JPS60102633A - Photosensitive body - Google Patents

Abstract

PURPOSE:To provide a photosensitive body stable against heat and light, superior in characteristics, such as electrostatic charge retentivity, sensitivity, and residual potential, small in fatigue change in repeated uses, and high in durability by incorporating a carrier generating material made of a specified bisazo compd. and setting amine concn. in a photosensitive layer in a specified range. CONSTITUTION:A photosensitive layer 4 formed on a conductive substrate 1 consists of a laminate of a carrier generating layer 2 composed essentially of a bisazo compd. represented by general formula [ I ] (in which A is one of groups of formulae [II]-[V]), and amine in an amt. of <=1/20 of said compd., and a carrier transfer layer 3 composed essentially of a carrier transfer material. Said amine to be added to the carrier generating layer 2 in a small amt. includes primary amine, such as monoethanolamine, n-butylamine, and ethylenediamine, and secondary amines, such as diethanolamine and diethylamine, and tertiary amine, such as triethanolamine and triethylamine, and heterocyclic amine, such as pyridine and piperidine, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Industrial Application Field The present invention relates to a photoreceptor, such as an electrophotographic photoreceptor.

2. Prior Art Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive substance such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used as electrophotographic photoreceptors. However, these inorganic photoreceptors have poor sensitivity, thermal stability, moisture resistance,
The properties required for an electrophotographic photoreceptor, such as durability, are not necessarily satisfactory. For example, selenium crystallizes due to heat, fingerprints, etc.
Characteristics as an electrophotographic photoreceptor tend to deteriorate. Furthermore, when cadmium sulfide is used, there are problems in moisture resistance and durability, and when zinc oxide is used, there are problems in durability. Furthermore, selenium and cadmium sulfide have significant restrictions in terms of manufacturing and coffin handling.

In order to overcome the drawbacks of inorganic photoreceptors as described above,
In recent years, the use of various organic phototetraelectric substances as materials for photosensitive layers of electrophotographic photoreceptors has been actively developed and researched.

For example, in Japanese Patent Publication No. 50-10496, poly-N-
An organic photoreceptor having a photosensitive layer containing vinylcarbazole and 2.4.7-)nitro-9-fluorenone is described. However, this photoreceptor is not necessarily satisfactory in sensitivity and durability. In order to improve these drawbacks, attempts have been made to develop organic photoreceptors with high sensitivity and durability by assigning the carrier generation function and carrier transport function to different substances in the photosensitive layer. ing. In such so-called function-separated type electrophotographic photoreceptors, it is possible to select substances that exhibit each function from a wide range of materials, so it is relatively easy to produce electrophotographic photoreceptors with arbitrary characteristics. It is possible to do so.

Many substances have been proposed as carrier-generating substances that are effective for such functionally separated electrophotographic photoreceptors.

Examples of using inorganic substances include, for example, Japanese Patent Publication No. 43-16
As described in Japanese Patent No. 198, there is amorphous selenium. This is combined with an organic carrier transport material,
The carrier generation layer made of amorphous selenium has the same drawback as described above that it is crystallized by heat or the like and its properties deteriorate.

In addition, many electrophotographic photoreceptors using organic dyes or organic pigments as carrier-generating substances have been proposed. JP-A-55-22834, JP-A-54-79632, JP-A-56-11
This is already known from Publication No. 6040 and the like. However, electrophotographic photoreceptors using these bisazo compounds have poor sensitivity and
The electrophotographic process experienced by electrophotographic photoreceptors is not always satisfactory in terms of residual potential or stability during repeated use, and the selection range of substances to be used as carrier transport substances is limited. However, it does not fully satisfy the wide range of requirements. Moreover, although known bisazo compounds exhibit relatively good sensitivity in the short or medium wavelength range, they lack sensitivity in the long wavelength range, and for example, when a tungsten lamp is used as a light source, the long wavelength component is wasted. Moreover, long wavelength light such as a semiconductor laser cannot be used as a light source.
Therefore, the wavelength range that can be used tends to be limited, and cannot be used for a wide variety of purposes.

The method for manufacturing the above-mentioned functionally separated photoreceptor is as follows:
There is a method in which the carrier generation layer and the carrier transport layer are formed by coating them using separate coating liquids, a method in which the carrier generation layer is formed by vapor deposition, and the like. The carrier generation layer may or may not contain a resin, but in either case, a tube with improved sensitivity is desired.

JP-A-52-55643 discloses an example in which an amine is used as a solvent for the purpose of increasing the sensitivity of a photoreceptor. According to this, dye substances (azo dyes and squaric acid derivatives) for generating carriers that are soluble in organic 17-mine
is dissolved in an organic primary amine-containing solvent such as ethylenediamine, and this is applied onto a conductive substrate to form a carrier generation layer.

However, when the present inventor investigated the technique of forming a carrier generation layer using an amine as a solvent as described above, it was discovered that the following defects occur. The performance is determined, but in the method described above, the azo dye is dissolved and coated, so it is completely amorphous, and sufficient performance cannot be obtained.

In addition, since a large amount of dissolved amine is used, the absorption wavelength of the resulting carrier generation layer shifts to the shorter wavelength side.
This results in a significant decrease in photosensitivity, dark decay of the photoreceptor, and a significant decrease in acceptance potential during repeated use.

The inventor of the present invention believes that the above-mentioned problem arises because the above-mentioned known technology uses a large amount of amine to dissolve the carrier-generating substance, so the amount of amine contained in the carrier-generating layer is limited. It was determined that the amount of amine was too high, and that the amine concentration in the coating solution was too high.

3. Object of the invention The object of the present invention is to contain a specific carrier-generating substance, be stable against heat and light, have high carrier-generating efficiency, and have excellent photoconductivity even in a wide wavelength range. Moreover, by setting the amine concentration in the photosensitive layer within a specific range,
The seventh object of the present invention is to provide a photoreceptor that can eliminate all of the drawbacks of the prior art described above.

4. Structure of the invention and its effects, that is, the present invention comprises a photosensitive layer containing a bisazo compound represented by the following general formula [■] and an amine in an amount equal to or less than twice the number of moles of the carrier-generating substance. (However, in this general formula, A is Z: a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle). Atomic group, Y: hydrogen atom, hydroxyl group, carboxyl group or ester group thereof, sulfo group, substituted or unsubstituted carbamoyl group, or substituted or unsubstituted sulfamoyl group, nl: hydrogen atom, substituted or unsubstituted alkyl group , substituted or unsubstituted amine group, substituted or unsubstituted carbamoyl group, carboxyl group or its ester group, or cyan group, Ar: B-substituted or unsubstituted aryl group, R2: substituted or unsubstituted alkyl group, substituted or an unsubstituted aralkyl group, or a substituted or unsubstituted aryl group.) According to the present invention, as is clear from the description of the examples below, it is stable against heat and light, and charge retention,
It is possible to provide a photoreceptor that is excellent in characteristics such as sensitivity and residual potential, exhibits little fatigue change even when used repeatedly, and has high durability. In particular, in the present invention, the bisazo compound represented by the above general formula CI) has an excellent carrier generation ability, and this is combined with the carrier transport substance represented by the above general formula [ll] to form a functionally separated photosensitive layer. With this structure, a photoreceptor with even better characteristics can be obtained.

Among the bisazo compounds of the above general formula CI), carbazole group-containing bisazo compounds represented by the following general formula [■'] are particularly effective.

General formula [I]: (However, R10 and R11 are an alkyl group, an alkoxy group, or an aryl group, and R12, R13, R14, R15, R16, and R17 are
Hydrogen atoms,...rogen atoms, alkyl groups, alkoxy groups, amine groups, hydroxyl groups, and aryl groups. ) This bisazo compound of general formula [I'] is thought to have a carbazole group in the molecule that contributes to the sensitizing effect, giving it excellent sensitivity especially in the long wavelength range, and the carbamoyl group in the molecule contributing to the sensitizing effect. In combination with the base, it acts effectively as a coupler, exhibiting good sensitivity characteristics over a wide wavelength range, and exhibiting excellent characteristics as a photoreceptor for semiconductor lasers.

Furthermore, according to the present invention, it is extremely important that the photosensitive layer contains amine in a mole number equal to or less than double the amount of the carrier-generating substance (desirably, a trace amount), together with the bisazo compound described above. . That is, amines are generally said to be effective for improving sensitivity (Japanese Patent Laid-Open No. 52-55643).
However, if the amount is too large, amines often have a strong irritating odor, so using a large amount of amine may worsen the environmental conditions during application or take a long time to dry after application. Unfortunately, the surface remains sticky even after drying. However, the amine carrier is less than twice as high as the generating substance (
(preferably 10 times or less, especially 5 times or less), so that the charge generating substance is not substantially dissolved by the amine during coating formation of the carrier generation layer (that is, the amine does not act as a solvent); It can be in a dispersed state in the coating liquid. As a result, coating in a dispersed state is possible, the crystallinity of the coated layer is improved, and the absorption spectrum changes more sharply, resulting in improved photosensitivity. Moreover,
In general, the dark decay caused by using an azo compound as a carrier generating substance and the decrease in acceptance potential upon repeated use are effectively prevented by the above-mentioned amine content range. Furthermore, since the amount of amine is small, the drying time after application is shortened and the surface becomes non-sticky.
It is also advantageous in terms of environmental protection during application.

In addition, depending on the above amine content, it is possible to improve optical characteristics such as photosensitivity by adding amine;
This is noticeable when the carrier-generating substance has an electron-withdrawing group such as a cyano group, such as the above-mentioned bisazo compound.

In addition, with the above content of amine, the amine is effectively adsorbed to the acceptor site in the carrier generation layer, decreasing the acceptor concentration and increasing the electrical resistance of the carrier generation layer, thereby increasing the acceptance potential and darkening. It is thought that this can reduce the attenuation.

The amines added in small amounts to the carrier generation layer include primary amines such as monoethanolamine, n-butylamine, and ethylenediamine, secondary amines such as jetanolamine and diethylnamine, and tertiary amines such as triethanolamine and triethylamine. It may consist of heterocyclic compounds such as pyridine and piperidine.

In the photoreceptor of the present invention, it is desirable that the molecular weight of the amine is 150 or less and the basicity (K8) is 1012 or more, and the boiling point of the coating solvent for the carrier generation layer or the carrier transport layer in contact with the carrier generation layer is It is preferable to use amines with a very high boiling point.

Furthermore, it is desirable that the drying temperature of the carrier generation layer or carrier transport layer coating solution after coating is lower than the boiling point of the amine.

Further, in the present invention, it is preferable that the bisazo compound has an average particle size of 5 μm or less, preferably 2 μm or less, and more preferably 1 μm or less.

In other words, if the particle size is too large, dispersion in the layer will be poor, and some of the particles will protrude from the surface, resulting in poor surface smoothness. Toner particles tend to adhere to the toner, causing a toner filming phenomenon. As a result, charging characteristics, sensitivity, etc. deteriorate significantly. However, if the above grain size is too small, it tends to aggregate, which increases the resistance of the layer, increases crystal defects and reduces sensitivity and repeatability, or there is a limit to miniaturization, so the average grain It is desirable that the lower limit of the diameter is 0.01 μm.

Specific examples of the bisazo compound represented by the general formula (Ill) that are effective in the present invention include those represented by the following structural formula, but the bisazo compound to be used in the present invention is limited by this. It's not something you can do.

(I-1) (I-2') (I-3) (I-4) (I-5) (I-7) (I-8) (I-9) (I-10) (I-11 ) (I-14) (I-16) (I-17) (I-18) (I-19) (I-21) (I-22) I-23) 'I-24) (I-26) (I-27) t (I-29) (I-32) H3 34) Go to C (I-35) (I-36) (I-37) C3H60HC3H60I] 1 (I-38) (I-39) CH3C1(3 1 (I-40) (I-41) (I-42) (I-43) (I-44) The bisazo compound as described above, for example, the bisazo compound shown in (I-1) above, is 0i-j'2, which can be synthesized by the method shown in the following synthesis example,
A compound (2 ,7-sinitro9-
Dicyanomethylidenefluorene) was reduced with tin and hydrochloric acid to obtain 2°7-diami2-9-dicyanomethylidenefluorene dihydrochloride. Part 3.31r (
0.01 mol) was dispersed in 100 g of hydrochloric acid, the dispersion was cooled to a temperature of 5°C while stirring, and an aqueous solution of 1.4 v of sodium nitrite dissolved in 20 m of water was added dropwise to this. Ta. After the dropwise addition was completed, stirring was continued under cooling for an additional hour, and then filtration was performed. Ammonium hexafluorophosphate 102 was added to the obtained filtrate, and the resulting crystals were collected by filtration to obtain tetrazonium hexafluorophosphate. I got it. The crystals were dissolved in N,N-dimethylformamide 20O
tnl to obtain a dropwise solution for the next Campling reaction.

Next, 2-hydroxy-3-naphthoic acid anilide (naphthol AS) 5.27 F (0.02 mol) was added to N
, was dissolved in 200% of N-dimethylformamide, 5.52% of triethanolamine was added thereto, the solution was cooled to a temperature of 5°C, and while stirring vigorously, the above-described solution was added dropwise to it. added. After the dropwise addition was completed, the mixture was stirred for 1 hour under cooling, and further stirred for 2 hours at room temperature, and the resulting crystals were collected by filtration. The crystals were washed 92 times with 1 liter of N,N-dimethylformamide and 2 times with 11 liters of acetone, and then dried to obtain 6.70 r of a blue compound (yield: 83.0%).
I got it.

This blue compound was identified as the target compound ( The elemental analysis results (chemical formula is C3oH
3oN8o4. ) was as follows.

Element c HN Actual value (burning) 74,61 3.70 13.67 Theoretical value (chi) 74,43 3.74 13.89 Photoreceptor of the present invention prepared by a bisazo compound represented by the above general formula [■], For example, in order to constitute the photosensitive layer of an electrophotographic photoreceptor,
A layer in which the bisazo compound is dispersed in a binder may be provided on a conductive support. Alternatively, the bisazo compound may be used as a carrier-generating substance and combined with the carrier-transporting substance of general formula (II) having carrier-transporting ability to provide a so-called functionally separated photosensitive layer of a laminated type or a dispersed type. In the composition of the photosensitive layer, not only 1m but also 2m of the bisazo compound represented by the general formula [■] is used.
Use in combination of more than one species, other bisazo compounds,
It can also be used in combination with other carrier generating substances.

When the electrophotographic photoreceptor is of a functionally separated type, it is usually constructed as shown in FIGS. 1 to 6. The ones in Figures 1 and 3 are
A photosensitive layer 4 consisting of a laminate of a carrier generation layer 2 containing the above-mentioned bisazo compound and a trace amount of amine as a main component and a carrier transport layer 3 containing a carrier transport substance as a main component is provided on a conductive support 1. The configuration is as follows. 2 and 4 have a structure in which an intermediate layer 5 is provided between the conductive support 1 and the photosensitive layer 4 in the structure shown in FIGS. 1 and 3, respectively. In the photosensitive layer 4 in FIG. 5, a carrier-generating substance 7 (such as the bisazo compound described above) is dispersed in a layer 6 containing a carrier-transporting substance as a main component.
6 is a structure in which a photosensitive layer 4 similar to that shown in FIG. 5 is provided on a conductive support 1 via an intermediate layer 5. In the structure shown in FIG.

In the case of forming a photosensitive layer having a two-layer structure, the carrier generation layer 2 can be provided by the following method.

(a) A method of applying a solution prepared by dissolving the above-mentioned bisazo compound and amine (the number of moles equal to or less than the multiplication of the carrier-generating substance) in a suitable solvent, or a solution prepared by adding a binder to the solution and mixing and dissolving the same.

(b) Ball mill the bisazo compound and amine mentioned above,
A method in which fine particles are made into fine particles in a dispersion medium using a homomixer, etc., and a binder is added as necessary to mix and disperse the obtained dispersion, and then the resulting dispersion is applied.

When particles are dispersed under the action of ultrasound in these methods, uniform dispersion is possible.

As the solvent or dispersion medium used for forming the carrier generation layer, n-butylamine, diethylamine, ethylenediamine, ingropanolamine, triethanolamine, triethylenediamine1. , N,N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, inglobanol, ethinoacetate, butyl acetate, dimethyl sulfoxide, etc. can be mentioned.

When a binder is used to form a carrier generation layer or a carrier transport layer, any binder can be used, but in particular, an electrically insulating film-forming polymer that is hydrophobic and has a high dielectric constant. is preferred. Examples of such polymers include, but are not limited to, the following:

a) Polycarbonate b) Polyester C) Methacrylic resin d) Acrylic resin e) Polyvinyl chloride f) Polyvinylidene chloride g) Polystyrene h) Polyvinyl acetate i) Styrene-butadiene copolymer j) Vinylidene chloride-acrylonitrile copolymer k) Vinyl chloride-vinyl acetate copolymer t) Vinyl chloride-vinyl acetate-maleic anhydride copolymer m) Silicone resin n) Silicone-alkyd resin 0) Phenol-formaldehyde resin p) Styrene-
Alkyd resin q) Poly-N-vinylcarbazole r) Polyvinyl butyral These binders can be used alone or in a mixture of two or more. In addition, the ratio of the carrier-generating substance to the binder is 0 to 100% by weight (particularly 0% to 100% by weight).
~10% by weight), and the carrier transport material is preferably 10 to 500 parts by weight.

Carrier generation formed in this way)? The thickness of lJ2 is preferably 0.01 to 208 m, more preferably 0.05 to 5 m. The thickness of the carrier transport layer is 2 to 100 μm, preferably 5 to 30 μm.

The carrier-generating substance used in the present invention is a long-wavelength light (~8
00 nm), it is thought that the particle size particularly affects the charge-responsive ability. The reason for this is thought to be that the surface charge is neutralized by the generation of thermally excited carriers in the carrier-generating substance, and it is thought that the larger the particle size, the greater this neutralization effect. Therefore, it is considered that high resistance and high sensitivity can only be achieved by reducing the particle size of the carrier-generating substance.

In addition to using the above-mentioned coating solution, as a method for incorporating a trace amount of amine into the carrier generation layer, it is also possible to incorporate a trace amount (i.e., with respect to the azo pigment of the charge generation layer) into the coating solution during coating formation of the charge transport layer. The added mole or less, preferably 10
It is also possible to adopt a method in which hairmin is added in an amount of amine (less than 5 moles, more preferably less than 5 moles) and diffused from the coating solution for the carrier transport layer into the lower carrier generation layer (when the coating solution dries). be. The amount of amine thus diffused into the carrier generation layer can be controlled to be equal to or less than the added mole of the azo pigment, as described above.

Another method is to leave the carrier generation layer in an amine solvent atmosphere for a predetermined period of time after forming the carrier generation layer and before applying the carrier transport layer, thereby allowing the amine to adhere to the surface of the carrier generation layer. , and can be further diffused into the carrier generation layer. With this method as well, it is possible to control the concentration of amine diffused into the carrier generation layer by controlling the concentration of amine in the atmosphere, and to set the amine concentration within the above-mentioned content range.

Further, the 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, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride,
-Nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, nato-2-cyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene,
1,3,5-trinitro II-Cyzene, varanitrobenzonitrile, vicryl chloride, quinone chlorimide, chloranil, chloranil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 2,7-sinitrofluorenone, 21417-11
=) Rofluorenone, 2,4,5.7-titranitrofluorenone, 9-fluorenyritene [dicyanomethylenemalonodinitrile], polynitro-9-fluorenyritene [dicyanomethylenemalonodinitrile], picric acid, o-nitro Benzoic acid, p-nitrobenzoic acid, 3,5
Examples include -dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity. The addition ratio of the electron-accepting substance is carrier-generating substance: electron-accepting substance = 1 by weight.
00:0.01-200 preferably 100:0
．． 1 to 100.

The support 1 on which the photosensitive layer is to be provided is a metal plate, a metal drum, or a conductive thin layer made of a conductive polymer, a conductive compound such as indium oxide, or a metal such as aluminum, palladium, or gold. A material that is provided on a substrate such as paper or a plastic film by means such as , vapor deposition, or 2-lamination is used. As the intermediate layer which functions as an adhesive layer or a barrier layer, materials such as the above-described high molecular weight polymers as binders, organic polymer substances such as polyvinyl alcohol, ethyl cellulose, and carboxymethyl cellulose, or aluminum oxide are used. It will be done.

5. Examples Hereinafter, the present invention will be explained in more detail with reference to specific examples and comparative examples.

A conductive support consisting of a polyester film laminated with aluminum foil.'' Second, a vinyl chloride-vinyl acetate-maleic anhydride copolymer [ESRESOC MF-10J (
An intermediate layer having a thickness of 0.05 μm was formed using the following materials: Next, each carrier generating substance shown in FIG. 7, each amine, and a binder if necessary were added to 100 g of 1,2-dichloroethane and dispersed in a ball mill for 12 hours to obtain a dispersion liquid, which was then placed on the intermediate layer. A carrier generation layer was formed by coating and drying so that the film thickness after drying was 0.3 μm. Furthermore, each carrier transport substance and binder (polycarbonate resin "Panlite L-12" shown in FIG.
50J) 15f and 1,2-dichloroethane 100-
Each electrophotographic photoreceptor was manufactured by applying and drying a solution in which a carrier transport layer was formed so as to have a dry film thickness of 15 μm.

Thus obtained electrophotographic photoreceptor electrostatic paper tester rSP
-428 type (newly manufactured by Kawaguchi Electric), and the following characteristic tests were conducted. That is, a voltage of 16 KV is applied to the charger to charge the photosensitive layer by corona discharge for 5 seconds, and then the potential at this time is set as VI. )
Then, with the illuminance on the surface of the photosensitive layer being 35 tux, light from a tungsten lamp is irradiated to obtain the exposure amount required to attenuate the surface potential of the photosensitive layer by 1/2, that is, the half-reduction exposure amount E1/2. Ta. In addition, the acceptance potential VA at the time of charging by the corona discharge was measured at the initial stage and after 10,000 copies. In addition, the dark decay rate (VA
-VI ) /VI . Furthermore, the sensitivity of semiconductor laser (780 nm) was also shown (◎ mark is extremely good, ○ mark is good, △ is slightly poor,
An X mark indicates a defect, and a - mark indicates that the experiment was not performed. )
. The results are summarized in Figure 7. However, the carrier-generating substance is indicated by the number of the structural formula exemplified above.

The results show that, based on the present invention, the electrophotographic properties are significantly improved by using the above bisazo compound as a carrier generating substance and by controlling the amount of added amine to less than the added molar amount.

In particular, as shown in FIG. 8, if the data in FIG. 7 are taken into account, it will be understood that it is extremely important to keep the amount of amine added to less than the added mole (particularly less than 5 mole).

FIG. 9 shows a sensitivity curve a when a photoreceptor is constructed as in Example A1 using the bisazo compound according to the present invention (Example A1 in FIG. 7) as a carrier generating substance. However, it can be seen that the photoreceptor according to the present invention exhibits excellent sensitivity even in a wide wavelength range, particularly in a long wavelength range such as a semiconductor laser range.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIGS. 1, 2, 3, 4, 5, and 6 are cross sections of a portion of each side of an electrophotographic photoreceptor. Figure 7 is a graph showing a comparison of changes in characteristics due to the composition of each electrophotographic photoreceptor; Figure 8 is a graph showing changes in characteristics due to the addition of amine (1t); Figure 9 is a graph showing photosensitivity due to carrier-generating substances. This is a graph showing. In addition, in the reference numerals shown in the drawings, 2------Carrier generation layer 3---Carrier transport layer 4---1 Photosensitive layer 6---Carrier generation substance and carrier transport substance Mixed layer 7 with carrier-generating substance. Agent Patent Attorney Hiroshi Aisaka (1 person) No. 1, No. 20, Office 30, JP-A-Sho GO-102633 (14) @ Figure 4, Figure 50, 6th Floor

Claims (1)

[Claims] 1. A bisazo compound represented by the following general formula (I);
A photoreceptor characterized in that a photoreceptor layer contains an amine in a mole number equal to or less than the multiplication factor of a carrier-generating substance. General formula [I] Group, Y: hydrogen atom, hydroxyl group, carboxyl group or ester group thereof, sulfo group, substituted or unsubstituted carbamoyl group, or substituted or unsubstituted sulfamoyl group, R1: hydrogen atom, substituted or unsubstituted alkyl group, Substituted or unsubstituted amine group, substituted or unsubstituted carbamoyl group, carboxyl group or its ester group, or cyan group, Ar: substituted or unsubstituted aryl group, T?2: substituted or unsubstituted alkyl group, substituted (or represents an unsubstituted aralkyl group, or a substituted or unsubstituted aryl group)