JPH05105645A - Stilbene derivative and electrophotographic sensitive material containing the same - Google Patents

Abstract

PURPOSE:To provide a stilbene derivative having excellent charge transfer capability and light stability and suitable as a charge transfer material for electrophotographic sensitive material having high sensitivity and excellent durability and usable in electrostatic copier, laser beam printer, etc. CONSTITUTION:The stilbene derivative of formula I [R<1> to R<3> are H, (substituted)alkyl, aryl or aralkyl; R<3> may be NH2], e.g. the compound of formula II. In the above compounds, the compound of formula Ia can easily be produced by reacting a compound of formula II (R<4> is 1-4C alkyl) with a compound of formula III in an organic solvent in the presence of a basic catalyst at room temperature to about 100 deg.C. Since the phenanthrene structure known as an extinction agent is introduced into the molecule of the objective compound, the compound has high charge transfer capability and excellent optical activity. Accordingly, an electrophotographic sensitive material having high sensitivity and excellent durability can be produced by forming a photosensitive layer containing the compound as a charge transfer material on an electrically conductive substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stilbene derivative suitable as a charge transport material in an electrophotographic photoreceptor used in an electrostatic copying machine, a laser beam printer, etc., and an electrophotographic photoreceptor using the same. It is a thing.

[0002]

2. Description of the Related Art In recent years, organic photoconductors are widely used as photoconductors in image forming apparatuses such as copying machines because they are excellent in processability and economy and have a high degree of freedom in functional design. The Carlson process is widely used to form a copied image using a photoconductor. The Carlson process consists of a charging process that uniformly charges the photoconductor by corona discharge, an exposure process that exposes the document image on the charged photoconductor to form an electrostatic latent image corresponding to the document image, and an electrostatic latent image. After development with a developer containing toner, a developing step of forming a toner image, a transfer step of transferring the toner image to paper, a fixing step of fixing the transferred toner image, and a transfer step,
And a cleaning step for removing the toner remaining on the photoconductor. In order to form a high-quality image in the Carlson process, the photoconductor is required to have excellent charging properties and photosensitivity, and to have a low residual potential after exposure.

Conventionally, inorganic photoconductors such as selenium and cadmium sulfide have been known as photosensitive materials, but they have the drawbacks of toxicity and high production cost. Therefore, so-called organic photoconductors using various organic substances in place of these inorganic substances have been proposed. Such an organophotoreceptor has a photosensitive layer composed of a charge generating material that generates a charge upon exposure and a charge transporting material that has a function of transporting the generated charge.

In order to satisfy various conditions desired for such an organic photoreceptor, it is necessary to appropriately select these charge generating material and charge transporting material. Various organic compounds such as carbazole compounds, oxadiazole compounds, pyrazoline compounds, hydrazone compounds, and stilbene compounds have been proposed as charge transport materials. Examples of the stilbene compound include compounds represented by the following formula (i).

[0005]

[Chemical 3]

[0006]

However, the above equation
Conventional charge-transporting materials such as stilbene compounds represented by (i) have the problems of insufficient charge-transporting ability and poor photostability. The photoconductor used has a drawback that the sensitivity and durability are not sufficient.

An object of the present invention is to provide a stilbene derivative having excellent charge transporting ability and photostability and suitable as a charge transporting material,
To provide an electrophotographic photosensitive member using the same, which has high sensitivity and excellent durability.

[0008]

The stilbene derivative of the present invention for solving the above-mentioned problems has the general formula
(I):

[0009]

[Chemical 4]

[In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, or an optionally substituted alkyl group, an aryl group or an aralkyl group, and R ³ is a hydrogen atom or a substituted group. The alkyl group, aryl group, aralkyl group and amino group which may have a group are shown. ] Is represented. The electrophotographic photosensitive member of the present invention for achieving the above object is characterized in that a photosensitive layer containing a stilbene derivative represented by the general formula (I) is provided on a conductive substrate.

The stilbene derivative represented by the above general formula (I) has a structure of phenanthrene known as a quencher introduced into the molecule, and therefore exhibits a high charge transporting ability and is excellent in photostability. .. Therefore, the photosensitive layer containing the stilbene derivative as a charge transport material,
It has high sensitivity and excellent durability. As described above, the reason why the stilbene derivative represented by the general formula (I) has high sensitivity and photostability is, for example, that a phenanthrene moiety is formed in comparison with the compound represented by the formula (i). It is presumed that this is because the π-electron conjugated system described above has a larger spread, so that the planarization of the molecular structure of the compound is further promoted and the intermolecular interaction due to the overlap between the molecules is strengthened.

The stilbene derivative represented by the general formula (I) basically contains the stilbene derivative represented by the following general formulas (Ia) and (Ib).

[0013]

[Chemical 5]

[In the formula, R ¹ , R ² and R ³ represent the same groups as described above. Examples of the alkyl group include lower alkyl groups having 1 to 6 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group and hexyl group. Examples of the aryl group include a phenyl group, an o-terphenyl group,
Examples thereof include naphthyl group, anthryl group and phenanthryl group.

Examples of the aralkyl group include benzyl group, α-phenethyl group, β-phenethyl group, 3-phenylpropyl group, benzhydryl group and trityl group. In addition, examples of the substituent that substitutes the above alkyl group and the like include a halogen atom, an amino group, a hydroxyl group, an optionally esterified carboxyl group, a cyano group, an alkyl group having 1 to 6 carbon atoms, and 1 to 6 carbon atoms. And an alkenyl group having 2 to 6 carbon atoms which may have an aryl group.

Specific compounds of the stilbene derivative represented by the general formula (I) include, for example, the following formulas (A1) to (A1
The items shown in 8) are listed.

[0017]

[Chemical 6]

[0018]

[Chemical 7]

[0019]

[Chemical 8]

[0020]

[Chemical 9]

[0021]

[Chemical 10]

[0022]

[Chemical 11]

The stilbene derivative of the present invention can be synthesized by various methods, for example, the above-mentioned general formula (Ia)
The stilbene derivative represented by, as shown in the following reaction formula, a phenanthrene derivative represented by the formula (a) and a formula (b)
It can be easily produced by reacting the aldehyde compound represented by the formula (1) with an organic solvent in the presence of a basic catalyst at a temperature from room temperature to about 100 ° C.

[0024]

[Chemical 12]

[In the formula, R ¹ , R ² and R ³ represent the same groups as described above, and R ⁴ represents a lower alkyl group having 1 to ⁴ carbon atoms. Examples of the basic catalyst used in the above reaction include caustic soda, caustic potash, sodium amide, sodium hydride, and alcoholates such as sodium methylate and potassium tert-butoxide.

As the organic solvent, methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, dioxane, tetrahydrofuran, toluene, xylene, dimethylsulfoxide, N,
N-dimethylformamide, N-methylpyrrolidone,
Examples thereof include 1,3-dimethyl-2-imidazolidinone. Among them, polar solvents such as N, N-dimethylformamide and dimethylsulfoxide are preferably used.

The reaction temperature is such that the solvent used is stable to the basic catalyst, the reactivity of the compound represented by the formula (a) or (b) as a condensation component, and the reaction of the basic catalyst as a condensation agent. It is selected in a wide range depending on the sex. For example, the reaction temperature when a polar solvent is used is from room temperature to 1
The temperature is set to 00 ° C, preferably room temperature to 80 ° C. The reaction temperature when using a basic catalyst having a short reaction time or low activity as a condensing agent is set to a temperature higher than the above.

The phenanthrene derivative represented by the above formula (a) is a corresponding haloalkyl compound and trialkyl phosphite (the alkyl group is preferably a lower alkyl group having 1 to 4 carbon atoms, particularly a methyl group or an ethyl group). .) And can be easily produced by heating with or in a solvent such as toluene or xylene. The photoreceptor of the present invention is provided with a photosensitive layer containing one or more stilbene derivatives represented by the above general formula (I) as a charge transport material.

The photosensitive layer is classified into a so-called single layer type and a laminated type, but the present invention is applicable to both of them. In order to obtain a single-layer type photoreceptor, a photosensitive layer containing a compound represented by the general formula (I), which is a charge transport material, a charge generating material, a binder resin, etc., is applied by means such as coating. It may be formed on the conductive substrate.

In order to obtain a laminated type photoreceptor, a charge generating layer containing a charge generating material is formed on a conductive substrate by means such as vapor deposition or coating, and on this charge generating layer,
A charge transport layer containing the compound represented by the general formula (I) and a binder resin may be formed. Also, contrary to the above,
The charge transport layer may be formed on the conductive substrate, and then the charge generation layer may be formed. Further, in the above-mentioned laminated type photosensitive layer, the charge generating layer may also contain a charge transport material.

As the charge generating material, conventionally used selenium, selenium-tellurium, selenium-arsenic, amorphous silicon, pyrylium salt, azo compounds, disazo compounds, phthalocyanine compounds, anthanthrone compounds, perylene compounds. Examples thereof include compounds, indigo compounds, triphenylmethane compounds, slene compounds, toluidine compounds, pyrazoline compounds, perylene compounds, quinacridone compounds, and pyrrolopyrrole compounds. These charge generation materials can be used alone or in combination of two or more so that they have an absorption wavelength region in a desired region.

The stilbene derivative represented by the general formula (I), which is a charge transport material, can be used alone or in combination with other conventionally known charge transport materials. As the conventionally known charge transport material, various electron-withdrawing compounds and electron-donating compounds can be used. Examples of the electron-withdrawing compound include 2,6-dimethyl-
Diphenoquinone derivatives such as 2 ', 6'-ditert-dibutyldiphenoquinone, malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, 3,4,5,7-tetranitro-9.
Examples include fluorenone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, succinic anhydride, maleic anhydride, and dibromomaleic anhydride.

As the electron donating compound, 2,5
-Oxadiazole compounds such as di (4-methylaminophenyl) and 1,3,4-oxadiazole, 9- (4
-Styryl compounds such as diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline, hydrazone compounds, triphenylamine compounds, indole compounds Examples thereof include nitrogen-containing cyclic compounds such as compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, and triazole compounds, and condensed polycyclic compounds.

These charge transport materials may be used alone or in combination of two or more. When a charge transporting material having film-forming property such as polyvinylcarbazole is used,
The binder resin is not always necessary. As a binder resin,
Various resins can be used. For example, styrene-based polymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer , Chlorinated polyethylene, polyvinyl chloride, polypropylene,
Thermoplastic resin such as vinyl chloride-vinyl acetate copolymer, polyester, alkyd resin, polyamide, polyurethane, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, or silicone resin, Examples thereof include epoxy resins, phenol resins, urea resins, melamine resins, other crosslinkable thermosetting resins, and photocurable resins such as epoxy acrylate and urethane-acrylate. These binder resins may be used alone or in combination of two or more.

Each of the single-layer type organic photosensitive layer and the laminated type organic photosensitive layer includes
A sensitizer, a fluorene compound, an antioxidant, a deterioration inhibitor such as an ultraviolet absorber, and an additive such as a plasticizer may be contained. Further, in order to improve the sensitivity of the charge generation layer, known sensitizers such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generation material.

In the multi-layer type photoconductor, the charge generating material and the binder resin constituting the charge generating layer can be used in various ratios, but to 100 parts of the binder resin (parts by weight, the same applies hereinafter). 5 to 500 parts, especially 10 to 10 parts of the charge generating material.
It is preferably used in a ratio of 300 parts. The charge generation layer may have an appropriate film thickness, but 0.01 to 5
It is preferably formed to a thickness of 0.1 μm, particularly 0.1 to 3 μm.

The stilbene derivative (charge-transporting material) represented by the general formula (I) constituting the charge-transporting layer and the binder resin may be mixed in various amounts within a range that does not hinder charge transport and a range that does not crystallize. The stilbene derivative represented by the above general formula (I) can be used in a proportion of 100 parts by weight of the binder resin so that the charges generated in the charge generation layer by light irradiation can be easily transported. ~ 500 parts, especially 25 ~
It is preferably used in a ratio of 200 parts. The thickness of the laminated photosensitive layer is about 0.01 to 5 μm for the charge generation layer,
Particularly, it is preferable that the thickness is about 0.1 to 3 μm,
The charge transport layer is preferably formed to have a thickness of 2 to 100 μm, particularly 5 to 50 μm.

In the single-layer type photoreceptor, the binder resin 10
The charge generating material is 0.1 to 50 parts relative to 0 parts, and more preferably 0.1.
5 to 30 parts, 40 to 200 parts, especially 50 to 10 parts by weight of the stilbene derivative (charge transport material) represented by the general formula (I).
Suitably 0 copy. The thickness of the single-layer type photosensitive layer is preferably 5 to 100 μm, particularly preferably 10 to 50 μm.

In the case of a single-layer type electrophotographic photosensitive member, between the conductive substrate and the photosensitive layer, in the case of the multilayer type photosensitive member, between the conductive substrate and the charge generating layer, Between the conductive substrate and the charge transport layer, or between the charge generation layer and the charge transport layer, a barrier layer may be formed to the extent that the characteristics of the photoreceptor are not impaired, and the surface of the photoreceptor is A protective layer may be formed.

As the conductive substrate on which the above layers are formed, various conductive materials can be used.
For example, simple metals such as aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass, plastic materials in which the above metals are vapor-deposited or laminated, and iodide Examples thereof include glass coated with aluminum, tin oxide, indium oxide, or the like.

The conductive substrate may be in the form of a sheet, a drum or the like, as long as the substrate itself has conductivity or the surface of the substrate has conductivity. Further, the conductive substrate is preferably one having sufficient mechanical strength when used. When each of the above layers is formed by a coating method, the charge generation material, charge transport material, and
A binder resin and the like are mixed with a suitable solvent by a known method, for example, a roll mill, a ball mill, an attritor, a paint shaker or an ultrasonic disperser to prepare a coating solution, which is prepared by a known means. It may be applied and dried.

As the solvent for forming the coating solution, various organic solvents can be used, for example, alcohols such as methanol, ethanol, isopropanol and butanol,
Aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, carbon tetrachloride and chlorobenzene, dimethyl ether, diethyl ether, tetrahydrofuran, Examples thereof include ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide and dimethyl sulfoxide. These solvents may be used alone or in combination of two or more.

Further, in order to improve the dispersibility and dyeing property of the charge transport material and the charge generating material, a surfactant, a leveling agent and the like may be used. As described above, the charge generation layer may be formed by depositing the charge generation material.

[0044]

The present invention will be described in detail below with reference to examples and comparative examples. Example 1 <Synthesis of Stilbene Derivative Represented by Formula (A1)> In the formula (a), 3.42 g (0.01 mol) of a phenanthrene derivative in which R ³ is a methyl group and R ⁴ is an ethyl group is used. And 2.73 g (0.01 mol) of an aldehyde compound in which R ¹ and R ² in the formula (b) are both phenyl groups,
Dissolved in 20 ml of dimethylformamide, potassium-
In the presence of 1.955 g of tert-butoxide, the liquid temperature was 22-
The mixture was kept at 32 ° C. and stirred for 5 hours to cause a reaction. Then, the reaction mixture was poured into ice water, the generated crystals were filtered, washed with water and methanol, and then dried to obtain 3.70 g (yield 80.2%) of the stilbene derivative represented by the formula (A1). It was

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis results Calculated as C ₃₅ H ₂₇ N ₁ (%): C 91.07 H: 5.90 N: 3.03 Measured value (%): C: 91.04 H: 5.90 N: 3. 04 Results of mass spectrometry m / e = 461 (calculated value 461.6) IR 955 cm ⁻¹ (HC = out-of-plane) Example 2 <Synthesis of stilbene derivative represented by the above formula (A2)> Used in Example 1 Instead of the phenanthrene derivative, the above formula
In the same manner as in Example 1, except that 4.03 g (0.01 mol) of a phenanthrene derivative in which R ^{3 in} (a) was a phenyl group and R ⁴ was an ethyl group was used, the above formula (A2) 4.13 g (yield 78.6) of the stilbene derivative represented by
%) Was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₀ H ₃₁ N ₁ : C: 91.39 H: 5.94 N: 2.66 Measured value (%): C: 91.35 H: 5.89 N: 2 .66 Mass spectrometry result m / e = 525 (calculated value 525.7) IR 955 cm ⁻¹ (HC = out-of-plane) Example 3 <Synthesis of stilbene derivative represented by the above formula (A3)> Used in Example 1 In place of the phenanthrene derivative
In the same manner as in Example 1 except that 4.34 g (0.01 mol) of a phenanthrene derivative in which R ^{3 in} (a) was a 4-methoxyphenyl group and R ⁴ was an ethyl group was used,
4.38 g (yield 79.0%) of the stilbene derivative represented by the formula (A3) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₁ H ₃₃ N ₁ O ₁ : C: 88.62 H: 5.99 N: 2.52 Measured value (%): C: 89.65 H: 6.05 N : 2.50 result of mass spectrometry m / e = 555 (calculated value 555.7) IR 955 cm ^-1 (HC = out-of-plane) Example 4 <Synthesis of stilbene derivative represented by the above formula (A4)> Example 1 In place of the phenanthrene derivative used in
R ^{3 in} (a) is a 4- (diethylamino) -phenyl group,
4.85 g of a phenanthrene derivative in which R ⁴ is an ethyl group
4.70 g (yield 78.8%) of the stilbene derivative represented by the formula (A4) was obtained in the same manner as in Example 1 except that (0.01 mol) was used.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₄ H ₄₀ N ₂ : C: 88.55 H: 6.76 N: 4.69 Measured value (%): C: 88.53 H: 6.76 N: 4 .69 mass spectrometry result m / e = 596 (calculated value 596.8) IR 955 cm ⁻¹ (HC = out-of-plane) Example 5 <Synthesis of stilbene derivative represented by the above formula (A5)> Used in Example 1 In place of the phenanthrene derivative
In the same manner as in Example 1 except that 4.18 g (0.01 mol) of a phenanthrene derivative in which R ^{3 in} (a) was a benzyl group and R ⁴ was an ethyl group was used, the above formula (A5) 3.68 g (yield 76.9) of the stilbene derivative represented by
%) Was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₃ N ₁ : C: 90.15 H: 6.93 N: 2.92 Actual value (%): C: 90.21 H: 6.86 N: 2 .89 mass spectrometry result m / e = 479 (calculated value 479.7) IR 955 cm ⁻¹ (HC = out-of-plane) Example 6 <Synthesis of stilbene derivative represented by the above formula (A6)> Used in Example 1 In place of the phenanthrene derivative
In the same manner as in Example 1 except that 4.18 g (0.01 mol) of a phenanthrene derivative in which R ^{3 in} (a) was a 4-methylphenyl group and R ⁴ was an ethyl group was used,
3.94 g (yield 82.3%) of the stilbene derivative represented by the formula (A6) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₃ N ₁ : C: 90.15 H: 6.93 N: 2.92 Measured value (%): C: 90.16 H: 6.95 N: 2 .87 mass spectrometry result m / e = 479 (calculated value 479.7) IR 955 cm ⁻¹ (HC = out-of-plane) Example 7 <Synthesis of stilbene derivative represented by the above formula (A7)> Used in Example 1 In place of the aldehyde compound
In the same manner as in Example 1 above, except that 2.11 g (0.01 mol) of an aldehyde compound in which R ¹ is a methyl group and R ² is a phenyl group was used, the compound represented by the above formula (A7) was used. A stilbene derivative (3.28 g, yield 81.9%) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₀ H ₂₇ N ₁ : C 89.73 H: 6.78 N: 3.49 Measured value (%): C: 89.77 H: 6.73 N: 3. 49 Mass spectrometry result m / e = 401 (calculated value 401.6) IR 955 cm ⁻¹ (HC = out-of-plane) Example 8 <Synthesis of stilbene derivative represented by the above formula (A8)> Used in Example 2 Instead of the aldehyde compound, the above formula (b)
Represented by the above formula (A8) in the same manner as in Example 2 except that 2.11 g (0.01 mol) of the aldehyde compound in which R ¹ was a methyl group and R ² was a phenyl group was used. The stilbene derivative 3.73 g (yield 80.6%) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₅ H ₂₉ N ₁ : C: 90.67 H: 6.30 N: 3.02 Measured value (%): C: 90.63 H: 6.22 N: 3 .04 mass spectrometry result m / e = 463 (calculated value 463.6) IR 955 cm ⁻¹ (HC = out-of-plane) Example 9 <Synthesis of stilbene derivative represented by the above formula (A9)> Used in Example 3 In place of the aldehyde compound
Represented by the above formula (A9) in the same manner as in Example 3 except that 2.11 g (0.01 mol) of an aldehyde compound in which R ¹ is a methyl group and R ² is a phenyl group was used. To obtain 3.97 g (yield 80.5%) of the stilbene derivative.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₁ N ₁ O ₁ : C: 87.59 H: 6.33 N: 2.84 Measured value (%): C: 87.57 H: 6.41 N : 2.84 Mass spectrometry result m / e = 493 (calculated value 493.7) IR 955 cm ^-1 (HC = out-of-plane) Example 10 <Synthesis of stilbene derivative represented by the formula (A10)> Example 4 In place of the aldehyde compound used in
In the same manner as in Example 4 except that 2.11 g (0.01 mol) of the aldehyde compound in which R ^{1 in} (b) is a methyl group and R ² is a phenyl group was used, the above formula (A10) 4.25 g of stilbene derivative represented by (yield 79.6%)
Got

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₉ H ₃₈ N ₂ : C: 87.60 H: 7.16 N: 5.24 Measured value (%): C: 87.61 H: 7.18 N: 5 .20 mass spectrometry result m / e = 534 (calculated value 534.8) IR 955 cm ⁻¹ (HC = out-of-plane) Example 11 <Synthesis of stilbene derivative represented by the above formula (A11)> Used in Example 5 In place of the aldehyde compound
In the same manner as in Example 5 except that 2.11 g (0.01 mol) of an aldehyde compound in which R ^{1 in} (b) is a methyl group and R ² is a phenyl group was used, the above formula (A11) 3.72 g of the stilbene derivative represented by (yield 78.0%)
Got

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₁ N ₁ : C: 90.53 H: 6.54 N: 2.93 Measured value (%): C: 90.56 H: 6.50 N: 2 .94 mass spectrometry result m / e = 477 (calculated value 477.7) IR 955 cm ⁻¹ (HC = out-of-plane) Example 12 <Synthesis of stilbene derivative represented by the above formula (A12)> Used in Example 6 In place of the aldehyde compound
In the same manner as in Example 6 except that 2.11 g (0.01 mol) of the aldehyde compound in which R ^{1 in} (b) is a methyl group and R ² is a phenyl group was used, the above formula (A12) 3.70 g of stilbene derivative represented by (yield 77.6%)
Got

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₁ N ₁ : C: 90.53 H: 6.54 N: 2.93 Measured value (%): C: 90.58 H: 6.51 N: 2 .92 mass spectrometry result m / e = 477 (calculated value 477.7) IR 955 cm ⁻¹ (HC = out-of-plane) Example 13 <Synthesis of stilbene derivative represented by the above formula (A13)> Used in Example 1 In place of the phenanthrene derivative described above, 3.42 g (0.01 mol) of a phenanthrene derivative in which R ³ in the following formula (d) was a methyl group and R ⁴ was an ethyl group was used, and Similarly, the above formula (A13)
3.62 g of stilbene derivative represented by (yield 78.6
%) Was obtained.

[0057]

[Chemical 13]

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₅ H ₂₇ N ₁ : C 91.07 H: 5.90 N: 3.03 Measured value (%): C: 91.09 H: 5.88 N: 3. 03 Mass spectrometry result m / e = 461 (calculated value 461.6) IR 970 cm ⁻¹ (HC = out-of-plane) Example 14 <Synthesis of stilbene derivative represented by the formula (A14)> Used in Example 13. The same as in Example 13 except that 4.04 g (0.01 mol) of a phenanthrene derivative in which R ³ in the formula (d) was a phenyl group and R ⁴ was an ethyl group was used in place of the phenanthrene derivative. And then the formula
4.21 g of stilbene derivative represented by (A14) (yield 8
0.2%) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₀ H ₃₁ N ₁ : C: 91.39 H: 5.94 N: 2.66 Measured value (%): C: 91.35 H: 5.90 N: 2 .70 mass spectrometry result m / e = 525 (calculated value 525.7) IR 970 cm ⁻¹ (HC = out-of-plane) Example 15 <Synthesis of stilbene derivative represented by the above formula (A15)> Used in Example 13 In place of the phenanthrene derivative described above, 4.34 g (0.0%) of a phenanthrene derivative in which R ³ in the formula (d) is a 4-methoxyphenyl group and R ⁴ is an ethyl group.
(1 mol) except that the stilbene derivative 4.4 represented by the formula (A15) was used in the same manner as in Example 13 above.
9 g (yield 80.9%) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₁ H ₃₃ N ₁ O ₁ : C: 88.62 H: 5.97 N: 2.52 Measured value (%): C: 88.60 H: 6.00 N : 2.51 mass spectrometry result m / e = 555 (calculated value 555.7) IR 970 cm ^-1 (HC = out-of-plane) Example 16 <Synthesis of stilbene derivative represented by the above formula (A16)> Example 13 A phenanthrene derivative in which R ³ in the formula (d) is a 4- (diethylamino) -phenyl group and R ⁴ is an ethyl group in place of the phenanthrene derivative used in 4.8.
4.72 g (yield 79.2%) of the stilbene derivative represented by the formula (A16) was obtained in the same manner as in Example 13 except that 5 g (0.01 mol) was used.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₄₄ H ₄₀ N ₂ : C: 88.55 H: 6.76 N: 4.69 Measured value (%): C: 88.53 H: 6.70 N: 4 .72 mass spectrometry result m / e = 596 (calculated value 596.8) IR 970 cm ⁻¹ (HC = out-of-plane) Example 17 <Synthesis of stilbene derivative represented by the above formula (A17)> Used in Example 13 Example 13 except that 4.18 g (0.01 mol) of the phenanthrene derivative in which R ³ in the formula (d) is a benzyl group and R ⁴ is an ethyl group is used in place of the phenanthrene derivative described above. Similarly, the above formula
3.82 g of stilbene derivative represented by (A17) (yield 7
9.8%).

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₃ N ₁ : C: 90.15 H: 6.93 N: 2.92 Measured value (%): C: 90.11 H: 6.96 N: 2 .94 mass spectrometry result m / e = 479 (calculated value 479.7) IR 970 cm ⁻¹ (HC = out-of-plane) Example 18 <Synthesis of stilbene derivative represented by the above formula (A18)> Used in Example 13 In place of the phenanthrene derivative, the phenanthrene derivative in which R ³ in the formula (d) is a 4-methylphenyl group and R ⁴ is an ethyl group is 4.18 g (0.01
The same procedure as in Example 13 except that the stilbene derivative 3.86 represented by the formula (A18) was used.
g (yield 80.6%) was obtained.

The analysis results of the obtained stilbene derivative are shown below. Elemental analysis result Calculated value (%) as C ₃₆ H ₃₃ N ₁ : C: 90.15 H: 6.93 N: 2.92 Measured value (%): C: 90.20 H: 6.88 N: 2 .93 mass spectrometric result m / e = 479 (calculated value 479.7) IR 970 cm ⁻¹ (HC = out-of-plane) Examples 19 to 30 and Comparative Examples 1 and 2 (multilayer photoreceptor) In the following formula (A) 2 parts of the charge generation material shown, 1 part of polyvinyl butyral resin, and 120 parts of tetrahydrofuran were dispersed for 2 hours with a paint shaker using glass beads (2 mm diameter). The obtained dispersion was applied on the surface of an aluminum tube by a dipping method and dried at 100 ° C. for 1 hour to obtain a 0.5 μm charge generation layer.

[0064]

[Chemical 14]

A solution prepared by dissolving 1 part of the charge transport material and 1 part of the polyester resin in 9 parts of toluene was applied on the charge generation layer by a dipping method and dried at 100 ° C. for 1 hour to form a 22 μm charge transport layer. Obtained. The charge transport materials used are shown in Table 1 by the numbers of the compounds of formulas (A1) to (A18) in the above-mentioned specific examples. Comparative Example 1 uses the compound represented by the above formula (i), and Comparative Example 2 uses the compound represented by the following formula (ii) as the charge transport material.
In the same manner as above, a laminated type photoreceptor was prepared.

[0066]

[Chemical 15]

Examples 31 to 42 and Comparative Examples 3 and 4 (single
( Layered Photoreceptor) 1 part of the charge generating agent represented by the formula (A) and 60 parts of tetrahydrofuran were dispersed in a paint shaker using glass beads (2 mm diameter) for 2 hours. To the obtained dispersion liquid, tetrahydrofuran solution of polyester resin 50
Parts and 10 parts of charge transport material were added and dispersion was continued for another hour. The obtained dispersion was applied on the surface of an aluminum tube by a dipping method to obtain a photosensitive layer of 20 μm. The charge transport materials used are shown in Table 2 by the numbers of the compounds of formulas (A1) to (A18) shown in the above-mentioned specific examples.

Comparative Example 3 uses the compound represented by the above formula (i), and Comparative Example 4 uses the compound represented by the above formula (ii) as the charge transport material.
A single-layer type photosensitive member was prepared in the same manner as described above. The following tests were carried out on the electrophotographic photosensitive members of the above Examples and Comparative Examples to evaluate their characteristics.

Measurement of Initial Surface Potential Each electrophotographic photosensitive member was loaded into an electrostatic copying tester (Gentec Cynthia 30M, trade name, manufactured by Gentech), and its surface was charged positively or negatively to initialize. The surface potential Vs.p. (V) was measured. Measurement of half-exposure amount and residual potential The electrophotographic photosensitive member charged in the above-mentioned measurement of the initial surface potential is exposed under a condition of an exposure intensity of 10 lux by using a halogen lamp which is an exposure light source of an electrostatic copying tester. do it,
The half-exposure amount E1 / 2 (lux.sec) was calculated by obtaining the time until the surface potential became 1/2.

The surface potential was measured at 0.15 seconds after the start of the exposure, and the residual potential V1r.p. (V) was measured.
And Measurement of Light Stability The electrophotographic photosensitive member was loaded in an electrostatic copying machine (model number DC-111 manufactured by Mita Kogyo Co., Ltd.) to continuously copy 1000 sheets, and then repeatedly exposed in the same manner as above. After that, the residual potential V2r.p. (V) was measured. Then, the residual potential V
The difference ΔVr.p. (V) between 1r.p. and V2r.p. was obtained.

The test results of the laminated type photoconductors (Examples 19 to 30 and Comparative Examples 1 and 2) are shown in Table 1, and the test results of the single layer type photoconductors (Examples 31 to 42 and Comparative Examples 3 and 4) are shown. Each is shown in Table 2.

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[Table 1]

[0073]

[Table 2]

From these test results, there is almost no difference in the surface potential VS.P. between the photoconductors of the respective examples, that is, the laminated type and the single layer type, as compared with the conventional photoconductor of the comparative example. ,
It was found that the sensitivity was remarkably improved because the half exposure amount E1 / 2 was small and the residual potential V1r.p. was low. In addition, the photoconductors of the above respective examples have Δ
Since the Vr.p. was small, it was found that each of them had excellent durability.

[0075]

Industrial Applicability As described above, the stilbene derivative of the present invention has a high charge-transporting ability and is excellent in photostability. Therefore, by using this stilbene derivative as a charge-transporting material, high sensitivity can be obtained. And an electrophotographic photoreceptor having excellent durability can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Mizuta 1-2-2 Tamatsukuri Chuo-ku, Osaka City, Osaka Prefecture Mita Industry Co., Ltd.

Claims (2)

[Claims] 1. General formula (I): [In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, or an optionally substituted alkyl group, an aryl group or an aralkyl group, and R ³ is a hydrogen atom, or
The alkyl group, aryl group, aralkyl group and amino group which may have a substituent are shown. ] The stilbene derivative represented by these. 2. On a conductive substrate, the following general formula (I): [In the formula, R ¹ and R ² are the same or different and each represents a hydrogen atom, or an optionally substituted alkyl group, an aryl group or an aralkyl group, and R ³ is a hydrogen atom, or
The alkyl group, aryl group, aralkyl group and amino group which may have a substituent are shown. ] The electrophotographic photoreceptor provided with the photosensitive layer containing the stilbene derivative represented by these.