JP3264618B2 - Electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to novel using Trypto ant phosphorus derived material, e.g. electrostatic copying machines, laser beam printers, plain paper facsimile apparatus electrophotographic photoreceptor used in an image forming apparatus such as a It is about.

[0002]

2. Description of the Related Art In the above-described image forming apparatus, a charge generating agent which generates charges by light irradiation, a charge transporting agent which transfers generated charges, and a binder resin constituting a layer in which these substances are dispersed are used. So-called organic photoreceptor (OP
C) is widely used. Organic photoreceptors are roughly divided into those having a single-layer type photosensitive layer containing a charge generating agent and a charge transporting agent in the same layer, a charge generating layer containing a charge generating agent, and a charge transporting agent. There is a type provided with a laminated type photosensitive layer in which a charge transport layer containing an agent is laminated, and among these, a photoreceptor provided with a laminated type photosensitive layer is generally used. In addition, in the above-mentioned laminated photosensitive layer, a charge transport layer having a thickness larger than that of the charge generation layer is generally disposed outside the photosensitive member from the viewpoint of mechanical strength.

The charge transporting agents used in these photoreceptors include those having a hole-transporting property and those having an electron-transporting property. Many of the carriers having high carrier mobility that can provide high sensitivity have a hole transporting property. For this reason, the organic photoreceptors currently in practical use are of a negative charge type in the case of a stacked type in which a charge transport layer is provided outside the above-described photoreceptor.

[0004] However, the photoreceptor having the above-described negatively-charged laminated photoreceptor layer needs to be charged by negative corona discharge, which generates a large amount of ozone. Deterioration becomes a problem. In order to solve such a problem, an electron transporting agent having a high carrier mobility has been developed and studied. For example, JP-A-1-206349 discloses that a compound having a diphenoquinone structure is used as an electron transporting agent. It has been proposed to.

[0005]

However, diphenoquinones generally have poor compatibility with a binder resin and are not uniformly dispersed, so that the hopping distance of electrons is long, and electron transfer is particularly difficult to occur in a low electric field. For this reason, diphenoquinones themselves have high carrier mobility, but when they are used in a photoreceptor as an electron transporting agent, their properties are not sufficiently exhibited, and the residual potential of the photoreceptor increases, Light sensitivity was insufficient.

Further, as described above, most of the organic photoconductors which have been put into practical use at present have a laminated type photosensitive layer. Has a number of advantages in that it has a simple structure and is easy to manufacture, suppresses the occurrence of coating defects, and improves optical characteristics.
In addition, a photoreceptor having such a single-layer type photosensitive layer can be used in combination with an electron transporting agent and a hole transporting agent as a charge transporting agent so that one photoreceptor has a positive charging type and a negative charging type. Although it can be used for both, and there is a possibility that the application range of the photoreceptor may be expanded, the diphenoquinones have a problem of inhibiting the transport of electrons and holes due to the interaction with the hole transport agent, and therefore, such A photoreceptor having a single-layer type photosensitive layer has not been widely put to practical use.

An object of the present invention is to solve the technical problems above, it is to provide an electrophotographic photoreceptor with high sensitivity in comparison with the traditional.

[0008]

In order to solve the above-mentioned problems, an electrophotographic photosensitive member of the present invention comprises an electrophotographic photosensitive member on a conductive substrate.
As a transport agent, the general formula (1):

[0009]

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[In the formula, R ^1A and R ^1B are the same or different and each represent a hydrogen atom, an alkyl group, an acyl group, an alkoxycarbonyl group, or a cyano group. However, R ^1A and R ^1B are not hydrogen atoms at the same time. R ^2A , R ^2B , R ^2C , R ^2D , R
^3A , R ^3B , R ^3C and R ^3D are the same or different and represent a hydrogen atom or an alkyl group which may have a substituent. A photosensitive layer containing a tryptoanthrin derivative represented by
It is characterized in that the digits.

[0011] written belt script Ant phosphorus derivatives, one of the carbonyl groups of the tryptophanase Ant phosphorus ring, the general formula
(a):

[0012]

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Wherein R ^1A and R ^1B are the same as above. Which has excellent electron-accepting properties due to the action of the above group, exhibits higher electron-transporting ability than conventional diphenoquinone-based compounds, and matches with a charge generating agent (pigment). And the injection of electrons from the charge generating agent is performed smoothly. In addition, the above tryptoanthrin derivative has good solubility in a solvent and compatibility with a binder resin due to the action of the above group,
Since it is uniformly dispersed in the photosensitive layer, the electron hopping distance is short, and the electron transport property is particularly excellent in a low electric field. Therefore, the above-mentioned tryptoanthrin derivative is excellent in the function as an electron transporting agent of an electrophotographic photosensitive member.

Therefore, the electrophotographic photosensitive member of the present invention has high sensitivity.

That is, the photosensitive layer containing the above-described tryptoanthrin derivative has excellent electron-transporting properties at a low electric field, reduces the rate of recombination of electrons and holes in the layer, and reduces the apparent charge generation efficiency. As a result, the sensitivity of the photoconductor is improved. Also, the residual potential of the photoreceptor is reduced, and the stability and durability when repeatedly exposed are improved. In particular, tryptoantrine derivatives inhibit the transport of electrons and holes, do not cause interaction with hole transport agents,
Particularly when used in a single-layer type photosensitive layer containing a hole transporting agent in the same layer, a photosensitive member having higher sensitivity can be constituted.

When an electron-accepting compound having an oxidation-reduction potential of -0.8 to -1.4 V is used in combination with the above-mentioned tryptoanthrin derivative, the electron-accepting compound extracts electrons from the charge generating agent. Since it functions to transfer to the tryptoanthrin derivative, the injection of electrons from the charge generating agent to the tryptoanthrin derivative is further smoothed, and the sensitivity of the photoreceptor is further improved.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below. First, a trypto anthrin derivative used as an electron transport agent in the present invention will be described. Examples of the alkyl group corresponding to R ^1A and R ^1B in the general formula (1) include methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, hexyl and the like. Examples of the acyl group include acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, pivaloyl, benzoyl, 2-naphthoyl, and the like.
o-tolu oil and the like. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl, normal propoxycarbonyl, isopropoxycarbonyl, tertiary butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl and the like.

Further, R ^2A , R ^2B , R ^2C , R ^2D , R ^3A , R
Examples of the alkyl group corresponding to ^3B , R ^3C and R ^3D include the same alkyl groups having 1 to 6 carbon atoms as described above. Examples of the substituent which may be substituted on the alkyl group include fluorine and chlorine. Halogen atoms such as phenyl, tolyl, xylyl, biphenylyl, o-terphenyl, naphthyl, anthryl and phenanthryl; methoxy, ethoxy, normal propoxy,
Examples thereof include an alkoxy group such as isopropoxy, tertiary butoxy, pentyloxy, and hexyloxy, and the aforementioned acyl group.

[0019] To synthesize tryptophanase ant phosphorus derivative of the general formula (1), first, as shown in the following reaction scheme, the isatoic anhydride or its derivative represented by the general formula (1a),
Isatin represented by the general formula (1b) or a derivative thereof,
Reaction in a suitable solvent, for example in the presence of a base,
A tryptoanthrin represented by the general formula (1c) or a derivative thereof is synthesized.

[0020]

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Next, this tryptoanthrin or its derivative (1c) is converted into a compound of the general formula (1d) in a suitable solvent, for example, in the presence of sodium hydride:

[0022]

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[0023] is reacted with phosphorous ester derivative represented by represented by the general formula (1) belt script Ant phosphorus derivatives are synthesized. Examples of the solvent used in the previous reaction include toluene and pyridine also having a base function. When toluene or the like having no base function is used as the solvent, 1,4-diazabicyclo [2 , 2,2] octane and the like. The reaction is performed at a reflux temperature for about 2 to 6 hours.

The solvent used in the subsequent reaction includes, for example, tetrahydrofuran, dimethylformamide and the like, and the reaction is carried out at 0 to 25 ° C. for about 1 to 24 hours. In addition, a tryptoanthrin derivative in which both R ^1A and R ^1B in the general formula (1) are cyano groups can be prepared by reacting the above tryptoanthrin or its derivative (1c) in an appropriate solvent, for example, in the presence of sodium ethoxide. Below, it is synthesized by reacting with malononitrile.

Examples of the solvent used in the reaction include ethanol, tetrahydrofuran, pyridine and the like, and the reaction is carried out at 25 to 100 ° C. for about 2 to 5 hours. Specific compounds of the above Quito script Ant phosphorus derivatives, but are not limited to for example, the formula (1-1) to (1-3)
And the compound represented by

[0026]

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Next, the electrophotographic photosensitive member of the present invention will be described. The electrophotographic photosensitive member of the present invention, a conductive substrate, one or two or more of the represented by the general formula (1) belt script Ant phosphorus derivative which was a photosensitive layer comprising as an electron transporting agent is there. The photosensitive layer includes a single-layer type and a laminated type as described above.

The single-layer type photosensitive layer is, in a binder resin, the electron transport agent der belt script Ant phosphorus derivative (1), and a hole transport material, those obtained by containing a charge generating agent, The photoreceptor provided with the single-layer type photosensitive layer can be used for both positive and negative charging types, but is preferably used for the positive charging type which does not require the use of the negative corona discharge described above. The laminated photosensitive layer includes a charge generating layer containing a charge generating agent and an electron transporting agent.
Belt script consists of a charge transport layer ant containing phosphorus derivative (1), the photosensitive layer comprising the photosensitive member of the laminate type is the stacking order of both layers may be configured in any of the charging type positive and negative, also similarly For this reason, it is preferable to adopt a positive charge type configuration in which the charge transport layer is disposed on the outermost layer.

The structure of the present invention can be applied to both the single-layer type and the stacked type, but it can be used for both positive and negative charging types as described above, and the structure is simple and easy to manufacture. That film defects can be suppressed from occurring as in the case where a layer is applied over the previously formed layer,
The single-layer type is preferable because the interface between the layers is small and the optical characteristics can be improved.

In a photoreceptor having a positively charged single-layer type photosensitive layer, electrons (-) released from the charge generating agent in the exposure step are smoothly injected into the tryptoanthrin derivative (1). The positive and negative charges (+) which are transported to the surface of the photosensitive layer by transfer between the trypto anthrin derivatives (1) and previously charged on the surface of the photosensitive layer are canceled out. On the other hand, the holes (+) are injected into the hole transporting agent, transported to the conductive substrate by transfer between the hole transporting agents, and canceled by the negative charge (-) applied to the conductive substrate in advance.

During this time, since the tryptoanthrin derivative (1) and the hole transport agent do not interact with each other as described above, both the hole (+) and the electron (−) are trapped in the middle. Without being transported efficiently and promptly,
As a result, it is considered that the sensitivity of the photoconductor is improved.
Further, in the photoreceptor of the present invention, the oxidation-reduction potential together with the tryptoanthrin derivative (1) is-as described above.
It is preferable to use an electron accepting compound having a voltage of 0.8 to -1.4 V in combination.

The above-mentioned electron-accepting compound has a LUMO
Since the energy level of [Lowest Unoccupied Molecular Orbital] is lower than that of the charge generating agent, when the electron-hole pair is generated in the charge generating agent by light irradiation, electrons are generated from the charge generating agent. It works to pull out. Therefore, the rate of disappearance of electrons and holes due to recombination in the charge generating agent is reduced, and the charge generation efficiency is improved.

The electron-accepting compound also functions to efficiently transfer electrons extracted from the charge generating agent to a tryptoanthrin derivative as an electron transporting agent. For this reason, in the combination system of the two, the injection and transport of electrons from the charge generating agent are performed smoothly, and the sensitivity of the photoconductor is further improved. The oxidation-reduction potential of the electron-accepting compound is limited to the above range for the following reason.

That is, an electron-accepting compound having an oxidation-reduction potential lower than -0.8 V lowers electrons which move while repeating trap-detrap to a level at which trapping cannot be performed, and causes electron transport due to carrier trapping. As a result, the sensitivity of the photoconductor is reduced.
Conversely, in the case of an electron-accepting compound having a redox potential higher than -1.4 V, the energy level of the LUMO is higher than that of the charge generating agent, and electrons are charged when an electron-hole pair is generated. Since it does not function to pull out from the generator, it does not lead to an improvement in the charge generation efficiency, and also lowers the sensitivity of the photoreceptor.

The oxidation-reduction potential of the electron-accepting compound is preferably within a range of -0.85 to -1.00 V in consideration of the sensitivity of the photoreceptor. The measurement of the oxidation-reduction potential is performed by, for example, using the following materials and performing three-electrode cyclic voltammetry. Electrode: working electrode (glassy carbon electrode), counter electrode (platinum electrode) Reference electrode: silver nitrate electrode (0.1 mol / liter AgNO)
₃ -acetonitrile solution) Measurement solution Electrolyte: tetra-n-butylammonium perchlorate
1 mol Measurement substance: Electron-accepting compound 0.001 mol Solvent: CH ₂ Cl ₂ 1 liter The above materials are mixed to prepare a measurement solution.

Then, as shown in FIG. 1, the index voltage (V)
Seeking relationship between current (.mu.A) and, E ₁ and E shown in FIG.
_2, and the oxidation-reduction potential is determined by the following formula. Redox potential = (E ₁ + E ₂ ) / 2 (V) Such an electron accepting compound has an electron accepting property,
There is no particular limitation as long as the compound has a redox potential in the range of -0.8 to -1.4 V. For example, benzoquinone compounds; naphthoquinone compounds; anthraquinone compounds; diphenoquinone compounds; malononitrile compounds Thiopyran compounds; 2,4,8-trinitrothioxanthone; 3,4,5,7-tetranitro-
Compounds having an oxidation-reduction potential within the above range are selected from fluorenone compounds such as 9-fluorenone; dinitroanthracene; dinitroacridine; nitroanthraquinone; and compounds having an electron accepting property such as dinitroanthraquinone. You.

Among them, the general formula (EA1):

[0038]

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[Wherein R ^a1 , R ^a2 , R ^a3 and R ^a4 are the same or different and each have a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a cycloalkyl group or a substituent. Shows a good amino group. A benzoquinone compound represented by the general formula (EA2):

[0040]

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[Wherein R ^a5 , R ^a6 , R ^a7 and R ^a8 are the same or different and each have a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a cycloalkyl group or a substituent. Shows a good amino group. The compound belonging to the diphenoquinone-based compound represented by the formula (1) and having an oxidation-reduction potential within the above range is preferably used.

The alkyl group in the above formula includes the same groups as described above. Examples of the aralkyl group include benzyl, benzhydryl, trityl, and phenethyl. Examples of the alkoxy group include methoxy, ethoxy, propoxy, t-butoxy,
C1-C6 such as pentyloxy and hexyloxy
And the aryl group includes, for example, phenyl, naphthyl and the like. Further, examples of the cycloalkyl group include cycloalkyl groups having 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of the amino group which may have a substituent include, for example, amino, monomethylamino, dimethylamino, monoethylamino, diethylamino and the like.

Specific examples of the benzoquinone compound include:
Although not limited thereto, for example, p-benzoquinone (redox potential -0.81 V) represented by the formula (EA1-1),
And 2,6-di-t-butyl-p-benzoquinone (redox potential -1.31 V) represented by (EA1-2).

[0044]

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Specific examples of the diphenoquinone compound include, but are not limited to, for example, 3,5-dimethyl-3 ', 5'-di-tert-butyl-formula represented by the formula (EA2-1).
4,4'-diphenoquinone (redox potential -0.86
V) and 3,5,3 ', 5'-tetrakis (t-butyl) -4,4'-diphenoquinone (redox potential -0.94 V) represented by the formula (EA2-2). .

[0046]

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These electron accepting compounds can be used alone or in combination of two or more.
Next, various materials used for the electrophotographic photosensitive member of the present invention will be described. <Hole transport agent> Examples of the hole transport agent include compounds represented by the following general formulas (HT1) to (HT13).

[0048]

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Where R^h1, R^h2, R^h3, R^h4, R^h5You
And R^h6Are the same or different and represent a hydrogen atom, a halogen atom
Having a substituent, an alkyl group which may have a substituent,
Aryl optionally having an alkoxy group or a substituent
Represents a hydroxyl group. a and b are the same or different and
Represents an integer, c, d, e and f are the same or different
Shows an integer of 1 to 5. A, b, c, d, e or
When f is 2 or more, each R ^h1, R^h2, R^h3, R^h4, R^h5You
And R^h6May be different. )

[0050]

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(Wherein R ^h7 , R ^h8 , R ^h9 , R ^h10 and R ^h11 are the same or different and each have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, G, h, i, and j are the same or different and each represents an integer of 1 to 5, and k represents an integer of 1 to 4.
When g, h, i, j or k is 2 or more, each R ^h7 ,
R ^h8, R ^h9, R ^h10 and R ^{h1 1} may be different. )

[0052]

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Where R^h12, R^h13, R^h14And R
^h15Are the same or different and are a hydrogen atom, a halogen atom,
Alkyl group which may have a substituent, may have a substituent
Alkoxy group or aryl group which may have a substituent
Is shown. R^h16Represents a hydrogen atom, a halogen atom, a cyano group,
A nitro group, an alkyl group which may have a substituent,
Optionally have an alkoxy group or a substituent
Indicates an aryl group. m, n, o and p are the same or different
And represents an integer of 1 to 5. q represents an integer of 1 to 6
You. When m, n, o, p or q is 2 or more, each
R^h12, R^h13, R ^h14, R^h15And R^h16Is different
May be. )

[0054]

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( ^Wherein R ^h17 , R ^h18 , R ^h19 and R ^h19
h20 is the same or different and is a hydrogen atom, a halogen atom,
It represents an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aryl group which may have a substituent. r, s, t and u are the same or different and 1
Represents an integer of from 5 to 5. When r, s, t or u is 2 or more, each of R ^h17 , R ^h18 , R ^h19 and R ^h20 may be different. )

[0056]

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(In the formula, R ^h21 and R ^h22 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. R ^h23 , R ^h24 , R ^h25 and R ^h22
h26 is the same or different and represents a hydrogen atom, an alkyl group or an aryl group. )

[0058]

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(In the formula, R ^h27 , R ^h28 and R ^h29 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0060]

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^Wherein R ^h30 , R ^h31 , R ^h32 and R ^h30
h33 is the same or different and is a hydrogen atom, a halogen atom,
It represents an alkyl group or an alkoxy group. )

[0062]

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( ^Wherein R ^h34 , R ^h35 , R ^h36 , R ^h37
And R ^h38 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. )

[0064]

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[0065] (wherein, R ^H39 represents a hydrogen atom or an alkyl group, R ^h40, R ^h41 and R ^{h4 2} are the same or different and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0066]

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[0067] (wherein, R ^h43, R ^h44 and R ^h45 are the same or different and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0068]

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( ^Wherein R ^h46 and R ^h47 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent or an alkoxy group which may have a substituent. R ^h48 And R ^h49 are the same or different,
It represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent. )

[0070]

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(Where R^h50, R^h51, R^h52,
R^h53, R^h54And R^h55Are the same or different, water
Atom, an alkyl group which may have a substituent,
Which may have an alkoxy group or a substituent
2 shows a reel group. α represents an integer of 1 to 10, and v, w,
x, y, z and β are the same or different and are 1 or 2
is there. Note that when v, w, x, y, z or β is 2,
Each R^h50, R^h51, R^h52, R ^h53, R^h54And R
^h55May be different. )

[0072]

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^Wherein R ^h56 , R ^h57 , R ^h58 and R ^h58
h59 is the same or different and is a hydrogen atom, a halogen atom,
Represents an alkyl group or an alkoxy group, and Ar is

[0074]

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Represents a group (Ar1), (Ar2) or (Ar3) represented by In the above-described hole transporting agent, as the alkyl group,
The same groups as described above can be mentioned. As the alkoxy group,
Examples thereof include groups having 1 to 6 carbon atoms such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, pentyloxy and hexyloxy. Examples of the aryl group include groups such as phenyl, tolyl, xylyl, biphenylyl, o-terphenyl, naphthyl, anthryl, and phenanthryl. As a halogen atom,
Fluorine, chlorine, bromine and iodine.

The substituents which may be substituted on the above groups include:
For example, halogen atom, amino group, hydroxyl group, carboxyl group which may be esterified, cyano group,
And an alkenyl group having 2-6 carbon atoms which may have an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and an aryl group. Further, the substitution position of the substituent is not particularly limited.

In the present invention, in addition to the above examples, a conventionally known hole transporting material, for example, 2,5
Oxadiazole compounds such as -di (4-methylaminophenyl) -1,3,4-oxadiazole; 9- (4
-Diethylaminostyryl) styryl compounds such as anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds, 1-phenyl-3-
Pyrazoline compounds such as (p-dimethylaminophenyl) pyrazoline, hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds,
Nitrogen-containing cyclic compounds such as thiadiazole-based compounds, imidazole-based compounds, pyrazole-based compounds, and triazole-based compounds, and condensed polycyclic compounds can be used.

In the present invention, one or more charge transporting agents are used in combination. When a charge transporting agent having a film-forming property such as polyvinyl carbazole is used, a binder resin is not necessarily required. Among the hole transport agents, in the present invention, the ionization potential (Ip) is from 4.8 to 4.8.
It is preferable to use one having a voltage of 5.6 eV.
Those having a mobility of 1 × 10 ⁻⁶ cm ² / V · sec or more at × 10 ⁵ V / cm are more preferable.

The use of a hole transporting agent having an ionization potential within the above range further reduces the residual potential,
The sensitivity is improved. Although the reason is not always clear, it is considered as follows. That is, the ease of injection of charge from the charge generating agent to the hole transporting agent is closely related to the ionization potential of the hole transporting agent, and when the ionization potential of the hole transporting agent is larger than the above range. Indicates that the degree of charge injection from the charge generating agent to the hole transporting agent is low, or the degree of hole transfer between the hole transporting agents is low, resulting in a decrease in sensitivity. . On the other hand, in a system in which a hole transporting agent and an electron transporting agent coexist, it is necessary to pay attention to the interaction between the two, more specifically, the formation of a charge transfer complex. When such a complex is formed between the two, recombination occurs between holes and electrons, and the mobility of charges as a whole decreases. When the ionization potential of the hole transporting agent is smaller than the above range, the tendency to form a complex with the electron transporting agent increases, and electron-hole recombination occurs. It is thought that this leads to a decrease in sensitivity.

Specific examples of the hole transporting agent which can be suitably used in the present invention include, for example, a compound represented by the formula (HT1-1) which belongs to the benzidine derivative represented by the general formula (HT1):

[0081]

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And the like. <Charge Generating Agent> Examples of the charge generating agent include compounds represented by the following general formulas (CG1) to (CG12). (CG1) Metal-free phthalocyanine

[0083]

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(CG2) oxotitanyl phthalocyanine

[0085]

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(CG3) Perylene pigment

[0087]

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(Wherein, R ^g1 and R ^g2 are the same or different and represent a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkanoyl group or aralkyl group having 18 or less carbon atoms) (CG4) ) Bisazo pigment

[0089]

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[Wherein A ¹ and A ² are the same or different and represent a coupler residue, and X is

[0091]

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(Wherein R ^g3 represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and the alkyl group, aryl group or heterocyclic group may have a substituent.
Represents 0 or 1. )

[0093]

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[0094]

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(In the formula, R ^g4 and R ^g5 are the same or different and each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group, an aryl group or an aralkyl group.)

[0096]

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[0097]

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[0098]

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(In the formula, R ^g6 represents a hydrogen atom, an ethyl group, a chloroethyl group or a hydroxyethyl group.)

[0100]

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Or

[0102]

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( ^Wherein , R ^g7 , R ^g8 and R ^g9 are the same or different and each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group, an aryl group or an aralkyl group). . (CG5) dithioketopyrrolopyrrole pigment

[0104]

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(In the formula, R ^g10 and R ^g11 are the same or different and each represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ^g12 and R ^g13 are the same or different and represent a hydrogen atom, an alkyl group or an aryl group. (CG6) Metal-free naphthalocyanine pigment

[0106]

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^Wherein R ^g14 , R ^g15 , R ^g16 and R ^g14
g17 is the same or different and represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. (CG7) Metal naphthalocyanine pigment

[0108]

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^Wherein R ^g18 , R ^g19 , R ^g20 and R ^g20
g21 is the same or different and represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and M represents Ti or V. ) (CG8) Squaraine pigment

[0110]

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( ^Wherein , R ^g22 and R ^g23 are the same or different and each represent a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom.) (CG9) Trisazo pigment

[0112]

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(Wherein Cp ₁ , Cp ₂ and Cp ₃ are the same or different and represent a coupler residue.) (CG10) Indigo pigment

[0114]

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( ^Wherein , R ^g24 and R ^g25 are the same or different and each represent a hydrogen atom, an alkyl group or an aryl group, and Z represents an oxygen atom or a sulfur atom.) (CG11) Azulhenium pigment

[0116]

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( ^Wherein , R ^g26 and R ^g27 are the same or different and each represent a hydrogen atom, an alkyl group or an aryl group.) (CG12) Cyanine pigment

[0118]

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( ^Wherein R ^g28 and R ^g29 are the same or different and each represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ^g30 and R ^g31 are the same or different and represent a hydrogen atom, an alkyl group or an aryl Represents a group.) In the above-described charge generating agent, as the alkyl group,
The same groups as described above can be mentioned. The alkyl group having 1 to 5 carbon atoms is obtained by removing hexyl from the aforementioned alkyl group having 1 to 6 carbon atoms. The substituted or unsubstituted alkyl group having 18 or less carbon atoms is a group containing octyl, nonyl, decyl, dodecyl, tridecyl, pentadecyl, octadecyl, and the like in addition to the above-described alkyl group having 1 to 6 carbon atoms. Examples of the cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,
Examples thereof include groups having 3 to 8 carbon atoms such as cycloheptyl and cyclooctyl. Examples of the alkoxy group, the aryl group, and the aralkyl group include the same groups as described above. Examples of the alkanoyl group include formyl, acetyl, propionyl, butyryl, pentanoyl, hexanoyl and the like.

Examples of the heterocyclic group include thienyl,
Pyrrolyl, pyrrolidinyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, 2
H-imidazolyl, pyrazolyl, triazolyl, tetrazolyl, pyranyl, pyridyl, piperidyl, piperidino, 3-morpholinyl, morpholino, thiazolyl and the like. Further, it may be a heterocyclic group condensed with an aromatic ring.

The substituents which may be substituted on the above groups include:
For example, halogen atom, amino group, hydroxyl group, carboxyl group which may be esterified, cyano group, carbon number 1-6
And an alkenyl group having 2 to 6 carbon atoms which may have an aryl group. A ¹ , A ² and Cp ₁ , Cp ₂ , Cp ₃
Examples of the coupler residue represented by are groups represented by the following general formulas (21) to (27).

[0122]

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In each formula, R ^g32 represents a carbamoyl group, a sulfamoyl group, an allofanoyl group, an oxamoyl group, an anthraniloyl group, a carbazoyl group, a glycyl group, a hydantoyl group, a phthalamoyl group or a succinamoyl group. These groups include a halogen atom, a phenyl group which may have a substituent, a naphthyl group which may have a substituent, a nitro group, a cyano group, an alkyl group, an alkenyl group,
It may have a substituent such as a carbonyl group or a carboxyl group.

R ^g33 represents an atomic group necessary for forming an aromatic ring, a polycyclic hydrocarbon or a heterocyclic ring by condensing with a benzene ring, and these rings have the same substituents as described above. You may. R ^g34 represents an oxygen atom, a sulfur atom or an imino group. R ^g35 represents a divalent chain hydrocarbon group or an aromatic hydrocarbon group, and these groups may have the same substituent as described above.

R ^g36 represents an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, and these groups may have the same substituent as described above. R ^g37 represents a divalent chain hydrocarbon group, an aromatic hydrocarbon group or any of the above general formulas (25) and (26)
In the following formula (28):

[0126]

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Represents an atomic group necessary for forming a heterocyclic ring together with the moiety represented by the formula: and these rings may have the same substituents as described above. R ^g38 represents a hydrogen atom, an alkyl group, an amino group, a carbamoyl group, a sulfamoyl group, an allophanoyl group, a carboxyl group, an alkoxycarbonyl group, an aryl group or a cyano group, and the groups other than the hydrogen atom have the same substituents as described above. You may have.

R ^g39 represents an alkyl group or an aryl group, and these groups may have the same substituents as described above. Examples of the alkenyl group include vinyl, allyl,
2-butenyl, 3-butenyl, 1-methylallyl, 2-
An alkenyl group having 2 to 6 carbon atoms such as pentenyl and 2-hexenyl is exemplified.

In R ^g33 , ^examples of the atomic group necessary for condensing with the benzene ring to form an aromatic ring include an alkylene group having 1 to 4 carbon atoms such as methylene, ethylene, propylene, and butylene. . Examples of the aromatic ring formed by the condensation of R ^g33 and a benzene ring include a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, and a naphthacene ring.

In R ^g33 , the atomic group necessary for condensing with a benzene ring to form a polycyclic hydrocarbon includes, for example, the above-mentioned alkylene group having 1 to 4 carbon atoms, or a carbazole ring or a benzocarbazole ring. And a dibenzofuran ring. In R ^g33 , the atomic groups necessary for condensing with a benzene ring to form a heterocyclic ring include, for example, benzofuranyl, benzothiophenyl,
Indolyl, 1H-indolyl, benzoxazolyl,
Benzothiazolyl, 1H-indolyl, benzimidazolyl, chromenyl, chromanyl, isochromanyl, quinolinyl, isoquinolinyl, cinnolinyl, phthalazinyl, quinazonylyl, quinoxalinyl, dibenzofuranyl, carbazolyl, xanthenyl, acridinyl, phenanthrinyl, phenazinyl, etc. .

Examples of the aromatic heterocyclic group formed by the condensation of R ^g33 and a benzene ring include thienyl, furyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, pyridyl, Thiazolyl is mentioned. Further, it may be a heterocyclic group condensed with another aromatic ring (for example, benzofuranyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, quinolyl and the like).

In R ^g35 and R ^g37 , ^examples of the divalent chain hydrocarbon group include ethylene, propylene and butylene, and examples of the divalent aromatic hydrocarbon group include phenylene, naphthylene and phenanthrylene. can give. In R ^g36 , ^examples of the heterocyclic group include pyridyl, pyrazyl, thienyl, pyranyl, indolyl and the like.

In R ^g37 , ^examples of the atomic group necessary for forming a heterocyclic ring together with the moiety represented by the formula (28) include phenylene, naphthylene, phenanthrylene, ethylene, propylene, butylene and the like. Examples of the aromatic heterocyclic group formed by the above R ^g37 and the moiety represented by the formula (28) include benzimidazole, benzo [f] benzimidazole, dibenzo [e, g] benzimidazole, Pyrimidine and the like. These groups may have the same substituents as described above.

In the above R ^g38 , ^examples of the alkoxycarbonyl group include groups such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl and butoxycarbonyl. In the present invention, in addition to the above-described charge generating agents, for example, selenium, selenium-tellurium, amorphous silicon, pyrylium salt, anthanthrone-based pigment, triphenylmethane-based pigment, slen-based pigment, toluidine-based pigment, pyrazoline-based pigment And conventionally known charge generators such as quinacridone pigments.

The charge generating agents exemplified above can be used alone or in combination of two or more so as to have an absorption wavelength in a desired region. At this time, in connection with the use of a hole transporting agent having an ionization potential of 4.8 to 5.6 eV, a charge generating agent having a balance with the hole transporting agent, specifically, an ionization potential of 4.8-6.0e
It is preferable to use a charge generating agent having a V in the range of 5.0 to 5.8 eV, in particular, from the viewpoint of reducing the residual potential and improving the sensitivity.

Particularly preferred charge generating agents include X-type non-metallic phthalocyanine represented by the above general formula (CG1),
Phthalocyanine pigments such as oxotitanyl phthalocyanine represented by (CG2); and perylene pigments represented by the general formula (CG3). As the perylene pigment,
Especially the general formula (CG3a):

[0137]

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^Wherein R ^g40 , R ^g41 , R ^g42 and R ^g40
g43 is the same or different and represents a hydrogen atom, an alkyl group, an alkoxyl group or an aryl group. The compound represented by the formula (1) is preferably used. In the above general formula (CG3a),
Alkyl group corresponding to substituent R ^{g4 0} to R ^g43, examples of the alkoxy group and aryl group, wherein the same group.

Among the charge generators, the phthalocyanine pigments are suitable as charge generators for photoconductors having sensitivity in the wavelength region of 700 nm or more. That is, since the phthalocyanine-based pigment is excellent in matching with the naphthoquinone derivative (electron transporting agent) represented by the general formula (1), an electrophotographic photoreceptor using both of them has high sensitivity in the above wavelength region, Therefore, it can be suitably used in a digital optical system image forming apparatus using a light source having a wavelength of 700 nm or more.

Further, perylene pigments are suitable as charge generating agents for photoreceptors having sensitivity in the visible region. In particular, the perylene pigment (CG3a) is excellent in matching with the naphthoquinone derivative (electron transport agent) represented by the general formula (1), and the electrophotographic photoreceptor using both of them has high sensitivity in the visible region. Therefore, it can be suitably used for an analog optical system image forming apparatus using a light source having a wavelength in the visible region. <Binder Resin> As the binder resin for dispersing the above components, various resins conventionally used in organic photosensitive layers can be used. For example, styrene polymers and styrene-butadiene copolymers can be used. Polymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer,
Acrylic copolymer, styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, ionomer, vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide , Polyurethane, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, polyester resin and other thermoplastic resins, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, etc. Crosslinkable thermosetting resins, and photocurable resins such as epoxy acrylate and urethane-acrylate, and the like are also included. These binder resins can be used alone or in combination of two or more. Suitable resins include styrene polymers, acrylic polymers, styrene-acrylic copolymers, polyesters, alkyd resins, polycarbonates, polyarylates and the like.

Next, a method for producing the electrophotographic photosensitive member of the present invention will be described. In order to obtain a single-layer type electrophotographic photoreceptor, a coating solution prepared by dissolving or dispersing a predetermined electron transporting agent in a suitable solvent together with a charge generating agent, a hole transporting agent, a binder resin and the like is applied by means such as coating. May be applied onto a conductive substrate and dried. In the case of a single-layer type photoconductor, the binder resin 1
0.1 to 50 parts by weight of the charge generating agent with respect to 00 parts by weight,
Preferably, it is blended in a ratio of 0.5 to 30 parts by weight, and the electron transporting agent is blended in a ratio of 5 to 100 parts by weight, preferably 10 to 80 parts by weight. In addition, the hole transporting agent is 5 to 500
It is added in a ratio of 25 parts by weight, preferably 25 to 200 parts by weight. Further, the total amount of the hole transporting agent and the electron transporting agent is suitably 20 to 500 parts by weight, preferably 30 to 200 parts by weight, based on 100 parts by weight of the binder resin. When the electron-accepting compound is contained in the single-layer photosensitive layer, the amount of the electron-accepting compound is 0.1 to 100 parts by weight based on 100 parts by weight of the binder resin.
It is appropriate to add 40 parts by weight, preferably 0.5 to 20 parts by weight.

The single-layer type photosensitive layer has a thickness of 5 to 100.
μm, preferably 10 to 50 μm. In order to obtain a laminated electrophotographic photoreceptor, first, a charge generating layer containing a charge generating agent is formed on a conductive substrate by means such as vapor deposition or coating, and then an electron transporting agent is formed on the charge generating layer. A charge transport layer may be formed by applying a coating solution containing the resin and a binder resin by means such as coating and drying.

In the laminate type photoreceptor, the charge generating agent and the binder resin constituting the charge generating layer can be used in various ratios, but the charge generating agent is added to 100 parts by weight of the binder resin. 5 to 1000 parts by weight, preferably 30 to 500 parts
It is appropriate to mix them in parts by weight. When the charge generating layer contains an electron-accepting compound, the electron-accepting compound is preferably blended in an amount of 0.1 to 40 parts by weight, preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the binder resin. Appropriate. When the charge generation layer contains an electron transporting agent, the electron transporting agent is added in an amount of 0.1 to 100 parts by weight of the binder resin.
It is appropriate to add 5 to 50 parts by weight, preferably 1 to 40 parts by weight.

The electron transporting agent and the binder resin constituting the charge transporting layer can be used in various proportions within a range not inhibiting the transport of the charge and within a range not causing crystallization. An electron transporting agent is added to 100 parts by weight of the binder resin so that the generated charges can be easily transported.
It is suitable to mix at 500 parts by weight, preferably 25 to 100 resin. When the charge-transporting layer contains an electron-accepting compound, the electron-accepting compound is added to the binder resin 10.
0.1 to 40 parts by weight, preferably 0.1 to 40 parts by weight, based on 0 parts by weight.
It is appropriate to mix in 5 to 20 parts by weight.

The thickness of the laminated photosensitive layer is about 0.01 to 5 μm, preferably 0.1 to 3 μm for the charge generation layer.
And the thickness of the charge transport layer is 2 to 100 μm, preferably about 5 to 50 μm. In the case of a single-layer type photoreceptor, between the conductive substrate and the photosensitive layer, and in the case of the laminated type photoreceptor, between the conductive substrate and the charge generation layer, and between the conductive substrate and the charge transport layer. Or between the charge generation layer and the charge transport layer,
A barrier layer may be formed as long as the characteristics of the photoconductor are not impaired. Further, a protective layer may be formed on the surface of the photoconductor.

Each of the single-layer type and laminated type photosensitive layers may contain various additives known per se such as an antioxidant, a radical scavenger, a singlet quencher, and the like, as long as the electrophotographic characteristics are not adversely affected. Deterioration inhibitors such as ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be added.

In order to improve the sensitivity of the photosensitive layer,
For example, known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator. In addition, a trypto anthrin derivative which is an electron transport agent
Along with (1) , other conventionally known electron transporting agents may be contained in the photosensitive layer. As such an electron transporting agent, various compounds having a high electron transporting ability, for example, the above-mentioned general formula
In addition to the benzoquinone compound of (EA1) and the diphenoquinone compound of general formula (EA2) , the following general formulas (ET1) to (ET13)
And the like.

[0148]

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(Wherein, R ^e1 , R ^e2 , R ^e3 , R ^e4 and R
^e5 are the same or different, a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent,
It represents an aryl group which may have a substituent, an aralkyl group which may have a substituent, a phenoxy group which may have a substituent, or a halogen atom. )

[0150]

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(Wherein R ^e6 is an alkyl group, R ^e7 is an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, Represents an aralkyl group, a halogen atom or a halogenated alkyl group which may have a group, γ represents an integer of 0 to 5. When γ is 2 or more, each ^{Re 7} may be different from each other. )

[0152]

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(In the formula, R ^e8 and R ^e9 are the same or different and each represents an alkyl group. Δ represents an integer of 1 to 4,
Represents an integer of 0 to 4. Note that when δ and ε is 2 or more, each R ^e8 and R ^e9 may be different. )

[0154]

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(In the formula, R ^e10 represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a halogenated alkyl group or a halogen atom.
Is an integer. When η is 2 or more, each ^{Re 10} may be different. )

[0156]

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(In the formula, R ^e11 represents an alkyl group, and σ is an integer of 1 to 4. When σ is 2 or more, each R
^e11 may be different. )

[0158]

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(In the formula, R ^e12 and R ^e13 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an aralkyloxycarbonyl group, an alkoxy group, a hydroxyl group, a nitro group, or a cyano group. Base:
Shows O, N-CN or C (CN) ₂ . )

[0160]

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( ^Wherein R ^e14 represents a hydrogen atom, a halogen atom, an alkyl group or a phenyl group which may have a substituent, R ^e15 represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, A phenyl group, an alkoxycarbonyl group, an N-alkylcarbamoyl group, a cyano group or a nitro group which may have a substituent.
Is an integer of 1 to 3. When λ is 2 or more, each R
^e15 may be different from each other. )

[0162]

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(In the formula, θ is an integer of 1 to 2.)

[0164]

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(In the formula, R ^e16 and R ^e17 are the same or different and each represent a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cyano group, a nitro group, or an alkoxycarbonyl group. 1-3 is an integer. Note, [nu or ξ is when 2 or more, each R ^e16 and R ^e17 may be different from each other.)

[0166]

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(In the formula, R ^e18 and R ^e19 are the same or different and each represents a phenyl group, a polycyclic aromatic group or a heterocyclic group, and these groups may have a substituent.)

[0168]

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(In the formula, R ^e20 represents an amino group, a dialkylamino group, an alkoxy group, an alkyl group or a phenyl group, and π is an integer of 1-2. When π is 2,
Each R ^{e2 0} may be different from each other. )

[0170]

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( ^Wherein R ^e21 represents a hydrogen atom, an alkyl group,
It represents an aryl group, an alkoxy group or an aralkyl group. )

[0172]

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(Wherein, ^{Re e22} represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a phenyl group which may have a substituent, an alkoxycarbonyl group,
It represents an N-alkylcarbamoyl group, a cyano group or a nitro group. μ is an integer of 1 to 3. When μ is 2 or more, each ^{Re 22} may be different from each other. And the like, and malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, and maleic anhydride. ,
And dibromomaleic anhydride.

In the electron transporting agent exemplified above, the alkyl group, the alkoxy group, the aryl group, the aralkyl group and the halogen atom include the same groups as described above. Examples of the halogenated alkyl group include chloromethyl,
Bromomethyl, fluoromethyl, iodomethyl, 2-chloroethyl, 1-fluoroethyl, 3-chloropropyl, 2-bromopropyl, 1-chloropropyl, 2-chloro-1-methylethyl, 1-bromo-1-methylethyl, 4 -Iodobutyl, 3-fluorobutyl, 3-chloro-2-methylpropyl, 2-iodo-2-methylpropyl, 1-fluoro-2-methylpropyl, 2-chloro-1,1-dimethylethyl, 2-bromo- Alkyl groups such as 1,1-dimethylethyl, 5-bromopentyl and 4-chlorohexyl are halogenated alkyl groups having 1 to 6 carbon atoms.

Examples of the polycyclic aromatic group include naphthyl, phenanthryl, anthryl and the like. Examples of the heterocyclic group include thienyl, pyrrolyl, pyrrolidinyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, 2H-imidazolyl, pyrazolyl, triazolyl, tetrazolyl, pyranyl, pyridyl, piperidyl, piperidino, 3-morpholinyl, morpholino, and thiazolyl. Is raised. Further, it may be a heterocyclic group condensed with an aromatic ring.

The substituents which may be substituted on the above groups include:
For example, halogen atom, amino group, hydroxyl group, carboxyl group which may be esterified, cyano group, carbon number 1-6
An alkyl group, an alkoxy group having 1 to 6 carbon atoms, and an alkenyl group having 2 to 6 carbon atoms which may have an aryl group. As the conductive substrate used for the photoreceptor of the present invention, various materials having conductivity can be used. For example, aluminum, iron, copper, tin, platinum, silver,
Coated with a single metal such as vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, brass, or a plastic material on which the above metal is deposited or laminated, aluminum iodide, tin oxide, indium oxide, etc. Glass and the like.

The conductive substrate may be in the form of a sheet, a drum, or the like, as long as the substrate itself has conductivity or the surface of the substrate has conductivity. In addition, the conductive substrate preferably has sufficient mechanical strength when used. The photosensitive layer according to the invention is manufactured by applying a coating solution obtained by dissolving or dispersing a resin composition containing the above-described components in a solvent onto a conductive substrate and drying the coating solution.

That is, a charge generating agent, a charge transporting agent, a binder resin and the like are mixed together with a suitable solvent in a known method, for example, a roll mill, a ball mill, an attritor,
A coating solution may be prepared by dispersing and mixing using a paint shaker or an ultrasonic disperser, and then applied and dried by a known means. Various organic solvents can be used as a solvent for preparing the coating liquid, for example, alcohols such as methanol, ethanol, isopropanol and butanol, n-hexane, octane, aliphatic hydrocarbons such as cyclohexane, benzene, and the like. Aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride and chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, cyclohexanone, etc. Ketones, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide, dimethylsulfoxide and the like. These solvents can be used alone or in combination of two or more.

Further, in order to improve the dispersibility of the charge transporting agent and the charge generating agent and the smoothness of the surface of the photosensitive layer, a surfactant is used.
A leveling agent or the like may be used. As described above, since the tryptoanthrin derivative of the present invention has excellent electron transporting ability, an electrophotographic photoreceptor using this as an electron transporting agent has high sensitivity. Therefore, when the photoconductor of the present invention is used, the speed of an image forming apparatus such as an electrostatic copying machine can be increased.

[0180]

The present invention will be described below with reference to examples. << Tryptoanthrin derivative >> Synthesis Example 1 Formula (1a-1):

[0181]

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11 g of isatoic anhydride (0.0 g
68 mol) and the formula (1b-1):

[0183]

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10 g (0.068 mol) of isatin represented by the following formula was put in a 200 ml eggplant flask together with 20 ml of pyridine, and the mixture was heated and reacted under reflux for 6 hours. The solid precipitated in the above is filtered off to obtain a compound of the formula (1c-1):

[0185]

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6.46 g of tryptoanthrin represented by
(38% yield). Next, 5.0 g (0.02 mol) of this tryptoanthrin was added to 100 ml of ethanol together with 1.0 g of sodium ethoxide, and the mixture was stirred at room temperature. Next, 2.1 g (0.
A solution prepared by dissolving 032 mol) of malononitrile in 50 ml of ethanol was added, and the mixture was stirred at 40 to 50 ° C. for 1 hour. The reaction solution was poured into water, and further extracted with chloroform three times.

Next, the separated organic phase was washed with dilute sulfuric acid, dried over anhydrous magnesium sulfate, and the solvent was distilled off. The resulting crystals were further purified by silica gel chromatography to give a red color. Equation (1-1):

[0188]

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5.0 g of the compound represented by the following formula (yield: 85.1)
%). The melting point of this compound is 213 to 215 ° C, and the results of elemental analysis are as follows. FIG. 2 shows the infrared absorption spectrum of the compound.

Synthesis Example 2 11 g of isatoic anhydride represented by the formula (1a-1) (0.0 g
68 mol) and the formula (1b-2):

[0191]

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5-isopropylisatin 1 represented by
2.9 g (0.068 mol) was put in a 200 ml eggplant flask together with 20 ml of pyridine, and the mixture was heated and reacted under reflux for 6 hours, and then the crystals precipitated in the cooled reaction solution were filtered. Apart from the formula (1c-2):

[0193]

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8.3 g (yield: 42%) of 6-isopropyltryptoanthrin represented by the following formula was obtained. Next, 0.17 g (7 mmol) of sodium hydride and 7 ml of dehydrated tetrahydrofuran were placed in a 100 ml two-necked flask, and stirred under an argon gas stream while the formula: (1d-1)

[0195]

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Phosphite derivative 1.5
A solution of 6 g (7 mmol) in 10 ml of tetrahydrofuran was added dropwise, and the mixture was stirred at room temperature for 3 hours.
Next, a solution of 0.99 g (3.4 mmol) of the above-mentioned 6-isopropyltryptoanthrin dissolved in 5 ml of tetrahydrofuran was added dropwise to this solution, and the mixture was further stirred at room temperature for 3 hours.

After the reaction, the reaction solution was added to ice water and extracted with chloroform. Next, the separated organic layer was washed with water, chloroform was distilled off, and the residue was purified by silica gel chromatography (developing solvent: chloroform).
(1-2):

[0198]

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0.43 g of the compound represented by the following formula (yield: 35.
0%). The melting point of this compound is from 205 to 207 ° C, and the results of elemental analysis are as follows. FIG. 3 shows the infrared absorption spectrum of the above compound.

Synthesis Example 3 In place of the phosphite derivative of the formula (1d-1), the compound of the formula (1d-
2):

[0201]

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The phosphite derivative 1.6 represented by the formula:
Compound (1-3) was prepared in the same manner as in Synthesis Example 2 except that 7 g (7 mmol) was used.

[0203]

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0.56 g of the compound represented by the formula (yield 44.
0%). The melting point of this compound is 200 to 201 ° C., and the results of elemental analysis are as follows. FIG. 4 shows the infrared absorption spectrum of the compound. << Photoconductor for Digital Light Source (Single-Layer Type) >> Example 1 5 parts by weight of an X-type metal-free phthalocyanine (Ip = 5.38 eV) represented by the above formula (CG1), which is a charge generating agent, and an electron transporting agent And 30 parts by weight of the compound represented by the formula (1-1) obtained in Synthesis Example 1 and the compound represented by the formula (H
T1-1), N, N, N ', N'-tetrakis (p
-Methylphenyl) -3,3'-dimethylbenzidine (Ip = 5.56 eV) 50 parts by weight and a binder resin polycarbonate were mixed with 800 parts by weight of tetrahydrofuran in a ball mill for 50 hours and dispersed. Thus, a coating solution for a single-layer type photosensitive layer was prepared.

Next, this coating solution was applied onto an aluminum base tube as a conductive base material by a dip coating method.
Dry with hot air at 00 ° C for 60 minutes to form a film with a thickness of 15 to 20 μm.
Then, a photosensitive layer for a digital light source was manufactured by forming a single-layer photosensitive layer of m. Example 2 Example 1 was repeated except that X-type metal-free phthalocyanine was replaced with 5 parts by weight of oxotitanyl phthalocyanine (Ip = 5.32 eV) represented by the above formula (CG2) as the charge generator. Similarly, a photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured.

Examples 3 and 4 As the electron transporting agent, 30 parts by weight of the compound represented by the formula (1-2) obtained in Synthesis Example 2 was used instead of the compound of the formula (1-1). Except for the above, a photoconductor for a digital light source having a single-layer type photoconductive layer was manufactured in the same manner as in Examples 1 and 2. Examples 5 and 6 Except for using 30 parts by weight of the compound represented by the formula (1-3) obtained in Synthesis Example 3 in place of the compound of the formula (1-1) as the electron transporting agent, In the same manner as in Examples 1 and 2, a photoconductor for a digital light source having a single-layer type photosensitive layer was manufactured.

Comparative Examples 1 and 2 The electron transporting agent was replaced by the compound of the above formula (1-1).
In the same manner as in Examples 1 and 2, except that 30 parts by weight of 3,5-dimethyl-3 ', 5'-di-tert-butyl-4,4'-diphenoquinone represented by (EA2-1) was used. Thus, a photoconductor for a digital light source having a single-layer type photoconductive layer was manufactured.

Comparative Example 3 The procedure of Example 1 was repeated except that no electron transporting agent was contained.
A photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured. For the electrophotographic photoreceptors of each of the above Examples and Comparative Examples,
The following light sensitivity test I was performed to evaluate its characteristics.

Light Sensitivity Test I Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the electrophotographic photosensitive members of Examples and Comparative Examples, and the surfaces thereof were charged to +700 V. Next, a wavelength of 780 nm (half-width 20 nm) and a light intensity of 16 μW / c were extracted from a white light of a halogen lamp, which is an exposure light source of the tester, with a bandpass filter.
m ² monochromatic light is irradiated onto the surface of the charged photoreceptor (irradiation time: 80 msec.), and 330 m.
msec. The surface potential at the elapse of time is represented by
It was measured as L (V). The smaller the post-exposure potential VL (V), the higher the sensitivity of the photoreceptor.

The results are shown in Table 1.

[0211]

[Table 1]

<< Photoreceptor for Digital Light Source (Single Layer Type-Electron Accepting Compound Combined System) >> Example 7 An electron accepting compound, p represented by the above formula (EA1-1)
A photoconductor for a digital light source having a single-layer type photosensitive layer was manufactured in the same manner as in Example 1, except that 10 parts by weight of benzoquinone (redox potential -0.81 V) was added.

Example 8 As an electron-accepting compound, p-benzoquinone was used in place of p-benzoquinone.
2,6-di-tert-butyl-p- represented by the formula (EA1-2)
A photoreceptor for a digital light source having a single-layer type photosensitive layer was produced in the same manner as in Example 7, except that 10 parts by weight of benzoquinone (redox potential -1.31 V) was added.

Example 9 As an electron accepting compound, instead of p-benzoquinone,
3,5-dimethyl-3 'represented by the formula (EA2-1),
A digital light source having a single-layer photosensitive layer in the same manner as in Example 7, except that 10 parts by weight of 5'-di-t-butyl-4,4'-diphenoquinone (redox potential -0.86 V) was added. Photoreceptor was manufactured.

Example 10 As an electron-accepting compound, p-benzoquinone was used in place of p-benzoquinone.
10 parts by weight of 3,5,3 ', 5'-tetrakis (t-butyl) -4,4'-diphenoquinone (redox potential -0.94 V) represented by the formula (EA2-2) is added. A photosensitive member for a digital light source having a single-layer type photosensitive layer was manufactured in the same manner as in Example 7 except for the above.

Examples 11 to 14 In place of the compound of the formula (1-1), 30 parts by weight of the compound of the formula (1-2) obtained in Synthesis Example 2 was used in place of the compound of the formula (1-1). Except for the above, a photoconductor for a digital light source having a single-layer type photoconductive layer was manufactured in the same manner as in Examples 7 to 10. Examples 15 to 18 Except for using 30 parts by weight of the compound represented by the formula (1-3) obtained in Synthesis Example 3 in place of the compound of the formula (1-1) as the electron transporting agent, In the same manner as in Examples 7 to 10, a photoconductor for a digital light source having a single-layer type photoconductive layer was manufactured.

With respect to the electrophotographic photosensitive member of each of the above embodiments,
The above-mentioned light sensitivity test I was performed, and its characteristics were evaluated. Table 2 shows the results.

[0218]

[Table 2]

<< Photoconductor for Digital Light Source (Laminated Type) >> Example 19 100 parts by weight of X-type metal-free phthalocyanine represented by the above formula (CG1) as a charge generating agent and 100 parts by weight of polyvinyl butyral as a binder resin Was mixed with 2,000 parts by weight of tetrahydrofuran in a ball mill for 50 hours and dispersed to prepare a coating solution for the charge generation layer.

Next, this coating solution was applied onto an aluminum tube as a conductive base material by a dip coating method.
The resultant was dried with hot air at 00 ° C. for 60 minutes to form a charge generation layer having a thickness of 1 μm. Next, 100 parts by weight of the compound represented by the formula (1-1) obtained in Synthesis Example 1 as an electron transporting agent and 100 parts by weight of polycarbonate as a binder resin were added together with 800 parts by weight of toluene. The mixture was mixed and dispersed in a ball mill for 50 hours to prepare a coating solution for the charge transport layer.

Next, this coating solution was applied on the charge generation layer by dip coating and dried with hot air at 100 ° C. for 60 minutes to form a charge transport layer having a thickness of 20 μm. A photoreceptor having a photosensitive layer for a digital light source was manufactured. Example 20 The procedure of Example 20 was repeated, except that the compound of the formula (1-2) was replaced with the compound of the formula (1-1), and the compound of the formula (1-2) was 100 parts by weight. In the same manner as in Example 19, a photoreceptor for a digital light source having a laminated photosensitive layer was manufactured.

Example 21 An electron transporting agent was replaced by the compound of the formula (1-1) in place of the compound of the formula (1-1), except that 100 parts by weight of the compound of the formula (1-3) obtained in Synthesis Example 3 was used. In the same manner as in Example 19, a photoconductor for a digital light source having a laminated photosensitive layer was manufactured. Comparative Example 4 As the electron transporting agent, the above-mentioned formula was used in place of the compound of the formula (1-1).
Except that 100 parts by weight of 3,5-dimethyl-3 ', 5'-di-tert-butyl-4,4'-diphenoquinone represented by (EA2-1) was used, A photoreceptor for a digital light source having a laminated photosensitive layer was manufactured.

With respect to the electrophotographic photosensitive members of the above Examples and Comparative Examples, the above-described photosensitivity test I was performed, and the characteristics were evaluated. Table 3 shows the results.

[0224]

[Table 3]

<< Photoreceptor for Analog Light Source (Single-Layer Type) >> Examples 22 to 24, Comparative Example 5 As the charge generator, a perylene pigment of the general formula (CG3a) was used instead of the X-type non-metallic phthalocyanine. Expression (CG3
a-1):

[0226]

Embedded image

(Ip = 5.50 eV)
Except that 5 parts by weight were used, a photoconductor for an analog light source having a single-layer type photoconductive layer was manufactured in the same manner as in Examples 1, 3, 5, and Comparative Example 1. Comparative Example 6 A photoconductor for an analog light source having a single-layer type photosensitive layer was manufactured in the same manner as in Examples 22 to 24 and Comparative Example 5 except that the electron transporting agent was not contained.

The electrophotographic photoreceptors of the above Examples and Comparative Examples were subjected to the following photosensitivity test II to evaluate the characteristics. Light Sensitivity Test II Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the electrophotographic photosensitive members of the respective examples and comparative examples, and the surfaces thereof were charged to +700 V.

Next, white light (light intensity: 147 μW / cm ² ) of a halogen lamp, which is an exposure light source of the tester, was
Irradiation on the surface of the charged photoreceptor (irradiation time 50 ms)
ec. ) And 330 msec. The surface potential at the time when the elapsed time was measured as a post-exposure potential VL (V). The smaller the post-exposure potential VL (V), the higher the sensitivity of the photoreceptor.

Table 4 shows the results.

[0231]

[Table 4]

<< Photoconductor for Analog Light Source (Laminated Type) >> Examples 25 to 27, Comparative Example 7 A perylene pigment represented by the above formula (CG3a-1) as a charge generator instead of the X-type non-metallic phthalocyanine Examples 19 to 21 and Comparative Example 4 except that 100 parts by weight were used.
In the same manner as in the above, a photoconductor for an analog light source having a laminated photosensitive layer was manufactured.

With respect to the electrophotographic photosensitive members of the above Examples and Comparative Examples, the above-described photosensitivity test II was performed, and the characteristics were evaluated. Table 5 shows the results.

[0234]

[Table 5]

[0235]

The tryptoanthrine derivative of the present invention is
It has excellent electron transportability, and has good solubility in a solvent and compatibility with a binder resin. Therefore, an electrophotographic photoreceptor using the tryptoanthrin derivative of the present invention as an electron transporting agent has high sensitivity. When the above tryptoantrine derivative is used in combination with an electron accepting compound having a specific oxidation-reduction potential, the sensitivity of the photoreceptor can be further improved.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a pulling voltage (V) and a current (μA) for obtaining an oxidation-reduction potential of an electron-accepting compound.

FIG. 2 is a graph showing an infrared absorption spectrum of the compound synthesized in Synthesis Example 1 of the present invention.

FIG. 3 is a graph showing an infrared absorption spectrum of the compound synthesized in Synthesis Example 2 of the present invention.

FIG. 4 is a graph showing an infrared absorption spectrum of the compound synthesized in Synthesis Example 3 of the present invention.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Seimasa Watanabe 1-2-28 Tamazo, Chuo-ku, Osaka City, Osaka Prefecture Inside Mita Industries Co., Ltd. (72) Inventor Hirofumi Kawaguchi 1-2-2 Tamazo, Chuo-ku, Osaka City, Osaka Prefecture No. 28 Mita Kogyo Co., Ltd. (56) Reference JP-A-52-131538 (JP, A) JP-A-52-111923 (JP, A) JP-A-58-179842 (JP, A) JP-A-61 173256 (JP, A) JP-A 1-254685 (JP, A) JP-A 5-333574 (JP, A) JP-A 8-295692 (JP, A) Tetrahedron, 41 (14), 2883-4 (1985) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09B 57/00 C07D 487/04 G03G 5/06 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. An electrotransporting agent on a conductive substrate , represented by the following general formula (1): [Wherein R ^1A and R ^1B are the same or different and are a hydrogen atom, an alkyl group, an acyl group, an alkoxycarbonyl group,
Or a cyano group. However, R ^1A and R ^1B are not hydrogen atoms at the same time. R ^2A , R ^2B , R ^2C , R ^2D , R ^3A , R ^3B ,
R ^3C and R ^3D are the same or different and represent a hydrogen atom or an alkyl group which may have a substituent. ] An electrophotographic photoreceptor comprising a photosensitive layer containing a tryptoanthrin derivative represented by the following formula: Wherein the photosensitive layer is, claims also contains an electron-accepting compound having a redox potential of -0.8 to-1.4V
Item 8. The electrophotographic photosensitive member according to Item 1 .