JP2011118050A - Cleaning member for electrifying member, electrifying device, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning member for an electrifying member which makes an electrifying member hardly stained and suppresses occurrence of an image quality defect such as irregular density even when it is kept for a long term in such a state that it contacts with the electrifying member while maintaining cleaning performance for the electrifying member. <P>SOLUTION: The cleaning member for an electrifying member includes an elastic layer having at least one area containing silicone oil and at least one area not containing silicone oil in a surface direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a charging member cleaning member, a charging device, a process cartridge, and an image forming apparatus.

  In an image forming apparatus using an electrophotographic method, first, a charge member is used to form a charge on the surface of an image carrier such as a photoconductive photosensitive member including an inorganic or organic material, and an image signal is generated. After forming an electrostatic latent image with modulated laser light or the like, the electrostatic latent image is developed with charged toner to form a visualized toner image. The toner image is electrostatically transferred to a recording material such as a recording sheet via an intermediate transfer member or directly, and the toner image is fixed on the recording material, thereby obtaining a desired image.

  In recent years, in an electrophotographic image forming apparatus, a charging roll is frequently used as a charging member for charging the surface of the image carrier as a member to be charged. The charging roll comes into contact with the image holding member in a state where a voltage is applied, and discharges in a minute gap between the charging roller and the surface of the image holding member. The charging roll is strictly controlled in resistance, shape, and the like in order to charge the image carrier as uniformly as possible.

  In an electrophotographic image forming apparatus using a charging member such as a charging roll, foreign matters such as transfer residual toner, residual toner additives, and paper dust adhered to the surface of the image holding member , The foreign matter may adhere to the surface of the charging roll and contaminate the charging roll. Therefore, as a cleaning member (cleaning member) for the charging roll, for example, a cleaning roll and a cleaning pad as shown in Patent Document 1 have been proposed.

  Patent Document 2 includes a shaft that is rotatably supported to remove dirt without damaging the surface of the charging roll, and a mixed member that is provided around the shaft and has different cleaning performance. A cleaning device configured as described above is described.

JP-A-2-272594 JP 2007-199414 A

  The object of the present invention is to maintain the cleaning property of the charging member, and to prevent the charging member from being contaminated and suppressing the occurrence of image quality defects such as density unevenness even when stored for a long time in contact with the charging member. A cleaning member, a charging device, a process cartridge, and an image forming apparatus are obtained.

  The above object is achieved by the present invention described below. That is, the invention according to claim 1 is a charging member cleaning member including an elastic layer having a region including at least one silicon-based oil and a region not including at least one silicon-based oil in a surface direction.

  The invention according to claim 2 is a cylindrical shape having a core material, a region including at least one silicon-based oil and a region not including at least one silicon-based oil formed in the outer periphery of the core material in the circumferential direction. And a charging member cleaning member.

  The invention according to claim 3 is the charging member cleaning member according to claim 1 or 2, wherein the region that does not contain the silicon-based oil includes polyester-based polyurethane.

  According to a fourth aspect of the present invention, there is provided a charging member and the charging member cleaning member according to any one of the first to third aspects. When the charging member is not in operation, the charging member is silicon of the charging member cleaning member. The charging device is in contact with or opposed to a region not containing the system oil.

  The invention according to claim 5 is a process cartridge comprising an image carrier and the charging device according to claim 4.

  The invention according to claim 6 is formed on the surface of the image carrier, the charging device according to claim 4, latent image forming means for forming a latent image on the surface of the image carrier, and the surface of the image carrier. An image forming apparatus comprising: a developing unit that develops the latent image with toner to form a toner image; and a transfer unit that transfers the toner image formed on the surface of the image holding member to a transfer target.

  According to claim 1 of the present invention, while maintaining the cleaning property of the charging member as compared with the case where the elastic layer does not have a region containing silicon-based oil and a region not containing silicon-based oil in the surface direction, Provided is a charging member cleaning member that hardly contaminates the charging member even when stored for a long period in contact with the charging member and suppresses the occurrence of image quality defects such as density unevenness.

  According to claim 2 of the present invention, while maintaining the cleaning property of the charging member as compared with the case where the elastic layer does not have a region containing silicon-based oil and a region not containing silicon-based oil in the circumferential direction, Provided is a charging member cleaning member that hardly contaminates the charging member even when stored for a long period in contact with the charging member and suppresses the occurrence of image quality defects such as density unevenness.

  According to claim 3 of the present invention, the region not including the silicon-based oil is in contact with the charging member while maintaining the cleaning property of the charging member as compared with the case where the region not including the polyester-based polyurethane is included. Provided is a charging member cleaning member that hardly contaminates the charging member even when stored for a long time and suppresses the occurrence of image quality defects such as density unevenness.

  According to the fourth aspect of the present invention, the charging member cleaning member is more easily cleaned than the case where the elastic layer of the charging member cleaning member does not have a region containing silicon oil and a region not containing silicon oil in the surface direction. A charging device is provided that suppresses the occurrence of image quality defects such as uneven density even when the charging member is stored for a long time in contact with the charging member while maintaining the above.

  According to the fifth aspect of the present invention, the charging member cleaning member is more easily cleaned than the case where the elastic layer of the charging member cleaning member does not have a region containing silicon oil and a region not containing silicon oil in the surface direction. A process cartridge is provided that suppresses the occurrence of image quality defects such as uneven density even when the charging member is stored for a long time in contact with the charging member.

  According to the sixth aspect of the present invention, the charging member cleaning member can be cleaned more easily than the case where the elastic layer of the charging member cleaning member does not have a region containing silicon oil and a region not containing silicon oil in the surface direction. An image forming apparatus is provided that suppresses the occurrence of image quality defects such as uneven density even when the charging member is stored for a long time in contact with the charging member.

FIG. 3 is a schematic cross-sectional configuration diagram in the direction perpendicular to the axis of the roll, showing an example of a cleaning roll that is a charging member cleaning member according to an embodiment of the present invention. It is a schematic sectional block diagram of the orthogonal | vertical direction to the axis | shaft of a roll which shows the other example of the cleaning roll which is a charging member cleaning member which concerns on embodiment of this invention. It is a schematic structure figure seen from the front of the cleaning surface of a pad which shows an example of the cleaning pad which is an electrification member cleaning member concerning an embodiment of the present invention. It is a side view showing a schematic structure of an example of a charging device using a charging member cleaning member according to an embodiment of the present invention. It is a front view which shows schematic structure of an example of the charging device using the charging member cleaning member which concerns on embodiment of this invention. It is a side view which shows schematic structure of the other example of the charging device using the charging member cleaning member which concerns on embodiment of this invention. It is a schematic structure figure showing an example of a process cartridge concerning an embodiment of the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. It is a schematic block diagram which shows the other example of the image forming apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  In an electrophotographic image forming apparatus using a charging member such as a charging roll, adhered foreign matters are usually removed by a cleaning roll or a cleaning pad as a cleaning member for the charging roll. As a cleaning member, it is mainstream to use a foam type from the standpoint of easy removal of foreign matter, and as a material, it is mainstream to use urethane with a small permanent distortion from the viewpoint of cleaning maintenance. . Polyols that are raw materials for urethane are known as polyether polyols, polyester polyols, etc., but polyester polyurethanes that use polyester polyols as raw materials are prone to hydrolysis, so that they can be stored under high humidity. Therefore, polyurethane using a polyether-based polyol using a polyether polyol as a raw material is often used.

  When polyether-based polyurethane is used as a cleaning member, image quality defects such as uneven density due to contamination of the charging roll by silicone-based foam stabilizers such as silicone-based oils that are commonly used for polyurethane during long-term storage May occur. On the other hand, since such a silicon-based foam stabilizer is not usually used for polyester-based polyurethane, the image quality defect is less likely to occur.

  The present inventors maintain the cleaning property of the charging member by using a member having an elastic layer having a region containing silicon oil and a region not containing silicon oil in the surface direction as a cleaning member for the charging member. However, it has been found that even when stored for a long period in contact with the charging roll, the charging roll is hardly contaminated and the occurrence of image quality defects such as density unevenness is suppressed.

<Charging member cleaning member>
The charging member cleaning member according to the embodiment of the present invention includes an elastic layer having a region including at least one silicon-based oil and a region not including at least one silicon-based oil in the surface direction. The structure of the charging member cleaning member is not particularly limited as long as the charging member cleaning function is satisfied while satisfying this requirement. It is preferable that the structure is such that contamination or the like does not occur as much as possible. Such a charging member cleaning member may have a pad shape or a roll shape. Here, the roll shape will be mainly described as an example, but the present invention is not limited to this.

  FIG. 1 is a schematic cross-sectional configuration diagram in the direction perpendicular to the axis of the roll, showing an example of a cleaning roll that is a charging member cleaning member according to the present embodiment. A cleaning roll 10 that is a charging member cleaning member includes a core material 12 and an elastic layer 18 formed on the outer periphery of the core material 12. The elastic layer 18 has a silicon-based oil-containing region 14 containing a silicon-based oil and a silicon-based oil non-containing region 16 not containing a silicon-based oil in the surface direction (also called a circumferential direction in the case of a roll).

  In a state where the cleaning roll 10 of FIG. 1 is mounted on the image forming apparatus and is not operating, the silicon oil-free region 16 of the cleaning roll 10 is controlled to contact the charging member. As a result, even if the charging member is kept clean while maintaining contact with the charging roll for a long period of time, the charging roll is less likely to be contaminated and the occurrence of image quality defects such as density unevenness is suppressed. Lifetime image quality is obtained. Further, since the silicon-based oil-containing region 14 containing the silicon-based oil is provided, the frictional force between the charging member and the elastic layer 18 of the charging member cleaning member is reduced during cleaning of the charging member. A phenomenon in which foreign matter such as generated abrasive powder moves to the charging member to cause image quality defects such as a color point is suppressed. The shape of the silicon oil non-containing region 16 is such that the silicon oil non-containing region 16 is in contact with the charging member and the silicon oil containing region 14 is not in contact with the charging member when the cleaning roll 10 is not operating. However, the shape is not limited to that shown in FIG.

  FIG. 2 is a schematic cross-sectional configuration diagram in the direction perpendicular to the axis of the roll, showing another example of a cleaning roll that is a charging member cleaning member according to the present embodiment. A cleaning roll 10 that is a charging member cleaning member includes a core material 12 and an elastic layer 18 formed on the outer periphery of the core material 12. The elastic layer 18 has a silicon-based oil-containing region 14 containing silicon-based oil and a notch portion that is a silicon-based oil non-containing region 17 not containing silicon-based oil in the surface direction (circumferential direction).

  In a state where the cleaning roll 10 of FIG. 2 is mounted on the image forming apparatus and is not operating, control is performed so that the silicon oil-free region 17 of the cleaning roll 10 faces the charging member. As the shape of the notch, the notch which is the silicon-based oil-free region 17 faces the charging member when the cleaning roll 10 is not operating, and the silicon-based oil-containing region 14 and the charging member do not contact each other. What is necessary is just to do it, and it is not restricted to the shape of FIG.

  FIG. 3 is a schematic configuration diagram illustrating an example of a cleaning pad that is a charging member cleaning member according to the present embodiment, as viewed from the front of the cleaning surface of the pad. The cleaning pad 11 that is a charging member cleaning member includes an elastic layer 18. The elastic layer 18 has a silicon-based oil-containing region 14 containing a silicon-based oil and a silicon-based oil non-containing region 16 not containing a silicon-based oil in the surface direction.

  In a state where the cleaning pad 11 of FIG. 3 is mounted on the image forming apparatus and is not operating, the silicon oil-free region 16 of the cleaning pad 11 is controlled so as to contact the charging member. The shape of the silicon-based oil-free region 16 is such that the silicon-based oil-free region 16 is in contact with the charging member while the cleaning pad 11 is not operating, and the silicon-based oil-containing region 14 is not in contact with the charging member. The shape is not limited to the shape shown in FIG.

  Here, “silicone oil” in the present specification has a dimethylsiloxane structure. Examples of the compound having such a structure include polydimethylsiloxane and polyether-modified silicone oil. Such silicone oil is used as a silicone foam stabilizer in the production of polyurethane or the like, for example.

  The “silicon oil-free region” refers to a region where the silicon concentration in Si 2 p measured by X-ray photoelectron spectroscopy (XPS analysis) for the elastic layer 18 is less than 0.5 atm%. Further, the “silicon oil-containing region” refers to a region where the silicon concentration in Si 2p measured by X-ray photoelectron spectroscopy (XPS analysis) is 0.5 atm% or more. Specifically, the silicon concentration is obtained by cutting out the elastic layer 18 at a 3 mm square at three positions parallel to the core and at equal intervals, and using a photoelectron spectrometer JPS-9010MX (manufactured by JEOL Ltd.), the silicon component in Si2p Determine based on the ratio of all elements.

  The elastic layer 18 may have at least one silicon-based oil-containing region 14 and at least one silicon-based oil-free region 16 along the surface direction of the elastic layer 18, and the configuration is particularly limited. There is no. The area of the cleaning surface of one silicon-based oil-free region 16 is preferably in the range of 5% to 50% and preferably in the range of 5% to 30% of the entire cleaning surface of the elastic layer 18. Is more preferable. If the area of the cleaning surface of one silicon-based oil-free region 16 is less than 5%, the silicon-based oil-containing region may enter the nip portion with the charging roll when stopped, and if it exceeds 50%, Since the rubbing force between the charging member and the elastic layer 18 of the charging member cleaning member is reduced during the cleaning of the member, foreign matter such as abrasive powder generated during the production of the elastic layer moves to the charging member and the image quality such as the color point. Defects may occur. Further, the total area of the cleaning surface of the silicon-based oil-free region 16 is preferably in the range of 5% to 50% of the entire area of the cleaning surface of the elastic layer 18, and in the range of 7% to 30%. More preferably. If the area of the cleaning surface of the total silicon-based oil-free region 16 is less than 5%, the silicon-based oil-containing region may enter the nip portion with the charging roll at the time of stoppage. Since the rubbing force between the charging member and the elastic layer 18 of the charging member cleaning member is reduced during the cleaning of the member, foreign matter such as abrasive powder generated during the production of the elastic layer moves to the charging member and the image quality such as the color point. Defects may occur.

  Further, in this specification, the “non-operating state” means, for example, other than the state in which image formation is not performed after the charging device including the charging member cleaning member according to this embodiment is mounted on the image forming device. The charging device including the charging member cleaning member according to the present embodiment refers to a state where the charging device is stored and transported during or after manufacture.

  Examples of the material used for the core 12 of the roll-shaped cleaning roll 10 include metals such as free-cutting steel and stainless steel, and resins such as polyacetal (POM). It is preferable to appropriately select the material of the core material 12, the surface treatment method, and the like according to the use such as slidability. In particular, in the case of a metal, it is preferable to perform plating treatment from the viewpoint of rust prevention or the like. Further, in the case of a material such as a resin that does not have conductivity, it may be processed by a general process such as a plating process, and may be used as it is.

  The configuration of the elastic layer 18 on the core material 12 may be a single layer or a stacked configuration of two or more layers. The elastic layer 18 may be configured to include a foam or a two-layer configuration including a solid layer and a foamed layer. By configuring the elastic layer 18 so that the charging member can be cleaned, a function as a cleaning roll can be obtained.

  Examples of the material constituting the elastic layer 18 include foamable resins such as polyurethane, polyethylene, polyamide, and polypropylene, or silicone rubber, fluorine rubber, urethane rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), Use a material made by mixing one or more rubber materials such as chloroprene rubber (CR), chlorinated polyisoprene rubber, isoprene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, hydrogenated polybutadiene rubber, and butyl rubber. May be. If necessary, auxiliary agents such as foaming aids, foam stabilizers, catalysts, curing agents, plasticizers, and vulcanization accelerators may be added to these.

  In order to prevent the surface of the charging member from being scratched as much as possible, and to prevent tearing and breakage as much as possible over a long period of time, it is preferable to use foamed polyurethane that is resistant to tearing and pulling. Although it does not restrict | limit especially as a polyurethane, For example, polyols, such as a polyester polyol, polyether polyol, an acryl polyol, 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, 4, 4- diphenylmethane diisocyanate , Tolidine diisocyanate, 1,6-hexamethylene diisocyanate, and the like obtained by reaction with isocyanate. Further, a chain extender such as 1,4-butanediol or trimethylolpropane may be mixed. Foaming may be performed using a foaming agent such as water, azodicarbonamide, azo compounds such as azobisisobutyronitrile. Furthermore, you may add auxiliary agents, such as a foaming aid, a foam stabilizer, a catalyst, as needed.

  Examples of the foam stabilizer include silicone foam stabilizers such as the above-mentioned silicone oil.

  Usually, a polyether-based polyurethane in which a silicone-based foam stabilizer such as silicone-based oil is used at the time of manufacture is used as the elastic layer 18 of the silicone-based oil-containing region 14 from the viewpoint of excellent stability when stored for a long period of time. Is preferred. Moreover, although it is somewhat inferior in stability when stored for a long period of time, a polyester polyurethane in which a silicone foam stabilizer such as silicone oil is not used at the time of manufacture is usually used as the elastic layer 18 of the silicone oil-free region 16. It is preferable to use it.

  The method for producing the charging member cleaning member is not particularly limited as long as the elastic layer 18 is produced using a material containing silicon oil and a material not containing silicon oil. For example, what is necessary is just to produce using the material which does not contain silicon type oil in at least one part of the surface direction of the elastic layer 18. FIG. As these manufacturing methods, for example, a plurality of injection paths may be provided at the time of injection molding, and a material containing silicon oil and a material not containing silicon oil may be separately poured from each injection path. . Moreover, what is necessary is just to produce with the same view also in extrusion molding. In these molding methods, there is a possibility that the respective material interfaces become non-uniform, but this is not out of the scope of the present embodiment.

<Charging member and charging device>
FIG. 4 is a side view showing a schematic configuration of an example of a charging device using the charging member cleaning member according to the present embodiment. FIG. 5 is a front view showing a schematic configuration of an example of the charging device according to the present embodiment. A charging device 1 in FIG. 4 is a charging member that charges the surface of an image carrier provided in the image forming apparatus, and is in contact with the charging roll 20 and a charging roll 20 that is a cylindrical charging member that rotates about the axis. And a cleaning roll 10 which is a charging member cleaning member for cleaning the surface of the charging roll 20. The charging roll 20 includes a conductive core material 22 and a charging layer 24 formed on the outer periphery of the conductive core material 22. The cleaning roll 10 includes a core material 12 and a cylindrical elastic layer 18 formed on the outer periphery of the core material 12. The elastic layer 18 includes a silicon-based oil-containing region 14 containing silicon-based oil and silicon-based oil. A silicon-based oil non-containing region 16 not included is included in the surface direction (circumferential direction).

  As shown in FIG. 5, in the charging device 1, the charging roll 20 is configured such that the photosensitive member 26 has an elastic member such as a coil spring 28 installed at both ends of the conductive core member 22 with respect to the photosensitive member 26 that is an image holding member. It is pressed against the surface and follows the photoreceptor 26. On the other hand, the cleaning roll 10 is held by the bearing 30 at a bearing distance between the conductive core material 22 of the charging roll 20 and the core material 12 of the cleaning roll 10, and the cleaning roll 10 has a predetermined nip amount. Follow. The charging roll 20 and the cleaning roll 10 may be driven by the photosensitive member 26 and the charging roll 20, respectively, or may be driven separately.

  As shown in FIG. 4, when the cleaning roll 10 is mounted on the image forming apparatus and is not operating, the silicon oil-free region 16 of the cleaning roll 10 is controlled so as to come into contact with the charging roll 20. When the cleaning roll 10 has a notch portion as shown in FIG. 2 as the silicon-based oil-free region 16, the notch of the cleaning roll 10 is in a state where the cleaning roll 10 is not installed and operating in the image forming apparatus. The part is controlled to face the charging roll 20.

  FIG. 6 is a side view showing a schematic configuration of another example of the charging device using the charging member cleaning member according to the present embodiment. A charging device 1 in FIG. 6 is a charging member that charges the surface of an image carrier provided in the image forming apparatus, and is a cylindrical charging member that rotates about an axis, and a charging roller 20 that contacts the charging roller 20. And a cleaning pad 11 which is a charging member cleaning member for cleaning the surface of the charging roll 20. The cleaning roll 10 includes a plate-like elastic layer 18.

  As shown in FIG. 6, when the cleaning pad 11 is mounted on the image forming apparatus and is not operating, the silicon oil-free region 16 of the cleaning pad 11 is controlled so as to contact the charging roll 20.

  Hereinafter, a charging roll as a charging member will be described. However, the charging roll is not limited to the following configuration as long as it has a predetermined charging performance so as to charge an image holding member as a charged body.

  The charging roll 20 includes at least a conductive core 22 and a charging layer 24 including a resin layer instead of an elastic layer or an elastic layer. The elastic layer may be composed of a single layer, or may be composed of a plurality of different layers having a number of functions. Furthermore, surface treatment may be performed on the elastic layer.

  Examples of the material used for the conductive core material 22 include metals such as free-cutting steel and stainless steel, and it is preferable to appropriately select the material, the surface treatment method, and the like according to applications such as slidability. Plating is preferred from the viewpoint of rust prevention and the like. In the case of a material that does not have conductivity, it may be processed by a general process such as a plating process to perform a conductive process, or may be used as it is.

  In order to obtain a predetermined charging performance, the elastic layer is a conductive elastic layer. This conductive elastic layer is, for example, an elastic material such as rubber having elasticity, carbon black for adjusting the resistance of the conductive elastic layer, or the like. Conductive materials such as ionic conductive agents, softeners, plasticizers, curing agents, vulcanizing agents, vulcanization accelerators, anti-aging agents, fillers such as silica and calcium carbonate, etc. are usually added to rubber as necessary. Materials may be added. The conductive elastic layer is formed by coating a peripheral surface of a conductive support shaft with a mixture to which a material usually added to rubber is added. As a conductive agent for the purpose of adjusting the resistance value, a material in which a material that conducts electricity using at least one of electrons and ions as a charge carrier, such as carbon black or an ionic conductive agent blended in a matrix material, is dispersed. It may be used. The elastic material may be a foam.

  The elastic material constituting the conductive elastic layer is formed, for example, by dispersing a conductive agent in a rubber material. Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, urethane rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide. -Allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber, natural rubber, etc., and blended rubbers thereof. Among these, silicone rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber, and blended rubbers thereof are preferably used. These rubber materials may be foamed or non-foamed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide And fine powders such as various conductive metal oxides such as tin oxide-antimony oxide solid solution, tin oxide-indium oxide solid solution, and the like. Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals Is mentioned.

  These conductive agents may be used alone or in combination of two or more. Further, the amount of addition is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 part by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the rubber material. In the case of an agent, it is preferably in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the rubber material.

  A surface layer may be formed on the surface of the charging roll 20 in order to prevent contamination by foreign matters such as toner. As the material for the surface layer, any of resin, rubber and the like may be used, and there is no particular limitation. As resin and rubber, polyester, polyimide, copolymer nylon, silicone resin, acrylic resin, polyvinyl butyral, ethylenetetrafluoroethylene copolymer, melamine resin, fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride , Polyvinyl chloride, polyethylene, ethylene vinyl acetate copolymer and the like.

  Of these, polyvinylidene fluoride, a tetrafluoroethylene copolymer, polyester, polyimide, and copolymer nylon are preferably used from the viewpoint of contamination of external additives. The copolymer nylon includes one or more of 610 nylon, 11 nylon, and 12 nylon as polymerized units, and other polymer units contained in the copolymer include 6 nylon, 66 nylon and the like. Here, the proportion of polymer units such as 610 nylon, 11 nylon, and 12 nylon contained in the copolymer is preferably 10% or more in total by weight ratio. When the above polymerized unit is 10% or more, it has excellent liquid preparation properties and film formability at the time of coating the surface layer, and particularly less wear of the surface layer and adhesion of foreign matter to the surface layer during repeated use, and durability of the roll. And changes in properties due to the environment tend to be reduced.

  The polymer materials (resins) may be used alone or in combination of two or more. Further, the number average molecular weight of the polymer material is preferably in the range of 1,000 or more and 100,000 or less, and more preferably in the range of 10,000 or more and 50,000 or less.

  The surface layer may contain a conductive material to adjust the resistance value. The conductive material preferably has a particle size of 3 μm or less.

  In addition, as a conductive agent for adjusting the resistance value, at least one of electrons and ions such as carbon black, conductive metal oxide particles, or ionic conductive agent blended in the matrix material is used as a charge carrier. A material in which a material that conducts electricity is dispersed may be used.

  Specifically, carbon black as a conductive agent includes “Special Black 350”, “Special Black 100”, “Special Black 250”, “Special Black 5”, “Special Black 4” manufactured by Degussa, "Special Black 4A", "Special Black 550", "Special Black 6", "Color Black FW200", "Color Black FW2", "Color Black FW2V", "MONARCH1000" manufactured by Cabot, Cabot “MONARCH1300” manufactured by the company, “MONARCH1400” manufactured by Cabot, “MOGUL-L”, “REGAL400R”, and the like.

  The carbon black has a pH of 4.0 or less, and has better dispersibility in the resin composition due to the effect of the oxygen-containing functional group present on the surface compared to general carbon black. By blending, there is a tendency that the charging uniformity is improved and the fluctuation of the resistance value is further reduced.

  The conductive metal oxide particles, which are conductive particles for adjusting the resistance value, are conductive particles such as tin oxide, tin oxide doped with antimony, zinc oxide, anatase titanium oxide, and ITO. Any conductive agent using electrons as charge carriers may be used without any particular limitation. These may be used alone or in combination of two or more. In addition, any particle size may be used as long as the effect of the present embodiment is not hindered, but from the viewpoint of resistance value adjustment and strength, etc., preferably tin oxide, antimony-doped tin oxide, anatase-type titanium oxide More preferred are tin oxide and tin oxide doped with antimony.

  By performing resistance control with such a conductive material, the resistance value of the surface layer does not change depending on environmental conditions, and stable characteristics can be obtained.

  Furthermore, it is preferable that the surface layer is made of a fluorine-based or silicone-based resin, particularly including a fluorine-modified acrylate polymer. Further, fine particles may be added to the surface layer. As a result, the surface layer becomes hydrophobic and acts to prevent the adhesion of foreign matter to the charging roll. In addition, insulating particles such as alumina and silica are added to give unevenness to the surface of the charging roll, reducing the burden during rubbing with the photosensitive drum, and reducing the mutual relationship between the charging roll and the image carrier. The wear resistance may be improved.

  The outer diameter of the charging roll 20 is preferably 8 mm or greater and 16 mm or less. From the viewpoint of miniaturization of the image forming apparatus, φ14 mm or less is preferable. If φ8 mm or less, the number of times of contact with the external additive per peripheral surface of the charging roll increases and the number of discharges increases, which is disadvantageous for long-term stability. There is a case. The outer diameter may be measured using a commercially available caliper or a laser type outer diameter measuring device.

  The micro hardness of the charging roll 20 is preferably 45 ° or more and 60 ° or less. If it becomes harder than 60 °, even when a charging member cleaning member is attached, it is difficult to ensure nip stability with the image carrier, and image quality density unevenness may occur. When it becomes softer than 45 °, nip stability with the image carrier is ensured even when there is no charging member cleaning member. However, in order to reduce the hardness, a method of increasing the amount of plasticizer added, a method of using a low hardness material such as silicone rubber, and the like are conceivable. In the former case, the plasticizer may bleed and cause problems such as image quality deterioration, and in the latter case, the cost may increase significantly.

  Further, the micro hardness of the charging roll 20 may be a value measured with a MD-1 type hardness meter manufactured by Kobunshi Keiki Co., Ltd.

<Process cartridge>
The process cartridge according to the present embodiment includes an image carrier, a charging member that charges the surface of the image carrier, and the charging member cleaning member. The process cartridge according to this embodiment includes a latent image forming unit that forms a latent image on the surface of the charged image carrier, and a toner that develops the latent image formed on the surface of the image carrier with toner as necessary. From the group consisting of developing means for forming an image, transfer means for transferring the toner image formed on the surface of the image carrier to the transfer target, and image carrier cleaning means for cleaning the surface of the image carrier after transfer You may provide at least 1 type selected.

  A schematic configuration of an example of the process cartridge according to the embodiment of the present invention is shown in FIG. 7, and the configuration will be described. The process cartridge 3 includes a photoconductor (electrophotographic photoconductor) 26 as an image carrier on which an electrostatic latent image is formed, a cylindrical charging roll 20 as a charging member that contacts and charges the surface of the photoconductor 26, A toner image is formed by adhering toner to the cleaning roller 10 as a charging member cleaning member that contacts the charging roller 20 and cleans the surface of the charging roller 20, and the electrostatic latent image formed on the surface of the photoreceptor 26. A developing roll 52 as a developing unit and a cleaning blade 56 as an image carrier cleaning unit that contacts the surface of the photosensitive member 26 and cleans toner remaining on the photosensitive member 26 after transfer are integrally supported. It is detachable from the image forming apparatus. When mounted on the image forming apparatus, an exposure device 58 serving as a latent image forming unit that forms an electrostatic latent image on the surface of the photosensitive member 26 around the photosensitive member 26 by the charging roll 20, laser light, or reflected light of the document. The developing roll 52, the transfer roll 54 as a transfer means for transferring the toner image on the surface of the photosensitive member 26 to the recording paper 62 as the transfer target, and the cleaning blade 56 are arranged in this order. As described above, the elastic layer of the cleaning roll 10 has a silicon-based oil-containing region containing silicon-based oil and a silicon-based oil non-containing region not containing silicon-based oil in the surface direction (circumferential direction). In FIG. 7, functional units normally required in other electrophotographic processes are not shown.

  The operation of the process cartridge 3 according to this embodiment will be described.

  First, the surface of the photoconductor 26 is uniformly charged to a high potential by supplying a voltage from a high-voltage power supply (not shown) to the charging roll 20 in contact with the surface of the photoconductor 26. At this time, the photosensitive member 26 and the charging roll 20 rotate in the directions of arrows in FIG. After charging, when image light (exposure) 60 corresponding to image information is irradiated onto the surface of the photosensitive member 26 by the exposure device 58, the potential of the irradiated portion decreases. Since the image light 60 has a light amount distribution corresponding to the black / white of the image, a potential distribution corresponding to the recorded image, that is, an electrostatic latent image is formed on the surface of the photoconductor 26 by the irradiation of the image light 60. When the portion where the electrostatic latent image is formed passes through the developing roll 52, toner adheres according to the level of the potential, and a toner image in which the electrostatic latent image is visualized is formed. The recording paper 62 is conveyed to a portion where the toner image is formed by a resist roll (not shown) at a predetermined timing, and overlaps the toner image on the surface of the photoreceptor 26. After the toner image is transferred to the recording paper 62 by the transfer roll 54, the recording paper 62 is separated from the photoreceptor 26. The separated recording paper 62 is transported through a transport path, fixed by heating and pressure by a fixing unit (not shown) as fixing means, and then discharged outside the apparatus.

  The charging roll 20 provided in the process cartridge 3 is provided with a cleaning roll 10, a voltage is applied to the bearing 30 from a high voltage power source, and the cleaning roll 10 has the same polarity as the charging roll 20, thereby removing foreign matter. Since it moves with little accumulation on the surfaces of the cleaning roll 10 and the charging roll 20 and is collected by the cleaning blade 56, foreign matters such as toner adhering to the charging member are stably removed over a long period of time. For this reason, a stable charging performance is maintained with little accumulation of dirt on the charging roll 20 over a long period of time.

  The photoreceptor 26 has a function of forming at least an electrostatic latent image (electrostatic charge image). In the electrophotographic photosensitive member, an undercoat layer, a charge generation layer containing a charge generation material, and a charge transport layer containing a charge transport material are formed in this order on the outer peripheral surface of a cylindrical conductive substrate as necessary. It is a thing. The order of stacking the charge generation layer and the charge transport layer may be reversed. These are laminated photoconductors in which a charge generation material and a charge transport material are contained in separate layers (charge generation layer, charge transport layer), but both the charge generation material and the charge transport material are the same. A single-layer type photoreceptor included in the above layer may be used, and a laminated photoreceptor is preferable. Further, an intermediate layer may be provided between the undercoat layer and the photosensitive layer. Further, a protective layer may be provided on the photosensitive layer. In addition, other types of photosensitive layers such as an amorphous silicon photosensitive film may be used in addition to the organic photoreceptor.

  The exposure device 58 is not particularly limited. For example, a laser optical system capable of exposing a light source such as semiconductor laser light, LED light, or liquid crystal shutter light on the surface of the photosensitive member 26 in a desired image-like manner, or an optical such as an LED array. System equipment.

  The developing means has a function of developing the electrostatic latent image formed on the photoreceptor 26 with a one-component developer or a two-component developer containing an electrostatic charge image developing toner to form a toner image. Such a developing device is not particularly limited as long as it has the above-described function, and may be appropriately selected according to the purpose. Even a system in which the toner layer is in contact with the photosensitive member 26, a system in which the toner layer is not in contact is used. It may be a thing. For example, as shown in FIG. 8, a developer having a function of attaching toner for developing an electrostatic charge image to the photoreceptor 26 using the developing roll 52, or a development having a function of attaching the toner to the photoreceptor 26 using a brush or the like. And a known developing device.

  The transfer unit may be a type that directly transfers to paper or the like, or a type that transfers via an intermediate transfer member. For example, a transfer roll 54 and a transfer roll pressing device (not shown) using a conductive or semiconductive roll that directly transfers through a recording sheet 62 as shown in FIG. 7 may be used. Further, a recording sheet 62 may be used in which a charge having a polarity opposite to that of the toner is applied to the recording sheet 62 from the back side (the side opposite to the photoreceptor) of the recording sheet 62 and the toner image is transferred to the recording sheet 62 by electrostatic force. The transfer roll 54 may be arbitrarily set depending on the width of the image area to be charged, the shape of the transfer charger, the opening width, the process speed (circumferential speed), and the like. Further, a single layer foam roll or the like is preferably used as the transfer roll 54 for cost reduction.

  The fixing unit as the fixing unit is not particularly limited as long as the toner image transferred onto the recording paper 62 is fixed by heating, pressing, or heating and pressing.

  Examples of the recording paper 62 that is a transfer target to which the toner image is transferred include plain paper, OHP sheet, and the like used in electrophotographic copying machines and printers. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer material is as smooth as possible. Preferably used.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes an image carrier, a charging member that charges the surface of the image carrier, the charging member cleaning member, and a latent image forming unit that forms a latent image on the surface of the image carrier. And a developing means for developing the latent image formed on the surface of the image carrier with toner to form a toner image. The image forming apparatus according to the present embodiment includes a transfer unit that transfers a toner image formed on the surface of the image carrier to the transfer target, and an image carrier cleaning that cleans the surface of the image carrier after the transfer, as necessary. You may provide at least 1 type selected from the group which consists of means. The image forming apparatus according to the present embodiment may use the process cartridge.

  FIG. 8 shows a schematic configuration of an example of the image forming apparatus according to the present embodiment, and the configuration will be described. The image forming apparatus 5 includes a photosensitive member 26 as an image carrier on which an electrostatic latent image is formed, a cylindrical charging roll 20 as a charging member that contacts and charges the surface of the photosensitive member 26, and a contact with the charging roll 20. Then, the cleaning roll 10 as a charging member cleaning member for cleaning the surface of the charging roll 20 and exposure as a latent image forming means for forming an electrostatic latent image on the surface of the photosensitive member 26 by laser light or reflected light of the document. The apparatus 58, a developing roll 52 as a developing unit that forms a toner image by attaching toner to the electrostatic latent image formed on the surface of the photosensitive member 26, and the toner image on the surface of the photosensitive member 26 are transferred members. A transfer roll 54 serving as a transfer unit that performs transfer processing on the recording paper 62, and a cleaner serving as an image carrier cleaning unit that contacts the surface of the photoconductor 26 and cleans toner remaining on the photoconductor 26 after transfer. And a ring blade 56. In the image forming apparatus 5, a charging roll 20, an exposure device 58, a developing roll 52, a transfer roll 54, and a cleaning blade 56 are arranged around the photoreceptor 26 in this order. As described above, the elastic layer of the cleaning roll 10 has a silicon-based oil-containing region containing silicon-based oil and a silicon-based oil non-containing region not containing silicon-based oil in the surface direction (circumferential direction). In FIG. 8, functional units normally required in other electrophotographic processes are not shown. Each configuration of the image forming apparatus 5 and operations during image formation are the same as those of the process cartridge 3 of FIG.

  FIG. 9 shows a tandem full-color image forming apparatus 5. Inside the image forming apparatus 5, a photoconductor (photosensitive drum) 26, a charging roll 20, a developing device, and the like are provided in yellow (64Y), magenta (64M), cyan (64C), and black (64K) colors. Each is arranged as a cartridge state. The photosensitive member 26 is made of, for example, a conductive cylindrical body having a diameter of about 25 mm and having a surface coated with a photosensitive layer, and is driven to rotate at a process speed of about 150 mm / sec by a motor (not shown). .

  The surface of the photoconductor 26 is charged to a predetermined potential by a charging roll 20 disposed beside the photoconductor 26, and then subjected to image exposure with a laser beam or the like emitted from an exposure device 58, whereby image information is converted into image information. A corresponding electrostatic latent image is formed.

  The electrostatic latent image formed on the photoreceptor 26 is developed by yellow (Y), magenta (M), cyan (C), and black (K) developing devices 66Y, 66M, 66C, and 66K. A toner image of a predetermined color is obtained.

  For example, when a full-color image is formed, charging, exposure, and development processes are performed on the surface of each color photoconductor 26 in yellow (Y), magenta (M), cyan (C), and black (K). A toner image corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) is formed on the surface of the photoreceptor 26 of each color.

  The yellow (Y), magenta (M), cyan (C), and black (K) toner images sequentially formed on the photosensitive member 26 are conveyed on the sheet conveying belt 68 to the outer periphery of the photosensitive member 26. Transferred to the recording paper 62. Further, the recording paper 62 onto which the toner image has been transferred from the photoreceptor 26 is conveyed to the fixing device 70, and is heated and pressed by the fixing device 70 to fix the toner image on the recording paper 62. Thereafter, in the case of single-sided printing, the recording paper 62 on which the toner image is fixed is discharged as it is onto a discharge tray 74 provided on the upper part of the image forming apparatus 5 by a discharge roll 72.

  On the other hand, in the case of double-sided printing, the recording paper 62 having the toner image fixed on the first surface (front surface) by the fixing device 70 is not directly discharged onto the discharge tray 74 by the discharge roll 72 but is discharged as it is. With the rear end portion of the recording paper 62 held between the two, the discharge roll 72 is reversed, the conveyance path of the recording paper 62 is switched to the double-sided paper conveyance path 76, and the double-sided paper conveyance path 76 is arranged. With the conveying roller 78 provided, the recording paper 62 is reversed and conveyed to the paper conveying belt 68 again, and a toner image is formed on the second surface (back surface) of the recording paper 62 from the photosensitive member 26. Transcript. Then, the toner image on the second surface (back surface) of the recording paper 62 is fixed by the fixing device 70, and the recording paper 62 is discharged onto the discharge tray 74.

  Note that the surface of the photoconductor 26 after the toner image transfer process is completed is made up of residual toner, paper dust, and the like by a cleaning blade 56 disposed obliquely above the photoconductor 26 every time the photoconductor 26 rotates once. Is removed, and is prepared for the next image forming step.

  As shown in FIG. 9, a charging roll 20 is disposed beside the photoconductor 26 so as to be in contact with the photoconductor 26. The charging roll 20 is rotatably supported. The cleaning roll 10 of the charging roll 20 is in contact with the side of the charging roll 20 opposite to the photoreceptor 26. As described above, in the cleaning roll 10, the elastic layer has a silicon-based oil-containing region containing silicon-based oil and a silicon-based oil-free region not containing silicon-based oil in the surface direction (circumferential direction). It is supported rotatably.

  The charging roll 10 is pressed against the photosensitive member 26 by applying a predetermined load F to both ends of the conductive core material, and is elastically deformed along the peripheral surface of the charging layer to form a nip portion. Further, the cleaning roll 10 is pressed against the charging roll 20 by applying a predetermined load F ′ to both ends of the core material, and the elastic layer is elastically deformed along the peripheral surface of the charging roll 20 to form a nip portion. The bending of the charging roll 20 is suppressed, and the axial nip uniformity between the charging roll 20 and the photoreceptor 26 is maintained.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Example 1>
(Production of cleaning roll)
After processing a foamed urethane sheet (Enoac Corporation, EPM70, polyether polyurethane) made of polyether polyol as a material and containing a silicon-based foam stabilizer into a predetermined size, a hole is made in the sheet, A core material having an outer diameter of φ6 mm, to which an adhesive was applied, was inserted into the hole and bonded by heating. After cooling, a portion of the circumferential direction (about 60 degrees around the core axis) is cut into a fan shape, and the cut portion is made of polyester polyol as a material without using a silicone foam stabilizer. The produced fan-shaped foamed urethane sheet (manufactured by Inoac Corporation, RSM55, polyester-based polyurethane) was attached and adhered by heating. After cooling, the cleaning roll is polished (with a shape as shown in FIG. 1, a silicon-based oil-containing region (the area of the cleaning surface is about 83% of the entire area)) and a silicon-based oil-free region (the cleaning surface area is about 17% of the entire area). %) In the surface direction). The cleaning roll was prepared so that the outer diameter was 10 mm, the thickness was 2 mm, and the length was 320 mm.

(Preparation of charging roll)
[Formation of elastic layer]
The following mixture was kneaded with an open roll, coated on the surface of a conductive core material made of SUS416 with a diameter of 6 mm in a cylindrical shape with a thickness of 3 mm, and put into a cylindrical mold with an inner diameter of 18.0 mm. After vulcanization at 30 ° C. for 30 minutes and taking out from the mold, polishing was performed to obtain a cylindrical conductive elastic layer.
Rubber material (epichlorohydrin-ethylene oxide-allylglycidyl ether copolymer rubber, Gechron 3106: manufactured by Nippon Zeon Co., Ltd.) 100 parts by mass Conductive agent (carbon black, Asahi Thermal: manufactured by Asahi Carbon Co., Ltd.) 25 parts by mass Conductive agent (Ketjen Black EC: Lion 8 parts by weight Ionic conductive agent (lithium perchlorate) 1 part by weight Vulcanizing agent (sulfur, 200 mesh: manufactured by Tsurumi Chemical Co., Ltd.) 1 part by weight Vulcanization accelerator (Noxeller DM: Ouchi Shinsei Chemical Industry Co., Ltd.) 2.0 parts by mass Vulcanization accelerator (Noxeller TT: Ouchi Shinsei Chemical Co., Ltd.) 0.5 parts by mass

[Formation of surface layer]
A dispersion obtained by dispersing the following mixture in a bead mill is diluted with methanol, dip-coated on the surface of the conductive elastic layer, and then heated and dried at 140 ° C. for 15 minutes to form a surface layer having a thickness of 4 μm. Thus, a charging roll was obtained.
Polymer material (copolymerized nylon, Alamine CM8000: manufactured by Toray Industries, Inc.) 100 parts by mass Conductive agent (antimony-doped tin oxide, SN-100P: manufactured by Ishihara Sangyo Co., Ltd.) 30 parts by mass Solvent (methanol) 500 parts by mass Solvent (butanol) 240 Parts by mass

<Example 2>
Thickness of foamed urethane sheet (Enoac Corporation, EPM70, polyether polyurethane) containing the silicon foam stabilizer used in Example 1 on the surface of an Al substrate having a thickness of 1 mm, a length of 320 mm and a width of 50 mm. A foamed urethane sheet (3 mm, length 320 mm × width 35 mm) is bonded, and the remaining part of the Al substrate surface is made of the foamed urethane sheet (without using the silicon-based foam stabilizer used in Example 1). (Inoac Corporation, RSM55, polyester polyurethane) Thickness 3mm, length 320mm x width 15mm, bonded to a cleaning pad (as shown in Fig. 3, silicon oil-containing region (cleaning) The area of the surface is about 70% of the whole) and the area not containing silicon oil (the area of the cleaning surface is about 30% of the whole) It was prepared having the direction). The cleaning pad was manufactured to have a thickness of 3 mm (excluding the thickness of the Al substrate) and a length of 320 mm × width 50 mm.

<Comparative Example 1>
(Production of cleaning roll)
As a cleaning roll, a foamed urethane sheet made of polyether polyol and containing a silicon foam stabilizer (Enoac Corporation, EPM70) is processed to a predetermined size, then a hole is made in the sheet and bonded to the hole A core material with an outer diameter of φ6 mm coated with an agent was inserted and bonded by heating. After cooling, a cleaning roll was prepared by polishing. The cleaning roll was prepared so that the outer diameter was 10 mm, the thickness was 2 mm, and the length was 320 mm.

<Comparative example 2>
(Production of cleaning roll)
A cleaning roll was prepared in the same manner as in Comparative Example 1 except that the foamed urethane sheet was made of polyester polyol and did not contain a silicon foam stabilizer.

<Evaluation>
(Image quality evaluation after long-term storage: new)
The color copying machine DocuCenter Color 400CP (manufactured by Fuji Xerox Co., Ltd.) modified so that the cleaning roll of the charging roll can be attached is mounted with the cleaning roll or the cleaning pad and the charging roll prepared in Examples 1 and 2 and Comparative Examples 1 and 2, respectively. did. A process cartridge equipped with a cleaning roll or cleaning pad and a charging roll is left in a 40 ° C / 95RH% environment for one month, then half-tone image quality evaluation is performed using the DocuCenter Color 400CP, and image quality defects after long-term storage are determined according to the following criteria. did.

(Cleanability evaluation: after long-term storage)
After evaluating the image quality defect, a printing test of 10,000 sheets of A4 paper was performed, and then it was determined whether there was any density unevenness due to uneven cleaning of the charging roll with halftone image quality based on the following criteria.

(Cleanability evaluation: new)
A printing test of 10,000 sheets of A4 paper was performed using a process cartridge equipped with a separate cleaning roll or cleaning pad and charging roll. In the image quality evaluation, whether or not there was uneven density due to uneven cleaning of the charging roll in the halftone image after 10,000 sheets was determined according to the following criteria.

(Image quality defect evaluation after long-term storage: Print test product)
Further, after the halftone image quality evaluation, the process cartridge was taken out from the DocuCenter Color 400CP, left in a 30 ° C./75 RH% environment for 2 weeks, and then halftone image quality evaluation was performed again to determine whether or not density unevenness occurred.

  In the above evaluation, when the image quality defect evaluation after long-term storage in Examples 1 and 2 is performed, the layer where the cleaning roll or the cleaning pad is in contact with the charging roll becomes a layer (RSM55) made of polyester-based polyurethane. Adjusted.

(Image quality defect / cleaning criteria)
○: Density unevenness on the image quality has not occurred ×: Density unevenness on the image quality is minor XX: Density unevenness on the image quality has occurred

  The evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

  From this result, it was possible to prevent contamination of the charging roll of the silicone foam stabilizer contained in the urethane using the polyether polyol while preventing deterioration of the cleaning property due to hydrolysis of the urethane using the polyester polyol. . Thus, by using the process cartridge having the cleaning roll or cleaning pad of the embodiment, the charging roll is contaminated even when stored for a long time in contact with the charging roll while maintaining the cleaning property of the charging roll. The occurrence of image quality defects such as density unevenness was suppressed.

  DESCRIPTION OF SYMBOLS 1 Charging device, 3 Process cartridge, 5 Image forming apparatus, 10 Cleaning roll, 11 Cleaning pad, 12 Core material, 14 Silicone oil containing area | region, 16 Silicone oil non-containing area | region, 18 Elastic layer, 20 Charging roll, 22 Conductivity Core material, 24 charged layer, 26 photoconductor, 28 coil spring, 30 bearing, 52 developing roll, 54 transfer roll, 56 cleaning blade, 58 exposure device, 60 image light (exposure), 62 recording paper, 64Y, 64M, 64C , 64K cartridge, 66Y, 66M, 66C, 66K developer, 68 paper transport belt, 70 fixing device, 72 discharge roll, 74 discharge tray, 76 paper transport path, 78 transport roll.

Claims (6)

  A charging member cleaning member comprising an elastic layer having a region including at least one silicon-based oil and a region not including at least one silicon-based oil in a surface direction. A core material,
A cylindrical elastic layer formed on the outer periphery of the core material, the cylindrical elastic layer having a region including at least one silicon-based oil and a region not including at least one silicon-based oil in the circumferential direction;
A charging member cleaning member comprising:   The charging member cleaning member according to claim 1, wherein the region not including the silicon-based oil includes a polyester-based polyurethane.   A charging member and the charging member cleaning member according to any one of claims 1 to 3, wherein the charging member is in contact with a region of the charging member cleaning member that does not contain silicon-based oil when the charging member is not in operation. Or a charging device characterized by facing each other.   A process cartridge comprising an image carrier and the charging device according to claim 4.   5. The image carrier, the charging device according to claim 4, a latent image forming unit that forms a latent image on the surface of the image carrier, and the latent image formed on the surface of the image carrier is developed with toner. An image forming apparatus comprising: a developing unit that forms a toner image; and a transfer unit that transfers the toner image formed on the surface of the image holding member to a transfer target.

Images