JPH0940672A - Tryptanthrine derivative and electrophotographic receptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new tryptanthrine derivative which is suitable as an electron transport agent and can be a high-sensitivity electrophotographic receptor and is useful in an image former for an electrostatic type copying machine, a laser beam printer, a plain paper facsimile or the like. SOLUTION: This derivative is represented by formula I (one of R<1> A, R<1> B, R<1> C, R<1> D, R<2> A, R<2> B, R<2> C, R<2> D is cyano and the others are each H, an alkyl), typically 6-cyanotryptanthrine of formula II. Said derivative (R<2> C is cyano) is obtained by reaction of a derivative of isatic acid anhydride with a brominated isatin derivative of formula IV in a solvent to a brominated tryptanthrine derivative followed by reaction of the brominated product with copper cyanide to replace the bromine atom with a cyano group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel tryptoanthrin derivative and an electrophotographic apparatus using the same, which is used in an image forming apparatus such as an electrostatic copying machine, a laser beam printer, a plain paper facsimile machine or the like. It relates to a photoconductor.

[0002]

2. Description of the Related Art In the above-mentioned image forming apparatus, a charge generating agent that generates an electric charge by light irradiation, a charge transferring agent that transports the generated electric charge, and a binder resin that disperses these substances to form a layer are used. The so-called organic photoconductor (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 type photosensitive layer, a charge transport layer having a thickness larger than that of the charge generation layer is generally disposed as the outermost layer from the viewpoint of mechanical strength.

The charge transporting agents used in these photoconductors include those having a hole transporting property and those having an electron transporting property. Among the charge transporting agents currently known, they are practical for the photoconductor. Most of those having high carrier mobility capable of imparting various sensitivities have a hole transporting property. For this reason, the organic photoconductors currently in practical use are of the negative charging type in the case of the laminated type in which the above-mentioned outermost layer is provided with the charge transport layer.

[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, the diphenoquinones generally have poor compatibility with the binder resin and are not dispersed uniformly, so that the hopping distance of electrons becomes long and the electron transfer does not easily occur especially in a low electric field. Therefore, the diphenoquinones themselves have a high carrier mobility, but when they are used as an electron transfer agent in a photoconductor, the characteristics are not sufficiently exhibited, and the residual potential of the photoconductor becomes high, The photosensitivity was insufficient.

Further, as described above, most of the organic photoconductors currently in practical use are provided with a laminated type photosensitive layer, but in comparison with this, a photoconductor provided with a single layer type photosensitive layer. Is easy to manufacture, and has many advantages in that it prevents the occurrence of film defects and improves the optical characteristics. Moreover, in the photoconductor provided with such a single-layer type photoconductive layer, one photoconductor can be used as both the positive charging type and the negative charging type by using the electron transferring material and the hole transferring material together. The application range of the photoconductor may be expanded, but the diphenoquinones are
Since there is a problem that the transport of electrons and holes is hindered by the interaction with the hole-transporting agent, a photoreceptor provided with such a single-layer type photosensitive layer has not been widely put into practical use.

The object of the present invention is to provide a completely novel tryptoanthrin derivative suitable as an electron transporting agent capable of solving the above technical problems, and an electrophotographic photosensitive material using the same, which has a higher sensitivity than conventional ones. To provide the body.

[0008]

Means for Solving the Problems To solve the above problems, the tryptoanthrin derivative of the present invention has the general formula (1):
:

[0009]

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[Wherein R ^1A , R ^1B , R ^1C , R ^1D , R ^2A ,
One of R ^2B , R ^2C and R ^2D represents a cyano group,
The remaining groups are the same or different and represent a hydrogen atom or an alkyl group. ] It is characterized by being represented by. The electrophotographic photoreceptor of the present invention has the above general formula on a conductive substrate.
A photosensitive layer containing a tryptoanthrin derivative represented by (1) is provided.

Further, the photosensitive layer has an oxidation-reduction potential of −0.
It also preferably contains an electron-accepting compound of 8 to -1.4V. Such a tryptoanthrin derivative of the present invention is excellent in electron accepting property due to the action of the cyano group substituted on the tryptoanthrin ring, and at the same time, due to the action of the cyano group, solubility in a solvent and formation of a binder resin Good compatibility. Therefore, the tryptoanthrin derivative of the present invention is excellent in matching with the charge generating agent (pigment), the electron is smoothly injected from the charge generating agent, and the electron is uniformly dispersed in the photosensitive layer. Has a short hopping distance and has an excellent electron transporting property especially in a low electric field.

Further, since the above tryptoanthrin derivative does not cause an interaction with a hole transfer agent which hinders the transport of electrons and holes, it is a single layer type in which the hole transfer agent is contained in the same layer. When it is used for the photosensitive layer of No. 1, a photosensitive member having higher sensitivity can be constructed. And the electrophotographic photosensitive member of the present invention,
As described above, the photosensitive layer containing the tryptoanthrin derivative of the present invention as an electron transfer agent, which has excellent properties, has high sensitivity.

When an electron-accepting compound having a redox potential of -0.8 to -1.4 V is used in combination with the tryptoanthrin derivative, the electron-accepting compound extracts an electron from the charge generating agent to give tryptoanthane. Since it acts to transfer to the trin derivative, the injection of electrons from the charge generating agent to the tryptoanthrin derivative becomes smoother, and the sensitivity of the photoreceptor is further improved.

Furthermore, the tryptoanthrin derivative of the present invention can be used for applications such as solar cells and organic electroluminescence devices by utilizing its high electron transporting ability.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below. First, the tryptoanthrin derivative of the present invention will be described. Only one cyano group in the general formula (1) is substituted on any one of the 6-membered rings at both ends of the tryptoanthrin ring. Both of the 6-membered rings each have a cyano group substituted with a cyano group, or one of the 6-membered rings has a substituted two or more cyano groups, both of which have solubility and binding properties in a solvent. In the present invention, the substitution position of the cyano group is limited to either one of the 6-membered rings at both ends of the tryptoanthrin ring, and the number of substitutions thereof is limited to one, since the compatibility with the resin deteriorates. .

Examples of the alkyl group corresponding to the groups R ^{1A to} R ^2D in the above general formula (1) include methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, secondary butyl and tertiary. Examples thereof include alkyl groups having 1 to 6 carbon atoms such as butyl, pentyl and hexyl. The alkyl group may not be substituted, and when it is substituted, it may be substituted on either or both of the 6-membered rings at both ends of the tryptoanthrin ring.

The tryptoanthrin derivative substituted with an alkyl group is more excellent in solubility in a solvent and compatibility with a binder resin, as compared with a derivative in which an alkyl group is not substituted. Among the tryptoanthrin derivatives of the present invention represented by the general formula (1), for example, to synthesize a compound in which the group R ^2C is a cyano group, first the general formula (1a ) Isatoic anhydride derivative represented by the general formula (1b) and a bromide isatin derivative represented by the general formula (1b) by reacting in a suitable solvent, the general formula (1c) tryptic A bromide of a toanthrin derivative is synthesized.

[0018]

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[Wherein R ^1A , R ^1B , R ^1C , R ^1D , R ^2A ,
R ^2B and R ^2D are the same or different and each represents a hydrogen atom or an alkyl group. And this bromide, in a suitable solvent, for example, by reacting with copper cyanide, by substituting a cyano group for bromine, among the tryptoanthrin derivatives of the present invention represented by the general formula (1) , A compound in which the group R ^2C is a cyano group is synthesized.

The triad of the present invention represented by the general formula (1)
Of the puttoanthrin derivatives, the group R ^2COther than R^2A,
R^2BAnd R^2DA compound in which any of the above is a cyano group
To achieve this, a derivative of isatin represented by the general formula (1b)
In place of the bromide, the above group R ^2A, R^2BAnd R^2DOut of
Use a bromide of an isatin derivative, either of which is bromine.
Then, the reaction may be performed in the same manner as described above.

In addition, the triad of the present invention represented by the general formula (1)
Of the puttoanthrin derivatives, the group R ^1A, R^1B, R^1CAnd
And R^1DTo synthesize a compound in which any of the above is a cyano group
Is a bromine-substituted ether at the corresponding position in each of the above groups.
Bromides of tonic anhydride derivatives and non-brominated esters
React as above using a derivative of satin
I just need.

Specific examples of the above-mentioned tryptoanthrin derivative of the present invention include, but are not limited to, compounds represented by the formula (1-1).

[0023]

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Next, the electrophotographic photoreceptor of the present invention will be described. In the electrophotographic photoreceptor of the present invention, a photosensitive layer containing one or more of the tryptoanthrin derivatives of the present invention represented by the general formula (1) as an electron transfer agent is provided on a conductive substrate. It is a thing. The photosensitive layer includes a single layer type and a laminated type as described above.

The single-layer type photosensitive layer comprises, in a binder resin, the tryptoanthrin derivative (1) of the present invention which is an electron transfer agent,
A photoreceptor containing a hole-transporting material and a charge-generating agent and provided with this single-layer type photosensitive layer can be used in either positive or negative charging type, but the above-mentioned negative polarity corona discharge is used. It is preferable to use a positive charging type which is unnecessary. The laminated photosensitive layer is composed of a charge generating layer containing a charge generating agent and a charge transporting layer containing the tryptoanthrin derivative (1) of the present invention which is an electron transferring material. The photosensitive member can be constituted by either positive or negative charging type depending on the stacking order of both layers, but for the same reason, it is preferable to adopt the positive charging type structure in which the charge transport layer is disposed as the outermost layer.

The constitution of the present invention can be applied to both the above-mentioned single layer type and laminated type, but the single layer type is particularly preferable.
In the case of a photoreceptor having a positive charging type single-layer type photosensitive layer, the electron (−) released from the charge generating agent in the exposure process is smoothly injected into the tryptoanthrin derivative (1), and then the tryptoanthrin derivative. By transferring between the derivatives (1), they are transported to the surface of the photosensitive layer and cancel the positive charge (+) charged on the surface of the photosensitive layer in advance.

On the other hand, the positive holes (+) are injected into the positive hole transfer material and are transferred to the conductive base material by the transfer between the positive hole transfer material, and the negative charge (-) applied to the conductive base material in advance. Canceled. During this time, tryptoanthrin derivative
Since (1) and the hole transfer agent do not interact with each other as described above, both holes (+) and electrons (-) are efficiently and promptly transferred without being trapped during the process. As a result, it is considered that the sensitivity of the photoconductor is improved.

In the photoreceptor of the present invention, as described above, the electron accepting compound having a redox potential of -0.8 to -1.4 V is used in combination with the tryptoanthrin derivative (1). Is preferred. The electron-accepting compound is the LUMO [Lowest Unoccupied Molecular Orbi]
tal, ground empty molecular orbital) has a lower energy level than that of the charge generating agent, and therefore, when the electron-hole pair is generated in the charge generating agent by light irradiation, it works to extract an electron from the charge generating agent. do. Therefore, the rate of disappearance due to the recombination of electrons and holes in the charge generation agent is reduced, and the charge generation efficiency is improved. In addition, the electron-accepting compound also has a function of efficiently transferring the electron withdrawn from the charge generating agent to the tryptoanthrin derivative which is the electron transferring agent. Therefore, in the combined system of the above two, the injection and transport of electrons from the charge generating agent are smoothly performed, and the sensitivity of the photoconductor is further improved.

The redox potential of the electron-accepting compound is limited within the above range for the following reason. That is,
An electron-accepting compound having a redox potential of higher than −0.8 V drops electrons that move while repeating trap-detrap to a level that cannot be detrapped, and causes a carrier trap, which hinders electron transport, As a result, the sensitivity of the photoconductor is reduced.

On the contrary, in the case of an electron accepting compound having a redox potential of less than -1.4 V, the LUMO energy level becomes higher than that of the charge generating agent, and when the electron-hole pair is generated, Since the electron does not transfer to the electron-accepting compound,
This does not lead to an improvement in charge generation efficiency, but also reduces the sensitivity of the photoconductor. The redox potential of the electron-accepting compound is preferably −0.85 to −1.00 V, even within the above range, in consideration of the sensitivity of the photoconductor.

The oxidation-reduction potential is measured, for example, by using the following materials by a three-electrode type 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 0.1 Molar substance to be measured: electron transfer agent 0.001 mol Solvent: CH ₂ Cl ₂ 1 liter The above materials are prepared 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 it is a compound whose redox potential is within the range of -0.8 to -1.4 V, and for example, benzoquinone compound; naphthoquinone compound; anthraquinone compound; diphenoquinone compound; malononitrile compound; 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 (2):

[0034]

[Chemical 6]

[Wherein R ^3A , R ^3B , R ^3C and R ^3D 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. Is an amino group. ] A benzoquinone compound represented by the general formula (3):

[0036]

[Chemical 7]

[Wherein R ^4A , R ^4B , R ^4C and R ^4D 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. Is an amino group. ] A compound belonging to the diphenoquinone compound represented by the above formula and having an oxidation-reduction potential within the above range is preferably used.

Examples of the alkyl group in the above formula include the same groups as described above. The aralkyl group includes, for example, a benzyl group, a benzhydryl group, a trityl group and a phenethyl group, and the alkoxy group includes, for example, a methoxy group, an ethoxy group, a propoxy group, a t-butoxy group, a pentyloxy group and a hexyloxy group. Examples thereof include alkoxy groups 1 to 6, and examples of the aryl group include phenyl group and naphthyl group. Furthermore, examples of the cycloalkyl group include cycloalkyl groups having 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. Further, examples of the amino group which may have a substituent include an amino group, and also a monomethylamino, dimethylamino, monoethylamino, diethylamino group and the like.

Specific examples of the benzoquinone compound include:
For example, but not limited to, p represented by the formula (2-1)
-Benzoquinone (oxidation-reduction potential -0.81 V) and formula (2
-2) represented by 2,6-di-t-butyl-p-benzoquinone (oxidation-reduction potential-1.31 V) and the like.

[0040]

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

[0042]

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

[0044]

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(Where R⁸, R⁹, R^Ten, R¹¹, R¹²Oh
And R¹³Are the same or different and are hydrogen atom,
Child, an alkyl group which may have a substituent, and a substituent
An optionally substituted alkoxy group or an aryl group which may have a substituent
Represents a radical. a and b are the same or different and are 1 to 4
Represents an integer, and c, d, e and f are the same or different
Shows an integer of 1 to 5. In addition, a, b, c, d, e or
When f is 2 or more, each R ⁸, R⁹, R^Ten, R¹¹, R¹²Oh
And R¹³May be different. )

[0046]

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(Wherein R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R
¹⁸ is the same or different and represents a hydrogen atom, a halogen atom, 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. g, h, i and j are the same or different and are 1 to 5
Is shown, k shows the integer of 1-4. Note that g,
When h, i, j or k is 2 or more, each R ¹⁴ , R ¹⁵ , R
¹⁶ , R ¹⁷ and R ¹⁸ may be different. )

[0048]

[Chemical 12]

(In the formula, R ¹⁹ , R ²⁰ , R ²¹ and R ²² are the same or different and each is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent or an alkoxy which may have a substituent. A group or an aryl group which may have a substituent is shown.
R ²³ is a hydrogen atom, a halogen atom, a cyano group, a nitro group,
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. m, n, o and p are the same or different and are 1
Represents an integer of from 5 to 5. q shows the integer of 1-6. In addition,
When m, n, o, p or q is 2 or more, each R ¹⁹ ,
R ²⁰ , R ²¹ , R ²² and R ²³ may be different. )

[0050]

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(In the formula, R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ are the same or different and each is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent or an alkoxy which may have a substituent. A group or an aryl group which may have a substituent is shown.
r, s, t and u are the same or different and each represents an integer of 1 to 5. When r, s, t or u is 2 or more,
Each R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ may be different. )

[0052]

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(In the formula, R ²⁸ and R ²⁹ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. R ³⁰ , R ³¹ , R ³² and R ³³ are the same or different and are hydrogen. Indicates an atom, an alkyl group or an aryl group.)

[0054]

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(In the formula, R ³⁴ , R ³⁵ and R ³⁶ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0056]

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(In the formula, R ³⁷ , R ³⁸ , R ³⁹ and R ⁴⁰ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0058]

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(Wherein R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ and R
⁴⁵ is the same or different and represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. )

[0060]

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(In the formula, R ⁴⁶ represents a hydrogen atom or an alkyl group, R ⁴⁷ , R ⁴⁸ and R ⁴⁹ are the same or different,
A hydrogen atom, a halogen atom, an alkyl group or an alkoxy group is shown. )

[0062]

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(In the formula, R ⁵⁰ , R ⁵¹ and R ⁵² are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

[0064]

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(In the formula, R ⁵³ and R ⁵⁴ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent or an alkoxy group which may have a substituent ^. And R ⁵⁶ is the same or different and represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent.)

[0066]

[Chemical 21]

(In the formula, R ⁵⁷ , R ⁵⁸ , R ⁵⁹ , R ⁶⁰ , R ⁶¹ and R ⁶² are the same or different and each has a hydrogen atom, an alkyl group which may have a substituent or a substituent. Is an alkoxy group or an aryl group which may have a substituent.
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. Note that v,
When w, x, y, z or β is 2, each R ⁵⁷ , R ⁵⁸ , R
⁵⁹ , R ⁶⁰ , R ⁶¹ and R ⁶² may be different. )

[0068]

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(In the formula, R ⁶³ , R ⁶⁴ , R ⁶⁵ and R ⁶⁶ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and Ar is

[0070]

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

Substituents that may be substituted on the above groups include
For example, halogen atom, amino group, hydroxyl group, optionally esterified carboxyl group, cyano group, carbon number 1 to
Examples thereof include an alkyl group having 6 carbon atoms, 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. Further, the substitution position of the substituent is not particularly limited.

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

In the present invention, the charge transport agent is used alone or in combination of two or more. Further, when using a charge transport material having film-forming properties such as polyvinylcarbazole, the binder resin is not always necessary. In the present invention, among the hole transport materials, the ionization potential (Ip) is 4.8 to.
It is preferable to use the one of 5.6 eV and the electric field strength of 3
It is more preferable that the mobility is 1 × 10 ⁻⁶ cm ² / V · sec or more at × 10 ⁵ V / cm.

By using a hole transfer material having an ionization potential within the above range, the residual potential is further lowered,
The sensitivity is improved. The reason is not clear, but 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 transfer material and an electron transfer material coexist, it is necessary to pay attention to the interaction between them and more specifically to the formation of a charge transfer complex. When such a complex is formed between the two, recombination occurs between the holes and the electrons, and the mobility of the charge is lowered as a whole. 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 transfer agent that can be used in the present invention include compounds represented by the formula (7-1):

[0077]

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

[0079]

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(CG2) titanyl phthalocyanine

[0081]

[Chemical formula 26]

(CG3) Perylene pigment

[0083]

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(In the formula, R ⁷⁰ and R ⁷¹ are the same or different and each represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkanoyl group or aralkyl group having 18 or less carbon atoms.) (CG4 ) Bisazo pigment

[0085]

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[In the formula, A ¹ and A ² are the same or different and each represents a coupler residue, and X is

[0087]

[Chemical 29]

(In the formula, R ⁷² represents a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and the alkyl group, the aryl group or the heterocyclic group may have a substituent.
Represents 0 or 1. )

[0089]

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[0090]

[Chemical 31]

(In the formula, R ⁷³ and R ⁷⁴ are the same or different and each represents 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.)

[0092]

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[0093]

[Chemical 33]

[0094]

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(In the formula, R ⁷⁵ represents a hydrogen atom, an ethyl group, a chloroethyl group or a hydroxyethyl group.)

[0096]

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Or

[0098]

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(Wherein R ⁷⁶ , R ⁷⁷ and R ⁷⁸ are the same or different and 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

[0100]

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(In the formula, R ⁷⁹ and R ⁸⁰ are the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ⁸¹ and R ⁸² are the same or different and are a hydrogen atom, an alkyl group or an aryl group. (CG6) Metal-free naphthalocyanine pigment

[0102]

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(In the formula, R ⁸³ , R ⁸⁴ , R ⁸⁵ and R ⁸⁶ are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.) (CG7) Metal naphthalocyanine pigment

[0104]

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(In the formula, R ⁸⁷ , R ⁸⁸ , R ⁸⁹ and R ⁹⁰ are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and M represents Ti or V.) (CG8) Squaraine pigment

[0106]

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(In the formula, R ⁹¹ and R ⁹² are the same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom.) (CG9) Trisazo pigment

[0108]

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

[0110]

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(In the formula, R ⁹³ and R ⁹⁴ are the same or different and each represents a hydrogen atom, an alkyl group or an aryl group,
Z represents an oxygen atom or a sulfur atom. ) (CG11) Azurenium pigment

[0112]

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(In the formula, R ⁹⁵ and R ⁹⁶ are the same or different and each represents a hydrogen atom, an alkyl group or an aryl group.) (CG12) Cyanine pigment

[0114]

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(Wherein R ⁹⁷ and R ⁹⁸ are the same or different and represent a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom, and R ⁹⁹ and R ¹⁰⁰ are the same or different and are a hydrogen atom, an alkyl group or an aryl group. In the above-mentioned charge generating agent, the alkyl group is
The same groups as described above can be mentioned. The alkyl group having 1 to 5 carbon atoms is the above-mentioned alkyl group having 1 to 6 carbon atoms with hexyl removed. 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-mentioned 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, aryl group and aralkyl group include the same groups as described above. Examples of the alkanoyl group include a formyl group, an acetyl group, a propionyl group, a butyryl group, a pentanoyl group and a hexanoyl group.

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

Substituents that may be substituted on the above groups include
For example, a halogen atom, an amino group, a hydroxyl group, a carboxyl group which may be esterified, a cyano group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms which may have an aryl group And 6 alkenyl groups. Examples of the coupler residue represented by A ¹ , A ² and Cp ₁ , Cp ₂ , Cp ₃ include those represented by the following general formula (2
The groups shown in 1) to (27) are mentioned.

[0118]

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In each formula, R ¹²⁰ 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 ¹²¹ represents an atomic group necessary for being condensed with a benzene ring to form an aromatic ring, a polycyclic hydrocarbon or a heterocycle, and these rings have a substituent similar to the above. May be. R ¹²² represents an oxygen atom, a sulfur atom or an imino group. R ¹²³ represents a divalent chain hydrocarbon group or an aromatic hydrocarbon group, and these groups may have the same substituents as described above.

R ¹²⁴ represents an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, and these groups may have the same substituents as described above. R ¹²⁵ is a divalent chain hydrocarbon group, an aromatic hydrocarbon group or the above general formula (25), (26)
In the following formula (28):

[0122]

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It represents an atomic group necessary for forming a heterocycle together with the moiety represented by, and these rings may have the same substituents as described above. R ¹²⁶ represents a hydrogen atom, an alkyl group, an amino group, a carbamoyl group, a sulfamoyl group, an allofanoyl group, a carboxyl group, an alkoxycarbonyl group, an aryl group or a cyano group, and groups other than the hydrogen atom have the same substituents as described above. You may have.

R ¹²⁷ 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-pentenyl and 2-hexenyl alkenyl groups having 2 to 6 carbon atoms. .

Examples of the atomic group necessary for forming an aromatic ring by condensing with the benzene ring in R ¹²¹ above include alkylene groups such as methylene group, ethylene group, propylene group and butylene group. Examples of the aromatic ring formed by the condensation of R ¹²¹ and the benzene ring include naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, and naphthacene ring.

In the above R ¹²¹ , the atomic group necessary for condensation with a benzene ring to form a polycyclic hydrocarbon is, for example, a methylene group, an ethylene group, a propylene group or a butylene group having 1 to 4 carbon atoms. The alkylene group of Examples of the atomic group necessary for forming a polycyclic hydrocarbon by condensing with the benzene ring in R ¹²¹ include a carbazole ring, a benzocarbazole ring, a dibenzofuran ring, and the like.

Further, in R ¹²¹ , the atomic group necessary for condensing with the benzene ring to form a heterocycle is, for example, a benzofuranyl group, a benzothiophenyl group, an indolyl group, a 1H-indolyl group, a benzoxazolyl group. Group, benzothiazolyl group, 1H-indaryl group, benzimidazolyl group, chromenyl group, chromanyl group, isochromanyl group, quinolinyl group, isoquinolinyl group, cinnolinyl group, phthalazinyl group, quinazonilyl group, quinoxalinyl group, dibenzofuranyl group, carbazolyl group, xanthenyl group , An acridinyl group, a phenanthridinyl group, a phenazinyl group, a phenoxazinyl group and a thianthrenyl group.

Examples of the aromatic heterocyclic group formed by condensation of R ¹²¹ and the benzene ring include, for example, thienyl group, furyl group, pyrrolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, Examples thereof include a pyrazolyl group, a triazolyl group, a tetrazolyl group, a pyridyl group and a thiazolyl group. Also,
Further, it may be a heterocyclic group condensed with another aromatic ring (for example, a benzofuranyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a quinolyl group, etc.).

In R ¹²³ and R ¹²⁵ , examples of the divalent chain hydrocarbon include ethylene group, propylene group and butylene group, and examples of the divalent aromatic hydrocarbon include phenylene group, naphthylene group, Examples thereof include a phenanthrylene group. ^Examples of the heterocyclic group for R ¹²⁴ include a pyridyl group, a pyrazyl group, a thienyl group, a pyranyl group and an indolyl group.

In R ¹²⁵ , the atomic group necessary for forming a heterocycle with the moiety represented by the formula (28) is, for example, phenylene group, naphthylene group, phenanthrylene group, ethylene group, propylene group, butylene. Groups and the like. Examples of the aromatic heterocyclic group formed by R ¹²⁵ and the moiety represented by the formula (28) include a benzimidazole group, a benzo [f] benzimidazole group, a dibenzo [e, g] benzimidazole group. Group, benzopyrimidine group and the like. These groups may have the same substituents as described above.

Examples of the alkoxycarbonyl group for R ¹²⁶ include groups such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group and a butoxycarbonyl group. In the present invention, in addition to the charge generators exemplified above, for example, selenium, selenium-tellurium, amorphous silicon, pyrylium salts, ansanthuron pigments, triphenylmethane pigments, slene pigments, toluidine pigments, pyrazoline pigments. Conventionally known charge generating agents such as quinacridone pigments can be used.

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

As a particularly preferable charge generating agent, an X-type metal-free phthalocyanine represented by the above general formula (CG1), a general formula
Examples thereof include phthalocyanine pigments such as oxotitanyl phthalocyanine represented by (CG2) and perylene pigments represented by the general formula (CG3). As the perylene pigment,
Among the above-mentioned perylene pigments of general formula (CG3), especially general formula (11):

[0134]

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(Wherein R ¹³⁰ , R ¹³¹ , R ¹³² and R
¹³³ is the same or different and represents a hydrogen atom, an alkyl group, an alkoxyl group or an aryl group. The compound represented by) is preferably used. In the general formula (11), examples of the alkyl group, alkoxy group and aryl group corresponding to the substituents R ^{130 to} R ¹³³ include the same groups as described above.

The phthalocyanine pigment has a thickness of 700 nm.
It is suitable as a charge generating material for a photoreceptor having sensitivity in the above wavelength range. That is, since the phthalocyanine pigment is excellent in matching with the compound (electron transfer agent) represented by the general formula (1), an electrophotographic photoreceptor using both of them has high sensitivity in the above wavelength range, and 70
It can be suitably used for an image forming apparatus of a digital optical system using a light source having a wavelength of 0 nm or more.

Further, the perylene-based pigment is suitable as a charge generating material for a photoreceptor having sensitivity in the visible region. That is, in particular, the perylene pigment (11) is excellent in matching with the compound (electron transfer agent) represented by the general formula (1),
The electrophotographic photosensitive member using both of them has high sensitivity in the visible region, and therefore can be suitably used for an analog optical 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. 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 , Thermoplastic resins such as polyurethane, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, polyester resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, etc. Examples thereof include crosslinkable thermosetting resins, and photocurable resins such as epoxy acrylate and urethane-acrylate. 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 manufacturing 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 thickness of the single-layer type photosensitive layer is 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 laminated 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
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 that does not hinder the transport of charge and a range that does not crystallize. In order to easily transport the generated charge, 10 to 10 parts by weight of the electron transfer agent is added to 100 parts by weight of the binder resin.
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 multi-layer type photosensitive layers contains various additives known per se, such as an antioxidant, a radical scavenger, a singlet quencher, within a range that does not adversely affect the electrophotographic characteristics. A deterioration inhibitor such as an ultraviolet absorber, a softening agent, a plasticizer, a surface modifier, a bulking agent, a thickener, a dispersion stabilizer, a wax, an acceptor, a donor 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 to the tryptoanthrin derivative which is an electron transfer agent, other conventionally known electron transfer agents may be contained in the photosensitive layer. Examples of such an electron transfer agent include various compounds having a high electron transport ability, for example, a benzoquinone compound of the general formula (2) and a diphenoquinone compound of the general formula (3), and the following general formula (ET1 ) To (ET13) and the like.

[0145]

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(In the formula, R ¹⁴² , R ¹⁴³ , R ¹⁴⁴ , and R ¹⁴⁵
And R ¹⁴⁶ are the same or different and each have a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, and a substituent. Represents an optionally substituted aralkyl group, an optionally substituted phenoxy group or a halogen atom. )

[0147]

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(In the formula, R ¹⁴⁷ is an alkyl group, R ¹⁴⁸ 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, a substituent Represents an aralkyl group which may have a group, a halogen atom or a halogenated alkyl group, and γ represents an integer of 0 to 5.
When γ is 2 or more, each R ¹⁴⁸ may be different from each other. )

[0149]

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(In the formula, R ¹⁴⁹ and R ¹⁵⁰ are the same or different and each represents an alkyl group. Δ represents an integer of 1 to 4 and ε represents an integer of 0 to 4. Note that δ and ε are 2). In the above case, each R ¹⁴⁹ and R ¹⁵⁰ may be different.)

[0151]

[Chemical 51]

(In the formula, R ¹⁵¹ represents an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a halogenated alkyl group or a halogen atom. Ζ is 0 to 4 and η is 0 to 5
Is an integer. When η is 2 or more, each R ¹⁵¹ may be different. )

[0153]

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(In the formula, R ¹⁵² represents an alkyl group, and σ is an integer of 1 to 4. When σ is 2 or more, each R is
¹⁵² may be different. )

[0155]

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(In the formula, R ¹⁵³ and R ¹⁵⁴ are the same or different and each represents 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. Basis:
Indicates O, N-CN or C (CN) ₂ . )

[0157]

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(In the formula, R ¹⁵⁵ represents a hydrogen atom, a halogen atom, an alkyl group or a phenyl group which may have a substituent, and R ¹⁵⁶ represents a hydrogen atom, a halogen atom or 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 shown.
Is an integer of 1 to 3. When λ is 2 or more, each R
¹⁵⁶ may be different from each other. )

[0159]

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(In the formula, R ¹⁵⁷ is a hydrogen atom, an alkyl group which may have a substituent, a phenyl group which may have a substituent, a halogen atom, an alkoxycarbonyl group, N
-Indicates an alkylcarbamoyl group, a cyano group or a nitro group. μ is an integer of 1 to 3. When μ is 2 or more, each R ¹⁵⁷ may be different from each other. )

[0161]

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(In the formula, R ¹⁵⁸ and R ¹⁵⁹ are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, a cyano group, a nitro group or an alkoxycarbonyl group. Ν and ξ are It is an integer of 1 to 3. When ν or ξ is 2 or more, each R ¹⁵⁸ and R ¹⁵⁹ may be different from each other.)

[0163]

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(In the formula, R ¹⁶⁰ and R ¹⁶¹ 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.)

[0165]

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(In the formula, R ¹⁶² represents an amino group, a dialkylamino group, an alkoxy group, an alkyl group or a phenyl group, and π is an integer of 1 to 2. When π is 2,
Each R ^{16 2} may be different from each other. )

[0167]

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(In the formula, R ¹⁶³ represents a hydrogen atom, an alkyl group,
It represents an aryl group, an alkoxy group or an aralkyl group. )

[0169]

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(Wherein, θ is an integer of 1 to 2), and the like. Further, malononitrile, a thiopyran compound, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, Dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride,
Examples include dibromomaleic anhydride.

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

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

As the substituent which may be substituted on the above group,
For example, a halogen atom, an amino group, a hydroxyl group, a carboxyl group which may be esterified, a cyano group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 2 to 2 carbon atoms which may have an aryl group And 6 alkenyl groups. As the conductive substrate used in the photoreceptor of the present invention, various conductive materials can be used, such as aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, Titanium,
Examples include simple metals such as nickel, palladium, indium, stainless steel, and brass, plastic materials obtained by vapor deposition or laminating of the above metals, and glass coated with aluminum iodide, tin oxide, indium oxide, or 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, the above-mentioned charge generating agent, charge transporting agent, binder resin and the like are used together with an appropriate solvent by a known method such as roll mill, ball mill, attritor, paint shaker or ultrasonic disperser. The coating liquid may be prepared by dispersing and mixing, and the coating liquid may be coated and dried by a known means. As a solvent for preparing the coating liquid, various organic solvents can be used, for example, alcohols such as methanol, ethanol, isopropanol and butanol, n-hexane, octane, aliphatic hydrocarbons such as cyclohexane, benzene, 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 transport material or the charge generating material and the smoothness of the surface of the photosensitive layer, a surface active agent, a leveling agent, etc. may be used.

[0177]

EXAMPLES The present invention will be described below based on synthesis examples, examples and comparative examples. << Tryptoanthrin Derivative >> Synthesis Example 1 [Synthesis of 6-cyanotryptoanthrin] Formula (1a-1):

[0178]

[Chemical formula 61]

1.0 g of isatoic anhydride represented by (4.
1 mmol) and the formula (1b-1):

[0180]

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1.0 g of 5-bromoisatin represented by
(4.4 mmol) and 20 ml of pyridine were put into a 200 ml eggplant-shaped flask, and the mixture was heated under reflux for 6 hours for reaction, and then the solid precipitated in the cooled reaction solution was filtered off to obtain the compound of the formula (1c-1):

[0182]

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0.40 g (yield 31.0%) of 6-bromotryptoanthrin represented by the following formula was obtained. Next, this 6-
Bromotryptanthrin 1.5 g (4.5 mmol)
Together with 0.64 g (7.2 mmol) of copper cyanide and 10 ml of N-methylpyrrolidone, 100 ml of
The mixture was placed in a round bottom flask and heated under reflux for 4 hours for reaction.

Next, the reaction solution after the reaction was poured into ice and the precipitated solid was separated by filtration. The filtered solid was added to 20% aqueous ammonia, and extracted with chloroform. Then, the organic phase obtained by liquid separation was washed with water, neutralized, dried over anhydrous magnesium sulfate, and then the solvent was distilled off to obtain crystals.
Further purification by silica gel chromatography gave 0.76 g (yield 62.0%) of the title compound represented by the formula (1-1).

The results of elemental analysis of this product are as follows. The infrared absorption spectrum of the above product is shown in FIG. << Photoreceptor 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 formula (CG1), which is a charge generating agent, and an electron transfer agent. 30 parts by weight of 6-cyanotryptanthrine represented by the above formula (1-1) obtained in Synthesis Example 1 and N represented by the above formula (7-1) which is a hole transfer agent. , N, N ',
N'-tetrakis (p-methylphenyl) -3,3'-
50 parts by weight of dimethylbenzidine (Ip = 5.56 eV) and polycarbonate, which is a binder resin, were mixed together with 800 parts by weight of tetrahydrofuran in a ball mill at 50 parts by weight.
The coating liquid for the single-layer type photosensitive layer was prepared by mixing and dispersing for a time.

Then, this coating solution is applied onto an aluminum base tube which is a conductive base material by a dip coating method, and 1
Dry with hot air at 00 ° C for 60 minutes to obtain a film thickness of 15 to 20μ.
A single-layer type photosensitive layer of m was formed to produce a photoreceptor for a digital light source. Example 2 Example 1 was repeated except that 5 parts by weight of oxotitanyl phthalocyanine (Ip = 5.32 eV) represented by the formula (CG2) was used in place of the X-type metal-free phthalocyanine as the charge generating agent. Similarly, a photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured. Comparative Example 1 Instead of 6-cyanotryptoanthrine as an electron transfer agent, 3,5-dimethyl-type represented by the formula (3-1)
A photoconductor for a digital light source having a single-layer type photosensitive layer was produced in the same manner as in Example 1 except that 30 parts by weight of 3 ', 5'-di-t-butyl-4,4'-diphenoquinone was used. did. Comparative Example 2 A photoconductor for a digital light source having a single-layer type photosensitive layer in the same manner as in Comparative Example 1 except that 5 parts by weight of oxotitanyl phthalocyanine was used instead of the X-type metal-free phthalocyanine as the charge generating agent. Was manufactured. Comparative Example 3 In the same manner as in Example 1 except that the electron transfer agent was not contained,
A photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured.

The following photosensitivity test I was carried out on the electrophotographic photoreceptors of the above-mentioned respective Examples and Comparative Examples to evaluate their characteristics. Photosensitivity test I Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the electrophotographic photoreceptors of Examples and Comparative Examples to charge the surface thereof to + 700V.

Then, monochromatic light having a wavelength of 780 nm (half-value width of 20 nm) and a light intensity of 16 μW / cm ² extracted from a white light of a halogen lamp which is an exposure light source of the above-mentioned tester by a bandpass filter is charged in the charged state. The surface of the photoconductor is irradiated (irradiation time 80 msec.), 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.

The results are shown in Table 1.

[0190]

[Table 1]

<< Photoreceptor for Digital Light Source (Single Layer Type-Electron-Accepting Compound Combination System) >> Example 3 An electron-accepting compound represented by the formula (2-1), p-
A photoreceptor for a digital light source having a single-layer type photosensitive layer was produced in the same manner as in Example 1 except that 10 parts by weight of benzoquinone (oxidation-reduction potential -0.81 V) was added. Example 4 Instead of p-benzoquinone as an electron accepting compound,
In the same manner as in Example 3 except that 10 parts by weight of 2,6-di-t-butyl-p-benzoquinone (redox potential-1.31 V) represented by the formula (2-2) was added, A photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured. Example 5 Instead of p-benzoquinone as an electron accepting compound,
3,5-dimethyl-3 ', 5' represented by the formula (3-1)
-Di-t-butyl-4,4'-diphenoquinone (redox potential -0.86 V) except that 10 parts by weight were added.
In the same manner as in Example 3, a photoreceptor having a single-layer type photosensitive layer for a digital light source was manufactured. Example 6 Instead of p-benzoquinone as an electron accepting compound,
10 parts by weight of 3,5,3 ', 5'-tetrakis (t-butyl) -4,4'-diphenoquinone (oxidation-reduction potential -0.94 V) represented by the formula (3-2) was added. A photoreceptor for a digital light source having a single-layer type photosensitive layer was manufactured in the same manner as in Example 3 except for the above.

Regarding the electrophotographic photoreceptors of the above respective examples,
The above photosensitivity test I was performed to evaluate the characteristics. Table 2 shows the results.

[0193]

[Table 2]

<< Photoreceptor for Digital Light Source (Layered Type) >> Example 7 100 parts by weight of X-type metal-free phthalocyanine, which is a charge generating agent, and 100 parts by weight of polyvinyl butyral, which is a binder resin, are added in 2000 parts by weight of tetrahydrofuran. At the same time, they were mixed and dispersed in a ball mill for 50 hours to prepare a coating liquid for the charge generation layer.

Then, this coating solution is applied onto an aluminum base tube which is a conductive base material by a dip coating method, and 1
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, 800 parts by weight of 100 parts by weight of 6-cyanotryptanthrin represented by the above formula (1-1), which is an electron transfer agent, obtained in Synthesis Example 1 and 100 parts by weight of a polycarbonate which is a binder resin are added. A coating solution for the charge transport layer was prepared by mixing and dispersing 50 parts by weight of toluene in a ball mill for 50 hours.

Then, this coating solution was applied onto the charge generation layer by a dip coating method and dried with hot air at 100 ° C. for 60 minutes to form a charge transport layer having a film thickness of 20 μm. A photoreceptor for a digital light source having a layer was manufactured. Comparative Example 4 Instead of 6-cyanotryptoanthrin as an electron transfer agent, 3,5-dimethyl-type represented by the formula (3-1)
In the same manner as in Example 7 except that 100 parts by weight of 3 ', 5'-di-t-butyl-4,4'-diphenoquinone was used, a photoreceptor for a digital light source having a laminated photosensitive layer was produced. .

The above-mentioned photosensitivity test I was carried out on the electrophotographic photosensitive members of the above Examples and Comparative Examples, and the characteristics thereof were evaluated. The results are shown in Table 3.

[0198]

[Table 3]

<< Photoreceptor for Analog Light Source (Single Layer Type) >> Example 8 Instead of the X-type metal-free phthalocyanine as the charge generating agent, a compound represented by the formula (11-
1):

[0200]

Embedded image

Compound represented by (Ip = 5.50 eV)
A photoreceptor for an analog light source having a single-layer type photosensitive layer was produced in the same manner as in Example 1 except that 5 parts by weight was used. Comparative Example 5 Instead of 6-cyanotryptoanthrin as the electron transfer agent, 3,5-dimethyl-type represented by the formula (3-1)
A photoreceptor for an analog light source having a laminated photosensitive layer was produced in the same manner as in Example 8 except that 30 parts by weight of 3 ', 5'-di-t-butyl-4,4'-diphenoquinone was used. . Comparative Example 6 In the same manner as in Example 8 except that the electron transfer agent was not included,
A photoreceptor for an analog light source having a single-layer type photosensitive layer was manufactured.

The following photosensitivity test II was carried out on the electrophotographic photosensitive members of the above Examples and Comparative Examples to evaluate their characteristics. Light Sensitivity Test II Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the electrophotographic photosensitive members of Examples and Comparative Examples to charge the surfaces thereof to +700 V.

Then, the white light (light intensity 147 μW / cm ² ) of the halogen lamp which is the exposure light source of the above 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.

The results are shown in Table 4.

[0205]

[Table 4]

<< Photoreceptor for Analog Light Source (Layered Type) >> Example 9 As the charge generating agent, 100 parts by weight of the perylene pigment represented by the above formula (11-1) was used instead of the X-type metal-free phthalocyanine. Except for the above, a photoreceptor for an analog light source having a laminated photosensitive layer was produced in the same manner as in Example 7. Comparative Example 7 The electron transfer agent was replaced by 6-cyanotryptoanthrin, and 3,5-dimethyl-type represented by the formula (3-1)
A photoreceptor for an analog light source having a laminated photosensitive layer was produced in the same manner as in Example 9 except that 100 parts by weight of 3 ', 5'-di-t-butyl-4,4'-diphenoquinone was used. .

The photosensitivity test II was conducted on the electrophotographic photoreceptors of the above-mentioned respective examples and comparative examples, and the characteristics were evaluated. Table 5 shows the results.

[0208]

[Table 5]

[0209]

The tryptoanthrin derivative of the present invention is
It has excellent electron-transporting ability, and has good solubility in a solvent and compatibility with a binder resin. Therefore, the electrophotographic photosensitive member using the tryptoanthrin derivative of the present invention as an electron transfer agent has high sensitivity. When the tryptoanthrin derivative is used in combination with an electron-accepting compound having a specific redox potential, the sensitivity of the photoconductor can be further improved.

[Brief description of 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 product synthesized in Synthesis Example 1 of the present invention.

Claims (3)

[Claims] 1. General formula (1): [Wherein one of R ^1A , R ^1B , R ^1C , R ^1D , R ^2A , R ^2B , R ^2C and R ^2D represents a cyano group, and the remaining groups are the same or different and each represent a hydrogen atom or Indicates an alkyl group. ] The tryptoanthrin derivative characterized by being represented by these. 2. A conductive film of the general formula (1): embedded image [Wherein one of R ^1A , R ^1B , R ^1C , R ^1D , R ^2A , R ^2B , R ^2C and R ^2D represents a cyano group, and the remaining groups are the same or different and each represent a hydrogen atom or Indicates an alkyl group. ] The electrophotographic photoreceptor which provided the photosensitive layer containing the tryptoanthrin derivative represented by these. 3. The redox potential of the photosensitive layer is -0.8 to -1.
The electrophotographic photosensitive member according to claim 2, which also contains a 4 V electron-accepting compound.