JPS597956A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor having high sensitivity by adding a specified compd. to a charge transfer layer. CONSTITUTION:A compd. represented by the shown general formula is added to charge transfer layr by 0.01-100pts.wt. per 100pts.wt. In the formula, A is an optionally substd. aromatic or heterocyclic group, such as pyridyl, furyl, thienyl, carbazolyl, phenoxazyl, or phenothiazyl; R is cyano, alkoxycarbonyl, optionally substd. aryloxycarbonyl, acyl, aryl, or carbamoyl; and n is 0 or 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrophotographic photoreceptors that provide improved electrophotographic properties.

Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known as photoconductive materials used in electrophotographic photoreceptors. These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, or quickly dissipating the charge when irradiated with light. On the other hand, it has various drawbacks. For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, and pressure.
In particular, when the ambient temperature exceeds 40C, crystallization becomes significant, resulting in drawbacks such as a decrease in charging performance and the appearance of white spots on images. Cadmium sulfide photoreceptors do not have stable sensitivity in humid environments, and zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as roseben gas. They have the disadvantage that they cannot provide stable images over a long period of time because the sensitive dyes undergo charging deterioration due to corona charging and photobleaching due to exposure light.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior 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 obtained, and inorganic photoconductive materials have been lacking in 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, tria IJ-ruvirazoline compounds described in U.S. Pat.
Low molecular weight organic photoconductors such as 9-styrylanthracene compounds described in JP-A-1-94828 and JP-A-51-94829 have been proposed. These low-molecular-weight organic photoconductors can overcome the drawbacks of film-forming properties that have plagued the field of organic photoconductive polymers by appropriately selecting the binder used. However, it cannot be said that it is sufficient in terms of sensitivity.

For these reasons, a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed in recent years. Electrophotographic photoreceptors using this laminated structure as a photosensitive layer can now be improved in terms of sensitivity to visible light, charge retention, surface strength, etc.

Such an electrophotographic photoreceptor is disclosed in US Pat. No. 3,837, for example.
851, No. 3871882, and the like.

However, electrophotographic photoreceptors using conventional organic photoconductors in the charge transport layer have not yet achieved sufficient sensitivity.
During repeated charging and exposure, there is a large variation in bright area potential and dark area potential, and there is an issue to be improved.

SUMMARY OF THE INVENTION The object of the present invention is to provide an electrophotographic photoreceptor which eliminates the above-mentioned drawbacks or disadvantages.

This object of the present invention is achieved by an electrophotographic photoreceptor in which a compound represented by the following general formula (1) is added to a charge transport layer containing a charge transport substance.

In the formula, the human represents an optionally substituted aromatic group or an optionally substituted heterocyclic group.

Examples of aromatic groups include phenyl, naphthyl, anthryl, and the like. Examples of the heterocyclic group include groups such as pyridyl, furyl, chenyl, carbazolyl, phenoxadyl, and fetchacyl.

Substituents for aromatic groups or heterocyclic groups include alkyl groups such as methyl, ethyl, propyl, butyl, alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, and alkyl atoms such as fluorine, chlorine, bromine, and iodine. , cyano group,
Nitro group, methoxycarbonyl, ethoxycarbonyl,
Examples include alkoxycarbonyl groups such as propoxycarboel.

R is cyan group, methoxycarbonyl, etho.

Alkoxycarbonyl groups such as oxycarbonyl, propoxycarbonyl, butoxycarbonyl, aryloxycarbonyl groups such as optionally substituted phenoxycarbonyl and naphthoxycarbonyl, acyl groups such as acetyl, fropionyl, and benzoyl, and aryl groups such as phenyl and naphthyl. Alternatively, it represents a carbamoyl group, and as a substituent for the aryloxycarboel group, acyl group, or aryl group, an electron-withdrawing group such as nitro or cyano is preferable. Examples of substituents for the carbamoyl group include alkyl groups such as methyl, ethyl, propyl and butyl, and aryl groups such as phenyl and naphthyl.

n represents an integer of 0 or 1.

Next, main specific examples of the compound represented by the general formula (1) will be listed.

The addition rate of the compound represented by general formula (1) to the charge transport substance is 0.01 parts by weight per 100 parts by weight of the charge transport substance.
-100 parts by weight, preferably 0.05-30 parts by weight.

Generally, when an electron-withdrawing substance is added to an electron-donating substance in a charge-transport layer, the absorption of the charge-transport layer shifts to longer wavelengths due to the formation of a charge-transfer complex, resulting in a desensitization effect due to the filter effect and an increase in traps. However, when the compound represented by the general formula (1) is added, the tail of the light attenuation curve specifically becomes sharper, and the photoreceptor is repeatedly charged. The rise in residual potential after exposure is also extremely small, making the electrophotographic photoreceptor extremely useful in practice.

The charge transport materials of the electrophotographic X photoreceptor in which the photosensitive layer of the present invention is functionally separated into a charge generation layer and a charge transport layer include hydrazone compounds, pyrazoline compounds, oxadiazole compounds, styryl compounds, and triphenylmethine. Various charge transporting substances such as N-based compounds and poly-N-vinylcarbazole are used, but particularly preferred materials are hydrazone-based compounds represented by the following general formula (2) and pyrazoline-based compounds represented by the general formula (3). be.

In the general formula, B represents an optionally substituted aryl group such as phenyl, naphthyl, anthryl, pyrenyl, etc., or a heterocyclic group such as furyl, chenyl, pyridyl, carbazolyl, phenoxadyl, fetchacyl, etc., and the substituents include: Halogen atoms such as fluorine, chlorine, bromine, and iodine, methyl,
Alkyl groups such as ethyl, propyl, butyl, methoxy,
Alkoxy groups such as ethoxy, propoxy, butoxy, dimethylamino, diethylamino, dipropylamino, dibutylamino, diphenylamino, dibenzylamino,
Examples include substituted amino groups or cyclic amino groups such as methylphenylamino, ethylphenylamino, ethylbenzylamino, morpholino, piperidino, and pyrrolidino. R1 and R2 represent an optionally substituted alkyl group such as methyl, ethyl, propyl, butyl, an aralkyl group such as benzyl or phenethyl, or an aryl group such as phenyl, naphthyl, anthryl, or pyrenyl; The same substituents as those for B can be mentioned.

The general formula is an aryl group such as phenyl, naphthyl, anthryl, etc., RA, R4, R5, and R6 are an alkyl group such as methyl, ethyl, propyl, butyl, an aralkyl group such as benzyl, phenethyl, an aryl group such as phenyl, naphthyl, etc. Indicates the group.

Next, a specific example of the charge transport material used will be given.

Pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N-phenylhydrazino-6
-Methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-meth IJ Ten-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine, N,N- dPhenylhydrazino-5-methylidene-10-ditylphenoxazine, P-diethylaminobenzaldehyde-N
, N-') Phenylhydrazone, P-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, p-pyrrolidinobenzaldehyde-N,N-
Hydrazones such as diphenylhydrazone, 1,3.3-) IJ methylindolenine-ω-aldehyde-N,N-') phenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone M, 2 .5-bis(P-diethylaminophenyl)-
1,3,4-oxadiazole, 1-phenyl-3-(
P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[quinolyl (2))
-! l -(p-diethylaminostyryl)-s-(
p-diethylaminophenyl)pyrazoline, 1-[pyridyl(2))-3-(P-diethylaminostyryl)-5-(ardiethylaminophenyl)pyrazoline, 1-(6-medoxypyridyl(2))-3-( , P
-diethylaminostyryl)-5-(p-diethylaminophenyl)pyrazoline, 1-[pyridyl(5))
-5~(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[lepidyl(
2) ) -s -(p-diethylaminostyryl)-
5-(P-diethylaminophenyl)pyrazoline, 1-
[Pyridyl(2)) -3-(P-diethylaminostyryl)-4-methyl-5-(P-diethylaminophenyl)pyrazoline, 1-[pyridyl(no)-5-(α
-Methyl-P-diethylaminostyryl)-5-(P-
diethylaminophenyl) hyazoline, 1-phenyl-
5-(P-diethylaminostyryl)-4-methyl-5
-(P-diethylaminophenyl)pyrazoline, 1-phenyl-3-(α-benzyl-ptethylannosteryl)-5-(P-9ethylannophenyl)pyrazoline 4, spiropyrazoline and other pyrazolines, 2 -(P
-diethylaminostyryl)-6-ethylaminobenzoxazole, 2-(P-diethylaminophenyl)
-4-(P-dimethylaminophenyl)-5-(2-1
Oxazole compounds such as 2-(P-diethylaminostyryl)-6-dinithylaminobenzothiazole, bis(4-diethylamino-2-methyl7enyl)-phenylmethane, etc. triarylmethane compounds, 1,1-bis(4-N,N-diethylamine-2-methylphenyl)hebutane, 1,1,2,2-tetrakis(4-N,N
-Polyarylalkanes such as dimethylamine-2-methylphenyl)ethane, triphenylamine, poly-N
Examples include -vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, polyq-vinylphenylanthracene, pyrene-formaldehyde, do resin, and ethylcarbazole formaldehyde resin.

The charge transport layer according to the present invention is preferably formed by applying a solution prepared by dissolving the above charge transport substance, the compound represented by general formula (1), and a binder in a suitable 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 copolymers, styrene-7-nitrile copolymers, styrene-maleic acid copolymers, and the like.

In addition to these various insulating polymers, organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene, and polyvinylpyrene momme can also be used.

The blending ratio of the binder and the charge transport material is 10 parts of the binder.
It is preferable that the amount of the charge transport material is 10 to 500 parts by weight per 0 parts by weight.

The charge transport layer is electrically connected to the underlying charge generation layer and is capable 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. It has a function. In this case, the 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 the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. 'Generally, it is 5 microns to 50 microns,
The preferred range is 8 microns to 20 microns.

The organic solvent used when forming such a charge transport layer is
Depending on the type of binder used, it is preferable to select a binder that does not dissolve the subbing layer below the charge generating layer. Specific organic solvents include alcohols such as methanol, ethanol, and isozolopanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide. Sulfoxides, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether natonoethers, esters such as methyl acetate and ethyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichlorethylene, etc. Aromatics such as benzene, toluene, xylene, refloin, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as a Mayer 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 30°C to 200°C for 5 minutes to 2
It can be carried out stationary or under blown air for a period of time within a range of hours.

The charge transport layer of the present invention can contain various additives. Such additives include diphenyl, i-diphenyl, O-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 generation layer used in the present invention includes heptalene, selenium-tellurium, pyrylium, thiopyrylium dyes, heptalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, pyrantrene pigments, trisazo pigments, disazo pigments, azo pigments, and indigo pigments. Pigments, quinacridone pigments,
Asymmetric quinocyanin, quinocyanin or JP-A-1983
A separate vapor deposited layer or resin dispersion layer selected from a charge generating material such as amorphous silicon described in Japanese Patent No. 143,645 can be used.

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

Charge generating substance (1) Amorphous Noricon (2) Selenium-tellurium (3) Selenium-arsenic (4) Cadmium sulfide (5) 11 Ra■'N5C2FI5 (51) 1 C2)15
c, +■.

1 C2H5C2H3 (54) 1 (G(2)3°CH3(C)4), 0CH3(to) Square-linked methyl dye (59) Parakeet dye (c, ■, A67sooo >
(60f Oi7 Nko dye (0,1,A678800
) (61) β-type copper phthalocyanine (62) (63) (64) (65) The charge generation layer is prepared by dispersing the above charge generation substance in a suitable binder and coating it on the substrate. 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 generating layer by coating can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole and polyvinylanthracene and polyvinylpyrene. can. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and heptalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylic A/amide resin, polyamide, polyvinylpyridine, cellulose resin. Insulating resins include polyurethane resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinylpyrrolidone. The resin contained in the charge generation layer has a weight ratio of 80% by weight or less, preferably 4°% weight tIs or less. Examples of organic solvents used during coating include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and N, N-u methylformamide, N, N-dimethyl acetoand, etc. Amides, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol 7-methyl ether, methyl acetate,
Esters such as 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, dichlorobenzene, etc. When you use something like ``to''.

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 coach ink 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 is preferably a thin film layer, for example less than 5 microns, in order to shorten the range of the generated charge carriers. is preferably a thin film layer having a thickness of 0.011 microfron to 1 micron. 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 transported by recombination or trapping without being deactivated. This is due to the need to inject into the 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, aluminium, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium,
Nickel, indium, gold, platinum, etc. can be used, and in addition, aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. can be used to form a film on the plastic by vacuum deposition (for example, A substrate in which conductive particles (e.g., carbon grains, silver particles, etc.) are coated on plastic with a suitable binder (polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyethylene, etc.), conductive particles A substrate impregnated with plastic or paper, 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 casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
Acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin,
It can be formed from aluminum oxide, etc.

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

When using a photoreceptor in which a conductive IK layer, a charge generation layer, and a charge transport layer are laminated in this order (the compound has a hole transport property, it is necessary to charge the surface of the charge transport layer negatively;
When exposed to light after being charged, holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, and then reach the surface and neutralize the negative charge, resulting in attenuation of the surface potential and the generation of static electricity between the exposed area and the unexposed area. Contrast occurs. 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-cyphenyltheapyrylium perchlorate and poly(4,4'-isopropylidene diphenylene carbonate) are mixed in a halogenated hydrocarbon bed-based solvent (e.g., dichloromethane, dichloroform, tetracarbon i, 1 ,1-')
Chlorethane, 1,2-dichloromethane, t, 1,2-
) IJ dichloromethane, chlorobenzene, furosobenzene, 1.2-i) chlorobenzene) and then dissolved in a nonpolar solvent (e.g., hexane, octane, decane, 2,2.4-)limethylbenzene, ligroin). It is obtained as a particulate eutectic complex by adding . The electrophotographic photoreceptor in this specific example includes styrene-butadiene copolymer, silicon Ii (fat), vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, polymethyl methacrylate, poly-N-butyl methacrylate,
It can be contained as a binder such as polyesters and cellulose esters.

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 the variation in bright area potential and dark area potential is small when repeated charging and exposure are performed.

Hereinafter, the present invention will be explained according to examples.

Example 1 Type 1 Kazushi 7 Talocyanine 7f manufactured by Toyo Ink Manufacturing ■; Product name: Polyester Adhesive 49 manufactured by DuPont
,000 (solid content 20%) J14f; Toluene 55? ;
A coating solution was prepared by mixing dioxane 551 and dispersing it in a ball mill for 6 hours. This coating liquid was applied onto an aluminum sheet using a Mayer bar to give a dry film thickness of 0.5 electrons to form a charge generation layer.

Next, as a charge transport compound, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone 7t and P-
The solution obtained by stirring and dissolving 0.07f of nitrobenzalmalononitrile and 7f of polycarbonate resin (manufactured by Teijin Kasei, trade name: 1300J) in a mixed solvent of 351 tetrahydrofuran and 35f of chlorobenzene was added to An electrophotographic photoreceptor having a photosensitive layer having a two-layer structure was prepared by coating the charge generation layer with Meyer <- to a dry film thickness of 11 microns.(Sample 1) Next, For comparison, an electrophotographic photoreceptor was prepared in exactly the same manner as Sample 1, except that P-2) lobenzalmalononitrile was not added to the charge transport layer. (Comparative sample) The photographic photoreceptor was statically charged with corona at -5 KV using an electrostatic copying paper tester MO (1θt8P-428 manufactured by Kawaguchi Denki Mari) and then charged with corona at 10 KV in the dark.
After being held for a second, it was exposed to light at an illuminance of 5 tux and the charging characteristics were examined.

The charging characteristics include the surface potential (To) and the exposure i (E
'! 4) was measured. The results are shown in Table 1.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when repeatedly used, the photoreceptor prepared in this example was
, 6KV corona charger, exposure amount 12 Lux, sθC
The sticker 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 copying machine is configured to produce an image on transfer paper as a cylinder is driven. Using Jin's copy machine,
Initial light potential (ML) and dark potential (VD) and 50
Bright area potential (Vj) and dark area potential ('
VD ) was measured. The results are shown in Table 2.

Table 1 Table 2 From the above results, Sample 1 in which P-2) lobenzalmalononitrile was added to the charge transport layer had extremely good sensitivity and stability of vp and VL after durability compared to comparative sample 1. The following characteristics are shown.

Examples 2 to 7 In each of these Examples, exemplified compounds of general formula (1) (3)% (5), (7), (12) % (1
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that 5) and (16) were used.

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

Example Vo(-V) B'7'2(Lux, ae
a) 2 570 4.03
590 i44 58
〇 585 610
3.66 580 4.1
7 600 3.92
570 50 570 403
580 20 5+50
304 560 20 55
0 405 600 20
580 306 580
30 570 407 580
20 5i 40 Example 8 Ammonia aqueous solution of casein (casein 1
1.2F, 28q6 ammonia water if, water 222-) was applied using a Mayer par and dried to form an adhesive layer with a film thickness of 1F. Next, 5f of a disazo pigment having the following structure and 2t of butyral resin (degree of butyralization: 63 moles) were dispersed together with a solution of 95% ethanol, and then coated on the adhesive layer to give a film thickness of 0.4 after drying. A charge generation layer of micron size was formed.

Next, 1-phenyl-3-P-diethylaminostyryl-
5-P-jethylaminophenylpyrazoline 5f and P-
Nitrobenzalmalononitrile 0.1f and poly-4,4
'-Dioxydiphenyl-2,2-propane carbonate (viscosity average molecular fil: 30000) A solution prepared by dissolving 5 f in dichloromethane 150 g was applied onto the charge generation layer and dried to form a charge transport layer with a film thickness of 11 microns. An electrophotographic photoreceptor was prepared by forming a sample, and this was designated as Sample 8. For comparison, a sample without the addition of P-nitro-benzalmalononitrile was prepared in the same manner and designated as Comparative Sample 2.

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

The results are shown below.

Sample 8 Comparative sample 2 v(, (-v) 590 580
E% (tux, aec) 3.2
6.4 Sample 8 590 20 570 30 Comparative Sample 2 600 30 570 105 Example 9 A 12 m thick molybdenum plate (substrate) whose surface was cleaned was fixed at a predetermined position in a glow discharge deposition tank. The tank was then evacuated to a vacuum of approximately 5 x 10-dtorr. After that, the input voltage of the heater was increased and the temperature of the molybdenum substrate was stabilized at 1500℃.After that, hydrogen gas and silane gas (15% by volume for hydrogen gas) were introduced into the tank, and the gas flow rate and the main pulp of the evaporation tank were adjusted. The pressure was stabilized at 0.5 torr.Next, 5 MHz high frequency power was applied to the induction coil to generate a glow discharge inside the coil in the tank.
The input power was set to 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, the heating heater and high frequency power supply are turned off, and after waiting for the substrate temperature to reach 100℃, the outflow pulp of hydrogen gas and silane gas is closed, and after the inside of the hinoki is reduced to below 10-5 torr, the pressure is returned to atmospheric pressure and the substrate is removed. I took it out. Next, a charge transport layer was formed on this amorphous silicon film in exactly the same manner as in Example 1.

The photoreceptor obtained in this way was installed in a charging exposure experimental device, and θ
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 10 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate 32 and poly(4,
4'-isopropylidene diphenylene carbonate) 3
After fully dissolving 2 in 200ml of dichloromethane, 100ml of toluene was added to precipitate the eutectic complex. After this precipitate was taken from house to house, dichloromethane was added to redissolve it, and then 100 mt of n-hexane was added to this solution to obtain a precipitate of the eutectic complex.

This eutectic complex 52 was added to 95 ml of a methanol solution containing polyvinyl butyral 2f, 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 so that the film thickness after drying was 0.4 microns to form a charge generation layer.

Next, a coating layer similar to the charge transport layer used in Example 1 was formed on this charge generation layer.

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

VO: 630 (V) K 172: 5.6 (tux, sea)
Initial VD: 595 (-v) VD: 580 (V
) Vr, : 30(-v) VI, :
40(-V) Patent Applicant Canon Co., Ltd. Agent Patent Attorney Yu Kano

Claims (1)

[Scope of Claims] A charge transport layer of a laminated electrophotographic photoreceptor having at least two layers, a charge generation layer and a charge transport layer, has a charge transport layer of the general formula % (in the formula % is an optionally substituted aromatic compound). R represents a group group or an optionally substituted heterobase; R is a cyano group, an alkoxycarbonyl group, an optionally substituted aryloxycarbonyl group, an optionally substituted acyl group, an optionally substituted aryl group; 1. An electrophotographic photoreceptor, characterized in that it contains a compound represented by the following formula (n represents an integer of 0 or 1).