JPH0354342B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more specifically, an electrophotographic photoreceptor with improved electrophotographic properties such as sensitivity, fluctuations in dark and bright potentials upon repeated use, and optical memory effect. Regarding. Conventionally, electrophotographic photoreceptors using a eutectic complex of a pyrylium dye and a polymer containing an algylidene diarylene moiety as a photoconductor have been disclosed, for example, in US Pat. No. 3,684,502 and Australian Publication No. 87757/
It is disclosed in Publication No. 75, etc. In particular, in the above-mentioned Australian Publication No. 87757/75, in an electrophotographic photoreceptor in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer, the charge generation layer contains the above-mentioned eutectic complex, and the charge transport layer carbazole,
Carbazoles such as N-ethylcarbazole,
Polyvinylcarbazoles such as poly-N-vinylcarbazole and halogenated polyvinylcarbazole, monoarylamines, diarylamines,
Arylamines such as triarylamine, polyarylalkane, strong Lewis base materials such as tetraphenylpyrene, perylene, fluorene, fluorenone, phthalic anhydride, 2,4,
7-trinitro-9-fluorenone, 2,4,
It has been proposed to contain strong Lewis acids such as 5,7-tetranitrofluorenone, trinitroanthracene, and dinitroanthraquinone. However, the conventional electrophotographic photoreceptors described above are not satisfactory in terms of sensitivity, and furthermore, among the electrophotographic characteristics, fluctuations in potential during repeated charging-exposure operations, especially dark area potential and bright Since the partial potential varies greatly, it has the disadvantage that it cannot provide stable images over a long period of time. An object of the present invention is to provide an electrophotographic photoreceptor that eliminates the above-mentioned drawbacks. Another object of the present invention is to provide an electrophotographic photoreceptor having good electrophotographic properties. Another object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity characteristics, good dark decay characteristics, and good initial potential characteristics. These objects of the present invention are achieved by an electrophotographic photoreceptor containing a hydrazone compound and a eutectic complex of a pyrylium dye and a polymer containing an alkylidene arylene moiety. In a preferred embodiment of the present invention, a charge generation layer containing the aforementioned eutectic complex formed on a conductive layer;
a charge transport layer electrically connected to the layer;
This charge transport layer is characterized by using a hydrazone compound as a charge transport material.
The charge generation layer contains as much of the eutectic complex as possible to obtain sufficient absorbance and is a thin film layer, for example less than 5 microns, preferably 0.01 microns, to shorten the range of the generated charge carriers. It is preferable to form a thin film layer having a thickness of micron to 1 micron. This means that most of the incident light is absorbed by the charge generation layer and generates a large number of charge carriers, and that the generated charge carriers are not deactivated by recombination or trapping, and the charge transport layer This is due to the need to inject. The charge transport layer is electrically connected to the charge generation layer described above, and has the function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. ing. 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. The charge generation layer used in the present invention is an organic solvent (such as dichloromethane, chloroform, carbon tetrachloride,
The eutectic complex is dissolved in halogenated hydrocarbons such as 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, bromobenzene, and 1,2-dichlorobenzene. obtained by reacting under conditions to form and then adding non-polar liquids (e.g. hydrocarbons such as hexane, octane, decane, dodecane, toluene, 2,2,4-trimethylpentane, ligroin, etc.) The dispersion obtained by dispersing the eutectic precipitate in a suitable binder (e.g. polyvinyl butyral, polyvinyl acetal, polyester, polycarbonate, polyamide, polyurethane, phenolic resin) is applied to form a discontinuous coating phase; A continuous phase pyrylium dye-polymer composition having repeating alkylidene arylene units is applied by applying the solution before precipitation with the addition of the non-polar liquid described above, followed by application of toluene. can form a cohesive eutectic film. Methods for forming these eutectic complexes are disclosed in US Pat. No. 3,684,502, Australian Publication No. 87757/75, and the like. When forming a coating layer containing a eutectic complex, coating methods include dip coating, spray coating, spinner coating, bead coating, Meyer bar coating, blade coating, extrusion hopper coating, and roller coating. This can be done using a coating method such as a 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 30℃~
It can be carried out at a temperature of 200° C. for a time ranging from 5 minutes to 2 hours, either stationary or under ventilation. The pyrylium dyes forming the eutectic complex used in the present invention can be particularly represented by the following general formulas (1) to (4), and are generally pyrylium salts, thiapyrylium salts, selenapyrylium salts, and benzopyrylium salts. ,
It includes dyes of the pyrylium salt series such as penzothiapyryllium salt, penzoselenapyrylium salt, naphthopyryllium salt, naphthothiapyrylium salt, and naphthoselenapyryllium salt. general formula In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each represent (a) a hydrogen atom, (b) an alkyl group, particularly an alkyl group having 1 to 15 carbon atoms: for example, methyl, ethyl, propyl, Isopropyl, butyl, t-butyl, amyl, isoamyl, hexyl, octyl, nonyl, dodecyl (c) Alkoxy group: For example, methoxy, ethoxy, propoxy, butoxy, acyloxy, hexoxy, octoxy (d) Aryl group: phenyl, α- Naphthyl, β-
Naphthyl (e) substituted aryl group: tolyl, xylyl, biphenyl, ethyl phenyl, methoxyphenyl, ethoxyphenyl, amyloxyphenyl, dimethoxyphenyl, diethoxyphenyl, hydroxyphenyl, chlorophenyl, dichlorophenyl, bromophenyl, Dibromophenyl, nitrophenyl, diethylaminophenyl, dimethylaminophenyl, dibenzylaminophenyl (f) Styryl group or 4-phenyl-1,3-butadienyl group: styryl, 4-phenyl-1,3
-butadienyl (g) substituted styryl group or 4-phenyl-1,3-
Butadienyl group: methoxystyryl, dimethoxystyryl, ethoxystyryl, diethoxystyryl, dimethylaminostyryl, diethylaminostyryl, 4-(P-dimethylaminophenyl)-1,3-butadienyl, 4-(P-diethylaminophenyl)- 1,3-Butadienyl (h) R ₁ and R ₂ as well as R ₄ and R ₅ are bonded to form a benzene (i) substituted or unsubstituted heterocyclic group, such as 3-carbazolyl, 9-methyl-3-carbazolyl, 9
-Ethyl-3-carbazoyl and 9-carbazolyl rings can be formed. X represents an oxygen atom, a sulfur atom, or a selenium atom, and Z represents an anion such as perchlorate, fluoroborate, iodide, chloride, bromide, sulfate, periodide, P-
Represents toluene sulfonate, etc. Y ₁ and Y ₂ represent a hydrogen atom, an alkyl group (eg, methyl, ethyl, propyl, butyl, amyl, etc.) or an aryl group (eg, phenyl, naphthyl). m is 0, 1 or 2. However, m is 2
Y ₁ may be the same or different. Typical pyrylium dyes represented by general formula (1) are shown below. Representative pyrylium dyes represented by general formula (2) are as follows. Further, representative examples of the pyrylium dye represented by the general formula (3) or (4) are as follows. A polymer having a repeating unit of an alkylidene diarylene moiety that forms a eutectic complex with these pyrylium dyes has, for example, the general formula (5). It can be shown as In the formula, R ₇ and R ₈ are a hydrogen atom, an alkyl group (methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl, hexyl, octyl, nonyl, decyl), a substituted alkyl group (trifluoromethyl), Aryl group (phenyl, naphthyl), substituted aryl (tolyl, xylyl, ethyl phenyl, propylphenyl, amyl phenyl, chlorophenyl, dichlorophenyl, bromophenyl), and R ₇ and
They can be combined at R ₈ to form cycloalkanes such as cyclohexyl or polycycloalkanes such as norbornyl. _R6 and _R9
is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms,
Represents a halogen atom (chloro, bromo, iodo). R ₁₀ is a group selected from divalent residues consisting of [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] [Formula] or [Formula]. Representative polymers are as follows. Polymer No. Example 1:
Poly(4,4'-isopropylidene diphenylene- CO -1,4-cyclohexyl-dimethyl carbonate) 2:
Poly(3,3'-ethylenedioxyphenylenethiocarbonate) 3:
Poly(4,4'-isopropylidene diphenylene carbonate- CO -terephthalate) 4:
Poly(4,4'-isopropylidene diphenylene carbonate) 5:
Poly(4,4'-isopropylidenephenylenethiocarbonate) 6:
Poly(2,2-butanebis-4-phenylene carbonate) 7:
Poly(4,4'-isopropylidene diphenylene carbonate-block-ethylene oxide) 8:
Poly(4,4'-isopropylidene diphenylene carbonate-blocked tetramethylene oxide) 9:
Poly[4,4'-isopropylidene bis(2-methylphenylene)-carbonate] 10:
Poly(4,4'-isopropylidenephenylene-
CO-1,4-phenylene carbonate) 11:
Poly(4,4'-isopropylidene diphenylene- CO -1,3-phenylene carbonate) 12:
Poly(4,4'-isopropylidene diphenylene- CO -4,4'-diphenylene carbonate) 13:
Poly(4,4'-isopropylidene diphenylene- CO -4,4'-oxydiphenylene carbonate) 14:
Poly(4,4'-isopropylidene diphenylene- CO -4,4'-carbonyl-diphenylene carbonate) 15:
Poly(4,4'-isopropylidene diphenylene- CO -4,4'-ethylene diphenylene carbonate) 16:
Poly[4,4'-methylenebis(2-methylphenylene)carbonate] 17:
Poly[1,1-(P-bromophenylethane)
Bis(4-phenylene) carbonate] 18:
Poly[4,4'-isopropylidene diphenylene- CO -sulfonylbis-(4-phenylene) carbonate] 19:
Poly[4,4'-isopropylidene bis(2-chlorophenylene)-carbonate] 20:
Poly(hexafluoroisopropylidene-4)
−phenylene carbonate) 21:
Poly(4,4'-isopropylidene diphenylene-4,4'-isopropylidene dibenzoate) 22:
Poly(4,4'-isopropylidene dibenzyl-
4,4′-isopropylidene dibenzoate) 23:
Poly[2,2-(3-methylbutane)bis-4
−Phenylene carbonate] 24:
Poly[2,2-(3,3-dimethylbutane)bis-4-phenylene carbonate] 25:
Poly(1,1-[1-(naphthyl)]bis-4-
Phenylene carbonate) 26:
Poly[2,2-(4-methylpentane)bis-
4-Phenylene carbonate] The hydrazone compound in the charge transport layer is generated in the charge generation layer in the presence of an electric field and can transport the injected charge carriers to the surface of the coating layer, especially for electromagnetic waves to which the charge generation layer is sensitive. Preferably, it is substantially insensitive to the wavelength range. But for example He
-When using a laser light source such as a Ne laser (oscillation wavelength 632.8nm), a He-Cd laser (oscillation wavelength 441.6nm), or a Ga-Al-As semiconductor laser (oscillation wavelength 780nm), it is insensitive to the laser wavelength. It is fine as long as it is gender. The term "electromagnetic waves" as used herein includes a broad definition of "light rays" including gamma rays, X-rays, ultraviolet rays, visible light, near infrared rays, infrared rays, far infrared rays, and the like. When the photosensitive wavelength range of the charge transport layer matches or overlaps that of the charge transport layer, charge carriers generated in both trap each other, resulting in a decrease in sensitivity. In addition, it has been proposed to use ionization potential as a guideline for selecting charge transport materials;
In fact, by repeating many experiments,
The reality is that the charge transport material to be used is selected. The charge transport layer used in the present invention is preferably formed by applying a solution of a hydrazone compound and a binder dissolved in a suitable solvent and drying the solution. Examples of the binder used here include polysulfone, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate, polyurethane, acrylonitrile resin, or repeating units of these resins. Copolymer resins containing two or more of these, such as styrene-maleic acid copolymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-
Examples include acrylonitrile copolymers, and polyester resins and polycarbonates are particularly preferred. Furthermore, photoconductive polymers that themselves have charge transporting ability, such as poly-N-vinylcarbazole, can also be used as binders. The blending ratio of this binder and the hydrazone compound is 10 parts by weight of the charge transport compound per 100 parts by weight of the binder.
It is preferable to set it to 500 weight. Since the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Typically it is between 5 microns and 30 microns, with a preferred range between 8 microns and 20 microns. When forming the charge transport layer by coating, an appropriate coating method as described above can be used. Further, the solvent used in forming the charge transport layer of the present invention includes many useful organic solvents. Typical examples include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, and chlorobenzene, acetone, and
- Examples include ketones such as butanone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride, cyclic or linear ethers such as tetrahydrofuran and ethyl ether, and mixed solvents thereof. can. 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,
Various fluorocarbons, silicone oil, silicone rubber or dibutylhydroxytoluene,
2,2'-methylene-bis-(6-t-butyl-4
-methylphenol), α-tocopherol, 2
-t-octyl-5-chlorohydroquinone,
Examples include phenolic compounds such as 2,5-di-t-octylhydroquinone. The hydrazone compound used in the present invention is particularly preferably a compound represented by the following general formula (6) or (7). general formula In the formula, A is (a) aryl group: phenyl, α-naphthyl, β-
Naphthyl, anthralyl, pyrenyl (b) Substituted aryl group: 4-dimethylaminophenyl, 4-diethylaminophenyl, 4-dipropylaminophenyl, 4-dibutylaminophenyl, 4-dibenzylaminophenyl, 4- Diphenylaminophenyl, 4-methoxyphenyl, 2-methoxy-α-naphthyl, 4-methoxy-α-naphthyl, 2,4-dimethoxyphenyl, 2-ethoxy-4-diethylaminophenyl, 4-bromo- 9-antralyl, 4-dimethylamino-9-antralyl (c) Heterocyclic group: dibenzofuran, carbazole,
indole, thiophene, furan, pyrrole,
Pyrazole, acridine, xanthene, thioxanthene, phenothiazine, pyridine, phenoxazine, benzimidazole, thiazoline,
Thiazole, benzothiazole, naphthothiazole, oxazoline, oxazole, benzoxazole, naphthoxazole, 1,3,4
- Monovalent heterocyclic group derived from a heterocycle such as oxadiazole, 1,3,4-thiadiazole, triazole, quinoline, etc. (d) Substituted heterocyclic group: methyl,
Alkyl groups such as ethyl and propyl, halogen atoms such as chlorine and bromine, methoxy, ethoxy,
Alkoxy groups such as propoxy, aryl groups such as phenyl, tolyl, xylyl, benzyl,
Aralkyl groups such as phenethyl, hydroxy,
The heterocyclic group R ₁₃ substituted with one or more groups such as carboxyl or atoms is a hydrogen atom, an aryl group (e.g., phenyl, naphthyl, etc.) or a substituted aryl group (e.g., 4-dimethylaminophenyl, 4-diethylaminophenyl, etc.). enyl, 4-dipropylaminophenyl, 4-methoxyphenyl, 4-ethoxyphenyl, 2-methylphenyl, 2,4-dimethoxyphenyl, etc.), alkyl groups (e.g. methyl, ethyl, propyl, isopropyl, butyl) , isobutyl, t-butyl, amyl, t-amyl, hexyl, cyclohexyl, octyl), substituted alkyl groups (e.g., 2-hydroxyethyl, 3-hydroxypropyl, 2-methoxyethyl, 3-methoxypropyl, 2-cyanoethyl, 3-cyanopropyl, carboxymethyl, 2-carboxyethyl, 2-chloroethyl, 3-chloropropyl),
Aralkyl groups (e.g. benzyl, phenethyl,
3-phenylpropyl, α-naphthylmethyl, β
-naphthylmethyl) or a substituted aralkyl group (eg methoxybenzyl, ethoxybenzyl, hydroxybenzyl, chlorobenzyl, bromobenzyl, methylbenzyl, dimethylbenzyl, dimethylaminobenzyl). _R11 , _R12 and _R14
is an alkyl group such as methyl, ethyl, propyl, butyl, amyl, phenyl, α-naphthyl, β
- Aryl groups such as naphthyl, substituted aryl groups such as tolyl, xylyl, ethyl phenyl, methoxyphenyl, ethoxyphenyl, hydroxyphenyl, aralkyl groups such as benzyl, phenethyl, or methoxybenzyl, ethoxybenzyl,
Indicates substituted aralkyl groups such as hydroxybenzyl, methylbenzyl, and ethylbenzyl. n is 0
Or 1. Z is a substituted or unsubstituted heterocycle (e.g., oxazole, benzoxazole, naphthoxazole, thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole,
Indicates the atomic groups necessary to complete a compound (naphthoselenazole, quinoline, pyridine, indole, etc.).
Examples of the substituent atoms or groups include atoms or groups that can be substituted for the above-mentioned (d) substituted heterocyclic group. Representative examples of hydrazone compounds that can be used in the present invention are listed below. Hydrazone compound (corresponding to general formula (6)) Representative examples of the hydrazone compound represented by general formula (7) are as follows. These hydrazone compounds can be used alone or in combination of two or more. 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. As the substrate having the conductive layer, materials that are themselves conductive can be used, such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum. In addition, plastics (such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic, resin, polyethylene fluoride, etc.), conductive particles (e.g. carbon black,
A substrate made of plastic coated with silver particles (silver particles, etc.) together with a suitable binder, a substrate made of plastic or paper impregnated with conductive particles, a plastic containing 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 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. The thickness of the undercoat layer is 0.1 micron to 5 micron.
Preferably, 0.5 micron to 3 micron is appropriate. When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, it is necessary to charge the surface of the charge transport layer negatively, and when exposed to light after charging, holes generated in the charge generation layer are generated in the exposed area. is injected into the charge transport layer, which then reaches the surface and neutralizes the negative charge, resulting in a decay of the surface potential and an electrostatic contrast with the unexposed areas. During development, it is necessary to use a positively charged toner, contrary to the case where an electron transport material is used. In another embodiment of the present invention, a photosensitive composition containing a hydrazone compound in the discontinuous phase or continuous phase eutectic complex composition described above may be used. The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser printers and CRTs.
It can also be widely used in electrophotographic applications such as printers. Hereinafter, the present invention will be explained according to examples. Example 1 Ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 ml of water)
was applied with a Mayer bar so that the film thickness after drying was 1.0 microns, and dried. Next, 1 g of pyrylium salt of compound No. 10 (2,4-diphenyl-6-(4-N,N-dimethylaminostyryl) pyrylium perchlorate) and poly(4,4'- 10 g of isopropylidene diphenylene carbonate) was added to 420 ml of dichloromethane and stirred for 4 hours to dissolve and form a eutectic complex composition. This eutectic complex composition is applied onto the previously formed casein layer using an extrusion hopper coating machine so that the film thickness after drying is 0.8μ, and after drying, toluene is overcoated to form an aggregated layer. A charge generation layer consisting of a crystalline complex film was formed. Next, compound No. (4), 4-N,N-diethylaminobenzaldehyde-N-α-naphthyl-N-
Add 5 g of phenylhydrazone and 5 g of polymethyl methacrylate resin (number average molecular weight 100,000) to benzene.
The solution was dissolved in 70 ml and applied onto the charge generation layer using a Mayer bar so that the film thickness after drying was 12 microns, and dried to form a charge transport layer. The electrophotographic photoreceptor thus prepared was statically charged with corona at -5 KV using an electrostatic copying paper tester Model SP-428 manufactured by Kawaguchi Electric Co., Ltd.
After keeping it in the dark for 10 seconds, it was exposed to light at an illuminance of 5 lux to examine the charging characteristics. As for charging characteristics, the surface potential (V ₀ ) and the exposure amount (E1/2) required to attenuate the potential (V ₁₀ ) by 1/2 when dark decayed for 10 seconds were measured. The results are shown in Table 1. Furthermore, in order to measure the fluctuations in bright area potential and dark area potential during repeated use, the photoreceptor fabricated in this example was charged with a -5.6KV corona charger and an illuminance of 15lux.
It was attached to the cylinder of an electrophotographic copying machine equipped with an exposure optical system, a developing device, a transfer charger, a static elimination exposure optical system, and a cleaner. This copier is
The structure is such that an image is obtained on the transfer paper as the cylinder is driven. Using this copying machine, the initial bright area potential (V _L ), dark area potential (V _D ) and
The light potential (V _L ) and dark potential (V _D ) were measured after 5000 uses. The results are shown in Table 2. Table 1 V ₀ : -570 volts V ₁₀ : -550 volts E1/2: 4.5 lux・sec [Table] Examples 2 to 13 In place of the pyrylium salt used in Example 1,
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the pyrylium salt shown in the table was used. The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1. These results are summarized in the fourth
Shown in the table. Table 3 Example Pyrylium Dye 2 Pyrylium Salt of Compound No. (8) 3 Compound No. (11) 〃 4 Compound No. (13) 〃 5 Compound No. (19) 〃 6 Compound No. (20) 〃 7 Compound No. (29) 〃 8 Compound No. (31) 〃 9 Compound No. (33) 〃 10 Compound No. (35) 〃 11 Compound No. (37) 〃 12 Compound No. (39) 〃 13 Compound No. (40) [Table] Example 14 A polyvinyl alcohol film having a thickness of 1.1 microns was formed on the aluminum surface of an aluminum vapor-deposited polyethylene terephthalate film. Next, 1 g of pyrylium salt of compound No. 10 and the polymer
No. 3 poly(4,4'-isopropylidene diphenylene carbonate- CO -terephthalate) 10g
was added to 450 ml of dichloromethane and thoroughly stirred to dissolve. A eutectic complex precipitate was formed by adding 250 ml of toluene to this solution. This precipitate was washed with dichloroethane. Add 5 g of the precipitate thus obtained to 95 ml of ethanol and 2 g of butyral resin (degree of butyralization: 63 mol%).
was added to the dissolved solution and dispersed with an attritor for 2 hours. This dispersion was applied onto the previously formed casein layer using a Mayer bar so that the film thickness after drying would be 0.5 microns, and dried to form a charge generation layer. Next, compound No. (20) hydrazone compound 5
Dissolve g and 5 g of polymethyl methacrylate resin (number average molecular weight 100,000) in 70 ml of benzene, apply this onto the charge generation layer using a Mayer bar so that the film thickness after drying is 12 microns, dry and charge. A transport layer was formed. The charging characteristics and durability characteristics of the photoreceptor thus prepared were measured in the same manner as in Example 1. The results are shown in Table 7. Table 7 - (1) V ₀ : -590 volts V ₁₀ : -560 volts E1/2: 4.8 lux・sec [Table] Examples 15 to 54 Hydrazone compounds used when producing the photoreceptor of Example 1 above A photoreceptor was prepared in the same manner as in Example 1, except that the hydrazone compounds shown in Table 8 were used instead. The charging characteristics and durability characteristics of these photoreceptors were measured in the same manner as in Example 1. These results are shown in the 8th
Shown in the table. [Table] [Table]

Claims (1)

[Claims] 1. An electrophotographic photoreceptor comprising a hydrazone compound and a eutectic complex of a pyrylium dye and a polymer containing an alkylidene diarylene moiety.