JPS6024551A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve the photosensitivity and the quality of an image by incorporating a specified bisazo compound into a carrier generating phase and a specified hydrazone compound into a carrier transferring phase. CONSTITUTION:A bisazo compound represented by formula I is incorporated into a carrier generating phase, and a hydrazone compound represented by formula IIinto a carrier transferring phase. A photosensitive body having high sensitivity and high spectral sensitivity in the whole visible light region is obtd. by well combining said bisazo compound used as CGM with said hydrazone compound used as CTM. In the formulae, each of Ar<1> and Ar<2> is a carbocyclic aromatic ring; each of R<1> and R<2> is an electron withdrawing group or H; A is a group represented by formula III; X is OH or the like; Y is H, halogen or the like; Z is a carbocyclic aromatic ring; R<3> is H, amino or the like; A' is aryl; n is 1 or 2; m is an integer of 0-4; each of R<7> and R<8> is H or halogen; each of R<9> and R<10> is aryl; and Ar<3> is arylene.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Prior Art The present invention relates to a photoreceptor, such as an electrophotographic photoreceptor, having a photosensitive layer comprising a carrier generation phase and a carrier transport layer.

2. Prior Art According to conventionally known electrophotographic photoreceptors, a carrier-generating substance (hereinafter referred to as "CGM") that absorbs visible light and generates charge carriers (hereinafter simply referred to as "carriers") is used.
Carrier generation M(0) containing carrier generation M(
Hereinafter, it may be referred to as "CGL". ) and CGL of and
A carrier transport layer (hereinafter sometimes referred to as "CTL") containing a gear transport material (hereinafter sometimes referred to as rcTMJ) that transports either or both of positive or negative carriers generated in By combining these, a photosensitive layer is constructed.

In this way, by assigning the two necessary basic functions of carrier generation and carrier transport to the separate layers constituting the photosensitive layer, the range of materials that can be used in the composition of the photosensitive layer can be expanded. In addition to being wide-ranging, it becomes possible to independently select materials or material systems that optimally perform each function. In addition, this also allows for the characteristics required in the electrophotographic process, such as high surface potential when charged, high charge retention capacity, high photosensitivity, and high stability during repeated use. It becomes possible to obtain an electrophotographic photoreceptor having excellent characteristics.

As the above-mentioned photosensitive layer, for example, the following ones are known.

(1) CG composed of amorphous selenium or cadmium sulfide
A structure in which L and CTL made of poly-N-vinylcarbazole are laminated.

(2) CG made of amorphous selenium or cadmium sulfide
A structure in which L and CTL containing 2,4.7-) dinitro-9-fluorenone are laminated.

(3) A structure in which a CGL composed of a perylene derivative and a CTL containing an oxadiazole derivative are laminated (
(See US Pat. No. 3,871,882).

(4) CGL composed of chlordiayan blue or methylskarylium and CTL containing a pyrazoline derivative
(Refer to Japanese Unexamined Patent Publication No. 51-90827) 0 (5) CGL composed of amorphous selenium or an alloy thereof;
A structure in which CTL containing a polyarylalkane aromatic amino compound is laminated (Japanese Patent Application No. 52-14725
Specification No. 1) 0 (6) A structure in which CGL containing a perylene derivative and CTL containing a polyarylalkane-based aromatic amino compound are laminated (Japanese Patent Application No. 19907-1987) 0 Like this Although many functionally separated type photosensitive layers are known, conventional electrophotographic photoreceptors having such photosensitive layers have repetition points. For example, when the electrophotographic photoreceptor is repeatedly subjected to an electrophotographic process, the potential history state of the electrophotographic photoreceptor is not maintained stably, making it impossible to obtain stable image forming characteristics.

Further, the use of specific bisazo compounds as CGM is disclosed in, for example, JP-A-55-117151 and JP-A-54.
- Although disclosed in Publication No. 145142, etc., the CG
Even in combination with CTM, which is said to be able to be combined with M, the above-mentioned drawbacks are still considerable. As can be understood from this, a carrier transporting substance that is effective against a particular carrier-generating substance is not necessarily effective against other carrier-generating substances, and It cannot be said that a carrier-generating substance that is effective against other carrier-transporting substances is also effective against other carrier-transporting substances. If the combination of both substances is inappropriate, the electrophotographic sensitivity will be low, and the discharge efficiency will be poor especially in low electric fields, so the so-called residual potential will be large, and in the worst case, it will be used repeatedly. Each time it is used, a potential accumulates, making it practically unusable for electrophotography.

In this way, it is thought that there is no lawful means of selecting a suitable combination of the constituent substances of the carrier generation phase and the constituent substances of the carrier transport layer, and an advantageous combination is determined practically from among many substance groups. There is a need to.

On the other hand, in a photoreceptor using poly-N-vinylcarbazole as the CTM, for example as in (1) above, the film is hard, brittle, and cracked because poly-N-vinylcarbazole lacks flexibility. It has the disadvantage that it easily peels off and has poor durability. Therefore,
When a plasticizer is added to increase flexibility, it has the disadvantage that electrophotographic properties deteriorate, such as increased residual potential and capri in the image.

In addition, using a low molecular weight organic compound as a charge transport material,
Efforts have been made to obtain an electrophotographic photoreceptor having excellent electrophotographic properties and film strength by using a polymeric binder and a substance that generates an arbitrary charge in combination.
However, as a low molecular weight charge transport material, for example 2,5
-bis(p-diethylamino7aer)-1,3,4
-Oxadiazole derivatives such as oxadiazole are selected and used as preferred substances, but these have poor compatibility with polymeric binders, resulting in easy sale and poor thermal stability. There is a drawback.

Further, the technology of using a pyrazoline compound as a photoconductive material in an electrophotographic photoreceptor is disclosed in, for example, US Pat.
It is described in the specification of No. 0.729 and is well known, but it is used as a material that absorbs light and generates a charge and transports the charge. It is not what is used.

Furthermore, the technique of using a pyrazoline compound as a charge transport material is known, for example, as described in U.S. Pat. No. 3,837,851, but the pyrazoline compound used here is generally The pyrazoline compound has poor compatibility with the polymeric binder added to improve the physical properties, and when the amount of polymeric binder necessary to obtain the desired physical properties is used, the pyrazoline compound thermally crystallizes, and as a result, the charge The transport layer becomes turbid, resulting in a decrease in light transmittance and, in turn, a decrease in the sensitivity of the photoreceptor.

Further, a charge transport layer which causes turbidity as described above generally has poor layer uniformity and storage stability, and also tends to have poor charging characteristics. The reality is that a practically preferable charge transport material has not been found for producing electrophotographic photoreceptors.

3. Purpose of the Invention The purpose of the present invention is to have a photosensitive layer consisting of a combination of a carrier generation phase and a carrier transport layer, to exhibit high sensitivity, and to provide high sensitivity when repeatedly used in an electrophotographic process, etc. Another object of the present invention is to provide a photoreceptor in which a potential history state is maintained stably and a good visible image can always be formed.

Another object of the present invention is to provide a photoreceptor having a charge transport layer with improved film strength, uniformity, and stability by using a charge transport material with excellent compatibility with a polymeric binder. 04. Structure of the invention and its effects, that is, the present invention provides a photoreceptor having a photosensitive layer consisting of a carrier generation phase and a carrier transport phase, in which the carrier generation phase is a bisazo compound represented by the following general formula [■] The present invention relates to a photoreceptor, characterized in that the carrier transport phase contains a hydrazone compound represented by the following general formula [II].

General formula [I]: [However, in this general formula, Ar1 and Ar2: each substituted or unsubstituted carbocyclic aromatic ring group, or substituted or unsubstituted heterocyclic aromatic ring group, R1 and R2: Each of them is an electron-withdrawing group or a hydrogen atom (at least one of R1 and Rm is an electron-withdrawing group such as 10N, -CJ, etc.), NOx, etc., provided that R4 and R8 are each a hydrogen atom. , a substituted or unsubstituted alkyl group, R6 is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group> Y is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group, Sulfo group, substituted or unsubstituted carbamoyl group, or substituted or unsubstituted sulfamoyl group (however, when there are two or more groups, they may be different groups); 2 is a substituted or unsubstituted carbocyclic aromatic group; R3 is a hydrogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamoyl group, a carboxyl group, or an ester thereof; group, A is a substituted or unsubstituted aryl group, n is 1″l
or an integer of 2, m is an integer of θ to 4. ] General formula [■]: [In this general formula, R7 and R1: each a hydrogen atom or a halogen atom, R'' and R1@: each a substituted or unsubstituted aryl group, R3: a substituted or unsubstituted arylene group ] In the present invention, the above-mentioned "phase" includes not only a so-called layered structure but also a phased structure in which the constituent substances are in contact with each other.

According to the present invention, the bisazo compound represented by the general formula [■] is used as a CGM, and the bisazo compound represented by the general formula [■]
By using the hydrazone compound represented by CTM as a CTM and skillfully combining these, it has extremely high sensitivity compared to the conventional two-layer photosensitive layer, and even has high spectral sensitivity over the entire visible light region. A photoreceptor is obtained.

Further, the photoreceptor of the present invention has high charge retention and surface strength, has an extremely low residual potential, and therefore exhibits stable performance even after repeated use, and does not accumulate charge. In addition, during the formation of the carrier generation phase and the carrier transport phase, shrinkage of the film or crystal precipitation of the contained substances does not occur,
Therefore, problems of peeling and clouding do not occur.

The effects of the present invention can only be obtained by using a combination of specific substances having the above general formulas as the carrier-generating substance and the carrier-transporting substance, respectively. Even if a substance other than those used in the present invention is used as a carrier transport substance, for example, the above-mentioned excellent effects can be obtained by using a substance other than that used in the present invention, such as boIJ-N-vinylcarbazole, 2,4,7-dolinitro-9-fluorenone, or oxadiazole derivative. You can't get it. Conversely, the same applies when other substances are used as the carrier generating substance.

5. Real #! ■ Hereinafter, the present invention will be explained in more detail with reference to Examples.

First, the general compounds (I) and (n) used in the present invention will be specifically illustrated.

Among the bisazo compounds represented by the general formula CI], preferred are those represented by the following general formula [In].

General formula (Ia): CN A-N=N-Art-C=CH-&''-N=N-A [However, kl, & spirit and A are the same as those defined in general formula C1,) ] More preferable ones are especially A in the general formula [Ia]
This is a compound in which r1 and Ar2 are as follows.

Ar1, Ar? = represents a substituted or unsubstituted phenyl group; substituents include alkyl groups such as methyl group and ethyl group; alkoxy groups such as methoxy group and ethoxy group;
A compound selected from a chlorine atom, a bromine atom, etc., a hydroxyl group, and a cyano group.Specific examples of the bisazo compound represented by the general formula CI) include those having the following structural formula. Yes, but not limited to these.

(I-1) (I-3) (I-4) (I-5) (I-6) (I-7) (I-9) (I-10) (1-11) (1-12) (1-13) QC*H8 (I-14) H3 (I-15) (I-16) (1-17) (I-18) (I-, 19) (I-20) (I-21) (I-22) (I-23) (I-24) (I-25) (I-26) (I-27) (I-28) (I-29) (I-31) -32) (I -34) + CI'J ( (I -36) N :I -38) :I-39) (I-40) (1-41) (I-42) (I-43) (I-44) ( I-45) (I-46) (1-47) (I-48) (I-,19) (I-50) (I-51) (I-52) 0 (I-53) (I- 54) z (I-55) (I-56) + N02 (1-57) ' :I-58) (I-59) (I-60) (I-61) (I-62) (I-63 ) (I-64) (I-65) (I-66) (I-67) (I-68) (I-69) (I-70) (I-71) (1-72) (1-73 ) (I-74) (■ (I-76) (I-77) (1-78) (I-79) (I-80) Next, the specific properties of the hydrazone compound represented by the above general formula [■] As examples, examples include, but are not limited to, those having the following structural formula.

(II-1) (II-2) (II-3) (II-4) (II-6) (ns) (II-9) (II-10) (II-11) (II-12) (II-13) (II-14) Next, the present invention will be specifically explained with reference to the drawings.The photoreceptor of the present invention is constructed as shown in FIG. 1, for example. That is, a carrier generation layer 2 containing the above-described bisazo compound as a main component is formed on a conductive support 1, and a carrier transport layer 3 containing the above-mentioned hydrazone compound as a main component is formed on this carrier generation layer 2. The carrier generation layer 2 and the carrier transport layer 3 constitute a photosensitive layer 4 by laminating them.

Here, as the material of the conductive support 1, for example, a sheet of metal such as aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, steel, or brass can be used. , but not limited to these, for example, as shown in FIG.
The conductive support 1 can also be configured by providing a conductive layer IB thereon. In this case, the substrate IA is suitably flexible, such as paper or a plastic sheet, and has sufficient strength against stress such as bending and tension. The conductive layer IB can also be provided by laminating metal sheets or vacuum depositing gold, or by other methods.

The carrier generation layer 2 may be made of a bisazo compound alone, a bisazo compound added with an appropriate binder resin, or a substance having a high mobility for carriers of specific or non-specific polarity (i.e., a carrier transporting substance) added thereto. It is possible to form as many as K.

Specific forming methods include a method in which the bisazo compound is vacuum-deposited on the support, and a method in which the bisazo compound is dissolved or dispersed in a suitable solvent alone or together with a suitable binder resin, and then applied and dried. can be mentioned.

In this latter method, binder resins or carrier transport substances may be added, in which case
The ratio of carrier generating substance: binder resin: carrier transporting substance is 1: (θ~1oo): (o~50
0), particularly 1: (θ~10):(θ~50).

Examples of the solvent or dispersion medium used in the above method include n-butylamidi, diethylamine, ethylenediamine, isopropanolamine, monoethanolamine, triethanolamine, triethylenediamine, N,N-
Dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene,
Dichloroform, 1,2-dichloroethane, dichloromethane, tetrahydrone, dioxane, methanol, ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and others can be used.

Further, as the binder resin, for example, polyethylene,
Addition polymer resins and polyaddition resins such as polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, etc. , polycondensation type resins, as well as copolymer resins containing two or more of the shuttle units of these resins, such as -vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-p! (In addition to insulating resins such as water-maleic acid copolymer resins, poly-H
- Polymeric organic semiconductors such as vinyl carbazole can be mentioned. The ratio of this binder resin to the bisazo compound is 0 to 100% by weight, particularly 0 to 1% by weight.
It is in the range of 0% by weight.

An appropriate CTM may be added to the CGL2 as necessary.

Furthermore, this carrier generation layer may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use, and the like.

Examples of electron-accepting substances that can be used here include succinic anhydride, maleic anhydride, dibromaleic anhydride, heptatalic anhydride, tetrachlorophthalic anhydride,
Tetrabromo phthalic anhydride, 3-nitro hepthalic anhydride,
4-nitro-7tallic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene, 1, 3. 5-IJ nitrobenzene, varanitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, pullmanil, dichlorodicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, 2,7-cyclohexanone, 2,4.7-)linitrofluorenone, 2.4,5.7-tetodinido gastric fluorenone, 9-fluorenylidene [dicyanomethylenemalonodinitrile], polynitro-9-fluorenyritene [dicyanomethylenemalonodinitrile], picric acid,
0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrobenzoic acid, phthalic acid, mellitic acid, and other electron-affinity Large compounds may be mentioned. In addition, the addition ratio of the electron-accepting substance is
Weight ratio of carrier generating substance: electron accepting substance = 100
:0.01~200 preferably ioo: o, i~
It is 100.

The thickness of the CG L 2 formed as described above is preferably o, oos to 20/jm-1, particularly preferably 0.05 to 5 (1 m). Sensitivity cannot be obtained, and if it exceeds 20 pm, sufficient charge retention cannot be obtained.

In addition, the above-mentioned CTL3 is prepared by applying the above-mentioned hydrazone compound in the same way as the above-mentioned CGL2 (that is, by dissolving and dispersing it alone or together with the above-mentioned binder resin,
dry). And other CT
In this case, the blending ratio of the binder resin and the total carrier transport material is preferably 10 to 500 parts by weight per 100 parts by weight of the binder resin. When polycarbonate is used, it is preferable to use 20 to 200 parts by weight of the total carrier transport material per 100 parts by weight of polycarbonate because excellent electrophotographic properties can be obtained.

Additionally, the above-mentioned electron-accepting substance may be added to this carrier transport layer for the purpose of improving sensitivity and further reducing residual potential or fatigue during repeated use. When a similar electron-accepting substance is added to both the carrier generation layer and the carrier transport layer, the electron-accepting substances added to each layer may be the same or more or partially the same, or may be completely different in some cases. It doesn't matter if there is. Note that the electron-accepting substance may be added to either one of the carrier transport layers.

The addition ratio of the electron-accepting substance to the gear transport layer is the MM ratio of the total carrier-transporting substance:electron-accepting substance=100:θ,
01-100, preferably 100:0.1-5°.

The thickness of the carrier transport layer 3 formed in this way is 2
-100 μm, preferably 5-30 pm.

The present invention has been described above according to the specific structural example shown in FIG. 1 or FIG. This is sufficient, and the mechanical structure of the electrophotographic photoreceptor can be arbitrarily selected.

For example, as shown in FIG. 3, a suitable intermediate layer 5 is provided on a conductive support 1, a carrier generation layer 2 is formed thereon, and a VC:#Year transport layer 3 is formed thereon. Good too. This intermediate layer 5 has a function of preventing free carriers from being injected from the conductive support 1 into the photosensitive layer 4 when the photosensitive layer 4 is charged, and also has the function of preventing the photosensitive layer 4 from being injected into the photosensitive layer 4 integrally with the conductive support. It can be made to function as a contact N layer for adhering to. The material of the intermediate layer 5 includes metal oxides such as aluminum oxide and indium oxide;
Acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride A polymeric material such as -vinyl acetate-maleic anhydride copolymer resin can be used.

Further, as shown in Fig. M4, a carrier transport layer 3 is formed on the conductive support l with or without the intermediate layer 5, and a carrier generation layer 2 is formed thereon to form a photosensitive layer. 4 may be configured.

Further, FIG. 5 shows a layer formed by dispersing the above-mentioned carrier-generating substance (bisazo compound) in a carrier-transporting phase containing the above-mentioned hydrazone compound (i.e., a mixed layer of a carrier-generating substance phase and a carrier-transporting substance phase). An example in which a single-layer photosensitive layer (consisting of the following) is formed is shown below.

The present invention will now be described in more detail with reference to a specific example of IIfA.

Example 1 A vinyl chloride-vinyl acetate-maleic anhydride copolymer [Eslec M
Made of F-10J (manufactured by Tsukimizu Kagaku Kogyo Co., Ltd.) with a thickness of approximately 0.1
An intermediate layer of .mu.m was provided. Next, 1 already mentioned structural formula (I-
The bisazo compound shown in 55) was dispersed in a ball mill for 12 hours with 2 ft 1.2-dichloroethane 100-, the resulting dispersion was applied onto the intermediate layer using a doctor blade, and was sufficiently dried to a thickness of about 0. .3μm CG
L was formed.

On the other hand, the hydrazone compound 11.25f shown by the structural formula (It-2) described above and the polycarbonate resin "Panlite L-12504 (manufactured by Yondai Kasei Co., Ltd.) 15F were mixed at 1°2-
The resulting solution was applied onto the CGL using a doctor blade and dried at a temperature of 80°C for 1 hour to form a C, TL with a thickness of 12 μm, thereby forming a CGL with a thickness of 12 μm. An electrophotographic photoreceptor based on the method was manufactured.

This will be referred to as "Sample 1".

Examples 2 to 5 In the formation of CGL, except for using the bisazo compounds shown in the structural formulas (I-57), (I-5), (I-38) and (I-53), respectively. In exactly the same manner as in Example 1, four types of electrophotographic photoreceptors according to the present invention were manufactured. These will be referred to as "Sample 2,""Sample3,""Sample4," and "Sample 5," respectively.

Examples 6 to 7 The present invention was carried out in the same manner as in the example except that the compounds represented by the structural formulas (II-13) and (IT-7) described above were used as hydrazone compounds in the formation of CTL. A basic electrophotographic photoreceptor was manufactured. This is called “Sample 6” and “
"Sample 7".

Example 8 An intermediate layer was provided on a conductive support in the same manner as in Example 1, and a bisazo compound 2t represented by the structural formula (I-1) and a polycarbonate resin "Panlite L-1" were prepared.
250J 1 f and 1,2-dichloroethane 100
The resulting dispersion was applied onto the intermediate layer using a doctor blade, and thoroughly dried to form a CGL with a thickness of about 0.5 pm.

After forming this CGL, a CTL was formed in the same manner as in the formation of CTL in Actual Fiber Example 1, thereby producing an electrophotographic photoreceptor according to the present invention. This will be referred to as "Sample 8."

Comparative Example 1 Comparative electrophotography was performed in the same manner as in Example 1, except that a pyrazoline compound having the following structural formula was used in place of the hydrazone compound represented by general formula (n) in the formation of CTL in Example 1. A 71c photoreceptor was manufactured. The slippage is referred to as "Comparative Sample 1."

Comparative Example 2 In the formation of CTL in Example 1, a 4-ly diazole derivative having the following structural formula A was used instead of the human dicine compound represented by the general formula (U) #1. 1
A comparative electrophotographic photoreceptor was produced in the same manner as described above. This will be referred to as "comparative sample 2."

Structural formula A: For each of the electrophotographic photoreceptors obtained as described above (Samples 1 to 8 and Comparative Samples 1 and 2), an "electrometer SP 428 type" (manufactured by Kawaguchi Denki Seisakusho) was used. The electrophotographic properties were investigated using this method. In other words, the acceptance potential VA (V) when the surface of the photoreceptor is charged with a charging potential of -6 KV for 5 seconds, and the exposure required to attenuate the potential (initial potential) after 5 seconds of dark decay to A. The amount B y2 (lux·sec) was investigated. The results are in the table below.
The rules were as shown in 1.

Table-1 Also, Samples 1 to 6, Comparative Sample 1 and Comparative Sample 2
Each of the
RJ (attached to Konishi Roku Photo Industry fM5 for continuous copying, black paper potential vb (v) at exposure aperture value 1.0
Collect the blank potential Vw (V) using an "electrostatic voltmeter 144D-ID type" (Monroe Elec).
(manufactured by Nyx Inc.) T-T was measured immediately before development. The results were as shown in Table 2 below.

Note that the black paper potential here refers to the surface potential of the photoreceptor when the above-mentioned copying cycle is performed using a black paper with a reflection density of 1.3 as the original, and the white paper potential refers to the surface potential of the photoreceptor when a black paper with a reflection density of 1.3 is used as the original. Expresses the surface potential of the photoreceptor at the time (in the above table, Δvb
(v) and ΔVw (V) are the black paper potential Vb, respectively.
(V) and the white paper potential Vw (V), where ■ in the variation amount represents an increase, and O represents a decrease. ) As is clear from the above results, the electrophotographic photoreceptor according to the present invention not only has sufficient photosensitivity, but also maintains a stable potential history state even when subjected to repeated electrophotographic processes. , it is possible to stably form a large number of visible images of good quality.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIGS. 1, 2, 3, 4, and 5 are sectional views of five examples of electrophotographic photoreceptors. In addition, in the symbols shown in the drawings, ■・・・・・・・・・・・・・・・ Board 2...
......Carrier generation layer (CG L) 3...
・・・・・・・・・・・・Carrier transport layer (CT L
)4・・・・・・・・・・・・Photosensitive layer. Agent: Patent Attorney Hiroshi Aisaka (and 1 other person) No. 70

Claims (1)

[Scope of Claims] 1. A photoreceptor having a photosensitive layer consisting of a carrier generation phase and a carrier transport phase, wherein the carrier generation phase contains a bisazo compound represented by the following general formula CI), and the carrier transport phase A photoreceptor comprising a hydrazone compound represented by the following general formula [1[]. General formula [I]: [However, in this general formula, Ar1 and Ar+1: each substituted or unsubstituted carbocyclic aromatic ring group, or substituted or unsubstituted heterocyclic aromatic ring group, R1 and R2: each an electron-withdrawing group or a hydrogen atom (however, at least one of R1 and W is an electron-withdrawing group), -NH8O* R'<However, R4 and R'' are each a hydrogen atom, a substituted or unsubstituted alkyl group, R6 is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group> Y is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group, a sulfophyl group, a substituent group is an unsubstituted carbamoyl group or a substituted or unsubstituted sulfamoyl group (however, when m is 2 or more, mutually different groups may be used) 2 is a 16-substituted or unsubstituted carbocyclic aromatic ring or a group of atoms necessary to constitute a substituted or unsubstituted heteroaromatic ring, R3 is a hydrogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted carbamoyl group, a carboxyl group, or the ester group, A' is a substituted or unsubstituted aryl group, n is 1i
or an integer of 2, m is an integer of 0 to 4. )] General formula [■]: [In this general formula, R7 and R@: each a hydrogen atom or a halogen atom, R9 and nlO: each a substituted or unsubstituted aryl group, Ar'': a substituted or unsubstituted arylene group be. 〕