Cleaning blade, cleaning device and process cartridge

Abstract

To provide a cleaning blade and process cartridge, which offer both curling resistance and cleaning performance of a cleaning blade in high-speed image forming.SOLUTION: A cleaning blade for use in an image forming device with a mechanism for cleaning an image carrier surface is provided, the cleaning blade having a region with a fluid first lubricant provided on each end thereof in a longitudinal direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cleaning blade, a cleaning device, and a process cartridge, and more particularly to a cleaning blade, a cleaning device, and a process cartridge that can achieve both resistance to curling of the cleaning blade and cleaning performance during high-speed image formation. [Background technology]

[0002] In recent high-speed image formation, for example, when forming an electrophotographic image, there is a process in which a toner image is formed on an image carrier and the toner image on the image carrier is transferred repeatedly. During this process, some toner remains on the image carrier without being completely transferred, and means for removing this include fur brushes and blades, with cleaning blades nowadays being the main means.

[0003] Typically, the longitudinal length of a cleaning blade is designed to be sufficiently longer than the area where a toner image is formed on the image carrier (inside the image forming area), since it is necessary to also clean scattered toner in areas where no toner image is formed on the image carrier (outside the image forming area).However, since there is less toner and external additives in areas where no toner image is formed on the image carrier (outside the image forming area), there is a problem that the cleaning blade is prone to curling up.

[0004] Therefore, in order to prevent the cleaning blade from turning up, a cleaning blade has been proposed that has a resin film on the surface at least at both ends outside the development area (image forming area) in the longitudinal direction (Patent Document 1). However, there is a problem in that toner and free external additives slip through the boundary between the area with the resin film and the area without the resin film, which raises concerns about cleanability.

[0005] In addition, a cleaning blade has been proposed in which both ends of a cleaning blade are impregnated with an isocyanate compound to cause swelling, and the difference in level between the treated and untreated areas impregnated with the isocyanate compound is controlled to within a range of 5 to 30 μm, thereby suppressing curling of the cleaning blade and simultaneously realizing good cleaning performance (Patent Document 2). However, in recent years, with the increasing speed of image formation, the torque between the image carrier and the cleaning blade has increased, so that impregnation treatment of both ends of the cleaning blade alone is insufficient to prevent curling, and there is a problem that poor cleaning occurs due to a slight difference in level between the treated and untreated areas.

[0006] For these reasons, in recent high-speed image formation, further improvements are required to achieve both resistance to curling of the cleaning blade and cleaning performance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-162885 [Patent Document 2] Japanese Patent Application Publication No. 2010-170157 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above problems and circumstances, and the problem to be solved is to provide a cleaning blade, a cleaning device, and a process cartridge that can achieve both resistance to cleaning blade curling and cleaning performance during high-speed image formation. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems, the inventors investigated the causes of the above-mentioned problems and found that the above-mentioned problems can be solved by providing a cleaning blade having areas where a fluid lubricant is present at both ends in the longitudinal direction, thereby arriving at the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.

[0010] 1. A cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, The cleaning blade has a region where a first lubricant having fluidity is present at both ends in the longitudinal direction. death, the first lubricant present in the regions at both ends is grease; the first lubricant present in the regions at both ends contains a silicone resin component; The region of each of the two ends where the first lubricant is present is a region of 4 to 8% of the entire length in the longitudinal direction from the end of each of the two ends toward the center. R A cleaning blade characterized by:

[0014] 2 The first lubricant is characterized in that it has a region in the center in the longitudinal direction where a second lubricant different from the first lubricant present in the regions at both ends is present. In the section The cleaning blade described.

[0017] 3 A cleaning device provided in an image forming apparatus and having a mechanism for cleaning the surface of an image bearing member, or No. In item 2 A cleaning device comprising the cleaning blade described above.

[0018] 4 A process cartridge that is detachable from the image forming apparatus main body, 3 2. A process cartridge comprising the cleaning device according to claim 1. [Effects of the Invention]

[0019] The above-described means of the present invention can provide a cleaning blade, a cleaning device, and a process cartridge that can achieve both resistance to curling of the cleaning blade and cleaning performance in high-speed image formation. The mechanism by which the effects of the present invention are manifested or the mechanism of action is not clear, but is speculated as follows.

[0020] The present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present.

[0021] As described above, it has been difficult to achieve both curling resistance and cleaning performance in conventional cleaning blades that have at least a resin film on the surface of both ends outside the image forming area in the longitudinal direction, or cleaning blades that have both ends impregnated with an isocyanate compound.

[0022] The cleaning blade of the present invention has regions at both longitudinal ends where a first lubricant having fluidity is present, and when the cleaning blade is used to remove toner that has not been completely transferred and remains on the image carrier, the first lubricant present at both longitudinal ends wets and spreads from the contact point, providing uniform lubrication, and since there is no extreme difference in the boundary between the areas where the first lubricant is present and the areas where it is not present, cleaning performance can be maintained for a long period of time.

[0023] Furthermore, the first lubricant is transferred from the cleaning blade to the image bearing member, thereby synergistically reducing the torque between the image bearing member and the cleaning blade.

[0024] Furthermore, because the first lubricant is present at both longitudinal ends of the cleaning blade, it can fill in areas where there is little toner or external additives in areas where a toner image is not normally formed on the image carrier (outside the image forming area), thereby maintaining the cleaning blade's resistance to curling without causing toner slip-through or image defects. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram showing an example of an area where lubricant is applied to a cleaning blade; [Figure 2] (a) A diagram showing an example of a normal contact state between an image carrier and a cleaning blade (counter type). (b) A diagram showing an example of a normal contact state between an image carrier and a cleaning blade (with type). [Figure 3] Schematic cross-sectional view showing the structure of a tandem-type electrophotographic image forming apparatus equipped with an image carrier. [Figure 4] FIG. 1 is a diagram illustrating an example of a configuration of a main part of an image forming unit (process cartridge). [Figure 5] Schematic diagram for explaining the cleaning blade evaluation method (test image consisting of a vertical band-shaped solid image with 80% coverage) [Figure 6] Schematic diagram for explaining the cleaning blade evaluation method (test image consisting of a vertical band-shaped solid image with 10% coverage) DETAILED DESCRIPTION OF THE INVENTION

[0026] The cleaning blade of the present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, and is characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present. This feature is a technical feature common to or corresponding to each of the following embodiments (modes).

[0027] In an embodiment of the present invention, it is preferable that the first lubricant present in the regions at both ends is liquid from the viewpoint of maintaining the migration, spreadability and lubricity of the lubricant.

[0028] It is preferable that the first lubricant present in the regions at both ends is grease, since this does not spread too much and contributes to maintaining lubricity.

[0029] It is preferable that the first lubricant present in the regions at both ends contains a silicone resin component from the viewpoint of the lubricity of the lubricant itself.

[0030] It is preferable to have a region in the center of the longitudinal direction where a second lubricant of a type different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0031] It is preferable that the regions at both ends where the first lubricant is present be regions extending from the ends of the both ends toward the center portion to 8% or less of the total longitudinal length, from the viewpoint of maintaining the wetting and spreading of the first lubricant and uniform lubrication.

[0032] It is more preferable that the regions at both ends where the first lubricant is present be regions extending from the ends of the both ends toward the center portion to 5% or less of the total longitudinal length, from the viewpoint of maintaining the wetting and spreading of the first lubricant and uniform lubrication.

[0033] The cleaning device of the present invention is provided in an image forming apparatus and has a mechanism for cleaning the surface of an image bearing member, and is characterized by including the cleaning blade described in any one of items 1 to 7. This makes it possible to achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0034] The process cartridge of the present invention is a process cartridge detachable from the main body of an image forming apparatus, and is characterized by including the cleaning device described in item 8. This makes it possible to achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0035] The present invention, its components, and embodiments for carrying out the present invention will be described in detail below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits.

[0036] [Outline of the cleaning blade of the present invention] The cleaning blade of the present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, and is characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present. In the present invention, the term "image carrier" includes both a "photosensitive member" and an "intermediate transfer belt."

[0037] The cleaning blade of the present invention has regions at both longitudinal ends where a first lubricant having fluidity is present, and when the cleaning blade is used to remove toner that has not been completely transferred and remains on the image carrier, the first lubricant present at both longitudinal ends wets and spreads from the contact point, providing uniform lubrication, and since there is no extreme difference in the boundary between the areas where the first lubricant is present and the areas where it is not present, cleaning performance can be maintained for a long period of time.

[0038] Furthermore, the first lubricant is transferred from the cleaning blade to the image bearing member, thereby synergistically reducing the torque between the image bearing member and the cleaning blade.

[0039] Furthermore, because the first lubricant is present at both longitudinal ends of the cleaning blade, it can fill in areas where there is little toner or external additives in areas where a toner image is not normally formed on the image carrier (outside the image forming area), thereby maintaining the cleaning blade's resistance to curling without causing toner slip-through or image defects.

[0040] (Definition of both ends and center) In the present invention, "both longitudinal ends of the cleaning blade" refers to the area within a range of 10% of the total length in the longitudinal direction from both longitudinal ends of the cleaning blade toward the center.

[0041] In the present invention, the "central portion of the cleaning blade in the longitudinal direction" refers to the 80% region outside the range of 10% of the total length in the longitudinal direction from both ends of the cleaning blade toward the central portion.

[0042] (Areas where the first lubricant and the second lubricant having fluidity are applied) FIG. 1 is a diagram showing an example of an area where a lubricant is applied to a cleaning blade. The first lubricant having flowability according to the present invention is applied to the end region EP of the cleaning blade (CL) by the method described above. In FIG. 1, the first lubricant is present in the end regions EP, which correspond to the "longitudinal ends of the cleaning blade." This first lubricant spreads from the contact point, providing uniform lubrication, and also eliminating the extreme boundary difference between the areas where the first lubricant is present and the areas where it is not present, thereby enabling the cleaning performance to be maintained for a long period of time.

[0043] Furthermore, the first lubricant is transferred from the cleaning blade to the image carrier Y, thereby synergistically reducing the torque between the image carrier Y and the cleaning blade (CL).

[0044] Furthermore, since the first lubricant is present at both longitudinal ends of the cleaning blade (CL), it can fill in areas where there is little toner or external additives in areas where a toner image is not normally formed on the image carrier Y (outside the image forming area), thereby maintaining the cleaning blade's resistance to curling without causing toner slip-through or image defects.

[0045] The second lubricant according to the present invention, which is different in type from the first lubricant, is supplied to the central region CP of the cleaning blade (CL) by the method described above, and is applied by the brush roller 121, for example. In FIG. 1, the second lubricant is applied to the central region CP, which corresponds to the "central portion of the cleaning blade in the longitudinal direction," but the second lubricant may also be applied to the end regions EP or may spread therethrough, thereby reducing wear between the image carrier Y and the cleaning blade and improving durability.

[0046] (Cleaning blade peeling) 2(a) and 2(b) are diagrams showing an example of a contact state between an image carrier and a cleaning blade, for explaining "curling of the cleaning blade." FIG. 2(a) is a diagram showing the normal contact state between an image carrier and a cleaning blade in the counter system, and FIG. 2(b) is a diagram showing the normal contact state between an image carrier and a cleaning blade in the with system. The "normal contact state" between the image carrier and the cleaning blade refers to a contact state between the image carrier and the cleaning blade in a state where the "cleaning blade is not turned up."

[0047] Normally, when the cleaning blade (CL) removes toner remaining on the image carrier, one or more of edge 1, surface A (SA), and surface B (SB) of the cleaning blade are in contact with the image carrier, as shown in Figures 2(a) and 2(b).

[0048] "Cleaning blade curling" refers to the cleaning blade turning over, where one or more of edge 1 (E1), surface A (SA), and surface B (SB) of the cleaning blade are pulled in the driving direction of the image carrier (Y), causing either edge 2 (E2) or surface C (SC), or both, to come into contact with the image carrier.

[0049] Normally, when the cleaning blade (CL) is used to remove toner remaining on the image carrier, as shown in Figure 2(a), the cleaning blade is in contact with the image carrier so that a force is applied in the counter direction to the rotation direction of the image carrier. As a result, the frictional force between the image carrier (Y) and the cleaning blade (CL) becomes excessive, and edge 1 (E1) of the cleaning blade (CL) may be reversed in the rotation direction of the image carrier (Y), causing the cleaning blade to turn over.

[0050] Furthermore, since the cleaning blade (CL) is also required to clean scattered toner in areas on the image carrier (Y) where no toner image is formed (outside the image forming area), the longitudinal length of the cleaning blade (CL) is designed to be sufficiently longer than the areas on the image carrier (Y) where a toner image is formed (inside the image forming area). However, since there is less toner and external additives in the areas on the image carrier (Y) where no toner image is formed (outside the image forming area), and furthermore, since the support member is only on one side, curling often occurs starting from one end or both ends of the cleaning blade (CL).

[0051] 1. Cleaning blade (1.1) Lubricant applied to the cleaning blade The cleaning blade of the present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, and is characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present. The cleaning blade of the present invention can be produced, for example, by applying a first lubricant having flowability to a cleaning blade molded by a known polyurethane molding method described below.

[0052] (1.1.1) First lubricant having flowability In the present invention, the "first lubricant having fluidity" refers to a lubricant that is not fixed to a specific site and that can move and spread from the site where the lubricant was initially present when an external force is applied. A fluid lubricant has the property that when another member comes into contact with a member to which the lubricant is to be applied, the lubricant can be transferred to the member with which the lubricant comes into contact. Due to the above properties, no step occurs between the treated and untreated areas, and cleaning defects due to the step do not occur.

[0053] In the present invention, "fluidity" refers to the property of liquid or powder moving like a flow at a pressure close to the contact pressure of the cleaning blade.

[0054] The form of the first lubricant having flowability according to the present invention may be, for example, a liquid (including semi-solid forms in the present invention) or a powder.

[0055] (liquid lubricant) In an embodiment of the present invention, it is preferable that the first lubricant present in the regions at both ends is liquid from the viewpoint of maintaining the migration, spreadability and lubricity of the lubricant.

[0056] Liquid lubricants include grease and oil. Grease is preferred from the viewpoint that a relatively high viscosity can appropriately suppress the spreading of the liquid lubricant and contribute to maintaining lubricity. Furthermore, it is preferable that the first lubricant present in the regions at both ends contains a silicone resin component from the viewpoint of the lubricity of the lubricant itself.

[0057] 〔grease〕 It is preferable that the first lubricant present in the regions at both ends is grease, as this can appropriately suppress spreading and contribute to maintaining lubricity. In the present invention, "grease" refers to a lubricant in which fine solids called thickeners are dispersed in a liquid lubricant (base oil) to form a semi-solid lubricant that is uniformly mixed.

[0058] Examples of the grease include known greases such as fluorine-based grease, silicone grease, and fluorosilicone grease. Specific examples include Sumitec F936 (manufactured by Sumiko Lubricant Co., Ltd.), G501 (manufactured by Shin-Etsu Chemical Co., Ltd.), and FG-721-1 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0059] 〔oil〕 Examples of oils include mineral oils, synthetic oils, fluorine-based oils, and silicone oils. Specifically, these include PFPE oil (perfluoropolyether), CTFE oil (a low polymer of chlorotrifluoroethylene), PTFE oil (polytetrafluoroethylene), dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone, reactive silicone oil, and non-reactive silicone oil, and examples thereof include "Demnum" manufactured by Daikin Industries, Ltd. and "KF-96" manufactured by Shin-Etsu Chemical Co., Ltd.

[0060] (powder lubricant) Examples of powder lubricants include fine silicone particles and metal salts of fatty acids. Specifically, Tospearl (manufactured by Momentive Performance Materials Japan LLC) can be mentioned.

[0061] (1.1.2) Region where the first lubricant having fluidity is present and its measurement method From the viewpoint of fully obtaining the effects of the first lubricant, it is preferable that the region where the first lubricant having fluidity according to the present invention is present is a region extending from both longitudinal ends of the cleaning blade toward the center portion to 8% or less of the total longitudinal length, and more preferably 5% or less.

[0062] If the area where the lubricant is present is too narrow, the effect of the lubricant cannot be obtained sufficiently, and curling of the cleaning blade cannot be suppressed. On the other hand, if the area where the lubricant is present is too large, the effect of suppressing cleaning blade curling can be obtained, but there is a possibility of toner fogging in non-image areas or image defects occurring due to toner or external additives slipping through the cleaning blade in image areas.

[0063] The area where the fluid first lubricant is present in the edge area of ​​the cleaning blade can be visually confirmed. The percentage of the total length of the region in the longitudinal direction that the region represents can be determined by measuring the longitudinal length of the region where the first lubricant is present, which is visually confirmed, and calculating the ratio of the region to the total length of the cleaning blade in the longitudinal direction.

[0064] (1.1.3) Method for applying first lubricant having fluidity The timing of application of the first lubricant having fluidity to both longitudinal ends of the cleaning blade may be, for example, (a) the first lubricant having fluidity may be applied to the cleaning blade in advance, or (b) the first lubricant having fluidity may be applied to the cleaning blade by supplying it from another component within the cleaning device, image forming apparatus, or process cartridge. It is preferable not to apply the first lubricant having fluidity to the central portion of the cleaning blade in advance in terms of spreading and uniform lubrication of the first lubricant.

[0065] (Method of applying a first lubricant with fluidity in advance) Examples of methods for applying the first lubricant in advance include dipping, pressing cotton or cloth against the surface, applying with a paintbrush, brush, roller, or the like, and applying with a micropipette or dispenser. Among the above methods, application methods using a micropipette or a dispenser are particularly preferred from the viewpoint of controllability of the amount of lubricant applied.

[0066] (Method of applying a first lubricant having fluidity from another member) The lubricant may be supplied from a lubricant supplying member in contact with the cleaning blade, or from the lubricant supplying member via a member in contact with the cleaning blade.

[0067] (1.1.4) Second Lubricant In the present invention, the "second lubricant" refers to a lubricant that is provided as standard in an image forming apparatus, and is supplied to the surface of the image carrier (by application with a lubricant application brush or by external addition of lubricant to toner), and the lubricant on the image carrier is transferred to the cleaning blade. The lubricant is chemically different in type from the first lubricant having fluidity according to the present invention, and refers to a lubricant supplied from another member to the central portion of the cleaning blade in the longitudinal direction. The presence of the second lubricant in the central portion improves the lubricity of the surface of the cleaning blade.

[0068] It is preferable that the cleaning blade according to the present invention has a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0069] The type of the second lubricant is not particularly limited and can be selected appropriately from known lubricants, but solid lubricants are particularly preferred, and those containing fatty acid metal salts are preferred. The solid lubricant can be applied by bringing a lubricant application brush into contact with the image carrier in the image forming apparatus and driving the brush in accordance with the driving of the image carrier.

[0070] The fatty acid metal salt is preferably a metal salt of a saturated or unsaturated fatty acid having 10 or more carbon atoms, and examples thereof include zinc laurate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc stearate, aluminum stearate, indium stearate, potassium stearate, lithium stearate, sodium stearate, zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, aluminum oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, lead caprate, zinc linoleate, cobalt linoleate, calcium linoleate, zinc ricinoleate, and cadmium ricinoleate. Among these, zinc stearate is particularly preferred from the viewpoints of its effect as a second lubricant (improving the lubricity of the surface of the cleaning blade), availability, cost, and the like.

[0071] (1.2) Cleaning Blade Configuration The cleaning blade according to the present invention is mainly composed of a rubber material and a support member. The rubber material does not need to be the same material, and the blade may be made of two layers, for example, a contact layer that forms the edge portion and a support layer. In the case of a two-layer structure, for example, the material of the support layer may have a lower permanent deformation rate than the material of the contact layer in order to prevent settling.

[0072] (1.2.1) Rubber materials The rubber material is preferably urethane rubber, ie, polyurethane, from the viewpoint of abrasion resistance and moldability. The polyurethane may be obtained by using, for example, polyol and polyisocyanate as raw materials and reacting them with a crosslinking agent as needed. The polyurethane may have a single layer structure, or may have a multi-layer structure in which, for example, the polyurethane of the base layer and the polyurethane of the edge layer are different and these are laminated.

[0073] (Polyol) As the polyol, polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol can be used. More specifically, examples include polyethylene adipate, polybutylene adipate, and polyethylene butylene adipate, but other materials may also be used. The polyols may be used alone or in combination of two or more.

[0074] (Isocyanate) Examples of isocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, and isomers thereof, but other isocyanates may also be used. The isocyanates may be used alone or in combination of two or more.

[0075] (Crosslinking agent) The crosslinking agent is preferably a mixture of a low molecular weight diol and a low molecular weight triol. Examples of low molecular weight diols include 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, and neopentyl glycol, but other diols may also be used. Examples of low molecular weight triols include trimethylolpropane and triisopropanolamine, but other triols may also be used.

[0076] (hardness) The rubber hardness of the cleaning blade according to the present invention is preferably within the range of 65 to 85° in terms of the hardness value defined by JIS-A. If the rubber hardness is 65° or more, the blade will not be easily retracted and the wedge angle will not become too small. Furthermore, if the rubber hardness is 85° or less, the surface pressure will not be too high and the abrasive force will not be too strong, and the fatty acid metal salt will not be easily removed, so that a sufficient lubricating effect can be obtained.

[0077] (1.2.2) Supporting member The support member is not particularly limited, and any conventionally known member can be used, including, for example, those made of rigid metal, elastic metal, plastic, ceramic, and the like. Among these, rigid metals are preferred.

[0078] (1.2.3) Contact conditions The contact force of the cleaning blade according to the present invention is preferably within the range of 12 to 30 (N / m) from the viewpoint of preventing incomplete wiping and curling.

[0079] (1.3) Cleaning Blade Manufacturing Method The cleaning blade of the present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, and is characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present.

[0080] The cleaning blade according to the present invention is produced by first preparing a rubber sheet as described below, and then applying a fluid first lubricant to the cleaning blade formed by a known polyurethane forming method.

[0081] (1.3.1) Rubber material: Preparation of rubber sheet The rubber sheet of the cleaning blade according to the present invention is produced by a known polyurethane molding method, for example, as follows. (Prepolymer formation) First, the polyol and isocyanate are dehydrated, and then mixed and reacted at a temperature in the range of 70 to 140° C. for 10 to 120 minutes to form a prepolymer.

[0082] (Addition of cross-linking agent) Thereafter, a crosslinking agent and the like are added to the prepolymer. The crosslinking agent is preferably a mixture of a low molecular weight diol and a low molecular weight triol.

[0083] (Prepolymer hardening) After adding a crosslinking agent to the prepolymer, the mixture is poured into a mold of a centrifugal molding machine preheated to, for example, 150°C, and cured for 5 to 10 minutes to produce a rubber sheet. The thickness of the sheet is, for example, within the range of 0.6 to 2.0 mm.

[0084] (1.3.2) Rubber material: Cutting and gluing rubber sheets The rubber sheet produced by the above process is cut vertically with a blade to a size of 340 mm x 14.0 mm. Thereafter, the blade is heat-bonded to a metal plate with a bonding margin of 4 mm using a thermosetting adhesive to prepare a cleaning blade with a free length of 10.0 mm.

[0085] (1.3.3) Application of a first fluid lubricant A first lubricant having fluidity is applied to both longitudinal ends of the cleaning blade obtained by the above process. The application method is as described above.

[0086] 2.Cleaning device The cleaning device of the present invention is provided in an image forming apparatus and has a mechanism for cleaning the surface of an image bearing member, and is characterized by including the cleaning blade described above. This makes it possible to achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0087] The cleaning device of the present invention is characterized by including the cleaning blade of the present invention, but may be configured to include various parts or members depending on the purpose. For example, it is preferable to provide a lubricant, a lubricant supply means, and a lubricant application means including a lubricant application brush roller. It is also preferable to provide a developer recovery container for storing developer containing toner and the like removed by the cleaning means.

[0088] The cleaning device of the present invention is suitably used in an image forming apparatus having a mechanism for cleaning the surface of an image bearing member. The image forming apparatus is not particularly limited as long as it has a mechanism for cleaning the surface of an image carrier, but as an example, we will explain a cleaning device provided in a tandem type image forming apparatus equipped with an image carrier (electrophotographic photosensitive member).

[0089] FIG. 3 is a cross-sectional view showing the structure of a tandem image forming apparatus equipped with an image carrier.

[0090] There are two types of cleaning devices according to the present invention, for example, a "cleaning device 6b" provided in the unit of the "endless belt-like intermediate transfer body 70" and a "cleaning device 6Y" provided in the "image forming unit (process cartridge) 10Y", and the cleaning blades provided in both devices may be the same. The cleaning device 6Y includes a cleaning blade. A brush roller may be provided upstream of the cleaning blade.

[0091] The lubricant supplying section 116Y supplies the second lubricant described above to the surface of the photoreceptor 1Y, and supplies (applies) it to a cleaning blade provided in a cleaning device via the photoreceptor 1Y. The lubricant supply unit 116Y is provided, for example, downstream of the primary transfer roller 5Y and upstream of the cleaning device 6Y. The lubricant supply unit 116Y may be located at another position, for example, downstream of the cleaning device 6Y. The lubricant supply unit 116Y includes a brush roller 121, a solid second lubricant 122, and a pressure spring 123.

[0092] The brush roller 121 applies the second lubricant 122 to the surface of the photoreceptor 1Y. The brush roller 121 is formed by, for example, forming a pile fabric into a ribbon-like fabric by weaving bundles of fibers into a base fabric as pile yarns, and then spirally winding and adhering the fabric around a metal shaft with the raised surface facing outward. In this brush roller 121, brush fibers made of resin such as polypropylene are densely embedded in a long woven fabric, and this woven fabric is provided on the circumferential surface of the roller base.

[0093] It is preferable to use straight bristles for the brush bristles in terms of the ability to apply the second lubricant. The straight hair type has the hair brushed perpendicular to the metal shaft. The thread used for the brush bristles is preferably a filament thread, and examples of the material include polyamides such as 6-nylon and 12-nylon, polyester, acrylic resin, vinylon, and other synthetic resins, and metals such as carbon and nickel may be kneaded into the thread to increase conductivity.

[0094] The thickness of the brush fibers is, for example, 3 to 7 denier, the hair length of the brush fibers is, for example, in the range of 2 to 5 mm, and the electrical resistivity of the brush fibers is, for example, 1×10 10 Ω or less, Young's modulus of brush fiber is 4900~9800N / mm 2Within this range, the planting density of the brush fibers (number of brush fibers per unit area) is, for example, 50 to 200,000 fibers / square inch (50 to 200k fibers / inch 2 ) is preferred. The amount of penetration of the brush roller 121 into the photosensitive element 1Y is preferably within the range of 0.5 to 1.5 mm. The rotation speed of the brush roller 121 is, for example, within a range of 0.3 to 1.5 in terms of the peripheral speed ratio to the photosensitive member 1Y. The rotation direction of the brush roller 121 may be either the same as or opposite to the rotation direction of the photosensitive member 1Y.

[0095] The pressure spring 123 presses the brush roller 121 against the photosensitive element 1Y via the second lubricant 122. For example, the pressure spring 123 presses the second lubricant 122 so that the pressing force of the brush roller 121 against the photosensitive element 1Y is within a range of 0.5 to 1.0 N.

[0096] In the lubricant supply unit 116Y, for example, the pressing force of the second lubricant 122 against the brush roller 121 and the rotation speed of the brush roller 121 are adjusted in order to adjust the consumption amount of the second lubricant 122 within a desired range. For example, the amount of second lubricant 122 consumed per 1 km of cumulative length of the surface of the photoreceptor 1Y is preferably within a range of 0.04 to 0.27 g / km, and more preferably within a range of 0.04 to 0.15 g / km.

[0097] The above describes the lubricant supply unit 116Y that applies a solid second lubricant 122 to the surface of the photosensitive member 1Y using a brush roller 121, but the lubricant supply unit 116Y may also externally add a fine powder lubricant to the toner base particles when producing the toner. In the lubricant supplying section 116Y, the second lubricant is supplied to the surface of the photoreceptor 1Y by the action of the developing electric field formed in the developing section 4Y.

[0098] The cleaning device 6Y includes a cleaning blade 61 and a screw 62. The cleaning blade 61 is a flat plate-shaped member that comes into contact with the surface of the photoreceptor 1Y to clean the surface of the photoreceptor 1Y. The cleaning blade 61 has a flat plate shape extending in the direction of the rotation axis of the photoreceptor 1Y. The cleaning blade 61 abuts against the photoreceptor 1Y in the counter direction to the rotation direction of the photoreceptor 1Y. The cleaning blade 61 presses against the surface of the photoreceptor 1Y, thereby scraping off toner (residual toner) remaining on the surface of the photoreceptor 1Y after transfer. The remaining toner and the like scraped off from the surface of the photoreceptor 1Y is discharged to the outside of the image forming apparatus 100 by, for example, a screw 62. Together with the cleaning blade 61, a brush roller 121 may scrape off the remaining toner on the surface of the photoreceptor 1Y.

[0099] It is preferable that the cleaning blade 61 maintains stable contact with the surface of the photoreceptor 1Y even when the environment in which it is used, such as temperature, humidity, and frequency, fluctuates. This prevents the cleaning performance from decreasing, making it easier to maintain the desired cleaning performance.

[0100] 3. Process cartridge The process cartridge according to the present invention is a process cartridge detachable from the main body of an image forming apparatus, and is characterized by including the cleaning device described above. This makes it possible to achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0101] (3.1) Process Cartridge Configuration The process cartridge of the present invention is characterized by being equipped with the cleaning blade or cleaning device of the present invention described above, and may have various configurations depending on the purpose. For example, it is preferable to have a configuration including a photosensitive member as an image carrier, a charging means, an exposure means, a developing means, a primary transfer means, a secondary transfer means, and the like.

[0102] The process cartridge of the present invention is suitably used in an image forming apparatus having a mechanism for cleaning the surface of an image bearing member. The image forming apparatus is not particularly limited as long as it has a mechanism for cleaning the surface of an image carrier, but as an example, we will explain a process cartridge installed in a tandem type image forming apparatus equipped with an image carrier (electrophotographic photosensitive member).

[0103] The four process cartridges (image forming units) 10Y, 10M, 10C, and 10Bk are composed of photosensitive members 1Y, 1M, 1C, and 1Bk at the center, charging means 2Y, 2M, 2C, and 2Bk, exposure means 3Y, 3M, 3C, and 3Bk, rotating developing means 4Y, 4M, 4C, and 4Bk, primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means, and cleaning devices 6Y, 6M, 6C, and 6Bk that clean the photosensitive members 1Y, 1M, 1C, and 1Bk.

[0104] The images of each color formed by the process cartridges (image forming units) 10Y, 10M, 10C, and 10Bk are transferred successively onto a rotating endless belt-like intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means, to form a composite color image. The transfer material (image support carrying the fixed final image: for example, plain paper, transparent sheet, etc.) P stored in the paper feed cassette 20 is fed by the paper feed section 21, and is transported via a plurality of intermediate rollers 22A, 22B, 22C, 22D and a resist roller 23 to a secondary transfer roller 5b as a secondary transfer means, where the color image is transferred all at once by secondary transfer onto the transfer material P. The transfer material P onto which the color image has been transferred is subjected to a fixing process by a fixing section 24, and is then sandwiched between paper discharge rollers 25 and placed on a paper discharge tray 26 outside the apparatus. Here, the intermediate transfer body onto which the image formed on the photosensitive member is transferred, the transfer material, and other transfer supports for the toner image are collectively called transfer media.

[0105] On the other hand, after a color image is transferred onto the transfer material P by the secondary transfer roller 5b as a secondary transfer means, the endless belt-shaped intermediate transfer body 70 from which the transfer material P is separated by curvature has residual toner removed by the cleaning device 6b.

[0106] During the image forming process, the primary transfer roller 5Bk is always in contact with the photosensitive member 1Bk. The other primary transfer rollers 5Y, 5M and 5C come into contact with the corresponding photoreceptors 1Y, 1M and 1C only during color image formation.

[0107] The secondary transfer roller 5b comes into contact with the endless belt-like intermediate transfer member 70 only when the transfer material P passes therethrough and secondary transfer is performed.

[0108] Furthermore, the housing 8 can be pulled out from the device main body A via support rails 82L and 82R.

[0109] The housing 8 comprises image forming sections 10Y, 10M, 10C and 10Bk, and an intermediate transfer unit 7 in the form of an endless belt.

[0110] The image forming units 10Y, 10M, 10C, and 10Bk are arranged in a vertical column. An endless belt-shaped intermediate transfer unit 7 is disposed on the left side of the photosensitive members 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt type intermediate transfer unit 7 comprises an endless belt type intermediate transfer member 70 which can rotate around rollers 71, 72, 73 and 74, primary transfer rollers 5Y, 5M, 5C and 5Bk, and a cleaning device 6b.

[0111] Image forming units (process cartridges) 10Y, 10M, 10C, and 10Bk have the same configuration except for the different colors of toner they contain: yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Therefore, the image forming unit (process cartridge) 10Y will be described in detail below as an example.

[0112] The image forming unit (process cartridge) 10Y has a charging means 2Y, an exposure means 3Y, a developing means 4Y, and a cleaning device 6Y around the photosensitive member 1Y, which is an image forming body, and forms a yellow (Y) toner image on the photosensitive member 1Y.

[0113] The charging means 2Y is a means for uniformly charging the surface of the photoreceptor 1Y to a negative polarity. As the charging means 2Y, for example, a corona discharge type charger is used.

[0114] The exposure means 3Y is a means for exposing the photoreceptor 1Y, to which a uniform potential has been applied by the charging means 2Y, based on an image signal (yellow), to form an electrostatic latent image corresponding to the yellow image. The exposure means 3Y may be configured with an LED in which light emitting elements are arranged in an array in the axial direction of the photosensitive member 1Y and an imaging element, or may be a laser optical system.

[0115] The developing means 4Y comprises, for example, a developing sleeve (not shown) that contains a magnet and rotates while holding developer, a photosensitive member, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve.

[0116] The developing means 4Y is composed of, for example, a developing sleeve that incorporates a magnet and rotates while holding a developer, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve and the photosensitive member.

[0117] The fixing section 24 may be, for example, a heat roller fixing type that is composed of a heating roller equipped with a heat source inside and a pressure roller that is pressed against the heating roller to form a fixing nip section.

[0118] (3.2) Main parts of the process cartridge FIG. 4 is a diagram illustrating an example of the configuration of a main part of the process cartridge (image forming unit) shown in FIG. The image forming units 10Y, 10M, 10C, and 10Bk are configured similarly except for the colors of the toner images formed on the photoreceptors 1Y, 1M, 1C, and 1Bk. Therefore, the image forming unit 10Y will be described in detail as an example, and a description of the image forming units 10M, 10C, and 10Bk will be omitted.

[0119] 4. Image forming equipment The cleaning blade of the present invention is used in an image forming apparatus having a mechanism for cleaning the surface of an image bearing member. The image forming apparatus is not particularly limited as long as it has a mechanism for cleaning the surface of the image carrier, but as an example, a tandem type image forming apparatus equipped with the image carrier shown in FIG. 3 will be described.

[0120] The image forming apparatus 100 includes a charging means for charging a photosensitive member with a charging device, an exposure means for forming an electrostatic latent image by image exposure, a developing means for developing the toner image using a developing device to make it visible, a transfer means for transferring the toner image onto a transfer medium such as paper or a transfer belt, and a charge removal means.

[0121] The toner image transferred directly onto the copy paper and the toner image transferred onto the paper via a transfer medium such as a transfer belt are fixed to the copy paper by a fixing process such as a contact heating method, thereby forming a visible image.

[0122] After the transfer, the toner remaining on the photosensitive member (transfer residual toner) is removed by a cleaning device equipped with a cleaning blade or the like.

[0123] Image forming apparatus 100 may be configured by combining components such as a photosensitive member, developing means, and cleaning device together as a process cartridge (image forming unit), and this image forming unit may be configured to be detachable from the apparatus main body. In addition, at least one of the charging means, exposure means, developing means, transfer means and cleaning means may be integrally supported together with the photosensitive member to form a process cartridge (image forming unit), which may be a single image forming unit that is detachable from the main body of the apparatus, and may be configured to be detachable using guide means such as rails on the main body of the apparatus.

[0124] (Main components of the image forming device) The image forming apparatus 100 shown in FIG. 3 has an apparatus main body A and a document image reading device SC provided on top of the apparatus main body A. The image forming apparatus 100 comprises four image forming units (process cartridges: image forming units) 10Y, 10M, 10C, and 10Bk, an endless belt-shaped intermediate transfer unit 7, a paper feed cassette 20, a paper feed unit 21, a registration roller 23, and a fixing unit 24.

[0125] (Process cartridge) The configuration and main parts of the process cartridge (image forming unit) are as described above.

[0126] (endless belt type intermediate transfer unit) The endless belt-shaped intermediate transfer body unit 7 has an endless belt-shaped intermediate transfer body 70 as a second image carrier in the form of a semiconductive endless belt that is wound around, for example, a plurality of rollers and rotatably supported, and also has a plurality of rollers 71 to 74 and a cleaning section 6b. The intermediate transfer member 70 is wound around and supported by rollers 71 to 74. The intermediate transfer member 70 rotates, for example, clockwise in accordance with the rotation of the rollers 71 to 74. The toner images (full color) transferred from the primary transfer rollers 5Y, 5M, 5C, and 5Bk to the intermediate transfer body 70 are transferred onto, for example, paper P at the secondary transfer section 5b. The secondary transfer unit 5b is provided at a position facing the roller 74, for example. The cleaning section 6b cleans the surface of the intermediate transfer body 70 after transfer to remove residual toner and the like. The cleaning unit 6b has, for example, a blade that comes into contact with the surface of the intermediate transfer body .

[0127] Image forming units 10Y, 10M, 10C, 10Bk and endless belt-shaped intermediate transfer unit The knit 7 is housed in, for example, a housing 8. The housing 8 is attached to the device main body A by a support rail 8 It is designed to be able to be pulled out via 2L and 82R.

[0128] (Paper cassette) A plurality of sheets of paper P are stacked in the paper feed cassette 20. The image forming apparatus 100 is provided with, for example, a plurality of paper feed cassettes 20.

[0129] (Paper feed section) The paper feed unit 21 sends out the topmost paper sheet P from among the paper sheets P stacked in the paper feed cassette 20, for example, to a paper transport path. The paper feed unit 21 includes, for example, a transport roller. The paper feed unit 21 may be an air suction type paper feed unit.

[0130] A plurality of intermediate rollers 22A, 22B, 22C, and 22D are provided in the paper transport path between the paper feed unit 21 and the registration rollers 23. Each of the intermediate rollers 22A, 22B, 22C, and 22D is a pair of transport rollers. For example, from the paper feed unit 21 side, the intermediate rollers are arranged in the order of intermediate roller 22A, intermediate roller 22B, intermediate roller 22C, and intermediate roller 22D.

[0131] (Registration roller) The registration rollers 23 are provided on the paper transport path between the intermediate roller 22D and the secondary transfer unit 5b. The registration rollers 23 are configured by a roller pair made up of, for example, a registration drive roller and a registration driven roller.

[0132] (fixing part) The fixing unit 24 is, for example, a fixing unit of a heat roller fixing type, and includes a heating roller and a pressure roller. The heating roller includes a heat source therein. The pressure roller is provided in pressure contact with the heating roller, and a fixing nip is formed between the heating roller and the pressure roller.

[0133] In the above embodiment, the image forming apparatus 100 is a color printer, but it may also be a monochrome printer, a copier, a multifunction machine, or the like.

[0134] Furthermore, the image forming apparatus 100 may further be provided with a lubricant removal unit (not shown) that removes the second lubricant 122 from the surfaces of the photoreceptors 1Y, 1M, 1C, and 1Bk, as necessary. For example, in the rotation direction of the photosensitive member 1Y, a lubricant supply unit 116Y may be provided downstream of the cleaning unit 6Y and upstream of the charging unit 2Y, and a lubricant removal unit may be further arranged downstream of the lubricant supply unit 116Y and upstream of the charging unit 2Y.

[0135] The lubricant removal section includes, for example, a removal member. For example, this removing member comes into contact with the surface of the photosensitive member 1Y, and the second lubricant 122 is removed by mechanical action. The removal member may be, for example, a brush roller or a foam roller.

[0136] 5. Electrophotographic Photoreceptor (5.1) Layer structure of electrophotographic photoreceptor The layer structure of the electrophotographic photosensitive member (also simply referred to as "photosensitive member"), which is the main image bearing member in the present invention, is not particularly limited, and is appropriately selected depending on the performance and application required of the electrophotographic photosensitive member. For example, the conductive support / charge generating layer / charge transport layer / surface layer may be laminated in this order, or the conductive support / charge generating / transport layer / surface layer may be laminated in this order. Alternatively, the conductive support / intermediate layer / charge generation layer / charge transport layer / surface layer may be laminated in this order, or the conductive support / intermediate layer / charge generation / transport layer / surface layer may be laminated in this order.

[0137] (5.2) Conductive support The conductive support is, for example, a cylindrical or columnar structure, and the size, material, etc. are appropriately selected depending on the application of the electrophotographic photosensitive member.

[0138] (5.3) Photosensitive layer The photosensitive layer may contain a charge generating material capable of generating charges and a charge transport material having charge transport properties, and may be composed of, for example, a charge generating layer containing a charge generating material and a charge transport layer containing a charge transport material. On the other hand, the charge generating material and the charge transporting material may be contained in one layer (charge generating / transporting layer). However, if the charge generating layer and the charge transporting layer are constructed separately, the residual potential is less likely to increase when the electrophotographic photosensitive member is used repeatedly, and further, the properties of each layer can be easily controlled depending on the purpose of the electrophotographic photosensitive member.

[0139] The charge generation layer may be any layer capable of generating charges upon irradiation with light, for example, a layer containing a charge generation substance and a binder resin, and known charge generation substances and binder resins can be used.

[0140] The charge transport layer may be any layer capable of transporting the charges generated in the charge generation layer, and may be, for example, a layer containing a charge transport material and a binder resin. Known charge transport materials and binder resins may be used.

[0141] (5.4) Surface layer The surface layer functions as a layer for protecting the above-mentioned photosensitive layer from external electrical and mechanical forces. The surface layer may contain components such as a binder resin component, a charge transport material, inorganic particles and / or organic particles, and may also contain various additives such as an antioxidant and silicone oil, as long as the objects and effects of the present invention are not impaired.

[0142] (5.5) Other layers As described above, the photoreceptor may include other layers between the conductive support and the photosensitive layer, if necessary, and may include, for example, the following intermediate layers.

[0143] The intermediate layer is a layer for transferring electrons generated in the charge generating layer to the conductive support side, and can be, for example, a layer containing conductive fine particles and a binder resin.

[0144] 6. Toner for developing electrostatic images The cleaning blade of the present invention is effective for any toner, but is particularly suitable for toners containing amorphous or crystalline resins as binder resins, and it is particularly preferred that the toner contains styrene-acrylic resins and crystalline polyester resins. [Example]

[0145] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, the terms "parts" and "%" are used, but unless otherwise specified, they represent "parts by mass" or "% by mass."

[0146] [Cleaning blade manufacturing] As described above, a urethane rubber sheet having a thickness of 2.00 mm was produced by the known centrifugal molding method. Next, the sheet was cut vertically with a blade to obtain pieces measuring 340 mm x 14.0 mm.

[0147] A cleaning blade (CL0) with a free length of 10.0 mm was fabricated by heat-bonding it to a metal plate with a bonding margin of 4 mm using a thermosetting adhesive.

[0148] <Preparation of cleaning blade (1)> The cleaning blade (CL0) was dipped in a vat containing Tospearl 120 (manufactured by Momentive Performance Materials Japan, LLC) as a first fluid lubricant, and the Tospearl 120 was applied from the ends of both ends toward the center to an area covering 8% or less of the total length in the longitudinal direction, thereby producing cleaning blade (1).

[0149] <Preparation of cleaning blade (2)> Demnum (manufactured by Daikin Industries, Ltd.) was applied as a first fluid lubricant to the cleaning blade (CL0) using a cordless electric dispenser "Tofutty MSIC06-01" (manufactured by Icomes Lab Co., Ltd.) in an area of ​​8% or less of the total length in the longitudinal direction from the ends of both ends toward the center, to produce cleaning blade (2).

[0150] <Preparation of cleaning blades (3) to (10), (13) and (14)> The cleaning blade was prepared in the same manner as cleaning blade (2), except that the type of the first lubricant having flowability and the percentage of the total length of the longitudinal direction of the cleaning blade to which the first lubricant was applied from the ends of both ends of the cleaning blade toward the center were as shown in Table I.

[0151] <Preparation of cleaning blade (11)> A cleaning blade (CL0) was dipped in polyamide resin with reference to Example 1 of JP 2002-162885 A, and a resin film was formed in an area extending from the ends of both longitudinal ends toward the center, covering 5% or less of the total length in the longitudinal direction, to prepare a cleaning blade (11).

[0152] <Preparation of cleaning blade (12)> The cleaning blade (CL0) obtained by the above method was impregnated with an appropriate amount of an isocyanate compound with reference to Example 1 of JP 2010-170157 A, and the isocyanate compound was allowed to stand for 20 minutes after contacting the cleaning blade, thereby forming a cured treated portion in an area extending from the ends of both longitudinal ends toward the center in a length of 5% or less of the total length in the longitudinal direction, thereby producing a cleaning blade (12).

[0153] [Cleaning blade evaluation] The various cleaning blades prepared above were evaluated for resistance or prevention of curling, slip-through, fogging, and density unevenness as follows. A. Evaluation of peeling (Preparation of evaluation equipment) A full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) was modified to a linear speed of 500 mm / sec, the developing unit was removed, and a torque measuring instrument and an oscilloscope were connected to the photosensitive unit and intermediate transfer belt unit, respectively. Furthermore, each cleaning blade prepared by the above process was disposed at the cyan (C) position of the photosensitive unit or the intermediate transfer belt unit to prepare an image forming apparatus for evaluation. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0154] (Evaluation method) The evaluation of curling was carried out by driving the photosensitive unit and intermediate transfer belt for 90 minutes in an environment of 30° C. and 85% RH, and measuring the torque value of each while observing whether curling of the cleaning blade occurred. The evaluation criteria are as follows: Evaluation results of "A" to "C" were judged to be acceptable (practical).

[0155] (Evaluation criteria) A: The torque value was 0.60 [N·m] or less (passed). B: Torque value was greater than 0.60 [N·m] and less than 0.80 [N·m] (pass). C: The torque value was greater than 0.80 N m, but the cleaning blade did not retract slightly (passed). D: The torque value was greater than 0.80 [N·m], and slight retraction occurred, but the cleaning blade did not turn over (failed). E: The cleaning blade was turned over (failed).

[0156] B. Evaluation of slip-through (Preparation of evaluation equipment) An image forming apparatus for evaluation was prepared by modifying a full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) to have a linear speed of 500 mm / sec and modifying it so that the lubricant (second lubricant) pressing force was halved (for example, by changing the strength of the spring that presses the lubricant rod against the lubricant application brush). Each cleaning blade prepared by the above process was placed at the cyan (C) position of the photosensitive unit or the intermediate transfer belt unit. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0157] (Evaluation method) The toner slip-through evaluation was performed by printing 20,000 sheets of halftone image (a) with a coverage rate of 80% as shown in Figure 5 on A3-size neutral paper in an environment of 10°C and 20% RH, with the black part positioned at the front in the paper transport direction and the white part positioned at the rear, and visually observing the white part of the 20,000th sheet of paper. The evaluation criteria are as follows: Evaluation results of "A" or "B" were judged to be pass (practical).

[0158] (Evaluation criteria) A: No stains were observed on the white background. (Pass) B: Slight streak stains occurred on the white background, but this does not pose a problem in practical use (pass). C: Obvious streaky stains were observed on the white background, making it unsuitable for practical use (failed).

[0159] C. Evaluation of fogging (Preparation of evaluation equipment) An image forming apparatus for evaluation was prepared by modifying a full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) to have a linear speed of 200 mm / sec. Each cleaning blade prepared by the above process was placed at the black (K) position of the photosensitive unit. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0160] (Evaluation method) First, in an environment of 23° C. and 50% RH, a test image consisting of a vertical band-shaped solid image with a coverage of 10% as shown in FIG. 6 was continuously printed on 1000 sheets of A4 paper in landscape orientation. Next, the transfer material "POD Gloss Coat (A3 size, 100 g / m 2 A plain image (solid white image) was formed on a (Oji Paper) under conditions of a grid voltage of -800V and a developing bias of -700V, to prepare a print for evaluating fog. The fog density of the resulting print was measured using a Konica Minolta fluorescent spectrodensitometer "FD-7."

[0161] (a) The absolute image density was measured at 20 arbitrary points on a transfer material (blank paper) on which no image was formed, and the average value was taken as the "blank paper density before image formation."

[0162] (b) The absolute image density was measured at 20 random locations on the print for fog evaluation, and the average value was taken as the "blank paper density after forming a plain image."

[0163] (c) The white paper densities obtained in (a) and (b) above were calculated as the fog density based on the following formula: Formula: Fog density = (blank paper density after plain image formation) - (blank paper density before image formation)

[0164] The evaluation criteria are as follows: Evaluation results of "A" to "D" were judged to be acceptable (practical).

[0165] (Evaluation criteria) A: The fog density was 0.003 or less (passed). B: The fog density was more than 0.003 and 0.005 or less (passed). C: The fog density was greater than 0.005 and equal to or less than 0.007 (pass). D: The fog density was greater than 0.007 and equal to or less than 0.01 (pass). E: The fog density is more than 0.01, which is problematic for practical use (failure).

[0166] D. Evaluation of density unevenness (Preparing the image forming device) An image forming apparatus for evaluation was prepared by modifying a full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) to have a linear speed of 200 mm / sec. Each cleaning blade prepared by the above process was placed on the intermediate transfer belt unit. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0167] (Evaluation method) First, in an environment of 23° C. and 50% RH, a test image consisting of a vertical band-shaped solid image with a coverage of 10% as shown in FIG. 6 was continuously printed on 1000 sheets of A4 paper in landscape orientation. Next, the transfer material "POD Gloss Coat (A3 size, 100 g / m 2 A full-surface (K) half image was formed on a black ink sheet (manufactured by Oji Paper Co., Ltd.) to prepare a print for evaluating density unevenness.

[0168] The evaluation criteria for density unevenness are as follows. Evaluation results of "A" and "B" were judged to be practical.

[0169] (Evaluation criteria) A: No uneven density is observed (passed) B: Slight unevenness in density is observed, but at a level that does not pose a problem for practical use (Pass) C: Density unevenness is clearly observed, and is at a level that is problematic for practical use (failure).

[0170] E. Summary From the results shown in Table I below, it can be seen that the cleaning blades of the examples are superior to the cleaning blades of the comparative examples. The cleaning blade of the present invention was found to be superior overall in terms of peeling, slip-through, fogging, and density unevenness compared to the conventional cleaning blade, demonstrating that the cleaning blade of the present invention has better peeling resistance and cleaning properties than the conventional cleaning blade. In Table I, Examples 1 to 4 and 9 should be read as Reference Examples 1 to 4 and 9, respectively.

[0171] [Table 1] [Explanation of symbols]

[0172] 1Y, 1M, 1C, 1Bk photoconductor 2Y, 2M, 2C, 2Bk Charged part 3Y, 3M, 3C, 3Bk exposure area 4Y, 4M, 4C, 4Bk developing section 5Y, 5M, 5C, 5Bk Primary transfer roller (primary transfer section) 5b Secondary transfer section 6Y, 6M, 6C, 6Bk, 6b Cleaning device 7 Intermediate transfer unit 8. Housing 10Y, 10M, 10C, 10Bk Image forming unit (process cartridge) 20 Paper cassette 21 Paper feed section 22A, 22B, 22C, 22D Intermediate rollers 23 Resist Roller 24 Fixing section 25 Paper ejection roller 26 Paper output tray 70 Intermediate transfer body 71~74 Roller 82R, 82L support rails 100 Image forming device 116Y Lubricant supply section 121 Brush Roller 122 Second Lubricant 122a surface 123 Pressure spring A Main Unit P paper SC Document Image Reader CL Cleaning Blade E1 Edge 1 E2 Edge 2 SA Face A SB side B SC side C Y image carrier EP end area CP central region

Claims

1. A cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, the cleaning blade has regions at both ends in a longitudinal direction where a first lubricant having fluidity is present, the first lubricant present in the regions at both ends is grease; the first lubricant present in the regions at both ends contains a silicone resin component; The regions of the both ends where the first lubricant is present are regions of 4 to 8% of the entire length in the longitudinal direction from the ends of the both ends toward the center. A cleaning blade characterized by:

2. a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present; 2. The cleaning blade according to claim 1.

3. A cleaning device provided in an image forming apparatus and having a mechanism for cleaning the surface of an image bearing member, The cleaning blade according to claim 1 or 2 is provided. A cleaning device characterized by:

4. A process cartridge detachable from an image forming apparatus main body, The cleaning device according to claim 3 is provided. A process cartridge characterized by:

Images