JP2008026354A - Image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress contamination of a charging member due to excess supply of a lubricant with time, in an image forming apparatus equipped with a lubricant-applying means for applying a lubricant on a latent image carrier so as to prevent cleaning fault of the latent image carrier and filming. <P>SOLUTION: The lubricant-applying means for applying a lubricant on a photoreceptor comprises a lubricant 17b; a brush roller 17a which is brought into contact with the lubricant and the surface of the photoreceptor; a pressure spring 17d for pressing the lubricant against the brush roller side; and a spring support member 17e which supports the pressure spring, wherein one end of the pressure spring on the lubricant side is a free end, the other end is supported by the spring support member. The spring support member is disposed so that the interval between the spring support member and the lubricant is kept smaller than the free length of the pressure spring in the initial stages; and so that when the volume of the lubricant decreases with time, the interval between the spring support member and the lubricant is larger than the free length of the pressure spring. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, and a printer, and a process cartridge employed in the image forming apparatus.

  In recent years, 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. Yes. In such a trend toward higher definition, as a toner-side improvement for visualizing a latent image, further spheroidization and smaller particle size have been studied.

  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 spherical, small-sized toner by suspension polymerization (for example, Patent Document). 5), a method in which 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 to obtain a spheroidized and small-sized toner ( 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, and a polyaddition reaction of the modified resin is performed. A method (for example, see Patent Document 7) for obtaining a toner having a spherical shape and a small particle size is proposed. With such toner, image quality and fluidity are improved.

  In particular, the spheroidized toner is suitable for obtaining a high-definition image because it is faithfully transferred, but the spheroidized toner is easy to roll and easily causes a cleaning failure in the cleaning device. As a cleaning member of the cleaning device, a configuration using a cleaning blade is often used because the configuration can be simplified and the cleaning performance is excellent. This cleaning blade is made of an elastic material such as polyurethane rubber, and its base end is supported by a support member, and the remaining edge is rubbed against the surface of the photoconductor as a latent image carrier to dampen the remaining toner. Drop and remove. The spheroidized toner is easy to roll between the cleaning blade and the photosensitive member without being caught by the edge of the cleaning blade. For this reason, the spherical toner is difficult to be cleaned, and an abnormal image such as a ground cover may be generated. In order to satisfactorily clean such spheroidized toner, it is conceivable to bring the cleaning blade into contact with the photoconductor with a stronger force. However, it affects the rotation or movement accuracy of the photoconductor and causes banding. Cause.

  Therefore, a method is used in which a lubricant is applied to the surface of the photoconductor to reduce the coefficient of friction on the surface of the photoconductor, thereby increasing the transfer rate at the time of transfer to reduce residual toner and reducing the cleaning burden by the cleaning blade. ing.

  Further, toner, external additives, wax, and the like may adhere (filming) to the surface of the photoreceptor due to the pressure of the cleaning blade that is rubbed against the surface of the photoreceptor. In a high humidity environment, the filming material may absorb moisture and generate an abnormal image such as image blur. In order to prevent this, it is necessary to sufficiently reduce the friction coefficient on the surface of the photoreceptor, and it is effective to apply a lubricant to the photoreceptor.

  In addition, there are a corona method and a contact or proximity charging method as a method for charging the photoconductor, but in recent years, a method using a contact or proximity charging method in which ozone is relatively difficult to generate due to the environment is increasing. In the contact or proximity charging method, a DC voltage on which an AC voltage is superimposed is applied in order to improve charging uniformity. However, when an AC voltage is superimposed, the amount of current flowing through the photosensitive member increases, so that filming on the surface of the photosensitive member is likely to occur, and the above problem becomes significant. Therefore, in a device using a charging device on which an alternating voltage is superimposed, it is more important to apply a lubricant to lower the coefficient of friction on the surface of the photoreceptor.

  As one of the lubricant application means for applying a lubricant such as zinc stearate to the surface of the photoconductor, a toner containing zinc stearate is used in the toner. What is supplied is known (for example, Patent Document 8). However, when zinc stearate is contained in the toner, there is a problem that the zinc stearate on the surface of the photoreceptor becomes non-uniform due to the pattern of the developed image.

  As another lubricant application means, a solid lubricant, a brush roller that applies the solid lubricant to the surface of the photosensitive member while being rotated, and a pressure spring that presses the solid lubricant against the brush roller are provided. Are widely used (for example, Patent Document 9). In this lubricant application means, a solid lubricant made of zinc stearate or the like is pressed against a brush roller with good abrasiveness and applicability with a pressure spring, and the solid lubricant is scraped and held near the tip of the brush roller. To do. The brush roller is fixed at a position where the vicinity of the brush tip rotates by rubbing the surface of the photoconductor, and applies a lubricant held by rubbing the surface of the photoconductor to the surface of the photoconductor.

  Further, as the lubricant application means, a device provided with the solid lubricant, a brush roller, and a pressure spring is provided, and a toner containing zinc stearate is used to remove the lubricant from both sides. What is supplied to is also known (for example, Patent Document 10).

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 2000-231298 A JP 2004-333961 A

  The amount of lubricant applied to the photoreceptor surface will be described. When the photoconductor is new, no lubricant is applied to the surface of the photoconductor, so that the coefficient of friction on the surface of the photoconductor is high. Therefore, it is necessary to apply a sufficient amount of lubricant to the surface of the photoconductor at the initial stage to sufficiently reduce the coefficient of friction of the photoconductor surface to prevent poor cleaning and filming. In addition, once a thin film of lubricant is formed on the surface of the photoreceptor, the coefficient of friction is lowered, so that poor cleaning and filming are less likely to occur. Over time, a portion of the lubricant on the surface of the photoreceptor is scraped off and decreases, so it is necessary to continue to apply the lubricant, but it is not necessary to apply the same amount as in the initial stage. When a lubricant is applied, the amount of lubricant supplied to the surface of the photoreceptor becomes excessive. If the lubricant is excessively supplied to the surface of the photoconductor, it adheres to the charging member that is in contact with or close to the photoconductor. When the lubricant adheres to the charging member, the additive or toner contained in the toner is likely to adhere to the charging member, and the charging member is significantly stained. Due to the contamination of the charging member, the surface potential of the photosensitive member becomes non-uniform, an image density difference is generated, and if it is further deteriorated, there is a possibility that background contamination will occur. Therefore, it is desirable to apply the lubricant to the surface of the photoreceptor to the minimum necessary amount.

  The present invention has been made in view of the above background, and an object thereof is to apply a lubricant on a latent image carrier in order to prevent poor cleaning and filming of the latent image carrier. An object of the present invention is to provide an image forming apparatus and a process cartridge capable of reducing contamination of a charging member due to excessive supply of a lubricant over time in an image forming apparatus provided with a coating unit.

In order to achieve the above object, the invention of claim 1 is characterized in that a latent image carrier that carries a latent image and a charging member that charges the latent image carrier by a charging member that is in contact with or close to the surface of the latent image carrier. A latent image forming apparatus for forming a latent image on the latent image carrier, a developing device for developing toner by attaching the toner to the latent image on the latent image carrier, and a toner remaining on the surface of the latent image carrier A cleaning device that cleans the surface of the latent image carrier with a cleaning blade, and a lubricant application unit that applies a lubricant to the surface of the latent image carrier. The lubricant application unit rotates the lubricant, the lubricant and the lubricant while being rotationally driven. A brush roller in contact with the surface of the latent image carrier, a pressure spring for pressing the lubricant toward the brush roller, and a spring support member for supporting the pressure spring. Scrape off the lubricant and apply to the surface of the latent image carrier In the image forming apparatus, one end on the lubricant side of the pressurizing spring is a free end, and the other end is supported by the spring support member. Initially, the pressure support spring includes the spring support member and the lubricant. When the interval between the spring support member and the lubricant is less than the free length of the pressure spring, and the volume of the lubricant is reduced over time, the free length of the pressure spring is between the spring support member and the lubricant. The spring support member is arranged so as to be longer than this.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the lubricant is disposed above a plane passing through the center of the brush roller and parallel to the installation surface of the image forming apparatus. To do.
According to a third aspect of the present invention, in the image forming apparatus of the first or second aspect, the lubricant is obtained by molding a fatty acid metal salt or fine fluorine particles.
According to a fourth aspect of the present invention, in the image forming apparatus according to the first, second, or third aspect, the lubricant is rod-shaped, and initially, the pressure spring applies the rod-shaped lubricant to a total pressurization amount of 200 mN or more. It is configured to press against the brush roller with the force of.
According to a fifth aspect of the present invention, in the image forming apparatus according to the first, second, third, or fourth aspect, a ratio of a peripheral speed of the brush roller to the latent image carrier is in a range of 0.8 to 1.2. It is characterized by being.
According to a sixth aspect of the present invention, in the image forming apparatus of the first, second, third, fourth, or fifth aspect, the toner used in the developing device has a volume average particle diameter of 3 to 8 μm and a volume average particle diameter ( The ratio (Dv / Dn) of Dv) 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 of the first, second, third, fourth or fifth aspect, the toner used in the developing device has a shape factor SF-1 in the range of 100 to 180, and the shape The coefficient SF-2 is in the range of 100 to 180.
According to an eighth aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth or fifth aspect, the toner used in the developing device is a polyester prepolymer or polyester having a functional group containing at least a nitrogen atom Further, the toner is obtained by crosslinking and / or extending reaction of 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 invention, in the image forming apparatus of the first, second, third, fourth or fifth aspect, the toner used in the developing device is substantially spherical.
According to a tenth aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, or fifth aspect, the shape of the toner used in the developing device is defined by a major axis r1, a minor axis r2, and a thickness r3. (Where r1 ≧ r2 ≧ r3), the ratio of the major axis r1 to the minor axis r2 (r2 / r1) is in the range of 0.5 to 1.0, and the thickness r3 and minor axis r2 The ratio (r3 / r2) is in the range of 0.7 to 1.0.
The invention according to claim 11 is a latent image carrier that forms a latent image, a charging device that charges the latent image carrier with a charging member that is in contact with or close to the surface of the latent image carrier, and the latent image. A process cartridge in which a cleaning device that cleans toner remaining on the surface of a carrier with a cleaning blade and a lubricant application unit that applies a lubricant to the latent image carrier are integrally supported and can be attached to and detached from the image forming apparatus main body. The lubricant applying means includes a lubricant, a brush roller that contacts the lubricant and the surface of the latent image carrier while being rotated, and a pressure spring that presses the lubricant toward the brush roller. A spring support member for supporting the pressure spring, and scraping the lubricant with the brush roller and applying the lubricant to the surface of the latent image carrier, the pressure spring being on the lubricant side. One end is a free end The other end is supported by the spring support member. Initially, the space between the spring support member and the lubricant is shorter than the free length of the pressure spring, and the volume of the lubricant over time is reduced. The spring support member is arranged so that the distance between the spring support member and the lubricant becomes longer than the free length of the pressurizing spring when it decreases due to consumption.

  In the present invention, initially, between the spring support member and the lubricant is shorter than the free length of the pressure spring, the lubricant is pressed toward the brush roller by the pressure spring in the compressed state, and the brush roller Dig deep into. As a result, the amount of lubricant scraped off by the brush roller can be increased, and even in the initial latent image carrier, a sufficient amount of lubricant is applied on the latent image carrier to reduce the friction coefficient. Can do. Further, when the bulk of the lubricant decreases with time, the free end of the pressure spring is not in contact with the lubricant because the space between the spring support member and the lubricant is longer than the free length of the pressure spring. . As a result, the lubricant is not pressed against the brush roller by the pressure spring, and the lubricant comes into contact with the brush roller without deeply intruding. Therefore, the amount of lubricant scraped off by the brush roller can be greatly reduced, and excessive supply of lubricant can be prevented. In this way, it is possible to continuously apply a necessary amount of lubricant for preventing poor cleaning and filming on the surface of the latent image carrier over the initial period and over time, and to prevent excessive supply of lubricant over time. Can do. Note that, as in the present invention, if the lubricant is consumed and the volume is reduced without the gap between the spring support member and the lubricant becoming longer than the free length of the pressure spring over time, The compression state is weakened. As a result, the amount of lubricant penetrating into the brush roller is reduced, so that the amount of application is reduced accordingly. However, according to the present invention, the amount of lubricant scraped off by the brush roller is greatly increased by arranging the spring support member so as to be longer than the free length of the pressure spring between the spring support member and the lubricant over time. The excess supply over time can be effectively prevented by reducing the amount to less.

  As described above, according to the present invention, in the image forming apparatus provided with the lubricant applying means for applying the lubricant onto the latent image carrier in order to prevent poor cleaning and filming of the latent image carrier, the lubricant over time There is an excellent effect that contamination of the charging member due to excessive supply of can be reduced.

  Hereinafter, an embodiment in which the present invention is applied to an image forming apparatus will be described. First, the configuration and operation of the image forming apparatus according to the present embodiment will be described. In this image forming apparatus, a plurality of image forming units are arranged so as to face the intermediate transfer belt, toner images of each color are formed on the latent image carrier of each image forming unit, and these toner images are transferred to the intermediate transfer belt. The toner image is transferred to form a superimposed toner image. A so-called tandem type image forming apparatus forms a color image by secondarily transferring the superimposed toner image on the intermediate transfer belt onto a transfer sheet. In this tandem type image forming apparatus, four image forming units of black, yellow, magenta, and cyan are arranged side by side so as to face a rotatable endless belt-shaped intermediate transfer belt. In addition to this image forming unit, an exposure device for forming an electrostatic latent image on the latent image carrier of each image forming unit, a secondary transfer device for secondary transfer of a toner image superimposed from an intermediate transfer belt onto a recording sheet, and secondary A sheet feeding / conveying device that feeds and conveys recording paper to the transfer area, a fixing device that fixes a toner image on the recording paper, and the like are provided. Since these constituent operations are general, the description thereof is omitted.

  Each image forming unit is formed of a photoconductor unit to be described later and each color developing device corresponding thereto. Note that the four color developing devices of black, yellow, magenta, and cyan have the same configuration and operation except for the color of the toner to be accommodated. Each photoconductor unit has the same configuration and operation except for the color of the toner collected by the cleaning device.

  Next, the photoconductor unit will be described. FIG. 1 is a schematic configuration diagram of the photoconductor unit 2. The photoconductor unit 2 includes a photoconductor 5 as a latent image carrier, a charging device 4 having a charging roller 4a for charging the surface of the photoconductor 5, and a cleaning device having a cleaning blade 15a for cleaning the surface of the photoconductor 5. 15 and a lubricant application means 17 provided with a brush roller 17a for applying a lubricant to the surface of the photoreceptor 5. The charging roller 4a is a conductive or semiconductive roller-like member that is disposed in contact with or close to the surface of the photoconductor 5. A bias obtained by superimposing an AC voltage on a DC voltage is applied to the charging roller 4a to apply a charge to the surface of the photoconductor 5 to charge the photoconductor 5. Further, in the cleaning device 15, the cleaning blade 15 a made of an elastic material is pressed against the surface of the photoconductor 5, and the residual toner on the surface of the photoconductor 1 is blocked and scraped off.

  Next, the lubricant application unit 17 that is a characteristic part of the image forming apparatus of the present embodiment will be described in detail. The lubricant application means 17 includes a lubricant molded body 17b obtained by solidifying the lubricant, a brush roller 17a that contacts the lubricant molded body 17b, scrapes the lubricant, and supplies the lubricant to the surface of the photoreceptor 5, and a brush roller 17a. The brush roller scraper 17c for removing the toner adhering to the toner, the pressure spring 17d for pressing the lubricant molding 17b against the brush roller 17a, and the spring support member 17e for supporting the pressure spring 17d. ing. The brush roller 17 a has a shape extending in the axial direction of the photosensitive member 5. The lubricant molded body 17b is formed in a rectangular parallelepiped rod shape. The pressure spring 17d has a free end on the side that presses the lubricant molded body 17b, and the other end supported by a spring support member 17e. The lubricant molded body 17b is scraped uniformly in the axial direction. The lubricant molded body 17b is urged uniformly in the axial direction to the brush roller 17a. The brush roller 17a also functions as a lubricant application member and a function of collecting toner remaining on the surface of the photoreceptor 5.

  When the photoconductor 5 of the photoconductor unit 2 is new, no lubricant is applied to the photoconductor 5, so that the friction coefficient of the surface is high. Therefore, it is necessary to apply a sufficient amount of lubricant to the surface of the photoconductor 5 in the initial stage to reduce the coefficient of friction of the photoconductor 5 to prevent poor cleaning and filming. In addition, over time, it is desirable to regulate the amount of lubricant applied to the photoreceptor 5 to a minimum amount. Therefore, as shown in FIG. 2A, initially, the spring support member 17e is arranged so that the space between the spring support member 17e and the lubricant molded body 17b is shorter than the free length of the pressure spring 17d. . As a result, the molded lubricant 17b is pressed toward the brush roller 17a by the compressed pressure spring 17d and bites deeply into the brush roller 17a. Therefore, the amount of lubricant scraped off by the brush roller 17a can be increased, and a sufficient amount of lubricant can be applied to the surface of the photoconductor 5 even in the initial photoconductor to reduce the friction coefficient.

  Further, once a thin film of lubricant is formed on the surface of the photoconductor 5 and the friction coefficient is lowered to reach a saturated state, poor cleaning and filming are less likely to occur. Therefore, as shown in FIG. 2B, when the lubricant is consumed over time and the bulk is reduced, the space between the spring support member 17e and the lubricant molded body 17b becomes longer than the free length of the pressure spring 17d. By doing so, the free end of the pressure spring 17d is not in contact with the lubricant molded body 17b. As a result, the lubricant molded body 17b is not pressed by the brush roller 17a, and the lubricant molded body 17b comes into contact with the brush roller 17a without being digged deeply. Therefore, the amount of lubricant scraped off by the brush roller 17a can be greatly reduced, and excessive supply of lubricant can be prevented.

  In this way, it is possible to continue applying a necessary amount of lubricant on the surface of the photosensitive member 5 in the initial stage and over time, and to prevent excessive supply of lubricant over time. it can.

  Further, as described above, the brush roller 17a serves as both a lubricant application member and a toner recovery means. Therefore, if toner adheres to the brush roller 17a, the application efficiency of the solid lubricant 17b to the photosensitive member 5 is improved. May fall. For this reason, unevenness occurs in the application of the lubricant on the surface of the photoconductor 5 between the portion where the toner is attached and the portion where the toner is not attached. If there is unevenness in the coefficient of friction on the surface of the photoconductor 5, the transfer rate to the transfer paper differs from the toner image on the surface of the photoconductor 5, and an image having a uniform density cannot be obtained. However, even if such a problem occurs, once a lubricant thin film is formed on the surface of the photosensitive member 5, the lubricant applying means 17 can apply the lubricant as long as the friction coefficient can be maintained even if the toner adheres to the brush roller 17a. It has been experimentally found that the toner can be supplied to the photoconductor 5.

  Further, since the lubricant thin film on the surface of the photoconductor 5 is scraped off by the cleaning blade 15a, the lubricant on the surface of the photoconductor 5 is prevented from cleaning failure and filming when the amount of the lubricant applied is extremely small. For this reason, there is a possibility that the amount of the friction coefficient necessary for the maintenance is insufficient. Accordingly, by applying pressure to the brush roller 17a by the weight of the lubricant molded body 17b in a state in which the pressing biasing force by the pressure spring 17d has disappeared over time, an amount of lubricant that is close to the minimum necessary is applied. To be done continuously. Specifically, as shown in FIG. 3, the lubricant molding 17b is arranged in a region (hatched region in the drawing) above the X axis that is parallel to the installation surface of the image forming apparatus and passes through the center of the brush roller 17a. . As a result, when the pressure biasing force by the pressurizing spring 17d disappears over time, pressure is applied to the brush roller 17a due to the weight of the lubricant molded body 17b, and the lubricant is continuously applied in a state where the supply amount is reduced. It can be performed. Therefore, it is possible to reliably and continuously apply the lubricant application amount that achieves both the cleaning failure and the prevention of filming and the charging roller contamination.

  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, dichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoropolo Fluorine-based resins such as pyrene copolymers are exemplified. In particular, a metal stearate having a large effect of reducing the friction coefficient 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. 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 surface of 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 a toner having a high degree of circularity, the toner easily rolls on the surface of the photoconductor 5, so that 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. On the other hand, when 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 surface of the photoconductor 5.

  Here, the friction coefficient of the photosensitive member 5 was measured by the Euler belt method as follows. FIG. 4 is a diagram for explaining a method of measuring the friction coefficient of the photosensitive member. In this case, medium-quality high-quality paper as a belt is stretched around the drum circumference ¼ so that the paper scraper is in the longitudinal direction, and a load 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 is pulled, and the load at the time when the belt moves is read, and the friction coefficient μs = 2 / π × 1n (F / 0.98) (where μ is the static friction coefficient, F: Measurement value) Note that the coefficient of friction of the photosensitive member 5 in the image forming apparatus 200 is a value when a steady state is obtained by image formation. This is because the coefficient of friction of the photosensitive member 5 is affected by other devices arranged in the image forming apparatus 200, 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.

  In the photoreceptor unit 2 of FIG. 1, as the molded lubricant 17b of the lubricant application means 17, a fatty acid metal salt such as zinc stearate is melted and solidified into a rod shape, or polytetrafluoroethylene or the like. A fluororesin molded into a rod shape or a sheet shape was used. Such a lubricant molded body 17b was fixed to the holding member and brought into contact with the brush roller 17a.

  The initial lubricant application amount can be appropriately adjusted by adjusting the conditions of the pressure spring 17d, the arrangement of the spring support member 17e, and the like. In the photoreceptor unit 2 of FIG. 1, the lubricant molded body 17b is pressed against the brush roller 17a by a pressure spring including its own weight with a pressure of 200 mN or more. As the pressure increases, the amount of lubricant that the brush roller 17a scrapes off from the molded lubricant 17b increases, and the amount of lubricant applied to the surface of the photoreceptor 5 increases, reducing the friction coefficient of the photoreceptor 5. be able to.

  Further, the brush roller 17a is rotated in the same direction at a portion in contact with the surface of 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 photoconductor 5. There is no need to form a lubricant film when the brush roller 17a supplies the surface of the photoconductor 5, and the lubricant supplied to the surface of the photoconductor 5 forms a lubricant film by the pressing force of the cleaning blade 15a. . Therefore, it is preferable here to rotate in the same direction in order to supply without impact.

  Furthermore, the peripheral speed ratio between the brush roller 17a and the photosensitive member 5 (photosensitive member peripheral speed / brush roller peripheral speed) 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 roller 17a to the photoconductor 5 with a small impact, it is more preferable that the ratio is in the range of 1.0 to 1.1.

  Next, the toner used in the image forming apparatus of this embodiment will be described. FIG. 5 is a schematic view showing the structure of the toner. The toner is composed of at least a binder resin and a colorant, and an external additive that imparts fluidity is externally added to the surface of the toner. In addition, a charge control agent that controls the chargeability of the toner, and a separation from the fixing device. You may contain the mold release agent etc. which improve a moldability.

  The binder resin is an ester resin, a vinyl resin, an amide resin, an epoxy resin, a silicone resin, or the like, and is particularly preferably a vinyl resin, 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 Using methyl acrylate-butyl acrylate copolymer, etc. 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%, preferably 3 to 10%, 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%, preferably from 1 to 3%, 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%, preferably 1 to 5%, 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, the cleaning blade 15a may not be sufficiently scraped by contact. This is because the toner easily rolls on the surface of 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. On the other hand, the lubricant is applied to the surface of the photoconductor 5 by the lubricant applying means 17 and the friction coefficient of the surface of the photoconductor 5 is reduced, thereby increasing the transfer rate at the time of transfer and reducing the residual toner, thereby cleaning the blade. It is possible to reduce the burden of cleaning by 15a and to perform cleaning without banding even if the cleaning blade 15a abuts 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, zircoaluminate. 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. 6A and 6B are diagrams schematically showing the shape of the toner. FIG. 6A is a diagram for explaining the shape factor SF-1, and FIG. 6B 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 on the two-dimensional plane by the figure area AREA and multiplying by 100π / 4.
SF-2 = {(PERI) 2 / AREA} × (100π / 4) (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 40.

  The shape factors SF-1 and SF-2 of the toner are preferably 100 or more. Further, when SF-1 and SF-2 are increased, the amount of the reversely charged toner T1 is increased, the toner charge amount distribution is broadened, and the load on the temporary holding device 40 is increased. For this reason, SF-1 preferably does not exceed 180, and SF-2 preferably does not exceed 180.

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

  FIG. 7 is a schematic view showing the outer shape of the toner, FIG. 7A is an appearance of the toner, and FIG. 7B is a cross-sectional view of the toner. In FIG. 7A, 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 shortest axis thickness r3. ≧ Short axis r2 ≧ Thickness r3 The toner has a major axis / minor axis ratio (r2 / r1) of 0.5 to 1.0 and a thickness / minor axis ratio (r3 / r2) of 0.7 to 1.0. It has a substantially spherical shape. When the ratio of the major axis to the minor 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 embodiment is a toner material 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. It is a toner obtained by crosslinking and / or extending the liquid 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, the toner tends to be negatively charged, and further, 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 10,000 to 400,000, 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; 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 urea-modified polyester is produced by a one-shot method or the like. Polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) are heated to 150-280 ° C. in the presence of a known esterification catalyst such as tetrabutoxytitanate, dibutyltin oxide, etc., and water generated while reducing the pressure as necessary. Distill 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 gloss when used in the full-color image forming apparatus 100 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%, 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 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. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), MegaFuck 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), SGP (manufactured by Soken), 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 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 of the isocyanate group structure of the polyester prepolymer (A) with 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.

  In addition, the above-described toner may contain a lubricant, and the lubricant may be supplied to the surface of the photoreceptor 5 from both the lubricant application unit 17 and the toner. In the image forming apparatus according to the present embodiment, as described above, the amount of lubricant supplied to the surface of the photoconductor 5 is continuously increased with a large amount at the beginning and small with time. By performing both the application from the lubricant application means 17 and the supply from the toner, it is possible to finely adjust the supply amount of the lubricant, and effectively prevent defective cleaning and filming.

  In the present embodiment, as described above, the photoconductor unit 2 in which the photoconductor 5, the charging device 4, the cleaning device 15, and the lubricant application unit 17 are integrally molded is attached to and detached from the image forming apparatus main body. It is used as a possible process cartridge. In this way, the life of the photoconductor 5 can be extended by using the photoconductor unit 2 provided with the above-described lubricant applying means 17. Further, since it takes the form of a process cartridge, when maintenance is required, the process cartridge can be replaced, and the maintainability is improved.

As described above, according to the image forming apparatus of the present embodiment, initially, the spring support member 17e is disposed so that the space between the spring support member 17e and the lubricant molded body 17b is shorter than the free length of the pressure spring 17d. To do. Accordingly, the molded lubricant 17b is pressed toward the brush roller 17a by the pressure spring 17d in a compressed state and digs deeply. Accordingly, the amount of lubricant scraped off by the brush roller 17a can be increased, and a sufficient amount of lubricant can be applied to the surface of the photoreceptor 5 even in the initial photoreceptor to reduce the friction coefficient. Further, when the lubricant is consumed over time and the bulk is reduced, the pressure spring is made longer than the free length of the pressure spring 17d between the spring support member 17e and the lubricant molding 17b. The free end of 17d is not in contact with the lubricant molded body 17b. As a result, the lubricant molded body 17b is not pressed by the brush roller 17a, and the lubricant molded body 17b comes into contact with the brush roller 17a without being digged deeply. Therefore, the amount of lubricant scraped off by the brush roller 17a can be greatly reduced, and excessive supply of lubricant can be prevented. It is possible to continuously apply a necessary amount of lubricant to the surface of the photoconductor 5 over the initial stage and over time, and to prevent excessive supply of lubricant over time.
Further, the lubricant molded body 17b is disposed above a plane that passes through the center of the brush roller 17a and is parallel to the installation surface of the image forming apparatus. Thereby, it becomes the pressurization to the brush roller 17a by the dead weight of the lubricant molding 17b, and the continuous lubricant application in a state where the supply amount is reduced can be performed.
Further, the molded lubricant 17b is formed by molding a fatty acid metal salt or fluorine fine particles, so that the effect of reducing the friction coefficient of the photoreceptor 5 can be increased.
The lubricant molding 17b is rod-shaped, and in the initial stage, the pressure spring 17d presses the rod-shaped lubricant molding 17b against the brush roller 17a with a total pressure of 200 mN or more. As a result, the coefficient of friction of the photosensitive member 5 can be reduced even in the initial stage, and cleaning failure and filming can be prevented.
Further, the ratio of the peripheral speed of the brush roller 17a to the photosensitive member 5 is set to a 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. By setting the ratio of the peripheral speeds in the range of 0.8 to 1.2, the lubricant can be supplied from the brush roller 17a to the photoreceptor 5 with a small impact.
The toner used in the developing device 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) of 1.00 to 1.n. It shall be in the range of 40. Thereby, it is possible to obtain a high-definition and high-quality image with little background fog.
Further, it is assumed that the toner used in the developing device 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. 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. In the shape factor SF-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. When the shape of the toner is close to a spherical shape, the contact state between the toner and the toner or the toner and the photoconductor becomes a point contact, so that the adsorbing force between the toners becomes weak and the fluidity increases, and the toner and the photoconductor The attraction force becomes weaker and the transfer rate becomes higher. If either of the shape factors SF-1 and SF-2 exceeds 180, the transfer rate is lowered, which is not preferable.
In addition, the toner includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, and a toner material liquid in which a colorant and a release agent are dispersed in an organic solvent. It is a toner obtained by an extension reaction. Thereby, a high quality image can be obtained.
In addition, since the toner has a substantially spherical shape, a high-quality image can be obtained.
The shape of the toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), and the ratio of the major axis r1 to the minor axis r2 (r2 / r1) is 0. It is assumed that the ratio (r3 / r2) between the thickness r3 and the minor axis r2 is in the range of 0.7 to 1.0. Thereby, a high quality image can be obtained.
In addition, the photosensitive member 5, the charging roller 4 in contact with or close to the photosensitive member 5, the cleaning blade 15a, and the lubricant applying unit 17 are integrally supported, and the process cartridge is detachable from the main body of the image forming apparatus. . Thereby, maintainability improves.

FIG. 2 is a schematic configuration diagram of a photoreceptor unit employed in the image forming apparatus of the present embodiment. It is a figure which shows the state of a lubricant molding and a pressurization spring, FIG. 2 (a) is an initial stage, FIG.2 (b) is a conceptual diagram of time passage. Explanatory drawing of the position which arrange | positions a lubricant molding. Explanatory drawing of the measuring method of the friction coefficient of a photoreceptor. FIG. 3 is a schematic diagram illustrating a configuration of toner. FIGS. 6A and 6B are diagrams schematically illustrating the shape of the toner, in which FIG. 6A illustrates the shape factor SF-1, and FIG. 6B illustrates the shape factor SF-2. FIGS. 7A and 7B are schematic views illustrating an outer shape of a toner, FIG. 7A is an external view of the toner, and FIG. 7B is a cross-sectional view of the toner.

Explanation of symbols

2 Photosensitive unit 5 Photoconductor 14 Charging device 14a Charging roller 14b Charging roller cleaning brush 15 Cleaning means 15a Cleaning blade 15b Blade pressure spring 15c Blade rotation fulcrum 15d Waste toner collection coil 17 Lubricant application means 17a Brush roller 17b Lubricant Molded body 17c Brush roller scraper 17d Pressure spring 17e Spring support member

Claims (11)

A latent image carrier that carries a latent image, a charging device that charges the latent image carrier by a charging member that is in contact with or close to the surface of the latent image carrier, and a latent image that forms a latent image on the latent image carrier. An image forming apparatus, a developing device that attaches toner to the latent image of the latent image carrier and develops it, a cleaning device that cleans toner remaining on the surface of the latent image carrier with a cleaning blade, and the latent image carrier A lubricant application means for applying a lubricant to the surface, the lubricant application means being in contact with the lubricant and the surface of the latent image carrier while being rotationally driven, and the lubricant A pressure spring for pressing the agent toward the brush roller, and a spring support member for supporting the pressure spring. The brush roller scrapes off the lubricant and applies it to the surface of the latent image carrier. In the image forming apparatus,
The pressure spring has one end on the lubricant side being a free end and the other end supported by the spring support member. Initially, the pressure spring is between the spring support member and the lubricant. And when the volume of the lubricant is reduced by consumption over time, the space between the spring support member and the lubricant is longer than the free length of the pressure spring. An image forming apparatus comprising the spring support member.   The image forming apparatus according to claim 1, wherein the lubricant is disposed above a plane that is parallel to an installation surface of the image forming apparatus and passes through a center of the brush roller.   3. The image forming apparatus according to claim 1, wherein the lubricant is formed by molding a fatty acid metal salt or fluorine fine particles.   4. The image forming apparatus according to claim 1, wherein the lubricant is rod-shaped, and initially, the pressure spring presses the rod-shaped lubricant against the brush roller with a force of a total pressurization amount of 200 mN or more. An image forming apparatus configured as described above.   5. The image forming apparatus according to claim 1, wherein a ratio of a peripheral speed of the brush roller to the latent image carrier is in a range of 0.8 to 1.2. .   6. The image forming apparatus according to claim 1, wherein the toner used in the developing device has a volume average particle diameter of 3 to 8 μm, a volume average particle diameter (Dv) and a number average particle diameter (Dn). ) (Dv / Dn) is in the range of 1.00 to 1.40.     6. The image forming apparatus according to claim 1, wherein the toner used in the developing device 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. An image forming apparatus characterized by being in a range.   6. The image forming apparatus according to claim 1, wherein the toner used in the developing device includes at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. An image forming apparatus, which is a toner obtained by crosslinking and / or stretching reaction of a toner material liquid dispersed in an organic solvent in an aqueous medium.   6. The image forming apparatus according to claim 1, wherein the toner used in the developing device has a substantially spherical shape.   6. The image forming apparatus according to claim 1, wherein the toner used in the developing device is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≧ r2 ≧ r3). The ratio (r2 / r1) between the major axis r1 and the minor axis r2 is in the range of 0.5 to 1.0, and the ratio (r3 / r2) between the thickness r3 and the minor axis r2 is 0. An image forming apparatus in the range of .7 to 1.0. A latent image carrier that forms a latent image, a charging device that charges the latent image carrier with a charging member that is in contact with or close to the surface of the latent image carrier, and cleaning toner remaining on the surface of the latent image carrier In a process cartridge in which a cleaning device for cleaning with a blade and a lubricant application means for applying a lubricant to the latent image carrier are integrally supported and detachable from the image forming apparatus main body,
The lubricant application means comprises a lubricant, a brush roller that contacts the lubricant and the surface of the latent image carrier while being rotated, a pressure spring that presses the lubricant toward the brush roller, A spring support member for supporting the pressure spring, scraping the lubricant with the brush roller and applying it to the surface of the latent image carrier, and the pressure spring has one end on the lubricant side. It is a free end, and the other end is supported by the spring support member. Initially, the space between the spring support member and the lubricant is shorter than the free length of the pressure spring, and the The spring support member is arranged so that the space between the spring support member and the lubricant becomes longer than the free length of the pressure spring when the volume of the lubricant decreases due to consumption. Process cartridge.

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