JPH0934141A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high sensitivity by using an electron transferring material having satisfactory compatibility with a resin binder, low coloring property and high mobility. SOLUTION: This electrophotographic photoreceptor has a photosensitive layer contg. a quinone deriv. represented by the general formula on the electrically conductive substrate. In the formula, each of R1 and R2 is cyano, nitro, halogen, acyclic or cyclic hydrocarbon or alkoxy of the hydrocarbon and each of the hydrocarbon and alkoxy may have a substituent excepting cyano, nitro groups and halogen, and may be the same or differed from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used in copying machines, laser printers and the like.

[0002]

2. Description of the Related Art Conventionally, selenium, selenium-tellurium, selenium-arsenic, amorphous-silicon, etc. have been used for photoconductors of copying machines and laser printers. However,
In recent years, organic photoreceptors, which are low in price and have little environmental pollution, are becoming mainstream. As the organic photoreceptor, a charge generation layer (CG
There are known a function-separated type photoreceptor in which L) and a charge transfer layer (CTL) are laminated, and a single layer dispersion type photoreceptor in which a charge generation substance is dispersed in a medium of a charge transfer substance.

The charge transfer substances of these photoconductors are as follows:
Although substances with high mobility are required, most of the organic photoconductors that have been put into practical use are limited to the negative charging type because most substances have hole mobility. However, since the charging of the photoconductor uses corona discharge, the negative charging type electrophotographic method often generates ozone, which causes problems such as contamination of the indoor environment and accelerated deterioration of the photoconductor. In order to prevent these, a special charging method that does not generate ozone, a filter that filters the ozone that is generated, and the like are required, and there are drawbacks such that the electrophotographic process and apparatus are complicated and expensive.

In order to reduce such ozone generation, the market demand for positively charged type photoconductors has increased, and a high mobility electron transfer material is required for the development of the photoconductor. Examples of this electron transfer substance include trinitrofluorenone (TNF), tetracyanoethylene, tetracyanoquinodimethane (TCNQ), quinone, diphenoquinone, naphthoquinone, anthraquinone and their derivatives, but they are compatible with binder resins. There are many substances that are not good, and it is impossible to uniformly disperse them in a high concentration in the charge transfer layer of the photosensitive layer. Explaining these substances in detail, for example, TNF, which has a high electron accepting property, has a drawback that it is highly toxic and not suitable for practical use. Further, although TCNQ has an extremely high electron accepting property, TCNQ has poor compatibility with a binder resin and cannot be uniformly dispersed in a high concentration in a charge transfer layer.
Further, since TCNQ is strongly colored, it has a drawback that when the photosensitive layer is formed, it absorbs the light that should originally reach the charge generating substance, thereby lowering the sensitivity.

The diphenoquinone derivative has a relatively good compatibility with the binder resin, but since the molecule is large, the coloring property becomes strong, and the sensitivity is lowered for the same reason as TCNQ. In addition, although an asymmetric substitution type derivative has been proposed in the diphenoquinone skeleton, it is not satisfactory as an electron transfer material to provide a highly sensitive positively charged electrophotographic photoreceptor. As described above, at present, a satisfactory high-sensitivity positive charging type electrophotographic photosensitive member has not been obtained.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photosensitive member having a high sensitivity by using an electron transfer substance having a high compatibility with a binder resin and a weak coloring property and a high mobility. It is in.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors, the difficulty of compatibility with a binder resin is related to the asymmetry of the molecule of the electron transfer substance, and the strength of the coloring property is
Focusing on the relationship with the size of the molecule of the electron transfer substance, the inventors have found a novel quinone derivative capable of obtaining highly sensitive electrophotographic characteristics, and achieved the present invention.

That is, the present invention is an electrophotographic photosensitive member characterized by having a photosensitive layer containing a novel quinone derivative represented by the following general formula (I) on a conductive substrate.

Embedded image (In the formula (I), R ₁ and R ₂ are cyano, nitro, halogen, an acyclic hydrocarbon group and a cyclic hydrocarbon group or an alkoxy group of these hydrocarbons, and a substituent other than cyano, nitro and a halogen group is a substituent. May exist, and R ₁ and R ₂ may be the same or different.)

Specifically, the inventors of the present invention focused on the fact that the coloring property is related to the size of the intramolecular conjugated structure, and based on the results of studies on the quinone skeleton, the substituent on one side of p-quinone was It was found that the use of dicyanomethane group enhances the electron accepting property and does not deteriorate the compatibility with the resin. Furthermore, they have found that the introduction of an o-substituent into the oxygen on the opposite side of the dicyanomethane group improves the compatibility with the resin significantly.

The novel quinone derivative according to the present invention has the following characteristics. (1) In order to develop a highly sensitive positive charging type electrophotographic photoreceptor, an electron transfer substance having a high mobility is required. Although it must have a high electron accepting property in order to become an electron-transferring substance, the quinone derivative of the present invention has an extremely high electron accepting property. (2) The quinone derivative of the present invention has extremely good compatibility with the resin used as the binder of the photosensitive layer, and can be uniformly contained in the charge transfer layer at a high concentration. (3) The quinone derivative of the present invention has a weak coloring property and therefore has low absorption of incident light, so that sensitivity is hardly reduced. When the quinone derivative of the present invention is added to a negatively chargeable electrophotographic photoreceptor together with a hole transfer substance, it has the effect of improving sensitivity and lowering the residual potential by the electron transfer action thereof. It can also be used for electrophotographic photoreceptors.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The quinone derivative of the present invention is
In the positive and negative charging type electrophotographic photoconductors, they function as a charge transfer material as an electron transfer material. In the photoconductor, the type and shape of the conductive substrate, the constitution and thickness of the photosensitive layer, and the photosensitive layer are constituted. Resin, which is another component,
The kind and the concentration of the additive are not limited, but it is preferable to add it in the photosensitive layer in a concentration of 0.1% by weight to 80% by weight. The quinone derivative may be used alone or in combination of two or more.

Examples of the constitution of the photoconductor of the present invention are shown in FIGS.
Shown in FIG. 1 is a cross-sectional view of a single-layer dispersion type photosensitive member. Reference numeral 1 is a conductive substrate, and 2 is a photosensitive layer in which a charge generating substance is dispersed in a medium of a charge transfer substance. FIG. 2 is a cross-sectional view of the function-separated type photosensitive member. Reference numeral 1 is a conductive substrate, 3 is a charge generation layer, 4 is a charge transfer layer, and the charge generation layer 3 and the charge transfer layer 4 form a photosensitive layer. Is forming.

As the conductive substrate 1, various conductive materials can be used, such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold,
A simple substance of metal such as silver, copper, tin, platinum, molybdenum, or indium, or an alloy thereof, a conductive substance such as the above metal or carbon is deposited,
Conductive plastic plates and films treated by plating, tin oxide, indium oxide,
There is conductive glass coated with aluminum iodide. Generally, a cylindrical aluminum tube alone, a product whose surface is treated with alumite, and a product coated with a conductive resin are often used.

As the charge generating substance, for example, selenium,
Examples include selenium-tellurium, selenium-arsenic, amorphous-silicon, phthalocyanine pigment, monoazo pigment, bisazo pigment, trisazo pigment, polyazo pigment, indigo pigment, slene pigment, toluidine pigment, pyrazoline pigment, perylene pigment, quinacridone pigment, and pyrylium salt. Is
These are not only used alone, but may be used as a mixture of two or more kinds in order to obtain an appropriate photosensitivity wavelength and an appropriate sensitizing action.

In order to improve electrophotographic properties such as high sensitivity and reduction of residual potential, known charge transfer substances can be added. For example, in the case of polymer compounds, polyvinylcarbazole, halogenated polyvinylcarbazole, polyvinylpyrene, polyvinyl are used. Indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl pyrazoline, polyacetylene,
Conductive polymers such as polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, polyphthalocyanine Examples include compounds, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethacrylic acid, and the like, and solid polymer electrolytes in which a metal ion such as lithium is doped. Further, as low molecular weight compounds, polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, nitrogen-containing heterocyclic compounds such as indole, carbazole and imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, triphenylmethane and triphenylmethane. Any known compounds such as phenylamine, enamine and stilbene compounds can be used, and further known organic charge transfer complex formed of an electron donating compound represented by tetrathiafulvalene-tetracyanoquinodimethane and an electron accepting compound. Etc., and one or more of them may be mixed to obtain desired photoreceptor characteristics.

The binder resin used for forming the photosensitive layer is polycarbonate resin, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene resin, vinyl chloride resin, vinyl chloride-vinyl acetate resin, Photocurable polyester resin, alkyd resin, polyamide resin, polyurethane resin, epoxy resin, polyarylate resin, polysulfone resin, diarylate resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, epoxy allylate, etc. There are resins, and these are used alone or in combination of two or more. It is also possible to mix resins having different molecular weights in order to improve hardness and abrasion resistance.

Solvents used for the coating liquid include alcohols such as methanol, ethanol, n-propanol, i-propanol and butanol, saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane and cycloheptane, Aromatic hydrocarbons such as toluene and xylene, chlorine-based hydrocarbons such as dichloromethane, dichloroethane, chloroform and chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran and methoxyethanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Ketones, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate and other esters, N, N-dimethylformamide, dimethylsulfone There is Sid, etc., which may be used alone or in combination. The coating method is performed by a known coating means.

The coating liquid for producing the photoreceptor of the present invention contains known substances such as antioxidants, ultraviolet absorbers, radical scavengers, softeners, etc. within the range of not impairing the characteristics of the electrophotographic photoreceptor. A curing agent, a crosslinking agent, etc. can be added,
As a result, the characteristics, durability, mechanical characteristics, etc. of the photoconductor are improved. Furthermore, by adding a dispersion stabilizer, an anti-settling agent, an anti-color separation agent, a leveling agent, a defoaming agent, a thickening agent, a matting agent, etc., the finished appearance of the photoreceptor and the life of the coating liquid can be improved. .

In the electrophotographic photosensitive member of the present invention, an undercoat layer having an adhesive function, a barrier function, a defect covering function on the surface of the substrate and the like may be provided between the conductive substrate and the photosensitive layer. As the undercoat layer, aluminum oxide, polyethylene resin,
Acrylic resin, epoxy resin, polycarbonate resin,
Polyurethane resin, vinyl chloride resin, vinyl acetate resin,
Polyvinyl butyral resin, polyamide resin, nylon resin and the like can be used alone or in combination.
Further, an undercoat layer in which a metal oxide or carbon is dispersed in resin can also be used.

A surface protective layer may be provided on the photosensitive layer for the purpose of improving the durability of the photosensitive member, and the material thereof is polyvinyl formal resin, polycarbonate resin, fluororesin, polyurethane resin, silicone resin, or the like. There is. Further, a surface protective layer composed of a siloxane structure formed of a hydrolyzate of a silane coupling agent may be used.

Production Example of Quinone Derivative The quinone derivative of the above formula (I) is produced by the following method. The first method is used when a substance in which the desired substituent is substituted at the 2,6-position of p-quinone is commercially available, and this reaction is dicyanomethanation of an oxygen atom on one side of the p-quinone compound, A method for obtaining a quinone derivative of formula (I).

[0022]

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[Production Example 1] 10.0 g of 3,5-dimethylbenzoquinone and 5.0 g of malononitrile were dissolved in 240 ml of dichloromethane and stirred in an ice bath. While keeping the temperature at 10 ° C. or lower, 6.6 ml of titanium tetrachloride was slowly dropped, and similarly, 24.0 ml of pyridine was slowly dropped, and the mixture was reacted at room temperature for 5 hours while stirring. The residue was distilled under reduced pressure, 200 ml of 10% hydrochloric acid was added to the residue, the mixture was vigorously stirred, filtered, washed with water several times and dried. This was recrystallized from hexane for purification and 3,5-dimethyl-4
4.0 g of -oxo-1-dicyanomethylenecyclohexadiene (I) a was obtained with a yield of 32%.

[Production Example 2] 3,5-dichlorobenzoquinone (10.0 g) and malononitrile (4.0 g) were dissolved in dichloromethane (240 ml), and the mixture was stirred in an ice bath. While keeping the temperature at 10 ° C. or lower, 6.6 ml of titanium tetrachloride was slowly dropped, and similarly, 24.0 ml of pyridine was slowly dropped, and the mixture was reacted at room temperature for 5 hours while stirring. The residue was distilled under reduced pressure, 200 ml of 10% hydrochloric acid was added to the residue, the mixture was vigorously stirred, filtered, washed with water several times and dried. This was recrystallized from hexane and purified to give 3,5-dichloro-4.
3.6 g of -oxo-1-dicyanomethylenecyclohexadiene (I) b was obtained with a yield of 28%.

The second method is used when a substance in which the desired substituent is substituted at the 2,6-position of p-quinone is not commercially available. In this method, the substituent is first attached at the 2,6-position. A p-quinone compound is obtained from a phenol compound, and this is made into a quinone derivative of the formula (I) by the same reaction as in Production Examples 1 and 2 above.

[0026]

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[Production Example 3] 3,5-di-tBu- which is a raw material
Hydroxylanisole 33.0 g to acetonitrile 3
It was dissolved in 00 ml, the temperature was maintained at 0 to 10 ° C. under nitrogen gas, 7.8 ml of bromine was added, and the mixture was stirred. While maintaining the temperature at 10 ° C. or lower, a mixed solution of 34.8 ml of pyridine and 60 ml of acetonitrile was added dropwise. 10 ° C with stirring
The reaction was performed for 1 hour below, 2 hours at room temperature, 450 ml of cold water was added, and the reaction was continued for 3 hours. This was extracted with hexane, the hexane solution was washed with a 90% aqueous methanol solution, and then hexane was removed under reduced pressure to obtain 3,5-di-tBu-benzoquinone 2
1.0 g was obtained with a yield of 87% as a brown liquid.

3,5-di-tBu-benzoquinone 18.
0g and 5.3g malononitrile in 240g dichloromethane
It was dissolved in ml and stirred on an ice bath. Titanium tetrachloride (8.8 ml) was slowly dropped while keeping the temperature at 10 ° C. or lower, and similarly, pyridine (32.2 ml) was slowly dropped, and the mixture was reacted at room temperature for 5 hours while stirring. Dichloromethane was removed by concentration under reduced pressure, and 200 ml of 10% hydrochloric acid was added to the residue.
Was added and the mixture was vigorously stirred, filtered, and the residue was washed several times with water and dried. Further recrystallization operation with hexane,
The yield of 3.8 g of 3,5-di-tBu-4-oxo-1-dicyanomethylenecyclohexadiene (I) c was 17.
Obtained at 3%.

The third method is a method of arbitrarily introducing a substituent at the 2,6 position in the quinone derivative of the formula (I) and is useful as a method for producing an electron transfer substance. In this method, nitromalonaldehyde and alkyl ketone are reacted to produce 2,6
After a substituted p-nitrophenol compound was synthesized and used as a quinone compound, the quinone derivative of the formula (I) was obtained by the same reaction as in Production Examples 1 and 2.

[0030]

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[Production Example 4] 24.3 ml of water and 25.0 g of sodium nitrite were heated and dissolved with stirring. Mucobromic acid 25.0 g 95% ethanol solution 24.3 m
1 was added dropwise while maintaining the temperature at 54 ± 1 ° C. After dripping, 5
The mixture was kept at 4 ± 1 ° C. and stirred for 10 minutes. Cool to 0-5 ° C,
The precipitate was filtered and dissolved in 80 ml of 95% ethanol and 20 ml of water while heating.
After cooling to ℃, 6.0 g of sodium nitromalonaldehyde monohydrate was obtained with a yield of 39%.

8.8 g of 1,3 diphenyl-2-propane
44 ml of ethanol solution and 3.3 g of sodium hydroxide
15 ml of an aqueous solution of nitromalonaldehyde and 64 g of an aqueous solution of 7.4 g of sodium nitromalonaldehyde monohydrate were refluxed for 2 hours,
Stir at room temperature for 2 days. The solvent was removed by distillation under reduced pressure, 10% hydrochloric acid was added to the residue with stirring, and the mixture was filtered. 1-2
Recrystallize from acetic acid / ethanol containing a drop of concentrated hydrochloric acid,
8.9 g of 2,6-diphenyl-4-nitrophenol was obtained with a yield of 65%.

To 50 ml of acetic acid, 8.9 g of lead tetraacetate, 2,6
-Add 6.7 g of diphenyl-4-nitrophenol and add 2
Stir for 4 hours. The reaction solution was extracted with ether, washed with water, and further washed with a 5% aqueous sodium hydroxide solution and water in this order. This was dehydrated with sodium sulfate, ether was removed, and recrystallized from ethanol to give 2,6-diphenyl-
3.4 g of 1,4-benzoquinone was obtained with a yield of 57%.

To 150 ml of dichloromethane were added 5.7 g of 2,6-diphenyl-1,4-benzoquinone and 1.7 g of malononitrile, and the mixture was stirred under N ₂ . Keeping the temperature below 10 ° C, 2.8 ml of titanium tetrachloride, followed by pyridine 1
0.0 ml was slowly added dropwise, and after stirring at room temperature for 5 hours, the solvent was removed by distillation under reduced pressure. The residue was extracted with warm hexane, washed with 1N hydrochloric acid and then with water to remove the solvent. Silica gel is used as a packing material, and the eluent is hexane / ethyl acetate =
Purified by column chromatography using 2 (volume ratio) to obtain 0.8 g of 3,5-diphenyl-4-oxo-1-dicyanomethylenecyclohexadiene (I) d in a yield of 1
Obtained at 1%.

[Production Example 5] In place of 1,3 diphenyl-2-propane of Production Example 4, 4.2 g of 3-hexanone was used, and 3-ethyl-5-methyl-4-oxo-1-dicyanomethylene was used. 1.3 g of cyclohexadiene (I) e was obtained with a yield of 15%.

The quinone derivatives (I) a to (I) e obtained in the above Production Examples 1 to 5 are shown below.

[0037]

[Chemical 6]

[0038]

[Chemical 7]

[0039]

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[0040]

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[0041]

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[0042]

EXAMPLES Examples of electrophotographic photosensitive members according to the present invention will be shown below. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 1 part by weight of the disazo pigment represented by the formula (II) as a charge generating agent, 10 parts by weight of a polycarbonate as a binder, and 80 parts by weight of THF as a solvent were kneaded and dispersed in a sand mill for 10 hours, and then the formula (III) was added. ) TPD
9 parts by weight of the derivative and 1 part by weight of the quinone derivative of the formula (I) a were added and dissolved, and this solution was used to apply the solution onto an aluminum drum by a dipping method so as to have both a charge generation and a charge transfer of a thickness of 20 μm. 1 layer dispersion type photosensitive layer 2 is formed at 80 ° C.
After drying for an hour, an electrophotographic photosensitive member was manufactured.

[0044]

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[0045]

[Chemical 12]

Example 2 A photoconductor was produced by using a quinone derivative of the formula (I) b in place of the quinone derivative of the formula (I) a of Example 1.

Example 3 Instead of the quinone derivative of the formula (I) a of Example 1, a quinone derivative of the formula (I) c was used to produce a photoreceptor.

Example 4 Instead of the quinone derivative of the formula (I) a of Example 1, a quinone derivative of the formula (I) d was used to produce a photoreceptor.

Example 5 A photoconductor was prepared by using a quinone derivative of the formula (I) e instead of the quinone derivative of the formula (I) a of Example 1.

Comparative Example 1 3,5-dichloroquinone was used in place of the quinone derivative of the formula (I) a of Example 1 to prepare a photoreceptor.

Comparative Example 2 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a in Example 1.

Comparative Example 3 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 1.

Example 6 1 part by weight of high-purity oxytitanyl phthalocyanine as a charge generating agent, 10 parts by weight of polycarbonate as a binder, and 80 parts by weight of THF as a solvent were kneaded and dispersed in a sand mill for 10 hours, and further mixed by the formula (III).
9 parts by weight of the TPD derivative of and a quinone derivative of the formula (I) a 1
After adding and dissolving parts by weight, this solution was applied onto an aluminum drum by a dipping method to form a single-layer dispersion type photosensitive layer 2 having a thickness of 20 μm and having both charge generation and charge transfer.
An electrophotographic photosensitive member was manufactured by drying at 0 ° C. for 1 hour.

Example 7 A photoconductor was produced by using a quinone derivative of the formula (I) b in place of the quinone derivative of the formula (I) a of Example 6.

Example 8 A photoconductor was manufactured by using a quinone derivative of the formula (I) c in place of the quinone derivative of the formula (I) a of Example 6.

Example 9 A photoconductor was produced by using a quinone derivative of the formula (I) d in place of the quinone derivative of the formula (I) a of Example 6.

Example 10 A photoconductor was manufactured by using a quinone derivative of the formula (I) e in place of the quinone derivative of the formula (I) a of Example 6.

Comparative Example 4 A photoconductor was prepared by using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a in Example 6.

Comparative Example 5 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a in Example 6.

Comparative Example 6 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 6.

Example 11 2 parts by weight of the disazo pigment represented by the formula (II) and 1 part by weight of polyvinyl butyral as a binder were dry-kneaded, and then 1,4-as a solvent.
Dioxane (16 parts by weight) and acetone (4 parts by weight) were added, and the mixture was dispersed in a sand mill for 2 hours. This was applied as a coating liquid on an aluminum drum by dip coating and then dried to a thickness of 0.
The charge generation layer 3 having a thickness of 5 μm was formed. Then, the formula (I) a
10 parts by weight of the quinone derivative of
A coating solution obtained by adding 1 part by weight and 100 parts by weight of THF to the surface of the charge generation layer 3 is dip-coated to form a charge transfer layer 4 having a thickness of 20 μm, and dried at 80 ° C. for 1 hour to obtain a functional separation type. An electrophotographic photoreceptor was manufactured.

Example 12 A photoconductor was produced by using a quinone derivative of the formula (I) b in place of the quinone derivative of the formula (I) a of Example 11.

Example 13 A photoconductor was manufactured by using a quinone derivative of the formula (I) c in place of the quinone derivative of the formula (I) a of Example 11.

Example 14 A photoconductor was produced using the quinone derivative of formula (I) d instead of the quinone derivative of formula (I) a of Example 11.

Example 15 A photoconductor was produced by using a quinone derivative of the formula (I) e in place of the quinone derivative of the formula (I) a of Example 11.

Comparative Example 7 A photoconductor was prepared by using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a in Example 11.

Comparative Example 8 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a of Example 11.

Comparative Example 9 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 11.

Example 16 High purity oxytitanyl phthalocyanine was vapor-deposited on an aluminum drum, which is a conductive substrate, at a pressure of 10 ⁻⁵ torr and a heating temperature of 500 ° C. to a film thickness of 500 Å. A charge generation layer 3 as shown was formed. Next, 10 parts by weight of polycarbonate and 100 parts by weight of THF were added to 10 parts by weight of the quinone derivative of the formula (I) a, and a coating solution obtained by dissolving was applied to the surface of the charge generation layer 3 by dip coating to form a charge transfer layer having a thickness of 20 μm. 4 was formed and dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photosensitive member.

Example 17 A photoconductor was produced using the quinone derivative of formula (I) b instead of the quinone derivative of formula (I) a of Example 16.

Example 18 A photoconductor was produced by using a quinone derivative of the formula (I) c in place of the quinone derivative of the formula (I) a of Example 16.

Example 19 A photoconductor was manufactured by using a quinone derivative of the formula (I) d in place of the quinone derivative of the formula (I) a of Example 16.

Example 20 A photoconductor was produced by using a quinone derivative of the formula (I) e in place of the quinone derivative of the formula (I) a of Example 16.

Comparative Example 10 A photoconductor was prepared by using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a in Example 16.

Comparative Example 11 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a in Example 16.

Comparative Example 12 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 16.

[Example 21] 5 g of high-purity oxytitanyl phthalocyanine was dry ground together with 50 ml of glass beads with a paint shaker for 100 hours. Next, add 50 ml of n-propanol and 5 g of polyvinyl butyral,
Wet mill for 1 hour. Furthermore, methyl ethyl ketone 1
Add 00 ml and disperse for 10 hours. The solution obtained by dispersion was dip-coated on an aluminum drum and dried to form a charge generation layer 3 having a thickness of 0.2 μm. Then
A coating solution obtained by adding 10 parts by weight of polycarbonate and 100 parts by weight of THF to 10 parts by weight of the quinone derivative of the formula (I) a and dissolving the coating solution was applied onto the surface of the charge generation layer 3 by dip coating to obtain a thickness of 20.
A charge transfer layer 4 having a thickness of μm was formed and dried at 80 ° C. for 1 hour to manufacture a function-separated electrophotographic photoreceptor.

Example 22 A photoconductor was produced using the quinone derivative of formula (I) b instead of the quinone derivative of formula (I) a of Example 21.

Example 23 A photoconductor was produced using the quinone derivative of formula (I) c instead of the quinone derivative of formula (I) a of Example 21.

Example 24 A photoconductor was produced by using a quinone derivative of the formula (I) d in place of the quinone derivative of the formula (I) a of Example 21.

Example 25 A photoconductor was produced using the quinone derivative of formula (I) e instead of the quinone derivative of formula (I) a of Example 21.

Comparative Example 13 A photoconductor was prepared by using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a of Example 21.

Comparative Example 14 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a of Example 21.

Comparative Example 15 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a in Example 21.

Example 26 2 parts by weight of the disazo pigment represented by the above formula (II) and 1 part by weight of polyvinyl butyral as a binder were dry-kneaded, and then 16 parts by weight of 1,4-dioxane and 4 parts by weight of acetone were used as a solvent. Was added and dispersed in a sand mill for 2 hours, and this was applied as a coating liquid on an aluminum drum by dip coating and then dried to a thickness of 0.5 μm.
m charge generating layer 3 was formed. Then, TP of formula (III)
To 10 parts by weight of the D derivative, 10 parts by weight of polycarbonate, 100 parts by weight of THF, and 1 part by weight of the quinone derivative of the formula (I) a were added and dissolved to obtain a coating solution, which was applied by dipping onto the surface of the charge generation layer 3 to give a thickness of 20 μm. After the charge transfer layer 4 was formed, it was dried at 80 ° C. for 1 hour to produce a function-separated electrophotographic photoreceptor.

Example 27 A quinone derivative of formula (I) b was used in place of the quinone derivative of formula (I) a of Example 26 to produce a photoreceptor.

Example 28 A photoconductor was produced by using a quinone derivative of the formula (I) c in place of the quinone derivative of the formula (I) a of Example 26.

Example 29 A photoconductor was produced by using a quinone derivative of the formula (I) d in place of the quinone derivative of the formula (I) a of Example 26.

Example 30 A photoconductor was produced using the quinone derivative of formula (I) e in place of the quinone derivative of formula (I) a of Example 26.

Comparative Example 16 A photoconductor was prepared by using 3,5-dichloroquinone instead of the quinone derivative of the formula (I) a of Example 26.

Comparative Example 17 A photoconductor was prepared by using 3,5-diphenylquinone instead of the quinone derivative of the formula (I) a in Example 26.

Comparative Example 18 A photoconductor was prepared by using tetracyanoquinodimethane instead of the quinone derivative of the formula (I) a of Example 26.

In Examples 1 to 25 and Comparative Examples 1 to 15, the half-exposure energy (lux * sec), which is the sensitivity of the electrophotographic photosensitive member, was measured by the following method. First, corona discharge is performed in a dark place by an applied voltage whose voltage is set so that the corona discharge current is 17 μA, the photoreceptor is positively charged, and then exposed to white light to reduce the surface potential from 700 V to 350 V by half. I asked for energy.

In the results of the present invention of Examples 1 to 5 shown in Table 1, the single layer dispersion type positively charged photoreceptors using the disazo pigment of the formula (II) as a charge generating agent were the photoreceptors of Comparative Examples 1 to 3. The sensitivity is obviously higher than that of.

[0095]

[Table 1]

In the results of the present invention of Examples 6 to 10 shown in Table 2, the single layer dispersion type positively charged photoconductors using oxytitanyl phthalocyanine as the charge generating agent are clearly compared with the photoconductors of Comparative Examples 4 to 6. It has high sensitivity.

[0097]

[Table 2]

In the results of the present invention of Examples 11 to 15 shown in Table 3, the function-separated positively charged photoreceptors in which the disazo pigment of the formula (II) was dispersed and applied together with the resin to form the charge generation layer, Although the sensitivity characteristics are shown, Comparative Examples 7 to 9 show no sensitivity at all.

[0099]

[Table 3]

In the results of Examples 16 to 20 of the present invention shown in Table 4, the function-separated positively charged photoreceptors in which the charge generation layer was formed by vacuum deposition of oxytitanyl phthalocyanine showed sensitivity characteristics. Examples 10-12 show no sensitivity at all.

[0101]

[Table 4]

In the results of the present invention of Examples 21 to 25 shown in Table 5, the function-separated positively charged photoreceptors in which oxytitanyl phthalocyanine was dispersed with a resin and then coated to form a charge generation layer showed sensitivity characteristics. However, Comparative Examples 13 to 1
5 shows no sensitivity.

[0103]

[Table 5]

Examples 26-30 and Comparative Examples 16-18
In, the half-exposure energy (lux * sec), which is the sensitivity of the electrophotographic photosensitive member, was measured by the following method. First, corona discharge is performed in a dark place by an applied voltage whose voltage is set so that the corona discharge current is 17 μA, the photoreceptor is negatively charged, and then exposed to white light, and the surface potential is −700 V.
Then, the exposure energy which halves to −350 V was obtained.

In the results of the present invention of Examples 26 to 30 shown in Table 6, the function-separated positively charged photoreceptors having the charge generating layer formed by coating the disazo pigment of the above formula (II) with a resin and coating The sensitivity is obviously higher than that of Comparative Examples 16 to 18.

[0106]

[Table 6]

[0107]

As described above, according to the electrophotographic photosensitive member of the present invention, the compatibility with the binder resin is good,
Since a quinone derivative, which is an electron transfer material having low coloring property and high mobility, was used as the photosensitive layer, a highly sensitive electrophotographic photoreceptor having durability and practical use could be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a single-layer dispersion type photoconductor of the present invention.

FIG. 2 is a configuration diagram of a function-separated type photoconductor of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 2 Photosensitive Layer 3 Charge Generation Layer 4 Charge Transfer Layer

Continued Front Page (72) Inventor Masato Nanasawa 1-8-10 Satokichi, Kofu-shi, Yamanashi Prefecture

Claims (1)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer containing a quinone derivative represented by the following general formula (I) on a conductive substrate. Embedded image (In the formula (I), R ₁ and R ₂ are cyano, nitro, halogen, an acyclic hydrocarbon group and a cyclic hydrocarbon group or an alkoxy group of these hydrocarbons, and a substituent other than cyano, nitro and a halogen group is a substituent. May exist, and R ₁ and R ₂ may be the same or different.)