JPS61129653A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and to stabilize potential characteristics at the time of repeated uses by forming a photosensitive layer contg. a specified disazo compd. represented by a specified chemical formula to form an electrophotographic sensitive body. CONSTITUTION:The electrophotographic sensitive body is prepared by forming on the conductive substrate the photosensitive layer contg., a disazo compd. represented by the formula in which each of R1, R2, and R3 is H, alkyl, alkoxy, halogen, or cyano; and at least one of them is not H, and A is a coupler residue having a phenolic OH group. Said photosensitive layer can be divided into an electrostatic charge generating layer and a charge transfer layer as the functionally separated layers and in this case, the disazo pigment of the formula can be used as the charge generating material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor containing a specific disazo pigment.

Electrophotographic photoreceptors using inorganic photoconductors such as selenium, cadmium sulfide, and zinc oxide as photosensitive components have been known so far.

On the other hand, since it was discovered that certain organic compounds exhibit photoconductivity, many organic photoconductors have been developed. For example, poly N-vinylcarbazole, organic photoconducting polymers such as polyvinyl anthracene, carbazole, anthracene, pyrazolines, oquinacyazoles,
Low-molecular organic photoconductors such as hydrazones and polyarylalkane, phthalocyanino pigments, azo pigments, cyanine dyes, polycyclic quinone pigments, perylene pigments, indigo dyes, thioindigo dyes, and squaric acid methine dyes. Pigments and dyes are known. In particular, organic pigments and dyes with photoconductivity are easier to synthesize than inorganic materials, and the variety of compounds that exhibit photoconductivity in an appropriate wavelength range has expanded, making it possible to use a large number of photoconductive materials. Conductive organic pigments and dyes have been proposed.

For example, US Pat. No. 4,123,270, US Pat. No. 42,476
No. 14, No. 4251613, No. 4251614, No. 4256821, No. 4260672, No. 4268596, No. 4278747, No. 429
3628, an electrophotographic photoreceptor using a disazo pigment exhibiting photoconductivity as a charge generation substance in a photosensitive layer functionally separated into a charge generation layer and a charge transport layer is known.

An electrophotographic photoreceptor using such an organic photoconductor can be produced by coating by appropriately selecting a binder, so it is possible to provide an extremely highly productive and inexpensive photoreceptor.
Moreover, while it has the advantage of being able to freely control the sensitive wavelength range by selecting organic pigments, this photoreceptor has problems with sensitivity and durability, and so far only a few have been put into practical use. .

An object of the present invention is to provide a novel electrophotographic photoreceptor.

Another object of the present invention is to provide an electrophotographic photoreceptor having practical high sensitivity characteristics and stable potential characteristics during repeated use.

This object of the present invention is achieved by using a disazo pigment represented by the following general formula (1) in the photosensitive layer.

In the formula, a hydrogen atom, an alkyl group such as methyl, ethyl, propyl, an alkoxy group such as methoxy, ethoxy, glopoxy, butoxy, a halogen atom such as a chlorine atom, a bromine atom, an iodine atom, or a cyano group, R1, R2 and At least one of R3 represents an alkyl group, an alkoxy group, a halogen atom, or a cyano group.

A represents a coupler residue having 7 phenolic hydroxy groups, and more preferred specific examples thereof are represented by the following general formulas (2) to (6).

°ゝX' In the formula, Indicates a residue necessary to form a ring. R4 and 几5 are hydrogen atoms, each optionally substituted alkyl, !E- (methyl, ethyl, propyl, butyl, hydroxyethyl, methoxyethyl, ethoxymethyl, etc.) , aralkyl group (benzyl, phenethyl, naphthylmethyl, methoxybenzyl,
ethoxybenzyl, etc.), aryl fi (phenyl, tolyl, gysylyl, methoxyphenyl, ethoxyphenyl, piphenyl, naphthyl, anthryl, cyanophenyl, chlorophenyl, nitrophenyl), heterocyclic groups (pyridine, carbazole, furan, dibenzofuran, (monovalent groups derived from heterocycles such as thiophene, penzimidozolone, benzthiazole, thiazole)
, or R4 and R5 represent a cyclic amine group bonded together with a nitrogen atom.

■ 1. Yl, Y In the formula, R6 and 1 (+7 is an alkyl group that may each have a substituent (methyl, ethyl, propyl, butyl, hydroxyethyl, methoxyethyl, ethoxymethyl),
It represents an aralkyl group (benzyl, phenethyl, naphthylmethyl, methoxybenzyl, ethoxybenzyl) or an aryl group (phenyl, tolyl, xylyl, biphenyl, naphthyl, anthryl, methoxyphenyl, ethoxyphenyl, cyanophenyl, nitrophenyl). Y habe/
Divalent hydrocarbon groups (-CH2-CH2-, -
CH=CH-, etc.).

By introducing at least one polar group represented by R1+ R2+ R3 into the fluoreno/skeleton, the polarity of the pigment can be changed, and either one of the pigment generation effect and the carrier transportability inside the abrasive generation layer can be improved. In order to improve both, during high sensitivity and durable use,
It is presumed that potential stability is ensured. Regarding the influence of the type of λ substituent of R3 on the sensitivity, halogen-based substituents are preferred, and among them, custom-made chlorine atoms are extremely favorable.

In particular, a disazo pigment represented by the following general formula (7) is suitable for the present invention.

General formula (7) In the formula, R1, R2 and R3 represent a hydrogen atom or a chlorine atom, and % R1* At least one of R2 and RJ3 represents a chlorine atom. R8 represents a hydrogen atom or a chlorine atom.

Representative examples of the disazo pigments used in the present invention are listed below.

/1\
l-\V
-Claw 1h

Do-\\11
\UNO These disazo pigments can be used alone or in combination of 2'a or more. In addition, these pigments can be used, for example (where the formulas R, , R2, and 3 are R1@R of the general formula (1)).
2, R.

(having the same meaning as ) is tetrazotized by a conventional method, and then the corresponding coupler is coupled in the presence of an alkali, or the tetrazonium salt of the diamine is converted into a diamine such as a holactinated salt or a zinc chloride double salt. It can be easily produced by coupling with a coupler in the presence of an alkali in a suitable solvent such as N,N-dimethylformamide, dimethylsulfoxide, etc.

Next, a typical synthesis example of the disazo pigment used in the present invention is shown below.

Synthesis Example 1 (Synthesis of the above-exemplified disazo compound (6)) 5
00ml! 80m of water in a beaker, 16.6fn of concentrated hydrochloric acid
l! (0,19 mol) (0,029 mol) and cooled in an ice water bath7.
The mixture was stirred for 10 f and the liquid temperature was brought to 3°C. Next, sodium nitrite 4
．． A solution of 2P (0,061' mol) in water at 7 rM was added dropwise over 10 minutes while controlling the temperature within the range of 3 to 10°C, and after the dropwise addition was completed, the mixture was stirred at the same temperature for an additional 1 c30 minutes. Carbon was added to the reaction solution and filtered to obtain a tetrazotized solution.

Next, 21! Water 7001111 in a beaker! After dissolving 21f (0.53 mol) of caustic soda,
16.1? (0,061 mol) was added and dissolved.

This coupler solution was cooled to 6°C, and while controlling the liquid temperature at 6 to 10°C, the above-mentioned tetrazotized solution was added dropwise over 30 minutes while stirring.Then, the solution was stirred at room temperature for 2 hours and further left overnight. After filtering the reaction solution, it was washed with water to obtain a crude pigment of 20.47
? I got it. Next, 400m1! Hot filtration was repeated 5 times with N,N-dimethylformamide. Thereafter, purified pigment 19.09f was obtained by heat drying under reduced pressure. Yield is 83%
Met.

Elemental analysis: Calculated value (%) Experimental value (X) C71,1671,11 H3,693,67 N 10.60 10.62C/
4.47 4.41 Although the synthesis method of typical pigments has been described above, other disazo pigments represented by the general formula (1) can be synthesized in the same manner.

In a preferred embodiment of the present invention, an organic photoconductor represented by the general formula (1) can be used as a charge-generating substance in an electrophotographic photoreceptor in which a photosensitive layer is functionally separated into a charge-generating layer and a charge-transporting layer. The charge generation layer contains as much of the organic photoconductor as possible in order to obtain sufficient absorbance, and in order to shorten the range of the generated charge carriers, it is a thin film layer, e.g. Preferably, the thin film layer has a thickness of 0.01 micron to 1 micron. This means that most of the incident light is absorbed by the charge generation layer, generating many charge carriers, and that the generated charge carriers are not deactivated by recombination or trapping, but are transferred to the charge transport layer. It is attributed to the button that it needs to be injected.

The charge generation layer can be formed by dispersing the above-mentioned organic photoconductor in a suitable binder and coating it on the substrate, or it can be obtained by forming a vapor deposited film using a vacuum evaporation device. . The binder 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 photoconducting polymers such as polyvinyl anthracene, polyvinyl pyrene, and the like. Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinylpyridine, cellulose resin, urethane resin , epoxy resin, casein, polyvinyl alcohol, polyvinylpyrrolidone, and other insulating resins.

'The resin contained in the cargo generating layer is suitably 80% by weight or less, preferably 40% by weight and 9g or less.

Solvents that dissolve these resins vary depending on the type of resin, and are preferably selected from those that do not dissolve the underlying four cargo transport layers and 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 dimethyl sulfoxide. Sulfoxides such as tetrahydrofuran, dioxane, ethers such as ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, aliphatics such as chloroform, methylene chloride, dichloroethylene, 'R carbon chloride, ) IJ chloroethylene, etc. Halogenated hydrocarbons or aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. can be used.

Coating methods include dip coating method, sdale coating method, spinner coating method, bead coating method,
This can be carried out using a coating method such as a Mayer bar coating method, a Fried coach ink 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℃ to 200℃ for 5 minutes or more
It can be carried out stationary or under blown air for a time in the range of 2 hours.

The charge transport layer is electrically connected to the charge generation layer described above, and receives and receives '1 charge carriers injected from the charge generation layer in the presence of a field, and transports these charge carriers to the surface. It has the ability to At this time, this charge transport layer may be laminated on the charge generation layer,
Moreover, it may be laminated thereunder.

'1 When the charge transport layer is formed on the charge generation layer, the substance that transports charge carriers in the charge transport layer (hereinafter simply referred to as charge transport material) is in the wavelength range of electromagnetic waves to which the charge generation layer is sensitive. The reason why it is preferable that the charge transport layer is substantially insensitive to is because the charge transport layer has a filter effect and prevents a decrease in sensitivity. Here we say “′
- Electromagnetic waves include the broad definition of "light rays" including r-rays, X-rays, ultraviolet rays, visible light, near-infrared rays, infrared rays, far-infrared rays, and the like.

Charge transporting substances include electron transporting substances and hole transporting substances, and electron transporting substances include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4.7-dolinitro-9-fluorenone,
2,4,5.7-tetranitro-9-fluorenone, 2
．． 4.7-dolinitro9-dicyanomethylenefluorenone, 2,4.5.7-tetranitroxanthone,2.
Examples include electron-withdrawing substances such as 4.8-trinidrothioxanthone and polymerized materials of these electron-withdrawing substances.

Examples of hole-transporting substances include pyrene, N-ethylcarbazole, N-ingrovircarbazole, and N-mef-N.
-Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ethyl, rufenotiazine, N,N-diphenylhydrazino-3=methylidene-10-ditylphenoxazine, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone, P-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, P- Pyrrolidinobenzaldehyde-N,N-diphenylhydrazone, 1.3.
3-trimethylindolenine-ω-aldehyde-N,N
- Hydrazones such as diphenylhydrazone, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, 2,5-bis(P-diethylaminophenyl) -1,3,4-oxadiazole, 1-phenyl -3-(P-diethylaminostyryl)-5-(P
-diethylaminophenyl)pyrazoline, 1-[quinolyl(2) ] -3-(P-diethylaminostyryl)
-5-(P-diethylaminophenyl)pyrazoline, 1
-[Pyridyl(2)) -3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, 1-[:6-methoxy-pyridyl(2)]
-3-(P-diethylaminostyryl) -5-(P
-diethylaminophenyl)pyrazoline, 1-[pyridyl(3)) -3-(P-diethylaminostyryl) -5-(P-diethylaminophenyl)pyrazoline, 1-C lepidyl(2)] -3-(P-diethylaminostyryl) )-5-(P-diethylaminophenyl)hilazoline, 1-[pyridyl(2) 'J -3-(
P-diethylaminostyryl)-4-methyl-5-(P
-diethylaminophenyl)pyrazoline, 1-[pyridyl(2)] -3-(α-methyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)hirazoline, 1-phenyl-3-(P-diethylaminostyryl) Pyrazolines such as -4-methyl-5-(P-diethylaminophenyl)pyrazoline, 1-phenyl-3-(α-pe/zi-P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, spiropyrazoline, 2 -(P-diethylaminostyryl)
-6-dietheraminobenzoquinasol, 2-(P-
oxazole compounds such as diethylaminophenyl)-4-(P-dimethylaminophenyl)-5-(2-chlorophenyl)oxazole, thiazole compounds such as 2-(P-diethylaminostyryl)-6-dinithylaminobenzothiazole , bis(4-diethylamino-2
-methylphenyl)-phenylmethane, 1,1-bis(4-N,N-diethylamine-2-methylphenyl)hebutane, 1,1,2.
Polyarylalkane such as 2-f-5kis(4-N,N-dimethylamino-2-methylphenyl)ethane, triphenylamine, stilbene derivative J-N,
-Vinylcarbasol, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, ethylcarbazole formaldehyde resin, and the like.

In addition to these organic transport materials, inorganic materials such as selenium, selenium-tellurium amorphous silicon, and cadmium sulfide can also be used.

Further, these charge transport substances can be used alone or in combination of two or more.

When the charge transport material does not have film-forming properties, a film can be formed by selecting an appropriate binder. Examples of resins that can be used as binders include acrylic resin,
Insulating resins such as polyarylate, polyester, polycarbonate, polystyrene acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber, or poly-N-vinylcarbasol, Mention may be made of organic photoconductive polymers such as polyvinylanthracene and polyvinylpyrene.

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 5 microns to 30 microns, with a preferred range of 8 microns to 20 microns. When forming the charge transport layer by coating, an appropriate coating method as described above can be used.

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 the substrate having a conductive layer include those whose substrate itself is conductive, such as aluminum, aluminum alloy, copper, zinc,
Stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, platinum, etc. can be used, and in addition, aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. can be coated by vacuum evaporation method. Plastics with formed layers (e.g. polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluoroethylene, etc.), conductive particles (e.g.
A substrate made of plastic coated with carbon black, 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 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 0.1 micron to 5 micron, preferably 0.5 micron to 3 micron.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, and the charge transport material is an electron transport material, the surface of the charge transport layer must be positively charged, and exposure after charging is required. Then, in the exposed area, electrons generated in the charge generation layer are injected into the charge transport layer, and then reach the surface and neutralize the positive charge, causing a decrease in surface potential and creating an electrostatic contrast with the unexposed area. .

A visible image can be obtained by developing the electrostatic latent image thus formed with a negatively charged toner. Either fix this directly, or transfer the toner image to paper or plastic film, etc.
It can be established.

Alternatively, a method may be used in which the electrostatic latent image on the photoreceptor is transferred onto an insulating layer of transfer paper, and then visually imaged and fixed. The type of developer, the developing method, and the fixing method may be any known ones or known methods, and are not limited to specific ones.

On the other hand, when the charge transport material consists of a hole transport material, the surface of the charge transport layer must be negatively charged, and when exposed to light after charging, holes generated in the charge generation layer are injected into the charge transport layer in the exposed area. .

After that, it reaches the surface and neutralizes the negative charge, causing a decrease in surface potential and creating an electrostatic contrast with 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.

Another specific example of the present invention is an electrophotographic photoreceptor containing the above-mentioned organic photoconductor together with a charge transport material in the same layer. In this case, in addition to the charge transporting substance described above, a charge transfer complex compound consisting of poIJ-N-pynylated rubazole trinitrofluorenone can be used.

The single-child photographic photoreceptor of this example can be prepared by dispersing the above-mentioned organic photoconductor and charge transfer complex compound in a polyester solution dissolved in tetrahydrofuran, and then forming a film thereon.

In any of the photoreceptors, the pigment used is of the general formula (1)
For purposes such as obtaining a panchromatic photoreceptor containing at least one type of pigment selected from the disazo pigments shown in the following, and increasing the sensitivity of the photoreceptor using a combination of pigments with different light absorptions as necessary. It is also possible to use a combination of two or more types of disazo pigments represented by the general formula (1), or a combination with a charge generating substance selected from known dyes and pigments.

The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in a wide range of electrophotographic applications such as laser printers and C-T printers.

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

Example 1 Ammonia aqueous solution of casein (casein 1
1.2SF, 28% ammonia water l? , water 222m/?
) was applied with a Mayer bar so that the film thickness after drying was 1.0 micron, and dried.

Next, the above-mentioned disazo pigment A(6) 5 F was mixed with butyral resin (butyralization degree 6) in 95 m/ethanol.
3 mol
Spread out time. 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.

hydrazone compound 52 and polymethyl methacrylate resin (number average molecular weight 100,000) 57 were mixed with benzene 70
ml, and applied onto the charge generation layer using a Mayer bar so that the film thickness after drying would be 12 microns, and dried to form a charge transport layer.

The electrophotographic photoreceptor thus prepared was statically charged with corona using an electrostatic copying paper tester Model 5F-428 manufactured by Kawaguchi Denki ■, and charged to about -600V and held in a dark place for 1 second. It was exposed to light at an illuminance of 2.2 ux and the charging characteristics were examined.

As for the charging characteristics, the surface potential (Vo) and the exposure amount (E%) required to attenuate the potential to % when dark decayed for 1 second were 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 5t! ux-se
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 4. This copying machine is configured to produce an image on transfer paper as a cylinder is driven.

Using this copying machine, the initial bright area potential (ML) and dark area potential (VD) and the bright area potential (Vt) and dark area potential (Vo) after 5000 uses were measured.

The results are shown in Table 2.

Table 1 Vo: e610 Volt E%: 2°Ol! uxeSeC Table 2 1 e640 volt e20 volt e660 port e50 volt (The unit in the table is volt) Examples 2 to 32 In place of the disazo pigment used in Example 1, the disazo pigment shown in Table 3 was used. An electrophotographic photoreceptor was produced in the same manner as in Example 1 except for the following.

The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1. These results are shown in Table 4.

Table 3 Example Disazo Pigment 2 Said Exemplified Disazo Pigment A(1) 3
zI6(z)5
rot (8) 6
/1g(9)7
A6(10)11
, /16(18)12
/l6(19)13
A(20)14/Vi(21) 15 A(25)17
/l6(27)18
A(28)19
．． 16(29)ζπ 3
Table (Continued) 20 Disazo pigment as illustrated above/16 (3o)
21 A(31)22
/l6(32)23
/l6(33)24
rot (34) 25
A (35)26
Demon (37) 28
rot (39) 29
Demon (40) 31
/l6(42)Wj 4 Table (Bot υ) (Bolt) (Bolt) (Bolt) 2 6
00 2.4 640 30 66
0 703 590 2.7 6
30 40 670 804 60
0 2.5 620 30 640
705 610 2.3 620
20 640 506 590
2.8 610 30 590
607 600 1.8 630
20 620 608 600 2
．． 4 610 30 630 509
610 2.6 620 30
640 7010 590 2.8
640 40 6.70 7011
600 2.5 610 30
630 6012 610 2.3
610 30 620 7013 59
0 2.3 620 30 640
6014 600 2.4 630
40 650 7015 600
1.8 620 20 640
6 (1166102,063020670501759
02,164020660504F, 4 Table
(Continued) (Bolt) (Bolt) (Bolt) (Bolt) 18 6
10 2.2 610 30 64
0 6019 610 2.5 6
10 50 650 8020 600
1.9 640 20 660
6021 590 1.8 630
20 670 5022 600
2.0 620 20 650
6023 610 2.6 640
30 640 70245902.3
630 20 600 6025 59
0 2.7 620 40 64
0 8026 580 1.8 6
10 20 630 6027 610
2.0 630 30 660
6028 600 1.9 62
0 20 640 5029 610
2.1 620 30 650
6030 570 1.7 600
20 620 5031 590
1.8 610 20 630
6032 600 2.2 630
30 660 70 (In the table, all IM and place signs are e.) Comparative Examples 1 to 4 In place of the disazo pigment Taka (1) used in Example 2, the following comparative pigments A to D were used, respectively. Except there was.

A comparative photoreceptor was prepared in exactly the same manner and its photosensitive characteristics were measured. The results are shown in Table 5.

Table 5 1 600 3.6 620 50
680 1402 610 3.5
600 50 660 130.3 610
4.1 630 60 690
1504 600 3.6 620
50 670 130 From the characteristics shown in Table 5, the photoreceptor of the main invention was superior in sensitivity to the photoreceptor of the comparative example, and the VD and vL stability after durability were extremely good, confirming the effects of the present invention.

Example 33 On the charge generating layer prepared in Example 1, 2,4°7-dolinitro-9-fluorenone 52 and poly-4,4'-dioxydiphenyl-2,2'-propane carbonate (
A coating solution prepared by dissolving 5S' (molecular weight: 300,000) in 70 ml of tetrahydrofuran was applied so that the coating weight after drying was 10 f/ze, and dried.

The electrostatic charge of the electrophotographic photoreceptor thus prepared was measured in the same manner as in Example 1. At this time, the charge polarity is ■ and [7
Ta. The results are shown in Table 6.

46 Table vo, ■590 Port By6: 4,3 eux-sec Initial dark area '1st ■D: ■600 volt initial bright area potential vL: ■ Dark area potential after 5000 cycles of 60 volt vD 2 e630 volt Example 34 Aluminum A polyvinyl alcohol film having a thickness of 1.1 microns was formed on the aluminum surface of the vapor-deposited polyethylene terephthalate film.

Next, the dispersion of the disazo pigment used in Example 1 was applied onto the previously formed polyvinyl alcohol layer using a Mayer bar so that the film thickness after drying would be 0.5 microns, dried and charged. A generation layer was formed.

Next, the pyrazoline compound of structural formula 5? A liquid obtained by dissolving polyarylate resin (condensation polymer of bisphenol A and terephthalic acid-isophthalic acid) 52 in 70 ml of tetrahydrofuran was placed on the charge generation layer with a gold layer so that the film thickness after drying was 10 microns. The mixture was dried to form a charge transport layer.

The charging characteristics and durability characteristics of the photoreceptor thus prepared were measured in the same manner as in Example 1. This result is the seventh
Shown in the table.

Table 7 VO: 9610 volts E%: 2,3 eux-sec initial potential V
o: e610 volt initial bright area potential VL:
e Dark f% ilt vD after 5000 cycles of 20 volts: e 640 volts Example 3
5. An ammonia aqueous solution of casein was applied onto an aluminum plate with a thickness of 100 microns and dried to form a subbing layer with a thickness of 1.1 microns.

Then, 2.4.7-) dinitro-9-fluorenone 5
t and BoIJ-N-vinylcarbasol (number average molecule 83
00.000 ) 5 f Tetrahydro 7 run 70ml
to form a charge transfer complex. This charge transfer complex compound and the exemplified disazo pigment A (26) IP,
Polyester resin (Pylon: manufactured by Toyobo Co., Ltd.) 5F was added to a solution in which 70 mj K of tetrahydro 7 run was dissolved and dispersed. This dispersion was applied onto the undercoat layer so that the film thickness after drying was 12 microns, and dried.

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 8. However, the charging polarity was set as ■.

Table 8 vO: Φ600 Volt E%: 4,8 gux-sec Example 36 The charge transport layer and charge generation layer of Example 1 were placed on the casein layer of the aluminum substrate provided with the casein layer used in Example 1. A photoreceptor was formed in exactly the same manner as in Example 1, except that the photoreceptors were sequentially laminated and the layer structure was different, and charging was measured in the same manner as in Example 1. However, the charging polarity was set to ■.

Charging characteristics are shown in Table 9.

Table 9 110: ■600v

Claims (1)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (1) (In the formula, R_1, R_2, and R_3 represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, or a cyano group. , R_1, R_2, and R_3 represent an alkyl group, an alkoxy group, a halogen atom, or a cyano group. A represents a coupler residue having a phenolic hydroxy group.) (2) General formula (1) ) in which A is the following general formula (2)
The electrophotographic photoreceptor according to claim 1, which is represented by (6). General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (2) (In the formula, X represents a residue necessary to form a polycyclic aromatic ring or a heterocycle by condensing with a benzene ring.R
_4 and R_5 each represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group that may each have a substituent, and R_4 and R_5 are residues that form a cyclic amino group bonded with a nitrogen atom shows. ) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (3) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (4) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (5) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (6) (In the formula, R_6 and R_7 each represent an optionally substituted alkyl group, aralkyl group, or aryl group. Y represents a divalent hydrocarbon group.) (3) General formula (1)
The electrophotographic photoreceptor according to claim 1, wherein the disazo pigment represented by the formula (7) is a disazo pigment represented by the following general formula (7). General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (7) (In the formula, R_1, R_2 and R_3 represent a hydrogen atom or a chlorine atom, and at least one of R_1, R_2 and R_3 represents a chlorine atom. R_8 represents a hydrogen atom or a halogen atom.) (4) The photosensitive layer has a charge generation layer and a charge transport layer, and the charge generation layer contains a disazo pigment represented by the general formula (1). An electrophotographic photoreceptor according to claim 1. (5) Claim 3, wherein the photosensitive layer has a charge generation layer and a charge transport layer, and the charge generation layer contains a disazo pigment represented by the general formula (7). electrophotographic photoreceptor.