JPH0282258A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity and to suppress variances of potentials in the light and in the dark at the time of repeated cycles of electric charging and exposure by incorporating a specified compound in a photosensitive layer. CONSTITUTION:An electrophotographic sensitive body has on a conductive substrate the photosensitive layer containing one of the compounds represented by formula I in which Ar is an aryl group having at least a substituted amino group at the ortho-position and each of R1-R3 is an optionally substituted alkyl, such aralkyl, such aromatic, or such heterocyclic group, thus permitting high sensitivity to be obtained, variances of the potentials in the light and in the dark at the time of successive uses to be reduced, and durability to be enhanced.

Description

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

[Prior Art] Conventionally, various organic photoconductive polymers including polyvinylcarbazole have been proposed as photoconductive materials for use in electrophotographic photoreceptors, but these polymers have not been used as inorganic photoconductive materials. Although it is superior in terms of film formability and light weight, it has been difficult to put it into practical use until now because sufficient film formability has not yet been obtained, and sensitivity, durability, and This is because they are inferior to inorganic photoconductive materials in terms of stability against environmental changes.

In addition, hydrazone compounds described in US Pat. No. 4,150,987, triarylpyrazoline compounds described in US Pat. No. 3,837,851, etc.,
Low-molecular organic photoconductors such as 9-styrylanthracene compounds described in JP-A-94828 and JP-A-51-94829 have been proposed. These low-molecular-weight organic photoconductors have been able to overcome the film-forming problems that had been a problem in the field of organic photoconductive polymers by appropriately selecting the binder used, but the sensitivity It cannot be said that it is sufficient in this respect.

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

Such an electrophotographic photoreceptor is disclosed in, for example, US Pat. No. 383
It is disclosed in the specification No. 7851, the specification No. 3871882, etc.

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

However, electrophotographic photoreceptors using conventional low-molecular-weight organic photoconductors in the charge transport layer do not necessarily have sufficient sensitivity and electrophotographic properties, and the bright area potential and dark area potential when repeatedly charged and exposed to light are There are points that need to be greatly improved, such as fluctuations in bright area potential and dark area potential when repeated charging and exposure are performed after strong-motion light irradiation.

[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 layers.

[Means for Solving Problems 1 Effect] The present invention provides an electrophotographic photoreceptor in which a photosensitive layer is laminated on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula (I). It is composed of an electrophotographic photoreceptor characterized by having a layer.

In the general formula, Ar represents an aryl group having a substituted amine group at least at the ortho position, and RL, R2 and R3 are an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a substituted Indicates an aromatic ring group which may have a group or a heterocyclic group which may have a substituent.

Specifically, Ar is a 7-aryl group such as phenyl, naphthyl, or anthranyl having at least 7 dimethylamino or diphenylamino-substituted amine groups in the ortho position, and R, R2 and R3 are methyl, ethyl, propyl, etc. alkyl groups such as benzyl, phenethyl, and naphthylmethyl, and aromatic ring groups such as phenyl and naphthyl.

It is a heterocyclic group such as quinolyl and thienyl, and the substituents that the above group may have include methyl, ethyl,
Examples include alkyl groups such as propyl, alkoxy groups such as methoxy, nidoxy, and propoxy, halogen atoms such as fluorine, chlorine, and bromine, and substituted amine groups such as dimethylamino and diphenylamino.

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

General formula % Formula % In the formula, R4 and R5 contain an alkyl group that may have a substituent, an aralkyl group that may have a substituent, an aromatic ring group that may have a substituent, or a substituent. represents an optional heterocyclic group.

Further, R4 and R5 may form a ring together with the nitrogen atom to which they are bonded.

R6 and R7 represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a nitro group, a cyano group, or a substituted amino group.

Specifically, R4 and R5 are an alkyl group such as methyl and ethylpropyl, an aralkyl group such as benzyl, phenethyl, and naphthylmethyl, an aromatic ring group such as phenyl and naphthyl, and a hetero 1225 such as quinolyl and thienyl; Examples of substituents that may be present include alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, ethoxy, and propoxy, halogen atoms such as fluorine, chlorine, and bromine, and substituents such as dimethylamino and diphenylamino. Examples include amide 7 group.

R6 and R7 are represented by a hydrogen atom, an alkyl group such as methyl, ethyl, or propyl, an alkoxy group such as methoxy or ethoxypropoxy, a halogen atom such as fluorine, chlorine, or bromine, a nitro group, a cyano group, or the following general formula (m). Examples include substituted amino groups.

Rri In the formula, R4 and R5 have the same meanings as above.

The electrophotographic photoreceptor of the present invention has R1 in general formula (I)
When R2 and R2 are both aromatic ring groups, the electrophotographic photoreceptor has extremely superior properties, particularly sensitivity, compared to other cases.

Although the reason why the electrophotographic photoreceptor of the present invention exhibits good properties is not clear, the presence of a substituted amine group at the ortho position facilitates photoisomerization.

Furthermore, the basicity of the nitrogen atom of the substituted amine group and the d-orbital effect of the sulfide sulfur atom work synergistically to allow environmental deterioration factors generated inside the copying machine, such as ozone, NOx, and nitric acid, to penetrate into the photoreceptor. It is assumed that a major cause is that the

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

Compound example (1) H3 Compound example (5) H.J. Compound example (2) Compound example (6) H3 Compound example (3) C engineering HR Compound example (7) Compound example (4) Compound example (8) Compound example CHλ Compound example (10) Compound example (l l) Compound example (16) Compound example (1 Compound example (18) Compound example (19) Compound example (1 Compound example (13) Compound example (14) Compound example (15) Compound example (20) H3 Compound example (21) Hs Compound example (23) Hx Ch Compound example (25) Compound example (26) Compound example (27) Compound example (31) Compound example (32) CH.

Medium Hz Compound Example (28) Compound Example (29) Compound Example (30) Compound Example (35) Compound Example (36) Hs Compound Example (37) Compound Example (38) C)Igo Compound Example (39) CH Yu Compound Example (40) Compound Example (41) Compound Example (42) Jx Compound Example (48) Hs Compound Example (49) Compound Example (50) Compound Example (51) Compound Example (43) C to Hs Compound Example C YoH compound example (45) C, Hs compound example (46) CH3 compound example (47) Hz compound example (52) Jr compound example (53) zHs compound example (54) compound example (55) CzHr synthesis example (compound Synthesis of Example (1)) n 27.6 g (104 mmol) of the compound of
Dissolve in 120 m of glacial acetic acid in a 0 m beaker, and add 7.9 g (114 mmol) of sodium nitrite to this.
A solution in 2 ml of water was added. After stirring at room temperature for 1 hour, add 120 mol of methanol and add 2 ml of zinc powder at 25°C or below.
3.8 g (364 mmol) was gradually added. After the exotherm had stopped, the mixture was stirred at room temperature for 30 minutes, the precipitate was separated, and 25.0 g (83 mmol) of the above compound was added to the filtrate for 70 m
A solution of 1 in glacial acetic acid was added.

The precipitated crystals were dispersed and washed with heated methanol, recrystallized using a mixed solvent of methyl ethyl ketone and methanol, purified with a toluene/alumina column, and dried to obtain the target compound.

Yield 24.3g, yield 51.9% Elemental analysis Calculated value (%) Actual value (%) C80,
9680,92 H5,905,85 N 7.45 7.41
Compounds represented by general formula (I) other than those on the synthesis side are generally synthesized by the same method.

In a preferred embodiment of the present invention, the compound represented by the general formula (I) is used as a charge transporting material in an electrophotographic photoreceptor in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer.

The charge transport layer in the present invention is preferably formed by applying a solution of the compound represented by the general formula (I) and a binder dissolved 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, phenolic resin epoxy resin, polyester, alkyd resin, polycarbonate, polyurethane or copolymer, such as styrene-bitadiene copolymer, styrene-acrylonitrile copolymer , styrene-
Examples include maleic acid copolymers. In addition to such insulating polymers, organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene, and polyvinylpyrene can also be used.

The blending ratio of this binder and the specific charge transport substance is:
Preferably, the amount of the charge transport material is 10 to 500 parts by weight per 100 parts by weight of the binder.

The charge transport layer is electrically connected to the charge generation layer below and has the function of receiving charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. ing. In this case, this charge transport layer may be laminated on top of the charge generation layer, or may be laminated below it.However, the charge transport layer may be laminated on the charge generation layer. is desirable.

This charge transport layer cannot be made thicker than necessary because there is a limit to how much it can transport a load carrier at 1rf. - For boat fishing, the thickness is 5 to 40 pm, but the preferred range is 10 to 30 pm. .

The organic solvent used to form such a 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 methanol, ethanol,
Alcohols such as Impropatool, ketones such as acetone, methyl ethyl ketone, cyclohexanone, N
, amides such as N-dimethylformamide, N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, methylene chloride, Aliphatic/-logenated hydrocarbons such as chlorethylene, carbon tetrachloride, trichlorethylene or benzene,
Aromatic compounds such as toluene, xylene, 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 bar coating method, a blade coating method, a roller coach ink method, or a curtain coating method. Drying is preferably carried out by drying to the touch at room temperature, followed by heat drying.For boat fishing, heat drying can be carried out at a temperature of 30 to 200°C for 5 minutes to 2 hours, either stationary or under ventilation. preferable.

The charge transport layer of the present invention may contain various additives, such as plasticizers such as diphenyl, m-terphenyl, and dibutyl phthalate, silicone oil, grafted silicone polymers, and various fluorocarbons. Surface lubricants, dicyanovinyl compounds, potential stabilizers such as carbazole derivatives, β-carotene, nickel complexes, 1,4-diazabicyclo[2,2,2
] Examples include antioxidants such as octane.

The charge generation layer in the present invention includes an inorganic charge generation material such as selenium, selenium-tellurium, amorphous silicone, etc.
Cationic dyes such as biryllium dyes, thiapyrylium dyes, azulenium dyes, thiacyanine dyes, and quinocyanine dyes, squbarium salt dyes, phthalocyanine pigments and anthrone pigments, dibenzpyrenequinone pigments, vilanthrone pigments, etc. Materials selected from charge-generating materials for suppressors such as non-coated pigments, indigo pigments, quinacridone pigments, and azo pigments can be used alone or in combination as a vapor deposited layer or a coating layer.

Among the above-mentioned charge-generating substances, there are a wide variety of azo pigments in particular, and typical structural examples of particularly effective azo pigments will be described below.

The general formula of the azo pigment is as shown below, with the central skeleton being A and the coupler portion being Cp, where n is 2 or 3. Specific examples are given below.

A-+N=N-Cp) n Specific examples of A include (x: oxygen atom, sulfur atom R,, R2: hydrogen atom, methyl group, chlorine atom) (R: hydrogen atom, chlorine atom, methoxy group) (R: hydrogen atom, cyano group) (R1, R2: hydrogen atom, methyl group, chlorine atom, etc., R
3: Hydrogen atom, methyl group.

Rumor ) (R: hydrogen atom, cyano group) (x: oxygen atom, sulfur atom) (x: oxygen atom, sulfur atom R: hydrogen atom, methyl group, chlorine atom) (x: oxygen atom, sulfur atom) (X: (oxygen atom, sulfur atom) R (R: hydrogen atom, methyl group) A-12°C convex (x: ・CH, oxygen atom, sulfur atom)

-SOyu) A-21-@-5 (c temperature (R: hydrogen atom, methyl group) Also, as a specific example of Cp, A-14 (n9wt (x: oxygen atom, sulfur atom) (R : hydrogen atom, halogen atom, alkoxy group, alkyl group, nitro group, etc. nil or 2) (x: oxygen atom.

sulfur atom) (R: methyl group, ethyl group, propyl group, etc.) C: LHs ÷C) l-N-N Jn: alkyl group, aryl group, etc.) (R1, R2: hydrogen atom, halogen atom, alkoxy group,
Examples include an alkyl group, a nitro group, etc. (n: 1 or 2).

The central skeleton A and the coupler Cp form a pigment serving as a charge-generating substance by appropriate combination.

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 by forming a vapor-deposited film using a vacuum evaporator. Can be formed.

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, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol,
Examples include polyvinylpyrrolidone.

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

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 can be performed using a coating method similar to that used in forming the charge transport layer.

The charge generation layer contains as much of the organic photoconductor as possible in order to obtain sufficient absorbance and contains a thin film layer, e.g. 5 JLm or less, preferably 0.01
A thin film layer having a thickness of ~Igm is desirable.

A photosensitive layer having such a laminated structure of a charge generation layer and a charge transport layer is provided on a support having a TL conductive layer.

As the support having a conductive layer, the support itself is conductive, such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, platinum, etc. In addition, plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic) have a layer formed by vacuum deposition of aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. resin, polyfluoroethylene, etc.), conductive particles (e.g. aluminum powder, titanium oxide, tin oxide,
Zinc oxide.

A support in which plastic or the above-mentioned conductive support is coated with carbon black, silver particles, etc.) together with a suitable binder, a support in which plastic or paper is impregnated with conductive particles, a plastic containing a conductive polymer, etc. Can be done.

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 and polyvinyl alcohol.

Nitrocellulose, ethylene-acrylic acid copolymer
Polyamide (nylon 6, nylon 66, nylon 61
0, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc.

The thickness of the subbing layer is 0.1 to 5 gm, preferably 0.5 to 3 gm.
pm is appropriate.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, since the charge transport compound in the present invention has hole transport properties, 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 are injected into the charge transport layer in the exposed area, and then reach the surface to neutralize the negative charge, resulting in attenuation of the surface potential and static electricity between the exposed area and the unexposed area. Electrocontrast occurs.

During development, it is necessary to use positively charged toner.

In another embodiment of the invention, the aforementioned disazo pigments or the disazo pigments described in U.S. Pat.
The photoconductivity of biryllium dyes, thiapyrylium dyes, selenapyrylium dyes, benzobyrylium dyes, benzothiapyryllium dyes, naphthopyryllium dyes, naphthothiapyrylium dyes, etc. disclosed in Specification No. 38, Specification 3586500, etc. 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 U.S. Pat. No. 3,684,502, can be used as a sensitizer. The crystal complex is, for example, 4-[4-bis(2-chloroethyl)aminophenyl]
-2,6-Cyphenylthiapyrylium verchlorate and poly(4,4'-isobropylidene diphenylene carbonate) are mixed in a halogenated hydrocarbon solvent such as dichloromethane, chloroform, carbon tetrachloride, ll-dichloroethane, 1. 2-dichloroethane, 11112- ) I
) chloroethane, chlorobenzene bromobenzene, l,
After dissolving in 2-dichlorobenzene, add a non-polar solvent such as hexane, octane, decane, 2,2.4
- Obtained as a particulate eutectic complex by adding trimethylbenzene, ligroin, etc.

The electrophotographic photoreceptor in this specific example includes a styrene-butadiene copolymer and a silicone resin.

Contains vinyl resin, vinylidene chloride-7crylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer polyvinyl butyral, polymethyl methacrylate, poly-N-butyl methacrylate, polyesters, cellulose esters, etc. as a binder. can do.

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 beam printers, CRT printers, and 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.

[Example] Example 1 5 g of a disazo pigment represented by the following structural formula was mixed with butyral resin (
butyralization degree 63 mol%) 2g cyclohexanone l
A coating solution was prepared by dispersing the solution in a sand mill for 24 hours together with the solution dissolved in ooml.

Apply this coating solution to an aluminum sheet with a dry film thickness of 0°21Lm.
A charge generation layer was formed by coating with a Maya bar so that the charge generation layer was formed.

Next, 10 g of Compound Example (39) and 10 g of polycarbonate (average molecular weight 20,000) as a charge transport substance were dissolved in 70 g of chlorobenzene, and this solution was applied onto the charge generation layer using a Mayer bar to determine the dry film thickness. A charge transport layer having a particle diameter of 20 lumen was formed to prepare an electrophotographic photoreceptor.

The thus prepared electrophotographic photoreceptor was statically charged with corona at 15 KV using an electrostatic copying paper tester Model 5R-428 manufactured by Kawaguchi Electric, held in a dark place for 1 second, and then exposed to light at an illumination intensity of 20 lux. , the charging characteristics were investigated.

As for charging characteristics, the surface potential (Vo) and the exposure amount (E 1/2) required to attenuate the potential (vl) to 172 when dark decayed for 1 second were measured.

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential during repeated use, the electrophotographic photoreceptor prepared in this example was attached to the photosensitive drum cylinder of a Canon PPC copier NP-3525. , 50,000 copies were made using the same machine, and changes in dark area potential (Vo) and light area potential (VL) were measured at the initial stage and after 50,000 copies were made.

Furthermore, in order to measure the deterioration of the photoreceptor due to light irradiation,
Only a portion of the photoconductor created in this example was illuminated with an illuminance of 1.50.
After exposing for 5 minutes at 0 lux, hold in the dark for 5 minutes,
It was attached to the photosensitive drum cylinder of a Canon PPC copier NP-3525, and s, ooo copies were made using the same machine. (ΔvL) and dark potential difference (ΔVD) were measured.

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

For comparison, a similar photoreceptor was prepared using a compound (A) represented by the following structural formula as a charge transporting material, and measurements were conducted in the same manner.

Show the results.

Example 1 Comparative Example 1 Example I Vo -700 VL -200 Comparative Example I VD -700 VL -200 Regarding the strong motion light history part -6873,2 -6843,5 V5 V Examples 2 to 14 In each of these Examples , Compound example used in Example 1 (
39), compound examples (1), (2), (3), (4)
, (5), (6), (7), (8), (9), (13)
, (14), (34), and (48), and a pigment having the following structural formula as a charge generating substance, and the other conditions were the same as in Example 1 to prepare an electrophotographic photoreceptor.

Comparison Example 1 Comparative Example 1 VD +10 VL ±O Vo -130 VL -30 +IO +20 +50 As is clear from the above results, when the charge transport compound specified in the present invention is used, it has good sensitivity. However, it can be seen that the potential fluctuation during durability is also small.

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

2.1 1.9 2.5 2.5 Initial 2.1 1, 9 1, 9 1, 9 2, 9 2, 7 3, 3 2.1 2, 9 Strong motion light history part after 50,000 sheets durability About +10 ± O +10 +10 ± O +10 + 10 +10 ± O +10 +10 +lO + 10 +20 ± 0 +20 + 10 ± O +10 +lO +10 + 20 +10 + 20 ± 0 +20 +10 +20 + 10 +20 +20 +20 +20 +10 +20 + 10 +20 + 20 +20 ± 0 13 ±O+10 +10 +
2014 +10 +10 +2
0 +20 Example 15 An ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% aqueous ammonia, 222 mJU of water) was coated on an aluminum cylinder by a blade coating method to form a subbing layer with a dry film thickness of 1 gm.

Next, 10 g of a charge generating substance represented by the following structural formula, 5 g of butyral resin (degree of butyralization: 63 mol %), and 200 g of cyclohexanone were dispersed for 480 minutes in a ball mill. This dispersion was applied onto the previously formed undercoat layer by a blade coating method to form a charge generation layer having a dry film thickness of 0.15 lm.

Next, compound example (1) is Log, and 10 g of polymethyl methacrylate (average molecular weight 50,000) is added to 70 g of chlorobenzene.
The mixture was dissolved in water and applied onto the previously formed charge generation layer by a blade coating method to form a charge transport layer with a dry thickness of 197 Lm.

A corona discharge of 15 KV was applied to the electrophotographic photoreceptor thus prepared. The surface potential at this time was measured (initial potential Vo), and the surface potential after this photoreceptor was left in a dark place for 1 second was measured.

Sensitivity is the exposure amount (El/2, microjoule/cm
2) was evaluated by measuring.

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

VO knee 700V Vt knee 690Vel/2
: 2.0 micro unit/cm2 Next, a laser beam printer (Canon Auxiliary, L
BP-CX) was set in place of the photoreceptor of LBP-CX, and an actual image forming test was conducted.

The conditions were a surface potential knee of 700 V after negative charging.

Surface potential after image exposure knee 150V (exposure amount 2.0 microjoules/cm2), transfer potential: +700V, developer polarity: negative polarity, process speed: 50mm/sec,
Development conditions (development bias) Knee 450V, image exposure scanning method: image scan, - exposure before next charging = 50 u
One image was formed by red full exposure of x, sec by line scanning with a laser beam in accordance with character signals and image signals, and good prints were obtained for each character and image. Furthermore, when 30,000 images were printed continuously, stable and good prints were obtained from the initial stage up to 30,000 sheets.

Example 16 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiavirylium verchlorate and compound example (
Add 5g of 2) to toluene (50 parts by weight) of polyester (Polyester Adhesive 49000, manufactured by DuPont).
- Dioxane (50 fi parts) was mixed with 100 ml of solution and dispersed in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet using a Mayer bar so that the film thickness after dry explosion was 157 zm.

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

vo Knee 705V Vl Knee 685VEl
/2: 2.71ux, sec Class-Image V□ Knee 700V VL Knee 200Vi and Kuyuki Katsuyuki Vo Knee 670V VL Knee 245V About the strong exposure history part? L] Δ■D kneelOv ΔvL=±0v 11Nikyoshi ΔvD:+20v ΔvL=+20v Example 17 3 g of 4-(4-dimethylaminophenyl)-2,6-siphenylthiapyrylium perchlorate and poly( 4,
4”-isobropylidene diphenylene carbonate) 3
g in 200ml of dichloromethane, then 100ml of toluene! L was added to precipitate the eutectic complex. After filtering this precipitate, dichloromethane was added to redissolve it, and then 100 mfL 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 ml of methanol solution containing 2 g of polyvinyl butyral, 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 0.41 Lm to form a charge generation layer.

Next, a charge transport layer was formed in the same manner as in Example 1 except that Compound Example (4) was used on the charge generation layer.

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

Show the results.

vo knee 700V vl knee 690Vel
/2: 2.7fLux, sec -1 Vo Knee 700V VL Knee 200Vm Momime VD? -670V VL Knee 240V Strong exposure history part -1 ΔvD=+lOv Δ■L:+1OviiKuukikyuyari ΔvD:+20v ΔvL:+20v Example 18 An 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 having a dry film thickness of Ig.m. The charge transport layer and charge generation layer of Example 6 were sequentially laminated thereon, and an electrophotographic photoreceptor was prepared in 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 10. Show the results.

vo: +700V Vl: +685VE
l/2: 3.0Jlux, sec First - Kazutomo Vo: +700V VL: +200V 10KljiL twist VD: +660V VL: +245V -1 for the strong exposure history part ΔVp: -10V ΔVL: +10Vi Gokusara Kuge ΔvD: +10v ΔvL: +20v Example 19 Soluble nylon (6-66-610-1g
A 5% methanol solution of a quaternary nylon copolymer) was applied to form a subbing layer having a dry thickness of 0.51 Lm.

Next, 5g of the pigment with the following structural formula was added to 95ml of tetrahydrofuran.
The mixture was dispersed in Jl for 200 hours using a sand mill.

Next, a solution prepared by dissolving 5 g of Compound Example (7) and 10 g of bisphenol Z type polycarbonate (viscosity average molecular weight 30,000) in 30 mfL of chlorobenzene was added to the dispersion prepared above, and the mixture was further dispersed for 2 hours using a sand mill. This dispersion was applied onto the previously formed subbing layer using a Mayer bar so that the film thickness after drying would be 20 gm, 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 700V Vl knee 690Vel
/2: 3.0 sentences ux, sec Handling -1 VD Knee 700V VL Knee 200V1 Kyou Tachisara Kuge VD Knee 670V VL Knee 240V About the strong exposure history part -1 ΔvD Knee lOv ΔvL2±0v i-Kuo Kuge ΔvD: + l Ov ΔvL: + 2
0 v [Effects of the Invention] The electrophotographic photoreceptor containing the compound represented by the general formula (I) of the present invention has high sensitivity, and also exhibits no fluctuation in bright area potential and dark area potential during continuous image formation by repeated charging exposure. A small and durable electrophotographic photoreceptor.

Claims (1)

[Scope of Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive support, characterized in that the photosensitive layer has a layer containing a compound represented by the following general formula (I). Photographic photoreceptor. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (I) In the formula, Ar represents an aryl group having at least a substituted amino group at the ortho position, and R_1, R_2, and R_3 are alkyl groups that may have substituents. , represents 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 general formula (I), Ar is a compound represented by the following general formula (II). General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (II) In the formula, R_4 and R_5 are an alkyl group that may have a substituent, an aralkyl group that may have a substituent, and a represents an aromatic ring group that may have a substituent or a heterocyclic group that may have a substituent. Further, R_4 and R_5 may form a ring together with the nitrogen atom to which they are bonded. R_6 and R_7 represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a nitro group, a cyano group, or a substituted amino group.