JPH05197172A - Electrophotographic photosensitive body - Google Patents

Abstract

PURPOSE:To improve photosensitivity characteristic and the potential stability at the time of repeated use by containing specific compounds. CONSTITUTION:A compound expressed by the formula I is contained, where A indicates substituted or unsubstituted alkylidene group, cycloalkylidene group having the carbon number of 10 or below, or oxygen atom, sulfur atom, or substituted or unsubstituted amino group, Ar<1>, Ar<3>-Ar<5> indicate substituted or unsubstituted allylene group, Ar<2>, Ar<6> indicate substituted or unsubstituted aryl group, and X, Y indicate the substituent expressed by the formula II. In the formula II, Ar<7>, Ar<8> indicate substituted or unsubstituted aryl group, and R<1> indicates hydrogen atom, halogen atom, hydroxyl group, substituted or unsubstituted amino group, or a lower alkoxy group having the carbon number of 1-6 and capable of having a substituent. Phenyl group or naphthyl group is used for the aryol group of Ar<7>, Ar<8>, dimethylamino group is used for the amino group of R<1>, and methoxy group is used for the alkoxy group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor having a photosensitive layer having a charge generating substance and a charge transporting substance.

[0002]

2. Description of the Related Art Conventionally, selenium (S) has been used as a photoconductive material for a photoconductor used in an electrophotographic system.
e), cadmium sulfide (CdS), zinc oxide (Zn)
There are inorganic materials such as O) and amorphous silicon (a-Si). These inorganic photoreceptors have many advantages, but at the same time have various drawbacks, such as being harmful,
It has the drawbacks of not being easy to dispose of and high cost. For this reason, in recent years, many organic photoconductors using organic substances without these defects have been proposed and put to practical use. As the structure of these photoconductors, a material that generates charge carriers (hereinafter, referred to as a charge generation material) and a material that receives the generated charge carriers and transports the generated charge carriers (hereinafter, referred to as a charge transport material). ) And a function-separated photoreceptor having a multi-layer structure having separate layers, and a single-layer photoreceptor in which charge generation and charge transport are performed in the same layer. It is widely used because of its wide selection of materials and high sensitivity.

As the charge transport medium, there are a case where a high molecular weight photoconductive compound such as polyvinyl carbazole is used and a case where a low molecular weight photoconductive compound is dispersed and dissolved in a binder polymer. The polymer photoconductive compound alone has insufficient film-forming properties and adhesiveness, and plasticizers, binder polymers, etc. are added to improve these points. This may cause a decrease and an increase in residual potential, which makes practical application difficult. On the other hand, a low molecular weight photoconductive compound can easily obtain a photoreceptor having excellent mechanical properties by appropriately selecting a binder polymer, but it is not sufficient in terms of sensitivity. For example, the diary described in US Pat. No. 3,820,989
Lualkane derivatives have few problems of compatibility with binder polymers, but have poor stability to light, and when they are used in the photosensitive layer of a photoreceptor for electrophotography, which undergoes repeated charging and exposure, the sensitivity of the photoreceptor is repeated. It has the drawback of gradually decreasing with use. In addition, the stilbene compound described in JP-A-58-65440 has a charge holding power,
The sensitivity and the like are relatively good, but the stability upon repeated use is not satisfactory. Also, these compounds remain problematic in sensitivity at low potentials. An object of the present invention is to provide an electrophotographic photoconductor having excellent photosensitivity characteristics and excellent potential stability during repeated use, by using a charge transport material composed of a novel organic photoconductive material. is there.

[0004]

The present invention is an electrophotographic photoreceptor containing a compound represented by the following general formula (1).

[Chemical 3] (In the formula, A represents a substituted or unsubstituted alkylidene group having 10 or less carbon atoms, a cycloalkylidene group, an oxygen atom, a sulfur atom, or a substituted or unsubstituted amino group. Ar ¹ , Ar ³ , Ar ⁴ , Ar ⁵ represents a substituted or unsubstituted arylene group, Ar ² and Ar ⁶ represent a substituted or unsubstituted aryl group, and X and Y are substituents represented by the following general formula (2). Indicates.

[Chemical 4] Here, Ar ⁷ and Ar ⁸ represent a substituted or unsubstituted aryl group. R ¹ is a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted amino group, a lower alkoxy group having 1 to 6 carbon atoms which may have a substituent, or a 1 to carbon atom which may have a substituent. 6 represents a lower alkyl group. )

Examples of the aryl group of Ar ⁷ and Ar ⁸ include a phenyl group and a naphthyl group. The amino group of R ¹ is a dimethylamino group, a diethylamino group, a diphenylamino group or the like, an alkoxy group is a methoxy group, an ethoxy group, a propoxy group, a butoxy group or the like, an alkyl group is a methyl group, an ethyl group, a propyl group, Butyl group, etc.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine atoms. As the alkylidene group of A, methylidene, 2,2-propylidene, 2-methylpropylidene group and the like, as the cycloalkylidene group, cyclohexylidene group, 4-tert-butylcyclohexylidene group and the like, and as the amino group, Examples thereof include a methylamino group, an ethylamino group and a phenylamino group. Ar ¹ , Ar ² , A
Examples of the aryl or arylene group of r ³ , Ar ⁴ , Ar ⁵ and Ar ⁶ include phenyl, naphthyl, anthryl, phenylene, naphthylene and anthrene groups.

The compound corresponding to the general formula (1) can be synthesized by a known method. For example, equation (3),

[Chemical 5] And a phosphite derivative represented by the formula (4):

[Chemical 6] A triphenylamine derivative by condensation with an aldehyde derivative represented by

[Chemical 7] Was synthesized and reacted with cyclohexanone. 2 can be synthesized. Examples of compounds of the general formula (1) of the present invention are shown in Tables 1 to 26.
However, the compound of the general formula (1) of the present invention is not limited to the above compound.

[0007]

[Table 1]

[0008]

[Table 2]

[0009]

[Table 3]

[0010]

[Table 4]

[0011]

[Table 5]

[0012]

[Table 6]

[0013]

[Table 7]

[0014]

[Table 8]

[0015]

[Table 9]

[0016]

[Table 10]

[0017]

[Table 11]

[0018]

[Table 12]

[0019]

[Table 13]

[0020]

[Table 14]

[0021]

[Table 15]

[0022]

[Table 16]

[0023]

[Table 17]

[0024]

[Table 18]

[0025]

[Table 19]

[0026]

[Table 20]

[0027]

[Table 21]

[0028]

[Table 22]

[0029]

[Table 23]

[0030]

[Table 24]

[0031]

[Table 25]

[0032]

[Table 26]

In the present invention, the compound represented by the general formula (1) is soluble in a solvent such as tetrahydrofuran, chloroform, dichloromethane, dichloroethane, toluene and chlorobenzene, and is coated with a liquid dissolved or dispersed together with a binder resin. By working, a film having high mechanical strength and excellent wear resistance can be produced, and thus it is useful as a charge transport material for an electrophotographic photoreceptor.
The electrophotographic photoreceptor of the present invention is preferably one in which an undercoat layer, a charge generation layer and a charge transport layer are laminated in this order on a conductive substrate, but an undercoat layer, a charge transport layer, a charge It may be one in which the generation layers are laminated in this order, or one in which the charge generation material and the charge transport material are dispersed and coated with an appropriate resin on the undercoat layer. The undercoat layer can be omitted if necessary. If necessary, an overcoat layer may be provided as the outermost layer.

By coating the compound according to the present invention with a suitable binder as a charge transporting material on a substrate, a charge transporting layer exhibiting high charge mobility, low residual potential and dark decay, and good cyclic stability. Can be obtained. Coating is spin coater, applicator, spray coater
Tar, bar coater, dip coater, doctor blade
De, Roller coater, Carter coater, Bead coater
It can be performed by using a normal coating device such as a tar and slide hopper. Drying is preferably heat drying, the temperature is 40 to 300 ° C., preferably 60 to 200 ° C., and the time is 2 minutes to 10 hours, preferably 10 minutes to 6 hours, under static or blown conditions. be able to.

The binder resin used when forming the charge transport layer by coating can be selected from a wide range of insulating resins that are commonly used. Further, it can be selected from organic photoconductive polymers such as polyvinyl carbazole resin, polyvinyl anthracene resin and polyvinyl pyrene resin. Specifically, polyvinyl butyral resin, polyarylate resin, polycarbonate resin, polyester resin, polyester carbonate resin, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide Resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin,
Silicone resin, polystyrene resin, polyether resin,
Polythioether resin, polyketone resin, polyvinyl chloride resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal resin, polyacrylonitrile resin, phenol resin, melamine resin, casein, polyvinyl alcohol resin, polyvinylpyrrolidone Insulating resins such as resins and polysilane can be mentioned, but the resins are not limited to these resins. The resin contained in the charge transport layer contains 99% by weight to
0% by weight, preferably 70% to 30% by weight, is suitable. These resins may be used alone or in combination of two or more.

The solvent that dissolves the charge transporting material varies depending on the type of resin and the like, but it is preferable to select a solvent that does not affect the charge generating layer and the undercoat layer described below during coating. Specifically, aromatic hydrocarbons such as benzene, toluene, xylene, ligroin, monochlorobenzene and dichlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, alcohols such as methanol, ethanol and isopropanol. , Esters such as ethyl acetate and methyl cellosolve, aliphatic halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane, dichloroethane and trichloroethylene, ethers such as tetrahydrofuran and dioxane, N, N-dimethylformamide , N, N-dimethylacetamide and other amides, and dimethyl sulfoxide and other sulfoxides are used, but are not limited to these solvents. The thickness of the charge transport layer of the electrophotographic photosensitive member is preferably 5 to 50 μm. More preferably, 1
0 to 30 μm is preferable. Various additives usually used, for example, an ultraviolet absorber, an antioxidant, an electron-withdrawing material, a plasticizer and the like can be added to the charge transport layer as required.

As the charge generating material, known photoconductive materials, for example, inorganic materials such as CdS, Se, ZnO and a-Si, or Si, Ge, Co, Cu, Al, In and T are used.
Phthalocyanines having metal atoms such as i, Pb and V,
Furthermore, organic materials such as metal-free phthalocyanine, azo pigments, bisazo pigments, trisazo pigments, polycyclic quinone pigments, perinone pigments or cyanine dyes, and squarylium dyes can be used alone or in combination.
The solvent that dissolves the charge generation material varies depending on the type of resin and the like, and it is preferable to select a solvent that does not affect the undercoat layer described below during coating. Specifically, aromatic hydrocarbons such as benzene, toluene, xylene, ligroin, monochlorobenzene and dichlorobenzene, acetone, methyl ethyl ketone, methyl isobutyl ketone,
Ketones such as cyclohexanone, methanol, ethanol
Alcohols such as alcohol and isopropanol, ethyl acetate,
Esters such as methyl cellosolve, carbon tetrachloride, aliphatic halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane and trichloroethylene, ethers such as tetrahydrofuran and dioxane, N, N-dimethylformamide, N, N-dimethyl Amides such as acetamide and sulfoxides such as dimethyl sulfoxide are used.

The thickness of the charge generation layer of the electrophotographic photosensitive member is 0.01 to 2 μm in order to maintain the chargeability and ensure the stability.
m is preferable, and 0.1 to 1 μm is more preferable. Further, if necessary, a plasticizer, an electron acceptor, an electron donor, etc. may be used together with the binder. The coating can be performed by a method similar to that for the charge transport layer described above. As the binder resin used for the undercoat layer, any resin can be used as long as it is a commonly used resin. For example, nylon 6, nylon 66, nylon 1
1, nylon 610, copolymer-soluble nylon, alcohol-soluble polyamide resin such as alkoxymethylated nylon, casein, polyvinyl alcohol resin, ethylene-acrylic acid copolymer, vinyl chloride-vinyl acetate-maleic acid copolymer, Epoxy resin, gelatin, polyurethane resin,
Cellulose resins such as polyvinyl butyral resin, nitrocellulose and carboxymethyl cellulose are used. The above resins can be used alone or as a mixture. Further, if necessary, an electron acceptor or an electron donor may be added. The undercoat layer can be applied by a method similar to that for the charge transport layer and the charge generation layer described above. At this time, the thickness of the undercoat layer is 0.01 to 20 μm, preferably 0.2 to 10 μm. Further, these undercoat layers can be omitted if necessary.

The electrophotographic photosensitive member of the present invention is used not only for copying machines, printers and facsimiles, but also for photoelectric conversion elements such as electrophotographic plate making, solar cells and electroluminescent elements.
It is also suitable as a material for optical conversion elements and optical discs. Although various structures of the electrophotographic photosensitive member are known, the electrophotographic photosensitive member of the present invention can take any of these forms. Usually, it has a cross-sectional structure as shown in FIGS. In FIGS. 1 and 2, a photosensitive layer 4 formed of a laminate of a charge generating layer 2 containing a charge generating substance as a main component and a charge transporting layer 3 containing a charge transporting substance as a main component on a conductive support 1. To provide. As shown in FIGS. 3 and 4, the photosensitive layer 4 may be provided via an undercoat layer 5 provided on a conductive support. Thus, when the photosensitive layer 4 has a two-layer structure, a photosensitive member having the most excellent electrophotographic characteristics can be obtained. Further, in the present invention, as shown in FIGS. 5 and 6, the photosensitive layer 4 obtained by dispersing the charge generating substance 7 in the layer 6 containing the charge transporting substance as a main component is directly provided on the conductive support 1. Alternatively, it may be provided via the undercoat layer 5. Further, in the present invention, the protective layer 8 may be provided as the outermost layer as shown in FIG.

[0040]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Example 1 An undercoat layer (0.1 μm thick) made of methoxymethylated nylon (T-8, manufactured by Unitika Ltd.) was formed on an aluminum substrate, and n was formed on the undercoat layer.
-Type titanyl phthalocyanine and polyvinyl butyral (Sekisui Chemical Co., Ltd. BX-1) containing a charge generation layer (0.1
μm thick) was formed. Furthermore, the exemplified compound No. 2 and Polycarbonate (Mitsubishi Gas Chemical Co., Ltd.)
Manufactured by Iupilon Z-200) (0.8: 1 weight ratio) was applied and dried at 90 ° C. for 60 minutes to form a 20 μm thick charge transport layer. The coatability of the film was good, and a film having sufficient coating strength was obtained. The evaluation of the electrophotographic characteristics was performed by using an electrostatic recording tester manufactured by Kawaguchi Electric Co.
After charging with kV corona discharge, dark decay for 3 seconds,
Irradiate 5 lux white light for 5 seconds, and its surface potential is 1
The time (seconds) until becoming 1/2 was obtained, and the half-exposure amount (lux seconds) was obtained. The results are shown in Table 27.

[0041]

[Table 27] ─────────────────────────────────── Initial 1000 After (lux ・ sec) (V ) (Lux ・ sec) (V) E _1/2 -Vr E _1/2 -Vr ────────────────────────────── ────── Example 1 0.4 -1 0.4 -2 ────────────────────────────────────

Examples 2 to 20 Exemplified compound Nos. Used in Example 1 above. A photoreceptor was prepared and measured in the same manner as in Example 1 except that the exemplified compounds shown in Table 28 below were used instead of 2.

[0043]

[Table 28] ─────────────────────────────────── Initial after 1000 times Exemplified compounds (lux / sec) (V) (lux ・ sec) (V) E _1/2 -Vr E _1/2 -Vr ──────────────────────────── ──────── Example 2 4 0.4 -1 0.4 -2 Example 3 7 0.3 0 0.3 -1 Example 4 12 0.3 0 0.3 -1 Example 5 18 0.5 0 0.5 -1 Example 6 28 0.3 0 0.3 -1 Example 7 43 0.4 -1 0.4 -2 Example 8 57 0.3 -1 0.5 -3 Example 9 64 0.5 -1 0.5 -2 Example 10 78 0.3 0 0.3 -1 Example 11 88 0.4 0 0.4 -1 Example 12 103 0.4 0 0.4 -2 Example 13 106 0.5 -1 0.5 -3 Example 14 110 0.4 0 0.4 -1 Example 15 115 0.3 0 0.3 0 Example 16 121 0.3 0 0.3 -1 Example 17 124 0.5 -1 0.5 -3 Example 18 126 0.4 0 0.4 -1 Example 19 140 0.3 0 0.3 0 Example 20 150 0.3 0 0.3 -1 ────────────────── ───── ────────────

Comparative Example 1 A comparative photoconductor was prepared in the same manner as in Example 1 except that the following compounds were used as the charge transport material. Table 29 shows the results of evaluation made on this comparative photoconductor in the same manner as in Example 1.

[0045]

[Chemical 8]

[0046]

[Table 29] ────────────────────────────────── Initial 1000 times (lux ・ sec) (V) (Lux ・ sec) (V) E _1/2 -Vr E _1/2 -Vr ─────────────────────────────── ──── Comparative Example 1 0.5 -10 0.6 -25 ───────────────────────────────────

Example 21 A polyamide resin (manufactured by Toray Industries, Inc., A-7) was formed on a conductive support obtained by vapor-depositing aluminum on a polyester film.
0), an undercoat layer (thickness of 0.1 μm) is formed, and τ-type metal-free phthalocyanine and butyral resin (Denka Butyler manufactured by Denki Kagaku Kogyo Co., Ltd.) are formed on the undercoat layer. Charge generation layer (0.1 μm thick) containing
Formed. Exemplified compounds N in Table 1 as charge transport materials
o. 3. Antioxidant (Japan Ciba-Geigy Co., Ltd.)
Manufactured by IRGANOX 1010) was added to the charge transport material in an amount of 1.5 wt% to prepare a photoconductor in the same manner as in Example 1. This photoreceptor was also evaluated in the same manner as in Example 1 and the results shown in Table 30 were obtained.

[0048]

[Table 30] ──────────────────────────────── Initial 1000 After (lux ・ sec) (V) (lux・ Sec) (V) E _1/2 -Vr E _1/2 -Vr ───────────────────────────────── Example 21 2.3 0 2.4 -1 ─────────────────────────────────

Examples 22 to 41 Exemplified compound Nos. Used in Example 21 above. Example 21 except that the exemplified compounds shown in Table 31 below were used in place of 3
A photoconductor was prepared and measured in the same manner as in.

[0050]

[Table 31] ─────────────────────────────────── Initial after 1000 times Exemplified compounds (lux / sec) (V) (lux ・ sec) (V) E _1/2 -Vr E _1/2 -Vr ──────────────────────────── ──────── Example 22 9 2.4 -1 2.4 -2 Example 23 16 2.3 0 2.3 -1 Example 24 27 2.4 0 2.4 -2 Example 25 35 2.5 -1 2.5 -1 Example 26 52 2.3 0 2.3 -1 Example 27 62 2.4 -1 2.4 -2 Example 28 70 2.3 -1 2.5 -3 Example 29 82 2.5 -1 2.5 -2 Example 30 92 2.3 0 2.3 -1 Example 31 97 2.4 0 2.4 -1 Example 32 105 2.4 0 2.4 -1 Example 33 112 2.5 -2 2.5 -3 Example 34 118 2.4 0 2.4 -1 Example 35 122 2.3 0 2.3 0 Example 36 128 2.3 0 2.3 -1 Example 37 138 2.4 -1 2.4 -2 Example 38 144 2.3 0 2.3 -1 Example 39 146 2.4 0 2.4 -2 Example 40 151 2.5 -1 2.5 -1 Example 41 154 2.3 0 2.3 -1 ── ──────────────────────────────────

Comparative Example 2 Example 21 except that the following compound was used as the charge transport material.
A comparative photoconductor was prepared in the same manner as in. The results of evaluation of this comparative photoconductor in the same manner as in Example 21 are shown in Table 32.
Shown in.

[0052]

[Chemical 9]

[0053]

[Table 32] ───────────────────────────────── Initial 1000 times (lux ・ sec) (V) ( lux ・ sec) (V) E _1/2 -Vr E _1/2 -Vr ──────────────────────────────── Comparative Example 2 4.0 -10 5.0 -30 ──────────────────────────────────

[0054]

As described in detail above, the electrophotographic photosensitive member of the present invention has excellent photosensitivity characteristics, small residual potential and dark decay, and little light fatigue, and thus exhibits good repeated stability. It has the feature of showing.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view of an embodiment of the present invention.

FIG. 3 is a sectional view of an embodiment of the present invention.

FIG. 4 is a sectional view of an embodiment of the present invention.

FIG. 5 is a sectional view of an embodiment of the present invention.

FIG. 6 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

1 Conductive Support 2 Charge Generation Layer 3 Charge Transport Layer 4 Photosensitive Layer 5 Undercoat Layer 6 Charge Transport Material-Containing Layer 7 Charge Generation Material 8 Protective Layer

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction content]

[0041]

[Table 27]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

[0043]

[Table 28]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction content]

[0048]

[Table 30]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

[0050]

[Table 31]

Claims (1)

[Claims] 1. An electrophotographic photosensitive member comprising a compound represented by the following general formula (1). [Chemical 1] (In the formula, A represents a substituted or unsubstituted alkylidene group having 10 or less carbon atoms, a cycloalkylidene group, an oxygen atom, a sulfur atom, or a substituted or unsubstituted amino group. Ar ¹ , Ar ³ , Ar ⁴ , Ar ⁵ represents a substituted or unsubstituted arylene group, Ar ² and Ar ⁶ represent a substituted or unsubstituted aryl group, and X and Y are substituents represented by the following general formula (2). Is shown below. Here, Ar ⁷ and Ar ⁸ represent a substituted or unsubstituted aryl group. R ¹ is a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted amino group, a lower alkoxy group having 1 to 6 carbon atoms which may have a substituent, or a 1 to carbon atom which may have a substituent. 6 represents a lower alkyl group. )