JPH06100838B2 - Electrophotographic photoreceptor - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrophotographic photosensitive member that is preferably used in an image forming apparatus such as a copying machine.

(Prior Art) In recent years, as an electrophotographic photosensitive member having a photosensitive layer formed on a conductive substrate, an organic photosensitive member is used which has good processability and is advantageous in terms of manufacturing cost and has a large degree of freedom in functional design. Has been done. The above-mentioned organic photoreceptor has a photosensitive layer in which a charge generating function and a charge transporting function are separated by a charge generating material that generates a charge by light irradiation and a charge transporting material that transports the generated charge, thereby improving the sensitivity. There is known a function-separated type electrophotographic photoreceptor for achieving the above-mentioned purpose. The photosensitive layer of the function-separated electrophotographic photoreceptor is a laminated photoreceptor in which a charge generation layer containing at least a charge generation material and a charge transport layer containing a charge transport material and a binder resin are laminated. In addition, various types of single-layer type photoreceptors in which a charge generating material and a charge transporting material are dispersed in a binder resin have been proposed.

Since the above-mentioned multi-layer type photoconductor separates various functions from each other by the charge generation layer and the charge transport layer, it has an advantage that it has a high sensitivity and a wide selection range of the photosensitive material, unlike the single-layer type photoconductor.

By the way, the charge-transporting material is often of the hole-transporting type, and in order to provide the surface with durability, the charge-generating layer is provided on the conductive substrate, and the charge-transporting layer is further provided on the charge-generating layer. It is common to take the structure of a photoreceptor. However, in such a negative charging laminated type photoreceptor, ozone is generated in the atmosphere at the time of negative charging to cause deterioration of the photoreceptor and pollution of the copying environment, and at the time of development, it is difficult to produce a positively charging toner. There are problems such as need.

On the other hand, the above-mentioned single-layer type photoreceptor can be positively charged, and a negatively chargeable toner can be used as a toner for developing an electrostatic latent image on the photoreceptor. This is advantageous because, in general, it is easy to obtain a toner that is negatively charged, so that the selection range of toner materials is wide and various toner materials can be used. However, since electrons and holes are moved in one layer, one of them becomes a trap and the residual potential tends to increase. In addition, there is a problem that the combination of the charge generating material and the charge transporting material greatly affects the electrophotographic characteristics such as charging characteristics, sensitivity and residual potential.

Therefore, in an attempt to increase the sensitivity of a single-layer type photoreceptor in view of the above problems, N, N′-dimethylperylene-3,4,9,10-tetracarboxydiimide, N, N ′ as a charge generation pigment is used.
-Di (3,5-dimethylphenyl) perylene-3,4,9,10-
An electrophotographic photoreceptor comprising a perylene pigment such as tetracarboxydiimide, a binder resin, and acenaphthylene as a sensitizer (JP-A-58-76840), the above perylene pigment, and a charge transport material. An electrophotographic photosensitive member has been proposed which comprises the polyvinylcarbazole-based resin described above and terphenyl as a sensitizer (JP-A-59-119356).

(Problems to be Solved by the Invention) However, sufficient electrophotographic characteristics have not been obtained even with the above-mentioned photoreceptor. In particular, the perylene-based compound used as a charge generation material has no spectral sensitivity on the long wavelength side, so that sufficient sensitivity cannot be obtained when combined with a halogen lamp having large red spectral energy. There was a point.

(Object of the Invention) The present invention has been made in view of the above problems, and by finding a combination of materials sufficiently satisfying the properties required for an electrophotographic photoreceptor, a single-layer type electron having high sensitivity can be obtained. An object is to provide a photographic photoreceptor.

(Means and Actions for Solving Problems) Therefore, in the present invention, the following general formula [I] is used as a charge generating material in the binder resin. (Wherein R ¹ , R ² , R ³ and R ⁴ represent an alkyl group) and a charge transporting material represented by the following general formulas [II] to [V] (In the formula, R ^{5 to} R ²⁰ are the same or different and are a hydrogen atom,
Represents a lower alkyl group, a lower alkoxy group or a halogen atom; Y represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom; n represents an integer of 1 to 3; l, m, o and p represent Indicates an integer of 0 to 2;
R ^9, R ^10, R ¹¹ and R ¹² are assumed not simultaneously hydrogen atoms, wherein R ⁹ is not a hydrogen atom, R ^10, of R ¹¹ and R ¹² l,
at least one of m, o, and p is 2), and at least one compound selected from the group of diamine derivatives represented by
The above object was achieved by forming a photosensitive layer containing 1.25 to 3.75 parts by weight of X-type metal-free phthalocyanine with respect to parts by weight on a conductive substrate to form an electrophotographic photosensitive member.

As a result of earnest studies by the present inventors, the diamine derivatives represented by the general formulas [II] to [V] as the charge transport material have good compatibility with the binder resin, and further, the electric field strength dependence of the drift mobility. We obtained the finding that has a characteristic that is small. Then, the positively chargeable single-layer type electrophotographic photosensitive member obtained by combining the diamine derivative and the perylene compound represented by the general formula [I] as a charge generating material and incorporating them in the binder resin is Excellent electrophotographic characteristics such as characteristics, sensitivity and residual potential. Furthermore, by adding X-type metal-free phthalocyanine as a spectral sensitizer in the range of 1.25 to 3.75 parts by weight with respect to 100 parts by weight of the perylene-based compound, the spectral sensitivity region is expanded to the long wavelength side, and the photosensitivity of higher sensitivity is increased. It turns out that you get a body.

(Preferred Embodiment of the Invention) The perylene-based compound as the charge generating material used in the present invention is represented by the above general formula [I], and R ¹ , R ² , R ³ and R in the formula
Examples of the alkyl group among ⁴ include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl and hexyl groups.

Specifically, N, N'-di (3,5-dimethylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-
Di (3-methyl-5-ethylphenyl) perylene-3,4,
9,10-Tetracarboxydiimide, N, N'-di (3,5-diethylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3,5-dipropylphenyl ) Perylene-3,4,9,10-tetracarboxydiimide, N, N '
-Di (3,5-diisopropylphenyl) perylene-3,4,
9,10-Tetracarboxydiimide, N, N'-di (3-methyl-5-isopropylphenyl) perylene-3,4,9,10
-Tetracarboxydiimide, N, N'-di (3,5-dibutylphenyl) perylene-3,4,9,10-tetracarboxydiimide, N, N'-di (3,5-di-tert-butylphenyl )
Perylene-3,4,9,10-tetracarboxydiimide, N,
N'-di (3,5-dipentylphenyl) perylene-3,4,9,
10-tetracarboxydiimide, N, N'-di (3,5-dihexylphenyl) perylene-3,4,9,10-tetracarboxydiimide and the like are exemplified, but among them, N, N'-di (3 ,Five
-Dimethylphenyl) perylene-3,4,9,10-tetracarboxydiimide is preferred.

As the diamine derivative as the charge transport material used in the present invention, the compounds represented by the above general formulas [II] to [V] are used.

Examples of the lower alkyl group in the above general formulas [II] to [V] include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl and hexyl groups. It Among the above lower alkyl groups, alkyl groups having 1 to 4 carbon atoms are preferable.

Further, examples of the lower alkoxy group include alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, bromopoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy and hexyloxy groups. Among the above lower alkoxy groups, an alkoxy group having 1 to 4 carbon atoms is preferable.

Further, examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms.

The substituents R ^{5 to} R ²⁰ and the substituent Y may be substituted at any position on the phenyl ring or the naphthyl ring.

In the diamine derivative represented by the general formula [II], preferable compounds among the p-phenylenediamine derivatives with n = 1 include, for example, 1,4-bis (N, N-diphenylamino) benzene and -(N, N-diphenylamino) -4- [N- (3-methylphenyl) -N-phenylamino] benzene, 1,4-bis [N- (3-methylphenyl) -N-phenylamino] benzene Other examples include the diamine derivatives described in Japanese Patent Application No. 62-277158, P13 to P20.

In the diamine derivative represented by the general formula [II],
Among the benzidine derivatives of n = 2, preferred compounds include, for example, 4,4′-bis (N, N-diphenylamino)
Diphenyl, 4,4'-bis [N- (3-methylphenyl) -N-phenylamino] diphenyl, 4,4'-bis [N- (3-methoxyphenyl) -N-phenylamino] diphenyl, 4, 4'-bis [N- (3-chlorophenyl) -N-phenylamino] diphenyl, 4- [N-
(2-Methylphenyl) -N-phenylamino] -4 '
-[N- (4-methylphenyl) -N-phenylamino] diphenyl, 4- [N- (2-methylphenyl)-
N-phenylamino] -4 ′-[N- (3-methylphenyl) -N-phenylamino] diphenyl, 3,3′-dimethyl-N, N, N ′, N′-tetrakis-4-methylphenyl ( 1,1'-biphenyl) -4,4'-diamine, 3,3'-
Examples include dimethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-diamine and the like, and Japanese Patent Application No. 62-277158 P21- The diamine derivative described in P28 is exemplified.

In the diamine derivative represented by the general formula [II],
Among the 4,4 ″ -terphenyldiamine derivatives with n = 3,
Preferred compounds include, for example, 4,4 ″ -bis (N, N-
Diphenylamino) -1,1 ′: 4 ′, 1 ″ -terphenyl,
4,4 ″ -bis [N- (3-methylphenyl) -N-phenylamino] -1,1 ′: 4 ′, 1 ″ -terphenyl and the like are exemplified, and in addition, Japanese Patent Application No. 62-277158. The diamine derivative described in P28 to P34 is exemplified.

In the diamine derivative represented by the above general formula [III], among the p-phenylenediamine derivatives with n = 1, preferable compounds include, for example, 1- [N- (3,
5-Dimethylphenyl) -N-phenylamino] -4-
(N, N-diphenylamino) benzene, 1- [N, N-di (3,5-dimethylphenyl) amino] -4- (N, N-diphenylamino) benzene, 1,4-bis [N- ( Examples include 3,5-dimethylphenyl) -N-phenylamino] benzene, and the diamine derivatives described in Japanese Patent Application No. 62-277159, P13 to P21.

In the diamine derivative represented by the general formula [III], among the benzidine derivatives of n = 2, preferred compounds include, for example, 4,4-bis [N- (3,5-dimethylphenyl) -N-phenyl Amino] diphenyl, 4,4-bis [N- (3,5-dimethoxyphenyl) -N-phenylamino] diphenyl, 4,4-bis [N- (3,5-dichlorophenyl) -N-phenylamino] diphenyl , 4,4-
Bis [N- (3,5-dimethylphenyl) -N- (3-methylphenyl) amino] diphenyl, 4- [N- (2,4
-Dimethylphenyl) -N-phenylamino] -4'-
[N- (3,5-dimethylphenyl) -N-phenylamino] diphenyl and the like are exemplified, and in addition, Japanese Patent Application No. 62-277.
The diamine derivatives described in JP-A No. 159 P21 to P29 are exemplified.

In the diamine derivative represented by the above general formula [III], among the 4,4 ″ -terphenyldiamine derivatives with n = 3, preferred compounds include, for example, 4,4 ″ -bis [N- (3,5 -Dimethylphenyl) -N-phenylamino] -1,1 ': 4', 1 "-terphenyl, 4- [N- (3,5
-Dimethylphenyl) -N-phenylamino] -4 "-
(N, N-diphenylamino) -1,1 ': 4', 1 "-terphenyl, 4- [N, N-bis (3,5-dimethylphenyl) amino] -4"-(N, N- Diphenylamino) -1,1 ': 4',
1 ″ -terphenyl and the like are exemplified, and in addition, Japanese Patent Application No. 62-
Illustrative are the diamine derivatives described in JP-A No. 277159, P29 to P36.

In the diamine derivative represented by the general formula [IV], among the p-phenylenediamine derivatives of n = 1,
Preferred compounds include, for example, 1,4-bis [N-
(6-Methylnaphthyl) -N-phenylamino] benzene, 1,4-bis (N-naphthyl-N-phenylamino)
Benzene, 1- (N-naphthyl-N-phenylamino)
Examples include 4- [N- (6-methylnaphthyl) -N-phenylamino] benzene and the like, and Japanese Patent Application No. 62-277.
The diamine derivatives described in JP 161 P13-P19 are exemplified.

In the diamine derivative represented by the general formula [IV],
Among the benzidine derivatives of n = 2, preferred compounds include, for example, 4,4′-bis (N-naphthyl-N-phenylamino) diphenyl and 4,4′-bis [N- (6-methylnaphthyl)- N-phenylamino] diphenyl, 4,
4'-bis [N- (6-methoxynaphthyl) -N-phenylamino] diphenyl, 4,4'-bis [N- (6-chloronaphthyl) -N-phenylamino] diphenyl, 4,
4'-bis [N- (6-methylnaphthyl) -N- (3-
Methylphenyl) amino] diphenyl, 4- [N- (6
-Methylnaphthyl) -N-phenylamino] -4'-
[N- (6-methylnaphthyl) -N- (3-methylphenyl) amino] diphenyl, 4- [N- (4-methylnaphthyl) -N-phenylamino] -4 '-[N- (6-
Methylnaphthyl) -N-phenylamino] diphenyl and the like, and other examples include Japanese Patent Application No. 62-277161, P19 to P2.
The diamine derivative described in 5 is exemplified.

In the diamine derivative represented by the general formula [IV],
Among the 4,4 ″ -terphenyldiamine derivatives with n = 3,
Preferred compounds include, for example, 4,4 "-bis (N-
Naphthyl-N-phenylamino) -1,1 ': 4', 1 "-terphenyl, 4,4" -bis [N- (6-methylnaphthyl) -N-phenylamino] -1,1 ': 4 Examples include ′, 1 ″ -terphenyl, and the diamine derivatives described in Japanese Patent Application No. 62-277161, P25 to P30.

In the diamine derivative represented by the general formula [V], among the p-phenylenediamine derivatives with n = 1,
Preferred compounds include, for example, 1,4-bis (N, N-dinaphthylamino) benzene, 1- (N, N-dinaphthylamino) -4- [N- (6-methylnaphthyl) -N-naphthyl Amino] benzene, 1,4-bis [N- (6-methylnaphthyl) -N-naphthylamino] benzene and the like are exemplified, and in addition, diamine derivatives described in Japanese Patent Application No. 62-277162, P13 to P22 are exemplified. To be done.

In the diamine derivative represented by the general formula [V],
Among the benzidine derivatives of n = 2, preferred compounds include, for example, 4,4′-bis [N, N-di (6-methylnaphthyl) amino] diphenyl and 4,4′-bis [N- (6-
Methylnaphthyl) -N-naphthylamino] diphenyl,
4,4'-bis [N- (6-methoxynaphthyl) -N-naphthylamino] diphenyl, 4,4'-bis [N- (6-
Chloronaphthyl) -N-naphthylamino] diphenyl,
4- [N, N-di (6-methylnaphthyl) amino] -4 '
-[N- (6-methylnaphthyl) -N-naphthylamino] diphenyl, 4- [N- (4-methylnaphthyl) amino-N-naphthylamino] -4 '-[N- (6-methylnaphthyl)- Examples thereof include N-naphthylamino] diphenyl, and the diamine derivatives described in Japanese Patent Application No. 62-277162, P22 to P30.

In the diamine derivative represented by the general formula [V],
Among the 4,4 ″ -terphenyldiamine derivatives with n = 3,
Preferred compounds include, for example, 4,4 ″ -bis (N, N-
Dinaphthylamino) -1,1 ′: 4 ′, 1 ″ -terphenyl,
4,4 ″ -bis [N- (6-methylnaphthyl) -N-naphthylamino] -1,1 ′: 4 ′, 1 ″ -terphenyl and the like are exemplified, and in addition, Japanese Patent Application No. 62-277162. Examples are the diamine derivatives described in P30 to P38.

The diamine derivatives represented by the general formulas [II] to [V] are used alone or in combination of two or more. The diamine derivative has a good molecular symmetry, does not cause an isomerization reaction by light irradiation, is excellent in light stability, has a large drift mobility, and is dependent on the electric field strength related to the drift mobility. The nature is small.

By combining the diamine derivative having the above-mentioned properties with the perylene-based compound, even a photoreceptor having a single-layer type photosensitive layer can be obtained with high sensitivity and a small residual potential.

As the binder resin used in the present invention, various ones, for example, a styrene polymer, an acrylic polymer, a styrene-acrylic polymer, polyethylene, an ethylene-vinyl acetate copolymer, a chlorinated polyethylene, a polypropylene. ,
Olefin-based polymers such as ionomer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyester,
Alkyd resin, polyamide, polyurethane, epoxy resin, polycarbonate, polyarylate, polysulfone, diallyl phthalate, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, and photocurable resin such as epoxy acrylate. Polymers can be used, but the sensitivity of the photoconductor is improved, the abrasion resistance and repeatability of the photoconductor are excellent, and the selection range of the solvent that dissolves the binder resin is wide (4,4 ').
-Cyclohexylidenediphenyl) carbonate is preferred. When poly (4,4′-cyclohexylidenediphenyl) carbonate is used, tetrahydrofuran is different from bisphenol A type polycarbonate, which has conventionally been able to use only chlorine-based solvents such as dichloromethane and monochlorobenzene from the viewpoint of solution stability. Since a solvent such as methyl ethyl ketone can also be used, it is preferable in terms of safety and hygiene and is easy to handle. Among the above poly (4,4′-cyclohexylidenediphenyl) carbonates, the molecular weight is 15,000 to 25,000 and the glass transition point is 58 ° C.
Something is preferable.

The use ratio of the perylene compound, the diamine derivative and the binder resin is not particularly limited and can be appropriately selected according to the desired characteristics of the electrophotographic photoreceptor, etc., but the binder resin is 100 parts by weight. On the other hand, the perylene compound is 2 to 20 parts by weight, preferably 3 to 15 parts by weight, the diamine derivative 40 to
200 parts by weight, preferably 50-100 parts by weight are used. When the amount of the perylene compound and the diamine derivative used is less than the above-mentioned amount, not only the sensitivity of the photoconductor is insufficient but also the residual potential becomes large. On the other hand, if it exceeds the above range, the abrasion resistance of the photoconductor becomes insufficient.

Usually, when the above-mentioned perylene-based compound is used in a large amount, the positive charging property becomes insufficient, and when it is a small amount, the sensitivity and the like decrease, but in the electrophotographic photoreceptor of the present invention, the specific perylene-based compound and diamine are used. Since the derivative and the X-type metal-free phthalocyanine are combined, an electrophotographic photoreceptor having high sensitivity and surface potential, a small residual potential, and excellent positive charging property is obtained even if the amount of the perylene-based compound is small. be able to.

The X-type metal-free phthalocyanine used in the present invention has Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.1 °, 16.
Those having strong analytical peaks at 7 °, 17.3 ° and 22.3 ° are preferable. By adding 1.25 to 3.75 parts by weight of the X-type metal-free phthalocyanine to 100 parts by weight of the perylene-based compound, the spectral sensitivity region is expanded to the long wavelength side, and the sensitivity of the photoconductor becomes higher. However, the addition of 1.25 parts by weight or less of X-type metal-free phthalocyanine to 100 parts by weight of the perylene compound does not produce the sensitizing effect on the long wavelength side. Further, if 3.75 parts by weight or more of X-type metal-free phthalocyanine is added to 100 parts by weight of the perylene-based compound, the spectral sensitivity on the long wavelength side becomes high on the contrary, and the reproducibility of the red original becomes poor.

Further, when an antioxidant is used in combination, it is possible to preferably prevent deterioration of a charge transport material having a structure susceptible to oxidation due to oxidation.

As the above-mentioned antioxidant, 2,6-di-tert-butyl-p
-Cresol, triethylene glycol-bis [3-
(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], penta Erythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-] Hydroxyphenyl) propionate], 2,2-thiobis (4-
Methyl-6-tert-butylphenol), N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,
Examples thereof include phenolic antioxidants such as 4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, and among them, 2,6-di-tert-butyl-p -Cresol is preferred.

The photoreceptor of the present invention can be obtained by preparing a coating liquid containing the above-mentioned components, coating the coating liquid on a conductive substrate, and drying.

The conductive substrate may be in the form of a sheet or a drum having conductivity, various materials having conductivity,
For example, aluminum whose surface is anodized or untreated, aluminum alloy, copper, tin, platinum, gold,
A simple metal such as silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, or brass, or a plastic material on which a layer of the above metal, indium oxide, tin oxide or the like is formed by a method such as vapor deposition. Examples thereof include glass and the like. Among them, those anodized by the sulfuric acid alumite method and sealed with nickel acetate are preferable.

The conductive substrate may be subjected to a surface treatment with a surface treatment agent such as a silane coupling agent or a titanium coupling agent, if necessary, to enhance the adhesion to the photosensitive layer.

In the preparation of the coating solution, an appropriate organic solvent is used depending on the type of binder resin used, and the organic solvent includes, for example, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, Aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride and chlorobenzene, tetrahydrofuran, ethylene glycol dimethyl ether,
Ethers such as ethylene glycol diethyl ether,
Various solvents such as acetone, methyl ethyl ketone, cyclohexanone, and other ketones, ethyl acetate, methyl acetate, and other esters are exemplified, and one solvent or a mixture of two or more solvents is used. In addition, in order to improve dispersibility, coatability, etc. when preparing each of the above-mentioned coating solutions, a surfactant, a leveling agent such as silicone oil, or a conventionally known sensitization such as terphenyl, halonaphthoquinones, and acenaphthylene is used. Various additives such as agents may be used in combination. Polydimethylsiloxane is preferable as the silicone oil.

Each of the above-mentioned coating liquids and the like can be prepared by using a conventionally used mixing / dispersing method, for example, a paint shaker, a mixer, a ball mill, a sand mill, an attritor, an ultrasonic disperser, or the like, and the obtained dispersion liquid or the like is coated. On the occasion,
Conventional coating methods such as dip coating, spray coating, spin coating,
Roller coating, blade coating, curtain coating, bar coating and the like are used.

The single-layer type electrophotographic photoreceptor of the present invention may have an appropriate thickness, but is 15 to 30 μm, and particularly 18 to 27 μm.
Those having a thickness of are preferable.

(Example) Hereinafter, the present invention will be described in more detail based on Examples.

Example 1 100 parts by weight of poly (4,4′-cyclohexylidenediphenyl) carbonate (trade name Polycarbonate Z, manufactured by Mitsubishi Gas Chemical Co., Inc.), N, N′-di (3,5-dimethylphenyl)
Perylene-3,4,9,10-tetracarboxydiimide 8 parts by weight, X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) 0.2 parts by weight, 3,3'-diethyl-N, N, N ', N'- Tetrakis-4-methylphenyl (1,1'-biphenyl)-
Using 4 parts of 4,4'-diamine, 0.01 part by weight of silicon oil (manufactured by Shin-Etsu Chemical Co., Ltd.) and a predetermined amount of tetrahydrofuran, a dispersion liquid for a single layer type photosensitive layer was prepared with an ultrasonic disperser and was about 8 μm. Was coated on an alumite-treated aluminum base tube and heat-treated at about 100 ° C. to prepare an electrophotographic photoreceptor having a photosensitive layer with a thickness of about 23 μm.

Example 2 3,3'-Diethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-of Example 1
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 100 parts by weight of 4,4′-bis [N- (3,5-dimethylphenyl) -N-phenylamino] biphenyl was used instead of the diamine. .

Example 3 3,3'-Diethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-of Example 1
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 100 parts by weight of 4,4′-bis [N- (6-methylnaphthyl) -N-phenylamino] biphenyl was used instead of the diamine.

Example 4 3,3'-Diethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-of Example 1
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 100 parts by weight of 4,4′-bis [N- (6-methylnaphthyl) -N-naphthylamino] biphenyl was used instead of the diamine.

Comparative Example 1 3,3'-diethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-of Example 1
Using 100 parts by weight of N-ethyl-3-carbazolylaldehyde N, N-diphenylhydrazone instead of diamine,
An electrophotographic photosensitive member was produced in the same manner as in Example 1 above.

Comparative Example 2 Instead of the X-type metal-free phthalocyanine of Example 1,
Using 0.2 parts by weight of β-type metal-free phthalocyanine,
An electrophotographic photosensitive member was produced in the same manner as in Example 1 above.

Comparative Example 3 In Example 1, the X-type metal-free phthalocyanine was added.
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 0.05 part by weight was used.

Comparative Example 4 In Example 1, the X-type metal-free phthalocyanine was added.
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that 0.4 part by weight was used.

Evaluation Test (a) Charging Characteristics, Photosensitivity, etc. In order to examine the charging characteristics and photosensitivity of the electrophotographic photoreceptors obtained in the above Examples and Comparative Examples, a drum sensitivity tester (Gentec Cynthia manufactured by Gentec) was used. 30M)
Was used to positively charge each photoconductor, and their charging potential (surface potential) SP (V) was measured. In addition, the time required until the charging potential was reduced to 1/2 by exposure with a halogen lamp was calculated, and the half-exposure amount E1 / 2 (μJ / cm ² ) was calculated. After exposure, the surface potential after 0.15 seconds has passed is the residual potential RP.
(V).

(B) Red reproducibility After copying a gray original document having the same brightness as red and measuring the reflection density of the obtained copy with a reflection densitometer, The red reproducibility was examined by calculating Red reproduction is 70
% Or less is ×, and 70% to 100% is △, 100
% Or more was evaluated as ◯.

The results of charging characteristics, photosensitive characteristics and red color reproducibility of the electrophotographic photosensitive members obtained in the above Examples and Comparative Examples are shown in the table.

As is clear from the table, the electrophotographic photosensitive member of the present invention has a small half-exposure amount, good sensitivity, high surface potential,
The residual potential is small.

On the other hand, the photoconductors of Comparative Examples 1 and 2 have low sensitivity,
The residual potential is also large.

Further, the photoconductor of Comparative Example 3 in which less than 1.25 parts by weight of X-type metal-free phthalocyanine was added to the perylene compound had lower sensitivity and larger residual potential than the photoconductor of Example 1. On the other hand, the photoconductor of Comparative Example 4 containing more than 3.75 parts by weight has poor red reproducibility.

(Effects of the Invention) As described above, according to the present invention, a high-sensitivity electrophotographic photoreceptor can be obtained by combining a specific perylene compound, a diamine derivative and an X-type metal-free phthalocyanine.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keisuke Sumita 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka Prefecture Mita Industry Co., Ltd. No. 28 Mita Kogyo Co., Ltd. Examiner Mitsuo Suma (56) Reference JP 62-103650 (JP, A) JP 63-188152 (JP, A) JP Kohei 5-20742 (JP, B2) JP Kohei 5-20743 (JP, B2) Japanese Kohei 5-20744 (JP, B2) Japanese Kohei 5-20745 (JP, B2)

Claims (5)

[Claims] 1. A charge generating material in a binder resin, represented by the following general formula [I]: (Wherein R ¹ , R ² , R ³ and R ⁴ represent an alkyl group) and a charge transporting material represented by the following general formulas [II] to [V] (In the formula, R ^{5 to} R ²⁰ are the same or different and are a hydrogen atom,
Represents a lower alkyl group, a lower alkoxy group or a halogen atom; Y represents a hydrogen atom, a lower alkyl group, a lower alkoxy group or a halogen atom; n represents an integer of 1 to 3; l, m, o and p represent Indicates an integer of 0 to 2;
R ^9, R ^10, R ¹¹ and R ¹² are assumed not simultaneously hydrogen atoms, wherein R ⁹ is not a hydrogen atom, R ^10, of R ¹¹ and R ¹² l,
m, o and p are such that at least one is 2.) at least one compound selected from the group of diamine derivatives represented by: and 1.25 to 3.75 parts by weight per 100 parts by weight of the above perylene compound. An electrophotographic photosensitive member, wherein a photosensitive layer containing a part of X-type metal-free phthalocyanine is formed on a conductive substrate. 2. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains an antioxidant. 3. A perylene-based compound is N, N'-bis (3,5-
The electrophotographic photosensitive member according to claim 1, which is dimethylphenyl) perylene-3,4,9,10-tetracarboxydiimide. 4. The electrophotographic photosensitive member according to claim 1, wherein R ^{5 to} R ²⁰ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom. . 5. The electrophotographic photosensitive member according to claim 1, wherein Y is an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.