JPS62157042A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To reduce a production cost of forming an electrostatic charge generating layer, and to avert the use of org. amines by providing with a photosensitive layer contg. a specific disazo compd. as an effective component on an electroconductive substrate body. CONSTITUTION:The photosensitive layer contg. the disazo compd. shown by the formula as an effective component is provided with on the electroconductive substrate body as the electrostatic charge generating material. 9.5g of 8.6% sodium acetate solution is drop-wisely added to a solution dissolved 1.86g (5.2m mole) 2-hydroxy-3-(4-N-phenylaminophenyl)carbamoyl-naphthalene and 1.02g (2.5m mole) stilbene-4-,4'-bistetrafluoroborate to 200ml N,N-dimethylformimide (DMF), and after dropping, the obtd. solution is stirred for 3hr at a room temp. followed by filtering a precipitate and is washed with N,N-dimethylformamide (DMF) at t times followed by washing with water at 2 times and then is dried with heat under a reduced pressure to form the disazo compd. shown by the formula.

Description

[Detailed Description of the Invention] The present invention relates to a photoreceptor for electrophotography, and more specifically,
A layer containing a disazo pigment as a substance that generates charge carriers when irradiated with light (hereinafter referred to as "charge-generating substance").
A substance (hereinafter referred to as "charge generation layer") that receives and transports charge carriers generated by the charge generation layer (hereinafter referred to as "charge generation layer")
The present invention relates to a laminated electrophotographic photoreceptor comprising a layer containing a charge transport material (hereinafter referred to as a charge transport layer).

■Inorganic photoconductors for electrophotography include those using selenium and its alloys, or photoconductors with dye-sensitized zinc oxide dispersed in a binder resin, and organic photoconductors. Among them, 2゜4.7-dolini-1-rho-9-fluorenone (hereinafter referred to as r'1' NF J) and poly-
A typical example is one using an N-vinylcarbazole complex.

However, while these photoreceptors have many advantages, they also have various disadvantages.

For example, the currently widely used selenium photoreceptor has difficult manufacturing conditions and high manufacturing costs, is difficult to process into a belt due to its lack of flexibility, and is sensitive to heat and mechanical shock. Therefore, care must be taken when handling. Zinc oxide photoreceptors are low in cost because they can be manufactured by coating a support using inexpensive zinc oxide.

Generally low sensitivity, surface smoothness, hardness.

It has mechanical drawbacks such as tensile strength and abrasion resistance, and there are many problems with durability as photoreceptors for plain paper copying machines that are usually used repeatedly. Also.

A photoreceptor using a charge transfer complex of TNF and PVK has low sensitivity and is unsuitable as a photoreceptor for high-speed copying machines.

In recent years, extensive research has been carried out to eliminate the drawbacks of these photoreceptors, and in particular, various organic photoreceptors have been proposed. Among them, a laminated photoreceptor in which a thin film of an organic pigment is formed on a conductive support (charge generation layer), and a layer mainly composed of a charge transport substance (charge transport layer) is formed on top of this, is a layered photoreceptor that is different from conventional organic pigments. Compared to photoconductors, photoconductors are attracting attention as photoconductors for plain paper copying machines because of their high sensitivity and stable charging properties, and some of them are in practical use.

Conventionally, this type of laminated photoreceptor uses (I) a thin layer of a perylene derivative vacuum-deposited as a charge generation layer and an oxadiazole derivative as a charge transport layer (U).
(See S P 3871882) (2) A thin layer formed by coating an organic amine solution of chlordian blue as the charge generation layer and a hydrazone compound as the charge transport layer (Japanese Patent Publication No. 55-4238
(see Publication No. 0) are known.

However, it is true that conventional laminated photoreceptors of this type have many advantages, but also have various drawbacks. That is, it has the following drawbacks.

The photoreceptor using the perylene derivative and oxadiazole derivative shown in (I) has a charge generation layer formed by vacuum deposition, which increases the manufacturing cost.

The photoreceptor using chlordiane blue and a hydrazone compound shown in (2) uses an organic amine (which is generally difficult to handle) as a coating solvent for forming a charge generation layer.
For example, it is necessary to use ethylenediamine), which has many disadvantages in producing photoreceptors.

Purpose: The purpose of the present invention is to provide a photoreceptor that overcomes the above-mentioned conventional drawbacks, and provides a photoreceptor using a novel disazo compound obtained by reacting a novel coupler with a known tetrazonium salt. The purpose is to

Structure The electrophotographic photoreceptor of the present invention has a charge generating substance of general formula (I) or R1R on a conductive support.

[In the formula, -water:- is -a-(Cl(=C1l)n-6-
(In the formula, R and R2 represent hydrogen, a halogen atom, an alkyl group, a nitro group, or an alkoxy group, and n is 0°1.
an integer of 2 or 3) or -Ar, -CH=C
H-At2-C1 (=CH-Ar, - (in the formula, Ar and Ar2 represent substituted or unsubstituted carbocyclic aromatic residues or heterocyclic aromatic residues), Z: ° is benzene A photosensitive layer containing a disazo compound represented by the following atomic group necessary to form a ring, a naphthalene ring, or a carbazole ring as an active ingredient is provided.

It is used in the present invention as described above. The structural formula of a specific example of a disazo pigment is as follows.

(Hereinafter in the margin) Exemplary Compounds (Hereinafter in the margin) By using the disazo compound of the present invention as described above as a charge generating substance, a highly sensitive electrophotographic photoreceptor can be easily produced.

In order to produce the disazo compound of the general formula (I) used in the present invention, the coupling component of the general formula (III), '. same)
The compound represented by the general formula (II
).

'N2-4. "X"'7 Nx" 2 Ae(II
) (wherein A represents an anionic functional group, and J: and about -10
An alkaline aqueous solution such as an aqueous solution of sodium acetate may be added dropwise at a temperature of .degree. C. to 20.degree. The reaction is completed in 5 to 30 minutes to obtain the desired disazo compound of the present invention.

The amount of the coupling component of the general formula (III) to be used is 2 to 1 mole of the tetrazonium salt of the general formula (II).
~5 mol is appropriate.

A production example of the disazo pigment of compound N008 is shown below, but other disazo pigments can also be easily produced according to this production example, except for changing the components used, such as the coupler and the tetrazonium salt.

Production example (Production of disazo compound N008) 2-hydroxy-3-(4-N-phenylaminophenyl)carbamoylnaphthalene 1.86g (5,2ma+ole)
and 1.02 g (2,5++n++ole) of stilbene-4,4'-bistetrafluoroborate were dissolved in 200 m Q of N,N-dimethylformamide (DMF), and 9.5 g of 8.6% sodium acetate solution was added dropwise thereto. did.

After the dropwise addition, after stirring at room temperature for 3 hours, the precipitate was filtered, and N
, washed 5 times with N-dimethylformamide (DMF),
Then, it was washed twice with water and dried by heating under reduced pressure.

The infrared absorption spectrum (KBr tablet method) of the product thus obtained is shown in FIG.

Infrared absorption spectrum (KBr tablet method): 1670
An absorption band based on the carbamoylcarbonyl group (C=O) was observed at cm-''.

Yield 2.03g (yield 86.4%) Decomposition point 3
32°C Elemental analysis value (%) Actual value (calculated value) C: 76.
66 (76,57)H: 4.52 (4,
72) N: 11.75 (I1,91) In the electrophotographic photoreceptor of the present invention, a disazo pigment is used as a charge generating substance in the photosensitive layer.

A typical structure of this photoreceptor is shown in FIGS. 2 and 3.

The photoreceptor shown in FIG. 2 has a laminated photosensitive layer 19 on a conductive support 11, consisting of a charge generation layer 15 mainly composed of a disazo pigment 13 and a charge transport layer 17 mainly composed of a charge transport substance.
It has been established.

In the photoreceptor shown in FIG. 2, the imagewise exposed light passes through the charge transport layer and reaches the charge generation layer 15, where the disazo pigment 13 generates a charge, while the charge transport layer 17 The mechanism is such that the disazo pigment 13 generates the charge necessary for light attenuation, and the charge transport layer 17 transports the charge.

The photoreceptor shown in FIG. 3 has a photosensitive layer 19' mainly composed of a disazo pigment 13, a charge transporting substance, and an insulating binder on a conductive support 11.

Again, the disazo pigment 13 is a charge generating substance.

As for other photoreceptors, it is also possible to reverse the charge generation layer and the charge transport layer as shown in FIG.

The thickness of the photosensitive layer is as shown in FIG. 2, and the thickness of the charge generation layer 15 is preferably 0.01 to 5μ, more preferably 0.05μ.
~2μ. If the thickness is less than 0.01 μm, charge generation will not be sufficient, and if it is more than 5 μm, the residual potential will be too high for practical use.

The thickness of the charge transport layer 17 is preferably 3 to 50 microns, more preferably 5 to 20 microns. If the thickness is less than 3 μm, the amount of charge will be insufficient, and if it is more than 50 g, the residual potential will be too high to be practical.

The charge generation layer 15 is mainly composed of a disazo pigment represented by the above general formula, and may further contain a binder, a plasticizer, and the like. Further, the proportion of the disazo pigment in the charge generation layer is preferably 30% by weight or more, more preferably 50% by weight or more.

The charge transport layer 17 is mainly composed of a charge transport substance and a binder, and may further contain a plasticizer. The proportion of charge transport material in the charge transport layer is from 10 to 95% by weight, preferably from 30 to 90% by weight. When the proportion of the charge transport substance is less than 10% by weight, almost no charge is transported, and when it is more than 95% by weight, the mechanical strength of the photoreceptor film is so poor that it cannot be put to practical use.

In the case of the photoreceptor shown in FIG. 3, the thickness of the photoreceptor layer 19'' is preferably 3 to 50μ, more preferably 5 to 20μ.Also, the proportion of the disazo pigment in the photoreceptor 19 is preferably 50% by weight or less, more preferably 20% by weight
or less, and the proportion of the charge transport substance is preferably 10
~95% by weight, more preferably 30-90% by weight.

The gist of the present invention is to use a specific disazo pigment represented by the general formula (I) as a charge generating substance in an electrophotographic photoreceptor, and a conductive support,
Any conventionally known components such as charge transport materials can be used, and these will be specifically explained below.

The conductive support used in the photoreceptor of the present invention includes a metal plate made of aluminum, copper, zinc, etc., a plastic sheet made of polyester, or a plastic film on which a conductive material such as aluminum, Sn○2, etc. is vapor-deposited;
Alternatively, conductive treated paper or the like may be used.

Binders include polyamide and polyurethane.

Examples include condensation resins such as polyester, epoxy resin, polyketone, and polycarbonate, and vinyl polymers such as polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, and polyacrylamide, but all resins that are insulating and adhesive can be used. Can be used.

Examples of plasticizers include halogenated paraffins, polychlorinated biphenyls, dimethylnaphthalene, and dibutyl phthalate. In addition, silicone oil or the like may be added to improve the surface properties of the photoreceptor.

Charge transporting substances include hole transporting substances and electron transporting substances.Hole transporting substances include, for example, the following general formulas (I) to
Examples include compounds shown in (I1).

[In the formula, R1 represents a methyl group, an ethyl group, a 2-hydroxyethyl group, or a 2-chloroethyl group, and R2 represents a methyl group or an ethyl group.

It represents a benzyl group or a phenyl group, and R3 represents hydrogen, chlorine, bromine, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. ]] Ar-CH=NN- ◎ [In the formula, Ar represents a naphthalene ring, an anthracene ring, a styryl group, a substituent thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents an alkyl group or a benzyl group. ] (Rz)n [In the formula, R1 represents an alkyl group, benzyl group, phenyl group, or naphthyl group, and R2 represents hydrogen, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or a dialkylamino group. , represents a dialkylamino group or a diarylamino group, n represents an integer of 1 to 4, and when n is 2 or more, R2 may be the same or different. R3 represents hydrogen or a methoxy group. [In the formula, R1 represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group, or a heterocyclic group, and R2
H, each of which may be the same or different, represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group, a substituted or unsubstituted aralkyl group,
Further, R2 and R1 may be bonded to each other to form a nitrogen-containing heterocycle. R4 may be the same or different and represents hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a halogen. ] (R) [In the formula, R represents hydrogen or a halogen atom, and Ar
represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group or carbazolyl group. ] [In the formula, R4 is hydrogen, halogen, cyano group, carbon number 1-
4 represents an alkoxy group or an alkyl group having 1 to 4 carbon atoms, Ar represents R2\R3, R2 represents an alkyl group having 1 to 4 carbon atoms,
R3 is hydrogen, halogen, alkyl group having 1 to 4 carbon atoms,
Represents an alkoxy group or dialkylamino group having 1 to 4 carbon atoms, where n is 1 or 2, and when it is 2, R
1 may be the same or different, R4 and R5 are hydrogen,
It represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted benzyl group. ] R-HC=HCCH=CH-R [wherein R is a carbazolyl group, pyridyl group, chenyl group, indolyl group, furyl group, or a substituted or unsubstituted phenyl group, styryl group, naphthyl group or anthryl group, respectively. These substituents include a dialkylamino group, an alkyl group, an alkoxy group, a carboxy group or an ester thereof, a halogen atom, a cyano group, an aralkylamino group, an N-alkyl-N aralkylamino group, an amino group, a nitro group, and an acetylamino group. Represents a group selected from the group consisting of groups. [In the formula, R1 represents a lower alkyl group or a benzyl group,
R2 is a hydrogen atom, a lower alkyl group, a lower alkoxy group,
represents a halogen atom, a nitro group, an amino group, or an amino group substituted with a lower alkyl group or a benzyl group,
n represents an integer of 1 or 2. [In the formula, R1 represents a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom, R2 and R1 represent an alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group, and R4 is hydrogen represents an atom or a substituted or unsubstituted phenyl group, and
Ar represents a phenyl group or a naphthyl group. ] (Left below) C=C-(CH=CHkanA [wherein, n is an integer of 0 or 1, R1 represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted phenyl group,
A represents a 9-anthryl group or a substituted or unsubstituted N-alkylcarbazolyl group, where R2 is a hydrogen atom,
represents an alkyl group, an alkoxy group, a halogen atom or an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, R3 and R4 may form a ring; 1m is O, l, is an integer of 2 or 3, and when m is 2 or more, R2 may be the same or different. [In the formula, R1, R, and R3 represent hydrogen, a lower alkyl group, a lower alkoxy group, a dialkylamino group, or a halogen atom, and n represents 0 or 1. ] Examples of the compound represented by the general formula (I) include 9-ethylcarbazole-3-aldehyde, 1-methyl-1-phenylhydrazone, 9-ethylcarbazol-3-aldehyde 1-benzyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde, These include ethylcarbazole-3-aldehyde 1,1-diphenylhydrazone.

The compound represented by general formula (2) includes, for example, 4-
Diethylaminostyrene-β-aldehyde 1-methyl-
1-phenylhydrazone, 4-methoxynaphthalene-1
-Aldehyde 1-benzyl-1-phenylhydrazone and the like.

Examples of the compound represented by the general formula (3) include 4-methoxybenzaldehyde 1-methyl-1-phenylhydrazone, 2,4-dimethoxybenzaldehyde 1-benzyl-1-phenylhydrazone, and 4-diethylaminobenzaldehyde 1,1-diphenyl Hydrazone, 4-
Examples include methoxybenzaldehyde 1-benzyl-1-(4-methoxy)phenylhydrazone, 4-diphenylaminobenzaldehyde 1-benzyl-1-phenylhydrazone, and 4-dibenzylaminobenzaldehyde-1,1-diphenylhydrazone.

The compound represented by general formula (4) includes, for example, 1,
1-bis(4-dibenzylaminophenyl)propane,
Tris(4-diethylaminophenyl)methane, 1,1
-bis(4-dibenzylaminophenyl)propane, 2
．． 2'dimethyl-4,4'-bis(diethylamino)-
Examples include triphenylmethane.

The compound represented by general formula (5) includes, for example, 9-
(4-diethylaminostyryl)anthracene, 9-bromo-10-(4-diethylaminostyryl)anthracene, and the like.

The compound represented by general formula (6) includes, for example, 9-
(4-dimethylaminobenzylidene)fluorene, 3-
(9-fluorenylidene)-9-ethylcarbazole and the like.

The compound represented by general formula (7) includes, for example, 1,2
-bis(4-diethylaminostyryl)benzene, 1,
2-bis(2,4-dimethoxystyryl)benzene.

The compound represented by general formula (8) includes, for example, 3-
Styryl-9-ethylcarbazole, 3-(4-methoxystyryl)-9-ethylcarbazole Compounds represented by the general formula (9) include, for example, 4-
Diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1- (4
-diphenylaminostyryl) naphthalene, 1- (4
-diethylaminostyryl) naphthylene, etc.

The compound represented by the general formula (I0) includes, for example, 4'
-diphenylamino-α-phenylstilbene, 4′
-methylphenylamino-α-phenylstilbene and the like.

The compound represented by general formula (I1) includes, for example, 1-
Phenyl-3- (4-diferaminostyr+)-
5-<4-diethylaminophenyl)pyrazoline, 1-
Phenyl-3-(4-dimethylaminostyryl)-5
-(4-dimethylaminophenyl)pyrazoline and the like.

Examples of other hole transport substances include 2.

5-bis(4-diethylaminophenyl)-1.

3,4-oxadiazole, 2,5-bis[4- (4
-diethylaminostyryl)phenyl]-1.3.4-
Oxadiazole, 2-(9-ethylcarbazolyl-3)
-)-5- (4-diethylaminophenyl)-1,3
, 4-oxadiazole, 2-vinyl-4-(2-chlorophenyl)-5-(4
-diethylaminophenyl)oxazole, 2- (4
There are low molecular weight compounds such as oxazole compounds such as -diethylaminophenyl)-4-phenyloxazole. Further, polymeric compounds such as poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, pyrene formaldehyde resin, and ethylcarbazole formaldehyde resin can also be used.

Examples of the electron transport substance include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinone dimethane, 2,4,7-dolinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone,
2,4゜5.7-Titranitroxanthone, 2,4.8
-trinitrothioxanthone, 2,6.8-trinitro-4H-indeno(I,2-b)thiophen-4-one, 1,3.7-trinitrodibenzothiophene-5,5
- Dioxide, etc.

These charge transport substances may be used alone or in combination of two or more.

In any of the photoreceptors obtained as described above, an adhesive layer or a barrier layer may be provided between the photoreceptors on the conductive support, if necessary.

Suitable materials for these layers include polyamide, nitrocellulose, aluminum oxide, and the like, and the film thickness is preferably 1 μm or less.

To make the photoreceptor of Figure 2, a disazo pigment on a conductive support was prepared using
96,049, or by dispersing fine particles of a disazo pigment in a suitable solvent in which a binder is dissolved, if necessary, and dispersing this on a conductive support. After coating and drying, if necessary, the surface is finished by a method such as puff polishing as shown in JP-A No. 51-90827, or after adjusting the film thickness, the charge transporting substance and the bond are applied. It is obtained by coating and drying a solution containing the agent.

The photoreceptor shown in FIG. 3 can be prepared by dispersing a fine powder of a disazo pigment in a solution containing a charge transporting substance and a binder, and coating the dispersion on a conductive support and drying it.

In either case, the disazo pigment used in the present invention is used after being ground to a particle size of 5 μm or less, preferably 2 μm or less, using a ball mill or the like. The coating method is carried out by conventional means such as doctor blade, dipping, wire bar, etc.

To perform copying using the photoreceptor of the present invention, the surface of the photoreceptor layer is charged and exposed, and then developed, and if necessary,
This is achieved by transferring to paper or the like.

EXAMPLES Next, the present invention will be specifically explained using Examples, but the embodiments of the present invention are not limited thereby.

Example 1 76 parts by weight of disazo pigment N008, 1260 parts by weight of a tetrahydrofuran solution (solid content concentration 2%) of polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.), and 3700 parts by weight of tetrahydrofuran were pulverized and mixed in a ball mill. The resulting dispersion was applied onto the aluminum surface of an aluminum-deposited polyester paste (conductive support) using a doctor blade, and air-dried to form a charge generation layer with a thickness of about 1 μm.

On this charge generation layer, 2 parts by weight of 9-nityl rubazol-3-aldehyde 1-methyl-1-phenylhydrazone, 2 parts by weight of polycarbonate resin (Panlite-1300 manufactured by Ontaisha Co., Ltd.) and 16 parts by weight of tetrahydrofuran were added as a charge transport substance. A solution in which parts by weight were mixed and dissolved was applied using a doctor blade, and dried at 80°C for 2 minutes and then at 105°C for 5 minutes to form a charge transport layer with a thickness of about 20 μm, resulting in the lamination shown in Figure 2. A mold photoreceptor N001 was prepared.

Examples 2 to 7 Photoreceptors Nos. 2 to 7 were produced in the same manner as in Example 1, except that disazo pigments shown in Table 1 below were used instead of disazo pigment N088 used in Example 1.

Examples 8 to 17 Example 1 except that 1-phenyl-3-(4-diethylaminostyryl)-5-(4-diethylaminophenyl)pyrazoline was used as the charge transport substance and the disazo pigment shown in Table 2 below was used. Photoconductor N008-1 in the same manner as
7 was created.

Examples 18 to 26 Photoreceptor No. 1 was prepared in the same manner as in Example 1 except that 9-(4-diethylaminostyryl)anthracene was used as the charge transport substance and the disazo pigment shown in Table 3 below was used.
8 to 26 were created.

Examples 27 to 34 Photoreceptors were prepared in the same manner as in Example 1, except that α-phenyl-4'-(N,N-diphenylamino)stilbene was used as the charge transport substance and the disazo pigment shown in Table 4 below was used. No. 27-34 were created.

These photoreceptors Nos. 1 to 34 were negatively charged by -6KV corona discharge for 20 seconds using an electrostatic copying paper tester (F41 manufactured by Kawaguchi Yoki Seisakusho, Model 5P428). The surface potential Vpo (V) was measured by leaving it in a dark place for seconds, and then irradiating the surface with light using a tungsten lamp at an illuminance of 4.5 lux until the surface potential was 1/2 of Vpo. Find the time (seconds) until the
was calculated. The results are shown in Tables 1 to 4.

(The following is a margin) Table-1 (The following is a margin) Table-2 Table-3 (The following is a margin) Table-4 (The following is a margin) Furthermore, the photoconductor of the present invention is used in a copier P-500 model manufactured by Ricoh Co., Ltd. The photoreceptor was attached to the photoreceptor and the image output was repeated to and ooo times, but as a result, clear images were obtained without any change in any of the photoreceptors due to the repetition of the copying process. From this, it can be understood that the photoreceptor of the present invention is also excellent in durability.

Effects As is clear from the above explanation and examples, the electrophotographic photoreceptor using the novel disazo compound of the present invention as a charge generating substance is easy to manufacture, has high sensitivity,
The characteristics are stable even after repeated use of the photoreceptor.
Has excellent properties.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum (KBrBr method) of disazo compound N018 of the present invention. FIGS. 2 and 3 are enlarged sectional views showing examples of the structure of the photoreceptor of the present invention. DESCRIPTION OF SYMBOLS 11... Conductive support, 13... Disazo compound 15... Charge generation layer, 17... Charge transport layer 19,
19″...photosensitive layer

Claims (1)

[Claims] 1. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) [In the formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼▼
There are chemical formulas, tables, etc. ▼ (In the formula, R_1 and R_2 are hydrogen, halogen atoms, alkyl groups,
nitro group or alkoxy group, n is an integer of 0, 1, 2 or 3) or -Ar_1-CH=CH-Ar_2-CH=CH-Ar
_1- (wherein Ar_1 and Ar_2 represent a substituted or unsubstituted carbocyclic aromatic residue or heterocyclic aromatic residue)
▲There are mathematical formulas, chemical formulas, tables, etc. ▼ indicates the atomic group necessary to form a benzene ring, naphthalene ring, or carbazole ring] It is characterized by containing a disazo compound represented by the following as an active ingredient. A photoreceptor for electrophotography.