JPS6135546B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electrophotographic photoreceptor, and more particularly to a novel electrophotographic photoreceptor having a photosensitive layer containing an organic photoconductive compound as a main component. Conventionally, as electrophotographic photoreceptors, those having a photosensitive layer containing as a main component an inorganic photoconductor such as selenium, zinc oxide, or cadmium sulfide are widely known. However, these are not necessarily satisfactory in terms of properties such as thermal stability and durability, and furthermore, there are problems in production and handling due to toxicity. On the other hand, electrophotographic photoreceptors having a photosensitive layer containing an organic photoconductive compound as a main component are relatively easy to manufacture, inexpensive, easy to handle, and generally selenium photoreceptors, etc. It has many advantages, such as superior thermal stability, and has attracted a lot of attention in recent years. Poly-N-vinylcarbazole is the most well-known such organic photoconductive compound, and 2.
4,7-trinitro-9-fluorenone, etc.
Electrophotographic photoreceptors having a photosensitive layer mainly composed of a charge transfer complex formed from sulfuric acid have already been put into practical use. On the other hand, electrophotographic photoreceptors are known that have a functionally dispersed photosensitive layer of a laminated type or a dispersion type in which the carrier generation function and the carrier transport function of the photoconductor are respectively shared by separate substances. An electrophotographic photoreceptor having a photosensitive layer combining a carrier generation layer made of a thin layer of amorphous selenium and a carrier transport layer made of poly-N-vinylcarbazole has been put into practical use. However, since poly-N-vinylcarbazole lacks flexibility, its coating is hard and brittle, and is prone to cracking and peeling. Therefore, electrophotographic photoreceptors made using it have poor durability. In addition, if a plasticizer is added to improve this drawback, the residual potential will increase when subjected to the electrophotographic process, and as it is repeatedly used, the residual potential will accumulate, gradually causing fog in the copied image. It has some drawbacks. In addition, since low molecular weight organic photoconductive compounds generally do not have film-forming ability, they are used in combination with any binder, and therefore, by selecting the type and composition ratio of the binder used, it is possible to form a film. Although it is preferable in that the physical properties or electrophotographic properties can be controlled to a certain extent, there are only a limited number of organic photoconductive compounds that have high compatibility with binders, and in reality it is difficult to use in electrophotography. The reality is that there are not many materials that can be used to construct the photosensitive layer of a photoreceptor. For example, 2,5-bis(p-diethylaminophenyl)-1,3,4-oxadiazole described in U.S. Pat. No. 3,189,447 is usually preferred as a material for the photosensitive layer of an electrophotographic photoreceptor. Since it has low compatibility with the binder used, for example, if it is mixed with a binder such as polyester or polycarbonate in the ratio required to obtain favorable electrophotographic properties to form a photosensitive layer, Oxadiazole crystals begin to precipitate at temperatures of 50° C. or higher, which has the disadvantage that electrophotographic properties such as charge retention and sensitivity deteriorate. On the other hand, the diarylalkane derivatives described in U.S. Pat. When used in the construction of a photosensitive layer of a repeat transfer type electrophotographic photoreceptor in which exposure is repeated, the sensitivity of the photosensitive layer gradually decreases and the residual potential increases, resulting in poor durability. . The reality is that an organic photoconductive compound that has practically preferable characteristics for producing an electrophotographic photoreceptor has not yet been found. An object of the present invention is to provide an electrophotographic photoreceptor containing a novel organic photoconductive compound that has excellent compatibility with a binder, is stable against heat and light, and has excellent carrier transport ability. be. Still another object of the present invention is to provide an electrophotographic photoreceptor with high sensitivity and low residual potential. Another object of the present invention is to provide an electrophotographic photoreceptor that is highly durable and has stable characteristics over a long period of time, with little fatigue deterioration due to repeated use of charging, exposure, development, and transfer steps. . As a result of intensive research to achieve the above object, the present inventors have discovered that the object can be achieved by using a specific hydrazone derivative as a constituent material of the photosensitive layer of an electrophotographic photoreceptor, and have developed the present invention. It is completed. The above object is achieved by providing a photosensitive layer containing a hydrazone derivative represented by the following general formula [] on a conductive support. General formula [] However, R ₁ in the formula represents a substituted/unsubstituted aryl group, a substituted/unsubstituted heterocyclic group, and preferred aryl groups include a phenyl group, a naphthyl group,
Preferred heterocyclic groups of anthryl group include furyl group, thienyl group, indolyl group, benzofuryl group, benzothienyl group, and carbazolyl group. Examples of these substituents include substituted amino groups such as alkyl groups, alkoxy groups, dialkylamino groups, diarylamino groups, and alkylaryl amino groups, phenyl groups, naphthyl groups, hydroxyl groups, and halogen atoms. 〓〓〓〓〓
R ₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and a preferable alkyl group is an alkyl group having 1 to 8 carbon atoms, and a preferable aryl group is phenyl. group, represents a naphthyl group. Preferred examples of these substituents include substituted amino groups such as an alkyl group, an alkoxy group, a dialkylamino group, a diarylamino group, and an acylaryl amino group, a hydroxyl group, and a halogen atom. X represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a cyano group, and a substituted amino group such as a dialkylamino group, a diarylamino group, or an alkylarylamino group. n represents an integer of 0 or 1. That is, in the present invention, by using the hydrazone derivative represented by the general formula [] as a photoconductive substance of an electrophotographic photoreceptor, and by utilizing only the excellent carrier transport ability of the hydrazone derivative of the present invention, By using it as a carrier transport material in a so-called functionally separated electrophotographic photoreceptor, in which carrier generation and transport are performed using separate materials, the film has excellent physical properties, charge retention ability,
It is possible to create an electrophotographic photoreceptor that has excellent electrophotographic properties such as sensitivity and residual potential, exhibits little fatigue deterioration even after repeated use, and exhibits stable properties against heat and light. can.
Further, the hydrazone derivative used in the present invention is represented by the general formula []. Hydrazone derivatives may be used alone or in combination of two or more, and may also be used in combination with other photoconductive substances. Specific examples of the hydrazone derivatives represented by the general formula [] that are effective in the present invention include those having the following structural formula, but the hydrazone derivatives of the present invention are not limited thereto. . 〓〓〓〓〓
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The above hydrazone derivatives can be easily synthesized by known methods. For example, by condensing a 1-amino-1,2,3,4-tetrahydroquinoline derivative represented by the general formula [] with a carbonyl compound [] in a solvent such as alcohol, optionally in the presence of an acid catalyst. , a hydrazone derivative represented by the general formula [ ] can be synthesized. 〓〓〓〓〓
Here, R ₁ , R ₂ , X, and n are the same as those shown in the general formula []. Next, a typical method for synthesizing the hydrazone derivative of the present invention will be specifically described. Synthesis Example 1 (Synthesis of Exemplary Compound K-(3)) 1-Amino-1,2,3,4-tetrahydroquinoline (Zhur.Obshchei.Khim., 29 , 1949-53
(1959)) and 1.8 g (0.01 mole) of diethylaminobenzaldehyde in ethanol.
The mixture was dissolved in 40 ml of water, 5 ml of acetic acid was added thereto, and the mixture was heated under reflux for 1 hour. After cooling, the precipitated crystals were collected and recrystallized from ethanol. 2.8 g (93.3%) of the desired hydrazone compound was obtained. Melting point: 129-130°C Synthesis Example 2 (Exemplified Compound K-(9)) 1.5 g (0.01 mole) of 1-amino-1,2,3,4-tetrahydroquinoline and P-(N・N-di-P
-tolylamino)-benzaldehyde 3.0g
(0.01 mole) in 30 ml of isopropanol,
6 ml of acetic acid was added and the mixture was heated under reflux for 1.5 hours. After cooling, the precipitated crystals were collected and recrystallized from a toluene-isopropanol mixed solvent to obtain 3.4 g of the desired product.
(79.0%). Melting point: 195-196°C Synthesis Example 3 (Exemplary Compound K-(26)) 1-amino-1,2,3,4-tetrahydroquinoline 1.5g (0.01mole) and N-phenyl-3-
Dissolve 2.7 g (0.01 mole) of carbazole aldehyde in 30 ml of isopropanol, add 6 ml of acetic acid,
The mixture was heated under reflux for 1.5 hours. After cooling, the precipitated crystals were collected and separated and purified by silica gel chromatography to obtain 2.5 g (62.5%) of the desired product. melting point
84.5-86℃) Synthesis Example 4 (Exemplary Compound K-(25)) 1-Amino-1,2,3,4-tetrahydroquinoline 1.5g (0.01mole) and N-ethyl-3-carbazolaldehyde 2.2g (0.01mole) mole) was dissolved in 50 ml of ethanol, 5 ml of acetic acid was added, and the mixture was heated under reflux for 3 hours. After cooling, the precipitated crystals were collected and separated and purified by silica gel chromatography to obtain 2.8 g (79.3%) of the desired product. Melting point: 115-117°C The hydrazone derivative of the present invention has a
Since it has almost no photosensitivity, it is necessary to perform sensitization treatment when exposing it to visible light. Various methods have been proposed for sensitizing organic photoconductive compounds. The first method is to add an organic dye and perform spectral sensitization (dye sensitization). The second method is to sensitize by forming a charge transfer complex. Since the hydrazone derivative of the present invention is an electron-donating substance, in this case it is preferably used in combination with an electron-accepting substance. The third method is
This method utilizes only the carrier transport ability of the hydrazone derivative of the present invention and combines it with other organic dyes, pigments, or inorganic photoconductors or other carrier-generating substances having carrier-generating ability to produce a functionally separated photoreceptor. The hydrazone derivative of the present invention exhibits good effects with any of the above-mentioned sensitization methods, and any suitable method may be selected depending on the purpose. Next, typical examples of organic dyes for spectral sensitization used in the present invention are listed. (A-1) Triphenylmethane pigments such as methyl violet, crystal violet, and malachite green. (A-2) Xanthene pigments such as erythrosine and rose bengal. (A-3) Thiazine dyes such as methylene blue and methylene green. (A-4) Oxazine dyes such as Capri Blue and Meldora Blue. (A-5) Cyanine pigments such as thiacyanin and oxacyanin. 〓〓〓〓〓
(A-6) Styryl dyes such as P-dimethylaminostyrylquinoline. (A-7) Pyrylium salt pigments such as pyrylium salt, thiapyrylium salt, benzopyrylium salt, and benzothiapyryllium salt. (A-8) 3,3′-dicarbazolylmethane dye. These can be used as carrier generating substances. In addition to the above-mentioned dyes, the following are also used as carrier generating substances. (B-1) Azo dyes such as monoazo dyes, disazo dyes, and trisazo dyes. (B-2) Perylene dyes such as perylenic anhydride and perylenic acid imide. (B-3) Indigo pigments such as indigo and thioindigo. (B-4) Polycyclic quinones such as anthraquinone, pyrenequinone and furapanthrones. (B-5) Quinacridone dye. (B-6) Bisbenzimidazole dye. (B-7) Indanthrone dye. (B-8) Squarelillium pigment. (B-9) Phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine. (B‐10) Selenium, selenium alloys. (B-11) Inorganic photoconductors such as CdS, CdSe, and amorphous silicon. (B-12) Pyrylium salt dye, eutectic complex formed from thiapyrylium salt dye and polycarbonate. As the electron-accepting substance that can form a charge transfer complex with the hydrazone derivative of the present invention, 2, 4, 7-
Lewis acids such as trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, chloranil, and tetracyanoquinodimethane are used. Further, chemical sensitizers can also be effectively used in the photoreceptor of the present invention. Since the hydrazone derivative used in the present invention does not have the ability to form a film by itself, a photosensitive layer is formed by combining various binders. Any binder can be used here, 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. (C-1) Polycarbonate (C-2) Polyester (C-3) Methacrylic resin (C-4) Acrylic resin (C-5) Polyvinyl chloride (C-6) Polyvinylidene chloride (C-7) Polystyrene (C -8) Polyvinyl acetate (C-9) Styrene copolymer resin (e.g. styrene-
butadiene copolymer, etc.) (C-10) Acrylonitrile copolymer resin (e.g. vinylidene chloride-acrylonitrile copolymer, etc.) (C-11) Vinyl chloride-vinyl acetate copolymer (C-12) Vinyl chloride-vinyl acetate -Maleic anhydride copolymer (C-13) Silicone resin (C-14) Silicone-alkyd resin (C-15) Phenol resin (e.g. phenol-formaldehyde resin, m-cresol-formaldehyde resin, etc.) (C-16) Styrene-alkyd resin (C-17) Poly-N-vinylcarbazole These binders can be used alone or as a mixture of two or more. As shown in FIGS. 1 and 2, the photoreceptor of the present invention comprises a conductive support 1, a carrier generating layer 2 containing a carrier generating substance as a main component, and a carrier transporting substance containing the hydrazone derivative of the present invention. A photosensitive layer 4 made of a laminate with a carrier transport layer 3 containing as a main component is provided. As shown in FIGS. 3 and 4, this photosensitive layer 4 may be provided on the conductive support 1 with an intermediate layer 5 interposed therebetween. When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having the best electrophotographic properties can be obtained. Further, in the present invention, as shown in FIGS. 5 and 6, in the layer 6 mainly composed of a carrier transport substance,
A photosensitive layer 4 in which a particulate carrier-generating substance 7 is dispersed may be provided on the conductive support 1 directly or via an intermediate layer 5. Furthermore, preferable results can be obtained by adding a sensitizing dye or a Lewis acid to the carrier transporting substance and forming a single photosensitive layer 4 in the same manner as shown in FIGS. 5 and 6, without using the carrier-generating substance. 〓〓
is obtained. Here, when the photosensitive layer 4 has a two-layer structure, which of the carrier generation layer 2 and the carrier transport layer 3 is to be the upper layer is determined depending on whether the charging polarity is positive or negative. That is, when forming a negatively charged photosensitive layer, it is advantageous to use the carrier transport layer 3 as an upper layer, since the hydrazone derivative in the carrier transport layer 3 is a substance that has a high transport ability for holes. Because there is. The carrier generation layer 2 constituting the two-layered photosensitive layer 4 can be formed directly on the conductive support 1 or the carrier transport layer 3 or by providing an intermediate layer such as an adhesive layer or a barrier layer as necessary. can be formed by the following method. (m-1) Vacuum deposition method (m-2) Method of applying a solution of a carrier-generating substance dissolved in a suitable solvent (m-3) A method of applying a solution of a carrier-generating substance dissolved in a suitable solvent (m-3) A method of applying a solution of a carrier-generating substance dissolved in a suitable solvent in a dispersion medium using a ball mill, homomixer, etc. into fine particles,
A method of applying a dispersion obtained by mixing and dispersing with a binder as necessary. The thickness of the carrier generation layer 2 thus formed is preferably 0.01 to 5 microns, more preferably 0.05 microns. ~3 microns. Further, the thickness of the carrier transport layer 3 can be changed as necessary, but it is usually preferably 5 to 30 microns. The composition ratio in this carrier transport layer 3 is 0.8 to 10 parts by weight of the binder to 1 part by weight of the carrier transport material whose main component is the hydrazone derivative described above.
It is preferable to use the binder in parts by weight, but when forming the photosensitive layer 4 in which a fine powder carrier-generating substance is dispersed, the binder is used in an amount of 5 parts by weight or less per 1 part by weight of the carrier-generating substance. It is preferable. Further, when the carrier generating layer 2 is configured as a dispersed type layer using a binder, it is preferable to use the binder in an amount of 5 parts by weight or less per 1 part by weight of the carrier generating substance. The conductive support 1 used in the construction of the electrophotographic photoreceptor of the present invention may be a metal plate, a metal drum, or a conductive compound such as a conductive polymer indium oxide, or a metal thin film such as aluminum, palladium, or gold. Paper, plastic film, etc. that have been made conductive by coating, vapor depositing, or laminating a layer are used. For the intermediate layer 5 such as an adhesive layer or barrier layer, in addition to the polymer used as the binder, an organic polymer material such as polyvinyl alcohol, vinyl acetate, ethyl cellulose, carboxymethyl cellulose, or aluminum oxide may be used. It will be done. The electrophotographic photoreceptor of the present invention has the above-described structure, and as is clear from the examples described later, it has excellent charging characteristics, sensitivity characteristics, and image forming characteristics.
In particular, even when subjected to repeated transfer electrophotography, fatigue deterioration is small and durability is excellent. Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited thereto. Example 1 Selenium was evaporated onto a conductive support consisting of a polyester film laminated with aluminum foil to form a carrier generating layer with a thickness of 0.5 microns. Thereon, 6 parts by weight of exemplary compound K-(1) and 10 parts by weight of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Chemicals) were added to 1,2-dichloroethane.
The electrophotographic photoreceptor of the present invention was prepared by dissolving this solution in 90 parts by weight and applying the solution to a dry film thickness of 11 microns to form a carrier transport layer. The electrophotographic properties of this electrophotographic photoreceptor were measured by a dynamic method using an electrostatic copying paper tester "SP-428" (manufactured by Kawaguchi Electric Seisakusho). That is, the surface of the photosensitive layer of the photoreceptor is charged with a voltage of -
The surface potential V _A when charged at 6 KV for 5 seconds is then irradiated with light from a tungsten lamp so that the illuminance on the photoreceptor surface is 35 lux, and the surface potential V _A is attenuated by half. Surface potential (residual potential) V after irradiation with exposure amount (half-reduced exposure amount E1/2 (lux・sec) and 30 lux・sec)
We calculated _R for each. In addition, similar measurements were repeated 100 times.
The results are shown in Table 1. Comparative Example 1 A hydrazone derivative represented by the following structural formula was used as a carrier transport material.
A comparative photoreceptor was prepared in the same manner as in Example 1, and
Similar measurements were made. The results are shown in Table 1.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention of Example 1 was significantly superior to the photoreceptor of Comparative Example 1 in terms of sensitivity, residual potential characteristics, and repetition stability. It is. Example 2 Vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF" was deposited on a conductive support made of a polyester film laminated with aluminum foil.
-10'' (manufactured by Sekisui Chemical Co., Ltd.) with a thickness of 0.05 microns, and on top of that is dibromoanthrone ``Monolite Red 2Y'' (CI No. 59300 I.
CI) was vapor-deposited to form a carrier generation layer with a thickness of 0.5 microns. Furthermore, 6 parts by weight of exemplary compound K-(4) and 10 parts by weight of polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals) were added to 90 parts by weight of 1,2-dichloroethane.
A carrier transport layer was formed by coating a solution dissolved in parts by weight so that the film thickness after drying was 11 microns, thereby producing an electrophotographic photoreceptor of the present invention. The same measurements as in Example 1 were performed on this photoreceptor. The results are shown in Table 2. Comparative Example 2 A comparative photoreceptor was prepared in the same manner as in Example 1, except that a hydrazone derivative represented by the following structural formula was used as a carrier transport material. The same measurements as in Example 1 were carried out on this photoreceptor, and the results shown in Table 2 were obtained.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention of Example 2 is significantly superior to the comparative photoreceptor in terms of sensitivity, residual potential characteristics, and repetition stability. Example 3 On the conductive support provided with the intermediate layer used in Example 2, 1 part by weight of a bisazo pigment represented by the following structural formula was mixed with tetradiamine, 2-butylamine, and tetrahydrofuran in a ratio of 1.2:1.0:2.2. It was dissolved in 140 parts by weight of the mixed liquid, and this solution was applied to a dry film thickness of 0.3 microns to form a carrier generation layer. 〓〓〓〓〓
Next, a solution obtained by dissolving 6 parts by weight of Exemplified Compound K-(3) and 10 parts by weight of polycarbonate "Iupilon S-1000" (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 90 parts by weight of 1,2-dichloroethane was dried to form a membrane. A carrier transport layer was formed by coating to a thickness of 13 microns to produce an electrophotographic photoreceptor of the present invention. The same measurements as in Example 1 were performed on this photoreceptor. The results are shown in Table 3. Furthermore, FIG. 7 shows the changes in V _A and V _R when measurements were repeated 5000 times. Comparative Example 3 A comparative photoreceptor was prepared in the same manner as in Example 3, except that a hydrazone derivative represented by the following structural formula was used as the carrier transport material. When this photoreceptor was measured in the same manner as in Example 3, the results shown in Table 3 and FIG. 7 were obtained.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention of Example 3 is significantly superior to the comparative photoreceptor, especially in terms of repeated stability of residual potential characteristics. Example 4 When the electrophotographic photoreceptor of the present invention according to Example 3 was installed in an electrophotographic copying machine "U-Bix2000R" (manufactured by Konishiroku Photo Industry Co., Ltd.) and an image was copied, it was found that the image was faithful to the original image, and the contrast and A clear copy image with excellent gradation and no fogging was obtained. Even after repeating this process 10,000 times, the same copy image as the initial one could be obtained without any change. Comparative Example 4 When an image was copied in the same manner as in Example 4 using the photoreceptor of Comparative Example 4, initially,
A similar clear copy image was obtained, but after around 500 copies, the fog gradually became noticeable, and by 1000 copies, a clear copy image could no longer be obtained.
It was found that it was extremely inferior as an electrophotographic photoreceptor. Examples 5 to 10 Exemplary compounds K-(8) as carrier transport substances,
The electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 3 except that K-(14), K-(21), K-(27), K-(36) and K-(42) were used. Created. The properties of these electrophotographic photoreceptors were as shown in Table 4.

[Table] 〓〓〓〓〓

[Table] All had good acceptance potential, sensitivity, and residual potential characteristics. Example 11 Aluminum was deposited on a polyester film, and then a 0.5 micron thick intermediate layer made of polyester "Vylon-200" (manufactured by Toyobo Co., Ltd.) was provided. Further, as a carrier generating substance, 1 part by weight of a bisazo pigment represented by the following structural formula and 1 part by weight of a polycarbonate resin "Panlite L-1250" (manufactured by Teijin Chemicals) were added to 140 parts of 1,2-dichloroethane.
A carrier-generating layer was formed by applying a solution dispersed in parts by weight so that the film thickness after drying was 1 micron. Furthermore, as a carrier transport substance, a solution containing 6 parts by weight of Exemplary Compound K-(25) and 10 parts by weight of methacrylate resin "Acripet" (manufactured by Mitsubishi Rayon Co., Ltd.) dissolved in 90 parts by weight of 1,2-dichloroethane was added. An electrophotographic photoreceptor of the present invention was prepared by applying the following to a dry film thickness of 12 microns. The same measurements as in Example 1 were performed on this electrophotographic photoreceptor. Further, it was installed in an electrophotographic copying machine "U-Bix2000R", and charging, exposure, and cleaning were repeated 10,000 times, and the acceptance potential, sensitivity, and residual potential were measured again to examine the degree of fatigue deterioration due to charging and exposure. The results are shown in Table 5. Comparative Example 5 Example 11 except that a hydrazone derivative represented by the following structural formula was used as a carrier transport substance.
A comparative photoreceptor was created using the same behavior. Regarding this comparative photoreceptor, the same measurements as in Example 11 were carried out, and the results shown in Table 5 were obtained. 〓〓〓〓〓

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention is extremely excellent in sensitivity, residual potential characteristics, and repeated stability. Example 12 Aluminum was deposited on a polyester film, and 1 part by weight of a bisazo compound represented by the following structural formula was well dispersed in 140 parts by weight of 1,2-dichloroethane, and the film thickness after drying was 0.4 microns. A carrier generation layer was formed by applying the coating to form a carrier generation layer. On top of that, 6 parts by weight of exemplified compound K-(26) and polyester "Vylon" were added as a carrier transport material.
The electrophotographic photoreceptor of the present invention was prepared by dissolving 10 parts by weight of "200" (manufactured by Toyobo Co., Ltd.) in 90 parts by weight of 1,2-dichloroethane and applying the solution to a dry film thickness of 12 microns. Created. The sensitivity of this electrophotographic photoreceptor, E1/2, was 2.8 lux·sec, and the residual potential _VR was 0V. This photoreceptor is also equipped with an ultra-high-pressure mercury lamp (SHL-).
After irradiating with 100U, V'' (manufactured by Toshiba) light for 10 minutes,
When the same measurement was performed again, E1/2 = 3.1 lux·sec V _R =0V, and almost no change in characteristics was observed. Comparative Example 6 Example 12 except that a hydrazone derivative represented by the following structural formula was used as a carrier transport substance.
A comparative photoreceptor was prepared in the same manner as described above. The sensitivity E1/2 of this comparative photoreceptor was 4.1 lux·sec, and the residual potential V _R was -30V. Further, when ultraviolet rays were irradiated in the same manner as in Example 12, E1/2 = 8.2 lux·sec and V _R = -85V. From the above results, it can be seen that the electrophotographic photoreceptor of the present invention is extremely stable against light. Example 13 Aluminum was deposited on a polyester film, and then a perylene pigment represented by the following structural formula was deposited as a carrier generating substance to form a carrier generating layer having a thickness of 0.5 microns. 〓〓〓〓〓
In addition, exemplified compound K is added as a carrier transport substance.
- (22) 6 parts by weight and polyester resin "Vylon"
200 (manufactured by Toyobo Co., Ltd.) in 90 parts by weight of 1,2-dichloroethane to form a carrier transport layer such that the film thickness after drying was 15 microns. An electrophotographic photoreceptor was created. The initial characteristics of this electrophotographic photoreceptor were measured in the same manner as in Example 1, and it was found that V _A =-
1245V E1/2=3.9 lux·sec, V _R =-5V. In addition, this photoconductor was left in a constant temperature bath at 70°C for 10 hours, and after cooling, the same measurement was performed again _.
=-1210V E1/24.0 lux・sec V _R =-5V. Even when left under high temperature, the carrier transport substance does not precipitate due to heat, and changes in properties are extremely small, indicating that the electrophotographic photoreceptor of the present invention has excellent heat resistance. . Comparative Example 7 A comparative photoreceptor was prepared in the same manner as in Example 13, except that the following oxadiazole derivative was used as the carrier transport material. When this comparative photoreceptor was measured in the same manner as in Example 13, the initial characteristics were V _A = -1325V.
E1/2 = 4.5 lux・sec, V _R = -10V, but when left under high temperature, oxadiazole precipitates on the surface of the carrier transport layer, and it can no longer be used as an electrophotographic photoreceptor. It was hot. Example 14 A 0.1 micron thick intermediate layer made of polyester "Vylon 200" (manufactured by Toyobo Co., Ltd.) was provided on a conductive support made of polyester film laminated with aluminum foil. On top of that, 1 part by weight of 4-(p-dimethylaminophenyl)-2,6-diphenylthiopyrylium perchlorate was dissolved in 130 parts by weight of dichloromethane, and polycarbonate "Iupilon S-1000" (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved. ) and 6 parts by weight of exemplified compound K-(3) were added and dissolved, and the solution was stirred well and applied to form a photosensitive layer so that the film thickness after drying was 12 microns. An electrophotographic photoreceptor was created. When this photoreceptor was measured in the same manner as in Example 1, the results shown in Table 6 were obtained.

[Table] As is clear from the above results, the electrophotographic photoreceptor of the present invention is excellent in various properties such as charging characteristics, sensitivity, and residual potential, and is also extremely excellent in repeated stability.

[Brief explanation of the drawing]

FIGS. 1 to 6 each represent a cross-sectional view showing an example of the functional structure of the electrophotographic photoreceptor of the present invention. 1... Conductive support, 2... Carrier generation layer,
3... Carrier transport layer, 4... Photosensitive layer, 5... Intermediate layer, 6... Layer containing a carrier transport substance, 7
...Carrier generating substance. FIG. 7 shows V _A in Example 3 and Comparative Example 3.
and FIG. 3 is a diagram of changes in V _R . 〓〓〓〓〓

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer containing a hydrazone derivative represented by the following general formula [] on a conductive support. General formula [] (In the formula, R ₁ represents a substituted/unsubstituted aryl group, a substituted/unsubstituted heterocyclic group, and R ₂ represents a hydrogen atom, a substituted/unsubstituted alkyl group, a substituted/unsubstituted aryl group, X is a hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group,
Represents a cyano group, and n is an integer of 0 or 1. ) 2. The electrophotographic photoreceptor is a functionally separated electrophotographic photoreceptor comprising a photosensitive layer formed by combining a carrier generating substance and a carrier transporting substance on a conductive support. electrophotographic photoreceptor. 3. The electrophotographic photoreceptor according to claim 1 or 2, wherein the photosensitive layer is constituted by a laminate of a carrier generation layer and a carrier transport layer. 4. The electrophotographic photoreceptor according to claim 1 or 2, wherein the photosensitive layer has a carrier-generating substance dispersed in a carrier transport layer.