JPS6325664B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a carrier transport layer combined with a layer of material that absorbs light and generates carriers. Recently, in the electrophotography industry, a carrier generation layer containing a substance that absorbs visible light and generates charged carriers, and a carrier transport layer that transports either or both of the positive and negative charged carriers generated in this carrier generation layer. It has been proposed that the photosensitive layer of an electrophotographic photoreceptor be constructed by combining the following. In this way, the generation of charged carriers and
By assigning the two basic functions of transport in the photosensitive layer to separate substances or substance systems, the range of substances that can be used in the composition of the photosensitive layer is widened, and the substance or substance system that optimally fulfills each function. This makes it possible to independently select the characteristics required in the electrophotographic process, such as high surface potential when charged, high charge retention, high surface strength, and photosensitivity. It becomes possible to construct a photosensitive layer with excellent properties such as high viscosity and high stability during repeated use. Conventionally, as such a photosensitive layer, the following ones are known, for example. (1) A carrier generation layer made of amorphous selenium or cadmium sulfide and a carrier transport layer made of poly-N-vinylcarbazole are laminated. (2) A carrier generation layer made of amorphous selenium or cadmium sulfide, and 2,4,7-trinitro-9
- laminated with a carrier transport layer containing fluorenone. (3) a carrier generation layer made of a perylene derivative;
A carrier transport layer containing an oxadiazole derivative (U.S. Patent No.
3871882). (4) A layer in which a carrier generation layer made of chlordiane blue or methylscalyllium and a carrier transport layer containing a pyrazoline derivative are laminated (see JP-A-51-90827). (5) A carrier generation layer made of amorphous selenium or its alloy and a carrier transport layer containing a polyarylalkane aromatic amino compound are laminated (Japanese Patent Application No. 147251/1982). (6) A layer in which a carrier generation layer containing a perylene derivative and a carrier transport layer containing a polyarylalkane aromatic amino compound are laminated (Japanese Patent Application No. 19907/1983). As described above, many types of photosensitive layers are known, but in many conventional electrophotographic photoreceptors having such photosensitive layers, the electricity of the photosensitive layer increases when subjected to repeated electrophotographic processes. It has the disadvantage of severe mechanical fatigue and a very short service life. That is, although 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 rate at the final stage of discharge is low. Because the charge is extremely small, it is impossible to completely eliminate the charge even if the charge is removed by exposure to a large amount of light, and a fairly high residual potential remains.Moreover, this residual potential increases cumulatively each time the electrophotographic process is repeated. Eventually, due to a small number of continuous copies, the residual potential exceeds its permissible limit, making it unusable as an electrophotographic photoreceptor. It is certainly possible to restore some types of photoreceptors to a usable state, but in order to recover, it is necessary to leave the photoreceptor in a dormant state for a considerable period of time, or to perform 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 possible before the next unusable state is reached is greatly reduced. For example, in an electrophotographic photoreceptor that uses a carrier transport material with electron-donating properties and combines it with a carrier-generating material, a small amount of A method has been proposed in which a Lewis acid of 100% is added to the layer containing the carrier transport material.
However, although this method is effective for photoreceptors using specific electron-donating carrier transport materials,
Photoreceptors using many other electron-donating carrier transport materials cannot sufficiently prevent the accumulation of residual potential. In particular, in the case of photoreceptors using carrier transport materials such as polyarylalkane-based aromatic amino compounds, it is difficult to obtain practical repeatability characteristics due to deterioration factors such as ultraviolet rays. The present invention eliminates the above-mentioned drawbacks and provides a photosensitive layer that does not undergo fatigue deterioration during repeated electrophotographic processes, has a long service life, and has residual potential characteristics that do not cause any practical problems during static elimination operations. ,
Therefore, continuous copying can be performed many times without performing a recovery operation, and the photosensitivity of the photosensitive layer is stable against active light, especially ultraviolet light, irradiated from an exposure lamp, an erasure lamp, etc. It is an object of the present invention to provide an electrophotographic photoreceptor that has high mechanical strength and can function stably over a long period of time in these respects. As a result of intensive research to achieve the above objects, the present invention was completed by discovering that these objects can be significantly improved by the following method. In the present invention, a mixture of an aromatic amino compound represented by the following general formula [A] and a carbazole derivative represented by the following general formula [B] is added as a carrier transport material to a photosensitive layer consisting of a laminate of a carrier generation layer and a carrier transport layer. It consists of containing it as. General formula [A]: [In the formula, X is an oxygen atom, a sulfur atom,

【formula】

【formula】

[Formula] (-CH=CH) _-o , or

Represents [formula]. However, R ₅ and R ₆ are hydrogen atoms, halogen atoms, acyl groups, hydroxyl groups, substituted or unsubstituted alkyl groups, cycloalkyl groups, alkenyl groups, cycloalkenyl groups, aryl groups, alkoxy groups, aryloxy groups, or It represents an amino group, R ₅ and R ₆ may jointly form a hydrocarbon cyclic group or a heterocyclic group, and n is 1 or 2. R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, or an aryl group, and R ₁ and R ₂ and/or R ₃ and R ₄ may form a nitrogen-containing heterocyclic group. R ₇ , R ₈ , R ₉ and R ₁₀ are hydrogen atoms, halogen atoms, acyl groups, hydroxyl groups, substituted or unsubstituted alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, alkoxy groups, aryloxy groups, or Represents an amino group. ] In this general formula [A], R ₁ , R ₂ , R ₃ , R ₄ ,
The alkyl groups of R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ have 1 to 40 carbon atoms, the alkenyl groups have 2 to 40 carbon atoms, cycloalkyl groups and Each cycloalkenyl group has 5 to 7
Member ring, alkoxy group has 1 to 1 carbon atoms
40, and the aryl group is preferably a phenyl group, tolyl group or naphthyl group. Also, when R ₁ and R ₂ and/or R ₃ and R ₄ jointly form a nitrogen-containing heterocyclic group, the heterocyclic group, and when R ₅ and R ₆ are heterocyclic groups, the heterocyclic group Each of the ring groups may be arbitrary, but is preferably a 5- to 7-membered ring containing a nitrogen atom, an oxygen atom, and/or a sulfur atom; It may be fused with a heterocyclic group or a hydrocarbon ring group. Note that this heterocyclic group may be either saturated or unsaturated. Furthermore, when R ₅ and R ₆ jointly form a hydrocarbon cyclic group or a heterocyclic group, the cyclic group may be either saturated or unsaturated, and the number of constituent atoms thereof is 3 to 10.
It is preferable that Further, when each group in this general formula [A] is substituted, the substituent is, for example, a halogen atom, an acyl group, a hydroxyl group, an alkyl group (preferably one having 1 to 40 carbon atoms),
A cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group (preferably a phenyl group, a tolyl group, or a naphthyl group), an alkoxy group (preferably one having 1 to 40 carbon atoms), an aryloxy group, or an amino group. . General formula [B]: [In the formula, R ₁ and R ₂ are hydrogen atoms, halogen atoms,
Each represents a substituted or unsubstituted alkyl group, alkoxy group, aryloxy group, aryl group, amino group or hydroxyl group, R ₃ and R ₄ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, Ar represents a substituted or unsubstituted divalent carbocyclic aromatic ring, or a heterocyclic aromatic ring containing an oxygen atom or a sulfur atom. ] Typical specific examples of the aromatic amino compound represented by the general formula [A] are listed below. (A-1) 1,1-bis(4-N,N-dimethylaminophenyl)-2-methylpropane (A-2) 1,1-bis(4-N,N-dimethylamino-2-methylphenyl ) Cyclohexane (A-3) 1,1-bis(4-N,N-dimethylamino-2-methylphenyl)-1-(4-methoxyphenyl)methane (A-4) 1,1-bis(4- N,N-dimethylamino-2-methylphenyl)-1-(4hydroxyphenyl)methane (A-5) 1,1-bis(4-N,N-dimethylamino-2-methylphenyl)-1-(2 ,4-
dimethoxyphenyl)methane (A-6) 1,1-bis(4-N,N-dimethylamino-2-ethylphenyl)-1-(2,4-
dimethylphenyl)methane (A-7) 1,1-bis(4-N,N-dimethylamino-2-methoxyphenyl)-2-methylpropane (A-8) 1,1,2,2-tetrakis (4-
N,N-dimethylamino-2-methylphenyl)ethane (A-9) 1,1,5,5-tetrakis(4-
N,N-dimethylamino-2-methylphenyl)pentane (A-10) 1,1-bis(4-N,N-diethylaminophenyl)heptane (A-11) 1,1-bis(4-N,N -diethylaminophenyl)-1-phenylmethane (A-12) 1,1-bis(4-N,N-diethylaminophenyl)-1-(2-thienyl)methane (A-13) 1,1-bis( 4-N,N-diethylaminophenyl)-1-N-piperidylmethane (A-14) 3,3-diphenylaryritene-4,
4'-bis(N,N-diethyl-m-toluidine) (A-15) 1,1-bis(4-N,N-diethylamino-2-methylphenyl)heptane (A-16) 1,1-bis( 4-N,N-diethylamino-2-methylphenyl)-1-phenylmethane (A-17) 1,1-bis(4-N,N-diethylamino-2-methylphenyl)-3-phenylpropane (A-18) α, α, α′, α′-tetrakis (4-
N,N-diethylamino-2-methylphenyl)-p-xylene (A-19) 1,1-bis(4-N,N-diethylamino-2-ethylphenyl)-4-methylcyclohexane (A-20) 1,1 -bis(4-N,N-diethylamino-2-ethylphenyl)-2-phenylethane (A-21) 1,1-bis(4-N,N-diethylamino-2,5-dimethylphenyl)heptane (A- 22) 1,1-bis(4-N,N-diethylamino-2,5-dimethoxyphenyl)-1-
Phenylmethane (A-23) 1,1-bis(4-N-ethyl-N-
Methylamino-2-methylphenyl)-3-methylcyclohexane (A-24) 1,1-bis[4-N,N-di(p-
tolyl)aminophenyl]cyclohexane (A-25) 1,1-bis[4-N,N-di(p-
tolyl)amino-2-methylphenyl]cyclohexane (A-26)1,1-bis(4-N-ethyl-N-
pendylaminophenyl)-1-cyclohexylmethane (A-27) 1,1-bis(4-N-methyl-N-
benzylamino-2-methylphenyl) normal butane (A-28) 1,1-bis(4-N-ethyl-N-
benzylamino-2-methoxyphenyl) normal butane (A-29) 1,1-bis(4-N-ethyl-N-
benzylamino-2-methoxyphenyl)-1
-Cyclohexylmethane (A-30) 1,1-bis(4-N,N-dibenzylaminophenyl)propane (A-31) 1,1-bis(4-N,N-dibenzylaminophenyl) Normal butane (A-32) 1,1-bis(4-N,N-dibenzylaminophenyl)pentane (A-33) 1,1-bis(4-N,N-dibenzylaminophenyl)- 2-Methylpropane (A-34) 1,1-bis(4-N,N-dibenzylaminophenyl)cyclohexane (A-35) 1,1-bis(4-N,N-dibenzylaminophenyl) )-1-cyclohexylmethane (A-36) 1,1-bis(4-N,N-dibenzylaminophenyl)-1-phenylmethane (A-37) 1,1-bis(4-N,N- dibenzylamino-2-methylphenyl)propane (A-38) 1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)n-butane (A-39) 1,1-bis(4-N , N-dibenzylamino-2-methylphenyl)pentane (A-40) 1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)cyclohexane (A-41) 1,1-bis(4 -N,N-dibenzylamino-2-methylphenyl)-1-cyclohexylmethane (A-42) 1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)-1-phenylmethane (A- 43) 1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)-1-(2-furyl)methane (A-44) 1,1-bis(4-N,N-dibenzyl Amino-2-methylphenyl)-1-(4-pyridyl)methane (A-45) 1,1-bis(4-N,N-dibenzylamino-2-methoxyphenyl)propane (A-46) 1, 1-bis(4-N,N-dibenzylamino-2-methoxyphenyl)-n-butane (A-47) 1,1-bis(4-N,N-dibenzylamino-2-methoxyphenyl)- 2-Methylpropane (A-48) 1,1-bis(4-N,N-dibenzylamino-2-methoxyphenyl)-1-cyclohexylmethane (A-49) 1,1-bis(4-N , N-dibenzylamino-2,5-dimethylphenyl) normal butane (A-50) 1,1-bis(4-N,N-dibenzylamino-2,5-dimethylphenyl)-1-
Cyclohexylmethane (A-51) 1,1-bis(4-N,N-dibenzylamino-2,5-dimethoxyphenyl)n-butane (A-52) 1,1-bis(4-N-morpholinof) enyl)-1-(2-furyl)methane (A-53) 1,1-bis(4-N-piperazinylphenyl)-1-(2-furyl)methane (A-54) 4,4'- Bis-[N,N-diethylamino]tetraphenylmethane Examples of carbazole derivatives useful in the present invention represented by the general formula [B] include those having the following structural formula. Furthermore, the present invention will be specifically explained with reference to the drawings. In the present invention, as shown in FIG. 1, a carrier generating layer 2 containing a carrier generating substance as described later as a main component is formed on a conductive support 1, and the carrier generating layer 2 is formed on a conductive support 1. A carrier transport layer 3 containing a transport substance as a main component is laminated and formed, and the carrier generation layer 2
and the carrier transport layer 3 constitute a photosensitive layer 4. 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, or brass can be used. For example, as shown in FIG. 2, a conductive layer 1 is placed on an insulating substrate 1A.
The conductive support 1 can also be configured by providing B. In this case, the substrate 1A is suitably flexible, such as paper or a plastic sheet, and has sufficient strength against stress such as bending and tension. The conductive layer 1B can also be provided by laminating metal sheets, vacuum depositing metal, or by other methods. The carrier generation layer 2 is made of a carrier generation substance described below alone, or a suitable binder resin is added thereto, or a substance having a high mobility for carriers of specific or non-specific polarity, that is, a carrier transport substance is added. It can be formed by Specific forming methods include, for example, a method in which a carrier-generating substance is vacuum-deposited on the support, and a method in which a carrier-generating substance is dissolved or dispersed in a suitable solvent and then applied and dried. In this latter method, a binder resin or a carrier transport material may be added, and in that case, the ratio of carrier generating material: binder resin: carrier transport material is 1:0 by weight.
-100:0-500, particularly preferably 1:0-10:0-50. As the carrier generating substance, any inorganic pigment or organic dye can be used as long as it absorbs visible light and generates free carriers. In addition to inorganic pigments such as amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide, cadmium selenide, cadmium selenide sulfide, mercury sulfide, lead oxide, lead sulfide, the following representative examples Organic dyes such as those shown in may also be used. (1) Azo dyes such as monoazo dyes, polyazo dyes, metal complex azo dyes, pyrazolone azo dyes, stilbene azo dyes, and thiazole azo dyes (2) Perylene dyes such as perylenic anhydride and perylenic acid imide (3) Anthraquinone Anthraquinone or polycyclic quinone dyes such as derivatives, anthorone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives and isoviolanthrone derivatives (4) Indigoid dyes such as indigo derivatives and thioindigo derivatives (5) Metals Phthalocyanine dyes such as phthalocyanine and metal-free phthalocyanine (6) Carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes, xanthene 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 dyes (10) Nitro dyes (11) Nitroso dyes (12) Benzoquinone and naphthoquinone dyes (13) Naphthalimide dyes (14) Bisbenzimidazole derivatives Perinone dyes (15) Quinacridone dyes Binder resins used here include, for example, polyethylene, polypropylene, acrylic resins, methacrylic resins, vinyl chloride resins, vinyl acetate resins, epoxy resins, polyurethane resins, phenolic resins, and polyesters. Addition polymer resins such as resins, alkyd resins, polycarbonate resins, silicone resins, melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more repeating units of these resins, e.g. Examples include vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and the like. However, the binder resin is not limited to these, and all resins commonly used for such purposes can be used. As the carrier transport substance having a high mobility for carriers of specific or non-specific polarity that can be added to the carrier generation layer, specific carrier transport substances described below, which are used in the construction of the carrier transport layer 3 etc. in the present invention, may be used. Although it can be used in part or in whole, other carrier transport materials may be used in consideration of the performance as an electrophotographic photoreceptor. 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, etc. 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, 4-nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride,
Tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, bromanil, dichlorodicyanoparabenzoquinone , anthraquinone,
Dinitroanthraquinone, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 9-fluorenylidene-[dicyanomethylenemalonodinitrile], polynitro-9-fluorenylidene- [dicyanomethylenemalonodinitrile], picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, bentafluorobenzoic acid, 5-nitrosalicylic acid,
Examples include 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 = 100:0.01~
200 preferably 100:0.1-100. The carrier generation layer 2 formed as described above preferably has a thickness of 0.005 to 20 microns,
Particularly preferred is 0.1 to 5 microns. Further, the carrier transport layer 3 is made of an aromatic amino compound [A] and a carbazole derivative [B] which will be described later.
It can be formed by using a mixture of the above as a carrier transport material, dissolving or dispersing it in an appropriate solvent together with an appropriate binder resin as necessary, applying a coating solution obtained and drying it, or by other methods. . The blending ratio of the aromatic amino compound [A] and the carbazole derivative [B] is preferably such that the carbazole derivative [B] accounts for 1% by weight or more and 80% by weight or less of the total carrier transport substance [A] + [B]. It is particularly preferably 5% by weight or more and 50% by weight or less. If it is less than 1 weight percent, the residual potential will increase sharply during repeated use, and the desired repeat stability cannot be obtained, and if it exceeds 80 weight percent, the charging potential will decrease greatly during repeated use, and the desired repeat stability will not be obtained. Examples of binder resins that can be used in the carrier transport layer include polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, alkyd resin, polycarbonate resin, Addition polymerization resins such as silicone resins and melamine resins,
Polyaddition type resins, polycondensation type resins, and copolymer resins containing two or more of the repeating units of these resins, such as vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, etc. Examples include polymer resins. However, binder resins are not limited to these,
All resins commonly used for such applications can be used. 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, and when polycarbonate is used as the binder resin, it is preferably 20 to 500 parts by weight per 100 parts by weight of the binder resin. The use of ˜200 parts by weight of total carrier transport material is preferred as it provides excellent electrophotographic properties. Further, 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 this 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 completely or partially the same, or in some cases, they may be completely different. I don't mind. The addition ratio of the electron-accepting substance to the carrier transport layer is such that the total carrier transport substance:electron-accepting substance is 100:0.01 to 100, preferably 100:0.1 to 50, by weight. The thickness of the carrier transport layer 3 formed as described above is 2 to 100 microns, preferably 5 to 30 microns. In the present invention, by configuring the carrier transport layer as described above, the present invention has the greatest effect in that it performs a stable function especially when used continuously. This effect is due to the fact that in the aromatic amino compound represented by the general formula [A],

In the case of the polyarylalkane aromatic amino compound represented by the formula [Formula], at least one of R ₁ and R ₂ and R ₃ and R ₄ are present in the general formula [A].
at least one of them is an aralkyl group, and
At least one of R ₇ and R ₈ and at least one of R ₉ and R ₁₀ is an electron-donating substituent having a -I effect (negative induction effect) or -M effect (negative mesomery effect), that is, a halogen atom, a hydroxyl group, or a substituted or unsubstituted alkyl group,
It is noticeable when the compound has a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an aryl group, an alkoxy group, an aryloxy group, or an amino group. Further, when the aralkyl group is a benzyl group, the above effect is particularly remarkable. When the electrophotographic photoreceptor of the present invention is continuously subjected to an electrophotographic process, there is little electrical fatigue in the photosensitive layer, and there is no cumulative increase in residual potential that cannot be removed in the photosensitive layer 4, resulting in a long service life. can get. Moreover, there are no restrictions on continuous copying, and it is possible to always form a copy image stably without fogging on the background. The electrophotographic photoreceptor of the present invention has high stability against ultraviolet rays, has little change over time in characteristics such as acceptance potential, sensitivity, and residual potential in bright places, and therefore has little natural deterioration due to use, and is extremely easy to maintain and handle. It's convenient. Furthermore, the carrier transport layer 3 can contain a binder resin at a relatively high concentration without impairing its good properties, thereby increasing the mechanical strength of the photosensitive layer 4. This increases resistance to mechanical damage, such as development resistance and cleaning resistance, and in this respect also extends the service life. Although it is not clear why the electrophotographic photoreceptor of the present invention exhibits excellent characteristics, it is one of the elements of the carrier transport material used in combination with the carrier generation material to form the photosensitive layer of the photoreceptor. A carbazole derivative represented by the general formula [B] is itself a photoconductive substance that generates carriers when exposed to ultraviolet light, and the carriers generated by ultraviolet light are trapped in a layer containing a carrier transport substance. It is presumed that this is to neutralize holes and improve carrier transport efficiency. If only the above-mentioned carbazole derivative is used as the carrier transport material, excellent abrasion resistance on the surface of the photosensitive layer can be obtained, but the carrier transport function is poor and the carriers from the carrier generation material cannot be efficiently transported. Can not. If only the aromatic amino compound represented by the above general formula [A] is used, the carrier transport function is excellent, but the film forming property is poor and the transport function decreases during repeated use due to deterioration due to ultraviolet light. There are drawbacks to doing so. That is, sufficient effects in the present invention are exhibited by a photosensitive layer containing a combination of the above-mentioned carbazole derivative and an aromatic amino compound as a carrier transport material. The present invention has been explained above according to the specific configuration example shown in FIG. 1 or FIG. 2, but in the present invention,
It is sufficient if the above-mentioned components are contained in the carrier transport layer to be combined with the carrier generation layer, and the mechanical structure of the electrophotographic photoreceptor can be arbitrarily selected. For example, as shown in FIG.
A suitable intermediate layer 5 is provided thereon, a carrier generation layer 2 is formed thereon, and a carrier transport layer 3 is formed thereon.
may be formed. This intermediate layer 5 includes a photosensitive layer 4
It has a function of preventing free carriers from being injected from the conductive support 1 into the photosensitive layer 4 during charging, and a function as an adhesive layer that integrally adheres the photosensitive layer 4 to the conductive support. You can force it. Materials for the intermediate layer 5 include metal oxides such as aluminum oxide and indium oxide, acrylic resins, methacrylic resins, vinyl chloride resins, vinyl acetate resins, epoxy resins, polyurethane resins, phenolic resins, polyester resins, alkyd resins, Polymer materials such as polycarbonate resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, and vinyl chloride-vinyl acetate-maleic anhydride copolymer resin can be used. Further, as shown in FIG. 4, a carrier transport layer 3 is formed on the conductive support 1 with or without the intermediate layer 5, a carrier generation layer 2 is formed thereon, and a photosensitive layer 4 is formed. may be configured. Examples of the present invention will be described below, but the present invention is not limited thereto. Example 1 A vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (Sekisui Chemical Co., Ltd.
Co., Ltd.) with a thickness ^of approximately 0.1 micron was provided, and the polycyclic quinone dye 4, 10-Dibromanthanthrone (Monolite Red 2YC.I. No. 59300) was evaporated onto the intermediate layer to form a carrier generating layer approximately 0.5 microns thick. On the other hand, the aromatic amino compound shown in (A-46)
11.25 g, 1.5 g of the carbazole derivative shown in (B-13), and 15 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Chemicals) were dissolved in 100 ml of 1,2-dichloroethane, and the resulting solution was dissolved. A carrier transport layer having a thickness of 12 microns was formed by coating the carrier generation layer using a doctor blade and drying it at 80° C. for 1 hour. Created. Example 2 Exemplified compound (A-
38) was used in the same manner as in Example 1, except that a thickness of approximately
An electrophotographic photoreceptor of the present invention (Sample No. 2) was prepared by forming a carrier generation layer of 0.5 microns and a carrier transport layer of 12 microns in thickness. Example 3 Exemplified compound (B-
14) was used in the same manner as in Example 1, except that a thickness of approximately
An electrophotographic photoreceptor (Sample No. 3) of the present invention was prepared by forming a carrier generation layer of 0.5 microns and a carrier transport layer of 12 microns in thickness. Example 4 4 g of 4,10-dibromanthanthrone was added to a solution in which 2 g of polycarbonate resin, 2 g of exemplified aromatic amino compound (A-46), and 0.2 g of tetrabromo phthalic anhydride were dissolved in 100 ml of 1,2-dichloroethane. This dispersion was applied onto a conductive support having the same intermediate layer as in Example 1 to form a carrier generating layer with a thickness of 1 micron. On the other hand, exemplary aromatic amino compound (A-46)
11.25g, 1.5g of carbazole derivative (B-13), 0.03g of tetrabromophthalic anhydride, and 15g of polycarbonate resin in 100ml of 1,2-dichloroethane.
The resulting solution was applied onto the carrier generation layer using a doctor blade and dried at 80° C. for 1 hour to form a carrier transport layer with a thickness of 12 microns. (Sample No. 4) was created. Example 5 In place of the polycyclic quinone dye in Example 1, a perylene dye, N,N'-dimethylperylene-3,4,9,10-tetracarboxylic acid diimide (Paliogen Maroon 3920C.I.No. 71130) was used in the same manner as in Example 1, except that a carrier generation layer with a thickness of about 0.5 microns and a carrier transport layer with a thickness of 12 microns were formed.
No. 5) was created. Example 6 On a conductive support made of polyethylene terephthalate with a thickness of 100 microns on which aluminum was vapor-deposited, selenium was vapor-deposited for 1 minute at an evaporation source temperature of 300°C in a vacuum atmosphere of 2 to 3 × 10 ^-5 Torr, Thickness 1
A carrier generation layer consisting of micron-sized amorphous selenium was formed. Next, the same carrier transport layer forming solution as used in Example 1 was applied and vacuum dried at 40°C for 24 hours to form a carrier transport layer with a thickness of 12 microns. .6) was created. Comparative Example 1 15 g of the exemplified aromatic amino compound (A-46) and 15 g of polycarbonate resin were dissolved in 100 ml of 1,2-dichloroethane to prepare a carrier transport layer forming solution that does not contain the carbazole derivative of the present invention. This solution was applied onto the same carrier generation layer as in Example 1 to form a carrier transport layer having a thickness of 12 microns, and a comparative electrophotographic photoreceptor (comparative sample No. 1) was prepared. Comparative Example 2 An attempt was made to create a carrier transport layer that does not contain aromatic amino compounds by adding 15 g of the exemplified carbazole derivative (B-13) and 15 g of polycarbonate resin to 100 ml of 1,2-dichloroethane, but the solubility of the above compound was low. Unfortunately, the predetermined amount could not be dissolved, so the amount was reduced to 6 g and a carrier transport layer forming solution was prepared again.
This solution was applied on the same carrier generation layer as in Example 1 to form a carrier transport layer with a thickness of 12 microns.
A comparative electrophotographic photoreceptor (comparative sample No. 2) was prepared. Comparative Example 3 15 g of polycarbonate resin, 15 g of exemplified aromatic amino compound (A-46), and 0.3 g of 2,4,7-trinitro-9-fluorenone were dissolved in 100 ml of 1,2-dichloroethane, and the exemplified carbazole derivative was not included. A carrier transport layer forming solution was prepared, and this solution was applied onto the same carrier generation layer as in Example 1 to form a carrier transport layer with a thickness of 12 microns, and a comparative electrophotographic photoreceptor (comparative sample No. 3) was prepared. It was created. Sample No. 1 obtained in each of the above Examples and Comparative Examples
~ No. 6 and comparative samples No. 1 and No. 2 were attached to an electrometer SP-428 type (manufactured by Kawaguchi Electric Seisakusho Co., Ltd.), and the charging operation was performed for 5 seconds with the voltage applied to the charger discharge electrode set to -6 kV. and measure the charged potential V _p (V) on the surface of the photosensitive layer immediately after this charging operation and the amount of irradiation light E _1/2 (lx sec) required to attenuate this charged potential V _p to 1/2. did. The results are shown in Table 1.

【table】

[Table] Also, Sample No. 1 obtained in Example 1 and Comparative Example 1
Comparative sample No. 1 obtained in
−100UV” (manufactured by Tokyo Shibaura Electric Co., Ltd.) at a distance of 5 cm.
When a similar measurement was performed with irradiation for seconds, the sample
In No. 1, there were small changes in V _p = -760 (V) and E _1/2 = 2.9 (lux・sec), whereas in comparison sample No. 1, V _p
= -825 (V), E _1/2 = 6.5 (lx·sec), the sensitivity decreased significantly, and the stability against ultraviolet rays of sample No. 1 obtained in Example 1 was recognized. Furthermore, the aforementioned samples No. 1 to No. 6 and comparative sample No. 1,
No. 2 was attached to a dry electronic copying machine U-Bix2000R (manufactured by Konishiroku Photo Industry Co., Ltd.) to perform continuous copying, and black paper potential V _b (v) and white paper potential at an exposure aperture value of 2.5 were used.
V _w (v) electrostatic voltmeter
144D-1D (manufactured by Monroe Electronics, Inc.) was used for measurement before development. The results are shown in Table 2. The black paper potential here refers to the surface potential of the photoreceptor when the above copying cycle is performed using 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 the original is a blank paper. Represents electric potential.

【table】

[Table] The upper row shows the black paper potential V _b (v), and the lower row ( ) shows the white paper potential V _w (v). Note that the amount of variation indicates an increase, and indicates a decrease. From the results in Table 2, the sample photoreceptors all show that the amount of variation in the black paper potential and white paper potential after 5000 copies compared to the initial black paper potential and white paper potential is small and stable, but comparative sample No. 1 and In photoconductor No. 3, the amount of variation in both potentials is large, causing significant background fog in the image after 5,000 copies, and in photoconductor No. 2, a comparative sample, the image density decreases significantly due to a decrease in black paper potential. be understood.

[Brief explanation of the drawing]

FIG. 1 is an explanatory enlarged cross-sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention, FIG. 2 is an explanatory enlarged cross-sectional view showing another structure example of the present invention, and FIGS.
Each figure is an explanatory enlarged sectional view showing still another configuration example of the present invention. 1... Conductive support, 2... Carrier generation layer,
3... Carrier transport layer, 4... Photosensitive layer, 5... Intermediate layer, 1A... Support, 1B... Conductive layer.

Claims (1)

[Scope of Claims] 1. In an electrophotographic photoreceptor comprising a photosensitive layer formed of a laminate of a carrier generation layer and a carrier transport layer provided on a conductive support, the carrier transport layer has the following general formula [A]. ] An electrophotographic photoreceptor comprising an aromatic amino compound represented by the following formula [B] and a carbazole derivative represented by the following general formula [B]. General formula [A]: [In the formula, X represents an oxygen atom, a sulfur atom, [formula] [formula] [formula] (-CH=CH) _-o , or [formula]. However, R ₅ and R ₆ are hydrogen atoms, halogen atoms, acyl groups, hydroxyl groups, substituted or unsubstituted alkyl groups, cycloalkyl groups, alkenyl groups, cycloalkenyl groups, aryl groups, alkoxy groups, aryloxy groups, or amino represents the group,
R ₅ and R ₆ may jointly form a hydrocarbon cyclic group or a heterocyclic group, and n is 1 or 2. R ₁ , R ₂ , R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, or an aryl group, and R ₁ and R ₂ and/or R ₃ and R ₄ may form a nitrogen-containing heterocyclic group. R ₇ , R ₈ , R ₉ and R ₁₀ are hydrogen atoms, halogen atoms, acyl groups, hydroxyl groups, substituted or unsubstituted alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, alkoxy groups, aryloxy groups, or Represents an amino group. ] General formula [B]: [In the formula, R ₁ and R ₂ are hydrogen atoms, halogen atoms, substituted or unsubstituted alkyl groups, alkoxy groups,
represents an aryloxy group, an aryl group, an amino group, or a hydroxyl group; R ₃ and R ₄ represent a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; Ar represents a substituted or unsubstituted divalent carbocyclic group; Represents an aromatic ring, a heterocyclic aromatic ring containing an oxygen atom or a sulfur atom. 2. The electrophotographic photoreceptor according to claim 1, wherein at least one of the carrier generation layer and the carrier transport layer contains an electron-accepting substance.