JPH0713355A - Laminated electrophotographic photoreceptor and method for manufacturing the same - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a laminated electrophotographic photoreceptor having high sensitivity and a wide spectral sensitivity region, and a method for producing the same. [Structure] On a conductive support or a conductive support having an undercoat layer, as a charge generation layer, a mixed layer of an electron-accepting pigment and an electron-accepting pigment prepared by a vacuum deposition method (a light absorbing region of both pigments). Which are different from each other are preferably provided), and a charge transport layer is further provided on the laminated electrophotographic photoreceptor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly to a laminated electrophotographic photosensitive member used in a copying machine, a printer or the like using an electrophotographic process, and a method for producing the same.

[0002]

2. Description of the Related Art Since the electrophotographic process uses the visualization of a latent image by electrostatic force as a principle, the electrophotographic photosensitive member used in the process has a good charging property and a rapid surface potential due to light irradiation. And damping is required. The characteristics required for the electrophotographic photosensitive member in such a process depend on the height of dark resistance, which is a physical property value, good quantum efficiency, and high charge mobility. As those satisfying these physical property values, conventionally, inorganic substances such as those using selenium and its alloys, or photoreceptors in which dye-sensitized zinc oxide is dispersed in a binder resin, and organic substances are also used. 2,4,7-trinitro-9-fluorenone (hereinafter "T
A representative example is one using a charge transfer complex of poly (N-vinylcarbazole) (hereinafter referred to as “PVK”) and NF ”.

However, these photoreceptors have many advantages and, at the same time, have various drawbacks. For example,
Currently used selenium photoconductors are difficult to manufacture, high in manufacturing cost, difficult to process into a belt due to lack of flexibility, and also sensitive to heat and mechanical shock. Need attention. Zinc oxide photoconductor can be manufactured by applying it to a support using inexpensive zinc oxide, but the cost is low, but in general, sensitivity is low, surface smoothness, hardness, tensile strength, abrasion resistance, etc. There is a mechanical defect, and there are many problems in durability as a photoreceptor for a plain paper copying machine which is usually used repeatedly. Further, a photoconductor using a charge transfer complex of TNF and PVK has low sensitivity and is not suitable as a photoconductor for a high speed copying machine.

In recent years, extensive research has been conducted in order to eliminate the drawbacks of these photoconductors, and in particular, various organic photoconductors have been proposed. Among them, a laminated type photoreceptor in which a thin film of an organic pigment is formed on a conductive support (charge generation layer), and a layer mainly composed of a charge transport material (charge transport layer) is formed on the conductive support is known. It is attracting attention as a photoconductor for a plain paper copying machine because of its high sensitivity and stable charging property compared to organic substances, and some of them have been put to practical use.

The chargeability, sensitivity, and electrostatic characteristics of this type of photoreceptor largely depend on the charge generation layer. As the charge generating material used in such a charge generating layer, those using a perylene pigment (see USP3877182) and those using a phthalocyanine pigment (Japanese Patent Publication No. 49-4338).
JP-A-58-182639, JP-A-60-19151
No.), using an azo pigment (JP-B-55-423)
80, JP-A-55-89443), squalium pigments, polycyclic quinone pigments and the like. Among these charge generating materials, the photoreceptor using a perylene pigment has low sensitivity for high-speed copying machines and has a pigment absorption of 600 or less.
Since it is limited to the wavelength side shorter than nm, it has no sensitivity to red light and is unsuitable as a photoconductor for a color copying machine. On the other hand, those using phthalocyanine pigments have low sensitivity to light near 500 nm, and have various crystal types, which change due to environmental changes such as temperature and humidity, and the use cycle such as charging and exposure, and thus the charging property is high. In addition, there is a defect that the sensitivity changes greatly during use. Further, when using an azo pigment, it is difficult to prepare a coating liquid having stable dispersibility during the production of the charge generation layer, and in addition, the light stability of the pigment is poor and it is difficult to highly purify the pigment. have. In fact, the photoconductors using other charge generating substances have not yet obtained sufficient sensitivity and spectral sensitivity regions.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated electrophotographic photosensitive member having high sensitivity and a wide spectral sensitivity region, and a method for producing the same.

[0007]

According to the present invention, an electron-donating pigment and an electron-accepting layer prepared by a vacuum deposition method as a charge generating layer are formed on a conductive support or a conductive support having an undercoat layer. Provided is a multilayer electrophotographic photoreceptor comprising a mixed layer of pigments, and further a charge transport layer provided thereon, and in particular, an electron donating pigment and an electron accepting pigment constituting the charge generating layer. However, the laminated electrophotographic photosensitive member is provided, which has different light absorption regions.
Further, a charge generating layer comprising a mixed layer of an electron-donating pigment and an electron-accepting pigment is provided on a conductive support or a conductive support having an undercoat layer by a vacuum vapor deposition method, and a charge transport layer is further formed thereon. In the method for manufacturing a multi-layer electrophotographic photosensitive member, the vacuum vapor deposition method is a vapor deposition method using an evaporation source of each of the two pigments, or a mixed state or a mixed crystal state of the two pigments. There is provided a method for producing a laminated electrophotographic photosensitive member, which is any one of the vapor deposition methods using the vapor deposition source.

That is, as a result of intensive studies by the present inventors, the object was achieved by providing a mixed layer formed by vacuum deposition of an electron-accepting pigment and an electron-donating pigment as a charge generation layer of a laminated electrophotographic photoreceptor. Therefore, the present invention has been completed.

The present invention will be described in more detail below. The electrophotographic photosensitive member is required to have a function of forming an electrostatic latent image by partially irradiating light with electric charges uniformly provided on the surface of the photosensitive member by corona discharge or the like. When the photoconductor is a layered photoconductor, incident light is absorbed by the charge generation layer to generate holes and electron carriers, and when the surface of the photoconductor is negatively charged, holes are injected into the charge transport layer, The electric field moves to the surface and neutralizes the negative charges on the surface, while the electrons generated in the charge generation layer neutralize the positive charges induced on the conductive support. As a result, an electrostatic latent image is formed on the surface of the photoconductor. Characteristics required for the photoreceptor in this operation include chargeability in a dark place, rapid light decay, and a small residual potential after light irradiation. These are the light absorption of the charge generation layer, quantum efficiency, and
It is well known that it depends largely on physical properties such as carrier mobility.

In the present invention, by using a mixed layer formed by vacuum vapor deposition of an electron-accepting pigment and an electron-donating pigment as the charge generating layer of such a laminated type photoreceptor, a photosensitive layer having high sensitivity and a wide spectral sensitivity range is obtained. The body was obtained. The reason why the charge generation layer of the present invention is particularly effective has not been clarified yet, but it is considered that there are the following factors. Effect of using mixed state of electron-donating pigment and electron-accepting pigment as charge generation layer a) Mixing of electron-donating pigment and electron-accepting pigment causes carrier generation from photoexcited state through exciplex, and therefore quantum efficiency Has improved. b) The mobility of both hole and electron carriers in the charge generation layer was improved by mixing the electron donating pigment and the electron accepting pigment. c) The spectral sensitivity of the charge generation layer was widened by mixing the electron-donating pigment and the electron-accepting pigment with pigments having different light absorption regions. d) A new crystalline state with high quantum efficiency was formed by mixing the electron-donating pigment and the electron-accepting pigment. Effect of using vacuum deposition as a method for producing a mixed charge generating layer of an electron-donating pigment and an electron-accepting pigment a) A trowel that uniformly disperses the electron-donating pigment and the electron-accepting pigment at the molecular level can be obtained. Area improved. b) The charge generation layer can be thinned, which is advantageous for carrier movement in the charge generation layer.

The laminated electrophotographic photoreceptor of the present invention has, for example, the structure shown in FIG. The photoreceptor of FIG.
A laminated photosensitive layer 14 comprising a mixed charge generation layer 12 of an electron-donating pigment and an electron-accepting pigment formed on a conductive support 11 by vacuum vapor deposition, and a charge-transporting layer 13 mainly composed of a charge-transporting substance. It is provided. In addition, the conductive support 1
An undercoat layer for holding a potential may be provided between 1 and the charge generation layer 12.

Next, the method of forming the charge generation layer of the present invention will be described. The vacuum evaporation method is a well-known technique as a uniform film forming method without pinholes, and the film thickness can be easily controlled. As a method for forming the mixed charge generation layer, three methods, that is, vacuum deposition from a mixed state of both pigments, vacuum co-deposition from each single evaporation source, and vacuum deposition from a mixed state are particularly effective. The vacuum vapor deposition method from the mixed state of materials has the advantages that there are few control points in vapor deposition, the operation is simple, and the manufacturing is possible at low cost. However, when the difference in evaporation temperature is large, it is difficult to control the component ratio in the charge generation layer (for example, polycyclic quinone pigment anthanthrone and phthalocyanine pigment). It is also not suitable when the reaction occurs during heating and evaporation (quinacridone pigment and aluminum chlorothalocyanine). In contrast, the vacuum co-evaporation method from a single evaporation source for each pigment can overcome the above-mentioned drawbacks. However, there are many control points in vapor deposition, the operation is complicated, and the cost exceeds the previous method. On the other hand, in the vacuum vapor deposition method from the mixed crystal state, there is a possibility that two kinds of molecules are vapor-deposited together in an association state, and it is possible to form a more molecularly dispersed film. As a mixed crystal production method, for example, two kinds of pigments are dissolved in a strong acid or strong base solvent,
There are methods such as mixing and dropping into water, and sublimation purification from a mixed material.

The present invention uses a mixed layer of an electron-donating pigment and an electron-accepting pigment formed by a vacuum deposition method as the charge generation layer. What chemical structure is effective as these materials? Is not clear. However, as a result of intensive studies, phthalocyanine pigments and quinacridone pigments can be particularly preferably used as the electron-donating pigment. Examples of such phthalocyanine pigments include metal-free phthalocyanine, copper phthalocyanine, zinc phthalocyanine, nickel phthalocyanine, platinum phthalocyanine, magnesium phthalocyanine, chlorinated copper phthalocyanine, chlorinated zinc phthalocyanine, iron phthalocyanine, aluminum chlorophthalocyanine, aluminum fluorophthalocyanine, aluminum. Bromphthalocyanine, indium chlorophthalocyanine,
Examples thereof include indium bromphthalocyanine, gallium chlorophthalocyanine, chlorinated aluminum chlorophthalocyanine, vanadium phthalocyanine, and oxotitanyl phthalocyanine.

The quinacridone pigments include unsubstituted quinacridone, 2,9-dichloroquinacridone, and 3,1.
0-dichlorquinacridone, 4,11-dichlorquinacridone, 3,4,10,11-tetrachlorquinacridone, 2,4,9,11-tetrachlorquinacridone,
1,2,8,9-tetrachloroquinacridone, 1,2,
4,8,9,11-hexachlorquinacridone, 2,
4,9,11-Tetrabromoquinacridone, 2,3
9,10-Tetrabromoquinacridone, 2,3,9,1
0-Tetrabromoquinacridone, 1,4,8,11-Tetrabromoquinacridone, 2,4,9,11-Tetrafluoroquinacridone, 1,4,8,11-Tetrafluoroquinacridone, 2,4,9,11- Tetraiodoquinacridone, 2,9-dimethylquinacridone, 3,10-
Dimethylquinacridone, 4,11-dimethylquinacridone, 3,4,10,11-tetramethylquinacridone,
2,4,9,11-tetramethylquinacridone, 1,
2,8,9-tetramethylquinacridone, 1,4,8,
11-tetramethylquinacridone, 2,9-dimethoxyquinacridone, 3,10-dimethoxyquinacridone,
4,11-dimethoxyquinacridone, 2,4,9,11
-Tetramethoxyquinacridone, 1,4,8,11-tetramethoxyquinacridone and the like can be mentioned. These electron donating pigments are synthesized by a known method.

Particularly preferred as the electron-accepting pigment used in the present invention are perylene tetracarboxylic acid diimide pigments, perylene tetracarboxylic acid diimidazole pigments, polycyclic quinone pigments, anthraquinone acridone pigments, and naphthalene tetracarboxylic acid diimidazole pigments. Pigments can be used.

Examples of the perylene tetracarboxylic acid diimide pigment include the exemplified compounds shown in Table 1 below.

[Table 1- (1)]

[Table 1- (2)]

Examples of the above-mentioned diimidazole pigment of perylenetetracarboxylic acid include the exemplified compounds shown in Table 2 below.

[Table 2]

Examples of the anthraquinone acridone pigment include the exemplified compounds shown in Table 3 below.

[Table 3- (1)]

[Table 3- (2)]

[Table 3- (3)]

[Table 3- (4)]

[Table 3- (5)]

[Table 3- (6)]

[Table 3- (7)]

[Table 3- (8)]

The polycyclic quinone pigments are listed in Table 4 below.
The exemplified compounds shown in are listed.

[Table 4- (1)]

[Table 4- (2)]

[Table 4- (3)]

[Table 4- (4)]

[Table 4- (5)]

[Table 4- (6)]

[Table 4- (7)]

[Table 4- (8)]

Examples of the naphthalenetetracarboxylic acid diimidazole pigment include the exemplified compounds shown in Table 5 below.

[Table 5- (1)]

[Table 5- (2)]

These electron accepting pigments are synthesized by a known method.

In the laminated electrophotographic photoreceptor of the present invention, the effect is particularly high when the electron-donating pigment and the electron-accepting pigment constituting the charge generating layer have different absorption regions. Examples of the combination include, for example, perylene tetracarboxylic acid diimide pigments such as perylene tetracarboxylic acid dimethyl imide (430 to 600 nm) and metal-free phthalocyanine (570 to 720 nm), phthalocyanine pigments such as oxotitanyl phthalocyanine (630 to 850 nm) or 2,7. -Dimethylquinacridone (500-620n
m) and other quinacridone pigments, perylenetetracarboxylic acid bisphenylimidazole (460 to 760 nm) and other perylene tetracarboxylic acid diimidazole pigments, and metal-free phthalocyanines (570 to 720 nm), oxotitanyl phthalocyanine (630 to 850 nm) and other phthalocyanine pigments. Or 2,7-dimethylquinacridone (50
0 to 620 nm) and other quinacridone pigments, bromanthanthrone (440 to 560 nm), flavanthrone (350 to 530 nm) and other polycyclic quinone pigments and metal-free phthalocyanines (570 to 720 nm), oxotitanyl phthalocyanine (630 to 850 nm), etc. Phthalocyanine pigment or 2,7-dimethylquinacridone (500
To 620 nm), anthraquinone acridone pigments such as unsubstituted anthraquinone acridone (470 to 670 nm) and metal-free phthalocyanine (570
~ 720 nm), oxotitanyl phthalocyanine (63
Phthalocyanine pigments such as 0 to 850 nm) or 2,7
Quinacridone pigments such as dimethylquinacridone (500-620 nm), naphthalene tetracarboxylic acid tran
s-Bisphenylimidazole (380-580 nm)
And naphthalene tetracarboxylic acid diimidazole pigments and phthalocyanine pigments such as metal-free phthalocyanine (570 to 720 nm) and oxotitanyl phthalocyanine (630 to 850 nm) and quinacridone pigments such as 2,7 dimethylquinacridone (500 to 620 nm).

Next, each layer of the laminated electrophotographic photoreceptor of the present invention will be described. In FIG. 1, the composition ratio of the electron-donating pigment and the electron-accepting pigment forming the charge generation layer 12 is
Electron-donating pigment: electron-accepting pigment = 1: 9 to 9: 1, preferably 3: 7 to 7: 3, and the effect is small outside the range of 1: 9 to 9: 1. The thickness of the charge generation layer 12 constituting the laminated photosensitive layer 14 is preferably 0.01 to.
It is 3 μm, more preferably 0.05 to 1 μm. If this thickness is 0.01 μm or less, light absorption and generation of electric charges are not sufficient, and if it is 3 μm or more, dark attenuation is large.
There are problems such as low chargeability, and it is not practical.

In FIG. 1, the charge transport layer 13 is mainly composed of a charge transport material and a binder, and further comprises a plasticizer, an antioxidant,
An ultraviolet deterioration preventing agent and the like can be contained. The proportion of the charge transport material in the charge transport layer is 10 to 95% by weight, preferably 30 to 90% by weight. If the proportion of the charge transport material is less than 10% by weight, the charge is hardly transported, and if it is more than 95% by weight, the mechanical strength of the photoreceptor film is extremely poor and it cannot be put to practical use. However, when the charge transport material is a polymer compound, it can be used at 100% by weight. The thickness of the charge transport layer 13 is preferably 3 to
The thickness is 50 μm, more preferably 5 to 30 μm. If this thickness is 3 μm or less, the charge amount is insufficient,
If it is more than μm, the residual potential is high and not practical.

The laminated type photoreceptor of the present invention is characterized by using a mixed layer of an electron-donating pigment and an electron-accepting pigment formed by a vacuum deposition method as a charge generation layer, and a conductive support. As the other constituents such as the charge transporting material and the binder used in the charge transporting layer, any of the conventionally known constituents can be used, which will be specifically described below.

As the conductive support used in the present invention, a metal plate of aluminum, nickel, copper, zinc or the like, a metal drum or a metal foil, aluminum, copper, gold,
A plastic film vapor-deposited or coated with a conductive material such as tin oxide or indium oxide, or a conductive-treated paper is used.

Examples of the binder include polyethylene, polypropylene, polyamide, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin. , Addition polymerization resins such as melamine resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more of the repeating units of these resins, for example vinyl chloride-vinyl acetate copolymer, chloride In addition to insulating resins such as vinyl-vinyl acetate-maleic anhydride copolymer resins, poly-
Examples include polymer organic semiconductors such as N-vinylcarbazole.

As the plasticizer, halogenated paraffin,
Examples thereof include polychlorinated biphenyl, dimethyl naphthalene, dibutyl phthalate and the like.

In addition, examples of the antioxidative agent include phenols and amines such as hindantphenol and hindantamine, and examples of the ultraviolet ray deterioration inhibitor include ketones such as benzophenone and heterocycles such as triazole. To be Silicone oil or the like may be added to improve the surface property of the photoconductor.

The charge transport material includes a hole transport material and an electron transport material. Examples of the hole transport material include 9-ethylcarbazole-3-aldehyde 1-methyl-1-phenylhydrazone, 9-ethylcarbazole-3-aldehyde 1,
1-diphenylhydrazone, 4-diethylaminostyrene-β-aldehyde 1-methyl-1-phenylhydrazone, 4-methoxynaphthalene-1-aldehyde 1-benzyl-1-phenylhydrazone, 4-methoxybenzaldehyde 1-methyl-1-phenyl Hydrazone, 2,4
-Dimethoxybenzaldehyde 1-benzyl-1-ferrahydrazone, 4-diethylaminobenzaldehyde 1,1-diphenylhydrazone, 4-methoxybenzaldehyde 1-benzil-1- (4-methoxyphenyl)
Hydrazone, 4-diphenylaminobenzaldehyde 1
-Hydrazone compounds such as benzyl-1-phenylhydrazone and 4-dibenzylaminobenzaldehyde 1,1-diphenylhydrazone. 1,1-bis (4-dibenzylaminophenyl) propane, tris (4-diethylaminophenyl) methane,
Triphenylmethane compounds such as 2,2'-dimethyl-4,4'-bis (diethylamino) -triphenylmethane or diphenylmethane compounds, 9- (4-diethylaminostyryl) anthracene, 9-bromo-10-
(4-Diethylaminostyryl) anthracene, 9-
(4-Dimethylaminostyryl) fluorene, 3- (9
-Fluorenylidene) -9-ethylcarbazole, 1,
2-bis (2,4-diethylaminostyryl) benzene, 1,2-bis (2,4-dimethoxystyryl) benzene, 3-styryl-9-ethylcarbazole, 3-
(4-methoxystyryl) -9-ethylcarbazole,
4-diphenylaminostilbene, 4-dibenzylaminostilbene, 4-ditolylaminostilbene, 1-
(4-diphenylaminostyryl) naphthalene, 1-
(4-Diethylaminostyryl) + phthalene, 4'-diphenylamino-α-phenylstilbene, 4'-methylphenylamino-α-phenylstilbene and other stilbene compounds, or aryl vinyl compounds, 1-phenyl-3- (4- Diethylaminostyryl) -5- (4-
Diethylaminophenyl) pyrazoline, 1-phenyl-
Pyrazoline compounds such as 3- (4-dimethylaminostyryl) -5- (4-dimethylaminophenyl) pyrazoline, 2,5-bis (4-diethylaminophenyl)-
1,3,4-oxadiazole, 2,5-bis [4-
(4-Diethylaminostyryl) phenyl] -1,3,
4-oxadiazole, 2- (9-ethylcarbazolyl-3-)-5- (4-diethylaminophenyl) -1,
3,4-oxadiazole, 2-vinyl-4- (2-chlorophenyl) -5- (4-diethylaminophenyl)
Oxazole, 2- (4-diethylaminophenyl)-
Heterocyclic compounds such as 4-phenyloxazole, triphenylamine, tri-p-tolylamine, 4,4'-dimethoxytriphenylamine, N, N'-bis (3-methylphenyl) -N, N'-diphenylbenzidine , 1,
1-bis (4-di-p-triphenylaminophenyl)
Cyclohexane, N, N, N ', N'-tetra (p-tolyl) benzidine, N, N, N', N'-tetra (p-
There are triphenylamine compounds such as tolyl) -o-phenylenediamine and N, N'-bis (4-methoxyphenyl) -1-aminopyrene, or low molecular compounds such as triarylamine compounds. Further, polymer compounds such as poly-N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, pyreneformaldehyde resin, ethylcarbazoleformaldehyde resin, and polysilane such as polyphenylmethylsilane can also be used.

Examples of the electron transport layer include chloroanil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone. , Diphenoquinone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone,
2,6,8, -Trinitro-4H-indeno [1,2-
b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, succinic anhydride, maleic anhydride, phthalic acid, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 4-nitro Phthalic anhydride, 3-nitrophthalic anhydride, pyromellitic dianhydride,
Picric acid, o-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitomesalicylic acid, o-dinitrobenzene, m-dinitrobenzene, 1,3,5 -Trinitrobenzene, p-nitrobenzonitrile, picryl chloride, dichlorodicyano-p-benzoquinone, anthraquinone, chloroanthraquinone, dichloroanthraquinone, dinitroanthraquinone, 9-fluorenylidene [dicyanomethylene malonodinitrile], fluorenylideneaniline derivative, etc. Examples include compounds having a high electron affinity. These charge transport materials may be used alone or in combination of two or more.

As the material of the undercoat layer, which is optionally provided between the conductive support and the charge generation layer in the photoreceptor of FIG. 1, polyamide, polyvinyl alcohol, ethyl cellulose, nitrocellulose, aluminum oxide or the like is used. It is suitable and the film thickness is preferably 1 μm or less.

Next, a method for manufacturing the laminated electrophotographic photosensitive member of the present invention will be described. The charge generation layer is formed on the conductive support by the above-mentioned vacuum deposition method, and then the charge transport layer is formed by coating and drying a solution in which a charge transport substance and a binder are dissolved in an organic solvent. The coating method is carried out by a conventional means such as a doctor blade, dipping, a wire bar, or a spray.

To make a copy using the photoreceptor of the present invention,
It is achieved by charging and exposing the surface of the photosensitive layer, developing it, and transferring it to paper or the like as necessary.

[0035]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

Example 1 On a polyethylene film provided with an aluminum layer as a conductive support by vapor deposition, a methanol solution of polyamide (CM-8000 manufactured by Toray Co., Ltd.) was applied as an undercoat layer to form a film.
It is provided with a thickness of 4 μm, and a perylene tetracarboxylic acid dimethylimide (PL-ME exemplified compound No. A-2) and a metal-free phthalocyanine (H ₂ P) are provided thereon as a charge generation layer.
The mixed layer of c) was formed by vacuum evaporation. Vacuum deposition is P
L-ME (80 mg) and H ₂ Pc (80 mg) were placed in different molybdenum boats, respectively, and simultaneously heated from two evaporation sources by a resistance heating method to form a 0.2 μm charge generation layer. The degree of vacuum during vapor deposition is approximately 5 × 10 ^-6 torr, and the vapor deposition rate is 4 to
It was controlled so that the evaporation rates of both pigments were 10 A / S and that they were almost equal. On the charge generation layer thus obtained, the compound 2 of the following structural formula (1) is used as a charge transport material.
Weight part, Polycarbonate Z (PcZ) 3 as a binder
Wt. Parts, and 0.0005 parts by weight of silicone oil dissolved in 20 parts by weight of tetrahydrofuran are blade-coated to form a charge transport layer having a thickness of about 20 .mu.m. 1 was produced.

[Chemical 1]

Example 2 In forming the charge generation layer of Example 1, PL-ME80m
g and H ₂ Pc 80 mg were mixed well in advance in a mortar, put in a molybdenum boat, and vacuum-deposited by resistance heating. 2 was produced.

Example 3 The same as Example 1 except that a polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1 and the compound of the following structural formula (2) was used as the charge transport layer. Perform photoconductor No. 3 was produced.

[Chemical 2]

Example 4 Photoreceptor No. 1 was carried out in the same manner as in Example 1 except that oxotitanyl phthalocyanine (TiOPc) was used as the electron donating pigment in the charge generation layer of Example 1. 4 was produced.

Example 5 2,7-as the electron-donating pigment for the charge generation layer of Example 1
Photoconductor No. 1 was carried out in the same manner as in Example 1 except that dimethylquinacridone (QA-ME) was used. 5 was produced.

Example 6 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and perylene tetracarboxylic acid bisphenylimidazole (PL-IM Exemplified Compound No.) was used as the electron-accepting pigment of the charge generation layer. .B-
1) was used and the same procedure as in Example 1 was carried out except that the compound represented by the structural formula (2) was used as the charge transport material.
6 was produced.

Example 7 Anthraquinone acridone pigment (AAQ Exemplified Compound No. C- as an electron-donating pigment for the charge generation layer of Example 1)
21) was carried out in the same manner as in Example 1 except that the photoconductor N
o. 7 was produced.

Example 8 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and Bromanthanthrone (BrAA) was used as the electron-accepting pigment of the charge generation layer.
N Exemplified Compound No. Example 1 except that D-5) was used and the compound of the above structural formula (2) was used as the charge transport material.
The same procedure as for the photoconductor No. 8 was produced.

Example 9 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and flavanthrone (FA exemplified compound No. D-33) was used as the electron-accepting pigment of the charge generation layer. , Photoconductor No. 1 was carried out in the same manner as in Example 1 except that the compound represented by the structural formula (2) was used as the charge transport material. 9 was produced.

Example 10 As in Example 1, except that naphthalenetetracarboxylic acid trans-diphenylimidazole (NL-plM Exemplified Compound No. E-1) was used as the electron-accepting pigment in the charge generation layer of Example 1. Perform photoconductor No. 10 was produced.

Comparative Example 1 Photoreceptor No. 1 was carried out in the same manner as in Example 1 except that the charge generation layer of Example 1 was formed by vacuum vapor deposition using a single material of metal-free phthalocyanine (H ₂ Pc) as an electron donating pigment. A ratio of 1 was made.

Comparative Example 2 The procedure of Example 1 was repeated except that the charge generation layer of Example 1 was formed by vacuum vapor deposition of a single material of perylenetetracarboxylic acid dimethylimide (PL-ME Exemplified Product No. A-2) which is an electron-accepting pigment. Performed in the same manner as in Example 1 Ratio 2 was made.

Comparative Example 3 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and the charge generation layer was a metal-free phthalocyanine (H ₂ Pc) which was an electron-donating pigment.
Photoreceptor No. 1 was prepared in the same manner as in Example 1 except that the single material was formed by vacuum vapor deposition and the compound represented by the structural formula (2) was used as the charge transport material. Ratio 3 was made.

Comparative Example 4 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and perylene tetracarboxylic acid dimethylimide (PL-ME Exemplified Compound No.) which is an electron-accepting pigment for the charge generation layer was used. A-2) Photoreceptor No. 1 was performed in the same manner as in Example 1 except that the single material was formed by vacuum vapor deposition and the compound represented by the structural formula (2) was used as the charge transport material. Ratio 4 was made.

Comparative Example 5 Photoreceptor N was prepared in the same manner as in Example 1 except that the charge generation layer of Example 1 was formed by vacuum vapor deposition of a single material of oxotitanyl phthalocyanine (TiOPc) which is an electron donating pigment.
o. A ratio of 5 was made.

Comparative Example 6 The charge generating layer of Example 1 was prepared using the electron donating pigment 2,7-
Photoreceptor N was prepared in the same manner as in Example 1 except that dimethylquinacridone (QA-MF) alone was used for vacuum deposition.
o. Ratio 6 was made.

Comparative Example 7 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and perylene tetracarboxylic acid dimethylimide (PL-IM Exemplified Compound No.) which is an electron-accepting pigment for the charge generation layer was used. B-1) Photosensitive member No. 1 was formed in the same manner as in Example 1 except that the single material was formed by vacuum vapor deposition and the compound represented by the structural formula (2) was used as the charge transport material. Ratio 7 was made.

Comparative Example 8 An anthraquinone acridone pigment (AAQ Exemplified Compound No. C-
21) Example 1 except that the single material was formed by vacuum evaporation
The same procedure as for the photoconductor No. A ratio of 8 was made.

Comparative Example 9 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and the charge generating layer was a bromoanthanthrone (BrAA) electron-accepting pigment.
N Exemplified Compound No. D-5) Performed in the same manner as in Example 1 except that the single material was formed by vacuum vapor deposition, and the compound of the structural formula (2) was used as the charge transport material. Ratio 9
Was produced.

Comparative Example 10 A polyethylene film provided with an ITO layer by sputtering was used as the conductive support of Example 1, and flavanthrone (FA exemplified compound No. D-33), which is an electron-accepting pigment, was used alone as a charge generation layer. Photoreceptor No. 1 was performed in the same manner as in Example 1 except that the material was formed by vacuum vapor deposition and the compound of the structural formula (2) was used as the charge transport material. A ratio of 10 was made.

Comparative Example 11 The charge generating layer of Example 1 was formed by vacuum vapor deposition of a single material of naphthalenetetracarboxylic acid trans-diphenylimidazole (NL-pLM exemplified No. E-1) which is an electron-accepting pigment. Is carried out in the same manner as in Example 1, and the photoconductor No. A ratio of 11 was made.

With respect to the photoreceptor obtained as described above, an electrostatic copying paper test apparatus (SP-42 manufactured by Kawaguchi Electric Railway Co., Ltd.) was used.
In 8), the exposure amount (E1 / E1) required for the charging by the corona discharge of + or −6 kV to reduce the charging potential Vs (surface potential value 20 seconds after the start of charging) and the surface potential after light irradiation to 1/2.
2) was measured. The results shown in Table 6 were obtained.

[Table 6]

No. 1, No. Ratio 1, No. Ratio 2
The surface potential of the photosensitive member of -800V to -400V
FIG. 2 shows the spectral sensitivities obtained by measuring the optical energy required to reduce the voltage to V at each wavelength. No. It can be seen that the photoconductor of No. 1 has a wider spectral sensitivity than the photoconductor of the comparative example and the sensitivity is improved. Further, the photosensitive member of Example 8 (photosensitive member No. 8) was attached to a drum having a linear velocity of 260 mm / s, and positive charging, white light exposure, and light quenching were repeated, and the charging potential (V
d), the post-exposure potential (Vl) was measured, and the results shown in Table 7 were obtained, confirming that sufficient repeatability was obtained.

[Table 7]

[0059]

EFFECT OF THE INVENTION The laminated electrophotographic photoreceptor of the present invention is provided with a mixed layer formed by vacuum vapor deposition of an electron-accepting pigment and an electron-donating pigment as a charge generating layer, so that it is highly sensitive and wide. It has excellent characteristics such as having a spectral sensitivity range. The effect is particularly high when the light absorbing regions of the electron-donating pigment and the electron-accepting pigment constituting the charge generation layer are different, and as the electron-donating pigment, a phthalocyanine pigment,
Quinacridone pigment, as the electron-accepting pigment, when using perylene tetracarboxylic acid diimide pigment, perylene tetracarboxylic acid diimidazole pigment, anthraquinone acridone pigment, polycyclic quinone pigment, naphthalene tetracarboxylic acid diimidazole pigment, particularly good properties Is obtained. In addition, the charge generation layer can be effectively formed by a vacuum vapor deposition method such as co-evaporation using separate evaporation sources for each pigment, or vapor deposition from a mixed state or a mixed crystal state of both pigments.

[Brief description of drawings]

FIG. 1 is a schematic view of a laminated electrophotographic photoreceptor of the present invention.

2 is a graph showing the spectral sensitivity of each electrophotographic photosensitive member of Example 1, Comparative Example 1 and Comparative Example 2. FIG.

[Explanation of symbols]

 11 Conductive Support 12 Charge Generation Layer 13 Charge Transport Layer 14 Laminated Photosensitive Layer

Claims (3)

[Claims] 1. A mixed layer of an electron-donating pigment and an electron-accepting pigment prepared by a vacuum vapor deposition method is provided as a charge generation layer on a conductive support or a conductive support having an undercoat layer, and further thereon. A laminated electrophotographic photosensitive member, characterized in that a charge transport layer is provided on the. 2. The laminated electrophotographic photosensitive member according to claim 1, wherein the electron-donating pigment and the electron-accepting pigment forming the charge generation layer have different light absorption regions. 3. A charge generating layer comprising a mixed layer of an electron-donating pigment and an electron-accepting pigment is provided on a conductive support or a conductive support having an undercoat layer by a vacuum vapor deposition method, and further thereon. In the method for manufacturing a multi-layer electrophotographic photosensitive member provided with a charge transport layer, the vacuum vapor deposition method is a vapor deposition method using a separate evaporation source for each of the two pigments, or a mixed state of the two pigments, or A method for producing a laminated electrophotographic photosensitive member, which is any one of vapor deposition methods using a vapor deposition source in a mixed crystal state.