JP2006028122A - Stilbene derivative, method for producing the same and electrophotographic receptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a stilbene derivative having excellent compatibility to a binder resin and a specific sensitivity by the presence of a prescribed substituent at a prescribed position of the molecule, to provide a method for producing the derivative and an electrophotographic receptor containing the stilbene derivative. <P>SOLUTION: This invention provides a stilbene derivative expressed by formula (1) (A is a specific aromatic ring structure; R<SP>1</SP>to R<SP>7</SP>are each hydrogen atom or a substituent such as a 1-20C substituted or unsubstituted alkyl (at least one of R<SP>1</SP>to R<SP>7</SP>is the substituent other than hydrogen atom); Ar<SP>1</SP>and Ar<SP>2</SP>are each a 6-30C aryl; the repeating numbers (a) and (b) are each an integer of 0-4; and (c) is an integer of 1-3), the method for producing the derivative and the electrophotographic receptor containing the stilbene derivative. The stilbene derivative is produced by reacting a formylated triphenylamine derivative with a diphosphoric acid ester derivative in the presence of a catalyst. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention contains a stilbene derivative that has excellent compatibility with a binder resin and has a predetermined sensitivity over a long period of time by having a specific substituent in the phenylamino group at the molecular end, a production method thereof, and a stilbene derivative. The present invention relates to an 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 (76) is known as a charge transfer agent having a high charge mobility (see, for example, Patent Document 1).

(In the above general formula (76), B, C, D, E, F and G represent a benzene ring which may have a substituent, and these may be bonded to each other to form a heterocyclic ring, X represents a divalent aromatic hydrocarbon residue which may have a substituent or a divalent heterocyclic compound residue which may have a substituent, and R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ is a hydrogen atom, a cyano group, a nitro group, a halogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a heterocyclic group which may have a substituent, respectively. Which may be the same or different from each other, n ₁ and n ₂ each represent an integer of 1 to 4, which may be the same or different from each other, and X ¹ and X ² are each Represents a group represented by the following general formula (77) and general formula (78), Each Re may be the same or different.)

(In the general formulas (77) and (78), n ₃ represents an integer of 0 to 4, n ₄ represents an integer of 1 to 4, and R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ are each a hydrogen atom, a cyano group, a nitro group, an alkyl group which may have a substituent, or an aryl group which may have a substituent. Or a heterocyclic group which may have a substituent, which may be the same or different from each other, and the pair consisting of R ¹⁵ and R ¹⁶ and the pair consisting of R ²⁰ and R ²¹ are condensed to form a carbocyclic ring; A group or a heterocyclic group may be formed, and when one of these pairs R is a hydrogen atom, the other is an aryl group or a heterocyclic group.)

  Moreover, a stilbene derivative represented by the following general formula (79) is known as a charge transport agent having a high charge mobility (see, for example, Patent Document 2).

(Y in the general formula (79) is a substituted or unsubstituted phenylene group, biphenylene group, naphthylene group, or an organic group represented by the following formula (80), and R ²² , R ²³ , R ²⁴ and R ²⁵ Is a substituted or unsubstituted aryl group, and R ²² , R ²³ , R ²⁴ and R ²⁵ may be bonded to each other, R ²⁶ and R ²⁷ are each a hydrogen atom, a substituted or unsubstituted alkyl group or Represents an aryl group.)

(Z in the general formula (80) is an oxygen atom, a sulfur atom, —CH═CH—, or an organic group represented by the following formula (81).)

(R ²⁸ and R ²⁹ in the general formula (81) are a hydrogen atom, an alkyl group or an aryl group, and R ²⁸ and R ²⁹ may be bonded to each other.)
JP 2000-66419 A (Claims) Japanese Patent Laid-Open No. 3-149560 (Claims)

Here, the stilbene derivative disclosed in Patent Document 1 is defined as having at least one alkyl group in the benzene rings B to G in the general formula (76). However, the stilbene derivatives described in the specific examples are divalent phenyl groups in which the central structure of the stilbene derivative has a bond at the para position, a divalent diphenyl group having a bond at the para position, or a divalent group. And the substituent on the benzene ring C is located at the meta or para position. For this reason, the specific example of the stilbene derivative disclosed in Patent Document 1 has a problem that the compatibility with the binder resin is poor, it is difficult to uniformly disperse in the photosensitive layer, and it is easy to crystallize when used for a long time. It was seen. That is, although the disclosed stilbene derivative initially has a high charge mobility, there has been a problem that the characteristics are not sufficiently exhibited when used for a long time as a charge transport agent on a photoreceptor. .
Furthermore, the stilbene derivative disclosed in JP-A No. 2000-133260 has a problem that its compatibility with the binder resin is poor because it does not have any substituent on the benzene ring of the triphenylamine structure at the molecular end. It was. Accordingly, there has been a problem that not only it is difficult to uniformly disperse in the photosensitive layer but also crystallization easily when used for a long time.

  Therefore, the present inventors, in a specific stilbene derivative, has a specific aromatic ring structure in the central structure, a predetermined aryl group via an ethenyl group and a predetermined substituent on the phenylamino group at the molecular end. By having at least one, the compatibility with the binder resin is excellent, and since it is uniformly dispersed in the photosensitive layer, the fact that it exhibits high charge mobility over a long period of time and effectively prevents crystallization is found. It was.

  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 an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are independent substituents, and each represents a hydrogen atom, a halogen atom, or carbon. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)

In constituting the stilbene derivative of the present invention, it is preferable that a plurality of Ar ¹ and Ar ^{2 in} the general formula (1) are substituted or unsubstituted aryl groups having 6 to 14 carbon atoms.

In constituting the stilbene derivative of the present invention, it is preferable that at least one of the plurality of R ^{1 to} R ^{7 in} the general formula (1) is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.

In constituting the stilbene derivative of the present invention, it is preferable that at least one of the plurality of R ^{1 to} R ^{5 in} the general formula (1) is a bonded carbocyclic structure having 3 to 6 carbon atoms.

  In constituting the stilbene derivative of the present invention, it is preferable that each of the plurality of repeating numbers c in the general formula (1) is 1.

  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 catalyst.

(A in the reaction formula (1) is an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are each an independent substituent, a hydrogen atom, a halogen atom, a carbon atom. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)

  Moreover, in implementing the manufacturing method of the stilbene derivative represented by General formula (1) of this invention, it represents with General formula (5) as a formylation triphenylamine derivative represented with General formula (3). It is preferable to use a formylated triphenylamine derivative obtained by a two-stage Vilsmeier method and a Wittig method using an aniline derivative as a raw material.

(R ^{1 to} R ⁵ 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 non-substituted group having 1 to 20 carbon atoms. A substituted halogenated alkyl group, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group, or a plurality of R ¹ to Any two of R ⁵ are each a carbocyclic structure formed by bonding or condensation.

  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 an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are independent substituents, and each represents a hydrogen atom, a halogen atom, or carbon. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)

  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 present invention, by including the stilbene derivative represented by the general formula (1), it is possible to provide an electrophotographic photoreceptor having excellent compatibility with the binder resin and having a predetermined sensitivity.
That is, the stilbene derivative represented by the general formula (1) has a specific aromatic ring structure and olefin group in the central structure, a predetermined aryl group via an olefin group and a phenylamino group at the molecular end, and a predetermined By having this substituent, steric hindrance is caused, so that the compatibility with the binder resin is excellent, and the charge mobility is high and crystallization can be effectively prevented over a long period of time.
Therefore, by using such a stilbene derivative as a charge transport agent (hole transport agent) in an electrophotographic photoreceptor, an electrophotographic photoreceptor having excellent sensitivity characteristics and durability over a long period of time can be provided. it can.

Moreover, according to the stilbene derivative of the present invention, Ar ¹ and Ar ² in the general formula (1) are aryl groups having 6 to 14 carbon atoms, so that intramolecular conjugation is widened and charge mobility is excellent. Has characteristics.
Therefore, by using such a stilbene derivative as a charge transport agent (hole transport agent) in an electrophotographic photoreceptor, an electrophotographic photoreceptor having excellent sensitivity characteristics can be provided. In addition, since such a structure is relatively easy to introduce, a predetermined stilbene derivative can be produced in a relatively high yield.

Further, according to the stilbene derivative of the present invention, at least one of R ^{1 to} R ^{7 in} the general formula (1) is a predetermined alkyl group, so that the compatibility with the binder resin is further improved. In addition, the charge mobility is high over a long period of time, and crystallization is more effectively prevented.
Accordingly, by using such a stilbene derivative as a charge transport agent (hole transport agent) in an electrophotographic photoreceptor, an electrophotographic photoreceptor having better sensitivity characteristics and durability over a long period of time is provided. Can do. In addition, such a substituent is relatively easy to introduce, and a predetermined stilbene derivative can be produced in a relatively high yield.

Further, according to the stilbene derivative of the present invention, any two of the plurality of R ^{1 to} R ^{5 in} the general formula (1) are each a bonded carbocyclic structure having 3 to 6 carbon atoms. The inner conjugation spreads and the charge mobility is excellent.
That is, by using such a stilbene derivative as a charge transfer agent (hole transfer agent) in an electrophotographic photoreceptor, an electrophotographic photoreceptor having excellent sensitivity characteristics can be provided. In addition, since such a structure is relatively easy to introduce, a predetermined stilbene derivative can be produced in a relatively high yield.

In addition, according to the stilbene derivative of the present invention, when the plurality of repeating numbers c in the general formula (1) are each 1, the compatibility with the binder resin is excellent.
That is, since such a stilbene derivative is used as a charge transport agent (hole transport agent) in an electrophotographic photoreceptor, it is uniformly dispersed in the photosensitive layer, so that it has excellent sensitivity characteristics and durability. A photographic photoreceptor can be provided. In addition, such a substituent is relatively easy to introduce, and a predetermined stilbene derivative can be produced in a relatively high yield.

  Moreover, according to the method for producing a stilbene derivative of the present invention, the presence of a catalyst is obtained by combining a formylated triphenylamine derivative represented by the general formula (3) and a diphosphate ester derivative represented by the general formula (4). By reacting below, a stilbene derivative represented by the general formula (1) is produced, which is excellent in compatibility with the binder resin, exhibits high charge mobility over a long period of time, and effectively prevents crystallization. The predetermined stilbene derivative that can be obtained can be obtained in high yield.

  In addition, according to the method for producing a stilbene derivative of the present invention, as the formylated triphenylamine derivative represented by the general formula (3), the aniline derivative represented by the general formula (5) is used as a raw material, and two steps By using the compound obtained by the Vilsmeier method and the Wittig reaction, a formylated triphenylamine derivative having a predetermined structure is efficiently obtained. As a result, the compound represented by the general formula (1) is obtained. The obtained stilbene derivative can be obtained more efficiently.

  Further, an electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, wherein the photosensitive layer contains a stilbene derivative represented by the general formula (1), so that the compatibility with the binder resin is excellent, It has a high charge mobility and can provide characteristics of effectively preventing crystallization. That is, an electrophotographic photoreceptor having excellent sensitivity characteristics and durability over a long time can be obtained.

  In addition, since the photosensitive layer is a single layer type further containing a charge generating agent and an electron transporting agent, a single layer type electrophotographic photosensitive member having a predetermined sensitivity can be obtained even though the configuration and production are easy. Obtainable.

  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).

(A in the general formula (1) is an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are independent substituents, and each represents a hydrogen atom, a halogen atom, or carbon. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)

In constituting the stilbene derivative of the present invention, at least one of R ^{1 to} R ^{7 in} the general formula (1) is preferably a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.
The reason for this is that at least one of R ^{1 to} R ^{7 in} the general formula (1) is a predetermined alkyl group, so that the planarity of the hole transport agent is lowered due to steric hindrance, and the crystal is more effectively crystallized. This is to prevent the conversion. Further, this is because the compatibility with the binder resin is further excellent, and since it is uniformly dispersed in the photosensitive layer, it is possible to provide an effect of excellent sensitivity characteristics over a long period of time.

Specific examples of the phenyl group having the general formula (1) a plurality of substituents R ¹ to R ⁵ in, and a phenyl group represented by the following formula (6). In order to clarify the bonding state, nitrogen atoms are also shown.

  Here, as an example of the stilbene derivative represented by the general formula (1), stilbene derivatives (HTM-A to O) represented by the following formulas (7) to (21) are shown. In addition, IR charts of stilbene derivatives (HTM-A, E, F, I, J) represented by formulas (7), (11), (12), (15) and (16) are shown in FIGS. Each is shown.

[Second Embodiment]
The second embodiment is a method for producing a stilbene derivative represented by the general formula (1) described in the first embodiment. As shown in the following reaction formula (1), the following general formula (3) And a diphosphate derivative represented by the formula (4) in the presence of a catalyst, and a method for producing a stilbene derivative.
In the reaction formula (1), A, R ^{1 to} R ⁷ , Ar ¹ , Ar ² , a, b, and c are as described above unless otherwise specified.

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-stage 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), A, R ^{1 to} R ⁷ , Ar ¹ , Ar ² , a and b are A, R ^{1 to} R ⁷ , Ar in the reaction formula (1) unless otherwise specified. ¹ , Ar ² , a and b are the same.

(2) First Step First, an aniline derivative represented by the general formula (5) is used as a raw material, to which two kinds of iodobenzene derivatives represented by the general formulas (22) and (23) are reacted, After obtaining the triphenylamine derivative represented by the general formula (24), it is formylated by the first-stage Vilsmeier method to synthesize the formylated triphenylamine derivative represented by the general formula (25). To do.
In synthesizing the triphenylamine derivative represented by the general formula (24), 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 (24), the aniline derivative represented by the general formula (5) and the two types represented by the general formulas (22) and (23) are used. The addition ratio with the iodobenzene derivative (total amount) is preferably set to a value in the range of 1: 2 to 1:20 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: 2, 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 1:20, 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 (22) and (23) 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 represented by the general formulas (22) and (23), the reaction temperature is usually in the range of 160 to 260 ° C. The reaction time is preferably set to a value within the range of 2 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 (24), 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 less, and the reaction time is preferably set to a value in the range of 5 to 240 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 (27) is synthesized by a Wittig reaction. That is, it reacts with the presence of formylated triphenylamine derivative represented by the general formula (25), phosphorus ylide derivative represented by the formula (26), n-butyllithium as a catalyst, and the like.

Here, the addition ratio of the formylated triphenylamine derivative represented by the general formula (25) and the phosphorus ylide derivative represented by the formula (26) 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 (27) 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 derivative exceeds 1: 3, a large amount of unreacted phosphorus ylide derivative remains, so the triphenylamine derivative represented by the general formula (27) This is because it may be difficult to purify.
Therefore, the addition ratio of the formylated triphenylamine derivative represented by the general formula (25) and the phosphorus ylide derivative represented by the formula (26) 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 (25) and the phosphorus ylide derivative represented by the formula (26) are reacted, the reaction temperature is usually a value within the range of −30 to 20 ° C. In addition, the reaction temperature 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 (27) 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. Diphosphate ester derivative Next, a method for synthesizing the diphosphate ester derivative represented by the general formula (4) as a raw material for carrying out the reaction formula (1) will be described in detail.
The diphosphate ester derivative represented by the general formula (4) can be synthesized as shown in the following reaction formula (3). In the reaction formula (3), A has the same contents as A in the general formula (1), and X is a halogen atom, for example, a chlorine atom or a bromine atom.

In carrying out the synthesis reaction of such a diphosphate derivative, for example, it is preferable to react trimethyl phosphite without solvent or in a suitable solvent with respect to the methyl halide derivative. 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 ratio of triethyl phosphite to be used is preferably at least 2 moles relative to 1 mole of the methyl halide derivative, and the value is within the range of 2 to 10 moles. 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 2 to 10 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 based on the reaction conditions described later according to the above-described 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 derivative represented by the general formula (4) is usually at −10 to 30 ° C. Preferably, the reaction time is set to a value within the range of 1 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) Catalyst The catalyst used for the 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 catalyst 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 catalyst 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 catalyst added exceeds 1.5 moles, the formylation 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. 6A, 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, since the obtained single-layer type photoreceptor contains the stilbene derivative represented by the general formula (1), the residual potential is lowered and it has a predetermined sensitivity.
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 As the charge generator used in the present invention, for example, metal-free phthalocyanine, oxotitanyl phthalocyanine, perylene pigment, bisazo pigment, dithioketopyrrolopyrrole pigment, metal-free naphthalocyanine pigment, metal naphthalocyanine pigment, Examples thereof include one or a combination of two or more of squaraine pigment, trisazo pigment, indigo pigment, azurenium pigment, cyanine pigment and the like.
In particular, image forming apparatuses of digital optical systems such as laser beam printers and facsimiles using a light source such as a semiconductor laser require a photosensitive member having a sensitivity in a wavelength region of 700 nm or more. For example, metal-free phthalocyanine, A phthalocyanine pigment such as oxotitanyl phthalocyanine is preferably used.
On the other hand, an analog optical image forming apparatus such as an electrostatic copying machine using a white light source such as a halogen lamp requires a photosensitive member having sensitivity in the visible region. For example, a perylene pigment or a bisazo pigment is used. Etc. are preferably used.

(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 hole transporting agents include various compounds having high hole transporting ability, for example, compounds represented by the following formulas (29) to (41) (HTM-1 to HTM-13).

(Wherein R ^h1 , R ^h2 , R ^h3 , R ^h4 , R ^h5 and R ^h6 are independent of each other, and are a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, substituted or An unsubstituted aryl group having 6 to 40 carbon atoms, a and b are the same or different integers of 0 to 4, and c, d, e and f are the same or different 0 Represents an integer of ˜5, provided that 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 independent of each other, and are a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted group, An aryl group having 6 to 40 carbon atoms, wherein g, h, i and j represent the same or different integers of 0 to 5 and k represents an integer of 0 to 4, provided that g, h , I, 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 independent of each other, substituted or unsubstituted alkyl or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted C 6 to 40 carbon ^{Represents an} aryl group, and R ^h16 represents a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms. M, n, o and p represent the same or different integers of 0 to 5, and q represents an integer of 0 to 6, provided that m, n, o, p or q is 2 or more. when 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 independent of each other, and are a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon number of 6; Represents an aryl group of ˜40, r, s, t, and u represent the same or different integers 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.)

(In the formula, R ^h21 and R ^h22 are independent of each other and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms or an alkoxy group. R ^h23 , R ^h24 , R ^h25 and R ^h26 are independent of each other. And represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 40 carbon atoms.)

(In the formula, R ^h27 , R ^h28 and R ^h29 are independent of each other and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms or an alkoxy group.)

(In the formula, R ^h30 , R ^h31 , R ^h32 and R ^h33 are independent of each other and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms or an alkoxy group.)

(In the formula, R ^h34 , R ^h35 , R ^h36 , R ^h37 and R ^h38 are independent of each other and represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms or an alkoxy group.)

(In the formula, R ^h39 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ^h40 , R ^h41 and R ^h42 are independent of each other; a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms; Or an alkoxy group.)

(Wherein, R ^h43, R ^h44 and R ^h45 are independent of each other, represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group having 1 to 20 carbon atoms.)

(In the formula, R ^h46 and R ^h47 are independent of each other, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted carbon atom having 6 to 6 carbon atoms. 40 aryl groups are shown.)

(In the formula, R ^h50 , R ^h51 , R ^h52 , R ^h53 , R ^h54 and R ^h55 are independent of each other, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or an alkoxy group. Or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, α represents an integer of 1 to 10, and v, w, x, y, z and β may be the same or different. Represents an integer of 0 to 2, provided that when v, 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 each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, and Φ is It is a group represented by any one of the formula (44).)

  Further, in the present invention, together with the above-exemplified hole transport agents HTM-1 to HTM-13, etc., a conventionally known hole transport material, 2,5-di (4-methylaminophenyl) -1,3,4 Oxadiazole compounds such as oxadiazole, styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds, 1-phenyl-3- (p-dimethylamino) Pyrazoline compounds such as phenyl) pyrazoline, hydrazone compounds, triphenylamine compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds Nitrogen-containing cyclic compounds such as compounds, Singly or in combinations of two or more such engagement polycyclic compounds.

(4) Electron Transfer Agent As the electron transfer agent used in the present invention, various compounds having high electron transport ability, for example, compounds represented by the following general formulas (43) to (59) (ETM-1 to ETM- 17).

(Wherein R ^e1 , R ^e2 , R ^e3 , R ^e4 and R ^e5 are independent of each other, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, substituted or An unsubstituted aryl group having 6 to 40 carbon atoms or an aralkyl group, or a substituted or unsubstituted phenoxy group.

(In the formula, R ^e6 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, R ^e7 is a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted carbon group having 6 to 6 carbon atoms. 40 represents an aryl group or an aralkyl group, a halogen atom, or a halogenated alkyl group, and γ represents an integer of 0 to 5. However, when γ is 2 or more, each R ^e7 may be different from each other. )

(In the formula, R ^e8 and R ^e9 are independent of each other, and represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. Δ represents an integer of 1 to 4, and ε represents an integer of 0 to 4. (However, when δ and ε are 2 or more, each R ^e8 and R ^e9 may be different.)

( ^Wherein R ^e10 represents a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group or aralkyl group having 6 to 40 carbon atoms, a halogenated alkyl group, or a halogen atom. Ζ represents an integer of 0 to 4, and η represents an integer of 0 to 5. However, when η is 2 or more, each R ^e10 may be different.)

(In the formula, R ^e11 represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and σ represents an integer of 1 to 4. However, when σ is 2 or more, each R ^e11 may be different. good.)

( ^Wherein R ^e12 and R ^e13 are independent of each other, a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon group having 6 to 40 carbon atoms) An aryl group, an aralkyloxycarbonyl group, a hydroxyl group, a nitro group, or a cyano group, and X represents an oxygen atom, = N-CN group, or = C (CN) ₂ group.

( ^Wherein R ^e14 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and R ^e15 represents a halogen ^atom. An atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, an alkoxycarbonyl group, an N-alkylcarbamoyl group, a cyano group, or a nitro group is represented. ^Represents an integer of 0 to 3. However, when λ is 2 or more, each ^{Re 15} may be different from each other.

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

(In the formula, R ^e16 and R ^e17 are independent of each other, and represent a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a cyano group, a nitro group, or an alkoxycarbonyl group. Represents an integer of ˜3, provided that when ν or ξ is 2 or more, R ^e16 and R ^e17 may be different from each other.

(In the formula, R ^e18 and R ^e19 are independent of each other, and represent a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, a condensed polycyclic group or a heterocyclic group, and these groups represent a substituent. You may have.)

( ^Wherein R ^e20 represents an amino group, a dialkylamino group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or an alkoxy group, or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, and π represents ^Represents an integer of 1 to 2. However, when π is 2, each ^{Re 20} may be different from each other.

(In the formula, R ^e21 represents a hydrogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group or aralkyl group having 6 to 40 carbon atoms.)

( ^Wherein R ^e22 represents a halogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group or aralkyl group having 6 to 40 carbon atoms, an alkoxycarbonyl group, N -Represents an alkylcarbamoyl group, a cyano group, or a nitro group, and μ represents an integer of 0 to 3. However, when μ is 2 or more, each ^{Re 22} may be different from each other.

(Wherein, R ^e23 represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms having 1 to 20 carbon atoms, R ^e24 represents a substituted or unsubstituted C 1 -C 20 alkyl group or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms or a group represented by -O-R ^e24,. R ^e24 in the above groups, the above-described substituted or unsubstituted carbon Represents an alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group having 6 to 40 carbon atoms.)

(In the formula, R ^e25 , R ^e26 , R ^e27 , R ^e28 , R ^e29 , R ^e30 and R ^e31 are independent of each other, and are substituted or unsubstituted alkyl or alkoxy groups having 1 to 20 carbon atoms, substituted or An unsubstituted aryl group having 6 to 40 carbon atoms or an aralkyl group, a halogen atom, or a halogenated alkyl group, and χ and φ are the same or different integers of 0 to 4.

( ^Wherein R ^e32 and R ^e33 are independent of each other, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, a halogen atom, Or a halogenated alkyl group, wherein τ and Ψ are the same or different and represent an integer of 0 to 4.)

( ^Wherein R ^e34 , R ^e35 , R ^e36 and R ^e37 are independent of each other, and are a hydrogen atom, a substituted or unsubstituted alkyl group or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted carbon number of 6; An aryl group, an aralkyl group, a cycloalkyl group or an amino group of ^˜40 , ^provided that at least two of R ^e34 , R ^e35 , R ^e36 and R ^e37 are the same group which is not a hydrogen atom.

  In addition to the above examples, in the present invention, conventionally known electron transport materials, for example, benzoquinone compounds, malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, etc. , Dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, dibromomaleic anhydride, etc., alone or in combination.

(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, as shown in FIG. 6B, with respect to the single-layer configuration, a photosensitive layer in which a barrier layer 16 is formed between the conductive substrate 12 and the photosensitive layer 14 within a range that does not impair the characteristics of the photosensitive member. The body 10 'may be used. Further, as shown in FIG. 6C, a photosensitive member 10 ″ having a protective layer 18 formed on the surface of the photosensitive layer 14 may be used.

(9) Manufacturing Method The manufacturing method of the electrophotographic photosensitive member of the present invention is not particularly limited, but it is preferable to prepare a coating solution first. Then, the obtained coating solution is applied, for example, on a conductive base material (aluminum base tube) by a dip coating method according to a known production method, and dried with hot air at 100 ° C. for 30 minutes. Thus, an electrophotographic photosensitive member having a photosensitive layer having a predetermined thickness can be obtained.
In addition, as a solvent for making such a 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. Aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; Ketones such as acetone, methyl ethyl ketone, and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformaldehyde, dimethylformamide, dimethylsulfoxy 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. 7A, 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, as shown in FIG. 7B, a photoreceptor 20 ′ in which a charge transport layer 22 is formed on a conductive substrate 12 and a charge generation layer 24 is formed thereon is also provided. Good.
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 Stilbene Derivative (1) -1 Synthesis of Triphenylamine Derivative Synthesis of a triphenylamine derivative represented by the following formula (61) was carried out according to the following reaction formula (4).
That is, 152.0 g (1.10 mol) of anhydrous potassium carbonate and 9.5 g (0.15 mol) of anhydrous copper carbonate were added into a two-necked flask having a volume of 500 ml, heated for 2 hours, and stirred until uniform. . Next, after cooling to room temperature, 67.6 g (0.5 mol) of an aniline compound represented by the following formula (60) and 305.9 g (1.5 mol) of iodobenzene were added, and then reheated to 220 ° C. And allowed to react for 2.5 hours. Then, after cooling to room temperature, 100 ml of toluene was added and filtered. The obtained residue was dissolved in toluene and dried using activated clay. Thereafter, the residue was dissolved in toluene, and methanol was further added for crystallization. Thereafter, the obtained crystals were filtered off and dried. Thereafter, the obtained crystals were purified using silica gel column chromatography (developing solvent: chloroform / hexane solvent) to obtain 84.1 g of a triphenylamine derivative represented by the formula (61) (yield: 58. 5%).

(1) -2 Synthesis of Formylated Triphenylamine Derivative Next, a formylated triphenylamine derivative represented by the formula (62) was synthesized according to the following reaction formula (5).
That is, in a 500 ml flask, 60 g (0.21 mol) of a triphenylamine derivative represented by the formula (61), 450 ml of dimethylformamide (DMF), 41.8 g (0.27 mol) of oxychlorophosphoric acid, And stirred at 85 ° C. or higher for 3 hours. After the reaction, the reaction solution was dropped into 600 ml of ion-exchanged water, and the precipitated solid was filtered off. The obtained solid was stirred and washed with ion exchange water. Thereafter, the solid was dissolved in toluene, and the organic layer was washed 5 times with ion-exchanged water. Thereafter, the obtained organic layer was dried and adsorbed by adding anhydrous sodium sulfate and activated clay. Thereafter, toluene was distilled off under reduced pressure, and the residue was dissolved in 200 ml of toluene and crystallized from methanol to obtain 50.2 g of a formylated triphenylamine derivative represented by the formula (62) (yield 75.8). %).

(1) -3 Synthesis of phosphorus ylide Subsequently, the synthesis of phosphorus ylide represented by the formula (63) was carried out according to the following reaction formula (6).
That is, 150 g (0.61 mol) of α-bromodiphenylmethane and 121 g (0.72 mol) of triethanol phosphoric acid were added, heated at 210 ° C., and stirred for 1 hour. Then, after cooling to room temperature, purification was performed by vacuum distillation. The obtained residue was purified using silica gel column chromatography (developing solvent: ethyl acetate solvent) to obtain 168.4 g of phosphorus ylide represented by the formula (63) (yield 90.7%).

(1) -4 Synthesis of Triphenylamine Derivative Next, a triphenylamine derivative represented by the following formula (64) was synthesized according to the following reaction formula (7).
That is, after adding 25 g (0.082 mol) of phosphorus ylide represented by the formula (63) into a 1000 ml four-necked flask, argon gas replacement was performed, and further 100 ml of THF was accommodated and reacted at 5 ° C. or lower. It was. Thereafter, 51.2 ml of n-BuLi (1.6M in hexane solution) was added dropwise, and the mixture was stirred at 7 ° C. or lower for 30 minutes. Furthermore, what melt | dissolved 18 g (0.057 mol) of the formylation triphenylamine derivative represented by Formula (62) in 45 ml of THF was dripped, and it stirred for 30 minutes at 6 degrees C or less. 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 and adsorbed with anhydrous magnesium sulfate and activated clay. Thereafter, the organic solvent was distilled off, left at room temperature for 2 days, the precipitated solid was filtered off using petroleum ether, and the obtained solid was dried under reduced pressure. The obtained solid was purified by column chromatography (developing solvent: chloroform / hexane solvent) to obtain 22.9 g of a triphenylamine derivative represented by the formula (64) (yield: 86.3%). ).

(1) -5 Synthesis of Formylated Triphenylamine Derivative Next, a formylated triphenylamine derivative represented by the following formula (65) was carried out according to the following reaction formula (8).
That is, in a 500 ml flask, 20 g (0.043 mol) of the triphenylamine derivative represented by the formula (64), 300 ml of dimethylformamide (DMF), 8.6 g (0.06 mol) of oxychlorophosphoric acid, And stirred at 95 ° C. for 3 hours. Thereafter, the reaction solution was poured into 500 ml of ion-exchanged water, and the precipitated crystals were separated by filtration. The obtained solid was stirred and washed twice with ion-exchanged water. Furthermore, the obtained crystal | crystallization was dissolved in toluene, and the organic layer was wash | cleaned 5 times using ion-exchange water. Further, anhydrous magnesium sulfate and activated clay were added to the organic layer, and after drying and adsorption treatment, the solvent was distilled off under reduced pressure. The obtained residue was purified by silica gel column chromatography (developing solvent: chloroform solvent) to obtain 16.6 g of a formylated triphenylamine derivative represented by the formula (65) (yield 78.2%).

(1) -6 Synthesis of Diphosphate Derivative Derivative The synthesis of the diphosphate derivative represented by formula (66) was synthesized according to the following reaction formula (9). That is, 80 g (0.457 mol) of 1,3-bis (chloromethyl) benzene and 228 g (1.37 mol) of triethyl phosphite were accommodated in a 500 ml flask and refluxed for 8 hours or more. Then, it cooled and the precipitated crystal was separated by filtration. Furthermore, the crystal was washed with n-hexane to obtain a diphosphate ester derivative (146) g represented by the formula (66) (yield 84.7%).

(1) -7 Synthesis of Stilbene Derivative Next, a stilbene derivative represented by the formula (7) was synthesized according to the following reaction formula (10).
That is, in a 500 ml two-necked flask, 4.47 g (0.0118 mol) of the diphosphate ester represented by the formula (66) obtained in (1) -6 was added and purged with argon. , NaOMe 5.48 g (0.0284 mol) / THF 30 ml were accommodated and stirred for 30 minutes. Next, 14 g (0.0284 mol) of the formylated triphenylamine derivative represented by the above formula (65) was dissolved in this container, and then stirred at room temperature for about 12 hours. Next, the reaction solution was poured into 500 ml of ion-exchanged water, and the aqueous layer was changed from neutral to weakly acidic with dilute hydrochloric acid. Furthermore, toluene extraction was performed and the organic layer was washed 5 times with ion exchange water. Thereafter, the organic layer was dried over anhydrous magnesium sulfate, and the solvent was distilled off. The obtained residue was purified by silica gel chromatography (developing solvent: chloroform / hexane) to obtain 7.81 g of a stilbene derivative represented by the formula (6) (yield 62.6%).

(2) Evaluation (2) -1 Measurement of Initial Surface Potential, Half-Exposure Exposure and Residual Potential 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 and residual potential were measured. That is, 60 parts by weight of the obtained stilbene derivative (HTM-A) as a hole transport agent and 5 X-type metal-free phthalocyanine (CGM-A) represented by the following formula (67) as a charge generator. 100 parts by weight of polycarbonate resin (Resin-A) represented by the following formula (68) as a binder resin and 800 parts by weight of tetrahydrofuran as a solvent were added. 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.
Next, initial electrical characteristics of the obtained electrophotographic photosensitive member, that is, initial charging potential (V ₀ ) half-exposure amount (E _1/2 ) and residual potential (V _R ) were measured. First, using a drum sensitivity tester (manufactured by GENTEC), the surface potential was charged to 710V. The half-exposure amount (E _1/2 ) was monochromatic light having a wavelength of 780 nm (half-value width: 20 nm) taken out from the light of the halogen lamp using a bandpass filter after charging so that the surface potential was 710 V. , Light intensity: 1.5 μJ / cm ² ), and the time required for the surface potential to be ½ was measured. Further, regarding the residual potential (V _R ), the surface potential at the time when 330 msec had elapsed from the start of exposure was measured, and this was defined as the residual potential.
The obtained results are shown in Table 1.

(2) -2 Crystallinity Evaluation Further, after applying the photosensitive layer, the appearance of the electrophotographic photosensitive member naturally dried for 1 hour before hot air drying was visually observed, and crystallinity was evaluated according to the following criteria. The obtained results are shown in Table 1.
(Double-circle): Crystallization is not seen at all.
○: Crystallization is hardly observed.
Δ: Slight crystallization is observed.
X: Remarkable crystallization is observed.

(2) -3 Repeated Charging Characteristic Evaluation In addition, the electrophotographic photosensitive member prepared in (2) -1 is mounted on an electrostatic printer (FS-1000 + modified machine manufactured by Kyocera Corporation), and the surface potential is reduced to about It was set to 450V. Thereafter, after continuous printing of 5000 sheets, the surface potential was measured again to obtain the surface potential after printing. The difference between the obtained post-printing surface potential and the initial measured value of 450 V was defined as the amount of change in charge. The obtained results are shown in Table 1.

[Example 2]
Single layer type photosensitivity in the same manner as in Example 1, except that 30 parts by weight of a quinone derivative (ETM-A) represented by the following formula (69) was further added as an electron transport material in the coating liquid of Example 1. Layers were created and evaluated.

[Example 3]
Single layer as in Example 1 except that another 30 parts by weight of another quinone derivative (ETM-B) represented by the following formula (70) was added as an electron transporting material to the coating liquid in Example 1. A mold photosensitive layer was prepared and evaluated.

[Example 4]
A single layer as in Example 1 except that another 30 parts by weight of another quinone derivative (ETM-C) represented by the following formula (71) was added as an electron transporting material to the coating liquid in Example 1. A mold photosensitive layer was prepared and evaluated.

[Examples 5 to 8]
Instead of the stilbene derivative (HTM-A) in Examples 1 to 4, Examples 1 to 4 were used except that the stilbene derivative (HTM-B) represented by the formula (8) was used as the hole transport material. Similarly, a single-layer type photosensitive layer was prepared and evaluated.

[Examples 9 to 12]
Instead of the stilbene derivative (HTM-A) in Examples 1 to 4, Examples 1 to 4 were used except that the stilbene derivative (HTM-C) represented by the formula (9) was used as the hole transport material. Similarly, a single-layer type photosensitive layer was prepared and evaluated.

[Example 13]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, the stilbene derivative (HTM-D) represented by the formula (10) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 14]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-E) represented by the formula (11) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 15]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, the stilbene derivative (HTM-F) represented by the formula (12) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 16]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, the stilbene derivative (HTM-G) represented by the formula (13) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 17]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-H) represented by the formula (14) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 18]
A single layer type as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-I) represented by the formula (15) was used as a hole transport agent. Photoconductors were created and evaluated.

[Example 19]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-K) represented by the formula (17) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Example 20]
A single layer type as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-L) represented by the formula (18) was used as a hole transport agent. Photoconductors were created and evaluated.

[Example 21]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-P) represented by the following formula (72) was used as a hole transport agent. Type photoreceptors were prepared and evaluated.
As a result, it was confirmed that the compatibility with the binder resin was excellent as in Example 2, the residual potential was low, and the amount of change in charge was small even when used for a long time.

[Comparative Examples 1-4]
Examples 1-4 except that the stilbene derivative (HTM-Q) represented by the following formula (73) was used as the hole transport material instead of the stilbene derivative (HTM-A) in Examples 1-4. A single-layer type photosensitive layer was prepared and evaluated in the same manner as described above.

[Comparative Examples 5 to 8]
Examples 1-4 except that the stilbene derivative (HTM-R) represented by the following formula (74) was used as the hole transport material instead of the stilbene derivative (HTM-A) in Examples 1-4. A single-layer type photosensitive layer was prepared and evaluated in the same manner as described above.

[Comparative Example 12]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, a stilbene derivative (HTM-S) represented by the formula (75) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

[Comparative Example 12]
A single layer as in Example 1 except that instead of the stilbene derivative (HTM-A) in Example 2, the stilbene derivative (HTM-T) represented by the formula (76) was used as the hole transport agent. Type photoreceptors were prepared and evaluated.

As described above in detail, the stilbene derivative of the present invention has a specific aromatic ring structure at the center, a predetermined aryl group via an olefin group at the molecular end, and at least one predetermined substituent. For this reason, it has excellent compatibility with the binder resin and has high charge transport ability (hole transport ability). That is, 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.
In addition, the method for producing a stilbene derivative of the present invention includes a high charge transporting agent having excellent compatibility with a binder resin by reacting a predetermined formylated triphenylamine derivative and a predetermined diphosphate derivative. The stilbene derivative represented by the general formula (1) having the ability can be obtained in a high yield.
Furthermore, since the electrophotographic photoreceptor of the present invention uses a stilbene derivative represented by the general formula (1) as a hole transport agent, it has predetermined sensitivity characteristics and durability. 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.

It is a figure provided in order to demonstrate the infrared spectroscopy (IR) chart of the stilbene derivative represented by Formula (7). It is a figure provided in order to demonstrate the infrared spectroscopy (IR) chart of the stilbene derivative represented by Formula (11). It is a figure provided in order to demonstrate the infrared spectroscopy (IR) chart of the stilbene derivative represented by Formula (12). It is a figure provided in order to demonstrate the infrared spectroscopy (IR) chart of the stilbene derivative represented by Formula (15). It is a figure provided in order to demonstrate the infrared spectroscopy (IR) chart of the stilbene derivative represented by Formula (16). (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.

Explanation of symbols

10: Single layer type photoreceptor 10 ': Single layer type photoreceptor 10 ": Single layer type photoreceptor 12: Conductive substrate 14: Photosensitive layer 16: Barrier layer 18: Protective layer 20: Multilayer type photoreceptor 20': Laminated photoreceptor 22: charge transport layer 24: charge generation layer

Claims (9)

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


(A in the general formula (1) is an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are independent substituents, and each represents a hydrogen atom, a halogen atom, or carbon. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)

^2. The stilbene derivative according to claim 1, wherein the plurality of Ar ¹ and Ar ² in the general formula (1) are substituted or unsubstituted aryl groups having 6 to 14 carbon atoms. At least one of the plurality of R ¹ to R ⁷ in the general formula (1) is, stilbene according to claim 1 or 2, characterized in that a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms Derivative. 4. The stilbene according to claim 1, wherein any two of the plurality of R ^{1 to} R ^{5 in} the general formula (1) are bonded C 3-6 carbocyclic structures. Derivative.   5. The stilbene derivative according to claim 1, wherein the plurality of repeating numbers c in the general formula (1) are each 1. 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 catalyst.

(A in the reaction formula (1) is an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are each an independent substituent, a hydrogen atom, a halogen atom, a carbon atom. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)
Two-stage Vilsmeier method and Wittig reaction using the aniline derivative represented by the following general formula (5) as a raw material as the formylated triphenylamine derivative represented by the general formula (3) The method for producing a stilbene derivative according to claim 6, wherein the formylated triphenylamine derivative obtained by the method is used.

(R ^{1 to} R ⁵ 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 non-substituted group having 1 to 20 carbon atoms. A substituted halogenated alkyl group, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group, or a plurality of R ¹ to Any two of R ⁵ are each a carbocyclic structure formed by bonding or condensation. 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 an organic group represented by the following formula (2), and a plurality of R ^{1 to} R ⁷ are independent substituents, and each represents a hydrogen atom, a halogen atom, or carbon. A substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted halogenated alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and a substitution having 6 to 30 carbon atoms Or an unsubstituted aryl group, a substituted or unsubstituted amino group, or any two of a plurality of R ^{1 to} R ⁷ each is a carbocyclic structure formed by bonding or condensation with each other, and a plurality of Ar ¹ and Ar ² are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, repeating numbers a and b are each an integer of 0 to 4, and c is an integer of 1 to 3 However, at least of R ^{1 to} R ⁷ The other is the above-mentioned substituent other than a hydrogen atom.)
  9. The electrophotographic photosensitive member according to claim 8, wherein the photosensitive layer is a single layer type further containing a charge generating agent and an electron transporting agent.