JP2015215499A - Blade member, image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade member that suppresses abnormal wear and generation of abnormal sounds in long-term use as well as has good followability at a top ridge portion thereof to a contact target member, and that achieves a longer service life, and an image forming apparatus and a process cartridge.SOLUTION: The blade member to be in contact with a contact target member such as a photoreceptor 3 has the following configuration. An elastic blade is formed of a urethane rubber having an impact resilience of 31% or lower at 23°C and a 300%-modulus of 19 MPa or more. An impregnation layer is formed of an acrylic/methacrylic resin containing an alicyclic acrylate material having a molecular weight of 200 or less in terms of a functional equivalent and 2 or more functional groups. A surface layer is formed of an acrylic/methacrylic resin containing a material having a pentaerythritol triacrylate having a molecular weight of 110 or less in terms of a functional group equivalent and 3 to 6 functional groups, as a main skeleton. The impregnation layer has a thickness of 150 μm or less.

Description

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

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus, unnecessary transfer residual toner adhering to a surface after transferring a toner image to a transfer paper or an intermediate transfer body is removed as a cleaning unit. Has been removed by.
As a cleaning member of this cleaning device, one that uses a cleaning blade that is a strip-shaped blade member is well known because it can generally be simplified in configuration and has excellent cleaning performance. The cleaning blade is made of an elastic member such as polyurethane rubber. Then, the base end of the cleaning blade is supported by a support member, the tip ridge line portion is pressed against the surface of the image carrier, and the toner remaining on the image carrier is damped and scraped off and removed.

  Patent Document 1 includes an impregnated layer formed by impregnating an acrylic / methacrylic resin material into a tip ridge portion of an elastic blade, and an acrylic / methacrylic resin material covering the tip ridge portion of the elastic blade on which the impregnated layer is formed. A cleaning blade having a surface layer is described. Specifically, urethane rubber having a JIS-A hardness of 65 to 77 degrees is used as an elastic blade, and an acrylic / methacrylic resin forming an impregnation layer and a surface layer has a functional group equivalent molecular weight of 350 or less and a functional group number of 3 to 6 A material whose main skeleton is pentaerythritol triacrylate is used. Thereby, it is possible to improve the followability of the tip ridge line portion to the image carrier while maintaining the contact pressure while suppressing the turning of the tip ridge line portion and suppressing the occurrence of abnormal wear and abnormal noise during use over time. It is stated that it will be possible.

  While maintaining the effect of the cleaning blade described in Patent Document 1, the present applicant aims to further increase the life of the cleaning blade, and the material of the elastic blade, the characteristics of the resin material to be impregnated, the thickness of the impregnation layer, The characteristics of the resin material of the surface layer were appropriately changed, and intensive experiments were conducted. As a result, the present inventors have found a combination capable of improving the wear resistance and extending the life while maintaining the effect described in Patent Document 1.

  Further, there is a need for a leveling blade that smoothes the lubricant applied to the surface of the image carrier, similar to the cleaning blade. That is, even in the leveling blade, if the tip ridge line portion is turned over, abnormal wear or abnormal noise may occur, and it is necessary to suppress turning of the tip ridge line portion. Also, if the leveling blade has poor followability of the tip ridge line to the image carrier, the film thickness of the lubricant on the surface of the image carrier cannot be maintained uniformly, so the followability of the tip ridge line to the contacted member is good. It is necessary to. Further, when the leveling blade is worn over time, the lubricant film thickness on the surface of the image carrier cannot be maintained. Therefore, it is necessary to improve the wear resistance of the leveling blade and to extend its life.

  The present invention has been made in view of the above background, the purpose of which is to suppress the occurrence of abnormal wear and abnormal noise during use over time, while being able to improve the followability to the contact member of the tip ridge line portion, And it is providing the blade member, image forming apparatus, and process cartridge which can achieve lifetime improvement.

  In order to achieve the above object, an invention according to claim 1 is directed to an elastic blade having an impregnated layer formed by impregnating an acrylic / methacrylic resin material at least at a tip ridge, and an acrylic / coating covering the tip ridge of the elastic blade. A surface layer made of a methacrylic resin material, and a blade member for bringing the tip ridge line portion into contact with the contacted member, wherein the elastic blade has a rebound elastic modulus at 23 [° C.] of 31 [%] or less, And an acrylic / methacrylic resin, which is a urethane rubber having a 300 [%] modulus of 19 [MPa] or more, and includes the alicyclic acrylate material having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more, The acrylic / methacrylic resin forming the surface layer is pentaerythritol triacrylate having a functional group equivalent molecular weight of 110 or less and a functional group number of 3-6. Include a material whose main skeleton is characterized in that the thickness of the impregnated layer and 0.99 [[mu] m] or less.

  According to the present invention, as shown in a verification experiment to be described later, it is possible to suppress the generation of abnormal wear and abnormal noise during use over time, and to improve the followability with respect to the tip ridge line portion, while extending the life. Can be achieved.

(A) is an enlarged sectional view showing a state in which the cleaning blade is in contact with the surface of the photoreceptor. (B) is an enlarged view of the vicinity of the edge portion of the cleaning blade. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. 1 is a schematic configuration diagram of an image forming unit in an example of an image forming apparatus according to an embodiment. (A) And (b) is explanatory drawing for demonstrating the measuring method of the circularity of a toner. (A) is a figure which shows the state where the front-end ridgeline part of the conventional cleaning blade was curled. (B) is a figure explaining the local abrasion of the front end surface of the conventional cleaning blade. (C) is a figure which shows the state which the front-end ridgeline part of the conventional cleaning blade was missing. The perspective view of the cleaning blade of this embodiment. Explanatory drawing of elastic power. The schematic diagram which showed the measurement location of abrasion of the cleaning blade in an Example. The conceptual diagram which compares an Example and a comparative example.

[Embodiment]
Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment (hereinafter referred to as an embodiment) of an electrophotographic printer (hereinafter simply referred to as a printer 500) will be described. First, a basic configuration of the printer 500 according to the present embodiment will be described.
FIG. 2 is a schematic configuration diagram illustrating the printer 500. The printer 500 includes four image forming units 1Y, C, M, and K for yellow, magenta, cyan, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same.

Above the four image forming units 1, a transfer unit 60 including an intermediate transfer belt 14 as an intermediate transfer member is disposed. The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K included in the image forming units 1Y, 1C, 1M, and 1K, which will be described in detail later, are superimposed on the surface of the intermediate transfer belt 14. It is a configuration to be transferred.
Further, an optical writing unit 40 is disposed below the four image forming units 1. The optical writing unit 40 serving as a latent image forming unit irradiates the photoconductors 3Y, C, M, and K of the image forming units 1Y, 1C, 1M, and 1K with a laser beam L emitted based on the image information. Thereby, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 3Y, 3C, 3M, and 3K. The optical writing unit 40 deflects the laser light L emitted from the light source by the polygon mirror 41 that is rotationally driven by a motor, and passes through the photoreceptors 3Y, 3C, 3M, and 3K via a plurality of optical lenses and mirrors. Is irradiated. In place of such a configuration, an optical scanning device using an LDE array may be employed.

  Below the optical writing unit 40, a first paper feed cassette 151 and a second paper feed cassette 152 are arranged to overlap in the vertical direction. In each of these paper feed cassettes, a plurality of transfer papers P as recording media are accommodated in a stack of paper sheets. The uppermost transfer paper P includes a first paper feed roller 151a, The second paper feed rollers 152a are in contact with each other. When the first paper feed roller 151a is rotated counterclockwise in the figure by a driving means (not shown), the uppermost transfer paper P in the first paper feed cassette 151 is vertically oriented on the right side of the cassette in the figure. The paper is discharged toward a paper feed path 153 disposed so as to extend to the front. Further, when the second paper feeding roller 152a is rotated counterclockwise in FIG. 2 by driving means (not shown), the uppermost transfer paper P in the second paper feeding cassette 152 is directed toward the paper feeding path 153. Discharged.

  A plurality of conveying roller pairs 154 are arranged in the paper feed path 153. The transfer paper P sent to the paper feed path 153 is conveyed from the lower side to the upper side in FIG. 2 while being sandwiched between the rollers of the conveyance roller pair 154.

  A registration roller pair 55 is disposed at the downstream end of the paper feed path 153 in the transport direction. The registration roller pair 55 temporarily stops the rotation of both rollers as soon as the transfer paper P sent from the transport roller pair 154 is sandwiched between the rollers. Then, the transfer paper P is sent out toward a secondary transfer nip described later at an appropriate timing.

FIG. 3 is a configuration diagram showing a schematic configuration of one of the four image forming units 1.
As shown in FIG. 3, the image forming unit 1 includes a drum-shaped photoconductor 3 as an image carrier. The photosensitive member 3 has a drum shape, but may be a sheet shape or an endless belt shape.
Around the photoreceptor 3, a charging roller 4, a developing device 5, a primary transfer roller 7, a cleaning device 6, a lubricant application device 10, a static elimination lamp (not shown), and the like are disposed. The charging roller 4 is a charging member provided in a charging device as a charging unit, and the developing device 5 is a developing unit that converts a latent image formed on the surface of the photoreceptor 3 into a toner image. The primary transfer roller 7 is a primary transfer member provided in a primary transfer device as a primary transfer unit that transfers a toner image on the surface of the photoreceptor 3 to the intermediate transfer belt 14. The cleaning device 6 is a cleaning unit that cleans the toner remaining on the photoreceptor 3 after the toner image is transferred to the intermediate transfer belt 14. The lubricant application device 10 is a lubricant application unit that applies a lubricant onto the surface of the photoreceptor 3 after the cleaning device 6 performs cleaning. A neutralizing lamp (not shown) is a neutralizing unit that neutralizes the surface potential of the photoreceptor 3 after cleaning.

The charging roller 4 is arranged in a non-contact manner with a predetermined distance from the photoconductor 3, and charges the photoconductor 3 to a predetermined polarity and a predetermined potential. The surface of the photoreceptor 3 uniformly charged by the charging roller 4 is irradiated with laser light L from an optical writing unit 40 serving as a latent image forming unit based on image information, thereby forming an electrostatic latent image.
The developing device 5 has a developing roller 51 as a developer carrier. A developing bias is applied to the developing roller 51 from a power source (not shown). In the casing of the developing device 5, a supply screw 52 and a stirring screw 53 are provided for stirring the developer contained in the casing while conveying the developer in opposite directions. A doctor 54 for regulating the developer carried on the developing roller 51 is also provided. The toner in the developer stirred and conveyed by the two screws of the supply screw 52 and the stirring screw 53 is charged to a predetermined polarity. The developer is pumped up on the surface of the developing roller 51, and the developer pumped up is regulated by the doctor 54, and the toner adheres to the latent image on the photoconductor 3 in the development area facing the photoconductor 3. .

  The cleaning device 6 includes a fur brush 101, a cleaning blade 62, and the like. The cleaning blade 62 is in contact with the photoconductor 3 in the counter direction with respect to the surface movement direction of the photoconductor 3. Details of the cleaning blade 62 will be described later. The lubricant application device 10 includes a solid lubricant 103, a lubricant pressure spring 103 a, and the like, and uses a fur brush 101 as an application brush for applying the solid lubricant 103 onto the photoreceptor 3. The solid lubricant 103 is held by the bracket 103b and is pressed toward the fur brush 101 by a lubricant pressurizing spring 103a. Then, the solid lubricant 103 is scraped by the fur brush 101 that rotates in the rotational direction with respect to the rotation direction of the photoconductor 3, and the lubricant is applied onto the photoconductor 3. By applying lubricant to the photoreceptor, the friction coefficient on the surface of the photoreceptor 3 is maintained at 0.2 or less during non-image formation. The lubricant applied on the photoreceptor 3 is leveled by the leveling blade 103c as a blade member.

  The charging device according to the present embodiment is a non-contact proximity arrangement system in which the charging roller 4 is brought close to the photosensitive member 3, and examples of the charging device include corotron, scorotron, and solid state charger (solid state charger). A known configuration can be used. Among these charging methods, the contact charging method or the non-contact proximity arrangement method is more desirable, and has advantages such as high charging efficiency, a small amount of ozone generation, and miniaturization of the apparatus.

The light source of the laser light L of the optical writing unit 40 and the light source such as a static elimination lamp include a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). ) And other luminescent materials can be used.
In addition, various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Among these light sources, light emitting diodes and semiconductor lasers are used favorably because they have high irradiation energy and have long wavelength light of 600 to 800 [nm].

  In addition to the intermediate transfer belt 14, the transfer unit 60 serving as transfer means includes a belt cleaning unit 162, a first bracket 63, a second bracket 64, and the like. Also provided are four primary transfer rollers 7Y, 7C, 7M, 7K, secondary transfer backup roller 66, drive roller 67, auxiliary roller 68, tension roller 69, and the like. The intermediate transfer belt 14 is endlessly moved in the counterclockwise direction in the drawing by the rotational driving of the driving roller 67 while being stretched around these eight roller members. The four primary transfer rollers 7Y, 7C, 7M, and 7K each have an intermediate transfer belt 14 that is endlessly moved in this manner, and forms a primary transfer nip between the photoreceptors 3Y, 3C, 3M, and 3K. . Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 14. The intermediate transfer belt 14 sequentially passes through the primary transfer nips for Y, C, M, and K along with the endless movement thereof, and on the surface of the photoreceptor 3Y, C, M, K on the front surface. Y, C, M, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 14.

  The secondary transfer backup roller 66 sandwiches the intermediate transfer belt 14 with the secondary transfer roller 70 disposed outside the loop of the intermediate transfer belt 14 to form a secondary transfer nip. The registration roller pair 55 described above feeds the transfer paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the transfer paper P can be synchronized with the four-color toner image on the intermediate transfer belt 14. The four-color toner image on the intermediate transfer belt 14 is affected by the secondary transfer electric field formed between the secondary transfer roller 70 to which the secondary transfer bias is applied and the secondary transfer backup roller 66, and the influence of the nip pressure. The secondary transfer is performed on the transfer paper P in the secondary transfer nip. Then, combined with the white color of the transfer paper P, a full color toner image is obtained.

  Transfer residual toner that has not been transferred to the transfer paper P adheres to the intermediate transfer belt 14 after passing through the secondary transfer nip. This is cleaned by the belt cleaning unit 162. The belt cleaning unit 162 has a belt cleaning blade 162a in contact with the front surface of the intermediate transfer belt 14, thereby scraping off and removing the transfer residual toner on the intermediate transfer belt 14.

  The first bracket 63 of the transfer unit 60 swings at a predetermined rotation angle about the rotation axis of the auxiliary roller 68 as the solenoid (not shown) is turned on / off. When forming a monochrome image, the printer 500 rotates the first bracket 63 a little counterclockwise in the drawing by driving the solenoid described above. By this rotation, the primary transfer rollers 7Y, C, and M for Y, C, and M are revolved counterclockwise in the drawing around the rotation axis of the auxiliary roller 68, so that the intermediate transfer belt 14 is rotated in the Y, C, and Y directions. It is separated from the photoconductors 3Y, 3C, 3M for M. Of the four image forming units 1Y, 1C, 1M, and 1K, only the K image forming unit 1K is driven to form a monochrome image. Accordingly, it is possible to avoid wear of each member constituting the image forming unit 1 due to wasteful driving of the Y, C, M image forming unit 1 during monochrome image formation.

  A fixing unit 80 is disposed above the secondary transfer nip in the drawing. The fixing unit 80 includes a pressure heating roller 81 that contains a heat source such as a halogen lamp, and a fixing belt unit 82. The fixing belt unit 82 includes a fixing belt 84 as a fixing member, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a driving roller 86, a temperature sensor (not shown), and the like. Then, the endless fixing belt 84 is endlessly moved in the counterclockwise direction in the drawing while being stretched by the heating roller 83, the tension roller 85, and the driving roller 86. In the process of endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. A pressure heating roller 81 that is driven to rotate in the clockwise direction in the drawing is in contact with the surface of the fixing belt 84 that is heated in this manner, around the heating roller 83. Thus, a fixing nip where the pressure heating roller 81 and the fixing belt 84 abut is formed.

  A temperature sensor (not shown) is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap, and the fixing belt 84 just before entering the fixing nip. Detect surface temperature. This detection result is sent to a fixing power supply circuit (not shown). The fixing power supply circuit performs on / off control of power supply to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure heating roller 81 based on the detection result of the temperature sensor.

  The transfer paper P that has passed through the secondary transfer nip described above is separated from the intermediate transfer belt 14 and then sent into the fixing unit 80. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched between the fixing nips in the fixing unit 80, the full-color toner image is fixed on the transfer paper P by being heated and pressed by the fixing belt 84. The

  The transfer paper P subjected to the fixing process in this manner is discharged between the discharge roller pair 87 and then discharged outside the apparatus. A stack unit 88 is formed on the upper surface of the housing of the printer 500 main body, and the transfer paper P discharged to the outside by the discharge roller pair 87 is sequentially stacked on the stack unit 88.

  Above the transfer unit 60, four toner cartridges 100Y, 100C, M, and K that store Y, C, M, and K toners are disposed. The Y, C, M, and K toners in the toner cartridges 100Y, 100C, M, and K are appropriately supplied to the developing devices 5Y, 5C, 5M, and 5K of the image forming units 1Y, 1C, 1M, and 1K. The toner cartridges 100Y, 100C, 100M, and 100K are detachable from the printer main body independently of the image forming units 1Y, 1C, 1M, and 1K.

Next, an image forming operation in the printer 500 will be described.
When a print execution signal is received from an operation unit (not shown) or the like, a predetermined voltage or current is sequentially applied to the charging roller 4 and the developing roller 51 at a predetermined timing. Similarly, a predetermined voltage or current is sequentially applied to the optical writing unit 40 and a light source such as a static elimination lamp at a predetermined timing. In synchronization with this, the photosensitive member 3 is rotationally driven in the direction of the arrow in the figure by a photosensitive member driving motor (not shown) as a driving means.

When the photoconductor 3 rotates in the direction of the arrow in the figure, the surface of the photoconductor 3 is first uniformly charged to a predetermined potential by the charging roller 4. Then, the laser beam L corresponding to the image information is irradiated onto the photoconductor 3 from the optical writing unit 40, and the portion irradiated with the laser light L on the surface of the photoconductor 3 is neutralized to form an electrostatic latent image. .
The surface of the photoreceptor 3 on which the electrostatic latent image is formed is rubbed by a developer magnetic brush formed on the developing roller 51 at a portion facing the developing device 5. At this time, the negatively charged toner on the developing roller 51 is moved to the electrostatic latent image side by a predetermined developing bias applied to the developing roller 51 to be converted into a toner image (development). In each image forming unit 1, a similar image forming process is executed, and a toner image of each color is formed on the surface of each photoreceptor 3Y, C, M, K of each image forming unit 1Y, C, M, K. .
As described above, in the printer 500, the electrostatic latent image formed on the photoconductor 3 is reversely developed by the developing device 5 with the negatively charged toner. In this embodiment, an example using a non-contact charging roller system of N / P (negative positive: toner adheres to a place where the potential is low) has been described, but the present invention is not limited to this.

The toner images of the respective colors formed on the surfaces of the photoreceptors 3Y, 3C, 3M, and 3K are sequentially primary-transferred so as to overlap on the surface of the intermediate transfer belt 14. As a result, a four-color toner image is formed on the intermediate transfer belt 14.
The four-color toner image formed on the intermediate transfer belt 14 is fed from the first paper feed cassette 151 or the second paper feed cassette 152, passed between the rollers of the registration roller pair 55, and fed to the secondary transfer nip. The transfer paper P is transferred. At this time, the transfer paper P is temporarily stopped while being sandwiched between the registration roller pair 55, and is supplied to the secondary transfer nip in synchronization with the leading edge of the image on the intermediate transfer belt 14. The transfer paper P onto which the toner image has been transferred is separated from the intermediate transfer belt 14 and conveyed to the fixing unit 80. Then, the transfer paper P on which the toner image is transferred passes through the fixing unit 80, whereby the toner image is fixed on the transfer paper P by the action of heat and pressure, and the transfer paper P on which the toner image is fixed is the printer. 500 is discharged outside the apparatus and stacked on the stack unit 88.

On the other hand, the transfer residual toner on the surface of the intermediate transfer belt 14 that has transferred the toner image onto the transfer paper P at the secondary transfer nip is removed by the belt cleaning unit 162.
Further, the surface of the photoreceptor 3 on which the toner images of the respective colors are transferred to the intermediate transfer belt 14 at the primary transfer nip, the residual toner after the transfer is removed by the cleaning device 6, and the lubricant is applied by the lubricant applying device 10. Thereafter, the charge is removed by a charge removal lamp.

  As shown in FIG. 3, the image forming unit 1 of the printer 500 includes a photosensitive member 3 and a charging roller 4, a developing device 5, a cleaning device 6, a lubricant applying device 10, and the like as process means. Yes. The image forming unit 1 can be integrally attached to and detached from the main body of the printer 500 as a process cartridge. Further, the photoconductor 3, the charging roller 4, the developing device 5, the cleaning device 6, and the lubricant applying device 10 may be replaced with new ones.

Next, toner suitable for the printer 500 to which the present invention is applied will be described.
As the toner used in the printer 500, it is preferable to use a polymerized toner produced by a suspension polymerization method, an emulsion polymerization method, or a dispersion polymerization method, which can easily increase the circularity and reduce the particle size, in order to improve the image quality. In particular, it is preferable to use a polymerized toner having a circularity of 0.97 or more and a volume average particle size of 5.5 [μm] or less. By using a material having an average circularity of 0.97 or more and a volume average particle size of 5.5 [μm], a higher resolution image can be formed.

  The “circularity” here is an average circularity measured by a flow type particle image analyzer FPIA-2000 (trade name, manufactured by Toa Medical Electronics Co., Ltd.). Specifically, a surfactant, preferably an alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 [ml] as a dispersant in 100 to 150 [ml] of water from which impure solids have been removed in advance. Further, about 0.1 to 0.5 [g] of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes so that the concentration of the dispersion becomes 3000 to 1 [10,000 / μl]. To measure the shape and distribution of the toner. Based on this measurement result, the outer peripheral length of the actual toner projection shape shown in FIG. 4A is C1, and the projection area is S. The outer circumference of the perfect circle shown in FIG. C2 / C1 was determined when the length was C2, and the average value was defined as the circularity.

  The volume average particle diameter can be determined by a Coulter counter method. Specifically, the toner number distribution and volume distribution data measured by the Coulter Multisizer 2e type (manufactured by Coulter) are sent to a personal computer via an interface (manufactured by Nikkaki Co., Ltd.) for analysis. More specifically, a 1% NaCl aqueous solution using first grade sodium chloride is prepared as an electrolytic solution. Then, 0.1 to 5 [ml] of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 [ml] of the electrolytic aqueous solution. Further, 2 to 20 [mg] of toner as a test sample is added thereto, and dispersion treatment is performed for about 1 to 3 [minutes] with an ultrasonic disperser. Then, 100 to 200 [ml] of the electrolytic aqueous solution is put into another beaker, and the solution after the dispersion treatment is added to the beaker so as to have a predetermined concentration, and then applied to the Coulter Multisizer 2e type. The aperture is 100 [μm], and the particle size of 50,000 toner particles is measured. As a channel, it is less than 2.00-2.52 [micrometer]; 2.52-less than 3.17 [micrometer]; 3.17-less than 4.00 [micrometer]; 4.00-5.04 [micrometer] Less than 5.04 to 6.35 [μm]; 6.35 to less than 8.00 [μm]; 8.00 to less than 10.08 [μm]; 10.08 to less than 12.70 [μm]; 12.70 to less than 16.00 [μm]; 16.00 to less than 20.20 [μm]; 20.20 to less than 25.40 [μm]; 25.40 to less than 32.00 [μm]; Using 13 channels of 00 to less than 40.30 [μm], toner particles with a particle size of 2.00 [μm] or more and 32.0 [μm] or less are targeted. Then, the volume average particle diameter is calculated based on the relational expression “volume average particle diameter = ΣXfV / ΣfV”. However, “X” is the representative diameter in each channel, “V” is the equivalent volume in the representative diameter of each channel, and “f” is the number of particles in each channel.

  In such a polymerized toner, even if an attempt is made to remove the pulverized toner with the cleaning blade 62 in the same manner as when the conventional pulverized toner is removed from the surface of the photoreceptor 3, the polymerized toner cannot be sufficiently removed from the surface of the photoreceptor 3. A cleaning failure occurs. This is because the polymerized toner having a small particle size and excellent sphericity passes through a slight gap formed between the blade and the image carrier.

  In order to suppress such slip-through, it is necessary to increase the cleaning pressure by increasing the contact pressure between the photosensitive member 3 and the cleaning blade. However, when the contact pressure of the cleaning blade is increased, the frictional force between the photosensitive member 3 and the cleaning blade 62 increases as shown in FIG. As a result, the cleaning blade 62 is pulled in the moving direction of the photosensitive member 3 and the leading edge portion 62c of the cleaning blade 62 is turned up. When the turned cleaning blade 62 is restored to its original state against the turn, abnormal noise may occur.

  Further, if the cleaning is continued with the leading edge portion 62c of the cleaning blade 62 turned up, as shown in FIG. 5B, the cleaning blade 62 is separated from the leading edge portion 62c of the blade leading surface 62a by several [μm]. Local wear will occur at the spot. If the cleaning is further continued in such a state, the local wear becomes large, and finally, the leading edge portion 62c is lost as shown in FIG. If the leading edge portion 62c is missing, the toner cannot be properly cleaned, resulting in poor cleaning.

  As a conventional configuration, Japanese Patent No. 3602898 discloses a cleaning blade in which a resin having a pencil hardness of B to 6H is coated on at least a tip ridge line portion of an elastic blade made of polyurethane elastomer. Japanese Patent No. 3602898 also describes a cleaning blade in which at least the tip ridge line portion of an elastic blade made of polyurethane elastomer is impregnated with a resin having a pencil hardness of B to 6H.

  Japanese Patent Application Laid-Open No. 2004-233818 discloses a cleaning blade in which an ultraviolet curable material containing silicone is impregnated into a rubber member of an elastic blade to swell, and then the ultraviolet curable material is cured by ultraviolet irradiation treatment. Have been described.

  However, as in the cleaning blade of Japanese Patent No. 3602898, even if only the surface layer is provided and the friction coefficient is reduced, the surface layer wears and decreases over time, which is not impregnated, The low elastic blade is exposed and directly contacts the surface of the photoreceptor 3. As a result, the friction coefficient between the cleaning blade and the surface of the photoreceptor increases, and abnormal wear and abnormal noise occur. Therefore, if the surface layer is made thick so that it can withstand long-term use, elastic deformation at the tip ridge line portion of the elastic blade may be hindered, resulting in poor cleaning. Further, the posture control of the tip ridge line portion is impaired, and the durability is lowered. Moreover, the cleaning blade described in Japanese Patent No. 3602898 has a pencil hardness of B to 6H, and even if it is used as a surface layer, the pencil hardness is not sufficient and the durability is poor.

  In the cleaning blade in which the elastic blade is impregnated with resin and the surface of the elastic blade is hardened, the hardness of the impregnated layer that comes into contact with the photosensitive member of the cleaning blade at the beginning of use is so high that the surface layer is provided. It cannot be obtained and wear resistance is insufficient. Further, if an impregnation layer is formed so that the hardness of the elastic blade surface is equivalent to that of the surface layer, it is necessary to impregnate the elastic blade with a large amount of ultraviolet curable material. When a rubber member impregnated with a large amount of ultraviolet curable material is irradiated with ultraviolet rays, the impregnated part is excessively hard and excessively deep, and the elasticity of the rubber member is hindered. Followability is reduced.

  In Japanese Patent Application Laid-Open No. 2004-233818, the surface layer is also formed by the impregnated resin. However, the surface layer is different from the impregnated resin in the present embodiment in which the surface layer is provided. In addition, when the impregnation is performed for 12 hours as in the impregnation operation described in JP-A-2004-233818, the amount of the acrylic / methacrylic resin impregnated becomes excessive, and the base rubber swells too much, resulting in a rubber network structure. It is destroyed, the mechanical strength is lowered, and the durability is lowered.

  Therefore, in the cleaning blade of this embodiment, the portion including the tip ridge line portion of the elastic blade is impregnated with acrylic / methacrylic resin, and a surface layer harder than the elastic blade is provided on the surface of the elastic blade including the tip ridge line portion. . By providing a surface layer harder than the elastic blade on the surface including the tip ridge line portion, the amount of acrylic / methacrylic resin impregnated in the portion including the tip ridge line portion can be adjusted regardless of the hardness of the outermost surface of the tip ridge line portion. I can do it. Thereby, it is possible to reduce the amount of impregnation, and it is possible to suppress a decrease in the followability of the tip ridge line portion to the surface of the photoreceptor due to the impregnated portion being formed excessively hard and excessively deep. Furthermore, even if the surface layer is thinned and the elastic blade comes into contact with the photoreceptor in a short time during use over time, there is an impregnated layer having a higher hardness than the elastic blade in which the base material of the elastic blade and the acrylic / methacrylic resin are mixed. Contact the photoconductor. Therefore, the occurrence of abnormal wear and abnormal noise during use over time can be suppressed. As a result, the surface layer can be made thin, and a decrease in the followability of the tip ridge line portion to the surface of the photoreceptor due to the thickening of the surface layer can be suppressed. This will be specifically described below.

FIG. 6 is a perspective view of the cleaning blade 62 of this embodiment, and FIG. 1 is an enlarged cross-sectional view of the cleaning blade 62. FIG. 1A is an explanatory diagram showing a state in which the cleaning blade 62 is in contact with the surface of the photosensitive member 3, and FIG. 1B is an enlarged explanatory diagram in the vicinity of the tip ridge line portion 62 c of the cleaning blade 62. .
The cleaning blade 62 includes a strip-shaped holder 621 made of a rigid material such as metal or hard plastic, and a strip-shaped elastic blade 622.
The elastic blade 622 is fixed to one end side of the holder 621 with an adhesive or the like, and the other end side of the holder 621 is cantilevered by the case of the cleaning device 6.

  In the cleaning blade 62 of this embodiment, the base material of the elastic blade 622 is impregnated with acrylic / methacrylic resin by dip coating, and the impregnated layer 62d is irradiated with ultraviolet rays to cure the impregnated acrylic / methacrylic resin. Is forming. Thereby, the modification | reformation effect which raises the hardness of the front-end | tip ridgeline part 62c can be produced. The impregnation treatment with the acrylic / methacrylic resin on the tip ridge line portion 62c of the elastic blade 622 can be performed by brush coating, spray coating, or the like in addition to dip coating.

  A surface layer 623 is formed on the blade tip surface 62a and the blade lower surface 62b over the blade longitudinal direction. The surface layer 623 is formed by impregnating the elastic blade 622 with acrylic / methacrylic resin and air-drying it for a predetermined time, and then coating the tip ridge portion 62c of the cleaning blade 62 by spray coating, dip coating, screen printing, etc. It is formed by irradiation.

  The timing of irradiating the ultraviolet rays to cure the acrylic / methacrylic resin impregnated in the elastic blade 622 may be either after impregnating the acrylic / methacrylic resin or after coating with the surface layer 623. However, it is preferable to irradiate the elastic blade 622 with ultraviolet rays between the impregnation of the acrylic / methacrylic resin and the coating of the surface layer 623. This can fix the impregnation state of the acrylic / methacrylic resin in which the elastic blade 622 is impregnated with the acrylic / methacrylic resin before applying the resin forming the surface layer. Therefore, the impregnation state does not change, and the elastic blade 622 in a desired impregnation state can be created.

  The elastic blade 622 preferably has a high resilience rate so that it can follow the eccentricity of the photosensitive member 3 and minute undulations on the surface of the photosensitive member 3, and urethane rubber is preferable. As the elastic blade 622, it is preferable to use urethane rubber having a rebound resilience of 31 [%] or less at 23 [° C.] and a 300 [%] modulus in a tensile test of 19 [MPa] or more. Those that do not satisfy this condition have a low crosslinking density inherent in the rubber, so that a sufficient reforming effect, that is, a durability improving effect cannot be obtained unless a large amount of acrylic / methacrylic resin is impregnated. However, when a large amount of acrylic / methacrylic resin is impregnated, the rubber swells and the angle of the tip ridge line portion 92c (the angle formed between the blade lower surface 62b and the blade tip surface 62a) cannot be maintained at 90 °. As a result, the straightness of the ridge line also decreases, and the cleaning performance decreases. In contrast, urethane rubber having a high crosslinking density that satisfies the above conditions can be sufficiently improved by impregnation with a relatively small amount of acrylic / methacrylic resin, improving wear resistance, and providing an elastic blade. It can be cured moderately. Thereby, the large deformation of the elastic blade can be suppressed, and the cleaning performance can be improved.

  In the present embodiment, the elastic blade 622 is impregnated with an acrylic / methacrylic resin to impregnate an isocyanate compound, a fluorine compound, a silicone compound, or the like, which is more durable than the case described in JP2010-152295A. Improvements can be made. This is thought to be due to the following reasons.

First of all, it is possible that the crosslink density of the rubber itself is artificially increased and the wear resistance is improved by the formation of an acrylic / methacrylic resin network chain inside the rubber. In this case, the point is that the acrylic / methacrylic resin and urethane rubber will hardly be chemically bonded. In general, when reinforcing urethane rubber by an impregnation operation, isocyanate is often used as an impregnation material. However, since isocyanate reacts chemically with urethane rubber, the crosslink density increases too much, making it more like glass than rubber. For this reason, it is conceivable that the movement of the edge is excessively suppressed and the wear resistance is deteriorated.
Another possibility is that the impregnated acrylic / methacrylic resin exerts a so-called “anchor effect” on the acrylic / methacrylic resin added to the surface to increase the adhesion between the resin film and the rubber. Can be considered. Accordingly, it can be considered that the durability of the acrylic / methacrylic resin itself is raised.

  If an acrylic / methacrylic resin having a large functional group equivalent molecular weight is used as the acrylic / methacrylic resin forming the impregnation layer 62d, the resin does not penetrate into the elastic blade 622. As a result, the elastic blade 622 cannot be modified to an appropriate range. Therefore, when the surface layer 623 is worn over time and the elastic blade comes into contact with the photosensitive member 3 and the elastic blade is worn, the impregnated layer 62d disappears early. As a result, the effect of wear resistance of the cleaning blade by the impregnation treatment cannot be sufficiently obtained. Moreover, even if the functional group equivalent molecular weight is small, if a material having a large number of functional groups is used, the crosslink density increases too much, and the state becomes closer to glass than rubber. Therefore, the movement of the tip ridge line portion is excessively suppressed, and conversely, the wear resistance is deteriorated.

  Therefore, as the acrylic / methacrylic resin forming the impregnation layer 62d, a material having a small functional group equivalent molecular weight and a small number of functional groups is preferable. In the present embodiment, a material containing an alicyclic acrylate monomer having at least a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more is used as the acrylic / methacrylic resin forming the impregnation layer 62d. Thereby, it can suppress that the crosslinking density of the impregnation layer 62d of the elastic blade 622 increases too much, and can have moderate elasticity. Therefore, the tip ridge line portion 62c can be appropriately deformed in the direction of movement of the surface of the photoreceptor 3, and deterioration of wear resistance can be suppressed. Further, the elastic blade can be sufficiently penetrated into the elastic blade 622, and the elastic blade can be modified to an appropriate range. Thereby, the wear of the elastic blade 622 after the inside is exposed due to surface layer wear can be suppressed over time, and good cleaning properties can be obtained over time.

  Further, as indicated by the arrow in FIG. 1B, the impregnated layer 62d is impregnated so that the inside of the elastic blade 622 is inclined such that the content of acrylic / methacrylic resin with respect to urethane rubber is reduced. ing. Specifically, the amount of acrylic / methacrylic resin to be impregnated is reduced by performing the impregnation operation for a short time or under conditions that are difficult to impregnate, and the amount of impregnation on the outer side of the elastic blade 622 in the impregnated portion is reduced. The impregnation operation is performed so that the amount of impregnation decreases toward the inside. When the amount of change in Martens hardness of the rubber exceeds 5% exceeding 150 μm, the vicinity of the tip ridge line portion of the elastic blade 622 is too hard and resinized. As a result, the movement of the tip ridge line portion is excessively suppressed, and conversely the wear resistance is deteriorated.

In the present embodiment, cyclohexanone having a low penetration rate into rubber is used as a dilution solvent for the acrylic / methacrylic resin, and the impregnation operation is performed by a dipping method, and the impregnation time is 120 [seconds]. By using a diluting solvent having a slow penetration rate into the rubber and setting the impregnation time to 120 [seconds], the amount of the acrylic / methacrylic resin impregnated can be suppressed. The content of the methacrylic resin can be given a gradient. If the impregnated layer is not inclined, the diluting solvent having a high penetration rate into the rubber is used or the impregnation operation is performed for a long time. As a result, the impregnation material (acrylic / methacrylic resin) can sufficiently penetrate into the base material (urethane rubber of the elastic blade 622), and a kind of equilibrium state can be created. As a result, an impregnated layer having a uniform composition and no gradient can be created.
In the present embodiment, an appropriate amount is impregnated by using a material containing an alicyclic acrylate monomer having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more and using cyclohexanone as a diluent solvent and setting the impregnation time to 120 [seconds]. And can be inclined.

  The cleaning blade 62 of the present embodiment can obtain the following effects by allowing the acrylic / methacrylic resin to be inclined with respect to the base material of the elastic blade 622 inside the surface layer 623 having high hardness. it can. That is, by imparting inclination, the elastic blade does not become too hard even when the acrylic / methacrylic resin is impregnated deep inside the elastic blade, and the mechanical strength and rigidity of the elastic blade 622 can be moderately strengthened. it can. As a result, the behavior of the blade tip can be moderately suppressed during sliding with the surface of the photosensitive member 3, and good cleaning can be performed. In addition, the occurrence of abnormal wear and abnormal noise can be suppressed, and high wear resistance can be exhibited. Further, even after the inside is exposed due to surface layer wear, wear resistance by the impregnated layer 62d can be obtained over time. Thereby, a long-life cleaning blade capable of maintaining good cleaning properties over time can be obtained.

  The surface layer 623 is formed on the blade tip surface 62a and the blade lower surface 62b of the elastic blade 622, and covers the tip ridge line portion 62c. The surface layer 623 is a member having a hardness higher than that of the elastic blade 622. Thereby, the vicinity of the tip ridge line portion 62c of the cleaning blade can be made rigid, hardly deformed, and the tip ridge line portion 62c of the cleaning blade 62 can be prevented from being turned up.

  The material of the surface layer 623 is preferably a resin, more preferably an acrylic / methacrylic resin. By using acrylic / methacrylic resin, the surface layer 623 having a desired hardness can be obtained simply by irradiating the resin adhering to the tip ridge line portion 62c of the cleaning blade 62 with ultraviolet rays, and the cleaning blade 62 can be manufactured at low cost. can do.

  As the acrylic / methacrylic resin, it is preferable to use a monomer having a functional group equivalent molecular weight of 110 or less and a functional group number of 3 to 6 pentaerythritol triacrylate as a main skeleton. If the functional group equivalent molecular weight exceeds 110 or a material other than the pentaerythritol triacrylate skeleton is used, the surface layer 623 becomes brittle. As a result, the tip ridge line portion 62c of the cleaning blade 62 is turned up, leading to wear of the tip surface as shown in FIG. 5B, and it becomes impossible to maintain the cleaning property for a long time.

  In addition to the pentaerythritol / triacrylate skeleton material, an acrylate material having 1 to 2 functional groups can be appropriately mixed as a material for the surface layer 623. Thus, flexibility can be imparted to the surface layer 623, and the properties of the surface layer 623 can be customized in accordance with the characteristics of the machine on which the cleaning blade 62 is mounted. Therefore, it is possible to improve environmental characteristics and the like, for example, by finely adjusting the blade behavior when abnormal noise occurs in a specific environment.

  Further, it is preferable to mix a monomer containing a perfluoropolyether skeleton with the acrylic / methacrylic resin forming the surface layer 623. By mixing this acrylate, the slidability of the surface layer 623 can be improved, and the turning of the tip ridge line portion can be suppressed.

Also, the Martens hardness of both the blade lower surface 62b and the blade tip surface 62a of the cleaning blade is 0.8 to 5.0 [N / mm ² ] when measured in the range from the tip ridge line portion 62c to 1000 μm. Is preferred. The surface layer 623 is preferably formed so as to have an elastic power of 60 to 90%.

  The Martens hardness on the surface of the cleaning blade 62 was pushed in with a Vickers indenter 9.8 [mN] in 30 seconds using a micro hardness tester HM-2000 manufactured by Fischer Instruments, and held for 5 seconds. Measured by pulling out in 30 seconds with a force of 8 [mN]. The elastic power is a characteristic value obtained as follows from the accumulated stress at the time of measuring Martens hardness. If the accumulated stress when pushing the Vickers indenter is Wplast and the accumulated stress at the test load unloading temple is Welast, the elastic power is a characteristic value defined by the equation Welast / Wplast × 100% (see FIG. 7). . The higher the elastic power, the smaller the hysteresis loss (plastic deformation), that is, the higher the rubber property. If the elastic power is too low, it is closer to glass than rubber.

If there is a location where the Martens hardness exceeds 5.0 [N / mm ² ] within the range from the tip ridge line portion 62c to 1000 [μm], the rigidity of the tip ridge line portion 62c of the cleaning blade 62 becomes too strong. The behavior in sliding with the surface of the photoreceptor 3 becomes too small. As a result, the vibration energy concentrates on the tip ridge line portion 62c, so that unpleasant noise is likely to be generated, and the wear rate is increased, which may make it impossible to use the device at an early stage.

Further, if there is a location where the Martens hardness exceeds 5.0 [N / mm ² ] within the range from the tip ridge line portion 62c to 1000 [μm] on the lower surface of the blade, the tip ridge line portion 62c contacts the photoreceptor 3. When contacted, the lower surface of the blade may not be elastically deformed sufficiently. As a result, the restoring force against the elastic deformation acting in the direction in which the leading edge portion 62c of the cleaning blade increases the contact pressure on the surface of the photosensitive member 3 is hardly obtained. For this reason, the leading edge ridge portion 62c cannot follow the eccentricity or minute undulation of the photosensitive member 3. Therefore, the contact pressure with respect to the photosensitive member 3 fluctuates, and the contact pressure decreases under severe conditions such as receiving a large pressing force from the toner dammed to the leading edge portion 62c, such as during continuous solid image formation. Then, the toner may slip through the cleaning blade 62 and cause a cleaning failure.

Further, if there is a portion where the Martens hardness is less than 0.8 [N / mm ² ] within the range from the blade bottom surface and the tip ridge line portion 62c of the blade tip surface to 1000 [μm], the tip ridge line portion of the cleaning blade The vicinity of 62c is too soft. As a result, the deformation of the tip ridge line portion 62c becomes excessively large and wears out early, and the cleaning property cannot be maintained.

By forming a cleaning blade on both the blade tip surface 62a and the blade lower surface 62b so that the Martens hardness is 0.8 to 5.0 [N / mm ² ] in the range of 1000 μm from the tip ridge line portion 62c, the tip ridge line A part can be made into moderate rigidity. Thereby, a front-end ridgeline part can be elastically deformed moderately, and unpleasant noise and abrasion can be suppressed. Further, even if a surface layer is formed on the lower surface of the blade, the leading edge line portion 62c can follow the eccentricity and minute waviness of the photosensitive member 3, and is good even when a large amount of toner is input to the cleaning blade. Cleanability can be maintained.

  In addition, by setting the elastic power within the range of 1000 [μm] from the blade bottom surface and the tip ridge line portion 62c of the blade tip surface to 60 to 90%, the tip ridge line portion can be appropriately elastically deformed.

As described above, the cleaning blade 62 of the present embodiment covers the surface with acrylic / methacrylic resin, and further, acrylic / methacrylic resin is impregnated with inclination inside the urethane rubber which is the base material of the elastic blade 622. A mixed layer is formed. Since the elastic blade 622 contains an acrylic / methacrylic resin to increase the hardness, durability over time can be secured even if the thickness of the surface layer 623 is reduced. In addition, by controlling the Martens hardness of the cleaning blade surface to 0.8 to 5.0 [N / m ² ] and the elastic work rate to 60 to 90%, the posture control of the tip ridge line portion 62c and the durability impartment are simultaneously performed. It can be expressed and high durability can be achieved. Further, it is possible to suppress the followability of the tip ridge line portion to the photoreceptor 3 due to the hard or thick surface layer 623 being formed, and to improve the cleaning performance as compared with the original elastic blade. .

  Further, as the resin impregnated in the elastic blade 622, by using a material containing an alicyclic acrylate monomer having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more, the amount of the acrylic / methacrylic resin impregnated can be suppressed. Deeply it can be impregnated with acrylic / methacrylic resin. Thereby, coexistence with the reduction | decrease of the rubber mechanical strength by swelling of base rubber and the network structure reinforcement | strengthening by the infiltration of a hard resin material can be aimed at. Further, even after the surface layer 623 is worn and the elastic blade is exposed, the impregnated layer 62d can be kept in contact with the surface of the photoreceptor over time. Thereby, it is possible to suppress the turning of the tip ridge line portion over time while suppressing the occurrence of abnormal wear and abnormal noise.

  Further, if only the surface layer 623 having a high hardness is provided on the base material of the elastic blade 622, the hardness changes suddenly at the boundary between the high hardness layer and the base material layer, stress concentrates, and the elastic blade 622 may be damaged. There is. On the other hand, in the present embodiment, the elastic blade 622 is impregnated with acrylic / methacrylic resin to increase the hardness of the surface of the elastic blade. Therefore, it is possible to suppress a sudden change in hardness at the boundary between the surface layer and the elastic blade, and to prevent the elastic blade 622 from being damaged due to stress concentration.

Next, a verification experiment conducted by the applicants will be described.
The durability test was performed by changing the material of the elastic blade 622, the material of the surface layer 623, the impregnation method, and the formation of the surface layer 623 on the blade lower surface 62b.
As the elastic blade 622, four urethane rubbers having physical properties of JIS-A hardness, 23 ° C. rebound resilience, and 300% modulus in Table 1 below were prepared.

The rebound resilience of urethane rubber is No. manufactured by Toyo Seiki Seisakusho. The measurement was performed according to JIS K6255 using a 221 regilynester. The sample was a stack of about 2 [mm] sheets so that the thickness was 4 [mm] or more.
The 300% modulus of urethane rubber was measured according to JISK6251 using a tensile tester AG-X manufactured by Shimadzu Corporation.

  Curing materials 1 to 6 shown in Table 2 below were used as the curing material used for the impregnation treatment and the surface layer 623 formation treatment. The physical properties of the acrylic monomer used for each curable material are shown in Table 3 below.

Next, the configuration of the image forming apparatus for which the verification experiment has been performed will be described.
Using any of the urethane rubbers 1 to 4, a strip-shaped elastic blade having a thickness of 1.8 [mm] is prepared, and the elastic blade is used as an impregnation material, and the curing material 4 to 6 is predetermined. After soaking for a time (for example: 120 [seconds]), air-dry for 3 minutes. Further, a surface layer 623 made of any one of the cured materials 1 to 3 was formed by a spray coating method. Specifically, for each elastic blade made of urethane rubber appropriately impregnated, a predetermined layer thickness is obtained by spray coating at a spray gun moving speed of 10 [mm / s] from the blade tip surface. In this way, overcoating was performed over the entire tip surface. After touch-drying for 3 minutes, coating was performed so that a surface layer 623 was formed on the lower surface of the blade. Thereafter, finger touch drying was further performed for 3 minutes, and ultraviolet exposure (140 [W / cm] × 5 [m / min] × 5 passes) was performed.

  The elastic blade 622 on which the surface layer was formed was fixed with an adhesive to a sheet metal holder that can be mounted on the Ricoh color composite machine imagi MP C4500 to obtain a prototype cleaning blade 62. This is also mounted on a Ricoh color composite machine, imgio MP C4500 (the printer unit has the same configuration as the printer 500 shown in FIG. 2), and image forming apparatuses of Examples 1 to 10 and Comparative Examples 1 to 5 are manufactured. did. The cleaning blade 62 was attached so that the linear pressure was 20 [g / cm] and the cleaning angle was 79 [°]. Further, the apparatus used in this experiment was provided with a lubricant application device 10 on the surface of the photoconductor 3, and the static friction coefficient of the surface of the photoconductor 3 was maintained at 0.2 or less during non-image formation by applying the lubricant. The method for measuring the coefficient of static friction on the surface of the photoreceptor 3 is the Euler belt method, and is described in paragraph No. 0046 of Japanese Patent Laid-Open No. 9-166919, for example.

In the verification experiment, a toner prepared by a polymerization method was used. The physical properties of the toner are as follows.
Toner base: circularity 0.98, average particle size 4.9 [μm]
External additive: 1.5 parts of small particle size silica (Clariant H2000)
0.5 parts small particle size titanium oxide (Taika MT-150AI)
1.0 parts of large particle size silica (UFP-30H manufactured by Denki Kagaku Kogyo)

The verification experiment was performed in a laboratory environment: 21 [° C.] · 65 [% RH], paper feeding condition: image area ratio 5% chart with 3 prints / job at 50,000 sheets (A4 landscape). And the following items were evaluated.
〔Evaluation item〕
Occurrence of cleaning failure: Existence (visual observation)
Image at the time of evaluation: Vertical belt pattern (with respect to paper traveling direction) 43 [mm] width, 3 charts
Output 20 sheets (A4 side)
Wear cross-sectional area after passing 100,000 sheets: Wear area relative to the initial stage (shaded area shown in FIG. 8)
The abrasion cross-sectional area after passing 100,000 sheets was measured with a laser microscope VK-9500 manufactured by KYENCE.

Each cleaning blade was also examined for the impregnation depth of the cured resin. The impregnation depth was measured with a transmission microscope FT-IR (Continuum infrared microscope, manufactured by Thermo Electron Co., Ltd.) by using a cryomicrotome (EM / FCS, manufactured by Leica) to produce a cross-sectional slice at the edge of the target sample. The impregnation depth was measured using an index obtained by standardizing the value obtained by dividing the peak area near 1710 cm ^{−1 by} the peak area of 1415 cm ⁻¹ with the value of the non-impregnated part.

  Further, with respect to the blade lower surface 62b and the blade tip surface 62a, 20 [μm], 200 [μm], 300 [μm], 500 [μm], 1000 [μm], 2000 [μm] from the tip ridge line portion 62c (edge), The Martens hardness and the elastic power were also examined at a position of 3000 [μm]. The Martens hardness is pushed in with a Vickers indenter of 9.8 [mN] for 30 seconds using a micro hardness tester HM-2000 manufactured by Fischer Instruments, and held for 5 seconds, with a force of 9.8 [mN]. And extracted in 30 seconds. The elastic power is obtained from the equation of Welast / Wplast × 100%, where Wplast is the accumulated stress when pushing in the Vickers indenter when measuring Martens hardness, and Welast is the accumulated stress at the test load unloading temple. It was.

  Table 4 below shows the configuration of the cleaning blade 62 of Examples 1 to 10 and Comparative Examples 1 to 5 and the results of verification experiments. Table 5 shows the results of examining the Martens hardness and the elastic power at each position on the blade lower surface 62b. Table 6 shows the results of examining the Martens hardness and the elastic power at each position of the blade tip surface 62a.

  The maximum Martens hardness value in the range of 1000 μm from the edge shown in Table 4 is the maximum value of Martens hardness in the range of 1000 μm from the tip ridge line portion on the blade tip surface 62a.

  In Comparative Example 1, neither the impregnation treatment nor the surface layer formation is performed on the elastic blade. Accordingly, as shown in FIG. 9A, the leading edge ridge line portion 62c turns over in the direction of movement of the surface of the photosensitive member, and wear out occurs in the initial to middle periods. Eventually, it is considered that the leading edge portion 62c is missing, the cleaning function cannot be obtained, and the entire surface is poorly cleaned.

  In Comparative Example 2, only the surface layer was formed without performing the impregnation treatment. Therefore, it was considered that the base urethane rubber exposed as the wear progressed generated unpleasant chatter noise and caused cleaning failure due to toner slipping. .

In Comparative Example 3, the wear cross-sectional area after the 100,000 sheet passing test was 450 μm ² , and a belt-like cleaning defect was confirmed. Comparative Example 3 has an impregnation depth of 100 μm, as in Examples 1-10. However, the peak area of the absorption peak of the acrylic resin measured with a transmission microscope FT-IR (Continuum infrared microscope, manufactured by Thermo Electron) was smaller than those of Examples 1-10. From this, it can be said that in Comparative Example 3, although the acrylic resin is impregnated to 100 μm, the impregnation amount is small. As shown in Tables 2 and 3, Comparative Example 3 is a cured resin No. 1 having an acrylic resin having a functional group equivalent of 1000 exceeding the functional group equivalent of 200. This is probably because the impregnation treatment was performed using No. 3. That is, it is considered that since the functional group equivalent 1000 of the acrylic material used for the impregnation treatment is large, the molecular weight between the cross-linking points is large and it is difficult to penetrate to a sufficient depth of the elastic blade.

Thus, in Comparative Example 3, since a sufficient amount of acrylic resin could not be impregnated to a sufficient depth of the elastic blade, a modification effect could not be obtained to a sufficient depth, and the abrasion resistance of the elastic blade was sufficient. It is thought that it could not be improved. Therefore, even if it is coated with a highly durable surface layer, the surface layer disappears due to long-term wear, and after the elastic blade is exposed, a sufficiently modified portion of the elastic blade disappears early and the elasticity It is thought that the wear rate after the blade exposure increased. As a result, the wear cross-sectional area after the 100,000 sheet passing test was as large as 450 μm ^2, and it is considered that a belt-like cleaning failure due to toner slipping occurred.

In Comparative Example 4, the abrasion cross-sectional area after the 100,000 sheet passing test was as large as 350 μm ^2, and a belt-like cleaning defect was confirmed. In Comparative Example 4, the acrylic material is infiltrated deeply into the elastic blade (impregnation depth: 300 μm) for a longer time than the immersion time (120 seconds) of the other cleaning blades in the cured material. . As a result, it is considered that the tip ridge line portion of the elastic blade is hard and too resinous, and the behavior of the tip ridge line portion 62c of the cleaning blade at the time of rubbing against the photosensitive member is excessively suppressed. Therefore, the wear of the blade progresses early, the wear cross-sectional area becomes as large as 350 μm ^2, and it is considered that a belt-like cleaning defect has occurred.

In Comparative Example 5, the wear cross-sectional area after the 100,000 sheet passing test was as large as 350 μm ^2, and a belt-like cleaning defect was confirmed. In Comparative Example 5, as shown in Table 2, the cured resin No. 3 was used to make a surface layer. Cured resin no. As shown in Table 3, 3 is a derivative of pentaerythritol triacrylate having a functional group equivalent of 198 and a functional group equivalent of 110. As a result, it is considered that the crosslinking density is insufficient, the surface layer is fragile, and the surface layer is worn early. As a result, the wear of the blade progresses early, the wear cross-sectional area becomes as large as 350 μm ^2, and it is considered that a belt-like cleaning defect has occurred.

In Comparative Example 6, the wear cross-sectional area after the 100,000 sheet passing test was as large as 600 μm ^2, and a belt-like cleaning defect was confirmed. In Comparative Example 6, No4 urethane rubber shown in Table 1 was used as the base rubber. This No. 4 urethane rubber has a high rebound resilience at 23 ° C. as 50 [%] and a low 300 [%] modulus as 11 [MPa] as a base blade. As a result, the effect of modification by impregnation with the acrylic material is not sufficient, and it is considered that the abrasion resistance of the impregnation layer of the elastic blade is insufficient. Therefore, the wear rate after the surface layer disappears and the elastic blade is exposed due to long-term wear progress is high, and the wear cross-sectional area after the 100,000 sheet passing test is as large as 600 μm ^2. .

On the other hand, in Examples 1 to 10, the wear cross-sectional area after the 100,000 sheet passing test could be suppressed to 50 [μm ² ] or less, and no cleaning failure or abnormal noise was confirmed. This is probably because the cleaning blade has the following configuration. First, as the resin material of the surface layer, sufficient durability can be obtained by using an acrylic monomer having a functional group equivalent of 110 or less and a pentaerythritol triacrylate having 3 to 6 functional groups as a main skeleton. It is possible to suppress the layer from wearing out early. In addition, a urethane rubber having a rebound resilience at 23 [° C.] of 31 [%] or less and a 300 [%] modulus of 19 [MPa] or more is used as the base rubber, and the resin material to be impregnated is functional group equivalent By using an alicyclic acrylate material having a molecular weight of 200 or less and a functional group number of 2 or more, a modification effect by impregnation with an acrylic material can be sufficiently obtained. Further, the acrylic resin can be impregnated with 100 μm or more. Thereby, even if a surface layer lose | disappears and base rubber | gum is exposed, abrasion of base rubber | gum can be suppressed. In addition, an increase in the wear rate of the base rubber can be suppressed over time without the impregnated layer disappearing early.

  In Examples 1 to 10, the cleaning blade can be provided with appropriate elasticity by suppressing the impregnation depth to 150 μm or less. As a result, as shown in FIG. 9B, the tip ridge line portion can be appropriately elastically deformed, and the progress of blade wear can be suppressed.

  As described above, in Examples 1 to 10, by appropriately setting the base rubber, the resin material to be impregnated, the impregnation depth, and the resin material of the surface layer, the tip ridge line portion is turned up and abnormal noise is generated. Will not occur. Further, the wear of the cleaning blade can be suppressed over time, and good cleaning properties can be obtained over time.

Further, in the cleaning blades of Examples 1 to 10, the surface Martens hardness in the range from the blade ridge line portion of the blade lower surface and the blade tip surface to 1000 [μm] is 0.8 to 5.0 [N / mm ^2]. The elastic power was 60 to 90 [%]. As the cleaning blade has the above-mentioned characteristics, it is considered that the tip edge line portion can be appropriately elastically deformed as shown in FIG. 9B and the progress of blade wear can be suppressed.

  Further, in Examples 1 to 10, the resin forming the surface layer contains a perfluoropolyether skeleton-containing monomer. As a result, the friction coefficient between the surface layer 623 and the photoreceptor 3 can be lowered, and wear of the surface layer can be suppressed. This is also considered to be one factor that can suppress the wear of the cleaning blade 62 over time.

  Further, the leveling blade 103c (see FIG. 3) for leveling the lubricant may have the same configuration as the cleaning blade. By making the leveling blade 103c similar in configuration to the cleaning blades of Examples 1 to 10, it is possible to suppress the turning of the edge portion of the leveling blade. Generation of sound can be suppressed. Further, the followability of the tip edge line portion 62c of the leveling blade 103c to the photoreceptor can be improved, and the lubricant can be leveled uniformly. Further, the wear resistance can be improved, and the life of the leveling blade can be increased.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
An elastic blade 622 having an impregnated layer 62d formed by impregnating at least the leading edge portion 62c with an acrylic / methacrylic resin material, and a surface layer 623 made of an acrylic / methacrylic resin material covering the leading edge portion 62c of the elastic blade 622. A blade member that makes the tip ridge line portion 62c abut against a member to be abutted such as the photoreceptor 3, and the elastic blade 622 has a rebound resilience of 31 [%] or less at 23 [° C.] and 300 [%]. The acrylic / methacrylic resin, which is a urethane rubber having a modulus of 19 [MPa] or more and that forms the impregnation layer 62d, includes an alicyclic acrylate material having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more to form the surface layer 623. The acrylic / methacrylic resin to be used has a functional group equivalent molecular weight of 110 or less and a pentaerythritol tri-functional group having 3-6 functional groups. Include a material that the acrylate as a main skeleton, and the thickness of the impregnated layer 62d and 0.99 [[mu] m] or less.
The cleaning blade described in Patent Document 1 has the effect of suppressing the occurrence of abnormal wear and abnormal noise in the 50,000-sheet endurance test and improving the followability of the tip ridge line portion to the member to be cleaned. It was a configuration that provided good cleaning properties.
On the other hand, (Aspect 1) has the following configurations 1 to 4 to suppress the occurrence of abnormal wear and abnormal noise during use over time as shown in the verification experiment described above, and to cover the tip ridge line portion. While obtaining the effect of improving the followability to the cleaning member, it was possible to improve the wear resistance. As a result, it was possible to obtain a good cleaning property even in the endurance test for 100,000 sheets, and to extend the life of the cleaning blade.
1. The elastic blade is a urethane rubber having a rebound resilience of 31 [%] or less at 23 [° C.] and a 300 [%] modulus of 19 [MPa] or more.
2. The impregnated layer includes an alicyclic acrylate material having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more, and is formed of an acrylic / methacrylic resin.
3. The surface layer is formed of an acrylic / methacrylic resin containing a material having a functional group equivalent molecular weight of 110 or less and a functional group number of 3 to 6 pentaerythritol triacrylate as a main skeleton.
4). The thickness of the impregnated layer is 150 [μm] or less.

  Moreover, you may use the blade member which has the structure of said 1-4 as the leveling blade 103c which smoothes a lubricant. Thereby, the turning of the tip ridge portion of the leveling blade 103c can be suppressed, and the followability of the tip ridge portion to the contacted member can be improved while suppressing the occurrence of abnormal wear and abnormal noise. Thereby, the lubricant applied uniformly to the surface of the photoreceptor 3 can be leveled. Further, the wear resistance of the leveling blade can be improved, the lubricant can be satisfactorily leveled over time, and the life of the leveling blade 103c can be increased.

(Aspect 2)
In (Aspect 1), the surface Martens hardness at least in the range from the tip ridge line portion 62c to 1000 [μm] is 0.8 [N / mm ² ] to 5.0 [N / mm ² ] and elastic The work rate was set to 60% or more and 90% or less [%].
According to (Aspect 2), as shown in the verification experiment, the surface Martens hardness in the range from the tip ridge line portion 62c to 1000 [μm] is 0.8 [N / mm ² ] or more and 5.0 [N / Mm ² ] or less and the elastic power is 60% or more and 90 or less [%], the tip ridge line portion 62c can be provided with appropriate elasticity. Thereby, the progress of blade wear can be suppressed, and the followability to the photoreceptor 3 can be improved.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the acrylic / methacrylic resin forming the surface layer 623 includes a perfluoropolyether skeleton-containing monomer.
According to (Aspect 3), the slidability of the surface layer 623 can be improved, and the turning of the tip ridge line portion can be suppressed. Further, the progress of wear of the surface layer 623 can be suppressed, and the wear resistance of the blade member can be improved.

(Aspect 4)
In (Aspect 1) to (Aspect 3), the thickness of the impregnation layer 62d is set to 100 [μm] or more.
According to (Aspect 4), the impregnated layer 62d can be brought into contact with a member to be contacted such as the photosensitive member 3 over time even if the wear of the blade member progresses. Thereby, progress of abrasion of an elastic blade can be suppressed over time, and lifetime improvement of a blade member can be achieved.

(Aspect 5)
The blade member according to any one of (Aspect 1) to (Aspect 4), wherein unnecessary deposits on the contacted member are removed.
According to (Aspect 5), as shown in the verification experiment, good cleaning properties can be maintained over time.

(Aspect 6)
In an image forming apparatus that finally transfers an image formed on an image carrier such as a photoreceptor 3 moving on the surface to a recording medium such as transfer paper P, the image contacted with the surface of the image carrier and adhered to the surface The blade member of (Aspect 5) is used as a cleaning member for removing unnecessary deposits.
With such a configuration, good cleaning properties can be maintained over time, and good images can be obtained. Moreover, generation | occurrence | production of unusual noise can be suppressed.

(Aspect 7)
In (Aspect 6), a lubricant application unit such as a lubricant application device 10 for applying a lubricant to an image carrier such as the photoreceptor 3 is provided.
With such a configuration, the surface of the photoreceptor can be protected with a lubricant, and the life of the photoreceptor can be extended. Further, the friction coefficient between the photosensitive member 3 and the cleaning blade 62 can be reduced, wear of the cleaning blade can be suppressed, and the life of the cleaning blade can be increased.

(Aspect 8)
Cleaning means such as a cleaning device 6 having an image carrier such as the photoreceptor 3 and a cleaning member for removing unnecessary deposits attached on the surface of the image carrier, and a lubricant for applying a lubricant to the surface of the image carrier In a process cartridge such as the image forming unit 1 that integrally supports a lubricant application unit such as the application apparatus 10 and is detachably attached to the main body of the image forming apparatus, the blade member of (Aspect 5) is used as a cleaning member. .
According to this, as described in the above embodiment, it is possible to obtain a process cartridge capable of obtaining a good cleaning property over time.

DESCRIPTION OF SYMBOLS 1 Image forming unit 3 Photoconductor 4 Charging roller 5 Developing device 6 Cleaning device 7 Primary transfer roller 10 Lubricant coating device 14 Intermediate transfer belt 60 Transfer unit 62 Cleaning blade 62a Blade tip surface 62b Blade lower surface 62c Tip ridge (contact portion) )
62d impregnation layer 103c leveling blade 500 image forming apparatus 622 elastic blade 623 surface layer

JP 2012-83729 A

Claims (8)

An elastic blade having an impregnation layer formed by impregnating an acrylic / methacrylic resin material at least at the tip ridge line portion;
A surface layer made of an acrylic / methacrylic resin material that covers a tip ridge line portion of the elastic blade, and a blade member that abuts the tip ridge line portion against a contacted member,
The elastic blade is urethane rubber having a rebound resilience at 23 [° C.] of 31 [%] or less and a 300 [%] modulus of 19 [MPa] or more,
The acrylic / methacrylic resin forming the impregnation layer includes an alicyclic acrylate material having a functional group equivalent molecular weight of 200 or less and a functional group number of 2 or more,
The acrylic / methacrylic resin forming the surface layer includes a material having a main skeleton of pentaerythritol triacrylate having a functional group equivalent molecular weight of 110 or less and a functional group number of 3 to 6,
A blade member, wherein the impregnated layer has a thickness of 150 [μm] or less. The blade member according to claim 1,
The Martens hardness of the surface in the range of at least 1000 [μm] from the tip ridge is at least 0.8 [N / mm ² ] and at most 5.0 [N / mm ² ], and the elastic power is 60 [ %] To 90% or less [%]. The blade member according to claim 1 or 2,
A cleaning blade, wherein the acrylic / methacrylic resin forming the surface layer contains a perfluoropolyether skeleton-containing monomer. The blade member according to any one of claims 1 to 3,
A blade member, wherein the impregnation layer has a thickness of 100 [μm] or more. The blade member according to any one of claims 1 to 4,
A blade member characterized by removing unnecessary deposits on a contacted member. In an image forming apparatus that finally transfers an image formed on an image carrier that moves on a surface to a recording medium,
An image forming apparatus using the blade member according to claim 5 as a cleaning member for contacting the surface of the image carrier and removing unnecessary deposits adhered on the surface. 7. The image forming apparatus according to claim 6, further comprising a lubricant application unit that applies a lubricant to the image carrier. An image carrier;
Cleaning means having a cleaning member for removing unnecessary deposits adhered on the surface of the image carrier;
In a process cartridge configured to integrally support a lubricant application unit that applies a lubricant to the surface of the image carrier and to be detachable from the main body of the image forming apparatus,
A process cartridge using the blade member according to claim 5 as the cleaning member.

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