JPS60220350A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body superior in film-forming physical property, and electrophotographic characteristics, such as electrostatic charge retentivity, sensitivity, and resistance to residual potential, and reduced in fatigue deterioration by using an azo compd. represented by the formula as a photoconductor for constituting the photosensitive layer of the sensitive body. CONSTITUTION:The azo compd. represented by the formula is synthesized by tetraazotizing diamine represented by the general formula: H2N-A-NH2 by the ordinary method, and coupling a corresponding coupler in the presence of alkali, or once isolating a tetrazonium salt, and then, coupling it in a proper solvent. The electrophotographic sensitive body has a photosensitive layer contg. at least one kind of this azo compd.. When it absorbs light, it generates a charge carrier with extremely high efficiency. The generated carrier can be moved through the medium of the azo compd., and it can be moved through the medium of a charge transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more particularly to a novel electrophotographic photoreceptor having a photosensitive layer containing an azo compound.

More specifically, the present invention relates to a highly durable electrophotographic photoreceptor that has high sensitivity and is suitable for repeated use.

Conventionally, electrophotographic photoreceptors having a photosensitive layer made of an inorganic photoconductor such as selenium, zinc oxide, or cadmium sulfide have been widely known.

However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc., and in particular, selenium and cadmium sulfide are toxic, so there are restrictions in production and handling.

On the other hand, electrophotographic photoreceptors having a photosensitive layer containing an organic photoconductive compound as a main component are relatively easy to manufacture, inexpensive, and easy to handle, and are generally more expensive than selenium photoreceptors. It has many advantages such as low thermal stability, and has attracted a lot of attention in recent years.

Poly-N-vinylcarbazole is well known as such an organic photoconductive compound, and 2.4.
Electrophotographic photoreceptors having a photosensitive layer containing as a main component a charge transfer complex formed from a Lewis acid such as 7-dolinitrile and 9-fluorenone are not always satisfactory in terms of sensitivity and durability.

On the other hand, in laminated type or dispersed type functionally separated photoreceptors in which the carrier generation function and the carrier transport function are assigned to separate substances, each material has a wide selection range (
, electrophotographic properties such as charging properties, sensitivity, and durability,
This method has the advantage that an electrophotographic photoreceptor having arbitrary characteristics can be produced relatively easily.

Conventionally, various carrier-generating substances or carrier-transferring substances have been proposed.

For example, an electrophotographic photoreceptor has been put into practical use which has a photosensitive layer in which a carrier generation layer made of amorphous selenium and a carrier transfer layer mainly made of triboly-N-vinylcarbazole are combined.

However, a carrier generation layer made of amorphous selenium has a drawback of poor durability.

In addition, various proposals have been made to use organic dyes and pigments as carrier-generating substances. -424
Publication No. 1, Japanese Unexamined Patent Publication No. 1983-46558, Special Publication No. 1983
-11945 publication etc. are already publicly known.

However, these azo compounds have poor characteristics such as sensitivity, residual potential, and stability when used repeatedly.
The reality is that nothing that fully satisfies the wide range of requirements of the electrophotographic process has yet been obtained, as it is not always possible to satisfy the requirements, and the selection range of carrier transfer substances is also limited.

An object of the present invention is to provide an electrophotographic photoreceptor containing an azo compound that is stable to heat and light and has excellent carrier generation ability.

The purpose of the pond of the present invention is to have high sensitivity, low residual potential,
Another object of the present invention is to provide an electrophotographic photoreceptor with excellent durability whose properties do not change even after repeated use.

A further object of the present invention is to provide an electrophotographic photoreceptor containing an azo compound that can effectively act as a carrier generating substance even in combination with a wide variety of carrier transfer substances.

As a result of intensive research to achieve the above object, the present inventors have discovered that an azo compound represented by the following general formula (1) can act as an active ingredient of a photoreceptor, and have completed the present invention. .

General formula (1) (In the formula, A is a divalent residue bonded to the N atom forming an azo at the C atom, and zl and z2 are substituted or unsubstituted carbocyclic aromatic rings or , a group of atoms necessary to form a substituted or unsubstituted heterocyclic aromatic ring or an unsaturated monocyclic hydrocarbon ring.) That is, in the present invention, the atomic group represented by the general formula (1) By using an azo compound as a photoconductive substance constituting the photosensitive layer of an electrophotographic material, and by utilizing only the excellent carrier generation ability of the azo compound of the present invention, this can be used to improve the generation and movement of carriers respectively. Do this with a separate substance.

By using it as a carrier generating material in so-called function-separated electrophotographic photoreceptors, it has excellent skin absorption properties, maintains electrophotographic properties such as charge retention, sensitivity, and residual potential, and does not deteriorate due to fatigue even when used repeatedly. It is possible to produce an electrophotographic photoreceptor that is small in amount and exhibits stable characteristics without any change in the above-mentioned characteristics even when exposed to heat or light.

Specific examples of the azo compound useful in the present invention represented by the general formula (1) include those having the following structural formula, but the azo compound of the present invention is not limited thereto.

Exemplary Compounds The azo compound represented by the general formula [11] is represented by the general formula H2
A diamine represented by N-A-NH2 (wherein A has the same meaning as above) is tetrazotized by a conventional method, and then the corresponding coupler is subjected to force-knobling in the presence of an alkali, or a tetrazonium salt of the diamine described above is prepared. Once isolated in the form of borofluoride salt or zinc chloride double salt, etc., it is coupled with force-soplar in the presence of an alkali in a suitable solvent such as N, N-dimethylformamide, dimethyl sulfoxide, etc. It can be easily synthesized by

Next, a method for synthesizing representative examples of the azo compound used in the present invention will be shown.

Synthesis example (exemplified compound Nα12) 3.3'-dichlorobenzine dihydrochloride 13.04y (4
Disperse 5.52 P (80 mmole) in a mixture of 20 ml of concentrated hydrochloric acid and 4 C) sl of water.
) of sodium nitrite dissolved in water was cooled with water to prepare 2-hydroxy-N-(2-benzothiazolyl)-11H benzocarno(sol-3-
Carbozamide 12.3y (30mmole), triethylamine 6.5y (65mmol) as organic amine
e) was dissolved in L)MF 1000- and cooled to 0-5°C. Next, the above diazonium salt solution was dropped into the coupler solution, and the resulting blue-purple paste liquid was
The mixture was kept at 10° C. and stirred for an additional 3 hours. The formed precipitate was filtered through a stone, thoroughly washed with acetone, then with water, and finally with chloroform to obtain a deep blue powder of 8.3F after drying. The melting point was 350°C or higher. Other azo compounds of the present invention can also be obtained according to the above synthesis example.

The electrophotographic photoreceptor of the present invention has a photosensitive layer containing one or more azo compounds represented by the general formula (11). Photosensitive layers in various forms are well known, but the electrophotographic photoreceptor of the present invention The photosensitive layer of the photoreceptor may be in any of these types, but is usually of the type shown below.

■ A photosensitive layer made of an azo compound ■ A photosensitive layer in which an azo compound is dispersed in a binder ■ A photosensitive layer in which an azo compound is dispersed in a well-known charge transfer substance The azo compound represented by the above general formula generates charges and carriers with extremely high efficiency when it absorbs light. Although the generated carriers can be transferred using an azo compound as a medium, it is preferable to transfer the generated carriers using a known charge transfer substance as a medium. From this point of view, photosensitive layers having the forms (1) and (2) are particularly preferred.

Charge transfer substances are generally classified into two types: electron transfer substances and hole transfer substances, and both can be used in the photosensitive layer of the photoreceptor of the present invention, and mixtures or mixtures of substances having the same function can be used. , mixtures of different functionalities can also be used. Examples of substances that transfer electrons include electron-withdrawing compounds having electron-withdrawing groups such as nitro, cy, ano, and ester groups.
．． 4.7-Dolinitrofluorenone, 2.4.5.7-
Nitrated fluorenone such as titranitrophylolenon, or tetracyano, quinodimethane, tetracyanoethylene, 2,4.5.7-titranitroxanthone,
Compounds such as 2.4.8-trinidrothioxanthone,
Examples include polymerized electron-absorbing compounds.

Furthermore, examples of electron-donating organic photoconductive compounds that can be used as hole transport media include the following.

hydrazones 02H.

2H5 (9) 02) 2H5 Pyrazolines NN Diarylalkane (1) n-C3H? (2) -C3Hy (3) -CaHt n -C3H7 (5) -C3H7 Ha 2H11 (7) -C3H7 CH3 (αCH2)2N-C>CH2<nN (CH2u)2
Alkylenediamines (1) 2benzylanilines (1) Triphenylamines (11(2) HsCHs Triarylalkanes H3 (4) CII3 H II H CH3CH3 Oxadiazoles-N Anthracenes Oxazoles, Thiazoles ( 1) (2) α>CH=CHuN (C2Hs)2 etc.Other polymer compounds include poly-N-vinylcarbazole, halogenated polyN
-Vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, polyglycidylcarbazole, polyvinylacenaphthylene, ethylcarnoxole -Formaldehyde carrier transfer materials are not limited to those listed herein, and when used, the carrier One type of transfer substance or a mixture of two or more types can be used.

The electrophotographic photoreceptor of the present invention can be manufactured according to a conventional method.

For example, in an electrophotographic photoreceptor having a photosensitive layer of the type (2) above, a coating solution obtained by dissolving or dispersing the azo compound represented by the general formula (1) in a suitable medium is coated on a conductive support. It can be manufactured by coating and drying to form a photosensitive layer having a thickness of usually several μm to several + μm.

Media for preparing the coating solution include basic solvents that dissolve bisazo compounds such as butylamine and ethylenediamine; ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as methyl ethyl ketone and cyclohexanone; and aromatic substances such as toluene and xylene. Group hydrocarbon: N
．． Aprotic polar solvents such as N-dimethylformamide, acetonitrile, N-methylpyrrolidone, and dimethylsulfoxide; Alcohols such as methanol, ethanol, and isoprononol; and esters such as ethyl acetate, methyl acetate, and methyl cellosolve acetate; dichloroethane, and chloroform. Examples include media for dispersing azo compounds such as chlorinated hydrocarbons.

When using a medium for dispersing an azo compound, it is necessary to micronize the azo compound to a particle size of 5 μm or less, preferably 3 μm or less, and optimally 1 μm or less.

Further, as the conductive support on which the photosensitive layer is formed, any of those employed in well-known electrophotographic photoreceptors can be used.

Specifically, for example, a metal drum made of aluminum, copper, etc.
Examples include sheets, laminates and vapor deposits of these metal foils.

Further examples include plastic films, plastic drums, paper, etc. which are coated with a conductive substance such as metal powder, carbon black, copper iodide, or polymer electrolyte together with a suitable binder to conductivity treatment.

Other examples include plastic sheets and drums that contain conductive substances such as metal powder, carbon black, and carbon fibers and are made conductive.

If a binder is dissolved in the coating liquid used to form the photosensitive layer of the type (2) above, an electrophotographic photoreceptor having the photosensitive layer of the type (2) above can be produced.

In this case, the medium of the coating liquid is preferably one that dissolves the binder.

Examples of binders include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, acrylic esters, and methacrylic esters, phenoxy resins, polysulfones, ester resins, polycarbonates, polyesters,
Examples include various polymers such as cellulose ester, cellulose ether, urethane resin, epoxy resin, and acrylic polyol resin.

The amount of binder used is usually 0, 1 to 1, based on the azo compound.
The range is 5 times the weight.

In addition, in forming this type of photosensitive layer,
The bisazo compound is mixed into a binder with a fine grain size, e.g.
It is preferable that the particles be present in the form of fine particles of 1 pm or less.

Similarly, by dissolving a charge transfer medium in the coating liquid used to form the photosensitive layer of the type (2) above, an electrophotographic photoreceptor having the photosensitive layer of the type (2) above can be manufactured. As the charge transfer medium, any of those exemplified above can be used.

Apart from charge transport media which can themselves be used as binders, such as polyvinylcarbazole and polyglycidylcarbazole, it is preferred to use other binders.

As the binder, any of those exemplified above can be used.

In this case, the amount of the binder used is usually 5 to 10 times the weight of the azo compound, and the amount of the charge transfer medium used is usually 0.2 to 1.5 times the weight of the binder.
Preferably it is in the range of 0.3 to 1.2 times by weight. In the case of a charge transport medium which itself can be used as a binder, it is usually used in amounts of 5 to 10 times the weight of the azo compound.

In this type of photosensitive layer, similarly to the photosensitive layer of type (1) above, it is preferable that the bisazo compound is present in the charge transport medium and the binder in the form of fine particles.

If a coating solution obtained by dissolving a charge transfer medium in a suitable medium is applied onto the photosensitive layer of the types ① to ① above and dried to form a charge transfer layer, the electron Photographic photoreceptors can be manufactured.

In this case, H? The photosensitive layer of type I. ■ to ■ plays the role of a charge generation layer. The charge transfer layer does not necessarily need to be provided on top of the charge generation layer, but may be provided between the charge generation layer and the conductive support. good. However, the former is preferable in terms of durability.

The charge transfer layer is formed in the same manner as the photosensitive layer described in (2) above. That is, the coating liquid for forming the photosensitive layer described in (1) above, except that the azo compound is removed, may be used as the coating liquid.

Typically the charge generating layer is 5 to 50 micrometers thick.

Of course, the photosensitive layer of the electrophotographic photoreceptor of the present invention may contain a known sensitizer.

Suitable sensitizers include Lewis acids and dyes that form charge transfer complexes with organic photoconductive materials.

Examples of Lewis acids include quinones such as chloranil, 2,3-dichloro-1,4-naphthoquinone, 2-methylanthraquinone, 1-nitroanthraquinone, 1-chloro-5-nitroanthraquinone, 2-chloroanthraquinone, and phenanthrenequinone. aldehydes such as 4-nitrobenzaldehyde, 9-benzoylanthracene, indanedione, 3,5-dinitrobenzophenone,
3. Ketones such as 3'55'-tetranitrobenzophenone, acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride, cyanos such as tetracyanoethyln, terephthalmalononitrile, and 4-nitrobenzalmalonnitrile Compound: 3-benzalphthalide, 3-(--cyanoP
-nitrobenzal)phthalide, 3-(α-cyano-P-
Examples include electron-withdrawing compounds such as nitrobenzal) phthalides.

Examples of dyes include triphenylmethane dyes such as methyl violet, brilliant green, and crystal violet, thiazine dyes such as methylene blue, quinone dyes such as quinizarin, cyanine dyes, pyrylium salts, thiapyrylium salts, and benzopyrylium salts.

In addition to these, it may contain inorganic photoconductive fine particles such as selenium and selenium-arsenic alloys, copper, and organic photoconductive pigments such as phthalocyanine pigments and perylene pigments. Furthermore, the photosensitive layer of the electrophotographic photoreceptor of the present invention may contain a well-known plasticizer in order to improve film formability, flexibility, and mechanical strength.

Plasticizers include notaric acid ester, phosphoric acid ester,
Examples include epoxy compounds, chlorinated paraffins, chlorinated fatty acid esters, and aromatic compounds such as methylnaphthalene.

Moreover, it goes without saying that it may have an adhesive layer, an intermediate layer, and a transparent insulating layer, if necessary.

The photoreceptor using the azo compound of the present invention has high sensitivity and good color sensitivity, and when used repeatedly, there is little variation in sensitivity and chargeability, little optical fatigue, and extremely high durability. It is.

Further, the photoreceptor of the present invention can be widely used in electrophotographic applications such as photoreceptors for printers using lasers, cathode ray tubes (CRTs), and light emitting diodes (LEDs) as light sources in addition to electrophotographic copying machines.

EXAMPLES Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless the gist thereof is understood.

Example 1 Polyester film laminated with aluminum foil (Alpet 85 manufactured by Daido Kako, aluminum film thickness 10 μm)
) on a conductive support consisting of vinyl chloride: vinyl acetate: maleic anhydride copolymer (S-LEC MF- manufactured by Tanezu Kagaku Co., Ltd.)
IQ) with a thickness of 0.05 μm, and 2y of exemplified compound Nα1 and polyarylate resin (U-100 manufactured by Unitika) 2y were mixed in 100 m of 1,2-dichloroethane.
In addition to 1, an azo compound dispersion obtained by dispersing in a paint conditioner for about 1 hour is applied onto the intermediate layer so that the film thickness after drying is 0.5μ, and is dried to form a carrier generation layer. , further carrier transfer substance N,
A solution of 5 N-dibenzylaminobenzaldehyde-1,1-diphenylhydrazone dissolved in 50 d of 1,2-dichloroethane together with a polyarylate resin 7 y was coated so that the film thickness after drying was 12 μm, and the carrier was transferred. A layer was formed to produce an electrophotographic photoreceptor of the present invention. After storing this photoreceptor at room temperature at 30°C in a dark place for - weeks, it was tested using an electrostatic paper tester rsP-428J (
(newly manufactured by Kawaguchi Electric) and conducted the following characteristic tests.

That is, a voltage of -6 KV is applied to the charger to charge the photosensitive layer by corona discharge for 5 seconds, and the potential Vo (V) at that time is
Next, the exposure jitEi (lu
!・Seconds).

Further, the surface potential after exposure with an exposure amount of 301 ux·sec, that is, the residual potential F, 50 (V) was measured. Similar measurements were repeated 500 times. A tungsten lamp was used as the light source for residual potential static elimination at 3001 ux and 0.
Further irradiation exposure was performed for 3 seconds to completely reduce the residual potential to 0.

The results are shown in Table 1.

Table 1 Examples 2 to 5 Exemplary compounds 5°6 and 1 as carrier generating substances, respectively
2.16. A total of four types of electrophotographic photoreceptors of the present invention were prepared in the same manner as in Example 1, except that the photoreceptors were used, and the same characteristic tests were conducted on each of them.

The results are shown in Table 2.

Table 2 Example 6 A 0.04 μm thick layer of vinyl chloride:vinyl acetate (8'7:13) copolymer (V Y HH manufactured by UCIC) was placed on the outer surface of a 60 mm diameter drum made of aluminum. Form an intermediate layer, add 4 pieces of Exemplified Compound 20 to 400 Ml of 1,2-dichloroethane, and disperse the resulting dispersion for about 3 hours using a paint conditioner. A carrier generation layer was formed by coating and drying so that the particle diameter was 0.5μ. A carrier transfer substance N, N-diallylaminobenzaldehyde-1-phenyl-1-methylhydrazone 10y, which is arranged on the carrier generation layer, is mixed with 12F of polycarbonate resin (Panlite L-1250 manufactured by Ondai) and 100y of 1,2-dichloroethane. ml solution to a film thickness of 15 ml after drying.
A carrier moving layer was formed by coating and drying so as to have a particle diameter of .mu., thereby producing a drum-type electrophotographic photoreceptor according to the present invention.

When this electrophotographic photoreceptor was installed in our modified commercially available cartridge-type electrophotographic copying machine and a copied image was formed, a clear visible image with high contrast and faithful to the original was obtained.

The copying process was repeated 1000 times, and until the end, a visible image equivalent to that of the first copy was obtained.

Example 7 The reflection spectrum of the drum-type electrophotographic photoreceptor obtained in Example 6 was measured using a spectrophotometer equipped with an integrating sphere (UV-365 manufactured by Shimadzu).
), and the graph is shown in FIG. From this graph, the maximum absorption wavelength in the visible region of this photoreceptor is 665
It turned out to be around nm. Further 67 Qnm168
When the spectral sensitivity at 0 nm was measured using a monochrome meter, the energy required to halve the potential was approximately 3.5 erg/cd for both wavelengths, which is a very high photoreceptor, and a light emitting diode (LED) was used as the light source. It was found that the photoreceptor was sufficiently durable for practical use even when using the following methods.

Examples 8 to 12 An intermediate layer with a thickness of 0.05μ made of vinyl chloride: vinyl acetate copolymer (Kanevirac L-CP manufactured by Kaneka Co., Ltd.) was formed on a conductive support made of a polyester film on which aluminum was vapor-deposited, Exemplary compounds 10, 19, 32,
A solution of the azo compounds Nos. 35 and 42 dissolved in n-butylamine was applied onto the intermediate layer to form a carrier generating layer having a thickness of 0.1 μm. Then, 1-diethylaminophenyl-3-phenyl-5 is applied on this carrier generation layer.
- A solution of Styryl Hirasoline 5F and polyester resin (Vylon-200 manufactured by Toyobo Co., Ltd.) 511 dissolved in 40 ml of 1,2-dichloroethane was coated and dried to form a carrier transport layer so that the film thickness after drying was 14゛μ. An electrophotographic photoreceptor of the present invention was prepared. Based on the reflection/absorption curves of these five types of photoreceptors, the maximum absorption wavelength in the visible to near infrared range and the energy required to reduce the potential by half at that wavelength were determined according to Example 7.

The results are shown in Table 3. Incidentally, the initial potential VO of all photoreceptors exceeded 500 (-V).

Table 3 Example 13 Styrene: methyl methacrylate: methacrylic acid copolymer (styrene: methyl methacrylate) = 2:1 weight ratio, acid value 185) and Exemplary Compound 16 were placed on an Al plate with a grained surface. and tonitrofluorenone at a ratio of 1.5:1.
: A solution prepared by blending at a weight ratio of 0.3 and dissolving (resin component, trinitrofluorenone) in dioxane and dispersing (azo compound) was applied and dried to prepare a single layer type photoreceptor with a film thickness of 6 μm.

The photoreceptor of the present invention thus prepared was subjected to an electrophotographic property test using the electrostatic paper tester described above.

Applied voltage +6KV Vo = 420 (+V) E4- = 8.5 (1u
!・Seconds).

In addition, this photoreceptor is visualized with a developer (toner), and then an alkaline processing solution (for example, 3% triethanolamine,
When treated with 10946 ammonium carbonate and 2096 polyethylene glycol with an average molecular weight of 190 to 210, the toner-free areas are easily eluted, and then washed with water containing sodium silicate to easily create a printing original plate. We were able to.

When offset printing was performed using this original plate, it was found that it could withstand printing of about 100,000 sheets.

In addition, in order to obtain a toner visible image (light source: halogen lamp)
The optimum exposure amount was 5 olux·seconds, and the printing original plate was created by direct plate making without using any base material.

[Brief explanation of the drawing]

FIG. 1 is a reflection/absorption curve of the photoreceptor of the present invention in Example 7. Fig. 1 3L-k (φ)

Claims (1)

[Scope of Claims] (1) An electrophotographic photoreceptor comprising a photosensitive layer containing an azo compound represented by the following general formula (1) on a conductive support. (In the formula, A is a divalent residue bonded to the N atom forming an azo with the C atom, and Zl and Z2 are substituted or unsubstituted carbocyclic aromatic rings or substituted or unsubstituted (2) the photosensitive layer contains a carrier substance and a carrier generating substance; The electrophotographic photoreceptor according to claim 1, wherein the carrier generating substance is an azo compound represented by the general formula (1). (3) The electrophotographic photoreceptor according to claim 1, wherein the azo compound represented by the general formula (1) is a compound represented by the following structural formula. (In the formula, door and n are 0 or 1, and zl and Z2 are synonymous with the first term.) (4) The azo compound represented by the general formula (1) is a compound represented by the following structural formula. An electrophotographic photoreceptor according to claim 1. (In the formula, X is hydrogen, methoxy, ethoxy, halogen, methyl, ethyl, nitro, and Zl + 22 has the same meaning as in item 1.) (5) The azo compound represented by the general formula (1) is as follows. The electrophotographic photoreceptor according to claim 1, which is a compound represented by the structural formula. . (In the formula, Y is hydrogen, halogen, or cyano group, and Zl +
22 has the same meaning as the first term. ) (6) The above general formula (1
2. The electrophotographic photoreceptor according to claim 1, wherein the azo compound represented by ) is a compound represented by the following structural formula. (In the formula, 2 is 10-1-S-1-NH-, Z, ,
Z2 has the same meaning as the first term. ) (7) The general formula (1
2. The electrophotographic photoreceptor according to claim 1, wherein the azo compound represented by ) is a compound represented by the following structural formula. (In the formula, R1 is hydrogen, alkyl, allyl, benzyl which may have a substituent, or phenyl which may have a substituent, and z1z2 has the same meaning as in item 1.) (8) Said The electrophotographic photoreceptor according to claim 1, wherein the azo compound represented by general formula (1) is a compound represented by the following structural formula. (In the formula, z1122 has the same meaning as in paragraph 1.) (9) The electronic device according to claim 1, wherein the azo compound represented by the general formula (1) is a compound represented by the following formula: Photographic photoreceptor. 2 (wherein R2 is hydrogen, alkyl, allyl, propargyl, benzyl 2 which may have a substituent is 10-1-S-1
and Zl and z2 are synonymous with the first term. )(lθ) The electrophotographic photoreceptor according to claim 1, wherein the azo compound represented by the general formula (1) is a compound represented by the following structural formula. (In the formula, R3 is alkyl, allyl, propargyl, methalyl hydrogen, and Zl + 22 has the same meaning as in the first term.) (Kawa) The azo compound represented by the general formula (1) above is a compound represented by the following structural formula. An electrophotographic photoreceptor according to claim 1. (In the formula, R4 and Rs are hydrogen, halogen, alkyl, methoxy, and nitro, and Zl + 22 has the same meaning as in claim 1.)