JPH11174707A - Organic semiconductor film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an org. semiconductor film which does not cause leaching and dissolution at the time of forming other layer by coating when a laminated structure is formed and has high electron transferring ability and controlled humidity dependency of semiconductivity by combining an electron transferring pigment with a specified silane coupling agent. SOLUTION: The org. semiconductor film contains an electron transferring pigment, a bonding resin and a silane coupling agent having an amine structure preferably in combination with a silane coupling agent represented by the formula Rx R'y Si(OR")2 , wherein R, R' and R" are each H, 1-6C satd. or unsatd. hydrocarbon, phenyl or benzyl, (x) and (y) are each an integer of 0-2 and x+y=2. The electron transferring material is preferably selected from among a polycyclic quinone pigment, a perylene pigment and an azo pigment. The polycyclic quinone pigment is preferably brominated anthanthrone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic semiconductor film having an electron transporting property, and more particularly, to an electron transporting organic semiconductor film suitable for an undercoat layer of an electrophotographic photosensitive member formed by applying a coating solution of an organic compound. The present invention relates to an organic semiconductor film, an electrophotographic photoreceptor formed using the same, and an electrophotographic apparatus provided with the photoreceptor.

[0002]

2. Description of the Related Art In general, an organic semiconductor using an organic material can form a film by applying a solution containing the organic material and drying the solution. Therefore, it is widely used for a photoreceptor used in an electrophotographic image forming apparatus, a light emitting device using electroluminescence, and the like. For example, in an electrophotographic photoreceptor, hole transport formed from a coating liquid prepared by making an organic resin such as triphenylamine, hydrazone, stilbene or a derivative thereof compatible with an insulating resin such as polycarbonate. A transparent film is used as a layered type charge transport layer. Also,
Insulating resin such as polycarbonate, fluorenone, dicyanoquinodimethane, electron transporting film formed from a coating solution prepared by compatibilizing an organic low molecular compound such as diphenoquinone or a derivative thereof can also be used. Are known.

However, the fact that each layer constituting the photoreceptor can be formed by applying and drying a coating solution for forming each layer is that after forming one layer, another layer is formed on the formed layer. Layers are laminated, and when applying a coating solution of another forming layer, the lower film previously formed by the coating solution dissolves or swells and disturbs the upper layer. Inconvenience may occur.

In addition, in the case of a laminated photoreceptor, when a specific organic compound is used as a charge generation material, there is a problem that the chargeability is lowered and the stability upon repeated use is lowered. If there is a defect on the surface of the support, for example, a crystalline substance or the like found in an aluminum alloy, a non-uniform defect occurs in the charge generation layer, and black spots or white spots may occur on an image. Further, in an electrophotographic apparatus in which a charging member is arranged so as to be in contact with a photoreceptor, when partial insulation breakdown occurs, not only defects such as black spots and white spots are generated on an image, but also insulation When the charging member is in contact with the electrophotographic photoreceptor at the time of the destruction, the charging potential is remarkably reduced, and streak-like or planar image defects occur.

As means for solving these problems, an undercoat layer is generally provided between the conductive support and the charge generation layer. As a material for forming the undercoat layer, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral,
Thermoplastic resins such as polyvinyl methyl ether, polyamide, polyester resin, phenoxy resin, casein, gelatin, and nitrocellulose, and thermosetting resins such as polyimide, polyethylene imine, epoxy resin, melamine resin, and phenol resin are known. However, these resin materials are basically insulating materials, and the charge is transported by the moisture contained in the undercoat layer. And the like, and there is a problem that the charged potential is lowered in a high humidity environment.

Further, recently, electrophotographic apparatuses using coherent light sources, such as laser printers, have become widespread. In order to prevent interference fringes generated on an image with the electrophotographic apparatus, a conductive material of an electrophotographic photosensitive member has been used. Surface treatment for providing fine irregularities on a conductive substrate has been performed. In such a case, the undercoat layer is required to be able to sufficiently conceal the irregularities provided on the conductive substrate. Therefore, the undercoat layer is formed to have a relatively large layer thickness, and an insulating material is used therein. Has been
It becomes difficult to sufficiently exhibit the performance as the undercoat layer.

In order to improve the performance by making the undercoating layer contain an electron-accepting substance to facilitate the passage of electrons, Japanese Patent Publication No. 61-35551 and Japanese Patent Application Laid-Open No.
No. 160147 discloses this. It is also known to provide a precoat layer containing an N-type dye or pigment in addition to the undercoat layer (Japanese Patent Application Laid-Open No. 58-209751). (Japanese Patent Application Laid-Open No. 63-210848) or containing an organic metal compound reactive with an electron-transfer pigment (Japanese Patent Application Laid-Open No. 8-146439).

[0008]

However, when an electron-accepting substance is contained in the undercoat layer, since the electron-accepting substance is soluble in a solvent, it is difficult to form a photosensitive layer on the undercoat layer by coating. In particular, when a coating film is formed by a dip coating method, there is a problem that an electron accepting substance is eluted into a photosensitive layer or a coating solution. When the pigment is contained in the undercoat layer, the pigment itself is hardly soluble or insoluble in a solvent and thus does not elute into the photosensitive layer. However, the undercoat layer is formed by applying a coating solution in which the pigment is dispersed in a resin. When an upper photosensitive layer forming solution containing a solvent in which the resin used for the undercoat layer is soluble is applied, the resin dissolves to cause coating defects, and the undercoat layer has a sufficient function as the undercoat layer. Cannot be achieved. Further, in the undercoat layer described in Japanese Patent Application Laid-Open No. 8-146636, although the dissolution due to the application of the upper layer can be avoided, a large humidity dependency appears in the semiconductor properties,
In particular, there is a disadvantage that the semiconductor property is reduced under a high humidity condition, and the movement of the holes is increased.

The present invention has been made in view of the above-mentioned circumstances in the prior art. That is, the object of the present invention is not to be eluted and dissolved at the time of forming another layer when forming a laminated structure, and also has a high electron transportability,
An object of the present invention is to provide an organic semiconductor film in which the humidity dependence of semiconductor properties is suppressed. Another object of the present invention is to provide an electrophotographic photoreceptor having excellent characteristics by providing the above organic semiconductor film as an undercoat layer. Another object of the present invention is to provide an electrophotographic photoreceptor in which dielectric breakdown is unlikely to occur even in a contact charging method by forming a thickened high withstand voltage undercoat layer without impairing electrophotographic characteristics. is there. Another object of the present invention is to provide an electrophotographic apparatus using the above electrophotographic photosensitive member in a contact charging system.

[0010]

The present inventors have conducted intensive studies on organic semiconductor films using various organic materials. As a result, by combining an electron transporting pigment with a specific silane coupling agent, the electrical characteristics of the organic semiconductor film were improved. It has been found that an organic semiconductor film having a good electrophotographic property can be obtained, and that an electrophotographic photoreceptor having excellent electrophotographic characteristics can be produced by forming the organic semiconductor film as an undercoat layer, thereby completing the present invention.

That is, the first organic semiconductor film of the present invention is characterized by containing an electron transporting pigment, a binder resin and a silane coupling agent having an amine structure, and is further represented by the following formula (1). It is preferable that the silane coupling agent is contained in combination. RxR'ySi (OR ") ₂ (1) (wherein, R, R 'and R" are each independently a hydrogen atom, a saturated or unsaturated hydrocarbon having 1 to 6 carbon atoms, phenyl or benzyl, A group selected from: x
And y are each an integer of 0 to 2, and x + y =
2. )

The second organic semiconductor film of the present invention comprises an electron transporting pigment, an organic metal compound reactive with a binder resin, and a silane coupling agent represented by the following formula (1). I do. RxR'ySi (OR ") ₂ (1) (wherein, R, R ', R", x and y have the same meanings as above.) As an electron transporting material used in the organic semiconductor film of the present invention, Is preferably at least one selected from polycyclic quinone pigments, perylene pigments and azo pigments, and the polycyclic quinone pigment is preferably a brominated anthantrone.

The electrophotographic photoreceptor of the present invention is a negatively charged electrophotographic photoreceptor having an undercoat layer and a photosensitive layer on a conductive support, wherein the undercoat layer is formed of the above organic semiconductor film. It is characterized by being formed by. Further, an electrophotographic apparatus according to the present invention includes an electrophotographic photosensitive member and a contact charging member arranged to be in contact with the photosensitive member, and the photosensitive member is the above-described electrophotographic photosensitive member. And

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The electron transporting pigment used in the organic semiconductor film of the present invention is selected from those having good electron mobility, such as perylene pigment, bisimidazole perylene pigment, polycyclic quinone pigment, indigo pigment, quinacridone pigment, and the like. Organic pigments, organic pigments such as bisazo pigments or phthalocyanine pigments having an electron-withdrawing substituent such as a cyano group, nitro group, nitroso group, and halogen atom, and inorganic pigments such as zinc oxide and titanium oxide are exemplified. Among these, it is preferable to use perylene pigments, bisimidazole perylene pigments, and polycyclic quinone pigments, particularly brominated anthantrone pigments, which have high electron mobility. Specific chemical structural formulas of typical electron transporting materials used in the present invention are shown below.

[0015]

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[0016]

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[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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The electron transporting performance of the pigment used for the organic semiconductor film in the present invention is determined by the Delayed Colle.
It can be measured by the ction field method. As a specific measuring method, a thin injection blocking layer was provided on Nesa glass, a pigment dispersed in a resin was applied thereon to a thickness of several μm, and a gold electrode was deposited thereon. A capacitor-like structure is used as a measurement sample, for example,
While applying a voltage with the Nesa glass side as the negative electrode and the metal side as the positive electrode, a laser pulse is irradiated from the Nesa glass side to generate charges on the surface of the pigment dispersion film, and the photoelectric flow rate due to the negative charges is measured. Conversely, the photoelectric flow rate due to positive charges is measured while applying a voltage. At that time, those having a property that a photocurrent flows by at least a negative charge (electron) are preferably used as the electron-moving pigment.

In the present invention, the above-mentioned electron transporting pigment is used by dispersing it in a coating solution obtained by dissolving a binder resin in a solvent. As the binder resin, known resins conventionally used for a charge generation layer in which a charge generation material is dispersed, for example, polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid), polycarbonate resin, Insulating resins such as phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic resin, polyacrylamide, polyamide resin, polyvinyl pyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone In particular, polyvinyl butyral having high ability to stably disperse the electron transporting pigment is preferable.

A silane coupling agent is used for the organic semiconductor film of the present invention, and a silane coupling agent having an amine structure is used for the first organic semiconductor film.
As the “silane coupling agent having an amine structure” used in the present invention, specifically, N- (3-acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, 3- (N-allylamino ) Propyltrimethoxysilane, 4-aminobutyltriethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (6-aminohexyl) Aminopropyltrimethoxysilane, 3- (m-
Aminophenoxy) propyltrimethoxysilane, aminophenyltrimethoxysilane, 3- (1-aminopropoxy) -3,3-dimethyl-1-propenyltrimethoxysilane, 3-aminopropyltriethoxysilane,
3-aminopropyltrimethoxysilane, 3-aminopropyl-tris (methoxyethoxyethoxy) silane,
Bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, bis (trimethoxysilylpropyl) amine, bis [3- (trimethoxysilyl) propyl] ethylenediamine, (N, N-dimethylaminopropyl) trimethoxysilane N- (3-methacryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, N-methylaminopropyltrimethoxysilane, N-phenylaminopropyltrimethoxysilane, N- (2-aminoethyl) -3 -Aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-dimethylaminopropyldiethoxymethylsilane, 3-aminopropyldiisopropylethoxysilane, 3-aminopropyldimethyldiethoxysilane and the like. .

In the first organic semiconductor film of the present invention, the silane coupling agent used in combination with the silane coupling agent having the amine structure or the silane coupling agent used in the second organic semiconductor film of the present invention. The ring agent is represented by the following formula (1). RxR'ySi (OR ") ₂ (1) In the above formula, R, R 'and R" are each a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, It is a group selected from saturated hydrocarbons having 1 to 6 carbon atoms such as t-butyl and propyl, unsaturated hydrocarbons having 1 to 6 carbon atoms having a vinyl or acetyl bond, phenyl or benzyl. X and y are
Each is 0, 1 or 2, but the sum of x and y is 2.

Specific examples of the silane coupling agent represented by the formula (1) used in the present invention include diethoxysilane, dimethoxymethylsilane, diethoxymethylsilane, diethoxymethylvinylsilane, and diethoxydivinylsilane. Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dimethoxymethylphenylsilane, diethoxymethylphenylsilane, dimethoxydiphenylsilane, diethoxydiphenylsilane, diisobutyldimethoxysilane, diisopropyldimethoxysilane and the like. .

The “reactive organometallic compound” used in the second organic semiconductor film in the present invention includes a zirconium chelate compound, a zirconium alkoxide compound,
Organic zirconium compounds such as zirconium coupling agents, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds such as titanate coupling agents,
Aluminum chelate compounds, in addition to organic aluminum compounds such as aluminum coupling agents, antimony alkoxide compounds, germanium alkoxide compounds,
Examples include indium alkoxide compounds, indium chelate compounds, manganese alkoxide compounds, manganese chelate compounds, tin alkoxide compounds, tin chelate compounds, aluminum silicon alkoxide compounds, aluminum titanium alkoxide compounds, and aluminum zirconium alkoxide compounds. Among these, organic zirconium compounds, organic titanyl compounds,
Organoaluminum compounds are preferred, and zirconium alkoxide compounds, zirconium chelate compounds, titanium alkoxide compounds and titanium chelate compounds exhibiting good properties are particularly preferred.

The organic semiconductor film of the present invention is preferably formed by preparing and applying a coating solution containing the above components. The coating liquid is prepared by dispersing a charge transporting pigment in a solution obtained by dissolving a binder resin in an organic solvent using a conventional method such as a ball mill, a roll mill, a sand mill, an attritor, and an ultrasonic method. As the solvent, any solvent can be used as long as it does not dissolve the binder resin or the silane coupling agent and does not cause gelation or aggregation even when the charge transporting pigment is dispersed. , Ethanol, propanol, butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve,
Commonly used organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene are used alone or in combination of two or more. .

In forming the organic semiconductor film of the present invention, the weight ratio of the electron transporting pigment to the binder resin is from 1: 1 to 39: 1.
, But is preferably in the range of 2: 1 to 19: 1. When the addition amount of the electron transporting pigment is smaller than this, the effect of transferring electrons is reduced, while when the addition amount is excessive, the life of the coating liquid is shortened, or a problem may occur in the coating property due to aggregation and aggregation. .

The amount of the silane coupling agent having an amine structure used for forming the first organic semiconductor film is set in the range of 0.1 to 5 times the weight of the binder resin, but is preferably 0.1 to 5 times. The range is 2 to 2 times. If the amount of the silane coupling agent having an amine structure is too small, the coating property of the upper photosensitive layer is adversely affected, while if too large, the electrical characteristics of the photoreceptor are deteriorated under high temperature and high humidity. When an organic semiconductor film is formed by using a silane coupling agent having an amine structure and a silane coupling agent represented by the above formula (1) in combination, the silane coupling agent represented by the formula (1) is used. The amount of the agent is set in the range of 1 to 10 times the weight of the silane coupling agent having an amine structure. By using the silane coupling agent represented by the formula (1) in combination with the first organic semiconductor film, the silane coupling agent having an amine structure can be obtained without deteriorating the electrical characteristics of the photoconductor under high temperature and high humidity. As a result, it is possible to easily achieve both the coating property of the upper layer and the good electrical characteristics of the photoreceptor.

In the formation of the second organic semiconductor film, the weight ratio of the silane coupling agent to the binder resin is set in the range of 0.1 to 10 times the binder resin, but is preferably 0.1 to 10 times.
The range is 5 to 5 times. If the addition amount of the silane coupling agent is less than this, it becomes easy to dissolve in the solvent,
If it is excessive, the electron transportability becomes insufficient.

The addition amount of the reactive organometallic compound used for forming the second organic semiconductor film is determined by the above formula (1)
Is set in the range of 0.01 to 5 times the amount of the silane coupling agent represented by the formula, but preferably in the range of 0.1 to 2 times the amount. If the added amount is too large, the semiconductor properties are easily lost at high humidity, while if it is too small, the film tends to be easily eroded by the solvent.

In the preparation of the organic semiconductor film, the silane coupling agent or the reactive organometallic compound may be added to the coating solution for forming the organic semiconductor film either before or after dispersing the electron transporting pigment. In addition, the silane coupling agent may be added to the coating solution after performing a partial hydrolysis reaction or a partial dehydration condensation reaction using equimolar or less water for the hydrolyzable reactive group. When the reactive organometallic compound easily precipitates, it is desirable to simultaneously hydrolyze the silane coupling agent and the reactive organometallic compound.

The organic semiconductor film of the present invention obtained as described above has good electron transporting properties, has semiconductor-dependent environment resistance, and can easily form a pressure-resistant film having a laminated structure by a coating method. Accordingly, it can be used in an undercoat layer of an electrophotographic photosensitive member, an optical semiconductor layer of a solar cell, an EL element, and the like.

Hereinafter, the method for producing an organic semiconductor film of the present invention will be further described with reference to an example of forming an undercoat layer of an electrophotographic photosensitive member according to the present invention. The electrophotographic photoreceptor of the present invention is of a negative charge type in which a photosensitive layer is formed on a conductive support, and the above-described electron conductive organic semiconductor film is provided between the conductive support and the photosensitive layer. Is provided as an undercoat layer, and the photosensitive layer may have a single-layer structure or a laminated structure.

FIG. 1 is a schematic sectional view showing a typical laminated electrophotographic photosensitive member according to the present invention, wherein 1 is a conductive support, 2 is a charge generation layer, 3 is a charge transport layer, and 4 is 3 shows an undercoat layer. Hereinafter, a specific description will be given by taking the electrophotographic photosensitive member having this laminated structure as an example. In the present invention, as the conductive support, a metal drum or sheet of aluminum, copper, stainless steel or the like, a laminate of a metal foil such as aluminum on a plastic film or paper, and further, a metal or resin drum A resin layer in which conductive particles are dispersed is applied. The surface of the metal drum may be subjected to a roughening treatment for preventing interference fringes.

The undercoat layer is formed by applying and drying the above-mentioned organic semiconductor film. The film thickness is usually in the range of 0.1 to 20 μm, preferably 0.5 to 10 μm
Is set in the range. As the coating method, a known coating method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method is used. The coating layer formed by coating is 110 to 200 ° C., preferably 135
5 minutes to 6 hours, preferably 7 to 180 ° C.
An undercoat layer is formed by air drying or still drying for minutes to 1.5 hours.

Next, a charge generation layer is formed on the undercoat layer. As the charge generation layer, a material in which a charge generation material is dispersed in an organic solvent in which a binder resin is dissolved, a conventionally known spray coating method, blade coating method,
It is formed by applying and drying by a spinner coating method, a bead coating method, a bar coating method, or the like, or by directly forming a film of a charge generation material by a vacuum evaporation method or the like. As the charge generating material, for example, azo pigments such as chlorodiane blue, anthrone,
Use of quinone pigments such as pyrenequinone, quinocyanine pigments, perylene pigments, perinone pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments such as vanadyl phthalocyanine, titanyl phthalocyanine, and galium phthalocyanine, azulhenium salts, squarium pigments, quinacridone pigments, and the like. Can be. Examples of the binder resin include polyvinyl butyral, polyarylate (polycondensate of bisphenol A and phthalic acid), polycarbonate resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, acrylic resin, polyacrylamide, Insulating resins such as polyamide resin, polyvinyl pyridine, cellulosic resin, urethane resin, epoxy resin, casein, polyvinyl alcohol and polyvinyl pyrrolidone are used. The thickness of the charge generation layer is 0.0
It is arbitrarily set in the range of 1 to 5 μm, but is preferably in the range of 0.1 to 0.5 μm.

Next, a charge transport layer is formed on the obtained charge generation layer. The charge transport layer is obtained by dissolving a binder resin in an organic solvent and adding a solution in which a charge transport material is added thereto or a solution in which a polymerized charge transport material is dissolved in an organic solvent, by a spray coating method, a blade coating method, It is formed by applying by a method such as a spinner coating method, a bead coating method, a bar coating method, and the like, followed by drying. Examples of the charge transport material include polycyclic aromatic compounds such as anthracene, pyrene, and phenanthrene; compounds having a nitrogen-containing heterocycle such as indole, carbazole, and imidazole; pyrazoline compounds; hydrazone compounds; triphenylmethane compounds; and triphenyl An amine compound, an enamine compound, a stilbene compound and the like are used. The binder resin may be any resin as long as it is a film-forming resin. For example, polyester, polysulfone, polycarbonate, polymethyl methacrylate, and the like are used. As the polymer charge transporting material, a pendant type such as polyvinyl carbazole, or a main chain type containing an arylamine in the main chain can be used. The thickness of the charge transport layer is arbitrarily set in the range of 5 to 40 μm, but is preferably in the range of 15 to 30 μm.

The electrophotographic photoreceptor of the present invention exhibits excellent characteristics not only in an electrophotographic apparatus using a conventional corona discharge type charging member but also in an electrophotographic apparatus using a contact charging type.

Next, the electrophotographic apparatus of the present invention will be described. FIG. 2 is a schematic configuration diagram of the electrophotographic apparatus of the present invention. Reference numeral 11 denotes a photoconductor, and a contact charging member 12 is provided so as to be in contact with the photoconductor. A voltage is supplied from a power supply 13 to the contact charging member. Exposure device 14, developing device 15,
A transfer device 16 and a cleaning device 17 are provided, respectively. The static eliminator 18 is provided as needed. Reference numeral 19 denotes a fixing device.

The contact charging member 12 of the electrophotographic apparatus employing the contact charging system is arranged so as to contact the surface of the photoreceptor, and applies a voltage from a power source to bring the surface of the photoreceptor to a predetermined potential. It has the function of uniformly charging the surface. Examples of the contact charging member include metals such as aluminum, iron, and copper, conductive polymer materials such as polyacetylene, polypyrrole, and polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, and styrene. -Elastomer materials such as butadiene rubber, carbon black,
It can be formed using a material in which conductive particles such as copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide are dispersed. Examples of the metal oxide include ZnO, Sn
O ₂ , TiO ₂ , In ₂ O ₃ , MoO ₃ or the like or a composite oxide thereof is used. In addition, an elastomer material containing perchlorate to impart electrical conductivity may be used, or a material having a coating layer on the surface may be used. As a material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinylpyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine, or the like may be used alone or in combination of two or more. Further, as the emulsion resin material, for example, an acrylic resin emulsion, a polyester resin emulsion, a polyurethane, and particularly an emulsion resin synthesized by soap-free emulsion polymerization is used. These resins may be further dispersed with conductive particles in order to adjust the resistivity, or may contain an antioxidant to prevent deterioration. Further, in order to improve the film forming property when forming the coating layer, the emulsion resin may contain a leveling agent or a surfactant.

The shape of the contact charging member may be any type such as a roller type, a blade type, a belt type, and a brush type. As the voltage applied to the contact charging member, a direct current or a combination of a direct current and an alternating current is used. As the exposure device, the developing device, the transfer device, and the cleaning device, any conventionally known devices can be used. Further, the electrophotographic apparatus of the present invention may be provided with a static eliminator as needed, and a conventionally known static eliminator is used.

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Example 1 After dissolving 2 parts by weight of a polyvinyl butyral resin (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.) in a mixed solvent of 60 parts by weight of n-butanol and 30 parts by weight of cyclohexanone, the compound is represented by the following structural formula (A). 8 parts by weight of dibromoanthanthrone (Monolith Red 2Y, manufactured by ICI) were mixed and dispersed together with glass beads for 1 hour using a paint shaker to obtain a dispersion of dibromoanthanthrone. To this dispersion was added 0.4 parts by weight of 3-aminopropyltriethoxysilane, and the mixture was stirred to prepare a coating liquid for forming an organic semiconductor film. 25 in this coating solution
A coating layer of an organic semiconductor is formed on the surface of the aluminum plate by a dip coating method of immersing an aluminum plate of × 35 × 0.5 mm, and dried at 170 ° C. for 30 minutes to form an organic semiconductor having a thickness of 2.5 μm. An undercoat layer consisting of a film was obtained.

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Next, 5 parts by weight of an X-type metal-free phthalocyanine, 5 parts by weight of a vinyl chloride-vinyl acetate copolymer (VMCH, manufactured by Union Carbide) and 200 parts by weight of n-butyl acetate were used together with glass beads using a sand mill. The dispersion liquid prepared by the dispersion treatment was dip-coated on the undercoat layer, and dried at 100 ° C. for 10 minutes to prepare a sample in which a 0.2 μm-thick charge generation layer was formed. . Regarding the electrical characteristics of the obtained sample, EP
A-8100 (manufactured by Kawaguchi Electric Co., Ltd.) was evaluated using a modified apparatus. First, the charger was adjusted to make the sample -100.
V was irradiated with light (5 μW / cm ² ) from a light source obtained by combining a xenon lamp with an interference filter, and a potential was measured three seconds after the irradiation to evaluate electron mobility. Next, the charger was adjusted to charge the sample to +100 V, and light (5 μW / cm ² ) from a light source obtained by combining a xenon lamp with an interference filter was used.
The potential after two seconds was measured to evaluate the hole mobility. These measurements are performed in a chamber where the temperature and humidity can be controlled separately, and by evaluating the results at high temperature and high humidity (28 ° C., 85%) and normal temperature and normal humidity (20 ° C., 40%), the semiconductor properties are evaluated. The stability was evaluated.

Example 2 In Example 1, 2 parts by weight of (N, N-dimethylaminopropyl) trimethoxysilane was used instead of 0.4 part by weight of 3-aminopropyltriethoxysilane used for forming the undercoat layer. A sample was prepared in the same manner as in Example 1 except that the parts were used, and the electrical characteristics were evaluated. Example 3 In Example 1, except that 2 parts by weight of 3-aminopropylmethyldiethoxysilane was used instead of 0.4 part by weight of 3-aminopropyltriethoxysilane used for forming the undercoat layer. A sample was prepared in the same manner as in Example 1, and its electrical characteristics were evaluated.

Example 4 In Example 1, 8 parts by weight of a benzimidazole pigment mixture represented by the following structural formula (B) was used instead of 8 parts by weight of dibromoanthanthrone used for forming the undercoat layer. Except for the above, a sample was prepared in the same manner as in Example 1, and its electrical characteristics were evaluated.

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Example 5 The procedure of Example 1 was repeated, except that the coating solution for forming the undercoat layer in Example 1 was replaced with a coating solution prepared by adding 1 part by weight of dimethoxydimethylsilane to the coating solution material for the formation. A sample was prepared in the same manner as in Example 1, and the electrical characteristics were evaluated. Example 6 A sample was prepared in the same manner as in Example 5, except that the amount of 3-aminopropyltriethoxysilane used was changed to 3 parts by weight to form an undercoat layer.
The electrical characteristics were evaluated.

Comparative Example 1 Except that 0.4 parts by weight of 3-aminopropyltriethoxysilane used in Example 1 was replaced by 5 parts by weight of acetylacetone zirconium butyrate (trade name: ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) Prepared a sample in the same manner as in Example 1, and evaluated its electrical characteristics. Comparative Example 2 A sample was prepared in the same manner as in Example 1 except that 0.4 parts by weight of methyltrimethoxysilane was used instead of 0.4 parts by weight of 3-aminopropyltriethoxysilane used in Example 1. It was fabricated and its electrical characteristics were evaluated.

Comparative Example 3 A sample was prepared in the same manner as in Example 5 except that 1 part by weight of dimethoxydimethylsilane used in Example 5 was replaced with 1 part by weight of tetraethoxysilane, and its electrical characteristics were evaluated. did. Comparative Example 4 A sample was prepared in the same manner as in Example 1 except that 3-aminopropyltriethoxysilane was not added, and the electrical characteristics were evaluated.

Comparative Example 5 A coating solution prepared by dissolving 7 parts by weight of an 8-nylon resin (Lacamide 5003, manufactured by Dainippon Ink and Chemicals) in a mixed solvent of 62 parts by weight of methanol and 31 parts by weight of butanol was applied by dip coating. A sample was prepared in the same manner as in Example 1 except that a film obtained by drying this at 150 ° C. for 30 minutes was used.
In H), neither positive nor negative can be charged,
The electrical characteristics could not be evaluated.

Table 1 shows the results obtained in Examples 1 to 6 and Comparative Examples 1 to 5.

[Table 1]

Example 7 An undercoating layer and a charge generation layer comprising the same organic semiconductor film as in Example 1 were sequentially formed on a surface-roughened aluminum pipe having a diameter of 40 mm and a length of 318 mm. A solution comprising 1 part by weight of a benzidine compound represented by the formula (C), 1 part by weight of a polycarbonate having a repeating structural unit represented by the following structural formula (D), and 6 parts by weight of monochlorobenzene is dip-coated on the charge generation layer. Then, this was dried at 135 ° C. for 1 hour to form a 20 μm-thick charge transport layer, thereby producing an electrophotographic photosensitive member.

[0054]

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The obtained electrophotographic photosensitive member was contact-charged with a laser printer (PR-1000, manufactured by NEC Corporation).
To form a copied image, and the image was evaluated. As the contact charging member, a member in which an elastic layer and a resin layer were provided on the outer periphery of a 18.8 stainless steel shaft having a diameter of 5 mm was used. That is, on the contact charging member, an elastic layer made of a polyether-based polyurethane rubber having conductivity by adding 0.5% by weight of lithium perchlorate is formed on the outer periphery of the shaft so as to have a diameter of 15 mm. An aqueous solution of a polyester-based polyurethane emulsion resin containing a leveling agent having a methylphenylsilicone content of 0.001% by weight is applied as a coating solution on the surface by dip coating, and dried at 120 ° C. for 20 minutes to form a coating layer having a thickness of 20 μm. The formed contact-type roll-type charging member was used. Also,
Image evaluation was performed at room temperature and normal humidity (20 ° C., 40% RH), high temperature and high humidity (28 ° C., 85% RH), and low temperature and low humidity (10 ° C., 15% RH).
% RH), no defects such as fog and black spots were observed under any environment.

Example 8 An electrophotographic photosensitive member was prepared in the same manner as in Example 7, except that the same organic semiconductor film as in Example 2 was used as the undercoat layer.
When the image evaluation was performed in the same manner, the fog, under any environmental conditions of normal temperature and normal humidity, high temperature and high humidity, and low temperature and low humidity,
No defects such as black spots were observed. Comparative Example 6 An electrophotographic photosensitive member was prepared and image evaluation was performed in the same manner as in Example 7, except that the same organic semiconductor film as in Comparative Example 2 was used as the undercoat layer. Under high humidity conditions, fogging occurs on the entire surface of the image,
Under low-temperature and low-humidity conditions, the image density was significantly reduced as the image formation was repeated. Comparative Example 7 In Example 7, an 8-nylon resin (lactamide 5
003, manufactured by Dainippon Ink and Chemicals, Inc.
Except that it was immersed in a coating solution dissolved in a mixed solvent of 2 parts by weight and 31 parts by weight of butanol, and dried at 150 ° C. for 30 minutes to obtain a 0.2 μm-thick undercoating layer, An electrophotographic photoreceptor was prepared in the same manner as in Example 7, and image evaluation was performed. As a result, black spots were generated on the entire surface of the image and black stripes were generated due to occurrence of discharge breakdown.

Example 9 A mixture of 60 parts by weight of n-butanol and 30 parts by weight of cyclohexanone was dissolved in 2 parts by weight of a polyvinyl butyral resin (Eslec BM-S, manufactured by Sekisui Chemical Co., Ltd.). The mixture was mixed with 8 parts by weight of dibromoanthanthrone (Monolight Red 2Y, manufactured by ICI) and dispersed with glass beads for 1 hour using a paint shaker to obtain a dispersion of dibromoanthanthrone. 1 part by weight of acetylacetone zirconium butyrate (trade name: ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.) and 1 part by weight of dimethoxydimethylsilane were added to the dispersion and stirred to prepare a coating liquid for forming a semiconductor film. A 25 × 35 × 0.5 mm aluminum plate is immersed in the coating solution by a dip coating method, and is applied to the surface of the aluminum plate, and dried at 170 ° C. for 30 minutes to form a film having a thickness of 2.5 μm.
Thus, an undercoat layer comprising an organic semiconductor film having a thickness of m was obtained.

[0058]

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Next, 5 parts by weight of an X-type metal-free phthalocyanine, 5 parts by weight of a vinyl chloride-vinyl acetate copolymer (VMCH, manufactured by Union Carbide) and 200 parts by weight of n-butyl acetate were used together with glass beads using a sand mill. The dispersion liquid prepared by the dispersion treatment was dip-coated on the undercoat layer, and dried at 100 ° C. for 10 minutes to prepare a sample in which a 0.2 μm-thick charge generation layer was formed. . Regarding the electrical characteristics of the obtained sample, EP
A-8100 (made by Kawaguchi Electric Co., Ltd.)
The evaluation was performed in exactly the same manner as in Example 1.

Example 10 The procedure of Example 9 was repeated, except that 1 part by weight of dimethoxydimethylsilane used in forming the undercoat layer was replaced by 2 parts by weight of dimethoxydiethylsilane. Samples were prepared and their electrical characteristics were evaluated. Example 11 A sample was prepared in the same manner as in Example 9 except that 1.5 parts by weight of dimethoxydiphenylsilane was used instead of 1 part by weight of dimethoxydimethylsilane used for forming the undercoat layer. Was fabricated and its electrical characteristics were evaluated.

Example 12 In Example 9, 8 parts by weight of a benzimidazole pigment mixture represented by the following structural formula (B) was used in place of 8 parts by weight of dibromoanthanthrone used for forming the undercoat layer. Except for the above, a sample was prepared in the same manner as in Example 9, and the electrical characteristics were evaluated.

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Example 13 1 part by weight of acetylacetone zirconium butyrate used in Example 9 was replaced with titanium butoxide (Orgatic T
(A-10, manufactured by Matsumoto Pharmaceutical Co., Ltd.) A sample was prepared in the same manner as in Example 9 except that an undercoat layer was formed instead of 0.2 part by weight, and the electrical characteristics were evaluated. Example 14 Except that 1 part by weight of acetylacetone zirconium butyrate used in Example 11 was replaced with 0.5 part by weight of titanium butoxide (Orgatics TA-10, manufactured by Matsumoto Pharmaceutical Co., Ltd.) to form an undercoat layer A sample was prepared in the same manner as in Example 11, and the electrical characteristics were evaluated.

Comparative Example 8 An undercoat layer was formed in the same manner as in Example 9 except that acetylacetone zirconium butyrate and dimethoxydimethylsilane were not added, and a charge generation layer was dip-coated thereon. I tried, but a good sample could not be obtained because the film of the undercoat layer was partially dissolved,
Therefore, its electrical characteristics could not be evaluated.

Comparative Example 9 An undercoat layer was formed in the same manner as in Example 9 except that 1 part by weight of dimethoxydimethylsilane used in Example 9 was replaced with 1 part by weight of methoxymethylsilane. An attempt was made to dip coat the generating layer, but a good sample could not be obtained due to partial dissolution of the undercoat layer film, and therefore its electrical properties could not be evaluated. Comparative Example 10 A sample was prepared in the same manner as in Example 9 except that 1 part by weight of acetylacetone zirconium butyrate used in Example 9 was changed to 5 parts by weight and an undercoat layer was formed without adding dimethoxydimethylsilane. Was fabricated and its electrical characteristics were evaluated.

Comparative Example 11 A coating solution obtained by dissolving 7 parts by weight of an 8-nylon resin (Lacamide 5003, manufactured by Dainippon Ink and Chemicals) in a mixed solvent of 62 parts by weight of methanol and 31 parts by weight of butanol was applied by dip coating. A sample was prepared in the same manner as in Example 1 except that a resin film having a thickness of 2.5 μm obtained by drying at 150 ° C. for 30 minutes was used.
(85% RH), it was not possible to charge both positive and negative, and electrical characteristics could not be evaluated.

Comparative Example 12 A sample was prepared in the same manner as in Example 9 except that 1 part by weight of dimethoxydimethylsilane used in Example 9 was replaced with 1 part by weight of tetraethoxysilane to form an undercoat layer. And its electrical characteristics were evaluated.

Comparative Example 13 Example 9 was repeated except that 1 part by weight of acetylacetone zirconium butyrate used in Example 9 was replaced with 10 parts by weight of titanium butoxide and an undercoat layer was formed without adding dimethoxydimethylsilane. A sample was prepared in the same manner as described above, and its electrical characteristics were evaluated.

Table 2 shows the results obtained in Examples 9 to 14 and Comparative Examples 8 to 13.

[Table 2]

Example 15 An undercoating layer and a charge generation layer comprising the same organic semiconductor film as in Example 9 were sequentially formed on a surface-roughened aluminum pipe having a diameter of 40 mm and a length of 318 mm. A solution comprising 1 part by weight of a benzidine compound represented by the formula (C), 1 part by weight of a polycarbonate having a repeating structural unit represented by the following structural formula (D), and 6 parts by weight of monochlorobenzene is dip-coated on the charge generation layer. Then, this was dried at 135 ° C. for 1 hour to form a 20 μm-thick charge transport layer, thereby producing an electrophotographic photosensitive member.

Embedded image

The obtained electrophotographic photosensitive member was contact-charged with a laser printer (PR-1000, manufactured by NEC Corporation).
To form a copied image, and the image was evaluated. As the charging member, the same contact-type roll-type charging member as used in Example 7 was used. The image evaluation was performed at normal temperature and normal humidity (20 ° C., 40% RH), high temperature and high humidity (28 ° C., 85%).
% RH) and low temperature and low humidity (10 ° C., 15% RH), no defects such as fog and black spots were observed in any environment.

Example 16 An electrophotographic photoreceptor was prepared and image evaluation was performed in the same manner as in Example 15 except that the same organic semiconductor film as in Example 10 was used as the undercoat layer. Defects such as fog and black spots were not observed under any environmental conditions of high temperature, high humidity and low temperature and low humidity.

Comparative Example 14 An electrophotographic photosensitive member was produced in the same manner as in Example 15 except that the resin film formed in Comparative Example 11 was used as an undercoat layer, and image evaluation was performed. As a result, fogging occurred on the entire surface of the image under high-temperature and high-humidity conditions, and under low-temperature and low-humidity, the image density was significantly reduced as the image formation was repeated.

[0073]

As described above, the organic semiconductor film of the present invention has a good electron transporting property and suppresses the humidity dependence of the semiconductor property. A coating film can be easily formed by coating, and even if another layer is formed thereon by coating, it does not dissolve or elute, so that a film having excellent characteristics of a laminated structure can be easily produced. . Therefore, an electrophotographic photoreceptor using this organic semiconductor film as an undercoat layer has excellent environmental stability as described above, and also has excellent dielectric breakdown resistance against contact charging.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an example of an electrophotographic photosensitive member including a photosensitive layer having a laminated structure according to the present invention.

FIG. 2 is a schematic configuration diagram illustrating an example of the electrophotographic apparatus of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Conductive support, 2 ... Charge generation layer, 3 ... Charge transport layer,
4 ... undercoat layer, 11 ... photoreceptor, 12 ... contact charging member, 1
3 Power supply, 14 Exposure device, 15 Development device, 16 Transfer device, 17 Cleaning device, 18 Static eliminator, 1
9: Fixing device.

Claims (7)

[Claims] An organic semiconductor film comprising an electron transporting pigment, a binder resin, and a silane coupling agent having an amine structure. 2. The organic semiconductor film according to claim 1, further comprising a silane coupling agent represented by the following formula (1). RxR'ySi (OR ") ₂ (1) (wherein, R, R 'and R" are each independently a hydrogen atom, a saturated or unsaturated hydrocarbon having 1 to 6 carbon atoms, phenyl or benzyl, A group selected from: x
And y are each an integer of 0 to 2, and x + y =
2. ) 3. An organic semiconductor film comprising an electron transporting pigment, an organic metal compound reactive with a binder resin and a silane coupling agent represented by the following formula (1). RxR'ySi (OR ") ₂ (1) (wherein, R, R 'and R" are each independently a hydrogen atom, a saturated or unsaturated hydrocarbon having 1 to 6 carbon atoms, phenyl or benzyl, A group selected from: x
And y are each an integer of 0 to 2, and x + y =
2. ) 4. The organic semiconductor film according to claim 1, wherein the electron transporting material is at least one selected from a polycyclic quinone pigment, a perylene pigment, and an azo pigment. . 5. The organic semiconductor film according to claim 4, wherein the polycyclic quinone pigment is a brominated anthrone. 6. A negatively charged electrophotographic photoreceptor having an undercoat layer and a photosensitive layer on a conductive support, wherein the undercoat layer is an organic material according to any one of claims 1 to 5. An electrophotographic photoreceptor formed of a semiconductor film. 7. An electrophotographic apparatus having an electrophotographic photosensitive member and a contact charging member arranged so as to be in contact with the photosensitive member, wherein the photosensitive member is the electrophotographic photosensitive member according to claim 6. Electrophotographic apparatus.