JP2001154382A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single layer-type electrophotographic photoreceptor having high sensitivity from the visible region to the near IR region, excellent electrostatic characteristics without decrease or increase in the electrification potential even for repeated use, showing no decrease in the image density nor contamination of the base, and having a long life and high reliability. SOLUTION: In the electrophotographic photoreceptor having a photoconductive layer on a conductive supporting body, the photoconductive layer is a single layer containing at least one disazo pigment expressed by general formula (I), μ-oxo-gallium phthalocyanine dimer pigment, charge transfer material and binder resin. In formula (I), each of A and B represents a specified coupler residue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used for a copying machine, a printer and the like, and more particularly to a single-layer type electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Inorganic substances such as selenium, cadmium sulfide, and zinc oxide are known as photoconductive substances used in electrophotographic photoreceptors. These inorganic substances are required for photosensitivity and thermal stability required for electrophotographic photoreceptors. It is not always satisfactory in characteristics such as durability, durability, and manufacturing conditions. For example, selenium has drawbacks in that it tends to crystallize due to heat, dirt, and the like, and its properties are easily degraded. Further, it requires special handling such as manufacturing cost, impact resistance, toxicity, and the like. Electrophotographic photoreceptors using cadmium sulfide have poor moisture resistance and durability, and have toxicity problems. Zinc oxide also has the disadvantage of being inferior in moisture resistance and durability.

[0003] In contrast to the electrophotographic photoreceptors using these inorganic photoconductive substances, the electrophotographic photoreceptors using an organic photoconductive substance are easier to form, have higher manufacturing costs, or have a wider range of variations as organic compounds. From now on, research and development can be actively carried out. As an electrophotographic photoreceptor using an organic photoconductive substance, a function-separated type electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are laminated, and a single layer type in which a charge generation substance is dispersed in a resin binder. Electrophotographic photoreceptors and the like are enumerated, and among them, a laminated electrophotographic photoreceptor occupies the mainstream in terms of high sensitivity. For example, as a laminated electrophotographic photoreceptor, there are many electrophotographic photoreceptors including a charge generation layer containing chlordiane blue and a charge transport layer containing a hydrazone compound described in JP-B-55-42380. The charge generating substances are known as JP-A-53-133445, JP-A-54-21728, and JP-A-54-22834.
Japanese Unexamined Patent Publication No.
Many are known from, for example, Japanese Patent Application Laid-Open No. 198043 and Japanese Patent Application Laid-Open No. 58-199352. Most of the electrophotographic photoconductors which are practically used as electrophotographic photoconductors using an organic photoconductive substance are laminated electrophotographic photoconductors.

However, in the case of a laminated type electrophotographic photoreceptor, the charge generation layer is generally 0.1 to 1.
It is necessary to make the film thickness as thin as 0 μm, and it is easily affected by the state of the surface of the conductive substrate, the atmosphere at the time of coating, the environment, and the like, which greatly affects the yield, the manufacturing cost, and the like. In addition, the charge transporting material contained in the charge transporting layer is required to have a high charge mobility for higher sensitivity, but most of the charge transporting materials having a high charge mobility have a hole transporting property. For this reason, practically used laminated electrophotographic photosensitive members are limited to negatively charged electrophotographic photosensitive members. Most of such negatively charged electrophotographic 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 the photoreceptor material. The reaction shortens the life of the electrophotographic photosensitive member itself. 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 drawbacks such as doing.

In order to solve these drawbacks, research on a single-layer type electrophotographic photosensitive member used in a positive charging process has been promoted. Japanese Patent Publication No. 50-10496 discloses an electrophotographic photosensitive member containing polyvinyl carbazole and 2,4,7-trinitro-9-fluorenone.
Japanese Patent No. 25658 discloses an electrophotographic photosensitive member in which polyvinyl carbazole is sensitized with a pyrylium salt dye or an electrophotographic photosensitive member containing a eutectic complex as a main component.
JP-A No. 30 discloses an electrophotographic photosensitive member comprising a charge-generating substance and a charge-transporting substance, and JP-A-63-271461, JP-A-1-118143, JP-A-3-65761 and the like disclose a perylene pigment. An electrophotographic photoreceptor made of a charge transport material and an electrophotographic photoreceptor made of a phthalocyanine compound and a binder resin are disclosed in Japanese Patent Application Laid-Open No. Hei 3-65561.

[0006] In recent years, with the increase in the number and functions of copiers, electrophotographic photoconductors have been developed for copiers having analog and digital functions. In this case, the characteristics required for the electrophotographic photoreceptor are that it has high sensitivity in the near infrared region, which is the wavelength of the LD laser light source, in order to correspond to the digital function, and it also corresponds to the analog function. It is desired to have high sensitivity in the wavelength of a white light source, that is, in the visible light region. Such an electrophotographic photoreceptor is disclosed in JP-A-63-236047, JP-A-63-243950, and JP-A-63-2439.
No. 51, JP-A-1-315752, etc., have a wide spectral sensitivity from the visible region to the near infrared region by mixing a pigment having sensitivity in the visible light region and a pigment having sensitivity in the near infrared region. An electrophotographic photosensitive member as described above has been proposed.

[0007]

The conventional single-layer type electrophotographic photoreceptor has a higher electrostatic capacity than the multi-layer type electrophotographic photoreceptor, particularly in terms of sensitivity and electrostatic potential such as a decrease in charged potential and an increase in residual potential during repeated use. There is a problem that the stability of the characteristics is inferior, the image density is reduced and the background is smeared, and a single-layer electrophotographic photosensitive member having a long life and high reliability cannot be obtained. In addition, as an electrophotographic photosensitive member corresponding to a copying machine having analog and digital functions, an electrophotographic photosensitive member having a wide spectral sensitivity from a visible region to a near infrared region has been proposed. In most cases, the electrophotographic photoreceptor is configured as a stacked type.In this case, since the charge transport material in the upper layer absorbs light,
In particular, there is a problem that light sensitivity in a short wavelength range is deteriorated, and high spectral sensitivity cannot be obtained from a visible range to a near infrared range.

An object of the present invention is to solve such a problem. Therefore, an object of the present invention is to provide high sensitivity from the visible region to the near-infrared region, excellent stability of electrostatic characteristics without a decrease in charging potential or an increase in residual potential even when used repeatedly, and an image density. It is an object of the present invention to provide a single-layer type electrophotographic photoreceptor having a long life and high reliability, which does not cause a reduction in image quality and the occurrence of background contamination.

[0009]

Means for Solving the Problems The present inventors include in a photoconductive layer a specific disazo pigment having sensitivity in the visible region and a μ-oxo-gallium phthalocyanine dimer pigment having sensitivity in the near infrared region. Thereby, the disazo pigment or the μ-oxo-gallium phthalocyanine dimer pigment has a sensitizing effect equal to or greater than the sum of the sensitivities when each pigment is used alone. No decrease in sensitivity to light, high sensitivity to visible light and near-infrared light, and excellent stability of electrostatic characteristics without reduction in charging potential or increase in residual potential even during repeated use, The present inventors have found that an electrophotographic photosensitive member free of a decrease in image density and generation of background stain can be obtained, and the present invention has been accomplished.

That is, an object of the present invention is to provide an electrophotographic photoreceptor having a photoconductive layer formed on a conductive support, wherein the photoconductive layer comprises at least one of the following general formula (I): This is achieved by an electrophotographic photoreceptor characterized by comprising a single layer containing two disazo pigments, a .mu.-oxo-gallium phthalocyanine dimer pigment, a charge transport material and a binder resin.

[0011]

Embedded image

[However, in the above general formula (I), A and B
Represents a coupler residue represented by the following general formulas (II) to (VIII).

[0013]

Embedded image

Wherein, in the above general formula (II), X¹, Y¹Passing
And Z represent the following, respectively. X ¹: -OH, -N
HCOCH_ThreeOr -NHSO_TwoCH_Three. Y¹: -CON
(R^Two) (R^Three), -CONNH = C (R⁶) (R⁷),-
CONNHN (R⁸) (R⁹), -CONHCONH
(R¹²), Hydrogen atom, -COOH, -COOCH_Three, −
COOC₆H_FiveOr a benzimidazolyl group. (R^Two, R^Three
Is a hydrogen atom, a substituted or unsubstituted alkyl group,
Or unsubstituted aryl group, substituted or unsubstituted
A ring group;^Two, R^ThreeIs the nitrogen atom attached to them
Both may form a ring. R⁶, R⁷Is a hydrogen atom,
Or an unsubstituted alkyl group, a substituted or unsubstituted ara
Alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted
Or unsubstituted styryl group, substituted or unsubstituted hetero
A ring group;⁶, R⁷Together with the carbon atom to which they are attached
May form a ring. R⁸, R⁹Is a hydrogen atom,
Or unsubstituted alkyl groups, substituted or unsubstituted arals
A killed group, a substituted or unsubstituted aryl group,
Is an unsubstituted styryl group, a substituted or unsubstituted heterocycle
A group represented by R⁸, R⁹Forms a 5- or 6-membered ring
In this case, the 5- or 6-membered ring may be a fused aromatic
It may have a ring. R¹²Is a substituted or unsubstituted alk
Group, substituted or unsubstituted aryl group, substituted or
Shows an unsubstituted heterocyclic group. ) Z: bonded to a benzene ring
Naphthalene ring, anthracene ring, carbazole ring,
Nzocarbazole ring, dibenzocarbazole ring, diben
Zofran ring, benzonaphthofuran ring, and dibenzothio
Forming a polycyclic aromatic ring or hetero ring selected from phen rings
Residues needed to Even if these rings have substituents
Good. ｝

[0015]

Embedded image

(R ⁴ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.)

[0017]

Embedded image

(R ⁵ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.)

[0019]

Embedded image

(Y represents a divalent group of an aromatic hydrocarbon or a divalent group of a heterocyclic ring containing a nitrogen atom in the ring.)

[0021]

Embedded image

(Y represents an aromatic hydrocarbon divalent group or a heterocyclic divalent group containing a nitrogen atom in the ring.)

[0023]

Embedded image

(R ¹⁰ represents a hydrogen atom, a lower alkyl group, a carboxyl group, or an ester thereof, and Ar ¹ represents a substituted or unsubstituted aromatic hydrocarbon ring group.)

[0025]

Embedded image

(R ¹¹ represents a hydrogen atom, a lower alkyl group, a carboxyl group, or an ester thereof, and Ar ² represents a substituted or unsubstituted aromatic hydrocarbon ring group.)

The coupler residue represented by the above general formula is
More specifically, R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ ,
An alkyl group, an aryl group, for R ⁸ , R ⁹ or R ¹² ;
The aralkyl group and the heterocyclic group include lower alkyl groups having 1 to 4 carbon atoms, phenyl group, naphthyl group, anthryl group, pyrenyl group, benzyl group, furyl group, thienyl group,
Examples include a pyridyl group, a carbazolyl group, and a dibenzofuryl group. Examples of the substituent in the alkyl group include a halogen atom, and examples of the substituent in the aryl group, the aralkyl group, the heterocyclic group, and the styryl group of R ⁶ , R ⁷ , R ⁸ , and R ⁹ include a chlorine atom, a bromine atom, A halogen atom such as a fluorine atom or an iodine atom; a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group or a t-butyl group; an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group or a butoxy group; , Dimethylamino group, alkylamino group such as diethylamino group, nitro group, cyano group, trifluoromethyl group, hydroxy group,
Examples include a phenylamino group and a diphenylamino group.

Examples of the substituent on the polycyclic aromatic ring or hetero ring formed by bonding Z with a benzene ring include a halogen atom such as a chlorine atom, a bromine atom, a fluorine atom and an iodine atom, a methyl group, an ethyl group, Examples include lower alkyl groups such as propyl group, isopropyl group, butyl group and t-butyl group, alkoxy groups such as methoxy group, ethoxy group, propoxy group and butoxy group, nitro group, cyano group and the like. Examples of the lower alkyl group for R ¹⁰ and R ¹¹ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group, and an aromatic hydrocarbon ring group for Ar ¹ and Ar ² . Examples thereof include a phenyl group and a naphthyl group, and examples of the substituent include a halogen atom and a lower alkyl group.

The content ratio of the disazo pigment to the μ-oxo-gallium phthalocyanine dimer pigment used in the present invention is 0.01 ≦ μ-oxo-gallium phthalocyanine dimer pigment / (disazo pigment + μ-oxo-gallium phthalocyanine) by weight ratio. (Dimer pigment) ≦ 0.99 is preferable, and outside this range, the sensitizing effect of photosensitivity is reduced. Sensitization of photosensitivity is particularly attributable to the fact that the μ-oxo-gallium phthalocyanine dimer pigment has a sensitivity of 700 μm.
occurs in the long wavelength region of at least nm, the content ratio of the disazo pigment and the μ-oxo-gallium phthalocyanine dimer pigment is
A greater sensitizing effect is exhibited when 0.40 ≦ μ-oxo-gallium phthalocyanine dimer pigment / (disazo pigment + μ-oxo-gallium phthalocyanine dimer pigment) ≦ 0.99, which is particularly preferable.

Further, by simultaneously mixing and pulverizing the disazo pigment and the μ-oxo-gallium phthalocyanine dimer pigment with the application of mechanical energy, the above-mentioned sensitizing effect is remarkably improved. Although the reason for this is not clear, it is presumed that by performing pulverization or mixing by applying mechanical energy, a state in which interaction occurs easily between the pigments and the charge generation efficiency is improved.

The μ-oxo-gallium phthalocyanine dimer pigment used in the present invention has the formula

Embedded image A hydroxygallium phthalocyanine obtained by the method described in JP-A-1-221559 and JP-A-5-279951 in a water-immiscible, high-boiling organic solvent. Can be obtained.

Here, it is possible to obtain a μ-oxo-gallium phthalocyanine dimer pigment having various crystal forms depending on the kind of the high-boiling organic solvent. In particular, CuKα obtained when an amide-based solvent such as DMF is used is used. Angle in the X-ray diffraction spectrum by X-rays (2θ ±
0.2 °) 7.4 °, 9.9 °, 12.5 °, 12.
9 ゜, 16.1 ゜, 18.5 ゜, 21.9 ゜, 22.2
゜, 24.0 ゜, 25.1 ゜, 25.8 ゜ and 28.2
Those having a crystal transformation showing a diffraction peak in ゜ are excellent in photosensitivity and potential stability.

Specific examples of the disazo pigment represented by the general formula (I) used in the present invention include the following compounds. Among them, the following compounds (A) and (B) are particularly preferable. The compound represented has a high sensitivity in the visible region, and when used in combination with a μ-oxo-gallium phthalocyanine dimer pigment, has good coating liquid stability, enables good film formation, and significantly A great sensitizing effect.

[0034]

Embedded image

[0035]

Embedded image

Specific examples of the coupler forming the coupler residue of the disazo pigment represented by the general formula (I) are shown in Table 1 below.
-(1) to Table 16 exemplify.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6]

[0043]

[Table 7]

[0044]

[Table 8]

[0045]

[Table 9]

[0046]

[Table 10]

[0047]

[Table 11]

[0048]

[Table 12]

[0049]

[Table 13]

[0050]

[Table 14]

[0051]

[Table 15]

[0052]

[Table 16]

[0053]

[Table 17]

[0054]

[Table 18]

[0055]

[Table 19]

[0056]

[Table 20]

[0057]

[Table 21]

[0058]

[Table 22]

[0059]

[Table 23]

[0060]

[Table 24]

[0061]

[Table 25]

The charge transporting material used in the electrophotographic photoreceptor of the present invention includes, for example, oxazole derivatives, imidazole derivatives, triphenylamine derivatives,
And compounds represented by the following general formulas (1) to (19).

[0063]

Embedded image

(Wherein R ¹ is a methyl group, an ethyl group, 2-
Represents a hydroxyethyl group or a 2-chloroethyl group;
² represents a methyl group, an ethyl group, a benzyl group or a phenyl group; R ³ represents a hydrogen atom, a chlorine atom, a bromine atom,
Represents an alkyl group having 1 to 4, an alkoxyl group having 1 to 4 carbon atoms, a dialkylamino group or a nitro group. )

Compounds represented by the general formula (1) 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.

[0066]

Embedded image

(Wherein, Ar represents a naphthalene ring, anthracene ring, 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). Include, for example, 4-diethylaminostyryl-3-aldehyde-1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-aldehyde-1-benzyl-1
-Phenylhydrazone and the like.

[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, and R ² and R ³ may be the same or different;
Represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group, a chloroalkyl group or a substituted or unsubstituted aralkyl group, and R ² and R ³ are bonded to each other to form a nitrogen-containing heterocyclic ring. You may. 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. )

Compounds represented by the general formula (3) include, for example, 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane, 1,1-bis (4- Dibenzylaminophenyl) propane and 2,2′-dimethyl-4,4′-bis (diethylamino) -triphenylmethane.

[0071]

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.) A compound represented by the general formula (4) Is, for example, 9- (4-diethylaminostyryl) anthracene, 9-bromo-1
0- (4-diethylaminostyryl) anthracene and the like.

[0073]

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, Represents 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. Examples of the compound represented by the general formula (5) include 3-styryl-9-ethylcarbazole and 3- (4-methoxystyryl) -9-ethylcarbazole.

[0075]

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 naphthyl group. )

The compound represented by the general formula (6) includes, for example, 4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene,
-(4-diphenylaminostyryl) naphthalene, 1-
(4-Diethylaminostyryl) naphthalene and the like.

[0078]

Embedded image

Wherein n is an integer of 0 or 1, R ¹ is a hydrogen atom, an alkyl group or a substituted or unsubstituted phenyl group, Ar ¹ is a substituted or unsubstituted aryl group, and R ⁵ is A represents an alkyl group containing a substituted alkyl group or a substituted or unsubstituted aryl group, and A represents a 9-anthryl group, a substituted or unsubstituted carbazolyl group or

[0080]

Embedded image Wherein R ² is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or

[0081]

Embedded image

(Provided that R ³ and R ⁴ represent an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ³ and R ⁴ may be the same or different, and May be formed), and m is 0,
An integer of 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. ]

The compound represented by the general formula (7) includes, for example, 4′-diphenylamino-α-phenylstilbene, 4′-bis (methylphenyl) amino-α-phenylstilbene and the like.

[0084]

Embedded image

(Wherein, 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 represent a hydrogen atom, Represents a lower alkyl group, a lower alkoxy group or a halogen atom.)

The benzidine compound represented by the general formula (8) includes, for example, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl]-
4,4′-diamine, 3,3′-dimethyl-N, N,
N ', N'-tetrakis (4-methylphenyl)-
[1,1′-biphenyl] -4,4′-diamine and the like.

[0087]

Embedded image

(Wherein R ¹ , R ³ and R ⁴ represent a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom or a substituted Or an 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 are all hydrogen atoms 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. )

The biphenylamine compound represented by the general formula (9) includes, for example, 4'-methoxy-N, N-diphenyl- [1,1'-biphenyl] -4-amine,
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.

[0090]

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,
Represents a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, or a substituted or unsubstituted phenyl group, which may be the same or different. In addition, examples of the triarylamine compound represented by the general formula (10) include 1-laminopyrene and 1-di (p-tolylamino) pyrene.

A-CH = CH-Ar-CH = CH-A (11) [wherein, Ar represents a substituted or unsubstituted aromatic hydrocarbon group;

[0093]

Embedded image

(Where, Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ¹ and R ² are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). Examples of the diolefin aromatic compound represented by the general formula (11) include 1,4-bis (4-diphenylaminostyryl) benzene and 1,4-bis [4-
Di (p-tolyl) aminostyryl] benzene.

[0095]

Embedded image

(Wherein R ¹ is an alkyl group, a benzyl group,
Represents a phenyl group or a naphthyl group, R ² represents a hydrogen atom, 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; Represents an integer from 4 to 4, and n
Is 2 or more, R ² may be the same or different.
R ³ represents a hydrogen atom or a methoxy group. )

Compounds represented by the general formula (12) include, 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.

[0098]

Embedded image

(Wherein, 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. Examples of the compound represented by the general formula (13) include N-ethyl-3,6-tetrabenzylaminocarbazole.

[0100]

Embedded image

[Wherein R ¹ is a hydrogen atom, a halogen atom,
Cyano group, alkoxy group having 1 to 4 carbon atoms or 1 to carbon atoms
4 represents an alkyl group, wherein Ar is

[0102]

Embedded image

Wherein R ² represents an alkyl group having 1 to 4 carbon atoms, and R ³ represents a hydrogen atom, a halogen atom, and a carbon atom having 1 to 4 carbon atoms.
Represents an alkyl group, an alkoxy group having 1 to 4 carbon atoms or a dialkylamino group, wherein n is 1 or 2, and when n is 2, R ³ may be the same or different, and R ⁴ and R ⁵ are Represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted benzyl group. As the compound represented by the general formula (14), for example, 9-
(4-dimethylaminobenzylidene) fluorene, 3-
(9-Fluorenylidene) -9-ethylcarbazole and the like.

[0104]

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 dialkyl Amino group, alkyl group, alkoxy group, carboxy group or ester thereof, halogen atom, cyano group, aralkylamino group, N-alkyl-N-aralkylamino group,
Represents a group selected from the group consisting of an amino group, a nitro group and an acetylamino group. Examples of the compound represented by the general formula (15) include 1,2-bis (4-diethylaminostyryl) benzene and 1,2-bis (2,4-dimethoxystyryl) benzene.

[0106]

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). Include, for example, 1-phenyl-3- (4-diethylaminostyryl) -5- (4-
Diethylaminophenyl) pyrazoline, 1-phenyl-
3- (4-dimethylaminostyryl) -5- (4-dimethylaminophenyl) pyrazolin and the like.

[0108]

Embedded image

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

The compound represented by the general formula (17) includes, 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.

[0111]

Embedded image

(Wherein, X represents a hydrogen atom, a lower alkyl group or a halogen atom, R represents an alkyl group containing a substituted alkyl group, or a substituted or unsubstituted aryl group;
A represents a substituted amino group or a substituted or unsubstituted aryl group. )

As the compound represented by the general formula (18), for example, 2-N, N-diphenylamino-5- (N
-Ethylcarbazol-3-yl) -1,3,4-oxadiazole, 2- (4-diethylaminophenyl)-
5- (N-ethylcarbazol-3-yl) -1,3,3
4-oxadiazole and the like.

[0114]

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, n is 0 or 1, and m is 1 Or 2 and n = 0, m = 1,
Ar and R may form a ring together. ) General formula (1
Examples of the styrylpyrene compound represented by 9) include 1- (4-diphenylaminostyryl) pyrene,
-[4-di (p-tolyl) aminostyryl] pyrene and the like.

These charge transporting substances can be used alone or in combination of two or more. Among the above, in the present invention, the chargeability and light can be improved by using a charge transport material having an oxidation potential of +0.5 V (vs SCE) or more, and furthermore, a charge transport material represented by any of the general formulas (1) to (11). Excellent in sensitivity, which is preferable. The oxidation potential of the charge transporting material in the present invention is a half-wave potential in a generally known cyclic voltametery measurement. This is a value when a saturated calomel electrode (SCE) is used as a reference electrode.

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 ability to form a film 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, epoxy resin, melamine resin, urethane resin,
Examples include, but are not limited to, thermoplastic or thermosetting resins such as phenolic resins and alkyd resins.

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. A thin film of a metal such as aluminum, silver, gold, nickel, or a conductive material such as indium oxide or tin oxide, or a conductive powder such as carbon black, indium oxide, or tin oxide dispersed in a suitable resin to form a film Examples thereof include formed ones, paper subjected to a conductive treatment, and the like. The shape of the conductive support is not particularly limited, and a plate, a drum, or a belt is used as necessary.

Hereinafter, the present invention will be described with reference to FIGS. 1 to 4. Reference numeral 1 denotes a conductive support, and reference numeral 2 denotes a photoconductive layer according to the present invention. The electrophotographic photoreceptor of the present invention, as shown in FIGS.
The photoconductive layer may be of any form as long as it is a single layer type, and an undercoat layer 3 may be provided between the photoconductive layer 2 and the conductive support 1 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.

To prepare the electrophotographic photoreceptor of the present invention,
The disazo pigment and the μ-oxo-gallium phthalocyanine dimer pigment pigment were simultaneously mixed and pulverized by the above-mentioned method, and a charge transporting substance and a binder resin were added and mixed. It may be applied using a bead coating method or the like. 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 particularly preferably tetrahydrofuran and cyclohexanone in view of the sensitizing effect. Can be

In the electrophotographic photoreceptor of the present invention, the ratio of the charge generating substance to the binder resin is 0.01 to 10 parts by weight, preferably 0.1 to 10 parts by weight, based on 10 parts by weight of the binder resin. It is preferably in the range of parts by weight. When the amount of the disazo pigment is less than the above range, the sensitivity is lowered, and the residual potential is large. When the amount is more than the above range, the chargeability and the mechanical strength are reduced. The ratio of the charge transport material to the binder resin is such that the charge transport material is 1 to 10 parts by weight of the binder resin.
It is preferably in the range of 15 to 15 parts by weight. If the amount of the charge transporting substance is less than the above range, the sensitivity is lowered, and if it is more than the above range, the chargeability and the mechanical strength are deteriorated.

The thickness of the photoconductive layer of the present invention is 5 to 100 μm.
m, particularly preferably in the range of 10 to 50 μm. If it is thinner than 5 μm, there is no mechanical durability, and if it is thicker than 100 μm, the residual potential increases.

[0123]

Next, the present invention will be described in more detail by way of examples. Example 1 The following No. 1 was used as a charge generation material. After dispersing 5 parts by weight of the disazo pigment No. 1 and 5 parts by weight of the μ-oxo-gallium phthalocyanine dimer pigment together with 35 parts by weight of tetrahydrofuran in a ball mill for 5 days, the mixture is stirred and mixed. 10
0 parts by weight, 300 parts by weight of tetrahydrofuran, 80 parts by weight of 4-diethylaminobenzaldehyde-1-benzyl-1-phenylhydrazone represented by the general formula (12) as a charge transporting substance, silicone oil [KF-50 (Shin-Etsu Chemical Co., Ltd.) )] To a solution consisting of 0.1 parts by weight,
A coating solution for a photoconductive layer was prepared. The coating liquid for a photoconductive layer obtained in this manner is blade-coated on an aluminum plate [A1080 (manufactured by Sumitomo Light Metal Co., Ltd.)] having a thickness of 0.2 mm.
After drying at 130 ° C. for 20 minutes, a photoconductive layer having a thickness of 20 μm was formed. Thus, an electrophotographic photosensitive member of Example 1 was prepared. When the oxidation potential of the charge transporting substance used in Example 1 was measured by the above-described method, the oxidation potential was 0.50 V (vs. SC
E).

[0124]

Embedded image

Example 2 In Example 1, the process was repeated. 1 disazo pigment is
o. An electrophotographic photosensitive member of Example 2 was prepared in the same manner as in Example 1 except that the disazo pigment of Example 2 was changed.

[0126]

Embedded image

Embodiment 3 In the embodiment 1, in the case of 1 disazo pigment is
o. An electrophotographic photosensitive member of Example 3 was prepared in the same manner as in Example 1, except that the disazo pigment of Example 3 was changed.

[0128]

Embedded image

Embodiment 4 In the embodiment 1, in the case of Example 4 was carried out in the same manner as in Example 1 except that the input amount of the disazo pigment was changed to 0.04 parts by weight and the input amount of the μ-oxo-gallium phthalocyanine dimer pigment was changed to 0.04 parts by weight. Was prepared.

Fifth Embodiment In the first embodiment, in the case of Example 5 was repeated in the same manner as in Example 1 except that the input amount of the disazo pigment was changed to 0.05 parts by weight and the input amount of the μ-oxo-gallium phthalocyanine dimer pigment was changed to 0.05 parts by weight. Was prepared.

Embodiment 6 In the embodiment 1, no. The electrophotographic photosensitive of Example 6 was carried out in the same manner as in Example 1, except that the input amount of the disazo pigment was changed to 50 parts by weight and the input amount of the μ-oxo-gallium phthalocyanine dimer pigment was changed to 50 parts by weight. Created body.

Embodiment 7 In the embodiment 1, in the case of The electrophotographic photosensitive of Example 7 was carried out in the same manner as in Example 1, except that the input amount of the disazo pigment was changed to 75 parts by weight and the input amount of the μ-oxo-gallium phthalocyanine dimer pigment was changed to 75 parts by weight. Created body.

Example 8 An electrophotographic photosensitive member of Example 8 was prepared in the same manner as in Example 1, except that the amount of the charge transport material was changed to 5 parts by weight.

Example 9 An electrophotographic photosensitive member of Example 9 was prepared in the same manner as in Example 1, except that the amount of the charge transporting substance was changed to 10 parts by weight.

Example 10 Example 10 was repeated in the same manner as in Example 1 except that the amount of the charge transport material was changed to 150 parts by weight.
Was prepared.

Example 11 Example 11 was repeated in the same manner as in Example 1 except that the amount of the charge transport material was changed to 200 parts by weight.
Was prepared.

Comparative Example 1 As a charge generating substance, 10 parts by weight of the disazo pigment of Example 1 were dispersed together with 70 parts by weight of tetrahydrofuran in a ball mill for 5 days, and 100 parts by weight of a Z-type polycarbonate resin having a molecular weight of 60,000, 300 parts by weight of tetrahydrofuran, and 80 parts by weight of the charge transport material used in Example Part, silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)]
In addition to the solution consisting of 1 part by weight, a coating solution for a photoconductive layer was prepared. The coating liquid for a photoconductive 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 As a charge generating substance, 10 parts by weight of the μ-oxo-gallium phthalocyanine dimer pigment of Example 1 was dispersed together with 70 parts by weight of tetrahydrofuran in a ball mill for 5 days, and this was dispersed in a Z-type polycarbonate resin having a molecular weight of 60,000.
0 parts by weight, 300 parts by weight of tetrahydrofuran, Example 1
Was added to a solution consisting of 80 parts by weight of the charge transporting substance used in the above and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)] to prepare a coating solution for a photoconductive layer. The coating liquid for a photoconductive layer thus obtained was formed into a film in the same manner as in Example 1, and an electrophotographic photosensitive member of Comparative Example 2 was prepared.

Example 12 As a charge generating substance, 5 parts by weight of the disazo pigment of Example 1 and 5 parts by weight of the μ-oxo-gallium phthalocyanine dimer pigment of Example 1 were dispersed together with 70 parts by weight of tetrahydrofuran in a ball mill for 5 days, subjected to simultaneous pulverization and mixing, and then stirred and mixed. 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 charge transporting substance used in Example 1 as a charge transporting substance, silicone oil [KF
-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)], and a coating solution for a photoconductive layer was prepared. The coating liquid for a photoconductive layer thus obtained is applied to a 0.2 mm-thick aluminum plate [A1080 (manufactured by Sumitomo Light Metal Co., Ltd.)] with a blade, dried at 150 ° C. for 20 minutes, and dried with a light having a thickness of 20 μm. An electrophotographic photosensitive member of Example 12 was formed by forming a conductive layer.

The electrophotographic photosensitive member obtained as described above
Of EPA-8 under 25 ° C / 50% RH environment
Dynamic method using 100 (manufactured by Kawaguchi Electric Works)
Was measured. First, it is charged for 10 seconds with the applied voltage + 6KV
After dark decay for 20 seconds
30 seconds with colored light at a surface illuminance of 10 lux
Exposure was performed. Similarly, charge and dark decay are performed,
Illuminance 10μW / cm^Two780nm monochromatic light source
Exposure was also performed. The charging potential is the surface potential V2 2 seconds after charging.
(V), the sensitivity is that the surface potential after exposure is the surface potential just before exposure.
Exposure E1 / 2 (lux.
sec [white light]) and E1 / 2 (μJ / cm ^Two[monochromatic
Light]), the residual potential is the surface after 30 seconds exposure with each light source.
The potential V30 (V) was measured. Table 17 shows the results.

[0141]

[Table 26]

As is clear from Table 17, the electrophotographic photosensitive member of the present invention has high sensitivity to visible light and near-infrared light. Disazo pigments and μ-
When the oxo-gallium phthalocyanine dimer pigment contains 0.1 to 10 parts by weight based on 10 parts by weight of the binder resin and 1 to 15 parts by weight of the charge transporting substance based on 10 parts by weight of the binder resin, the sensitivity, It shows that the charge potential, the residual potential and the like are excellent.

Examples 13 to 33 Electrophotographs of Examples 13 to 33 were carried out 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 18 below. A photoreceptor was made.

[0144]

[Table 27]

Examples 13 to 3 obtained as described above
3 and the electrostatic characteristics of the electrophotographic photosensitive member of Example 1 were set at 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 so as to be 0 lux. The charging potential is the saturated surface potential Vm (V) for 10 seconds of charging.
And the sensitivity is that the surface potential after exposure is 2 times the surface potential immediately before exposure.
Exposure E1 / 2 (lux · sec)
[White light]) was measured. Table 19 shows the results. FIG. 5 shows the plotted results of the saturated surface potential Vm.

[0146]

[Table 28]

Further, Embodiments 1, 16, and 2
With respect to the electrophotographic photoreceptor of No. 4,
This was repeated 000 times, and the stability of the electrostatic characteristics was evaluated. Table 20 shows the results.

[0148]

[Table 29]

As is apparent from FIG. 5, when the oxidation potential of the charge transport material is +0.5 V (vs SCE) or more,
Particularly high charging potential is obtained. Further, as shown in Table 19, in Examples 13 to 27 using the charge transport materials represented by the general formulas (1) to (11), the chargeability was good,
Also, the light sensitivity is good. Further, as shown in Table 20, the electrophotographic photoreceptor of the present invention has excellent charge stability upon repeated use, and uses a charge transport material represented by the general formula (3). The electrophotographic photoreceptor of Example 16 is particularly excellent in terms of charging stability during repeated use.

Examples 34 to 39 In the same manner as in Example 1, the charge generation material No. The amounts of the disazo pigment and the μ-oxo-gallium phthalocyanine dimer pigment of No. 1 were 9 parts by weight and 1 part by weight, respectively.
Parts by weight, 6 parts by weight and 4 parts by weight, 4 parts by weight and 6 parts by weight, 2 parts by weight and 8 parts by weight, 1 part by weight and 9 parts by weight,
The electrophotographic photosensitive members of Examples 34 to 39 were prepared in the same manner as in Example 1 except that the amounts were changed to 0.1 parts by weight and 9.9 parts by weight.

The electrostatic characteristics of the electrophotographic photosensitive member obtained as described above were measured at 25 ° C./50% RH under EPA-8.
100 using (Kawaguchi Denki Seisakusho), in a dynamic manner, Examples 2 to 12 and similarly charged, performs dark decay, the surface illuminance 10 .mu.W / monochromatic light sensitivity due to 780nm monochromatic light source of cm ² E1 / 2 ( μJ / cm ² [monochromatic light]) was evaluated. FIG. 6 shows the results together with the results of Example 1 and Comparative Example 2. As is apparent from FIG. 6, the content ratio of the disazo pigment to the μ-oxo-gallium phthalocyanine dimer pigment is 0.40 ≦ μ-oxo-gallium phthalocyanine dimer pigment / (disazo pigment + μ-oxo-).
In the case where (gallium phthalocyanine dimer pigment) ≦ 0.99, a large sensitizing effect is exhibited.

Comparative Example 3 As the charge generating substance, 5 parts by weight of 1 disazo pigment and 5 parts by weight of the μ-oxo-gallium phthalocyanine dimer pigment pigment of Example 1 were dispersed together with 70 parts by weight of tetrahydrofuran in a ball mill for 5 days, and further diluted with 420 parts by weight of tetrahydrofuran to form a coating for the charge generation layer. A working solution was prepared. The coating liquid for a charge generation layer thus obtained was coated on an aluminum plate with a blade and dried at 100 ° C. for 10 minutes to form a 0.3 μm-thick charge generation layer. 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 transport material, and 0.1 part by weight of silicone oil [KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.)] It was dissolved in 300 parts by weight of dichloromethane to prepare a coating solution 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 a thickness of 20 μm.
Was formed, and a laminated electrophotographic photosensitive member of Comparative Example 3 was formed.

The thus obtained multilayer electrophotographic photosensitive member of Comparative Example 3 and the single-layer electrophotographic photosensitive member of Example 1 were measured for spectral sensitivity by a static method. The applied voltage was adjusted so as to be -600 V for the laminated electrophotographic photosensitive member of Comparative Example 3 and +600 V for the electrophotographic photosensitive member of Example 1, and thereafter, the monochromator (N
900 nm to 400 nm (20 nm
Irradiates monochromatic light that has been dispersed in steps, and changes the sensitivity (V · c) from the exposure amount required for the surface potential immediately before exposure to become half.
m ² / μJ). FIG. 7 shows the result. FIG.
As is clear from the above, the electrophotographic photoreceptor of Example 1 according to the present invention has higher sensitivity over a short wavelength range to a long wavelength range than the laminated electrophotographic photoreceptor of Comparative Example 3.

[0154]

The electrophotographic photoreceptor of the present invention has high sensitivity from the visible region to the near-infrared region, has excellent stability of electrostatic characteristics upon repeated use, and does not cause a decrease in image density or background fouling. An electrophotographic photoreceptor having a long life and high reliability.
In particular, the content ratio of the disazo pigment to the μ-oxo-gallium phthalocyanine dimer pigment is 0.40 by weight.
≦ μ-oxo-gallium phthalocyanine dimer pigment /
By setting (disazo pigment + μ-oxo-gallium phthalocyanine dimer pigment) ≦ 0.99, the sensitivity is further improved, and the oxidation potential as the charge transporting substance is increased to +0.
By using a charge transporting substance of 5 V (vs SCE) or more, an electrophotographic photoreceptor having more excellent electrostatic characteristics and sensitivity can be obtained. Further, by using a mixed pigment obtained by simultaneously pulverizing and mixing a disazo pigment and a μ-oxo-gallium phthalocyanine dimer pigment, an electrophotographic photoreceptor having even higher sensitivity can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of an electrophotographic photosensitive member according to the present invention.

FIG. 2 is a cross-sectional view schematically showing another example of the electrophotographic photosensitive member according to the present invention.

FIG. 3 is a cross-sectional view schematically showing another example of the electrophotographic photosensitive member according to the present invention.

FIG. 4 is a cross-sectional view schematically showing another example of the electrophotographic photosensitive member according to the present invention.

FIG. 5 is a diagram showing a relationship between an oxidation potential (vs. SCE) of a charge transporting substance and a charging potential in the electrophotographic photoreceptor of the present invention.

FIG. 6 is a view showing the relationship between the content ratio of a disazo pigment and a μ-oxo-gallium phthalocyanine dimer pigment in the electrophotographic photoreceptor of the present invention and sensitivity.

FIG. 7 is a diagram showing spectral sensitivities of the electrophotographic photosensitive member of the present invention and a comparative electrophotographic photosensitive member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 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 Theme coat ゛ (Reference) G03G 5/06 322 G03G 5/06 322 324 324B 367 367 371 371

Claims (19)

[Claims] 1. A photoconductive layer is formed on a conductive support.
In the electrophotographic photoreceptor, the photoconductive layer has the following general formula:
At least one disazo pigment represented by (I),
Oxo-gallium phthalocyanine dimer pigment, charge transport
That it consists of a single layer containing
An electrophotographic photosensitive member characterized by the following. Embedded image[However, in the above general formula (I), A and B are the following general formulas:
The coupler residues represented by (II) to (VIII) are shown. Embedded image｛However, in the above general formula (II), X¹, Y¹And Z are each
Represents the following: X ¹: -OH, -NHCOCH_Three,
Or -NHSO_TwoCH_Three. Y¹: -CON (R^Two)
(R^Three), -CONNH = C (R⁶) (R⁷), -CON
HN (R⁸) (R⁹), -CONHCONH (R¹²),water
Element atom, -COOH, -COOCH_Three, -COOC
₆H_FiveOr a benzimidazolyl group. (R^Two, R^ThreeIs hydrogen field
A substituted or unsubstituted alkyl group, a substituted or unsubstituted
A substituted aryl group or a substituted or unsubstituted heterocyclic group
And R^Two, R^ThreeForms a ring with the nitrogen atom attached to them
It may be formed. R⁶, R⁷Is a hydrogen atom, substituted or unsubstituted
Substituted alkyl group, substituted or unsubstituted aralkyl
Group, substituted or unsubstituted aryl group, substituted or unsubstituted
A substituted styryl group, a substituted or unsubstituted heterocyclic group
And R⁶, R⁷Represents a ring with the carbon atoms attached to them
It may be formed. R⁸, R⁹Is a hydrogen atom, substituted or unsubstituted
Substituted alkyl group, substituted or unsubstituted aralkyl
Group, substituted or unsubstituted aryl group, substituted or unsubstituted
A substituted styryl group, a substituted or unsubstituted heterocyclic group
And R⁸, R⁹May form a 5- or 6-membered ring
In this case, the 5- or 6-membered ring is a fused aromatic ring.
You may have. R¹²Is a substituted or unsubstituted alkyl
Group, substituted or unsubstituted aryl group, substituted or unsubstituted
It represents a substituted heterocyclic group. ) Z: bonded to a benzene ring
Naphthalene ring, anthracene ring, carbazole ring, ben
Zocarbazole ring, dibenzocarbazole ring, dibenzo
Furan ring, benzonaphthofuran ring, and dibenzothiophene
Form a polycyclic aromatic ring or hetero ring selected from
Residues required for These rings may have substituents
No. ｝ (3)(R^FourIs a hydrogen atom, a substituted or unsubstituted alkyl group,
Or a substituted or unsubstituted aryl group. )(R^FiveIs a hydrogen atom, a substituted or unsubstituted alkyl group,
Or a substituted or unsubstituted aryl group. )(Y is a divalent group of an aromatic hydrocarbon or a nitrogen atom in the ring
Represents a divalent group of a heterocyclic ring. )(Y is a divalent group of an aromatic hydrocarbon or a nitrogen atom in the ring
Represents a divalent group of a heterocyclic ring. )(R^TenRepresents a hydrogen atom, a lower alkyl group, a carboxyl group,
Or an ester thereof, and Ar¹Is substituted or unsubstituted
Is an aromatic hydrocarbon ring group. )(R¹¹Represents a hydrogen atom, a lower alkyl group, a carboxyl group,
Or an ester thereof, and Ar^TwoIs substituted or unsubstituted
Is an aromatic hydrocarbon ring group. )] 2. The content ratio of the disazo pigment to the μ-oxo-gallium phthalocyanine dimer pigment is 0.40 ≦ μ-oxo-gallium phthalocyanine dimer pigment / (disazo pigment + μ-oxo-gallium phthalocyanine dimer pigment) by weight ratio. 2. The electrophotographic photoreceptor according to claim 1, wherein satisfies 0.99. 3. The disazo pigment of the following formula (A) or (B)
3. The electrophotographic photoreceptor according to claim 1, which is a compound represented by the formula: Embedded image Embedded image 4. The method according to claim 1, wherein the disazo pigment and the μ-oxo-gallium phthalocyanine dimer pigment are contained in an amount of 0.01 to 10 parts by weight based on 10 parts by weight of the binder resin. Electrophotographic photoreceptor. 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 charge transport material has an oxidation potential of +0.5 V.
2. The electrophotographic photoreceptor according to claim 1, which is a compound of (vs SCE) or higher. 7. An oxidation potential of +0.5 V (vs SCE)
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (1). 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;
³ is a hydrogen atom, a bromine atom, 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. ) 8. An oxidation potential of +0.5 V (vs SCE)
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (2). Embedded image (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. An oxidation potential of +0.5 V (vs SCE)
The electrophotographic photoreceptor according to claim 6, wherein the charge transporting material contains at least one compound selected from the following formula (3). Embedded image (In the formula, R ¹ represents an alkyl group, a substituted or unsubstituted phenyl group, or a heterocyclic group of 1 to 11 carbon atoms, R ^2,
R ³ may be the same or different each represents a hydrogen atom, an alkyl group, a hydroxyalkyl group, chloroalkyl group, or a substituted or unsubstituted aralkyl group having 1 to 4 carbon atoms, 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. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following general formula (4). Embedded image (Wherein, R represents a hydrogen atom or a halogen atom;
Represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, or carbazolyl group. ) 11. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (5). Embedded image (Wherein, R ¹ represents a lower alkyl group, a substituted or unsubstituted phenyl group, or a benzyl group, R ² represents a hydrogen atom,
It represents 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, and n represents an integer of 1 or 2. ) 12. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (6): Embedded image (Wherein R ¹ is a hydrogen atom, an alkyl group, an alkoxy group,
Or a halogen atom, R ² and R ³ represent an alkyl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted aryl group, and R ⁴ represents a hydrogen atom, a lower alkyl group, or a substituted or unsubstituted Ar represents a phenyl group, and Ar represents a substituted or unsubstituted phenyl group or a naphthyl group. ) 13. An oxidation potential of +0.5 V (vs. SC
The electrophotographic photoreceptor according to claim 6, wherein at least one compound selected from the following general formula (7) is contained as E) or more charge transport materials. Embedded image [In the formula, n is an integer of 0 or 1, R ¹ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted phenyl group;
r 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, A represents a 9-anthryl group,
A substituted or unsubstituted carbazolyl group, or Wherein R ² is a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or (Wherein, R ³ and R ⁴ represents an alkyl group, a substituted or unsubstituted aralkyl group or a substituted or unsubstituted aryl group, R ³ and R ⁴ may be the same or different, R ⁴
May form a ring), and m is 0, 1, 2, or 3
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. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (8): Embedded image (Wherein, 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 ,
R ³ may be the same or different and represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom. ) 15. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (9): Embedded image (Wherein R ¹ , R ³ and R ⁴ are a hydrogen atom, an amino group, an alkoxy group, a thioalkoxy group, an aryloxy group, a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted Is an aryl group of R
² represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or a halogen atom. Where R ¹ , R ² ,
R ³ and R ⁴ exclude the case where all are hydrogen atoms. Also,
k, l, m and n are integers of ¹ , ² , 3 or 4, and when each is an integer of 2, 3 or 4, R ¹ , R ² , R ³ and R ⁴ may be the same or different. Is also good. ) 16. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (10): 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,
Represents a substituted or unsubstituted phenyl group, which may be the same or different. ) 17. An oxidation potential of +0.5 V (vs. SC
7. The electrophotographic photoreceptor according to claim 6, wherein the charge transport material contains at least one compound selected from the following formula (11). A-CH = CH-Ar-CH = CH-A (11) wherein Ar represents a substituted or unsubstituted aromatic hydrocarbon group, and A represents (However, Ar ′ represents a substituted or unsubstituted aromatic hydrocarbon group, and R ¹ and R ² are a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). ] 18. The electrophotographic photoreceptor according to claim 1, further comprising a mixed pigment obtained by simultaneously pulverizing and mixing a disazo pigment and a μ-oxo-gallium phthalocyanine dimer pigment. 19. The μ-oxo-gallium phthalocyanine dimer pigment has a Bragg angle (2θ ± 0.2 °) of 7.4 ° in X-ray diffraction spectrum by CuKα ray,
9.9 ゜, 12.5 ゜, 12.9 ゜, 16.1 ゜, 1
8.5 ゜, 21.9 ゜, 22.2 ゜, 24.0 ゜, 2
2. The electrophotographic photoreceptor according to claim 1, wherein the electrophotographic photoreceptor has a crystal modification showing diffraction peaks at 5.1, 25.8, and 28.2.