JPH0690524B2 - Optical semiconductor material and electrophotographic photoreceptor using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Object of the Invention" (Field of Industrial Application) The present invention relates to a photo-semiconductor material useful for an electrophotographic photoreceptor or the like using phthalocyanine containing vanadium as a central metal. Speaking of which, in addition to excellent exposure sensitivity characteristics and wavelength characteristics, an electrophotographic photosensitive member using a phthalocyanine containing amorphous vanadium, which is a fine particle having an excellent dispersibility and a primary particle size of 0.2 micron or less, as a charge generating agent .

(Prior Art) Conventionally, as a photoreceptor of an electrophotographic photoreceptor, a photoreceptor using an inorganic photoconductor such as selenium, selenium alloy, zinc oxide, cadmium sulfide, and titanium oxide has been mainly used. In recent years, the development of semiconductor lasers has been remarkable, and small, stable laser oscillators have become available at low cost, and they are beginning to be used as light sources for electrophotography. However, using a semiconductor laser that oscillates short-wavelength light in these devices has many problems in terms of life, output, and the like. Therefore, it is unsuitable to use the conventionally used material having sensitivity in the short wavelength region for semiconductor lasers, and it becomes necessary to study the material having high sensitivity in the long wavelength region (780 nm or more). It was Recently, research has been actively conducted on a laminated organic photoconductor in which an organic material, particularly phthalocyanine, which is expected to have sensitivity in a long wavelength region, is used and laminated. For example, as a divalent metal phthalocyanine,
ε-type copper phthalocyanine (ε-CuPc) and τ-type metal-free phthalocyanine (τ-H2Pc) have sensitivity in the long wavelength region, and trivalent and tetravalent metal phthalocyanines include chloroaluminum phthalocyanine (AlPcCl) and chloroaluminum phthalocyanine. Chloride (ClAlPcCl), titanyl phthalocyanine (TiOPc) or chloroindium phthalocyanine (InPcCl) is vapor-deposited, and then contacted with a vapor of a soluble solvent for long wavelength and high sensitivity (JP-A-57-394).
84, Japanese Patent Laid-Open No. 59-166959) and T as a Group IV metal.
A method of subjecting phthalocyanine containing i, Sn and Pb to long wavelength treatment using various substituents, derivatives or shift agents such as crown ethers (Japanese Patent Application Nos. 59-36254 and 59-204045). ) Etc.

LEDs have also been put into practical use as digital light sources for printers. Although LEDs in the visible light range are also used, the ones that have been put into practical use have an oscillation wavelength of 650 nm or more, typically 670 nm. Azo compounds, perylene compounds, selenium, zinc oxide, etc. cannot be said to have sufficient photosensitivity around 650 nm, but phthalocyanine compounds have absorption peaks around 650 nm, so they are also effective materials for LEDs. I can expect it.

Japanese Unexamined Patent Publication No. 57-147641 describes a photoconductor using vanadyl phthalocyanine as a charge generating material.
This publication discloses a technique of pulverizing and dispersing in a solvent or an inert resin solution using a ball mill, paint conditioner, SPEX mill, etc. However, pulverization in a solution is extremely inefficient and Crushing has a problem in reproducibility. Also, in the process of synthesizing or purifying vanadyl phthalocyanine, if a solvent having a strong polarity such as alcohol is used, the crystal particles are strongly aggregated and it becomes difficult to make them into fine particles thereafter (Japanese Patent Laid-Open Nos. 57-147641 and Sho. 61-28557 publication).

As described above, conventionally reported vanadyl phthalocyanine is often agglomerated particles that are strongly aggregated, many impurities are contained between the aggregated particles, and crystals always grow during crystallization. Due to its large diameter, the charge generation layer vapor-deposited and dispersion-coated using them lacked dispersion stability and caused deterioration of coatability. As a result, it was difficult to obtain a uniform charge generation layer, and it was difficult to obtain a beautiful image.

In the case of these crystalline phthalocyanines, the light absorption efficiency is not sufficient, the carrier generation efficiency of the charge generation layer is reduced, the injection efficiency of carriers into the charge transfer layer is reduced, and the deterioration resistance and resistance to repeated use over a long period of time It had a drawback that it did not fully satisfy various electrophotographic characteristics such as printability and image stability.

(Problems to be Solved by the Invention) An object of the present invention is to improve the dispersibility of a pigment so as to obtain a uniform charge generation layer having a very good dispersibility and no defects in the coating film. In addition to excellent exposure sensitivity characteristics and wavelength characteristics, deterioration resistance characteristics during repeated use over a long period of time,
This is to obtain printing durability and image stability.

[Structure of Invention] (Means and Actions for Solving Problems) The present invention provides a phthalocyanine having a central nucleus of oxyvanadium or vanadium halide, which may have a benzene ring of phthalocyanine substituted with a halogen atom. A photo-semiconductor using a non-crystalline vanadium phthalocyanine which does not show a strong X-ray diffraction peak of the phthalocyanine obtained by treating with an acid pasting method or an acid slurry method and then pulverizing with a mechanical treatment method. An electrophotographic photosensitive member comprising a material, and further a charge generating agent and a charge transfer agent, wherein the charge generating agent is the phthalocyanine.

Furthermore, it is a minute primary particle having a particle size of 0.2 micron or less, and an electrophotographic photoreceptor can be obtained by using a charge generating agent composed of non-crystalline vanadium phthalocyanine. The vanadium-based phthalocyanine of the present invention is a phthalocyanine containing vanadium metal and oxygen as a central nucleus, or oxyvanadium phthalocyanine (VOPc), vanadium phthalocyanine dichloride (VCl2Pc), or a benzene ring of the above phthalocyanine. Indicates one or two or more halogenated compounds. Phthalocyanine is generally a phthalodinitrile method in which phthalodinitrile and a metal chloride are heated and melted or heated in the presence of an organic solvent, and phthalic anhydride is heated and melted with urea and a metal chloride or heated in the presence of an organic solvent. There are, but not limited to, the Weyler method, the method of reacting cyanobenzamide with a metal salt at a high temperature, and the method of reacting dilithium phthalocyanine with a metal salt. Further, as the organic solvent, α-chloronaphthalene, β
-Chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol,
It is desirable to use a reaction-inert high boiling point solvent such as dialkyl ether, quinoline, sulfolane, or dichlorobenzene.

The vanadium-containing phthalocyanine used in the present invention is a Moser and Thomas "Phthalocyamine Compound".
s ") and other known methods and those obtained by the appropriate methods described above are used to synthesize the compound with acid, alkali, acetone,
Methyl ethyl ketone, tetrahydrofuran, pyridine,
It is obtained by washing with quinoline, sulfolane, α-chloronaphthalene, toluene, xylene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, trichloropropane, N, N'-dimethylformamide, etc., and can be further purified by sublimation. . In the phthalocyanine compound containing vanadium synthesized by the above method, the particles are strongly aggregated and crystallized to form secondary particles of 1 to 2 microns, and large particles of 10 microns or more. This agglomeration is extremely strong, and even if a grinding means such as a sand mill, a ball mill, an attritor, or a roll mill is used, it cannot be easily made into fine particles in a short time.

In the electrophotographic photoreceptor containing the above-mentioned crystalline coarse secondary particles in the charge generation layer, the number of carriers generated decreases and the photosensitivity decreases due to the decrease in the light absorption efficiency. In addition, since the charge generation layer is non-uniform, the carrier injection efficiency into the charge transfer layer is also reduced, and as a result, the electrostatic characteristics cause an induction phenomenon, a decrease in surface potential, and potential stability during repeated use. A phenomenon that is unfavorable in terms of the sensitivity of the photoreceptor, such as poor image quality, occurs. Also, the image lacks homogeneity and causes minute defects. Particle size of fine primary particles of the present invention
The charge generation layer using non-crystalline vanadium phthalocyanine of 0.2 micron or less is a uniform layer with high light absorption efficiency, there are few voids between particles in the charge generation layer, and potential stability during repeated use. , Characteristics as an electrophotographic photosensitive member such as prevention of increase in bright area potential, and reduction of image defects,
It is possible to obtain an electrophotographic photosensitive member that satisfies many requirements such as printing durability.

The vanadium-based phthalocyanine of the present invention can be obtained by a single chemical method or mechanical method, but more preferably, by each method, a substance having weak cohesive force is prepared and further loosened by various methods. It can be obtained by combination.

For example, extremely fine primary particles can be obtained by weakening the agglomeration between particles by a method such as an acid pasting method or an acid slurry method, and then grinding by a mechanical treatment method. Equipment used during grinding is a kneader, Banbury mixer, attritor, edge runner mill, roll mill, ball mill, sand mill, SPE.
Examples include, but are not limited to, X mills, homomixers, dispersers, agitators, jaw crushers, stamp mills, cutter mills, and micronizers. The acid-patting method, which is well known as a chemical treatment method, is a method in which pigments are dissolved or sulphated in 95% or more sulfuric acid and poured into water or ice water for reprecipitation. Is preferably kept at 5 ° C. or lower, and sulfuric acid is slowly poured into water that is stirred at a high speed, so that fine particles can be obtained under better conditions.

In addition, there are a method of directly grinding the crystalline particles with a mechanical treatment device for a very long time, a method of treating the particles obtained by the acid pasting method with the above-mentioned solvent and the like, and then immediately grinding. It is also possible to obtain a very small amount of amorphous primary particles.

However, following the chemical treatment of the crystalline particles, the fine particles obtained by the mechanical treatment are purified by the solvent used for washing the above-mentioned compound, and then the chemical treatment is performed again. Needless to say, it is desired to improve the degree of purification and to make the particles finer by repeating appropriate treatments many times.

The vanadium-containing phthalocyanine compound obtained by the present invention is an amorphous particle having no definite interplanar spacing from which the diffraction angle cannot be read. The amorphous particles can also be obtained by sublimation. For example, it can be obtained by heating vanadium-based phthalocyanine, which is a raw material obtained by various methods, under vacuum to sublimate it by heating it to 500 ° C. to 600 ° C. and promptly depositing it on the substrate. The vanadium phthalocyanine obtained by these is in an amorphous state and becomes fine particles depending on the deposition conditions, but more preferably fine particles made by mechanical grinding. In addition, the absorption peak of the film obtained by sublimation by this treatment is around 750 nm, while that after mechanical treatment is 830 nm.
Changes to a characteristic suitable for semiconductor lasers.

The tourist body is preferably a conductive substrate on which an undercoat layer, a charge generation layer, and a charge transfer layer are stacked in this order, but an undercoat layer, a charge transfer layer, and a charge generation layer are stacked in this order. It is also possible to disperse and coat a charge generating agent and a charge transfer agent with an appropriate resin on the undercoat layer. By coating one or more of these vanadium-based phthalocyanines as a charge generating agent on a suitable binder and a substrate, a charge generating layer having extremely good dispersibility and extremely high light absorption efficiency can be obtained. Further, although it is known that the charge generation layer is obtained by vapor deposition, the material obtained by the present invention can be vaporized very efficiently because it is made into fine particles and impurities existing between the particles are removed. It is also effective as a material.

Coating is performed using a spin coater, applicator, spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, bead coater device, and drying is preferably heat drying at 40-200 ℃ for 10 minutes. Perform under static or blown conditions for up to 6 hours. After drying, it is applied to a film thickness of 0.01 to 5 μm, preferably 0.1 to 1 μm.

The binder that can be used to form the charge generation layer by coating can be selected from a wide range of insulating resins.
It can be selected from organic photoconductive polymers such as N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.),
Polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin, silicone resin, polystyrene, polyketone, polyvinyl chloride, vinyl chloride-vinyl chloride copolymer Insulating resins such as coalesce, polyvinyl acetal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinylpyrrolidone can be mentioned. The amount of the resin contained in the charge generation layer is 100% by weight or less, preferably 40% by weight or less. These resins may be used alone or in combination of two or more. The solvent that dissolves these resins varies depending on the type of the resin, and it is preferable to select a solvent that does not affect the charge generation layer or the undercoat layer described below during coating.
Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene, and dichlorobenzene,
Acetone, methyl ethyl ketone, cyclohexanone, and other ketones, methanol, ethanol, isopropanol, and other alcohols, ethyl acetate, methyl cellosolve, and other esters, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, trichloroethylene, and other aliphatic halogenated carbons Hydrogen, tetrahydrofuran, dioxane, ethylene glycol mono, ethers such as methyl ether, N, N-dimethylformamide, N, N
-Amids such as dimethylacetamide and sulfoxides such as dimethylsulfoxide are used.

The charge transfer layer is formed by dissolving and dispersing the charge transfer agent alone or in the binder resin. The charge transfer material includes an electron transfer material and a hole transfer material, and the electron transfer material includes
Chloranil, bromoanil, tetracyanoethylene,
Tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4, There are electron-withdrawing substances such as 5,7-tetranitroxanthone and 2,4,8-trinitrothioxanthone and polymers obtained by polymerizing these electron-withdrawing substances.

Examples of the hole transfer material include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-phenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-diphenylhydrazino-3-. Methylidene-9
-Ethylcarbazole, N, N-diphenylhydrazino-3
-Methylidene-10-ethylphenothiazine, N, N-diphenylhydrazino-3-methylidene-10-ethylphenoxazine, P-diethylaminobenzaldehyde-N, N-diphenylhydrazone, P-diethylaminobenzaldehyde-N -Α-naphthyl-N-phenylhydrazone, P-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, 2-methyl-4-dibenzylaminobenzaldehyde-1'-ethyl-1'-benzothiazolylhydrazone, 2
-Methyl-4-dibenzylaminobenzaldehyde-
1'-propyl-1'-benzothiazolylhydrazone, 2
-Methyl-4-dibenzylaminobenzaldehyde-
1 ', 1'-diphenylhydrazone, 9-ethylcarbazole-3-carboxaldehyde-1'-methyl-1'-phenylhydrazone, 1-benzyl-1,2,3,4-tetrahydroquinoline-6-carboxaldehyde -1 ', 1'-diphenylhydrazone, 1,3,3-trimethylindolenine-
hydrazones such as ω-aldehyde-N, N-diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2.5-bis (P-diethylaminophenyl) -1.3.4-oxadi Azole, 1
-Phenyl-3- (P-diethylaminostyryl) -5
-(P-diethylaminophenyl) pyrazoline, 1- [quinolyl (2)]-3- (P-diethylaminostyryl)
-5- (P-diethylaminophenyl) pyrazoline, 1-
[Pyridyl (2)]-3- (P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [6-methoxy-pyridyl (2)]-3- (P-
Diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [pyridyl (3)]-3-
(P-Diethylaminostyryl) -5- (P-diethylaminosphenyl) pyrazoline, 1- [levidyl (2)]
-3- (P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (P-diethylaminostyryl) -4-
Methyl-5- (P-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (α-methyl-P-diethylaminostyryl) -5- (P-diethylaminophenyl) pyrazoline, 1-phenyl- 3- (P-diethylaminostyryl) -4-methyl-5- (P-diethylaminophenyl) pyrazoline, 1-phenyl-3- (α-benzyl-P-diethylaminostyryl) -5- (P-diethylaminophenyl) -6-Pyrazoline, spiropyrazoline and other pyrazolines, 2- (P-diethylaminostyryl) -6-diethylaminobenzoxazole, 2-
Oxazole compounds such as (P-diethylaminophenyl) -4- (P-diethylaminophenyl) -5- (2-chlorophenyl) oxazole, α-phenyl-4-
Stilbene compounds such as N, N-diphenyl-amino-stilbene, thiazole compounds such as 2- (P-diethylaminostyryl) -6-diethylaminobenzothizole,
Triarylmethane compounds such as bis (4-diethylamino-2-methylphenyl) -phenylmethane, 1,1-bis (4-N, N-diethylamino-2-methylphenyl)
Polyarylalkanes such as heptane, 1,1,2,2-tetrakis (4-N, N-dimethylamino-2-methylphenyl) ethane, triphenylamine, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, There are polyvinyl acridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole formaldehyde resin and the like.

In addition to these organic charge transfer materials, inorganic materials such as selenium, selenium-telluramorphous silicon, and cadmium sulfide can also be used.

Further, these charge transfer substances can be used alone or in combination of two or more. Resins used for the charge transfer layer are silicone resin, ketone resin, polymethylmethacrylate, polyvinyl chloride, acrylic resin, polyarylate, polyester, polycarbonate, polystyrene,
Acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral,
Insulating resins such as polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, poly-N-vinylcarbazole, polyvinylanthracene,
There are polyvinylpyrene and the like.

The coating method is spin coater, applicator, spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, bead coater, and the film thickness after drying is 5 to 50 microns, preferably 10 to It is good that it is coated to 20 microns. In addition to each of these layers, an undercoat layer may be provided on the conductive substrate for the purpose of preventing deterioration of charging property and improving adhesiveness. As the undercoat layer, nylon 6,
Nylon 66, Nylon 11, Nylon 610, Copolymer Nylon,
Alcohol-soluble polyamides such as alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, gelatin, polyurethane, polyvinyl butyral and metal oxides such as aluminum oxide are used. It is also possible to adjust the conductivity by incorporating conductive particles such as metal oxide or carbon black into the resin.

The material of the present invention has an absorption peak at a wavelength of 800 mm or more,
It is suitable not only as an electrophotographic photoreceptor for copying machines and printers but also as an absorbing material for solar cells, photoelectric conversion elements and optical disks.

Examples of the present invention will be described below. In the examples, “part” means “part by weight”.

Example 1 25.6 parts of o-phthalodinitrile and 9.1 parts of vanadium pentoxide were reacted by heating in 50 parts of α-chlornaphthalene at 200 ° C. for 2 hours, the solvent was removed by steam distillation, and a 2% aqueous hydrochloric acid solution was added. % Aqueous sodium hydroxide solution, washed with acetone and dried to obtain 24.3 parts of vanadyl phthalocyanine (VOPc). Add 2 parts of this vanadyl phthalocyanine to 98% at 5 ℃.
Dissolve little by little in 40 parts of sulfuric acid, and stir the mixture for about 1 hour while keeping the temperature below 5 ° C. Then, the sulfuric acid solution is slowly poured into 400 parts of ice water stirred at high speed, and the precipitated crystals are filtered. The crystals were washed with distilled water until no acid remained, purified with acetone, and then dried to obtain 1.8 parts of vanadyl phthalocyanine. Next, 1 part of this vanadyl phthalocyanine was crushed with a ball mill for 24 hours.

The vanadyl phthalocyanine thus obtained is composed of fine primary particles of 0.2 μm or less and has no strong diffraction peak as shown in the X-ray diffraction diagram of FIG.

On a 75 micron thick sheet of aluminum vapor-deposited on polyethylene terephthalate film, zinc oxide (SAZE Chemical SAZE
X # 2000) 0.3 parts, polyvinyl alcohol (saponification degree 86-
89%) 9.7 parts are mixed, 500 parts of ethanol and a coating solution dispersed in a ball mill for 3 hours are applied with a wire bar, and the mixture is applied at 70 ° C. for 3 hours.
After heat-drying for a period of time, a sheet with an undercoat layer of 0.5 micron was obtained.

2 parts of vanadyl phthalocyanine obtained by the above method and 97 parts of dioxane and 1 part of phenoxy resin (PK manufactured by Union Carbide
HH) was added to the solution and dispersed by a ball mill for 2 hours. This dispersion was applied on the undercoat layer and dried at 100 ° C for 2 hours to form a 0.3 micron charge generation layer, and then 1-benzyl-1,2,3,4- Tetrahydroquinoline-6-carboxaldehyde-1 ', 1'-diphenylhydrazone 10 parts, polyester resin (Voyron 200 made by Toyobo Co., Ltd.) 10 parts were dissolved in 100 parts by weight of methylene chloride, applied on the charge generation layer, dried, A 15 micron charge transfer layer was formed to obtain an electrophotographic photoreceptor, and its characteristics were measured.

The absorption spectrum of vanadyl phthalocyanine obtained in this example is shown in FIG. 2 (solid line).

Example 2 An electrophotographic photosensitive member was similarly prepared by using 2-methyl-4-dibenzylaminobenzaldehyde-1-ethyl-1'-phthalazinylhydrazone instead of the charge transfer agent of Example 1, and The properties were measured.

Example 3 Instead of the charge transfer agent of Example 1, 2-methyl-4-dibenzylaminobenzaldehyde-1'-propyl-1 '
An electrophotographic photoreceptor was similarly prepared using benzothiazolyl hydrazone, and its characteristics were measured.

Example 4 25.6 parts of o-phthalodinitrile and 9.1 parts of vanadium pentoxide were heated in 50 parts of α-chlornaphthalene at 200 ° C. for 2 hours, after the reaction, the solvent was removed by steam distillation, and the mixture was purified with a 2% hydrochloric acid aqueous solution. After that, it was dried to obtain 21.6 parts of vanadium phthalocyanine dichloride (VPcCl2). An electrophotographic photosensitive member was prepared using the material obtained by subjecting this vanadium phthalocyanine dichloride to acid pasting and ball mill dispersion in the same manner as in Example 1, and its characteristics were measured.

Example 5 25.6 parts of o-phthalodinitrile and 9.1 parts of vanadium pentoxide were heated at 250 ° C. for 2 hours, and after the reaction, the product was purified with a 2% hydrochloric acid aqueous solution and then with acetone, and then dried, and monochlorovanadium phthalocyanine dichloride ( ClVPcCl2) 23.7 parts was obtained. An electrophotographic photoreceptor was prepared using the material obtained by subjecting this monochlorovanadium phthalocyanine dichloride to acid pasting and ball mill dispersion in the same manner as in Example 1 and measuring its characteristics.

The absorption spectrum of the monochlorovanadium phthalocyanine dichloride obtained in this example is shown in FIG. 2 (dotted line).
Shown in.

Example 6 10 parts of vanadyl phthalocyanine synthesized and purified by the method of Example 1 was heated and sublimated at 550 ° C. under a vacuum condition of 10 ⁻⁵ Torr, and deposited on a cooled substrate. The precipitate was taken out and pulverized with a ball mill for 50 hours to obtain 7.9 parts of vanadium phthalocyanine composed of fine primary particles. Using this material, an electrophotographic photosensitive member was prepared in the same manner as in Example 1, and its characteristics were measured.

Comparative Example 1 25.6 parts of o-phthalodinitrile and 9.1 parts of vanadium pentoxide were heated in 50 parts of α-chlornaphthalene at 200 ° C. for 2 hours, after the reaction, the solvent was removed by steam distillation, and a 2% aqueous hydrochloric acid solution was added.
Then, the product was purified with a 2% aqueous sodium hydroxide solution, washed with acetone and dried to obtain 24.6 parts of vanadyl phthalocyanine.

The vanadyl phthalocyanine thus obtained consists of aggregated and crystalline particles of 1 micron or more. Using this vanadyl phthalocyanine, an electrophotographic photosensitive member was prepared in the same manner as in Example 1 and its characteristics were measured.

The electrophotographic photoconductor thus prepared was corona charged at −5.4 KV by an electrostatic copying paper tester SP-428 manufactured by Kawaguchi Electric Co., Ltd., and was charged by irradiating surface charge (Vo) and 51ux white light (W). The half-white light exposure sensitivity (E1 / 2) was examined from the time when the amount decreased to 1/2. Also, the evaluation of the repeatability is −5.
The surface potential, residual potential, and deterioration of sensitivity were measured by repeating charging in the order of 4 KV and corona linear velocity of 20 m / min, leaving in the dark for 2 seconds, and exposing at 51ux for 3 seconds. The results are shown in Table 1. The residual potential (VR) is the potential after 3 seconds of light irradiation.

Further, the photoconductors prepared in this example and the comparative example were attached to a drum of an electrophotographic copying machine having a corona charger, an exposure part, a development part, a transfer charging part, a charge removal exposure part and a cleaner. The light section potential of this copier was set to -650V and the dark section potential was set to -150V, and after repeated durability test of 5000 sheets,
The images were compared.

As a result of the durability test of 5,000 sheets, in Examples 1 to 6 in which the charge generation layer was formed by using the fine primary particles, a beautiful image was obtained after the durability test of 5,000 sheets, whereas in Comparative Example 1, white spots were generated. There were many white spots on the image, and the number of white spots became larger and larger as the durability test was repeated, and a sufficient image could not be obtained.

After charging the photoreceptor to −5.4KV corona using an electrostatic charging tester, a 500W xenon lamp was used as the light source and a monochromator (manufactured by Jobin Yvon) was used to illuminate it as monochromatic light. The decay was measured.

When using 800 nm monochromatic light, the half-exposure dose is 0.50 μJ / cm ²
It was 0.65 μJ / cm ² for 650 nm monochromatic light. It can be seen that this photoreceptor has high sensitivity in the oscillation wavelength region of semiconductor lasers and LEDs.

[Advantages of the Invention] The present invention can be achieved with conventional pigments composed of agglomerated particles by developing and using a phthalocyanine compound containing vanadium composed of non-aggregate primary particles of 0.2 micron or less. It was possible to obtain a very uniform charge generation layer, which was not possible, and sensitivity and repeatability were improved.
It has become possible to create electrophotographic photoreceptors that provide extremely beautiful images. Also, since it has a long wavelength region of 750 mm or more and high sensitivity at 650 nm, it is optimal as a photoconductor for printers using semiconductor lasers and LEDs as light sources.

[Brief description of drawings]

FIG. 1 shows the X-ray diffraction diagram of vanadyl phthalocyanine of Example 1 of the present invention, and FIG. 2 shows the absorption spectra of vanadyl phthalocyanine of Example 1 and Example 5, respectively.

Claims (5)

[Claims] 1. A phthalocyanine having a central nucleus of oxyvanadium or vanadium halide, which may have a benzene ring of phthalocyanine substituted with a halogen atom, which is treated by an acid pasting method or an acid slurry method, and An optical semiconductor material, characterized in that the phthalocyanine obtained by grinding by a mechanical treatment method is made of an amorphous vanadium phthalocyanine which does not show a strong X-ray diffraction peak. 2. The photosemiconductor material according to claim 1, which is a vanadium phthalocyanine whose primary particle system is 0.2 micrometer or less. 3. An electrophotographic photoreceptor comprising a charge generating agent and a charge transfer agent, wherein the charge generating agent may have a benzene ring of phthalocyanine substituted with a halogen atom, the central nucleus of which is oxyvanadium or halogenated. An electrophotographic photosensitive member comprising phthalocyanine which is vanadium and which is a non-crystalline vanadium phthalocyanine which does not show a strong X-ray diffraction peak. 4. A charge transfer agent comprising the following three general formulas [1],
The electrophotographic photosensitive member according to claim 2, which is a charge transfer layer containing at least one hydrazone compound represented by [2] or [3] as an active ingredient. (In the paper container, R ₁ , R ₂ and R ₃ represent a halogen atom, a nitro group, a cyano group, an optionally substituted alkyl group, an alkoxy group, an aryl group, an aryloxy group or an amino group, and n is Represents an integer of 0-4.) 5. The electrophotographic photosensitive member according to claim 3, which has an inorganic or organic undercoat layer on the conductive support.