JPH07301930A - Electrophotographic photoreceptor, process cartridge having the electrophotographic photoreceptor, and electrophotographic apparatus - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity and having stable and excellent potential characteristics even after repeated use, a process cartridge having the electrophotographic photoreceptor, and An object is to provide an electrophotographic apparatus. The present invention provides an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer is an imide derivative,
An electrophotographic photoreceptor containing an azo pigment having a homophthalic acid derivative or a benzophenone derivative as a central skeleton, a process cartridge having the electrophotographic photoreceptor, and an electrophotographic apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer containing an azo pigment having a specific structure. The present invention also relates to a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member using an organic photoconductive material has advantages such as extremely high productivity and relatively low cost, and in addition, a dye or pigment to be used is selected. This has the advantage that the wavelength range having sensitivity can be freely controlled, and has been extensively studied so far. In particular, the function of stacking a charge generation layer containing a charge generation substance such as an organic photoconductive dye or pigment and a charge transport layer containing a charge transport substance such as a photoconductive polymer or a low molecular weight organic photoconductive substance. With the development of the electrophotographic photoreceptor having the separation type photosensitive layer, the sensitivity and durability, which have been the drawback of the electrophotographic photoreceptor using the conventional organic photoconductive material, have been remarkably improved.

Among the organic photoconductive substances, many azo pigments have excellent photoconductivity, and it is relatively easy to obtain pigments having various characteristics depending on how to combine an amine component and a coupler component. Therefore, many azo pigments have hitherto been disclosed, for example, in JP-A-60-46561, JP-A-60-131539, and JP-A-62-29506.
No. 2, JP-A-1-252966, and JP-A-4-96068.

[0004]

However, with the recent demand for higher image quality and higher durability, an electrophotographic photosensitive member having higher sensitivity and more excellent electrophotographic characteristics during repeated use. Is being considered.

An object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity.

Another object of the present invention is to provide an electrophotographic photosensitive member which has stable and excellent potential characteristics even after repeated use.

Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member as described above.

[0008]

That is, the present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer being at least selected from the group consisting of the following formulas (1) to (5). It is an electrophotographic photoreceptor containing an azo pigment represented by one formula.

[0009]

[Outside 6] (In the formula, Ar ₁ , Ar ₂ and Ar ₃ are the same or different and represent a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic heterocycle, and Cp ₁ , Cp ₂ and Cp ₃ are The same or different, it represents a coupler residue having a phenolic hydroxyl group.)

[0010]

[Outside 7] (In the formula, Ar ₄ and Ar ₅ are the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic heterocycle, and A ₁ represents a substituted or unsubstituted aromatic carbon ring in the formula. The residue necessary to form a substituted aromatic hydrocarbon ring and the residue necessary to form a substituted or unsubstituted aromatic heterocycle with a carbon atom in the formula are shown.
Cp ₄ , Cp ₅ and Cp ₆ are the same or different and each represents a coupler residue having a phenolic hydroxyl group. )

[0011]

[Outside 8] (In the formula, R ₁ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, Ar ₆ and Ar ₇ are the same or different, and a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic hydrocarbon ring; Represents an aromatic heterocycle, wherein A ₂ is a residue necessary for forming a substituted or unsubstituted aromatic hydrocarbon ring with a carbon atom in the formula, and a substituted or unsubstituted aromatic heterocycle with a carbon atom in the formula (Cp ₇ , Cp ₈ and Cp ₉ are the same or different and each represents a residue of a coupler having a phenolic hydroxyl group.)

[0012]

[Outside 9] (In the formula, R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, and Ar ₈ is the same or different and is a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. Represents a ring, and A ₃ and A ₄ are the same or different, and are substituted or unsubstituted with the carbon atom in the formula and the residue necessary for forming a substituted or unsubstituted aromatic hydrocarbon ring with the carbon atom in the formula. The residues necessary for forming a substituted aromatic heterocycle are shown as Cp ₁₀ and Cp ₁₁
And Cp ₁₂ are the same or different and each represents a coupler residue having a phenolic hydroxyl group. )

[0013]

[Outside 10] (In the formula, R ₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, and Ar ₉ , Ar ₁₀ and Ar ₁₁ are the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic hydrocarbon ring. Represents an unsubstituted aromatic heterocycle,
Cp ₁₃ , Cp ₁₄ and Cp ₁₅ are the same or different and represent a coupler residue having a phenolic hydroxyl group, and m, n and p are the same or different and represent 0 and a positive integer,
Not all of m, n and p show 0 at the same time. The present invention also provides a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

In the above formulas (1) to (5), Ar _{1 to} A
r ₁₁ are the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic heterocycle, and examples of the aromatic hydrocarbon ring include a benzene ring and a naphthalene ring. Examples of the ring include a pyridine ring and a thiophene ring. Also, Ar _{1 to} Ar
_{As the} substituent which ₁₁ has, an alkyl group such as methyl, ethyl and propyl; an alkoxy group such as methoxy, ethoxy and propoxy; a halogen atom such as fluorine, chlorine, bromine and iodine; a cyano group; and trifluoromethyl And other halomethyl groups and the like. In the present invention,
Ar _{1 to} Ar ₆ and Ar _{8 to} Ar ₁₁ are preferably a benzene ring, and Ar ₇ is preferably a benzene ring, a naphthalene ring or a pyridine ring.

Further, in the formulas (1) to (5), Cp _{1 to} Cp ₁₅ are the same or different and represent a coupler residue having a phenolic hydroxyl group. The coupler residue means a diazo component in obtaining a disazo pigment. And a group corresponding to a part of the coupler bonded to the azo group by the coupling reaction of the coupler, and preferably bonded to the azo group at the position ortho to the phenolic hydroxyl group. Cp _{1 and} Cp ₂ may be any as long as they are coupler residues having a phenolic hydroxyl group, and are represented by the following formulas (6) to (1)
It is preferably a coupler residue represented by 1).

[0016]

[Outside 11]

[0017]

[Outside 12]

Equations (6), (9), (10) and (11)
X _{1 to} X ₄ therein are necessary for condensing with a benzene ring to form a polycyclic aromatic hydrocarbon ring such as a naphthalene ring and anthracene ring or a heterocycle such as a carbazole ring, a benzcarbazole ring and a dibenzocarbazole ring. Indicates a residue.

Y ₁ in the formula (8) represents an arylene group or a divalent heterocyclic group containing a nitrogen atom in the ring. Specifically, o-phenylene, o-naphthylene, perinaphthylene,
1,2-anthrylene, 3,4-pyrazoldiyl,
2,3-pyridinediyl, 4,5-pyridinediyl,
Examples include groups such as 6,7-indazolediyl and 6,7-quinolinediyl.

R ₄ , R ₅ and R in the formulas (6) and (10)
₈ and R ₉ represent a hydrogen atom, an alkyl group, an aryl group, an aralkyl group and a heterocyclic group, and R ₄ and R ₅ and R
₈ and R ₉ represent a residue which is bonded to each other to form a cyclic amino group.

R ₆ in the formula (7) represents an alkyl group, an aryl group, an aralkyl group or a heterocyclic group.

R ₇ in the formula (9) represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group or a heterocyclic group.

R ₁₀ and R ₁₁ in the formula (11) are hydrogen atoms,
It represents an alkyl group, an aryl group, an aralkyl group, a heterocyclic group, and a residue forming a ring group by being bonded to each other.

The above alkyl group is a group such as methyl, ethyl and propyl, the aryl group is a group such as phenyl, naphthyl and anthryl, the aralkyl group is a group such as benzyl and phenethyl, and the heterocyclic group is pyridyl and thienyl. And groups such as thiazolyl, carbazolyl, benzimidazolyl and benzothiazolyl. Examples of the cyclic amino group include groups such as pyrrolyl, indolyl, indolinyl, carbazolyl, imidazolyl, benzimidazolyl, pyrazolyl, phenothiazinyl and phenoxysazinyl. Further, examples of the ring group formed by combining R ₁₀ and R ₁₁ include groups such as fluorenidene, xanthenylidene, antronylidene, and hydroindenylidene.

Further, X _{1 to} X ₄ , Y ₁ , R _{4 to} R ₁₁
May have a substituent, and the substituent which may have is an alkyl group such as methyl, ethyl and propyl; an alkoxy group such as methoxy, ethoxy and propoxy; a halogen atom such as fluorine, chlorine, bromine and iodine. An acyl group such as acetyl and benzoyl; an alkylamino group such as dimethylamino and diethylamino; a phenylcarbamoyl; a nitro group; a cyano group; and a halomethyl group such as trifluoromethyl.

Further, q in the formula (6) represents 0 or 1, and Z ₁ and Z _{2 in} the formulas (6) and (9) represent an oxygen atom or a sulfur atom.

In the present invention, Cp _{1 to} Cp ₁₅ are represented by a formula selected from the group consisting of formulas (6), (9), (10) and (11), and X _{1 to} X ₄ in the formula are: When the coupler residue is a coupler residue which is condensed with a benzene ring to form a benzocarbazole ring, the azo pigment can be preferably used also as a charge generating substance for a semiconductor laser because its sensitivity region extends to the near infrared region. .

In the formulas (2), (3) and (4), A _{1 to} A ₄ are the same or different and are required to form a substituted or unsubstituted aromatic hydrocarbon ring with the carbon atom in the formula. And a residue necessary for forming a substituted or unsubstituted aromatic heterocycle with the carbon atom in the formula. Examples of the formed aromatic hydrocarbon ring include a benzene ring and a naphthalene ring, and examples of the formed aromatic heterocycle include a pyridine ring and a thiophene ring. Also, A ₁
To A ₄ may have a substituent such as an alkyl group such as methyl, ethyl and propyl; an alkoxy group such as methoxy, ethoxy and propoxy; a halogen atom such as fluorine, chlorine, bromine and iodine; a nitro group; a cyano group And halomethyl groups such as trifluoromethyl and the like. In the present invention, it is preferable that A _{1 to} A ₄ are residues necessary for forming a benzene ring.

In formulas (3) to (5), R _{1 to} R ₃ represent a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, and examples of the alkyl group include a methyl group, an ethyl group and a propyl group. To be The substituents that R _{1 to} R ₃ may have include alkyl groups such as methyl, ethyl and propyl; alkoxy such as methoxy, ethoxy and propoxy; halogen atoms such as fluorine, chlorine, bromine and iodine; Acyl groups such as acetyl and benzoyl; alkylamino such as dimethylamino and diethylamino;
Phenylcarbamoyl; nitro group; cyano group; and halomethyl group such as trifluoromethyl. In the present invention, R ₁ and R ₂ are preferably a hydrogen atom, a methyl group or a cyano group, and R ₃ is preferably a hydrogen atom, a methyl group, an ethyl group or a cyano group.

In the formula (5), m, n and p represent 0 and a positive integer, but m, n and p are not all 0 at the same time. That is, the azo pigment represented by the formula (5) has at least one carbonyl group in its molecule. In the present invention, it is preferable that m is 0, n is 1 and p is 1 or 2.

The azo pigments represented by the formulas (3) and (4) have isomers capable of imparting the same electrophotographic properties, but in the present application, the formulas (3) and The isomer is also expressed by (4). That is, equation (3) is

[0032]

[Outside 13] , And equation (4) is

[0033]

[Outside 14] as well as

[0034]

[Outside 15] Will also be shown.

Preferred examples of the azo pigments represented by the formulas (1) to (5) are listed below, but the azo pigments used in the present invention are not limited thereto. Incidentally, the exemplified pigments first show the basic type, and the changing parts thereof are Ar _{1 to} Ar ₁₁ , Cp _{1 to} Cp ₁₅ , A _{1 to} A ₄ ,
It is represented by indicating R _{1 to} R ₃ , m, n and p.

[0036]

[Outside 16]

[0037]

[Outside 17]

[0038]

[Outside 18]

[0039]

[Outside 19]

[0040]

[Outside 20]

[0041]

[Outside 21]

[0042]

[Outside 22]

[0043]

[Outside 23]

[0044]

[Outside 24]

[0045]

[Outside 25]

[0046]

[Outside 26]

[0047]

[Outside 27]

[0048]

[Outside 28]

[0049]

[Outside 29]

[0050]

[Outside 30]

[0051]

[Outside 31]

[0052]

[Outside 32]

[0053]

[Outside 33]

[0054]

[Outside 34]

[0055]

[Outside 35]

[0056]

[Outside 36]

[0057]

[Outside 37]

[0058]

[Outside 38]

[0059]

[Outside 39]

[0060]

[Outside 40]

[0061]

[Outside 41]

[0062]

[Outside 42]

[0063]

[Outside 43]

[0064]

[Outside 44]

[0065]

[Outside 45]

[0066]

[Outside 46]

[0067]

[Outside 47]

[0068]

[Outside 48]

[0069]

[Outside 49]

[0070]

[Outside 50]

[0071]

[Outside 51]

[0072]

[Outside 52]

[0073]

[Outside 53]

[0074]

[Outside 54]

[0075]

[Outside 55]

[0076]

[Outside 56]

[0077]

[Outside 57]

[0078]

[Outside 58]

[0079]

[Outside 59]

[0080]

[Outside 60]

[0081]

[Outside 61]

[0082]

[Outside 62]

[0083]

[Outside 63]

[0084]

[Outside 64]

[0085]

[Outside 65]

The azo pigment used in the present invention is hexazolated from the corresponding triamine by a conventional method, and the obtained hexazonium salt is coupled with the corresponding coupler in the aqueous system in the presence of an alkali, or the hexazonium salt is converted into a borofluoride salt. Coupling with a corresponding coupler in the presence of a base such as sodium acetate, triethylamine and N-methylmorpholine in an organic solvent such as N, N-dimethylformamide or dimethylsulfoxide after conversion to a sodium chloride, zinc chloride double salt or the like. Can be easily synthesized by. Azo pigments having different coupler residues in one molecule can be synthesized by sequentially coupling couplers one by one. As the sequential coupling method, a method of adjusting the number of couplers with respect to the number of azo groups, a method of utilizing the difference in the reaction rate of the couplers, and a part of the azo groups are temporarily protected with an acetyl group or the like. Methods and the like.

Synthesis Example 1 (Synthesis of Pigment of Pigment Example 1-1) 150 ml of water and 20 ml of concentrated hydrochloric acid in a 300 ml beaker.
(0.23 mol) and the following triamine compound

[0088]

[Outside 66] 11.85 g (0.032 mol) was added, the mixture was cooled to 0 ° C., and 7.0 g (0.102) of sodium nitrite was added to this solution.
(Mol) was dissolved in 10 ml of water, added dropwise over 10 minutes while maintaining the liquid temperature at 5 ° C., stirred for 15 minutes, and then filtered with carbon. Sodium borofluoride 1 into the obtained filtrate
A solution prepared by dissolving 5.8 g (0.144 mol) in 120 ml of water was added dropwise with stirring. The precipitated borofluoride salt was collected by filtration, washed with cold water, washed with acetonitrile, and dried under reduced pressure at room temperature. The yield was 15.79 g, and the yield was 74%.

Next, 500 ml of dimethylformamide was placed in an 11 beaker, and 10.97 g (0.
042 mol)

[0090]

[Outside 67] Was dissolved and the liquid temperature was cooled to 5 ° C., 9.34 g (0.014 mol) of the borofluoride salt obtained above was dissolved, and then 4.7 g (0.046 mol) of triethylamine was added dropwise over 5 minutes. did. After stirring for 2 hours, the precipitated pigment was collected by filtration, washed with dimethylformamide 4 times and water 3 times, and then freeze-dried. The yield was 13.06 g, and the yield was 78%. The results of elemental analysis are shown below.

[0091]

[Table 1]

Synthesis Example 2 (Synthesis of Pigment 2-2) As a triamine compound, the following formula is used.

[0093]

[Outside 68] Using 11.76 g (0.032 mol) of the compound represented by the formula: 2-hydroxy-3-naphthoic acid-
12.50 g (0.042 mol) of 2'-chloroanilide
The azo pigment of Pigment Example 2-2 was synthesized in the same manner as in Synthesis Example 1 except that was used. The yield of borofluoride salt is 13.50 g.
And the yield was 65%, and the yield of the azo pigment was 14.50.
The yield was 80% in g. The results of elemental analysis are shown below.

[0094]

[Table 2]

Synthesis Example 3 (Synthesis of Pigment of Pigment Example 3-1) As a triamine compound, the following formula is used.

[0096]

[Outside 69] The azo pigment of Pigment Example 3-1 was synthesized in the same manner as in Synthesis Example 1 except that 12.56 g (0.032 mol) of the compound shown in 1 was used. The yield of borofluoride salt is 19.96g,
The yield was 92%, and the yield of azo pigment was 14.64 g.
The yield was 90%. The results of elemental analysis are shown below.

[0097]

[Table 3]

Synthesis Example 4 (Synthesis of Pigment of Pigment Example 4-1) A triamine compound represented by the following formula

[0099]

[Outside 70] The azo pigment of Pigment Example 4-1 was synthesized in the same manner as in Synthesis Example 2 except that 12.56 g (0.032 mol) of the compound shown in 1 was used. The yield of borofluoride salt is 19.90g,
The yield was 55%, the azo pigment yield was 11.5 g,
The yield was 62%. The results of elemental analysis are shown below.

[0100]

[Table 4]

Synthesis Example 5 (Synthesis of Pigment of Pigment Example 5-1) A triamine compound represented by the following formula

[0102]

[Outside 71] The azo pigment of Pigment Example 5-1 was synthesized in the same manner as in Synthesis Example 1 except that 12.24 g (0.032 mol) of the compound represented by The yield of borofluoride salt is 12.49g,
The yield was 58%, and the yield of azo pigment was 15.34 g.
The yield was 90%. The results of elemental analysis are shown below.

[0103]

[Table 5]

The form of the photosensitive layer of the electrophotographic photosensitive member of the present invention may be any known form, but a layer containing the azo pigment of the present invention as a charge generating substance is used as a charge generating layer, and A function-separated type photosensitive layer having a charge-transporting layer containing a charge-transporting substance laminated thereon is particularly preferable.

For the charge generation layer, the azo pigment of the present invention is vacuum-deposited on a conductive support, or a solution prepared by dispersing the azo pigment in a binder resin using a suitable solvent is applied on the conductive support. It can be formed by applying by a known method and drying. The film thickness is preferably 5 μm or less, and particularly preferably 0.1 to 1 μm.

The above-mentioned binder resin is selected from various insulating resins or organic photoconductive polymers, and includes polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulose resin, acrylic resin and polyurethane. Is preferred. These resins may have a substituent, and the substituent is preferably a halogen atom, an alkyl group, an alkoxy group, a nitro group, a trifluoromethyl group, a cyano group or the like. The content of the binder resin is preferably 80% by weight or less based on the total weight of the charge generation layer,
In particular, it is preferably 40% by weight or less.

Further, the solvent is preferably selected from those which dissolve the above-mentioned resin but do not dissolve the charge transport layer and the undercoat layer described later. Specifically, ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as cyclohexanone and methyl ethyl ketone; amides such as N, N-dimethylformamide; esters such as methyl acetate and ethyl acetate; toluene, xylene and Aromatic hydrocarbon compounds such as monochlorobenzene; alcohols such as methanol, ethanol and 2-propanol; and aliphatic hydrocarbon compounds such as chloroform and methylene chloride.

The charge transport layer is laminated on or under the charge generation layer and has a function of receiving charge carriers from the charge generation layer and transporting them in the presence of an electric field. The charge transport layer can be formed by applying a solution in which a charge transport substance is dissolved in a solvent together with an appropriate binder resin as necessary, and drying. The film thickness is preferably 5 to 40 μm, and particularly preferably 15 to 30 μm.

The charge transport material is roughly classified into an electron transport material and a hole transport material. Examples of the electron transport material include 2,
Examples include electron-withdrawing substances such as 4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil and tetracyanoquinodimethane, and polymers obtained by polymerizing these electron-withdrawing substances. As the hole-transporting substance, polycyclic aromatic compounds such as pyrene and anthracene;
Heterocyclic compounds such as carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole and triazole; p-diethylaminobenzaldehyde-N, N-
Hydrazone compounds such as diphenylhydrazone and N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole; α-phenyl-4′-N, N-diphenylaminostilbene, 5- [4- (di-p- Styryl-based compounds such as tolylamino) benzylidene] -5H-dibenzo [a, d] cycloheptene; benzidine-based compounds;
Triarylmethane compounds; triphenylamine compounds; or polymers having groups derived from these compounds in the main chain or side chains (for example, poly-N-vinylcarbazole and polyvinylanthracene). In addition to these organic charge transport materials, inorganic materials such as selenium, selenium-tellurium, amorphous silicon and cadmium sulfide can also be used. These charge transport materials may be used alone or in combination of two or more.

When the charge transport material has no film forming property, a suitable binder resin can be used. Specifically, insulating resin such as acrylic resin, polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, polyacrylamide, polyamide and chlorinated rubber, or organic photoconductive material such as poly-N-vinylcarbazole and polyvinylanthracene. And the like. The content of the binder resin is preferably 20 to 90% by weight or less, particularly 40 to 70% by weight, based on the total weight of the charge transport layer.
Is preferred.

Another specific example of the present invention is an electrophotographic photoreceptor having a photosensitive layer containing the azo pigment of the present invention and the above-mentioned charge transporting substance in the same layer.
In this case, a charge-transfer complex composed of poly-N-vinylcarbazole and trinitrofluorenone may be used as the charge-transporting substance. This electrophotographic photoreceptor can be prepared by dispersing and dissolving the azo pigment and the charge transporting substance in a suitable binder resin solution, coating the solution on a conductive support, and drying the solution. The content of such binder resin is 20 to 90 relative to the total weight of the photosensitive layer.
%, Especially 40 to 70% by weight
Is preferred. The film thickness is preferably 5 to 40 μm, and particularly preferably 15 to 30 μm.

In any of the electrophotographic photoreceptors, two or more kinds of the azo pigments of the present invention may be combined or used in combination with a known charge generating substance, if necessary.

The material of the conductive support used in the present invention is, for example, aluminum, aluminum alloy, copper,
Zinc, stainless steel, vanadium, molybdenum, chrome,
Examples include titanium, nickel, indium, gold, platinum, and the like. In addition, plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) and conductive particles (for example, carbon black and silver particles) formed by coating these metals or alloys by a vacuum deposition method may be used. The above-mentioned plastic, a support coated on a metal or an alloy, or a support obtained by impregnating plastic or paper with conductive particles can be used together with an appropriate binder resin.
The shape may be a drum shape, a sheet shape, a belt shape, or the like, but a shape most suitable for the electrophotographic apparatus to be applied is preferable.

In the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support and the photosensitive layer. The thickness of the undercoat layer is preferably 5 μm or less, and particularly preferably 0.1 to 3 μm. Examples of the material of the undercoat layer include casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide and the like.

Further, in the present invention, for the purpose of protecting the photosensitive layer from external mechanical and chemical adverse effects, etc., a resin layer as a protective layer, or a resin layer containing conductive particles or a charge transport substance is used. Can also be provided on the photosensitive layer.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines but also in laser beam printers, C
RT printer, LED printer, liquid crystal printer,
It can be widely used in electrophotographic application fields such as laser plate making and facsimile.

FIG. 1 shows a schematic structure of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoconductor 1 rotates during the rotation process.
The peripheral surface of the primary charging means 3 is uniformly charged with a predetermined positive or negative potential, and then image exposure light 4 from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoconductor 1.

The electrostatic latent image thus formed is then developed by the developing means 5.
The toner-developed image is developed by the toner, and the developed toner-developed image is transferred to the transfer material 7 which is fed between the photosensitive member 1 and the transfer unit 6 in synchronization with the rotation of the photosensitive member 1 from a sheet feeding unit (not shown). The images are sequentially transferred by the transfer means 6.

The transfer material 7 which has received the image transfer is separated from the surface of the photoconductor and introduced into the image fixing means 8 to undergo the image fixing, so that it is printed out as a copy out of the apparatus.

The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning means 9 to remove the residual toner after transfer, and further the pre-exposure light 10 from the pre-exposure means (not shown).
After being subjected to static elimination processing by, it is repeatedly used for image formation. If the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not always necessary.

In the present invention, among the constituent elements such as the electrophotographic photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 described above, a plurality of components are integrally combined to form a process cartridge, The process cartridge may be detachably attached to the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, a process in which at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoconductor 1 to form a cartridge, and which can be attached to and detached from the apparatus body by using a guide unit such as a rail 12 of the apparatus body. Cartridge 11
Can be

Further, when the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal,
Laser beam scanning and LE performed according to this signal
The light is emitted by driving the D array, driving the liquid crystal shutter array, and the like.

On the other hand, when used as a printer for a facsimile, the image exposure light 4 becomes exposure light for printing the received data. FIG. 2 is a block diagram showing an example of this case.

The controller 14 controls the image reading section 13 and the printer 22. The entire controller 14 is controlled by the CPU 20. The read data from the image reading unit 13 is transmitted to the partner station through the transmission circuit 16. The data received from the partner station is sent to the printer 22 through the receiving circuit 15. Predetermined image data is stored in the image memory. The printer controller 21 controls the printer 22. 17 is a telephone.

The image received from the line 18 (image information from the remote terminal connected through the line) is demodulated by the receiving circuit 15, and then the image information is decoded by the CPU 20 and sequentially stored in the image memory 19. Is stored. When the image of at least one page is stored in the image memory 19, the image of that page is recorded. CPU20
Reads one page of image information from the image memory 19 and sends the decoded one page of image information to the printer controller 21. Upon receiving the image information of one page from the CPU 20, the printer controller 21 controls the printer 22 to record the image information of the page. The CPU 20 is receiving the next page during recording by the printer 22.

In this way, the image is received and recorded. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0128]

【Example】

Example 1 A solution prepared by dissolving 5 g of methoxymethylated nylon (number average molecular weight 32,000) and 10 g of alcohol-soluble copolymer nylon (number average molecular weight 29,000) in 95 g of methanol was coated on an aluminum substrate with a wire bar and dried. By doing so, an undercoat layer having a film thickness of 1 μm was formed.

Next, 5 g of the pigment of Pigment Example 1-1 was added to a solution of 2 g of polyvinyl butyral (butyralization degree: 63% or more, number average polymerization degree: 2,000) dissolved in 95 g of cyclohexanone, and a sand mill was used for 20 hours. Dispersed.
This dispersion was applied onto the undercoat layer with a wire bar and dried to form a charge generation layer having a thickness of 0.2 μm.

Then, 5 g of a hydrazone compound represented by the following formula

[0131]

[Outside 72] And polymethylmethacrylate (number average molecular weight 100,0
A solution of 5 g of 00) dissolved in 40 g of chlorobenzene was applied on the charge generation layer with a wire bar and dried to form a charge transport layer having a thickness of 20 μm.

The obtained electrophotographic photosensitive member was subjected to -5 by using an electrostatic copying paper test device (SP-428, manufactured by Kawaguchi Electric Co., Ltd.).
The charging characteristics were evaluated by negatively charging with a corona discharge of kV, holding in the dark for 1 second, and then exposing with halogen light having an illuminance of 10 lux. As the charging characteristics, the surface potential V ₀ immediately after charging and the surface potential after being left in a dark place for 1 second are 1 /
The exposure dose required to attenuate to 2, that is, the sensitivity (E _1/2 ) was measured. The results are shown in Table 1.

Examples 2 to 45 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the azo pigments shown in Table 1 were used instead of the azo pigment of Pigment Example 1-1. The results are shown in Table 1.

[0134]

[Table 6] Comparative Examples 1 to 6 Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Example 1 except that the following comparative pigments A to F were used in place of the azo pigments of Pigment Example 1-1. The results are shown in Table 2.

[0135]

[Outside 73]

[0136]

[Outside 74]

[0137]

[Table 7]

Example 46 An electrophotographic copying machine provided with the electrophotographic photosensitive member prepared in Example 2 was equipped with a -6.5 kV corona charger, an exposure optical system, a developing device, a transfer charger, a discharge exposure optical system and a cleaner. I stuck it on the cylinder.

The initial dark portion potential V _D and the light portion potential _VL are set to around -700 V and -200 V, respectively, and 5.00
The durability was evaluated by repeating the use 0 times and measuring the variation ΔV _D of the dark potential and the variation ΔV _L of the bright potential at the initial stage and after the repeated use. The results are shown in Table 3.
In addition, the negative symbol in the variation amount of the potential represents that the absolute value of the potential has decreased, and the positive symbol represents that the absolute value of the potential has increased.

Examples 47 to 70 Except that the electrophotographic photosensitive member prepared in Example 2 was replaced by the electrophotographic photosensitive member prepared in the same manner as in Example 1 except that the azo pigments listed in Table 3 were used. Durability was evaluated in the same manner as in Example 46. The results are shown in Table 3.

[0141]

[Table 8]

Comparative Examples 7 to 12 Example 4 was repeated except that the electrophotographic photosensitive members prepared in Comparative Examples 1 to 6 were used instead of the electrophotographic photosensitive members prepared in Example 2.
Durability was evaluated in the same manner as in No. 6. The results are shown in Table 4.

[0143]

[Table 9]

Example 71 An undercoat layer of polyvinyl alcohol (number average molecular weight: 22,000) having a thickness of 0.5 μm was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film.

Onto this undercoat layer, Pigment 5 of Pigment Example 1-4
95 g of cyclohexanone was added to a solution of 2 g of butyral resin (degree of butyralization: 63 mol%, number average degree of polymerization: 2,000) dissolved in 95 g of cyclohexanone. A charge generation layer having a thickness of 0.2 μm was formed.

Then, 5 g of a styryl compound represented by the following formula

[0147]

[Outside 75] And polycarbonate (weight average molecular weight 55,000) 5
A solution of 40 g of tetrahydrofuran in 40 g is applied onto the charge generation layer and dried to give a film thickness of 2
A 0 μm charge transport layer was formed.

The charging characteristics and durability of the obtained electrophotographic photosensitive member were evaluated in the same manner as in Examples 1 and 46. The results are shown in Table 5.

Examples 72 to 75 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 71 except that the azo pigments shown in Table 5 were used in place of the azo pigments of Pigment Examples 1-4. The results are shown in Table 5.

[0150]

[Table 10]

Examples 76 to 80 Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Examples 3, 11, 19, 25 and 34 except that the charge generation layer and the charge transport layer were formed in the reverse order. However, the polarity of the primary charging was positive. The results are shown in Table 6.

[0152]

[Table 11]

Example 81 A charge generation layer was formed in the same manner as in Example 3.

Next, 5 g of 2,4,7-trinitro-9-fluorenone and polycarbonate (weight average molecular weight 3
A solution of 5 g of 50,000) dissolved in 50 g of tetrahydrofuran was applied on the charge generation layer with a wire bar and dried to form a charge transport layer having a thickness of 20 μm. The obtained electrophotographic photosensitive member was evaluated in the same manner as in Example 1. However, the polarity of charging was positive. The result is 7th
Shown in the table.

Examples 82 to 85 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 81 except that the charge generation layer was formed in the same manner as in Examples 12, 19, 25 and 34. However, the thickness of the charge transport layer in Example 85 was set to 18 μm. The results are shown in Table 7.

[0156]

[Table 12]

Example 86 A solution obtained by adding 0.5 g of the azo pigment of Pigment Example 1-2 to 9.5 g of cyclohexanone was dispersed with a paint shaker for 5 hours. The charge transport material 5 used in Example 1 was added to this dispersion.
g and polycarbonate (weight average molecular weight 80,000)
A solution prepared by dissolving 5 g in 40 g of tetrahydrofuran was added, and the mixture was further shaken for 1 hour. The obtained solution was applied onto an aluminum substrate with a wire bar and dried to form a photosensitive layer having a film thickness of 20 μm. The obtained electrophotographic photosensitive member was evaluated in the same manner as in Example 1. However, the polarity of charging was positive. The results are shown in Table 8.

Examples 86 to 90 An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 86 except that the azo pigments shown in Table 8 were used in place of the azo pigments of Pigment Example 1-2. However, the thickness of the charge transport layer in Example 90 was set to 16 μm. The results are shown in Table 8.

[0159]

[Table 13]

[0160]

As described above, according to the present invention, an electrophotographic photoreceptor having high sensitivity and stable and excellent potential characteristics even after repeated use, and a process cartridge having the electrophotographic photoreceptor. Also, an electrophotographic apparatus can be provided.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

FIG. 2 is a diagram showing an example of a block diagram of a facsimile having the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 1 Electrophotographic Photoreceptor of the Present Invention 2 Axis 3 Primary Charging Means 4 Image Exposure Light 5 Developing Means 6 Transfer Means 7 Transfer Material 8 Image Fixing Means 9 Cleaning Means 10 Pre-Exposure Light 11 Process Cartridge 12 Rail 13 Image Reading Part 14 Controller 15 Receiver circuit 16 Transmitter circuit 17 Telephone 18 Line 19 Image memory 20 CPU 21 Printer controller 22 Printer

Claims (13)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer is represented by the following formulas (1) to (5):
An electrophotographic photoreceptor containing an azo pigment represented by at least one formula selected from the group consisting of: [Outer 1] (In the formula, Ar ₁ , Ar ₂ and Ar ₃ are the same or different and represent a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic heterocycle, and Cp ₁ , Cp ₂ and Cp ₃ are The same or different, it represents a coupler residue having a phenolic hydroxyl group.) [External 2] (In the formula, Ar ₄ and Ar ₅ are the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic heterocycle, and A ₁ represents a substituted or unsubstituted aromatic carbon ring in the formula. The residue necessary to form a substituted aromatic hydrocarbon ring and the residue necessary to form a substituted or unsubstituted aromatic heterocycle with a carbon atom in the formula are shown.
Cp ₄ , Cp ₅ and Cp ₆ are the same or different and each represents a coupler residue having a phenolic hydroxyl group. ) [Outside 3] (In the formula, R ₁ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, Ar ₆ and Ar ₇ are the same or different, and a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic hydrocarbon ring; Represents an aromatic heterocycle, wherein A ₂ is a residue necessary for forming a substituted or unsubstituted aromatic hydrocarbon ring with a carbon atom in the formula, and a substituted or unsubstituted aromatic heterocycle with a carbon atom in the formula The residues necessary for forming a ring are shown, and Cp ₇ , Cp ₈ and Cp ₉ are the same or different and each represents a coupler residue having a phenolic hydroxyl group. (In the formula, R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, and Ar ₈ is the same or different and is a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. Represents a ring, and A ₃ and A ₄ are the same or different and are substituted or unsubstituted with a residue necessary for forming a substituted or unsubstituted aromatic hydrocarbon ring with a carbon atom in the formula and a carbon atom in the formula. The residues necessary for forming a substituted aromatic heterocycle are shown as Cp ₁₀ and Cp ₁₁
And Cp ₁₂ are the same or different and each represents a coupler residue having a phenolic hydroxyl group. ) [Outer 5] (In the formula, R ₃ represents a hydrogen atom, a substituted or unsubstituted alkyl group and a cyano group, and Ar ₉ , Ar ₁₀ and Ar ₁₁ are the same or different and each represents a substituted or unsubstituted aromatic hydrocarbon ring and a substituted or unsubstituted aromatic hydrocarbon ring. Represents an unsubstituted aromatic heterocycle,
Cp ₁₃ , Cp ₁₄ and Cp ₁₅ are the same or different and represent a coupler residue having a phenolic hydroxyl group, and m, n and p are the same or different and represent 0 and a positive integer,
Not all of m, n and p show 0 at the same time. ) 2. The electrophotographic photosensitive member according to claim 1, wherein the azo pigment is represented by the formula (1). 3. The electrophotographic photosensitive member according to claim 1, wherein the azo pigment is represented by formula (2). 4. The electrophotographic photosensitive member according to claim 1, wherein the azo pigment is represented by formula (3). 5. The electrophotographic photosensitive member according to claim 1, wherein the azo pigment is represented by formula (4). 6. The electrophotographic photosensitive member according to claim 1, wherein the azo pigment is represented by formula (5). 7. The electrophotographic photosensitive member according to claim _1, wherein Ar _{1 to} Ar ₃ are benzene rings. 8. The electrophotographic photosensitive material according to claim 1, wherein said Ar ₄ and Ar ₅ are benzene rings, and said A ₁ is a residue necessary for forming a benzene ring together with the carbon atom in the formula. body. 9. The R ₁ is a hydrogen atom, a methyl group or a cyano group, the Ar ₆ is a benzene ring, and the A is
The electrophotographic photosensitive member according to claim 1 or 4, wherein r ₇ is a benzene ring, a naphthalene ring or a pyridine ring, and A ₂ is a residue necessary for forming a benzene ring with the carbon atom in the formula. 10. The R ₂ is a hydrogen atom, a methyl group or a cyano group, the Ar ₈ is a benzene ring, and the A ₃ and A ₄ together with the carbon atom in the formula are necessary to form a benzene ring. 6. The electrophotographic photosensitive member according to claim 1, which is a residual group. 11. The R ₃ is a hydrogen atom, a methyl group, an ethyl group or a cyano group, the Ar _{9 to} Ar ₁₁ are benzene rings, the m is 0, the n is 1, and 7. The electrophotographic photosensitive member according to claim 1, wherein p is 1 or 2. 12. The electrophotographic photosensitive member according to claim 1, and at least one unit selected from the group consisting of a charging unit, a developing unit, and a cleaning unit are integrally supported, and can be attached to and detached from the main body of the electrophotographic apparatus. Process cartridge characterized by being. 13. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.