Cleaning blade, process cartridge, and image forming apparatus

Abstract

To provide a cleaning blade that can suppress torque increase even immediately after starting use of an image forming apparatus, and that can achieve good cleaning performance even when continuously printing high-density images. [Solution] A cleaning blade that contacts the surface of a member to be cleaned to remove residue from the surface of the member to be cleaned, wherein the cleaning blade comprises a cleaning blade base having an elastic member and a cleaning blade support member supporting the cleaning blade base, the elastic member having a coating layer provided at the tip portion that contacts the member to be cleaned, and the developed interface area ratio Sdr in a 100 μm square area inward from the tip ridge portion of the coating layer on the lower surface of the cleaning blade base is 1.2% or more and 1.8% or less.

Description

Technical Field

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

Background Art

[0002] Conventionally, in an electrophotographic image forming apparatus, after transferring a toner image onto a recording medium or an intermediate transfer member by an image forming process, residual toner adhering to the surface of an image carrier (which may also be referred to as a member to be cleaned) is removed by 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 an elastic member made of polyurethane rubber or the like and a support member. Then, the base end of the elastic member is supported by the support member, and the contact portion (tip ridge line portion) of the elastic member is pressed against the surface of the image carrier to block and scrape off the toner remaining on the surface of the image carrier for removal. In the cleaning means using the cleaning blade, since the cleaning blade and the image carrier are in contact with each other, friction occurs between the cleaning blade and the image carrier, and torque, which is the force required to rotate the image carrier, increases, and there may be a problem that the image carrier stops. Further, due to the rubbing between the cleaning blade and the image carrier, the contact portion wears, the contact portion turns up, and toner slips through the turned-up portion, resulting in a problem of poor cleaning in some cases.

[0004] For example, in recent years, in the case of the cleaning blade, a cleaning blade coated with a lubricant containing a fluorine-based compound has been used for the purpose of reducing the frictional force with the image carrier, and a cleaning blade in which the fluorine-based compound contained in the lubricant is vinylidene fluoride has been proposed (see Patent Documents 1 to 5). Furthermore, in order to provide the elastic member of the cleaning blade with appropriate flexibility and hardness, and to prevent peeling and gouging wear of the tip ridge of the cleaning blade, the Martens hardness of the surface of the elastic member at a distance of 20 [μm] inward from the tip ridge is set to 1.0 [N / mm²]. 2 ]~15.0[N / mm 2 A cleaning blade has been proposed (see Patent Document 6). Furthermore, to improve the sliding properties of the cleaning blade, a cleaning blade coated with a dispersion of PMMA (polymethacrylic acid) particles dispersed in a fluorine-based solvent has been proposed (see Patent Document 7). [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a cleaning blade that can suppress torque increases even immediately after the start of use of an image forming apparatus, and that can achieve good cleaning performance even when continuously printing high-density images such as full solid images. [Means for solving the problem]

[0006] The cleaning blade of the present invention, as a means for solving the above problem, is a cleaning blade that comes into contact with the surface of a member to be cleaned and removes residue from the surface of the member to be cleaned, The cleaning blade comprises a cleaning blade base having an elastic member and a cleaning blade support member that supports the cleaning blade base. The elastic member has a covering layer provided on the tip portion that contacts the member to be cleaned. The coating layer on the lower surface of the cleaning blade base is characterized in that the unfolded interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.2% or more and 1.8% or less. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a cleaning blade that can suppress the increase in torque even immediately after the start of use of the image forming apparatus, and that can obtain good cleaning performance even when continuously printing high-density images such as full solid images. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a cleaning blade in contact with the surface of the image carrier. [Figure 2] Figure 2 is a perspective view showing an example of a cleaning blade for an image carrier according to the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view showing another example of the cleaning blade for image carriers of the present invention. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of the image forming apparatus of the present invention. [Figure 5] Figure 5 is a schematic cross-sectional view showing an example of a process cartridge in the image forming apparatus shown in Figure 4. [Figure 6] Figure 6 is a schematic diagram showing the method of forming the coating layer as performed in the example. [Modes for carrying out the invention]

[0009] In the following description, a cleaning blade according to one embodiment of the present invention will be explained with reference to Figures 1 to 3. However, the applications of the cleaning blade of the present invention are not limited in any way to these embodiments. In each drawing, the same reference numerals are used for the same components, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to this embodiment, and can be set to a number, position, shape, etc. that is preferable for carrying out the present invention.

[0010] Figure 1 is a schematic cross-sectional view showing a cleaning blade according to one embodiment of the present invention. The cleaning blade 62 has a cleaning blade support member 621 and a cleaning blade base 622, the cleaning blade base 622 having an elastic edge layer 622a and a base layer 622b, and a contact portion 62c on the edge layer 622a.

[0011] Figure 2 is a schematic perspective view and an enlarged view showing a cleaning blade according to one embodiment of the present invention. As shown in Figure 2, the contact portion 62c has a coating layer 623 on at least a portion of the contact portion 62c, including the contact edge.

[0012] Figure 3 is a schematic cross-sectional view showing a cleaning blade according to one embodiment of the present invention. The cleaning blade 62 comprises a flat cleaning blade support member 621 made of a rigid material such as metal or hard plastic, and a flat cleaning blade base 622 having one end connected to the cleaning blade support member 621 and the other end having a free end of a predetermined length. The cleaning blade base 622 is fixed to one end of the cleaning blade support member 621 with an adhesive or the like, and the other end of the cleaning blade support member 621 is cantilevered to the case of the cleaning device. The cleaning blade base 622 has a cleaning blade tip surface 62a, a cleaning blade lower surface 62b, a cleaning blade contact portion 62c which is one end of the free end side of the cleaning blade base 622, and a cleaning blade side surface 62d, and has a coating layer 623 on at least a part of the cleaning blade contact portion 62c including the contact edge. The cleaning blade 62 is arranged such that the cleaning blade contact portion 62c contacts the surface of the photoreceptor 3 along the longitudinal direction. As shown in Figures 1 to 3, the lower surface 62b of the cleaning blade is the side of the cleaning blade base 622 that does not have the cleaning blade support member 621.

[0013] Hereinafter, a cleaning blade according to an embodiment of the present invention will be described when the image carrier is used as the member to be cleaned. In the following, the "blade base body in the cleaning blade" may be referred to as the "blade base body".

[0014] [Cleaning Blade] A cleaning blade according to an embodiment of the present invention is a cleaning blade that abuts on the surface of a member to be cleaned and removes residues on the surface of the member to be cleaned, The cleaning blade includes a cleaning blade base body having an elastic member, and a cleaning blade support member that supports the cleaning blade base body. The elastic member has a coating layer provided at a tip portion that abuts on the member to be cleaned. In the coating layer on the lower surface of the cleaning blade base body, the developed interface area ratio Sdr in a 100 μm square from the tip ridge line portion inward is 1.2% or more and 1.8% or less, and further, other members are provided as required. The cleaning blade of the present invention is a cleaning blade that removes residues adhering to the image carrier by abutting on the surface of the image carrier.

[0015] The residues are not particularly limited as long as they adhere to the surface of the image carrier and are to be removed by the cleaning blade. Examples include toner, lubricant, inorganic fine particles, organic fine particles, paper powder, dust, dirt, and mixtures thereof.

[0016] In the conventional cleaning means using a cleaning blade, due to the friction generated by the contact between the cleaning blade and the image carrier, the torque, which is the force required to rotate the image carrier, increases, and there is a problem that the rotation of the image carrier stops. Further, due to the friction, the contact portion between the cleaning blade and the image carrier wears, and curling of the cleaning blade and toner leakage occur, resulting in a problem of poor cleaning.

[0017] To improve the sliding properties of the cleaning blade and prevent the blade from curling or increasing torque, a process (touch-up) is widely used in which metal soaps such as zinc stearate or PMMA (polymethacrylic acid) particles are applied as a lubricant to the tip of the cleaning blade. Normally, as the image forming apparatus operates, toner gradually accumulates between the cleaning blade and the image carrier, and the toner functions as a lubricant. Therefore, the lubricant only needs to exhibit lubricating properties for a short period from the start of the image forming apparatus until the behavior of the cleaning blade stabilizes. However, the fine particles contained in conventional lubricants have weak adhesion to the substrate, and there was a problem that they detached from the cleaning blade before the behavior of the cleaning blade stabilized.

[0018] Furthermore, a technique is known in which a lubricant consisting of particles and a binder resin that fixes the particles is applied to the contact portion of the cleaning blade with the image carrier in order to suppress the detachment of particles from the cleaning blade. Although the binder resin makes it difficult for particles to detach from the cleaning blade, thus being effective in preventing an increase in torque, the lubricant tends to remain on the cleaning blade, making it difficult for the tip of the cleaning blade to be exposed, which reduces the pressure on the contact portion with the image carrier and worsens the cleaning performance. This becomes more pronounced when a large amount of toner enters the nip portion between the cleaning blade and the image carrier, such as in continuous printing of a full solid image.

[0019] The inventors, after diligent research, have found the following: Specifically, focusing on the surface area of ​​the coating layer made of lubricant, increasing the surface area of ​​the coating layer (for example, by increasing the density of the film on the surface of the coating layer) increases the true contact area with the image carrier and the resulting frictional force, which in turn makes the coating layer easier to wear off. This makes the coating layer at the tip of the cleaning blade easier to wear off while maintaining the prevention of torque increase, causing the blade tip to be exposed earlier and increasing the pressure applied to the contact area with the image carrier. This makes it possible to maintain cleaning performance even when a large amount of toner enters the nip between the cleaning blade and the image carrier, such as in continuous printing of a full solid image, and thus achieves both prevention of torque increase and cleaning performance. The surface area of ​​the coating layer is expressed by the unfolded interface area ratio Sdr, which represents the rate of increase in its surface area over a given image area. A larger value for the unfolded interface area ratio Sdr indicates a denser and more undulating surface shape.

[0020] Therefore, a cleaning blade according to one embodiment of the present invention is a cleaning blade that contacts the surface of a member to be cleaned to remove residue from the surface of the member to be cleaned, and the cleaning blade comprises a cleaning blade base having an elastic member and a cleaning blade support member that supports the cleaning blade base, the elastic member having a coating layer provided on the tip portion that contacts the member to be cleaned, and the unfolded interface area ratio Sdr in a 100 μm square area inward from the tip ridge portion of the coating layer on the lower surface of the cleaning blade base is 1.2% or more and 1.8% or less, thereby suppressing an increase in torque even immediately after starting to use the image forming apparatus, and providing a cleaning blade that exhibits good cleaning performance even when a large amount of toner enters the nip portion with the image carrier, such as in continuous printing of a full solid image.

[0021] <Coating layer> The coating layer contains particles and a binder resin as an immiscible binding component to the particles, and optionally contains other components. The coating layer refers to the layer provided on one end of the blade base used as the tip of the cleaning blade on the peripheral surface of the blade base, which will be described later. The coating layer may be formed on at least a part of the blade base including the contact edge where the cleaning blade and the image carrier come into contact, or it may be formed on the entire contact edge, or it may be formed on the entire surface of the blade base. Among these, it is preferable that the coating layer be formed on the entire contact edge. The surface area of ​​the blade base where the coating layer is not provided is sometimes referred to as the uncoated area.

[0022] The average thickness of the coating layer is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably between 0.5 [μm] and 12 [μm]. If the average thickness of the coating layer is 0.5 [μm] or more, a sufficient sliding effect can be obtained. If the average thickness of the coating layer is 12 [μm] or less, the effect of maintaining cleanability can be obtained by making the coating layer easier to wear. The thickness of the coating layer on the lower surface of the cleaning blade base is preferably 0.5 μm to 12 μm, more preferably 3.5 μm to 12 μm, and even more preferably 3.5 μm to 4.5 μm, at a distance of 100 μm inward from the tip ridge of the cleaning blade. The average thickness of the coating layer can be calculated by using the average of the thickness [μm] measured at three or more locations on the coating layer. Possible measurement locations for the average thickness of the coating layer include a point 100 [μm] inward from the edge, and the central part of the coating layer.

[0023] The average thickness of the coating layer can be measured by scraping a portion of the coating layer with a spatula or cotton swab, and then measuring its shape using a 3D measuring instrument such as a contact-type surface roughness meter (Surftest SJ-500: manufactured by Mitutoyo) or a laser microscope (LEXT OLS4100: manufactured by Olympus).

[0024] The coating layer preferably contains particles and a resin as a binding component (hereinafter sometimes referred to as "binding resin"), and has a sea-island structure in which the particles are domains (island phases) and the binding resin is a matrix (sea phase). It is preferable to select the type of particles and the amount added according to the type of binding resin so that the particles form domains.

[0025] There are no particular restrictions on the shape of the particles; they can be appropriately selected according to the purpose, and they may be regular or irregular in shape. Among these, irregular shapes are preferable because they easily increase the surface area of ​​the coating layer. On the other hand, if the particle shape is regular, it is preferable that it be spherical. This shape is preferable because it prevents problems such as particles detaching from the coating layer damaging the image carrier or the blade base in the cleaning blade.

[0026] There are no particular restrictions on the volume-average particle diameter (50% volume diameter, median diameter) of the particles, and it can be appropriately selected according to the purpose, but it 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. If the volume-average particle diameter of the particles is 1 [μm] or less, it becomes easy for the particles to settle in the solvent, which prevents the problem of difficulty in stable dispersion. Furthermore, if the volume-average particle diameter of the particles is 0.5 [μm] or less, they can be dispersed more stably in non-aqueous solvents.

[0027] The coating layer may contain multiple particles of different particle sizes.

[0028] There are no particular restrictions on the method for measuring the volume-average particle diameter (50% volume diameter, median diameter), and it can be appropriately selected depending on the purpose. For example, it can be measured by laser diffraction / scattering, dynamic light scattering, or image imaging. Specific examples of the volume-average particle diameter measurement method include measuring particles collected from the coating layer of the cleaning blade by passing them through a Microtrac (manufactured by Nikkiso Co., Ltd.) using the laser diffraction / scattering method, and measuring fine particles on the cleaning blade by directly observing them using a scanning electron microscope (SEM). Note that the volume-average particle diameter of the particles is almost the same when added to the dispersion applied to the cleaning blade and when present in the coating layer.

[0029] There are no particular restrictions on the particle content in the coating layer, and it can be selected according to the purpose. However, in order to obtain a sliding effect and because the content is relatively higher than that of the binder resin, the coating layer becomes brittle and the particles tend to detach easily, it is preferable that the content be 80% to 99% by mass, and more preferably 90% to 98% by mass, relative to the total mass of the coating layer.

[0030] There are no particular restrictions on the material of the particles, and they can be selected according to the purpose. Examples include polytetrafluoroethylene (PTFE), ethylene fluoride-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 in that it further improves the sliding properties of the cleaning blade.

[0031] Polytetrafluoroethylene (PTFE) may be synthesized as appropriate, or commercially available products may be used. Examples of commercially available polytetrafluoroethylene (PTFE) include Dynion TF Micropowder TF-9201Z, Dynion 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 Corporation), and Algoflon L203F (manufactured by Solway).

[0032] The resin acting as a binding component (binding resin) functions as a binding component between the coating layer and the elastic member. The inclusion of a binding resin in the coating layer improves the adhesion of the particles to the cleaning blade substrate, preventing the coating layer from detaching. This prevents the cleaning blade from peeling or the torque from increasing. Preferably, the binding resin is the matrix (sea phase) in the sea-island structure of the coating layer. It is preferable to select the type and amount of resin added to the particles so that the binding resin forms the matrix.

[0033] The binder resin is not particularly limited as long as it can uniformly and stably disperse the particles, and can be appropriately selected depending on the purpose. Examples include vinylidene fluoride (VdF), hexafluoropropylene (HFP), tetrafluoroethylene (TFE), polyvinyl alcohol resin, and polyvinyl acetal resin. Among these, copolymers combining them are preferred from the viewpoint of lubricity and adhesion to the blade substrate, and a ternary copolymer of VdF-HFP-TFE is more preferred.

[0034] In the ternary copolymer, the VdF / HFP / TFE composition is preferably 30 mol% to 80 mol%, 10 mol% to 35 mol%, and 5 mol% to 35 mol% respectively, in terms of monomer units, from the standpoint of imparting blade flexibility and solubility in the solvent.

[0035] The combination of particles and binder resins is not limited to the examples shown above, and can be appropriately selected according to the purpose. Examples include inorganic compounds, fluororesin particles, acrylic resin particles as particles, and acrylic resins, styrene resins, and vinyl resins as binder resins. Examples of inorganic compounds include silica, alumina, and zirconia. These may be used individually or in combination of two or more. If the particles are polytetrafluoroethylene particles, the binder resin is preferably a fluororesin; if the particles are acrylic particles, the binder resin is preferably a polyvinyl alcohol resin or a polyvinyl acetal resin.

[0036] As for particles other than fluororesin, acrylic resin is preferred because it has a certain degree of hardness and therefore can be expected to have a sliding effect. On the other hand, there are no particular restrictions on the shape, and can be appropriately selected according to the purpose, but a spherical shape is preferred. This shape is preferable because it prevents problems such as damage to the image carrier or the blade base of the cleaning blade by particles other than fluororesin that have detached from the coating layer.

[0037] There are no particular restrictions on the volume-average particle diameter (50% volume diameter, median diameter) of particles other than fluororesins, and they can be appropriately selected according to the purpose. However, it is preferably 0.1 [μm] or more and 1 [μm] or less, more preferably 0.5 [μm] or less, and even more preferably 0.3 [μm] or less. If the volume-average particle diameter of the particles is 1 [μm] or less, the particles tend to settle in the solvent, which prevents the problem of difficulty in stable dispersion. Furthermore, if the volume-average particle diameter of the particles is 0.5 [μm] or less, they can be dispersed more stably in non-aqueous solvents.

[0038] There are no particular restrictions on the method for manufacturing the coating layer, and it can be appropriately selected depending on the purpose. For example, it can be obtained by adding particles to a mixture of a solvent and a binder resin, mixing them, and applying the resulting particle dispersion to the blade substrate of the cleaning blade.

[0039] There are no particular restrictions on the solvent, and it can be appropriately selected depending on the purpose. For example, in the case of fluororesin particles and binder resins, fluorine-containing organic solvents can be used. Examples of the fluorine-containing organic solvents include hydrofluoroethers (HFE), perfluorocarbons (PFCs), and perfluoroethers (PFE). These may be used individually or in combination of two or more.

[0040] The average particle diameter of the particles in the binder resin, as determined by dynamic light scattering (average particle diameter of the cumulant method analysis in the scattering intensity distribution), is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less, from the standpoint of obtaining a uniform dispersion. Normally, even when using fine particles with a volume-average particle diameter of 1 μm or less, the particles aggregate to form secondary particles, which are fine particles with a volume-average particle diameter of 1 μm or more. By dispersing the fine particles that have aggregated to form secondary particles so that they have a particle diameter of 1 μm or less, a stable dispersion can be obtained even when the fluororesin dispersion is stored for a long period of time at low viscosity. There are no particular restrictions on the dispersion method, and it can be appropriately selected according to the purpose. For example, methods using dispersants such as ultrasonic dispersers, three-roll dispersers, ball mills, bead mills, and jet mills can be used.

[0041] There are no particular restrictions on the method for forming the coating layer, and it can be appropriately selected depending on the purpose. For example, dipping is a method in which the entire blade base of the cleaning blade, or a part of the blade base, is submerged in a particle dispersion for treatment. In addition to dipping, other coating methods such as spray coating and dispensing may also be used.

[0042] <Blade base> The blade base may be referred to as the "blade base" or simply the "base." The shape of the blade base can be any structure that can remove residue from the image carrier, and can be appropriately selected depending on the purpose, but it is preferable that the contact edge at the contact portion between the blade base and the image carrier is straight. Examples of blade base shapes include a plate shape. As shown in Figure 2, the blade base has a tip surface 62a, a lower surface 62b, a contact portion 62c, a side surface 62d, and a coating layer 623 covering at least a portion of the contact portion 62c, including the contact edge.

[0043] <<Developed interface area ratio Sdr>> In one embodiment of the present invention, the cleaning blade has a coating layer 623 on the lower surface 62b of the cleaning blade base in which the unfolded interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.2% or more and 1.8% or less, preferably 1.4% or more and 1.7% or less. When the unfolded interface area ratio Sdr is 1.2% or more, the effect of making the coating layer sufficiently easy to abrade can be obtained, and both a sliding effect and cleaning performance due to the easy abrasion of the film can be achieved. When the unfolded interface area ratio Sdr is 1.8% or less, excessive abrasion of the coating layer can be suppressed, so a sufficient sliding effect can be obtained. The coating layer contains particles and a binder resin, and the fact that the coating layer is easily abraded is due to the fact that the surface made up of particles and binder resin is dense and has a rough surface, which in turn increases the true contact area with the image carrier and increases the frictional force.

[0044] -Measurement of the expanded interface area ratio (Sdr)- The Sdr (Surface Area Ratio) of the developed interface can be obtained from observation images using a confocal laser microscope. In this invention, the Sdr of the developed interface is measured on a cleaning blade. Specifically, a confocal laser microscope (OLS-4100, manufactured by Olympus Corporation) is used to acquire a brightness image of the surface of the coating layer using a 100x objective lens. The Sdr of the developed interface is obtained and used in a 100 [μm] square area from the tip using the attached analysis application.

[0045] <<Martens hardness>> The Martens hardness of the blade base in the cleaning blade according to one embodiment of the present invention is not particularly limited and can be appropriately selected depending on the purpose, but is less than 0.5 [N / mm²]. 2 ] or more 2[N / mm 2 Preferably, the following conditions apply. By having the Martens hardness of the blade base in the cleaning blade be within the desired range, it is possible to eliminate problems such as poor cleaning caused by difficulty in obtaining blade linear pressure and an increase in the contact area with the image carrier, as well as chipping caused by the blade base becoming too hard.

[0046] -Measurement of Martens hardness- There are no particular restrictions on the location for measuring Martens hardness, but for ease of measurement, it can be located 20 μm inward from the edge of the base layer. The Martens hardness is measured at 4 to 6 points at each measurement location, and the median value of the obtained values ​​is shown. The measurement conditions are based on ISO 14577, using a nanoindenter (ENT-3100, manufactured by Elionix Corporation) to continuously indent a Berkovich indenter for 10 seconds until a maximum load of 1,000 μN is reached, held for 5 seconds, and then unloaded for 10 seconds at the same loading rate. The Martens hardness obtained under these conditions is adopted.

[0047] <Rebound modulus> The rebound modulus of the blade base in the cleaning blade according to one embodiment of the present invention is not particularly limited and can be appropriately selected depending on the purpose, but 10% to 80% at 23°C is preferred. By having the rebound modulus within the desired range, it is possible to eliminate problems such as poor cleaning caused by the loss of flexibility of the entire blade base and its inability to follow the vibration and roughness of the image carrier, or blade noise (abnormal sound) caused by excessive rebound.

[0048] -Measurement of rebound modulus- The resilience coefficient of the blade base can be measured, for example, in accordance with the JIS K6255 standard at 23°C using a No. 221 resilience tester manufactured by Toyo Seiki Seisakusho Co., Ltd.

[0049] There are no particular restrictions on the structure of the blade base, and it can be appropriately selected according to the purpose. Examples include a single-layer structure, a laminated structure, and a laminated structure combining multiple members. Among these, a single-layer structure and a laminated structure made by stacking multiple members are preferred from the viewpoint of ease of processing into a cleaning blade. When the blade base has a laminated structure, the layer that comes into contact with the image carrier may be called the edge layer, and the layers that are not the edge layer may be called the base layer. When the blade base is a single layer, the blade base has only an edge layer. It is more preferable that the Martens hardness of the multiple members in the laminated structure differs from each other.

[0050] There are no particular restrictions on the material of the blade base, and it can be appropriately selected depending on the purpose. However, from the viewpoint of preventing wear of the blade base and from the viewpoint of sufficiently removing the residue on the intermediate transfer body, it is preferable that it has appropriate elasticity and hardness. Examples of the material of the blade include elastic materials. As long as the elastic material has high elasticity, there are no particular restrictions, and it can be appropriately selected depending on the purpose. Examples include polyurethane rubber, silicone rubber, fluororubber, nitrile rubber (NBR), and ethylene propylene diene rubber (EPDM). Among these, polyurethane rubber is preferred from the viewpoint of durability and non-contamination. There are no particular restrictions on the size of the blade base, and it can be appropriately selected according to the size of the image carrier.

[0051] There are no particular limitations on the method for manufacturing the blade substrate, and it can be appropriately selected depending on the purpose. For example, a polyurethane prepolymer can be prepared using a polyol compound and a polyisocyanate compound, a curing agent and, if necessary, a curing catalyst can be added to the polyurethane prepolymer, then centrifugal molding can be performed using a predetermined mold, and the resulting material can be matured (cured) by leaving it at room temperature before being cut into a flat plate of predetermined dimensions. The polyol compound is not particularly limited and can be appropriately selected depending on the purpose. Examples include high molecular weight polyols and low molecular weight polyols.

[0052] Examples of the high molecular weight polyols include polyester polyols which are condensates of alkylene glycol and aliphatic dibasic acid; polyester polyols 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, which are polyester polyols of alkylene glycol and adipic acid; polycaprolactone polyols such as polycaprolactone ester polyol obtained by ring-opening polymerization of caprolactone; and polyether polyols such as poly(oxytetramethylene) glycol and poly(oxypropylene) glycol. These may be used individually or in combination of two or more.

[0053] Examples of the low molecular weight polyols 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 individually or in combination of two or more.

[0054] The polyisocyanate compound is not particularly limited and can be appropriately selected depending on the purpose. Examples include methylenediphenyl diisocyanate (MDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), naphthylene 1,5-diisocyanate (NDI), tetramethyl xylylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate (H6XDI), dicyclohexylmethane diisocyanate (H12MDI), hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), and trimethylhexamethylene diisocyanate (TMDI). These may be used individually or in combination of two or more.

[0055] The curing agent is not particularly limited and can be appropriately selected depending on the purpose, and examples include amines and alcohols. These may be used individually or in combination of two or more. The curing agent is used, for example, to adjust the hardness of the blade substrate.

[0056] The curing catalyst is not particularly limited and can be appropriately selected depending on the purpose. Examples 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% to 0.5% by mass, and more preferably 0.05% to 0.3% by mass, relative to the total mass of the prepolymer and curing agent.

[0057] [Image forming apparatus and image forming method] The image forming apparatus of the present invention comprises at least an image carrier, a charging means for charging the surface of the image carrier, an exposure means for exposing the charged image carrier to form an electrostatic latent image, a developing means for developing the electrostatic latent image using toner to form a visible image, a transfer means for transferring the visible image to a recording medium via an intermediate transfer body, a fixing means for fixing the transferred image on the recording medium, and a cleaning means for removing toner remaining on the intermediate transfer body, and further comprises other means as appropriate as necessary. The charging means and the exposure means may be collectively referred to as the electrostatic latent image forming means. The cleaning means each has a cleaning blade according to the present invention. The image forming method used in the present invention includes at least a charging step, an exposure step, a developing step, a transfer step, a fixing step, and a cleaning step, and further includes other steps as appropriate as necessary. The charging step and the exposure step together may be referred to as the electrostatic latent image formation step. The image forming method used in the present invention can be suitably carried out by the image forming apparatus of the present invention, the charging step can be carried out by the charging means, the exposure step can be carried out by the exposure means, the development step can be carried out by the development means, the transfer step can be carried out by the transfer means, the fixing step can be carried out by the fixing means, and the cleaning step can be carried out by the cleaning means, the cleaning means having the cleaning blade of the present invention. The other steps can be carried out by the other means.

[0058] <Image carrier> There are no particular restrictions on the structure, size, etc., of the image carrier, and it can be appropriately selected from known types. There are no particular restrictions on the shape of the image carrier, and it can be appropriately selected according to the purpose, for example, drum-shaped, belt-shaped, etc. There are no particular restrictions on the material of the image carrier, and it can be appropriately selected according to the purpose, for example, inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Examples of the organic photoreceptor include a laminated photoreceptor having a laminated structure in which a layer in which a charge-generating material such as metal-free phthalocyanine or titanylphthalocyanine is dispersed in a binder resin (charge-generating layer) and a layer in which a charge-transporting material is dispersed in a binder resin (charge-transporting layer) are stacked on a support such as an aluminum drum, and a single-layer photoreceptor having a single-layer photoreceptor in which both a charge-generating material and a charge-transporting material are dispersed in a binder resin on a support. In single-layer photoreceptors, hole transporters and electron transporters can be added to the photosensitive layer as charge transport materials. Furthermore, an undercoat layer may be provided between the support and the multilayer charge generation layer or the single-layer photosensitive layer.

[0059] <Charging process and charging means> The charging step is a step of charging the surface of the image carrier, and is performed by the charging means. The charging means is not particularly limited as long as it can charge the surface of the image carrier, and can be appropriately selected according to the purpose. Examples include contact chargers that are known themselves and equipped with conductive or semiconducting rollers, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as Corotron and Scorotron. The shape of the charging means can be any form, such as a roller, magnetic brush, or fur brush, and can be selected according to the specifications and form of the electrophotographic image forming apparatus. When a magnetic brush is used, the magnetic brush is composed of various ferrite particles, such as Zn-Cu ferrite, used as the charging means, a non-magnetic conductive sleeve for supporting the charging means, and a magnetic roll enclosed within the conductive sleeve. When using a brush, for example, a fur brush made of fur treated with conductivity using carbon, copper sulfide, metal, or metal oxide can be used as the material for the fur brush and wrapped around or attached to a metal or other conductive-treated core to create a charger.

[0060] The charger is not limited to a contact-type charger as described above, but is preferred in that it provides an image forming apparatus with reduced ozone generation from the charger. Preferably, the charger is positioned in contact with or without contact with the image carrier, and the surface of the image carrier is charged by superimposing DC and AC voltages. It is also preferable that the charger is a charging roller positioned in close proximity to the image carrier with a gap tape, and the surface of the image carrier is charged by superimposing DC and AC voltages on the charging roller.

[0061] <Exposure process and exposure means> The exposure step is a step of exposing the surface of the charged image carrier, and is performed by the exposure means. The exposure can be performed, for example, by exposing the surface of the image carrier in an image-like manner using the exposure means. The optical system in the exposure is broadly classified into analog optical systems and digital optical systems. The analog optical system is an optical system that projects a document directly onto the surface of the image carrier using the optical system. The digital optical system is an optical system in which image information is given as an electrical signal, and the electrical signal is converted into an optical signal to expose the image carrier and form an image. The exposure means is not particularly limited as long as it can expose the charged image carrier to form an electrostatic latent image, and can be appropriately selected according to the purpose. Examples of exposure devices include copying optical systems, rod lens array systems, laser optical systems, liquid crystal shutter optical systems, and LED optical systems. In this invention, a back-facing method in which the image carrier is exposed in an image-like manner from the back side may also be employed.

[0062] <Developing process and developing means> The development step is a step of developing the electrostatic latent image into a toner image, and is performed by the development means. The development means is not particularly limited as long as it can develop the electrostatic latent image into a toner image, and can be appropriately selected according to the purpose. For example, it may include a developer that contains the toner and has at least a developer that can apply the toner to the electrostatic latent image by contact or non-contact. The developer may be a dry development type or a wet development type, and may be a single-color developer or a multi-color developer. For example, it may include a stirrer that frictionally agitates and charges the toner, and a rotatable magnetic roller. Inside the developer, for example, the toner and a carrier as needed are mixed and agitated, and the toner is charged by friction during this process and is held in a pile-up state on the surface of the rotating magnetic roller, forming a magnetic brush. Since the magnetic roller is located near the image carrier, a portion of the toner that constitutes the magnetic brush formed on the surface of the magnetic roller moves to the surface of the image carrier by the electrical attraction 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 unit may be a developer containing the toner, and the developer may be a one-component developer or a two-component developer. The toner may also be a one-component magnetic toner that does not use a carrier, or a non-magnetic toner. As a development method, a premix development method may be adopted, in which a premixed developer containing toner and carrier is supplied. In the premix development method, the excess amount of carrier in the developing device is discharged as excess developer. This gradually refreshes the developer in the developing device. Therefore, it is possible to extend the replacement cycle due to developer deterioration and reduce the effort required to replace the developer.

[0063] <Transfer process and transfer means> The transfer step is a step of transferring the toner image to a recording medium, and is performed by the transfer means. The transfer step preferably includes, for example, a primary transfer step of using an intermediate transfer body to transfer the toner image to the surface of the intermediate transfer body to form a composite transfer image, and a secondary transfer step of transferring the composite transfer image to a recording medium. The transfer means is not particularly limited as long as it can transfer the toner image to the recording medium, and can be appropriately selected according to the purpose, and it is preferable that it has a primary transfer means for transferring the toner image to the surface of the intermediate transfer body to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image to a recording medium. The primary transfer means and the secondary transfer means preferably have, for example, at least a transfer device for peeling and charging the toner image formed on the surface of the image carrier onto the recording medium. The transfer device is not particularly limited and can be appropriately selected according to the purpose, and examples include a corona discharge transfer device, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device, etc. There may be one transfer device or two or more transfer devices.

[0064] 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 according to the purpose. While plain paper is typical, for example, a PET base for OHP can also be used.

[0065] <Fixing process and fixing means> The fixing step is a step of fixing the toner image transferred to the recording medium, and is performed by the fixing means. When two or more toners are used, each color of toner may be fixed after it has been transferred to the recording medium, or all colors of toner may be transferred to the recording medium and fixed in a stacked state. 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 according to the purpose, and a thermal fixing method using known heating and pressing means can be adopted. The heating and pressing means is not particularly limited and can be appropriately selected according to the purpose, and examples include a combination of a heating roller and a pressing roller, or a combination of a heating roller, a pressing roller and an endless belt. The heating temperature is not particularly limited and can be appropriately selected according to the purpose, but 80°C to 200°C is preferred. If necessary, a known optical fuser may be used together with the fixing means, for example.

[0066] <Cleaning process and cleaning methods> The cleaning step is a step of removing the toner remaining on the surface of the image carrier, and is performed by the cleaning means. The cleaning means used is one in which the cleaning blade of the present invention is fixed to a support member.

[0067] The linear pressure applied by the blade base to the surface of the image carrier in the cleaning blade of the present invention is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 [N / m] or more and 100 [N / m] or less, and more preferably 10 [N / m] or more and 50 [N / m] or less. When the linear pressure is 10 [N / m] or more and 100 [N / m] or less, cleaning defects in which the toner slips through the contact portion and the image carrier become less likely to occur, and the peeling of the elastic body can be easily suppressed. The linear pressure can be measured, for example, using a measuring device incorporating a small compression type load cell manufactured by Kyowa Electric Industry Co., Ltd.

[0068] In the cleaning blade of the present invention, there are no particular restrictions on the angle (hereinafter referred to as the "cleaning angle") between the tangent to the image carrier at the position where the contact portion of the blade base contacts the image carrier and the tip surface of the free end of the blade base. However, it is preferable that the angle is 65° or more and 85° or less. When the cleaning angle is 65° or more and 85° or less, it becomes easier to suppress the occurrence of curling of the blade base and to reduce the occurrence of cleaning defects.

[0069] <Other processes and other means> Other processes include, for example, static elimination processes, recycling processes, and control processes. Other means include, for example, static elimination means, recycling means, and control means.

[0070] (Static elimination process and means of static elimination) The static elimination step is a step of eliminating static electricity by applying a static elimination bias voltage to the image carrier, and is performed by the static elimination means. The static elimination means is not particularly limited as long as it can apply a static elimination bias voltage to the image carrier, and can be appropriately selected according to the purpose, for example, a static elimination lamp.

[0071] (Recycling process and recycling methods) The recycling process involves recycling the toner removed in the cleaning process to the developing means, and is performed by the recycling means. The recycling means is not particularly limited and can be appropriately selected depending on the purpose, and examples include known transport means.

[0072] (Control process and control means) The control step is a step that controls each of the steps and is performed by 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 according to the purpose, for example, a sequencer, a computer, or other equipment.

[0073] Here, an example of an image forming apparatus according to the present invention will be described with reference to the drawings. However, the applications of the cleaning blade of the present invention are not limited in any way to these embodiments. In addition, the same reference numerals are used for identical components in each drawing, and redundant explanations may be omitted. Furthermore, the number, position, shape, etc. of the components described below are not limited to this embodiment, and can be set to a number, position, shape, etc. that is preferable for carrying out the present invention.

[0074] <Processing Cartridge> A process cartridge according to one embodiment of the present invention comprises an image carrier, at least one of the following means: a charging means for charging the surface of the image carrier, an exposure means for exposing the charged surface of the image carrier 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 to a recording medium, and a cleaning means that contacts the surface of the image carrier to remove residue from the surface of the image carrier, wherein the cleaning means has a cleaning blade. The process cartridge is detachable from the main body of the image forming apparatus and may further have other means as needed.

[0075] As shown in Figure 5, the process cartridge 1 of the image forming apparatus 500 houses an image carrier 3 and process means such as a charging roller 4, a developing device 5, a cleaning device 6, and a lubricant application device 10, all within a frame 2. The process cartridge 1 is detachable from the main body of the image forming apparatus 500. In the image forming apparatus 500, the image carrier 3 and process means are replaced as a whole unit, but it is also possible to have a configuration where the image carrier 3, charging roller 4, charging roller cleaner 8, developing device 5, cleaning device 6, and lubricant application device 10 are replaced individually with new ones.

[0076] Each image-forming unit comprises a photoreceptor drum 21 (cyan photoreceptor drum 21C, yellow photoreceptor drum 21Y, magenta photoreceptor drum 21M, and black photoreceptor drum 21BK), a charging unit that uniformly charges the photoreceptor drum 21, an exposure device 12 that exposes the photoreceptor drum 21 based on image information for each color and forms latent images of each color on the photoreceptor drum 21, a developing unit 20 (cyan developing unit 20C, yellow developing unit 20Y, magenta developing unit 20M, and black developing unit 20BK) which is a developing unit that develops the latent images with developers of each color to form toner images of each color, a transfer charger for transferring the toner images onto an intermediate transfer belt 22, a cleaning device 13, and an anti-static lamp. The charging unit is a charging component of the charging device as a means of charging, and the developing device 20 is a developing means that converts the latent image formed on the surface of the photoreceptor drum 21 into a toner image. The cleaning device 13 is a cleaning means that cleans the toner remaining on the photoreceptor drum 21 after the toner image has been transferred to the intermediate transfer belt 22. The static elimination lamp (not shown) is a static elimination means that eliminates static electricity from the surface potential of the photoreceptor drum 21 after cleaning. Although the photosensitive drum 21 is shown in a drum shape, it may also be in the form of a sheet or an endless belt. [Examples]

[0077] The following describes embodiments and reference examples of the present invention, but the present invention is not limited in any way to these embodiments. However, unless otherwise specified, "parts" refers to "parts by mass". In the following, we will describe an embodiment in which the cleaning blade substrate shown in Figure 4 consists of an elastic edge layer and a base layer.

[0078] (Preparation of particle dispersions for coating layer formation) —Preparation of particle dispersion A— [Particle dispersion A] was prepared by mixing 3.4 parts of polytetrafluoroethylene (PTFE) micropowder (TF9201Z, manufactured by 3M, volume average particle size 200 nm) as particles, 3.4 parts of polytetrafluoroethylene (PTFE) micropowder (TF9207Z, manufactured by 3M, volume average particle size 120 nm), 0.2 parts of a VdF-HFP-TFE ternary copolymer consisting of vinylidene fluoride (VdF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE) as a binder resin, and 93.0 parts of 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (HFE-347; manufactured by Tokyo Chemical Industry Co., Ltd.) as a fluorine-based dispersion solvent in a screw tube with a stirrer or the like.

[0079] —Preparation of particle dispersion B— [Particle dispersion B] was prepared by mixing 3.55 parts of polytetrafluoroethylene (PTFE) micropowder (TF9201Z, manufactured by 3M, volume average particle size 200 nm) as particles, 3.3 parts of polytetrafluoroethylene (PTFE) micropowder (TF9207Z, manufactured by 3M, volume average particle size 120 nm), 0.15 parts of a VdF-HFP-TFE ternary copolymer as a binder resin, and 93.0 parts of 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (HFE-347; manufactured by Tokyo Chemical Industry Co., Ltd.) as a fluorine-based dispersion solvent in a screw tube and stirring with a stirrer or the like.

[0080] —Preparation of particle dispersion C— [Particle dispersion C] was prepared by placing 6.8 parts of polytetrafluoroethylene (PTFE) micropowder (TF9201Z, manufactured by 3M, volume average particle size 200 nm) as particles, 0.2 parts of a VdF-HFP-TFE ternary copolymer as a binder resin, and 93.0 parts of 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether (HFE-347; manufactured by Tokyo Chemical Industry Co., Ltd.) as a fluorine-based dispersion solvent into a screw tube and stirring with a stirrer or the like.

[0081] -Preparation of particle dispersion D- [Particle dispersion D] was prepared by mixing 97.0 parts of a polymethyl methacrylic acid (PMMA) aqueous dispersion (MX100W, manufactured by Nippon Shokubai Co., Ltd., volume average particle size 150 nm) as particles and 3.0 parts of polyvinyl butyral (PVB) resin (Eslec KW-10, manufactured by Sekisui Chemical Co., Ltd., degree of acetalization 9±2 mol%) as a binder resin in a screw tube and stirring with a stirrer or the like.

[0082] —Preparation of particle dispersion E— [Particle dispersion E] was prepared by mixing 95.0 parts of an aqueous dispersion of polymethyl methacrylic acid (PMMA) (MX100W, manufactured by Nippon Shokubai Co., Ltd., volume average particle size 150 nm) as particles and 5.0 parts of polyvinyl alcohol (PVA) resin (Poval JP-03, manufactured by Nippon Vipoval Co., Ltd., degree of saponification 88±2 mol%) as a binder resin in a screw tube with a stirrer or the like.

[0083] <Example 1> (Fabrication of the blade base for cleaning blades) The edge layer and base layer were made of polyurethane elastomer sheets obtained by centrifugal molding, curing, and post-crosslinking. The average thickness and Martens hardness (HM) of the edge layer and base layer are as follows. Average thickness: 2.0 [mm] Martens hardness (HM) of the edge layer: 0.5 [N / mm²] 2 ] Martens hardness (HM) of the base layer: 1.1 [N / mm²] 2 ] A blade base was fabricated by bonding the edge layer and the base layer together. The blade base was then bonded to a metal plate.

[0084] (Formation of the coating layer: dipping) One end face (hereinafter sometimes referred to as the cleaning blade tip face) used as the tip of the cleaning blade on the circumferential surface was immersed in the [particle dispersion A] to a depth of 2 [mm] from the cleaning blade tip face, perpendicular to the horizontal plane, and was pulled up at a pulling speed of 1 [mm / s]. In order to collect the PTFE particles necessary for the cleaning function in the portion of the cleaning blade tip face including the contact edge, the cleaning blade of Example 1 was manufactured by tilting it at approximately 45° as shown in Figure 6 and drying it at room temperature (25°C) for 30 minutes. The average thickness of the coating layer was 0.5 μm.

[0085] <Examples 2-8, Comparative Examples 1-3> Except for changing the type of particle dispersion, the Martens hardness of the base layer, and the average thickness of the coating layer as shown in Table 1, cleaning blades for Examples 2-7 and Comparative Examples 1-3 were manufactured in the same manner as in Example 1. The thickness of the coating layer was controlled by the pulling speed during dipping. Increasing the pulling speed increases the thickness. Comparative Example 1 is a cleaning blade equipped with a blade base that does not have a coating layer.

[0086] <Assembly of image forming apparatus> The cleaning blades obtained from Examples 1-8 and Comparative Examples 1-3 were attached to the image carrier unit of a color multifunction printer (imagio MP C4500, manufactured by Ricoh Co., Ltd.) (the printer section had a configuration similar to that of the image forming apparatus 500 shown in Figure 4), and the image forming apparatus was assembled. The cleaning blades were attached to the image forming apparatus so that the linear pressure was 20 g / cm and the cleaning angle was 81°.

[0087] <Measurement of the unfolded surface area ratio (Sdr)> The unfolded interface area ratio Sdr was measured for the coating layer of the cleaning blades obtained in Examples 1-8 and Comparative Examples 1-3. The measurement method for the expanded interface area ratio Sdr is the one described in the "Expanded Interface Area Ratio Sdr" section above. The expanded interface area ratio Sdr shown in Table 1 represents the median value of 4 to 6 measurements taken at each measurement location.

[0088] <Measurement of Martens hardness> The Martens hardness of the base layer of the cleaning blades obtained from Examples 1-8 and Comparative Examples 1-3 was measured. The measurement method for the Martens hardness (HM) was the same as the measurement conditions described in "Measurement of Martens Hardness" above. The results are shown in Table 1. The measurement location for the Martens hardness in the base layer was 20 μm inward from the edge of the base layer. The Martens hardness values ​​shown are the median values ​​of 4 to 6 measurements taken at each measurement location.

[0089] <Measurement of average thickness in the coating layer> The average thickness of the coating layer was measured in the cleaning blades obtained from Examples 1 to 8 and Comparative Examples 1 to 3. The results are shown in Table 1. The average thickness was measured by scraping off a portion of the coating layer with a spatula or cotton swab and measuring the shape using a contact-type surface roughness meter (Surftest SJ-500: manufactured by Mitutoyo).

[0090] <Evaluation of Torque Increase Rate> Using the aforementioned image forming apparatus, output was performed under the following conditions, and the rate of change in the increase in the driving torque of the image carrier was measured. After output, the tip of the cleaning blade was observed with a laser microscope (LEXT OLS4100, manufactured by Olympus Corporation), and the torque increase rate was evaluated based on the evaluation criteria below. The evaluation results are shown in Table 1. In the evaluation criteria, "initial" refers to the period from the first to the 500th image to be output. Environment: 23℃ / 45%RH Paper feed conditions: blank chart Number of prints: 5,000 (A4 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 driving torque. Furthermore, even when the tip of the cleaning blade was observed after output, there were no signs of peeling whatsoever. ○: 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, upon inspection of the tip of the cleaning blade after output, there were signs of peeling, but it was not at a level that would cause toner to leak out, so there is no problem in practical use. ×: The image carrier stops due to increased torque, and upon inspection of the tip of the cleaning blade after output, there are traces of peeling that have caused toner to leak out, which is problematic in practical use.

[0091] <Image Quality Evaluation (Cleaning Ability)> The image forming apparatus described above was used to produce output under the following conditions. Subsequently, the tip of the cleaning blade and the surface of the image carrier were observed with a laser microscope (LEXT OLS4100, manufactured by Olympus Corporation) and evaluated based on the evaluation criteria below. The evaluation results are shown in Table 1. Environment: 27℃ / 80%RH Paper feed conditions: All solid images are processed sequentially. Number of prints: 2,000 (A4 landscape) -Evaluation Criteria- ◎: No visible toner was detected on either the printed paper or the image carrier due to poor cleaning, and no streaky toner streaks were observed on the image carrier in the longitudinal direction under a microscope. ○: Although toner that has slipped through due to poor cleaning cannot be visually confirmed on the printed paper or the image carrier, streaks of toner slippage can be confirmed when the image carrier is observed longitudinally under a microscope. ×: Due to improper cleaning, toner that has slipped through can be visually confirmed on both the printed paper and the image carrier.

[0092] [Table 1]

[0093] Examples of the present invention are as follows: <1> A cleaning blade that contacts the surface of a member to be cleaned to remove residue from the surface of the member to be cleaned, The cleaning blade comprises a cleaning blade base having an elastic member and a cleaning blade support member that supports the cleaning blade base. The elastic member has a covering layer provided on the tip portion that contacts the member to be cleaned. A cleaning blade characterized in that, in the coating layer on the lower surface of the cleaning blade base, the developed interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.2% or more and 1.8% or less. <2> In the coating layer on the lower surface of the cleaning blade base, the unfolded interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.4% or more and 1.7% or less. <1> The cleaning blade described above. <3> The thickness of the coating layer on the lower surface of the blade is 0.5 μm or more and 12 μm or less at a distance of 100 μm inward from the tip ridge of the cleaning blade. <1> or <2> The cleaning blade described above. <4> The coating layer comprises particles and a binder resin. <1> from <3> A cleaning blade as described in one of the following lists. <5> The coating layer contains a plurality of particles of different particle sizes. <1> from <4> A cleaning blade as described in one of the following lists. <6> The coating layer is at least one of the following: a coating film in which the particles are polytetrafluoroethylene particles and the binder resin is a fluororesin; and a coating film in which the particles are acrylic particles and the binder resin is a polyvinyl alcohol resin or a polyvinyl acetal resin. <4> The cleaning blade described above. <7> The base of the cleaning blade is either a single-layer structure of polyurethane rubber or a laminated structure of polyurethane rubber with different Martens hardnesses. <1> from <6> A cleaning blade as described in one of the following lists. <8> The base of the cleaning blade has a single-layer structure of polyurethane rubber, and the Martens hardness of the polyurethane rubber is 0.5 [N / mm²]. 2 ] or more 2[N / mm 2 The following is true: <7> The cleaning blade described above. <9> Image carrier and, A charging means for charging the surface of the image carrier, An exposure means for exposing the surface of the charged image carrier 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, It includes a cleaning means that contacts the surface of the image carrier to remove residue from the surface of the image carrier, The cleaning means, <1> from <8> A process cartridge having a cleaning blade as described in any one of the following. <10> Image carrier and, A charging means for charging the surface of the image carrier, An exposure means for exposing the surface of the charged image carrier 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, Fixing means for fixing the toner image transferred to the recording medium, It includes a cleaning means that contacts the surface of the image carrier to remove residue from the surface of the image carrier, The cleaning means, <1> from <8> An image forming apparatus having a cleaning blade as described in any one of the following. [Explanation of Symbols]

[0094] 1 Image-making unit 1Y Imaging Unit (for Yellow) 1C Imaging Unit (for cyan) 1M Image Production Unit (for magenta) 1K Image Production Unit (for Black) 10 Lubricant application device 100Y Toner Cartridge (for Yellow) 100C Toner Cartridge (Cyan) 100M Toner Cartridge (Magenta) 100K Toner Cartridge (Black) 101 Fur Brush 103 Solid Lubricant 103a Lubricant-pressurized spring 103b Bracket 14 Intermediate transfer belt 151 First paper feed cassette 152 Second paper feed cassette 151a First paper feed roller 152a Second paper feed roller 153 Paper feed path 154 Conveyor roller pair 162 Belt Cleaning Unit 162a Belt Cleaning Blade 2 frame 3 Image carrier 3Y Image Carrier (for Yellow) 3C Image Carrier (for cyan) 3M Image Carrier (for magenta) 3K Image Carrier (for Black) 4. Charging roller 40 Optical writing unit 41 Polygon Mirror 5. Developing device 5Y developing machine (for yellow film) 5C developing unit (for cyan) 5M developing unit (for magenta) 5K film developing machine (for black film) 51 Developing roller 52 supply screw 53 Stirring screw 54 Doctor 55 Resistola vs. 6. Cleaning device 60 Transfer Units 62 Cleaning Blades 62a Cleaning blade tip surface 62b Cleaning blade underside 62c Cleaning blade contact area 62d Cleaning blade side 621 Cleaning blade support member 622 Cleaning blade base 622a Edge layer 622b Base layer 623 Covering layer 63 First bracket 64 Second bracket 66 Secondary Transfer Backup Roller 67 Drive roller 68 Auxiliary rollers 69 Tension Roller 7. Primary transfer roller 7Y Primary Transfer Roller (for Yellow) 7C Primary Transfer Roller (for Cyan) 7M Primary Transfer Roller (for magenta) 7K Primary Transfer Roller (for Black) 70 Secondary transfer roller 8. Electrostatic roller cleaner 80 Fuser Unit 81 Pressurized heating roller 82 Fixing belt unit 83 Heating roller 84 Fixing belt 85 Tension Roller 86 Drive Roller 87 Paper output roller pair 88 Stack section 500 Image forming apparatus L laser light P recording medium [Prior art documents] [Patent Documents]

[0095] [Patent Document 1] Japanese Patent Publication No. 2000-147972 [Patent Document 2] Japanese Patent Publication No. 2004-101551 [Patent Document 3] Patent No. 3278733 [Patent Document 4] Japanese Patent Application Publication No. 10-214009 [Patent Document 5] Japanese Patent Application Publication No. 6-348193 [Patent Document 6] Japanese Patent Publication No. 2017-16083 [Patent Document 7] Patent No. 2853598

Claims

1. A cleaning blade that contacts the surface of a member to be cleaned to remove residue from the surface of the member to be cleaned, The cleaning blade comprises a cleaning blade base having an elastic member and a cleaning blade support member that supports the cleaning blade base. The elastic member has a covering layer provided on the tip portion that contacts the member to be cleaned. A cleaning blade characterized in that, in the coating layer on the lower surface of the cleaning blade base, the developed interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.2% or more and 1.8% or less.

2. The cleaning blade according to claim 1, wherein in the coating layer on the lower surface of the cleaning blade base, the unfolded interface area ratio Sdr in a 100 μm square area inward from the tip ridge is 1.4% or more and 1.7% or less.

3. The cleaning blade according to claim 1 or 2, wherein the thickness of the coating layer on the lower surface of the cleaning blade base is 0.5 μm or more and 12 μm or less at a position 100 μm inward from the tip ridge of the cleaning blade.

4. The cleaning blade according to claim 1 or 2, wherein the coating layer comprises particles and a binder resin.

5. The cleaning blade according to claim 1 or 2, wherein the coating layer contains a plurality of particles of different particle sizes.

6. The cleaning blade according to claim 4, wherein the coating layer is at least one of the following: a coating film in which the particles are polytetrafluoroethylene particles and the binder resin is a fluororesin; and a coating film in which the particles are acrylic particles and the binder resin is a polyvinyl alcohol resin or a polyvinyl acetal resin.

7. The cleaning blade according to claim 1 or 2, wherein the base of the cleaning blade is either a single-layer structure of polyurethane rubber or a laminated structure of polyurethane rubber with different Martens hardnesses.

8. The base of the cleaning blade has a single-layer structure of polyurethane rubber, and the Martens hardness of the polyurethane rubber is 0.5 [N / mm²]. ２ ] or more 2 [N / mm ２ The cleaning blade according to claim 7, wherein the cleaning blade is as follows:

9. Image carrier and, A charging means for charging the surface of the image carrier, An exposure means for exposing the surface of the charged image carrier 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, It includes a cleaning means that contacts the surface of the image carrier to remove residue from the surface of the image carrier, The cleaning means is a process cartridge having a cleaning blade according to any one of claims 1 to 8.

10. Image carrier and, A charging means for charging the surface of the image carrier, An exposure means for exposing the surface of the charged image carrier 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, Fixing means for fixing the toner image transferred to the recording medium, It includes a cleaning means that contacts the surface of the image carrier to remove residue from the surface of the image carrier, The cleaning means is an image forming apparatus having a cleaning blade according to any one of claims 1 to 8.

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