JPH07128890A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic photoreceptor having panchromatism and very high sensitivity over a wide wavelength region from a visible region to a near IR region and excellent in potential stability at the time of continuous use. CONSTITUTION:In this electrophotographic photoreceptor with a photosensitive layer on the electric conductive substrate, the photosensitive layer contains an X type metal-free phthalocyanine pigment and a disazo pigment represented by the formula (where A and B are residues of couplers different from each other in structure).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
More specifically, it relates to a panchromatic electrophotographic photosensitive member having extremely high sensitivity over a wide wavelength range from the visible region to the near infrared region.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as Se, CdS and ZnO have been used as photoconductive materials for electrophotographic photoreceptors, but they have problems such as photosensitivity, thermal stability and toxicity. In recent years, electrophotographic photoreceptors using organic photoconductive materials have been actively developed, and electrophotographic photoreceptors having a photosensitive layer containing a charge generation material and a charge transport material have already been put to practical use. Has reached. On the other hand, for electrophotographic photoconductors, from the viewpoint of the advent of electrophotographic devices that use semiconductor lasers as light sources, such as laser printers and digital copiers, and the commonization of photoconductors, a wide range of spectral sensitivity characteristics from visible to near infrared Are beginning to be required to have.

Conventionally, it has been proposed to use two or more kinds of pigments having spectral sensitivity characteristics in different spectral regions as charge generating materials used for these photoconductors. For example, JP-A-63-148264 and JP-A-1-177.
No. 53, Japanese Unexamined Patent Publication No. 1-276060, and the like. However, although the spectral sensitivity range is expanded by using two or more kinds of pigments as the charge generation material,
There are problems that the sensitivity is not flat, the sensitivity is remarkably reduced locally, and conversely, the characteristics of the pigment itself cannot be utilized, which is not sufficient. Moreover, it cannot be said that the sensitivity is sufficient.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above conventional problems. Therefore, an object of the present invention is to provide an electrophotographic photosensitive member having a wide and flat spectral sensitivity from the visible region to the near infrared region and having extremely high sensitivity.

[0005]

According to the present invention, in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer is represented by an X-type metal-free phthalocyanine pigment and the following general formula (I). Disclosed is an electrophotographic photoreceptor containing the disazo pigment.

[Chemical 1] (In the formula, A and B represent coupler residues having different structures.) According to the invention, the photosensitive layer has a charge generation layer and a charge transport layer, and at least the charge generation layer is X-type. There is provided the above electrophotographic photoreceptor containing a metal-free phthalocyanine pigment and a disazo pigment represented by the general formula (I). Further, according to the present invention, there is provided the above electrophotographic photoreceptor, wherein the disazo pigment is a compound represented by the following formula (II).

[Chemical 2]

The X-type metal-free phthalocyanine used in the present invention is described in USP 357989, USP 3594163 and the like, and can be obtained by milling α-type metal-free phthalocyanine.

The photosensitive layer of the electrophotographic photosensitive member of the present invention further contains a disazo pigment represented by the following general formula (I).

[Chemical 1] (In the formula, A and B represent coupler residues having different structures.)

In formula (I), preferred examples of couplers A and B include coupler residues represented by the following formulas (IV) to (IX).

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

In the general formulas (IV) and (V), X is a naphthalene ring which may be condensed with a benzene ring and may have a substituent.
It represents a residue necessary for forming a hydrocarbon ring or a heterocyclic group such as an anthracene ring, a carbazole ring, a benzcarbazole ring, a dibenzofuran ring and a dibenzothiophene ring. In formula (VIII), Y represents a divalent aromatic hydrocarbon group which may have a substituent or a divalent heterocyclic group containing a nitrogen atom in the ring.

In the general formulas (IV) and (V), R ₁ ,
R ₂ , R ₃ and R ₄ represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group, and R ₁ and R ₂ and R ₃ and R ₄ are both nitrogen atoms. May be bonded to form a cyclic amino group containing a nitrogen atom in the ring. In formula (VI), R ₅ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group.

In the general formulas (VII) and (VIII),
R _6, R ₇ represents an alkyl group which may have a substituent, an aryl group, an aralkyl group or a heterocyclic group. General formula (V
In I) and (VII), Ar ₁ and Ar ₂ represent an aryl group which may have a substituent or a heterocyclic group. General formula (I
In V), p represents 0 or 1.

The alkyl group in the above expression is a group such as methyl, ethyl, propyl, etc., the aralkyl group is a group such as benzyl and phenethyl, the aryl group is a group such as phenyl, naphthyl and anthryl, the heterocyclic group is pyridyl, Examples thereof include groups such as thienyl, thiazolyl, carbazolyl, benzimidazolyl, and benzothiazolyl, and as the cyclic amino group containing a nitrogen atom in the ring, pyrrole, pyrroline, pyrrolidine, pyrrolidone, indole,
Indolyl, carbazole, imidazole, pyrazole, pyrazoline, oxazine, phenoxazine and the like can be mentioned.

Further, as the substituent, methyl, ethyl,
Alkyl groups such as propyl and butyl, alkoxy groups such as methoxy, ethoxy and propoxy, halogen atoms such as fluorine atom, chlorine atom and bromine atom, dialkylamino groups such as dimethylamino and diethylamino, phenylcarbamoyl group, nitro group and cyano. Group, a halomethyl group such as trifluoromethyl, and the like.

Specific examples of the disazo pigment represented by the general formula (I) are shown below, but the disazo pigment of the present invention is not limited thereto.

[Table 1- (1)]

[Table 1- (2)]

[Table 1- (3)]

[Table 1- (4)]

[Table 1- (5)]

[Table 1- (6)]

[Table 1- (7)]

[Table 1- (8)]

[Table 1- (9)]

[Table 1- (10)]

[Table 1- (11)]

In the disazo pigment represented by the general formula (1), a corresponding diazonium salt compound and a coupler corresponding to A or B are sequentially reacted in two steps or the first A is used.
Alternatively, it can be obtained by isolating the diazonium salt compound obtained by the coupling reaction with B and then further reacting the remaining coupler. The reason why these disazo pigments show a good combination with the specific X-type metal-free phthalocyanine pigment of the present invention is that both pigments have good dispersibility and easily interact with each other, and have an energy level that is easily matched in terms of energy level. However, it is easy to interact with each other.

The present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a constitutional example of an electrophotographic photosensitive member of the present invention, which contains an X-type metal-free phthalocyanine pigment and a disazo compound represented by the general formula (I) according to the present invention on a conductive support 11. The photosensitive layer 15 is laminated. FIG. 2 is a cross-sectional view showing another configuration example of the present invention, in which an intermediate layer 13 is provided between the conductive support 11 and the photosensitive layer 15. 3 and 4 are cross-sectional views showing another constitutional example of the present invention, in which the photosensitive layer 15 comprises the charge generation layer 17 containing the X-type metal-free phthalocyanine pigment according to the present invention and the disazo pigment according to the present invention. It is configured by stacking the charge transport layers 19 contained therein. FIG. 5 is a cross-sectional view showing still another configuration example of the present invention, in which a protective layer 21 is provided on the photosensitive layer 15.

As the conductive support 11, the volume resistance 10
Those exhibiting conductivity of ¹⁰ Ω · cm or less, for example, metal such as aluminum, nickel, chromium, nichrome, copper, gold, silver and platinum, metal oxide such as tin oxide and indium oxide, by vapor deposition or sputtering, Film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel, etc. plates and the like, after being formed into a raw tube by a method such as extrusion or drawing, cutting, superfinishing, polishing, etc. It is possible to use a surface-treated tube or the like. Further, the endless nickel bell and the endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support 11.

In addition to the above, a support obtained by dispersing conductive powder in a suitable binder resin and coating it on the above support can also be used as the conductive support 11 of the present invention. As the conductive powder, carbon black, acetylene black, aluminum, nickel, iron, nichrome, copper, zinc,
Examples thereof include metal powder such as silver, metal oxide powder such as conductive tin oxide and ITO. Further, the binder resin used at the same time, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer,
Styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin , Polyvinyl butyral, polyvinyl formal, polyvinyltoluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, and other thermoplastic, thermosetting resin or photocurable resin Resin is an example. Such a conductive layer can be provided by dispersing these conductive powders and a binder resin in a suitable solvent, for example, THF, MDC, MEK, toluene or the like and applying the dispersion.

Further, the heat-shrinkable tube in which the above-mentioned conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, and Teflon on a suitable cylindrical substrate is electrically conductive. Those provided with a layer can also be favorably used as the conductive support 11 of the present invention. The charge generation layer 17 may be formed only from the X-type metal-free phthalocyanine pigment and the disazo pigment represented by the general formula (I), or may be formed by the X-type metal-free phthalocyanine pigment and the disazo pigment represented by the general formula (I). The pigment may be formed by being dispersed in the binder resin. Therefore, in the charge generation layer 17, these components are dispersed in a suitable solvent by using a ball mill, an attritor, a sand mill, ultrasonic waves, or the like,
It is formed by applying this on the conductive support 11 or the intermediate layer 13 and drying. The content ratio of the X-type metal-free phthalocyanian and the disazo pigment represented by the general formula (1) is preferably 2: 1 to 1:10.
When the amount of X-type metal-free phthalocyanian is more than 2: 1, the sensitivity in the visible region is insufficient, and when the amount of the disazo pigment is more than 1:10, the sensitivity in the near infrared region is lowered.

As the binder resin used for the charge generation layer 17, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-
N-vinylcarbazole, polyacrylamide, polyvinylbenzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinylpyridine,
Cellulosic resin, casein, polyvinyl alcohol,
Examples thereof include polyvinylpyrrolidone. The amount of the binder resin is appropriately 0 to 500 parts by weight, preferably 10 to 300 parts by weight, based on 100 parts by weight of the charge generating substance. The thickness of the charge generation layer is 0.01 to 5 μm, preferably 0.1 to 2 μm.

As the solvent used here, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane,
Examples include toluene, xylene, ligroin, and the like. As the coating method of the coating liquid, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used. As the charge generation layer coating solution, the X-type metal-free phthalocyanine pigment and the disazo pigment represented by the general formula (I) are separately dispersed to prepare a coating solution, which is then mixed to prepare a charge generation layer. A coating solution may be used, but it is preferable to use a coating solution prepared by crushing, mixing, or milling these two pigments at the same time as a coating solution for the charge generation layer so that a photoreceptor having higher sensitivity can be obtained. become. Although the reason for this is not clear, it is considered that pulverization, mixing, or milling treatment facilitates the interaction between the pigments and improves the charge generation efficiency, thereby improving the sensitivity.

The charge transport layer 19 can be formed by dissolving or dispersing a charge transport substance and a binder resin in a suitable solvent, applying the solution on the charge generating layer, and drying the solution. Also,
If necessary, a plasticizer, a leveling agent, an antioxidant and the like can be added.

The charge transport material includes a hole transport material and an electron transport material. Examples of the charge transport substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone and 2,4. , 5,7-Tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Examples thereof include electron-accepting substances such as trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and benzoquinone derivative.

As the hole transport material, poly-N-vinylcarbazole and its derivative, poly-γ-carbazolylethylglutamate and its derivative, pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative, diarylamine derivative, triarylamine derivative, stilbene derivative,
α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9
-Styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives and other known materials can be used. These charge transport materials may be used alone or in combination of two or more.

As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, poly Vinyl acetate, polyvinylidene chloride, polyalate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane Thermoplastic or thermosetting resins such as resins, phenolic resins and alkyd resins can be mentioned.

The amount of the charge transport material is 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin.
Parts by weight are suitable. The thickness of the charge transport layer is 5 to 5
It is preferably about 0 μm. As the solvent used here, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone or the like is used.

In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 19. As the plasticizer, those used as a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount of the plasticizer used is preferably about 0 to 30% by weight based on the binder resin. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount thereof is 0 to the binder resin. 1% by weight is suitable.

Next, the case where the photosensitive layer 15 has a single layer structure will be described. Also in this case, most of them are of the function-separated type, which is composed of a charge-generating substance and a charge-transporting substance. That is, an X-type metal-free phthalocyanine pigment and a disazo pigment can be used as the charge generating substance and the charge transporting substance. The single-layer photosensitive layer can be formed by dissolving or dispersing the charge-generating substance, the charge-transporting substance and the binder resin in a suitable solvent, coating and drying the solution. If necessary, a plasticizer, a leveling agent, an antioxidant, etc. can be added.

As the binder resin, the binder resins previously mentioned for the charge transport layer 19 may be used as they are, or the charge generation layer 1 may be used.
You may mix and use the binder resin mentioned in 7. A photoconductor obtained by adding a hole-transporting substance to a eutectic complex formed of a pyrylium-based dye, bisphenol-based, or polycarbonate can also be used as the single-layer photoconductor. The amount of the charge generating substance is preferably 5 to 40 parts by weight, and the amount of the charge transporting substance is preferably 50 to 150 parts by weight, relative to 100 parts by weight of the binder resin. The single-layer photosensitive layer is a dip coating method, a spray coating method, a beading method, in which a charge generating substance, a charge transporting substance, and a binder resin are dispersed by a disperser using a solvent such as tetrahydrofuran, dioxane, dichloroethane or cyclohexane. It can be formed by coating with a coat or the like. The thickness of the single photosensitive layer is 5
Approximately 50 μm is suitable.

In the present invention, as shown in FIG. 2, the intermediate layer 1 is provided between the conductive support 11 and the photosensitive layer 15.
3 can be provided. The intermediate layer 13 generally contains a resin as a main component, but considering that the photosensitive layer is coated on the intermediate layer 13 with a solvent, the intermediate layer 13 is a resin having high solvent resistance to a general organic solvent. desirable. Examples of such resins include polyvinyl alcohol, casein, water-soluble resins such as sodium polyacrylate, copolymerized nylon,
Alcohol-soluble resin such as methoxymethylated nylon,
Examples thereof include curable resins that form a three-dimensional network structure, such as polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy resin. Also, the intermediate layer 1
Numeral 3 indicates titanium oxide, silica, alumina, zirconium oxide, tin oxide, for preventing moire and reducing residual potential.
You may add the fine powder pigment of the metal oxide which can be illustrated with cindium oxide etc.

The intermediate layer 13 can be formed by using an appropriate solvent and coating method as in the above-mentioned photosensitive layer. Further, as the intermediate layer 13 of the present invention, a silane coupling agent,
A titanium coupling agent, a chromium coupling agent, etc. can also be used. In addition, in the intermediate layer 13 of the present invention,
Al ₂ O ₃ provided by anodic oxidation, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , Ti
An inorganic substance such as O ₂ , ITO or CeO ₂ provided by a vacuum thin film forming method can also be favorably used. The thickness of the intermediate layer 13 is 0
-5 μm is suitable.

The protective layer 21 is provided for the purpose of protecting the surface of the photoconductor, and the materials used therefor are ABS resin and A
CS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, Polyethylene terephthalate, polyimide, acrylic resin, polymethyl bentene,
Examples thereof include resins such as polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. In addition to the protective layer, a fluororesin such as polytetrafluoroethylene, a silicone resin, and a dispersion of an inorganic material such as titanium oxide, tin oxide, or potassium titanate in these resins for the purpose of improving wear resistance. Can be added.
As a method for forming the protective layer, a usual coating method is adopted. The protective layer preferably has a thickness of about 0.1 to 10 μm.
In addition to the above, a- formed by vacuum thin film forming method
Known materials such as C and a-SiC can be used as the protective layer.

In the present invention, it is possible to provide another intermediate layer (not shown) between the photosensitive layer and the protective layer. A general binder resin is used as a main component in the another intermediate layer.
Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble vinyl butyral resin, polyvinyl butyral and polyvinyl alcohol. As a method for forming the another intermediate layer, a usual coating method is adopted as described above. The thickness of the intermediate layer is 0.05 to 2μ.
m is suitable.

[0034]

EXAMPLES The present invention will be described below with reference to examples.

Example 1 3 parts by weight of an alcohol-soluble polyamide (CM-8000; manufactured by Toray) was added to methanol / n-butanol = 8/2.
The mixture was heated and dissolved in 100 parts by weight of a mixed solvent (vol ratio) to prepare an intermediate layer coating liquid. Apply this to a 0.2 mm thick aluminum plate (A1080; (Sumitomo Light Metal Co., Ltd.), 10
It was dried at 0 ° C. for 20 minutes to form an intermediate layer having a thickness of 0.1 μm. Next, butyral resin (XYHL; UCC)
3 parts by weight was dissolved in 150 parts by weight of cyclohexanone, 6 parts by weight of the disazo pigment of Exemplified Compound (1) -24 was added thereto, and dispersed by a ball mill for 120 hours. Further, 300 parts by weight of cyclohexanone was added and dispersed for 3 hours to obtain a coating liquid for a charge generation layer containing a disazo pigment (A
Liquid). Furthermore, butyral resin (XYH
L; UCC) 3 parts by weight are dissolved in 150 parts by weight of cyclohexanone, and X type metal-free phthalocyanine (81
20B; manufactured by Dainippon Ink and Chemicals, Inc.) 6 parts by weight, and dispersed by a ball mill for 120 hours. Further, 300 parts by weight of cyclohexanone was added and dispersed for 3 hours to obtain a charge generation layer coating solution containing an X-type metal-free phthalocyanine (B
Liquid). The liquids A and B prepared as described above were mixed in equal amounts with stirring to prepare a coating liquid for the charge generation layer of the present invention. The coating liquid for the charge generation layer thus obtained is
It was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a charge generation layer having a film thickness of 0.25 μm. Next, 8 parts by weight of a charge transporting substance represented by the following structural formula (X), 10 parts by weight of a polycarbonate resin (Z-200; manufactured by Mitsubishi Gas Chemical Co., Inc.), and silicone oil (KF-50; manufactured by Shin-Etsu Chemical Co., Ltd.) 0.00
2 parts by weight was dissolved in 85 parts by weight of tetrahydrofuran to prepare a charge transport layer coating liquid. The charge-transporting layer coating liquid thus obtained is applied onto the charge-generating layer,
After drying for 20 minutes, a charge transport layer having a film thickness of 20 μm was formed to obtain the electrophotographic photosensitive member of Example 1.

[Chemical 10]

Examples 2 and 3 In the same manner as in Example 1 except that the exemplified compounds (1) -29 and (1) -30 were used as the disazo pigment, the electrophotographic sensitizations of Examples 2 and 3 were performed. Created the body.

Comparative Example 1 An electrophotographic photosensitive member of Comparative Example 1 was prepared in the same manner as in Example 1 except that the charge generation layer was formed only by the coating liquid containing the X-type metal-free phthalocyanine. .

Comparative Example 2 In Example 1, the charge generation layer was formed by using the exemplified compound (1) -2.
An electrophotographic photoreceptor of Comparative Example 1 was prepared in the same manner as in Example 1 except that only the coating liquid containing the disazo pigment of 4 was formed.

Comparative Examples 3 and 4 Example 2 is different from Examples 2 and 3 except that the charge generation layer is formed only by the coating liquid containing the disazo pigment of Exemplified Compounds (1) -29 and (1) -30. And 3
Electrophotographic photoreceptors of Comparative Examples 3 and 4 were prepared in the same manner as in.

The electrostatic characteristics of the electrophotographic photosensitive member obtained as described above were evaluated in a dynamic mode using EPA-8100 (manufactured by Kawaguchi Denki Seisakusho). First, after the corona discharge of 16 kV is performed on the photoconductor for 5 seconds to be negatively charged,
When dark-decayed and the surface potential became -800V, 500nm, 600nm, 7 using a bandpass filter.
The light separated into each of 00 nm and 780 nm was exposed, and the exposure amount E1 / 2 (μJ / cm ² ) required for the surface potential to be attenuated to -400 V was measured. The evaluation results are shown in Table 2.

[0041]

[Table 2] * No light attenuation

Example 4 First, an intermediate layer was formed on an aluminum plate in the same manner as in Example 1. Next, butyral resin (XYHL; UCC)
3 parts by weight was dissolved in 150 parts by weight of cyclohexanone, 3.0 parts by weight of the disazo pigment of Exemplified Compound (1) -24 and 2.5 parts by weight of X-type metal-free phthalocyanine were added, and dispersed by a ball mill for 120 hours. Further, 300 parts by weight of cyclohexanone was added and dispersed for 3 hours to prepare a charge generation layer coating liquid. The charge generation layer coating liquid thus obtained was applied onto the intermediate layer and dried at 130 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.25 μm. next,
7 parts by weight of a charge transport material having the following structural formula (XI), 10 parts by weight of a polycarbonate resin (Z-200; manufactured by Mitsubishi Gas Chemical Co., Inc.), silicone oil (KF-50; manufactured by Shin-Etsu Chemical Co., Ltd.)
0.002 parts by weight was dissolved in 85 parts by weight of tetrahydrofuran to prepare a coating liquid for charge transport layer. The thus-obtained charge transport layer coating liquid is applied onto the charge generation layer, and 1
It was dried at 30 ° C. for 20 minutes to form a charge transport layer having a film thickness of 20 μm, and the electrophotographic photosensitive member of Example 4 was obtained.

[Chemical 11]

Examples 5 and 6 In the same manner as in Example 4 except that the exemplified compounds (1) -29 and (1) -30 were used as the disazo pigment, the electrons of Examples 5 and 6 were used. A photographic photoreceptor was created.

Example 7 An electrophotographic photosensitive member of Example 7 was prepared in the same manner as in Example 4 except that the charge generation layer was formed as follows. First, 3.0 parts by weight of the disazo pigment of Exemplified Compound (1) -24 and 2.5 parts by weight of X-type metal-free phthalocyanine were placed in a ball mill and dry milled for 4 hours. Next, butyral resin (XYHL; UCC) 3
A solution obtained by dissolving 150 parts by weight of cyclohexanone in 150 parts by weight was added and dispersed by a ball mill for 72 hours. Further, 300 parts by weight of cyclohexanone was added and dispersed for 3 hours to prepare a charge generation layer coating liquid. The charge generation layer coating liquid thus obtained is applied onto the intermediate layer at 130 ° C.
After drying for 10 minutes, a charge generation layer having a film thickness of 0.25 μm was formed.

Comparative Example 5 Comparative Example 5 was carried out in the same manner as in Example 4 except that a polycyclic quinone pigment represented by the following structural formula (XII) was used in place of the disazo pigment of Exemplified Compound (1) -24. The electrophotographic photosensitive member of No. 5 was prepared.

Comparative Examples 6, 7 and 8 In Example 4, instead of the disazo pigment of Exemplified Compound (1) -24, the following structural formulas (XIII), (XIV) and (X
Electrophotographic photoreceptors of Comparative Examples 6, 7 and 8 were prepared in the same manner as in Example 4 except that the disazo pigment shown in V) was used.

[Chemical 12]

[Chemical 13]

[Chemical 14]

[Chemical 15] Examples 4 to 7 and Comparative Example 5 obtained as described above
The electrostatic characteristics of the electrophotographic photosensitive members # 8 to # 8 were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Table 3]

Examples 8, 9 and 10 Example 4, on a φ80 mm aluminum cylinder.
An intermediate layer, a charge generation layer and a charge transport layer were sequentially formed in the same manner as in 5 and 6 to prepare electrophotographic photoreceptors of Examples 8, 9 and 10.

Comparative Examples 9, 10 and 11 Comparative Example 5, on an φ80 mm aluminum cylinder.
An intermediate layer, a charge generation layer and a charge transport layer were sequentially formed in the same manner as 6 and 7 to prepare electrophotographic photoreceptors of Comparative Examples 9, 10 and 11.

A digital copying machine equipped with a halogen lamp that cuts light of 650 nm or more using the electrophotographic photoreceptors of Examples 8, 9 and 10 and Comparative Examples 9, 10 and 11 obtained as described above as a charge eliminating light source. (Imagio MF5
30; manufactured by Ricoh) and evaluated for electrophotographic characteristics.
The charging voltage, the laser light amount (wavelength 780 nm), and the static elimination light amount are the charge potential (Vd), the post-exposure potential (Vl), and the static elimination potential (V) when the respective electrophotographic photoconductors are mounted.
r) was adjusted to be around −850V, −130V, and −50V, respectively. Using the digital copying machine adjusted in this way, the initial charging potential (Vd) and the post-exposure potential (Vd
1), potential after static elimination (Vr), charge potential (Vd) after continuous copying of 2,000 sheets, potential after exposure (Vl), potential after static elimination (Vr) were measured. The results are shown in Table 4.

[Table 4]

Example 11 First, in the same manner as in Example 1, an aluminum vapor deposition P having a thickness of 75 μm was formed.
An intermediate layer of CM-8000 on ET (film thickness 0.1 μm
m) was created. Next, 1 part by weight of X-type metal-free phthalocyanine, 1 part by weight of a disazo pigment of Exemplified Compound (1) -24 and 100 parts by weight of tetrahydrofuran were dispersed in a sand mill for 2 hours, and this dispersion and the structural formula (X) are shown. 7 parts by weight of a charge transport material and a polycarbonate resin (Z-200:
(Mitsubishi Gas Chemical Co., Ltd.) 10 parts by weight of tetrahydrofuran 1
The solution dissolved in 100 parts by weight was mixed to prepare a photosensitive layer coating solution. The photosensitive layer coating liquid thus obtained was coated on the intermediate layer and dried at 130 ° C. for 15 minutes to form a photosensitive layer having a film thickness of 20 μm, whereby an electrophotographic photosensitive member of Example 11 was obtained.

Examples 12 and 13 Examples of the disazo pigment in Example 11 are compound (1)-
The electrophotographic photosensitive members of Examples 12 and 13 were prepared in the same manner as in Example 11 except that the electrophotographic photosensitive members were replaced with 29 and (1) -30.

Comparative Examples 12 and 13 The disazo pigments of Example 11 were prepared according to the structural formula (XII
Electrophotographic photoreceptors of Comparative Examples 12 and 13 were prepared in the same manner as in Example 11 except that the disazo pigments shown in I) and (XIV) were used.

Examples 11 to 1 thus obtained
3, the electrostatic characteristics of the electrophotographic photosensitive members of Comparative Examples 12 and 13 were evaluated in the same manner as in Example 1 except that the corona discharge voltage was set to +7 kV and the potential to be evaluated was set to plus. The evaluation results are shown in Table 5.

[Table 5]

[0054]

As is clear from the above results, the electrophotographic photosensitive member of the present invention is panchromatic and has extremely high sensitivity over a wide wavelength range from the visible region to the near infrared region, and at the same time, in continuous use. The potential stability is also excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating the layer structure of an electrophotographic photoreceptor of the present invention.

FIG. 2 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

FIG. 5 is a cross-sectional view illustrating the layer structure of the electrophotographic photosensitive member of the present invention.

Claims (3)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains an X-type metal-free phthalocyanine pigment and a disazo pigment represented by the following general formula (I). An electrophotographic photosensitive member. [Chemical 1] (In the formula, A and B represent coupler residues having different structures.) 2. The photosensitive layer has a charge generation layer and a charge transport layer, and at least the charge generation layer contains an X-type metal-free phthalocyanine pigment and the disazo pigment represented by the general formula (I). 1. The electrophotographic photosensitive member according to 1. 3. The electrophotographic photoreceptor according to claim 1, wherein the disazo pigment is a compound represented by the following formula (II). [Chemical 2]