JPS59168452A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body high in sensitivity and small in variation of the potentials in the light and the dark in undergoing repeated cycles of charging and exposure by using a specified compd. as a charge transfer substance. CONSTITUTION:An electrophotographic sensitive body is formed by laminating on a conductive substrate an electrostatic charge transfer layer contg. a hydrazone compd., such as formula III or IV, selected from ones represented by general formulae I and II (R1-R4 are each optionally substd. aralkyl or alkyl or phenyl, or a residue forming a 5- - 8-membered ring together with N; Ar1-Ar4 are each optionally substd. arylene; X is O or S; and a benzene ring adjacent to a hetero ring may be substd.) and a charge generating layer. The obtained electrophotographic sensitive body is high in sensitivity, and has an advantage of small variation of the potentials in the light and in the dark during undergoing repeated cycles of charging and exposure.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to electrophotographic photoreceptors, and more particularly to electrophotographic photoreceptors having low molecular weight organic photoconductors that provide improved electrophotographic properties.

BACKGROUND ART Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been 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, or quickly dissipating the charge when irradiated with light. On the other hand, it has various drawbacks. For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, 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 do not provide stable sensitivity in humid environments, and zinc oxide photoreceptors require the full sensitizing effect of sensitizing dyes such as rose bengal. They have the disadvantage that they cannot provide stable images over a long period of time because the sensitive dyes undergo charging deterioration due to corona charging and photobleaching due to exposure light.

On the other hand, various organic photoconductive polymers, including polyvinylcarbazole, have been proposed, but these polymers are superior to the above-mentioned inorganic photoconductive materials in terms of film formability and light weight. Despite this, it has been difficult to put it into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic light sources lack sensitivity, durability, and stability against environmental changes. This is because it is inferior to the conductive diameter control. In addition, hydrazone compounds disclosed in U.S. Pat. No. 4S1509□87, triarylpyrazoline compounds disclosed in U.S. Pat. Low molecular weight organic photoconductors such as the 9-styrylanthracene compound described in et al. have been proposed. These low molecular weight organic photoconductors have been able to overcome the film-forming defects that had been a problem in the field of organic photoconductive polymers by appropriately selecting the binder used. It cannot be said that the sensitivity is sufficient.

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

However, electrophotographic photoreceptors using conventional low-molecular-weight organic photoconductors in the charge transport layer have not yet achieved sufficient sensitivity, and when repeatedly charged and exposed, The dark area potential has large fluctuations, and the photomemory property needs to be improved significantly.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an electrophotographic photoreceptor that eliminates the above-mentioned drawbacks or disadvantages of the present invention.

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

Another object of the present invention is to provide a novel charge transport material in a laminated photosensitive layer in which a charge generation layer and a charge transport layer are functionally separated.

Structure and Effects of the Invention The present invention is an electrophotographic photoreceptor characterized by having a layer containing a hydrazone compound represented by the following general formulas (1) and (2).

General formula (2) However, in the formula, R1, R2, R3 and R4 represent an alkyl group such as methyl, ethyl, propyl, butyl, an aralkyl group such as benzyl, phenethyl, naphthylmethyl, or a phenyl group, and the alkyl group is methoxy, The aralkyl group may be substituted with an alkoxy group such as ethoxy, propoxy, butoxy, a rogen atom such as fluorine, chlorine, bromine, iodine, or a dialkylamino group such as dimethylamino, diethylamino, dipropylamino, dibutylamino. basis,
The phenyl group is an alkyl group such as methyl, ethyl, propyl, butyl, an alkoxy group such as methoxy, ethoxy, propoxy, butoxy, a fluorine atom such as fluorine, chlorine, bromine, iodine, or dimethylamino, diethylamino, dipropylamino. , may be substituted with a dialkylamino group such as dibutylamino. In addition, R1, R2% R5 and R4H, together with NJp, represent the remainders forming a 5- to 6-membered group such as a pyrrolidyl group, a lysyl group, and a morpholino group.

Ar1, Ar2, Ar5 and Ar4 are the same or different and represent an arylene group such as phenylene, naphthylene, anthrylene, etc., and the arylene group is methyl, ethyl, propyl,
Alkyl groups such as butyl, alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, fluorine, chlorine, bromine,
It may be substituted with a -.rogen atom such as iodine.

X represents an oxygen atom or a sulfur atom.

In addition, in the formula, the benzyl groups adjacent to the heterocycle containing N include alkyl groups such as methyl, ethyl, propyl, and butyl, alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy, and halogens such as fluorine, chlorine, bromine, and iodine. It may be substituted with an atom or a dialkylamine group such as dimethylamino, diethylamino, dipropylamino or dibutylamino.

Compound example Next, an example of the formation of the above compound will be shown.

H-1 compound N-aminocarbazole 4B, 5fC0,266 mol)
was dissolved in 400 ml of methanol, and 4-
(4'-dimethylaminostyryl)benzaldehyde 66.9 t (0,266 mol) was added to 100 methanol
A solution dissolved in - was added dropwise to precipitate a large amount of yellow powdery precipitate. After several uses, it was reconsolidated from a mixed solvent of 160 tons of methanol and 240 tons of methyl ethyl ketone to obtain the desired H-1.
59.52 yellow crystals of the compound were obtained.

Yield 53.6% Elemental analysis results Molecular formula C29H25N5 Calculated value Analytical value CB5.85 8577 H6,866,14 N 10.11 10.09 In a preferred embodiment of the present invention, the photosensitive layer is a charge generation layer and a charge transport layer. A hydrazone compound represented by the above general formula (1) can be used as a charge transport material of a functionally separated electrophotographic photoreceptor.

The charge transport layer according to the present invention is preferably formed by applying a solution prepared by dissolving the hydrazone compound represented by the above-mentioned general formula (1) and a binder in an appropriate solvent and drying the solution. Examples of binders used in particular include polyarylate resins, polysulfone resins, polyamide resins, acrylic resins, acrylonitrile resins, methacrylic resins, vinyl chloride resins, vinyl acetate resins, phenolic resins, epoxy resins, polyester resins, and ayquito resins. , polycarbonate, polyurethane, or a copolymer resin containing two or more of the repeating units of these resins, such as styrene-butadiene copolymer, styrene-methacrylic copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, etc. I can do it. In addition to such insulating polymers, organic photoconductive polymers such as polyvinyl cal/2 sole, polyvinylanthracene, and polyvinylpyrene can also be used.

The blending ratio of the binder and the hydrazone compound is preferably 10 to 500 parts by weight of the total hydrazone compound per 100 parts by weight of the binder.

The charge transport R is electrically connected to the charge generation layer below, and has the function of receiving and taking charge carriers injected from the charge generation layer in the presence of an electric field, and transporting these charge carriers to the surface. have. 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 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
The binder varies depending on the type of binder used, and it is preferable to select one that does not dissolve the charge generation layer or underlying subbing layer. Specific organic solvents include ketones such as acetone, methyl ethyl ketone, and cyclohexanone, N,
Amides such as 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, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichloroethylene, benzene, toluene, xylene, ligroin,
Aromatic compounds such as monochlorobenzene and dichlorobenzene 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 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. Heat drying at a temperature of 60°C to 200°C for 5 minutes to 2
Can be performed stationary or under blown air for a period of time.

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

The charge generating layer used in the present invention includes selenium, selenium-tellurium, pyrylium, thiopyrylium dyes, phthalocyanine pigments, anthrone pigments, dibenzpyrenequinone pigments, pyran 5, thoron pigments, triazo pigments, disazo pigments, azo pigments, Indigo pigments, quinacridone pigments,
Asymmetric chimesyanin, quinocyanin or JP-A-1988
A separate vapor deposited layer or resin dispersion layer selected from a charge generating material such as amorphous silicon described in Japanese Patent No. 143,645 can be used.

Examples of the charge generating substance used in the electrophotographic photoreceptor of the present invention include the following inorganic compounds and organic compounds.

Charge generating substance (1) Amorphous silicon (2) Selenium-tellurium (3) Selenium-arsenic (4) Cadmium sulfide-methine squarate dye-) Indigo dye (C, 1, N078000) (60)
Thioindigo dye (C, ■, No. 78800) - β-type copper phthalocyanine (61) The charge generation layer can be formed by dispersing the charge generation substance described above in a suitable binder and coating this on the substrate. It can also be obtained by forming a vapor deposited film using a vacuum evaporation apparatus.Binders that can be used when forming the charge generation layer by coating can be selected from a wide variety of insulating resins, and poly-N- It can be selected from organic photoconductive polymers such as vinylcarbazole, polyvinylanthracene and polyvinylpyrene, preferably polyvinyl,
Butyral, polyarylate (condensation polymer of bisphenol A and heptalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin,
Examples include insulating resins such as polyacrylamide resin, polyamide, polyvinylpyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone. The amount of resin contained in the charge generation layer is 80% by weight or less, preferably 4% by weight.
0 weight - or less is suitable. Organic solvents used during coating include alcohols such as methanol, ethanol, and impropatul, acetone, methyl ethyl ketone,
Ketones such as cyclohexanone, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, methyl acetate, ethyl acetate, etc. esters, aliphatic halogenated hydrocarbons such as chloroform, cyclized methylene, dichloroethylene, carbon tetrachloride, trichloroethylene, or benzene,
Aromatics such as toluene, xylene, refloin, monochlorobenzene, dichlorobenzene, etc. can be used.

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

The charge generation layer contains as much of the organic photoconductor as possible in order to obtain sufficient absorbance and is preferably a thin film layer, for example less than 5 microns, in order to shorten the range of the generated charge carriers. is preferably a thin film layer having a thickness of 0.01 micron to 1 micron. This means that most of the incident light is absorbed by the charge generation layer, generating a large number of charge carriers, and that the generated charge carriers are injected into the charge transport layer without being deactivated by recombination or trapping (trapping). This is due to the need to do so.

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. Examples of substrates having a conductive layer include those in which the substrate itself is conductive;
For example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium,
Nickel, indium, gold, platinum, etc. can be used, and in addition, aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. can be formed into a film by vacuum evaporation method, and plastics having a layer (e.g. , polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluoroethylene, etc.), conductive particles (e.g.
A substrate in which carbon black, silver particles, etc.) is supported on a plastic together with a suitable binder, a substrate in which plastic or paper is impregnated with conductive particles, 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. The subbing layer is casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
Acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, ceratin,
It can be formed from aluminum oxide, etc.

The thickness of the undercoat layer is suitably 0.1 micron to 5 micron, preferably 0.5 micron to 3 micron.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, the hydrazone compound has hole transport properties, so the surface of the charge transport layer must be negatively charged, and when exposed to light after charging, In the exposed area, holes generated in the charge generation layer are injected into the charge transport layer, and then reach the surface to neutralize the negative charges, resulting in attenuation of the surface potential and an electrostatic contrast between the layer 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 specific example of the present invention, the above-mentioned disazo pigment or the pyrylium dye, thiapyrylium dye, selenapyrylium dye, Photoconductive pigments and dyes such as benzothiapyryllium dyes, naphthopyryllium dyes, and naphthothiapyrylium dyes can also be used as sensitizers.

In another specific example, a eutectic complex of a pyridium dye and an electrically insulating polymer having an alkylidene diarylene moiety as disclosed in US Pat. No. 3,684,502 and the like can be used as a sensitizer. This eutectic complex is, for example, 4-[4-bis-(2->loloethyl)aminofx
= #'] -2,6-cyphenylthiapyrylium perchlorate and poly(4,4'-impropylidene diphenylene carbonate) were mixed in a halogenated hydrocarbon solvent (e.g., dichloromethane, chloroform, carbon tetrachloride, 1. 1-dichloroethane, 1.2-'; dichloroethane i, 1.2-toIJ chloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene After dissolving in 9, add a non-polar solvent (e.g. hexane, It is obtained as a particulate eutectic complex by adding octane, decane, 2,2.4-)limethylbenzene, and ligroin. Contained as a binder in resins, vinylidene chloride-acrylonitrile copolymers, styrene-acrylonitrile copolymers, vinyl acetate-vinyl chloride copolymers, polyvinyl butyral, polymethyl methacrylate, BoIJ-N-butyl methacrylate, polyesters, cellulose esters, etc. I can do it.

The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser printers, 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 fluctuations in bright area potential and dark area potential are small when charging and exposure are repeatedly performed.

Hereinafter, the present invention will be explained according to examples. Example 1 β-type copper phthalocyanine manufactured by Toyo Ink Manufacturing ■ (trade name L
ionol Blue NCB Toner) f Pigment 72 purified by refluxing sequentially in water, ethanol and benzene and filtering; [Product name: Polyester Adhesive Q, 000 (solid content 2%) J14r manufactured by DuPont]
;) A coating solution was prepared by mixing 652 luene and 351 dioxane and dispersing in a ball mill for 6 hours.

This coating solution was applied to an aluminum sheet with a dry film thickness of 0.5
A charge generation layer was created by applying it with a Mayer purr to a micron thickness.

Next, as a charge transport compound, the exemplified compound H-11 was mixed with 81 and a polycarbonate resin (trade name: "
Panlite K-1300J 7F A solution obtained by stirring and dissolving in a mixed solvent of Tratetrahydrone Lan 352 and Chloropene Lan 357 was placed on top of the charge generation layer using a Mayer bar so that the dry film thickness was 11 microns. Coat it on,
An electrophotographic photoreceptor having a two-layer structure and one photosensitive layer was prepared.

The electrophotographic photoreceptor thus prepared was statically tested using Kawaguchi Electric's Seiden Copying Paper Testing Equipment Model SP-428k at -5KV in the corona zone W and L in the dark for 10 seconds.
After being held for a second, it was exposed to light at an illuminance of 5 lux to examine the charging characteristics.

As for the charging characteristics, the surface potential (To) and the exposure amount (]!!V2) required for the potential to decay to kW when dark decaying for 10 seconds (Vlo) were measured.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when repeatedly used, the photoreceptor prepared in this example was
, 6KV corona charger, lightning intensity 10 E, ux*ee
It was attached to the cylinder of an electrophotographic copying machine equipped with the exposure optical system of a, a developing device, a transfer charger, a static elimination exposure optical system, and a cleaner. This copying machine is configured to produce an image on transfer paper as a cylinder is driven. Using this copying machine, the initial bright area potential (VL) and dark area potential (
VD) and light area potential (VL) after 5000 uses
and dark potential (VD) were measured. The results are shown below.

Vo: -610 volts V1Q knee 570 volts A: 3.71ux, sec Initial VTI-61 after 5000 endurance
5 Port VTl-34 Volt VD-610 Volt VL-
40 Volt Examples 2 to 10 In each of these Examples, Exemplified Compound H was used in place of Exemplified Compound H-1 as the charge transport compound used in Example 1.
-2, H-3, H-6, H-7, H-9, H-10, H
Example 1 except that -11, H-12, and H-14 were used.
An electrophotographic photoreceptor was prepared in the same manner as described above.

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

2 H-22, 75805753H-32,
6585575 4H-63,5570560 5H-72,4570565 6H-9,-5,9560555 7H-103゜1575570 8 H-113゜0 565 5
559 H-122, 75905851D
H-143, 2575570 early
Example after 5000 times durability VD (Published by Iruto)
VL (-volt) VD (-volt) V L (set)
2 625 25 625 3
53 625 25 620
304 10 35
605 455 610 2
5 600 456 600
40 590 507
615 30 600 40
8 605 30 600
35 Initial Example after 5000 cycles of durability VD (-Volt) vL (-d7 Ruto) vD (-i Ureto) VL (-Anai Ruto) 9 630
50 615 4010 620
30 610 45 Example 11 4-(4-dimethylaminophenyl)-2,6-cyphenylthiahylylium-chlorate 3f and the above-mentioned hydrazo/compound H-45f'e polyester (Polyester Adhesive 49000: DuPont The mixture was mixed with 100 d of a toluene (50)-dioxane (50) solution (manufactured by Co., Ltd.) and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet using a Mayer Parr so that the film thickness after drying was 15 microns.

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

v(,: -555 volts Vjo: -550 volts E%: 2.61ux+sec Initial VD knee 595 volts VL: -'25 volts VD knee 590 volts after 5000 cycles ML: -?) 5 volt example 12 Aluminum plate Aqueous ammonia solution of casein (casein 1
1.2F, 28% ammonia water, 14F, water 222
7 was applied and dried using Mayer Parr to form an adhesive layer with a film thickness of 1 micron.Next, disazo pigment 52 having the following structure and butyral resin (butyralization degree 63 mol%) 22 were mixed with ethanol 9
After being dispersed with a liquid dissolved in 5-, the charge generating layer was coated on the adhesive layer to form a charge generating layer having a thickness of 0.4 microns after drying.

Next, the above-mentioned hydrazone compound H-55f and poly-
A solution prepared by dissolving 4,4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 300'00) 52 in dichloromethane 150 was dried in the shade on the charge generation layer to obtain a film thickness of 11 microns. Next, create an electrophotographic photoreceptor by forming a charge transport layer.

The electrophotographic properties of the electrophotographic photoreceptor produced in this manner were measured in the same manner as in Example 1.

The results are shown below.

vQ: -630 volts Vlo: 630 volts El, S: 3.1], ux-sec initial VD: 670 volts VL: -35 volts VD after 5,000 cycles of endurance: -660 volts VL: -45 volts Example 16 Surface A cleaned molybdenum plate (substrate) with a thickness of 0.2 van was fixed at a predetermined position in a glow discharge deposition tank.

Next, the tank was completely evacuated to a vacuum level of about 5 x 10-6 t, orr. Thereafter, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150°C. After that, hydrogen gas and silane gas (15% by volume relative to hydrogen gas) were introduced into the tank, and the gas flow rate and main valve of the evaporation tank were adjusted to 0.5%.
It was stabilized at torr. Next, 5 MHz high frequency power was applied to the induction coil to generate glow discharge inside the coil in the tank, resulting in an input power of 50 W. An amorphous silicon film was grown on the substrate under the above conditions, and the same conditions were maintained until the film thickness reached 2 microns, after which glow discharge was discontinued. After that, turn off the heating heater and high frequency power supply, wait for the substrate temperature to reach 100℃, close the hydrogen gas and silane gas outflow valves, and once the temperature inside the tank is below 10-5 torr, return to atmospheric pressure and remove the substrate. I took it out. Next, a charge transport layer was formed on this amorphous silicon layer in exactly the same manner as in Example 1 except that Exemplified Compound H-81 was used as the charge transport compound.

The photoreceptor obtained in this way was installed in a charging exposure experiment equipment and
It was corona charged at 6 KV and immediately irradiated with a light image. The light image was illuminated through a transmissive test yard using a tungsten lamp light source. Immediately thereafter, a good toner image was obtained on the surface of the photoreceptor by cascading a charged developer (containing toner and carrier) onto the surface of the photoreceptor.

Example 14 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate 3f t, t?
After thoroughly dissolving IJ (4,4'-isopropylidene diphenylene carbonate) 3f in 200 m of dichloromethane, it was added to 100 m' of toluene to precipitate the eutectic complex. After filtering this precipitate, dichloromethane was added to dissolve it again, and then 100 tons of n-hexane was added to this solution.
In addition to t', a precipitate of the eutectic complex was obtained.

This eutectic complex 5? was added to 95ml of a methanol solution containing polyvinyl butyral 22, and dispersed in a ball mill for 6 hours. This dispersion was coated onto an aluminum plate having a casein layer using a Mayer par so that the film thickness after drying was 0.4 microns to form a charge generation layer.

Next, a coating layer similar to the charge transport layer used in Example 1 was formed on this charge generation layer, except that Exemplary Compound H-13 was used.

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

v(, Knee 635 volts V, Q Knee 630 volts B%: 1.91 uxjsec Initial VD: -675 volts vL: -20 volts VD after 5000 times endurance: -665 volts VL: -35 volts Example 15 In Example 14 A compound similar to the eutectic complex 57 used and the above-mentioned hydrazone compound H-1559 were added to 15 Grne of a tetrahydro 7 run solution of polyester resin (Polyester Adhesive 49000, manufactured by DuPont), and thoroughly mixed and stirred. The liquid was applied onto an aluminum sheet using a Mayer Parr so that the film thickness after drying would be 15 microns.

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

vo: -585 volts vla: -580 volts El/, : 1.81ux-sec initial Vl) knee 645 volts VL: -20 volts After 5000 times durability ■D knee 625 volts Vr: -30 volts

Claims (1)

[Claims] (1) An electrophotographic photoreceptor characterized by having a layer containing a hydrazone compound represented by the following general formulas (1) and (2). However, in the formula, R1, R2, R5 and B4 are an alkyl group, an aralkyl group, a phenyl group, or an N
Shows the remaining atoms that form 5- to 6-membered terms with atoms. Ar1, Ar2, Ar5 and Ar4 represent arylene groups which may have the same or different substituents. X represents an oxygen atom or a sulfur atom. Further, the benzene ring adjacent to the heterocycle may have a substituent.