JP2005306744A - Stilbene derivative, manufacturing method therefor and electrophotographic photoconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a stilbene derivative which shows a high degree of charge transfer by having a polycyclic structure in the center and styryl groups at the molecular terminals and those crystallization is effectively prevented, a manufacturing method therefor, and an electrophotographic photoconductor containing the stilbene derivative. <P>SOLUTION: The stilbene derivative is represented by formula (1) (wherein A is a divalent organic group containing a substituted or nonsubstituted 10-30C polycyclic aromatic ring; a plurality of R<SP>1</SP>, R<SP>2</SP>, R<SP>3</SP>, R<SP>4</SP>, R<SP>5</SP>, and R<SP>6</SP>are each a substituted or nonsubstituted 1-20C alkyl group, or the like; and a plurality of Ar<SP>1</SP>and Ar<SP>2</SP>are each a substituted or nonsubstituted 6-30C aryl group), and the manufacturing method therefor comprises reacting a formylated triphenylamine derivative with a diphosphate derivative in the presence of a base. The electrophotographic photoconductor contains the stilbene derivative. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stilbene derivative, a method for producing the same, and an electrophotographic photoreceptor, and in particular, a stilbene derivative having a specific structure at the center and molecular end and having excellent sensitivity characteristics, a method for producing the same, and such a stilbene derivative. The present invention relates to a contained electrophotographic photoreceptor.

Conventionally, as an electrophotographic photosensitive member for an image forming apparatus or the like, an organic photosensitive member made of an organic photosensitive material such as a charge transporting agent, a charge generating agent, and a binder resin (binder resin) has been used. Such an organic photoreceptor is advantageous in that it is easy to manufacture and has a wide degree of freedom in structural design because it has various options for the photoreceptor material as compared with conventional inorganic photoreceptors.
Among such organophotoreceptor materials, a stilbene derivative represented by the following general formula (51) is known as a charge transfer agent having a high charge mobility (see, for example, Patent Document 1).

(In the general formula (51), R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same or different and each represents an alkyl or aryl group containing a substituted alkyl and a substituted aryl group; Ar ³ and Ar ⁵ are the same or Represents an unsubstituted or substituted phenyl group having one or more substituents selected from the group consisting of alkyl, aryl, alkoxy, and halogen substituents, which may be different; Ar ⁴ is carbocyclic or sulfur; A heterocyclic, mononuclear or polynuclear aromatic ring, typically in which the phenyl, naphthyl and anthryl aromatic groups, and substituents defined as substituents at Ar ³ and Ar ⁵ And a group containing 4 to 14 carbon atoms such as a substituted aromatic group having one or more substituents selected from the group of

  Moreover, the stilbene derivative represented by the following general formula (52) is also known as a charge transport agent (for example, refer to Patent Document 2).

(R ¹¹ in the general formula (52) represents a substituted or unsubstituted aromatic residue or heterocyclic residue.)
JP 50-031773 (Claims) JP-A-3-163186 (Claims)

However, since the stilbene derivative described in Patent Document 1 has poor compatibility with the binder resin and is difficult to be uniformly dispersed in the photosensitive layer, there is a problem that charge transfer is difficult to occur and crystallization is likely to occur. It was seen.
The stilbene derivative described in Patent Document 2 exhibits excellent charge transportability when used as an electroluminescent device, but has insufficient compatibility with a binder resin when used as an electrophotographic photoreceptor. Therefore, the same problem as in Patent Document 1 was observed.

Accordingly, the present inventors have excellent compatibility with the binder resin and high charge mobility by having a polycyclic structure at the center and a styryl group at a predetermined position at the molecular end in the stilbene derivative. At the same time, the inventors have found that the feature of effectively preventing crystallization can be obtained, and have completed the present invention.
That is, an object of the present invention is to provide a stilbene derivative that can be suitably used as a charge transfer agent or the like for an electrophotographic photoreceptor, a method for producing the same, and an electrophotographic photoreceptor containing such a stilbene derivative. .

  According to the present invention, a stilbene derivative represented by the following general formula (1) is provided, and the above-described problems can be solved.

(A in the general formula (1) is a divalent organic group containing a substituted or unsubstituted polycyclic aromatic ring having 10 to 30 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted Or an unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, and a plurality of Ar ¹ and Ar ² are each independently substituted or unsubstituted. And an aryl group having 6 to 30 carbon atoms.)

  Further, in constituting the stilbene derivative of the present invention, it is preferable that A in the general formula (1) is a carbocyclic structure or a heterocyclic structure represented by the following formula (2).

In constituting the stilbene derivative of the present invention, a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ^{6 in} the general formula (1) are each independently a hydrogen atom or carbon. An alkyl group having 1 to 6 is preferable.

  Another embodiment of the present invention is a method for producing a stilbene derivative represented by the general formula (1) as represented by the following reaction formula (1), which comprises a formyl represented by the general formula (3). A method for producing a stilbene derivative comprising reacting a triphenylamine derivative with a diphosphate derivative represented by the general formula (4) in the presence of a base.

(A in the reaction formula ^{(1), R 1, R} 2, R 3, R 4, R 5, R 6, Ar 1, and Ar ² is represented by the general formula (1) of A, R ^1, R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Ar ¹ , and Ar ² .

  Further, in carrying out the method for producing a stilbene derivative of the present invention, as a formylated triphenylamine derivative represented by the general formula (3), an aniline derivative represented by the following general formula (5) was used as a raw material. Preference is given to using formylated triphenylamine derivatives obtained by the step Vilsmeier method and the Wittig reaction.

(R ¹ and R ² in the general formula (5) is the same contents as R ¹ and R ² in the general formula (1).)

  Still another embodiment of the present invention is an electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, wherein the photosensitive layer contains a stilbene derivative represented by the following general formula (1). It is preferable that the electrophotographic photosensitive member be characterized.

(A in the general formula (1) is a divalent organic group containing a substituted or unsubstituted polycyclic aromatic ring having 10 to 30 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted Or an unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, and a plurality of Ar ¹ and Ar ² are each independently substituted or unsubstituted. And an aryl group having 6 to 30 carbon atoms.)

  In constituting the electrophotographic photosensitive member of the present invention, the photosensitive layer is preferably a single layer type further containing a charge generating agent and an electron transporting agent.

According to the stilbene derivative of the present invention, as represented by the general formula (1), it has a polycyclic structure at the center and has a styryl group at a predetermined position at the molecular end, thereby being compatible with the binder resin. And high charge mobility, and can effectively prevent crystallization.
That is, the stilbene derivative represented by the general formula (1) has a characteristic that the intramolecular conjugation is widened and the charge mobility is excellent by having a polycyclic structure at the center. Further, by having a styryl group having a predetermined aryl group introduced at a predetermined position at the molecular end, there is a feature that steric hindrance occurs and solubility is improved.
Therefore, when used for an electrophotographic photosensitive member, it is possible to obtain an effect that the sensitivity characteristics are excellent and crystallization hardly occurs.

  Further, according to the stilbene derivative of the present invention, A in the general formula (1) is a predetermined carbocyclic structure or heterocyclic structure having, for example, 10 to 30 carbon atoms, preferably 12 to 30 carbon atoms. The inner conjugation spreads and the charge mobility is excellent. Therefore, an electrophotographic photoreceptor having excellent sensitivity characteristics can be provided by using it as a hole transport agent in the electrophotographic photoreceptor. In addition, since such a structure is easy to introduce, the production of a stilbene derivative having a predetermined structure is facilitated, and such a derivative can be obtained stably.

Further, according to the stilbene derivative of the present invention, since the predetermined substituent in the general formula (1) is a hydrogen atom, the production of a stilbene derivative having a predetermined structure is facilitated, and the derivative can be stabilized. Can be obtained.
Moreover, when the predetermined substituent in General formula (1) is a predetermined alkyl group, it has the characteristic that it is excellent in the solubility to binder resin. That is, when used as a hole transport agent in an electrophotographic photosensitive member, it is uniformly dispersed in the photosensitive layer, so that the sensitivity characteristics are excellent and the production of the electrophotographic photosensitive member is facilitated. Therefore, an electrophotographic photosensitive member having excellent sensitivity can be provided efficiently.

  In addition, according to the method for producing a stilbene derivative of the present invention, a formylated triphenylamine derivative represented by the general formula (3) and a diphosphate ester derivative represented by the general formula (4) By producing a stilbene derivative represented by the general formula (1) by reacting underneath, the compatibility with the binder resin is excellent, so that a high stilbene derivative that exhibits high charge mobility and hardly causes crystallization is obtained. The yield can be obtained.

  Further, according to the method for producing a stilbene derivative of the present invention, after obtaining a triphenylamine compound having a predetermined structure, it is formylated by the Vilsmeier method, whereby the formylated diphenylenamine derivative having a predetermined structure is efficiently obtained. As a result, the stilbene derivative represented by the general formula (1) can be obtained more efficiently.

  In addition, according to the electrophotographic photoreceptor of the present invention, an electron that has high charge mobility and can maintain excellent sensitivity characteristics by containing a stilbene derivative having a predetermined structure represented by the general formula (1). A photographic photoreceptor can be provided.

  In addition, according to the electrophotographic photosensitive member of the present invention, the single-layer type photosensitive member containing the stilbene derivative having the predetermined structure represented by the general formula (1) can be easily configured and manufactured. Nevertheless, an electrophotographic photoreceptor having excellent sensitivity characteristics can be obtained.

  Hereinafter, embodiments relating to a stilbene derivative of the present invention, a method for producing the same, and an electrophotographic photoreceptor will be specifically described with reference to the drawings as appropriate.

[First embodiment]
The first embodiment is a stilbene derivative represented by the following general formula (1). In the general formula (1), A, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Ar ¹ and Ar ² have already been defined above.

  Specific examples of the stilbene derivative represented by the general formula (1) include stilbene derivatives (HTM-A to HTM-C) represented by the following formulas (6) to (8).

Here, the substituent represented by A in the general formula (1) is preferably a carbocyclic structure or a heterocyclic structure represented by the following formula (2).
This is because A in the general formula (1) is a polycyclic structure represented by the following formula (2), so that intramolecular conjugation spreads, electron distribution becomes delocalized, and This is because the charge mobility increases.
Further, such a structure is relatively easy to introduce, and a stilbene derivative having a predetermined stability can be obtained in a relatively high yield.

In the general formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom or a predetermined alkyl group.
This is because, when the predetermined substituent in the general formula (1) is a hydrogen atom, production of stilbene having a predetermined structure is facilitated, and such a derivative can be obtained stably. In addition, since the predetermined substituent in the general formula (1) is a predetermined alkyl group, the solubility in the binder resin is excellent, and thus the characteristics of high charge mobility can be obtained. is there.

[Second Embodiment]
The second embodiment is a method for producing a stilbene derivative represented by the general formula (1) as represented by the following reaction formula (1), which comprises a formylation trimethyl group represented by the general formula (3). A stilbene derivative obtained by reacting a phenylamine derivative and a diphosphate derivative represented by the general formula (4) in the presence of a base to obtain a stilbene derivative represented by the general formula (1) It is a manufacturing method. In the reaction formula (1), A, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Ar ¹ and Ar ² have already been defined above.

1. Synthesis of formylated triphenylamine derivative represented by general formula (3) First, synthesis of formylated triphenylamine derivative represented by general formula (3) used as a raw material for carrying out reaction formula (1) The method will be described in detail.

(1) Reaction formula As shown in the following reaction formula (2), the formylated triphenylamine derivative represented by the general formula (3) is a two-step Vilsmeier as a first step and a third step. It is preferable to synthesize using the method and the Wittig reaction as the second step.
In the reaction formula (2), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , Ar ¹ and Ar ² are the same as R ¹ , R ² , R ³ , The same as the contents of R ⁴ , R ⁵ , R ⁶ , Ar ¹ and Ar ² .

(2) First Step First, using an aniline derivative represented by the general formula (5) as a raw material, it is reacted with two types of iodobenzene derivatives represented by the general formulas (9) and (10), After obtaining the triphenylamine derivative represented by the general formula (11), it is formylated by the first-stage Vilsmeier method to synthesize the formylated triphenylamine derivative represented by the general formula (12). To do.
In synthesizing the triphenylamine derivative represented by the general formula (11), it is preferable to substitute one hydrogen of the amino group constituting the aniline derivative represented by the general formula (5) with an acetyl group in advance. . That is, after protecting a part of the aniline derivative with an acetyl group, it is reacted with one kind of iodobenzene derivative. Next, it is preferable to remove the acetyl group of the obtained acetylated diphenylamine derivative and simultaneously add hydrogen, and further react with another iodobenzene derivative.

Here, in synthesizing the triphenylamine derivative represented by the general formula (11), the aniline derivative represented by the general formula (5) and the two types represented by the general formulas (9) and (10) are used. The addition ratio with the iodobenzene derivative (total amount) is preferably a value in the range of 1: 1 to 1: 6 in terms of molar ratio.
This is because when the ratio of the aniline derivative and the two types of iodobenzene derivatives is less than 1: 1, the amount of triphenylamine derivative that is the target product may be reduced. . On the other hand, if the addition ratio of the aniline derivative and the two types of iodobenzene derivatives exceeds 1: 6, a large amount of unreacted iodobenzene derivative remains, so that it is difficult to purify the target triphenylamine derivative. This is because it may become.
In addition, it is preferable to make the addition ratio of the iodobenzene derivative represented by general formula (9) and (10) into the value of about 1: 1 by molar ratio.

In reacting the aniline derivative represented by the general formula (5) with the two types of iodobenzene derivatives represented by the general formulas (9) and (10), the reaction temperature is usually 160 to 220 ° C. It is preferable to set the value within the range and the reaction temperature within the range of 4 to 30 hours.
This is because, under such reaction conditions, a desired reaction can be efficiently performed using a relatively simple manufacturing facility.

Furthermore, the Philsmeier reagent (Vilsmeier reagent) used in the Filsmeier method is preferably a combination of the following compounds (i) and (ii).
(i) Halogenating agents such as phosphorus oxychloride, phosgene, oxalyl chloride, thionyl chloride, triphenylphosphine-bromine, hexachlorotriphosphazatriene
(ii) N, N-dimethylformamide (DMF), N-methylformanilide (MFA), N-formylmorpholine, N, N-diisopropylformamide In the present invention, as the Filsmeier reagent, phosphorus oxychloride and a solvent A combination with DMF that can also be used as
Furthermore, the Filsmeier method can be promoted by adding a catalytic amount of zinc chloride or the like.

In the preparation of the Vilsmeier reagent, the ratio of the compounds (i) and (ii) used is usually a molar ratio, preferably within a range of 1: 1 to 1:20. A value in the range of 1: 5 is more preferable.
Moreover, regarding the usage-amount of a Vilsmeier reagent, it is preferable to set it as the value within the range of 1-5 times mole amount with respect to 1 mol of triphenylamine derivatives represented by General formula (11), 1-3 times More preferably, the value is within the range of the molar amount.
Furthermore, with respect to the reaction conditions for formylation of the triphenylamine derivative in the Vilsmeier method, it is usually carried out at a temperature of 130 ° C. or lower, and the reaction time is preferably set to a value in the range of 5 to 120 minutes.
It should be noted that the second-stage Vilsmeier method can also be performed in accordance with the conditions of the first-stage Vilsmeier method.

(3) Second Step Next, a triphenylamine derivative represented by the general formula (14) is synthesized by a Wittig reaction. That is, it reacts with the presence of formylated triphenylamine derivative represented by general formula (12), phosphorus ylide derivative represented by formula (13), and n-butyllithium as a catalyst.

Here, the addition ratio of the formylated triphenylamine derivative represented by the general formula (12) and the phosphorus ylide derivative represented by the formula (13) is within a range of 1: 1 to 1: 3 by molar ratio. It is preferable to use a value.
This is because the amount of the triphenylamine derivative represented by the general formula (14) decreases when the addition ratio of the formylated triphenylamine derivative and the phosphorus ylide derivative is less than 1: 1. Because there is. On the other hand, when the addition ratio of the formylated triphenylamine derivative and the phosphorus ylide having a diphenylethenyl group exceeds 1: 3, a large amount of unreacted phosphorus ylide derivative remains, and therefore, it is represented by the general formula (14). This is because it may be difficult to purify the triphenylamine derivative.
Therefore, the addition ratio of the formylated triphenylamine derivative represented by the general formula (12) and the phosphorus ylide derivative represented by the formula (13) is within a range of 1: 1.2 to 1: 2. More preferably, the value of

Further, when the formylated triphenylamine derivative represented by the general formula (12) and the phosphorus ylide derivative represented by the formula (13) are reacted, the reaction temperature is usually a value within the range of −30 to 20 ° C. In addition, the reaction time is preferably set to a value within the range of 5 to 120 minutes.
This is because, under such reaction conditions, a desired reaction can be efficiently performed using a relatively simple manufacturing facility.
Examples of the reagent used in the Wittig method include sodium alkoxides such as n-butyllithium, sodium methoxide and sodium ethoxide; metal hydrides such as sodium hydride, potassium hydride and potassium sodium hydride. One kind alone or a combination of two or more kinds may be mentioned.

(4) Third Step Next, the triphenylamine derivative represented by the general formula (14) is formylated by the second-stage Vilsmeier method to form the formylated triglyceride represented by the general formula (3). A phenylamine derivative is obtained.
In addition, about the reaction conditions of the 2nd-stage Filsmeier method in a 3rd process, it is preferable to carry out according to the 1st-stage Filsmeier method in a 1st process.

2. Synthesis of diphosphate ester derivative Here, a method for synthesizing the diphosphate ester derivative represented by the general formula (4) used as a raw material for carrying out the reaction formula (1) will be described in detail.
That is, the diphosphate derivative represented by the general formula (4) can be synthesized as shown in the following reaction formula (3).

In carrying out the synthesis reaction of the diphosphate derivative, for example, it is preferable to react the dichloromethyl derivative by adding triethyl phosphite without solvent or in a suitable solvent. This is because the diphosphate derivative represented by the general formula (4) used in the reaction formula (1) can be obtained in a high yield by reacting in this way.
Here, when the synthesis reaction is caused, the proportion of triethyl phosphite to be used is preferably at least 3 moles per 1 mole of the dichloromethyl derivative, and the value is within the range of 3 to 3.6 moles. It is more preferable.
Moreover, it is preferable to make this reaction temperature into the value within the range of 80-150 degreeC normally, and to make reaction time into the value within the range of 1-4 hours.

The solvent used for synthesizing the diphosphate derivative is not particularly limited as long as it does not affect the reaction. Examples thereof include ethers such as diethyl ether, tetrahydrofuran, and dioxane; methylene chloride, chloroform, dichloroethane, and the like. Preferred examples include halogenated hydrocarbons of: benzene, toluene and other aromatic hydrocarbons, dimethylformamide and the like.
It is also preferable to add a predetermined amount of a tertiary amine when synthesizing the diphosphate derivative. This is because the alkylamine is removed from the reaction system by the tertiary amine, so that the synthesis reaction of the diphosphate derivative can be promoted. Suitable tertiary amines include, for example, one kind of triethylamine, tributylamine, pyridine, 4- (dimethylamino) pyridine, or a combination of two or more kinds.

3. Reaction conditions Next, the reaction conditions for carrying out the reaction formula (1) will be described in detail.
That is, the stilbene derivative represented by the general formula (1) can be synthesized as shown in the above reaction formula (1).

(1) Reaction temperature and reaction time The reaction of the formylated triphenylamine derivative represented by the general formula (3) with the diphosphate ester derivative represented by the general formula (4) is usually at -10 to 25 ° C. Preferably, the reaction time is set to a value within the range of 3 to 12 hours.

(2) Solvent As a suitable solvent used for the reaction of the formylated triphenylamine derivative represented by the general formula (3) and the diphosphate ester derivative represented by the general formula (4), the reaction is affected. However, examples thereof include ethers such as diethyl ether, tetrahydrofuran and dioxane; halogenated hydrocarbons such as methylene chloride, chloroform and dichloroethane; and aromatic hydrocarbons such as benzene and toluene.

(3) Base The base used in such a reaction includes sodium alkoxide such as sodium methoxide and sodium ethoxide, metal hydride such as sodium hydride and potassium hydride, or metal salt such as n-butyllithium. Are mentioned as preferred.
Here, it is preferable to make the addition amount of this base into the value within the range of 1.0-1.5 mol with respect to 1 mol of formylation triphenylamine derivatives.
The reason for this is that when the amount of the base added is less than 1.0 mol, the formylated triphenylamine derivative represented by the general formula (3) and the diphosphate ester derivative represented by the general formula (4) This is because the reactivity between and may be significantly reduced.
On the other hand, when the amount of the base added exceeds 1.5 moles, between the formylated triphenylamine derivative represented by the general formula (3) and the diphosphate ester derivative represented by the general formula (4) This is because it may be extremely difficult to control the reaction.

(4) Addition ratio In carrying out the reaction between the diphosphate ester derivative represented by the general formula (4) and the formylated triphenylamine derivative represented by the general formula (3), the addition ratio is The molar ratio is preferably in the range of 1: 2 to 1: 3.
The reason for this is that when the addition ratio of the formylated triphenylamine derivative and the diphosphate derivative is less than 1: 2, the formylated triphenylamine derivative and the diphosphate ester derivative are 1: 1. It is because it becomes easy to react correspondingly. Moreover, it is because an unreacted formylated triphenylamine derivative may make purification difficult when the addition ratio exceeds 1: 3.
Therefore, the addition ratio of the diphosphate derivative represented by the general formula (4) and the formylated triphenylamine derivative represented by the general formula (3) is set to a molar ratio of 1: 2.2 to 1: 2. More preferably, the value is within the range of .5.

[Third Embodiment]
The third embodiment is an electrophotographic photosensitive member in which a photosensitive layer is provided on a conductive substrate, and the photosensitive layer contains a stilbene derivative represented by the general formula (1). It is a photoreceptor.
In addition, although there exist a single layer type and a laminated type in an electrophotosensitive body, the stilbene derivative of this invention is applicable to any.
However, it can be used for both positive and negative charge types, has a simple structure and is easy to manufacture, can suppress film defects when forming a layer, has few interfaces between layers, and can improve optical characteristics, etc. From the viewpoint, it is preferably applied to a single layer type.

1. Single Layer Type Photoreceptor (1) Basic Configuration As shown in FIG. 1A, the single layer type photoreceptor 10 is obtained by providing a single photosensitive layer 14 on a conductive substrate 12.
This photosensitive layer is prepared by, for example, dissolving a stilbene derivative (hole transport agent) represented by the general formula (1), a charge generator, a binder resin, and, if necessary, an electron transport agent in an appropriate solvent. Alternatively, it can be formed by dispersing and coating the obtained coating solution on a conductive substrate and drying. Such a single layer type photoreceptor is characterized in that it can be applied to either a positive or negative charge type with a single configuration, has a simple layer configuration, and is excellent in productivity.
Further, the obtained single-layer type photoreceptor has a characteristic that it has excellent sensitivity characteristics because it contains a stilbene derivative represented by the general formula (1).
Further, when an electron transport agent is contained in the photosensitive layer of the single-layer type photoreceptor, electrons are efficiently exchanged between the charge generating agent and the hole transport agent, and the sensitivity and the like are more stable. There is a trend.

(2) Charge generator (2) -1 type As the charge generator used in the electrophotographic photoreceptor of the present invention, metal-free phthalocyanine (τ type or X type), titanyl phthalocyanine (α type or Y type), It is preferable to include at least one compound selected from the group consisting of hydroxygallium phthalocyanine (type V) and chlorogallium phthalocyanine (type II).
The reason for this is to provide an electrophotographic photosensitive member with more excellent sensitivity characteristics, electrical characteristics, stability, etc. when a hole transporting agent and an electron transporting agent are used in combination by specifying the type of charge generating agent. It is because it can do.

(2) -2 Specific Example Among these charge generators, it is more preferable to use phthalocyanine pigments (CGM-A to CGM-D) represented by the following formulas (16) to (19). preferable.

  Moreover, it is also preferable to use a conventionally known charge generating agent alone or in combination. Such charge generators include phthalocyanine pigments such as oxo titanyl phthalocyanine, perylene pigments, bisazo pigments, diketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo Organic photoconductors such as pigments, azulenium pigments, cyanine pigments, pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments, quinacridone pigments, selenium, selenium-tellurium, selenium- One kind of inorganic photoconductive agent such as arsenic, cadmium sulfide, and amorphous silicon, or a mixture of two or more kinds may be used.

Among the charge generating agents described above, in particular, when used in a digital optical image forming apparatus such as a laser beam printer or a facsimile provided with a light source such as a semiconductor laser, a photosensitive material having sensitivity in a wavelength region of 700 nm or more. Therefore, it is preferable that at least one of metal-free phthalocyanine, titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine is contained.
On the other hand, when used in an image forming apparatus of an analog optical system such as an electrostatic copying machine equipped with a white light source such as a halogen lamp, a photoreceptor having sensitivity in the visible region is required. Pigments and bisazo pigments are preferably used.

Moreover, when using the compound (CGM-B) represented by the formula (17) described above among the charge generating agents used in the present invention, a dispersion aid represented by the following formula (20) (for example, C. IPigment Orange 16) may be added.
This is because the charge generating agent (CGM-B) and the dispersion auxiliary agent (C. IPigment Orange 16) are used together to improve the dispersibility of CGM-B in the coating solution, and the coating solution pot This is because the life can be lengthened.
In addition, when using the dispersion | distribution adjuvant represented by Formula (20), it is preferable to make the addition amount into the value within the range of 30-200 weight part with respect to 100 weight part of all the electric charge generating agents.
The reason for this is that when the amount of the dispersion aid added is less than 30 parts by weight, dispersibility in the coating solution of CGM-B becomes insufficient, and an appropriate film as a photoreceptor cannot be produced. is there. On the other hand, when the dispersion aid exceeds 200 parts by weight, the effect of increasing the quantum yield of the charge generating agent becomes insufficient, and the sensitivity characteristics, electrical characteristics, stability, etc. of the electrophotographic photoreceptor can be improved. It is because it becomes impossible.

(3) Hole transport agent In the electrophotographic photoreceptor of the present invention, it is also preferable that the photosensitive layer contains another conventionally known hole transport agent together with the stilbene derivative of the present invention which is a hole transport agent.
Examples of such a hole transport agent include various compounds having high hole transport ability, such as compounds represented by the following formulas (21) to (33) (HTM-1 to HTM-13).

(In the formula, R ^h1 , R ^h2 , R ^h3 , R ^h4 , R ^h5 and R ^h6 are independent and are each a halogen atom, an alkyl group which may have a substituent, or an alkoxy which may have a substituent. An aryl group which may have a group or a substituent, a and b are the same or different and represent an integer of 0 to 4, c, d, e and f are the same or different and represent an integer of 0 to 5 However, when a, b, c, d, e or f is 2 or more, each R ^h1 , R ^h2 , R ^h3 , R ^h4 , R ^h5 and R ^h6 may be different.)

Wherein R ^h7 , R ^h8 , R ^h9 , R ^h10 and R ^h11 are the same or different and are a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent or a substituent. An aryl group which may have a group, g, h, i and j are the same or different and each represents an integer of 0 to 5, and k represents an integer of 0 to 4, provided that g, h, i, When j or k is 2 or more, each R ^h7 , R ^h8 , R ^h9 , R ^h10 and R ^h11 may be different.)

^{(Wherein, R h12, R h13, R} h14 and R ^h15 are the same or different, a halogen atom, chromatic an optionally substituted alkyl group, an alkoxy group or a substituted group which may have a substituent R ^h16 may be a halogen atom, a cyano group, a nitro group, an alkyl group that may have a substituent, an alkoxy group that may have a substituent, or a substituent. Represents a good aryl group, m, n, o and p are the same or different and represent an integer of 0 to 5. q represents an integer of 0 to 6, provided that m, n, o, p or q is 2. when the above, each ^{R h12, R h13, R h14} , R h15 and R ^h16 may be different.)

( ^Wherein R ^h17 , R ^h18 , R ^h19 and R ^h20 are the same or different and have a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent or a substituent. R, s, t and u are the same or different and each represents an integer of 0 to 5, provided that when r, s, t or u is 2 or more, each R ^h17 , R ^h18, R ^h19 and R ^h20 may be different.)

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

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

(In the formula, R ^h30 , R ^h31 , R ^h32 and R ^h33 are the same or different and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

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

( ^Wherein R ^h39 represents a hydrogen atom or an alkyl group, and R ^h40 , R ^h41 and R ^h42 are the same or different and represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group.)

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

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

(In the formula, R ^h50 , R ^h51 , R ^h52 , R ^h53 , R ^h54 and R ^h55 are the same or different and are an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aryl group which may have a group, α represents an integer of 1 to 10, and v, w, x, y, z and β are the same or different and represent an integer of 0 to 2, provided that v, When w, x, y, z or β is 2, each R ^h50 , R ^h51 , R ^h52 , R ^h53 , R ^h54 and R ^h55 may be different.)

^Wherein R ^h56 , R ^h57 , R ^h58 and R ^h59 are the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and Φ-1 to Φ-3 are structures represented by the following formulae .)

  Further, in the present invention, together with or instead of the above exemplified hole transporting agents (HTM-1) to (HTM-13), a conventionally known hole transporting substance, 2,5-di (4-methyl) Oxadiazole compounds such as aminophenyl) -1,3,4-oxadiazole, styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinyl carbazole, organic polysilane compounds, 1- Pyrazoline compounds such as phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazoles Compounds, pyrazole compounds, triazole compounds, etc. Nitrogen ring compounds include singly or in a combination of two or more of such condensed polycyclic compounds.

(4) Electron transport agent The electron transport agent used in the present invention is preferably a compound containing a quinone derivative and a naphthoquinone derivative. The reason for this is that, by using a specific compound as an electron transporting agent, the electron accepting property is excellent, and the compatibility with the charge generating agent is excellent. This is because a photographic photoreceptor can be provided.

  Specific examples of these electron transfer agents include compounds (ETM-A to ETM-C) represented by the following formulas (35) to (37).

Moreover, it is also preferable to use a conventionally known electron transport agent alone or in combination. Examples of such electron transporting agents include diphenoquinone derivatives, benzoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, 3,4,5,7-tetranitro-9-fluorenone derivatives, dinitroanthracene derivatives, Dinitroacridine derivatives, nitroantharaquinone derivatives, dinitroanthraquinone derivatives, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride And various compounds having an electron accepting property such as dibromomaleic anhydride, and one kind or a mixture of two or more kinds may be used.
Of these electron transfer agents, compounds having an electron mobility of 1.0 × 10 ⁻⁸ cm ² / V / sec or more at an electric field strength of 5 × 10 ⁵ v / cm are more preferable.

(5) Binder Resin Various resins conventionally used in the photosensitive layer can be used as the binder resin for dispersing each component. For example, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene Resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, polyester resin, alkyd resin, polyamide resin, polyurethane resin, polycarbonate resin, polyarylate resin, polysulfone resin, diallyl phthalate resin, ketone resin , Polyvinyl butyral resin, polyether resin, polyester resin, etc .; silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, other crosslinkable thermosetting resins; epoxy acrylate DOO, urethane - resin such as photocurable resin such as acrylate can be used.
In particular, a polycarbonate resin is a preferable binder resin because it is excellent not only in transparency and heat resistance but also in mechanical properties and compatibility with a hole transport agent.

(6) Additives In addition to the above-mentioned components, the photosensitive layer contains various conventionally known additives such as antioxidants, radical scavengers, singlet quenchers, and the like within a range that does not adversely affect the electrophotographic characteristics. Deterioration inhibitors such as char and ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be blended. In order to improve the sensitivity of the photosensitive layer, a known sensitizer such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

(7) Mixing ratio and thickness When the electrophotographic photosensitive member of the present invention is a single-layer type photosensitive member, the charge generating agent is 0.1 to 50 parts by weight, preferably 100 parts by weight of the binder resin. What is necessary is just to mix | blend in the ratio of 0.5-30 weight part. What is necessary is just to mix | blend the stilbene derivative (hole transport agent) of this invention in the ratio of 20-500 weight part with respect to 100 weight part of binder resin, Preferably it is 30-200 weight part. When the electron transport agent is contained, the ratio of the electron transport agent is 5 to 100 parts by weight, preferably 10 to 80 parts by weight with respect to 100 parts by weight of the binder resin.

  In addition, when the electrophotographic photoreceptor of the present invention is a laminated photoreceptor, the charge generator and the binder resin constituting the charge generation layer can be used in various ratios, but the binder resin 100 can be used. It is appropriate to mix the charge generating agent in an amount of 5 to 1000 parts by weight, preferably 30 to 500 parts by weight with respect to parts by weight. In the case where a hole transport agent is contained in the charge generation layer, the ratio of the hole transport agent is 10 to 500 parts by weight, preferably 50 to 200 parts by weight with respect to 100 parts by weight of the binder resin. .

  The hole transport agent constituting the charge transport layer and the binder resin can be used in various proportions within a range that does not inhibit charge transport and a range that does not crystallize. The stilbene derivative (hole transport agent) of the present invention is blended in an amount of 10 to 500 parts by weight, preferably 25 to 200 resins, with respect to 100 parts by weight of the binder resin so that the charges can be easily transported. Is appropriate. When the charge transport layer contains an electron transport agent, the ratio of the electron transport agent is 5 to 200 parts by weight, preferably 10 to 100 parts by weight, based on 100 parts by weight of the binder resin.

(8) Structure Further, the thickness of the photosensitive layer in the single-layer type photoreceptor is 5 to 100 μm, preferably 10 to 50 μm.
As the conductive substrate on which such a photosensitive layer is formed, various materials having conductivity can be used, for example, iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, Examples thereof include metals such as cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, plastic materials on which the above metal is vapor-deposited or laminated, glass coated with aluminum iodide, tin oxide, indium oxide, and the like.

  Further, the shape of the conductive substrate may be any of a sheet shape, a drum shape, or the like in accordance with the structure of the image forming apparatus to be used. The substrate itself is conductive or the surface of the substrate is conductive. As long as it has. The conductive substrate preferably has sufficient mechanical strength when used. When the photosensitive layer is formed by a coating method, the charge generator, charge transport agent, binder resin and the like exemplified above, together with a suitable solvent, a known method such as a roll mill, ball mill, attritor, paint shaker, super A dispersion liquid may be prepared by dispersing and mixing using a sonic disperser or the like, and this may be applied and dried by a known means.

  Further, regarding the configuration of the single-layer type photoreceptor, as shown in FIG. 1B, a barrier layer 16 is formed between the conductive substrate 12 and the photosensitive layer 14 in a range that does not impair the characteristics of the photoreceptor. The structure of the single layer type photoreceptor 10 ′ may be used. Further, as shown in FIG. 1C, a single-layer type photoreceptor 10 ″ in which a protective layer 18 is formed on the surface of the photosensitive layer 14 may be used.

(9) Production method Various organic solvents can be used as a solvent for preparing the dispersion. For example, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic systems such as n-hexane, octane and cyclohexane Hydrocarbons: aromatic hydrocarbons such as benzene, toluene, xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether Ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformaldehyde, dimethylformamide, dimethylsulfo Sid and the like. These solvents are used alone or in admixture of two or more.
Further, a surfactant, a leveling agent or the like may be used in order to improve the dispersibility of the charge transport agent or charge generator and the smoothness of the photosensitive layer surface.

2. Multilayer Photoreceptor As shown in FIG. 2A, the multilayer photoreceptor 20 is formed by forming a charge generation layer 24 containing a charge generation agent on a conductive substrate 12 by means of vapor deposition or coating, Next, a coating liquid containing at least one stilbene derivative (hole transport agent) represented by the general formula (1) and a binder resin is applied onto the charge generation layer 24 and dried to be the charge transport layer 22. It is produced by forming.
Contrary to the above structure, in the multilayer photoconductor 20 ′, as shown in FIG. 2B, the charge transport layer 22 is formed on the conductive substrate 12, and the charge generation layer 24 is formed thereon. May be.
However, since the charge generation layer 24 is much thinner than the charge transport layer 22, for protection, the charge transport layer 22 is formed on the charge generation layer 24 as shown in FIG. It is more preferable to form
The charge generating agent, hole transporting agent, electron transporting agent, binder and the like can be the same as those of the single layer type photoreceptor.

In addition, a positive or negative charge type is selected depending on the formation order of the charge generation layer and the charge transport layer and the kind of the charge transport agent used in the charge transport layer. For example, as described above, when a charge generation layer is formed on a conductive substrate and a charge transport layer is formed thereon, a hole such as the stilbene derivative of the present invention is used as a charge transport agent in the charge transport layer. When a transport agent is used, the photoreceptor is a negatively charged type. In this case, the charge generation layer may contain an electron transport agent.
The multilayer electrophotographic photosensitive member of the present invention is characterized in that the residual potential of the photosensitive member is lowered and that it has a predetermined sensitivity.
The thickness of the photosensitive layer in the multilayer photoconductor is about 0.01 to 5 μm, preferably about 0.1 to 3 μm for the charge generation layer, and about 2 to 100 μm, preferably about 5 to 50 μm for the charge transport layer. It is.

  Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples.

[Example 1]
(1) Synthesis of a stilbene derivative having a triphenylamine structure containing a diphenylethenyl group (1) -1 Synthesis of a diphosphate derivative A synthesis of a diphosphate derivative represented by formula (39) is represented by the following reaction formula ( Synthesized according to 4). That is, after adding 15 g (0.0545 mol) of bis (chloromethyl) anthracene to a 500 ml flask, 21.7 g (0.131 mol) of phosphorous acid triethyl ester was added, and the condition was kept at 150 ° C. for 4 hours. , Reacted. Subsequently, after cooling to room temperature, excess phosphorous acid triethyl ester was distilled off under reduced pressure. The obtained white residue was washed with n-hexane and vacuum dried to obtain 21 g of a diphosphate derivative represented by the formula (39) (yield 93%).

(1) -2 Synthesis of triphenylamine derivative The synthesis of the triphenylamine compound represented by the formula (42) was carried out according to the following reaction formula (5).
That is, 111 g (0.8 mol) of anhydrous potassium carbonate and 5.1 g (0.08 mol) of anhydrous copper carbonate are added into a 500 ml two-necked flask, heated under vacuum for 2 hours, and stirred until uniform. And dried. Subsequently, after cooling to room temperature, after adding 45 g (0.33 mol) of the aniline compound represented by the following formula (40) and 163 g (0.8 mol) of iodobenzene represented by the formula (41), 180 The mixture was reheated to ° C. and reacted for 12 hours. Then, after cooling to room temperature, 100 ml of toluene was added and the filtration process was implemented. The obtained residue was dissolved in toluene and dried using activated clay. Thereafter, the obtained crystal was purified using silica gel column chromatography (developing solvent: chloroform solvent) to obtain 66.1 g of a triphenylamine derivative represented by the formula (42) (yield 70%).

(1) -3 Synthesis of Formylated Triphenylamine Derivative Next, synthesis of a formylated triphenylamine derivative represented by the formula (43) was performed according to the following reaction formula (6).
That is, in a 500 ml flask, 60 g (0.21 mol) of the triphenylamine derivative represented by the formula (42), 250 ml of dimethylformamide (DMF), and 48 g of oxychlorophosphoric acid dissolved in 150 ml of dimethylformamide (0 .31 mol), and the mixture was reacted under stirring at 70 ° C. for 30 minutes. The obtained reaction solution was dropped into a mixed solution composed of 400 m of ion exchange water and 200 ml of toluene, and then the produced toluene layer was washed with ion exchange water. Thereafter, anhydrous sodium sulfate and activated clay were added to the obtained organic layer, followed by drying and adsorption treatment. Subsequently, toluene was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (developing solvent: chloroform solvent) to obtain 48 g of a formylated triphenylamine derivative represented by the formula (43) ( Yield 72%).

(1) -4 Synthesis of phosphorus ylide Subsequently, the synthesis of phosphorus ylide represented by the formula (45) was carried out according to the following reaction formula (7).
That is, 500 g (2.47 mol) of diphenylchloromethane represented by the formula (44) and 492 g (3 mol) of triethyl phosphite were added, heated at 160 ° C., and stirred for 3 hours. Then, after cooling to room temperature, excess phosphorous acid triethyl ester was distilled off under reduced pressure to obtain 639 g of phosphorus ylide represented by the formula (45) (yield 85%).

(1) -5 Synthesis of Triphenylamine Derivative Next, a triphenylamine derivative represented by the following formula (46) was synthesized according to the following reaction formula (8).
That is, after adding 33.8 g (0.11 mol) of the phosphorus ylide derivative represented by the formula (45) into a 500 ml two-necked flask maintained at −20 ° C., argon gas replacement was performed, and further 100 ml of THF was accommodated. The reaction was carried out at -20 ° C or lower. Thereafter, 68.8 ml (0.11 mol) of n-BuLi (1.6 mol / l in hexane solution) was added dropwise, and the mixture was stirred at -20 ° C. or lower for 10 minutes to be reacted. Furthermore, 25 g (0.079 mol) of a formylated triphenylamine derivative represented by the formula (43) was added dropwise and stirred at −20 ° C. for 15 minutes. This reaction solution was added to 500 ml of ion-exchanged water and extracted with toluene. Further, the organic layer was washed 5 times with ion-exchanged water, and then the organic layer was dried with anhydrous sodium sulfate. Thereafter, the organic solvent was distilled off, and the obtained residue was purified by silica gel column chromatography (developing solvent: chloroform solvent) to obtain 27.9 g of a triphenylamine derivative represented by the formula (46). (Yield 76%).

(1) -6 Synthesis of Formylated Triphenylamine Derivative Next, synthesis of a formylated triphenylamine derivative represented by the following formula (47) was carried out according to the following reaction formula (9).
That is, in a 500 ml flask, 20 g (0.043 mol) of the triphenylamine derivative represented by the formula (46), 100 ml of dimethylformamide (DMF), and 9.88 g of oxychlorophosphoric acid dissolved in 100 ml of dimethylformamide. (0.064 mol), and stirred at 85 ° C. for 30 minutes. Thereafter, the reaction solution was dropped into a mixed solution composed of 400 ml of ion exchange water and 200 ml of toluene, and the obtained toluene layer was stirred and washed with ion exchange water. Further, the obtained organic layer was added with anhydrous sodium sulfate and activated clay, dried and adsorbed, and then toluene was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography (developing solvent: chloroform solvent) to obtain 16.5 g of a formylated triphenylamine derivative represented by the formula (47) (yield 78%).

(1) -7 Synthesis of Stilbene Derivative Next, a stilbene derivative represented by the formula (6) was synthesized according to the following reaction formula (10).
That is, in a 500 ml two-necked flask, 5 g (0.0121 mol) of the diphosphate ester represented by the formula (39) obtained in (1) -1 was added and kept at 0 ° C. with argon. After the replacement, 50 ml of THF and 5.59 g (0.0290 mol) of 28% NaOMe were accommodated and stirred for 30 minutes. Next, after 14.3 g (0.029 mol) of the formylated triphenylamine derivative represented by the above formula (47) was dissolved in the container, the mixture was stirred at room temperature for about 12 hours. Next, the reaction solution was poured into 500 ml of ion-exchanged water and extracted with toluene, and then the obtained organic layer was washed 5 times with ion-exchanged water. Thereafter, the organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off. The obtained residue was purified by silica gel column chromatography (developing solvent: chloroform solvent) to obtain 10.3 g of a stilbene derivative represented by the formula (6) (yield 73.5%).

(2) Preparation of electrophotographic photosensitive member
Using the obtained stilbene derivative as a hole transport agent, a single layer type electrophotographic photosensitive member was prepared, and the initial surface potential, half-exposure amount and residual potential were measured. That is, 60 parts by weight of the obtained stilbene derivative (HTM-A) represented by the formula (6) is used as a hole transport agent, and an X-type metal-free phthalocyanine represented by the formula (16) as a charge generator. 5 parts by weight of (CGM-A) and 100 parts by weight of the Z-type polycarbonate resin represented by the formula (48) as a binder resin were added to 800 parts by weight of tetrahydrofuran as a solvent. Subsequently, it was mixed and dispersed for 50 hours using a ball mill to prepare a coating solution for a single-layer type photosensitive layer. The obtained coating solution is applied on a conductive substrate (aluminum base tube) by a dip coating method and dried with hot air at 100 ° C. for 30 minutes to form a single-layer type photosensitive layer having a thickness of 25 μm. An electrophotographic photosensitive member was obtained.

(3) Evaluation Initial electrical characteristics of the obtained electrophotographic photosensitive member, that is, initial surface potential (Vo), half-exposure amount (E1 _{/ 2} ) and residual potential (Vr) were measured. First, using a drum sensitivity tester (manufactured by GENTEC), the surface potential was charged to 700 V and measured to obtain an initial surface potential (Vo). Next, for half exposure (E _1/2 ), exposure was performed with monochromatic light having a wavelength of 780 nm (half width: 20 nm, light intensity: 1.5 μJ / cm ² ) extracted from the light of the halogen lamp using a bandpass filter. Then, the time required until the surface potential became 1/2 was measured. Furthermore, the surface potential at the time when 330 msec has elapsed from the start of exposure was measured and used as the residual potential (Vr). The obtained results are shown in Table 1.

[Examples 2 to 4]
In Examples 2 to 4, 20 parts by weight of quinone derivatives (ETM-A to ETM-C) represented by the formulas (35) to (37) were added to the coating liquid of Example 1 as electron transport materials, respectively. In the same manner as in Example 1, a single-layer type photosensitive layer was prepared and evaluated.

[Examples 5 to 8]
In Examples 5-8, it represents with Formula (7) instead of the stilbene derivative (HTM-A) represented with Formula (6) as a hole transport agent in the coating liquid of Examples 1-4. A single-layer type photosensitive layer was prepared and evaluated in the same manner as in Examples 1 to 4 except that the stilbene derivative (HTM-B) was added.

[Examples 9 to 12]
In Examples 9-12, it represents with Formula (8) instead of the stilbene derivative (HTM-A) represented with Formula (6) as a hole transport agent in the coating liquid of Examples 1-4. A single-layer type photosensitive layer was prepared and evaluated in the same manner as in Examples 1 to 4, except that the stilbene derivative (HTM-C) was added.

[Comparative Examples 1-4]
In Comparative Examples 1-4, it represents with Formula (49) instead of the stilbene derivative (HTM-A) represented with Formula (6) as a hole transport agent in the coating liquid of Examples 1-4. A monolayer type photosensitive layer was prepared in the same manner as in Examples 1 to 4, except that the stilbene derivative (HTM-D) was added. However, immediately after the film formation, the single-layer type photosensitive layer crystallized and the evaluation was stopped.

[Comparative Examples 5 to 8]
In Comparative Examples 5-8, it represents with Formula (50) instead of the stilbene derivative (HTM-A) represented with Formula (6) as a hole transport agent in the coating liquid of Examples 1-4. A monolayer type photosensitive layer was prepared in the same manner as in Examples 1 to 4, except that the stilbene derivative (HTM-E) was added. However, immediately after the film formation, the single-layer type photosensitive layer crystallized and the evaluation was stopped.

＊初期表面電位、残留電位および半減露光量における×は、結晶化のため評価できなかったことを示している。

* In the initial surface potential, residual potential, and half-exposure dose, x indicates that evaluation was not possible due to crystallization.

As described above in detail, the stilbene derivative of the present invention has a polycyclic structure at the center and has a styryl group at a predetermined position of the molecular end, so that it has excellent compatibility with the binder resin, and thus has high charge transfer. In addition to showing the degree, it is possible to obtain the characteristics of effectively preventing crystallization. Moreover, since the electrophotographic photoreceptor of the present invention uses the stilbene derivative represented by the general formula (1) as a hole transport agent, it has excellent sensitivity characteristics and effectively prevents crystallization. Therefore, the electrophotographic photosensitive member of the present invention is expected to contribute to speeding up and high performance of various image forming apparatuses such as copying machines and printers.
Moreover, since the stilbene derivative represented by the general formula (1) has a high hole transporting ability, it is suitably used as a hole transporting agent in an electrophotographic photosensitive member, as well as a solar cell, an electroluminescence element and the like. It can be used in various fields.

(A)-(c) is a figure provided in order to demonstrate the basic structure and deformation | transformation structure of a single layer type photoreceptor. (A)-(b) is a figure provided in order to demonstrate the basic structure and deformation | transformation structure of a laminated type photoreceptor.

Claims (7)

A stilbene derivative represented by the following general formula (1):

(A in the general formula (1) is a divalent organic group containing a substituted or unsubstituted polycyclic aromatic ring having 10 to 30 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted Or an unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, and a plurality of Ar ¹ and Ar ² are each independently substituted or unsubstituted. And an aryl group having 6 to 30 carbon atoms.) The stilbene derivative according to claim 1, wherein A in the general formula (1) is a carbocyclic structure or a heterocyclic structure represented by the following formula (2).

A plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ^{6 in the} general formula (1) are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; The stilbene derivative according to claim 1 or 2, characterized in that A method for producing a stilbene derivative represented by the following general formula (1) represented by the following reaction formula (1), wherein the formylated triphenylamine derivative represented by the general formula (3) and the general formula (4) A method for producing a stilbene derivative, comprising reacting a diphosphate derivative represented by the present invention in the presence of a base.

(A in Reaction Formula (1) is a divalent organic group containing a substituted or unsubstituted polycyclic aromatic ring having 10 to 30 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ^4. , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted Or an unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, and a plurality of Ar ¹ and Ar ² are each independently substituted or unsubstituted. And an aryl group having 6 to 30 carbon atoms.) As the formylated triphenylamine derivative represented by the general formula (3), a two-stage Vilsmeier method and a Wittig reaction using an aniline derivative represented by the following general formula (5) as a raw material The method for producing a stilbene derivative according to claim 4, wherein the formylated triphenylamine derivative obtained by the method is used.

(R ¹ and R ² in the general formula (5) are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon number 6 to 30 aryl groups, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, and substituted or unsubstituted halogenated alkyl groups having 1 to 20 carbon atoms.) An electrophotographic photosensitive member having a photosensitive layer provided on a conductive substrate, wherein the photosensitive layer contains a stilbene derivative represented by the following general formula (1).

(A in the general formula (1) is a divalent organic group containing a substituted or unsubstituted polycyclic aromatic ring having 10 to 30 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, substituted Or an unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, and a plurality of Ar ¹ and Ar ² are each independently substituted or unsubstituted. And an aryl group having 6 to 30 carbon atoms.)   The electrophotographic photosensitive member according to claim 6, wherein the photosensitive layer is a single layer type further containing a charge generating agent and an electron transporting agent.

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