JP3104243B2 - Photoconductor - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photoreceptor having a photosensitive layer containing a novel hydrazone compound.

2. Description of the Related Art Generally, in electrophotography, an electrostatic latent image is formed by charging and exposing a photosensitive layer surface of a photoreceptor, and then developing with a developer to visualize the image. A direct method of fixing a photoreceptor to obtain a copy image, a powder image transfer method of transferring a visible image on a photoreceptor onto a transfer material such as paper, and fixing the transferred image to obtain a copy image, or a photosensitive method. 2. Description of the Related Art There is known an electrostatic transfer method in which an electrostatic latent image on a body is transferred onto transfer paper, and the electrostatic latent image on the transfer paper is developed and fixed.

As a material constituting a photosensitive layer of a photoreceptor used in this type of electrophotography, conventionally, selenium, cadmium sulfide,
Inorganic photoconductive materials such as zinc oxide are known.

These photoconductive materials have a number of advantages, such as less charge dissipation in a dark place, or the ability to quickly dissipate charge by light irradiation, but have various disadvantages. For example, in the case of a selenium-based photoconductor, manufacturing conditions are difficult, the manufacturing cost is high, and the selenium-based photoconductor is susceptible to heat and mechanical shock.
Cadmium sulfide photoreceptors and zinc oxide photoreceptors do not provide stable sensitivity in humid environments, and dyes added as sensitizers cause charge deterioration due to corona charging and photobleaching due to exposure, resulting in long-term However, there is a disadvantage that stable characteristics cannot be provided over a wide range.

On the other hand, various organic photoconductive polymers such as polyvinyl carbazole have been proposed, but these polymers are superior to the above-mentioned inorganic photoconductive materials in terms of film-forming properties and lightness. However, they are still inferior to inorganic photoconductive materials in terms of sufficient sensitivity, durability and stability due to environmental changes.

The low molecular weight organic photoconductive compound is preferable in that the physical properties of the film or the electrophotographic properties can be controlled by selecting the type and composition ratio of the binder used in combination. Since it is used together with the material, high compatibility with the binder is required.

A photoreceptor in which these high molecular weight and low molecular weight organic photoconductive compounds are dispersed in a binder resin has drawbacks such as a large residual potential due to many carrier traps and low sensitivity. Therefore, it has been proposed to solve the above-mentioned drawbacks by blending a charge transport material with a photoconductive compound.

Also, a function-separated type photoreceptor has been proposed in which the charge generation function and the charge transport function of the photoconductive function are shared by different substances. In such a function-separated type photoreceptor, many organic compounds are mentioned as the charge transporting material used for the charge transporting layer, but there are various problems in practice. For example, 2,5-bis (P-diethylaminophenyl) 1,3,4-oxadiazole described in U.S. Pat. No. 3,189,447 has low compatibility with a binder and tends to crystallize. U.S. Patent 3,820,989
The diarylalkane derivative described in Japanese Patent Application Laid-Open Publication No. H08-27139 has good compatibility with a binder, but changes in sensitivity when used repeatedly. In addition, the hydrazone compound described in JP-A-54-59143 has a relatively good residual potential characteristic, but has a drawback of poor charging ability and repetition characteristics. As described above, in reality, there is almost no low-molecular-weight organic compound having practically preferable characteristics in producing a photoreceptor.

Problems to be Solved by the Invention The present invention has been made in view of the above facts, and contains a hydrazone compound having excellent compatibility with a binder and charge transporting ability as a photoconductive substance, and has sensitivity and charging ability. It is an object of the present invention to provide a photoreceptor having excellent electrophotographic characteristics, low fatigue deterioration when used repeatedly, and stable electrophotographic characteristics.

Means for Solving the Problems The present invention provides a photosensitive member having a photosensitive layer containing a hydrazone compound represented by the following general formula [I] on a conductive support: [Wherein, Ar ₁ and Ar ₅ independently represent an aryl group which may have a substituent; Ar ₂ , Ar ₃ and Ar ₄ may independently have a substituent Represents an arylene group; R ₁ and R ₂ independently represent an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, each of which may have a substituent; R ₃ is a hydrogen atom Represents an alkyl group or an aryl group; R ₄ may have a substituent,
X represents an alkyl group, an aralkyl group, an aryl group or a heterocyclic group; X represents —O—, —S—, — (R ₅ ) C (R ₆ ) —,
—N (R ₇ ) — (wherein, R ₅ and R ₆ independently represent a hydrogen atom, an alkyl group or an aryl group; R ₇ represents an alkyl group, an aralkyl group or an aryl group);
There -O -, - S-, or _{- (R 5) C (R} 6) - a, and Ar
_{When 1} , R ₁ and R ₂ are unsubstituted phenyl groups,
There -O -, - S-, or _{- (R 5) C (R} 6) - a, and Ar
Except when ₁ or R ₁ is a hydrazone group. ].

In the above general formula [I], Ar ₁ and Ar ₅ independently represent an aryl group, for example, a phenyl group, a tolyl group, a naphthyl group and the like. These groups may have a substituent, for example, an alkyl group such as a methyl group, an ethyl group, or a propyl group, or an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group.

Ar ₂ , Ar ₃ and Ar ₄ independently represent an arylene group such as a phenylene group, a naphthalene group and the like. These groups may have a substituent, for example, an alkyl group such as a methyl group, an ethyl group, or a propyl group, or an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group.

R ₁ , R ₂ and R ₄ are each independently an alkyl group such as a methyl group, an ethyl group or a propyl group; an aralkyl group such as a benzyl group, a phenethyl group, a methylbenzyl group or a methoxybenzyl group; an aryl group; For example, phenyl group, tolyl group, naphthyl group and the like; heterocyclic group such as thiophene,
Represents a group such as pyrrole pyridine, carbazole, furan, and dioxaindane. These groups may have a substituent, for example, an alkyl group such as a methyl group, an ethyl group, or a propyl group; or a heterocyclic group such as thiophene, pyrrole, furan, or pyridine.

R ₃ represents a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group or the like, or an aryl group such as a phenyl group, a tolyl group, a naphthyl group or the like.

X is, -O -, - S -, - (R 5) C (R 6) -, - N
(R ₇ ) represents a divalent group such as-. In the formula, R ₅ and R ₆ independently represent a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, a propyl group or the like or an aryl group such as a phenyl group, a tolyl group, a naphthyl group or the like. R ₇ is an alkyl group,
For example, it represents an aralkyl group such as a methyl group, an ethyl group, or a propyl group, for example, a benzyl group, a phenethyl group, a methylbenzyl group, a methoxybenzyl group, or an aryl group, for example, a phenyl group, a tolyl group, or a naphthyl group. These groups may have a substituent, an alkyl group such as a methyl group or an ethyl group, or a heterocyclic group such as thiophene. However,
X is -O -, - S-, or _{- (R 5) C (R} 6) - a, and
Excluded when Ar ₁ , R ₁ and R ₂ are unsubstituted phenyl groups.

Preferred specific examples of the hydrazone compound represented by the general formula [I] of the present invention include, for example, those having the following structural formulas, and the examples thereof are intended to limit interpretation of the present invention. is not.

The compound represented by the general formula [I] of the present invention can be easily synthesized by a usual method.

For example, the following general formula [II]: [Wherein R ₁ , R ₂ , R ₃ , Ar ₁ , Ar ₂ , Ar ₃ , R ₄ and X have the same meanings as in the above [I]] and the following general formula [III]: [Wherein, Ar ₅ and R ₄ have the same meanings as [I]] can be synthesized by subjecting a hydrazine compound represented by the following formula to a dehydration condensation reaction.

The reaction is generally carried out by removing water produced using an aromatic solvent such as benzene, toluene or xylene, or an alcoholic solvent such as methanol, ethanol, propanol or butanol, or removing potassium water, potassium acetate, p-toluenesulfonic acid, or the like. This is performed using a catalyst such as acetic acid.

The photoreceptor of the present invention has a photosensitive layer containing one or more hydrazone compounds represented by the general formula [I]. Also, good electrophotographic properties can be obtained by combining with other charge transporting materials such as styryl compounds and other hydrazone compounds.

Various types of photoconductors are known, but the photoconductor of the present invention may be any of those photoconductors. For example, a charge-generating material on a support, a single-layer photoreceptor having a photosensitive layer formed by dispersing a hydrazone compound in a resin binder,
There is a so-called laminated photoreceptor in which a charge generation layer mainly containing a charge generation material is provided on a support, and a charge transport layer is provided thereon. Although the hydrazone compound of the present invention is a photoconductive substance, it acts as a charge transporting material and can transport charge carriers generated by absorbing light extremely efficiently.

In order to produce a single-layer photoreceptor, the fine particles of the charge generating material may be dispersed in a resin solution or a solution in which the charge transporting material and the resin are dissolved, and this may be coated on a conductive support and dried. At this time, the thickness of the photosensitive layer is 3 to 30 μm, preferably 5 to 20 μm. If the amount of the charge generating material used is too small, the sensitivity is poor, and if it is too large, the chargeability is deteriorated, the mechanical strength of the photosensitive layer is reduced, and the proportion in the photosensitive layer is 1 part by weight of the resin. 0.01 to 3 parts by weight, preferably 0.2 to 2 parts by weight.

To produce a laminated photoreceptor, a charge generation material is vacuum-deposited on a conductive support, or dissolved in a solvent such as an amine and applied, or a pigment is applied to a suitable solvent or a binder if necessary. It is obtained by applying and drying a coating solution prepared by dispersing in a solution in which a resin is dissolved, and then applying and drying a solution containing a charge transport material and a binder thereon. In the case of performing vacuum deposition, phthalocyanines such as metal-free phthalocyanine, titanyl phthalocyanine, and aluminum chlorophthalocyanine are used. When dispersing, for example, a bisazo pigment is used.

At this time, the thickness of the charge generation layer is 4 μm or less, preferably 2 μm or less, and the thickness of the charge transport layer is 3 to 30 μm.
Preferably, it is 5 to 20 μm.

The ratio of the charge transporting material in the charge transporting layer is 0.2 to 2 parts by weight, preferably 0.3 to 1.
3 parts by weight.

The photoreceptor of the present invention, together with a binder resin, halogenated paraffin, polychlorinated biphenyl, dimethylnaphthalene, dibutyl phthalate, plasticizers such as O-terphenyl, chloranil, tetracyanoethylene, 2,4,7-trinitrofluorenone, 5 , 6-dicyanobenzoquinone, tetracyanoquinodimethane, tetrachlorophthalic anhydride,
Electron withdrawing sensitizers such as 3,5-dinitrobenzoic acid, and sensitizers such as methyl violet, rhodamine B, cyanine dyes, pyrylium salts, and thiapyrylium salts may be used.

Further, an antioxidant, an ultraviolet absorber, a dispersing aid, an anti-settling agent, and the like may be appropriately used.

As the electrically insulating binder resin used in the present invention, a binder such as a thermoplastic resin or a thermosetting resin known per se, which is electrically insulating, a photocurable resin or a photoconductive resin can be used. .

Examples of suitable binder resins include, but are not limited to, saturated polyester resins, polyamide resins, acrylic resins, ethylene-vinyl acetate resins, ionically crosslinked olefin copolymers (ionomers), styrene-butadiene blocks. Copolymer, polycarbonate, vinyl chloride
Thermoplastic resin such as vinyl acetate copolymer, cellulose ester, polyimide, styrene resin; epoxy resin,
Thermosetting resins such as urethane resins, silicone resins, phenolic resins, melamine resins, xylene resins, alkyd resins, thermosetting acrylic resins; photocurable resins; photoconductive resins such as polyvinylcarbazole, polyvinylpyrene, polyvinylanthracene, and polyvinylpyrrole Resin.

These can be used alone or in combination.

These electrically insulative resins were measured alone to be 1 × 10 ¹² Ω
-It is desirable to have a volume resistance of not less than cm.

As the charge generating material, bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes,
Xanthene dyes, cyanine dyes, styryl dyes,
Pyrylium dyes, azo pigments, quinacridone pigments,
Indigo pigments, perylene pigments, polycyclic quinone pigments,
Bisbenzimidazole pigments, indathrone pigments,
Organic substances such as squarium salt pigments, azulene pigments, phthalocyanine pigments, and inorganic substances such as selenium, selenium alloys such as selenium, tellurium, selenium and arsenic, cadmium sulfide, cadmium selenide, zinc oxide, and amorphous silicon. Can be In addition, any material that absorbs light and generates charge carriers at an extremely high probability can be used.

As the conductive support used in the photoreceptor of the present invention,
Copper or aluminum, silver, iron, zinc, nickel or other metal or alloy foils or plates in the form of sheets or drums are used, or these metals are vacuum deposited or electroless plated on plastic films or the like. Or a layer in which a layer of a conductive compound such as a conductive polymer, indium oxide or tin oxide is provided on a support such as paper or a plastic film by coating or vapor deposition.

Examples of the constitution of a photoreceptor using the hydrazone compound of the present invention are schematically shown in FIGS.

FIG. 1 shows a photoconductor in which a photosensitive layer (4) in which a photoconductive material (3) and a charge transport material (2) are mixed with a binder is formed on a substrate (1). The hydrazone compounds of the present invention have been used.

FIG. 2 shows a function-separated type photoreceptor having a charge generation layer (6) as a photosensitive layer and a charge transport layer (5). The charge transport layer (5) is formed on the surface of the charge generation layer (6). ing.

The hydrazone compound of the present invention is blended in the charge transport layer (5).

FIG. 3 shows a function-separated type photoreceptor having a charge generation layer (6) and a charge transport layer (5) as in FIG.
Contrary to the figure, the charge generation layer (6) is provided on the surface of the charge transport layer (5).
Are formed.

FIG. 4 shows that the surface protective layer (7) is further provided on the surface of the photoreceptor of FIG. 1, and the photosensitive layer (4) has a charge generation layer (6) and a charge transport layer (5). A function-separated type photoconductor may be used.

FIG. 5 shows that an intermediate layer (8) is provided between the substrate (1) and the photosensitive layer (4). The intermediate layer (8) has improved adhesion, improved coating properties, and protected the substrate. For improving the charge injection property from the substrate to the photosensitive layer.

As a material used for the intermediate layer, polyimide, polyamide, nitrocellulose, polyvinyl butyral, a polymer such as polyvinyl alcohol as it is, or a dispersion of a low-resistance compound such as tin oxide or indium oxide, aluminum oxide, zinc oxide, A deposited film of silicon oxide or the like is suitable.

 The thickness of the intermediate layer is desirably 1 μm or less.

As a material used for the surface protective layer, a polymer such as an acrylic resin, a polyaryl resin, a polycarbonate resin, or a urethane resin as it is, or a material in which a low-resistance compound such as tin oxide or indium oxide is dispersed is suitable.

Also, an organic plasma polymerized film can be used. The organic plasma polymer film may contain oxygen, nitrogen, halogen, and atoms of Groups 3 and 5 of the Periodic Table as appropriate.

 The thickness of the surface protective layer is desirably 5 μm or less.

Hereinafter, the present invention will be described with reference to examples. In the examples, “parts” means “parts by weight” unless otherwise specified.

Example 1 Bisazo compound represented by the following general formula [A] 0.45 part and 0.45 part of a polyester resin (Vylon 200; manufactured by Toyobo Co., Ltd.) were dispersed together with 50 parts of cyclohexanone by a sand glider. The obtained dispersion of the bisazo compound was applied on a 100-μm-thick aluminized mylar using a film applicator so that the dry film thickness became 0.3 g / m ^2, and then dried. A solution prepared by dissolving 70 parts of a hydrazone compound [1] and 70 parts of a polycarbonate resin (K-1300; manufactured by Teijin Chemicals, Ltd.) in 400 parts of 1,4-dioxane was placed on the charge generation layer thus obtained. Coating was performed so that the thickness became 16 μm to form a charge transport layer. In this way, an electrophotographic photoreceptor having two photosensitive layers was obtained.

The photoreceptor obtained in this manner is used in a commercially available electrophotographic copying machine (EP
-470Z: using Minolta Camera Co., Ltd.), was corona charged at -6 KV, the initial surface potential V ₀ (V), the exposure amount required to initial potential to the _{1/2 E 1/2 (lux ·} sec) The decay rate DDR ₁ (%) of the initial potential when left in the dark for 1 second was measured.

Example 2 A photoreceptor having the same constitution as in Example 1 except that the hydrazone compound [3] was used instead of the hydrazone compound [1] used in Example 1 was produced.

With respect to the photoreceptor thus obtained, V ₀ , E _1/2 , and DDR ₁ were measured in the same manner as in Example 1.

Example 3 Bisazo compound represented by the following general formula [B] 0.45 part and 0.45 part of a polystyrene resin (molecular weight: 40000) were dispersed together with 50 parts of cyclohexanone by a sand glider. The dispersion of the obtained bisazo compound is 100 in thickness.
Using a film applicator, the composition was applied on a micronized aluminized mylar using a film applicator to a dry film thickness of 0.3 g / m ² and then dried. On the charge generation layer thus obtained, 70 parts of a hydrazone compound [5] and a polyarylate resin (U
A solution in which 70 parts of -100 (manufactured by Unitika) was dissolved in 400 parts of 1,4-dioxane was applied so as to have a dry film thickness of 16 μm to form a charge transport layer. Thus, an electrophotographic photoreceptor having a two-layer photosensitive layer was produced.

Examples 4 and 5 Photoreceptors having the same constitution as in Example 3 but using the hydrazone compounds [6] and [7] instead of the hydrazone compound [5] used in Example 3 were produced. did.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Example 6 Polycyclic quinone pigment represented by the following general formula [C] 0.45 parts, polycarbonate resin (Panlite K-13000:
0.45 part (manufactured by Teijin Chemicals Ltd.) was dispersed with a sand mill together with 50 parts of dichloroethane.

The resulting dispersion of the polycyclic quinone pigment was applied onto an aluminized mylar having a thickness of 100 μm using a film applicator so that the dry film thickness became 0.4 g / m ^2, and then dried. On the charge generation layer thus obtained, 60 parts of a hydrazone compound [8] and a polyarylate resin (U-10
A solution in which 50 parts of (0: manufactured by Unitika) was dissolved in 400 parts of 1,4-dioxane was applied so as to have a dry film thickness of 18 μm, and dried to form a charge transport layer.

Thus, an electrophotographic photosensitive member having a two-layer photosensitive layer was produced.

It was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Examples 7 and 8 Photoreceptors having the same constitution as in Example 6 except that hydrazone compounds [13] and [15] are used instead of hydrazone compound [8] used in Example 6 were prepared. did.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Example 9 A perylene pigment represented by the following general formula [D] 0.45 parts, butyral resin (BX-1: Sekisui Chemical Co., Ltd.)
45 parts were dispersed by a sand mill together with 50 parts of dichloroethane.

Using a film applicator on the resulting perylene-based pigment dispersion on an aluminized mylar having a thickness of 100 μm,
The coating was applied so that the dry film thickness became 0.4 g / m ^2, and then dried.
A solution obtained by dissolving 50 parts of a hydrazone compound [16] and 50 parts of a polycarbonate resin (PC-Z: manufactured by Mitsubishi Gas Chemical Company) in 400 parts of 1,4-dioxane was dried on the charge generation layer thus obtained. Coating was performed so that the film thickness became 18 μm to form a charge transport layer.

Thus, an electrophotographic photosensitive member having a two-layer photosensitive layer was produced.

It was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Examples 10 and 11 Photoreceptors having the same constitution as in Example 9 except that hydrazone compounds [17] and [18] are used instead of hydrazone compound [16] used in Example 9 were prepared. did.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Example 12 0.45 part of titanyl phthalocyanine, butyral resin (BX
-1: Sekisui Chemical Co., Ltd.) was dispersed by a sand mill together with 50 parts of dichloroethane.

The dispersion of the obtained phthalocyanine pigment is 100 μm thick.
Was applied using a film applicator to a dry film thickness of 0.3 g / m ² and then dried. On the charge generating layer thus obtained, 50 parts of a hydrazone compound [20] and a polycarbonate resin (PC-
A solution prepared by dissolving 50 parts of Z (manufactured by Mitsubishi Gas Chemical Company) in 400 parts of 1,4-dioxane was applied to a dry film thickness of 18 μm to form a charge transport layer.

Thus, to prepare an electrophotographic photosensitive member having a photosensitive layer composed of two layers, V _0, E _1/2 in the same manner as in Example 1,
DDR ₁ was measured.

Example 13 A photoconductor having the same constitution as in Example 12 except that the hydrazone compound [22] was used instead of the hydrazone compound [20] used in Example 12 was produced.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 1.

Example 14 50 parts of copper phthalocyanine and 0.2 part of tetranitro copper phthalocyanine were dissolved in 500 parts of 98% concentrated sulfuric acid with sufficient stirring, and the mixture was poured into 5000 parts of water to prepare a photoconductive material composition of copper phthalocyanine and tetranitro copper phthalocyanine. After sieving, the mixture was filtered, washed with water, and dried at 120 ° C. under reduced pressure.

10 parts of the photoconductive composition thus obtained was mixed with a thermosetting acrylic resin (Acrydic A405: manufactured by Dainippon Ink).
5 parts, melamine resin (Super Beckamine J820: manufactured by Dainippon Ink) 7.5 parts, hydrazone compound [23] 15 described above
Parts were mixed in a ball mill pot with 100 parts of a mixed solvent obtained by mixing methyl ethyl ketone and xylene in the same amount, and dispersed for 48 hours to prepare a photosensitive coating solution. The coating solution was applied on an aluminum substrate, dried and dried. A photosensitive layer having a thickness of about 15 μm was formed to prepare a photosensitive member.

The thus obtained photosensitive member, the same method as that in Example 1, except V ₀ and subjected to corona charging at _{+ 6Kv, E 1/2,} DDR
₁ was measured.

Example 15 A photoconductor having the same structure as that of Example 14 except that a hydrazone compound [25] was used instead of the hydrazone compound [23] used in Example 14 was produced.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 14.

Comparative Examples 1 to 4 In the same manner as in Example 14, the same composition was used, except that the following compounds [E], [F], [G], and [H] were used instead of the hydrazone compounds used in Example 14. A photoconductor was prepared in the same manner as that of Example 14 except for using it.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 14.

Comparative Examples 5 to 7 The same configuration as in Example 14, except that the following hydrazone compounds [I], [J] and [K] were used instead of the hydrazone compound [23] used in Example 14 A photoconductor was prepared in the same manner as that of Example 14 except for using it.

The thus obtained photosensitive member was measured _{V 0, E 1/2,} DDR 1 in the same manner as in Example 14.

V _{0 of} the photoreceptors obtained in Examples 1 to 15 and Comparative Examples 1 to 7,
Measurement results of the E _1/2, DDR ₁ are summarized in Table 1.

As can be seen from Table 1, the photoreceptor of the present invention has a sufficient charge retention ability even in a laminated type or a single-layer type, has a small dark decay rate to such an extent that it can be sufficiently used as a photoreceptor, and has excellent sensitivity. Is clear from the data.

Further, a commercially available electrophotographic copying machine (Minolta Camera: E
(P-350Z) was repeated on the photoreceptor of Example 14 at the time of positive charging. Even when 1000 copies were made, the gradation was excellent in the initial and final images, there was no change in sensitivity, and the image was clear. Thus, it can be seen that the photosensitive member of the present invention has stable repetition characteristics.

Effects of the Invention The present invention has provided a photoconductive compound useful for a photoreceptor.

The photoconductive compound of the present invention is a hydrazone compound,
It is particularly useful as a charge transport material.

The photoreceptor having the hydrazone compound of the present invention has sensitivity,
Excellent photoreceptor characteristics such as charge transportability, initial surface potential, dark decay rate, etc., and little light fatigue due to repeated use.

[Brief description of the drawings]

1 to 5 are schematic views of a photoreceptor according to the present invention. FIGS. 1, 4 and 5 show a dispersion type photoreceptor having a photosensitive layer laminated on a conductive support. 2 and 3 show the structure of a function-separated type photoconductor in which a charge generation layer and a charge transport layer are laminated on a conductive support. DESCRIPTION OF SYMBOLS 1 ... Conductive support, 2 ... Charge transport material 3 ... Photoconductive material, 4 ... Photosensitive layer 5 ... Charge transport layer, 6 ... Charge generation layer 7 ... Surface protective layer, 8 ... Middle class

Claims (1)

(57) [Claims] 1. A photoreceptor having a photosensitive layer containing a hydrazone compound represented by the following general formula [I] on a conductive support: [Wherein, Ar ₁ and Ar ₅ independently represent an aryl group which may have a substituent; Ar ₂ , Ar ₃ and Ar ₄ may independently have a substituent Represents an arylene group; R ₁ and R ₂ independently represent an alkyl group, an aralkyl group, an aryl group or a heterocyclic group, each of which may have a substituent; R ₃ is a hydrogen atom Represents an alkyl group or an aryl group; R ₄ may have a substituent,
X represents an alkyl group, an aralkyl group, an aryl group or a heterocyclic group; X represents —O—, —S—, — (R ₅ ) C (R ₆ ) —,
—N (R ₇ ) — (wherein, R ₅ and R ₆ independently represent a hydrogen atom, an alkyl group or an aryl group; R ₇ represents an alkyl group, an aralkyl group or an aryl group);
There -O -, - S-, or _{- (R 5) C (R} 6) - a, and Ar
_{When 1} , R ₁ and R ₂ are unsubstituted phenyl groups,
There -O -, - S-, or _{- (R 5) C (R} 6) - a, and Ar
Except when ₁ or R ₁ is a phenyl group having a hydrazone group. ]