JPS6313049A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having excellent characteristics by using a diphenyl triazole compd. contg. an alkyl group, aralkyl group, ally group or heterocyclic group. CONSTITUTION:The diphenyl triazole compd. having the structure expressed by the general formula and polaymide, etc., as a binder are compounded and are dissolved in a solvent such as methanol. The soln. is coated on an electric charge transfer layer consisting of amorphous Si, etc., and is dried. The photosensitive body constituted in the above-mentioned manner is less fluctuated in bright and dark parts at the time of respective use. In the formula, R1-R3 are a methyl group, benzyl pyridyl group, etc., and Ar1, Ar2 are a phenyl group, pyridyl group, etc. These groups may have a substituent such as halogen atom, alkoxy group and nitro group.

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] Inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are conventionally known as photoconductive materials used in electrophotographic photoreceptors. These photoconductive materials have many advantages, such as being able to be charged to an appropriate potential in the dark, having little charge dissipation in the dark, or being able to rapidly dissipate charge when irradiated with light. 0 For example, selenium-based photoreceptors easily crystallize due to factors such as temperature, humidity, dust, and pressure. Especially when the ambient temperature exceeds 40°C, crystallization becomes significant and the electrostatic charge increases. There are disadvantages such as reduced quality and spots in the image. Cadmium sulfide photoreceptors do not provide stable sensitivity in humid environments, and zinc oxide photoreceptors require the sensitizing effect of sensitizing dyes such as rose bengal.
Such sensitizing dyes suffer from charge deterioration due to corona charging and discoloration due to exposure light, and therefore have the disadvantage that they cannot provide stable images over a long period of time.

On the other hand, various organic photoconductive polymers including polyvinylcarbazole have been proposed, but these polymers are superior to the aforementioned inorganic photoconductive materials in terms of film formability and light weight. However, it has been difficult to put it into practical use to date because sufficient film formation properties have not yet been achieved, and inorganic photoconductors have been lacking in sensitivity, durability, and stability against environmental changes. This was because the material was inferior. Also, hydrazone compounds disclosed in US Pat. No. 4,150,987, triarylpyrazoline compounds described in US Pat. No. 3,837,851, JP-A-51-94828, JP-A-51-94829, etc. Low-molecular organic photoconductors have been proposed, such as the 9-styrylanthracene compound described in . By appropriately selecting the binder used, such low-molecular-weight organic photoconductors can overcome the drawbacks of film-forming properties that had been a problem in the field of organic photoconductive polymers. It is not sufficiently sensitive.

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. An electrophotographic photoreceptor with this end layer structure as a photosensitive layer has excellent sensitivity to visible light and charge retention ability.

It has become possible to improve aspects such as surface strength.

Such an electrophotographic photoreceptor is disclosed in, for example, US Pat. No. 383
It is disclosed in US Pat. No. 7,851, US Pat. No. 3,871,882, and the like.

However, the sensitivity and characteristics of conventional electrophotographic photoreceptors using low-molecular organic photoconductors in the charge transport layer are not necessarily sufficient, especially when repeated charging and exposure are performed. There are large fluctuations and there are areas that need improvement.

[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 further to provide a charge generating layer and a charge generating layer. An object of the present invention is to provide a novel charge transport material in a laminated photosensitive layer which is functionally separated from the charge transport layer.

[Means for Solving Problems, Effects] The present invention comprises an electrophotographic photoreceptor characterized by having a diphenyltriazole compound represented by the following general formula.

In the general formula, R,, R2 and R3 represent an alkyl group, an aralkyl group, an aryl group or a heterocyclic group which may have a substituent, and Ar1 and Ar2 represent an aryl group or a heterocyclic group which may have a substituent. Represents a heterocyclic group.

Specifically, R,, R2 and R3 are methyl, ethyl,
Represents an alkyl group such as propyl and butyl, a heptaralkyl group such as benzyl and phenethyl, a phenyl group such as phenyl and naphthyl, a heterocyclic group such as pyridyl, quinolyl, furyl 5thinyl, oxasilyl, thiazolyl, imidazolyl and carbazolyl, Arl and Ar2 are R,
, R2 and R3 represent groups similar to the phenyl group and heterocyclic group listed, and further substituents that R1, R2, R3゜Ar1 and Ar2 may have include a chlorine atom,
Examples include halogen atoms such as bromine and iodine atoms, alkyl groups such as methyl, ethyl, and propyl, alkoxy groups such as methoxy, ethoxy, and propoxy, nitro groups, and cyano groups. Further, Ar1 and Ar2 may be the same or different, and compounds in which R1 is a phenyl group are particularly preferred.

As a diphenyltriazole compound, especially open/close 5
Compounds described in JP-A No. 5-64242 and JP-A No. 57-90633 have been proposed, but as a result of studying the substituents on the phenyl group, the present inventors found that an aryl-substituted amine group or a heterocyclic-substituted amino The present invention was achieved by discovering that compounds into which groups have been introduced have particularly excellent electrophotographic properties.

Representative examples of the diphenyltriazole compounds represented by the above general formula in the present invention are shown below.

-Hr Hx Hz CλHs- c, H.

Hx a Hg Ck Although typical examples of diphenyltriazole compounds represented by the general formula are listed above, the compounds of the present invention are not limited to these.

The diphenyltriazole compound represented by the above general formula of the present invention is.

general formula (In the formula, R1 has the same meaning as above) The diamine represented by R2, R3, and Arl.

It is synthesized by Uhlmann reaction using a compound corresponding to Ar2, but when introducing different substituents on the left and right sides, after partially reducing the dinitro form which is the first stage of the diamine represented by the above general formula and introducing the desired group. , requires measures such as reduction again and introduction of another group.

The method for synthesizing diphenyltriazole compound example (8) will be described below as a typical synthesis example.

曾c2)! , -, 2.5 g of Cu, and 12.4 g (89-7 mmol) of potassium carbonate were added to 100 mJl of iodoben9, heated under reflux for 10 hours, and then the reaction solution was diluted with the usual The residue was worked up by the method and purified by recrystallization using DMF to obtain 15.9 g of the target compound. The yield was 68%.

Elemental analysis value Calculated value (%) Actual value (%) (:
85.84 85.80H6,266,27 N 7.90 7.93 In a preferred embodiment of the present invention, the above general charge transport material is added to the electrophotographic photoreceptor in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer. A diphenyltriazole compound represented by the formula can be used.

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

Examples of the binder include polyarylate, polysulfone, polyamide, acrylic resin, acrylonitrile resin,
Methacrylic resin, polyvinyl chloride, polyvinyl acetate, phenolic resin, epoxy resin, polyester, alkyd resin, polycarbonate, polyurethane, or a copolymer containing two or more of the flip units of these resins, such as styrene-butadiene copolymer, styrene -acrylonitrile copolymer, styrene-maleic acid copolymer, etc. In addition to such insulating resins, organic photoconductive polymers such as polyvinylcarbazole, polyvinylanthracene, and polyvinylpyrene can also be used.

The blending ratio of the binder and the diphenyltriazole compound 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 underlying charge generation layer, and has the function of receiving and taking charge carriers injected from the charge generation layer in the presence of an electric field and transporting these charge carriers to the surface. have. At this time, the charge transport layer may be laminated on or below the charge generation layer, but it is preferable that the charge transport layer is laminated on the charge generation layer. .

Since the charge transport layer has a limit in its ability to transport charge carriers, it cannot be made thicker than necessary. Generally, the thickness is 5 to 30 μL, but the preferred range is 8 to 20 μL.

The solvent used to form the 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 undercoat layer.

For example, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexane, and N.

Amides such as N-dimethylformamide and N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, and 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, trichlorethylene, benzene, toluene, Aromatic hydrocarbons such as xylene, ligroin, 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-Par coating method, a blade coach ink method, a roller coating method, or a curtain coating method.

For drying, a method of drying to the touch at room temperature and then heating drying is preferred. Heat drying at 30-200"c for 5 minutes to 2
It can be carried out stationary or under ventilation for a range of hours.

The charge transport layer can contain various additives. Such additives include diphenyl.

Diphenyl chloride, 0-terphenyl, p-terphenyl, dibutyl phthalate, dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene, hensifhenone, chlorinated paraffin, dilaurylthiopropionate, 3.5-dinitrosalicylic acid , various fluorocarbons, and the like.

The charge generating layer in the present invention includes selenium, selenium-tellurium, biryllium dyes, thiapyrylium dyes, azulenium dyes, phthalocyanine pigments, anthanthrone pigments, dibenzpyrenequinone pigments, pyraftron pigments, trisazo pigments, disazo pigments, monoazo pigments, and indigo pigments. pigment,
Quinacridone pigment, thiacyanin, asymmetric quinocyanin, quinocyanin, etc. or JP-A-143645-1985
It can be formed as a vapor deposited layer or a resin dispersed layer using a charge generating substance such as amorphous silicon described in the above publication.

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

Charge generating substance (1) Amorphous silicon (2) Selenium-tellurium (3) Selenium-arsenic (4) Cadmium sulfide (f3) (3 days) (4θ)
CyuH1CyuHz,
CyuH5 (5B) O (58) Squaric acid methine dye (59)
Indigo dye (60) Thioindigo dye (81) β-type copper phthalocyanine (B4) (B5) (8B) The charge generation layer is prepared by dispersing the above charge generation substance in a suitable binder and dispersing it on the substrate. It can be formed by coating, or it can also be obtained by forming a vapor deposited film using a vacuum evaporation 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
It can be selected from organic photoconductive polymers such as N-vinylcarbazole, polyvinylanthracene and polyvinylpyrene.

Preferably, polyvinyl butyral, polyarylate (
polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide, polyvinylpyridine, cellulose resin, polyurethane, casein, polyvinyl alcohol, polyvinylpyrroli, ton, etc. The following insulating resins can be mentioned.

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, and isopropanol, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone, amides such as N,N-dimethylformamide and 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, trichlorethylene, benzene, toluene, xylene, Examples include aromatic hydrocarbons such as ligroin, monochlorobenzene, and dichlorobenzene.

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

The charge generation layer contains as much of the charge generation substance as possible to obtain sufficient absorbance, and in order to shorten the range of the generated charge carriers, the charge generation layer is a thin film layer, for example, 5 tons or less, preferably 0. A thin film layer having a film thickness of .01 to 1 ml is preferred.

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

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

Examples of the substrate having a conductive layer include aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium molybdenum, chromium,
Examples include titanium, nickel, indium, gold, platinum, etc. Other examples include plastics (e.g. polyethylene, Polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin,
(polyfluorinated ethylene, etc.), substrates made of plastic coated with conductive particles (e.g. carbon black, silver particles, etc.) together with a suitable binder, substrates made of plastic or paper impregnated with conductive particles, plastics containing conductive polymers, etc. can be mentioned.

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

The undercoat layer is made of casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, etc.).

Nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, aluminum oxide, etc.

The thickness of the undercoat layer is 0.1 to 5 mm, preferably 0.5 mm.
A range of 3 to 3 is suitable.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, the diphenyltriazole compound of the present invention has hole transport properties, so the surface of the charge transport layer must be negatively charged. , when exposed to light 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 charge, resulting in attenuation of the surface potential and a gap between the exposed area and the unexposed area. Electrostatic contrast occurs. It is necessary to use positively charged toner during development.

In another embodiment of the present invention, disazo pigments or pyrylium dyes, thiapyrylium dyes, selenapyrylium dyes, and benzopyrylium dyes disclosed in U.S. Pat. lium dye, benzothiapyrylium dye,
Photoconductive pigments and dyes such as naphtopyrylium dyes can also be used as sensitizers.

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

This eutectic complex includes, for example, 4-[4-bis-(2-chloroethyl)aminophenyl]-2,6-cyphenylthiapyrylium perchlorate and poly(4,4°-impropylidene diphenylene carbonate). Halogenated hydrocarbon solvents (e.g. dichloromethane, chloroform, carbon tetrachloride, 1.1-dichloroethane, 1.2-dichloroethane, 1.1.2-trichloroethane, chlorobenzene, bromobenzene, 1,2-dichlorobenzene) A particulate eutectic complex is obtained by adding a non-polar solvent (for example, hexane, octane, decane, 2,2.4-)limethylbenzene, ligroin).

The electrophotographic photoreceptor in this specific example includes styrene-butadiene copolymer, silicone resin, vinyl resin, vinylidene chloride-acrylonitrile copolymer, styrene-7crylonitrile copolymer, vinyl acetate-vinyl chloride copolymer, polyvinyl butyral, polymethyl methacrylate. , poly-N-butyl methacrylate,
Polyesters, cellulose esters, etc. can be contained as a binder.

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

[Example] Example 1 β-type copper phthalocyanine (LW product name L io no
IBlue NCB Toner (manufactured by Sokusho Ink Manufacturing ■) was sequentially refluxed in water, ethanol and benzene, and purified by filtration. 7 g of pigment, trade name: Polyester Adhesive 49000 (solid content 20%, manufactured by DuPont)
14g, toluene 35g, and dioxane 35g were mixed,
A coating solution was prepared by dispersing in a ball mill over time. This coating liquid was applied onto an aluminum sheet using a Meyer bar to a dry film thickness of 0.5 JL to form a charge generation layer.

Next, as a charge transport material, 7 g of the diphenyltriazole compound of Compound Example (1) and 7 g of polycarbonate (trade name Panrai K-1300, manufactured by Teijin Ltd.) were stirred and dissolved in a mixed solvent of 35 g of tetrahydrofuran and 35 g of chlorobenzene. Place the obtained solution on top of the previous charge generation layer.
An electrophotographic photoreceptor having a photosensitive layer having a two-layer structure was prepared by coating with a Meyer bar to a dry film thickness of 1 IJL. This electrophotographic photoreceptor was statically charged with corona at 15 KV using an electrostatic copying paper tester Model 5P-428 manufactured by Kawaguchi Denki ■, and after being held in a dark place for 1 second, the illuminance was set to 2. It was exposed to light at 5uux and the charging characteristics were measured.

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

Furthermore, in order to measure the fluctuations in bright area potential and dark area potential when the electrophotographic photoreceptor prepared above is repeatedly used, it was pasted on the photosensitive drum cylinder of a PPC copier (trade name: NP-1502, manufactured by Canon ■). , so, ooo on the same plane
Copies were made, and changes in bright area potential (VL) and dark area potential (Vo) were measured at the initial stage and after 50,000 copies were made.

Further, Comparative Materials 1 and 2 were prepared in the same manner except that Comparative Compounds 1 and 2 having the following structures were used in place of the compound in Exemplified Compound Example (1), and the same measurements were performed.

Comparative compound I C.H.

Comparative compound 2 H, c, N CzHr The results are shown below.

VO(-V)Vl (-V)El/2 (!uz, 5e
c) Example 1 710 690 4.1 Comparative sample 1
700 675 10.3 Comparison material 2 705 6
80 7.5 Initial 50,000 sheets Durability Example I Vo(-V) 705 670VL(-V
) 180 220 Comparative sample I Vo(-V) 710 630VL
(-V) 220 380 Comparison material 2 Vo(-V)695 650VL(-
V) 200 320 As is clear from the above results, the above of the present invention.

Electrophotographic photoreceptors using diphenyltriazole-based compounds have superior sensitivity characteristics and potential stability compared to electrophotographic photoreceptors using comparative compounds.

Examples 2 to 25 In this example, diphenyltriazole-based compound examples (2
Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that the compounds of ) to (25) were used and the azo pigment of example (5) was used as the charge generating substance.

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

2 (2) 705 690 4.43
(3) 695 685 5.84 (4
) 690 670 6.55 (5)
700 680 4.86 (6) 710
690 5.57 (7) 705 690
6.08 (8) 700 685 4.
59 (9) 695 690 7.010
(10) 710 690 3.011 (
11) 705 685 2.812 (12
) 705 680 3.713 (13)
700 680 3.614 (14) 6
90 680 4.015 (15) 685
670 3.216 (16) 705 68
5 3.017 (17) 700 690 3
．． 318 (18) 705 685 3.61
9 (19) 700 680 3.
820 (20) 695 680
3.721 (21) 695 670
5.522 (22) 690 6
70 4.423 (23) 705
685 7.824 (24) 710
8g5 2.525 (25) 70
0 680 2.8 Initial After 50,000 sheets 7 700 180 R80225 From the above results, 1. The electrophotographic photoreceptor using the diphenyltriazole compound represented by the general formula of the present invention has a high sensitivity and potential change during long-term use. It can be seen that it is small and has excellent characteristics. In particular, when R1 is a phenyl group (which may have a substituent), it is confirmed that more excellent properties are exhibited.

Example 26 An ammonia aqueous solution of casein (11.2 g of casein, 1 g of 28% ammonia water, 222 mJL of water) was coated on an aluminum cylinder by dip coating and dried to form a subbing layer with a coating amount of 1.0 g and 7 m2. did.

Next, 1 part by weight of Pigment (82) as a charge generating substance, 1 part by weight of butyral resin (trade name Kosuretsuku BM-2, manufactured by Tsukushiki Kagaku ■) and 30 parts by weight of isopropyl alcohol were dispersed in a ball mill for 4 hours. This dispersion was applied onto the previous subbing layer by a dip coating method and dried to form a charge generating layer. This film thickness was 0.31L.

Next, the diphenyltriazole compound example (11)
1 part by weight of charge transport material, polysulfone (P-1700
, manufactured by UCC Corporation) and 6 parts by weight of monochlorobenzene were mixed and stirred with a stirrer to dissolve. This liquid is applied onto the previous charge generation layer using a dip coating method, dried, and then
A charge transporting region was formed. The film thickness was 12JL.

A corona discharge of 15 KV was applied to the photoreceptor thus prepared.

The surface potential (initial potential Vo) at this time was measured. Furthermore, the surface potential of this photoreceptor was measured after it was left in a dark place for 5 seconds (attenuation).

Sensitivity is the exposure amount (E 1/2 p, J/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 780 nm).
) was used. Show the results.

Vony 680V Potential holding rate (VK/VOX100): 92%E 1
/ 2: 2, Og J / cm Second, the photoreceptor of a laser beam printer (trade name: LBP-LX, manufactured by Canon Hook), which is a reversal development type electrophotographic printer equipped with the same semiconductor laser as above, is used in the present invention. The photoreceptor was replaced and set, and an actual image forming test was conducted under the conditions shown below.

Surface potential knee after primary charging 700V, surface potential knee after image exposure 150V (exposure amount 1.21LJ/cm2), transfer potential: +700V, developer polarity: negative polarity, process speed: 50mm/sec, development conditions (development Bias) knee 450V, image exposure scan method: image scan, -exposure before next charging: 50 Qux, red full-surface exposure for sec.

Image formation was performed by line scanning a laser beam in accordance with character signals and image signals.

Good prints of both text and images were obtained.

Example 27 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiapyrylium perchlorate and 5 g of the substance of diphenyltriazole compound example (3) were added to polyester (same as above) in toluene-dioxane. (50:5
0) The solution was mixed with 100 mJ1 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 drying was 151 L.

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

vo knee 690V, Vl knee 680VEl/2:
5.21ux, sec Initial Vo knee 695V, VL knee 200V After 50,000 sheets durability Vo knee 680V, VL knee 235V Example 28 Casein ammonia aqueous solution (casein 1
1.2g, 28% ammonia water 1g, water 222 mJL
) was coated with a Mayer bar and dried to form an adhesive layer with a thickness of 1p.

Next, 5 g of the disazo pigment of charge generating substance example (16) and 2 g of butyral resin (butyralization degree 63%) were dispersed together with a solution dissolved in 95 mJL of ethanol, and then coated on the adhesive layer, and the film thickness after drying was A charge generation layer was formed in which the charge was 0.41L.

Next, the diphenyltriazole compound example (17)
5g of substance and poly-4,4°dioxydiphenyl-2,
2-7' Lovan carbonate (viscosity average molecular weight 30,000) 5
An electrophotographic photoreceptor was prepared by dissolving 1.g in 150 ml of dichloromethane and coating the charge generating layer and drying it to form a charge transport layer having a thickness of 11 ml.

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

vo knee 710V, Vl knee 690Vel/2
: 2, IJlux, sec initial VD knee 700V, VL knee 190V after 50,000 sheets durability Vo knee 695V, VL knee 210V Example 29 A 0.2 mm thick molybdenum plate (substrate) with a cleaned surface was placed in a glow discharge deposition tank. The inside of the zero-order tank, which was fixed at a predetermined position, was evacuated to a vacuum level of about 5×10 −6 torr. Thereafter, 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 5MHz high-frequency power was applied to the zero-order induction coil, which was stabilized at 0.5 torr by adjusting the gas flow rate and the main valve of the deposition tank. A glow discharge is generated inside the coil inside the tank and the power is 30W.
The input power was set to . An amorphous silicon film was grown on the substrate under the above conditions, and after the same conditions were maintained until the film thickness reached 21L, glow discharge was stopped. After that, turn off the heater and high frequency power supply, wait until the substrate temperature reaches 100℃, close the hydrogen gas and silane gas outflow valves,
Once the pressure inside the tank was lowered to 10 torr or less, the pressure was returned to atmospheric pressure and the substrate was taken out.

Next, a charge transport layer was formed on this amorphous silicon layer in the same manner as in Example 1 except that the diphenyltriazole compound example was used as a charge transport material.

The photoreceptor created in this way was installed in a charging exposure experiment equipment,
It was corona charged at -6 KV and immediately irradiated with a light image. The light image was illuminated through a transmission type test chart using a tungsten lamp light source.

Immediately thereafter, by cascading a positively charged developer (including toner and carrier) onto the photoreceptor surface,
A good toner image was obtained on the surface of the photoreceptor.

Example 30 3 g of 4-(4-dimethylaminophenyl)-2,6-cyphenylthiavirylium perchlorate and poly(4,4
'-isopropylidene diphenylene carbonate) 3g
200m of dichloromethane! ; After sufficiently dissolving in L, 100 mfL of toluene was added to precipitate the eutectic complex.

After filtering this precipitate, dichloromethane was added to redissolve it, and then 100 ml of n-hexane was added to this solution to obtain a precipitate of a eutectic complex.

5 g of this eutectic complex was added to 95 mu of a methanol solution containing 2 g of polyvinyl butyral and dispersed in a ball mill for 6 hours. After drying, this dispersion was coated on an aluminum plate having a casein layer using a Mayer bar so that the film thickness was 0.44, thereby forming a charge generation layer.

Next, a charge transport layer was formed on the charge generation layer in the same manner as in Example 1 except that the material of the diphenyltriazole compound example (6) as a charge transport material was used.

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

The results are shown below.

vo knee 705V, Vl knee 685Vel/2
: 2.5Jlux, sec Initial VD knee 700V, VL knee 210V after 50,000 sheets durability Vo: -680V, VL knee 235V
Example 31 5 g of a eutectic complex similar to the eutectic complex used in Example 30 and substance 5 of the diphenyltriazole compound example (15)
g of polyester (previously) in tetrahydrofuran solution 15
0 m and was thoroughly mixed and stirred. The film thickness after drying this liquid with a Mayer bar on an aluminum sheet was 15 mm.
It was applied so that it was smooth.

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

vo Knee 705V, V, Knee 695VEl/2:
3.01ux, sec Initial VD Knee 690V, VL Knee 205V After 50,000 sheets durability Vp Knee 680V, VL Knee 225V [Effects of the Invention] The electrophotographic photoreceptor of the present invention uses a specific diphenyltriazole compound as a charge transport material. When used, it has the remarkable effects of high sensitivity, high durability (potential fluctuations due to repeated use are extremely small), and can be applied to a wide range of fields of electrophotography.

Claims (2)

[Claims] (1) An electrophotographic photoreceptor characterized by having a layer containing a diphenyltriazole compound represented by the following general formula. General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ In the formula, R_1, R_2, and R_3 represent an alkyl group, an aralkyl group, an aryl group, or a heterocyclic group that may have a substituent, and Ar_1 and Ar_2 are substituents. represents an aryl group or a heterocyclic group which may have (2) The electrophotographic photoreceptor according to claim 1, wherein R_1 in the above general formula is a phenyl group which may have a substituent.