JP2007086209A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming method by which suppression of occurrence of a ghost and improvement of transfer efficiency and uniformity of image quality can be achieved in a high level and in a well balanced manner. <P>SOLUTION: The image forming apparatus comprises an electrophotographic photoreceptor, a charging means, an exposure means, a developing means and a transfer means, wherein an electrophotographic photoreceptor having an undercoat layer containing metal oxide particles treated with a silane coupling agent between a conductive support and a photosensitive layer is used as the above electrophotographic photoreceptor, and a transfer current satisfying conditions represented by formula (1): 0.16≤I/S<SB>p</SB>≤0.20 or a transfer voltage satisfying conditions represented by formula (2): 15.5≤V/S<SB>p</SB>≤20.5 is supplied from the transfer member toward the electrophotographic photoreceptor in a state where a transfer medium lies between the electrophotographic photoreceptor and the transfer member. In the formula (1), I denotes a transfer current (unit: μA) and S<SB>p</SB>denotes a process speed (unit: mm/s) of the electrophotographic photoreceptor. In the formula (2), V denotes a transfer voltage (unit; V) and S<SB>p</SB>denotes a process speed (unit: mm/s) of the electrophotographic photoreceptor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic image forming apparatus and an image forming method.

  An electrophotographic image forming apparatus can obtain high-speed and high-quality printing, and is used in electrophotographic apparatuses such as copying machines, laser printers, and LED printers.

  The electrophotographic image forming method includes a charging step for uniformly charging the surface of an electrophotographic photosensitive member (hereinafter sometimes referred to as “photosensitive member”) to a predetermined polarity and potential, and image exposure of the charged surface of the photosensitive member. In general, it includes an exposure process for forming an electrostatic latent image by toner, a developing process for developing the electrostatic latent image with toner to form a toner image, and a transfer process for transferring the toner image from a photoreceptor to an image output medium. It is.

  Of the above processes, the transfer process is mainly the one in which the toner image is directly transferred from the photoconductor to the paper. However, in recent years, since the degree of freedom of the paper to be transferred has expanded, the intermediate transfer medium is used. An intermediate transfer system that transfers a toner image from a photosensitive member to an image output medium is widely used (see, for example, Patent Document 1). This intermediate transfer method also has an advantage that color misregistration can be suppressed when a color image is formed by superimposing a plurality of color toner images.

  As a photosensitive member used in the image forming apparatus, a photosensitive member in which a photosensitive layer using a photoconductive material is formed on a conductive support is known. In this photoreceptor, in order to improve chargeability, improve adhesion between the support and the photosensitive layer, conceal defects on the support surface, reduce image defects due to pinhole leakage, etc. Conventionally, an undercoat layer is provided between the photosensitive layer and the photosensitive layer.

  Examples of the material for forming the undercoat layer include thermoplastic resins such as polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl methyl ether, polyamide, thermoplastic polyester, phenoxy resin, casein, gelatin, and nitrocellulose. In addition, thermosetting resins such as polyimide, polyethyleneimine, epoxy resin, melamine resin, phenol resin, and polyurethane resin are known.

Furthermore, in order to further improve the photoreceptor characteristics and obtain a good image quality, various studies have been made on the composition of the undercoat layer. For example, a photoreceptor in which a conductive polymer is blended with a resin constituting the undercoat layer. (For example, refer to Patent Document 2), a photoconductor in which conductive powder is dispersed in a resin constituting the undercoat layer (for example, refer to Patent Document 3) has been proposed.
Japanese Laid-open Patent Publication JP-A-58-95774 JP 58-93063 A

  However, in the conventional image forming apparatus, the residual potential of the photoconductor increases in the process of repeatedly performing image formation, and the exposure history (exposure image) in the previous image formation appears in the next image formation. There is a problem that an image quality defect called a ghost is likely to occur.

  In addition, when conductivity is imparted to the undercoat layer as in the photoreceptors described in Patent Documents 2 and 3, a large number of electron (electron) and hole (hole) conduction paths are formed in the undercoat layer. Thus, it is expected that the charge transfer can be facilitated and the increase in the residual potential can be suppressed. However, in practice, a sufficient ghost suppression effect cannot be obtained. In particular, in the case of a photoreceptor in which conductive powder is dispersed in the resin constituting the undercoat layer, the dispersibility of the conductive powder tends to be insufficient, and thus the increase in residual potential cannot be sufficiently suppressed. Also, there is a problem that sensitivity is lowered in the process of repeatedly performing image formation.

  One of the factors that cause ghosting is the influence of the transfer current and transfer voltage (primary transfer current and primary transfer voltage in the case of an intermediate transfer type image forming apparatus) in the transfer process. If it is lowered, the occurrence of ghost can be suppressed to some extent. However, if the transfer current or transfer voltage is lowered, transfer efficiency and image quality uniformity are impaired, and this is not a fundamental solution for improving image quality.

  The present invention has been made in view of the above-described problems of the prior art, and is an image forming apparatus capable of achieving a high level balance between suppressing ghosting and improving transfer efficiency and image quality uniformity. An object is to provide an image forming method.

  In order to achieve the above object, the present inventors first ghosted the transfer current and transfer voltage and the process speed of the photoconductor in an image forming apparatus equipped with a photoconductor having an undercoat layer containing a metal oxide. The effect on the occurrence of selenium was investigated. As a result, in such an image forming apparatus, a ghost is easily generated when the transfer current or transfer voltage is increased, and the value obtained by dividing the transfer current or transfer voltage by the process speed of the photosensitive member is increased. Then, it discovered that it became easy to generate a ghost.

  As a result of further investigations, the present inventors have used a photoreceptor having an undercoat layer containing metal oxide particles treated with a silane coupling agent in place of the above photoreceptor, By setting the value obtained by dividing the current or transfer voltage by the process speed of the photoreceptor within a specific range, it is possible to achieve a high level balance between suppressing ghosting and improving transfer efficiency and image quality uniformity. The headline and the present invention were completed.

That is, the present invention provides a conductive support, a subbing layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and the subbing layer. An electrophotographic photoreceptor having a photosensitive layer;
Charging means for charging the electrophotographic photosensitive member;
Exposure means for irradiating a charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image on the electrophotographic photosensitive member;
Transfer means for transferring a toner image from an electrophotographic photosensitive member to a transfer medium, having a transfer member disposed opposite to the electrophotographic photosensitive member and being transferred between the electrophotographic photosensitive member and the transfer member Transfer in which a transfer current satisfying the condition expressed by the following expression (1) or a transfer voltage satisfying the condition expressed by the following expression (2) is supplied from the transfer member to the electrophotographic photosensitive member with the medium interposed. And an image forming apparatus (hereinafter referred to as “first image forming apparatus” for convenience).
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  According to the first image forming apparatus, an electrophotographic photosensitive member having an undercoat layer containing metal oxide particles treated with a silane coupling agent is used, and the process speed and transfer of the electrophotographic photosensitive member are transferred. By causing the transfer current or transfer voltage supplied from the transfer member of the means toward the electrophotographic photosensitive member to satisfy the condition represented by the above formula (1) or (2), the occurrence of ghosts can be suppressed. Improvement in transfer efficiency and improvement in image quality uniformity can be achieved at a high level in a balanced manner. As a result, good image quality can be stably obtained.

The present invention also provides a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and provided on the undercoat layer. An electrophotographic photoreceptor having a photosensitive layer;
Charging means for charging the electrophotographic photosensitive member;
Exposure means for irradiating a charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image on the electrophotographic photosensitive member;
An intermediate transfer type transfer unit that primarily transfers a toner image from an electrophotographic photosensitive member to an intermediate transfer member, and secondarily transfers the primary transfer image on the intermediate transfer member to an image output medium. The primary transfer member is disposed opposite to the photographic photosensitive member and in contact with the intermediate transfer member, and the intermediate transfer member is interposed between the electrophotographic photosensitive member and the primary transfer member. And a transfer means for supplying a transfer current satisfying the condition represented by the following expression (2) or a transfer voltage satisfying the condition represented by the following formula (2) from the primary transfer member to the electrophotographic photosensitive member. An apparatus (hereinafter referred to as “second image forming apparatus” for convenience) is provided.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  The second image forming apparatus includes a so-called intermediate transfer type transfer unit. In this case, an electrophotographic photosensitive member having an undercoat layer containing metal oxide particles treated with a silane coupling agent. The process speed of the electrophotographic photosensitive member and the transfer current or transfer voltage (that is, the primary transfer current or the primary transfer voltage) supplied from the primary transfer member of the transfer means to the electrophotographic photosensitive member. By satisfying the condition expressed by the formula (1) or (2), it is possible to achieve a high level balance between suppressing ghosting and improving transfer efficiency and image quality uniformity. As a result, good image quality can be stably obtained.

  In the present invention, the undercoat layer of the electrophotographic photosensitive member is a mixed solution composed of metal oxide particles treated with a silane coupling agent, a binder resin, a curing agent, and a solvent, and the mixed solution is cured. The coating liquid is obtained by adding resin particles having an average particle diameter of 1.0 μm or more to a mixed liquid prepared so that the transmittance with respect to light having a wavelength of 950 nm is 40% or less when a coating film having a thickness of 20 μm is formed. It is preferable that it is formed using. Since the mixed liquid prepared to satisfy the above conditions is in a state in which the metal oxide particles are sufficiently dispersed, the coating liquid for forming the undercoat layer obtained through the step of preparing the mixed liquid By forming the undercoat layer using, the conductive metal oxide is sufficiently dispersed in the binder resin obtained by curing the curable resin in the undercoat layer. As a result, a large number of conduction paths for electrons and holes (holes) are formed in the undercoat layer, charge transfer is facilitated, and an increase in residual potential in the photoreceptor can be suppressed. As a result, the ghost suppression effect in the image forming apparatus of the present invention can be further enhanced.

  In the present invention, the undercoat layer preferably further contains an electron accepting substance. By including an electron-accepting substance in the undercoat layer, the ghost suppression effect can be further enhanced, and additionally, effects such as improvement of sensitivity in an electrophotographic photosensitive member and reduction of fatigue during repeated use can be obtained. it can. In this case, the mass ratio of the electron-accepting substance to the metal oxide particles treated with the silane coupling agent (electron-accepting substance / metal oxide particles treated with the silane coupling agent) is 0.1 to 2. It is preferably 0.0% by mass.

  In the present invention, the surface potential of the electrophotographic photosensitive member charged by the charging means is preferably −800 to −600V. Thereby, sufficient charging uniformity can be obtained, which helps the ghost suppressing effect. If the surface potential exceeds -800 V, the influence of the dark decay of the photoreceptor potential increases, and image quality defects may occur during repeated use. On the other hand, when the surface potential is less than −600 V, the charging uniformity becomes insufficient, and density unevenness may occur.

The present invention also provides a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and provided on the undercoat layer. A charging step for charging an electrophotographic photosensitive member having a photosensitive layer;
An exposure step of irradiating a charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
A developing step of developing the electrostatic latent image with toner to form a toner image on the electrophotographic photoreceptor;
A transfer process for transferring a toner image from an electrophotographic photosensitive member to a transfer medium, wherein the transfer medium is interposed between the electrophotographic photosensitive member and a transfer member disposed opposite to the electrophotographic photosensitive member. A transfer step of supplying a transfer current satisfying the condition expressed by the following formula (1) or a transfer voltage satisfying the condition expressed by the following formula (2) from the transfer member toward the electrophotographic photosensitive member. An image forming method (hereinafter referred to as “first image forming method” for convenience) is provided.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current value (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  According to the first image forming method, an electrophotographic photosensitive member having an undercoat layer containing metal oxide particles treated with a silane coupling agent is used, the process speed of the electrophotographic photosensitive member, and the transfer By making the transfer current or transfer voltage supplied from the member toward the electrophotographic photosensitive member satisfy the condition represented by the above formula (1) or (2), suppression of the occurrence of ghost, transfer efficiency, and Improvement in image quality uniformity can be achieved at a high level and in a balanced manner, and as a result, good image quality can be stably obtained.

The present invention also provides a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and provided on the undercoat layer. A charging step for charging an electrophotographic photosensitive member having a photosensitive layer;
An exposure step of irradiating a charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
A developing step of developing the electrostatic latent image with toner to form a toner image on the electrophotographic photoreceptor;
A transfer process of an intermediate transfer method in which a toner image is primarily transferred from an electrophotographic photosensitive member to an intermediate transfer member, and a primary transfer image on the intermediate transfer member is secondarily transferred to an image output medium. A condition represented by the following formula (1) in a state where the intermediate transfer member is interposed between the primary transfer member disposed opposite to the electrophotographic photosensitive member via the transfer member and in contact with the intermediate transfer member. A transfer step of supplying a transfer current satisfying the above condition or a transfer voltage satisfying the condition represented by the following formula (2) from the primary transfer member toward the electrophotographic photosensitive member (hereinafter, referred to as an image forming method) For convenience, it is referred to as “second image forming method”).
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  The second image forming method is an image forming method including a transfer process of a so-called intermediate transfer method. In this case, an electron having an undercoat layer containing metal oxide particles treated with a silane coupling agent. While using a photographic photosensitive member, the process speed of the electrophotographic photosensitive member, and the transfer current or transfer voltage (that is, the primary transfer current or primary transfer voltage) supplied from the primary transfer member of the transfer means toward the electrophotographic photosensitive member, By satisfying the condition expressed by the above formula (1) or (2), it is possible to achieve a high level balance between suppressing ghosting and improving transfer efficiency and image quality uniformity. As a result, good image quality can be stably obtained.

  According to the present invention, there is provided an intermediate transfer type image forming apparatus and an image forming method capable of achieving a high level of well-balanced suppression of ghosting and improvement of transfer efficiency and image quality uniformity.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the first embodiment of the present invention. An image forming apparatus 210 shown in FIG. 1 includes an electrophotographic photosensitive member 100, a charging device 8 that charges the electrophotographic photosensitive member 100 by a contact charging method, a power source 9 connected to the charging device 8, and a charging device 8. An exposure device 10 that exposes the charged electrophotographic photosensitive member 100 to form an electrostatic latent image, and a developing device 11 that develops the electrostatic latent image formed by the exposure device 10 with toner to form a toner image. A transfer device 12 that transfers the toner image formed by the developing device 11 to a transfer medium; a cleaning device 13 that removes residual toner and the like adhering to the surface of the electrophotographic photosensitive member 100 after transfer; and after transfer and cleaning The static eliminator 14 for neutralizing the electrophotographic photosensitive member 100 and a fixing device 15 for fixing the toner image on the transfer medium. In another embodiment, the image forming apparatus may not include the static eliminator 14.

  Hereinafter, each element of the image forming apparatus 210 will be described in detail.

  FIG. 2 is a cross-sectional view of an essential part schematically showing a preferred example of the electrophotographic photoreceptor 100. The electrophotographic photoreceptor 100 shown in FIG. 2 is a function-separated photoreceptor in which the charge generation layer 1 and the charge transport layer 2 are separately provided in the photosensitive layer 6, and more specifically, the conductive support 3. The undercoat layer 4, the charge generation layer 1, the charge transport layer 2 and the protective layer 5 are stacked in this order. And the undercoat layer 4 is comprised including the metal oxide particle processed with the silane coupling agent.

  As the conductive support 3, aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel on a cylindrical substrate made of metal, such as aluminum, copper, iron, nickel, and glass and plastic. It is possible to use a known material in the form of a drum which is conductively treated by depositing a metal such as steel or barrel-indium, or depositing a conductive metal compound such as indium oxide or tin oxide, or laminating a metal foil. it can.

  When a metal pipe is used as the conductive support 3, the surface may be left as it is, or a process such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing is performed in advance. It may be.

  The undercoat layer 4 includes metal oxide particles treated with a silane coupling agent.

As the metal oxide particles, those having a powder resistance of about 10 ² to 10 ¹¹ Ω · cm are preferably used from the viewpoint of imparting an appropriate resistance to the undercoat layer 4 for leak resistance. Specifically, metal oxide particles such as tin oxide, titanium oxide, and zinc oxide are preferably used, and zinc oxide is particularly preferably used. Note that if the resistance value of the metal oxide particles is less than the lower limit value, the leak resistance tends to be insufficient, and if the resistance value exceeds the upper limit value, the residual potential tends to increase. As the metal oxide particles, those having a specific surface area of 10 m ² / g or more are preferably used. If the specific surface area of the metal oxide particles is less than 10 m ² / g, the chargeability tends to decrease.

  In addition, the silane coupling agent used for the surface treatment of the metal oxide particles is not particularly limited, but a silane coupling agent having an amino group is preferably used because it can impart a good blocking property to the undercoat layer.

  As the silane coupling agent having an amino group, any one can be used as long as it can obtain desired photoreceptor characteristics. Specifically, γ-aminopropyltriethoxysilane, N-β- ( Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and the like. Can be mentioned.

  In the present invention, a silane coupling agent having no amino group can also be used. Specific examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- Examples include (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane.

  In the present invention, two or more of the above silane coupling agents may be used in combination. In this case, it is preferable to use one or more of the silane coupling agents having an amino group.

  Any method can be used for the surface treatment of the metal oxide particles with a silane coupling agent as long as it is a known method. For example, a dry method or a wet method can be used.

  In the case of surface treatment by a dry method, stirring the metal oxide particles with a mixer having a large shearing force, the silane coupling agent is dropped alone or as a solution in an organic solvent, or dry air or nitrogen gas is added. It is processed uniformly by spraying together. The temperature at the time of dropping or spraying is preferably set to be equal to or lower than the boiling point of the solvent. When the temperature at the time of dripping or spraying exceeds the boiling point of the solvent, the solvent evaporates before being stirred uniformly, and the silane coupling agent is locally solidified, making uniform treatment difficult. The metal oxide particles thus surface-treated can be further baked at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  Further, in the case of surface treatment by a wet method, the metal oxide particles are stirred in a solvent, dispersed using an ultrasonic wave, a sand mill, an attritor, a ball mill, etc., and a silane coupling agent solution is added thereto and stirred. Then, it is processed uniformly by removing the solvent. Examples of the method for removing the solvent include distillation by distillation or distillation. The metal oxide particles thus surface-treated can be further baked at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. In the wet method, it is preferable to remove the water content of the metal oxide particles in advance before adding the silane coupling agent. Examples of the method for removing the water content include a method of removing metal oxide particles while stirring and heating in a solvent used for the surface treatment, a method of removing azeotropically with the solvent, and the like.

  The amount of the silane coupling agent relative to the metal oxide particles can be arbitrarily set as long as desired electrophotographic characteristics can be obtained. Further, two or more kinds of metal oxide particles having different surface treatments or different particle diameters can be used in combination.

  The undercoat layer 4 may further contain a binder resin. As the binder resin, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinyl imidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, conventionally used for the undercoat layer, Known binder resins such as gelatin, polyethylene, polyester, phenol resin, vinyl chloride-vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, and polyacrylic acid can be used. The content of the binder resin can be appropriately set as necessary.

  The undercoat layer 4 may further contain an electron accepting substance. Examples of the electron acceptor include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, and quinacridone pigments described in JP-A-47-30330, as well as cyano groups, nitro groups, and nitroso. And organic pigments such as bisazo pigments and phthalocyanine pigments having an electron-withdrawing substituent such as a group and a halogen atom. Among these, perylene pigments, bisbenzimidazole perylene pigments, and polycyclic quinone pigments are preferably used because they have high electron accepting properties and can be expected to have a higher ghost suppressing effect. These electron-accepting materials may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge acceptability.

  In addition, in order to prevent light reflection of the conductive support, resin particles having a particle size of 1.0 μm or more can be dispersed and used.

  The undercoat layer 4 can be formed using a metal oxide particle surface-treated with a silane coupling agent, and a coating solution obtained by mixing / dispersing the above-described components used as necessary in a solvent. The solvent is one that does not cause gelation or aggregation when mixed / dispersed with metal oxide oxide particles or further an electron-accepting pigment, and can dissolve the resin when a binder resin is used. Anything can be used. For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene Ordinary organic solvents such as toluene can be used alone or in admixture of two or more. As a mixing / dispersing method, a conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like can be applied.

  In addition, it is preferable that the coating liquid for undercoat layer formation is prepared so that the light transmittance of the coating film obtained may satisfy specific conditions. Specifically, the coating solution for forming the undercoat layer is applied on a glass plate so that the thickness after drying is 20 μm, and the coating film after drying is applied at a wavelength of 950 nm using a spectrophotometer. When the light transmittance is measured, it is preferable to appropriately select the type and content of each component so that the light transmittance is 40% or less. When the undercoat layer contains resin particles, the light transmittance is measured using the coating liquid before adding the resin particles, and the type and content of each component other than the resin particles are selected.

  The undercoat layer 4 can be formed by applying the coating solution for forming the undercoat layer thus prepared on the conductive support 3 and drying it. As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used. Further, the drying treatment is usually performed at a temperature at which the solvent can be evaporated and a film can be formed.

  The film thickness of the undercoat layer 4 is generally 0.1 to 40 μm, and preferably 5 to 40 μm from the viewpoint of the ghost suppression effect.

  The charge generation layer 1 includes a charge generation material and a binder resin.

  Examples of charge generation materials include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, organic pigments such as perylene pigments, pyrrolopyrrole pigments, and phthalocyanine pigments, and inorganic pigments such as trigonal selenium and zinc oxide. All known ones can be used. As the charge generation material, an inorganic pigment is preferable when a light source with an exposure wavelength of 380 nm to 500 nm is used, and a metal and a metal-free phthalocyanine pigment are preferable when a light source with an exposure wavelength of 700 nm to 800 nm is used. Among them, hydroxygallium phthalocyanine disclosed in JP-A-5-263007 and JP-A-5-279591, chlorogallium phthalocyanine disclosed in JP-A-5-98181, JP-A-5-140472 and special Dichlorotin phthalocyanine disclosed in Kaihei 5-140473 or titanyl phthalocyanine disclosed in JP-A-4-189873 and JP-A-5-43813 is particularly preferable.

  As the charge generation material, Bragg angles (2θ ± 0.2 °) with respect to CuKα characteristic X-rays of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25 Hydroxygallium phthalocyanine having diffraction peaks at .1 ° and 28.3 °, titanyl phthalocyanine having a strong diffraction peak at 27.2 ° with a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray, CuKα characteristic X Also preferred are chlorogallium phthalocyanines with strong diffraction peaks at 7.4 °, 16.6 °, 25.5 ° and 28.3 ° of the Bragg angle to the line (2θ ± 0.2 °).

  Furthermore, a pigment that has been subjected to a predetermined treatment may be used for the purpose of increasing the dispersion stability of the pigment, light sensitivity, or stabilizing the electrical characteristics.

  In addition, the binder resin for the charge generation layer 1 can be selected from a wide range of insulating resins, and selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. You can also Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resins such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be mentioned, but are not limited thereto. These binder resins can be used alone or in admixture of two or more. The blending ratio of the charge generation material and the binder resin (weight ratio) is preferably in the range of 10: 1 to 1:10.

  The charge generation layer 1 can be formed using a coating liquid in which a charge generation material and a binder resin are mixed / dispersed in a solvent. Solvents include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, and methylene. Ordinary organic solvents such as chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more. In addition, as a mixing / dispersing method, a usual method such as a ball mill dispersion method, an attritor dispersion method, a sand mill dispersion method, or the like can be used, but in this case, a condition that the crystal type does not change due to dispersion is required. The Further, at the time of this dispersion, it is effective to make the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

  The charge generation layer 1 can be formed by applying the coating solution for forming the charge generation layer thus prepared on the undercoat layer 4 and drying it. As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used. Further, the drying treatment is usually performed at a temperature at which the solvent can be evaporated and a film can be formed.

  The film thickness of the charge generation layer 1 is generally 0.1 to 5 μm, preferably 0.2 to 2.0 μm.

  The charge generation layer 14 is formed containing a charge transport material and a binder resin, or formed containing a polymer charge transport material.

Examples of the charge transport material used in the present invention include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl- Pyrazoline, pyrazoline derivatives such as 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (p-methylphenyl) aminyl-4- Aromatic tertiary amino compounds such as amine and dibenzylaniline, aromatic tertiary diamino compounds such as N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 3- (4 ′ -1,2,4-triazine derivatives such as -dimethylaminophenyl) -5,6-di- (4'-methoxyphenyl) -1,2,4-triazine, 4- Hydrazone derivatives such as ethylaminobenzaldehyde-1,1-diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, Hole transport such as α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof Substances, quinone compounds such as chloranil and broanthraquinone, tetraanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, xanthone Compounds, thiophene compounds, etc. Examples thereof include an electron transport material and a polymer having a group consisting of the above-described compounds in the main chain or side chain. These charge transport materials can be used alone or in combination of two or more. These charge transport materials can be used alone or in combination of two or more, but from the viewpoint of mobility, a structure represented by the following general formula (a-1), (a-2) or (a-3) A compound having is preferred.

In formula (a-1), R ¹ represents a hydrogen atom or a methyl group, a represents 1 or 2, and Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. When Ar ¹ and / or Ar ² is a substituted aryl group, the substituent is a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a carbon number. And a substituted amino group substituted with an alkyl group in the range of 1 to 3.

In formula (a-2), R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms. R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an alkyl group having 1 to 2 carbon atoms. A substituted amino group, a substituted or unsubstituted aryl group, or a group represented by —C (R ⁹ ) ═C (R ¹⁰ ) (R ¹¹ ) (R ⁹ , R ¹⁰ , R ¹¹ is a hydrogen atom; A substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group). p, q, r, and s are integers of 0-2.

In formula (a-3), R 12 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a substituted or unsubstituted aryl group, or —CH═CH—CH═C ( Ar) represents a group represented by ₂ (Ar represents a substituted or unsubstituted aryl group). R13, R14, R15 and R16 are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, A substituted or unsubstituted aryl group is shown.

  Examples of the binder resin used for the charge transport layer 2 include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly Polymeric charge transport materials such as -N-vinylcarbazole, polysilane, and polyester-based polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used. These binder resins can be used alone or in admixture of two or more. The blending ratio (weight ratio) between the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  A polymer charge transport material can also be used alone. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

  The charge transport layer 2 can further contain fluorine-based resin particles. Fluorine-based resin particles include tetrafluoroethylene resin, trifluorinated ethylene resin, hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin and copolymers thereof. It is desirable to appropriately select one type or two or more types from among them, and particularly preferred are tetrafluoroethylene resin and vinylidene fluoride resin. The average primary particle size of the fluororesin particles is preferably 0.05 to 1 μm, more preferably 0.1 to 0.5 μm. When the average primary particle size is less than 0.05 μm, aggregation during dispersion tends to proceed, and when it exceeds 1 μm, image quality defects are likely to occur. Moreover, 0.1-40 mass% is suitable for content of the fluorine resin particle in the charge transport layer 2 on the basis of the whole quantity of the charge transport layer 2, and 1-30 mass% is especially preferable. If the content is less than 1% by mass, the modification effect due to the dispersion of the fluororesin particles is not sufficient. On the other hand, if the content exceeds 40% by mass, the light transmission property decreases, and the residual potential tends to increase due to repeated use. .

  The charge transport layer 2 can be formed using a coating liquid in which the above components are mixed / dispersed in a solvent. Examples of the solvent include aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol and n-butanol, ketone solvents such as acetone, cyclohexanone and 2-butanone, methylene chloride and chloroform. Halogenated aliphatic hydrocarbon solvents such as ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol, and diethyl ether, or mixed solvents thereof can be used. In addition, as a mixing / dispersing method, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a high-pressure homogenizer, an ultrasonic disperser, a colloid mill, a collision type medialess disperser, a penetrating medialess disperser, or the like is used. be able to.

  In mixing / dispersing, it is preferable to control the temperature of the coating solution to 0 to 50 ° C. As a method of controlling the temperature of the coating solution, cool with water, cool with wind, cool with refrigerant, adjust the room temperature of the manufacturing process, warm with warm water, warm with hot air, warm with a heater, apply with a material that does not generate heat easily For example, a liquid production facility, a coating liquid production facility made of a material that easily dissipates heat, and a coating liquid production facility made of a material that easily stores heat can be used.

  It is also effective to add a small amount of a dispersion aid in order to improve the dispersion stability of the dispersion and to prevent aggregation during the formation of the coating film. Examples of the dispersion aid include fluorine-based surfactants, fluorine-based polymers, silicone-based polymers, and silicone oils.

  The charge transport layer 2 is formed by applying the coating liquid for forming the charge transport layer thus prepared on the charge generation layer 1 and drying it. As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.

  Additives such as antioxidants, light stabilizers, and heat stabilizers are added to the photosensitive layer to prevent photoconductor deterioration caused by ozone, oxidizing gas, or light or heat generated in the copying machine. can do. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine.

Further, at least one kind of electron accepting substance can be contained in the photosensitive layer for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use. Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Of these, benzene derivatives having electron-withdrawing substituents such as fluorenone-based, quinone-based, and -Cl, -CN, and -NO ₂ are particularly preferable.

  The protective layer 5 has a function of preventing chemical change of the charge transport layer during charging and further improving the mechanical strength of the photosensitive layer. The protective layer 5 is made of a curable resin, a cured resin film containing a charge transporting compound, a film formed by containing a conductive material in an appropriate binder resin, or the like.

  Any known resin can be used as the curable resin, and examples thereof include phenol resin, polyurethane resin, melamine resin, diallyl phthalate resin, and siloxane resin.

  As the charge transporting compound, a photofunctional organosilicon compound represented by the following general formula (b-1) is preferably used.

^{F [-D-Si (R 17} ) (3-m) Q m] n (b-1)

In formula (b-1), F represents an n-valent organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ¹⁷ represents a hydrogen atom, a substituted or non-substituted group. A substituted alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, m represents an integer of 1 to 3, and n represents an integer of 1 to 4.

  F in the general formula (b-1) is a unit having photoelectric characteristics, specifically, photocarrier transport characteristics, and a structure conventionally known as a charge transport material can be used as it is. Specific examples of F include compounds having hole transport properties such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, and hydrazone compounds. Examples of the skeleton include compound skeletons having electron transport properties such as quinone compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, and ethylene compounds.

Further, D in the general formula (b-1) represents a divalent group having flexibility. Specifically, an F site for imparting photoelectric characteristics and a three-dimensional inorganic glassy material. -Si (R ¹⁷ ) _{(3-m) that} binds to the network directly by bonding to the network Gives an appropriate flexibility to the inorganic glassy network that plays the role of linking to the Q _m site, and that is hard but brittle. This structure plays a role of improving the toughness of the film. The D, and _{specifically, -C n H2 n -, C} n H (2 n -2) -, - C n H (2n-4) - 2 divalent hydrocarbon group (here represented by, n represents an integer of 1 to 15.), —COO—, —S—, —O—, —CH ₂ —C ₆ H ₄ —, —N═CH—, — (C ₆ H ₄ ) — (C ₆ H ₄ ) —, and combinations thereof or those introduced with substituents.

In general formula (b-1), the group represented by —Si (R ¹⁷ ) _(3-m) Q _m is a substituted silicon group having a hydrolyzable group, and is three-dimensional Si— The structure plays a role of forming an O-Si bond, that is, an inorganic glassy network.

  In general formula (b-1), b is preferably 2 or more. When b is 2 or more, the photofunctional organosilicon compound represented by the general formula (b-1) contains two or more Si atoms, and an inorganic glassy network is easily formed. Strength is improved.

  Of the photofunctional organosilicon compounds represented by the general formula (b-1), compounds having a structure represented by the following general formula (b-2) are more preferable. The compound represented by the following general formula (b-2) is a compound having a hole transport ability, and is particularly preferable because it exhibits particularly excellent photoelectric characteristics and mechanical characteristics.

In general formula (b-2), Ar ^{3 to} Ar ⁶ each independently represents a substituted or unsubstituted aryl group, k represents 0 or 1, and Ar ⁷ represents substituted or unsubstituted when k is 0. When k is 1, it represents a substituted or unsubstituted arylene group. And 1 to 4 of Ar ^{3 to} Ar ⁷ have a bond bonded to a group represented by —Si (R ¹⁷ ) _(3-m) Q _m .

The substituted or unsubstituted aryl group represented by Ar ^{3 to} Ar ⁶ in the general formula (b-1) is specifically represented by the following general formulas (b-3) to (b-9). An aryl group is preferred.

In the formulas (b-3) to (b-9), R ¹⁸ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and A substituted phenyl group or an unsubstituted phenyl group, or an aralkyl group having 7 to 10 carbon atoms, wherein R ^{19 to} R ²¹ are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, respectively; Group, an alkoxy group having 1 to 4 carbon atoms, a phenyl group or an unsubstituted phenyl group substituted with them, an aralkyl group having 7 to 10 carbon atoms or a halogen atom, Ar represents a substituted or unsubstituted arylene group , X represents any of the structures represented by the group represented by —Si (R ¹⁷ ) _(3-m) Q _m , c and s each represent 0 or 1, and t represents an integer of 1 to 3. Indicates.

  In addition, as Ar in the aryl group represented by the above formula (b-9), an arylene group represented by the following formula (b-10) or (b-11) is preferable.

In the above formulas (b-10) and (b-11), R ²² and R ²³ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy having 1 to 4 carbon atoms. A phenyl group substituted with a group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom; t represents an integer of 1 to 3;

  Moreover, as Z 'in the aryl group represented by the formula (b-9), divalent groups represented by the following formulas (b-12) to (b-19) are preferable.

In formulas (b-18) and (b-19), R ²⁴ and R ²⁵ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkyl group having 1 to 4 carbon atoms. A phenyl group substituted with an alkoxy group, or an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom; W represents a divalent group; and q and r each represent 1 to 10 An integer is shown, and t is an integer of 1 to 3, respectively.

  In the above formulas (b-18) and (b-19), W represents a divalent group represented by the following formulas (b-20) to (b-28). In formula (b-27), u represents an integer of 0 to 3.

The specific structure of Ar ^{7 in} the general formula (b-2) is as follows. When k = 0, the structure of c = 1 in the specific structure of Ar ^{1 to} Ar ⁴ is when k = 1. A structure in which c = 0 in the specific structure of Ar ^{1 to} Ar ⁴ is given.

  The compound represented by general formula (b-1) may be used individually by 1 type, and may be used together 2 or more types.

  Moreover, you may use together the compound represented with the following general formula (III) for the purpose of further improving the mechanical strength of a cured film with the compound represented with general formula (b-1).

  In addition, in order to increase the strength of the protective layer 5, it is also preferable to use a compound having two or more silicon atoms as shown in the following general formula (c-1).

^{_{B (-Si (R 26) (}} 3-d) Q d) 2 (c-1)

In the above formula (c-1), B represents a divalent organic group, R ²⁶ represents a hydrogen atom, an alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and d represents 1 to 3. Indicates an integer. ]
The compound represented by the general formula (c-1) is a compound having a substituted silicon group having a group represented by -Si (R ²⁶ ) _(3-d) Q _d , that is, a hydrolyzable group. is there. The compound represented by the general formula (c-1) is a compound represented by the general formula (b-1) in which the group represented by -Si (R ²⁶ ) _(3-d) Q _d is represented by the general formula ( It reacts with the compound itself represented by c-1) to form Si—O—Si bonds to form a three-dimensional crosslinked cured film. Since the compound represented by the general formula (b-1) also has a group represented by —Si (R ¹⁷ ) _(3-m) Q _m , it is possible to form a cured film by itself. However, it is considered that when the compound represented by the general formula (c-1) is used in combination, the crosslinked structure of the cured film tends to be three-dimensional and has higher mechanical strength. In addition, the flexibility of the cured film can be improved.

  More specifically, as the compound represented by the general formula (c-1), the following compounds (c-2) to (c-6) can be mentioned as preferable ones.

In formulas (c-2) to (c-6), T ₁ and T ₂ each independently represent a divalent or trivalent hydrocarbon group, and A represents —Si (R ²⁶ ) _{( 3-d)} Q represents a group represented by _d . H, i, and j each independently represent an integer of 1 to 3, and are selected so that the number of A in the molecule is 2 or more.

  Specific examples of the compound represented by the general formula (c-1) are shown in Table 6 below, but the compound represented by the general formula (c-1) used in the present invention is limited to these specific examples. is not. In Table 6, Me represents a methyl group, Et represents an ethyl group, and i-Pr represents an isopropyl group.

  In addition to the compound represented by the general formula (b-1), another compound capable of crosslinking reaction may be used in combination. As such a compound, various silane coupling agents and commercially available silicon-based hard coat agents can be used.

  As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, And dimethyldimethoxysilane.

  As a commercially available hard coat agent, KP-85, CR-39, X-12-2208, X-40-9740, X-41-1007, KNS-5300, X-40-2239 (above, manufactured by Shin-Etsu Silicone Co., Ltd.) ), AY42-440, AY42-441, AY49-208 (above, manufactured by Toray Dow Corning).

  In addition, a fluorine-containing compound can be added to the protective layer 5 for the purpose of imparting surface lubricity. By improving the surface lubricity, the coefficient of friction with the cleaning member decreases, and the wear resistance can be improved. It also has the effect of preventing the adhesion of discharge products, developer, paper dust, etc. to the surface of the photoreceptor, which helps to improve the life of the photoreceptor.

  As the fluorine-containing compound, a fluorine atom-containing polymer such as polytetrafluoroethylene can be added as it is, or fine particles of these polymers can be added. Moreover, in the case of the cured film formed of the compound represented by the general formula (b-1), it is desirable to add a compound capable of reacting with alkoxysilane as the fluorine-containing compound and configure it as a part of the crosslinked film. . Examples of such fluorine atom-containing compounds include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl And triethoxysilane.

  The addition amount of the fluorine-containing compound is preferably 20% by mass or less. Exceeding this may cause a problem in the film formability of the crosslinked cured film.

  In addition, an antioxidant may be added for the purpose of imparting more excellent oxidation resistance to the protective layer 5. Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 15% by weight or less, and more preferably 10% by weight or less.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2- Dorokishi-5-methylbenzyl) -4-methylphenyl acrylate, 4,4'-butylidene bis (3-methyl -6-t-butylphenol), and the like.

  In addition, other additives used for forming a known coating film can be added to the protective layer 5, and known materials such as a leveling agent, an ultraviolet absorber, a light stabilizer, and a surfactant are used. be able to.

  The protective layer 5 can be formed by applying a coating solution containing the above various materials on the photosensitive layer and curing the coating film by heating. The curing reaction may be performed without a catalyst, but an appropriate catalyst may be used. Catalysts include acid catalysts such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, trifluoroacetic acid, bases such as ammonia and triethylamine, organic tin compounds such as dibutyltin diacetate, dibutyltin dioctoate, stannous oxalate, Examples thereof include organic titanium compounds such as tetra-n-butyl titanate and tetraisopropyl titanate, iron salts of organic carboxylic acids, manganese salts, cobalt salts, zinc salts, zirconium salts, and aluminum chelate compounds. Moreover, as a solvent used for a coating liquid, water, methanol, ethanol, n-propanol, i-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-acetate Usual organic solvents such as butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, dimethyl ether, dibutyl ether and the like can be used alone or in admixture of two or more. Moreover, as a coating method, usual methods, such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, can be used. The temperature at which the coating film is cured is not particularly limited as long as it does not affect the lower layer (such as the charge transport layer 2) of the protective layer 5, but is preferably set to room temperature to 200 ° C, particularly 100 to 160 ° C.

  The thickness of the protective layer 5 is 0.5 to 20 μm, preferably 2 to 10 μm.

  The thickness of the photosensitive layer of the electrophotographic photoreceptor 100 can be selected as appropriate, but in order to further increase the resolution, the total thickness of the functional layers above the charge generation layer 1 is preferably 50 μm or less, and 40 μm. The following is more preferable.

  The electrophotographic photoreceptor used in the present invention is not limited to the above configuration. For example, when the charge transport layer 2 has sufficient mechanical strength, the protective layer 5 may not be provided as shown in FIG. In the electrophotographic photosensitive member 100 shown in FIG. 2, the charge generating layer 1 and the charge transporting layer 2 are provided separately. The photosensitive layer of the electrophotographic photosensitive member is composed of a charge generating material and a charge transporting material. It may be a single-layer type photosensitive layer containing both.

  Next, returning to FIG. 1, elements other than the electrophotographic photoreceptor 100 will be described in detail.

  The charging device 8 makes a conductive member (charging roll) contact the surface of the photoconductor 100 to uniformly apply a voltage to the photoconductor to charge the surface of the photoconductor to a predetermined potential. The charging device provided in the image forming apparatus of the present invention may be a non-contact type using corotron or scorotron. However, the electrophotographic photoreceptor of the present invention is excellent in mechanical strength. When contact charging with high stress is used, particularly excellent durability is exhibited as compared with a conventional electrophotographic photosensitive member.

  As the conductive member, a member provided with an elastic layer, a resistance layer, a protective layer and the like on the outer peripheral surface of the core material is preferably used. The shape of the conductive member may be any of a brush shape, a blade shape, a pin electrode shape, a roller shape, and the like.

  As the material of the core material, a conductive material, for example, iron, copper, brass, stainless steel, aluminum, nickel, or the like is used. Also, a resin molded product in which conductive particles or the like are dispersed can be used.

As the material of the elastic layer, a material having conductivity or semiconductivity, for example, a material in which conductive particles or semiconducting particles are dispersed in a rubber material can be used. As the rubber material, EPDM, polybutadiene, natural rubber, polyisobutylene, SBR, CR, NBR, silicone rubber, urethane rubber, epichlorohydrin rubber, SBS, thermoplastic elastomer, norbornene rubber, fluorosilicone rubber, ethylene oxide rubber and the like are used. Examples of the conductive particles or semiconductive particles include carbon black, zinc, aluminum, copper, iron, nickel, chromium, titanium and other metals, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ — Metal oxides such as SnO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , Sb ₂ O ₃ , In ₂ O ₃ , ZnO, or MgO can be used. These materials can be used individually by 1 type or in mixture of 2 or more types.

  As the material of the resistance layer and the protective layer, conductive particles or semiconductive particles are dispersed in a binder resin, and the resistance is controlled. As binder resin, acrylic resin, cellulose resin, polyamide resin, methoxymethylated nylon, ethoxymethylated nylon, polyurethane resin, polycarbonate resin, polyester resin, polyethylene resin, polyvinyl resin, polyarylate resin, polythiophene resin, PFA, FEP or A polyolefin resin such as PET or a styrene-butadiene resin is used. As the conductive particles or semiconductive particles, carbon black, metal, or metal oxide similar to the elastic layer is used. Further, if necessary, an antioxidant such as hindered phenol and hindered amine, a filler such as clay and kaolin, and a lubricant such as silicone oil can be added. As a means for forming these layers, a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, or the like can be used.

  When the photosensitive member 100 is charged using these conductive members, a voltage is applied to the conductive member. The applied voltage may be either a DC voltage or a DC voltage superimposed with an AC voltage. In addition to the charging roll shown in this embodiment, charging by a contact charging method may be performed using a charging brush, a charging film, a charging tube, or the like. Moreover, you may charge by the non-contact system using a corotron or a scorotron.

  As the exposure apparatus 10, an optical system apparatus that can expose a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter on the surface of the electrophotographic photosensitive member 100 in a desired image-like manner can be used. Among these, when an exposure apparatus capable of exposing non-interference light is used, interference fringes between the conductive substrate of the electrophotographic photoreceptor 100 and the photosensitive layer can be prevented.

  As the developing device 11, for example, a general developing device that performs development by bringing a magnetic or non-magnetic one-component developer or a two-component developer into contact or non-contact with each other can be used. Such a developing device is not particularly limited as long as it has the functions described above, and can be appropriately selected according to the purpose. For example, a known developing device having a function of attaching the one-component developer or the two-component developer to the photoreceptor 100 using a brush, a roller, or the like can be used.

The transfer device 12 is expressed by a transfer current that satisfies the condition expressed by the following formula (1) or the following formula (2) in a state where the transfer medium is interposed between the electrophotographic photosensitive member 100 and the transfer member. A transfer voltage satisfying the above condition is supplied from the transfer member to the electrophotographic photosensitive member.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  Examples of the transfer device 12 include a roller-type contact charging member, a contact-type transfer charger using a belt, a film, a rubber blade, or the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, or the like. .

Incidentally, the process speed _{S p} of the electrophotographic photosensitive member 100, each of the transfer current I and the transfer voltage V, is not particularly limited as long as it satisfies the above formula (1) or (2), _{S p} is preferably 30~300mm / Sec, more preferably 50 to 250 mm / sec. I is preferably 5 to 50 μA, more preferably 20 to 40 μA. Moreover, V becomes like this. Preferably it is 800-4000V, More preferably, it is 1500-3000V.

  The cleaning device 13 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process, and the electrophotographic photosensitive member cleaned by this is repeatedly used for the image forming process described above. . As the cleaning device 13, methods such as brush cleaning and roll cleaning can be used in addition to those using the illustrated cleaning blade. Among these, it is preferable to use the cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  According to the first embodiment, the electrophotographic photoreceptor 100 having the undercoat layer containing the metal oxide particles treated with the silane coupling agent is used, the process speed of the electrophotographic photoreceptor 100, and the transfer device By suppressing the transfer current or transfer voltage supplied from the 12 transfer members toward the electrophotographic photosensitive member to satisfy the condition expressed by the above formula (1) or (2), the generation of ghosts can be suppressed. Improvement in transfer efficiency and improvement in image quality uniformity can be achieved at a high level in a balanced manner. As a result, good image quality can be stably obtained.

  FIG. 4 is a schematic configuration diagram showing an image forming apparatus according to the second embodiment of the present invention. The image forming apparatus shown in FIG. 4 is an image forming apparatus that forms a color image by a tandem method. In the housing 400, four electrophotographic photoreceptors 100a to 100d (for example, the electrophotographic photoreceptor 100a is yellow and the electrophotographic photoreceptor is formed. 100b can form an image of magenta, the electrophotographic photosensitive member 100c is cyan, and the electrophotographic photosensitive member 100d is black, respectively.) Are arranged in parallel with each other along the intermediate transfer belt 409. The electrophotographic photoconductors 100a to 100d are not particularly limited as long as they are each a photoconductor provided with an undercoat layer containing metal oxide particles treated with a silane coupling agent. For example, the configuration shown in FIG. be able to.

  Each of the electrophotographic photoreceptors 100a to 100d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can be supplied with toner of four colors of black, yellow, magenta and cyan accommodated in toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively intermediate transfer belts. 409 is in contact with the electrophotographic photoreceptors 100a to 100d.

  Further, a laser light source (exposure means) 403 is arranged at a predetermined position in the housing 400, and the surfaces of the electrophotographic photoreceptors 100a to 100d after charging are irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photoreceptors 100a to 100d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

Here, in the present embodiment, the primary satisfying the condition represented by the following formula (1) with the intermediate transfer belt 409 interposed between the electrophotographic photoreceptors 100a to 100d and the primary transfer rolls 410a to 410d. A primary transfer voltage that satisfies the transfer current or the condition expressed by the following formula (2) is supplied from the primary transfer rolls 410a to 410d toward the electrophotographic photoreceptors 100a to 100d.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. Also good. In the case of a belt shape, a conventionally known resin can be used as the resin material used as the base material of the intermediate transfer member. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Resin materials such as polyether ether ketone and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used.

  As an elastic material, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, silicone rubber, or the like can be used, or a material obtained by blending two or more kinds can be used. If necessary, a conductive agent imparting electronic conductivity or a conductive agent having ionic conductivity is added to the resin material and elastic material used for these base materials in combination of one kind or two or more kinds. Among these, it is preferable to use a polyimide resin in which a conductive agent is dispersed from the viewpoint of excellent mechanical strength. As the conductive agent, a conductive polymer such as carbon black, metal oxide, or polyaniline can be used. When a belt-shaped configuration such as the intermediate transfer belt 409 is adopted as the intermediate transfer member, generally the thickness of the belt is preferably 50 to 500 μm, more preferably 60 to 150 μm, but the hardness of the material It can be selected as appropriate according to the conditions.

  For example, a belt made of a polyimide resin in which a conductive agent is dispersed is 5 to 20 mass as a conductive agent in a polyamic acid solution which is a polyimide precursor, as described in JP-A-63-311263. % Of carbon black is dispersed, the dispersion is cast on a metal drum and dried, and then the film peeled off from the drum is stretched at a high temperature to form a polyimide film. It can be manufactured by forming a belt.

  The film molding is generally performed by injecting a polyamic acid solution film-forming stock solution in which a conductive agent is dispersed into a cylindrical mold and, for example, heating at 100 to 200 ° C. at a rotational speed of 500 to 2000 rpm. The film was formed into a film by a centrifugal molding method while rotating, and then the obtained film was demolded in a semi-cured state and covered with an iron core, followed by a polyimide reaction (polyamic acid at a high temperature of 300 ° C. or higher. Can be carried out by carrying out a main ring curing reaction. In addition, the stock solution is cast on a metal sheet to a uniform thickness and heated to 100 to 200 ° C. to remove most of the solvent in the same manner as described above, and then gradually raised to a high temperature of 300 ° C. or higher. There is also a method of forming a polyimide film. Further, the intermediate transfer member may have a surface layer.

  When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  The transfer medium according to the present invention is not particularly limited as long as it is a medium that transfers a toner image formed on an electrophotographic photosensitive member. For example, when transferring directly from an electrophotographic photosensitive member to a transfer medium such as paper, paper or the like is the transfer medium. When an intermediate transfer member is used, the intermediate transfer member is a transfer medium.

  According to the second embodiment, the electrophotographic photoreceptors 100a to 100d having the undercoat layer containing the metal oxide particles treated with the silane coupling agent are used, and the processes of the electrophotographic photoreceptors 100a to 100d are used. The speed and the transfer current or transfer voltage (that is, the primary transfer current or the primary transfer voltage) supplied from the primary transfer rolls 410a to 410d to the electrophotographic photoreceptors 100a to 100d respectively are expressed by the above formula (1) or (2 In the case of forming an image by the intermediate transfer method, it is possible to achieve a high level balance between suppressing ghosting and improving transfer efficiency and image quality uniformity. As a result, good image quality can be stably obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Production of electrophotographic photosensitive member]
(Preparation of photoconductor A)
First, a cylindrical aluminum substrate having a diameter of 30 mm, a length of 404 mm, and a thickness of 1 mm was prepared as a conductive support.

Next, 100 parts by mass of zinc oxide (average particle size 70 nm, prototype manufactured by Teica, specific surface area value 15 m ² / g) is stirred and mixed with 500 parts by mass of toluene, and a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.25 parts by mass were added and the mixture was further stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure, and baking was performed at 120 ° C. for 3 hours to obtain a zinc oxide pigment surface-treated with a silane coupling agent.

  60 parts by mass of the zinc oxide thus surface-treated is 0.3 parts by mass of alizarin (manufactured by Sigma-Aldrich Japan) and 13.5 parts by mass of a curing agent (blocked isocyanate Sumidur 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.). And 15 parts by mass of butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) and dissolved in 85 parts by mass of methyl ethyl ketone. 38 parts by mass of this solution and 25 parts by mass of methyl ethyl ketone were mixed, and dispersion treatment was performed with a sand mill using 1 mmφ glass beads. At this time, the dispersion is appropriately sampled, and the obtained sampling solution is applied on a glass plate so that the thickness after drying is 20 μm. After drying, the light of the film at a wavelength of 950 nm is measured using a spectrophotometer. The transmittance was measured. The dispersion was terminated when the light transmittance at this time reached 40%. To the dispersion thus obtained, 0.005 parts by mass of dioctyltin dilaurate as a catalyst and 4.0 parts by mass of silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone) are added to form an undercoat layer. A coating solution was obtained. This coating solution was applied to the outer peripheral surface of the aluminum substrate by a dip coating method, followed by drying and curing at 190 ° C. for 24 minutes to obtain an undercoat layer having a thickness of 25 μm.

  Next, 15 parts by mass of chlorogallium phthalocyanine as a charge generation material, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Union Carbide) as a binder resin, and 200 parts by mass of n-butyl acetate The mixture consisting of was dispersed for 4 hours in a sand mill using glass beads of 1 mmφ. 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added to the obtained dispersion and stirred to obtain a charge generation layer forming coating solution. The obtained coating solution was dip-coated on the undercoat layer and dried at room temperature to form a charge generation layer having a thickness of 0.2 μm.

  Furthermore, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine and bisphenol Z polycarbonate resin (viscosity average molecular weight: 40 , 000) 6 parts by mass was dissolved in 80 parts by mass of tetrahydrofuran to obtain a coating solution for forming a charge transport layer. The obtained coating solution is formed on the charge generation layer and dried at 135 ° C. for 40 minutes to form a charge transport layer having a thickness of 32 μm. The electrophotographic photosensitive member having the laminated structure shown in FIG. Got. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor A”.

(Preparation of photoconductor B)
An electrophotographic photosensitive member was produced in the same manner as the photosensitive member A except that the dispersion treatment was terminated when the coating film had a light transmittance of 15% when the coating solution for forming the undercoat layer was prepared. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor B”.

(Preparation of photoconductor C)
An electrophotographic photosensitive member was produced in the same manner as the photosensitive member A except that the dispersion treatment was terminated when the coating film had a light transmittance of 80% when the coating solution for forming the undercoat layer was prepared. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor C”.

(Preparation of photoconductor D)
An electrophotographic photosensitive member was produced in the same manner as the photosensitive member A, except that alizarin was not added when preparing the coating solution for forming the undercoat layer. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor D”.

(Preparation of photoconductor E)
100 parts by mass of tin oxide (S1, manufactured by Mitsubishi Materials Corporation) was mixed with 500 parts by mass of toluene, 1.25 parts by mass of a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours.

  An electrophotographic photosensitive member was produced in the same manner as the photosensitive member A except that the surface-treated tin oxide was used in place of the surface-treated zinc oxide to form an undercoat layer. . Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor E”.

(Preparation of photoconductor F)
An electrophotographic photosensitive member was produced in the same manner as the photosensitive member A except that the undercoat layer was formed using zinc oxide that was not surface-treated with a silane coupling agent. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor F”.

(Preparation of photoconductor G)
An electrophotographic photosensitive member was produced in the same manner as the photosensitive member D except that an undercoat layer was formed using zinc oxide that was not surface-treated with a silane coupling agent. Hereinafter, the obtained electrophotographic photoreceptor is referred to as “photoreceptor G”.

[Examples 1 to 15 and Comparative Examples 1 to 20]
In Examples 1 to 15 and Comparative Examples 1 to 20, the photosensitive drums A to G are used, respectively, and the process speed Sp and the primary transfer current I are as shown in Tables 7 to 13 as shown in FIG. An image forming apparatus having a configuration was produced. The elements other than the electrophotographic photosensitive member were the same as those of DocuCenter Color a450 manufactured by Fuji Xerox Co., Ltd.

  Next, 50000 print tests were performed using each image forming apparatus to evaluate transferability and ghost suppression. The obtained results are shown in Tables 7-13. In the “transferability” column, A means transfer efficiency of 80% or more, B means transfer efficiency of 75 to 80%, C means transfer efficiency of 70 to 75%, and D means transfer efficiency of 70% or less. In the “ghost suppression” column, A indicates that no ghost has occurred, B indicates that ghost has hardly occurred, C indicates that ghost has occurred, and D indicates that ghost has occurred remarkably. Means each.

[Examples 16 to 30, Comparative Examples 21 to 40]
In Examples 16 to 30 and Comparative Examples 21 to 40, the photoreceptor speeds A to G are used, and the process speed Sp and the primary transfer voltage V are as shown in Tables 14 to 20 as shown in FIG. An image forming apparatus having a configuration was produced. The elements other than the electrophotographic photosensitive member were the same as those of DocuCenter Color a450 manufactured by Fuji Xerox Co., Ltd.

Next, a print test of 50,000 sheets was performed using each image forming apparatus to evaluate transferability and ghost suppression. The obtained result is shown to Tables 14-20. In the "Transferability" column of the table, A means transfer efficiency of 80% or more, B means transfer efficiency of 75 to 80%, C means transfer efficiency of 70 to 75%, and D means transfer efficiency of 70% or less. . In the “ghost suppression” column,
A means that no ghost has occurred, B means that ghost has hardly occurred, C means that ghost has occurred, and D means that ghost has occurred remarkably.

1 is a schematic configuration diagram illustrating a preferred embodiment of an image forming apparatus of the present invention. 1 is a schematic cross-sectional view showing a preferred example of an electrophotographic photoreceptor according to the present invention. FIG. 6 is a schematic cross-sectional view showing another preferred example of the electrophotographic photosensitive member according to the present invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Charge generation layer, 2 ... Charge transport layer, 3 ... Conductive support body, 4 ... Undercoat layer, 5 ... Protective layer, 6 ... Photosensitive layer, 8 ... Charging apparatus, 9 ... Power supply, 10 ... Exposure apparatus, 11 DESCRIPTION OF SYMBOLS Development apparatus, 12 Transfer apparatus, 13 Cleaning apparatus, 14 Static eliminator, 15 Image fixing apparatus, 100 Electrophotographic photosensitive member, 210, 220 Image forming apparatus

Claims (6)

Electrons having a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and a photosensitive layer provided on the undercoat layer A photoconductor,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for irradiating the charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image on the electrophotographic photosensitive member;
Transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer medium, comprising: a transfer member disposed opposite to the electrophotographic photosensitive member, the electrophotographic photosensitive member and the transfer member; In the state in which the transfer medium is interposed between the transfer member and the transfer voltage satisfying the condition represented by the following formula (1) or the transfer voltage satisfying the condition represented by the following formula (2), An image forming apparatus comprising: a transfer unit that supplies the photosensitive member to the photosensitive member.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ] Electrons having a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and a photosensitive layer provided on the undercoat layer A photoconductor,
Charging means for charging the electrophotographic photoreceptor;
Exposure means for irradiating the charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image on the electrophotographic photosensitive member;
An intermediate transfer type transfer means for primary transfer of the toner image from the electrophotographic photosensitive member to an intermediate transfer member and secondary transfer of the primary transfer image on the intermediate transfer member to an image output medium, the intermediate transfer member A primary transfer member disposed opposite to the intermediate transfer member and in contact with the intermediate transfer member, and the intermediate transfer member is interposed between the electrophotographic photosensitive member and the primary transfer member In such a state, the transfer current that satisfies the condition represented by the following expression (1) or the transfer voltage that satisfies the condition represented by the following expression (2) is supplied from the primary transfer member to the electrophotographic photosensitive member. And an image forming apparatus.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]   The undercoat layer is a mixed liquid composed of the metal oxide particles treated with the silane coupling agent, a binder resin, a curing agent, and a solvent, and the mixed liquid is cured to have a coating thickness of 20 μm. What was formed using a coating liquid in which resin particles having an average particle diameter of 1.0 μm or more were added to a mixed liquid prepared so that the transmittance for light having a wavelength of 950 nm was 40% or less when the film was formed The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 1, wherein the undercoat layer further contains an electron accepting substance. Electrons having a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and a photosensitive layer provided on the undercoat layer A charging step for charging the photographic photoreceptor;
An exposure step of irradiating the charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
A developing step of developing the electrostatic latent image with toner to form a toner image on the electrophotographic photoreceptor;
A transfer step of transferring the toner image from the electrophotographic photosensitive member to a transfer medium, wherein the toner image is transferred between the electrophotographic photosensitive member and a transfer member disposed opposite to the electrophotographic photosensitive member; With the medium interposed, a transfer current that satisfies the condition expressed by the following expression (1) or a transfer voltage that satisfies the condition expressed by the following expression (2) is supplied from the transfer member to the electrophotographic photosensitive member. An image forming method.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current value (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ] Electrons having a conductive support, an undercoat layer provided on the conductive support and containing metal oxide particles treated with a silane coupling agent, and a photosensitive layer provided on the undercoat layer A charging step for charging the photographic photoreceptor;
An exposure step of irradiating the charged electrophotographic photosensitive member with exposure light to form an electrostatic latent image on the electrophotographic photosensitive member;
A developing step of developing the electrostatic latent image with toner to form a toner image on the electrophotographic photoreceptor;
A transfer step of an intermediate transfer method in which the toner image is primarily transferred from the electrophotographic photosensitive member to an intermediate transfer member, and the primary transfer image on the intermediate transfer member is secondarily transferred to an image output medium. In the state in which the intermediate transfer member is interposed between the intermediate transfer member and the primary transfer member disposed in contact with the intermediate transfer member and facing the electrophotographic photosensitive member via the intermediate transfer member, the following formula A transfer step of supplying a transfer current satisfying the condition represented by (1) or a transfer voltage satisfying the condition represented by the following formula (2) from the primary transfer member toward the electrophotographic photosensitive member. An image forming method.
0.16 ≦ I / S _p ≦ 0.20 (1)
Wherein, I represents the transfer current (unit: .mu.A) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]
15.5 ≦ V / S _p ≦ 20.5 (2)
Wherein, V is a transfer voltage (unit: V) indicates, _{S p} is the process speed of the electrophotographic photosensitive member (unit: mm / sec) showing the. ]

Images