JPH09169924A - New crystal of zinc tetra-2,3-pyrazinoporphyrazine, photoconductive material comprising the crystal and electrophotographic photoreceptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new zinc tetra-2,3-pyrazinoporphyrazine crystal excellent in photosensitivity and durability as a photoconductive material, to provide a photoconductive material comprising the crystals, and to provide an electrophotogrpahic photoreceptor using the same. SOLUTION: This zinc tetra-2,3-pyrazinoporphyrazine crystal is selected from a crystal having a diffraction peak at a Bragg angle (θ±0.2 deg.) of at least 27.0 deg. in a X-ray diffraction spectrum based on CuKα rays, a crystal having main diffraction peaks at Bragg angles of at least 7.4 deg., 11.3 deg., 17.8 deg., 19.3 deg., 27.1 deg. and 28.6 deg., and a crystal having a main diffraction peak at a Bragg angle of at least 27.9 deg.. This photoconductive material comprises the crystals, and this electrophotographic photoreceptor uses the materials.

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 specific zinc tetra-2,3-pyrazinoporphyrazine having excellent charge generating ability, a photoconductive material comprising the crystal, and an electrophotographic photosensitive material using the same. It is about the body.

[0002]

2. Description of the Related Art Conventionally, various inorganic and organic photoconductive materials have been proposed as a photosensitive material for an electrophotographic photosensitive member, and a laminated type in which a charge generating layer and a charge transporting layer are functionally separated from each other. A large number of organic compounds are known as charge generating materials used in an electrophotographic photosensitive member including a photosensitive layer and an electrophotographic photosensitive member including a single-layer type photosensitive layer having a charge generating ability and a charge transporting ability in a single layer. There is. In recent years, there has been an increasing demand for using electrophotographic photoreceptors for digital recording in laser printers and the like, and from this viewpoint, a squarerium compound (Japanese Patent Laid-Open Nos. 49-105536 and 58-21416). ), Triphenylamine-based trisazo compounds (JP-A-61-151659), phthalocyanine compounds (JP-A-48-34189),
JP-A-57-148745) has been proposed as a photoconductive material for semiconductor lasers.

When an organic photoconductive material is used as a photoconductive material for a semiconductor laser, the photosensitive wavelength must first be extended to a long wavelength, and then the photoconductor to be formed must have high photosensitivity and durability. Good things are required. However, many of the above-mentioned organic photoconductive materials do not always have sufficient electron transporting ability as a photoconductive material, and problems such as increase in residual potential and accompanying decrease in photosensitivity occur during repeated use. It does not fully satisfy the conditions. In order to overcome these drawbacks, among the above organic photoconductive materials, phthalocyanine compounds have been extensively studied in recent years as materials for electrophotographic photoreceptors, materials for optical recording and photoconductive conversion materials. The relationship between crystal type and electrophotographic properties has been investigated.

It is generally known that a phthalocyanine compound is divided into several crystal types due to the difference in its production method or treatment method, and that different crystal types have a great influence on the photoelectric conversion characteristics of the phthalocyanine compound. There is. Regarding the crystal form of the phthalocyanine compound,
For example, regarding copper phthalocyanine, stable β
In addition to the types, crystal types such as α, ε, π, χ, ρ, γ, and δ are known, and these crystal types are mutually affected by mechanical strain, sulfuric acid treatment, organic solvent treatment, heat treatment, etc. Is known to be capable of metastasis (for example, US Pat. Nos. 2,770,629 and 3,160,635).
No. 3,708,292 and No. 3,708,292
357,989). In addition, JP-A-50-385
Japanese Patent Laid-Open No. 43-43 describes that the ε-type has the highest sensitivity in comparison between α-type, β-, γ-type and ε-type in relation to the difference in crystal type of copper phthalocyanine and electrophotographic characteristics.

Regarding the tetraazaporphyrin derivative known as a phthalocyanine-like compound, in JP-A-2-29660, JP-A-2-33156 and JP-A-2-35436, a photoconductive material having a low residual potential is disclosed. It is described that it can be applied to electrophotography as a material. As described above, the phthalocyanine-based compound and its analogs have been extensively studied for their use as photoconductive materials.

[0006]

However, the conventional photoconductors using phthalocyanine and its similar compounds have the following problems.
Usually, the residual potential is high, and it was not always satisfactory in terms of potential stability and sensitivity upon repeated use. The present invention has been made to solve the above problems in the conventional art. That is, an object of the present invention is to provide a novel zinc tetra-2,3-pyrazinoporphyrazine crystal having excellent photosensitivity and durability as a photoconductive material, and a layered structure of either a laminated type or a single layered type. Also in the above, it is to provide a photoconductive material for an electrophotographic photosensitive member that can be put to practical use and an electrophotographic photosensitive member using the same.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventor has obtained zinc tetra-2,3 obtained by synthesis.
-By subjecting pyrazinoporphyrazine to a simple treatment, not only hole transport but also electron transport at the time of photoconductivity are excellent, and it has high photosensitivity as a photoconductive material for an electrophotographic photoreceptor and has repeated stability. It was found that excellent new crystals can be obtained, and the present invention has been completed.

That is, the zinc tetra-2,3- of the present invention
The pyrazinoporphyrazine crystal is a crystal having a diffraction peak at a Bragg angle (2θ ± 0.2 °) of at least 27.0 ° as measured by a powder X-ray diffractometer using CuKα ray as an X-ray source. .4 °, 11.3 °, 17.8
Crystals having major diffraction peaks at °, 19.3 °, 27.1 ° and 28.6 °, or at least 27.9
It is characterized by being a crystal selected from crystals having a main diffraction peak at °.

The photoconductive material for an electrophotographic photoreceptor of the present invention comprises:
It is characterized by comprising the above-mentioned zinc tetra-2,3-pyrazinoporphyrazine crystal. Further, the electrophotographic photoreceptor of the present invention has the above-mentioned zinc tetra-
It is characterized in that a photosensitive layer containing at least one kind of 2,3-pyrazinoporphyrazine crystals is coated.

[0010]

Embodiments of the present invention will be described below in detail. Zinc tetra-used in the present invention
2,3-Pyrazinoporphyrazine can be produced by a generally known method for synthesizing porphyrazine compounds (for example, Kogaku Kogaku, Vol. 61, p. 994 (1958)). That is, a method of heating and melting 2,3-dicyanopyrazine and a metal chloride or a metal acetate, or heating in the presence of an organic solvent to obtain an anhydride thereof from pyrazino-2,3-dicarboxylic acid, It can be produced by a method such as heating and melting urea and metal chloride or heating in the presence of an organic solvent, a method of reacting pyrazino-2,3-benzamide and a metal salt at high temperature, and the like. As the organic solvent used in the above synthesis method, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dichlorotoluene, dimethyl. A reaction-inert, high-boiling-point solvent such as formamide, dimethyl sulfoxide, or dimethyl sulfamide is preferable.

The raw material used in the present invention is zinc tetra-
2,3-pyrazinoporphyrazine is, for example, 2,3-pyrazinoporphyrazine.
It can be produced by heating and stirring dicyanopyrazine and anhydrous zinc acetate in the temperature range of 170 to 250 ° C. in the above organic solvent. The novel zinc tetra-2,3-pyrazinoporphyrazine crystal, which is the object of the present invention, has (a) a Bragg angle (2θ) in the above powder X-ray diffraction.
Crystal having a diffraction peak at least 27.0 °, (b) Bragg angle (2θ ± 0.2 °),
At least 7.4 °, 11.3 °, 17.8 °, 19.
Crystals having major diffraction peaks at 3 °, 27.1 ° and 28.6 °, or (c) Bragg angle (2θ ± 0.
2 °) is selected from three types of crystals having a main diffraction peak at least at 27.9 °.

The novel zinc tetra-2,3-pyrazinoporphyrazine crystals represented by the above (a) to (c) of the present invention are zinc tetra-2,3-pyrazinoporphyrazine obtained by the above method. Can be obtained by applying a simple treatment to. First, since the zinc tetra-2,3-pyrazinoporphyrazine produced by the above method often has a large particle size, it is pulverized to make it finer if necessary. The crystal represented by (a) in the present invention can be obtained, for example, by subjecting the above-mentioned raw materials to dry grinding treatment. The crystals shown in (b) and (c) can be obtained, for example, by dry-milling the above-mentioned raw materials and then wet-milling them together with a milling medium in an appropriate solvent. Sand mill, planetary mill, ball mill, vibrating ball mill, co-ball mill,
Using an attritor, dyno mill, etc., by mechanically grinding together with grinding media in a solvent, wet mortar, automatic mortar, planetary mill, vibrating ball mill, vertical cylindrical vibrating mill, CF mill, kneader, etc. It can be carried out by dry milling by a mechanical treatment method, or by wet milling with a milling medium after dry milling, but it is not limited to these methods. Also,
In the dry grinding, if necessary, a grinding aid such as sodium chloride or sodium sulfate may be used. The processing time of dry grinding is preferably 2 hours or more.

Examples of the solvent used in the above wet grinding treatment include aliphatic alcohols such as methanol, ethanol, n-butanol, n-propanol and isopropanol, benzyl alcohol, phenethyl alcohol and α-phenylethyl alcohol. Aromatic alcohols, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, phenols such as phenol, cresol and catechol, aliphatic amides such as dimethylformamide and dimethylacetamide, sulfur derivatives such as dimethyl sulfoxide and propane sultone ,Ethyl acetate,
Esters such as butyl acetate, ketones such as methyl ethyl ketone and cyclohexanone, ethers such as diethyl ether, dimethyl ether and tetrahydrofuran, aliphatic halogenated hydrocarbons such as methylene chloride, aromatic halogenation such as chlorobenzene and dichlorobenzene A single solvent or a mixed solvent of two or more kinds can be appropriately selected from hydrocarbons, water and the like.

The amount of this solvent used is zinc tetra-2,3.
1 to 200 parts by weight of 1 part by weight of pyrazinoporphyrazine
Parts by weight, preferably 10 to 100 parts by weight. Also,
It is preferable to carry out the wet grinding treatment for 3 hours or more.
The treatment temperature is 0 ° C to the boiling point of the solvent or less, preferably 10 to 60 ° C. Zinc tetra-after the above treatment
The 2,3-pyrazinoporphyrazine crystal has a maximum primary particle diameter of 3 μm or less on the major axis and 2 μm or less on the minor axis, and when it is used as a photoconductive material for the photosensitive layer. Is preferably 1 μm or less on the major axis and 0.5 μm or less on the minor axis.

Next, an electrophotographic photosensitive member using the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained by the above processing method as a photoconductive material of the photosensitive layer will be described. The electrophotographic photoreceptor of the invention may have a single-layered photosensitive layer or a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer.

1 to 4 are sectional views each schematically showing an electrophotographic photosensitive member having a photosensitive layer having a laminated structure according to the present invention. In FIG. 1, a photosensitive layer including a charge generation layer 1 and a charge transport layer 2 laminated thereon is coated on a conductive support 3. FIG. 2 shows the laminated structure of FIG. 1 in which an undercoat layer 4 is provided between the charge generation layer 1 and the conductive support 3.
Is intervening. Further, FIG. 3 shows the laminated structure of FIG. 1 in which a protective layer 5 is further coated on the surface of the photosensitive layer. Further, FIG. 4 shows a structure in which a protective layer 5 is further laminated on the laminated structure of FIG.

Each layer of the electrophotographic photosensitive member will be described below in the case where the photosensitive layers of the electrophotographic photosensitive member of the present invention have a laminated structure. The charge generation layer 1 of the photosensitive layer is composed of the zinc tetra-2,3-pyrazinoporphyrazine crystal and the binder resin. This charge generation layer is prepared by dispersing zinc tetra-2,3-pyrazinoporphyrazine crystals in a solution prepared by dissolving a binder resin in an organic solvent to prepare a coating solution, which is then applied onto the conductive support 3. It is formed by applying. The binder resin to be used can be selected from a wide range of resins, for example, polyvinyl formal resin, polyvinyl acetal resin such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetoacetal. , Polyarylate resins (polycondensates of bisphenol A and phthalic acid, etc.), polycarbonate resins, polyester resins, modified polyether type polyester resins, phenoxy resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyvinyl acetate resins,
Polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, casein, vinyl chloride-vinyl acetate copolymer Coalescence, hydroxyl modified vinyl chloride-
Vinyl acetate copolymer, carboxyl modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, Examples of the insulating resin include silicone-alkyd resin and phenol-formaldehyde resin. Further, it can 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 can be used alone or in combination of two or more.

As the dispersion medium for dissolving the binder resin, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and benzyl alcohol, ketones such as acetone, MEK and cyclohexanone, DMF and dimethylacetamide. Amides, etc., sulfoxides, such as dimethyl sulfoxide, TH
Cyclic or linear ethers such as F, dioxane, diethyl ether, methyl cellosolve, ethyl cellosolve, esters such as methyl acetate, ethyl acetate, n-butyl acetate, methylene chloride, chloroform, carbon tetrachloride, dichloroethylene, trichloroethylene. Such as aliphatic halogenated hydrocarbons such as ligroin, mineral oil such as ligroin, aromatic hydrocarbons such as benzene, tolkene and xylene, halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, etc., alone or in combination of two or more kinds. Can be used.

The compounding ratio (weight) of zinc tetra-2,3-pyrazinoporphyrazine crystals and the binder resin is 40: 1 to.
It is in the range of 1:20, preferably 10: 1 to 1:10. If the ratio of zinc tetra-2,3-pyrazinoporphyrazine crystals is too high, the stability of the coating solution decreases,
On the other hand, if it is too low, the sensitivity of the photoreceptor will decrease, so
It is preferable to set it in the above range. Zinc tetra-2,
As a method for dispersing 3-pyrazinoporphyrazine crystals, a known method, for example, a ball mill, a sand grind mill, a planetary mill, a co-ball mill, a roll mill or the like can be used.

The zinc tetra-2,3-pyrazinoporphyrazine crystals can be mixed with the binder resin by, for example, adding the binder resin in a powder state or as a polymer solution at the same time as dispersing the crystals during the dispersion treatment. The method of mixing, the method of mixing the dispersion with the polymer solution of the binder resin, or the method of mixing the polymer solution with the dispersion on the contrary can be used. In addition, it is necessary that the dispersion does not change the crystal form of the zinc tetra-2,3-pyrazinoporphyrazine crystal. It was confirmed that there was no change from before dispersion.

The method for applying the coating solution to form the charge generation layer includes dip coating method, spray coating method, spinner coating method, bead coating method, wire bar coating method, blade coating method, roller coating method, An air knife coating method or a curtain coating method 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 is usually in the range of 0.05 to 5 μm, preferably 0.15 to 2.0 μm.

The charge transport layer 2 in the electrophotographic photoreceptor of the present invention is formed by including a charge transport material in an appropriate binder resin. As the charge transport material, for example, 2,5-
Bis- (p-diethylaminophenyl) -1,3,4-
Oxadiazole derivatives such as oxadiazole, 1,
3,5-triphenylpyrazoline, 1- [pyridyl-
(2)]-3- (p-Diethylaminostyryl) -5-
Pyrazoline derivatives such as (p-diethylaminophenyl) pyrazoline, aromatic tertiary monoamine compounds such as triphenylamine and benzylaniline, N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine and the like. Aromatic tertiary diamine compound, 3- (p-diethylaminophenyl) -5,6-di- (p-methoxyphenyl)-
1,2,4-triazine derivatives such as 1,2,4-triazine, 4-diethylaminobenzaldehyde, 2,2-
Hydrazone derivatives such as diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styrylquinazoline,
Benzofuran derivatives such as 6-hydroxy-2,3-di- (p-methoxyphenyl) benzofuran;
Examples of the electron donor include α-stilbene derivatives such as 2-diphenylvinyl) -N, N-diphenylaniline, triphenylmethane derivatives, and polymers having a group composed of these compounds in the main chain or side chain. However, the present invention is not limited to these. These charge transporting materials may be used alone or as a mixture of two or more kinds. When the charge transporting material is a polymer, a layer may be formed by itself.

The binder resin used for the charge transport layer 2 is
Polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-
Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin,
Examples thereof include the same resins as those used in the charge generation layer 1 such as phenol-formaldehyde resin, styrene-alkyd resin, and poly-N-vinylcarbazole resin.

The charge transport layer 2 is prepared in the same manner as in the coating method described above after the coating solution is prepared by using the same charge transport material, the binder resin, and the same organic solvent as that used in forming the charge generating layer. By the means described above, the coating liquid can be formed on the charge generation layer by coating. At that time, the charge transport material and the binder resin are mixed in a proportion of 5 to 500 parts by weight of the charge transport material with respect to 100 parts by weight of the binder resin. The thickness of the charge transport layer 2 is generally about 5 to 50 μm, preferably about 10 to 30 μm.

When the photosensitive layer of the present invention has a single layer structure, the photosensitive layer is a photoconductive layer in which zinc tetra-2,3-pyrazinoporphyrazine crystals and a charge transport material are dispersed in a binder resin. Become. As the charge transport material and the binder resin, the same materials as described above are used, and the photoconductive layer is formed in the same manner. In this case, the binder resin is preferably selected from at least one selected from polyvinyl acetal resins, vinyl chloride-vinyl acetate copolymers, phenoxy resins and modified ether type polyester resins. In addition, various additives such as an antioxidant and a sensitizer may be added to the photosensitive layer, if necessary. The compounding ratio (weight) of the charge transport material and the binder resin is 1: 2.
0-5: 1, the compounding ratio (weight) of zinc tetra-2,3-pyrazinoporphyrazine crystal and charge transport material is 1: 1.
It is preferably set to about 0 to 10: 1.

In the present invention, as the conductive support 3, any support can be used as long as it can be used as an electrophotographic photoreceptor. Specifically, metals such as aluminum, nickel, chromium, stainless steel, aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, plastic film coated with a thin film of ITO, or the like, or Examples thereof include paper and plastic film coated or impregnated with a conductivity-imparting agent. 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 such as graining. You may give a process etc.

An undercoat layer 4 may be further provided between the conductive support 3 and the photosensitive layer. As the undercoat layer,
For example, aluminum anodic oxide coating, aluminum oxide, inorganic layers such as aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyglutamic acid, starch, amino starch, polyurethane, polyimide,
Organic layer such as polyamide, zirconium chelate compound,
Well-known binder resins such as organic metals such as zirconium alkoxide compounds, titanyl chelate compounds and titanyl alkoxide compounds, and silane coupling agents are used.
The thickness of the undercoat layer is preferably in the range of 0.01 to 20 μm, and more preferably in the range of 0.05 to 10 μm.

If desired, the surface of the photosensitive layer may be further covered with a protective layer 5. The protective layer is formed by including a conductive material in a suitable binder resin. Examples of the conductive material include metallocene compounds such as dimethylferrocene, N, N'-diphenyl-N, N'-bis- (m
Aromatic amino compounds such as -tolyl) benzidine, and metal oxides such as antimony oxide, tin oxide, titanium oxide, indium oxide, and tin oxide-antimony oxide can be used, but are not limited thereto. Further, as the binder resin used for the protective layer, for example, those exemplified as the binder resin can be used. Further, it is preferable that the protective layer is configured to have an electric resistance of 10 ⁹ to 10 ¹⁴ Ωcm. Electric resistance is 10 ¹⁴
When it is higher than Ωcm, the residual potential is increased and a copy having a lot of fog is produced, while when it is lower than 10 ⁹ Ωcm, image blurring, reduction of resolution and the like occur. Further, the protective layer must be configured so as not to substantially impede the transmission of the light irradiated with the resolution light. The thickness of this protective layer is
A range of 0.5 to 20 μm, preferably a range of 1 to 10 μm is suitable.

[0029]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, all “parts” mean “parts by weight”. Synthesis Example (Synthesis of Zinc Tetra-2,3-Pyrazinoporphyrazine) Under a nitrogen atmosphere, at room temperature, 8.3 parts of zinc acetate was added to 230 parts of quinoline, and then 30 parts of 1,3-dicyanopyrazine were added, After reacting at 200 ° C. for 4 hours, the product was filtered while hot, washed with dimethylformamide (DMF) and methanol under hot suspension, and then washed with acetone and distilled water. Then, the obtained wet cake was dried under reduced pressure to obtain 23.3 parts of zinc tetra-2,3-pyrazinoporphyrazine crystals. The powder X-ray diffraction pattern of the obtained zinc tetra-2,3-pyrazinoporphyrazine crystal is shown in FIG. In the present invention, the powder X-ray diffraction pattern of each crystal is Rigaku manufactured by Rigaku Denshi Co., Ltd.
It was measured using a Rotaflex X-ray diffractometer at a cathode voltage of 40 kV and a cathode current of 30 mA.

Example 1 3.0 parts of the zinc tetra-2,3-pyrazinoporphyrazine crystals obtained in the synthesis example were placed in an automatic mortar (Yamato Scientific Co., Ltd.,
LANBO-MILL MODEL UT21 type) for 12 hours by dry grinding to give zinc tetra-
Crystals of 2,3-pyrazinoporphyrazine were obtained. The powder X-ray diffraction pattern of the obtained zinc tetra-2,3-pyrazinoporphyrazine crystal is shown in FIG. 6, and the Bragg angle (2θ ± 0.2 °) has a diffraction peak at 27.0 °. It was a crystal having.

Example 2 0.3 part of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 1 was added to 1 mmφ glass beads 40.
With 40 parts at room temperature in 40 parts of methanol by ball milling for 24 hours, then the glass beads and the dispersion liquid are separated, and the dispersion liquid is centrifuged with a centrifugal sedimentation machine (KONTRON / HER).
MLE, CENTRIKON H-401), and the resulting wet cake is dried under reduced pressure to give zinc tetra-2,3-pyrazinoporphyrazine crystals 0.26
Got a part. The powder X-ray diffraction pattern of the obtained zinc tetra-2,3-pyrazinoporphyrazine crystal is shown in FIG. 7, and the Bragg angle (2θ ± 0.2 °) was at least 7.4 °, 11 .3 °, 17.8 °, 19.3 °, 2
It was a crystal having major diffraction peaks at 7.1 ° and 28.6 °.

Example 3 0.3 part of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 1 was added to 1 mmφ glass beads 40.
2 parts in 40 parts of monochlorobenzene at room temperature
After ball milling for 4 hours, the glass beads and the dispersion are separated, and the dispersion is centrifuged (KONTRON).
/ HERMLE, CENTRIKON H-40
After 1), the obtained wet cake was washed with 10 parts of monochlorobenzene and dried under reduced pressure to obtain 0.25 parts of zinc tetra-2,3-pyrazinoporphyrazine crystals. The powder X-ray diffraction pattern of the obtained zinc tetra-2,3-pyrazinoporphyrazine crystal is shown in FIG.
Bragg angle (2θ ± 0.2 °) is at least 27.
It was a crystal having a main diffraction peak at 9 °.

Example 4 1.0 part of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 1 was added to 1 part of polyvinyl butyral resin (Sekisui Chemical Co., Ltd., S-REC BM-1) and butyl acetate. After mixing with 100 parts and dispersing it with 250 parts of 1/8 inch steel balls for 2 hours using a paint shaker, the obtained coating solution is applied onto an aluminum substrate by a dip coating method, and at 100 ° C. It was heated and dried for 10 minutes to form a charge generation layer having a film thickness of 0.18 μm. Next, N represented by the following structural formula (1),
1,1′-di- (p-phenylene) cyclohexanecarbonate 3 represented by 2 parts of N′-diphenyl-N, N′-bis (m-tolyl) benzidine and a repeating structural unit represented by the following structural formula (2) Parts are dissolved in 20 parts of chlorobenzene, and the resulting coating solution is applied onto the charge generation layer formed above by a dip coating method, and the mixture is applied at 115 ° C. for 1 hour.
By heating for an hour to form a charge transporting layer having a film thickness of 20 μm, an electrophotographic photosensitive member was produced.

[0034]

Embedded image

Example 5 Instead of the zinc tetra-2,3-pyrazinoporphyrazine crystal used in Example 4, the zinc tetra-2,3-pyrazinoporphyrazine crystal 1.0 obtained in Example 2 was used. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the parts were used. Example 6 Instead of the zinc tetra-2,3-pyrazinoporphyrazine crystal used in Example 4, 1.0 part of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 3 was used. An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that the above was used.

Comparative Example Instead of the zinc tetra-2,3-pyrazinoporphyrazine crystal used in Example 4, the zinc tetra-obtained in the synthesis example was used.
An electrophotographic photosensitive member was produced in the same manner as in Example 4 except that 1.0 part of 2,3-pyrazinoporphyrazine crystal was used.

(Measurement and Evaluation of Electrophotographic Photosensitive Member) The electrical characteristics of the electrophotographic photosensitive members produced in the above Examples 4 to 6 and Comparative Example were measured as follows. Using an electrostatic copying paper tester (Kawaguchi Electric Co., Ltd., Electrostatic Analyzer EPA-8100), normal temperature and normal humidity (20 ° C,
After charging the photoreceptor by corona discharge of -6 kV in an environment of 50% RH), tungsten lamp light is dispersed into monochromatic light of 780 nm using a monochromator, and 1 μW / cm ² on the photoreceptor surface. It was adjusted so that Then, the half-exposure amount E1 / 2 (μJ / cm ² ) until the initial surface potential V0 becomes 1/2 is measured, and then 10 lux of tungsten light is irradiated on the surface of the photoconductor for 1 second to obtain the residual potential VR. (Volt) was measured.
Further, the attenuation rate DDR (%) was also measured. In addition, VO after repeating the above charging and exposure 2000 times
, E1 / 2, DDR and VR were also measured. Table 1 shows the results.

[0038]

[Table 1]

[0039]

INDUSTRIAL APPLICABILITY The zinc tetra-2,3-pyrazinoporphyrazine crystal of the present invention has a novel crystal form, has high sensitivity, and has excellent electrical characteristics such as low residual potential. It is also extremely useful as a photoconductive material of an electrophotographic photosensitive member which is excellent in durability such as repeated stability. Further, the electrophotographic photosensitive member produced by using those crystals has excellent electrical characteristics and durability and can be used as a photosensitive member for laser printers and the like.

[Brief description of the drawings]

FIG. 1 is 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 is another schematic cross-sectional view of the electrophotographic photosensitive member according to the invention.

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

FIG. 5 shows a powder X-ray diffraction pattern of zinc tetra-2,3-pyrazinoporphyrazine crystals obtained in Synthesis Example.

FIG. 6 shows a powder X-ray diffraction diagram of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 1.

FIG. 7 shows a powder X-ray diffraction pattern of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 2.

FIG. 8 shows a powder X-ray diffraction pattern of the zinc tetra-2,3-pyrazinoporphyrazine crystal obtained in Example 3.

[Explanation of symbols]

1 ... Charge generating layer, 2 ... Charge transporting layer, 3 ... Conductive support,
4: Undercoat layer, 5: Protective layer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Yamazaki 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Yasuhiro Yamaguchi 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd.

Claims (3)

[Claims] 1. A crystal having a diffraction peak at a Bragg angle (2θ ± 0.2 °) of at least 27.0 ° in an X-ray diffraction spectrum for CuKα rays, 7.4 °, 1
A crystal having major diffraction peaks at 1.3 °, 17.8 °, 19.3 °, 27.1 ° and 28.6 °, or
Zinc tetra-, which is a crystal selected from crystals having a main diffraction peak at least at 27.9 °
2,3-pyrazinoporphyrazine crystals. 2. Zinc tetra-2,3- according to claim 1.
A photoconductive material for an electrophotographic photoreceptor, comprising a pyrazinoporphyrazine crystal. 3. A conductive support is coated with a photosensitive layer containing at least one kind of the zinc tetra-2,3-pyrazinoporphyrazine crystal according to claim 1. Description: Electrophotographic photoreceptor.