JPS6313048A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body having high performance by using a hydrazone compd. contg. an org. group derived from a prescribed dicarbazole, alkyl group, aralkyl group, aryl group or heterocyclic group, etc. CONSTITUTION:The hydrazone compd. expressed by the general formula is dissolved together with an acrylic resin, etc., in a solvent and the soln. is coated on an electric charge generating layer and dried. Such photosensitive body exhibits a good electrophotographic characteristic as the pi electron conjugated system is remarkably activated. In the formula, the group A is the di- or trivalent org. group derived from 3, 3'-dicarbazole, 1,3'-dicarbazole or 9,9'-dicarbazole and may have a substituent such as alkyl group or halogen atom. R1 is H, alkyl group, aralkyl which is unsbstd. or has a prescribed substituent, aryl group or heterocyclic group. R2, R3 are of the same content as the content of R1 except H and are the residual groups such as piperazine 1 to form 5--6- membered rings by combining with N at the center. n Is 2 or 3.

Description

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

[Prior Art] Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are conventionally 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 being able to rapidly dissipate charge when irradiated with light. 0 For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, and pressure. Especially when the ambient temperature exceeds 40°C, crystallization becomes significant and the electrostatic charge increases. There are disadvantages such as reduced quality and spots in the image. 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.
Such sensitizing dyes suffer from charge deterioration due to corona charging and discoloration due to exposure light, and therefore have the disadvantage that they cannot provide reliable 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 to the aforementioned inorganic photoconductive materials in terms of film formability and light weight. However, it has been difficult to put it into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic photoconductors have been lacking in sensitivity, durability, and stability against environmental changes. This was because the material was inferior. Also, hydrazone compounds disclosed in US Pat. No. 4,150,987, triarylpyrazoline compounds described in US Pat. No. 3,837,851, JP-A-51-94828, JP-A-51-94829, etc. Low-molecular organic photoconductors have been proposed, such as the 9-styrylanthracene compound described in . 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 is not sufficiently sensitive.

For this reason, in recent years, a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed. 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 an electrophotographic photoreceptor is disclosed in, for example, US Pat. No. 383
It is disclosed in US Pat. No. 7,851, US Pat. No. 3,871,882, and the like.

However, the sensitivity and characteristics of conventional electrophotographic photoreceptors using low-molecular organic photoconductors in the charge transport layer are not necessarily sufficient, especially when repeated charging and exposure are performed. There are large fluctuations and there are areas that need improvement.

[Problems to be Solved by the Invention] An object of the present invention is to provide an electrophotographic photoreceptor that eliminates the above-mentioned drawbacks or disadvantages, to provide a novel organic photoconductor, and further to provide a charge generating layer and a charge generating layer. An object of the present invention is to provide a novel charge transport material in a laminated photosensitive layer which is functionally separated from the charge transport layer.

[Means for Solving the Problems, Effects] The present invention comprises an electrophotographic photoreceptor characterized by having a layer containing a hydrazone compound represented by the following general formula.

In the formula, A represents a divalent or trivalent organic group derived from 3,3°-dicarbazole, 1.3°-dicarbazole or 9.9°-dicarbazole, which may have a substituent. , Examples of groups optionally substituted on the dicarbazole include methyl, ethyl, propyl, butyl, hexyl,
Alkyl groups such as octyl; flukoxy groups such as methoxy, ethoxy, propoxy, and butoxy; halogen atoms such as fluorine, chlorine, bromine, and iodine; substituted amine groups such as dimethylamino, diethylamino, diphenylamino, and cyanidylamino; Substituted or methyl, alkyl groups such as ethyl, propyl, butyl, flukoxy groups such as methoxy, nidoxy, propoxy, butoxy, halogen atoms such as fluorine, chlorine, bromine, iodine, or dimethylamino, diethylamino, diphenylamino Heptaralkyl groups such as benzyl, phenethyl, and methylnaphthyl substituted with substituted amino groups such as, unsubstituted or alkyl groups such as methyl, ethyl, propyl, and butyl, flukoxy groups such as methoxy, ethoxy, propoxy, and butoxy, and fluorine atoms , halogen atoms such as chlorine, bromine, and iodine atoms, substituted amine groups such as dimethylamino, diethylamino, and diphenylamino, and aryl groups such as phenyl, naphthyl, anthranyl, and fluorenyl substituted with nitro and trifluoromethyl groups. can be mentioned.

R1 is a hydrogen atom, an alkyl group such as methyl, ethyl, propyl, butyl, hexyl, octyl, unsubstituted or an alkyl group such as methyl, ethyl, propyl, butyl,
Benzyl and phenethyl substituted with alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy, halogen atoms such as 5+1 fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, and substituted amine groups such as dimethylamino, diethylamino, diphenylamino, and cyanidylamino. , aralkyl group such as methylnaphthyl, phenyl or naphthyl unsubstituted or substituted with the same substituent as the aralkyl group,
7-aryl groups such as biphenyl, anthryl, and fluorenyl, or furyl, chenyl, carbazolyl, and oxasilyl, which are unsubstituted or substituted with the same substituent as the aralkyl group.

Indicates a heterocyclic group such as oxadiazolyl, thiazolyl, imidazolyl, triazolyl or phenyl group, or a derivative thereof having a fused benzene ring.

R2 and R3 have the same contents as R1 except for the hydrogen atom.

Furthermore, R2 and R3 represent residues that combine with the central nitrogen atom to form a 5- to 6-membered ring such as piperazino, morpholino, and carbazolyl.

n is an integer of 2 or 3.

The charge transport substance represented by the above general formula in the present invention is:
Because it uses a series of molecularly large carbazole rings and has two to three hydrazone structures, it is thought that the π-electron conjugated system becomes extremely active and produces the desired effect. .

Representative examples of the hydrazone compound represented by the above general formula in the present invention are listed below.

(lO) u2Hg U2)+y I;zHg GzH3u
Lil13 UUI'13shi83
CHx Next, a synthesis example of the above compound will be shown.

Synthesis of Illustrative Compound Example (1) 32.14 g of N,N-ethylphenylhydrazine (0,
236 mol) was placed in a standing flask, and 350 mol of glacial acetic acid was added.
59.06 g (o, tia mol) of 6,6'-diformyl-9,9°-dibutyl-3,3'-licarbazole, dissolved in a mixture of 350 ml of methanol and 200 ml of glacial acetic acid, ) was added dropwise with stirring at room temperature. After 0 dropwise addition, the product was left stirring for 1 hour, the product was filtered off, thoroughly washed with methanol, and then recrystallized from methyl ethyl ketone. After rough filtration, the product was recrystallized from methanol-containing methyl ethyl ketone to obtain 54.79 g of the desired product. The yield was 63%.

Elemental analysis value Calculated value Actual value C81,4981,58 H7,117,05 N 11.40 11.37 The hydrazone compounds other than this example are also generally diformyl- or triformylated silazine (R2 and R3 are the (synonymous with R2 and R3 in the general formula) under the same conditions as in the synthesis example.

In a preferred embodiment of the present invention, a hydrazone compound represented by the above general formula can be used as the charge transport material of 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 and drying a solution in which a hydrazone compound represented by the above general formula and a binder are dissolved in an appropriate solvent.

Examples of the binder include polyarylate, polysulfone, polyamide, acrylic resin, acrylonitrile resin,
Methacrylic resin, polyvinyl chloride, polyvinyl acetate, phenolic resin, epoxy resin, polyester, alkyd resin, polycarbonate, polyurethane, or a copolymer containing two or more repeating units of these resins, such as styrene-butadiene copolymer, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, and the like. In addition to such insulating resins, organic photoconductive polymers such as polyvinylcarbazole, 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 per 100 parts by weight of the binder.

The charge transport layer is electrically connected to the underlying charge generation layer, 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, the charge transport layer may be laminated on top of the charge generation layer or may be laminated below. However, the charge transport layer may be layered on the charge generation layer. preferable.

The charge transport layer has a limit in its ability to transport charge carriers, so it cannot be made thicker than necessary.The thickness of the charge transport layer is generally 5 to 30 g, but the preferred range is 8 to 20 g.

The solvent used to form the charge transport layer varies depending on the type of binder used, and is preferably selected from those that do not dissolve the charge generation layer or underlying undercoat layer.

For example, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexane, and 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, chloroform, and methylene chloride. , aliphatic halogenated hydrocarbons such as dichloroethylene, carbon tetrachloride, and trichlorethylene, or aromatic hydrocarbons such as benzene, toluene, xylene, ligroin, monochlorobenzene, and dichlorobenzene.

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.

Drying is preferably carried out by drying to the touch at room temperature and then heating. Drying by heating can be carried out at 30° to 20° C. for 5 minutes to 2 hours either stationary or under blowing air.

The charge transport layer 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, dilaurylthiopropyl ester, 3,5-dinitrosalicylic acid, various fluorocarbons, and the like.

The charge generating layer in the present invention includes selenium, selenium-tellurium, pyrylium dye, thiapyrylium dye, azulenium dye, phthalocyanine pigment, anthanthrone pigment, dibenzpyrenequinone pigment, pyranthrone pigment, trisazo pigment, disazo pigment, monoazo pigment, and indigo pigment. ,
Quinacridone pigment, thiacyanin, asymmetric quinocyanin, quinocyanin, etc. or JP-A-143645-1985
It can be formed as a vapor deposited layer or a resin dispersed layer using a charge generating substance such as amorphous silicon described in the above publication.

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 (lO) (3B) (3θ)
Shiyu Hi (5B) (58) Squaric acid methine dye (59)
Indigo dye (60) Thioindigo dye (61) β-type copper phthalocyanine (B4) (8B) (B7) M-111111-J The charge generation layer combines the above charge generation substance with a suitable binder. It can be formed by dispersing it in water and coating it on a substrate, or it can also be obtained by forming a vapor deposited film using a vacuum evaporation device.

The binder that can be used when forming the charge generation layer by coating can be selected from a wide range of insulating resins, and
It can be selected from organic photoconductive polymers such as N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene.

Preferably, polyvinyl butyral, polyarylate (
Insulating materials such as polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, polyurethane, casein, polyvinyl alcohol, polyvinylpyrrolidone, etc. For example, polyester resins can be mentioned.

The amount of resin contained in the charge generation layer is preferably 80% by weight or less, preferably 40% by weight or less.

Solvents used during coating include alcohols such as methanol, ethanol, and isopropanol, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone, amides such as N,N-dimethylformamide and N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane,
Ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate.

Examples include aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichlorethylene, and aromatic hydrocarbons such as benzene, toluene, xylene, ligroin, monochlorobenzene, and dichlorobenzene. .

Coating is done by dip coating method, spray coating method,
spinner coating method, bead coating method, Meyer bar coating method, blade coating method,
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 charge generation substance as possible to obtain sufficient absorbance and to shorten the range of the generated charge carriers. A thin film layer having a thickness of .01 to 1 p is desirable.

This means that most of the incident light is absorbed by the charge generation layer, generating many charge carriers, and that the generated charge carriers are injected into the charge transport layer without being deactivated by recombination or 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 conductive substrate.

Examples of the substrate having a conductive layer include aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium molybdenum, chromium,
Examples include titanium, nickel, indium, gold, platinum, etc. Others include plastics (e.g. Polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate.

acrylic resin, polyfluoroethylene, etc.), conductive particles (e.g. carbon black, silver particles, etc.) coated on plastic with a suitable binder, substrates in which plastic or paper is impregnated with conductive particles, and conductive polymers. Examples include plastics that have

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

The undercoat layer may be made of 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 be formed.

The thickness of the undercoat layer is 0.1 to 5 mm, preferably 0.5 mm.
A range of 3 to 3 is suitable.

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 of the present invention is
Because it has hole transport properties, it is necessary to charge the surface of the charge transport layer negatively, and when it is exposed to light after being charged, the holes generated in the charge generation layer are injected into the charge transport layer in the exposed area, and then reach the surface and become negatively charged. The charge is neutralized, the surface potential is attenuated, and an electrostatic contrast is created between the surface potential and the unexposed area. It is necessary to use positively charged toner during development.

In another embodiment of the present invention, disazo pigments or pyrylium dyes, thiapyrylium dyes, selenapyrylium dyes, and benzobyrylium dyes disclosed in U.S. Pat. lium dye, benzothiapyrylium dye,
It can also be used as a naphtopyrilli-sensitizer.

In another embodiment, a eutectic complex of a pyrylium dye and an electrically insulating polymer having a fullkylidene diarylene moiety as disclosed in U.S. Pat. No. 3,684,502 may be used as a sensitizer.

This eutectic complex is composed of, for example, 4-[4-bis-(2-chloroethyl)aminophenyl]-2,6-cyphenylthiavirillium perchlorate and poly(4,4°-isopropylidene diphenylene carbonate). with halogenated hydrocarbon solvents (e.g. dichloromethane, chloroform,
Carbon tetrachloride, l.

1-dichloroethane, 1.2-dichloroethane, 1.1
．． 2-trichloroethane, chlorobenzene, fromobenzene, 1,2-dichlorobenzene) and then dissolved in a non-polar solvent (e.g. hexane, octane, decane, 2-dichlorobenzene).
, 2,4-trimethylbenzene, ligroin) as a particulate eutectic complex.

The electrophotographic photoreceptor in this specific example includes styrene-butadiene copolymer, silicone resin, vinyl resin, vinylidene chloride-acrylonide IJ JL/copolymer,
Styrene-7crylonitrile polymer, 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 for electrophotographic copying machines, but also for laser printers, CRT printers,
It is also widely used in electrophotographic application fields such as electrophotographic plate making systems.

[Example] Example 1 β-type copper phthalocyanine (trade name: L i On OIBl
ue NCB Taner, Toyo Ink Manufacturing Co., Ltd.)
7 g of purified pigment by refluxing in water, ethanol and benzene sequentially, and purified by filtration, 14 g of Polyester Adhesive 49000 (trade name: 20% solids, manufactured by DuPont)
, 35 g of toluene, and 35 g of dioxane were mixed and dispersed in a ball mill for 6 hours to prepare a coating liquid. This coating liquid was applied onto an aluminum sheet using a Mayer bar to a dry film thickness of 0.5 g to form a charge generation layer.

Next, as a charge transport material, 7 g of the hydrazone compound of Compound Example (9) and 7 g of polycarbonate (trade name Panlite -1300, manufactured by Teijin ■) were mixed with 3 g of tetrahydrofuran.
A solution obtained by stirring and dissolving 5 g of chlorobenzene and 35 g of chlorobenzene in a mixed solvent was applied onto the charge generation layer using a Mayer bar so that the dry film thickness was 11 mm, resulting in a photosensitive layer with a two-layer structure. An electrophotographic photoreceptor having layers was prepared.

This electrophotographic photoreceptor was statically charged with corona at 15 KV using an electrostatic copying paper testing device Model Jl-3P-428 manufactured by Kawaguchi Denki ■, held in a dark place for 1 second, and then charged at an illuminance of 2.5 cm ux. It was exposed to light and the charging characteristics were measured.

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

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when the electrophotographic photoreceptor prepared above is repeatedly used, it was pasted on the photosensitive drum cylinder of a PPC copier (trade name: NP-1502, manufactured by Canon Co., Ltd.). , 50,000 on the same aircraft
Copies were made, and changes in bright area potential (VL) and dark area potential (Vo) were measured at the initial stage and after 50,000 copies were made.

In addition, instead of the compound in the above-mentioned exemplified compound example (9), the structural formula
○: Using the hydrazone compound of INS, by exactly the same operation,
Comparative sample 1 was prepared and measured in the same manner.

The results are shown below.

VO(-V)Vl (-V)El/2 (lux, 5e
c) Example 1 600 590 1°9 Comparative sample 1 610 600 3.3 Initial After 50,000 sheets durability Example I Vo (-V) 700 680VL (-V
) 110 145 Comparative sample I VD(-V) 695 655VL
(-V) 150 290 From the above results, it can be seen that the electrophotographic photoreceptor of the present invention has high sensitivity and extremely good potential stability because the hydrazone compound has a skeleton centered on dicarbazolyl.

Examples 2 to 18 In this example, hydrazone compound examples (1), (2), and (5) were used in place of the charge transport substance used in Example 1.
, (10), (12), (15), (18), (22)
, (31), (33).

(44), (48), (53), (54), (55),
An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the compounds (62) and (72) were used, and the pigment exemplified (44.) was used as the charge generating substance.

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

2 (1) 610 600 2.23
(2) 605 695 2.04 (5
) 600 590 2.45 (10)
610 600 2.76, (12)
605 590 2.07 (15) 6
00 590 3.08 (1B)
595 585 2.09 (22)
600 590 2.110 (31)
605 595 2.011 (33)
610 600 1.712 (44
) 605 595 1.713 (
48) 610 605 1.514
(53) 600 590 2.815
(54) 810 600 1.51
6 (55) 600 590 2.
517 (62) 605 Boo
2.018 (72) 600 5
85 1.3 initial period After 50,000 sheets durability 11 700 Zoo 680
130 Example 19 An ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 m of water) was coated on an aluminum cylinder by dip coating, and dried to form a subbing layer with a coating amount of 1.0 g and 7 m2. was formed.

Next, 1 part by weight of exemplified pigment (38) as a charge-generating substance, 1 part by weight of butyral resin (trade name Kosuretsu BM-2, manufactured by Sekisui Chemical Co., Ltd.) and 30 parts by weight of isopropyl alcohol were dispersed in a ball mill for 4 hours. This dispersion was applied onto the previous subbing layer by a dip coating method and dried to form a charge generating layer. The thickness of this film was 0.3 g.

Next, 1 part by weight of the charge transport material of Hydrazone Compound Example (8), 1 part by weight of polysulfone (P-1700, manufactured by UCC), and 6 parts by weight of monochlorobenzene were mixed and dissolved by stirring with a stirrer. This liquid was applied onto the previous charge generation layer by a dip coating method and dried to form a charge transport layer. The film thickness was 12 tiles.

A corona discharge of 15 KV was applied to the photoreceptor thus prepared.

The surface potential (initial potential Vo) at this time was measured. 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 amount of exposure (El/2 J/cm2) required to attenuate the potential VK after dark decay to 172.

At this time, a gallium/aluminum/arsenic ternary semiconductor laser (output 5 mW, oscillation wavelength 78 mW) was used as a light source.
0 nm) was used. Show the results.

vow-755V Potential holding rate (■/Vo X100): 94%E 1
/2: 1,6 gJ/cm Laser beam printer (product name: LBP-L), which is a reversal development electrophotographic printer equipped with the same semiconductor laser as above.
A photoreceptor of the present invention was used instead of the photoreceptor of Canon X, and an actual image forming test was carried out under the conditions shown below.

Surface potential knee after primary charging: 700 V, surface potential knee after image exposure: 150 V (exposure amount: 1.5 J/cm2), transfer potential: +700 V, developer polarity: negative polarity, process speed: 50 mm/sec.

Development conditions (development bias) knee 450V, image exposure scan method: image scan, - exposure before next charging: 50! L
Full red exposure of ux and see.

Image formation was performed by line scanning a laser beam in accordance with character signals and image signals, and good prints of both characters and images were obtained.

Example 20 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and 5 g of the substance of the hydrazone compound example (25) were added to polyester (same as above) toluene-dioxa 7 ( 50:50) solution 10
The mixture was mixed to 0 mfL 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 mm.

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 600V, Vl knee 590V
VE 1/2: 2, 51 uX, S
eC initial v,, VL knee 140V after 50,000 sheets durability VD knee 670V, VL knee 170V Example 21 An ammonia aqueous solution of casein (casein 1) was placed on an aluminum plate.
1.2g, 28% ammonia water 1g, water 222 mfL
) was applied with a Mayer bar and dried to form an adhesive layer with a film thickness of IJL.

Next, 5 g of the disazo pigment of the charge generating substance example (16) and 2 g of butyral resin (butyralization degree 63%) were dispersed with a solution dissolved in 95 ml of ethanol, and then coated on the adhesive layer, and the film thickness after drying was A charge generation layer was formed with a charge generation layer of 0.4 JL.

Next, a solution prepared by dissolving 5 g of the substance of the hydrazone compound example (35) and 5 g of poly-4,4' dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 30,000) in 150 mJl of dichloromethane was placed on the charge generation layer. An electrophotographic photosensitive unit was prepared by coating and drying to form a charge transport layer having a film thickness of 11 μl.

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

vo: -610V, vi knee 600V
El/2: 1. 8uux, sec first
VD Knee 695V, VL Knee 100V After 50,000 sheets durability VD Knee 675V, VL Knee 130V Example 22 A 0.2 mm thick molybdenum plate (substrate) whose surface was cleaned 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 a high frequency of 5 MHz was applied to the zero-order induction coil, which was stabilized at 0.5 torr by adjusting the gas flow rate and the main valve of the deposition tank. Turn on the power and generate a glow discharge inside the coil in the tank for 30 minutes.
The input power was set to W. An amorphous silicon film was grown on the substrate under the above conditions, and after the same conditions were maintained until the film thickness reached 2 μl, glow discharge was stopped. After that, turn off the heater and high frequency power supply, wait until the substrate temperature reaches 100℃, close the hydrogen gas and silane gas outflow valves,
Once the inside of the tank was lowered to 10-5 torr or less, the pressure was returned to atmospheric pressure and the substrate was taken out.

Next, a charge transport layer was formed on this amorphous silicon layer in the same manner as in Example 1 except that the above hydrazone compound example was used as a charge transport material.

The photoreceptor created in this way was installed in a charging exposure experiment equipment,
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, by cascading a positively charged developer (including toner and carrier) onto the photoreceptor surface,
A good toner image was obtained on the surface of the photoreceptor.

Example 23 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and poly(4,4
'-Isopropylidene diphenylene carbonate) 3g
After sufficiently dissolving and in 200 mal of dichloromethane,
100ml of toluene was added to precipitate the eutectic complex. After filtering off this precipitate, dichloromethane was added to dissolve it again, and then n-hexane LOOmi 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 in a ball mill for 6 hours. After drying, this dispersion was applied onto an aluminum plate having a casein layer using a Mayer bar to a film thickness of 0.4 l to form a charge generation layer.

Next, the example of the hydrazone compound (4) which is a charge transport substance is
A charge transport layer was formed on the charge generation layer in the same manner as in Example 1 except that the substance No. 0) was used.

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

The results are shown below.

vo knee 590V, vi knee 580VEl
/2: 1, Blux, sec initial V o: -690V, V L: -100V
After durability of 50,000 sheets Vo knee 670V, VL knee 135V Example 24 5 g of the same eutectic complex used in Example 23 and 5 g of the substance of the hydrazone compound example (50) were mixed with polyester (
The mixture was added to 150 mJl of tetrahydrofuran solution (same as above) and thoroughly mixed and stirred.

This liquid was applied onto an aluminum sheet using a Mayer Parr so that the film thickness after drying would be 15 particles.

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

vo knee 610V, V, knee 600VEl/2:2
．． 51ux, sec Initial Vo knee 700V, VL knee 120V, after 50,000 sheets durability Vo knee 680V, VL knee 155V [Effects of the invention] The electrophotographic photoreceptor of the present invention has improved performance by using a specific hydrazone compound as a charge transport material. , high sensitivity, and high durability (significantly less potential fluctuation due to repeated use).
Moreover, it has the remarkable effect of being applicable to a wide range of electrophotographic fields.

Claims (1)

[Claims] (1) An electrophotographic photoreceptor characterized by having a layer containing a hydrazone compound represented by the following general formula. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ In the formula, A is 3,3'-dicarbazole, 1,3'-dicarbazole, or 9,9'-dicarbazole, which may have a substituent. Represents a divalent or trivalent organic group derived, R_1 represents a hydrogen atom, an alkyl group, an aralkyl group that may have a substituent, an aryl group, or a heterocyclic group, R_2 and R_3 represent an alkyl group, Indicates an aralkyl group, an aryl group, or a heterocyclic group which may have a substituent. Furthermore, R_2 and R_3 represent residues that combine with the central nitrogen atom to form a 5- to 6-membered ring. n is an integer of 2 or 3.