JP2005249964A - Image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and a process cartridge which suppress fog or black spots in an output image or generation of image memory even when an image is formed by switching a plurality of modes. <P>SOLUTION: In the image forming apparatus carrying out charging, exposing, developing and transferring while moving the outer peripheral face of an electrophotographic photoreceptor in a predetermined direction, the apparatus is equipped with a controlling means to control the moving speed of the outer peripheral face of the photoreceptor so as to vary the time required from charging to developing. The photosensitive layer of the electrophotographic photoreceptor contains gallium phthalocyanine, wherein the maximum primary particle size of the gallium phthalocyanine is specified to ≤0.3 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and a process cartridge.

  The electrophotographic system is used in image forming apparatuses such as copying machines and laser beam printers because high-speed and high-quality printing is possible. In addition, as a color image forming apparatus, each color forming unit has black (K), yellow (Y), magenta (M), and cyan (C), and each image forming unit has a different color. Various so-called tandem-type color image forming apparatuses for transferring an image onto a transfer material or an intermediate transfer member to form a color image have been proposed and commercialized.

In such an image forming apparatus, recently, in order to achieve both high image quality and high efficiency, a technique for switching an image forming mode in accordance with the type of an image or a medium to be transferred has been studied ( For example, see Patent Document 1). For example, in the case of forming a monochrome image, it is only necessary to form an image using only black toner, and it is considered that the process speed in that case can be increased as compared with the formation of a color image. Regardless of whether the image forming apparatus is a color machine or a monochrome machine, if the image transfer material is cardboard or an OHP sheet, the time required for image formation can be set longer than usual. It is believed that quality image formation can be performed.
JP 2003-241511 A

  However, in practice, when image formation is performed by switching between a plurality of modes as described above, sufficient image quality cannot often be obtained. That is, when the image forming mode is switched, the time required from charging to development changes, but an electrophotographic photosensitive member that can cope with such a change in use conditions has not yet been sufficiently studied. For this reason, when the image forming mode is switched in the conventional image forming apparatus, there are problems that fog and black spots tend to occur frequently in the output image depending on the mode, and an image memory is likely to be generated.

  The present invention has been made in view of such circumstances, and can suppress the occurrence of fog and black spots and the generation of image memory in an output image even when image formation is performed by switching a plurality of modes. An object is to provide an image forming apparatus and a process cartridge.

  In order to solve the above problems, an image forming apparatus of the present invention includes an electrophotographic photosensitive member, a charging unit, an exposure unit, a developing unit, and a transfer unit, and is charged while moving the outer peripheral surface of the electrophotographic photosensitive member in a predetermined direction. An image forming apparatus that performs exposure, development, and transfer, and further includes a control unit that controls a moving speed of the outer peripheral surface of the electrophotographic photosensitive member so that a time required from charging to development is variable. The photoreceptor has a conductive support and a photosensitive layer containing gallium phthalocyanine formed on the conductive support, and the maximum primary particle diameter of gallium phthalocyanine contained in the photosensitive layer is 0.3 μm or less. It is characterized by being.

  According to the image forming apparatus of the present invention, gallium phthalocyanine is contained in a photosensitive layer of an electrophotographic photoreceptor together with a binder resin, and the maximum primary particle diameter of the gallium phthalocyanine is set to 0.3 μm or less. The electrophotographic characteristics of the photoreceptor can be sufficiently enhanced, and the use conditions can be widened. Therefore, even if image formation is performed while changing the time required from charging to development, it is possible to sufficiently suppress the occurrence of fog and black spots in the output image and the generation of image memory.

  Although the reason why the above-described effect can be obtained by the present invention is not necessarily clear, the present inventors infer as follows.

  First, the reason why the above problem has occurred in the conventional image forming apparatus will be described. In the case of a charge generating material used in a conventional electrophotographic photosensitive member, there is a problem that it tends to include coarse particles or aggregates of particles derived from the crystal structure and manufacturing process, or a problem that the shape of the particles tends to be non-uniform. doing. For example, when the charge generation material contains coarse particles, the coarse particles are not completely covered with the binder resin and are exposed even if dispersed in the binder resin. The exposed coarse particles of the charge generating material form charge injection sites, which serve as points for receiving charge injection from the lower layer (conductive support or undercoat layer) of the photosensitive layer, such as fog and black spots. Cause. In addition, when the photosensitive layer of the electrophotographic photosensitive member is a function separation type photosensitive member in which a charge transport layer and a charge generation layer are laminated, coarse particles of the charge generation material become a point for injecting charges into the upper layer of the charge generation layer, and the fog is generated. And cause sunspots. Furthermore, even when an undercoat layer is provided between the conductive support and the photosensitive layer, if the resistance of the undercoat layer is low, charge injection into the charge injection site of the charge generation layer becomes intense and fogging occurs. Cause it to worsen.

  Further, in the conventional electrophotographic photosensitive member, the free carrier included in the charge generating material sufficiently moves to the surface of the electrophotographic photosensitive member when the time required from charging to development is short (when the process speed is high). It cannot be fogged or black spots, but when the time required from charging to development is short (when the process speed is slow), it can move to the surface of the photoconductor, thereby canceling the surface charge. It is thought that fogging and sunspots occur. This free carrier is considered to be generated by a fine crystal structure on the surface of the charge generation material or a slight distortion inside the crystal.

  On the other hand, in the present invention, as the charge generation material, gallium phthalocyanine whose primary particle diameter satisfies the above-described conditions is contained in the photosensitive layer of the electrophotographic photoreceptor, so that the charge generation material is highly miniaturized and uniformized. It is considered to be achieved at the standard. Therefore, if the time required from charging to development is increased, the generation of fog and black spots in the output image and the generation of image memory can be improved, and an undercoat layer is provided from the viewpoint of leak prevention. In this case, it is considered that the problem that fog and black spots are deteriorated due to the resistance characteristics of the undercoat layer can be improved.

The primary particle diameter of gallium phthalocyanine as referred to in the present invention can be measured according to the following procedures (i) to (iii) using a transmission electron microscope (TEM).
(I) Prepare a sample mesh for TEM to which a thin resin layer has been applied in advance and further reinforced by carbon deposition.
(Ii) Disperse gallium phthalocyanine in ethanol, drop the dispersion onto the sample mesh and dry naturally.
(Iii) The dropping part on the sample mesh is observed at several to several tens of fields suitable for TEM observation at a magnification of 700 times.
(Iv) Wide-field observation at a magnification of 6,000 and narrow-field observation at a magnification of 30,000 are performed for each of five visual fields.

  The “field suitable for TEM observation” in the above (ii) means a field representative of the entire sample, but it is preferable that the aggregate is too thick so that there is no portion through which the electron beam does not pass. A field of view in which the sample occupies most of the observation surface (70 to 100%) in the field of view (low magnification) is desirable.

  The image forming apparatus of the present invention includes a plurality of image forming units each including an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit, and the outer peripheral surface of the electrophotographic photosensitive member is set in a predetermined direction in each of the image forming units. A color image forming apparatus that performs charging, exposure, development, and transfer while moving to the position of the outer peripheral surface of the electrophotographic photoreceptor so that the time required from charging to development is variable in each of the image forming units. The apparatus further comprises a control means for controlling the moving speed, and each of the electrophotographic photoreceptors has a photosensitive layer containing gallium phthalocyanine, and the maximum primary particle diameter of gallium phthalocyanine contained in the photosensitive layer is 0.3 μm or less. This may be a feature.

  As described above, in a color image forming apparatus including a plurality of image forming units, gallium phthalocyanine is contained in the photosensitive layer of the electrophotographic photosensitive member of each image forming unit together with the binder resin, and the maximum primary particle diameter of the gallium phthalocyanine is increased. By setting the value to 0.3 μm or less, it is possible to sufficiently suppress the occurrence of fog and black spots and image memory in the output image even when image formation is performed while changing the time required from charging to development. It becomes. Therefore, the above color image forming apparatus can realize both high image quality and high efficiency in color image formation.

  The control means provided in the image forming apparatus of the present invention controls the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so as to satisfy the conditions represented by the following formulas (1) and (2), and the normal mode, the low speed mode, It is preferable that a plurality of control modes including the high speed mode can be switched. As a result, it is possible to effectively realize high image quality during color image formation or use of thick paper or an OHP sheet and high efficiency during monochrome image formation.

T _low ≧ (1/3) T (1)
T _high ≦ 3T (2)
(In the formula, T represents the time required from charging to developing when performing the electrophotographic process in the normal mode, T _low represents the time required from charging to developing when performing the electrophotographic process in the _low speed mode, and T _high indicates the time required from charging to development when the electrophotographic process is performed in the _high- speed mode.)
The gallium phthalocyanine according to the present invention is preferably hydroxygallium phthalocyanine.

As the hydroxygallium phthalocyanine, those having a maximum absorption in the range of 600 to 900 nm of spectral absorption spectrum at 810 to 839 nm are preferable. Further, the specific surface area value of the hydroxygallium phthalocyanine according to the BET method is more preferably 45 m ² / g or more. Furthermore, it is preferable that the hydroxygallium phthalocyanine has diffraction peaks at least at a Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.3 ° with respect to the CuKα characteristic X-ray.

  Moreover, as chlorogallium phthalocyanine, what has absorption in the 770-790 nm maximum peak in the range of 600-900 nm of a spectral absorption spectrum is preferable.

  The gallium phthalocyanine according to the present invention can be suitably obtained by crystal conversion by a wet pulverization method.

  Moreover, it is preferable that the electrophotographic photosensitive member provided in the image forming apparatus of the present invention further has an undercoat layer formed between the conductive support and the photosensitive layer. The undercoat layer preferably contains inorganic fine particles.

  Further, the image forming apparatus of the present invention may be a contact charging device in which the charging unit contacts the electrophotographic photosensitive member to charge the electrophotographic photosensitive member.

  Further, in the image forming apparatus of the present invention, the transfer unit employs an intermediate transfer method in which the toner image formed on the outer peripheral surface of the electrophotographic photosensitive member is transferred to the transfer medium via the intermediate transfer member. It is good also as having the feature.

  The process cartridge of the present invention includes an electrophotographic photosensitive member and at least one selected from a charging unit, a developing unit, a transfer unit, and a cleaning unit, and moves the outer peripheral surface of the electrophotographic photosensitive member in a predetermined direction. A process cartridge that can be attached to and detached from an image forming apparatus that performs charging, exposure, development, and transfer, and controls the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so that the time required from charging to development is variable. The electrophotographic photoreceptor further comprises a control means, and the electrophotographic photoreceptor has a conductive support and a photosensitive layer containing gallium phthalocyanine formed on the conductive support, and the primary particle diameter of gallium phthalocyanine contained in the photosensitive layer. The maximum value is 0.3 μm or less.

  According to the process cartridge of the present invention, the photosensitive layer of the electrophotographic photosensitive member contains gallium phthalocyanine together with the binder resin, and the maximum primary particle diameter of the gallium phthalocyanine is set to 0.3 μm or less. The electrophotographic characteristics of the photoreceptor can be sufficiently enhanced, and the use conditions can be widened. Therefore, even if image formation is performed while changing the time required from charging to development, it is possible to sufficiently suppress the occurrence of fog and black spots in the output image and the generation of image memory.

  According to the present invention, there is provided an image forming apparatus and a process cartridge capable of suppressing the occurrence of fog and black spots and the generation of image memory in an output image even when image formation is performed by switching a plurality of modes.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as the case may be. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram showing an embodiment of an image forming apparatus according to the present invention. The image forming apparatus shown in FIG. 1 is a so-called tandem digital color printer, and includes a plurality of image forming units corresponding to yellow (Y), magenta (M), cyan (C), and black (K) colors. They are arranged in parallel with each other. Each image forming unit includes an electrophotographic photosensitive member (hereinafter simply referred to as a “photosensitive member”) that is rotatably supported in a predetermined direction, a developing device and a charging roll arranged along the moving direction of the outer peripheral surface of the photosensitive member. And a primary transfer roll, an exposure device, and a cleaning blade, and the charged photoconductor can be irradiated with laser light from a laser output scanner (ROS) 17 that is an exposure device. For example, the black (K) image forming unit includes a photoconductor 11K, a developing device 12K, a charging roll 13K, a primary transfer roll 14K, and a cleaning blade 16K. The charged photoconductor 11K has exposure light. It is possible to irradiate 15K.

  In such an image forming apparatus, each of the photoreceptors 11Y, 11M, 11C, and 11K has a conductive support and a photosensitive layer containing gallium phthalocyanine and a binder resin formed on the conductive support. It is. The maximum primary particle diameter of gallium phthalocyanine contained in the photosensitive layer of each photoconductor is 0.3 μm or less. Details of the structure of the photoreceptor will be described later.

  Further, although not shown in detail, a driving device is connected to each photoconductor. This drive device has a control function for controlling the rotation speed (that is, the movement speed of the outer peripheral surface) of each photoconductor, and makes the time required from charging to development variable in each image forming unit. . With such a control function, it is possible to switch between a plurality of control modes including a normal mode, a low speed mode, and a high speed mode to perform image formation.

  For example, in color image formation in the normal mode, first, in an image forming unit for forming a yellow image, the photoconductor 11Y is charged by a charging roll 13Y to which a voltage is applied, and irradiation with laser light 15Y from the ROS 17 is performed. Thus, an electrostatic latent image is formed, and a toner image is formed by the developing device 12Y. Subsequently, the same process is sequentially performed in each of the magenta (M), cyan (C), and black (K) image forming units to form a color toner image that is multiple-transferred on the intermediate transfer belt. Thereafter, the toner image is transferred onto the recording medium sent from the paper tray 111 by the electric field of the secondary transfer roll 19, heated and fixed by the fixing device 110, and the completed paper as an image is discharged. The rotational speed of the photoconductor in the normal mode is not particularly limited, but it is preferable to set each image forming unit so that the time required from charging to development is 50 to 300 msec.

  Also, when using thick paper or an OHP sheet as a recording medium sent from the paper tray, the fixing process time is sufficient to switch the image forming mode to the low speed mode, that is, to sufficiently fix the developer even using the thick paper or the OHP sheet. It is preferable to lengthen the time, slow the rotation speed of the photoconductor 11 in each image forming unit, and lengthen the time required from charging to development. The procedure for image formation in the low speed mode is the same as that in the normal mode. Further, the rotational speed of the photosensitive member (moving speed of the outer peripheral surface) in the low-speed mode is not particularly limited, but it is preferable to control so as to satisfy the condition expressed by the following formula (1).

T _low ≧ (1/3) T (1)
(In the formula, T represents the time required from charging to developing when performing the electrophotographic process in the normal mode, and T _low represents the time required from charging to developing when performing the electrophotographic process in the _low speed mode.)
When outputting a monochrome image (monochrome image), in the black (K) image forming unit, the photoconductor 11K is charged by the charging roll 13K to which a voltage is applied, and the laser light 15 from the ROS 15 is irradiated. Thus, an electrostatic latent image is formed, and a toner image is formed by the developing device 12K. Thereafter, the toner image is transferred onto the intermediate transfer belt 18 by the electric field of the primary transfer roll 14K. Further, the toner image is transferred onto the recording medium sent from the paper tray 111 by the electric field of the secondary transfer roll 19, heated and fixed by the fixing device 110, and the completed paper as an image is discharged. When such a monochrome image is formed, the image forming mode can be switched to the high speed mode to increase the rotational speed of the photoconductor 11K and shorten the time required from charging to development, thereby forming an image. The rotational speed (moving speed of the outer peripheral surface) of the photoconductor in the high speed mode is not particularly limited, but it is preferable to control so as to satisfy the condition expressed by the following formula (2).

T _high ≦ 3T (2)
(In the formula, T represents the time required from charging to developing when performing the electrophotographic process in the normal mode, and T _high represents the time required from charging to developing when performing the electrophotographic process in the _high speed mode.)
As described above, in the tandem type color image forming apparatus, the photosensitive layers of the photoreceptors 11Y, 11M, 11C, and 11K contain gallium phthalocyanine together with the binder resin, and the maximum primary particle diameter of the gallium phthalocyanine is 0.3 μm. By making the following, the electrophotographic characteristics of the photoreceptor can be sufficiently enhanced, and the use conditions can be widened. Therefore, even when switching to the normal mode, high-speed mode, or low-speed mode and changing the time required from charging to development, image formation is sufficiently suppressed, occurrence of fog and black spots in the output image and generation of image memory are sufficiently suppressed. It becomes possible.

  Next, each element provided in the image forming apparatus of the present invention will be described.

  First, the structure of the photoreceptor will be described in detail. FIG. 2 is a cross-sectional view showing a preferred example of the photoreceptor used in the present invention. A photoreceptor 1 shown in FIG. 2 includes a conductive support 2, an undercoat layer 4 formed on the support 2, and a photosensitive layer 3 formed on the undercoat layer 4. The photosensitive layer 3 has a three-layer structure including a charge generation layer 5, a charge transport layer 6 and a protective layer 7. The charge generation layer 5 is on the side close to the undercoat layer 4, and the side far from the undercoat layer 4 is on. The protective layer 7 and the charge transport layer 6 are disposed between these layers. The charge generation layer 5 contains gallium phthalocyanine, which is controlled so that the maximum primary particle diameter is 0.3 μm or less, as a charge generation material.

  Examples of the conductive support 2 include metals such as aluminum, copper, iron, zinc, nickel, and aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium by vapor deposition. Laminating paper, plastic or glass, metal foil with thin films such as indium oxide and tin oxide, carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide etc. as binder resin Various supports that have been subjected to a conductive treatment by applying a dispersed coating solution are preferably used. There is no restriction | limiting in particular as a shape of the electroconductive support body 1, According to the objective, it can select suitably, For example, it can be set as a drum shape, a sheet form, plate shape, a pipe shape, etc.

  Further, the support 2 can be subjected to various surface treatments such as mirror cutting, etching treatment, anodizing treatment, rough cutting treatment, centerless grinding treatment, sand blasting treatment, wet honing treatment, and the like as necessary. . By roughening the surface of the support 2 by such a surface treatment, it is possible to prevent wood-like density spots due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used. Can do. This is particularly effective when a metal pipe base is used as the support 2.

  The undercoat layer 4 is a layer provided for the purpose of improving electrical characteristics, improving image quality, improving image quality maintenance, improving adhesion between the photosensitive layer 3 and the support 2, and improving leakage resistance. If these characteristics can be achieved without providing the undercoat layer 4, the photosensitive layer 3 may be disposed in close contact with the support 2.

  Constituent materials of the undercoat layer 4 include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate. Resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, etc. Among them, resin insoluble in the upper layer coating solvent is preferably used, especially phenol resin Phenol-formaldehyde resin, melamine resin, urethane resin, epoxy resin and the like are preferably used. These materials may be used individually by 1 type, or may be used in combination of 2 types.

  Moreover, as a constituent material of the undercoat layer 4, an organometallic compound containing zirconium, titanium, aluminum, manganese, silicon atoms, or the like can be used. Among these, organometallic compounds containing zirconium or silicon are excellent in performance, such as low residual potential, little potential change due to environment, and little potential change due to repeated use. These materials may be used individually by 1 type, or may be used in combination of 2 types.

  Examples of organosilicon compounds include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- Examples include γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyl Silane coupling agents such as trimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are particularly preferable.

  Examples of organic zirconium compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate , Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of organic titanium compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the organoaluminum compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

In addition, in order to obtain leak resistance by forming the undercoat layer 4, it is necessary to give an appropriate resistance to the undercoat layer 4. Such resistance can be controlled by allowing the undercoat layer 4 to contain metal oxide fine particles. The metal oxide fine particles used here preferably have a powder resistance of about 10 ² to 10 ¹¹ Ω · cm. Any metal oxide having a powder resistance value in this range can be used, but among these, metal oxide fine particles such as tin oxide, titanium oxide, and zinc oxide having the above resistance values are preferably used. If the resistance value of the metal oxide fine particles is lower than the lower limit of the above range, sufficient leakage resistance cannot be obtained. If the resistance value is higher than the upper limit of the range, there is a concern that the residual potential is increased.

  The metal oxide fine particles contained in the undercoat layer 4 may be subjected to surface treatment. In addition, two or more types having different surface treatments or different particle diameters may be used in combination.

Further, in the surface treatment of the metal oxide fine particles, the surface area of the metal oxide fine particles greatly affects the electrophotographic characteristics after the surface treatment. As the metal oxide fine particles, those having a specific surface area of 10 m ² / g or more are preferably used. Those having a specific surface area value of less than 10 m ² / g tend to cause a decrease in chargeability and tend to make it difficult to obtain good electrophotographic characteristics.

  In the present invention, surface treatment with a coupling agent may be performed on the metal oxide fine particles. The coupling agent is not particularly limited as long as the desired photoreceptor characteristics can be obtained. Specific examples of coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycid. Xylpropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (amino Examples include silane coupling agents such as ethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. It is not limited to. Moreover, these coupling agents can also be used in mixture of 2 or more types.

  As the surface treatment method, any known method can be used. For example, a dry method or a wet method can be used. When surface treatment is performed by a dry method, while stirring the metal oxide fine particles with a mixer having a large shearing force, the coupling agent is dropped alone or as a solution dissolved in an organic solvent or water, and dried air And uniformly treated by spraying with nitrogen gas. The addition or spraying is preferably performed at a temperature of 50 ° C. or higher. After addition or spraying, baking can be performed 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 such a dry method, the surface adsorbed water can be removed by heating and drying the metal oxide fine particles before the surface treatment with the coupling agent. By removing the surface adsorbed water before the treatment, the coupling agent can be uniformly adsorbed on the surface of the metal oxide fine particles. The metal oxide fine particles can be heat-dried while stirring with a mixer having a large shearing force.

  On the other hand, as a wet method, metal oxide fine particles are dispersed in a solvent using stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., and after adding or coupling or dispersing a coupling agent solution, the solvent is removed. Is processed uniformly. After removing the solvent, baking can be performed 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. Even in the wet method, the surface adsorbed water can be removed before the surface treatment of the metal oxide fine particles with the coupling agent. This surface adsorbed water removal method is implemented by a method of removing by heating and drying in a solvent used for surface treatment, a method of removing by azeotropy with a solvent, etc. in addition to removal by heating and drying as in the dry method. The

  The amount of the surface treatment agent relative to the metal oxide fine particles is appropriately selected according to the intended electrophotographic characteristics.

  Furthermore, various additives can be added to the undercoat layer 4 in order to improve electrical characteristics, environmental stability, and image quality. Additives include quinone compounds such as chloranilquinone, bromoanilquinone, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone Fluorenone compounds such as 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4 -Oxadiazole compounds such as oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ', 5,5'tetra -Electron transporting substances such as diphenoquinone compounds such as t-butyldiphenoquinone, electron transporting pigments such as polycyclic condensation systems and azo systems, zirconium chelates Compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds. Furthermore, a silane coupling agent used for the surface treatment of the metal oxide fine particles can be added to the undercoat layer 4 alone as an additive.

  Examples of the titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, and titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  The undercoat layer 4 can be formed using a coating solution obtained by adding the above material to a predetermined solvent. The solvent for the coating solution for forming the undercoat layer can be arbitrarily selected from organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, and esters. More specifically, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, Examples include dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like. These solvents can be used alone or in admixture of two or more.

  Moreover, when the undercoat layer 4 contains metal oxide fine particles, it is preferable to perform a dispersion treatment when preparing the coating solution. As a dispersing method, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  In addition, as a method for applying the coating liquid for forming the undercoat layer, conventional methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method can be used. Can be used.

  The thickness of the undercoat layer 4 can be arbitrarily set within a range in which desired characteristics are obtained, but is preferably 15 μm or more, and more preferably 20 to 50 μm. Further, the Vickers strength of the undercoat layer 4 is preferably 35 or more.

  In order to prevent a moire image, the surface roughness of the undercoat layer 4 should be adjusted within a range of ¼ n (n is the refractive index of the upper layer) to λ with respect to the exposure laser wavelength λ used. Is preferred. The surface roughness can be adjusted, for example, by adding resin particles to the undercoat layer 4. Examples of the resin particles include silicone resin particles and cross-linked PMMA resin particles. Further, the undercoat layer may be polished for adjusting the surface roughness. As a polishing method, buffing, sandblasting, wet honing, grinding, or the like can be used.

  Further, an intermediate layer may be further provided between the undercoat layer 4 and the photosensitive layer 3 in order to improve electrical characteristics, improve image quality, improve image quality maintenance, and improve photosensitive layer adhesion. For this intermediate layer, the same material and manufacturing method as the undercoat layer 4 can be used.

  In the case where an intermediate layer is provided between the undercoat layer 4 and the photosensitive layer 3, the intermediate layer serves as an electrical blocking layer in addition to improving the coatability of the upper layer (such as the charge generation layer 5). When the film thickness is too large, the electrical barrier becomes too strong and tends to cause desensitization or increase in potential due to repeated image formation. Therefore, when forming the intermediate layer using the above-mentioned material, it is preferably set in a film thickness range of 0.1 to 5 μm.

  The charge generation layer 5 contains gallium phthalocyanine as a charge generation material and a binder resin. As such gallium phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine are preferable.

  The hydroxygallium phthalocyanine is not particularly limited as long as it does not include those whose primary particle diameter exceeds 0.3 μm, but those having absorption within the range of 810 to 839 nm of the maximum peak in the range of 600 to 900 nm of the spectral absorption spectrum. preferable. Since the hydroxygallium phthalocyanine having such absorption is very fine and has a uniform shape, it is possible to effectively prevent the mixing of coarse particles exceeding 0.3 μm into the charge generation layer 5.

Moreover, the specific surface area value by BET method of hydroxygallium phthalocyanine is preferably 45 m ² / g or more, more preferably 50 m ² / g or more, and further preferably 55 m ² / g or more. Further, hydroxygallium phthalocyanine has a Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray of 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25. It is preferable to have diffraction peaks at 1 ° and 28.3 °.

  Said preferable hydroxygallium phthalocyanine can be obtained, for example, by the method shown below.

  First, a method of reacting o-phthalodinitrile or 1,3-diiminoisoindoline and gallium trichloride in a predetermined solvent (type I chlorogallium phthalocyanine method); o-phthalodinitrile, alkoxygallium and ethylene glycol Crude gallium phthalocyanine is produced by a method of synthesizing a phthalocyanine dimer (phthalocyanine dimer) by reacting with heating in a predetermined solvent (phthalocyanine dimer method). As the solvent in the above reaction, α-chloronaphthalene, β-chloronaphthalene, α-methylnaphthalene, methoxynaphthalene, dimethylaminoethanol, diphenylethane, ethylene glycol, dialkyl ether, quinoline, sulfolane, dichlorobenzene, dimethylformamide, dimethyl It is preferable to use an inert and high boiling point solvent such as sulfoxide or dimethylsulfamide.

  Next, the crude gallium phthalocyanine obtained in the above step is subjected to an acid pasting process, whereby the crude gallium phthalocyanine is made into fine particles and converted into an I-type hydroxygallium phthalocyanine pigment. Here, the acid pasting treatment is, specifically, a solution in which crude gallium phthalocyanine is dissolved in an acid such as sulfuric acid or an acid salt such as a sulfate is poured into an aqueous alkaline solution, water or ice water, Recrystallized. As the acid used for the acid pasting treatment, sulfuric acid is preferable, and sulfuric acid having a concentration of 70 to 100% (particularly preferably 95 to 100%) is more preferable.

  Next, the target hydroxygallium phthalocyanine is obtained by wet-grinding the I-type hydroxygallium phthalocyanine pigment obtained by the acid pasting process together with a solvent to convert the crystal. In the present invention, the wet pulverization treatment is preferably a pulverization apparatus using spherical media having an outer diameter of 0.1 to 3.0 mm, and particularly preferably spherical media having an outer diameter of 0.2 to 2.5 mm. . When the outer shape of the media is larger than 3.0 mm, the pulverization efficiency is lowered, so that the particle diameter is not reduced and aggregates are easily generated. Moreover, when smaller than 0.1 mm, it becomes difficult to isolate | separate a medium and a hydroxygallium phthalocyanine. In addition, when the media is not spherical, but in other shapes such as a columnar shape or an indefinite shape, the grinding efficiency is reduced and the media is easily worn by grinding, so that the wear powder becomes an impurity and degrades the characteristics of hydroxygallium phthalocyanine. It becomes easy.

  The material of the media is not particularly limited, but those that do not easily cause image quality defects even when mixed in the pigment are preferable, and glass, zirconia, alumina, meno and the like can be preferably used. The material of the container is not particularly limited, but is preferably one that hardly causes image quality defects even when mixed in a pigment, and glass, zirconia, alumina, meno, polypropylene, polytetrafluoroethylene, polyphenylene sulfide, etc. are preferably used. it can. Further, glass, polypropylene, polytetrafluoroethylene, polyphenylene sulfide, or the like may be lined on the inner surface of a metal container such as iron or stainless steel.

  The amount of media used varies depending on the apparatus used, but is 50 parts by weight or more, preferably 55 to 100 parts by weight per 1 part by weight of the type I hydroxygallium phthalocyanine pigment. Also, as the media outer diameter decreases, the media density in the device increases even with the same weight, and the viscosity of the mixed solution increases and the grinding efficiency changes. It is desirable to perform wet processing at an optimal mixing ratio by controlling the amount used.

  The temperature of the wet pulverization treatment is 0 to 100 ° C, preferably 5 to 80 ° C, more preferably 10 to 50 ° C. When the temperature is low, the rate of crystal transition becomes slow, and when the temperature is too high, the solubility of hydroxygallium phthalocyanine becomes high and crystal growth is likely to be difficult.

  Examples of the solvent used in the wet grinding treatment include amides such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone; esters such as ethyl acetate, n-butyl acetate, and iso-amyl acetate. In addition to ketones such as acetone, methyl ethyl ketone, methyl iso-butyl ketone, dimethyl sulfoxide and the like. The amount of these solvents used is usually 1 to 200 parts by weight, preferably 1 to 100 parts by weight, based on 1 part by weight of the hydroxygallium phthalocyanine pigment.

  As an apparatus used for the wet pulverization treatment, an apparatus using a media such as a vibration mill, an automatic mortar, a sand mill, a dyno mill, a coball mill, an attritor, a planetary ball mill, or a ball mill as a dispersion medium can be used.

  The progress of crystal conversion is greatly influenced by the scale of the wet pulverization process, the stirring speed, the media material, etc., but the maximum peak in the range of 600-900 nm of the spectral absorption spectrum of hydroxygallium phthalocyanine is within the range of 810-839 nm. In order to have absorption, the crystal conversion state is monitored by measuring the absorption wavelength of the wet pulverization treatment liquid, and is continued until it is converted to the hydroxygallium phthalocyanine of the present invention. Generally, the treatment time for the wet pulverization treatment is in the range of 5 to 500 hours, preferably in the range of 7 to 300 hours. When the processing time is less than 5 hours, the crystal conversion is not completed, and the problem of deterioration of electrophotographic characteristics, particularly insufficient sensitivity is likely to occur. In addition, when the processing time is increased from 500 hours, problems such as a decrease in sensitivity due to the influence of pulverization stress, a decrease in productivity, and the mixing of abrasive powder of media occur. By determining the wet pulverization time in this way, the wet pulverization can be completed in a state where the hydroxygallium phthalocyanine particles are uniformly atomized.

  The chlorogallium phthalocyanine used in the present invention is not particularly limited as long as it does not include those whose primary particle diameter exceeds 0.3 μm, but the maximum peak in the range of 600 to 900 nm of the spectral absorption spectrum is in the range of 770 to 790 nm. Those having internal absorption are preferred. Chlorogallium phthalocyanine having such absorption is very fine and has a uniform shape, and therefore, mixing of coarse particles exceeding 0.3 μm into the charge generation layer 5 can be effectively prevented.

  The preferable chlorogallium phthalocyanine can be suitably obtained by crystal conversion by wet pulverization in the same manner as in the case of hydroxygallium phthalocyanine.

  These gallium phthalocyanines may be coated with an organometallic compound having a hydrolyzable group or a silane coupling agent. Such coating treatment improves the dispersibility of the charge generation material and the coating property of the charge generation layer coating solution, and can easily and reliably form a smooth and highly uniform charge generation layer. Image quality defects such as fogging and ghosting can be prevented, and image quality maintenance can be improved. Further, the storage stability of the coating solution for the charge generation layer is remarkably improved, which is effective in extending the pot life, and the cost of the photoconductor can be reduced.

  The organometallic compound or silane coupling agent having a hydrolyzable group preferably has a structure represented by the following general formula (2).

_{R p -M-Y q (2} )
(In the formula, R represents an organic group, M represents a metal atom other than an alkali metal or a silicon atom, Y represents a hydrolyzable group, p and q are each an integer of 1 to 4, and p and q Is equivalent to the valence of M.)
In the general formula (2), examples of the organic group represented by R include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group and an octyl group, an alkenyl group such as a vinyl group and an allyl group, and a cyclohexyl group. Aryl group such as cycloalkyl group, phenyl group, naphthyl group, alkaryl group such as tolyl group, arylalkyl group such as benzyl group, phenylethyl group, arylalkenyl group such as styryl group, furyl group, thienyl group, pyrrolidinyl group And heterocyclic residues such as pyridyl group and imidazolyl group. These organic groups may have one or two or more kinds of substituents.

  In the general formula (2), examples of the hydrolyzable group represented by Y include methoxy group, ethoxy group, propoxy group, butoxy group, cyclohexyloxy group, phenoxy group, benzyloxy group and other ether groups, acetoxy group, Examples include propionyloxy groups, acryloxy groups, methacryloxy groups, benzoyloxy groups, methanesulfonyloxy groups, benzenesulfonyloxy groups, ester groups such as benzyloxycarbonyl groups, halogen atoms such as chlorine atoms, and the like.

  In the general formula (2), M is not particularly limited as long as it is other than an alkali metal, but is preferably a titanium atom, an aluminum atom, a zirconium atom or a silicon atom. That is, in the present invention, an organic titanium compound, an organic aluminum compound, an organic zirconium compound, or a silane coupling agent in which the above organic group or hydrolyzable functional group is substituted is preferably used.

  Examples of silane coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are more preferable.

  Moreover, the hydrolysis product of said organometallic compound and a silane coupling agent can also be used. As this hydrolysis product, Y (hydrolyzable group) or R (organic group) bonded to M (metal atom or silicon atom other than alkali metal) of the organometallic compound represented by the general formula (2). The hydrolyzable group to be substituted is hydrolyzed. Note that. When the organometallic compound and the silane coupling agent contain a plurality of hydrolyzable groups, it is not always necessary to hydrolyze all the functional groups, and a partially hydrolyzed product may be used. Moreover, these organometallic compounds and silane coupling agents may be used alone or in combination of two or more.

  As a method of coating gallium phthalocyanine using an organometallic compound having a hydrolyzable group and / or a silane coupling agent (hereinafter simply referred to as “organometallic compound”), the gallium phthalocyanine crystal is prepared in the process of preparing the gallium phthalocyanine crystal. A method of coating phthalocyanine, a method of coating before gallium phthalocyanine is dispersed in the binder resin, a method of mixing an organometallic compound when gallium phthalocyanine is dispersed in the binder resin, and a method of mixing gallium phthalocyanine into the binder resin Examples of the method include a method of further dispersing treatment with an organometallic compound after dispersion.

  More specifically, as a method of coating in advance in the process of preparing the gallium phthalocyanine crystal, a method of mixing and heating the organometallic compound and gallium phthalocyanine before the crystal is aligned, and before the crystal of the organometallic compound is aligned For example, a method of mechanically dry-grinding with gallium phthalocyanine and a mixture of organic metal compound in water or organic solvent with gallium phthalocyanine before crystal alignment and wet pulverization.

  Further, as a method of coating the gallium phthalocyanine before dispersing it in the binder resin, an organic metal compound, water or a mixed solution of water and an organic solvent, a method of mixing and heating gallium phthalocyanine, an organic metal compound There are a method of spraying directly on gallium phthalocyanine, a method of mixing an organometallic compound with gallium phthalocyanine, and milling.

  In addition, as a method of mixing treatment at the time of dispersion, a method of mixing while sequentially adding an organometallic compound, gallium phthalocyanine, and a binder resin to a dispersion solvent, a method of simultaneously adding and mixing these charge generation layer forming components, etc. It is done.

  Moreover, as a method of further dispersing the gallium phthalocyanine in the binder resin and further dispersing with an organometallic compound, for example, a method of adding an organometallic compound diluted with a solvent to the dispersion and dispersing it with stirring can be mentioned. Further, in the dispersion treatment, an acid such as sulfuric acid, hydrochloric acid, trifluoroacetic acid or the like may be added as a catalyst in order to adhere more firmly to gallium phthalocyanine.

  Among these, a method of coating in advance in the process of preparing gallium phthalocyanine crystals, or a method of coating before dispersing gallium phthalocyanine in the binder resin is preferable.

  The binder resin used for the charge generation layer 5 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 acetal 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, and the like, among which polyvinyl acetal resin is particularly preferable. These binder resins may be used individually by 1 type, and may be used in combination of 2 or more type. The blending ratio (weight ratio) between the charge generating substance and the binder resin in the charge generating layer is preferably in the range of 10: 1 to 1:10.

  The charge generation layer 5 is formed by vacuum deposition of a charge generation material or application of a coating liquid containing a charge generation material and a binder resin. The solvent of the coating solution is not particularly limited as long as it can dissolve the binder resin, and is arbitrarily selected from, for example, alcohol, aromatic compound, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, and the like. More specifically, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, acetic acid Examples include n-butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like. These solvents may be used alone or in combination of two or more.

  As a method for dispersing the charge generating material and the binder resin in a solvent, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  In addition, an additive may be added to the charge generation layer coating solution in order to improve electrical characteristics, improve image quality, and the like. Such additives include quinone compounds such as chloranilquinone, bromoanilquinone, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-. Fluorenone compounds such as fluorenone, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3 Oxadiazole compounds such as 4-oxadiazole and 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5 Electron transporting substances such as diphenoquinone compounds such as' -tetra-t-butyldiphenoquinone, electron transporting pigments such as polycyclic condensation systems and azo systems, silane coupling Agent, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, and the like.

  As silane coupling agents, vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ -Aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane and the like.

  Zirconium chelate compounds include: zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthenic acid Zirconium, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate). These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  Examples of the application method of the coating liquid include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method. A small amount of silicone oil can be added to the coating solution as a leveling agent for improving the smoothness of the coating film. The film thickness of the charge generation layer 5 thus obtained is preferably 0.05 to 5 μm, more preferably 0.1 to 2.0 μm.

  Next, the charge transport layer 6 will be described. As the charge transport layer 6, a layer formed by a known technique can be used. These charge transport layers are formed containing a charge transport material and a binder resin, or are formed containing a polymer charge transport material.

  Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds , Electron transport compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore-transporting compounds. These charge transport materials can be used alone or in combination of two or more, but are not limited thereto. These charge transport materials can be used alone or in combination of two or more. From the viewpoint of mobility, compounds represented by the following general formula (3) or (4) are preferred.

(Wherein R ¹ represents a hydrogen atom or a methyl group, n represents 1 or 2, Ar ¹ and Ar ² may be the same or different, and each represents a substituted or unsubstituted aryl group, —C (R ² ) = C (R ³ ) (R ⁴ ), or —CH═CH—CH═C (Ar) ₂ , and the substituent is a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a carbon number Is a substituted amino group substituted with an alkoxy group having 1 to 5 carbon atoms or an alkyl group having 1 to 3 carbon atoms, wherein R ² , R ³ and R ⁴ are hydrogen atoms, substituted or unsubstituted. An alkyl group, a substituted or unsubstituted aryl group, and Ar represents a substituted or unsubstituted aryl group.

(In the formula, R ⁵ and R ^{5 ′} may be the same or different and each represents 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, and R ⁶ and R ^{6. 'And} R ⁷ and R ^7' may be the same or different, and are each 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. An amino group substituted with a substituted or unsubstituted aryl group, or a group represented by —C (R ⁸ ) ═C (R ⁹ ) (R ¹⁰ ) (R ⁸ , R ⁹ , R ¹⁰ ; a hydrogen atom; A substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group), a, b, c and d may be the same or different and each represents an integer of 0 to 2.)

(In the formula, R ¹¹ is 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) _2. In which R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ may be the same or different, and each represents a hydrogen atom, a halogen atom, or a carbon number of 1 to 5 And an amino group substituted with an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group.)
Examples of the binder resin used for the charge transport layer 6 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 -N-vinylcarbazole, polysilane, etc. are mentioned. 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 may be formed by mixing with the low molecular charge transport material or the binder resin.

  The charge transport layer 6 can be formed using a coating solution obtained by adding the above constituent materials to a predetermined solvent. Examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene, ketones such as acetone and 2-butanone, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and ethylene chloride, tetrahydrofuran, Examples thereof include organic solvents such as cyclic or linear ethers such as ethyl ether. These solvents 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.

Further, additives such as an antioxidant, a light stabilizer, and a heat stabilizer are added to the charge transport layer 6 for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light or heat generated in the copying machine. Can be added. For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, and organic phosphorus compounds. Examples of the light stabilizer include derivatives such as benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine. Further, for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use, at least one kind of electron accepting substance can be contained. Examples of the electron acceptor usable in the photoreceptor of the present invention include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o -Dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid, etc., and compounds represented by general formula (I) Can do. Of these, benzene derivatives having an electron-withdrawing substituent such as fluorenone, quinone and Cl, CN, NO ₂ are particularly preferred. A small amount of silicone oil can also be added to the coating solution as a leveling agent for improving the smoothness of the coating film. The charge transport layer can also contain fine particles such as silica and PTFE.

  The film thickness of the charge transport layer 6 thus formed is preferably 5 to 50 μm, more preferably 10 to 45 μm.

  Next, the protective layer 7 will be described. The protective layer 7 is used to prevent chemical change of the charge transport layer 6 when the photosensitive member 1 is charged or to further improve the mechanical strength of the photosensitive layer 3. If the charge transport layer 6 has sufficient chemical or mechanical strength, the charge transport layer 6 may be the outermost surface layer without providing the protective layer 7.

  The protective layer 7 is formed, for example, by applying a coating solution containing a conductive material in an appropriate binder resin onto the photosensitive layer 3. The conductive material constituting the protective layer 7 is not particularly limited, and examples thereof include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl). )-[1,1′-biphenyl] -4,4′-diamine and other aromatic amine compounds, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, and barium sulfate A solid solution carrier with antimony oxide, a mixture of the above metal oxides, a mixture of the above metal oxides in a single particle of titanium oxide, tin oxide, zinc oxide or barium sulfate, or titanium oxide, tin oxide, Examples include zinc oxide or barium sulfate single particles coated with the above metal oxide.

  The binder resin used for the protective layer 7 is polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamideimide. Known resins such as resins are used. These can also be used by cross-linking each other as necessary.

  The thickness of the protective layer 7 is preferably 1 to 20 μm, and more preferably 2 to 10 μm.

  As a coating method of the coating liquid for forming the protective layer 7, a common method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used. Moreover, as a solvent used for the coating liquid for forming the protective layer 7, a normal organic solvent such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene, etc. may be used alone or in admixture of two or more. However, it is preferable to use a solvent that hardly dissolves the lower layer (such as the charge transport layer 6) to which the coating solution is applied.

  Although FIG. 2 shows an example of the function separation type photoreceptor, the photoreceptor provided in the image forming apparatus of the present invention has a photosensitive layer containing both a charge generation material (gallium phthalocyanine) and a charge transport material. A single-layer type photoreceptor provided may be used.

  Next, the charging device will be described. As the charging device provided in the image forming apparatus of the present invention, a conventionally known non-contact method using a corotron or scorotron, or a contact charging method using a charging roll, a charging brush, a charging film, a charging tube or the like can be adopted. The image forming apparatus shown in FIG. 1 includes a contact charging device as a charging device.

  In the contact charging method, the surface of the photosensitive member is charged by applying a voltage to a conductive member brought into contact with the surface of the photosensitive member. 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, but a roller-like member is particularly preferable. Usually, the roller-shaped member is composed of a resistance layer, an elastic layer that supports them, and a core from the outside. Furthermore, a protective layer can be provided outside the resistance layer as necessary.

The roller-like member rotates at the same peripheral speed as that of the photoreceptor without contacting the photoreceptor, and functions as a charging means. However, some driving means may be attached to the roller member, and the roller member may be rotated and charged at a peripheral speed different from that of the photosensitive member. The core material is conductive and generally used is iron, copper, brass, stainless steel, aluminum, nickel, or the like. In addition, a resin molded product in which conductive particles are dispersed can be used. The material of the elastic layer is conductive or semiconductive, and generally is a rubber material in which conductive particles or semiconductive particles are dispersed. 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 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, MgO can be used, These materials may be used alone or in combination of two or more. 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. The resistivity is 10 ³ to 10 ¹⁴ Ωcm, preferably 10 ⁵ to 10. ^{It is 12} Ωcm, more preferably 10 ⁷ to 10 ¹² Ωcm. Moreover, as a film thickness, 0.01-1000 micrometers, Preferably it is 0.1-500 micrometers, More preferably, 0.5-100 micrometers is good. 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, A polyolefin resin such as PET, a styrene-butadiene resin, or the like is used. As the conductive particles or semiconductive particles, the same carbon black, metal, and metal oxide as the elastic layer are used. 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 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, or the like can be used.

  As a method for charging the photosensitive member using these conductive members, a voltage is applied to the conductive member. The applied voltage is preferably a DC voltage or a DC voltage superimposed with an AC voltage. As the voltage range, the DC voltage is preferably positive or negative 50 to 2000 V, particularly preferably 100 to 1500 V, depending on the required photoreceptor charging potential. Moreover, the peak-to-peak voltage when the AC voltage is superimposed is preferably 400 to 1800 V, more preferably 800 to 1600 V, and still more preferably 1200 to 1600 V. The frequency of the AC voltage is preferably 50 to 20,000 Hz, more preferably 100 to 5,000 Hz.

  As the exposure apparatus, 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 in a desired image-like manner on the surface of the photoreceptor can be used. Among these, when an exposure apparatus capable of exposing non-interference light is used, interference fringes between the support (substrate) of the photoreceptor 1-1 and the photosensitive layer can be prevented.

  As the developing device, a conventionally known developing device using a normal or reversal developer such as a one-component system or a two-component system can be used. The shape of the toner that can be used is not particularly limited, but a spherical toner is preferable from the viewpoint of high image quality and ecology. The spherical toner is a spherical toner having an average shape factor (ML2 / A) of preferably 100 to 130, more preferably 100 to 125 in order to achieve high transfer efficiency. If this average shape factor (ML2 / A) is larger than 130, the transfer efficiency is lowered, and the deterioration of the image quality of the print sample can be visually confirmed.

  The spherical toner contains at least a binder resin and a colorant. The spherical toner may preferably use 2 to 12 μm particles, more preferably 3 to 9 μm particles.

  Examples of the binder resin include homopolymers and copolymers such as styrenes, monoolefins, vinyl esters, α-methylene aliphatic monocarboxylic acid esters, vinyl ethers, and vinyl ketones. Typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Examples thereof include coalescence, polyethylene, and polypropylene. Furthermore, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax, and the like can also be mentioned.

  Coloring agents include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, and lamp black. Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is a typical example.

  The spherical toner may be subjected to internal addition treatment or external addition treatment with a known additive such as a charge control agent, a release agent, and other inorganic fine particles.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  Known charge control agents can be used, but azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups can be used.

  As other inorganic fine particles, small-diameter inorganic fine particles having an average primary particle size of 40 nm or less are used for the purpose of powder fluidity, charge control, etc., and if necessary, larger diameters are used to reduce adhesion. Inorganic or organic fine particles may be used in combination. As these other inorganic fine particles, known ones can be used.

  In addition, the surface treatment of the small-diameter inorganic fine particles is effective because the dispersibility becomes high and the effect of increasing the powder fluidity increases.

  The spherical toner is not particularly limited by the production method, and can be obtained by a known method. Specifically, for example, a kneading and pulverizing method, a method of changing the shape of particles obtained by the kneading and pulverizing method with mechanical impact force or thermal energy, an emulsion polymerization aggregation method, a dissolution suspension method and the like can be mentioned. In addition, a manufacturing method may be performed in which the spherical toner obtained by the above method is used as a core, and aggregated particles are further adhered and heat-fused to give a core-shell structure. When the external additive is added, it can be produced by mixing the spherical toner and the external additive with a Henschel mixer or a V blender. In addition, when the spherical toner is manufactured by a wet method, it can be externally added by a wet method.

  As the intermediate transfer member, a conventionally known conductive thermoplastic resin can be used. For example, conductive resin-containing polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT Examples thereof include conductive thermoplastic resins such as blend materials. 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.

  The intermediate transfer member may be composed of only the above resin layer, or may have a protective layer on the surface of the resin layer.

  When a belt-like member (intermediate transfer belt) is used as the intermediate transfer member, the film thickness can be appropriately selected according to the hardness of the material, but is preferably 50 to 500 μm, more preferably 60 to 150 μm. .

  As described in JP-A-63-311263, a polyimide resin belt in which a conductive agent is dispersed contains 5 to 20% by weight of carbon black as a conductive agent in a polyamic acid solution as a polyimide precursor. After dispersing and casting the dispersion on a metal drum and drying, the film peeled off from the drum is stretched at a high temperature to form a polyimide film, and further cut into an appropriate size to obtain an endless belt. Manufactured. 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. This is carried out by proceeding a ring-closing reaction) and carrying out main curing. 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 by heating.

  The cleaning device is for removing residual toner adhering to the surface of the photoreceptor after the transfer process, and the photoreceptor thus cleaned is repeatedly used for the image forming process. In the present invention, a cleaning device such as a cleaning blade, brush cleaning, and roll cleaning can be used. However, it is preferable to use a cleaning blade as in the device shown in FIG. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  Although not shown in FIG. 1, the electrophotographic apparatus of the present invention may further include a static eliminating device such as an erase light irradiation device. This prevents a phenomenon in which the residual potential of the photoconductor is brought into the next cycle when the photoconductor is used repeatedly, so that the image quality can be further improved.

  FIG. 1 shows an example of a tandem type color image forming apparatus. However, the image forming apparatus of the present invention includes a monochrome image forming apparatus or a color image forming apparatus provided with a rotary type developing device (also referred to as a rotary developing device). An apparatus including one image forming unit such as an apparatus may be used. Here, the rotary type developing device is a developing device of a type in which a plurality of developing devices are rotated and moved, only a necessary developing device is opposed to the photosensitive member, and toner of a desired color is sequentially formed on the photosensitive member. means.

  Further, in the present invention, the photosensitive member and at least one selected from a charging device, a developing device, a transfer device, and a cleaning device may be integrated to form a process cartridge that can be attached to and detached from the image forming apparatus. In this case as well, the moving speed of the outer peripheral surface of the photoconductor can be controlled by a driving device or the like, and the time required from charging to development can be made variable. The process cartridge of the present invention is configured to include control means (such as a driving device) for controlling the moving speed of the outer peripheral surface of the photoreceptor. In the image forming apparatus of the present invention, the control means is independent of the process cartridge. May be provided.

  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.

(Synthesis Example 1)
30 parts by weight of 1,3-diiminoisoindoline and 9.1 parts by weight of gallium trichloride were added to 230 parts by weight of dimethyl sulfoxide and reacted at 160 ° C. with stirring for 6 hours to obtain reddish purple crystals. The obtained crystal was washed with dimethyl sulfoxide, then washed with ion-exchanged water, and dried to obtain 28 parts by weight of crude crystals of type I chlorogallium phthalocyanine. Next, 10 parts by weight of the obtained crude crystals of type I chlorogallium phthalocyanine sufficiently dissolved in 300 parts of sulfuric acid (concentration 97%) heated to 60 ° C. were added to 600 parts by weight of 25% aqueous ammonia and ion-exchanged water. It was dripped in the mixed solution with 200 weight part. The precipitated crystals were collected by filtration, further washed with ion exchange water, and dried to obtain 8 parts by weight of type I hydroxygallium phthalocyanine. Using 6 parts by weight of the obtained type I hydroxygallium phthalocyanine together with 90 parts by weight of N, N-dimethylformamide and 350 parts by weight of glass spherical media having an outer diameter of 0.9 mm, using a glass ball mill. Wet grinding was performed at 25 ° C. for 48 hours. The progress of crystal conversion was monitored by measuring the absorption wavelength of the wet pulverization treatment liquid, and it was confirmed that the maximum peak λ _MAX in the range of 600 to 900 nm of the spectral absorption spectrum of hydroxygallium phthalocyanine was 827 nm. Next, the obtained crystal is washed with acetone, dried, and the Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray is 7.5 °, 9.9 °, 12.5 °, 16. 5.5 parts by weight of hydroxygallium phthalocyanine having diffraction peaks at 3 °, 18.6 °, 25.1 ° and 28.3 ° were obtained.

FIG. 3 shows an X-ray diffraction spectrum of the obtained hydroxygallium phthalocyanine, FIG. 4 shows a spectral absorption spectrum, and FIGS. In addition, the absorption maximum wavelength λ _MAX in the spectral absorption spectrum of the obtained hydroxygallium phthalocyanine, the specific surface area value by the BET method, and the presence or absence of coarse particles by TEM observation (the primary particle diameter exceeds 0.3 μm; the same applies hereinafter). Table 1 shows.

(Synthesis Example 2)
30 parts by weight of 3-diiminoisoindoline and 9.1 parts by weight of gallium trichloride were added to 230 parts by weight of dimethyl sulfoxide and reacted at 160 ° C. with stirring for 6 hours to obtain red purple crystals. The obtained crystal was washed with dimethyl sulfoxide, then washed with ion-exchanged water, and dried to obtain 28 parts by weight of crude crystals of type I chlorogallium phthalocyanine. Next, 10 parts by weight of the obtained crude crystals of type I chlorogallium phthalocyanine were placed in an alumina pot together with 100 parts by weight of 12 mmφ alumina beads, and this was put into a vibration mill (MB-1 type: manufactured by Chuo Kako Co., Ltd.). It was mounted and dry milled for 100 hours. Then, 5 parts by weight of the dry-milled crystals were ball milled together with 60 parts by weight of 5 mmφ glass beads and 50 parts by weight of dimethyl sulfoxide at room temperature for 24 hours, washed with 3000 parts by weight of ethyl acetate, and filtered. Then, by vacuum drying at 60 ° C. for 24 hours, 4.6 parts by weight of chlorogallium phthalocyanine crystals were obtained.

An X-ray diffraction spectrum of the obtained chlorogallium phthalocyanine is shown in FIG. 8, a spectral absorption spectrum is shown in FIG. 9, and a TEM photograph is shown in FIGS. Table 1 shows the absorption maximum wavelength λ _MAX in the spectral absorption spectrum of the obtained chlorogallium phthalocyanine, the specific surface area value by the BET method, and the presence or absence of coarse particles by TEM observation.

(Synthesis Example 3)
In the same manner as in Synthesis Example 1, type I hydroxygallium phthalocyanine (before wet pulverization) was prepared. Next, 5 parts by weight of type I hydroxygallium phthalocyanine was stirred with 80 parts by weight of N, N-dimethylformamide at 25 ° C. for 48 hours using a glass stirring tank having a stirring device. It was confirmed that the maximum peak λ _MAX in the spectral absorption spectrum of hydroxygallium phthalocyanine was 854 nm. The resulting crystals are then washed with acetone, dried and 7.5 °, 9.9 °, 12.5 °, Bragg angles (2θ ± 0.2 °) with respect to CuKα characteristic X-rays, 5.5 parts by weight of hydroxygallium phthalocyanine having diffraction peaks at 16.3 °, 18.6 °, 25.1 °, and 28.3 ° were obtained.

FIG. 13 shows an X-ray diffraction spectrum of the obtained hydroxygallium phthalocyanine, FIG. 14 shows a spectral absorption spectrum, and FIGS. 15 to 17 show TEM photographs. In addition, the absorption maximum wavelength λ _MAX in the spectral absorption spectrum of the obtained hydroxygallium phthalocyanine, the specific surface area value by the BET method, and the presence or absence of coarse particles by TEM observation (the primary particle diameter exceeds 0.3 μm; the same applies hereinafter). Table 1 shows.

  In addition, the measurement of the X-ray diffraction spectrum in a present Example was performed on condition of the following using the CuK (alpha) characteristic X ray by the powder method.

Measuring instrument: X-ray diffractometer Miniflex manufactured by Rigaku Corporation
X-ray tube: Cu
Tube current: 15 mA
Scan speed: 5.0 deg. / Min
Sampling interval: 0.02 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 35 deg.
X-ray tube: Cu
Tube current: 15 mA
Scan speed: 5.0 deg. / Min
Sampling interval: 0.02 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 35 deg.
Step angle (2θ): 0.02 deg. .

  Spectral absorption spectrum measurement was performed using a U-2000 type spectrophotometer manufactured by Hitachi, Ltd., and the measurement liquid was prepared by dispersing 0.6 g of gallium phthalocyanine in 8 mL of n-butyl acetate at room temperature. The specific surface area value was measured using a BET specific surface area measuring instrument (Flow Soap II 2300, manufactured by Shimadzu Corporation). Moreover, the particle shape state of the obtained gallium phthalocyanine was observed using a transmission electron microscope (H-9000, manufactured by Hitachi, Ltd.).

(Example 1)
The surface of a cylindrical aluminum cutting tube having a length of 404 mm, an inner diameter of φ28 mm, and an outer diameter of φ30 mm is roughened by honing treatment, washed with a surfactant and pure water, and dried at 135 ° C. for 5 minutes. Drying was performed. Then, 24 degreeC cooling air was sprayed for 5 minutes at 10 m / sec, and the electroconductive support body was produced.

170 parts by weight of n-butyl alcohol in which 4 parts by weight of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) is dissolved, 20 parts by weight of an organic zirconium compound (acetylacetone zirconium butyrate), and a mixture of organic silane compounds (γ- 10 parts by weight of aminopropyltrimethoxysilane) were mixed and stirred, and this was used as a coating solution for the intermediate layer. This coating solution is applied onto the conductive support, air-dried at room temperature for 5 minutes, heated to 50 ° C. for 10 minutes, and then placed in a constant temperature and humidity chamber at 50 ° C. and 85% RH. For 20 minutes, and then dried in a hot air dryer at 150 ° C. for 10 minutes to form an intermediate layer having a layer thickness of 1 μm.
As a charge generating material, a sand mill was prepared by mixing 15 parts by weight of hydroxygallium phthalocyanine obtained in Synthesis Example 1, 10 parts by weight of vinyl chloride vinyl acetate copolymer resin (VMCH, Nippon Unicar) and 300 parts by weight of n-butyl alcohol. For 4 hours. This solution was dip-coated on the intermediate layer and dried to form a charge generation layer having a layer thickness of 0.2 μm. Next, 4 parts by weight of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine as a charge transporting material and binding 6 parts by weight of bisphenol Z polycarbonate resin (viscosity average molecular weight: 20,000) as a resin was dissolved by adding 80 parts by weight of chlorobenzene. By applying this solution onto the charge generation layer using a dip coating apparatus, a drying process is performed at 110 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 15 μm, and a photosensitive member comprising three layers. Was made.

  Using the obtained photoreceptor, an image forming apparatus having the same configuration as the image forming apparatus shown in FIG. 1 was produced. The produced image forming apparatus includes a contact charging device and an intermediate transfer device, and has the same configuration as that of the full color printer Documentor Color C400 manufactured by Fuji Xerox Co., Ltd. except for the photoreceptor.

  In the image forming apparatus thus obtained, the charging potential is set to 700 V, the low speed mode (time from charging to development: 300 msec), the normal mode (time from charging to development: 200 msec), the high speed mode (charging) The print test was performed in each mode of time from development to development: 100 msec. The obtained results are shown in Table 2.

(Example 2)
100 parts by weight of zinc oxide (product made by Teika, average particle size 70 nm, specific surface area value 15 m ² / g) is stirred and mixed with 500 parts by weight of toluene, and a silane coupling agent (KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.25 Part by weight was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 2 hours to obtain a surface-treated zinc oxide pigment.

  Next, 60 parts by weight of a surface-treated zinc oxide pigment, 13.5 parts by weight of blocked isocyanate (Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co.) as a curing agent, and butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) 15 parts by weight were dissolved in 85 parts by weight of methyl ethyl ketone. 38 parts by weight of this solution and 25 parts by weight of methyl ethyl ketone were mixed, and dispersion treatment was performed for 2 hours with a sand mill using 1 mmφ glass beads. To the obtained dispersion, 0.005 part by weight of dioctyltin dilaurate as a catalyst and 3.4 parts by weight of silicone resin particle Tospearl 145 (manufactured by GE Toshiba Silicone) are added to obtain a liquid for coating an undercoat layer. It was. This coating solution was applied onto an aluminum substrate having a length of 404 mm, an inner diameter of φ28 mm, and an outer diameter of φ30 mm by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 25 μm.

  Next, a charge generation layer was formed in the same manner as in Example 1.

  Next, 1 part by weight of tetrafluoroethylene resin particles and 0.02 part by weight of a fluorine-based graft polymer were sufficiently mixed together with 5 parts by weight of tetrahydrofuran and 2 parts by weight of toluene to obtain a tetrafluoroethylene resin particle suspension. . Next, 4 parts by weight of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine as a charge transport material, bisphenol Z-type polycarbonate resin ( Viscosity average molecular weight 40,000) 6 parts by weight, tetrahydrofuran 23 parts by weight, toluene 10 parts by weight After mixing and dissolving, the tetrafluoroethylene resin particle suspension is added and mixed with stirring, and then fine penetration is achieved. Using a high-pressure homogenizer (trade name: LA-33S, manufactured by Nanomizer Co., Ltd.) equipped with a pressure chamber, the dispersion treatment with the pressure increased to 400 kgf / cm 2 was repeated 6 times to obtain a tetrafluoroethylene resin particle dispersion. Further, 0.2 parts by weight of 2,6-di-t-butyl-4-methylphenol was mixed to obtain a coating solution for forming a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 25 μm, thereby obtaining the intended photoreceptor. Further, an image forming apparatus was produced and a print test was performed in the same manner as in Example 1 except that the obtained photoreceptor was used. The obtained results are shown in Table 2.

(Example 3)
A photoconductor was prepared in the same manner as in Example 1 except that the chlorogallium phthalocyanine obtained in Synthesis Example 2 was used in place of the hydroxygallium phthalocyanine obtained in Synthesis Example 1. Further, an image forming apparatus was produced and a print test was performed in the same manner as in Example 1 except that the obtained photoreceptor was used. The obtained results are shown in Table 2.

(Comparative Example 1)
A photoconductor was prepared in the same manner as in Example 3 except that the hydroxygallium phthalocyanine obtained in Synthesis Example 3 was used instead of the hydroxygallium phthalocyanine obtained in Synthesis Example 1. Further, an image forming apparatus was produced and a print test was performed in the same manner as in Example 1 except that the obtained photoreceptor was used. The obtained results are shown in Table 2.

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 an example of an electrophotographic photoreceptor according to the present invention. 2 is a graph showing an X-ray diffraction spectrum of hydroxygallium phthalocyanine obtained in Synthesis Example 1. FIG. 2 is a graph showing a spectral absorption spectrum of hydroxygallium phthalocyanine obtained in Synthesis Example 1. FIG. 2 is a TEM photograph (magnification: 700 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 1. FIG. 2 is a TEM photograph (magnification: 6,000 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 1. FIG. 4 is a TEM photograph (magnification: 30,000 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 1. FIG. 6 is a graph showing an X-ray diffraction spectrum of chlorogallium phthalocyanine obtained in Synthesis Example 2. 6 is a graph showing a spectral absorption spectrum of chlorogallium phthalocyanine obtained in Synthesis Example 2. 4 is a TEM photograph (magnification: 700 times) of chlorogallium phthalocyanine obtained in Synthesis Example 2. 4 is a TEM photograph (magnification: 6,000 times) of chlorogallium phthalocyanine obtained in Synthesis Example 2. FIG. 4 is a TEM photograph (magnification: 30,000 times) of chlorogallium phthalocyanine obtained in Synthesis Example 2. FIG. 6 is a graph showing an X-ray diffraction spectrum of hydroxygallium phthalocyanine obtained in Synthesis Example 3. 6 is a graph showing the spectral absorption spectrum of hydroxygallium phthalocyanine obtained in Synthesis Example 3. 4 is a TEM photograph (magnification: 700 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 3. FIG. 4 is a TEM photograph (magnification: 6,000 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 3. FIG. 4 is a TEM photograph (magnification: 30,000 times) of hydroxygallium phthalocyanine obtained in Synthesis Example 3. FIG.

Explanation of symbols

  11, 11K, 11C, 11M, 11Y ... electrophotographic photosensitive member, 12K, 12C, 12M, 12Y ... developing unit, 13K, 13C, 13M, 13Y ... charging roll, 14K, 14C, 14M, 14Y ... primary transfer roll, 15K , 15C, 15M, 15Y ... exposure light, 16K, 16C, 16M, 16Y ... cleaning blade, 17 ... exposure device, 18 ... intermediate transfer member, 19 ... secondary transfer roll, 110 ... fixing device, 111 ... paper tray, 112 DESCRIPTION OF SYMBOLS: Transfer medium, 2 ... Conductive support, 3 ... Photosensitive layer, 4 ... Undercoat layer, 5 ... Charge generation layer, 6 ... Charge transport layer, 7 ... Protective layer.

Claims (11)

An image forming apparatus comprising an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit, and performing charging, exposing, developing, and transferring while moving an outer peripheral surface of the electrophotographic photosensitive member in a predetermined direction,
A control means for controlling the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so that the time required from charging to development is variable;
The electrophotographic photoreceptor has a conductive support and a photosensitive layer containing gallium phthalocyanine formed on the conductive support, and the maximum primary particle diameter of the gallium phthalocyanine is 0.3 μm or less. An image forming apparatus. A plurality of image forming units having an electrophotographic photosensitive member, a charging unit, an exposing unit, a developing unit, and a transferring unit, and charging and exposing while moving the outer peripheral surface of the electrophotographic photosensitive member in a predetermined direction in each of the image forming units. A color image forming apparatus for performing development and transfer,
Each of the image forming units further comprises a control means for controlling the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so that the time required from charging to development is variable,
Each of the electrophotographic photoreceptors has a photosensitive layer containing gallium phthalocyanine, and the maximum primary particle diameter of the gallium phthalocyanine is 0.3 μm or less. The control means controls the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so as to satisfy the conditions represented by the following formulas (1) and (2), and includes a plurality of modes including a normal mode, a low speed mode, and a high speed mode. The image forming apparatus according to claim 1, wherein the control mode can be switched.
T _low ≧ (1/3) T (1)
T _high ≦ 3T (2)
(In the formula, T represents the time required from charging to developing when performing the electrophotographic process in the normal mode, T _low represents the time required from charging to developing when performing the electrophotographic process in the _low speed mode, and T _high indicates the time required from charging to development when the electrophotographic process is performed in the _high- speed mode.) The image forming apparatus according to claim 1, wherein the gallium phthalocyanine is hydroxygallium phthalocyanine or chlorogallium phthalocyanine. 5. The image according to claim 1, wherein the gallium phthalocyanine is hydroxygallium phthalocyanine having an absorption at a peak of 810 to 839 nm in a spectral absorption spectrum in the range of 600 to 900 nm. Forming equipment. The image forming apparatus according to claim 5, wherein the hydroxygallium phthalocyanine has a specific surface area value of 45 m ² / g or more according to a BET method. 6. The hydroxygallium phthalocyanine has diffraction peaks at least at a Bragg angle (2θ ± 0.2 °) of 7.5 ° and 28.3 ° with respect to a CuKα characteristic X-ray. Or the image forming apparatus according to 6; 5. The gallium phthalocyanine according to claim 1, wherein the gallium phthalocyanine is a chlorogallium phthalocyanine having an absorption at 770 to 790 nm at a maximum peak in a range of 600 to 900 nm in a spectral absorption spectrum. Image forming apparatus. 9. The image forming apparatus according to claim 1, wherein the charging unit is a contact charging device that contacts the electrophotographic photosensitive member to charge the electrophotographic photosensitive member. . The transfer means has a configuration employing an intermediate transfer system in which a toner image formed on the outer peripheral surface of the electrophotographic photosensitive member is transferred to the transfer medium via an intermediate transfer member. The image forming apparatus according to any one of claims 1 to 9. An electrophotographic photosensitive member and at least one selected from a charging unit, a developing unit, a transfer unit, and a cleaning unit, and charging, exposing, developing, and transferring while moving the outer peripheral surface of the electrophotographic photosensitive member in a predetermined direction A process cartridge detachable from an image forming apparatus for performing
A control means for controlling the moving speed of the outer peripheral surface of the electrophotographic photosensitive member so that the time required from charging to development is variable;
The electrophotographic photoreceptor has a conductive support and a photosensitive layer containing gallium phthalocyanine and a binder resin formed on the conductive support, and the maximum primary particle diameter of the gallium phthalocyanine is 0.00. A process cartridge having a size of 3 μm or less.

Images