JPH0253066A - Photosensitive body - Google Patents

Abstract

PURPOSE:To stabilize electrostatic chargeability at the time of repetitive use and to decrease residual potential by incorporating a compd. selected from a group consisting of specific compds. and an electron acceptive material into the photosensitive body. CONSTITUTION:The compd. selected from the group consisting of the compds. expressed by formula I, formula II and the electron acceptive material are incorporated into the photosensitive body. In formulas I, II, Ar<1> denotes an aryl group; Ar<2> denotes an arylene group; Ar<3> denotes a p-phenylene group or naphthylene group; R<1>, R<2> denote an alkyl group; R<3>, R<4> denote a dialkyl amino group; Ar<4>, Ar<5> denote a phenyl group; (m), (n) denote 0 or 1. The film properties are improved in this way and the electrophotographic characteristics such as charge holding power, sensitivity and residual potential are improved in spite of a low carrier transfer material concn. In addition, the stable characteristics to decrease the fatigue deterioration in spite of repetitive use are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a photoreceptor, such as an electrophotographic photoreceptor.

BACKGROUND ART Conventionally, inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used as electrophotographic photoreceptors. However, these were not always satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc.For example, selenium
Crystallization deteriorates the properties as an electrophotographic photoreceptor, making it difficult to manufacture, and crystallization occurs due to heat, fingerprints, etc., resulting in a reduction in the properties as an electrophotographic photoreceptor. Additionally, cadmium sulfide and zinc oxide have problems with moisture resistance and durability.

In order to overcome these drawbacks of inorganic photoreceptors, research and development of organic photoreceptors having photosensitive layers mainly composed of various organic photoconductive compounds has been actively conducted in recent years.

For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor comprising a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-dolinitro-9-fluorenone. However, this photoreceptor was not necessarily satisfactory in terms of sensitivity and durability.

In order to improve these drawbacks, attempts have been made to develop a high-performance organic photoreceptor in which the carrier generation function and the carrier transport function are shared by different substances. Many studies have been conducted on such so-called functionally separated electrophotographic photoreceptors because each material can be selected from a wide range and an electrophotographic photoreceptor with arbitrary performance can be produced relatively easily. It has been done.

As a result, various azo compounds have been developed and put into practical use as carrier-generating substances. On the other hand, regarding carrier transport substances, for example, JP-A-51-94829;
No. 2-4242, No. 52-72231, No. 53270
A wide variety of substances have been proposed, as disclosed in No. 33, No. 55-52063, No. 58-65440, No. 58-1198425, No. 60-196768, etc.

[Problem that the invention seeks to solve]

Here, solutions to the following problems are required.

(a) Some electrophotographic photoreceptors using carrier transport materials as described above exhibit relatively excellent electrophotographic performance, but they have poor durability against light, ozone, or electrical loads, and when used repeatedly. However, it does not fully satisfy practical requirements because its performance is unstable and causes deterioration, etc., and it is necessary to develop carrier transport materials that have even better carrier transport functions and exhibit stable performance over long periods of use. development was desired.

(b) In recent years, the demand for incorporating organic photoreceptors into electrophotographic copying machines capable of copying at higher speeds has been increasing, and the development of photoreceptors with higher sensitivity and higher durability has been desired.

Generally, the carrier transport substance in the carrier transport layer is a binder 1
It is often used in the range of 60 parts by weight to 100 parts by weight per 00 parts by weight.
This is because the intermolecular distance of the carrier transport substance has an important meaning. That is, if the concentration of the carrier transporting substance is below this level, the distance between the molecules of the carrier transporting substance becomes large, making it difficult to transport carriers, and as a result, the sensitivity decreases significantly.

On the other hand, from the viewpoint of durability, the lower the concentration of the carrier transport substance in the carrier transport layer, the stronger the coating strength of the carrier transport layer will be, making it less likely to be scratched. It has the advantage that there is little friction on the surface due to the magnetic brush, and it has extremely high durability.

Therefore, it has been desired to develop a carrier transporting substance that exhibits less decrease in sensitivity even when the concentration of the carrier transporting substance is low.

Currently, there is an increasing demand for high-speed copying in copying machines, printers, etc., and the number of copies is also increasing, requiring higher durability. However, at present, it is difficult to achieve both reduction in fatigue and high sensitivity and high-speed response of electrophotographic photoreceptors.

An object of the present invention is to provide a photoreceptor that can stabilize charging ability and reduce residual potential during repeated use, and that can provide high sensitivity and high-speed response. It is.

20 Structure of the invention and its effects This invention provides a compound selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (n), and an electron-accepting compound. The present invention relates to a photoreceptor having a substance.

General formula (1) (Ar' represents a substituted or unsubstituted aryl group.

Ar" represents a substituted or unsubstituted arylene group.

Ar3 represents a p-phenylene group or a naphthylene group.

RI and R2 represent a substituted or unsubstituted alkyl group,
] General formula (n) Ar' and Ar5 represent a substituted or unsubstituted phenyl group.

m and n represent O or 1, and m and n do not become O at the same time.] According to the photoreceptor of the present invention, carrier transport of the compound represented by the general formula (1) or (n) is carried out. By using this material as a carrier transport material in a so-called function-separated electrophotographic photoreceptor in which carrier generation and transport are performed using separate substances, the coating has excellent physical properties and can maintain charge even at low carrier transport material concentrations. It has excellent electrophotographic properties such as holding power, sensitivity, and residual potential, and exhibits little fatigue deterioration even after repeated use, and exhibits stable properties against heat, ozone, and light.

Especially low carrier shipments! General formulas (1) and (I[) in the photosensitive layer have excellent electrophotographic properties in terms of density.
By lowering the concentration of the compound, the strength of the coating on the photoreceptor can be increased and the durability can be improved. This effect is particularly noticeable in layers existing on the surface side of the photoreceptor, such as a carrier transport layer (described later).

Further, by lowering the concentration of the carrier transport substance, potential defects that appear as black dot-like image defects can be effectively prevented in printers that perform reversal development using a semiconductor laser.

It is also important that the photoreceptor contains an "electron-accepting substance."

That is, by employing such a configuration, it is possible to reduce fatigue of the photoreceptor during repeated use, and it is possible to maintain good photosensitivity. Further, an increase in residual potential can be prevented, and charging ability can also be maintained well.

In particular, when the concentration of the carrier transport substance is lowered, the photoreceptor tends to become fatigued during repeated use and the residual potential tends to increase. Therefore, significant effects can be achieved by adding electron-accepting substances.

Particularly, in the carrier transport layer (described later) of a negatively charged photoreceptor, the effect of adding an electron-accepting substance is remarkable.

Next, compounds represented by general formulas (I) and (If) will be described.

In the formula, Ar' represents an aryl group, preferably a phenyl group, or a naphthyl group, and 6Ar'' represents an arylene or naphthylene group. There is no particular restriction on the Zta position of the naphthylene group.

R' and R'' represent an alkyl group, preferably an alkyl group having 1 to 8 carbon atoms.

Preferred substituents for these include an alkyl group, an aralkyl group, an alkoxy group, a halogen atom, an aryl group, an aryloxy group, a cyano group, or a substituted amino group. The substituted alkyl group includes an aralkyl group, and the aralkyl group is preferably a benzyl group or a phenethyl group.

In general formula (II), R3 and R4 represent a dialkylamino group, and preferred examples include a dimethylamino group, a diethylamino group, a dipropylamino group, and a dibutylamino group. The substitution position of the dialkylamino group is preferably the para position. Ar' and Ar' represent a phenyl group, and examples of substituents for this phenyl group include those mentioned above, but in particular, a methyl group, a methoxy group, a halogen atom, etc. Preferably, the substitution position is preferably the para position.

As the carrier transport substance, compounds represented by the general formula [1] can be used alone or in combination of two or more. The same applies to the compound represented by the general formula (n). Moreover, the compounds represented by formulas (1) and (II) can also be used together.

Next, specific examples of compounds represented by general formulas (1) and (II) will be illustrated, but the invention is not limited thereto.

Exemplary compounds (blank below) ■ B ■ ■-18 ■ ■ ■-16 ■-2-21 ■ ■ η The above-mentioned stilbene derivatives can be easily synthesized by known synthesis methods.

(Leaving space below) ■ ■ ■ ■−Invitation ■ ■ δ ■ l−10 ■ ■−12 ■−17 ■ ■ ■ ■−加■−21 1 [−25 ■−Otsu l−26 ■−Otsu l−27 ■ -Sae■-Da-41-30 The electron-accepting substance used in the present invention refers to a compound having a large electron affinity, and examples thereof include the following compounds.

Namely, succinic anhydride, maleic anhydride, dibromo succinic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromo phthalic anhydride, 3-nitro phthalic anhydride, 4
-Nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene,
1.3゜5-trinitrobenzene, paranitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, brumanil, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, 9-
Fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene [dicyanomethylene malonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5. -Dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3.5-dinitrosalicylic acid, phthalic acid, mellitic acid, and one or more kinds of other compounds with high electron affinity can be mentioned. Among these, fluorenone series, quinone series, and benzene derivatives having electron-withdrawing substituents such as C1, CN, and No are particularly preferred.

As an electron-accepting substance, electron affinity is 0.3 to 1.8.
eV is preferable, and 0.5 to 1-5 eV is more preferable.

In the photosensitive layer of the photoreceptor of the present invention, the content ratio of the electron-accepting substance to the carrier-transporting substance is preferably 0.05 to 50:100 by weight, and 0.1. ˜10:100 is more preferable, which has the effect of further suppressing the increase in residual potential and increasing the charging ability.

Next, the structure, prescription, etc. of the photoreceptor will be described.

As shown in FIGS. 1 and 2, the photoreceptor of the present invention comprises a carrier generating layer 2 containing a carrier-generating substance as a main component on a conductive support 1, and a carrier-generating layer 2 containing a carrier-generating substance as a main component and the compound of the present invention as a main component of a carrier-transporting substance. A photosensitive layer 4 made of a laminate with a carrier transport layer 3 containing the photosensitive layer 4 is provided.

As shown in FIGS. 3 and 4, this photosensitive layer 4 may be provided through an intermediate layer 5 provided on the conductive support 1.
When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having the best electrophotographic properties can be obtained. Further, in the present invention, as shown in FIGS. 5 and 6, a photosensitive layer 4 formed by dispersing a carrier generating substance 7 in the form of fine particles in a layer 6 mainly composed of the carrier transporting substance is used as a conductive support. 1 or may be provided via an intermediate layer 5.

Furthermore, a protective layer 8 may be provided on the photosensitive layer 4 if necessary.

When the photosensitive layer 4 has a two-layer structure, which of the carrier generation layer 2 and the carrier transport layer 3 is to be the upper layer is determined by whether the charging polarity is positive or negative. That is, in the case of a negatively charged photosensitive layer, the carrier transport layer 3
It is advantageous to use the carrier transport layer 3 as the upper layer because the carrier transport material in the carrier transport layer 3 is a material that has a high transport ability for holes.

In the carrier transport layer 3, the content ratio of the carrier transport substance of the present invention is preferably 0.8 to 10 parts by weight of the binder to 1 part by weight of the carrier transport substance of the present invention. Further, the carrier transporting substance of the present invention can be added to the carrier generation layer 2, and the content ratio at this time is as follows: carrier transporting substance of the present invention: carrier generating substance = (20 to 80 parts by weight: 100 parts by weight). It is preferable to do so.

The electron-accepting substance may be added to any of the carrier generation layer 2, the carrier transport layer 3, the sublayer N5, the single-layer photosensitive layer, and the protective layer, or may be added to multiple layers.

The amount of the electron-accepting substance added is not constant depending on the layer structure of the photoreceptor, the type of carrier transport material 'I (CTM), etc., but it is preferably within the following range.

When entering the carrier generation layer, a carrier generation substance (C
It is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 20 parts by weight, per 100 parts by weight of GM).

When added to the carrier transport layer, it is preferably 0.01 to 50 parts by weight per 100 parts by weight of CTM, and 0.01 to 10 parts by weight.
When included in an intermediate layer such as an undercoat layer, or a protective layer, it is preferably contained in parts by weight of 0.01 to 50 parts by weight based on 100 parts by weight of the binder material (resin) constituting the core layer. is preferred.

The carrier generating substance used in the photoreceptor of the present invention is as follows:
In general, both inorganic pigments and organic pigments can be used as long as they absorb visible light and generate free charges. In addition to inorganic pigments such as amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide, cadmium selenide, cadmium selenide sulfide, mercury sulfide, lead oxide, and lead sulfide, the following Organic pigments such as those shown in the representative examples may also be used.

(1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo and thiazole azo pigments (2) Perylene pigments such as perylenic anhydride and perylenic acid imide (3) Anthraquinone derivatives , ananthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives,
Anthraquinone or polycyclic quinone pigments such as violanthrone derivatives and isoviolanthrone derivatives (4) Indigoid pigments such as indigo derivatives and thioindigo derivatives (5) Phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanines (6) Diphenylmethane pigments pigments, carbonium pigments such as triphenylmethane pigments, xanthine pigments and acridine pigments (7) quinone imine pigments such as azine pigments, oxazine pigments and thiazine pigments (8) methine pigments such as cyanine pigments and azomethine pigments (9) quinoline Pigments (10) Nitro pigments (11) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13)
Naphthalimide pigments (14) Perinone pigments such as bisbenzimidazole derivatives In addition, the following carrier-generating substances can be specifically exemplified as preferred.

Azo Exemplary Pigment VT-(A) (Hereinafter, blank) As the CGM compound used in the present invention, in addition to the above-mentioned exemplary compounds, compounds described in JP-A-60-172045 and the like can be used.

The carrier transporting substance used in the present invention does not have the ability to form a film by itself, so a photosensitive layer is formed by combining it with various binders.

Although any binder can be used for the carrier generation layer and the carrier transport layer, it is preferable to use a hydrophobic electrically insulating film-forming polymer. Examples of such high molecular weight polymers include, but are not limited to, the following.

(1) Polycarbonate (2) Polyester (3) Methacrylic resin (4) Acrylic resin (5) Polyvinyl chloride (6) Polyvinylidene chloride (7) Boristyrene (8) I'glyvinyl acetate (9) Styrene copolymerization Resins (e.g., styrene-butadiene copolymer, styrene-methyl methacrylate copolymer,
(10) Acrylonitrile copolymer resin (e.g. vinylidene chloride-acrylonitrile copolymer, etc.) (11) Vinyl chloride-vinyl acetate copolymer (12) Vinyl chloride-vinyl acetate-maleic anhydride copolymer (13) Silicone resin (14) Silicone-alkyd resin (15) Phenolic resin (e.g., phenol-formaldehyde resin, cresol formaldehyde resin, etc.) (16) Styrene-alkyd resin (17) Poly-N-vinylcarbazole (18) Polyvinyl butyral (19) Polyvinyl formal (20) Polyhydroxystyrene These binders can be used alone or in a mixture of two or more.

Further, the intermediate layer functions as an adhesive layer or a barrier layer, and in addition to the binder resin, for example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, casein, etc. are used.

As the conductive support used in the construction of the photoreceptor of the present invention, the following are mainly used, but the present invention is not limited thereto.

(1) Metal plates such as aluminum plates and stainless steel plates, and drum-shaped ones.

(2) A thin layer of metal such as aluminum, palladium, or gold is provided on a support such as aluminum or plastic film by lamination or vapor deposition.

(3) A layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided on a support such as paper or a plastic film by coating or vapor deposition.

In the photoreceptor of the present invention, it is also possible to use other carrier transport substances in combination within a range that does not impair the effects of the present invention.

It is also possible to use different carrier transport materials in the carrier generation layer and the carrier transport layer.

The carrier generation layer constituting the two-layered photosensitive layer is formed directly on the conductive support or carrier transport layer, or with an intermediate layer such as an adhesive layer or barrier layer as required, and then It can be formed by a method.

(1) Vacuum deposition method (2) Method of applying a solution of a carrier-generating substance dissolved in a suitable solvent (3) Forming the carrier-generating substance into fine particles in a dispersion medium using a ball mill, sand grinder, etc.
A method of applying a dispersion obtained by mixing and dispersing a binder.

Formation of constituent layers such as a carrier transport layer and a carrier generation layer according to the present invention includes vacuum evaporation, sputtering, CV
A vapor deposition method such as D or a coating method such as dipping, spraying, blade, or roll method may be arbitrarily used.

The thickness of the carrier generation layer is preferably 0.01 μm to 5 μm, more preferably 0.05 μm to 3 μm.

Further, the thickness of the carrier transport layer may be changed as necessary, but it is usually preferably 5 to 30 μm.

When forming a photosensitive layer having a single layer structure in which a particulate carrier-generating substance is dispersed, it is preferable to use a binder in an amount of 5 parts by weight or less per 1 part by weight of the carrier-generating substance.

Further, when the carrier generation layer is configured as a dispersed type layer using a binder, it is preferable to use the binder in an amount of 5 parts by weight or less per 1 part by weight of the carrier generating substance.

The photoreceptor of the present invention can be used with various light sources such as halogen lamps, tungsten lamps, LEDs (light emitting diodes), gas lasers such as helium-neon, argon, and helium-cadmium, and semiconductor lasers.

The photoreceptor of the present invention has a wide variety of uses such as electrophotographic copying machines and printers.

E. Examples Examples of the present invention will be explained in more detail below.
The present invention is not limited thereby, and of course includes other embodiments with various modifications.

(Preparation of child photographic photoreceptors) First, each electrophotographic photoreceptor was prepared as follows.

Application 1. Eave side 1 On a conductive support made of aluminum foil laminated on a polyester film, 1 part by weight of bisazo pigment, the above-mentioned CGMVI-70, as a carrier generating substance and polymethyl methacrylate resin "Dianal BR-80J" were applied.
(Mitsubishi Rayon Co., Ltd.) 0.5 parts by weight was added to 100 parts by weight of 1,2-dichloroethane and dispersed for 4 hours using a sand grinder, and a solution was applied so that the film thickness after drying was 0.4 μm. A carrier generation layer was formed.

Next, exemplified compound (2) was added to 4. as a carrier transport substance.
0 parts by weight, 1,3.5-trinitrobenzene, polycarbonate resin 10 parts by weight of Panlite 11500J (manufactured by Kijin Kasei Co., Ltd.) was dissolved in 100 parts by weight of 1,2-dichloroethane, and the film thickness after drying was A carrier transport layer was formed and an electrophotographic photoreceptor of the example was obtained.The amount of 1.3° 5-trinitrobenzene added was 0.3° with respect to the carrier transport material (CTM). It was bound at 1% by weight.

Furthermore, in Example 1, CTM was changed to (ii) below, and the electron-accepting substance was removed. Others are Example 1
An electrophotographic photoreceptor of a comparative example was produced in the same manner as described above.

Example 5.6, Comparison 5.6 In Example 1, CGM, CTM, electron-accepting substance (
Each electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the additive compounds) were changed as shown in the table below.

2. r2 A 0.1 μm thick medium made of vinyl chloride-vinyl acetate-maleic anhydride co-tl r S-refuku MF10 (manufactured by Block Chemical Co., Ltd.) was placed on a conductive support made by vapor-depositing aluminum on a polyester film. Layers were set up.

On top of that, 1
Weight parts and polycarbonate resin [Panrai] L-125
0J (manufactured by Kijin Kasei Co., Ltd.) and 0.5 parts by weight were mixed with 100 parts by weight of 1,2-dichloroethane.
A carrier generation layer was formed by applying the time-dispersed liquid so that the film thickness after drying was 1 μm.

It was bound at 0.1% by weight.

Further, in Example 2, CTM was changed to (iii) below, and an electrophotographic photoreceptor of Comparative Example 2 was prepared in the same manner as in Example 1 except for this.

CTM (ii) (iii) A solution prepared by dissolving 10 parts by weight of Panlite L-L250J in 80 parts by weight of 1°2-dichloroethane was applied so that the film thickness after drying was 16 μm, and the carrier was transported. A layer was formed to produce an electrophotographic photoreceptor of Example 2.

The amount of promanil added was as follows: CGMVI-66 (ε-type copper) talocyanin) obtained by a known method for CTM.
0 g of polyvinyl butyral (Srefuku BL-3:
(manufactured by Sekisui Chemical Co., Ltd.) and 98 ml of 1,2-dichloroethane, and dispersed with an ultrasonic disperser to obtain a dispersion. This dispersion was applied to a conductive support made of a polyester film laminated with aluminum foil so that the film thickness after drying was 0.3 μm, and dried to form a CGL. 4, 1.2 parts by weight of the additive compound m-dinitrobenzene, and 20 parts by weight of polycarbonate resin Z-200 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) represented by the following structural formula.
- 1 part of the solution dissolved in 100 parts by weight of dichloroethane
A photoreceptor of Example 3 was prepared by coating the film to a thickness of 5 μm. However, the amount of m-dinitrobenzene added is CTM
0.1% by weight.

Further, in Example 3, the CTM was changed to the above (ij), and the electrophotographic photoreceptor of Comparative Example 3 was obtained in the same manner as in Example 3 except for this.

Furthermore, in Example 3, the CGM, CTM, and electron-accepting substance (additive compound) were changed as shown in the table below, and the electrophotographic photoreceptors of Example 4 and Comparative Example 4 were manufactured in the same manner as in Example 3 except for the above. I got it.

(Measurement of Photoreceptor Characteristics) The electrophotographic characteristics of each of the electrophotographic photoreceptors obtained as described above were measured by the Guinamisoku method using an electrostatic copying paper tester rEPA-8100 (Kawaguchi Denki Seisakusho).

In other words, the illuminance of the light from the tungsten lamp on the surface of the photoreceptor is 3.
．． 51! ux, and the surface potential is -6.
The amount of exposure required to attenuate from 00■ to -1O0V (
Sensitivity) Ein: and surface potential (residual potential) after irradiation with an exposure amount of 301 ux-sec were determined.

In addition, the electrophotographic process of charging-exposure-transfer was repeated 10,000 times, El:; after 10,000 copies was determined, and the variation value ΔV during printing was measured. The results are shown in the table below.

As shown in the table, the electrophotographic photoreceptors of Examples are superior to the photoreceptors of Comparative Examples in sensitivity and stability during repeated use.

Regarding an example in which the content of the carrier transport substance was changed> A carrier generation layer was formed in the same manner as in Example 3 described above.

Next, exemplified compounds (1-3,
■-3) is added as a carrier transporting substance, and an electron accepting substance (1,3,5-trinitrobenzene>
Add 0.01 part by weight to 50% of 1°2-dichloroethane.
This was dissolved in parts by weight and coated to prepare an electrophotographic photoreceptor having a carrier transport layer with a thickness of 20 μm. However, the content of each carrier transport substance was changed to 7.5 parts by weight, 6.0 parts by weight, 5.0 parts by weight, 4.0 parts by weight, and 3.0 parts by weight.

Further, a comparative photoreceptor was prepared in the same manner as in the above example except that a stilbene derivative represented by the following structural formula was used as a carrier transporting substance. However, the content of the carrier transport substance was changed in the same manner as above.

For each of these photoreceptors, the sensitivity (E::',) after 10,000 copies was measured in the same manner as described above.

The results are shown in FIGS. 7 and 8.

As is clear from the results shown in FIGS. 7 and 8, the electrophotographic photoreceptor of the example was significantly superior in sensitivity and repetition stability compared to the comparative photoreceptor, especially in the low concentration region of the carrier transport substance. It also has extremely excellent characteristics with little decrease in sensitivity.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are sectional views showing examples of the mechanical configuration of the photoreceptor of the present invention, respectively. FIG. 7 and FIG. 8 are graphs showing the relationship between the amount of carrier transport substance and sensitivity, respectively. In addition, in the symbols shown in the drawings, 1.
----Carrier generation layer 3--Carrier transport layer 4--Photosensitive layer 5-----11--Intermediate layer 6--1・−Layer 7 containing carrier transport substance−
−11−−−−−−Carrier generating substance 8− ・−・−
It is a protective layer. Agent Patent Attorney Aisaka Youngest brother 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Mourning

Claims (1)

[Claims] 1. A photosensitive material comprising a compound selected from the group consisting of a compound represented by the following general formula [I] and a compound represented by the following general formula [II] and an electron-accepting substance. body. General formula [I] ▲Mathematical formulas, chemical formulas, tables, etc.▼ [Ar^1 represents a substituted or unsubstituted aryl group. Ar^2 represents a substituted or unsubstituted arylene group. Ar^3 represents a p-phenylene group or a naphthylene group. R^1 and R^2 represent substituted or unsubstituted alkyl groups. ] General formula [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [R^3 and R^4 represent dialkylamino groups. Ar^4 and Ar^5 represent substituted or unsubstituted phenyl groups. m and n represent 0 or 1, and m and n are never 0 at the same time. ]