JPH0257300B2 - - Google Patents

Description

[Detailed description of the invention]

1. Field of Industrial Application The present invention provides a method for producing an electrophotographic photoreceptor, which comprises sequentially laminating a carrier generation layer containing a carrier generation substance and a carrier transport substance containing a carrier transport substance on a drum-shaped support. It is related to. 2. Prior Art In electrophotographic devices used in copying machines, laser printers, etc., drum-shaped photoreceptors are most widely used. This drum-shaped photoreceptor is characterized by having an endless image forming surface.
This feature has the advantage that the diameter of the drum can be made small and that the rotation control of the drum can be easily controlled. Since the drum-shaped photoreceptor has such characteristics, in addition to the general properties required of an electrophotographic photoreceptor, it is also required to have a seamless and endless photoreceptor surface. According to conventionally known electrophotographic photoreceptors, a carrier generating material (hereinafter sometimes referred to as ``CGM'') absorbs visible light and generates a charged carrier (hereinafter simply referred to as ``carrier''). A carrier generation layer (hereinafter sometimes referred to as "CGL") containing a A carrier transport layer (hereinafter referred to as
It is sometimes called "CTL". ) to form a photosensitive layer. in this way,
By assigning the two necessary basic functions of carrier generation and its transport to separate layers constituting the photosensitive layer, the selection range of materials that can be used for the composition of the photosensitive layer is widened, and each function is It becomes possible to independently select a material or material system that optimally achieves the following. In addition, this provides various properties required in the electrophotographic process, such as high surface potential when charged, high charge retention capacity, high photosensitivity, and high stability during repeated use. It becomes possible to obtain an electrophotographic photoreceptor having the following properties. As the above-mentioned photosensitive layer, for example, the following ones are known. (1) Consisting of amorphous selenium or cadmium sulfide
A structure in which CGL and CTL made of poly-N-vinylcarbazole are laminated. (2) Consisting of amorphous selenium or cadmium sulfide
A structure in which CGL and CTL containing 2,4,7-trinitro-9-fluorenone are laminated. (3) A structure in which CGL made of a berylene derivative and CTL containing an oxadiazole derivative are laminated (see US Pat. No. 3,871,882). (4) A structure in which a CGL made of chlordiane blue or methylscalyllium and a CTL containing a pyrazoline derivative are laminated (Japanese Patent Application Laid-Open No. 1973-
(See Publication No. 90827). (5) CGL made of amorphous selenium or its alloy;
A structure in which CTL containing a polyarylalkane-based aromatic amino compound is laminated (patent application)
52-147251). (6) A structure in which CGL containing a berylene derivative and CTL containing a polyarylalkane-based aromatic amino compound are laminated (Patent application 1973-
19907 specification). Efforts to obtain an electrophotographic photoreceptor with excellent electrophotographic properties and film strength by using a low-molecular-weight organic compound as a charge-transporting substance and using an arbitrary charge-generating substance and a polymer binder. is being done. In electrophotographic photoreceptors, CTL is usually formed by dispersing CTM in a polymer binder. As the polymer binder, polycarbonate is excellent in terms of charging characteristics, repeatability, etc. For example, bisphenol A type polycarbonate having the following structural unit may be mentioned. This polycarbonate has a structure in which two methyl groups are symmetrically bonded to the central carbon atom of bisphenol A. However, as a result of studies conducted by the present inventor, when a film is formed using the above-mentioned polycarbonate, crystalline polycarbonate tends to precipitate on the film surface during coating film formation, resulting in the formation of convex portions. It has been found that image defects are likely to occur due to so-called toner filming, in which the yield decreases due to drag, or when the toner is used as a photoconductor, toner adheres to the convex portions of the surface and remains without being cleaned. The reason for this is thought to be that in the above polycarbonate, the group bonded to the central carbon atom consists of the lowest methyl group, which gives rise to a high degree of molecular chain arrangement. Conventionally, drum-shaped photoreceptors have been manufactured using a dip coating method due to the need to form an endless photoreceptor surface. The liquid in the coating tank had to be replaced within a short period of time. For this reason, there were disadvantages in that a large amount of waste liquid was produced and the yield was low. Coating methods other than dip coating avoid such drawbacks due to the storage stability of the coating solution, but it is difficult to form an endless photosensitive surface. When coating and forming a photosensitive layer using the polycarbonate as a binder, various solvents may be used. For example, when ethylene chloride is used as a solvent, it has been found that since this solvent is a poor solvent, ordinary polycarbonate tends to crystallize when used in high concentrations. In particular, the concentration of polycarbonate in solution is 5% by weight (based on solvent).
It was found that crystallization occurs even at low concentrations, making it impossible to increase the concentration above 5% by weight. Such a phenomenon occurs similarly in the case of other solvents. 3. Purpose of the Invention The purpose of the present invention is to obtain a photoconductor with good reproducibility that has excellent charging performance, repeatability, printing durability, etc., has no abnormal protrusions on the surface, and is free from characteristic defects such as toner filming. The goal is to provide a method that can be used. 4 Structure of the invention and its effects That is, the present invention provides an electrophotographic photosensitive material in which a carrier generation layer containing a carrier generation substance and a carrier transport substance containing a carrier transport substance are sequentially laminated on a drum-shaped support. In the body manufacturing method,
The carrier transport layer is formed by a dip coating method in which a drum is immersed in a coating solution containing the carrier transport substance, a binder, and a solvent as main components, and at that time, the binder concentration in the coating solution is adjusted to The amount is 5% by weight or more based on the solvent, and as the binder, the following general formula [A]
The present invention relates to a method for manufacturing an electrophotographic photoreceptor, which uses a binder containing either a polycarbonate represented by the following general formula [B] as a main component or a polycarbonate represented by the following general formula [B]. General formula [A] (However, in this general formula, R ¹ , R ² : hydrogen atom, substituted or unsubstituted aliphatic group, substituted or unsubstituted carbocyclic group,
or a substituted or unsubstituted aromatic group, in which at least one of R ¹ and R ² is a bulky group having 3 or more carbon atoms, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , ^R9 , ^R10 : hydrogen atom, halogen atom, substituted or unsubstituted aliphatic group, or substituted or unsubstituted carbocyclic group n: 10-1000. ) General formula [B]: (However, in this general formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , n: the same as above, Z: substituted or unsubstituted carbon ring or (This is a group of atoms necessary to form a substituted or unsubstituted heterocycle.) According to the present invention, first, the photosensitive layer is formed by a dip coating method, so the photosensitive surface is seamless and uniform. A photosensitive layer can be obtained. In addition, polycarbonate of the above general formula [A] or [B] is used as the main component of the binder of the photosensitive layer, but at least one of the central carbon atoms of the bisphenol A portion of these polycarbonates is bulky ( ^{These _}
R ¹ and/or R ² or Z effectively prevents the polycarbonate molecular chains from aligning in a specific direction. Therefore, polycarbonate does not crystallize and precipitate on the film surface during the formation of the photosensitive layer, thereby preventing a decrease in yield due to abnormal convex portions and deterioration of characteristics such as image defects due to toner filming. These remarkable effects can be more fully exhibited if R ¹ and R ² in the above general formula [A] are different from each other or are bonded asymmetrically. In the above general formula [B], the ring formed by the above Z directly contributes to the above remarkable effect. As described above, since the polycarbonate used in the present invention is difficult to crystallize, it is necessary to make sure that the polycarbonate concentration in the solution is 5% by weight or more and that the solvent used is a poor solvent when forming the photosensitive layer. Also, crystallization of polycarbonate does not occur. Increasing the polycarbonate concentration to 5% by weight or more is itself a new configuration that could not be expected with conventional technology, and at the same time, the increased proportion (content) of polycarbonate improves the mechanical strength, printing durability, etc. of the photosensitive layer. can be done. Also,
By using a highly concentrated coating solution, dripping is reduced and the undesirable phenomenon of thinning of the film at one end of the drum due to dripping can be avoided. Furthermore, since the binder used in the present invention is polycarbonate-based, it is possible to impart to the photoreceptor the characteristics originally exhibited by polycarbonate, such as excellent charging performance, repeatability, and printing durability. Furthermore, the polycarbonate represented by the above general formula used in the present invention is more resistant to solvents such as ethylene chloride, tetrachloroethane, dioxane, tetrahydrofuran, and chloroform than conventional polycarbonate, that is, bisphenol A type polycarbonate. Since the compatibility is high, the following excellent effects can be achieved. In the coating process, liquid adheres to and dries on the walls of the coating machine, coating liquid tank, etc., and this may mix into the coating liquid, causing coating failures. In dip coating, particularly in dip coating of a drum-shaped photoreceptor, the level of the coating liquid rises and falls considerably as the drum is dipped and pulled up. As a result, the walls of the coating tank repeatedly get wet and dry. Since bisphenol A type polycarbonate has relatively low compatibility with solvents, it precipitates on the tank wall,
This has the disadvantage that it mixes into the coating liquid and causes convex portions on the surface of the photoreceptor, resulting in a decrease in yield and image defects due to toner filming. On the other hand, since the polycarbonate of the present invention has good compatibility with solvents, there is no precipitation even when the above-mentioned wetting and drying is repeated, there is no above-mentioned drawback, and the yield is significantly improved. Furthermore, the present invention has the following excellent effects. As mentioned above, the polycarbonate of the present invention has an excellent property of being difficult to crystallize. This property is very useful for dip coating of drum-shaped photoreceptors. The dip coating method requires a predetermined amount of liquid to be present at all times during coating. In particular, in the production of drum-shaped photoreceptors, since the volume of the drum is large, a large amount of coating liquid must always be present in the liquid tank. In contrast, in other coating methods, it is sufficient to supply only the amount of liquid to be consumed to the coating position. This point is a condition unique to dip coating. Coating liquids containing substances that easily crystallize are not suitable for dip coating because crystallization occurs in the liquid bath during long-term continuous production. On the other hand, since bisphenol A type polycarbonate easily crystallizes as described above, its liquid life in the tank is short and the liquid cannot be stored for a long period of time. On the other hand, the coating liquid containing the polycarbonate of the present invention has an extremely long liquid life in the tank. That is, a coating solution containing bisphenol A type polycarbonate has a lifespan of only about 7 days, whereas a coating solution containing the polycarbonate of the present invention has a lifespan of, for example, about 1 year. The economic benefits of this long fluid life are extremely large. That is, in the case of the conventional coating liquid, a huge amount of liquid is discarded, whereas in the case of the coating liquid of the present invention, it can be said that almost no liquid is discarded due to crystallization. Thus, it has been found that the polycarbonate represented by the above general formula [A] or [B] can be stored in solution form for an extremely long period of time compared to conventional polycarbonate, that is, bisphenol A type polycarbonate. The present invention was created by paying attention to this property of the above-mentioned polycarbonate. Among the above polycarbonates used in the present invention, those represented by general formula [A]
It is essential that at least one of R ¹ and R ² is a bulky group having 3 or more carbon atoms, but such a bulky group acts as a steric hindrance that hinders the molecular chain arrangement. Examples of such bulky groups having 3 or more carbon atoms include the following. (However, R ¹¹ is a hydrogen atom, an alkyl group such as a methyl group, (-CH ₂ )mCOOR ¹² (R ¹² is an alkyl group, m≧
alkyl ester group represented by 1) (3) Alkyl group represented by −CmH _2n+1 (however,
m≧4) (4) (−CH ₂ )mCOOR ¹² (However, R ¹² is an alkyl group, m≧2) In addition, when one of R ¹ and R ² is a bulky group,
The other may be a hydrogen atom or an alkyl group such as a methyl group. Next, R ³ ~ in the above general formulas [A] and [B]
The group R ¹⁰ may be a hydrogen atom, a halogen atom such as Cl, Br, or F, an alkyl group such as a methyl group, or a carbocyclic group such as a cyclohexyl group. In addition, in the polycarbonate of the general formula [B], the Z may form a 5- or 6-membered carbocyclic or heterocyclic ring, and such rings include a cyclohexyl ring, a cyclopentyl ring, etc. A substituent such as an acetyl group or an acetylsemino group may be introduced into a part of the ring. Specific examples of the polycarbonate used in the present invention include the following. Note that the polycarbonate used in the present invention occupies the main component of the binder, but other binder components that may be used in combination include ordinary polycarbonate as described above, polycarbonate without the above R ¹ , R ² , and Z, Alternatively, polyester, styrene-acrylic resin, etc. may be mentioned. The above polycarbonate is used as a binder for a photosensitive layer (particularly a charge transport layer of a functionally separated photoreceptor, or both a charge transport layer and a charge generation layer). Here, examples of the charge transport material (CTM) of the charge transport layer (CTL) include carbazole derivatives represented by the following general formula [] and hydrazone compounds represented by the following general formula []. General formula [] [However, in this general formula, R ¹³ : substituted or unsubstituted aryl group, R ¹⁴ : hydrogen atom, halogen atom, substituted or unsubstituted alkyl group, alkoxy group, amino group, substituted amino group, hydroxyl group, R ¹⁵ : Represents a substituted or unsubstituted aryl group, a substituted or unsubstituted multi-ring group. ] General formula []: [However, in this general formula, R ¹⁶ and R ¹⁷ each represent a hydrogen atom or a halogen atom, R ¹⁸ and R ¹⁹ each represent a substituted or unsubstituted aryl group, and Ar ¹ represents a substituted or unsubstituted arylene group. . ] Specific examples of the carbazole derivative represented by the general formula [ ] include those having the following structural formula, but are not limited thereto. Specific examples of the hydrazone compound represented by the general formula [] include those having the following structural formula, but are not limited thereto. Other usable CTMs include compounds represented by the following general formulas [], [], [], [], or []. General formula []: [However, in this general formula, R ²⁰ : substituted or unsubstituted aryl group or substituted or unsubstituted heterocyclic group, R ²¹ : hydrogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group, Q: hydrogen atom, halogen atom, alkyl group, substituted amino group, alkoxy group or cyano group; p: represents an integer of 0 or 1. ] General formula []: [However, in this general formula, R ²² : substituted or unsubstituted aryl group or substituted or unsubstituted heterocyclic group, R ²³ : hydrogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group, A hydrogen atom, a halogen atom, an alkyl group, a substituted amino group, an alkoxy group, or a cyano group; q: an integer of 0 or 1; ] General formula []: [However, in this general formula, l: 0 or 1, R ²⁴ , R ²⁵ and R ²⁶ : substituted or unsubstituted aryl group, R ²⁷ and R ²⁸ : hydrogen atom, alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aralkyl group (however, R ²⁷ and R ²⁸ are not both hydrogen atoms, and when l is 0,
R ²⁷ is not a hydrogen atom. )] General formula []: [However, in this general formula, R ²⁹ , R ³⁰ : substituted or unsubstituted alkyl group,
It represents a phenyl group, and an alkyl group, an alkoxy group, or a phenyl group is used as a substituent. R ³¹ : Represents a substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group, or heterocyclic group, and substituents include an alkyl group, an alkoxy group, a halogen atom,
Hydroxyl group and phenyl group are used. R ³² , R ³³ , R ³⁴ , R ³⁵ : represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or an alkylamino group. ] General formula []: [However, in this general formula, Ar ² and Ar ³ represent substituted or unsubstituted phenyl groups, and substituents include halogen atoms,
An alkyl group, nitro group, or alkoxy group is used. Ar ⁴ : substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group,
Represents a heterocyclic group, and substituents include an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an aryloxy group, an aryl group, an amino group, a nitro group, a piberidino group, a morpholino group, a naphthyl group, an anthryl group, and a substituted amino group. use However, an acyl group, an alkyl group, an aryl group, or an aralkyl group is used as a substituent for the substituted amino group. ] Specific examples of the hydrazone compound of the above general formula [] include those shown by the following structural formula, but are not limited thereto. Specific examples of the hydrazone compound represented by the general formula [] include those having the following structural formula, but are not limited thereto. Examples of the pyrazoline compound useful in the present invention represented by the general formula [] include those having the following structural formula. The pyrazoline compound used in the present invention described above is synthesized by a known method, for example, by dehydration condensation of an α,β-unsaturated ketone and phenylhydrazine in the presence of an acid catalyst. Specific examples of the styryl compound represented by the general formula [] include those having the following structural formula, but are not limited thereto. Specific examples of the amine derivative represented by the general formula [] include those having the following structural formula, but are not limited thereto. Next, examples of the charge generating substance (CGM) of the charge generating layer (CGL) include polycyclic quinone pigments represented by the following general formula [], [] or []. (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.) Photoconductive particles If the polycyclic quinone pigment described above is used as the pigment, the sensitivity will be higher than that of conventional inorganic particles or perylene pigments, and a photosensitive layer that is uniform and has good scratchability can be obtained. In addition, when a polycyclic quinone pigment made by sublimation purification is used, it has higher sensitivity than a photoreceptor using an unpurified organic pigment, and moreover, it can be used repeatedly for many copies. 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 capri can be obtained. However, since the pigment purified by sublimation has a large particle size, the above-mentioned problems tend to occur. Here, it is desirable that the polycyclic quinone pigment obtained by sublimation purification be contained in the photosensitive layer with an average particle size of 2 μm or less. That is, by making the average particle size of the pigment (polycyclic quinone pigment is a needle-like crystal, the length of its major axis is the average particle size) to 2 μm or less, it is possible to It has been found that the influence of the particle size can be prevented, the surface of the photoreceptor can be made smooth, and the pigment dispersion can be stabilized. When the average particle diameter of the polycyclic quinone pigment exceeds 2 μm, convex portions are likely to form on the surface, but when the average particle size is 2 μm or less, such convex portions can be virtually eliminated and a flat surface can be achieved, and the particles in the dispersion can be This reduces sedimentation and stabilizes the liquid. As a result, it is possible to obtain a photoreceptor that does not suffer from discharge breakdown or toner filming. The average particle size of polycyclic quinone pigment is 2μm
The thickness is preferably 1 μm or less, 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 deteriorate, and there will be a limit to miniaturization, so it is desirable to set the lower limit of the average grain size 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 grinding device include a ball mill, a hammer mill, a side grinder, a centrifugal mill, a colloid mill, a jet mill, and a turbo mill. The liquid used to form the photosensitive layer in the present invention has an average particle size of the above polycyclic quinone pigment.
Photoconductive particles of 2 μm or less are placed in a suitable organic solvent (this may contain a binder resin).
It can be obtained by dispersing it in Further, before and/or after this dispersion step, a carrier transport substance can be added depending on the purpose, thereby improving the charge transport function of the photocarrier generation layer itself. In addition, as a dispersion method, for example, a method using a ball mill, a homogenizer, a sand grinder, a colloid mill, an ultrasonic wave, etc. can be applied. Specific examples of compounds of the anthoanthrone pigment represented by the above general formula [] are as follows. Specific examples of compounds of the dibenzpyrenequinone pigment represented by the general formula [] are as follows. Specific compounds of the pyranthrone pigment represented by the general formula [] are as follows. Further, other CGMs that can be used include bisazo compounds represented by the following general formula [XI]. General formula [XI]: [However, in this general formula, Ar ⁵ and Ar ⁶ are each a substituted or unsubstituted carbocyclic aromatic ring group, or a substituted or unsubstituted heterocyclic aromatic ring group, R ³⁶ and R ³⁷ are each an electron Attractive group or hydrogen atom (at least one of R ³⁶ and R ³⁷
(Halogen such as -CN, -Cl, electron-withdrawing group such as _-NO2 ), A:

【formula】

【formula】

【formula】

[expression] or

【formula】 (X is a hydroxy group,

[Formula] or −NHSO ₂ −R ⁴¹ , <However, R ³⁹ and R ⁴⁰ are each a hydrogen atom,
Substituted or unsubstituted alkyl group, R ⁴¹ is a substituted or unsubstituted alkyl group or unsubstituted or unsubstituted aryl group> Y is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a carboxyl group , a sulfo group, a substituted or unsubstituted carbamoyl group, or a substituted or unsubstituted sulfamoyl group (however, when m is 2 or more, they may be mutually different groups) Z is a substituted or unsubstituted carbocyclic ring The atomic group necessary to constitute an aromatic ring or a substituted or unsubstituted heterocyclic aromatic ring, ^R38 is a hydrogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted carbamoyl group, or a carboxyl group. or an ester group thereof, A' is a substituted or unsubstituted aryl group, n is an integer of 1 or 2, and m is an integer of 0 to 4. ] Among the bisazo compounds represented by the general formula [XII], preferred are those represented by the following general formula [XIa]. General formula [XIa]: [However, Ar ⁵ , Ar ⁶ and A are the same as defined in general formula [XI]. ] Even more preferred are compounds in which Ar ⁵ and Ar ⁶ in the general formula [XIa] are as follows. Ar ⁵ , Ar ⁶ : Represents a substituted or unsubstituted phenyl group, and substituents include alkyl groups such as methyl group and ethyl group, alkoxy groups such as methoxy group and ethoxy group, chlorine atom,
Those selected from halogen atoms such as bromine atoms, hydroxyl groups and cyano groups. Specific examples of the bisazo compound represented by the general formula [XI] include those having the following structural formula, but are not limited thereto. Furthermore, as CGM, a bisazo compound represented by the following general formula [XII] can also be used. (However, in this general formula, A″ is

【formula】

【formula】

[expression] or

[Formula], Z: a group of atoms necessary to constitute a substituted or unsubstituted aromatic carbocycle or a substituted or unsubstituted aromatic heterocycle, Y: a hydrogen atom, a hydroxyl group, a carboxyl group, or an ester group thereof , sulfo group, substituted or unsubstituted carbamoyl group, or substituted or unsubstituted sulfamoyl group, R ⁴² : hydrogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted amino group, substituted or unsubstituted carbamoyl group , carboxyl group or its ester group, or cyano group, Ar ⁷ : substituted or unsubstituted aryl group, R ⁴³ : substituted or unsubstituted alkyl group, substituted or unsubstituted aralkyl group, or substituted or unsubstituted aryl group represents. ) Among the bisazo compounds of the above general formula [XII], carzole group-containing bisazo compounds represented by the following general formula [XII'] are effective. General formula [XII′]: (However, R ⁴⁴ and R ⁴⁵ are alkyl groups, alkoxy groups, or aryl groups, R ⁴⁶ , R ⁴⁷ , R ⁴⁸ , R ⁴⁹ , R ⁵⁰ , and R ⁵¹ are hydrogen atoms,
These are a halogen atom, an alkyl group, an alkoxy group, an amino group, a hydroxyl group, and an aryl group. ) This bisazo compound of the general formula [XII'] is thought to have a carbazole group in the molecule that contributes to the sensitizing effect, and it provides excellent sensitivity even in the long wavelength range, and the carbamoyl group in the molecule contributes to the sensitizing effect. In combination with the base portion, it acts effectively as a coupler, exhibiting good sensitivity characteristics over a wide wavelength range, and exhibiting excellent characteristics as a photoreceptor for semiconductor lasers. Specific examples of the bisazo compound represented by the general formula [XII] that are effective in the present invention include those represented by the following structural formula; is not limited. Next, the present invention will be specifically explained with reference to the drawings. The photoreceptor of the present invention is constructed as shown in FIG. 1, for example. That is, as already described on the conductive support 1
Carrier generation layer 2 containing CGM as a main component
is formed on this carrier generation layer 2, and the above-mentioned
Carrier transport layer 3 containing CTM as a main component
are layered to form a carrier generation layer 2 and a carrier transport layer 3.
The photosensitive layer 4 is constituted by this. Here, as the material of the conductive support 1, for example, metals such as aluminum, nickel, copper, zinc, palladium, silver, indium, tin, platinum, gold, stainless copper, and brass can be used. The invention is not limited to this, and for example, as shown in FIG. 2, the conductive support 1 may be constructed by providing a conductive layer 1B on an insulating substrate 1A. In this case, plastic is suitable as the substrate 1A. Further, the conductive layer 1B can be provided by laminating metal, vacuum-depositing metal, or by other methods. The carrier generation layer 2 is formed by CGM alone, by adding a suitable binder resin to it, or by adding a substance having a high mobility for carriers of specific or non-specific polarity (i.e., a carrier transport substance). can be formed. As a specific forming method, on the support
Examples include a method in which CGM is vacuum-deposited, and a method in which CGM is dissolved or dispersed in a suitable solvent alone or together with a suitable binder resin, coated (or dip coated), and dried. In this latter method, a binder resin or a carrier transport material may be added, and in this case, the ratio of carrier generating material: binder resin: carrier transport material is 1: by weight.
(0-100):(0-500), especially 1:(0-10):(0
~50) is preferable. Examples of the solvent or dispersion medium used in the above method include n-butylamine, diethylamine,
Ethylenediamine, isopropanolamine, monoethanolamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol , ethanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, and others can be used. In addition, as the binder resin, polycarbonate of the above-mentioned general formula [A] or [B] is preferable, but in addition, for example, polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, Phenol resin, polyurethane resin, polyester resin, alkyd resin, polycarbonate resin other than general formula [A] or [B], silicone resin, melamine resin, addition polymerization type resin, polyaddition type resin,
Polycondensation type resins, and copolymer resins containing two or more 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 the above insulating resins, examples include polymeric organic semiconductors such as poly-N-vinylcarbazole.
The ratio of this binder resin to CGM is CGM/binder resin = (0.1 to 10)/1
(weight ratio). 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, and the like. 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, tetracyanoxydimethane, o-dinitrobenzene,
m-dinitrobenzene, 1,3,5-trinitrobenzene, paranitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil,
Brumanil, dichlorodicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone,
2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 9-fluorenylidene [dicyanomethylenemalonodinitrile], polynitro 9-fluorenylidene-[dicyanomethylenemalonodinitrile] nitrile], picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, etc. Compounds with high electron affinity can be mentioned. Further, the addition ratio of the electron-accepting substance is carrier-generating substance:electron-accepting substance=100:0.01-200 in weight ratio, preferably
100: 0.1 to 100. The thickness of the CGL 2 formed as described above is preferably 0.005 to 20 μm, particularly preferably
It is 0.2-5 μm. If it is less than 0.005 μm, sufficient photosensitivity cannot be obtained, and if it exceeds 20 μm, sufficient charge retention cannot be obtained. Further, the CTL3 can be used in the same manner as the CGL2 described above (i.e., alone or together with the binder resin whose main component is polycarbonate).
It can be formed by dissolving and dispersing CTM, applying it, and drying it. And other CTMs
may be contained. In this case, the blending ratio of the binder resin and the total carrier transport material is preferably set to total carrier transport material/binder resin=(0.1 to 10) (furthermore, 0.5 to 20)/1 (weight ratio). 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. Note that the electron-accepting substance may be added to either one of the carrier transport layers. 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 thus formed is 2 to 100 μm, preferably 10 to 30 μm. As above, the present invention has been explained according to the specific structural example shown in FIG. 1 or FIG. This is sufficient, 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, and polycarbonates. Polymeric substances such as resin, silicone resin, melamine resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, etc. can be used. Note that the CGM and CTM that can be used in the present invention are not limited to those mentioned above, and other known substances and even known inorganic substances can also be used. Examples of such inorganic substances include zinc oxide, lead oxide, titanium oxide, zinc sulfide, lead sulfide,
Examples include cadmium sulfide and mercury sulfide. When coating and forming the above-mentioned CTL (or CGL in some cases), a solution containing CTM (or CGM) and a binder mainly composed of the above-mentioned polycarbonate is applied onto a support (substrate) and dried. In this case, the binder concentration of the solution should be 5% by weight or more based on the present invention. However, in order to completely avoid crystallization (or precipitation) of polycarbonate, it is desirable that the upper limit of the binder concentration be 30% by weight. Also, the viscosity (η) of the solution is 0.5
It is better to set it to ~1000 cp, and even better to set it to 3-300 cp. In addition, usable solvents include ethylene chloride, tetrachloroethane, tetrahydrofuran,
Examples include dioxane and chloroform. Although these solvents are relatively poor solvents, since the polycarbonate of the present invention is used as a binder, their crystallization does not occur. Further, dew condensation and clouding of the coating film (blushing) due to solvent evaporation, which can occur when a good solvent is used, does not occur. Next, a method for manufacturing the above-mentioned photoreceptor, for example, the photoreceptor shown in FIG. 1, will be described in particular for CTL (the same may be applied to CGL). In carrying out this method, the dip coating/drying apparatus shown in FIG. 4 can be used, but the present invention is not limited thereto, and other dip coating apparatuses can also be used. A drum-shaped substrate 1 held by a support rod 19 passing through a coating container 13 containing a coating liquid 12 (a solution containing the above-described CTM and a binder) is arranged so as to be movable up and down. Fourth
The figure shows the state in which the substrate 1 has been lowered and fully immersed in the coating liquid 12. A cylindrical cover member 14 having a through hole 15 on the side for adjusting the solvent vapor concentration distribution is connected to the container 13 and has approximately the same diameter as the container 13, and the inside thereof is a drying area 24. It's summery. Therefore, as shown in FIG. 5, from the immersion state in FIG. 4 (indicated by a dashed line in FIG. 5),
By raising the arm 18 to which the support rod 19 is fixed, the substrate 1 is pulled up from the coating liquid 12 as shown by the solid line in FIG. It consists of The substrate 1 is placed in a drying area 24 (i.e., the cover member 1
By lowering a new substrate from the state pulled up to the outside in step 4) and repeating the above operations, the outer surface of the substrate can be immersed in the coating liquid 12 and the coating liquid 12 can be applied and dried again. In addition, when the base body 1 is a simple cylinder, the base body 1 can be closed by covering the upper and lower openings with the lids 25 and 26 and tightening them with the nuts 20.
The coating liquid 12 is prevented from entering the inside (however, the upper lid 25 is not necessarily required depending on the immersion depth of the substrate 1). On the other hand, the vertical movement mechanism of the arm 18 is constructed as follows. That is, the support 21 is placed on the substrate 22.
a and 21b are fixed in the vertical direction, and their upper ends are fixed to the upper substrate 23. This upper board 23
A feed screw rod 16 extending vertically downward is pivotally supported. The lower end of this feed screw rod 16 is a support 21
The motor 1 is fixed to the lower surface of the fixing plate 27 by passing through the center of the fixing plate 27 fixed to a and 21b.
It is integrated with the rotating shaft of 7. Arm 18 above
A female thread 28 corresponding to the feed screw rod 16 is cut in the feed screw rod 16, and the feed screw rod 16 is passed through the arm 18 while being screwed into this female screw, whereby the arm 18 is supported by the feed screw rod 16. Tsutsu,
As the feed screw rod 16 is rotated by the motor 17, it is moved up and down. 5 Examples Hereinafter, the present invention will be described in more detail with reference to specific examples. Example 1 On a drum cylinder with a diameter of 80 mm and made of aluminum as a base, an intermediate layer with a thickness of about 0.1 μm made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "Eslec MF-10" (manufactured by Sekisui Chemical Co., Ltd.) was placed. The layer was applied using the coating apparatus of FIG. Next, 2 g of the bisazo compound shown by the structural formula (XI-5) described above.
was dispersed in a ball mill for 12 hours with 100 ml of 1,2-dichloroethane, and the resulting dispersion was similarly coated on the intermediate layer, and dried sufficiently to form a layer with a thickness of approx.
A 0.3 μm CGL was formed. On the other hand, 11.25 g of the styryl compound shown by the structural formula (-18) already mentioned and 15 g of the polycarbonate shown by the already mentioned structural formula (B-2) were dissolved in 100 ml of ethylene chloride (the binder concentration is relative to the solvent). 15% by weight), the obtained solution was applied on the CGL in the same manner, and dried at a temperature of 80°C for 1 hour to a thickness of 14 μm.
A CTL was formed, and an electrophotographic photoreceptor according to the present invention was manufactured. This will be referred to as "Sample 1". Examples 2 to 5 In the formation of CGL, the structural formula (-
3) Four types of electrophotographic photoreceptors based on the present invention were produced in exactly the same manner as in Example 1, except that those shown in (-3), (-4), and (XII-2) were used, respectively. did. These will be referred to as "Sample 2,""Sample3,""Sample4," and "Sample 5," respectively. Examples 6 to 7 In the formation of CTL, the structural formula (A-
An electrophotographic photoreceptor according to the present invention was produced in the same manner as in Example 1 except that the compounds shown in 1) and (A-10) were used. These will be referred to as "Sample 6" and "Sample 7." Example 8 In Example 2, the same polycarbonate as CTL was used as a binder when forming CGL,
An electrophotographic photoreceptor according to the present invention was produced in the same manner except that the compound represented by (-14) was used as CTM. This will be referred to as "Sample 8." Comparative Example 1 A comparative electrophotographic photoreceptor was produced in the same manner as in Example 1, except that a known bisphenol A type polycarbonate was used as the binder in forming the CTL in Example 1. This is called “Comparative Sample 1”
shall be. Comparative Example 2 A comparative electrophotographic photoreceptor (“Comparative Sample 2”) was prepared in the same manner as in Example 1, except that the binder concentration in the coating liquid used when forming CTL was 4% by weight based on the solvent. However, because the viscosity of the coating liquid was low and the liquid flowed down rapidly, the CTL film thickness was as thin as 5 μm. Electrophotographic photoreceptors obtained as above (Samples 1 to 8 and Comparative Sample 1 and Comparative Sample 2)
The electrophotographic properties of each were investigated using a drum tester. In other words, the charged potential of the photoreceptor
V _A (V) and the exposure amount E1/2 (lux·sec) required to attenuate V _A to 1/2 were investigated. The results were as shown in Table 1 below.

[Table] In addition, each of Samples 1 to 8, Comparative Sample 1, and Comparative Sample 2 was
BixV2" modified machine (manufactured by Konishiroku Photo Industry Co., Ltd.) to perform continuous copying, black paper potential V _b (V) and white paper potential V _W (V), "electrostatic voltmeter - 144D-ID type" (manufactured by Monroe Electronics Inc.), and was measured immediately before development. The results were as shown in Table 2 below. The black paper potential here refers to the surface potential of the photoreceptor when the above-mentioned 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 copying cycle described above is performed using black paper with a reflection density of 1.3 as the original. Represents the surface potential of the photoreceptor.

[Table] (However, in the above table, ΔV _b (V) and ΔV _W (V)
are the black paper potential V _b (V) and the white paper potential V _W
(V) indicates the amount of variation, and the amount of variation indicates an increase.
represents a decrease. ) On the other hand, when the surface conditions of the photoreceptors according to each of the above examples were observed, the results shown in Table 3 below were obtained.

[Table] From the results, it was found that the photoreceptor according to the present invention had good surface properties and did not cause toner filming. Furthermore, it was confirmed that in Comparative Example 2, sufficient image density could not be obtained.

[Brief explanation of drawings]

The drawings show examples of the present invention, and FIGS. 1, 2, 3, and 5 are cross-sectional views of three examples of electrophotographic photoreceptors, and FIG. 4 is a diagram illustrating dip coating and drying. A schematic cross-sectional view of the apparatus, FIG. 5 is a schematic cross-sectional view during dip coating. In addition, in the symbols shown in the drawings, 1...substrate, 2...carrier generation layer (CGL), 3...carrier transport layer (CTL), 4...photosensitive layer, 12...coating liquid, 24... It is a dry area.

Claims (1)

[Scope of Claims] 1. A method for producing an electrophotographic photoreceptor comprising sequentially laminating a carrier generation layer containing a carrier generation substance and a carrier transport layer containing a carrier transport substance on a drum-shaped support, comprising: The carrier transport layer is formed by a dip coating method in which a drum is immersed in a coating solution containing a carrier transport substance, a binder, and a solvent as main components, and at that time, the binder concentration in the coating solution is adjusted to 5% by weight or more, and as the binder, a binder whose main component is either a polycarbonate represented by the following general formula [A] or a polycarbonate represented by the following general formula [B]. A method for producing an electrophotographic photoreceptor, the method comprising: General formula [A] (However, in this general formula, R ¹ , R ² : hydrogen atom, substituted or unsubstituted aliphatic group, substituted or unsubstituted carbocyclic group,
or a substituted or unsubstituted aromatic group, in which at least one of R ¹ and R ² is a bulky group having 3 or more carbon atoms, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , ^R9 , ^R10 : hydrogen atom, halogen atom, substituted or unsubstituted aliphatic group, or substituted or unsubstituted carbocyclic group, n: 10-1000. ) General formula [B] (However, in this general formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , n: the same as above, Z: substituted or unsubstituted carbon ring or A group of atoms necessary to form a substituted or unsubstituted heterocycle.)