JPH0784390A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To provide an electrophotographic photoreceptor excellent in the repetition stability of an electric characteristic. CONSTITUTION:An electrophotographic photosensitive layer contains a chlorogallium phthalocyanine crystal as charge generating material, a triarylamine compound, expressed by a formula I, as charge transport material, and an antioxidant. In the formula I, Ar1, Ar2 respectively represent alkyl, phenyl, alkoxy, or a phenyl group allowd to be substituted by alkyl substituted phenyl, a polycyclic aromatic group allowed to be substituted by an alkyl group, or an aromatic hetorocyclic group. In the formula II, R1, R1' can be either the same or different and respectively represnt a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, R2, R2' and R3, R3' can be either the same or different and respectively represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a substituted amino group, and (m) and (n) respectively represent 1 or 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more specifically, it uses a specific compound as a charge generating material and a charge transporting material, and has photosensitivity, printing characteristics, abrasion resistance, cleaning ability, and The present invention relates to a highly durable electrophotographic photoreceptor having excellent environmental stability.

[0002]

2. Description of the Related Art Conventionally, phthalocyanine compounds have been used in paints,
It is a substance useful as a printing ink, a catalyst or an electronic material, and in recent years, in particular, it has been extensively studied as an electrophotographic photosensitive material, an optical recording material and a photoelectric conversion material. Generally, phthalocyanine compounds are known to show a large number of crystal forms due to differences in production method and treatment method,
It is also known that the difference in crystal form has a great influence on the photoelectric conversion characteristics of phthalocyanine. Regarding the crystal form of the phthalocyanine compound, for example, looking at copper phthalocyanine, in addition to the stable β form, α,
Crystal forms such as π, χ, ρ, γ, and δ are known, and it is known that these crystal forms can be mutually transformed by mechanical strain force, sulfuric acid treatment, organic solvent treatment, heat treatment, etc. (For example, US Pat. Nos. 2,770,629, 3,160,635, and 3,70).
No. 8,292 and No. 3,357,989. Further, JP-A-50-38543 describes the difference in crystal form of copper phthalocyanine and the electrophotographic sensitivity. In addition to copper phthalocyanine, it has been proposed to use various crystal types of metal-free phthalocyanine, hydroxygallium phthalocyanine, chloroaluminum phthalocyanine, chloroindium phthalocyanine, etc. for electrophotographic photoreceptors. Regarding the crystal form and electrophotographic characteristics of chlorogallium phthalocyanine, JP-A-1-221459 describes chlorogallium phthalocyanine having a specific Bragg angle and an electrophotographic photosensitive member using the same. In addition, the present inventors have conducted various studies from the viewpoint of various phthalocyanine crystals and electrophotographic characteristics, and found three new crystal types of chlorogallium phthalocyanine, and found that these are excellent as electrophotographic photoreceptors. Proposed (Japanese Patent Application No. 4-27449). However, when these chlorogallium phthalocyanines are used as a photosensitive material, the photosensitivity and durability of the electrophotographic photosensitive member are not yet sufficiently satisfactory, and in the production,
There are various problems such as the crystal type conversion operation is complicated and the control of the crystal type is difficult.

On the other hand, various proposals have been made for charge transport materials. For example, JP-A-62-247374 discloses a benzidine compound, and JP-A-55-59483, JP-A-57-195254, JP-A-2-178668 and JP-A-2-19086.
No. 2, JP-A No. 3-101739, and No. 3-1277.
Japanese Patent Publication No. 65 discloses a method for synthesizing a triarylamine compound and its application to an electrophotographic photoreceptor. Furthermore, many proposals have been made regarding the combined use of a charge generating material and a charge transporting material, for example, JP-A-57-54942 and JP-A-6-54942.
0-59355, 61-203461,
JP-A-62-67094 and JP-A-62-47054 propose combinations with phthalocyanine pigments.

[0004]

As described above, various photosensitive layer forming materials have been conventionally developed, but in order to provide an excellent electrophotographic photosensitive member that can be put to practical use, sensitivity, Various properties such as receptive potential, potential holding property, potential stability, residual potential, electrophotographic characteristics such as spectral characteristics, mechanical durability such as abrasion resistance, chemical stability against heat, light, discharge products, etc. Is required. Among them, it is particularly important that the composition has high sensitivity and excellent repeatability. In order to obtain such electrophotographic characteristics, 1) the charge generating material efficiently generates charges with respect to absorbed light, and 2) the generated charges are smoothly injected into the charge transporting material from the charge generating material. All of the four conditions, that is, 3) being chemically and photochemically stable, and 4) allowing the charges injected into the charge transport material to move at high speed in the charge transport layer, are used as indicators. In addition to the above four conditions, studies have also been conducted on materials having mechanical durability. However, regarding combinations of conventionally proposed charge generation materials and charge transport materials,
No product satisfying all of the above conditions has been obtained. The present invention has been made in view of the above-mentioned actual situation in the conventional technique. That is, an object of the present invention is to provide an electrophotographic photosensitive member having high sensitivity, particularly very high sensitivity to near-infrared light for semiconductor laser, and excellent in repeated stability.

[0005]

The present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer containing a chlorogallium phthalocyanine crystal as a charge generating material, and charge transporting. The material is characterized by containing at least a triarylamine compound represented by the following general formula (I) and a benzidine compound represented by the following general formula (II).

[0006]

[Chemical 3] (In the formula, Ar ₁ and Ar ₂ are each a phenyl group optionally substituted by alkyl, phenyl, alkoxy, or alkyl-substituted phenyl, a polycyclic aromatic group optionally substituted by an alkyl group, or an aromatic heterocyclic group. Represents a ring group.)

[0007]

[Chemical 4] (In the formula, R ₁ and R ₁ ′ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ₂ , R ₂ ′, R ₃ and R ₃ ′ are They may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a substituted amino group, and m and n each represent 1 or 2.)

In the present invention, the photosensitive layer has a layer structure in which the charge-generating layer and the charge-transporting layer are functionally separated, and the charge-generating layer contains chlorogallium phthalocyanine crystals, and the charge-transporting layer has the above-mentioned general formula. It is preferable to contain the triarylamine compound represented by (I) and the benzidine compound represented by the general formula (II). In the electrophotographic photoreceptor of the present invention, it is preferable that the photosensitive layer further contains a hindered phenol or hindered amine as an antioxidant. By adding these antioxidants, it is possible to suppress the occurrence of image quality defects and obtain an electrophotographic photoreceptor suitable for high-quality copying machines.

The layers constituting the electrophotographic photosensitive member of the present invention will be described in detail below. 1 (a) to (f)
FIG. 3 is a schematic sectional view of an electrophotographic photosensitive member of the present invention. 1A to 1D show a case where the photosensitive layer has a laminated structure, in which the charge generation layer 1 is provided on the conductive support 3, and the charge transport layer 2 is provided thereon. ing. Figure 1
In (b), an undercoat layer is further provided on the conductive support 3, and in FIG. 1 (c), a protective layer 5 is provided on the surface. Further, in FIG. 1D, both the undercoat layer 4 and the protective layer 5 are provided. 1E and 1F show a case where the photosensitive layer has a single-layer structure, in which the photoconductive layer 6 is provided on the conductive support 3, and in FIG. , Further undercoat layer 4
Is provided.

In the following, the case where the photosensitive layer has a laminated structure will be mainly described. As the conductive support, metals such as aluminum, nickel, chromium and stainless steel, and a plastic film provided with a thin film of aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, ITO, etc. Etc., or paper and plastic film coated or impregnated with a conductivity-imparting agent. These conductive supports are used in a suitable shape such as a drum shape, a sheet shape, a plate shape, but are not limited thereto. Further, if necessary, the surface of the conductive support can be subjected to various treatments within a range that does not affect the image quality. For example, surface oxidation treatment, chemical treatment, coloring treatment, or irregular reflection treatment such as graining can be performed.

An undercoat layer may be provided between the conductive support and the charge generation layer. This undercoat layer prevents injection of charges from the conductive support to the photosensitive layer during charging of the photosensitive layer, and also acts as an adhesive layer for integrally adhering and holding the photosensitive layer to the conductive support. Or, depending on the case, it exhibits a function of preventing the reflected light of light from the conductive support. The resin and other materials constituting the undercoat layer include polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, chloride resin. Vinylidene resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, water-soluble polyester resin, nitrocellulose, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, polyacrylic acid, polyacrylamide, Known materials such as zirconium chelate compounds, titanyl chelate compounds, titanyl alkoxide compounds and other organic titanyl compounds, and silane coupling agents can be used. The thickness of the undercoat layer is 0.01 to 10 μm, preferably 0.05 to
2 μm is suitable. As a coating method, a usual method 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 charge generation layer is formed by dispersing a chlorogallium phthalocyanine crystal, which is a charge generation material, in a binder resin. As the chlorogallium phthalocyanine crystal, the Bragg angle (2
θ ± 0.2 °) is (1) 7.4 °, 16.6 °, 2
Having strong diffraction peaks at 5.5 ° and 28.3 °, (2) 6.8 °, 17.3 °, 23.6 ° and 2
Having a strong diffraction peak at 6.9 °, (3) 8.7
Those having strong diffraction peaks at ° to 9.2 °, 17.6 °, 24.0 °, 27.4 ° and 28.8 ° are mentioned. These chlorogallium phthalocyanine crystals are
It can be produced by various known methods. That is, the chlorogallium phthalocyanine crystal obtained by the synthesis can be produced by mechanically pulverizing it using a ball mill, a mortar, a sand mill, a kneader or the like. If a grinding aid such as sodium chloride or sodium sulfate is used during the pulverization, the crystalline form can be converted to the above-mentioned crystal form having a uniform particle size very efficiently. The grinding aid is used in an amount of 0.5 to 20 times, preferably 1 to 10 times the chlorogallium phthalocyanine crystal. After the grinding, for example, if the phthalocyanine crystal is treated with an organic solvent such as toluene, methyl ethyl ketone, methylene chloride, tetrahydrofuran, benzyl alcohol, the crystallinity and particle size are further adjusted, and the most preferable chlorogallium phthalocyanine crystal of the present invention is obtained. be able to. The solvent treatment may be performed while milling with a grinding medium such as glass beads, steel beads, and alumina beads, if necessary.

The binder resin in the charge generation layer can be selected from a wide range of insulating resins. In addition, poly-N-vinylcarbazole, polyvinyl anthracene,
It can also be selected from organic photoconductive polymers such as polyvinylpyrene and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenol resin,
Vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, and the like can be mentioned. It is not limited to. These binder resins may be used alone or in combination of two or more.

The compounding ratio (weight ratio) of chlorogallium phthalocyanine and the binder resin is in the range of 40: 1 to 1:20, preferably 10: 1 to 1:10. As a method of dispersing using the above components, a usual method such as a ball mill dispersion method, an attritor dispersion method or a sand mill dispersion method can be adopted. At this time, a condition is required in which the crystal form of the chlorogallium phthalocyanine does not change due to dispersion. By the way, it has been confirmed that in any of the above dispersion methods carried out in the present invention, the crystal form does not change from that before dispersion. Further, in dispersing these, it is effective to make the particles finer to a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. In addition, as a solvent used for dispersing these, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, acetic acid n-
Commonly used organic solvents such as butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, monochlorobenzene, and toluene can be used alone or in combination of two or more. The thickness of the charge generation layer used in the present invention is generally 0.1 to 5 μm, preferably 0.2 to 2.0 μm. As a coating method for forming the charge generation layer, a dip coating method, a spray coating method, a Meyer bar coating method,
A blade coating method, a bead coating method, an air knife coating method, a curtain coating method and the like can be used. It is also effective to add a known acceptor to the charge generation layer in order to increase sensitivity and stability.

In the electrophotographic photoreceptor of the present invention, the charge transport layer comprises, as a charge transport material, at least one triarylamine compound represented by the general formula (I) and a benzidine represented by the general formula (II). At least one of the compounds
Seed and an essential component are contained in the binder resin, and an antioxidant is added as necessary. Specific examples of the triarylamine compound represented by the general formula (I) used in the present invention are shown in Tables 1 to 4 and the general formula (I
Specific examples of the benzidine compound represented by I) are shown in Table 5 and Table 6, respectively.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

[0020]

[Table 5]

[0021]

[Table 6]

In the present invention, the charge transport layer may further contain other triarylamine compounds in addition to the triarylamine compounds represented by the general formula (I). The triarylamine compounds that can be used are those represented by the following general formula (III), and specifically, those shown in Tables 7 to 9 can be exemplified.

[Chemical 5] (In the formula, Ar ₃ and Ar ₄ each represent a phenyl group or a naphthyl group which may be substituted with alkyl, phenyl, alkoxy, or alkyl-substituted phenyl,
R ₄ represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group, and k represents an integer of 0 to 2. )

[0023]

[Table 7]

[0024]

[Table 8]

[0025]

[Table 9]

The mixing ratio of the triarylamine compound as the charge transport material and the benzidine compound is in the range of 10:90 to 90:10 by weight, but the ratio of the triarylamine compound is less than 30. In this case, abrasion resistance, cleaning performance, and sliding noise with the cleaning member may cause problems, so 30:70 to 90:10.
It is desirable to set the range to. When a compound other than the compound represented by the general formula (I) is used in combination as the triarylamine compound, the ratio of the triarylamine compound represented by the general formula (I) is all triaryl. It is necessary to be 10% by weight or more of the system amine compound, but if it is less than 25% by weight, the repeating stability in electrical characteristics will be lowered, so it is preferably 25% by weight or more.

In the present invention, the mixing ratio of the total amount of the triarylamine compound and the benzidine compound and the binder resin may be in the range of 30:70 to 60:40 by weight. In order to maintain good abrasion resistance, cleaning property, slidability with a cleaning member, etc., it is preferable to use it in the range of 35:65 to 50:50.

The charge transport layer preferably contains a hindered amine compound or a hindered phenol compound as an antioxidant. The effects of hindered amine compounds and hindered phenol compounds are
Generally known compounds can be widely used because they are not affected by the modifying substituents. Specific examples of the hindered amine compound include octylated diphenylamine and 4,4′-bis (α, α′-dimethylbenzyl).
Diphenylamine, N, N'-diphenyl-p-phenylenediamine, N-isopropyl-N'-phenyl-p
-Phenylenediamine, N-1,3-dimethyl-N'-
Phenyl-p-phenylenediamine, N-1-methylheptyl-N'-phenyl-p-phenylenediamine, N
-(3-methacryloyloxy-2-hydroxypropyl) -N'-phenyl-p-phenylenediamine, 2,
2,4-Trimethyl-1,2-dihydroquinoline polymer, 6-ethoxy-2,2,4-trimethyl-1,2-
Examples include dihydroquinoline, diphenylamine derivatives, and alkylated diphenylamine.

Specific examples of the hindered phenol compound include triethylene glycol-bis [3-
(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2 , 4-Bis (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-di) -T-butyl-4-hydroxyphenyl) propionate], 2,2
-Thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N , N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester,
1,3,5-Trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene, bis (3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl) calcium, tris (3,5
-Di-t-butyl-4-hydroxybenzyl) isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6
-Di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, styrenated phenol, 2,2'-methylenebis (4-methyl-6-t)
-Butyl-phenol), 2,2'-methylenebis (4
-Ethyl-6-t-butyl-phenol), 4,4'-
Butylidene bis (3-methyl-6-t-butyl-phenol), 2,5-di-t-butylhydroquinone, 2,5
-Di-t-amylhydroquinone, 2-t-butyl-6-
(3-Butyl-2-hydroxy-5-methylbenzyl)
-4-methylphenyl acrylate, 2- [1- (2-
Hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, 4,4'-butylidene bis (3-methyl-6-t-)
Butylphenol), 4,4'-thiobis (3-methyl-6-t-butyl-phenol), 4,4'-thiobis (2-methyl-6-t-butylphenol), 3,9-
Bis {2- [3- (3-t-butyl-4-hydroxy-
5-Methylphenyl) propionyloxy] -1,1-
Examples include dimethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, alkylated bisphenols, and phenol derivatives.

The total amount of the antioxidant added may be adjusted so as to fall within the range of 0.07% by weight to 10% by weight of the whole layer to be added, but in order not to impair the mechanical properties of the layer. Is preferably added so that the total amount of all the charge transport materials and the antioxidant does not exceed 55% by weight of the entire layer containing the same. Also, in order to suppress the occurrence of image quality defects, the total amount of the charge transport material should not be less than 1/200 times.

As the binder resin used for the charge transport layer, 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, phenol-formaldehyde resin, Known resins such as styrene-alkyd resin, poly-N-vinylcarbazole, and polysilane can be used, but are not limited to these. Among these binder resins, the polycarbonate resins represented by the following structural formulas (IV) to (IX) or the polycarbonate resins obtained by copolymerizing the repeating structural units constituting them are used alone or in combination of two or more. In that case, compatibility with the charge transport material and the like is good, a uniform film is obtained, and particularly good characteristics are exhibited.
As the molecular weight of the polycarbonate resin, those having a viscosity average molecular weight of 10,000 to 100,000, preferably 10,000 to 50,000 can be used.

[0032]

[Chemical 6] (N 'means the degree of polymerization within the above molecular weight range.)

In the present invention, additives can be added when the above-mentioned photosensitive layer is formed, mainly for the purpose of obtaining good surface properties. As this type of additive, those known as modifiers for paints can be used. For example, alkyl-modified silicone oil such as dimethyl silicone oil and aromatic-modified silicone oil such as methylphenyl silicone oil are preferable examples. These additives are based on the solid content of the charge transport layer,
1 to 10,000 ppm, preferably 5 to 2,000 p
pm may be added.

The charge transport layer is prepared by applying a coating solution containing the constituent materials (charge transport material, antioxidant, binder resin, etc.) and a suitable solvent, and removing the solvent by evaporation. Examples of the solvent used when providing the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, halogenated fats such as methylene chloride, chloroform and ethylene chloride. Organic solvents such as group hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, ethyl ether and dioxane may be used alone or in combination of two or more. As a coating method for providing the charge transport layer, known methods such as a blade coating method, a Mayer 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 may be used. it can. The thickness of the charge transport layer is 5 to 50 μm.
m, preferably 10 to 30 μm.

When the photosensitive layer of the electrophotographic photosensitive member of the present invention has a single layer structure, the charge generating material and the charge transporting material are the same as those used when the photosensitive layer has a laminated structure, and the binder resin is used. As the above, the polycarbonate resin described in the charge transport layer is used. The polycarbonate resin may contain 50% by weight or less of the other binder resin described in the charge generation layer and the charge transport layer.

If necessary, a protective layer may be provided on the charge transport layer. The protective layer is useful for preventing chemical alteration of the charge transport layer during charging of the photosensitive layer and improving mechanical strength of the photosensitive layer.

[0037]

EXAMPLES In the following examples and comparative examples, "part"
Means "parts by weight". Synthesis Example 1 30 parts of 1,3-diiminoisoindoline and 9.1 parts of gallium trioxide were placed in 290 parts of quinoline and heated to 200 ° C.
After reacting for 3 hours in, the product was filtered off, washed with acetone and methanol, and then 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. Synthetic Example 2 3.0 parts of the chlorogallium phthalocyanine crystal obtained in Synthetic Example 1 was added to an automatic mortar (Lab-Mill UT-21).
Type, manufactured by Yamato Scientific Co., Ltd.) for 3 hours. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Synthesis Example 3 0.5 part of the chlorogallium phthalocyanine crystal obtained in Synthesis Example 2 was mixed with 60 parts of glass beads (1 mmφ) at room temperature in 20 parts of a mixed solvent of water / chlorobenzene 1:10 parts for 24 hours. After the ball milling treatment, it was separated by filtration, 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. Synthetic Example 4 0.5 part of the chlorogallium phthalocyanine crystal obtained in Synthetic Example 2 together with 60 parts of glass beads (1 mmφ) was subjected to ball milling in 20 parts of methylene chloride at room temperature for 24 hours, filtered and separated with methanol. It was washed with 10 parts and dried to obtain chlorogallium phthalocyanine crystals. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG. Synthetic Example 5 0.5 part of the chlorogallium phthalocyanine crystal obtained in Synthetic Example 2 together with 60 parts of glass beads (1 mmφ) was ball-milled in 20 parts of methanol at room temperature for 24 hours, filtered and separated with methanol 10 Partly washed and dried to obtain chlorogallium phthalocyanine crystals. The powder X-ray diffraction pattern of the obtained chlorogallium phthalocyanine crystal is shown in FIG.

Example 1 10 parts of a zirconium compound (Organics ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 1 part of a silane compound (A1110, manufactured by Nippon Unicar Co.) on an aluminum substrate and i
A solution consisting of 40 parts of propanol and 20 parts of butanol was applied by a dip coating method and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer having a film thickness of 0.5 μm. Next, 1 part of the chlorogallium phthalocyanine crystal obtained in Synthesis Example 3 was mixed with 1 part of polyvinyl butyral resin (S-REC BM-3, manufactured by Sekisui Chemical Co., Ltd.) and acetic acid n-.
After mixing with 100 parts of butyl and treating with glass beads for 1 hour with a paint shaker to disperse, the obtained coating liquid is applied onto the above-mentioned undercoat layer by a dip coating method,
Heat dried at 00 ° C for 10 minutes, film thickness 0.15 μm
The charge generation layer of 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. Next, a triarylamine compound (the exemplified compound N
o. I-13) 6 parts, benzidine compound (Exemplified compound No. II-27) 2.5 parts, polycarbonate resin (Exemplified structural formula (VI): viscosity average molecular weight Mv: 30,
000) 10 parts and 2,6-di-t-butyl-4-methylphenol 1 part were dissolved in monochlorobenzene 80 parts, and the resulting coating solution was applied onto the charge generation layer by a dip coating method, It was heated and dried at 115 ° C. for 1 hour to form a charge transport layer having a film thickness of 20 μm.

Examples 2 to 7 and Comparative Examples 1 to 5 Triarylamine compounds, benzidine compounds and antioxidants shown in Table 10 below were used, and electrons were prepared by the same method as in Example 1 above. A photographic photoreceptor was made

[0041]

[Table 10]

The electrophotographic photoconductors obtained in the above-mentioned Examples and Comparative Examples were used as digital copying machines (Able 330).
1. Fuji Xerox Co., Ltd.) (partially modified for potential / light quantity measurement), and as initial characteristics, the initial charging potential V0,
The half-exposure amount E1 / 2 and the residual potential VRP were investigated, and the above-mentioned characteristic value change amount and image quality defect after copying 30,000 sheets (A4) were examined. The results are shown in Table 11. The evaluations at the initial stage and at the time of copying 30,000 sheets were carried out in a normal temperature and normal humidity environment, and copying was repeated under conditions including various environments (low temperature and low humidity, high temperature and high humidity).

[0043]

[Table 11]

[0044]

The electrophotographic photosensitive member of the present invention uses a combination of a specific charge generating material and a specific charge transporting material as described above, and thus has high sensitivity and excellent repeated stability and image quality. No defects will occur.

[Brief description of drawings]

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

FIG. 2 shows a powder X-ray diffraction diagram of a chlorogallium phthalocyanine crystal obtained in Synthesis Example 1.

FIG. 3 shows a powder X-ray diffraction diagram of a chlorogallium phthalocyanine crystal obtained in Synthesis Example 2.

FIG. 4 shows a powder X-ray diffraction diagram of a chlorogallium phthalocyanine crystal obtained in Synthesis Example 3.

FIG. 5 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Synthesis Example 4.

FIG. 6 shows a powder X-ray diffraction pattern of the chlorogallium phthalocyanine crystal obtained in Synthesis Example 5.

[Explanation of symbols]

1 ... Charge generating layer, 2 ... Charge transporting layer, 3 ... Conductive support,
4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photoconductive layer.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Toru Ishii Toru Ishii 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Kiyokazu Mashita 1600 Takematsu, Minamiashigara-shi, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Takahiro Suzuki 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Fuji Xerox Co., Ltd.

Claims (5)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the photosensitive layer contains a chlorogallium phthalocyanine crystal as a charge generating material, and at least a compound represented by the following general formula ( An electrophotographic photoreceptor comprising a triarylamine compound represented by I) and a benzidine compound represented by the following general formula (II). [Chemical 1] (In the formula, Ar ₁ and Ar ₂ are each a phenyl group optionally substituted by alkyl, phenyl, alkoxy, or alkyl-substituted phenyl, a polycyclic aromatic group optionally substituted by an alkyl group, or an aromatic heterocyclic group. Represents a ring group.) (In the formula, R ₁ and R ₁ ′ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and R ₂ , R ₂ ′, R ₃ and R ₃ ′ are They may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group or a substituted amino group, and m and n each represent 1 or 2.) 2. A chlorogallium phthalocyanine crystal,
In the X-ray diffraction spectrum, the Bragg angle (2θ ±
The electrophotographic photosensitive member according to claim 1, which is a chlorogallium phthalocyanine crystal having a strong diffraction peak at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° of 0.2 °). 3. A chlorogallium phthalocyanine crystal,
In the X-ray diffraction spectrum, the Bragg angle (2θ ±
The electrophotographic photosensitive member according to claim 1, which is a chlorogallium phthalocyanine crystal having a strong diffraction peak at 6.8 °, 17.3 °, 23.6 ° and 26.9 ° of 0.2 °). 4. A chlorogallium phthalocyanine crystal,
In the X-ray diffraction spectrum, the Bragg angle (2θ ±
0.2 °) of 8.7 to 9.2 °, 17.6 °, 24.0.
A chlorogallium phthalocyanine crystal having strong diffraction peaks at °, 27.4 ° and 28.8 °.
The electrophotographic photosensitive member described. 5. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains a hindered phenol or a hindered amine as an antioxidant.