JP3445877B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the Lee Sachin induction body with <br/>, e.g. electrostatic copying machines, laser beam printers, electrophotographic used in an image forming apparatus such as a plain paper facsimile apparatus photosensitive It is about the body.

[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 classified 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 layer. Some include a laminated type photosensitive layer in which a charge transport layer containing an agent is laminated, and of these, a photoreceptor having a laminated type photosensitive layer is common. 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.

However, the photoreceptor having the above-mentioned negative charging type laminated photosensitive layer is required to be charged by negative corona discharge which generates a large amount of ozone, which may affect the environment due to ozone or the photoreceptor itself. Deterioration becomes a problem. Therefore, in order to solve such a problem, an electron transfer agent having a high carrier mobility has been developed and studied. For example, JP-A-1-206349 uses a compound having a diphenoquinone structure as an electron transfer agent. It is suggested to do so.

[0005]

However, the diphenoquinones generally have poor compatibility with the binder resin and are not uniformly dispersed, 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.

An object of the present invention, using suitable Lee satin inductive element as the electron transferring material capable of solving the technical problem described above is to provide an electrophotographic photoreceptor with high sensitivity as compared with the conventional .

[0008]

[Means for Solving the Problems] The inventors have conducted earnest research to solve the above problems. The applicant of the present invention has previously confirmed that the compound can be used as an electron transfer agent, and is a raw material for tryptoanthrin, which is a substance known as a dye intermediate, and has the formula (1a-1):

[0009]

[Chemical 3]

Attention was paid to isatin represented by: But,
Such isatin has a problem that it has insufficient durability and is easily deteriorated when used for a photoreceptor. Therefore, when I tried to replace the hydrogen atom bonded to nitrogen of isatin with an alkyl group, not only was the durability improved, but
By the action of the above alkyl group, electron acceptability is improved,
In addition, it was revealed that the solubility in the solvent and the compatibility with the binder resin are improved.

Therefore, the electrophotographic photoreceptor of the present invention has the general formula (1):

[0012]

[Chemical 4]

[In the formula, R ¹ represents an alkyl group. R ^2A ,
Any one of R ^2B , R ^2C and R ^2D represents a hydrogen atom, and the remaining groups are the same or different and represent a hydrogen atom or an alkyl group. And isatin derivative represented by]
A single-layer type photosensitive layer containing a hole transport material and a charge generation material is provided. Further, other electrophotographic feeling of the present invention
The photoconductor is a charge generation layer containing a charge generation agent on a conductive substrate.
And an electron transfer agent represented by the above general formula (1).
Laminated type photoconductor comprising charge transport layer containing satin derivative
It is characterized in that a layer is provided.

The single-layer type or laminated type photosensitive layer preferably contains an electron-accepting compound having a redox potential of -0.8 to -1.4 V. Such an isatin derivative contained in the single-layer type or laminated type photosensitive layer in the electrophotographic photosensitive member of the present invention has excellent electron accepting property as described above, and also has solubility in a solvent and a binder resin. Good compatibility. Therefore, the isatin derivative is excellent in matching with the charge generating agent (pigment), the electrons are smoothly injected from the charge generating agent, and the isatin is uniformly dispersed in the photosensitive layer, so that the hopping distance of the electron is short. Especially, it excels in electron transport property in a low electric field. In particular, it is better than the tryptoanthrin in matching with the charge generating agent.

Further, the above-mentioned isatin derivative does not cause an interaction with a hole transfer material which hinders the transport of electrons and holes, so that a single layer type photosensitive material containing the hole transfer material in the same layer is used. When used in a layer, a more sensitive photoreceptor can be constructed. The electrophotographic photosensitive member of the present invention has high sensitivity because it has a single-layer type or multi-layer type photosensitive layer containing the isatin derivative having excellent properties as described above as an electron transporting agent.

When an electron-accepting compound having a redox potential of -0.8 to -1.4 V is used in combination with the isatin derivative, the electron-accepting compound withdraws an electron from the charge generating agent and transfers it to the isatin derivative. In this way, the injection of electrons from the charge generating agent into the isatin derivative is further facilitated, and the sensitivity of the photoreceptor is further improved .

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below. Also <br/> not a will be described Lee satin derivatives. The general formula (1)
Examples of the alkyl group corresponding to the groups R ¹ and R ^{2A to} R ^2D therein include methyl, ethyl, normal propyl, isopropyl, normal butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, hexyl and the like. Carbon number 1
~ 6 alkyl groups.

Among such isatin derivatives, those having the simplest structure are those in which the group R ¹ is an alkyl group and the groups R ^2A to
R ^2D is a compound in which all hydrogen atoms are present, and this compound has excellent properties as will be apparent from the results of Examples described later, but any of the above groups R ^{2A to} R ^2D is an alkyl group. It is presumed that the isatin derivative, which is, is further improved in solubility in a solvent and compatibility with a binder resin.

[0019] To synthesize Lee Sachin derivative, as shown in the following Scheme, the general formula of isatin represented by (1a) derivative, in a suitable solvent, for example in the presence of sodium hydride, generally It may be reacted with an alkyl iodide represented by the formula (1b).

[0020]

[Chemical 5]

[In the formula, R ¹ , R ^{2A to} R ^2D are the same as defined above. ] Specific compounds of Lee Sachin derivatives include, but are not limited to, for example, a compound represented by the formula (1-1) can be mentioned.

[0022]

[Chemical 6]

Next, the electrophotographic photoreceptor of the present invention will be described. The electrophotographic photosensitive member of the present invention, a conductive substrate, in which one or more of the represented by the general formula (1) s satin derivative provided a photosensitive layer containing as an electron transporting agent. 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 Louis satin derivative (1), in which a hole transport material, was contained a charge generating agent, the single The photoconductor provided with the layer type photosensitive layer can be used for both positive and negative charging types,
It is preferable to use a positive charging type which does not require the use of the negative polarity corona discharge described above. The multi-layer type photosensitive layer comprises a charge generating layer containing a charge generating material composed of a charge transporting layer containing an electron transfer agent der Louis satin derivative (1), the photosensitive member having a photosensitive layer of the multilayer Can be configured as either a positive or negative charging type depending on the stacking order of both layers, but for the same reason, it is preferable to adopt a positive charging type configuration in which the charge transport layer is disposed as the outermost layer.

The constitution of the present invention can be applied to both the single layer type and the 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 step is smoothly injected into the isatin derivative (1), and then the isatin derivative (1) The positive and negative charges (+), which are transported to the surface of the photosensitive layer due to the transfer between them and are charged in advance on the surface of the photosensitive layer, are canceled.

On the other hand, the positive holes (+) are injected into the positive hole transfer material and are transferred to the conductive substrate by the transfer between the positive hole transfer agents, and the negative charge (-) applied to the conductive base material in advance. Canceled. During this period, the isatin derivative (1) and the hole transfer agent do not interact with each other as described above,
It is considered that the holes (+) and the electrons (-) are efficiently and promptly transported without being trapped on the way, and as a result, the sensitivity of the photoreceptor is improved.

Further, in the photoreceptor of the present invention, as described above, it is preferable to use together with the isatin derivative (1) an electron accepting compound having a redox potential of −0.8 to −1.4 V. . The electron-accepting compound has the LU
Since the energy level of MO [Lowest Unoccupied Molecular Orbital] is lower than that of the charge generating agent, the charge generating agent is generated when the electron-hole pair is generated in the charge generating agent by light irradiation. It works by pulling out electrons from. 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 transmitting the electron withdrawn from the charge generating agent to the isatin derivative which is the electron transporting 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 reason why the redox potential of the electron-accepting compound is limited within the above range is as follows. 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 redox 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 Prepare a measurement solution by mixing 1 liter or more of materials.

Then, as shown in FIG. 1, the index voltage (V)
And the current (μA) are calculated, E ₁ and E shown in the same figure are obtained.
₂ and are measured, and the redox potential is determined by the following calculation 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-
Fluorenone compounds such as 9-fluorenone; dinitroanthracene; dinitroacridine; nitroanthraquinone; compounds having an electron-accepting property such as dinitroanthraquinone; It

Among them, the general formula (2):

[0033]

[Chemical 7]

[Wherein R ^3A , R ^3B , R ^3C and R ^3D are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a substituent Represents an aryl group which may have a substituent, an aralkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an amino group which may have a substituent. ] A benzoquinone compound represented by the general formula (3):

[0035]

[Chemical 8]

[In the formula, R ^4A , R ^4B , R ^4C and R ^4D are the same or different and each is a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, a substituent Represents an aryl group which may have a substituent, an aralkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or an amino group which may have a substituent. ] 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.

The alkyl groups in the above formulas are as follows:
The same groups as mentioned above can be mentioned. 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.

[0039]

[Chemical 9]

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). .

[0041]

[Chemical 10]

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).

[0043]

[Chemical 11]

(Where R is⁸, 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
Indicates 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. )

[0045]

[Chemical 12]

(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. )

[0047]

[Chemical 13]

(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,
The alkyl group which may have a substituent, the alkoxy group which may have a substituent, or the aryl group which may have a substituent are shown. m, n, o and p are the same or different and are 1
Indicates an integer of ˜5. q represents an integer of 1 to 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. )

[0049]

[Chemical 14]

(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. )

[0051]

[Chemical 15]

(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.)

[0053]

[Chemical 16]

(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.)

[0055]

[Chemical 17]

(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.)

[0057]

[Chemical 18]

(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. )

[0059]

[Chemical 19]

(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. )

[0061]

[Chemical 20]

(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.)

[0063]

[Chemical 21]

(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.)

[0065]

[Chemical formula 22]

(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. )

[0067]

[Chemical formula 23]

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

[0069]

[Chemical formula 24]

The groups (Ar1), (Ar2) or (Ar3) represented by are shown below. ) In the above-described hole transporting agent, the alkyl group is
The same groups as mentioned above can be mentioned. As an 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 which 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 the 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 easiness of injecting charges from the charge generating agent into 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. Is considered to cause a decrease in sensitivity due to a lower degree of charge injection from the charge generating agent to the hole transfer agent or a lower degree of hole transfer between the hole transfer agents. . 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 transfer material is smaller than the above range, the tendency to form a complex with the electron transfer material increases, and electron-hole recombination occurs, resulting in an apparent quantum yield. Is likely to decrease, resulting in 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):

[0076]

[Chemical 25]

Examples thereof include benzidine derivatives 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

[0078]

[Chemical formula 26]

(CG2) Titanyl phthalocyanine

[0080]

[Chemical 27]

(CG3) Perylene pigment

[0082]

[Chemical 28]

(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

[0084]

[Chemical 29]

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

[0086]

[Chemical 30]

(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. )

[0088]

[Chemical 31]

[0089]

[Chemical 32]

(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.)

[0091]

[Chemical 33]

[0092]

[Chemical 34]

[0093]

[Chemical 35]

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

[0095]

[Chemical 36]

Or

[0097]

[Chemical 37]

(Wherein R ⁷⁶ , R ⁷⁷ and R ⁷⁸ 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). . ] (CG5) Dithioketopyrrolopyrrole pigment

[0099]

[Chemical 38]

(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

[0101]

[Chemical Formula 39]

(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

[0103]

[Chemical 40]

(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

[0105]

[Chemical 41]

(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

[0107]

[Chemical 42]

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

[0109]

[Chemical 43]

(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

[0111]

[Chemical 44]

(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

[0113]

[Chemical formula 45]

(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 mentioned 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. It may also be a heterocyclic group condensed with an aromatic ring.

Substituents which 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, or an aryl group having 2 to 2 carbon atoms. And the alkenyl group of 6 and the like. 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.

[0117]

[Chemical formula 46]

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, 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):

[0121]

[Chemical 47]

It represents an atomic group necessary for forming a heterocycle 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 the above R ¹²¹ 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 the 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, and 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 methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group and the like. In the present invention, in addition to the charge generating agents 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):

[0133]

[Chemical 48]

(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 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. For example, a styrene-based polymer and a styrene-butadiene copolymer 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, diallylphthalate 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 are 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 photosensitive member, a predetermined electron transfer agent is dissolved or dispersed in a suitable solvent together with a charge generating agent, a hole transfer agent, a binder resin, etc. It may be applied on a conductive substrate and dried. In the case of a single-layer type photoreceptor, the binder resin 1
0.1 to 50 parts by weight of the charge generating agent with respect to 00 parts by weight,
The amount is preferably 0.5 to 30 parts by weight, and the electron transfer agent is 5 to 100 parts by weight, preferably 10 to 80 parts by weight. Further, the hole transport material is 5 to 500
It is blended in a proportion of parts by weight, preferably 25 to 200 parts by weight. Further, it is suitable that the total amount of the hole transfer agent and the electron transfer agent is 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 single-layer type photosensitive layer contains an electron-accepting compound, the electron-accepting compound is added in an amount of 0.1 to 100 parts by weight of the binder resin.
It is suitable 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 type electrophotographic photoreceptor, first, a charge generation layer containing a charge generation agent is formed on a conductive substrate by means such as vapor deposition or coating, and then an electron transfer agent is formed on this charge generation layer. A coating liquid containing a binder resin and a binder resin may be applied by means such as coating and dried to form the charge transport layer.

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 suitable to mix in a ratio of parts by weight. When the charge-generating layer contains an electron-accepting compound, the electron-accepting compound is added in an amount of 0.1-40 parts by weight, preferably 0.5-20 parts by weight, based on 100 parts by weight of the binder resin. Appropriate. When the charge generation layer contains an electron transfer agent, the electron transfer agent is added to the binder resin in an amount of 0.
It is suitable 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 charges and a range that does not crystallize, but in the charge-generating layer by light irradiation. In order to easily transport the generated charge, 10 to 10 parts by weight of the electron transfer agent may be added to 100 parts by weight of the binder resin.
It is suitable to mix it in an amount of 500 parts by weight, preferably 25 to 100 resin. When the charge transport 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.
It is suitable to add 5 to 20 parts by weight.

The thickness of the laminated type photosensitive layer is about 0.01 to 5 μm, preferably 0.1 to 3 μm for the charge generation layer.
The charge transport layer has a thickness of 2 to 100 μm, preferably 5 to 50 μm. In the case of a single-layer type photoreceptor, between the conductive base and the photosensitive layer, and in the case of the multilayer type photoreceptor, between the conductive base and the charge generation layer, the conductive base and the charge transport layer. Between or between the charge generation layer and the charge transport layer,
A barrier layer may be formed in a range that does not impair the characteristics of the photoreceptor. Further, a protective layer may be formed on the surface of the photoconductor.

Each of the single-layer type and laminated 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 generating agent.
Further, together with the isatin derivative which is an electron transfer agent, another conventionally known electron transfer agent may be contained in the photosensitive layer. As such an electron transfer agent, 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 )-(ET13) and the like.

[0144]

[Chemical 49]

(In the formula, R ¹⁴² , R ¹⁴³ , R ¹⁴⁴ , 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. )

[0146]

[Chemical 50]

(Wherein 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. )

[0148]

[Chemical 51]

(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.)

[0150]

[Chemical 52]

(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. )

[0152]

[Chemical 53]

(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
¹⁵² may be different. )

[0154]

[Chemical 54]

(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 . )

[0156]

[Chemical 55]

(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. )

[0158]

[Chemical 56]

(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. )

[0160]

[Chemical 57]

(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.)

[0162]

[Chemical 58]

(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.)

[0164]

[Chemical 59]

(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. )

[0166]

[Chemical 60]

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

[0168]

[Chemical formula 61]

(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 group, pyrrolyl group, pyrrolidinyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, 2H-imidazolyl group, pyrazolyl group, triazolyl group, tetrazolyl group, pyranyl group, pyridyl group. Group, piperidyl group, piperidino group, 3-morpholinyl group, morpholino group, thiazolyl group and the like. It may also 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, or an aryl group having 2 to 2 carbon atoms. And the alkenyl group of 6 and the like. As the conductive substrate used in the photoreceptor of the present invention, various materials having conductivity can be used, for example, 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. Further, it is preferable that the conductive substrate has sufficient mechanical strength when used. The photosensitive layer according to the present invention is manufactured by coating a coating solution prepared by dissolving or dispersing a resin composition containing each of the above components in a solvent on 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 the solvent for forming the coating liquid, various organic solvents can be used, for example, alcohols such as methanol, ethanol, isopropanol and butanol, aliphatic hydrocarbons such as n-hexane, octane and 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 and diethylene glycol dimethyl ether, acetone, methyl ethyl ketone, cyclohexanone, etc. Examples thereof include 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 surfactant, a leveling agent, etc. may be used.

[0176]

EXAMPLES The present invention will be described below based on synthesis examples, examples and comparative examples. << Isatin Derivative >> Synthesis Example 1 [Synthesis of N-ethylisatin] In a 200 ml round-bottomed flask, 50 ml of dimethyl sulfoxide was put, and after the inside of the flask was replaced with argon, hydrogenated sodium 1.2 g (0.034) was added under cooling. Mol) and stirred.

Next, while continuing stirring, the above formula (1a-1):

[0178]

[Chemical formula 62]

5.0 g (0.034) of isatin represented by
(Mol) was added dropwise with a solution of 15 ml of dimethylsulfoxide, then the temperature was raised to 30 ° C. and the mixture was further stirred for 1 hour. Next, this solution was ice-cooled again and stirred, while the formula (1b-1):

[0180]

[Chemical formula 63]

5.3 g (0.0) of ethyl iodide represented by
(34 mol) was slowly added dropwise, then the temperature was raised to 50 ° C. and the mixture was stirred for 1 hour. Then, the reaction solution was poured into ice water and extracted with chloroform three times. The separated organic phase was washed with dilute sulfuric acid and water, dried over anhydrous magnesium sulfate, and the crystals obtained by distilling off the solvent were further purified by silica gel chromatography to give a red compound of the above formula. 4.9 g (yield 82.4%) of the title compound represented by (1-1) was obtained.

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 N-ethylisatin represented by the formula (1-1) obtained in Synthesis Example 1 and N, N, represented by the formula (7-1) represented by the formula (7-1), which is a hole transfer agent. Ball mill with 50 parts by weight of N ', N'-tetrakis (p-methylphenyl) -3,3'-dimethylbenzidine (Ip = 5.56 eV) and polycarbonate as a binder resin together with 800 parts by weight of tetrahydrofuran. Were mixed and dispersed for 50 hours to prepare a coating liquid for a single-layer type photosensitive layer.

Then, this coating solution was applied onto an aluminum base tube as 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 As an electron transfer agent, 3,5-dimethyl-3 ′, 5′-dit-butyl-4,4′-diphenoquinone 30 represented by the above formula (3-1) was used instead of N-ethylisatin. 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 parts by weight were used. 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 photosensitive members of the above 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 white light of a halogen lamp, which is an exposure light source of the above-mentioned tester, with 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 elapsed time was measured as the 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.

[0187]

[Table 1]

<< Photoreceptor for Digital Light Source (Single Layer Type-Electron-Accepting Compound Combined 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. The results are shown in Table 2.

[0190]

[Table 2]

<< Photoreceptor for Digital Light Source (Laminate 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
It was dried with hot air at 00 ° C. for 60 minutes to form a charge generation layer having a film thickness of 1 μm. Next, 100 parts by weight of N-ethylisatin represented by the formula (1-1) obtained in Synthesis Example 1 which is an electron transfer agent, and polycarbonate 10 which is a binder resin.
0 parts by weight and 800 parts by weight of toluene were mixed and dispersed in a ball mill for 50 hours to prepare a coating solution for the charge transport layer.

Then, the 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 As an electron transfer agent, 3,5-dimethyl-3 ′, 5′-dit-butyl-4,4′-diphenoquinone 100 represented by the above formula (3-1) was used instead of N-ethylisatin. A photoreceptor for a digital light source having a laminated photosensitive layer was produced in the same manner as in Example 7 except that the parts by weight were used.

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.

[0195]

[Table 3]

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

[0197]

[Chemical 64]

The perylene pigment represented by (Ip = 5.50)
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 of eV) was used. Comparative Example 5 As an electron transfer agent, 3,5-dimethyl-3 ′, 5′-dit-butyl-4,4′-diphenoquinone 30 represented by the above formula (3-1) was used instead of N-ethylisatin. A photoreceptor for an analog light source having a laminated photosensitive layer was produced in the same manner as in Example 8 except that the parts by weight were 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 conducted on the electrophotographic photosensitive members of the above-mentioned respective examples and comparative examples, and the characteristics thereof were evaluated. Photosensitivity test II 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, the white light (light intensity 147 μW / cm ² ) of the halogen lamp which is the exposure light source of the above tester was
Irradiate the surface of the charged photoreceptor (irradiation time 50 ms
ec. ), And 330 msec. From the start of exposure. The surface potential at the elapsed time was measured as the 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.

[0202]

[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 As an electron transfer agent, 3,5-dimethyl-3 ′, 5′-dit-butyl-4,4′-diphenoquinone 100 represented by the above formula (3-1) was used instead of N-ethylisatin. A photoreceptor for an analog light source having a laminated photosensitive layer was produced in the same manner as in Example 9 except that the parts by weight were used.

The above-mentioned photosensitivity test II was conducted on the electrophotographic photosensitive members of the above Examples and Comparative Examples to evaluate the characteristics. The results are shown in Table 5.

[0205]

[Table 5]

[0206]

INDUSTRIAL APPLICABILITY In the present invention , the isatin derivative contained in the photosensitive layer has excellent electron-transporting ability, and also has good solubility in a solvent and good compatibility with a binder resin. Yo
<br/> electrophotographic photoreceptor of the present invention used where the Lee satin derivative as an electron transport agent Te is highly sensitive. When the above isatin 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 the relationship between traction voltage (V) and current (μA) for obtaining the redox 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.

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 5/06 318 C07D 209/38 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A compound represented by the general formula (1) as an electron transfer agent on a conductive substrate: [In the formula, R ¹ represents an alkyl group. Any one of R ^2A , R ^2B , R ^2C and R ^2D represents a hydrogen atom, and the remaining groups are the same or different and represent a hydrogen atom or an alkyl group. And isatin derivative represented by], a hole transporting agent
An electrophotographic photosensitive member comprising a single-layer type photosensitive layer containing: and a charge generating agent . 2. The redox potential of the photosensitive layer is -0.8 to -1.
The electrophotographic photosensitive member according to claim 1, which also contains an electron-accepting compound of 4V. 3. A charge generating layer containing a charge generating agent on a conductive substrate, and a compound represented by the general formula (1): [In the formula, R ¹ represents an alkyl group. Any one of R ^2A , R ^2B , R ^2C and R ^2D represents a hydrogen atom, and the remaining groups are the same or different and represent a hydrogen atom or an alkyl group. ] An electrophotographic photoreceptor comprising a laminated photosensitive layer comprising a charge transport layer containing an isatin derivative represented by: 4. The charge transport layer has a redox potential of −0.8 to −.
4. An electron-accepting compound of 1.4 V is also contained.
The electrophotographic photosensitive member described.