JP4350452B2 - Cleaning blade, cleaning device, process cartridge, image forming device - Google Patents

Description

  The present invention relates to a cleaning blade of a cleaning device mounted on an image forming apparatus using an electrophotographic process such as a copying machine, a printer, and a facsimile machine. The present invention also relates to a cleaning device including the cleaning blade, a process cartridge and an image forming device including the cleaning device, and further to a toner suitably used for the image forming device.

An image forming apparatus using an electrophotographic process includes a photosensitive member as a latent image carrier, charges the surface of the photosensitive member by discharging, charges the surface of the photosensitive member to form an electrostatic latent image, The electrostatic latent image is supplied with toner to be visualized, and the formed visible image on the surface of the photoreceptor is transferred onto the transfer paper surface, and then fixed and discharged.
In recent years, there has been an increasing demand for higher image quality, and in order to realize particularly high-definition color image formation, toner particles are being made smaller and spherical. The reproducibility of dots is improved by reducing the particle size, and the developability and transferability can be improved by making the particles spherical. Since it is very difficult to produce such a small particle size and spherical toner by the conventional kneading and pulverization method, the polymerization produced by suspension polymerization method, emulsion polymerization method, dispersion polymerization method, etc. Toner is being adopted.

However, when a toner having a spherical shape and a reduced particle size is used, there are some problems in cleaning on the photoreceptor after image formation.
One of them is that it is difficult to clean the toner remaining untransferred on the photosensitive member by a blade cleaning method that is generally used. The cleaning blade removes toner while rubbing the surface of the photoconductor, but the edge portion of the cleaning blade is deformed due to frictional resistance with the photoconductor, so that a minute space is generated between the photoconductor and the cleaning blade. The smaller the toner particle size, the easier it is to enter this space. Since the rolling friction force is smaller as the invading toner has a shape close to a spherical shape, it starts to roll in the space between the photosensitive member and the cleaning blade, passes through the cleaning blade, and leads to poor cleaning.
With respect to such a problem, a method for deforming a small particle size toner has been proposed. For example, the polymer after suspension polymerization is heated above the glass transition point in a dispersion medium to obtain aggregated particles. The aggregated particles are introduced into a heated jet stream, and the aggregated particles are crushed and simultaneously dried. Thus, a method for obtaining an irregularly shaped small particle size toner (see, for example, Patent Document 1), a binder resin and a colorant are mixed in a solvent immiscible with water, and in an aqueous medium in the presence of a dispersion stabilizer. And a solvent is removed from the resulting suspension by heating and / or decompression to obtain toner particles having irregularities on the surface (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 5-188642 JP 9-15903 A

The other is that wax added to improve the releasability added internally or externally to the toner, inorganic fine particles for improving fluidity, etc. are detached from the toner and adhere to the photoreceptor. That's what it means. As the toner becomes smaller in particle size, the content ratio of these additives in the toner becomes higher than that in the conventional toner, so that the amount of adhered substances on the photosensitive member tends to increase.
In addition, since such additives have a much smaller particle size than toner, it is difficult to remove them completely by conventional blade cleaning. The adhered substance that is not removed causes thin filming if it is mainly composed of wax, and if it is composed mainly of inorganic fine particles, it becomes the core, and calcium carbonate contained in the recording paper. It grows with additives such as the like, and will adversely affect the image over time.

  As means for removing adhered substances on the photoconductor, a method using a cleaning blade having a function of polishing the surface of the photoconductor as described below has been proposed. For example, a cleaning blade (see Patent Document 3) coated with a high-hardness material such as amorphous carbon or amorphous silicon on the edge of the blade, or a cleaning blade (see Patent Document 4) in which an abrasive is adhered to the edge of the blade. Etc. However, the former requires a large-scale device for coating the blade edge, and the latter has a cleaning function for a long time because the abrasive is easily peeled off in the configuration in which the abrasive is adhered to the blade edge. Difficult to maintain.

JP-A-6-282206 JP 2001-296781 A

  In view of the above problems, an object of the present invention is to provide a cleaning blade having a function of removing adhered substances on the surface of a photoreceptor or the like with a simple configuration. Also, provided is a cleaning device equipped with the cleaning blade and capable of maintaining a good cleaning performance of the surface of a photoreceptor or the like for a long period of time even in an image forming process using a spherical and small particle size toner. The task is to do. It is another object of the present invention to provide a process cartridge that includes the cleaning device and does not cause deterioration in image quality over a long period of time, and an image forming apparatus.

In order to solve the above problems, the present invention is characterized by the following.
1. The present invention is a cleaning blade that abuts on a surface moving body and removes deposits on the surface moving body, the cleaning blade comprising a first abrasive member containing an elastic material and abrasive particles; A multilayer structure including at least a second polishing member made of a material having a Young's modulus of 1 GPa or more, and a second polishing member is provided on the contact surface side with the surface moving body, and the first polishing member and the second polishing member It is a cleaning blade provided so that both edges of the polishing member are in contact with the surface moving body .

2. In the cleaning blade, the second polishing member is made of resin.
3. In the cleaning blade, the second polishing member is made of a biaxially stretched polyester film.
4). In the cleaning blade, the polyester film has a thickness of 0.01 to 1.0 mm.

5. In the cleaning blade, the second polishing member is made of a metal plate.
6). In the cleaning blade, the thickness of the metal plate is 0.01 to 0.5 mm.

7). In the cleaning blade, a gap forming member is provided between the first polishing member and the second polishing member.

8). In the cleaning blade, the first polishing member has a rubber hardness of 60 to 85 degrees.
9. The cleaning blade has an apparent rubber hardness of 80 to 100 degrees.

10. The present invention also provides a cleaning device for cleaning the surface of a surface moving body that moves inside the image forming apparatus while carrying a toner or a recording member from the upstream side of the moving direction of the surface moving body. A cleaning device in which a first cleaning blade and a second cleaning blade are arranged in order, and the second cleaning blade is any one of the cleaning blades.
11. In the cleaning device, the first cleaning blade contacts the surface moving body by a counter method, and the second cleaning blade contacts the surface moving body by a trailing method.
12 In the cleaning device, the contact angle of the second cleaning blade is 5 to 25 degrees.
13 In the cleaning device, the contact pressure of the second cleaning blade is 10 to 80 gf / cm.

14 The present invention also provides a process cartridge that is integrally supported and includes an image carrier and a cleaning unit that cleans the surface of the image carrier, and is detachably formed on the image forming apparatus main body. A process cartridge including any one of the above-described cleaning devices as a cleaning unit.

15. The present invention also provides an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and the surface of the charged image carrier that is exposed based on image data and writes the latent image. Image formation comprising exposure means, developing means for supplying toner to the latent image formed on the surface of the image carrier to make it visible, and transfer means for transferring the visible image on the surface of the image carrier to a recording member In the apparatus, the image forming apparatus is an image forming apparatus including any one of the cleaning devices as means for cleaning the surface of the image carrier.

16. The present invention also provides an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and the surface of the charged image carrier that is exposed based on image data and writes the latent image. An exposure unit, a developing unit that supplies toner to the latent image formed on the surface of the image carrier and visualizes it, and a visible image on the surface of the image carrier is temporarily transferred to the intermediate transfer member, and then the intermediate transfer member The image forming apparatus includes a transfer unit that transfers the visible image held by the recording member to the recording member. The image forming apparatus includes any one of the cleaning devices as a unit that cleans the surface of the intermediate transfer member. It is.

17. The present invention also provides an image carrier that carries a latent image, a charging unit that uniformly charges the surface of the image carrier, and the surface of the charged image carrier that is exposed based on image data and writes the latent image. An exposure unit, a developing unit that supplies toner to the latent image formed on the surface of the image carrier and visualizes the image, a transfer unit that transfers the visible image on the surface of the image carrier to a recording member, and the vicinity of the transfer position An image forming apparatus including a recording member support that conveys the recording member while supporting the recording member, and the image forming apparatus includes any one of the cleaning devices as means for cleaning the surface of the recording member support. It is.

18. In the image forming apparatus, the volume average particle size of the toner used in the developing unit is 3 to 8 μm, and the ratio (Dv / Dn) of the volume average particle size (Dv) to the number average particle size (Dn) is 1. It exists in the range of 00-1.40.
19. In the image forming apparatus, the toner used in the developing unit is 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. The toner is obtained by crosslinking and / or elongation reaction in an aqueous medium.
20. In the image forming apparatus, the toner used in the developing means, the shape factor SF-1 is in the range of 100 to 180, a shape factor SF-2 of you being in the range of 100 to 180.

21. In the image forming apparatus, the toner used in the developing unit has a substantially spherical shape, and the shape is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that 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 ratio of the thickness r3 to the minor axis r2 (r3 / r2) is 0.7 to 1. .. in the range of .0.

  Although the cleaning blade of the present invention has a simple configuration, it has a sufficient polishing power for the surface to be polished, and can efficiently remove adhered substances adhering to a surface moving body such as a photoreceptor. By providing a cleaning device equipped with such a cleaning blade, it is possible to provide good cleaning performance for the surface of a photoconductor and the like for a long time even in an image forming process using a sphere-shaped and small-sized toner. Can be maintained throughout. As a result, the image is not contaminated or deteriorated.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing the configuration of an image forming apparatus equipped with a cleaning device of the present invention as a cleaning means for the surface of an image carrier that carries a latent image. FIG. 2 is a schematic view showing the configuration around the image carrier of the image forming apparatus equipped with the cleaning device of the present invention.
A charging device 2, an exposure device 3, a developing device 4, a transfer device 6, a fixing device 7 and a cleaning device 8 are arranged around the photoreceptor 1 as an image carrier.

The photoreceptor 1 can be made of an amorphous metal having photoconductivity, an amorphous metal such as amorphous selenium, or an organic compound such as a bisazo pigment or a phthalocyanine pigment. In consideration of the environment and post-treatment after use, it is preferable to use a photoreceptor made of an organic compound.
The charging device 2 may be any one of a corona method, a roller method, a brush method, and a blade method. Here, the charging device 2 of a roller method is shown. The charging device 2 includes a charging roller 2a, a cleaning pad 2b in contact with the charging roller 2a for cleaning, and a power supply (not shown) connected to the charging roller 2a. A high voltage is applied to the charging roller 2a, a predetermined voltage is applied between the charging roller 2a having a curvature and the photoconductor 1, and a corona discharge is generated between the photoconductor 1 and the surface of the photoconductor 1 Are uniformly charged.

The exposure device 3 converts data read by a scanner in the reading device 20 and an image signal sent from the outside such as a PC (not shown), scans the laser beam 3a with a polygon motor, and reads the image signal read through the mirror. Based on this, an electrostatic latent image is formed on the photoreceptor 1.
The developing device 4 includes a developer carrier 4a that carries a developer and supplies the developer 1 to the photoreceptor 1, a toner supply chamber, and the like. It has a cylindrical developer carrier 4a arranged at a minute distance from the photosensitive member 1, and a developer regulating member for regulating the amount of developer on the developer carrier 4a. The developer carrier 4a includes a hollow cylindrical developer carrier 4a that is rotatably supported, and a magnet roll fixed coaxially with the developer carrier 4a. The developer is magnetically attracted to the outer peripheral surface of the carrier 4a and conveyed. The developer carrier 4a is electrically conductive and is made of a nonmagnetic member, and is connected to a power source for applying a developing bias. A voltage is applied from the power source between the developer carrying member 4a and the photoreceptor 1, and an electric field is formed in the developing region.

  The transfer device 6 includes a transfer belt 6a, a transfer bias roller 6b, and a tension roller 6c. The transfer bias roller 6b is configured by providing an elastic layer on the surface of a core metal such as iron, aluminum, and stainless steel. The transfer bias roller 6 b is applied with a necessary pressure on the photosensitive member 1 side in order to bring the recording paper into close contact with the photosensitive member 1. The transfer belt 6a can obtain an effect by selecting various heat-resistant materials as a base material, and can be composed of, for example, a seamless polyimide film. A configuration in which a fluororesin layer is provided on the outside can be employed. Further, if necessary, a silicone rubber layer may be provided on the polyimide film, and a fluororesin layer may be provided thereon. Inside the transfer belt 6a, a tension roller 6c is provided to drive and stretch the transfer belt 6a.

  The fixing device 7 includes a fixing roller having a heater that is a heating unit such as a halogen lamp, and a pressure roller that is in pressure contact. In the fixing roller, an elastic layer such as silicone rubber is provided on the surface of the core metal to a thickness of 100 to 500 μm, preferably 400 μm, and for the purpose of preventing adhesion due to toner viscosity, a resin surface layer having good releasability such as fluororesin Is formed. The resin surface layer is composed of a PFA tube or the like, and its thickness is preferably about 10 to 50 μm in consideration of mechanical deterioration. A temperature detecting means is provided on the outer peripheral surface of the fixing roller, and the heater is controlled so as to keep the surface temperature of the fixing roller substantially constant within a range of about 160 to 200 ° C. In the pressure roller, the core metal surface is coated with an anti-offset layer such as tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) or polytetrafluoroethylene (PTFE). Similar to the fixing roller, an elastic layer such as silicone rubber may be provided on the surface of the core metal.

Next, a cleaning device including a cleaning blade having a polishing function for the surface of the photoreceptor 1, which is a feature of the present invention, will be described in detail. The cleaning device 8 has two blades, a first cleaning blade 8a and a second cleaning blade 8b, in order from the upstream side in the rotation direction of the photosensitive member 1 as cleaning means. Further, a toner collection blade 8d that collects the cleaned toner and a collection coil 8c that conveys the toner are provided. Further, a toner collection box (not shown) is provided.
The first cleaning blade 8a is made of a material such as metal, resin, rubber, etc., and rubbers such as fluorine rubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber, and urethane rubber are preferably used, and among these, urethane rubber is particularly preferable. . The first cleaning blade 8a mainly removes toner remaining on the photoreceptor 1 after the transfer process.

  The second cleaning blade 8 b is a cleaning blade having a polishing function for the surface of the photoreceptor 1. The configuration of the second cleaning blade 8b is shown in FIG. The second cleaning blade 8 b has a multilayer structure including at least a first polishing member 81 and a second polishing member 82. Then, it is affixed to the support member 85 and attached to the cleaning device. In addition to the untransferred toner, inorganic fine particles detached from the toner, additives such as exuded wax, or additives such as calcium carbonate contained in recording paper dust adhere to the photoreceptor 1. These substances cause filming and eventually grow from nuclei to lumps. The second cleaning blade 8b is a polishing blade that scrapes and removes the adhering substances on the photosensitive member 1.

  The first polishing member 81 is made of an elastic material containing abrasive particles. Examples of the elastic material include fluorine rubber, silicone rubber, butyl rubber, butadiene rubber, isoprene rubber, and urethane rubber. Among these, urethane rubber is particularly preferable from the viewpoint of wear resistance. As abrasive particles, nitrides such as silicon nitride, silicates such as aluminum silicate, magnesium silicate, mica and calcium silicate, calcareous substances such as calcium carbonate and gypsum, silicon carbide, boron carbide, tantalum carbide, titanium carbide, carbonized Examples thereof include carbides such as aluminum and zirconium carbide, and oxides such as cerium oxide, chromium oxide, titanium oxide, and aluminum oxide. Among these, cerium oxide having excellent polishing power is preferable.

The content of abrasive particles contained in the first polishing member 81 is preferably 0.5 wt% or more and 50 wt% or less. If the content of the abrasive particles is less than 0.5 wt%, the amount of abrasive particles that come into contact with the surface of the photoconductor 1 to exhibit the polishing effect is too small, and the adhered substances on the photoconductor 1 can be sufficiently removed. Can not. On the other hand, when the content of the abrasive particles exceeds 50 wt%, the concentration of the abrasive particles becomes too high, and molding becomes difficult. In addition, the cost increases.
The first polishing member 81 is manufactured by mixing an elastic material and abrasive particles, forming the sheet by centrifugal molding, and cutting the sheet. The first polishing member 81 manufactured in this way has an inclination in the volume occupancy of the abrasive particles, and the abrasive particle rich layer 81a having the volume occupancy of the abrasive particles of 50% or more is the photoreceptor. The 2nd cleaning blade 8b is comprised in the form contact | abutted to 1 surface. The abrasive particle rich layer 81 a preferably has a thickness of 5 μm or more and 100 μm or less in the thickness direction of the first polishing member 81. When the thickness of the abrasive particle rich layer 81a is less than 5 μm, the amount of abrasive particles that come into contact with the surface of the photoconductor 1 to exhibit the polishing effect is too small, and the adhered substances on the photoconductor 1 are sufficiently removed. I can't. On the other hand, when the thickness of the abrasive particle rich layer 81a exceeds 100 μm, the elasticity of the first polishing member 81 is affected, and the blade edge is likely to be chipped. The thickness of the abrasive particle rich layer 81a can be adjusted by adjusting the content of the abrasive particles.

The second polishing member 82 is made of a material having a Young's modulus of 1 GPa or more. As such a material, specifically, a metal such as stainless steel or a resin film having rigidity can be used. Among the resin films, polyester films represented by biaxially stretched polyethylene terephthalate are preferable. As a commercially available polyester film, Mylar (registered trademark) manufactured by DuPont is preferably mentioned. This is because the polyester film has a Young's modulus of 3 to 5 GPa and can suppress the deflection of the first polishing member 81 made of an elastic material.
The value of Young's modulus can be measured according to the standard of ASTM D882.

  The thickness of the second polishing member 82 is preferably 0.01 to 1.0 mm for the polyester film, and 0.01 to 0.5 mm for the metal plate. If the polyester film or metal plate is thinner than 0.01 mm, the intended rigidity cannot be obtained sufficiently, and as will be described later, the deflection of the first polishing member 81 cannot be suppressed and the polishing power is improved. I can't let you. Therefore, a certain thickness or more is required. However, if the thickness is too large, the rigidity will increase too much and it will be difficult to uniformly contact the photoreceptor 1.

The second cleaning blade 8b is formed by bonding the first polishing member 81 and the second polishing member 82 with a commonly used adhesive or double-sided tape. At this time, as shown in FIG. 3, the abrasive particle rich layer 81 a of the first polishing member 81 is on the side in contact with the surface to be polished, and the second polishing member 82 is more polished than the first polishing member 81. So that it comes into contact with
Moreover, it is preferable to form both the edges or surfaces of the first polishing member 81 and the second polishing member 82 so as to be in contact with the surface to be polished. For example, as shown in FIG. 3, the total length L2 of the second polishing member 82 is shorter than the total length L1 of the first polishing member 81 in consideration of the angle at which the second cleaning blade 8b contacts the surface to be polished. And the like.

FIG. 4 is a view showing a state when the second cleaning blade 8b having the configuration shown in FIG. The second cleaning blade 8b having the above configuration supplements the rubber hardness of the first polishing member 81 made of an elastic material by the highly rigid second polishing member 82 having a Young's modulus of 1 GPa or more, so that the apparent rubber hardness is high. It can be a high blade. As a result, it is possible to prevent the deflection that occurs when the blade constituted only by the first polishing member 81 is pressed against the surface of the photoreceptor 1 and to improve the polishing force by increasing the linear pressure on the surface of the photoreceptor 1. it can. Further, by adopting a configuration in which both edges or surfaces of the first polishing member 81 and the second polishing member 82 are in contact with the surface of the photoreceptor 1, the polishing power and rigidity of the first polishing member 81 containing abrasive particles are increased. The high polishing power of the second polishing member 82 is combined, and it is possible to cope with the removal of adhering substances having various shapes and properties. In particular, when the second polishing member 82 rubs the surface to be polished, even if the adhered substance is large and hard, it can be peeled off from the surface to be polished.
Further, by bringing the second polishing member 82 into contact with the surface to be polished, the entire second cleaning blade 8b has an effect of reducing the frictional force acting on the surface to be polished. It is also possible to suppress the turning-up of the blade that occurs when the moving direction of the surface to be polished changes, such as when the photosensitive member 1 is reversed.

The rubber hardness of the first polishing member 81 is preferably 60 to 85 degrees. If the hardness is less than 60 degrees, wear of the contact portion of the first polishing member 81 is accelerated, which is not preferable. Further, if the hardness is greater than 85 degrees, the edge of the first polishing member 81 tends to be chipped, which is not preferable.
When the rubber hardness of the first polishing member 81 is in the above range, the apparent rubber hardness of the second cleaning blade is higher due to the rigidity of the second polishing member 82, but the value of the apparent rubber hardness is 80 It is preferably ˜100 degrees. When the apparent rubber hardness is in this range, it is possible to obtain a sufficient polishing force for the surface to be polished, and to remove the adhered substances more efficiently. If the apparent rubber hardness exceeds 100 degrees, the amount of film scraping on the polished surface increases, which is not preferable.
The apparent rubber hardness can be measured according to a normal rubber material hardness test method. In this case, the test piece is set so that the surface of the second polishing member 82 faces up.

FIG. 5 is a diagram showing another configuration of the second cleaning blade 8b. The configurations of the first polishing member 81 and the second polishing member 82 are as described above. In this configuration, a gap forming member 83 is provided between the first polishing member 81 and the second polishing member 82. The gap forming member 83 is a member that forms a gap S between a position where the first polishing member 81 contacts the surface of the photoreceptor 1 and a position where the second polishing member 82 contacts the surface of the photoreceptor 1. The gap forming member 83 is not particularly limited in material. For example, a sponge may be used to bond the first polishing member 81 and the second polishing member 82, or a double-sided tape used to bond the first polishing member 81 and the second polishing member 82 may serve as this. You may do it.
As shown in FIG. 5, by providing the gap forming member 83, both edges of the first polishing member 81 and the second polishing member 82 can be brought into contact with the surface of the photoconductor 1 with certainty. improves. Further, the shavings by the first polishing member 81 and the second polishing member 82 can be collected in the gap S when the photosensitive member 1 is rotated reversely after the image forming process is completed. As a result, no shaving powder remains on the photosensitive member 1 that has passed through the cleaning process, which also prevents the surface of the charging roller 2a from being soiled.
The thickness of the gap forming member 83 is preferably 0.1 mm or more from the viewpoint of collecting and holding the shaving powder as described above. On the other hand, if it is too thick, it becomes impossible to hold the powder by spilling spilling or the like during normal rotation of the photoreceptor 1, so that the thickness is preferably 2.0 mm or less.

In the cleaning apparatus of the present invention shown in FIG. 2, the first cleaning blade 8a is preferably mounted so as to contact the photoreceptor 1 by a counter method, and the second cleaning blade 8b is contacted by a trailing method.
The first cleaning blade mainly serves to remove toner remaining on the photoreceptor 1 after the transfer process, and can efficiently remove toner by contacting the photoreceptor 1 in a counter manner. it can.
The second cleaning blade 8b contacts the photoconductor 1 by the trailing method, so that the adhering substance removing ability on the photoconductor 1 is slightly lowered as compared with the counter method. However, since there is almost no toner input to the second cleaning blade 8b, the blade is likely to be turned over, and this is avoided by contacting with the trailing method.

  At this time, the contact angle of the second cleaning blade 8b is preferably 5 to 25 degrees. If the contact angle of the second cleaning blade 8b is less than 5 degrees, the blade becomes bumpy and the polishing function cannot be exhibited over time due to the creep phenomenon. On the other hand, when the angle exceeds 25 degrees, the blade is turned over due to the reverse rotation of the photoreceptor 1 at the end of the job.

  The contact pressure of the second cleaning blade 8b is preferably 10 to 80 gf / cm. When the contact pressure of the second cleaning blade 8b is less than 10 gf / cm, the contact pressure is low, so that the adhering substance on the photoconductor 1 easily slips through the second cleaning blade 8b and cannot be sufficiently removed. On the other hand, if it exceeds 80 gf / cm, the film scraping amount of the photosensitive member 1 increases and the life of the photosensitive member 1 is shortened.

  The cleaning device 8 of the present invention described above includes a photosensitive member and an arbitrary means selected from a charging means and a developing means, and is integrally supported, and is a process cartridge formed detachably on the image forming apparatus main body. can do. A process cartridge that maintains the cleaning function on the photosensitive member for a long period of time and does not cause deterioration in image quality even in an image forming process in which development using a small particle size toner is performed by the process cartridge. can do.

The cleaning device of the present invention is not only used as a cleaning unit for the surface of the photosensitive member 1 but also in an image forming apparatus, and an intermediate transfer member whose surface moves while carrying a recording member such as toner or recording paper. It can also be used as a means for cleaning the surface of a belt or the like.
FIG. 6 is a schematic view showing another configuration of the image forming apparatus equipped with the cleaning device of the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
In the copying apparatus main body 100, a tandem image in which four image forming units 18 each having an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around the photosensitive member 1 as an image carrier. A forming device is provided. Above the tandem type image forming apparatus, there is provided an exposure device 21 that exposes the photoreceptor 1 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoconductor 1 of the tandem type image forming apparatus. A primary transfer unit 62 that transfers the toner images of the respective colors formed on the photoconductor 1 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 1 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto the recording paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred to a recording sheet. The secondary transfer belt 24 is a transfer transport belt that also serves as a paper transport. A fixing device 25 for fixing the image on the recording paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
Furthermore, a reversing device 28 for reversing the recording paper to record images on both sides of the recording paper is provided below the secondary transfer device 22 and the fixing device 25.

  The intermediate transfer belt 10 includes a cleaning device 17 that cleans the belt surface downstream of the transfer position to the recording paper in the belt moving direction. The configuration of the cleaning device 17 is the same as that of the photosensitive member cleaning device 8 described above, and is omitted. As a matter of course, it may be provided as a cleaning device for the photoreceptor 1, and the configuration of the cleaning device of the present invention can be applied to the cleaning device 19 for the secondary transfer belt 24. By mounting the cleaning device of the present invention, it is possible to effectively clean not only the photoconductor but also the toner and the adhering substances adhering to the surface of the intermediate transfer member or the secondary transfer belt. Further, since the cleaning performance is maintained over a long period of time, it is possible to prevent image contamination and image deterioration.

In particular, in the image forming apparatus that can achieve the effect of mounting the cleaning device of the present invention, the toner used in the developing device 4 has a volume average particle diameter of 3 to 8 μm, and the volume average particle diameter (Dv) and number This is a case where the ratio (Dv / Dn) to the average particle size (Dn) is a small particle size in the range of 1.00 to 1.40 and the particle size distribution is narrow.
By using a toner having a small particle diameter, the toner can be densely attached to the latent image. However, when the volume average particle size is smaller than the range of the present invention, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during a long period of stirring in the developing device, and the charging ability of the magnetic carrier is reduced. When used as a developer, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. On the contrary, when the volume average particle diameter of the toner is larger than the range of the present invention, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed. In many cases, the variation in toner particle size becomes large.
Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. However, it is not preferable that Dv / Dn exceeds 1.40 because the charge amount distribution becomes wide and the resolving power decreases.
The average particle size and particle size distribution of the toner can be measured using a Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). In the present invention, a Coulter counter TA-II type was used and connected to an interface (manufactured by Nikka Giken Co., Ltd.) and a personal computer (PC9801: manufactured by NEC Corporation) for outputting the number distribution and volume distribution.

  In the toner as described above, the ratio of the wax added to the toner to improve the releasability or the inorganic fine particles to improve the fluidity is small in the particle size. As a result, it is higher than the conventional toner. These additives are the cause of the adhered substances generated on the photoreceptor 1. Therefore, the cleaning device of the present invention removes the transfer residual toner and paper dust on the photosensitive member 1 with the first cleaning blade 8a, and the photosensitive material mainly composed of wax and inorganic fine particles with the second cleaning blade 8b on the downstream side. The adhered substance on the body 1 can be removed by scraping. Further, toner, paper dust, etc. leaking from the first cleaning blade 8a can be removed by the second cleaning blade 8b. The second cleaning blade 8b has a multilayer structure including at least a first polishing member 8a in which abrasive particles are contained in an elastic material and a second polishing member 8b made of a material having a Young's modulus of 1 GPa or more. Therefore, the polishing power of the photosensitive member 1 can be improved, and the problems that occur when using a toner having a small particle diameter as described above can be sufficiently solved.

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

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

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

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

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

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

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

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

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

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).
The molecular weight of the polymer produced can be measured using gel permeation chromatography (GPC) with THF as a solvent.

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

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

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

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

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

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

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × ¹⁰ -3 ~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 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 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 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).

As the cationic surfactants, aliphatic primary to have a fluoroalkyl group, 2 primary or secondary amine acids, aliphatic quaternary ammonium, such as perfluoroalkyl (C6-C10) sulfonamide propyl trimethyl ammonium salt 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), 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 between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

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

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

In addition, the toner according to the present invention has preferable ranges for the values of the shape factors SF-1 and SF-2 as follows. FIG. 7 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and 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) Expression (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.

  The toner according to the present invention is a toner having SF-1 in the range of 100 to 180 and SF-2 in the range of 100 to 180. When the shape of the toner is close to a spherical shape, the contact between the toner and the toner or the toner and the photoreceptor 1 is close to a point contact, so that the adsorbing force between the toners is weakened and the fluidity is increased. The attracting force with the body 1 is also weakened, and the transfer rate is increased. On the other hand, since the spherical toner easily enters the gap between the first cleaning blade 8a and the photosensitive member 1, the toner shape factor SF-1 or SF-2 is preferably large to some extent. Further, when SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. For this reason, it is preferable that SF-1 and SF-2 do not exceed 180.

Further, the toner according to the present invention has a substantially spherical shape and can be represented by the following shape rule.
FIG. 8 is a diagram schematically showing the shape of the toner according to the present invention. In FIG. 8, when a substantially spherical toner is defined by a major axis r1, a minor axis r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner of the present invention has a major axis and a minor axis. Ratio (r2 / r1) (see FIG. 8B) is 0.5 to 1.0, and the ratio of thickness to minor axis (r3 / r2) (see FIG. 8C) is 0.7 to 1.0. It is preferable to be in the range of 1.0. When the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior because of being away from the true spherical shape, and high quality image quality cannot be obtained. On the other hand, if the ratio of thickness to minor axis (r3 / r2) is less than 0.7, the shape is close to a flat shape, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio of the thickness to the minor axis (r3 / r2) is 1.0, the rotating body has a major axis as a rotation axis, and the fluidity of the toner can be improved.
Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.

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

FIG. 2 is a schematic view showing a configuration of an image forming apparatus equipped with a cleaning device of the present invention as a cleaning unit for the surface of an image carrier that carries a latent image. 1 is a schematic view showing a configuration around an image carrier of an image forming apparatus equipped with a cleaning device of the present invention. It is a figure which shows the structure of a 2nd cleaning blade. FIG. 4 is a diagram showing a state when a second cleaning blade having the configuration shown in FIG. 3 is brought into contact with the surface of the photoreceptor. It is a figure which shows another structure of a 2nd cleaning blade. It is the schematic which shows another structure of the image forming apparatus equipped with the cleaning apparatus of this invention. FIG. 6 is a diagram schematically illustrating the shape of a toner in order to explain the shape factor SF-1 and the shape factor SF-2. FIG. 3 is a diagram schematically illustrating the shape of a toner according to the present invention.

Explanation of symbols

1 Photoconductor (image carrier)
2 Charging device 3 Exposure device 4 Developing device 6 Transfer device 7 Fixing device 8 Cleaning device 8a First cleaning blade 8b Second cleaning blade 81 First polishing member 81a Abrasive particle rich layer 82 Second polishing member 83 Gap forming member

10 Intermediate transfer belts 17 and 18 Cleaning device 24 Secondary transfer belt (transfer conveyance belt)

Claims (21)

A cleaning blade that contacts the surface moving body to remove deposits on the surface moving body,
The cleaning blade has a multilayer structure including at least a first polishing member in which abrasive particles are contained in an elastic material and a second polishing member made of a material having a Young's modulus of 1 GPa or more. A second polishing member is provided on the contact surface side ;
The cleaning blade , wherein edges of the first polishing member and the second polishing member are provided so as to be in contact with the surface moving body . The cleaning blade according to claim 1, wherein
The cleaning blade, wherein the second polishing member is made of resin. The cleaning blade according to claim 2,
The cleaning blade, wherein the second polishing member is made of a biaxially stretched polyester film. The cleaning blade according to claim 3, wherein
The cleaning blade, wherein the polyester film has a thickness of 0.01 to 1.0 mm. The cleaning blade according to claim 1, wherein
The second polishing member is made of a metal plate. The cleaning blade according to claim 5, wherein
The cleaning blade, wherein the metal plate has a thickness of 0.01 to 0.5 mm. The cleaning blade according to any one of claims 1 to 6,
A cleaning blade , wherein a gap forming member is provided between the first polishing member and the second polishing member . The cleaning blade according to any one of claims 1 to 7,
A cleaning blade, wherein the first polishing member has a rubber hardness of 60 to 85 degrees . The cleaning blade according to claim 8 , wherein
An apparent rubber hardness of the cleaning blade is 80 to 100 degrees . A cleaning device for cleaning the surface of a surface moving body in an image forming apparatus, the surface of which moves while carrying toner or a recording member,
The first cleaning blade and the second cleaning blade are arranged in order from the upstream side in the moving direction of the surface moving body,
A cleaning device, wherein the second cleaning blade is the cleaning blade according to claim 1 . The cleaning device according to claim 10, wherein
The cleaning apparatus, wherein the first cleaning blade contacts the surface moving body by a counter method, and the second cleaning blade contacts the surface moving body by a trailing method . The cleaning device according to claim 11, wherein
The cleaning device according to claim 1, wherein the contact angle of the second cleaning blade is 5 to 25 degrees . The cleaning device according to claim 11 or 12 ,
Contact pressure of the second cleaning blade, a cleaning device, characterized in that the 10~80gf / cm. A process cartridge that is integrally supported and includes at least an image carrier and a cleaning unit that cleans the surface of the image carrier, and is detachably formed on the image forming apparatus main body.
A process cartridge comprising the cleaning device according to claim 10 as the cleaning means . An image carrier for carrying a latent image ;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
In an image forming apparatus comprising transfer means for transferring a visible image on the surface of an image carrier to a recording member,
The image forming apparatus as a means for cleaning the surface of the image bearing member, an image forming apparatus, characterized in that it comprises a cleaning device according to any one of claims 10 to 13. An image carrier for carrying a latent image;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
In an image forming apparatus comprising a transfer unit that temporarily transfers a visible image on the surface of an image carrier to an intermediate transfer member, and then transfers the visible image held by the intermediate transfer member to a recording member.
The image forming apparatus includes the cleaning device according to claim 10 as means for cleaning the surface of the intermediate transfer member . An image carrier for carrying a latent image;
Charging means for uniformly charging the surface of the image carrier;
Exposure means for exposing the surface of the charged image carrier based on image data and writing a latent image;
Developing means for supplying a toner to the latent image formed on the surface of the image bearing member to visualize the latent image;
A transfer unit that transfers the visible image on the image bearing member surface to record member,
In an image forming apparatus comprising a recording member support that conveys while supporting a recording member in the vicinity of a transfer position ,
The image forming apparatus includes the cleaning device according to claim 10 as means for cleaning the surface of the recording member support . The image forming apparatus according to any one of claims 15 to 17 ,
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) of 1.00 to 1.40. An image forming apparatus characterized by being in the range . The image forming apparatus according to any one of claims 15 to 18,
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. And / or an image forming apparatus, wherein the toner is obtained by an extension reaction . The image forming apparatus according to any one of claims 15 to 19,
The image forming apparatus according to claim 1 , wherein 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 according to any one of claims 15 to 20,
The toner used in the developing unit has a substantially spherical shape, and the shape is defined by a major axis r1, a minor axis r2, and a thickness r3 (provided that r1 ≧ r2 ≧ r3), and the major axis r1 and the short axis. The ratio (r2 / r1) to the axis r2 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. An image forming apparatus.

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