JPH02129648A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having high sensitivity and high durability causing only small fluctuation of light part potential and dark part potential during formation of continuous picture by the exposure and repetitive electrification by incorporating a specified compd. as charge transfer material into the electrophotographic sensitive body. CONSTITUTION:A compd. expressed by the formula I is incorporated into a photosensitive layer of an electrophotographic sensitive body constituted of a laminated photosensitive layer on an electroconductive base body. In the formula I, each Ar1-Ar3 is a (substituted)aryl group, or a heterocyclic group and at least one thereof has a group expressed by the formula II. In the formula II, each R1 and R2 is an H atom, (substituted)alkyl, aryl, or aralkyl group, or a heterocyclic group, wherein each R1 and R2 may form a 5-7 membered ring together with a bonding N atom. Thus, an electrophotographic sensitive body having high sensitivity and high durability causing only small fluctuation of a light part potential and a dark part potential when it is subjected to repetitive electrification and exposure, is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electrophotographic photoreceptors, and more particularly to electrophotographic photoreceptors having a low molecular weight organic photoconductor that provides improved electrophotographic properties.

[Prior Art] In recent years, many electrophotographic photoreceptors using organic compounds as photoconductive materials have been developed.

Most of those that have been put to practical use have a form in which the photoconductor is functionally separated into a charge generating material and a charge transporting material.

However, one major drawback of these electrophotographic photoreceptors has been that they generally have lower durability than inorganic electrophotographic photoreceptors.

Durability is broadly divided into durability of electrophotographic physical properties such as sensitivity, residual potential, charging ability, and image blur, and mechanical durability such as wear and scratches on the photoreceptor surface due to rubbing. Regarding durability in terms of physical properties, it is known that the main cause is deterioration of the charge transporting material contained in the photoreceptor surface layer due to ozone, NOx, etc. generated by corona discharge and light irradiation.

In addition, as an organic charge transport material, US Pat. No. 4150
Hydrazone compounds described in JP-A No. 987, etc., stilbene compounds described in JP-A-58-198043, etc., JP-A-61-295558, JP-A-62-2, etc.
Many proposals have been made, such as the benzidine compound described in JP-A No. 01447, the triphenylamine compound and the triphenylmethane compound described in JP-A No. 60-254045, and the above-mentioned durability is being improved considerably. However, the current situation is that it is still not sufficient.

[Problems to be Solved by the Invention] An object of the present invention is to provide a novel organic photoconductor;
It is an object of the present invention to provide an electrophotographic photoreceptor that eliminates the above-mentioned drawbacks or disadvantages.

[Means and effects for solving the problems] The present invention is an electrophotographic photoreceptor in which a photosensitive layer is laminated on a conductive support, characterized in that the photosensitive layer contains a compound represented by the following general formula (I). Consists of an electrophotographic photoreceptor.

In the formula, Ar1. Ar2 and Ar3 represent an aryl group which may have a substituent or a complex term 6; Arl, Ar
At least one of 2 and Ar3 represents an alkyl group, an aryl group, a 7-ralkyl group, or a heterocyclic group which may have an R co-replacement group, and R1 and R2 together with the bonding nitrogen atom represent a 5- to 7-membered group. may form a ring).

Specifically, in Ar1 to Ar3, examples of the aryl group include groups such as benzene, naphthalene, and anthracene, and examples of the heterocyclic group include groups such as pyrrole, oxazole, pyridine, quinoline, and carbazole;
In, the alkyl group includes groups such as methyl, ethyl, and propyl, the aryl group includes groups such as benzene, naphthalene, and 7-ntra-7, and the heterocyclic group includes pyrrole,
Examples of groups such as oxazole, pyridine, quinoline, and carbazole; examples of aralkyl groups include groups such as benzyl and phenethyl; and examples of the ring formed with the nitrogen atom to which R1 and R2 are bonded include rings such as acridine and carbazole. Can be mentioned.

Examples of substituents include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, alkyl groups such as methyl and ethylpropyl, flukoxy groups such as methoxy and ethoxy, heptalyl groups such as benzene, naphthalene and anthracene,
Heterocyclic groups such as pyrrole, pyridine, carbazole, benzyl.

Examples include 7ralkyl groups such as phenethyl, and
These groups may have a substituent.

Representative examples of the compound represented by general formula (I) are listed below.

Compound Example (1) C Compound Example (4) Compound Example Compound Example (1 Compound Example (12) Compound Example Compound Example (19) Compound Example (20) Compound Example (21) H3 Compound Example [Compound Example Compound Example (38) ) Synthesis Example (Synthesis of Compound Example (38)) 1. Compound Example (41) obtained by nitration of 5-triphenylbenzene by a known method and subsequent reduction Compound Example (42) 5, OOg (14 , 2 mmol) in 40 ml of anhydrous tetrahydrofuran, and while stirring at room temperature, 5.60 g (139
, 5 mmol) was added slowly.

After the addition was complete, the mixture was further stirred at room temperature for 15 minutes.

39.6 g (279 mmol) of methyl iodide was slowly added dropwise, and the mixture was heated and stirred for 3 hours.

After completion of the reaction, the reaction solution was poured into water, the precipitated crystals were washed with methanol, and further purified by recrystallization to obtain the target compound 4.
70g was obtained.

Elemental analysis calculated value (%) Actual value (%) C82,7682,70 H7,647,7O N 9.65 9.64 Compounds other than those on the synthesis side are generally synthesized using the same method.

In a preferred embodiment of the present invention, the compound represented by the general formula (I) is used as a charge transporting material in an electrophotographic photoreceptor in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer.

The charge transport layer in the present invention is preferably formed by applying a solution of the compound represented by the general formula (I) and a binder dissolved in an appropriate solvent and drying the solution.

Examples of the binder used here include polyarylate,
Polysulfone, polyamide, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenolic resin, epoxy resin, polyester, alkyd resin, polycarbonate, polyurethane or copolymer, such as styrene-vitagene copolymer, styrene-acrylic resin, etc. Examples include giant nitrile copolymers, styrene-maleic acid copolymers, and the like.

In addition to such insulating polymers, organic photoconductive polymers such as polyvinylcarbazole, polyvinyl hepthracene, and polyvinylpyrene can also be used.

The blending ratio of this binder and the charge transport material of the present invention is preferably 10 to 500 parts by weight of the charge transport material per 100 parts by weight of the binder.

The charge transport layer is electrically connected to the charge generation layer described below, and has the function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. are doing. In this case, this charge transport layer may be laminated on top of the charge generation layer, or may be laminated below it.However, the charge transport layer may be laminated on the charge generation layer. is desirable.

This charge transport layer has a limit to its ability to transport charge carriers, so it cannot be made thicker than necessary.
For boat fishing, it is 5 to 40 gm, but the preferred range is 10 to 40 gm.
It is 30ILm.

The organic solvent used to form such a charge transport layer varies depending on the type of binder used, or is preferably selected from those that do not dissolve the charge generation layer or underlying subbing layer. Examples of solvents include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetate, methyl ethyl ketone, and cyclohexanone, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide. Sulfoxides, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, aliphatic halogenated hydrocarbons such as methylene chloride, dichloroethylene, carbon tetrachloride, trichlorethylene, or benzene, Aromatic compounds such as toluene, xylene, chlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as a Mayer bar coating method, a blade coating method, a roller coach ink method, or a curtain coating method. For drying, it is preferable to dry to the touch at room temperature and then heat dry.For boat fishing, heat drying should be carried out at a temperature of 30 to 200"C for 5 minutes to 2 hours, either stationary or under ventilation. is preferred.

The charge transport layer of the present invention may contain various additives, such as plasticizers such as diphenyl, m-terphenyl, and dibutyl phthalate, silicone oil, grafted silicone polymers, and various fluorocarbons. surface lubricants, potential stabilizers such as dicyanovinyl compounds and carbazole derivatives, and antioxidants such as β-carotene, Ni complexes, and 1,4-diazabicyclo[2,2,2]octane.

The charge generation layer in the present invention includes an inorganic charge generation material such as selenium, selenium-tellurium, amorphous silicone, etc.
Cationic dyes such as pyrylium dyes, thiapyrylium dyes, azulenium dyes, thiacyanine dyes, and quinocyanine dyes, squbarylium salt dyes, phthalocyanine pigments, anthrone pigments, dibenzpyrenequinone pigments, vilanthrone pigments, etc. Materials selected from organic charge-generating substances such as ringtone pigments, indigo pigments, quinacridone pigments, and azo pigments can be used alone or in combination as a vapor deposited layer or a coating layer.

Among the above-mentioned charge-generating substances, there are a wide variety of azo pigments in particular, and typical structural examples of particularly effective azo pigments will be described below.

The general formula of the azo pigment is shown below, with the central skeleton being A and the coupler portion being cp, where n is 1 or 2. Specific examples are given below.

A-4N-N-Cp)n As a specific example of A.

(R: hydrogen atom, chlorine atom, methoxy group) -CH-
C-@)- (R: hydrogen atom, cyano group) (R: hydrogen atom, cyano group) (x: oxygen atom, sulfur atom R: hydrogen atom, methyl group, chlorine atom) R (x: oxygen atom, Sulfur atom R1 R2: ＼ Cocoon Kudanku A -21 -0-N-0- (R: hydrogen atom, methyl group) [R: alkyl group, -@',, (R=: hydrogen atom R
゛, halogen atom, alkoxy group, alkyl group, nitro group, etc.)] Also, as a specific example of cp.

(R: hydrogen atom, halogen atom, alkoxy group, alkyl group, nitro group, etc. n: 1 or 2) (R: alkyl group, aryl group, etc.) H (R: methyl group, ethyl group, propyl group, etc.) (R1 , R2: hydrogen atom, halogen atom alkoxy group 2
Examples include an alkyl group, a nitro group, etc. (n: 1 or 2).

The central skeleton A and the coupler Cp form a pigment serving as a charge-generating substance by appropriate combination.

The charge generation layer can be formed by dispersing the charge generation substance described above in a suitable binder and coating it on a support, or by forming a vapor deposited film using a vacuum evaporation device. .

The binder can be selected from a wide range of insulating resins and organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene.

Preferably polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol,
Examples include polyvinylpyrrolidone.

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-dimethylacetamide. , sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, and aliphatics such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene. Halogenated hydrocarbons or aromatic compounds such as benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating method, spray coating method, spinner coating method, bead coating method,
This can be carried out using a coating method such as a Mayer bar coating method, a blade coating method, a roller coating method, or a curtain coating method.

For drying, it is preferable to dry to the touch at room temperature and then heat dry.
It is preferable to carry out the process at a temperature of 5 minutes to 2 hours at a temperature of 50°C, either stationary or under ventilation.

The charge generation layer contains as much of the organic photoconductor as possible in order to obtain sufficient absorbance and a thin film layer 1, for example 5 gm, in order to inject carriers into the charge transport layer within the lifetime of the generated charge carriers. Below, preferably 0.01 to 1
A thin film layer having a thickness of μm is desirable.

A photosensitive layer having such a laminated structure of a charge generation layer and a charge transport layer is provided on a support having a conductive layer. As the support having a conductive layer, the support itself is conductive, such as aluminum, aluminum alloy, copper,
Zinc, stainless steel, vanadium, molybdenum, chromium 1
, titanium, nickel, indium, gold, platinum, etc., and has a layer formed by vacuum evaporation of aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. conductive particles (e.g., aluminum powder, titanium oxide, tin oxide,
Supports such as zinc oxide, carbon black, silver particles, etc.) coated on plastic or the above-mentioned conductive support with a suitable binder, supports made of plastic or paper impregnated with conductive particles, plastics containing conductive polymers, etc. can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive support and the photosensitive layer.

The subbing layer can be formed from casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin aluminum oxide, etc. .

The thickness of the undercoat layer is 0.1 to 5 ILm, preferably 0.5 to 5 ILm.
3 m is appropriate.

When using a photoreceptor in which a conductive support, a charge generation layer, and a charge transport layer are laminated in this order, the charge transport compound in the present invention has hole transport properties, so the surface of the charge transport layer must be negatively charged. When exposed to light after charging, holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, and then reach the surface and neutralize the negative charge, causing a decrease in surface potential and a gap between the exposed area and the unexposed area. Electrostatic contrast occurs.

During development, it is necessary to use positively charged toner.

In another specific example of the present invention, the above-mentioned azo pigment or the pyrylium dyes, thiapyrylium dyes, selenapyrylium dyes, and benzene dyes disclosed in U.S. Pat. Pyrylium dye, benzothiapyrylium dye 1
, naphthopyryllium dye, naphthothiapyrylium dye, and other photoconductive pigments and dyes can also be used as sensitizers.

In another specific example, a eutectic complex of a pyrylium dye and an electrically insulating polymer having an alkylidene diarylene moiety, such as disclosed in US Pat. No. 3,684,502, can be used as a sensitizer. This eutectic complex is, for example, 4-[4-bis(2-chloroethyl)aminophenyl]
-2,6-cyphenylthiapyrylium verchlorate and poly(4,4°-isobropylidene diphenylene carbonate) are mixed in a halogenated hydrocarbon solvent such as dichloromethane, chloroform, carbon tetrachloride, 11-dichloroethane, 1. 2-dichloroethane, 1 , 1 , 2-
After dissolving in 1,1 chloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene, etc., a nonpolar solvent such as hexane, octane, decane, 2,
2.4-) Obtained as a particulate eutectic complex by adding lynchylbenzene, ligroin, etc.

The electrophotographic photoreceptor in this specific example includes styrene-butadiene copolymer, silicone resin, vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer polyvinyl butyral, 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 in electrophotographic copying machines but also in a wide range of electrophotographic applications such as laser beam printers, CRT printers, and electrophotographic plate making systems.

The electrophotographic photoreceptor of the present invention has the advantage of high sensitivity and small fluctuations in bright area potential and dark area potential when repeatedly charged and exposed.

[Example] Example 1 5 g of a disazo pigment represented by the following structural formula was mixed with butyral resin (
butyralization degree 63 mol%) 2g cyclohexanone 1
A coating solution was prepared by dispersing it in a sand mill for 24 hours with a solution dissolved at 00 mM.

This coating liquid was applied to an aluminum sheet with a dry film thickness of 0.2 JLm.
A charge generation layer was formed by coating with a Maya bar so that the charge generation layer was formed.

Next, 10 g of Compound Example (38) as a charge transport material and 10 g of polycarbonate (average molecular weight 20,000) were dissolved in 70 g of chlorobenzene, and this solution was applied onto the charge generation layer using a Mayer bar.

A charge transport layer having a dry film thickness of 20 JLm was formed to produce an electrophotographic photoreceptor.

The electrophotographic photoreceptor thus prepared was corona-charged at 5 KV using a static copying paper tester Model-SP-428 manufactured by Kawaguchi Electric Co., Ltd., held in a dark place for 1 second, and then exposed to light at an illuminance of 20 lux. , the charging characteristics were investigated.

As for charging characteristics, the surface potential (Vo) and the exposure amount (E 1/2) required to attenuate the potential (Vl) to 1/2 when dark decayed for 1 second were measured.

Furthermore, in order to measure the fluctuations in dark area potential and bright area potential during repeated use, the electrophotographic photoreceptor prepared in this example was attached to the photosensitive drum cylinder of a Canon PPC copier NP-3525. , 5,000 copies were made with the same machine, and the dark area potential (initial and after 5,000 copies) was
Variations in the bright area potential (Vo) and light area potential (Vo) were measured.

ft8, initial VD and VL are -700V and 200V respectively
It was set so that

For comparison, a similar electrophotographic photoreceptor was prepared using a compound having the structure shown below in place of the charge transport material used in Example 1 as a charge transport material, and the electrophotographic properties were similarly measured.

Show the results.

Example 1 -740 -725 2.0 Comparative example -
730-6209,4 V5 V Example I Vo -700-685VL -2
00-215 Comparative example VD -700-590 VL -200-315 As is clear from the above results, when the charge transport material specified in the present invention is used, it has good sensitivity and there is no potential fluctuation during durability. It turns out that there are few.

Examples 2 to 15 In each of these Examples, instead of the charge transport compound example (38) used in Example 1, compound examples (6), (8), and (10) were used.
), if), (t4), (20), (21), (22)
, (24), (25), (27), (29), (3o)
An electrophotographic photoreceptor was prepared in the same manner as in Example 1, using (34) and a pigment having the following structural formula as a charge generating substance, but with the other conditions being the same as in Example 1.

The electrophotographic properties of each photoreceptor were measured in the same manner as in Example 1. Show the results.

(l 1) , 4 , 2 , 8 , 7 , 6 , 7 , 8 , 0 , 9 , 6 Initial 200 ・ 70.01.5 685 1.7 700 1.7 700 1.8 After 5,000 sheets Example 16 An ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 mJL of water) was coated on an aluminum cylinder by a blade coating method to form a subbing layer with a dry film thickness of 1 lumen.

Next, 10 g of a charge generating substance represented by the following structural formula.

5 g of butyral resin (butyralization degree: 63 mol %) and 200 g of cyclohexanone were dispersed for 48 hours using a ball mill disperser. This dispersion was applied onto the previously formed undercoat layer using a blade coating method, and the dry film thickness was 0.
．． 15) A charge generation layer of hm was formed.

Next, 10 g of compound example (35) and 10 g of polymethyl methacrylate (average molecular weight 50,000) were added to 70 g of chlorobenzene.
g and applied on the previously formed charge generation layer by a blade coating method to form a charge transport layer with a dry film thickness of 19 ILm.

A corona discharge of 15 KV was applied to the electrophotographic photoreceptor thus prepared. The surface potential at this time was measured (initial potential Vo), and the surface potential after this photoreceptor was left in a dark place for 1 second was measured.

Sensitivity is the exposure amount (El/2, microjoule/cm2) required to attenuate the potential v1 after dark decay to 1/2.
It was evaluated by measuring.

At this time, the light source was a gallium/aluminum/arsenic ternary semiconductor laser (output: 5 mw, oscillation wavelength: 780 nm).
m) was used. Show the results.

Vo knee 710V Vl knee 700Vel/
2:2.5 microjoules/cm ”Next, the photoreceptor was subjected to LBP using a laser beam printer (manufactured by Canon Corp., LBP-CX), which is a reversal development type electrophotographic printer equipped with the same semiconductor laser. An actual image forming test was conducted in place of the -CX photoreceptor.

The conditions were: surface potential knee 700 V after negative charging, surface potential knee 150 V after image exposure (exposure amount 2.0 microjoules/cm2), transfer potential: +70 OV, developer polarity: negative polarity, process speed. :50mm/sec,
Development conditions (development bias) knee 450V, image exposure scanning method: image scan, - exposure before next charging = 50 u
The entire surface was exposed to red light at x, sec, and image formation was carried out by line scanning a laser beam in accordance with character signals and image signals, and good prints were obtained for both characters and images. Furthermore, when 3,000 images were printed continuously, stable and good prints were obtained from the initial stage up to 3,000 sheets.

Example 17 3 g of 4-(4-dimethylaminophenyl)-2,6-siphenylthiapyrylium perchlorate and compound example (
18) was mixed with 100 ml of a toluene (50 parts by weight)-dioxane (50 parts by weight) solution of polyester (Polyester Adhesive 49000, manufactured by DuPont) and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet using Mayer/S- so that the film thickness after drying was 157 Lm.

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

vo knee 725V Vl knee 700Vel/
2: 4.2 sentences ux, sec Handling-1 VD Knee 700V VL, Knee 200Vi1 Kukokyatsu Vn Knee 670V VL Knee 230V Example 1
8 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and poly(4,4
°-isobropylidene diphenylene carbonate) 3g
was sufficiently dissolved in 200 mJl of dichloromethane, and then 100 mJ1 of toluene was added to precipitate the eutectic complex. After filtering this precipitate, dichloromethane was added to redissolve it, and then 100 mfL of n-hexane was added to this solution to obtain a precipitate of a eutectic complex.

5 g of this eutectic complex was added to 95 ml of a methanol solution containing 2 g of polyvinyl butyral, and dispersed using a ball mill disperser for 6 hours. This dispersion was applied onto an aluminum plate having a casein layer using a Mayer bar to form a charge generation layer so that the film thickness after drying was 0.4 gm.

Next, a cover layer of a charge transport layer was formed in the same manner as in Example 1 except that Compound Example (13) was used on the charge generation layer.

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

vo knee 740V Vl knee 715Vel/
2: 3.5 sentences ux, sec 5-1 Vo Knee 700V VL Knee 200V11 Kusara Katsuyuki Vo Knee 670V VL Knee 225V Example 1
9 An ammonia aqueous solution of casein (described above) was applied on an aluminum plate using a Mayer bar to form a subbing layer with a dry film thickness of Igm. The charge transport layer and charge generation layer of Example 7 were sequentially laminated thereon, and an electrophotographic photoreceptor was prepared in the same manner as in Example 7 except for the layer structure, and the charging properties were the same as in Example 7. was measured. However, the charging polarity was set to 10. Show the results.

vo: +700V Vl: +680Vel
/2: 4.11ux, sec Example 20 Soluble nylon (6-66-610-12
A 5% methanol solution of a quaternary nylon copolymer) was applied to form a subbing layer having a dry thickness of 0.51 Lm.

Next, 5 g of the pigment having the following structural formula was added to 95 g of tetrahydrofuran.
The mixture was dispersed for 200 hours using a sand mill disperser in mJl.

Next, a solution prepared by dissolving 5 g of Compound Example (16) and 10 g of bisphenol Z type polycarbonate (viscosity average molecular weight: 30,000) in 30 mM of chlorobenzene was added to the dispersion prepared above, and the mixture was further dispersed for 2 hours using a sand mill. This dispersion was applied onto the previously formed subbing layer using a Mayer bar so that the film thickness after drying would be 20 gm, and then dried.

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

vo knee 720V Vl knee 700Vel
/2:3.5J1ux, see [Effects of the Invention] The electrophotographic photoreceptor containing the specific compound of the great invention as a charge transport substance has high sensitivity, and also has high sensitivity in bright areas during continuous image formation by edge-reversing charging exposure. It is an electrophotographic photoreceptor with excellent durability and small fluctuations in potential and dark area potential.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula (I). General formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the formula, Ar_1, Ar_2 and Ar_3 represent an aryl group or a heterocyclic group which may have a substituent, and Ar_
At least one of 1, Ar_2, and Ar_3 is a ▲ mathematical formula, chemical formula, table, etc. ▼ group (wherein R_1 and R_2 are hydrogen atoms, alkyl groups that may have substituents, aryl groups, aralkyl groups, or represents a heterocyclic group, and R_1 and R_2 together with the nitrogen atom to which they are bonded represent 5 to 7
may form a membered ring).