JPH0598181A - New crystal of chlorogallium phthalocyanine, photoconductive material composed of the same new crystal and electrophotographic photoreceptor using the same - Google Patents

Abstract

PURPOSE:To obtain the subject new crystal capable of providing electrophotographic photoreceptors, excellent in sensitivity characteristics or charge holding properties without impairing dispersibility of the crystal or coating properties of a dispersion due to its high sensitivity and durability as a photoconductive material. CONSTITUTION:The objective crystal having strong diffraction peaks at Bragg angles (2theta+ or -0.2 deg.) of at least 7.4 deg., 16.6 deg., 25.5 deg. and 28.3 deg. or 6.8 deg., 17.3 deg., 23.6 deg. and 26.9 deg. or 8.7-9.2 deg., 17.6 deg., 24' deg., 27.4k and 28.8 deg. in an X-ray diffraction spectrum. This crystal is obtained by synthesizing the crystal of chlorogallium phthalocyanine according to a phthalonitrile method for melting phthalonitrile with a metallic chloride by heating, a method for reacting dilithium phthalocyanine with a metallic salt, etc., and then subjecting the resultant crystal to successive dry and wet grinding treatments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel crystal of chlorogallium phthalocyanine, a photoconductive material comprising the novel crystal, and an electrophotographic photoreceptor using the same. The present invention relates to a combination of a constituent charge generating material and a binder resin.

[0002]

2. Description of the Related Art Hitherto, various materials have been proposed as a photosensitive material in an electrophotographic photosensitive member, and a laminated type electrophotographic photosensitive member in which a photosensitive layer is separated into a charge generating layer and a charge transporting layer. Also, various organic compounds have been proposed as charge generation materials. In recent years, there has been an increasing demand for extending the photosensitive wavelength range of conventionally proposed organic photoconductive materials to the wavelength (780 to 830 nm) of near-infrared semiconductor lasers and using it as a photoreceptor for digital recording such as laser printers. From this viewpoint, the squarylium compound (JP-A-49-105536 and JP-A-58-21416) is used.
JP-A No. 61-151659), phthalocyanine compounds (JP-A Nos. 48-34189 and 57-14874).
No. 5) has been proposed as a photoconductive material for semiconductor lasers.

When an organic photoconductive material is used as a photosensitive material for a semiconductor laser, first, the photosensitive wavelength region is extended to a long wavelength, and then the sensitivity and durability of the formed photoreceptor are good. Things are required. However, the above organic photoconductive material does not fully satisfy these conditions. In order to overcome these drawbacks, phthalocyanine compounds among the above organic photoconductive materials have been extensively studied in recent years as materials for electrophotographic photoreceptors, materials for optical recording and photoelectric conversion materials, and particularly crystalline type materials. And the relationship between electrophotographic characteristics are being investigated.

It is known that phthalocyanine compounds generally show several crystal types depending on the production method and the treatment method, and the difference in the crystal types has a great influence on the photoelectric conversion characteristics of the phthalocyanine compound. Regarding the crystal form of the phthalocyanine compound, for example, when looking at copper phthalocyanine, α, ε,
Crystal forms such as π, x, ρ, γ, and δ are known, and these crystal forms can be mutually transferred by mechanical strain, sulfuric acid treatment, organic solvent treatment, heat treatment, and the like. It is known (for example, US Pat. Nos. 2,770,629, 3,160,635, 3,708,292 and 3,357,989). In addition, JP-A-50-
In Japanese Patent No. 38543, regarding the relationship between the difference in crystal type of copper phthalocyanine and the electrophotographic characteristics, it is described that the ε type has the highest sensitivity in comparison of α, β, γ and ε types.

Furthermore, regarding chlorogallium phthalocyanine, the journal of the Electrophotographic Society, 26 (3), 240,
(1987) describes a crystal form of chlorogallium phthalocyanine having a diffraction peak at a specific Bragg angle. However, the crystal form of the present invention is different from that of the present invention, and a description of application to electrophotography. Nor. On the other hand, Japanese Patent Laid-Open No. 59-44053, Reitech Giho CPM8
1-69, 39 (1981) and the like, there is a description of application to electrophotography, and JP-A-1-221459.
The publication describes chlorogallium phthalocyanine having a diffraction peak at a specific Bragg angle and an electrophotographic photosensitive member using the same.

[0006]

However, not only the above-mentioned chlorogallium phthalocyanine but also the conventionally proposed phthalocyanine compounds are still satisfactory in terms of photosensitivity and durability when used as a photosensitive material. Moreover, in the production thereof, there are problems that the crystal type conversion operation is complicated, and that the crystal type is difficult to control. In addition, chlorogallium phthalocyanine is
When used as a photoreceptor, there is a problem in sensitivity characteristics and charge retention when dispersed in a binder resin, and the coatability of the dispersion is poor. A defect was generated, and it did not have sufficiently satisfactory characteristics.

The present invention has been made in view of the above-mentioned problems in the prior art. That is, an object of the present invention is to provide a novel crystal of chlorogallium phthalocyanine. Further, another object of the present invention is to
To provide a photoconductive material composed of a novel chlorogallium phthalocyanine crystal having excellent sensitivity characteristics and durability, and an electrophotographic photoreceptor having higher sensitivity characteristics, good charge retention, and few image quality defects. is there.

[0008]

As a result of intensive studies, the inventors of the present invention have a high sensitivity and durability as a photoconductive material by subjecting chlorogallium phthalocyanine obtained by synthesis to a simple treatment. It has been found that a new crystal can be obtained, and further, an electrophotographic photoreceptor containing the novel crystal and a specific binder resin in the photosensitive layer, impairs the crystal dispersibility and the coating property of the dispersion at the time of its production. Without
The inventors have found that they have more excellent sensitivity characteristics, good charge retention characteristics, and few image quality defects, and have completed the present invention. That is, according to the present invention, in the X-ray diffraction spectrum, the Bragg angle (2θ ± 0.2 °) is at least i).
7.4 °, 16.6 °, 25.5 ° and 28.3 °, i
i) 6.8 °, 17.3 °, 23.6 ° and 26.9 °
Or iii) 8.7 ° to 9.2 °, 17.6 °, 24.
It is a novel crystal of chlorogallium phthalocyanine having strong diffraction peaks at 0 °, 27.4 ° and 28.8 °. The present invention also resides in a photoconductive material for an electrophotographic photoreceptor, which comprises at least one kind of chlorogallium phthalocyanine crystal having the above diffraction peak. The present invention further resides in an electrophotographic photosensitive member comprising a conductive support and a photosensitive layer containing at least one kind of the chlorogallium phthalocyanine crystal described above, wherein the photosensitive layer is a chlorogallium phthalocyanine crystal and a polyvinyl acetal resin. , A vinyl chloride-vinyl acetate-based copolymer, a phenoxy resin and a modified ether type polyester resin having a laminated structure in which a charge generation layer containing at least one binder resin and a charge transport layer are sequentially laminated. preferable.

The present invention will be described in detail below. The novel crystal of the chlorogallium phthalocyanine of the present invention, which is useful as a photoconductive material, has a Bragg angle (2θ ± 0.2 °) of at least i) 7.4 °, 1 in the X-ray diffraction spectrum.
6.6 °, 25.5 ° and 28.3 °, ii) 6.8 °,
17.3 °, 23.6 ° and 26.9 ° or iii)
8.7 ° to 9.2 °, 17.6 °, 24.0 °, 27.
It has strong diffraction peaks at 4 ° and 28.8 ° and is manufactured as follows. That is, the phthalonitrile method in which phthalonitrile and a metal chloride are heated and melted or heated in the presence of an organic solvent, the phthalic anhydride is heated and melted with urea and a metal chloride, or a Weiler method in which it is heated in the presence of an organic solvent, cyano. It can be produced by a known phthalocyanine synthesis method such as a method of reacting benzamide with a metal salt at a high temperature, a method of reacting dilithium phthalocyanine with a metal salt, or the like.

Organic solvents used in these synthetic methods include α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dichlorobenzene. A reaction-inert, high-boiling-point solvent such as toluene is desirable. That is, the chlorogallium phthalocyanine of the present invention can be synthesized, for example, by heating and stirring a phthalonitrile and a gallium chloride compound in the above organic solvent at 150 to 300 ° C. Further, an indoline compound such as diiminoisoindoline can be used instead of phthalonitrile.

The crystals of chlorogallium phthalocyanine produced by the above method often have a large particle size, and in order to obtain the chlorogallium phthalocyanine crystals having the above X-ray diffraction peak of the present invention, it is necessary to make them finer. It is necessary to. The micronization is selected from a mechanical treatment method such as a grinding method and a chemical treatment method such as an acid pasting method and an acid slurry method, and two or more kinds of these treatment methods can be combined. The relatively large particle size produced by the method is dry-ground by a mechanical treatment method such as an automatic mortar, a planetary mill, a vibrating ball mill, a CF mill, a roller mill, a sand mill, and a kneader, or further after the dry-grinding. Wet milling in a solvent with milling media is preferred. During dry grinding, if necessary, a grinding aid such as sodium chloride and sodium sulfate is used, so that the crystal form of the present invention having a uniform particle size can be transferred very efficiently. The grinding aid is 0. 0 for chlorogallium phthalocyanine crystals.
It is used 5 to 20 times, preferably 1 to 10 times. And
The chlorogallium phthalocyanine crystal after dry grinding preferably has a primary particle size of 0.3 μm or less.

When dry grinding is used in combination with wet grinding, chlorogallium phthalocyanine having good crystallinity and a uniform particle size can be obtained. The solvent used in this wet milling treatment is, for example, an aromatic solvent such as toluene or chlorobenzene, or dimethylformamide (DM).
F), amide solvents such as N-methylpyrrolidone, aliphatic alcohol solvents such as methanol, ethanol and n-butanol, aliphatic polyhydric alcohol solvents such as glycerin and polyethylene glycol, cyclohexanone and methyl ethyl ketone (MEK) The solvent can be selected from the group consisting of a ketone solvent, an aliphatic halogenated hydrocarbon solvent such as methylene chloride, an ether solvent such as tetrahydrofuran (THF), water and the like in the form of one kind or a mixed solvent of two or more kinds. Further, as the grinding device, a ball mill, an attritor, a roll mill, a sand mill, a homomixer or the like can be used, but the grinding device is not limited to these. The amount of the solvent used is 1 to 200 parts, preferably 10 to 100 parts, relative to 1 part of chlorogallium phthalocyanine. The processing time of wet grinding is preferably 4 hours or longer, and the processing temperature is 0 ° C to the boiling point of the solvent or less, preferably 10 ° C.
Processed at ~ 60 ° C. Such solvent treatment may be carried out while milling with a grinding medium such as glass beads, steel beads, alumina beads or the like, if necessary.

Next, an electrophotographic photoreceptor prepared by using the chlorogallium phthalocyanine crystal obtained by the above-mentioned processing method as a photoconductive material in the photosensitive layer will be described. The electrophotographic photosensitive member of the present invention may have a single-layered photosensitive layer or a laminated structure in which a charge generation layer and a charge transport layer are functionally separated. When the photosensitive layer has a laminated structure, the charge generation layer is composed of the chlorogallium phthalocyanine crystal and the binder resin. 1 to 4 are sectional views schematically showing the electrophotographic photosensitive member of the present invention. In FIG. 1, a photosensitive layer comprising a charge generation layer 1 and a charge transport layer 2 laminated thereon is a conductive support 3
Is coated on top. In FIG. 2, an undercoat layer 4 is interposed between the charge generation layer 1 and the conductive support 3, and
In FIG. 3, the surface of the photosensitive layer is covered with the protective layer 5. Further, in FIG. 4, both the undercoat layer 4 and the protective layer 5 are laminated. The layers 1 to 5 will be described in detail below with the description of the photosensitive layer having a single-layer structure in the middle.

For the charge generation layer 1 in the electrophotographic photosensitive member of the present invention, a coating solution is prepared by dispersing the chlorogallium phthalocyanine crystal in a solution in which a binder resin is dissolved in an organic solvent to prepare a coating solution. It is formed by applying on top. The binder resin used can be selected from a wide range of resins. As a preferable binder resin, for example,
Polyvinyl butyral resin, polyvinyl formal resin, polyvinyl acetal resin such as partially acetalized polyvinyl butyral resin obtained by partially modifying butyral with formal or acetoacetal, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.) , Polycarbonate resin, polyester resin, modified ether type polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin,
Polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride-vinyl acetate Polymer, hydroxyl-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-
Vinyl chloride-vinyl acetate copolymers such as vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, styrene-butadiene copolymers, vinylidene chloride-
Insulating resins such as acrylonitrile copolymer, styrene-alkyd resin, silicon-alkyd resin, and phenol-formaldehyde resin can be used. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. However, it is not limited to these insulating resins or organic photoconductive polymers. These binder resins may be used alone or in combination of two or more.

The solvent that dissolves the binder resin is preferably selected from those that do not dissolve the undercoat layer 4. Specific organic solvents include alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol and benzyl alcohol, acetone, MEK,
Ketones such as cyclohexanone, amides such as DMF and dimethylacetamide, sulfoxides such as dimethylsulfoxide, THF, dioxane, diethyl ether,
Cyclic or linear ethers such as methyl cellosolve and ethyl cellosolve, methyl acetate, ethyl acetate, acetic acid n-
Esters such as butyl, methylene chloride, chloroform,
Aliphatic halogenated hydrocarbons such as carbon tetrachloride, dichloroethylene and trichlorethylene, mineral oil such as ligroin,
Aromatic hydrocarbons such as benzene, toluene, xylene,
Aromatic halogenated hydrocarbons such as chlorobenzene and dichlorobenzene can be used alone or in combination of two or more.

The mixing ratio (weight) of the chlorogallium phthalocyanine crystal and the binder resin is 40: 1 to 1:20,
It is preferably in the range of 10: 1 to 1:10. If the proportion of chlorogallium phthalocyanine crystals is too high, the stability of the coating solution will be reduced, while if it is too low, the sensitivity of the photoreceptor will be reduced, so it is preferable to set the above range. As a method for dispersing the chlorogallium phthalocyanine crystal, a ball mill dispersion method, an attritor dispersion method,
A usual method such as a sand mill dispersion method can be used. At this time, the particles are 0.5 μm or less, preferably 0.3 μm.
It is effective to reduce the particle size to less than or equal to μm, and more preferably to less than or equal to 0.15 μm. Further, it is necessary that the dispersion does not change the crystal form of chlorogallium phthalocyanine, but it is confirmed that the crystal form does not change from that before the dispersion even if any of the above dispersion methods carried out in the present invention is adopted. Has been done.

The coating liquid is applied by a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a Meyer bar coating method, a blade coating method, a roller coating method, an air knife coating method, a curtain coating method or the like. Can be adopted. The coating liquid is preferably dried by touching at room temperature and then by heat-drying at a temperature of 30 to 200 ° C. for 5 minutes to 2 hours while still or under blowing air. The thickness of the charge generation layer 1 is usually 0.05 to 5 μm, preferably 0.2 to 2.0 μm.

In the present invention, among the above-mentioned binder resins, the dispersibility in dispersing chlorogallium phthalocyanine crystals in the binder resin, the coatability of the dispersion liquid, the sensitivity characteristics of the photoconductor, the charge retention characteristics, and the image quality characteristics. From the viewpoint of, for example, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer,
It is preferable to select from at least one selected from phenoxy resins and modified ether type polyester resins. Furthermore, the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum is at least 7.4 ° and 16.6.
When the chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 25.5 ° and 28.3 ° and the above-mentioned binder resin are combined, the photographic characteristics of the electrophotographic photoreceptor are particularly excellent.

The charge transport layer 2 in the electrophotographic photosensitive member of the present invention is formed by containing a charge transport material in a suitable binder resin. As the charge transport material, 2,5-bis-
Oxadiazole derivatives such as (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-
Triphenylpyrazoline, 1- [pyridyl- (2)]-
Pyrazoline derivatives such as 3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, aromatic tertiary monoamino compounds such as triphenylamine and dibenzylaniline, N, N'-diphenyl-
Aromatic tertiary diamino compounds such as N, N'-bis- (m-tolyl) benzidine, 3- (p-diethylaminophenyl) -5,6-di- (p-methoxyphenyl) -1,
1,2-Triazine derivatives such as 2,4-triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde 2,2-diphenylhydrazone, 2-phenyl-
Quinazoline derivatives such as 4-styrylquinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di- (p-methoxyphenyl) benzofuran, p- (2,2-diphenylvinyl) -N, N-diphenylaniline and the like. α-
Stilbene derivative, triphenylmethane derivative, Jou
rnal of ImagingScience, 2
9, 7-10 (1985), enamine derivatives, carbazole, N-ethylcarbazole, poly-
N-vinylcarbazole, halogenated poly-N-vinylcarbazole, polyglycidylcarbazole, poly-γ
-Carbazole ethyl glutamate and its derivatives, and further polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, nitrogen-containing heterocyclic compounds such as indole and imidazole, polyvinylanthracene, poly-9-vinylphenylanthracene, polyvinylpyrene, polyvinyl Acridine, polyvinyl acenaphthylene, pyrene-
Well-known charge transport materials such as formaldehyde resin and ethylcarbazole-formaldehyde resin can be used, but not limited thereto. These charge transport materials may be used alone or in combination of two or more, and when the charge transport material is a polymer, it may form a layer by itself.

The binder resin forming the charge transport layer 2 includes polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, and styrene-butadiene copolymer. Polymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin The same resin as that used for the charge generation layer 1 such as a poly-N-vinylcarbazole resin can be used. The charge transport layer 2 is prepared by preparing a coating solution using the above charge transport material, a binder resin, and the same organic solvent as that used in forming the charge generating layer 1, and then applying the same means as the coating method described above. Thus, the coating liquid can be applied onto the charge generation layer 1 to form the same. At that time, the compounding ratio (weight) of the charge transport material and the binder resin is preferably 10: 1 to 1: 5. The thickness of the charge transport layer 2 is generally 5 to
About 50 μm, preferably 10 to 30 μm is suitable.

When the photosensitive layer of the present invention has a single layer structure, the photosensitive layer comprises a photoconductive layer in which a chlorogallium phthalocyanine crystal and a charge transport material are dispersed in a binder resin. As the charge transport material and the binder resin, the same materials as described above are used, and the photoconductive layer is formed by the same method as described above. In that case, the binder resin is most preferably selected from at least one selected from polyvinyl acetal resins, vinyl chloride-vinyl acetate copolymers, phenoxy resins and modified ether type polyester resins for the same reason as above. preferable. The compounding ratio (weight) of the charge transport material and the binder resin is 1:20 to 5: 1, and the compounding ratio (weight) of the chlorogallium phthalocyanine crystal and the charge transport material is about 1:10 to 10: 1. It is preferable to set.

As the conductive support 3, any support can be used as long as it can be used as an electrophotographic photoreceptor. Specifically, aluminum,
Metals such as nickel, chrome, stainless steel, aluminum, titanium, nickel, chrome, stainless steel,
Examples thereof include a plastic film coated with a thin film of gold, vanadium, tin oxide, indium oxide, ITO or the like, paper coated with or impregnated with a conductivity-imparting agent, and a plastic film. These conductive supports 3 are
It may be used in any suitable shape such as a drum shape, a sheet shape, or a plate shape, but is not limited thereto. Further, if necessary, the surface of the conductive support 3 may be subjected to various treatments within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment and coloring treatment, or irregular reflection treatment such as graining. Etc. may be given.

In the present invention, an undercoat layer 4 may be further interposed between the conductive support 3 and the photosensitive layer. The undercoat layer 4 prevents injection of charges from the conductive support 3 into the photosensitive layer during charging of the photosensitive layer having a laminated structure, and also integrally holds the photosensitive layer to the conductive support 3 by holding. It exhibits an action as an adhesive layer to be applied, or in some cases, an action to prevent reflection of light of the conductive support 3 and the like. Undercoat layer 4
As a material for forming, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, Vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyacrylic acid resin, polyacrylamide resin, polyvinylpyrrolidone resin, polyvinylpyridine resin, water-soluble polyester resin, cellulose ester resin such as nitrocellulose, cellulose ether resin, casein, gelatin , Polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate compounds, zirconium alkoxide compounds and other organic zirconium compounds, chi Nirukireto compounds, organic titanyl compounds such as titanyl alkoxide compound, it may be a known binder resin such as a silane coupling agent. The coating method adopted when forming the undercoat layer 4 is a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method,
Bead coating method, air knife coating method,
A usual method such as a curtain coating method can be used.
The thickness of the undercoat layer 4 is 0.01 to 10 μm, preferably 0.05 to 2 μm.

In the present invention, the surface of the photosensitive layer may be coated with a protective layer 5 if necessary. The protective layer 5 is coated to prevent chemical deterioration of the charge transport layer 2 during charging of the photosensitive layer having a laminated structure and to improve the mechanical strength of the photosensitive layer. The protective layer 5 is formed by containing a conductive material in a suitable binder resin. As the conductive material, a metallocene compound such as dimethylferrocene, N,
Aromatic amino compounds such as N'-diphenyl-N, N'-bis- (m-tolyl) benzidine, metal oxides such as antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide-antimony oxide, etc. are used. However, the present invention is not limited to these. As the binder resin used for the protective layer 5, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinylketone resin, polystyrene resin, polyacrylamide resin and the like are used. You can The protective layer 5 is preferably configured so that its electric resistance is 10 ⁹ to 10 ¹⁴ Ω · cm. When the electric resistance is higher than 10 ¹⁴ Ω · cm, the residual potential is increased and a copy with a large amount of fog is produced, while when it is lower than 10 ⁹ Ω · cm, the image is blurred and the resolution is lowered. Also, the protective layer should be constructed so as not to substantially interfere with the transmission of the light applied to the image exposure. As the coating method adopted when forming the protective layer 5, there are used ordinary methods such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method and a curtain coating method. Can be used. The thickness of this protective layer 5 is 0.5.
-20 μm, preferably 1-10 μm is suitable.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition, in an Example and a comparative example, "part" means a weight part. Synthesis Example (Synthesis of chlorogallium phthalocyanine) 1,3-diiminoisoindoline (30 parts) and gallium trichloride (9.1 parts) were added to quinoline (230 parts), and the temperature was adjusted to 200 ° C.
After reacting for 3 hours in, the product was filtered and washed with acetone, methanol. Next, the wet cake was dried to obtain 28 parts of chlorogallium phthalocyanine crystals. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 1 3.0 parts of the chlorogallium phthalocyanine crystal obtained in the synthesis example was placed in an automatic mortar (Yamato Scientific Co., Ltd .: Lab-Mi).
(11 UT-21 type) for 3 hours. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 2 0.5 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was ball milled with 60 parts of 1 mmφ glass beads in 20 parts of a mixed solvent of water / chlorobenzene 1:10 at room temperature for 24 hours. After that, it was filtered, washed with 10 parts of methanol, and dried to obtain a chlorogallium phthalocyanine crystal. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 3 0.5 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was ball-milled with 20 parts of methylene chloride at room temperature for 24 hours together with 60 parts of 1 mmφ glass beads, followed by filtration and ethanol. It was washed with 10 parts to obtain a chlorogallium phthalocyanine crystal. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 4 0.5 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was ball milled together with 60 parts of 1 mmφ glass beads in 20 parts of chlorobenzene for 24 hours at room temperature, then filtered and separated with methanol 10 It was washed with parts to obtain chlorogallium phthalocyanine crystals. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 5 0.5 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was ball-milled with 60 parts of 1 mmφ glass beads in 20 parts of methanol at room temperature for 24 hours, filtered and separated with methanol 10. It was washed with parts to obtain chlorogallium phthalocyanine crystals. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Examples 6 to 10 1 part of the chlorogallium phthalocyanine crystals obtained in each of Examples 1 to 5 was polyvinyl butyral (Sekisui Chemical Co., Ltd .: S-REC BM-S) 1 part and cyclohexanone 1
It was mixed with 00 parts and treated with a glass bead with a paint shaker for 1 hour to prepare a coating liquid in which the above crystals were dispersed. Then, using an aluminum substrate as the conductive support 3, the above coating solution is applied thereon by a dip coating method, and dried by heating at 100 ° C. for 5 minutes to give a film thickness of 0.2 μm.
m charge generation layer 1 was formed.

Next, the following structural formula (1)

[Chemical 1] N, N'-diphenyl-N, N'-bis-
2 parts of (m-tolyl) benzidine

The following structural formula (2)

[Chemical 2] And 3 parts of poly [1,1-di- (p-phenylene) cyclohexane carbonate] represented by
And the obtained coating liquid is applied onto the aluminum substrate having the charge generation layer 1 formed thereon by a dip coating method,
It was heated and dried at 120 ° C. for 1 hour to form a charge transport layer 2 having a film thickness of 20 μm.

The electrophotographic characteristics of the electrophotographic photosensitive member thus produced were measured as follows. Using an electrostatic copying paper tester (Kawaguchi Denki Co., Ltd .: Electrostatic Analyzer EPA-8100), the photoreceptor is charged by corona discharge of -6 KV in an environment of normal temperature and normal humidity (20 ° C, 50% RH). After that, the light of the tungsten lamp was dispersed into monochromatic light of 800 nm using a monochromator, adjusted to 1 μW / cm ² on the surface of the photoconductor, and irradiated. Then, the initial surface potential V ₀ (V), half decay exposure amount E _1/2 until 1/2 of V ₀ (e
rg / cm ² ) was measured, and then 10 lux of tungsten light was irradiated onto the surface of the photoconductor for 1 second to obtain a residual potential V
_R (volt) was measured. The attenuation rate DDR (%) was also measured. Furthermore, 100 times the above charging and exposure.
After repeating 0 times, V ₀ , E _1/2 , DDR and V _R were measured. The results are shown in Table 1 below together with Comparative Examples 1 and 2 below.

Comparative Example 1 An electrophotographic photoreceptor prepared by forming a charge generation layer 1 and a charge transport layer 2 by the same method as in Example 6 except that the chlorogallium phthalocyanine crystal obtained in the synthesis example was used. Was evaluated in the same manner as in Example 6.

Comparative Example 2 0.5 part of the chlorogallium phthalocyanine crystal obtained in Example 1 was ball milled in 20 parts of ethylene glycol at room temperature for 20 hours together with 60 parts of 1 mmφ glass beads, and then the glass beads were removed. It is separated by filtration and methanol 1
It was washed with 0 part to obtain a chlorogallium phthalocyanine crystal. FIG. 11 shows a powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal. Then, the charge generation layer 1 and the charge transport layer 2 were formed in the same manner as in Example 6, and the produced electrophotographic photosensitive member was evaluated in the same manner as in Example 6.

[0037]

[Table 1]

Example 11 An alcohol-soluble nylon resin (manufactured by Dainippon Ink and Chemicals, Inc .: Lackamide L-5003) on an aluminum substrate.
A solution consisting of 1 part and 10 parts of methanol is applied by a dip coating method, and dried by heating at 120 ° C. for 10 minutes,
An undercoat layer 4 having a film thickness of 0.5 μm was formed. Next, 1 part of the chlorogallium phthalocyanine crystal obtained in Example 2 was mixed with 1 part of polyvinyl butyral resin (Sekisui Chemical Co., Ltd .: S-REC BM-S) and 100 parts of n-butyl acetate, and the mixture was mixed with glass beads in a paint shaker. It was treated for 1 hour and dispersed in the resin solution. The obtained coating solution was applied onto the undercoat layer 4 by a dip coating method and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer 1 having a film thickness of 0.15 μm. It was confirmed by X-ray diffraction that the crystal form of the chlorogallium phthalocyanine crystal after dispersion was not changed as compared with the crystal form before dispersion.

Next, N, represented by the structural formula (1),
2 parts of N'-diphenyl-N, N'-bis- (m-tolyl) benzidine and poly [1,1] represented by the above structural formula (2).
1-di- (p-phenylene) cyclohexanecarbone
[3 parts] dissolved in 20 parts of chlorobenzene, and the obtained coating solution is applied on an aluminum substrate on which the charge generation layer 1 is formed by a dip coating method, and dried by heating at 120 ° C. for 1 hour to form a film thickness. A 20 μm charge transport layer 2 was formed.

The electrophotographic characteristics of the electrophotographic photosensitive member thus produced were measured as follows. Using an electrostatic copying paper tester (Kawaguchi Denki: Electrostatic Analyzer EPA-8100), room temperature and humidity (20
After charging the photoconductor by corona discharge of −6 KV in an environment of 40 ° C. and 40% RH, the light from the tungsten lamp is
A monochromatic light of 800 nm was dispersed using a monochromator, adjusted to 1 μW / cm ² on the surface of the photoreceptor, and irradiated. Then, the initial surface potential V _O (volt) and the half-exposure amount E _1/2 (erg / cm ² ) are measured,
Then, 10 lux of white light was irradiated onto the surface of the photoconductor for 1 second, and the residual potential V _R (volt) was measured. Further, V _O after repeating the above charging and exposure 1000 times,
E _1/2 and V _R were measured. The chlorogallium phthalocyanine crystal that constitutes the charge generation layer 1, the binder resin, and the above measurement results are shown in Table 2 below together with Examples 12 to 17 and Comparative Examples 3 to 6 below.

Example 12 Instead of the polyvinyl butyral resin constituting the charge generation layer 1, a polyester resin (manufactured by Toyobo Co., Ltd .: Byron 2) was used.
(00) A photoconductor similar to that of Example 11 was prepared except that 1 part was used, and the same measurement was performed.

Comparative Example 3 A photoconductor was prepared in the same manner as in Example 11 except that the chlorogallium phthalocyanine crystal obtained in Synthesis Example was used instead of the chlorogallium phthalocyanine crystal obtained in Example 2. The measurement was performed.

Comparative Example 4 A photoconductor was prepared in the same manner as in Example 11 except that the chlorogallium phthalocyanine crystal obtained in Comparative Example 2 was used in place of the chlorogallium phthalocyanine crystal obtained in Example 2. Was measured.

Example 13 The same procedure as in Example 2 was repeated except that THF was used instead of the water / chlorobenzene mixed solvent. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal was similar to that of FIG. 7.

Next, a solution consisting of 1 part of alcohol-soluble nylon resin (CM-8000 manufactured by Toray Industries, Inc.) and 10 parts of methanol was applied on an aluminum substrate by a dip coating method, and heated and dried at 110 ° C. for 10 minutes to form a film. An undercoat layer 4 having a thickness of 0.1 μm was formed. Then the above THF
Chlorogallium phthalocyanine crystal 1 obtained by treatment
Part was mixed with 1 part of partially acetoacetalized polyvinyl butyral resin (Sekisui Chemical Co., Ltd .: S-REC BX-L) and 100 parts of cyclohexanone, and treated with glass beads for 1 hour on a paint shaker to be dispersed in the resin solution. The obtained coating liquid was applied onto the undercoat layer 4 by a dip coating method, and dried by heating at 120 ° C. for 10 minutes to form a charge generation layer 1 having a thickness of 0.2 μm. It was confirmed by X-ray diffraction that the crystal form of the chlorogallium phthalocyanine crystal after dispersion was not changed as compared with the crystal form before dispersion.

Then, N represented by the structural formula (1),
Instead of N′-diphenyl-N, N′-bis- (m-tolyl) benzidine, the following structural formula (3)

[Chemical 3] N, N′-bis- (p-tolyl) -N, N ′ represented by
The same procedure as in Example 11 was repeated except that 2 parts of -bis- (p-ethylphenyl) -3,3'-dimethylbenzidine were used.
The same measurement as 1 was performed.

Example 14 Instead of the partially acetoacetalized polyvinyl butyral resin constituting the charge generation layer 1, a polymethylmethacrylate resin (DuPont: Elvasite 2021) 1 was used.
A photoreceptor was prepared in the same manner as in Example 13 except that the parts were used, and the same measurements were performed.

Comparative Example 5 A photoconductor was prepared in the same manner as in Example 13 except that the chlorogallium phthalocyanine crystal obtained in Comparative Example 2 was used instead of the chlorogallium phthalocyanine crystal obtained in Example 13. Was measured.

Example 15 A solution containing 10 parts of a zirconium compound (manufactured by Matsumoto Pharmaceutical Co., Ltd .: Organix ZC540) and 1 part of a silane compound (manufactured by Japan Junker Co .: A1110), 40 parts of i-propanol and 20 parts of butanol was placed on an aluminum substrate. Was applied by a dip coating method and heated and dried at 160 ° C. for 10 minutes to form an undercoat layer 4 having a film thickness of 0.1 μm.
Next, 1 part of the chlorogallium phthalocyanine crystal obtained by the THF treatment in Example 13 was combined with 1 part of a carboxyl-modified vinyl chloride-vinyl acetate copolymer (VMCH manufactured by Union Carbide Co.) and 100 parts of n-butyl acetate. Mix and 1 on a paint shaker with glass beads
It was treated for a time and dispersed in the copolymer solution. The obtained coating liquid is applied onto the undercoat layer 4 by a dip coating method,
0.2 µm film thickness after heating and drying at 100 ° C for 10 minutes
The charge generation layer 1 was formed. It was confirmed by X-ray diffraction that the crystal form of the chlorogallium phthalocyanine crystal after dispersion was not changed as compared with the crystal form before dispersion. Then, the same charge transport layer 2 as in Example 13 was formed, and the same measurement as in Example 13 was performed on the manufactured photoconductor.

Example 16 Example 16 was repeated except that 1 part of a phenoxy resin (PKHH manufactured by Union Carbide Co.) and 100 parts of cyclohexanone were used in place of the modified vinyl chloride-vinyl acetate copolymer constituting the charge generation layer 1. A photoconductor similar to that of 15 is prepared,
The same measurement was performed.

Example 17 A modified ether type polyester resin (manufactured by Fuji Photo Film Co., Ltd .: STAFIX NLC-2) was used instead of the modified vinyl chloride-vinyl acetate copolymer constituting the charge generation layer 1.
A photoconductor similar to that of Example 15 was prepared except that 1 part and 100 parts of cyclohexanone were used, and the same measurement was performed.

Comparative Example 6 A photoconductor was prepared in the same manner as in Example 15, except that the chlorogallium phthalocyanine crystal obtained in Comparative Example 2 was used instead of the chlorogallium phthalocyanine crystal obtained in Example 13. Was measured.

[0053]

[Table 2]

Examples 18 to 22 Drum type photoconductors were prepared under the same conditions as in Examples 11, 13 and 15 to 17, and the electrophotographic photoconductors were used as semiconductor laser printers (Fuji Xerox: FX XP-1).
It was mounted on 5) to form a copied image, and copying was repeated 10,000 times. The results are shown in Table 3 together with Comparative Examples 7 to 9 below.

Comparative Examples 7 to 9 Drum type photoconductors were prepared under the same conditions as in Comparative Examples 4 to 6,
The same evaluation as in Example 18 was performed.

[0056]

[Table 3]

[0057]

The chlorogallium phthalocyanine crystal of the present invention has a novel crystal type as described above, and since the photosensitive wavelength region extends to a long wavelength, it can be used in electronic devices such as printers utilizing semiconductor lasers. It is very useful as a photoconductive material for photographic photoreceptors. Further, the electrophotographic photoreceptor of the present invention produced by using the chlorogallium phthalocyanine crystal having the above-mentioned novel crystal form has high sensitivity, low residual potential, high chargeability, and little fluctuation due to repetition. Therefore, it can be used as a photoreceptor having excellent durability. Further, a chlorogallium phthalocyanine crystal as a charge generating material and at least one selected from a polyvinyl acetal resin, a vinyl chloride-vinyl acetate copolymer, a phenoxy resin and a modified ether type polyester resin as a binder resin are used as a photosensitive layer. The electrophotographic photosensitive member containing the electrophotographic photosensitive member has high sensitivity, good charge retention, and few image quality defects. Therefore, an electrophotographic photosensitive member having remarkably excellent image characteristics can be provided.

[Brief description of drawings]

FIG. 1 shows a schematic sectional view of an electrophotographic photosensitive member according to the present invention.

FIG. 2 shows another schematic cross-sectional view of the electrophotographic photosensitive member according to the present invention.

FIG. 3 shows another schematic cross-sectional view of the electrophotographic photosensitive member according to the present invention.

FIG. 4 shows still another schematic cross-sectional view of the electrophotographic photosensitive member according to the present invention.

FIG. 5 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in the synthesis example.

FIG. 6 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 1.

7 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 2. FIG.

8 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 3. FIG.

FIG. 9 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 4.

FIG. 10 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Example 5.

FIG. 11 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Comparative Example 2.

[Explanation of symbols]

1 ... Charge generation layer, 2 ... Charge transport layer, 3 ... Conductive support, 4 ... Undercoat layer, 5 ... Protective layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Imai 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Zero Tux Co., Ltd., Takematsu Plant (72) Inventor Yasushi Sakaguchi 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Zero Tux Co., Ltd. Takematsu Business (72) Inventor Toru Ishii 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Zero Tsukus Co., Ltd. Takematsu Office

Claims (7)

[Claims] 1. In an X-ray diffraction spectrum, the Bragg angle (2θ ± 0.2 °) is at least 7.4 °, 16.
6 °, 25.5 ° and 28.3 °, or 6.8 °, 1
7.3 °, 23.6 ° and 26.9 °, or 8.7 °
A chlorogallium phthalocyanine crystal having strong diffraction peaks at ˜9.2 °, 17.6 °, 24.0 °, 27.4 ° and 28.8 °. 2. A photoconductive material for an electrophotographic photosensitive member, comprising the chlorogallium phthalocyanine crystal according to claim 1. 3. An electrophotographic photoreceptor comprising a conductive support and a photosensitive layer containing the chlorogallium phthalocyanine crystal according to claim 1. 4. The photosensitive layer contains at least one selected from a polyvinyl acetal resin, a vinyl chloride-vinyl acetate copolymer, a phenoxy resin and a modified ether type polyester resin as a binder resin. The electrophotographic photoconductor according to item 1. 5. The electrophotographic photosensitive member according to claim 4, wherein the polyvinyl acetal resin is one or more selected from polyvinyl butyral resin, polyvinyl formal resin, and partially acetalized polyvinyl butyral resin. 6. The vinyl chloride-vinyl acetate copolymer is selected from vinyl chloride-vinyl acetate copolymer, hydroxyl-modified vinyl chloride-vinyl acetate copolymer and carboxyl-modified vinyl chloride-vinyl acetate copolymer. The electrophotographic photosensitive member according to claim 4, which comprises one kind or two or more kinds. 7. The photosensitive layer has a laminated structure in which a charge generation layer and a charge transport layer are sequentially laminated, and the chlorogallium phthalocyanine crystal and the binder resin are contained in the charge generation layer. The electrophotographic photosensitive member according to claim 4.