JPS62250459A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having sufficient sensitivity and characteristics, and less tendency for changing the voltages in a light part and a dark part, even if in case of charging and exposing repeatedly by mounting a layer contg. a specific compd. on the titled body. CONSTITUTION:The titled body comprises the layer contg. a compd. shown by the formula. The compd. shown by the formula is used as the electrostatic charge transfer substance of the titled body in which, for example, the photosensitive layer is separated functionally an electrostatic charge generating layer and an electrostatic charge transfer layer. The layer contg. the compd. is formed by coating a solution dissolved the compd. and a binding agent in a suitable solvent on a substrate, followed by drying it. The used binding agent is exemplified by for example, a polyalkylate resin or polysulfone resin, etc. The compounding ratio of the binding agent and the compd. shown by the formula is preferably 10-500pts.wt. the compd. per 100pts.wt. the binding agent, thereby obtaining the titled body having a high sensitivity. The variance of the potential in the light and dark parts is lessened, even if in case of charging and exposing repeatedly.

Description

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

[Prior art]

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 being able to rapidly dissipate charge when irradiated with light. , has various drawbacks. For example, in selenium-based photoreceptors, crystallization easily progresses due to factors such as temperature, humidity, dust, and pressure. Especially when the ambient temperature exceeds 40°C, crystallization becomes significant, resulting in decreased charging performance and white spots on images. There are drawbacks such as the occurrence of Cadmium sulfide photoreceptors do not provide stable sensitivity in humid environments, and zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal. The sensitizing dye suffers from charging deterioration due to corona charging and photobleaching due to exposure light, so it has the disadvantage that it cannot provide stable images over a long period of time.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior in terms of film formability and lightness compared to the inorganic photoconductive materials mentioned above. However, it has been difficult to put them into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic photoconductive materials lack sensitivity, durability, and stability against environmental changes. This was because it was inferior to the

In addition, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, triarylpyrazoline compounds described in U.S. Pat.
Low-molecular organic photoconductors such as 9-styrylanthracene 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 had been a problem in the field of organic photoconductive polymers. 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 strength, 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, electrophotographic photoreceptors using conventional low-molecular organic photoconductors in the charge transport layer do not always have sufficient sensitivity and characteristics, and when repeatedly charged and exposed, bright areas There are large fluctuations in potential and dark potential (there are points 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 eliminates the above-mentioned drawbacks or disadvantages.

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.

[Means for solving problems]

This object of the present invention is achieved by an electrophotographic photoreceptor having a layer containing a compound represented by the following general formula.

In the general formula, R3 represents an alkyl group such as methyl, ethyl, propyl or butyl, or an aralkyl group such as benzyl, phenethyl or naphthylmethyl. These alkyl groups and aralkyl groups include halogen atoms such as fluorine, chlorine, bromine, and iodine, alkyl groups such as methyl, ethyl, propyl, and butyl, alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, and aralkyl groups such as benzyl and phenethyl. , phenyl,
It may be substituted with an aryl group such as naphthyl or fluorenyl, a substituted amino group such as diethylamino, dibutylamino, or diphenylamino, a nitro group, or a cyano group.

R2+R3+R4+R5 is methyl, ethyl, propyl,
Alkyl groups such as butyl, aralkyl groups such as benzyl, phenethyl, naphthylmethyl, aryl groups such as phenyl, naphthyl, fluorenyl, or pyridyl, quinolyl, furyl, chenyl, pyryl, oxasilyl, thiazolyl,
It represents a heterocyclic group such as imidazolyl, triazolyl, oxadiazolyl, thiadiazolyl, indolyl, carbazolyl, benzoxasilyl, benzothiazolyl, benzimidazolyl, and benzotriazolyl. These alkyl groups, aralkyl groups, aryl groups, and heterocyclic groups include halogen atoms such as fluorine, chlorine, bromine, and iodine, alkyl groups such as methyl, ethyl, propyl, butyl, methoxy, ethoxy,
Alkoxy groups such as propoxy and butoxy, aralkyl groups such as benzyl and phenethyl, aryl groups such as phenyl, naphthyl and fluorenyl, substituted amino groups such as diethylamino, dibutylamino and diphenylamino, nitro groups,
Alternatively, the ring may be substituted with a cyano group.

Also R2. R3 or R4, R5 together with the nitrogen atom is piperisheet, piperazino, morpholino, carbazolyl, etc. 5-
Residues forming a 6-membered ring are shown.

X, X2 is a hydrogen atom, a halogen atom such as fluorine, chlorine, bromine, iodine, an alkyl group such as methyl, ethyl, propyl, butyl, an alkoxy group such as methoxy, ethoxy, propoxy, butquine, a nitro group, a cyano group, Or it represents a trifluoromethyl group.

The following is a list of representative examples of compounds shown by the general formula.

Compound example (20) (i: C21) C2H5
Next, a synthesis example of the above compound will be shown.

Synthesis Example (Example No. Synthesis of Compound (1)) 10.24 g of N-methyl-4,4'-diaminodiphenylamine
(0,048 mol) in 200ml of anhydrous tetrahydrofuran
! ! 5.80 g (0,145 mol) of oily sodium hydride (containing FF 160%) was dissolved in the liquid and stirred while cooling with water.
Add slowly. Once foaming has stopped, return to room temperature 3
Stir for 0 minutes. Next, 11.6 ml of ethyl iodide (0,
145 mol) was added dropwise and stirred at room temperature for 30 minutes after the dropwise addition. After that, the reaction mixture was further stirred under reflux for 8 hours. After the reaction was completed, the reaction product was poured into water If, and 300 mol of ethyl acetate was added.
Extract twice with mIt, and the ethyl acetate layer is washed with water and dried over sodium sulfate. The solvent was distilled off under reduced pressure, and the residual liquid was recrystallized from cyclohexane to which a small amount of ethyl acetate was added. Og crystals were obtained. Yield 76.7% Elemental analysis value Calculated value Measured value C77,4977,31 H9,609,53 N 12.91 12.94 For compounds other than the above synthesis examples, the required diamino form is generally combined with potassium hydride. It is synthesized using a similar synthetic method using alkyl iodides, aralkyl halides, aryl halides, etc. However, R2, R3, R4,
When R5 (same as shown in the claims) is different, for example, one of the required dinitro forms is partially reduced, the above substitution reaction is carried out, and the remaining nitro group is further reduced, Procedures such as carrying out a reaction are required.

In a preferred embodiment of the present invention, a compound represented by the above general formula can be used as a charge transport 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 according to the present invention is preferably formed by applying a solution prepared by dissolving the compound represented by the above general formula and a binder in an appropriate solvent and drying the solution. Examples of the binder used here include polyarylate resin, polysulfone resin, polyamide resin, acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, and polycarbonate. , polyurethane, or copolymer resins containing two or more repeating units of these resins, such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, and the like. In addition to such insulating polymers,
Organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene and polyvinylpyrene can also be used.

The blending ratio of the binder and the compound is preferably 10 to 500 weight of the compound per 1 part of 100 weight of the binder.

The charge transport layer is electrically connected to the charge generation layer described above, 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 desirable 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 the above-mentioned subbing layer. Specific organic solvents include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and dimethylsulfoxide. sulfoxides such as tetrahydrofuran, dioxane, ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene. or aromatic compounds such as benzene, toluene, xylene, ligroin, monochlorobenzene, and cyclolbenzene.

Coating methods include dip coating method, spray coach ink 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. Heat drying at a temperature of 308C to 200C for 5 minutes.
It can be carried out stationary or under blown air for a time in the range of 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, dilaurylthiopropionate. , 3,5-dinitrosalicylic acid, and various fluorocarbons.

The charge generation layer used in the present invention includes selenium, selenium-tellurium, pyrylium, thiopyrylium, azulenium dyes,
Phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, thiacyanine, asymmetric quinocyanine, quinocyanine or as described in JP-A-54-143645 Separate deposited layers or resin dispersion layers of charge generating materials such as amorphous silicon 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 (19)-2 Methine squaric acid dye (I9)-3
Indigo dye (C, 1, No. 78000) (
1G)-4thioindigo dye (C, 1, No, 788
00)(19)-5β-type copper lid cyanine charge generating layer can be formed by dispersing the charge generating substance described above in a suitable binding agent and coating it on the substrate, or by vacuum evaporation. It can be obtained by forming a vapor-deposited film using an apparatus. Binders that can be used to form the charge generating layer by coating can be selected from a wide variety of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene. . Preferably, polyvinyl alcohol, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyridine, cellulose resin, Urethane resin, epoxy resin,
Examples include insulating resins such as casein, polyvinyl alcohol, and polyvinylpyrrolidone. The resin contained in the charge generation layer is 80% by weight or less, preferably 40% by weight or less.
Heavy ■% or less is suitable. 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, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, chloroform, methylene chloride,
Aliphatic halogenated hydrocarbons such as dichloroethylene, carbon tetrachloride, trichlorethylene, benzene, toluene, xylene, ligroin, monochlorobenzene,
Aromatics such as 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 bar 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 as possible in order to obtain sufficient absorbance, and the range of the generated charge carriers is short (in order to make the range of the generated charge carriers short, for example, a thin film layer, e.g. less than 5 microns, It is preferable to use a thin film layer with a thickness of 0.01 micron to 1 micron.This means that most of the incident light is absorbed by the charge generation layer, producing a large number of charge carriers. Furthermore, the generated charge carriers are not deactivated by recombination or trapping (this is due to the need to inject them into the charge transport layer).

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, plastics having a layer formed by vacuum evaporation of aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluorinated ethylene, etc.), conductive particles (e.g., aluminum powder, titanium oxide, tin oxide, zinc oxide, carbon black, silver particles, etc.) with a suitable binder. Plastic or a substrate coated on the conductive substrate, a substrate made of plastic or paper impregnated with conductive particles, a plastic containing a conductive polymer, etc. can be used.

An undercoat layer having barrier and adhesive functions can also be provided between the conductive layer and the photosensitive layer. The undercoat layer is 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. can.

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

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, since the compound has hole transport properties, 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 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 example, a eutectic complex of a pyrylium dye and an electrically insulating polymer having an alkylidene diarylene moiety, as disclosed in US Pat. No. 3,684,502, can also be used as a sensitizer. This eutectic complex is, for example, 4
-[4-bis-(2-chloroethyl)aminophenyl)
-2,6-Cyphenylthiapyrylium perchlorate and poly(4,4-isopropylidene diphenylene carbonate) are mixed in a halogenated hydrocarbon solvent (e.g., dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, bromobenzene, 1
12-dichlorobenzene) and then dissolved in a non-polar solvent (e.g. hexane, octane, decane, 2.2-dichlorobenzene).
A particulate eutectic complex is obtained by adding 4-trimethylbenzene and ligroin. 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 and the like 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 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 Co., Ltd. (trade name: Lionol Blue NCB Toner)
) in water, ethanol and benzene, and then filtered to purify the pigment. 7 g; Product name: Polyester Adhesive 49,000 (solid content 20%) manufactured by DuPont
A coating solution was prepared by mixing 35 g of toluene and 35 g of dioxane and dispersing the mixture in a ball mill for 6 hours. This coating solution was spread on an aluminum sheet using a Mayer bar so that the dry film thickness was 0.5 microns to form a charge generation layer.

Next, the exemplified compound (5) was used as a charge transport compound.
A solution obtained by stirring and dissolving 7 g of polycarbonate resin (trade name: ``Panlite Ni-ichi 11300J'' manufactured by Kijin Kasei Co., Ltd.) in a mixed solvent of 35 g of tetrahydrofuran and 35 g of chlorobenzene was placed on the charge generation layer. , coated with a Mayer bar to a dry film thickness of 11 microns,
An electrophotographic photoreceptor with a photoreceptor having a two-layer structure was created.

The electrophotographic photoreceptor produced in this way was manufactured by Kawaguchi Electric Co., Ltd.
Electrostatic copying paper tester Model-3P-428 was used to statically charge the corona at 15 KV, and the test was carried out in the dark at 1
After being held for a second, it was exposed to light at an illuminance of 51 ux and the charging characteristics were examined.

The charging characteristics include the surface potential (VO) and the exposure amount required to attenuate the potential (vl) when dark decaying for 1 second (
E! /6) was measured.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential during repeated use, the photoreceptor prepared in this example was attached to the photosensitive drum cylinder of a PPC copier NP-150Z manufactured by Canon Inc. , 50,000 copies were made with the same machine, and the bright area potential (VL
) and dark potential (Vo) were measured.Comparative sample-1 was prepared in exactly the same manner using a compound having the following structural formula in place of the above-mentioned exemplified compound, and measured in the same manner.

The results are shown below.

Table 1 In each of Examples 2 to 1, Exemplified Compound (1) was used instead of Exemplified Compound (5) as the charge transport compound used in Example 1.
), (3), (4), (6), (7), (9), (11
).

(12), (13), (18), (21), (22),
(23), (30).

(31) and exemplified as a charge generating substance (16)
An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the following pigment was used.

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

E'A VDV H Example Illustrated compound (Iux-sec)
(-volt) (-volt) 2 1
2.0 605 5953
3 2.3 620
6054 4 3.5
590 5805 6
2.0 590 575
6 7 1.3 60
5 6007 9 2
．． 6 580 5608
11 2.1 600 5
809 12 3.0
600 58510 13
1.5 610 60011
18 2.7 595
59012 21 2.9
585 58013 2
2 1.4 605 59
014 23 2.8
620 60015 30
2.4 625 61516
31 1.7 590
575 early 50
Example after 000 sheets durability VD (-volt) VL (-volt) B
700 100 675
135 Example 17 Aqueous ammonia solution of casein (11.2 g of casein, 1 g of 28% aqueous ammonia,
Water 22.2m! Coating by dip coating method, drying and coating fi1. og/n? A subbing layer was formed.

Next, 1 part by weight of the charge generating substance of Example No. 25, 1 part by weight of butyral resin (Eslec BM-2, manufactured by W1 Suikagaku Co., Ltd.) and 30 parts by weight of isopropyl alcohol were dispersed for 4 hours using a ball mill disperser. This dispersion was applied onto the previously formed subbing layer by a dip coating method and dried to form a charge generating layer. The film thickness at this time was 0.3 microns.

Next, 1 part by weight of the above-exemplified compound No. (2) of the present invention, 1 part by weight of polysulfone resin (P1700, manufactured by Union Carbide), and 6 parts by weight of monochlorobenzene were mixed and dissolved by stirring with a stirrer. . This liquid was applied onto the charge generation layer by dip coating and dried to form a charge transport layer. The film thickness at this time was 12 microns.

Corona discharge of -5 KV was applied to the photoreceptor thus prepared. The surface potential at this time was measured (initial potential VO)
. Furthermore, the surface potential of this photoreceptor was measured after it was left in a dark place for 5 seconds (attenuation). Sensitivity was evaluated by measuring the exposure amount (E% microjoule/ctd) required to attenuate the potential VK after dark decay to 1/2. At this time, the light source was a gallium/aluminum/propylene ternary semiconductor laser (output: 5 mW, oscillation wavelength: 7
80 nm) was used.

These results were as follows.

Vo: -680 volt potential retention rate = 94% (÷X100) Ey: 1.0 microjoules/crd Next, a laser beam printer (Canon (LnP-CX) manufactured by LBP-C
An actual image forming test was conducted by replacing the photoreceptor with the photoreceptor of X. The conditions are as follows.

-Surface potential after secondary charging: -700V, surface potential after image exposure: -150V (Exposure m 1.2 tt J/c
rrr), transfer potential; +700V, developer polarity: negative polarity, process speed; 50 mm/sec, development conditions (
Development bias); -450V, image exposure scanning method; image scanning, - exposure before next charging; 501 ux-s
The full red exposure of ec and image formation were carried out by line scanning a laser beam in accordance with character signals and image signals, and good prints were obtained for each character image.

Example 18 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and 5 g of the above-mentioned exemplary compound (No. (8)) were mixed into polyester (Polyester Adhesive 49000: manufactured by DuPont) of toluene (
50)-Dioxane (50) solution 100mj! and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet using a Mayer bar so that the film thickness after drying was 15 microns.

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

Vo knee 620 volts v, knee 610 volts E%: 1.61! ux, sec treated once Vo knee 695 volts Vt: -70 volts 50000 /'
1.2g, 28% ammonia water 1g, water 222ml)
was coated with a Mayer bar 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 2 g of butyral resin (degree of butyralization: 63 mol%) were mixed with 9 mol of ethanol.
After being dispersed with a solution dissolved in a volume of 5 ml, the charge generating layer was coated on the adhesive layer to form a charge generation layer having a thickness of 0.4 microns after drying.

Next, a solution of 5 g of the above-mentioned exemplified compound (No. (14)) and 5 g of poly-4,4'-dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 3oooo) dissolved in 150 mA' of dichloromethane was added. An electrophotographic photoreceptor was prepared by coating and drying on the charge generation layer to form a charge transport layer having a thickness of 11 microns.

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 knee 605 volts V, knee 595 volts E'/2: 2.31 ux, sec 匪-亙Vl) knee 705 volts Vl, knee 70 volts 50000 1' Vo knee 670 volts VL knee 100 volts Example 20 Surface is clean A molybdenum plate (substrate) with a thickness of 0.2 mm was fixed at a predetermined position in a glow discharge deposition tank.

Next, the inside of the tank was evacuated to a vacuum level of about 5XlO-6 torr. 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 deposition tank were adjusted to 0.5 torr.
stabilized at r. 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 30 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 μm, 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°C, close the hydrogen gas and silane gas outflow valves, and once reduce the inside of the tank to 10-' t o r r or less, and then reduce the atmospheric pressure. I put it back and took out the board. Next, a charge transport layer was formed on this amorphous silicon layer in exactly the same manner as in Example 1 except that Exemplary Compounds No. 1 and 1 were used as charge transport compounds.

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 transmission type test chart 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 21 3 g of 4-(4-dimethylaminophenyl)-2,6-siphenylthiapyrylium perchlorate and poly(4,4
--Isopropylidene diphenylene carbonate) 3g
200mj of dichloromethane! After sufficiently dissolving, add 100 mj of toluene! was added to precipitate the eutectic complex. After filtering this precipitate, dichloromethane was added to redissolve it, and then 100 ml 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 methanol solution containing 2 g of polyvinyl butyral and dispersed in a ball mill 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 microns.

Next, exemplified compound No. is applied on this charge generation layer.

A cover layer of a charge transport layer was formed in the same manner as in Example 1 except that (25) was used.

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

Vo knee 600 volts V, knee 590 volts EH two 1.9 1! ux, sec expansion Vo knee 695 volts VT knee 75 volts 5000 and length Vo knee 660 volts VL knee 105 volts Example 22 5 g of the same eutectic complex used in Example 21 and the above-mentioned compound ( No, (28)) 5g of polyester (
Polyester Adhesive 49000: DuPont) tetrahydrofuran solution 150mI! In addition, the mixture was thoroughly mixed and stirred. This liquid was spread on 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 knee 590 volts +: 580 volts Ez: 2.41 ux, sec Vonie 700 volts VL knee 60 volts 50,000 But no'' Vonie 660 volts Vt, 'knee 95 volts [Effects of the invention] Like this The electrophotographic photoreceptor according to the present invention has high sensitivity and excellent potential stability, especially in continuous image formation in which charging and exposure are repeated.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor characterized by having a layer containing a compound represented by the following general formula. General formula▲There are numerical formulas, chemical formulas, tables, etc.▼ However, in the formula, R_1 represents an alkyl group or an aralkyl group that may have a substituent. R_2, R_3, R_4, R_
5 is an alkyl group, an aralkyl group that may have a substituent,
Indicates an aryl group or a heterocyclic group. Also, R_2, R_
3, R_4, and R_5 represent a residue that forms a 5- to 6-membered ring together with the nitrogen atom. X_1 and X_2 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, a nitro group, a cyano group, or a trifluoromethyl group.