventional organic electrophotographic photoreceptor, have been remarkably improved. Among organic photoconductive substances, many azo pigments have excellent photoconductivity, and moreover, pigments having various characteristics can be obtained relatively easily by combining amine components and coupler components. Many azo pigments have been disclosed in, for example, JP-A-6
Nos. 0-57348, 61-215556, and 2-84659 have been proposed.

[0003]

However, with the recent demand for higher image quality and higher durability, an electrophotographic photosensitive member having higher sensitivity and more excellent electrophotographic characteristics during repeated use. Is being considered.

An object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity.

Another object of the present invention is to provide an electrophotographic photosensitive member having stable and excellent potential holding property even after repeated use.

A further object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member as described above.

[0007]

That is, the present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following formula (1).

[0008]

[Outside 4] (In the formula, R ₁ and R ₂ are the same or different and each is a hydrogen atom,
A halogen atom, an alkyl group, an alkoxy group and a cyano group are shown, A ₁ and A ₂ are the same or different and each represents a coupler residue having a phenolic hydroxyl group, and at least one of A ₁ and A ₂ is represented by the following formula (2):

[0009]

[Outside 5] (In the formula, X ₁ represents a residue necessary for forming a polycyclic aromatic ring or a heterocyclic ring by being condensed with a benzene ring, and R ₃ and R ₄
Are the same or different and represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a heterocyclic group and a residue forming a cyclic amino group by bonding with each other, and Z ₁ represents an oxygen atom or a sulfur atom. ) Is a coupler residue. ] It is an electrophotographic photosensitive member characterized by containing the disazo pigment shown by these.

The present invention also provides a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

In the above formula (1), the halogen atom of R ₁ and R ₂ includes a fluorine atom, a chlorine atom and an iodine atom, the alkyl group includes a group such as methyl, ethyl and propyl, and alkoxy. Examples of the group include groups such as methoxy, ethoxy and propoxy. In the present invention, R ₁ and R ₂ may be the same or different, and the four R ₁ need not be the same, and the four R ₂
Are not necessarily the same, but it is preferred that all R ₁ and R ₂ are hydrogen atoms. Further, the formula (1) is preferably represented by the following formula from the viewpoint of easiness of synthesis and the like.

[0012]

[Outside 6] (In the formula, A ₁ and A ₂ have the same meanings as in formula (1).) Further, A ₁ and A ₂ represent a coupler residue having a phenolic hydroxyl group, and the coupler residue means a disazo pigment. Is a group corresponding to a part of the coupler bonded to the azo group by the coupling reaction of the diazo component and the coupler when obtaining the compound, and is preferably bonded to the azo group at the position ortho to the phenolic hydroxyl group. . In the present invention, at least one of A ₁ and A ₂ is a coupler residue represented by the formula (2). In formula (2), examples of the polycyclic aromatic ring and heterocyclic ring formed by condensing with the benzene ring of X ₁ include a naphthalene ring, anthracene ring, carbazole ring, benzocarbazole ring and dibenzocarbazole ring. Further, examples of the alkyl group of R ₃ and R ₄ include groups such as methyl, ethyl and propyl, examples of the aryl group include groups such as phenyl, naphthyl and anthryl, and examples of the aralkyl group include groups such as benzyl and phenethyl. Examples of the heterocyclic group include pyridyl, thienyl, thiazole, carbazolyl, benzimidazolyl and benzothiazolyl groups, and the cyclic amino group includes pyrrolyl, indolyl, indolinyl,
Examples include groups such as carbazolyl, imidazolyl, benzimidazolyl, pyrazolyl, phenothiazinyl and phenoxazinyl.

R ₃ , R ₄ and X ₁ may have a substituent, and as the substituent which may be substituted, an alkyl group such as methyl, ethyl and propyl; alkoxy such as methoxy, ethoxy and propoxy. Group; halogen atom such as fluorine, chlorine, bromine and iodine; acyl group such as acetyl and benzoyl; alkylamino group such as dimethylamino and diethylamino; phenylcarbamoyl group; nitro group; cyano group; and halomethyl group such as trifluoromethyl Etc.

In the present invention, it is preferable that both A ₁ and A ₂ are coupler residues represented by the formula (2).
When only one is the coupler residue represented by the formula (2), the other may be any coupler residue having a phenolic hydroxyl group, but the following formula (3)
It is preferably a coupler residue represented by any one of (8) to (8).

[0015]

[Outside 7]

[0016]

[Outside 8] X _{2 to} X _{5 in} formulas (3), (6), (7) and (8)
Represents a residue necessary for condensation with a benzene ring to form a polycyclic aromatic ring such as naphthalene ring and anthracene ring or a heterocycle such as carbazole ring, benzocarbazole ring and dibenzocarbazole ring.

Y ₁ in the formula (5) represents an arylene group or a divalent heterocyclic group containing a nitrogen atom in the ring. Specifically, 0-phenylene, 0-naphthylene, perinaphthylene,
1,2-anthrylene, 3,4-pyrazolediyl,
2,3-pyridinediyl, 4,5-pyridinediyl,
Groups such as 6,7-indazoldiyl and 6,7-quinolinediyl are mentioned.

R ₅ , R ₆ and R _{9 in the} formulas (3) and (7)
And R ₁₀ represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group and a heterocyclic group, and R ₅ and R ₆ and R ₉
And R ₁₀ represent a residue which is bonded to each other to form a cyclic amino group.

R ₇ in the formula (4) represents an alkyl group, an aryl group, an aralkyl group or a heterocyclic group.

R ₈ in the formula (6) represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group or a heterocyclic group.

R ₁₁ and R ₁₂ in the formula (8) represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a heterocyclic group, and a residue forming a ring group by being bonded to each other.

The above-mentioned alkyl group is a group such as methyl, ethyl and propyl, the aryl group is a group such as phenyl, naphthyl and anthryl, the aralkyl group is a group such as benzyl and phenethyl, and the heterocyclic group is pyridyl and thienyl. And groups such as thiazolyl, carbazolyl, benzimidazolyl and benzothiazolyl. Examples of the cyclic amino group include groups such as pyrrolyl, indolyl, indolinyl, carivazolyl, imidazolyl, benzimidazolyl, pyrazolyl, phenothiazinyl and phenoxazinyl. Further, examples of the ring group formed by combining R ₁₁ and R ₁₂ include groups such as fluorenylidene, xanthenylidene, antronylidene, and hydroindenylidene.

X _{2 to} X ₅ , Y ₁ , and R _{5 to} R ₁₂ may have a substituent, and the substituent which may be substituted is an alkyl group such as methyl, ethyl and propyl; methoxy,
Alkoxy groups such as ethoxy and propoxy; halogen atoms such as fluorine, chlorine, bromine and iodine; acyl groups such as acetyl and benzoyl; alkylamino groups such as dimethylamino and diethylamino; phenylcarbamoyl groups;
Examples thereof include a nitro group; a cyano group; and a halomethyl group such as trifluoromethyl.

Z ₂ in the formula (6) represents an oxygen atom or a sulfur atom.

In the present invention, A ₁ and A ₂ are represented by a formula selected from the group consisting of formulas (2), (3), (6), (7) and (8), and X _{1 in} the formula And X ₅ is a coupler residue which is condensed with a benzene ring to form a benzocarbazole ring, the disazo pigment has a sensitivity region extending to the near-infrared region, and therefore, as a charge generating substance for a semiconductor laser. Can also be preferably used.

Preferred examples of the disazo pigment represented by the formula (1) are listed below, but the disazo pigment used in the present invention is not limited thereto. The exemplary pigments are expressed by first showing the basic type and showing the changing parts A ₁ and A ₂ therein.

[0027]

[Outside 9]

[0028]

[Outside 10]

[0029]

[Outside 11]

[0030]

[Outside 12]

[0031]

[Outside 13]

[0032]

[Outside 14]

In the disazo pigment used in the present invention, the corresponding diamine is tetrazolated by a conventional method, and the obtained tetrazonium salt and the corresponding coupler are coupled in an aqueous system in the presence of an alkali, or the tetrazonium salt is fluorinated. Coupling with a corresponding coupler in the presence of a base such as sodium acetate, triethylamine and N-methylmorpholine in an organic solvent such as N, N-dimethylformamide or dimethylsulfoxide after conversion to a zinc chloride double salt or the like. Can be easily synthesized by. Formula (1)
In order to synthesize a disazo pigment in which A ₁ and A ₂ are different coupler residues, 1 mol of one coupler is first coupled to 1 mol of the above tetrazonium salt, and then the other coupler 1 is used. Syntheses by coupling moles, or by mixing two types of couplers, one mole each,
It can be synthesized by coupling with a tetrazonium salt.

Synthesis Example (Synthesis of Pigment Example 1) 4,10-Diaminoanthanthrone 10 g (0.03)
Mol) was dissolved in 270 g of concentrated sulfuric acid and cooled to 0 ° C. 4.3g (0.063) of sodium nitrite was added to this solution.
2 mol of nitrosyl sulfuric acid dissolved in 100 g of concentrated sulfuric acid.
It was added to the liquid over 0 minutes, stirred for 5 hours, and then filtered.
10 g (0.10) of sodium borofluoride was added to the obtained filtrate.
(Mole) dissolved in 30 ml of water was added dropwise with stirring while maintaining the liquid temperature at 10 ° C or lower, and the mixture was further stirred for 1 hour. The protruding borofluoride salt was collected by filtration, washed successively with cold water and acetonitrile, and then dried under reduced pressure at room temperature. Yield 13.9g
And the yield was 85%.

Next, 500 ml of dimethylformamide was placed in a 1-liter beaker, and 14.3 g (0.0
42 mol)

[0036]

[Outside 15] Was dissolved and the liquid temperature was cooled to 5 ° C, 10.8 g (0.02 mol) of the borofluoride salt obtained above was dissolved, and then 5.1 g (0.050 mol) of triethylamine was dissolved in 5 minutes. Dropped. After stirring for 2 hours, the precipitated pigment was collected by filtration, washed with dimethylformamide 4 times and water 3 times, and then freeze-dried. The yield was 19.1 g, which was 91%.

The form of the photosensitive layer of the electrophotographic photosensitive member of the present invention may be any known form, but a layer containing the disazo pigment of the present invention as a charge generating substance is used as a charge generating layer. A function-separated type photosensitive layer having a charge-transporting layer containing a charge-transporting substance laminated thereon is particularly preferable.

For the charge generation layer, the disazo pigment of the present invention is vacuum-deposited on a conductive support, or a solution prepared by dispersing the disazo pigment in a binder resin using a suitable solvent is applied on the conductive support. It can be formed by applying by a known method and drying. The film thickness is preferably 5 μm or less, and particularly preferably 0.1 to 1 μm.

The binder resin is selected from various insulating resins or organic photoconductive polymers, but it includes polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulose resin, acrylic resin, and polyurethane. Etc. are preferred. These resins may have a substituent,
As the substituent, a halogen atom, an alkyl group, an alkoxy group, a nitro group, a trifluoromethyl group, a cyano group and the like are preferable. The content of the binder resin is preferably 80% by weight or less based on the total weight of the charge generation layer,
In particular, it is preferably 40% by weight or less.

Further, the solvent is preferably selected from those which dissolve the above-mentioned resin but do not dissolve the charge transport layer and the undercoat layer described later. Specifically, ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as cyclohexanone and methyl ethyl ketone; amides such as N, N-dimethylformamide; esters such as methyl acetate and ethyl acetate; toluene, xylene and Aromatic hydrocarbon compounds such as monochlorobenzene; alcohols such as methanol, ethanol and 2-propanol; and aliphatic hydrocarbon compounds such as chloroform and methylene chloride.

The charge transport layer is laminated on or under the charge generation layer and has a function of receiving charge carriers from the charge generation layer and transporting them in the presence of an electric field. The charge transport layer can be formed by applying a solution in which a charge transport substance is dissolved in a solvent together with an appropriate binder resin, if necessary, and drying. Film thickness is 5-40 μm
Is preferable, and particularly preferably 15 to 30 μm.

The charge transport material is roughly classified into an electron transport material and a hole transport material. Examples of the electron transport material include 2,
Examples include electron-withdrawing substances such as 4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil and tetracyanoquinodimethane, and polymers obtained by polymerizing these electron-withdrawing substances. As the hole-transporting substance, polycyclic aromatic compounds such as pyrene and anthracene;
Heterocyclic compounds such as carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole and triazole; p-diethylaminobenzaldehyde-N, N-
Hydrazone compounds such as diphenylhydrazone, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole; a-phenyl-4′-N, N-diphenylaminostilbene, 5- [4- (di-p- Styryl-based compounds such as tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene; benzidine-based compounds;
Examples thereof include triarylmethane compounds; triphenylamine compounds; and polymers having groups derived from these compounds in the main chain or side chains (for example, poly-N-vinylcarbazole and polyvinylanthracene). In addition to these organic charge transport materials, inorganic materials such as selenium, selenium-tellurium, amorphous silicon and cadmium sulfide can also be used. Further, these charge transport materials may be used alone or in combination of two or more kinds.

When the charge transport material has no film forming property, a suitable binder resin can be used. Specifically, insulating resin such as acrylic resin, polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, polyamide and chlorinated rubber, or organic photoconductive material such as poly-N-vinylcarbazole and polyvinylanthracene. And the like. The content of the binder resin is preferably 20 to 90% by weight or less, particularly 40 to 70% by weight, based on the total weight of the charge transport layer.
Is preferred.

Another specific example of the present invention is an electrophotographic photosensitive member having a photosensitive layer containing the disazo pigment of the present invention and the above-mentioned charge transporting substance in the same layer. In this case, a charge transfer complex composed of poly-N-vinylcarbazole and trinitrofluorenone may be used as the charge transport material. This electrophotographic photoreceptor can be prepared by coating a conductive support with a solution prepared by dispersing and dissolving the disazo pigment and the charge transporting material in a suitable binder resin solution and drying the solution. The content of such a binder resin is based on the total weight of the photosensitive layer.
It is preferably 20 to 90% by weight, and particularly 40 to
It is preferably 70% by weight. Film thickness is 5-40 μm
Is preferable, and particularly preferably 15 to 30 μm.

In any of the electrophotographic photoreceptors, two or more kinds of the disazo pigments of the present invention can be used in combination, or can be used in combination with a known charge generating substance.

Examples of the material of the conductive support used in the present invention include aluminum, aluminum alloys, copper,
Zinc, stainless steel, vanadium, molybdenum, chrome,
Examples include titanium, nickel, indium, gold, platinum, and the like. In addition, plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) and conductive particles (for example, carbon black and silver particles) formed by coating these metals or alloys by a vacuum deposition method may be used. The above-mentioned plastic, a support coated on a metal or an alloy, or a support obtained by impregnating plastic or paper with conductive particles may be used together with an appropriate binder resin.
The shape may be a drum shape, a sheet shape, a belt shape, or the like, but a shape most suitable for the electrophotographic apparatus to be applied is preferable.

In the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support and the photosensitive layer. The thickness of the undercoat layer is preferably 5 μm or less, and particularly preferably 0.1 to 3 μm. Examples of the material of the undercoat layer include casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide and the like.

In the present invention, for the purpose of protecting the photosensitive layer from external mechanical and chemical adverse effects, etc., a resin layer as a protective layer or a resin layer containing conductive particles or a charge transport substance is used. Can also be provided on the photosensitive layer.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser beam printers, C
RT printer, LED printer, liquid crystal printer,
It can be widely used in electrophotographic application fields such as laser plate making and facsimile.

FIG. 1 shows a schematic structure of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoconductor 1 rotates during the rotation process.
The peripheral surface of the primary charging means 3 is uniformly charged with a predetermined positive or negative potential, and then image exposure light 4 from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then developed by the developing means 5.
The toner-developed toner image is developed by and is transferred to a transfer material 7 which is sent from a paper feeding unit (not shown) between the photoconductor 1 and the transfer means 6 in synchronization with the rotation of the photoconductor 1 and is expedited. The image is sequentially transferred by the means 6.

The transfer material 7 that has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 to undergo image fixing, and is printed out to the outside of the apparatus as a copy.

The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning means 9 to remove the residual toner after transfer, and further the pre-exposure light 10 from the pre-exposure means (not shown).
After being subjected to static elimination processing by, it is repeatedly used for image formation. If the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not always necessary.

In the present invention, among the constituent elements such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9, a plurality of components are integrally combined as a process cartridge, The process cartridge may be detachably attached to the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, a process in which at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoconductor 1 to form a cartridge, and which can be attached to and detached from the apparatus body by using a guide unit such as a rail 12 of the apparatus body. Cartridge 11
Can be

Further, when the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected light or transmitted light from the original, or the original is read by a sensor, converted into a signal, and the image exposure is performed according to this signal. Laser beam scanning,
It is the light emitted by the driving of the LED array and the driving of the liquid crystal shutter array.

On the other hand, when used as a printer for a facsimile, the image exposure light 4 becomes exposure light for printing received data. FIG. 2 is a block diagram showing an example of this case.

The controller 14 controls the image reading section 13 and the printer 22. The entire controller 14 is controlled by the CPU 20. The read data from the image reading unit 13 is transmitted to the partner station through the transmission circuit 16. The data received from the partner station is sent to the printer 22 through the receiving circuit 15. Predetermined image data is stored in the image memory. The printer controller 21 controls the printer 22. 17 is a telephone.

The image received from the line 18 (image information from a remote terminal connected through the line) is demodulated by the receiving circuit 15, and then the image information is decoded by the CPU 20 and sequentially stored in the image memory 19. Is stored. When the image of at least one page is stored in the image memory 19, the image of that page is recorded. CPU20
Reads one page of image information from the image memory 19 and sends the decoded one page of image information to the printer controller 21. Upon receiving the image information of one page from the CPU 20, the printer controller 21 controls the printer 22 to record the image information of the page. The CPU 20 is receiving the next page during recording by the printer 22.

In this way, the image is received and recorded.

Hereinafter, the present invention will be described in more detail with reference to Examples.

[0062]

【Example】

Example 1 A solution prepared by dissolving 5 g of methoxymethylated nylon (number average molecular weight 32,000) and 10 g of alcohol-soluble copolymer nylon (number average molecular weight 29,000) in 95 g of methanol was coated on an aluminum substrate with a wire bar and dried. By doing so, an undercoat layer having a film thickness of 1 μm was formed.

Next, 5 g of the pigment of the above Pigment Example 1 was added to a solution of 2 g of polyvinylbenzal (benzalization degree of 75% or more, number average molecular weight 80,000) dissolved in 95 g of cyclohexanone, and a sand mill was used for 20 hours. Dispersed. Apply this dispersion on the undercoat layer with a wire bar,
By drying, a charge generation layer having a thickness of 0.2 μm was formed.

Next, 5 g of a styryl compound represented by the following formula

[0065]

[Outside 16] And polycarbonate (number average molecular weight 55,000) 5g
A solution in which 40 g of chlorobenzene was dissolved was applied onto the charge generation layer with a wire bar and dried to form a charge transport layer having a thickness of 20 μm.

The obtained electrophotographic photosensitive member was subjected to -5 by using an electrostatic copying paper test device (SP-428, manufactured by Kawaguchi Electric Co., Ltd.).
The charging characteristics were evaluated by negatively charging with a KV corona discharge, holding for 1 second in a dark place, and then exposing with halogen light having an illuminance of 10 lux. As the charging characteristics, the surface potential V ₀ immediately after charging and the surface potential after leaving in a dark place for 1 second are 1
Exposure required to attenuate to 1/2, ie sensitivity (1/2)
Was measured. The results are shown in Table 1.

Examples 2 to 10 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the disazo pigments shown in Table 1 were used in place of Pigment Example 1. The results are shown in Table 1.

[0068]

[Table 1]

Comparative Examples 1 and 2 Instead of the disazo pigment of Pigment Example 1, the following comparative pigments A and B were used.
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that was used. The results are shown in Table 2.

Comparative Pigment A (Disazo pigment described in JP-A-60-57348)

[0071]

[Outside 17] Comparative pigment B (disazo pigment described in JP-A-60-57348)

[0072]

[Outside 18]

[0073]

[Table 2]

Example 11 An electrophotographic copying machine equipped with the electrophotographic photosensitive member prepared in Example 1 was equipped with a -6.5 KV corona charger, an exposure optical system, a developing device, a transfer charger, a static elimination exposure optical system and a cleaner. I stuck it on the cylinder.

The initial dark portion potential V _D and the light portion potential _VL are set near -700 V and -200 V, respectively, and 5,000 is set.
Durability was evaluated by repeating repeated use, and measuring the variation amount ΔV _D of the dark portion potential and the variation amount ΔV _L of the bright portion potential after the initial use and after the repeated use. The results are shown in Table 3. The negative sign of the fluctuation amount of the electric potential indicates that the absolute value of the electric potential has decreased, and the positive sign indicates that the absolute value of the electric potential has increased.

Examples 12 to 15 Example 6 was used instead of the electrophotographic photosensitive member prepared in Example 1.
Durability was evaluated in the same manner as in Examples except that the electrophotographic photoreceptors prepared in Nos. 7, 9 and 10 were used. The results are shown in Table 3.

[0077]

[Table 3]

Comparative Examples 3 and 4 Example 1 was repeated except that the electrophotographic photosensitive members prepared in Comparative Examples 1 and 2 were used in place of the electrophotographic photosensitive member prepared in Example 1.
Durability was evaluated in the same manner as 1. The results are shown in Table 4.

[0079]

[Table 4]

Example 16 An undercoat layer of polyvinyl alcohol (number average molecular weight: 22,000) having a thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film.

On this undercoat layer, 5 g of the pigment of Pigment Example 8 was added to a solution of 95 g of cyclohexanone and 2 g of butyral resin (degree of butyralization: 63 mol%, number average degree of polymerization: 2,000) dissolved, and a sand mill was used. By applying the dispersion liquid dispersed for 20 hours and drying, the film thickness becomes 0.2.
A 0 μm charge generation layer was formed.

Then, 5 g of a hydrazone compound represented by the following formula

[0083]

[Outside 19] And polymethylmethacrylate (weight average molecular weight 100,
A solution of 5 g of 000) dissolved in 40 g of tetrahydrofuran was applied on the charge generation layer and dried to form a charge transport layer having a thickness of 20 μm.

The charging characteristics and durability of the obtained electrophotographic photosensitive member were evaluated in the same manner as in Examples 1 and 11. The results are shown below. _{V 0: -690V, E 1/2:} 0.8lux · sec ΔV D: -10V, ΔV L: + 20V

Example 17 An undercoat layer of polyvinyl alcohol (number average molecular weight 22,000) having a thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film.

On top of this subbing layer 5 g of pigment of Pigment example 8
Was added to a solution of 2 g of poly-p-fluorovinylbenzal (degree of benzalization of 75 mol% or more, number average molecular weight 90,000) dissolved in 95 g of tetrahydrofuran, and the dispersion liquid was dispersed for 20 hours using a sand mill to apply the dispersion liquid. By drying, a charge generation layer having a film thickness of 0.20 μm was formed.

Then, 5 g of a triarylamine compound having the following formula

[0088]

[Outside 20] And polycarbonate (weight average molecular weight 55,000) 5
A solution in which 40 g of chlorobenzene was dissolved was applied onto the charge generation layer and dried to form a charge transport layer having a thickness of 20 μm.

The charging characteristics and durability of the obtained electrophotographic photosensitive member were evaluated in the same manner as in Examples 1 and 11. The results are shown below. _{V 0: -700V, E 1/2:} 0.8lux · sec ΔV D: -5V, ΔV L: + 5V

Example 18 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 17, except that the charge generation layer and the charge transport layer were formed in the reverse order. However, the polarity of charging was positive. The results are shown below. V ₀ : + 710V, E _1/2 : 2.1lux · sec ΔV _D : + 10V, ΔV _L : + 20V

Example 19 A charge generation layer was formed in the same manner as in Example 1. next,
A solution prepared by dissolving 5 g of 2,4,7-trinitro-9-fluorenone and 5 g of polycarbonate (weight average molecular weight of 30,000) in 50 g of tetrahydrofuran was applied on the charge generation layer with a wire bar and dried,
A charge transport layer having a thickness of 18 μm was formed. The obtained electrophotographic photosensitive member was evaluated in the same manner as in Example 1. However, the polarity of charging was positive. The results are shown below. V ₀ : + 690V, E _1/2 : 2.5lux · sec

Example 20 A solution prepared by adding 0.5 g of the disazo pigment of Pigment Example 10 to 9.5 g of cyclohexanone was dispersed with a paint shaker for 5 hours. The charge transport material 5 used in Example 1 was added to this dispersion.
g and polycarbonate (weight average molecular weight 80,000)
A solution prepared by dissolving 5 g in 40 g of tetrahydrofuran was added, and the mixture was further shaken for 1 hour. The obtained solution was applied onto an aluminum substrate with a wire bar and dried to form a photosensitive layer having a film thickness of 20 μm. The obtained electrophotographic photosensitive member was evaluated in the same manner as in Example 1. However, the polarity of charging was positive. The results are shown below. V ₀ : + 695V, E _1/2 : 2.6lux · sec

[0093]

As described above, according to the present invention, an electrophotographic photoreceptor having high sensitivity and stable and excellent potential characteristics even after repeated use, and a process cartridge having the electrophotographic photoreceptor. Also, an electrophotographic apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram showing an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of the present invention 2 Axis 3 Primary charging means 4 Image exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Rail 13 Image reading section 14 Controller 15 Receiver circuit 16 Transmitter circuit 17 Telephone 18 Line 19 Image memory 20 CPU 21 Printer controller 22 Printer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Country ▼ Mitsuhiro Eda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer has the following formula (1): (In the formula, R ₁ and R ₂ are the same or different and each is a hydrogen atom,
A halogen atom, an alkyl group, an alkoxy group, and a cyano group are shown, A ₁ and A ₂ are the same or different and each represents a coupler residue having a phenolic hydroxyl group, and at least one of A ₁ and A ₂ is represented by the following formula (2): Outside 2] (In the formula, X ₁ represents a residue necessary for forming a polycyclic aromatic ring or a heterocyclic ring by being condensed with a benzene ring, and R ₃ and R ₄
Are the same or different and represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a heterocyclic group and a residue forming a cyclic amino group by bonding with each other, and Z ₁ represents an oxygen atom or a sulfur atom. ) Is a coupler residue. ] The electrophotographic photoreceptor containing the disazo pigment shown by these. _2. The electrophotographic photosensitive member according to claim 1, wherein all of R ₁ and R ₂ are hydrogen atoms. 3. The formula (1) is the following formula: The electrophotographic photosensitive member according to claim 1, wherein A ₁ and A ₂ have the same meanings as in formula (1). 4. The electrophotographic photosensitive member according to claim 1, wherein both A ₁ and A ₂ are a coupler residue represented by the formula (2). 5. The electrophotographic photosensitive member according to claim 1, wherein X ₁ is a residue necessary for condensing with a benzene ring to form a benzocarbazole ring. 6. The photosensitive layer has a charge generating layer containing a disazo pigment represented by the formula (1) as a charge generating substance and a charge transporting layer, and the electrophotographic photoreceptor has the charge generating layer on a conductive support. The electrophotographic photoreceptor according to claim 1, further comprising a layer, and the charge transporting layer on the charge generating layer. 7. The electrophotographic photosensitive member according to claim 1, and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit are integrally supported and can be attached to and detached from the main body of the electrophotographic apparatus. Process cartridge characterized in that. 8. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.