JP4493992B2 - Image forming apparatus and process cartridge - Google Patents

Description

  The present invention includes a rotationally driven photoconductor, a charging device that charges the photoconductor, an exposure device that forms an electrostatic latent image on the photoconductor by subjecting the surface of the charged photoconductor to image exposure, and the static An image forming apparatus comprising: a developing device that visualizes an electrostatic latent image as a toner image; a transfer device that transfers the toner image to a transfer material; and a cleaning member that cleans the surface of the photoreceptor after the toner image is transferred. The present invention relates to a process cartridge that is detachably attached to an image forming apparatus main body.

  An image forming apparatus of the above type configured as an electronic copying machine, a printer, a facsimile, or a complex machine of these is well known. In this type of image forming apparatus, it is generally inevitable that hard foreign matters such as carriers in two-component developer, paper dust (talc), and the like adhere to the surface of the photoreceptor. If such foreign matter is sandwiched between the surface of the photoconductor and the cleaning member, the photoconductor surface may receive a large external force due to the foreign matter, and the photoconductor surface may be damaged abnormally such as scratches. If the surface of the photosensitive member is scratched in this way, it is inevitable that the image quality of the toner image transferred to the transfer material deteriorates.

  An image forming apparatus configured so that a brush roller is disposed on the upstream side of the cleaning member with respect to the moving direction of the surface of the photosensitive member, and the brush is brought into contact with the surface of the photosensitive member to remove hard foreign matter attached to the surface of the photosensitive member. Is also well known. However, when such a brush roller is used, the foreign matter removed from the surface of the photosensitive member by the brush roller easily enters between the brushes of the brush roller and is easily accumulated therein. When the hard foreign matter, especially the carrier, accumulated between the brushes contacts the surface of the photosensitive member in this way, the surface may be worn or scratches may be formed on the surface. In addition, the foreign matter accumulated in the brush is repelled toward the cleaning member, the foreign matter is sandwiched between the cleaning member and the surface of the photoconductor, and the foreign matter is pressed against the surface of the photoconductor to damage the photoconductor. There is a risk of being.

  Therefore, a magnet is disposed between the developing device and the transfer device, or between the transfer device and the cleaning member so as to face the surface of the photoconductor, and the carrier adhering to the surface of the photoconductor is sucked by the magnet from the surface of the photoconductor. An image forming apparatus that removes a carrier has been proposed (see Patent Documents 1 and 2). However, according to this configuration, hard foreign matters other than the carrier, such as paper dust, cannot be removed from the surface of the photoreceptor.

JP-A-6-35372 JP-A-6-124024

  The object of the present invention is to remove the hard foreign matter adhering to the surface of the photoconductor more efficiently than before, and to effectively suppress the defect that the photoconductor surface is scratched. An object of the present invention is to provide an apparatus and a process cartridge that is detachably attached to an image forming apparatus main body.

  In order to achieve the above object, according to the present invention, in the image forming apparatus of the type described at the beginning, with respect to the moving direction of the surface of the photosensitive member, it is downstream of the transfer device and upstream of the cleaning member. A scraping roller that scrapes hard foreign matter adhering to the surface of the photoconductor is provided facing the surface of the photoconductor, and the scraping roller includes a support member and a plurality of base ends fixed to the support member. These fins are arranged at intervals in the circumferential direction of the support member, and the fins are composed of brushes that are solidified leaving their tips. An image forming apparatus is proposed (claim 1).

  Further, in the image forming apparatus according to claim 1, it is advantageous that the brush is solidified leaving 1 to 3 mm at a tip portion thereof (claim 2).

  Further, in the image forming apparatus according to claim 1 or 2, it is advantageous that the amount of biting of the fin into the photosensitive member is +1 mm to -0.2 mm (claim 3).

  4. The image forming apparatus according to claim 1, wherein the photoconductor includes a crosslinkable charge transport material containing a reactive hydroxyl group, a thermosetting resin monomer, and a thermosetting interface. An electrophotographic photosensitive member having a photosensitive layer using a resin obtained by a crosslinking reaction with an activator as an outermost layer is advantageous.

  Furthermore, in the image forming apparatus according to any one of claims 1 to 4, the cleaning member includes a cleaning blade pressed against the surface of the photoreceptor, and reinforcing members are attached to both surfaces of the cleaning blade. It is advantageous (claim 5).

  Further, in the image forming apparatus according to claim 5, it is advantageous that the reinforcing member is made of a film having a thickness of 25 to 300 μm (claim 6).

  Furthermore, in the image forming apparatus according to claim 5 or 6, the cleaning blade has a JIS A hardness of 58 ° to 80 ° and a contact pressure of 15 to 30 g / cm. It is advantageous if it is pressed against the surface of the photoreceptor in the direction of the counter.

  In the image forming apparatus according to any one of claims 5 to 7, it is advantageous that the cleaning blade is made of a strip-shaped rubber having a thickness of 1.5 to 3 mm (claim 8).

  Furthermore, in the image forming apparatus according to any one of claims 5 to 8, the cleaning blade is used in a state in which one edge portion on a front end side thereof is in pressure contact with the surface of the photoreceptor, and the cleaning blade is used. It is advantageous that the tip end side of the cleaning blade is used even in a state where it is pressed against the surface of the photosensitive member, and the base end side opposite to the tip end side of the cleaning blade is attached to the holder. Claim 9).

  Further, in the image forming apparatus according to any one of claims 1 to 9, it is advantageous that a powdery lubricant is applied to the surface of the photoreceptor, or a lubricant is added to the outermost layer of the photoreceptor. (Claim 10).

  Furthermore, in the image forming apparatus according to any one of claims 1 to 10, the toner is produced by a polymerization method as a developer toner that visualizes an electrostatic latent image, and has an average circularity of 0.95 to 0. It is advantageous to use a toner having an average particle diameter of 4 to 8 μm.

  In order to achieve the above object, according to the present invention, at least the photosensitive member according to any one of claims 1 to 11 and a scraping roller are integrally assembled so as to be detachable from the main body of the image forming apparatus. A process cartridge to be mounted is proposed (claim 12).

  According to the present invention, with a simple configuration, it is possible to efficiently remove hard foreign matters attached to the surface of the photoconductor, and it is possible to effectively suppress a problem that the photoconductor surface is damaged by the hard foreign matter.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  The image forming apparatus shown in FIG. 1 has a photoconductor 1 formed in a drum shape, and this photoconductor 1 is driven to rotate clockwise in FIG. At this time, the charging device 2 charges the surface of the photoreceptor 1 to a predetermined polarity. Although FIG. 1 shows a charging device comprising a corona discharger, it is also possible to use a charging device comprising a charging roller or the like that is in contact with or close to the surface of the photoreceptor. It is also possible to employ a photoreceptor formed in an endless belt shape that is wound around a plurality of support rollers and rotated.

  The charged surface of the photosensitive member is exposed to an image by the exposure device 3, whereby an electrostatic latent image is formed on the photosensitive member 1, and the electrostatic latent image is visualized as a toner image by the developing device 4. As the exposure apparatus 3, for example, an apparatus using an LD element or an LED array as a light source is used. The developing device 4 shown here includes, for example, a developing case 5 containing a dry two-component developer D having toner and a carrier, and a developing sleeve 6 that carries and conveys the developer D by the action of magnetic force. The toner in the developer carried on the developing sleeve 6 is electrostatically transferred to the electrostatic latent image on the photoreceptor 1 to form a toner image.

  In the illustrated example, the photosensitive member 1 is negatively charged by the charging device 2 and its charged surface is selectively exposed by the exposure device 3 to form an electrostatic latent image. Becomes an image portion, that is, an electrostatic latent image, and a non-exposed photoreceptor portion becomes a background portion. At that time, the contrast voltage, which is the potential difference between the image portion and the background portion, may be 400 to 500 V, for example. For example, when the surface potential of the background portion is −800 V, the surface potential of the image portion is set to −300 V or less, preferably −200 V or less, and the developing sleeve 6 of the developing device 4 has, for example, −650 V to − A developing bias of about 700V is applied.

  Below the photoreceptor 1, a paper feeding device 7 that accommodates a recording medium P such as transfer paper or an OHP film is arranged. The recording medium P sent out from the paper feeding device 7 includes the photoreceptor 1 and the transfer device 8. At this time, the toner image on the photoreceptor 1 is transferred to the recording medium P by the action of the transfer device 8. The recording medium P constitutes an example of a transfer material to which a toner image on the photoreceptor 1 is transferred. As will be described later, an intermediate transfer member can also be used as a transfer material.

  The recording medium P that is in close contact with the photosensitive member 1 is electrostatically separated from the surface of the photosensitive member 1 by the separating device 9, and then the recording medium P passes through the fixing device 10. The upper toner image is fixed on the recording medium P.

  Further, transfer residual toner adhering to the surface of the photoreceptor after the toner image is transferred to the recording medium P is removed by the cleaning blade 12 of the cleaning device 11. The cleaning device 11 of this example has a cleaning case 13 in addition to the cleaning blade 12. The cleaning blade 12 is fixedly supported by the cleaning case 13 at the base end side, and the edge portion at the tip end side is in pressure contact with the surface of the photoconductor to scrape and remove the transfer residual toner adhering to the surface of the photoconductor. Thus, the cleaning blade 12 constitutes an example of a cleaning member that cleans the surface of the photoreceptor after the toner image is transferred.

  By the way, as described above, it is generally unavoidable that the carrier in the two-component developer D and hard foreign matters such as paper dust adhere to the surface of the photoreceptor 1. That is, a phenomenon frequently occurs in which the carrier in the developer leaves the developing sleeve 6 and is attracted by the electrostatic force of the photosensitive member 1 and adheres to the surface of the photosensitive member. The main causes of the carrier separation are (1) the magnetic force of the developing device is weak, (2) the charging potential of the photosensitive member is high, (3) the potential difference between the charging potential and the developing bias is large, and (4) the small-diameter carrier. (E.g., 40 [mu] m or less), (5) rotation of the developing sleeve is fast, (6) the developer has too many spikes, and the like. This adhesion phenomenon can be improved by optimizing each device, but it is difficult to eliminate it.

  When the carrier adhering to the surface of the photoconductor is sandwiched between the cleaning blade and the surface of the photoconductor as described above, the surface of the photoconductor is scratched by the carrier, and the edge of the cleaning blade is damaged, resulting in photosensitivity. The risk of poor cleaning of the body surface is inevitable.

  Therefore, in the image forming apparatus of this example, with respect to the movement direction of the photosensitive member surface, it is downstream of the transfer device 8 and is opposed to the photosensitive member surface portion upstream of the cleaning member composed of the cleaning blade 12. A scraping roller 14 is provided to scrape hard foreign matter adhering to the surface of the photosensitive member. As shown in FIGS. 1 to 3, the scraping roller 14 includes a support member 15 and a plurality of fins 16, and a base end portion of each fin 16 is fixed to the support member 15, and these The fins 16 are arranged at intervals in the circumferential direction of the support member 15. The length L of the fin 16 is set to be equal to or slightly longer than the length of the developing area in the axial direction of the photoreceptor 1. The length L of each fin 16 is set to be approximately equal to the length of the cleaning blade 12. The support member 15 of the scraping roller 14 is made of metal, resin, a material obtained by superposing a resin on a metal, or a paper tube. Each fin 16 shown in FIG. 2 is made of a film, and each fin 16 shown in FIG. 3 is made of a brush. A film and a brush can be used in combination. Thus, the fin 16 is comprised from at least one of a film and a brush.

  In the image forming apparatus shown in FIG. 1, the scraping roller 14 is disposed in the cleaning case 13 of the cleaning device 11. Ends in the longitudinal direction of the support member 15 of the scraping roller 14 are rotatably supported on the side walls of the cleaning case 13, and the scraping roller 14 is rotated clockwise in FIG. It is driven to rotate in the counter direction with respect to the rotation direction of the body 1. The scraping roller 14 is rotationally driven so that the portion of the scraping roller 14 facing the surface of the photoconductor moves in a direction opposite to the moving direction of the surface of the photoconductor. At that time, the rotation speed of the scraping roller 14 is set to 80 to 300 rpm, usually 180 to 250 rpm. As shown in the illustrated example, the scraping roller 14 is preferably disposed in the cleaning case 13, but the scraping roller 14 is provided outside the cleaning case, and the scraping roller 14 is configured to rotate. You can also.

  When a hard foreign substance such as a carrier or paper dust (talc) adhering to the surface of the photoreceptor reaches the area where the scraping roller 14 is provided, the foreign substance is scraped off by the fin 16 of the rotating scraping roller 14. . At this time, since the fins 16 are arranged at a certain interval in the circumferential direction of the support member 15, a large amount of foreign matter removed from the surface of the photoreceptor is not accumulated between the fins 16. Without leaving the scraping roller 14 easily. For this reason, unlike the conventional brush roller, a large amount of foreign matter enters between the brushes and is not accumulated here, and the surface of the photoconductor is damaged by the hard foreign matter transferred to the scraping roller 14. And wear on the surface of the photoreceptor is not promoted. In addition, it is possible to prevent a problem that hard foreign matter is repelled between the edge portion of the cleaning blade 12 and the surface of the photosensitive member.

  In the conventional brush roller, since the brush is implanted over the entire peripheral surface of the support member, when the hard foreign matter adhered on the photosensitive member is removed by the brush roller, the foreign matter enters between the brushes, It will be accumulated here. On the other hand, in the scraping roller 14 of this example, since the fins 16 are arranged at intervals in the circumferential direction of the support member 15, a large amount of foreign matter is not accumulated between the fins.

  In addition, even if a very small amount of foreign matter moves toward the edge of the cleaning blade 12 without removing the hard foreign matter by the scraping roller 14, a gap is formed between the edge and the surface of the photoreceptor. As described above, by keeping the cleaning blade 12 in close contact with the surface of the photoconductor, it is possible to prevent the surface of the photoconductor from being damaged. However, since the carrier is easily transported continuously, it is desirable that the unevenness of the hard foreign matter such as the carrier and paper dust attached to the photoconductor does not occur in the longitudinal direction of the photoconductor 1.

  Further, the scraping roller 14 serves to remove a part of the transfer residual toner in addition to the hard foreign matter adhering to the surface of the photoconductor, thereby reducing the burden on the cleaning blade 12 and increasing the cleaning blade 12's height. The cleaning property can be maintained and the durability of the cleaning blade 12 can be extended. At this time, since the toner also serves as a lubricant between the cleaning blade 12 and the surface of the photoreceptor, the scraping roller 14 is configured to remove an excessive amount of toner from the surface of the photoreceptor. That is not preferable.

  Further, in order to more efficiently remove the carrier made of iron powder or the like adhering to the surface of the photoconductor, the electromagnet or the permanent magnet is downstream of the developing device 4 with respect to the moving direction of the photoconductor surface, It can also be disposed opposite the surface of the photoreceptor surface upstream of the cleaning blade 12.

  Further, in order to more effectively remove the foreign matter transferred from the photosensitive member 1 to the scraping roller 14 from the scraping roller 14, as shown in FIG. 1, for example, a flicker member fixed to a cleaning case 13 17 may be provided so that the fins 16 of the rotating scraping roller 14 are struck against the flicker member 17 so that foreign matter and toner adhering to the fins 16 are removed. The amount of biting of the flicker member 17 into the fin 16 is preferably within 1 mm. The flicker member 17 can be constituted by, for example, a flexible bar made of conductive rubber, a carbon brush having a width of 1 to 2 mm in which conductive fibers are closely planted, or the like. Those that are too hard are not preferred.

  The fins 16 shown in FIG. 2 are made of a film, but it is preferable to use a resin film as the film. The thickness of the film is 25 to 150 μm, and the width (corresponding to the length of brush ears) is suitably 1.5 to 5 mm. By setting the film thickness to 25 to 150 μm, the amount of film deflection can be reduced and damage to the surface of the photoreceptor even if the amount of residual powder consisting of foreign matter and transfer residual toner adhered to the surface of the photoreceptor is large. Can be reduced, and foreign matters can be efficiently removed. Further, by reducing the width of the film to 1.5 to 5 mm, it is possible to satisfactorily scrape off foreign matter and toner even if it is a thin film.

In addition, it is possible to make it difficult for the carrier and toner to adhere to the film by conducting a conductive treatment on the film constituting the fin 16 and dropping it to the ground. The volume resistivity of the film is 10 ¹⁰ Ω · cm or less, usually 10 ³ to 10 ⁸ Ω · cm.

  The use of a resin film as the fin 16 makes it difficult for the photoreceptor 1 to be scratched, while preventing residual powder such as carrier and toner on the photoreceptor 1 from coming off in the longitudinal direction and causing unevenness. This is because it can be effectively removed. As the film thickness decreases, the film undergoes bending due to the resistance of the toner. For this reason, the scraping effect of toner and carrier is reduced. Accordingly, the lower limit of the film thickness is about 25 μm, preferably a film having a thickness of 50 μm or more. On the other hand, as the thickness of the film increases, the effect of removing toner and carrier increases. However, when the film hits the photoreceptor, the photoreceptor is damaged, so that the photoreceptor must be replaced early. Therefore, when a film having a film thickness is used, the film rubs against the surface of the photoconductor 1 and scrapes or scratches, so that the film is not in contact with the photoconductor 1 so that the film does not contact the photoconductor. For example, it can be arranged away from 1 by about 0.1 to 0.2 mm.

  Further, the distance between the base end portions of the fins 16 made of a film is desirably 1.5 to 5 (mm), and preferably 2 to 4 mm. When the amount of toner is large, if the width between the films is narrow, the fluidity of the toner deteriorates, and the toner accumulates between the films and does not flow. That is, it becomes difficult to efficiently remove the toner. Therefore, it is desirable that the distance between the films be large, and at least 1.5 mm, preferably 2 mm or more, and 5 mm is almost sufficient.

  Even when a brush is used as the fin 16, the brush is fixed to the support member 15 at regular intervals as shown in FIG. After fixing the brush, the brush may be trimmed to the required length.

As the material for the fins made of brushes, resin fibers such as nylon, polyester, and polyethylene, and carbon fibers are used. The material used for the brush roller can be used as it is for the fiber thickness. That is, the fiber thickness is, for example, 5 to 20 (D / F), the brush density is 10,000 to 100,000 (lines / inch ² ), and the fiber length is ² to 5 mm. D is denier, F is a filament, and represents a unit of fiber thickness.

  When using a brush as a fin, it is desirable to solidify (solidify) with resin, leaving 1 to 3 mm at the tip of the brush. This is because the brush is rubbed against the photosensitive member 1 so that a gap is formed in the brush, and hard foreign matters such as a carrier enter here, and it is difficult to escape between the brushes. However, when the length of the brush is 1 mm or less, it is only necessary to fix it. The material that solidifies the base of the brush with a certain width is not particularly limited as long as the material does not fuse the toner. It may be glue or lacquer. Moreover, the width | variety of the brush of 1 row shall be about 1-3 mm, and it fixes over the length equivalent to a cleaning blade in the circumferential direction of the supporting member 15 by 2-5 (mm) space | interval.

The film-like or brush-like fin 16 described above can be used without being surface-treated as it is, but the surface may be coated with a conductive thin film. For example, SiO film, carbon and silver particles, paint dispersed with the same particles, SnO film, etc., which have a resistivity of the order of 10 ⁸ Ωcm or less, and have no chemical effect on the toner or other members. There is no particular limitation. By conducting a conductive process and grounding the fins (electrically 0 volts), the separation of the fins of the toner, particularly the carrier, is improved.

  It is appropriate that the amount of biting of the fins 16 into the photoconductor is +1.0 to -0.2 mm. The biting amount +1.0 mm indicates that the biting depth into the photoconductor is 1.0 mm, and -0.2 mm indicates that there is a gap of 0.2 mm between the surface of the photoconductor. That is, the fin 16 is preferably used between a state where the fin 16 is bent in contact with the photosensitive member and a state where a 0.2 mm gap is formed between the fin 16 and the photosensitive member. This range is set depending on the hardness and thickness of the fins, and the thickness is set so that a gap is formed between the fin and the photoconductor so that the photoconductor is not damaged.

  The fin 16 is attached by forming a slit that embeds the fin in the support member 15, inserting the fin into the slit, and using an instant adhesive (for example, Aron Alpha = trade name of Toagosei Co., Ltd.) What is necessary is just to fix using a liquid adhesive. In the case of brush-like fins, a method of fixing the brush to a sheet-like support with an adhesive (for example, strong cemedine (trade name)) or the like, and fixing the support to the support member 15 with a double-sided tape or an adhesive But you can do it. As the support, acrylic resin, vinyl chloride resin, polycarbonate resin, delrin, ebonite, bakelite and the like can be used. Although it is sufficient if the thickness of the support is 1 to 2 mm, it may be larger.

As the fin 16, other than the above-described film and brush can be used. For example, a member having elasticity such as rubber having a thickness of 0.5 to 2 mm can be used. The rubber includes urethane rubber, fluorine rubber, silicone rubber, etc., but since the toner may be fused, thermosetting resin, thermoplastic resin, paraxylylene, aC (amorphous carbon), SiO on the rubber surface. It is desirable to overcoat a thin film such as SnO ₂ to such an extent that the elasticity is not lost. The rubber hardness is about 30 ° to 70 ° in JIS-A hardness.

  The scraping roller 14 shown in FIGS. 1 to 3 has the fin 16 embedded in the support member 15 at a substantially right angle, but the fin 16 is inclined obliquely to the support member 15 as shown in FIG. It can also be fixed in a state.

  Next, the configuration of the photoreceptor 1 will be described. The photoreceptor 1 of this example is a digital function-separated organic photoreceptor. The functionally separated type organic photoreceptor is composed of an undercoat layer, a charge generation layer, and a charge transport layer in this order on a conductive support, and further has a charge transport layer with higher wear resistance formed on the outermost surface. The photosensitive member has a structure (the photosensitive layer has a three-layer structure). The basic structure of a normal photosensitive member 1 is as shown in FIG. 5 and can be used. However, in the image forming apparatus of this example, the photosensitive member 1 shown in FIG. 6 is used. That is, the photoreceptor 1 of this example includes a conductive support 101, an undercoat layer 102, a charge generation layer 103, a charge transport layer 104, and a charge transport layer 105. In order to distinguish, 104 is the charge transport layer A and 105 is the charge transport layer B. Hereinafter, each item will be described in detail.

Conductive except for those support special, general electroconductive substrate 101 used in the photosensitive member 1 for an image forming apparatus drum shape is the main, the material as a conductive support of the photoconductor A JIS standard 3003 aluminum alloy excellent in required mechanical strength, workability (cutability), electrical characteristics, etc. is preferably used. The support made of aluminum is cut so that the properties such as roundness, straightness, and runout fall within the specified values, and the surface finish (super-finished or mirror-finished surface) is finally achieved to have a surface roughness of about 1 to 10 μm. Finishing).

The conductive support 101 of the organic photoreceptor is generally processed to have a thickness of 0.6 to 3 mm and an outer diameter of about 25 to 100 (mm). It is sufficient that the electrical resistance of the conductive support 101 is 10 ⁶ Ω · cm or less in terms of volume resistivity, and if the volume resistivity is on the order of about 10 ⁹ Ω · cm, it can be used without damaging the electrophotographic characteristics. it can. As the electric resistance increases, the movement of carriers is limited, so that the light attenuation characteristic becomes gradual and the electrophotographic characteristics deteriorate. In aluminum, an insulating oxide film (Al ₂ O ₃ ) is formed immediately after cutting, but the oxide film formed in the atmosphere is thin, weak, and non-uniform, so that the charge injection blocking film (as a charge injection layer) It is insufficient as a blocking film. Therefore, an insulating thin film (undercoat layer and intermediate layer) that can be alumite-treated, or can maintain a charge (at the time of minus charge, holes) at the end of development (up to several tens of msec) until charging is completed. It is desirable to form. Note that since the alumite layer has a high resistance, the residual potential is likely to accumulate as the film thickness increases. For this reason, it is necessary to control the film thickness to about several tens to several hundreds of meters, and the cost is high. Therefore, practical application is limited to some photoconductors, and in most photoconductors, an undercoat layer made of a resin in which inorganic fine particles are dispersed is often formed.

The purpose of forming the undercoat layer 102 is to prevent charge injection from the conductive support side during charging, and incident light during image formation is reflected by the conductive support and re-enters the photosensitive layer. This is to prevent the image from being disturbed and to secure the charging potential, electrostatic contrast and uniform image (moire prevention, dot pattern reproduction, etc.) necessary for image formation. Therefore, it is indispensable for a digital image forming apparatus. The film thickness for preventing charge injection and preventing deterioration of electrophotographic characteristics is about 1 to 10 μm, and preferably 3 to 6 μm.

The subbing layer is set to a volume resistivity of the order of 10 ¹⁰ to 10 ¹³ Ω · cm, but as the film thickness increases, carriers formed by image formation (electrons at the time of negative charging) are subbing layer 102. It takes time to move to the conductive support 101 side. Therefore, the more frequently it is used, the more electrons accumulate at the interface of the charge generation layer, and the residual charge accumulates in the photosensitive layer, which tends to cause deterioration of the light attenuation characteristic, increase in charging characteristic potential, and positive charging. Change occurs, image density is lowered, afterimages are generated, and further, a problem such that the carrier during development is likely to adhere to the photoreceptor 1 is caused. On the other hand, as the film thickness is reduced, unevenness is likely to be formed in the coating film, and charge injection from the conductive support (in this case, positive charges (holes)) is likely to occur, so that charging is insufficient. It becomes a noisy image. Therefore, it is not preferable to increase the film thickness, and 3 to 6 μm is preferable.

  The resin used for the undercoat layer includes water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane resins, melamine resins, and alkyd-melamines. Examples thereof include curable resins that form a three-dimensional network structure, such as resins and epoxy resins. Further, fine powders such as metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like, or metal sulfides and metal nitrides may be dispersed and contained. These undercoat layers can be formed using an appropriate solvent and coating method. Further, a metal oxide layer formed by, for example, a sol-gel method using a silane coupling agent, a titanium coupling agent, a chromium coupling agent or the like as the undercoat layer is also useful.

Charge generation layer The charge generation layer 103 is a layer that generates electron-hole pairs necessary for image formation by photons irradiated from the exposure apparatus 3 shown in FIG. 1, and the sensitivity increases as the amount of electron-hole pairs generated increases. Tend to be high. In order to smoothly move electrons or holes generated by image exposure toward the surface or the charge of the conductive support 101, the charge transport layer 104 or the undercoat layer 102 in contact with the charge generation layer 103 It is desirable that the barrier at the interface be as low as possible, and any material can be used regardless of whether it is an inorganic material or an organic material, as long as the photosensitive material satisfies this condition.

  Examples of the charge generating material of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous silicon. Further, the organic charge generating material includes phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squaric acid methine pigments, azo pigments having a carbazole skeleton, azo pigments having a triphenylamine skeleton, An azo pigment having a diphenylamine skeleton, an azo pigment having a dibenzothiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazol skeleton, an azo pigment having a bis-stilbene skeleton, an azo pigment having a distyryl oxadiazol skeleton Azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and the like Azomethine pigments, indigoid pigments, bisbenzimidazo - there and Le pigments.

  The binder resin used as necessary for the charge generation layer 103 is polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N. -Vinylcarbazole, polyacrylamide, etc. are used. These binder resins can be used alone or as a mixture of two or more. Further, a low molecular charge transport material (electron transport material or hole transport material) may be added as necessary.

  Examples of the electron transporting material include chloroanil, bromanyl, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron accepting substances such as nitrodibenzothiophene-5,5-dioxide. These electron transport materials can be used alone or as a mixture of two or more.

  Examples of the hole transport material include electron donating materials shown below. For example, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, styrylanthracene, styryl Examples include pyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives. These hole transport materials can be used alone or as a mixture of two or more.

  The charge generation layer 103 is formed of a charge generation material, a solvent, and a binder resin as main components, and includes any additive such as a sensitizer, a dispersant, a surfactant, and silicone oil. May be included.

  As a method for forming the charge generation layer 103, a vacuum thin film manufacturing method and a casting method from a solution dispersion system can be mentioned. As the former method, a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is used, and the above-described inorganic materials and organic materials can be satisfactorily formed. Further, in order to provide the charge generation layer 103 by the casting method, if the inorganic or organic charge generation material described above is necessary, a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone is used together with a binder resin to form a ball mill, an atom, or the like. It can be formed by dispersing with a lighter, sand mill or the like, and applying the solution after diluting the dispersion appropriately. The coating can be performed using a dip coating method, a spray coating method, a bead coating method, or the like.

  The film thickness of the charge generation layer 103 provided as described above is suitably about 0.01 to 5 μm, preferably 0.05 to 2 μm. Usually, it is applied to a thickness of 0.1 to 0.3 μm. If the film thickness is too thin, poor sensitivity occurs, but if it is too thick, light attenuation deterioration due to space charge and a residual potential increase occur, leading to image quality deterioration such as image density reduction and resolution reduction.

Charge transport layer A
The charge transport layer A104 is formed to ensure a sufficient charging potential and a sufficient contrast potential necessary for image formation. The charge transport layer A104 generally has little polarity dependence, and polycarbonate resin (A type, C type, Z type, etc.), styrene resin, amorphous having a volume resistivity of about 10 ¹⁴ to 10 ¹⁸ Ω · cm. A polyolefin resin or the like is used as a binder resin, and a donor, an antioxidant, a leveling material, and the like are further added. As the low-molecular charge transport material constituting the charge transport layer A104, an oxazole derivative, an oxadiazole derivative, an imidazole derivative, a triphenylamine derivative, an α-phenylstilbene derivative, a toniphenylmethane derivative, an anthracene derivative, or the like can be used. .

On the other hand, as the polymer charge transport material, the following known polymer charge transport materials can be used. For example,
1) Polymers having a carbazole ring in the main chain and / or side chain include, for example, poly-N-vinylcarbazole, JP-A-50-82056, JP-A-54-9632, JP-A-54- There are compounds described in JP-A-11737 and JP-A-4-183719.
2) Examples of the polymer having a hydrazone structure in the main chain and / or side chain include compounds described in JP-A-57-78402 and JP-A-3-50555.
3) Examples of the polysilylene polymer include compounds described in JP-A-63-285552, JP-A-5-19497, and JP-A-5-70595.
4) Polymers having a tertiary amine structure in the main chain and / or side chain include, for example, N, N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-13061, JP-A-1 JP-A-1-19049, JP-A-1-1728, JP-A-1-105260, JP-A-2-167335, JP-A-5-66598, JP-A-5-40350, etc. There is.
5) Other polymers include, for example, formaldehyde condensation polymers of nitropyrene, and compounds described in JP-A-51-73888 and JP-A-56-150749.
The polymer having an electron donating group is not limited to the above-mentioned polymer, but also a copolymer of known monomers, a block polymer, a graft polymer, a star polymer, and for example, JP-A-3-109406. It is also possible to use a crosslinked polymer having an electron donating group as disclosed in the publication.

  As the polymer charge transport material, polycarbonate having a triarylamine structure in the main chain and / or side chain is effectively used.

  On the other hand, examples of the polymer compound that can be used as the binder component include polystyrene, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene / maleic anhydride copolymer, polyester resin, polyvinyl chloride, and chloride. Vinyl / vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, polycarbonate resin (bisphenol A type, bisphenol C type, bisphenol Z type or copolymers thereof), cellulose acetate resin, ethyl cellulose resin, polyvinyl Thermoplastic or thermal such as butyral, polyvinyl formal, polyvinyl toluene, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin Including but of resin, but is not limited thereto. These polymer compounds can be used singly or as a mixture of two or more kinds, or copolymerized with a charge transport material.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, toluene, xylene, and the like. Examples include aromatics, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate, but it is desirable to avoid the use of halogen-based solvents in consideration of environmental destruction.

  In addition, for the purpose of improving the environmental resistance and preventing the decrease in sensitivity and the increase in residual potential, an antioxidant is added to each layer such as a charge generation layer, a charge transport layer, an undercoat layer, a protective layer, an intermediate layer, Plasticizers, lubricants, UV absorbers, and low molecular charge transport materials can be added.

  The film thickness of the charge transport layer A104 is set in the range of about 10 to 40 μm, but is preferably in the range of 10 to 30 μm, and is set to about 15 to 25 μm when high resolution is desired. When the film thickness is 10 μm or less, the electrostatic capacity becomes too large, and it becomes difficult to ensure the surface potential necessary for image formation. For image formation, it is desirable that the contrast potential is at least 250 V or more. However, if it is 10 μm or less, it becomes difficult to secure the contrast potential, the usable time becomes extremely short due to the abrasion of the photosensitive layer, and further, the contrast potential can be secured. It becomes difficult. On the other hand, when the film thickness is reduced, it is difficult to produce a photosensitive layer having a uniform film thickness, and image defects due to density unevenness and pinholes occur, resulting in an image quality with a poor SN ratio. When the thickness of the charge transport layer A104 is increased, the electrostatic capacity is reduced, so that a sufficient surface potential is ensured and an image quality with a good SN ratio can be obtained. However, as the thickness increases, structural defects relatively increase in the photosensitive layer, which hinders the movement of carriers (here, holes) and tends to cause undesirable phenomena such as afterimages.

Charge transport layer B
In order to increase the durability of the photoreceptor, it is desirable to form a charge transport layer having further abrasion resistance on the photosensitive layer. The charge transport layer is used so as not to form a barrier that causes a residual potential between the stacked layers. The lower the barrier, the better the electrophotographic properties are maintained because electrons or holes can move more smoothly. There are many wear-resistant materials, both inorganic and organic. Although it is desirable to adjust the electrical resistance of the layer laminated for use in the photoreceptor to about 1 × 10 ¹² to 10 ¹⁴ Ωcm, it is possible to form a barrier against holes or electrons simply by specifying the electrical resistance. With repeated use, residual potential is inevitably accumulated, and good image quality cannot be obtained. By constituting as a photosensitive layer (hole transfer type charge transport layer), it is possible to lower the above-mentioned barrier, so that the accumulation of residual potential can be greatly improved. In this example, a thermosetting resin is used as the charge transport layer material as the wear-resistant photosensitive layer. Examples of using thermosetting resins can be found in disclosed examples such as JP-A Nos. 05-181299, 05-05357, and 05-150461.

  In the image forming apparatus of this example, a thermosetting resin is used. At that time, as a means for reducing the friction coefficient of the photoreceptor, it is obtained by cross-linking a fluorosurfactant having a reactive hydroxyl group as a cross-linking resin. The resin used is used. That is, the photoreceptor of this example is a photosensitive layer using a resin obtained by a crosslinking reaction of a crosslinkable charge transport material containing a reactive hydroxyl group, a thermosetting resin monomer, and a thermosetting surfactant. In the outermost layer. The content of the crosslinkable charge transport material is preferably 7.5 wt% or more in the outermost surface layer of the photoreceptor.

The thermosetting resin cures and increases in hardness as the heating temperature increases. In many cases, however, sufficient hardness cannot be achieved by simply applying heat. For this reason, when the cross-linked resin material is measured by DSC (differential thermal analysis), by selecting and using a material that does not have an endothermic peak up to the decomposition temperature, it is possible to eliminate poor curing and improve wear resistance. It was confirmed by experiment that it was possible. In addition, in the case where the outermost surface layer of the photoreceptor using a crosslinked resin is formed, an image is likely to flow due to an environmental change due to a change in temperature and humidity, and this phenomenon is particularly remarkable in a siloxane crosslinked resin. However, problems such as image flow can be improved by selecting a cross-linked resin that has a transmittance of 95% or more at 3200-3800 (cm ⁻¹ ) in IR (far infrared analysis). confirmed.

  Problems that occur depending on environmental conditions such as image flow and resolution degradation can be improved by film formation conditions, but any one of melamine resin, thermosetting acrylic resin, epoxy resin, phenoxy resin, and phenol resin can be used. By selecting or combining, it is possible to make it difficult to cause problems. Any of these materials are available.

  In the image forming apparatus, corona products such as ozone and nitrogen oxides act on the photoconductor when charging the photoconductor to increase the coefficient of friction, causing various problems such as resolution degradation, poor cleaning, and photoconductor degradation. . Therefore, in order not to cause these problems, a fluorine-based surfactant is used for the purpose of improving the wear resistance by suppressing the increase in the friction coefficient and promoting the crosslinking of the charge transport layer. Yes. A well-known material can be used for the fluorine-type surfactant in this example. For example, as a copolymer containing a (meth) acrylate having a fluoroalkyl group described in JP-A-07-068398, for example, described in JP-A-60-212410 and JP-A-60-228588 A block copolymer composed of a vinyl-type monomer not containing fluorine and a fluorine-containing vinyl-type monomer, as a fluorine-based graft polymer, for example, a methacrylate macromonomer having polymethyl methacrylate as a side chain described in JP-A-60-187721 And a comb-type graft polymer obtained by copolymerizing a (meth) acrylate having a fluoroalkyl group. These fluororesins are commercially available as paint additives. For example, fluorine-containing random copolymers are commercially available from Asahi Glass Co., Ltd. as resin surface modifiers SC-101 and SC-105. As the fluorine-containing block copolymer, Modiper F series (for example, F100, F110, F200, commercially available from Nippon Oil & Fats Co., Ltd.) as a block copolymer comprising a fluoroalkyl group-containing polymer segment and an acrylic polymer segment. F210, F2020). Fluorine-based graft polymers are commercially available from Toa Gosei Co., Ltd. under the names Aron GF-150 and GF-300. These surfactants are used as a crosslinked resin component. In particular, a copolymer of a methacrylic acid ester and a fluoroalkyl acrylate is effective.

  When a crosslinkable resin is used, it is necessary to bond a charge transporting functional group to the crosslinkable resin to such an extent that photoinduced charge carriers can move in the protective layer, or to blend a polymer charge transport material. If it is possible to mix the low molecular charge transport material and the cross-linked resin, the low molecular charge transport material may be mixed, but it cannot be fixed in the protective layer, and the low molecular component is on the surface. May precipitate. By using the above-described polymer charge transport material for such cases, precipitation can be prevented and sensitivity characteristics can be improved.

  If necessary, an appropriate antioxidant, a plasticizer, a lubricant, a low molecular compound such as an ultraviolet absorber and a leveling agent can be added to the charge transport layer. These compounds can be used alone or as a mixture of two or more. The amount of the low molecular compound used is 0.1 to 50 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the resin component, and the amount of the leveling agent used is 100 parts by weight of the resin component. About 0.001 to 5 parts by weight is appropriate.

  As a method for forming the outermost surface layer of the photoreceptor, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method and the like are employed. In particular, the spray coating method and the ring coating method are suitable because they are easy to ensure quality stability in production.

  The charge transport layer B105 is formed to a thickness of about 3 to 10 μm. The total thickness of the charge transport layer including the charge transport layer A104 and the charge transport layer B105 is preferably 15 to 50 μm, and preferably 15 to 35 μm. At the time of image formation, the photosensitive member is charged at approximately −400 to −800 V. However, as the photosensitive layer becomes thicker, the electrostatic capacity decreases, so that there is a margin for the charged potential. However, as the charge potential is lowered, the movement of charges is delayed, so that holes or electrons are accumulated in the photosensitive layer, and the photosensitive member does not function sufficiently. Therefore, it is not preferable to increase the film thickness more than necessary, and even if the film thickness is increased, it is preferably set to a film thickness corresponding to the charging potential to be used. Usually, it is preferably used at a thickness of 35 μm or less, and even when it is thinned, it is preferably used at a thickness of about 15 μm.

The 10-point average roughness Rz _JIS (JIS B 0601) at the initial stage of the surface roughness of the photoreceptor on which the charge transport layer B105 is formed is preferably 0.1 μm or more and 1.0 μm or less. . This is to obtain a sharp image quality regardless of the roughness of the surface of the photoconductor. This is a condition that when the cleaning blade comes into contact with the photoconductor, the blade edge is distorted and does not cause poor cleaning. is there. As the surface roughness of the photoreceptor decreases, the adhesion of the cleaning blade improves, which is effective for toner cleaning. However, the organic photoreceptor increases the frictional resistance, so that the stick-slip phenomenon or the local area of the blade is increased. In the case of an organic photoconductor, it is not preferable that the size is too small. Further, when the surface roughness is increased, the frictional resistance tends to be relaxed, but the image quality and cleaning properties are affected.

  In recent years, with the demand for higher image quality, polymerized toners with an average circularity of 0.96 or 0.98, which are almost spherical, and around 6 μm are used, but this toner has no sharpness and is nearly spherical. Even if there is a gap smaller than the toner diameter between the cleaning blade and the photosensitive member, it will sink while rotating, so that cleaning failure is likely to occur. Therefore, when using spherical toner, it is important that the cleaning blade is in close contact with the photoreceptor so that no gap is formed, and it is not preferable to have a surface roughness that allows toner to enter. For use over a long period of time, it is desirable that the initial surface roughness of the photoreceptor be kept as smooth as possible. This spherical toner has a tendency to further reduce the particle diameter, and the tendency of the cleaning property to be influenced by the surface roughness of the photoreceptor is becoming stronger.

  Further, when the organic photoreceptor is used, the surface roughness gradually increases due to the rubbing of the cleaning blade, the carrier of the developer, paper dust (such as talc), and the like. Therefore, it is desirable to keep the initial value of the surface roughness of the photoreceptor at a small level. For example, when 50,000 images are formed, the average roughness of the photoreceptor surface is about 1.2 to 2 (μm). However, if there is no defect on the edge of the cleaning blade, the cleaning performance is sufficiently maintained. The When the surface of the photoreceptor becomes rough, the cleaning blade is also affected. Therefore, it is possible to maintain stable image quality over a long period of time by keeping the surface roughness of the photoreceptor low. However, this is a case where the photoconductor is not damaged by the carrier or the like adhering to the surface of the photoconductor. In the conventional image forming apparatus, even if the photoconductor is made highly durable, if the carrier is pressed by the blade, the photoconductor is surely scratched or dented. In addition, since a highly durable photoconductor is difficult to wear, once it is damaged, the scratch will not be repaired (a photoconductor that is easily worn will reduce the depth of the flaw, so the effect on image quality will be affected forever) There is an adverse effect of continuing to occur. That is, in order to maintain high image quality, it is important to prevent the surface of the photoreceptor from being scratched. When the outermost surface layer of the photoconductor is made highly wear-resistant as in the image forming apparatus of this example, it is difficult to wear the photosensitive layer, which is advantageous for maintaining durability. If scratches such as scratches enter the surface of the photoreceptor, scratch repair (due to wear of the photosensitive layer) is not performed, so abnormal images due to scratches are expressed on the copy for a long time, and cleaning defects are likely to occur. Problems arise.

  On the other hand, in the image forming apparatus of this example, it is possible to effectively prevent the surface of the photoreceptor from being damaged by providing the scraping roller 14 as described above.

  Next, the cleaning blade 12 will be described. The member that can be used as the cleaning blade 12 is preferably an elastic member that exhibits uniform adhesion to the photosensitive member and has little mechanical and chemical degradation. An elastic member suitable as a material is polyurethane (or urethane) rubber, and the basic configuration of the cleaning blade 12 is as shown in FIG.

  The urethane rubber for the cleaning blade 12 is obtained by cutting a plate-like rubber having a thickness of 1.5 to 3 mm into a width and a length to be used. By using a thin blade of 1.5 to 3 (mm), the effectiveness of a reinforcing member to be described later is enhanced, and the line contact of the blade edge is better maintained with the reinforcing member attached, and toner cleaning is performed. This is effective in suppressing the penetration of carrier and spherical toner. When the thickness is less than 1.5 mm, there are problems in cleaning properties and durability. When the thickness is 3 mm or more, the blade edge is crushed and the toner and the carrier are submerged under the blade.

  In order to clean the residual powder such as toner, it is necessary to make the surface roughness of the edge of the cut surface as small as possible so that there is no gap between the cleaning blade 12 and the surface of the photoreceptor 1. There is. Usually, the surface roughness of the edge part is often set to 10 μm or less, but even if it is set to 20 μm, there is also an effect of a reinforcing member, it has a sufficient function, and edge loss due to foreign matters such as a carrier is also possible. Since there are few, cleaning can be performed satisfactorily. However, if the surface roughness of the edge is too small, the frictional resistance with the photosensitive member is increased and the possibility of causing the photosensitive member 1 to be locked by the cleaning blade is increased. Although it is necessary, since it is difficult to escape the lock even in this state, it is desirable to perform means for reducing the coefficient of friction of the surface of the photoreceptor as described later.

  The proximal end side of the cleaning blade 12 is attached to a holder 18, and reinforcing members 19 are attached to both surfaces of the cleaning blade 12 having a free length (usually 3 to 10 mm). As shown in FIG. 8, the proximal end side of the cleaning blade 12 is fixed to a support 20 constituted by a part of the cleaning case 13 via a holder 18. Both sides of the cleaning blade 12 are used, and this makes it possible to maintain twice the durability with a single cleaning blade. The free length refers to the length of the blade itself in a free state that cannot be supported by the support 20.

  The cleaning blade 12 is provided with a positioning projection (not shown) and a screw hole in the support body 20 so that the mounting position is always the same, and the positioning hole 21 shown in FIG. These are combined and fixed to the support 20 by a set screw 22.

  The cleaning blade is manufactured, for example, by a strip 18 in which adhesive is applied to both sides in a holder 18 (a metal such as iron or aluminum processed into a U-shape) that opens to about 1 to 2 mm on both sides. A blade 12 made of polyurethane rubber having a width of 1.5 to 3 mm and a JIS-A hardness of 58 ° to 80 ° cut into a shape is inserted and pressed so as to close the mouth of the holder 18. As the adhesive, a commercially available one-component or two-component adhesive, double-sided tape, or the like can be used. The length is long enough to cover the development area.

  The thickness of the blade 12 is 1.5 to 3 mm, but normally a blade cut to a thickness of about 2 to 2.5 mm is preferably used. If it is 1.5 mm or less, it is difficult to maintain durability and cleaning properties. On the other hand, even if it is 3 mm or more, there is no big problem, but in a small image forming apparatus or the like, there is not enough space, and even if it is 3 mm or more, it does not make much sense.

  With respect to the JIS-A hardness of the cleaning blade 12, a higher hardness allows the toner to be in close contact with the photoreceptor, but lacks flexibility, so that the edge of the cleaning blade and the photoreceptor 1 are equivalent to the toner. If there is a slightly larger scratch, there is a concern that the scratch cannot be sufficiently closed and a cleaning failure may occur. The initial JIS-A hardness can be up to about 90 °, but considering the long-term stability, it is sufficient to have about 80 ° when a reinforcing member to be described later is pasted, and the lower limit is up to about 58 °. Is available. Normally, if we consider that a blade with a JIS-A hardness of around 70 ° is used, the range of application will be expanded, but depending on the thickness of the blade, a blade with a thickness of 2 mm can be stably When using, it is preferable to use the thing of the hardness between 65 degrees-75 degrees. Below 58 °, the edge cannot be maintained even if a material with high hardness is used for the reinforcing seal, so that the cleaning performance becomes impossible. Above 80 °, the load on the photoconductor becomes too large and damages the photoconductor such as scratches. .

  Reinforcing members 19 are attached to both sides of the cleaning blade 12 corresponding to its free length in the longitudinal direction, so that the cleaning blade 12 is less lifted from the photosensitive member due to the distortion of the blade 12. The position to be applied is from 1 to 2 mm above the edge of the blade 12 and substantially to the end of the holder 18 and is applied to both sides over the entire length of the free length. The reason for pasting on both sides is that the cleaning blade can be reversed and used. If it can be used in an inverted manner, the cleaning blade 12 can have twice the durability, which is advantageous for resource saving. As described above, the cleaning member of the image forming apparatus of the present example includes the cleaning blade 12 pressed against the surface of the photosensitive member, and the reinforcing members 19 are attached to both surfaces of the cleaning blade 12.

  As the member for attaching the reinforcing member 19 to the cleaning blade 12, any of a strong double-sided tape, a hot-melt adhesive, a one-component or two-component adhesive can be used. However, it is not preferable that the coating generates heat or the adhesive layer is bulky. Usually, a double-sided tape (eg, ST-416P, 4595MP, etc., 3M) having a small adhesive change and having a strong adhesive force can be preferably used. A metal or resin film can be used as the reinforcing member, and a resin film is preferable. The thickness is 25 μm to 300 μm, preferably 50 to 250 μm. As the resin film, a hard material such as a polyethylene terephthalate (PET) film, a polycarbonate film, or a polyimide film can be suitably used. When pasting using an adhesive, it is desirable to select the thickness of the reinforcing seal in consideration of the strength of the adhesive.

  The state where the cleaning blade 12 is attached to the support 20 and is in contact with the photoreceptor 1 is as shown in FIG. 8, and the cleaning blade 12 is pressed against the surface of the photoreceptor in the counter direction. FIG. 9 shows the state of the edge portion of the cleaning blade 12 when the photosensitive member 1 is rotated. The difference between the case where the reinforcing member 19 is pasted and the case where the reinforcing member 19 is not pasted appears in the way the blade 12 bends. In the case where the reinforcing member is not pasted, the edge portion is pulled by the photosensitive member in addition to the overall bending. The contact area of 12 is enlarged. When the reinforcing member 19 is pasted, the entire “bending” is suppressed, the “pulling” of the edge portion is suppressed, the contact area with the surface of the photoconductor is reduced, and it is close to the line contact but relatively good Maintained. That is, since the surface contact is suppressed, the frictional resistance between the cleaning blade 12 and the photosensitive member 1 is reduced, and the cleaning blade 12 is less likely to vibrate and stick-slip. Therefore, there is less room for toner to enter, cleaning defects are improved, and even if there are leaked carriers or paper dust, the blocking rate is increased, and it is possible to reduce damage to the photoreceptor. Become. Further, since the contact pressure of the cleaning blade can be reduced, the hazard to the photosensitive member is reduced, and the durability of not only the photosensitive member but also the cleaning blade can be extended.

  By sticking the reinforcing member 19 to the cleaning blade 12 as described above, the cleaning blade 12 is strengthened, local distortion and stick-slip phenomenon are suppressed, and the adhesion of the edge portion of the blade 12 to the photoreceptor is improved. Get higher. As a result, the toner cleaning property is enhanced and cleaning defects are less likely to occur. Further, the entry of hard foreign matters such as a carrier can be suppressed, and it is possible to suppress the problem that the photoconductor is scratched and the blade edge is damaged.

  The contact pressure of the cleaning blade 12 with respect to the surface of the photosensitive member is set to about 25 g / cm when pulverized toner is used, and between 30 g / cm to 50 g / cm when polymerized toner having a high degree of circularity is used. In this case, the cleaning blade and the state of the photosensitive member have a great influence on the cleaning performance, so it is often not determined only by the contact pressure, but when a reinforcing member is used together with the cleaning blade, the blade As when the hardness is increased, the contact surface with the photosensitive member is strengthened, and the adhesion is improved. If an appropriate reinforcing member is used, the blade may be damaged and the edge of the blade will not be affected by the reinforcing member. Therefore, the cleaning performance can be improved without increasing the contact pressure. become able to do. The reduction of the contact pressure is an effective means for maintaining durability or improving durability in order to lighten the burden on not only the photoconductor but also the edge portion of the cleaning blade 12.

  The contact pressure with respect to the photosensitive member depends on the thickness of the blade 12, but 15 to 30 g / cm is a preferable range, and is set higher when the blade 12 is thick and lower when the blade 12 is thin. desirable. The contact pressure when a blade having a thickness of 2 mm is used is preferably about 20 to 25 g / cm.

  As described above, the cleaning blade 12 has a JIS A hardness of 58 ° to 80 ° and is pressed against the surface of the photoreceptor in the counter direction with a contact pressure of 15 to 30 g / cm. . Accordingly, even when the reinforcing member 19 is attached to the cleaning blade 12, damage to the photoreceptor 1 can be suppressed to a low level and toner cleaning performance can be improved.

  Moreover, the cleaning blade 12 is made of a strip-shaped rubber having a thickness of 1.5 to 3 mm. By using a thin cleaning blade 12 having a thickness of 3 mm, the reinforcing member 19 is used. In addition, the load on the photoconductor is kept low, and the contact area of the blade deformed by pressing with the photoconductor is small, resulting in line contact. As a result, the toner can be satisfactorily cleaned, and toner and carrier do not sink under the cleaning blade, so that both the photoreceptor and the cleaning blade can maintain durability.

  Further, the cleaning blade 12 is used in a state in which one edge portion on the front end side thereof is in pressure contact with the surface of the photoconductor, and the other edge portion on the front end side of the cleaning blade 12 is in pressure contact with the surface of the photoconductor. The base end side opposite to the front end side of the cleaning blade 12 is attached to the holder 18. In this way, the cleaning blade is attached to the holder and can be reversed (use on both sides), so it is advantageous for maintenance and can be doubled with a single cleaning blade. It is effective for resource saving. When the cleaning blade 12 is reversed and reused, no problem will occur if the edge portion of the cleaning blade 12 is sufficiently wiped off.

  Next, the coefficient of friction of the photoconductor shows a relatively low value of about 0.3 to 0.5 when measured by the Euler belt method in the initial state in which there is no scratch, but the photoconductor can be used by using it. Since the oil added as a leveling agent is removed, it gradually rises and shows a high value of 0.6 or more. The coefficient of friction is an important item in image formation, and there is a problem whether it is too high or too low. When the friction coefficient is high (0.5 or more), problems arise in cleaning properties, transfer, etc., and wear of the photoreceptor increases. On the other hand, when it is low (for example, 0.1 to 0.2), problems such as a decrease in toner developability, a decrease in cleaning performance, and an image flow occur. Therefore, it is necessary to take measures to achieve a well-balanced friction coefficient in terms of image quality, durability, cleaning properties, and the like. In the initial state after production of the photoconductor, the coefficient of friction of the photoconductor is a numerical value of about 0.3 to 0.5. However, even if the numerical value is shown during image formation, no particular problem is caused. However, since the cleaning blade is not contaminated with toner when it is initially or after being mounted on an image forming apparatus after maintenance such as part replacement, the frictional resistance between the photosensitive member and the cleaning blade is extremely large. Therefore, even if a driving force is applied to the photosensitive member, it cannot be rotated, and the gear or the like may be damaged. As a means for avoiding this state, it is possible to significantly reduce the coefficient of friction on the surface of the photoreceptor. The most effective means is to apply a lubricant to the photoreceptor that can effectively reduce the coefficient of friction with a small supply amount.

  For example, polytetrafluoroethylene (PTFE) is an excellent lubricant, and powdered PTFE (eg, Daikin Industries, Lubron L-2.L-5, etc.) is applied to cotton cloth or non-woven fabric to scratch the photoreceptor. It is possible to achieve this by applying it while rubbing to the extent that it does not stick, and forming a thin layer of lubricant as a whole (it is not necessary to apply uniformly). In addition to PTFE, there are fluorine resin powders (for example, polyvinylidene fluoride). However, the effect is considerably reduced, and the effect is merely the effect of rotating the photoconductor. There are also cases where a rubbing sound is produced or the smooth rotation is not possible. By forming a thin film of PTFE on the photoreceptor, the friction coefficient can be reduced to a low value of around 0.25. Since the coefficient of friction after coating is maintained for a long time unless it is used, this process may be performed immediately after the production of the photoreceptor. When the coefficient of friction is about 0.25 or less, the photoreceptor can be easily rotated. Therefore, even a highly durable photoreceptor can be rotated without scratching. Even if the coefficient of friction drops to 0.2 or less in the initial stage, if an image is formed, the lubricant is removed by a cleaning blade or the like, and the coefficient of friction increases. Even if a value of about 0.2 is maintained, the initial value is maintained. In this case, the image quality is not affected at all. If the rotation of the photosensitive member becomes easy, the toner can be supplied later for development, so that the photosensitive member can be rotated smoothly. However, if there is no supply of lubricant or an alternative material that smoothes the surface, the coefficient of friction will gradually increase to 0.5-0.6, resulting in problems such as cleaning performance, image quality, and photoreceptor durability. Will arise.

  Therefore, a means for applying a lubricant to the surface of the photoreceptor is necessary. However, as a means for reducing the friction coefficient (preferably about 0.25 to 0.35), the friction coefficient of the photoreceptor in the toner is used. There are a method of adding a wax having an effect of lowering, adding the above-mentioned fluororesin particles to the toner, or attaching a lubricant coating device and supplying it to the surface of the photoreceptor. As a means for reducing the friction coefficient, there is also a means for adding about 30 to 60% by weight of fluororesin particles to the surface of the photoreceptor.

  As the toner, low melting point toner is becoming the mainstream for power saving and avoiding environmental pollution. From the standpoint of improving the image quality, not only the cleaning property but also the transfer property and the releasing property at the time of fixing must be good. As an improvement measure, a wax is contained in the vicinity of the toner surface. The wax is contained in an amount of about 5 to 10% by weight with respect to the toner. By selectively containing the wax in the vicinity of the surface of the toner, the wax acts on the photoconductor to lower the friction coefficient of the photoconductor. In this case, the reduction of the friction coefficient proceeds slowly. In the initial stage, the effect of the lubricant pre-applied to the photoconductor is effective, and in the long term, the friction coefficient is reduced to a level of about 0.3 due to the effect of reducing the surface free energy of the photoconductor and the effect of wax in the toner. It can be changed. However, although the amount of toner used may vary depending on the image area of the document, and the friction coefficient may become unstable due to the formation of filming, the coefficient of friction should be changed by about 0.3 to 0.35 on average. Is possible. If the foreign matter adhering to the photosensitive member is removed, the friction coefficient can be lowered to 0.3 or less. However, when wax is used, the effect of adding the fluororesin particles may not function sufficiently.

The coefficient of friction is measured by the following measuring means.
Measurement of coefficient of friction of photoconductor A photoconductor for measurement was fixed to a pedestal, and a fine paper of 85 μm in thickness (made by Ricoh, type 6200 paper, using vertical eyes) cut to a width of 30 mm and a length of 290 mm was used as a belt. Place the fine paper on the photoconductor, attach a weight of 100gr to one end of the belt, attach a digital force gauge for weight measurement to the other end, pull the digital force gauge slowly, Is read, and the (static) friction coefficient μs is calculated from equation (1).
μs = 2 / π × ln (F / W)
Where μs: static friction coefficient, F: reading load
W: Weight of weight π: Circumference ratio

  As described above, by applying a powdery lubricant to the surface of the photoconductor or adding a lubricant to the outermost layer of the photoconductor, problems due to excessively high friction coefficient on the surface of the photoconductor are prevented. it can.

  Further, by inserting a vibration damping material into the photosensitive member 1, it is possible to suppress vibration generated on the photosensitive member when a DC voltage in which an alternating voltage is superimposed is applied to the charging device 2.

  In addition, the toner used for the developer of the image forming apparatus is roughly classified into a pulverized toner having irregular shapes that are mainly mechanically manufactured, and a rounded, almost spherical shape manufactured by a polymerization method. Or there is a spherical toner close to a true sphere. Since the characteristics of the pulverized toner are irregular, when the blade cleaning method is used, the toner is less likely to slip and rotate on the photosensitive member, so that the cleaning performance is relatively good. The particle size distribution is wide (± 4 to 5 μm) even if it is classified, so that it has a defect that a minute particle size is included.

  On the other hand, a toner produced by a polymerization method has a narrow particle size distribution because it is chemically produced, usually ± 1 to 2 μm. However, if the production conditions are adjusted, a toner having an extremely narrow particle size distribution of ± 0.5 μm It is also possible to produce. As a result, since the distribution of the charge amount of one toner is reduced, the development is faithful to the electrostatic latent image, and high image quality with good sharpness can be obtained. However, since it has a spherical shape, there is a drawback that cleaning properties are likely to be difficult.

  In the image forming apparatus of this example, either a pulverized toner or a polymerized toner can be used. However, if the toner cleaning function can be sufficiently exerted, a substantially spherical toner (polymerized polymer) is extremely effective. It is preferable to use a toner. The term “substantially spherical” is used because the true sphere is more difficult to clean, and is used here to mean a shape that is not a true sphere.

  The smaller the particle size of the toner used in the developer, the easier it is to obtain an image with higher resolution. However, since the amount of charge held by one toner increases, the dot pattern and fine lines formed on the surface of the photoreceptor are increased. It is difficult to faithfully develop an electrostatic latent image such as, and the edges of characters and the like tend to be jagged. Also, transfer defects are likely to occur. Further, the toner may be buried in the scratches generated on the surface of the photosensitive member and the cleaning blade, or may pass through a minute gap between the cleaning blade and the photosensitive member, resulting in a cleaning failure. Therefore, it is desirable that the average particle diameter of the toner actually used for image formation is 3 μm or more, and preferably 4 μm or more.

  On the other hand, as the toner diameter increases, the amount of charge held by one toner decreases, so the amount of toner adhering to the photoreceptor increases, and the image contrast increases, but the image does not protrude from the electrostatic latent image. Therefore, the image quality is lacking in fineness, softness, and resolution. Also, transfer defects are likely to occur.

  Generally, the average particle size used for image formation is 10 μm or less, but it is preferable to use a toner of 8 μm or less. That is, in order to obtain high image quality, the average particle size of the toner used for the developer is 4 μm or more and 8 μm or less.

  Examples of the method for producing the polymerized toner include suspension polymerization, dispersion polymerization, emulsion polymerization, microcapsule polymerization, and spray drying. For example, in the case of suspension polymerization, the binder resin is produced by homogenizing an additive such as a colorant or a charge control agent, and adding a dispersion medium and a dispersant to polymerize the binder resin. Since the process of the polymerization method is simplified, the manufacturing cost is lower than that of the pulverization method. In addition, there is an advantage that the particle diameters are relatively well aligned, toners having large and small particle diameters can be selectively produced, and irregularly shaped particles are hardly produced (mostly spherical toners). Particles produced by the polymerization method have no angularity, and a spherical shape (circularity of 1.0 is true sphere) is obtained, but depending on the production conditions, a shape with protrusions, a pine nut shape, or a spindle shape, It is also possible to obtain a bowl shape or the like. Since the particle size distribution of the toner obtained by the polymerization method is narrower than that of the toner produced by the pulverization method, the charged charges are easily arranged almost uniformly and adhere to the latent image almost faithfully. Therefore, the transfer efficiency is good, high resolution is easily obtained, and image reproducibility tends to be high.

  In the polymerization method, those having an average circularity of 0.95 or less and those having 1.0 or more can be produced depending on the production conditions. The closer the average circularity is to 1.0, the closer to the true sphere, but the easier it is to clean the better as it becomes a true sphere. On the other hand, the smaller the average circularity (for example, 0.93) or 1.0 or more, the easier it is to clean, but the fidelity to the electrostatic latent image tends to decrease slightly. As the average circularity approaches 1.0, the sphere becomes a true sphere, which causes a problem in cleaning performance. Therefore, the average circularity of the toner used for image formation is desirably 0.95 to 0.99, and 0.96 to 0.98 is particularly preferable in order to achieve both high image quality and cleanability.

  As described above, as a developer toner for visualizing an electrostatic latent image, a toner produced by a polymerization method and having an average circularity of 0.95 to 0.99 and an average particle diameter of 4 to 8 μm is used. It is particularly desirable to do so.

  The toner for electrophotography is produced by mainly including a binder resin, a colorant, and a charge control agent, and further adding a release agent. Examples of general binder resins, colorants, charge control agents, release agents, and external additives used for toner production are shown below.

(1) Binder resin Styrene, ethylene, propylene, butylene, vinyl acetate, vinyl benzoate, methyl acrylate, ethyl acrylate, octyl acrylate, dodecyl acrylate, phenyl acrylate, ethyl methacrylate, methyl methacrylate, methacryl Polymers or copolymers of acid butyl, vinyl methyl ether, vinyl butyl ether, vinyl methyl ketone, vinyl isopropenyl ketone, vinyl hexyl ketone, vinyl propionate, isobutylene, chlorostyrene, polystyrene, polyethylene, polyester, styrene-acrylonitrile copolymer Such as polymer, styrene-alkyl methacrylate copolymer, styrene-butadiene copolymer, polypropylene, styrene-maleic anhydride, polyurethane, epoxy resin, modified rosin, etc. Material can be used for.

(2) Colorant Carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthra Zan Yellow BGL, Isoindolinone Yellow, Bengala, Red Plum, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Red 4R, Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Po Gmento Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thio Indigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzy Orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, BC), Indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B , Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium, zinc white, lithopone and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight in the toner.

(3) Release agent The toner of the present invention may contain a release agent (wax) together with a toner binder and a colorant, if necessary. As the mold release agent, known materials such as aliphatic hydrocarbons, aliphatic metal salts, fatty acid esters, silicone oil, and various waxes can be used. Examples of such materials include polyolefin waxes (polyethylene wax, polypropylene wax, etc.); long chain hydrocarbons (paraffin wax, sazol wax, etc.); carbonyl group-containing waxes, and the like. Of these, carbonyl group-containing waxes are preferred. Carbonyl group-containing waxes include polyalkanoic acid esters (carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18 -Octadecanediol distearate, etc.); polyalkanol esters (trimellitic acid tristearyl, distearyl maleate, etc.); polyalkanoic acid amides (ethylenediamine dibehenylamide, etc.); polyalkylamides (trimellitic acid tristearylamide, etc.) And dialkyl ketones (such as distearyl ketone). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred. The melting point of the wax is usually 40 to 160 ° C, preferably 50 to 120 ° C, more preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat resistant storage stability, and a wax having a melting point of more than 160 ° C. tends to cause a cold offset when fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps, more preferably 10 to 100 cps as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps have poor effects for improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 0 to 40% by weight, preferably 3 to 30% by weight.

(4) Charge Control Agent The toner of the present invention can contain a charge control agent as required. Various known charge control agents can be used. Examples include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified quaternary ammonium salts). ), Alkylamide, phosphorus simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit), copper phthalocyanine, perylene, quinacridone Azo pigments, sulfonate group, a carboxyl group, such as polymer compounds having a functional group such as quaternary ammonium salts.

  The amount of the charge control agent used is determined by the toner production method including the type of binder resin, the presence or absence of additives used as necessary, and the dispersion method, but is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, the electrostatic attractive force with the developing roller is increased, the flowability of the developer is reduced, and the image density is reduced. Incurs a decline. These charge control agents and mold release agents can be melt-kneaded together with the masterbatch and resin, and of course, they may be added when dissolved and dispersed in an organic solvent.

(5) External additive As the external additive for assisting the fluidity, developability and chargeability of the colorant-containing toner particles, inorganic fine particles can be preferably used. The primary particle diameter of the inorganic fine particles is preferably 5 μm to 2 μm, and particularly preferably 5 μm to 500 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight. Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. In addition, polymer-based fine particles can be used. Examples of such materials include polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, and thermosetting resins. Examples include polymer particles. Such an external additive can be surface-treated to increase hydrophobicity and prevent deterioration of its flow characteristics and charging characteristics even under high humidity. Preferred examples of the surface treatment agent include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. Can be mentioned.

  In addition, as a cleaning property improver for removing the developer after transfer remaining on the photoreceptor and the primary transfer medium, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, for example, polymethyl methacrylate fine particles, Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 μm to 1 μm.

The average circularity of the toner described in the present invention is measured, for example, by the following method.
Average circularity = Σ (peripheral length of circle having the same projected area as the particle image / perimeter length of the projected particle image) / number of measured particles Assuming that the number of measured particles is 1000 particles or more, the calculation should be performed with a particle diameter of 5 μm or more. Select and project the toner image to calculate the perimeter. As a measuring apparatus, there is FPIA-1000 type manufactured by Sysmex Corporation.

  In the image forming apparatus shown in FIG. 1, the photosensitive member 1, the charging device 2, the developing device 4, the cleaning device 11, and the like are detachably attached to the main body of the image forming device. When the process cartridge is configured by integrally assembling with the take-up roller 14 and the process cartridge is detachably attached to the main body of the image forming apparatus, when the device or the component constituting the process cartridge fails, By simply replacing the process cartridge, the image forming operation can be restarted at an early stage, and the maintenance of the image forming apparatus can be simplified.

  FIG. 10 shows a process cartridge 23 in which the photosensitive member 1, the charging device 2, and the cleaning device 11 to which the scraping roller 14 is assembled are integrated.

  Further, the image forming apparatus shown in FIG. 1 is configured to transfer the toner image formed on the photosensitive member 1 to a transfer material made of a recording medium, but like the image forming apparatus shown in FIG. Each of the above-described configurations can also be applied to an image forming apparatus configured to transfer a toner image formed on a photoconductor onto a transfer material made of an intermediate transfer body. The image forming apparatus shown in FIG. 11 has a plurality of photoconductors 1M, 1C, 1Y, and 1BK. Similarly to the case of the image forming apparatus shown in FIG. A toner image, a yellow toner image, and a black toner image are formed. These photoreceptors are provided with intermediate transfer members 27 formed of endless belts that are wound around a plurality of support rollers 24, 25, and 26 and rotated in the direction of arrow X. The toner images of the respective colors formed on 1M, 1C, 1Y, and 1BK are transferred in an overlapping manner. The superimposed toner image is transferred to the recording medium P fed from the paper feeding device 7 by the action of the secondary transfer device 28, and when the recording medium P passes through the fixing device 10, the toner image on the recording medium P is transferred. Is fixed to the recording medium P.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to these Examples.

Preparation Example 1 of Evaluation Photoconductor
Apply an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution to the following composition on a φ30 mm x 340 mm aluminum drum (JIS standard 3003 series), and heat-dry. Thus, an undercoat layer of 3.5 μm, a charge generation layer of 0.3 μm, a charge transport layer of 22 μm and 28 μm were formed. The heat drying conditions are 120 ° C. for 20 minutes for the undercoat layer, and 130 ° C. for 20 minutes for the charge generation layer and the charge transport layer.
[Coating liquid for undercoat layer]
Alkyd resin (Beccosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals) 10 parts by weight Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals) 7 parts by weight Titanium oxide (CR-EL Ishihara Sangyo) 40 parts by weight Methyl ethyl ketone 200 parts by weight [Coating liquid for charge generation layer]
5 parts by weight of bisazo pigment having the following structure (manufactured by Ricoh)

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ社製） １重量部
シクロヘキサノン ２００重量部
メチルエチルケトン ８０重量部
〔電荷輸送層Ａ用塗工液〕
ポリカーボネート樹脂（Ｚポリカ、粘度平均分子量；５万、帝人化成社製）
１０重量部
下記構造の低分子電荷輸送物質 ７重量部

Polyvinyl butyral (XYHL, manufactured by UCC) 1 part by weight Cyclohexanone 200 parts by weight Methyl ethyl ketone 80 parts by weight [Coating liquid for charge transport layer A]
Polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.)
10 parts by weight 7 parts by weight of low molecular charge transport material having the following structure

テトラヒドロフラン １００重量部
１％シリコーンオイル（ＫＦ５０−１００ＣＳ信越化学工業社製）テトラヒドロフラン溶液 １重量部

Tetrahydrofuran 100 parts by weight 1% silicone oil (KF50-100CS manufactured by Shin-Etsu Chemical Co., Ltd.) Tetrahydrofuran solution 1 part by weight

Next, spray coating was performed using the coating liquid for the charge transport layer B described below, and a target charge transport layer B was laminated by heat drying at 170 ° C. for 20 minutes to prepare a photoconductor for evaluation.
[Coating solution for fluorine resin-containing charge transport layer B]
2 parts by weight of low molecular charge transport material with the following structure

フッ素樹脂粒子（ＭＰＥ−０５６、三井デュポンフロロケミカル社製）
１０重量部
フッ素系界面活性剤（モディパーＦ２００、日本油脂社製）
１０重量部（固形分：３重量部）
メラミン樹脂（スーパーベッカミン Ｇ−８２１−６０，大日本インキ化学工業製） ５重量部
テトラヒドロフラン １８０重量部
シクロヘキサノン ５０重量部

Fluorine resin particles (MPE-056, manufactured by Mitsui DuPont Fluorochemicals)
10 parts by weight Fluorosurfactant (Modiper F200, manufactured by NOF Corporation)
10 parts by weight (solid content: 3 parts by weight)
Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals) 5 parts by weight Tetrahydrofuran 180 parts by weight Cyclohexanone 50 parts by weight

The spray coating conditions for the charge transport layer are as follows.
[Condition for coating the protective layer on the outermost surface of the photoreceptor]
Coating liquid discharge rate: 15 ml / min
Coating liquid discharge pressure: 2.0 kgf / cm ²
Rotating speed of coated drum: 120rpm
Coating speed: 24mm / sec
Distance between spray head and coated drum: 5cm
Number of coatings: 2 times

Preparation Example 2 of Evaluation Photoconductor
An organic photoreceptor used for evaluation was prepared by the following means.
After dip coating with an undercoat layer (UL) coating solution having the following specifications, a JIS standard 3003 series aluminum alloy drum machined to φ100 mm, length 360 mm, and wall thickness 1.2 mm was used as a conductive support. C. for 20 minutes to form an undercoat layer of about 3.5 .mu.m. Next, after dip-coating with a coating solution for a charge generation layer (CGL) using a titanyl phthalocyanine-based charge generation material, it was dried by heating at 120 ° C. for 20 minutes to form a 0.2 μm charge generation layer. Furthermore, after immersing in the coating solution for charge transport layer A (CTL) using the charge transport material described in the formula (4) to coat the charge transport layer A, heat drying at 130 ° C. for 20 minutes is performed. Then, an organic photoreceptor having an average film thickness of the photosensitive layer of about 22 μm and 30 μm was produced. The average film thickness of the photosensitive layer is an average value obtained by measuring 13 points at intervals of 20 mm starting from 50 mm from the end using an eddy current film thickness meter (type mms) manufactured by Fischer.
[Coating liquid for undercoat layer]
Alkyd resin (Beckosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals) 6 parts by weight Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals) 4 parts by weight Titanium oxide (CR-EL 40 parts by weight Methyl ethyl ketone 200 parts by weight [Coating liquid for charge generation layer]
Oxotitanium phthalocyanine pigment (Ricoh) 2 parts by weight Polyvinyl butyral (Union Carbide: XYHL) 0.2 part by weight Tetrahydrofuran (Kanto Chemical Co.) 50 parts by weight [Coating liquid for charge transport layer A]
Bisphenol Z-type polycarbonate (manufactured by Teijin Chemicals Ltd .: Z Polica Mv50,000)
10 parts by weight 8 parts by weight of low molecular charge transport material having the following structure

テトラヒドラフラン ２００重量部
１％シリコーンオイル（ＫＦ５０−１００ＣＳ信越化学製）テトラヒドラフラン溶液 １重量部

Tetrahydrafuran 200 parts by weight 1% silicone oil (KF50-100CS manufactured by Shin-Etsu Chemical) Tetrahydrafuran solution 1 part by weight

Furthermore, using the following coating solution for charge transport layer B, spray coating is performed, and heat drying is performed at 170 ° C. for 20 minutes to form a charge transport layer B of 5 μm, and evaluation photosensitivity with enhanced durability. The body was made.
[Coating liquid for charge transport layer B]
2 parts by weight of low molecular charge transport material having the following structural formula

フッ素樹脂粒子（ＭＰＥ−０５６、三井デュポンフロロケミカル社製）
１１重量部
フッ素系界面活性剤（モディパーＦ２００、日本油脂社製）（固形分：４．２重量部） １４重量部
メラミン樹脂（スーパーベッカミン Ｇ−８２１−６０，大日本インキ化学工業製） ５重量部
テトラヒドロフラン １８０重量部
シクロヘキサノン ５０重量部

Fluorine resin particles (MPE-056, manufactured by Mitsui DuPont Fluorochemicals)
11 parts by weight Fluorosurfactant (Modiper F200, manufactured by NOF Corporation) (solid content: 4.2 parts by weight) 14 parts by weight Melamine resin (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.) 5 Parts by weight tetrahydrofuran 180 parts by weight cyclohexanone 50 parts by weight

[Production example of cleaning blade]
[Production Example 1 of Cleaning Blade]
326 × 17 × 1.6 (mm) steel plate and L-shaped iron plate of the same size (inner dimension processed to L-shape is 1.95 mm) Screw hole for 3 mm screw at 9 mm from bottom After opening the tape, attach it to one side of polyurethane rubber cut to 326 x 11.5 x 1.96 (mm) using an instantaneous adhesive so that the free length of the blade is 7.5 mm, Similarly, an instantaneous adhesive was applied to the opposite surface and an L-shaped iron plate was placed thereon to produce a holder-shaped cleaning blade. Here, an example of 7.5 mm is given as an example of the free length, but in the case of a fixed cleaning blade, the contact pressure against the photosensitive member can be changed by changing the free length. Usually, it may be performed by shifting by 0.1 to 0.2 mm and changing the bonding position of the blade. Although an instant adhesive was used as an adhesive for the convenience of experiments, a hot melt adhesive or other one-component or two-component adhesive may be used instead of the instantaneous adhesive. The same applies to [Production Example 2 of cleaning blade].

  Next, leave 1 mm from the edge on the free length surface of the blade, and use a strong double-sided tape (3M Company 4595MP) to make the film thickness 326 × (9.5 to 10.5) (mm) with 166 μm. The cut PET film was laminated to complete the cleaning blade. A cleaning blade manufactured by these methods is referred to as a cleaning blade A.

[Production Example 2 of Cleaning Blade]
326 × 17 × 1.6 (mm) iron plate and 326 × 17 × 1.6 (mm) L-shaped iron plate processed into L-shape so that the inner bending dimension is 2.0 mm After making a screw hole for a 3 mm screw at a position of 9.5 mm from the lower end, the blade has a free length of 9.5 mm (the contact pressure is 0.1 to 0 A fine adjustment by changing by 2 mm) and pasted on one side of polyurethane rubber cut to 326 x 14.5 x 2.0 (mm) using instant adhesive, and the other side Similarly, an instantaneous adhesive was applied to the surface of the plate and an L-shaped iron plate was placed thereon to produce a holder-shaped cleaning blade.

  On the other hand, the cleaning blade is fixed with a screw to an L-shaped metal fitting having a length of 326 mm and bent to a width of 19.4 mm on one side and 12.5 mm on the other side. A cleaning blade having a length from the tip of the metal fitting to the blade free length of 22 mm was produced.

  Next, leave 1 mm from the edge on the free length surface of the blade, and use a strong double-sided tape (3M Company 4595MP) to cut a PET film (Toray Industries) with a film thickness of 105 μm to 326 × 10.5 (mm). The cleaning blade was completed. A cleaning blade manufactured by these methods is referred to as a cleaning blade B. The above-described cleaning blade has a positioning hole, and a projection corresponding to the positioning hole is formed on the side where the cleaning blade is attached.

[Example of scraping roller production]
[Scraping roller production example-1]
Obtain a member in which a stainless steel core bar with a diameter of 8 mm is formed with slits with a width of 0.5 mm, a length of 328 mm, and a depth of 1 mm formed at intervals of about 4.1 mm and a vinyl chloride cylinder with a thickness of 2 mm covered. did. To this member, a polyethylene terephthalate film (Toray PET film) cut to a thickness of 110 μm, a width of 3.5 mm, and a length of 327 mm was inserted into the slit of the vinyl chloride cylinder, and cyanoacrylate resin (Aron Alpha, Toagosei Co., Ltd., trade name) ) To complete the scraping roller as shown in FIG. When this scraping roller is attached to an evaluation machine (Imagio 7070, manufactured by Ricoh Co., Ltd.) equipped with a φ100 mm photoconductor, the fin protrudes 2.5 mm from the vinyl chloride cylinder and is almost in contact with the photoconductor (≈0 mm). ) Or slightly non-contact (about 0.1 mm). This scraping roller is called scraping roller A.

[Scraping roller production example-2]
In addition, a member in which a vinyl chloride cylinder having a thickness of 2 mm, on which a slit having a width of 0.5 mm, a length of 328 mm, and a depth of 1 mm is formed at intervals of about 4.1 mm, is formed on a stainless steel core having a diameter of 6 mm. A polyethylene terephthalate film (PET film made by Toray) with a thickness of 52 μm, a width of 2.5 mm, and a length of 327 mm was inserted into a slit of a vinyl chloride cylinder, and an instantaneous adhesive (cyanoacrylate resin, Aron Alpha = Toagosei Co., Ltd.) The product was bonded and fixed with a product name) to prepare a scraping roller as shown in FIG. When this scraping roller is attached to an evaluation machine (Ipsio 8100 machine, manufactured by Ricoh Co., Ltd.) equipped with a φ30 mm photoconductor, if the fin protrudes 1.5 mm from the vinyl chloride cylinder, the photoconductor will bite up to 1 mm. Become. This scraping roller is called scraping roller B.

Example 1
An Imagio MF7070 remodeling machine (manufactured by Ricoh, using a corona charging device) was prepared as an evaluation machine. The evaluation apparatus uses the φ100 mm organic photoconductor described in Preparation Example 2 of the evaluation photoconductor, the cleaning blade described in Preparation Example 2 of the cleaning blade, and the scraping roller described in Preparation Example 1 of the scraping roller. I set it. The distance between the tip of the scraping roller fin and the photoreceptor is -0.1 mm in design. The rotation speed of the scraping roller was 180 rpm. The entire surface of the photoconductor is rubbed with a non-woven fabric (Asahi Kasei Heisegase) containing PTFE powder (Daikin Industries L-2) in advance, and the coefficient of friction is between 0.2 and 0.3. Pretreatment was performed to enter. The contact pressure of the cleaning blade was 22 g / cm. As a toner, a black toner having an average circularity of 0.976 and an average particle size of 5.8 μm (particle size distribution≈1.1 μm) prepared by a suspension polymerization method manufactured by Ricoh Co., Ltd. 10% by weight)), a magnetic material having an average particle size of 55 μm (manufactured by Powdertech) was used for the carrier, and the toner concentration was 6% by weight with respect to the carrier.

  As a test chart used for the evaluation, a Ricoh original A-3 version manuscript (test chart) on which a chart for resolving power evaluation (JIS Z 6008 1982, manufactured by Kodak) was attached was used. The image forming conditions were a charging potential of the photosensitive member of −680 V, an image portion potential of −180 V, and a developing bias of −550 V. As the image samples used for the image evaluation, two A-3 size image samples were prepared using the above-described predetermined A-3 size document (test chart). Subsequently, 25,000 sheets were run using an A-4 size text original with an image area of 6%, and an image sample for evaluation was created again. This process was repeated even after 50,000 sheets, and initial, 25,000 and 50,000 sheet image samples were collected. For the image evaluation, the resolution of the image sample, the background stain, the streaks, the reproducibility of the halftone image (one dot pattern), and the like were evaluated. Further, for the photoconductor, scratches on the surface of the photoconductor were evaluated, and for the cleaning blade, an edge defect state, a carrier adhesion state, and the like were evaluated. For observation of the size of the blade edge defect, an ultradeep shape measuring microscope (VK-8500 manufactured by Keyence Corporation) was used.

  The results are shown in Table 1. However, only the evaluation results after 50,000 sheets are shown in the table. Even when a polymer toner having a high degree of circularity was used, the cleaning property was good and the background dirt could not be visually confirmed. Further, the carrier at the position of the cleaning blade was slightly confirmed, but no carrier was removed. The adhesion of the carrier was also confirmed on the scraping roller, and it was confirmed that the scraping roller had a sufficient effect of removing the carrier. Although the photoconductor was confirmed to have a rubbing scratch on the entire surface, there was no occurrence of scratches on the photoconductor because there was no missing blade of the carrier. For this reason, there was no defect in the blade edge, and the maximum was 34 μm. The photoconductor was clouded but the gloss was maintained. Although not shown in the table, the abrasion of the photosensitive layer is small, and the amount of abrasion at 50,000 sheets averages 0.54 μm (average value of initial point −50,000 in 13 points in the length direction of the photoreceptor as measured by Fisher's mms) The reason why the wear was small in the amount of wear after the sheet was considered to be due to the effect of the wax in the toner and the wear resistance of the photoreceptor (improved hardness and low free surface energy). Incidentally, the friction coefficient on the photosensitive member was 0.34 after 25,000 sheets and 0.29 after 50,000 sheets. The determination is ○, and it is determined that there is no problem in practical use and that the durability and the image quality have sufficient performance.

(note)
1) Uncovered width: refers to the width of the area where there is no covered seal from the edge of the cleaning blade to the reinforcing seal. The length of the reinforcing seal was the same as the length of the cleaning blade.
2) The amount of biting is the distance from the tip of the fin of the scraping roll to the photoreceptor, and (−) minus means that there is a gap.
3) The blade defect depth indicates the maximum value when the contact portion (edge) of the photosensitive member is viewed from the side surface (the surface on which the reinforcing seal is pasted). Observation was confirmed with a magnifying glass 10 to 25 times in advance, and then the largest defect was measured.
4) The scratch state on the photoconductor is “shallow on the entire surface”. A scratch-like streak pattern is observed on the entire surface of the photoconductor, but the streak pattern is a shallow streak formed by the rubbing of the blade. There is no influence on.
5) “Fair” of carrier adhesion refers to the degree to which about 1 to 2 toners can be confirmed by touching the toner accumulated in the contact portion between the blade and the photoreceptor.
6) Judgment ○ means that there is no problem in practical use.

Comparative Example 1
The scraping roller was removed from Example 1, and evaluation was performed in the same manner as Example 1 with the content of using a normal cleaning blade in which no reinforcing seal was attached to the cleaning blade. The results are shown in Table 2. In the comparative example, the same procedure as in Example 1 was started to evaluate 50,000 sheets. However, a good image was reproduced at the time of initial image sample collection. However, when paper running was started in place of the A-4 size document, a cleaning failure occurred from around the fifth to sixth sheets. Evaluation after 10 sheets was stopped and evaluation after 10 sheets was carried out. Therefore, Table 2 shows the results after 10 sheets. It seems that the initial cleaning was performed satisfactorily because surface treatment was performed to reduce the friction coefficient of the photoreceptor. In addition, the cleaning failure started to occur from about 5 to 6 sheets because the friction coefficient increased because the fluororesin layer of the photoconductor was worn and the wax was not sufficiently supplied from the toner (friction coefficient). ≈0.48). Therefore, although there is a rubbing scratch on the photosensitive member, it is not the number of sheets until the scratches are generated, and there is almost no blade defect, but the determination is “x” because of the poor cleaning. In other words, even if the toner has a circularity of about 0.976, the friction coefficient of the photosensitive member increases, and if the contact surface between the cleaning blade and the photosensitive member becomes abnormal, the toner on the blade This means that the omission prevention does not work sufficiently and the toner omission is likely to occur.

(note)
1) The blade defect depth indicates the maximum value when the contact portion (edge) of the photosensitive member is viewed from the side surface (the surface on which the reinforcing seal is applied). Observation was confirmed with a magnifying glass 10 to 25 times in advance, and then the largest defect was measured. Since 22 μm is 10 μm or less at the initial stage, it is a degree that shaving has occurred slightly.
2) “x” in the judgment means that a cleaning failure occurs and there is a problem in practicality.

(Comparative Example 2)
Instead of the durability-enhanced photoconductor used in Example 1, a normal photoconductor (film thickness 28 μm) laminated up to the charge transport layer A was used, and evaluation was performed under the same conditions and methods as in Example 1. The results are shown in Table 3. The photoconductor used for the evaluation had good toner cleaning properties and background stains, and the generation of scratches by the carrier and the carrier adhesion to the blade were almost the same as or slightly greater than those in Example 1. Since the photoconductor used is not subjected to wear resistance, the wear of the photosensitive layer is large, and after the completion of 50,000 sheets, the wear is about 5 times that of the example (average wear amount 2.6 μm). Large wear (maximum 3.7 μm) was also observed, and the durability was insufficient when used in a high-speed image forming apparatus. The friction coefficient was 0.23 at the initial stage, about 0.42 after 25,000 sheets, and 0.39 after 50,000 sheets.

Examples 2-5
The cleaning blade to be mounted on the evaluation machine has three types of blade JIS-A hardness of 60 °, 74 ° and 80 ° according to Cleaning Blade Preparation Example-2, and the blade free length portion not coated with a reinforcing seal is not covered. Cleaning blades having widths of 0.5 mm and 1.0 mm were prepared. On the other hand, for the scraping roll, a scraping roller prepared according to the scraping roller manufacturing example-1 and having a fin (52 μm thick PET) biting amount with respect to the photoreceptor of −0.1 mm and +0.5 mm is prepared. did. These members were evaluated by the same method as in Example 1 while changing every 50,000 sheets. The results are shown in Table 4. The initial characteristics are all at a level where there is no problem, and the evaluation results shown in Table 4 are the results after 50,000 sheets.

  Deep scratches on the photoreceptor due to the carrier did not occur under the conditions of Examples 2 to 5, and there was no effect on the image and toner cleaning. However, a slight amount of carrier passing through the scraping roll was observed on the blade. This comes from the structure of the fins of the scraping roller and is judged to be a functionally satisfactory level.

  When a reinforcing seal is affixed to a rubber blade having a JIS-A hardness of 80 ° (Example 5), the overall elasticity (flexibility) of the blade even when the contact pressure is 22 g / cm. As a result, the wear force of the photoconductor increased (1.2 μm after 50,000 sheets) and the gloss was apt to be slightly lost. As a result, a normal image was obtained after 25,000 sheets, but a portion where the reproducibility of the 1-dot pattern slightly deteriorated (slightly lost shape) was observed after 50,000 sheets. Although it is possible to improve by reducing the thickness of the reinforcing seal film a little, it is judged that the rubber hardness of about 80 ° is close to the limit in the present invention.

  Regarding the other Examples 2 to 4, there is no problem that can be said to be particularly abnormal, the toner is sufficiently suppressed by the blade, the blade edge is missing about 40 μm, and the coefficient of friction of the photosensitive member (0.31 to 0.37). Sufficient deterrent capability is maintained.

Examples 6-7
As an evaluation machine, an Ipsio Color 8100 machine (manufactured by Ricoh Co., Ltd.) using a φ30 mm photoconductor was used. The cleaning blade was produced by the method described in Cleaning Blade Production Example-1. A 166 μm PET film was used for the reinforcing seal attached to the side surface of the blade, and the uncoated width was 1.0 mm or 0.5 mm. The scraping roll was prepared by a method according to the scraping roll preparation example-2. 52 μm PET was used for the fin, and the amount of biting into the photoreceptor was −0.1 mm or +1.0 mm. The number of rotations of the scraping roll was 215 rpm. These were mounted on the photoreceptor unit. The photosensitive member described in Preparation Example 1 of the photosensitive member for evaluation was used as the photosensitive member, the charging condition and the image exposure condition were adjusted, and the charging potential was set to -780 V and the image portion potential was set to -180 V, respectively. For the evaluation, magenta toner (manufactured by adding 10% by weight of a wax having a melting point of 83 ° C. at the time of manufacture) was added to only the magenta station of the developing device. The average circularity and average particle size of the magenta toner were 0.968 and 5.6 μm, respectively. The toner concentration is 7% by weight. Black, cyan, and yellow stations other than magenta were not used for evaluation, leaving the existing photoconductor, toner, cleaning blade, and fur brush as they were.

  The evaluation results are shown in Table 5. Although the carrier conveyance tended to be less than in Example 1, it was still slightly observed in the discharged toner. However, there was little or almost no carrier reaching the blade, and there was no influence on the photoreceptor and the blade. Further, the toner cleaning property was practically satisfactory and the image quality was good.

1 is a schematic diagram illustrating an example of an image forming apparatus. It is a perspective view of the scraping roller provided with the fin which consists of films. It is a perspective view of the scraping roller provided with the fin which consists of brushes. It is the schematic which shows the other example of a scraping roller. It is explanatory drawing which shows typically the structure of a photoreceptor. It is explanatory drawing which shows typically the structure of another photoreceptor. It is a perspective view of a cleaning blade. It is a figure which shows the state which contacted the cleaning blade to the photoconductor. It is a figure which shows a mode when a photoreceptor is rotated from the state shown in FIG. It is sectional drawing which shows an example of a process cartridge. It is a schematic diagram showing an example of an image forming apparatus having a plurality of photoconductors.

Explanation of symbols

1, 1M, 1C, 1Y, 1BK Photoconductor 2 Charging device 3 Exposure device 4 Development device 8 Transfer device 12 Cleaning blade 14 Scraping roller 15 Support member 16 Fin 18 Holder 19 Reinforcing member 23 Process cartridge

Claims (12)

A rotatingly driven photoconductor, a charging device for charging the photoconductor, an exposure device for image-exposing the charged surface of the photoconductor to form an electrostatic latent image on the photoconductor, and the electrostatic latent image An image forming apparatus comprising: a developing device that visualizes a toner image; a transfer device that transfers the toner image to a transfer material; and a cleaning member that cleans the surface of the photoconductor after the toner image is transferred.
With respect to the moving direction of the surface of the photoconductor, the hard foreign material adhering to the surface of the photoconductor is scraped off from the surface of the photoconductor that is downstream of the transfer device and upstream of the cleaning member. The scraping roller has a support member and a plurality of fins whose base ends are fixed to the support member, and these fins are arranged at intervals in the circumferential direction of the support member. In addition, the fin is configured by a brush that is solidified with the tip portion thereof remaining. The image forming apparatus according to claim 1, wherein the brush is solidified leaving 1 to 3 mm at a tip portion thereof. The image forming apparatus according to claim 1, wherein an amount of biting of the fin into the photosensitive member is +1 mm to −0.2 mm. The photoreceptor is a photosensitive layer using a resin obtained by a crosslinking reaction of a crosslinkable charge transporting material containing a reactive hydroxyl group, a thermosetting resin monomer, and a thermosetting surfactant. The image forming apparatus according to claim 1, wherein the image forming apparatus is an electrophotographic photosensitive member. The image forming apparatus according to claim 1, wherein the cleaning member includes a cleaning blade pressed against the surface of the photoreceptor, and reinforcing members are attached to both surfaces of the cleaning blade. The image forming apparatus according to claim 5, wherein the reinforcing member is made of a film having a thickness of 25 to 300 μm. The cleaning blade has a JIS A hardness of 58 ° to 80 ° and is pressed against the surface of the photosensitive member in a counter direction with a contact pressure of 15 to 30 g / cm. The image forming apparatus described in 1. The image forming apparatus according to claim 5, wherein the cleaning blade is made of a strip-shaped rubber having a thickness of 1.5 to 3 mm. The cleaning blade is used in a state in which one edge portion on the front end side thereof is in pressure contact with the surface of the photoconductor, and also in a state in which the other edge portion on the front end side of the cleaning blade is in pressure contact with the surface of the photoconductor. The image forming apparatus according to claim 5, wherein a base end side opposite to a front end side of the cleaning blade is attached to the holder. The image forming apparatus according to claim 1, wherein a powdery lubricant is applied to the surface of the photoreceptor, or a lubricant is added to the outermost layer of the photoreceptor. A toner produced by a polymerization method and having an average circularity of 0.95 to 0.99 and an average particle diameter of 4 to 8 μm is used as a developer toner for visualizing an electrostatic latent image. The image forming apparatus according to claim 10. 12. A process cartridge comprising at least the photosensitive member according to claim 1 and a scraping roller assembled together, and detachably attached to an image forming apparatus main body.

Images