JPH01229261A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having high sensitivity and superior durability causing only small change of light part potential and dark part potential during formation of a continuous picture image due to repetitive charge and exposure by incorporating a specified compd. into a photosensitive layer. CONSTITUTION:A photosensitive layer incorporated with a compd. expressed by formula I is formed on an electroconductive base body. In formula I, Ar is an aryl group such as phenyl, naphthyl, anthranyl group, etc.; each R1 and R2 is an alkyl group such as methyl, ethyl, propyl group, etc., aralkyl group such as benzyl, phenethyl, naphthylmethyl, etc., aromatic group such as phenyl, naphthyl, etc., or heterocyclic group such as piperidyl, pyrrolyl, pyrrolidinyl, quinolyl, thienyl, etc. Thus, a photosensitive body having high sensitivity and superior durability and causing scarce change of the light part potential and dark part potential, is obtd.

Description

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

[Prior Art] Conventionally, patented organic photoconductive polymers featuring polyvinylcarbazole have been proposed as photoconductive materials for use in electrophotographic photoreceptors, but these polymers have poor performance compared to inorganic photoconductive materials. Although it has excellent film formability and light weight, it has been difficult to put it into practical use to date because sufficient film formability has not yet been obtained, and sensitivity and durability have not yet been achieved. This is because they are inferior to inorganic photoconductive materials in terms of stability against environmental changes.

In addition, hydrazone compounds described in U.S. Pat. No. 4,150,987, triarylpyrazoline compounds as described in U.S. Pat.
Low-molecular organic photoconductors such as 9-styrylanthracene compounds described in JP-A-828 and JP-A-51-94829 have been proposed.

By appropriately selecting the binder used, such low-molecular-weight organic photoconductors can overcome the drawbacks of film-forming properties that had been a problem in the field of organic photoconductive polymers. It cannot be said that the sensitivity is sufficient.

For 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. 38,378.
No. 51, US Pat. No. 3,871,882, and the like.

Also, JP-A-58-199352, JP-A-61-
245165, JP-A No. 62-964, etc., hydrazone compounds having a substituted amine group at the para position are described as charge transport substances.

However, electrophotographic photoreceptors that use conventional low-molecular organic photoconductors in the charge transport layer do not necessarily have sufficient sensitivity and characteristics, and also have problems when repeatedly charged and exposed after strong-motion light irradiation. However, there is a point that needs to be improved significantly, such as fluctuations in the bright and dark potentials.

[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 to provide a charge generation layer and a charge transport layer. The object of the present invention is to provide a novel charge transport material in a laminated photosensitive layer with functionally separated functions.

[Means for Solving the Problems, Effects] The present invention is an electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive support, characterized in that the photosensitive layer contains a compound represented by the following general formula (1). Consists of an electrophotographic photoreceptor.

In the formula, Ar represents an aryl group having a substituted amino group at least at the ortho position, and R1 and R2 are the same or different and are an alkyl group that may have a substituent or an aralkyl group that may have a substituent. , represents an aromatic ring group which may have a substituent or a heterocyclic group which may have a substituent.

Specifically, the aryl group includes phenyl, naphthyl, anthranyl, etc., the alkyl group includes methyl, ethyl, propyl, etc., the aralkyl group includes benzyl, phenethyl, naphthylmethyl, etc., and the aromatic ring group includes groups such as benzyl, phenethyl, and naphthylmethyl. is a group such as phenyl or naphthyl; examples of the heterocyclic group include groups such as piperidyl, pyrrolyl, pyrrolidine, quinolyl, and thienyl; substituents for the above groups include alkyl groups such as methyl, ethyl, and propyl, methoxy,
Examples include alkoxy groups such as ethoxy and propoxy, halogen atoms such as fluorine, chlorine and bromine atoms, and substituted amino groups such as dimethylamino and diphenylamine 7.

Furthermore, the present invention is characterized in that Ar in the compound represented by the general formula (I) is a compound represented by the following general formula (II).

/ In the formula, R3 and R4 are the same or different and are an alkyl group such as methyl, ethyl, and propyl that may have a substituent, and an aralkyl group such as benzyl, phenethyl, and naphthylmethyl that may have a substituent. , indicates an aromatic ring group such as phenyl or naphthyl which may have a substituent, or a heterocyclic group such as quinolyl or thienyl which may have a substituent,
Alternatively, R3 and R4 may form a ring together with a nitrogen atom, and R5 and R6 are the same or different, and are hydrogen atoms,
Alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, ethoxy, and propoxy, halogen atoms such as fluorine, chlorine, and bromine, nitro, cyan, or substituted amine groups represented by the following general formula (m) shows.

Examples of the substituents in R3 and R4 include alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, ethoxy, and propoxy, fluorine atoms, chlorine atoms, bromine atoms, etc. and substituted amino groups such as dimethylamino and diphenylamino.

The electrophotographic photoreceptor of the present invention has R1 in general formula (I)
When R2 and R2 are both aromatic ring groups, an electrophotographic photoreceptor with particularly excellent characteristics such as sensitivity can be provided as compared to other cases.

The reason why the electrophotographic photoreceptor of the present invention exhibits good characteristics is not clear, but it is presumed that the main reason is that photoisomerization is less likely to occur due to the presence of a substituted amine group at the ortho position.

Representative examples of the compound represented by general formula (I) are listed below.

Exemplified Compound (1) Exemplified Compound (2) Exemplified Compound (3) Exemplified Compound (4) CzHr
qHz Exemplary Compound (5) Exemplary Compound (6) Exemplary Compound (9) Exemplary Compound (10)
Exemplified Compound (11) Exemplified Compound (12) Exemplified Compound (13) Exemplified Compound (14) Exemplified Compound (15)
) Exemplary compound (16) Exemplary compound (17)
Exemplified Compound (18) Exemplified Compound (19) Exemplified Compound (20) Exemplified Compound (21) Exemplified Compound (22)
) Exemplified Compound (23) Exemplified Compound (24) Exemplified Compound (25) Exemplified Compound (26) Exemplified Compound (2)
7) Exemplary compound (28) Exemplary compound (29)
Exemplified Compound (30) Exemplified Compound (31) Exemplified Compound (32) Exemplified Compound (33) Exemplified Compound (3)
4) Exemplified Compound (35) Exemplified Compound (36) Exemplified Compound (37) Exemplified Compound (38) Exemplified Compound (
39) Exemplary compound (40) Exemplary compound (41)
Exemplified Compound (42) Exemplified Compound (43) Exemplified Compound (44) Exemplified Compound (45) Exemplified Compound (
46) Exemplary compound (47) Exemplary compound (48) Exemplary compound (49) Exemplary compound (50) Exemplary compound (51) Exemplary compound (52) Exemplary compound (53)
) Exemplary compound (54) Exemplary compound (55)
Exemplified Compound (56) Exemplified Compound (57) Exemplified Compound (58) CχHr CyuH5 Exemplified Compound (59) Exemplified Compound (60) Exemplified Compound (61) Exemplified Compound (62) Exemplified Compound (63)
Exemplified Compound (64) Exemplified Compound (65) Exemplified Compound (66) Exemplified Compound (67) Exemplified Compound (68) Exemplified Compound (69) Exemplified Compound (70)
Exemplified Compound (71) Exemplified Compound (72) Exemplified Compound (73) Exemplified Compound (74) Exemplified Compound (75)
) IHy 22.8 g (104 mmol) of the compound (2) above was dissolved in 120 m glacial acetic acid in a 500 m beaker, and 7.9 g (114 mmol) of sodium nitrite was added to this.
A 12mM solution of 12mM in water was added.

After stirring at room temperature for 1 hour, 120mM of methanol was added and 2
23.8 g (364 mmol) of zinc powder was gradually added at below 5°C. After the heat generation stopped, stir at room temperature for 30 minutes,
The precipitate was filtered off.

A solution prepared by dissolving 25.0 g (83 mmol) of the compound (1) above in 70 mJL of glacial acetic acid was added to the filtrate. The precipitated crystals were dispersed and washed with heated methanol, recrystallized using a mixed solvent of methyl ethyl ketone and methanol, purified using a toluene-alumina column, and dried to obtain the target compound.

Yield 28.0g Yield 65.2% Elemental analysis Calculated value (%) Actual value (%) C85,
8585,81 H6,045,99 N 8.11 8.07 Compounds other than those synthesized above are generally synthesized by the same method.

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

The blending ratio of the binder and the charge transport material is 10% of the binder
Preferably, the amount of the charge transport compound 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 has the function of receiving and taking charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. have. At this time, this charge transport layer may be laminated on the charge generation layer or may be laminated under the charge generation layer. but,
It is desirable that the charge transport layer is laminated on the charge generation layer.

This charge transport layer cannot be made thicker than necessary because there is a limit to its ability to transport charge carriers. −・
5-40 micron for boat fishing, preferred range is 10-30
It is micron.

The organic solvent used in forming this 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 subbing layer. Specific organic solvents include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, methyl imbutyl ketone, and dichlorohexanone, N, N-dimethylformamide, N, N-dimethylacetamide, etc. amides, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, chloroform, methylene chloride,
Aliphatic halogenated hydrocarbons such as dichloroethylene, carbon tetrachloride, trichlorethylene, etc., or aromatics such as benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, etc. can be used.

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.

For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying can be carried out at a temperature of 30 to 200'O for 5 minutes to 2 hours, either stationary or with ventilation.

The charge transport layer in the present invention can contain various additives. For example, plasticizers such as diphenyl, m-terphenyl, dibutyl phthalate, silicone oil, grafted silicone polymers, surface lubricants such as various fluorocarbons, potential stabilizers such as dicyanovinyl compounds, carbazole derivatives, β-carotene, Ni
Complexes, 1,4-diazabicyclo[2,2,2] octane, and other antioxidants may be mentioned.

The charge generation layer used in the present invention includes an inorganic charge generation material such as selenium, selenium-tellurium, and amorphous silicon;
Cationic dyes such as pyrylium dyes, thiapyrylium dyes, azulenium dyes, thiacyanine dyes, quinocyanine dyes, scuparilium salt dyes, phthalocyanine pigments, anthorone pigments, dibenzpyrenequinone pigments, pyranthrone pigments, etc. Materials selected from organic charge-generating substances such as polycyclic bovine non-pigments, indigo pigments, quinacridone pigments, and azo pigments can be used alone or in combination for the vapor deposited layer or coating layer.

Among the charge-generating substances used in the present invention, there are a wide variety of azo pigments in particular, and typical structural examples of particularly effective azo pigments are shown below.

The general formula of the azo pigment is as shown below, where the central skeleton is A, the coupler portion is cp, and n=2 or 3.
Specific example of A-(N=N-Op)nA, methoxy group) (R is hydrogen atom, cyan group), X is oxygen atom, sulfur atom) group, chlorine atom, X is oxygen atom, sulfur atom) is Hydrogen atom, methyl group, phenyl group) (or oxygen atom, sulfur atom) (X is oxygen atom, sulfur atom) A-1,I R (R is hydrogen atom, methyl group) -CΣ'';L(Lee (X (X is an oxygen atom, a sulfur atom) (X is an oxygen atom, a sulfur atom) zHs -CH= N -N = c H-@-thyl group) Specific examples of Cp p-1 Group, nitro group, etc., n is an integer of 1 or 2) p-2 group, alkyl group, nitro group, etc.) p-4 p-5 0H (R is an alkyl group, aryl group, etc.) p-7 n is an integer of 1 or 2) etc. Can be mentioned.

By combining these central skeleton A and coupler CP as needed, an azo pigment serving as a charge-generating substance is formed.

The charge-generating layer can be formed by dispersing the above-mentioned charge-generating substance in a suitable binder and coating it on a support, or it can be formed by forming a vapor-deposited film using a vacuum evaporation device. .

The binder can be selected from a wide range of insulating resins and organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. Preferably polyvinyl butyral, polyaryl 1- (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, urethane resin, Examples include insulating resins such as casein, polyvinyl alcohol, and polyvinylpyrrolidone. Resin contained in the charge generation layer is 80% by weight
Below, preferably 40% by weight or less is suitable.

Organic solvents used during coating include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and amides such as N,N-dimethylformamide and N,N-dimethylacetamide. , sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, and ethylene glycol methyl ether, esters such as methyl acetate and ethyl acetate, and fats such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene. Group halogenated hydrocarbons or aromatics such as benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, etc. can be used.

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 said organic photoconductor as possible in order to obtain sufficient absorbance and in order to inject charge carriers into the charge transport layer within the lifetime of the generated charge carriers, a thin film layer, e.g. 5 microns or less, preferably 0.
A thin film layer having a thickness of 0.01 to 1 micron is preferable. 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 must be injected into the charge transport layer without being deactivated by recombination or trapping. It is caused by something.

The photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer.
Provided on a support having a conductive layer.

As the support having a conductive layer, the support itself has conductivity, for example, aluminum, aluminum alloy, copper,
Zinc, stainless steel, vanadium, molybdenum, chromium,
Titanium, nickel, indium, gold, platinum, etc. can be used, and plastics ( For example, polyethylene, polypropylene,
conductive particles (e.g. aluminum powder, titanium oxide, tin oxide, zinc oxide,
Supports such as carbon black, silver particles, etc.) coated on plastic or the above-mentioned conductive support with a suitable binder, supports made of plastic or paper impregnated with conductive particles, and plastics containing conductive polymers. Can be used.

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

The subbing layer is formed from casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide, (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc. can.

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

When using a photoreceptor in which a conductive support, a charge generation layer, and a charge transport layer are laminated in this order, the charge transport material of the present invention has hole transport properties, so it is necessary to negatively charge the surface of the charge transport layer. When exposed to light after charging, 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, causing a decrease in surface potential and a gap between the exposed area and the unexposed area. Electrostatic contrast occurs. It is necessary to use positively charged toner during development.

In another embodiment of the present invention, the azo pigments described above or those described in U.S. Pat.
No. 3,586,500, etc., photoconductive pigments and dyes such as pyrylium dyes, thiapyrylium dyes, selenapyrylium dyes, benzopyrylium dyes, benzothiapyryllium dyes, and naphtopyrylium dyes are used. It can also be used as a sensitizer.

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

This eutectic complex combines, for example, 4-[4-bis-(2-chloroethyl)aminophenyl]-2,6-diphenylthiapyrylium verchlorate and poly(4,4'-isopropylidene diphenylene carbonate) with a halogen. Hydrocarbon solvents (e.g. dichloromethane, chloroform, carbon tetrachloride, 1.1-dichloroethane, 1,2-dichloroethane, 1.1.2-trichloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene) After dissolving, it is obtained as a particulate eutectic complex by adding a non-polar solvent (eg hexane, octane, decane, 2,2,4-trimethylbenzene, ligroin).

The electrophotographic photoreceptor in this specific example includes styrene-butadiene copolymer, silicone resin, vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, polymethyl methacrylate, poly- N-butyl methacrylate,
Polyesters, cellulose esters, 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.

The electrophotographic photoreceptor of the present invention has the advantage of high sensitivity and small fluctuations in bright area potential and dark area potential when repeatedly charged and exposed.

[Examples] Example 1 5 g of a disazo pigment represented by the following structural formula was dispersed in a sand mill for 24 hours with a solution of 2 g of butyral resin (degree of butyralization: 63 mol %) dissolved in 100 ml of cyclohexanone to prepare a coating solution.

This coating solution was applied onto an aluminum sheet using a Meyer bar to a dry film thickness of 0.2 microns to form a charge generation layer.

Next, Log of exemplary compound (54) as a charge transport material and 10 g of polycarbonate (average molecular weight 20,000) were dissolved in 70 g of monochlorobenzene, and this solution was applied onto the previously formed charge generation layer using a Mayer bar and dried. A charge transport layer having a thickness of 20 microns was formed to produce an electrophotographic photoreceptor.

This electrophotographic photoreceptor was statically charged with corona at 15 KV using an electrostatic copying paper testing device Model 5P-428 manufactured by Kawaguchi Denki ■, held in a dark place for 1 second, and then charged with an illuminance of 20 uux. 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 (vl) to 1/2 when dark decayed for 1 second were measured.

Furthermore, in order to measure the deterioration of the photoreceptor due to light irradiation, only a portion of the photoreceptor prepared on the wood flow side was exposed to an illuminance of 1. , 5
After exposing for 5 minutes at 00mm ux, hold in the dark for 5 minutes,
It was attached to the photosensitive drum cylinder of a PPC copying machine NP-3525 manufactured by Canon ■. 5,000 sheets were copied using the same machine, and changes in bright area potential difference (ΔVL) and dark area potential difference (ΔVD) between the strong exposure history area and the non-history area were measured at the initial stage and after 5,000 copies were made.

Note that the dark potential and bright potential of the initial non-history part are −
The voltages were set to 700V and -200V. The results will be described later.

For comparison, a similar photoreceptor was prepared using a compound (A) represented by the following structural formula in place of the above-mentioned exemplified compound as a charge transport material, and measurements were conducted in the same manner. Show the results.

Example 1 703 691 3.1 Comparative example 1 6
99 686 3.4 Example i +io
=! =0 Comparative Example 1 -130 -30 Example 1 +10 +20 Comparative Example 1
+50 +120As is clear from the above,
It can be seen that the electrophotographic photoreceptor of the present invention has good sensitivity and has little potential fluctuation in areas with strong exposure history. , Examples 2 to 15 In each of these Examples, exemplified compounds (1), (2), (3), (4),
(5), (6), (7), (8), (9), (16),
(18), (19), (47), and (63) and a pigment having the following structural formula as a charge generating substance, but otherwise an electrophotographic photoreceptor was prepared in the same manner as in Example 1.

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

2 704691 2.1 3 700689 1.8 4 698 688 2.4 5 705 693 2.56
699 690 2.2 7 698 689 2.0 8 701 685 2.19
701 689 1.910 6
96 682 2.8 11 702 692 2.6 12 696 680 3.213
707 695 3.214
692 680 2.215
704 689 2.72
+10 ± 03
-20 +204
-10 +105
± 0 +106 -10
+107 +10
+208 -10
±09 -10
+2010 ± 0
+1011 +10
=l=012 ± O
+2013 +10
± 014 ± 0
+1015 +10
+102 +lO
+203 +10 +2
04 +20 +205
+20 +206
+10 +107
+20 +208
+10=l=09
+10 +2010
+10 +2011
+20 +20i2
+10 +2013
+10 +1014
+10 +2015
+20 +20 Example 16 An ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 22.2 m of water) was applied onto an aluminum cylinder using a blade coating method to form a subbing layer with a dry film thickness of 1 micron. did.

Next, a charge generating substance Log represented by the following structural formula, 5 g of a butyral resin (butyralization degree: 63 mol %), and 200 g of cyclohexanone were dispersed for 48 hours using a ball mill disperser. This dispersion was applied onto the previous subbing layer by a blade coating method to form a charge generation layer with a dry film thickness of 0.15 microns.

Next, 10 g of Exemplified Compound (1), 10 g of polymethyl methacrylate (average molecular weight 50,000), and 7 g of monochlorobenzene were added.
The solution was dissolved in 0 g and coated on the previously formed charge generation layer by a blade coating method to form a charge transport layer with a dry film thickness of 19 microns.

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 1 second.

Sensitivity is the exposure amount (E 1/2 #LJ/cm
2) was evaluated by measuring.

At this time, the light source was a gallium/aluminum/propylene ternary semiconductor laser (output 5 mW, oscillation wavelength 780 nm).
) was used. Show the results.

VONY 703V Vl VONY 690V El/2: 2. OpJ/cm2 Next, there is a laser beam printer (a reversal development type electrophotographic printer equipped with the same semiconductor laser as above).
A photoreceptor (trade name: LBP-CX, manufactured by Canon ■) was replaced with the photoreceptor of the present invention, and an actual image forming test was conducted under the conditions shown below.

Surface potential knee after primary charging 700 V, surface potential knee after image exposure 150 V (exposure amount 2.0 J/cm2), transfer potential knee z'oov, developer polarity: negative polarity, process speed: 50 mm/s e c. Development conditions (development bias) knee 450V, image exposure scanning method: image scan, - exposure before next charging: red full exposure at 50uX, Sec.

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.

Further, when 3,000 images were printed continuously, stable and good prints were obtained from the initial stage up to 3,000 sheets.

Example 17 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and the exemplified compound (
Add 5 g of 2) to polyester (Polyester Adhesive 49000: manufactured by DuPont) not toluene-dioxane (
50 parts by weight: 50 parts by weight) was mixed with 100 mu of the solution and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet using a Meyer bar so that the film thickness after drying was 15 microns.

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

Vony 704V, Vl knee 685V El/2: 2.8uux, see Initial potential difference ΔvD = +20V, Δvshi: ±OV Potential difference after 5,000 sheets durability ΔvD: +20v, ΔvL=+20v Example 18 4-(4-dimethyl 3 g of aminophenyl)-2,6-cyphenylthiapyrylium perchlorate and poly(4,
4-isopropylidene diphenylene carbonate) 3g
was sufficiently dissolved in 200 ml of dichloromethane, and 100 ml of toluene was added to precipitate a eutectic complex. After filtering this precipitate, dichloromethane was added to redissolve it, and then 100 mL of n-hexane was added to this solution to obtain a precipitate of a eutectic complex.

5 g of this eutectic complex was added to 95 mJlj 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 microns to form a charge generation layer.

Next, a charge transport layer was formed on the charge generation layer in the same manner as in Example 1 except that Exemplified Compound (4) as a charge transport substance 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 700V, Vl knee 690VEl/2:
2.6Jljux, see Initial potential difference ΔvD = + 10v, Δvshi = ±Ov Potential difference after 5,000 sheets durability ΔVD: +20V, VL: +20V Example 19 Ammonia aqueous solution of casein (described above) was applied on an aluminum plate using a Mayer bar. The coating was applied to form a subbing layer with a dry film thickness of 1 micron. Thereon, the charge transport layer and charge generation layer of Example 6 were sequentially laminated, and an electrophotographic photoreceptor was prepared in exactly the same manner as in Example 6 except for the layer structure, and the charging properties were the same as in Example 1. was measured. However, the charging polarity was set to +. Show the results.

VO: +705V, Vl: +690Vel/2:3.
1uux, sec Initial potential difference ΔvD: ±Ov, ΔvL=+10v Potential difference after 5,000 sheets durability ΔvD=+20■, VL:+10V Example 20 Soluble nylon (6-66-610-12
A 5% methanol solution of (quaternary nylon copolymer) was applied to form a subbing layer having a dry thickness of 0.5 microns.

Next, 5 g of a pigment having the following structural formula was dispersed in 95 mM of tetrahydrofuran using a sand mill for 200 hours.

7 Next, a solution prepared by dissolving 5 g of the charge transport substance of Exemplary Compound (7) and 10 g of bisphenol Z type polycarbonate (viscosity average molecular weight 30,000) in 30 mM of monochlorobenzene was added to the dispersion prepared earlier, and the mixture was further dispersed in a sand mill for 2 hours. .

This dispersion was applied onto the previous subbing layer using a Mayer bar so that the film thickness after drying would be 20 microns, and then dried.

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

Vo knee 702V, Vl knee 687Vel/2:
2.9Jjux, see Initial potential difference ΔVD: +10v, ΔvL: +10v Potential difference after 5,000 sheets durability ΔVo: +20V, VL: +10V [Effect of the invention] The electrophotographic photoreceptor containing the specific compound according to the present invention has high sensitivity. Furthermore, during continuous image formation by repeated charging and exposure, fluctuations in bright area potential and chamber potential are small, and the durability is excellent.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) In the formula, Ar represents an aryl group having at least a substituted amino group at the ortho position, and R_1 and R_2 are the same or different and may have a substituent. It represents an alkyl group, an aralkyl group which may have a substituent, an aromatic ring group which may have a substituent, or a heterocyclic group which may have a substituent. 2. The electrophotographic photoreceptor according to claim 1, wherein in the compound represented by the general formula (I), Ar is a compound represented by the following general formula (II). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) In the formula, R_3 and R_4 are the same or different, and are an alkyl group that may have a substituent, an aralkyl group that may have a substituent, or a substituent. represents an aromatic ring group that may have a substituent or a heterocyclic group that may have a substituent, or R_3 and R_4 may form a ring together with a nitrogen atom, and R_5 and R_6 are the same or different Indicates a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a nitro group, a cyano group, or a substituted amino group.