JPH06100836B2 - 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 laminated photoreceptor has various functions separated by the charge generation layer and the charge transport layer, it has an advantage that it has high sensitivity and a wide selection range of photosensitive materials, unlike the single-layer photoreceptor.

By the way, since many charge transport materials are of positive charge transport type and have a durable surface, a charge generation layer is provided on a conductive substrate, and a charge transport layer is further provided on the charge generation layer. It is common to have a body structure. However, in such a negative charging laminated photoreceptor, ozone is generated in the atmosphere at the time of negative charging to cause deterioration of the photoreceptor and contamination of the copying environment, and at the time of the phenomenon, a positive charging toner which is difficult to manufacture is required. There is a problem such as

On the other hand, the above-mentioned single-layer type photoconductor can be positively charged, and a negatively chargeable toner can be used as a toner that causes an electrostatic latent image on the photoconductor. 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 view of the above problems, an electrophotographic photosensitive member (Japanese Unexamined Patent Publication No. 63-223651) in which dibromoanthanthrone and a diamine derivative are combined has been proposed.

(Problems to be Solved by the Invention) However, with the above-mentioned photoreceptor, sufficient electrophotographic characteristics cannot be obtained yet, and the electrophotographic characteristics such as charging characteristics, sensitivity, and residual potential are excellent, and the copying process is not performed again. Also in this case, development of a photoconductor having more excellent stability of surface potential is desired.

Therefore, it is an object of the present invention to provide a positively chargeable single-layer type electrophotographic photosensitive member which is excellent not only in electrophotographic characteristics such as charging characteristics, sensitivity and residual potential but also in repeated stability.

(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 represents a halogen atom or an alkoxy group, and n represents an integer of 0 to 4), and a general formula [II] below as a charge transport material. And a hydrazone-based compound represented by the following general formula [III], a fluorene-based compound represented by the following general formula [IV], and m- represented by the following general formula [V]. Phenylenediamine compounds (In the formula, R ² represents a hydrogen atom or an alkyl group) (In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ represent a hydrogen atom or an alkyl group) (In the formula, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ represent an alkyl group, an alkoxy group, or a halogen atom. All the substituents may be the same or different from each other.) A photosensitive layer containing at least one selected from the group consisting of The above object was achieved by constructing the body.

As a result of diligent studies by the present inventors, a cibenzopyrene-based compound represented by the general formula [I] as a charge generating material and a diamine derivative represented by the general formula [II] as a charge transport material in a binder resin In the photoreceptor having the single-layer type photosensitive layer of the system contained in, the hydrazone compound represented by the general formula [III], the fluorene compound represented by the general formula [IV], and the general formula [V ] It was found that a stable surface potential can be maintained even when the copying process is repeated by selecting and mixing at least one kind from the group consisting of m-phenylenediamine compounds represented by

(Preferred Embodiment of the Invention) The dibenzopyrene-based compound as the charge generating material used in the present invention is represented by the above general formula [I], and the halogen atom of R ^{1 in} the formula is fluorine, bromine or iodine. Is exemplified. Of the above halogen atoms, chlorine or bromine is preferable.

As the alkoxy group, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy,
Examples thereof include alkoxy groups having 1 to 6 carbon atoms such as tert-butoxy, pentyloxy and hexyloxy groups.

Specifically, dibenzo [def, mno] chrysene-6,12-dione, 2,8-dichloro-dibenzo [def, mno] chrysene-
6,12-dione, 4,10-dichloro-dibenzo [def, mno]
Chrysene-6,12-dione, 2,4,8,10-tetrachloro-dibenzo [def, mno] chrysene-6,12-dione, 2,8-dibromo-dibenzo [def, mno] chrysene-6,12 -Zeon,
4,10-dibromo-dibenzo [def, mno] chrysene-6,12
-Dione, 2,4,8,10-tetrabromo-dibenzo (def, mn
o] chrysene-6,12-dione, 2,8-dichloro-4,10-dibromo-dibenzo [def, mno] chrysene-6,12-dione, 2,8-dimethoxy-dibenzo [def, mno] chrysene-
6,12-dione, 4,10-dimethoxy-dibenzo (def, mn
o) chrysene-6,12-dione, 2,8-diethoxy-dibenzo [def, mno] chrysene-6,12-dione, 4,10-diethoxy-dibenzo [def, mno] chrysene-6,12-dione,
2,4,8,10-tetramethoxy-dibenzo [def, mno] chrysene-6,12-dione, 2,4,8,10-tetraethoxy-dibenzo [def, mno] chrysene-6,12-dione, 2,8-dimethoxy-4,10-diethoxy-dibenzo [def, mno] chrysene-6,12-dione, 4,10-dipropoxy-dibenzo [de
f, mno] chrysene-6,12-dione, 4,10-diisopropoxy-dibenzo [def, mno] chrysene-6,12-dione,
4,10-dibutoxy-dibenzo [def, mno] chrysene-6,1
2-dione, 4,10-diisobutoxy-dibenzo (def, mn
o] chrysene-6,12-dione, 4,10-di-tert-butoxy-dibenzo [def, mno] chrysene-6,12-dione, 4,1
0-dipentyloxy-dibenzo [def, mno] chrysene-
6,12-dione, 4,10-dihexyloxy-dibenzo (de
Examples include f, mno] chrysene-6,12-dione and the like. Among the above dibenzopyrene compounds, 4,10-dibromo-dibenzo [def, mno] chrysene-6,12-dione is particularly preferable.

In addition, the halides and alkoxylates of the above-mentioned dibenzopyrene compounds are difficult to isolate and purify, and the positions of the above substituents may not be specified in some cases.

The dibenzopyrene compounds represented by the above general formula [I] are used alone or in combination of two or more.

Examples of the diamine derivative as the charge transport material used in the present invention include 3,3′-dimethyl-N, N, N ′, N′-tetrakis-4-methylphenyl (represented by the general formula [II]. 1,1'-biphenyl) -4,4'-diamine is used.

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 dibenzopyrene-based 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 dibenzopyrene compound is used in an amount of 2 to 20 parts by weight, preferably 3 to 15 parts by weight, a diamine derivative of 40 to 200 parts by weight, and preferably 50 to 100 parts by weight. If the amount of the dibenzopyrene-based compound and the diamine derivative used is less than the above 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.

Furthermore, in the single-layer type photoreceptor of the system containing the dibenzopyrene-based compound and the diamine derivative in the binder resin, the hydrazone-based compound represented by the general formula [III], represented by the general formula [IV] Selected from the fluorene-based compound and the m-phenylenediamine-based compound represented by the general formula [V], and mixed with the fluorene-based compound represented by the general formula [IV]. , The general formula [II
I] or a combination of hydrazone compounds,
Alternatively, by selecting and mixing two kinds in which the m-phenylenediamine compound represented by the general formula [V] is combined, a decrease in surface potential due to repetition of the copying process is prevented and a stable surface potential is maintained. be able to.

The alkyl group in the above general formulas [III], [IV] and [V] is an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl and hexyl groups. Is exemplified.
Examples of the alkoxy group in the general formula [V] include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy groups and the like. Further, the halogen atom in the general formula [V] is fluorine,
Included are chlorine, bromine and iodine atoms.

Examples of the hydrazone compound represented by the general formula [III] include 3-carbazolylaldehyde N, N-diphenylhydrazone, N-methyl-3-carbazolylaldehyde N,
N-diphenylhydrazone, N-ethyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-propyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-isopropyl-3-carbazolylaldehyde N , N-diphenylhydrazone, N-butyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N
-Isobutyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-tert-butyl-3-carbazolylaldehyde N, N-diphenylhydrazone, N-pentyl-3-carbazolylaldehyde N, N-diphenyl Hydrazone, N-hexyl-3-carbazolyl aldehyde N,
Examples of N-diphenylhydrazone and the like, among them,
N-ethyl-3-carbazolyl aldehyde N, N-diphenylhydrazone is preferred.

Examples of the fluorene compound represented by the general formula [IV] include 9-carbazolyliminofluorene, 9- (3-methylcarbazolylimino) fluorene, 9- (3,6-dimethylcarbazolylimino). Fluorene, 9- (3,6-
Diethylcarbazolylimino) fluorene, 9- (3-
Ethyl-6-methylcarbazolylimino) fluorene,
9- (3,6-dipropylcarbazolylimino) fluorene, 9- (3,6-diisopropylcarbazolylimino)
Fluorene, 9- (3,6-dibutylcarbazolylimino) fluorene, 9- (3,6-diisobutylcarbazolylimino) fluorene, 9- (3,6-di-tert-butylcarbazolylimino) fluorene , 9- (3,6-dipentylcarbazolylimino) fluorene, 9- (3,6-dihexylcarbazolylimino) fluorene, 9- (3,6
-Dimethylcarbazolylimino) -3-methylfluorene, 9- (3,6-dimethylcarbazolylimino) -3,6-
Examples include dimethylfluorene, 9- (3,6-dimethylcarbazolylimino) -3,6-diethylfluorene, and 9- (3,6-dimethylcarbazolylimino) -3-ethylfluorene, but among them, 9-carbazolyliminofluorene is preferred.

Examples of the m-phenylenediamine compound represented by the general formula [V] include N, N, N ', N'-tetraphenyl-1,3-
Phenylenediamine, N, N, N ', N'-tetrakis (3-
Tolyl) -1,3-phenylenediamine, N, N, N ', N'-tetraphenyl-3,5-tolylenediamine, N, N, N', N'-
Tetrakis (3-tolyl) -3,5-tolylenediamine,
N, N, N ', N'-tetrakis (4-tolyl) -1,3-phenylenediamine, N, N, N', N'-tetrakis (4-tolyl) -3,5-tolylenediamine, N , N, N ', N'-Tetrakis (3-ethylphenyl) -1,3-phenylenediamine, N, N, N', N'-Tetrakis (4-propylphenyl) -1,3-phenylenediamine, N , N, N ′, N′-tetraphenyl-5-methoxy-1,3-phenylenediamine,
N, N-bis (3-tolyl) -N ', N'-diphenyl-1,3
-Phenylenediamine, N, N'-bis (4-tolyl)-
N, N'-diphenyl-1,3-phenylenediamine, N, N '
-Bis (4-tolyl) -N, N'-bis (3-tolyl)-
1,3-phenylenediamine, N, N'-bis (4-tolyl)
-N, N'-bis (3-tolyl) -3,5-tolylenediamine, N, N'-bis (4-ethylphenyl) -N, N'-bis (3-ethylphenyl) -1,3 -Phenylenediamine,
N, N'-bis (4-ethylphenyl) -N, N'-bis (3
-Ethylphenyl) -3,5-tolylenediamine, N, N,
N ', N'-tetrakis (2,4,6-trimethylphenyl)-
1,3-phenylenediamine, N, N, N ', N'-tetrakis (2,4,6-trimethylphenyl) -3,5-tolylenediamine, N, N, N', N'-tetrakis (3 , 5-Dimethyl) -1,3
-Phenylenediamine, N, N, N ', N'-tetrakis (3,5
-Dimethyl) -3,5-tolylenediamine, N, N, N ', N'-
Tetrakis (3,5-diethyl) -1,3-phenylenediamine, N, N, N ', N'-tetrakis (3,5-dimethyl) -3,5
-Tolylenediamine, N, N, N ', N'-tetrakis (3-
Chlorophenyl) -1,3-phenylenediamine, N, N,
N ', N'-tetrakis (3-bromophenyl) -1,3-phenylenediamine, N, N, N', N'-tetrakis (3-iodophenyl) -1,3-phenylenediamine, N, N, N ′,
N'-tetrakis (3-fluorophenyl) -1,3-phenylenediamine and the like are exemplified, but among them, the interaction between molecules becomes small due to poor symmetry of molecules, and conversely with resin. Since it has a characteristic that it is extremely difficult to crystallize because it has a large interaction and can be sufficiently dissolved in the resin, R ⁷ , R ⁸ , R ¹⁰ and R ¹¹ in the above general formula [V] are meta-positioned with respect to the nitrogen atom. A compound that is used as a substituting group for
A compound in which R ⁷ and R ¹¹ are substituted at the para position with respect to the nitrogen atom and R ⁸ and R ¹⁰ are substituted at the meta position with respect to the nitrogen atom is preferable.
Specifically, N, N, N ′, N′-tetrakis (3-tolyl)
-1,3-phenylenediamine and N, N'-bis (4-tolyl) -N, N'-bis (3-tolyl) -1,3-phenylenediamine.

Incidentally, each of the above compounds can be used in an appropriate amount depending on the characteristics of the photoreceptor, but when a hydrazone compound is used among the above compounds, a diamine compound and a hydrazone compound as a charge transport material are used. And 95: 5 to 90: 1
It is preferably contained in the photosensitive layer in a weight ratio of 0.

When a fluorene compound is used among the above compounds, it is preferable that the diamine compound and the fluorene compound as the charge transport material are contained in the photosensitive layer in a weight ratio of 90:10 to 80:20. .

In the case of using the m-phenylenediamine compound among the above compounds, the ratio of the diamine compound and the m-phenylenediamine compound as the charge transport material is 75:25.
It is preferable that the photosensitive layer contains it in a weight ratio of from 25 to 75:75, particularly from 70:30 to 50:50.

That is, if the photosensitive layer contains each of the above compounds in a ratio smaller than the above weight ratio, the repeating characteristics are not sufficient, and if the above compounds are contained in a ratio exceeding the above weight ratio, the repeating characteristics become high, but the sensitivity and the like are sufficient. It will not be.

Further, since the dibenzopyrene-based compound has no spectral sensitivity on the long wavelength side, in order to further improve the sensitivity when the single-layer electrophotographic photoreceptor of the present invention is combined with a halogen lamp having a large red spectral energy, It is preferable to use a phthalocyanine compound such as metal-free phthalocyanine or oxotitanyl phthalocyanine, which has spectral sensitivity on the long wavelength side.

As the metal-free phthalocyanine, the Bragg angle (2θ ± 0.2 °) is 7.5 °, 9.1 °, 16.7 °, 17.3 °, 2
The X type having a strong diffraction peak at 2.3 ° is preferable.
When 1.25 to 3.75 parts by weight of the X-type metal-free phthalocyanine is added to 100 parts by weight of the dibenzopyrene-based compound, the spectral sensitivity region shifts to the longer wavelength side, and the sensitivity of the photoreceptor 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 dibenzopyrene compound does not produce the sensitizing effect on the long wavelength side. Further, X-type metal-free phthalocyanine was added to 3.7 parts by weight per 100 parts by weight of the dibenzopyrene-based compound.
On the contrary, if 5 parts by weight or more is added, the spectral sensitivity on the long wavelength side becomes high, and the reproducibility of the red original document deteriorates.

Examples of the oxotitanyl phthalocyanine include:
The following general formula [VI] having various crystal types such as α type, β type, γ type, δ type and ε type (In the formula, X represents a halogen atom, and m represents 0 or an integer of 1 or more). Examples include oxotitanyl phthalocyanine. In particular, the halogen atom in the general formula [VI] is bromine or Chlorine, m is 0,
Bragg angle (2θ ± 0.2 in X-ray diffraction spectrum
°) is 6.9 °, 9.6 °, 15.6 °, 17.6 °, 21.9 °, 23.6
Α-type oxotitanyl phthalocyanine which shows strong diffraction peaks at °, 24.7 ° and 28.0 ° and has the largest diffraction peak at 6.9 ° among the Bragg angles is preferable.

Since the dibenzopyrene-based compound has no spectral sensitivity on the long wavelength side, the oxotitanyl phthalocyanine is added in an amount of 0.62 to 1.8 per 100 parts by weight of the dibenzopyrene-based compound.
By adding 8 parts by weight, the spectral sensitivity region shifts to the long wavelength side, and the sensitivity of the photoconductor becomes higher when combined with a halogen lamp having a large red spectral energy. However, the sensitizing effect on the long wavelength side does not occur only by adding 0.62 parts by weight or less of oxotitanyl phthalocyanine to 100 parts by weight of the dibenzopyrene-based compound. When 1.88 parts by weight or more of oxotitanyl phthalocyanine is added to 100 parts by weight of the dibenzopyrene-based compound, the spectral sensitivity on the long wavelength side is increased, and the reproducibility of the red original document is deteriorated.

In addition, when an antioxidant is used in combination, it is possible to preferably prevent deterioration of a charge transporting material or the like having a structure that is affected by oxidation and is inexpensive, 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 photoconductor of the present invention can be obtained by preparing a coating solution containing each of the above-mentioned components, coating the coating solution 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, but among them, aluminum subjected to anodic oxidation by the sulfuric acid alumite method and sealed with nickel acetate is preferable.

In addition, 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 adjusting the coating solution, an appropriate organic solvent is used according to the type of the binder resin used, and examples of the organic solvent include alcohols such as methanol, ethanol, propanol, isopropanol and 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 Various solvents such as ethers such as ethylene glycol diethyl ether, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate are illustrated, and one solvent or a mixture of two or more solvents is used. Further, when adjusting each of the above-mentioned coating solutions, in order to improve dispersibility, coatability, etc., silicone oil such as polydimethylsiloxane, a leveling agent such as a surfactant, or terphenyl, halonaphthoquinones, acenaphthylene, etc. Various additives such as conventionally known sensitizers may be used in combination.

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 photosensitive layer of the electrophotographic photosensitive member 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) Below, this invention is demonstrated in detail based on an Example.

Example 1 100 parts by weight of poly- (4,4′-cyclohexylidenediphenyl) carbonate (manufactured by Mitsubishi Gas Chemical Co., Inc., trade name Polycarbonate Z), 4,10-dibromo-dibenzo [def, mno]
Chrysene-6,12-dione 8 parts by weight, X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc.) 0.2 parts by weight, 3,3'-
Dimethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -4,4'-diamine 95 parts by weight, N-ethyl-3-carbazolylaldehyde N, N Mix 5 parts by weight of diphenylhydrazone, 5 parts by weight of antioxidant (Kawaguchi Chemical Co., Ltd., trade name Antage BHT), 0.01 parts by weight of polydimethylsiloxane (Shin-Etsu Chemical Co., Ltd.) and a predetermined amount of tetrahydrofuran with an ultrasonic disperser. An electrophotographic photosensitive member is prepared by dispersing and preparing a dispersion liquid for a single-layer type photosensitive layer, applying it on an alumite-treated aluminum base tube to form a photosensitive layer having a thickness of about 23 μm, and heat treating at about 100 ° C. It was created.

Example 2 Further, a single-layer type electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that 10 parts by weight of 9-carbazolyliminofluorene was added.

Example 3 3,3'-Dimethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -used in Example 1
Using 30 parts by weight instead of 95 parts by weight of 4,4'-diamine, N-
Ethyl-3-carbazolyl aldehyde N, N-diphenylhydrazone, except that 70 parts by weight of N, N, N ', N'-tetrakis (3-tolyl) -1,3-phenylenediamine are used instead of 5 parts by weight. In the same manner as in Example 1, a single-layer type electrophotographic photoreceptor was prepared.

Example 4 Instead of N, N, N ', N'-tetrakis (3-tolyl) -1,3-phenylenediamine used in Example 3, N, N'-bis (4-tolyl) -N, N A single-layer type electrophotographic photoreceptor was prepared in the same manner as in Example 3 except that ′ -bis (3-tolyl) -1,3-phenylenediamine was used.

Example 5 A single-layer type electrophotographic photosensitive member was prepared in the same manner as in Example 3 except that 10 parts by weight of 9-carbazolyliminofluorene was added.

Example 6 A single-layer type electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that 0.1 part by weight of α-type oxotitanyl phthalocyanine was used in place of 0.2 part by weight of the X-type metal-free phthalocyanine of Example 1. .

Comparative Example 1 3,3′-Dimethyl-N, N, N ′, N′-tetrakis-4 without adding N-ethyl-3-carbazolylaldehyde N, N-diphenylhydrazone used in Example 1 -Methylphenyl (1,1'-biphenyl) -4,4'-diamine A single-layer type electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 100 parts by weight was used instead of 95 parts by weight. did.

Comparative Example 2 3,3'-Dimethyl-N, N, N ', N'-tetrakis-4-methylphenyl (1,1'-biphenyl) -used in Example 1
In the same manner as in Example 1 except that 4,4'-diamine was not added and 100 parts by weight was used instead of 5 parts by weight of N-ethyl-3-carbazolylaldehyde N, N-diphenylhydrazone. A layer type electrophotographic photoreceptor was prepared.

Then, in order to examine the charging characteristics and the photosensitive characteristics of the electrophotographic photoreceptors obtained in the above-mentioned Examples and Comparative Examples, an electrostatic copying test apparatus (Gentec Cynthia 30 manufactured by Gentec Co., Ltd.) was used.
M) was used to positively charge each of the electrophotographic photoconductors.

The surface potential V _SP (V) of each electrophotographic photosensitive member was measured, and the surface potential V _SP (V) was exposed to the surface of the electrophotographic photosensitive member using a tungsten lamp having an illuminance of 10 lux.
_Calculate the time until _SP becomes 1/2, and reduce the half exposure E1 / 2
(ΜJ / cm ² ) was calculated. The surface potential 0.15 seconds after the exposure was taken as the residual potential V _rp (V).

Further, it was also examined whether or not the surface potential was lowered by repeated use 1000 times. By the repeated use of the photoreceptor, the surface potential of the photoreceptor was reduced by 100 V or more was evaluated as ×, and the reduction in the range of 50 to 100 V was evaluated as Δ, and only 50 V or less was evaluated as ○. .

Furthermore, after copying a gray original with the same lightness as red and measuring the reflection density of the obtained copy with a reflection densitometer, The red reproducibility was examined by calculating The red reproducibility of 70% or less was evaluated as x, the range of 70 to 100% was evaluated as Δ, and the 100% or more was evaluated as o.

Table 1 shows the results of the charging characteristics, the photosensitive characteristics, etc. of the electrophotographic photosensitive members obtained in the above Examples and Comparative Examples.

As is clear from Table 1, the electrophotographic photosensitive members of Examples 1 to 6 all have excellent charging characteristics and high sensitivity.
It was found that the residual potential was small and the repeatability and red color reproducibility were good. On the other hand, the electrophotographic photoreceptors of Comparative Examples 1 and 2 are all excellent in red reproducibility, but have insufficient repetitive characteristics, and the electrophotographic photoreceptor of Comparative Example 2 is sensitive. Was low and the residual potential was high.

(Effects of the Invention) As described above, according to the electrophotographic photosensitive member of the present invention, the charging characteristics are excellent, the sensitivity is high, the residual potential is small, and further the repeating characteristics and the red color reproducibility are excellent. Further, since it is a single-layer type photoreceptor, it has not only excellent positive charging property but also a unique effect that it can be easily manufactured with high yield and is inexpensive.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tatsuo Maeda Tatsuo Maeda 1-2-2 Tamatsukuri, Chuo-ku, Osaka-shi, Osaka Mita Industry Co., Ltd. Mitsuo Suma (56) References JP 62-242950 (JP, JP, A) JP-A-63-271461 (JP, A) JP-B 47-28336 (JP, B1)

Claims (4)

[Claims] 1. A charge generating material in a binder resin, represented by the following general formula [I]: (Wherein R ¹ represents a halogen atom or an alkoxy group, and n represents an integer of 0 to 4), and a general formula [II] below as a charge transport material. And a hydrazone-based compound represented by the following general formula [III], a fluorene-based compound represented by the following general formula [IV], and m- represented by the following general formula [V]. An electrophotographic photoreceptor, comprising: forming a photosensitive layer containing at least one selected from the group consisting of phenylenediamine compounds on a conductive substrate. (In the formula, R ² represents a hydrogen atom or an alkyl group) (In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ represent a hydrogen atom or an alkyl group) (In the formula, R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ represent an alkyl group, an alkoxy group, or a halogen atom. And all the substituents may be the same or different from each other). 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains metal-free phthalocyanine or oxotitanyl phthalocyanine. 3. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains an antioxidant. 4. The electrophotographic photosensitive member according to claim 1, wherein the dibenzopyrene compound is 4,10-dibromo-dibenzo [def, mno] chrysene-6,12-dione.