JP6666033B2 - toner - Google Patents

Description

  The present invention relates to a toner used in electrophotography, that is, an image forming method for visualizing an electrostatic image.

  Generally, in electrophotography, after a photosensitive drum (image carrier) using a photoconductive substance is uniformly charged to a desired polarity and potential, an image pattern exposure is performed on the photosensitive drum. An electric latent image is formed. Thereafter, the toner is developed and visualized, and this is transferred and fixed on a transfer medium such as paper. Further, the toner remaining on the photosensitive drum after the transfer step is removed. The most widely used removal method is blade cleaning. That is, there is a method in which an elastic blade-like member such as rubber is pressed against the surface of the photosensitive drum to scrape off the toner.

  As a toner used for such electrophotography, a spherical toner has characteristics such as excellent transferability and fine line reproducibility. On the other hand, in a system in which the toner is cleaned from the photosensitive drum by the cleaning blade, the cleaning becomes more difficult as the circularity of the toner increases. It is considered that one of the causes is that the high circularity causes the toner to roll and easily slip through the contact nip between the cleaning blade and the photoconductor.

  In order to prevent defective cleaning of the spherical toner, the following method has been proposed in Japanese Patent Application Laid-Open No. H11-157,837. In other words, this method is to stabilize the cleaning by forming a layer due to the accumulation of the external additive at the blade edge and forming a layer that blocks the toner particles.

  Further, Japanese Patent Application Laid-Open No. H11-163873 proposes a means for reducing the transfer residual toner and improving the cleaning performance by reducing the adhesive force by embedding an external additive in the spherical toner.

  Patent Literature 3 proposes a means for improving toner cleaning performance by forming a toner pool in a cleaning unit.

JP-A-2002-318467 JP 2012-68325 A JP 2008-276005 A

  In the case of the method disclosed in Patent Document 1, an external additive for forming a toner blocking layer may pass through the blade and contaminate the charging member. If a mechanism for cleaning the charging member is provided to prevent such a problem, the mechanism becomes complicated or causes an increase in cost. In particular, in a system that requires a long service life, the formation of a blocking layer becomes insufficient due to embedding of an external additive in the toner during use for a long period of time and roughening of the photosensitive drum surface (uneven wear). Sometimes. As a result, cleaning of the toner becomes difficult.

  According to the technique disclosed in Patent Document 2, it is not easy to obtain sufficient cleaning performance with toner having a high shape factor SF1 and a high circularity.

  In the method of Patent Document 3, it is necessary to mount a member for forming a toner reservoir for cleaning performance.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a spherical toner that can provide good cleaning properties, has excellent fine line reproducibility, and can reduce contamination of a charging member even in an electrophotographic system that requires a long life. is there.

According to one embodiment of the present invention, a toner having toner particles and fine particles on the surface of the toner particles,
(I) the average circularity of the toner particles is 0.970 or more,
(Ii) the fine particles contain fine particles A having a number average particle diameter (D1) of primary particles of 200 nm or more and 500 nm or less;
(Iii) a release rate of the fine particles A from the toner particles is 15% by mass or more and 40% by mass or less;
(Iv) of the toner, wall friction angle θ is calculated from the following formula, not more than 10 ° or more on the 15 °,
θ = τ / σ
(Using the toner, .Shiguma for forming a toner powder layer A giving vertical load of 9.0kPa is in the toner powder layer A, the vertical load at which a penetration of the disk-shaped disk (kPa) Table be. tau, it represents a disc-shaped disc infested to the toner powder layer a, the shear stress obtained when to (π / 10) in rad / min (π / 36) rad rotation, measurements σ = 3 kPa.)
(V) using the toner, the toner powder layer B is formed by applying a load load 3 kPa, said the toner powder layer B, a propeller blade which rotates at a peripheral speed 100 mm / s of the outermost edge vertically is advanced, the start measurement from the position of 100mm from the bottom surface of the toner powder layer B, to the position of 10mm from the bottom surface obtained when caused to enter the propeller blades, the rotation torque and a vertical of the propeller blade total Energy Et is the sum of the load, Ru der following 300mJ than the 600 mJ,
A toner is provided.

  According to the present invention, it is possible to provide a spherical toner that provides good cleaning properties, has good fine line reproducibility, and can reduce contamination of a charging member even in an electrophotographic system requiring a long life. it can.

It is a figure which shows the propeller type blade in a powder fluidity analyzer, a is the figure which looked at the long side of the blade in front, and b is the schematic diagram which looked at the outermost edge part of the blade in front. It is a schematic diagram which shows the disk-shaped disk for measuring a wall friction angle, a is a bird's-eye view and b is a bottom view. It is the schematic which shows an example of an external attachment apparatus. It is a figure for explaining four fields used in measurement of the abundance rate of particles, etc.

The present invention relates to a toner particle and a toner having fine particles on the surface of the toner particle. This toner satisfies the following conditions i to v .

( I) The average circularity of the toner particles is 0.970 or more.
(Ii) The fine particles contain fine particles A having a number average particle diameter (D1) of primary particles of 200 nm or more and 500 nm or less.
(Iii) The release rate of the fine particles A from the toner particles is 15% by mass or more and 40% by mass or less.

(Iv) The following formula θ = τ / σ of the toner
Is 10 ° or more and 15 ° or less.
Here, σ represents a vertical load (kPa) when a disc-shaped disk is inserted into the toner powder layer A formed by applying a vertical load of 9.0 kPa using the toner.
τ represents a shear stress obtained when a disk is penetrated into the toner powder layer A and rotated at (π / 10) rad / min by (π / 36) rad, and this measurement is σ = 3 kPa Do with.

(V) The total energy Et is 300 mJ or more and 600 mJ or less. Et is measured by applying a propeller type blade rotating at a peripheral speed of 100 mm / s at the outermost edge vertically to a toner powder layer B formed by applying a load of 3 kPa using the toner. At that time, the measurement is started from a position 100 mm from the bottom of the toner powder layer B, and is perpendicular to the rotational torque of the propeller blade obtained when the propeller blade is advanced to a position 10 mm from the bottom. The sum of the loads is Et.

  In the cleaning section, the toner is prevented from slipping through by pressing a cleaning blade against the photosensitive drum. Conventionally, in order to satisfy the cleaning performance of the spherical toner, a configuration is adopted in which the spherical toner does not easily enter by increasing the contact pressure of the cleaning blade against the photosensitive drum. However, when the contact pressure of the cleaning blade is increased, the photosensitive drum is easily worn, and a new problem occurs. In particular, there was a problem with long-life systems.

  Therefore, the present inventors paid attention to the state of the toner at the cleaning blade. In the cleaning section, the toner contacts the photosensitive drum under a load by the force applied to the blade edge, and the toners are in a compact state. Spherical toner is characterized in that good transferability can be obtained due to its small surface irregularities, but on the other hand, when a load is applied, the contact area with the photosensitive drum increases, so that the frictional force increases. As a result, it becomes difficult to clean the photosensitive drum. Therefore, it has been found that it is important to reduce the frictional force between the compacted toner and the flat plate in order to improve the cleaning property of the toner.

  In order to reduce the frictional force between the toner and the flat plate in the compacted state, it can be reduced by coating the surface of the toner particles with an external additive. However, the present inventors have found that in order to improve the cleaning performance, not only the frictional force between the toner and the flat plate but also the ease with which the toners are loosened is important. If the toner is not easily loosened in the cleaning unit where the toner is in a compact state, the toner exerts a force to push up the cleaning blade, and as a result, the cleaning performance of the toner is deteriorated.

The present inventors have conducted intensive studies in order to develop the above characteristics with a spherical toner. As a result, it has been found that the toner needs to satisfy the above-mentioned characteristics of vi and v .

  The reason why the present inventors need to fall within the above range of the physical properties of the toner in order to obtain good cleaning properties will be described below. It has been found that irregularly shaped toner particles exhibit good cleaning properties. As a result of various studies on the physical properties of the toner, it was found that the index (Et) of the ease of loosening between the toner and the toner was appropriate. On the other hand, it was found that the spherical toner has a high index (Et) of the ease of loosening between the toners. As a result of examining the difference, it has been found that the spherical toner has a smooth surface, which results in surface contact between the toner and the toner. Therefore, in order to change the surface contact between the toner and the toner from the point contact, a study was conducted focusing on an external additive having a large particle diameter.

  Then, when a factor that the irregular-shaped toner is easily loosened was examined, it was found that irregularities existed on the toner surface. Therefore, it has been considered that even with spherical toner particles, it is possible to control the ease of loosening between toner and toner by externally adding a large particle size external additive. Investigations were made with a focus on the particle diameter of the external additive. When the particle diameter is about 100 nm, the toner is easily loosened between the toners, but the slipperiness between the toner and the flat plate is insufficient and the life is long. It was insufficient to satisfy the cleaning property of the system. Then, as a result of further study by increasing the particle size of the external additive, it was found that the toner is hardly loosened. As a result of studying the reason, it was found that the fixation of the external additive was insufficient. Therefore, it was found that it was necessary to fix the external additive, and that the fine particles A had a release rate from the toner of 10% by mass or more and 50% by mass or less.

  Here, the term “release” refers to separation of fine particles from the toner surface. When the fine particles are released from the toner surface, a phenomenon that the released fine particles are aggregated with each other or transferred to a member in an image forming apparatus such as a printer easily occurs, and various member contaminations are easily caused in an electrophotographic process. There is a problem that. Here, the transition means that the fine particles move to a member in an image forming apparatus such as a printer.

  Further, as the fine particles used as the external additive, it is necessary to contain fine particles A having a number average particle diameter (D1) of primary particles of 200 nm or more and 500 nm or less.

  With such a toner, the ease of loosening between the toner and the toner and the smoothness between the toner and the flat plate can both be satisfied, and as a result, satisfactory cleaning properties and transfer properties can be satisfied even in a long life system. . The number average particle diameter (D1) of the primary particles of the fine particles is preferably from 250 nm to 400 nm, and the release rate is preferably from 15% by mass to 40% by mass.

<Measurement method of wall friction angle>
The wall friction angle measured when a disc is pressed against the surface of the toner powder layer in a compacted state is measured by a powder rheometer FT4 (trade name, manufactured by Malvern Co., Ltd .; hereinafter, abbreviated as "FT4"). Measurement). At that time, a rotary propeller type blade and a disk-shaped disk blade (disk-shaped disk) are used.

  A 48.0 mm diameter blade dedicated to FT4 measurement is used for a rotary propeller type blade (hereinafter sometimes abbreviated as “propeller”). As shown in FIG. 1, this propeller type blade is formed of a 48 mm × 10 mm blade plate. A rotation axis exists at the center of the blade plate in the normal direction (a shaft body is provided). The blade plate is smoothly twisted counterclockwise such that both outermost edges (a portion 24 mm from the rotation axis) are 70 ° and a portion 12 mm from the rotation axis is 35 °. The term “counterclockwise” as used herein means counterclockwise when the blade plate is viewed from the outer edge of the blade plate toward the rotation axis. The material of the blade plate is stainless steel.

  For the measurement of the wall friction angle, a disk-shaped disk blade (see FIG. 2: 48.0 mm in diameter, 1.5 mm in thickness, made of stainless steel, and may be abbreviated as “disk” below). Used. Note that a laminated sheet having a NANOS layer (a layer formed by thinning a fluorine-based polymer on the order of nanometers) as the outermost surface is attached to the surface of the disk (the surface in contact with the toner). This laminated sheet is a sheet laminated in the order of (1) an adhesive layer, (2) a PET film, (3) an antireflection layer, and (4) a NANOS layer. The ten-point average roughness Rz (according to JIS B0601: 1982) of the surface of the laminated sheet is about 0.060 μm (measured by a surface roughness measuring device Surfcoder SE3500 (trade name) manufactured by Kosaka Laboratory Co., Ltd.). This laminated sheet can be obtained from Katsurayama Technology Co., Ltd.

  As a method for attaching the sheet, the sheet is attached to the disk surface on the side pressed against the powder layer. At this time, a sheet is stuck except for a screw hole (shown in FIG. 2B, diameter of 4.0 mm) for fixing the disk to the rotating shaft. The purpose of attaching the sheet is to make it easy to measure the friction between the toner powder layer and the flat plate by using a slippery material for the disc.

  When measuring the wall friction angle, 60 g of toner left for 3 days or more in a 23 ° C., 60% RH (relative humidity) environment was placed in a cylindrical split container having a diameter of 50 mm and a volume of 190 ml dedicated to FT4 measurement. Layer (toner powder layer). This split container (hereinafter sometimes abbreviated as a container) has a height from the bottom surface to the split portion of 43 mm, and is made of glass.

(1) Conditioning operation The propeller is advanced from the surface of the powder layer to a position 10 mm from the bottom surface of the powder layer. At this time, in the rotation direction clockwise (the direction in which the powder layer is loosened by the rotation of the propeller) with respect to the powder layer surface, at a rotational speed at which the peripheral speed of the outermost edge of the propeller is 60 (mm / sec), Rotate propeller. Also, the vertical approach speed to the powder layer is 5 (the angle between the locus drawn by the outermost edge of the moving propeller and the surface of the powder layer (hereinafter sometimes abbreviated as “angle”) is 5 ( deg).

  Thereafter, the propeller is further advanced to a position 1 mm from the bottom surface of the powder layer. At this time, the propeller is rotated clockwise with respect to the powder layer surface at a rotational speed at which the peripheral speed of the outermost edge of the propeller is 40 (mm / sec). In addition, the vertical approach speed to the powder layer is a speed at which the “angle” becomes 2 (deg).

  Thereafter, the propeller is extracted by moving the propeller to a position 80 mm from the bottom surface of the powder layer. At this time, the propeller is rotated in a counterclockwise rotation direction with respect to the powder layer surface at a rotation speed at which the peripheral speed of the outermost edge of the propeller is 60 (mm / sec). In addition, the extraction speed from the powder layer is set to a speed at which the “angle formed” becomes 5 (deg).

  When the removal is completed, the toner attached to the propeller is wiped off by alternately rotating the propeller clockwise and counterclockwise alternately.

(2) Consolidation Operation of Toner Here, a compression test piston (diameter: 48.0 mm, height: 20 mm, lower mesh tension) is used instead of the propeller blade. The compression test piston is moved vertically downward at a rate of 0.5 mm / sec from a height of 80 mm from the bottom surface of the powder layer to enter the powder layer. When a load of 0.55 kPa is applied to the surface of the powder layer, the blade entry speed is changed to 0.04 mm / sec. When 9.0 kPa was applied to the surface of the powder layer, the piston was stopped. After compacting was performed for 60 seconds, the piston was moved vertically upward.

(3) Split Operation The toner powder layer is cut off at the split part of the above-mentioned container dedicated to FT4 measurement, and the toner on the toner powder layer is removed, thereby forming a toner powder layer of a fixed volume (85 ml).

(4) Measurement operation Subsequently, the wall friction angle θ is obtained by the following operation.

  (4.1) The compression test piston was replaced with the disk which is a blade for measuring wall friction, and the disk was lowered at 0.08 (mm / sec). When a load of 9.0 kPa was applied to the powder layer, Stop the disk. This compacts the powder layer again. In this operation, the disk is not rotated.

  (4.2) Thereafter, the disk is rotated (π / 3) rad at a speed of (π / 10) rad / min clockwise with respect to the surface of the powder layer to apply preliminary shearing to the surface of the powder layer.

  (4.3) Next, by stopping the rotation of the disk, the shear load is removed, and only the vertical load σ3.0 kPa is applied, so that a standby state of 25 (sec) is set.

  (4.4) After the standby, the rotation torque is calculated from the rotation torque when the disk is rotated (π / 10) rad / min by (π / 36) rad in the clockwise rotation direction with respect to the surface of the toner powder layer. Is measured.

  (4.5) Using the value of the vertical load σ (3 kPa) and the obtained shear stress τ, the wall friction angle θ is obtained from the equation “θ = τ / σ”.

  The wall friction angle indicates the frictional resistance between the surface of the toner powder layer and the flat plate. The larger the wall friction angle is, the higher the friction resistance is, and the smaller the wall friction angle is, the smaller the friction resistance is. If the wall friction angle is smaller than 10 °, the frictional resistance with the drum is too small, so that the toner scatters easily at the time of transfer. On the other hand, if the angle is larger than 15 °, the frictional resistance becomes high, and it becomes difficult to scrape off the toner by the blade during cleaning, and the cleaning performance deteriorates. It is preferable that the wall friction angle is 11 ° or more and 14 ° or less. The reason for setting the vertical load at the time of measurement to 3.0 kPa is that the amount of toner attached to the sheet attached to the disk blade surface is small.

<Method of Measuring Total Energy Et of Toner Powder Layer>
Et (mJ) is measured using the powder rheometer FT4 (trade name) described above.

  In all operations, the same rotary propeller blade used for measuring the wall friction angle is used. As the measurement container, a cylindrical split container (model number: C203, material: glass, diameter: 50 mm, volume: 160 ml, height from the bottom to the split portion: 82 mm, hereinafter sometimes abbreviated as the container) is used for the FT4. .

  In the measurement of the total energy Et, 100 g of the toner left for 3 days or more in an environment of a temperature of 23 ° C. and 60% RH is put into the above-mentioned measurement container to form a toner powder layer.

(1) Conditioning operation (1a) The propeller is rotated clockwise (the direction in which the powder layer is loosened by the rotation of the propeller) with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the propeller becomes 60 mm / sec. Rotate. The propeller is moved from the powder layer surface to the toner powder layer at an entry speed at which the “angle” (the angle between the locus drawn by the outermost edge of the moving propeller and the surface of the powder layer) is 5 °. Introduce vertically to a position 10 mm from the bottom.

  Then, the toner powder was rotated clockwise with respect to the powder layer surface such that the peripheral angle of the outermost edge of the propeller was changed to 60 mm / sec while changing the approach speed at which the “angle” was 2 °. The propeller is advanced to a position 1 mm from the bottom of the layer.

  Further, while rotating clockwise with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the propeller is 60 mm / sec at a speed at which the “angle” is 5 °, the bottom surface of the toner powder layer is Extraction is performed by moving the propeller to a position of 100 mm. After the extraction is completed, the toner adhering to the blade is wiped off by alternately rotating the blade slightly clockwise and counterclockwise.

  (1b) The above operation 1a is repeated five times to remove air taken into the toner powder layer.

(2) Compression operation A pressure of 3 kPa is applied to the toner powder layer subjected to the conditioning operation in (1) to compress the layer. Specifically, a compression test piston (diameter 48 mm, height 20 mm, lower mesh tension) is used in place of the propeller blade. The piston is lowered at 0.1 mm / s to compress the toner. When the load on the piston reaches 3 kPa, the lowering is stopped, and the piston is held for 60 seconds to form a compressed powder layer, and then the piston is raised.

(3) Split operation The conditioned and compressed powder layer is cut off at the split portion of the FT4 dedicated container, and the toner on the powder layer is removed. That is, a powder layer having a height of 82 mm is obtained. By this operation, the volume of the toner powder layer can be made the same every measurement.

(4) Et measurement operation (4a) The propeller is pushed counterclockwise with respect to the powder layer surface (the powder layer is pushed by the rotation of the blade) so that the peripheral speed of the outermost edge of the propeller becomes 100 mm / sec. Direction). The propeller is vertically advanced from the surface of the powder layer to a position 10 mm from the bottom surface of the toner powder layer at an entrance speed at which the “angle” becomes 5 °.

  Thereafter, the propeller is rotated clockwise with respect to the surface of the powder layer so that the peripheral speed of the outermost edge of the propeller is 60 mm / sec, and the “angle” which makes the vertical approach speed to the powder layer is increased. At a speed of 2 °, the powder layer is advanced to a position 1 mm from the bottom of the powder layer.

  Further, the propeller is lifted at a speed at which the “forming angle” becomes 5 ° to a position 100 mm from the bottom surface of the powder layer so that the peripheral speed of the outermost edge becomes 60 mm / sec, and extraction is performed.

  When the removal is completed, the toner attached to the propeller is wiped off by alternately rotating the propeller clockwise and counterclockwise alternately.

(4b) Measurement of Et The rotational torque and the vertical load applied to the propeller, which are measured when the propeller enters from a position of 100 mm to a position of 10 mm from the bottom surface of the toner powder layer, are converted into energy, and the total energy is calculated from the sum thereof. (Et) was obtained.

  The total energy Et indicates the easiness of loosening of the toner particles in the consolidated toner powder layer, and is a physical property value indicating that the lower the Et, the easier it is to loosen, and the higher the Et, the more difficult it is to loosen. If Et is larger than 600 mJ, the toner exerts a force to push up the cleaning blade at the cleaning nip portion, and the cleaning performance is deteriorated. If Et is less than 300 mJ, the toner tends to move in the nip portion of the cleaning blade, and the toner slips through the cleaning blade, and the cleaning property is deteriorated. More preferably, Et is 350 mJ or more and 550 mJ or less.

<Presence of fine particles>
Furthermore, the present inventor has studied to make it possible to provide a toner that can function as spacer particles and provide a highly durable toner, and as a result, has found that the presence state of the fine particles on the surface of the toner particles is significant. Was.

  That is, in the reflected electron image of the toner surface photographed at a magnification of 20,000 by a scanning electron microscope, the average value of the abundance of fine particles having a particle diameter of 200 nm or more and 500 nm or less in each of the four regions is calculated as The fine particle abundance Er on the surface of one toner is defined as Er. At this time, it is preferable that the average value of Er is not less than 5 area% and not more than 40 area%. This is because it has been found that, by limiting the particle size to a particle size of 200 nm or more and 500 nm or less, slipperiness with the surface of the photoreceptor is exhibited, and good fine line reproducibility and contamination of the charging member can be further reduced, which is preferable.

Definition of the above four areas:
In the reflected electron image of the toner, the chord giving the maximum length is a line segment A, and two straight lines parallel to the line segment A and separated from the line segment A by 1.5 μm are a straight line B and a straight line C. A straight line passing through the midpoint of the line segment A and orthogonal to the line segment A is defined as a straight line D, and two straight lines parallel to the straight line D and separated from the straight line D by 1.5 μm are defined as a straight line E and a straight line F. Four regions each formed by a line segment A and straight lines B, C, D, E, and F, each of which is a square having a side length of 1.5 μm.

<Method of measuring the abundance of fine particles>
A reflected electron image of one toner is observed at a magnification of 20,000 times using a scanning electron microscope “S-4800” (trade name; Hitachi, Ltd.). In the reflected electron image of the toner, as shown in FIG. 4, the maximum length of the chord of the toner is defined as a line segment A, and two straight lines parallel to the line segment A and separated from the line segment A by 1.5 μm are defined as straight lines. B and a straight line C. A straight line passing through the midpoint of the line segment A and orthogonal to the line segment A is defined as a straight line D, and two straight lines parallel to the straight line D and separated from the straight line D by 1.5 μm are defined as a straight line E and a straight line F. Four regions each of which is a square formed by the line segment A and the straight lines B, C, D, E, and F and having a side length of 1.5 μm are defined.

The area occupied by the fine particles having a particle size of 200 nm or more and 500 nm or less in each of the four regions was calculated using image processing software “Image-Pro Plus 5.1J” (trade name, manufactured by Media Cybernetics). For each of the four regions, the ratio of the calculated area to the area of the region (calculated area ÷ 2.25 μm ² ) was defined as the abundance ratio in each region. Then, as the average value of the abundance ratios in the four regions, the abundance ratio of fine particles (absence ratio of the fine particles having a particle diameter of 200 to 500 nm) Er on the surface of one toner is obtained.

  This operation was performed for 50 toners, and the average value of Er was defined as the average abundance of fine particles having a particle size of 200 to 500 nm for the toner. The “presence of fine particles” shown in Table 2 means this average abundance (average value of Er).

  When the average abundance (average value of Er) is 5% by area or more, it is easy to obtain good sliding properties between the toner and the flat plate, and it is easy to obtain good cleaning properties. Further, when the average abundance is 40 area% or less, the gap between the toners is easily loosened, and it is easy to obtain good cleaning properties.

<Coefficient of variation of the number of fine particles>
It is preferable that the coefficient of variation (the calculation method will be described in detail below) calculated from the number of fine particles having a particle size of 200 nm or more and 500 nm or less in the four regions is 0.5 or less.
When the coefficient of variation is high, there is a tendency that the state of adhesion of the fine particles is high and the slipperiness between the toner and the flat plate is reduced.

<Method of measuring the coefficient of variation of the number of fine particles>
Using a scanning electron microscope “S-4800” (trade name; Hitachi, Ltd.), a reflected electron image of the toner is observed at a magnification of 20,000 times. In the reflected electron image of the toner, four regions each of which is formed by the above-described line segment A and the straight lines B, C, D, E, and F and each of which is a square having a side length of 1.5 μm are defined.

The number of fine particles having a particle diameter of 200 to 500 nm in each region is calculated by counting the number of fine particles having a particle diameter of 200 nm or more and 500 nm or less. By adding the number of particles present in each region, the number of particles En having a particle diameter of 200 to 500 nm on one toner surface is calculated. That is, the total value of the four existing numbers for each area is defined as the number En of fine particles existing on one toner surface. This operation was performed for 50 toners, the average value of En and the standard deviation were calculated, and the coefficient of variation was calculated from the following equation.
Coefficient of variation = (standard deviation of En / average value of En).

<Materials of fine particles>
Fine particles having a number average particle diameter (D1) of primary particles of 200 nm or more and 500 nm or less exist on the surface of the toner particles. The fine particles are not particularly limited as long as the number average particle size (D1) of the primary particles is within this range. Examples of the fine particles include inorganic fine particles such as silica, alumina, and titanium oxide, resin fine particles, and organic-inorganic composite particles.

  Any silica produced by a conventionally known technique such as a gas phase decomposition method, a combustion method, and a deflagration method can be used. For example, in a silica sol suspension obtained by hydrolyzing and condensing an alkoxysilane with a catalyst in an organic solvent in which water is present, the solvent is removed, dried and formed into particles, and a sol-gel obtained by a known sol-gel method. Silica can be used. The organic-inorganic composite fine particles can be produced, for example, according to the description in Examples of WO2013 / 063291.

  In order to achieve both ease of toner-toner loosening and toner-flat plate slippage, it is preferable that the particle size distribution of fine particles having a number average particle diameter (D1) of primary particles of 200 to 500 nm is monodisperse. When the particle size distribution of the fine particles is monodisperse, the fine particles are easily dispersed uniformly on the surface of the toner particles.

  The half width of the particle size distribution of the fine particles A is preferably 40 nm or less, because the coefficient of variation of the number of the fine particles present becomes small. More preferably, it is 30 nm or less.

  Further, the silica surface obtained by the sol-gel method may be used after being subjected to a hydrophobic treatment, and as the hydrophobic treatment agent, a silane compound is preferably used. Examples of the silane compound include monochlorosilanes such as hexamethyldisilazane, trimethylchlorosilane and triethylchlorosilane, monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane, monoaminosilanes such as trimethylsilyldimethylamine and trimethylsilyldiethylamine, and trimethylacetoxysilane. Of monoacyloxysilane.

  The content of the fine particles having a number average particle diameter (D1) of the primary particles of 200 to 500 nm in the toner is preferably 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles. In order to keep the abundance of the fine particles A in a preferable range, the content is preferably set to the above content.

<Other external additives>
Fine particles having a number average particle size (D1) of primary particles of 200 nm or more and 500 nm or less, that is, fine particles A are external additives in the toner. Fine particles other than these fine particles (hereinafter referred to as a second external additive) may be added to the toner as an external additive.

  However, from the viewpoint of preventing the spacer effect of the fine particles A from being reduced, it is preferable to add only the fine particles A without adding an external additive having a small number average particle diameter.

  As the second external additive, it is preferable that silica fine particles or titania fine particles are subjected to a hydrophobic treatment. The number average particle diameter is preferably 5 nm or more and 40 nm or less. Examples of the method of the above-mentioned hydrophobizing treatment include a method of treating with an organosilicon compound, silicone oil, a long-chain fatty acid or the like.

  Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyl Disiloxane and the like. These are used in one kind or in a mixture of two or more kinds.

  Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, and fluorine-modified silicone oil.

<Production of toner particles>
The method for producing the toner particles is not particularly limited as long as the method can produce toner particles having a circularity of 0.960 or more. As a method for producing a toner having a high circularity, a method for directly producing toner particles in a hydrophilic medium (hereinafter, also referred to as a polymerization method), such as a suspension polymerization method, an interfacial polymerization method, or a dispersion polymerization method, or a pulverization method A method of forming the toner into a sphere by heat may be used.

  Among these, toner particles produced by a suspension polymerization method, which can realize high transferability because individual particles are substantially spherical and the distribution of charge amount is relatively uniform, are preferable.

  The suspension polymerization method is a method for producing toner particles through at least a granulation step and a polymerization step. In the granulation step, a polymerizable monomer composition having at least a polymerizable monomer, a colorant, a wax and the like is dispersed in an aqueous medium to produce droplets of the polymerizable monomer composition. In the polymerization step, the polymerizable monomers in the droplets obtained in the granulation step are polymerized. When producing the toner particles according to the present invention, it is preferable that a low molecular weight resin is contained in the polymerizable monomer composition.

  The toner is preferably a toner having toner particles having at least a core portion and a shell portion. The toner particles have a shell portion so as to cover the core portion. With such a structure, it is possible to prevent poor charging and blocking due to oozing of the core portion onto the toner particle surface. Further, it is more preferable that a surface layer having a different resin composition from the shell is present on the surface of the shell. The presence of this surface layer can further improve environmental stability, durability, and blocking resistance.

  Preferred polymerizable monomers that can be used to form the toner particles include vinyl polymerizable monomers. For example, styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p Styrene derivatives such as -n-hexylstyrene, pn-octyl, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene and p-phenylstyrene; methyl acrylate, Ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n- Acrylic polymerizable monomers such as nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate, n -Propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl Phosphate ethyl methacrylate, dibutyl phosphate Methacrylic polymerizable monomers such as methyl methacrylate; methylene aliphatic monocarboxylic esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl methyl ether; Vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  In the case of toner particles having a core-shell structure, the shell portion can be composed of a vinyl polymer formed from these vinyl polymerizable monomers or an added vinyl polymer. Among these vinyl polymers, a styrene polymer, a styrene-acrylic copolymer, or a styrene-methacrylic copolymer is preferred from the viewpoint of efficiently covering the wax mainly forming the inner or central part.

  Wax is preferred as the material constituting the core of the toner particles having the core-shell structure. Examples of usable wax components include paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method, polyolefin wax such as polyethylene and polypropylene, and Derivatives, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the derivatives include oxides, block copolymers with vinyl monomers, and graft modified products. Furthermore, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, animal waxes, and silicone resins are also wax components. Can be used as

  The toner particles can include a colorant. As the black colorant, carbon black or a magnetic material can be used. In addition, toner particles toned in each color using the following yellow / magenta / cyan colorants are used.

  Examples of the yellow colorant include compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214.

  Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269, C.I. I. Pigment Bio Red 19.

  Examples of the cyan coloring agent include a copper phthalocyanine compound and a derivative thereof, an anthraquinone compound, and a basic dye lake compound. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

  These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant is selected from the viewpoints of hue angle, saturation, lightness, light fastness, OHP transparency, and dispersibility in the toner. The addition amount of the coloring agent is, for example, 1 to 20 parts by mass per 100 parts by mass of the polymerizable monomer.

  Further, a magnetic material can be contained in the toner particles to form a magnetic toner. In this case, the magnetic material can also serve as a colorant. Examples of the magnetic material include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; and aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, and cadmium; Alloys with metals such as calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof. The magnetic material is preferably a surface-modified magnetic material. When the magnetic toner particles are prepared by a polymerization method, a magnetic material that has been subjected to a hydrophobic treatment with a surface modifier that is a substance that does not inhibit polymerization is preferable. Examples of such a surface modifier include a silane coupling agent and a titanium coupling agent. These magnetic materials preferably have a number average particle size of 2 μm or less, more preferably 0.1 μm or more and 0.5 μm or less.

  The amount of the magnetic material contained in the toner particles is from 20 parts by mass to 200 parts by mass, and particularly preferably 40 parts by mass, per 100 parts by mass of the polymerizable monomer or the binder resin. The amount is preferably 150 parts by mass or less.

<Average circularity>
The average circularity of the toner particles needs to be 0.960 or more. When the average circularity is less than 0.960, fine line reproducibility is reduced even if the cleaning property is good. It is preferable that the average circularity of the toner particles is 0.970 or more, because the reproducibility of fine lines is further improved.

  Further, when the true sphere content of the toner is 10% or more, the present invention is more effective. The true sphere content is the ratio of the number of toner particles having a circularity of 0.99 or more to the total number of toner particles, and the higher the true sphere content, the better the fine line reproducibility.

<Production of toner particles by pulverization method>
Here, a pulverization method will be described as a production method for producing toner particles.

  First, in a raw material mixing step, a predetermined amount of a polyester resin, a colorant, other additives, and the like are weighed and mixed as materials constituting the toner particles, and are mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, an FM mixer, a Nauta mixer, and a mechano hybrid (trade name, manufactured by Nippon Coke Industry Co., Ltd.).

  Next, the mixed materials are melt-kneaded to disperse a colorant and the like in the polyester resin. In the melt kneading step, a batch kneader such as a pressure kneader or a Banbury mixer or a continuous kneader can be used. A single- or twin-screw extruder has become mainstream because of its superiority in continuous production. For example, a KTK type twin-screw extruder (trade name, manufactured by Kobe Steel), a TEM type twin-screw extruder (trade name, manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (trade name, manufactured by Ikegai), a twin-screw extruder (Trade name, manufactured by KCS Inc.), co-kneader (trade name, manufactured by Bus Co., Ltd.), Kneedex (trade name, manufactured by Nippon Coke Industry Co., Ltd.) and the like. Further, the resin composition obtained by melt-kneading may be rolled with two rolls or the like, and cooled with water or the like in a cooling step.

  Next, the cooled product of the resin composition is pulverized to a desired particle size in a pulverizing step. In the pulverizing step, for example, coarse pulverization is performed using a pulverizer such as a crusher, a hammer mill, or a feather mill. Then, for example, a Kryptron system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.), a super rotor (trade name, manufactured by Nisshin Engineering Co., Ltd.), a turbo mill (trade name, manufactured by Freund Turbo Co., Ltd.) or an air jet system And pulverize with a pulverizer.

  Thereafter, if necessary, the particles are classified by using a classifier or a sieve to obtain toner particles. For example, inertial classification method elbow jet (trade name, manufactured by Nippon Mining Co., Ltd.), centrifugal force classification method turboplex (trade name, manufactured by Hosokawa Micron Corporation), TSP separator (trade name, manufactured by Hosokawa Micron Corporation), faculty (trade name, Hosokawa Micron Corporation) can be used.

  Further, the toner particles can be made spherical after pulverization. For example, a hybridization system (trade name, manufactured by Nara Kikai Seisakusho), a mechano-fusion system (trade name, manufactured by Hosokawa Micron), a faculty (trade name, manufactured by Hosokawa Micron), Meteoreinbo MR Type (trade name, Nippon Pneumatic) Manufactured).

<Fixing of fine particles to toner particles>
The following mixer can be used to externally add the external additive (fine particles) to the toner particles. That is, FM mixer, COMPOSI (trade name, manufactured by Nippon Coke Industry Co., Ltd.), super mixer (trade name, manufactured by Kawata Corporation), novirta (trade name, manufactured by Hosokawa Micron Corporation), hybridizer (trade name, manufactured by Nara Machine Co., Ltd.), etc. It is. Fine particles can be fixed to the surface of the toner particles by using such an apparatus. Among these, novilter and COMPOSI are preferred for controlling the rate of liberation of the external additive from the toner particles and for uniformly covering the external additive on the toner particles. Alternatively, the external addition device shown in FIG. 3 is preferable.
COMPOSI can increase the rotation speed of the blades compared to the conventional FM mixer, and has a collision plate, so that the adhesion of the external additive can be increased. Novirta is also a device that can increase the adhesion of external additives.

FIG. 3 is a schematic diagram illustrating an example of an external addition device (surface modification device). The surface modification device 100 has the following elements.
A main body casing 110 having a cylindrical shape.
An input section 150 on the side surface of the main casing 110 for inputting toner particles and fine particles into the main casing 110.
A dispersing rotor 120 which is located on the upper part of the main casing 110 and is a means for dispersing toner particles and fine particles.
A fixing rotor 130 provided at a lower portion of the main casing 110 and serving as a means for applying a mechanical impact to the toner particles and the fine particles dispersed by the dispersion rotor 120 to fix the fine particles to the surface of the toner particles.
A guide ring 140 at an intermediate portion between the dispersion rotor 120 and the fixed rotor 130. This is a cylindrical guide that guides the toner particles and the fine particles dispersed by the dispersion rotor 120 to the fixing rotor 130 and guides the toner having the fine particles fixed to the surface of the toner particles by the fixing rotor 130 to the dispersion rotor 120. Means.
A discharge unit 160 for discharging the toner having fine particles adhered to the surface of the toner particles on the side surface of the main body casing 110 to the outside of the main body casing 110;

  This apparatus can repeat the dispersion of the toner particles and the fine particles by the dispersion rotor 120 and the fixing of the fine particles to the surface of the toner particles by the fixing rotor 130 for a predetermined time. The dispersion rotor 120 is fixed to a drive shaft 172 driven by a dispersion rotor drive motor 171, and rotates clockwise as viewed from above the main body casing 110. The fixed rotor 130 is fixed to a drive shaft 174 driven by a fixed rotor driving motor 173, and rotates clockwise as viewed from above the main body casing 110.

  When this device is used, it is easy to fix the large-diameter external additive, which is difficult with the conventional external addition device, and the adhesion state of the fine particles is likely to be uniform. As a result, the coefficient of variation of the number of the fine particles is small. It is easy to become and is preferable.

  In order to reduce the variation coefficient of the number of the fine particles, it is preferable to perform a pre-mixing step before external addition. The apparatus for performing the pre-mixing is not particularly limited, and examples thereof include an FM mixer and a super mixer (trade name, manufactured by Kawata Corporation). Among them, the FM mixer is preferable.

<Removal of coarse particles>
In the present invention, coarse particles may be removed after external addition. Coarse particles are particles having a size of about 100 μm, and methods for removing the particles include sieving. Further, examples of the sieving apparatus used for sieving coarse particles after external addition include the following. That is, Ultrasonic (trade name, manufactured by Koei Sangyo Co., Ltd.); resonator sieve, gyro shifter (trade name, Tokuju Kogyo Co., Ltd.); Vibrasonic system (trade name, manufactured by Dalton); Sonic Clean (trade name, Shinto Kogyo Co., Ltd.) Turbo Screener (trade name, manufactured by Turbo Industries); Microshifter (trade name, manufactured by Makino Sangyo Co., Ltd.).

<Two-component developer using magnetic carrier>
The toner according to the present invention can be used as a one-component developer, but can also be used as a two-component developer by mixing with a magnetic carrier.

  Examples of the magnetic carrier include iron powder having an oxidized surface or unoxidized iron powder; metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earths; and alloy particles thereof. A commonly known magnetic material such as oxide particles; ferrite; or a magnetic material-dispersed resin carrier (a so-called resin carrier) containing a magnetic material and a binder resin holding the magnetic material in a dispersed state is used. it can.

  When the toner according to the present invention is mixed with a magnetic carrier and used as a two-component developer, the mixing ratio of the toner and the magnetic carrier should be 2% by mass or more and 15% by mass or less as the toner concentration in the developer. Is preferred.

<Method for measuring number average particle diameter of fine particles>
The number average particle diameter (D1) of the primary particles of the external additive (fine particles) is measured using a scanning electron microscope “S-4800” (trade name; manufactured by Hitachi, Ltd.). The surface of the toner to which the external additive is externally added is observed, and in a field of view magnified up to 200,000 times, the major diameter of the primary particles of 100 external additives is randomly measured to determine the number average particle diameter. The observation magnification is appropriately adjusted depending on the size of the external additive.

<Method of measuring the release rate of fine particles>
160 g of sucrose (manufactured by Kishida Chemical) is added to 100 mL of ion-exchanged water and dissolved in a water bath to prepare a concentrated sucrose solution. In a tube for centrifugation, 31 g of the above sucrose concentrate and 10 mass of a neutral detergent for cleaning a precision measuring instrument of pH 7 consisting of Contaminone N (trade name, nonionic surfactant, anionic surfactant, organic builder) % Aqueous solution, manufactured by Wako Pure Chemical Industries, Ltd.) to prepare a dispersion. 1 g of the toner is added to the dispersion, and the lump of the toner is loosened with a spatula or the like.

The tube for centrifugation is shaken with a shaker (trade name, Universal Shaker AS-1N, manufactured by AS ONE Corporation) at 350 spm for 20 minutes. After shaking, the dispersion is replaced with a glass tube (50 mL) for a swing rotor, and separated by a centrifuge (trade name: H-9R, manufactured by Kokusan) under the conditions of 3500 s ^-1 and 30 min. It is visually confirmed that the toner and the aqueous solution are sufficiently separated, and the toner separated in the uppermost layer is collected with a spatula or the like. The collected aqueous solution containing the toner is filtered with a vacuum filter, and then dried with a dryer for 1 hour or more. The dried product is disintegrated with a spatula, and the amount of the external additive is measured by X-ray fluorescence (aluminum ring diameter: 10 mm). The liberation rate is calculated from the toner obtained at this stage (referred to as “toner after water washing”) and the initial amount of the external additive of the toner.

  The measurement of the fluorescent X-ray of each element conforms to JIS K 0119-1969, and is specifically as follows.

  For the measurement, a wavelength dispersive X-ray fluorescence spectrometer “Axios” (trade name, manufactured by PANalytical) and attached dedicated software “SuperQ ver. 4.0F” for setting measurement conditions and analyzing measurement data (product) Name, manufactured by PANalytical). Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 10 mm, and the measurement time is 10 seconds. When a light element is measured, a proportional counter (PC) is used, and when a heavy element is measured, a scintillation counter (SC) is used.

  As a measurement sample, about 1 g of toner was put into a special aluminum ring for press, flattened, and 20 MPa using a tableting and compression machine “BRE-32” (trade name, manufactured by Maekawa Testing Machine Co., Ltd.). And pressurized for 60 seconds to use pellets molded to a thickness of about 2 mm. Measurement samples are prepared for each of the washed toner and the initial toner.

  The measurement is performed under the above conditions, the element is identified based on the obtained X-ray peak position, and its concentration is calculated from the count rate (unit: cps) which is the number of X-ray photons per unit time.

As a method of quantifying SiO _{2 in} the toner, a fine powder of silica (SiO ₂ ) is added to 100 parts by mass of toner particles so as to be 0.10 parts by mass, and sufficiently mixed using a coffee mill. Similarly, 0.20 parts by mass and 0.50 parts by mass of the silica fine powder are respectively mixed with the toner particles, and these are used as a sample for a calibration curve.

For each sample, a pellet for a calibration curve sample was prepared using a tablet molding compressor as described above, and when PET was used for the spectral crystal, the diffraction angle (2θ) was observed at 109.08 °. The counting rate (unit: cps) of the Si-Kα ray is measured. Here, PET means pentaerythritol. At this time, the acceleration voltage and the current value of the X-ray generator are set to 24 kV and 100 mA, respectively. A calibration curve of a linear function is obtained with the obtained X-ray count rate on the vertical axis and the added amount of SiO ₂ in each calibration curve sample on the horizontal axis.

Next, the toner to be analyzed is formed into a pellet using a tablet molding compressor as described above, and the counting rate of the Si-Kα ray is measured. Then, the content of SiO ₂ in the toner is determined from the above calibration curve.

  The rate of decrease in the amount of the external additive in the toner after washing with respect to the amount of the external additive in the initial toner calculated by the above method is defined as the release rate of the external additive.

<Method of measuring average circularity of toner particles>
The average circularity of the toner particles is measured by a flow type particle image analyzer “FPIA-3000” (trade name, manufactured by Sysmex Corporation) under the measurement and analysis conditions during the calibration operation.

  The specific measuring method is as follows. First, about 20 mL of ion-exchanged water from which impurity solids and the like have been removed in advance is placed in a glass container. About 0.2 mL of a diluent obtained by diluting the aforementioned contaminone N with ion-exchanged water about 3 times by mass as a dispersant is added thereto. Further, about 0.02 g of a measurement sample (toner particles) is added, and a dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. At that time, the dispersion is appropriately cooled so that the temperature of the dispersion is 10 ° C. or more and 40 ° C. or less. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser having an oscillation frequency of 50 kHz and an electric output of 150 W (for example, “VS-150” (trade name, manufactured by Vervocreer)) is used. A predetermined amount of ion-exchanged water is put in the water tank of the ultrasonic disperser, and about 2 mL of the contaminone N is added to the water tank.

  For the measurement, the flow type particle image analyzer equipped with “UPlanApro” (trade name, magnification 10 ×, numerical aperture 0.40) as an objective lens was used, and the particle sheath “PSE-900A” (product) was used as the sheath liquid. Name, manufactured by Sysmex Corporation). The dispersion prepared according to the above procedure is introduced into the flow type particle image analyzer, and 3,000 toner particles are measured in the HPF measurement mode in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the circle equivalent diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is obtained.

  In the measurement, automatic focus adjustment is performed using standard latex particles diluted with ion-exchanged water before the start of the measurement. Thereafter, it is preferable to perform the focus adjustment every two hours from the start of the measurement. For the standard latex particles, for example, “RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A” (trade name) manufactured by Duke Scientific is used.

  In the examples of the present application, a flow-type particle image analyzer that has been calibrated by Sysmex Corporation and has been issued a calibration certificate issued by Sysmex Corporation was used. The measurement was performed under the measurement and analysis conditions at which the calibration certificate was obtained, except that the analysis particle diameter was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

<Method of Measuring Weight Average Particle Size (D4) of Toner Particles>
The weight average particle diameter (D4) of the toner particles is measured using a precise particle size distribution measuring device and dedicated software. The measuring device is a precision particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube by a pore electric resistance method. The dedicated software is an attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) for setting measurement conditions and analyzing measurement data. Using these, the measurement is performed with 25,000 effective measurement channels, the measurement data is analyzed, and D4 is calculated.

  The electrolytic aqueous solution used for the measurement is prepared by dissolving a special grade sodium chloride in ion-exchanged water so as to have a concentration of about 1% by mass, for example, "ISOTON II" (trade name, manufactured by Beckman Coulter, Inc.). it can.

  Before the measurement and analysis, the setting of the dedicated software was performed as follows.

  In the “Change standard measurement method (SOMME) screen” of the dedicated software, the total count number in the control mode is set to 50,000 particles, the number of measurements is one, and the Kd value is “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the threshold / noise level measurement button, the threshold and the noise level are automatically set. Also, the current is set to 1600 μA, the gain is set to 2, and the electrolytic solution is set to ISOTON II, and the flash of the aperture tube after the measurement is checked.

  In the “pulse to particle size conversion setting screen” of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set from 2 μm to 60 μm.

  The specific method of measuring D4 is as follows.

  (1) About 200 mL of the aqueous electrolytic solution is placed in a 250 mL round bottom beaker made of glass exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 revolutions / second. Then, the dirt and air bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  (2) About 30 mL of the electrolytic aqueous solution is placed in a 100 mL flat-bottom glass beaker, and about 0.3 mL of a diluent obtained by diluting the above-mentioned "Contaminone N" with ion-exchanged water by 3 times as much as a dispersant is added thereto. .

  (3) 3.3 L of ion-exchanged water is put into a water tank of an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (trade name, manufactured by Nikkaki Bios), and about 2 mL of the contaminone N is added to the water tank. I do. In this ultrasonic dispersion, two oscillators having an oscillation frequency of 50 kHz are built in a state where the phases are shifted by 180 degrees, and the electric output is 120 W.

  (4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the aqueous electrolytic solution in the beaker becomes maximum.

  (5) About 10 mg of toner particles are added little by little to the aqueous electrolytic solution in the beaker of (4) while irradiating the aqueous electrolytic solution with ultrasonic waves, and dispersed. Then, the ultrasonic dispersion processing is continued for another 60 seconds. The ultrasonic dispersion is appropriately adjusted so that the water temperature of the water tank is 10 ° C. or more and 40 ° C. or less.

  (6) To the round bottom beaker of (1) set in the sample stand, the electrolytic aqueous solution of (5) in which the toner is dispersed is dropped using a pipette, and adjusted so that the measured concentration becomes about 5% by volume. I do. Then, measurement is performed until the number of particles to be measured reaches 50,000.

  (7) Analyze the measured data with the dedicated software attached to the device, and calculate the weight average particle size (D4). The “average diameter” on the analysis / volume statistical value (arithmetic average) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Method for quantifying fine particles in toner>
When measuring the content of fine particles in a toner in which a plurality of types of external additives (fine particles) are externally added to toner particles, the external additives are removed from the toner particles, and a plurality of types of external additives are isolated.・ It is necessary to collect.

Specific examples include the following methods.
(1) 5 g of toner is put in a sample bottle, and 200 ml of methanol is added.
(2) Disperse the sample for 5 minutes using an ultrasonic cleaner and peel off the external additive from the toner particles.
(3) The toner particles and the external additive are separated by suction filtration (using a 10 μm membrane filter).
(4) Perform the above (2) and (3) three times in total.

  By the above operation, the externally added external additive is separated from the toner particles. At this time, when a plurality of external additives are present, the aqueous solution containing the collected external additives is centrifuged to separate and collect the external additives. Next, the content of the inorganic fine particles can be obtained by removing the solvent, sufficiently drying with a vacuum dryer, and measuring the weight. Incidentally, since this measurement method measures the content using the specific gravity difference of the external additive, this measurement method can be used only when only one type of inorganic fine particles is contained.

<Method of Measuring Half-Width of Peak of Primary Particle in Chart of Particle Size Distribution Based on Weight of Fine Particle>
The half width of the peak of the primary particles in the chart of the particle size distribution based on the weight of the fine particles is measured by a disk centrifugal particle size distribution analyzer DC24000 (trade name, manufactured by CPS Instruments Inc.).

  First, the disk is rotated at 24000 rpm by Motor Control on CPS software (included in the disk centrifugal particle size distribution analyzer DC24000). Thereafter, the following conditions are set from the Procedure Definitions.

(1) Sample parameter
・ Maximum Diameter: 0.5 μm
・ Minimum Diameter: 0.05μm
・ Particle Density: 2.0-2.2 g / mL (density of silica; enter the value for the sample used)
・ Particle Refractive Index: 1.43
・ Particle Absorption: 0K
・ Non-Sphericity Factor: 1.1
(2) Calibration Standard Parameters
・ Peak Diameter: 0.226 μm
・ Half Height Peak Width: 0.1 μm
・ Particle Density: 1.389 g / mL
・ Fluid Density: 1.059 g / mL
-Fluid Refractive Index: 1.369
Fluid Viscosity: 1.1 cps.

After setting the above conditions, CPS Instruments Inc. Using an automatic gradient maker AG300 (trade name), a density gradient solution composed of an 8% by mass aqueous solution of sucrose and a 24% by mass aqueous solution of sucrose is prepared, and 15 mL of the solution is injected into the measurement container.
After the injection, 1.0 mL of dodecane (manufactured by Kishida Chemical Co., Ltd.) is injected to prevent evaporation of the density gradient solution, an oil film is formed, and the apparatus is kept on standby for 30 minutes or more to stabilize the apparatus.
After waiting, standard particles for calibration (weight-based central particle size: 0.226 μm) are injected into the measuring device with a 0.1 mL syringe to perform calibration. Thereafter, the collected supernatant is poured into the apparatus, and the weight-based particle size distribution is measured.

0.5 mg of Triton-X100 (trade name, manufactured by Kishida Chemical Co., Ltd.) is added to 100 g of ion-exchanged water to prepare a dispersion medium. To 10.0 g of this dispersion medium, 20 mg of sample microparticles is added and dispersed by an ultrasonic disperser.
The ultrasonic disperser incorporates two oscillators having an oscillation frequency of 50 kHz with the phases shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dispersion System Tetra 150” having an electric output of 120 W (trade name, Nikkaki Bios) Made by the company). About 3.3 L of ion-exchanged water is put into the water tank of the ultrasonic disperser, and about 2 ml of contaminone N is added to this water tank.

  The dispersion liquid in which the fine particles are dispersed is put into a beaker, set in a beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the aqueous electrolytic solution in the beaker becomes maximum. Then, the ultrasonic dispersion processing is continued for another 300 seconds. The ultrasonic dispersion is appropriately adjusted so that the water temperature of the water tank is 10 ° C. or more and 40 ° C. or less.

  Thereafter, 0.1 mL of the supernatant in the beaker is collected. For collection, a CPS company dedicated measuring instrument was installed before the all-plastic disposable syringe (Tokyo Glass Instruments Co., Ltd.) equipped with a syringe filter (diameter: 13 mm / pore size 0.45 μm) (Advantech Toyo Co., Ltd.). Use the one with a syringe needle attached. The supernatant collected by a syringe is injected into a disk centrifugal particle size distribution analyzer DC24000 (trade name, manufactured by CPS Instruments Inc.), and the particle size distribution based on the weight of the fine particles is measured. A chart of the weight-based particle size distribution obtained by the measurement is obtained. The half width of the peak of the particle size distribution in this chart is defined as the half width of the peak of the primary particles of the fine particles.

The basic configuration and features of the present invention have been described above, but the present invention will be specifically described below based on embodiments. However, this does not limit the embodiment of the present invention at all. Parts in the examples are parts by mass. Examples 5, 7, 8, and 13 are for reference.

<Fine particles>
For the fine particles, sol-gel silica and explosive silica were prepared by a conventionally known method, and surface treatment was performed with HMDS (hexamethyldisilazane). The organic-inorganic composite fine particles were produced according to the description in Examples of WO 2013/063291.
Table 1 shows the physical properties of the fine particles used.

<Inorganic fine particles (second external additive)>
As inorganic fine particles (second external additive), a silica fine powder having a number average particle diameter (D1) of primary particles of 10 nm and a BET specific surface area of 125 m ² / g is subjected to surface treatment with hexamethyldisilazane and silicone oil. What was done was used.

<Production Example 1 of Toner Particle>
710 parts of ion-exchanged water and 850 parts of a 0.1 mol / L Na ₃ PO ₄ aqueous solution are added to a _four- necked container, and the mixture is stirred at 12,000 s ⁻¹ using a high-speed stirrer TK-homomixer. C. was maintained. 68 parts of a 1.0 mol / L-CaCl ₂ aqueous solution was gradually added thereto to prepare an aqueous dispersion medium containing a fine hardly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

The following materials were prepared.
124 parts of styrene 36 parts of n-butyl acrylate 13 parts of copper phthalocyanine pigment (Pigment Blue 15: 3) 40 parts of styrene resin (1) 10 parts of polyester resin (1) (terephthalic acid-propylene oxide-modified bisphenol A (2 mol adduct) (molar ratio = 51: 50), acid value = 10 mg KOH / g, glass transition point = 70 ° C., Mw = 10500, Mw / Mn = 3.20)
-Negative charge control agent (aluminum compound of 3,5-di-tert-butylsalicylic acid)
0.8 parts wax (Fischer-Tropsch wax, endothermic main peak temperature = 78 ° C)
15 parts.

The above materials were stirred for 3 hours using an attritor, and each component was dispersed in a polymerizable monomer to prepare a monomer mixture. To this monomer mixture, 20.0 parts of 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (50% by mass of a toluene solution) as a polymerization initiator was added, and a polymerizable monomer was added. A composition was prepared. The polymerizable monomer composition was charged into the aqueous dispersion medium, and granulated for 5 minutes while maintaining the rotation speed of the stirrer at 10,000 s ^-1 . Thereafter, the high-speed stirrer was changed to a propeller stirrer, the internal temperature was raised to 70 ° C., and the reaction was carried out for 6 hours while stirring slowly.

Next, the inside of the container was heated to 80 ° C. and maintained for 4 hours, and then gradually cooled to 30 ° C. at a cooling rate of 1 ° C. per minute to obtain a slurry 1. Dilute hydrochloric acid was added to the container containing the slurry 1 to remove the dispersion stabilizer. Further, the polymer was filtered, washed and dried to obtain polymer particles (toner particles 1) having a weight average particle diameter (D4) of 6.3 μm. The true density of the toner particles was 1.1 g / cm ³ . The average circularity of the toner particles was 0.980.

<Example of manufacturing magnetic carrier>
Magnetite fine particles (spherical shape, number average particle diameter 250 nm, magnetization strength 65 Am ² / kg, specific resistance 3.3 × 10 ⁵ Ω · cm at 500 V / cm) and a silane coupling agent (3- (2-amino Ethylaminopropyl) trimethoxysilane) was prepared. The magnetite fine particles and a silane coupling agent (an amount of 3.0% by mass based on the mass of the magnetite fine particles) were introduced into the container. Then, the magnetite particles were surface-treated by high-speed mixing and stirring at a temperature of 100 ° C. or higher in this container.

The following materials were prepared.
-10 parts by mass of phenol-16 parts by mass of formaldehyde solution (37% by mass aqueous solution of formaldehyde)-84 parts by mass of the above-mentioned surface-treated magnetite fine particles The above-mentioned materials were introduced into a reaction vessel, and the temperature was adjusted to 40 ° C and mixed well.

  Thereafter, the mixture was heated to a temperature of 85 ° C. with stirring at an average heating rate of 3 ° C./min, and 4 parts by mass of 28% by mass ammonia water and 25 parts by mass of water were added to the reactor. The temperature was maintained at 85 ° C., and the polymerization reaction was performed for 3 hours to cure. The peripheral speed of the stirring blade at this time was 1.8 m / sec.

After the polymerization reaction, the temperature was cooled to 30 ° C., and water was added. The precipitate obtained by removing the supernatant was washed with water and further air-dried. The obtained air-dried product was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C., and the magnetic material was dispersed, the average particle diameter was 35 μm, and the specific resistance at 500 V / cm was 7.0 × 10 ⁷ Ω · cm. Thus, a carrier core (a) having an apparent density of 1.9 g / cm ³ was obtained.

Next, 35 parts by mass of a methyl methacrylate macromer having a weight average molecular weight of 5,000 having an ethylenically unsaturated group at one end (average value n = 50), and 65 parts by mass of cyclohexyl methacrylate monomer having cyclohexyl as a unit and having an ester site A part was prepared. These were added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a grinding stirrer. Further, 90 parts by mass of toluene, 110 parts by mass of methyl ethyl ketone, and 2.0 parts by mass of azobisisovaleronitrile were added. The obtained mixture was kept at 70 ° C. for 10 hours under a nitrogen stream to obtain a graft copolymer solution (solid content: 33% by mass). The weight average molecular weight of this solution measured by gel permeation chromatography (GPC) was 56,000. The glass transition point Tg was 94 ° C. In 30 parts by mass of the obtained graft copolymer solution, 1 part by mass of carbon black fine particles (the maximum peak particle size based on the number distribution is 30 nm, the specific resistance is 1.0 × 10 ⁻⁴ Ω · cm), and 200 parts by mass of toluene Parts were added. Then, the mixture was mixed well with a homogenizer to obtain a coat solution (resin solution).

  Next, the above-mentioned coating liquid was gradually added to 2000 g of the carrier core (a) while stirring while continuously applying shear stress. The solvent was volatilized while stirring at 70 ° C. under reduced pressure to coat the surface of the magnetic carrier core with the resin. The magnetic carrier core coated with this resin was heat-treated while stirring at 100 ° C. for 2 hours. After cooling, it was crushed and coarse particles were removed with a sieve having openings of 76 μm to obtain a magnetic carrier as a magnetic dispersion-type coated carrier.

<Example 1>
To the obtained toner particles 1 (100 parts), an external additive (3.0 parts of the fine particles 1) shown in Table 2 was added, and the conditions were set to 4000 s ^{-1 using} an FM mixer (trade name, manufactured by Nippon Coke). For 1 minute. Thereafter, external addition was performed with COMPOSI (trade name, manufactured by Nippon Coke) at 6000 s ^-1 for 4 minutes to obtain toner 1. The formulation and various physical properties of Toner 1 are as described in Table 2.

  The two-component developer was prepared by mixing the magnetic carrier manufactured as described above and the toner 1 so that the toner concentration became 10% by mass. The following evaluation test was performed on the obtained two-component developer. Table 3 shows the evaluation results.

<Evaluation test>
The evaluation was performed using a full-color copier image RUNNER ADVANCE C5051 (trade name) manufactured by Canon as an image forming apparatus. This apparatus does not have a cleaning design that assumes a conventional spherical toner.

<Toner cleaning property>
Under a low-temperature and low-humidity environment (10 ° C./14% Rh), a durability test was performed in which 10,000 sheets of ruled line images with a printing ratio of 5% were continuously output, and cleaning performance was evaluated at 1,000, 5,000, and 10,000 sheets. When a cleaning failure occurs, dirt is generated on the surface of the charging roller or on the paper by the toner in the form of vertical stripes. In the cleaning performance evaluation, the state was visually confirmed.
A: No cleaning failure observed on paper, no contamination of charging roller by toner.
B: No cleaning failure observed on paper, and contamination of the charging roller with toner.
C: After printing out 50 sheets or more, vertical streaks due to poor cleaning can be seen on the paper, but they are practically usable.
D: At the time of printout of 49 sheets or less, vertical stripes due to poor cleaning are seen on the paper.

<Charging member contamination>
Under a low-temperature and low-humidity environment (10 ° C./14% Rh), an endurance test for continuously outputting 10,000 sheets of images with a printing ratio of 20% was performed. At 1,000, 5,000 and 10,000 sheets, contamination of the charging roller due to the external additive was visually confirmed, and a halftone image was output to evaluate the charging roller contamination.
A: No charging roller contamination problem up to 10,000 sheets.
B: No charging roller contamination problem up to 5000 sheets.
C: No charging roller contamination problem up to 1000 sheets.
D: Image defects due to charging roller contamination occurred on 1000 sheets.

<Image density stability>
In the same image output test as in the evaluation of the contamination of the charging member, a solid image was output one by one each time, and the density of each image was measured. The difference between the maximum image density and the minimum image density in one obtained output image was obtained and shown based on the following evaluation criteria. The image density was measured with a color reflection densitometer (trade name: X-RITE 404, manufactured by X-Rite).
A: The image density difference is 0.1 or less.
B: The image density difference is larger than 0.1 and 0.3 or less.
C: The image density difference is larger than 0.3 and 0.5 or less.
D: The image density difference is larger than 0.5. Image streaks due to the streaks of the developing sleeve occur on the image.

<Fine line reproducibility>
Evaluation of fine line reproducibility was performed from the viewpoint of image quality. In the above image output, an image (print area ratio 4%) in which a lattice pattern with a line width of 3 pixels was printed on the entire surface of A4 paper after 10,000 images were output, and the fine line reproducibility was evaluated according to the following evaluation criteria. . The line width of 3 pixels is theoretically 127 μm. The line width of the image was measured with a microscope VK-8500 (trade name, manufactured by Keyence). The line width is measured by randomly selecting five points, and the average of the three points excluding the minimum value and the maximum value is defined as d (μm).
L (μm) = | 127−d |
Was defined.

L defines the difference between the theoretical line width of 127 μm and the line width d on the output image. Since d may be larger or smaller than 127, it is defined as the absolute value of the difference. The smaller L is, the more excellent the fine line reproducibility is.
A: L is 0 μm or more and less than 5 μm.
B: L is 5 μm or more and less than 15 μm, and a slight variation in the width of a fine line is observed.
C: L is 15 μm or more and less than 30 μm, and thin lines and scattering are observed, but are of a level that can withstand practical use.
D: L is 30 μm or more, and thin lines are broken or thickened in some places.

<Example 2>
A toner 2 was obtained in the same manner as in Example 1 except that the formulation and the external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Example 3>
Toner 3 was obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used.
Here, the device shown in FIG. 3 is used as the external additive device, so that the liberation rate of the external additive can be reduced.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Examples 4 and 5>
Toners 4 and 5 were obtained in the same manner as in Example 1 except that the prescription and external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Example 6>
A toner 6 was obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.
Explosive silica having a wide particle size distribution is used as the fine particles, and the coefficient of variation of the number of existing fine particles is slightly higher.

<Example 7>
A toner 7 was obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Example 8>
Toner 8 was obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used.
Here, a novirter is used as the external additive device, and thus the release rate of the external additive is slightly higher.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Examples 9 and 10>
Toners 9 and 10 were obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Example 11>
Toner 11 was obtained in the same manner as in Example 1, except that the formulation and the external addition conditions shown in Table 2 were used. Since the pre-external addition before the external addition was not performed, the variation coefficient of the number of the fine particles slightly increased.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Examples 12 and 13>
Toners 12 and 13 were obtained in the same manner as in Example 1 except that the formulation and the external addition conditions shown in Table 2 were used.
Various physical properties of the toner are as shown in Table 2.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

<Comparative Examples 1 to 6>
Toners 14 to 19 were obtained in the same manner as in Example 1 except that the formulation and the external addition conditions shown in Table 2 were used. Various physical properties of the toner are as shown in Table 2. In Comparative Example 6 (Toner 19), when adding the fine particles 1 to the toner particles, the above-mentioned inorganic fine particles (finely treated silica fine powder) were added.
Table 3 shows the results of the evaluation performed in the same manner as in Example 1.

Reference Signs List 100: Surface modification device, 110: Main casing, 120: Dispersion rotor, 130: Fixed rotor, 140: Guide ring, 150: Input unit, 160: Discharge unit, 171: Driving motor for the dispersion rotor, 172: For the dispersion rotor Drive shaft, 173: drive motor for fixed rotor, 174: drive shaft for fixed rotor

Claims (4)

Toner particles and toner having fine particles on the surface of the toner particles,
(I) the average circularity of the toner particles is 0.970 or more,
(Ii) the fine particles contain fine particles A having a number average particle diameter (D1) of primary particles of 200 nm or more and 500 nm or less;
(Iii) a release rate of the fine particles A from the toner particles is 15% by mass or more and 40% by mass or less;
(Iv) of the toner, wall friction angle θ is calculated from the following formula, not more than 10 ° or more on the 15 °,
θ = τ / σ
(Using the toner, .Shiguma for forming a toner powder layer A giving vertical load of 9.0kPa is in the toner powder layer A, the vertical load at which a penetration of the disk-shaped disk (kPa) Table be. tau, it represents a disc-shaped disc infested to the toner powder layer a, the shear stress obtained when to (π / 10) in rad / min (π / 36) rad rotation, measurements σ = 3 kPa.)
(V) using the toner, the toner powder layer B is formed by applying a load load 3 kPa, said the toner powder layer B, a propeller blade which rotates at a peripheral speed 100 mm / s of the outermost edge vertically is advanced, the start measurement from the position of 100mm from the bottom surface of the toner powder layer B, to the position of 10mm from the bottom surface obtained when caused to enter the propeller blades, the rotation torque and a vertical of the propeller blade total Energy Et is the sum of the load, Ru der following 300mJ than the 600 mJ,
A toner characterized in that:
The average value of the abundance of fine particles having a particle diameter of 200 nm or more and 500 nm or less in four regions in the reflected electron image of the toner surface photographed using a scanning electron microscope is defined as the fine particle abundance Er on one toner surface. When
The average value of Er is not less than 5 area% and not more than 40 area%;
In the four areas, in the reflected electron image of the toner, the chord giving the maximum length is a line segment A, and two straight lines parallel to the line segment A and separated from the line segment A by 1.5 μm are a straight line B and a straight line. C, a straight line passing through the midpoint of the line segment A and orthogonal to the line segment A is defined as a straight line D, and two straight lines parallel to the straight line D and separated from the straight line D by 1.5 μm are defined as a straight line E and a straight line F. 2. The method according to claim 1, wherein each of the four regions is a square formed by the line segment A and the straight lines B, C, D, E, and F, each side having a length of 1.5 μm. toner. Assuming that the total value of the number of fine particles having a particle diameter of 200 nm or more and 500 nm or less in the four regions is the number of fine particles present on one toner surface, the coefficient of variation = (the standard deviation of En / the standard deviation of En Average value)
3. The toner according to claim 2, wherein is 0.5 or less. 4. The toner according to claim 1, wherein the content of the fine particles A is 0.5 parts by mass or more and 5.0 parts by mass or less based on 100 parts by mass of the toner particles. 5. Toner.

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