JP2002162758A - Electrophotographic photoconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoconductor in which unevenness density of image caused by harmful ozone and nitrogen oxides is hard to occur and also decrease in film thickness is hard to occur and the electrophotographic characteristic and the durability can be compatible with each other and an image forming apparatus mounting the electrophotographic photoconductor. SOLUTION: The image forming apparatus mounts the electrophotographic photoconductor. The electrophotographic photoconductor is used for full color image forming using a tandem system. The photoconductor comprises a charge generating layer and a charge transporting layer which are laminated. The charge transporting layer has a ratio of a charge transporting material to a binder of 10/14-10/20, a mobility of 1×10-6 cm2/V.sec or more at electric field strength of 20 V/μm and is used for an electrophotographic process using a process speed of 100 mm/sec or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor and an electrophotographic apparatus using the photoreceptor. More specifically, the present invention relates to a photoconductive layer comprising a charge generation layer containing an organic material and a charge transport layer. The present invention relates to a photoconductor laminated on a substrate, which is used for an electrophotographic printer, a copying machine, a facsimile, and the like, and an electrophotographic apparatus using the photoconductor.

[0002]

2. Description of the Related Art In recent years, an electrophotographic photosensitive member using an organic photoconductive material can be variously designed with no pollution, low cost, and flexibility in material selection. Has been proposed and put to practical use. The photosensitive layer of an organic electrophotographic photoreceptor is mainly composed of a layer in which an organic photoconductive material is dispersed in a resin, and a layer in which a charge generating material is dispersed in a resin (a charge generating layer) and a layer in which a charge transporting material is dispersed in a resin. Many structures have been proposed, such as a structure in which stacked layers (charge transport layers) are stacked, a single layer structure in which a charge generation material and a charge transport material are dispersed in a resin, and the like. Above all, a function-separated type photoconductor in which a charge transport layer is laminated on a charge generation layer as a photosensitive layer has excellent electrophotographic characteristics and durability, and is widely used in practice.

[0003] Most of such charge transport layers are mainly composed of a charge transport material and a binder resin. A practical photoreceptor is used in a weight ratio of the charge transporting material to the binder resin of 4: 6 to 6: 4. This is to maintain appropriate wear resistance, sensitivity, and repetition characteristics. In recent years, copiers and printers have both shifted from monochrome to color. The full-color image forming method includes a multiple transfer (transfer drum) method, a tandem method, an intermediate transfer member method (double transfer), and a collective transfer (multiple development) method. The tandem method is excellent because it can be operated at high speed.

[0004]

However, in the case of the tandem system, the speed is high, but the four process units have to be mounted, so that the size of the machine is reduced, the process arrangement is dense, and the photoconductor is also compact. It must have a small diameter and high printing durability. There is a problem that harmful ozone and nitrogen oxides are generated in the normal charging process.As a general machine design, a fan is installed around the process to discharge harmful substances. The charging unevenness immediately appears as image unevenness and is a fatal wound. Further, harmful ozone and nitrogen oxides cause great damage to the photoreceptor. For example, the active species adsorbs into the coating film of the photoreceptor immediately below the main charger, the resistance of a part of the photoreceptor decreases, and the latent image is disturbed. Further, when the charge transporting material (hereinafter, also referred to as “CTM”) is repeatedly damaged, a phenomenon that the charge transport material (hereinafter also referred to as “CTM”) is decomposed and a part of the charge is reduced is caused.

On the other hand, in order to improve the abrasion resistance of the photoreceptor, improvement of a binder resin and increase of a binder resin ratio are performed. As a result, the mobility in the charge transport layer is reduced, and the photoresponsiveness of the photoreceptor is reduced. Therefore, application to a high-speed process is difficult. Also, due to poor responsiveness, when the photoreceptor is used repeatedly in a state where the surface potential is not sufficiently attenuated, a potential change accompanying a rise in the residual potential increases, which causes a problem such as early deterioration of image quality. Accompany.
JP-A-6-202357 proposes to use oxytitanium phthalocyanine (TiOPc) and to use a specific charge-transporting material compound having a high mobility when the electrophotographic process is fast. Therefore, when the CTM / binder ratio is used at a ratio of 12/10 to 9/10, durability is reduced, and image density unevenness occurs due to damage of ozone and nitrogen oxides during repeated use, and sufficient characteristics are satisfied. May not be obtained. Also, Japanese Patent Application Laid-Open No. 10-282696 proposes that a specific antioxidant is contained to make the composition less susceptible to damage due to ozone resistance or nitrogen oxides. At present, there is a possibility that a large increase in the potential may not provide sufficient characteristics.

That is, recent digital copying machines and printers
Electrophotographic devices such as are required to be smaller and faster, and the photoreceptor characteristics include longer life due to improved abrasion resistance, higher sensitivity corresponding to higher speed, and protection against harmful ozone and nitrogen oxides. However, the photoconductors proposed so far are still insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to prevent image density unevenness and film thickness reduction due to harmful ozone and nitrogen oxides from occurring, and to improve electrophotographic characteristics. An object of the present invention is to provide an electrophotographic photoreceptor capable of achieving both durability and durability.

[0008]

The electrophotographic photoreceptor according to the present invention is used in a full-color image forming method using a tandem system, and its photosensitive layer has a charge generation as shown in FIG. This is a function-separated type photoconductor in which a layer 2 and a charge transport layer 3 are laminated. In such a photoreceptor, simply increasing the content of the binder resin in the charge transport layer results in a decrease in the ratio of the charge transport material, which is expected to lower the sensitivity of the photoreceptor. Further, when the content of the binder resin is reduced, the sensitivity of the photoconductor is improved, but the durability of the photoconductor is reduced. The photoreceptor of the present invention provides a photoreceptor having both durability and electrophotographic characteristics by optimally determining the charge transport material / binder ratio of the charge transport layer.

Conventionally, the charge transporting material / binder ratio is usually set to about 10/8 to 10/12 in the photoreceptor used. Electrons having a ratio of 10/14 to 10/20, a mobility of the charge transport layer of 1 × 10 ⁻⁶ cm ² / V · sec or more at an electric field strength of 20 V / μm, and a process speed of 100 mm / sec or more. An electrophotographic photoconductor, which is used in a photographic process.

In the present invention, first, a triphenylamine derivative compound represented by the following general formula (1) is used as a charge transporting material in the charge transporting layer of the photoreceptor. Since the compound has a high hole transporting property, it can maintain high sensitivity with high mobility even if it becomes rich in the binder as described above.

[0011]

Embedded image (Wherein, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group, or a substituted amino group. R ₂ represents an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group, or a substituted Represents an amino group.)

In the present invention, an aminestyryl derivative compound represented by the following general formula (2) is used as a charge transporting material in the charge transporting layer of the photoreceptor. It is represented by (4). The compound is
Since the hole transport property is high, high sensitivity and high sensitivity can be maintained even when the binder becomes rich as described above.

[0013]

Embedded image (Wherein, Ar ₁ represents an aryl group which may have a substituent, Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group, or an anthrylene group which may have a substituent, and R ₃ is hydrogen. An atom, a lower alkyl group or a lower alkoxy group, X represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Y may have a substituent. It represents a good aryl group or the following general formula (3).

[0014]

Embedded image

[0015]

Embedded image (In the formula, R ₃ represents the same group as described above.)

[0016]

Embedded image (Wherein, R ₄ represents a lower alkyl group or a lower alkoxy group, R ₅ represents a halogen atom or a lower alkyl group, Z represents a hydrogen atom, an aryl group which may have a substituent, and m is An integer of 0 to 4 and n represents an integer of 0 to 5)

In the present invention, a polycarbonate (bisphenol Z-type polycarbonate) represented by the following general formula (5) is used as a binder resin for the charge transport layer. Since the polycarbonate has good abrasion resistance, even if the binder ratio is 10/14, the polycarbonate has sufficient durability and can achieve a long life.

[0018]

Embedded image (In the formula, 1 represents an integer of 10 to 1000.)

In the present invention, at least two kinds of polycarbonates are used as the binder resin of the charge transport layer. Binder ratio 10 / due to good abrasion resistance
14 also has sufficient durability and can achieve a long life. Further, the molecular weight of the resin can be selected from a wide range, and it is easy to adjust the film loss and the viscosity of the coating solution. Further, in the present invention, at least polycarbonate as a binder resin of the charge transport layer,
By using the polyester represented by the following general formula (6) (manufactured by Toyobo Co., Ltd .: trade name; Byron 290), it is possible to prevent the viscosity from increasing when the binder is rich, and to obtain good coating properties. The electrical properties are also improved.

[0020]

Embedded image (Where g, h and i are integers of 1 to 10, v, w, x
And y represents an integer of 10 to 1000. )

In the present invention, the charge transport layer contains a lubricant (silicon oil, polyvinylidene fluoride, etc.). Thereby, the surface properties of the photoconductor are improved, and the durability is improved. Further, in the present invention, oxotitanyl phthalocyanine (TiOPc) having a peak at a Bragg angle 2θ = 27.3 ° ± 0.2 ° in the CuKα characteristic X-ray diffraction spectrum is used as the charge generating material of the charge generating layer. . The charge generation material has a large light absorption characteristic to general-purpose laser light in a digital process using reversal development, and has high sensitivity.

In the present invention, since the undercoat layer is formed between the conductive support and the photosensitive layer, image defects due to minute black spots and fog due to injection of electric charge from the substrate are less likely to occur. In addition, environmental characteristics are stabilized. The present invention is an image processing and forming apparatus equipped with the photoconductor of the first to twelfth aspects.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. FIG. 1 shows a schematic cross section of a laminated function-separated type photoconductor according to one embodiment of the present invention. In the figure, 1 indicates a conductive support (substrate), 2 indicates a charge generation layer, 3 indicates a charge transport layer, 4 indicates a photosensitive layer, and 5 indicates an undercoat layer.

Next, the material of the organic electrophotographic photosensitive member according to the present invention will be described. As the substrate, those having conductivity, for example, aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium,
Metals and alloy materials such as indium, titanium, gold, and platinum can be used, and in addition, polyester films, paper and metal films, and conductive particles obtained by depositing or applying aluminum, aluminum alloys, tin oxide, gold, indium oxide, and the like. And plastics containing conductive polymer and the like. These materials are used after being processed into a cylindrical shape, a cylindrical shape, or a thin film sheet shape. In particular, the conductive substrate used in the present invention is preferably cylindrical.

In the formation of the photosensitive layer, the conductive substrate is coated with the photosensitive substrate for reasons such as covering the conductive substrate with scratches and irregularities, preventing deterioration of the charging property when repeatedly used, and improving the charging characteristics in a low-temperature / low-humidity environment. An undercoat layer may be provided between the layer (charge generation layer / charge transport layer). The undercoat layer provided between the conductive support and the photosensitive layer contains titanium oxide, and the shape of the titanium oxide particles is at least one of acicular and dendritic, as shown in FIG. Any titanium oxide is used.

The needle shape is an elongated shape including a rod shape, a column shape, a spindle shape and the like. It refers to a shape having an aspect ratio of 1.5 or more, which is the ratio a / b between the major axis length a and the minor axis length b. Therefore, it does not necessarily have to be extremely elongated, and the tip does not need to be sharp. The average value of the aspect ratio is preferably in the range of 1.5 or more and 300 or less, more preferably in the range of 2 or more and 10 or less. If it is smaller than this range, it is difficult to obtain the effect as a needle, and if it is larger than this range, the effect as a needle does not change.

The term "dendritic" refers to an elongated and branched shape including a rod, a column, and a spindle. Therefore, the shape does not always have to be extremely elongated, and the shape does not need to be sharp and sharp. The particle diameter of the dendritic titanium oxide particles has a minor axis length of 1 μm or less and a major axis length of 100 μm.
The length is preferably not more than 0.5, but more preferably the short axis length is 0.5 μm or less and the long axis length is 10 μm or less.
When the particle size is not within this range, it is difficult to obtain a coating liquid for an undercoat layer having dispersion stability even if surface treatment is performed with a metal oxide or an organic compound.

The particle size and aspect ratio can be measured by a method such as a weight sedimentation method or a light transmission type particle size distribution measuring method. Is preferred. The undercoat layer contains the above-described needle-like or dendritic titanium oxide particles, but the dispersibility of titanium oxide is maintained for a long time as a coating solution for the undercoat layer, and a uniform film is formed as the undercoat layer. More preferably contains a binder resin. The content of the acicular or dendritic titanium oxide particles is 10% by weight or more and 99% by weight or less, preferably,
30% by weight or more and 99% by weight or less, more preferably 3% by weight or less.
The range is 5% by weight or more and 95% by weight or less. 10% by weight
If the content is lower, the sensitivity is reduced, the electric charge is accumulated in the undercoat layer, and the residual potential is increased. In particular, repetition characteristics under low temperature and low humidity become remarkable. On the other hand, if the content is more than 99% by weight, the storage stability of the coating solution for the undercoat layer is deteriorated, and the sedimentation of the titanium oxide particles is apt to occur.

In the present invention, a mixture of acicular or dendritic titanium oxide particles and granular titanium oxide particles may be used. When using any of acicular, dendritic, and granular titanium oxides, the crystal forms of titanium oxide include anatase type, rutile type, and amorphous, and any of them may be used. May be. The volume resistivity of the powder of the titanium oxide particles ^is preferably ¹⁰ 5 ~10 ^{1 0} Ωcm. If the volume resistivity of the powder is smaller than 10 ⁵ Ωcm, the resistance value of the undercoat layer decreases and the powder does not function as a charge blocking layer. For example, in the case of metal oxide particles subjected to a conductive treatment such as a tin oxide conductive layer doped with antimony, 1
0 ⁰ [Omega] cm to 10 ¹ very volume resistance of the powder is lowered and the [Omega] cm, in order undercoat layer deteriorates the chargeability of the photosensitive member properties does not function as a charge blocking layer using the same, the image It cannot be used because of fogging and black spots. Further, when the volume resistivity of the powder of titanium oxide particles is increased to 10 ¹⁰ Ωcm or more and becomes equal to or greater than the volume resistivity of the binder resin itself,
Since the resistance value of the undercoat layer is too high, the transport of carriers generated during light irradiation is suppressed and inhibited, and the residual potential increases and photosensitivity decreases, which is not preferable.

The surface of the dendritic titanium oxide particles is coated with a metal oxide such as Al ₂ O ₃ , ZrO ₂ or a mixture thereof as long as the volume resistance value of the powder of the titanium oxide particles is maintained in the above range. It is preferable to use one that has been made.
When using titanium oxide particles whose surface is untreated, the titanium oxide particles to be used are fine particles. Particle aggregation is inevitable. Therefore, when the undercoat layer is formed, a defect of the coating film or coating unevenness occurs to cause an image defect. In addition, since the injection of charges from the conductive support is likely to occur, the chargeability of the minute region is reduced and black spots are generated. Therefore, the surface of the titanium oxide particles is coated with a metal oxide such as Al ₂ O ₃ , ZrO ₂ or a mixture thereof to prevent aggregation of the titanium oxide and to provide an undercoating layer having excellent dispersibility and storage stability. A coating liquid is obtained.

Further, injection of electric charge from the conductive support is prevented.
Excellent image characteristics without black spots
Is obtained. Titanium oxide surface
Al oxide as the metal oxide coating₂O₃, ZrO₂
Is preferred. And also Al₂O ₃And ZrO₂Different metals
Surface treatment with both oxides provides better image characteristics
More favorable effect is expressed
You. Al₂O₃If surface treatment such as
Is hydrophilic and is not easily compatible with organic solvents.
Because the dispersibility of titanium is reduced and aggregation is likely to occur
It is not preferable for long-term use. Also, Fe₂O₃Such as
Coating the surface of titanium oxide with magnetic metal oxide
In the case, the phthalocyanine pigment contained in the photosensitive layer and
Interaction occurs chemically, reducing photoconductor properties, especially sensitivity
It is not preferable because the chargeability is deteriorated.

A metal oxide coating the surface of titanium oxide;
Al used as₂O₃, ZrO ₂Surface treatment amount
0.1% to 20% by weight of titanium oxide
Is preferred. If the throughput is less than 0.1% by weight,
Because the surface of titanium oxide cannot be coated sufficiently
The effect of the surface treatment is hardly exhibited. Over 20% by weight
Surface treatment that is sufficient
As a result, the characteristics will not change and
It is not preferable because it costs.

As the organic compound covering the surface of the titanium oxide, a general coupling agent can be used. Examples of the type of coupling agent include a silane coupling agent such as an alkoxysilane compound, halogen, nitrogen,
Examples thereof include a silylating agent in which an atom such as sulfur is bonded to silicon, a titanate coupling agent, and an aluminum coupling agent.

For example, as a silane coupling agent,
Tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, ethyltrimethoxysilane,
Diethyldimethoxysilane, phenyltriethoxysilane, aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane,
Allyltrimethoxysilane, allyltriethoxysilane, 3- (1-aminopropoxy) -3,3-dimethyl-1-propenyltrimethoxysilane, (3-acryloxypropyl) trimethoxysilane, (3-acryloxypropyl) Alkoxysilane compounds such as methyldimethoxysilane, (3-acryloxypropyl) dimethylmethoxysilane, N-3- (acryloxy-2-hydroxypropyl) -3-aminopropyltriethoxysilane, methyltrichlorosilane, methyldichlorosilane,
Chlorosilanes such as dimethyldichlorosilane and phenyltrichlorosilane; silazanes such as hexamethyldisilazane and octamethylcyclotetrasilazane; titanate coupling agents such as isopropyltriisostearoyl titanate and bis (dioctylpyrophosphate);
Examples include, but are not limited to, aluminum-based coupling agents such as acetoalkoxyaluminum diisopropylate.

When the metal oxide particles are subjected to a surface treatment with these coupling agents or used as a dispersant, one or more kinds of coupling agents may be used in combination. The method of subjecting the metal oxide particles to surface treatment is roughly classified into a pretreatment method and an integral blend method, and the pretreatment methods are further divided into a wet method and a dry method. The wet method is divided into a water treatment method and a solvent treatment method. As the water treatment method, a direct dissolution method, an emulsion method,
A known method such as an amine adduct method can be used.

The surface of the titanium oxide particles may be treated with a powder of the titanium oxide particles before or after the treatment with the coupling agent, or before and after the treatment with the coupling agent, or in the case where the titanium oxide particles are added to the organic solvent as a dispersant. The surface of the titanium oxide particles may be untreated, or may be coated with a metal oxide such as Al ₂ O ₃ , ZrO _2, or a mixture thereof, as long as the volume resistivity of the titanium oxide particles is maintained in the above range. .

The binder resin contained in the undercoat layer includes polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin,
Resins such as starch, polyurethane, polyimide, and polyamide can be used, but polyamide resins are preferably used. The reason for this is that the properties of the binder resin are that it does not dissolve or swell in the solvent used when forming the photoreceptor layer on the undercoat layer, and has excellent adhesion to the conductive support. This is because characteristics such as flexibility are required. More preferably, among the polyamide resins, an alcohol-soluble nylon resin can be used. For example, so-called copolymerized nylon obtained by copolymerizing 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, etc., and N
Nylon-modified nylon, such as N-alkoxyethyl-modified nylon and N-alkoxyethyl-modified nylon.

In the present invention, a common organic solvent can be used as the organic solvent used in the coating solution for the undercoat layer. However, when a more preferable alcohol-soluble nylon resin is used as the binder resin, 1 to
4 alone and a group consisting of other organic solvents such as dichloromethane, chloroform, 1,2-dichloroethane, 1,2-dichloropropane, toluene, tetrahydrofuran, and 1,3-dioxolane. It is preferable to use a system and a mixed system of organic solvents. Here, by mixing the above organic solvent, the dispersibility of titanium oxide is improved as compared with the alcohol-based solvent alone, and the storage stability of the coating solution (the number of days elapsed since the preparation of the coating solution for the undercoat layer is hereinafter referred to as pot life ) And regeneration of the coating solution. In addition, when the conductive support is immersed and coated in the undercoat layer coating solution to form the undercoat layer, coating defects and unevenness of the undercoat layer are prevented, and the photosensitive layer formed thereon is uniformly formed. By being able to be applied, it is possible to form an electrophotographic photoreceptor having very excellent image characteristics without film defects.

The thickness of the undercoat layer is preferably
0.01 μm or more and 20 μm or less, more preferably 0.0 μm or less
The range is 5 μm or more and 10 μm or less. If the thickness of the undercoat layer is less than 0.01 μm, the undercoat layer will not substantially function as an undercoat layer, and will not cover the defects of the conductive support to obtain uniform surface properties. Cannot be prevented, and the chargeability is reduced. On the other hand, when the thickness is larger than 20 μm, it is difficult to manufacture the photoconductor when the undercoat layer is applied by dip coating, and the sensitivity of the photoconductor is lowered.

As a method for dispersing the coating liquid for the undercoat layer, there are a ball mill, a sand mill, an attritor, a vibration mill, an ultrasonic dispersing machine, and the like. it can. Further, if necessary, a protective layer may be provided to protect the surface of the photosensitive layer.
For the surface protective layer, a thermoplastic resin or a light or thermosetting resin can be used. The protective layer may contain an ultraviolet absorber, an antioxidant, an inorganic material such as a metal oxide, an organometallic compound, an electron-accepting substance, and the like. Also, like the photosensitive layer, the protective layer may be mixed with a plasticizer such as a dibasic acid ester, a fatty acid ester, a phosphoric acid ester, a phthalic acid ester, and a chlorinated paraffin, as needed, to impart processability and plasticity. Alternatively, mechanical properties may be improved, and additives such as a leveling agent may be mixed.

The charge generation layer contains, as a main component, a charge generation material that generates charges by light irradiation, and may contain a known binder, plasticizer, and sensitizer as necessary. As the charge generating material, perylene imide, perylene pigments with perylene anhydride, quinacridone, polycyclic quinone pigments such as anthraquinone, metals and metal-free phthalocyanines, phthalocyanine pigments such as halogenated metal-free phthalocyanines, squarium dyes, Azurenium dye, thiapyrylium dye,
And azo pigments having a carbazole skeleton, styrylstilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bisstilbene skeleton, distyryloxadiazole skeleton or distyrylcarbazole skeleton. Particularly high charge generation pigments include metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing a fluorene ring and a fluorenone ring, bisazo pigments composed of aromatic amines, and trisazo pigments. A photoreceptor can be provided.

As the binder resin for the binder resin solution, melamine resin, epoxy resin, silicone resin,
Polyurethane resin, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate resin, phenoxy resin, polyvinyl butyral resin, polyarylate resin,
Polyamide resins, polyester resins, etc., as solvents for dissolving these resins, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, esters such as butyl acetate, tetrahydrofuran, ethers such as dioxane, benzene, toluene,
Aromatic hydrocarbons such as xylene, aprotic polar solvents such as N, N-dimethylformamide, dimethylsulfoxide and the like can be used.

As a method for forming the charge generation layer, there are a method in which a compound is directly formed into a film by vacuum evaporation, and a method in which the compound is dispersed in a binder resin solution and applied to form a film. The latter method is generally preferable. The method for mixing and dispersing the charge generating substance in the binder resin solution and the method for applying the same are the same as those for the undercoat layer. The ratio of the charge generation material in the charge generation layer is 30
The range is preferably 90 to 90% by weight. The thickness of the charge generation layer is
0.05-5 μm, preferably 0.1-2.5 μm
m.

The charge transport layer provided on the charge generation layer contains, as essential components, a charge transport material having the ability to receive and transport charges generated by the charge generation material, and a binder. Plasticizers, sensitizers, lubricants and the like. Examples of the charge transport material include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, and oxadiazole. Derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine Electron-donating substance such as a compound based on tetraphenyldiamine, a compound based on triphenylmethane, a compound based on stilbene, an azine compound having a 3-methyl-2-benzothiazoline ring, Olenone derivative, dibenzothiophene derivative, indenothiophene derivative, phenanthrenequinone derivative, indenopyridine derivative, thioxanthone derivative, benzo [c] cinnoline derivative, phenazine oxide derivative, tetracyanoethylene, tetracyanoquinodimethane, promanyl, chloranil And electron accepting substances such as benzoquinone. In the present invention, a triphenylamine derivative and an aminestyryl derivative are particularly preferred.

The compound represented by formula (2) used in the present invention will be described in detail. In the general formula (2), when Ar ₁ is an aryl group having a substituent, examples of the substituent include a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, and a number of carbon atoms. Is 5
6, a cycloalkyl group, a benzyl group, a phenyl group or a halogen atom. When the substituent is a lower alkyl group or a lower alkoxy group, it is further substituted with a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom. When the substituent is a benzyl group or a phenyl group, it may be further substituted with a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom.

The aryl group of Ar ₁ includes a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group, a pyrenyl group and the like. When Ar ₂ is a substituted phenylene group, a naphthylene group, a biphenylene group, or an anthrylene group, the substituent may be a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxy group having 1 to 4 carbon atoms, or halogen. When the substituent is a lower alkyl group or a lower alkoxy group, it may be further substituted with a lower alkoxy group having 1 to 4 carbon atoms or a halogen atom.

When X, Y or Z in the above formula is an aryl group having a substituent, examples of the substituent include the same substituents as those described above that Ar ₁ can have. When X is an alkyl group having a substituent, examples of the substituent include a lower alkoxy group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 6 carbon atoms, and a halogen atom. Examples of the X, Y or Z aryl group include a phenyl group, a naphthyl group, a biphenylyl group, an anthryl group and a pyrenyl group. Specific examples of the compound represented by the general formula (2) used in the present invention include the following, but are not limited thereto.

[0048]

Embedded image

[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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The binder resin constituting the charge transport layer may be any resin having compatibility with the charge transport material.
For example, polycarbonate and copolymerized polycarbonate,
Polyarylate, polyvinyl butyral, polyamide,
Examples include polyester, polyketone, epoxy resin, polyurethane, polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. These may be used alone or in combination of two or more. Among them, bisphenol Z-type polycarbonate, bisphenol Z
Mixing of type polycarbonate and other polycarbonate, mixing of bisphenol Z type polycarbonate and polyester, mixing of polycarbonate bisphenol Z and other polycarbonate and polyester provide film forming property and abrasion resistance,
It is preferable in terms of electrical characteristics and the like.

In particular, in the present invention, a mixture of a copolymer of bisphenol A type polycarbonate and biphenol type polycarbonate with a bisphenol Z type polycarbonate, a copolymer of bisphenol A type polycarbonate with a biphenol type polycarbonate and polysiloxane and a bisphenol A Mixing with a Z-type polycarbonate is preferred. In addition, as a solvent for dissolving these materials,
Alcohols such as methanol and ethanol, acetone,
Ketones such as methyl ethyl ketone and cyclohexanone,
Ethers such as ethyl ether and tetrahydrofuran,
Examples thereof include aliphatics such as chloroform, dichloroethane, and dichloromethane, halogenated hydrocarbons, and aromatics such as benzene, chlorobenzene, and toluene.

The coating solution for the charge transport layer of the present invention contains vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, organic phosphorus compounds, etc. as antioxidants. You may mix and use. The charge transport layer coating solution is prepared by dissolving a charge transport material in a binder resin solution, and the coating method is the same as that for the undercoat layer and the charge generation layer. The film thickness is
It is 10 to 50 μm, preferably 15 to 40 μm.

After these photosensitive layers are sequentially coated and formed by the above-described method, each photosensitive layer is dried using a dryer such as hot air or far infrared rays, and the formation of the photosensitive member is completed. Drying is preferably performed at 40 ° C. to 130 ° C. for 10 minutes to 2 hours. FIG.
1 is a schematic front sectional view showing a configuration of a digital color copying machine 1 which is an image forming apparatus according to an embodiment of the present invention.
A document table 111 and an operation panel, which will be described later, are provided on the upper surface of the copying machine main body 1, and an image reading unit 110 and an image forming unit 210 are provided inside the copying machine main body 1.
The upper surface of the platen 111 is supported so as to be openable and closable with respect to the platen 111, and a two-sided automatic document feeder (RADF;
g Automatic Document Feeder) 112 is attached.

Further, the automatic two-sided automatic document feeder 112
First, the document is conveyed such that one surface of the document faces the image reading unit 110 at a predetermined position on the document table 111,
After the image reading for this one side is completed,
The original is inverted so that the other surface faces the image reading unit 110 at a predetermined position on the original
To be conveyed toward. Then, after the two-sided image reading for one document is completed, the double-sided automatic document feeder 112 discharges this document and performs a double-sided conveyance operation for the next document. The operation of conveying the document and reversing the front and back is controlled in relation to the operation of the entire copying machine.

The image reading section 110 is arranged below the document table 111 for reading an image of a document conveyed onto the document table 111 by the automatic duplex document feeder 112. The image reading unit 110 includes a document scanning body 113, 1 that reciprocates in parallel along the lower surface of the document table 111.
14, an optical lens 115, and a photoelectric conversion element CC
And a D line sensor 116.

The original scanning bodies 113 and 114 are composed of a first scanning unit 113 and a second scanning unit 114. The first scanning unit 114 has an exposure lamp for exposing the surface of the document image and a first mirror for deflecting a reflected light image from the document in a predetermined direction. It reciprocates in parallel at a predetermined scanning speed while maintaining the distance. The second scanning unit 114 has second and third mirrors for further deflecting the reflected light image from the document deflected by the first mirror of the first scanning unit 113 in a predetermined direction. It reciprocates in parallel with one scanning unit 113 while maintaining a constant speed relationship.

The optical lens 115 reduces the reflected light image from the document deflected by the third mirror of the second scanning unit and forms the reduced light image at a predetermined position on the CCD line sensor 116. It is. The CCD line sensor 116 photoelectrically converts the formed light image in order and outputs it as an electric signal. CCD line sensor 116
Reads a black and white image or a color image,
A three-line color C that can output line data that is color-separated into each color component of (red), G (green), and B (blue)
It is a CD. The document image information converted into an electric signal by the CCD line sensor 116 is further transferred to an image processing unit (shown in FIG. 4), which will be described later, and subjected to predetermined image data processing.

Next, the configuration of the image forming unit 210 and the configuration of each unit related to the image forming unit 210 will be described.
Below the image forming unit 210, there is provided a paper feed mechanism 211 that separates sheets (recording media) P stacked and accommodated in a sheet tray one by one and supplies the separated sheets to the image forming unit 210. The paper P separated and supplied one by one is
The timing is controlled by a pair of registration rollers 212 disposed in front of the image forming unit 210 and the image forming unit 2
It is transported to 10. Further, the sheet P on which an image is formed on one side is re-supplied and conveyed to the image forming unit 210 in synchronization with the image formation of the image forming unit 210.

Below the image forming section 210, a transfer / conveyance belt mechanism 213 is disposed. The transfer / transport belt mechanism 213 is provided between the drive roller 214 and the driven roller 215 to extend substantially in parallel with the transfer / transport belt 21.
6, the paper P is electrostatically attracted and transported. Then, in the vicinity of the lower side of the transfer conveyance belt 216,
A pattern image detection unit is provided. further,
A fixing device 217 for fixing the toner image transferred and formed on the paper P on the paper P is disposed downstream of the transfer and transport belt mechanism 213 in the paper transport path. The sheet P that has passed through the nip between the pair of fixing rollers of the fixing device 217 passes through the conveyance direction switching gate 218, and
The paper is discharged by a discharge roller 219 onto a paper discharge tray 220 attached to the outer wall of the copying machine main body 1.

The switching gate 218 is connected to the sheet P after fixing.
Is selectively switched between a path for discharging the sheet P to the copying machine main body 1 and a path for re-supplying the sheet P toward the image forming unit 210. The sheet P whose transport direction has been switched again toward the image forming unit 210 by the switching gate 218 is turned upside down via the switchback transport path 221, and then the image forming unit 210 is turned over.
Is supplied again. Further, above the transfer conveyance belt 216 in the image forming unit 210, the transfer conveyance belt 21 is provided.
6, the first image forming station Pa, the second
Image forming station Pb, third image forming station Pc, and fourth image forming station Pd,
They are arranged in order from the upstream side of the paper transport path.

The transfer conveyance belt 216 is driven by a driving roller 214.
In FIG. 3, the sheet P is driven by friction in the direction indicated by the arrow Z, and is carried by the sheet feeding mechanism 211 as described above.
Conveyed sequentially to Pd. Each image station Pa to Pd
Have substantially the same configuration. Each of the image stations Pa, Pb, Pc, and Pd is a photosensitive drum 222a, 222b, 2 that is driven to rotate in the direction of arrow F shown in FIG.
22c and 222d, respectively.

Around the photosensitive drums 222a to 222d, chargers 223a, 223b, 223c, 22 for uniformly charging the photosensitive drums 222a to 222d, respectively.
3d and developing devices 224a and 224 for developing the electrostatic latent images formed on the photosensitive drums 222a to 222d, respectively.
4b, 224c, 224d and transfer dischargers 225a, 225b, 225c, 225d for transferring the developed toner images on the photosensitive drums 222a to 222d to the paper P.
Cleaning devices 226a, 226b, and 2 for removing toner remaining on photoconductor drums 222a to 222d.
26c and 226d are photosensitive drums 222a to 222d
Are sequentially arranged along the rotation direction.

Each of the photosensitive drums 222a to 222d
Above the laser beam scanner unit 227
a, 227b, 227c, and 227d, respectively. Laser beam scanner unit 227a-2
27d is a semiconductor laser device (not shown) for emitting dot light modulated according to image data, a polygon mirror (deflecting device) 240 for deflecting a laser beam from the semiconductor laser device in the main scanning direction, and a polygon. It is composed of an fθ lens 241 and mirrors 242 and 243 for forming an image of the laser beam deflected by the mirror 240 on the surfaces of the photosensitive drums 222a to 222d.

The laser beam scanner 227a receives a pixel signal corresponding to the black component image of the color original image, the laser beam scanner 227b receives a pixel signal corresponding to the cyan component image of the color original image, and the laser beam scanner 227c. The pixel signal corresponding to the magenta color component image of the color original image is output to the laser beam scanner 2
A pixel signal corresponding to the yellow component image of the color document image is input to 27d.

As a result, an electrostatic latent image corresponding to the color-converted original image information is formed on each of the photosensitive drums 222a to 222d. The developing device 227a receives the black toner, the developing device 227b receives the cyan toner, the developing device 227c receives the magenta toner, and the developing device 227c.
27d contains yellow toner, respectively, and the electrostatic latent images on the photosensitive drums 222a to 222d are:
The image is developed with the toner of each color. As a result, the document image information color-converted by the image forming unit 210 is reproduced as a toner image of each color.

Further, between the first image forming station Pa and the paper feeding mechanism 211, a paper suction charger 228 is provided, and the suction charger 228 charges the surface of the transfer conveyance belt 216. The sheet P supplied from the sheet feeding mechanism 211 is conveyed without shifting between the first image forming station Pa and the fourth image forming station Pd in a state where the sheet P is securely attracted onto the transfer conveying belt 216. On the other hand, the fourth image station Pd and the fixing device 2
A static eliminator 229 is provided almost directly above the drive roller 214 between the roller 17 and the roller 17. An alternating current is applied to the neutralizer 229 to separate the paper P electrostatically attracted to the transport belt 216 from the transfer transport belt 216.

In the digital color copying machine having the above configuration, cut sheet-shaped paper is used as the paper P. The sheet P is sent out from the sheet cassette and fed to the sheet feeding mechanism 2.
When the paper P is fed into the guide of the paper feed conveyance path 11, the leading end of the paper P is detected by a sensor (not shown),
It is temporarily stopped by the pair of registration rollers 212 based on a detection signal output from this sensor. And
The paper P is fed onto the transfer / conveying belt 216 rotating in the direction of arrow Z in FIG. 3 at the timing of each of the image stations Pa to Pd. At this time, since the transfer conveyance belt 216 is given a predetermined charge by the attraction charger 228 as described above, the paper P is transferred to each image station P.
While passing through a to Pd, it is stably conveyed and supplied.

In each of the image stations Pa to Pd, a toner image of each color is formed, and is superposed on the support surface of the paper P conveyed by being electrostatically attracted and conveyed by the transfer conveyance belt 216. Fourth image station Pd
Is completed, the paper P is sequentially transferred from the leading end portion thereof to the transfer conveyance belt 216 by the discharger for static elimination.
It is peeled off from above and guided to the fixing device 217. Finally, the paper P on which the toner image has been fixed is discharged onto a paper discharge tray 220 from a paper discharge port (not shown).

In the above description, laser beam scanning and exposure are performed by the laser beam scanner units 227a to 227d, thereby performing optical writing on the photosensitive member. However, a writing optical system (LED head) including a light emitting diode array and an imaging lens array may be used instead of the laser beam scanner unit. The LED head is smaller in size than the laser beam scanner unit, and has no moving parts and is silent. Therefore, it can be suitably used in an image forming apparatus such as a tandem type digital color copying machine which requires a plurality of optical writing units.

[Examples] The present invention will be described in more detail below with reference to examples and the like, but the present invention is not limited to these examples and the like. (Example 1) As a conductive support, φ40 mm × L34
A 0 mm aluminum cylindrical tube was used. 4 parts by weight of titanium oxide particles and 6 parts by weight of a copolymer nylon resin (trade name: CM8000, manufactured by Toray Industries, Inc.) as a binder resin were added to a mixed solvent of 35 parts by weight of methyl alcohol and 65 parts by weight of 1,2-dichloroethane. After that, the mixed solvent was dispersed in a paint shaker for 8 hours, and the tank was filled with a coating solution for an undercoat layer, and the aluminum cylindrical support was immersed, pulled up, and coated with 0.9 μm. Was formed on an aluminum drum. Since the solvent evaporates during drying, the titanium oxide particles and the copolymerized nylon resin remain as an undercoat layer, and the content of the titanium oxide particles is 40% by weight and the content of the binder resin is 60% by weight.

Next, the CuKα characteristic X as shown in FIG.
2 parts of an oxotitanyl phthalocyanine pigment having a clear peak at least 27.3 ° in Bragg angle (2θ ± 0.2 °) in line diffraction and 1 part of a polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd .; trade name: Esrec BMS) 97 parts of dichloroethane was dispersed in a ball mill for 12 hours to prepare a dispersion. The dispersion was filled in a tank, and the aluminum drum provided with the undercoat layer was immersed, pulled up and coated to a thickness of about 0. A 0.2 μm charge generation layer was formed on the undercoat layer.

Further, 100 parts by weight of a charge transporting material (triphenylamine derivative compound) represented by the following structural formula (7) and 1200 parts by weight of tetrahydrofuran and a polycarbonate resin (Mitsubishi Engineering Plastics) represented by the above general formula (5) Product name: Iupilon (Z-
200)) 200 parts by weight and a silicone leveling agent (Shin-Etsu Chemical Co., Ltd .; trade name: KF-96) 0.000
One part by weight was mixed to prepare a coating solution for coating the charge transport layer. On the charge generation layer formed as described above, a coating solution for coating a charge transport layer is applied by dip coating and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of about 23 μm.
A laminated function-separated type photoconductor as shown in FIG. 1 was produced. Here, the amount of the solvent was changed as appropriate in consideration of viscosity and coatability.

[0078]

Embedded image In this embodiment, the process speed is 117 mm / s
ec.

(Example 2) The charge transporting material was replaced with the compound of the formula (I-
A photoreceptor was formed in the same manner as in Example 1, except that the compound of 1) was used. Example 3 A photoconductor was formed in the same manner as in Example 1, except that the compound of the formula (I-2) was used as the charge transporting material.

Example 4 A charge transporting material was prepared according to the formula (I-
A photoreceptor was formed in the same manner as in Example 1, except that the compound of 3) was used. (Example 5) A photoconductor was formed in the same manner as in Example 1, except that the compound of the formula (I-4) was used as the charge transporting material.

Example 6 A photoreceptor was formed in the same manner as in Example 2, except that 200 parts by weight of the polycarbonate resin in the coating solution for the charge transport layer was changed to 140 parts by weight. Example 7 A photoreceptor was formed in the same manner as in Example 2, except that 200 parts by weight of the polycarbonate resin in the coating solution for the charge transport layer was changed to 160 parts by weight.

(Example 8) The polycarbonate resin in the coating solution for the charge transporting layer was manufactured by Mitsubishi Engineering-Plastics Corporation; trade name: Iupilon (Z-400).
A photoconductor was formed in the same manner as in Example 2, except that 0 parts by weight and 100 parts by weight of a polycarbonate resin (manufactured by Idemitsu Kosan Co., Ltd .; trade name: B-300) represented by the following general formula were used.

[0083]

Embedded image

Example 9 The polycarbonate resin in the coating solution for the charge transport layer was replaced with a resin (manufactured by Mitsubishi Engineering-Plastics Corporation; trade name: Iupilon (Z-200)).
A photoconductor was formed in the same manner as in Example 2, except that 0 parts by weight and 100 parts by weight of a copolymer resin of bisphenol A-type polycarbonate, biphenyl-type polycarbonate and polysiloxane represented by the following general formula (9) were used.

[0085]

Embedded image

(Example 10) Polycarbonate resin (Mitsubishi Engineering Plastics; trade name: Iupilon (Z-200)) 10 in the coating solution for the charge transport layer
Photoreceptor in the same manner as in Example 2 except that 0 parts by weight was changed to 180 parts by weight and the polyester resin represented by the general formula (6) (manufactured by Toyobo Co .; trade name: Byron (V290)) was changed to 20 parts by weight. Was formed.

Example 11 A photoconductor was formed in the same manner as in Example 2, except that 0.0001 part by weight of the silicone leveling agent in the coating solution for the charge transport layer was changed to 1 part by weight of polyvinylidene fluoride. Example 12 A photosensitive member formed in the same manner as in Example 2 was operated at a process speed of 140 mm / sec.

Comparative Example 1 A photoreceptor was formed in the same manner as in Example 2, except that 200 parts by weight of the polycarbonate resin in the coating solution for the charge transport layer was changed to 100 parts by weight. (Comparative Example 2) A photoconductor was formed in the same manner as in Example 2, except that the polycarbonate resin in the coating solution for the charge transport layer was changed to 250 parts by weight.

(Comparative Example 3) The charge transport material (triphenylamine derivative compound) in the coating solution for the charge transport layer was replaced with a hydrazone-based charge transport material 4-dibenzylamino-2-benzaldehyde-1,1-diphenylhydrazone ( A photoreceptor was formed in the same manner as in Example 1, except that the product was made by Annan Co., Ltd .; trade name: “CTC191”. (Comparative Example 4) A photoconductor was formed in the same manner as in Example 1, except that the charge transport material (triphenylamine derivative compound) in the coating solution for the charge transport layer was changed to a hydrazone-based compound represented by the following general formula. .

[0090]

Embedded image

Comparative Example 5 A photoconductor was formed in the same manner as in Example 1, except that the polycarbonate resin in the coating solution for the charge transport layer was changed to bisphenol A type polycarbonate and the solvent was changed to dichloromethane. (Comparative Example 6) A photoconductor was formed in the same manner as in Example 1, except that no silicone-based leveling agent was used in the coating solution for the charge transport layer.

(Comparative Example 7) Bragg angle (2θ ± 0.2) in CuKα characteristic X-ray diffraction in the coating solution for the charge generation layer.
A photoreceptor was formed in the same manner as in Example 1 except that an oxo titanyl phthalocyanine pigment having a clear peak at 2 °) at least 27.3 ° was changed to α-type titanyl phthalocyanine. Comparative Example 8 A photoconductor was formed in the same manner as in Example 1, except that the undercoat layer was not formed.

The electrophotographic photosensitive member produced as described above is mounted on a full-color copying machine using a tandem method (AR-C150 manufactured by Sharp Corp. modified so that the process speed can be arbitrarily set). The surface potential of the photoconductor in the developing unit, specifically, the surface potential Vo of the photoconductor in the dark after excluding the exposure process and the surface potential VL of the photoconductor after laser exposure were measured in order to check the chargeability. Further, the image characteristics of each of these photoreceptors at the initial stage and after copying 40,000 sheets, and the amount of film reduction were also measured. Further, the mobility of the charge transport layer was measured by a xerographic TOF method using a drum tester CYNTHIA (manufactured by GENTEC). These results are shown in Table 1.

[0094]

[Table 1]

Although the sample of Comparative Example 1 had no problem in both the initial sensitivity and the initial image, the film was remarkably thin and fogged in the image after 30,000 copies. The sample of Comparative Example 2 was poor in responsiveness due to low mobility, poor in charging property and sensitivity, fogged from the beginning, and had a low density. The sample of Comparative Example 3 had lower sensitivity and lower concentration than Comparative Example 2. The sample of Comparative Example 4 had no problem at the initial stage, but after 20,000 sheets, image density unevenness (image blur) considered to be damaged by ozone and nitrogen oxides was clearly generated, and the image was not an endurable image.

The sample of Comparative Example 5 had no problem at the initial stage, but after 30,000 copies, image density unevenness (blurred image) considered to be caused by ozone and nitrogen oxides occurred. Film loss was also larger than that of the same charge transport material / binder ratio. Although the sample of Comparative Example 6 had no problem at the initial stage, unevenness in image density (white stripes and black stripes) occurred due to uneven film thickness after 20,000 sheets, and charge transport also occurred after 40,000 sheets. The material / binder ratio was higher than the same.
The sample of Comparative Example 7 had poor initial sensitivity and low concentration.
In the sample of Comparative Example 8, black spots and fogging occurred from the beginning, but the image after 40,000 sheets was the same as the initial stage and did not change.

As described above, in the photoreceptor of the present invention, a photoreceptor having both durability and electrophotographic characteristics can be obtained by optimally determining the charge transport material / binder ratio of the charge transport layer. In addition, the mobility of the charge transport layer is 20 V /
Even when used in an electrophotographic process with a process speed of 1 × 10 ⁻⁶ cm ² / V · sec or more at μm and a process speed of 100 mm / sec or more, by using a specific compound, the hole transport property is high and the binder is rich. Even after that, high sensitivity can be maintained with high mobility, and by using a specific binder resin, abrasion resistance is good, sufficient durability can be achieved, and a long life can be achieved. On the other hand, by incorporating a lubricant into the charge transport layer, the surface properties of the photoreceptor are improved, and the durability is further improved.

In addition, oxotitanyl phthalocyanine (T
By using iOPc), in a digital process using reversal development, it has a large light absorption characteristic to general-purpose laser light and has high sensitivity. Further, it can be seen that the formation of the undercoat layer between the conductive support and the photosensitive layer makes it difficult to generate image defects due to minute black spots and fog due to injection of electric charge from the substrate.

[0099]

According to the present invention, there is provided an electrophotographic apparatus capable of maintaining image density unevenness due to harmful ozone or nitrogen oxide, good abrasion resistance and high sensitivity, and achieving both electrophotographic characteristics and durability. A photoreceptor was obtained. Further, the cost of the charge transport layer can be made relatively inexpensive, making it possible to cope with downsizing and high-speed processes.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a laminated function-separated type photoconductor according to an embodiment of the present invention.

FIG. 2 is a schematic view of the shape of dendritic particles of titanium oxide contained in an undercoat layer.

FIG. 3 is a schematic front sectional view showing a configuration of a digital color copying machine 1 which is an image forming apparatus according to the embodiment of the present invention.

FIG. 4: Bragg angle (2θ ± 0.2 °) of at least 2
The CuKα characteristic X-ray diffraction diagram of titanyl phthalocyanine having a clear peak at 7.3 °.

[Description of Signs] 1 conductive support 2 charge generation layer 3 charge transport layer 4 photosensitive layer 5 undercoat layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) G03G 5/06 371 G03G 5/06 371 5/14 101 5/14 101 (72) Inventor Yuriko Shindo Abeno, Osaka City, Osaka Prefecture (22) Inventor Arihiko Kawahara 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Prefecture F-term (reference) 2H068 AA13 AA14 AA19 AA20 AA21 AA28 AA34 AA35 AA41 BA12 BA13 BA39 BB26 BB27 BB34 FA01 FB11

Claims (14)

[Claims] 1. An electrophotographic photoreceptor used in a full-color image forming method using a tandem system, wherein the photoreceptor comprises a charge generation layer and a charge transport layer, and the charge transport layer comprises a charge transport material. / Binder ratio is 10/14 to 10 /
20 and a mobility of 1 at an electric field strength of 20 V / μm.
× ¹⁰ -6 ^cm 2 / V is at · sec or more, and electrophotographic photoreceptor process speed is characterized by using the above electrophotographic process 100 mm / sec. 2. The electrophotographic photoconductor according to claim 1, wherein the charge transporting layer contains a triphenylamine derivative represented by the following general formula (1) as a charge transporting material. Embedded image (Wherein, R ₁ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group, or a substituted amino group. R ₂ represents an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group, or a substituted Represents an amino group.) 3. The electrophotographic photoconductor according to claim 1, wherein the charge transport layer contains an aminestyryl derivative represented by the following general formula (2) as a charge transport material. Embedded image (Wherein, Ar ₁ represents an aryl group which may have a substituent, Ar ₂ represents a phenylene group, a naphthylene group, a biphenylene group, or an anthrylene group which may have a substituent, and R ₃ is hydrogen. An atom, a lower alkyl group or a lower alkoxy group, X represents a hydrogen atom, an alkyl group which may have a substituent or an aryl group which may have a substituent, and Y may have a substituent. It represents a good aryl group or the following general formula (3). 4. The electrophotographic photoconductor according to claim 3, wherein Y in the general formula (2) is a group represented by the following general formula (3). Embedded image (In the formula, R ₃ represents the same group as described above.) 5. The electrophotographic photoconductor according to claim 3, wherein Y in the general formula (2) is a group represented by the following general formula (4). Embedded image (Wherein, R ₄ represents a lower alkyl group or a lower alkoxy group, R ₅ represents a halogen atom or a lower alkyl group, Z represents a hydrogen atom, an aryl group which may have a substituent, and m is An integer of 0 to 4 and n represents an integer of 0 to 5) 6. The electrophotographic photoreceptor according to claim 1, wherein a polycarbonate represented by the following general formula (5) is used as a binder resin for the charge transport layer. Embedded image (In the formula, 1 represents an integer of 10 to 1000.) 7. The electrophotographic photoconductor according to claim 1, wherein at least two kinds of polycarbonates are used as a binder resin of the charge transport layer. 8. The electrophotographic photoconductor according to claim 1, wherein at least polycarbonate and a polyester represented by the following general formula (6) are used as a binder resin of the charge transport layer. . Embedded image (Where g, h and i are integers of 1 to 10, v, w, x
And y represents an integer of 10 to 1000. ) 9. The electrophotographic photosensitive member according to claim 1, wherein the charge transport layer contains a lubricant. 10. The electrophotographic photoconductor according to claim 9, wherein the lubricant is silicone oil. 11. The charge generation material of the charge generation layer is oxotitanyl phthalocyanine (TiOPc) and CuK
In the α characteristic X-ray diffraction spectrum, the Bragg angle 2θ ±
The electrophotographic photoconductor according to any one of claims 1 to 10, wherein the photoconductor has a peak at 0.2 ° = 27.3 °. 12. The electrophotographic photoreceptor according to claim 1, wherein an undercoat layer is formed between the conductive support and the photosensitive layer. 13. An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1. 14. A charge transport material / binder ratio of 10 /
14 to 10/20, and the mobility is 20 V / μ of the electrolytic strength.
100 m / sec using a laminated photoreceptor having a charge transport layer of 1 × 10 ⁻⁶ cm ² / V · sec or more at m
A full-color image forming apparatus using the tandem system with the above process speed.