JPH0427953A - Electrophotographic sensitive body, electrophotographic apparatus using same, and facsimile - Google Patents

Abstract

PURPOSE:To obtain practicable high sensitivity characteristics and stable potential characteristics at the time of repeated uses by forming a photosensitive layer containing a specified azo pigment on a conductive substrate. CONSTITUTION:The photosensitive layer to be formed on the conductive substrate contains the azo pigment represented by formula I in which X is an atomic group necessary to form an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group; Ar1 is an optionally substituted aromatic hydrocarbon group or heterocyclic group optionally combined through a bonding group; Ar2 is an optionally substituted aromatic hydrocarbon group or heterocyclic group; and (n) is 1, 2, or 3. Thus high sensitivity characteristics and superior potential stability characteristics at the time of repeated uses are provided.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to electrophotographic photoreceptors, electrophotographic devices, and facsimile machines, and more specifically, to electrophotographic photoreceptors having a photosensitive layer containing an azo face 14 having a specific structure. The present invention relates to a photoreceptor, an electrophotographic device using the photoreceptor, and a facsimile.

[Prior Art] Conventionally, inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide have been widely used as electrophotographic photoreceptors.

On the other hand, electrophotographic photoreceptors made of organic photoconductive substances include photoconductive polymers typified by poly-N-vinylcarbazole and 2.5-bis(p-diethylaminophenyl).
-Those using low-molecular organic photoconductive substances such as 1,3,4-oxadiazole, and those that combine such organic photoconductive substances with various dyes and pigments are known. ing.

Electrophotographic photoreceptors using organic photoconductive substances have good film-forming properties and can be produced by coating, so they have the advantage of providing extremely highly productive and inexpensive photoreceptors. Also,
It has the advantage of being able to freely control color sensitivity depending on the selection of dyes and door lacquers used, and has been studied extensively to date. In particular, recent developments have led to the development of functionally separated photoreceptors in which a charge generation layer containing an organic photoconductive dye or pigment is laminated with a charge transport layer containing the aforementioned photoconductive polymer or low-molecular organic photoconductive substance. Significant improvements have been made in the sensitivity and durability, which were considered to be disadvantages of conventional organic electrophotographic photoreceptors.

Azo pigments exhibit excellent phototetraelectricity, and compounds with various properties can be easily obtained by combining amine components and coupler components, so many compounds have been proposed to date.

Coupler components used in such azo pigments include, for example, naphthol AS compounds described in JP-A-47-37543, and benzcarbazole-based compounds described in JP-A-53-95033. , naphthalimide compounds described in JP-A-54-79632, and perinone-based compounds described in JP-A-57-176055 are already known.

However, conventional electrophotographic photoreceptors using disazo materials are not necessarily sufficient in terms of sensitivity and potential stability during repeated use, and only a few materials have been put into practical use. .

[Problems to be Solved by the Invention] The objects of the present invention are to provide a new photoconductive material and to provide an electrophotographic photoreceptor having practical high sensitivity characteristics and stable potential characteristics during repeated use. An object of the present invention is to provide an electrophotographic apparatus and a facsimile using the electrophotographic photoreceptor.

[Means for Solving the Problems, Effects] The present invention comprises an electrophotographic photoreceptor characterized by having a photosensitive layer containing an azo pigment represented by the following general formula (1) on a conductive support.

In the general formula, represents an aromatic hydrocarbon group or heterocyclic group which may have a substituent which may be bonded, and A r x represents an aromatic hydrocarbon group or heterocyclic group which may have a substituent; , n is 1~
Represents an integer of 3.

As a specific example of Ar+ and Ar in the binding allowance (1),
benzene, naphthalene, fluorene, phenanthrene,
Aromatic hydrocarbon rings such as anthracene and pyrene, heterocycles such as furan, thiophene, pyridine indole, benzothiazole, carbazole acridone, dibenzothiophene, benzoxazole, oxadiazole, thiazole, and the above aromatic hydrocarbon rings or Heterocycles bonded directly or with aromatic or non-aromatic groups, such as biphenyl, binaphthyl, diphenylamine, triphenylamine, N-methyldiphenylamine,
Fluorenone, phenanthrequinone, anthraquinone,
Benzanthrone, terphenyl, diphenyloxadiazole, stilbene, distyrylbenzene, phenylbenzoxazole, diphenylmethane, diphenylsulfone, diphenyl ether, benzophenone, tetraphenyl-p-phenylenediaminetetraphenylbenzidine, N-phenyl-2-pyridylamine, N, N-
Examples include groups such as diphenyl-2-pinozylamine.

Substituents that the above aromatic hydrocarbon group or heterocyclic group may have include alkyl groups such as methyl, ethyl, brobyl, butyl, alkoxy groups such as methoxy, ethoxy, and propoxy, fluorine, chlorine, bromine, etc. Examples include a halogen atom, a dialkylamino group such as dimethylaminodiethylamino, a hydroxy group, a nitro group, a cyano group, and a halomethyl group.

Further, the present invention comprises an electrophotographic apparatus equipped with the electrophotographic photoreceptor of the present invention.

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

Representative examples of the azo pigment represented by the formula (1) are listed below, but the azo pigment used in the present invention is not limited to these.

The description method is to show only the changed parts of the basic model.

Exemplary pigment Exemplary pigment (1-2) Exemplary pigment (1-3) Art d -()OCH- Exemplary pigment (1-4) C! Exemplary pigment Exemplary pigment (1-6) r ÷cH=co4 elbow Exemplary pigment Exemplary pigment (1-8) N Exemplary pigment (1-9) C~ Exemplary pigment (1 N Exemplary pigment (1 xHa Exemplary pigment Exemplary pigment (2- Ar+: blasphemy +c = C) I-@- Exemplary pigment (2-2) r -@-c=CH building Exemplary pigment (2-3) Exemplary pigment (2-4) death! Exemplary pigment (2-5) Exemplary pigment (2-6) Basic type 3 Exemplary pigment Art: cormorant I2 Exemplary pigment (3-2) Exemplary pigment (3-3) Exemplary pigment (3-4) Exemplary pigment (3-5) Basic type 4 Exemplary pigment (4-1) Ar Ar 2: (proof○(飄) cormorant I2 :Hydrogen atom Exemplary pigment R: CHs Exemplary pigment diatomic Exemplary pigment (4-4) Ar+: ÷N・N(t :Hydrogen atom Exemplary pigment (4-5) R: I2 Exemplary pigment (4-6) R: Ar Exemplary pigment (4-7) R: hydrogen atom Exemplary pigment (4-8) I2 Exemplary pigment (4-9) hydrogen atom Exemplary pigment N R: -CJs Exemplary pigment engineering) Argument: N sha C = CH sha R: -NO.

n:2 Exemplary Pigment (4-12) R:Br The azo B material represented by the general formula (1) is obtained by diazotizing the corresponding amine by a conventional method and converting it into the following general formula (2) in the presence of an alkali.
) in an aqueous system, or a diazonium salt is coupled with a borofluoride salt or Represents a residue necessary to form a ring, and Arz represents an aromatic hydrocarbon ring group and a heterocyclic group that may have a substituent.) After converting to zinc chloride double salt etc., N,N - It can be easily synthesized by coupling with a coupler in an organic precipitant such as dimethylformamide or dimethyl sulfoxide in the presence of a base such as sodium acetate, triethylamine, or N-methylmorpholine.

[Synthesis example] Synthesis of coupler in exemplified pigment (1) 5.0 g of 2,3-dihydroxynaphthalene (
0,031 mol) and N.

Add 20 mε of N-dimethylformamide (DMF),
After cooling to 5°C, 5.0 g of 2-ethylbenzenediazonium tetrafluoroborate (
0,028 mol) was added and stirred for 1 hour. Thereafter, the precipitated product was collected by filtration and recrystallized from DMF.

Yield 6.34g, Yield 81.5% Synthesis of Exemplary Pigment (1) In a 300mf2 beaker, 150mI2 of water and 20m concentrated hydrochloric acid.
℃ (0.23 mol) and 6.82 g (0,032 mol) of N-methyl divalaminophenylamine were added and cooled to 0 ℃, and 4.6 g (0,067 mol) of sodium nitrite was dissolved in 10 mj2 of water. 1 while keeping the liquid temperature at 5℃.
It was dropped in 0 minutes. After stirring for 15 minutes, carbon filtration was performed, and 10.5 g of sodium borofluoride was added to this solution.
, 096 mol) dissolved in 90+r+J2 of water was soaked under stirring, and the precipitated borofluoride salt was collected by filtration, washed with cold water, washed with acetonitrile, and dried under reduced pressure at room temperature.

Yield: 9.03 g, yield: 68.7% Next, 500 mff of DMF was placed in a II2 beaker, and 11.68 g (0,042 mol) of the coupler synthesized in the above synthesis example was dissolved. After cooling the liquid temperature to 5°C, 8.22 g (0,020 mol) of the borofluoride salt were dissolved, and then 5.1 g (0,050 mol) of triethylamine was dissolved in the solution.
It was dripped in minutes. After stirring for 2 hours, the precipitated pigment was collected by filtration, washed four times with DMF and three times with water, and then freeze-dried.

Yield: 11.64 g, Yield: 69.2% The electrophotographic photoreceptor of the present invention has the general formula (
It has a photosensitive layer containing the azo pigment shown in 1). The form of the photosensitive layer may be any known form, but the photosensitive layer containing the azo pigment represented by the general formula (1) is used as the charge generation layer, and the 1F charge transport layer contains a charge transport substance. Particularly preferred is a functionally separated type photosensitive layer in which the following layers are laminated.

The charge generation layer can be formed by applying a coating solution in which the above-mentioned azo pigment is dispersed together with a binder resin in a suitable solvent onto a conductive support by a known method, and the film thickness thereof is, for example. 5μm or less, preferably 0.
A thin film layer of 1 to 1 μm is desirable.

The binder resin used in this case is selected from a wide range of insulating resins or organic photoconductive polymers, including polyvinyl butyral, polyvinylbenzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulose resin, acrylic resin, polyurethane. etc., and the amount used is 8% in terms of content in the charge generation layer.
It is 0% by weight or less, preferably 40% by weight or less.

The solvent used is preferably selected from those that dissolve the resin described above but do not dissolve the charge transport layer or 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, Examples include aromatics such as chlorobenzene, alcohols such as methanol, ethanol, and 2-propanol, and aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichlorethylene.

The charge transport layer is laminated above or below the charge generation layer, and has the function of receiving charge carriers from the charge generation layer in the presence of an electric field and transporting them.

The charge transport layer is formed by dissolving a charge transport material in a solvent together with an appropriate binder resin as necessary and coating the layer, and the film thickness is generally 5 to 40 um, but 1.
5 to 30 LLm is preferred.

Charge transporting substances include electron transporting substances and hole transporting substances. Examples of electron transporting substances include 2゜4,7-dolinitrofluorenone, 2,4,5゜7-titranitrofluorenone, chloranil, and tetranitrofluorenone. Examples include electron-withdrawing substances such as cyanoquinodimethane, and polymerization of these electron-withdrawing substances.

Hole-transporting substances include polycyclic aromatic compounds such as pyrene and anthracene, carbazole-based, indole-based, imidazole-based, oxazole-based, thiazole-based, oxadiazole-based, pyrazole-based pyrazoline-based, thiadiazole-based, triazole-based compounds, etc. heterocyclic compound, p-
Hydrazone-based compounds such as diethylaminobenzaldehyde-N,N-diphenylhydrazone, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, α-phenyl-4°-N,N-diphenylaminostilbene, 5-[ Mainly containing styryl compounds such as 4-(di-p-tolylamino)benzylidene]-5H-dibenzo[a,d]cycloheptene, benzidine compounds, triarylmethane compounds, triphenylamine, or groups consisting of these compounds. Examples include polymers having it in the chain or side chain (eg, 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 materials can be used alone or in combination of two or more.

When the charge transport material does not have film-forming properties, a suitable binder can be used. Specifically, insulating resins such as acrylic resin, polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, polyamide, and chlorinated rubber, or organic photoconductive resins such as poly-N-vinylcarbazole and polyvinylanthracene. Polymers and the like can be mentioned.

Examples of the conductive support on which the photosensitive layer is formed include aluminum, aluminum alloy, copper, zinc stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum. Plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) and conductive particles (e.g., carbon black,
A support in which a plastic or metal substrate is coated with silver particles, etc.) together with a suitable binder resin, or a support in which plastic or paper is impregnated with conductive particles can be used.

An undercoat layer having barrier and adhesive functions can also 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 6101 copolymerized 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.
m is appropriate.

Another specific example of the present invention is an electrophotographic photoreceptor containing the above-mentioned disazo pigment and charge transport material in the same layer. At this time, poly-N-
Charge transfer complexes consisting of vinyl carbazole and trinitrofluorenone can also be used.

The electrophotographic photoreceptor of this example can be formed by coating and drying a solution in which the azo pigment and charge transfer complex described above are dispersed in a suitable resin solution.

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

The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser beam printers, CRT printers,
It can also be widely used in electrophotographic applications such as LED printers, liquid crystal printers, laser engravings, and facsimile printers.

Next, an electrophotographic apparatus and a facsimile equipped with the electrophotographic photoreceptor of the present invention will be described.

FIG. 1 shows a schematic configuration of a general transfer type electrophotographic apparatus using the drum type photoreceptor of the present invention.

In the figure, reference numeral 1 denotes a drum-type photoreceptor as an image carrier, which is rotated at a predetermined circumferential speed in the direction of the arrow around an axis 1a. During the rotation process, the photoreceptor 1 is uniformly charged with a predetermined positive or negative potential on its circumferential surface by the charging means 2, and then exposed to a light image by an image exposure means (not shown) in the exposure section 3 using slit a light. laser beam scanning exposure, etc.).

As a result, electrostatic latent images corresponding to the exposed images are sequentially formed on the circumferential surface of the photoreceptor.

The electrostatic latent image is then developed with toner by the developing means 4,
The toner developed image is sequentially transferred by the transfer means 5 from a paper binding section (not shown) onto the surface of the transfer material P that is fed between the photoreceptor l and the transfer means 5 in synchronization with the rotation of the photoreceptor 1. To go.

The transfer material P that has undergone the image transfer is separated from the photoreceptor surface and introduced into the image fixing means 8, where the image is fixed and a copy is produced.
will be printed out on the outside of the aircraft.

After the image has been transferred, the surface of the photoreceptor 1 is cleaned by a cleaning means 6 to remove residual toner, and subjected to a charge removal process by a pre-exposure means 7, and is repeatedly used for image formation. As the uniform charging means 2 for the photoreceptor 1, a corona charging device is generally widely used. Further, in the transfer device 5, a corona transfer means is widely used in -JIG.

An electrophotographic apparatus is constructed by combining a plurality of components such as the photoreceptor and developing means cleaning means described above into an apparatus unit, and this unit is configured to be detachable from the apparatus main body. Also good. For example, the photoreceptor 1 and the cleaning means 6 may be integrated into one device unit, and configured to be detachable using a guide means such as a rail of the device body. At this time, the above-mentioned device unit may include a charging means and/or a developing means.

In addition, when an electrophotographic device is used as a copying machine or a printer, light image exposure involves scanning the reflected light or transmitted light from the document, or by reading the document and converting it into a signal. driving the array,
Alternatively, it is performed by driving a liquid crystal shutter array.

Furthermore, when used as a facsimile printer, the optical image exposure is exposure for printing received data.

FIG. 2 is a block diagram showing an example of this case.

A controller 10 controls an image reading section 9 and a printer 18.

The entire controller 10 is controlled by a CPU 16.

The read data from the image reading section is transmitted to the partner station through the transmitting circuit 12. 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. A printer controller 17 controls a printer 18. 13 is a telephone.

The image received from the line 14 (image information from a remote terminal connected via the line) is demodulated by the receiving circuit 11, and then the CPU 6 performs signal processing on the image information and sequentially stores it in the image memory 15. Ru. and at least 1
When the image of the page is stored in the memory 15, the image of the page is stored. The CPU 16 reads out one page of image information from the memory 15 and sends out the one page of image information signaled to the printer controller 17.

When the printer controller 17 receives one page of image information from the CPL 116, it controls the printer 18 to record the image information of that page.

Note that the CPU 16 receives the next page while the printer 18 is recording.

As described above, images are received and recorded.

[Example] Examples 1 to 20 5 g of methoxymethylated nylon (weight average molecular weight: 32,000) and 10 g of alcohol-soluble copolymerized nylon (weight average molecular weight: 29,000) were placed on an aluminum substrate in 95 g of methanol.
A solution dissolved in the above was applied using a Meyer bar to form an undercoat layer having a thickness of 1 μm after drying.

Next, add 5g of exemplified pigment (1-1) to 95% of cyclohexanone.
g of butyral resin (degree of butyralization 63 mol%)
g was added to the dissolved liquid and dispersed in a sand mill for 20 hours. This dispersion was applied onto the previously formed undercoat layer using a Mayer bar so that the film thickness after drying would be 0.2 μm, and dried to form a charge generation layer.

Next, 5 g of a hydrazone compound represented by the structural formula below and 5 g of polymethyl methacrylate (number average molecular weight: 100,000) were dissolved in 40 g of chlorobenzene, and this was placed on the charge generation layer so that the dry film thickness would be 20 μm. The electrophotographic photoreceptor of Example 1 was prepared by coating with a bar and drying to form a charge transport layer.

Electrophotographic photoreceptors corresponding to Examples 2 to 20 were prepared in exactly the same manner using other exemplary pigments in place of exemplary pigment (1-1).

The prepared electrophotographic photoreceptor was negatively charged with a corona discharge of 15 KV using an electrostatic copying paper tester Model 5P-428 manufactured by Kawaguchi Denki ■, held in a dark place for 1 second, and then charged with a halogen lamp. It was exposed to light at an illuminance of 10 lux and the charging characteristics were evaluated.

The charging characteristics include the surface potential (■o) and the amount of exposure required to attenuate the surface potential to 1/2 after being left in the dark (El/2).
was measured. Show the results.

19 (4-11) 710 2, 5
20 (4-12) 710 2.
2 Comparative Examples 1 and 2 Electrophotographic photoreceptors were prepared in exactly the same manner as in Example 1, except that the azo pigment used in Example 1 was replaced with comparative pigments (A) and (B) shown by the following structural formulas. , charging characteristics were similarly evaluated. Show the results.

Comparative pigment (A) comparative pigments (B) (A) (B) 6゜ 7.

This result shows that the electrophotographic photoreceptor of the present invention has sufficient charging ability and excellent sensitivity.

Examples 21 to 23 The electrophotographic photoreceptor prepared in Example 1 was used in an electrophotographic copying machine equipped with a -6.5 KV corona charger, an exposure optical system, a developer, a transfer charger, a static elimination exposure optical system, and a cleaner. Attached to the cylinder.

The initial dark potential ■ゎ and light potential ■ are each -700
V, set at around -200V and used repeatedly 5,000 times.
ΔV, ) was measured.

The electrophotographic photoreceptors prepared in Examples 2 and 3 were also evaluated in the same manner. Show the results.

Note that a negative sign in the potential variation amount represents a decrease in the absolute value of the potential, and a positive sign represents an increase in the absolute value of the potential.

21 -15 +2022
-15 +1523 -20
+20 Comparative Examples 3 and 4 The electrophotographic photoreceptors prepared in Comparative Examples 1 and 2 were used in Example 2.
The amount of potential fluctuation during repeated use was measured using the same method as in 1. Show the results.

3 -30 +754
-40 +60 From the above results, it can be seen that the electrophotographic photoreceptor of the present invention has little potential fluctuation during repeated use.

Example 24 A subbing 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. On top of this, the azo pigment dispersion used in Example 1 was applied with a Mayer bar and dried to a film thickness of 0.2 μm.
A charge generation layer was formed.

Next, a solution prepared by dissolving 5 g of a styryl compound having the following structural formula and 5 g of polycarbonate (number average molecular weight: 55,000) in 40 g of tetrahydrofuran was applied onto the charge generation layer and dried to form a charge transport layer with a thickness of 20 um.

The charging characteristics and durability characteristics of the produced electrophotographic photoreceptor were measured in the same manner as in Examples 1 and 21. Show the results.

■. Knee 690■ El/2: 2.6I2ux-sec △Vo Knee 10V △VL: +20V Example 25 An electrophotographic image in which the charge generation layer and charge transport layer of the electrophotographic photoreceptor prepared in Example 24 were applied in the reverse order. A photoreceptor was prepared, and its charging characteristics were evaluated in the same manner as in Example 1. however,
The charging was positive.

■. : +675V El/2:5.1J2ux-sec Example 26 5 g of 2.4°7-dolinitro-9-fluorene and poly-44'-dioxydiphenyl-2,2 were placed on the charge generation layer prepared in Example 1. -Propane carbonate (molecular weight 3
A solution obtained by dissolving 5 g of 10,000 yen) in 50 g of tetrahydrofuran was coated with a Mayer bar and dried to form a charge transport layer with a thickness of 18 μm.

The charging characteristics of the produced electrophotographic photoreceptor were evaluated in the same manner as in Example 1. However, the charging was positive.

Vo: +695V El/2: 5.8I2ux-sec Example 27 0.5g of exemplified pigment (4-1) was mixed with cyclohexanone 9.
It was dispersed with 5 g in a paint shaker for 5 hours. A solution prepared by dissolving 5 g of the charge transport material used in Example 1 and 5 g of polycarbonate in 40 g of tetrahydrofuran was added thereto, and the mixture was further shaken for 1 hour. The coating solution thus prepared was applied onto an aluminum substrate using a Mayer bar and dried to a film thickness of 20μ.
A photosensitive layer of m was formed.

The charging characteristics of the produced electrophotographic photoreceptor were evaluated in the same manner as in Example 1. The charging was positive.

■. : +700V El/2:4.1I2ux-sec [Effects of the Invention] The electrophotographic photoreceptor of the present invention uses a disazo pigment with a specific structure in the photosensitive layer, thereby improving the generation efficiency or injection of charge carriers inside the photosensitive layer. This has the remarkable effect of improving either or both of the efficiencies and providing excellent characteristics in sensitivity and potential stability during repeated use.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a general transfer type electrophotographic apparatus. Reference numeral 1 denotes a drum-type photoreceptor (electrophotographic photoreceptor of the present invention) as an image carrier, 2 a corona charging device, 3 an exposure section, 4
is a developing means, 5 is a transfer means, 6 is a cleaning means, 7
8 is a pre-exposure means, 8 is an image fixing means, L is a light image exposure, and P is a transfer material subjected to image transfer. FIG. 2 is a block diagram of a facsimile machine using an electrophotographic device as a printer. Reference numeral 9 is an image reading unit, 10 is a controller 11 is a receiving circuit, 12 is a transmitting circuit, 13 is a telephone, 14 is a line, 15
16 is a CPU, 17 is a printer controller, and 18 is a printer.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer containing an azo pigment represented by the following general formula (1) on a conductive support. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) In the formula, X is necessary to form an aromatic hydrocarbon ring or an aromatic heterocycle that may be fused with a benzene ring and may have a substituent. Ar_1 represents an aromatic hydrocarbon group or heterocyclic group which may have a substituent which may be bonded via a bonding group, and Ar_2 represents an aromatic hydrocarbon group which may have a substituent. represents a group hydrocarbon cyclic group or a heterocyclic group, and n is 1 to
Represents an integer of 3. 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer comprises at least two layers: a charge generation layer containing an azo pigment represented by formula (1) and a charge transport layer. 3. An electrophotographic apparatus comprising the electrophotographic photoreceptor according to claim 1. 4. A facsimile machine comprising an electrophotographic apparatus equipped with the electrophotographic photoreceptor according to claim 1 and a receiving means for receiving image information from a remote terminal.