JPS61210363A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body high in sensitivity and potential stability at the time of repeated electrostatic charging and destaticizing by incorporating a specified compd. as a charge transfer material in a photosensitive layer. CONSTITUTION:The functionally separated laminated type photosensitive layer is composed of the charge transfer and a charge generating layer, and this charge transfer layer is formed by coating a conductive substrate or the charge generating layer with a soln. prepared by dissolving in a proper solvent a binder resin, such as polyarylate resin, polysulfone resin, phenol resin, epoxy resin, polyester-urethane, copolymers of styrene-butadiene or styrene-maleic acid, and a charge transfer material represented by the formula, and drying it. In the formula R1 is optionally substd. alkyl or such aralkyl; R2 and Ar2 are each optionally substd. aryl or a heterocyclic group; Ar1 is optionally substd. arylene, and n is 1 or 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly, to an improved electrophotographic photoreceptor.
The present invention relates to an electrophotographic photoreceptor having a low-molecular organic photoconductor that provides fc electrophotographic properties.

[Conventional technology]

Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are known as photoconductive materials used in electrophotographic photoreceptors. These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, and quickly dissipating all charge when exposed to light or light. Although it has advantages, it also has various disadvantages. The problem is that selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dirt, and pressure.
In particular, when the ambient temperature exceeds 40° C., crystallization becomes significant, resulting in drawbacks such as a decrease in chargeability and the appearance of white spots on images. Cadmium sulfide photoreceptors are stable in humid environments and do not exhibit friendly sensitivity, and zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal. The sensitizing dye suffers charging deterioration due to corona charging and photobleaching due to exposure light, so it has the disadvantage that it is not stable for a long period of time and cannot provide subsequent images.

On the other hand, six organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior in terms of film formability and light weight compared to the inorganic photoconductive materials mentioned above. However, it has been difficult to put them into practical use to date, and the reason for this is that sufficient film-forming properties have not yet been obtained, and inorganic photoconductive materials have been lacking in terms of sensitivity, durability, and stability against environmental changes. It was an inferior rounding.

In addition, hydrazone compounds disclosed in US Pat. No. 4,150,987, triarylpyrazoline compounds described in US Pat. No. 3,837,85i, etc.,
Low-molecular organic photoconductors such as 9-steryl anthracene compounds described in JP-A-94828 and JP-A-51-94829 have been proposed. By appropriately selecting the binder used, such low-molecular-weight organic photoconductors can overcome the drawbacks of film-forming properties that have been a problem in the field of organic photoconductive polymers. It cannot be said that the sensitivity is sufficient.

For this reason, in recent years, an FC laminated structure has been proposed in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer. Using this laminated structure as a photosensitive layer, nine electrophotographic photoreceptors can now be improved in terms of sensitivity to visible light, charge retention, surface strength, etc. Such electrophotographic photoreceptors are disclosed, for example, in US Pat. No. 3,837,851 and US Pat. No. 3,871,882.

However, with conventional fcYL photoreceptors that use low-molecular organic photoconductors in the charge transport layer, the sensitivity is not always sufficient, and the bright area potential does not change when repeatedly charged and exposed. There is a large fluctuation in the dark potential which needs to be improved.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor that overcomes the above-mentioned drawbacks or disadvantages.

Another object of the invention is to provide a novel organic photoconductor.

Another object of the present invention is to provide a novel charge-transporting material in a laminated photosensitive layer which is functionally separated into a charge-generating layer and a charge-transporting layer.

[Ninth way to solve the problem]

This object of the present invention is achieved by an electrophotographic photoreceptor having the following configuration.

That is, the present invention uses a compound represented by the following general formula in the photosensitive layer! 1. An electrophotographic photoreceptor containing as a cargo transporting substance.

General formula (wherein R1 represents an alkyl group or an aralkyl group which may contain a substituent, R2 and Arz represent an aryl group or a heteroaromatic ring which may have a substituent, Ar,
represents an arylene group which may have a substituent, and n represents an integer of 1 or 2. ).

The present invention will be explained in detail below.

Examples of the electrophotographic photoreceptor of the present invention include one in which the photosensitive layer is made of a charge generating material and a charge transporting material, but preferably the photosensitive layer is functionally separated into a charge generating layer and a charge transporting layer to transport charges. An example is a layered type in which a charge transporting substance is contained in the layer. It is also possible to further improve the sensitizing effect by incorporating a charge transporting substance into the charge generation layer.

In the present invention, the charge transport layer is formed by applying a solution prepared by dissolving a charge transport substance and a binder in a suitable solvent onto a charge generating layer on a conductive substrate, and drying the solution. It is preferable that vomiting occurs.

The charge transport material used in the present invention is a compound represented by the following general formula, which is excellent in the electrophotographic photoreceptor of the present invention, and has effects such as potential stabilization during 7'c @ degree and 9 repeated band discharges. It is something that serves as a source of protection.

In the general formula, R1 represents an alkyl group such as methyl, ethyl, propyl, butyl, or an aralkyl group such as benzyl or phenethyl, and R2 and Arz represent an aryl group such as phenyl or naphthyl, or a heteroaromatic ring such as pyridyl or quinolyl. represents. MakuAr is phenylene.

Indicates an arylene group such as naphthylene. The alkyl group, aralkyl group, aryl group, heteroaromatic ring, and arylene group include alkyl groups such as methyl, ethyl, propyl, butyl, alkoxy groups such as methoxy, ethoxy, and propoxy;
It may be substituted with a halogen atom such as chlorine, bromine, or iodine, or an amino group substituted with an alkyl group or an aralkyl group.

Further, n represents an integer of 1 or 2.

Representative examples of compounds represented by the above general formula are listed below.

Binders used with compound series charge transport materials include polyarylate resins, polysulfone resins, polyamide resins, acrylic resins, acrylonitrile resins, methacrylic resins, vinyl chloride resins, vinyl acetate resins, phenolic resins, epoxy resins, polyesters. Urethane resins include copolymer resins containing two or more repeating units of these resins, such as styrene-butadiene copolymers, styrene-7/I)ronitrile copolymers, styrene-maleic acid copolymers, etc. can. In addition to such insulating polymers, polyvinylcal/4yl, yN! j Organic photoconductive polymers such as vinylanthracene and polyvinylpyrene can also be used.

The blending ratio of the binder and the compound is preferably 10 to 500 parts by weight of the compound per 100 parts by weight of the binder in terms of electrophotographic properties and film formability.

The charge transport material is electrically connected to the charge generation layer described above, and has the function of receiving and receiving specific charge carriers injected from the charge generation layer in the presence of an electric field, and transporting these charge carriers to the other side. are doing. At this time, this charge transport layer may be laminated on or under the charge generation layer. However, it is preferable that the charge transport layer is laminated on the charge generation layer, since the charge transport layer also serves as a coating protection effect.

Since this charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Typically it is 5 microns to 30 microns, with a preferred range of 8 microns to 20 microns.

The organic solvent used when forming such a charge transport layer is
It is preferable to select a binder that differs depending on the type of binder used, or one that does not dissolve the charge generation layer or the above-mentioned subbing layer. Specific WaS agents include alcohols such as methanol, ethanol, and ingropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, amides such as N,N-dimethylformamide, N,N-tumethylacetamide, and dimethyl Sulfoxides such as sulfoxide, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, aliphatic halodanization of chloroform, methylene chloride, nochloroethylene, carbon tetrachloride, trichlorethylene, etc. Hydrocarbons or aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using coating methods such as the Mayer-Barcoin method, f-lade coating method, roller coating method, and curtain coating method.

For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying is performed at a temperature of 30°C to 200'C.
It can be carried out stationary or under blown air for times ranging from minutes to 2 hours.

The charge transport layer of the present invention can contain various additives. Such additives include diphenyl, diphenyl chloride, 0-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dilauryl thioglopionate. , 3,5-dinitrosalicylic acid, various fluorocarbons, and the like.

The charge generating layer used in the present invention includes selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, pyrylium, thiapyrylium, azulenium dye, 7taC1 cyania type M material, anthoanthrone pigment, dibenzpyrenequinone pigment, and pyranthrone pigment.

Trisazo pigment, nosazo pigment, azo pigment, in-novo pigment, quinacridone pigment, theamianine, asymmetric quinocyanine, quinocyanine squaric acid methine dye, thioindigo dye, β-type steel phthalocyanine or amorphous silicon described in JP-A-54-143645. A separate vapor-deposited layer or resin-dispersed layer, which is not particularly limited, may be used, but is not particularly limited, and is selected from materials that can be used as charge-generating materials.

The charge generation layer can be formed by dispersing the above-mentioned charge generation substance in a suitable binder and coating it on the substrate, or can be obtained by forming a vaporized film using a vacuum vapor deposition apparatus. can. Binders that can be used to form the charge generating layer by coating can be selected from a wide range of insulating resins, including organic photoconductive polymers such as IJ-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene. You can choose from. Preferably, polyvinyl butyral, polyarylate (such as a degenerated product of hisphenol A and phthalic acid), polycargonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyrinone, cellulose Insulating resins such as polyvinyl alcohol, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone can be mentioned. The resin contained in the charge generation layer is suitably 80% by weight or less, preferably 40% by weight or less. Organic solvents used during coating include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and amides such as N,N-dimethylformamide and N,N-tumethylacetamide. sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, nooxane, and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, and fats such as chloroform, methylene chloride, nochloroethylene, carbon tetrachloride, and trichloroethylene. Group halodanized hydrocarbons or aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

Komoko uses dip coating method, spray coating method, spinner coating method, bead coating method,
The coating can be carried out using a coating method such as a Mayer coating method, a blade coating method, a roller coating method, or a curtain coating method.

The charge generation layer contains as much of the organic photoconductor gold as possible in order to obtain sufficient absorbance, and also contains a thin film layer, an array tIi, in order to shorten the range of the generated charge carriers.
It is preferable to use a thin film layer with a thickness t of 5 microns or less, preferably 0.01 micron to 1 micron. This means that most of the incident light is absorbed by the charge generation layer and many charge carriers are generated. This is due to the fact that it is necessary to inject the generated charge carriers into the charge transport layer without being deactivated by recombination or trapping.

A photosensitive layer having such a laminated structure of a charge generation layer and a charge transport layer is provided on a substrate having a conductive layer. Substrates having a conductive layer include those in which the substrate itself is conductive;
The materials are aluminum, aluminum alloy, copper, zinc, stainless steel, pananoum, molybdenum, chromium, titanium,
Nickel, indium, gold, platinum, etc. can be used, and in addition, glass materials (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluorinated ethylene, etc.), conductive particles (e.g. carbon black, silver particles, etc.), coated on the plastic with a suitable binder, A substrate impregnated with conductive particles t'' glasstic paper, a plastic having a conductive polymer, etc. can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive layer and the photosensitive layer. Subbing layer, casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
It can be formed from acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymer & nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc.

The thickness of the undercoat layer is preferably 0.1 to 5 microns, and 0.5 to 3 microns for the case. When using , the compound has hole-transporting properties, so! The surface of the charge transport layer needs to be negatively charged, so when it is exposed to light after being charged, positive holes are generated in the charge generation layer in the exposed area and injected into the charge transport layer, which then reach the surface and neutralize the negative charges, increasing the surface potential. Attenuation occurs and electrostatic contrast occurs between the exposed area and the unexposed area. During development, it is necessary to use a positively charged toner, contrary to the case where an electron transport material is used.

In another embodiment of the present invention, the above-mentioned nosazo pigments or pyrylium dyes, thiapyrylium dyes, selenapyrylium dyes, and benzopyrylium dyes disclosed in U.S. Pat. No. 3,554,745, U.S. Pat. , benzothiapyryllium dye, naphthopyryllium dye, naphthothiapyrylium dye, and other photoconductive pigments and dyes can also be used as sensitizers.

In another specific series, a eutectic complex of a bicarbonate dye and an electrically insulating polymer having an alkylidenoarylene moiety as disclosed in U.S. Pat. No. 3,684,502 can also be used as a sensitizer. . This eutectic complex is composed of, for example, 4-[4-bis-(2-chloroethyl)aminophenyl)-2,6-'' dibutenylthiapyrylium perchlorate and poly(4,4'-ingropyridenophenyl V). carbonate) with a helogonized hydrocarbon solvent (e.g., dichloromethane, chloroform, carbon tetrachloride,
．． 1-dichloroethane, 1,2-dichloroethane, 1,
1.2-) dichloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene) and then add a non-polar solvent (e.g. hexane, octane, decane, 2,2.4-), 1J Obtained as a particulate eutectic complex by adding methylbenzene and ligroin. Electrophotographic photoreceptors in this specific series include sterene-butadiene co-4 remer, silicone resin, vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, polyvinyl! Tyral, polymethyl methacrylate, poly-N-butyl methacrylate,
Polyesters, cellulose esters, etc. can be contained as a binder.

The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser grinters, CRT printers,
It can also be widely used in electrophotographic application fields such as electrophotographic plate making systems.

According to the present invention, it is possible to provide a highly sensitive electrophotographic photoreceptor, and it has the advantage that the fluctuation in bright area potential and dark area potential when repeated charging and exposure ff: 7 times is small. Examples] The present invention will be described below in accordance with the examples.

3 shows a composition sequence of a charge transport material represented by the above general formula.

Synthetic gas E-1 synthetic stirring system, cooling pipe with calcium chloride pipe, thermometer,
Set all the gas inlets, weigh out 120 m of DMF and 240 d of benzene in a flask, and add 6.69' of sodium hydride (50% mineral oil) while adding nitrogen gas to the flask.
Next K4-(N,N-)fk7g = 38.91 diethylpenzyl phosphonate 42.91 diethylpenzyl phosphonate were added in this order and stirring was continued at room temperature. Bubbles are generated and the liquid temperature gradually rises, then cooled with water and controlled at 40℃. After the generation of bubbles had ceased, the mixture was stirred for 30 minutes, and then the temperature was gradually raised to reach the reflux temperature, after which the mixture was completely refluxed for another 1 hour. During reflux, multiple pale yellow precipitates were formed. The mixture was cooled to room temperature, and 11 ml of tomoduki water was added to separate the oil layer, and the aqueous layer was extracted three times with benzene 300. The previously separated oil layer and benzene extract were combined, washed with water, and dried. After drying, the liquid was concentrated, ethanol was added to reconsolidate, and further purification was performed using MEK-ethanol system to obtain the target compound E-1. Contains 37.8 g
(Yield 72%) Elemental analysis value Cf (N Theoretical value 88.38 6.71 4.91 Measured value
88.41 6.73 4.86 Other compounds can be easily synthesized similarly by condensing a given aldehyde and diethylarylmethylphosphonate in the presence of sodium hydride. Note that under the above conditions, the contamination of 0111 is extremely small. 1. Beta fine-tuned phthalocyanine manufactured by Toyo Ink Mfg. Co., Ltd. (trade name: Lionol Blu@NCB Taner) f
After sequentially refluxing in water, ethanol and benzene, it was purified by filtration to give nine pigments 7I; polyester resin (trade name: Polyester Adhesive 49,000, manufactured by Dupo Co., Ltd., solid content 20%) 14Ii; toluene 35I; dioxa 73
A coating solution was prepared by mixing the mixture with 51 and dispersing it in yN-Lumil for 6 hours. This coating solution was applied onto an aluminum sheet using a Mayer coating to a dry film thickness of 0.5 microns to form a charge generation layer.9.

Next, the exemplified compound E-31 (
71 and polycargenate resin (manufactured by Kinjin Kasei Co., Ltd., trade name [Panlite 115UOJ) 719, were stirred and dissolved in a mixed solvent of tetrahydrofuran 3519 and chlorobenzene 35y. The film was coated with Mayer Par to a dry film thickness of 15 microns, thereby preparing an entire electrophotographic photoreceptor having a photosensitive layer having a two-layer structure.

The electrophotographic photoreceptor produced in this way was manufactured by Kawaguchi Electric Co., Ltd.
Corona charging was carried out statically at 1.3 kV using a Seikime copying paper tester Model-8P-428, and 1.5 kV was applied in a dark place.
After holding for a second, it was exposed to light at an illuminance of 5 bux and the charging characteristics were examined.

As for the charging characteristics, measure the exposure amount (E) necessary to attenuate the surface potential (VO) and the potential (V+) to 'A' when exposed to the dark decay formula for 1 second.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential during repeated use, nine photoreceptors were prepared in this example and were installed in the cylinder for the sensory drum of the PPC copying machine NP-150Z manufactured by Gold Canon Co., Ltd. 50,000 copies were made using the same machine with the sticker attached, and the fluctuations in the bright area potential (vL) and dark S potential (VD) were measured between the initial stage and after 5000 copies were made.

Comparative Sample 1 was prepared in exactly the same manner using a stilbene compound having the following structural formula in place of Exemplified Compound E-3, and measured in the same manner.

The results are shown below.

In each of Examples 2 to 1, Exemplified Compound E-3 was replaced with Exemplified Compound E-3 as the charge transport compound used in Example 1.
1, E-2, E-4, E-6゜E-7, E-9, E-1
0,E-11,E-13゜g-14,E-161-19
, E-21, E-23, and E-25'i, and the following pigment was used as the charge-generating substance.

The electrophotographic characteristics of each photoreceptor were measured in the same manner as in Example 1. The results are shown below.

Eμ　　　　vDv.

Example Exemplary compound (Mux-sec) (-gelt) (-gelt) Initial performance after 5oooo sheets durability vD (-1 sting) v5 (-crossing) v, (-sha υ ret) ■ , (-Clam Q Reto) Example 17 4-(4-trimethylaminophenyl)-2,6-siphenylthiapyrylium-chlorate 3.9 and the above-mentioned exemplified compound (E-8)! Ml is toluene (50)-dioxane (50) of polyester (Polyester Adhesive 49000: De Bonn Publishing)! The mixture was mixed with Liquid 100- and dispersed in a Gale mill for 6 hours. This dispersion was coated onto an aluminum sheet using a Mayer parr so that the film thickness after drying was 15 microns.

Experimenting with the electrophotographic characteristics of the photoreceptor created in this way
It was measured in the same manner as ll. The results are shown below.

Vo: -620 melt V,: -600 melt 1g4: 2. @&xtsec Initial VD: -705 Golt VL: -75 Gelt VD after 5oooo sheets of durability: -615 Gelt VL: -115 Volts Example 18 Ammonia aqueous solution of casein (Casein 1
1.2. f, 28qb ammonia water III, water 222+
d) was applied with Mayer Par and dried to form an adhesive layer with a thickness of 1 micron.

Next, 5 g of a disazo pigment having the following structure and a butyral resin (degree of butyralization of 63 mol) were dispersed together with 21"ft of ethanol and 95 m of K?I liquor. After that, it was coated on the adhesive layer and the thickness of the film after drying was Forms a charge generation layer with a diameter of 0.4 microns.

Next, a solution of the above-listed compound (F, -12) dissolved in 31i and poly-4,4'-dioxydiphenyl-2,2-pro/4-cardenate (viscosity average molecular weight 30,000) 51t dichloromethane 150- An electrophotographic photoreceptor was prepared by coating and drying the mixture on the charge generation layer to form a charge transport layer with a thickness of 11 microns.9.

The electrophotographic properties of the electrophotographic photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown below.

Vo: -600 volts V, : -580 volts Ey, : 2.7 &x1sec Initial VD: -705 melt VL: -70 melt VD after 50,000 sheets durability: -620 volts VL: -110 volts 19 Surface is clean Tight 0.2cm thick molybdenum plate (substrate)
It was fixed at a predetermined position in the glow discharge deposition tank. Next, the inside of the tank was evacuated to a vacuum level of about 5×10 torr. After 7, increase the input voltage of the heater and raise the molybdenum plate temperature to 15
After the temperature was stabilized at 0° C., hydrogen gas and silane gas (15 volumes per hydrogen gas) were introduced into the tank, and the gas flow rate and the main pulp of the deposition tank were adjusted to stabilize the temperature at 0.5 torr. Next, 5 MHz high-frequency power was applied to the induction coil to generate a glow inside the coil in the tank with an input power of 30 W. After growing an amorphous silicon film on the substrate under the above conditions and maintaining the same conditions until the film thickness reached 2μ, the glow emission was stopped. After that, turn off the heating heater and high frequency power supply, wait for the substrate temperature to reach 100℃, close the outflow pulp of hydrogen gas and silane gas, and temporarily reduce the inside of the tank to below 1 o''''5 torr and return it to atmospheric pressure after Tomono. Take out your friends. Next, a charge transport layer was formed on this amorphous silicon layer in exactly the same manner as in Example 1, except that the listed sample E-25'E was used as a charge transport layer.

The photoreceptor thus obtained was placed in a band tmm optical experimental apparatus, charged with corona at θ6 kV, and immediately irradiated with a light image. The light image is illuminated through a transparent test chart using a tungsten lamp light source. Immediately thereafter, an e-chargeable developer (
A good toner image was obtained on the photoreceptor surface by cascading the toner (containing toner and carrier) onto the photoreceptor surface.

Example 20 3 g of 4-(4-dimethylaminophenyl)-2,6-nophenylthiavirillium perchlorate and #IJ (
After sufficiently dissolving 4,4'-4sopropylidene diphenylene cargoonate) 3I in dichloromethane 200-,
Add 1010Os of toluene to precipitate the eutectic complex. This precipitate was separated and remelted with dichloromethane, and then 100 d of n-hexane was added to this solution to obtain a precipitate of a eutectic complex.

This eutectic complex 5N1c polyvinyl butyral 2y was added to a methanol bath solution 95- containing it and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum plate having a casein layer f using a Mayer bar so that the film thickness after drying was 0.4 microns to form a charge generation layer.

Next, a cover layer of a charge transport layer was formed on this charge generation layer in exactly the same manner as in Example 1 except that Exemplified Compound E-26 was used.

The electrophotographic characteristics of the photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown below.

Vo: -580 Gault Vl: -555 Volt E: 2.8Asx-sec A Initial VD: -670 Gault VL: -70 Volt VD: -570 Gault VL: -120 & Gault Example 21 Common used in Example 20 Add the same crystal complex 5Ii to 150 ml of a tetrahydrofuran solution of the above-mentioned exemplified compound (E-22) 5#t polyester (Polyester Adhesive 49000: Du 4), and mix thoroughly with stirring. This solution was applied onto an aluminum sheet using a Mayer bar so that the film thickness after drying was 15 μm.

The electrophotographic properties of this photoreceptor were measured in the same manner as in Example 1. The results are shown below.

Vo: -630 volts Vl: -620 volts 12'3.7&x-sec A Initial VD: -720 volts VL: -90 volts VD after 50,000 sheets of durability: -640 volts VL: -150 TIe lts [Effects of the invention] As is clear from the above, the present invention provides an electrophotographic photoreceptor that has higher sensitivity and higher potential stability during repeated charging and discharging than conventional ones by containing a specific compound as a charge transport substance in the photosensitive layer. Allows you to serve your friends.

Claims (3)

[Claims] (1) An electrophotographic photoreceptor characterized in that the photosensitive layer contains a compound represented by the following general formula as a charge transport substance. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R_1 represents an alkyl group or an aralkyl group that may have a substituent, and R_2 and Ar_2 are an aryl group or an aralkyl group that may have a substituent. represents a heteroaromatic ring,
Ar_1 represents an arylene group that may have a substituent,
n represents an integer of 1 or 2. ) (2) The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer is a laminated type consisting of a charge generation layer and a charge transport layer, and the charge transport layer contains the above compound. (3) The electrophotographic photoreceptor according to claim 2, wherein the charge generation layer also contains the above compound.