JP2005266532A - Picture forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a picture forming device with which high picture quality is realized even in the case a self-scanning LED is equipped as an exposure light source. <P>SOLUTION: The picture forming device 100 is equipped with: an electrophotographic photoreceptor 106 which has a conductive supporting body and a photosensitive layer formed on the conductive supporting body; an electrifying device 108 which electrifies the electrophotographic photoreceptor 106; an exposing device 110 which exposes the electrified electrophotographic photoreceptor 106 and makes it form an electrostatic latent image; a developing device 116 which develops the electrostatic latent image with a toner and makes it form a toner image; and a transferring device 120 which transfers the toner image from the electrophotographic photoreceptor 106 to a medium to be transferred, and the device 100 is characterized by having the electrophotographic photoreceptor 106 with a protective layer on the photosensitive layer and having the exposing device 110 equipped with the self-scanning LED as the exposure light source. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus.

  In an image forming apparatus such as an electrophotographic printer, a copying machine, and a facsimile, an LED print head (LPH) using an LED as a light source is used as a print head.

In recent years, an image forming apparatus using a self-scanning LED (SLED) as an LED print head has been proposed (for example, see Patent Document 1). The self-scanning LED employs a thyristor structure as a portion corresponding to a switch portion that selectively turns on and off the light emitting point. By applying this thyristor structure, the self-scanning LED is a light emitting light source array in which the switch portion can be arranged on the same chip as the light emitting point. In addition, since the self-scanning LED can selectively emit light by using two signal lines at the on / off timing of the switch, the data line can be shared and the wiring can be simplified.
JP-A-2-263668

  However, the self-scanning LED has a light emission time of each light emitting point per dot that is limited to a fraction of the number of light emitting points per chip, and its light emission time is shorter than an LED that can emit light continuously. Few. Specifically, when 256 light-emitting points are formed on one chip and light is emitted sequentially by self-scanning, the light emission time is less than 1/256 compared to an LED that can emit light continuously.

  Thus, in an image forming apparatus including a self-scanning LED as an exposure light source, the amount of light on the electrophotographic photosensitive member tends to be insufficient, and it is difficult to achieve high image quality.

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an image forming apparatus capable of realizing high image quality even when a self-scanning LED is provided as an exposure light source. And

  In an image forming apparatus using a self-scanning LED as an exposure light source, the amount of light on the electrophotographic photosensitive member is likely to be insufficient. Therefore, it is preferable to make the photosensitive layer thin in order to improve image quality. However, when the photosensitive layer is made thinner, the electrophotographic photosensitive member is subjected to potential fluctuations and sensitivity fluctuations, particularly low sensitivity due to wear of the photosensitive layer due to repeated use, and the deterioration of image quality becomes remarkable.

  On the other hand, if the photosensitive layer is made thicker in order to reduce the influence of wear, charges are dissipated during charge transfer, resulting in disturbance of the latent image, resulting in a decrease in resolution and image quality.

  Therefore, the present inventors have found that the above problem can be solved by improving the wear resistance by providing a specific functional layer on the electrophotographic photosensitive member so that the electrophotographic characteristics of the electrophotographic photosensitive member are not reduced. The headline and the present invention were completed.

That is, the first image forming apparatus of the present invention includes an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, a charging device for charging the electrophotographic photosensitive member, An exposure device that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, a developing device that develops the electrostatic latent image with toner to form a toner image, and the toner image to the electrophotographic photosensitive member. A transfer device for transferring from a body to a transfer medium, the electrophotographic photoreceptor has a protective layer on the photosensitive layer, and the exposure device has a self-scanning LED as an exposure light source. It is characterized by.

  According to the first image forming apparatus of the present invention, when the electrophotographic process is performed, the abrasion of the photosensitive layer can be suppressed without increasing the thickness of the photosensitive layer of the electrophotographic photosensitive member, and potential fluctuation and sensitivity fluctuation can be sufficiently prevented. Can be prevented. In such an electrophotographic photosensitive member, the electrophotographic characteristics can be maintained at a high level, and high image quality can be achieved even when a self-scanning LED is used as an exposure light source.

  In the first image forming apparatus of the present invention, the characteristic of the self-scanning LED that the variable light quantity is small and the control width is narrow is complemented, and the occurrence of film thickness unevenness due to wear is suppressed. Therefore, even after the light amount correction of each light emitting element, even after long-term repeated use, the occurrence of vertical stripe-like density unevenness can be suppressed, so that in addition to high image quality, high speed and long life can be achieved at the same time.

  A second image forming apparatus according to the present invention includes an electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, a charging device for charging the electrophotographic photosensitive member, and charging. An exposure device that exposes the electrophotographic photoreceptor to form an electrostatic latent image, a developing device that develops the electrostatic latent image with toner to form a toner image, and the toner image from the electrophotographic photoreceptor. A transfer device for transferring to a transfer medium, wherein the electrophotographic photosensitive member is selected from the group consisting of a fluororesin, a silicone resin, and a polyolefin resin on the side of the photosensitive layer farthest from the conductive support. The exposure apparatus includes a self-scanning LED as an exposure light source.

  In the second image forming apparatus of the present invention, since the specific electrophotographic photosensitive member is used, it is possible to sufficiently suppress the progress of abrasion of the photosensitive layer that occurs in the repeated processes of charging, exposure, development and transfer in the electrophotographic process. And high image quality can be achieved. In addition, it is possible to sufficiently prevent potential fluctuations and sensitivity fluctuations of the electrophotographic photosensitive member that are manifested when a self-scanning LED is used, and it is possible to sufficiently suppress deterioration in image quality. Further, the characteristic of the self-scanning LED that the variable light quantity is small and the control width is narrow is complemented. Furthermore, according to the image forming apparatus of the present invention, it is possible to reduce the thickness of the photosensitive layer of the electrophotographic photosensitive member, which is useful for downsizing of the apparatus, and image quality due to the diffusion of electric charges when forming an electrostatic latent image. Can be sufficiently suppressed. Therefore, in the image forming apparatus of the present invention, in addition to high image quality, high speed and small size of the apparatus can be easily realized, and a good quality image can be obtained even if the image forming process is repeated over a long period of time. it can.

  According to the first and second image forming apparatuses of the present invention, it is possible to realize high image quality while applying a self-scanning LED as an exposure light source.

  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 a preferred embodiment of an image forming apparatus of the present invention. Here, the first image forming apparatus and the second image forming apparatus of the present invention have the same configuration as that of the image forming apparatus 100 except that the electrophotographic photosensitive member to be mounted is different.

  The image forming apparatus 100 is covered with a casing 102, and the upper surface of the image forming apparatus 100 also serves as the discharge tray unit 104. In the casing 102, an electrophotographic photosensitive member 106 is disposed at the center thereof. Around the electrophotographic photosensitive member 106, there is a charging device 108 for uniformly charging the surface of the electrophotographic photosensitive member 106 in a counterclockwise direction immediately above and slightly to the right, and a self-scanning LED as an exposure light source as an exposure device. A light source array 110, a developing device 116, an intermediate transfer belt 122, and a cleaning device 124 using (hereinafter referred to as “SLED”) are disposed.

  Here, the first electrophotographic photosensitive member mounted on the first image forming apparatus has a conductive support and a photosensitive layer formed on the conductive support, and is protected on the photosensitive layer. Has a layer. The second electrophotographic photosensitive member mounted on the second image forming apparatus has a conductive support and a photosensitive layer formed on the conductive support, and the conductive support of the photosensitive layer is provided. A layer containing at least one selected from the group consisting of a fluororesin, a silicone resin, and a polyolefin resin is provided on the side farthest from the body. The details of the first electrophotographic photosensitive member and the second electrophotographic photosensitive member will be described later.

  The developing device 116 is equipped with a toner tank 112 for each color of cyan (C), magenta (M), yellow (Y), and black (K), and rotates to sequentially transfer the toner rolls 114 for each color to the electrophotographic photosensitive member. 106 is a rotary developing device that can be made to correspond to 106. The intermediate transfer belt 122 is wound around a plurality of rollers 120 and driven in the direction of arrow A in FIG. 1, and functions as a primary (intermediate) transfer member.

  When the toner image formed on the outer peripheral surface of the electrophotographic photosensitive member 106 is transferred to the intermediate transfer belt 122 by the developing device 116, the lubricant is supplied to the outer peripheral surface of the electrophotographic photosensitive member 106 by the lubricant supplying device. A region of the outer peripheral surface carrying the transferred toner image is cleaned by the cleaning device 124. The lubricant supply device may be provided integrally with the cleaning device 124 or may be provided separately.

  A lower end portion of the intermediate transfer belt 122 is a part of a conveyance path of an image forming sheet (hereinafter simply referred to as “sheet”) 126, and the sheet 126 includes an intermediate transfer belt 122, a roller 118, and the lower end portion. It is nipped and conveyed between the two.

  A plurality of rollers 118 are arranged in the conveyance path of the sheet 126, and the uppermost sheet 126 stacked on the sheet feeding tray 128 is taken out by the sheet feeding device 130, and comes into contact with the lower end portion of the intermediate transfer member 124. The sheet is conveyed and sent out to the discharge tray section 104 via the fixing section 132.

  A density sensor 134 is provided at a position facing a part of the conveyance path of the intermediate transfer belt so as to detect the density of, for example, a test patch (color and density sample). Next, the light source array 110 will be described in detail.

  As shown in FIG. 2, the light source array 110 further includes a plurality of LED arrays (light emitting element arrays) 152 in which a plurality of chip-shaped LEDs 150 are arranged in series along the axial direction of the electrophotographic photosensitive member 106. It is composed of that. The light emitting points of the LEDs 150 are preferably arranged in a staggered manner. The light source array 110 is controlled to be turned on by a drive circuit 156 (see FIG. 3) controlled in the same casing 154, and scans a light beam according to image data.

  FIG. 3 shows details of the drive circuit 156 of the light source array 110. The drive circuit 156 is basically a combination of a single drive circuit shown in FIG. Here, the detailed description of the thyristor 10 and the like is omitted.

  As a trigger for turning on the SLED, the voltage VS is applied to the point P1 (the number following the point P indicates the order of the plurality of LEDs arranged) via the resistor 158. All the points P (1 to N (N is a positive integer)) including the point P1 are connected to the base line 161 via the resistor 160, respectively. The base line 161 maintains a predetermined voltage in the first stage, and is set to a potential (Φga) that decreases by a predetermined potential (Vf) as it goes to each stage.

  Further, the point P (1 to N) is connected to the anode side of the LED 150. The cathode side of the LED 150 is connected to a gradation signal line 163 described later.

  Here, as shown in FIG. 4, the driving circuit of Φga is driven at a constant current upon receiving a light quantity instruction value from an APC (auto power control) 162 based on a detection signal from the density sensor 134. (Constant current drive circuit). That is, the light quantity instruction value is converted into an analog value by the DA converter 164 and connected to the negative side input terminal of the first comparator 168 via the resistor 166. The positive side input terminal of the first comparator 168 is grounded (GND). The output terminal of the first comparator 168 and the negative input terminal are connected via a resistor 170. As a result, the output of the first comparator 168 changes depending on the light quantity instruction value and becomes a predetermined voltage.

  Here, this output voltage is connected to the positive input terminal of the second comparator 172, the negative input terminal is connected to the reference voltage source VSS via the resistor 174, and the output terminal of the second comparator 172 is further connected. Is connected to the MOS transistor 176, a constant current flows through the MOS transistor 176.

  In FIG. 4, the driving circuit of Φga is the constant current driving circuit 178, but a constant voltage driving circuit 180 as shown in FIG. 5 may be used. Since the circuit configuration only needs to use the output of the first comparator 168 in FIG. 4, the same reference numerals are given and description of the configuration is omitted.

  As shown in FIG. 3, the emitter of the odd-numbered transistor Q2 is connected to the first control line (V1) 182, and the emitter of the even-numbered transistor Q2 is connected to the second control line (V2) 184. Yes. The point P (1 to N) of each stage is connected to one end of the LED 150, and the other end of the LED 150 is connected to a gradation signal line 163 that outputs a pulse wave that is a gradation signal of each stage. . When the gradation signal line 163 is at a low level (L), the LED is lit if the point P (1 to N) is at a predetermined potential.

  FIG. 6 shows a circuit 200 for generating a pulse waveform sent to the gradation signal line 163. The gradation signal (12 bits) output from the image processing unit 202 is input to the integrator 204. For example, the image processing unit 202 converts images in various formats sent from a recording medium, a communication line, or the like into a format corresponding to the image forming apparatus 100 of the present embodiment. Correction data (4 bits) held in the correction data holding unit 206 is also input to the accumulator 204, and unevenness of the light emission point of each LED 150 is corrected.

  The corrected gradation signal with the correction data added by the integrator is converted into an analog signal by the DA converter 208 (density signal), and the plus of the comparator 210 is input to the input terminal.

  On the other hand, branch lines 182A and 184A are connected to the control signal lines V1 (Φ1) and V2 (Φ2) output from the timing generator 212, respectively, and these branch lines 182A and 184A are input to the OR circuit 186. For this reason, the output of the OR circuit 186 is active when either one of V1 and V2 is active (here, low level). In synchronization with this active time, the triangular wave generation circuit 188 generates a triangular wave and inputs it to the negative side input terminal of the comparator 210.

  This operation is shown in the time chart of FIG. That is, a triangular wave is formed according to a signal obtained by ORing V1 (Φ1) and V2 (Φ2). At this time, a space a is generated between the triangular waves, and this becomes an interval for sequentially lighting one by one at the lighting timing of the odd-numbered LED and the even-numbered LED.

  By superimposing the density signal on this triangular wave, the range of the level higher than the density signal in the triangular wave becomes the actual lighting time, and a pulse waveform to be sent to the gradation signal line 163 can be generated.

  FIG. 8 is an operation timing chart of the LED drive circuit of FIG. 3, and FIG. 9 is a characteristic diagram showing the LED light emission state of the LED drive circuit of FIG. Here, the details are omitted.

  Next, the charging device 108 will be described in detail. As the charging method of the charging device 108, a conventionally known non-contact method using a corotron or a scorotron can be preferably employed. However, in order to reduce the size of the image forming apparatus, it is desirable to use a roll-type contact charger. Since the image forming apparatus 100 uses the specific electrophotographic photosensitive member 106, the image forming apparatus 100 exhibits particularly excellent durability even when contact charging with a large stress on the electrophotographic photosensitive member 106 is used.

  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 supporting them, and a core material from the outside. Furthermore, a protective layer can be provided outside the resistance layer as necessary.

  The roller-shaped member rotates at the same peripheral speed as the electrophotographic photosensitive member 106 by contacting the electrophotographic photosensitive member 106 without any driving means, and functions as a charging means. However, some driving means may be attached to the roller member and rotated at a peripheral speed different from that of the electrophotographic photosensitive member 106 to be charged.

  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 or the like are dispersed can be used. The material of the elastic layer has conductivity or semiconductivity, and generally is a material in which conductive particles or semiconductive particles are dispersed in a rubber material.

  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, etc. 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, and 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 thereof is controlled. The resistivity is preferably 10 ³ to 10 ¹⁴ Ω · cm, More preferably, 10 ⁵ to 10 ¹² Ω · cm, and even more preferably 10 ⁷ to 10 ¹² Ω · cm. Moreover, as a film thickness, Preferably it is 0.01-1000 micrometers, More preferably, it is 0.1-500 micrometers, More preferably, 0.5-100 micrometers is good.

  Binder resins include 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 Polyolefin resin such as PET, 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. Further, if necessary, an antioxidant such as hindered phenol and hindered amine, a filler such as clay and kaolin, and a lubricant such as silicone oil can be added.

  As a means for forming these layers, a blade coating method, a 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.

  When the electrophotographic photosensitive member 106 is charged 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. When the AC voltage is superimposed, the peak-to-peak voltage is preferably 400 to 1800 V, more preferably 800 to 1600 V, and still more preferably 1200 to 1600 V. The frequency of the alternating voltage is preferably 50 to 20,000 Hz, preferably 100 to 5,000 Hz.

  The developer used in the developing device 116 may be either a one-component system or a two-component system, and may be either a regular developer or a reversal developer.

  Further, the image forming apparatus 100 may transfer the toner image on the electrophotographic photosensitive member 106 directly to the paper 126. After the toner image on the electrophotographic photosensitive member 106 is transferred to the intermediate transfer member, the image forming apparatus 100 further includes: An intermediate transfer method of transferring to a transfer medium may be used. As the intermediate transfer member, the belt-shaped intermediate transfer belt 122 is used as the intermediate transfer member in the image forming apparatus 100 shown in FIG. 1, but a drum-shaped intermediate transfer member may be used.

  Further, the image forming apparatus 100 shown in FIG. 1 may include a process cartridge configured to include at least the electrophotographic photosensitive member 106. By using such a process cartridge, maintenance can be performed more easily.

  Next, the first electrophotographic photosensitive member mounted on the first image forming apparatus will be described in detail. 11 to 12 are schematic sectional views showing examples of the first electrophotographic photosensitive member. The electrophotographic photosensitive member shown in FIG. 11 includes a photosensitive layer 3 whose functions are separated into a layer containing a charge generating material (charge generating layer 5) and a layer containing a charge transporting material (charge transporting layer 6). It is. In FIG. 12, the charge generation material and the charge transport material are contained in the same layer (single-layer type photosensitive layer 8). The photosensitive layer may basically have a single layer structure or a laminated structure in which the functions of the charge generation layer 5 and the charge transport layer 6 are separated. In the case of a laminated structure, the charge generation layer 5 and the charge transport layer 6 may be laminated in any order.

  The electrophotographic photoreceptor 1 shown in FIG. 11 has a structure in which an undercoat layer 4, a charge generation layer 5, a charge transport layer 6, and a protective layer 7 are sequentially laminated on a conductive support 2. Further, the electrophotographic photoreceptor 1 shown in FIG. 12 has a structure in which an undercoat layer 4, a single-layer type photosensitive layer 8, and a protective layer 7 are sequentially laminated on a conductive support 2. The electrophotographic photosensitive member 1 may not have the undercoat layer 4.

  Hereinafter, the first electrophotographic photosensitive member according to the present invention will be described in detail with reference to FIG.

  Examples of the conductive support 2 include metals such as aluminum, nickel, chromium, and stainless steel; a plastic film provided with a thin film such as aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, and ITO. Etc .; Paper and plastic film coated with or impregnated with a conductivity-imparting agent, etc. These conductive supports may have any shape such as a drum shape, a sheet shape, and a plate shape.

  Further, when a metal pipe is used as the conductive support 2, even if the surface remains as a raw pipe, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, and coloring treatment are performed in advance. Etc. may be performed. By roughening the surface of the metal pipe, it is possible to prevent grain-like density spots caused by interference light in the photoconductor that may occur when a coherent light source is used.

  The undercoat layer 4 prevents the injection of charges from the conductive support 2 to the photosensitive layer 3 when the photosensitive layer 3 having a laminated structure is charged, and the photosensitive layer 3 is integrated with the conductive support 2. Thus, it is possible to add an action as an adhesive layer that is bonded and held, or in some cases, an antireflection effect of light of the conductive 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. Examples thereof include polymer resin compounds such as resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, and melamine resin. Furthermore, known materials such as a zirconium chelate compound, a titanium chelate compound, an aluminum chelate compound, a titanium alkoxide compound, an organic titanium compound, and a silane coupling agent can also be used.

  In addition, a charge transporting resin having a charge transporting group, a conductive resin such as polyaniline, or the like can be used. These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds. Of these, resins insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used. Further, zirconium chelate compounds and silane coupling agents are excellent in performance, such as low residual potential, little potential change due to environment, and little potential change due to repeated use.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, 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.

  Particularly preferred silane coupling agents are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N -Phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and the like.

  Examples of the zirconium chelate compound 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 the titanium chelate compound 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 contain a conductive material in order to improve the photoreceptor characteristics. Examples of the conductive material include metal oxides such as titanium oxide, zinc oxide, and tin oxide, and any known material can be used as long as desired photoreceptor characteristics can be obtained.

  The metal oxide can be subjected to a surface treatment. By performing the surface treatment, resistance value control, dispersibility control, and improvement in photoreceptor characteristics can be achieved. As the surface treatment agent, known materials such as a zirconium chelate compound, a titanium chelate compound, an aluminum chelate compound, a titanium alkoxide compound, an organic titanium compound, and a silane coupling agent can be used. These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds. Among them, the silane coupling agent is excellent in performance such as low residual potential, little potential change due to environment, little potential change due to repeated use, and excellent image quality characteristics.

  Examples of the silane coupling agent, zirconium chelate compound, titanium chelate compound, and aluminum chelate compound include the same substances as those described above.

  As the surface treatment method, any known method can be used, but a dry method or a wet method can be used.

  When surface treatment is performed by a dry method, a silane coupling agent dissolved directly or in an organic solvent is dropped and sprayed with dry air or nitrogen gas while stirring the metal oxide fine particles with a mixer having a large shearing force. Can be processed uniformly. The addition or spraying is preferably performed at a temperature below the boiling point of the solvent. When spraying at a temperature equal to or higher than the boiling point of the solvent, the solvent evaporates before being uniformly stirred, and the silane coupling agent tends to locally accumulate, making uniform treatment difficult. 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.

  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 stirring or dispersing a silane coupling agent solution, the solvent is removed. Uniformly processed. The solvent is distilled off by distillation. In the removal method by filtration, unreacted silane coupling agent tends to flow out, and the amount of silane coupling agent for obtaining desired characteristics tends to be difficult to control. 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. In the wet method, in order to remove moisture contained in the metal oxide fine particles, a method of removing with stirring and heating in a solvent used for surface treatment or a method of removing by azeotropy with a solvent can be applied. .

  The amount of the silane coupling agent relative to the metal oxide fine particles in the undercoat layer 4 may be any amount as long as desired electrophotographic characteristics can be obtained.

  The ratio of the metal oxide fine particles and the resin used in the undercoat layer 4 can be arbitrarily set as long as desired electrophotographic characteristics can be obtained.

  Various organic or inorganic fine powders can be mixed in the undercoat layer 4 for the purpose of improving light scattering properties. In particular, white pigments such as titanium oxide, zinc oxide, zinc sulfide, lead white and lithopone, inorganic pigments as extender pigments such as alumina, calcium carbonate and barium sulfate, polytetrafluoroethylene resin particles, benzoguanamine resin particles, styrene resin particles Etc. are effective. The particle diameter of the added fine powder is preferably 0.01 to 2 μm. Although fine powder is added as needed, when added, it is 10-80 mass% by mass ratio with respect to the solid content whole quantity of the undercoat layer 4, More preferably, 30-70 mass% is added.

  The undercoat layer 4 can be formed by applying a coating solution for forming an undercoat layer in which the above-described material is dissolved and / or dispersed in a predetermined solvent on a conductive support and drying.

  Various additives can be used in the coating liquid for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality.

  Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra- It is also effective to include an electron transporting substance such as a diphenoquinone compound such as t-butyldiphenoquinone, an electron transporting pigment such as a polycyclic condensation system or an azo group. Any known electron transporting substance or electron transporting pigment can be used.

  In the preparation of the coating solution for forming the undercoat layer, when a fine powder such as a conductive substance or a light scattering substance as described above is mixed, a dispersion treatment is performed by adding the fine powder to the solution in which the resin component is dissolved. . As a method for dispersing the fine powder in the resin, methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Further, as the coating method used when the undercoat layer 4 is provided, the blade coating method, the wire bar coating method, the spray coating method, the dip coating method, the bead coating method, the air knife coating method, the curtain coating method and the like are used. The method can be used.

  The thickness of the undercoat layer 4 is preferably 0.01 to 50 μm, more preferably 0.05 to 30 μm.

  Next, the charge generation layer 5 will be described. The charge generation layer 5 includes a known charge generation material and a binder resin.

  The binder resin can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin. Insulating resins such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be mentioned, but are not limited thereto. These binder resins can be used alone or in combination of two or more.

  Any known charge generating material can be used, but metal and metal-free phthalocyanine pigments are particularly preferred. Among these, hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin phthalocyanine, and titanyl phthalocyanine having specific crystals are particularly preferable.

  The charge generation layer 5 can be formed by applying a charge generation layer forming coating solution in which the above-described materials are dissolved and / or dispersed in a predetermined solvent on the conductive support 2 and drying.

  The blending ratio (mass ratio) of the charge generating material and the binder resin in the charge generating layer forming coating solution is preferably in the range of 10: 1 to 1:10. In addition, as a method for dispersing these, usual methods such as a ball mill dispersion method, an attritor dispersion method, and a sand mill dispersion method can be used. At this time, a condition that the crystal type does not change due to dispersion is required. Further, at the time of this dispersion, it is effective that the particles have a particle size of preferably 0.5 μm or less, more preferably 0.3 μm or less, and further preferably 0.15 μm or less.

  Further, pigment dispersion stability, pigment treated with a compound represented by the formula (I-1) described later for the purpose of increasing photosensitivity or stabilizing electrical properties may be used, It may be added to the pigment dispersion.

  Moreover, as a solvent used for these dispersions, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, Ordinary organic solvents such as tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used alone or in admixture of two or more.

  In addition, as a coating method used when the charge generation layer 5 is provided, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used.

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

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

  As the binder resin, 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, silicon-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole, polysilane, Polyester-based charge transporting polymers disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used.

  The charge transport layer 6 is formed by applying a charge transport layer forming coating solution obtained by dissolving and / or dispersing the charge transport material and the binder resin in a predetermined solvent on the charge generation layer 5 and drying with hot air. can do.

  Furthermore, as a solvent used when providing the coating liquid for forming the charge transport layer, aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, methylene chloride, chloroform and chloride Usual organic solvents such as halogenated aliphatic hydrocarbons such as ethylene and cyclic or linear ethers such as tetrahydrofuran and ethyl ether can be used alone or in admixture of two or more.

  As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used.

  The film thickness of the charge transport layer 6 is preferably 5 to 50 μm, more preferably 15 to 35 μm.

  Add additives such as antioxidants, light stabilizers, heat stabilizers, etc. to the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light / heat generated in the electrophotographic apparatus. be able to. 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, benzoazole, dithiocarbamate, and tetramethylpipen.

Next, the protective layer 7 will be described. The protective layer 7 includes a binder resin, and preferably includes a three-dimensionally cross-linked silicon resin containing at least one charge transporting compound. In particular, the charge transporting organic compound represented by the general formula (I-1) is used. A cured film made of one or more of silicon compounds is preferred because of its excellent strength.
F [−D−A] _b (I-1)
Here, in formula (I-1), F represents an organic group derived from a charge transporting compound, D represents a divalent group (flexible subunit), and A represents Si (OR ² ) _a. (R ¹ ) A hydrolyzable substituted silicon group represented by _3-a is represented, and b represents an integer of 1 to 4. However, R ¹ represents one selected from the group consisting of a hydrogen atom, an alkyl group, and a substituted or unsubstituted aryl group, R ² represents hydrogen, an alkyl group, and selected from the group consisting of trialkylsilyl group 1 Represents a seed, and a represents an integer of 1 to 3.

  Note that the charge transporting compound represented by F is a photofunctional compound (a compound having a photocarrier transporting ability composed of holes or electrons).

  In the general formula (I-1), the organic group represented by F is not particularly limited as long as it has a photocarrier transport ability composed of holes or electrons, and has a conventional charge transport material. What is necessary is just to have a structure as it is. Specifically, a skeleton of a compound having a hole transporting property such as a triarylamine compound, a benzidine compound, an arylalkane compound, an aryl-substituted ethylene compound, a stilbene compound, an anthracene compound, or a hydrazone compound, and A compound having a skeleton of a compound having an electron transporting property such as a quinone compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, or an ethylene compound can be used.

In the general formula (I-1), when the substituted silicon group having hydrolyzability represented by —Si (OR ² ) _a (R ¹ ) _3-a is adjacent to another substituted silicon group, —Si -A cross-linking reaction is caused at the group portion, and -Si-O-Si- bonds in which oxygen atoms are cross-linked between adjacent -Si- groups are three-dimensionally formed. That is, this substituted silicon group plays a role of forming a so-called inorganic glassy network.

  In general formula (I-1), D is specifically responsible for linking the F portion for imparting photoelectric properties with A that contributes to the construction of a three-dimensional inorganic glassy network. Is a valent group. Further, D represents a structure that plays a role of imparting appropriate flexibility to the portion of the inorganic glassy network that is hard but brittle and improves the mechanical toughness of the film.

Specifically, D is a divalent hydrocarbon group represented by —C ₁ H _2l —, —C _m H _2m-2 —, or —C _n H _2n-4 — (wherein l is 1 to 15). represents an integer, m is an integer of 2 to 15, n represents an integer of 3~15), - COO -, - S -, - O -, - CH 2 -C 6 H 4 -, - n = CH—, — (C ₆ H ₄ ) — (C ₆ H ₄ ) —, and a characteristic group having a structure in which these characteristic groups are arbitrarily combined, and further, the constituent atoms of these characteristic groups are substituted with other substituents. And the like.

  In general formula (I-1), b is preferably 2 or more. When b is 2 or more, the charge transport material represented by the general formula (I-1) contains two or more Si atoms, so that an inorganic glassy network is easily formed, and mechanical strength is improved. To do.

  As a compound represented by general formula (I-1), the compound represented by the following general formula (I-2) is preferable. The compound represented by the following general formula (I-2) is a compound having a hole transporting ability (hole transporting material), and by incorporating this in the layer, the electrical properties and mechanical strength properties of the layer can be improved. Improvements can be made.

In general formula (I-2), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may be the same or different and each represents a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group. Or, it represents an arylene group, k represents 0 or 1, and 1 to 4 characteristic groups of Ar ^{1 to} Ar ⁵ have a structure represented by the following general formula (I-3).

—Y—Si (OR ² ) _a R ¹ _3-a (I-3)
In the general formula (I-3), a, ^{R 1} and ^{R 2} are a in each formula (I-1) in a ^{R 1} and ^{R 2} synonymous, Y represents a divalent group.

Here, Y is specifically a divalent hydrocarbon group represented by —C ₁ H _2l —, —C _m H _2m-2 —, or —C _n H _2n-4 — (where l is 1 Represents an integer of -15, m represents an integer of 2 to 15, and n represents an integer of 3 to 15), a substituted or unsubstituted divalent aryl group, -N = CH-, -O-, and , Represents a divalent group containing at least one selected from the group consisting of —COO—. Y may be a characteristic group having a structure in which divalent groups selected from the above groups are arbitrarily combined.

Ar ^{1 to} Ar ⁵ in the general formula (I-2) are preferably any of the following formulas (I-4) to (I-10).

Here, in formulas (I-4) to (I-10), R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkyl having 1 to 4 carbon atoms. 1 type chosen from the group which consists of a phenyl group substituted by a group or a C1-C4 alkoxy group, an unsubstituted phenyl group, and a C7-C10 aralkyl group. R ⁹ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. X represents a characteristic group having a structure represented by the general formula (I-3), m and s each represents 0 or 1, and t represents an integer of 1 to 3.

  Here, as Ar in Formula (I-10), what is represented by following formula (I-11) or (I-12) is preferable.

In formulas (I-11) and (I-12), R ¹⁰ and R ¹¹ have the same meanings as R ⁹ described above. T represents an integer of 1 to 3.

  Moreover, as Z in Formula (I-10), t is 0 among what is represented by following formula (I-11) and (I-12).

Moreover, as described above, in formulas (I-4) to (I-10), X represents a characteristic group having a structure represented by general formula (I-3). Y in the characteristic group is a divalent hydrocarbon group represented by -C ₁ H _21- , -C _m H _2m -2 or -C _n H _2n-4- (wherein, l represents an integer of 1 to 15, m represents an integer of 2 to 15, and n represents an integer of 3 to 15), -N = CH-, -O-, -COO-, -S -,-(CH) _β- (β represents an integer of 1 to 10), general formula (I-11) described above, general formula (I-12) described above, general formula (I- 13) and the characteristic group represented by (I-14).

Here, in formula (I-14), y and z each represent an integer of 1 to 5, t represents an integer of 1 to 3, and as described above, R ⁹ represents a hydrogen atom, a carbon number of 1 to 1 type chosen from the group which consists of a 4 alkyl group, a C1-C4 alkoxy group, and a halogen atom.

As described above, Ar ⁵ in formula (I-2) represents a substituted or unsubstituted aryl group or arylene group. When k = 0, formula (I-15) shown in Table 4 To (I-19) is preferable, and moreover, when k = 1, it is more preferable to apply to any of formulas (I-20) to (I-24) shown in Table 5.

Ar ⁵ in formula (I-2) is any one of formulas (I-15) to (I-19) shown in Table 4, and further formulas (I-20) to (I-20) shown in Table 5. In the case of taking any structure of -24), Z in the formulas (I-19) and (I-24) is selected from the group consisting of the following general formulas (I-25) to (I-32) It is preferable that it is 1 type.
_{- (CH 2) q - (} I-25)
_{- (CH 2 CH 2 O)} r - (I-26)

Here, in formulas (I-31) to (I-32), R ¹² and R ¹³ are each a group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a halogen atom. 1 represents a divalent group, q and r each represent an integer of 1 to 10, and t represents an integer of 1 to 2, respectively.

  W in the formulas (I-31) and (I-32) is preferably any one of divalent groups represented by the following (I-31) to (I-41). In formula (I-40), u represents an integer of 0 to 3.

—CH ₂ — (I-33)
_{-C (CH 3) 2 - ···} (I-34)
-O- (I-35)
-S- (I-36)
-C (CF ₃ ) _2- (I-37)
—Si (CH ₃ ) ₂ — (I-38)

  Furthermore, the charge transport material represented by the general formula (I-1) may be used alone or in combination of two or more. In addition to the charge transport material represented by the general formula (I-1), a compound represented by the following general formula (II) may be used in combination for the purpose of further improving the mechanical strength of the cured film.

B {−A} _γ (II)
Here, B represents a divalent organic group, and A represents a substituted silicon compound having hydrolyzability represented by Si (OR ² ) _a (R ¹ ) _3-a . The divalent organic group represented by B is at least one group selected from a divalent or higher valent hydrocarbon group, a divalent or higher valent phenyl group, and -NH-, which may include a branch, Or it consists of these combination. Further, the substituted silicon compound represented by A, a, a in ^{R 1} and ^{R 2} mentioned respective destination formula (I-1), has the same meaning as ^{R 1} and ^{R 2,} gamma 2 or more Represents an integer.

  The compound represented by the general formula (II) is a compound having a substituted silicon group having hydrolyzability described above. In the compound represented by the general formula (II), the moiety of the —Si— group contained in the substituted silicon group is a charge transport material represented by the general formula (I-1) or other adjacent general formula. It reacts with the substituted silicon group of the compound represented by (II) to form a three-dimensional bond of —Si—O—Si— in which oxygen atoms are bridged between adjacent —Si— groups. That is, a so-called inorganic glassy network is formed in the layer by a hydrolysis reaction that proceeds between substituted silicon groups of the compound represented by the general formula (II) and the charge transport material represented by the general formula (I-1). Is formed.

  The charge transport material represented by the general formula (I-1) can also form a cured film having an inorganic glassy network by itself as described above, but it is represented by the general formula (II). Since the resulting compound has two or more alkoxysilyl groups, it is considered that the crosslinked structure of the cured film is easily formed three-dimensionally and has higher mechanical strength. In addition, the compound represented by the general formula (II) becomes a constituent material of the cured film, so that it can be appropriately applied to the cured film in the same manner as the D portion in the charge transport material represented by the general formula (I-1). There is also a role to give flexibility.

As the compound represented by the general formula (II), those represented by the following general formulas (II-1) to (II-5) are preferable. In formulas (II-1) to (II-5), T ¹ and T ² each represent a divalent or trivalent hydrocarbon group that may be independently branched. A represents the substituted silicon group having hydrolyzability described above. h, i, and j each independently represent an integer of 1 to 3, and are selected so that the number of A in the compounds represented by Formulas (II-1) to (II-5) is 2 or more.

  The compounds (formulas (III-1) to (III-19)) which are preferred examples of the compound represented by the general formula (II) are shown below. In the following formulae, Me represents a methyl group, Et represents an ethyl group, and Pr represents a propyl group.

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

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

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

  A fluorine atom-containing compound can be added to the protective layer 7 for the purpose of imparting surface lubricity. By improving the surface lubricity, the friction coefficient between the photosensitive member and the cleaning member is lowered, and the wear resistance can be improved. In addition, it has an effect of preventing adhesion of discharge products, developer, paper dust, and the like to the surface of the photoreceptor, which is useful for improving the life of the photoreceptor.

  As the fluorine atom-containing compound, a fluorine atom-containing polymer such as polytetrafluoroethylene can be added as it is, or fine particles of these polymers can be added. Further, in the case of a cured film formed of the compound represented by the general formula (I-1), as the fluorine atom-containing compound, a compound capable of reacting with an alkoxysilane is added and configured as a part of the crosslinked film. desirable.

  Examples of such a fluorine atom-containing compound include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- ( Heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoro Examples include octyltriethoxysilane.

  The amount of the fluorine atom-containing compound added is preferably 20% by mass or less. Beyond this, a problem may occur in the film formability of the crosslinked cured film.

  The protective layer 7 has sufficient oxidation resistance, but an antioxidant may be added for the purpose of imparting stronger oxidation resistance. Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 15% by mass or less, and more preferably 10% by mass or less.

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

  The protective layer 7 is used for forming a known coating film, but other additives can also be added, and known materials such as a leveling agent, an ultraviolet absorber, a light stabilizer, and a surfactant can be used. Can be used.

  Also, a resin that dissolves in alcohol can be added for the purposes of discharge gas resistance, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like. Examples of resins soluble in alcohol solvents include polyvinyl butyral resins, polyvinyl formal resins, and polyvinyl acetal resins such as partially acetalized polyvinyl acetal resins in which a part of butyral is modified with formal or acetoacetal (for example, manufactured by Sekisui Chemical Co., Ltd.). ESREC B, K, etc.), polyamide resin, cellulose resin, phenol resin and the like. In particular, polyvinyl acetal resin is preferable in terms of electrical characteristics.

  The molecular weight of the resin is preferably 2000-100000, more preferably 5000-50000. If the molecular weight is less than 2000, the desired effect cannot be obtained. If the molecular weight is more than 100,000, the solubility becomes low and the addition amount is limited, or the film formation is poor at the time of coating. The addition amount is preferably 1 to 40%, more preferably 1 to 30%, and most preferably 5 to 20%. If it is less than 1%, the desired effect tends to be difficult to obtain, whereas if it exceeds 40%, image blurring tends to occur under high temperature and high humidity.

  In order to form the protective layer 7, a mixture of the above-described various materials and various additives is applied onto the photosensitive layer and subjected to heat treatment. Thereby, a cross-linking curing reaction is caused three-dimensionally to form a strong cured film. The temperature of the heat treatment is not particularly limited as long as it does not affect the underlying photosensitive layer, but is preferably set to room temperature to 200 degrees, particularly 100 to 160 degrees.

  In the formation of the protective layer 7, the crosslinking curing reaction may be performed without a catalyst, but it is preferable to use an appropriate catalyst. Catalysts include acid catalysts such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid and trifluoroacetic acid, bases such as ammonia and triethylamine, organotin compounds such as dibutyltin diacetate, dibutyltin dioctoate and stannous oxalate, tetra -Organic titanium compounds such as -n-butyl titanate and tetraisopropyl titanate, iron salts, manganese salts, cobalt salts, zinc salts, zirconium salts and aluminum chelate compounds of organic carboxylic acids.

  In order to make application | coating easy for the said coating liquid for protective layer formation, a solvent can be added and used as needed. Specifically, water, methanol, ethanol, n-propanol, i-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Ordinary organic solvents such as methylene chloride, chloroform, dimethyl ether and dibutyl ether can be used alone or in admixture of two or more.

  In the formation of the protective layer 7, as a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method should be used. Can do.

  The thickness of the protective layer 7 is preferably 0.5 to 20 μm, more preferably 2 to 5 μm.

  In addition, since the protective layer 7 has a function of a charge transport layer, the wear rate is 10 nm / kcycl or less in the image forming apparatus 100 from the viewpoint of reducing potential fluctuation and sensitivity fluctuation caused by photoconductor wear. It is preferable to be controlled, and it is more preferable to be controlled to 5 nm / kcycle or less.

  In the first electrophotographic photosensitive member, an undercoat layer is formed on a conductive support, and a photosensitive layer containing a charge generating material and a charge transporting material (separate function type or single layer type) may be used. ) And the protective layer are preferably 35 μm or less, and more preferably 25 μm or less. When this condition is satisfied, the resolution of the image forming apparatus 100 can be further improved.

  Next, the second electrophotographic photosensitive member mounted on the second image forming apparatus will be described in detail.

  FIG. 13 is a schematic cross-sectional view showing a preferred embodiment of the second electrophotographic photosensitive member. The electrophotographic photoreceptor shown in FIG. 13 includes a photosensitive layer 3 in which functions are separated into a layer containing a charge generation material (charge generation layer 5) and a layer containing a charge transport material (charge transport layer 6). It is. Note that even if the photosensitive layer basically includes a charge generation material and a charge transport material in the same layer (single layer structure), the function is separated into the charge generation layer 5 and the charge transport layer 6. It may be a laminated structure. In the case of a laminated structure, the charge generation layer 5 and the charge transport layer 6 may be laminated in any order.

  The electrophotographic photoreceptor 1 shown in FIG. 13 has a structure in which an undercoat layer 4, a charge generation layer 5 and a charge transport layer 6 are sequentially laminated on a conductive support 2. The electrophotographic photosensitive member 1 may not have the undercoat layer 4.

  In the electrophotographic photoreceptor 1, the outermost layer disposed on the side farthest from the conductive support 2, that is, the charge transport layer 6 in the photoreceptor 1 shown in FIG. At least one selected from the group consisting of resins and polyolefin resins is contained.

  Hereinafter, the second electrophotographic photosensitive member according to the present invention will be described in detail with reference to FIG.

  First, the conductive support 2 will be described. The material of the conductive support 2 is not particularly limited as long as it has conductivity. For example, metals such as aluminum, nickel, chromium, and stainless steel; aluminum, titanium, nickel, chromium, stainless steel, gold, Examples thereof include a plastic film provided with a thin film such as vanadium, tin oxide, indium oxide, ITO (indium tin oxide); paper or plastic film coated or impregnated with a conductivity-imparting agent, and the like. Although the shape of these conductive supports is not particularly limited, for example, they are used in a drum shape, a sheet shape, a plate shape, or the like.

  Further, when a metal pipe is used as the conductive support 2, the metal pipe may be used as it is, but in advance, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, coloring treatment, etc. It is preferable to use those subjected to the treatment. By roughening the surface of the substrate by the surface treatment, it is possible to prevent grain-like density spots due to interference light in the photosensitive body that may occur when a coherent light source such as a laser beam is used.

  Next, the undercoat layer 4 will be described. The undercoat layer 4 prevents the injection of charges from the conductive support 2 to the photosensitive layer 3 when the photosensitive layer 3 having a laminated structure is charged, and the photosensitive layer 3 is attached to the conductive support 2. It has an action as an adhesive layer that can be integrally bonded and held. Moreover, the undercoat layer 4 can show the antireflection effect of the light of the electroconductive support body 2, etc. depending on the case. From the viewpoint of having such an effect and maintaining a high-quality image, the electrophotographic photoreceptor 1 according to the present invention preferably includes the undercoat layer 4.

  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 and other high molecular resin compounds, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds , Organic titanium compounds, silane coupling agents and the like. In addition, a charge transporting resin having a charge transporting group, a conductive resin such as polyaniline, or the like can be used. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  Of these, resins insoluble in the solvent contained in the coating solution for forming the upper layer (for example, the charge generation layer 5) are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins and the like are particularly preferably used. Furthermore, zirconium chelate compounds and silane coupling agents are excellent in performance, such as low residual potential, little potential change due to environment, and little potential change due to repeated use.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, 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.

  Particularly preferably used silane coupling agents include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane and the like can be mentioned.

  Examples of the zirconium chelate compound 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 the titanium chelate compound 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 contain a conductive substance for improving the photoreceptor characteristics. Examples of the conductive material include metal oxides such as titanium oxide, zinc oxide, and tin oxide, and any known material can be used as long as desired photoreceptor characteristics can be obtained.

  These metal oxides can be surface treated. By performing the surface treatment, resistance value control, dispersibility control, and improvement in photoreceptor characteristics can be achieved. As the surface treatment agent, known materials such as a zirconium chelate compound, a titanium chelate compound, an aluminum chelate compound, a titanium alkoxide compound, an organic titanium compound, and a silane coupling agent can be used. These compounds can be used alone or as a mixture or a polycondensate of a plurality of compounds. Among them, the silane coupling agent is excellent in performance such as low residual potential, little potential change due to environment, little potential change due to repeated use, and excellent image quality characteristics.

  Examples of the silane coupling agent, zirconium chelate compound, titanium chelate compound, and aluminum chelate compound include the same substances as those described above.

  As the surface treatment method, any known method can be used, but 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 or the like, the silane coupling agent is dissolved directly or dissolved in an organic solvent, and the mixture is added to dry air or nitrogen gas. By spraying together, uniform surface treatment is performed. The dropping of the silane coupling agent and the spraying of the mixture are preferably performed at a temperature not higher than the boiling point of the solvent used. When dripping or spraying is performed at a temperature equal to or higher than the boiling point of the solvent, the solvent evaporates before being uniformly stirred, and the silane coupling agent tends to aggregate locally, making uniform treatment difficult.

  The surface-treated metal oxide particles can be further baked at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  As a wet method, metal oxide fine particles are stirred in a solvent, dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with a silane coupling agent solution, stirred or dispersed, and then the solvent is removed. It is processed uniformly by doing. The solvent is preferably distilled off by distillation. In the removal method by filtration, unreacted silane coupling agent tends to flow out, and the amount of silane coupling agent for obtaining desired characteristics tends to be difficult to control. 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. In the wet method, in order to remove moisture contained in the metal oxide fine particles, a method of removing with stirring and heating in a solvent used for surface treatment, a method of removing by azeotropy with a solvent, or the like can be applied. .

  The amount of the silane coupling agent relative to the metal oxide fine particles in the undercoat layer 4 can be any amount as long as desired electrophotographic characteristics can be obtained. Further, the ratio of the metal oxide fine particles and the resin used in the undercoat layer 4 can be arbitrarily set as long as desired electrophotographic characteristics can be obtained.

  Various organic or inorganic fine powders can be mixed in the undercoat layer 4 for the purpose of improving light scattering properties. Preferred examples of such fine powder include white pigments such as titanium oxide, zinc oxide, zinc sulfide, lead white, and lithopone, inorganic pigments as extender pigments such as alumina, calcium carbonate, and barium sulfate, and polytetrafluoroethylene resin. Examples thereof include particles, benzoguanamine resin particles, and styrene resin particles. The particle size of these fine powders is preferably 0.01 to 2 μm. The fine powder is a component that is added as necessary, but the amount added is preferably 10 to 80% by mass with respect to the solid content contained in the undercoat layer 4, It is more preferable that it is 30-70 mass%.

  In the undercoat layer forming coating solution used for forming the undercoat layer 4, various additives can be used for improving electrical characteristics, improving environmental stability, and improving image quality. Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compound, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra- Examples thereof include electron transporting substances such as diphenoquinone compounds such as t-butyldiphenoquinone, electron transporting pigments such as polycyclic condensation systems and azo systems.

  When preparing the coating liquid for forming the undercoat layer, when mixing fine powders such as the above-mentioned conductive substances and light scattering substances, the fine powder is added to the solution in which the resin component is dissolved and the dispersion treatment is performed. It is preferable. As a method for dispersing the fine powder in the resin, methods such as a roll mill, a ball mill, a vibration 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 film thickness of the undercoat layer 4 is preferably 0.01 to 50 μm, more preferably 0.05 to 30 μm.

  Next, the charge generation layer 2 will be described. The charge generation layer 5 includes a charge generation material and a binder resin.

  As such a charge generation material, known charge generation materials can be used without particular limitation, and among them, metal and metal-free phthalocyanine pigments are preferably used, and hydroxygallium phthalocyanine, chlorogallium phthalocyanine, dichlorotin having specific crystals. Phthalocyanine and titanyl phthalocyanine are particularly preferably used.

  The charge generation material preferably used in the charge generation layer 5 is a pigment crystal produced by a known method, mechanically using an automatic mortar, planetary mill, vibration mill, CF mill, roller mill, sand mill, kneader, or the like. It can be manufactured by dry pulverization or by performing wet pulverization using a ball mill, a mortar, a sand mill, a kneader or the like together with a solvent after dry pulverization.

  Solvents used in wet pulverization are aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyvalents Alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide, ether (Diethyl ether, tetrahydrofuran, etc.), a mixed system of these several kinds, or a mixed system of water and these organic solvents.

  The amount of these solvents to be used is preferably 1 to 200 parts by mass, more preferably 10 to 100 parts by mass with respect to 1 part by mass of the pigment crystal. The treatment temperature in the wet pulverization treatment is preferably 0 ° C. or higher and the boiling point of the solvent or lower, more preferably 10 to 60 ° C. In addition, grinding aids such as salt and sodium nitrate may be used during grinding. The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times (all in terms of mass) with respect to the pigment.

  Moreover, about the pigment crystal manufactured by a well-known method, crystal control can also be carried out by the combination of acid pasting or acid pasting and the above-mentioned dry grinding or wet grinding. The acid used for acid pasting is preferably sulfuric acid. The concentration of this sulfuric acid is preferably 70 to 100%, more preferably 95 to 100%. The amount of concentrated sulfuric acid is preferably set in the range of 1 to 100 times, more preferably 3 to 50 times (both in terms of mass) with respect to the mass of the pigment crystals. The dissolution temperature is preferably -20 to 100 ° C, more preferably 0 to 60 ° C. As a solvent for precipitating crystals from an acid, water or a mixed solvent of water and an organic solvent can be used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation.

  These charge generation materials 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 generating material and the coating property of the coating solution for forming the charge generating layer, and the charge generating layer 5 having a smooth and highly uniform dispersion can be easily and reliably formed. As a result, image quality defects such as fogging and ghosting can be prevented, and image quality maintenance can be improved. Further, since the storage stability of the charge generation layer forming coating solution is remarkably improved, it is effective in extending the pot life, and the cost of the photoreceptor can be reduced.

The organometallic compound having a hydrolyzable group is a compound represented by the following general formula (IV).
_{R p -M-Y q (IV} )
Here, in the above 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, The sum of p and q corresponds to the valence of M.

  In general formula (IV), 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, tolyl group, naphthyl group, arylalkyl group such as benzyl group, phenylethyl group, arylalkenyl group such as styryl group, furyl group, thienyl group, pyrrolidinyl group, pyridyl group, imidazolyl And heterocyclic residues such as groups. These organic groups may have one or two or more kinds of substituents.

  In the general formula (IV), examples of the hydrolyzable group represented by Y include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a cyclohexyloxy group, a phenoxy group, a benzyloxy group, an 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.

  Moreover, in general formula (IV), although M will not be restrict | limited especially if it is other than an alkali metal, Preferably they are a titanium atom, an aluminum atom, a zirconium atom, or a silicon atom. That is, in the photoreceptor according to 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 the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycine. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- ( Aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxy) Ethoxysilane), 3 Methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N -2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxy Examples include silane.

  Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 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 (IV). The hydrolyzable group to be substituted is hydrolyzed. In addition, 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 for coating a phthalocyanine pigment using the above-mentioned organometallic compound having a hydrolyzable group and / or a silane coupling agent (hereinafter simply referred to as “organometallic compound”), A method of coating the phthalocyanine pigment, a method of coating before dispersing the phthalocyanine pigment in the binder resin, a method of mixing an organometallic compound when dispersing the phthalocyanine pigment into the binder resin, and a binder resin of the phthalocyanine pigment For example, a method of further dispersing with an organometallic compound after dispersion in the solution.

  More specifically, as a method of coating in advance in the process of preparing the pigment crystals, a method of heating after mixing the organometallic compound and the phthalocyanine pigment before the crystals are arranged, and before the crystals of the organometallic compound are arranged Examples thereof include a method of mixing with a phthalocyanine pigment and mechanically dry pulverizing, a mixture of an organic metal compound in water or an organic solvent with a phthalocyanine pigment before crystals are prepared, and a wet pulverizing method.

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

  Further, as a method of mixing treatment at the time of dispersion, there are a method of mixing while sequentially adding an organometallic compound, a phthalocyanine pigment and a binder resin to a dispersion solvent, a method of simultaneously adding and mixing these charge generation layer 5 forming components, and the like. Can be mentioned.

  Further, as a method of further dispersing with an organometallic compound after dispersing the phthalocyanine pigment in the binder resin, for example, a method of adding an organometallic compound diluted with a solvent to the dispersion and dispersing with stirring. 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 the phthalocyanine pigment.

  Among these, a method of coating in advance in the process of preparing the crystals of the phthalocyanine pigment, or a method of coating before dispersing the phthalocyanine pigment 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. It can also be selected from organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene and polysilane. Preferred binder resins include polyvinyl butyral resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Examples thereof include, but are not limited to, resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins and the like. These binder resins can be used alone or in admixture of two or more. The blending ratio (mass ratio) between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10.

  The charge generation layer 5 is formed, for example, by applying a charge generation layer forming coating solution containing a charge generation material and a binder resin. As a solvent of the coating solution, any solvent can be used without particular limitation as long as the binder resin can be dissolved. For example, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl Usable organic solvents such as cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene and toluene can be used alone or in admixture of two or more. .

  As a method for dispersing the charge generation material and the binder resin in a solvent, a usual method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. It is preferable to carry out the conditions under which the mold does not change. In this dispersion, it is effective that the charge generating material has a particle size of preferably 0.5 μm or less, more preferably 0.3 μm or less, and still more preferably 0.15 μm or less.

  Examples of the application method of the application liquid include ordinary 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, and a curtain coating method.

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

  Next, the charge transport layer 6 will be described. The charge transport layer 6 includes a charge transport material and a binder resin. As described above, the charge transport layer 6 includes at least one selected from the group consisting of a fluorine resin, a silicone resin, and a polyolefin resin, and most preferably includes a fluorine resin.

  Examples of such fluororesins include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluoropropylene resin, hexafluoroethylenepropylene resin, vinyl fluoride resin, vinylidene fluoride resin, and difluorodiethylene chloride resin. In addition, it is preferable to use at least one selected from the group consisting of copolymers comprising two or more monomers constituting these resins. The fluororesin usually has a particle shape, but the average primary particle size is preferably 0.05 to 1 μm, more preferably 0.1 to 0.5 μm. If the average primary particle size is less than 0.05 μm, aggregation during dispersion tends to occur, and if it exceeds 1 μm, image quality defects in the formed image tend to occur.

  Furthermore, the content of the fluororesin in the charge transport layer 6 is preferably 0.1 to 40% by mass, and preferably 1 to 30% by mass based on the total amount of solids contained in the charge transport layer 6. Is more preferable. If the content is less than 1% by mass, the modification effect by the fluorine-based resin tends to be inadequate, and the life of the photoreceptor tends to be insufficient. If the content exceeds 40% by mass, the light transmission property is reduced or repeated. There is a tendency that the residual potential increases due to use.

  As the polyolefin resin, it is preferable to use an amorphous aliphatic polyolefin represented by ZEONEX resin manufactured by Nippon Zeon Co., Ltd.

  Examples of the charge transport material used for the charge transport layer 6 include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, and 1,3,5-triphenyl. -Pyrazoline, pyrazoline derivatives such as 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (p-methylphenyl) aminyl-4 -Aromatic tertiary amino compounds such as amine and dibenzylaniline, aromatic tertiary diamino compounds such as N, N'-bis (3-methylphenyl) -N, N'-diphenylbenzidine, 3- (4 1,2,4-triazine derivatives such as' -dimethylaminophenyl) -5,6-di- (4'-methoxyphenyl) -1,2,4-triazine, A hydrazone derivative such as diethylaminobenzaldehyde-1,1-diphenylhydrazone, a quinazoline derivative such as 2-phenyl-4-styryl-quinazoline, a benzofuran derivative such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, Hole transport such as α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof Substances: quinone compounds such as chloranil and broanthraquinone, tetraanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, xanthone Compounds, thiophene compounds, etc. Examples thereof include an electron transport material; or a polymer having a residue obtained by removing a hydrogen atom or the like from the above compound in the main chain or side chain. These charge transport materials can be used singly or in combination of two or more.

  Examples of the binder resin used for the charge transport layer 6 include acrylic resin, polyarylate, polyester resin, polycarbonate resin such as bisphenol A type or bisphenol Z type, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer. Insulating resins such as polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, and chlorine rubber, and organic photoconductive polymers such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene. These binder resins can be used singly or in combination of two or more.

  When the charge transport layer 6 is formed, first, the charge transport material and the binder resin are dissolved and / or dispersed in a predetermined solvent, and then the above-described fluorine resin, silicone resin, and polyolefin resin are used. A coating liquid for forming a charge transport layer is prepared by adding and dispersing at least one selected from the group described above. Next, the charge transport layer 6 can be formed by applying the coating liquid onto the charge generation layer 5 and drying it.

  Examples of the solvent used in the charge transport layer forming coating solution include aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol, and n-butanol, acetone, cyclohexanone, and 2-butanone. Ketone solvents, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform, and ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol, and diethyl ether, or a mixed solvent thereof. be able to. The blending ratio (mass ratio) between the charge transport material and the binder resin is preferably 10: 1 to 1: 5.

  As a method of dispersing the fluororesin when preparing the coating solution, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a high-pressure homogenizer, an ultrasonic disperser, a colloid mill, a collision-type medialess disperser, and a penetrating medium A method such as a loess disperser can be used.

  Further, when preparing the coating liquid, it is preferable to further add a dispersion aid from the viewpoint of improving the dispersion stability of the fluororesin and preventing aggregation during the formation of the coating film. Examples of such dispersion aids include fluorine-based surfactants, fluorine-based polymers, silicone-based polymers, and silicone oils.

  Examples of a method for applying such a coating solution include a dip coating method, a push-up coating method, a spray coating method, a roll coater coating method, and a gravure coater coating method. The film thickness of the charge transport layer 6 is preferably 5 to 50 μm, and more preferably 10 to 35 μm.

  In the electrophotographic photoreceptor according to the present invention, the photosensitive layer 3 may have a single layer structure containing the charge transport material and the charge generation material in the same layer. In this case, the photosensitive resin 3 may contain the specific resin, and the specific resin content, dispersion method, and the like at this time are the same as those in the charge transport layer 6 described above. It is preferable to adopt the following conditions.

In the second electrophotographic photosensitive member according to the present invention, for the purpose of preventing deterioration of the photosensitive member due to ozone or NO _x generated in the image forming apparatus 100 or light or heat, an antioxidant, Additives such as light stabilizers and heat stabilizers can be added.

  Examples of the antioxidant include hindered phenols, hindered amines, paraphenylenediamines, arylalkanes, hydroquinones, spirochromans, spiroidanones and their derivatives, organic sulfur compounds, and organic phosphorus compounds.

  Examples of the light stabilizer include derivatives such as benzophenone, benzoazole, dithiocarbamate, and tetramethylpipen.

  For the purpose of improving the smoothness of the surface of the electrophotographic photosensitive member, a leveling agent such as silicone oil can be added to the outermost layer of the electrophotographic photosensitive member.

  In the second image forming apparatus equipped with the second electrophotographic photosensitive member described above, the linear velocity of the photosensitive member surface is preferably 100 mm / second or more, and the image resolution with respect to the traveling direction of the photosensitive member surface is 1200 dots / second. It is preferably at least inches. In the second image forming apparatus, image formation can be performed under the specific conditions, and higher resolution image quality can be obtained.

  The first and second image forming apparatuses of the present invention may be a monochrome image forming apparatus or a tandem color image forming apparatus in addition to the one shown in FIG. Next, a tandem color image forming apparatus will be described. The “tandem image forming apparatus” refers to an image forming apparatus having two or more of the following image forming units. The first electrophotographic photosensitive member is mounted on the first image forming apparatus, and the second electrophotographic photosensitive member is mounted on the second image forming apparatus.

  FIG. 10 is a schematic configuration diagram showing another preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 200 shown in FIG. 10 is a tandem image forming apparatus having two or more image forming units each including at least a charging device 402a to 402d, an exposure device 403, and a developing device 404a to 404d. Note that the charging devices 402a to 402d are contact charging type charging devices, and the transfer device has a configuration employing an intermediate transfer method.

  More specifically, the tandem image forming apparatus 200 includes four electrophotographic photosensitive members 401a to 401d (for example, the electrophotographic photosensitive member 401a is yellow, the electrophotographic photosensitive member 401b is magenta, and the electrophotographic photosensitive member in the housing 400. The body 401c can form an image of cyan and the electrophotographic photoreceptor 401d can form an image of black, respectively.) Are arranged in parallel along the intermediate transfer belt 409. The image forming apparatus 200 further includes cleaning units 415a to 415d.

  Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 200 are the first electrophotographic photoreceptor or the second electrophotographic photoreceptor described above, respectively.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and charging rolls 402a to 402d (contact charging devices that charge the electrophotographic photosensitive member) along the rotation direction. , Developing devices 404a to 404d (developing devices that develop toner images by developing electrostatic latent images formed by an exposure device), primary transfer rolls 410a to 410d {the toner images formed by the developing device are described later. The intermediate transfer belt 409 (transfer device for primary transfer to the intermediate transfer member)} and cleaning blades 415a to 415d (cleaning means) are disposed. Each of the developing devices 404a to 404d can be supplied with toners of four colors, black, yellow, magenta, and cyan accommodated in a toner cartridge, and the primary transfer rolls 410a to 410d are respectively connected to the intermediate transfer belt 409 (1 The intermediate transfer member that transfers the next transfer image to the transfer medium 500 is in contact with the electrophotographic photosensitive members 401a to 401d.

  Further, an exposure device 403 (exposure device for exposing an electrophotographic photosensitive member charged by a charging device to form an electrostatic latent image) serving as a laser light source is disposed at a predetermined position in the housing 400, and a laser. Laser light emitted from the light source 403 can be applied to the surfaces of the charged electrophotographic photosensitive members 401a to 401d. The exposure apparatus 403 includes the above-described SLED as an exposure light source.

  Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

  The charging devices (charging members) 402a to 402d are provided with roller-shaped contact charging members, and are arranged so as to be in contact with the surfaces of the photoconductors 401a to 401d. The body surface is charged to a predetermined potential. The charging device includes metals such as aluminum, iron and copper, conductive polymer materials such as polyacetylene, polypyrrole and polythiophene, polyurethane rubber, silicone rubber, epichlorohydrin rubber, ethylene propylene rubber, acrylic rubber, fluorine rubber, styrene-butadiene rubber A material obtained by dispersing metal oxide particles such as carbon black, copper iodide, silver iodide, zinc sulfide, silicon carbide, and metal oxide in an elastomer material such as butadiene rubber can be used.

Examples of the metal oxide include ZnO, SnO ₂ , TiO ₂ , In ₂ O ₃ , MoO _{3, and the} like, or a composite oxide thereof. Further, the charging devices 402a to 402d may be made by adding perchlorate in an elastomer material and imparting conductivity.

  Further, the charging devices 402a to 402d may be provided with a coating layer on the surface thereof. As a material for forming the coating layer, N-alkoxymethylated nylon, cellulose resin, vinyl pyridine resin, phenol resin, polyurethane, polyvinyl butyral, melamine and the like are used alone or in combination. Also, emulsion resin-based materials such as acrylic resin emulsion, polyester resin emulsion, polyurethane, especially emulsion resin synthesized by soap-free emulsion polymerization can be used.

  In these resins, in order to further adjust the resistivity, conductive agent particles may be dispersed, or an antioxidant may be contained in order to prevent deterioration. Moreover, in order to improve the film formability when forming the coating layer, the emulsion resin may contain a leveling agent or a surfactant. Examples of the shape of the contact charging member include a roller shape, a blade shape, a belt shape, and a brush shape.

Furthermore, the electric resistance values of the charging devices 402a to 402d are preferably 10 ² to 10 ¹⁴ Ωcm, and more preferably 10 ² to 10 ¹² Ωcm. Further, as the voltage applied to the contact charging member, either direct current or alternating current can be used. It can also be applied in the form of DC + AC (a DC voltage and an AC voltage superimposed).

  Examples of the transfer devices 410a to 410d include a contact transfer charger using a belt, a roller, a film, a rubber blade, and the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like.

  Further, as the developing devices 404a to 404d, a conventionally known developing device using a regular or reversal developer such as a one-component system or a two-component system can be used. Among these developers, it is preferable to use a two-component development method using a two-component developer for the reason of improving the image quality. In this case, the developer used for visualizing the electrostatic latent image is composed of toner and carrier. Further, the shape of the toner to be used is not particularly limited, and for example, an irregular toner by a pulverization method or a spherical toner by a polymerization method is preferably used.

  The cleaning means 415a to 415d are for removing residual toner adhering to the surface of the electrophotographic photoreceptors 401a to 401d after the transfer process, and thus cleaned electrophotographic photoreceptors 401a to 401d. Is repeatedly applied to the image forming process described above. As the cleaning means 415a to 415d, a cleaning blade, brush cleaning, roll cleaning, or the like can be used. Among these, it is preferable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  The intermediate transfer belt 409 can be manufactured by the following procedure. That is, a polyamic acid solution is obtained by polymerizing a substantially equimolar amount of tetracarboxylic dianhydride or derivative thereof and diamine in a predetermined solvent. After this polyamic acid solution is supplied to a cylindrical mold and developed to form a film (layer), imide conversion is further performed, whereby an intermediate transfer belt 409 made of polyimide resin can be obtained.

  Examples of such tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. Anhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9,10-tetra Examples thereof include carboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like.

Specific examples of the diamine include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,3′-dichlorobenzidine, 4,4′-diaminodiphenyl sulfide, 3,3′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3′-dimethyl-4,4′-biphenyldiamine, benzidine, 3,3′-dimethylbenzidine 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylpropane, 2,4-bis (β-aminotert-butyl) toluene, bis (p-β-amino- Tert-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis p- (1,1-dimethyl-5-amino-benzyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane , Hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1 , 2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2, 17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, _{piperazine, H 2 N (CH 2)} 3 O (CH 2) 2 O (CH 2) NH 2, H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N _{(CH 3) 2 (CH 2} ) 3 NH 2 and the like.

  The solvent for the polymerization reaction of tetracarboxylic dianhydride and diamine is preferably a polar solvent from the viewpoint of solubility. As the polar solvent, N, N-dialkylamides are preferable. Among them, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, N, N-dimethylmethoxy are preferred. Low molecular weight compounds such as acetamide, dimethyl sulfoxide, hexamethyl phosphortriamide, N-methyl-2-pyrrolidone, pyridine, tetramethylene sulfone, and dimethyltetramethylene sulfone are more preferable. These may be used alone or in combination of two or more.

  In order to adjust the film resistance of the intermediate transfer belt 409, carbon may be dispersed in the polyimide resin. The type of carbon is not particularly limited, but it is preferable to use oxidized carbon black in which an oxygen-containing functional group (carboxyl group, quinone group, lactone group, hydroxyl group, etc.) is formed on the surface of the carbon black by oxidation treatment. If the oxidized carbon black is dispersed in the polyimide resin, an excessive current flows through the oxidized carbon black when a voltage is applied, so that the polyimide resin is less susceptible to oxidation due to repeated voltage application. In addition, since the oxidized carbon black has high dispersibility in the polyimide resin due to the oxygen-containing functional groups formed on the surface thereof, resistance variation can be reduced and electric field dependency is reduced, and electric field concentration due to transfer voltage is reduced. Is less likely to occur. Therefore, resistance drop due to transfer voltage is prevented, uniformity of electrical resistance is improved, electric field dependency is small, resistance change due to environment is small, and occurrence of image quality defects such as white running out of paper running part is suppressed. Thus, an intermediate transfer belt capable of obtaining the high image quality can be obtained.

  Oxidized carbon black is an air oxidation method in which carbon black is contacted and reacted with air in a high temperature atmosphere, a method in which it reacts with nitrogen oxides or ozone at room temperature, air oxidation at high temperature, and ozone oxidation at low temperature. It can obtain by the method of doing.

  Further, as oxidation-treated carbon, MA100 (pH 3.5, volatile matter 1.5%), MA100R (pH3.5, volatile matter 1.5%), MA100S (pH3.5, volatile matter) manufactured by Mitsubishi Chemical Co., Ltd. 1.5%), # 970 (pH 3.5, volatile content 3.0%), MA11 (pH 3.5, volatile content 2.0%), # 1000 (pH 3.5, volatile content 3.). 0%), # 2200 (pH 3.5, volatile content 3.5%), MA 230 (pH 3.0, volatile content 1.5%), MA 220 (pH 3.0, volatile content 1.0%), # 2650 (pH 3.0, volatile content 8.0%), MA7 (pH 3.0, volatile content 3.0%), MA8 (pH 3.0, volatile content 3.0%), OIL7B (pH 3) 0.0, volatile matter 6.0%), MA77 (pH 2.5, volatile matter 3.0%), # 2350 (p 2.5, volatile content 7.5%), # 2700 (pH 2.5, volatile content 10.0%), # 2400 (pH 2.5, volatile content 9.0%); Printex made by Degussa 150T (pH 4.5, volatile content 10.0%), Special Black 350 (pH 3.5, volatile content 2.2%), Special Black 100 (pH 3.3, volatile content 2.2%), Special Black 250 (pH 3.1, volatile content 2.0%), Special Black 5 (pH 3.0, volatile content 15.0%), Special Black 4 (pH 3.0, volatile content 14.0%), Special Black 4A (pH 3.0, volatile content 14.0%), Special Black 550 (pH 2.8, volatile content 2.5%), Special Black 6 (pH 2.5, volatile content 18.0%), Same color black FW2 0 (pH 2.5, volatile content 20.0%), same color black FW2 (pH 2.5, volatile content 16.5%), same color black FW2V (pH 2.5, volatile content 16.5%); Cabot Corporation MONARCH1000 (pH 2.5, volatile content 9.5%), MONARCH 1300 (pH 2.5, volatile content 9.5%), MONARCH 1400 (pH 2.5, volatile content 9.0%), MOGUL-L ( Commercial products such as pH 2.5, volatile matter 5.0%) and REGAL400R (pH 4.0, volatile matter 3.5%) may be used. Such oxidized carbon is preferably one having a pH of 4.5 or less and a volatile content of 1.0% or more.

  The above-mentioned oxidized carbon, for example, has different conductivity depending on physical properties such as the degree of oxidation treatment, DBP oil absorption, specific surface area by BET method using nitrogen adsorption, etc., but these may be used alone. Two or more types may be used in combination, but it is preferable to use two or more types having substantially different conductivity. When two or more types of carbon blacks having different physical properties are added as described above, for example, carbon black exhibiting high conductivity is preferentially added, and then carbon black having low conductivity is added to adjust the surface resistivity. It is possible.

  The content of the oxidized carbon black is preferably 10 to 50% by mass, more preferably 12 to 30% by mass with respect to the polyimide resin. When the content is less than 10% by mass, the uniformity of electrical resistance is lowered, and the surface resistivity during durability use may be greatly reduced. On the other hand, when the content exceeds 50% by mass, a desired resistance value is obtained. Is not obtained, and it is not preferable because it becomes brittle as a molded product.

  As a method for producing a polyamic acid solution in which two or more types of oxidized carbon black are dispersed, the acid dianhydride component and the diamine component are added to a dispersion in which two or more types of oxidized carbon black are previously dispersed in a solvent. Dissolution / polymerization method Two or more types of oxidized carbon black were dispersed in a solvent to prepare two or more types of carbon black dispersions, and acid anhydride components and diamine components were dissolved and polymerized in the dispersions. Thereafter, a method of mixing the respective polyamic acid solutions is exemplified.

  The intermediate transfer belt 409 is obtained by supplying and developing the polyamic acid solution thus obtained on the inner surface of the cylindrical mold to form a coating film, and converting the polyamic acid to imide by heating. In such imide conversion, an intermediate transfer belt having good flatness can be obtained by holding at a predetermined temperature for 0.5 hour or more.

  Examples of a supply method for supplying the polyamic acid solution to the inner surface of the cylindrical mold include a method using a dispenser and a method using a die. Here, it is preferable to use a cylindrical mold having a mirror-finished inner peripheral surface.

  Examples of the method of forming a film from the polyamic acid solution supplied to the mold include a method of centrifugal molding while heating, a method of molding using a bullet-shaped traveling body, a method of rotational molding, and the like. A film having a uniform film thickness is formed by the method.

  The method for forming the intermediate transfer belt by converting the film thus formed into an imide is (i) a method in which the mold is placed in a dryer and the temperature is raised to a reaction temperature for imide conversion, and (ii) a belt. As the method, after removing the solvent until the shape can be maintained, the film is peeled off from the inner surface of the mold and replaced with the outer surface of the metal cylinder, and then the entire cylinder is heated to perform imide conversion. In the present invention, imide conversion may be performed by any of the above methods (i) and (ii) as long as the dynamic hardness of the surface of the obtained intermediate transfer belt satisfies the above conditions. Conversion is preferable because an intermediate transfer member having good flatness and outer surface accuracy can be obtained efficiently and reliably. Hereinafter, the method (ii) will be described in detail.

  In method (ii), the heating conditions for removing the solvent are not particularly limited as long as the solvent can be removed, but the heating temperature is preferably 80 to 200 ° C., and the heating time is 0.5 to 5 hours. Is preferred. In this way, the molded product that can retain its shape as a belt is peeled off from the inner peripheral surface of the mold. Also good.

  Next, the molded product heated and cured until it can be held in a belt shape is replaced with the outer surface of the metal cylinder, and the replaced cylinder is heated to advance the imide conversion reaction of the polyamic acid. As such a metal cylinder, one having a linear expansion coefficient larger than that of polyimide resin is preferable, and by setting the outer diameter of the cylinder to be a predetermined amount smaller than the inner diameter of the polyimide molding, a uniform film can be formed. An endless belt having a uniform thickness can be obtained. Moreover, it is preferable that the surface roughness (Ra) of a metal cylinder outer surface is 1.2-2.0 micrometers. When the surface roughness (Ra) of the outer surface of the metal cylinder is less than 1.2 μm, the metal cylinder itself is too smooth, and the resulting intermediate transfer belt does not slip due to contraction in the axial direction of the belt. This process is performed, and the film thickness variation and the flatness accuracy tend to decrease. If the surface roughness (Ra) of the outer surface of the metal cylinder exceeds 2.0 μm, the outer surface of the metal cylinder is transferred to the inner surface of the belt-shaped intermediate transfer body, and further, irregularities are generated on the outer surface. Tends to occur. In addition, the surface roughness as used in this embodiment means Ra measured according to JISB601.

  Moreover, although it is based also on a composition of a polyimide resin as heating conditions in the case of imide conversion, it is preferable that heating temperature is 220-280 degreeC and heating time 0.5-2 hours. When imide conversion is performed under such heating conditions, the amount of shrinkage of the polyimide resin becomes larger, and therefore, the shrinkage in the axial direction of the belt is gently performed to prevent a decrease in film thickness variation and flatness accuracy. Can do.

  The surface roughness (Ra) of the outer surface of the intermediate transfer belt made of the polyimide resin thus obtained is preferably 1.5 μm or less. If the surface roughness (Ra) of the intermediate transfer member exceeds 1.5 μm, image defects such as roughness tend to occur. Note that the occurrence of roughness is caused by the development of a new conductive path due to the voltage applied during transfer and the electric field due to peeling discharge locally concentrated on the convex portion of the belt surface and the convex portion surface being altered. The present inventors infer that the resistance is lowered and the density of the resulting image is lowered.

  The intermediate transfer belt 409 thus obtained is preferably a seamless belt. In the case of this seamless belt, the film thickness of the intermediate transfer belt 409 can be appropriately determined according to the purpose of use, but is preferably 20 to 500 μm, more preferably 50 to 200 μm from the viewpoint of mechanical properties such as strength and flexibility. preferable. Further, the surface resistance of the intermediate transfer belt 409 is preferably 8 to 15 (log Ω / □) as a common logarithm of the surface resistivity (Ω / □), and preferably 11 to 13 (log Ω / □). Is more preferable. Here, the surface resistivity refers to a value obtained based on a current value measured 10 seconds after the voltage application start when a voltage of 100 V is applied in an environment of 22 ° C. and 55% RH. Here, “surface resistance [Ω / □]” means “Thin Film Handbook” (published by Ohmsha) p. It is synonymous with “surface resistance” described in 896, and shows a resistance expressed between two opposing sides by cutting a planar resistor into a square. This surface resistance is independent of the dimensions of the square if the resistance distribution is uniform.

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

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

  As described above, in the rotation process of the electrophotographic photoreceptors 401a to 401d, image formation is repeatedly performed by sequentially performing the charging, exposure, development, transfer, and cleaning processes. Here, the electrophotographic photoconductors 401a to 401d are the electrophotographic photoconductor 1 described above, and both the anti-leakage property and the electrical characteristics are achieved at a sufficiently high level. Even when used together with 402d, it is possible to obtain good image quality without causing image quality defects such as fogging. Therefore, according to the present embodiment, even when used repeatedly over a long period of time, an image forming apparatus 200 that can sufficiently prevent occurrence of pinhole leak in the photoreceptor and can form a color image with excellent image quality at high speed is realized. Is done.

  The present invention is not limited to the above embodiment. For example, the apparatus shown in FIG. 14 may include a process cartridge including electrophotographic photosensitive members 401a to 401d and contact charging devices 402a to 402d. By using such a process cartridge, maintenance can be performed more easily.

  The image forming apparatus of the present invention may further include a static eliminator such as an erase light irradiation device. As a result, when the electrophotographic photosensitive member is repeatedly used, the phenomenon that the residual potential of the electrophotographic photosensitive member is brought into the next cycle is prevented, so that the image quality can be further improved.

  Next, the first and second process cartridges of this embodiment will be described. The first and second process cartridges include an electrophotographic photosensitive member, a charging device that charges the electrophotographic photosensitive member, an exposure device that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, and an electrophotographic photosensitive member. And at least one selected from cleaning devices for cleaning the body.

  FIG. 15 is a schematic configuration diagram showing a preferred embodiment of a process cartridge. The process cartridge 300 includes an electrophotographic photosensitive member 307, a charging device 308, a developing device 311, an intermediate transfer member 320 (intermediate transfer device), a cleaning device 313, an opening 318 for exposure, and an opening for static elimination exposure. The part 317 is combined and integrated using the mounting rail 316. Further, the process cartridge 300 has a configuration in which the transfer method of the transfer device 312 employs an intermediate transfer method in which a toner image is transferred to the transfer medium 500 via the intermediate transfer member 320. The electrophotographic photoreceptor 307 is the first electrophotographic photoreceptor or the second electrophotographic photoreceptor described above. The above-described first electrophotographic photosensitive member is mounted on the first process cartridge, and the above-described second electrophotographic photosensitive member is mounted on the second process cartridge.

  The process cartridge 300 is detachably attached to an image forming apparatus main body including a transfer device 312, a fixing device 315, and other components not shown, and the image forming apparatus together with the image forming apparatus main body. It constitutes.

  In the process cartridge of this embodiment, the charging device 308 (charging member) can employ a contact charging method using a charging roll, a charging brush, a charging film, a charging tube, or the like. 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 supporting them, and a core material from the outside. Furthermore, a protective layer can be provided outside the resistance layer as necessary.

  The developing device 311 used in the process cartridge of the present embodiment described above will be specifically described. The developing device 311 can be appropriately selected according to the purpose. For example, a one-component developer or a two-component developer is used. Examples include a known developing device that develops a developer based on contact or non-contact with a brush or roller. The toner is made by a mechanical pulverization method or chemical polymerization. Examples of the shape of the toner include an irregular shape and a spherical shape.

  The intermediate transfer device 320 used in the process cartridge of the present embodiment will be specifically described. As the intermediate transfer device 320, for example, a contact type transfer charger using a belt, a roller, a film, a rubber blade, or the like, Examples thereof include known transfer chargers such as a scorotron transfer charger using a corona discharge and a corotron transfer charger. Among these, a contact type transfer charger is preferable in that it has excellent transfer charge compensation capability. In the present invention, in addition to the transfer charger, a peeling charger can be used in combination.

  The cleaning device 313 used in the process cartridge of this embodiment described above will be specifically described. The cleaning device 313 is not particularly limited, and a known cleaning device or the like may be used. Examples thereof include a urethane blade and a cleaning brush.

  Specifically, the static eliminator (photo static eliminator) used in the process cartridge of the present embodiment described above will be described. Examples of the photo static eliminator include a tungsten lamp, an LED, and the like. Examples of the quality include white light such as a tungsten lamp, red light such as LED light, and the like. The irradiation light intensity in the photostatic process is usually set to output several times to about 30 times the amount of light indicating the half exposure sensitivity of the electrophotographic photosensitive member. In the present embodiment, the light from such a light neutralizing device is taken in through the opening 317 to neutralize the photosensitive member.

  Such a process cartridge of this embodiment is mounted on the image forming apparatus on which the exposure apparatus having the self-scanning LED described above is mounted, and by mounting the electrophotographic photosensitive member. In addition, it is possible to achieve high image quality, high image formation speed, and long life of the photoreceptor. The process cartridge 300 may include an exposure device instead of the opening 318. In that case, the process cartridge 300 includes the above-described SLED as an exposure light source.

  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. In the following examples, “part” means part by mass. In this example, first, an electrophotographic photosensitive member was produced. Then, an image forming apparatus was produced using the electrophotographic photosensitive member, and an evaluation test was performed.

(Preparation of electrophotographic photoreceptor)
In the production of the electrophotographic photoreceptor, first, a base photoreceptor and a coating solution for forming a protective layer were produced, and an electrophotographic photoreceptor was produced using the base photoreceptor and the coating solution for forming a protective layer.

(Base photoconductor 1-1, base photoconductor 1-2)
20 parts of zirconium compound (trade name: Organotix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 2.5 parts of silane compound (trade name: A1100, manufactured by Nihon Unicar Co., Ltd.) on an aluminum substrate having an outer diameter of 30 mm subjected to honing treatment And an undercoat layer forming solution consisting of 45 parts of butanol and a polyvinyl butyral resin (trade name: ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.), and dried by heating at 150 ° C. for 10 minutes to form a membrane. An undercoat layer having a thickness of 1.0 μm was formed.

  Next, 15 parts of hydroxygallium phthalocyanine having diffraction peaks at X-ray diffraction spectra (2θ ± 0.2 °) of 7.3 °, 16.0 °, 24.9 ° and 28.0 °, It is obtained after mixing 10 parts of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin and 300 parts of n-butyl acetate and dispersing with glass beads for 0.5 hour in a horizontal sand mill. The charge generation layer forming coating solution was dip coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

  Next, 2 parts of the compound represented by the following formula (1) and 3 parts of a polymer compound having a structural unit represented by the following formula (2) (viscosity average molecular weight 39,000) are added to 15 parts of tetrahydrofuran and 5 parts of chlorobenzene. A coating solution for forming a charge transport layer was prepared by dissolving in a mixed solvent. This coating solution was applied onto the charge generation layer by a dip coating method and dried in hot air at 135 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. The configuration so far is defined as the base photoconductor 1-1. Further, a base photoconductor 1-2 having the same configuration as that of the base photoconductor 1-1 was prepared except that the thickness of the charge transport layer was changed to 30 μm.

(Base photoconductor 2-1, base photoconductor 2-2, base photoconductor 2-3, base photoconductor 2-4)
20 parts of zirconium compound (trade name: Organotix ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 2.5 parts of silane compound (trade name: A1100, manufactured by Nihon Unicar Co., Ltd.) on an aluminum substrate having an outer diameter of 30 mm subjected to honing treatment And a polyvinyl butyral resin (trade name: ESREC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and a coating solution for forming an undercoat layer comprising 45 parts of butanol by a dip coating method, and dried by heating at 150 ° C. for 10 minutes, An undercoat layer having a thickness of 1.0 μm was formed.

  Next, 15 parts of hydroxygallium phthalocyanine having diffraction peaks at X-ray diffraction spectra (2θ ± 0.2 °) of 7.3 °, 16.0 °, 24.9 ° and 28.0 °. , 10 parts of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin and 300 parts of n-butyl acetate were mixed and dispersed with glass beads for 0.5 hour in a horizontal sand mill. The resulting charge generation layer forming coating solution was dip coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

  Next, 2 parts of a compound represented by the following formula (3) and 3 parts of a polymer compound having a structural unit represented by the above formula (2) (viscosity average molecular weight 39,000) are added to 15 parts of tetrahydrofuran and 5 parts of chlorobenzene. A coating solution for forming a charge transport layer was prepared by dissolving in a mixed solvent. This coating solution was applied onto the charge generation layer by a dip coating method and dried in hot air at 135 ° C. for 40 minutes to form a charge transport layer having a thickness of 17 μm. The configuration so far is referred to as a base photoconductor 2-1. Also, base photoconductors 2-2, 2-3, and 2-4 having the same configuration as the base photoconductor 1-1 were prepared except that the thickness of the charge transport layer was 25 μm, 30 μm, and 35 μm.

(Base photoconductor 3-1)
100 parts of zinc oxide (average particle size 70 nm: prototype manufactured by Teika) was stirred and mixed with 500 parts of toluene, 1.5 parts of a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) was added, and the mixture was stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 2 hours. 60 parts of zinc oxide subjected to the above surface treatment, 15 parts of blocked isocyanate (Sumijour 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) and 15 parts of butyral resin BM-1 (manufactured by Sekisui Chemical Co., Ltd.) as 85 parts of methyl ethyl ketone Dissolved. 38 parts of this solution and 25 parts of methyl ethyl ketone were mixed and dispersed for 2 hours in a sand mill using 1 mmφ glass beads to obtain a dispersion. As a catalyst, 0.005 part of dioctyltin dilaurate was added to the obtained dispersion to obtain a coating liquid for forming an undercoat layer. This coating solution was applied on an aluminum substrate having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 160 ° C. for 100 minutes to form an undercoat layer having a thickness of 20 μm.

  Next, 15 parts of hydroxygallium phthalocyanine having diffraction peaks at X-ray diffraction spectra (2θ ± 0.2 °) of 7.3 °, 16.0 °, 24.9 ° and 28.0 °, 10 parts of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar Co., Ltd.) as a binder resin and 300 parts of n-butyl acetate were mixed and dispersed with glass beads in a horizontal sand mill for 0.5 hour. Thereafter, the resulting coating solution for forming a charge generation layer was dip-coated on the undercoat layer and dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of about 0.15 μm.

  Next, 2 parts of the compound represented by the above formula (1) and 3 parts of a polymer compound having a structural unit represented by the above formula (2) (viscosity average molecular weight 39,000) were added to 15 parts of tetrahydrofuran and 5 parts of chlorobenzene. It was dissolved in a mixed solvent. The obtained coating solution for forming a charge generation layer was applied on the charge generation layer by a dip coating method and dried in hot air at 135 ° C. for 40 minutes to form a charge transport layer having a thickness of 20 μm. The configuration so far is referred to as a base photoconductor 3-1.

(Protective layer forming coating solution 1)
Two parts each of the compound represented by the following formula (4) and the compound represented by the following formula (5) are dissolved in a mixed solvent of 5 parts of isopropyl alcohol, 3 parts of tetrahydrofuran and 0.3 part of distilled water, and an ion exchange resin ( Amberlyst 15E) 0.05 parts was added and the mixture was stirred at room temperature for 24 hours for hydrolysis.

  0.02 part of aluminum trisacetylacetonate was added to 2 parts of the solution obtained by filtering and separating the ion exchange resin from the hydrolyzed product to obtain a coating solution 1 for forming a protective layer.

(Protective layer forming coating solution 2)
In the protective layer-forming coating solution 1, 2 parts of the compound represented by the following formula (6) instead of the compound represented by the above formula (4), and the following formula (7) instead of the compound represented by the above formula (5) The coating solution 2 for forming a protective layer was prepared in exactly the same manner except that 2 parts of the compound represented by) and 1 part of polyvinyl butyral resin (S-REC BX-L manufactured by Sekisui Chemical Co., Ltd.) were added.

(Electrophotographic photoreceptor 1)
After coating the protective layer-forming coating solution 1 (5 μm) on the base photoreceptor 1-1 (charge transport layer thickness 20 μm) by a ring-type dip coating method and air-drying at room temperature for 10 minutes, at 140 ° C. The electrophotographic photoreceptor 1 was obtained by curing by heating for 40 minutes to form a protective layer having a thickness of 5 μm.

(Electrophotographic photoreceptor 2)
A protective layer (film thickness: 3 μm) is formed on the base photoconductor 1-1 (charge transport layer thickness: 20 μm) using the protective layer forming coating solution 2 in the same manner as the electrophotographic photoconductor 1, and the electrophotographic photoconductor 2 was produced.

(Electrophotographic photoreceptor 3)
A protective layer (thickness 3 μm) is formed on the base photoreceptor 2-1 (charge transport layer thickness 17 μm) using the protective layer forming coating solution 1 in the same manner as the electrophotographic photoreceptor 1, and the electrophotographic photoreceptor. 3 was produced.

(Electrophotographic photoreceptor 4)
A protective layer (thickness 2 μm) is formed on the base photoreceptor 2-1 (charge transport layer thickness 17 μm) using the protective layer forming coating solution 2 in the same manner as the electrophotographic photoreceptor 1, and the electrophotographic photoreceptor. 4 was produced.

(Electrophotographic photoreceptor 5)
A protective layer (film thickness 5 μm) is formed on the base photoconductor 3-1 (charge transport layer thickness 20 μm) using the protective layer forming coating solution 1 in the same manner as the electrophotographic photoconductor 1, and the electrophotographic photoconductor. 5 was produced.

(Electrophotographic photoreceptor 6)
A protective layer (thickness 3 μm) is formed on the base photoreceptor 3 (charge transport layer thickness 20 μm) using the protective layer forming coating solution 2 in the same manner as the electrophotographic photoreceptor 1, and the electrophotographic photoreceptor 6. Was made.

(Electrophotographic photoreceptor 7)
An electrophotographic photoreceptor 7 was formed without forming a protective layer on the base photoreceptor 2-2 (charge transport layer thickness 25 μm).

(Electrophotographic photoreceptor 8)
An electrophotographic photoreceptor 8 was formed without forming a protective layer on the base photoreceptor 2-3 (thickness of charge transport layer: 30 μm).

(Electrophotographic photoreceptor 9)
The electrophotographic photosensitive member 9 was formed without forming a protective layer on the base photosensitive member 2-4 (film transport layer thickness 35 μm).

(Example 1)
The obtained electrophotographic photosensitive member 1 was mounted on an image forming apparatus (Fuji Xerox DCC400 remodeling machine) having the same configuration as that shown in FIG. 1 to produce an image forming apparatus of Example 1. In this image forming apparatus, the exposure apparatus is modified to a self-scanning LED chip type exposure apparatus in which self-scanning LED chips are arranged in a staggered pattern and a light beam is scanned according to image data.

(Examples 2-6 and Comparative Examples 1-3)
The obtained electrophotographic photoreceptors 2 to 6 are mounted on an image forming apparatus (Fuji Xerox DCC400 remodeling machine) having the same configuration as that shown in FIG. Was made. The obtained electrophotographic photoreceptors 7 to 9 are mounted on an image forming apparatus (Fuji Xerox DCC400 remodeling machine) having the same configuration as that shown in FIG. Was made.

(Print test)
Various tests were performed using the image forming apparatuses of Examples 1 to 6 and Comparative Examples 1 to 3. In this printing test, the image forming apparatuses of Examples 1 to 6 and Comparative Examples 1 to 3 were each provided with a self-scanning LED (SLED) as an exposure light source, and the scanning line recording density was set to 1200 dpi. Table 11 shows the conditions for producing the electrophotographic photosensitive member attached to the image forming apparatus. The film thicknesses in Table 11 indicate the sum of the thickness of the charge transport layer of the electrophotographic photoreceptor and the thickness of the protective layer in Examples 1 to 6, and the charge of the electrophotographic photoreceptor in Comparative Examples 1 to 3. The thickness of the transport layer is shown.

  As a printing test, a printing test of about 400,000 cycles was performed to evaluate the image quality. That is, the latent image resolution (dpi) on the electrophotographic photosensitive member and the occurrence of streak density unevenness were evaluated, and a comprehensive determination was made. Note that Fuji Xerox PPC paper (L, A4) was used as continuous printing paper, and was performed at 28 ° C. in an environment of about 80% RH. In this test, the wear rate and lifetime (photoconductor lifetime) of the electrophotographic photoreceptor were also evaluated. The results obtained are shown in Table 12.

  In Table 12, “1200” in the column of the latent image resolution means that a good image was obtained at 1200 dpi. “600” means that the resolution is insufficient at 600 dpi, and the resolution cannot be further increased. The wear rate means an average wear rate per 1,000 cycles of the electrophotographic photosensitive member when the electrophotographic process is repeated for 400,000 cycles. The photoconductor life means the number of repetitions of the electrophotographic process until the gradation, resolution, and density uniformity of the image deteriorates, and the upper limit of the number of repetitions is 980,000. That is, in the column of the photoconductor lifetime in Table 12, “> 1000” indicates that the electrophotographic characteristics of the photoconductor were maintained when the electrophotographic process was repeated 1,000,000 times. This means that the electrophotographic characteristics of the photoreceptor cannot be maintained when the electrophotographic process is repeated 260,000 times.

(Example 7)
(Electrophotographic photoreceptor)
In 170 parts of n-butyl alcohol solution in which 4 parts of polyvinyl butyral resin (S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) is dissolved, 30 parts of an organic zirconium compound (acetylacetone zirconium butyrate) and an organic silane compound (γ-aminopropyltrimethoxy) 3 parts of silane) was added and mixed and stirred to obtain a coating solution for forming an undercoat layer. The obtained coating solution is dip-coated on an aluminum support having an outer diameter of 84 mm, a length of 340 mm, and a wall thickness of 1 mm whose outer peripheral surface has been roughened by a honing treatment, and air-dried at room temperature for 5 minutes, and then supported. The body was heated to 50 ° C. in 10 minutes, placed in a constant temperature and humidity chamber of 50 ° C. and 85% RH (dew point 47 ° C.), and subjected to a humidification hardening acceleration treatment for 20 minutes. Further, the treated support was placed in a hot air dryer and dried at 170 ° C. for 10 minutes to form an undercoat layer having a thickness of 1 μm.

  Next, a mixture consisting of 15 parts of gallium chloride phthalocyanine, 10 parts of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and 300 parts of n-butyl alcohol as a charge generating material in a sand mill for 4 hours. Dispersion treatment was performed to obtain a charge generation layer forming coating solution. The obtained coating solution was dip-coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.

  Next, 40 parts of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), 280 parts of Tetrohydrofuran and After sufficiently dissolving and mixing in 120 parts of toluene, 10 parts of tetrafluoroethylene resin particles having an average primary particle size of 0.2 μm were added and further mixed. Then, the dispersion process was performed for 1 hour with the sand grinder using a glass bead, and the coating liquid for charge transport layer formation in which the tetrafluoroethylene resin particle was disperse | distributed was obtained. The obtained coating solution was dip-coated on the charge generation layer and dried at 130 ° C. for 40 minutes to form a charge transport layer having a thickness of 30 μm, thereby obtaining an intended electrophotographic photoreceptor.

(Image forming device)
Using the obtained electrophotographic photosensitive member, a tandem image forming apparatus having the same configuration as that of FIG. 14 in which the charging device is a contact charging device and the transfer method is an intermediate transfer method was produced. The configuration of the image forming apparatus was the same as that of the color tandem copying machine DocuCenter C400 (manufactured by Fuji Xerox Co., Ltd.) except that the exposure apparatus was modified to the following configuration. That is, a self-scanning LED was applied to the exposure apparatus as an exposure light source, and the number of scanning lines was modified to 1200 dpi.

(Example 8)
An electrophotographic photoreceptor was produced in the same manner as the electrophotographic photoreceptor of Example 7, except that the charge transport layer forming coating solution produced by the following procedure was used. That is, 40 parts of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), 280 parts of tetrohydrofuran and toluene After sufficiently dissolving and mixing in 120 parts, 10 parts of vinylidene fluoride resin particles having an average primary particle size of 0.2 μm were added and further mixed. Then, the dispersion process for 1 hour was performed with the sand grinder using a glass bead, and the coating liquid for charge transport layer formation in which the vinylidene fluoride resin particle was disperse | distributed was prepared.

  A tandem image forming apparatus of Example 8 was produced in the same manner as in Example 7 except that the obtained electrophotographic photosensitive member was used.

Example 9
An electrophotographic photoreceptor was produced in the same manner as the electrophotographic photoreceptor of Example 7, except that the charge transport layer forming coating solution produced by the following procedure was used. That is, 40 parts of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), 280 parts of tetrohydrofuran and toluene After sufficiently dissolving and mixing in 120 parts, 10 parts of amorphous aliphatic polyolefin was added and further mixed. Then, the dispersion process was performed for 1 hour with the sand grinder using a glass bead, and the coating liquid for charge transport layer formation in which the amorphous aliphatic polyolefin was disperse | distributed was prepared.

  A tandem image forming apparatus of Example 9 was produced in the same manner as in Example 7 except that the obtained electrophotographic photosensitive member was used.

(Example 10)
An electrophotographic photoreceptor was produced in the same manner as the electrophotographic photoreceptor of Example 7, except that the undercoat layer was formed using the undercoat layer forming coating solution produced by the following procedure. That is, 100 parts of zinc oxide (average particle size 70 nm, prototype manufactured by Teika) was stirred and mixed with 500 parts of toluene, and 1.5 parts of a silane coupling agent (KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) was added thereto. Stir for hours. Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 2 hours. 60 parts of the obtained zinc oxide after surface treatment, 15 parts of blocked isocyanate (Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, and 15 parts of butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.) Then, it was dissolved in 85 parts of methyl ethyl ketone to obtain a mixed solution. 38 parts of this mixed liquid and 25 parts of methyl ethyl ketone were mixed, and a dispersion liquid was obtained by performing a dispersion treatment for 2 hours with a sand mill using glass beads of 1 mmφ. To the obtained dispersion, 0.005 part of dioctyltin dilaurate was added as a catalyst to obtain a coating solution for forming an undercoat layer. The obtained coating solution was dip-coated on an aluminum support having an outer diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm, followed by drying and curing at 160 ° C. for 100 minutes to form an undercoat layer having a thickness of 20 μm.

  A tandem image forming apparatus of Example 10 was produced in the same manner as in Example 7 except that the obtained electrophotographic photosensitive member was used.

(Comparative Example 4)
An electrophotographic photoreceptor was produced in the same manner as the electrophotographic photoreceptor of Example 7, except that the charge transport layer forming coating solution produced by the following procedure was used. That is, 40 parts of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), 280 parts of tetrohydrofuran and toluene A coating solution for forming a charge transport layer was prepared by sufficiently dissolving and mixing in 120 parts.

  A tandem image forming apparatus of Comparative Example 4 was produced in the same manner as in Example 7 except that the obtained electrophotographic photosensitive member was used.

(Comparative Example 5)
An electrophotographic photoreceptor was produced in the same manner as the electrophotographic photoreceptor of Example 7, except that a charge transport layer having a thickness of 38 μm was formed using the coating liquid for forming a charge transport layer produced by the following procedure. That is, 40 parts of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), 280 parts of tetrohydrofuran and toluene The coating solution for forming a charge transport layer was prepared by sufficiently dissolving and mixing in 120 parts.

  A tandem image forming apparatus of Comparative Example 5 was produced in the same manner as in Example 7 except that the obtained electrophotographic photosensitive member was used.

(Comparative Example 6)
An electrophotographic photosensitive member produced in the same manner as in Example 7 is a color tandem copying machine DocuCenter C400 (made by Fuji Xerox Co., Ltd., exposure apparatus with two laser beams and scanning lines of 1200 × 600 dpi) that has not been modified. The image forming apparatus of Comparative Example 6 was produced. This image forming apparatus uses a laser instead of SLED as an exposure light source.

(Comparative Example 7)
An electrophotographic photosensitive member produced in the same manner as in Comparative Example 4 was mounted on a color tandem copying machine DocuCentre C400 that was not modified to produce an image forming apparatus of Comparative Example 7. This image forming apparatus uses a laser instead of SLED as an exposure light source.

(Print test)
A printing test was performed on the image forming apparatuses of Examples 7 to 10 and Comparative Examples 4 to 7, and each performance (latent image resolution, wear rate, photoconductor lifetime and surface potential fluctuation amount) was evaluated as follows. . The obtained results are shown in Table 13.

  That is, in an environment of high temperature and high humidity (28 ° C., 80% RH), an image forming process in which a series of steps including the following (a) to (c) is set to one cycle (cycle) is performed 300,000 cycles (300,000 times). ) Repeatedly printing images on paper (300,000 sheets) continuously. As paper for continuous printing, Fuji Xerox PPC paper (L, A4) was used.

(A) Each electrophotographic photosensitive member was charged with a scorotron charger having a grid applied voltage of -700V. (B) Using a semiconductor laser with a wavelength of 780 nm, each electrophotographic photosensitive member 1 second after being charged in the step (a) was irradiated with light of 10 mJ / m ² to be discharged. (C) Three seconds after discharging, each electrophotographic photosensitive member was irradiated with 50 mJ / m ² of red LED light to perform static elimination.

  The fluctuation amount (increase amount) of the surface potential is, for each image forming apparatus, the surface potential A [V] of each electrophotographic photosensitive member after the end of one cycle {after the end of (c) step} and 300,000. After the end of the cycle {after the end of the step (c)}, the surface potential B [V] of each electrophotographic photosensitive member was measured, and the variation (BA) was measured. Then, the arithmetic average value of the fluctuation amount (BA) of the surface potential for each image forming apparatus was calculated. In Table 13, “70” in the column of fluctuation amount of the surface potential means that the fluctuation amount of the surface potential was 70V or less.

  In addition, the wear rate was determined for each image forming apparatus by measuring the film thickness of each electrophotographic photoconductor at the beginning and the film thickness of each electrophotographic photoconductor after the end of 300,000 cycles. The body thickness "(hereinafter referred to as" wear wear ") was calculated. Further, the wear rate [nm / kcycle] of each electrophotographic photosensitive member was calculated based on this wear margin. Then, the arithmetic average value of the wear rate for each image forming apparatus was calculated. Here, 1 kcycle means 1,000 cycles.

  The photoconductor lifetime was defined as the lifetime of the electrophotographic photoconductor for each image forming apparatus when the remaining film thickness of the charge transport layer reached 12 to 13 μm. If the film thickness is less than this, potential fluctuations due to wear and image quality defects such as fog become conspicuous and become a problem in practical use. A series of steps consisting of (a) to (c) was repeated, and the number of steps [Kcycle] reaching the above-mentioned level was measured as “photosensitive member lifetime”.

  The latent image resolution was determined for each image forming apparatus as follows. That is, in the image forming apparatus, after the electrophotographic photosensitive member is uniformly charged to −650 V, the surface of the electrophotographic photosensitive member is exposed at the above scanning line recording density to form an electrostatic latent image on the surface of the photosensitive member. did. Further, the electrostatic latent image was developed with a toner image, the developed toner image was transferred to an adhesive tape, and the tape was observed with an optical microscope to determine the resolution.

1 is a schematic configuration diagram illustrating a preferred embodiment of an image forming apparatus of the present invention. It is a perspective view which shows the external appearance of a light source array. It is a LED drive circuit diagram incorporated in the light source array. It is a constant current drive circuit diagram. It is a constant voltage drive circuit diagram. It is a density signal (ΦD) generation circuit diagram. 7 is an operation timing chart of FIG. 6. 4 is an operation timing chart of the LED drive circuit of FIG. 3. It is a characteristic view which shows the LED light emission state of the LED drive circuit of FIG. It is a drive circuit diagram in SLED single-piece | unit. 1 is a schematic cross-sectional view showing an example of a first electrophotographic photosensitive member according to the present invention. It is a schematic cross section which shows the other example of the 1st electrophotographic photoreceptor which concerns on this invention. It is a schematic cross section showing an example of a second electrophotographic photosensitive member according to the present invention. It is a schematic block diagram which shows other suitable embodiment of the image forming apparatus of this invention. It is a schematic block diagram which shows suitable one Embodiment of a process cartridge.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus 106 ... Electrophotographic photosensitive member 108 ... Charging apparatus 110 ... Exposure apparatus 116 ... Developing apparatus 120 ... Transfer apparatus.

Claims (2)

An electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, a charging device for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to electrostatic An exposure device for forming a latent image; a developing device for developing the electrostatic latent image with toner to form a toner image; and a transfer device for transferring the toner image from the electrophotographic photosensitive member to a transfer medium. Prepared,
The electrophotographic photoreceptor has a protective layer on the photosensitive layer,
The exposure apparatus includes a self-scanning LED as an exposure light source. An electrophotographic photosensitive member having a conductive support and a photosensitive layer formed on the conductive support, a charging device for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to electrostatic An exposure device for forming a latent image; a developing device for developing the electrostatic latent image with toner to form a toner image; and a transfer device for transferring the toner image from the electrophotographic photosensitive member to a transfer medium. Prepared,
The electrophotographic photoreceptor has a layer containing at least one selected from the group consisting of a fluororesin, a silicone resin, and a polyolefin resin on the side farthest from the conductive support of the photosensitive layer,
The exposure apparatus includes a self-scanning LED as an exposure light source.

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