JPH0679164B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: 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] Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are conventionally known as photoconductive materials used in electrophotographic photoreceptors. These materials have many advantages such as being able to be charged to an appropriate potential in a dark place, less dissipation of charges in a dark place, and being capable of rapidly dissipating charges by light irradiation, but various disadvantages. have. For example, the temperature, humidity,
Crystallization easily progresses due to factors such as dust and pressure, and especially when the ambient temperature exceeds 40 ° C., crystallization becomes remarkable, and there is a drawback that the chargeability is lowered and white spots are generated on the image.
Cadmium sulfide-based photoconductors do not provide stable sensitivity in humid environments, and zinc oxide-based photoconductors require the sensitizing effect of sensitizing dyes represented by rose bengal. The dye has a drawback that a stable image cannot be provided for a long period of time because it causes charge deterioration due to corona charging and photobleaching due to exposure light.

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. Despite this, it has been difficult to put it into practical use until now, because it has not been possible to obtain sufficient film-forming properties, and it is inferior to inorganic photoconductive materials in terms of sensitivity, durability and stability due to environmental changes. Was because

Further, hydrazone compounds disclosed in U.S. Pat. No. 4,150,987, triarylpyrazoline compounds described in U.S. Pat. No. 3,738,851, JP-A-51-94828 and JP-A-5-94828.
A low molecular weight organic photoconductor such as a 9-styrylanthracene compound described in JP-A 1-94829 is proposed.
Such a low molecular weight organic photoconductor, by properly selecting the binder to be used, it has become possible to eliminate 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.

As such an electrophotographic photoreceptor, for example, US Pat.
No. 851, No. 3871882, and the like.

However, in an electrophotographic photoreceptor using a conventional low-molecular weight organic photoconductor for the charge transport layer, the sensitivity and characteristics are not always sufficient, and especially when repeatedly charged and exposed for a long period of time, bright areas are not exposed. There is a point that the fluctuations of the potential and the dark part potential should be greatly improved.

[Problems to be Solved by the Invention] The present invention provides an electrophotographic photoreceptor that solves the above-mentioned drawbacks or disadvantages, a novel organic photoconductor, and a charge generation layer and a charge transport layer. It is an object of the present invention to provide a novel charge transporting material in a laminated type photosensitive layer having functionally separated layers.

[Means and Actions for Solving Problems] The present invention comprises an electrophotographic photoreceptor having a layer containing a substituted diamino compound represented by the following general formula.

General formula In the formula, A represents a divalent aromatic ring group or a divalent heterocyclic group which may have a substituent, and R ₁ and R ₂ each represent an alkyl group, an aralkyl group or an aryl which may have a substituent. A group or a heterocyclic group, or R ₁ and R ₂ represent a residue forming a heterocycle with a nitrogen atom, R ₃ , R ₄ , and R ₅ are hydrogen atoms, alkyl groups,
It represents an alkoxy group, an aralkyl group, an aryl group, a halogen atom, a nitro group, a cyano group, a hydroxyl group or an acyl group.

More specifically, in the above general formula, A is a divalent aromatic ring group such as a phenylene group, a naphthylene group, an anthrylene group or a fluorenylene group, a divalent heterocyclic group formed by eliminating two hydrogen atoms from furan or thiophene. And cyclic groups, such as alkyl groups such as methyl, ethyl, propyl and butyl, aralkyl groups such as benzyl, phenethyl and naphthylmethyl, alkoxy groups such as methoxy, ethoxy, propoxy and butoxy, phenyl, naphthyl and the like. It may have a substituent such as an aryl group, a halogen atom such as fluorine, chlorine, bromine and iodine, a nitro group, a cyano group, or an acyl group such as acetyl and benzoyl.

R ₁ and R ₂ are alkyl groups such as methyl, ethyl, propyl and butyl, aralkyl groups such as benzyl, phenethyl and naphthylmethyl, aryl groups such as phenyl, naphthyl and fluorenyl, pyridyl, quinolyl, benzoxazoyl and benzotriazolyl. And a heterocyclic group such as carbazolyl, R ₁ and R ₂ may be the same or different, and
R ₁ and R ₂ represents a residue forming a heterocyclic ring such as carbazole together with the nitrogen atom, further the R _1, R ₂ may have a substituent, the substituent is the same groups as in the A is there.

R ₃ , R ₄ and R ₅ are hydrogen atoms, alkyl groups such as methyl, ethyl, propyl and butyl, alkoxy groups such as methoxy, ethoxy, propoxy and butoxy, aralkyl groups such as benzyl, phenethyl and naphthylmethyl, phenyl and naphthyl. , Aryl groups such as anthryl, fluorine, chlorine,
Halogen atom such as bromine and iodine, nitro group, cyano group,
A hydroxyl group or an acyl group such as acetyl or benzoyl is shown.

The present invention achieves its object by using a substituted diamino compound represented by the above general formula as a charge transporting substance, and particularly when A in the general formula is a phenylene group, its effect is large and preferable.

Typical examples of the substituted diamino compounds represented by the general formula are listed below.

A method for synthesizing the above compound will be described.

Synthesis of Compound Example (1) 11.95 g (0.0385 mol) of N, N, N-phenyl- (4-amino) phenyl-α-naphthylamine was dissolved in 250 ml of DMF,
9.24 g (0.231 mol) of oily sodium hydride (60%) is gradually added under ice cooling. After stirring for 30 minutes, 36.03 g of ethyl iodide
A solution prepared by dissolving (0.231 mol) in 80 ml of DMF is added dropwise over 15 minutes. After finishing the dropping, return to room temperature for 1 hour, then 80 ℃
It is heated to and stirred for 4 hours.

After allowing to cool, the reaction product was poured into about 1 part of ice water, and 300 m of ethyl acetate was added.
The mixture was extracted 3 times with 1 l, the organic layer was washed with water, dried over sodium sulfate, and dried under reduced pressure. The yield was 74%.

Elemental analysis Calculated value Measured value C 85.21 85.33 H 7.15 7.10 N 7.64 7.57 In the case of other compounds N, N-phenyl-α-naphthylamine derivative, Cl
-A-NO ₂ or Br-A-NO ₂ (A is the same as A in the general formula) was subjected to the Uhlmann reaction in the presence of copper powder and potassium carbonate in the usual manner to give a tertiary amine, which was obtained after reduction. Is treated according to the above-mentioned synthesis example, or further subjected to the Uhlmann reaction to introduce an aryl group, and then treated in the same manner.

In a preferred embodiment of the present invention, the substituted diamino compound represented by the above general formula is used as the charge transporting substance of the electrophotographic photoreceptor in which the photosensitive layer is functionally separated into the charge generating layer and the charge transporting layer.

The charge transport layer in the present invention is preferably formed by applying a solution of the substituted diamino compound represented by the above general formula and a binder in a suitable solvent and drying.

Examples of the binder used include polyallate, polysulfone, polyamide, acrylic resin, acrylonitrile resin, methacrylic resin, polyvinyl chloride, polyvinyl acetate, phenol resin, epoxy resin, polyester, alkyd resin, polycarbonate, polyurethane or A copolymer containing two or more of the repeating units of these resins, for example, a styrene-butadiene copolymer,
Examples thereof include styrene-acrylonitrile copolymer, styrene-maleic acid copolymer and the like. Also,
In addition to such insulating polymers, organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene and polyvinylpyrene can also be used.

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

The charge transport layer is electrically connected to the charge generation layer described below and has a function of receiving the 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 stacked on or below the charge generation layer, but the charge transport layer is preferably stacked on the charge generation layer.

Since this charge transport layer has a limit of transporting charge carriers, the film thickness cannot be increased more than necessary. Generally, it is in the range of 5 to 30μ, preferably 8 to 20μ.

The solvent used for forming such a charge transport layer varies depending on the kind of the binder used, or is preferably selected from those which do not dissolve the charge generation layer or the undercoat layer described below.

As the solvent, methanol, ethanol, alcohols such as isopropanol, acetone, methyl ethyl ketone, ketones such as cyclohexanone, N, N-dimethylformamide, N, N-amide such as dimethylacetamide, sulfoxides such as dimethyl sulfoxide, tetrahydrofuran , Ethers such as dioxane and 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, benzene, toluene , Aromatic hydrocarbons such as xylene, ligroin, monochlorobenzene, and dichlorobenzene.

Coating is dip coating method, spray coating method,
Spinner coating method, bead coating method, Meyer bar coating method, blade coating method,
It can be carried out by using a coating method such as a roller coating method or a curtain coating method.

Drying is preferably performed by drying by touching at room temperature and then drying by heating. The heat drying can be carried out at 30 to 200 ° C. for 5 minutes to 2 hours while still or under blowing air.

The charge transport layer in the invention may contain various additives. As additives, diphenyl, diphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, benzophenone, chlorinated paraffin, dilauryl thiopropionate, 3 There are 5,5-dinitrosalicylic acid and various fluorocarbons.

The charge generation layer in the present invention is selenium, selenium-tellurium, pyrylium, thiapyrylium dye, azurenium dye, phthalocyanine pigment, anthanthrone pigment, dibenzpyrenequinone pigment, pyranthrone pigment, trisazo pigment, disazo pigment, azo pigment, A separate vapor deposition layer or resin dispersion layer selected from a charge generating substance such as indigo pigment, quinacridone pigment, thiacyanine, asymmetric quinocyanine, quinocyanine or amorphous silicon described in JP-A-54-143645 can be used.

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

Charge generation material (1) Amorphous silicon (2) Selenium-tellurium (3) Selenium-arsenic (4) Cadmium sulfide (58) Squaric acid methine dye (59) Indigo dye (60) Thioindigo dye (61) β-type copper phthalocyanine The charge generation layer can be formed by dispersing the above-mentioned charge generation substance in a suitable binder and coating it on a substrate, or can also be obtained by forming a vapor deposition film by a vacuum vapor deposition device. it can.

The binder that can be used when the charge generation layer is formed by coating can be selected from a wide range of insulating resins.
It can be selected from organic photoconductive polymers such as N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene.

Preferably, polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, allyl resin, polyacrylamide, polyamide, polyvinyl pyridine, cellulosic resin, polyurethane, casein. Insulating resins such as polyvinyl alcohol and polyvinylpyrrolidone can be used.

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

Solvents used during coating include alcohols such as methanol, ethanol, 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 trichlorethylene,
Examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, ligroin, monochlorobenzene, and dichlorobenzene.

Coating is dip coating method, spray coating method,
Spinner coating method, bead coating method, Meyer bar coating method, blade coating method,
It can be carried out by using a coating method such as a roller coating method or a curtain coating method.

The charge generation layer contains as much of the charge generation material as possible to obtain sufficient absorbance, and in order to shorten the range of the generated charge carrier, a thin film layer such as 5 μm is used.
Below, a thin film layer having a thickness of preferably 0.01 to 1 μm is desirable.

This means that most of the amount of incident light is absorbed by the charge generation layer, generating a large number of charge carriers, and the generated charge carriers are injected into the charge transport layer without being deactivated by recombination or trapping. Is due to the need to.

The photosensitive layer having such a laminated structure of the charge generation layer and the charge transport layer is provided on the substrate having the conductive layer.

As the substrate having a conductive layer, if the substrate itself has conductivity, for example, aluminum, aluminum alloy,
Copper, zinc, stainless steel, vanadium molybdenum, chromium, titanium, nickel, indium, gold, platinum and the like can be mentioned. In addition, aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. can be vacuum-deposited. A plastic having a layer coated by (eg polyethylene, polypropylene,
Polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyfluoroethylene, etc.), conductive particles (for example, carbon black, silver particles, etc.) coated on a plastic with a suitable binder, conductive particles contained in plastic or paper. Examples include a corroded substrate and a plastic having a conductive polymer.

An undercoat layer having a barrier function and an adhesive function can be provided between the conductive layer and the photosensitive layer.

The subbing layer is made of 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 be formed.

The thickness of the undercoat layer is 0.1 to 5 µ, preferably 0.5 to 3 µ.
The range is appropriate.

When a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order is used, the substituted amino compound of the present invention is
Since it has a hole-transporting property, it is necessary to negatively charge the surface of the charge-transporting layer.When exposed after charging, holes generated in the charge-generating layer are injected into the charge-transporting layer in the exposed area, and then reach the surface and become negative. The charge is neutralized, the surface potential is attenuated, and an electrostatic contrast is generated between the surface and the unexposed portion. It is necessary to use positively charged toner at the time of development.

In another embodiment of the present invention, disazo pigments or U.S. Pat.Nos. 3,554,745, 3,567,438, and 3,586.
It is also possible to use a pigment or dye having photoconductivity such as pyrylium dye, thiapyrylium dye, serenapyrylium dye, benzopyrylium dye, benzothiapyrylium dye, or naphthopyrylium dye disclosed in 500 specifications as a sensitizer. it can.

In another embodiment, 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, halogenated 4- [4-bis- (2-chloroethyl) aminophenyl] -2,6-diphenylthiapyrylium perchlorate and poly (4,4'-isopropylidenediphenylene carbonate). Hydrocarbon solvent (for example, dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,
After dissolving in 2-trichloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene), this is dissolved in a non-polar solvent (eg hexane, octane, decane, 2,2,4
-It is obtained as a particulate eutectic complex by adding trimethylbenzene and ligroin. The electrophotographic photoreceptor in this embodiment 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 and the like can be contained as a binder.

The electrophotographic photosensitive member of the present invention is not only used in an electrophotographic copying machine, but also widely used in electrophotographic application fields such as a laser printer, a CRT printer, and an electrophotographic plate making system.

[Example] 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 then filtered and purified 7 g of pigment, product name Polyester Adhesive 49000 (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 on an aluminum sheet with a Meyer bar so that the dry film thickness was 0.5 μm, to form a charge generation layer.

Next, 7 g of the substituted diamino compound of the above compound example (5) as a charge transport substance and a polycarbonate (trade name: Panlite K)
-1300, Teijin Ltd. 7g and tetrahydrofuran 35g
A solution obtained by stirring and dissolving in a mixed solvent of 35 g of chlorobenzene and chlorobenzene was applied on the above charge generation layer with a Meyer bar so that the dry film thickness was 11 μ, and a photosensitive layer having a two-layer structure was formed. An electrophotographic photoreceptor having the above was prepared.

This electrophotographic photosensitive member was corona-charged at -5 KV by a static method using an electrostatic copying paper tester Model-SP-428 manufactured by Kawaguchi Electric Co., Ltd., held for 1 second in a dark place, and then exposed at an illuminance of 2.5 lux. Then, the charging characteristics were measured.

The charging characteristics are as follows: the surface potential (V ₀ ) and the exposure amount (E1 / E1) required to attenuate the potential (V ₁ ) when dark decaying for 1 second to 1/2.
2) was measured.

Furthermore, in order to measure the fluctuations in the light potential and the dark potential when the electrophotographic photosensitive member prepared above was repeatedly used, it was attached to a cylinder for a photosensitive drum of a PPC copier, product name NP-150Z, manufactured by Canon Inc. Then, the same machine was used to make 50,000 copies, and the changes in the light potential (V _L ) and the dark potential (V _D ) at the initial stage and after 50,000 copies were measured.

Further, instead of the compound of the substituted amino compound example (5), Comparative sample 1 using the compound of
Was prepared and the same measurement was performed.

The results are shown below.

From the above, it was confirmed that the electrophotographic photosensitive member of the present invention is significantly superior to the comparative sample in both sensitivity and potential stability.

Examples 2-18 In this example, instead of the charge transport material used in Example 1, substituted diamino compound examples (1), (2),
(3), (8), (9), (12), (13), (15),
(21), (25), (31), (35), (41), (44),
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the compounds of (59), (62) and (79) were used and the pigment of the example (44) was used as the charge generating substance.

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

Example 19 An aqueous ammonia solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 ml of water) was applied onto an aluminum cylinder by a dip coating method, and dried to apply a coating amount of 1.0 g / m ^2.
An undercoat layer was formed.

Next, 1 part by weight of the pigment of (78) exemplified as the charge generating substance,
1 part by weight of butyral resin (trade name: S-REC BM-2, manufactured by Sekisui Chemical Co., Ltd.) and 30 parts by weight of isopropyl alcohol were dispersed in a ball mill for 4 hours. This dispersion was applied onto the above-mentioned undercoat layer by a dip coating method and dried to form a charge generation layer. This film thickness was 0.3 μm.

Next, 1 part by weight of the charge transport material of the substituted diamino compound example (4), 1 part by weight of polysulfone (P-1700, manufactured by UCC),
6 parts by weight of chlorobenzene were mixed and stirred with a stirrer to dissolve. This liquid was applied onto the above charge generation layer by a dip coating method and dried to form a charge transport layer. The film thickness is
It was 12μ.

Corrosion discharge of −5 KV was applied to the photoreceptor thus prepared.

The surface potential (initial potential V ₀ ) at this time was measured. Further, the surface potential of this photoreceptor was measured after leaving it in the dark for 5 seconds.

The sensitivity was evaluated by measuring the exposure dose (E1 / 2 μJ / cm ² ) required to attenuate the potential Vk after dark decay to 1/2. At this time, a ternary semiconductor laser of gallium / aluminum / arsenic as the light source (output 5 mW, oscillation wavelength 780 nm)
Was used. The results are shown below.

V ₀ : −550V Potential holding ratio (Vk / V ₀ × 100): 94% E1 / 2: 1.3μJ / cm ² Laser beam, which is an electrophotographic printer of the reverse development type equipped with a semiconductor laser A photoconductor of a printer (LBP-LX, manufactured by Canon Inc.) was used by replacing the photoconductor of the present invention with the photoconductor of the present invention, and an actual image forming test was carried out under the following conditions.

Surface potential after primary charging: -700V, Surface potential after image exposure:
-150V (exposure amount 1.2μJ / cm ² ), transfer potential: + 700V, developer polarity: negative polarity, process speed: 50mm / sec, development condition (development bias): -450V, image exposure scan method: image scan, primary Pre-charge exposure: Full red exposure of 50 lux, sec.

Image formation was performed by laser scanning with a laser beam according to a character signal and an image signal, and good prints were obtained for both characters and images.

Example 20 3 g of 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate and 5 g of the substance of the substituted diamino compound example (39) were used as polyester (same as above).
100 ml of a toluene-dioxane (50:50) solution of
Disperse in a ball mill for 6 hours. This dispersion was applied onto an aluminum sheet with a Meyer bar so that the film thickness after drying was 15 μm.

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

V ₀ : -700V, V ₁ : -675V E1 / 2: 3.3lux, sec Initial V _D : -690V, V _L : -140V After endurance of 50,000 sheets V _D : -650V, V _L : -190V Example 21 Aqueous ammonia solution of casein (casein-1
1.2 g, 28% ammonia water 1 g, water 222 ml) was applied and dried with a Meyer bar to form an adhesive layer having a film thickness of 1 μm.

Next, disperse 5g of disazo pigment of charge generation substance example (16) and 2g of butyral resin (butyralization degree 63%) in a solution of 95ml of ethanol, and then coat it on the adhesive layer and dry it. A charge generation layer having a thickness of 0.4 μm was formed.

Next, a liquid prepared by dissolving 5 g of the substance of the substituted diamino compound example (76) and 5 g of poly-4,4'dioxydiphenyl-2,2-propane carbonate (viscosity average molecular weight 30,000) in 150 ml of dichloromethane was used as a charge generation layer. An electrophotographic photosensitive member was prepared by coating and drying the above, and forming a charge transport layer having a film thickness of 11 μm.

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

V ₀ : −600V, V ₁ : −580V E1 / 2: 2.6lux, sec Initial V _D : −585V, V _L : −115V After endurance of 50,000 sheets V _D : −550V, V _L : −160V Example 22 A 0.2 mm thick molybdenum plate (substrate) whose surface was cleaned was fixed at a predetermined position in the glow discharge 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 and the main valve of the evaporation tank were adjusted to stabilize at 0.5 torr. 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 substrate and the film thickness is 2μ.
After maintaining the same conditions until, the glow discharge was stopped.
After that, turn off the heater and high-frequency power supply, wait for the substrate temperature to reach 100 ° C, close the outflow valves for hydrogen gas and silane gas, temporarily lower the pressure to 10 ^-5 torr or less, then return to atmospheric pressure and take out the substrate. It was

Next, a charge transport layer was formed on the amorphous silicon layer in the same manner as in Example 1 except that the compound of Compound Example (11) was used as the charge transport substance.

Install the photoconductor thus created in the charging exposure experiment device,
It was 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, by cascading positively charged developer (including toner and carrier) onto the surface of the photoreceptor,
A good toner image was obtained on the surface of the photoconductor.

Example 23 4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate 3 g and poly (4,4'-isopropylidene diphenylene carbonate) 3 g were sufficiently dissolved in 200 ml of dichloromethane, 100 ml of toluene was added to precipitate the eutectic complex. After filtering this precipitate off,
Dichloromethane was added to redissolve it and then n
-Hexane 100 ml was added to obtain a eutectic complex precipitate.

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.

Next, examples of substituted diamino compounds that are charge transport materials (17)
A charge transport layer was formed on the above charge generation layer in the same manner as in Example 1 except that the above substances were used.

The electrophotographic characteristics of the thus prepared photoconductor were measured by the same method as in Example 1.

The results are shown below.

V ₀ : −650V, V ₁ : −635V E1 / 2: 1.8lux, sec Initial V _D : −655V, V _L : −90V After endurance of 50,000 sheets V _D : −625V, V _L : −150V Example 24 5 g of the same eutectic complex used in Example 23 and 5 g of the substance of the above substituted diamino compound example (24) were added to 150 ml of a tetrahydrofuran solution of polyester (the same as the above), and they were sufficiently mixed and stirred.

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 photoreceptor were measured in the same manner as in Example 1. The results are shown.

V ₀ : −680V, V ₁ : −670V E1 / 2: 2.2lux, sec Initial V _D : −660V, V _L : −110V After 50,000 sheets endurance V _D : −630V, V _L : −150V [Invention Effect] The electrophotographic photoreceptor of the present invention has high sensitivity and high durability (remarkably little potential fluctuation due to repeated use) by using a specific substituted diamino compound as a charge transport material.
In addition, it has a remarkable effect that it can be applied to a wide range of electrophotographic fields.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideyuki Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Masashige Umehara 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-Incorporated (56) Reference JP-A-55-79450 (JP, A)

Claims (2)

[Claims] 1. An electrophotographic photoreceptor having a layer containing a substituted diamino compound represented by the following general formula. General formula In the formula, A represents a divalent aromatic ring group or a divalent heterocyclic group which may have a substituent, and R ₁ and R ₂ each represent an alkyl group, an aralkyl group or an aryl which may have a substituent. A group or a heterocyclic group, or R ₁ and R ₂ represent a residue forming a heterocycle with a nitrogen atom, R ₃ , R ₄ , and R ₅ are hydrogen atoms, alkyl groups,
It represents an alkoxy group, an aralkyl group, an aryl group, a halogen atom, a nitro group, a cyano group, a hydroxyl group or an acyl group. 2. The electrophotographic photosensitive member according to claim 1, wherein A in the general formula is a phenylene group.