JP2007079117A - Magnetic toner, image forming method, and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide magnetic toner, an image forming method, and a process cartridge that can suppress a decrease in picture quality such as a blotch and a fog, a decrease in developing performance, a photoreceptor flaw, and in-machine scatter of magnetic toner even when a large-capacity process cartridge with increased processing speed and an increased amount of toner to be charged in a developing unit is used. <P>SOLUTION: A restriction blade which restricts a toner layer thickness on a toner carrier comprising a magnet roller which has a plurality of magnetic poles in a developing sleeve and is arranged not to rotate has 10-point average roughness Rz of 5.0 to 25.0 μm on a surface where the blade abuts against the toner carrier, a magnetic force (peak magnetic flux density) of a magnetic field of the magnet roller which acts in a developing sleeve center direction is 50 to 100 mT where the toner restriction blade abuts against the toner carrier, and the magnetic permeability of the magnetic toner is 0.6 to 1.2 μH/m. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic toner used to visualize an electrostatic charge image in an image forming method such as electrophotography.

  As a general electrophotographic image forming method, for example, a photoconductive material is used, an electric latent image is formed on an electrostatic latent image carrier by various means, and then the latent image is developed into a developing device. The toner image is visualized by developing it into a toner image, and then, if necessary, the toner image is transferred to a transfer material such as paper, and then fixed by heating, pressure, heating and pressurization or solvent vapor to obtain a toner image. The method is known.

  As a developing device in such an electrophotographic method, a rubber or metal toner regulating blade as a toner layer thickness regulating member for regulating the toner coating amount is generally applied to the surface of a developing sleeve as a toner carrier. Devices that are configured to contact each other are known.

  By the friction between the toner regulating blade and the toner and / or the friction between the developing sleeve and the toner, a positive or negative charge is given to the toner, and further, the developing sleeve in which the toner is thinly applied on the surface by the toner regulating blade, In general, a method of developing by flying and adhering to the electrostatic latent image on the surface of the electrostatic latent image bearing member facing the developing sleeve is performed.

  The development of the electrostatic latent image with the magnetic toner applied on the developing sleeve is particularly susceptible to the applied state of the toner, and if the amount of applied toner (coating amount) is small or uneven, it will remain as it is. Since it appears in a developed image, a beautiful image cannot be obtained. In addition, the magnetic powder lump or foreign matter mixed in the toner is attracted by the magnetic force of the magnet roller, and is easily clogged in the nip portion between the toner regulating blade and the developing sleeve. Will not be applied (coating loss). This appears as white streaks partially in the toner layer on the developing sleeve, and in severe cases, appears as undeveloped white streaks in the image. This is easy to occur especially during long-term use and has been a big problem.

  As the technical direction of image forming apparatuses in recent years, in addition to high definition, high quality, and high image quality, further high speed and long-term high reliability are required. In order to achieve a high-resolution, high-definition development system, development of toners having high development characteristics such as reduction in toner particle size and sharpening of particle size distribution is in progress.

  When such a highly developable toner is applied to a conventional developing device, the toner may be charged up or a thin layer may be coated on the developing sleeve due to differences in chargeability or powder characteristics. Inability to do so tends to result in lack of image definition.

  On the other hand, various attempts have been made to improve the toner regulating blade or the developing sleeve.

  For example, in Patent Document 1, the hardness and deformation rate of the surface of the developer carrier, and the ten-point average roughness (Rz) of the surface of the developer amount regulating blade on the side in contact with the developer carrier are 0. A developing device of 3 to 20 μm has been proposed. In this invention, an example in which non-magnetic black toner is evaluated using this developing device is described, and it is effective for solid image density, unevenness, streaks and the like in each environment. On the other hand, the stability in long-term durability has not been sufficiently studied, and in particular when one-component magnetic toner is used, the durability stability tends to be insufficient.

  Further, in Patent Document 2, the surface roughness of the developer regulating member is a ten-point surface average roughness Rz, which is larger than 2.0 μm, and the maximum height Rmax is smaller than the average particle diameter of the developer. A developer regulating member set as described above is disclosed. As described in the embodiments of the present invention, in the configuration of the metal blade and the non-magnetic toner, although the roller set phenomenon is surely effective, other than the metal blade, for example, a urethane rubber blade or silicon In particular, when a rubber blade is used, there are cases where the development stability and environmental stability are insufficient.

  Further, Patent Document 3 proposes a toner regulating blade that defines the surface roughness of the surface of the elastic blade member that slides on the developing roller. In the toner regulating blade of this invention, it is disclosed that the monocomponent magnetic toner having an average particle diameter of 8 μm is effective in the character thickening and charging stability in the examples. Although not mentioned, particularly when the toner having the high development characteristics as described above is applied, the durability stability and the environmental stability may be insufficient.

  In addition, Patent Documents 4 to 8 each disclose an invention that defines the surface roughness of the toner regulating blade.

  In these inventions, the roughness is defined in the vertical direction, but there is no discussion in the lateral direction such as the uneven spacing and convex density, and the performance depends on the environment and durability conditions. May be insufficient, which is essentially different from the idea of the present invention.

  When the above-described toner regulating blade is applied to a high-speed development system that uses a high-capacity cartridge, particularly with a high process speed, the above-described problems may become apparent, leaving room for further study. It is the present situation.

  Since the magnetic toner contains the magnetic material, the toner has magnetism, and the toner coat layer on the magnetic toner carrier (developing sleeve) forms magnetic spikes by the magnetic force of the toner. In jumping development using magnetic toner, development is generally performed while applying a developing bias to a photosensitive drum while maintaining a certain shape of a spike from the magnetic toner carrier.

  In such a development method, if the dispersion of the magnetic particles in the magnetic toner particles is insufficient and the variation in the magnetic properties of the toner particles becomes too wide, the spikes are likely to be disturbed. If this heading is disturbed (too long, too thick, or uneven in size), a blotch due to poor charging (toner that is not properly charged due to charge-up becomes defective regulation) There are problems such as the phenomenon of spots flowing out on the sleeve, causing spots and irregularities on the waves), scattering to the periphery of the image, and fog that develops the non-image area with toner. In addition, since the uniform toner layer is stably prevented from being supplied and conveyed to the fine latent image portion, the uniformity of the image density and the dot reproducibility are impaired.

  Further, when the magnetic residual shape remains in the transfer residual toner, there is a tendency that the photoconductor is easily scratched by rubbing with the cleaning blade.

  Also, the expansion of the width of the charge distribution due to the poor dispersion of the magnetic material as described above facilitates so-called selective development in which toner having a certain amount of charge amount distribution is preferentially consumed, and at the same time, the selective development proceeds. As a result, the above-mentioned problem may be further promoted.

  Since the magnetic toner has different forces from the developing sleeve depending on the inherent magnetic permeability and particle size of the toner, the amount of magnetic toner transported by the developing sleeve (the coating amount) differs. In particular, along with the recent reduction in particle size, which has been promoted in the development of toners having high development characteristics, the coating amount of magnetic toner increases, and as a result, the above-described problems are further promoted, and the toner consumption is increased.

  In order to uniformly coat the magnetic one-component toner on the developing sleeve, in Patent Document 9, the ten-point average surface roughness of the surface of the developing sleeve, the magnetic permeability and average particle size of the toner, and the magnet roller carried in the sleeve An invention that defines the relationship with the magnetic force is disclosed. In this invention, the use of a roughened sleeve makes it possible to stabilize the coating amount and application state of the magnetic toner applied on the developing sleeve. Is not mentioned, and the apparatus configuration and idea in the present invention are essentially different. In addition, it is said that a developed image without image deterioration such as white streaks can be obtained. However, the magnetic toner of the present invention may be insufficient in terms of durability stability and environmental stability.

  As described above, even when applied to a high-speed development system using a high-capacity cartridge with a high process speed, it has excellent durability stability, environmental stability, and high developability. In order to realize a magnetic toner and a process cartridge that can obtain a quality image and suppress the occurrence of blotches, scattering, fogging, and photoconductor scratches, there is still room for further study.

Japanese Patent Laid-Open No. 2004-4751 JP 2004-12542 A JP 2000-330376 A Japanese Patent Laid-Open No. 06-186838 JP 2004-117996 A Special Registration No. 2986343 JP 2004-94138 A JP 2004-117919 A Japanese Laid-Open Patent Application No. 08-137252

  An object of the present invention is to provide a magnetic toner that solves the above-described problems.

  That is, the object of the present invention is to reduce the image quality such as blotch and fog, and to improve the developability even when using a large capacity process cartridge in which the process speed is increased or the toner filling amount in the developing device is increased. It is an object to provide a magnetic toner, an image forming method and a process cartridge which can suppress a decrease, a photoreceptor damage, and scattering of the magnetic toner in the machine, have excellent durability stability and excellent dot reproducibility.

As a result of intensive studies, the present inventors have at least a magnetic toner containing a binder resin and a magnetic material.
A toner consisting of a cylindrical developing sleeve rotatably supported in the developing container from the developing container containing the magnetic toner, and a magnet roller having a plurality of magnetic poles in the developing sleeve and arranged non-rotatingly Used in an image forming method in which the magnetic toner is conveyed by a carrier, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. The area ratio of the magnetic toner to the entire contact portion when the surface of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 0.10. The ten-point average roughness Rz measured with a laser microscope on the surface of the portion of the toner regulating blade that is in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less. The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic roller magnetic field is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact, and the magnetic toner has a magnetic permeability of 0. When the saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg) within a range of 6 μH / m to 1.2 μH / m, and exhibits a magnetization value corresponding to 95% of σs. It was found that the object of the present invention can be achieved by using a magnetic toner characterized by satisfying 135 <H95% <200 when the strength of the magnetic field is H95% (kA / m), The present invention has been completed.

That is, the present invention relates to a cylindrical developing sleeve that is rotatably supported in a developing container from a developing container that contains toner, and a magnet that has a plurality of magnetic poles in the developing sleeve and is arranged in a non-rotating manner. Image formation in which the magnetic toner is conveyed by a toner carrier comprising a roller, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. A magnetic toner used in a method,
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
The present invention relates to a magnetic toner characterized by satisfying

The present invention also provides a cylindrical developing sleeve that is rotatably supported in a developing container from a developing container that contains toner, and a magnet that has a plurality of magnetic poles in the developing sleeve and is arranged in a non-rotating manner. Image formation in which the magnetic toner is conveyed by a toner carrier comprising a roller, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. A method,
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
The present invention relates to an image forming method.

Furthermore, the present invention provides a cylindrical developing sleeve that is rotatably supported in a developing container from a developing container that contains toner, and a magnet that has a plurality of magnetic poles in the developing sleeve and is arranged in a non-rotating manner. Image formation in which the magnetic toner is conveyed by a toner carrier comprising a roller, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. A process cartridge for use in a method,
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
The present invention relates to a process cartridge.

  According to the magnetic toner of the present invention, even when a large-capacity process cartridge in which the process speed is increased or the amount of magnetic toner filled in the developing device is increased, blotch, fogging, magnetic toner into the machine is used. Scattering and occurrence of photoconductor scratches can be suppressed. Further, the dot reproducibility is excellent, a low toner consumption can be achieved, and the durability stability is excellent.

  In the present invention, the ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less. The ratio of the area of the contact portion to the area of the non-contact portion when the portion that is in contact with the toner carrier and the glass plate is contacted at a surface pressure of 14.4 Pa is 8/92 to 70/30. is important.

  In the present invention, the ten-point average roughness Rz and the average spacing Sm of the surface of the portion of the toner regulating blade that contacts the toner carrier, the portion of the toner regulating blade that contacts the toner carrier, and the glass plate The ratio of the area of the contact part to the area of the non-contact part when the surface pressure is contacted at a surface pressure of 14.4 Pa is measured by a non-contact measurement method using a laser microscope (VK-8500, manufactured by Keyence Corporation).

  In many conventional inventions, a contact-type surface roughness measuring device is used to adjust the surface roughness of the toner layer thickness regulating member. In contact-type measurement, the tip radius of the stylus is determined according to the measurement force, but the tip radius may be affected by the shape of the irregularities on the surface of the toner regulating blade. However, different cross-sectional curves may be obtained due to the difference in tip radius. The surface roughness adjustment method using a contact-type measuring device is strict about the vertical direction and the planar direction of the unevenness, especially when the density of the unevenness in the planar direction is relatively higher than the roughness in the vertical direction. It was difficult to adjust to the desired surface properties defined.

  Below, the specific example of the non-contact measuring method in this invention is shown.

<Measuring method of ten-point average roughness Rz and average interval Sm of unevenness of toner regulating blade surface>
1) Preparation of sample Cut the toner regulating blade into a size of about 1 cm square. However, as long as there is a sufficient area for irradiating the laser in the observation with a laser microscope, the size to be cut is not particularly limited.

2) Measurement conditions Set parameters for measurement as follows.
Objective lens magnification: 20 × Optical zoom magnification: 1 × Digital zoom magnification: 1 × RUN MODE: Color super depth LASER (gain): 594
LASER (offset): -1328
Camera settings (shutter): 158
Camera setting (white balance): 3200k
Camera setting (gain): 0

3) Setting of the sample The cut toner regulating blade is set on the stage of the laser microscope so that the portion in contact with the toner carrier becomes the observation surface.

4) Measurement The surface of the toner regulating blade is measured with a measurement PITCH of 0.1 μm.

5) Image processing In order to correct the overall distortion and inclination of the image obtained by the measurement, the following processing was performed.

[1. Tilt correction]
Correction method: Surface correction (automatic)
Process target: Height The following process was performed in order to remove fine noise components in the image obtained by the measurement.

[2. Filter processing]
Process target: Smoothing (height data)
Size: 7x7
Number of executions: 1
File Type: Median

[3. Filter processing]
Process target: Smoothing (height data)
Size: 3x3
Number of executions: 1
File type: Simple average

6) Analysis Height data is used for analysis. A scale is drawn on the obtained height data image, a range of 200 μm × 260 μm is selected, and the ten-point average roughness Rz and the average interval Sm of the irregularities in this range are used as measurement results.

[Ten point average roughness Rz]
The value obtained in the surface roughness measurement mode.

[Average interval Sm of unevenness]
In line roughness measurement mode, draw 5 straight lines in any horizontal direction and 5 straight lines in any vertical direction, and 2 upper and lower limit values out of the average interval Sm of 10 irregularities obtained from a total of 10 straight lines And the average of the remaining 8 points.

<Measurement Method of Ratio of Area of Contact Part and Area of Non-Contact Part When Contacting Part of Toner Regulation Blade with Toner Carrier and Glass Plate at Contact Pressure of 14.4 Pa>
In the developing device used for evaluating the toner of the present invention, as a method of simulating the state in which the toner regulating blade and the toner carrier are in contact with each other, the toner regulating blade is cut out and the toner regulating blade is actually used. A state when a load corresponding to the contact pressure was applied was created and observed. The method is shown below. The surface pressure of 14.4 Pa is a value corresponding to the most preferable surface pressure at the portion of the developing device that is in contact with the toner carrier of the toner regulating blade.

1) Preparation of sample [Preparation of observation sample]
A portion of the cut toner regulating blade that is in contact with the toner carrier is placed on the upper side, and a glass plate is placed thereon. At this time, the center of gravity of the toner regulating blade and the glass plate are made to coincide. Furthermore, the same weight is placed on both sides of the glass plate. The positions of the respective weights are symmetrical with respect to the center of gravity of the toner regulating blade and the glass plate, and do not disturb the approach of the objective lens when observing the toner regulating blade.

[Toner control blade]
Cut the toner regulating blade precisely to a size of 0.8 cm square.

[Glass plate]
The glass plate preferably has a smooth surface. In particular, a slide glass (thickness: 0.9 to 1.2 mm, 76 × 26 mm, manufactured by Matsunami Glass Co., Ltd.) is more preferably used in this measurement.

[Weight for load]
In this measurement, the portion of the toner regulating blade that is in contact with the toner carrier is brought into contact with the glass plate at a surface pressure of 14.4 Pa. To bring the glass plate into contact with the 0.8 cm square toner regulating blade at a surface pressure of 14.4 Pa, a load of 147 g is required. A weight is prepared so that the total of the mass of a glass plate and two weights of the same mass becomes 147 g. Any weight can be used. In this measurement, it is preferable to add a powder having a high specific gravity or water to a sample bottle to create a weight with a desired mass. It is preferable to use iron powder for powder having a large specific gravity. It is preferable to use a screw vial (SV-30 outer diameter: 30 mm, height: 65 mm, wall thickness: 1.5 mm, mouth inner diameter: 19.8 mm, capacity: 30 ml, manufactured by Nidec Rika Glass Co., Ltd.) for the sample bottle.

2) Measurement conditions Set parameters for measurement as follows.
Objective lens magnification: 20 × Optical zoom magnification: 1 × Digital zoom magnification: 1 × RUN MODE: Color super depth LASER (gain): 594
LASER (offset): -1328
Camera settings (shutter): 158
Camera setting (white balance): 3200k
Camera setting (gain): 0

3) Setting of sample A 0.8 cm square toner regulating blade with a load applied is set on the stage of the laser microscope so that the portion in contact with the toner carrier becomes the observation surface.

4) Measurement The measurement is performed so that the contact surface of the toner regulating blade surface and the glass plate is included with a PITCH of 0.1 μm.

5) Image processing In order to correct the overall distortion and inclination of the image obtained by the measurement, the following processing was performed.

[1. Tilt correction]
Correction method: Surface correction (automatic)
Process target: Height The following process was performed in order to remove fine noise components in the image obtained by the measurement.

[2. Filter processing]
Process target: Smoothing (height data)
Size: 7x7
Number of executions: 1
File Type: Median

[3. Filter processing]
Process target: Smoothing (height data)
Size: 3x3
Number of executions: 1
File type: Simple average

6) Analysis Height data is used for analysis. In the obtained height data image, the contact portion between the toner regulating blade and the glass plate is clearly displayed in black with respect to the non-contact portion (FIG. 1). By binarizing the area of the contact portion and the non-contact portion due to the difference in color, when the portion of the toner regulating blade that is in contact with the toner carrier is brought into contact with the glass plate at a surface pressure of 14.4 Pa, The ratio of the area of the contact part and the area of the non-contact part can be calculated. As a method for binarizing the areas of the contact part and the non-contact part, an application having an image analysis function is preferably used. As an application, for example, “Image-Pro Plus (Media Cybernetics)” is used. In binarizing the areas of the contact part and the non-contact part, the following operation is performed in order to remove minute noise from the obtained image and to obtain a more accurate value.

By removing the histogram that is in the range of 0 to 255 in the color extraction process from 0 to 60, very minute noise is removed. By this operation, the contact portion and the non-contact portion can be divided into two colors.
・ Calculate the total contact area of the contact area by measuring the area of the measurement item.
The area ratio between the contact part and the non-contact part is calculated from the area of the entire image and the total area of the contact part.

  The ten-point average roughness Rz measured with a laser microscope is 5.0 μm or more and 25.0 μm or less, and the portion of the toner regulating blade that is in contact with the toner carrier is brought into contact with the glass plate at a surface pressure of 14.4 Pa. When the ratio of the contact area to the non-contact area is 8/92 to 70/30, an appropriate amount of toner stays in the nip portion between the toner regulating blade and the toner carrier. It is possible to form short and uniform toner spikes.

  In the present invention, by controlling the magnetic flux density at the nip portion of the developing sleeve, which is the toner regulating blade and the toner carrying member, and the magnetic characteristics of the toner, the nip portion is always in an appropriate amount while the staying toner is appropriately replaced. Think that you will be able to exist.

  As described above, since the appropriate staying toner is always present while being replaced by the nip portion, when the toner passes through the nip, the toner that is directly rubbed with the toner regulation blade and charged is rubbed with the staying toner, and thus excessively charged. Therefore, it is easy to obtain uniform images with no unevenness in density such as blotch.

  Further, high-developable toners for the purpose of improving image quality in recent years tend to be difficult to coat a thin layer on a toner carrier, but by using the above-mentioned toner regulating blade, a better image can be obtained. Is possible. This is probably because the presence of an appropriate immobile toner in the nip portion causes a uniform high regulation force in the longitudinal direction on the toner carrier, so that the toner coat layer is thin and stable.

  When the ten-point average roughness Rz measured with a laser microscope is less than 5.0 μm, the toner does not stay easily in the nip portion, so the amount of staying toner tends to be small, and the toner passing through the nip can be separated from the toner regulating blade. The chance of direct friction increases, and even when the toner of the present invention is used, the toner may be fused to the toner regulating blade. In addition, the regulation force tends to be weakened. In this case, the toner coat layer on the toner carrier is thickened, and the toner charge distribution is broadened, resulting in the occurrence of blotches, the density of solid black images, or the fineness of the images. There is a tendency to decrease.

  On the other hand, if the particle size is larger than 25.0 μm, excessive toner stays in the nip portion, and the regulating force becomes too strong, so that the toner is likely to be charged up, or in the second half of the endurance, the density decreases due to toner deterioration. And image defects such as density unevenness.

  On the other hand, in the present invention, the ratio of the area of the contact portion and the area of the non-contact portion when the portion of the toner regulating blade that is in contact with the toner carrier and the glass plate is brought into contact with the surface pressure of 14.4 Pa is as follows. It is important that the ratio is 8/92 to 70/30. However, if the ratio of the contact area to the non-contact area is less than 8/92, excessive toner stays in the nip area. It is easy to cause the above problems.

  On the other hand, if the ratio is larger than 70/30, the amount of staying toner tends to decrease, and the above-described problem is likely to occur.

  In addition, the average spacing Sm of the unevenness measured with a laser microscope on the surface of the toner regulating blade on the side in contact with the toner carrier is 5.0 μm or more and 200.0 μm or less, so that the amount of staying toner is appropriate. It is preferable to make it.

  Examples of the method for roughening the toner regulating blade in the present invention include a physical blasting method such as a sand blasting method, a shot blasting method, a method using a sand paper, and a chemical method such as etching. And a method of forming a film containing coarse particles.

  Among them, in the present invention, it is preferable to mold using a drum mold such as a centrifugal molding method or a continuous injection molding method. That is, in the process of injecting the toner regulating blade forming liquid into the mold and molding the toner regulating blade while rotating, the mold is rotating, so that the centrifugal force works and the air in the toner regulating blade forming liquid And the like, and the toner regulating blade forming liquid is pressed against the mold surface, so that it is possible to obtain a toner regulating blade in which the irregularities of the mold are accurately transferred without mixing air or the like. At this time, as a method for forming irregularities on the inner peripheral surface of the mold, a method of using a bead blast method with roughened particles on the mold surface, or a mold release layer on the inner peripheral surface of the mold, The surface layer part of the mold layer preferably contains a surface roughening treatment agent such as spherical fluorinated graphite, and the height (depth) and unevenness interval of the uneven parts are controlled by the particle size and content of the roughened particles. can do.

  For example, as shown in the model diagram of FIG. 2, the sheet 22 transferred from the die 21 bead-blasted with roughened particles has a convex shape with a smooth rounded arc shape, By adjusting the discharge pressure, the ratio (ratio) and depth (height) of the concave and convex portions can be controlled. On the other hand, as shown in the model diagram of FIG. 3, in the sheet 33 transferred from the mold surface 31 formed with the release layer 32 containing the roughening treatment agent, the convex portion is relatively flat. It becomes a shape and a recessed part can obtain a comparatively deep surface shape. Also in this case, the ratio (ratio) and depth (height) of a recessed part and a convex part are controllable by adjusting the particle size and content of a roughening processing agent. The toner layer thickness is regulated by configuring the toner regulating blade such that the uneven surface (mold surface) of the sheet thus obtained is on the contact surface side with the developing sleeve.

  The toner regulating blade member used in the present invention is not particularly limited. For example, urethane rubber, polyamide resin, polyamide elastomer, silicone rubber, silicone resin, and the like can be used, and urethane rubber is preferably used as the Rz described above. , Sm and the contact area ratio are preferable. The support member of the toner regulating blade is preferably made of a metal flat plate, a resin flat plate, more specifically, a stainless steel plate, a phosphor bronze plate, an aluminum plate, or the like. An additive such as a conductive material can be added to the main material of the blade member. In addition, the support member and the blade member can be bonded by, for example, an adhesive such as hot melt.

  When a rubber material is used as the toner regulating blade member, the rubber hardness is preferably 40 ° or more and 100 ° or less in (JIS) A in order to control the above-described contact area ratio. More preferably, (JIS) A 45 ° to 95 °, and still more preferably (JIS) A 50 ° to 90 °.

  If the rubber hardness is less than 40 °, the contact pressure with respect to the toner carrier tends to be insufficient, and the nip between the toner carrier and the toner regulating blade tends to become wider than necessary, causing toner deterioration to progress. sell. On the other hand, when the angle exceeds 90 °, the contact pressure becomes too high, which not only facilitates the fusion of the toner to the toner regulating blade, but also causes the toner to deteriorate, which is not preferable.

  In the present invention, the magnetic force (peak magnetic flux density) acting in the central direction of the developing sleeve is preferably 50 mT or more and 100 mT or less at the portion (nip portion) where the elastic blade and the developing sleeve abut. In order to form short and uniform spikes with magnetic toner, 70 mT or more and 86 mT or less is more preferable. When the peak magnetic flux density is more than 100 mT, the magnetic density of the magnetic toner having a low magnetic permeability causes a decrease in image density, and the magnetic toner having a high magnetic permeability causes uneven charging of the toner due to the formation of thick and long spikes or uneven spikes. And fogging. In addition, the toner deterioration becomes significant due to repeated excessive conveyance of the magnetic toner on the developing sleeve. When the peak magnetic flux density is less than 50 mT, the magnetic toner conveying force is low, so that the image density is lowered, and this is remarkable in a high-speed machine.

  The magnetic flux density in the center direction, that is, the normal direction on the surface of the developing sleeve was measured using a Gauss meter model 640 (manufactured by Bell). The developing sleeve was fixed horizontally, the magnet roller in the developing sleeve was rotatably attached, and the maximum magnetic flux density at the nip portion between the toner regulating blade and the developing sleeve on the surface of the developing sleeve was defined as the peak magnetic flux density.

  The diameter of the developing sleeve is appropriately selected from about Φ10 to about Φ30 depending on the machine speed. In general, the strength of the magnetic pole is appropriately determined depending on the balance between the machine speed, the developing sleeve diameter and the developing property of the magnetic toner. The In the magnetic toner of the present invention, the target effect of the present invention can be brought out by designing the peak magnetic flux density on the surface of the developing sleeve using the materials described later.

  The developing sleeve preferably used for carrying the magnetic toner of the present invention is preferably a conductive cylinder formed of a metal or alloy such as aluminum or stainless steel. A conductive cylinder may be formed of a resin composition having sufficient mechanical strength and conductivity, and a conductive rubber roller may be used.

  In particular, since the charging control of the magnetic toner is easy, the surface of the developing sleeve may be coated with a resin layer in which conductive fine particles and / or a lubricant are dispersed.

  Examples of the resin used for the resin layer include thermoplastic resins such as styrene resins, vinyl resins, polyethersulfone resins, polycarbonate resins, polyphenylene oxide resins, polyamide resins, fluororesins, fiber resins, and acrylic resins; Thermosetting resins or photocurable resins such as epoxy resins, polyester resins, alkyd resins, phenol resins, melamine resins, polyurethane resins, urea resins, silicone resins, and polyimide resins can be used.

  Among them, those having releasability such as silicone resin and fluorine resin, or mechanical properties such as polyethersulfone resin, polycarbonate resin, polyphenylene oxide resin, polyamide resin, phenol resin, polyester resin, polyurethane resin, styrene resin The thing excellent in is more preferable.

  As the conductive fine particles to be contained in the resin layer, conductive metal oxides such as carbon black, graphite, and conductive zinc oxide and metal double oxides are used alone or in combination of two or more.

  The surface roughness of the magnetic toner carrier (developing sleeve) used in the present invention is preferably in the range of 0.2 to 3.5 μm in terms of JIS centerline average roughness (Ra). When Ra is less than 0.2 μm, the amount of charge on the developing sleeve tends to be high, and the developability tends to be insufficient. When Ra exceeds 3.5 μm, unevenness occurs in the toner coat layer on the developing sleeve, and the density tends to be uneven on the image. More preferably, it is in the range of 0.2 to 3.0 μm. In the present invention, Ra is based on JIS surface roughness “JIS B 0601” and is measured using a surface roughness measuring instrument (Surfcoder SE-30H, manufactured by Kosaka Laboratory Co., Ltd.). It corresponds to.

  For example, Ra can be adjusted to the above range by changing the polishing state of the surface layer of the developing sleeve or adding spherical carbon particles, carbon fine particles, graphite or the like.

  The developing sleeve preferably has a fixed magnet having multiple poles and 3 to 10 poles.

  The magnetic toner of the present invention contains at least a binder resin and a magnetic material.

  The magnetic toner has a cylindrical developing sleeve (toner carrier) rotatably supported in the developing container from the developing container containing the magnetic toner, and a plurality of magnetic poles in the developing sleeve. The magnetic toner is conveyed by a developing sleeve composed of a rotating magnet roller, the toner layer thickness of the developing sleeve is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the developing sleeve. A magnetic toner used in an image forming method.

  The maximum magnetic permeability of the magnetic toner of the present invention is in the range of 0.6 μH / m or more and 1.2 μH / m or less from the viewpoint of the formation of spikes on the developing sleeve by the magnetic toner and charging. It is important in fulfilling the purpose.

The relationship between the magnetic flux density, the magnetic field, and the magnetic permeability μ is expressed by the following equation.
B = μ · H (2)

  In the above formula, B represents the magnetic flux density, and H represents the magnetic field. It can be seen that a material having a higher magnetic permeability exhibits a higher magnetization with respect to a constant magnetic field, and when the magnetic field is generated by a magnet, the material is strongly attracted to the magnet.

  When the maximum magnetic permeability of the magnetic toner is less than 5 μH / m, the magnetic toner regulating force at the contact portion between the toner regulating blade and the developing sleeve is larger than the magnetic toner conveying force due to the magnetic force of the magnetic roller of the developing sleeve. A uniform magnetic toner layer cannot be formed on the developing sleeve, and white streaks and magnetic toner are not uniformly charged, which causes blotches. On the other hand, if the maximum magnetic permeability of the magnetic toner is greater than 8 μH / m, the supply of the magnetic toner layer on the developing sleeve becomes excessive, causing fogging or low density due to poor charging of the magnetic toner.

  The value of the maximum magnetic permeability in the present invention can be measured using various measuring methods.

  As a method for directly measuring the magnetic toner or the magnetic material in powder form, for example, measurement can be performed using “vibrating sample type magnetometer VSM-3” (manufactured by Toei Kogyo Co., Ltd.) or the like. It can be obtained from a BH curve obtained by setting a predetermined amount of magnetic powder to be measured in the holder and setting the maximum applied magnetic field to 397.9 (kA / m). Also, a measurement method can be used in which a toroidal magnetic core is uniformly wound, an appropriate alternating magnetic field is applied, and an inductance change at that time is obtained.

  In addition, the value of the magnetic characteristic in this invention is the value measured on the environmental conditions of temperature 22.5 degreeC and humidity 50% RH.

  In order to set the maximum magnetic permeability to a predetermined value, a method of adjusting the magnetic permeability and the number of copies of the magnetic substance contained in the magnetic toner can be used. In addition, since the magnetic permeability changes also by adjusting the true density of the magnetic toner, a method of selecting a binder resin material contained in the magnetic toner is also included.

  Furthermore, in order to adjust the magnetic permeability of the magnetic substance contained in the magnetic toner, there is a method in which the magnetic material is subjected to known processing such as selection of a magnetic material, addition of a different metal, heat treatment, or treatment in a rotating magnetic field. It is done.

Further, the magnetic toner of the present invention, when the magnitude of the magnetic field is 397.9 kA / m, a saturation magnetization of the magnetic toner and σs (Am ² / kg), indicating a magnetization value corresponding to 95% of [sigma] s When the strength of the magnetic field is H95% (kA / m), the following formula is satisfied.
135 <H95% <200 (1)

  The magnetic properties of the magnetic toner and the magnetic material can be measured using a magnetometer such as “vibrating sample magnetometer VSM-3S-15” (manufactured by Toei Kogyo Co., Ltd.), as with the magnetic permeability.

  In the jumping development method, an electric field generated by a voltage that causes the magnetic toner to fly to the photosensitive member and a voltage in a pulling-back direction between the magnetic toner carrier (developing sleeve) that is a charge imparting member and the photosensitive member (developing nip). In addition to the action and the magnetic attractive force due to the magnetic binding force of the magnetic toner carrier, the magnetic attractive force and gravity of the magnetic toners work, and the magnetic toner that reaches the photosensitive member is distributed by these balances.

  The magnetic toner on which the spikes are formed on the magnetic toner carrier generally passes through the development nip while leaving some spike shape.

  At this time, if the shape of the spike is thick and long, the height of toner on the photoconductor becomes high, and the fixed image tailing tends to deteriorate, resulting in a decrease in fine line reproducibility and an increase in toner consumption. Tend to. In particular, when the transfer residual toner has a certain amount of applied height, it is easily rubbed by the cleaning blade, and the photoconductor scratches easily occur. On the magnetic toner carrier, the magnetic toner inside the ears is not sufficiently charged, and image quality problems such as fogging and blotches due to charging defects such as uneven charging, and scattering due to development of thick ears are likely to occur. .

  On the other hand, if the magnetic toner in the development nip hardly forms a spike shape or is partially formed due to weak magnetic attraction, the toner loading height on the photosensitive member becomes low. In addition, there are cases where it is advantageous in terms of fixed image tailing and toner consumption. However, especially when the process speed increases or the toner charge distribution increases after long-term durability using a large-capacity cartridge, magnetic regulation between magnetic toners by forming an appropriate spike shape is not possible. If it does not work, image quality is likely to deteriorate, such as fogging due to charged toner and a decrease in dot reproducibility.

  As a result of repeated studies of directly observing the development behavior of the magnetic toner in the development nip as described above, the present inventors have found that a magnetic toner having specific magnetic characteristics is suitable for achieving the object of the present invention. It has been found that it shows a good development form. The inventors control not only the more macroscopic magnetic characteristics such as saturation magnetization and residual magnetization obtained from the hysteresis loop of the magnetic toner, but also the gradient of the magnetization curve represented by the maximum permeability and further the value of H95%. Has been found to be important in achieving the object of the present invention. Specifically, it has been found that it is important to control the value of H95% within the range of the above formula (1). It has been found that the value of H95% can be controlled within the range of the above formula (1) by making the magnetic properties of the individual magnetic toner particles more uniform. By combining such a magnetic toner and a developing sleeve, which is a toner carrier that exhibits a magnetic force in a predetermined range, with the above-described toner regulating blade, durability stability, environmental stability, It is possible to provide a magnetic toner having excellent developability, an image forming method, and a process cartridge. That is, a ten-point average roughness, a contact ratio when a glass plate is brought into contact with a predetermined surface thickness, a ratio of specific contact area, and a predetermined range of irregularities on the surface indicated by an average interval of irregularities. By using the blade having the above, uniform-sized spikes are formed on the magnetic toner carrier, and the magnetic toner on the carrier is uniformly charged, and the development nip portion is also relatively thin and short uniformly. It has been found that development is carried out while maintaining the size of the spike.

  A relationship between the magnetic field (H) and the magnitude of magnetization of the entire magnetic material (M) when a magnetic field is applied to the magnetic material is an MH curve (hysteresis loop), which is shown in FIG. The first state before adding H is O, and this state of H = 0 and M = 0 is called a demagnetization state. As H is added, M increases and reaches saturation (A). This rising curve is called the initial magnetization curve, and the magnetization when saturated is the saturation magnetization (σs). The rate of increase in magnetization when a magnetic field is applied is called magnetic susceptibility. Even if H is decreased from the saturation state, M does not return to 0, but reaches the B state of H = 0, and the magnetization of OB remains. This is called residual magnetization (σr). If the magnetic field is further increased in the opposite direction, M decreases and becomes C. At this time, the magnetic field of OC is called coercive force (Hc). Furthermore, increasing the negative magnetic field will reach D and saturate in the opposite direction. When the positive magnetic field is increased again, A is reached through E, and a hysteresis loop as shown is drawn.

  In the present invention, the residual magnetization (σr) and the coercive force (Hc) are obtained by drawing the hysteresis loop as shown in FIG. 5 with the magnetization value at the external magnetic field of 397.9 kA / m as the saturation magnetization (σs). It was.

  As shown in FIG. 5, H95% means a magnetic field when showing a magnetization value of 95% of the saturation magnetization when H is decreased and demagnetized after reaching the saturation magnetization via the initial magnetization curve. Represents the strength of

  In the magnetic toner as a whole, the magnetic properties of the individual magnetic toner particles are different from each other, and are considered to be distributed in different magnetic property values. Such a distribution of magnetic properties is presumed to be caused by, for example, the amount of magnetic material in individual magnetic toner particles being greatly different or the magnetic properties of the magnetic particles themselves being non-uniform. When this distribution is wide, H95% tends to be relatively high, and it becomes difficult to obtain the effect intended by the present invention.

  If the magnetic properties of the magnetic toner particles are not uniform, the value of H95% tends to be large, especially when it is 200 kA / m or more, it tends to be thick and not uniform in the spike shape, as described above. It is easy to cause bad image quality. In addition, if the magnetic properties of the magnetic toner particles are not uniform, the magnetic properties of the individual toners are likely to vary greatly even if the dispersibility of the magnetic material in the toner is improved, and problems such as fogging worsen. Cheap. In the present invention, H95% is more preferably smaller than 170.

  On the other hand, when the value of H95% is 135 or less, Hc also tends to decrease at the same time. In order to increase Hc, it is possible to control by composition so as to increase σs. However, increasing σs increases the magnetic cohesive force, so that the ears tend to be thick and the toner enters the toner. It is not preferable because good dispersion is difficult to achieve. H95% is more preferably larger than 140.

  The magnetic toner of the present invention has the magnetic characteristics as described above. In general, the magnetic properties of the magnetic material contained in the magnetic toner can be adjusted by, for example, the type and number average particle diameter of the magnetic material, and the type and amount of the non-magnetic material compounded in the magnetic material. In the magnetic toner of the present invention, in particular, as described in detail below, by controlling the number average particle size, particle size distribution, and surface properties of the magnetic material, the magnetic properties of the individual magnetic particles are made uniform, By uniformly dispersing in the magnetic toner, the magnetic properties of the magnetic toner can be adjusted to a specific range.

  In order to produce the magnetic toner of the present invention, a mixture containing at least a binder resin and a magnetic material is used as a material. In addition, a wax, a charge control agent, an inorganic fine powder, and a hydrophobic inorganic fine powder are used as necessary. In addition, other additives such as known colorants are used.

  As the types of binder resins used in the present invention, styrene resins, styrene copolymer resins, polyester resins, polyol resins, polyvinyl chloride resins, phenol resins, natural modified phenol resins, natural resin modified maleic resins, Examples thereof include acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, and petroleum resin.

  As a comonomer for the styrene monomer of the styrene copolymer, a styrene derivative such as vinyltoluene; acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, acrylic Acrylic acid ester such as phenyl acid; Methacrylic acid ester such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate; Maleic acid; Double such as butyl maleate, methyl maleate, dimethyl maleate Dicarboxylic acid ester having a bond; acrylamide, acrylonitrile, methacrylonitrile, butadiene; vinyl ester such as vinyl chloride, vinyl acetate, vinyl benzoate; ethylene, propylene, butylene Such ethylenic olefins, vinyl methyl ketone, such as vinyl vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl propionate ether. These vinyl monomers are used alone or in combination of two or more.

  In the present invention, styrene-acrylic acid ester-acrylic acid copolymer, styrene-acrylic acid ester copolymer, and styrene-acrylic acid ester-methacrylic acid copolymer are used as particularly preferable binder resins.

  Examples of the polymerization method of the binder resin of the present invention include a solution polymerization method, an emulsion polymerization method and a suspension polymerization method.

  The binder resin used in the present invention is preferably produced by using a polyfunctional polymerization initiator alone or in combination with a monofunctional polymerization initiator as exemplified below.

  Specific examples of the polyfunctional polymerization initiator having a polyfunctional structure include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,3-bis- (t-butylperoxy Isopropyl) benzene, 2,5-dimethyl-2,5- (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, tris- (t-butyl) Peroxy) triazine, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane, 4,4-di-t-butylperoxyvaleric acid-n-butyl ester , Di-t-butylperoxyhexahydroterephthalate, di-t-butylperoxyazelate, di-t-butylperoxytrimethyladipate, 2,2-bis- ( , 4-di-t-butylperoxycyclohexyl) propane, 2,2-t-butylperoxyoctane and functional groups having a polymerization initiation function such as two or more peroxide groups in one molecule of various polymer oxides. A polyfunctional polymerization initiator having a peroxide group in one molecule such as diallyl peroxydicarbonate, t-butylperoxymaleic acid, t-butylperoxyallylcarbonate and t-butylperoxyisopropyl fumarate. Such a polyfunctional polymerization initiator having both a functional group having a polymerization initiating function and a polymerizable unsaturated group is selected.

  Of these, more preferred are 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, di-t-butylperoxy. Hexahydroterephthalate, di-t-butylperoxyazelate, 2,2-bis- (4,4-di-t-butylperoxycyclohexyl) propane, and t-butylperoxyallyl carbonate.

  These polyfunctional polymerization initiators are preferably used in combination with a monofunctional polymerization initiator in order to satisfy various performances required as a binder for toner. In particular, it is preferable to use in combination with a polymerization initiator having a half-life of 10 hours lower than the decomposition temperature for obtaining a half-life of 10 hours of the polyfunctional polymerization initiator.

  Specifically, benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, n-butyl-4,4-di (t-butylperoxy) valerate, dichroic Organic peroxides such as milperoxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t-butylperoxide; azobisisobutyronitrile, diazoamino Examples include azo and diazo compounds such as azobenzene.

  These monofunctional polymerization initiators may be added to the monomer at the same time as the polyfunctional polymerization initiator, but in order to keep the efficiency of the polyfunctional polymerization initiator appropriate, in the polymerization step, It is preferably added after the half-life indicated by the polyfunctional polymerization initiator has elapsed.

  These polymerization initiators are preferably used in an amount of 0.05 to 2 parts by mass with respect to 100 parts by mass of the monomer from the viewpoint of efficiency.

  It is also preferable that the binder resin is crosslinked with a crosslinking monomer.

  As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is mainly used. Specific examples include aromatic divinyl compounds (eg, divinylbenzene, divinylnaphthalene, etc.); diacrylate compounds linked by alkyl chains (eg, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4 -Butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and acrylates of the above compounds replaced with methacrylate); alkyl chain containing an ether bond Diacrylate compounds (eg, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, Ethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and acrylates of the above compounds in place of methacrylate); diacrylate compounds linked by a chain containing an aromatic group and an ether bond (eg, polyoxyethylene) (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate, and methacrylates of the above compounds Furthermore, polyester-type diacrylate compounds (for example, trade name MANDA (Nippon Kayaku)) are mentioned. As polyfunctional crosslinking agents, pentaerythritol acrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds are replaced with methacrylate. Triallyl cyanurate, triallyl trimellitate; and the like.

  These crosslinking agents are preferably used in the range of 0.00001 to 1 part by mass, preferably 0.001 to 0.05 part by mass, with respect to 100 parts by mass of the other monomer components.

In the present invention, it is more preferable to contain a bond formed by a reaction between a carboxyl group and an epoxy group as a crosslinked structure. The epoxy group in the present invention is a functional group in which an oxygen atom is bonded to different carbon atoms in the same molecule to form a cyclic ether structure.
Examples of the monomer having an epoxy group that can be used in the present invention include the following.

  Examples include glycidyl acrylate, glycidyl methacrylate, β-methyl glycidyl acrylate, β-methyl glycidyl methacrylate, allyl glycidyl ether, and allyl β-methyl glycidyl ether. Moreover, the glycidyl monomer represented by General formula (1) is used preferably.

  The bond formed by the reaction between the carboxyl group and the epoxy group is, for example, when a compound having a glycidyl group as an epoxy group is used.

（Ｒ₁、Ｒ₂及びＲ₃は、水素原子、又は、アルキル基、アリール基、アラルキル基、カルボキシル基及びアルコシキカルボニル基からなるグループより選ばれる官能基を示す。）
となり、架橋構造を形成するものである。

(R ₁ , R ₂ and R ₃ represent a hydrogen atom or a functional group selected from the group consisting of an alkyl group, an aryl group, an aralkyl group, a carboxyl group and an alkoxycarbonyl group.)
Thus, a crosslinked structure is formed.

  In the present invention, as means for obtaining a vinyl resin having a bond formed by a reaction between a carboxyl group and an epoxy group as a crosslinked structure, 1) a vinyl resin having a carboxyl group and a vinyl resin having an epoxy group in a solution state. Mix and cause a crosslinking reaction by applying heat in the reaction kettle. 2) Take out the vinyl resin having carboxyl group and the vinyl resin having epoxy group from the reaction kettle, respectively, and dry blend with a Henschel mixer. A reaction between a carboxyl group and an epoxy group may be caused to crosslink by hot melt kneading with a biaxial extruder or the like. Similarly, when a vinyl resin having a carboxyl group and an epoxy group is used, the carboxyl group and the epoxy group can be reacted by hot melt kneading with a biaxial extruder or the like.

  The vinyl resin having an epoxy group is preferably used in an amount of 0.03 or more and 1 equivalent or less, preferably 0.03 or more and 0.5 equivalent or less, per 1 equivalent of a carboxyl group.

  As a method for producing a binder resin composition, a high-molecular weight polymer and a low-molecular weight polymer are separately synthesized by a solution polymerization method, mixed in a solution state, and then desolvated, and an extruder. The resin composition is prepared by dissolving in a monomer constituting a high molecular weight polymer obtained by dissolving a low molecular weight polymer obtained by a melt blending method such as a melt blending method, a solution polymerization method, etc., and performing suspension polymerization, washing and drying. And a two-stage polymerization method for obtaining However, the dry blend method has a point to be improved in terms of uniform dispersion and compatibility. The two-stage polymerization method has many advantages such as uniform dispersibility, but the low molecular weight can be increased to higher than the high molecular weight, and a high molecular weight polymer with a large molecular weight can be synthesized. The solution blending method is most suitable because there are few problems that coalescence is formed as a by-product. In addition, when a predetermined acid value is introduced into the low molecular weight polymer component, solution polymerization in which the acid value can be easily set as compared with the polymerization method using an aqueous medium is preferable.

  Examples of the composition of the polyester resin used as the binder resin in the present invention are shown below.

  Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, and bisphenol represented by formula (A) and derivatives thereof;

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ及びｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０〜１０である。）
式（Ｂ）で示されるジオール類；

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
Diols represented by formula (B);

  Divalent acid components include benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or anhydrides thereof, lower alkyl esters; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid. Or an anhydride or a lower alkyl ester thereof; an alkenyl succinic acid or an alkyl succinic acid such as n-dodecenyl succinic acid or n-dodecyl succinic acid, or an anhydride or a lower alkyl ester thereof; fumaric acid, maleic acid, citraconic acid, itacone Examples thereof include unsaturated dicarboxylic acids such as acids or anhydrides thereof, or lower alkyl esters;

  Moreover, it is preferable to use together the trihydric or more alcohol component and trivalent or more acid component which work as a crosslinking component.

  Examples of the trihydric or higher polyhydric alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene, etc. Can be mentioned.

  The trivalent or higher polyvalent carboxylic acid component in the present invention includes trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7. -Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxy Propane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, empole trimer acid, and their anhydrides, lower alkyl esters;

（式中、Ｘは炭素数３以上の側鎖を１個以上有する炭素数５〜３０のアルキレン基又はアルケニレン基である。）
で表わされるテトラカルボン酸、及びこれらの無水物、又は低級アルキルエステルの如き多価カルボン酸類及びその誘導体が挙げられる。

(In the formula, X is an alkylene group or alkenylene group having 5 to 30 carbon atoms having one or more side chains having 3 or more carbon atoms.)
And polycarboxylic acids such as tetracarboxylic acids and their anhydrides or lower alkyl esters and derivatives thereof.

  The alcohol component is 40 to 60 mol%, preferably 45 to 55 mol%, and the acid component is 60 to 40 mol%, preferably 55 to 45 mol%.

  Moreover, it is preferable that the polyvalent component more than trivalence is 5-60 mol% in all the components. The polyester resin can also be obtained by a generally known condensation polymerization.

  In the present invention, the binder resin preferably has an acid value, more preferably, the acid value of the binder resin is 1 to 50 mgKOH / g, more preferably the acid value is 1 to 40 mgKOH / g, and still more preferably. The acid value may be 1 to 30 mgKOH / g for controlling the adhesive force.

  When the acid value of the binder resin is less than 1 mgKOH / g, the chargeability of the toner becomes insufficient, the developability tends to deteriorate, and the staying toner tends to decrease. On the other hand, if it exceeds 50 mgKOH / g, the moisture absorption of the binder resin tends to increase, and the chargeability of the toner may become unstable.

The acid value of the binder resin is determined, for example, by the operations 1) to 5) below. The basic operation belongs to JIS K0070.
1) The sample is used by removing additives other than the binder resin (polymer component) in advance, or the content of components other than the binder resin in the sample is obtained. Weigh accurately 0.5 to 2.0 g of the pulverized product of magnetic toner or binder resin. The mass of the binder resin component at this time is defined as W (g).
2) A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (4/1) is added and dissolved.
3) Using an ethanol solution of 0.1 mol / l KOH, measurement is performed using a potentiometric titrator. For this titration, for example, an automatic titration using a potentiometric titration measuring device AT-400 (winworkstation) of Kyoto Electronics Co., Ltd. and an ABP-410 electric burette can be used.
4) The amount of KOH solution used at this time is S (ml). At the same time, a blank is measured, and the amount of KOH used at this time is defined as B (ml).
5) Calculate the acid value according to the following formula. In the following formula, f is a factor of KOH.
Acid value (mgKOH / g) = {(SB) × f × 5.61} / W

  The waxes used in the present invention include the following. For example, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, aliphatic hydrocarbon wax such as Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax Or block copolymers thereof; plant waxes such as candelilla wax, carnauba wax, wax wax, jojoba wax; animal waxes such as beeswax, lanolin, spermaceti; mineral waxes such as ozokerite, ceresin, petrolatum Waxes based on aliphatic esters such as montanic acid ester wax and caster wax; those obtained by partially or fully deoxidizing aliphatic esters such as deoxidized carnauba wax

  Further, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, parinaric acid; stearyl alcohol Saturated alcohol such as eicosyl alcohol, behenyl alcohol, cannavir alcohol, seryl alcohol, melyl alcohol, or alkyl alcohol having a long chain alkyl group; polyhydric alcohol such as sorbitol; linoleic acid amide, oleic acid amide, lauric acid Aliphatic amides such as acid amides; saturated aliphatic bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amides, ethylene bislauric acid amides, hexamethylene bisstearic acid amides; Unsaturated fatty acid amides such as inamide, hexamethylenebisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, Aromatic bisamides such as N'-distearylisophthalamide; aliphatic metal salts such as calcium stearate, calcium laurate, zinc stearate and magnesium stearate (commonly referred to as metal soap); aliphatic hydrocarbons Wax grafted with a vinyl monomer such as styrene or acrylic acid; Partial esterified product of fatty acid and polyhydric alcohol such as behenic acid monoglyceride; Hydroxyl group obtained by hydrogenating vegetable oil Methyl ester compounds It is.

  In addition, these waxes have a sharp molecular weight distribution using a press perspiration method, a solvent method, a recrystallization method, a vacuum distillation method, a supercritical gas extraction method or a melt liquid crystal deposition method, a low molecular weight solid fatty acid, a low A molecular weight solid alcohol, a low molecular weight solid compound, and other impurities are preferably used.

  The amount of these waxes used is preferably 1.0 to 20.0 parts by mass per 100 parts by mass of the binder resin from the viewpoints of developability and releasability.

  Moreover, in this invention, it is preferable to add and use a charge control agent. The charging property of the magnetic toner of the present invention may be positive or negative. However, since the binder resin itself has a high negative charging property, it is preferably a negatively charging toner.

  Specific examples of the negative charge control agent include metal complexes of monoazo dyes described in JP-B-41-20153, JP-B-44-6397, JP-B-45-26478, and the like. Nitrohumic acid and its salts described in JP-A-50-133838 or C.I. I. Dyes and pigments such as 14645, salicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, described in JP-B-55-42752, JP-B-58-41508, JP-B-59-7385, etc. Examples thereof include metal complexes such as Cr, Fe and Zr, sulfonated copper phthalocyanine pigments, nitro oligomers, styrene oligomers introduced with halogen, and chlorinated paraffins. Among them, the azo metal complex represented by the general formula (I) and the basic organic acid metal represented by the general formula (II) are particularly excellent in dispersibility and effective in reducing the image density stability and fogging. Complexes are preferred.

In general formula (I), M represents a coordination center metal and represents Cr, Co, Ni, Mn, Fe, Ti, or Al. Ar is an aryl group such as a phenyl group or a naphthyl group, and may have a substituent. In this case, examples of the substituent include a nitro group, a halogen group, a carboxyl group, an anilide group, an alkyl group having 1 to 18 carbon atoms, and an alkoxy group having 1 to 18 carbon atoms. X, X ′, Y, and Y ′ are —O—, —CO—, —NH—, and —NR— (R represents an alkyl group having 1 to 4 carbon atoms). A ⁺ represents hydrogen, sodium ion, potassium ion, ammonium ion or aliphatic ammonium ion.

In general formula (II), M represents a coordination center metal and represents Cr, Co, Ni, Mn, Fe, Ti, Zr, Zn, Si, B, or Al. (B) may have a substituent such as an alkyl group, the following structural formula (1), the following general formulas (2) to (5), the following structural formula (6), and the following general formula (7), It represents one of (8) and may be the same or different. A ′ ⁺ represents a hydrogen ion, a sodium ion, a potassium ion, an ammonium ion, or an aliphatic ammonium ion. Z represents -O- or any one of the following structural formula (9), and may be the same or different.

  In the general formulas (2) to (5), X represents a hydrogen atom, a halogen atom, or a nitro group. In the general formulas (7) and (8), R represents a hydrogen atom, a C1 to C18 alkyl group, or a C2 to C18 alkenyl group.

  Among them, the azo metal complex represented by the above general formula (I) is more preferable, and the azo iron complex represented by the following general formula (III) or (IV) whose central metal is Fe is particularly preferable.

In general formula (III), X ₂ and X ₃ represent a hydrogen atom, a lower alkyl group, a lower alkoxy group, a nitro group or a halogen atom, k and k ′ represent an integer of _{1 to 3} , Y ₁ and Y ₃ Is a hydrogen atom, a C1-C18 alkyl group, a C2-C18 alkenyl group, a sulfonamide group, a mesyl group, a sulfonic acid group, a carboxyester group, a hydroxy group, a C1-C18 alkoxy group, an acetylamino group, a benzoyl group, An amino group or a halogen atom, l and l ′ represent an integer of 1 to 3, Y ₂ and Y ₄ represent a hydrogen atom or a nitro group, A ″ ⁺ represents an ammonium ion, a sodium ion, a potassium ion, a hydrogen ion Or a mixed ion thereof, preferably having an ammonium ion of 75 to 98 mol%, wherein X ₂ and X ₃ , k and k ′, Y ₁ and Y ₃ , l and l ′, and Y ₂ and Y ₄ may be the same or different.

In the general formula (IV), R _{1 to} R ₂₀ each represent a hydrogen atom, a halogen atom, or an alkyl group, which may be the same or different, and A ⁺ represents an ammonium ion, a sodium ion, a potassium ion, a hydrogen ion, or those The mixed ions of are shown.

  Next, specific examples of the azo iron complex represented by the general formula (III) will be shown.

  Specific examples of the charge control agent represented by the general formulas (I), (II), and (IV) are shown below.

  These metal complex compounds can be used alone or in combination of two or more. The amount of these charge control agents used is preferably 0.1 to 5.0 parts by mass per 100 parts by mass of the binder resin from the viewpoint of the charge amount of the magnetic toner.

  Preferred examples of the charge control agent for negative charging include Spiron Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-. 84, E-88, E-89 (Orient Chemical).

  On the other hand, examples of the charge control agent for controlling the toner to be positively charged include denatured products such as nigrosine and fatty acid metal salts, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate and the like. Quaternary ammonium salts, and onium salts such as phosphonium salts and analogs thereof and lake pigments thereof, triphenylmethane dyes and lake lake pigments (the rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten) Molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyls Borate, dioctyl tin borate, diorgano tin borate such as dicyclohexyl tin borate; and the like. These can be used alone or in combination of two or more. The amount of these charge control agents used is preferably 0.1 to 5.0 parts by mass per 100 parts by mass of the binder resin from the viewpoint of the charge amount of the magnetic toner.

  Preferred examples of the charge control agent for positive charging include TP-302, TP-415 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) N-01, N-04, N-07, P-51 (Orient Chemical Co., Ltd.) and Copy Blue PR (Clariant).

  The magnetic toner of the present invention is preferably mixed with an inorganic fine powder or a hydrophobic inorganic fine powder. For example, it is preferable to add and use silica fine powder.

  The silica fine powder used in the present invention includes both a so-called dry method produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica, and so-called wet silica produced from water glass or the like. Although it can be used, dry silica having less silanol groups on the surface and inside and no production residue is preferred.

  Further, the silica fine powder used in the present invention is preferably hydrophobized. The hydrophobicity of the silica fine powder is imparted by chemical treatment with an organosilicon compound that reacts or physically adsorbs with the silica fine powder. As a preferred method, there is a method in which a dry silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane compound or simultaneously with a silane compound, and simultaneously with an organosilicon compound such as silicone oil. .

  Examples of silane compounds used for the hydrophobization treatment include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, and bromo. Methyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilane mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyl Diethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyl Examples include tildisiloxane and 1,3-diphenyltetramethyldisiloxane.

Examples of the organosilicon compound include silicone oil. Preferred silicone oils are those having a viscosity at 25 ° C. of about 3 × 10 ⁻⁵ to 1 × 10 ⁻³ m ² / s, such as dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, α -Methylstyrene modified silicone oil, chlorophenyl silicone oil, fluorine modified silicone oil and the like are preferable.

  For example, silica fine powder treated with a silane compound and silicone oil may be directly mixed using a mixing machine such as a Henschel mixer, or the silicone oil is sprayed onto the base silica. Depending on how you do it. Alternatively, the silicone oil may be dissolved or dispersed in an appropriate solvent, and then mixed with the base silica fine powder to remove the solvent.

  If necessary, a fine powder external additive other than fine silica powder may be added to the magnetic toner in the present invention. Examples of such other external additives include a resin fine powder and an inorganic fine powder that function as, for example, a developability improver, a charging aid, a conductivity imparting agent, a fluidity imparting agent, an anti-caking agent, a lubricant, and an abrasive. Examples include the body.

  For example, lubricants such as polyfluorinated ethylene, zinc stearate, and polyvinylidene fluoride are preferable, and among them, polyvinylidene fluoride is preferable. Alternatively, abrasives such as cerium oxide, silicon carbide, strontium titanate, etc., among which strontium titanate is preferable. Alternatively, for example, fluidity imparting agents such as titanium oxide and aluminum oxide, particularly hydrophobic ones are preferable. A small amount of an anti-caking agent, or a conductivity imparting agent such as carbon black, zinc oxide, antimony oxide or tin oxide, and white and black fine particles having opposite polarity can also be used in small amounts.

  The inorganic fine powder or hydrophobic inorganic fine powder mixed with the magnetic toner may be used in an amount of 0.1 to 5 parts by mass (preferably 0.1 to 3 parts by mass) with respect to 100 parts by mass of the magnetic toner.

  The method for producing the magnetic toner of the present invention is not particularly limited except that the magnetic properties are adjusted so as to satisfy a specific range, and can be produced by a known method. Note that the specific magnetic property range of the magnetic toner of the present invention has been clarified in the present specification. The magnetic toner of the present invention can be produced by adjusting the production process of the magnetic particles and the magnetic toner so as to satisfy a specific range.

For example, in the magnetic toner of the present invention, the above-described magnetic toner material is sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then melted, kneaded and kneaded using a heat kneader such as a roll, a kneader and an extruder. Then, while the resins are mutually compatible, the magnetic particles, pigment or dye is dispersed or dissolved, cooled and solidified, pulverized and classified, and external additives such as inorganic fine powder are added as necessary. It can be obtained by mixing with a mixer. In the process of producing the magnetic toner, it is preferable that the magnetic substance is uniformly dispersed from the viewpoint of further exerting the effects of the present invention. In addition to sufficiently mixing the raw materials, it is preferable to set the melt kneading temperature at a high temperature and knead the binder resin in a melted and soft state in the melt kneading process using a thermal kneader. In particular, when a binder resin containing a hard component such as a THF-insoluble component is used, the magnetic particles can be easily dispersed uniformly by softening and kneading the binder resin at a high temperature.

  Henschel mixer (made by Mitsui Mining); Super mixer (made by Kawata); Ribocorn (made by Okawara Seisakusho); Nauter mixer, turbulizer, cyclomix (made by Hosokawa Micron); Spiral pin mixer ( Pacific Kiko Co., Ltd.); Redige mixer (manufactured by Matsubo) and the like.

  As a kneading machine, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); kneedex (manufactured by Mitsui Mining Co., Ltd.); Banbury mixer (manufactured by Kobe Steel) can be used.

  As a pulverizer, a counter jet mill, a micron jet, an inomizer (manufactured by Hosokawa Micron); an IDS type mill, a PJM jet pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.); a cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); SK Jet Oh Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Industry Co., Ltd.); Super Rotor (Nisshin Engineering), and the like.

  Classifiers include: Classy, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nissin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron) An elbow jet (manufactured by Nippon Steel Mining Co., Ltd.), a dispersion separator (manufactured by Nippon Pneumatic Industrial Co., Ltd.), YM micro cut (manufactured by Yaskawa Shoji Co., Ltd.) and the like.

  As a sieving device used for sieving coarse particles, Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (manufactured by Deoksugaku Kogyo Co., Ltd.); Examples include a turbo screener (manufactured by Turbo Industry Co., Ltd.), a micro shifter (manufactured by Kanno Sangyo Co., Ltd.), and a circular vibrating sieve.

  The magnetic toner of the present invention preferably has a weight average particle diameter of 4.5 to 10 μm. More preferably, it is 5.0-9.2 micrometers, More preferably, it is 5.2-7.7 micrometers. In the case of a magnetic toner having a weight average particle size exceeding 10 μm, there is a problem in terms of high image quality, such as fogging and fine line reproducibility, depending on the size of the toner particle itself, which is not preferable. In the case of a magnetic toner having a weight average particle size of less than 4.5 μm, even when the magnetic particles of the present invention are used, fogging and scattering may be deteriorated, which is not preferable.

  The weight average particle diameter can be measured using a Coulter Multisizer II (trade name, manufactured by Coulter, Inc.), which is a particle diameter measuring machine. For example, measurement can be performed by connecting a number distribution and volume distribution interface (manufactured by Nikka) and a personal computer to the Coulter Multisizer II.

  As an electrolytic solution used for preparing a test sample, a 1% NaCl aqueous solution in which a reagent primary sodium chloride is dissolved in water can be used. In addition, as the electrolytic solution, for example, ISOTONR-II (manufactured by Coulter Scientific Japan, trade name) can be used.

  As a test sample, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant in 100 to 150 ml of the electrolytic solution, and 2 to 20 mg of a developer sample (magnetic toner) is further added. It can be prepared by performing a dispersion treatment for about 1 to 3 minutes in a disperser. In the measurement of the weight average particle diameter by the Coulter Multisizer, a 100 μm aperture can be used as the aperture.

  The weight average particle diameter in the present invention is the weight standard obtained from the volume distribution by measuring the volume and number of individual particles of a magnetic toner particle group having a particle diameter of 2 μm or more, and calculating the volume distribution and the number distribution. It can be obtained as a weight average particle diameter (representing the representative value of each channel as the representative value of each channel).

  The weight average particle diameter of the magnetic toner can be adjusted, for example, by pulverizing / classifying the magnetic toner or mixing a classified product having an appropriate particle diameter.

  EXAMPLES Hereinafter, although a manufacture example and an Example demonstrate this invention, this invention is not limited to these manufacture examples and Examples.

[Toner regulating blade manufacturing method]
(Toner regulating blade manufacturing method 1)
While the centrifugal mold heated to 140 ° C. is rotated at a rotation speed of 800 rpm, a thermosetting resin liquid (epoxy resin heat-resistant temperature 150 ° C.) is poured into the centrifugal mold and sufficiently cured by heating. Thus, a holding layer (eccentricity compensation layer) having a thickness of 1.0 mm was provided. Next, in the process of forming a release layer of silicone rubber to a thickness of 2.0 mm on the inner peripheral surface of the holding layer, the inner peripheral surface is in toluene before the release layer is completely cured. The surface-roughening agent (graphite fluoride weight average particle size 8.0 μm, standard deviation 1.53) dispersed in was sprayed. The urethane forming liquid is poured into the release layer formed as described above, Rz = 10.2 μm, Sm = 35.1, and the glass plate is brought into contact with the surface pressure of 14.4 Pa. A toner regulating blade 1 having an area ratio of 0.40 was obtained. This toner regulating blade had a rubber hardness of 65 ° and a thickness of 1.17 mm. The toner regulating blade 1 thus obtained was press-cut to a desired size, and the toner regulating blade 1 bonded to a metal toner regulating blade support member with an adhesive was used for evaluation.

(Toner regulating blade manufacturing method 2)
A toner regulating blade 2 was obtained in the same manner as in the toner regulating blade manufacturing method 1 except that graphite fluoride having an average particle diameter of 15.2 μm and a standard deviation of 5.23 was used.

(Toner regulating blade manufacturing method 3)
The collecting surface of the centrifugal shaping mold was blasted by spraying 60 glass bead particles with an air thickness of 4.5 kg / cm ² . When the urethane forming liquid is poured into the centrifugal mold, Rz is 24.5 μm, Sm is 120.3, and the glass plate is brought into contact with the surface pressure of 14.4 Pa, the area ratio of the entire contact portion is A toner regulating blade 3 of 0.27 was obtained. This toner regulating blade had a rubber hardness of 65 ° and a thickness of 1.17 mm. The toner regulating blade 3 obtained as described above was press-cut to a desired size, and the toner regulating blade 3 bonded to a metal toner regulating blade support member with an adhesive was used for evaluation.

(Toner regulating blade manufacturing method 4)
Except for spraying fluorinated graphite having an average particle size of 15.2 μm and a standard deviation of 5.23 and then spraying fluorinated graphite having an average particle size of 4.1 μm and a standard deviation of 1.35, the same as in the toner regulating blade manufacturing method 1 Thus, a toner regulating blade 4 was obtained.

(Toner regulating blade manufacturing method 5)
A toner regulating blade 5 was obtained in the same manner as in the toner regulating blade manufacturing method 1 except that fluorinated graphite having an average particle size of 4.1 μm and a standard deviation of 1.35 was used.

(Toner regulating blade manufacturing method 6)
A toner regulating blade 6 was obtained in the same manner as in the toner regulating blade manufacturing method 5 except that the amount of the roughening treatment agent applied was reduced.

(Toner regulating blade manufacturing method 7)
A toner regulating blade 7 was obtained in the same manner as in the toner regulating blade manufacturing method 3 except that the amount of glass bead particles sprayed was less than that of the toner regulating blade manufacturing method 3.

(Toner regulating blade manufacturing method 8)
The toner control blade is the same as the toner control blade manufacturing method 7 except that the glass bead particles of # 180 are used, the spraying amount is smaller than that of the toner control blade manufacturing method 7, and the obtained toner control blade is cured. 8 was obtained.

  Table 1 shows the physical properties of the toner regulating blade.

  Table 2 shows the magnetic materials used, Table 3 shows the binder resin, and Table 4 shows the physical properties of the wax.

(Magnetic toner production example 1)
-Binder resin 1: 100 parts by mass-Wax 1: 4 parts by mass-Magnetic substance 1: 95 parts by mass-T-77 (made by Hodogaya Chemical Co., Ltd.): 2 parts by mass After premixing at Mitsui Mining Co., Ltd.), the set temperature is adjusted so that the direct temperature near the outlet of the kneaded product is 150 to 160 ° C. by a biaxial kneading extruder set at 200 rpm. Kneaded. The obtained kneaded product is cooled and coarsely pulverized with a cutter mill, and then the obtained coarsely pulverized product is finely pulverized using a turbo mill (manufactured by Turbo Kogyo Co., Ltd.) as a pulverizer, and divided into multiple parts utilizing the Coanda effect. Classification was performed using a classifier to obtain negatively chargeable magnetic toner particles 1 having a weight average particle diameter (D4) of 6.1 μm.

  To 100 parts by mass of the magnetic toner particles 1, 1.0 part by mass of hydrophobic silica fine particles 1 treated with hexamethyldisilazane and then with dimethylsilicone oil was added, and a Henschel mixer (Mitsui Mine) as a mixer was added. The magnetic toner 1 was obtained by external addition mixing. Table 5 shows the physical properties of this magnetic toner 1.

(Production Examples 2 to 7 of magnetic toner)
In magnetic toner production example 1, as shown in Table 5, magnetic toners 2 to 7 were prepared in the same manner as in production example 1 except that the binder resin, wax type, and magnetic material type and number of copies were changed. Obtained. Table 5 shows the physical properties of the magnetic toners 2 to 7.

[Example 1]
(Evaluation 1)
A commercially available LBP printer (Laser Jet 1320, manufactured by HP) was modified to obtain A4 size 45 sheets / minute (process speed 259 mm / sec), and the capacity of the toner filling portion was doubled. As a developing sleeve as a toner regulating blade filled with magnetic toner 1, a developing sleeve having a developing pole magnetic pole of 76 mT (760 gauss) inside, a surface roughness Ra of 1.0 μm and a diameter of Φ13 is provided. A built-in modified process cartridge was installed.

Using this as an image test machine, the machine was left in a low-temperature, low-humidity environment at 15 ° C. and 10% RH overnight, and the horizontal line pattern with a printing rate of 4% was taken as one sheet / job. A print endurance test of 5000 sheets was performed using A4 plain paper (75 g / m ² ) in a mode in which the next job was started after the stop.

  During this print durability test or after a durability test of 5000 sheets, the following image characteristics and photoconductor scratches were evaluated.

  The image density was measured by measuring the reflection density of a solid black image of 5 mm square using an SPI filter with a Macbeth densitometer (Macbeth Co.) which is a reflection densitometer. As a result, the reflection density before endurance was 1.53, the reflection density after endurance was 1.52, the density stability was good, and a solid black image was printed and visually observed. It was a uniform image. The results are shown in Table 8.

  The evaluation standard of image density is shown below.

As a result of calculating a decrease rate of reflection density after endurance of 5000 sheets with respect to after endurance of 1000 sheets, and a result of visual evaluation after outputting a solid black image after 20,000 sheets,
A: The reduction rate was less than 2%, and a solid black image without density unevenness was obtained even after 5000 sheets.
B: The reduction rate was 2% or more and less than 3%, and a solid black image without density unevenness was obtained even after 5000 sheets.
C: The decrease rate is 3% or more and less than 5%, and slight density unevenness is seen after 5000 sheets.
D: The decrease rate becomes 5% or more, or density unevenness is conspicuous after 5000 sheets.

Blotch In durability under a low temperature and low humidity environment, the blotch was evaluated from the toner coat state on the developing sleeve and the printed image in the first 100 images.
A No blotch is seen on the developing sleeve.
B Although slightly seen on the developing sleeve, the effect does not appear on the image.
C It is seen on the developing sleeve and the effect appears faintly on the image.
D Blotches are seen on the developing sleeve, and the effect appears remarkably on the image.

  For the fog, at the end of 2500 sheets during the endurance test, set the amplitude of the AC component of the development bias to 1.8 kV (default is 1.6 kV), print two solid white sheets, and the second sheet below It measured by the method of.

  Using a reflection densitometer (reflectometer model TC-6DS manufactured by Tokyo Denshoku Co., Ltd.), the transfer material before and after the image formation is measured, and the reflection density worst value after the image formation is Ds, and the reflection average density of the transfer material before the image formation. Was Dr, Ds-Dr was determined, and this was evaluated as the fogging amount. A lower number indicates less fogging. As a result, the fogging amount was 0.9, which was good. The results are shown in Table 8.

The evaluation criteria for fogging are shown below.
A: Less than 1.0.
B: 1.0 or more and less than 2.0.
C: 2.0 or more and less than 3.5.
D: 3.5 or more.

An image of an isolated dot pattern having a small diameter (50 μm) as shown in FIG. 6 which is easy to close due to the latent image electric field and difficult to reproduce was printed out, and the dot reproducibility was evaluated.
A: 2 or less defects / 100 B: 3-5 defects / 100 defects C: 6-10 defects / 100 defects D: 11 defects / 100 defects / 100

  After the evaluation of dot reproducibility was completed, the occurrence of scratches on the surface of the photoreceptor was visually confirmed to confirm the influence on the image. As a result, the occurrence of scratches on the photoreceptor was not confirmed. The results are shown in Table 8.

The evaluation criteria are shown below.
A: Very good.
B: Good. Slight scratches are seen on the photoreceptor, but there is little effect on the image.
C: Scratches are observed on the photoreceptor, but there is little effect on the image and there is no practical problem.
D: An image defect caused by a scratch on the photoconductor occurs.

[Examples 2 to 7]
Evaluation was performed in the same manner as in Example 1 using magnetic toners 2 to 4. Table 5 shows the magnetic permeability and H95% of the toner. Table 1 shows the physical properties of the toner regulating blade used, and Table 6 shows the physical properties of the developing sleeve. Table 7 shows the toner regulating blade and the developing sleeve used. The evaluation results are shown in Table 8.

[Comparative Examples 1-4]
Evaluation was performed in the same manner as in Example 1 using magnetic toners 2, 5, 6, and 7. Table 5 shows the magnetic permeability and H95% of the toner. Table 1 shows the physical properties of the toner regulating blade used, and Table 6 shows the physical properties of the developing sleeve. Table 7 shows the toner regulating blade and the developing sleeve used. The evaluation results are shown in Table 8. In Comparative Example 4, when the inside of the machine after the endurance was viewed, the toner was scattered and was quite dirty.

The area of the contact portion and the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate are brought into contact at a surface pressure of 14.4 Pa are binarized. The black part is the contact part. In this method, the toner regulating blade is roughened using a die that is bead-blasted with roughened particles. In this method, the toner regulating blade is roughened by using a mold layer on which a release layer containing a roughening treatment agent is formed. An example of a hysteresis loop is shown. An example (enlarged view) of a hysteresis loop is shown. The dot pattern used for dot reproducibility evaluation is shown.

Claims (6)

A toner carrying member comprising a cylindrical developing sleeve rotatably supported in a developing container from a developing container containing toner, and a magnet roller having a plurality of magnetic poles in the developing sleeve and arranged non-rotatingly The magnetic toner is used in an image forming method in which the magnetic toner is conveyed, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. Because
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
A magnetic toner characterized by satisfying   2. The average interval Sm of unevenness measured with a laser microscope on the surface of the toner regulating blade on the side in contact with the toner carrying member is 5.0 μm or more and 200.0 μm or less. Magnetic toner. A toner carrying member comprising a cylindrical developing sleeve rotatably supported in a developing container from a developing container containing toner, and a magnet roller having a plurality of magnetic poles in the developing sleeve and arranged non-rotatingly An image forming method in which the magnetic toner is conveyed, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier,
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
An image forming method characterized by that.   4. The average interval Sm of unevenness measured with a laser microscope on the surface of the toner regulating blade on the side in contact with the toner carrying member is 5.0 μm or more and 200.0 μm or less. Image forming method. A toner carrying member comprising a cylindrical developing sleeve rotatably supported in a developing container from a developing container containing toner, and a magnet roller having a plurality of magnetic poles in the developing sleeve and arranged non-rotatingly A process cartridge used in an image forming method in which the magnetic toner is conveyed by the toner, the toner layer thickness of the toner carrier is regulated by a toner regulating blade, and the electrostatic latent image carrier is developed with the magnetic toner on the toner carrier. Because
The ten-point average roughness Rz measured with a laser microscope on the surface of the toner regulating blade in contact with the toner carrier is 5.0 μm or more and 25.0 μm or less,
The ratio of the area of the contact portion to the area of the non-contact portion when the portion of the toner regulating blade in contact with the toner carrier and the glass plate is brought into contact at a surface pressure of 14.4 Pa is 8/92 to 70/30,
The magnetic force (peak magnetic flux density) acting in the direction of the developing sleeve center of the magnetic field of the magnet roller is 50 mT or more and 100 mT or less at the portion where the toner regulating blade and the toner carrier are in contact with each other.
And the magnetic toner has a magnetic permeability in the range of 0.6 μH / m to 1.2 μH / m,
The saturation magnetization of the magnetic toner at 397.9 kA / m is σs (Am ² / kg), and the strength of the magnetic field when showing a magnetization value corresponding to 95% of σs is H95% (kA / m). H95% is 135 <H95% <200
Process cartridge characterized by being.   6. The average interval Sm of unevenness measured with a laser microscope on the surface of the toner regulating blade on the side in contact with the toner carrying member is 5.0 μm or more and 200.0 μm or less. Process cartridge.

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