JP4855045B2 - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a cleaning apparatus, a process cartridge, and an image forming apparatus, and more particularly, to a cleaning apparatus, a process cartridge, and an image forming apparatus that clean an image carrier with a cleaning blade.

  In recent years, an electrophotographic system has been adopted in the field of image forming apparatuses such as copying machines, printers, and fax machines.

  In an electrophotographic image forming apparatus, an electrostatic latent image is formed on a charged image carrier by irradiating a writing laser beam, and the electrostatic latent image is developed with a developing device as a toner image. Visualize. Then, the toner image is transferred to an intermediate transfer member, and the transferred toner image is transferred onto a recording sheet to form an image.

  In such an image forming apparatus, after transfer to the intermediate transfer member, toner and paper powder that did not contribute to the transfer remain on the image carrier. This residual toner or the like may adversely affect subsequent image formation.

  In order to cope with this, a cleaning device that removes residual toner and the like on the image carrier is provided in the vicinity of the image carrier, and the residual toner and the like are removed by the cleaning device to prepare for the next image formation. It is configured.

  As this cleaning device, a blade type device using a blade member is known. In the blade type cleaning device, the edge of the blade member is brought into pressure contact with the surface of the image carrier to forcibly remove the toner remaining on the surface of the image carrier. The blade system is widely adopted because it has a simple structure and a high cleaning effect.

  In the blade type cleaning device, the removal performance of the residual toner depends on the contact pressure of the blade member with respect to the image carrier, and the higher the contact pressure, the higher the removal performance. Therefore, in the conventional cleaning device, the blade member is in strong contact with the surface of the image carrier.

  However, when the contact pressure is increased, there is a demerit that the blade member is turned up due to the frictional force with the image carrier and a cleaning failure occurs. Also, since the wear pace of the image carrier and the wear pace of the blade member are increased, there is a demerit that the life of the apparatus is shortened.

  The blade member is generally made of urethane rubber or the like, and its viscoelastic characteristics depend on temperature. With the temperature at which the viscoelastic property reaches a peak as a boundary, the upper side (high temperature side) of the peak temperature is an elastic region, and the lower side (low temperature side) is an inelastic region. Below the peak temperature, the blade member no longer exhibits rubber properties, so that the cleaning performance is particularly deteriorated.

  Therefore, in order to obtain stable cleaning characteristics, it is necessary to define the viscoelastic characteristics (tan δ peak temperature) of the blade member as well as the temperature conditions to be used.

  In particular, the cleaning performance is likely to deteriorate in a low-temperature and low-humidity environment, so that the temperature of the image carrier or blade member is kept constant even in a low-temperature and low-humidity environment, or the blade member is used at a temperature higher than the tan δ peak temperature. It is necessary to define the tan δ peak temperature as described above.

  The following are known as techniques proposed for solving this problem.

  Patent Document 1 proposes a cleaning device provided with a heater for adjusting the temperature in the vicinity of the blade member or in the blade member itself in the cleaning device. With this configuration, the blade member is prevented from becoming low temperature, and cleaning can be performed with high wear resistance and high elastic force.

  In Patent Document 2, a drum heater is provided, the value of the viscoelasticity tan δ when the cleaning device is used is defined, and the temperature of the image carrier or the blade member is adjusted by the drum heater so that the specified viscoelasticity tan δ is obtained. An image forming apparatus to be adjusted has been proposed.

  The length of the blade member in the longitudinal direction is wider than the maximum image forming area. However, since there is no residual toner at the outer edge of the image forming area, the blade member at the outer edge is not exposed to the blade member. The amount of input toner is small and the frictional force acting on the blade member tends to increase. For this reason, depending on the use environment of the image forming apparatus, the frictional force acting on the blade member becomes non-uniform in the longitudinal direction, and there is a possibility that an image abnormality due to poor cleaning occurs at the end in the longitudinal direction.

Therefore, Patent Document 3 proposes an image forming apparatus provided with a temperature adjustment device that is built in an image carrier and that can change the surface temperature of the end portion in the longitudinal direction of the blade member with respect to the surface temperature of the central portion in the longitudinal direction. Has been.
Japanese Patent Laid-Open No. 6-186885 Japanese Patent Laid-Open No. 11-119620 JP 2004-144949 A

  However, the above technique has the following problems.

  The techniques described in Patent Document 2 and Patent Document 3 use a drum heater as a means for heating the surface of the image carrier, so that it takes time to adjust the entire surface of the image carrier to a target temperature. Therefore, when image formation is performed immediately after startup in a low-temperature and low-humidity environment or immediately after returning from the energy-saving mode, image formation may be performed before the surface of the image carrier reaches the target temperature. May occur.

  In the technique described in Patent Document 1, since the heater is provided in the vicinity of the blade member or in the blade member itself in the cleaning device, the time for heating the cleaning member to the target temperature can be shortened compared to the method using the drum heater. The viscoelastic properties (tan δ peak temperature) of the blade member are not defined at all. For this reason, when the tan δ peak temperature of the blade member is higher than the temperature heated by the heater, the blade member itself does not exhibit rubber characteristics, and it becomes difficult to perform the targeted stable cleaning.

  In addition, since all of the techniques of Patent Documents 1 to 3 described above use a heater as a heating means, it is not easy to control the target temperature, and power consumption increases more than necessary.

  The present invention has been proposed in view of the above-described problems, and provides a cleaning device, a process cartridge, and an image forming apparatus capable of obtaining a stable cleaning property even in a low temperature and low humidity environment in which cleaning failure is likely to occur. For the purpose.

  More specifically, an object of the present invention is to provide a cleaning device, a process cartridge, and an image forming apparatus in which the rise time until the blade member is adjusted to a target temperature is short and the temperature can be easily controlled.

First aspect of the present invention has a blade member, by contact with the blade member to the image bearing member, a cleaning device for removing toner of the image bearing member surface is heated by electric magnetic induction A plate-shaped holder member made of a magnetic material and bonded to the blade member to support the blade member, and an exciting coil wire covering the plate surface of the holder member including the bonding portion of the holder member with the blade member An electromagnetic induction heating means having an excitation coil regularly arranged as described above, a ferrite core arranged in proximity to the excitation coil, a temperature detection means for detecting the temperature of the holder member, and the holder and a control means for controlling the temperature of members within a predetermined temperature range, wherein the control means supplies a high frequency alternating current to the exciting coil, the holder member and the electromagnetic induction By heating, and performs temperature control of the blade member.

  According to a second aspect of the present invention, in the cleaning device according to the first aspect, the blade member surrounds the holder member and is integrally formed.

According to a third aspect of the present invention, in the cleaning device according to the first or second aspect, the predetermined temperature range is 25 ± 5 ° C.

According to a fourth aspect of the present invention, in the cleaning device according to any one of the first to third aspects, a tan δ peak temperature at 10 Hz of the blade member is on a lower temperature side than the predetermined temperature range. And

According to a fifth aspect of the present invention, in the cleaning device according to the fourth aspect, the tan δ peak temperature at 10 Hz of the blade member is 6 ° C. or higher and 10 ° C. or lower.

  According to a sixth aspect of the present invention, in the cleaning device according to any one of the first to fifth aspects, the blade member is pressed against the image carrier at a contact pressure of 0.2 to 0.5 N / cm. It is characterized by that.

  According to a seventh aspect of the present invention, in the cleaning device according to any one of the first to sixth aspects, the blade member has a hardness of 70 to 80 ° and a rebound resilience at 20 ° C. of 20 to 40. %.

  The invention according to claim 8 comprises the image carrier and the cleaning device according to any one of claims 1 to 7, wherein at least one of the charging means and the developing means is integrated. This is a process cartridge to be formed.

  According to a ninth aspect of the present invention, there is provided an image forming apparatus comprising the cleaning apparatus according to any one of the first to seventh aspects.

  According to a tenth aspect of the present invention, there is provided an image forming apparatus comprising the process cartridge according to the eighth aspect.

  According to the eleventh aspect of the invention, in the image forming apparatus according to the ninth or tenth aspect, the volume average particle diameter Dv of the toner used as the developer is 3.0 to 8.0 μm, and the volume average particle diameter Dv is The ratio Dv / Dn of the number average particle diameter Dn is 1.0 to 1.2, and the average circularity is 0.930 to 0.965.

  According to a twelfth aspect of the present invention, in the image forming apparatus according to the eleventh aspect, an additive having a particle size of 80 nm or more is added to the toner, and the amount of the additive is 0.5 to 2. It is 0% by weight.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to the eleventh or twelfth aspect, the toner is a toner composition containing a toner binder component made of a modified polyester resin capable of reacting with a compound having an active hydrogen group. An oil phase is formed by dissolving and / or dispersing in an organic solvent, and the oil phase is dispersed in an aqueous medium containing organic resin fine particles to obtain an emulsified dispersion, and the modification is performed in the emulsified dispersion. The polyester resin is obtained by subjecting a compound having an active hydrogen group to an extension reaction and / or a crosslinking reaction.

  According to the present invention, in a cleaning device having a blade member that contacts an image carrier and removes toner on the image carrier, a holder member made of a magnetic material and supporting the blade member is heated by electromagnetic induction. The temperature of the blade member is controlled. As a result, a stable cleaning property can be obtained even in a low-temperature and low-humidity environment where poor cleaning is likely to occur. Also, since the rise time until the blade member is heated to the target temperature is fast and it is easy to control the target temperature in a short time, immediately after startup in a low temperature and low humidity environment or immediately after returning from the energy saving mode It is also possible to suppress the occurrence of poor cleaning in

  Hereinafter, a cleaning device according to the present invention will be described in detail according to an embodiment.

<Configuration of cleaning device>
First, the configuration of the cleaning device of this embodiment will be described with reference to FIG.

  The cleaning device 10 includes a cleaning blade 11, a blade holder 12, an excitation coil 13, a ferrite core 14, and a temperature detection sensor 15.

  The cleaning blade 11 as a blade member is pressed against and contacted with the photosensitive drum 20 as an image carrier, and forcibly removes residual toner, paper dust and the like on the photosensitive drum 20.

  The blade holder 12 as a holder member is a member for fixing and holding the cleaning blade 11, and is made of a magnetic material. In the cleaning device 10 of this embodiment, the blade holder 12 is heated by electromagnetic induction, and the generated heat is conducted to the cleaning blade 11 to adjust the temperature of the cleaning blade 11.

  The exciting coil 13 is a coil in which a single long exciting coil wire is regularly wound in the axial direction of the blade holder 12, and the blade holder 12 is heated by exciting the coil. The exciting coil 13 is connected to an IH inverter (not shown).

  In addition, a ferrite core 14 that is a ferromagnetic material is disposed close to the exciting coil 13. In the cleaning device 10 of the present embodiment, the ferrite core 14 having a relative permeability of 2500 is disposed.

  The excitation coil 13 is fed with a high frequency alternating current of 10 KHz to 1 MHz, more preferably a high frequency alternating current of 20 KHz to 800 KHz. As a result, an alternating magnetic field is generated, and the alternating magnetic field acts on the blade holder 12. At this time, an eddy current flows in a direction that prevents the change of the alternating magnetic field inside. Since this eddy current generates Joule heat proportional to the resistance of the blade holder 12, the blade holder 12 is heated by electromagnetic induction.

  As described above, in the cleaning device of this embodiment, the blade holder 13 can be directly heated by driving the excitation coil 13 at a high frequency, so that efficient power control is possible. Moreover, start-up control in a short time and energy saving can be achieved.

  The constituent material of the blade holder 12 can be appropriately selected as long as it generates eddy current by an alternating magnetic field generated from the exciting coil 13 and generates Joule heat by this eddy current. In order to enable heating in an extremely short time, it is preferable to use a ferromagnetic material such as iron, cobalt, or nickel.

  The temperature detection sensor 15 as temperature detection means is joined to the blade holder 12 and detects the holder temperature of the blade holder 12. As the temperature detection sensor 15, for example, a thermistor can be used. The temperature detection sensor 15 is connected to an IH inverter (not shown) together with the excitation coil 13.

  The IH inverter as the control means controls the temperature of the blade holder 12 to be within a certain range by changing the frequency, the pulse width, and the like according to the temperature detected by the temperature detection sensor 15. The IH inverter is controlled by a control unit that controls the entire image forming apparatus.

<Range of temperature control>
In the cleaning device 10 of the present embodiment, the temperature of the blade holder 12 is controlled within a range of 25 ± 5 ° C. When the image forming apparatus is used in a normal environment, the temperature is usually in a range of 25 ± 5 ° C. Therefore, even if the use environment changes, it is possible to continuously obtain a performance equivalent to the cleaning performance obtained in the normal environment. .

<Tan δ peak temperature value>
As described above, in the cleaning device 10 of the present embodiment, the blade holder 12 is controlled in the range of 25 ± 5 ° C. Therefore, the material of the cleaning blade 11 is determined so that the tan δ peak temperature at 10 Hz of the cleaning blade 11 is lower than the temperature range. As a result, the temperature does not fall below the tan δ peak temperature, so that the cleaning blade 11 does not exhibit rubber properties, and the cleaning performance is reduced, and chattering of the cleaning blade 11 (the photosensitive drum 20 is uniformly pressed in the longitudinal direction). It is possible to prevent the occurrence of the occurrence of a state that is not performed) from occurring.

  In addition, even if it is above the tan δ peak temperature, the temperature dependence of tan δ has a large effect at a temperature close to the tan δ peak temperature. Therefore, it is necessary to reduce the temperature dependency by slightly separating the above temperature range from the tan δ peak temperature. Therefore, it is even more preferable to select a material such that the tan δ peak temperature at 10 Hz of the cleaning blade 11 is 10 ° C. or lower.

<Cleaning blade joining mode>
In the cleaning device 10 shown in FIG. 1, the cleaning blade 11 and the blade holder 12 are fixedly bonded with an adhesive. When fixed and bonded with an adhesive, particles such as iron, cobalt, nickel, and conductive particles such as whisker and carbon black, which are conductive and high magnetic permeability particles, are mixed and dispersed in the adhesive. Is more preferable. By doing so, the heat generated from the blade holder 12 can be efficiently transmitted to the cleaning blade 11.

  In addition, when fixedly bonded using an adhesive, there is a fear that the heat of the blade holder 12 generated by electromagnetic induction may be prevented from being transmitted to the cleaning blade 11 (not easily transmitted). Therefore, as shown in FIG. 2, it is more preferable that the cleaning blade 11 is formed by integral molding (casting) so as to sandwich the blade holder 12. Specifically, a concave portion is formed on one side surface of the cleaning blade, and the blade holder 12 is inserted into the concave portion for bonding. With this configuration, the heat generated from the blade holder 12 can be transmitted to the cleaning blade 11 more efficiently.

<Hardness of cleaning blade>
When the hardness of the cleaning blade 11 (specified by the JIS-A hardness / JIS K6253 hardness test) is less than 70 °, the cleaning blade 11 itself is soft and easy to wear. The cleaning performance is likely to deteriorate over time. When the hardness exceeds 80 °, the photoconductor drum 20 is abraded and fog is likely to occur, and the cleaning blade 11 is easily chipped, and the cleaning performance is likely to deteriorate over time. .

  Therefore, in the cleaning device 10 of the present embodiment, the hardness of the cleaning blade 11 is set to 70 to 80 °, more preferably 72 to 76 °, and the rebound resilience at 25 ° C. is set to 20 to 40%. Thereby, it is possible to suppress the deterioration of the cleaning performance with time.

<Contact pressure of cleaning blade>
When the contact pressure of the cleaning blade 11 to the photosensitive drum 20 is less than 0.2 N / cm, the pressure contact with the photosensitive drum 20 by the cleaning blade 11 is weak, the toner blocking force is remarkably reduced, and the toner is easy to slip through. Therefore, high cleaning performance cannot be realized. When the contact pressure exceeds 0.5 N / cm, a large torque is required to rotate the photosensitive drum 20, and blade squeal is likely to occur. Further, the cleaning blade 11 is bent and deformed, and the photosensitive drum 20 is in a so-called belly contact state, resulting in a cleaning failure.

  Therefore, in the cleaning device 10 of this embodiment, the contact pressure of the cleaning blade 11 to the photosensitive drum 20 is set to 0.2 to 0.5 N / cm, more preferably 0.25 to 0.4 N / cm. . As a result, the above disadvantages can be avoided and suppressed.

<Material of cleaning blade>
The cleaning blade 11 in the cleaning device 10 of this embodiment is formed of a polyurethane material. A polyurethane is obtained by reaction of an isocyanate compound and a polyol compound.

  Examples of the isocyanate compound include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate. It is done.

  Examples of the polyol compound include polyether polyol, polyester polyol, acrylic polyol, and epoxy polyol. In addition, as a raw material monomer constituting the acrylic polyol, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, Isobutyl methacrylate, n-hexyl methacrylate, lauryl methacrylate, acrylic acid, methacrylic acid, maleic acid, itaconic acid, 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, Examples include acrylamide, N-methylol acrylamide, diacetone acrylamide, glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, and acrylonitrile.

<Image forming apparatus>
Next, an image forming apparatus including the above-described cleaning device 10 will be described with reference to FIG.

  The image forming apparatus 1 shown in FIG. 3 forms toner images for each color of yellow (Y), magenta (M), cyan (C), and black (K), and superimposes them to form a full-color image. A tandem image forming apparatus to be formed, which includes a document table 21, a reading device 22, an optical scanning device 23, a photosensitive drum 20 (YMCK), a charging roller 24 (YMCK), and a developing device 25 (YMCK). Cleaning device 10 (YMCK), intermediate transfer belt 26, transfer roller 27, fixing device 28, paper feed roller 29, paper feed tray 30, paper discharge roller 31, paper discharge tray 32, It is comprised.

  The document table 21 is a table on which a document to be printed, that is, a document to be read is placed. The lower surface of the document table 21 is formed from contact glass.

  The reading device 22 is a device that reads a document placed on the document table 21, and reads the content of the document by irradiating the document with laser light and receiving reflected light from the document.

  The optical scanning device 23 irradiates the photosensitive drum 20 corresponding to each color with a writing laser beam based on the image data (document content read by the reading device 22).

  The photosensitive drum 20 (YMCK) is a drum-shaped image carrier provided for each color of YMCK. The photosensitive drums 20 have the same diameter and are pressed on the intermediate transfer belt 26 at equal intervals.

  The charging device 24 (YMCK) is a roller-shaped device arranged in contact with each color photosensitive drum 20 and charges the surface of the photosensitive drum 20. An electrostatic latent image corresponding to each color is formed on the photosensitive drum 20 by irradiating the charged surface of the photosensitive drum 20 with laser light from the optical scanning device 23.

  The developing device 25 (YMCK) is a roller-type device disposed in contact with each photosensitive drum 20, and holds toner (developer) of a color corresponding to the photosensitive drum 11 corresponding to each color. At the time of image formation, the electrostatic latent image formed on the photosensitive drum 20 is developed to form a toner image.

  The cleaning device 10 (YMCK) removes and collects residual toner and the like on the photosensitive drum 20. Here, the cleaning device 10 of the above-described embodiment is used.

  The intermediate transfer belt 26 is an endless belt for sequentially superimposing and transferring the color toner images formed on the surface of the photosensitive drums 20. A color image is formed on the intermediate transfer belt 26 by sequentially superimposing the respective color toner images.

  The transfer roller 27 is a roller for transferring the color image formed on the intermediate transfer belt 26 onto the recording paper conveyed from the paper feed tray 30.

  The fixing device 28 is a device that heat-fixes the color image transferred onto the recording paper onto the recording paper.

  The paper feed roller 29 feeds recording paper. The paper feed tray 30 is a tray that stocks recording paper for each recording paper size. The paper discharge roller 31 discharges the recording paper on which the color image is thermally fixed to the outside of the image forming apparatus 1. The paper discharge tray 32 is a tray on which the discharged recording paper is placed.

  The photosensitive drums 20 all rotate in the same direction. Further, the intermediate transfer belt 26 moves in a direction opposite to the rotation direction of the photosensitive drum 11. In FIG. 3, the photosensitive drum 20 rotates counterclockwise, and the intermediate transfer belt 26 rotates clockwise.

<Image creation operation>
An image forming operation (image forming operation) in the image forming apparatus 1 will be described. The document placed on the document table 21 is read by the reading device 22 and the read content is transmitted to the optical scanning device 23 as image data. The optical scanning device 23 irradiates a writing laser based on the image data, and forms an electrostatic latent image corresponding to each color on the photosensitive drum 20 charged by the charging device 24.

  The electrostatic latent image is developed with toner by the developing device 25 corresponding to each color to form a toner image, and the toner image is sequentially superimposed and transferred onto the intermediate transfer belt 26 to form a color image. The color image is transferred onto the recording paper conveyed by the transfer roller 27 and thermally fixed by the fixing device 28. After the thermal fixing, the recording paper, that is, the printed matter on which the color image is thermally fixed, is discharged by a paper discharge roller 31 to a paper discharge tray 32 outside the image forming apparatus 1.

  Further, after the toner image is transferred, residual toner or the like adhering on the photosensitive drum 20 is removed and collected by the cleaning device 10.

  In the image forming apparatus 1 of the present embodiment, the above-described cleaning device 10 is used as the cleaning device 10 that removes and collects residual toner on the photosensitive drum 20. Therefore, efficient power control, startup control in a short time, and energy saving can be achieved for the cleaning device 10. Therefore, for example, it is possible to suppress the occurrence of defective cleaning when an image is formed immediately after startup in a low-humidity / low-frequency environment or immediately after returning from the energy saving mode. Further, even if the use environment changes, it is possible to continuously obtain the same performance as the cleaning performance obtained in the normal environment.

<Process cartridge>
Note that the above-described cleaning device 10 may be integrally configured as a process cartridge. FIG. 4 shows a configuration of the process cartridge 40 including the cleaning device 10.

  The process cartridge 40 is formed by integrating a photosensitive drum 20 as an image carrier, a charging roller 24 as a charging unit, a developing device 25 as a developing unit, and a cleaning device 10. An opening for guiding the writing laser beam from the optical scanning device 23 to the photosensitive drum 20 is formed in the upper part of the process cartridge 40.

  The process cartridge 40 is configured to be detachable from the image forming apparatus 1.

  When the laser beam for writing is irradiated from the optical scanning device 23 onto the photosensitive drum 20 charged by the charging roller 24, an electrostatic latent image is formed. The electrostatic latent image is developed by the developing device 25 to form a toner image. The cleaning device 10 removes and collects residual toner remaining on the photosensitive drum 20 after the transfer of the toner image.

  Since the configuration of the cleaning device 10 is as described above, the description thereof is omitted here.

  By configuring the cleaning device 10 and the photosensitive drum 20 as a process cartridge in this manner, maintenance and replacement work can be easily performed, which can contribute to user convenience.

  In FIG. 4, the photosensitive drum 20, the charging device 24, the developing device 25, and the cleaning device 10 are integrated to form the process cartridge 40. The drum 20 and the cleaning device 10 may be provided, and at least one of the charging unit and the developing unit may be integrated and formed as a process cartridge.

<Toner>
Next, the toner used in the image forming apparatus 1 and the process cartridge 40 described above will be described.

<Average particle size and particle size distribution of toner>
In general, it is said that the smaller the particle size of the toner, the more advantageous it is to obtain a high-resolution and high-quality image.

  However, a small toner particle size is disadvantageous in terms of transferability and cleaning properties. Further, when the volume average particle diameter (Dv) is smaller than 3.0 μm, 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 25 and the charging ability of the magnetic carrier is lowered I will let you. Further, in the one-component developer, toner filming on the developing roller of the developing device 25 and toner fusion to a member such as a doctor blade for thinning the toner are likely to occur.

  On the contrary, when the volume average particle diameter of the toner is larger than 8.0 μm, it becomes difficult to obtain a high-resolution and high-quality image and the toner in the developer is balanced. In many cases, the variation in the particle size of the particles increases. On the other hand, if Dv / Dn (Dn: number average particle diameter) exceeds 1.2, the charge amount distribution becomes wide and the resolving power decreases, so that the formed image is deteriorated.

  Therefore, in this embodiment, the volume average particle diameter (Dv) is 3.0 to 8.0 μm, and the ratio Dv / Dn of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1. A toner that is 0 to 1.2 is used. By using a toner having such a particle size and particle size distribution, excellent heat-resistant storage stability, low-temperature fixability, and hot offset resistance are obtained, and particularly excellent gloss is obtained when used in a full-color copying machine. Is possible.

<Measuring method of average particle size and particle size distribution of toner>
The average particle size and particle size distribution of the toner can be measured by using a Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter Inc.).

  Hereinafter, a method for measuring the average particle size and particle size distribution of the toner will be described in detail.

  First, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. Here, ISOTON R-II (manufactured by Coulter Scientific Japan Co., Ltd.) prepared with about 1% NaCl aqueous solution using primary sodium chloride was used as the electrolytic aqueous solution.

  2-20 mg of the measurement sample was added to the electric field aqueous solution and suspended, and the dispersion treatment was performed for about 1 to 3 minutes with an ultrasonic disperser. Then, the volume and number distribution of the toner particles in the measurement sample are measured for each channel by using the 100 μm aperture as the aperture, and the volume distribution and the number distribution of the toner are calculated.

  The channels are 2.00 to 2.52 μm, 2.52 to 3.17 μm, 3.17 to 4.00 μm, 4.00 to 5.04 μm, 5.04 to 6.35 μm, 6.35 to 8.00 μm, 8.00 to 10.08 μm, 10.08 to 12.70 μm, 12.70 to 16.00 μm, 16.00 to 20.20 μm, 20.20 to 25.40 μm, 25.40 to 32. 13 channels of 00 μm, 32.00 to 40.30 μm were used.

<Average circularity of toner>
Next, the average circularity of the toner will be described. The average circularity (SR) is a numerical value defined by “perimeter of a circle having the same area as the particle projection area / perimeter of the particle projection image”. The closer it is, the closer to 1.

  A toner having a high average circularity is easily affected by a developing electric field and is faithfully developed along the electric field of the electrostatic latent image. Therefore, dense and uniform development is possible, and fine line reproducibility can be enhanced. In addition, the toner with a high average circularity has a smooth and moderate fluidity, so it is easily affected by the electric field, and is easily transferred faithfully along the electric field, resulting in a high transfer rate and high quality. An image can be obtained.

  On the other hand, if the average circularity of the toner is less than 0.930, faithful development and transfer with a high transfer rate cannot be performed.

  Therefore, the average circularity is preferably 0.930 or more. In the present embodiment, toner having an average circularity of 0.930 to 0.965 is used.

  In addition, the toner manufactured by dry pulverization is spheroidized thermally or mechanically. The thermal spheronization treatment is performed, for example, by spraying the toner base particles together with a hot air current on an atomizer or the like. The mechanical spheronization treatment is performed, for example, by putting toner base particles 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 having a large particle size are aggregated, and in the mechanical spheronization process, fine powder is generated. Therefore, the classification process is required again.

  In addition, the shape of a toner produced in an aqueous solvent can be controlled by applying strong agitation in the step of removing the solvent.

<Measuring method of average circularity of toner>
The average circularity of the toner can be measured by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 to 0.5 ml of a surfactant, preferably alkyl benzene sulfonate, is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. Add about 1-0.5g. The obtained suspension is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the dispersion concentration is set to 3000 to 10,000 / μl, and the shape and distribution of the toner are measured by the above-described analyzer.

<External additive>
Next, external additives (additives) for toner will be described.

  As the external additive used in the toner, inorganic fine particles are preferably used. Examples of inorganic fine particles include silica, alumina, titania, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth, and oxidation. Examples thereof include chromium, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  Among these inorganic fine particles, silica is particularly preferably used, and among the inorganic fine particles, an external additive having a particle size of 80 nm or more is preferable. Since the external additive having a particle size larger than 80 nm stays at the edge of the cleaning blade 11, a dam effect can be exhibited, and slipping can be suppressed and good cleaning performance can be maintained.

  Further, when the amount of the external additive having a particle size of 80 nm or more is less than 0.5% by weight, it is difficult to stay on the edge of the cleaning blade 11 and the dam effect cannot be exhibited, so that the toner or the like is easily slipped through. If the amount exceeds 2.0% by weight, the film is fixed to the surface of the photosensitive drum 20 and filming is likely to occur. Therefore, the amount of the external additive is 0.5 to 2.0% by weight, more preferably 1.0 to 2.0% by weight.

<Production of toner>
In the toner, a toner material solution in which at least a polymer having a site capable of reacting with a compound having an active hydrogen group, polyester, colorant, and release agent is dissolved or dispersed in an organic solvent is crosslinked in an aqueous medium. It is produced by a reaction and / or extension reaction.

<Constituent materials of toner>
This will be specifically described below. First, constituent materials of the toner will be described.

(Modified polyester)
The toner of the present exemplary embodiment includes a modified polyester (i) as a binder resin.

  The modified polyester (i) indicates a polyester in which a bonding group other than an ester bond is present in the polyester resin, or a polyester in which resin components having different structures are bonded to each other by a covalent bond, an ionic bond, or the like. For example, a resin in which a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group is introduced into a polyester terminal, and an active hydrogen-containing compound and a polyester having these groups are reacted to modify the polyester terminal is exemplified. be able to.

  Specific 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). The polyester prepolymer (A) having an isocyanate group is a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC), and the polyester having an active hydrogen group is further converted to a polyvalent isocyanate compound (PIC). What reacted is mentioned. Examples of the active hydrogen group possessed by the polyester include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, and the like. Particularly preferred are alcoholic hydroxyl groups.

  The above urea-modified polyester is produced from the following materials.

  Examples of the polyhydric alcohol compound (PO) include a dihydric alcohol (DIO) and a trihydric or higher polyhydric alcohol (TO). A dihydric alcohol alone or a mixture of a dihydric alcohol and a small amount of a polyhydric alcohol is particularly preferred. 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.) adducts, and the like.

  Among these, 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 combination.

  As trihydric or higher polyhydric alcohol (TO), trihydric or higher polyhydric aliphatic alcohol (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.), trihydric or higher phenols (Trisphenol PA, phenol novolac, cresol novolac, etc.), alkylene oxide adducts of the above trivalent or higher polyphenols, and the like.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). A mixture with is particularly 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) , Naphthalenedicarboxylic acid, etc.). 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, you may make polyhydric carboxylic acid (PC) 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; the polyisocyanates are phenol derivatives, oximes, Examples thereof include those blocked with caprolactam and the like, and combinations of two or more thereof.

  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. The range is 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. This is because, when [NCO] / [OH] exceeds 5, the low-temperature fixability deteriorates, and when the molar ratio of [NCO] is less than 1, the urea content in the ester when a urea-modified polyester is used. This is because the 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 in the range of 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. It is. This is because when it is less than 0.5 wt%, hot offset resistance deteriorates and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. When it exceeds 40 wt%, low-temperature fixability deteriorates. Because it will end up.

  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. This is because when the number is less than 1 per molecule, the molecular weight of the urea-modified polyester becomes low and the hot offset resistance deteriorates.

  As amines (B) to be reacted with the polyester prepolymer (A), divalent amine compounds (B1), trivalent or higher polyvalent amine compounds (B2), amino alcohols (B3), amino mercaptans (B4), amino acids (B5), and those obtained by blocking the amino groups of B1 to B5 (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.) and alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.), 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 B1 to B5 blocked amino groups (B6) 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 the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). The ratio is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. This is because 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.

  Note that the urea-modified polyester may contain a urethane bond as well as a urea bond. Under the present circumstances, the molar ratio of urea bond content and urethane bond content is 100 / 0-10 / 90 normally, Preferably it is 80 / 20-20 / 80, More preferably, it is 60 / 40-30 / 70 is there. This is because hot offset resistance deteriorates when the molar ratio of urea bonds is less than 10%.

  The above-mentioned modified polyester (i) is produced by a one-shot method or a prepolymer method.

  The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. In addition, the peak molecular weight at this time is preferably 1000 to 10,000. This is because when the peak molecular weight is less than 1000, the elongation reaction is difficult and the elasticity of the toner is small and the hot offset resistance deteriorates. As a result, when the peak molecular weight exceeds 10,000, the fixing property is reduced or the particles are formed. This is because manufacturing problems are increased in pulverization.

  In the case of the modified polyester (i) alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, more preferably 2000 to 8000. This is because if it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color apparatus deteriorate.

  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 as the weight average molecular weight. .

  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).

(Unmodified polyester)
Not only the above-mentioned modified polyester (i) is used alone, but also the modified polyester (i) and unmodified polyester (ii) can be contained as a binder resin component. By using the unmodified polyester (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device can be improved, so that a more preferable result can be obtained than the single use of the modified polyester (i).

  Examples of the unmodified polyester (ii) include polycondensates of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) similar to the polyester component of the modified polyester (i). Same as (i).

  The unmodified polyester (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.

  If the modified polyester (i) and the unmodified polyester (ii) are at least partially compatible, it is advantageous in terms of low-temperature fixability and hot offset resistance. Therefore, a similar composition is preferable for the polyester component of the modified polyester (i) and the polyester component of the unmodified polyester (ii).

  The weight ratio of the modified polyester (i) and the unmodified polyester (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, particularly preferably. 7/93 to 20/80. This is because when the weight ratio of the modified polyester (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 the unmodified polyester (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. This is because when the peak molecular weight is less than 1000, the heat-resistant storage stability deteriorates, and when the peak molecular weight exceeds 10,000, the low-temperature fixability deteriorates.

  The hydroxyl value of the unmodified polyester (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. This is because a hydroxyl value of less than 5 is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  Moreover, 1-5 are preferable and, as for the acid value of unmodified polyester (ii), 2-4 are more preferable. 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. This is because 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. In addition, since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present embodiment has good heat storage stability even when the glass transition point is low as compared with the known polyester-based toner. Indicates.

(Coloring agent)
As the toner 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, bengara, red lead, red lead, cadmium red, cadmium mercury red, antimony red, permanent red 4R, para red, phise red, parachlor ortho nitroaniline red, risor fast scarlet G, Reliant 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, 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, Thioindigo Red B, Thioindigo Maroon , Oil red, quinacridone red, pyrazolone red, polyazo red, chrome vermilion, benzidine Range, 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, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt violet, manganese violet, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane, emerald green, pigment green B, naphthol green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Oxidized Chi Tan, 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. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus (Phosphorus) simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. 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. In particular, a material that controls the negative polarity of the toner is preferable.

  The amount of charge control agent used is not uniquely limited because it 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. 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. More preferably, it is used in the range of 0.2 to 5 parts by weight. This is because when the amount exceeds 10 parts by weight, the chargeability of the toner is too high, so that the effect of the charge control agent is reduced, the electrostatic attraction force with the developing roller of the developing device 25 is increased, and the flow of the developer is increased. This is because the image quality and image density are lowered.

(Release agent)
As the mold release agent, a low melting point wax having a melting point of 50 to 120 ° C. is used. This effectively works as a releasing agent between the fixing roller and the toner interface in the dispersion with the binder resin, and is effective against high temperature offset without applying a releasing agent such as oil to the fixing roller. An effect can be obtained.

  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 can be added when dissolved and dispersed in an organic solvent.

<Toner production method>
Next, a toner manufacturing method and manufacturing process will be described. In addition, although the following description shows a preferable manufacturing method, the manufacturing method is not limited to this.

  First, as a first step, 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.

  In order to facilitate the removal after the toner base particles are formed, the organic solvent is preferably volatile with a boiling point of less than 100 ° C. 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, Mention may be made of methyl isobutyl ketone 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.

  Moreover, the usage-amount of an organic solvent shall be 0-300 weight part with respect to 100 weight part of polyester prepolymers. In addition, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

  Next, as a second step, 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.

  If the amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid 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, and if it exceeds 20000 parts by weight, it is not economical. Therefore, the amount of the aqueous medium used with respect 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.

  In this step, a dispersant such as a surfactant and resin fine particles may be added as appropriate in order to improve the dispersion in the aqueous medium.

  Examples of this surfactant include 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, and the like. , Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivatives, polyvalent Nonionic surfactants such as alcohol derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine Agent can be used.

Further, by using a surfactant having a fluoroalkyl group, the effect can be increased with a very small amount of the surfactant. Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms and a metal salt thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C _{6 to} C ₁₁ ). Oxy] -1-alkyl (C ₃ -C ₄ ) sodium sulfonate, 3- [ω-fluoroalkanoyl (C ₆ -C ₈ ) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C ₁₁ ˜C ₂₀ ) carboxylic acid and metal salt, perfluoroalkyl carboxylic acid (C _{7 to} C ₁₃ ) and metal salt thereof, perfluoroalkyl (C _{4 to} C ₁₂ ) sulfonic acid and metal salt thereof, perfluorooctane sulfonic acid diethanolamine N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonami , Perfluoroalkyl (C ₆ ~C ₁₀₎ sulfonamide propyl trimethyl ammonium salts, perfluoroalkyl (C ₆ ~C ₁₀₎ -N- ethylsulfonyl glycine salts, monoperfluoroalkyl (C ₆ ~C ₁₆₎ ethyl phosphoric acid ester Etc. can be used. 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).

In addition, examples of the cationic surfactant include aliphatic 4 such as aliphatic primary, secondary or secondary amic acid and perfluoroalkyl (C ₆ -C ₁₀ ) sulfonamidopropyltrimethylammonium salt which are right on the fluoroalkyl group. Secondary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, and imidazolinium salts can be used. Trade names include Surflon S-121 (manufactured by Asahi Glass Co., Ltd.), Florard FC-135 (manufactured by Sumitomo 3M Company), Unidyne DS-202 (manufactured by Daikin Industries Co., Ltd.), MegaFuck F-150, F-824 (Dainippon Ink) And EFTOP EF-132 (manufactured by Tochem Products Co., Ltd.) and Footgent F-300 (manufactured by Neos).

  As the resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin. For example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate resin, or the like can be used. As the resin, two or more of the above resins may be used in combination.

  Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained. For example, vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid ester polymers. Examples thereof include resins such as a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer. The average particle size of the resin fine particles is 5 to 200 nm, preferably 20 to 300 nm.

  In addition, as a dispersant, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  The dispersed droplets may be stabilized by using a polymer protective colloid in combination with the resin fine particles and the inorganic compound dispersant. Specifically, it contains acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride, or a hydroxyl group (meth). Acrylic monomers, acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid -Γ-hydroxypropyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol mono METAKU Of lylic acid ester, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or compounds containing vinyl alcohol and carboxyl group Esters, 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 imidazole, Homopolymers or copolymers such as nitrogen-containing compounds such as ethyleneimine or those having a heterocyclic ring thereof, polyoxyethylene, polyoxypro Len, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene Polyoxyethylenes such as nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  Further, since the dispersion method is not particularly limited, a known dispersion method such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, or an ultrasonic wave can be applied. A high-speed shearing method is preferable in order to make the particle diameter 2 to 20 μm. When a high-speed shearing type disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. Moreover, although there is no limitation in particular about dispersion time, in the case of a batch system, it is 0.1 to 5 minutes normally. Moreover, as temperature at the time of dispersion | distribution, it is 0-150 degreeC (under pressure) normally, Preferably it becomes 40-98 degreeC.

  Next, as a third step, the amine (B) is added simultaneously with the preparation of the emulsion, and the reaction with the polyester prepolymer (A) having an isocyanate group is performed.

  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, specifically, dibutyltin laurate, dioctyltin laurate, etc. can be used as needed.

  Next, as a fourth step, after completion of the reaction with the polyester polymer (A), the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to generate toner base particles.

  The removal of the organic solvent is performed by gradually raising the temperature of the whole system in a laminar stirring state, giving strong stirring in a certain temperature range, and then removing the solvent. When an acid or alkali-soluble material such as calcium phosphate salt is used as the dispersion stabilizer, after dissolving the calcium phosphate salt with an acid such as hydrochloric acid, the calcium phosphate salt is removed from the toner base particles by a method such as washing with water. Can be removed. It can also be removed by other operations such as enzymatic degradation.

  Next, as a fifth step, a toner is generated by implanting a charge control agent into the toner base particles obtained in the fourth step, and then externally adding inorganic fine particles such as silica fine particles and titanium oxide fine particles.

  The charge control agent and the inorganic fine particles are externally added by a known method using a mixer or the like.

  By passing through the above manufacturing process, 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, it is possible to obtain a shape between a true spherical shape and a rugby ball shape, and furthermore, the surface morphology is controlled from a smooth one to a umeboshi shape. Can do.

  The toner manufactured by the above-described manufacturing process can be used as a one-component magnetic toner or non-magnetic toner that does not use a magnetic carrier, or a two-component developer that uses a magnetic toner.

  When used for a two-component developer, it is mixed with a magnetic carrier. This magnetic carrier is a ferrite containing a divalent metal such as iron, magnetite, Mn, Zn, Cu, and has a volume. The average particle diameter (Dc) is preferably 20 to 45 μm. This is because when the average particle size is less than 20 μm, carrier adhesion tends to occur on the photosensitive drum 20 during development, and when it exceeds 45 μm, the mixing with the toner is low and the charge amount of the toner is insufficient. This is because charging failure during continuous use tends to occur. Note that Cu ferrite containing Zn is optimal as a magnetic carrier because of its high saturation magnetization.

  Moreover, although it does not specifically limit about resin which coat | covers a magnetic carrier, For example, a silicone resin, a styrene-acryl resin, a fluorine-containing resin, an olefin resin etc. can be used. Even if the coating method is a method in which the coating resin is dissolved in a solvent, sprayed into the fluidized bed and coated on the core, the resin particles are electrostatically attached to the core particles and then melted by heat. The method of coating may be used. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.

  In addition, the above-described toner is excellent in fine line, fine dot reproducibility, toner graininess, and intermediate color reproducibility, so it can be used as a color toner for forming a color image. Suitable for

<Comparison evaluation>
Hereinafter, effects of the image forming apparatus 1 including the cleaning device 10 according to the present invention will be specifically described with reference to Examples and Comparative Examples.

  The following table shows the conditions of Examples 1 to 6 and Comparative Examples 1 to 4.

  Each condition will be described.

(Holder heating)
This is a condition for a method of heating the blade holder 12 of the cleaning device 10. About Examples 1-6 and Comparative Examples 3 and 4, the heating method by electromagnetic induction is employ | adopted as demonstrated in the above-mentioned embodiment. In Comparative Examples 1 and 2, the blade holder 12 is not heated.

(Blade joining method)
This is a condition for a method of joining the cleaning blade 11 and the blade holder 12. For Example 1 and Comparative Examples 1 and 2, a method of fixing and bonding with an adhesive is employed. On the other hand, in Examples 2 to 6 and Comparative Examples 3 and 4, a method in which the cleaning blade 11 is integrally bonded so as to sandwich the blade holder 12 and fixed and joined is adopted.

(Control temperature)
This is a condition for the temperature control range of the blade holder 12. About Example 1, it is 25 +/- 10 degreeC and about Examples 2-6 and the comparative example 4, it is 25 +/- 5 degreeC. Moreover, about the comparative example 3, it is 15 degreeC +/- 5 degreeC. In addition, about the comparative examples 1 and 2, since holder heating is not performed, it is blank.

(Blade hardness)
This is a condition for the hardness of the cleaning blade 11 (specified by the JIS-A hardness / JIS K6253 hardness test). It is 68 degrees for Examples 1 and 2 and Comparative Examples 1 to 3, and 70 degrees for Examples 3 to 5. Further, for Example 6, it is 74 °, and for Comparative Example 4, it is 66 °.

(Rebound resilience)
This is a condition for rebound resilience at 25 ° C. of the cleaning blade 11. It is 42% for Examples 1 and 2 and Comparative Examples 1 to 3, and 21% for Example 3. In addition, Examples 4 and 5 are 24%, Example 6 is 28%, and Comparative Example 4 is 50%.

(Tan δ peak temperature)
This is a condition for the tan δ peak temperature of the cleaning blade 11 at 10 Hz. It is 15 degreeC about Example 1, 2 and Comparative Examples 1-3, and is 8 degreeC about Example 3. FIG. Moreover, it is 6 degreeC about Examples 4-6, and is 10 degreeC about the comparative example 4. FIG.

(Contact pressure)
This is a condition for the contact pressure of the cleaning blade 11 to the photosensitive drum 20. It is 0.018 N / cm for Examples 1-4 and Comparative Examples 1-4, 0.022 N / cm for Example 5, and 0.028 N / cm for Example 6.

(Volume average particle size)
This is a condition for the volume average particle diameter (Dv) of the toner to be used. It is 6.8 μm for Examples 1 to 3 and Comparative Examples 1 to 3, and 6.0 μm for Examples 4 to 6 and Comparative Example 4.

(Volume average particle diameter / number average particle diameter)
This is the condition for the ratio Dv / Dn between the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner used. It is 1.33 about Examples 1-3 and Comparative Examples 1-3, and is 1.12 about Examples 4-6 and Comparative Example 4.

(Roundness)
This is a condition for the circularity of the toner to be used. It is 0.97 about Examples 1-3 and Comparative Examples 1-3, and is 0.95 about Examples 4-6 and Comparative Example 4.

(Additive amount)
This is a condition for the amount of the additive (external additive) having a particle size of 80 μm or more. For Examples 1 to 3 and Comparative Examples 2 and 3, it is 1.0% by weight, and for Examples 4 to 6 and Comparative Example 4 it is 0.7% by weight. In addition, about the comparative example 1, since the additive is not used, it is blank.

<Comparison evaluation>
An image forming apparatus that satisfies the conditions of Examples 1 to 6 and Comparative Examples 1 to 4 described above was prepared by replacing the cleaning device and toner used in a Ricoh color laser printer (IPSiO Color8000). Wet cleaning performance, cleaning performance immediately after start-up in a low temperature and low humidity environment (10 ° C / 15% RH), cleaning performance after running 20,000 sheets and 60,000 sheets, and heater heating type cleaning device Rank evaluation of power consumption was performed in five stages of 1-5. Note that. The higher the numerical value, the better the rank evaluation, and 5 is the best value.

  The results of this comparative evaluation are shown in Table 2.

<Comparison result>
From the above table, it can be determined that Examples 1-6 are superior to Comparative Examples 1-4. In Examples 1 to 6, it can be determined that a more favorable effect is shown as the number increases (as it approaches 6).

  About Examples 1-6, it is made to satisfy | fill the conditions which are suitable in the said embodiment as it approaches 6. FIG. From this, the effect of the cleaning device 10 of the above-described embodiment, that is, the cleaning device 10 according to the present invention has been demonstrated.

<Additional notes>
The above-described embodiment is merely an example of a preferred embodiment of the present invention, and is not intended to limit the embodiment of the present invention. Therefore, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

It is a figure which shows the structure of the cleaning apparatus of this embodiment. It is a figure which shows another structure of the cleaning apparatus of this embodiment. 1 is a diagram illustrating a configuration of an image forming apparatus. It is a figure which shows the structure of a process cartridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10 Cleaning apparatus 11 Cleaning blade 12 Blade holder 13 Excitation coil 14 Ferrite core 15 Temperature detection sensor 20 Photosensitive drum

Claims (13)

A cleaning device having a blade member and removing toner on the surface of the image carrier by bringing the blade member into contact with the image carrier;
Conductive magnetic made of a magnetic material heated by induction, a plate-shaped holder member is joined to said blade member for supporting said blade member,
An exciting coil in which the exciting coil wire is regularly arranged so as to cover the plate surface of the holder member including the joint portion of the holder member with the blade member, and a ferrite arranged in proximity to the exciting coil An electromagnetic induction heating means having a core;
Temperature detecting means for detecting the temperature of the holder member;
Control means for controlling the temperature of the holder member within a predetermined temperature range,
The said control means supplies the high frequency alternating current to the said excitation coil, and controls the temperature of the said blade member by heating the said holder member by electromagnetic induction, The cleaning apparatus characterized by the above-mentioned.   The cleaning device according to claim 1, wherein the blade member is integrally formed so as to surround the holder member. Wherein the predetermined temperature range, the cleaning device according to claim 1 or 2, wherein it is a 25 ± 5 ° C.. 4. The cleaning device according to claim 1, wherein a tan δ peak temperature at 10 Hz of the blade member is on a lower temperature side than the predetermined temperature range. 5. The cleaning device according to claim 4, wherein a tan δ peak temperature at 10 Hz of the blade member is 6 ° C. or more and 10 ° C. or less.   The cleaning apparatus according to claim 1, wherein the blade member is pressed against the image carrier at a contact pressure of 0.2 to 0.5 N / cm.   7. The cleaning device according to claim 1, wherein the blade member has a hardness of 70 to 80 ° and a rebound resilience at 25 ° C. of 20 to 40%.   A process cartridge comprising the image carrier and the cleaning device according to claim 1, wherein at least one of a charging unit and a developing unit is integrally formed.   An image forming apparatus comprising the cleaning device according to claim 1.   An image forming apparatus comprising the process cartridge according to claim 8. The toner used as the developer has a volume average particle diameter Dv of 3.0 to 8.0 μm,
The ratio Dv / Dn of the volume average particle diameter Dv and the number average particle diameter Dn is 1.0 to 1.2,
11. The image forming apparatus according to claim 9, wherein the average circularity is 0.930 to 0.965. An additive having a particle size of 80 nm or more is added to the toner,
12. The image forming apparatus according to claim 11, wherein the amount of the additive is 0.5 to 2.0% by weight. The toner is
An oil phase is formed by dissolving and / or dispersing a toner composition containing a toner binder component composed of a modified polyester resin capable of reacting with a compound having an active hydrogen group in an organic solvent,
An emulsified dispersion is obtained by dispersing the oil phase in an aqueous medium containing organic resin fine particles,
13. The image forming apparatus according to claim 11, wherein the image forming apparatus is obtained by subjecting the modified polyester-based resin and a compound having an active hydrogen group to an extension reaction and / or a crosslinking reaction in the emulsified dispersion. .

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