JPH0743918A - Electrophotographic photoreceptor - Google Patents

Abstract

PURPOSE:To provide an electrophotographic photoreceptor having high sensitivity and low residual potential, undergoing no change of these characteristics even after repeated use and excellent in durability. CONSTITUTION:This electrophotographic photoreceptor has a photosensitive layer contg. an electric charge transferring material represented by general formula I, II, III, etc., on the electric conductive substrate. In the formula I, R1 is alkyl, R2 is alkyl, alkoxy, etc., each of R3 and R4 is H, halogen, alkyl, etc., each of (n) and (m) is an integer of 0-2 and X is a single bond, O, S or SO2. In the formula II, R5 is alkyl, R6 is alkyl, alkoxy, etc., R7 is halogen, cyano, alkyl, etc., (o) is an integer of 0-2 and (p) is an integer of 1-2. In the formula III, each of R8 and R9 is H, halogen, alkyl, etc., R10 is alkyl or halogen, each of (q) and (r) is an integer of 0-2 and (s) is an integer of 1-2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photosensitive member for forming an electrostatic latent image. Specifically, it relates to an electrophotographic photoreceptor having a layer containing a compound having an electron transporting ability.

[0002]

2. Description of the Related Art Conventionally, selenium has been used as an electrophotographic photoreceptor.
Inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive compound such as zinc oxide, cadmium sulfide, or silicon as a main component have been widely used. But these are the sensitivity, thermal stability,
Moisture resistance, durability, etc. are not always satisfactory, and some inorganic photoconductors have problems in disposal because they contain substances harmful to the human body.

For the purpose of overcoming the drawbacks of these inorganic photoconductors, research and development of organic photoconductors having a photosensitive layer containing various organic photoconductive compounds as main components have been actively conducted in recent years. In particular, the function-separated type photoreceptor in which the carrier generation function and the carrier transport function are shared by different substances,
Since various materials can be selected from a wide range and a photoreceptor having arbitrary performance can be prepared relatively easily, many studies have been made, and some have been put to practical use. For example, US Pat. No. 3,871,882 uses a perylene derivative as a carrier generating layer and an oxadiazole derivative as a carrier transporting layer, and JP-A-55-84943 discloses that a carrier generating substance is a distyrylbenzene bisazo compound and a carrier transporting substance. Those using a hydrazone compound are known.

Compounds such as pyrazoline, hydrazone, and triphenylamine derivatives are known as substances having a carrier transporting function, and these are all substances having a hole transporting ability, and carrier generating substances. In the case of a function-separated type photoreceptor in which the layer containing C is a lower layer and the layer containing a carrier transporting material is an upper layer, it is necessary to adopt a method of negatively charging the surface of the photoreceptor. Therefore, it is impossible to use the developer conventionally used for the inorganic photoconductor. Further, there is a defect that the amount of ozone generated when the photoconductor is charged by corona discharge is larger than that during the positive charging performed by the inorganic photoconductor. In particular, the large amount of ozone generated is a problem not only in the deterioration of the photoconductor due to it but also in the influence on the human body and environment.

As the positive charging type photoreceptor using an organic photoreceptor, a photoreceptor having a reverse layer structure in which a conventional hole transport material is used and a carrier generation layer is an upper layer and a carrier transport layer is a lower layer,
A single-layer photoconductor containing a carrier-generating substance and a carrier-transporting substance in the same layer has been studied, but durability,
In terms of environmental characteristics, there is no product that has sufficient performance for high-speed machines.

Therefore, in order to solve the above problems, it is required to apply a substance having an electron transporting ability as a carrier transporting substance to the carrier transporting layer. 2,4,7-Trinitrofluorenone is known as such an electron-transporting substance, but this substance is not sufficiently soluble or compatible with a solvent or a polymer used as a binder, so that the actual photosensitive layer Does not have sufficient properties when constructing. Its use has been discontinued due to its carcinogenicity.

Others In recent years, several electron-transporting substances in which a soluble group is introduced into an electron-accepting structure have been proposed.
For example, Japanese Patent Laid-Open Nos. 1-206349, 2-135362, and 2-2148
66, JP-A-3-290666, "Japan Hard Copy '92" Proceedings, P1
73 (1992). However, in the current situation, none of the compounds has sufficient sensitivity and potential characteristics when combined with the existing carrier-generating substance, and has practical problems.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to use a carrier transporting material having an electron transporting ability with high sensitivity and a small residual potential, and even if it is repeatedly used, its characteristics are improved. An object of the present invention is to provide an electrophotographic photoreceptor having excellent durability that does not change.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a specific general formula (A
The inventors have found that the compounds represented by 1) to (D4) can be excellent active ingredients for electrophotographic photoreceptors, and completed the present invention. That is, the above-mentioned object of the present invention can be achieved by an electrophotographic photoreceptor having a photosensitive layer containing an electron-transporting substance represented by formulas (A1) to (D4) on a conductive support.

[0010]

[Chemical 5]

In the formulas (A1) and (A2), R ₁ represents a substituted or unsubstituted alkyl group, and R ₂ represents a substituted or unsubstituted alkyl group, alkoxy group or aryl group. R ₃ and R ₄ each independently represent hydrogen, halogen, a substituted or unsubstituted alkyl group and an alkoxy group, a nitro group, a cyano group, an alkoxycarbonyl group, an acyl group, and n and m.
Represents an integer of 0 to 2. X represents a single bond, O, S or SO ₂ .

The alkyl group represented by R ₁ or R ₂ is preferably an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, i-propyl, t-butyl and trifluoromethyl groups. . The alkoxy group of R ₂ is preferably an alkoxy group having 1 to 4 carbon atoms, and specific examples thereof include methoxy, ethoxy, n-propoxy, and n-butoxy groups. Specific examples of the aryl group of R ₂ include phenyl, toluyl, thienyl and pyridyl groups.

Specific examples of the halogen of R ₃ and R ₄ include Cl,
F, Br, I can be mentioned. Specific examples of the alkyl group of R ₃ and R ₄ include methyl, ethyl, i-propyl, t-butyl and trifluoromethyl groups.
Specific examples of the alkoxy group for R ₃ and R ₄ include methoxy, ethoxy, n-propoxy and n-butoxy groups. Specific examples of the alkoxycarbonyl group for R ₃ and R ₄ include lower to long-chain aliphatic ester groups such as ethoxycarbonyl, butoxycarbonyl, and octyloxycarbonyl. Specific examples of the acyl group of R ₃ and R ₄ include lower to long-chain aliphatic acyl groups such as acetyl, propionyl and lauroyl.

Particularly preferably, R ₁ and R ₂ are acetyl or trifluoroacetyl groups, and R ₃ and R ₄ are electron withdrawing groups such as nitro, cyano and trifluoromethyl.

[0015]

[Chemical 6]

In the formulas (B1) and (B2), R ₅ represents a substituted or unsubstituted alkyl group, R ₆ represents a substituted or unsubstituted alkyl group, an alkoxy group or an aryl group, and R ₇ is each independent. Represents a halogen, a cyano group, a substituted or unsubstituted alkyl group, an alkoxy group, and an aryl group. Further, o represents an integer of 0 to 2, and p represents an integer of 1 to 2.

The alkyl group represented by R ₅ or R ₆ is preferably an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, i-propyl, t-butyl and trifluoromethyl groups. . The alkoxy group represented by R ₆ is preferably an alkoxy group having 1 to 4 carbon atoms, and specific examples thereof include methoxy, ethoxy, n-propoxy and n-butoxy groups. Specific examples of the aryl group of R ₆ include phenyl, toluyl, thienyl and pyridyl groups.

Specific examples of the halogen of R ₇ include Cl, F and B.
r and I can be mentioned. Specific examples of the alkyl group of R ₇ include methyl, ethyl, i-propyl, t-butyl, trifluoromethyl group and the like. Specific examples of the alkoxy group for R ₇ include methoxy, ethoxy, n-propoxy and n-butoxy groups. Specific examples of the aryl group of R ₇ include phenyl, toluyl, thienyl and pyridyl groups.

Particularly preferably, R ₅ and R ₆ are acetyl or trifluoroacetyl, and R ₇ is a halogen, an alkyl group or a halogenated alkyl group.

[0020]

[Chemical 7]

In the formula (C), R ₈ and R ₉ each independently represent hydrogen, halogen, a substituted or unsubstituted alkyl group and an alkoxy group, a nitro group, a cyano group, an acyl group or an alkoxycarbonyl group, and R ₁₀ Represents a substituted or unsubstituted alkyl group or halogen. Q and r are integers from 0 to 2,
s represents an integer of 1-2.

Specific examples of the halogen of R ₈ and R ₉ include Cl,
F, Br, I can be mentioned. Specific examples of the alkyl group of R ₈ and R ₉ include methyl, ethyl, i-propyl, t-butyl, trifluoromethyl group and the like.
Specific examples of the alkoxy group for R ₈ and R ₉ include methoxy, ethoxy, n-propoxy and n-butoxy groups. Specific examples of the alkoxycarbonyl group for R ₈ and R ₉ include lower to long chain aliphatic ester groups such as ethoxycarbonyl, butoxycarbonyl, and octyloxycarbonyl. Specific examples of the acyl group of R ₈ and R ₉ include lower to long-chain aliphatic acyl groups such as acetyl, propionyl and lauroyl.

The substituted or unsubstituted alkyl group for R ₁₀ is preferably an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, i-propyl, t-butyl and trifluoromethyl groups. You can Specific examples of the halogen of R ₁₀ include Cl, F, Br and I.

Particularly, R ₈ and R ₉ are electron withdrawing groups such as nitro, cyano and trifluoromethyl, and R ₁₀ is more preferably an alkyl group substituted at the ortho position of the aniline ring or a halogenated alkyl group.

[0025]

[Chemical 8]

Equations (D1), (D2), (D3) and (D
In 4), each R ₁₁ is independently a halogen, a cyano group,
A substituted or unsubstituted alkyl group and alkoxy group, an aryl group, R ₁₂ represents a substituted or unsubstituted alkyl group,
Represents halogen. Further, x represents an integer of 0 to 2 and y represents an integer of 1 to 2.

Specific examples of the halogen of R ₁₁ include Cl, F,
Br and I can be mentioned. Specific examples of the alkyl group of R ₁₁ include methyl, ethyl, i-propyl, t-butyl, trifluoromethyl group and the like. R
Specific examples of the alkoxy group of ₁₁ include methoxy, ethoxy, n-propoxy, n-butoxy groups and the like. Specific examples of the aryl group of R ₁₁ include phenyl, toluyl, thienyl and pyridyl groups.

The substituted or unsubstituted alkyl group for R ₁₂ is preferably an alkyl group having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, i-propyl, t-butyl and trifluoromethyl groups. You can Specific examples of the halogen of R ₁₂ include Cl, F, Br and I.

More preferably, R ₁₁ is a halogen or an alkyl group or a halogenated alkyl group, and R ₁₂ is an alkyl group or a halogenated alkyl group substituted at the ortho position of the aniline ring.

The electron-transporting substance (A) of the present invention is converted into a corresponding gem-dihalide of a substituted benzophenone, fluorenone, or another aromatic ketone using phosphorus pentachloride or the like by a known method, and then condensed with acetylacetone, benzoylacetone, or the like. It can be synthesized by

(Synthesis Example 1) 4-trifluoromethylfluorenone (24.8 g; 0.1 mol), phosphorus pentachloride (22.8 g; 0.11 mol)
A mixture of l), 3 g of phosphorus oxychloride and 20 ml of toluene is heated and reacted on a water bath for about 3 hours with stirring. After the reaction, 200 ml of toluene was further added, washed with the same amount of pure water twice, and dried over anhydrous magnesium sulfate.

After the toluene was distilled off, the residue was recrystallized from glacial acetic acid to obtain 2,9-dichloro-4-trifluoromethylfluorene (21.8 g y.72%).

Next, acetylacetone (66.7) was added to a sodium ethylate / ethanol solution (Na 15.3 g / EtOH 300 ml).
g; 0.67 mol) is added. The 9,9-dichloro-4-trifluoromethylfluorene (1
00 g; 0.33 mol) is added dropwise over about 1 hour, and after the addition is complete, the mixture is refluxed for 2 hours. After cooling, carbon dioxide gas was blown in for about 10 minutes, the precipitate was filtered off, washed several times with ethanol and added to the filtrate. Crystals were precipitated when the ethanol layer was ice-cooled, and the crystals were collected by filtration and recrystallized from ethanol to obtain 32.0 g y.29% of Exemplified Compound A-17.

Synthesis Example 2 Hexafluoroacetylacetone (41.6 g; 0.2 mol) is added to a sodium ethylate / ethanol solution (Na 4.6 g / EtOH 100 ml). Benzophenone chloride (23.7g; 0.1mol) was added to this solution under heating and reflux.
Is added dropwise over about 1 hour, and after the addition is completed, the mixture is refluxed for 2 hours. After cooling, blow carbon dioxide for about 10 minutes,
The precipitate is filtered off, washed several times with ethanol and added to the filtrate. The entire ethanol layer was steam distilled to remove ethanol and excess acetylacetone, and the oily residue was purified by silica gel column chromatography to obtain 12.5 g y.21% of Exemplified Compound A-76.

Next, specific examples of the electron transporting substance of the present invention will be described, but the electron transporting substance of the present invention is not limited thereby.

[0036]

[Chemical 9]

[0037]

[Chemical 10]

[0038]

[Chemical 11]

[0039]

[Chemical 12]

[0040]

[Chemical 13]

[0041]

[Chemical 14]

The electron-transporting substance (B) of the present invention is prepared by reacting quinone and diphenoquinone derivatives with acetyl cetone or the like in the presence of a base or a nickel acetoacetate catalyst by a known method, and the resulting substituted hydroquinone derivative is silver oxide. It can be synthesized by oxidation in the presence of a catalyst such as.

(Synthesis Example 3) 2,6-dichloro-1,4-benzoquinone (3.6 g; 0.02 mol), acetylacetone (4.0 g; 0.04)
mol) and 0.2 g of Ni (acac) 2 are added to 60 ml of methanol, and the mixture is reacted overnight with stirring. After the reaction, the reaction solution was poured into about 250 ml of water, and the precipitated crystals were collected by filtration and recrystallized from ethanol / water to give 2,6-dichloro-3-diacetylmethyl-1,4-hydroquinone 4.2 gy.74%. obtain.

2,6-Dichloro-3-diacetylmethyl-1,4-hydroquinone (4.2 g; 0.015 mol) was suspended in 200 ml of methylene chloride, 0.9 g of silver oxide and 1.0 g of sodium sulfate were added, and the mixture was stirred at room temperature. Stir overnight. After the reaction, the reaction solution was filtered off, and the residue obtained by concentrating the filtrate was recrystallized from ethanol to obtain 3.4 g y.82% of Exemplified Compound B-1.

(Synthesis Example 4) Acetylacetone (4.4 g: 0.
044 mol) and benzyltrimethylammonium hydroxide (1 ml) were added to 25 ml of methanol, and the solution was stirred at room temperature with 2,5-dichloro-1,4-benzoquinone (3.5 g; 0.02 m).
ol) is added little by little. Crystals will precipitate after a while, so after stirring for 1 hour at room temperature, the crystals were collected by filtration and recrystallized from acetonitrile to give 2,5-dichloro-3,6-
Bis (diacetylmethyl) -1,4-hydroquinone 5.2g y.69
Earned%.

The synthesized 2,5-dichloro-3,6-bis (diacetylmethyl) -1,4-hydroquinone was oxidized with silver oxide in the same manner as in Synthesis Example 3, and Exemplified Compound B-6 3.9 g y.76% Got

Next, specific examples of the electron-transporting substance (B) of the present invention will be described, but the electron-transporting substance of the present invention is not limited thereto.

[0048]

[Chemical 15]

[0049]

[Chemical 16]

The electron-transporting substance (C) of the present invention can be synthesized by a known method by condensing an aromatic ketone such as substituted xanthone with a substituted aniline in the presence of a catalyst such as zinc chloride.

(Synthesis Example 5) 2,8-dinitroxanthone (2.8
6 g; 0.01 mol), O-toluidine (2.14 g; 0.02 mol) and 0.3 g of anhydrous zinc chloride are heated and reacted at 170 ° C. for 30 minutes.
Warm water is poured into the reaction residue, and organic matter is extracted with methylene chloride. The methylene chloride layer was dried over anhydrous magnesium sulfate, methylene chloride was removed, and the residue was purified by silica gel column chromatography to give Exemplified Compound C-2 2.0 g y.54%
Got

Next, specific examples of the electron-transporting substance (C) of the present invention will be described, but the electron-transporting substance of the present invention is not limited thereby.

[0053]

[Chemical 17]

[0054]

[Chemical 18]

[0055]

[Chemical 19]

The electron transporting substance (D) of the present invention can be synthesized by a known method by condensing a quinone or diphenoquinone derivative with a substituted aniline in the presence of a catalyst such as zinc chloride.

(Synthesis Example 6) 2,6-dichloro-1,4-benzoquinone (3.6 g; 0.02 mol), O-toluidine (3.21 g; 0.03 mo)
l) and 0.5 g of anhydrous zinc chloride are added to 30 ml of nitrobenzene,
Heat at about 170 ° C. for 2 hours to react. After the reaction, nitrobenzene is removed by steam distillation, and the remaining oily residue is extracted with methylene chloride. The methylene chloride layer was washed with water several times and finally dried over anhydrous magnesium sulfate, methylene chloride was removed, and the residue was purified by silica gel column chromatography to obtain 1.9 g y.35% of Exemplified Compound D-1. .

[0058]

[Chemical 20]

[0059]

[Chemical 21]

[0060]

The substance of the present invention has an excellent electron transporting property,
The electrophotographic photoreceptor of the present invention can be manufactured by providing a photosensitive layer, which is molecularly dispersed in a binder, on a conductive support. The electron-transporting substance of the present invention utilizes its excellent electron-transporting ability, and is used as a carrier-transporting substance. By using together with this a carrier-generating substance that can effectively act, a so-called function separation type It can be a photoreceptor. The function-separated type photoreceptor may be a photoreceptor having a mixed dispersion single layer structure of the both substances, but is a laminated type in which the carrier generation layer is the lower layer and the carrier transport layer made of the electron transporting material of the present invention is the upper layer It is more preferable to use a photoreceptor. Further, in a two-layer function-separated type photoreceptor, a photoreceptor in which the electron-transporting substance of the present invention is added to the carrier-generating layer and a carrier-generating substance is added to the carrier-transporting layer can be prepared. In any layer structure, an undercoat layer (intermediate layer) having a barrier function and adhesiveness may be provided between the support and the photosensitive layer, or a protective layer may be provided on the photosensitive layer. A charge transporting substance may be added to the protective layer, if necessary.

Next, a hole-transporting charge-transporting substance may be used in combination with the photoreceptor using the electron-transporting substance of the present invention. In that case, a layer structure in which the electron transporting substance of the present invention is added to the upper photosensitive layer and the hole transporting substance is added to the support side is preferable.

The electron-transporting layer may be formed by applying an electron-transporting substance of the present invention alone or in a suitable solvent dissolved and dispersed with a binder resin using an applicator, bar coater, dip coater or the like, and drying. it can.

Examples of the binder resin usable in the electron transport layer include polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin. , A polycarbonate resin, a silicone resin, a melamine resin, and a copolymer resin containing two or more of repeating units of these resins. In addition to these insulating resins,
Polymer organic semiconductors such as -N-vinylcarbazole may be mentioned. Examples of the dispersion medium of the electron transporting substance include hydrocarbons such as toluene and xylene; methylene chloride, 1,
Halogenated hydrocarbons such as 2-dichloroethane; ketones such as methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, propanol, butanol, methyl cellosolve, ethyl cellosolve and derivatives thereof Ethers such as tetrahydrofuran and 1,4-dioxane; amines such as pyridine and diethylamine; nitrogen compounds such as amides such as N, N-dimethylformamide; other fatty acids and phenols; carbon disulfide and triethyl phosphate One or more of sulfur and phosphorus compounds can be used.

The electron transporting material is preferably 20 to 200 parts by weight, and particularly preferably 30 to 150 parts by weight, per 100 parts by weight of the binder resin in the electron transporting layer. The thickness of the formed electron transport layer is preferably 5 to 30 μm. In the case of a single-layer function-separated electrophotographic photoreceptor, the ratio of binder: electron transport material: carrier generating material is 1 to 100: 1 to 500: 1 to 5
00 is preferable, and the thickness of the photosensitive layer to be formed is 5 to 50 μm. Next, the carrier generation layer is a carrier generation substance alone in a suitable solvent or together with a binder resin similar to that used in the above-mentioned electron transport layer. Dispersed dispersion is applied by dip coating, spray coating, blade coating, roll coating or the like on the support or the undercoat layer and then provided by a method of drying, or a carrier generating substance on the support or the undercoat layer. What was vapor-deposited is used. In the case of dispersion coating, the dispersion medium used in the dispersion of the electron transport material can be used as the solvent used. A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, or the like is used for dispersion.

Any known carrier-generating substance may be used, and examples thereof include selenium-based inorganic semiconductors, various phthalocyanine compounds, azo compounds,
Pyrylium compounds, perylene compounds, cyanine compounds, squarylium compounds, and polycyclic quinone compounds can be used.

When the photoreceptor of the present invention has a laminated structure, the weight ratio of the binder to the carrier generating substance in the carrier generating layer is 0 to 10: 1 to 50. The thickness of the carrier generation layer formed as described above is preferably 0.01 to 10 μm, particularly preferably 0.1 to 5 μm.

Next, as a conductive support for supporting the photosensitive layer, a metal plate / metal drum of aluminum, nickel or the like, a plastic film deposited with aluminum, tin oxide, indium oxide or the like, or a conductive substance is applied. Paper, plastic film and drum can be used.

In the photosensitive layer of the present invention, the following antioxidant may be added for the purpose of preventing ozone deterioration.

(1) Hindered phenols (2) Hindered amines (3) Paraphenylenediamines (4) Hydroquinones (5) Organophosphorus compounds These compounds prevent the oxidation of rubber, plastics, oils and fats, etc. It is known as an agent and commercially available products can be easily obtained.

Further, the photoreceptor of the present invention may further contain an ultraviolet absorber or a dye for color sensitivity correction for the purpose of protecting the photosensitive layer, if necessary.

[0071]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Examples 1 to 20 A 0.5 μm-thick intermediate layer made of polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) was provided on a PET film on which aluminum was vapor-deposited, and a perylene of the chemical formula (G-1) described later was formed thereon. 1 part pigment, polyvinyl butyral resin "ESREC BL
S "(manufactured by Sekisui Chemical Co., Ltd.) and 50 parts of methyl ethyl ketone as a dispersion medium were dispersed using a sand mill, and a liquid was applied using a wire bar to form a carrier generation layer having a thickness of 0.3 μm. Next, 1 part of the exemplified compound shown in Table 1 and 1.5 parts of a polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) were dissolved in 10 parts of tetrahydrofuran, and blade-coated on the charge generation layer to transport a carrier having a thickness of 20 μm. The layers were formed to prepare Example photoconductors 1 to 20.

[0073]

[Table 1]

Comparative Example 1 A comparative sample was prepared in the same manner as in Example 1 except that the comparative compound represented by the chemical formula (K-1) described below was used instead of the exemplified compound A-6.

[0075]

[Chemical formula 22]

Evaluation 1 The electrophotographic photosensitive member samples obtained in Examples 1-20 and Comparative Example 1 were charged to +800 V using an electrostatic copying tester EPA-8100 (manufactured by Kawaguchi Electric Co., Ltd.), and 10 lux white. The sensitivity was determined by exposing to light and determining the amount of exposure until the surface potential became half. The results are shown in Table 2.

[0077]

[Table 2]

Examples 21 to 30 A 0.5 μm-thick intermediate layer made of polyamide resin “X-1874M” (manufactured by Daicel Hüls) was provided on a PET film on which aluminum was vapor-deposited, and an X-type metal-free phthalocyanine was formed thereon. (Manufactured by Dainippon Ink and Chemicals, Inc.) 1 part, polyvinyl butyral resin "ESREC BX-1" (manufactured by Sekisui Chemical Co., Ltd.)
A solution in which 0.4 part and 50 parts of methyl isopropyl ketone as a dispersion medium were dispersed using a sand mill was applied using a wire bar to form a charge generation layer having a thickness of 0.3 μm. Next, 1 part of the exemplified compound of Table 3 and 1.5 parts of polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) were dissolved in 10 parts of tetrahydrofuran, and blade-coated on the carrier generation layer to form a charge transport layer having a thickness of 20 μm. To form an example photoconductor 21
~ 30 were made.

[0079]

[Table 3]

Comparative Example 2 A comparative sample was prepared in the same manner as in Example 21 except that the comparative compound represented by the chemical formula (K-2) was used instead of the exemplified compound A-5.

Evaluation 2 The electrophotographic photosensitive member samples obtained in Example 2 and Comparative Example 2 were evaluated by the following actual measurement values with an U-BIX1017 modified machine manufactured by Konica Corporation at the initial stage and after copying 10,000 sheets. The results are shown in Table 4.

Vb: Black part potential, Vw: White part potential, Vr: Residual potential after static elimination

[0083]

[Table 4]

Examples 31 to 40 An intermediate layer made of polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) having a thickness of 0.5 μm was provided on a cylindrical aluminum substrate, and a Bragg angle 2θ of 9.5 ° in X-ray diffraction was provided thereon. 24.1 °, 27.
A liquid in which 1 part of titanyl phthalocyanine having a peak at 2 ° and 0.5 part of silicone-butyral resin and 50 parts of methyl isopropyl ketone as a dispersion medium were dispersed using a sand mill was dip-coated to form a carrier generation layer having a thickness of 0.3 μm. Next, 1 part of the exemplified compound shown in Table 5 and polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.) 1.5
Parts were dissolved in 10 parts of tetrahydrofuran, and dip-coated on the carrier generation layer to form a carrier transport layer having a film thickness of 20 μm, and Example photoconductors 31 to 40 were produced.

[0085]

[Table 5]

Comparative Example 3 A comparative sample was prepared in the same manner as in Example 31 except that the comparative compound represented by the chemical formula (K-3) was used in place of the exemplified compound A-6.

Evaluation 3 With respect to the electrophotographic photosensitive member samples obtained in Example 31 and Comparative Example 3, a digital copy "Ko" manufactured by Konica Corporation was used.
Images were output with a modified machine of "nica9028" (positive charging polarity: reverse development). Next, these samples were left in a low temperature (10 ° C.) environment for 1 month, and thereafter, images were displayed again under the same conditions. The black spots on the white background portion of these copied images were evaluated. The results are shown in Table 6.

The black spots were evaluated by measuring the size and number of the black spots using an image analyzer "Omnicon 300 type" (manufactured by Shimadzu Corporation), and a black spot having a diameter of 0.05 mm or more was 1 cm ^2.
It was performed by judging how many there are. The criteria for evaluating the black spots are as shown below. It should be noted that if the result of the black spot determination is ⊚ and ◯, it is practical, but Δ is not suitable for practical use, and if it is ×, it is not suitable for practical use.

[0089]

[Table 6]

[0090]

[Table 7]

As described above, the electrophotographic photosensitive member using the carrier transporting material of the present invention has higher sensitivity than the conventional electrophotographic photosensitive member using the carrier transporting material, and the photosensitive member after repeated use. It can be seen that the characteristics are stable and the occurrence of image defects is extremely small even after storage at low temperature.

[0092]

Industrial Applicability According to the present invention, it is possible to provide an electrophotographic photoreceptor having high sensitivity, a small residual potential, and excellent durability which does not change the characteristics even when it is repeatedly used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hirofumi Hayata Konica Stock Company, Hino City, Hino City, Tokyo 1 (72) Inventor Tomomi Oshiba 1, Konica Stock Company, Sakura City, Hino City, Tokyo In-house

Claims (4)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the general formula (A1) or the general formula (A2) as a charge transporting substance. Characteristic electrophotographic photoreceptor. [Chemical 1] (In the formula, R ₁ represents a substituted or unsubstituted alkyl group,
R ₂ is a substituted or unsubstituted alkyl group, alkoxy group,
Represents an aryl group. R ₃ and R ₄ each independently represent hydrogen, halogen, a substituted or unsubstituted alkyl group and alkoxy group, a nitro group, a cyano group, an alkoxycarbonyl group, or an acyl group, and n and m each represent an integer of 0 to 2. Represent X represents a single bond, O, S or SO ₂ . ) 2. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the general formula (B1) or the general formula (B2) as a charge transporting substance. Characteristic electrophotographic photoreceptor. [Chemical 2] (In the formula, R ₅ represents a substituted or unsubstituted alkyl group,
R ₆ is a substituted or unsubstituted alkyl group, alkoxy group,
Represents an aryl group, each R ₇ independently represents a halogen, a cyano group, a substituted or unsubstituted alkyl group and an alkoxy group,
Represents an aryl group. Further, o is an integer of 0 to 2, p is 1 to 2
Represents the integer. ) 3. An electrophotographic photosensitive member having a photosensitive layer provided on a conductive support, wherein the photosensitive layer contains a compound represented by the general formula (C) as a charge transporting substance. body. [Chemical 3] (In the formula, R ₈ and R ₉ are each independently hydrogen, halogen, a substituted or unsubstituted alkyl group and an alkoxy group, a nitro group,
Represents a cyano group, an acyl group, an alkoxycarbonyl group,
R ₁₀ represents a substituted or unsubstituted alkyl group or halogen. Moreover, q and r represent the integer of 0-2, s represents the integer of 1-2. ) 4. An electrophotographic photoreceptor having a photosensitive layer provided on a conductive support, wherein the photosensitive layer is represented by the general formula (D1), (D2), (D3) or (D4) as a charge transporting substance. An electrophotographic photoreceptor containing a compound. [Chemical 4] (In the formula, each R ₁₁ independently represents a halogen, a cyano group, a substituted or unsubstituted alkyl group and an alkoxy group, or an aryl group, and R ₁₂ represents a substituted or unsubstituted alkyl group or a halogen. Is an integer of 2 and y is an integer of 1 to 2.)