JPH11153874A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the electrophotographic photoreceptor reduced in the surface friction coefficient of the photosensitive layer without impairing superior electro photographic characteristics and enhanced in coil resistance and yet free from any optical fatigue by incorporating a specified polycarbonate copolymer as a binder resin and a specified triphenylamine compound as a charge transfer agent in the photosensitive layer. SOLUTION: The photosensitive layer contains as the binder resin the polycarbonate copolymer having repeating units represented by formula I and as the charge transfer agent the triphenylamine compound represented by formula II. In formulae I and II, each of R1 -R12 , is, independently, a 1-6C alkyl or 6-12C aryl group: each of (a)-(c) is, undependently, an integer of 2-6; (d) is an integer of 0-200; each of R23 -R22 is, independently, an H or halogen atom, or a 1-6C alkyl or alkoxy or optionally substituted aryl group; and (k) us 0 or 1.

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 for an electrophotographic apparatus such as a copying machine or a laser beam printer, and more particularly to an electrophotographic photosensitive member using an organic photoconductive material. .

[0002]

2. Description of the Related Art In general, inorganic materials such as selenium (Se), cadmium sulfide (CdS), zinc oxide (ZnO), and amorphous silicon (a-Si) are used as a photoconductive material of an electrophotographic photosensitive member. However, a photoreceptor using such an inorganic material is charged in a dark place by, for example, a charging roller, and then formed into an electrostatic latent image by selectively exposing only the exposed portion by performing image exposure. Further, it is used as if it were visualized with a developer to form an image. The basic characteristics required for such an electrophotographic photoreceptor include that it can be charged to an appropriate potential in a dark place, that it has a function of eliminating surface charges by light irradiation, and the like. Each has its strengths and weaknesses. For example, selenium (S
e) satisfies the above-mentioned properties sufficiently, but has drawbacks in that it is difficult to process it into a film because it is inflexible, and that it is sensitive to heat and mechanical shock and requires careful handling. . Further, amorphous silicon (a-Si) has disadvantages in that manufacturing conditions are difficult and manufacturing costs are high.

[0003] For this reason, recently, as an electrophotographic photoreceptor, a function constituted by using a phthalocyanine or an azo compound known as an organic photoconductive substance as a charge generation layer and further laminating a charge transfer layer made of a hydrazone compound or the like. Separate organic photoreceptors have become mainstream.

[0004]

By the way, conventionally,
As the binder resin for the organic photoreceptor, bisphenol A type polycarbonate resin is most commonly used. However, when a photosensitive layer is formed using a bisphenol A type polycarbonate resin as a binder resin,
There are disadvantages such as that the coating solution for the photosensitive layer is not stable. Therefore, there is a demand for a material for the charge transfer layer that does not have such disadvantages.

Further, since the photosensitive layer using this resin has a large friction coefficient on the surface, when the electrophotographic photosensitive member is mounted on an electrophotographic apparatus and the electrophotographic process is repeated, cleaning of residual toner on the surface of the photosensitive layer is performed. However, there have been problems such as the inversion of the cleaning blade generally used and the generation of abnormal noise.

Further, since the polycarbonate resin has poor oil resistance, the surface of the photosensitive layer may be erroneously touched during maintenance of an electrophotographic apparatus, and a fingerprint may be attached. In many cases, cracks occur in the damaged portion, making the electrophotographic photosensitive member unusable.

On the other hand, in consideration of the stability of a coating solution, it has been proposed to use a bisphenol Z-type polycarbonate resin as a material for a photosensitive layer of an electrophotographic photosensitive member. However, even if this bisphenol Z-type polycarbonate resin is used, it has not been possible to solve problems such as winding of the blade due to a large friction coefficient, generation of abnormal noise and cracks.

Then, as described in, for example, JP-A-4-179951, the above-mentioned bisphenol A type, Z
Polycarbonate resins and polycarbonate copolymers having various structures other than molds have been developed, but none have yet been found that can solve all of the above-mentioned problems.

On the other hand, the electrophotographic photosensitive member may be exposed to room light or the like during maintenance or replacement of the electrophotographic photosensitive member. And the residual potential of the electrophotographic photosensitive member increases. Such a situation is a major obstacle to simplifying maintenance. For this reason, maintenance must be performed by a skilled service person, and the service person must also pay close attention.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and it is intended to reduce the coefficient of friction of the photosensitive layer surface without impairing excellent electrophotographic characteristics and to improve oil resistance. Another object of the present invention is to provide an electrophotographic photosensitive member free from light fatigue.

[0011]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as a binder resin, a polycarbonate copolymer having a specific structure and a charge having a specific structure as a binder resin in the photosensitive layer. The present inventors have found that an electrophotographic photoreceptor using a transfer agent does not have the above-mentioned problems of the prior art and maintains excellent electrostatic characteristics for a long period of time, and has completed the present invention.

The invention according to claim 1, which has been made based on such a viewpoint, provides an electrophotographic photosensitive member having a photosensitive layer having at least a charge generating agent, a charge transfer agent and a binder resin formed on a conductive support. The photosensitive layer contains a polycarbonate copolymer containing a repeating unit represented by the general formula [I] as a binder resin and a triphenylamine compound represented by a general formula [IV] as a charge transfer agent. Characteristic electrophotographic photoreceptor.

[0013]

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[Wherein, R _{1 to} R ₁₂ each independently have 1 carbon atom.
Represents an alkyl group of 6 to 6 or an aromatic hydrocarbon group of 6 to 12 carbon atoms, a to c each independently represent an integer of 2 to 6, and d represents an integer of 0 to 200. ]

[0015]

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Wherein R _{23 to} R ₂₇ may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 6 carbon atoms, or a substituent And k represents an integer of 0 or 1. ]

In the case of the invention according to claim 1 having such a structure, the photosensitive layer contains a polycarbonate copolymer containing a repeating unit having a siloxane structure represented by the general formula [I] as a binder resin. In addition, since the releasability and lubricity are improved, the friction coefficient of the photosensitive layer is reduced.

Further, by containing a triphenylamine compound represented by the general formula [IV] as a charge transfer agent, light fatigue is reduced.

In this case, as in the second aspect of the present invention,
In the invention according to claim 1, a general formula [I], a general formula [II] and a general formula [III] are used as a binder resin in the photosensitive layer.
And a polycarbonate copolymer comprising a repeating unit represented by the formula:

[0020]

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[Wherein R _{1 to} R ₁₂ each independently represent a carbon atom of 1
Represents an alkyl group of 6 to 6 or an aromatic hydrocarbon group of 6 to 12 carbon atoms, a to c each independently represent an integer of 2 to 6, and d represents an integer of 0 to 200. ]

[0022]

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Wherein A is a single bond, -O-, -CO
-, - S -, - SO -, - SO 2 -, - CR 15 R 16 -
(However, R ₁₅ and R ₁₆ each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms.) A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, a 9,9-fluorenylidene group, or a carbon atom having 2 carbon atoms
Represents any one of α to ω-alkylene groups. R ₁₃ and R ₁₄ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms, e and f
Each independently represents an integer of 0 to 4. ]

[0024]

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Wherein B is a single bond, -O-, -CO
-, - S -, - SO -, - SO 2 -, - CR 19 R 20 -
(However, R ₁₉ and R ₂₀ each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms.) A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a functional group represented by the general formula [III ′]. R ₁₇ and R ₁₈ each independently represent a halogen atom,
Represents an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. Here, B is -O -, - CO -, - S -, - SO -, - SO 2
_{-, - CR 19 R 20 -} , 1,1- cycloalkylidene group having 5 to 8 carbon atoms, or α 2 to 12 carbon atoms, when any of the ω- alkylene group, g and h are each independently Represents an integer of 1 to 4. When B is a single bond or a functional group represented by the general formula [III ′], g and h each independently represent an integer of 0 to 4. ]

[0026]

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[In the formula, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. , D is a single bond, -O-, -C
O -, - S -, - SO-, or -SO ₂ - represents one of, i and j represent each independently an integer from 0-4. ]

In the case of the invention of claim 2, in addition to the repeating unit represented by the general formula [I] as a binder resin in the photosensitive layer, the repeating unit represented by the general formula [II] or [III] By containing a polycarbonate copolymer obtained by copolymerizing units, toner filming resistance is improved.

In particular, as in the invention according to the third aspect, in the invention according to the second aspect, the repeating units represented by the formulas (Ia), (IIa) and (IIIa) are used as a binder resin in the photosensitive layer. It may also contain a polycarbonate copolymer composed of units.

[0030]

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[0031]

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[0032]

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The third aspect of the present invention is preferable in terms of low friction coefficient, high printing durability and oil resistance.

Further, as in the invention according to the fourth aspect, in the invention according to the second aspect, a repeating resin represented by the formulas (Ia), (IIa) and (IIIb) as a binder resin in the photosensitive layer. It may also contain a polycarbonate copolymer composed of units.

[0035]

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[0036]

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[0037]

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The invention according to claim 4 is also preferable in terms of a small coefficient of friction, high printing durability and oil resistance.

Further, as in the fifth aspect of the present invention, in the second aspect of the present invention, the binder resin in the photosensitive layer is represented by the formulas (Ia), (IIa) and (IIIc). It may contain a polycarbonate copolymer composed of repeating units.

[0040]

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[0041]

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[0042]

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The invention described in claim 5 is also preferable in terms of a low coefficient of friction, high printing durability and oil resistance.

In the invention according to any one of the first to fifth aspects, a triphenylamine compound represented by the formula [IVa] may be used as the charge transfer agent. it can.

[0045]

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The sixth aspect of the present invention is preferable in that the sensitivity of the photoreceptor becomes high and the photoreceptor becomes strong.

Further, as in the invention according to claim 7, in the invention according to any one of claims 1 to 5, two kinds of triphenylamine compounds represented by the formula [IVb] can be used as the charge transfer agent. Mixtures can also be used.

[0048]

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The invention described in claim 7 is also preferable in that the sensitivity of the photoreceptor becomes high and the photoreceptor becomes strong.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the electrophotographic photosensitive member according to the present invention will be described below in detail. The present invention
For example, a function separation type electrophotographic photoreceptor in which a charge generation layer containing at least a charge generation agent is formed on a conductive support, and a charge transfer layer containing at least a charge transfer agent is formed thereon. Applicable. in this case,
A photosensitive layer is formed by the charge generation layer and the charge transfer layer.

The present invention also relates to a single-layer type electrophotographic photoreceptor in which a charge generating agent and a charge transfer agent are contained in the same layer, and an inversely laminated type electrophotographic photoreceptor in which a charge transfer layer and a charge generation layer are laminated in this order. The invention can be applied to a photoreceptor and the like.

Examples of the conductive support usable in the present invention include simple metals such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum and indium, and alloys thereof. Processed products and conductive materials such as the above metals and carbon, which are treated by vapor deposition, plating, etc., to give conductive plastic plates and films, and conductive materials coated with tin oxide, indium oxide, and aluminum iodide. The conductive support can be formed by using various conductive materials, such as conductive glass, without being limited by the type or shape. The conductive support may be in the form of a drum, a rod, a plate, a sheet, or a belt.

As the charge generating agent that can be used in the present invention, disazo pigments and oxytitanium phthalocyanine are preferable in terms of good sensitivity compatibility, but are not limited thereto. Others, for example, selenium, selenium-tellurium, selenium-arsenic, amorphous silicon, metal-free phthalocyanine, other metal phthalocyanine pigments, monoazo pigments, trisazo pigments, polyazo pigments, indigo pigments,
Slen pigments, toluidine pigments, pyrazoline pigments, perylene pigments, quinacridone pigments, polycyclic quinone pigments, pyrylium salts and the like can be used.

These charge generating agents may be used alone or in combination of two or more in order to obtain an appropriate photosensitivity wavelength and sensitizing effect.

The electrophotographic photoreceptor of the present invention contains a polycarbonate copolymer containing a repeating unit having a siloxane structure represented by the general formula [I] as a binder resin in the photosensitive layer. By having the siloxane structural unit, the coefficient of friction of the photosensitive layer can be reduced.

[0055]

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[Wherein, R _{1 to} R ₁₂ each independently have 1 carbon atom.
Represents an alkyl group of 6 to 6 or an aromatic hydrocarbon group of 6 to 12 carbon atoms, a to c each independently represent an integer of 2 to 6, and d represents an integer of 0 to 200. ]

In addition, the polycarbonate copolymer of the present invention can have, as a repeating unit, a polycarbonate structural unit represented by the general formulas [II] and [III] in addition to the siloxane structural unit. These polycarbonate structural units can be appropriately selected depending on their properties, ease of synthesis, use of the resin, and the like.

[0058]

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[Wherein A is a single bond, -O-, -CO
-, - S -, - SO -, - SO 2 -, - CR 15 R 16 -
(However, R ₁₅ and R ₁₆ each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms.) A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, a 9,9-fluorenylidene group, or a carbon atom having 2 carbon atoms
Represents any one of α to ω-alkylene groups. R ₁₃ and R ₁₄ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms, e and f
Each independently represents an integer of 0 to 4. ]

[0060]

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[Wherein B is a single bond, -O-, -CO
-, - S -, - SO -, - SO 2 -, - CR 19 R 20 -
(However, R ₁₉ and R ₂₀ each independently represent a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms.) A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a functional group represented by the general formula [III ′]. R ₁₇ and R ₁₈ each independently represent a halogen atom,
Represents an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. Here, B is -O -, - CO -, - S -, - SO -, - SO 2
_{-, - CR 19 R 20 -} , 1,1- cycloalkylidene group having 5 to 8 carbon atoms, or α 2 to 12 carbon atoms, when any of the ω- alkylene group, g and h are each independently Represents an integer of 1 to 4. When B is a single bond or a functional group represented by the general formula [III ′], g and h each independently represent an integer of 0 to 4. ]

[0062]

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[Wherein, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. , D is a single bond, -O-, -C
O -, - S -, - SO-, or -SO ₂ - represents one of, i and j represent each independently an integer from 0-4. ]

In this case, for example, the formula [Ia], the formula [II
a] and the formula [IIIa] or the formula [Ia], the formula [II
a] and the formula [IIIb] or the formula [Ia], the formula [II
a) and a polycarbonate copolymer comprising a repeating unit represented by the formula [IIIc] can be used.

[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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In the case of a polycarbonate copolymer having two or more kinds of repeating units, the content of the repeating unit represented by the general formula [I] is the same as the number of moles of the repeating unit represented by the general formula [I] The molar ratio to the total number of moles of the repeating unit is desirably 0.0001 or more. When the content of the repeating unit represented by the general formula [I] is less than 0.0001, the effect of improving filming resistance is not sufficiently exhibited.

Further, the polycarbonate copolymer is as follows:
A reduced viscosity (ηSP / c) at 20 ° C. of a solution having a concentration of 0.5 g / dl using methylene chloride as a solvent is 0.70 dl.
/ G or more is preferable because the hardness of the formed photosensitive layer is increased.

When the structure of the photosensitive layer is a lamination type or a reverse lamination type, the binder resin of the present invention may be used for one or both of the charge generation layer and the charge transfer layer. In view of its properties, the resin is preferable when contained in the outermost surface layer because desired properties are sufficiently exhibited.

On the other hand, in the electrophotographic photoreceptor of the present invention, the photosensitive layer may contain a binder resin other than the above-mentioned specific polycarbonate copolymer.

Examples of the binder resin that can be used to form the photosensitive layer include polycarbonate resin, styrene resin, acrylic resin, styrene-acryl resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, and chlorinated polystyrene. Ether, vinyl chloride-vinyl acetate resin, polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, diallylate resin, polysulfone resin, polyether Sulfone resin, polyallyl sulfone resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin,
EVA (ethylene / vinyl acetate / copolymer) resin, AC
Examples include S (acrylonitrile / chlorinated polyethylene / styrene) resin, ABS (acrylonitrile / butadiene / styrene) resin, and photocurable resins such as epoxy arylate. These may be used alone or in combination of two or more. It is more preferable to use a mixture of resins having different molecular weights because the hardness and abrasion resistance can be improved.

The electrophotographic photoreceptor of the present invention contains a triphenylamine compound represented by the general formula [IV] as a charge transfer agent in the photosensitive layer.

[0076]

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[Wherein, R _{23 to} R ₂₇ may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl or alkoxy group having 1 to 6 carbon atoms, or a substituent And k represents an integer of 0 or 1. ]

In this case, the general formula [IV] in the charge transfer layer
The content of the triphenylamine compound represented by is preferably 0.3 to 2.0 parts by weight, more preferably 0.5 to 1.2 parts by weight, based on 1 part by weight of the binder resin. is there.

If the content of the triphenylamine compound is less than 0.3 parts by weight, the electric properties such as the residual potential are increased and the electric properties are deteriorated. On the other hand, if it is more than 2.0 parts by weight, mechanical properties such as abrasion resistance deteriorate.

Among the triphenylamine compounds represented by the general formula [IV], particularly, a triphenylamine compound represented by the formula [IVa] or a mixture of the triphenylamine compounds represented by the formula [IVb] Is effective in not causing light fatigue.

[0081]

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[0082]

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Further, another charge transfer agent can be added to the photosensitive layer of the electrophotographic photosensitive member of the present invention. In this case, the sensitivity of the photosensitive layer can be increased or the residual potential can be reduced, so that the characteristics of the electrophotographic photosensitive member of the present invention can be improved.

Examples of charge transfer agents that can be added to improve such properties include polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine,
Polyvinyl pyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrosenylene, polyperinaphthylene, polyphthalocyanine And other conductive high molecular compounds can be used.

Examples of low molecular compounds include polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene; trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoquinone, naphthoquinone, anthraquinone and derivatives thereof; Indole, carbazole, nitrogen-containing heterocyclic compounds such as imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, triphenylmethane, enamine, stilbene, butadiene, hydrazone, other triphenylamine compounds and the like as a charge transfer agent Can be added.

As the charge transfer agent for the same purpose, a polymer solid electrolyte in which a polymer compound such as polyethylene oxide, polypropylene oxide, polyacrylonitrile and polymethacrylic acid is doped with a metal ion such as Li (lithium) ion is used. It can also be added.

Further, as a charge transfer agent for the same purpose,
An organic charge transfer complex formed of an electron-donating substance and an electron-accepting substance represented by tetrathiafulvalene-tetracyanoquinodimethane can also be used.

The desired photoreceptor characteristics can be obtained by adding only one kind of the charge transfer agent or by mixing two or more kinds of compounds.

The electrophotographic photoreceptor of the present invention can prevent the property change and the crack due to the oxidative deterioration of the photoconductive material and the binder resin,
For the purpose of improving the mechanical strength, the photosensitive layer preferably contains an antioxidant or an ultraviolet absorber.

The antioxidants which can be used in the present invention include 2,6-di-tert-butylphenol and 2,6-di-tert-butylphenol.
4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-
Di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl-propionate-β- (3,5-di-
tert-butyl-4-hydroxyphenyl), α-tocopherol, β-tocopherol, n-octadecyl-3- (3′-5′-
Monophenols such as di-tert-butyl-4'-hydroxyphenyl) propionate and 2,2'-methylenebis (6-tert-
Butyl-4-methylphenol), 4,4'-butylidene-bis
-(3-methyl-6-tert-butylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris
(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene And polyphenols such as tetrakis [methylene-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane and the like, and one or more of these should be simultaneously contained in the photosensitive layer. Can be.

As the ultraviolet absorber, 2- (5-methyl)
2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di-tert-butyl-
2-hydroxyphenyl) benzotriazole, 2- (3-tert
-Butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5 -Ji-
benzotriazoles such as tert-amyl-2-hydroxyphenyl) benzotriazole and 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, phenyl salicylate, p-tert-butylphenyl salicylate, salicylic acid Salicylic acids such as p-octylphenyl are preferred, and one or more of these can be simultaneously contained in the photosensitive layer.

Further, an antioxidant and an ultraviolet absorber can be added simultaneously. These additives may be added to any layer in the photosensitive layer, but are preferably added to the outermost surface layer, particularly to the charge transfer layer.

The amount of the antioxidant added is preferably 3 to 20% by weight based on the binder resin, and the amount of the ultraviolet absorber added is 3 to 30% by weight based on the binder resin. Is preferred. Further, when both the antioxidant and the ultraviolet absorber are added, the addition amount of both components is preferably 5 to 40% by weight based on the binder resin.

In addition to the antioxidants and ultraviolet absorbers,
Light stabilizers such as hindered amines and hindered phenol compounds, anti-aging agents such as diphenylamine compounds, surfactants and the like can also be added to the photosensitive layer.

As a method for forming a photosensitive layer, a method is generally used in which a coating liquid is prepared by dispersing or dissolving a predetermined photosensitive material and a binder resin in a solvent, and coating the coating on a predetermined substrate.

The coating method may be dip coating, curtain flow, bar coating, roll coating, ring coating, spin coating, spray coating, etc., depending on the shape of the base and the state of the coating liquid. Further, the charge generation layer can be formed by a vacuum evaporation method.

The solvent used for the coating solution is methanol,
Ethanol, n-propanol, i-propanol, alcohols such as butanol, pentane, hexane, heptane, octane, cyclohexane, saturated aliphatic hydrocarbons such as cycloheptane, aromatic hydrocarbons such as toluene and xylene, dichloromethane, dichloroethane, Chlorine hydrocarbons such as chloroform and chlorobenzene, dimethyl ether, diethyl ether, tetrahydrofuran (TH
F), ethers such as methoxyethanol, acetone,
Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl formate, propyl formate,
Methyl acetate, ethyl acetate, propyl acetate, butyl acetate,
Esters such as methyl propionate, N, N-dimethylformamide, dimethyl sulfoxide and the like. These may be used alone or as a mixture of two or more solvents.

In the electrophotographic photosensitive member according to the present invention,
Between the conductive support and the photosensitive layer, an intermediate layer having an adhesive function, a barrier function, a function of covering the surface of the support with defects, and the like may be provided. As this intermediate layer, aluminum oxide, polyethylene resin, acrylic resin, epoxy resin, polycarbonate resin, polyurethane resin, vinyl chloride resin,
A vinyl acetate resin, a polyvinyl butyral resin, a polyamide resin, a nylon resin, or the like can be used. These intermediate layers may be composed of a single resin, or may be composed of a mixture of two or more resins.

Further, a metal compound, a metal oxide,
An intermediate layer in which carbon, silica, resin powder and the like are dispersed can also be used. Furthermore, various pigments for improving properties,
An electron-accepting substance, an electron-donating substance, and the like can be contained.

In addition, on the surface of the photosensitive layer, an organic thin film such as a polyvinyl formal resin, a polycarbonate resin, a fluorine resin, a polyurethane resin, or a silicon resin, or a siloxane structure formed of a hydrolyzate of a silane coupling agent is formed. A surface protection layer may be provided by forming a thin film,
In that case, the durability of the photoconductor is improved, which is preferable. This surface protective layer may be provided to improve functions other than the enhancement of durability.

[0101]

Hereinafter, examples of the electrophotographic photosensitive member according to the present invention will be described in detail along with comparative examples. Example 1 A charge generating layer was formed on a cylindrical drum made of aluminum having a diameter of 30 mm by applying a dispersion of α-type oxytitanium phthalocyanine using polyvinyl butyral as a binder resin at 0.1 μm by dip coating. .

Next, a polycarbonate copolymer represented by the formula [Ia], [IIa] and [IIIa] as a binder resin, and a triphenylamine compound represented by the formula [IVa] as a charge transfer agent were used. 2,6 as antioxidants
-Di-tert-butyl-4-methylphenol and 2- (5-methyl-2-hydroxyphenyl) benzotriazole as an ultraviolet absorber, polycarbonate copolymer / formula [IVa]
/ Antioxidant / ultraviolet absorber = 1.0 / 0.8 / 0.1
It was dissolved in chloroform at a weight ratio of 8 / 0.1 to prepare a coating solution.

[0103]

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[0104]

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[0105]

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[0106]

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Here, the molar ratio of the repeating units of the polycarbonate copolymer is represented by the formula [Ia] / formula [IIa] / formula [I
IIa] = 0.01 / 0.85 / 0.14, and the reduced viscosity in that case was 1.63 dl / g.

Then, after applying this coating solution by dip coating, it was dried at a temperature of 100 ° C. for 1 hour to form a charge transfer layer having a thickness of 20 μm. An electrophotographic photoreceptor was manufactured by the method described above.

Example 2 Instead of the polycarbonate copolymer of Example 1, the molar ratio of the repeating units was of the formula [Ia]
/ Formula [IIa] / Formula [IIIa] = 0.001 / 0.8
An electrophotographic photoreceptor was produced in the same manner as in Example 1, except that a polycarbonate copolymer having a reduced viscosity of 5 / 0.149 and a reduced viscosity of 0.77 dl / g was used as a binder resin.

Example 3 Instead of the polycarbonate resin of Example 1, Formulas (Ia), (IIa) and (II)
An electrophotographic photoreceptor was produced in the same manner as in Example 1 using the polycarbonate copolymer represented by Ic].

[0111]

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[0112]

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[0113]

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Here, the molar ratio of the repeating units of the polycarbonate copolymer is represented by the formula [Ia] / formula [IIa] / formula [I
IIc] = 0.001 / 0.82 / 0.179, and the reduced viscosity in that case was 1.77 dl / g.

Example 4 Instead of the charge transfer agent represented by the formula [IVa] of Example 1, 2 represented by the formula [IVb] was used.
An electrophotographic photoreceptor was produced in the same manner as in Example 1 using a mixture of various kinds of triphenylamine compounds.

[0116]

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Example 5 A dispersion of a disazo pigment using polyvinyl butyral as a binder resin was applied to a thickness of 0.1 μm on a cylindrical drum made of aluminum having a diameter of 30 mm by dip coating to form a charge generation layer. .

Then, a polycarbonate copolymer represented by the formula [Ia], [IIa] and [IIIb] is used as a binder resin, and a triphenylamine compound represented by the formula [IVa] is used as a charge transfer agent. And 2,6 as antioxidants
-Di-tert-butyl-4-methylphenol and 2- (5-methyl-2-hydroxyphenyl) benzotriazole as an ultraviolet absorber, a polycarbonate copolymer / formula [IV
a] / antioxidant / ultraviolet absorber = 1.0 / 0.8 /
It was dissolved in chloroform at a weight ratio of 0.18 / 0.1 to prepare a coating solution. Here, the molar ratio of the repeating unit of the polycarbonate copolymer is represented by the formula [Ia] / the formula [IIa] /
Formula [IIIb] = 0.01 / 0.85 / 0.14,
The reduced viscosity in that case was 1.62 dl / g. Then, after applying this coating liquid by dip coating, the temperature is set to 100 ° C.
At a temperature of 1 hour to form a charge transfer layer having a thickness of 20 μm. An electrophotographic photoreceptor was manufactured by the method described above.

[0119]

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[0120]

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[0121]

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[0122]

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Example 6 A charge generation layer was formed in the same manner as in Example 5, and then the molar ratio of the repeating unit was changed to the formula [Ia] /
Formula [IIa] / Formula [IIIb] = 0.001 / 0.85
A charge transfer layer was formed in the same manner as in Example 1 by using a polycarbonate copolymer having a reduced viscosity of 1.64 dl / g / 0.149 and a reduced viscosity of 1.64 dl / g to produce an electrophotographic photosensitive member.

Comparative Example 1 Instead of the polycarbonate copolymer of Example 1, a polycarbonate having a reduced viscosity of 0.72 dl / g having a repeating unit of the formula [IIa] was used as a binder resin. In this case, the formula [IIa] / the formula [IV
a] / antioxidant / ultraviolet absorber = 1.0 / 0.8 /
It was dissolved in chloroform at a weight ratio of 0.18 / 0.1 to prepare a coating solution. Then, a charge transfer layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member.

[0125]

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Comparative Example 2 A method similar to that of Comparative Example 1 was repeated, except that the polycarbonate of Comparative Example 1 was replaced by a polycarbonate having a reduced viscosity of 0.75 dl / g having the formula [IIb] as a repeating unit. To form an electrophotographic photosensitive member.

[0127]

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Comparative Example 3 Instead of the polycarbonate of Comparative Example 1, a polycarbonate copolymer having repeating units of the formulas [IIa] and [IIIa] was used as a binder resin. Here, the composition (molar) ratio of the repeating unit of the polycarbonate copolymer is represented by the formula [IIa] / formula [IIIa] =
0.8 / 0.2, in which case the reduced viscosity is 0.76 d
1 / g. Then, a charge transfer layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member.

[0129]

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[0130]

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Comparative Example 4 Instead of the polycarbonate of Comparative Example 1, a polycarbonate copolymer having a repeating unit of the formulas [IIa] and [IIIb] was used as a binder resin. In this case, the composition (molar) ratio of the repeating unit of the polycarbonate copolymer is represented by the formula [IIa] / formula [III
b] = 0.9 / 0.1 Then, a charge transfer layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member.

[0132]

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[0133]

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Comparative Example 5 An electrophotographic method was performed in the same manner as in Example 1 except that the compound represented by the formula [Va] was used instead of the charge transfer agent represented by the formula [IVa] in Example 1. The body was made.

[0135]

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Comparative Example 6 An electrophotographic method was performed in the same manner as in Example 1 except that the compound represented by the formula [Vb] was used instead of the charge transfer agent represented by the formula [IVa] in Example 1. The body was made.

[0137]

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Comparative Example 7 An electrophotographic method was performed in the same manner as in Example 1 except that the compound represented by the formula [Vc] was used instead of the charge transfer agent represented by the formula [IVa] in Example 1. The body was made.

[0139]

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For evaluation of friction coefficient, 100 mm
The photosensitive layers of Examples and Comparative Examples were applied on a PET (polyethylene terephthalate) film on which aluminum having a size of 100 mm was deposited, to produce a sheet-shaped electrophotographic photosensitive member.

Evaluation Method [Measurement of Electrostatic Characteristics] The initial surface potential, sensitivity, residual potential, dark decay rate, etc. of the electrophotographic photosensitive members produced in Examples and Comparative Examples were measured using an electrophotographic photosensitive member evaluation apparatus. The electrostatic characteristics were measured, and all were good characteristics.

[Light Fatigue Test] Room temperature and normal humidity (24 ° C., 40%
(RH) environment, using an electrophotographic photoreceptor evaluation device,
The cylindrical electrophotographic photosensitive members produced in Examples 1 to 4 and Comparative Example were charged at an applied voltage of −5 KV, and the wavelength was 780.
The residual potential VR (-V) when the electrophotographic photoreceptor was exposed to light with an exposure light amount of 20 erg / cm 2 was measured.

On the other hand, the illuminance 800 l
ux fluorescent lamp light for 10 minutes, and then the residual potential VR1 (−V) is measured by the electrophotographic photoreceptor evaluation apparatus, and the difference in residual potential before and after the fluorescent lamp light irradiation (| VR−
VR1 |) was defined as ΔVR (V). Table 1 shows the results.

Examples 5 and 6 were the same as the other examples except that the residual potential VR (−V) when the electrophotographic photosensitive member was exposed using white light having an exposure light quantity of 2 Lux · sec was measured. Measured similarly.

[Measurement of Coefficient of Friction] The sheet-shaped electrophotographic photosensitive member prepared for evaluating the coefficient of friction was fixed on a flat surface, and the coefficient of static friction was measured using a friction coefficient measuring device (Tribogear Muse TYPE94B manufactured by HEIDON). . Table 1 shows the results.

[Image Test] The cylindrical electrophotographic photosensitive members produced in Examples and Comparative Examples were charged negatively by a brush charging method, and were exposed to an LED, non-magnetic one-component developing method, blade cleaning. A4 paper is attached to an electrophotographic apparatus that forms images by the
Sheets were continuously printed, and the image after continuous printing was evaluated. Table 1 shows the results.

On the other hand, the cylindrical electrophotographic photosensitive members produced in Examples and Comparative Examples were mounted on the electrophotographic apparatus after performing the light fatigue test, and the images were printed and evaluated. In this case, the judgment was “good” for “○”, and “x” for practically problematic due to image failure and the like.

[Evaluation of blade turnover and occurrence of abnormal noise]
During continuous printing of 5,000 sheets in the image test, the presence or absence of blade turning and the occurrence of abnormal noise of the blade were observed.
Table 1 shows the results. In this case, the judgment was "O" when no blade turning or abnormal noise occurred, and "X" when it occurred.

[Evaluation of Crack Occurrence] A fingerprint was attached to the surface of the electrophotographic photosensitive member and allowed to stand at room temperature and normal humidity for 24 hours.
The portion with the fingerprint was visually observed for the occurrence of cracks. Table 1 shows the results. In this case, the judgment is
A sample in which no cracks were generated was rated "○", and a sample in which cracks were generated was rated "x".

[0150]

[Table 1]

As is clear from Table 1, the electrophotographic photoreceptors of Examples 1 to 6 have a small coefficient of friction and have no curling of the blade or generation of abnormal noise. Did not occur.

Further, no crack was generated by the fingerprint,
Since there is almost no light fatigue, maintenance can be easily performed without a skilled service person.

In addition, as understood from Examples 2 and 6, good results were obtained even when the composition ratio of the repeating unit of the binder resin was changed.

The electrophotographic photosensitive member of Example 3 had a lower residual potential and exhibited better electrostatic characteristics than those of the other examples.

On the other hand, the electrophotographic photoreceptors of Comparative Examples 1 to 4 use the triphenylamine compound used in the present invention, so that the photo fatigue is small. However, since the polycarbonate copolymer used in the present invention is not used, the coefficient of friction is large, the blade is turned up and abnormal noise is generated, and the image after continuous printing is caused by poor cleaning, which is considered to be caused by poor cleaning. There were many black spots, white spots on black ground, and streak-like defects. In addition, during continuous printing, the electrophotographic apparatus had to be stopped many times because the blade was turned up or abnormal noise occurred.

In Comparative Examples 1 to 4, many cracks occurred due to the adhesion of fingerprints. When the electrophotographic photoreceptor having such cracks was mounted on an electrophotographic apparatus for evaluation and printed, the cracks appeared on the image and were impractical.

On the other hand, in Comparative Examples 5 to 7, since the polycarbonate copolymer used in the present invention was used, there was no curling, abnormal noise, or cracking of the blade, but it was used in the present invention. Since the triphenylamine compound was not used, the charge transfer agent was deteriorated by the light fatigue test, and a black background was formed on the white background image after the light fatigue, which was impractical.

[0158]

As described above, the electrophotographic photoreceptor of the present invention has a very small friction coefficient without being affected by electrostatic properties such as surface potential and sensitivity, and has a tendency to turn up the blade and to make noise. It does not occur at all, and exhibits strong durability against fingerprint adhesion, and is also resistant to light fatigue. Therefore, according to the present invention, excellent electrophotographic properties, cleaning properties,
An object of the present invention is to provide an electrophotographic photoreceptor having oil resistance and capable of simplifying maintenance.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 5/06 313 G03G 5/06 313

Claims (7)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer having at least a charge generating agent, a charge transfer agent and a binder resin on a conductive support, wherein the photosensitive resin has a general formula [I] An electrophotographic photosensitive member comprising: a polycarbonate copolymer containing a repeating unit represented by the formula: and a triphenylamine compound represented by the general formula [IV] as a charge transfer agent. Embedded image [Wherein, R _{1 to} R ₁₂ each independently represent an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c each independently represent 2 to 6 And d represents an integer of 0 to 200. [Chemical formula 2] [Wherein, R _{23 to} R ₂₇ may be the same or different, and each independently has a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group having 1 to 6 carbon atoms, or a substituent. And k represents an integer of 0 or 1. ] 2. A compound represented by the general formula [I]:
2. The electrophotographic photosensitive member according to claim 1, comprising a polycarbonate copolymer comprising a repeating unit represented by the general formulas [II] and [III]. Embedded image [Wherein, R _{1 to} R ₁₂ each independently represent an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and a to c each independently represent 2 to 6 And d represents an integer of 0 to 200. [Formula 4] [Wherein, A is a single bond, -O-, -CO-, -S-,-
SO—, —SO ₂ —, —CR ₁₅ R ₁₆ — (where R ₁₅ and R ₁₆ are each independently a hydrogen atom, a trifluoromethyl group,
Represents an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. ),
A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, 9,9
-Represents either a fluorenylidene group or an α, ω-alkylene group having 2 to 12 carbon atoms. R ₁₃ and R ₁₄ are
Each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms,
Or, it represents either an aryl group or a substituted aryl group having 6 to 12 carbon atoms, and e and f each independently represent an integer of 0 to 4. [Chemical formula 5] [Wherein B is a single bond, -O-, -CO-, -S-,-
SO—, —SO ₂ —, —CR ₁₉ R ₂₀ — (where R ₁₉ and R ₂₀ are each independently a hydrogen atom, a trifluoromethyl group,
Represents an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. ),
A 1,1-cycloalkylidene group having 5 to 8 carbon atoms, an α, ω-alkylene group having 2 to 12 carbon atoms, or a compound represented by the general formula [II
I ']. Also, R ₁₇
And R ₁₈ each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms. Where B is -O
-, - CO -, - S -, - SO -, - SO 2 -, - CR
₁₉ R ₂₀ -, 1,1-cycloalkylidene group of 5 to 8 carbon atoms, or α 2 to 12 carbon atoms, when any of the ω- alkylene group, g and h are each independently 1 to 4 Represents an integer. When B is a single bond or a functional group represented by the general formula [III ′], g and h each independently represent an integer of 0 to 4. [Formula 6] [Wherein, R ₂₁ and R ₂₂ each independently represent a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclohexyl group, or an aryl group or a substituted aryl group having 6 to 12 carbon atoms, and D is Single bond, -O-, -CO-, -S
—, —SO—, or —SO ₂ —, and i and j each independently represent an integer of 0 to 4. ] 3. A photosensitive layer containing a polycarbonate copolymer comprising repeating units represented by formulas [Ia], [IIa] and [IIIa] as a binder resin. The electrophotographic photosensitive member according to the above. Embedded image Embedded image Embedded image 4. A photosensitive layer containing a polycarbonate copolymer comprising repeating units represented by formulas [Ia], [IIa] and [IIIb] as a binder resin. The electrophotographic photosensitive member according to the above. Embedded image Embedded image Embedded image 5. The photosensitive layer contains a polycarbonate copolymer comprising repeating units represented by the formulas [Ia], [IIa] and [IIIc] as a binder resin. The electrophotographic photosensitive member according to the above. Embedded image Embedded image Embedded image 6. The method according to claim 1, wherein the charge transfer agent is a triphenylamine compound represented by the formula [IVa].
6. The electrophotographic photosensitive member according to any one of claims 1 to 5, Embedded image 7. The method according to claim 1, wherein the charge transfer agent is a triphenylamine compound represented by the formula [IVb].
6. The electrophotographic photosensitive member according to any one of claims 1 to 5, Embedded image