JPH05301876A - New pyrene-based compound and its production and electrophotographic receptor containing the same - Google Patents

Abstract

PURPOSE:To provide the subject compound useful as an organic photoconductive compound. CONSTITUTION:The objective compound of formula I, II, III or IV [X is (substituted divalent aromatic ring; R1 to R6 are each H, halogen, alkyl, etc.], e.g. bis(benzimidazole)diphenylpyrene. The present compound can be obtained, for example, by reaction of a pyrene-1,2,6,7-tetracarboxylic adianhydride derivative of formula V with a diamino compound of formula VI pref. at a molar ratio of (1:2) to (1:3) in an inert high-boiling solvent (pref. N-methylpyrrolidone) in the presence of a dehydrating catalyst (e.g. anhydrous zinc chloride) under agitation at 150-250 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel pyrene compound, a method for producing the same, and an electrophotographic photoreceptor containing the same.

[0002]

2. Description of the Related Art In recent years, photoconductive materials have been actively researched and applied to photoelectric conversion elements such as electrophotographic photoreceptors, solar cells and image sensors. Conventionally, inorganic materials have been mainly used as these photoconductive materials. For example, in electrophotographic photoreceptors, inorganic photoreceptors provided with a photosensitive layer containing an inorganic photoconductive material such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used. However, such an inorganic photoreceptor has a photosensitivity required as an electrophotographic photoreceptor of a copying machine,
The properties such as thermal stability, moisture resistance, and durability were not always satisfactory. For example, selenium is crystallized by heat, stains on fingerprints, etc., so that the characteristics as an electrophotographic photoreceptor are likely to deteriorate. Further, the electrophotographic photoreceptor using cadmium sulfide is inferior in moisture resistance and durability, and the electrophotographic photoreceptor using zinc oxide also has a problem in durability. Further, in recent years, environmental problems have been particularly emphasized, but electrophotographic photoconductors of selenium and cadmium sulfide have a drawback that there are great restrictions in production and handling in terms of toxicity.

In order to improve the drawbacks of such inorganic photoconductive substances, various organic photoconductive substances have been attracting attention, and it has been attempted to use them in the photosensitive layer of electrophotographic photoreceptors. Active research is being conducted. For example,
No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing polyvinylcarbazole and trinitrofluorenone. However, this photoreceptor is not sufficient in sensitivity and durability. Therefore, a function-separated type electrophotographic photosensitive member has been developed in which different substances have a carrier generating function and a carrier transporting function. In such an electrophotographic photosensitive member, since each material can be selected in a wide range, it is expected that an organic photosensitive member excellent in high sensitivity and high durability can be easily obtained with arbitrary characteristics.

[0004]

Various organic compounds have been proposed as a carrier-generating substance and a carrier-transporting substance for such a function-separated type electrophotographic photoreceptor, and as a carrier-generating substance, dibromoanthanthrone has been proposed so far. Typified by polycyclic quinone compounds, pyrylium compounds and eutectic complexes of pyrylium compounds, squarylium compounds,
Photoconductive substances such as phthalocyanine compounds and azo compounds have been put to practical use.

For example, as electrophotographic photoreceptors containing a polycyclic quinone compound in the photosensitive layer, there are disclosed in Japanese Patent Laid-Open Nos. 49-76933 and 50-76933.
-75042, 63-180955 and the like are already known. However, these compounds are not necessarily satisfactory in characteristics such as sensitivity, and do not sufficiently satisfy a wide range of requirements for electrophotographic processes, such as a limited selection range of carrier transport substances.

[0006]

OBJECT OF THE INVENTION It is an object of the present invention to provide a pyrene compound which is particularly useful as an organic photoconductive compound, a method for producing the same, and an electrophotographic photoreceptor containing the same.

[0007]

The pyrene compound of the present invention is a compound represented by the following general formula [1], [2], [3] or [4].

[0008]

[Chemical 5]

However, in the formula, X represents a substituted or unsubstituted divalent aromatic ring, R _{1 to} R ₆ are hydrogen atoms, halogen atoms,
It represents an alkyl group, an alkoxy group, an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue.

Preferred as X is a benzene ring,
Examples thereof include naphthalene ring, anthracene ring, phenanthrene ring, pyridine ring, pyrimidine ring, and anthraquinone ring, and particularly preferred are benzene ring and naphthalene ring. The substituent of X is alkyl, alkoxy, aryl, aryloxy, acyl, acyloxy, amino,
Examples thereof include carbamoyl, halogen, nitro, cyano and the like. Further, as R ₁ and R ₄ , a substituted or unsubstituted aromatic ring residue is preferable, and a substituted or unsubstituted phenyl group is more preferable. As R ₂ , R ₃ , R ₅ and R ₆ , a hydrogen atom and a halogen atom are preferable.

Furthermore, another pyrene compound of the present invention is a compound represented by the following general formula [5].

[0012]

[Chemical 6]

However, in the formula, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic residue, and R _{1 to} R ₆ are a hydrogen atom, a halogen atom, an alkyl group,
It represents an alkoxy group, an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue. Preferred examples of R include a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms and a substituted or unsubstituted phenyl group. Substituents on the alkyl group include hydroxy, alkoxy,
Aryl, aryloxy, acyl, acyloxy and the like can be mentioned. Substituents on the phenyl group include alkyl, alkoxy, aryl, aryloxy, acyl,
Examples include acyloxy, amino, carbamoyl, halogen, nitro, cyano and the like.

As R ₁ and R ₄ , a substituted or unsubstituted aromatic ring residue is preferable, and a substituted or unsubstituted phenyl group is more preferable. As R ₂ , R ₃ , R ₅ and R ₆ , a hydrogen atom and a halogen atom are preferable.

The pyrene compound represented by the general formula [1], [2], [3] or [4] is a pyrene-1,2,6,7-tetracarboxylic acid represented by the general formula [6]. It is produced by subjecting a dianhydride derivative and a diamino compound represented by the general formula [7] to a dehydration condensation reaction. The pyrene compound represented by the general formula [1], [2], [3] or [4] is a structural isomer and can be produced as a mixture in the above condensation reaction, but these are not isolated. Can be used.

[0016]

[Chemical 7]

In the general formula [6], R _{1 to} R ₆ are the same as in the general formula [1], [2], [3] or [4].

X in the general formula [7] is the same as in the general formula [1], [2], [3] or [4].

The pyrene-based compound represented by the general formula [5] includes the pyrene-1,2,6,7-tetracarboxylic dianhydride derivative represented by the general formula [6] and the general formula [8]. ] It manufactures by performing the dehydration condensation reaction of the amino compound represented by these.

R in the general formula [8] is the same as that in the general formula [5].

The above production synthesis is carried out in a non-reactive high boiling point solvent, preferably N-methylpyrrolidone, N, N-dimethylformamide, quinoline, α-chlornaphthalene solvent, pyrene-1,2,6,7-. The tetracarboxylic dianhydride derivative and various diamino compounds or amino compounds are mixed in a ratio of 1: 2 to 1:
10 Mixing is carried out at a molar ratio of preferably 1: 2 to 1: 3, and stirring is carried out at a temperature of 150 to 250 ° C. Also, a dehydration catalyst such as anhydrous zinc chloride, anhydrous zinc acetate, acetic acid, hydrochloric acid can be used to increase the reaction rate. It is effective to use the catalyst in an amount of about 0.01 to about 2 mol per mol of acid anhydride.

The starting compound of the present invention, pyrene-1,2,6,7
-The tetracarboxylic dianhydride derivative can be obtained by a known method, for example, Tetrahedron, Vol. 30, page 3293 (1974).
Can be obtained by the method described in.

The pyrene compounds of the present invention thus obtained are exemplified below, but the present invention is not limited to these exemplified compounds.

[0024]

[Chemical 8]

[0025]

[Chemical 9]

[0026]

[Chemical 10]

[0027]

[Chemical 11]

[0028]

[Chemical 12]

[0029]

[Chemical 13]

[0030]

[Chemical 14]

[0031]

[Chemical 15]

[0032]

[Chemical 16]

[0033]

[Chemical 17]

[0034]

[Chemical 18]

[0035]

[Chemical 19]

[0036]

[Chemical 20]

[0037]

[Chemical 21]

[0038]

[Chemical formula 22]

[0039]

[Chemical formula 23]

[0040]

[Chemical formula 24]

The case where the pyrene compound of the present invention is used in an electrophotographic photoreceptor will be described below.

Various forms of the photoreceptor are known. The photoconductor of the present invention may take any of these forms, but it is preferable to use a laminated or dispersed function-separated photoconductor. In this case, normally, FIG.
The configuration is as shown in (6). In the layer structure shown in FIG. 1A, a carrier generation layer 2 is formed on a conductive support 1, a carrier transport layer 3 is laminated on the carrier generation layer 2, and a photosensitive layer 4 is formed. () Is a photosensitive layer 4'in which the carrier generating layer 2 and the carrier transporting layer 3 are reversed. FIG. 3C shows an intermediate layer 5 provided between the photosensitive layer 4 having the layer structure shown in FIG. 1A and the conductive support 1, and FIG. 4C shows the photosensitive layer having the layer structure shown in FIG. 2B. An intermediate layer 5 is provided between 4'and the conductive support 1. The layer structure of FIG. 5 (5) is formed by forming a photosensitive layer 4 ″ containing a carrier generating substance 6 and a carrier transporting substance 7, and FIG. 6 (6) shows such a photosensitive layer 4 ″ and a conductive support. The intermediate layer 5 is provided between the first and second layers.

In the present invention, other carrier generating substances may be used in combination with the above pyrene compounds. Examples of such carrier-generating substances include phthalocyanine pigments, azo pigments,
Anthraquinone pigment, perylene pigment, polycyclic quinone pigment,
Squarium pigment and the like can be mentioned.

As the carrier-transporting substance in the photoreceptor of the present invention, various substances can be used, but typical examples thereof include nitrogen-containing complex represented by oxazole, oxadiazole, thiazole, thiadiazole, imidazole and the like. Compounds having a ring nucleus and condensed ring nuclei thereof, polyarylalkane compounds, pyrazoline compounds, hydrazone compounds, triarylamine compounds, styryl compounds, styryltriphenylamine compounds,
Examples include β-phenylstyryltriphenylamine compounds, butadiene compounds, hexatriene compounds, carbazole compounds, condensed polycyclic compounds, and the like.

Specific examples of these carrier-transporting substances include the carrier-transporting substances described in JP-A-61-107356. The structures of typical ones are shown below.

[0046]

[Chemical 25]

[0047]

[Chemical formula 26]

[0048]

[Chemical 27]

[0049]

[Chemical 28]

[0050]

[Chemical 29]

The carrier generating layer is formed by coating a liquid in which the carrier generating substance is dispersed alone or in the form of fine particles together with a binder and an additive in a suitable dispersion medium, or by vacuum depositing the carrier generating substance. In the former case,
As a dispersing means, an ultrasonic dispersing machine, a ball mill, a sand mill, a homomixer or the like can be used. For the carrier transport layer, a method of applying a carrier transport substance alone or a solution in which a carrier transport substance is dissolved together with a binder and an additive is effective.

A wide variety of solvents or dispersion media can be used as the solvent or dispersion medium for forming the photosensitive layer. For example, butylamine, ethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, ethylene glycol dimethyl ether, toluene,
Examples thereof include xylene, acetophenone, chloroform, dichloromethane, dichloroethane, trichloroethane, methanol, ethanol, propanol, butanol and the like.

When a binder is used for forming the carrier generating layer or the carrier transporting layer, any binder can be selected, but a high molecular polymer having hydrophobicity and film forming ability is particularly desirable. Examples of such a polymer include the following,
It is not limited to these.

Polycarbonate Polycarbonate Z
Resin Acrylic resin Methacrylic resin Polyvinyl chloride Polyvinylidene chloride Polystyrene Styrene-butadiene copolymer Polyvinyl acetate Polyvinyl formal Polyvinyl butyral Polyvinyl acetal Polyvinyl carbazole Styrene-alkyd resin Silicone resin Silicone-alkyd resin Polyester phenol resin Polyurethane epoxy resin Vinylidene chloride-acrylonitrile co Polymer Vinyl chloride-vinyl acetate copolymer Vinyl chloride-vinyl acetate-maleic anhydride copolymer The ratio of carrier generation material to binder is 10 to 600 wt.
% Is preferable, and 50 to 400 wt% is more preferable. The ratio of the carrier transport material to the binder is preferably 10 to 500 wt%. The thickness of carrier generation layer is 0.01 ~ 20
μm, and more preferably 0.05 to 5 μm. The thickness of the carrier transport layer is 1 to 100 μm, and further 5 to
30 μm is preferred.

The photosensitive layer may contain an electron-accepting substance for the purpose of improving sensitivity, reducing residual potential, or reducing fatigue during repeated use. Examples of such electron-accepting substances include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride. Acid, pyromellitic dianhydride, mellitic dianhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, p-nitrobenzonitrile, picryl chloride, Quinone chlorimide, chloranil, bromanil, dichlorodicyano-p-
Benzoquinone, anthraquinone, dinitroanthraquinone, 9-fluorenylidene malonodinitrile, polynitro-9-fluorenylidene malonodinitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, Examples include pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, meritic acid, and other compounds having a high electron affinity. The addition ratio of the electron-accepting substance is preferably 0.01 to 200, more preferably 0.1 to 100, based on 100 by weight of the carrier generating substance.

Further, in the above-mentioned photosensitive layer, storability, durability,
For the purpose of improving the resistance to environment, a deterioration inhibitor such as an antioxidant or a light stabilizer can be contained. Examples of the compound used for such a purpose include chromanol derivatives such as tocopherol and its etherified compounds or esterified compounds, polyarylalkane compounds, hydroquinone derivatives and their mono- and dietherified compounds, benzophenone derivatives, benzotriazole derivatives and thioethers. Compounds, phosphonates, phosphites, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds, cyclic amine compounds, hindered amine compounds and the like are effective. Specific examples of particularly effective compounds include "IR
Hindered phenolic compounds such as "GANOX 1010", "IRGANOX 565" (manufactured by Ciba-Geigy), "Sumilyzer BHT", "Sumilyzer MDP" (manufactured by Sumitomo Chemical Co., Ltd.),
Examples thereof include hindered amine compounds such as "Sanol LS-2626" and "Sanol LS-622LD" (manufactured by Sankyosha).

As the binder used for the intermediate layer, the protective layer and the like, those mentioned above for the carrier generating layer and the carrier transporting layer can be used. In addition, polyamide resin, nylon resin, ethylene-vinyl acetate Polymer, ethylene-vinyl acetate-maleic anhydride copolymer,
Ethylene resins such as ethylene-vinyl acetate-methacrylic acid copolymers, polyvinyl alcohol, cellulose derivatives and the like are effective.

As the conductive support, a metal plate or a metal drum may be used, or a conductive polymer, a conductive compound such as indium oxide, or a thin layer of a metal such as aluminum or palladium may be applied, vapor deposited, laminated, or the like. What is provided on a substrate such as paper or plastic film by means can be used.

[0059]

EXAMPLES Examples will be shown below, but the present invention is not limited thereto.

Example 1 2.5 g (0.005 mol) of 3,8-diphenylpyrene-1,2,6,7-tetracarboxylic dianhydride and 1.6 g of o-phenylenediamine
(0.015 mol) and anhydrous zinc chloride 0.1 g (0.001 mol) were heated under reflux in 50 ml of quinoline for 2 hours, and the precipitated crystals were collected by filtration. Washed with acetone and methanol, then dried to 2.8g
(88%) product was obtained. This was purified by sublimation. The infrared absorption spectrum is shown in FIG. Raw acid anhydride ν = 184
Due to the disappearance of the infrared absorption at ⁰ , 1770 cm ⁻¹ and the appearance of a new infrared absorption at ν = 1740 cm ⁻¹ , and the molecular ion peak (m / e = 638) of the FD-mass spectrum, bis (benzimidazole) ) Diphenylpyrene (Exemplified Compound No. 4
It was confirmed that 1) was synthesized. It is believed to be a mixture of the three structural isomers shown below.

[0061]

[Chemical 30]

Examples 2 to 5 Various pyrene compounds were produced in the same manner as in Example 1 except that o-phenylenediamine in Example 1 was changed to the diamino compound shown in Table 1. The results are shown in Table 1. In addition, the infrared absorption spectra of these pyrene compounds are shown in FIGS.
Shown in.

[0063]

[Table 1]

Examples 6 to 10 Various pyrene compounds were produced in the same manner as in Example 1 except that o-phenylenediamine in Example 1 was replaced with the amino compound shown in Table 2. The results are shown in Table 2. The infrared absorption spectra of these pyrene compounds are shown in FIGS.

[0065]

[Table 2]

Example 11 The pyrene compound of Compound No. 41 obtained in Example 1 was
0.5 on aluminum-deposited polyester film
It was vacuum-deposited to a thickness of μm to form a carrier generation layer. On top of that, 1 part of carrier transport material T-20 and polycarbonate resin "Iupilon Z-200" (manufactured by Mitsubishi Gas Chemical Co., Inc.)
A solution prepared by dissolving 1.3 parts and a minute amount of silicone oil "KF-54" (manufactured by Shin-Etsu Chemical Co., Ltd.) in 10 parts of 1,2-dichloroethane was applied using a blade coating machine, and after drying, the film thickness was 20 μm.
Was formed into a carrier transport layer. The photoreceptor thus obtained was evaluated as follows using a paper analyzer EPA-8100 (manufactured by Kawaguchi Denki KK). First, -6k
Corona charging for 5 seconds at V, surface potential V immediately after charging
The surface potential Vi after being left for a and 5 seconds was determined, and then exposure was performed so that the surface illuminance was 8.2 lux. Surface potential is 1
Exposure amount E _1/2 , D = 100 (Va-
The dark decay rate D was calculated from the formula Vi) / Va. The results are shown in Table 3.
Shown in.

Examples 12 to 16 Table 3 shows the pyrene compounds of Compound No. 41 in Example 11.
A photoconductor was prepared in the same manner as in Example 11 except that the pyrene compound was used instead. This was evaluated in the same manner as in Example 11. The results are shown in Table 3.

Comparative Example (1) Example except that the pyrene compound of Compound No. 41 in Example 11 was changed to the perinone compound represented by G-1 below.
A photoconductor was prepared in the same manner as 11. This was evaluated in the same manner as in Example 11. The results are shown in Table 3.

Comparative Example (2) Example except that the pyrene compound of Compound No. 41 in Example 11 was changed to the perinone compound represented by G-2 below.
A photoconductor was prepared in the same manner as 11. This was evaluated in the same manner as in Example 11. The results are shown in Table 3.

[0070]

[Chemical 31]

[0071]

[Table 3]

[0072]

INDUSTRIAL APPLICABILITY The pyrene compound of the present invention can be easily produced and is extremely useful as a photoconductive compound as is clear from the examples.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a specific example of the layer structure of a photoconductor of the present invention.

FIG. 2 is an infrared spectrum diagram of the pyrene compound obtained in Example 1 by a KBr tablet method.

FIG. 3 is an infrared spectrum diagram of the pyrene compound obtained in Example 2 by a KBr tablet method.

FIG. 4 is an infrared spectrum diagram of the pyrene compound obtained in Example 3 by a KBr tablet method.

FIG. 5 is an infrared spectrum diagram of the pyrene compound obtained in Example 4 measured by a KBr tablet method.

FIG. 6 is an infrared spectrum diagram of the pyrene compound obtained in Example 5 by a KBr tablet method.

FIG. 7 is an infrared spectrum diagram of the pyrene compound obtained in Example 6 by a KBr tablet method.

FIG. 8 is an infrared spectrum diagram of the pyrene compound obtained in Example 7 by a KBr tablet method.

FIG. 9 is an infrared spectrum diagram of the pyrene compound obtained in Example 8 by a KBr tablet method.

FIG. 10 KBr of the pyrene-based compound obtained in Example 9
Infrared spectrum by the tablet method

FIG. 11: KBr of the pyrene compound obtained in Example 10
Infrared spectrum by the tablet method

[Explanation of symbols]

 1 Conductive Support 2 Carrier Generation Layer 3 Carrier Transport Layer 4, 4 ', 4 "Photosensitive Layer 5 Intermediate Layer

Claims (6)

[Claims] 1. A pyrene compound represented by the general formula [1], [2], [3] or [4]. [Chemical 1] [In the formula, X represents a substituted or unsubstituted divalent aromatic ring, R _{1 to} R ₆ are a hydrogen atom, a halogen atom, an alkyl group,
It represents an alkoxy group, an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue. ] 2. A pyrene compound represented by the general formula [5]. [Chemical 2] [In the formula, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic residue, and R _{1 to} R ₆ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group,
It represents an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue. ] 3. Pyrene-1,2,6,7 represented by the general formula [6]
-Reacting a tetracarboxylic dianhydride derivative with a diamino compound represented by the general formula [7],
The method for producing the pyrene compound according to claim 1. [Chemical 3] [In the general formula [6], R _{1 to} R ₆ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue.
Further, in the general formula [7], X represents a substituted or unsubstituted divalent aromatic ring. ] 4. Pyrene-1,2,6,7 represented by the general formula [6]
-The method for producing a pyrene-based compound according to claim 2, wherein the tetracarboxylic dianhydride derivative is reacted with an amino compound represented by the general formula [8]. [Chemical 4] [In the general formula [6], R _{1 to} R ₆ represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, an aralkyl group, or a substituted or unsubstituted aromatic ring residue.
In the general formula [8], R represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic ring residue. ] 5. An electrophotographic photoreceptor having a photosensitive layer on a conductive support or a conductive layer, wherein the photosensitive layer contains the pyrene-based compound according to claim 1. 6. An electrophotographic photosensitive member having a photosensitive layer on a conductive support or a conductive layer, wherein the photosensitive layer contains the pyrene compound according to claim 2.