JP2006257071A - Bishydrazone compound having triarylamine skeleton and electrophotographic photoreceptor and apparatus for forming image using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having excellent high sensitivity and a high speed of response. <P>SOLUTION: A bishydrazone compound is represented by general formula [1] (wherein, A<SB>1</SB>to A<SB>6</SB>represent each an aryl group; and B<SB>1</SB>to B<SB>4</SB>represent each an arylene group). The electrophotographic photoreceptor and an apparatus for forming an image are obtained by using the compound. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a bishydrazone compound having a special effect as a charge transport material contained in a photosensitive layer of an electrophotographic photosensitive member and having a triarylamine skeleton, and an electrophotographic photosensitive member and an image forming apparatus using the same.

Since the electrophotographic photosensitive member is repeatedly used in an electrophotographic process, that is, a cycle of charging, exposure, development, transfer, cleaning, static elimination, and the like, it is deteriorated by various stresses during that time. Among these, as the chemical degradation, for example plain strongly oxidizing ozone or NO _X generated from the corona charger used can be mentioned that the damage to the photosensitive layer as a charger, if used repeatedly, chargeable Deterioration in electrical stability such as a decrease in the residual potential and an increase in the residual potential, and an image defect associated therewith may occur. These are largely derived from chemical deterioration of charge transport materials contained in the photosensitive layer in a large amount.

  In addition, with the recent increase in the speed of electrophotographic processes, higher sensitivity and faster response are essential. Among these, in order to achieve high sensitivity, it is necessary not only to optimize the charge generation material, but also to develop a charge transport material with good matching with the charge generation material. It is necessary to develop a charge transport material that exhibits a sufficiently low residual potential at the time of exposure.

  Many charge transport compounds and electron transport compounds are known in the art related to electrophotography. Non-limiting examples of charge transport compounds include, for example, pyrazoline derivatives, fluorene derivatives, oxadiazole derivatives, stilbene derivatives, enamine derivatives, enamine stilbene derivatives, hydrazone derivatives, carbazole hydrazone derivatives, tria Arylamines such as reelamines (N, N-disubstituted), polyvinylcarbazole, polyvinylpyrene, polyacenaphthylene or multiplexed hydrazone compounds (such as at least two hydrazone groups and triphenylamine) (N, N-disubstituted) arylamines and carbazole, julolidine, phenothiazine, phenazine, phenoxazine, phenoxathiin, thiazole, oxazole, isoxazole, dibenzo (1,4) dioxin, thianthre , Imidazole, benzothiazole, benzotriazole, benzoxazole, benzimidazole, quinoline, isoquinoline, quinoxaline, indole, indazole, pyrrole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazole, oxadiazole, tetrazole, thiadiazole, benziso And at least two substituents selected from the group consisting of heterocycles such as xazole, benzisothiazole, dibenzofuran, dibenzothiophene, thiophene, thianaphthene, quinazoline or cinolin). Thus, many charge transport materials can be used, but the presence of other charge transport materials is necessary to meet the diverse requirements of the particular electrophotographic art.

Among these, hydrazone compounds are often used as charge transport materials in recent years from the viewpoint of excellent electrical characteristics. In particular, a photoconductor using a hydrazone compound having a triphenylamine skeleton described in Patent Documents 1 to 3 has a relatively fast mobility, and recently, an electrophotographic copying machine, a printer or the like has been accelerated. Miniaturization is realized. However, an electrophotographic photoreceptor using a conventional hydrazone compound as a charge transfer material is still insufficient in terms of electric characteristics of residual potential and sensitivity, which are essential performances as an electrophotographic photoreceptor. Therefore, the reality is that the photoreceptor market is not satisfied.
JP-A-3-138654 Japanese Patent No. 2572650 Japanese Patent No. 2917473

  In view of the present situation, the present invention overcomes the conventional drawbacks and provides an electrophotographic photoreceptor excellent in high sensitivity and high speed response.

  As a result of intensive studies on the charge transport material, the present inventors have found that the bishydrazone compound having a triarylamine skeleton according to the present invention is a charge transport material that can solve the above problems, and completed the present invention. It came to do. That is, the gist of the present invention is a bishydrazone compound having a triarylamine skeleton represented by the following general formula [1]:

(In the general formula [1], A _{1 to} A ₆ each represents an aryl group which may have a substituent. B _{1 to} B ₄ each represents an arylene group which may have a substituent. Provided that (1) one of B _{1 to} B ₄ has a substituent; (2) _one of A ₁ and A ₂ has a substituent, and A _{3 to} A ₆ One of them has a substituent; (3) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ is an aryl group other than a phenyl group Satisfying at least one of the following conditions).

  Another gist of the present invention is an electrophotographic photosensitive member in which a photosensitive layer containing a charge generation material and a charge transport material is provided on a conductive support, and the charge transport material is represented by the following general formula [1]. An electrophotographic photosensitive member characterized by containing the bishydrazone compound represented.

(In the general formula [1], A _{1 to} A ₆ each represents an aryl group which may have a substituent. B _{1 to} B ₄ each represents an arylene group which may have a substituent. Provided that (1) one of B _{1 to} B ₄ has a substituent; (2) _one of A ₁ and A ₂ has a substituent, and A _{3 to} A ₆ One of them has a substituent; (3) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ is an aryl group other than a phenyl group Satisfying at least one of the following conditions.)

  Further, another gist of the present invention includes an electrophotographic photosensitive member, a charging unit that charges the electrophotographic photosensitive member, and an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image. An image forming apparatus comprising: a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member by exposure using toner, wherein the electrophotographic photosensitive member is an electron according to claim 1. An image forming apparatus characterized by being a photographic photosensitive member.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member having high sensitivity and low residual potential and excellent in high-speed response and an electrophotographic apparatus having the same.

  Hereinafter, the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the scope of the present invention.

  The bishydrazone compound having a triarylamine skeleton of the present invention is represented by the following general formula [1].

In the general formula [1], A ₁ and A ₂ may be the same or different and each represents an aryl group which may have a substituent. The aryl group is not particularly limited, but is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, and a pyrenyl group. Among them, a phenyl group and a naphthyl group are particularly preferable in terms of production cost. When a phenyl group and a naphthyl group are compared, a phenyl group is more preferable in terms of ease of synthesis in addition to manufacturing cost.

A _{4 to} A ₆ may be the same or different and each represents an aryl group which may have a substituent. The aryl group is not particularly limited, but is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, an anthranyl group, a phenanthryl group, and a pyrenyl group. Among these, a phenyl group and a naphthyl group are particularly preferable in terms of production cost and ease of synthesis.

In the general formula [1], B _{1 to} B ₄ may be the same or different and each represents an arylene group which may have a substituent. The arylene group is not particularly limited, but is preferably an arylene group having 6 to 20 carbon atoms, and examples thereof include a naphthylene group, an anthranylene group, a phenanthrylene group, and a pyrenylene group. Among these, a naphthylene group is particularly preferable from the viewpoint of production cost. Further, when a phenylene group and a naphthylene group are compared, a phenylene group is more preferable in terms of ease of synthesis in addition to manufacturing cost.

The substituent which A _{1 to} A ₆ and B _{1 to} B ₄ may have is not particularly limited, but an electron donating substituent having 1 to 10 carbon atoms is preferable, and has a hetero atom. May be. For example, a linear or branched alkyl group, alkenyl group, alkynyl group or the like having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkylamino having 2 to 4 carbon atoms Groups, aryl groups having 6 to 10 carbon atoms, and the like, specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, methoxy group Group, ethoxy group, propoxy group, N, N-dimethylamino group, N, N-diethylamino group, phenyl group, 4-tolyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-butylphenyl group, naphthyl Groups and the like. Among these, a linear or branched hydrocarbon group having 1 to 4 carbon atoms is particularly preferable from the viewpoint of electrical characteristics.

The bonding position of the substituent that A _{1 to} A ₆ may have is preferably a meta position or a para position, particularly preferably a para position, with respect to the directly bonded nitrogen atom. The bonding position of the substituent that B ₁ and B ₄ may have is preferably a meta position in view of the directly bonded nitrogen atom, and the bonding position of the substituent that B ₂ and B ₃ may have is a direct bond. The ortho position is preferable in view of the nitrogen atom. This is because it is easy to synthesize and has good electrical characteristics.

In the general formula [1], it is essential to satisfy at least one of the following conditions.
(1) one of B _{1 to} B ₄ has a substituent;
(2) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ has a substituent;
(3) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ is an aryl group other than a phenyl group;

A plurality of the above conditions (1) to (3) may be satisfied. When the condition (1) is satisfied, preferably at least one of A ₁ and A ₂ has a substituent, and more preferably (2) is satisfied. Further, when the condition (2) is satisfied, the condition (2) may be satisfied alone or other conditions may be satisfied, but the condition (1) is preferably satisfied. Further, when the condition (3) is satisfied, it may be alone or may satisfy other conditions, but preferably satisfies the condition (1).

  A hydrazone compound that does not satisfy any of the above conditions (1) to (3) has good initial charging voltage (V0) and potential drop (DDR) in electrical characteristics, but half exposure energy (E1 / 2) and residual The potential (Vr) does not show good results. The reason for this is not clear at present, but the constituent conditions of the present invention are estimated from the following.

When the N-B ₁ -B ₂ -N bond of the bishydrazone molecule is divided into the part I and the part II around the axis, first of all, when the part I has an electron-donating substituent, it strongly affects the electrical properties. It is thought to affect. This is considered to be because the portion I has a great influence on the charge transport.

Among them, 1) the arylene groups B _{1 to} B ₄ have an electron-donating substituent, 2) even if the above 1) is not satisfied, 1) at least part II has an electron-donating substituent, And an amine-terminal aryl group A _{3 to} A ₆ has an electron-donating substituent, 2) at least part II has an electron-donating substituent, and the amine-terminal aryl group A _{3 to} A ₆ is phenyl. In the case of an aryl group other than the group, an excellent effect is exerted on the electrical characteristics.

  Typical examples of the bishydrazone compound having a triarylamine skeleton represented by the general formula [1] include the following. However, it is not limited to these compounds.

  These bishydrazone compounds can be easily synthesized by known methods. For example, the exemplified compound CT-1 of the present invention can be produced according to the following reaction formula.

First, a diarylamine represented by α is oxidized with NaNO ₂ to synthesize a nitroso form represented by β. A diarylhydrazine represented by γ is obtained by reducing it with zinc. At the same time, the tetraphenylbenzidine derivative represented by δ is formylated by the Vilsmeier reaction to form a diformyl product represented by ε, to which diarylhydrazine γ is added, and heat condensation under acidic conditions is represented by Σ. A hydrazone compound is obtained.

  When producing CT-1, three isomers are formed. At this time, the production ratio of CT-1a is the highest. Similarly, when producing CT-2 and CT-3, three isomers are produced. At this time, the production ratio of CT-2a and CT-3a is the highest. The reason why such an isomer is produced is that when ε is synthesized from δ by formylation, a diformyl isomer is produced due to the effect of the substituent.

  In the electrophotographic technical field, charge generating compounds contained in an organic photoreceptor absorb light and form electron-hole pairs. Such electrons and holes are transported under a strong electric field over an appropriate time, and the surface charge that generates the electric field can be locally discharged. The discharge of the electric field in a specific area forms a surface charge pattern, which essentially corresponds to the pattern drawn by light. Such a charge pattern can be utilized to induce toner adhesion. The charge transport material according to the present embodiment is effective for charge transport, particularly for transporting holes from electron-hole pairs formed by charge generation compounds. In some embodiments, a specific charge transport material may be used with the bishydrazone compound having a triarylamine skeleton of this embodiment.

  Hereinafter, the configuration of the electrophotographic photoreceptor used in the present invention will be described. The structure of the electrophotographic photoreceptor of the present invention is not particularly limited as long as a photosensitive layer containing a bishydrazone compound produced by the above-described invention is provided on a conductive support (substrate). A function-separated type photoreceptor in which a generation layer and a charge transport layer are laminated is preferable.

<Conductive support>
There is no particular limitation on the conductive support, but for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel, and conductive powder such as metal, carbon, and tin oxide are added to impart conductivity. A resin material, a resin, glass, paper, or the like on which a conductive material such as aluminum, nickel, or ITO (indium tin oxide) is deposited or applied on the surface is mainly used. These may be used alone or in combination of two or more in any combination and ratio. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Further, a conductive material having an appropriate resistance value may be used on a conductive support made of a metal material in order to control conductivity and surface properties and to cover defects.

  Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method.

  The surface of the support may be smooth, or may be roughened by using a special cutting method or performing a polishing treatment. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without performing the cutting process.

<Underlayer>
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used.

  Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic material such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic material such as stearic acid, polyol, or silicon. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained.

  In addition, various particle sizes of the metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is usually 1 nm or more, preferably 10 nm or more, and usually 100 nm or less. Preferably it is 50 nm or less.

  The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, Polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitro Cellulose ester resins such as cellulose, cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate Compounds, organic zirconium compounds such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, a known binder resin such as a silane coupling agent and the like. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

  The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected, but is usually in the range of 10% by weight or more and 500% by weight or less from the viewpoint of dispersion stability and coatability. Is preferably used.

  The thickness of the undercoat layer can be selected arbitrarily, but is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and coatability. A known antioxidant or the like may be mixed in the undercoat layer. For the purpose of preventing image defects, pigment particles, resin particles and the like may be contained and used.

<Photosensitive layer>
As a type of the photosensitive layer, a charge generation material and a charge transport material are present in the same layer and are dispersed in a binder resin, a charge generation layer in which a charge generation material is dispersed in a binder resin, and a charge. A functional separation type (laminated type) composed of two layers of a charge transport layer in which a transport material is dispersed in a binder resin can be mentioned, but any type may be used.

  In addition, as the laminated photosensitive layer, a charge generation layer and a charge transport layer are laminated in this order from the conductive support side, and a charge transport layer and a charge generation layer are laminated in this order. There are reverse laminated type photosensitive layers, and any of them can be adopted, but a forward laminated type photosensitive layer capable of exhibiting the most balanced photoconductivity is preferable.

<Laminated photosensitive layer>
(Charge generation layer)
In the case of a laminated type photoreceptor (function separation type photoreceptor), the charge generation layer is formed by binding a charge generation material with a binder resin.

  Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments, but organic photoconductive materials are preferred, especially organic pigments. Is preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, a phthalocyanine pigment or an azo pigment is preferable, and a phthalocyanine pigment is more preferable. This is because the charge generating material exhibits high sensitivity and further matches well with the bishydrazone compound represented by the general formula [1].

  When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When a metal-free phthalocyanine compound or a metal-containing phthalocyanine compound is used as the charge generation material, a highly sensitive photoreceptor can be obtained with respect to a relatively long wavelength laser beam, for example, a laser beam having a wavelength around 780 nm. In the case of using an azo pigment such as diazo, trisazo, etc., for white light, laser light having a wavelength around 660 nm, or relatively short wavelength laser light, for example, laser having a wavelength around 450 nm or 400 nm A photoreceptor having sufficient sensitivity can be obtained.

  When an organic pigment is used as the charge generating material, a phthalocyanine pigment or an azo pigment is particularly preferable. The phthalocyanine pigment provides a photosensitive material with high sensitivity to a laser beam having a relatively long wavelength, and the azo pigment has a sufficient sensitivity to white light and a laser beam having a relatively short wavelength. , Each is excellent.

  When using a phthalocyanine pigment as a charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum or other metal or oxide thereof, halide, water Those having crystal forms of coordinated phthalocyanines such as oxides and alkoxides, and phthalocyanine dimers using oxygen atoms as bridging atoms are used. In particular, titanyl phthalocyanines (also known as oxytitanium) such as X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), and D-type (also known as Y-type), which are highly sensitive crystal types Phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, hydroxyindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and type I, type II, etc. The [mu] -oxo-aluminum phthalocyanine dimer is preferred.

  Among these phthalocyanines, A-type (also known as β-type), B-type (also known as α-type), and powder X-ray diffraction angle 2θ (± 0.2 °) are 27.1 ° or 27.3 °. D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type and 28.1 ° have the strongest peaks, and 26.2 ° have peaks Hydroxygallium phthalocyanine having a clear peak at 28.1 ° and a full width at half maximum W of 25.9 ° of 0.1 ° ≦ W ≦ 0.4 °, G-type μ-oxo -Gallium phthalocyanine dimer and the like are particularly preferable.

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state that can be put in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or they may be mixed in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, and crystallization. It may be the one that caused the condition. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

  When an azo pigment is used as the charge generation material, various bisazo pigments and trisazo pigments are preferably used. Examples of preferred azo pigments are shown below.

  When the organic pigments exemplified above are used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used. In this case, it is preferable to use a combination of two or more kinds of charge generating substances having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region, and among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are used in combination. It is more preferable.

  The binder resin used for the charge generation layer is not particularly limited, but examples include polyvinyl butyral resins, polyvinyl formal resins, polyvinyl acetal systems such as partially acetalized polyvinyl butyral resins in which a part of butyral is modified with formal, acetal, or the like. Resin, Polyarylate resin, Polycarbonate resin, Polyester resin, Modified ether type polyester resin, Phenoxy resin, Polyvinyl chloride resin, Polyvinylidene chloride resin, Polyvinyl acetate resin, Polystyrene resin, Acrylic resin, Methacrylic resin, Polyacrylamide resin, Polyamide Resin, polyvinyl pyridine resin, cellulosic resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, vinyl chloride -Vinyl acetate-vinyl acetate copolymers such as vinyl acetate copolymers, hydroxy-modified vinyl chloride-vinyl acetate copolymers, carboxyl-modified vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, etc. Insulating resins such as polymers, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, styrene-alkyd resins, silicon-alkyd resins, phenol-formaldehyde resins, poly-N-vinylcarbazole, polyvinyl anthracene, polyvinyl And organic photoconductive polymers such as perylene. Any one of these binder resins may be used alone, or two or more thereof may be mixed and used in any combination.

  Specifically, the charge generation layer is prepared by dispersing the halogen-substituted indium phthalocyanine of the present invention and other charge generation materials used in some cases in a solution obtained by dissolving the above-described binder resin in an organic solvent. Is applied on a conductive support (or an undercoat layer when an undercoat layer is provided).

  The solvent used for preparing the coating solution is not particularly limited as long as it dissolves the binder resin. For example, saturated aliphatic solvents such as pentane, hexane, octane, and nonane, and aromatics such as toluene, xylene, and anisole. Group solvents, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene, chloronaphthalene, amide solvents such as dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, isopropanol, n-butanol, benzyl alcohol, etc. Alcohol solvents, aliphatic polyhydric alcohols such as glycerin and polyethylene glycol, chain or cyclic ketone solvents such as acetone, cyclohexanone, methyl ethyl ketone, ester solvents such as methyl formate, ethyl acetate, n-butyl acetate, methylene chloride ,Black Halogenated hydrocarbon solvents such as form, 1,2-dichloroethane, chain or cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, acetonitrile, dimethyl Aprotic polar solvents such as sulfoxide, sulfolane, hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, triethylamine and other nitrogen-containing compounds, ligroin and other mineral oils, water, etc. Can be mentioned. Any one of these may be used alone, or two or more of these may be used in combination. In addition, when providing the above-mentioned undercoat layer, what does not melt | dissolve this undercoat layer is preferable.

  In the charge generation layer, the compounding ratio (weight) of the binder resin and the charge generation material is usually 10 parts by weight or more, preferably 30 parts by weight or more, and usually 1000 parts by weight with respect to 100 parts by weight of the binder resin. The film thickness is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less. If the ratio of the charge generation material is too high, the stability of the coating solution may be reduced due to aggregation of the charge generation material, while if the ratio of the charge generation material is too low, the sensitivity as a photoreceptor may be decreased. There is.

  As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. At this time, it is effective to refine the particles to a particle size in the range of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

(Charge transport layer)
The charge transport layer of the multilayer photoreceptor contains a charge transport material and usually contains a binder resin and other components used as necessary. Specifically, such a charge transport layer is prepared by, for example, preparing a coating solution by dissolving or dispersing a charge transport material and a binder resin in a solvent. In addition, in the case of a reverse lamination type photosensitive layer, it can be obtained by coating and drying on a conductive support (or on the undercoat layer when an undercoat layer is provided).

  As the charge transport material, the bishydrazone compound produced by the present invention described above is used. The bishydrazone compound of the present invention may be used alone or in combination of two or more in any ratio.

  In addition to the bishydrazone compound of the present invention, other known charge transport materials may be used in combination. When other charge transport materials are used in combination, the kind thereof is not particularly limited. For example, carbazole derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, butadiene derivatives and those in which a plurality of these derivatives are bonded are preferable. More specifically, compounds described in JP-A-2-230255, JP-A-63-225660, JP-A-58-198043, JP-B-58-32372, and JP-B-7-21646 Are preferably used. What combined multiple types of these compounds is preferable. Any one of these charge transport materials may be used alone, or two or more thereof may be used in any combination.

  The binder resin is used for securing the film strength. Examples of the binder resin for the charge transport layer include polymers and copolymers of vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylic ester resin, methacrylic ester resin, vinyl alcohol resin, and ethyl vinyl ether. Coalesced, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicon resin, silicon-alkyd resin, poly-N- A vinyl carbazole resin etc. are mentioned. Of these, polycarbonate resins and polyarylate resins are preferred. These binder resins can also be used after being crosslinked by heat, light or the like using an appropriate curing agent. Any one of these binder resins may be used alone, or two or more thereof may be used in any combination.

  The ratio of the binder resin to the charge transport material is 20 parts by weight or more of the charge transport material with respect to 100 parts by weight of the binder resin. Among these, 30 parts by weight or more is preferable from the viewpoint of residual potential reduction, and 40 parts by weight or more is more preferable from the viewpoint of stability and charge mobility when repeatedly used. On the other hand, from the viewpoint of thermal stability of the photosensitive layer, the charge transport material is usually used at a ratio of 150 parts by weight or less. Among these, 110 parts by weight or less is preferable from the viewpoint of compatibility between the charge transport material and the binder resin, 80 parts by weight or less is more preferable from the viewpoint of printing durability, and 70 parts by weight or less is most preferable from the viewpoint of scratch resistance.

  The thickness of the charge transport layer is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less, from the viewpoint of long life, image stability, and high resolution. Is in the range of 30 μm or less.

<Single layer type photosensitive layer>
The single-layer type photosensitive layer is formed using a binder resin in addition to the charge generation material and the charge transport material. Specifically, a charge generation material, a charge transport material, and various binder resins are dissolved or dispersed in a solvent to prepare a coating solution, and on a conductive support (or an undercoat layer when an undercoat layer is provided). It can be obtained by coating and drying.

  The types of the charge transport material and the binder resin and the use ratios thereof are the same as those described for the charge transport layer of the multilayer photoreceptor. The charge generating material is further dispersed in the charge transport medium comprising these charge transport material and binder resin.

  As the charge generation material, the same materials as those described for the charge generation layer of the multilayer photoreceptor can be used. However, in the case of a photosensitive layer of a single-layer type photoreceptor, it is necessary to sufficiently reduce the particle size of the charge generating material. Specifically, the range is usually 1 μm or less, preferably 0.5 μm or less.

  If the amount of the charge generating material dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity cannot be obtained, but if it is too large, there are adverse effects such as a decrease in chargeability and a decrease in sensitivity. It is usually used in the range of 0.5% by weight or more, preferably 1% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less based on the whole layer type photosensitive layer.

  Further, the use ratio of the binder resin and the charge generating material in the single-layer type photosensitive layer is such that the charge generating material is usually 0.1 parts by weight or more, preferably 1 part by weight or more, based on 100 parts by weight of the binder resin. It is 30 parts by weight or less, preferably 10 parts by weight or less. The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.

<Other functional layers>
For the purpose of improving film forming properties, flexibility, coating properties, contamination resistance, gas resistance, light resistance, etc., in both the photosensitive layer and the layers constituting the photosensitive layer, both of the multilayer type photosensitive member and the single layer type photosensitive member. Additives such as well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds, leveling agents, and visible light shielding agents may be included.

  Further, in both the laminated type photoreceptor and the single layer type photoreceptor, the photosensitive layer formed by the above procedure may be the uppermost layer, that is, the surface layer, but another layer may be provided on the photosensitive layer and used as the surface layer. Good. For example, a protective layer may be provided for the purpose of preventing wear of the photosensitive layer or preventing or reducing deterioration of the photosensitive layer due to discharge products generated from a charger or the like.

  The protective layer is formed by containing a conductive material in a suitable binder resin, or has a charge transporting ability such as a triphenylamine skeleton described in JP-A Nos. 9-190004 and 10-252377. A copolymer using a compound can be used.

  Examples of the conductive material used for the protective layer include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, and oxide. Metal oxides such as titanium, tin oxide-antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto.

  As the binder resin used for the protective layer, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, and siloxane resin can be used. Also, a copolymer of the above resin and a skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 and JP-A-10-252377 can be used.

The electrical resistance of the protective layer is usually in the range of 10 ⁹ Ω · cm to 10 ¹⁴ Ω · cm. If the electric resistance is higher than the above range, the residual potential is increased, resulting in an image with much fog. On the other hand, if the electric resistance is lower than the above range, the image is blurred and the resolution is reduced. Further, the protective layer must be configured so as not to substantially prevent transmission of light irradiated during image exposure.

  Further, for the purpose of reducing the frictional resistance and wear on the surface of the photoconductor, and increasing the transfer efficiency of the toner from the photoconductor to the transfer belt and paper, etc., the surface layer is made of fluorine resin, silicon resin, polyethylene resin, etc. Particles made of this resin or inorganic compound particles may be contained in the surface layer. Alternatively, a layer containing these resins and particles may be newly formed as a surface layer.

<Method for forming each layer>
Each layer constituting these photoreceptors is formed by immersing, coating, spraying, nozzle coating, bar coating, roll coating, blade coating, etc., on a support, a coating solution obtained by dissolving or dispersing a substance to be contained in a solvent. In this method, the coating and drying steps are sequentially repeated for each layer.

  There are no particular restrictions on the solvent or dispersion medium used in the preparation of the coating solution, but specific examples include alcohols such as methanol, ethanol, propanol and 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, dimethoxyethane and the like. Ethers, esters such as methyl formate and ethyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene and xylene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1, Chlorinated hydrocarbons such as 2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine , Nitrogen-containing compounds such as triethylenediamine, acetonitrile, N- methylpyrrolidone, N, N- dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide and the like. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds.

  The amount of the solvent or dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriate so that the physical properties such as solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to prepare. For example, in the case of a charge transport layer layer of a single layer type photoreceptor and a function separation type photoreceptor, the solid content concentration of the coating solution is usually 5% by weight or more, usually 5% by weight or more, preferably 10% by weight or more, Moreover, it is usually 40% by weight or less, preferably 35% by weight or less. Further, the viscosity of the coating solution is usually in the range of 10 cps or more, preferably 50 cps or more, and usually 500 cps or less, preferably 400 cps or less.

  In the case of a charge generating layer of a multilayer photoreceptor, the solid content concentration of the coating solution is usually 0.1% by weight or more, preferably 1% by weight or more, and usually 15% by weight or less, preferably 10% by weight. % Or less. The viscosity of the coating solution is usually 0.01 cps or more, preferably 0.1 cps or more, and usually 20 cps or less, preferably 10 cps or less.

  Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.

  The coating solution is preferably dried by touching at room temperature, followed by heating or drying in a temperature range of usually 30 ° C. or more and 200 ° C. or less for 1 minute to 2 hours, while still or blowing. The heating temperature may be constant or the heating may be performed while changing the temperature during drying.

<Image forming apparatus>
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

  As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.

  The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are disposed along the outer peripheral surface of the electrophotographic photosensitive member 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as corotron and scorotron, a direct charging device (contact type charging device) for charging a charged surface by contacting a direct charging member to which a voltage is applied, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose alternating current on direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. .

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

  The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicon resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.

  The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as silicon resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are disposed to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, and a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

  When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.

  The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

  In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.

  Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.
When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

  After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P. In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

  The electrophotographic photosensitive member 1 is combined with one or more of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7 to form an integrated cartridge ( The electrophotographic photosensitive member cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In this case, for example, when the electrophotographic photosensitive member 1 and other members are deteriorated, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

  Hereinafter, the present invention will be described in more detail with reference to production examples, examples and comparative examples. In addition, the following examples are shown in order to explain the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the gist thereof.

<Production of bishydrazone compound>
(Production Example 1: Production of Exemplified Compound CT-1)
Under a nitrogen atmosphere, 103 g of 4,4′-bis (m-tolylphenylamino) biphenyl is sometimes stirred with N, N-dimethylformamide (hereinafter referred to as DMF) at 90-100 ° C. with mechanical stirring. ) Dissolved in 775 ml. Thereafter, the mixture was cooled to 65 ° C., and 85 g of phosphorus oxychloride was slowly added dropwise while maintaining the temperature. After stirring, the mixture was cooled to room temperature. Subsequently, toluene and demineralized water were added and stirred for 1 to 2 hours, followed by liquid separation. Subsequently, the solvent in the organic layer was distilled off under reduced pressure, and tetrahydrofuran (hereinafter sometimes referred to as THF) was added. This solution was added dropwise to a methanol / water mixed solvent, and after filtration and drying, a diformyl product (yield 90%) was obtained as a yellow powder.

  Under a nitrogen atmosphere, 138 g of p, p′-ditolylamine was dissolved in 790 ml of acetic acid at 50 ° C. with mechanical stirring. Thereafter, the mixture was cooled to room temperature, 259 g of an aqueous solution of sodium nitrite was slowly added dropwise at the same temperature, and further stirred for 2 hours, followed by suction filtration. The obtained solid was washed with demineralized water / acetone mixed solvent and filtered. The solid was dried under reduced pressure to obtain a nitroso form (yield 93%) as yellow crystals.

  Under a nitrogen atmosphere, 35 g of the obtained nitroso form, 22 g of zinc powder and 200 ml of methanol were added to the reactor, and 37 ml of acetic acid was slowly added dropwise with stirring at room temperature. After about 2 hours, the reaction mixture was separated by suction filtration, and the filtrate was added dropwise to 250 ml of a THF solution containing 31 g of the diformyl body obtained in the above synthesis. Thereafter, heating and refluxing was continued for about 1 hour, and the mixture was cooled to room temperature to precipitate a solid. This solid was dissolved in a toluene / hexane mixed solution, and then separated and purified by column chromatography to obtain Exemplified Compound CT-1 as a yellow powder (yield 90%). The formation of this compound was confirmed by the nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) shown in FIG. In addition, this compound produces three types of isomers (represented by CT-1a, CT-1b and CT-1c). At this time, the production ratio of CT-1a is the highest.

(Production Example 2: Production of Exemplified Compound CT-3)
Under a nitrogen atmosphere, 154 g of N- (1-naphthyl) -N-phenylamine was dissolved in 791 ml of acetic acid with mechanical stirring at room temperature. Thereafter, 259 g of an aqueous sodium nitrite solution was slowly added dropwise and stirred, followed by suction filtration. The obtained solid was washed with demineralized water / acetone mixed solvent and filtered. The solid was dried under reduced pressure at 50 ° C. to obtain a nitroso form (90% yield) as yellow crystals.

  Under a nitrogen atmosphere, 38 g of the obtained nitroso form, 22 g of zinc powder, and 200 ml of methanol were added to the reactor, and 37 ml of acetic acid was slowly added dropwise with stirring at room temperature. After about 3 hours, the reaction mixture was separated by suction filtration, and the filtrate was added dropwise to a THF solution containing 32 g of the diformyl product obtained in Production Example 1. The heated reflux was continued for about 1 hour, and the mixture was cooled to room temperature to precipitate a solid. This solid was dissolved in a toluene / hexane mixed solution and then separated and purified by column chromatography to obtain Exemplified Compound CT-3 (yield 53%) as a yellow powder. The formation of this compound was confirmed by the nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) shown in FIG. In addition, this compound produces three types of isomers (represented by CT-3a, CT-3b and CT-3c). At this time, the production ratio of CT-3a is the highest.

(Production Example 3: Production of Exemplified Compound CT-6)
In a nitrogen atmosphere, 47 g of 4,4′-bis (N, N-diphenylamino) -di (3,3′-dimethyl) phenyl was added to 300 ml of DMF with mechanical stirring at 90 to 100 ° C. Dissolved. Then, it cooled to 65 degreeC, 41 g of phosphorus oxychloride was dripped slowly, maintaining temperature, and it cooled to room temperature after stirring. Subsequently, toluene and demineralized water were added and stirred for 1 to 2 hours, followed by liquid separation. Subsequently, the solvent of the organic layer was distilled off under reduced pressure, and then a THF solution was added. This solution was added dropwise to a methanol / water mixed solvent, and after filtration, drying, a diformyl product (yield 89%) was obtained as a yellow powder.

  Under a nitrogen atmosphere, 30 g of N-nitrosodiphenylamino, 24 g of zinc powder, and 200 ml of methanol were added to the reactor, and 42 ml of acetic acid was slowly added dropwise with stirring at room temperature. After about 2 hours, the reaction mixture was separated by suction filtration, and the filtrate was added dropwise to a THF solution containing 29 g of the diformyl product obtained in the above synthesis. Thereafter, heating and refluxing was continued in about 1 hour, and the mixture was cooled to room temperature to precipitate a solid. After dissolving in a toluene / hexane mixed solution, separation and purification were performed by column chromatography to obtain Exemplified Compound CT-6 (yield 68%) as a yellow powder. The formation of this compound was confirmed by the nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) shown in FIG.

(Production Example 4: Production of Exemplified Compound CT-7)
Under a nitrogen atmosphere, 27 g of 4,4′-bis (m, p′-ditolylamino) biphenyl was dissolved in 195 ml of DMF at 90-100 ° C. with mechanical stirring. Thereafter, the mixture was cooled to 65 ° C., and 21 g of phosphorus oxychloride was slowly added dropwise while maintaining the temperature. After stirring, the mixture was cooled to room temperature. Subsequently, toluene and demineralized water were added and stirred, followed by liquid separation. Subsequently, the solvent in the organic layer was distilled off under reduced pressure, and a THF solution was added. This solution was added dropwise to a methanol / water mixed solvent, and after filtration, drying, a diformyl product (yield 87%) was obtained as a yellow-green powder.

  Under a nitrogen atmosphere, 9 g of N-nitrosodiphenylamino, 7 g of zinc powder, and 100 ml of methanol were added to the reactor, and 13 ml of acetic acid was slowly added dropwise with stirring at room temperature. After about 2 hours, the reaction mixture was separated by suction filtration, and the filtrate was added dropwise to a THF solution containing 9 g of the diformyl body obtained in the above synthesis. Thereafter, heating and refluxing was continued in about 1 hour, and the mixture was cooled to room temperature to precipitate a solid. This solid was dissolved in a toluene / hexane mixed solution and then separated and purified by column chromatography to obtain Exemplified Compound CT-7 (yield 83%) as a yellow powder. The formation of this compound was confirmed by the nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) shown in FIG.

(Production Example 5: Production of exemplary compound CT-11)
Under a nitrogen atmosphere, 2,7-bis (N, N-diphenylamino) -9,9-dimethyl-9H-fluorene (26 g) was dissolved in 350 ml of DMF. Thereafter, the mixture was cooled to 65 ° C., and 21 g of phosphorus oxychloride was slowly added dropwise while maintaining the temperature. After stirring, the mixture was cooled to room temperature. Subsequently, toluene and demineralized water were added and stirred, followed by liquid separation. Subsequently, the solvent in the organic layer was distilled off under reduced pressure, and THF was added. This solution was added dropwise to methanol / water (v / v = 5: 1), and after filtration and drying, 27 g (yield 92%) of the diformyl product was obtained as a yellow powder.

  Under a nitrogen atmosphere, 28 g of N-nitrosodiphenylamino, 22 g of zinc powder and 200 ml of methanol were added to the reactor, and 39 ml of acetic acid was slowly added dropwise with stirring at room temperature. After about 2 hours, the reaction mixture was separated by suction filtration, and the filtrate was added dropwise to a THF solution containing 27 g of the diformyl product obtained in the above synthesis. Thereafter, heating and refluxing was continued in about 1 hour, and the mixture was cooled to room temperature to precipitate a solid. This solid was dissolved in a toluene / hexane mixed solution and then separated and purified by column chromatography to obtain Exemplified Compound CT-11 (yield 78%) as a yellow powder. The production of this compound was confirmed by the nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) shown in FIG.

<Production of electrophotographic photoreceptor>
(Example 1: Electrophotographic photoreceptor A1)
Using a conductive support in which an aluminum vapor-deposited layer (thickness 70 nm) is formed on the surface of a biaxially stretched polyethylene terephthalate resin film (thickness 75 μm), the following undercoat layer dispersion is formed on the aluminum vapor-deposited layer of the conductive support The liquid was applied by a bar coater so that the film thickness after drying was 1.25 μm and dried to form an undercoat layer.

  The undercoat layer dispersion was produced as follows. That is, a rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were flowed at high speed. In a mixed solvent of methanol / 1-propanol in a mixed solvent of methanol / 1-propanol, which was put into a high-pressure mixing kneader (“SMG300” manufactured by Kawata Co., Ltd.) and mixed at a high rotational speed of 34.5 m / sec Then, a dispersion slurry of hydrophobized titanium oxide was obtained by dispersing with a ball mill. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula (B Compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [in the following formula (E) The compositional molar ratio of the compound represented] is 75% / 9.5% / 3% / 9.5% / 3% of the copolymerized polyamide pellets with heating and stirring and mixing to dissolve the polyamide pellets. After that, by carrying out ultrasonic dispersion treatment, the weight ratio of methanol / 1-propanol / toluene is 7/1/2, and hydrophobically treated titanium oxide. The copolymerized polyamide in a weight ratio of 3/1, and a solid concentration of 18.0% of the undercoat layer dispersion.

  Separately, type A oxytitanium phthalocyanine (showing diffraction peaks at 9.3 °, 10.6 °, and 26.3 ° at Bragg angles (2θ ± 0.2 °) in the X-ray diffraction spectrum for CuKα characteristic X-ray) 10 Part by weight was added to 150 parts by weight of 4-methoxy-4-methyl-2-pentanone, and pulverized and dispersed in a sand grind mill for 1 hour. Thereafter, 100 parts by weight of a 5 wt% 1,2-dimethoxyethane solution of polyvinyl butyral (“Denkabutyral # 6000C” manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder resin, and phenoxy resin (“PKHH” manufactured by Union Carbide) A coating solution for a charge generation layer was prepared by adding 100 parts by weight of a 5 wt% 1,2-dimethoxyethane solution. The charge generation layer coating solution was applied onto the undercoat layer of the conductive support with a bar coater so that the film thickness after drying was 0.4 μm, and dried to form a charge generation layer. .

  Separately, 50 parts by weight of Exemplified Compound CT-1 obtained in Production Example 1 as a charge transport material, 100 parts by weight of binder resin, and 0.03 parts by weight of silicone oil as a leveling agent were added to tetrahydrofuran / toluene = A charge transport layer coating solution was prepared by dissolving in 640 parts by weight of an 8/2 (weight ratio) mixed solvent. In addition, as binder resin, the repeating unit A51 mol% which uses the following 2, 2-bis (4-hydroxy-3-methylphenyl) propane as an aromatic diol component, and 1,1-bis (4-hydroxyphenyl) A polycarbonate resin (viscosity average molecular weight 30000) having a terminal structure derived from pt-butylphenol, comprising 49 mol% of a repeating unit B having -1-phenylethane as an aromatic diol component, was used.

  The charge transport layer coating solution is applied on the charge generation layer with a film applicator so that the film thickness after drying is 20 μm, dried to form a charge transport layer, and an electron having a laminated photosensitive layer Photoreceptor A1 was produced.

(Example 2: Electrophotographic photoreceptor A2)
An electrophotographic photosensitive member A2 as an example was obtained in the same manner as in Example 1 except that CT-3 was used as a charge transport material instead of the exemplified compound CT-1.

(Example 3: Electrophotographic photoreceptor A3)
An electrophotographic photoreceptor A3 as an example was obtained in the same manner as in Example 1 except that CT-6 was used as a charge transport material instead of the exemplified compound CT-1.

(Example 4: Electrophotographic photoreceptor A4)
An electrophotographic photoreceptor A4 as an example was obtained in the same manner as in Example 1 except that CT-7 was used as a charge transport material instead of the exemplified compound CT-1.

(Example 5: electrophotographic photoreceptor A5)
An electrophotographic photoreceptor A5 as an example was obtained in the same manner as in Example 1 except that CT-11 was used as the charge transport material instead of the exemplified compound CT-1.

(Comparative Example 1: Electrophotographic photoreceptor P1)
An electrophotographic photoreceptor P1 as a comparative example was obtained in the same manner as in Example 1 except that the following charge transport material W exemplified in Patent Document 2 was used in place of the exemplified compound CT-1.

(Comparative Example 2: Electrophotographic photoreceptor P2)
An electrophotographic photoreceptor P2 as a comparative example was obtained in the same manner as in Example 1 except that the following charge transport material X exemplified in Patent Document 1 was used in place of the exemplified compound CT-1.

(Comparative Example 3: Electrophotographic photoreceptor P3)
An electrophotographic photosensitive member P3 as a comparative example was obtained in the same manner as in Example 1 except that the following charge transport material Y exemplified in Patent Document 1 was used in place of the exemplified compound 1. However, it was confirmed that the preparation of the coating solution requires heat dissolution, and the charge transport material Y has difficulty in solubility. Further, crystallization was observed in a part of the photoconductor, and the measurement of characteristics was not achieved.

(Comparative Example 4: Electrophotographic photoreceptor P4)
An electrophotographic photosensitive member P4 as a comparative example was obtained in the same manner as in Example 1 except that the following charge transport material Z exemplified in Patent Document 2 was used in place of the exemplified compound 1.

<Evaluation of electrical characteristics of electrophotographic photoreceptor>
The electrophotographic characteristics of the obtained electrophotographic photoreceptors A1 to A5 and P1 to P4 were measured by a static method as follows using a photoreceptor evaluation apparatus (Cynthia-55, manufactured by Gentec Corporation). First, the electrophotographic photosensitive member is discharged in a dark place with a scorotron charger so that the surface potential is about − (minus, the same applies hereinafter) to 700 V, and passes through the electrophotographic photosensitive member at a constant speed (125 mm / sec). The charged voltage was measured, the charged voltage was measured, and the initial charged voltage (V0) was obtained. Thereafter, the potential drop (DDR) was measured when left for 2.5 seconds. Next, irradiation with 780 nm monochromatic light having an intensity of 1.0 μW / cm ² , half-exposure energy E1 / 2 (μJ / cm ² ) required until the photoreceptor surface potential is changed from −550 V to −275 V, and irradiation The residual potential (Vr) after 10 seconds was determined.

  Table 1 shows the evaluation results of the electrophotographic photoreceptors A1 to A5 and P1 to P4.

(Example 6)
Using Example Compound CT-7 as a charge transport material, the electric field strength E = 2e + 5 (V / cm) of the charge transport layer and the hole drift mobility at a temperature of 21 ° C. were measured by the TOF method.

(Comparative Example 5)
The hole drift mobility was determined in the same manner as in Example except that the charge transport material a exemplified in Patent Document 2 was used instead of the novel bishydrazone compound CT-7 of this patent used in Example 6 above. Measured by TOF method.

  Table 2 shows the hole drift mobility of each of the electrophotographic photoreceptors A4 and P5.

  As described above, in Comparative Example 3, the charge transport material Y had low solubility, and a good electrophotographic photosensitive member could not be produced. In Examples 1 to 5, the arylamine compound of the present invention Exemplified compounds CT-1, CT-3, CT-6, CT-7, and CT-11 having high solubility exhibited good electrophotographic photoreceptors A1 to A5.

  Further, as shown in Table 1, the electrophotographic photoreceptors A1 to A5 have a half-exposure energy smaller than that of the electrophotographic photoreceptors P1, P2, or P4, and a residual voltage Vr after 10 seconds of irradiation. Therefore, the electrophotographic photoreceptors A1 to A5 using the exemplary compounds CT-1, CT-3, CT-6, CT-7, and CT-11, which are the bishydrazone compounds of the present invention, as charge transport materials, have the conventional charge. It was confirmed that the electrophotographic photosensitive member using the transport materials W, X, Y, and Z exhibits better electrical characteristics.

  Furthermore, the electrophotographic photoreceptor A4 using the exemplified compound CT-7, which is the bishydrazone compound of the present invention, as a charge transport material has a mobility higher than that of the electrophotographic photoreceptor using the charge transport material a of the comparative example. There was no discoloration and the electrical characteristics were good.

  The present invention can be carried out in any field that requires an electrophotographic photoreceptor, and is suitable for use in, for example, a copying machine, a printer, a printing machine, and the like.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. It is a nuclear magnetic resonance spectrum (300 MHz) of exemplary compound CT-1 of the present invention. It is a nuclear magnetic resonance spectrum (300 MHz) of exemplary compound CT-3 of the present invention. It is a nuclear magnetic resonance spectrum (300 MHz) of exemplary compound CT-6 of the present invention. It is a nuclear magnetic resonance spectrum (300 MHz) of an exemplary compound CT-7 of the present invention. It is a nuclear magnetic resonance spectrum (300 MHz) of exemplary compound CT-11 of the present invention.

Explanation of symbols

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
DESCRIPTION OF SYMBOLS 5 Transfer apparatus 6 Cleaning apparatus 7 Fixing apparatus 41 Developing tank 42 Agitator 43 Supply roller 44 Developing roller 45 Control member 71 Upper fixing member (fixing roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (3)

A bishydrazone compound having a triarylamine skeleton represented by the following general formula [1].

(In the general formula [1], A _{1 to} A ₆ each represents an aryl group which may have a substituent. B _{1 to} B ₄ each represents an arylene group which may have a substituent. Provided that (1) one of B _{1 to} B ₄ has a substituent; (2) _one of A ₁ and A ₂ has a substituent, and A _{3 to} A ₆ One of them has a substituent; (3) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ is an aryl group other than a phenyl group Satisfying at least one of the following conditions.) In an electrophotographic photosensitive member in which a photosensitive layer containing a charge generating material and a charge transport material is provided on a conductive support, the bishydrazone compound represented by the following general formula [1] is contained as the charge transport material. An electrophotographic photoreceptor characterized by the above.

(In the general formula [1], A _{1 to} A ₆ each represents an aryl group which may have a substituent. B _{1 to} B ₄ each represents an arylene group which may have a substituent. Provided that (1) one of B _{1 to} B ₄ has a substituent; (2) _one of A ₁ and A ₂ has a substituent, and A _{3 to} A ₆ One of them has a substituent; (3) _one of A ₁ and A ₂ has a substituent, and one of A _{3 to} A ₆ is an aryl group other than a phenyl group Satisfying at least one of the following conditions.) An electrophotographic photosensitive member, a charging portion that charges the electrophotographic photosensitive member, an exposure portion that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, and is formed on the electrophotographic photosensitive member by exposure. An image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed using toner, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. Forming equipment.

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