JPH0566591A - Electrophotographic sensitive body and electrophotographic device and facsimile having this electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an excellent high-sensitivity characteristic and stable potential characteristic at the time of repeatable use and to improve the efficiency of generating and implanting charge carriers in a photosensitive layer by incorporating a specific disazo pigment into the photosensitive layer on a conductive base. CONSTITUTION:This photosensitive body has the photosensitive layer contg. the disazo pigment expressed by formula I on the conductive base. In the formula I, D denotes the structure expressed by formula II, etc.; A1 and A2 denote the coupler residues expressed by formula III, etc., but either of A1 and A2 is the coupler residue expressed by the formula III. In the formula II, Y1 to Y8 denote a hydrogen atom, cyano group, alkyl group, carbon cyclic arom. group, heterocyclic arom. group; B1 and B2 denote a hydrogen atom, cyano group, carbon cyclic arom. group, heterocyclic arom. group. In the formula III, X1 denotes the residue necessary for forming a polycylic arom. ring or heterocycle by condensing with a benzene ring; Z1 denotes an oxygen atom or sulfur atom; R1, R2 denote a hydrogen atom, alkyl group, carbon cyclic arom. group or heterocyclic arom. group.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member containing a disazo pigment having a specific structure in a photosensitive layer, an electrophotographic apparatus equipped with the electrophotographic photosensitive member, and a facsimile.

[0002]

2. Description of the Related Art Heretofore, inorganic photoconductive substances such as selenium, cadmium sulfide and zinc oxide have been widely used as electrophotographic photoreceptors. On the other hand, as an electrophotographic photosensitive member made of an organic photoconductive substance, poly-N-vinylcarbazo-
Photoconductive polymer represented by a polymer and 2,5-bis (p-
Using a low molecular weight organic photoconductive substance such as diethylaminophenyl) -1,3,4-oxadiazol,
Further, a combination of such an organic photoconductive substance and various dyes and pigments is known. An electrophotographic photoreceptor using an organic photoconductive substance has a good film-forming property and can be produced by coating. Therefore, it has an advantage of being able to provide an inexpensive photoreceptor having extremely high productivity. Further, it has an advantage that the color sensitivity can be freely controlled by selecting the dye or pigment to be used, and a wide range of studies have been conducted so far. In particular, recently, the development of a function-separated photoreceptor in which a charge generation layer containing an organic photoconductive dye or pigment and a charge transport layer containing the above-mentioned photoconductive polymer or a low molecular weight organic photoconductive substance are laminated. As a result, the sensitivity and durability, which have been the drawbacks of conventional organic electrophotographic photoreceptors, have been remarkably improved.

Azo pigments have excellent photoconductivity and, in addition, compounds having various characteristics can be obtained relatively easily by combining the azo component and the coupler component. Proposed. However, conventional electrophotographic photoreceptors using disazo 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]

The object of the present invention is to provide a novel photoconductive material, and to provide an electrophotographic photoreceptor having excellent high sensitivity characteristics and stable potential characteristics upon repeated use, An object of the present invention is to provide an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member.

[0005]

The present invention comprises an electrophotographic photosensitive member characterized by having a photosensitive layer containing a disazo pigment represented by the following general formula (1) on a conductive support. In the general formula _{(1) A 1 -N = N} -D-N = N-A 2 formula, D is represents any one of structures represented by the following general formula (1-1) ~ (1-7), A 1 And A ₂ represent any of the coupler residues represented by the following general formulas (2) to (8), provided that _one of A ₁ and A ₂ is the coupler residue represented by the general formula (2). General formula (1-1)

[Chemical 15] General formula (1-2)

[Chemical 16] General formula (1-3)

[Chemical 17] General formula (1-4)

[Chemical 18] General formula (1-5)

[Chemical 19] General formula (1-6)

[Chemical 20] General formula (1-7)

[Chemical 21] In the formula, Y _{1 to} Y ₅₄ represent a hydrogen atom, a cyano group, a halogen atom, an optionally substituted alkyl group, a carbocyclic aromatic group or a heterocyclic aromatic group, and B ₁ and B ₂ Represents a hydrogen atom, a cyano group, a carbocyclic aromatic group which may have a substituent or a heterocyclic aromatic group which may have a substituent. General formula (2)

[Chemical formula 22] General formula (3)

[Chemical formula 23] General formula (4)

[Chemical formula 24] General formula (5)

[Chemical 25] General formula (6)

[Chemical formula 26] General formula (7)

[Chemical 27] General formula (8)

[Chemical 28] In the formula, X _{1 to} X ₅ represent residues necessary for forming a polycyclic aromatic ring or a heterocyclic ring by condensing with a benzene ring, and Z _{1 to} Z ₃
Represents an oxygen atom or a sulfur atom, R _{1 to} R ₁₀ represent a hydrogen atom, an alkyl group which may have a substituent, a carbocyclic aromatic group or a heterocyclic aromatic group, and R ₁ and R ₂ , R ₃ and R ₄ , R ₇ and R ₈ may combine with each other to form a ring with a nitrogen atom, and R ₉ and R ₁₀ may combine with each other to form a ring with a carbon atom. , M is 1 or 2
Represents an integer of 0, p represents an integer of 0, 1 or 2,
W in the general formula (5) represents a divalent aromatic hydrocarbon group which may have a substituent or a heterocyclic group containing a nitrogen atom in the ring.

Specifically, Y ₁ to Y ₅₄ and B ₁ and B ₂
In the above, examples of the alkyl 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 Examples thereof include groups such as pyridyl, thionyl, thiazolyl, carbazoyl, benzimidazolyl and benzothiazolyl.Substituents include alkyl groups such as methyl, ethyl and propyl, alkoxy groups such as methoxy and ethoxy, fluorine atom, chlorine atom, bromine atom and iodine. a halogen atom and the like, such as atoms, the X ₁ to X _5, polycyclic aromatic ring or a naphthalene ring as a heterocyclic ring, anthracene ring, carbazole ring, benzimidazole carbazole ring, etc. dibenzofuran ring, and, R ₁ to R in _10, the alkyl group methyl, ethyl Include groups such as propyl, Carbocyclic aromatic groups phenyl, naphthyl, anthryl, benzyl, include groups such as phenethyl, a heterocyclic aromatic group pyridyl, thionyl, thiazolyl,
Examples thereof include groups such as carbazoyl, benzimidazolyl, and benzothiazolyl, and examples of the ring formed with a nitrogen atom include groups such as pyrrole, pyrroline, pyridine, indole, imidazole, pyrazol, pyrazoline, oxazine, and phenoxazine. Examples of the ring formed with a carbon atom include fluorene, anthraquinone, xanthone,
1-indanone and the like, and as the substituents in these groups and rings, an alkyl group such as methyl, ethyl and propyl, a fluorine atom, a chlorine atom, a bromine atom,
Examples include halogen atoms such as iodine atom, acyl groups such as acetyl and benzoyl, alkylamino groups such as benzyl group, dimethylamino, diethylamino, phenylcarbamoyl group, nitro group, cyano group, and haloalkyl groups such as trifluoromethyl. In W, a divalent aromatic hydrocarbon group which may have a substituent or a divalent heterocyclic group containing a nitrogen atom in the ring is o-phenylene, o-naphthylene, perinaphthylene, 1,2. -Anthrylene, 3,4-pyrazoldiyl, 2,3-pyridinediyl, 4,5-pyridinediyl, 6,7-indazo-
Examples thereof include divalent groups such as rudiyl and 6,7-quinolinediyl. Substituents include halogen atoms such as fluorine, chlorine, iodine and bromine, alkyl groups such as methyl, ethyl and propyl, and alkoxy such as methoxy and ethoxy. Base,
Examples thereof include alkylamino groups such as dimethylamino and diethylamino, phenylcarbamoyl groups, nitro groups, cyano groups, and haloalkyl groups such as trifluoromethyl.

Further, the present invention comprises an electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has at least two layers of a charge generating layer containing a disazo pigment represented by the general formula (1) and a charge transporting layer. ..

The general formulas (2), (3), (6) to
In (8), when the pigment is a coupler residue in which X _{1 to} X ₅ are combined with a benzene ring to form a benzcarbazole ring, the pigment has a semiconductor having an absorption region extending to the near infrared region. It is also suitable as a charge generating material for a laser.

The present invention also comprises an electrophotographic apparatus provided with the electrophotographic photosensitive member of the present invention.

Further, the present invention comprises an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention and a facsimile having a receiving means for receiving image information from a remote terminal.

Next, typical examples of the disazo pigment represented by the general formula (1) of the present invention are listed in Tables 1 to 22, but the disazo pigment used in the present invention is not limited thereto. The exemplified pigment has a specific structure by describing only the changed portion in the basic type.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

[Table 12]

[Table 13]

[Table 14]

[Table 15]

[Table 16] 1212

[Table 17]

[Table 18]

[Table 19]

[Table 20]

[Table 21]

[Table 22]

The disazo pigment represented by the general formula (1) is prepared by tetrazotizing a corresponding diamine by a conventional method and coupling it with a coupler in an aqueous system in the presence of an alkali, or by adding a tetrazonium salt to a fluoroborate salt or a zinc chloride double salt. Etc., and then easily synthesized by coupling with a coupler in the presence of a base such as soda acetate, triethylamine, N-methylmorpholine in an organic solvent such as N, N-dimethylformamide or dimethylsulfoxide. it can.

In the case of synthesizing a disazo pigment in which A ₁ and A ₂ in the general formula (1) are different coupler residues, one coupler-1 is first added to 1 mol of the above tetrazonium salt.
Moles, then the other coupler-1
Synthesized by coupling moles, or protected one amino group of the diamine with an acetyl group, etc.,
After diazotizing this and coupling one coupler, the protecting group is hydrolyzed with hydrochloric acid or the like, diazotized again, and then the other coupler is coupled to synthesize.

Synthetic Example (Synthesis of Pigment Example 1) 300 ml beaker with 150 ml of water,
20 ml of concentrated hydrochloric acid (0.023 mol)

[Chemical 29] And 9.2 g (0.032 mol) of the above were cooled to 0 ° C.
A solution prepared by dissolving 4.6 g (0.067 mol) of sodium nitrite in 10 ml of water was added dropwise over 10 minutes while maintaining the liquid temperature at 5 ° C. After stirring for 15 minutes, carbon filtration was carried out, 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 to precipitate the borofluoride salt. It was filtered, washed with cold water, then with acetonitrile, and dried under reduced pressure at room temperature. Yield 1
1.9 g, 77% yield

Next, add 500 ml of DMF to a 1 liter beaker,

[Chemical 30] Was dissolved in 12.9 g (0.042 mol) and the liquid temperature was cooled to 5 ° C., and then 9.7 g (0.02
0 mol), then triethylamine 5.1 g
(0.050 mol) was added dropwise over 5 minutes. After stirring for 2 hours, the precipitated pigment was collected by filtration, washed with DMF four times and water three times, and then freeze-dried. Yield 14.3 g, 82% yield.

The electrophotographic photoreceptor of the present invention has a photosensitive layer containing a disazo 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 disazo 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 function-separated photosensitive layer is particularly preferable.

The charge generation layer can be formed by coating a coating solution prepared by dispersing the above-mentioned disazo pigment with a binder resin in a suitable solvent on a conductive support by a known method. The thickness is, for example, 5 μm or less,
It is desirable to form a thin film layer having a thickness of 0.1 to 1 μm. The binder resin used at this time is selected from a wide range of insulating resins or organic photoconductive polymers,
Polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulosic resin, acrylic resin, polyurethane which may have a substituent are preferable, and as the substituent, alkyl such as methyl, ethyl, propyl and the like. Group, halogen atom such as fluorine atom, 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, trifluoromethyl, etc. Groups such as haloalkyl groups. The amount of the binder resin used is 80 in terms of the content rate in the charge generation layer.
It is not more than 40% by weight, preferably not more than 40% by weight. Further, the solvent used is preferably selected from those which dissolve the above-mentioned resin but do not dissolve the charge transport layer or 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, Examples thereof include aromatics such as xylene and chlorobenzene, alcohols such as methanol, ethanol and 2-propanol, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride and trichloroethylene.

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 substance in a solvent together with a suitable binder resin, if necessary, and applying it, and the film thickness thereof 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. Examples of the hole-transporting substance include polycyclic aromatic compounds such as pyrene and anthracene, carbazole-based, indole-based, imidazole-based compounds,
Oxazol-based, thiazole-based, oxadiazol-based,
Heterocyclic compounds such as pyrazol-based, pyrazoline-based, thiadiazol-based, triazol-based compounds, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, N, N-diphenylhydrazino-3-methylidene-
Hydrazone compounds such as 9-ethylcarbazole, α
-Phenyl-4'-N, N-diphenylaminostilbene, styryl-based compounds such as 5- [4- (di-p-tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene, benzidine-based compounds, triary- Rumethane-based compounds, triphenylamine, or polymers having groups consisting of these compounds in the main chain or side chains
(For example, poly-N-vinylcarbazol, polyvinyl anthracene, etc.) can be mentioned. 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 can be used alone or in combination of two or more. When the charge transport material has no film forming property, a suitable binder can be used. Specifically, acrylic resin, polyarylate, polyester, polycarbonate, polystyrene,
Examples thereof include insulating resins such as acrylonitrile-styrene copolymer, polyacrylamide, polyamide, and chlorinated rubber, and organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene.

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, plastics (eg polyethylene,
Polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) or conductive particles (for example, carbon black, silver particles, etc.) coated on a plastic or metal substrate with a suitable binder resin, or conductive particles or plastic or paper. It is possible to use a support or the like impregnated in.

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, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide and 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 disazo pigment and a charge-transporting substance 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 photoreceptor of this example can be formed by applying and drying a liquid in which the above-mentioned disazo pigment and the charge transfer complex are dispersed in a suitable resin solution. In any of the electrophotographic photoreceptors, the crystal form of the disazo pigment represented by the general formula (1) may be amorphous or crystalline, and if necessary, the disazo pigment represented by the general formula (1) may be used. It is also possible to use two or more kinds of pigments in combination, or to use a known charge generating substance in combination.

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

Next, an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member of the present invention will be described. Figure 1
The general construction of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention is shown in FIG. In the figure, reference numeral 1 denotes a drum type photosensitive member as an image bearing member, which is rotationally driven around a shaft 1a in a direction of an arrow at a predetermined peripheral speed. In the course of its rotation, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging means 2, and then at the exposure section 3 an optical image exposure L (slit exposure Laser
Beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then toner-developed by the developing means 4, and the toner-developed image is rotated by the transfer means 5 from a paper feed unit (not shown) between the photosensitive body 1 and the transfer means 5. And is sequentially transferred onto the surface of the transfer material P that is fed in synchronization with the above. The transfer material P that has received the image transfer is separated from the surface of the photoconductor and is introduced into the image fixing means 8 where it is subjected to image fixing and printed out as a copy (copy). The surface of the photoreceptor 1 after the image transfer is transferred by the cleaning means 6 to the toner after transfer.
Is removed to obtain a clean surface, and the pre-exposure means 7 removes the charge to repeatedly use it for image formation. Photoconductor 1
A corona charging device is generally widely used as the uniform charging means 2. Also, as the transfer device 5, corona transfer means is generally widely used. As an electrophotographic apparatus, a plurality of constituent elements such as the photoconductor, the developing unit, and the cleaning unit described above are integrally combined as an apparatus unit, and the unit is detachably attached to the apparatus main body. It may be configured. For example, the photosensitive member 1 and the cleaning means 6 may be integrated into one device unit, and the device body may be detachably configured by using guide means such as a rail. At this time, the above-mentioned apparatus unit may be provided with a charging unit and / or a developing unit. In addition, the light image exposure L is applied to an electrophotographic apparatus such as a copying machine or a printer.
When used as a light source, the reflected light or transmitted light from the original is used, or the original is read and converted into a signal, and the laser beam is scanned, the light emitting diode array is driven, or the liquid crystal shutter is used according to this signal. It is performed by driving the array. Also, a facsimile printer
In this case, the optical image exposure L becomes an exposure for printing the reception data.

FIG. 2 is a block diagram showing an example of this case. The controller 10 controls the image reading unit 9 and the printer 18. The entire controller 10 is C
It is controlled by the PU 16. The read data from the image reading unit is transmitted to the partner station through the transmission circuit 12. The data received from the partner station is sent to the printer 18 through the receiving circuit 11. Predetermined image data is stored in the image memory. The printer controller 17 controls the printer 18. 13 is a telephone. Line 14
The image (image information from the remote terminal connected through the line) received from the demodulator is demodulated by the receiving circuit 11, and then the CPU 16 performs signal processing of the image information and sequentially stores it in the image memory 15. .. When at least one page of image is stored in the memory 15, the image of that page is stored. The CPU 16 reads out 1-page image information from the memory 15 and sends the 1-page image information signalized to the printer controller 17. Upon receiving the image information of one page from the CPU 16, the printer controller 17 controls the printer 18 to record the image information of the page. The CPU 16 is a printer
While recording by 18, the next page is being received.
The image is received and recorded as described above.

[0025]

【Example】

Examples 1-20 5 g of methoxymethylated nylon (number average molecular weight 32,000) and 10 g of alcohol-soluble copolymerized nylon (number average molecular weight 29,000) were dissolved in 95 g of methanol on an aluminum support. Apply the solution with a Mayer bar and the film thickness after drying is 1
An undercoat layer of μm was formed.

Next, 5 g of Pigment Example 1 was added to cyclohexanone 9
To a solution obtained by dissolving 2 g of polyvinylbenzal (benzalization degree of 75% or more) in 5 g, the mixture was dispersed in a sand mill for 20 hours. This dispersion was applied on the previously formed undercoat layer with a Mayer bar so that the film thickness after drying was 0.2 μm, and dried to form a charge generation layer.

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

[Chemical 31] 5 g of polymethylmethacrylate (number average molecular weight 100,000)
Was dissolved in 40 g of chlorobenzene, and this was applied onto the charge generation layer so that the film thickness after drying was 20 μm.
Was coated and dried to form a charge transport layer, whereby the electrophotographic photosensitive member of Example 1 was prepared.

Using other pigments in place of Pigment Example 1, electrophotographic photoreceptors corresponding to Examples 2 to 20 were prepared in exactly the same manner.

The produced electrophotographic photosensitive member is manufactured by Kawaguchi Electric Co., Ltd.
Manufactured by Electrostatic Copy Paper Testing Device Model SP-428, which was negatively charged by corona discharge of -5 KV and kept in a dark place for 1 second, and then exposed with a halogen lamp at an illuminance of 10 lux to evaluate charging characteristics. .. As the charging characteristics, the surface potential (V ₀ ) and the exposure amount (E1 / 2) required for the surface potential after being left in the dark to be attenuated by 1/2 were measured. The results are shown in Table 23.
Shown in.

[Table 23]

Comparative Examples 1 and 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the pigment example 2 used in Example 1 was replaced with the following comparative pigments 1 and 2, and the charging characteristics were similarly set. evaluated. The results are shown in Table 24. Comparative pigment 1

[Chemical 32] Comparative pigment 2

[Chemical 33]

[Table 24] From these results, it can be seen that the electrophotographic photosensitive member of the present invention has sufficient charging ability and excellent sensitivity.

Examples 21 to 30 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 discharge exposure optical system and a cleaner. It was attached to the cylinder of the electrophotographic copying machine. The initial dark portion potential V _D and the light portion potential _VL are set near -700 V and -200 V, respectively,
Amount of fluctuation in dark area potential after repeated use for 5,000 times (Δ
V _D ) and the amount of change in the bright part potential (ΔV _L ) were measured. The electrophotographic photosensitive members prepared in Examples 2, 3, 4, 5, 6, 7, 8, 9 and 10 were evaluated in the same manner. The results are shown in Table 25. In addition, the negative symbol in the variation amount of the potential represents a decrease in the absolute value of the potential, and the positive symbol represents an increase in the absolute value of the potential.

[Table 25]

Comparative Examples 3 and 4 With respect to the electrophotographic photosensitive members prepared in Comparative Examples 1 and 2,
By the same method as in Example 21, the potential fluctuation during repeated use was measured. The results are shown. Comparative Example 3 ΔV _D : -40V, ΔV _L : + 80V Comparative Example 4 ΔV _D : -45V, ΔV _L : + 90V From the above results, it can be seen that the electrophotographic photosensitive member of the present invention has little potential fluctuation during repeated use. ..

Example 31 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 Pigment Example 2 was added to a solution prepared by dissolving 1.5 g of butyral resin (butyralization degree: 63 mol%) in 95 g of cyclohexanone, and the dispersion prepared in the same manner as in Example 1 was applied and dried. As a result, a charge generation layer having a thickness of 0.2 μm was formed.

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

[Chemical 34] A solution prepared by dissolving 6.5 g of polycarbonate (number average molecular weight of 55,000) in 40 g of tetrahydrofuran was applied on the charge generation layer and dried to form a charge transport layer having a thickness of 19 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 21. The results are shown. _{V 0: -700V, E1 / 2} : 1.20 lux-seconds _{ΔV D: -5V, ΔV L:} + 5V

Example 32 An undercoating layer of polyvinyl alcohol having a thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. Onto this, 5 g of Pigment Example 2 was added to a solution of 2 g of poly-p-fluorovinylbenzal (benzalization degree of 75% or more) dissolved in 95 g of tetrahydrofuran, and a dispersion prepared in the same manner as in Example 1 was added. Apply and dry
A charge generation layer having a thickness of 0.2 μm was formed.

Next, 5 g of a triarylamine compound having the following structural formula was added.

[Chemical 35] A solution prepared by dissolving 5 g of polycarbonate (number average molecular weight of 55,000) in 40 g of chlorobenzene was applied onto the charge generation layer and dried to form a charge transport layer having a thickness of 19 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 21. The results are shown. _{V 0: -710V, E1 / 2} : 1.70 lux-seconds _{ΔV D: 0V, ΔV L:} + 5V

Example 33 An electrophotographic photosensitive member was prepared by coating the charge generating layer and the intermediate charge transport layer of the electrophotographic photosensitive member prepared in Example 2 in the reverse order, and the charging characteristics were the same as in Example 1. Was evaluated. However, the charging was positive. The results are shown. V ₀ : +700 V, E1 / 2: 1.55 lux ・ sec

Example 34 On the charge generation layer prepared in Example 2, 4.5 g of 2,4,7-trinitro-9-fluorenone and poly-4,4'-dioxydiphenyl-2,2-propanecarbone were added. A solution prepared by dissolving 5 g of benzene (number average molecular weight of 300,000) in 50 g of NN-dimethylformamide was applied with a Mayer bar to form a charge transport layer having a thickness of 18 μm after drying. The charging characteristics of the produced electrophotographic photosensitive member were evaluated in the same manner as in Example 1. However, the charging was positive. V ₀ : + 690V, E1 / 2: 2.95 lux ・ sec

Example 35 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
5g of the same charge transport material and polycarbonate 5 used in
A solution prepared by dissolving 40 g of tetrahydrofuran in 40 g of tetrahydrofuran was added, and the mixture was stirred for 1 hour. The coating solution thus prepared was coated on an aluminum support with a Mayer bar and dried to give a film thickness of 20.
A photosensitive layer of μm was formed. The charging characteristics of the electrophotographic photosensitive member thus prepared were evaluated in the same manner as in Example 1. The charging was positive. V ₀ : + 680V, E1 / 2: 5.00 lux ・ sec

[0040]

INDUSTRIAL APPLICABILITY In the electrophotographic photoreceptor of the present invention, by using a disazo pigment having a specific structure in the photosensitive layer, either one or both of the generation efficiency of charge carriers and the injection efficiency inside the photosensitive layer is improved. In addition, a remarkable effect that excellent characteristics such as sensitivity and potential stability during repeated use can be obtained, and the same remarkable effect can be obtained in an electrophotographic apparatus and a facsimile equipped with the electrophotographic photosensitive member.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a general transfer type electrophotographic apparatus.

FIG. 2 is a block diagram of a facsimile using the electrophotographic apparatus as a printer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Drum type photoconductor as an image carrier (electrophotographic photoconductor of the present invention) 2 Corona charging device 3 Exposure section 4 Developing means 5 Transfer means 6 Cleaning means 7 Pre-exposure means 8 Image fixing means L Optical image exposure P Transfer material having received image transfer 9 Image reading unit 10 Controller 11 Reception circuit 12 Transmission circuit 13 Telephone 14 Line 15 Image memory 16 CPU 17 Printer controller 18 Printer-

Claims (5)

[Claims] 1. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer containing a disazo pigment represented by the following general formula (1). In the general formula _{(1) A 1 -N = N} -D-N = N-A 2 formula, D is represents any one of structures represented by the following general formula (1-1) ~ (1-7), A 1 And A ₂ represent any of the coupler residues represented by the following general formulas (2) to (8), provided that _one of A ₁ and A ₂ is the coupler residue represented by the general formula (2). General formula (1-1): General formula (1-2): General formula (1-3): General formula (1-4): General formula (1-5) General formula (1-6) General formula (1-7): In the formula, Y _{1 to} Y ₅₄ represent a hydrogen atom, a cyano group, a halogen atom, an alkyl group which may have a substituent, a carbocyclic aromatic group or a heterocyclic aromatic group, and B ₁ and B ₂ Represents a hydrogen atom, a cyano group, a carbocyclic aromatic group which may have a substituent or a heterocyclic aromatic group. General formula (2) General formula (3) General formula (4) General formula (5) General formula (6) General formula (7) General formula (8) In the formula, X _{1 to} X ₅ represent residues necessary for forming a polycyclic aromatic ring or a heterocyclic ring by condensing with a benzene ring, and Z _{1 to} Z ₃
Represents an oxygen atom or a sulfur atom, R _{1 to} R ₁₀ represent a hydrogen atom, an alkyl group which may have a substituent, a carbocyclic aromatic group or a heterocyclic aromatic group, and R ₁ and R ₂ , R ₃ and R ₄ , R ₇ and R ₈ may combine with each other to form a ring with a nitrogen atom, and R ₉ and R ₁₀ may combine with each other to form a ring with a carbon atom. , M is 1 or 2
Represents an integer of 0, p represents an integer of 0, 1 or 2,
W in the general formula (5) represents a divalent aromatic hydrocarbon group which may have a substituent or a heterocyclic group containing a nitrogen atom in the ring. 2. The electrophotographic photosensitive member according to claim 1, wherein the A ₁ and A ₂ are coupler residues represented by the general formula (2). 3. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has at least two layers of a charge generating layer containing a disazo pigment represented by the general formula (1) and a charge transporting layer. 4. An electrophotographic apparatus provided with the electrophotographic photosensitive member according to claim 1. 5. A facsimile having an electrophotographic apparatus equipped with the electrophotographic photosensitive member according to claim 1 and means for receiving image information from a remote terminal. [0001]