JP3404923B2 - Electrophotographic photoreceptor - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor. More specifically, the present invention relates to a highly sensitive electrophotographic photoreceptor containing a novel bisazo compound.

[0002]

2. Description of the Related Art As a photoconductor for electrophotography, a photoconductor using an inorganic photoconductive substance such as selenium, cadmium sulfide and zinc oxide has been used in the past, but recently, it is non-polluting. An organic photoconductive compound (hereinafter referred to as “photoconductive compound”) having many advantages such as easy production and handling, good image quality, and easy production of photoconductors of various shapes such as drums, sheets and belts. So-called OPC photoconductors using OPC (abbreviated as OPC) have come to be used for plain paper copying machines and printers, and the proportion thereof is increasing year by year.

[0003]

OPC photoconductors have many advantages over conventional inorganic photoconductors, but they are inferior in sensitivity and durability, and currently they are mainly low speed. Used in the machine field. Therefore, development of OPC having excellent sensitivity and durability is desired.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have developed a novel OP for obtaining a highly sensitive and durable electrophotographic photoreceptor.
As a result of diligent studies on C, the present invention has been found out that a specific bisazo compound is suitable. That is, the gist of the present invention is to provide the following general formula [I] on a conductive support.

[0005]

[Chemical 2]

Wherein R 1 is substituted with an aryl group
Represents a chain hydrocarbon group containing a double bond or a triple bond , and K1 and K2 represent a coupler residue containing a hydroxyl group having a coupling ability. And a photosensitive layer containing a bisazo compound represented by the formula (1).

The present invention will be described in detail below. The bisazo compound contained in the electrophotographic photoreceptor of the present invention has a structure represented by the above general formula [I]. In the general formula [I], R ¹ is, for example, a carbon chain having a double bond such as a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group and a 2-methylallyl group. Hydrogen group; chain hydrocarbon groups having a triple bond such as ethynyl group, 2-propynyl group, and 2-butynyl group. These groups may further have a substituent, and examples of the substituent include aryl groups such as phenyl group and naphthyl group; substituted aryl groups such as tolyl group; methoxy group, ethoxy group, propoxy group, butoxy group. An alkoxy group such as;
Hydroxyl group; nitro group; cyano group; amino group; substituted amino group such as dimethylamino group, diethylamino group, dibenzylamino group; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; carboxyl group; ethoxycarbonyl And alkoxycarbonyl groups such as groups; carbamoyl groups; aryloxy groups such as phenoxy groups; arylalkoxy groups such as benzyloxy groups; aryloxycarbonyl groups such as phenyloxycarbonyl groups. Of these, an aryl group is preferable. Examples of the chain hydrocarbon group containing a substituted unsaturated bond include a styryl group, a cinnamyl group and a 3-phenyl-2-propynyl group. R ¹ is particularly preferably an allyl group, 2-butenyl group, 2-propynyl group, 2-butynyl group, cinnamyl group or 3-phenyl-2-propynyl group. K ¹ and K ² represent a coupler residue containing a hydroxyl group having a coupling ability, and at least one of K ¹ and K ² is [II-a] or [II-
b], [III-a], or [III-b] is preferable.

[0008]

[Chemical 3]

(In the formula, A represents a heterocyclic divalent group containing a nitrogen atom in the ring, or an aromatic hydrocarbon divalent group, which may have a substituent) Formula [II -A], [II-b], [III-a], [III-
b], A is a divalent group of an aromatic hydrocarbon, or
A heterocyclic divalent group containing a nitrogen atom in the ring is shown. Examples of the divalent group of an aromatic hydrocarbon include a divalent group of a monocyclic aromatic hydrocarbon such as an o-phenylene group; an o-naphthylene group,
Peri-naphthylene group, 1,2-anthraquinonylene group, 9,10-phenanthrylene group and other condensed polycyclic aromatic hydrocarbon divalent groups and the like can be mentioned.

The heterocyclic divalent group containing a nitrogen atom in the ring includes, for example, 3,4-pyrazolediyl group,
5,3-pyridinediyl, 5,5-hyrimidinediyl group, 6,7-indazolediyl group, 5,6-benzimidazolediyl group, 6,7-quinolinediyl group and the like 5
Examples thereof include a 10-membered heterocycle, and preferably a heterocyclic divalent group containing 2 or less nitrogen atoms in the ring.

In consideration of sensitivity and durability, o-phenylene group, o-naphthylene group, peri-naphthylene group, 2,3-pyridinediyl group, 4,5-pyrimidinediyl group, especially o-phenylene group, The o-naphthylene group is preferred. In the present invention, 2 of these aromatic hydrocarbons
The divalent group and the divalent group of the heterocycle containing a nitrogen atom in the ring may have a substituent. Examples of such a substituent include an alkyl group such as a methyl group, an ethyl group, an n-propyl group, a 1-propyl group, an n-butyl group, an i-butyl group and an n-hexyl group; a methoxyl group, an ethoxyl group and a propoxy group. Alkoxyl group such as benzyl group, butoxyl group; hydroxyl group; nitro group; cyano group; amino group; substituted amino group such as dimethylamino group, diethylamino group, dibenzylamino group; halogen atom such as fluorine atom, chlorine atom; carboxyl Group; alkoxycarbonyl group such as ethoxycarbonyl group; carbamoyl group; aryloxy group such as phenoxy group; arylalkoxy group such as benzyloxy group;
Examples thereof include aryloxycarbonyl groups such as phenyloxycarbonyl group. Among them, alkyl group, alkoxyl group, nitro group, halogen atom, hydroxyl group, carboxyl group, especially, methyl group, methoxyl group, nitro group,
Chlorine atom and hydroxyl group are preferred. As the other coupler, residues of the couplers represented by the following general formulas (IV-a) to (IV-i) are particularly preferable.

[0012]

[Chemical 4]

(In the above formula, Y ₁ and Y ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group, a heterocyclic group, an alkoxy group or an aryloxy group. Group, aralkyloxy group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted hydrazinocarbonyl group, acyl group or acylamino group.)

[0014]

[Chemical 5]

(In the above formula, Y ₃ is a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an aralkyloxy group or a carboxyl group. Represents a group, an alkoxycarbonyl group, an aryloxycarbonyl group or an acyl group, and P represents a divalent group required for being condensed with a benzene ring to form an aromatic hydrocarbon ring or a heterocycle.)

[0016]

[Chemical 6]

(In the above formula, R ₂ and R ₃ each independently represent a hydrogen atom, a lower alkyl group which may have a substituent, an aryl group or a heterocyclic group, and R ₂ and R ₃
May combine with each other to form a ring. P is the same as in the general formula (IV-b). )

[0018]

[Chemical 7]

(In the above formula, R ₂ , R ₃ and P are the same as those in the above general formula (IV-c).)

[0020]

[Chemical 8]

(In the above formula, R ₄ and R ₅ are each independently a hydrogen atom, an alkyl group which may have a substituent, an unsaturated alkyl group which may have a substituent, or an aryl group. Group, a heterocyclic group, a vinyl group which may have a substituent, or a butadienyl group which may have a substituent,
And R ₄ and R ₅ may combine with each other to form a ring. P is the same as in the general formula (IV-b). )

[0022]

[Chemical 9]

(In the above formula, R ₂ and R ₄ are the same as in the above general formula (IV-c) and general formula (IV-e).)

[0024]

[Chemical 10]

(In the above formula, R ₂ and P are the same as in the above general formulas (IV-c) and (IV-b).)

[0026]

[Chemical 11]

(In the above formula, R ₆ represents an alkyl group which may have a substituent or an unsaturated alkyl group, or an aryl group.) Next, these general formulas (IV-a) to Some specific examples of the substituent in (IV-i) are shown below: Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group which may have a substituent include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-hexyl group, an n-octyl group and a benzyl group. , P-methylbenzyl group, p-chlorobenzyl group, 2-phenylethyl group, 1
-Naphthylmethyl group, 2-naphthylmethyl group, allyl group, 2-hydroxyethyl group, 2-methoxyethyl group,
Examples thereof include a 3-morpholinopropyl group, a 2-diethylaminoethyl group, a 3-carbazolylmethyl group, and among these, the lower alkyl group usually indicates an alkyl group having 1 to 6 carbon atoms.

As the aryl group, a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthryl group,
Aromatic hydrocarbon groups such as anthraquinolyl group, acenaphthyl group, fluorenyl group, biphenylyl group, p-terphenylyl group, p-styrylphenyl group, and the like,
Examples of these substituents include alkyl groups such as methyl group, ethyl group and butyl group; halogen atoms such as fluorine, chlorine, bromine and iodine; alkoxy groups such as methoxy group, ethoxy group and butoxy group; aryloxy groups such as phenoxy group. Group; hydroxy group; nitro group; cyano group; amino group; substituted amino group such as dimethylamino group, diethylamino group, dibenzylamino group; carboxyl group; alkoxycarbonyl group such as ethoxycarbonyl group; aryl such as phenyloxycarbonyl group Roxycarbonyl group; Acyloxy group such as acetoxy group and benzoyloxy group; Acyl group such as acetyl group and benzoyl group; Substituted aminocarbonyl group such as carbamoyl group, dimethylaminocarbonyl group and phenylaminocarbonyl group; benzyloxy group and phenethyloxy group Aryl group Kokishi group, and the like.

Examples of the heterocyclic group are furyl group, thienyl group, thiazolyl group, indolyl group, pyrrolyl group, carbazolyl group, pyridyl group, quinolyl group, imidazolyl group,
Oxazolyl group, triazolyl group, piperidyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, acridyl group, xanthenyl group, phenazinyl group, phenothiazinyl group, coumarinyl group, etc., and the same substituents as aryl group You may have.

Examples of the alkoxy group include a methoxy group and an ethoxy group, and examples of the aryloxy group include a phenoxy group, a p-chlorophenoxy group, a p-methylphenoxy group, a 1-naphthoxy group, and an aralkyloxy group. Examples thereof include a benzyloxy group and a phenethyloxy group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group, and examples of the aryloxycarbonyl group include a phenoxycarbonyl group and a 1-naphthoxycarbonyl group.

Examples of P include a divalent group required to be condensed with a benzene ring to form an aromatic hydrocarbon or a heterocyclic ring such as a naphthalene ring, anthracene ring, carbazole ring, benzocarbazole ring and dibenzofuran ring. R ₂
Examples of the group of R ₃ and R ₃ which are bonded to each other to form a ring include a cyclohexylidene group, an indenylidene group, a fluorenylidene group, a pentamethylene group, and the like. Examples of unsaturated alkyl groups include allyl group, 3-butenyl group, cinnamyl group and the like. The bisazo compound of the present invention has, for example, the following general formula [V]

[0032]

[Chemical 12]

(In the formula, R ¹ has the same meaning as in the above-mentioned general formula [I].) The diamine can be easily synthesized by tetrazation by a conventional method and coupling with a corresponding coupler. Coupler residue K
^{When 1} and K ² are different from each other, ^two corresponding couplers may be mixed and used.

The coupling reaction may be carried out according to a known method, usually in water and / or an organic solvent such as dimethylformamide and dimethylsulfoxide at a reaction temperature of 30 ° C. or lower for about 1 to 10 hours. Next, the aromatic diamine represented by the general formula [V] is specifically produced, for example, according to the following method, but the present invention is not limited thereto. The aromatic diamine represented by the general formula [V] can be easily produced by a known method such as the following reaction formula.

[0035]

[Chemical 13]

(In the above reaction formula, R ¹ is the above general formula [I]
And X represents a halogen atom such as a bromine atom, a chlorine atom and an iodine atom, or a leaving group such as a p-toluenesulfonyloxy group and a methanesulfonyloxy group. ) Explaining the above reaction formula in detail, for example, 9 (10H)
Acridone (compound [VI]) and compound [VII] in a reaction-inert organic solvent such as toluene, xylene, dimethylformamide or tetrahydrofuran, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate,
The compound [VIII] is obtained by reacting with a base such as sodium hydride to react. Then, the dinitro compound [IX] is obtained by using fuming nitric acid in a solvent such as acetic acid or sulfuric acid. Then, the compound [V] can be produced in good yield by reduction under a known combination condition of iron powder, zinc, tin chloride or the like and hydrochloric acid, acetic acid or the like. Typical examples of the electrophotographic photoreceptor of the present invention include bisazo compounds as shown in Table 1 below.

[0037]

[Table 1]

[0038]

[Table 2]

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

[0042]

[Table 6]

[0043]

[Table 7]

The electrophotographic photoreceptor of the present invention has a photosensitive layer containing one or more bisazo compounds represented by the general formula [I]. Various types of photosensitive layers are well known, but any type thereof may be used in the photoreceptor of the present invention. Particularly preferred is a laminated photoreceptor in which a bisazo compound of the present invention is dispersed as a charge generating substance in a binder, and this is used as a charge generating layer, and a charge transporting layer containing a well-known charge transporting substance is laminated, or the above bisazo compound. A single-layer type photoconductor in which a well-known charge transport material is added to the compound dispersion layer may be used.

The bisazo compound represented by the general formula (I) of the present invention has a high charge carrier generation efficiency and a high carrier injection efficiency into the charge carrier transport medium, and has the above-mentioned laminated type or single layer type function-separated photoreceptor. It has excellent performance as a charge generating substance. The charge transport material used in combination with the bisazo compound of the present invention is generally classified into two types, an electron transport medium and a hole transport medium, and both can be used in the photoconductor of the present invention, or a mixture thereof can be used. Can also be used. As an electron transport medium, an electron-withdrawing compound having an electron-withdrawing group such as a nitro group, a cyano group, an ester group, for example, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, etc. Examples include nitrated fluorenone and tetracyanodimethane. Further, as a hole transport medium, an electron-donating organic photoconductive compound, for example, a heterocyclic compound such as carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, thiadiazole; triphenylmethane, etc. Reel alkane derivative (for example, JP-A-60-8733)
4); Triarylamine derivatives such as triphenylamine (for example, JP-A-56-4148, 58-20344)
6); phenylenediamine derivatives (for example, JP-A-54-54)
110836); N-phenylcarbazole derivative (Japanese Patent Publication No. 63-18738); Stilbene derivative (for example, JP-A-58-65440, 58-198043, 58-1).
98425); hydrazone compounds (see, for example, JP-A-57-57).
11350, 57-67940, 58-108359,
54-150128, 58-159536) and the like, and particularly, a substituted amino group such as a dialkylamino group and a diphenylamino group, an electron-donating group such as an alkoxy group and an alkyl group, or an electron-donating group thereof. A compound having a large electron-donating property in which an aromatic ring group substituted with is substituted. Further, polymers such as polyvinylcarbazole having a group composed of these compounds in the main chain or side chain can also be mentioned.

The electrophotographic photoreceptor of the present invention can be produced by a conventional method. That is, the electrophotographic photoreceptor of the present invention,
On a conductive support, a laminated type having a charge generation layer containing the bisazo compound of the present invention and a charge transport layer, or a single layer type photosensitive body having a photosensitive layer in which the bisazo compound is dispersed,
In addition to these, an intermediate layer such as an adhesive layer or a blocking layer, a protective layer, or a layer for improving performance such as electrical characteristics or mechanical characteristics may be provided.

As the conductive support, any of those known in electrophotographic photoreceptors can be used. Specific examples thereof include metal drums of aluminum, copper, nickel or the like, seat belts, laminates of these metal foils, and vapor-deposited products. Further, there may be mentioned plastic films, plastic drums, papers, etc. which have been subjected to a conductive treatment by coating a conductive substance such as metal powder, carbon black, copper iodide, or a polymer electrolyte with a suitable binder.
Further, a conductive plastic sheet or drum containing a conductive substance such as metal powder, carbon black or carbon fiber, or a plastic film having a conductive metal oxide layer such as tin oxide or indium oxide on its surface. And so on.

In the above-mentioned laminated type photoreceptor, a charge generating layer is usually formed on a conductive support, and a charge transporting layer is formed on the charge generating layer, but the reverse construction is also possible. The charge generation layer is formed by applying a coating solution containing the bisazo compound of the present invention and a binder polymer and drying. The bisazo compound may be dissolved, but it is usually applied as a dispersed coating liquid. Butylamine as a solvent for coating liquid preparation,
Basic solvents such as ethylenediamine; ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; N, N-dimethylformamide, acetonitrile, N-methylpyrrolidone Aprotic polar solvents such as dimethyl sulfoxide; alcohols such as methanol, ethanol and isopropanol;
Esters such as ethyl acetate, methyl formate and methyl cellosolve acetate; chlorinated hydrocarbons such as dichloroethane and chloroform.

When the bisazo compound is dispersed, 1 μm
It is necessary to make the particle diameter m or less, preferably 0.5 μm or less. As the binder, styrene, vinyl acetate, acrylic acid ester, methacrylic acid ester, vinyl alcohol, polymers and copolymers of vinyl compounds such as ethyl vinyl ether, phenoxy resin, polysulfone, polyvinyl acetal, polycarbonate, polyester, polyamide, polyurethane, Examples thereof include cellulose ester, cellulose ether, epoxy resin, silicon resin and the like.

The ratio of the bisazo compound of the present invention to the binder polymer is not particularly limited, but generally 5 to 500 parts by weight, preferably 20 to 300 parts by weight of the binder polymer is used per 100 parts by weight of the bisazo compound. To do. In addition to the above, a dispersion stabilizer, a coatability improving agent, and a dye, an electron-withdrawing compound and other additives for improving the performance may be added to the above coating liquid. The thickness of the charge generation layer is 0.05 to 5 μm, preferably 0.1 to 2 μm.

One or more of the above charge transport substances are dissolved in the above coating liquid for the charge generation layer, and the film thickness after drying is 5 to 5
A single-layer type photoreceptor can be obtained by coating on a conductive support so as to have a thickness of 0 μm, preferably 10 to 30 μm. The ratio of the bisazo compound to the binder polymer and the charge transporting substance is usually 10 to 1000 parts by weight, preferably 30 to 10 parts by weight of the binder polymer with respect to 10 parts by weight of the bisazo compound.
500 parts by weight, the charge transport material is 5 to 1000 parts by weight, preferably 20 to 500 parts by weight.

In the multi-layer type photoreceptor, a charge transport layer is formed by applying a coating solution containing a charge transport substance onto the charge generating layer and drying it. When the charge transport material is a polymer compound having film-forming properties, the binder polymer may not be used, but it may be mixed for the purpose of improving flexibility. In the case of a low molecular weight compound, a binder polymer is used for forming a film. As the binder polymer, those mentioned above are used, and the amount thereof is usually in the range of 30 to 300 parts by weight, preferably 40 to 200 parts by weight, based on 100 parts by weight of the charge carrier transport medium. The thickness of the charge transport layer is 5 to 70 μm, preferably 10 to 50
It is formed in the range of μm.

In addition to the above, various additives can be used in the charge transport layer in order to improve the performance and improve the mechanical strength and durability of the coating film. Examples of such additives include electron-withdrawing compounds and dyes, stabilizers such as ultraviolet absorbers and antioxidants, coatability improving agents, plasticizers, cross-linking agents and the like.
Examples of the electron-withdrawing compound include chloranil and 2,3-
Dichloro-1,4-naphthoquinone, 2-methylanthraquinone, 1-nitroanthraquinone, 1-chloro-5-
Quinones such as nitroanthraquinone, 2-chloroanthraquinone and phenanthrenequinone; aldehydes such as 4-nitrobenzaldehyde; 9-benzoylanthracene, indandione, 3,5-dinitrobenzophenone, 3,3 ', 5,5'-tetra Ketones such as nitrobenzophenone; acid anhydrides such as phthalic anhydride and 4-chloronaphthalic anhydride; tetracyanoethylene, terephthalalmalononitrile, 4-nitrobenzalmalononitrile, 4-benzoyloxybenzalmalononitrile, 4
Cyano compounds such as-(p-nitrobenzoyloxy) benzalmalononitrile; 3-benzalphthalide, 3-
(Α-Cyano-p-nitrobenzal) phthalide, 3-
(Α-Cyano-p-nitrobenzal) -4,5,6,7
Phthalides such as tetrachlorophthalide.

[0054]

EXAMPLES The present invention will be described in more detail with reference to Examples and Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. In the Reference Examples and Examples, [parts] means [parts by weight].

Reference Example 1 12.50 g of 9 (10H) acridone was suspended in 125 ml of N, N-dimethylformamide, and 10.24 g of sodium hydroxide was added at room temperature. After stirring at room temperature for 1 hour, 15.49 g of allyl bromide was added dropwise and the mixture was stirred at 60 ° C. for 1 hour. The reaction solution was poured into water, neutralized with 2N hydrochloric acid, and the precipitated crystals were collected by filtration. This was reprecipitated with ethanol-water and dried to obtain 13.84 g of the target substance, N-allyl-acridone, as yellowish white crystals.

13.84 g of the above N-allyl-acridone
Was dissolved in 44 ml of concentrated sulfuric acid under ice cooling. below freezing,
Slowly add 8.23 g of fuming nitric acid at a temperature of 10 ° C or lower to 30
After stirring for 1 minute, the mixture was stirred at room temperature for 1.5 hours. The reaction solution was poured into ice water, and the precipitated yellow crystals were collected by filtration and washed with water several times. This was suspended in water, neutralized with sodium hydrogen carbonate, collected by filtration and washed with methanol and ethyl acetate. This was recrystallized from dimethylformamide (hereinafter abbreviated as "DMF") and dried to obtain 12.04 g of N-allyl-2,7-dinitroacridone, which was a target substance, as yellow crystals.
This N-allyl-2,7-dinitroacridone Mas
The s analysis values were as follows. Mass: 325 (M ⁺ ), 295, 279, 233,
204, 190, 164, 138, 102, 75, 3
9,30

37.19 g of iron powder and 37 ml of a 2: 1 solution of DMF-water were vigorously stirred at 90 ° C., and a mixed solution of 7.44 g of 35% concentrated hydrochloric acid and 19 ml of DMF-water (2: 1) was added thereto. The mixture was added dropwise, heated to 100 ° C., and stirred for 10 minutes.
Next, the temperature is lowered to 85 ° C., and the N-allyl-
2,7-Dinitroacridone 12.04 g DMF48
The ml solution was added dropwise, and the mixture was stirred at 80 to 90 ° C for 20 minutes. 7.44 g of sodium hydrogen carbonate was added, the mixture was filtered while hot, and the filtrate was poured into water and stirred under ice cooling to precipitate orange crystals. This is collected by filtration, and an alumina column (50
g, ethyl acetate / methanol = 9/1), further washed with ethyl acetate by suspension, and dried to obtain 3.08 g of N-allyl-2,7-diaminoacridone as a target substance as reddish brown crystals. It was identified as N-allyl-2,7-diaminoacridone by mass spectrum and infrared absorption spectrum measurement (FIG. 1). This N-allyl-2,7
-The mass analysis result of diaminoacridone was as follows.

Mass: 265 (M ⁺ ), 250, 22
4,196,169,132,63,39,28 N-allyl-2,7-diaminoacridone 3.08
g, 50 ml of demineralized water, and 8.5 ml of 35% concentrated hydrochloric acid were charged, and the mixture was stirred at room temperature for 15 minutes, then, about 10 g of ice was added, and 0 to
The temperature was lowered to 5 ° C. A solution prepared by dissolving 1.76 g of sodium nitrite in 14 ml of demineralized water was slowly added dropwise at 5 ° C or lower,
Stir for 2 hours. This is filtered to remove insoluble matter, and the filtrate is kept cool at 5 ° C. or lower and 42% borofluoric acid 9.70 g.
Was added dropwise and stirred for 30 minutes. The precipitated crystals are collected by filtration,
After sequentially washing with cold water and methanol, it was dried at room temperature to obtain 4.67 g of a target substance, tetrazonium borofluoride of N-allyl-2,7-diaminoacridone, as yellow crystals.

A mixed solvent of 30 parts of acetic acid and 150 parts of nitrobenzene with 13.8 parts of 3-hydroxynaphthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 9.2 parts of o-phenylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.). The mixture was dissolved and stirred in, and the reaction was carried out at the boiling point of acetic acid for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitated crystals were collected by filtration, washed well with methanol, and dried. The obtained crystals were in the form of yellow fluff and did not melt at 320 ° C or lower. From elemental analysis and infrared absorption spectrum measurement, this crystal was found to be 2-hydroxy and 5-hydroxy-7H-benzimidazo [2,1-a] benz [de] isoquinolin-7-one. The yield was 17.8 parts, and the elemental analysis values were as follows.

Calculated as C ₁₈ H ₁₀ O ₂ N ₂ : C75.54%, H3.53%, N9.78% Actual value: C75.50%, H3.49%, N9.72% The above-mentioned 2-hydroxy Alternatively, 1.24 g of 5-hydroxy-7H-benzimidazo [2,1-a] benzo [de] isoquinolin-7-one was added to 186 m of dimethyl sulfoxide.
It was dissolved in 1 by heating and left to cool to room temperature. Into this solution, 12 ml of a solution of N-allyl-2,7-diaminoacridone tetrazonium borohydrofluoride 0.93 g in dimethyl sulfoxide was added dropwise. Then, the coupling reaction was started by dropping a solution of 1.80 g of sodium acetate dissolved in 5 ml of water into the reaction system. After completion of dropping, the mixture was continuously stirred for 3 hours and collected by filtration. Next, the obtained bisazo compound was washed successively with a 10% aqueous acetic acid solution, water and tetrahydrofuran, and then dried. The obtained solid has a deep yellow-green color and the yield is 1.38 g.
However, it did not melt below 320 ° C. From the infrared absorption spectrum measurement, this was identified as a mixture of the following three kinds of bisazo compounds as the target substance.

Embedded image R = —CH ₂ CH═CH ₂

[0061]

[Chemical 15]

In the following Reference Examples and Examples, the coupler residue is represented by the general formula [II-a], [II-b] or [II-
When the groups I-a] and [III-b] are introduced, the same 3
The isomers of the species are obtained, one of which will be described as a representative. The bisazo compounds of the present invention used in the following examples were synthesized by this reference example or a method similar thereto.

Examples 1 to 33 0.4 parts of each of the bisazo compounds shown in Table 1 having a structure corresponding to the general formula [I], 4-methoxy-
It was dispersed together with 30 parts of 4-methylpentanone-2 by a sand grinder, and 0.4 parts of polyvinyl butyral (trade name S-REC, manufactured by Sekisui Chemical Co., Ltd.) was added and dissolved therein. The dispersion liquid of the obtained azo compound was made to a thickness of 7
A dry film thickness of 0.4 g / m ² with a wire bar on the aluminum vapor-deposited layer vapor-deposited on a 5 μm polyester film.
And then dried. A solution prepared by dissolving 90 parts of pyrene-2-carbaldehyde diphenylhydrazone and 100 parts of a polycarbonate resin (trade name Novarex 7025, manufactured by Mitsubishi Kasei Co., Ltd.) in 670 parts of dioxane was dried on the charge generation layer thus obtained. 28 μm film thickness
To form a charge transport layer. In this way, an electrophotographic photosensitive member having a photosensitive layer composed of two layers was obtained.

Table 2 shows the values of the half-exposure amount (E1 / 2) as the sensitivity of these photoconductors. The bisazo compound numbers in Table 2 are the numbers in Table 1 above. The half-exposure amount in Table 2 was measured for the photoconductor using an electrostatic copying paper test device (Kawaguchi Denki Seisakusho model SP-428). First, it was charged by a corona discharge at -6.5 kV in a dark place, and then exposed to white light with an illuminance of 5 lux to determine the exposure amount required for the surface potential to be attenuated to half the initial surface potential.

[0065]

[Table 8]

[0066]

The electrophotographic photoreceptor containing the bisazo compound of the present invention has high sensitivity and good color sensitivity.
It is more sensitive than compounds in which the same type of coupler residue is bound. Not only electrophotographic plain paper copiers,
The photoconductor is also suitable as a photoconductor for printers such as a laser printer, a liquid crystal, a shutter printer, and an LED printer, which are particularly required to have stable performance and reliability.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum diagram of a diamine compound obtained in Reference Example 1.

Continuation of front page (56) Reference JP-A 64-29848 (JP, A) JP-A 64-11264 (JP, A) JP-A 63-49765 (JP, A) JP-A 58-4151 (JP , A) JP-A-2-54273 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 5/06 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. On a conductive support, the following general formula [I]: (In the general formula [I], R 1 may be substituted with an aryl group.
It represents a chain hydrocarbon group containing a good double bond or triple bond , and K1 and K2 represent a coupler residue containing a hydroxyl group having a coupling ability. ) An electrophotographic photoreceptor having a photosensitive layer containing a bisazo compound represented by 2. The photosensitive layer contains a charge generating substance and a charge transporting substance, and the bisazo compound represented by the general formula (I) according to claim 1 is used as the charge generating substance. The electrophotographic photoreceptor according to 1. Wherein the photosensitive layer is at least comprises a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance and a binder resin, according to claim 1, wherein the charge generating material in the charge generation layer 3. The electrophotographic photoreceptor according to claim 1, wherein the bisazo compound represented by the general formula (I) is used. 4. The electrophotographic photoreceptor according to claim 3, wherein the charge generation layer contains a charge generation substance and a binder resin.