JP2009244667A - Electrifying member, process cartridge and electrophotographic equipment using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrifying member capable of obtaining a favorable image even at the end of endurance by suppressing adhesion of insulating particulates to the electrifying member and allowing uniform electrification of a photoreceptor throughout a long period of time. <P>SOLUTION: The electrifying member has a support member and a conductive coating layer. The conductive coating layer contains matrix resin containing either type or more selected from thermoplastic elastomer and thermoplastic resin, and resin particles with a mean particle diameter of ≥3 μm and ≤30 μm. A difference between a solubility parameter of the matrix resin and a solubility parameter of the resin particles is ≥1.5 and ≤3.0 in absolute value, and a value of a ten point average roughness Rz of a surface is within a range of ≥2.5 μm and ≤7.5 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a charging member, a process cartridge and an electrophotographic apparatus using the charging member, and more particularly to a charging member that contacts and charges an electrophotographic photosensitive member.

  In an electrophotographic apparatus such as a copying machine or a laser printer, an electrostatic latent image is formed by uniformly charging the surface of a photosensitive member and exposing through an image, and a toner image obtained by developing the electrostatic latent image is obtained. An image is formed by transferring to a recording material. In order to uniformly charge the surface of the photoreceptor in this way, a charging roller that contacts the surface of the photoreceptor and charges the surface is used. As this type of charging roller, a conductive elastic layer made of foam is formed on the shaft core, and this is inserted into a seamless tube to form a surface layer, thereby forming a smooth surface on the surface of the photoreceptor. A device that enables uniform charging is known (Patent Document 1).

  In recent years, from the viewpoints of space saving, energy saving, etc., in addition to requests for miniaturization and weight reduction of electrophotographic apparatuses, further high speed, high image quality, and high reliability are required. The charging roller is required to maintain uniform charging of the photosensitive member particularly for a long period of time. In a toner cartridge equipped with a charging roller, the charging roller charges the photoconductor to a constant charge from the first sheet until toner is consumed and the last image is formed, and a stable image is always formed. It is required to do. One of the main factors that deteriorate the charging property of the charging roller is an insulating component such as an additive component contained in the toner, paper dust from the recording material, and a lubricant that smoothly drives each part in the cartridge. May adhere to the surface of the charging roller through the photosensitive member. As a measure for suppressing the adhesion of such insulating components, a method using a fluororesin material that is considered to have good releasability for forming the surface of the charging roller, or a method using a polyacrylonitrile material (Patent Document 2) Has been proposed (Patent Document 3).

However, even when these measures are taken, for example, insulating fine powder such as silica as a toner additive component gradually adheres and accumulates on the surface of the charging roller, and the uniform contact with the photosensitive member is obstructed. Inconsistency occurs, and there is a problem in high-speed and high-quality image formation.
US Pat. No. 4,967,231 JP-A-7-042728 JP-A-9-236969

  An object of the present invention is to provide a charging member that suppresses the adhesion of these insulating fine particles to the charging member, enables uniform charging of the photoreceptor over a long period of time, and obtains a good image even at the end of the durability. There is to do.

  The present inventors have investigated the cause of the fine powder adhering to the surface of the charging member. As a cause, it was considered that the fine powder was crushed on the contact surface between the photosensitive member and the charging member, and decreased and deposited on the softer charging member. Therefore, the charging member surface is roughened to form an appropriate gap on the contact surface between the charging member and the photosensitive member, and to suppress crushing of the insulating fine powder between the charging member and the photosensitive member. It was thought that the decline to the can be suppressed. Therefore, the surface layer contains resin particles having a particle diameter in a specific range, the solubility parameter (also referred to as SP value) of the matrix resin and the resin particles has a specific relationship, and the surface roughness is in a specific range. As a result, it was found that adhesion of fine powder to the charging member can be suppressed. Based on this knowledge, the present invention has been completed.

That is, the present invention provides a charging member having a support member and a conductive coating layer.
The conductive coating layer contains a matrix resin containing any one or more selected from thermoplastic elastomers and thermoplastic resins, and resin particles having an average particle size of 3 μm or more and 30 μm or less,
The difference between the solubility parameter of the matrix resin and the solubility parameter of the resin particles is 1.5 to 3.0 in absolute value, and the value of the 10-point average roughness Rz of the surface is 2.5 μm to 7.5 μm The present invention relates to a charging member having the following range.

Further, the present invention provides a process cartridge that is detachably provided in an electrophotographic apparatus and has any two or more selected from a photosensitive member that carries an electrostatic latent image, a charging member, a developing unit, and a cleaning unit.
The present invention relates to a process cartridge, wherein the charging member is the charging member.

  The present invention also provides an electrophotographic apparatus having a photosensitive member carrying an electrostatic latent image, a charging member, a developing unit, a transfer unit, and a cleaning unit, wherein the charging member is the charging member. The present invention relates to an electrophotographic apparatus.

  The charging member of the present invention suppresses the adhesion of insulating fine particles to the charging member, makes it possible to uniformly charge the photosensitive member over a long period of time, and a good image can be obtained even at the end of durability.

  The charging member of the present invention has a support member and a conductive coating layer. And an electroconductive coating layer contains the matrix resin containing any 1 or more types chosen from a thermoplastic elastomer and a thermoplastic resin, and the resin particle whose average particle diameter is 3 micrometers or more and 30 micrometers or less. The difference between the solubility parameter of the matrix resin and the solubility parameter of the resin particles is 1.5 to 3.0 in absolute value, and the value of the 10-point average roughness Rz of the surface is 2.5 to 7.5 μm It is the range of these.

[Support member]
The supporting member in the charging member of the present invention is not particularly limited as long as it is conductive, supports the upper conductive coating layer, and has a strength capable of charging the photosensitive member. As the support member, one having an elastic layer on the support is preferable because it can form a nip and contact with the photoconductor to uniformly charge the photoconductor. Specific examples of the material for the support include metals such as iron, copper, and stainless steel, carbon dispersion resins, metals, and metal oxide dispersion resins. The shape of the support may be a plate shape, but it is preferable that the charging member is a roller shape so that uniform contact with the photoreceptor is facilitated, so that it is cylindrical or columnar. Examples of the cylindrical and columnar supports include those having an outer diameter of 7 mm to 16 mm, for example. Specific examples of the material for the elastic layer provided on the support include the following. Rubbers such as chloroprene rubber, isoprene rubber, EPDM rubber, polyurethane rubber, epoxy rubber, or butyl rubber, and resins such as polystyrene butadiene, polyurethane, polyester, or polyethylene vinyl acetate.

  The elastic layer may further contain a conductive agent such as carbon black, metal and metal oxide particles. The elastic layer may be composed of a plurality of layers.

Such an elastic layer preferably has a thickness of 0.5 mm to 5 mm, for example. The elastic layer preferably has a resistance value in the range of, for example, a volume resistance of about 10 ¹ Ω · cm to 10 ⁹ Ω · cm.

[Conductive coating layer]
[Matrix resin]
The conductive coating layer of the charging member of the present invention contains any one or more selected from thermoplastic elastomers and thermoplastic resins. Specific examples of the thermoplastic elastomer forming the matrix resin include the following. Polyamides such as polyester, polyurethane, nylon 6, nylon 66, nylon 11 and nylon 12, styrene ethylene butyl, ethylene butyl, nitrile butadiene rubber, chlorosulfonated polyethylene, chlorinated polyethylene. 1,2-polybutadiene, styrene-butadiene-styrene (SBS), styrene-butadiene-styrene water additive (SEBS), and the like.

  Specific examples of the thermoplastic resin forming the matrix resin include the following. Saturated polyester such as polyethylene, polypropylene, polyethylene terephthalate (PET), or polybutylene terephthalate (PBT), polyether, polyamide, polycarbonate, polyacetal, acrylonitrile butadiene styrene, polystyrene. High impact polystyrene (HIPS), polyurethane, polyphenylene oxide, polyvinyl acetate, polyvinylidene fluoride, polytetrafluoroethylene. Styrenic and acrylic resins such as acrylonitrile-butadiene-styrene resin (ABS), acrylonitrile-ethylene / propylene rubber-styrene resin (AES) or acrylonitrile-acrylic rubber-styrene resin (AAS). Pomopolymers and copolymers such as polyvinyl chloride and polyvinylidene chloride.

  The thermoplastic elastomer and the thermoplastic resin can be used alone or in combination of two or more, but the matrix resin preferably contains 50% by mass or more of the thermoplastic elastomer. If the content of the thermoplastic elastomer is 50% by mass or more, the conductive coating layer can be made rubbery, and adverse effects such as the occurrence of cracks on the surface can be suppressed.

[Resin particles]
The resin particles contained in the conductive coating layer have a heat resistance that does not melt or deform in the temperature range near 200 ° C., for example, during kneading or extrusion molding with the thermoplastic material when forming the conductive coating layer. It must have decomposition resistance and reaction resistance. The material of the resin particles is appropriately selected in relation to the matrix resin. Specific examples include acrylic particles, urethane particles, polymethyl methacrylate particles, polybutyl methacrylate particles, and polystyrene particles.

  The average particle diameter of the resin particles is 3 μm or more and 30 μm or less, and more preferably 5 μm or more and 15 μm or less. If the average particle diameter of the resin particles is 3 μm or more, an appropriate roughness can be formed on the surface of the conductive coating layer, and adhesion of insulating fine powder can be suppressed. If the average particle size is 30 μm or less, a sufficient surface roughness can be formed, and an excessive discharge due to an excessive surface roughness can be prevented from causing an image defect.

  The average particle diameter of the resin particles can be measured by a measuring method such as a dynamic light scattering method, a laser diffraction method, or a centrifugal sedimentation method, and among these, the laser diffraction method is preferable. As a measured value by the laser diffraction method, a measured value obtained by measuring with a SALD manufactured by SIMAZU using a light diffraction phenomenon and a Mie scattering phenomenon can be adopted.

  The resin particles are preferably contained in the conductive coating layer in the range of 5 to 50 parts by mass with respect to 100 parts by mass of the matrix resin. By containing the resin particles in this range, it becomes easy to set the value of the surface 10-point average roughness Rz of the conductive coating layer to a range of 2.5 μm or more and 7.5 μm or less.

  The average 10-point surface roughness Rz of the conductive coating layer is the average of the peak height from the highest peak to the fifth peak in the roughness curve, and the valley depth from the deepest valley bottom to the fifth deepest, as per JIS standards. It is indicated by the sum of The roughness measurement in this case measures the roughness in the longitudinal direction of the roller. A surfcom manufactured by Tokyo Seimitsu Co., Ltd. can be used as a measuring device. The measurement conditions are a measurement speed of 0.5mm / s and a measurement length of 2.5mm. The measurement points are the center in the longitudinal direction of the roller, 90mm from the center to the left and right, and 6 points in total, 0 and 180 degrees in the circumferential direction. The average value can be adopted.

[SP value of matrix resin and resin particles]
The SP value of the matrix resin and the SP value of the resin particles have a difference of 1.5 to 3.0 in absolute value. The SP value is an SP value (Solubility Parameter) calculated by the Fedors equation. Specifically, the SP value is a value calculated from the following Fedors equation described in Polymer Engineering and Science, 14, (2), 147 (1974), and Δe1 and Δv1 data summarized in the document Can be adopted.

δ = √ [Σ (Δe1) / Σ (Δv1)]
In the formula, Δe1 represents the cohesive energy per unit functional group, Δv1 represents the molecular volume per unit functional group, and the unit of δ is (cal / cm ³ ) ^1/2 . The SP value of the copolymer is calculated by proportional distribution of the mass ratio of the SP values of the monomer units, assuming that the addition rule is established, and this is used as the SP value.

  If the difference in SP value between the matrix resin and the resin particles is 1.5 or more in absolute value, adhesion of insulating fine particles to the conductive coating layer can be suppressed. Further, if the difference between these SP values is 3.0 or less in absolute value, the resin particles can be sufficiently dispersed in the matrix resin, and a conductive coating layer having a uniform surface roughness can be obtained, It enables uniform charging of the photoreceptor.

[Conductivity]
The conductive coating layer preferably has a resistance value of 1 × 10 ⁶ Ω · cm or more and 1 × 10 ¹¹ Ω · cm or less. If the resistance value of the conductive coating layer is 1 × 10 ⁶ Ω · cm or more, the photoconductor can be appropriately charged. If the resistance value is 1 × 10 ¹¹ Ω · cm or less, the charging member is charged when the photoconductor is charged. It is possible to prevent the resistance from increasing and the durability from decreasing. In order to provide such a resistance value, a method in which a conductive agent is contained in the conductive coating layer can be employed. As the conductive agent, metal oxides such as carbon black, graphite, titanium oxide, and lead oxide can be used, but carbon black is preferable because it can impart appropriate conductivity. As carbon black, specifically, the following commercially available products can be applied. Ketjen Black (manufactured by Lion Akzo), Printex, Special Black, Color Black (manufactured by Degussa), BLACK PEARLS (manufactured by Cabot), Asahi Carbon (manufactured by Asahi Carbon), Mitsubishi Carbon (manufactured by Mitsubishi Chemical). Denka Black (manufactured by Denki Kagaku Kogyo), Seest, Toka Black (manufactured by Tokai Carbon Co., Ltd.) These can be used alone or in combination of two or more.

  The content of carbon black in the conductive coating layer is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 40% by mass or less. When the content of carbon black is 10% by mass or more, it is possible to suppress an increase in resistance during charging of the photoreceptor and to suppress a decrease in durability of the charging member. On the other hand, if the content of carbon black is 60% by mass or less, the conductive resin layer can be prevented from having high hardness.

  The conductive coating layer can contain an anti-aging agent, a softening agent, a plasticizer, a reinforcing agent, a filler, and the like as long as the function of the substance is not impaired as required.

[Formation of conductive coating layer]
The conductive coating layer may be formed by any method such as extrusion molding or cast molding. However, additives such as matrix resin, resin particles, and carbon black constituting the conductive coating layer are kneaded into a tube shape. It is preferable to use the formed seamless tube. Specifically, additives such as matrix resin, resin particles, and carbon black are kneaded to form pellets, which are molded into a tube shape using an extrusion molding machine to obtain a seamless tube. A support member is inserted into the obtained seamless tube to form a conductive coating layer. As a method of covering the support member with the seamless tube, there is a method in which the seamless tube has an inner diameter larger than the outer diameter of the support member, and the seamless tube is contracted by physical or chemical means, for example, heat, to be in close contact with the support member. be able to. Further, there can be mentioned a method in which the inner diameter of the seamless tube is made smaller than the outer diameter of the support member, the seamless tube is expanded by physical or chemical means such as air pressure, and the support member is press-fitted and brought into close contact with the support member. The seamrel tube can also be formed as a multilayer structure including, for example, an outer layer containing a matrix resin and resin particles and an inner layer containing a matrix resin and other additives such as carbon black. Conventionally, it has been difficult to stably form a conductive coating layer having a uniform resistance value in the above range, but by using a seamless tube as described above, a conductive layer having extremely excellent characteristics can be obtained. The stable production of the conductive coating layer can be performed.

  Although the thickness of the said conductive coating layer does not have a restriction | limiting in particular, For example, it can be 100 micrometers or more and 600 micrometers or less.

  As an example of the charging member of the present invention, a charging member having a support member and a seamless tube is particularly excellent in manufacturing stability, and can stably produce a medium resistance region, which has been conventionally difficult to produce stably.

  As an example of the charging member of the present invention, the charging roller shown in FIG. 1 can be exemplified. The charging roller shown in FIG. 1 has an elastic layer 2 and a conductive coating layer 3 in this order on a conductive shaft support 1, and the conductive coating layer 3 includes a conductive agent-containing layer 3a and a resin particle-containing layer. 3b. When the conductive coating layer has a two-layer structure of a layer containing a conductive agent and a layer containing resin particles, the surface roughness can be easily controlled.

  The process cartridge of the present invention is a process cartridge which is detachably provided in an electrophotographic apparatus and has any two or more selected from a photoconductor that carries an electrostatic latent image, a charging member, a developing unit, and a cleaning unit. A member is provided.

  An example of the process cartridge of the present invention is shown in FIG. The process cartridge shown in FIG. 2 is mainly provided with a photoreceptor 5 that carries an electrostatic latent image that can rotate in the direction of the arrow. A developing roller 4 that is a developing means and a charging roller 8 that is a charging member are arranged opposite to the photosensitive member, and a developer application roller 6 is provided in a developer container 9 that stores the developer. A developing blade 7 is integrated with an end of the agent container 9.

  The electrophotographic apparatus of the present invention is an electrophotographic apparatus having a photosensitive member carrying an electrostatic latent image, a charging member, a developing unit, a transfer unit, and a cleaning unit, wherein the charging member is the charging member. It is characterized by.

  As an example of the electrophotographic apparatus of the present invention, a tandem color electrophotographic apparatus shown in FIG. 3 can be given. The electrophotographic apparatus shown in the schematic configuration diagram of FIG. 3 includes image forming units 10Y, 10M, 10C, and 10K that are provided for each color toner such as yellow toner, magenta toner, cyan toner, and black toner. The process cartridge can be applied to each image forming unit. The electrophotographic apparatus is provided with exposure means (not shown) for forming an electrostatic latent image on the photosensitive member uniformly charged by the charging roller 8. Furthermore, a transfer roller 12 serving as a transfer unit provided opposite to the photoreceptor of each image forming unit via a conveyance belt 10 that conveys the recording material, a fixing device 13 that fixes an image on the recording material, and the like are provided. It is done. In addition, cleaning means (not shown) for removing the developer remaining on the photoconductor after transfer is provided.

  Image formation by such an electrophotographic apparatus is performed as follows.

  The photoreceptor 5 is uniformly charged by the charging roller 8. Next, a latent image is formed on the photoreceptor by exposure means. A developer is fed to the surface of the developing roller 4 by the developer application roller 6, and a developer thin film having a uniform thickness is formed on the surface of the developing roller 4 by the developing blade 7. In this state, the developing roller and the photosensitive member are brought into contact with each other for development. The toner image formed on the photosensitive member is pressed by the transfer roller from the back surface of the recording material P conveyed by the conveyance belt 10 and moves to the recording material by the transfer bias charge applied to the transfer roller. Since the conveying belt moves in synchronization with each image forming unit and conveys the recording material, the toner image formed in each image forming unit is transferred onto the recording material in a superimposed manner. The superimposed toner image on the recording material is fixed on the recording material by heat and pressure in the fixing device, thereby completing the image formation.

  In the process cartridge of the present invention, in addition to the above, the transfer roller for transferring the toner image on the photosensitive member to the transfer material, the cleaning member, etc. are exchanged together with the above member or one or more of the above members. May be provided integrally.

  The charging member, process cartridge, and electrophotographic apparatus of the present invention will be specifically described below in detail, but the technical scope of the present invention is not limited to these.

[Example 1]
The following materials were melt-kneaded at 20 to 220 ° C. using a pressure kneader, then cooled and pulverized by a pulverizer, and pellets for outer layers were granulated at 140 ° C. to 200 ° C. using a single screw extruder.
100 parts by mass of olefin elastomer with SP value of 8.0 as thermoplastic elastomer, 10.0 parts by mass of resin particles as urethane particles, 20 parts by mass of urethane resin particles with an average particle diameter of 8 μm, 60 parts by mass of carbon black as an additive, calcium stearate 1 Further, the following materials were kneaded at 180 ° C. for 15 minutes using a pressure kneader, cooled and pulverized, and pellets for the inner layer were granulated using a single screw extruder.
Thermoplastic polyurethane elastomer 100 parts by weight Ketjen black 16 parts by weight Magnesium oxide 10 parts by weight Calcium stearate 1 part by weight Using the above two types of pellets, a die having an inner diameter of 16.5 mm and a point having an outer diameter of 18.5 mm After extrusion with a layer extruder, sizing and cooling processes were performed. Thereafter, a two-layer seamless tube having an inner diameter of 11.1 mm, an outer layer thickness of 100 μm, and an inner layer thickness of 400 μm was formed.

  An EPDM foamed elastic rubber layer compounded with carbon is formed on a core metal having an outer diameter of 6.0 mm and a length of 259 mm, and polished to have an end outer diameter of 11.20 mm, a central outer diameter of 11.40 mm, and a length of 230 mm. A support member having a foamed elastic rubber layer was obtained.

  A seamless tube was fitted into the support member by air pressure and brought into close contact with the pressure member to obtain a charging roller.

  Rz of the obtained charging roller was 4.5 μm.

[Example 2]
As the outer layer pellets, a fluoroelastomer having an SP value of 6.5 as a thermoplastic elastomer, and 50 parts by mass of PMMA resin particles having an SP value of 9.5 and an average particle diameter of 30 μm were used as resin particles. 30 parts by mass of carbon black was used as a conductive agent. Other than that was carried out similarly to Example 1, and obtained the charging roller. Rz of the charging roller was 7.2 μm.

[Example 3]
As an outer layer pellet, a thermoplastic elastomer having an SP value of 8.0 and an AS resin mixed at a mass ratio of 6: 4 was used. As resin particles, 10 parts by mass of urethane resin particles having an SP value of 10.0 and an average particle diameter of 3 μm were used. Other than that was carried out similarly to Example 1, and obtained the charging roller. Rz of the charging roller was 2.8 μm.

[Comparative Example 1]
As the outer layer pellet, a fluoroelastomer having an SP value of 6.5 was used as the thermoplastic elastomer, and 5 parts by mass of urethane resin particles having an SP value of 10.0 and an average particle diameter of 5 μm were used as the resin particles. 30 parts by mass of carbon black was used as a conductive agent. Other than that was carried out similarly to Example 1, and created the charging roller. When the seamless tube was formed, the surface of the tube became rough, but a charging roller was created as it was. The Rz of the charging roller could not be measured.

[Comparative Example 2]
As the outer layer pellet, an olefin elastomer having an SP value of 8.0 was used as the thermoplastic elastomer. As resin particles, 10 parts by mass of urethane resin particles having an SP value of 10.0 and an average particle diameter of 2.5 μm were used. Other than that was carried out similarly to Example 1, and obtained the charging roller. Rz of the charging roller was 2.1 μm.

[Comparative Example 3]
As the outer layer pellet, an olefin elastomer having an SP value of 8.0 was used as the thermoplastic elastomer. A charging roller was obtained in the same manner as in Example 1 except that the resin particles were not used. Rz of the charging roller was 1.9 μm.

[Comparative Example 4]
As the outer layer pellet, an olefin elastomer having an SP value of 8.0 was used as the thermoplastic elastomer. As resin particles, 20 parts by mass of styrene resin particles having an SP value of 9.0 and an average particle diameter of 7 μm were used. Other than that was carried out similarly to Example 1, and obtained the charging roller. The charging roller Rz was 3.6 μm.

[Comparative Example 5]
As the outer layer pellet, an olefin elastomer having an SP value of 8.0 was used as the thermoplastic elastomer. As the resin particles, 30 parts by mass of PMMA resin particles having an SP value of 9.5 and an average particle diameter of 40 μm were used. Other than that was carried out similarly to Example 1, and obtained the charging roller. Rz of the charging roller was 10.5 μm.

[Electrophotographic process cartridge]
The obtained charging roller was assembled in a process cartridge shown in FIG. 2 and mounted on an electrophotographic apparatus. A continuous test of 20,000 halftone image patterns was performed and a durability test was performed. For the initial image and the image after output of 20,000 sheets, image evaluation was performed according to the following criteria depending on the presence or absence of image defects such as white spots, black spots, and black stripes.
(Double-circle): Image defect is not recognized at all.
○: Almost no image defect is observed.
Δ: Image defects are seen in the roller cycle.
X: Many image defects are seen.

  In the charging roller according to the example, good images were obtained at the initial stage even after outputting 20,000 sheets, and the charging roller taken out from the cartridge was only slightly stained. On the other hand, the roller of Comparative Example 1 had many white spots due to poor charging from the beginning, and the roller of Comparative Example 5 had black spots caused by abnormal discharge from the beginning, so the evaluation was stopped here. The charging rollers of Comparative Examples 2, 3, 4, and 6 generated white spots due to poor charging after outputting 20,000 sheets. When the charging roller was taken out of the cartridge, a large amount of silica fine particles that were thought to be derived from the toner external additive were adhered.

  From the above results, it is clear that in the charging member of the present invention, deposits on the charging member can be reduced, and a good image can be obtained over a long period of time.

It is sectional drawing which shows an example of the charging member of this invention. It is a schematic block diagram which shows an example of the process cartridge of this invention. It is a schematic block diagram which shows an example of the electrophotographic apparatus of this invention.

Explanation of symbols

1 Support (support member)
2 Elastic layer (support member)
3a Conductive agent-containing layer (conductive coating layer)
3b Resin particle-containing layer (conductive coating layer)
4 Development roller (development means)
5 Photosensitive member 6 Application roller (developing means)
7 Development blade (development means)
8 Charging roller (charging member)
9 Developer container (developing means)
12 Transfer roller (transfer means)
P Recording material

Claims (7)

In a charging member having a support member and a conductive coating layer,
The conductive coating layer contains a matrix resin containing at least one selected from thermoplastic elastomers and thermoplastic resins, and resin particles having an average particle size of 3 μm to 30 μm, and the solubility parameter of the matrix resin The absolute value of the difference between the solubility parameter of the resin particle and the resin particle is 1.5 or more and 3.0 or less, and the 10-point average roughness Rz of the surface is in the range of 2.5 μm or more and 7.5 μm or less. A charging member.   The charging member according to claim 1, wherein the conductive coating layer contains a thermoplastic elastomer in an amount of 50% by mass or more in the matrix resin.   The charging member according to claim 1 or 2, wherein the conductive coating layer contains resin particles in a range of 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the matrix resin.   The charging member according to claim 1, wherein the conductive coating layer is formed using a seamless tube.   The charging member according to claim 1, wherein the conductive coating layer contains carbon black.   6. A process cartridge which is detachably provided in an electrophotographic apparatus and has any two or more selected from a photoconductor that carries an electrostatic latent image, a charging member, a developing unit, and a cleaning unit. A process cartridge which is any one of the charging members.   6. A charging member according to claim 1, wherein the charging member is an electrophotographic apparatus having a photosensitive member carrying an electrostatic latent image, a charging member, a developing unit, a transfer unit, and a cleaning unit. An electrophotographic apparatus characterized by that.

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