Cleaning blade, process cartridge, and image forming apparatus

Abstract

To provide a cleaning blade that can prevent an increase in torque even immediately after the start of use, and can provide good cleaning properties.SOLUTION: A cleaning blade has an elastic member that is in contact with a surface of a member to be cleaned to remove a residue on the surface of the member to be cleaned. The cleaning blade has a coating layer on a blade leading end surface in contact with the member to be cleaned, and does not have the coating layer on a blade lower surface orthogonal to the blade leading end surface. The coating layer is present in at least a portion where the cleaning blade is in contact with the member to be cleaned.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a cleaning blade, a process cartridge, and an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art In conventional electrophotographic image forming apparatuses, residual toner remaining on the surface of an image carrier after a toner image is transferred to a recording medium or an intermediate transfer member during image formation is removed by a cleaning means.

[0003] As the cleaning means, a cleaning blade is used because of its simple structure and excellent cleaning performance. The cleaning blade is usually composed of a blade base including an elastic member such as polyurethane rubber, and a support member. The base end of the blade base of the cleaning blade is supported by the support member, and the blade tip edge of the cleaning blade is pressed against the surface of the image carrier to intercept, scrape off, and remove the toner remaining on the surface of the image carrier.

[0004] In the cleaning means using the cleaning blade, the cleaning blade comes into contact with the image carrier, so friction occurs between the cleaning blade and the image carrier, and the torque, which is the force required to rotate the image carrier, increases, and the image carrier may stop. In addition, the rubbing between the cleaning blade and the image carrier may cause the contact portion between the image carrier surface and the cleaning blade (including the blade tip edge portion) to wear, causing the contact portion to turn over, and toner to slip through the turned over portion, resulting in poor cleaning.

[0005] When assembling the image forming apparatus and replacing the cleaning blade, a process (commonly known as touch-up) may be performed in which toner or a metal soap such as zinc stearate is applied around the edge of the blade tip where the cleaning blade contacts the image carrier surface, in order to increase the sliding property between the cleaning blade and the image carrier to prevent the cleaning blade from rolling up, and to reduce the torque to prevent the image carrier from stopping due to an increase in torque.

[0006] When toner or a metal soap such as zinc stearate is applied by the touch-up, toner gradually accumulates between the cleaning blade and the image carrier as the image forming apparatus operates, and when this state is reached, the behavior of the blade becomes stable, so the metal soap (touch-up agent) only needs to function until this state is reached.

[0007] However, conventional touch-up is often performed manually, which may result in variation in the amount of touch-up agent applied depending on the operator.Furthermore, conventional touch-up agents have a problem in that they are detached from the cleaning blade before the behavior of the cleaning blade becomes stable.

[0008] Furthermore, there is also a method in which a dispersion liquid in which fine particles are dispersed in a solvent is applied to the portion of the cleaning blade that comes into contact with the cleaning member, thereby distributing the fine particles at the portion of the cleaning blade that comes into contact with the cleaning member. However, since the adhesion of the fine particles to the cleaning blade is weak, the fine particles are easily detached from the cleaning blade, and before the behavior of the cleaning blade stabilizes, problems occur in that poor cleaning occurs due to curling of the cleaning blade and the torque of the image carrier increases.

[0009] Patent Document 1 describes coating the edge portion of the cleaning blade with a lubricant dispersion of a powder lubricant. Patent Document 2 describes the formation of a thin surface layer containing a solid lubricant at the site where the cleaning blade comes into contact. Patent Document 3 describes forming a coating layer on the edge surface of the cleaning blade, the coating layer being made of a resin of the same series as the binder resin contained in the photosensitive drum. Patent Document 4 describes that the contact portion of the cleaning blade has a modified portion formed by a curable composition. Patent Document 5 describes a method in which a lubricant dispersion liquid in which spherical fine particles of polymethyl methacrylate powder are dispersed in a fluorine-based inert liquid is dropped onto the edge of a cleaning blade to apply the polymethyl methacrylate powder to the cleaning blade. Summary of the Invention [Problem to be solved by the invention]

[0010] There is a trade-off between suppressing torque increase and obtaining good cleaning performance, and if the frictional force is reduced by smoothing the contact portion of the cleaning blade in order to suppress the torque increase, particles such as toner are more likely to slip through, and cleaning performance is likely to decrease. On the other hand, if the frictional force of the contact portion of the cleaning blade is increased by making the surface uneven in order to improve cleaning performance, the torque is more likely to increase. Therefore, it is difficult for the cleaning means to obtain good cleaning performance while suppressing the increase in torque.

[0011] An object of the present invention is to provide a cleaning blade capable of suppressing an increase in torque even immediately after the start of use and providing good cleaning performance. [Means for solving the problem]

[0012] In order to solve the above problem, one embodiment of the present invention is A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned to remove residues on the surface of the member to be cleaned, the cleaning blade has a coating layer on a blade tip surface that comes into contact with the member to be cleaned, and does not have the coating layer on a blade lower surface that is perpendicular to the blade tip surface; The coating layer provides a cleaning blade that is present at least in a portion where the cleaning blade contacts the member to be cleaned. Effect of the Invention

[0013] According to the present invention, it is possible to provide a cleaning blade that can suppress an increase in torque even immediately after the start of use and can provide good cleaning performance. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic cross-sectional view of an example of a state in which a cleaning blade according to an embodiment of the present invention is in contact with a surface of an image bearing member. [Diagram 2] FIG. 1 is a perspective view of a cleaning blade according to an embodiment of the present invention. [Diagram 3] 1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view of an example of an imaging unit in an image forming apparatus according to an embodiment of the present invention. [Diagram 5] 3A to 3C are schematic diagrams illustrating an example of a state in which a coating layer is formed on a cleaning blade according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the preferred embodiments.

[0016] (cleaning blade) The cleaning blade of the present invention is A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned to remove residues on the surface of the member to be cleaned, the cleaning blade has a coating layer on a blade tip surface that comes into contact with the member to be cleaned, and does not have the coating layer on a blade lower surface that is perpendicular to the blade tip surface; The coating layer is present at least in the portion of the cleaning blade that contacts the member to be cleaned. In this application, "perpendicular" means "intersecting within the range of 90°±20°." The term "blade tip surface" refers to one end surface of the circumferential side surface of the cleaning blade that is used as the tip of the cleaning blade. The blade tip surface abuts against the surface of the member to be cleaned. The "underside of the blade" refers to the surface of the cleaning blade that is perpendicular to the blade tip surface, and that faces the member to be cleaned and is located closest to the member to be cleaned when the cleaning blade contacts the surface of the member to be cleaned. The cleaning blade may further include other members as necessary. According to the present invention, it is possible to provide a cleaning blade that can suppress an increase in torque even immediately after the start of use and can provide good cleaning performance.

[0017] <Blade base of cleaning blade> The cleaning blade has a blade substrate, and the blade substrate includes the elastic member. The structure of the blade body is not particularly limited and may be appropriately selected depending on the purpose, and may include a single layer structure of the elastic member, or a laminate structure in which a plurality of the elastic members are laminated. The blade base preferably includes a laminated structure in which a plurality of elastic members are laminated, and more preferably includes a laminated structure in which a plurality of elastic members have different Martens hardness or JIS-A hardness.Moreover, the laminated structure is even more preferably an integrally molded laminated product in which a laminated structure in which two or more types of a plurality of elastic members have different Martens hardness or JIS-A hardness can be simultaneously achieved in terms of abrasion resistance and followability.

[0018] <<Elastic material>> The elastic member is not particularly limited in shape, material, size, structure, etc., and can be appropriately selected depending on the purpose. Examples of the shape of the elastic member include a flat plate, a strip, a sheet, etc. The size of the elastic member is not particularly limited, and can be appropriately selected depending on the size of the member to be cleaned. The material of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but materials containing polyurethane rubber, polyurethane elastomer, etc. are preferred because they tend to provide high elasticity.

[0019] The method for producing the elastic member is not particularly limited and can be appropriately selected depending on the purpose. For example, the elastic member can be produced by preparing a polyurethane prepolymer using a polyol compound and a polyisocyanate compound, adding a curing agent and, if necessary, a curing catalyst to the polyurethane prepolymer, crosslinking the polyurethane prepolymer in a specified mold, and then forming the post-crosslinked product in an oven into a sheet by centrifugal molding. The sheet is then left to stand at room temperature for aging, and then cut into a plate of specified dimensions.

[0020] The polyol compound is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyol compound include high molecular weight polyols and low molecular weight polyols. Examples of the high molecular weight polyol include polyester polyols which are condensates of alkylene glycols and aliphatic dibasic acids; polyester polyols such as polyester polyols of alkylene glycols and adipic acid, such as ethylene adipate ester polyol, butylene adipate ester polyol, hexylene adipate ester polyol, ethylene propylene adipate ester polyol, ethylene butylene adipate ester polyol, and ethylene neopentylene adipate ester polyol; polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone; polyether polyols such as poly(oxytetramethylene) glycol and poly(oxypropylene) glycol, etc. These may be used alone or in combination of two or more.

[0021] Examples of the low molecular weight polyol include dihydric alcohols such as 1,4-butanediol, ethylene glycol, neopentyl glycol, hydroquinone-bis(2-hydroxyethyl)ether, 3,3'-dichloro-4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenylmethane; and trihydric or higher polyhydric alcohols such as 1,1,1-trimethylolpropane, glycerin, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolethane, 1,1,1-tris(hydroxyethoxymethyl)propane, diglycerin, and pentaerythritol. These may be used alone or in combination of two or more.

[0022] The polyisocyanate compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methylene diphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5-diisocyanate (NDI), tetramethyl xylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), trimethylhexamethylene diisocyanate (TMDI), etc. These may be used alone or in combination of two or more.

[0023] The curing agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the curing agent include amines and alcohols. These may be used alone or in combination of two or more. The hardener is used, for example, to adjust the hardness of the elastic member.

[0024] The curing catalyst is not particularly limited and can be appropriately selected depending on the purpose. Examples of the curing catalyst include 2-methylimidazole and 1,2-dimethylimidazole. The content of the curing catalyst is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 0.5% by mass, and more preferably 0.05% by mass to 0.3% by mass, based on the total mass of the prepolymer and the curing agent.

[0025] -JIS-A hardness of elastic material- The JIS-A hardness of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 65 degrees to 83 degrees. When the JIS-A hardness is within the range of 65 degrees to 83 degrees, the blade line pressure is easily obtained in cleaning performance, the area of ​​the part in contact with the image carrier is not easily expanded, and cleaning defects are not easily caused. In addition, since it is not too hard, chipping is not easily caused.

[0026] The JIS-A hardness of the elastic member can be measured in accordance with JIS K6253, for example, using a micro rubber hardness meter (MD-1, manufactured by Kobunshi Keiki Co., Ltd.) in accordance with JIS K6253.

[0027] -Resilience of elastic materials- The resilience of the elastic member is not particularly limited and may be appropriately selected depending on the purpose, but the resilience according to JIS K6255 is preferably 36% to 73%, more preferably 52% to 73%, at 23° C. When the resilience according to JIS K6255 is 36% to 73% at 23° C., the flexibility of the entire elastic member is maintained in terms of cleaning performance, so that it can follow the vibration and roughness of the image carrier, cleaning defects are unlikely to occur, and the resilience of the driving torque does not become too strong, so that blade noise can be suppressed. Here, the resilience modulus of the elastic member at 23° C. in accordance with JIS K6255 standard can be measured, for example, by using a resilience tester (No. 221, manufactured by Toyo Seiki Seisakusho, Ltd.).

[0028] -Martens hardness (HM) of elastic material- The Martens hardness of the elastic member is 0.5 [N / mm 2 ] or more than 3[N / mm 2 ] or less, and 0.5 [N / mm 2 ] or more 2[N / mm 2 It is more preferable that the Martens hardness of the elastic member is 0.5 [N / mm 2 ] or more than 3[N / mm 2 ] or less, a sufficient sliding effect can be obtained.

[0029] The Martens hardness (HM) can be measured, for example, according to ISO 14577, using a nanoindenter (ENT-3100, manufactured by Elionix), by pressing a Berkovich indenter with a load of 1,000 μN for 10 seconds, holding the indenter in place for 5 seconds, and then removing the indenter at the same loading rate for 10 seconds. There are no particular limitations on the location where the Martens hardness of the elastic member is measured, but for ease of measurement, it is preferable to measure it at a position that is 20 μm from the ridge line at the tip of the blade when the elastic member, or a sheet or the like after molding the elastic member, is formed into a blade, and 4 to 6 points are measured at this position, and the median of the obtained Martens hardness values ​​can be used as the Martens hardness.

[0030] -Average thickness of elastic member- The average thickness of the elastic member is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1.0 mm to 3.0 mm.

[0031] <Coating layer> The cleaning blade has a coating layer on the blade tip surface with which the member to be cleaned comes into contact, and does not have the coating layer on the blade lower surface perpendicular to the blade tip surface. If the cleaning blade does not have the coating layer on the underside of the blade, the radius of curvature of the contact portion when the cleaning blade contacts the member to be cleaned does not become too large, and deterioration of cleaning performance can be suppressed. The coating layer is present at least in the portion where the cleaning blade contacts the member to be cleaned. By providing the coating layer at the portion where the cleaning blade contacts the member to be cleaned, the cleaning blade is less likely to turn over, and torque increase is less likely to occur.

[0032] The coating layer is preferably present on a part of the blade tip surface, in the range from a position up to 900 μm away from the blade tip ridge to the end of the blade tip surface opposite the blade tip ridge, and more preferably present on the entire blade tip surface. When the coating layer is present within the above range, the proportion of the area of ​​the coating layer present at the portion where the cleaning blade contacts the member to be cleaned increases, making the cleaning blade less likely to turn over.

[0033] When the coating layer is present on a portion of the blade tip surface in a range from a position up to 900 μm away from the blade tip ridge to the end of the blade tip surface facing the blade tip ridge, the cleaning performance is likely to be good because the coating layer is not present around the tip ridge of the cleaning blade. In this case, it is preferable that the area where the coating layer is not present is coated with a touch-up agent, and it is more preferable that the lower surface of the blade is also coated with a touch-up agent. When the above range is coated with a touch-up agent, the cleaning blade is less likely to turn over.

[0034] The coating layer may be a membrane or film containing fine particles and a binding component, or an organic monolayer having a perfluoroalkyl chain.

[0035] <<Film containing fine particles and binding components>> When the coating layer is a film containing fine particles and a binding component, the coating layer can be formed by applying a fine particle dispersion, which is a mixture of fine particles, a binding component, and a solvent for dispersing them, to the elastic member and drying it.

[0036] -Fine particles- The fine particles are not particularly limited and can be appropriately selected depending on the purpose. Examples of the fine particles include fine particles of inorganic compounds and fine resin particles. Examples of inorganic compounds that can be used for the fine particles of the inorganic compound include silica, alumina, and zirconia. Examples of resins that can be used for the resin particles include fluorine-based resins, acrylic resins, styrene-based resins, and vinyl-based resins. These may be used alone or in combination of two or more. Among these, fluorine-based resins having a low sliding function are preferred.

[0037] Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), fluorinated ethylene-propylene copolymer (FEP), perfluoroalkoxy polymer (PFA), chlorotrifluoroethylene copolymer (CTFE), tetrafluoroethylene-chlorotrifluoroethylene copolymer (TFE / CTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and polychlorotrifluoroethylene (PCTFE). Among these, polytetrafluoroethylene (PTFE) is preferred because it has the most excellent properties among the resin materials. The fine particles (including micropowder) of such fluorine-based resins such as polytetrafluoroethylene (PTFE) are preferably obtained by emulsion polymerization.

[0038] Polytetrafluoroethylene (PTFE) may be a synthetic product or a commercially available product, such as Dyneon TF Micropowder TF-9201Z, Dyneon TF Micropowder TF-9207Z (both manufactured by 3M), Nano FLON119N, FLUORO E (both manufactured by Shamrock), TLP10F-1 (manufactured by Mitsui-DuPont Fluorochemicals), KTL-500F (manufactured by Kitamura Co., Ltd.), and Algoflon L203F (manufactured by SOLVAY).

[0039] The shape of the fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably spherical. The volume average particle diameter of the microparticles is not particularly limited and can be appropriately selected depending on the purpose, but the volume-based average particle diameter (50% volume diameter, median diameter) measured by a laser diffraction / scattering method, a dynamic light scattering method, an image imaging method, or the like is preferably 0.1 μm or more and 1 μm or less, more preferably 0.1 μm or more and 0.5 μm or less, and even more preferably 0.1 μm or more and 0.3 μm or less. When the volume average particle size is 0.1 μm or more and 1 μm or less, the particles are more likely to settle in the solvent described below and are more likely to be dispersed stably. When the volume average particle size is 0.1 μm or more and 0.5 μm or less, the particles are more likely to be dispersed stably in the solvent.

[0040] Methods for measuring the volume average particle diameter of the fine particles include, for example, a method in which the fine particles are sampled from the cleaning blade and the sampled fine particles are subjected to a particle size analyzer (Microtrack, manufactured by Nikkiso Co., Ltd.) to measure the volume average particle diameter by a laser diffraction / scattering method, and a method in which the fine particles on the cleaning blade are directly observed and measured using a scanning electron microscope (SEM). The volume average particle size of the fine particles is almost the same when they are added to the coating layer during the production of the cleaning blade and when they are present in the coating layer.

[0041] -Binding component- The binder component is not particularly limited as long as it can disperse the above-mentioned fine particles uniformly and stably, and can be appropriately selected depending on the purpose, but a fluorine-based resin is preferable, and a ternary copolymer of VdF-HFP-TFE consisting of vinylidene fluoride (VdF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE) is more preferable. From the viewpoint of flexibility as a binder component and solubility in a solvent, the molar ratio of VdF monomer unit, HFP monomer unit, and TFE monomer unit in the composition of VdF / HFP / TFE is preferably 30-80 mol% / 10-35 mol% / 5-35 mol%.

[0042] In addition, by further adding a fluorine-based oil to the binding component, not only the function as a binder but also the sliding function can be further improved. Examples of the fluorine-based oil include those having a TFE oligomer or a perfluoroether as the main skeleton.

[0043] The fluorine-based oil having a perfluoroether skeleton as the main structure is not particularly limited and can be appropriately selected as long as it has sliding properties and does not inhibit the dispersion of the above-mentioned fine particles, but from the viewpoint of kinetic viscosity, a fluorine-based oil having an average molecular weight of about 2,000 to 3,500 is preferred. Examples of fluorine-based oils having a perfluoroether skeleton as the main structure include PT-02 (molecular weight 2000), PT-82 (molecular weight 2800), and PT-53 (molecular weight 3500) manufactured by NICCA CHEMICAL.

[0044] -solvent- The solvent is not particularly limited and can be appropriately selected depending on the purpose. For example, a fluorine-containing organic solvent can be used. Examples of the fluorine-containing organic solvent include hydrofluoroethers (HFEs), perfluorocarbons (PFCs), and perfluoroethers (PFEs). These may be used alone or in combination of two or more.

[0045] The method for producing the microparticle dispersion is not particularly limited and may be appropriately selected depending on the purpose. For example, the microparticle dispersion may be produced by mixing the fluorine-containing organic solvent, which is the solvent, with the binder component, and adding the microparticles to the obtained mixture (binder component dispersion) and mixing them. The average particle size of the fine particles in the fine particle dispersion by dynamic light scattering (average particle size as determined by cumulant method analysis in scattering intensity distribution) is preferably 1 μm or less.

[0046] Even when fine particles having a volume average particle size of 1 μm or less are used, the fine particles usually aggregate to form secondary particles having a secondary particle size of 1 μm or more. By dispersing these fine particles in a binder component dispersion so that the volume average particle diameter is 1 μm or less, a stable fine particle dispersion can be obtained even when the fine particle dispersion is stored for a long period of time at a low viscosity. Examples of the method for dispersing fine particles include a method using a dispersing machine such as an ultrasonic disperser, a three-roll mill, a ball mill, a bead mill, or a jet mill. The volume average particle size of the microparticles in the microparticle dispersion is preferably 0.1 μm to 1 μm, more preferably 0.1 μm to 0.5 μm, and even more preferably 0.1 μm to 0.3 μm, in order to obtain a uniform microparticle dispersion.

[0047] When the coating layer is a film containing fine particles and a binding component, the method for forming the coating layer is not particularly limited and can be appropriately selected depending on the purpose. For example, there is a method in which the elastic member, the underside of which is masked to prevent the fine particle dispersion from adhering to the underside of the blade, is dipped into the fine particle dispersion and then dried at room temperature. The film containing the fine particles and the binding component is preferably formed at least on the portion where the cleaning blade contacts the member to be cleaned, and is preferably formed on the entire surface of the blade tip surface. When the film containing the fine particles and the binding component is formed on a portion of the blade tip surface by dipping the elastic member in the fine particle dispersion, the masking or other treatment is preferably performed on the blade lower surface as well as on the area of ​​the blade tip surface where no coating layer is to be formed. The area on the blade tip surface where no coating layer is formed is preferably an area up to a position 900 μm away from the ridge line of the blade tip. As a method for forming the coating layer, in addition to the dipping, coating methods such as spray coating and dispenser coating may be used.

[0048] The film containing the fine particles and the binding component is preferably a film containing polytetrafluoroethylene (PTFE) fine particles and a fluorine-based resin as the binding component. The film containing the fine particles and the binding component preferably has an average thickness of 10 μm or less at a position 50 μm from the edge of the blade tip. When the average thickness of the film containing the fine particles and the binding component is within the above range, the radius of curvature of the portion where the cleaning blade contacts the member to be cleaned is unlikely to become large, resulting in good cleaning properties. The average thickness of the film containing the fine particles and binding components can be measured, for example, by scraping off a portion of the coating layer with a spatula or cotton swab, and measuring the shape using a contact surface roughness meter (Surftest SJ-500, manufactured by Mitutoyo) or a confocal laser microscope (3D measuring laser microscope LEXT OLS5100, manufactured by Olympus).

[0049] <<Film>> When the covering layer is a film, it can be formed by cutting it to an appropriate size and attaching it to the entire surface of the blade tip surface or to a part of the blade tip surface. The film is attached to at least the part where the cleaning blade contacts the member to be cleaned, and is preferably attached to the entire surface of the blade tip surface. When attaching a film to a part of the blade tip surface, it is preferably attached in a range from a position up to 900 μm away from the blade tip ridge to the end of the blade tip surface facing the blade tip ridge. The film is preferably a low-friction film, and the material of the film is preferably a hard film with high slidability such as Teflon (registered trademark) or ultra-high molecular weight polyethylene, because this makes it easy to suppress an increase in torque.

[0050] <<Organic monolayers with perfluoroalkyl chains>> When the coating layer is an organic monomolecular film having a perfluoroalkyl chain, the coating layer formed is thin and has a state similar to that of an elastic member, which is preferable from the viewpoint of cleaning properties. The method for forming the organic monolayer having a perfluoroalkyl chain can be appropriately selected. It is preferable to mask the underside of the blade, and then subject the entire tip surface of the blade or a part of the tip surface of the blade to a hydrophilic treatment such as oxygen plasma treatment to increase wettability with the elastic member, and then form a coating layer by a treatment such as vapor deposition or immersion. The organic monolayer having a perfluoroalkyl chain is preferably formed at least on the portion of the cleaning blade that contacts the member to be cleaned, and is preferably formed on the entire surface of the blade tip surface. When the organic monolayer having a perfluoroalkyl chain is formed on a portion of the blade tip surface, it is preferably formed in a range from a position up to 900 μm away from the blade tip ridge to the end of the blade tip surface that faces the blade tip ridge. When forming an organic monolayer having a perfluoroalkyl chain on a portion of the blade tip surface, it is preferable to perform the hydrophilization treatment after masking, for example, areas of the blade tip surface where no coating layer is to be formed, in addition to the underside of the blade.

[0051] <Parts to be cleaned> The material, shape, structure, size, etc. of the member to be cleaned are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the member to be cleaned include drum, belt, plate, sheet, etc. The size of the member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose, but a size that is generally used is preferable.

[0052] The material of the member to be cleaned is not particularly limited and may be appropriately selected depending on the purpose, and examples of the material include metal, plastic, and ceramic. The member to be cleaned is not particularly limited and can be appropriately selected depending on the purpose. When the cleaning blade is applied to an image forming apparatus, examples of the member to be cleaned include an image carrier, a photoreceptor, and an electrophotographic photoreceptor.

[0053] <Residue> The residue is not particularly limited as long as it is attached to the surface of the member to be cleaned and is a target for removal by the cleaning blade, and may be appropriately selected depending on the purpose. Examples of the residue include toner, lubricant, inorganic fine particles, organic fine particles, dirt, dust, and mixtures thereof.

[0054] <Other materials> The other members are not particularly limited and can be appropriately selected depending on the purpose. For example, a support member can be mentioned. The shape, size, material, etc. of the support member are not particularly limited and can be appropriately selected depending on the purpose. Examples of the shape of the support member include a flat plate, a strip, a sheet, etc. The size of the support member is not particularly limited and can be appropriately selected depending on the size of the member to be cleaned. Examples of materials for the support member include metals, plastics, ceramics, etc. Among these, metal plates are preferred from the viewpoint of strength, and steel plates such as stainless steel, aluminum plates, and phosphor bronze plates are particularly preferred.

[0055] Here, an example of the cleaning blade in the present invention will be described with reference to the drawings. In addition, in each drawing, the same components are denoted by the same reference numerals, and duplicated explanations may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to the present embodiment, and may be any number, position, shape, etc. that is preferable for implementing the present invention.

[0056] FIG. 1 is a schematic cross-sectional view of an example of a state in which a cleaning blade according to an embodiment of the present invention is in contact with the surface of an image bearing member. 1, the cleaning blade 62 is composed of a flat support member 621 made of a rigid material such as metal or hard plastic, and a flat blade base 622. The blade base 622 is fixed to one end of the support member 621 by adhesive or the like, and the other end of the support member 621 is supported in a cantilever manner by the case of the cleaning device.

[0057] FIG. 2 is a perspective view of a cleaning blade according to one embodiment of the present invention. As shown in FIG. 2, the cleaning blade 62 comprises a support member 621 and a flat blade base 622 having one end connected to the support member 621 and the other end having a free end of a predetermined length, and is positioned so that the blade tip ridge portion 62c, which is one end on the free end side of the blade base 622, abuts against the surface of the image carrier along the longitudinal direction. The blade substrate 622 has a coating layer 62d at least at the portion where the cleaning blade 62 contacts the image carrier 3.

[0058] (Process cartridge) The process cartridge according to one embodiment of the present invention comprises: An image carrier; At least one of a charging means for charging a surface of the image carrier, an exposure means for exposing the charged surface of the image carrier to light to form an electrostatic latent image, a developing means for developing the electrostatic latent image into a toner image, and a transfer means for transferring the toner image onto a recording medium; a cleaning means for contacting the surface of the image carrier to remove residues on the surface of the image carrier; The cleaning means includes the cleaning blade. The process cartridge is detachably mountable to the main body of the image forming apparatus, and may further include other means as necessary.

[0059] (Image forming apparatus and image forming method) An image forming apparatus according to an embodiment of the present invention comprises: An image carrier; a charging means for charging the surface of the image carrier; an exposure unit for exposing the charged surface of the image carrier to light to form an electrostatic latent image; a developing means for developing the electrostatic latent image into a toner image; a transfer means for transferring the toner image onto a recording medium; a fixing unit for fixing the toner image transferred onto the recording medium; a cleaning means for contacting the surface of the image carrier to remove residues on the surface of the image carrier; The cleaning means includes the cleaning blade. The image forming apparatus may further include other units as necessary. The charging means and the exposure means may be collectively referred to as an electrostatic latent image forming means.

[0060] An image forming method according to one embodiment of the present invention includes the steps of: a charging step of charging a surface of an image carrier; an exposure step of exposing the charged surface of the image carrier to light to form an electrostatic latent image; a developing step of developing the electrostatic latent image into a toner image; a transfer step of transferring the toner image onto a recording medium; a fixing step of fixing the toner image transferred onto the recording medium; The cleaning step includes contacting the cleaning blade with the surface of the image bearing member to remove residues on the surface of the image bearing member. The image forming method may further include other steps as necessary. The charging step and the exposure step may be collectively referred to as an electrostatic latent image forming step.

[0061] <Image carrier> The image carrier is not particularly limited in terms of material, shape, structure, size, etc., and can be appropriately selected from known ones. A preferred shape is a drum shape, and examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Examples of the organic photoreceptor include a laminated photoreceptor having a laminated structure in which a layer (charge generation layer) in which a charge generation material such as metal-free phthalocyanine, titanyl phthalocyanine, or gallium phthalocyanine is dispersed in a binder resin and a layer (charge transport layer) in which a charge transport material is dispersed in a binder resin are stacked on a support such as an aluminum drum, and a single-layered photoreceptor having a single-layered photosensitive layer on a support in which both a charge generation material and a charge transport material are dispersed in a binder resin. In the single-layered photoreceptor, a hole transport material and an electron transport material can also be added to the photosensitive layer as charge transport materials. An undercoat layer may be provided between the support and the multi-layer charge generating layer or the single-layer photosensitive layer.

[0062] <Charging process and charging means> The charging step is a step of charging the surface of the image bearing member, and can be suitably performed by the charging unit. The charging means is not particularly limited as long as it can charge the surface of the image bearing member, and can be appropriately selected depending on the purpose. Examples of the charging means include a contact charger known per se having a conductive or semiconductive roller, brush, film, rubber blade, etc., and a non-contact charger that utilizes corona discharge such as a corotron or scorotron. The charging means may have any shape, such as a roller, a magnetic brush, a fur brush, etc., and can be selected according to the specifications and shape of an electrophotographic image forming apparatus. When a magnetic brush is used as the charging means, it is preferable to use various ferrite particles, such as Zn-Cu ferrite, as the magnetic brush, and it is preferable that the magnetic brush is composed of a non-magnetic conductive sleeve for supporting the magnetic brush and a magnet roll contained within the sleeve. When using a brush other than a magnetic brush, such as a fur brush, the material may be fur that has been treated to be conductive with carbon, copper sulfide, metal or metal oxide, and this can be wrapped or attached to a metal or other conductive core to make a charger. The charger is not limited to the contact type charger described above, but by using the charger, it is possible to obtain an image forming apparatus in which the amount of ozone generated from the charger is reduced. The charger is preferably disposed in contact with or without contact with the image bearing member, and charges the surface of the image bearing member by applying DC and AC voltages in a superimposed manner. The charger is preferably a charging roller having a gap tape and arranged close to the image carrier without contacting the image carrier, and preferably charges the surface of the image carrier by applying superimposed DC and AC voltages to the charging roller.

[0063] <Exposure Step and Exposure Means> The exposure step is a step of exposing the charged surface of the image carrier to light to form an electrostatic latent image, and can be suitably performed by the exposure unit. The exposure step can be performed, for example, by exposing the surface of the image carrier to light in an imagewise manner using the exposure unit. The optical system in the exposure is roughly divided into an analog optical system and a digital optical system. The analog optical system is an optical system that directly projects an original onto the surface of the image carrier by an optical system, while the digital optical system is an optical system that receives image information as an electrical signal, converts the electrical signal into an optical signal, and exposes the image carrier to form an image. The exposure means is not particularly limited as long as it can expose the charged image carrier to light to form an electrostatic latent image, and can be appropriately selected depending on the purpose. Examples of the exposure means include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, a liquid crystal shutter optical system, and an LED optical system. In the present invention, a backlight system in which exposure is performed imagewise from the back side of the image carrier may be adopted.

[0064] <Developing step and developing means> The developing step is a step of developing the electrostatic latent image into the toner image, and can be suitably performed by the developing unit. The developing means is not particularly limited as long as it can develop the electrostatic latent image into a toner image, and can be appropriately selected depending on the purpose. For example, a developing means that contains the toner and has at least a developing unit that can apply the toner to the electrostatic latent image by contact or non-contact is preferably used. The developing device may be of a dry developing type or a wet developing type, and may be a single-color developing device or a multi-color developing device. For example, a suitable developing device includes an agitator that charges the toner by friction stirring, and a rotatable magnetic roller. In the developing device, for example, the toner and, if necessary, a carrier are mixed and stirred, and the toner is charged by friction during this process and held in a bristled state on the surface of the rotating magnet roller, forming a magnetic brush. Since the magnet roller is disposed in the vicinity of the image carrier, a portion of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the image carrier by the electrical attraction force of the electrostatic latent image. As a result, the electrostatic latent image is developed by the toner, and the toner image is formed on the surface of the image carrier. The toner contained in the developing device may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer. The toner may be a one-component magnetic toner that does not use a carrier, or may be a non-magnetic toner when used together with a carrier.

[0065] <Transfer process and transfer means> The transfer step is a step of transferring the toner image onto a recording medium, and can be suitably performed by the transfer unit. The transfer step preferably includes, for example, a primary transfer step in which an intermediate transfer body is used and the toner image is transferred to the surface of the intermediate transfer body to form a composite transfer image, and a secondary transfer step in which the composite transfer image is transferred to a recording medium. The transfer means is not particularly limited as long as it can transfer the toner image onto a recording medium, and can be appropriately selected depending on the purpose. A preferred embodiment has a primary transfer means that transfers the toner image onto the surface of the intermediate transfer body to form a composite transfer image, and a secondary transfer means that transfers the composite transfer image onto a recording medium. The primary transfer means and the secondary transfer means preferably include, for example, at least a transfer device that peels and charges the toner image formed on the surface of the image carrier onto a recording medium. The transfer device is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device, etc. The number of the transfer devices may be one or more.

[0066] The recording medium is not particularly limited as long as it is capable of transferring the unfixed toner image after development, and can be appropriately selected depending on the purpose. A typical example is plain paper, but for example, a PET base for an OHP can also be used.

[0067] <Fixing process and fixing means> The fixing step is a step of fixing the toner image transferred to the recording medium, and can be suitably performed by the fixing unit. When toners of two or more colors are used, the toners of each color may be fixed each time they are transferred to the recording medium, or the toners of all colors may be fixed in a laminated state after being transferred to the recording medium. The fixing means is not particularly limited as long as it can fix the toner image transferred to the recording medium, and can be appropriately selected depending on the purpose. A thermal fixing method using a known heating and pressurizing means can be adopted. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller and an endless belt. The heating temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 80° C. to 200° C. If necessary, a known optical fixing device, for example, may be used together with the fixing means.

[0068] <Cleaning process and cleaning means> The cleaning step is a step of removing residues on the surface of the image bearing member, and can be suitably performed by the cleaning means. The cleaning means is preferably a cleaning blade of the present invention fixed to a supporting member.

[0069] The linear pressure applied by the cleaning means to the surface of the image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 N / m to 100 N / m, more preferably 10 N / m to 50 N / m. When the linear pressure is 10 N / m to 100 N / m, cleaning failure caused by the toner passing through the gap between the cleaning means and the image carrier at the contact portion is unlikely to occur, and curling of the cleaning means can be easily suppressed. The linear pressure can be measured, for example, by using a measuring device incorporating a small compression load cell manufactured by Kyowa Electric Industry Co., Ltd.

[0070] The angle between the tangent to the image carrier at the position where the cleaning means contacts the image carrier and the tip surface of the free end of the cleaning means (hereinafter referred to as the "cleaning angle") is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 65° or more and 85° or less. When the cleaning angle is 65° or more and 85° or less, the occurrence of curling of the cleaning means can be easily suppressed, and the occurrence of cleaning defects can be easily reduced.

[0071] <Other steps and other means> Examples of the other steps include a static elimination step, a recycling step, and a control step. Examples of the other means include a static elimination means, a recycling means, and a control means.

[0072] -Static charge removal process and static charge removal means- The charge removing step is a step of removing electricity by applying a charge removing bias voltage to the image bearing member, and can be performed by the charge removing unit. The charge removing means is not particularly limited as long as it can apply a charge removing bias voltage to the image bearing member, and can be appropriately selected depending on the purpose. For example, a charge removing lamp can be used.

[0073] -Recycling process and methods- The recycling step is a step of recycling the toner, which is the residue removed from the surface of the image carrier in the cleaning step, to the developing means, and can be performed by the recycling means. The recycling means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include known transport means.

[0074] -Control process and control means- The control step is a step of controlling each of the steps, and can be performed by a control means. The control means is not particularly limited as long as it can control the movement of each of the means, and can be appropriately selected depending on the purpose. Examples of the control means include devices such as a sequencer and a computer.

[0075] Here, an example of an image forming apparatus of the present invention will be described with reference to the drawings. FIG. 3 is a schematic cross-sectional view of an image forming apparatus according to one embodiment of the present invention. 3 includes four imaging units 1Y, 1C, 1M, and 1K for yellow, magenta, cyan, and black (hereinafter sometimes referred to as Y, C, M, and K). These units use different colors of Y, C, M, and K toner as image forming substances for forming images, but otherwise have the same configuration.

[0076] A transfer unit 60 including an intermediate transfer belt 14 as an intermediate transfer body is disposed above the four imaging units 1Y, 1C, 1M, and 1K. The toner images of each color formed on the surfaces of image carriers 3Y, 3C, 3M, and 3K included in each of the imaging units 1Y, 1C, 1M, and 1K, which will be described in detail later, are transferred onto the surface of the intermediate transfer belt 14 in a superimposed state. An optical writing unit 40 is disposed below the four imaging units 1Y, 1C, 1M, and 1K. The optical writing unit 40, which is an electrostatic latent image forming means, irradiates the image carriers 3Y, 3C, 3M, and 3K of the imaging units 1Y, 1C, 1M, and 1K with laser light L emitted based on image information. As a result, electrostatic latent images for Y, C, M, and K are formed on the image carriers 3Y, 3C, 3M, and 3K. The optical writing unit 40 irradiates the laser light L emitted from a light source onto the image carriers 3Y, 3C, 3M, and 3K through a plurality of optical lenses and mirrors while polarizing the laser light L by a polygon mirror 41 that is driven to rotate by a motor. Instead of the above configuration, an optical scanning unit using an LED array may be used.

[0077] Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged so as to be stacked vertically. In each of these paper feed cassettes, a plurality of recording media P are stored in a stack of paper, and a first paper feed roller 151a and a second paper feed roller 152a are in contact with the top recording medium P. When the first paper feed roller 151a is driven to rotate counterclockwise in FIG. 3 by a driving means, the top recording medium P in the first paper feed cassette 151 is discharged toward a paper feed path 153 disposed to extend vertically on the right side of the cassette in FIG. 3. When the second paper feed roller 152a is driven to rotate counterclockwise in FIG. 3 by a driving means, the top recording medium P in the second paper feed cassette 152 is discharged toward the paper feed path 153.

[0078] A plurality of conveying roller pairs 154 are disposed in the paper feed path 153. The recording medium P sent into the paper feed path 153 is conveyed in the paper feed path 153 from the lower side to the upper side in FIG. 3 while being sandwiched between the rollers of the conveying roller pairs 154.

[0079] A pair of registration rollers 55 is disposed at the downstream end in the transport direction of the paper feed path 153. As soon as the pair of registration rollers 55 sandwiches the recording medium P fed from the pair of transport rollers 154 between the rollers, the pair of registration rollers 55 temporarily stops the rotation of both rollers. Then, the pair of registration rollers 55 sends the recording medium P toward a secondary transfer nip, which will be described later, at an appropriate timing.

[0080] FIG. 4 is a schematic cross-sectional view of an example of an imaging unit in an image forming apparatus according to one embodiment of the present invention, and shows an example of the configuration of one of the four imaging units 1Y, 1C, 1M, and 1K shown in FIG. 4, the imaging unit 1 includes a drum-shaped image carrier 3 as an image carrier. Although the image carrier 3 is shown to have a drum shape, it may also be in the form of a sheet or an endless belt. Around the image carrier 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant application device 10, a static electricity removal lamp, and the like are arranged. The charging roller 4 is a charging member provided in a charging device as a charging means, and the developing device 5 is a developing means for converting an electrostatic latent image formed on the surface of the image carrier 3 into a toner image. The primary transfer roller 7 is a primary transfer member provided in a primary transfer device as a primary transfer means for transferring a toner image on the surface of the image carrier 3 to an intermediate transfer belt 14. The cleaning device 6 is a cleaning means for cleaning toner remaining on the image carrier 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant application device 10 is a lubricant application means for applying a lubricant to the surface of the image carrier 3 after cleaning by the cleaning device 6. The static electricity removal lamp is a static electricity removal means for removing the surface potential of the image carrier 3 after cleaning.

[0081] The charging roller 4 is disposed at a predetermined distance from the image carrier 3 in a non-contact manner, and charges the image carrier 3 to a predetermined polarity and a predetermined potential. The surface of the image carrier 3 that has been uniformly charged by the charging roller 4 is irradiated with laser light L from an optical writing unit 40, which is an electrostatic latent image forming means, based on image information, and an electrostatic latent image is formed. The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to this developing roller 51 from a power source. A supply screw 52 and an agitating screw 53 are provided inside the casing of the developing device 5, which agitate the developer contained in the casing while transporting it in opposite directions. A doctor 54 is also provided to regulate the developer carried by the developing roller 51. The toner in the developer agitated and transported by the twin screws, the supply screw 52 and the agitating screw 53, is charged to a predetermined polarity. The developer is then pumped up onto the surface of the developing roller 51, and the developer is then pumped up and discharged. The raised developer is regulated by the doctor 54 , and in the development area facing the image carrier 3 , the toner adheres to the electrostatic latent image on the image carrier 3 .

[0082] The cleaning device 6 includes a fur brush 101 and a cleaning blade 62. The cleaning blade 62 contacts the image carrier 3 in a counter direction to the surface movement direction of the image carrier 3. The details of the cleaning blade 62 are as described above. The lubricant applicator 10 includes a solid lubricant 103, a lubricant pressure spring 103a, etc., and uses a fur brush 101 as an application brush that applies the solid lubricant 103 onto the image carrier 3. The solid lubricant 103 is held by a bracket 103b, and is pressed toward the fur brush 101 by the lubricant pressure spring 103a. The solid lubricant 103 is scraped off by the fur brush 101, which rotates in the same direction as the image carrier 3, and the lubricant is applied onto the image carrier 3. By applying the lubricant to the image carrier, the friction coefficient of the surface of the image carrier 3 is maintained at 0.2 or less during non-image formation.

[0083] The charging device is a non-contact close-by arrangement type in which the charging roller 4 is placed close to the image carrier 3, but the charging device may be of any known configuration, including a corotron, scorotron, or solid-state charger. Of these charging methods, the contact charging method or the non-contact close-by arrangement method is more desirable, as it has the advantages of high charging efficiency, low ozone generation, and the ability to miniaturize the device.

[0084] The light source for the laser light L of the optical writing unit 40 and the light source for the discharge lamp can be any light-emitting material such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light-emitting diode (LED), a semiconductor laser (LD), or an electroluminescence (EL). In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used. Of these light sources, light emitting diodes and semiconductor lasers are preferably used since they have high irradiation energy and emit light with a long wavelength of 600 nm or more and 800 nm or less.

[0085] The transfer unit 60 as a transfer means shown in FIG. 3 includes the intermediate transfer belt 14, a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like. It also includes four primary transfer rollers 7Y, 7C, 7M, and 7K, a secondary transfer backup roller 66, a drive roller 67, an auxiliary roller 68, and a tension roller 69. The intermediate transfer belt 14 is endlessly moved counterclockwise in FIG. 3 by the rotational drive of the drive roller 67 while being stretched around these eight roller members. The four primary transfer rollers 7Y, 7C, 7M, and 7K sandwich the intermediate transfer belt 14 thus endlessly moved between the image carriers 3Y, 3C, 3M, and 3K to form primary transfer nips. A transfer bias of the opposite polarity (for example, positive) to that of the toner is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 14. As the intermediate transfer belt 14 moves endlessly, it passes through the primary transfer nips for Y, C, M, and K in sequence, and the Y, C, M, and K toner images on the image carriers 3Y, 3C, 3M, and 3K are primarily transferred onto the front surface of the intermediate transfer belt 14 in a superimposed manner. As a result, a four-color superimposed toner image (hereinafter sometimes referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

[0086] The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 between itself and a secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14, forming a secondary transfer nip. The registration roller pair 55 described above sends the recording medium P sandwiched between the rollers toward the secondary transfer nip at a timing that allows synchronization with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is collectively secondarily transferred to the recording medium P in the secondary transfer nip due to the influence of the secondary transfer electric field formed between the secondary transfer roller 70, to which a secondary transfer bias is applied, and the secondary transfer backup roller 66, and the nip pressure. Then, the recording medium P is transferred to the secondary transfer nip. Combined with the white color of the recording medium P, this forms a full-color toner image.

[0087] After passing through the secondary transfer nip, residual toner that has not been transferred to the recording medium P adheres to the intermediate transfer belt 14. This is cleaned by a belt cleaning unit 162. The belt cleaning unit 162 brings a belt cleaning blade 162a into contact with the front surface of the intermediate transfer belt 14, thereby scraping off and removing the residual toner on the intermediate transfer belt 14.

[0088] The first bracket 63 of the transfer unit 60 is adapted to swing at a predetermined rotation angle around the rotation axis of the auxiliary roller 68 as the solenoid is turned on and off. When forming a monochrome image, the image forming apparatus 500 rotates the first bracket 63 slightly counterclockwise in FIG. 3 by driving the solenoid described above. This rotation causes the primary transfer rollers 7Y, 7C, and 7M for Y, C, and M to revolve around the rotation axis of the auxiliary roller 68 counterclockwise in FIG. 3, thereby separating the intermediate transfer belt 14 from the image carriers 3Y, 3C, and 3M for Y, C, and M. Then, of the four imaging units 1Y, 1C, 1M, and 1K, only the imaging unit 1K for K is driven to form a monochrome image. This makes it possible to avoid wear of each member constituting the imaging unit 1 due to unnecessary driving of the imaging units 1 for Y, C, and M during monochrome image formation.

[0089] A fixing unit 80 is disposed above the secondary transfer nip in FIG. 3. The fixing unit 80 includes a pressure heating roller 81 containing a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a driving roller 86, a temperature sensor, and the like. The endless fixing belt 84 is stretched by the heating roller 83, the tension roller 85, and the driving roller 86 and moves endlessly in the counterclockwise direction in FIG. 3. During this endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. The pressure heating roller 81, which is driven to rotate in the clockwise direction in FIG. 3, abuts on the front side of the fixing belt 84, which is heated in this way, at the place where the fixing belt 84 is wrapped around the heating roller 83. As a result, a fixing nip is formed where the pressure heating roller 81 and the fixing belt 84 abut on each other.

[0090] A temperature sensor is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a specified gap therebetween, and detects the surface temperature of the fixing belt 84 immediately before it enters the fixing nip. The detection result is sent to a fixing power supply circuit. The fixing power supply circuit controls the on / off of the power supply to the heat source contained in the heating roller 83 and the heat source contained in the pressure heating roller 81 based on the detection result by the temperature sensor.

[0091] The recording medium P that has passed through the secondary transfer nip described above is separated from the intermediate transfer belt 14 and then sent into the fixing unit 80. Then, in the process of being conveyed from the bottom to the top in FIG. 3 while being sandwiched in the fixing nip inside the fixing unit 80, the recording medium P is heated and pressed by the fixing belt 84, whereby the full-color toner image is fixed onto the recording medium P.

[0092] The recording medium P thus subjected to the fixing process is discharged outside the image forming apparatus after passing between the rollers of the discharge roller pair 87. A stack section 88 is formed on the upper surface of the housing of the main body of the image forming apparatus 500, and the recording medium P discharged outside the image forming apparatus by the discharge roller pair 87 is stacked in this stack section 88 in order.

[0093] Four toner cartridges 100Y, 100C, 100M, and 100K containing Y, C, M, and K toners are disposed above the transfer unit 60. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, 100M, and 100K are appropriately supplied to the developing devices 5Y, 5C, 5M, and 5K of the image forming units 1Y, 1C, 1M, and 1K. These toner cartridges 100Y, 100C, 100M, and 100K are detachable from the image forming apparatus main body independently of the image forming units 1Y, 1C, 1M, and 1K.

[0094] Next, the image forming operation in the image forming apparatus 500 will be described. First, when a print execution signal is received from an operation unit or the like, a predetermined voltage or current is sequentially applied at a predetermined timing to the charging roller 4 and the developing roller 51 shown in Fig. 4. Similarly, a predetermined voltage or current is sequentially applied at a predetermined timing to the optical writing unit 40 and the light source such as the static elimination lamp shown in Fig. 3. In synchronization with this, the image carriers 3, 3Y, 3C, 3M, and 3K are rotated in the directions of the arrows in Figs. 3 and 4 by an image carrier drive motor serving as a drive means.

[0095] 4, the surface of the image carrier 3 is first uniformly charged to a predetermined potential by the charging roller 4. Then, laser light L corresponding to image information is irradiated onto the image carrier 3 from the optical writing unit 40, and the portion on the surface of the image carrier 3 irradiated with the laser light L is neutralized to form an electrostatic latent image. The surface of the image carrier 3 on which the electrostatic latent image is formed is rubbed by a magnetic brush of developer formed on the developing roller 51 at the portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 moves to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51, and is turned into a toner image (developed). In each of the imaging units 1Y, 1C, 1M, and 1K shown in FIG. 3, an imaging process similar to that of the imaging unit 1 in FIG. 4 is performed, and a toner image of each color is formed on the surface of each of the image carriers 3Y, 3C, 3M, and 3K of each of the imaging units 1Y, 1C, 1M, and 1K. In this manner, in the image forming apparatus 500, the electrostatic latent image formed on the image carrier 3 is reverse-developed by the developing device 5 with negatively charged toner. In the present embodiment, an example using an N / P (negative / positive: toner adheres to a location with a low potential) non-contact charging roller method has been described, but the present invention is not limited to this.

[0096] The toner images of each color formed on the surface of each image carrier 3Y, 3C, 3M, and 3K are sequentially primarily transferred so as to be superimposed on the surface of the intermediate transfer belt 14. As a result, a four-color toner image is formed on the intermediate transfer belt 14. The four-color toner image formed on the intermediate transfer belt 14 is transferred onto the recording medium P, which is fed from the first paper feed cassette 151 or the second paper feed cassette 152 and passes between the rollers of the registration roller pair 55 and is fed to the secondary transfer nip. At this time, the recording medium P is stopped once while being sandwiched between the registration roller pair 55, and is fed to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The recording medium P onto which the toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. Then, the recording medium P onto which the toner image has been transferred passes through the fixing unit 80, whereby the toner image is fixed onto the recording medium P by the action of heat and pressure, and the recording medium P onto which the toner image has been fixed is discharged outside the image forming apparatus 500 and stacked in the stack section 88.

[0097] On the other hand, the surface of the intermediate transfer belt 14 from which the toner image has been transferred to the recording medium P at the secondary transfer nip is cleaned by a belt cleaning unit 162 to remove any residual toner remaining on the surface. In addition, the surface of the image carrier 3, from which the toner images of each color have been transferred to the intermediate transfer belt 14 at the primary transfer nip, has residual toner removed by a cleaning device 6, has lubricant applied to it by a lubricant application device 10, and is then de-electrified by a de-electrification lamp.

[0098] 4, the imaging unit 1 of the image forming apparatus 500 includes an image carrier 3 and, as process means, a charging roller 4, a developing device 5, a cleaning device 6, a lubricant applicator 10, etc., housed in a frame 2. The imaging unit 1 is detachable as a process cartridge from the main body of the image forming apparatus 500. In the image forming apparatus 500, the imaging unit 1 is configured so that the image carrier 3 and the process means as a process cartridge are replaced as a whole, but the imaging unit 1 may be configured so that the image carrier 3, the charging roller 4, the developing device 5, the cleaning device 6, and the lubricant applicator 10 are replaced as a unit with new ones. EXAMPLES

[0099] Examples of the present invention will be described below, but the present invention is not limited to these examples. However, "parts" refers to "parts by mass" unless otherwise specified.

[0100] Example 1 <Elastic material> The elastic member used was a polyurethane elastomer sheet produced by centrifugal molding, having the following average thickness, JIS-A hardness, 23° C. rebound resilience, and Martens hardness (HM). Average thickness: 1.8mm JIS-A hardness: 70° 23℃ Rebound elasticity: 50% Martens hardness (HM): 1.0N / mm 2

[0101] <Measurement of JIS-A hardness of elastic materials> The JIS-A hardness of the polyurethane elastomer, which is the elastic member, was measured at 23° C. using a micro rubber hardness tester (MD-1, manufactured by Kobunshi Keiki Co., Ltd.) in accordance with JIS K6253.

[0102] <Measurement of the impact resilience of elastic members> The resilience of the polyurethane elastomer, which is the elastic member, was measured at 23° C. in accordance with JIS K6255 using a resilience tester (No. 221, manufactured by Toyo Seiki Seisakusho Co., Ltd.) The sample used was a laminate of polyurethane elastomer sheets with a thickness of 2 mm, so that the thickness was 4 mm or more.

[0103] <Measurement of Martens hardness of elastic material> The Martens hardness (HM) of the polyurethane elastomer, which is the elastic member, was measured in accordance with ISO 14577 using a nanoindenter (ENT-3100, manufactured by Elionix) by pressing a Berkovich indenter with a load of 1,000 μN for 10 seconds, holding the indenter at that load for 5 seconds, and then removing the indenter at the same load rate for 10 seconds. The measurement was performed on the tip surface of a blade formed from the molded polyurethane elastomer sheet, at a position 20 μm away from the ridge of the blade tip. The Martens hardness is the median value of values ​​measured at 4 to 6 points at each measurement location.

[0104] <Processing into cleaning blades> The obtained polyurethane elastomer sheet was post-cured to complete the curing reaction in the urethane sheet and eliminate any unreacted material in the urethane sheet, and then cured to stabilize the physical properties to produce a blade base, which was then attached to a holder that serves as a support member and processed into a cleaning blade.

[0105] <Preparation of coating layer> A fine particle dispersion was prepared using 4 parts of polytetrafluoroethylene (PTFE) micropowder (TF9201Z, manufactured by 3M, volume average particle diameter 200 nm) as fine particles, 2 parts of a binder component obtained by copolymerizing a ternary copolymer consisting of fluorine-based resins vinylidene fluoride (VdF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE) in a molar ratio of VdF:HFP:TFE=80 mol%:10 mol%:10 mol% in terms of the molar ratio of each monomer unit, and 94 parts of a fluorine-containing organic solvent 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether; HFE-347 (T3057, manufactured by Tokyo Chemical Industry Co., Ltd.).

[0106] The cleaning blade, the underside of which was masked with polyimide tape (heat-resistant polyimide tape 7413D, 3M Japan Co., Ltd., hereinafter the same) to a range of about 0.5 cm from the blade tip ridge, was immersed in the fine particle dispersion at a right angle to the horizontal plane to a depth of 0.2 mm from the blade tip surface to attach the fine particle dispersion to the blade tip surface, and was pulled up at a pulling speed of 1 mm / s so that the average thickness of the coating layer became the target thickness shown in Table 1. In order to gather polytetrafluoroethylene (PTFE) fine particles around the abutment portion necessary for the cleaning function, the blade was tilted at about 45° as shown in Figure 5 and dried at room temperature for 30 minutes to form a coating layer over the entire surface of the blade tip surface, and the polyimide tape used for masking was removed to cover the entire surface of the blade tip surface, thereby producing the cleaning blade of Example 1.

[0107] (Examples 2 to 9, Comparative Examples 1 and 2) In Examples 2 and 3, the pulling speed was adjusted so that the average thickness of the coating layer formed would be the average thickness shown in Table 1, and the rest of the process was the same as in Example 1, and the cleaning blades of Examples 2 and 3 were produced.

[0108] In Examples 4 to 6, the underside of the blade up to a range of approximately 0.5 cm from the blade tip ridge and the tip surface of the blade up to a position 100 μm, 500 μm, and 900 μm from the blade tip ridge were masked with polyimide tape, and as in Examples 1 to 3, the pulling speed was adjusted so that the average thickness of the coating layer would be the average thickness shown in Table 1. The coating layer was then dried to form a coating layer, and the polyimide tape used for masking was then removed to leave part of the blade tip surface covered, resulting in the cleaning blades of Examples 4 to 6.

[0109] In Example 7, a Teflon film was applied to the entire tip surface of the blade using Nitto's Teflon tape Nitoflon (No. 923UT). In Example 8, a cleaning blade was prepared in the same manner as in Example 7 by attaching a film No. 443 made of ultra-high molecular weight polyethylene (UHPE) manufactured by Nitto to the entire tip surface of the blade.

[0110] In Example 9, the underside of the blade was masked with polyimide tape within a range of about 0.5 cm from the ridge of the blade tip, the entire surface of the blade tip was hydrophilized with oxygen plasma, and an organic monolayer of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was formed over the entire surface of the blade tip by thermal chemical vapor deposition (CVD), to produce the cleaning blade of Example 9.

[0111] In Comparative Example 1, the cleaning blade was a cleaning blade in which the base thereof was an elastic member alone, without a coating layer. Comparative Example 2 was prepared under the same conditions as Example 2, except that the underside of the blade was masked with polyimide tape except for an area up to a position 10 μm away from the blade tip ridge, and a coating layer was formed on the underside of the blade within an area of ​​10 μm from the blade tip ridge.

[0112] <Measurement of the average thickness of the coating layer> For the cleaning blades of Examples 1 to 3, 7 to 9 and Comparative Example 2, the average thickness of the coating layer was measured at a position 50 μm from the blade tip ridge on the blade tip surface. The results are shown in Tables 1 and 2. The average thickness was measured by scraping off a part of the coating layer with a spatula or a cotton swab, and measuring the shape with a contact surface roughness meter (Surftest SJ-500, manufactured by Mitutoyo).

[0113] <Assembly of image forming device> The cleaning blades of Examples 1 to 9 and Comparative Examples 1 and 2 were attached to the process cartridge of a color multifunction printer (imagio MP C4500, manufactured by Ricoh Co., Ltd.) (the printer unit has a similar configuration to the image forming apparatus 500 shown in FIG. 3) to assemble the image forming apparatus. In the cleaning blades of Examples 4 to 6 and Comparative Example 1, zinc stearate was applied as a touch-up agent to the area of ​​the blade tip surface where no coating layer was formed, and the area was covered with the touch-up agent. In addition, in the cleaning blades of Examples 1 to 9 and Comparative Examples 1 and 2, zinc stearate was also applied as a touch-up agent to the area of ​​about 0.5 cm from the blade tip ridge on the underside of the blade, and the area was covered with the touch-up agent. The cleaning blade was attached to the image forming apparatus so that the linear pressure was 20 g / cm and the cleaning angle was 79°.

[0114] <Torque rating> Using the above image forming apparatus, output was performed under the following conditions. During output, the drive torque of the image carrier, which was the member to be cleaned, was measured. After output, the edge of the cleaning blade was observed with a laser microscope (LEXT OLS4500, manufactured by Olympus Corporation), and torque evaluation was performed based on the following evaluation criteria. The evaluation results of Examples 1 to 9 and Comparative Examples 1 and 2 are shown in Tables 1 and 2. Note that "initial" in the evaluation criteria refers to the 1st to 500th sheets. Environment: 23℃ / 45%RH Paper feed conditions: Blank chart Output quantity: 5,000 sheets (A4 size landscape) -Evaluation criteria- ⊚: The rate of change in torque increase was within 50% of the initial value, and the image carrier did not stop due to the increase in drive torque. Furthermore, even after printing, there was no sign of curling when the edge of the blade tip was observed. ◯: The rate of change in torque increase was within 50% of the initial value, and the image carrier did not stop due to the increase in drive torque. However, when the edge of the blade tip was observed after printing, there were traces of curling, but the level was not so high that the toner was removed. x: The image carrier stopped due to an increase in torque, and when the edge of the blade was observed after printing, there were traces of curling up to the extent that toner had fallen out. Among the above evaluation criteria, the evaluations of ⊚ and ◯ were judged to be sufficient results for practical use, and the evaluation of × was judged to be insufficient results according to the present invention.

[0115] <Cleaning performance evaluation> Using the above image forming apparatus, output was performed under the following conditions. Thereafter, the blade tip edge of the cleaning blade and the surface of the image carrier, which is the member to be cleaned, were observed with the above laser microscope and evaluated based on the following evaluation criteria. The evaluation results of Examples 1 to 9 and Comparative Examples 1 and 2 are shown in Tables 1 and 2. Environment: 27℃ / 80%RH Paper feed conditions: 5% image area ratio chart printed 3 times / job Output quantity: 50,000 sheets (A4 size landscape) -Evaluation criteria- ◎: The toner that had slipped through due to poor cleaning could not be visually confirmed on the printed paper or on the image carrier, and no streaks of toner were confirmed when observing the image carrier in the longitudinal direction with a microscope. ○: No toner that had slipped through due to poor cleaning was visually observed on the printed paper or on the image carrier. ×: Toner that had slipped through due to poor cleaning was visually confirmed on the printed paper and on the image carrier. Among the above evaluation criteria, the evaluations of ⊚ and ◯ were judged to be sufficient results for practical use, and the evaluation of × was judged to be insufficient results according to the present invention.

[0116] [Table 1]

[0117] [Table 2]

[0118] In Examples 1 to 9, the torque evaluation and cleaning evaluation were rated as "A" or "B", and were sufficient for practical use.

[0119] In Examples 1 to 3, the behavior of the contact portion of the cleaning blade became more stable and the torque evaluation was better as the thickness of the coating layer on the blade tip surface increased. Also, the curvature radius of the contact portion became smaller as the thickness of the coating layer on the blade tip surface decreased, making it more difficult for toner to pass between the cleaning blade and the member to be cleaned, resulting in better cleaning evaluation results.

[0120] In Examples 4 to 6, the smaller the distance from the blade tip ridge to the coating layer on the blade tip surface, the larger the area of ​​the coating layer, which made the behavior of the blade tip ridge more stable and resulted in better results in the torque evaluation and cleaning evaluation.

[0121] In Examples 7 and 8, a film with high slidability was used for the covering layer, and therefore the torque evaluation was better.

[0122] In Example 9, the coating layer was an organic monolayer, which was quite thin for a coating layer, and therefore the cleaning evaluation was better and the torque evaluation was also good.

[0123] In Comparative Example 1, the cleaning blade did not have a coating layer and was coated only with a touch-up agent, so toner was less likely to pass through between the blade and the member being cleaned, and the cleaning evaluation was "A". However, the touch-up agent was easily detached and friction was easily increased, so the torque evaluation was "X".

[0124] In comparison example 2, there is a coating layer on the underside of the blade that comes into contact with the member being cleaned (within a 10 μm range from the blade tip ridge), so the behavior of the part of the blade that comes into contact tends to be stable and the torque evaluation was "◎". However, because the coating layer is only present locally on the underside of the blade within a 10 μm range from the blade tip ridge, this thick part acts like a cliff, making it easy for toner to slip through between the blade and the member being cleaned, and the cleaning evaluation was "X".

[0125] From the above, it was demonstrated that a cleaning blade satisfying the configuration of the present invention can suppress an increase in torque even immediately after starting use, and can provide good cleaning performance.

[0126] For example, aspects of the present invention are as follows. <1> A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned to remove residues on the surface of the member to be cleaned, the cleaning blade has a coating layer on a blade tip surface that comes into contact with the member to be cleaned, and does not have the coating layer on a blade lower surface that is perpendicular to the blade tip surface; The coating layer is present at least in a portion of the cleaning blade that contacts the member to be cleaned. <2> The coating layer is present on the entire surface of the blade tip surface or on a part of the blade tip surface, in a range from a position up to 900 μm away from the blade tip ridge line to an end of the blade tip surface opposite the blade tip ridge line. <1> The cleaning blade according to claim 1 . <3> The blade tip surface is coated with a touch-up agent in a region where the coating layer is not present and in the lower surface of the blade. <1> or <2> The cleaning blade according to claim 1 . <4> The coating layer is a film containing polytetrafluoroethylene (PTFE) fine particles and a fluorine-based resin as a binding component, a film of Teflon (registered trademark) or ultra-high molecular weight polyethylene, or an organic monolayer having a perfluoroalkyl chain. <1> from <3> 2. The cleaning blade according to claim 1 , <5> The film containing the polytetrafluoroethylene (PTFE) fine particles and the fluorine-based resin as a binding component has an average thickness of 10 μm or less at a position 50 μm from the blade tip ridge. <4> The cleaning blade according to claim 1 . <6> The blade substrate of the cleaning blade has a single-layer structure of an elastic member containing polyurethane rubber or polyurethane elastomer, or a laminate structure of a plurality of elastic members having different Martens hardness or JIS-A hardness. <1> from <5> 2. The cleaning blade according to claim 1 , <7> The fluorine-based resin as the binder component contains a terpolymer consisting of vinylidene fluoride (VdF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE), and the molar ratio of VdF monomer units, HFP monomer units, and TFE monomer units in the terpolymer, VdF / HFP / TFE, is 30 to 80 mol % / 10 to 35 mol % / 5 to 35 mol %. <4> from <6> 2. The cleaning blade according to claim 1 , <8> The image carrier has at least one of a charging unit for charging the surface of the image carrier, an exposure unit for exposing the charged surface of the image carrier to light to form an electrostatic latent image, a developing unit for developing the electrostatic latent image into a toner image, and a transfer unit for transferring the toner image to a recording medium, and a cleaning unit for contacting the surface of the image carrier to remove residues on the surface of the image carrier, the cleaning unit being <1> from <7> 2. A process cartridge having the cleaning blade according to claim 1 . <9> an image carrier; a charging unit for charging the surface of the image carrier; an exposure unit for exposing the charged surface of the image carrier to light to form an electrostatic latent image; a developing unit for developing the electrostatic latent image into a toner image; a transfer unit for transferring the toner image to a recording medium; a fixing unit for fixing the toner image transferred to the recording medium; and a cleaning unit for contacting the surface of the image carrier to remove residues on the surface of the image carrier, the cleaning unit being <1> from <7> 2. An image forming apparatus comprising the cleaning blade according to claim 1 .

[0127] the above <1> from <7> Any of the cleaning blades listed above <8> The process cartridge of <9> According to this image forming apparatus, the conventional problems can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0128] 3 Image carrier 14 Intermediate transfer belt 60 Transcription Unit 62 Cleaning blade 62a Blade tip surface 62b Underside of blade 62c Blade tip ridge 62d coating layer 80 Fuser unit 500 Image forming device 621 Support member 622 Blade Base 623 Blade back [Prior art documents] [Patent documents]

[0129] [Patent Document 1] Japanese Patent Application Publication No. 8-220962 [Patent Document 2] JP 2000-147972 A [Patent Document 3] Japanese Patent Application Publication No. 6-348193 [Patent Document 4] JP 2017-16083 A [Patent Document 5] Patent No. 2853598

Claims

1. A cleaning blade having an elastic member that comes into contact with a surface of a member to be cleaned to remove residues on the surface of the member to be cleaned, the cleaning blade has a coating layer on a blade tip surface that comes into contact with the member to be cleaned, and does not have the coating layer on a blade lower surface that is perpendicular to the blade tip surface; The coating layer is present at least in a portion of the cleaning blade that contacts the member to be cleaned.

2. The coating layer is the entire surface of the blade tip surface, or 2. The cleaning blade according to claim 1, wherein the part of the blade tip surface is present in a range from a position up to 900 μm away from the blade tip ridge line to an end of the blade tip surface facing the blade tip ridge line.

3. 3. The cleaning blade according to claim 1, wherein a region of the blade tip surface where the coating layer is not present and the lower surface of the blade are coated with a touch-up agent.

4. 3. The cleaning blade according to claim 1, wherein the coating layer is a film containing polytetrafluoroethylene (PTFE) fine particles and a fluorine-based resin as a binding component, a Teflon (registered trademark) or ultra-high molecular weight polyethylene film, or an organic monomolecular film having a perfluoroalkyl chain.

5. 5. The cleaning blade according to claim 4, wherein the film containing the polytetrafluoroethylene (PTFE) fine particles and the fluorine-based resin as a binding component has an average thickness of 10 [mu]m or less at a position 50 [mu]m away from the edge of the blade tip.

6. 3. The cleaning blade according to claim 1, wherein the blade substrate of the cleaning blade has a single layer structure of an elastic member containing polyurethane rubber or polyurethane elastomer, or a laminate structure of a plurality of such elastic members having different Martens hardness or JIS-A hardness.

7. The fluorine-based resin, which is the binder component, contains a ternary copolymer made of vinylidene fluoride (VdF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE), 5. The cleaning blade according to claim 4, wherein the molar ratio of the VdF monomer unit, the HFP monomer unit, and the TFE monomer unit in the terpolymer, VdF / HFP / TFE, is 30-80 mol % / 10-35 mol % / 5-35 mol %.

8. An image carrier; At least one of a charging means for charging a surface of the image carrier, an exposure means for exposing the charged surface of the image carrier to light to form an electrostatic latent image, a developing means for developing the electrostatic latent image into a toner image, and a transfer means for transferring the toner image onto a recording medium; a cleaning means for contacting the surface of the image carrier to remove residues on the surface of the image carrier; 3. A process cartridge, wherein the cleaning means comprises the cleaning blade according to claim 1.

9. An image carrier; a charging means for charging the surface of the image carrier; an exposure unit for exposing the charged surface of the image carrier to light to form an electrostatic latent image; a developing means for developing the electrostatic latent image into a toner image; a transfer means for transferring the toner image onto a recording medium; a fixing unit for fixing the toner image transferred onto the recording medium; a cleaning means for contacting the surface of the image carrier to remove residues on the surface of the image carrier; 3. An image forming apparatus, wherein the cleaning means comprises the cleaning blade according to claim 1.

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