JPH11249325A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve resistance to a gas such as ozone or NOX and the fluctuation of potential such as a rise in a light part and a drop in a dark part at the time of repeated uses by incorporating a specified phenol compound in a photosensitive layer. SOLUTION: This electrophotographic photoreceptor is provided on a conductive substrate with a photosensitive layer containing a phenol compound represented by formula in which each of R1 -R3 is an H atom, a hydroxyl group, a substituted or unsubstituted alkyl group or has a substituted or unsubstituted aryl group or optionally at least 2 groups of R1 -R3 may combine with each other to form a ring. The photosensitive layer comprises a charge generating layer containing a phthalocyanine compound and a charge transfer layer containing the phenol compound represented by the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly, to an electrophotographic photoreceptor having excellent gas resistance, high durability, and having no deterioration in electrostatic characteristics when used repeatedly.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as Se, CdS, and ZnO have been used as photoconductive materials for electrophotographic photoreceptors. However, they have problems such as sensitivity, thermal stability, and toxicity. In recent years, electrophotographic photosensitive members using organic photoconductive materials have been actively developed, and many copiers and printers have been equipped with electrophotographic photosensitive members using organic photoconductive materials. Has reached. Generally, the electrophotographic photoreceptor used in the Carlson process is charged-
The function is achieved by repeatedly performing the processes of exposure, development, transfer, static elimination, and cleaning, but these electrophotographic photoreceptors are required to have highly durable characteristics capable of always providing good images. . this is,
The same applies to an electrophotographic photoreceptor using an organic photoconductive material, which is required to be highly durable and to have no image deterioration upon repeated use. Further, since the substance constituting the photoreceptor is an organic substance, deterioration due to gases such as ozone and NOx can be considered. Therefore, improvement in gas resistance to these gases is also required. Among them, as a method for obtaining a highly durable electrophotographic photoreceptor, conventionally, it has been proposed to provide an intermediate layer between a photosensitive layer and a support to suppress a decrease in charging potential or dark portion potential. As such an intermediate layer,
Polyamide (JP-A-46-47344, JP-A-5-47344)
JP-A-2-25638), polyesters (Japanese Unexamined Patent Publication No.
JP-A-2-20836, JP-A-54-26738), polyurethane (JP-A-49-10044, JP-A-53-89435), casein (JP-A-55-103556). ), Polyvinyl alcohol (described in JP-A-52-100240), polyvinyl pyrrolidone (JP-A-48-30936)
JP-A-57-9), polyvinyl butyral (Japanese Patent Laid-Open No. 57-9 / 1982).
No. 0639, JP-A-58-106549), vinyl acetate-ethylene copolymer (JP-A-48-2).
No. 6141), ethyl cellulose (Japanese Unexamined Patent Publication No.
It is known to use a resin such as N-methoxymethylated nylon (described in JP-A-2-108064). However, electrophotographic photoreceptors using an intermediate layer made of these materials have a problem in that the reduction of the charging potential is reduced but the residual potential is increased. On the contrary, the charging potential is reduced although the residual potential is not increased. However, there is a problem that the variation in electrostatic characteristics due to the environment becomes large, and providing an intermediate layer has not yet been sufficient. Regarding the improvement of gas resistance, Japanese Patent Application Laid-Open No.
As disclosed in JP 18355-A and the like, antioxidants (hindered phenol compounds, phosphorus compounds, sulfur compounds,
It has been proposed to add an amine compound, a hindered amine compound or the like) to the photosensitive layer. However,
These conventional antioxidants have a problem that they have a low effect on gas resistance and, even if they are effective enough, they significantly deteriorate other characteristics (sensitivity, residual potential, etc.). No satisfactory electrophotographic photoreceptor has been obtained.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member having improved gas resistance to gases such as ozone and NOx. Another object of the present invention is to provide an electrophotographic photoreceptor in which potential fluctuations such as a rise in a light portion potential and a decrease in a dark portion potential are improved even when repeatedly used.

[0004]

According to the present invention, a compound represented by the following general formula (I) is characterized in that the conventional problems of gas resistance and deterioration of electrostatic properties upon repeated use, especially gas resistance and repetition. It has been found that it is effective in satisfying the problem of residual potential increase during use, and this is used for an electrophotographic photosensitive member.

Embedded image (Wherein, R ₁ , R ₂ , and R ₃ each have a hydrogen atom, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and at least two of R ₁ , R ₂ , and R ₃
Two groups may be connected to each other to form a ring. )

That is, according to the present invention, first, in an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, the photosensitive layer contains a phenol compound represented by the following general formula (I): An electrophotographic photosensitive member is provided. According to the present invention, there is provided an electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer comprises a charge generation layer and a charge transport layer. An electrophotographic photoreceptor comprising the phenol compound represented by the formula (I) is provided. Further, according to the present invention, thirdly, there is provided an electrophotographic photosensitive member containing a phthalocyanine compound as a charge generating substance of a photosensitive layer in the first or second electrophotographic photosensitive member.

Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited to these specific examples.

[0007]

[Table 1-1]

[0008]

[Table 1-2]

[0009]

[Table 1-3]

[0010]

[Table 1-4]

In the present invention, the reason why the addition of the phenol compound of the general formula (I) makes the gas resistance and electrostatic durability extremely good is that the group adjacent to the hydroxy group is a cyclohexyl group. In addition to keeping the hindering property of the hydroxy group effective, unlike the conventional bulky alkyl group, it has excellent compatibility in the photosensitive layer and can be effectively dispersed in the photosensitive layer. It is thought that it depends.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration example of the electrophotographic photoreceptor of the present invention, and has a configuration in which at least a photosensitive layer 15 is laminated on a conductive support 11. FIG. 2 is a cross-sectional view showing another configuration example of the present invention. An intermediate layer 13 is provided between a conductive support 11 and a photosensitive layer 15. FIG. 3 and FIG. 4 are cross-sectional views showing another configuration example of the present invention, in which the photosensitive layer 15 is formed by laminating a charge generation layer 17 and a charge transport layer 19. FIG.
FIG. 4 is a cross-sectional view showing still another configuration example of the present invention, in which a protective layer 21 is provided on a photosensitive layer 15.

The phenolic compound represented by the general formula (I) according to the present invention can be contained in the photoreceptor shown in the photosensitive layer and the charge transport layer according to the constitution described in the claims.

The conductive support 11 has a volume resistance of 10
Those exhibiting a conductivity of ¹⁰ Ωcm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, metal oxides such as indium oxide, by vapor deposition or sputtering , Film or cylindrical plastic, paper coated,
Alternatively, a plate made of aluminum, an aluminum alloy, nickel, stainless steel, or the like, or a tube formed by extruding, drawing, or the like, and then surface-treated such as cutting, superfinishing, or polishing can be used. Also,
An endless nickel belt and an endless stainless belt disclosed in JP-A-52-36016 can also be used as the conductive support 11.

In addition, the above-mentioned support obtained by dispersing a conductive powder in a suitable binder resin and coating the same can also be used as the conductive support 11 of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, and metal oxide powder such as conductive titanium oxide, conductive tin oxide, and ITO. And so on. The binder resins used simultaneously include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, and vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate,
Cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin,
Thermoplastic, thermosetting or photocurable resins such as silicone resin, epoxy resin, melamine resin, urethane resin, phenolic resin, and alkyd resin. Such a conductive layer can be provided by dispersing the conductive powder and the binder resin in an appropriate solvent, for example, tetrahydrofuran, dichloromethane, 2-butanone, toluene, or the like, and applying the dispersion.

Further, a conductive material is formed on a suitable cylindrical substrate by means of a heat-shrinkable tube in which a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chloride rubber, Teflon or the like contains the above-mentioned conductive powder. Those provided with a layer can also be favorably used as the conductive support 11 of the present invention.

First, a case of a laminated structure in which at least the charge generation layer 17 and the charge transport layer 19 are laminated on the conductive support 11 will be described. The charge generation layer 17 may be formed of only a charge generation substance, or may be formed by dispersing a charge generation substance in a binder resin. Therefore, the charge generation layer 17 is obtained by dispersing these components in an appropriate solvent using a ball mill, an attritor, a sand mill, ultrasonic waves, or the like, applying the dispersion on the conductive support 11 or the intermediate layer 13, and drying the dispersion. Formed by

The charge generating substance used in the charge generating layer 17 includes azo pigments such as phthalocyanine pigments, monoazo pigments, bisazo pigments, asymmetric disazo pigments, trisazo pigments, tetraazo pigments, pyrrolopyrrole pigments, anthraquinone pigments, perylene pigments, and the like. Polycyclic quinone pigments, indigo pigments, squarium pigments, pyrene pigments, diphenylmethane pigments, azine pigments, quinoline pigments, perinone pigments, and other known materials can be used, but in the present invention, phthalocyanine pigments are used. The effect becomes remarkable by using.

Examples of the phthalocyanine pigments include metal-free phthalocyanines (X type, τ type, etc.), titanyl phthalocyanine, vanadyl phthalocyanine, copper phthalocyanine, hydroxygallium phthalocyanine, fluorogallium phthalocyanine, dichlorotin phthalocyanine, chloroaluminum phthalocyanine, chloroindium phthalocyanine, For example, a known material can be used.

The reason why phthalocyanine pigments are preferably used is that the phenolic compound of the present invention added to the photosensitive layer fills traps on the pigment surface with respect to phthalocyanine pigments, which generally have low resistance. It is considered that by increasing the apparent resistance, the photosensitive layer is increased in resistance and durability without adverse effects such as sensitivity deterioration.

The binder resin used for the charge generation layer 17 includes polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal,
Polyvinyl ketone, polystyrene, poly-vinyl carbazole, polyacrylamide, polyvinyl benzal,
Examples include polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone and the like.

The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight, per 100 parts by weight of the charge generating substance. The thickness of the charge generation layer is 0.01
To 5 μm, preferably 0.1 to 2 μm. Solvents used here include isopropanol, acetone,
Methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate,
Methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene,
Ligroin and the like. As a method of applying the coating liquid,
Methods such as dip coating, splat coating, bead coating, nozzle coating, spinner coating, and ring coating can be used.

The charge transport layer 19 is formed by dissolving or dispersing a charge transport material, a binder resin, and a phenol compound represented by the general formula (I) of the present invention in a suitable solvent, and coating the solution on the charge generation layer. And can be formed by drying.
If necessary, a plasticizer, a leveling agent, an antioxidant and the like can be added.

The charge transport material includes a hole transport material and an electron transport material. Examples of the electron transporting substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Electron accepting substances such as trinitro-4H-isodeno [1,2-b] titophene-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and benzoquinone derivatives. Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof,
γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative,
Diarylamine derivatives, triarylamine derivatives,
Stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, Known materials such as enamine derivatives and other polymerized hole transporting substances are exemplified. These charge transport materials are used alone or in combination of two or more. As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl polyacetate, Polyvinylidene chloride, polyarylate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, Phenol resin, alkyd resin, JP-A-5-1
And thermoplastic or thermosetting resins such as various polycarbonate copolymers described in JP-A-58250 and JP-A-6-51544. The amount of the charge transporting substance is the binder resin 1.
20 to 300 parts by weight, preferably 4 parts by weight, per 100 parts by weight
0 to 150 parts by weight is suitable. Further, the thickness of the charge transport layer is preferably about 5 to 50 μm.

As the solvent used here, tetrahydrofuran, dioxane, toluene, monochlorobenzene, dichloroethane, dichloromethane, cyclohexanone, methyl ethyl ketone, acetone and the like are used.
In the present invention, a leveling agent and an antioxidant may be added to the charge transport layer 19. As the leveling agent, silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in a side chain can be used. ~
One part by weight is suitable. Examples of the antioxidant include a hindered phenol compound, a sulfur compound, a phosphorus compound, a hindered amine compound, a pyridine derivative, a piperidine derivative, and a morpholine derivative. Can be used in combination with 0 to 5 parts by weight based on 100 parts by weight of the binder resin.
A suitable amount is about parts by weight.

Next, a case where the photosensitive layer 15 has a single-layer structure will be described. Also in this case, in many cases, a function-separated type material containing a charge generating substance and a charge transporting substance is exemplified. That is, the compounds exemplified above can be used as the charge generating substance and the charge transporting substance.

The photosensitive layer having a single layer structure is prepared by dissolving or dispersing a charge generating substance, a charge transporting substance, a binder resin and the phenol compound of the formula (I) shown in the present invention in a suitable solvent, and coating the same. Can be formed by drying. If necessary, a leveling agent, an antioxidant and the like can be added. As the binder resin, first, the charge transport layer 19 is used.
Can be used, but the binder resin exemplified for the charge generation layer 17 may be mixed and used. The photosensitive layer having a single-layer structure is a coating liquid obtained by dispersing a charge generating substance, a charge transport substance, a binder resin, and the like with a dispersing machine or the like using a solvent such as tetrahydrofuran, dioxane, dichloroethane, cyclohexanone, or dichloromethane, using a dip coating method or the like. It can be formed by coating with a method such as spray coating or bead coating. The thickness of the photosensitive layer having a single-layer structure is suitably about 5 to 50 μm.

In the present invention, an intermediate layer 13 can be provided between the conductive support 11 and the photosensitive layer 15 as shown in FIG. The intermediate layer 13 may be made of a material containing a resin as a main component or a material obtained by adding a fine powder pigment such as a metal oxide to a resin. Considering that the photosensitive layer 15 is coated on the intermediate layer 13 with a solvent, these resins are preferably resins having high solvent resistance to general organic solvents.
Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate, alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, ethylene-vinyl acetate copolymer, and ethylene-vinyl acetate-anhydrous. Ethylene resins such as maleic acid copolymer, ethylene-vinyl acetate-methacrylic acid copolymer,
Vinyl chloride resins such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer,
Cellulose derivative resin, polyurethane, melamine resin,
Curable resins that form a three-dimensional network structure, such as phenol resins, alkyd-melamine resins, acryl-melanin resins, silicone resins, silicone-alkyd resins, epoxy resins, and polyisocyanate compounds. The intermediate layer 13 may be added with a fine powder pigment of a metal oxide such as titanium oxide, aluminum oxide, silica, zirconium oxide, tin oxide, and indium oxide to prevent moiré and reduce residual potential. Further, as the intermediate layer 13 of the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, a titanyl chelate compound, a zirconium chelate compound, a titanyl alkoxide compound, and an organic titanyl compound can also be used.
These intermediate layers 13 can be formed using an appropriate solvent, dispersion, and coating method as in the above-described photosensitive layer.

In addition, the intermediate layer 13 of the present invention has
₂ O ₃ provided by anodic oxidation, organic substances such as polyparaxylylene, SiO ₂ , SnO ₂ , TiO, ITO, Ce
Those provided with an inorganic substance such as O _{2 by} forming a vacuum thin film can also be used favorably. The thickness of the intermediate layer 13 is suitably from 0 to 10 μm.

The protective layer 21 is provided for the purpose of improving the durability of the photoreceptor. The material used for this is ABS resin,
ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, Polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene,
Resins include polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin and the like. Protective layer 2
In addition, a fluorine resin such as polytetrafluoroethylene, a silicone resin, or an inorganic material such as titanium oxide, tin oxide, potassium titanate, or the like can be added to 1 for the purpose of improving abrasion resistance. As a method for forming the protective layer 21, a normal coating method can be used. In addition,
The thickness of the protective layer 21 is suitably from 0.1 to 10 μm. In addition to the above, aC, a formed by a vacuum thin film forming method
A known material such as —SiC can also be used as the protective layer 21.

In the present invention, the photosensitive layer 15 and the protective layer 21
It is also possible to provide another intermediate layer (not shown) between them. The other intermediate layer generally uses a resin as a main component. Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble butyral resin, polyvinyl bityral, and polyvinyl alcohol. As a method for forming the another intermediate layer, a normal coating method can be used as described above. The thickness is 0.05 to 2 μm.
Is appropriate.

The phenol compound represented by the general formula (I) can be contained in the photosensitive layer and the charge transport layer as described in the claims. When added to the photosensitive layer, it is preferable to add 0.2 to 5 parts by weight based on 100 parts by weight of the binder resin. When added to the charge transport layer, it is preferable to add 0.1 to 5 parts by weight based on 100 parts by weight of the charge transport material. When the added amount is less than the lower limit, the above-described effects cannot be obtained, and when the added amount is larger than the upper limit,
Although having the above-mentioned effects, electrostatic characteristics such as sensitivity are deteriorated, and the residual potential is increased by repeated use.

[0033]

Next, the present invention will be described with reference to examples.

Example 1 70 parts by weight of titanium oxide (CR-EL: manufactured by Ishihara Sangyo), 15 parts by weight of alkyd resin (Beccolite M6401-50-S (solid content: 50%): manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin (Super Beckamine L-121-60
A mixture of 10 parts by weight (solid content: 60% by Dainippon Ink and Chemicals) and 100 parts by weight of methyl ethyl ketone was dispersed in a ball mill for 72 hours to prepare a coating liquid for an intermediate layer. An aluminum plate having a thickness of 0.2 mm (Al 080:
(Manufactured by Sumitomo Light Metal Co., Ltd.) and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 3 μm. Next, a trisazo pigment 10 represented by the following structural formula (IV) is used as a charge generating substance.
4 parts by weight of polyvinyl butyral (BM-2: manufactured by Sekisui Chemical Co., Ltd.) was added to a resin solution prepared by dissolving 4 parts by weight of cyclohexanone in 150 parts by weight, and dispersed in a ball mill for 72 hours. After completion of the dispersion, 210 parts by weight of cyclohexanone was added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This was applied onto the intermediate layer and dried at 130 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Embedded image Next, 8 parts by weight of a charge transport material represented by the following structural formula (V), 10 parts by weight of polycarbonate (Iupilon Z-200: manufactured by Mitsubishi Gas Chemical Company), and silicone oil (KF-5)
0: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.002 parts by weight; 0.08 parts by weight of the compound (I) -8 was dissolved in 100 parts by weight of dichloromethane to prepare a charge transport coating solution. This was applied on the charge generation layer and dried at 130 ° C. for 15 minutes to form a charge transport layer having a thickness of 25 μm. Thus, an electrophotographic photoreceptor of Example 1 was obtained.

Embedded image

Examples 2 and 3 The compound of the general formula (I) to be added to the charge transporting layer is exemplified by Compound No. The electrophotographic photoreceptors of Examples 2 and 3 were prepared in the same manner as in Example except that (I) -3 and (I) -5 were respectively used.

Comparative Example 1 In Example 1, Exemplified Compound No. An electrophotographic photosensitive member of Comparative Example 1 was prepared in the same manner as in Example 1 except that the compound of (I) -8 was not added.

Comparative Examples 2 and 3 In Example 1, Exemplified Compound No. Example 1 except that the hindered phenol compounds of the following structural formulas (II) and (III) were added in place of the phenol compound of (I) -8.
The electrophotographic photoreceptors of Comparative Examples 2 and 3 were prepared in the same manner as described above.

Embedded image

Examples 4 to 15 and Comparative Examples 4 to 15 The charge-generating substance structural formula (IV) and the compound No. Electrophotographic photosensitive members of Examples 4 to 15 and Comparative Examples 4 to 15 were prepared in the same manner as in Example 1 except that (I) -8 was changed as shown in Table 2.

[0039]

[Table 2]

The electrophotographic photosensitive member obtained as described above was subjected to EPA-8100 under an environment of 25 ° C./50% RH.
(Kawaguchi Electric Works) was used to evaluate the electrostatic characteristics in the dynamic mode. First, the photosensitive member is negatively charged by performing a corona discharge of -4 kV for 5 seconds, and a surface potential V2 (-
V), and when the surface potential became −800 V, light (1.0 μW / cm ² ), which was dispersed at 780 nm using a band-pass filter, was exposed, and the surface potential became -4.
Exposure E1 / 2 (μJ / c) required to attenuate light to 00V
m ² ) and the surface potential V30 (−V) 30 seconds after exposure. In addition, a corona discharge of -5 kV and a color temperature of 2856 K
The exposure of the tungsten lamp 451ux was repeated in the dynamic mode for 120 minutes, and then the same measurement was performed to evaluate the electrostatic characteristics after fatigue. Further, as an evaluation of gas resistance, the obtained electrophotographic photoreceptor was subjected to NOx concentration (NO + NO ₂ ) of 50 ppm, temperature and humidity of 20 ° C./30% R.
The sample was allowed to stand in an environment of H for 3 days, and the electrostatic characteristics were evaluated in the same manner as described above, and the amounts of change in electrostatic characteristics ΔV2, ΔE1 / 2, and ΔV30 before and after NOx gas exposure were measured. Table 3 shows the results
Shown in ΔV2 = V2 (before exposure)-V2 (after exposure) ΔV30 = V30 (before exposure)-V30 (after exposure)

[0041]

[Table 3]

[0042]

As described above, the electrophotographic photoreceptor of the present invention is excellent in gas resistance, excellent in durability due to repeated use, and has a decrease in charging potential and a rise in residual potential even during repeated electrostatic fatigue. With extremely low performance and very high practical value.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a layer configuration of an electrophotographic photoreceptor of the present invention.

FIG. 2 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 4 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

FIG. 5 is a cross-sectional view illustrating a layer configuration of the electrophotographic photosensitive member of the present invention.

Claims (3)

[Claims] 1. An electrophotographic photosensitive member having at least a photosensitive layer on a conductive support, wherein the photosensitive layer contains a phenolic compound represented by the following general formula (I). . Embedded image In the formula, R ₁ , R ₂ , and R ₃ each have a hydrogen atom, a hydroxy group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and at least two of R ₁ , R ₂ , and R ₃ The groups may be connected to each other to form a ring. 2. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer comprises a charge generation layer and a charge transport layer, and the charge transport layer contains the phenol compound represented by the general formula (I). . 3. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains a phthalocyanine compound as a charge generating substance.