JP2005181742A - Image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which permits a stable cleaning performance from the beginning, irrespective of the formed image state and image area rate with regard to the color image forming apparatus or the like, and to provide a process cartridge used in the image forming apparatus. <P>SOLUTION: The image forming apparatus comprises a latent image carrier, a charging device, a latent image forming device, a developing device, a toner image transfer device, a cleaning device of cleaning toner, remaining on the latent image carrier with a cleaning blade and a lubricant applying means of applying lubricant on the latent image carrier. A new article photoreceptor unit detecting means is disposed on the body of an image forming apparatus. When a photoreceptor unit is detected as a new article, application operation, by means of the lubricant applying means, is performed. Therein, a control means, which measures a photoreceptor torque (detects the current value of a photoreceptor driving motor) and determines the application operation time, is disposed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus for an electrostatic copying process such as a copying machine, a facsimile machine, and a printer, and more particularly to an image forming apparatus that can be cleaned even with toner having a high average circularity.

  In recent years, color image forming apparatuses using an electrophotographic method have become widespread, and further high definition of printed images has been demanded due to the fact that digitized images can be easily obtained. ing. As higher resolution and gradation of images are being studied, as a toner-side improvement that visualizes latent images, further spheroidization and smaller particle size have been studied in order to form high-definition images. ing.

  Conventionally, for example, a pulverized pulverized toner having a specific particle size distribution (see, for example, Patent Documents 1 to 4), and a method for obtaining a sphere-shaped and small-sized toner by suspension polymerization (for example, , See Patent Document 5.) A binder resin and a colorant are mixed in a solvent immiscible with water and dispersed in an aqueous solvent in the presence of a dispersion stabilizer. A method for obtaining the resin (for example, refer to Patent Document 6), a binder resin containing a partially modified resin, and a colorant are mixed in an organic solvent and dispersed in an aqueous solvent, so that the weight of the modified resin is increased. There has been proposed a method (for example, refer to Patent Document 7) in which an addition reaction is performed to obtain a spherical and small-sized toner. With such toner, image quality and fluidity are improved.

  In particular, the spherical toner is suitable for obtaining a high-definition image because it is faithfully transferred. However, since the spherical toner is easy to roll, the toner between the cleaning blade and the photoreceptor in the cleaning device is easy to roll. It is difficult to clean up and may cause abnormal images such as ground fogging.

  For this purpose, for example, in an electrophotographic image forming method using a cleaning member that cleans toner remaining on a photoconductor with an elastic rubber blade after transfer to a recording material, zinc stearate in the toner is 0% of the toner weight. .01% or more and 0.5% or less, and the elastic rubber blade is substantially held on the photosensitive member contact surface side of the cleaning blade by the support member for fixing the elastic rubber blade to the cleaning member An image forming method has been proposed (for example, Patent Document 8). However, when zinc stearate is added to the toner, there is a problem that the zinc stearate on the photoreceptor becomes non-uniform depending on the state of the developed image.

  Further, an electrostatic latent image is formed on the image bearing member, and the electrostatic latent image is visualized as a toner image with a toner containing a release agent, and the toner image is directly or via an intermediate transfer member. In an image forming apparatus that transfers a toner image transferred to a recording medium and fixes the toner image transferred to the recording medium to the recording medium, an image forming apparatus that applies a lubricant to the image carrier has been proposed (for example, Patent Documents). 9).

  However, when an image having a high image area ratio is formed by the image mode, there is a problem that the amount of the zinc stearate on the photoreceptor becomes non-uniform because the amount of the toner adhering to the toner increases. That is, it is important to apply a uniform amount of stearic acid on the image carrier.

Japanese Patent Laid-Open No. 1-112253 JP-A-2-284158 Japanese Patent Laid-Open No. 3-181952 JP-A-4-162048 Japanese Patent Laid-Open No. 5-72808 Japanese Patent Laid-Open No. 9-15902 Japanese Patent Laid-Open No. 11-133668 Japanese Patent Laid-Open No. 11-184340 JP 2002-287567 A

  As described above, the spheroidized toner enters between the cleaning blade and the photosensitive member and may cause an abnormal image. When zinc stearate is added to the toner, the toner may be developed depending on the state of the developed image. The zinc stearate on the photoconductor becomes non-uniform, and in the case of a toner containing a release agent, when an image with a high image area ratio is formed, the amount attached to the toner and carried away increases. There is a problem that the zinc stearate becomes non-uniform and may cause an abnormal image.

  The present invention has been made in consideration of the above-described circumstances, and by measuring the photoconductor torque, the occurrence of abnormal images due to uneven application of zinc stearate on the photoconductor is prevented, and the formed image An object of the present invention is to provide an image forming apparatus and a process cartridge which have a stable cleaning performance from the beginning regardless of the state and the image area ratio.

  In order to solve the above-described problems, the invention described in claim 1 includes a latent image carrier, a charging device for charging the latent image carrier, a latent image forming device for forming a latent image, and a latent image as a toner. A transfer electric field is formed between the developing device that develops the toner and the latent image carrier and the surface moving member that moves while contacting the latent image carrier, and the toner image formed on the latent image carrier is transferred onto the recording material or A transfer device for transferring onto the surface moving member; a cleaning device for cleaning toner remaining on the latent image carrier with a cleaning blade; and a lubricant applying means for applying a lubricant to the latent image carrier of the image forming apparatus. In the image forming apparatus, a new photoreceptor unit detection unit is installed in the main body of the image forming apparatus. When the new unit detection unit detects that the photoreceptor unit is a new unit, it performs an application operation by the lubricant application unit, Body torque Constant, and wherein the image forming apparatus having a control means for determining a coating operation time.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the lubricant applying means includes a brush-like roller, and the brush-like roller scrapes and scrapes off the molded lubricant. And an image forming apparatus having means for applying a lubricant to the latent image carrier.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the lubricant application unit is a lubricant application unit using a fatty acid metal salt or fluorine fine particles as the lubricant. Features a forming device.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the lubricant applying unit includes a unit that presses the rod-shaped lubricant against the brush roller with a pressure of 100 mN or more. And an image forming apparatus having the same.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the ratio of the peripheral speed of the brush to the latent image carrier in the image forming apparatus is 0.8. The image forming apparatus is in the range of -1.2.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the toner used in the developing unit has a volume average particle diameter of 3 to 8 μm and a volume average particle diameter Dv. The image forming apparatus is characterized in that the ratio Dv / Dn to the number average particle diameter Dn is in the range of 1.00 to 1.40.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the toner used in the developing unit has a shape factor SF-1 in the range of 100 to 180, and the shape factor. An image forming apparatus having SF-2 in the range of 100 to 180 is characterized.

  According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, the toner used in the developing unit includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, The image forming apparatus is a toner obtained by crosslinking and / or extending a toner material liquid in which a colorant and a release agent are dispersed in an organic solvent in an aqueous medium.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the toner used in the developing unit has a substantially spherical shape.

  According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the shape of the toner used in the developing unit is a ratio of the minor axis to the major axis (r2 / r1). Is in the range of 0.5 to 1.0, the ratio of thickness to minor axis (r3 / r2) is in the range of 0.7 to 1.0, and the major axis r1 ≧ minor axis r2 ≧ thickness r3. The image forming apparatus satisfies the relationship.

  The invention according to claim 11 is the application selected from a latent image carrier that forms a latent image, a coating means that applies a lubricant to the latent image carrier, a charging device, a developing device, and a cleaning device. One or more apparatuses and / or means including a means are integrally supported, and the process cartridge is detachable from the image forming apparatus. The application means includes a brush-like roller, and the brush-like roller is a rod-like member. A mechanism for applying a lubricant when the process cartridge is detected as new, after the lubricant molded body is rubbed and scraped off. It features a process cartridge having the same.

  According to a twelfth aspect of the present invention, there is provided an image forming apparatus having the process cartridge according to the eleventh aspect mounted thereon.

  According to the present invention, in the image forming apparatus of the present invention, the photoconductor unit new article detecting means is installed in the image forming apparatus main body, and when the new article detecting means detects that the photoconductor unit is new, the lubricant applying means is provided. The image forming apparatus is characterized in that it has a control means for carrying out the coating operation, measuring the torque of the photosensitive member, and determining the coating operation time. It is possible to apply the amount of the toner, and it is possible to exhibit a stable cleaning performance by the cleaning means using the cleaning blade without causing the secondary member charging member contamination due to the lubricant application.

  In the process cartridge of the present invention, the latent image carrier for forming the latent image, the application means for applying the lubricant to the latent image carrier, and the application means selected from the charging device, the developing device, and the cleaning device. And a process cartridge that is detachably attached to the image forming apparatus, wherein the coating means includes a brush-like roller, and the brush-like roller rubs the lubricant molded body. Then, after the scraping, the lubricant is applied to the latent image carrier, and when the process cartridge is detected as new, the process cartridge having a mechanism for performing the lubricant application operation, By eliminating the difference in the presence state of the lubricant on the photoreceptor due to the difference in the image area ratio, stable cleaning performance can be exhibited.

  Further, the image forming apparatus equipped with the process cartridge can exhibit a stable cleaning performance by a cleaning means using a cleaning blade without causing secondary charging charging member contamination due to lubricant application. It has a stable cleaning performance from the beginning regardless of the rate.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an overall configuration diagram showing an example in which the present invention is applied to a full-color small printer.

  In an image forming apparatus main body (hereinafter simply referred to as “apparatus main body”) 1, image forming units 2 A, 2 B, 2 C, and 2 D each having a photoconductor 5 as an image carrier are attached to the apparatus main body 1. On the other hand, they are detachably attached. A transfer device 3 in which a transfer belt 3a is rotatably mounted in a direction indicated by an arrow A between a plurality of rollers is disposed at a substantially center of the device main body 1.

  The photosensitive member 5 provided in each of the image forming units 2A, 2B, 2C, and 2D is disposed so as to contact the upper surface of the transfer belt 3a. In correspondence with the image forming units 2A, 2B, 2C, and 2D, developing devices 10A, 10B, 10C, and 10D having different toner colors are arranged.

  The image forming units 2A, 2B, 2C, and 2D are units having the same configuration, the image forming unit 2A forms an image corresponding to magenta, and the image forming unit 2B forms an image corresponding to cyan. The image forming unit 2C forms an image corresponding to the yellow color, and the image forming unit 2D forms an image corresponding to the black color.

  A writing unit 6 is disposed above the image forming units 2A, 2B, 2C, and 2D, and a duplex unit 7 is disposed below the transfer belt 3a. This small printer is equipped with a reversing unit 8 on the left side of the apparatus main body 1 for reversing and ejecting the transfer paper P after image formation or transporting it to the duplex unit 7.

  The writing unit 6 is arranged in four laser diode (LD) light sources prepared for each color, a set of polygon scanners composed of six polygon mirrors and a polygon motor, and the route of each light source. It is composed of a lens such as an fθ lens or a long cylindrical lens, or a mirror. Laser light emitted from the laser diode is deflected and scanned by a polygon scanner and irradiated onto the photosensitive member 5.

  The duplex unit 7 includes a pair of conveyance guide plates 45a and 45b and a pair of (four sets in this example) conveyance rollers 46. In the double-sided image formation mode in which images are formed on both sides of the transfer paper P, Then, the transfer paper P on which an image is formed on one side and conveyed to the reversal conveyance path 54 of the reversing unit 8 and switched back is received, and conveyed to the paper feeding unit.

  The reversing unit 8 includes a plurality of paired transport rollers 46 and a plurality of paired transport guide plates 45. As described above, the reversing unit 8 reverses the transfer paper P when forming a double-sided image, so that the double-sided unit 7 is reversed. The transfer paper P after image formation is discharged to the outside of the apparatus in the same direction, or the front and back are reversed and discharged to the outside of the apparatus. Separating paper feeding units 55 and 56 for separating and feeding the transfer paper P one by one are provided in the paper feeding unit in which the paper feeding cassettes 11 and 12 are provided.

  Between the transfer belt 3a and the reversing unit 8, there is provided a fixing device 9 for fixing the image of the transfer paper P on which the image has been transferred. A reverse paper discharge path 20 is branched and formed on the downstream side of the fixing device 9 in the transfer paper conveyance direction, and the transfer paper P conveyed there can be discharged onto a paper discharge tray 26 by a pair of paper discharge rollers 25. Yes.

  Further, in the lower part of the apparatus main body 1, paper feed cassettes 11 and 12 that can store transfer papers P having different sizes are arranged in two upper and lower stages. Further, a manual feed tray 13 is provided on the right side surface of the apparatus main body 1 so as to be openable and closable in the direction indicated by the arrow B, and the manual feed tray 13 is opened so that manual feeding can be performed therefrom.

Next, the operation of the image forming apparatus in image formation will be described.
When the image forming operation is started, each photoconductor rotates in the clockwise direction in FIG. The surface of each photoreceptor 5 is uniformly charged by the charging roller 14a. Then, laser light corresponding to a magenta image is written to the photoconductor 5 of the image forming unit 2A by the writing unit 6, and laser light corresponding to a cyan image is applied to the photoconductor 5 of the image forming unit 2B. The 2C photoconductor 5 is irradiated with a laser beam corresponding to a yellow image, and the photoconductor 5 of the image forming unit 2D is irradiated with a laser beam corresponding to a black image, and a latent image corresponding to the image data of each color. Are formed respectively. Each latent image reaches the position of the developing devices 10A, 10B, 10C, and 10D by the rotation of the photosensitive member 5, and is developed there by toners of magenta, cyan, yellow, and black. Become. At this time, the lubricant externally added to the toner is simultaneously supplied to the surface of the photoreceptor.

  On the other hand, the transfer paper P is fed from the paper feeding cassettes 11 and 12 by the separation paper feeding sections 55 and 56, and is formed on each photoconductor 5 by the registration roller pair 59 provided immediately before the transfer belt 3a. The toner image is conveyed at a timing that coincides with the toner image. The transfer paper P is charged to a positive polarity by a paper suction roller 58 disposed in the vicinity of the entrance of the transfer belt 3a, and thereby electrostatically attracted to the surface of the transfer belt 3a. Then, while the transfer paper P is conveyed while being adsorbed to the transfer belt 3a, magenta, cyan, yellow and black toner images are sequentially transferred to form a four-color full color toner image. The At this time, the lubricant externally added to the toner is also transferred at the same time, but a part of the toner is not transferred but remains attached to the photoreceptor. The transfer paper P is melted and fixed by applying heat and pressure by the fixing device 9, and then passes through the paper discharge system corresponding to the designated mode, and then the paper discharge tray 26 at the top of the apparatus main body 1. When the paper is discharged straight from the fixing device 9 and straightly discharged through the reversing unit 8 or when the double-sided image forming mode is selected, the reversing conveyance path in the reversing unit 8 described above. The image forming unit 2A, 2B, 2C, and 2D is provided with the image forming units 2A, 2B, 2C, and 2D, and an image is formed on the back surface. It is discharged after.

  On the other hand, the photosensitive member 5 separated from the transfer belt 3a continues to rotate as it is, and a brush-like roller 17a, which will be described later, applies the lubricant scraped off from the molded lubricant 17b to the photosensitive member 5. Further, untransferred residual toner exists on the photoconductor 5, and a lubricant adheres to the surface thereof. When the residual toner is cleaned with a cleaning blade, the lubricant on the toner forms a film on the surface of the photoconductor 5 in order to press the toner against the photoconductor 5. At the same time, the lubricant supplied from the brush roller 17 a and on the photoconductor 5 is also pressed against the photoconductor 5 to form a film on the photoconductor 5.

  In the subsequent image formation, the above-described image forming process is repeated. However, the lubricant film formed on the photoconductor 5 is very thin, so that charging by the charging device 14 is not hindered. Thereafter, the toner image developed again on the photosensitive member 5 is transferred onto the transfer paper P in a state of being attracted to the transfer belt 3a.

  The developing devices 10A, 10B, 10C, and 10D include a developing roller that faces the photoreceptor 5, a screw that conveys and stirs the developer, a toner concentration sensor, and the like. The developing roller is composed of an outer rotatable sleeve and an inner magnet. In accordance with the output of the toner density sensor, toner is supplied from the toner supply device. In this embodiment, a two-component developer composed of toner and carrier is used as the developer.

  The carrier is generally composed of the core material itself, or a carrier provided with a coating layer on the core material. Examples of the core material of the resin-coated carrier that can be used in the present invention include ferrite and magnetite. The particle size of the core material is preferably 20 to 65 μm, more preferably about 30 to 60 μm. As the resin used for forming the carrier coating layer, a styrene resin, an acrylic resin, a fluororesin, a silicone resin, a mixture thereof, a copolymer, or the like can be used. As a method for forming the coating layer, a resin may be applied to the surface of the carrier core material particles by a spraying method, a dipping method, or the like, as in the conventional case.

  FIG. 2 is a schematic diagram showing the configuration of the image forming unit. As shown in FIG. 2, the image forming units 2A, 2B, 2C, and 2D include a charging roller 14a, a photoreceptor 5 on which an electrostatic latent image is formed, and a cleaning blade 15a that cleans the surface of the photoreceptor 5. It comprises a cleaning means 15 provided and an application means 17 provided with a brush-like roller 17a for applying a lubricant.

  The charging roller 14 a is conductive or semiconductive, and applies a direct current and / or alternating current voltage to apply a charge to the photoreceptor 5 to charge the photoreceptor 5. A charging roller cleaning brush 14b for cleaning the roller surface is in contact with the charging roller 14a.

  In the cleaning means, the toner scraped off by the cleaning blade 15a is moved to the toner transport auger side by the brush roller 17a, and the waste toner collected by rotating the toner transport auger is stored in the waste toner storage section shown in FIG. To be transported.

  The application means 17 is incorporated in the image forming unit main body here, and the lubricant molded body 17b and the brush-like roller 17a which contacts the lubricant molded body 17b to scrape off the lubricant and supply it to the surface of the photoreceptor 5. And a brush roller scraper 17c for removing toner adhering to the brush roller 17a, and a pressure spring 17d for pressing the lubricant molding 17b against the brush roller 17a with a predetermined pressure. The lubricant molding 17b is formed in a rectangular parallelepiped shape. The brush-like roller 17 a has a shape extending in the axial direction of the photosensitive member 5. The pressure spring 17d is urged against the brush roller 17a so that almost all of the lubricant molding 17b can be used up. Since the lubricant molded body 17b is a consumable product, its thickness decreases with time, but since it is pressurized by the pressure spring 17d, the lubricant is scraped off by always contacting the brush roller 17a. Thereafter, the photosensitive member 5 is supplied and applied.

  As shown in FIG. 1, the developing devices 10A, 10B, 10C, and 10D all have the same configuration, and the developing devices 10A, 10B, 10C of the two-component developing system differing only in the color of the toner used. 10D. The developing device 10A uses magenta toner, the developing device 10B uses cyan toner, the developing device 10C uses yellow toner, and the developing device 10D uses black toner. . In the developing devices 10A, 10B, 10C, and 10D for the respective colors, a developer composed of toner and a carrier is accommodated.

  When the photoconductor unit (image forming unit) 2 is new, the lubricant is not applied to the photoconductor 5. Further, since the solid lubricant 17b is soft and fragile, a new solid lubricant 17b is coated. Since this coating layer is a little hard, it takes some time for the coating layer to be scraped. Further, if the toner adheres to the brush-like roller 17a serving as both the lubricant applying means and the toner collecting means, the application efficiency from the solid lubricant 17b to the photosensitive member 5 is reduced, and the toner is attached. In the portion that is not attached to the portion, unevenness in the application of the lubricant occurs on the photoreceptor. Therefore, if there is unevenness in the friction coefficient on the photoconductor 5, the transfer rate from the toner image on the photoconductor 5 to the transfer paper is different, and an image having a uniform density cannot be obtained. In addition, it is known that a toner having a small particle size and a high degree of circularity, such as a polymerized toner, is difficult to clean if the coefficient of friction of the photosensitive member is high, and if the coefficient of friction of the photosensitive member 5 is small, cleaning properties are advantageous. It has been known. It is necessary to reduce the friction coefficient uniformly from the initial stage of the photoconductor unit 2. Once the lubricant is applied to the photoconductor 5 and the friction coefficient becomes saturated, the lubricant can be supplied to the photoconductor 5 as long as the friction coefficient can be maintained even if it adheres to the brush roller 17a.

  In order to set the coefficient of friction of the photosensitive member 5 to 0.4 or less from the beginning, a lubricant application operation is performed when the main body detects that the photosensitive member unit 2 is new. This new article detection may be performed by mechanical means on the photosensitive unit 2, or may be performed by providing a storage means such as an IC chip or by software.

Next, the optimum amount of lubricant application will be described.
It is desirable to regulate the amount of lubricant applied to the photoreceptor to the minimum necessary amount. If the lubricant is applied excessively, it adheres to the charging member that is in contact with the photoreceptor. When the lubricant adheres to the charging member, adhesion of the additive contained in the toner and the toner itself becomes significant, and the charging member is significantly stained. When the charging member is contaminated, the surface potential of the photosensitive member becomes non-uniform and an image density difference occurs. If it gets worse, soiling may occur. Therefore, it is necessary to control the lubricant application operation to the minimum necessary amount under the above conditions. The operation time is controlled by using the current value of the photoconductor motor and controlling the photoconductor torque.

  As the lubricant is applied to the photoconductor, the coefficient of friction of the photoconductor decreases and the photoconductor torque also decreases. That is, the addition to the photoconductor motor is reduced, and the motor current is reduced, so that the photoconductor torque can be controlled. The specified motor current value depends on the motor specification and the machine body specification, so it cannot be specified numerically.

  Examples of the lubricant for the molded lubricant 17b include lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate, linolene. Fatty acid metal salts such as zinc acid, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, polydichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoro Examples thereof include fluorine resins such as a propylene copolymer. In particular, a metal stearate having a large effect of reducing the friction of the photoreceptor 5 and further zinc stearate are more preferable.

  By supplying this lubricant to the surface of the photoconductor 5, a film of the lubricant is formed on the surface of the photoconductor 5, and the friction coefficient is set to 0.4 or less, for example. The coefficient of friction of the photoreceptor 5 is preferably 0.4 or less, and more preferably 0.2 or less. When the friction coefficient is 0.4 or less, the interaction between the photoconductor 5 and the toner is reduced, and the toner on the photoconductor 5 can be easily separated to increase the transfer rate.

  Further, it is possible to suppress an increase in friction between the cleaning blade 15a and the photosensitive member 5 and improve the cleaning efficiency. In particular, in the case of toner having a high degree of circularity, the toner easily rolls on the photoconductor 5, so that the occurrence of poor cleaning can be suppressed. Further, the occurrence of cleaning failure due to long-term use can be suppressed by increasing the transfer rate and reducing the amount of toner to be cleaned. Furthermore, 0.2 or less is more preferable. On the other hand, if the friction coefficient is less than 0.1, a cleaning failure occurs that slips too much between the cleaning blade 15a and slips through the toner cleaning blade 15a on the photoreceptor 5.

  Here, the friction coefficient of the photosensitive member 5 was measured by the Euler belt method as follows. FIG. 3 is a diagram for explaining a method of measuring the friction coefficient of the photosensitive member 5. In this case, medium-quality high-quality paper 31 as a belt is stretched around the circumference of the drum circumference of the photoconductor so that the paper is in the longitudinal direction, and a load 32 of, for example, 0.98 N (100 gr) is applied to one of the belts. The force gauge is installed on the other side, the force gauge 33 is pulled, the load when the belt moves is read, and the friction coefficient μs = 2 / π × 1n (F / 0.98) (where μ is stationary) (Friction coefficient, F: measured value). Note that the friction coefficient of the photoconductor 5 in this image forming apparatus is a value when the image forming apparatus is in a steady state by image formation. This is because the coefficient of friction of the photoconductor 5 is affected by other apparatuses arranged in the image forming apparatus, and therefore changes from the value of the coefficient of friction immediately after image formation. However, the value of the friction coefficient becomes a substantially constant value by forming about 1,000 images on A4 size recording paper. Therefore, the coefficient of friction referred to here means the coefficient of friction when it becomes constant in the steady state.

  Here, the lubricant applying means 17 will be described with reference to FIG. First, as the lubricant, one obtained by melting and solidifying a fatty acid metal salt such as zinc stearate and processing into a rod shape, or one obtained by molding a fluororesin such as polytetrafluoroethylene into a rod shape or a sheet shape can be used. These lubricants are fixed to the holding member and brought into contact with the brush roller 17a. When adjusting the lubricant application amount, the application amount to the photoconductor 5 can be adjusted with a spring material. This also increases the life of the lubricant.

  Here, the molded lubricant 17b is pressed against the brush roller 17a by a pressure spring 17d including its own weight, preferably with a pressure of 100 mN or more, more preferably 200 mN or more. As the pressure increases, the amount of lubricant that the brush scrapes off from the molded lubricant 17b increases, and the amount of lubricant applied to the photoreceptor 5 increases, so that the friction coefficient of the photoreceptor 5 can be reduced. .

  Further, the brush-like roller 17a is rotated in the same direction at a portion in contact with the photoreceptor 5. By rotating in this direction, the lubricant adhering to the brush roller 17a can be supplied without giving an impact to the photoreceptor 5. There is no need to form a lubricant film when the brush roller 17a supplies the photosensitive member 5, and the lubricant supplied on the photosensitive member 5 forms a lubricant film by the pressing force of the cleaning blade 15a. To do. Therefore, it is preferable here to rotate in the same direction in order to supply without impact. Further, the peripheral speed ratio between the brush roller 17a and the photoconductor 5 (photoconductor peripheral speed / peripheral speed of the brush roller) is preferably in the range of 0.8 to 1.2. When the peripheral speed ratio is less than 0.8, the supply amount of the lubricant decreases, and when it exceeds 1.2, the photoreceptor 5 may be damaged by impact, and the life of the photoreceptor 5 may be shortened. Further, in order to supply the lubricant from the brush to the photoconductor 5 with a small impact, it is further preferable that the ratio is in the range of 1.0 to 1.1.

  FIG. 4 is a schematic diagram illustrating the configuration of the toner. Here, the toner containing the lubricant 61 and supplying the lubricant to the photoreceptor 5 will be described. The toner is composed of at least a binder resin 62 and a colorant 63, and an external additive 64 that imparts fluidity is externally added to the toner surface. In addition, a charge control agent 65 that controls the chargeability of the toner, A release agent 66 or the like that improves the releasability of the fixing device may be contained.

  The binder resin is an ester resin, a vinyl resin, an amide resin, an epoxy resin, a silicone resin, or the like, and a vinyl resin is particularly preferable. Specifically, styrene such as polystyrene, poly P-chlorostyrene, polyvinyltoluene, and the like Homopolymer of the substituted product, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate Copolymer, styrene-ethyl acrylate copolymer, styrene-butyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-butadiene copolymer, styrene-meta Use methyl acrylate-butyl acrylate copolymer, etc. Rukoto can.

  As the colorant, all 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, bengara, red lead, lead vermilion, cadmium red, cadmium mercurial red, antimony vermilion, permanent red 4R, para red, phise red, parachlor ortho nitroaniline red, risor fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Per Nent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean blue, alkali blue rake, peacock blue rake, Victoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone Violet, chrome green, zinc green, pigment green B, naphthol green B, green Ngorudo, titanium oxide, zinc white, lithopone 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.

  As the charge control agent, for example, a salicylic acid compound, a nigrosine dye, a quaternary ammonium salt compound, an alkylpyridinium compound, or the like can be used. The content is usually from 0.1 to 5% by weight, preferably from 1 to 3% by weight, based on the toner.

  As the release agent, for example, polyolefin wax such as low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight polyethylene-polypropylene copolymer, ester wax such as fatty acid lower alcohol ester, fatty acid higher alcohol ester, fatty acid polyhydric alcohol ester, An amide wax or the like can be used. The content is usually 0.5 to 10% by weight, preferably 1 to 5% by weight, based on the toner.

  The toner preferably has a circularity of 0.92 or more. Circularity SR = (peripheral length of a circle having the same area as the particle projection area / perimeter length of the particle projection image) × 100%. The closer the toner is to a true sphere, the closer to 100%. In the conventional image forming apparatus, when such toner is used, there is a case where the toner cannot be sufficiently scraped by the contact of the cleaning member such as the cleaning blade 15a. This is because the toner easily rolls on the photoreceptor 5. In this case, as a countermeasure, it is conceivable that the cleaning blade 15a is brought into contact with the photoconductor 5 with a stronger force, but this affects the rotation or movement accuracy of the photoconductor 5 and causes banding. In contrast, the lubricant is applied to the surface of the photoconductor 5 from both the coating unit 17 and the toner, and the friction coefficient on the surface of the photoconductor 5 is reduced, thereby increasing the transfer rate during transfer and reducing the residual toner. Thus, the burden of cleaning by the cleaning blade 15a can be reduced, and cleaning can be performed without banding even when the cleaning blade 15a comes into contact with a strong force.

  This degree of circularity is thermally or mechanically spheroidized with toner produced by dry grinding. Thermally, for example, the spheronization treatment can be performed by spraying toner base particles together with a hot air stream on an atomizer or the like. In addition, a spheroidizing treatment can be performed by mechanically charging the mixture into a mixer such as a ball mill together with a mixed medium such as glass having a low specific gravity and stirring. However, in the thermal spheronization process, toner base particles that are aggregated and have a large particle size or fine particles are generated in the mechanical spheronization process, and thus a second classification step is required. In addition, in a toner manufactured in an aqueous solvent, the shape can be controlled by applying strong stirring in the process of removing the solvent.

  Furthermore, a fluidity imparting agent may be added to the toner. Examples of the fluidity-imparting agent include fine particles of metal oxides such as silica, titania, alumina, magnesia, zirconia, ferrite, and magnetite, and metal oxides obtained by treating these fine particles with a silane coupling agent, titanate coupling agent, or zircoaluminate. Such as fine particles. Silica and titania hydrophobized with a coupling agent are preferred. Since the primary particle diameter of silica is small, the effect of imparting fluidity is large. Further, titania can control the toner charge amount. It is more preferable to add these in combination.

  Further, since the toner having a smaller volume average particle diameter Dv can improve the reproducibility of fine lines, a toner having a maximum particle size of 8 μm or less is used. However, since the developing property and the cleaning property are lowered when the particle size is small, at least 3 μm is preferable. Further, if the particle size is less than 3 μm, the toner having a small particle diameter that is difficult to be developed on the surface of the carrier or the developing roller increases. This is not preferable because an abnormal image such as fogging is formed.

  Moreover, it is preferable that the particle size distribution represented by ratio (Dv / Dn) of volume average particle diameter Dv and number average particle diameter Dn is the range of 1.05-1.40. By sharpening the particle size distribution, the toner charge amount distribution can be made uniform. When Dv / Dn exceeds 1.40, the toner charge amount distribution is wide and the amount of the reversely charged toner T1 increases, making it difficult to obtain a high-quality image. If Dv / Dn is less than 1.05, it is difficult to produce and it is not practical. The particle size of the toner is 50,000 by using a Coulter Counter Multisizer (manufactured by Coulter Co., Ltd.) and selecting an aperture having a measurement hole size of 50 μm corresponding to the particle size of the toner to be measured. It is obtained by measuring the average particle size of the particles.

The toner preferably has a shape factor SF-1 in the range of 100 or more and 180 or less and a shape factor SF-2 in the range of 100 or more and 180 or less in the circularity. 5A and 5B are diagrams schematically illustrating the shape of the toner. FIG. 5A is a diagram for explaining the shape factor SF-1, and FIG. 5B is a diagram for explaining the shape factor SF-2. The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (1)
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 the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner onto the two-dimensional plane by the figure area AREA and multiplying by 100 / 4π.
SF-2 = {(PERI) ² / AREA} × (100 / 4π) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.), introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) and analyzing it. Calculated.

When the shape of the toner is close to a sphere, the contact between the toner and the toner or the photoconductor 5 becomes a point contact, so that the adsorbing force between the toners becomes weak, and as a result, the fluidity increases, and the toner and the photoconductor 5, the transfer rate is increased, and the reversely charged toner T1 is easily collected by the temporary holding device.
The shape factors SF-1 and SF-2 of the toner are preferably 100 or more. Further, as SF-1 and SF-2 increase, the amount of the reversely charged toner T1 increases, the toner charge amount distribution increases, and the load on the temporary holding device 40 increases. For this reason, SF-1 preferably does not exceed 180, and SF-2 also preferably does not exceed 180.

  Further, the toner used in this image forming apparatus may be substantially spherical.

FIG. 6 is a schematic view showing the outer shape of the toner, FIG. 6A is an appearance of the toner, and FIG. 6B is a cross-sectional view of the toner. In FIG. 6A, the X axis represents the longest axis r1 of the longest axis of the toner, the Y axis represents the shortest axis r2 of the next longest axis, and the Z axis represents the thickness r3 of the shortest axis. ≧ Short axis r2 ≧ Thickness r3
The toner used in the present invention has a ratio of the minor axis to the major axis (r2 / r1) of 0.5 to 1.0 and a ratio of the thickness to the minor axis (r3 / r2) of 0.7 to 1. It preferably has a substantially spherical shape represented by 0. When the ratio of the minor axis to the major axis (r2 / r1) is less than 0.5, the charge amount distribution becomes wide because it approaches an indefinite shape.
When the ratio of the thickness to the short axis (r3 / r2) is less than 0.7, the charge amount distribution becomes wide because the shape approaches an indefinite shape. In particular, when the ratio of the thickness to the short axis (r3 / r2) is 1.0, the charge amount distribution becomes narrow because of the substantially spherical shape.
The size of the toner so far was measured with a scanning electron microscope (SEM) while changing the angle of the field of view and observing in situ.

  The shape of the toner can be controlled by the manufacturing method. For example, the toner by the dry pulverization method has an irregular shape in which the toner surface is uneven and the toner shape is not constant. Even this dry pulverized toner can be made into a nearly spherical toner by applying mechanical or thermal treatment. In many cases, a toner produced by forming droplets by a suspension polymerization method or an emulsion polymerization method has a smooth surface and a nearly spherical shape. Moreover, it can be made into an ellipse by stirring in the middle of the reaction in a solvent and applying a shearing force.

  The toner suitably used in the image forming apparatus of the present invention includes a toner material liquid 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. A toner obtained by crosslinking and / or elongation reaction in an aqueous solvent. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(polyester)
The polyester is obtained by a polycondensation reaction between a polyhydric alcohol compound and a polycarboxylic acid compound.
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.

  The polycondensation reaction between a polyhydric alcohol (PO) and a polycarboxylic acid (PC) is carried out in the presence of a known esterification catalyst such as tetrabutoxytitanate or dibutyltin oxide, and heated to 150 to 280 ° C. while reducing the pressure as necessary. The produced water is distilled off to obtain a polyester having a hydroxyl group. The hydroxyl value of the polyester is preferably 5 or more, and the acid value of the polyester is usually 1 to 30, preferably 5 to 20. By giving an acid value, it tends to be negatively charged, and furthermore, when fixing to a recording paper, the affinity between the recording paper and the toner is good and the low-temperature fixability is improved. However, when the acid value exceeds 30, there is a tendency to deteriorate with respect to the stability of charging, particularly environmental fluctuation.

  The weight average molecular weight is preferably 10,000 to 400,000, more preferably 20,000 to 200,000. A weight average molecular weight of less than 10,000 is not preferable because offset resistance deteriorates. On the other hand, if it exceeds 400,000, the low-temperature fixability is deteriorated.

  In addition to the unmodified polyester obtained by the above polycondensation reaction, the polyester preferably contains a urea-modified polyester. The urea-modified polyester is obtained by reacting a terminal carboxyl group or hydroxyl group of the polyester obtained by the above polycondensation reaction with a polyvalent isocyanate compound (PIC) to obtain a polyester prepolymer (A) having an isocyanate group. It is obtained by cross-linking and / or extending the molecular chain by the reaction of the amine with amines.

  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; phenol derivatives, oximes, 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% by weight, preferably 1 to 30% by weight, more preferably 2 to 20% by weight. %. If it is less than 0.5% by weight, 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% by weight, 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 urea-modified polyester is produced by a one-shot method or the like. For example, water produced by heating polyhydric alcohol (PO) and polycarboxylic acid (PC) to 150 to 280 ° C. in the presence of a known esterification catalyst such as tetrabutoxy titanate or dibutyltin oxide, and reducing the pressure as necessary. Is distilled off to obtain a polyester having a hydroxyl group. Subsequently, at 40-140 degreeC, this is made to react with polyvalent isocyanate (PIC), and the polyester prepolymer (A) which has an isocyanate group is obtained. Further, this (A) is reacted with amines (B) at 0 to 140 ° C. to obtain a urea-modified polyester.

  When reacting (PIC) and when reacting (A) and (B), a solvent may be used if necessary. Usable solvents include aromatic solvents (toluene, xylene, etc.); ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.); esters (ethyl acetate, etc.); amides (dimethylformamide, dimethylacetamide, etc.) and ethers And those inert to isocyanates (PIC), such as tetrahydrofuran (such as tetrahydrofuran).

  In addition, in the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B), a reaction terminator can be used as necessary to adjust the molecular weight of the resulting urea-modified polyester. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

  The weight average molecular weight of the urea-modified polyester is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000. If it is less than 10,000, the hot offset resistance deteriorates. The number average molecular weight of the urea-modified polyester or the like is not particularly limited when the above-mentioned unmodified polyester is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. When the urea-modified polyester is used alone, its number average molecular weight is usually 2000-15000, preferably 2000-10000, more preferably 2000-8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus are deteriorated.

  By using the unmodified polyester and the urea-modified polyester in combination, the low-temperature fixability and the glossiness when used in a full-color image forming apparatus are improved. Therefore, it is preferable to use the urea-modified polyester alone. The unmodified polyester may include a polyester modified with a chemical bond other than a urea bond. The unmodified polyester and the urea-modified polyester are preferably at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance. Therefore, it is preferable that the unmodified polyester and the urea-modified polyester have a similar composition.

  The weight ratio of unmodified polyester to urea-modified polyester is usually 20/80 to 95/5, preferably 70/30 to 95/5, more preferably 75/25 to 95/5, and particularly preferably 80 /. 20-93 / 7. When the weight ratio of the urea-modified polyester is less than 5% by weight, the hot offset resistance is deteriorated and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The glass transition point (Tg) of the binder resin containing unmodified polyester and urea-modified polyester is usually 45 to 65 ° C, preferably 45 to 60 ° C. If it is less than 45 ° C., the heat resistance of the toner deteriorates, and if it exceeds 65 ° C., the low-temperature fixability becomes insufficient.
In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the heat-resistant storage stability tends to be good even when the glass transition point is low as compared with known polyester-based toners.

(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 a 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 developer fluidity is lowered, and the image density is lowered. Invite.

(Release agent)
As the 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 binder resin dispersion between the fixing roller and the toner interface. Effective against high temperature offset 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 petrolatum. And petroleum wax. 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, 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, fatty acid amides such as chlorinated hydrocarbons, and low molecular weight crystalline polymer resins, 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 ~2μm, it is particularly preferably 5 × ¹⁰ -3 ~0.5μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.

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 diameter 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 to obtain a good image quality that does not cause the release of the fluidity imparting agent from the toner and does not generate firefly, etc., and further reduces the residual toner. It is done.

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 addition amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5% by weight, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained. Stable image quality can be obtained even when repeated.

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 2000 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 increased 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).

  Further, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or tertiary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a fluoroalkyl group on the right is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), 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.), Technopolymer There are SB (manufactured by Sekisui Plastics Co., Ltd.), SGP-3G (manufactured by Sokensha), Micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.) and the like.
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 usually 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 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 photosensitive member 5 for forming a latent image, the application unit 17 for applying a lubricant to the photosensitive member 5, and one or more devices including an application unit selected from the charging device 14, the developing device, and the cleaning device; Is a process cartridge that is integrally supported and detachable from the main body of the image forming apparatus. The coating means 17 includes a brush-like roller 17a, and the brush-like roller 17a slides a rod-like or other lubricant molding. After rubbing and scraping, a lubricant is applied to the photoreceptor 5, and the toner used in the image forming apparatus preferably contains a lubricant and is a process cartridge that supplies the photoreceptor 5 with the lubricant. is there. As a result, the life of the photoconductor 5 accommodated in the process cartridge can be extended, and when the maintenance becomes necessary, the process cartridge can be replaced, and the convenience is improved.

1 is an overall configuration diagram of an example in which an image forming apparatus of the present invention is applied to a color printer. 1 is an overall configuration diagram of an image forming unit of an image forming apparatus of the present invention. It is a figure for demonstrating the measuring method of the friction coefficient of the photoconductor of this invention. FIG. 3 is a schematic diagram illustrating a configuration of a toner used in the present invention. FIG. 6 is a diagram schematically illustrating the shape of the toner of the present invention, and an explanatory diagram of the shape based on the difference in shape factor. FIGS. 6A and 6B are schematic views illustrating an outer shape of the toner of the present invention, FIG. 6A is an appearance of the toner, and FIG. 6B is a cross-sectional view of the toner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image forming unit 3 Transfer apparatus 3a Transfer belt 5 Photoconductor (image carrier)
6 Writing unit 7 Double-sided unit 8 Reversing unit 9 Fixing device 10 Developing device 11, 12 Paper feed cassette 13 Manual feed tray 14 Charging device 14a Charging roller 14b Charging roller cleaning brush 15 Cleaning means 15a Cleaning blade 15b Blade pressure spring 15c Blade rotation Support point 15d Waste toner collection coil 17 Application means 17a Brush roller 17b Molded lubricant 17c Brush roller scraper 17d Pressure spring 20 Reverse paper discharge path 25 Roller pair 26 Paper output tray 31 Paper (belt)
32 Load 33 Force gauge 45a, 45b Conveying guide plate 46 Conveying roller 54 Reverse conveying path 55, 56 Separating paper feeding unit 58 Paper adsorbing roller 59 Registration roller pair 61 Lubricant 62 Binder resin 63 Colorant 64 External additive 65 Charge control Agent 66 Release Agent P Transfer Paper

Claims (12)

  A latent image carrier, a charging device that charges the latent image carrier, a latent image forming device that forms a latent image, a developing device that develops the latent image with toner, a latent image carrier, and a surface in contact with the latent image carrier A transfer electric field is formed between the moving surface moving member and the toner image formed on the latent image carrier to transfer the toner image onto the recording material or the surface moving member, and the latent image carrier remains on the latent image carrier. An image forming apparatus having a cleaning device for cleaning toner to be cleaned with a cleaning blade and a lubricant application unit for applying a lubricant to a latent image carrier of the image forming apparatus. The new article detecting means is provided with a control means for performing the application operation by the lubricant applying means, measuring the photoconductor torque, and determining the application operation time when the photoconductor unit is detected as new. Special An image forming apparatus.   The lubricant application means includes a brush-like roller, and the brush-like roller has means for applying the lubricant to the latent image carrier after the lubricant molding is rubbed and scraped off. The image forming apparatus according to claim 1.   3. The image forming apparatus according to claim 1, wherein the lubricant applying unit is a lubricant applying unit that uses a fatty acid metal salt or fine fluorine particles as the lubricant.   The image forming apparatus according to claim 1, wherein the lubricant applying unit includes a unit that presses the rod-shaped lubricant against the brush roller with a pressure of 100 mN or more.   5. The image according to claim 1, wherein a ratio of a peripheral speed of the brush to the latent image carrier in the image forming apparatus is in a range of 0.8 to 1.2. Forming equipment.   The toner used in the developing unit has a volume average particle diameter of 3 to 8 μm and a ratio Dv / Dn of the volume average particle diameter Dv to the number average particle diameter Dn is in the range of 1.00 to 1.40. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The toner used in the developing unit 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 image forming apparatus described.   The toner used in the developing means crosslinks a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent in an aqueous medium. The image forming apparatus according to claim 1, wherein the toner is obtained by an extension reaction.   The image forming apparatus according to claim 1, wherein the toner used in the developing unit has a substantially spherical shape.   The shape of the toner used in the developing means is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and the ratio of the minor axis r2 to the major axis r1 ( r2 / r1) is in the range of 0.5 to 1.0, and the ratio (r3 / r2) of the thickness r3 to the minor axis r2 is in the range of 0.7 to 1.0. Item 10. The image forming apparatus according to any one of Items 1 to 9.   One or more apparatuses including a latent image carrier for forming a latent image, an application unit for applying a lubricant to the latent image carrier, and the application unit selected from a charging device, a developing device, and a cleaning device, and / or Or a process cartridge that is integrally supported by the image forming apparatus and that can be attached to and detached from the image forming apparatus, wherein the applying means includes a brush-like roller, and the brush-like roller scrapes and scrapes the lubricant molding. A process cartridge for applying a lubricant to the latent image carrier and performing a lubricant application operation when the process cartridge is detected as new.   An image forming apparatus comprising the process cartridge according to claim 11.

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