JPH0325777B2 - - Google Patents

Description

[Detailed description of the invention]

1. Industrial Application Field The present invention relates to a photoreceptor, particularly an electrophotographic photoreceptor. 2. Prior Art In general, with the exception of a few substances such as amorphous selenium, it is difficult to form a film on the surface of substances that absorb visible light and generate carriers. It has the disadvantage of poor retention of a given charge. On the contrary, materials that have excellent film-forming ability and can retain a charge of 500 V or more for a long time with a thickness of about 10 μm generally have the disadvantage of not having sufficient photoconductivity due to absorption of visible light. have. For this reason, as shown in FIG. 1, a carrier generation layer 2 containing a substance that absorbs visible light and generates charge carriers is provided on the substrate 1, and whether the charge carriers generated in this carrier generation layer are positive or negative is It has been proposed to provide a laminate 4 with a carrier transport amount 3 that transports one or both of the two, and to configure the photosensitive layer with this laminate. In this way, by assigning charge carrier generation and transport to separate materials, the range of material selection is widened and the properties required in the electrophotographic process, such as charge retention, surface strength, and visible It has become possible to improve sensitivity to light and stability during repeated use. However, an excellent electrophotographic photoreceptor that is easy to manufacture, has sufficient electrophotographic properties, and is stable against environmental changes has not been known to date. For example, when the carrier generation layer is composed of amorphous selenium, it is manufactured using a vacuum evaporation apparatus while controlling the degree of vacuum and the temperature of the evaporation source. It is extremely difficult to obtain a stable deposited film. Moreover, since amorphous selenium is thermally unstable, crystallization progresses at temperatures of 50° C. or higher, and it no longer functions as a carrier generation layer. Therefore, especially in an electrophotographic photoreceptor in which a carrier generation layer made of amorphous selenium is provided on a conductive support and a carrier transport layer is coated thereon, the drying temperature of the carrier transport layer after coating is set at 50°C. ℃ or below, making economical production nearly impossible, and the produced electrophotographic photoreceptors had problems with their retention. In addition, when the carrier generation layer is composed of a perylene pigment, if a vacuum deposition method is used, it is difficult to obtain a uniform deposited film in the width direction and length direction, as in the case of amorphous selenium. The deposited film thus obtained has a disadvantage in that it is difficult to handle when applying a carrier transport layer because of its poor scratchability.
Although there is a description in U.S. Patent No. 3,904,407 that a perylene pigment is dispersed in a binder resin to form a carrier generation layer, it has not been put to practical use because the electrophotographic properties such as sensitivity are significantly inferior to vapor deposition methods. It has not been. 2. Description of the Related Art An electrophotographic photoreceptor is known that uses an organic pigment as a carrier generating substance in the carrier generating layer and has a carrier generating layer made of a vapor-deposited film of the organic pigment. Since this carrier generation layer is a densely deposited organic pigment free of impurities, it is preferable in that relatively high photosensitivity can be obtained even if it is a thin layer. However, its production requires a large continuous vapor deposition device, and it is extremely difficult to control the film thickness, and it is difficult to form a carrier generation layer with a uniform thickness over the entire surface of the conductive support. is difficult and therefore very costly.
Furthermore, the vapor-deposited organic pigment film has low adhesion to the support and has extremely low strength, so it is prone to scratches and other defects. subject to many restrictions. Moreover, in many cases it is effective to add appropriate additives to improve the properties of the organic pigment, but with the vapor deposition method, there are limits to the type and amount of substances that can be mixed in, and it is difficult to mix them uniformly. It is difficult and almost impossible to improve the characteristics. Due to the above-mentioned circumstances, to date, no electrophotographic photoreceptor has been provided that uses organic pigments and has actually good characteristics. In view of the above-mentioned circumstances, the present applicant has developed a technology that is capable of consistently forming clear copy images with high sensitivity to visible light, and that is uniform over a long length, inexpensive, and that cannot be obtained using vacuum evaporation methods. An electrophotographic photoreceptor having a carrier generation layer which can be stably produced and has excellent scratch resistance has already been proposed in Japanese Patent Application No. 34539/1983. In this prior invention, the above-mentioned excellent effects are exhibited by dispersing a polycyclic quinone pigment such as anthoanthrone in the form of photoconductive particles in polycarbonate. On the other hand, the present applicant has used a purified pigment obtained by sublimation-purifying an organic pigment with sublimation property as an electrophotographic photoreceptor that has extremely excellent properties not only in electrophotographic properties but also in manufacturing and use. An electrophotographic photoreceptor in which a photosensitive layer is constituted by a pigment-containing layer obtained by applying a liquid containing the same has already been proposed in Japanese Patent Application No. 143,699/1983. The present inventor conducted studies to improve these prior inventions, and as a result, discovered the following problems. That is, if the above-mentioned commercially available polycyclic quinone pigment is used as a carrier generating substance as it is, the crystal shape of the pigment is not well-organized and a large amount of additives act as impurities, resulting in insufficient sensitivity. In addition, when a large number of copies are repeatedly made, the potential of the background portion of the image (blank paper potential) may rise and fog may occur. In addition, the above-mentioned sublimation purification makes it possible to grow crystals with high purity, resulting in higher sensitivity than when conventional pigments are used as is. Therefore, simply dispersing it in an organic solvent will only yield particles with a large particle size. Moreover, since pigments such as the above-mentioned anthrone are generally not soluble in solvents, when such a pigment dispersion is applied to form a carrier generation layer, the particle size of the photoconductive particles (pigment particles) may be affected. I found out that I can put it away.
In other words, the dispersibility of the pigment particles is not very good and the stability of the coating solution tends to deteriorate, and as shown in an enlarged view in FIG. Following this, convex portions 6 are also formed on the surface of the carrier transport layer 3, which deteriorates the smoothness of the surface of the photoreceptor. As a result, when the entire surface of the photoreceptor is charged during use, discharge 7 occurs at the position of the convex portion 6, and local discharge breakdown is likely to occur. In addition, toner particles 8 adhere to the convex portions 6 and remain as they are, causing a so-called toner filming phenomenon, which causes black spots and the like on images. In the phenomenon shown in FIG. 2, the carrier generation layer 2 is formed to be very thin, several micrometers or less, to ensure sufficient electron mobility, and is packed with pigment particles closest to each other to improve sensitivity. It will be understood that the influence of the particle size of the pigment particles 5 and its variation is likely to occur on the surface of the photoreceptor, and the above-mentioned convex portions 6 are likely to be formed. Additionally, the present inventors have discovered that in conventional photoreceptors, sufficient studies have not been made on the combination of carrier-generating substances and carrier-transporting substances. I found out that it wasn't. Furthermore, it was found that the sensitivity of general photoreceptors decreases at low temperatures, causing fog in images. 3. Object of the invention The object of the invention is to provide a photoreceptor that exhibits high sensitivity, can be manufactured uniformly and stably, has excellent surface smoothness, and has good durability without local discharge destruction or toner filming. It's about doing. Another object of the present invention is to improve the dispersibility and dispersion stability of a coating solution, and to obtain a coating-type photoreceptor that is easy to manufacture and obtainable at low cost (in particular, a photoreceptor having a laminated structure of a carrier generation layer and a carrier transport layer). An object of the present invention is to provide a functionally separated photoreceptor having layers. Another object of the present invention is to provide a photoreceptor with high sensitivity, excellent color sensitivity, and good operational stability during repeated use by specifying a combination of a carrier-generating substance and a carrier-transporting substance. There is a particular thing. Still another object of the present invention is to provide a photoreceptor that has low temperature dependence and exhibits little decrease in sensitivity, especially at low temperatures. 4 Structure of the invention and its effects That is, the present invention comprises at least one kind selected from the group consisting of each polycyclic quinone pigment of the following general formula (A), (B) or (C), and which is purified by a sublimation purification method. Photoconductive particles having an average particle diameter of 2 μm or less obtained by the method are contained in the carrier generation layer as a carrier generation substance, and a styryl compound of the following general formula (P) is contained in the carrier transport layer as a carrier transport substance, and the carrier The present invention relates to a photoreceptor characterized in that a generation layer and a carrier transport layer are laminated. (However, in each of the above formulas, X represents a halogen atom, a nitro group, a cyano group, an acyl group, or a carboxyl group, n represents an integer of 0 to 4, and m represents an integer of 0 to 6.) (However, in the above formula, R ¹ and R ² are substituted or unsubstituted phenyl groups, and the substituent is an alkyl group or alkoxy group.) R ³ is a substituted or unsubstituted phenyl group, naphthyl group, or anthryl group. , represents a fluorenyl group or a heterocyclic group, and an alkyl group, an alkoxy group, a halogen atom, or a phenyl group is used as a substituent. R ⁴ represents hydrogen, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. ) According to the present invention, since the above-mentioned polycyclic quinone pigment is used as photoconductive particles, the sensitivity is higher than in the case of conventional inorganic particles or perylene pigments, and the photosensitive material is uniform and has good scratchability. You can get layers. In addition, since a polycyclic quinone pigment prepared by sublimation purification is used, it has higher sensitivity than photoreceptors using unpurified organic pigments, and can be repeatedly copied many times. Even in this case, since the accumulated residual potential is small and the potential increase in the background portion of the image is small, a clear copy image without fogging can be obtained. However, since the pigment purified by sublimation has a large particle size, the above-mentioned problems tend to occur. A notable feature of the present invention is that a polycyclic quinone pigment obtained by sublimation purification is contained in the photosensitive layer with an average particle size of 2 μm or less. That is, the present inventors have found that by reducing the average particle size of the pigment (polycyclic quinone pigments are acicular crystals, the length of their long axis is taken as the average particle size) to 2 μm or less. They have discovered that it is possible to prevent the influence of the particle size on the surface of the photoreceptor, to make the surface of the photoreceptor smooth, and to stabilize the pigment dispersion. Average particle size of polycyclic quinone pigment is 2μ
If the thickness exceeds m, convex portions 6 as shown in FIG. 2 will occur on the surface, but if the thickness is less than 2 μm, such convex portions can be virtually eliminated and a flat surface can be realized.
This makes it possible to stabilize the liquid by reducing sedimentation of particles in the dispersion. As a result, it is possible to obtain a photoreceptor that does not suffer from discharge breakdown or toner filming. It is essential that the average particle diameter of the polycyclic quinone pigment is 2 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less. However,
If the average grain size is too small, crystal defects will increase and sensitivity and repeatability will decrease, and there is a limit to miniaturization, so the lower limit of the average grain size must be set.
It is desirable to set it to 0.01 μm. In order to obtain a polycyclic quinone pigment having such an average particle size, it is desirable to grow the crystals by a sublimation purification method and then actively and thoroughly crush the particles using a crushing device. Examples of the crushing device include a ball mill, a hammer mill, a sand glider, a centrifugal mill, a colloid mill, a jet mill, and a turbo mill. Further, according to the present invention, since the styryl compound of the general formula (P) is used as a carrier transport material in combination with the polycyclic quinone photoconductive particles, the carrier transport ability is improved and the sensitivity is high. , high color sensitivity is obtained, and operation is stabilized during repeated use. Moreover, the carrier transport material made of this styryl compound has a particularly high hole mobility and a small temperature dependence, so that the decrease in sensitivity is small, especially at low temperatures. The liquid used to form the photosensitive layer in the present invention has an average particle size of the above polycyclic quinone pigment.
It can be obtained by dispersing photoconductive particles of 2 μm or less in a suitable organic solvent (which preferably contains a binder resin to improve adhesiveness). Further, a carrier transport substance may be added depending on the purpose before and/or after this dispersion step, thereby improving the charge transport function of the photocarrier generation layer itself. In addition, as a dispersion method, for example, a ball mill, a homogenizer, a sand grinder, a colloid mill,
A method using ultrasound or the like is applicable. Specific examples of compounds of the anthoanthrone pigment represented by the above general formula (A) used in the present invention are as follows. Specific examples of compounds of the dibenzpyrenequinone pigment represented by the general formula (B) are as follows. Specific examples of compounds of the pyranthrone pigment represented by general formula C are as follows. Furthermore, the following are specific examples of the styryl compound represented by the general formula (P). Further, examples of the binder resin that can be used in the present invention include polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin,
Addition polymerization type resins, polyaddition type resins, polycondensation type resins such as vinyl acetate resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, and repeating units of these resins Examples of copolymer resins containing two or more of these include vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, and the like. However, the binder resin is not limited to these, and all resins commonly used in such applications can be used. In particular, polycarbonate resins include linear polymers having repeating units represented by the following general formula (). General formula () In the formula, R' ₁ and R' ₂ each represent a hydrogen atom, an alkyl group (for example, methyl, ethyl, propyl, isofuropyl, butyl, t-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.) or an aryl group ( (e.g. phenyl, naphthyl, etc.)
and R' ₂ and R' ₂ may jointly form a hydrocarbon ring (including a cycloalkane ring such as a cyclohexyl ring and a polycycloalkane ring such as a norbornyl ring). Further, R' ₃ , R' ₄ , R' ₅ and R' ₆ each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogen atom (for example, a chlorine atom, a bromine atom, an iodine atom, etc.), and A teeth

【formula】

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【formula】

【formula】

[expression] and

[Formula] Represents a divalent group selected from the following. The alkyl group in R' ₁ and R' ₂ preferably has 1 to 22 carbon atoms, and the hydrocarbon ring preferably has 5 to 7 members, and the carbon atoms of the hydrocarbon ring are preferably 5 to 7 members. The total number is preferably in the range of 5 to 19. In addition, polycarbonate resins particularly preferably used in the present invention include linear polymers containing repeating units represented by the following general formula (). General formula () Here, R' represents a phenylene group, a halogen-substituted phenyl group, or an alkyl-substituted phenylene group (especially an alkyl-substituted phenylene group having 1 to 20 carbon atoms), and R' ₁ and R' ₂ each represent the general formula () of the polycarbonate. The same as R′ ₁ and R′ ₂ in . In the general formulas () and (), each group and each ring are not limited to unsubstituted ones, and include, for example, halogen atoms (e.g., chlorine atom, bromine atom, iodine atom, etc.), alkyl groups (e.g., carbon atoms of 1 to 20), It also includes those having substituents such as alkyl groups) and aryl groups. Further, examples of the organic solvent used in the present invention include methylene chloride, methylene bromide,
1,2-dichloroethane, sym-tetrachloroethane, cis-1,2-dichloroethylene, 1,1,
Examples include single solvents such as 2-trichloroethane, chloroform, bromoform, dioxane, tetrahydrofuran, and pyridine, and various mixed solvents containing these as main components. The ratio of organic solvent to resin is 0.1 to 40 parts by weight, preferably 1 to 20 parts by weight of resin per 100 parts by weight of organic solvent.
Parts by weight. The addition ratio of the carrier generating substance is 10 to 1000 parts by weight per 100 parts by weight of the resin.
Preferably it is 20 to 200 parts by weight. 5 Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Figure 3 shows the average particle size in the carrier generation layer 2.
This figure shows a functionally separated type electrophotographic photoreceptor containing the above-mentioned polycyclic quinone pigment particles 5 of 2 μm or less. In this case, the carrier generation layer 2 may or may not contain a binder resin. Even if they are not contained, the polycyclic quinone particles 5 can be retained in the photosensitive layer because the carrier transport layer 3 is provided as an upper layer. The dry film thickness of the carrier generation layer 2 is 0.05 to 10 μm, preferably 0.1 to 5 μm, and can be applied by ordinary dip coating,
It is applied by a coating method such as knife coating, roll coating or spray coating. In carrier generation layer 2,
The binder is preferably used in an amount of 0 to 500 (preferably 0 to 200) parts by weight per 100 parts by weight of the carrier generating substance (polycyclic quinone). Outside this range, if the binder exceeds 500 parts by weight, sensitivity will be insufficient. The carrier transport material used in the carrier transport layer 3 is the above-mentioned styryl compound. The blending ratio of the binder resin and the carrier transport material is preferably 10 to 300 parts by weight, preferably (50 to 200 parts by weight), per 100 parts by weight of the binder resin. Outside this range, if the amount of the carrier transport substance is too small, the effect will be poor, and if it is too large, the film forming ability will be poor and the charge retention property will be reduced. Further, the thickness of this carrier transport layer 3 is 2 to 100 microns, preferably 5 to 30 microns. The carrier transport layer 3 may contain various additives for the purpose of improving flexibility, reducing residual potential, and reducing fatigue during repeated use.
Such additives include diphenyl, diphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphate,
Examples include methylnaphthalene, benzophenone, chlorinated paraffin, dilaurylthiopropionate, and the like. The polycyclic quinone pigments mentioned above are different from ordinary dye-type pigments and are difficult to dissolve in solvents, but they have good weather resistance and have a specific crystal structure, so they have extremely excellent semiconductor properties. It has become a thing. Moreover, as the above-mentioned base 1, a conductive support is suitable, but a conductive film such as Al may be provided on the surface of the insulating support and a photosensitive layer may be formed thereon. As the material of the conductive support 1, for example, metals such as aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless steel, and brass can be used. In addition, in the carrier transport layer or photosensitive layer, a Lewis acid of 0.001 to 10% (preferably
It may be added in an amount of 0.01 to 1)% by weight. Lewis acids that can be used include succinic anhydride,
Maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4
-Nitrophthalic anhydride, pyromethic 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-funiolenylidene-[dicyanomethylenemalonodinitrile], polynitro-9
-Funiolenylidene-[dicyanomethylenemalonodinitrile], picric acid, o-nitrobenzoic acid,
p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid,
Examples include mellitic acid and other compounds with high electron affinity. Further, the above-mentioned photosensitive layer can also be formed on an intermediate layer (not shown) provided on a conductive support. This intermediate layer prevents the injection of free carriers from the conductive support into the photosensitive layer when the photosensitive layer is charged, and also functions as an adhesive layer that holds the photosensitive layer integrally bonded to the conductive support. fulfill Materials for this intermediate layer include metal oxides such as aluminum oxide and indium oxide, addition polymer resins such as acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, and epoxy resin, polyaddition resins, and polycondensation 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. Can be done. However, the resins that can be used here are not limited to these, and all resins that are commonly used for this purpose can be used. Next, specific examples of the present invention will be described. Example 1 Commercially available anthinthrone pigment “Monolite Red 2Y” represented by structural formula A3 (manufactured by ICI, CI No.
59300) was filled into a graphite evaporation source placed in a vacuum evaporation apparatus, sublimated at a temperature of 370°C for 60 minutes, and deposited on a substrate placed 25 cm above the evaporation source. After pulverizing 30 g of the obtained purified pigment in a ball mill for 24 hours, 1000 ml of 1,2-dichloroethane was added and a dispersion treatment was carried out for 24 hours to obtain a coating solution for forming a carrier generation layer. Next, the dry weight is 0.1 on a 120φ aluminum drum.
g/m ² of vinyl chloride-vinyl acetate-maleic anhydride copolymer resin "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) by a dip coating method, and then the carrier generation described above was applied. A layer-forming coating solution was applied onto the intermediate layer by the same dip coating method to obtain a carrier generation layer having a dry weight of 2.3 g/m ² . As a result of observation with an electron microscope,
The carrier generation layer was filled with pigment particles having an average particle size of 0.3 μm. On the other hand, styryl compounds represented by structural formula P9
112.5 g and 150 g of polycarbonate resin "Panlite L-1250" (manufactured by Teijin Kasei) were dissolved in 1,2-dichloroethane 1000 ml, and the resulting carrier transport layer forming coating liquid was applied to the carrier generating layer by a dip coating method. Applied over a layer to a dry weight of 19
A carrier transport layer of g/m ² was formed, and an electrophotographic photoreceptor (sample No. 1) of the present invention was prepared. Example 2 When preparing a coating solution for forming a carrier generation layer, after pulverizing a purified pigment, 30 g of polycarbonate resin was mixed with 1.
A carrier generating layer having a dry weight of 2.1 g/m ² was formed in the same manner as in Example 1, except that the dispersion treatment was carried out using a solution dissolved in 1000 ml of 2-dichloroethane. As a result of observation using an electron microscope, the carrier generation layer was filled with pigment particles having an average particle size of 0.3 μm. Furthermore, in the same manner as in Example 1, dry weight 19
An electrophotographic photoreceptor (sample No. 2) of the present invention was prepared by forming a carrier transport layer of g/m ² . Example 3 In place of the anthanthrone pigment in Example 2, a dibenzpyrene quinone pigment "Indanthrene Golden Yellow RK" (CINo.
59105) was used in the same manner as in Example 2,
An electrophotographic photoreceptor of the present invention (sample No. 3) was prepared.
As a result of electron microscopic observation, the carrier generation layer was filled with pigment particles having an average particle size of 0.5 μm. Example 4 The present invention was carried out in the same manner as in Example 2, except that a pyranthrone pigment “Pal:ogen Red 3340” (manufactured by BASF) represented by the structural formula C4 was used in place of the anthorone pigment in Example 2. An invention electrophotographic photoreceptor (sample No. 4) was prepared. As a result of electron microscopic observation, the carrier generation layer was filled with pigment particles having an average particle size of 0.4 μm. Example 5 Each sample No. 5 was prepared in the same manner as in Example 2, except that the particle size of the purified pigment was changed.
It was created. The average particle size of the photoconductive particles in these samples is shown in the table below. Comparative Example 1 Comparative sample No. 1 was prepared in the same manner as in Example 2, except that the pulverizing operation of the purified pigment was omitted. As a result of electron microscopic observation, the average particle size of the pigment particles in the carrier generation layer was 2.5 μm. Comparative Example 2 Comparative Sample No. 2 was prepared in the same manner as in Example, except that the commercially available polycyclic quinone pigment in Example 1 was used as the organic pigment without being purified by sublimation. Comparative Examples 3 to 4 The same procedure as in Example 2 was carried out, except that compounds represented by the structural formulas Q1 and Q2 below were used as carrier transport substances instead of the compounds represented by the general formula (P) of the present invention. , comparative samples No. 3 and No. 4 were prepared, respectively. Sample No. 1~ obtained in the above Examples and Comparative Examples
Mount No. 5 and comparative samples No. 1 to 4 on a drum testing machine, and calculate the charged potential V ₀ and the exposure amount E 1/2 (lux sec) required to attenuate V ₀ to 1/2. Ta. Next, each sample was mounted on a modified U-BixV2 (manufactured by Konishiroku Photo Industry Co., Ltd.), and the breakdown potential, which is the potential at which white spots begin to appear on the image when the charging potential is changed, was measured. The above results are also shown in the table below.

[Table] From the above results, based on the present invention, the average particle diameter of polycyclic quinone pigment particles (photoconductive particles) was set to 2.0 μm.
or less (preferably 1.0μm or less, more preferably
(0.5 μm or less), and when a styryl compound is used as the charge transport material, it can withstand repeated use while maintaining high sensitivity and has stable image quality.
Furthermore, it is possible to obtain a photoreceptor that is difficult to break down, has low temperature dependence, and exhibits little decrease in sensitivity, especially at low temperatures. It was also found that this photoreceptor was less likely to cause toner filming.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional electrophotographic photoreceptor;
The figure is a schematic enlarged cross-sectional view. FIG. 3 is a schematic enlarged sectional view of an electrophotographic photoreceptor according to an embodiment of the present invention. In addition, in the reference numerals shown in the drawings, 1... substrate, 2... carrier generation layer, 3... carrier transport layer, 4... photosensitive layer, 5... photoconductive particles.

Claims (1)

[Scope of Claims] 1. Average particles consisting of at least one selected from the group consisting of each polycyclic quinone pigment of the following general formula (A), (B) or (C) and obtained by a sublimation purification method. Diameter 2μm
The following photoconductive particles are contained in the carrier generation layer as a carrier generation substance, and the styryl compound of the following general formula (P) is contained in the carrier transport layer as a carrier transport substance, and the carrier generation layer and the carrier transport layer are laminated. A photoreceptor characterized by: (However, in each of the above formulas, X represents a halogen atom, a nitro group, a cyano group, an acyl group, or a carboxyl group, n represents an integer of 0 to 4, and m represents an integer of 0 to 6.) (However, in the above formula, R ¹ and R ² are substituted or unsubstituted phenyl groups, and the substituent is an alkyl group or alkoxy group.) R ³ is a substituted or unsubstituted phenyl group, naphthyl group, or anthryl group. , represents a fluorenyl group or a heterocyclic group, and an alkyl group, an alkoxy group, a halogen atom, or a phenyl group is used as a substituent. R ⁴ represents hydrogen, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. )