JPH08220789A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE: To improve photosensitivity and light resistance by incorporating a specified bisazo pigment as an electric charge generating agent, a specified phenylenediamine deriv. and a specified triphenylamine deriv. as electric charge transferring agents into a photosensitive layer formed on an electrically conductive substrate. CONSTITUTION: A photosensitive layer formed on an electrically conductive substrate contains a bisazo pigment represented by formula I as an electric charge generating agent, a phenylenediamine deriv. represented by formula II and a triphenylamine deriv. represented by formula III as electric charge transferring agents. In the formula I, each of A<1> and A<2> is a residue of a coupler, R<1> is H, alkyl which may have a substituent, etc., and (a) is 0 or 1. In the formula II, each of R<2> -R<6> is alkyl which may have a substituent, etc., and each of (b)-(f) is an integer of 0-2. In the formula III, each of RA-RC is alkyl which may have a substituent, etc., and each of αto γ is an integer of 0-3. The triphenylamine deriv. promotes the injection of electric charges from the bisazo pigment into the phenylenediamine deriv. at the time of exposure and enhances the efficiency of generation and transfer of electric charges.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in an image forming apparatus such as an electrostatic copying machine, a laser printer and a plain paper facsimile machine.

[0002]

2. Description of the Related Art Organic photoconductors are widely used in the above image forming apparatus. The organic photoreceptor is a single-layer type photoreceptor in which a charge generating agent that generates an electric charge by light irradiation and a charge transporting agent that transports the electric charge generated by the charge generating agent are dispersed in a binder resin, and the above-mentioned charge. There is a laminated-type photoreceptor including a charge transport layer containing a transport agent and a charge generator containing a charge generator.

Such an organic photoconductor is easier to manufacture than an inorganic photoconductor using an inorganic semiconductor material, and has various choices of materials such as the above-mentioned charge generating agent, charge transporting agent and binder resin. There is an advantage that the degree of freedom in functional design is large. Examples of the charge transfer agent used in the organic photoreceptor include carbazole compounds, oxadiazole compounds, pyrazoline compounds, hydrazone compounds,
Various compounds such as stilbene compounds, phenylenediamine compounds, and benzidine compounds are known,
Recently, the following general formula (4):

[0004]

[Chemical 4]

[Wherein Ar ¹ , Ar ² and Ar ³ are the same or different and may have an alkyl group which may have a substituent, an alkoxy group which may have a substituent or a substituent. An aryl group or a halogen atom is shown. ] Various photoconductors have been proposed in which the amine derivative represented by the formula [1] is used alone or in combination with other charge transport agents (for example, JP-A-57-195254 and JP-A-63). No. 2771355, JP-A-3-21
1559, JP-A-3-223764, JP-A-4-190235, JP-A-5-134434, JP-A-5-158248).

However, according to the studies made by the inventors, it has become clear that all the photoconductors disclosed in the above-mentioned prior applications have insufficient photosensitivity and poor light resistance. An object of the present invention is to provide an electrophotographic photoreceptor having excellent photosensitivity and light resistance.

[0007]

In order to solve the above-mentioned problems, the inventors have further studied the structure of the amine derivative represented by the general formula (4) and used it in combination with the above-mentioned amine derivative. A charge generating agent and a charge transporting agent suitable for are also investigated. As a result, as the amine derivative, Ar ^{1 to} Ar ³ in the general formula (4) are all phenyl groups, and the following general formula (3):

[0008]

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[In the formula, R ^A , R ^B and R ^C are the same or different and may have an alkyl group which may have a substituent, an alkoxy group which may have a substituent or a substituent. An aryl group or an alkylamino group which may have a substituent is shown. α, β and γ are the same or different and each represents an integer of 0 to 3. ] The triphenylamine derivative represented by
It has been found that it is suitable as a charge transfer agent because it has a large spread of π-electron conjugated system in the molecule and has an excellent charge (particularly hole) transporting ability.

Further, the above triphenylamine derivative (3)
The charge generating agent to be combined with the above general formula (1):

[0011]

[Chemical 6]

[Wherein A ¹ and A ² represent the same or different coupler residues, R ¹ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent or a substituent A heterocyclic group which may have a group is shown. a is 0
Or an integer of 1 is shown. ] The bisazo pigment represented by is preferable, and further, the triphenylamine derivative (3) is not used alone as a charge transfer agent,
General formula (2), which has an excellent charge transporting property and is not disclosed in any of the above-mentioned prior applications, is also represented by the general formula (2):

[0013]

[Chemical 7]

[In the formula, R ² , R ³ , R ⁴ , R ⁵ and R ⁶
Are the same or different, and may be an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent, or an alkylamino group which may have a substituent. Indicates. b, c, d, e and f are the same or different and each represents an integer of 0 to 2. ] It was found that it is suitable to use in combination with a phenylenediamine derivative represented by the following, and the present invention has been completed.

That is, the electrophotographic photosensitive member of the present invention comprises: a bisazo pigment (1) which is a charge generating agent;
It is characterized in that a photosensitive layer containing a phenylenediamine derivative (2) and a triphenylamine derivative (3) which are charge transport agents is provided. The present inventors presume that the electrophotographic photoreceptor of the present invention has high photosensitivity and excellent light resistance as follows.

That is, the triphenylamine derivative (3) among the above three components is excellent in electrical matching with the bisazo pigment (1) and the phenylenediamine derivative (2). Further, the triphenylamine derivative (3) is
It has a structure similar to the phenylenediamine derivative (2) in which one nitrogen atom is substituted with three phenyl groups, and it can be mixed evenly with the phenylenediamine derivative (2), and more than the phenylenediamine derivative (2). Since it has a small molecular weight, it is almost evenly dispersed between the bisazo pigment (1) and the phenylenediamine derivative (2) in the photosensitive layer.

Therefore, at the time of exposure, the triphenylamine derivative (3) is bisazo pigment (1) which is a charge generating agent.
From the phenylenediamine derivative
It serves to assist the injection of charges (particularly holes) into (2) and improves the efficiency of charge generation by the bisazo pigment (1), and also transfers (transports) charges between phenylenediamine derivatives (2). Also contributes to the improvement of the charge transport efficiency and, as a result, the sensitivity of the photoconductor is improved.

Further, when the charge transport efficiency is improved as described above, the residual potential of the photoconductor is lowered, so that photodegradation of the above-mentioned components, particularly the phenylenediamine derivative (2) is suppressed, and as a result, the light resistance is reduced. improves. Among the phenylenediamine derivatives (2), for example, in the case of an m-phenylenediamine derivative in which two nitrogen atoms are respectively substituted at the 1-position and 3-position of the central benzene ring, the above-mentioned benzene ring is irradiated when the photoconductor is irradiated with light. There is a problem that the electron density of the carbon atom at the 5th position becomes high, and a photochemical reaction is caused from this portion to cause photodegradation. However, in the electrophotographic photoreceptor of the present invention in which the triphenylamine derivative (3) is present in the vicinity of the m-phenylenediamine derivative, the electron density of the carbon atom is increased due to the interaction of the π-electron conjugated system of both derivatives. Since the photodegradation due to the photochemical reaction accompanying it is suppressed, the light resistance of the photoconductor is further improved in combination with the effect of lowering the residual potential.

The present invention will be described below. As described above, the electrophotographic photoreceptor of the present invention is one in which a photosensitive layer containing a bisazo pigment (1), a phenylenediamine derivative (2) and a triphenylamine derivative (3) is provided on a conductive substrate. . The photosensitive layer includes a so-called single-layer type photosensitive layer and a laminated type photosensitive layer, but the present invention is applicable to both.

The bisazo pigment (1) which is a charge generating agent
The above-described interaction between the phenylenediamine derivative (2) and the triphenylamine derivative (3), which are charge transfer agents, is particularly remarkable in the single-layer type photosensitive layer. Of course, it is also possible to adopt it in the photosensitive layer. Single-layer photosensitive layer is bisazo pigment (1)
, A phenylenediamine derivative (2) and a triphenylamine derivative (3) are dissolved or dispersed in a suitable solvent together with a binder resin, and then applied on a conductive substrate by a means such as application and dried. It is formed.

In the laminated type photosensitive layer, a charge generating layer containing a bisazo pigment (1) as a charge generating agent is first formed on a conductive substrate by means such as vapor deposition or coating, and then the charge generating layer is generated. On the layer, phenylenediamine derivative (2) and triphenylamine derivative, which are charge transport agents,
It is formed by applying a coating liquid containing (3) and a binder resin by a means such as coating and drying it to form a charge transport layer. In contrast to the above, a charge transport layer may be formed on the conductive substrate, and the charge generation layer may be formed thereon.

A bisazo pigment as a charge generating agent is shown.
Examples of the coupler residue corresponding to the groups A ¹ and A ² in the general formula (1) include various conventionally known coupler residues. Further, as the alkyl group corresponding to the group R ¹ ,
For example, methyl group, ethyl group, normal propyl (n-
Pr) group, isopropyl (i-Pr) group, normal butyl (n-Bu) group, isobutyl (i-Bu) group, secondary butyl (s-Bu) group, tertiary butyl (t-Bu) group ,
Examples thereof include lower alkyl groups having 1 to 6 carbon atoms such as pentyl group and hexyl group.

Examples of the alkoxy group include methoxy group, ethoxy group, isopropoxy group, butoxy group,
Examples thereof include a tert-butoxy group and a hexyloxy group.
Examples of the aryl group include phenyl group, biphenyl group, naphthyl group, anthryl group, phenanthryl group, o
-Terphenyl group and the like. Further, as the heterocyclic group, for example, thienyl group, pyrrolyl group, pyrrolidinyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, imidazolyl group, 2H-imidazolyl group, pyrazolyl group, triazolyl group, tetrazolyl group, pyranyl group, Examples thereof include a pyridyl group, piperidyl group, piperidino group, 3-morpholinyl group, morpholino group and thiazolyl group. It may also be a heterocyclic group condensed with an aromatic ring.

Alkyl group, alkoxy group, aryl group,
Examples of the substituent which may be substituted on the heterocyclic group include the above-mentioned alkyl group, halogen atom or alkoxy group. Specific compounds of the bisazo pigment (1) include:
For example, the compounds represented by the formulas (1-1) to (1-4) may be mentioned, though not limited thereto.

[0025]

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[0026]

[Chemical 9]

Further, as the alkyl group, alkoxy group and aryl group corresponding to the groups R ^{2 to} R ⁶ in the general formula (2) showing the phenylenediamine derivative as the charge transfer agent, the same groups as described above can be used. can give. Examples of the alkylamino group include a methylamino group, a dimethylamino group,
Ethylamino group, diethylamino group, propylamino group, isopropylamino group, butylamino group, isobutylamino group, t-butylamino group, pentylamino group,
Hexylamino group and the like.

Further, examples of the substituent which may be substituted on these groups include the same groups as described above. Specific examples of the phenylenediamine derivative (2) include, but are not limited to, compounds represented by the formulas (2-1) to (2-20).

[0029]

[Chemical 10]

[0030]

[Chemical 11]

[0031]

[Chemical 12]

[0032]

[Chemical 13]

[0033]

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[0034]

[Chemical 15]

[0035]

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Further, the groups R ^{A to} R ^{C in the} above general formula (3), which represent triphenylamine derivatives as charge transport agents, are given.
Examples of the alkoxy group, aryl group and alkylamino group corresponding to are the same groups as described above. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl (n-Pr, i-Pr) group among the above-exemplified groups. The triphenylamine derivative (3) in which a butyl group or more, that is, an alkyl group having 4 or more carbon atoms is substituted is a liquid at room temperature and cannot be used for a photoreceptor.

Further, examples of the substituent which may be substituted on these groups include the same groups as described above. Specific examples of the triphenylamine derivative (3) include, but are not limited to, compounds represented by the formulas (3-1) to (3-14).

[0038]

[Chemical 17]

[0039]

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[0040]

[Chemical 19]

[0041]

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[0042]

[Chemical 21]

In the present invention, the bisazo pigment (1) can be used alone as the charge generating agent, and the interaction with the phenylenediamine derivative (2) and the triphenylamine derivative (3) described above is not hindered. Within the range, other conventionally known charge generating agents can be used in combination depending on the sensitivity region of the electrophotographic photosensitive member and the like. Other charge generators that can be used in combination with the bisazo pigment (1) include, but are not limited to, powders of inorganic photoconductive materials such as selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, and a-silicon, and azo-based materials. Pigments, bisazo pigments other than those represented by the general formula (1), perylene pigments, anthanthrone pigments, phthalocyanine pigments, indigo pigments, triphenylmethane pigments, slene pigments, toluidine pigments,
One or more of pyrazoline pigments, quinacridone pigments, dithioketopyrrolopyrrole pigments and the like can be mentioned.

Further, in the present invention, only two kinds of the above-mentioned phenylenediamine derivative (2) and triphenylamine derivative (3) can be used as the charge transfer agent, and in addition to the interaction with the above-mentioned bisazo pigment (1). To the extent that it does not hinder
Other conventionally known charge transport agents can also be used in combination. Examples of the other charge transfer agent that may be used in combination with the above both charge transfer agents include various electron transfer agents and hole transfer agents.

Among the charge transfer agents, electron transfer agents include, for example, benzoquinone compounds, naphthoquinone compounds,
Malononitrile, thiopyran-based compounds, tetracyanoethylene, tetracyanoquinodimethane, chloranil, bromoanil, 2,4,7-trinitro-9-dicyanomethylenefluorenone, 2,4,5,7-tetranitroxanthone, 2,4. Electron withdrawing materials such as 8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, and dibromomaleic anhydride, and polymerizing these electron withdrawing materials The ones that have been made are listed.

Examples of the hole transfer agent include diamine compounds other than the phenylenediamine derivative (2), 2,
A diazole compound such as 5-di (4-methylaminophenyl) -1,3,4-oxadiazole, a styryl compound such as 9- (4-diethylaminostyryl) anthracene, a carbazole compound such as polyvinylcarbazole, 1 -Pyrazoline compounds such as phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds, indole compounds, oxazole compounds,
Electron donating materials such as nitrogen-containing cyclic compounds and condensed polycyclic compounds represented by isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, triazole compounds, etc. .

These charge transfer agents can be used alone or in combination of two or more.
The binder resin is not always necessary when using a charge-transporting agent having film-forming properties such as polyvinylcarbazole. Examples of the binder resin include styrene polymers, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, acrylic polymers, styrene-acrylic copolymers, polyethylene, ethylene. -Vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, vinyl chloride-
Vinyl acetate copolymer, polyester, alkyd resin,
Thermoplastic resins such as polyamide, polyurethane, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, silicone resin, epoxy resin, phenol resin, urea resin, melamine resin and other crosslinkable resins. Thermosetting resin, further epoxy-acrylate,
Examples thereof include photocurable resins such as urethane-acrylate. These binder resins can be used alone or in combination of two or more.

In the photosensitive layer, in addition to the above components, for example, a sensitizer, a fluorene compound, an ultraviolet absorber, a plasticizer,
Various additives such as an interfacial lubricant and a leveling agent can also be added. In order to improve the sensitivity of the photoconductor,
For example, a sensitizer such as terphenyl, halonaphthoquinones and acenaphthylene may be used in combination with the charge generating agent. In the multi-layer type photoreceptor, the charge generating agent and the binder resin which form the charge generating layer can be used in various ratios, but the charge generating agent is 5 to 10 relative to 100 parts by weight of the binder resin.
It is preferably used in an amount of 00 parts by weight, particularly 30 to 500 parts by weight.

The content ratio of the charge generating agent is the content ratio of the bisazo pigment (1) when only the bisazo pigment (1) is used as the charge generating agent, and when another charge generating agent is used in combination. Is the total content of each charge generation agent. Further, the charge transporting agent and the binder resin constituting the charge transporting layer can be used in various ratios within a range that does not hinder the transport of charges and a range that does not crystallize, but in the charge generating layer by light irradiation. In order to easily transport the generated charges, it is preferable to use the charge transfer agent in a total amount of 10 to 500 parts by weight, particularly 25 to 200 parts by weight, based on 100 parts by weight of the binder resin.

When only two kinds of the phenylenediamine derivative (2) and the triphenylamine derivative (3) are used as the charge transfer agent, the content ratio of the charge transfer agent is the total content ratio of both. When two other charge transfer agents, namely, the phenylenediamine derivative (2) and the triphenylamine derivative (3), are used in combination with another charge transfer agent, the total content ratio of each charge transfer agent is shown.

The above phenylenediamine derivative (2)
It is preferable that the weight ratio of phenylenediamine derivative (3) to phenylenediamine derivative (2): triphenylamine derivative (3) = 85: 15 to 50:50. When the amount of the triphenylamine derivative (3) is less than the above range, the effect of adding the triphenylamine derivative (3) cannot be sufficiently obtained, and the sensitivity and light resistance of the photoreceptor may be deteriorated. Further, when the amount of the triphenylamine derivative (3) is more than the above range, the molecular weight of the triphenylamine derivative (3) is small, and therefore the melting point is lower than that of the phenylenediamine derivative (2). The transition temperature may decrease, and the durability and mechanical strength of the photoreceptor may decrease.

The above phenylenediamine derivative (2)
Considering the balance between the sensitivity and light resistance of the photoconductor, and the durability and mechanical strength, the ratio of the triphenylamine derivative (3) to the triphenylamine derivative (3) is 80:20 to 7 in the above range.
It is preferably within the range of 0:30. The thickness of the laminated photosensitive layer is preferably such that the charge generation layer is formed to have a thickness of about 0.01 to 5 μm, particularly 0.1 to 3 μm, and the charge transport layer has a thickness of 2 to 100 μm, particularly 5 to 50 μm. It is preferably formed.

In the single-layer type photoreceptor, the binder resin 10
0.1 to 50 parts by weight, particularly 0.5 to 30 parts by weight, and 20 to 50 parts by weight of the charge transporting agent are added to 0 parts by weight.
Suitably 0 parts by weight, especially 30 to 200 parts by weight. Similar to the above, the content ratio of the charge generating agent is the content ratio of only the bisazo pigment (1) when the bisazo pigment (1) is used alone as the charge generating agent, and the bisazo pigment (1) When used in combination with other charge generating agents, the content ratio is the total of these.

The content ratio of the charge transfer agent is also the same as the above, as the charge transfer agent, the phenylenediamine derivative (2)
And when using only two kinds of triphenylamine derivative (3), it is the total content ratio of both, and it is phenylenediamine derivative (2) and triphenylamine derivative.
When the other two charge transfer agents are used in combination with the two charge transfer agents in (3), the total content of the charge transfer agents is shown.

The ratio of the phenylenediamine derivative (2) to the triphenylamine derivative (3) is the same as that described above, and the weight ratio of the phenylenediamine derivative (2): triphenylamine derivative (3) = 85: It is preferably 15 to 50:50, and more preferably 80:20 to 70:30. The thickness of the single layer type photosensitive layer is 5 to
The thickness is preferably 100 μm, particularly 10 to 50 μm.

In the case of a single-layer type photoreceptor, it is between a conductive substrate and a photosensitive layer, and in the case of a laminated type photoreceptor, it is between a conductive substrate and a charge generation layer, and a conductive substrate. A barrier layer may be formed between the charge transport layer and the charge transport layer or between the charge generation layer and the charge transport layer to the extent that the characteristics of the photoreceptor are not impaired. It may be formed.

As the conductive substrate on which the above layers are formed, various conductive materials can be used.
For example, metals such as iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, and plastic materials obtained by vapor deposition or lamination of the above metals, iodine, Examples thereof include glass coated with aluminum oxide, tin oxide, indium oxide and the like.

The conductive substrate may have a sheet shape, a drum shape, or the like, depending on the structure of the image forming apparatus used. The substrate itself may be conductive, or the surface of the substrate may be conductive. Further, it is preferable that the conductive substrate has sufficient mechanical strength when used. When each layer constituting the photoreceptor is formed by a coating method, the charge generating agent, charge transporting agent, binder resin and the like exemplified above are used together with a suitable solvent in a known method,
For example, a roll mill, a ball mill, an attritor, a paint shaker or an ultrasonic disperser is used to disperse and mix to prepare a coating solution, which is coated by a known means.
Just dry.

As the solvent for forming the coating liquid, various organic solvents can be used, for example, alcohols such as methanol, ethanol, isopropanol and butanol, aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, Aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, dichloroethane, carbon tetrachloride, halogenated hydrocarbons such as chlorobenzene, dimethyl ether, diethyl ether, tetrahydrofuran,
Examples thereof include ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide and dimethyl sulfoxide. These solvents can be used alone or in combination of two or more.

Further, in order to improve the dispersibility of the charge transporting agent or the charge generating agent and the smoothness of the surface of the photosensitive layer, a surfactant, a leveling agent or the like may be added to the coating liquid.

[0061]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples. Examples 1 to 21 8 parts by weight of the bisazo pigment represented by the general formula (1), which is a charge generating agent, and 80 parts by weight of the phenylenediamine derivative represented by the general formula (2), which is a charge transport agent. And 20 parts by weight of the triphenylamine derivative represented by the general formula (3), which is also a charge transfer agent, and 100 parts by weight of a polycarbonate, which is a binder resin, together with a predetermined amount of tetrahydrofuran, and an ultrasonic disperser. The mixture was mixed and dispersed for 2 minutes to prepare a coating liquid for a single-layer type photosensitive layer.

Then, this coating solution was applied onto an aluminum base tube having an outer diameter of 78 mm and a length of 340 mm by a dip coating method, dried by heating at 100 ° C. for 30 minutes, and a single layer type photosensitive film having a film thickness of 24 μm. A single-layer type electrophotographic photosensitive member having a layer was produced. Examples 22 to 24 70 parts by weight of the phenylenediamine derivative represented by the general formula (2) in the coating liquid, and the triphenylamine derivative represented by the general formula (3) in the coating liquid. An electrophotographic photoreceptor having a single-layer type photosensitive layer was produced in the same manner as in Examples 1 to 21 except that the amount was 30 parts by weight. Examples 25 to 27: 60 parts by weight of the phenylenediamine derivative represented by the general formula (2) in the coating liquid, and the triphenylamine derivative represented by the general formula (3) in the coating liquid. An electrophotographic photoreceptor having a single-layer type photosensitive layer was produced in the same manner as in Examples 1 to 21 except that the amount was 40 parts by weight. Comparative Example 1 An electrophotographic photoreceptor having a single-layer type photosensitive layer was produced in the same manner as in Examples 1 to 21 except that the triphenylamine derivative represented by the general formula (3) was not added to the coating solution. did. Comparative Example 2 The triphenylamine derivative represented by the general formula (3) was not blended in the coating liquid, and the amount of the phenylenediamine derivative represented by the general formula (2) was 100 parts by weight in the coating liquid. An electrophotographic photoreceptor having a single-layer type photosensitive layer was produced in the same manner as in Examples 1 to 21 except that the above was performed.

With respect to the electrophotographic photosensitive members of the above-mentioned respective Examples and Comparative Examples, the following electrical characteristic test I was carried out to evaluate the characteristics. Electrical Property Test I The electrophotographic photoconductors of Examples and Comparative Examples were mounted on a drum sensitivity tester [CYNTHIA 30M] manufactured by GENTEC, and a voltage was applied to the surface thereof. The surface potential when positively charged was measured as the initial surface potential V _O (V).

Next, the surface of the charged photoreceptor is
Using a halogen lamp, which is an exposure light source of the tester, exposure was performed under the conditions of a light intensity of 0.92 mW / cm ² and an exposure time of 1 second until the surface potential became 1/2 of the initial surface potential V _O. The half-exposure dose E _1/2 (μJ / cm
² ) was calculated, and the surface potential 0.15 seconds after the start of exposure was measured as the residual potential V _R (V).

Further, the electrophotographic photoreceptors of Examples and Comparative Examples were irradiated with yellow light of a yellow fluorescent lamp (light intensity of 4000 Lux) for 20 minutes, and then the residual potential V _R was measured in the same manner as above.
(V) is measured, and the increase width ΔV with respect to the same measured value before exposure
_R (V) was calculated. The above results are shown in Tables 1-3. The bisazo pigments (1) used in each of the above Examples and Comparative Examples
Specific compounds of the phenylenediamine derivative (2) and the triphenylamine derivative (3) are shown in Tables 1 to 3 by using the compound numbers of the above specific examples.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

Examples 28 to 33 100 parts by weight of the bisazo pigment represented by the general formula (1), which is a charge generating agent, and 100 parts by weight of polyvinyl butyral, which is a binder resin, together with a predetermined amount of tetrahydrofuran, The mixture was stirred for 24 hours with a ball mill to prepare a coating liquid for the charge generation layer.

Then, this coating solution was applied onto an aluminum base tube having an outer diameter of 78 mm and a length of 340 mm by a dip coating method and dried by heating at 100 ° C. for 30 minutes to generate a charge having a film thickness of 0.5 μm. Layers were formed. Next, 80 parts by weight of the phenylenediamine derivative represented by the general formula (2), which is a charge transfer agent, and the triphenylamine derivative 20 represented by the general formula (3), which is also a charge transfer agent, are used.
1 part by weight and 100 parts by weight of a binder resin, polycarbonate, are mixed with a predetermined amount of toluene by stirring with a homomixer to prepare a coating solution for the charge transport layer, and the coating solution is used to generate the above-mentioned charge. It is coated on the layer by the dip coating method and dried by heating at 100 ° C. for 30 minutes to give a film thickness of 2
A 0 .mu.m charge transport layer was formed to produce a laminated electrophotographic photoreceptor. Comparative Example 3 An electron having a laminated photosensitive layer was prepared in the same manner as in Examples 28 to 33, except that the triphenylamine derivative represented by the general formula (3) was not added to the coating solution for the charge transport layer. A photographic photoreceptor was manufactured. Comparative Example 4 The triphenylamine derivative represented by the general formula (3) was not blended in the coating solution for the charge transport layer, and the phenylenediamine derivative represented by the general formula (2) was used for the charge transport layer. Example 2 except that the blending amount in the coating liquid was 100 parts by weight.
An electrophotographic photosensitive member having a laminated photosensitive layer was manufactured in the same manner as in Nos. 8 to 33.

With respect to the electrophotographic photosensitive members of the above-mentioned respective Examples and Comparative Examples, the following electrical characteristic test II was conducted to evaluate the characteristics. Electrical Property Test II The electrophotographic photoconductors of Examples and Comparative Examples were mounted on a drum sensitivity tester [CYNTHIA 30M] manufactured by GENTEC, and a voltage was applied to the surface thereof. The surface potential when negatively charged was measured as the initial surface potential V _O (V).

Next, the surface of the charged photoreceptor is
Using a halogen lamp, which is an exposure light source of the tester, exposure was performed under the conditions of a light intensity of 0.92 mW / cm ² and an exposure time of 1 second until the surface potential became 1/2 of the initial surface potential V _O. The half-exposure dose E _1/2 (μJ / cm
² ) was calculated, and the surface potential 0.15 seconds after the start of exposure was measured as the residual potential V _R (V).

Further, the electrophotographic photoreceptors of Examples and Comparative Examples were irradiated with yellow light (light intensity of 4000 Lux) of a yellow fluorescent lamp for 20 minutes, and then the residual potential V _R was measured in the same manner as above.
(V) is measured, and the increase width ΔV with respect to the same measured value before exposure
_R (V) was calculated. The results are shown in Table 4. The bisazo pigments (1), phenylenediamine derivatives (2) and triphenylamine derivatives used in each of the examples and comparative examples above.
The specific compounds of (3) are shown in Table 4 using the compound numbers of the specific examples described above, as in the above.

[0074]

[Table 4]

[0075]

As described above in detail, the electrophotographic photoreceptor of the present invention is a combination of a bisazo pigment having a specific structure, a phenylenediamine derivative, and a triphenylamine derivative, and therefore has excellent photosensitivity. It also has excellent light resistance.

Front page continued (72) Inventor Toshikazu Uegaki 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Prefecture Mita Kogyo Co., Ltd. (72) Sakae Saito 1-2-2 Tamatsukuri, Chuo-ku, Osaka City, Osaka Prefecture No. Mita Industry Co., Ltd. (72) Inventor Maki Uchida 1-2-2 Tamatsukuri Chuo-ku, Osaka City, Osaka Prefecture Mita Industry Co., Ltd.

Claims (1)

[Claims] 1. A charge-generating agent represented by the general formula (1): embedded image on a conductive substrate. [Wherein A ¹ and A ² represent the same or different coupler residues, and R ¹ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a substituent. The heterocyclic group which may be shown is shown. a represents an integer of 0 or 1. ] And a bisazo pigment represented by the general formula (2): [Wherein R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are the same or different and each have an alkyl group which may have a substituent, an alkoxy group which may have a substituent or a substituent Represents an optionally substituted aryl group or an optionally substituted alkylamino group. b, c, d, e and f are the same or different and are 0
Indicates an integer of ˜2. ] And a phenylenediamine derivative represented by the general formula (3): [In the formula, R ^A , R ^B and R ^C are the same or different and are each an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryl group which may have a substituent or The alkylamino group which may have a substituent is shown. α, β
And γ are the same or different and each represents an integer of 0 to 3. ]
An electrophotographic photoreceptor comprising a photosensitive layer containing a triphenylamine derivative represented by