JPH0792607B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor having a low molecular organic photoconductor in a photosensitive layer, which provides improved electrophotographic properties.

[Conventional technology]

Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known as photoconductive materials used in electrophotographic photoreceptors. These photoconductive materials have a number of advantages, such as being able to be charged to an appropriate potential in the dark, having a low dissipation of charges in the dark, or being capable of rapidly dissipating charges by light irradiation. On the other hand,
It has various drawbacks. For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, and pressure.In particular, when the ambient temperature exceeds 40 ° C, crystallization becomes noticeable, resulting in reduced chargeability and white spots on images. There is a drawback that occurs. Cadmium sulfide-based photoconductors cannot obtain stable sensitivity in a humid environment. Zinc oxide type photoconductors require a sensitizing effect by a sensitizing dye typified by rose bengal, but such a sensitizing dye causes charge deterioration due to corona charging and photobleaching due to exposure light for a long time. It has a drawback that it cannot provide a stable image.

On the other hand, various organic photoconductive polymers such as polyvinylcarbazole have been proposed, but these polymers are superior to the above-mentioned inorganic photoconductive materials in film forming property and light weight. Nevertheless, until today, its practical application has been difficult. This is because sufficient film-forming properties have not yet been obtained, and sensitivity, durability, and stability due to environmental changes are inferior to those of inorganic photoconductive materials. In addition, hydrazone compounds disclosed in U.S. Pat.No. 4,150,987, triarylpyrazoline compounds described in U.S. Pat.No. 3837851, JP-A-51-94828, JP-A-51-94829 and the like. Low molecular weight organic photoconductors such as the described 9-styrylanthracene compounds have been proposed. Such low molecular weight organic photoconductor, by properly selecting the binder to be used, it has become possible to solve the drawback of film-forming property which has been a problem in the field of organic photoconductive polymers, It is not enough in terms of sensitivity.

Under these circumstances, in recent years, a laminated structure has been proposed in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer. An electrophotographic photosensitive member having this laminated structure as a photosensitive layer can be improved in terms of sensitivity to visible light, charge retention, surface strength and the like. Such electrophotographic photoreceptors are disclosed, for example, in US Pat. Nos. 3,838,851 and 3,871,882.

However, the sensitivity and characteristics are not always sufficient in the conventional low-molecular weight organic photoconductor and the electrophotographic photoreceptor used in the charge transport layer, and the potential in the bright portion and the potential in the dark portion are particularly large when repeatedly charged and exposed. Fluctuates greatly and there are points to be improved.

[Problems to be solved by the invention]

An object of the present invention is to provide an electrophotographic photosensitive member which eliminates the above-mentioned drawbacks or disadvantages.

Another object of the present invention is to provide an electrophotographic photosensitive member using a novel organic photoconductor.

Another object of the present invention is to provide an electrophotographic photosensitive member using a novel charge transporting material in a laminated type photosensitive layer in which a charge generating layer and a charge transporting layer are functionally separated.

[Means and Actions for Solving Problems]

The present invention is characterized in that in an electrophotographic photosensitive member laminated on a conductive support with a photosensitive layer, the photosensitive layer contains a compound represented by the following general formula.

(However, in the formula, R ¹ , R ² , R ³ and R ⁴ may have a substituent, an alkyl group such as ethyl, propyl and the like, a benzyl which may have a substituent, phenethyl, naphthylmethyl and the like. It represents an aralkyl group, an aromatic ring group such as phenyl or naphthyl which may have a substituent, a heterocyclic group such as pyridyl, quinolyl or thienyl which may have a substituent, or a hydrogen atom.
Further, as the substituent which R ¹ , R ² , R ³ and R ⁴ may have, an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy, ethoxy and propoxy, fluorine, chlorine and bromine. And halogen atoms, and substituted amino groups such as dilylamino and diphenylamino.

R ³ and R ⁴ may together form a ring, and examples thereof include the following.

Here, R ⁷ and R ⁸ represent an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy, ethoxy and propoxy, a halogen atom such as fluorine, chlorine and bromine, or a hydrogen atom, and R ⁹ and R ¹⁰ represents an alkyl group such as methyl, ethyl or propyl, or a hydrogen atom.

R ⁵ and R ⁶ represent an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy, ethoxy and propoxy, a halogen atom such as fluorine, chlorine and bromine, or a hydrogen atom.

On the other hand, Ar ′ represents an aromatic ring group which may have a substituent such as phenyl, naphthyl and anthralyl, or a heterocyclic group which may have a substituent such as pyridyl, quinolyl, thienyl and furyl. Further, the substituent which Ar ′ may have is an alkyl group such as methyl, ethyl and propyl, an alkoxy group such as methoxy, ethoxy and propoxy, and a halogen atom such as fluorine, chlorine and bromine.

Incidentally, when a compound in which R ¹ and R ² in the general formula are both aromatic ring groups is used as a charge transporting substance, the sensitivity and the JP are extremely superior to other cases, and the excellent electron A photographic photoreceptor is provided.

Typical examples of the compounds represented by the formula will be given below.

A synthesis example of the exemplified compound is shown below.

<Synthesis Example of Exemplified Compound No. (34)> To about 200 cc of dimethyl sulfoxide, 2.34 g (58.5 mmol) of 60% oily sodium hydride was added, and heated and stirred in an oil bath at about 80 ° C. until generation of hydrogen was completed, When the generation of hydrogen is completed, it is cooled with ice and the literature is known (eg Indian.J.Chem.Sect
B. 16 B (9) 828 (1978)) 10-
Diphenylidene-9-anthrone 20.0 g (55.8 mmol) and diethyl p-nitrobenzylphosphonate 15.3 g (61.4 mmo
A solution of l) in dimethylsulfoxide (about 50 cc) is added dropwise. After the addition is complete, the temperature is returned to room temperature and after stirring for 30 minutes, an oil bath (about 10
After stirring at 0 ° C for 10 hours, the usual post-treatment was performed to give 9- (p-nitrobenzylidene) -10-diphenylidene anthracene.
11.9 g was obtained. This compound is reduced by a conventional method,
The obtained amino compound and p-iodotoluene were used for Ullman
N reactions were carried out to obtain 8.4 g of the target exemplified compound No. (34) (yield 24.0%).

<Results of elemental analysis> Calculated value (%) Measured value (%) C 91.83 91.80 H 5.93 5.98 N 2.23 2.22 Compounds other than the synthesis examples are generally synthesized by the same method.

In a preferred embodiment of the present invention, the compound represented by the above general formula can be used as a charge-transporting substance of an electrophotographic photosensitive member having a photosensitive layer functionally separated into a charge-generating layer and a charge-transporting layer.

The charge transport layer in the present invention is preferably formed by applying a solution prepared by dissolving the compound represented by the above general formula and a binder in a suitable solvent and drying. 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 resin, alkyd resin, polycarbonate, polyurethane or Copolymers such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer and the like can be mentioned. In addition to such insulating polymers, organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene and polyvinylpyrene can also be used.

The compounding ratio of the binder and the compound represented by the general formula is preferably 10 to 500 parts by weight per 100 parts by weight of the binder.

The charge transport layer is electrically connected to the charge transport layer described below, and has a 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. is doing. At this time, the charge transport layer may be laminated on or below the charge generation layer. However, the charge transport layer is preferably laminated on the charge generation layer.
Since the charge transport layer has a limit for transporting charge carriers, the film thickness cannot be increased more than necessary. Generally, it is 5 microns to 30 microns, but the preferred range is 8 microns to 20 microns.

The organic solvent used when forming such a charge transport layer is
Although it depends on the kind of the binder used, it is preferably selected from those which do not dissolve the charge generation layer or the undercoat layer described below. Specific organic solvents include alcohols such as methanol, ethanol and isopropanol, acetone,
Methyl ethyl ketone, ketones such as cyclohexanone, N, N-dimethylformamide, amides such as N, N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran, dioxane, ethers such as ethylene glycol monomethyl ether,
Esters such as methyl acetate and ethyl acetate, aliphatic halogenated hydrocarbons such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride and trichloroethylene, or benzene, toluene, xylene, ligroin, monochlorobenzene, dichlorobenzene, etc. And the like aromatic compounds can be used.

The coating can be carried out using a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a Meyer bar coating method, a blade coating method, a roller coating method or a curtain coating method.
Drying is preferably a method of drying by touching at room temperature and then drying by heating. Heat drying at a temperature of 30 ℃ to 200 ℃ for 5 minutes to 2
It can be done statically or under blast for a time range of hours.

The charge transport layer of the present invention may contain various additives. Examples of such additives include diphenyl, diphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, and dilauryl thiopropionate. , 3,5-dinitrosalicylic acid, various fluorocarbons and the like.

The charge transport layer used in the present invention includes selenium, selenium-tellurium, inorganic charge generating substances such as amorphous silicon, pyrylium dyes, thiaparylium dyes, azurenium dyes, thiacyanine dyes, quinocyanine dyes, and azurenium dyes. It is selected from polycyclic quinone pigments such as cationic dyes, phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, and biantrone pigments, indico pigments, quinacridone pigments, and organic charge generating substances such as azo pigments. Also, a separate vapor deposition layer or resin dispersion layer can be used.

Among the charge generating substances used in the present invention, azo pigments are particularly diversified and it is difficult to specify the structure, but the structures of the azo pigments having particularly high effects are specifically described below. As a general formula of azo pigments, the central skeleton is
A, A- (N = N-Cp) _{n If the} coupler portion is represented as Cp (where n = 2 or 3), specific examples of A include the following.

Also, as a concrete example of Cp, Etc. The central skeleton A and the coupler Cp are combined with each other to form a pigment as a charge generating substance.

The charge generation layer can be formed by dispersing the above-mentioned charge generation substance in an appropriate binder and coating it on a substrate, or can be obtained by forming a vapor deposition film by a vacuum vapor deposition device. . The binder that can be used when forming the charge generation layer by coating can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene. . Preferably, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin,
Polyacrylamide, polyamide, polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin,
Insulating resins such as casein, polyvinyl alcohol, and polyvinylpyrrolidone can be mentioned. The resin contained in the charge generation layer is suitably 80% by weight or less, preferably 40% by weight or less. The organic solvent used in the coating, methanol, ethanol, alcohols such as isopropanol, acetone, methyl ethyl ketone, ketones such as cyclohexanone, N, N-dimethylformamide, amides such as N, N-dimethylacetamide, dimethyl Sulfoxides such as sulfoxides, ethers such as tetrahydrofuran, dioxane and ethylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, aliphatic halogenation such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, trichloroethylene Hydrocarbons or benzene, toluene,
Aromatic compounds such as xylene, ligroin, monochlorobenzene, and dichlorobenzene can be used.

The coating can be carried out using a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a Meyer bar coating method, a blade coating method, a roller coating method or a curtain coating method.

The charge generation layer contains as much of the organic photoconductor as possible to obtain sufficient absorbance, and is a thin film layer, such as a thin film layer, for injecting carriers into the charge transport layer within the lifetime of the generated charge carriers. It is preferable that the thin film layer has a thickness of 5 μm or less, more preferably 0.01 μm to 1 μm. This means that most of the amount of incident light is absorbed in the charge generation layer to generate many charge carriers, and the generated charge carriers are not deactivated by recombination or trapping (trap) to the charge transport layer. It is due to the need to inject.

The photosensitive layer having such a laminated structure of the charge generation layer and the charge transport layer is provided on a support having a conductive layer. As the support having a conductive layer, use is made of a conductive material such as aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold or platinum. And aluminum, aluminum alloys,
A plastic having a layer formed by vacuum deposition of indium oxide, tin oxide, an indium oxide-tin oxide alloy, or the like (for example, polyethylene, polypropylene,
Polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluoroethylene, etc.), conductive particles (for example, aluminum powder, titanium oxide, tin oxide, zinc oxide, carbon black, silver particles, etc.) together with a suitable binder in plastic or the above conductive material. A support coated on a conductive support, a support obtained by impregnating plastic or paper with conductive particles, a plastic having a conductive polymer, or the like can be used.

An undercoat layer having a barrier function and an adhesive function can be provided between the conductive layer and the photosensitive layer. The undercoat layer is casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
It can be formed of acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide and the like.

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

In the case of using a photoreceptor in which a conductive layer, a charge generation layer and a charge transport layer are laminated in this order, the compound represented by the above general formula as a charge transport substance is a hole transport layer, so the surface of the charge transport layer is negatively charged. When exposed after charging, 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 charges, causing a decrease in surface potential and causing unexposed areas. An electrostatic contrast occurs between the two. At the time of development, it is necessary to use a positively charged toner, contrary to the case of using an electron transport substance.

In another embodiment of the present invention, the above-mentioned disazo pigments or U.S. Pat.Nos. 3,554,745, 3,567,438 and 358,650.
Pyrylium dyes, thiapyrylium dyes, serenapyrylium dyes, benzopyrylium dyes, etc.
A photoconductive pigment or dye such as a benzothiapyrylium dye, a naphthopyrylium dye, or a naphthothiapyrylium dye can also be used as a sensitizer.

Further, in another specific example, a eutectic complex of a pyrylium dye disclosed in US Pat. No. 3,684,502 and an electrically insulating polymer having an alkylidene diarylene moiety can be used as a sensitizer. This eutectic complex is, for example, 4- [4
-Bis- (2-chloroethyl) aminophenyl] -2,6
-Diphenylthiapyrylium perchlorate and poly (4,
4'-isopropylidene diphenylene carbonate)
A halogenated hydrocarbon solvent (for example, dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2-trichloroethane,
After dissolving in chlorobenzene, bromobenzene, 1,2-dichlorobenzene), a non-polar solvent (e.g., hexane, octane, decane, 2,2,4-trimethylbenzene, ligroin) is added to the particulate co-solvent. The styrene-butaneene polymer, silicone resin, vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-acrylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, polyvinyl Butyral, polymethylmethacrylate, poly-N-butylmethacrylate, polyesters, cellulose esters, etc. may be contained as a binder, and further another specific example of the present invention is the function-separated type electron described above. Not limited to photographic photoreceptors, Compounds can be mentioned electrophotographic photosensitive member is contained in the photosensitive layer of the single layer with a charge generating material.

The electrophotographic photoreceptor of the present invention can be widely used not only in electrophotographic copying machines but also in electrophotographic application fields such as laser printers, CRT printers and electrophotographic plate making systems.

According to the present invention, a high-sensitivity electrophotographic photosensitive member can be provided, and this electrophotographic photosensitive member has an advantage that there is little fluctuation in the bright portion potential and the dark portion potential when repeatedly charged and exposed. There is.

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

Example 1 β-type copper phthalocyanine (trade name: Lionol Blue NCB Tone
r, Toyo Ink Mfg. Co., Ltd. was sequentially refluxed in water, ethanol, and benzene, and was then purified to give a pigment 7 g, polyester (trade name: Polyester Adhesive 49,000)
(Solid content 20%, manufactured by DuPont) 14 g, toluene 35 g, and dioxane 35 g were mixed, and dispersed by a ball mill for 6 hours to prepare a coating liquid. This coating solution was applied onto an aluminum sheet with a Meyer bar so that the dry film thickness was 0.5 micron, to form a charge generation layer.

Next, the above exemplified compound No. (13) was used as a charge transporting substance.
g and polycarbonate (trade name: Panlite K-1300, Teijin Kasei Co., Ltd.) 7 g in a mixed solvent of tetrahydrofuran 35 g and chlorobenzene 35 g with stirring to obtain a solution, and the solution was added to the above charge generation layer and Meyer. Dry film thickness at bar 11
It was coated so as to have a thickness of micron to produce an electrophotographic photoreceptor having a photosensitive layer having a two-layer structure.

The electrophotographic photosensitive member manufactured in this manner was corona-charged at -5 kV by a static method using an electrostatic copying paper tester (Model-SP-428, manufactured by Kawaguchi Denki Co., Ltd.) and held for 1 second in the dark. After that, exposure was performed with an illuminance of 5 lux, and charging characteristics were examined.

As the charging characteristics, the surface potential (V ₀ ) and the exposure dose (E _1/2 ) required to attenuate the potential (V ₁ ) when dark-decayed for 1 second to 1/2 were measured.

Further, in order to measure the fluctuations in the light potential and the dark potential when repeatedly used, the electrophotographic photosensitive member manufactured in this example was used as a cylinder for a photosensitive drum of a PPC copying machine (NP-150Z Canon Co., Ltd.). Then, the same machine was used to make a copy of 50,000 sheets, and the fluctuations of the light potential (V _L ) and the dark potential (V _D ) at the initial stage and after the 50,000 copies were measured.

The results are shown below.

Examples 2 to 16 In each of the examples, the compound N exemplified in place of the compound No. (13) used as the charge transport material used in Example 1 was used.
o. (2), (3), (6), (8), (12), (16),
(18), (20), (23), (25), (29), (32),
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that (34) and (39) were used and the following pigments were used as the charge generating substance.

The electrophotographic characteristics of each electrophotographic photosensitive member were measured by the same method as in Example 1. The results are shown below.

As is clear from these results, it can be seen that when a compound in which R ¹ and R ² in the general formula are both aromatic ring groups is used as the charge transport material, it is superior to other cases.

Example 16 Aqueous ammonia solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 22.2 ml of water) on an aluminum cylinder.
Is applied by the dip coating method and dried to apply a coating amount of 1.0 g / m
An undercoat layer of ² was formed.

Next, 1 part by weight of the charge generating substance shown below, Butyral resin (S-REC BM-2: Sekisui Chemical Co., Ltd.)
1 part by weight and 30 parts by weight of isopropyl alcohol were dispersed by a ball mill disperser for 4 hours. This dispersion was applied onto the previously formed subbing layer by a dip coating method and dried to form a charge generation layer. The film thickness at this time was 0.3 micron.

Next, as a charge transporting substance, the above exemplified compound No. (35) 1
1 part by weight of polysulfone (P1700: manufactured by Union Carbide Co., Ltd.) and 6 parts by weight of monochlorobenzene were mixed and dissolved by stirring with a stirrer. This liquid was applied onto the charge generation layer by a dip coating method and dried to form a charge transport layer. The film thickness at this time was 12 microns.

A corona discharge of -5 kV was applied to the electrophotographic photosensitive member thus manufactured. The surface potential at this time was measured (initial potential
V ₀ ). Furthermore, the surface potential of this electrophotographic photosensitive member was measured after leaving it in the dark for 5 seconds. The sensitivity was evaluated by measuring the exposure dose (E _1/2 microjoule / cm ² ) required to attenuate the potential V _K after dark decay to _1/2 . At this time, a ternary semiconductor laser of gallium / aluminum / arsenic (output: 5 mW; oscillation wavelength 780 nm) was used as a light source. These results were as follows.

V ₀ : −697 V Charge retention rate: 98% E _1/2 : 1.2 microjoules / cm ² Next, the above electrophotographic photosensitive member was applied to a laser beam printer (LBP-CX made by Canon) which is an electrophotographic printer of reversal development method equipped with the same semiconductor laser as LBP-CX.
The photosensitive member of No. 1 was replaced and set, and an actual image forming test was conducted. The conditions are as follows.

Surface potential after primary charging: -700V, surface potential after image exposure;
-150V (exposure 2.0μJ / cm ² ), charging potential at transfer + 6k
V, developer polarity; negative polarity, process speed; 50 mm / sec,
Development condition (development bias): -450V, image exposure scanning method; image scan, pre-charge exposure before primary charging; 50 lux · sec red full exposure image formation was performed by line scanning with a laser beam according to a character signal and an image signal. letter,
Good prints were obtained for both images.

Example 17 3 g of 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate and 5 g of the above-exemplified compound (40) as a charge-transporting substance in polyester (Polyester Adhesive 49000: manufactured by DuPont) Toluene (5
It was mixed with 100 ml of 0) -dioxane (50) solution and dispersed for 6 hours with a pole mill. This dispersion was applied onto an aluminum sheet with a Meyer bar so that the film thickness after drying would be 15 microns.

The electrophotographic characteristics of the electrophotographic photosensitive member thus manufactured were measured by the same method as in Example 1. The results are shown below.

V ₀ : −695 volt V ₁ : −688 volt E _1/2 : 1.3lux.sec Initial V _D : −695 volt _VL : −122 volt After running 50000 sheets V _D : −690 volt _VL : −139 volt Example 18 Aqueous ammonia solution of casein (casein 1
1.2 g, 28% ammonia water 1 g, and water 222 ml) were applied and dried with a Meyer bar to form an adhesive layer having a film thickness of 1 micron.

Next, with a disazo pigment 5g having the following structure, 2 g of butyral resin (degree of butyralization: 63 mol%) was dispersed in a solution of 95 ml of ethanol and dispersed, and then applied onto the adhesive layer to form a charge generation layer having a thickness of 0.4 micron after drying.

Next, 5 g of the above exemplified compound No. (24) as a charge transport material
And poly-4,4'-dioxydiphenyl-2,2-propanecarbonate (viscosity average molecular weight 30,000) 5 g dissolved in dichloromethane 150 ml, applied on the charge generation layer, dried,
An electrophotographic photoreceptor was manufactured by forming a charge transport layer having a thickness of 11 microns.

The electrophotographic characteristics of the electrophotographic photosensitive member thus manufactured were measured by the same method as in Example 1. The results are shown below.

V ₀ : −698 Volt V ₁ : −685 Volt E _1/2 : 1.3lux.sec Initial V _D : −696 Volt V _L : −129 Volt After Endurance of 50000 Sheets V _D : −690 Volt V _L : −152 Volt Example 19 A 0.2 mm thick molybdenum plate (support) whose surface was cleaned was fixed at a predetermined position in a glow discharge vapor deposition tank. Next, the inside of the tank was evacuated to a vacuum degree of about 5 × 10 ⁻⁶ torr. After that, the input voltage of the heater was increased to stabilize the molybdenum substrate temperature at 150 ° C. After that, hydrogen gas and silane gas (15% by volume relative to hydrogen gas) were introduced into the tank, and the gas flow rate was stabilized at 0.5 torr by adjusting the main valve of the evaporation tank. Next, high-frequency power of 5 MHz was applied to the induction coil to generate glow discharge inside the coil and set the input power to 30 W. Under the above conditions, an amorphous silicon film is grown on the support and the film thickness is 2μ.
The glow discharge was stopped after maintaining the same conditions until. After that, turn off the heater and high-frequency power supply, wait until the temperature of the support reaches 100 ° C, close the outflow valves for hydrogen gas and silane gas, temporarily lower the pressure in the tank to 10 ^-5 torr or less, and then return to atmospheric pressure. The support was taken out. Then, a charge transport layer was formed on this amorphous silicon layer in exactly the same manner as in Example 1 except that the exemplified compound was used as the charge transport substance.

The electrophotographic photosensitive member thus obtained was placed in a charging exposure experimental apparatus, corona-charged at 6 kV, and immediately irradiated with a light image. The light image was illuminated through a transmissive test chart using a tungsten lamp-light source. Immediately thereafter, a chargeable developer (including toner and carrier) was cascaded onto the surface of the electrophotographic photosensitive member to obtain a good toner image on the surface.

Example 20 3 g of 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate and 3 g of poly (4,4'-isopropylidene diphenylene carbonate) were sufficiently dissolved in 200 ml of dichloromethane, and then toluene was added. 100 ml was added to precipitate the eutectic complex. After separating this precipitate, it was redissolved by adding dichloromethane, 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 ml of a methanol solution containing 2 g of polyvinyl butyral and dispersed by a ball mill for 6 hours. This dispersion was applied on an aluminum plate having a casein layer by a Meyer bar so that the film thickness after drying would be 0.4 μm to form a charge generation layer.

Then, a coating layer for the charge transport layer was formed on this charge generation layer in exactly the same manner as in Example 1 except that the exemplified compound No. (41) was used.

The electrophotographic characteristics of the electrophotographic photosensitive member thus produced were measured by the same method as in Example 1. The results are shown below.

V ₀ : −695 Volt V ₁ : −686 Volt E _1/2 : 2.2lux.sec Initial V _D : −696 Volt V _L : −149 Volt After 50,000 sheets endurance V _D : −686 Volt V _L : −188 Volt Example 21 5 g of the same eutectic complex used in Example 20 and 5 g of the above exemplified compound No. (35) as a charge transport material were added to 150 ml of a tetrahydrofuran solution of polyester (Polyester Adhesive 49000: manufactured by DuPont). And mixed and stirred sufficiently. This solution was applied onto an aluminum sheet with a Meyer bar so that the film thickness after drying would be 15 μm.

The electrophotographic characteristics of this electrophotographic photosensitive member were measured by the same method as in Example 1. The results are shown below.

V ₀ : −697 Volt V ₁ : −690 Volt E _1/2 : 1.5lux.sec Initial V _D : −696 Volt V _L : −132 Volt After 50000 Sheets Endurance V _D : −690 Volt V _L : −155 Volt [Effects of the Invention] The electrophotographic photosensitive member of the present invention, by using the specific compound represented by the general formula described above as a charge transporting material,
High sensitivity and high durability (potential fluctuation due to repeated use) can be exerted, and a remarkable effect that it can be applied to a wide range of electrophotographic application fields is exhibited.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer laminated on a conductive support, wherein the photosensitive layer contains a compound represented by the following general formula: (However, in the formula, R ¹ , R ² , R ³ and R ⁴ are an alkyl group which may have a substituent, an aralkyl group which may have a substituent,
It represents an aromatic ring group which may have a substituent, a heterocyclic group which may have a substituent, or a hydrogen atom. R ³ and R ⁴ may together form a ring. R ⁵ and R ⁶ are alkyl groups,
An alkoxy group, a halogen atom, or a hydrogen atom is shown.
Ar ′ represents an aromatic ring group which may have a substituent or a heterocyclic group which may have a substituent. )