JPH0954448A - Electrophotographic photoreceptor, process cartridge with the same and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high sensitivity and stable potential characteristics at the repetitive use by incorporating a trisazo pigment represented by a specified formula into a photosensitive layer. SOLUTION: A photosensitive layer contg. a trisazo pigment represented by formula I is disposed on an electrically conductive substrate. The efficiency of generation and injection of electric charge carriers in the photosensitive layer is enhanced and such characteristics as superior sensitivity and superior potential stability at the repetitive use are ensured. In the formula I, Cp is a residue of a coupler represented by formula II, III, etc. In the formulae II, III, each of X1 and X2 is a residue required to form a polycyclic arom. ring or a hetero ring by condensation with a benzene ring, each of Z1 and Z2 is O or S, each of R1 -R4 is H, alkyl which may have a substituent, a carbocyclic arom. group or a heterocyclic arom. group, (m) is 1 or 2 and (n) is 0, 1 or 2. The photosensitive layer is preferably a laminate type photosensitive layer formed by laminating an electric charge generating layer contg. the trisazo pigment and an electric charge transferring layer.

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 a process cartridge equipped with the electrophotographic photoreceptor.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been widely used as electrophotographic photoreceptors. On the other hand, as an electrophotographic photoreceptor using an organic photoconductive substance, poly-N-vinylcarbazo-
Photoconductive polymer typified by polymer and 2,5-bis- (p
-Diethylaminophenyl) -1,3,4-oxadiazol, a low molecular weight photoconductive substance, and a combination of such an organic photoconductive substance with various dyes and pigments. Are known. An electrophotographic photoreceptor using an organic photoconductive substance has good film-forming properties and can be produced by coating. Therefore, it has an advantage of being able to provide an electrophotographic photoreceptor that has extremely high productivity and is inexpensive. In addition, the color sensitivity can be freely controlled by selecting the dyes and pigments to be used.
It has the advantage that it can be downloaded, and has been extensively studied so far. In particular, recently, due to the development of a function-separated type photoreceptor in which a charge transport layer containing an organic photoconductive polymer or a photoconductive substance of a low molecular weight is laminated, the sensitivity which has been regarded as a defect of the conventional organic electrophotographic photoreceptor is detected. And durability has been remarkably improved.

A large number of compounds have been proposed so far because azo pigments exhibit excellent photoconductivity and compounds having various characteristics can be easily obtained by combining the azo component and the coupler component. However, electrophotographic photoreceptors using conventional azo pigments are not always sufficient in terms of sensitivity and potential stability during repeated use, and only very few materials have been put to practical use. is there.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel photoconductive material, and an electrophotographic photoreceptor having excellent high sensitivity characteristics and stable potential characteristics upon repeated use. The present invention provides a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

[0005]

The present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains a trisazo pigment represented by the general formula (1). It is composed of a photographic photoreceptor. General formula (1)

Embedded image In the formula, Cp is a coupler represented by the following general formulas (2) to (8).
Represents a residue selected from the group consisting of residues. General formula (2)

Embedded image General formula (3)

Embedded image General formula (4)

[Chemical 12] General formula (5)

Embedded image General formula (6)

Embedded image General formula (7)

Embedded image General formula (8)

Embedded image Wherein, X ₁ to X ₅ represents a residue necessary to form a polycyclic aromatic or heterocyclic ring condensed with a benzene ring, Z ₁ ~
Z ₃ represents an oxygen atom or a sulfur atom, R _{1 to} R _{10 each} represent a hydrogen atom, an alkyl group which may have a substituent, a carbocyclic aromatic group which may have a substituent, or a substituent. Represents a heterocyclic aromatic group which may be represented by R ₁ , R ₂ , R
₃ and R ₄ , R ₇ and R ₈ may be bonded to each other to form a ring with a nitrogen atom, R ₉ and R ₁₀ may be bonded to each other to form a ring with a carbon atom, and m is 1 Or an integer of 2, n is an integer of 0, 1 or 2, and Y in the general formula (5) is a divalent aromatic hydrocarbon group which may have a substituent or a nitrogen atom in the ring. Represents a divalent heterocyclic group included in

Examples of the polycyclic aromatic ring or heterocyclic ring in X _{1 to} X ₅ include naphthalene ring, anthracene ring, carbazol ring, benzcarbazol ring, dibenzofuran ring and the like, and in R _{1 to} R ₁₀ , alkyl is used. Examples of the group include groups such as methyl, ethyl and propyl, examples of the carbocyclic aromatic group include groups such as phenyl, naphthyl, anthryl, benzyl and phenethyl, and examples of the heterocyclic aromatic group include pyridyl and thionyl. , Thiazolyl, carbazoyl, benzimidazolyl, benzothiazolyl, etc., and the ring formed with the nitrogen atom is pyrrole,
Examples thereof include pyrroline, pyridine, indole, imidazole, pyrazol, pyrazoline, oxazine, and phenoxazine, and examples of the ring formed with a carbon atom include fluorene, anthraquinone, xanthone, 1-indanone, and the like. , The substituents in these groups include an alkyl group such as methyl, ethyl and propyl, a fluorine atom,
Halogen atom such as chlorine atom, bromine atom, iodine atom, acyl group such as acetyl and benzyl, alkylamino group such as dimethylamino and diethylamino, phenylcarbamoyl group, nitro group, cyano group, haloalkyl group such as trifluoromethyl, etc. Can be mentioned. In Y, the divalent aromatic hydrocarbon group which may have a substituent or the divalent heterocyclic group containing a nitrogen atom in the ring is o-phenylene,
o-naphthylene, perinaphthylene, 1,2-anthrylene, 3,4-pyrazole-diyl, 2,3-pyridinediyl, 4,5-pyridinediyl, 6,7-indazoldiyl, 6,7-quinolinediyl and the like 2 Examples of the substituents in these groups include a methyl group, an ethyl group, an alkyl group such as propyl group, a fluorine atom, a chlorine atom,
Halogen atom such as bromine atom, iodine atom, alkyl group such as methyl, ethyl and propyl, alkoxy group such as methoxy and ethoxy, alkylamino group such as dimethylamino and diethylamino, phenylcarbamoyl group, nitro group,
Examples thereof include a cyano group and a haloalkyl group such as trifluoromethyl.

The general formulas (2), (3), (6) to
In (8), the trisazo pigment represented by the general formula (1) in the case where X _{1 to} X ₅ are a coupler residue which is bonded to a benzene ring to form a benzcarbazole ring, has a near absorption region. Since it spreads to near the infrared region, it is also suitable as a charge generation material for semiconductor lasers.

Specific examples of the trisazo pigment represented by the general formula (1) used in the present invention are listed in Tables 1 to 3.
The trisazo pigment used in the present invention is not limited to these. Examples of pigments are described in formula (1)
In the basic type of the trisazo pigment shown in, the specific structure of the entire pigment is represented by describing only the changed portion.

[Table 1]

[Table 2]

In the trisazo pigment represented by the general formula (1) used in the present invention, the corresponding amine is hexazotized by a conventional method and coupled with the coupler in an aqueous system in the presence of an alkali, or the hexazonium salt is converted into a borofluoride salt or After conversion to a zinc chloride double salt and the like and isolation, the coupler and the coupler are capped in the presence of a base such as soda acetate, triethylamine and N-methylmorpholine in an organic solvent such as N, N-dimethylformamide and dimethylsulfoxide. It can be easily synthesized by ringing. The corresponding amine can be synthesized, for example, by the following method.

Embedded image

Synthetic Example of Trisazo Pigment (Synthesis of Pigment Example 5) 300 ml Beaker, 150 ml of water, 20 ml of concentrated hydrochloric acid
(0.23 mol) and the following amine compound 11.0 g (0.
032 mol),

Embedded image After cooling to 0 ° C., 4.6 g of sodium nitrite was added to this solution.
A solution prepared by dissolving (0.067 mol) in 10 ml of water was added dropwise over 10 minutes while maintaining the liquid temperature at 5 ° C or lower. After stirring for 15 minutes, carbon filtration was performed, and a solution prepared by dissolving 10.5 g (0.096 mol) of sodium borofluoride in 90 ml of water was added dropwise to this solution with stirring, and the precipitated borofluoride salt was filtered. It was taken, washed with cold water, washed with acetonitrile, and dried under reduced pressure at room temperature. Yield 16.3 g, 85% yield.

Next, 500 ml of N, N-dimethylformamide was placed in a 1-liter beaker, and 19.4 g (0.063 mol) of coupler having the following structural formula was added.

Embedded image Was dissolved and the liquid temperature was cooled to 5 ° C., 12.0 g (0.020 mol) of the borofluoride salt obtained above was dissolved, and then 5.1 g (0.050 mol) of triethylamine was added dropwise over 5 minutes. did. After stirring for 2 hours, the precipitated pigment is collected by filtration,
After washing 4 times with N, N-dimethylformamide and 3 times with water, it was freeze-dried. The yield was 23.9 g and the yield was 93%.

The electrophotographic photosensitive member of the present invention has a photosensitive layer containing a trisazo pigment represented by the general formula (1) on a conductive support. The form of the photosensitive layer may be any known form, but a photosensitive layer containing the trisazo pigment represented by the general formula (1) is used as a charge generating layer, and a charge transporting layer containing a charge transporting substance is added to the photosensitive layer. A laminated type photosensitive layer in which functionally separated layers are laminated is particularly preferable.

The charge generation layer can be formed by applying a coating solution prepared by dispersing the above-mentioned trisazo pigment together with a binder resin in a suitable solvent onto a conductive support by a known method to obtain a film thickness thereof. Is, for example, 5 μm or less,
It is preferable that the thin film layer has a thickness of 0.1 to 1.0 μm.

The binder resin used at this time is selected from a wide range of insulating resins or organic photoconductive polymers, but polyvinyl butyral optionally having a substituent,
Polyvinylbenzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulosic resin, acrylic resin, polyurethane and the like are preferable, and as the substituent, an alkyl group such as methyl, ethyl and propyl,
Halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom, acyl group such as acetyl and benzyl, alkylamino group such as dimethylamino, phenylcarbamoyl group, nitro group, cyano group, haloalkyl group such as trifluoromethyl, etc. Is mentioned. The content of the binder resin in the charge generation layer is 80% by weight or less, preferably 4%.
It is 0% by weight or less. The solvent used 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, tetrahydrofuran (THF), ethers such as 1,4-dioxane, cyclohexanone, methyl ethyl ketone (MEK)
Ketones such as N, N-dimethylformamide (DM
F) etc. amines, methyl acetate, ethyl acetate etc. esters, toluene, xylene, chlorobenzene etc. aromatics, methanol, ethanol, 2-propanol etc. alcohols, chloroform, methylene chloride, dichloroethylene, tetra Examples thereof include aliphatic halogenated hydrocarbons such as carbon chloride and trichlorethylene.

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 in the presence of an electric field and transporting them. The charge transporting layer is formed by dissolving a charge transporting material in a solvent together with a suitable binder resin as required and applying the solution. The film thickness is generally 5 to 40 μm, but 15 to 30 μm.
Is preferred.

The charge transport material includes an electron transport material and a hole transport material, and examples of the electron transport material include 2,
Examples thereof 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, carbazole type, indole type, imidazole type, oxazole type, thiazole type, oxadiazol type, pyrazole type , Pyrazoline type, thiadiazole type, triazo type
Heterocyclic compounds such as ruthenium compounds, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, N, N
-Hydrazone compounds such as diphenylhydrazino-3-methylidene-9-ethylcarbazol, α-phenyl-
4'-N, N-diphenylaminostilbene, 5- [4
-(Di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene and other styryl compounds, benzidine compounds, triarylmethane compounds, tri (p-tolyl) amine, 2- [di (p -Tolyl)] aminobiphenyl, 1- [di (p-tolyl)] aminopyrene and other triarylamine compounds, or
Examples thereof include polymers having groups consisting of these compounds in the main chain or side chains (for example, poly-N-vinylcarbazole, polyvinylanthracene, etc.). 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 substances can be used alone or in combination of two or more.

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, chlorinated rubber or organic photoconductive material such as poly-N-vinylcarbazole or polyvinylanthracene. Examples thereof include polymers.

Examples of the conductive support on which the photosensitive layer is formed include aluminum, aluminum alloys, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold and platinum. In addition, a plastic or metal substrate in which a plastic (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) or conductive particles (for example, carbon black, silver particles, etc.) obtained by vacuum deposition of such a metal or alloy together with an appropriate binder resin is used. It is possible to use a support coated on the above or a support obtained by impregnating plastic or paper with conductive particles.

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

Another specific example of the present invention is an electrophotographic photoreceptor containing the above-mentioned trisazo pigment and a charge transport material in the same layer. At this time, a charge transfer complex composed of poly-N-vinylcarbazole and trinitrofluorenone can be used as the charge transport material. The electrophotographic photosensitive member of this example can be formed by applying a liquid in which the above-mentioned trisazo pigment and the charge transfer complex are dispersed in an appropriate resin solution and then drying.

The crystal form of the trisazo pigment represented by the general formula (1), which is a pigment used in any electrophotographic photoreceptor, may be amorphous or crystalline, and if necessary, it may be a general form. It is also possible to use two or more trisazo pigments represented by the formula (1) in combination, or to use them in combination with a known charge generating substance.

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

Further, the present invention integrally supports the electrophotographic photosensitive member of the present invention and at least one means selected from the group consisting of charging means, developing means and cleaning means, and the electrophotographic apparatus main body It is composed of a process cartridge characterized by being detachable.

The present invention also comprises an electrophotographic apparatus having the electrophotographic photoreceptor of the present invention, a charging means, an image exposing means, a developing means and a transferring means.

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 photoreceptor of the present invention, which is driven to rotate at a predetermined peripheral speed in the direction of an arrow around a flick 2. In the rotation process, the photosensitive member 1 is uniformly charged at a predetermined positive or negative potential on the peripheral surface thereof by the primary charging means 3, and then the image exposure means (such as a slit exposure or a laser beam scanning exposure) is used. (See FIG. 1). Thus, an electrostatic latent image is 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 developed and developed by the transfer material 7 is fed from a sheet feeding unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1. Then, the image is sequentially transferred by the transfer means 6. The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out as a copy (copy) outside the apparatus. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the transfer residual toner by the cleaning means 9, and further subjected to a static elimination process by the pre-exposure light 10 from the pre-exposure means (not shown). After that, it is repeatedly used for image formation. When the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not necessarily required.

In the present invention, a plurality of constituent elements such as the photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 are integrally combined as a process cartridge. However, the process cartridge may be detachably attached to the main body of the electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging means 3, the developing means 5 and the cleaning means 9 is integrally supported together with the photoconductor 1 to form a cartridge, and a guide means such as a rail 12 of the apparatus main body is used. The process cartridge 11 can be detachably attached. When the electrophotographic apparatus is a copier or a printer, the image exposure light 4 uses reflected light or transmitted light from the original, or reads the original with a sensor and converts it into a signal. This is light emitted by scanning of the laser beam, driving of the LED array, driving of the liquid crystal shutter array, and the like.

On the other hand, when used as a printer for a facsimile, the image exposure light 4 becomes exposure light for printing the received data. FIG. 2 is a block diagram showing an example of this case. The controller 14 controls the image reading unit 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 the remote terminal connected via 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. To be done. When the image of at least one page is stored in the image memory 19, the image of the page is recorded. The CPU 20 reads out the image information of one page from the image memory 19 and sends out the decoded image information of one page to the printer-controller-21. When 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. CPU 20
Is receiving the next page during recording by the printer-22. In this way, the image is received and recorded.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic photosensitive member of the present invention is manufactured, for example, as follows.

A liquid in which a nylon resin was dissolved in a solvent was coated on an aluminum support with a Mayer bar and dried to form an undercoat layer. Next, the trisazo pigment of Pigment Example 1 was used as a charge-generating substance in cyclohexanone in polyvinyl. A liquid in which benzal was dissolved was added, the mixture was dispersed by a sand mill, the prepared dispersion was applied on the undercoat layer previously formed with a Mayer bar and dried to form a charge generation layer, and then the charge generation layer was formed. A solution prepared by dissolving a styryl compound as a transport material and a polycarbonate Z resin in chlorobenzene is applied on the charge generation layer with a Mayer bar and dried to form a charge transport layer. The electrophotographic photosensitive member can be produced.

Further, the electrophotographic photosensitive member may be provided with a process cartridge in which a primary charging means, a developing means and a cleaning means are integrally supported as shown in FIG.

As shown in FIG. 2, as an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention, for example, a printer can be used as a printer in a facsimile.

[0033]

【Example】

Examples 1 to 10 A solution prepared by dissolving 5 g of methoxymethylated nylon resin (average molecular weight 32000) and 10 g of alcohol-soluble copolymerized nylon resin (average molecular weight 29000) in 95 g of methanol was applied on an aluminum support with a Mayer bar. Then, an undercoat layer having a film thickness after drying of 1 μm was formed.

Next, 5 g of the trisazo pigment of Pigment Example 1 was dissolved in 95 g of cyclohexanone and 2 g of polyvinylbenzal (having a benzalization degree of 75 mol% or more) was added, and the mixture was dispersed in a sand mill for 20 hours. This dispersion was applied onto the previously formed undercoat layer with a Mayer bar so that the film thickness after drying would be 0.2 μm to form a charge generation layer.

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

Embedded image And polymethyl methacrylate (number average molecular weight 10,000
0) 5 g was dissolved in 40 g of chlorobenzene, and this solution was applied onto the charge generation layer with a Mayer bar and dried to 20 μm.
m was formed, and an electrophotographic photoreceptor of Example 1 was prepared.

Instead of the trisazo pigment of Pigment Example 1, other pigments were used to prepare electrophotographic photoreceptors corresponding to Examples 2 to 10 in exactly the same manner.

The electrophotographic photoconductors prepared in Examples 1 to 10 were manufactured by Kawaguchi Electric Co., Ltd., and an electrostatic copying paper tester Model was used.
After using SP-428 to negatively charge by corona discharge of -5 KV, leaving it in a dark place for 1 second, it was exposed to light with an illuminance of 10 lux using a halogen lamp to evaluate the charging characteristics. As the charging characteristics, the surface potential V ₀ and the exposure amount E _1/2 required for the surface potential after being left in the dark to be attenuated to _1/2 were measured.
The results are shown in Table 3.

[Table 3]

Comparative Examples 1 and 2 Electrons corresponding to Comparative Examples 1 and 2 were prepared in the same manner as in Example 1 except that the trisazo pigments used in Example 1 were replaced with comparative pigments 1 and 2 represented by the following structural formula. A photographic photoreceptor was prepared and the charging characteristics were evaluated in the same manner. The results are shown. Comparative pigment 1

[Chemical 21] Comparative pigment 2

Embedded image Comparative Example 1 V ₀ : −670V, E _1/2 : 3.40 lux · sec Comparative Example 2 V ₀ : −665V, E _1/2 : 4.27 lux · sec

From these results, it is known that the electrophotographic photosensitive member of the present invention has sufficient charging ability and excellent sensitivity.

Examples 11 to 13 The electrophotographic photosensitive member prepared in Example 2 is 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. It was attached to the cylinder of the electrophotographic copying machine. Initial dark potential V _D and bright potential V
Set _L to around -700V and -200V respectively, and
Variation of dark area potential after repeated use 000 times ΔV _D
And the variation ΔV _L of the bright part potential were measured. Examples 5 and 9
The electrophotographic photoreceptor prepared in 1. was evaluated in the same manner.
The results are shown. Note that a negative sign in the potential fluctuation indicates a decrease in the absolute value of the potential, and a positive sign indicates an increase in the absolute value of the potential. Example _{11 △ V D: + 5V,} △ V L: + 5V Example _{12 △ V D: -5V, △} V L: + 10V Example _{13 △ V D: 0V, △} V L: + 5V

Comparative Example 3 Regarding the electrophotographic photosensitive member prepared in Comparative Example 1, Example 1
The amount of potential fluctuation during repeated use was measured by the same method as in 1. The results are shown. Comparative Example _{3 △ V D: -50V, △} V L: + 25V

From the above results, it is known that the electrophotographic photosensitive member of the present invention has little potential fluctuation during repeated use.

Example 14 An undercoat layer of polyvinyl alcohol having a film thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. Onto this, 5 g of the trisazo pigment of Pigment Example 2 was added to 95 g of cyclohexanone dissolved in 2 g of butyral resin (degree of butyralization: 63 mol%), and the dispersion prepared in the same manner as in Example 1 was applied and dried. Then, the film thickness of 0.
A 2 μm charge generation layer was formed.

Then, 5 g of a hydrazone compound having the following structural formula

Embedded image And polycarbonate (weight average molecular weight 55000) 5 g
Was dissolved in 40 g of tetrahydrofuran and applied onto the charge generation layer and dried to form a 20 μm-thick charge transport layer. The charging characteristics and the durability characteristics of the produced electrophotographic photosensitive member were measured by the same methods as in Examples 1 and 11. The results are shown. _{V 0: -705V, E 1/2:} 1.34 lux-seconds _{ΔV D: -5V, ΔV L:} + 10V

Example 15 An undercoat layer of polyvinyl alcohol having a film thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. On top of this, 5 g of the trisazo pigment of Pigment Example 2 was added to 95 g of tetrahydrofuran to obtain poly-p-fluorovinylbenzal (degree of benzalization of 75 mol% or more) 2.
g was added to the dissolved solution, and the dispersion prepared in the same manner as in Example 1 was applied and dried to form a charge generation layer having a film thickness of 0.2 μm.

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

Embedded image And polycarbonate (weight average molecular weight 55000) 5 g
Was dissolved in 40 g of chlorobenzene and applied on the charge generation layer and dried to form a charge transport layer having a thickness of 20 μm. The charging characteristics and the durability characteristics of the produced electrophotographic photosensitive member were measured by the same methods as in Examples 1 and 11. The results are shown. _{V 0: -700V, E 1/2:} 1.30 lux-seconds _{ΔV D: -5V, ΔV L:} + 5V

Example 16 An electrophotographic photosensitive member was prepared by coating the charge generation layer and the charge transport layer of the electrophotographic photosensitive member prepared in Example 1 in the reverse order, and charged in the same manner as in Example 1. The characteristics were evaluated.
However, the charging was positive. The results are shown. V ₀ : + 675V, E _1/2 : 3.25 lux ・ sec

Example 17 On the charge generation layer prepared in Example 1, 5 g of 2,4,7-trinitro-9-fluorenone and poly-4,4'-dioxydiphenyl-2,2-propanecarbonate were added. A solution prepared by dissolving 5 g of (molecular weight 300000) in 50 g of tetrahydrofuran was applied with a Mayer bar, and the film thickness after drying was 18 μm.
m charge transport layer was formed. The charging characteristics of the produced electrophotographic photosensitive member were evaluated in the same manner as in Example 1. However, the charging was positive. The results are shown. V ₀ : + 665V, E _1/2 : 4.08 lux ・ sec

Example 18 0.5 g of Pigment Example 2 was dispersed with 9.5 g of cyclohexanone in a paint shaker for 5 hours. Example 1 here
5 g of the same charge transport material and polycarbonate 5 used in
A solution prepared by dissolving 40 g of tetrahydrofuran in 40 g was added, and the mixture was further shaken for 1 hour. The coating solution thus prepared was applied to an aluminum support with a Myer bar and dried to form a film having a thickness of 20 μm.
m of the photosensitive layer was formed. The charging characteristics of the produced electrophotographic photosensitive member were evaluated in the same manner as in Example 1. However, the charging was positive. The results are shown. V ₀ : + 650V, E _1/2 : 2.26 lux ・ sec

[0050]

INDUSTRIAL APPLICABILITY In the electrophotographic photoreceptor of the present invention, by using the trisazo pigment having a specific structure in the photosensitive layer, either one or both of the charge carrier generation efficiency and the injection efficiency in the photosensitive layer is improved, A remarkable effect is obtained that excellent characteristics such as sensitivity and potential stability at the time of repeated use are obtained, and also a similar effect is obtained in a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[Brief description of drawings]

FIG. 1 is a process car having an electrophotographic photoreceptor of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a cartridge.

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

[Explanation 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 Rails 13 Image reading unit 14 Controller 15 Receiver circuit 16 Transmitter circuit 17 Telephone 18 Line 19 Image memory 20 CPU 21 Printer-Controller 22 Printer-

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains a trisazo pigment represented by the general formula (1). General formula (1) In the formula, Cp is a coupler represented by the following general formulas (2) to (8).
Represents a residue selected from the group consisting of residues. General formula (2) General formula (3) General formula (4) General formula (5) General formula (6) General formula (7) General formula (8) Wherein, X ₁ to X ₅ represents a residue necessary to form a polycyclic aromatic or heterocyclic ring condensed with a benzene ring, Z ₁ ~
Z ₃ represents an oxygen atom or a sulfur atom, R _{1 to} R _{10 each} represent a hydrogen atom, an alkyl group which may have a substituent, a carbocyclic aromatic group which may have a substituent, or a substituent. Represents a heterocyclic aromatic group which may be represented by R ₁ , R ₂ , R
₃ and R ₄ , R ₇ and R ₈ may be bonded to each other to form a ring with a nitrogen atom, R ₉ and R ₁₀ may be bonded to each other to form a ring with a carbon atom, and m is 1 Or an integer of 2, n is an integer of 0, 1 or 2, and Y in the general formula (5) is a divalent aromatic hydrocarbon group which may have a substituent or a nitrogen atom in the ring. Represents a divalent heterocyclic group included in 2. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has at least two layers of a charge generating layer containing the trisazo pigment represented by the general formula (1) and a charge transporting layer. 3. The electrophotographic photosensitive member according to claim 1, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably attached to the main body of the electrophotographic apparatus. A process cartridge characterized by the following. 4. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposure unit, a developing unit and a transfer unit.