JP3268233B2 - Amine-hydrazone compound, method for producing the same, and electrophotographic photoreceptor using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an amine-hydrazone compound, an intermediate thereof, a method for producing the same, and an electrophotographic photoreceptor containing the amine-hydrazone compound.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as zinc oxide, amorphous selenium alloy and cadmium sulfide have been used as a photoconductive material for forming a photosensitive layer of an electrophotographic photoreceptor. However, recently, these inorganic photoconductive materials have been pointed out various problems. That is, in the case of a zinc oxide-based material, the added sensitizer causes deterioration in chargeability due to corona discharge and light brown due to exposure, so that a stable image cannot be provided for a long period of time. In addition, selenium-based materials have high toxicity, and crystallization easily progresses due to external factors such as temperature and humidity, and there has been a problem that the chargeability is reduced and white spots are generated on images. In addition, cadmium sulfide-based materials have a problem that stable sensitivity cannot be obtained in a humid environment.

Therefore, in recent years, in order to solve the above problems, organic materials have been used for electrophotographic photosensitive members. In general, many organic photoconductive materials are low in production cost and high in mass productivity, low in toxicity and easily disposable. There is the advantage that the setting of the light absorption wavelength region can be easily changed, and the electrophotographic characteristics can be easily controlled by combining materials.

A photoreceptor using such an organic photoconductive material is mainly a function-separated type photoreceptor in which a charge carrier generation layer and a charge carrier transport layer are sequentially laminated on a conductive support. Have been.

[0005] Therefore, many charge carrier transporting materials having various molecular structures have been developed. A typical example is a hydrazone type (JP-A-54-5914).
No. 3), a stilbene-styryl system (JP-A-58-198)
043), triarylamines (JP-B-58-32)
No. 373), phenothiazines, triazoles, quinoxalines, oxadiazoles, oxazoles, pyrazolines, triphenylmethanes, dihydronicotinamides, indoline compounds, semicarbazone compounds and the like have been developed.

[0006]

However, even in a photoreceptor made of such an organic photoconductive material, (1) low compatibility with a binder, (2) crystals are easily precipitated,
None of them satisfy the following problems: (3) sensitivity changes when used repeatedly, (4) large residual potential, and (5) poor chargeability.

Accordingly, it is an object of the present invention to provide an electrophotographic photosensitive member having high sensitivity and high durability. In particular,
An object of the present invention is to provide an electrophotographic photoreceptor which has high charging characteristics and hardly causes a decrease in sensitivity even when used repeatedly.

[0008]

Means for Solving the Problems The present inventors have studied the above-mentioned photoconductive substance having high sensitivity and high durability, and have obtained a novel amine-hydrazone represented by the following general formula (I). The inventors have found that the compounds are effective and have completed the present invention.

Specifically, an object of the present invention is to provide an amine-hydrazone compound as a charge carrier transporting substance contained in the photoreceptor and a hydrazone compound as an intermediate thereof.

Another object of the present invention is to provide a method for producing the above-mentioned amine-hydrazone compound and a hydrazone compound which is an intermediate thereof.

That is, according to the present invention, a photosensitive layer containing a charge carrier transport material is provided on a conductive support, and the charge carrier transport material has a general formula (I):

[0012]

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[Wherein R ¹ and R ² are the same or different and each is a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, An aralkyl group which may have a substituent, R ³ is a hydrogen atom, a halogen atom,
A lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, R ⁴ and R ⁵ may be the same or different and have a lower alkyl group and a substituent Good aromatic hydrocarbon residues,
A heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of from 1 to 3]. An electrophotographic photoreceptor is provided.

Further, according to the present invention, the general formula (I):

[0015]

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[In the formula, R ¹ and R ² are the same or different and are a lower alkyl group, an aromatic hydrocarbon residue optionally having a substituent, a heterocyclic residue optionally having a substituent, An aralkyl group which may have a substituent, R ³ is a hydrogen atom, a halogen atom,
A lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, R ⁴ and R ⁵ may be the same or different and have a lower alkyl group and a substituent Good aromatic hydrocarbon residues,
A heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of 1 to 3].

Further, according to the present invention, a compound represented by the general formula (VII):

[0018]

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A hydrazone compound represented by the formula: wherein R ³ , R ⁴ , R ⁵ and n have the same meanings as in formula (I) is provided.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

Further, according to the present invention, general formula (V):

[0028]

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Wherein R ³ and n have the same meanings as in formula (I).
And a 2-formylnitrobenzo [b] furan derivative represented by the general formula (VI):

[0030]

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[Wherein R ⁴ and R ⁵ have the same meanings as in formula (I)]
Wherein the compound is reacted with a hydrazine compound represented by the following formula or a salt thereof:

[0032]

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Wherein R ³ , R ⁴ , R ⁵ and n have the same meanings as in the general formula (I).

Further, according to the present invention, the above general formula (VI)
I):

[0035]

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Wherein R ³ , R ⁴ , R ⁵ and n have the same meanings as in the general formula (I), wherein the hydrazone compound is reduced and further reacted with a halogenated compound. (I):

[0037]

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[Wherein R ¹ and R ² are the same or different and are a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, An aralkyl group which may have a substituent, R ³ is a hydrogen atom, a halogen atom,
A lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, R ⁴ and R ⁵ may be the same or different and have a lower alkyl group and a substituent Good aromatic hydrocarbon residues,
A heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of 1 to 3].

Formulas (I) and (II) contained as charge carrier transporting materials in the electrophotographic photoreceptor of the present invention and formulas (V) and (VII) of intermediates and starting materials (III) and (I)
The substituents of V) and (VI) will be described.

R ¹ , R ² , R ⁴ and R ⁵ represent a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, or a substituent. It is an aralkyl group which may be possessed. Examples of the “lower alkyl group” for R ¹ , R ² , R ⁴ and R ⁵ include a straight-chain or branched alkyl group having 1 to 4 carbon atoms.
Ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl and the like.

The "aromatic hydrocarbon residue" includes a phenyl group and a 1-naphthyl group, and the "heterocyclic residue" includes a 1-pyridyl group. Examples of the “aralkyl group” include an alkyl group having 1 to 3 carbon atoms and having a terminal phenyl group, such as benzyl and phenethyl.

Examples of the substituent in the "aromatic hydrocarbon residue", "heterocyclic residue" and "aralkyl group" include lower alkyl groups such as methyl and ethyl, lower alkoxy groups such as methoxy and ethoxy, and methyl. It includes amino groups such as amino, dimethylamino, ethylamino, ethylmethylamino, and diethylamino, and halogen atoms such as fluorine, chlorine, and bromine, and preferably has one or two of these substituents. .

R ³ is a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower dialkylamino group,
It is a trifluoromethyl group or an aralkyl group which may have a substituent.

As the “halogen atom”, a fluorine atom,
Examples include a chlorine atom and a bromine atom.

The "lower alkyl group" includes the lower alkyl group for R ¹ .

Examples of the "lower alkoxy group" include a linear or branched alkoxy group having 1 to 4 carbon atoms, and specific examples include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert
-Butoxy and the like.

Examples of the "lower dialkylamino group" include an amino group substituted by a linear or branched alkyl group having 1 to 4 carbon atoms. Specifically, dimethylamino, diethylamino, diisopropylamino ,
Dibutylamino and the like.

The "aralkyl group" includes the lower aralkyl group represented by R ¹ .

"X" includes a halogen atom such as a chlorine atom and a bromine atom.

[0050]

DETAILED DESCRIPTION OF THE INVENTION 2-Formylnitrobenzo [b] furan derivatives, hydrazone compounds and amines of the present invention
The hydrazone compound can be easily synthesized by the following synthetic route.

That is, the formula (III):

[0052]

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[Wherein R ³ and n have the same meanings as in formula (I)]
Nitrosalicylic aldehyde derivative (1 equivalent)
And the general formula (IV):

[0054]

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In the formula, X represents a halogen atom] and the epihalohydrin compound (1 to 20 equivalents) in a solvent or in the absence of a solvent together with a base (0.01 to 2 equivalents) at 80 to 130 ° C. Stir for 8 to 8 hours.
II):

[0056]

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[Wherein R ³ and n have the same meanings as in formula (I)]
Is synthesized.

Examples of the solvent used here include diethyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether and the like.

As the base, triethylamine,
Diisopropylethylamine, pyridine, 1,8-diazabicyclo [5,4,0] undec-7-ene, 1,5
Organic amine bases such as -diazabicyclo [4,3,0] none-5-ene, or potassium carbonate, sodium carbonate, calcium carbonate, sodium acetate, potassium acetate, calcium acetate, potassium oxalate E, sodium oxalate And the like.

Next, this tricyclic compound (1 equivalent) is stirred with a perchlorate (1-2 equivalent) at 60 to 90 ° C. for 2 to 4 hours in a mixed solvent of an organic solvent and water under strongly acidic conditions. I do. Here, examples of the organic solvent to be mixed with water include acetonitrile, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, and the like, and the mixing ratio with water is 1: 4 to 4: 1. Concentrated hydrochloric acid or the like can be used as a strong acid.

Thereafter, the mixture is diluted with an organic solvent such as dichloromethane or chloroform, and a base (1 to 5 equivalents) is added thereto.
By heating and stirring at で 50 degrees for 3 to 6 hours, the general formula (V):

[0062]

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[Wherein R ³ and n have the same meanings as in formula (I)]
To synthesize a 2-formylnitrobenzo [b] furan derivative represented by As the base, those mentioned above can be used.

Next, a 2-formylnitrobenzo [b] furan derivative (1 equivalent) represented by the general formula (V) and the general formula (IV):

[0065]

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[Wherein R ⁴ and R ⁵ have the same meanings as in formula (I)]
A hydrazine compound (2.0 to 2.4 equivalents) represented by the following formula (VII):

[0067]

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Wherein R ³ , R ⁴ , R ⁵ and n have the same meanings as in the general formula (I). As the organic solvent, ethanol, methanol, acetonitrile, tetrahydrofuran, 1,4-dioxane and the like can be used. Also, as the catalyst, acetic acid,
Potassium acetate, calcium acetate, sodium acetate and the like are used.

Next, tetrahydrofuran / water, 1,4-tetrahydrofuran is added to the hydrazone compound represented by the general formula (VII).
By adding 100 to 200 mesh iron powder in a mixed solvent such as dioxane / water at a molar ratio of 1:20 to 40, performing a reduction reaction by stirring while heating, and further reacting with a halogenated compound as usual. , The general formula (I):

[0070]

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The amine-hydrazone compound represented by the formula can be easily synthesized.

Examples of the halogenated compound used here include benzene iodide, 3-methyliodide benzene, 4-methyliodide benzene, benzyl chloride and the like.

The amine-hydrazone compound of the present invention can be synthesized in a high yield by the above reaction route.

In the present invention, for example, the exemplified compounds shown in Table 1 below can be synthesized by the above synthesis method and used as a charge carrier transporting material for an electrophotographic photosensitive member. However, this does not limit the amine-hydrazone compound of the present invention at all.

[0075]

[Table 1]

In the general formula (I), the formula (II):

[0077]

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[Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and n have the same meanings as in the general formula (I)], a compound having high sensitivity and high durability as a charge carrier transporting substance. Provide a photoreceptor.

In the present invention, the amine-hydrazone compound is used as a charge carrier transporting substance for an electrophotographic photosensitive member. The electrophotographic photoreceptor according to the present invention is obtained by containing one or more of the above-described amine-hydrazone compounds. Further, another charge carrier transporting material can be contained.

The electrophotographic photosensitive member is formed by laminating a photosensitive layer on a conductive support. Various types of photosensitive layers are known, and the photosensitive layer of the electrophotographic photosensitive member of the present invention may be any of them.

The conductive support on which the photosensitive layer is formed is formed by forming a photosensitive layer thereon and applying an electric field to the photosensitive layer to transport charge carriers (electrons or holes) generated by light absorption of the photosensitive layer. And a conductor having a shape such as a drum, a plate, or a sheet can be used.
Materials used for the conductor include metals such as copper and aluminum, and paper or plastic films that have been subjected to conductive processing such as paper in which carbon or a carbon material is dispersed or polyester films in which aluminum is deposited. .

The photosensitive layer is for forming a latent image (electrostatic latent image) having a two-dimensional distribution of electrostatic charges, and comprises a charge carrier generating substance and a charge carrier transporting substance.
Further, it can be formed by appropriately containing a binder, a sensitizer, a plasticizer, an electric property deterioration preventing agent, an antioxidant, and a leveling agent.

As the charge carrier generating substance, known pigments such as azo compounds and phthalocyanine compounds can be used.

The electrophotographic photosensitive member of the present invention can be manufactured by a conventional method.

The embodiments of the electrophotographic photosensitive member of the present invention are schematically shown in FIGS.

(1) FIG. 1 shows a charge carrier generation layer 5 in which a charge carrier generation material 2 is dispersed as a main component in a binder as a photosensitive layer 4 on a conductive support 1 and a charge carrier transport material 3. A function-separated type electrophotographic photoreceptor having a charge carrier transport layer 6 dispersed in a binder as a main component, wherein the amine-hydrazone compound of the present invention is used as the charge carrier transport material 3 in the charge carrier transport layer 6. 2 shows the configuration of the photoconductor.

(2) FIG. 2 shows a function-separated type electrophotographic photoreceptor comprising the same stack of the charge carrier generation layer 5 and the charge carrier transport layer 6 as in FIG. 1. However, in contrast to FIG. The charge carrier generation layer 5 is formed on the transport layer 6, and shows the structure of a photoreceptor using the amine-hydrazone compound of the present invention as the charge carrier transport material 3 in the charge carrier transport layer 6. .

(3) FIG. 3 shows an electrophotographic photosensitive member comprising a single layer in which a charge carrier generating substance 2 and a charge carrier transporting substance 3 are dispersed in a binder as a photosensitive layer 4 ′ on a conductive support 1. It is shown.

(4) FIG. 4 shows an electrophotographic photosensitive member in which a surface protective layer 7 is further laminated on the surface of the photosensitive member of FIG.

(5) FIG. 5 shows an electrophotographic photosensitive member in which an intermediate layer 8 is provided between the conductive support 1 and the same photosensitive layer 4 as in FIG.

(6) FIG. 6 shows an electrophotographic photosensitive member in which an intermediate layer 8 is provided between the conductive support 1 and the same photosensitive layer 4 'as in FIG.

The surface protective layer 7 provided on the surface of the photosensitive layer 4 is intended to improve durability against mechanical stress and to receive and hold the charge of corona discharge in a dark place. is there. Therefore, it is composed of chemically stable substances,
The charge carrier generation layer has the ability to transmit light that is exposed to light, and it is necessary to neutralize and eliminate surface charges by receiving the injection of generated and transmitted light upon exposure to the charge carrier generation layer. The charge carrier generating material is required to be as transparent as possible in the wavelength region where the light absorption is maximum.

The intermediate layer 8 provided between the conductive support 1 and the photosensitive layer 4 provides a protective function and an adhesive function, improves coating properties, and further improves charge injection of the photosensitive layer from the support. It is what it was.

Next, the present invention will be described in detail with reference to examples, but these examples do not limit the scope of the present invention.

(Synthesis Example 1) Synthesis of 2-formyl-5-nitrobenzo [b] furan 17.5 g (1.0 equivalent) of 5-nitrosalicylaldehyde was added to about 41.2 ml of epichlorohydrin (5.0 equivalent). ) And add 16.1 ml of triethylamine
(1.1 equivalent) was added and the mixture was heated and stirred at 60 to 85 ° C. for about 2.5 hours. After confirming the completion of the reaction by thin layer chromatography (TLC), the mixture was allowed to cool, excess epichlorohydrin was removed by a rotary evaporator, and ethanol was added to produce a white powder. This white powder was filtered off, washed thoroughly with ethanol, and then recrystallized with ethanol.
16.8 g (yield 72%) of the target tricyclic compound was obtained.

The tricyclic compound thus obtained
6 g (1.0 equivalent) of acetonitrile 50 ml / water 50
dissolved in a mixed solvent of 4.9 ml of sodium periodate.
2 g (1.5 equivalents) was added, and about 3 ml of concentrated hydrochloric acid was further added.
The mixture was heated and stirred at about 80 degrees for 1.5 hours. After completion of the cleavage reaction was confirmed by TLC, the mixture was allowed to cool. This reaction solution was diluted with 200 ml of dichloromethane, and 20 ml of triethylamine was added, followed by heating and stirring at 30 to 40 degrees for 5 hours. After confirming the completion of the intramolecular aldol condensation reaction by TLC, the mixture was allowed to cool and extracted in a usual manner. The crude product thus obtained was purified by silica gel column chromatography (silica gel: Fujiserial Chemical; BW-200, elution solvent: hexane / dichloromethane = 9/1 to 100% dichloromethane) to obtain the desired 2-formyl -5-nitrobenzo [b]
3.43 g (67% yield) of furan was obtained.

To confirm the structure of 2-formyl-5-nitrobenzo [b] furan, ¹ H-NMR and ¹³ C-NM
R was measured.

[0098] ¹ H-NMR spectrum in FIG. 7, ¹³ C-
FIG. 8 shows the NMR spectrum.

¹³ C-NMR 113.8 (CH), 117.3 (CH), 120.8
(CH), 124.7 (CH), 127.3 (C), 1
45.4 (C), 155.3 (C), 158.9
(C), 179.8 (CH) These signals support the structure of 2-formyl-5-nitrobenzo [b] furan.

(Synthesis Example 2) N, N-diphenyl-2-
Synthesis of (5-nitrobenzo [b] furyl) hydrazone 2
1.46 g of formyl-5-nitrobenzo [b] furan
(1.0 equivalent) was dissolved in 50 ml of ethanol, and N, N
2.02 g (1.2 equivalents) of diphenylhydrazine hydrochloride and a catalytic amount of potassium acetate were added, and the mixture was heated and stirred at 80 ° C. for 2 hours. After completion of the reaction was confirmed by TLC, the mixture was allowed to cool, and the precipitated solid was separated by filtration and sufficiently washed with ethanol.
2.00 g (yield 73%) of N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone was obtained.

To confirm the structure of N, N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone, ¹ H
-NMR and ¹³ C-NMR were measured.

[0102] ¹ H-NMR spectrum in FIG. 9, ¹³ C-
The NMR spectrum is shown in FIG.

¹³ C-NMR 104.5 (CH), 111.4 (CH), 117.1
(CH), 120.3 (CH), 122.6 (CH),
123.7 (CH), 125.5 (CH), 129.2
(C), 130.0 (CH), 142.6 (C), 14
4.3 (C), 156.8 (C), 157.7 (C) These signals support the structure of N, N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone.

(Synthesis Example 3) Synthesis of Exemplified Compound No. 16 N, N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone (3.0 g, 1.0 equivalent) was dissolved in 1,4-dioxane (20 ml). 4.7 g of 100 mesh iron powder previously activated with 2.0 ml of concentrated hydrochloric acid
1,4-dioxane / water to which (10 equivalents) was added = 1: 1
In 80 ml of the mixed solvent of
Reflux at about 100 degrees for 3 hours. After confirming the completion of the reaction by TLC, the supernatant was immediately filtered through celite while hot. The residue was thoroughly washed with about 50 ml of hot 1,4-dioxane and filtered. Repeat this operation from 3 to 4
The back solution which was repeated several times was combined, and concentrated by a rotary evaporator. After concentration, the residue was recrystallized from 1,4-dioxane to obtain 2.2 g (80% yield) of 2- (5-aminobenzo [b] furyl) -N, N-diphenylhydrazone.

To 2.2 g (1.0 equivalent) of 2- (5-aminobenzo [b] furyl) -N, N-diphenylhydrazone thus obtained, 2.4 ml of benzyl chloride was added.
(3.0 equivalents) and 2N aqueous sodium hydroxide solution 1
6.8 ml was added, and the mixture was heated and stirred at 100 degrees for 8 hours. T
After confirming the completion of the reaction by LC, the reaction solution was allowed to cool, neutralized, and extracted from the aqueous layer with 30 ml of ethyl acetate three times. The extracts were combined, washed with 30 ml of aqueous sodium hydrogen carbonate solution and 30 ml of saturated aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated by a rotary evaporator. The residue was purified by silica gel column chromatography (eluent: hexane: dichloromethane = 7: 3 to 1: 1), and 2.5 g of the desired Exemplified Compound No. 16 was obtained (yield: 7).
4%).

To confirm the structure of this compound, ¹ H-NM
R and ¹³ C-NMR were measured. FIG. 11 shows the ¹ H-NMR spectrum and FIG. 12 shows the ¹³ C-NMR spectrum.

¹³ C-NMR 55.2 (CH2), 103.7 (CH), 105.2
(CH), 113.3 (CH), 112.4 (CH),
122.5 (CH), 124.9 (CH), 125.8
(CH), 126.79 (CH), 126.82 (C
H), 128.5 (CH), 129.4 (C), 12
9.8 (C), 138.8 (C), 143.0 (C),
146.0 (C), 148.8 (C), 153.6
(C) These signals well support the structure of Exemplified Compound No16.

(Synthesis Examples 4 to 33) Exemplified Compounds Nos. 1 to 30 Compounds represented by Exemplified Compounds Nos. 1 to 30 (except No. 16) were synthesized and purified in the same manner as in Synthesis Examples 1 to 3.

Example 1 An aluminum-evaporated polyester film (thickness: 80 μm) was used as a support, and 0.4 g of an x-type non-metallic phthalocyanine (Fastgen Blue, manufactured by Dainippon Ink Co., Ltd.) was placed thereon. 0.3 g of a copolymer resin (manufactured by Sekisui Chemical; Eslex M) is added to 30 ml of an ethyl acetate solution in which the resin is dispersed, and dispersed in a paint conditioner (manufactured by Red Level Co., Ltd.) for about 20 minutes, and applied by a doctor blade method. And dried. The film thickness after drying is 0.
It was 4 μm.

On the pigment layer (charge carrier generation layer), 1 g of the amine-hydrazone compound of Exemplified Compound No. 16 of the present invention and a polyarylate resin (U-10
0) A solution prepared by dissolving 1.2 g in dichloromethane was applied by a squeezing doctor to prepare a resin- (amine-hydrazone compound) solid solution phase (charge carrier transport layer).

The laminated electrophotographic photoreceptor thus produced was subjected to an electrostatic recording paper tester (made by Kawaguchi Electric; EPA-8,
200), the electrophotographic properties were evaluated. The measurement conditions are
10 μA constant current method, static method: No. 3 and -500 V by white light irradiation (irradiation light: 5 lux)
Exposure E required to attenuate to -250V
_1/2 (lux · sec) and the initial potential V ₀ (- V) were measured, and after 500 times the same operation and subsequently measured electrophotographic properties in the same manner as described above.

(Examples 2 to 10) A total of 10 kinds of electrophotographic photoreceptors of the present invention were prepared in the same manner as in Example 1 except that another exemplified compound of the present invention was used as a charge carrier transporting substance. A similar property test was performed for each.

Table 2 shows the above results.

[0114]

[Table 2]

From the table, it was found that the amine-hydrazone compound of the present invention had good sensitivity and repetition characteristics.

[0116]

The amine-hydrazone compound of the formula (I) used as the charge carrier transporting material in the electrophotographic photoreceptor of the present invention has high efficiency even when repeatedly used against external factors such as temperature and humidity. Transports charge carriers,
An electrophotographic photoreceptor having excellent stability, high charging characteristics, and hardly causing a decrease in sensitivity due to repetition is provided.

Among them, the amine-hydrazone compound of the formula (II) has particularly excellent properties as a charge carrier transporting substance, so that it is excellent in stability, has high charging properties, and hardly causes a decrease in sensitivity due to repetition. A photoreceptor is provided.

The amine-hydrazone compound of the present invention can be used in the photosensitive layer in any form of mixing and separation with a charge carrier generating substance in the photosensitive layer. A carrier transport material is provided.

Further, the 2-formylnitrobenzo [b] furan derivative and the hydrazone compound of the present invention, and the production method of the amine-hydrazone compound of the present invention via these derivatives to obtain the desired compound in high yield. And the post-treatment after the reaction is simple, so that an easy and high-yield production method is provided. In particular, 2-
In the method for producing the formylnitrobenzo [b] furan derivative, the position of the amino group is determined by selecting the starting material, so that the desired compound can be obtained easily and in a high yield as compared with the conventional method. .

Accordingly, there is provided an electrophotographic photoreceptor having excellent stability to temperature and humidity, high charge characteristics, and high sensitivity and high durability with little decrease in sensitivity even when used repeatedly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a layer structure of an electrophotographic photosensitive member using an amine-hydrazone compound of the present invention.

FIG. 2 is a cross-sectional view schematically showing a layer structure of an electrophotographic photosensitive member using the amine-hydrazone compound of the present invention.

FIG. 3 is a cross-sectional view schematically showing a layer structure of an electrophotographic photosensitive member using the amine-hydrazone compound of the present invention.

FIG. 4 is a cross-sectional view schematically showing a layer structure of an electrophotographic photosensitive member using the amine-hydrazone compound of the present invention.

FIG. 5 is a cross-sectional view schematically showing a layer configuration of an electrophotographic photoreceptor using the amine-hydrazone compound of the present invention.

FIG. 6 is a cross-sectional view schematically showing a layer structure of an electrophotographic photosensitive member using the amine-hydrazone compound of the present invention.

FIG. 7 is a ¹ H-NMR spectrum of 2-formyl-5-nitrobenzo [b] furan of the present invention.

FIG. 8 is a ¹³ C-NMR spectrum of 2-formyl-5-nitrobenzo [b] furan of the present invention.

FIG. 9 is a ¹ H-NMR spectrum of N, N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone of the present invention.

FIG. 10 is a ¹³ C-NMR spectrum of N, N-diphenyl-2- (5-nitrobenzo [b] furyl) hydrazone of the present invention.

FIG. 11 shows ¹ H-NMR of Exemplified Compound No. 16 of the present invention.
It is a spectrum.

FIG. 12 is a ¹³ C-NMR of Exemplified Compound No. 16 of the present invention.
It is a spectrum.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 charge carrier generating material 3 charge carrier transporting material 4 photosensitive layer 4 ′ photosensitive layer 5 charge carrier generating layer 6 charge carrier transporting layer 7 surface protective layer 8 intermediate layer

Claims (6)

(57) [Claims] 1. A charge carrier transporting material having the general formula (I): [Wherein R 1 and R 2 are the same or different and each have a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, An aralkyl group which may have a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, and R4 and R5 may be the same or different. And a lower alkyl group,
An aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of 1 to 3] An electrophotographic photoreceptor comprising at least one amine-hydrazone compound. 2. The compound represented by the general formula (I) is represented by the following general formula (II): [Wherein, R1, R2, R3, R4, R5, and n represent the general formula (I)
The electrophotographic photoreceptor according to claim 1, which is an amine-hydrazone compound represented by the following formula: 3. A compound of the general formula (I): [Wherein R 1 and R 2 are the same or different and each have a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, An aralkyl group which may have a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, and R4 and R5 may be the same or different. And a lower alkyl group,
An aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of 1 to 3.] Amine represented
Hydrazone compounds. 4. A compound of the general formula (V): Wherein R 3 and n have the same meanings as in formula (I).
-Formylnitrobenzo [b] furan derivative and general formula (VI): Wherein R 4 and R 5 have the same meanings as in the general formula (I), and reacted with a hydrazine compound or a salt thereof represented by the general formula (VII): [Wherein R 3, R 4, R 5 and n have the same meaning as in the general formula (I)], a method for producing an intermediate comprising a hydrazone compound represented by the following formula: 5. A compound of the general formula (VII): [Wherein R 3, R 4, R 5 and n have the same meanings as in the general formula (I)]. 6. A compound of the general formula (VII): Wherein R 3, R 4, R 5, and n have the same meanings as in the general formula (I), wherein the hydrazone compound represented by the general formula (I) is reduced and further reacted with a halogenated compound. 1) [Wherein R 1 and R 2 are the same or different and each have a lower alkyl group, an aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, An aralkyl group which may have a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower dialkylamino group, a trifluoromethyl group or an aralkyl group which may have a substituent, and R4 and R5 may be the same or different. And a lower alkyl group,
An aromatic hydrocarbon residue which may have a substituent, a heterocyclic residue which may have a substituent, an aralkyl group which may have a substituent, and n represents an integer of 1 to 3.] Amine represented
A method for producing a hydrazone compound.