JPS646453B2 - - 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 berylene 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 chlortien 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 Laid-Open No. 147251/1983). (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 photosensitive layer changes when repeatedly subjected to electrophotographic processes. It has the disadvantage of severe electrical fatigue and a very short service life. That is, 1
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, the discharge rate at the final stage of discharge is extremely low in this type of photosensitive layer. Therefore, even if the static electricity is removed by exposure to a large amount of light, it is impossible to completely eliminate the static electricity, 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 and the electrophotographic photoreceptor becomes unusable. Although it is possible to restore some types of photoreceptors to a usable state, this recovery requires leaving the photoreceptor in a dormant state for a considerable period of time, or subjecting it to appropriate heat treatment. Moreover, the residual potential cannot be restored 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. 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. An object of the present invention is to eliminate the above-mentioned drawbacks and provide an electrophotographic photoreceptor that suffers less fatigue deterioration during repeated electrophotographic processes and has a long continuous service life. Specifically, the present invention aims to improve the deterioration of characteristics during continuous use of an electrophotographic photoreceptor made of a laminate of a carrier generation layer and a carrier transport layer. More specifically, it improves the stability of an electrophotographic photoreceptor using an aromatic amino compound as a carrier transport material in the carrier transport layer against active species such as ozone and ultraviolet light, thereby improving the characteristic deterioration during continuous use. It is something. 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 styryl compound 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, R ₁ , R ₂ , R ₃ and R ₄ are hydrogen atoms, substituted or unsubstituted alkyl groups, cycloalkyl groups,
It represents an alkenyl group, a cycloalkenyl group, or an aryl group, and R ₁ and R ₂ and/or R ₃ and R ₄ may jointly form a nitrogen-containing heterocycle. 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. 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 amino represents the base
R ₅ and R ₆ may jointly form a carbocyclic group or a heterocyclic group, and n is 1 or 2. ] In this general formula [A], R ₁ , R ₂ , R ₃ ,
The alkyl group of R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ has 1 to 40 carbon atoms, the alkenyl group has 2 to 40 carbon atoms, and the cyclo 5 each as an alkyl group and a cycloalkenyl group
-7-membered rings, alkoxy groups having 1 to 40 carbon atoms, and aryl groups preferably phenyl, tolyl or naphthyl groups. 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 represent a substituted or unsubstituted phenyl group, and the substituent is an alkyl group, an alkoxy group, or a phenyl group. R ₃ is substituted/unsubstituted phenyl group, naphthyl group,
It represents an anthryl group, a fluorenyl group, or a heterocyclic group, and as a substituent, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, or a phenyl group is used. R ₄ represents hydrogen, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. ] In this general formula [B], R ₁ , R ₂ and R ₄ are alkyl groups having 1 to ₄₀ carbon atoms.
The alkoxy group preferably has 1 to 40 carbon atoms. The heterocyclic group for R ₃ is preferably a 5- to 7-membered ring containing a nitrogen atom, an oxygen atom, and/or a sulfur atom;
The member ring may be bonded to another heterocyclic group or hydrocarbon ring group. Note that this heterocyclic group may be either saturated or unsaturated. In addition, when each group in this general formula [B] is substituted, the alkyl group has 1 to 40 carbon atoms, and the alkoxy group has 1 to 40 carbon atoms. be. When R ₄ is an alkylamino group, the alkyl group has 1 to 10 carbon atoms. Typical specific examples of the aromatic amino compound represented by the general formula [A] will be 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-(4-hydroxyphenyl)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
-benzylaminophenyl)-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) enyl)-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-42) -43) 1,1-bis(4-N,N-dibenzylamino-2-methylphenyl)-1-(2-
furyl) methane (A-44) 1,1-bis(4-N,N-dibenzylamino-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-dibenzyl Amino-2-methoxyphenyl) normal 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-dimethyl phenyl) 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-morpholino phenyl)-1-(2-furyl)methane (A-53) 1,1-bis(4-N-piperazinyl phenyl)-1-(2-furyl)methane (A-54) 4,4' -bis(N,N-diethylamino)tetraphenylmethane Examples of the styryl compound useful in the present invention represented by the general formula [B] include those having the following structural formula. Although specific compounds have been listed above, the present invention is not limited to these. The present invention can also be achieved by a combination of the above-mentioned aromatic amino compound of the general formula [A] and the above-mentioned styryl compound of the general formula [B]. 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
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, tin, zinc, palladium, silver, indium, copper, 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 constructed by providing B. In this case, the substrate 1A is suitably made of paper, plastic sheet, or the like, which is flexible 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 Binder resins used here include, for example, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, and polyester. 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. Not only insulating resins such as vinyl chloride-vinyl acetate copolymer resin and vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, but also polymeric organic semiconductors such as poly-N-vinylcarbazole can be used.
Moreover, not only one type of binder resin but also a mixture of two or more types may 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-fluorenyritene-[dicyanomethylenemalonodinitrile], purinitro-9-fluorenylidene- [dicyanomethylenemalonodinitrile], picric acid, O-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic 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 uses a mixture of an aromatic amino compound [A] and a styryl compound [B], which will be described later, as a carrier transport material, and is dissolved or dispersed in a suitable solvent together with a suitable binder resin as necessary. It can be formed by applying and drying a coating solution obtained by applying a coating solution, or by other methods. The blending ratio of the aromatic amino compound [A] and the styryl compound [B] is preferably such that the styryl compound [B] accounts for 1% by weight or more and 80% by weight or less of the total carrier transport material [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. In addition to insulating resins such as polymer resins, poly-N
- Polymeric organic semiconductors such as vinyl carbazole can also be used. Moreover, not only one type of binder resin but also a mixture of two or more types may 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-based aromatic amino compound represented by the formula [Formula], significantly moreover, at least one of R ₁ and R ₂ and R ₃ and R ₄ in the general formula [A] are present.
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 - effect (negative induction effect) or -M effect (negative mesomery effect), that is, a halogen atom, This is particularly noticeable when the compound has a hydroxyl group, or a substituted or unsubstituted alkyl group, cycloalkyl group, alkenyl group, cycloalkenyl group, aryl group, alkoxy group, aryloxy group, or amino group. Furthermore, when a compound in which the aralkyl group is a benzyl group is used in combination with a specific example of the styryl compound of the general formula [B], the above effect is 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 from this point of view as well, the service life becomes longer. 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 certain styryl compound represented by the general formula [B] is
It is a photoconductive substance that itself generates carriers when exposed to ultraviolet light, and the carriers generated by ultraviolet light neutralize the holes trapped in the layer containing the carrier transport substance, improving carrier transport efficiency. It is assumed that. If only the styryl compound is used as the carrier transport substance, the acceptance potential tends to decrease with repeated use, making it difficult to maintain stable performance. If only the aromatic amino compound represented by the general formula [A] is used, the carrier transport function is excellent, but there is a drawback that the transport function deteriorates during repeated use due to deterioration due to ultraviolet light. That is, sufficient effects in the present invention are exhibited by a photosensitive layer containing a combination of the styryl compound 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, on the conductive support 1,
The photosensitive layer 4 may be constructed by forming the carrier transport layer 3 with or without the intermediate layer 5 and forming the carrier generation layer 2 thereon. Examples of the present invention will be described below, but the present invention is not limited thereto. Example 1 Vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (Sekisui Chemical Co., Ltd.) was deposited on a conductive support made of polyethylene terephthalate having a thickness of 100 microns and deposited with aluminum.
An intermediate layer of approximately 0.1 micron thick made of
Polycyclic quinone dye ⁴ ,
10-Dibromuanthrone (monolite red)
2YC.I.No. 59300) was deposited on the intermediate layer to form a carrier generation layer with a thickness of about 0.5 microns. On the other hand, the aromatic amino compound shown in (A-46)
10.5g and 4.5 of the styryl compound shown in (B-9)
g and polycarbonate resin “Panlite L-
1250'' (manufactured by Teijin Kasei) in 100 ml 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 obtain a thickness of A carrier transport layer of 12 microns was formed, and an electrophotographic photoreceptor (sample No. 1) of the present invention was prepared. 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 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 in the same manner as in Example 1 except that the exemplified compound (B-12) was used as the styryl compound. An electrophotographic photoreceptor (sample No. 3) was prepared. 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, exemplified aromatic amino compound (A-46) 10.5
g, styryl compound (B-9) 4.5g, tetrabromo phthalic anhydride 0.03g and polycarbonate resin
15g and dissolved in 100ml of 1,2-dichloroethane,
The obtained 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. .4) was created. Example 5 Poly-N-vinylcarbazole “Rubican”
M170” (manufactured by BASF) 5g monochlorobenzene
Dissolve in 50ml. Next, 6 g of the exemplified aromatic amino compound (A-46) and the exemplified styryl compound (B-9)
A solution obtained by dissolving 1.2 g of vicryl chloride, 0.02 g of vicryl chloride, and 3.5 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Kasei) in 40 ml of 1,2-dichloroethane was added to the monochlorobenzene solution, and a carrier was added. A transport layer forming solution was prepared. This solution was applied onto the same carrier generation layer as in Example 1 and dried at 80°C for 1 hour to produce an electrophotographic photoreceptor (sample No. 5) of the present invention having a carrier transport layer with a thickness of 13 microns. did. 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, as a styryl compound, exemplified compound (B-
An electrophotographic photoreceptor (Sample No. 6) of the present invention having a carrier transport layer having a thickness of 13 microns was prepared in the same manner as in Example 5, except that Sample No. 14) was used. 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 solution for forming a carrier transport layer that does not contain the styryl compound 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 15 g of exemplified styryl compound (B-9) and 15 g of polycarbonate resin were mixed in 1,2-dichloroethane.
In addition to 100 ml, a carrier transport layer forming solution containing no aromatic amino compound was prepared. 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. 2) was prepared. Comparative Example 3 A carrier transport layer forming solution with a thickness of 12 microns was prepared in the same manner as in Comparative Example 1, except that 0.3 g of 2,4,7-trinitro-9-fluorenone was added as a Lewis acid. A carrier transport layer was formed and a comparative electrophotographic photoreceptor (comparative sample No.
3) was created. Sample No. 1 obtained in each of the above Examples and Comparative Examples
~ No. 6 and comparative samples No. 1 to No. 3 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. Immediately after this charging operation, the charged potential Vo (V) on the surface of the photosensitive layer and the amount of irradiation light E1/2 (1X·sec) required to attenuate this charged potential Vo to 1/2 were measured. The results are shown in Table 1.

[Table] In addition, samples No. 1 and No. 5 and comparative samples No. 1 and No. 3 were irradiated with light from an ultra-high pressure mercury lamp "SHL-100UV" (manufactured by Tokyo Shibaura Electric Co., Ltd.) for 30 seconds at a distance of 5 cm. When similar measurements were carried out for sample No. 1, Vo=-775 (V),
E1/2=2.9 (1X・sec) Also, in sample No. 5, Vo=-
840 (V), E1/2 = 2.6 (1x sec), and there was little change. On the other hand, comparative sample No. 1 has Vo=-825
(V), E1/2=6.5 (1x・sec) Also, comparison sample No. 3 is
The sensitivity decreased significantly with Vo=-785 (V) and E1/2=6.1 (1x·sec), demonstrating the stability of the sample photoreceptor of the present invention against ultraviolet rays. Furthermore, the aforementioned samples No. 1 to No. 6 and comparative samples No. 1 to
No. 3 was attached to a dry type electronic copying machine U-BiX2000R (manufactured by Konishiroku Photo Industry Co., Ltd.) to perform continuous copying, and the black paper potential Vb (V) and white paper potential Vw (V) at an exposure aperture value of 2.5 were obtained. Electrostatic Voltmeter Model 144D-1D (Monroe Electronics
(manufactured by Incorporated) and was measured 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 Vo (V), and the lower row (in parentheses) shows the white paper potential Vw (V). In addition, the amount of fluctuation increases,
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 photoreceptor No. 3, the amount of variation in both of the above potentials was large, causing significant background fog in the image after 5,000 copies, and in photoreceptor No. 2, a comparative sample, the image density was significantly reduced due to a decrease in black paper potential. is 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 consisting 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 formula [B] and a styryl compound represented by the following general formula [B]. General formula [A]: [In the formula, 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; /or R ₃ and R ₄ may jointly form a nitrogen-containing heterocycle. 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. X represents an oxygen atom, a sulfur atom, [Formula] [Formula] [Formula] (CH=CH)n 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 base
R ₅ and R ₆ may jointly form a carbocyclic group or a heterocyclic group, and n is 1 or 2. ] General formula [B]: [In the formula, R ₁ and R ₂ represent a substituted or unsubstituted phenyl group, and a phenyl group, an alkoxy group, or an alkyl group is used as the substituent. R ₃ is substituted/unsubstituted phenyl group, naphthyl group,
It represents an anthryl group, a fluorenyl group, or a heterocyclic group, and as a substituent, an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, or a phenyl group is used. R ₄ represents hydrogen, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. 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.