JPH01263657A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body superior in physical film property and electrophotographic characteristics, such as charge holding ability, sensitivity, and residual potential stability even in the case of using a carrier transfer material low in concentration by forming a photosensitive layer containing at least one of specified stilbene derivatives on a conductive substrate. CONSTITUTION:An interlayer made of a copolymer of vinyl chloride, vinyl acetate, and maleic anhydride is attached to the conductive substrate made of a polyester film coated with a vapor deposited aluminum film, and on this interlayer is coated the photosensitive layer containing at least one of the stilbene derivatives represented by formula I in which each of Ar1 and Ar2 is aryl; Ar3 is arylene; Ar4 is p-phenylene or naphthylene; and each of R1 and R2 is alkyl or aralkyl each optionally substituted, thus permitting fatigue deterioration is reduced, and characteristics against heat and ozone and light to be stabilized even in the case of using repeatedly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to a novel electrophotographic photoreceptor having a photosensitive layer containing an organic photoconductive compound as a main component.

[Prior 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 are not necessarily satisfactory in terms of sensitivity, thermal stability, moisture resistance, durability, etc. For example, when selenium crystallizes, its properties as an electrophotographic photoreceptor decrease, making it difficult to manufacture.Also, selenium crystallizes due to heat, fingerprints, etc., resulting in a decrease in its 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 have been actively conducted in recent years on organic photoreceptors having photosensitive layers containing various organic photoconductive compounds as main components.

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 is 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. 53-27
No. 033, No. 55-52063, No. 58-65440
No. 58-1198425, No. 60-196768
A wide variety of substances have been proposed, as disclosed in the No.

[Problem that the invention seeks to solve]

Some electrophotographic photoreceptors using carrier transport materials such as those described above exhibit relatively excellent electrophotographic performance, but their durability against light, ozone, or electrical loads is low, and their performance deteriorates after repeated use. Because it is unstable and causes deterioration, it does not fully satisfy practical requirements.
It has been desired to develop a carrier transport material that has even better carrier transport function and exhibits stable performance over long periods of use.

Furthermore, the demand for installing organic photoreceptors in electrophotographic copying machines capable of copying at higher speeds has been increasing in recent years, 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 a range of 60 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 in carrier transport. That is, if the concentration of the carrier transporting substance is less than this, 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, and even when used for a long period of time, it will be easier to use with a cleaning blade or It has the advantage that there is little friction on the surface due to the magnetic brush, and it is extremely durable.

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.

The present invention has been carried out in order to solve these problems and provide a photoreceptor that has extremely high sensitivity and high durability even when the concentration of a carrier transport substance is low.

[Means for solving problems]

The above problem is solved by an electrophotographic photoreceptor having a photosensitive layer comprising a layer containing a carrier transporting substance represented by the following general formula [■] on a conductive support.

General formula (1) In the formula, Ar represents an aryl group, preferably a phenyl group or a naphthyl group. Ar represents an arylene group, preferably a phenylene group or a naphthylene group. Ar, is p-phenylene group (-(]←)
, or represents a naphthylene group. RI%R2 represents an alkyl group or an aralkyl group, preferably an alkyl group having 1 to 8 carbon atoms, a benzyl group, or a phenethyl group. Moreover, these groups may have a substituent. Preferred substituents include alkyl groups, aralkyl groups,
Examples include an alkoxy group, a halogen atom, an aryl group, an aryloxy group, a cyano group, and a substituted amino group.

That is, in the present invention, the carrier transport ability of the compound represented by the general formula CI) is utilized to create a carrier transport material for a so-called functionally separated electrophotographic photoreceptor in which carrier generation and transport are performed using separate substances. By using it as a coating, it has excellent physical properties, and has excellent electrophotographic properties such as charge retention, sensitivity, and residual potential even at low carrier transport substance concentrations, and has little fatigue deterioration even when subjected to repeated use. It is possible to create an electrophotographic photoreceptor that exhibits stable characteristics even against ozone or light.

Furthermore, the carrier transporting substance used in the present invention can be used alone or in combination of two or more of the compounds represented by the general formula CI), and can also be used in combination with other carrier transporting substances. good.

Specific examples of the carrier transport substance represented by the general formula [■] that are effective in the present invention include those having the following structural formula, but the carrier transport substance according to the present invention is limited by this. Stilbene derivatives such as those described above can be easily synthesized by known synthesis methods. For example, Organic
Reactions vol, 25 P, 73 (Jo
hn Willey & 5ons, Inc.), an aromatic aldehyde represented by the following - Monana (n) and a dialkyl phosphonate represented by the following general formula [I] are mixed in a solvent such as N,N-dimethylformamide. , sodium alkoxide, etc., by condensation.

Here, Ar, Ar2, Ar, R, and R2 are the same groups as in general formula (1), and R1 is an alkyl group or an aryl group.

Next, a typical method for synthesizing the stilbene derivative of the present invention will be specifically explained.

Synthesis Example (Synthesis of Exemplary Compound (2)) 5.5 g of N,N-diphenylaminobenzaldehyde (
0.02 mol) and 6.0 g (0.02 mol) of diethyl p-diethylaminobenzylphosphonate are dissolved in 70 ml (l) of N,N-dimethylformamide.

To this solution was added 1 g of sodium hydride (0.04
mol) gradually while keeping the internal temperature below 5°C.

Thereafter, the mixture was stirred for 1 hour under water cooling and for 5 hours at room temperature.

Crystals precipitated by adding 50 m+2 of ice water were collected by filtration and recrystallized twice from a mixed solvent of toluene/isopropyl alcohol-1/2.

Yield 4.5g (53.8%) Melting point 108°C! -109°C FD-mass spectrum m/e418 molecular ion p~
It was confirmed that the target product was obtained by detecting the difference.

Next, as a carrier generating substance suitable for the present invention, an azo pigment is preferable, but in general, any inorganic pigment or organic pigment can be used as long as it absorbs visible light to infrared light and generates free carriers. be able to. For example, in addition to inorganic pigments such as amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, and cadmium sulfide, organic pigments such as those shown in the following representative examples may be used.

(1) Monoazo pigment, bisazo pigment, trisazo pigment,
Azo pigments such as metal complex azo pigments (2) Perylene pigments such as perylene anhydride and perylene imide (3) Anthraquinone derivatives, anthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives,
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 phthalocyanine and metal-free phthalocyanine (6) Diphenylmethane pigment, triphenylmethane pigments, carbonium pigments such as xanthine pigments and acridine pigments (7) quinone imine pigments such as azine pigments, oxazine pigments and thiazine pigments (8) methine pigments such as anine pigments and azomethine pigments (9) quinoline pigments (10) Benzoquinone and naphthoquinone pigments (11
) Naphthalimide pigment (12) Perinone pigment such as bisbenzimidazole derivative The carrier transport 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) Polystyrene (8) Polyvinyl acetate (9) Styrene copolymer resin (e.g. styrene -butadiene copolymer, styrene-methyl methacrylate copolymer, etc.) (■0) Acrylonitrile copolymer resin (for example,
(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 resins (e.g., phenol-formaldehyde resins, cresol formaldehyde resins, etc.) (16) Styrene-alkyd resins (17) Poly-N-vinylcarbazole (18) Polyvinyl butyral (19) Polyvinyl formal (20) Polyhydroquine styrene These These binders can be used alone or as a mixture of two or more.

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 l, and a carrier-generating layer 2 containing a carrier-generating substance as a main component and a compound of the present invention as a main component of a carrier-transporting substance. A photosensitive layer 4 consisting of a ridge layer body with a carrier transport layer 3 contained therein is provided.

As shown in FIGS. 3 and 4, this photosensitive layer 4 may be provided on the conductive support 1 via an intermediate layer 5.

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. It may be provided directly on the layer 1 or via the 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.

Further, a carrier generation layer 2 constituting a photosensitive layer 4 having a two-layer structure
can be formed directly on the conductive support l or the carrier transport layer 3 or after providing an intermediate layer such as an adhesive layer or a barrier layer if necessary, by the following method.

(1) Vacuum evaporation method (2) Method of applying a solution of a carrier-generating substance dissolved in a continuous light 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.

The thickness of the carrier generation layer 2 formed in this way is
It is preferably 0.01 μm to 5 μm, more preferably 0.05 μm to 3 μm.

Further, the thickness of the carrier transport layer 3 can be changed as necessary, but it is usually preferably 5 μm to 30 μm. The composition ratio in this carrier transporting layer 3 is preferably 0.8 to 10 parts by weight of the binder to 1 part by weight of the carrier transporting substance of the present invention. When forming the photosensitive layer 4, 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.

Further, when the carrier generation layer is configured as a dispersed 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 layer structure of the photoreceptor of the present invention includes a laminated structure and a single layer structure as described above, and either a carrier transport layer serving as a surface layer, a carrier generation layer, a single layer photosensitive layer, or a protective layer, or a plurality of layers. The layer may contain one or more electron-accepting substances for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

The intermediate layer functions as an adhesive layer or barrier 1, and in addition to the binder resin, for example, polyvinyl alcohol, ethyl cellulose, carboxyl methyl cellulose, casein, etc. are used.

As the conductive support 1 used in the construction of the electrophotographic 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 paper or plastic film by lamination or vapor deposition.

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

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 used as desired.

The electrophotographic photoreceptor of the present invention has the above structure,
As is clear from the examples described below, even if the concentration of the carrier transport substance is low, the charging characteristics, sensitivity characteristics, and image forming characteristics are excellent. In particular, it exhibits extremely excellent durability with little fatigue deterioration even when subjected to repeated transfer electrophotography.

〔Example〕

Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited thereby.

Example 1 A conductive support formed by vapor-depositing aluminum lamura on a polyester film was coated with a film made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-104 (manufactured by Tsukisui Kagaku Co., Ltd.) with a thickness of 0.5 mm. A 1 μm intermediate layer was provided.

On top of that is dibrome anthron "Monolite Red 2 YJ (manufactured by IC1) 1, which is represented by the following structural formula.
Part by weight and polycarbonate resin “Panlite ■, -1
250'' (manufactured by Teijin Chemicals) and 0.5 parts by weight of 1,2-dichloroethane were mixed with 100 parts by weight of 1,2-dichloroethane, and 24
A carrier generation layer was formed by applying the time-dispersed liquid so that the film thickness after drying was 1 μm.

In addition, exemplified compound (1) 4. is added as a carrier transport substance.
0 parts by weight and polycarbonate resin "Panlite L -
10 parts by weight of 1250J and 8 parts by weight of 1,2-dichloroethane
A carrier transport layer was formed by coating a solution dissolved in 0 parts by weight so that the film thickness after drying was 16 μm, thereby producing an electrophotographic photoreceptor of the present invention.

Regarding this electrophotographic photoreceptor, the electrostatic copying paper tester rE
Electrophotographic properties were measured using a dynamic method using PA-8100J (Kawaguchi Electric Seisakusho).

That is, when the surface of the photosensitive layer of the photosensitive member is charged with a charging voltage of -6 KV for 5 seconds, the surface potential VA1 is then applied to the illuminance of the photosensitive member surface by the light from the tungsten lamp. ! lux, and the surface potential was increased from -600V to -110V.
Exposure amount (sensitivity) required to attenuate to 0V E';::
, and the surface potential (residual potential) Vl after irradiation with an exposure dose of 3012 ux-5 ec were determined.

Further, similar measurements were repeated 100 times. Result is,
As shown in Table 1.

Comparative Example (1) A comparative photoreceptor (1) was prepared in the same manner as in Example 1, except that a stilbene derivative represented by the following structural formula was used as a carrier transport substance, and a photoreceptor (1) was prepared in the same manner as in Example 1 and in the following. As is clear from the results shown in the table, the electrophotographic photoreceptor of the present invention of Example 1 is significantly superior to the photoreceptor of Comparative Example (1) in terms of sensitivity, residual potential characteristics, and repeated stability. .

Examples 2 to 10 Exemplary compounds (2) and (4) as carrier transport substances
.

(6), (8), (10), (12), (14), (1
An electrophotographic photoreceptor of the present invention was produced in the same manner as in Example 1 except that 6) and (18) were used. Measurements were performed on these electrophotographic photoreceptors in the same manner as in Example 1.

The results are shown in Table 2.

Example 11 1 part by weight of a bisazo pigment represented by the following structural formula and a polymethyl methacrylate resin [Dianal BR-11oJ (
Mitsubishi Rayon Co., Ltd.)) was added to 100 parts by weight of 1,2-dichloroethane and dispersed for 4 hours using a sand grinder, and the resulting solution was applied to a dry film thickness of 0.4 μm to form a carrier generation layer. was formed.

Next, Exemplified Compound (8) 4.0 as a carrier transport substance
Weight parts and polycarbonate resin [Panlite K-13
A solution obtained by dissolving 10 parts by weight of 00J (manufactured by Ondai Kasei Co., Ltd.) in 100 parts by weight of 1,2-dichloroethane is applied so that the film thickness after drying is 15 μm to form a carrier transport layer. A photographic photoreceptor was created.

This electrophotographic photoreceptor was measured in the same manner as in Example 1, and the results shown in Table 3 were obtained.

Comparative Example (2) A comparative photoreceptor (2) was prepared in the same manner as in Example 11, except that a stilbene derivative represented by the following structural formula was used as a carrier transport substance. When this comparative photoreceptor was measured in the same manner as in Example 1, the results shown in Table 3 were obtained.

As is clear from the results in Table 3 and above, the electrophotographic photoreceptor of the present invention of Example 11 is significantly superior to the comparative photoreceptor in terms of sensitivity, residual potential, and repeated stability.

Example 12 A 0-thick film made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J" was deposited on a conductive support formed by vapor-depositing aluminum lamura on a polyester film.
．． A 1 pm interlayer was provided.

On top of that, 1 part by weight of a bisazo pigment represented by the following structural formula as a carrier generating substance and 5 parts by weight of polycarbonate resin "Panlite K-1300J O" were added to 100 parts by weight of tetrahydrofuran, and the liquid was dispersed in a ball mill for 24 hours and dried. A carrier generation layer was formed by coating so that the subsequent film thickness was 0.4 μm.

Next, an exemplified compound (5) was added thereon as a carrier transport substance.
) 3.5 parts by weight and polycarbonate resin [Panlite K
An electrophotographic photoreceptor of the present invention was prepared by dissolving 10 parts by weight of -1300J in 100 parts by weight of tetrahydrofuran and applying the solution to a dry film thickness of 17 μm.

When this electrophotographic photoreceptor was measured in the same manner as in Example 1, the results shown in Table 4 were obtained.

Example 13 An electrophotographic photoreceptor of the present invention was prepared in the same manner as in Example 12, except that a bisazo pigment represented by the following structural formula was used as a carrier-generating substance.

When this electrophotographic photoreceptor was measured in the same manner as in Example 1, the results shown in Table 4 were obtained.

Table 4 Example 14 On a cylindrical aluminum drum with a diameter of 80 mm, a 0.1 μm thick intermediate layer made of a hinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10" was coated by a dipping method.

On top of that, add 1 part by weight of dibrom anthron ``Monolite Red 2YJ and 1 part by weight of polycarbonate resin [Panlite L-1250J] to 1 part by weight of 1,2-dichloroethane.
00 parts by weight and dispersed in a ball mill for 24 hours, and then applied by dipping to form a carrier generation layer with a thickness of 1 μm.

Furthermore, exemplified compound (2) is added as a carrier transport substance.
4.0 parts by weight and 10 parts by weight of polycarbonate resin rZ-200J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) represented by the following structural formula were dissolved in 80 parts by weight of 1,2-dichloroethane, and a solution was applied by the same dipping method to form a film. Thickness: 177mm
A carrier transport layer was formed to prepare an electrophotographic photoreceptor of the present invention.

This electrophotographic photoreceptor is used in an electrophotographic copying machine rU-Bix15.
When the copying machine was attached to a 50MJ and an image was copied, a copy image that was faithful to the 4-stroke image, had high contrast, and had excellent gradation was obtained. Even after repeating this process 50,000 times, a copy image similar to the initial one was obtained.

Comparative Example (3) A comparative photoreceptor (3) was prepared in the same manner as in Example 14, except that a stilbene derivative represented by the following structural formula was used as the carrier transport substance.

When images were copied using this comparative photoreceptor in the same manner as in Example 14, a good copy image was initially obtained as in Example 14, but after around 20,000 copies, fog started to become noticeable and reached 30,000 copies. However, only images with a lot of fog and reduced contrast could be obtained.

Example 15 A 0.1 μm thick intermediate layer made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10" was provided on a conductive support made of a polyester film laminated with aluminum foil.

Next, an exemplary compound (1) is added thereon as a carrier transport substance.
0) A solution prepared by dissolving 4.0 parts by weight of polycarbonate resin "Panlite L-1250J" in 80 parts by weight of 1,2-dichloroethane was dried and then dried.
A carrier transport layer is formed by coating to a thickness of μm.
child .

Furthermore, a carrier generating substance 1 represented by the following structural formula is added thereto.
Exemplary compounds (10 parts by weight and carrier transport substances)
) 1.5 parts by weight of polycarbonate resin "Panlite L-125042 parts by weight was added to 100 parts by weight of 1゜2-dichloroethane, and the resulting solution was dispersed in a ball mill for 24 hours. After drying, the film thickness was 3 μm. An electrophotographic photoreceptor of the present invention was prepared by forming the layers.

This electrophotographic photoreceptor was measured in the same manner as in Example 1, except that the charging voltage was changed to +6 kV, and the results shown in Table 5 were obtained.

Comparative Example (4) A comparative photoreceptor was prepared in the same manner as in Example 15, except that a stilbene derivative represented by the following structural formula was used as the carrier transport substance.

When this comparative photoreceptor was measured in the same manner as in Example 15, the results shown in Table 5 were obtained.

As is clear from the results in Table 5 and above, the electrophotographic photoreceptor of the present invention has extremely superior characteristics in terms of sensitivity and repeated stability compared to the comparative photoreceptor.

Example 16 A 0.1 μm thick intermediate layer made of vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-10J" was provided on a polyester film on which aluminum was vapor-deposited.

On top of that, 1 part by weight of a bisazo pigment represented by the following structural formula as a carrier transport substance and 5 parts by weight of a polycarbonate resin [Panlite L, -1250J O, 1.2-
A carrier generation layer was formed by applying a solution obtained by adding 100 parts by weight of dichloroethane and dispersing it in a ball mill for 24 hours so that the film thickness after drying was 0.3 μm.

Furthermore, exemplified compound (9) is added as a carrier transport substance.
4.0 parts by weight and polycarbonate resin "Panlite K"
-1300J dissolved in 100 parts by weight of 1,2-dichloroethane was coated to form a carrier transport layer such that the film thickness after drying was 16 μm, thereby producing an electrophotographic photoreceptor of the present invention. .

When this electrophotographic photoreceptor was measured in the same manner as in Example 1, the results shown in Table 6 were obtained.

Table 6 Example 17 On a polyester film deposited with aluminum, 0.5 parts by weight of a carrier-generating substance represented by the following structural formula (manufactured by Kyoto Co., Ltd.) and 10 parts of 1,2-dichloroethane were added.
A carrier-generating layer having a thickness of 0.5 μm was formed by applying a solution containing 0 parts by weight and dispersing it in a ball mill for 24 hours.

Furthermore, an exemplary compound (17) is added thereon as a carrier transport substance.
) A solution prepared by dissolving 4.0 parts by weight of polycarbonate resin [10 parts by weight of Panlite K-1300J] in 100 parts by weight of 1,2-dichloroethane was applied to form a carrier transport layer with a thickness of 15 μm. A photoreceptor was created.

When this electrophotographic photoreceptor was measured in the same manner as in Example 1, the results shown in Table 7 were obtained.

Comparative Example (5) Example 17 except that 4.0 parts by weight of a stilbene derivative (A) represented by the following structural formula was used as a carrier transport substance.
A comparison photoreceptor (5) was prepared in the same manner as described above.

When this comparative photoreceptor was measured in the same manner as in the examples, the results shown in Table 7 were obtained.

Table 7 Example 18 A carrier generation layer was formed in the same manner as in Example 11 except that thermometallic τ-phthalocyanine (manufactured by Toyo Ink Co., Ltd.) was used as the carrier generation substance.

Next, 7.5 parts by weight, 6.0 parts by weight, 5.0 parts by weight, and 4.0 parts by weight of the carrier transport substance of Exemplary Compound (14) were added to 10 parts by weight of polycarbonate resin rZ-200 (manufactured by Mitsubishi Gas Chemical Co., Ltd.). part, 3.0 parts by weight to make a film thickness of 20μ
Electrophotographic photoreceptors of the present invention each having a carrier transport layer of m were prepared. The sensitivity (E60°) of these photoreceptors was measured in the same manner as in Example 1. The results are shown in Figure 7.

Comparative Example (6) Example 18 except that a stilbene derivative represented by the following structural formula was used as a carrier transport substance.
A comparative photoreceptor was prepared in the same manner as described above. The results of measurements of these photoreceptors in the same manner as in Example 18 are shown in FIG.

As is clear from the above results, the electrophotographic photoreceptor of the present invention is significantly superior to the comparative photoreceptor in terms of sensitivity and repetition stability, and the sensitivity decreases particularly in the low concentration region of the carrier transport substance. It has extremely excellent properties with little oxidation.

[Brief explanation of the drawing]

1 to 6 are sectional views showing examples of the mechanical structure of the photoreceptor of the present invention, respectively. FIG. 7 is a diagram showing the relationship between the amount of carrier transport substance and sensitivity. ■ Conductive support 2 Carrier generation layer 3 Carrier transport layer 4 Photosensitive layer 5 Intermediate layer 6 ...Layer 7 containing a carrier transport substance...
...Carrier generating substance 8...Protective layer

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising a photosensitive layer containing at least one stilbene derivative represented by the following general formula [I] on a conductive support. General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [In the formula, Ar_1 and Ar_2 represent aryl groups, and Ar
_3 represents an arylene group, and Ar_4 represents a p-phenylene group or a naphthylene group. R_1 and R_2 represent an alkyl group or an aralkyl group. Moreover, these groups may have a substituent. ]