JPH0529109B2 - - Google Patents

Description

[Detailed description of the invention]

"Objective of the Invention" (Industrial Application Field) The present invention relates to a photosemiconductor material useful for electrophotographic photoreceptors etc. that uses phthalocyanine containing titanium as a central metal, and more specifically, The present invention relates to an electrophotographic photoreceptor using, as a charge generating agent, phthalocyanine containing amorphous titanium in fine particles with a primary particle diameter of 0.2 microns or less, which has excellent characteristics and wavelength characteristics, and has extremely good dispersibility. (Prior Art) Conventionally, as photoreceptors for electrophotographic photoreceptors, those using inorganic photoconductors such as selenium, selenium alloys, zinc oxide, cadmium sulfide, and titanium oxide have been mainly used. In recent years, the development of semiconductor lasers has been remarkable, and small and stable laser oscillators have become available at low cost and are beginning to be used as light sources for electrophotography. However, using semiconductor lasers that emit short wavelength light in these devices has many problems in terms of lifespan, output, etc.
Therefore, the conventionally used materials sensitive in the short wavelength region are unsuitable for use in semiconductor lasers, and it has become necessary to research materials with high sensitivity in the long wavelength region. Recently, research has been actively conducted on multilayer organic photoreceptors using organic materials, especially phthalocyanine, which is expected to have sensitivity in the long wavelength region. For example, as divalent metal phthalocyanines, ε-type copper phthalocyanine (ε-cupc) and γ-type metal-free phthalocyanine (γ-H ₂ Pc) have sensitivity in the long wavelength region, and trivalent,
As the tetravalent metal phthalocyanine, chloroaluminum phthalocyanine (AlPcCl), chloroaluminum phthalocyanine chloride (ClAlPcCl), titanyl phthalocyanine (TiOPc), or chloroindium phthalocyanine (InPcCl) is deposited and then exposed to the vapor of a soluble solvent for a long time. Wavelength, method for increasing sensitivity (Unexamined Japanese Patent Publication 1983
-39484, JP-A-59-166959), phthalocyanine containing Ti, Sn, and Pb as group metals is subjected to long wavelength treatment using various substituents, derivatives, or shifting agents such as crown ethers. There are methods (Japanese Patent Application No. 59-36254, Japanese Patent Application No. 59-204045), etc. However, all phthalocyanines that have been reported so far are in the "crystalline form" with strong X-ray diffraction peaks.
This crystalline phthalocyanine is limited to large particles, and is often tightly aggregated, lumpy particles, and contains many impurities between the aggregated particles.Also, because crystals always grow during crystallization, pigment Due to their large particle size, charge generation layers formed by vapor deposition and dispersion coating lack dispersion stability, resulting in a decrease in coatability. As a result, it was difficult to obtain a homogeneous charge generation layer, and it was difficult to obtain a beautiful image. For example, JP-A-59-49544 and JP-A-59-166959.
As is clear from the X-ray diffraction diagram shown in the publication, the titanyl phthalocyanine (oxytitanium phthalocyanine) used here is a crystalline phthalocyanine and exhibits a clear and strong X-ray diffraction peak. Furthermore, in the case of these crystalline phthalocyanines, the light absorption efficiency is insufficient, resulting in a decrease in the carrier generation efficiency of the charge generation layer, a decrease in the carrier injection efficiency into the charge transfer layer, and furthermore, deterioration resistance during repeated use over a long period of time. It had the disadvantage that various electrophotographic properties such as printing durability and image stability were not fully satisfied. (Problems to be Solved by the Invention) The object of the present invention is to improve the dispersibility of pigments to obtain a homogeneous charge generation layer with extremely good dispersibility and no defects in the coating film, thereby providing a dense image. In addition to excellent exposure sensitivity characteristics and wavelength characteristics, the objective is to obtain deterioration resistance, printing durability, and image stability during repeated use over a long period of time. "Structure of the Invention" (Means and Effects for Solving Problems) The present invention provides a phthalocyanine in which the benzene ring of the phthalocyanine may be substituted with a halogen atom, and in which the central nucleus is oxytitanium or titanium halide, The phthalocyanine is an optical semiconductor material using an amorphous titanium-based phthalocyanine that does not show a strong X-ray diffraction peak, and furthermore, an electrophotographic photoreceptor using a charge generating agent and a charge transfer agent. This is an electrophotographic photoreceptor in which the generator is the phthalocyanine. Furthermore, an electrophotographic photoreceptor can be obtained using a charge generating agent made of amorphous titanium-based phthalocyanine, which is a fine primary particle having a particle size of 0.2 microns or less. The titanium-based phthalocyanine of the present invention is a phthalocyanine containing titanium metal and oxygen or chlorine as a core, and includes oxytitanium phthalocyanine (TiOPc), titanium phthalocyanine dichloride (TiCl ₂ Pc), or the benzene ring of the above phthalocyanine. Indicates that one or more of these are chlorinated. Phthalocyanine is generally produced by the phthalodinitrile method, which involves heating and melting phthalodinitrile and a metal chloride or by heating in the presence of an organic solvent, or by heating and melting phthalic anhydride with urea and a metal chloride or by heating in the presence of an organic solvent. Examples include, but are not limited to, the Weiler method, the method of reacting cyanobenzamide with a metal salt at high temperature, and the method of reacting dilithium phthalocyanine with a metal salt. Examples of organic solvents include α-chloronaphthalene, sulfolane, quinoline, and dichlorobenzene. The titanium-containing phthalocyanine used in the present invention is a "phthalocyanine compound" by Moser and Thomas.
Using known methods such as "Phthaloeyamine Compounds" and those obtained by the above-mentioned appropriate methods, compounds can be prepared from acids, alkalis, methanol, ethanol, acetone, methyl ethyl ketone, tetrahydrofuran, pyridine, quinoline, sulfolane, α- Chloronaphthalene, toluene, xylene, chloroform, carbon tetrachloride, dichloromethane, dichloroethane, trichloropropane, N,
It is obtained by washing with N'-dimethylformamide or the like, and can be further purified by sublimation. In the crystalline titanium-containing phthalocyanine compound synthesized by the above method, the particles are strongly aggregated and crystallized, and in the case of large particles of 1 to 2 microns.
Forms secondary particles larger than 10 microns. This agglomeration is extremely strong, and sand mills, ball mills,
Even if a crushing means such as an attritor or a roll mill is used, it is difficult to break down and become fine particles. In an electrophotographic photoreceptor containing the above-described coarse crystalline secondary particles in a charge generation layer, the number of carriers generated decreases due to a decrease in light absorption efficiency, resulting in a decrease in photosensitivity.
Furthermore, due to the non-uniformity of the charge generation layer, the injection efficiency of carriers into the charge transport layer decreases, resulting in electrostatic properties such as induction phenomenon, decrease in surface potential, and potential stability during repeated use. Unfavorable phenomena occur in terms of the sensitivity of the photoreceptor, such as poor performance. Furthermore, the image lacks uniformity and causes minute defects. The charge generation layer of the present invention using amorphous titanium-based phthalocyanine with a particle diameter of 0.2 microns or less, which is made of minute primary particles, is a uniform layer with high light absorption efficiency, and there are gaps between particles in the charge generation layer. An electrophotographic photoreceptor that satisfies many requirements, including characteristics as an electrophotographic photoreceptor such as potential stability and prevention of increase in bright area potential during repeated use, reduction of image defects, and printing durability. You can get a body. The oxytitanium phthalocyanine used as the charge generation layer has 2θ (±2°) = 9.2°, 13.1°, 20.7° using Cukα radiation with λ = 1.5418 (AU).
，
Those with X-ray diffraction peaks at 26.2° and 27.1° (θ is the Black angle) (Japanese Patent Application Laid-Open No. 59-49544), or
2θ=7.5°, 12.6°, 13.0°, 25.4°, 26.2° and 28
Those with an X-ray diffraction peak at .6° (JP-A-59-166959
(No.) is well known, but the materials synthesized and purified with solvents by each method are all in crystalline form. The titanium-based phthalocyanine of the present invention can be obtained by a single chemical method or mechanical method, but it is more preferable to use each method to create a material with weak cohesive force and then further loosen it into small pieces. Can be obtained by combination. For example, very fine primary particles can be obtained by weakening the aggregation between particles using a method such as an acid pasting method or an acid slurry method, and then grinding the particles using a mechanical processing method. Equipment used during grinding includes kneaders, Banbury mixers, attritors, edge runner mills,
Roll mill, ball mill, sand mill, SPEX mill, homo mixer, disperser, agitator,
Examples include, but are not limited to, a geo crusher, a stamp mill, a cutter mill, and a micronizer. In addition, the acid pasting method, which is well known as a chemical treatment method, is a method in which pigments are dissolved or made into sulfates in 95% or more sulfuric acid and then poured into water or ice water to re-precipitate. Keep the water preferably below 5℃,
By slowly injecting sulfuric acid into water that is stirred at high speed, it is possible to obtain fine particles under even better conditions. Other methods include a method in which crystalline particles are directly milled using a mechanical processing device for a very long time, a method in which particles obtained by an acid pasting method are treated with the above-mentioned solvent, etc., and then milled. It is also possible to obtain a small portion of amorphous primary particles immediately after dyeing. However, following the chemical treatment of crystalline particles, the microparticles obtained by mechanical treatment must be purified with the solvent used for washing the above-mentioned composite, and then chemically treated again, and It goes without saying that it is desirable to improve the degree of purification and to form fine particles by repeating appropriate treatments many times. The titanium-containing phthalocyanine compound obtained by the present invention is an amorphous particle whose diffraction angle cannot be read and does not have a clear interplanar spacing. Amorphous particles can also be obtained by sublimation. For example, titanium-based phthalocyanine, which is a raw material obtained by various methods, is heated to 500℃ under vacuum.
It can be obtained by heating it to 600°C to sublimate it and immediately depositing it on a substrate. The titanium-based phthalocyanine obtained by these methods is in an amorphous state and becomes fine particles depending on the precipitation conditions, but more preferably, separated fine particles are obtained by mechanical grinding. In addition, the absorption peak of the film obtained by sublimation through this treatment is around 750 nm, but after mechanical treatment, the absorption peak changes to 830 nm.
It has characteristics suitable for semiconductor lasers. The photoreceptor is preferably one in which an undercoat layer, a charge generation layer, and a charge transfer layer are laminated in this order on a conductive substrate. A charge generating agent and a charge transfer agent may be dispersed and coated with a suitable resin on the undercoat layer. By coating one or more of these titanium-based phthalocyanines as a charge generating agent with a suitable binder on a substrate, a charge generating layer having extremely good dispersibility and extremely high light absorption efficiency can be obtained. Although it is known that a charge generation layer can be obtained by vapor deposition, the material obtained by the present invention can be vapor-deposited extremely efficiently because it is made into fine particles and impurities existing between the particles are removed. It is also effective as a material. Coating can be done using a spin coater, applicator, spray coater, bar coater, dip coater,
Performed using a doctor blade, roller coater, curtain coater, bead coater equipment,
Drying is preferably carried out by heating at 40 to 200° C. for 10 minutes to 6 hours under stationary or blowing air conditions. After drying, the film is coated to a thickness of 0.01 to 5 microns, preferably 0.1 to 1 micron. Binders that can be used to form the charge generating layer by coating can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-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, polyvinylpyridine, cellulose resin, urethane Insulating resins such as resin, epoxy resin, silicone resin, polystyrene, polyketone, polyvinyl chloride, vinyl chloride-vinyl acid copolymer, polvinyl acetal, polyacrylonitrile, phenolic resin, melamine resin, casein, polyvinyl alcohol, polyvinylpyrrolidone, etc. can be mentioned. The resin contained in the charge generation layer is suitably 100% by weight or less, preferably 40% by weight or less. Further, these resins may be used alone or in combination of two or more. The solvent for dissolving these resins varies depending on the type of resin, and it is preferable to select a solvent that does not affect the charge generation layer and undercoat layer, which will be described later, during coating. Specifically, aromatic hydrocarbons such as benzene, xylene, ligroin, monochlorobenzene, dichlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, alcohols such as methanol, ethanol, isopropanol, ethyl acetate, methyl cellosolve, etc. esters of carbon tetrachloride, aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, and trichloroethylene, ethers such as tetrahydrofuran, dioxane, ethylene glycol mono, and methyl ether, N,N-
Amides such as dimethylformamide and N,N-dimethylacetamide, and sulfoxides such as dimethylsulfoxide are used. The charge transfer layer is formed by dissolving and dispersing a charge transfer agent alone or in a binder resin. Charge transfer substances include electron transfer substances and hole transfer substances, and electron transfer substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2.4.7-trinitro-9-fluorenone,
2.4.5.7-Tetranitro-9-fluorenone, 2.4.7
Examples include electron-withdrawing substances such as -trinitro-9-dicyanomethylenefluorenone, 2.4.5.7-tetranitroxanthone, and 2.4.8-trinitrothioxanthone, and polymerized versions of these electron-withdrawing substances. Examples of the hole transfer substance 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-
Hydrazones such as 1',1'-diphenylhydrazone, 1.3.3-trimethylindolenine-ω-aldehyde-N,N-diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone , 2.5-bis(P-diethylaminophenyl)-1.3.4-oxadiazole,
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-diethylaminophenyl)pyrazoline, 1-[pyridyl(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-diethylaminobenz Oxazole, 2-(P-diethylaminophenyl)-4-
Oxazole compounds such as (P-diethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-(P-diethylaminostyryl)-6-
Thiazole compounds such as diethylaminobenzotisol, triarylmethane compounds such as bis(4-diethylamino-2-methylphenyl)-phenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl)heptane,
1.1.2.2-Tetrakis(4-N,N-dimethylamino-2-methylphenyl)ethane and other polyarylalkanes, triphenylamine, poly-N-
Examples include vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, and ethylcarbazole formaldehyde resin. In addition to these organic charge transfer materials, inorganic materials such as selenium, selenium-tellurium amorphous silicon, and cadmium sulfide can also be used. In addition, these charge transfer substances may be one or two types.
More than one species can be used in combination. Resins used for the charge transfer layer include silicone resin, ketone resin, polymethyl methacrylate, polyvinyl chloride, acrylic resin polyarylate, polyester, polycarbonate, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, Insulating resins such as polysulfone, polyacrylamide, polyamide, chlorinated rubber, poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. are used. The coating method is performed using a spin coater, applicator, spray coater, bar coater, dip coater, doctor blade, roller coater, curtain coater, or bead coater, and the film thickness after drying is from 5 to 50 microns, preferably from 10 to 10. It is best to use a coating that has a thickness of 20 microns. In addition to these layers, an undercoat layer can be provided on the conductive substrate for the purpose of preventing deterioration of chargeability, improving adhesion, and the like. As an undercoat layer, alcohol-soluble polyamides such as nylon 6, nylon 66, nylon 11, nylon 610, copolymerized nylon, alkoxymethylated nylon, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, gelatin, polyurethane, polyvinyl Metal oxides such as butyral and aluminum oxide are used. It is also effective to incorporate conductive particles such as metal oxides and carbon black into the resin. The material of the present invention has an absorption peak at a wavelength of 800 mm or more, and is suitable not only for use as an electrophotographic photoreceptor in copying machines and printers, but also as an absorption material for solar cells, photoelectric conversion elements, and optical disks. Examples of the present invention will be described below. In the examples, parts refer to parts by weight. Example 1 20.4 parts o-phthalodinitrile, titanium tetrachloride
After heating and reacting 7.6 parts in 50 parts of α-chlornaphthalene at 200°C for 2 hours, the solvent was removed by steam distillation, and 2
% aqueous hydrochloric acid solution, followed by a 2% aqueous sodium hydroxide solution, washed with acetone, and dried to obtain 21.3 parts of oxytitanium phthalocyanine (TiOPc). Add 2 parts of this titanyl phthalocyanine to 98% at 5°C.
% sulfuric acid and the mixture is stirred for about 1 hour while maintaining the temperature below 5°C. Subsequently, the sulfuric acid solution was slowly poured into 400 parts of ice water that was stirred at high speed, and the precipitated crystals were filtered. The crystals were washed with distilled water until no acid remained, purified with acetone, and then dried to obtain 1.8 parts of oxytitanium phthalocyanine. next,
One part of this oxytitanium phthalocyanine was ground in a ball mill for 24 hours. The oxytitanium phthalocyanine thus obtained consists of fine primary particles of 0.2 microns or less, and does not have strong diffraction peaks as shown in the X-ray diffraction diagram of FIG. 0.3 parts of zinc oxide (SAZEX #2000 made by Sakai Chemicals) and 9.7 parts of polyvinyl alcohol (degree of saponification 86-89%) were mixed on a 75 micron thick sheet made of polyethylene terephthalate film with aluminum vapor deposition.
A coating solution prepared by dispersing 500 parts of ethanol in a ball mill for 3 hours was applied with a wire bar and dried by heating at 70°C for 3 hours to obtain a sheet having an undercoat layer with a thickness of 0.5 microns. Add 2 parts of titanyl phthalocyanine obtained by the above method to a solution of 1 part of phenoxy resin (PKHH manufactured by Union Carbide) in 97 parts of dioxane,
Dispersion was performed using a ball mill for 2 hours. This dispersion was applied onto the undercoat layer and dried at 100°C for 2 hours to form a charge generation layer of 0.3 microns. A solution prepared by dissolving 10 parts of 6-carboxaldehyde-1',1'-diphenylhydrazone and 10 parts of polyester resin (Vylon 200 manufactured by Toyobo Co., Ltd.) in 100 parts by weight of methylene chloride is applied onto the charge generation layer, dried, and formed into a 15-micron layer. A charge transfer layer was formed, an electrophotographic photoreceptor was obtained, and its characteristics were measured. FIG. 2 shows scanning electron micrographs of the oxytitanium phthalocyanine obtained in this example and the charge generation layer coated using the oxytitanium phthalocyanine. FIG. 2a shows the oxytitanium phthalocyanine itself, and FIG. 2b is a photograph of the surface of the charge generation layer. Moreover, the absorption spectrum is shown in FIG. 3 (solid line). Example 2 In place of the charge transfer agent of Example 1, 2-methyl-4-dibenzylaminobenzaldehyde-1'-
An electrophotographic photoreceptor was similarly prepared using ethyl-1'-phthalazinyl hydrazone, and its properties were measured. Example 3 In place of the charge transfer agent of Example 1, 2-methyl-4-dibenzylaminobenzaldehyde-1'-
An electrophotographic photoreceptor was similarly prepared using propyl-1'-benzothiazolylhydrazone, and its properties were measured. Example 4 20.4 parts o-phthalodinitrile, titanium tetrachloride
7.6 parts were heated in 50 parts of α-chlornaphthalene at 200°C for 2 hours. After the reaction, the solvent was removed by steam distillation, purified with a 2% aqueous hydrochloric acid solution, and dried to form titanium phthalocyanine dichloride (TiPcCl ₂ ).
Got 21.6 copies. This titanium phthalocyanine dichloride was subjected to acid pasting and ball mill dispersion in the same manner as in Example 1 to prepare an electrophotographic photoreceptor, and its properties were measured. Example 5 20.4 parts o-phthalodinitrile, titanium tetrachloride
7.6 parts were heated at 250° C. for 2 hours, and after reaction, purified with a 2% aqueous hydrochloric acid solution, followed by acetone, and dried to obtain 20.8 parts of monochlorotitanium phthalocyanine dichloride (ClTiPcCl ₂ ). This monochlorotitanium phthalocyanine dichloride was subjected to acid pasting and ball mill dispersion in the same manner as in Example 1 to prepare an electrophotographic photoreceptor, and its properties were measured. The absorption spectrum of monochlorotitanium phthalocyanine dichloride obtained in this example is shown in FIG. 3 (dotted line). Example 6 10 parts of oxytitanium phthalocyanine synthesized and purified by the method of Example 1 was sublimated by heating at 550° C. under a vacuum condition of 10 ⁻⁵ Torr, and deposited on a cooled substrate. This precipitate was taken out and ground in a ball mill for 50 hours to obtain 8.6 parts of titanyl phthalocyanine consisting of fine primary particles. Using this material, an electrophotographic photoreceptor was prepared in the same manner as in Example 1, and its characteristics were measured. Comparative Example 1 20.4 parts o-phthalodinitrile, titanium tetrachloride
7.6 parts were heated in 50 parts of α-chlornaphthalene at 200°C for 2 hours, and after the reaction, the solvent was removed by steam distillation, purified with a 2% aqueous hydrochloric acid solution, then a 2% aqueous sodium hydroxide solution, and then purified with acetone. After washing and drying, 21.3 parts of oxytitanium phthalocyanine was obtained. The oxytitanium phthalocyanine thus obtained consists of aggregated and crystalline particles of 1 micron or more, and exhibits a strong peak as shown in the X-ray diffraction diagram of FIG. Using this oxytitanium phthalocyanine, an electrophotographic photoreceptor was prepared in the same manner as in Example 1, and its characteristics were measured. FIG. 5 shows the oxytitanium phthalocyanine (a) obtained in this comparative example and the charge generation layer (b) coated using the oxytitanium phthalocyanine. The electrophotographic photoreceptor thus prepared was tested using an electrostatic copying paper tester SP-428 manufactured by Kawaguchi Electric.
Corona charged at 5.4KV, surface charge (Vo) and 5
White light half-reduction exposure sensitivity (E1/2) is calculated from the time when the chargeability decreases to 1/2 after irradiation with white light (W) of ux.
I looked into it. Also, the evaluation of repetition characteristics is −
Charging at 5.4KV, corona linear velocity 20m/min,
The sample was left in the dark for 2 seconds and then exposed to light at 5ux for 3 seconds, and the surface potential, residual potential, and deterioration of sensitivity were measured. The results are shown in Table 1. Note that the residual potential (VR ₃ ) is the potential 3 seconds after light irradiation. Furthermore, the photoreceptors prepared in this example and comparative example were attached to the drum of an electrophotographic copying machine having a corona charger, an exposure section, a development section, a transfer charging section, a static elimination exposure section, and a cleaner. The bright area potential of this copying machine was set to -650V and the dark area potential to -150V, and after a repeated durability test of 5000 sheets, the images were compared.

[Table] As a result of a durability test of 5,000 sheets, Examples 1 to 6, in which the charge generation layer was created using minute primary particles, had a durability test of 5,000 sheets.
While a beautiful image can be obtained even after the durability test, in Comparative Example 1, there are many white spots on the image, and as the durability test is repeated, the white spots become more numerous and larger. I couldn't get it. "Effects of the Invention" By developing and using a titanium-containing phthalocyanine compound consisting of non-agglomerated primary particles of 0.2 microns or less, the present invention achieves an extremely Obtain a uniform charge generation layer, thereby increasing the sensitivity and
It has become possible to create an electrophotographic photoreceptor that has improved repeat stability and provides extremely beautiful images. It also has high sensitivity in the long wavelength region of 750 mm or more, making it ideal as a photoreceptor for laser printers that use semiconductor lasers as light sources.

[Brief explanation of the drawing]

Figure 1 is an X-ray diffraction diagram of the oxytitanium phthalocyanine of Example 1 of the present invention, Figure 2 a is the particle structure of the oxytitanium phthalocyanine of Example 1, and b is a scanning electron microscope of the particle structure on the surface of the charge generation layer. The photographs, FIG. 3, are the absorption spectra of the oxytitanium phthalocyanines of Examples 1 and 5. FIG. 4 is the X-ray diffraction diagram of the crystalline oxytitanium phthalocyanine of Comparative Example 1.
Figure a shows the particle structure of the crystalline oxytitanium phthalocyanine of Comparative Example 1, and figure b shows a scanning electron micrograph of the particle structure on the surface of the charge generation layer.

[Claims]

An aqueous solution composition containing a water-soluble melamine resin, a curing catalyst for the water-soluble melamine resin, polyvinyl alcohol, a metal compound that is coordinated to the polyvinyl alcohol to produce a chelate compound, and a water-insoluble inorganic powder. After being applied to a base material, it is dried to form an intermediate layer, and then a liquid adhesive in which a photoconductive substance is dispersed is applied to the intermediate layer, and then dried to form a surface layer. A method for manufacturing lithographic printing plate material.