JP3418095B2 - Electrophotographic photoreceptor, cyclic bishydrazone compound, and method for producing cyclic bishydrazone compound - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in an electrophotographic process, a cyclic bishydrazone compound preferably used in the electrophotographic photosensitive member, and a method for producing a cyclic bishydrazone compound.

[0002]

2. Description of the Related Art Generally, there are various methods in the electrophotographic process. As typical examples thereof, a direct method, a latent image transfer method and the like have been conventionally known. In the electrophotographic photosensitive member used in such an electrophotographic process,
Materials for the photosensitive layer having a photoconductive function include (1) high chargeability due to corona discharge in a dark place,
(2) In the dark place, there is little attenuation of the charge obtained by corona discharge, (3) the charge is rapidly dissipated by light irradiation, (4) there is little residual charge after light irradiation, (5) Basic characteristics such as little increase in residual potential and decrease in initial potential during repeated use, and (6) little change in electrophotographic characteristics due to temperature and humidity are required.

As materials having such properties, there have been conventionally used inorganic oxides such as zinc oxide (Japanese Patent Publication No. 57-19780), cadmium sulfide (Japanese Patent Publication No. 58-46018), and amorphous selenium alloys. Conductive materials have been used, but in recent years, the following problems have been pointed out. That is, in a zinc oxide-based material, a sensitizer causes deterioration of charge due to corona discharge and photobleaching due to exposure, so that a stable image cannot be obtained for a long period of time. Further, with the cadmium sulfide-based material, a stable image cannot be obtained under high humidity conditions. Furthermore, selenium-based materials have problems such as thermal instability, characteristic deterioration due to crystallization, and manufacturing difficulty.

Therefore, from a future perspective, organic materials that do not have such problems are more prone than inorganic materials that have production problems due to resource depletion, pollution concerns due to toxicity, and environmental problems. Electrophotographic photoreceptors made of materials have been actively researched, and as a result, electrophotographic photoreceptors using various organic compounds have been studied. In particular, in the recent years of research and development, the concept of a function-separated photosensitive layer has been actively introduced, and among them,
A method in which a charge generation layer and a hole transfer charge transfer layer are sequentially laminated on a conductive support to negatively charge the charge transfer surface is the mainstream method.

By separating the functions in this way,
It has become possible to independently develop a material having a charge generation function and a material having a charge transfer function, and as a result, many charge generation materials and charge transfer materials having various molecular structures have been developed. Of these, representative ones of the charge transfer substances are classified from the viewpoint of their structural characteristics, that is, hydrazone compounds (JP-A-54-59143) and stilbene-styryl compounds (JP-A-58-198043). ), Triarylamine compounds (Japanese Patent Publication No. 58-3
2372), phenothiazine compounds, triazole compounds, quinoxaline compounds, oxadiazole compounds, oxazole compounds, pyrarizone compounds, triphenylmethane compounds, dihydronicotinamide compounds, indoline compounds, semicarbazone compounds, etc. Has been done.

[0006]

However, in spite of the fact that a large number of organic compounds have been developed as charge transfer substances as described above, (a) the compatibility with the binder is low, and (b) crystals are Problems such as easy precipitation, (c) changes in sensitivity to light when the electrophotographic photoreceptor is repeatedly used, (d) poor chargeability and repetitive characteristics, (e) poor residual potential characteristics, etc. An organic compound capable of solving all the problems has not been developed, and the basic properties required for the electrophotographic photosensitive member as shown in the above (1) to (6) and mechanical properties. It is the current situation that a material sufficiently satisfying the desired strength and high durability has not been obtained yet.

The present invention has been made to solve the above-mentioned problems of the prior art, and has a high charging property and a high sensitivity and a high durability such that the photosensitivity hardly deteriorates even when it is repeatedly used. An object is to provide an electrophotographic photoreceptor, a novel cyclic bishydrazone compound suitable for use in the electrophotographic photoreceptor, and a method for producing the cyclic bishydrazone compound.

[0008]

Means for Solving the Problems As a result of research on a photoconductive material having high sensitivity and high durability, the present inventors have found that a bishydrazone compound represented by the following general formula (I) is contained in a photosensitive layer. It has been found that it is effective to include in.

That is, in the electrophotographic photosensitive member of the present invention, the photosensitive layer provided on the conductive support contains the cyclic bishydrazone compound represented by the following general formula (I). The above object is achieved.

[0010]

[Chemical 1]

(In the formula, Z represents an atomic group having a divalent group necessary for forming a heterocyclic ring which may have a substituent or a condensed heterocyclic ring which may have a substituent, and a represents An alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms,
A dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom is shown, and n is 1, 2 or 3. However, when n is 2 or more, each of the plurality of a's may be the same or different, and may form a ring with each other. ) The cyclic bishydrazone compound represented by the general formula (I) may be a compound represented by the following general formula (II).

[0012]

[Chemical 2]

(In the formula, Z, a and n have the same meanings as described above.) The cyclic bishydrazone compound represented by the general formula (I) is a compound represented by the following general formula (III): Good.

[0014]

[Chemical 3]

(In the formula, b represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and m is 1, 2, 3, 4, 5, 6, 7, or 8 are shown.
However, when m is 2 or more, each of the plurality of b may be the same or different, and may form a ring with each other. a and n have the same meanings as described above. ) The cyclic bishydrazone compound represented by the general formula (I) may be a compound represented by the following general formula (IV).

[0016]

[Chemical 4]

(In the formula, a, b and n have the same meanings as described above.) The photosensitive layer includes a charge generating layer containing a charge generating substance and a charge transferring layer containing a charge transferring substance. And the charge transfer substance may be the cyclic bishydrazone compound.

The photosensitive layer may be a single layer containing a charge generating substance and a charge transfer substance, and the charge transfer substance may be the cyclic bishydrazone compound.

The cyclic bishydrazone compound of the present invention is a cyclic bishydrazone compound represented by the following general formula (I), and thereby the above object is achieved.

[0020]

[Chemical 1]

(In the formula, Z, a and n have the same meanings as described above.) In the method for producing the cyclic bishydrazone compound of the present invention, the cyclic bishydrazone compound represented by the following general formula (I) is produced. A method represented by the following general formula (V):
The formylbenzo [b] furan compound derivative is reacted with a cyclic hydrazine reagent represented by the following general formula (VI), and thereby the above object is achieved.

[0022]

[Chemical 1]

(In the formula, Z, a and n have the same meanings as described above.)

[0024]

[Chemical 5]

(In the formula , a and n have the same meanings as described above.)

[0026]

[Chemical 6]

(In the formula, Z, a and n have the same meanings as described above.) The operation of the present invention will be described below.

Since the cyclic bishydrazone compound of the present invention is a novel compound and has a wide conjugated system as shown in the above general formula (I), it has a high charge mobility to enhance the electrophotographic photoreceptor. The residual potential characteristics can be improved. Further, since the cyclic bishydrazone compound of the present invention has excellent compatibility with the binder, it can be incorporated in a large amount in the photosensitive layer to improve the photosensitivity of the electrophotographic photoreceptor. Furthermore, since the cyclic bishydrazone compound of the present invention is less likely to precipitate as crystals, it is possible to stabilize the characteristics of the electrophotographic photoreceptor during repeated use.

According to the method for producing a cyclic bishydrazone compound of the present invention, the cyclic bishydrazone compound of the present invention can be produced very easily in a high yield.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The cyclic bishydrazone compound of the present invention is represented by the following general formula (I).

[0032]

[Chemical 1]

In the above general formula (I), Z is an atomic group having a divalent group necessary for forming a heterocyclic ring which may have a substituent or a condensed heterocyclic ring which may have a substituent. Indicates. Specific examples of Z include a 2,3-dihydroindolyl group, a 1,2,3,4-tetrahydroquinolyl group, a carbazolyl group, and a 1,2,3,4-tetrahydrocarbazolyl group. To be Generally, it is preferably 2,3-dihydroindolyl group or 1,2,3,4-tetrahydrocarbazolyl group.

In the general formula (I), a is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms,
A dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom is shown. Specific examples of a include alkyl groups such as methyl group, ethyl group, n-propyl group and iso-propyl group, alkoxy groups such as methoxy group, ethoxy group and propoxy group, dimethylamino group, diethylamino group, diamino group, -Iso-propylamino group and di-
Examples thereof include a dialkylamino group such as n-butyl group, a halogen atom such as fluorine and chlorine, a hydrogen atom and the like, and generally, an electron donating substituent is preferable.

Further, in the above general formula (I), n is 1, 2
Or 3 is shown. However, when n is 2 or more, the above-mentioned a
May be the same or different, and may form a ring with each other.

Specific examples of the cyclic bishydrazone compound represented by the above general formula (I) include, but are not limited to, those shown in Tables 1 to 4 below.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

Of the cyclic bishydrazone compounds represented by the above general formula (I), those represented by the following general formula (II) are easy to procure synthetic raw materials at the present time and are suitable for mass production. .

[0042]

[Chemical 2]

In the general formula (II), Z, a and n have the same meanings as described above.

Further, among the cyclic bishydrazone compounds represented by the above general formula (I), those represented by the following general formula (III) and the following general formula (IV) synthesize the cyclic bishydrazone compound of the present invention. There are many variations of hydrazine reagents required above that can be procured.

[0045]

[Chemical 3]

(In the formula, b represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a dialkylamino group having 1 to 3 carbon atoms, a halogen atom or a hydrogen atom, and m is 1, 2, 3, 4, 5, 6, 7, or 8 are shown.
However, when m is 2 or more, each of the plurality of b may be the same or different, and may form a ring with each other. a and n have the same meanings as described above. )

[0047]

[Chemical 4]

(Where m is 1, 2, 3, 4, 5, 6,
Indicates 7, 8, 9 or 10. a, b and n have the same meanings as described above. ) In the above general formula (III), b is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and 1 to 3 carbon atoms.
Represents a dialkylamino group, a halogen atom or a hydrogen atom. A specific example of b is the same as that of a.

In the above general formula (III), m is 1,
1, 2, or 3 indicating 2, 3, 4, 5, 6, 7 or 8
Indicates. However, when m is 2 or more, each of the above-mentioned b may be the same or different, and may form a ring with each other.

Further, in the general formula (III), a and n have the same meanings as described above.

In the above general formula (IV), m is 1, 2, 3,
4, 5, 6, 7, 8, 9 or 10 is shown.

Further, in the general formula (IV), a, b and n have the same meanings as described above.

The cyclic bishydrazone compound of the present invention can be easily produced, for example, as follows.

A 2-formylbenzo [b] furan compound derivative represented by the following general formula (V) and the following general formula (V
By reacting with the hydrazine reagent represented by I), the cyclic bishydrazone compound represented by the above general formula (I) of the present invention can be obtained.

[0055]

[Chemical 5]

[0056]

[Chemical 6]

In the above general formulas (V) and (VI), Z, a and n have the same meanings as described above.

This reaction is carried out, for example, with ethanol, methanol, acetonitrile, tetrahydrofuran or 1,
1. In an organic solvent such as 4-dioxane, 1.0 equivalent of the 2-formylbenzo [b] furan compound derivative represented by the general formula (V) and 2. the hydrazine reagent represented by the general formula (VI). 00 equivalent to 2.40 equivalent,
It is carried out by heating and stirring at a temperature of 40 ° C. to 80 ° C. for 3 hours to 10 hours using 0.0001 equivalent to 0.001 equivalent of acetic acid, potassium acetate, calcium acetate, sodium acetate or the like as a catalyst.

The electrophotographic photosensitive member of the present invention comprises one kind of the cyclic bishydrazone compound of the present invention represented by the general formula (I) in the photosensitive layer having a photoconductive function provided on the conductive support. Alternatively, it contains two or more kinds, has a high charging property, and has an excellent performance that the deterioration of photosensitivity during repeated use hardly occurs.

There are various possible embodiments of the above-mentioned photosensitive layer. A laminated structure of a charge generation layer containing a charge generation substance to improve charge generation efficiency and a charge transfer layer containing a charge transfer substance. , And a single layer containing a charge generating substance and a charge transfer substance can be applied. For example, the constitutions of the electrophotographic photosensitive members as shown in FIGS. 1 to 5 below can be considered.

The electrophotographic photosensitive member of FIG. 1 is a function-separated type, and the photosensitive layer 4 provided on the conductive support 1 has a laminated structure of a charge generation layer 5 and a charge transfer layer 6. In the charge generation layer 5, a sensitizing dye as the charge generation substance 2 or a pigment represented by an azo pigment and a phthalocyanine pigment is dissolved or dispersed in a polymerizable film forming binder as a main component. The charge transfer layer 6
In the above, the cyclic bishydrazone compound of the present invention as the charge transfer substance 3 and an antioxidant or an electron-withdrawing compound added as necessary are dissolved or dispersed in the binder.

The electrophotographic photosensitive member of FIG. 2 is similar to that of FIG.
The photosensitive layer 4 provided on the conductive support 1 is a function-separated type having a laminated structure of a charge generation layer 5 and a charge transfer layer 6, but the charge transfer layer 6 and the charge generation layer 5 are stacked. The order is the reverse of FIG.

The electrophotographic photosensitive member of FIG. 3 is a single layer type, and the photosensitive layer 40 provided on the conductive support 1 has both a function as a charge generating layer and a function as a charge transfer layer. ing. The photosensitive layer 40 contains the cyclic bishydrazone compound of the present invention as the charge transfer substance 3, a sensitizing agent as the charge generating substance 2, and a chemical sensitizer or an electron-withdrawing compound which is added as necessary. It is dissolved or dispersed in the binder.

The electrophotographic photosensitive member of FIG. 4 has the same structure as that of FIG.
The photosensitive layer 4 provided on the conductive support 1 is of a function separation type having a laminated structure of a charge generation layer 5 and a charge transfer layer 6, and the photosensitive support 4 is provided between the conductive support 1 and the photosensitive layer 4. Is provided with an intermediate layer 7. The intermediate layer 7 is intended to impart a protective function and an adhesive function to enhance the coatability and further improve the injection of charges from the conductive support 1 to the photosensitive layer 4.

As in FIG. 3, the photosensitive layer 40 provided on the conductive support 1 is a single layer type containing the charge generating substance 2 and the charge transfer substance 3 as in FIG. Sexual support 1
The intermediate layer 7 is provided between the photosensitive layer 40 and the photosensitive layer 40. The intermediate layer 7 is intended to impart a protective function and an adhesive function to enhance the coatability and further improve the injection of charges from the conductive support 1 into the photosensitive layer 40.

The photosensitive layers 4 and 40 may contain a charge transfer substance 3 other than the cyclic bishydrazone compound of the present invention, for example, 4- (dibenzylamino) benzaldehyde-N, N-diphenylhydrazone. , 4- (ethylphenylamino) benzaldehyde-N, N-diphenylhydrazone, 4-di (p-tolylamino) benzaldehyde-N, N-diphenylhydrazone, 3,3-
Bis- (4'-diethylaminophenyl) -acrolein-N, N-diphenylhydrazone, triphenylamine compound (for example, 4-methoxy-4 '-(4-methoxystyryl) triphenylamine, 4-methoxy-4'-
Styryltriphenylamine) and the like.

As the polymerizable film-forming binder constituting the photosensitive layers 4 and 40, various binders can be used depending on the field of application of the electrophotographic photoreceptor. For example, in the field of electrophotographic photoreceptors for copying machines or printers, it is preferable to use polystyrene resin, polyvinyl acetal resin, polysulfone resin, polycarbonate resin, polyphenylene oxide resin, polyester resin, alkyd resin, polyarylate resin and the like. These may be used alone or in combination of two or more. In particular, polystyrene resin, polycarbonate resin,
Polyphenylene oxide resin, polyarylate resin, and the like are preferable because they have a volume resistance value of 10 ¹³ Ω or more and are excellent in film forming property and potential property.

These binders are preferably added in a weight ratio of 0.2 to 20 times, more preferably 0.5 to 5 times the weight of the cyclic bishydrazone compound of the present invention.
Double the rate. When the ratio of the binder is 0.5 times or less, the cyclic bishydrazone compound may be precipitated from the surface of the photosensitive layer, and when the ratio of the binder is 5 times or more, a significant decrease in sensitivity may occur. Become. Further, when used in a printing plate, an alkaline binder is necessary. Here, the alkaline binder is an acidic group soluble in water or an alcoholic alkaline solvent (including mixed systems), for example, an acid anhydride group, a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group, a sulfonamide group, Alternatively, it refers to a polymer substance having a sulfonimide group or the like.

It is usually preferable that these alkaline binders have a high oxidation value of 100 or more. This is because the binder having a high oxidation value easily dissolves in an alkaline solvent or easily swells. Examples of such a binder include styrene: maleic anhydride copolymer, vinyl acetate: maleic anhydride copolymer, vinyl acetate: crotonic acid copolymer, methacrylic acid: methacrylic acid ester copolymer, phenol resin. , Methacrylic acid: styrene: methacrylic acid ester copolymer and the like. The proportion of these binders added to the cyclic bishydrazone compound of the present invention is approximately the same as that of binders for copying machines.

As the sensitizing dye contained in the photosensitive layers 4 and 40, triphenylmethane dyes represented by methyl violet, crystal violet, night blue, Victoria blue, etc., erythrosine, rhodamine B, rhodamine 3R, Acridine dyes typified by acridine orange and flapeosin, thiazine dyes typified by methylene blue and methylene green, oxazine dyes typified by capri blue and meldora blue,
Other examples include cyanine dyes, styryl dyes, pyrylium salt dyes, thiopyrylium salt dyes, and the like. Further, these sensitizing charges may be contained as the charge generating substance 2 in the photosensitive layers 4 and 40. In that case, these sensitizing dyes may be used alone, but in many cases, when used together with the pigment described below, the charge can be generated with higher efficiency.

Examples of the pigment contained in the photosensitive layers 4 and 40 as the photoconductive charge generating substance 2 capable of generating charges with extremely high efficiency by light absorption include various metal phthalocyanines, metal-free phthalocyanines and halogenated compounds. Examples thereof include phthalocyanine pigments such as metal-free phthalocyanine, perylene imide pigments such as perylene imide and perylene anhydride, azo pigments such as bisazo pigments and trisazo pigments, quinacridone pigments and anthraquinone pigments. In particular, when a metal-free phthalocyanine pigment, a titanyl phthalocyanine pigment, a bisazo pigment containing a phlorene or a phlorenone ring, a bisazo pigment composed of an aromatic amine or a trisazo pigment is used, an excellent electrophotographic photoreceptor having high photosensitivity can be obtained. .

Further, various chemical substances are added to the photosensitive layers 4 and 40, if necessary, for the purpose of preventing an increase in residual potential, a decrease in charging potential, a decrease in sensitivity and the like during repeated use. be able to. Such chemicals include:
1-chloroanthraquinone, benzoquinone, 2,3-dichloronaphthoquinone, naphthoquinone, 4,4'-dinitrobenzophenone, 4,4'-dichlorobenzophenone, 4-nitrobenzophenone, 4-nitrobenzalmalondinitrile, α-cyano- Ethyl β- (p-cyanophenyl) acrylate, 9-anthracenylmethylmalondinitrile, 1-cyano-1- (p-nitrophenyl) -2- (p-chlorophenyl) ethylene, 2,7-
Examples thereof include electron-withdrawing compounds such as dinitrofluorenone.

Further, an antioxidant, an anti-curl agent, a leveling agent, etc. may be added to the photosensitive layers 4 and 40, if necessary.

Materials for the intermediate layer 7 include casein, polyvinyl butyral, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon). Etc.), polyurethane, gelatin aluminum oxide and the like can be used.

The electrophotographic photosensitive member of the present invention is a metal drum,
On a conductive support 1 composed of a metal plate, a paper or a plastic film that has been subjected to conductive processing, the cyclic bishydrazone compound of the present invention is contained with the aid of the above-mentioned binder capable of forming a polymer film. It is produced by forming the photosensitive layers 4 and 40 into a film shape. In this case, the photosensitive layer material containing the cyclic bishydrazone compound of the present invention is dissolved or dispersed in a suitable coating solvent to prepare a coating liquid, and the coating liquid is coated on the conductive support 1 and dried. Thus, the photosensitive layers 4 and 40 are formed.

As the coating solvent, aromatic hydrocarbons such as benzene, toluene, xylene and monochlorobenzene, halogenated hydrocarbons such as dichloromethane and dichloroethane, dioxane, dimethoxymethyl ether, dimethylformamide and the like may be used alone or Two or more types can be mixed and used. Also, if necessary,
It is also possible to further add and use a solvent such as alcohols, acetonitrile and methyl ethyl ketone. Further, in order to improve the sensitivity of the electrophotographic photosensitive member, it is desirable to add a substance that imparts plasticity to the above-mentioned sensitizer or binder to form a uniform film.

Hereinafter, more specific embodiments of the present invention will be described, but the present invention is not limited to these.

(Embodiment 1) In Embodiment 1, the exemplified compound Nos. The cyclic bishydrazone compound shown in 1 was produced.

0.6 g (1.0 equivalent) of 2,5-bisformylbenzo [b] furan was dissolved in 10 ml of ethanol to give 1-amino-2,3-dihydroindole 0.97.
g (2.1 equivalents) and acetic acid (0.05 ml) were added to 60 ° C.
The mixture was heated and stirred at a temperature of ~ 70 ° C for 5 hours.

After completion of the reaction, the produced solid was separated by filtration, thoroughly washed with ethanol, and then recrystallized from ethanol for purification to obtain the target compound No. 1.40 g of the cyclic bishydrazone compound 1 was obtained as a yellow powder (yield 93%).

Exemplified Compound No. thus obtained
The structural confirmation of the cyclic bishydrazone compound of 1 is 1H-N
MR, usually 13C-NMR, DEPT13513C-N
This was done by measuring the MR. The measurement result of 1 H-NMR is shown in FIG.
The measurement result of R is shown in FIG. 7 and Table 6 below.
The results of NMR measurement are shown in FIG. 8 and Table 7 below.

[0082]

[Table 5]

[0083]

[Table 6]

[0084]

[Table 7]

These NMR signals correspond to the target compound No. The structure of the cyclic bishydrazone compound of 1 is well supported.

In this Embodiment 1, the exemplified compounds N in Table 1 were used.
o. Although the production of the cyclic bishydrazone compound shown in 1 is described, the other cyclic bishydrazone compounds of the present invention represented by the above general formula (I) can be produced in the same manner.

(Embodiment 2) In Embodiment 2, as the charge generation substance 3 contained in the charge transfer layer 6 shown in FIG. By forming the photosensitive layer 4 having a laminated structure containing each of the cyclic bishydrazone compounds shown in 1, 3, 5, 6, and 9, five types of electrophotographic photosensitive members were manufactured.

First, 1% THF in which polyvinyl butyral resin (manufactured by Nissin Chemical Industry Co., Ltd., S-REC B) was dissolved.
In a (tetrahydrofuran) solution, the following structural formula (VI
The bisazo pigment represented by I) is added in the same weight as the resin,
A coating liquid was prepared by dispersing the mixture in a paint conditioner (manufactured by Red Level Co.) with glass beads having a diameter of 1.5 mm for about 2 hours.

[0089]

[Chemical 7]

This coating solution was applied onto the conductive support 1 made of a polyester film (thickness: 80 μm) vapor-deposited with aluminum and dried. The film thickness of the charge generation layer 5 thus obtained was 0.2 μm.

Next, the exemplified compound No. 1, 3,
1 g each of the cyclic bishydrazone compounds shown in 5, 6, and 9
And polyarylate resin (Unitika; U-100)
1.2 g and 1.2 g were dissolved in methylene chloride to prepare a 15% solution, and five types of coating solutions were prepared. Each coating solution was applied onto the charge generation layer 5 with a squeegee doctor and dried. The film thickness of the charge transfer layer (resin-cyclic bishydrazone compound solid solution phase) 6 thus obtained was 25 μm. As described above, the photosensitive layer 4 having a laminated structure was formed, and five types of electrophotographic photosensitive members were obtained.

The electrophotographic characteristics of each of the obtained electrophotographic photoconductors were evaluated using an electrostatic recording paper tester (Kawaguchi Denki Co., Ltd .; SP-428). Measurement condition is applied voltage: -6
kV, static: No. 3, the exposure amount E100 (lux seconds) required to attenuate from −700 V to −100 V by irradiation with white light (irradiation light: 5 Lux) and the initial potential V0 (−V) were measured. In addition, the exposure amount E10 was obtained after the same operation was performed 10,000 times with one cycle of charge-elimination (charge-eliminating light: irradiation with white light of 40 lux for 1 second).
0 (lux seconds) and initial potential V0 (-volt) were measured. The measurement results are shown in Table 8 below.

[0093]

[Table 8]

From Table 8 above, it was found that each of the electrophotographic photosensitive members of this embodiment had good photosensitivity, high chargeability, and excellent repeatability.

(Embodiment 3) In Embodiment 3, as the charge generating substance 3 contained in the charge transfer layer 6 shown in FIG. By forming the photosensitive layer 4 having a laminated structure containing the cyclic bishydrazone compound shown in 4 above, an electrophotographic photosensitive member was manufactured.

First, in 30 ml of an ethyl acetate solution in which 0.3 g of a vinyl chloride: vinyl acetate copolymer resin (Sekisui Chemical Co., Ltd .; S-Rex M) was dissolved, an X-type metal-free phthalocyanine (Dainippon Ink and Co .; Fast Genblue 812
0) 0.4 g was added and dispersed in a paint conditioner (manufactured by Red Level Co.) for about 20 minutes to prepare a coating solution. This coating solution was applied onto the conductive support 1 made of a polyester film on which aluminum was vapor deposited and dried. The film thickness of the charge generation layer 5 thus obtained was 0.4 μm.

Next, the exemplified compound No. 1 in Table 1 was used. A polyarylate layer containing 50% by weight of the cyclic bishydrazone compound shown in 4 was formed on the charge generation layer 5. As described above, an electrophotographic photosensitive member provided with the photosensitive layer 4 having a laminated structure was obtained.

Regarding the spectral sensitivity at 780 nm of the obtained electrophotographic photosensitive member, the energy E required to halve the potential was calculated.
When the initial potential V0 (−volt) when applied to 50 and −6 kV was obtained, V0 = 720 (−volt), E5
It was 0 = 0.24 (μJ / cm ² ), which was an electrophotographic photosensitive member having extremely high sensitivity and high charging property.

Further, a laser printer (manufactured by Sharp Corporation; WD-580P) was remodeled, and the electrophotographic photosensitive member of this embodiment was attached to the drum portion, and continuous blank copy (Non
After performing Copy Aging 10,000 times, the degree of initial potential drop and sensitivity drop was examined, and V0 = 7
10 (-volt), E50 = 0.25 (μJ / cm ² ).
It was found that it has very excellent repeatability.

(Embodiment 4) In Embodiment 4, as the charge generating substance 3 shown in FIG.
o. A single-layer photosensitive layer 4 containing each of the cyclic bishydrazone compounds shown in Nos. 2, 3, 4, and 8 was formed to produce four types of electrophotographic photosensitive members.

First, 1.1 g of polyarylate resin represented by the following structural formula (VIII), N, N-3,5-xylyl-3,4-xylyl-3,4,9,10-perylenetetracarboxylic imide 0 0.15 g and 0.05 g of antioxidant (BHQ) were dissolved in methylene chloride to prepare a coating solution in which the imide compound was partially dispersed.

[0102]

[Chemical 8]

In the above formula, n is an integer of 100 to 10,000, although it depends on the conditions at the time of polymer synthesis.

This coating solution was applied onto the conductive support 1 having the aluminum substrate surface anodized (alumite layer thickness 7 μm) using an applicator and dried.
The film thickness of the photosensitive layer 40 thus obtained was 20 μm. As described above, the photosensitive layer 40 composed of a single layer was formed, and four types of electrophotographic photosensitive members were obtained.

The electrophotographic characteristics of each of the obtained electrophotographic photosensitive members were evaluated by using an electrostatic recording paper testing device (Kawaguchi Denki KK; SP-428). Measurement conditions are applied voltage: +
5.5 kV, static: No. 3 and the exposure amount E100 (lux / sec) required to attenuate from +700 V to +100 V with white light irradiation (irradiation light 5 lux)
Was measured. In addition, a blank copy test was performed 10,000 times to examine the degree of decrease in the sensitivity E100 (lux · sec).
The measurement results are shown in Table 9 below.

[0106]

[Table 9]

From Table 9 above, it was found that the electrophotographic photoreceptors of this embodiment all had good photosensitivity even in positive charging and excellent repeatability.

[0108]

As described above in detail, the cyclic bishydrazone compound having a benzofuran skeleton of the present invention is a novel compound which has never been obtained. Further, according to the method for producing a cyclic bishydrazone compound of the present invention and the method for producing an intermediate thereof, the cyclic bishydrazone compound of the present invention can be produced very easily in a high yield.

According to the electrophotographic photoreceptor of the present invention in which the cyclic bishydrazone compound of the present invention is contained in the photosensitive layer, the sensitivity and the charging property are high, and the deterioration of the photosensitivity hardly occurs in repeated use. An excellent electrophotographic photoreceptor can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an electrophotographic photosensitive member of the present invention.

FIG. 2 is a sectional view showing another embodiment of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a sectional view showing another embodiment of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a sectional view showing another embodiment of the electrophotographic photosensitive member of the present invention.

FIG. 5 is a sectional view showing another embodiment of the electrophotographic photosensitive member of the present invention.

6 is an exemplary compound No. 1 is a 1 H-NMR spectrum of the cyclic bishydrazone compound of 1.

FIG. 7: Exemplified Compound No. It is a usual 13 C-NMR spectrum of the cyclic bishydrazone compound of 1.

FIG. 8: Exemplified Compound No. It is a DEPT13513C-NMR spectrum of the cyclic bishydrazone compound of 1.

[Explanation of symbols]

1 Conductive support 2 Charge generation material 3 Charge transfer material 4,40 Photosensitive layer 5 Charge generation layer 6 Charge transfer layer 7 Middle class

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takatsugu Obata 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Sharp Corporation (56) References JP-A-7-92707 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C07D 307/81 C07D 405/14 G03G 5/06 328 CA (STN) REGISTRY (STN)

Claims (8)

(57) [Claims] 1. A photosensitive layer provided on a conductive support,
An electrophotographic photoreceptor containing a cyclic bishydrazone compound represented by the following general formula (I). [Chemical 1] (In the formula, Z is 2 necessary for forming a heterocyclic ring which may have a substituent or a condensed heterocyclic ring which may have a substituent.
Represents an atomic group having a valent group, a is an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, and 1 carbon atoms
To 3 dialkylamino groups, halogen atoms or hydrogen atoms, and n is 1, 2 or 3. However, n is 2
In the above cases, each of the plurality of a's may be the same or different, and may form a ring with each other. ) 2. The electrophotographic photosensitive member according to claim 1, wherein the cyclic bishydrazone compound represented by the general formula (I) is a compound represented by the following general formula (II). [Chemical 2] (In the formula, Z, a and n have the same meanings as described in claim 1.) 3. The electrophotographic photosensitive member according to claim 1, wherein the cyclic bishydrazone compound represented by the general formula (I) is a compound represented by the following general formula (III). [Chemical 3] (In the formula, b is an alkyl group having 1 to 3 carbon atoms, and has 1 carbon atom.
To 3 alkoxy groups, C1 to C3 dialkylamino groups, halogen atoms or hydrogen atoms, and m is 1,
Indicates 2, 3, 4, 5, 6, 7 or 8. However, m is 2
In the above case, each of the plurality of b's may be the same or different, and may form a ring with each other. a and n have the same meanings as defined in claim 1. ) 4. The electrophotographic photosensitive member according to claim 1, wherein the cyclic bishydrazone compound represented by the general formula (I) is a compound represented by the following general formula (IV). [Chemical 4] (In the formula, m represents 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. a and n have the same meanings as those defined in claim 1. b represents in claim 3. It is synonymous with what is shown.) 5. The photosensitive layer has a laminated structure of a charge generating layer containing a charge generating substance and a charge transferring layer containing a charge transferring substance, and the charge transferring substance is composed of the cyclic bishydrazone compound. The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein 6. The photosensitive layer comprises a single layer containing a charge generating substance and a charge transfer substance, and the charge transfer substance comprises the cyclic bishydrazone compound.
The electrophotographic photosensitive member according to any one of 1. 7. A cyclic bishydrazone compound represented by the following general formula (I). [Chemical 1] (In the formula, Z, a and n have the same meanings as described in claim 1.) 8. A method for producing a cyclic bishydrazone compound represented by the following general formula (I), which comprises 2-formylbenzo [b] represented by the following general formula (V).
A method for producing a cyclic bishydrazone compound, which comprises reacting a furan compound derivative with a cyclic hydrazine reagent represented by the following general formula (VI). [Chemical 1] (In the formula, Z, a and n have the same meanings as shown in claim 1. ) (In the formula, a and n have the same meanings as shown in claim 1.) (In the formula, Z, a and n have the same meanings as defined in claim 1.