JP2000162796A - Positive charge electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sensitivity and fatigue deteriorations of a photoreceptor by incorporating a specified charge producing material, hole transfer material and electron transfer material. SOLUTION: The charge producing layer contains a charge producing material expressed by formula I or the like, a hole transfer material expressed by formula II and electron transfer material expressed by formula III. In formula II, R is a halogen atom or the like, each of R1 and R2 is a hydrogen atom or the like, l, m, n are integers 0 to 5. In formula III, =Q represents =o, =C(CN)2, =N(CN), =C(X)Y, wherein X, Y are hydrogen atoms, halogen atoms, cyano groups or the like, R1 is an alkyl group or aryl group, R is an aryl group, Z is a halogen atom, nitro group or the like, CF3, COR1, COOR1, CONHR1, SOR1, SO2R1 or OCOR1, m is 0 or positive integer, n is a positive integer and the sum of m and n is an integer 1 to 8. When Q is N(CN), n is an integer >2, an groups represented by Z, R, Q may be same or different from one another.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positively charged electrophotographic photosensitive member, and more particularly, to a positively charged electrophotographic photosensitive member useful for a printer, a copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic photoreceptor (hereinafter, also simply referred to as a photoreceptor), an inorganic photoreceptor having a photosensitive layer mainly composed of an inorganic photoconductive substance such as selenium, zinc oxide, cadmium sulfide, and silicon. Has been widely used. However, these are not always satisfactory in sensitivity, thermal stability, moisture resistance, durability, and the like, and some inorganic photoreceptors contain substances harmful to the human body, and thus have a problem of environmental pollution upon disposal. .

In order to overcome the disadvantages of these inorganic photoreceptors, research and development of organic photoreceptors having a photosensitive layer containing various organic photoconductive materials as main components have been actively conducted in recent years. In particular, the function-separated type photoconductor in which the charge generation function is assigned to the charge generation material (CGM) and the charge transport function is assigned to the charge transport material (CTM) can be selected from a wide range of materials. Since it is relatively easy to produce a material having the above-mentioned performance, much research and development has been carried out, and it has been widely put to practical use.

In the above-mentioned function-separated type photoreceptor, a charge generation layer (CG) containing CGM is formed on a conductive substrate.
L), and a hole transport material (p-CTM) on the CGL.
The mainstream is a negatively charged photoreceptor having a layered structure provided with a charge transport layer (CTL) containing. However, in the above negatively charging photoreceptor in conferring uniformly charged the surface, there is a disadvantage exacerbates the environmental conditions and generate a large amount of ozone and NO _X.

[0005] Therefore, a photoreceptor for friendly positively charged less environment generation of ozone and NO _X are attracting attention. As the photoconductor for positive charging, CGM and p-
A photoreceptor having a single-layered photoconductive layer containing both CTMs or a photoreceptor having a laminated structure in which a CTL containing p-CTM is provided on a conductive substrate and a CGL containing CGM is provided on the CTL. Was used.

[0006] However, all of the above positively charged photoreceptors have a p-type electron-hole pair generated during light irradiation.
The CTM is transported to the conductive support by the hole transport function and is discharged. However, since the electron transfer that cancels the positive charge on the surface of the photoconductor is not sufficient, the sensitivity of the photoconductor is low and the photoconductor is used repeatedly. In this case, the sensitivity was further lowered and the fatigue was deteriorated, resulting in poor practicality.

Accordingly, in order to obtain a highly sensitive and highly durable photoconductor for positive charging, p-CTM is required together with CGM in the photosensitive layer.
And an electron transport material (n-CTM).

Therefore, for example, Japanese Patent Application Laid-Open No. 2-42449 (Patent Document 1) discloses a CGL containing an N-cyanoimine compound as n-CTM on a conventionally known CGM such as a CGL containing a bisazo compound or a phthalocyanine compound.
A stacked positive charging photoconductor provided with a TL is described. In addition, the above publication discloses that NGM is contained in the photosensitive layer containing CGM.
-A single-layer type positive-charging photoconductor containing a cyanoimine compound as a sensitizer has also been proposed. Japanese Patent Application Laid-Open No. 5-45908 (publication 2) discloses a known CGM,
For example, in a photosensitive layer containing a bisazo compound, a phthalocyanine compound or the like, n-CTM is p-benzoquinone and p-CTM is, for example, a butadiene compound, a benzidine compound, a diamine compound, a hydrazone compound or a p-toluylamino-stilbene compound. A single-layer type positive charging photoconductor containing a compound has been proposed.

[0009]

However, the lamination type photoreceptor disclosed in the above publication 1 has insufficient transportability of electrons generated during light irradiation to the surface layer and transportability of holes to the support side. It has low sensitivity, and the photoreceptor is further fatigue-deteriorated in the course of repeated image formation, resulting in problems such as insufficient image density, a large amount of fog, and the inability to obtain a clear image.

The single-layer type photoreceptor disclosed in the above publication 2 has n-CTM and p-CTM together with CGM in the photosensitive layer, but the combination of CGM, n-CTM and p-CTM is appropriate. Therefore, the transportability of electron and hole pairs generated at the time of light irradiation is also poor, the sensitivity is low, the sensitivity of the photoreceptor decreases and the fatigue deteriorates in the process of repeated charging and exposure, and the image density during image formation Is insufficient, and a problem such that a clear image cannot be obtained due to a large amount of fogging occurs.

As a result of intensive studies, the present inventors have found that practically sufficient sensitivity can be obtained by excellent selection and combination of CGM contained in the photosensitive layer and p-CTM and n-CTM,
The present inventors have found a positively charged photoreceptor capable of stably obtaining a high-density and clear image without causing a reduction in sensitivity or fatigue deterioration of the photoreceptor due to repeated charging and exposure, and completed the present invention.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned circumstances, and has as its object the advantage that when used repeatedly for image formation, the sensitivity of the photoreceptor does not decrease and the fatigue deterioration does not occur, and the high-density clear image is obtained. An object of the present invention is to provide a positively charged photoreceptor capable of stably obtaining an image.

[0013]

The above object is achieved by the following constitution.

1. An electrophotographic photosensitive member for positive charging comprising a photosensitive layer provided on a conductive support, wherein the photosensitive layer has a layered structure in which a charge transport layer for hole transport and a charge generating layer are provided in this order on the conductive support. A charge-generating material represented by the following structural formula (A):
Alternatively, a charge generation material represented by the following structural formula (B), a hole transport material represented by the following general formula (1), and a following general formula (2)
An electrophotographic photoreceptor for positive charging, comprising an electron transporting material represented by the formula:

[0015]

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[0016]

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In the formula, R represents a halogen atom, an alkyl group or an alkoxy group, R ₁ and R ₂ represent a hydrogen atom or a substituted or unsubstituted aryl group, and l, m and n each represent an integer of 0-5.

[0018]

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In the formula, = Q is = O, = C (CN) ₂ , = N
(CN), = C (X) Y. Here, X and Y are a hydrogen atom, a halogen atom, a cyano group, an aryl group, COO
R ₁ and COR ₁ represent each group. R ₁ represents an alkyl group or an aryl group, and R represents an aryl group. Z is a halogen atom, a nitro group, a cyano group, CF ₃ , COR _1, COOR _1,
Represents CONHR ₁ , SOR ₁ , SO ₂ R ₁ or OCOR ₁ .

M represents 0 or a positive integer, and n represents a positive integer. The sum of m and n represents an integer of 1 to 8. However,
When Q is N (CN), n is an integer of 2 or more. Z,
The groups represented by R and Q may be the same or different.

2. In an electrophotographic photosensitive member for positive charging comprising a photosensitive layer provided on a conductive support, the photosensitive layer may be at least a charge-generating substance represented by the structural formula (A) and / or a photosensitive material represented by the structural formula (B). Characterized in that the photosensitive layer has a single-layer structure containing a charge generation material, a hole transport material represented by the general formula (1), and an electron transport material represented by the general formula (2). Electrophotographic photoreceptor for positive charging.

Hereinafter, the present invention will be described in detail.

The positively charged photoreceptor of the present invention is provided with a hole transporting CTL on a conductive support.
Above, a polycyclic quinone compound (CGM) represented by the structural formula (A) and / or a perylene compound represented by the structural formula (B) as CGM, and a styryl represented by the general formula (1) as p-CTM A photoreceptor (Invention 1 (Claim 1)) having a laminated photosensitive layer obtained by providing a CGL containing a triphenylamine-based compound and a compound represented by the general formula (2) as n-CTM is provided. And the above-mentioned structural formula (A) as CGM on a conductive support
And / or a perylene compound represented by the structural formula (B), and p-CTM
A single-layer photosensitive layer obtained by providing a photosensitive layer containing a styryltriphenylamine-based compound represented by the general formula (1) and a compound represented by the general formula (2) as n-CTM (Invention 2 (Claim 2)).

<Explanation of General Formula (1)> In the CGL of the photoreceptor having a laminated structure and the p-CTM of the general formula (1) contained in the photosensitive layer of the photoreceptor having a single layer structure according to the present invention, R represents a halogen atom, a lower alkyl group or an alkoxy group having 5 or less carbon atoms, and R ₁ and R ₂ represent a hydrogen atom or an aryl group such as a substituted or unsubstituted phenyl group or a naphthyl group. Examples of the group include a halogen atom, a lower alkyl group or an alkoxy group having 5 or less carbon atoms,
L, m, and n represent an integer of 0 to 5.

Preferred examples of the styryltriphenylamine-based compound represented by the general formula (1) include the following.

[0026]

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[0027]

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<Explanation of General Formula (2)> Further, in the CGL of the photoreceptor having a laminated structure and the n-CTM of the general formula (2) contained in the photosensitive layer of the photoreceptor having a single layer structure according to the present invention,
= Q in the formula is = O, = C (CN) ₂ , = N (CN), =
Represents C (X) Y. Here, X and Y represent a hydrogen atom, a halogen atom, a cyano group, an aryl group, COOR ₁ , and COR ₁ groups. R ₁ represents an alkyl group or an aryl group;
Represents an aryl group. Z is a halogen atom, a nitro group, a cyano group, CF ₃ , COR _1, COOR _1, CONHR ₁ , SO
Represents R ₁ , SO ₂ R ₁ or OCOR ₁ .

M represents 0 or a positive integer, and n represents a positive integer. The sum of m and n represents an integer of 1 to 8. However,
When Q is N (CN), n is an integer of 2 or more. Z,
The groups represented by R and Q may be the same or different.

In the present invention, the aryl group preferably represents a substituted or unsubstituted phenyl group, and the substituent is preferably a halogen atom, an alkyl group, an acyl group,
Represents an ester group, cyano group, nitro group, methyl fluoride group or methoxy group.

Preferred examples of the compound represented by formula (2) include the following.

[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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<Structure of Photoconductor of Each Invention> FIG. 1 is a sectional view for explaining the layer structure of the photoconductor of the present invention.
1 (a), 1 (c), 1 (e), and 1 (g) are cross-sectional configuration diagrams of a photoconductor having a laminated configuration, and FIGS.
(D), FIG. 1 (f), and FIG. 1 (h) are cross-sectional configuration diagrams of a photoconductor having a single-layer configuration. In FIG. 1A to FIG.
Is a conductive support, 2 is a photosensitive layer, 3 and 4 are CGLs and hole transport CTLs of a laminated photosensitive body, and 5 is provided between the conductive support 1 and the photosensitive layer 2 as necessary. It is an intermediate layer. 6 and 7 are the CGM of the structural formula (A) and the CGM of the structural formula (B), 8 is the p-CTM of the general formula (1), and 9 is the n-CTM of the general formula (2). Represent. Note that a protective layer can be further provided on the outermost surface layer.

FIG. 2 is an explanatory diagram of the photoconductive characteristics of the photoconductor having the above-mentioned laminated structure. When the CGM 6 (7) of the CGL 3 is irradiated with light 10, electrons 11 and holes 12 are generated. As (7), those having a function of transporting electrons 11 are selected, and n-CTM9 of the general formula (2) has an action of promoting the transport function of the CGM6 (7) for electrons 11, so that It is quickly transported to cancel the surface charge 13, and the hole 12 is formed by the p-CTM of the general formula (1).
By the hole transporting function 8 and the function of the hole transporting CTL 4, the material is quickly transported to the conductive support 1 and discharged.

FIG. 3 is an explanatory view of the photoconductive property of the photosensitive member having a single layer structure. When the CGM 6 (7) of the photosensitive layer 2 is irradiated with light 10, electrons 11 and holes 12 are generated. 11
Is the electron transport function of CGM6 (7) and the general formula (2)
Is rapidly transported by the electron transport promoting function of n-CTM9 to cancel the surface charge 13, and the holes 12 are transported to the conductive support 1 by the hole transport function of p-CTM8 of the general formula (1) and discharged. You. 2 and 3, the transport of the electrons 11 and the holes 12 is based on the CGM specific to the present invention, p-CTM8 of the general formula (1) and n-CT of the general formula (2).
The combination of excellent combinations of M9 is performed at high speed and smoothly.

As described above, the CGM6 of the photoreceptor of the present invention
(7) has a function of transporting the electrons 11 and, despite the fact that the photosensitive layer contains p-CTM8 having a hole transporting function, injects positive charges on the surface of the photoreceptor into the photosensitive layer. Since a material having an action of inhibiting the photoreceptor is selected, the sensitivity of the photoreceptor is not reduced due to the injection of the positive surface charge into the photosensitive layer and the fatigue deterioration is small in the process of repeated charging and exposure. A clear image can be obtained stably. Note that the photoconductor having the layered configuration of FIG. 1 has the CTL for transporting holes, so that the holes are transported to the conductive support at the time of light irradiation and grounded as compared with the photoconductor of the single-layer configuration shown in FIG. It is easy to obtain a high-density and clear image at the time of image formation.

<Processing and Composition of Photoreceptor of Each Invention> In the formation of the CGL 3 of the photoreceptor having the above-mentioned laminated structure or the photosensitive layer 2 of the photoreceptor having the single-layered structure, CGM6 (7), p-CTM8,
It is effective to apply a solution in which n-CTM9 is dissolved in a solvent together with a binder resin and additives as necessary. However, in the CGL 3 or the photosensitive layer 2,
In general, since CGM6 (7) has low solubility in a solvent, a dispersion in which the CGM6 (7) is finely dispersed in a suitable dispersion medium using a dispersing apparatus such as an ultrasonic dispersing machine, a ball mill, a sand mill, and a homomixer. The above p-CTM8, nC
TM9, a binder resin and other additives dissolved therein are used as a coating solution and processed by a coating method such as bar coating, spin coating, applicator coating, spray coating, dip coating, or coating with a slide hopper type coating device. can get. In the formation of the hole transporting CTL 4 having the above-mentioned laminated structure, the well-known hole transporting C
A solution obtained by dissolving TM in a solvent together with a binder resin is applied by the above-mentioned application method.

The CTM contained in the hole transporting CTL 4 as the lower layer of the photoreceptor having the above-mentioned laminated structure includes, for example, a nitrogen-containing heterocyclic nucleus represented by oxazole, oxadiazole, thiazole, thiadiazole, imidazole and the like. A compound having the fused ring nucleus, a polyarylalkane compound, a pyrazoline compound, a hydrazone compound, a triarylamine compound, a styryl compound,
Examples include styryltriphenylamine-based compounds, β-phenylstyryltriphenylamine-based compounds, benzidine-based compounds, butadiene-based compounds, hexatriene-based compounds, carbazole-based compounds, and condensed polycyclic compounds.

If necessary, various n-CTs containing the above-mentioned general formula (2) may be contained in the lower layer CTL4 of the laminated photosensitive layer of the present invention.
M may be contained.

As the solvent or dispersion medium used for forming the photosensitive layer 2 having the above-mentioned laminated structure or single-layer structure, any of a wide variety of solvents can be used. For example, butylamine, ethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone,
Cyclohexanone, tetrahydrofuran, dioxane,
Examples include dioxolan, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, toluene, xylene, acetophenone, chloroform, dichloromethane, dichloroethane, trichloroethane, methanol, ethanol, propanol, and butanol.

Any binder resin can be selected as the binder resin used for forming the photosensitive layer 2 having the above-mentioned laminated structure or single-layer structure. Particularly, a high-molecular polymer resin having hydrophobicity and film-forming ability can be used. Is desirable. Examples of such a polymer resin include the following, but are not limited thereto. Polycarbonate (particularly preferred is bisphenol Z-type polycarbonate resin), acrylic resin, methacrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene
Butadiene copolymer resin, polyvinyl acetate, polyvinyl formal, polyvinyl butyral, polyvinyl acetal, polyvinyl carbazole, styrene-alkyd resin, silicone resin, silicone-alkyd resin,
Polyester, phenolic resin, polyurethane, epoxy resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin.

In the photoreceptor having the laminated structure shown in FIGS. 1A, 1C, 1E, and 1G, the binder resin in CGL3, CGM6 (7), p-CTM8, n -C
The content ratio of TM9 is 5 to 100 parts by weight of CGM6 (7) per 100 parts by weight of binder resin, and p-CTM8
10 to 150 parts by weight and 0.1 to 30 parts of n-CTM9.
Parts by weight, and the hole transporting CTL4
The content ratio of the binder resin and the CTM for hole transport in the resin was 2 parts per 100 parts by weight of the binder resin.
It is preferably from 0 to 200 parts by weight. FIG.
(B), the binder resin in the photosensitive layer 2 having a single-layer structure shown in FIGS. 1 (d), 1 (f), and 1 (h), CGM6 (7), p
-The content ratio of CTM8 and n-CTM9 is 5 to 100 parts by weight of CGM6 (7), 1 to 30 parts by weight of n-CTM9 and p-CTM8 per 100 parts by weight of the binder resin.
Is preferably 10 to 150 parts by weight.

In the photoreceptor of the present invention, FIG.
(E), the photoreceptor having the laminated structure of FIG.
(F) A mixed CGM of the CGM6 of the structural formula (A) and the CGM7 of the structural formula (B) may be used as in the single-layer photoconductor of FIG. As a mixing ratio, CGM7 is 10% by weight based on the total amount of CGM.
The following is preferable because CGM6 and CGM7 have different color sensitivities, and CGM6 alone is suitable for a copier that requires only the visible range sensitivity, such as an analog copier. Since CGM7 alone has sensitivity up to the long wavelength range, it is suitable for copiers and other printers using a visible laser as a light source, which is currently under development. However, the above CGM6 contains CGM7 in a mixing ratio of 10% or less. By doing so, in the case of an analog copying machine or the like mainly using CGM 6, high sensitivity can be achieved while maintaining the reproducibility of the red region.

FIG. 1A, FIG. 1C, FIG.
The thickness of the CGL 3 of the photosensitive layer 2 having the laminated structure of FIG.
The thickness of CTL4 is preferably 5 to 30 μm. 1 (b), 1 (d), 1 (f),
The thickness of the photosensitive layer 2 having a single-layer structure shown in FIG.
m is preferred. In addition, the thickness of the intermediate layer 5 is preferably set to 0.1.
1 to 5 μm.

The photosensitive layer 2 having a laminated structure or a single-layer structure may contain a deterioration preventing agent such as an antioxidant or a light stabilizer for the purpose of improving storage stability, durability and environmental dependency. Can be. Compounds used for such purposes include, for example, chromal derivatives such as tocopherol and their etherified or esterified compounds, polyarylalkane compounds, hydroquinone derivatives and their mono- and dietherified compounds, benzophenone derivatives, benzotriazole derivatives, thioethers Compound,
Phosphonic acid esters, phosphites, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds, cyclic amine compounds, hindered amine compounds, and the like are effective. Specific examples of particularly effective compounds include “Sanol LS-2626”,
Hindered amine compounds such as “Sanol LS-622LD” (manufactured by Sankyo) and “IRGANOX 101”
0, "IRGANOX 565" (manufactured by Ciba-Geigy), "Sumilyzer BHT", "Sumilyser MDP" (manufactured by Sumitomo Chemical Co., Ltd.) and the like, or a derivative thereof (an antioxidant described later) (A-2) is included).

As the binder resin used for the intermediate layer 5 and the optional protective layer, those mentioned above for the photosensitive layer 2 can be used. In addition, polyamide resins, nylon resins, ethylene-acetic acid Ethylene resins such as vinyl copolymer resin, ethylene-vinyl acetate-maleic anhydride copolymer resin, ethylene-vinyl acetate-methacrylic acid copolymer resin, polyvinyl alcohol, and cellulose derivatives are effective. Further, a thermosetting or chemically curable binder resin such as a melamine resin, an epoxy resin, and an isocyanate resin can be used.

As the conductive support, a metal plate or a metal drum is used, and a thin layer of a conductive compound such as a conductive polymer or indium oxide, or a metal such as aluminum or palladium is applied, vapor-deposited or laminated. What is provided on a substrate such as paper or a plastic film by means can be used.

[0057]

In the following description of Examples and Comparative Examples, the CGM of the structural formula (A) will be referred to as CGM (A) and the structural formula (B)
Will be described as CGM (B).

Examples 1-1 to 1-8, Comparative Examples 1-1 to 1
-5 <Preparation of Photoreceptor 1> First, on a aluminum drum having a diameter of 80 mm, a copolymer of vinyl chloride / vinyl acetate / maleic anhydride “ESREC MF-10” (manufactured by Sekisui Chemical Co., Ltd.) was prepared using 2-butanone and cyclohexanone. A coating solution formed by dissolving in a mixed solution of the above was dip-coated to form a 0.1 μm thick intermediate layer (adhesive layer). Next, on the above-mentioned intermediate layer, in a solution prepared by dissolving 150 g of polycarbonate "Iupilon Z300" (manufactured by Mitsubishi Engineering-Plastics Corporation) in 1 liter of 1,2-dichloroethane, a compound example (P- 2) A coating solution prepared by dissolving 110 g and 5.5 g of the following compound (A-2) as an antioxidant was dried using a slide hopper coating apparatus to a film thickness of 17 μm.
Was applied to obtain CTL.

Next, 12.5 g of sublimated purified 4,10-dibromoanthanethrone (CGM (A)) was placed in 450 ml of 1,2-dichloroethane in polycarbonate "UPIRON Z-300" (manufactured by Mitsubishi Engineering-Plastics Corporation). 50) A solution in which 50 g was dissolved was wet-pulverized and dispersed using a sand mill, and 37.5 g of Compound Example (P-1) as p-CTM and Compound Example (N-1) as n-CTM were added to the dispersion. CGL obtained by dissolving 875 g and 3.75 g of the following compound (A-1) as an antioxidant
Was applied to a thickness of 13 μm using a slide hopper coating apparatus to obtain a photoreceptor 1 (for Example 1-1).

[0060]

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<Preparation of Photoreceptors 2 to 5> Compound examples (N-6) and (N-1) in place of compound example (N-1) of photoreceptor 1
2), (N-30), and (N-38), except that photoconductors 2 to 5 (Examples 1-2 to 1) were used in the same manner as photoconductor 1.
-5).

<Preparation of Photoconductor 6> Photoconductor 6 was prepared in the same manner as photoconductor 1 except that compound example (P-2) was used instead of compound example (P-1) of photoconductor 1. (For example 1-6)
I got

<Preparation of Photoconductor 7> CGM of Photoconductor 1
Photoconductor 7 (for Examples 1-7) was obtained in the same manner as photoconductor 1 except that CGM (B) was used instead of (A).

<Preparation of Photoconductor 8> CGM of Photoconductor 1
9: 1 CGM (A) and CGM (B) instead of (A)
The photoreceptor 8 (for Examples 1-8) was obtained in the same manner as in the case of the photoreceptor 1 except that the photoreceptor 1 was mixed and used.

<Preparation of Photoconductor 9> Photoconductor 9 was prepared in the same manner as photoconductor 1 except that compound example (N-1) of photoconductor 1 was omitted.
(For Comparative Example 1-1) was obtained.

<Preparation of Photoconductor 10> Photoconductor 10 (Comparative Example 1-2) was prepared in the same manner as photoconductor 1 except that compound (N-0) was used instead of compound example (N-1) of photoconductor 1. For) obtained.

<Preparation of Photoconductor 11> Photoconductor 11 (Comparative Examples 1-3) was prepared in the same manner as photoconductor 1 except that compound (P-0) was used instead of compound example (P-1) of photoconductor 1. For) obtained.

<Preparation of Photoconductor 12> CGM of Photoconductor 1
Photoconductor 12 (for Comparative Examples 1-4) was obtained in the same manner as photoconductor 1, except that x-type phthalocyanine was used instead of (A).

<Preparation of Photoconductor 13> CGM of Photoconductor 1
Photoconductor 13 (for Comparative Examples 1-5) except that bisazo compound (1) was used in place of (A) in the same manner as photoconductor 1
I got

The compound (N-
0), compound (P-0) and bisazo compound (1) are shown below.

[0071]

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<Evaluation of Electrostatic Characteristics (Sensitivity and Potential)> The photoconductors 1 to 13 were modified from Konica U-BIX 3135 (the charging device and the transfer device were set to have positive polarity, and the exhaust port was closed to reduce exhaust air). Cut, and image exposure of 630 nm or more were cut in order) to measure the sensitivity E of 13 types of photoreceptors and charge exposure over 20 kilocycles (kc) in a low-temperature and low-humidity (10 ° C., RH 30%) environment. The surface potential changes (black paper potential Vb, white paper potential Vw at start, black paper potential Vb and white paper potential Vw after 20 kc) at the time of forced deterioration due to the repetition of are measured, and the results are shown in Table 1.
It was shown to.

[0073]

[Table 1]

As shown in Table 1, the photosensitive members of the examples have excellent sensitivity and potential characteristics such as white paper potential (Vw) and black paper potential (Vb) in the course of repetition of charging and exposure. It can be seen that the sensitivity and / or potential characteristics of the sample were poor, the fatigue deterioration was large, and the practicability was poor.

Examples 2-1 to 2-4, Comparative Examples 2-1 to 2
-4 <Preparation of Photoreceptor 14> An intermediate layer (adhesive layer) having a thickness of 0.1 μm was formed on an aluminum drum having a diameter of 80 mm in the same manner as in the case of Photoreceptor 1 used in Example 1-1. Next, a photosensitive layer having the same structure as that of the CGL of the photosensitive member 1 used in Example 1-1, but having a thickness of 25 μm, is applied on the intermediate layer using a slide hopper coating device, and is formed into a single-layer photosensitive member. 14 (for Example 2-1) was obtained.

<Preparation of Photoconductor 15> Compound Example (P-6) was used instead of Compound Example (P-1) of Photoconductor 14, and Compound Example (N-30) was used instead of Compound Example (N-1). ) Except that photoreceptor 15 (Example 2-2) was used.
For) obtained.

<Preparation of Photoconductor 16> CGM of Photoconductor 14
Photoconductor 16 (for Example 2-3) was obtained in the same manner as photoconductor 14, except that CGM (B) was used instead of (A).

<Preparation of Photoconductor 17> CGM of Photoconductor 14
9: 1 CGM (A) and CGM (B) instead of (A)
The photoreceptor 17 (for Example 2-4) was obtained in the same manner as the photoreceptor 14 except that the mixture at a weight ratio of was used.

<Preparation of Photoconductor 18> Photoconductor 18 (for Comparative Example 2-1) was obtained in the same manner as photoconductor 14 except that Compound Example (N-1) of Photoconductor 14 was omitted.

<Preparation of Photoconductor 19> Photoconductor 19 (Comparative Example 2) was prepared in the same manner as photoconductor 14 except that compound (N-0) was used instead of compound example (N-1) of photoconductor 14. -2
For) obtained.

<Preparation of Photoconductor 20> Photoconductor 20 (Comparative Example 2) was prepared in the same manner as photoconductor 14 except that compound (P-0) was used instead of compound example (P-1) of photoconductor 14. -3
For) obtained.

<Preparation of Photoconductor 21> CGM of Photoconductor 14
Photoconductor 21 (for Comparative Examples 2-4) except that bisazo compound (1) was used in place of (A) and photoconductor 14 was used.
I got

<Evaluation of Electrostatic Characteristics (Sensitivity and Potential)> The photoconductors 14 to 21 having the single-layer structure were replaced with Konica U-BIX.
3135 remodeling machine (charging device and transfer device are made positive polarity, exhaust air is closed and exhaust air is cut off, and image exposure 630
of the eight types of photoreceptors and low temperature and low humidity (10 ° C., RH 30%)
Changes in surface potential when forcedly degraded due to repeated charge exposure over 20 kilocycles (kc) under an environment (black paper potential Vb at start, white paper potential Vw, 20k
c) Black paper potential Vb and white paper potential Vw) were measured, and the results are shown in Table 2.

Incidentally, the exposure amount when measuring the blank paper potential Vw (V) in the forced deterioration test of Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-4 of Table 2 is as follows. The power supply voltage of the light source was adjusted in consideration of the difference in sensitivity between the photoconductor having the laminated structure and the photoconductor having the single-layer structure shown in Table 2 to adjust the power supply voltage of the light source.
The exposure amount was 1.6 times the exposure amount in the case of Comparative Examples 1-1 to 1-8 and Comparative Examples 1-1 to 1-5.

[0085]

[Table 2]

According to Table 2, all of the photoconductors 14 to 17 of the examples have excellent sensitivity and potential characteristics such as white paper potential (Vw) and black paper potential (Vb) in the process of repeated charging and exposure of the photoconductor. However, it can be seen that the photoconductors 18 to 21 of the comparative examples have poor sensitivity and / or potential characteristics of the photoconductors, large fatigue deterioration, and poor practicability.

[0087]

As demonstrated by the examples, according to the photoreceptor of the present invention, when repeatedly used for forming an image, there is no decrease in sensitivity and no potential deterioration, and there is no image fogging or image density decrease. It has excellent effects such as a clear image being stably obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram illustrating a layer configuration of a photoconductor.

FIG. 2 is an explanatory diagram of a photoconductive characteristic of a photoconductor having a laminated structure.

FIG. 3 is an explanatory diagram of a photoconductive property of a photoconductor having a single-layer structure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 photosensitive layer 3 CGL 4 CTL 5 intermediate layer 6,7 CGM 8 p-CTM 9 n-CTM

Claims (2)

[Claims] 1. An electrophotographic photosensitive member for positive charging comprising a photosensitive layer provided on a conductive support, wherein the photosensitive layer comprises a charge transporting layer for hole transport and a charge generating layer on the conductive support in this order. Wherein the charge generating layer has at least a charge generating material represented by the following structural formula (A) and / or a charge generating material represented by the following structural formula (B): An electrophotographic photoreceptor for positive charging, comprising a hole transporting material represented by the formula (1) and an electron transporting material represented by the following general formula (2). Embedded image Embedded image In the formula, R represents a halogen atom, an alkyl group or an alkoxy group, R ₁ and R ₂ represent a hydrogen atom or a substituted or unsubstituted aryl group, and l, m and n each represent an integer of 0-5. Embedded image Where = Q is = O, = C (CN) ₂ , = N (CN), =
Represents C (X) Y. Here, X and Y represent a hydrogen atom, a halogen atom, a cyano group, an aryl group, COOR ₁ , and COR ₁ groups. R ₁ represents an alkyl group or an aryl group;
Represents an aryl group. Z is a halogen atom, a nitro group, a cyano group, CF ₃ , COR _1, COOR _1, CONHR ₁ , SO
Represents R ₁ , SO ₂ R ₁ or OCOR ₁ . m represents 0 or a positive integer, and n represents a positive integer. The sum of m and n represents an integer of 1 to 8. However, when Q is N (CN), n is an integer of 2 or more. The groups represented by Z, R and Q may be the same or different. 2. An electrophotographic photosensitive member for positive charging comprising a photosensitive layer provided on a conductive support, wherein the photosensitive layer is at least a charge-generating substance represented by the structural formula (A) and / or the structural formula A photosensitive layer having a single-layer structure containing a charge generation material represented by (B), a hole transporting material represented by the general formula (1), and an electron transporting material represented by the general formula (2). An electrophotographic photosensitive member for positive charging, comprising: