JPS60212764A - Photosensitive body - Google Patents

Abstract

PURPOSE:To form a photosensitive body stable against heat and light, superior in carrier generating ability as well as carrier transfer ability by incorporating a trisazo compd. represented by formula I in a carrier generating phase and a hydrazone compd. represented by formula II in a carrier transfer phase. CONSTITUTION:The trisazo compd. having an asymmetric structure and represented by formula I can serve as the effective component (CGM). A hydrazone compd. represented by formula II is used as a CTM in combination with said trisazo compd. as the CGM. The hydrazone compd. is good in transfer performance of photocarriers, especially, positive holes, and when a conductive substrate-a carrier generating layer-a carrier transfer layer are laminated in this order to form a photosensitive body, and its surface is especially negatively charged and exposed, positive holes generated in the carrier generating layer are injected into the carrier transfer layer, and effectively transferred to the surface. An electrostatic charge image good in contrast with the unexposed parts can be formed by selective neutralization of the surface charge.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Industrial Field of Application 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 phase.

24 Prior Art Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, cadmium sulfide, etc. as a main component have been widely used as photoreceptors. However, these are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. For example, when selenium crystallizes, its properties as a photoreceptor deteriorate, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., and its performance as a photoreceptor deteriorates. Furthermore, cadmium sulfide has problems with moisture resistance and durability, and zinc oxide has problems with durability, etc.

In order to overcome these drawbacks of inorganic photoreceptors, research and development have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components. For example, in JP-A-50-10496, poly-N-
Vinyl carbazole! :2,4゜7-Dori Nitro 9
- Organophotoreceptors are described which have a photosensitive layer containing fluorenone. 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 higher performance by assigning the carrier generation function and the carrier transport function to different substances.

Many studies have been conducted on such so-called functionally separated electrophotographic photoreceptors because each material can be selected from a wide range and a photoreceptor with arbitrary performance can be produced relatively easily. Ta.

In such a functionally separated electrophotographic photoreceptor, its carrier generating substance (hereinafter sometimes referred to as CGM)
Many compounds have been proposed as Examples of using inorganic compounds as CGM include
The amorphous selenium described in Publication No. 3-16198 is used in combination with an organic photoconductive compound, but the carrier generation layer made of amorphous selenium is crystallized by heat and loses its properties as a photoreceptor. The disadvantage of deterioration has not been resolved.

Furthermore, many electrophotographic photoreceptors using organic dyes or organic pigments as CGM have been proposed. For example, an electrophotographic photoreceptor containing a bisazo compound or a trisazo compound in a photosensitive layer is already known in JP-A-54-12742 and JP-A-53-95033.

However, these bisazo compounds or trisazo compounds do not sufficiently satisfy the wide demands of electrophotographic processes such as sensitivity and residual potential.

Furthermore, in recent years, lasers and He-
Gas lasers such as Ne lasers and semiconductor lasers are beginning to be used. These lasers are characterized by being capable of 0N10FF in time series, and are particularly promising as a light source for output printers such as copiers and converters having image processing functions, including intelligent copiers. Among these, semiconductor lasers are attracting attention because their properties do not require electrical signal/optical signal conversion elements such as acousto-optic elements, and because they can be made smaller and lighter. However, this semiconductor laser has a low output power compared to a gas laser, and also has a long oscillation wavelength (approximately 780 nm or more).

Since the spectral sensitivity of conventional photoreceptors is too close to the short wavelength side, it is impossible to use them as is as a photoreceptor using a semiconductor laser as a light source.

In recent years, electrophotographic photoreceptors using certain trisazo compounds have been proposed (JP-A-57-116345, JP-A-57-182748). However, even these proposed trisazo compounds are not satisfactory in terms of electrophotographic properties in the long wavelength region.

The above-mentioned functionally separated photoreceptor has a wide selection range of materials that can be used to form the photosensitive layer, and it is also possible to independently select materials or material systems that optimally perform each function. Electrons with excellent characteristics required in the electrophotographic process, such as high surface potential when charged, high charge retention capacity, high photosensitivity, and high stability even after repeated use. It becomes possible to obtain a photographic photoreceptor.

Conventionally, as such a photosensitive layer, the following ones are known, for example.

(1) Laminated carrier generation layer made of amorphous selenium or cadmium sulfide and carrier transport layer made of poly-N-vinylcarbazole (2) Carrier generation layer made of amorphous selenium or cadmium sulfide And, 2.
4. 7-) Laminated with a carrier transport layer containing dinitro-9-fluorenone.

(3) Laminated carrier generation layer composed of a perylene derivative and carrier transport layer containing an oxadiazole derivative (see US Pat. No. 3,871,882)0 (4) Chlordiane blue or methylscarillium A layer in which a carrier generation layer consisting of
(See Publication No. 90827).

(5) A layer in which a carrier generation layer composed of amorphous selenium or its alloy and a carrier transport layer containing a polyarylalkane aromatic amino compound are laminated (Patent application No. 52
-147251 specification).

(6) A layer in which a carrier generation layer containing a perylene derivative and a carrier transport layer containing a polyarylalkane aromatic amine compound are laminated (Japanese Patent Application No. 53-199
No. 07 Specification).

Although many books are known about this type of photosensitive layer, most of the conventional electrophotographic photoreceptors having such a photosensitive layer have problems with the photosensitive layer when subjected to repeated electrophotographic processes. It has the disadvantage of severe electrical fatigue and a very short service life. That is, even though it is necessary to eliminate the charge in the photosensitive layer when one electrophotographic process is completed and the photosensitive layer is used for the next electrophotographic process,
In this type of photosensitive layer, the discharge speed at the final stage of discharge is extremely low, so even if static electricity is removed by exposure to a fire scene, for example, it is impossible to completely remove the static electricity, and a very high residual potential remains, which may lead to damage. This residual potential increases cumulatively each time the electrophotographic process is repeated.
Eventually, after a small number of continuous copies, the residual potential exceeds its permissible limit and the electrophotographic photoreceptor becomes unusable.

Although it is possible to restore some types of photoreceptors to a usable state, it is difficult to do so by leaving the photoreceptor in a dormant state for a long period of time, or by subjecting it to appropriate heat treatment. Moreover, it is not possible to restore the residual potential to a sufficiently lowered state, and therefore, the number of consecutive copies that can be made before the next unusable state is reached is greatly reduced.

In addition to the above, among conventional photoreceptors, those containing a polyarylalkane aromatic amino compound in the carrier transport layer have a large deterioration of the photosensitive layer due to light, especially ultraviolet light. It has the disadvantage that it can be kept low.

Moreover, in known photoreceptors, sufficient consideration is not given to the appropriate selection of CTMs and their combinations. Therefore, the reality is that it has not been successful in obtaining desired electrophotographic characteristics with good reproducibility.

3. OBJECT OF THE INVENTION An object of the present invention is to provide a photoreceptor that is stable against heat and light, has excellent carrier generation ability, and has excellent charge transport ability.

Another object of the present invention is to provide a photoreceptor with high sensitivity in a long wavelength region, low residual potential, and excellent durability whose characteristics do not change even after repeated use.

Still another object of the present invention is to provide a photoreceptor having sufficient practical sensitivity even to long wavelength light sources such as semiconductor lasers. The body is a photoreceptor having a photosensitive layer consisting of a carrier generation phase and a carrier transport layer, in which a trisazo compound represented by the following general formula CI) is contained in the carrier generation phase, and is represented by the following general formula [■] The carrier transport layer is characterized in that a hydrazone compound is contained in the carrier transport layer.

General formula [I]: (However, in this general formula, A represents a substituted or unsubstituted phenyl group or a naphthyl group, and Ar1 and Ar1 are not the same group, and each is a substituted or unsubstituted carbocyclic group. (Represents an aromatic group.) General formula [■]: R'' (However, R' is a substituted or unsubstituted naphthyl group; R8 is a substituted or unsubstituted alkyl group, (for example, a methyl group,
ethyl group, propyl group, butyl group, hexyl group), aralkyl group (e.g. benzyl group, phenethyl group, naphthylmethyl group) or aryl group (e.g. phenyl group, naphthyl group); R'' is a hydrogen atom, an alkyl group (same as above) or an alkoxy group (e.g. methoxy group, ethoxy group, butoxy group); R6 and R1 are substituted or unsubstituted alkyl groups (
(same as above), aralkyl group (same as above) or aryl group (same as above)
Indicates mutually the same or different groups consisting of. In the case of the above-mentioned substituted groups, the substituent is, for example, a methyl group,
Alkyl groups such as ethyl, propyl and butyl groups; alkoxy groups such as methoxy, ethoxy, propoxy and butoxy; halogen atoms such as chlorine, bromine and iodine; dimethylamino, diethylamino and dialkyl There are dialkylamino groups such as amino groups and dibutylamino groups. ) Here, 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.

In the above general formula CI), A represents a substituted or unsubstituted phenyl group or a 7-tyl group, and examples of substituents include an alkyl group, an alkoxy group, a halogen atom, a nitro group, a cyano group, an acyl group, and an acylamino group. , amine group, etc.

Further, Ar1 and 8 are not the same group and represent a substituted or unsubstituted carbocyclic aromatic group, but preferably Ar is a substituted or unsubstituted naphthylene group, Ar-
represents a substituted or unsubstituted phenylene group, and examples of substituents include an alkyl group, an alkoxy group, a halogen atom,
Examples include a nitro group, a cyano group, an acyl group, an acylamino group, an amino group, a sulfamoyl group, and a carbamoyl group.

As a result of intensive research to achieve the above object, the present inventor discovered that a trisazo compound having an asymmetric structure represented by the above general formula [■] is an active ingredient of a photoreceptor (i.e., CG
They discovered that it could work as M). That is, the use of the trisazo compound represented by the general formula CI) as the photoconductive material constituting the photosensitive layer of the photoreceptor has remarkable charge retention ability, especially in the long wavelength region.
It is possible to provide an excellent photoreceptor that has improved characteristics such as sensitivity and residual potential, has little fatigue deterioration even when used repeatedly, and has sufficient sensitivity especially in a long wavelength region of 7801 m or more. In particular, the characteristics in this long wavelength range are similar to those of compounds with a known trisazo structure (
JP-A-57-116345, JP-A-57-182
748) and symmetrical trisazo compounds (described in JP-A-58-76841).

Moreover, according to the present invention, the above general formula C as CGM
The hydrazone compound of the above general formula [■] is used as cTM in combination with the trisazo compound of I). When a photoreceptor is constructed by laminating a carrier-generating layer and a carrier-transporting layer in this order, when the surface of the photoreceptor is negatively charged and exposed, holes generated in the carrier-generating layer are injected into the carrier-transporting layer. The electrostatic charges are then efficiently transported to the surface, and by selectively neutralizing the surface charges, it is possible to form an electrostatic charge image with good contrast with the unexposed areas.

In addition, in the present invention, together with the above hydrazone compound,
It is desirable to use a carbazole compound represented by the following general formula (III) in combination.

General formula [■]: Same or different groups consisting of a substituted or unsubstituted alkyl group, alkoxy group, aryloxy group, aryl group, amino group or hydroxyl group: Rs and R9 are substituted or unsubstituted alkyl groups or substituted or mutually identical or different groups consisting of unsubstituted aryl groups; A
rs represents a substituted or unsubstituted divalent carbocyclic aromatic ring, an oxygen atom or a sulfur atom-containing heterocyclic aromatic ring.

Here, the above-mentioned alkyl group, alkoxy group, aryl group, etc., and further substituents may be the same as those described above. ) That is, by incorporating the carbazole compound together with the hydrazone compound in the carrier transport phase, the amount of change in residual potential during repeated use can be greatly reduced. This is because carbazole compounds also generate photocarriers when irradiated with light, and these photocarriers recombine trapped holes, or because carbazole compounds preferentially absorb harmful ultraviolet light, etc. Conceivable.

In the present invention, if an electron-accepting substance or a Lewis acid, which will be described later, is added to at least one of the CTL (charge transport layer) and CGL (charge generation layer), a charge transfer complex is formed, so that the sensitizing effect can be enhanced. can be improved.

Next, CGM and CTM of the above general formula used in the present invention
I will explain in detail.

Among the trisazo compounds useful in the present invention represented by the general formula CI), particularly preferred are the following general formula [■']
It is indicated by.

General formula CI'): (However, in this general formula, R3 and R4 are hydrogen atoms, alkyl groups, alkoxy groups, halogen N atoms, nitro groups, amino7
group, acyl group, cyano group, acylamino group, carbamoyl group or sulfamoyl group. ) Specific examples of trisazo compounds useful in the present invention represented by the above general formulas [■] and [■'] are listed below. The substituents in Table 1 below represent the substituents of the respective corresponding parts of the following general formula CI).

General formula [I]: Table 1 The above trisazo compounds can be synthesized by known methods.

For example, in the synthesis of Exemplary Compound I-), 1-amino-4-p-aminophenyl azonaphthalene 5.25
f was dissolved in concentrated sulfuric acid. To this, pre-prepared nitrosyl sulfuric acid (concentrated sulfuric acid 15+nt) was added.

Sodium nitrite r)m3. OQ was added dropwise at -5°C to -10°C. After the dropwise addition, the mixture was stirred at the same temperature for 30 minutes and poured into 600 ml of ice water containing 2 (l) of ammonium hexafluorophosphate. The precipitated crystals were quickly collected by filtration.

This was dissolved in N,N-dimethylformamide 100- cooled to -15°C and used as a dropwise solution for the next coupling reaction.

2-Hydroxy-3-(4-methoxy-2-methylphenylcarbamoyl)-benzoi]carbazole (Naphthol ASSR, manufactured by Hoechst) 15. (1 and triethanolamine 10? were dissolved in 300-〇N,N-dimethylformamide, and the above-mentioned dropwise solution was gradually added thereto while cooling on ice at OoC. After the completion of the dropwise addition, the solution was kept at the same temperature for another 2 hours. After stirring at room temperature, the resulting crystals were collected by filtration.The crystals were diluted with 20011t of N,N-dimethylformamide twice and 11g of acetone twice.
After washing twice and drying, the exemplified compound (yield: 1.40?, 6.5%) was obtained.

This compound was confirmed by elemental analysis.

Elemental analysis results (chemical formula is CuHaN+.0.): Element
CHN Calculated value (a) 73.60 4.49 13.00 Actual value) 73.49 4゜62 13.055 The asymmetric trisazo compound of the present invention has excellent photoconductivity, and can be used for electrophotographic sensitization. In the case of manufacturing a photosensitive layer, a photosensitive layer in which the trisazo compound of the present invention is dispersed in a binder resin is provided on a conductive support. Another method is to use the trisazo compound of the present invention as a carrier-generating substance that takes advantage of its particularly excellent carrier-generating ability among its photoconductivity properties, and to use it together with a carrier-transporting substance that can effectively act in combination with this. It is also possible to use a so-called functionally separated type electrophotographic photoreceptor, such as a stacked type, a laminated type, or a dispersed type. Further, the trisazo compound used in the present invention has the above general formula [I]
Single or two trisazo compounds represented by
It can be used in combination of more than one species, or in combination with other disazo or trisazo compounds.

Next, examples of the hydrazone compound of the above general formula [1] used as the CTM in the present invention include, for example, those having the following structural formula, but are not limited thereto.

(II-1) (II-4) (n-7) (n-s) (n-9) (n-io) (n-11) (n-12) (n-13) (II-15) (n-16) (If-17) (n-18) (I[-20) The hydrazone compound represented by the general formula [I[] has the following general formula: %Formula% (However, R", R" is the same as described above) and an aldehyde represented by the general formula: (wherein R'', R', and R' are the same as described above).

Specific examples of the carbazole compound represented by the general formula [■] are listed below.

(m-i) (m-2) C-Hs CsH* (m-3) (Ill-5) (m-6) Hs (III-11). □s CL CHs CHj (m-13) (m-15) (m-17) The mechanical structure of the photoreceptor, for example, an electrophotographic photoreceptor, according to the present invention can take various forms.

Usually, the configuration is as shown in FIGS. 1 to 6. 1 and 3, a carrier generation layer (CGL) 2 containing the above-mentioned trisazo compound as a main component and a carrier transport layer (CTL) containing the above-mentioned hydrazone compound as a main component are formed on a conductive support 1. ) 3 is provided. As shown in FIGS. 2 and 4, one photosensitive layer 4 may be provided via an intermediate layer 5 provided on a conductive support. When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having excellent electrophotographic properties can be obtained.
Further, in the present invention, as shown in FIGS. 5 and 6, the carrier-generating substance (the above-mentioned trisazo compound) particles 7 are contained in the layer 6 mainly composed of the carrier-transporting substance (the above-mentioned hydrazone compound). A single-layer type photosensitive layer 4 made of dispersed particles may be provided directly on the conductive support 1 or via an intermediate layer 5.

In the present invention, a CGM whose main component is the above-mentioned asymmetric trisazo compound is used, but CGMs that can be used in combination with this include organic dyes as shown in the following representative examples. Good too.

(1) Azo dyes such as monoazo dyes, polyazo dyes, metal complex azo dyes, birazolonazo dyes, stilbene azo dyes, and thiazole azo dyes (2) Perylene dyes such as perylenic anhydride and perylenic acid imide (3) Anthraquinone derivatives , anthantrone derivatives, dibenzpyrenequinone derivatives, vilantrone derivatives,
Anthraquinone to polycyclic quinone dyes such as violanthrone derivatives and inviolanthrone derivatives (4) Indigoid dyes such as indigo derivatives and thioindigo derivatives (5) Heptalocyanine dyes such as metal phthalocyanine and metal-free phthalocyanine (6) Diphenylmethane Carbonium dyes such as triphenylmethane dyes, quinanthene dyes and acridine dyes (7) Quinoneimine dyes such as azine dyes, oxazine dyes and thiazine dyes (8) Methine dyes such as cyanine dyes and azomethine dyes (9) Quinoline A nitro dye ao a nitroso dye α2 a benzoquinone and naphthoquinone dye H a naphthalimide dye I a perinone dye α9 such as a bisbenzimidazole derivative a quinacridone dye In addition, as a CTM, those made of the above-mentioned hydrazone compounds can be used. In addition, in combination with this, electron-accepting substances that easily transport electrons such as trinitrofluorenone or tetranitrofluorenone, polymers having a heterocyclic compound in the side chain such as poly-N-vinylcarbazole, Triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives, polyarylalkane derivatives, phenylenediamine derivatives,
Examples include electron-donating substances that easily transport holes, such as hydrazone derivatives, amine-substituted chalcone derivatives, triarylamine derivatives, carbazole derivatives, and stilbene derivatives.

Carrier generation layer 2 constituting the above-mentioned two-layer photosensitive layer 4
can be formed directly on the conductive support 1 or the carrier transport layer 3 (or on an optional intermediate layer such as an adhesive layer or a barrier layer), for example, by the following method.

M-1)) A method of coating a solution obtained by dissolving a lisazo compound in a suitable solvent, or by adding a binder resin as necessary and mixing and dissolving the solution.

M-2)) A method in which a lisazo compound is made into fine particles in a dispersion medium using a ball mill, a homomixer, etc., a binder resin is added as needed, and a mixed and dispersed dispersion is applied.

The solvent tt dispersion medium used for forming the carrier generation layer includes n-butylamine, diethylamine, ethylenediamine, impropaturamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, and cyclohexanone. , bene/yne, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol,
Examples include isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and the like.

When using a binder resin in the carrier generation layer or carrier transport layer, any binder resin can be used, but
It is preferable to use a film-forming polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating. Examples of such high molecular weight polymers include, but are not limited to, the following.

P-1) Polycarbonate P-2) Polyester P-3) Methacrylic resin P-4) Acrylic resin P-5) Polyvinyl chloride P-6) Polyvinylidene chloride P-7) Polystyrene P-8) Polyvinyl acetate P-9 ) Styrene-butadiene copolymer p-1o) Vinylidene chloride-acrylonitrile copolymer P-11) Vinyl chloride-vinyl acetate copolymer P-12)
Vinyl chloride-vinyl acetate-maleic anhydride copolymer P-13) Silicone resin P-14) Silicone-alkyd resin P-15) Phenol-formaldehyde resin P-16
) Styrene-alkyd resin P-17) Poly-N-vinylcarbazole P-18) Polyvinyl butyral These binder resins can be used alone or as a mixture of two or more types.

The thickness of the carrier generation layer 2 formed in this way is
It is preferably 0.01 pm to 20 pm, more preferably 0.05 pm to 5 pm. Further, when the carrier generation layer or the photosensitive layer is a dispersed type, the particle size of the trisazo compound is preferably 5 μm or less, more preferably 1 μm or less.

Further, the ratio of the binder resin to the trisazo compound (CGM) is 0 to 100% by weight, particularly 0 to 10% by weight.
is within the range of

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

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

Examples of electron-accepting substances that can be used here include conozoic anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride,
Buto-2-bromo-7thalic anhydride, 3-nitro-phthalic anhydride,
4-nitro-7ph acid anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3.5-)IJ nitrobenzene, paranitrobenzonitrile , vicryl chloride, quinone chlorimide, chloranil, flumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone,
2,7-sinitrofluorenone, 2,4.7-)linitrofluorenone, 2゜4.5.7-titranitrofluorenone, 9-fluorenyritene [dicyanomethylenemalonodinitrile], polynitro-9-fluorenyrite:y
-C dicyanomethylenemalonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3, s-
Examples include dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, heptatalic acid, mellitic acid, and other compounds with high electron affinity.

In addition, the addition ratio of the electron-accepting substance is CGM:
Electron-accepting substance = 100: 0.01-200. Preferably it is 100:0.1-100.

In addition, the CTL3 contains the carbazolized metal as described above,
It can be formed in the same manner as CGL2 described above (that is, by coating alone or by dissolving and dispersing it together with the binder resin described above and drying). And other C
It may also contain TM.

In this case, the blending ratio of the 4 binder resins and the total CTM is 10 to 5 parts by weight of the total CTM per 100 parts by weight of the binder resin.
When polycarbonate is used as the binder resin, it is preferable to use 20 to 200 parts by weight of total CTM per 100 parts by weight since excellent electrophotographic properties can be obtained.

Furthermore, the above-mentioned electron-accepting substance can be added to the CTL for the purpose of improving sensitivity and further reducing residual potential or fatigue during repeated use. This electron-accepting substance is C
When added to both shoulders of GL and CTM, the electron-accepting substances added to each layer may be completely or partially the same, or may be completely different depending on the case. Note that the electron-accepting substance may be added to either CGL or CTL.

The addition ratio of electron-accepting substances to CTL is the total CT in terms of weight ratio.
M: Electron accepting substance = 100: 0.01 to 100
, preferably Zoo: 0.1-50.

The thickness of CTL3 formed in this way is 2 to 100
μIn, preferably 5 to 30 μm.

The conductive support 1 may be a metal plate containing an alloy, a metal drum, a conductive polymer, a conductive compound such as indium oxide, or a thin layer of a metal such as aluminum, palladium, gold or the like containing an alloy. Examples include paper and plastic films that have been made conductive by coating, vapor deposition, or lamination.

The intermediate layer 5 such as an adhesive layer or a barrier layer may be made of one of the high molecular weight polymers used as the binder resin.
Alternatively, organic polymer substances such as polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, or aluminum oxide are used.

The photoreceptor of the present invention has the configuration exemplified above, and as is clear from the examples described later, the photoreceptor has charging characteristics, sensitivity characteristics,
In particular, it has excellent sensitivity characteristics in the long wavelength region, and also shows little fatigue deterioration even when used repeatedly, and has excellent characteristics as a printer for semiconductor lasers.

5. Examples Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited thereto.

First, the following experiment was conducted. That is, a 0.05 μm thick undercoat layer made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J (manufactured by Block Chemical Co., Ltd.)" was provided on a polyester film, and exemplified compound I was applied thereon. -) 2g to 1°2-dichloroethane 110
I117! Mixed with ball mill type: Hitachi Seisakusho) K
The transmission spectrum was measured.

Exemplary compounds I-), I-(lη, ■
-94), I-+21 and the comparative compound (1
), +2), +31, +41t-, ε790/aλmax is 79 of the compound.
It shows the value obtained by dividing the spectral absorption intensity at 0 nm by the intensity at λmax (λmax is the wavelength showing maximum absorption).

From Table 2, the necessary comparative compounds + for symmetric trisazo compounds
21, +31, +41 and the comparative compound f11 in which the coupler is naphthol ASMX even though it is an asymmetric trisazo compound, the compounds of the present invention I-), ■-)
, Inη, I -tl4), I -+21 shows that the spectral absorption spectra of I -+21 are significantly extended toward longer wavelengths. (i.e., when comparative compound (2) is used instead of comparative compound (5)), λmix becomes 451 m longer wavelength.On the other hand, in the case of an asymmetric trisazo compound, for example, when comparative compound (1) is replaced with When Exemplary Compound I-) is used, λmax is as large as 92 nm, and a significantly longer wavelength is obtained.

Further, from the values of s790/@λmax in Table 2, it can be seen that the compounds of the present invention exhibit high spectral absorption characteristics even at 79Q nm.

Example 1 A conductive support made of a polyester film laminated with aluminum foil was coated with a 0.0 mm thick film made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-104 (manufactured by Tanezu Kagaku Co., Ltd.)". A 0.05 pm intermediate layer was provided, and a 1-thiethylenediamine solution of exemplified compound 1.-tl) was applied thereon to a dry film thickness of 0.3 μm to form a carrier generation layer (CGL).

On the other hand, a coating solution for forming a carrier transport layer was prepared by hand NAK. That is, 6t of exemplified compound (II-10) and polycarbonate resin "Panlite L-1250J (manufactured by Kijin Kasei Co., Ltd.) s, sr were mixed with 40% of 1,2-dichloroethane.
-, and the resulting solution was added to the monochlorobenzene solution and thoroughly mixed to complete the preparation.

The resulting solution was applied onto the CGL using a doctor blade and dried at 80°C for 1 hour to give a thickness of 13 pm.
A CTL was formed, thereby producing an electrophotographic photoreceptor of the present invention.

The photoreceptor produced in this way was used in an electrophotographic copying machine rU-
When it was attached to a modified Bix2000RJ (manufactured by Konishiroku Photo Industry Co., Ltd.) and an image was copied, a sharp copy image was obtained.

Example 2 A vinyl chloride-vinyl acetate-maleic anhydride copolymer [S-LEC MF-10J (Sekisui Chemical Co., Ltd.) was coated on the surface of an aluminum drum with a diameter of 100+w.
．． An intermediate layer of 05 μm is provided, and exemplified compound I-
CGL
was formed.

Furthermore, KX exemplified compound (II-io) 3ay
and polycarbonate resin “Panlite L-1250J”
(manufactured by Kijin Kasei Co., Ltd.) 502 and 1,2-dichloroethane 4
A drum-shaped electrophotographic photoreceptor was prepared by dissolving it in 00- and applying it to a film thickness of 12 μm after drying to form a CTL.

The spectral sensitivity of this photoreceptor at 790nm is 0.80μ
J/cm" (half exposure amount).

Next, this photoreceptor was subjected to a photographic test using an experimental machine equipped with a semiconductor laser (790 nm) with a laser beam intensity of 0.85 mW on the surface of the photoreceptor.

After the surface of the photoreceptor was charged to -6 KV, it was exposed to laser light and subjected to reversal development at a bias voltage of -350 V. A good image without capri was obtained.

Moreover, this did not change even after repeating 20,000 times.

Example 3 In Example 2, exemplified compounds 1-H1I-aft, I-fi, I-+141 were used in place of exemplified compounds I-1).
．． A drum-shaped photoreceptor was obtained in the same manner except that I-(2) and comparative compounds (11 and +21) were used.

The spectral sensitivity of each photoreceptor at 7901111 was as shown in Table 3 below.

(The following is a margin, continued on the next page) Table 3 From these results, it can be seen that the compound of the present invention has higher sensitivity than the comparative compound.

Furthermore, in the actual photographic test using the experimental machine described in Example 2, the photoreceptor using the compound of the present invention gave good images without capri, and these were io and oo.

No matter how many times it was repeated, it didn't change.

Implementation row 4 A conductive support made of aluminum foil laminated on a polyester film was coated with a layer of vinyl chloride-vinyl acetate-maleic anhydride copolymer "Nislex MF-i0J (manufactured by Okisui Kagaku Co., Ltd.)" with a thickness of 0. .1μm intermediate layer is provided,
On top of that, 1.52 of the trisazo compound shown as exemplified compound (I-24) and a polycarbonate resin [Panlite L
-1250 J O, 75 t was added to 100 tnt of 1,2-dichloroethane and dispersed in a ball mill for 24 hours. The resulting dispersion was applied onto the intermediate layer with a doctor blade and thoroughly dried to a thickness of 0. 5 μm C
GL was formed.

Next, an exemplary compound (
The thickness was 1 in the same manner as in Example 1 except that II-10) was used.
A CTL of 2 μm was formed, thereby producing an electrophotographic photoreceptor (Sample 1) of the present invention.

Examples 5 to 10 Photoreceptors were prepared in the same manner as in Example 4, except that the compounds shown in Table 4 were used as the carrier-generating substance (CGM) and the carrier-transporting substance (CTM).
) to (sample 9).

Comparative Examples 1 to 2 A photoreceptor was prepared in the same manner as in Example 11PI14, except that an oxadiazole compound having the following structure was used as the carrier transport substance, and this was designated as Comparative Sample 1.

(R-1) Next, the above comparative photoreceptor and the photoreceptor of the present invention in rows 4 to 10 were respectively installed in an electrometer model 5P-428 (manufactured by Kawaguchi Electric Co., Ltd.), and charged. The voltage applied to the discharge electrode of the device was set to 16 KV, and the charging operation was performed for 5 seconds.
Immediately after this charging operation, the surface potential of the photosensitive layer surface is Vo
, the exposure amount required to attenuate the surface potential from -500M to -5o (V) is E::0 (lux・see).
, and the residual potential after 301ux・see exposure as VB(t
/) and these were measured. In addition, the exposure amount required to cause the surface potential to be severely attenuated by discharging for 5 seconds after the above-mentioned charging and then exposing it to light was defined as the half-reduction exposure amount EA. The results are shown in Table 4 below.

Table 4 As is clear from the results, the photoreceptor of the present invention has good photosensitivity, etc.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are sectional views of six examples of electrophotographic photoreceptors. be. In addition, in the symbols shown in the drawings, 1......... Substrate 2...
......Carrier generation layer (CG L) 3...
......Carrier transport layer (CTL) 4
・・・・・・・・・・・・・・・Photosensitive layer. Agent: Patent Attorney Hiroshi Aisaka (1 other person) Figure 1 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. In a photoreceptor having a photosensitive layer consisting of a carrier generation phase and a carrier transport phase, a trisazo compound represented by the following general formula CI') is contained in the carrier generation phase, and the trisazo compound represented by the following general formula Photoreceptor 0 characterized in that a hydrazone compound represented by (n) is contained in the carrier transport phase General formula [■]: (However, in this general formula, A is a substituted or unsubstituted phenyl group or Represents a naphthyl group, Arl and 4s are not the same group and each represents a substituted or unsubstituted carbocyclic aromatic group 0) General formula [■]: 1 (However, R1 is a substituted or unsubstituted carbocyclic aromatic group. R2 is a substituted or unsubstituted alkyl group, aralkyl group, or aryl group; W is a hydrogen atom, an alkyl group, or an alkoxy group; R″ and R6 are substituted or unsubstituted alkyl groups, aralkyl groups, or aryl groups )