JP4555586B2 - Single layer type electrophotographic photoreceptor - Google Patents

Description

The present invention relates to a single layer type electrophotographic photosensitive member . In particular, the present invention relates to a single-layer electrophotographic photoreceptor containing an amine stilbene derivative having an organic group containing a substituted or unsubstituted nitrogen atom at a predetermined position in the molecule and having a predetermined sensitivity .

Conventionally, as an electrophotographic photosensitive member used for an image forming apparatus or the like, an organic photosensitive member made of an organic photosensitive material such as a charge transfer 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 organic photoreceptor materials, as a charge transfer agent having a predetermined charge mobility, a stilbene compound having a triphenylamine structure represented by the following general formula (47) and an electrophotographic photoreceptor using the stilbene compound are: It is known (see, for example, Patent Document 1).

(In the general formula (47), Z is ortho CH ₃ , meta CH ₃ , para CH ₃ , ortho Cl, meta Cl, or para Cl.)
JP 54-58445 (specification)

However, the stilbene compound described in Patent Document 1 has a problem in that the sensitivity is insufficient and the compatibility with the binder resin in the electrophotographic photosensitive member is poor.
Therefore, the present inventors have improved sensitivity and improved compatibility with the binder resin by introducing an organic group containing a substituted or unsubstituted nitrogen atom at a predetermined position in the molecule in the amine stilbene derivative. The present inventors have found the fact that they are excellent, and have completed the present invention.
That is, an object of the present invention is to provide a single-layer electrophotographic film containing an amine stilbene derivative that has excellent sensitivity and compatibility with a binder resin and can be suitably used as a hole transporting agent for an electrophotographic photosensitive member. The object is to provide a photoreceptor .

According to the present invention, an electrophotographic photoreceptor having a photoreceptor layer provided on a conductive substrate, the photoreceptor layer being a single layer type containing a hole transport agent, an electron transport agent and a charge generating agent. And a hole transport agent is an amine stilbene derivative represented by the following general formula (1), and the electron transport agent is a naphthoquinone derivative and / or a diphenoquinone derivative, or a single-layer electron A photographic photoreceptor is provided, which can solve the above-mentioned problems.

(In General Formula (1), A is a hydrazone group represented by the following General Formula (2), and a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms. And a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted by an independent methyl group .)

(In General Formula (2), X and Y are each independently an alkyl group having 1 to 2 carbon atoms, or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group .)

In constituting the single-layer electrophotographic photosensitive member of the present invention, the electron transport agent is preferably at least one selected from the group consisting of compounds represented by the following formulas (33) to (35).

In constituting the single-layer electrophotographic photosensitive member of the present invention, the charge generator is preferably a metal-free phthalocyanine represented by the following formula (14).

In constituting the single-layer electrophotographic photosensitive member of the present invention, the amine stilbene derivative is a method for producing an amine stilbene derivative represented by the following reaction formula (1), and is represented by the general formula (3). a formylated triphenylamine derivative, a hydrazine derivative represented by the general formula (4) is reacted in the presence of a catalyst, the general formula to give the amine stilbene derivatives represented by (1 ') of the amine stilbene derivatives It is preferable to be obtained by a manufacturing method .

(In the reaction formula (1), a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms, and a plurality of X and Y are each independently an independently having 1 to 2 carbon atoms. An alkyl group or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group, and a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted with an independent methyl group; is there.)

According to the amine stilbene derivative in the present invention, it is excellent in sensitivity by introducing a predetermined hydrazone group into a predetermined position in the molecule as represented by the general formula (1). , Excellent compatibility can be obtained.
In addition, when R ^{1 to} R ⁶ are each a predetermined substituent, production of a stilbene derivative having a predetermined structure is facilitated, and the stilbene derivative can be obtained stably.
Therefore, according to the single-layer electrophotographic photoreceptor of the present invention, the photoreceptor layer contains a predetermined amine stilbene derivative, so that it has excellent sensitivity and excellent compatibility with the binder resin. Obtainable.
In addition, according to the electrophotographic photosensitive member of the present invention, an electrophotographic photosensitive member having a predetermined sensitivity over a long period of time can be obtained by using a single-layer type photosensitive member, although it is easy to configure and manufacture. Can do.

In addition, according to the method for producing an amine stilbene derivative in the present invention, it is represented by the general formula (1 ′) by reacting a predetermined formylated triphenylamine derivative with a hydrazine derivative in the presence of a catalyst. An amine stilbene derivative can be obtained efficiently.

Hereinafter, embodiments relating to an amine stilbene derivative, a method for producing the same, and a single-layer electrophotographic photosensitive member according to the present invention will be specifically described with reference to the drawings as appropriate.

[First embodiment]
The first embodiment is an amine stilbene derivative represented by the following general formula (1), which is a hole transport agent in the single-layer electrophotographic photosensitive member of the present invention .

(In General Formula (1), A is a hydrazone group represented by the following General Formula (2), and a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms. And a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted by an independent methyl group .)

(In General Formula (2), X and Y are each independently an alkyl group having 1 to 2 carbon atoms, or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group .)

  Here, amine stilbene derivatives (HTM-A to C) represented by the following structural formulas (5) to (7) are shown as preferred examples of the amine stilbene derivative represented by the general formula (1).

[Second Embodiment]
In the second embodiment, as shown in the following reaction formula (1), a formylated triphenylamine derivative represented by the general formula (3) and a hydrazine derivative represented by the general formula (4) To obtain an amine stilbene derivative represented by the general formula (1 ′) , wherein the amine stilbene derivative is a hole transporting agent in the single-layer electrophotographic photoreceptor of the present invention. Is the method.

(In the reaction formula (1), a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms, and a plurality of X and Y are each independently an independently having 1 to 2 carbon atoms. An alkyl group or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group, and a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted with an independent methyl group; is there.)

1. Synthesis of Formylation Triphenylamine Derivative First, a method for synthesizing a formylation triphenylamine derivative represented by the general formula (3) as a raw material for carrying out the reaction formula (1) will be described in detail.
That is, the formylated triphenylamine derivative represented by the general formula (3) is formed by using the Vilsmeier method and the Wittig method as shown in the following reaction formula (2). It is preferable to synthesize including the fourth step. Incidentally, the reaction formula (2) a plurality of R ¹ ~R ^6, Ar ¹ and Ar ² in is the content already described, respectively. )

(1) First Step The first step is represented by the general formula (10) by reacting the aniline derivative represented by the general formula (8) with the iododiphenylbenzene derivative represented by the general formula (9). This is a step of producing a triphenylamine derivative.
In the first step, the reaction ratio of the aniline derivative represented by the general formula (8) and the iododiphenylbenzene derivative represented by the formula (9) is within a range of 2: 1 to 4: 1 by molar ratio. It is preferable to set the value of.
This is because when the reaction ratio between the aniline derivative and the iododiphenylbenzene derivative is less than 2: 1, the amount of the triphenylamine derivative that is the target product may be reduced. On the other hand, if the reaction ratio between the aniline derivative and the iododiphenylbenzene derivative exceeds 4: 1, a large amount of unreacted aniline derivative remains, which makes it difficult to purify the target triphenylamine derivative. Because there is.

In reacting the aniline derivative represented by the general formula (8) and the iododiphenylbenzene derivative represented by the general formula (9), the reaction temperature is usually set to a value within the range of 160 to 220 ° C. At the same time, the reaction temperature is preferably set to a value 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.

(2) Second Step In the second step, the formylated triphenylamine represented by the general formula (11) is obtained from the obtained triphenylamine derivative represented by the general formula (10) using the Vilsmeier method. This is a step of creating a derivative.
In the second step, it is preferable to use a combination of the following compounds (i) and (ii) as a Vilsmeier reagent.
(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, and in the present invention, as a Filsmeier reagent, phosphorus oxychloride, A combination with DMF that can also be used as a solvent is preferably used.

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.
Furthermore, with respect to the amount of the Filsmeier reagent used, it is preferably set to a value within the range of 1 to 20 moles per mole of the triphenylamine derivative represented by the general formula (10). It is more preferable to set the value within the range.
In addition, regarding the reaction conditions for the formylation of the triphenylamine derivative represented by the general formula (10) in the Vilsmeier method, the reaction is usually performed at a temperature of 130 ° C. or less, and the reaction time is a value within a range of 5 to 120 minutes. It is preferable to do.

(3) Third Step In the third step, the obtained formylated triphenylamine derivative represented by the general formula (11) is reacted with the phosphorus ylide derivative represented by the formula (12) using the Witchig method. In this step, the triphenylamine derivative represented by the general formula (13) is prepared.
Then, when the formylated triphenylamine derivative represented by the general formula (11) and the phosphorus ylide derivative represented by the formula (12) are reacted, the formylated triphenylamine derivative represented by the general formula (11) And the addition ratio with the phosphorus ylide derivative represented by Formula (12) is preferably set to a value in the range of 1: 2 to 1: 4 in terms of molar ratio.
This is because the amount of triphenylamine derivative represented by the general formula (13) is reduced when the addition ratio of the formylated triphenylamine derivative and the phosphorus ylide derivative is less than 1: 2. Because there is. On the other hand, when the addition ratio of the formylated triphenylamine derivative and the phosphorus ylide derivative exceeds 1: 4, a large amount of unreacted styryl derivative remains, so the triphenylamine derivative represented by the general formula (13) This is because it may be difficult to purify.

Further, when the formylated triphenylamine derivative represented by the general formula (11) and the phosphorus ylide derivative represented by the formula (12) 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.
In using the Witchhi method, the catalyst may be, for example, a sodium alkoxide such as sodium methoxide or sodium ethoxide, a metal hydride such as sodium hydride or potassium hydride, or a single metal salt such as n-butyllithium. A combination of two or more types can be mentioned.

(4) Fourth Step The fourth step is formylation represented by the general formula (3) from the obtained triphenylamine derivative represented by the general formula (13) using the second Filsmeier method. This is a step of creating a triphenylamine derivative.
That is, in using the second Vilsmeier method, the same conditions as in the first Vilsmeier method are adopted, and the formylated triphenylamine represented by the general formula (3) serving as a raw material in the reaction formula (1) Derivatives can be synthesized efficiently.

2. Reaction condition (1) Reaction temperature and reaction time The reaction of the formylated triphenylamine derivative represented by the general formula (3) with the hydrazine derivative represented by the general formula (4) is usually performed at room temperature to 100 The reaction is preferably performed at a temperature of 0 ° C., and the reaction time is preferably 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 hydrazine derivative represented by the general formula (4), the reaction is not affected. For example, 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 can be used.

(3) Catalyst The catalyst used for the reaction is preferably a sodium alkoxide such as sodium methoxide or sodium ethoxide, a metal hydride such as sodium hydride or potassium hydride, or zinc chloride. As mentioned.
Here, it is preferable to make the addition amount of this catalyst into the value within the range of 2-5 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 2 mol, it is between the formylated triphenylamine derivative represented by the general formula (3) and the hydrazine derivative represented by the general formula (4). This is because there is a case where the reactivity of is significantly reduced.
On the other hand, when the amount of the catalyst added exceeds 5 mol, the reaction between the formylated triphenylamine derivative represented by the general formula (3) and the hydrazine derivative represented by the general formula (4) is controlled. This is because it may be extremely difficult to do.

(4) Addition ratio In carrying out the reaction between the formylated triphenylamine derivative represented by the general formula (3) and the hydrazine derivative represented by the general formula (4), The value is preferably in the range of 1: 2 to 1: 5.
The reason for this is that when the addition ratio of the formylated triphenylamine derivative and the hydrazine derivative is less than 1: 2, an intermediate is easily formed, and the formylated triphenylamine derivative and the hydrazine derivative are separated from each other. This is because it may be difficult to respond appropriately. Further, when the addition ratio exceeds 1: 5, a large amount of unreacted formylated triphenylamine derivative remains, which may make purification difficult.
Therefore, the molar ratio of the addition ratio of the formylated triphenylamine derivative represented by the general formula (3) and the hydrazine derivative represented by the general formula (4) is 1: 2.2 to 1: 4. A value in the range of 5 is more preferable.

[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 is a single layer type containing a hole transporting agent, an electron transporting agent and a charge generating agent. In addition, the electron transporting agent is an amine stilbene derivative represented by the general formula (1), and the electron transporting agent is a naphthoquinone derivative and / or a diphenoquinone derivative, It is a photographic photoreceptor.
The electrophotographic photosensitive member of the present invention can be used particularly for any positive and negative charging type photosensitive member, has a simple structure, is easy to manufacture, and effectively suppresses coating defects when forming the photosensitive layer. The present invention is characterized by being applied to a single-layer type photoconductor for the reasons that it is possible to reduce the interface between layers and to easily improve the optical characteristics.

1. Single Layer Type Photoreceptor (1) Basic Configuration As shown in FIG. 1A, the single layer type photoreceptor 10 has a single photoreceptor layer 14 provided on a conductive substrate 12.
This photoreceptor layer is, for example, an amine stilbene derivative (hole transport agent) represented by the general formula (1), a charge generator, a binder resin, and an electron transport agent dissolved or dispersed in an appropriate solvent. Then, the obtained coating solution can be applied on a conductive substrate and dried. 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.

In addition, since the obtained single-layer type photoreceptor contains the amine stilbene derivative represented by the general formula (1), the residual potential is lowered and it has a predetermined sensitivity. is there.
Furthermore, by including an electron transport agent in the photoreceptor layer of the single-layer type photoreceptor, electrons can be efficiently transferred between the charge generating agent and the hole transport agent, and the sensitivity and the like are further stabilized. 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 (14) to (17). preferable.

  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, bisazo pigments and the like are preferably used.

Moreover, when using the compound (CGM-B) represented by the formula (15) among the charge generating agents used in the present invention, a dispersion aid represented by the following formula (18) (for example, C.I. 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 (18), 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) In the electrophotographic photoreceptor of the hole transfer agent present invention, together with an amine stilbene derivative in the present invention is a hole transporting material, it is also preferable that the other conventionally known hole transport material to be contained in the photosensitive layer .
As such a hole transport agent, various compounds having a high hole transport ability, for example, hole transport agents represented by the following general formulas (19) to (31) (HTM-1 to HTM-13) Is given.

Wherein R ^h1 , R ^h2 , R ^h3 , R ^h4 , R ^h5 and R ^h6 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. Represents a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, a and b represent the same or different integers of 0 to 4, and c, d, e and f are the same or different. Represents 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 are different. May be.)

(Wherein R ^h7 , R ^h8 , R ^h9 , R ^h10 and R ^h11 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, a substituted or An unsubstituted aryl group having 6 to 40 carbon atoms, g, h, i and j are the same or different integers of 0 to 5 and k is an integer of 0 to 4. When 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 hydrogen atom, 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 r, s, t and u are the same or different and represent an integer of 0 to 5, provided that 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.)

^Wherein R ^h50 , R ^h51 , R ^h52 , R ^h53 , R ^h54 and R ^h5 are independent of each other, and are a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1-20 alkyl group or 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. .)

(In the formula, R ^h56 , R ^h57 , R ^h58 and R ^h59 are independent of each other, and represent 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 of the formulas.)

  In the present invention, together with the above exemplified hole transport agents HTM-1 to HTM-13, 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-dimethylaminophenyl) ) Pyrazoline compounds such as 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 Singly or in combinations of two or more polycyclic compounds, and the like.

(4) Electron Transfer Agent (4) -1 Type As the type of electron transfer agent, a quinone derivative is preferably included. Examples thereof include naphthoquinone derivatives, diphenoquinone derivatives, azoquinone derivatives, and the like.
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.

(4) -2 Specific Example Further, specific examples of the electron transfer agent include compounds (ETM-A to ETM-C) represented by the following formulas (33) to (35).

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.

(2) Binder Resin (2) -1 Type As the binder resin for dispersing the charge generating agent, for example, polycarbonate resin such as bisphenol Z type, bisphenol ZC type, bisphenol C type, bisphenol A type, poly Arylate resin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorine Polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin Etc. One or a combination of two or more kinds of plastic resins, silicone resins, epoxy resins, phenol resins, urea resins, melamine resins, other cross-linkable thermosetting resins, epoxy acrylate, urethane acrylate, and other photo-curable resins. It can be used.

(6) Additive In addition to the above-mentioned components, the photoreceptor layer has various conventionally known additives such as an antioxidant, a radical scavenger, a singlet as long as the electrophotographic characteristics are not adversely affected. Deterioration inhibitors such as quenchers 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 photoreceptor layer, known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator.

(7) Mixing ratio 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 0.5 to 100 parts by weight of the binder resin. What is necessary is just to mix | blend in the ratio of -30 weight part. Further, the amine stilbene derivative (hole transport agent) represented by the general formula (1) of the present invention is 20 to 500 parts by weight, preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. What is necessary is just to mix | blend. 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. Furthermore, when the 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. It is.

  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. 10 to 500 parts by weight of the amine stilbene derivative (hole transport agent) represented by the general formula (1) of the present invention with respect to 100 parts by weight of the binder resin, It is suitable to mix | blend in the ratio of 25-200 resin. 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 The thickness of the photoreceptor layer in the single-layer photoreceptor is 5 to 100 μm, preferably 10 to 50 μm. As the conductive substrate on which such a photoreceptor layer is formed, various conductive materials can be used, for example, iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium. , Cadmium, titanium, nickel, palladium, indium, stainless steel, brass and the like, plastic materials on which the above metal is deposited or laminated, glass covered with aluminum iodide, tin oxide, indium oxide, etc. .
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 photoreceptor layer is formed by a coating method, the above-described charge generator, charge transport agent, binder resin and the like together with a suitable solvent, a known method such as a roll mill, a ball mill, an attritor, a paint shaker, What is necessary is just to disperse and mix using an ultrasonic disperser etc., to prepare a dispersion liquid, and to apply | coat this by a well-known means and to dry.
Further, regarding the configuration of the single-layer type photoreceptor 10, as shown in FIG. 1B, a barrier layer 16 is formed between the conductive substrate 12 and the photoreceptor layer 14 within a range that does not impair the characteristics of the photoreceptor. May be. Further, as shown in FIG. 1C, a protective layer 18 may be formed on the surface of the photoreceptor layer 14.

(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 surface of the photoreceptor layer.

[ Reference Example 1 ]
1. Synthesis of Amine Stilbene Derivative (1) First Step In the first step, along with the following reaction formula (3), an aniline derivative represented by formula (36) and iododiphenylbenzene represented by general formula (37) The derivative was reacted with to synthesize a triphenylamine derivative represented by the formula (38).
That is, 48.4 g (0.35 mol) of anhydrous potassium carbonate and 2.22 g (0.035 mol) of powdered copper were added into a two-necked flask having a capacity of 1000 ml, heated for 2 hours, and stirred until uniform. . Next, after cooling to room temperature, 60 g (0.35 mol) of the aniline derivative represented by formula (36), 65.4 g (0.16 mol) of diphenyliodobenzene represented by formula (37), and o-di After adding 100 ml of chlorobenzene, it was heated to 180 ° C. and reacted for 12 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 obtained crystal was purified using silica gel column chromatography (developing solvent: chloroform / hexane solvent) to obtain 54 g of a triphenylamine derivative represented by the formula (38) (yield 69%).

(2) Second Step In the second step, from the triphenylamine derivative represented by the formula (38) obtained according to the following reaction formula (4), using the Philsmeier method, the formula (39) The formylated triphenylamine derivative represented was synthesized.
That is, in a 500 ml flask, 45 g (0.092 mol) of the triphenylamine derivative represented by the formula (38), 200 ml of dimethylformamide (DMF), and 35.3 g of oxychlorophosphoric acid dissolved in 100 ml of dimethylformamide. (0.23 mol) and the mixture was reacted under stirring at 70 ° C. for 30 minutes. After the reaction, the reaction solution was dropped into a mixture consisting of 400 ml of ion exchange water and 200 ml of toluene, and the precipitated solid was separated by filtration. The obtained solid was stirred and washed with ion exchange water. Thereafter, the solid was dissolved in toluene, and the organic layer was washed 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 resulting residue was purified using silica gel column chromatography to obtain 42 g of a formylated triphenylamine derivative represented by the formula (39) (yield 84%).

(3) Third Step In the third step, a formylated triphenylamine derivative represented by the formula (39) obtained by using a Witchig method after separately synthesizing a phosphorus ylide derivative represented by the formula (40) And a phosphorus ylide derivative represented by the formula (40) were reacted to synthesize a triphenylamine derivative represented by the general formula (41).
First, the phosphorylide derivative represented by the formula (40) was synthesized along the following reaction formula (5). That is, after adding 500 g (2.47 mol) of diphenylchloromethane and 492 g (3.00 mol) of triethyl phosphite, the mixture was heated with stirring at 160 ° C. for 3 hours. Then, after cooling to room temperature, excess triethyl phosphite was distilled off under reduced pressure to obtain 639 g of a phosphorus ylide derivative represented by the formula (40) (yield 85%).

Next, the obtained phosphorylide derivative represented by the formula (40) and the formylated triphenylamine derivative represented by the formula (39) are reacted according to the following reaction formula (6) to obtain the formula (41 ) Was synthesized.
First, 36.3 g (0.12 mol) of the phosphorus ylide derivative represented by the formula (40) was accommodated while maintaining the temperature in the 500 ml two-necked flask at −20 ° C. Next, after replacing the inside of the two-necked flask with argon, 100 ml of dried THF and 75 ml (0.12 mol) of a hexane solution of n-BuLi as a catalyst were added, followed by stirring for 10 minutes. Next, 25 g (0.046 mol) of the formylated triphenylamine derivative represented by the formula (39) was added, and the reaction was carried out with stirring at −20 ° C. for 15 minutes.
Thereafter, the reaction solution was poured into 500 ml of ion-exchanged water, extracted with toluene, and the obtained organic layer was washed 5 times with ion-exchanged water. Further, anhydrous sodium 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 32 g of a triphenylamine derivative represented by the formula (41) (yield: 82.0%).

(4) Fourth Step Next, along with the following reaction formula (7), from the triphenylamine derivative represented by the formula (41), the Formylation Trimethyl represented by the formula (42) is obtained using the Filsmeier method. A phenylamine derivative was synthesized.
That is, in a 500 ml flask, 30 g (0.35 mol) of the triphenylamine derivative represented by the formula (41), 100 ml of dimethylformamide (DMF), and 16.3 g of oxychlorophosphoric acid dissolved in 100 ml of dimethylformamide. (0.11 mol) and the mixture was reacted under stirring at 85 ° C. for 30 minutes. After the reaction, the reaction solution was dropped into 400 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 with ion-exchanged water. Thereafter, anhydrous sodium sulfate and activated clay were added to the obtained organic layer, followed by drying and adsorption treatment. Thereafter, toluene was distilled off under reduced pressure, and the residue was dissolved in 200 ml of toluene and crystallized from methanol to obtain 27 g of a formylated triphenylamine derivative represented by the formula (42) (yield 86%).

Next, according to the following reaction formula (8), the formylated triphenylamine derivative represented by the formula (42) and the diphenylhydrazine represented by the formula (43) are reacted to represent the formula (5). Amine stilbene derivatives were synthesized.
That is, in a 500 ml flask, 10 g (0.011 mol) of a formylated triphenylamine derivative represented by the formula (42), 50 ml of toluene, 4.5 g (0.033 mol) of zinc chloride as a catalyst, and a formula 4.9 g (0.026 mol) of diphenylhydrazine represented by (43) was accommodated and allowed to react under stirring at room temperature for 12 hours. After the reaction, the reaction solution was dropped into a mixture consisting of 400 ml of ion exchange water and 200 ml of toluene, and the precipitated solid was separated by filtration. The obtained solid was stirred and washed with ion exchange water. Thereafter, the solid was dissolved in toluene, and the organic layer was washed with ion-exchanged water. Thereafter, anhydrous sodium sulfate and activated clay were added to the obtained organic layer, followed by drying and adsorption treatment. Thereafter, toluene was distilled off under reduced pressure, and the residue was dissolved in 200 ml of toluene and crystallized from methanol to obtain 8.1 g of an amine stilbene derivative represented by the formula (5) of yellow crystals (yield 60%). .

2. Production and Evaluation of Electrophotographic Photoreceptor A single-layer type electrophotographic photoreceptor was produced using the obtained amine stilbene derivative as a hole transport agent, and the initial sensitivity, residual potential, and half exposure amount were measured. That is, as a hole transport agent, 60 parts by weight of an amine stilbene derivative (HTM-A) represented by the formula (5) and an X-type metal-free phthalocyanine (CGM) represented by the formula (14) as a charge generator. 5 parts by weight of -A) and 100 parts by weight of a copolymer polycarbonate resin (Resin-A) represented by the formula (44) 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 photoreceptor layer. The obtained coating solution is applied onto a conductive substrate (aluminum tube) by a dip coating method, dried with hot air at 100 ° C. for 30 minutes, and a single layer type electrophotographic film having a thickness of 25 μm. A photoreceptor was obtained.
The chargeability and sensitivity characteristics of the obtained electrophotographic photosensitive member were measured. That is, using a drum sensitivity tester (manufactured by GENTEC), the potential was measured in a state of being charged to 700 V to obtain an initial charging potential (Vo). Next, the surface of the photoreceptor was irradiated with monochromatic light (half-value width: 20 nm, light amount: 1.5 μJ / cm ² ) having a wavelength of 780 nm extracted from the light of the halogen lamp using a hand pulse filter. After irradiation, the time required for the surface potential to be reduced to _1/2 was measured, and the half-exposure amount (E _1/2 ) as an index of sensitivity characteristics was measured. Further, the potential after 330 msec from the start of irradiation was measured and set as the residual potential (Vr).

[Examples 2 to 4]
In Examples 2 to 4, 20 parts by weight of each of electron transporting agents (ETM-A to C) represented by the formulas (33) to (35) were added as electron transporting agents to the coating liquid of Reference Example 1. In the same manner as in Reference Example 1 , an electrophotographic photoreceptor was prepared and evaluated.

[ Reference Example 5 and Examples 6 to 8 ]
In Reference Example 5 and Examples 6 to 8 , instead of the amine stilbene derivative (HTM-A) represented by Formula (5) used in Reference Example 1 and Examples 2 to 4 , it is represented by Formula (6). An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Reference Example 1 and Examples 2 to 4 except that the hole transport agent (HTM-B) used was used.

[ Reference Example 9 and Examples 10-12 ]
In Reference Example 9 and Examples 10 to 12 , instead of the amine stilbene derivative (HTM-A) represented by the formula (5) used in Reference Example 1 and Examples 2 to 4 , the formula (7) is used. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Reference Example 1 and Examples 2 to 4 except that the hole transport agent (HTM-C) used was used.

[Comparative Examples 1-4]
In Comparative Examples 1 to 4, instead of the amine stilbene derivative (HTM-A) represented by the formula (5) used in Reference Example 1 and Examples 2 to 4 , a positive represented by the following formula (45) was used. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Reference Example 1 and Examples 2 to 4 except that the hole transport agent (HTM-D) was used.

[Comparative Examples 5 to 8]
In Comparative Examples 5 to 8, instead of the amine stilbene derivative (HTM-A) represented by the formula (5) used in Reference Example 1 and Examples 2 to 4 , a positive represented by the following formula (46) was used. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Reference Example 1 and Examples 2 to 4 except that the hole transport agent (HTM-E) was used.

As described above in detail, the amine stilbene derivative in the present invention is excellent in sensitivity by introducing an organic group containing a substituted or unsubstituted nitrogen atom at a predetermined position in the molecule, and is compatible with the binder resin. A single-layer electrophotographic photoreceptor excellent in solubility can be obtained.
Therefore, the single-layer type electrophotographic photosensitive member of the present invention is expected to contribute to high speed and high performance of various image forming apparatuses.
Furthermore, since the amine stilbene derivative in the present invention has a high hole transport capability, it can be used in various fields such as solar cells and electroluminescence devices.

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

10: Single layer type photoconductor 12: Conductive substrate 14: Photoconductor layer 16: Barrier layer 18: Protective layer

Claims (4)

An electrophotographic photosensitive member in which a photosensitive layer is provided on a conductive substrate,
The photoreceptor layer is a single layer type containing a hole transport agent, an electron transport agent and a charge generator,
The hole transport agent is an amine stilbene derivative represented by the following general formula (1),
A single-layer electrophotographic photoreceptor, wherein the electron transport agent is a naphthoquinone derivative or a diphenoquinone derivative, or one of them.
(In General Formula (1), A is a hydrazone group represented by the following General Formula (2), and a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms. And a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted by an independent methyl group .)
(In General Formula (2), X and Y are each independently an alkyl group having 1 to 2 carbon atoms, or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group .)   2. The single-layer electrophotographic photosensitive member according to claim 1, wherein the electron transfer agent is at least one selected from the group consisting of compounds represented by the following formulas (33) to (35).


  The single-layer electrophotographic photosensitive member according to claim 1 or 2, wherein the charge generating agent is a metal-free phthalocyanine represented by the following formula (14).
The amine stilbene derivative is a method for producing an amine stilbene derivative represented by the following reaction formula (1), which is represented by the formylated triphenylamine derivative represented by the general formula (3) and the general formula (4). A hydrazine derivative obtained by reacting in the presence of a catalyst to obtain an amine stilbene derivative represented by the general formula (1 ') is obtained by a method for producing an amine stilbene derivative . 4. The single layer type electrophotographic photosensitive member according to any one of items 3 .
(In the reaction formula (1), a plurality of R ^{1 to} R ⁶ are each an independent hydrogen atom and an alkyl group having 1 to 2 carbon atoms, and a plurality of X and Y are each independently an independently having 1 to 2 carbon atoms. An alkyl group or an aryl group having 6 carbon atoms substituted or unsubstituted with a methyl group, and a plurality of Ar ¹ and Ar ² are each an aryl group having 6 carbon atoms substituted or unsubstituted with an independent methyl group; is there.)