JP3258788B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a single-layer organic electrophotographic photosensitive member useful for an electrophotographic copying machine, a printer, and the like.

[0002]

2. Description of the Related Art Conventionally, as a photoconductive material used for an electrophotographic photoreceptor, inorganic photoconductive materials such as selenium, zinc oxide and cadmium sulfide, organic photoconductive materials such as azo pigments, and amorphous silicon are generally used. Are known. However, inorganic photoconductive materials have problems such as photosensitivity, thermal stability, durability, and toxicity. For example, selenium has a drawback that it is easily crystallized by heat, dirt, and the like, and its characteristics are easily degraded. Compared to the electrophotographic photoreceptor using this inorganic photoconductive material, the organic photoconductive material has advantages such as excellent film formability, easy production, high degree of freedom of design, lower cost and no pollution. Therefore, in recent years, electrophotographic photosensitive members using organic photoconductive materials have been actively developed. Electrophotographic photoreceptors using an organic photoconductive material include a function-separated type photoreceptor in which a charge generation layer and a charge transport layer are laminated, and a single-layer type photoreceptor in which a charge generation material is dispersed in a resin binder. Among them, a laminated photoreceptor has been put to practical use because of its higher sensitivity.

For example, Japanese Patent Publication No. 55-42380 discloses a laminated photoreceptor in which chlordiane blue and a hydrazone compound are combined, and a charge generating substance used in the laminated photoreceptor is disclosed in JP-A-53-133445. ,
JP-A-54-21728, JP-A-54-22283
No. 4 and the like, and examples of charge transport materials include JP-A-58-198043 and JP-A-58-19935.
No. 2, for example. However, in the case of a laminated photoreceptor, it is generally necessary to reduce the thickness of the charge generation layer to 0.1 to 1.0 μm in order to increase the sensitivity, and the state of the surface of the conductive substrate and the time of coating It is easily affected by atmosphere and environment, and greatly affects yield, manufacturing cost, and the like.

The charge transport material contained in the charge transport layer is required to have a high charge mobility in order to increase the sensitivity. Most of the charge transport materials having a high charge mobility have a hole transporting property. Therefore, the photoconductors put into practical use are limited to those of negative charge type. Most of such negatively charged photoreceptors utilize a negative corona discharge during use, so that a large amount of ozone is generated, which is not only harmful to the human body but also reacts with the photoreceptor. The life of the photoconductor itself is also shortened. To prevent this, special systems have been proposed and put into practical use, such as a charging system that does not easily generate ozone, a system that decomposes generated ozone, and a system that exhausts ozone in the device. There are disadvantages such as doing.

On the other hand, a single-layer type photoreceptor is generally known as a positively charged type photoreceptor.
No. 0496, polyvinyl carbazole and 2,
A photoreceptor containing 4,7-trinitro-9-fluorenone, a photoreceptor sensitized with polyvinyl carbazole described in JP-B-48-25658 with a pyrylium salt dye, or a photoreceptor containing a eutectic complex as a main component JP-A-47-3
No. 0330, a photoreceptor comprising a charge generating substance and a charge transporting substance, from a perylene pigment and a charge transporting substance described in JP-A-63-271461, JP-A-1-118143, and JP-A-3-65761. And a photoreceptor comprising a phthalocyanine compound and a binder resin described in JP-A-3-65961 have been proposed. However, these single-layer type photoreceptors are inadequate particularly in terms of sensitivity, and are inferior to the lamination type photoreceptors.

[0006] In recent years, with the increasing complexity and function of copiers, photoconductors corresponding to copiers having analog and digital functions have been developed. In this case, the characteristics required for the photoconductor are
It is desirable to have high sensitivity in the wavelength of the LD laser light source, that is, in the near-infrared region, and to have high sensitivity in the wavelength of the white light source, that is, in the visible region to support the analog function.

As such a photoreceptor, Japanese Patent Application Laid-Open No.
236047, JP-A-63-243950, JP-A-63-243951, JP-A-1-31
No. 5752 discloses a laminated photoreceptor having a mixture of a pigment having sensitivity in the visible region and a pigment having sensitivity in the near infrared region and having a wide spectral sensitivity from the visible region to the near infrared region. However, in the case of these stacked types, since the charge transporting substance coming in the upper layer absorbs light, there is a disadvantage that the light sensitivity is deteriorated particularly in a short wavelength range, and the range is from the visible range to the near infrared range. It was not always enough to have a wide spectral sensitivity.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and in particular, has a single-layer type which has high sensitivity from the visible region to the near-infrared region and further has excellent charging characteristics. An object of the present invention is to provide an electrophotographic photosensitive member.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a mixture obtained by simultaneously pulverizing and mixing a disazo pigment and a trisazo pigment on a conductive support, a charge transport material, and a binder. The present inventors have found that an electrophotographic photoreceptor provided with a single photoconductive layer containing a coloring resin meets the above-mentioned object, and have completed the present invention.

That is, according to the present invention, in a photoconductor for electrophotography comprising a photoconductive layer formed on a conductive support, the photoconductive layer comprises at least one specific disazo pigment and at least one type of disazo pigment. Comprising a single layer containing a co-ground mixture of the above trisazo pigment, a charge transporting substance and a binder resin.

The photoreceptor for electrophotography according to the present invention comprises, in a single photoconductive layer, a disazo pigment having sensitivity to visible light and a trisazo pigment having sensitivity to so-called near-infrared light having a wavelength of 700 nm or more. And high sensitivity to a wide range of light from visible light to near-infrared light. Although this sensitizing effect will be clarified in the examples described below, by mixing and grinding the disazo pigment and the trisazo pigment simultaneously by applying mechanical energy, the sensitivity is significantly sensitized more than the case of each pigment alone. This is different from the mixing effect of a conventionally proposed combination of pigments.

The optimum mixing ratio of the disazo pigment and the trisazo pigment used in the present invention is determined in consideration of the characteristics (sensitivity, charging characteristics, gas resistance) required of the photoreceptor depending on the type of the pigment to be mixed. Can be selected individually,
Generally, the weight ratio is preferably in the range of 0.01 ≦ disazo pigment / (disazo pigment + trisazo pigment) ≦ 0.99. If it is lower than 0.01, the sensitizing effect of the sensitivity is low, and if it is higher than 0.99, the sensitizing effect and the improvement in gas resistance are low. Further, considering the uniformity of spectral sensitivity from the visible light wavelength region to the near infrared light wavelength region, the range of 0.1 ≦ disazo pigment / (disazo pigment + trisazo pigment) ≦ 0.9 is desirable.

The disazo pigment and the trisazo pigment may be mixed by a method such as ball mill, vibration mill, disk vibration mill, attritor, sand mill, paint shaker, jet mill, ultrasonic dispersion method, etc. Any pulverizing / mixing means for providing mechanical energy such as friction, stretching, impact, and vibration can be used. Further, it is preferable that desired amounts of the disazo pigment and the trisazo pigment are contained in the same container, and the above-mentioned mechanical energy is simultaneously applied and mixed and pulverized in the presence of a dispersion solvent to be described later to perform dispersion.

In the electrophotographic photoreceptor of the present invention, as described above, a mixture of a disazo pigment and a trisazo pigment is used as the charge generating material, and in particular, light irradiation in the visible light region (400 to 700 nm). A disazo pigment represented by the following general formula 1 having a high charge generation capability by the following general formula 2 which is particularly sensitive to light having a wavelength of 700 nm or more.
A co-ground mixture with a trisazo pigment represented by

[0015]

Embedded image

Embedded image ｛Wherein Ar ¹ , Ar ² and Ar ^{3 in} the above chemical formulas ¹ and ²
Represents a coupler residue represented by the following general formulas 3 to 10, which may be the same or different. Also, R ¹ and R ²
Represents a hydrogen atom, a halogen atom, a trifluoromethyl group, a nitro group, or a cyano group, and R ³ represents a hydrogen atom,
Chlorine atom, fluorine atom, iodine atom, bromine atom, -NO
₂ or -CN is shown. )

Embedded image [Wherein X ¹ , Y ¹ and Z each represent the following. X ¹ : —OH, —N (R ⁴ ) (R ⁵ ), or —NHSO ₂ —
R ⁶ (however, R ⁴ and R ⁵ represent a hydrogen atom, an acyl group, or a substituted or unsubstituted alkyl group, and R ⁶ represents a substituted or unsubstituted aryl group.) Y ¹ : a hydrogen atom, a halogen atom a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group, a sulfonic group, benzimidazolyl group, a substituted or unsubstituted sulfamoyl group, or ^{-CON (R 7) (Y 2} ).
(However, R ⁷ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, and Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or —N = C (R ⁸ ) (R ⁹ ) << R ⁸
Is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, R
⁹ is a hydrogen atom, an alkyl group or a substituent thereof, or
Represents a phenyl group or a substituent thereof, or represents R ⁸
And R ⁹ may form a ring with the carbon atom to which they are attached. >>. Z: represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof. ]

[0016]

Embedded image [Wherein, R ¹⁰ , R ¹¹ , Y ¹ and n each represent the following. n: an integer of 1 to 4, R ¹⁰ : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, R ¹¹ : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy Group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted alkylmercapto group, halogen atom, substituted or unsubstituted aryl group, substituted or unsubstituted acyl group, cyano group, nitro group, and substituted or unsubstituted Wherein n is an integer of 2 to 4, R ¹¹ may be the same or different. Y ¹ represents the same as in the above formula 3. ]

Embedded image

Embedded image [However, in Formulas 5 and 6, R ¹² represents a substituted or unsubstituted hydrocarbon group. ]

[0017]

Embedded image

Embedded image [However, in Formulas 7 and 8, R ¹³ represents an alkyl group, a carbamoyl group, a carboxy group, or an ester thereof, and Ar ⁴ represents a substituted or unsubstituted aromatic hydrocarbon group. ]

Embedded image

Embedded image [However, in the formulas 9 and 10, X ² represents a divalent group of an aromatic hydrocarbon or a divalent group of a heterocyclic ring. ]｝

Next, specific examples of the couplers of the aforementioned disazo pigments and trisazo pigments used in the electrophotographic photoreceptor of the present invention, namely, Ar ¹ -H, Ar ² -H and Ar
Specific examples of ^3- H are shown in Tables 1 to 16 below.

[0019]

[Table 1- (1)]

[0020]

[Table 1- (2)]

[0021]

[Table 1- (3)]

[0022]

[Table 2- (1)]

[0023]

[Table 2- (2)]

[0024]

[Table 3- (1)]

[0025]

[Table 3- (2)]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

[0029]

[Table 7]

[0030]

[Table 8]

[0031]

[Table 9]

[0032]

[Table 10]

[0033]

[Table 11]

[0034]

[Table 12- (1)]

[0035]

[Table 12- (2)]

[0036]

[Table 12- (3)]

[0037]

[Table 13- (1)]

[0038]

[Table 13- (2)]

[0039]

[Table 13- (3)]

[0040]

[Table 14- (1)]

[0041]

[Table 14- (2)]

[0042]

[Table 15]

[0043]

[Table 16]

Among the azo pigments described above, among the disazo pigments, compounds represented by the following formulas 12 and 13 are particularly preferable. These compounds have high sensitivity in the visible region, and when simultaneously pulverized and mixed in combination with a trisazo pigment, the stability of the pigment dispersion coating solution is good, a good coating film can be formed, and a large sensitization is achieved. The effect can be expected.

[0045]

Embedded image

Embedded image

As the trisazo pigment, a compound represented by the following general formula (11) is preferable.
And Chemical Formula 27 are preferred. This is because the trisazo compound represented by the general formula (11) is particularly useful in the near infrared region (700 n
m or more) is a material having a high charge generation ability by light irradiation,
Simultaneous pulverization and mixing with a disazo pigment makes it possible to prepare a photoreceptor having high photosensitivity over a wide range from the visible region to the near-infrared region. Particularly, trisazo compounds represented by formulas (26) and (27) are particularly preferred. This is because it has a wide photosensitive wavelength range up to around 850 nm, and it becomes possible to prepare a photosensitive member having high sensitivity to LD light (780 to 850 nm) by mixing with a disazo pigment.

[0047]

Embedded image (Wherein, R ^{1 to} R ⁹ are a hydrogen atom, —CH ₃ , —C ₂ H
_5, -C ₃ H _7, a chlorine atom, a fluorine atom, an iodine atom, a bromine _{atom, CH 3 O-, C 2 H} 5 O-, C 3 H 7 O -, - NO 2,
Shown -CN, -CF ₃ or -OH, respectively. )

[0048]

Embedded image

[0049]

Embedded image

As the charge transport material used in the present invention, any known materials can be used. Specific examples thereof include the compounds shown in Table 17 having a basic structure represented by the following general formula (28).
No. 302260).

[0051]

Embedded image

[0052]

[Table 17- (1)]

[0053]

[Table 17- (2)]

[0054]

[Table 17- (3)]

[0055]

[Table 17- (4)]

[0056]

[Table 17- (5)]

[0057]

[Table 17- (6)]

[0058]

[Table 17- (7)]

[0059]

[Table 17- (8)]

[0060]

[Table 17- (9)]

[0061]

[Table 17- (10)]

[0062]

[Table 17- (11)]

[0063]

[Table 17- (12)]

As other charge transporting substances used in the electrophotographic photoreceptor of the present invention, for example, oxazole derivatives, imidazole derivatives, triphenylamine derivatives and the like can be used. Such compounds.

[0065]

Embedded image (Wherein, R ¹ represents a methyl group, an ethyl group, a 2-hydroxyethyl group or a 2-chloroethyl group, R ² represents a methyl group, an ethyl group, a benzyl group or a phenyl group, and R ³ represents a hydrogen atom , Chlorine atom, bromine atom, carbon number 1
4 represents an alkyl group, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. )

[0066]

Embedded image (Where Ar is a naphthalene ring, an anthracene ring,
Represents a styryl ring and a substituted product thereof, or a pyridine ring, a furan ring or a thiophene ring, and R represents an alkyl group or a benzyl group. )

[0067]

Embedded image (Wherein, R ¹ represents an alkyl group, a benzyl group, a phenyl group, a naphthyl group, R ₂ represents a hydrogen atom,
Represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group, a diaralkylamino group or a diarylamino group; n represents an integer of 1 to 4;
In the above case, R ² may be the same or different. R ³ represents a hydrogen atom or a methoxy group. )

[0068]

Embedded image (Wherein, R ₁ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group,
R ^2, R ³ may be different from each other in the same, represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, chloroalkyl group, or a substituted or unsubstituted aralkyl group, also, R ² And R ³ may combine with each other to form a nitrogen-containing heterocyclic ring. R ⁴ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group or a halogen atom. )

Embedded image (In the formula, R ¹ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a phenyl group, and R ² represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or a halogen atom.)

[0069]

Embedded image (Wherein, R represents a hydrogen atom or a halogen atom, Ar represents a substituted or unsubstituted phenyl group, a naphthyl group,
Represents an anthryl group or a carbazolyl group. )

[0070]

Embedded image (Wherein, R ₁ represents a hydrogen atom, a halogen atom, a cyano group, an alkoxy group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and Ar represents

Embedded image R ² represents an alkyl group having 1 to 4 carbon atoms; R ³ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a dialkylamino group; Or 2 and when n is 2, R ³ may be the same or different, and R ⁴ and R ^{5 each} represent a hydrogen atom,
Substitutions 4 to 4 also represent an unsubstituted alkyl group or a substituted or unsubstituted benzyl group. )

[0071]

Embedded image (Wherein, R is a carbazolyl group, a pyridine group, a thienyl group, an indolyl group, a furyl group or a substituted or unsubstituted phenyl group, a styryl group, a naphthyl group or an anthryl group, and these substituents are 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.)

[0072]

Embedded image (Wherein, R ¹ represents a lower alkyl group, a substituted or unsubstituted phenyl group or a benzyl group, and R ² and R ³
Represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group or an amino group substituted with a lower alkyl group or a benzyl group;
Or an integer of 2. )

[0073]

Embedded image (Wherein, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ² and R ³ represent an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ⁴ represents a hydrogen atom or a substituted or unsubstituted phenyl group;
r represents a substituted or unsubstituted phenyl group or a naphthyl group. )

[0074]

Embedded image (Where n is an integer of 0 or 1, R ¹ is a hydrogen atom,
Represents an alkyl group or a substituted or unsubstituted phenyl group, Ar ¹ represents a substituted or unsubstituted aryl group,
R ⁵ represents an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group;

Embedded image9-anthryl group or substituted or unsubstituted carbazolyl
A group represented by R^TwoRepresents a hydrogen atom, an alkyl group,
Lucoxy group, halogen atom Represents an aralkyl group or a substituted or unsubstituted aryl group
Then R^ThreeAnd R^FourMay be the same or different, and
M may be an integer of 0, 1, 2, or 3.
If m is 2 or more, R^TwoAre the same but different
You may. When n is 0, A and R¹Is a joint ring
It may be formed. ]

[0075]

Embedded image (Wherein, R ¹ , R ² and R ³ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a dialkylamino group or a halogen atom, and n represents 0 or 1)

[0076]

Embedded image (Wherein, R ¹ and R ² represent an alkyl group including a substituted alkyl group, or a substituted or unsubstituted aryl group;
A represents a substituted amino group, a substituted or unsubstituted aryl group or an allyl group. )

[0077]

Embedded image (Wherein, X represents a hydrogen atom, a lower alkyl group, a halogen atom, R represents an alkyl group including a substituted alkyl group,
Or A represents a substituted or unsubstituted aryl group, and A represents a substituted amino group or a substituted or unsubstituted aryl group. )

[0078]

Embedded image (However, in the formula, R ¹ represents a lower alkyl group, a lower alkoxy group or a halogen atom, n represents an integer of 0 to 4, R ² and R ³ may be the same or different, and a hydrogen atom,
Represents a lower alkyl group, a lower alkoxy group or a halogen atom. )

[0079]

Embedded image (Wherein, R ¹ , R ³ and R ⁴ represent a hydrogen atom, amino group, alkoxy group, thioalkoxy group, aryloxy group, methylenedioxy group, substituted or unsubstituted alkyl group, halogen atom or substituted or In the unsubstituted aryl group, R ² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or a halogen atom, provided that R ¹ ,
R ² , R ^3, and R ⁴ exclude the case where all are hydrogen atoms.
Further, k, l, m and n are integers of ¹ , ² , 3 or 4, and when each is an integer of 2, 3 or 4, the above R ¹ , R ² , R
³ and R ⁴ may be the same or different. )

[0080]

Embedded image (Wherein, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms, and R ¹ and R ² represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a substituted Or an unsubstituted phenyl group, which may be the same or different.)

A-CH = CH-Ar-CH = CH-A wherein Ar is a substituted or unsubstituted aromatic carbon
A represents a hydrogen group, and A is (Where Ar 'is a substituted or unsubstituted aromatic hydrocarbon
R represents a group¹And R^TwoIs a substituted or unsubstituted alkyl
Group or a substituted or unsubstituted aryl group)
You. ]

[0081]

Embedded image (Wherein, Ar represents an aromatic hydrocarbon group, R represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, and n represents 0 or 1,
m is 1 or 2, and when n = 0 and m = 1, Ar and R may form a ring together. )

Compounds represented by the general formula 14 include, for example, 9-ethylcarbazole-3-aldehyde-1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde-1-benzyl-1-phenylhydrazone. , 9-ethylcarbazole-3-aldehyde-
Examples include 1,1-diphenylhydrazone. Compounds represented by general formula 15 include, for example, 4-diethylaminostyryl-β-aldehyde-1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-aldehyde-1-benzyl-1-phenylhydrazone and the like. There is.

The compound represented by the general formula 29 includes, for example, 4-methoxybenzaldehyde-1-methyl-1
-Phenylhydrazone, 2,4-dimethoxybenzaldavido-1-benzyl-1-phenylhydrazone, 4-
Diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-methoxybenzaldehyde-1-benzyl-1- (4-methoxy) phenylhydrazone, 4-
Diphenylaminobenzaldehyde-1-benzyl-1
-Phenylhydrazone, 4-dibenzylaminobenzaldehyde-1,1-diphenylhydrazone and the like.
Compounds represented by general formula 16 include, for example, 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane,
Examples include 1,1-bis (4-dibenzylaminophenyl) propane and 2,2'-dimethyl-4,4'-bis (diethylamino) -triphenylmethane. Examples of the compound represented by the general formula 30 include N-ethyl-3,6-tetrabenzylaminocarbazole.

The compounds represented by the general formula 17 include, for example, 9- (4-diethylaminostyryl) anthracene and 9-bromo-10- (4-diethylaminostyryl) anthracene. Examples of the compound represented by the general formula 31 include 9- (4-dimethylaminobenzylidene) fluorene and 3- (9-fluorenylidene) -9-ethylcarbazole.

The compounds represented by the general formula 33 include, for example, 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene. Compounds represented by general formula 18 include, for example, 3-styryl-9-ethylcarbazole,
3- (4-methoxystyryl) -9-ethylcarbazole and the like.

Compounds represented by the general formula 19 include, for example, 4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene,
-(4-diphenylaminostyryl) naphthalene, 1-
(4-Diethylaminostyryl) naphthalene and the like. Compounds represented by general formula 20 include, for example, 4 ′
-Diphenylamino-α-phenylstilbene, 4′-
And bis (methylphenyl) amino-α-phenylstilbene.

The compounds represented by the general formula 34 include, for example, 1-phenyl-3- (4-diethylaminostyryl) -5- (4-diethylaminophenyl) pyrazoline, 1-phenyl-3- (4-dimethylaminostyryl) ) -5- (4-dimethylaminophenyl) pyrazoline and the like. Compounds represented by general formula 35 include, for example, 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, 2-N, N-diphenylamino-5- ( 4-diethylaminophenyl)
-1,3,4-oxadiazole, 2- (4-dimethylaminophenyl) -5- (4-diethylaminophenyl) -1,3,4-oxadiazole and the like.

As the compound represented by the general formula 36,
For example, 2-N, N-diphenylamino-5- (N-ethylcarbazol-3-yl) -1,3,4-oxadiazole, 2- (4-diethylaminophenyl) -5
(N-ethylcarbazol-3-yl) -1,3,4-
Oxadiazole and the like. Compounds represented by general formula 22 include N, N'-diphenyl-N, N '
-Bis (3-methylphenyl)-[1,1'-bisphenyl] -4,4'-diamine, 3,3'-dimethyl-
N, N, N ', N'-tetrakis (4-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine and the like.

The biphenylamine compound represented by the general formula (23) includes, for example, 4′-methoxy-N, N-diphenyl- [1,1′-biphenyl] -4-amine, 4′-
Methyl-N, N'-bis (4-methylphenyl)-
[1,1′-biphenyl] -4-amine, 4′-methoxy-N, N′-bis (4-methylphenyl)-[1,
1'-biphenyl] -4-amine and the like. Further, the triarylamine compound represented by the general formula 24 includes:
For example, there are 1-phenylaminopyrene, 1-di (p-tolylamino) pyrene and the like.

The diolefin aromatic compounds represented by the general formula 25 include, for example, 1,4-bis (4-diphenylaminostyryl) benzene, 1,4-bis [4-di (p-tolyl) amino [Styryl] benzene.
Examples of the styrylpyrene compound represented by the general formula 37 include 1- (4-diphenylaminostyryl) pyrene and 1- [4-di (p-tolyl) aminostyryl] pyrene.

These charge transporting substances can be used alone or in combination of two or more. In the present invention,
Oxidation potential +0.5 V (vs. SC
E) It is preferable to use the above-mentioned compounds. Among them, by using the compounds represented by the general formulas 14 to 20 and 22 to 25 to form an electrophotographic photoreceptor, in terms of chargeability and photosensitivity, It will be excellent. In particular, an electrophotographic photoreceptor using the compound represented by the general formula (16) is preferable since it has a particularly excellent charge stability when repeatedly used as compared with other photoreceptors. The oxidation potential of the charge transporting material in the present invention is a half-wave potential in a generally known cyclic voltametery measurement, and the conditions are acetonitrile as a solvent, 0.1 M TEAP as an electrolyte, and a reference electrode. This is a value when a saturated calomel electrode (SCE) is used.

Hereinafter, the present invention will be described with reference to FIGS. 1 to 4. Reference numeral 1 denotes a conductive support, and 2 denotes a photoconductive layer according to the present invention. The electrophotographic photoreceptor of the present invention, as shown in FIGS.
As long as the photoconductive layer is a single layer type, any form may be used, and an undercoat layer 3 may be provided between the photoconductive layer and the conductive support in order to improve adhesion and charge blocking properties. Further, a protective layer 4 may be provided on the photoconductive layer in order to improve mechanical durability such as abrasion resistance.

Examples of the conductive support used in the electrophotographic photoreceptor of the present invention include metals or alloys such as aluminum, brass, stainless steel, and nickel, and insulating supports such as polyethylene terephthalate, polypropylene, nylon, glass, and paper. Metals such as aluminum, silver, gold and nickel or conductive materials such as indium oxide and tin oxide formed on the thin film, carbon black, indium oxide,
Examples thereof include a material in which a conductive powder such as tin oxide is dispersed in an appropriate resin to form a film, a paper subjected to a conductive treatment, and the like. The shape of the conductive support is not particularly limited, and a plate-like, drum-like, or belt-like material is used as necessary.

As the binder resin used in the present invention, known resins are used, and a high molecular polymer having an insulating property and a high film forming ability is preferable. For example, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, Polyarylate resin, polycarbonate (bisphenol A
Type, bisphenol Z type), cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-
Vinyl carbazole, acrylic resin, silicone resin,
Examples include, but are not limited to, thermoplastic or thermosetting resins such as epoxy resins, melamine resins, urethane resins, phenolic resins, and alkyd resins.

To prepare the electrophotographic photosensitive member of the present invention,
The disazo pigment and the trisazo pigment were simultaneously mixed and pulverized by the above method, a charge transporting substance, a binder resin was added and mixed, and a dip coating method or a spray coat method or a bead coat method was used on the conductive support. It may be applied. Examples of the solvent for mixing and grinding include ketones, esters, alcohols, cyclic ethers, cyclic ketones, and the like. Preferably, cyclic ethers, cyclic ketones, and more preferably, tetrahydrofuran and cyclohexanone are used in view of the sensitizing effect. it can.

The ratio of the charge-generating substance and the binder resin used in the present invention is preferably in the range of 0.01 to 10 parts by weight based on 10 parts by weight of the simultaneously pulverized mixture of the azo pigment and the binder resin. If it is less than the above range, the residual potential is large, and if it is more than the above range, the chargeability and the mechanical strength decrease. The ratio of the charge transport material and the binder resin used in the present invention is,
The charge transporting material is preferably in the range of 1 to 15 parts by weight based on 10 parts by weight of the binder resin. When the amount is less than the above range, the sensitivity is lowered, and when the amount is more than the above range, the charging property and the mechanical strength are deteriorated.

The photoconductive layer of the present invention has a thickness of 5 to 100 μm.
m, preferably in the range of 10 to 50 μm. 5μ
When the thickness is smaller than m, there is no mechanical durability, and when the thickness is larger than 100 μm, the residual potential increases.

[0098]

Next, the present invention will be described in more detail by way of examples.

Example 1 Coupler No. 1 was used as a charge generating substance. 17 and no. 24
5 parts by weight of an asymmetric disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) using a coupler No. Chemical formula 2 using 70
5 parts by weight of a trisazo pigment represented by the formula (R ³ = H) were dispersed in a ball mill for 5 days together with 70 parts by weight of methyl ethyl ketone and subjected to simultaneous pulverization and mixing treatment, and 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000, tetrahydrofuran 300 parts by weight, 80 parts by weight of 4-diethylaminobenzaldehyde-1-benzyl-1-phenylhydrazone represented by Chemical formula 29 as a charge transporting substance, and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)] In addition, a coating solution for a photosensitive layer was prepared. The coating solution for the photosensitive layer thus obtained was coated with a thickness of 0.2 mm.
Aluminum plate [A1080 (manufactured by Sumitomo Light Metal Co., Ltd.)] with a blade, dried at 150 ° C. for 20 minutes, and
A photosensitive layer having a thickness of μm was formed, and an electrophotographic photosensitive member of Example 1 was prepared. In addition, when the oxidation potential of the charge transporting substance used in Example 1 was measured by the method described above, it was 0.50 V (v
s SCE).

Example 2 In Example 1, the asymmetric disazo pigment was prepared using coupler No. An electrophotographic photoreceptor of Example 2 was prepared in the same manner as in Example 1, except that the disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) was used.

Example 3 In Example 1, the trisazo pigment was replaced with a coupler N
o. An electrophotographic photoreceptor of Example 3 was prepared in the same manner as in Example 1, except that the trisazo pigment represented by Chemical Formula 2 (R ³ = H) was used.

Example 4 In Example 1, the asymmetric disazo pigment was prepared using coupler No. An electrophotographic photoreceptor of Example 4 was prepared in the same manner as in Example 1, except that the symmetric disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) was used.

Example 5 In Example 1, the trisazo pigment was replaced with a coupler N
o. Example 5 was repeated in the same manner as in Example 1 except that the trisazo pigment represented by Chemical Formula 2 (R ³ = H) was used.
Was prepared.

Example 6 In Example 1, the input amounts of the asymmetric disazo pigment and the trisazo pigment as the charge generating substances were each set at 0.04.
An electrophotographic photosensitive member of Example 6 was prepared in the same manner as in Example 1 except that the parts were changed to parts by weight and 0.04 parts by weight.

Example 7 In Example 1, the amount of each of the asymmetric disazo pigment and the trisazo pigment, which were the charge generating substances, was 0.05
An electrophotographic photosensitive member of Example 7 was prepared in the same manner as in Example 1 except that the parts were changed to parts by weight and 0.05 parts by weight.

Example 8 Example 8 was carried out in the same manner as in Example 1 except that the amounts of the asymmetric disazo pigment and the trisazo pigment, which were the charge generating substances, were changed to 50 parts by weight and 50 parts by weight, respectively. Was prepared.

Example 9 Example 9 was carried out in the same manner as in Example 1 except that the amounts of the asymmetric disazo pigment and the trisazo pigment, which were the charge generating substances, were changed to 75 parts by weight and 75 parts by weight, respectively. Was prepared.

Example 10 An electrophotographic photosensitive member of Example 10 was prepared in the same manner as in Example 1, except that the amount of the charge generating substance was changed to 5 parts by weight.

Example 11 An electrophotographic photosensitive member of Example 11 was prepared in the same manner as in Example 1, except that the amount of the charge generating substance was changed to 10 parts by weight.

Example 12 An electrophotographic photosensitive member of Example 12 was prepared in the same manner as in Example 1, except that the amount of the charge generating substance was changed to 150 parts by weight.

Example 13 An electrophotographic photosensitive member of Example 13 was prepared in the same manner as in Example 1, except that the amount of the charge generating substance was changed to 200 parts by weight.

Example 14 Example 1 was repeated in the same manner as in Example 1 except that methyl ethyl ketone was changed to 1,4-dioxane.
4 was prepared.

Example 15 An electrophotographic photosensitive member of Example 15 was prepared in the same manner as in Example 1, except that methylethylketone was changed to isophorone.

Example 16 Example 1 was repeated in the same manner as in Example 1 except that methyl ethyl ketone was changed to tetrahydrofuran.
6 was prepared.

Example 17 Example 17 was carried out in the same manner as in Example 1, except that methyl ethyl ketone was changed to cyclohexanone.
Was prepared.

Comparative Example 1 Coupler No. 1 was used as a charge generating substance. 17 and no. 24
5 parts by weight of an asymmetric disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) using a coupler No. Chemical formula 2 using 70
5 parts by weight of a trisazo pigment represented by the formula (R ³ = H) were separately dispersed in a ball mill for 5 days together with 35 parts by weight of methyl ethyl ketone, and then they were mixed. The mixture was mixed with 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000. Department,
To a solution comprising 300 parts by weight of tetrahydrofuran, 80 parts by weight of the compound used in Example 1 as a charge transport material, and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)], was added a coating for a photosensitive layer. A liquid was made. The coating liquid for a photosensitive layer thus obtained was formed into a film in the same manner as in Example 1, and an electrophotographic photosensitive member of Comparative Example 1 was prepared.

Comparative Example 2 Coupler No. 1 was used as a charge generating substance. 17 and no. 24
10 parts by weight of an asymmetric disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) was dispersed in a ball mill for 5 days together with 70 parts by weight of methyl ethyl ketone, and this was dispersed in 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000. , 300 parts by weight of tetrahydrofuran, 80 parts by weight of the compound used in Example 1 as a charge transporting substance, silicone oil [KF-50
(Manufactured by Shin-Etsu Chemical Co., Ltd.)] A coating solution for a photosensitive layer was prepared in addition to the solution consisting of 0.1 parts by weight. The coating liquid for a photosensitive layer thus obtained was formed into a film in the same manner as in Example 1, and Comparative Example 2
Was prepared.

Comparative Example 3 Coupler No. 1 was used as the charge generating substance. Chemical formula 2 using 70
10 parts by weight of a trisazo pigment represented by (R ³ = H) was dispersed in a ball mill for 5 days together with 70 parts by weight of methyl ethyl ketone, and 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000, 300 parts by weight of tetrahydrofuran,
A coating solution for a photosensitive layer was prepared by adding a solution comprising 80 parts by weight of the compound used in Example 1 as a charge transport material and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)]. The coating liquid for a photosensitive layer thus obtained was formed into a film in the same manner as in Example 1 to prepare an electrophotographic photoreceptor of Comparative Example 3.

The electrostatic characteristics of the electrophotographic photosensitive member obtained as described above were measured at 25 ° C./50% RH under EPA-8.
100 (manufactured by Kawaguchi Electric Works) was measured by a dynamic method. First, after charging at an applied voltage of +6 KV for 10 seconds, dark decay was performed for 20 seconds, and exposure was performed for 30 seconds with white light from a halogen lamp at a surface illuminance of 10 lux. Similarly, charging and dark decay were performed, and exposure was also performed using a 780 nm monochromatic light source with a surface illuminance of 10 μW / cm ² . The charging potential is the surface potential V ₂ (V) 2 seconds after charging.
And the sensitivity is that the surface potential after exposure is 2 times the surface potential immediately before exposure.
Exposure E _1/2 (lux · sec)
[White light]) and E _1/2 (μJ / cm ² [monochromatic light])
The residual potential is the surface potential V 30 seconds after exposure with each light source.
₃₀ (V) was measured. Table 18 shows the results.

[0120]

[Table 18]

[Examples 18 to 38] In Example 1,
Electrophotographic photoreceptors of Examples 18 to 38 were prepared in the same manner as in Example 1 except that the charge transporting material was changed to a charge transporting material as shown in Table 19 below.

[0122]

[Table 19]

Examples 18 to 3 obtained as described above
8, and the electrostatic characteristics of the electrophotographic photosensitive member of Example 1 were set to 25 ° C.
The measurement was performed by a dynamic method using EPA-8100 (manufactured by Kawaguchi Electric Works) in an environment of / 50% RH. First, after charging at an applied voltage of +6 KV for 10 seconds, dark decay for 20 seconds and white light from a halogen lamp with a surface illuminance of 1
Exposure was performed for 10 seconds at 0 lux. The charging potential is the saturation surface potential Vm (V) for 10 seconds of charging,
The sensitivity was measured by measuring the exposure amount E1 / 2 (lux · sec [white light]) required for the surface potential after exposure to be の of the surface potential immediately before exposure. Table 20 shows the results. Also,
FIG. 5 shows a plotted result of the saturated surface potential Vm.

[0124]

[Table 20]

Further, Embodiments 1, 20, and 2
For the electrophotographic photoreceptor of No. 8,
This was repeated 000 times, and the stability of the electrostatic characteristics was evaluated. Table 21 shows the results.

[0126]

[Table 21]

As is apparent from the above results, when the oxidation potential of the charge transporting material becomes +0.5 V (vs SCE) or less, the charging performance rapidly decreases. In Examples 18 to 32 using the charge transport materials represented by the general formulas 14 to 20, and 22 to 25, the chargeability was good,
And it turns out that it is advantageous with respect to light sensitivity. Example 2 Using a Charge-Transporting Material Represented by General Formula 16
The electrophotographic photoreceptor 1 is excellent particularly in terms of charging stability at the time of repeated use.

Comparative Example 4 Coupler No. 1 was used as a charge generating substance. 17 and no. 24
5 parts by weight of an asymmetric disazo pigment represented by Chemical Formula 1 (R ¹ = R ² = H) using a coupler No. Chemical formula 2 using 70
5 parts by weight of a trisazo pigment represented by (R ³ = H) and 70 parts by weight of cyclohexanone were dispersed in a ball mill for 5 days, and further diluted with 420 parts by weight of cyclohexanone.
A coating solution for the charge generation layer was prepared. The coating liquid for a charge generation layer obtained in this manner is blade-coated on the above-mentioned aluminum plate, dried at 100 ° C. for 10 minutes, and has a thickness of 0.3 μm.
m of the charge generation layer was formed. Next, 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000, 80 parts by weight of the compound used in Example 1 as a charge transporting substance, and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)] were added to dichloromethane. It was dissolved in 300 parts by weight to prepare a coating liquid for a charge transport layer. The charge transport layer coating solution thus obtained was coated on the charge generation layer with a blade and dried at 150 ° C. for 20 minutes to form a charge transport layer having a thickness of 20 μm. Created body.

The thus obtained multilayer electrophotographic photosensitive member of Comparative Example 4 and the single-layer electrophotographic photosensitive member of Example 17 were measured for spectral sensitivity by a static method. -600 V for the laminated electrophotographic photosensitive member of Comparative Example 4,
The applied voltage of the electrophotographic photoreceptor of Example 17 was adjusted so as to be +600 V, and thereafter, a monochromator (manufactured by Nikon) was used for 900 nm to 400 nm (20 n).
Irradiated with monochromatic light that has been split in m units, the sensitivity (V ·
cm ² / μJ). FIG. 6 shows the result.

As a result, the single-layer type photoreceptor of Example 17 according to the present invention has a higher spectral stability in a wide range of exposure wavelengths from a long wavelength to a short wavelength than the laminated type photoreceptor of Comparative Example 4. It turns out that it shows sensitivity.

[0131]

As described above, the electrophotographic photoreceptor of the present invention comprises a specific pulverized mixture of a disazo pigment and a trisazo pigment, a charge transport material, and a binder resin in a single photoconductive layer. It has been found that the high sensitivity to light in a wide range from the visible region to the near-infrared region.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an electrophotographic photosensitive member according to the present invention, in which a single photoconductive layer is provided on a conductive support.

FIG. 2 is a schematic diagram showing an example of the electrophotographic photoreceptor according to the present invention, in which an undercoat layer is provided between a conductive support and a photoconductive layer.

FIG. 3 is a schematic view showing an example of the electrophotographic photosensitive member according to the present invention, in which a protective layer is provided on a photoconductive layer.

FIG. 4 is a schematic view showing an example of the electrophotographic photosensitive member according to the present invention, in which an undercoat layer and a protective layer are provided at the same time.

FIG. 5 is a graph showing a charging potential of the electrophotographic photosensitive member according to the present invention.

FIG. 6 is a graph showing the spectral sensitivities of the electrophotographic photosensitive members according to Example 17 and Comparative Example 4.

[Description of Signs] 1 conductive support 2 photoconductive layer 3 undercoat layer 4 protective layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI G03G 5/06 322 G03G 5/06 322 324 324A 324B 360 360 360C 367 367 No. 3-6 Ricoh Co., Ltd. (72) Inventor Masaomi Sasaki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-5-297610 (JP, A) JP-A-5-297611 (JP, A) JP-A-4-310964 (JP, A) JP-A-1-302260 (JP, A) JP-A-58-122544 (JP, A) JP-A-4-195055 ( JP, A) JP-A-63-159857 (JP, A) JP-A-58-117551 (JP, A) JP-A-58-122546 (JP, A) JP-A-5-150488 (JP, A) Hei 5-127407 (J JP-A-1-142644 (JP, A) JP-A-2-178668 (JP, A) JP-A-3-56967 (JP, A) JP-A-5-158248 (JP, A) 2-272569 (JP, A) JP-A-54-60928 (JP, A) JP-A-4-136864 (JP, A) JP-A-2-226257 (JP, A) JP-A 64-25748 (JP, A) A) JP-A-1-273050 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 5/00

Claims (19)

(57) [Claims] 1. An electrophotographic photoreceptor comprising a photoconductive layer formed on a conductive support, wherein the photoconductive layer comprises at least one disazo pigment represented by the following general formula (1): An electrophotographic photoreceptor comprising a single layer containing a co-ground mixture with at least one trisazo pigment represented by the general formula 2, a charge transport material, and a binder resin. Embedded image Embedded image ｛However, in the above chemical formulas 1 and 2, Ar ¹ , Ar ² and Ar ³ are
Represents a coupler residue represented by the following general formulas 3 to 10, which may be the same or different. R ¹ and R ² represent a hydrogen atom, a halogen atom, a trifluoromethyl group, a nitro group, or a cyano group, and R ³ represents a hydrogen atom, a chlorine atom, a fluorine atom, an iodine atom, a bromine atom, -NO ₂ Or -CN
Is shown. Embedded image Wherein X ¹ , Y ¹ and Z each represent the following. X ¹ : —OH, —N (R ⁴ ) (R ⁵ ), or —NHSO ₂ —
R ⁶ (however, R ⁴ and R ⁵ represent a hydrogen atom, an acyl group, or a substituted or unsubstituted alkyl group, and R ⁶ represents a substituted or unsubstituted aryl group.) Y ¹ : a hydrogen atom, a halogen atom a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group, a sulfonic group, benzimidazolyl group, a substituted or unsubstituted sulfamoyl group, or ^{-CON (R 7) (Y 2} ).
(However, R ⁷ represents a hydrogen atom, an alkyl group or a substituted product thereof, or a phenyl group or a substituted product thereof, and Y ² represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or —N = C (R ⁸ ) (R ⁹ ) << R ⁸
Is a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof, or a styryl group or a substituted product thereof, R
⁹ is a hydrogen atom, an alkyl group or a substituent thereof, or
Represents a phenyl group or a substituent thereof, or represents R ⁸
And R ⁹ may form a ring with the carbon atom to which they are attached. >>. Z: represents a hydrocarbon ring group or a substituted product thereof, a heterocyclic group or a substituted product thereof. [Formula 4] Wherein R ¹⁰ , R ¹¹ , Y ¹ and n each represent the following. n: an integer of 1 to 4, R ¹⁰ : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, R ¹¹ : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy Group, substituted or unsubstituted alkylsulfonyl group, substituted or unsubstituted alkylmercapto group, halogen atom, substituted or unsubstituted aryl group, substituted or unsubstituted acyl group, cyano group, nitro group, and substituted or unsubstituted Wherein n is an integer of 2 to 4, R ¹¹ may be the same or different. Y ¹ represents the same as in the above formula 3. [Chemical formula 5] Embedded image [However, in Formulas 5 and 6, R ¹² represents a substituted or unsubstituted hydrocarbon group. [Formula 7] Embedded image [However, in Formulas 7 and 8, R ¹³ represents an alkyl group, a carbamoyl group, a carboxy group, or an ester thereof, and Ar ⁴ represents a substituted or unsubstituted aromatic hydrocarbon group. Embedded image Embedded image [However, in the formulas 9 and 10, X ² represents a divalent group of an aromatic hydrocarbon or a divalent group of a heterocyclic ring. ]｝ 2. The trisazo pigment according to the general formula 11
The electrophotographic photoreceptor according to claim 1, which is a compound represented by the formula: Embedded image (Wherein, R ^{1 to} R ⁹ are a hydrogen atom, —CH ₃ , —C
_{2 H 5, -C 3 H 7} , a chlorine atom, a fluorine atom, an iodine atom,
A bromine _{atom, CH 3 -, C 2 H} 5 O-, C 3 H 7 O -, - N
Represents O ₂ , —CN, —CF ₃ or —OH. ) 3. The electrophotographic photoconductor according to claim 1, wherein the disazo pigment is a compound represented by the following general formula (12) and / or (13). Embedded image Embedded image 4. The electrophotographic photoreceptor according to claim 1, wherein the simultaneously pulverized mixture of the azo pigment is contained in an amount of 0.01 to 10 parts by weight based on 10 parts by weight of the binder resin. . 5. The electrophotographic photoreceptor according to claim 1, wherein the charge transporting material is contained in an amount of 1 to 15 parts by weight based on 10 parts by weight of the binder resin. 6. The method according to claim 1, wherein the charge transport material has an oxidation potential of +0.5 V (vs.
2. The electrophotographic photoreceptor according to claim 1, which is a compound exceeding SCE). 7. The charge transport material according to the following general formula 14
The electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one in oxidation potential + 0.5V (VS SEC) the excess compound represented. Embedded image (However, in Formula 14, R ¹ represents a methyl group, an ethyl group,
Represents a hydroxyethyl group or a 2-chloroethyl group;
² represents a methyl group, an ethyl group, a benzyl group or a phenyl group, and R ³ represents a hydrogen atom, a bromine atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. Represent. ) 8. The charge transport material according to the general formula 15
The electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding oxidation potential + 0.5V (vs SEC) THAT represented. Embedded image (However, in the formula, Ar represents a naphthalene ring, an anthracene ring, a styryl ring or a substituted product thereof, or a pyridine ring, a furan ring, or a thiophene ring, and R represents an alkyl group or a benzyl group.) 9. The charge transport material according to the general formula 16
The electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding oxidation potential + 0.5V (vs SEC) THAT represented. Embedded image (Wherein, R ¹ represents an alkyl group having 1 to 11 carbon atoms, a substituted or unsubstituted phenyl group or a heterocyclic group;
² and R ³ may be the same or different, represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, chloroalkyl group, or a substituted or unsubstituted aralkyl group, also, R ² and R ³ may combine with each other to form a heterocyclic ring containing a nitrogen atom. R ⁴ may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, or a halogen atom. ) 10. The charge transport material according to the following general formula 1.
Oxidation potential + 0.5V (vs SEC) electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding represented by 7. Embedded image (In the formula, R represents a hydrogen atom or a halogen atom, and Ar represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, or carbazolyl group.) 11. The charge transport material according to the following general formula 1
Oxidation potential + 0.5V (vs SEC) electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding represented by 8. Embedded image (Wherein, R ¹ represents a lower alkyl group, a substituted or unsubstituted phenyl group or a benzyl group, and R ² and R ³ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a halogen atom, a nitro group, an amino group Group or an amino group substituted by a lower alkyl group or a benzyl group, n is 1 or
Represents an integer of 2. ) 12. The charge transport material according to the following general formula 1
Oxidation potential + 0.5V (vs SEC) electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding represented by 9. Embedded image (Wherein, R ¹ represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ² and R ³ represent an alkyl group,
Represents a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ⁴ represents a hydrogen atom, a lower alkyl group or a substituted or unsubstituted phenyl group, and Ar represents a substituted or unsubstituted phenyl group or Represents a naphthyl group. ) 13. The charge transport material according to the following general formula 2:
7. The electrophotographic photoreceptor according to claim 6, wherein the electrophotographic photoreceptor contains at least one compound having an oxidation potential represented by 0 and exceeding 0.5 V (vs SEC). Embedded image (Wherein, n is an integer of 0 or 1, R ¹ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group, and Ar
¹ represents a substituted or unsubstituted aryl group; R ⁵ represents an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group; Represents a 9-anthryl group or a substituted or unsubstituted N-alkylcarbazolyl group, wherein R ² is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or —N (R ³ )
(R ⁴ ) (provided that R ³ and R ⁴ represent an alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group, and R ³ and R ⁴ may be the same or different; M may be an integer of 0, 1, 2, or 3, and when m is 2 or more, R ² may be the same or different. When n is 0, A and R ¹ may form a ring together. ] 14. The charge transport material according to the following general formula 2:
The electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one oxidation potential + 0.5V (vs SEC) the excess compound represented by 2. Embedded image (However, in the formula, R ¹ represents a lower alkyl group, a lower alkoxy group or a halogen atom, n represents an integer of 0 to 4, R ² and R ³ may be the same or different, and a hydrogen atom,
Represents a lower alkyl group, a lower alkoxy group or a halogen atom. ) 15. The charge transport material according to the following general formula 2:
Oxidation potential + 0.5V (vs SEC) electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding represented by 3. Embedded image (Wherein, R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted or unsubstituted An aryl group, R ² is a hydrogen atom,
Represents an alkoxy group, a substituted or unsubstituted alkyl group or a halogen atom. However, this excludes the case where R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms. K, l, m and n are 1, 2,
R ¹ , R ² , R ³ and R ⁴ may be the same or different when each is an integer of 2, 3 or 4. ) 16. The charge transport material according to the following general formula 2:
Oxidation potential + 0.5V (vs SEC) electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one compound exceeding represented by 4. Embedded image (Wherein, Ar represents a condensed polycyclic hydrocarbon group having 18 or less carbon atoms, and R ¹ and R ² are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group,
Represents a substituted or unsubstituted phenyl group, which may be the same or different. ) 17. The charge transport material according to the following general formula 2:
The electrophotographic photosensitive member according to claim 6, characterized in that it contains at least one 5 in the oxidation potential + 0.5V (vs SEC) the excess compound represented. A-CH = CH-Ar-CH = CH-A wherein Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and A represents -Ar'-N (R ¹ ) (R ² ) (where Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ¹ and R ² represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). ] 18. The electron according to claim 1, wherein the simultaneously pulverized mixture of the azo pigments has been subjected to a simultaneous pulverization and mixing treatment using at least one of a cyclic ether and a cyclic ketone as a dispersion solvent. Photoreceptor. 19. The electrophotographic photosensitive member according to claim 1, wherein the simultaneously pulverized mixture of the azo pigments has been subjected to simultaneous pulverization and mixing using at least one of tetrahydrofuran and cyclohexanone as a dispersion solvent. body.