JP2014095868A - Electrophotographic photoreceptor containing compound having new butadiene skeleton, electrophotographic photoreceptor cartridge, image forming apparatus, and compound having new butadiene skeleton - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that contains a low-molecular weight butadiene compound that can be suitably used for a photosensitive layer, has good compatibility with a binder resin, and has excellent charge transport ability; has good electric characteristics; and suppresses poor cleaning, filming, stains, afterimages (ghosts), and a reduction in density after the repeated use; an electrophotographic cartridge that uses the electrophotographic photoreceptor, and prevents the occurrence of blade inversion and the generation of rubbing noise during printing; and an image forming apparatus.SOLUTION: An electrophotographic photoreceptor has a photosensitive layer on a conductive support; and the photosensitive layer contains at least one butadiene compound having a structure represented by the following general formula (1) or (2).

Description

  The present invention relates to an electrophotographic photosensitive member containing a novel butadiene compound that can be suitably used as a photoconductive material for an electrophotographic photosensitive member in a photosensitive layer, an electrophotographic cartridge using the electrophotographic photosensitive member, and an image forming apparatus. About.

The electrophotographic technique is widely used in the fields of copiers, various printers, printing machines, etc. because it is excellent in immediacy and provides high-quality images. As an electrophotographic photoreceptor that is the core of electrophotographic technology, an electrophotographic photoreceptor using an organic photoconductive material (hereinafter simply referred to as “photosensitive material”) that has advantages such as non-pollution, easy film formation, and easy manufacture. Also referred to as "body").
In recent years, the use of image forming apparatuses such as electrophotographic copying machines has been expanded, and the market demand for image quality has been increasing. In particular, in office documents, in addition to the development of mapping technology and latent image forming technology for input, the types of character hieroglyphics are more abundant and finer at the time of output. Due to the spread and development, the reproducibility of a latent image with extremely high image quality that has few defects and unclearness in printed images is required.

  Furthermore, it is a common recognition in the industry that with the recent high performance and low cost of electrophotographic equipment, it is essential to increase the sensitivity of the electrophotographic photosensitive member and reduce the cost of the original material. Of 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 a good matching with it. It is necessary to develop charge transport materials that can be purified by reaction routes and simple purification steps. For this reason, high performance of charge transport materials having a low molecular weight has been attracting attention. The low molecular weight organic photoconductive material has the advantage of low production cost, and the physical properties or electrophotographic characteristics of the coating can be controlled by selecting the type and composition ratio of the binder to be used together. This is preferable because it is relatively easy.

As a conventional technique, a triarylamine-butadiene conjugated compound can be used as a charge transport material. For example, it has been proposed that triarylamine-butadiene conjugated compounds (hereinafter also simply referred to as “butadiene compounds”) described in Patent Documents 1 and 2 can be used as charge transport materials.
However, the compound described in Patent Document 1 has a point to be improved in electrical characteristics or has a problem in compatibility with the binder resin, and when used in a high number of parts, a problem of crystal precipitation is likely to occur. It was. Further, the compound described in Patent Document 2 has a relatively slow mobility,
There is a point that should be improved in electrical characteristics, and when it is used repeatedly, deterioration of electrical stability such as a decrease in chargeability and an increase in residual potential, and a resulting image defect occur.

Furthermore, the compound groups described in Patent Documents 1 and 2 are prone to problems such as filming, blade reversal, and rubbing noise when repeatedly mounted on an electrophotographic apparatus and used repeatedly. This problem is particularly remarkable when a suspension polymerization toner having a large circularity is used.
As described above, there is almost no low molecular weight organic compound having practically good characteristics for producing a photoreceptor.

Japanese Patent Publication No. 5-046939 JP-A-1-274153

  The present invention has been made in view of such a current situation, and the object thereof is to have good compatibility with a binder resin that can be suitably used for a photosensitive layer of an electrophotographic photosensitive member, and excellent charge transport ability. Another object of the present invention is to provide an electrophotographic photoreceptor containing a low molecular weight butadiene compound, having good electrical characteristics, and having few cleaning defects, filming, dirt, afterimage (ghost), density reduction, and the like when repeatedly used. Another object of the present invention is to provide an electrophotographic cartridge and an image forming apparatus that do not generate blade reversal and rubbing noise during printing using this electrophotographic photosensitive member.

The present inventor has introduced an ortho-substituted alkoxy group or a para-substituted N, N-dialkylamino group into a phenyl group at the butadiene terminal of a triarylamine-butadiene conjugated compound as a charge transport material. When used in an electrophotographic photoreceptor, properties such as compatibility with binder resin, photosensitivity, and residual potential are improved relatively well, and there are few cleaning defects, filming, dirt, afterimage (ghost), density reduction, etc. An electrophotographic photosensitive member can be provided, and by using this electrophotographic photosensitive member, it is possible to provide an electrophotographic cartridge and an image forming apparatus that do not generate blade reversal and rubbing noise during printing. The headline and the present invention were completed.

That is, the first gist of the present invention is that in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer has a structure represented by the following general formula [1] or [2]. An electrophotographic photoreceptor comprising at least one butadiene compound (claim 1).

(In the above formula [1] or [2], Ar ^{1 to} Ar ⁴ are the substituent constants σp in Hammett's rule, respectively.
Represents an aryl group which may have an organic group having 1 to 4 carbon atoms of 0.20 or less, Y represents an alkyl group having 1 to 4 carbon atoms, and R represents an alkyl group having 2 to 4 carbon atoms . However, out of Ar ¹ and Ar ²
Alternatively, at least one of Ar ³ and Ar ⁴ is an aryl group having the above substituent. )
The second gist of the present invention is that the electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and exposing the image to the charged electrophotographic photosensitive member to form an electrostatic latent image. Image exposing means, developing means for developing the electrostatic latent image with toner, transfer means for transferring the toner to the transfer target, fixing means for fixing the toner transferred to the transfer target, and the electrophotography An electrophotographic cartridge comprising at least one selected from cleaning means for collecting the toner adhering to the photosensitive member (claim 2).

The third aspect of the present invention is to form an electrostatic latent image by exposing the electrophotographic photosensitive member of the present invention, a charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member. An image forming apparatus comprising: an exposure unit; a developing unit that develops the electrostatic latent image with toner; and a transfer unit that transfers the toner to a transfer target (claim 3).
The fourth gist of the present invention resides in a butadiene-based compound having a structure represented by the following general formula [1] (Claim 4).

(In the formula [1], Ar ^{1 to} Ar ² each represents an aryl group which may have an organic group having 1 to 4 carbon atoms having a substituent constant σp in the Hammett rule of 0.20 or less, and Y is An alkyl group having 1 to 4 carbon atoms, wherein at least one of Ar ¹ and Ar ² is an aryl group having the substituent.

  The low molecular weight butadiene-based compound of the present invention has relatively good properties such as compatibility with the binder resin, photosensitivity, and residual potential, and when incorporated in the photosensitive layer of an electrophotographic photosensitive member, poor cleaning, filming, It is possible to provide an electrophotographic photosensitive member with less contamination, afterimage (ghost), density reduction, and the like. Also, by using this electrophotographic photosensitive member, it is possible to provide an electrophotographic cartridge and an image forming apparatus that do not generate blade reversal and rubbing noise during printing.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine used in Examples. 1 is an X-ray diffraction pattern of oxytitanium phthalocyanine used in Examples. It is a nuclear magnetic resonance spectrum of exemplary compound CT-1 of the present invention. It is a nuclear magnetic resonance spectrum of exemplary compound CT-8 of the present invention. It is a nuclear magnetic resonance spectrum of exemplary compound CT-9 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the present invention. it can.
≪Butadiene compound≫
The butadiene compound of the present invention is a compound having a structure represented by the following general formula [1] or [2].

(In the above formula [1] or [2], Ar ^{1 to} Ar ⁴ are the substituent constants σp in Hammett's rule, respectively.
Represents an aryl group which may have an organic group having 1 to 4 carbon atoms of 0.20 or less, Y represents an alkyl group having 1 to 4 carbon atoms, and R represents an alkyl group having 2 to 4 carbon atoms . However, out of Ar ¹ and Ar ²
Alternatively, at least one of Ar ³ and Ar ⁴ is an aryl group having the above substituent. )
Here, Hammett's rule is an empirical rule used to explain the effect of a substituent in an aromatic compound on the electronic state of the aromatic ring, and the substituent constant σp of the substituted benzene is the electron donation / It can be said that this is a value obtained by quantifying the degree of suction. If the σp value is positive, the substituted benzoic acid is more acidic than the unsubstituted one, that is, an electron-withdrawing substituent. Conversely, when the σp value is negative, an electron donating substituent is formed. Table 1 shows σp values of representative substituents (The Chemical Society of Japan, “Chemical Handbook, Basic Edition II, 4th revised edition”, Maruzen Co., Ltd., published on September 30, 1993, p.364-365). .

In the formula [1] or [2], Ar ^{1 to} Ar ⁴ are each a substituent constant σp in the Hammett rule.
Is an aryl group which may have an organic group having 1 to 4 carbon atoms of 0.20 or less. The value of the substituent constant σp in the Hammett rule is preferably 0.00 or less, and particularly preferably −0.10 or less from the viewpoint of electrical characteristics. On the other hand, the lower limit is preferably −0.3 or more from the viewpoint of acid resistance. Examples of the organic group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a dialkylamino group having 1 to 2 carbon atoms, and specifically include a methyl group and an ethyl group. N-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, methoxy group, ethoxy group, propoxy group, butoxy group, N, N-dimethylamino group, N, N-diethylamino group, etc. Can be mentioned. Among these, an organic group having 1 to 2 carbon atoms is particularly preferable from the viewpoint of electrical characteristics and production cost, and specific examples include a methyl group, a methoxy group, an ethyl group, and an ethoxy group.

In the above formula [1] or [2], Ar ^{1 to} Ar ⁴ represent an aromatic hydrocarbon group, and when Ar ^{1 to} Ar ⁴ is a monocyclic hydrocarbon group, a phenyl group may be mentioned, In the case where Ar ^{1 to} Ar ⁴ are condensed polycyclic hydrocarbons, a naphthyl group, a fluorenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, and the like can be given. Among these, a phenyl group, a fluorenyl group, and a naphthyl group are preferable in terms of electrical characteristics, and a fluorenyl group is more preferable. In view of both electrical characteristics and production cost, Ar ^{1 to} Ar ⁴ are particularly preferably phenyl groups. The position of the substituent is preferably the ortho position or the para position, and particularly preferably the para position, based on the nitrogen atom from the viewpoint of electrical characteristics.

In said formula [1], Y is a C1-C4 alkyl group. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, methoxy group, ethoxy group, propoxy group, butoxy group, N, N-dimethylamino Group, N, N-diethylamino group and the like. Above all, from the aspect of electrical characteristics and manufacturing cost, carbon number 1
These organic groups are particularly preferred, and specific examples include a methyl group and a methoxy group.

  In the formula [2], R is an alkyl group having 2 to 4 carbon atoms, and examples thereof include an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. From the viewpoint of electrical characteristics, R is particularly preferably an ethyl group. If the alkyl group has 2 or less carbon atoms, that is, if it is a methyl group, it cannot be used due to poor compatibility with the binder resin, and if the alkyl group has 5 or more carbon atoms, the electrical characteristics and acid gas resistance deteriorate. There is a risk that.

The molecular weight of the formula [1] or [2] is usually 515 or less, preferably 480 or less. When this range is satisfied, the cleaning performance is improved when the actual image is evaluated, and it is easy to prevent noise and filming. This is presumably because the surface hardness of the photoreceptor is high by using a low molecular charge transport material. Therefore, in the formula [1] or [2], it is particularly preferable to adjust the substituents of Ar ^{1 to} Ar ⁴ , Y, R, etc. in view of the molecular weight. On the other hand, the lower limit is preferably 400 or more from the viewpoint of electrical characteristics.

As typical examples of the butadiene-based compound represented by the formula [1], the following exemplified compounds CT-1 to CT-7 can be mentioned. However, the butadiene compound related to the present invention is not limited to these compounds.

  As typical examples of the butadiene-based compound represented by the formula [2], the following exemplified compounds CT-8 to CT-14 are exemplified. However, the butadiene compound related to the present invention is not limited to these compounds.

These butadiene compounds can be easily synthesized by known methods. For example, exemplary compound CT-1 of the present invention can be produced according to the following reaction scheme 1 (
Production Example 1).
[Scheme 1]

(Formylmethyl) triphenylphosphonium chloride (reagent B) and aldehyde derivative (A) are dissolved in dimethylformamide (hereinafter referred to as DMF), and 28% sodium methoxide in methanol is slowly added to react. Derivative (D) is obtained. It was condensed by adding the Wordsworth reagent (C) dropwise, and further adding a base,
A butadiene precursor (E) can be obtained. The diarylamine derivative (F) can be condensed in the presence of a palladium-trialkylphosphine complex catalyst to obtain the target charge transport material CT-1.

≪Electrophotographic photoreceptor≫
The configuration of the electrophotographic photosensitive member of the present invention will be described below. If the electrophotographic photoreceptor of the present invention is provided with a photosensitive layer containing a butadiene compound represented by the above formula [1] or [2] on a conductive support, the structure is as follows. There is no particular limitation. Among these, a laminated type photoreceptor in which a charge generation layer and a charge transport layer are laminated is preferable, and in particular, the charge transport layer of the laminated type photoreceptor is represented by the above-described formula [1] or [2]. It is preferable to contain a butadiene compound.

<Conductive support>
There are no particular restrictions on the conductive support, but for example, metal materials such as aluminum, aluminum alloys, stainless steel, copper and nickel, and conductive powders such as metal, carbon and tin oxide can be added to make the conductive material conductive. Mainly used are resin, glass, paper, or the like obtained by depositing or applying the applied resin material or a conductive material such as aluminum, nickel, ITO (indium tin oxide) on the surface. These may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and arbitrary ratios. As a form of the conductive support, a drum form, a sheet form, a belt form or the like is used. Furthermore, 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 conductive 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 size with the material constituting the conductive 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 or a resin in which particles such as a metal oxide are dispersed is used. The undercoat layer may be a single layer or a plurality of layers.

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 substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance 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 metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is preferably 10 nm or more and 100 nm or less, and particularly 10 nm or more and 50 nm or less. preferable. This average primary particle size can be obtained from a TEM photograph or the like.

  The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. The binder resin used for the undercoat layer is epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, polyimide resin, chloride resin. Cellulose esters such as vinylidene resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacryl resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitrocellulose Resin, cellulose ether resin, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate compound, zirconium The organic zirconium compound alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanium alkoxide compounds include known binder resins such as a silane coupling agent. 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. From the viewpoint of the stability of the dispersion and the coating property, the binder resin is usually 10% by mass or more, It is preferable to use in the range of 500 mass% or less.
The thickness of the undercoat layer is arbitrary as long as the effects of the present invention are not significantly impaired, but the viewpoint of improving the electrical characteristics, strong exposure characteristics, image characteristics, repeat characteristics, and coating properties during production of the electrophotographic photosensitive member. Therefore, it is usually 0.01 μm or more, preferably 0.1 μm or more, and usually 30 μm or less, preferably 20 μm or less. 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 included.

<Photosensitive layer>
The photosensitive layer is formed on the above-mentioned conductive support (or on the undercoat layer when the above-described undercoat layer is provided). The photosensitive layer is a layer containing a butadiene compound represented by the general formula [1] or [2] described above, and includes a charge generation material and a charge transport material (including a butadiene compound). A single layer structure in which the charge generation material is dispersed in the binder resin (hereinafter referred to as “single layer type photosensitive layer” as appropriate), a charge generation layer in which the charge generation material is dispersed in the binder resin, A function-separated type layered structure composed of two or more layers, including a charge transport layer in which a charge transport material (including a butadiene compound) is dispersed in a binder resin (hereinafter referred to as “laminated photosensitive layer” as appropriate). ), But any form may be used.
In addition, as the laminated photosensitive layer, a charge-generating layer and a charge transport layer are laminated in this order from the conductive support side, and conversely, a charge transport layer and a charge generation layer are formed from the conductive support side. There are reverse laminated photosensitive layers provided in order, and any of them can be adopted, but a forward laminated photosensitive layer that can exhibit the most balanced photoconductivity is preferable.

<Laminated photosensitive layer>
[Charge generation layer]
The charge generation layer of the laminated photosensitive layer (function-separated type photosensitive layer) contains a charge generation material and usually contains a binder resin and other components used as necessary. Such a charge generation layer is prepared, for example, by dissolving or dispersing a charge generation material and a binder resin in a solvent or dispersion medium to prepare a coating solution, and in the case of a sequentially laminated photosensitive layer, this is formed on a conductive support. (If an undercoat layer is provided, it can be obtained on the undercoat layer). In the case of a reverse laminated type photosensitive layer, it can be obtained by coating on a charge transport layer and drying.

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. Organic photoconductive materials are preferred, and organic photoconductive materials are particularly preferable. Pigments are 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, phthalocyanine pigments or azo pigments are particularly preferable. 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 using a phthalocyanine pigment as a charge generation material, specifically, metal such as metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, aluminum, or oxides thereof, halides, Those having each crystal form of coordinated phthalocyanines such as hydroxides 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 hydroxygallium phthalocyanine, hydroxygallium phthalocyanine having the strongest peak at 28.1 °, or 26. Hydroxygallium phthalocyanine having no peak at 2 °, 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.

  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 laser beam having a relatively long wavelength, for example, a laser beam having a wavelength around 780 nm. Further, when an azo pigment such as monoazo, diazo, or trisazo is used, white light, laser light having a wavelength around 660 nm, or laser light having a relatively short wavelength (for example, a wavelength in the range of 380 nm to 500 nm). It is possible to obtain a photoreceptor having sufficient sensitivity to the laser beam).

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or the mixed state in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. It may be the one that gave rise to. 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.

  On the other hand, when an azo pigment is used as a charge generation material, various known azo pigments can be used as long as they have sensitivity to a light source for light input. 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 materials having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region. Among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are preferably used in combination. More preferred.

The binder resin used for the charge generation layer constituting the multilayer photosensitive layer is not particularly limited. For example, polyvinyl butyral resin, polyvinyl formal resin, partially acetalized polyvinyl butyral resin in which part of butyral is modified with formal, acetal, or the like. Polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, etc. Polyacrylamide resin, polyamide resin, polyvinyl pyridine resin, cellulose resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, Vinyl chloride such as zein, vinyl chloride-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer -Insulating resin such as vinyl acetate copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicon-alkyd resin, phenol-formaldehyde resin, and poly-N-vinylcarbazole , Organic photoconductive polymers such as polyvinyl anthracene and polyvinyl 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 a charge generation material in a solution obtained by dissolving the above-described binder resin in an organic solvent to prepare a coating solution, which is then formed on a conductive support (when an undercoat layer is provided). Is formed by coating (on the undercoat layer).
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, 4-methoxy-4-methyl-2-pentanone, methyl formate, ethyl acetate, Acetic acid n-bu Chains such as ester solvents such as benzene, halogenated hydrocarbon solvents such as methylene chloride, chloroform, 1,2-dichloroethane, diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve, etc. Or cyclic ether solvents, acetonitrile, dimethyl sulfoxide, sulfolane, aprotic polar solvents such as hexamethylphosphoric triamide, n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, triethylamine-containing nitrogen Compound, mineral oil such as ligroin, water and the like. 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 (mass ratio) of the binder resin and the charge generation material is usually 10 parts by mass or more, preferably 30 parts by mass or more, and usually 1000 parts by mass with respect to 100 parts by mass of the binder resin. The range is not more than part by mass, preferably not more than 500 parts by mass. The film thickness of the electrification generation layer is usually in the range of 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. On the other hand, if the ratio of the charge generating substance is too low, the sensitivity as a photoreceptor may be reduced.

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 dissolving or dispersing a charge transport material or the like and a binder resin in a solvent to prepare a coating solution. In addition, in the case of a reverse lamination type photosensitive layer, it can be obtained by coating and drying on a conductive support (on the undercoat layer when an undercoat layer is provided).

As the charge transport material, an alkoxy group-substituted isomer mixture of the butadiene-based compound of the present invention is preferably used. As the butadiene-based compound of the present invention, the same compounds may be used alone, or a plurality of compounds may be combined at an arbitrary ratio.
In addition to the butadiene 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, enamine derivatives, stilbene derivatives, and those in which a plurality of these derivatives are bonded are preferable. More specifically, it is described in JP-A-2-230255, JP-A-63-225660, JP-A-58-198043, JP-B-58-32372, and JP-B-7-21646. Compounds are preferably used. Any of these charge transport materials may be used alone, or a plurality of types may be used in any combination. When the butadiene compound of the present invention is used in combination with another known charge transport material, the content ratio (% by mass) of the charge transport material to be used in the total amount of the charge transport material is not particularly limited, but is 1% or more. It is preferably within the range of 20% or less, and particularly preferably within the range of 3% or more and 10% or less in order to more effectively exert the role of the butadiene compound of the present invention.

  Specific examples of suitable structures of the charge transport material are shown below. These specific examples are shown for illustration, and any known charge transporting material may be used as long as it does not contradict the gist of the present invention.

  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. Polymer, 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 -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.

  Specific examples of suitable structures of the binder resin are shown below. These specific examples are shown for illustration, and any known binder resin may be mixed and used as long as it does not contradict the gist of the present invention.

  As for the ratio of the binder resin to the charge transport material, the charge transport material is used in a ratio of 20 parts by mass or more with respect to 100 parts by mass of the binder resin. Among these, 30 parts by mass or more is preferable from the viewpoint of residual potential reduction, and 40 parts by mass 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 mass or less. Among these, 110 parts by mass or less is preferable from the viewpoint of compatibility between the charge transport material and the binder resin, 90 parts by mass or less is more preferable from the viewpoint of printing durability, and 80 parts by mass 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, on the other hand, 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 order to ensure film strength, in the same manner as the charge transport layer of the multilayer photoconductor, 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. A charge generation material is further dispersed in a charge transport medium comprising these charge transport materials and a 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. The total amount of the layer-type photosensitive layer is usually 0.5% by mass or more, preferably 1% by mass or more, and usually 50% by mass or less, preferably 20% by mass or less.
In addition, the usage ratio of the binder resin and the charge generation material in the single-layer type photosensitive layer is such that the charge generation material is usually 0.1 parts by mass or more, preferably 1 part by mass or more, and usually 100 parts by mass of the binder resin It is 30 mass parts or less, Preferably it is set as the range of 10 mass parts 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, stain resistance, gas resistance, light resistance, etc., in both the photosensitive layer and each layer constituting it, both in 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 the photosensitive layer from being worn out or preventing or reducing the 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 a copolymer using a compound having charge transporting ability such as a triphenylamine skeleton described in JP-A-9-190004. Can be formed.

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 skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 and a copolymer of the above resin 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. When the electric resistance is higher than the range, the residual potential is increased, resulting in an image with much fogging. On the other hand, when the electric resistance is lower than the 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, or the like. You may contain the particle | grains which consist of these resin, and the particle | grains of an inorganic compound. Alternatively, a layer containing these resins and particles may be newly formed as a surface layer.

<Method for forming each layer>
Each layer constituting the above-described photoreceptor is formed by dip coating, spray coating, nozzle coating, bar coating, roll coating, blade coating on a conductive support obtained by dissolving or dispersing a substance to be contained in a solvent. It is formed by repeating a coating / drying step sequentially for each layer by a known method such as coating.

There are no particular restrictions on the solvent or dispersion medium used for 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, acetone, methyl ethyl ketone, cyclohexanone, ketones such as 4-methoxy-4-methyl-2-pentanone, aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, Chlorinated hydrocarbons such as chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, Diethyl Min, triethanolamine, ethylenediamine, nitrogen-containing compounds such as triethylenediamine, acetonitrile, N- methylpyrrolidone, N, N
-Aprotic polar solvents such as dimethylformamide and dimethyl sulfoxide. 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 the 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 appropriately determined so that the physical properties such as the solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
For example, in the case of a charge transport layer of a single layer type photoreceptor or a function separation type photoreceptor, the solid content concentration of the coating solution is usually 5% by mass or more, preferably 10% by mass or more, and usually 40% by mass or less. The range is preferably 35% by mass or less. Further, the viscosity of the coating solution is usually 10 mPa · s or higher, preferably 50 mPa · s or higher, and usually 500 mPa · s or lower, preferably 400 mPa · s or lower, at the temperature during use.

  In the case of a charge generation layer of a multilayer photoreceptor, the solid content concentration of the coating solution is usually 0.1% by mass or more, preferably 1% by mass or more, and usually 15% by mass or less, preferably 10% by mass. % Or less. In addition, the viscosity of the coating solution is usually 0.01 mPa · s or higher, preferably 0.1 mPa · s or higher, and usually 20 mPa · s or lower, preferably 10 mPa · s or lower, at the temperature during use.

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. Further, the heating temperature may be constant, or heating may be performed while changing the temperature during drying.

≪Image forming device≫
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 arranged along the outer peripheral surface of the electrophotographic photoreceptor 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. As the charging device, a corona charging device such as a corotron or a scorotron, a direct charging device (contact type charging device) for charging a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and the like are often used. Examples of the direct charging device include a charging roller and a charging brush. 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 an alternating current on a 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, if exposure is performed with monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength of 600 nm to 700 nm, slightly shorter wavelength, monochromatic light with a wavelength of 380 nm to 500 nm, or the like. Good.

  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. This 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 a 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 toner T is arbitrary, and in addition to the powdery toner, a polymerized toner using a suspension polymerization method, an emulsion polymerization method, or the like can be used. In particular, when a polymerized toner is used, a toner having a small particle diameter of about 4 to 8 μm is preferable, and the toner particles are used in various shapes ranging from a nearly spherical shape to a shape outside the spherical shape on the potato. be able to. The polymerized toner is excellent in charging uniformity and transferability and is suitably used for high image quality.

  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 disposed so as 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. The upper and lower fixing members 71 and 72 are known heat fixings such as 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, or 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 silicon 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 an arbitrary method such as heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

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 be configured to perform, 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 the 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 butadiene compounds>
(Production Example 1: Production of Exemplified Compound CT-1)
Under a nitrogen atmosphere, 11.25 g (33 mmol) of (formylmethyl) triphenylphosphonium chloride (reagent D) and 4.08 g (30 mmol) of the aldehyde derivative (A) were dissolved in DMF, and 6.95 g of 28% sodium methoxide in methanol Sinamylaldehyde derivative (D) is synthesized by slowly adding (36 mmol) to the reaction. It was mixed with 10.13 g (33 mmol) of Wordsworth (reagent C), and 4.04 g (36 mmol) of potassium tert-butoxide was slowly added (cooled as necessary) and stirred for an additional hour. This solution was dropped into 500 ml of a methanol / ice water (v / v = 8: 2) mixed solution and crystallized. The obtained crystals were dried at 70 ° C. under reduced pressure to give 7.72 g (24.5 mmol, butadiene precursor (E)
Yield 82%) was obtained as white crystals.

Under nitrogen atmosphere, 7.72 g (24.5 mmo) of butadiene precursor (E) and 5.32 g (26.9 mmol) of diarylamine derivative (F), 100 ml of xylene, 2.83 g (29.4 mmol) of sodium-tert-butoxide were charged into the reactor. While stirring, 1 ml of a xylene solution containing 0.7 mg of palladium acetate and 2.35 mg of tricyclehexylphosphine was added. Thereafter, the reactor was heated to 140 ° C. and continued to be heated at that temperature for 2 to 3 hours to be reacted. After completion of the reaction, cool, 100 ml of toluene, 50 ml of water
Was added to separate the layers. The organic layer was washed 3 times with 50 ml / time of water, dried by contacting with magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was dissolved in a mixed solution of toluene / hexane (v / v = 1: 1) by heat, and then passed through column chromatography (silica gel 300 g, developing solvent: toluene / hexane = 1/1). Exemplified compound CT-1 was obtained (9.20 g, 21.3 mmol, yield 87%). The nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) of this compound is shown in FIG.

(Production Example 2: Production of Exemplified Compound CT-8)
Under a nitrogen atmosphere, 13.47 g (39.6 mmol) of (formylmethyl) triphenylphosphonium chloride (reagent B) and 6.38 g (36 mmol) of the aldehyde derivative (A) were dissolved in DMF, and 28% sodium methoxide in methanol 8.33. Sinamylaldehyde derivative (D) is synthesized by slowly adding g (43.2 mmol) and reacting. It was mixed with Wordsworth (reagent C) 11.06g (36mmol),
4.85 g (43.2 mmol) of potassium tert-butoxide was slowly added (cooled as necessary) and stirred for an additional hour. This solution was dropped into 500 ml of a methanol / ice water (v / v = 8: 2) mixed solution and crystallized. The obtained crystals were dried at 70 ° C. under reduced pressure to obtain 10 g (28.1 mmol, yield 78%) of butadiene precursor (E) as yellow crystals.

In a nitrogen atmosphere, a reactor was charged with 5.34 g (15 mmo) of butadiene precursor (E), 3.26 g (16.5 mmol) of diarylamine derivative (F), 70 ml of xylene, and 1.73 g (18 mmol) of sodium tert-butoxide. Then, 1 ml of a xylene solution containing 0.7 mg of palladium acetate and 2.35 mg of tricyclehexylphosphine was added. Thereafter, the reactor was heated to 140 ° C. and continued to be heated at that temperature for 2 to 3 hours to be reacted. After completion of the reaction, the reaction mixture was cooled, and 100 ml of toluene and 50 ml of water were added for liquid separation. The organic layer was washed 3 times with 50 ml / time of water, dried by contacting with magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was dissolved in a mixed solution of toluene / hexane (v / v = 1: 1) with heat, and column chromatography (silica gel 300 g, developing solvent: toluene / hexane = 1/1).
) To give the above exemplified compound CT-8 (4.92 g, 10.4 mmol, yield 69.4%). The nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) of this compound is shown in FIG.

(Production Example 3: Production of Exemplified Compound CT-9)
Under nitrogen atmosphere, butadiene precursor (E) 5.10g (14.3mmo) and diarylamine derivative (F
) 3.36 g (15.7 mmol), xylene 70 ml, sodium tert-butoxide 1.65 g (17.2 mmol) were charged into a reactor, and 1 ml of xylene solution containing 0.7 mg palladium acetate and 2.35 mg tricyclehexylphosphine with stirring. Was added. Thereafter, the reactor was heated to 140 ° C. and continued to be heated at that temperature for 2 to 3 hours to be reacted. After completion of the reaction, cool, 100 ml of toluene, 50 ml of water
Was added to separate the layers. The organic layer was washed 3 times with 50 ml / time of water, dried by contacting with magnesium sulfate, and concentrated under reduced pressure. The obtained crude product was dissolved in a mixed solution of toluene / hexane (v / v = 1: 1) by heat, and then passed through column chromatography (silica gel 300 g, developing solvent: toluene / hexane = 1/1). Exemplified compound CT-9 was obtained (4.99 g, 10.2 mmol, yield 71.4%). The nuclear magnetic resonance spectrum (300 MHz, Varian Gemini-2000 NMR spectrometer) of this compound is shown in FIG.

<Production of electrophotographic photoreceptor>
(Example 1: Electrophotographic photoreceptor A1)
Using a conductive support in which an aluminum vapor deposition 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 on the aluminum vapor deposition 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 prepared by the following method. 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 mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide are flowed at high speed Type mixing kneader (Co., Ltd.)
Hydrophobized titanium oxide by dispersing it in a methanol / 1-propanol ball mill and dispersing it in a methanol / 1-propanol ball mill. A dispersion slurry of The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (F)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula ( G)] / hexamethylenediamine [compound represented by the following formula (H)] / decamethylene dicarboxylic acid [compound represented by the following formula (I)] / octadecamethylene dicarboxylic acid [following formula The compound represented by (J)] has a composition molar ratio of 60% / 15% / 5% / 15% / 5% and is agitated and mixed with pellets of copolymerized polyamide to dissolve the polyamide pellets. Then, by carrying out ultrasonic dispersion treatment, the mass ratio of methanol / 1-propanol / toluene is 7/1/2 and the hydrophobically treated titanium oxide / copolymerized polyamide is contained at a mass ratio of 3/1. Solid content concentration A 18.0% undercoat layer dispersion was obtained.

Next, 10 parts of oxytitanium phthalocyanine having a powder X-ray diffraction spectrum shown in FIG. In addition to 150 parts of 2-dimethoxyethane, pulverization and dispersion treatment was performed with a sand grind mill to prepare a pigment dispersion. 160 parts by mass of the pigment dispersion thus obtained, 100 parts by mass of a 5% 1,2-dimethoxyethane solution of polyvinyl butyral (trade name # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.), and an appropriate amount of 1,2-dimethoxy Ethane was mixed to finally produce a dispersion having a solid concentration of 4.0%.
This dispersion was applied on the undercoat layer with a wire bar so that the film thickness after drying was 0.4 μm, and then dried to form a charge generation layer. Next, 50 parts by mass of the charge transport material CT-1 obtained in Production Example 1, 100 parts by mass of the following polycarbonate resin (A), 0.05 parts by mass of silicone oil as a leveling agent, a mixed solvent of tetrahydrofuran and toluene (tetrahydrofuran 80 wt%, toluene 20 wt%) was mixed with 640 parts to prepare a charge transport layer forming coating solution. This liquid is applied on the above-described charge generation layer using an applicator so that the film thickness after drying is 25 μm, and dried at 125 ° C. for 20 minutes to form a charge transport layer, whereby Photosensitive Sheet A
1 was produced. The viscosity average molecular weight of the polycarbonate resin (A) was 30,000.

The measuring method of the viscosity average molecular weight of the used binder resin is as follows. Dissolve the resin in dichloromethane to prepare a solution with a concentration C of 6.00 g / L. The flow time t of the sample solution is measured in a constant temperature water bath set to 20.0 ° C. using an Ubbelohde capillary viscometer with a flow time t ₀ of the solvent (dichloromethane) of 136.16 seconds. The viscosity average molecular weight Mv is calculated according to the following formula.

a = 0.438 × η _sp +1 η _sp = t / t ₀ −1
b = 100 × η _sp / C C = 6.00 (g / L)
η = b / a
Mv = 3207 × η ^1.205
(Example 2: electrophotographic photoreceptor A2)
An electrophotographic photoreceptor A2 as an example was obtained in the same manner as in Example 1 except that CT-8 was used as the 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-9 was used as a 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 charge transport material U exemplified in Patent Document 1 was used alone instead of the exemplified compound CT-1.

(Comparative Example 2: Electrophotographic photoreceptor P2)
An electrophotographic photoreceptor P1 as a comparative example was obtained in the same manner as in Example 1 except that the charge transport material V exemplified in Patent Document 2 was used alone in place of the exemplified compound CT-1.

(Comparative Example 3: Electrophotographic photoreceptor P3)
An electrophotographic photoreceptor P1 as a comparative example was obtained in the same manner as in Example 1 except that the charge transport material W exemplified in Patent Document 1 was used alone in place of the exemplified compound CT-1.

(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 X was used alone, instead of the exemplified compound CT-1. did. Attempts were made to measure the electrical characteristics of this photoreceptor, but no optical attenuation was observed, and the characteristics could not be measured.

The composition of the charge transport materials in the above Examples and Comparative Examples is summarized in Table-2.
(Example 4: electrophotographic photoreceptor B1)
100 parts by mass of polyarylate resin (B) having the following repeating structure (viscosity average molecular weight 43,000), 80 parts by mass of CT-1 obtained in Production Example 1 as a charge transport material, and represented by the following formula as an antioxidant 8 parts by weight of the compound (AOX1) and 0.05 parts by weight of silicone oil as a leveling agent are dissolved in 640 parts by weight of a mixed solvent of THF / toluene (8/2 (weight ratio)) to obtain a coating solution for forming a charge transport layer. A photoreceptor sheet B1 was prepared by the same production method as in Example 1.

(Examples 5 to 6: electrophotographic photoreceptors B2 and B3)
The electrophotographic photoreceptors B2 and B3 for Example 5 and Example 6 were used in the same manner as Example 4 except that CT-8 and CT-9 were used as charge transport materials, respectively, instead of the exemplified compound CT-1. Got. The composition of the charge transport material is summarized in Table-3.
(Comparative Example 5: electrophotographic photoreceptor P5)
An electrophotographic photosensitive member P5 as a comparative example was obtained in the same manner as in Example 4 except that the charge transport material U exemplified in Patent Document 1 was used alone instead of the exemplified compound CT-1. Many crystals were deposited after coating. Attempts were made to measure the electrical characteristics of this photoreceptor, but no optical attenuation was observed, and the characteristics could not be measured.

(Comparative Example 6: electrophotographic photoreceptor P6)
An electrophotographic photoreceptor P6 as a comparative example was obtained in the same manner as in Example 4 except that the charge transport material V exemplified in Patent Document 2 was used alone instead of the exemplified compound CT-1. Many crystals were deposited after coating. Attempts were made to measure the electrical characteristics of this photoreceptor, but no optical attenuation was observed, and the characteristics could not be measured.

(Comparative Example 7: electrophotographic photoreceptor P7)
An electrophotographic photoreceptor P7 as a comparative example was obtained in the same manner as in Example 4 except that the charge transport material W exemplified in Patent Document 2 was used alone in place of the exemplified compound CT-1.
(Comparative Example 8: electrophotographic photosensitive member P8)
An electrophotographic photosensitive member P8 as a comparative example was obtained in the same manner as in Example 4 except that the charge transport material X used in Comparative Example 4 was used alone instead of the exemplified compound CT-1. Many crystals were deposited after coating. Attempts were made to measure the electrical characteristics of this photoreceptor, but no optical attenuation was observed, and the characteristics could not be measured.
The compositions of the charge transport materials in Examples 4 to 6 and Comparative Examples 5 to 8 are summarized in Table 3.
[Characteristic evaluation]
The following electrical property tests were conducted on the produced electrophotographic photoreceptors A1 to A3, B1 to B3, and P1 to P8.

<Electrical characteristics test>
An electrophotographic characteristic evaluation apparatus manufactured according to the electrophotographic society measurement standard (basic and applied electrophotographic technology, edited by the Electrophotographic Society, Corona, pages 404 to 405) is used, and the photoreceptor sheet has an outer diameter of 80 mm. After the aluminum drum and the aluminum substrate of the photosensitive sheet are connected to each other, the drum is rotated at a constant rotational speed of 60 rpm to charge, expose, measure potential, and remove static electricity. An electrical property evaluation test by cycle was performed. At that time, the photosensitive member was charged so that the initial surface potential was − (minus, the same applies hereinafter) to 700 V, and the light from the halogen lamp was converted to monochromatic light of 780 nm with an interference filter and exposed at 1.0 μJ / cm ² . The post-exposure surface potential after 100 milliseconds (hereinafter sometimes referred to as Vl) was measured. In measuring Vl, the time required from the exposure to the potential measurement was set to 100 ms, which was a fast response condition. Further, the photoreceptor surface potential is -700 V to -350.
The half exposure energy E1 / 2 (μJ / cm2) required to reach V was determined. The measurement environment was a temperature of 25 ° C. and a relative humidity of 50%.
The evaluation results of the electrophotographic photoreceptors A1 to A3, B1 to B3, and P1 to P8 are shown in Tables 2 to 3.

  As shown in Tables 2 to 3, the electrophotographic photosensitive member using the known butadiene-based charge transport materials U, W, and X alone has the electrical characteristics of the novel butadiene compound of the present invention regardless of the binder resin. However, the compatibility with the binder resin was poor, and crystals were deposited after coating, so that light attenuation was hardly observed, and measurement of characteristics was not achieved. In contrast, the photoreceptor using the butadiene-based charge transport material of the present invention represented by the general formula [1] or [2] has good compatibility with the binder resin and exhibits excellent electrical characteristics. Recognize.

On the other hand, the electrophotographic photoreceptor using the known butadiene-based charge transport material V alone is compatible with the known polycarbonate resin as long as it is used in a low number of parts, and the electric characteristics are the same as those of the novel butadiene compound CT-1 of the present invention. It can also be seen that it does not fade (Example 1, Comparative Example 2). However, as a measure for high printing durability of electrophotographic photoreceptors, high printing resins such as polyarylate are generally used, and the use of low copies can satisfy the required performance in terms of electrical characteristics. It is unrealistic. When used in a high number of parts, the compatibility with a binder resin such as polyarylate was poor, and crystals were deposited after coating, so even light attenuation was not observed, and the measurement of properties was not achieved (Comparative Example 6).

<Image formation test>
(Examples 7-12, Comparative Examples 9-16)
The coating solution for forming the undercoat layer described in Example 1 and the following coating for forming the charge generation layer are formed on an aluminum cylinder having a mirror-finished outer diameter of 30 mm, a length of 260.5 mm, and a wall thickness of 0.75 mm. The coating solution for forming the charge transport layer used in the above-mentioned examples and comparative examples was sequentially applied by a dip coating method, and the film thickness after drying was 1.3 μm, 0.4 μm, and 25 μm, respectively. An undercoat layer, a charge generation layer, and a charge transport layer were formed to obtain photosensitive drums A7 to A9 and B7 to 9 as examples, and photosensitive drums P9 to P16 as comparative examples.

The charge generation layer forming coating solution was prepared as follows. As a charge generation material, 20 parts of oxytitanium phthalocyanine and 280 parts of 1,2-dimethoxyethane showing the X-ray diffraction spectrum by CuKα characteristic X-ray in FIG. 2 are mixed, and pulverized and dispersed in a sand grind mill for 1 hour. Processing was performed. Subsequently, 10 parts of polyvinyl butyral (trade name “Denka Butyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-methyl. A binder liquid obtained by dissolving in 85 parts of 2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution Y for forming a charge generation layer.

  As a charge generation material, 20 parts of oxytitanium phthalocyanine showing X-ray diffraction spectrum by CuKα characteristic X-ray in FIG. 3 and 280 parts of 1,2-dimethoxyethane are mixed and pulverized in a sand grind mill for 4 hours for atomization dispersion Processing was performed. Subsequently, 10 parts of polyvinyl butyral (trade name “Denka Butyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to 255 parts of 1,2-dimethoxyethane and 4-methoxy-4-methyl. A binder solution obtained by dissolving in a mixed solution of 85 parts of -2-pentanone and 230 parts of 1,2-dimethoxyethane were mixed to prepare a coating solution Z for forming a charge generation layer.

The charge generating layer forming coating solution Y and the charge generating layer forming coating solution Z are mixed at a weight ratio of 8: 2, and the charge generating layer forming coating solution used in Examples 7-12 and Comparative Examples 9-16 is prepared. did.
Here, an image characteristic test was performed using the produced photosensitive drum and toner having an average circularity of 0.990.
The image characteristic test was performed using a color printer HP Color LaserJet 4700dn (cleaning blade, counter contact method) manufactured by Hewlett-Packard Company.

The produced photosensitive drum and toner were mounted on a cyan process cartridge, and this cartridge was mounted on a printer. 10,000 images were formed under an environment of a temperature of 25 ° C. and a humidity of 50%, and ghosts, fogging, density reduction, filming, and poor cleaning were evaluated.
In the image forming apparatus using the electrophotographic photosensitive member of Examples 7 to 12, before image formation and 10
Even after the 000-sheet image formation, a good image with no image deterioration such as ghost, fogging, density reduction, filming, and poor cleaning was obtained. In addition, no abnormal noise was generated during printing.

In the image forming apparatuses using the electrophotographic photoreceptors of Comparative Examples 9 to 16, image characteristics could not be evaluated because crystals were deposited on the surface of the photoreceptor, or various kinds of image deterioration or abnormal noise occurred during printing.
The above results are summarized in Table 4 together with the butadiene charge transport material and the binder resin.

As can be seen from the comparison between Examples 7 to 12 and Comparative Examples 9 to 16 in Table 4, in the image forming apparatus using the electrophotographic photosensitive member containing the butadiene-based charge transport material of the present invention, before image formation Even after the 10,000-sheet image formation, a good image having no image deterioration such as ghost, fog, density reduction, filming, and poor cleaning was obtained. In addition, no abnormal noise was generated during printing. On the other hand, in an image forming apparatus using an electrophotographic photosensitive member containing a known butadiene-based charge transport material, not only is evaluation impossible, but various image degradation occurs, and abnormal noise occurs during printing. It was also confirmed (Comparative Examples 11 and 15).

  While the present invention has been described in connection with embodiments that are presently the most practical and preferred, the present invention is not limited to the embodiments disclosed herein. The electrophotographic photosensitive member and the image forming apparatus accompanying such changes are also within the technical scope of the present invention, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Must be understood as encompassed by.

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 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 (4)

In an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer contains at least one butadiene compound having a structure represented by the following general formula [1] or [2]. An electrophotographic photosensitive member.

(In the above formula [1] or [2], Ar ^{1 to} Ar ⁴ are the substituent constants σp in Hammett's rule, respectively.
Represents an aryl group which may have an organic group having 1 to 4 carbon atoms of 0.20 or less, Y represents an alkyl group having 1 to 4 carbon atoms, and R represents an alkyl group having 2 to 4 carbon atoms . However, out of Ar ¹ and Ar ²
Alternatively, at least one of Ar ³ and Ar ⁴ is an aryl group having the above substituent. ) 2. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, image exposure means for forming an electrostatic latent image on the charged electrophotographic photosensitive member by image exposure, and the electrostatic latent image An electrophotographic apparatus comprising at least one means selected from a developing means for developing an image with toner, a transferring means for transferring the toner to a transfer member, and a cleaning means for collecting the toner adhering to the electrophotographic photosensitive member. cartridge. 2. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, exposure means for forming an electrostatic latent image by exposure to the charged electrophotographic photosensitive member, and the electrostatic latent image An image forming apparatus comprising: a developing unit that develops toner with toner; a transfer unit that transfers the toner to a transfer target; and a fixing unit that fixes the toner transferred to the transfer target. A butadiene-based compound having a structure represented by the following general formula [1].

(In the formula [1], Ar ^{1 to} Ar ² each represents an aryl group which may have an organic group having 1 to 4 carbon atoms having a substituent constant σp in the Hammett rule of 0.20 or less, and Y is An alkyl group having 1 to 4 carbon atoms, wherein at least one of Ar ¹ and Ar ² is an aryl group having the substituent.

Images