JP2007140391A - Lubricant applicator, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smooth more uniformly a lubricant applied on the surface of an image bearing member so as to prevent formation of an abnormal image in an image forming apparatus in which the surface of the image bearing member after transferring a toner image is cleaned with a cleaning blade held by a blade holder, a lubricant is applied on the surface of the image bearing member after cleaned, and the applied lubricant is smoothed over the surface of the image bearing member by a smoothing blade. <P>SOLUTION: The smoothing blade 32 is specified to have a JIS-A(K6301) hardness of 79 degrees or higher, a contact angle θ of 10° or more with respect to the surface of the image bearing member 2Y and a contact line pressure of 0.01 N/cm or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lubricant application device for applying a lubricant to the surface of an image carrier, a process cartridge having the lubricant application device, and an image forming apparatus having the lubricant application device.

  2. Description of the Related Art Conventionally, an image forming apparatus that forms a toner image on an image carrier and cleans the surface of the image carrier after transferring the toner image with a cleaning device is well known. The image carrier is composed of a photoreceptor or an intermediate transfer body to which a toner image is transferred from the photoreceptor. Image formation provided with a lubricant application device for applying a lubricant to the surface of the image carrier, leveling the lubricant on the image carrier with a leveling blade, and forming a lubricant layer on the surface of the image carrier An apparatus is also conventionally known (see Patent Document 1). According to such an image forming apparatus, the surface of the image carrier after the toner image is transferred can be reduced even when a toner having a reduced spherical friction and a reduced particle size is used. Cleaning can be efficiently performed by the cleaning member, and a high-quality image can be formed.

  However, according to a study by the present inventors, a lubricant that is uniform on the surface of the image carrier can be obtained simply by applying a lubricant to the surface of the image carrier and leveling the applied lubricant with a leveling blade. It is difficult to form a layer, and the coefficient of friction on the surface of the image carrier becomes non-uniform, so that the toner in the image area called “image blur” or the so-called “image blur” in the image area There is a risk that an abnormal image such as insufficient adhesion or a so-called “buzzing” image may occur.

JP 2001-305907 A

  An object of the present invention is to apply a lubricant more uniformly on the surface of an image carrier to suppress the occurrence of abnormal images, a process cartridge having the lubricant application device, and the lubrication An object of the present invention is to provide an image forming apparatus provided with an agent coating device.

  In order to achieve the above object, the present invention is a lubricant application device for applying a lubricant to the surface of an image carrier, and a solid lubricant and an application that rotates while contacting the solid lubricant and the surface of the image carrier. In a lubricant application device having a roller and a leveling blade for leveling the lubricant on the image carrier applied by the application roller, the leveling blade has a JIS-A (K6301) hardness of 79 degrees. A lubricant coating apparatus characterized by the above is proposed (claim 1).

  In the lubricant application device according to claim 1, it is advantageous that the leveling blade is disposed in a trailing direction with respect to the moving direction of the image carrier surface (claim 2).

  Furthermore, in the lubricant application device according to claim 1 or 2, the contact angle of the leveling blade to the surface of the image carrier is 10 ° or more, and the contact linear pressure is 0.01 N / cm or more. (Claim 3).

  In order to achieve the above object, the present invention also provides an image carrier, a charging device that charges the image carrier, and a development that visualizes the electrostatic latent image formed on the image carrier as a toner image. 4. A process cartridge comprising: an apparatus; at least one of cleaning apparatuses for cleaning a surface of an image carrier after transfer of a toner image; and a lubricant applying apparatus according to claim 1. Item 4).

  Further, in the process cartridge according to claim 4, it is advantageous that the cleaning device is configured to clean the surface of the image carrier before the lubricant is applied by the lubricant application device ( Claim 5).

  In order to achieve the above object, the present invention provides an image carrier, a charging device that charges the image carrier, and an optical writing device that forms an electrostatic latent image by exposing the surface of the image carrier after charging. And a developing device that visualizes the electrostatic latent image as a toner image, a cleaning device that cleans the surface of the image carrier after the toner image is transferred, and the lubricant according to claim 1. An image forming apparatus including a coating apparatus is proposed.

  Further, in the image forming apparatus according to claim 6, it is advantageous that the cleaning device cleans the surface of the image carrier before the lubricant is applied by the lubricant applying device (claim 7).

  In the image forming apparatus according to claim 6 or 7, it is advantageous to use a toner having an average circularity in the range of 0.93 to 1.00 (claim 8).

  Further, in the image forming apparatus according to claim 6 or 7, it is advantageous to use a toner having a shape factor SF-1 of 100 to 180 and a shape factor SF-2 of 100 to 180 ( Claim 9).

  According to the present invention, the lubricant can be applied more uniformly to the surface of the image carrier than before, and the occurrence of abnormal images can be more effectively suppressed.

  FIG. 1 is a vertical sectional view showing an example of an image forming apparatus capable of forming a full color image. The image forming apparatus shown here is an endless intermediate transfer belt 3 that is wound around a plurality of support rollers 4, 5, 6 and rotated in the direction of arrow A, and is disposed opposite to the intermediate transfer belt 3. The first to fourth process cartridges 7Y, 7C, 7M, and 7BK are provided. Each of the process cartridges 7Y to 7BK has an image carrier 2Y, 2C, 2M, 2BK configured as a drum-shaped photoconductor on which toner images of different colors are formed, and differently on each of the image carriers. Each color toner image is formed and transferred onto the intermediate transfer belt 3 in a superimposed manner. A drum-shaped intermediate transfer member can be used instead of the intermediate transfer member formed of the intermediate transfer belt 3. Reference numeral 1 in FIG. 1 denotes the image forming apparatus main body.

  The configuration in which a toner image is formed on each of the image carriers 2Y to 2BK of the first to fourth process cartridges 7Y to 7BK and the toner image is transferred to the intermediate transfer belt 3 is different only in the color of the toner image. Since all are substantially the same, only the configuration in which a toner image is formed on the image carrier 2Y of the first process cartridge 7Y and this is transferred to the intermediate transfer belt 3 will be described.

  FIG. 2 is an enlarged cross-sectional view of the first process cartridge 7Y. The image carrier 2Y of the process cartridge 7Y shown here is rotatably supported by the unit case 8 and is driven to rotate clockwise by a driving device (not shown). At this time, a charging voltage is applied to a charging device composed of a charging roller 9 rotatably supported by the unit case 8, whereby the surface of the image carrier 2Y is charged to a predetermined polarity. The charged image carrier 2Y is irradiated with light-modulated laser light L emitted from the optical writing device 10 shown in FIG. 1 which is separate from the process cartridge 7Y, whereby the image carrier 2Y is electrostatically charged. A latent image is formed. The optical writing device 10 exposes the charged image carrier surface to form an electrostatic latent image. This electrostatic latent image is visualized as a yellow toner image by the developing device 11.

  The developing device 11 has a developing case 12 constituted by a part of the unit case 8, and the developing case 12 contains a two-component dry developer D having toner and a carrier. The developing case 12 is provided with two screws 13 and 14 for stirring the developer D and a developing roller 23 that is driven to rotate counterclockwise in FIG. The developer pumped up by the toner is carried on the peripheral surface of the developing roller 23, conveyed in the rotation direction of the developing roller 23, and the developer passing through the doctor blade 24 is between the developing roller 23 and the image carrier 2Y. To the development area. At this time, the toner in the developer is electrostatically transferred to the electrostatic latent image formed on the image carrier 2Y, and the latent image is visualized as a toner image. The developer that has passed through the developing region is separated from the developing roller 23 and stirred by the screws 13 and 14. In this way, a toner image is formed on the image carrier 2Y. A developing device using a one-component developer having no carrier can also be employed.

  On the other hand, a primary transfer roller 25 is disposed on the opposite side of the process cartridge 7Y with the intermediate transfer belt 3 interposed therebetween. By applying a transfer voltage to the primary transfer roller 25, the toner image on the image carrier 2Y is changed. Primary transfer is performed on the intermediate transfer belt 3 that is rotationally driven in the direction of arrow A. The transfer residual toner adhering to the image carrier 2Y after the toner image transfer is removed by the cleaning device 26. The cleaning device 26 of this example includes a cleaning case 27 constituted by a part of the unit case 8, a cleaning blade 28 whose tip edge is pressed against the surface of the image carrier 2 Y, and a blade holder that holds the cleaning blade 28. 29 and a toner conveying screw 30 disposed in the cleaning case 27. The blade holder 29 is fixed to the cleaning case 27, and the cleaning blade 28 is arranged in the counter direction with respect to the surface movement direction of the image carrier 2Y. The cleaning blade 28 is an example of a cleaning member, and is configured by an elastic body such as urethane rubber, silicon rubber, or other rubber, and the base end side of the cleaning blade 28 is a blade holder made of, for example, an adhesive. 29 is fixed. When the leading edge portion of the cleaning blade 28 comes into pressure contact with the surface of the image carrier 2Y, the transfer residual toner on the image carrier 2Y is scraped off and removed. The removed toner is transported out of the cleaning case by a toner transport screw 30 that is driven to rotate. In this way, the cleaning device 26 serves to clean the surface of the image carrier after the toner image is transferred. Instead of the cleaning blade 28, it is also possible to use a cleaning member made of a conductive brush of medium resistance or low resistance to which a bias is applied.

  The process cartridge 7Y is provided with a lubricant application device 31 for applying a lubricant to the surface of the image carrier 2Y, which will be described in detail later.

  In the same manner as described above, a cyan toner image, a magenta toner image, and a black toner image are formed on the second to fourth image carriers 2C, 2M, and 2BK shown in FIG. Are sequentially superposed on the intermediate transfer belt 3 to which the yellow toner image has been transferred, and are primarily transferred to form a composite toner image on the intermediate transfer belt 3. The transfer residual toner on each of the image carriers 2C, 2M, 2BK after the toner image transfer is removed by the cleaning device is the same as in the case of the first image carrier 2Y.

  On the other hand, as shown in FIG. 1, a paper feed cassette 21 containing a recording medium P made of, for example, transfer paper, and a paper feed device 16 having a paper feed roller 15 are disposed in the lower part of the image forming apparatus main body 1. The uppermost recording medium P is sent out in the arrow B direction by the rotation of the paper feed roller 15. The fed recording medium is fed by the registration roller pair 17 between the portion of the intermediate transfer belt 3 wound around the support roller 4 at a predetermined timing and the secondary transfer roller 18 disposed on the intermediate transfer belt 3. The At this time, a predetermined transfer voltage is applied to the secondary transfer roller 18, whereby the composite toner image on the intermediate transfer belt 3 is secondarily transferred to the recording medium P.

  The recording medium P onto which the composite toner image has been secondarily transferred is further conveyed upward and passes through the fixing device 19, and at this time, the toner image on the recording medium P is fixed by the action of heat and pressure. The recording medium P that has passed through the fixing device 19 is discharged to the paper discharge unit 22 at the top of the image forming apparatus main body 1. Further, the transfer residual toner adhering to the intermediate transfer belt 3 after the toner image transfer is removed by the cleaning device 20.

  Here, the cleaning blade 28 shown in FIG. 2 and the image carrier 2Y are prevented from being worn, and even when spherical toner having a small particle diameter is used, the cleaning blade 28 maintains high cleaning performance. The image forming apparatus of the example is provided with the aforementioned lubricant application device 31. The lubricant application device 31 is also provided in the second to fourth process cartridges 7C, 7M, and 7BK. However, since the configuration and operation are all the same, the process cartridge 7Y shown in FIG. Only the lubricant application device 31 will be described.

  The lubricant application device 31 shown in FIG. 2 includes an application roller configured as a brush roller 33 that contacts the surface of the image carrier 2 </ b> Y, a solid lubricant 34 that is disposed on the brush roller 33, and the solid lubricant. And a guide 36 that guides the solid lubricant 34 through the lubricant holder 35, and a compression coil spring 37 that is an example of a pressure member. The brush roller 33 has a core shaft 38 and a large number of brush fibers 39 whose base ends are fixed to the core shaft 38. The brush roller 33 is substantially parallel to the image carrier 2Y. Extending along the image carrier 2Y, the longitudinal ends of the core shaft 38 of the brush roller 33 are rotatably supported with respect to the unit case 8 via bearings (not shown). During the image forming operation, the brush roller 33 is driven to rotate counterclockwise in FIG. The brush roller 33 can also be driven to rotate clockwise. The solid lubricant 34 is obtained by, for example, dissolving a lubricating oil additive mainly composed of zinc stearate and then cooling and solidifying the solid lubricant 34. The solid lubricant 34 has a bar shape or a rectangular parallelepiped shape extending long in parallel with the brush roller 33. The tip end surface of the brush roller 33 that is formed is in contact with the brush fiber 39 of the brush roller 33, and the base end side surface opposite to this is fixed to the lubricant holder 35. The guide 36 has a pair of guide plates 40 and 41 arranged to face each other in parallel with each other, and these guide plates 40 and 41 are integrated by a connecting plate 42. The pair of guide plates 40 and 41 and the connecting plate 42 are constituted by a part of the unit case 8.

  The lubricant holder 35 is disposed between the pair of guide plates 40 and 41, and the lubricant holder 35 is slidably brought into contact with the mutually opposing surfaces of the guide plates 40 and 41. As shown in FIG. 3, a plurality of compression coil springs 37 are arranged between the connecting plate 42 and the lubricant holder 35, and these compression coil springs 37 are connected to the solid lubricant via the lubricant holder 35. 34 is pressed against the brush roller 33. Instead of the compression coil spring, a pressurizing member made of a torsion coil spring or a leaf spring can be used.

  As described above, the solid lubricant 34 comes into pressure contact with the brush fibers 39 of the brush roller 33, and the brush fibers 39 abut against the surface of the image carrier 2Y. At this time, the brush roller 33 rotates. The lubricant of the agent 34 is scraped off by the brush fibers 39, and the scraped powdery lubricant is applied to the surface of the image carrier 2Y. As described above, the brush roller 33 constitutes an example of an application roller that applies the powdery lubricant scraped from the solid lubricant 34 to the surface of the image carrier. Instead of the brush roller, an application roller having a foam fixed around the core shaft can be used.

  The solid lubricant 34 is scraped off and consumed by the brush roller 33, and its thickness decreases with time. However, since the solid lubricant 34 is pressurized by the compression coil spring 37, the solid lubricant 34 is always brushed. It can abut against the brush fiber 39 of the roller 33.

  As the solid lubricant 34, it is possible to use a dry solid hydrophobic lubricant. In addition to zinc stearate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, Those having a stearic acid group such as copper stearate, strontium stearate, calcium stearate, cadmium stearate and magnesium stearate can be used. Also, the same fatty acid groups such as zinc oleate, manganese oleate, iron oleate, cobalt oleate, lead oleate, magnesium oleate, copper oleate, palmitic acid, zinc cobalt palmitate, copper palmitate, palmitic acid Magnesium, aluminum palmitate, or calcium palmitate may be used. In addition, fatty acids such as lead caprylate, lead caproate, zinc linolenate, cobalt linolenate, calcium linolenate and cadmium ricolinolenate, metal salts of fatty acids, and the like can also be used. Further, waxes such as candelilla wax, carnauba wax, rice wax, wax, ooba oil, beeswax, and lanolin can be used.

  As shown in FIG. 3, a plurality of compression coil springs 37 are provided to pressurize the lubricant holder 35 that fixedly supports the solid lubricant 34, but FIG. 3 shows the longitudinal end side of the solid lubricant 34. The compression coil spring 37 located at the center is designated by reference numeral 37A, and the compression coil spring located at the center side is designated by reference numeral 37B. At that time, the spring force of each spring is set so that the pressing force of the compression coil spring 37B positioned on the center side is smaller than the pressing force of the compression coil spring 37A positioned on the end side. The same applies to the case where a leaf spring or the like is used as the pressure member. The reason why the spring pressure is changed is based on the following reason.

  First, only by providing one compression coil spring 37, the lubricant cannot be uniformly applied to the image carrier 2Y over the longitudinal direction of the solid lubricant. For this reason, a plurality of compression coil springs 37 are used. At this time, if the compression forces of all the compression coil springs 37A and 37B are the same, the compression coil springs 37A positioned on the end side are applied. Since the pressure easily escapes to the outside, the solid lubricant 34 receives a larger pressure in the central region in the longitudinal direction, and uneven application of the lubricant to the image carrier 2Y occurs. For this reason, the applied pressure of the compression coil spring 37B located on the center side is made smaller than the applied pressure of the compression coil spring 37A located on the end side, so that the solid lubricant 34 extends over the entire longitudinal direction. The lubricant is brought into contact with the brush roller 33 with a uniform pressure so that the lubricant can be uniformly applied to the surface of the image carrier 2Y.

  In the example shown in FIG. 3, four pressure members made of the compression coil spring 37 are provided, but the number of pressure members is preferably two or more, preferably three or more. In the case where there are two pressure members, for example, the pressure member is provided on each end in the longitudinal direction of the solid lubricant. However, in this case, there is no pressure member located in the central region. The pressure balance cannot be achieved over the longitudinal direction of the solid lubricant, and uneven application of the lubricant to the image carrier 2Y occurs. Accordingly, it is possible to provide three or more pressure members arranged in the longitudinal direction of the solid lubricant so as to balance the pressure over the entire length of the solid lubricant so that the lubricant can be uniformly applied to the image carrier 2Y. preferable.

  As described above, the lubricant application device 3 of this example includes the solid lubricant 34 and the application roller including the brush roller 33 that rotates while contacting the solid lubricant 34 and the surface of the image carrier 2Y. The brush roller 33 scrapes off the powdery lubricant from the solid lubricant 34 and applies the powdery lubricant to the surface of the image carrier 2Y.

  Further, the lubricant application device 31 shown in FIG. 2 has a leveling blade 32 arranged on the downstream side of the image carrier surface movement direction with respect to the brush roller 33. The leveling blade 32 is made of rubber or the like. The tip edge portion of the elastic member is in contact with the surface of the image carrier 2Y, and the base end side is fixed to the holder 45. The leveling blade 32 is arranged in the trailing direction with respect to the moving direction of the image carrier surface, and the holder 45 is fixed to the unit case 8. On the other hand, as is apparent from FIG. 2, the brush roller 33 described above is disposed downstream of the cleaning blade 28 in the image carrier surface movement direction. The cleaning device 26 is configured to clean the surface of the image carrier before the lubricant is applied by the lubricant applying device 31.

  According to the configuration described above, the transfer residual toner adhering to the surface of the image carrier after the toner image is transferred is removed by the cleaning blade 28, and the surface of the image carrier 2 </ b> Y that has become clean by the cleaning roller 28 is thereby applied by the brush roller 33. Lubricant is applied. Next, when the lubricant on the applied image carrier 2Y passes through the leveling blade 32 in contact with the surface of the image carrier, the lubricant is uniformly spread and leveled on the surface of the image carrier 2Y. A lubricant layer is formed on the carrier.

  As described above, since the lubricant is applied to the surface of the image carrier 2Y, the friction coefficient of the surface of the image carrier after the application is lowered, thereby suppressing the wear of the image carrier itself and the cleaning blade 28. it can. Moreover, the surface of the image carrier after the toner image transfer can be efficiently cleaned by the cleaning blade 28 even when the toner having a spherical shape and a reduced particle size is used. Furthermore, since the lubricant is applied after the image carrier 2Y is cleaned and the lubricant is leveled, it is possible to prevent a deviation in the amount of lubricant applied to the surface of the image carrier and a deviation in the friction coefficient of the surface. The image quality of the image formed on the recording medium can be improved. In addition, since the leveling blade 32 is arranged in the trailing direction with respect to the moving direction of the image carrier surface, the entire structure of the lubricant application device 31 can be made compact.

  However, when the lubricant is simply applied to the image carrier 2Y as described above and the lubricant is only leveled, the lubricant applied on the image carrier 2Y is distributed to the lubricant layer having a uniform thickness. As a result, there is a risk that abnormal images such as insect erosion, image blur, and blurring may occur in the image formed on the recording medium.

  Therefore, in the lubricant application device 31 of this example, the hardness of the leveling blade 32 is set to 79 degrees or more in JIS-A (K6301) hardness in addition to the above-described components. With this configuration, as schematically shown in FIG. 4, the powdery lubricant 50 applied on the image carrier 2Y is evenly smoothed by the leveling blade 32, and the thickness is uniform on the image carrier. The lubricant layer 51 can be formed, and the overall friction coefficient thereof can be made uniform. Thereby, it is possible to effectively prevent the occurrence of insect biting, image blur, and blur in the image formed on the recording medium, and to effectively suppress the occurrence of an abnormal image. In addition, since the coefficient of friction on the surface of the image carrier is uniform, even when the cleaning blade 28 is used as a cleaning member for cleaning the surface, it is possible to prevent a problem that the cleaning blade 28 is caught.

  Further, in the lubricant application device of this example, as shown in FIGS. 2 and 4, the contact angle θ of the leveling blade 32 that contacts the surface of the image carrier 2Y in the trailing direction with respect to the surface of the image carrier. Is 10 ° or more, and the contact linear pressure is set to 0.01 N / cm or more. As a result, the thickness of the lubricant layer 51 on the image carrier leveled by the leveling blade 32 can be made more uniform, and the occurrence of abnormal images can be more effectively suppressed.

  In the image forming apparatus shown in FIG. 2, as the process cartridge 7Y in which the image carrier 2Y, the charging device, the developing device 11, the cleaning device 26, and the lubricant applying device 31 are integrally assembled. Although configured, the components of the process cartridge 7Y can be appropriately selected. In short, an image carrier, a charging device that charges the image carrier, a developing device that visualizes an electrostatic latent image formed on the image carrier as a toner image, and an image carrier after transferring the toner image What is necessary is just to comprise a process cartridge by integrally assembling at least one of the cleaning devices for cleaning the body surface and the lubricant application device.

  Further, the lubricant application device according to the present invention may be a device for applying a lubricant to the surface of an image carrier made of an intermediate transfer member to which a toner image is transferred from the photoconductor, not an image carrier made of a photoconductor. Can be configured. FIG. 5 is a schematic view showing a lubricant applying device 131 for applying a lubricant to the surface of the image carrier made of the intermediate transfer belt 3 and a cleaning device 20 for cleaning the intermediate transfer belt 3. The cleaning device 20 shown here has a cleaning blade 128 that presses against the surface of the intermediate transfer belt 3 in a counter-oriented posture with respect to the moving direction of the intermediate transfer belt 3. The lubricant application device 131 includes an application roller composed of a brush roller 133 that is in pressure contact with the surface of the intermediate transfer belt 3 at a position downstream of the cleaning blade 128 in the movement direction of the intermediate transfer belt, and a solid roller that is in contact with the brush roller 133 A lubricant 134 and a leveling blade 132 disposed downstream of the brush roller 133 in the intermediate transfer belt movement direction are provided. The leveling blade 132 is also a tray with respect to the movement direction of the intermediate transfer belt 3. It is in pressure contact with the surface of the intermediate transfer belt 3 in a ring orientation. The leveling blade 132 has a JIS-A (K6301) hardness of 79 degrees or more, and the angle θ1 at which the leveling blade 132 abuts against the surface of the image carrier made of the intermediate transfer belt 3 is 10 °. The contact linear pressure is 0.01 N / cm or more. With this configuration, a uniform lubricant layer can be formed on the surface of the intermediate transfer belt 3 to uniformly reduce the friction coefficient of the surface, thereby preventing the cleaning blade 128 from being caught and abnormal images from being generated. can do.

Next, a more specific example of the lubricant application device will be described.
[Example 1]
The cleaning blade 28 uses a urethane rubber sheet having a thickness of 1.8 mm manufactured by Toyo Tire & Rubber Co., Ltd., and has a contact pressure of 55 ± 10 (g / cm) and a contact angle of 70 ± with respect to the image carrier. The brush roller 33 is a conductive polyester brush with a bristle length of 2.5 mm (manufactured by Ashiya Co., Ltd.), and the amount of biting into the image carrier is 0.5 mm. A urethane rubber sheet made by Toyo Tire & Rubber Co., Ltd. and having a thickness of 1.3 mm is used for the leveling blade 32. The contact angle is 15 ± 5 (°) and the contact linear pressure is 0.02 ±. Process cartridges were prepared by changing the JIS-A (K6301) hardness of the leveling blade 32 to 0.01 (N / cm). These process cartridges were put into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and under a laboratory environment, 1000 sheets of continuous paper were passed under the condition of A4 size white paper horizontal paper, and the surface state of the image carrier was confirmed. As a result, as shown in Table 1 below, when the hardness is 79 degrees or more, the lubricant is uniformly applied to the surface of the image carrier, and when the hardness is 72 degrees or less, the lubricant is adhered to the surface of the image carrier. It was cloudy.

[Example 2]
The leveling blade 32 is a urethane rubber sheet having a thickness of 2 mm manufactured by Bando Chemical Co., Ltd. When the image carrier is set, the contact pressure is 25 ± 10 (g / cm), and the contact angle is 0 to 0. Installed in a trailing posture so that it can be changed to 90 (°), and a conductive nylon brush made by Toei Sangyo Co., Ltd. with a hair length of 3 mm is used for the brush roller 33. The lubricant application device 31 was prepared by setting the bite amount to 1 mm. Using this lubricant application device, the image carrier was spun until sufficient lubricant was applied (approximately 5 to 10 minutes), and a process cartridge was produced using the image carrier. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and 1000 sheets of continuous paper were passed under the conditions of 35 ° C. and 80% environment and A4 size white paper horizontal paper. As a result, as shown in Table 2 below, when the contact angle was less than 10 °, the cleaning blade was caught and the others were not generated.

[Example 3]
For the leveling blade 32, a urethane rubber sheet having a thickness of 1.6 mm manufactured by Hokushin Kogyo Co., Ltd. is used. When the image carrier is set, the contact pressure is 55 ± 10 (g / cm), and the contact angle is It is installed in a trailing posture so that it can be changed from 0 to 90 (°), and a conductive nylon brush with a bristle length of 2.5 mm (manufactured by Ashiya Co., Ltd.) is used as the brush roller 33. Was installed so that the amount of biting was 0.5 mm, and a lubricant application device 31 was prepared. Using this lubricant application device 31, the image carrier was spun until sufficient lubricant was applied (approximately 5 to 10 minutes), and a process cartridge was prepared using the image carrier. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and 1000 sheets of continuous paper were passed under the conditions of 35 ° C. and 80% environment and A4 size white paper horizontal paper. As a result, as shown in Table 3 below, when the contact angle was less than 10 °, the cleaning blade was caught, and the others were not generated.

[Example 4]
The leveling blade 32 is a urethane rubber sheet having a thickness of 1.5 mm manufactured by Toyo Tire & Rubber Co., Ltd. When the image carrier is set, the contact pressure is 20 ± 10 (g / cm), the contact angle Is installed in a trailing posture so that it can be changed from 0 to 90 (°). A conductive nylon brush made by Ashiya Co., Ltd. with a hair length of 3 mm is used as the brush roller 33, and the image carrier is used as the image carrier. On the other hand, it installed so that the amount of bite might be 1 mm, and the lubricant application device 31 was created. Using this lubricant application device 31, the image carrier was spun until sufficient lubricant was applied (approximately 5 to 10 minutes), and a process cartridge was prepared using the image carrier. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and 1000 sheets of continuous paper were passed under the conditions of 35 ° C. and 80% environment and A4 size white paper horizontal paper. As a result, as shown in Table 4 below, when the contact angle was less than 10 °, the cleaning blade was caught, and the others were not generated.

[Example 5]
The cleaning blade 28 uses a 2 mm thick urethane rubber sheet manufactured by Bando Chemical Co., Ltd., and has a contact pressure of 20 ± 10 (g / cm) and a contact angle of 75 ± 10 (°) with respect to the image carrier. The brush roller 33 is made of Toei Sangyo Co., Ltd.'s conductive nylon brush with a hair leg length of 3 mm, and is installed so that the amount of biting into the image carrier is 1 mm. As the blade 32, a urethane rubber sheet having a thickness of 1.5 mm manufactured by Toyo Tire & Rubber Co., Ltd. was used, and the contact angle was 15 ± 5 (°) and the contact linear pressure was variously changed to produce a process cartridge. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and under a laboratory environment, 1000 sheets of A4 size white paper were passed continuously under the conditions of A4 size white paper, and the presence or absence of in-machine contamination was confirmed. As a result, as shown in Table 5 below, in-machine contamination was confirmed when the abutting linear pressure was less than 0.01 (N / cm), and there were no other problems.

[Example 6]
The cleaning blade 28 uses a urethane rubber sheet having a thickness of 2 mm manufactured by Hokushin Kogyo Co., Ltd., and has a contact pressure of 25 ± 10 (g / cm) and a contact angle of 70 ± 10 (° with respect to the image carrier. The brush roller 33 is an insulating polyester brush made by Ashiya Co., Ltd. and has a hair foot length of 3 mm. The brush roller 33 is installed so that the amount of biting into the image carrier is 1 mm. A process cartridge was prepared by using a urethane rubber sheet having a thickness of 1 mm manufactured by Toyo Tire & Rubber Co., Ltd., and varying the contact angle 25 ± 5 (°) and the contact linear pressure. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and under a laboratory environment, 1000 sheets of A4 size white paper were passed continuously under the conditions of A4 size white paper, and the presence or absence of in-machine contamination was confirmed. As a result, as shown in Table 6 below, in-machine contamination was confirmed when the contact line pressure was smaller than 0.01 (N / cm), and the others were satisfactory.

[Example 7]
The cleaning blade 28 uses a urethane rubber sheet having a thickness of 1.6 mm manufactured by Toyo Tire & Rubber Co., Ltd., and has a contact pressure of 55 ± 10 (g / cm) and a contact angle of 70 ± with respect to the image carrier. The brush roller 33 is an insulating polyester brush manufactured by Ashiya Co., Ltd. and has a hair foot length of 2.5 mm so that the amount of biting into the image carrier is 0.5 mm. Installed and leveling blade 32 uses a urethane rubber sheet manufactured by Bando Chemical Co., Ltd. with a thickness of 1.3 mm. The contact angle is 22 ± 5 (°) and the contact linear pressure is variously changed. It was created. These process cartridges were loaded into Imagio NeoC325 manufactured by Ricoh Co., Ltd., and under a laboratory environment, 1000 sheets of A4 size white paper were passed continuously under the conditions of A4 size white paper, and the presence or absence of in-machine contamination was confirmed. As a result, as shown in Table 7 below, in-machine contamination was confirmed when the contact line pressure was less than 0.01 (N / cm), and the others were not problematic.

Unlike the case where the cleaning blade 28 is disposed upstream of the brush roller 33 in the image carrier surface movement direction as shown in FIG. 2, unlike FIG. 2, the image carrier surface movement direction downstream of the brush roller 33. A comparative example in which the cleaning blade 28 is disposed on the surface.
(1) The cleaning blade 28 is arranged in a counter manner upstream of the brush roller 33 (blade type: urethane blade, thickness: 1.3 mm).
Lubricant application device 31 (brush type: insulating PET, lubricant pressurization 1250 mN × 4)
The leveling blade 32 is disposed downstream of the brush roller 33 by a trailing method (blade type: urethane blade, thickness: 1.3 mm).
(2) No cleaning blade upstream of the brush roller 33.
Lubricant application device 31 (brush type: insulating PET, lubricant pressurization 1250 mN × 4)
The leveling blade 32 is arranged in a counter manner downstream of the brush roller 33 (blade type: urethane blade, thickness: 1.3 mm).
Apply the lubricant under the above conditions, and compare the amount of lubricant applied to maintain the image carrier surface friction coefficient at 0.2 under the image forming conditions of 50% image area ratio using polymerized toner. did. as a result,
In the case of (1) 0.04 g / km
In the case of (2) 0.35 g / km
Thus, it was confirmed that the method of applying the lubricant after cleaning and leveling with a leveling blade is more effective in reducing the friction coefficient of the image carrier surface than the cleaning method after applying the lubricant.

  The toner used in the developing device 11 has a volume average particle diameter of 10 μm or less, and a ratio Dv / Dn (dispersion degree) between the volume average particle diameter Dv and the number average particle diameter Dn of 1.00 to 1. It is preferable to use a toner in the range of 40, and it is particularly desirable that the volume average particle diameter is 3 to 8 μm.

  By using a toner having a small particle diameter, the toner can be densely attached to the electrostatic latent image. However, if the volume average particle size of the toner is too small, the two-component developer fuses the toner to the surface of the magnetic carrier during long-term agitation in the developing device, reducing the charging ability of the magnetic carrier, and as a one-component developer. When used, toner filming on the developing roller and toner fusion to the cleaning blade for thinning the toner are likely to occur. On the other hand, if the volume average particle size of the toner is too large, it becomes difficult to obtain a high-resolution and high-quality image, and the toner particle size fluctuates when the toner in the developer is balanced. Often becomes large.

  Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. However, it is not preferable that Dv / Dn exceeds 1.40 because the charge amount distribution becomes wide and the resolving power decreases.

  The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). Here, a Coulter counter TA-II type was used and connected to an interface (manufactured by Nikka Giken) and a personal computer (PC9801: manufactured by NEC) to output the number distribution and volume distribution.

  In the toner as described above, the ratio of the wax added to the toner to improve the releasability or the inorganic fine particles to improve the fluidity is small in the particle size. These additives become a factor of the adhered substances generated on the image carrier. However, by installing the lubricant application device 31, a uniform thin film of lubricant can be formed over the entire surface of the image carrier, and the adhesion force of these adhering substances to the image carrier surface can be reduced. The friction between the surface of the image carrier and the cleaning blade 28 and the leveling blade 32 of the cleaning device 26 can be reduced so that the cleaning can be performed satisfactorily.

  When the toner having the average circularity in the range of 0.93 to 1.00 is used in the current feeding device 11, the effect of applying the lubricant to the image carrier can be greatly obtained. This is because, by applying a lubricant to the image bearing member, even when such a toner having a high degree of circularity is used, a problem that the toner slips through the cleaning blade 28 can be effectively suppressed.

  The average circularity of the toner is a value obtained by optically detecting particles and dividing by the perimeter of an equivalent circle having the same projected area. Specifically, the measurement is performed using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

  The toner used in the developing device 11 preferably has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180. The shape factor SF-1 indicates the ratio of the roundness of the toner shape. When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases. The shape factor SF-2 indicates the ratio of unevenness in the shape of the toner. When the SF-2 value is 100, the unevenness does not exist on the toner surface, and the toner increases as the SF-2 value increases. Surface irregularities become prominent. For these, see JP-A-2002-244485.

  When the shape of the toner is close to a spherical shape, the contact between the toner and the toner or the toner and the image carrier is close to a point contact, so that the adsorption force between the toners is weakened, and thus the fluidity is increased. The attracting force with the image carrier is also weakened, and the transfer rate is increased. On the other hand, since the spherical toner easily enters the gap between the cleaning blade 28 and the image carrier, the toner shape factor SF-1 or SF-2 is preferably large to some extent. Further, when SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. For this reason, it is preferable that SF-1 and SF-2 do not exceed 180. Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated.

  The toner suitably used in the image forming apparatus of this example is, for example, a toner composition in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent are dispersed in an organic solvent. Is a toner obtained by cross-linking and / or extending reaction in the presence of resin fine particles in an aqueous solvent. Hereinafter, examples of the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner contains modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound. Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and a polyester having an active hydrogen group, a polyvalent isocyanate compound (PIC) And those reacted with. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Among these, alcoholic hydroxyl groups are preferred. The urea-modified polyester is produced as follows.

  Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

  Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The modified polyester (i) is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

  In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds). The molecular weight of the polymer produced can be measured using gel permeation chromatography (GPC) with THF as a solvent.

(Unmodified polyester)
Not only the modified polyester (i) can be used alone, but also this (i), unmodified polyester (ii) can be contained as a binder resin component. By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i), and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner deteriorates, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show. The glass transition point (Tg) can be measured with a differential scanning calorimeter (DSC).

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .

  The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × 10 −3 to 2 μm, and particularly preferably 5 × 10 −3 to 0.5 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle size of 5 × 10-2 μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause fireflies and the like is obtained, and a reduction in residual toner is further achieved. .

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.

  The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

  2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles. The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

  The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical. Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

  The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao Corporation), SGP (manufactured by Soken Co., Ltd.), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.). In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

  3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group. This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

  4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles. In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

  5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner. The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like. Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

  Further, the external shape of the toner is preferably a substantially spherical shape, which can be expressed by the following shape rule.

  FIG. 6 is a diagram schematically showing the shape of the toner. In FIG. 6, symbol T indicates a substantially spherical toner, and when the toner T is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner is The ratio of the minor axis to the major axis (r2 / r1) (see FIG. 5B) is in the range of 0.5 to 1.0, and the ratio of the thickness to the minor axis (r3 / r2) (FIG. 5 ( c) is preferably in the range of 0.7 to 1.0. If the ratio of the minor axis to the major axis (r2 / r1) is less than 0.5, the distance from the true spherical shape is inferior, so that dot reproducibility and transfer efficiency are inferior, and high quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved. Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

  The toner produced as described above can be used as a one-component magnetic toner that does not use a magnetic carrier or as a non-magnetic toner. In addition, when used in a two-component developer, it may be used by mixing with a magnetic carrier, and the magnetic carrier is a ferrite containing a divalent metal such as iron, magnetite, Mn, Zn, Cu, A volume average particle size of 20 to 100 μm is preferred. If the average particle size is less than 20 μm, carrier adhesion is likely to occur on the photoreceptor 1 during development, and if it exceeds 100 μm, the miscibility with the toner is low and the charge amount of the toner is insufficient, resulting in poor charging during continuous use. Cheap. In addition, Cu ferrite containing Zn is preferable because of high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus. The resin for coating the magnetic carrier is not particularly limited, and examples thereof include silicone resin, styrene-acrylic resin, fluorine-containing resin, and olefin resin. In the manufacturing method, the coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on the core, or the resin particles are electrostatically attached to the core particles and then thermally melted for coating. It may be a thing. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.

1 is a cross-sectional view illustrating an example of an image forming apparatus. It is an expanded sectional view of one process cartridge. It is explanatory drawing which shows the arrangement | positioning relationship of a brush roller, a solid lubricant, and a compression coil spring. It is explanatory drawing which shows a mode that the lubricant apply | coated on the image carrier is averaged with a leveling blade. FIG. 2 is a diagram illustrating a cleaning device that removes transfer residual toner on an image carrier including an intermediate transfer belt, and a lubricant application device that applies a lubricant to the surface of the intermediate transfer belt. FIG. 3 is a diagram illustrating an appearance shape of a toner.

Explanation of symbols

2Y, 2C, 2M, 2BK Image carrier 7Y, 7M, 7C, 7BK Process cartridge 10 Optical writing device 11 Developing device 26 Cleaning device 31, 131 Lubricant coating device 32, 132 Leveling blade 34, 134 Solid lubricant θ, θ1 angle

Claims (9)

A lubricant application device that applies a lubricant to the surface of an image carrier, a solid lubricant, an application roller that rotates while contacting the solid lubricant and the surface of the image carrier, and an image applied by the application roller In the lubricant application device having a leveling blade for leveling the lubricant on the carrier, the leveling blade has a JIS-A (K6301) hardness of 79 degrees or more. apparatus. The lubricant application device according to claim 1, wherein the leveling blade is disposed in a trailing direction with respect to a moving direction of the surface of the image carrier. The lubricant application device according to claim 1 or 2, wherein the contact angle of the leveling blade to the surface of the image carrier is 10 ° or more, and the contact linear pressure is 0.01 N / cm or more. An image carrier, a charging device that charges the image carrier, a developing device that visualizes an electrostatic latent image formed on the image carrier as a toner image, and a surface of the image carrier after the toner image is transferred. A process cartridge comprising at least one cleaning device for cleaning and the lubricant application device according to any one of claims 1 to 3. The process cartridge according to claim 4, wherein the cleaning device cleans the surface of the image carrier before the lubricant is applied by the lubricant application device. An image carrier, a charging device for charging the image carrier, an optical writing device for exposing the charged image carrier surface to form an electrostatic latent image, and the electrostatic latent image visible as a toner image An image forming apparatus comprising: a developing device that forms an image; a cleaning device that cleans the surface of the image carrier after the transfer of the toner image; and the lubricant application device according to claim 1. The image forming apparatus according to claim 6, wherein the cleaning device cleans the surface of the image carrier before the lubricant is applied by the lubricant application device. 8. The image forming apparatus according to claim 6, wherein a toner having an average circularity in a range of 0.93 to 1.00 is used. The image forming apparatus according to claim 6 or 7, wherein a toner having a shape factor SF-1 of 100 to 180 and a shape factor SF-2 of 100 to 180 is used.

Images