JP2011242564A - Yellow toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yellow toner which improves charge stability and a development property and can maintain stable development and transfer properties even if many sheets of paper are printed out.SOLUTION: A yellow toner includes a toner particle containing at least binder resin, a mold release agent, polar resin and colorant, and inorganic fine powder. The toner particle contains C. I. Pigment Yellow 74 as the colorant. The recovery rate Z (25) of the yellow toner is 40% to 80% as measured by a micro-compression test, and the dielectric dissipation factor α of the yellow toner is 0.0010 to 0.0030 as measured at a frequency of 100 kHz and a temperature of 30°C.

Description

  The present invention relates to a yellow toner used in a recording method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet method.

  In electrophotography, an electrical latent image is formed on a photoreceptor by various means, and then the latent image is developed with toner to form a toner image, and the toner image is transferred to a recording material (transfer material) such as paper. The toner image is fixed on the recording material by heat and pressure to obtain a print or a copy.

  In recent years, with the development of computers and multimedia, there has been a demand for means for further increasing the speed and outputting high-definition full-color images in a wide range of fields from offices to homes. Heavy users are required to have high durability without deterioration in image quality even when copying or printing a large number of sheets at high speed. On the other hand, small offices and homes are required to obtain high-quality images and to have high durability in various environments. However, the load on the toner increases as the speed increases, and the developability and transferability are likely to deteriorate due to the deterioration of the toner particles.

  In addition, since a color image is generally formed by appropriately overlapping and developing four color toners of yellow, magenta, cyan, and black, each color toner is required to have higher development characteristics than a single color toner. That is, there is a need for a toner that can faithfully develop an electrostatic charge image, reliably transfer to a transfer material without scattering, and easily fix to a transfer material such as paper.

  On the other hand, in a digital full-color copying machine or printer, first, a color image original is color-separated by color filters of B (blue), G (green), and R (red). Thereafter, a latent image having a dot diameter of 20 μm to 70 μm corresponding to the original image is developed using Y (yellow), M (magenta), C (cyan), and Bk (black) color developers. Therefore, the colorant in each color developer greatly affects the image quality.

  In the paint field, yellow colorants are required to have high hiding power and high coloring power in order to give an impression equivalent to other colors with respect to human sensitivity, and colorants having a large primary particle diameter have been often used. On the other hand, in the toner field, as an important element of the colorant added to the toner, not only coloring power but also good transparency are cited. For this reason, a colorant having a large primary particle size that is preferably used in the paint field is difficult to satisfy these factors simultaneously, and various studies have been made so far.

  In order to have good transparency in the yellow toner, it is important that the primary particle diameter of the colorant itself is small and that the average particle diameter of the colorant in the toner is small. However, if the primary particle size of the colorant is small, the colorant itself is likely to agglomerate in the toner. In this case, OHP (overhead projector) is caused by deterioration in developability and light transmittance of the toner. ) Poor transparency. In order to solve these problems, a device has been devised that suppresses aggregation of the colorant in the toner and uniformly disperses it.

  In general, a toner containing colorant particles having a small particle size tends to have low coloring power. However, according to Patent Document 1, C.I. I. The pigment represented by CI Pigment Yellow 74 has a small primary particle size but a strong coloring power. It has been proposed that a toner excellent in transparency and coloring power can be obtained by making the dispersion state of the pigment in the toner particles favorable and having sufficient coloring power together with good transparency. However, when this pigment is used, obtaining a toner that sufficiently satisfies the transparency is limited only to the toner production method by the emulsion aggregation method, and until a pigment excellent in transparency, coloring power and developability is used. Not reached.

  Further, in order to improve the durability of the toner particles, it is necessary to discuss the durability of each toner particle, and the hardness (micro compression hardness) of each toner particle is an effective index. The hardness (micro compression hardness) of each toner particle indicates the degree of deformation (elasticity / plasticity) of the toner. Therefore, in a transfer process in which the toner can be deformed by applying pressure as in contact transfer, the micro-compression hardness of the toner can be an effective index for transferability in addition to durability.

  For example, the use of toner having an inflection point in the load-displacement curve of the micro-compression test and the load at the inflection point being larger than the load received in the developing device is superior in durability, and in the fixing process. It is disclosed that the fixing property is satisfied by simply crushing (Patent Document 2). However, when a temperature change in the developing device occurs, the durability of the toner due to a load received in the device is impaired, and the charging characteristics may deteriorate.

  In addition, copying machines and printers using electrophotography are required to have higher speed and higher image quality, and while the process speed of the machine is accelerating, the load on the toner increases and charging due to toner particle deterioration is increasing. As a result, the developability and transferability are likely to deteriorate. Therefore, in order to obtain a high-definition color image in each environment, it is necessary to obtain high chargeability, and the value of the dielectric loss tangent of the toner becomes important.

  Patent Document 3 discloses that a toner having excellent developability and transferability can be obtained by defining the dielectric loss tangent of black toner and color toner within a specific range. Certainly, by defining the dielectric loss tangent of the toner at a frequency of 100 kHz, the developability and transferability are improved. However, when printing out at higher speeds, durability tends to deteriorate, and it is still insufficient to cope with development, transferability and durability improvement in further printout speedup. Therefore, further improvement is necessary.

JP 2001-228653 A JP-A-2005-300937 JP 2006-078610 A

  An object of the present invention is to provide a yellow toner having improved charging stability and developability, and capable of maintaining stable developability and transferability even when a large number of sheets are printed out, and a method for producing the same.

The present invention is a yellow toner having yellow toner particles and inorganic fine powder containing at least a binder resin, a release agent, a polar resin and a colorant,
As the colorant, C.I. I. Pigment Yellow 74,
In a minute compression test for the yellow toner, when a maximum load of 2.94 × 10 ⁻⁴ N is applied to the toner at a measurement temperature of 25 ° C. and a load speed of 9.8 × 10 ⁻⁵ N / sec. The displacement amount (μm) obtained in the above step is the displacement amount X ₁ , and after the maximum load is applied, the displacement amount (μm) obtained by leaving for 0.1 second at the maximum load is the maximum displacement amount X ₂ . After leaving for 1 second, unloading is performed at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement (μm) obtained when the load becomes 0 is expressed as displacement X ₃ , the maximum displacement X ₂ the elastic displacement of the difference between the displacement X ₃ (X ₂ -X ₃₎ and then, the elastic displacement (X ₂ -X ₃₎ the maximum displacement X percentage of ₂ [{(X ₂ -X ₃ of ) / X _2} × 100: when the recovery ratio] was Z (25) (%), Z (25) is 80% or less 40% Satisfy the relationship,
The present invention relates to a yellow toner characterized in that α satisfies 0.0010 or more and 0.0030 or less, where α is a dielectric loss tangent tan δ at a temperature of 30 ° C. measured at a frequency of 100 kHz.

  According to the present invention, in a minute compression test for toner, durability is improved by having a specific load-displacement curve, and chargeability is improved by having a specific range of tan δ measured at a frequency of 100 kHz. . As a result, it is possible to obtain a highly durable yellow toner that can stably output high-definition and high-quality images even when many sheets are printed out at high speed.

It is a load-displacement curve in a toner microcompression test. It is a temperature-dielectric loss tangent curve in the dielectric loss tangent measurement of toner. It is an expanded sectional view of one embodiment of an ultrasonic oscillation device in the present invention. It is a system diagram of one embodiment of an ultrasonic oscillation device in the present invention. It is a system diagram of one embodiment of an ultrasonic oscillation device in the present invention. It is an expanded sectional view of one embodiment of an ultrasonic oscillation device in the present invention. It is a system diagram of one embodiment of an ultrasonic oscillation device in the present invention. It is a system diagram of one embodiment of an ultrasonic oscillation device in the present invention. It is sectional drawing of one Embodiment of the stirring apparatus provided with the screen which rotates at high speed in the reverse direction to the stirring blade which rotates at high speed in this invention. FIG. 10 is an enlarged view of FIG. 9. FIG. 10 is a system diagram of an embodiment in which the stirring device of FIG. 9 according to the present invention is incorporated in a circulation path. It is a system diagram of one embodiment using a dispersing device, a cooling means, a holding tank, and a circulation pump having a rotor and a stator in the present invention. It is sectional drawing of the dispersion apparatus of FIG. It is sectional drawing in the casing which follows the A-A 'line in FIG. It is sectional drawing in the casing which follows the B-B 'line in FIG. It is a perspective view of the rotor in a dispersing device. It is a perspective view of the stator in a dispersing device. FIG. 3 is a cross-sectional explanatory view of a process cartridge according to the present invention. It is a schematic block diagram of an example of the apparatus which implements the image forming method of this invention. It is a partial cross section figure of the dispersion apparatus used in Example 39 in this invention. It is a principal part schematic sectional drawing of the dispersion apparatus of FIG. It is a principal part schematic plan view of the dispersion apparatus of FIG.

The present invention is a yellow toner having yellow toner particles and inorganic fine powder containing at least a binder resin, a release agent, a polar resin and a colorant, wherein C.I. I. Pigment Yellow 74, and a maximum compression load of 2.94 × 10 ⁻⁴ N at a loading speed of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 25 ° C. in a minute compression test for the toner. The displacement amount (μm) obtained when the toner is completely applied to the toner is the displacement amount X ₁ , and after the maximum load is applied, the displacement amount (μm) obtained by allowing the maximum load to stand for 0.1 second is the maximum displacement. The amount X _{2 is} allowed to stand for 0.1 second, then unloaded at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement amount (μm) obtained when the load becomes 0 is expressed as the displacement amount X _3. , The difference between the maximum displacement amount X ₂ and the displacement amount X ₃ is an elastic displacement amount (X ₂ −X ₃ ), and the percentage of the elastic displacement amount (X ₂ −X ₃ ) with respect to the maximum displacement amount X ₂ [{ (X ₂ −X ₃ ) / X ₂ } × 100: Restoration rate] is Z (25) (%), Z (25) satisfies the relationship of 40% to 80%, and when the dielectric loss tangent tan δ at a temperature of 30 ° C. measured at a frequency of 100 kHz in the toner is α, α is 0.0010 to 0.0030. It is characterized by satisfaction.

  From the viewpoint that the colorant of the yellow toner of the present invention has sufficient colorant with good transparency, C.I. I. Pigment Yellow 74 is used.

  C. I. Pigment Yellow 74 is weak to heat, and in the toner manufacturing method by the pulverization method, the structure of the pigment changes at the temperature at the time of melt kneading, and the hue angle fluctuates. In contrast, a method for producing a toner in an aqueous medium that does not require heat to change the structure is disclosed in C.I. I. This is advantageous when the Pigment Yellow 74 is used. In particular, the suspension polymerization method is preferable because it easily develops toner characteristics to meet the recent demands for high developability and fixability. However, C.I. I. Pigment Yellow 74 is a colorant having good dispersibility in an aqueous system. A colorant that is well dispersed in an aqueous system has poor dispersibility in the resin and cannot be present uniformly. As a result, the chargeability of the toner is deteriorated and the development characteristics are deteriorated due to contamination of the developing member. Further, in continuous printing, the fixing member is contaminated and fixing characteristics are deteriorated.

  We have described C.I. I. Pigment Yellow 74, when the Z (25) value and the α value are within a specific range in a micro-compression test for toner, C.I. I. It is possible to obtain a highly durable yellow toner that can continue to output high-definition and high-quality images even when printing at high speed for a long period of time while maintaining the high coloring power characteristic of Pigment Yellow 74. I found.

The value of Z (25) can satisfy the above relationship by using, for example, the following method, but is not limited thereto.
(1) When the toner particles are produced in an aqueous medium, the toner particles contain a polar resin, which will be described later, to form a shell layer made of the polar resin. Furthermore, the polar resin is selected in consideration of compatibility with the binder resin forming the core layer.
(2) After producing core particles of toner particles in an aqueous medium, a monomer constituting a polar resin is added and seed polymerization is performed to form a shell layer.
(3) Polar resin fine particles having a volume average particle size smaller than that of the core particles are mechanically attached to the core particles. Alternatively, polar resin fine particles having a small volume average particle diameter are attached to the core particles by aggregation in an aqueous medium and fixed by heating.

  By the above-described method, the toner particles have a core-shell structure, so that a shell layer having an optimum hardness can be provided, and durability is improved.

In the micro-compression test for the toner in the present invention, the evaluation is performed by applying a small load to one toner particle in comparison with the conventional measurement method having a maximum load of 2.94 × 10 ⁻⁴ N. It measures hardness and restoration rate.

  In other words, in the toner of the present invention, the value of Z (25) is an index indicating how much the toner surface layer returns to the original state when unloaded after applying the maximum load at a measurement temperature of 25 ° C. is there. When the value of Z (25) is less than 40, the toner is likely to be deformed by the stress received in the developing device, and the external additive is embedded in the toner and the developability and transferability are likely to be lowered. On the other hand, when the value of Z (25) exceeds 80, the vicinity of the toner surface layer is difficult to deform, and therefore, the external additive is difficult to adhere to the toner particle surface. Tends to be liberated, and the developability and transferability tend to decrease.

  On the other hand, in the toner of the present invention, when the dielectric loss tangent tan δ at a temperature of 30 ° C. measured at a frequency of 100 kHz is α, α means the charging characteristics of the toner. When α is smaller than 0.0010, overcharging of the toner is easily promoted, so that image density thinness, density unevenness, and dropout due to toner accumulation on the shielding member are likely to occur. When α is larger than 0.0030, the charge amount of the toner is attenuated, resulting in problems such as toner scattering, fogging, and transferability deterioration.

  The relative dielectric constant and dielectric loss tangent tan δ of the toner of the present invention can be changed depending on the type, amount of addition, and dispersion state of the pigment and charge control agent contained in the toner.

  In order to further improve the durability, when the dielectric loss tangent tan δ at a temperature of 60 ° C. measured at a frequency of 100 kHz is β, the value of β needs to be 0.0010 or more and 0.0040 or less. β means a charging characteristic at a high temperature.

  When a large number of sheets are printed out at high temperature and at high speed, the temperature in the printer body may rise to around 60 ° C. At this time, when β is smaller than 0.0010, the charge amount distribution becomes too wide, causing problems such as fogging and scattering, thin image density, poor coating on the developer carrier, and when β is larger than 0.0040. This causes problems such as toner scattering and fogging in a high humidity environment, and deterioration in transferability.

The toner of the present invention is subjected to a maximum load of 2.94 × 10 ⁻⁴ N at a load speed of 9.8 × 10 ⁻⁵ N / sec at a measurement temperature of 50 ° C. in the minute compression test. The amount of displacement (μm) obtained when finished is the amount of displacement X ′ ₁ , and after the maximum load is applied, the amount of displacement (μm) obtained by leaving for 0.1 second at the maximum load is the amount of maximum displacement X ′ 1. _2. After leaving for 0.1 seconds, unload at a unloading speed of 9.8 × 10 ⁻⁵ N / sec. The displacement (μm) obtained when the load becomes zero is the displacement X ′ ₃ , the maximum The difference between the displacement amount X ′ ₂ and the displacement amount X ′ ₃ is the elastic displacement amount (X ′ ₂ −X ′ ₃ ), and the percentage of the elastic displacement amount (X ′ ₂ −X ′ ₃ ) with respect to the maximum displacement amount X ′ ₂ . When [(X ′ ₂ −X ′ ₃ ) / X ′ ₂ × 100: restoration rate] is Z (50) (%), Z (50) satisfies the relationship of 10% to 55%. I prefer There. By satisfying the above relationship, the toner has an appropriate hardness even at a high temperature, and the durability is improved.

  For example, in the suspension polymerization method, the above Z (50) satisfies the above range by adjusting the glass transition temperature, the weight average molecular weight of the polar resin or the binder resin of the toner, or the addition of a crosslinking agent. Is possible.

  Next, a measurement method of the micro compression test will be described with reference to FIG.

  FIG. 1 is a profile (load-displacement curve) when the toner of the present invention is measured in a micro-compression test. The horizontal axis represents the amount of displacement of the toner and the vertical axis represents the amount of load applied to the toner.

For the micro compression test in the present invention, an ultra micro hardness tester ENT1100 manufactured by Elionix Co., Ltd. was used. The working indenter was measured using a 20 μm × 20 μm square flat indenter. 1-1 in the figure is an initial state (origin) before starting the test, and the load is applied at a load speed of 9.8 × 10 ⁻⁵ N / sec with respect to the maximum load of 2.94 × 10 ⁻⁴ N. Multiply. Immediately after reaching the maximum load, the state is 1-2, and the amount of displacement at this time is X ₁ (μm). Leave it under that load for 0.1 second in the state of 1-2. The state immediately after the end of standing is 1-3, and the maximum displacement at this time is X ₂ (μm), and further, the load is applied at the unloading speed of 9.8 × 10 ⁻⁵ N / sec through the maximum load. When the load decreases to 0 N, the state is 1-4. The amount of displacement at this time is X ₃ (μm).

Z (25) indicating the percentage of the elastic displacement amount (X ₂ −X ₃ ) with respect to the maximum displacement amount X ₂ (hereinafter also referred to as the restoration rate (%)) is {(X ₂ −X ₃ ) / X ₂ } × 100 As sought. Further, the value of Z (50) is the maximum displacement amount X ′ ₂ obtained in the same manner as the measurement method of Z (25), except that it is measured at a measurement temperature of 50 ° C. in a minute compression test for toner. is a value obtained from the displacement X _'3.

  The actual measurement is performed by applying toner on the ceramic cell, blowing air so that the toner is dispersed on the ceramic cell, and then setting the ceramic cell on an ultra-micro hardness meter.

  In the measurement, the ceramic cell was brought into a temperature-controllable state, and the temperature of the ceramic cell was taken as the measurement temperature. That is, Z (25) was measured at a cell temperature of 25 ° C., and Z (50) was measured at a cell temperature of 50 ° C. The temperature of the ceramic cell was adjusted by placing the ceramic cell in an ultra-micro hardness tester and allowing it to stand for 10 minutes or more after the ceramic cell reached the measurement temperature.

  For the measurement, while looking through a microscope attached to the ultra-micro hardness meter, a toner having one toner particle on the measurement screen (horizontal width: 160 μm, vertical width: 120 μm) was selected. In order to eliminate the error of the displacement amount as much as possible, a toner having a number average particle diameter D1 of ± 0.20 μm was selected and measured. An arbitrary toner is selected from the measurement screen, and the major and minor diameters of the toner particles are measured using a software attached to the ultra-hardness meter ENT1100 as the toner particle diameter measurement means on the measurement screen. A toner having an aspect ratio [(major axis + minor axis) / 2] calculated from them having a D1 of ± 0.20 μm was selected and measured.

  Regarding the measurement data, 100 arbitrary particles were selected and measured, and the average value of Z (25) and Z (50) obtained as a measurement result was obtained.

  The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after 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 to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4). The “average diameter” on the “analysis / number statistics (arithmetic average)” screen when the graph / number% is set in the dedicated software is the number average particle diameter (D1).

  Next, a method for measuring the dielectric loss tangent tan δ will be described.

  Using a 4284A Precision LCR meter (manufactured by Hewlett-Packard Company), the dielectric loss tangent (tan δ = ε ″ / ε ′) is calculated from the measured value of the complex dielectric constant at a frequency of 100 kHz.

0.5 g of the toner is weighed and molded into a disk-shaped measurement sample having a diameter of 25 mm and a thickness of 1 mm or less (preferably 0.5 to 0.9 mm) by applying a load of 21560 kPa (220 kg / cm ² ) for 1 minute. . This measurement sample is mounted on ARES (manufactured by Rheometric Scientific F.E.) equipped with a dielectric constant measuring jig (electrode) having a diameter of 25 mm. Thereafter, with a load of 0.49 N (50 g) applied, the frequency is constant, and the sample is heated to a temperature of 140 ° C. while taking a measurement value every 30 seconds from a temperature of 30 ° C. at a rate of 5 ° C./min. The temperature-dielectric loss tangent curve of the toner thus obtained is a curve as shown in FIG. The values of tan δ at 30 ° C. and 60 ° C. were read from this curve, and the values of α and β were obtained.

  The method for producing the toner particles used in the present invention is not particularly limited, and the toner particles can be produced by a conventional toner production method. That is, it can be produced by a production method in which granulation is performed in an aqueous medium, such as a pulverization method in which a toner is produced through kneading, pulverization, and classification steps, a suspension polymerization method, an emulsion polymerization method, and a suspension granulation method It is.

  Among these, the suspension polymerization method is particularly preferable as the one that easily exhibits the effects of the present invention. In this suspension polymerization method, a polymerizable monomer is uniformly dissolved or dispersed with a wax and a colorant (and a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as necessary) to achieve polymerization. A monomer composition is used. Thereafter, the polymerizable monomer composition is dispersed in an aqueous medium containing a dispersant using an appropriate stirrer, and a polymerization reaction is performed to obtain toner particles having a desired particle size. . The polymerization initiator may be added simultaneously with the addition of other additives to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Also, a polymerization initiator dissolved in a polymerizable monomer or solvent can be added immediately after granulation and before starting the polymerization reaction. After the polymerization, the toner particles are filtered, washed and dried by a known method, and if necessary, a fluidity improver is mixed and adhered to the surface to obtain the toner of the present invention.

The yellow toner of the present invention is preferably obtained by mixing the polymerizable monomer composition by any of the following methods.
(1) A dispersion step in which at least a colorant is dispersed in a polymerizable monomer to obtain a colorant-containing monomer, and a dissolution step in which at least a resin is dissolved in the polymerizable monomer to obtain a resin-containing monomer are obtained. It has the adjustment process which mixes a colorant containing monomer and a resin containing monomer, and obtains an adjustment liquid. And it is a yellow toner obtained by the manufacturing method of the toner particle which has at least the granulation process which disperse | distributes the said adjustment liquid to an aqueous dispersion, and produces | generates the particle | grains of a polymerizable monomer composition. The adjustment step is performed using an ultrasonic oscillator, and the adjustment agent is obtained by mixing the colorant-containing monomer and the resin-containing monomer.
(2) The adjustment step is obtained by a production method characterized in that the colorant-containing monomer and the resin-containing monomer are mixed with a stirrer having high-speed shearing force in the liquid to obtain an adjustment liquid. Yellow toner. The stirring device includes a stirring blade that rotates at a high speed and a stirring chamber formed by a screen that rotates at a high speed in a direction opposite to the stirring blade around the stirring blade. And it is characterized by mixing the said coloring agent containing monomer and the said resin containing monomer by being comprised so that an adjustment liquid may eject from the said stirring chamber, It is characterized by the above-mentioned.
(3) The adjustment step is performed so that the stators having the same shape as the rotor in which the ring-shaped protrusions having a plurality of slits are formed in a concentric circle are maintained at regular intervals and mesh with each other. It is a yellow toner obtained by a manufacturing method characterized in that an adjustment liquid is obtained by an installed mixing device. The mixing apparatus is characterized in that the adjustment liquid is repeatedly introduced and discharged in the apparatus and circulated, and the adjustment liquid is obtained by mixing the colorant-containing monomer and the resin-containing monomer.

  The polymerizable monomer composition is obtained by mixing a colorant-containing monomer in which at least a colorant is dispersed in a polymerizable monomer and a resin-containing monomer in which at least a resin is dissolved in the polymerizable monomer. When obtaining, it carries out using the said ultrasonic oscillation apparatus, a stirring apparatus, and a mixing apparatus. This suppresses the pigment shock of the colorant in the step of obtaining the polymerizable monomer composition, and evenly mixes the polar resin and various materials as compared with the prior art, and further, the colorant is in a fine and uniform state. Can be dispersed. Then, by carrying out the polymerization reaction using the polymerizable monomer composition thus obtained, it becomes uniform from the presence state of the polar resin near the surface of the toner to the presence state of the colorant in the internal structure. Cheap. For this reason, the durability of the toner of the present invention is improved, and not only is contamination of the member less likely to occur, but also the charging property is high and the toner tends to be uniform.

  The ultrasonic oscillator preferably used in the present invention will be described below.

  FIG. 3 is an enlarged cross-sectional view of the ultrasonic oscillator, and FIG. 4 is a system diagram in which the apparatus main body is incorporated.

FIG. 3 will be described below.
(1): Ultrasonic oscillator, (2): Ultrasonic vibrator, (3): Ultrasonic irradiation unit.

FIG. 4 will be described below.
(11): Dispersion tank.
(12): Dissolution tank.
(13): Adjustment tank, (13-1): Liquid feed pump, (13-2): Pressure gauge, (13-3): Thermometer, (13-4): Stirrer, (13-5): Back pressure valve, (13-6): Circulation line.
(14): Ultrasonic oscillator, (14-1) Ultrasonic vibrator, (14-2): In an ultrasonic processing chamber having a processed material inlet at the top and a processed material outlet at the bottom is there.

  Moreover, (11): Dispersion tank, (12): Adjustment tank, (13): Dissolution tank, (14-2): The ultrasonic processing chamber has a jacket structure, so that the processed product can be cooled and heated. is there.

  In FIG. 5, two ultrasonic devices are installed in series. The other configuration is the same as that of FIG.

  FIG. 6 is an enlarged cross-sectional view of another ultrasonic oscillator usable in the present invention, and FIG. 7 is a system diagram in which the ultrasonic oscillator of FIG. 6 is incorporated.

  The system shown in FIG. 4 is an example of the present invention, and the adjustment tank may be used as a dispersion tank or a dissolution tank. An example is shown in FIG.

  This will be described in more detail below.

  FIG. 4 is a system diagram incorporating the apparatus main body. A colorant-containing monomer in which at least a colorant is dispersed in the polymerizable monomer from the dispersion tank (11), and a resin in which at least the resin is dissolved in the polymerizable monomer from the dissolution step (12). The containing monomer is charged into the adjustment tank (13). While stirring with the stirring device (13-4), the pump (13-1) is operated to circulate the processed material in the circulation line (13-6) and the ultrasonic processing chamber (14-2), and the ultrasonic wave Start the oscillator. Moreover, at the time of ultrasonic dispersion | distribution, a processed material is adjusted to arbitrary temperature with the jacket of an adjustment tank (13) and an ultrasonic treatment chamber (14-2).

  An example of the shape of the ultrasonic oscillator used in the present invention is shown in FIGS. The ultrasonic oscillator preferably used in the present invention has a vibrator for irradiating ultrasonic waves having a cylindrical structure having a plurality of concentric convex portions in the circumferential direction as shown in FIG. It is that. In this structure, when the processed material passes through the ultrasonic processing chamber (14-2), the processing object is subjected to ultrasonic treatment for the number of times corresponding to the number of stages of the ultrasonic irradiation unit, so that dispersion of the processed material is very small. It is uniform and can reach a predetermined dispersion state in a short time as compared with the prior art.

  Next, the circulation amount and the pressure in the ultrasonic processing chamber (14-2) are adjusted by the back pressure valve (13-5) that adjusts the pressure in the pump (13-1) and the ultrasonic processing chamber (14-2). To do. The minute bubbles in the processed material repeatedly expand and contract with the movement of the vibrator. At this time, cavitation occurs when the microbubbles that have been decompressed and expanded to a vacuum state are pressurized again and collapse. Since the effect of this cavitation is more effective as the pressure difference is larger, it is preferable that the pressure in the sonication chamber (14-2) is set to an optimum pressurized state. That is, it is preferable that the pressure in the ultrasonic treatment chamber (14-2) at the time of the adjustment step is in a range of 20 kPa to 200 kPa. If it is less than 20 kPa, energy is absorbed by the shrinkage and splitting of the bubbles contained in the treated product (49), which is not preferable because the efficiency of dispersion is lowered. If it exceeds 200 kPa, the ultrasonic oscillator is likely to be overloaded, which is not preferable in terms of safety and device reliability.

  At the time of the adjustment step, the portion where the ultrasonically processed product is discharged again into the adjustment tank is located in the processed product in the adjustment tank, and the ultrasonically processed product is a gas. It is preferable to return to the processed material without being involved. The foaming of the treated product lowers the efficiency of the ultrasonic treatment and at the same time adversely affects the next granulation step. That is, in the granulation step of dispersing the adjustment liquid in an aqueous dispersion to form particles of the polymerizable monomer composition, if bubbles are mixed in the adjustment liquid by foaming, Since the shearing force for generation is absorbed and causes a broadening of the particle size distribution, it is not preferable.

In the adjustment step, when the output per ultrasonic oscillation device is A (W) and the ultrasonic irradiation area per ultrasonic oscillation device is B (cm ² ), A ≧ 2000 and A / B is preferably in the range of 25 ≦ A / B ≦ 70. If A is less than 2000, the scale is too small as a mass-produced machine, so the number of installed units increases, and the production efficiency is low due to deterioration in maintainability and installation space, which is not preferable. When A / B is less than 25, ultrasonic energy is small and dispersion efficiency is poor, and when it exceeds 70, the consumption of the vibrator due to erosion is severe, the increase in quality fluctuation due to the change in output due to consumption, and contamination of the product Nation is large and not preferable.

  In the adjustment step, it is preferable that the amount of adjustment liquid to be subjected to ultrasonic treatment is C (kg) and the total output of the ultrasonic oscillator is D (kW), and that 50 ≦ C / D ≦ 200. In the region where C / D exceeds 200, the irradiation energy is too small, and it is difficult to achieve a desired dispersion level. On the other hand, if it is less than 50, the dispersion state tends to be saturated and becomes excessive energy, which is not preferable for energy saving.

  In the present invention, at the time of scale up, by using a plurality of ultrasonic oscillators in series, in parallel, or in series and in parallel, the ultrasonic irradiation efficiency to the processed material is not reduced. Capable of handling capacity. In the present invention, it is particularly preferable to use a plurality of devices in series, and FIG. 5 shows an example in which ultrasonic generators are connected in series. When a plurality of ultrasonic devices are used in series, the residence time of the processed product in the ultrasonic irradiation unit becomes long. In that case, since the dispersion level per one pass is higher than in the case of dispersion with one ultrasonic oscillator, it is difficult for pigment shock to occur again, and the final dispersion level becomes higher.

  Moreover, the cooling structure of the converter part (converting high-frequency power into mechanical vibration) of the ultrasonic oscillator used in the present invention is preferably an air-cooled type rather than a water-cooled type. When the ultrasonic oscillator is used in the explosion-proof area, if the cooling of the conversion unit is performed by water cooling, if the cooling water leaks, there is a possibility of electric leakage, which is not preferable.

  Specific examples of the ultrasonic oscillator include the UIP series commercialized by Dr. Heelscher (Germany). Among these, UIP1000, 2000, 4000, 8000, 16000, etc. are preferable because they have a large ultrasonic processing capability and are easy to cope with mass production.

  In the following, a stirrer having a high-speed shearing force preferably used in the present invention will be described with reference to FIG. 9, and an enlarged view of the stirrer will be described with reference to FIG. Further, a dispersion system in which the agitation apparatus is incorporated in a circulation path will be described with reference to FIG. However, the stirring device used in the present invention is not limited to this.

  9, 10, and 11, 1 is a stirring blade that rotates at high speed, 2 is a screen that rotates around the stirring blade 1 in a direction opposite to the stirring blade 1, and 3 is formed by the stirring blade 1 and the screen 2. Stirring chambers 3 and 4 are preparation tanks, 5 is a discharge port provided on the screen 2, 6 is a jacket, 7 is a holding tank, 8 is a stirring blade, 9 is a circulation pump, 10 is a dispersion vessel inlet, and 11 is a suction port. , 12 is a discharge port, 13 is a heat exchanger, 14 is a flow meter, 15 is a pressure regulating valve, 16 is a lower motor, 17 is an upper motor, 18 is a lid, 19 is a support cylinder, 20 is an upper rotating shaft, 21 Is a mechanical seal, 22 is an upper housing, 23 is a partition plate, 24 is a lower rotating shaft, 25 is a pressure gauge, and 26 is a thermometer.

(About the stirring device of FIGS. 9 and 10)
In the preparation tank 4, a colorant-containing monomer in which at least a colorant is dispersed in the polymerizable monomer from the dispersion step and a resin-containing single amount in which at least the resin is dissolved in the polymerizable monomer from the dissolution step Add a pair to make a preparation. The prepared liquid is subjected to a shearing force in a minute gap between the inner wall of the stirring blade 1 and the tip of the blade as the stirring blade 1 rotates at high speed inside the portion of the stirring chamber 3 where the discharge port 5 is provided. . Further, every time the discharge port 5 of the stirring chamber 3 that rotates in the reverse direction through the minute gap between the blade tips passes in front of the blade tips, the prepared solution is sheared between them.

  And since this discharge port 5 rotates in the reverse direction to the rotation direction of the stirring blade 1, both relative rotation speed can be raised and the shear force concerning a preparation liquid can be raised. As a result, the dispersion of the prepared liquid is extremely less uneven than in the past, and a uniform dispersion state can be achieved.

  Furthermore, since the part provided with the discharge port 5 in the stirring chamber 3 rotates in the direction opposite to the rotation direction of the stirring blade 1, the fluid discharge position changes with the rotation, and in the preparation tank 4. The prepared solution circulates well. Further, since the diameter of the portion provided at the discharge port in the stirring chamber 3 becomes smaller as it goes downward, the peripheral speed of rotation is large in the upper portion having a larger diameter, and the rotation is performed in the lower lower portion. The peripheral speed is small. As a result, when the fluid is discharged from the discharge port 5, the circumferential speed given to the fluid differs vertically, and the flow of the difference in speed further promotes the circulation of the preparation liquid.

  In addition, since this flow is added to the discharge flow caused by the rotation of the stirring blade 1 that rotates with a small gap from the discharge port 5, a faster discharge flow can be obtained, and the entire circulation is further promoted. . By such good circulation, the opportunity for the preparation liquid to pass through the minute gaps described above increases, and dispersion unevenness can be reduced.

  The preparation tank 4 has a jacket structure. By flowing a cooling medium in the jacket 6, the temperature of the preparation liquid that has risen due to the shear inside the preparation tank can be lowered.

(About the stirring system of FIG. 11)
The prepared liquid introduced into the holding tank 7 and mixed by the installed stirring blade 8 is supplied from the preparation tank inlet 10 through the circulation pump 9 and introduced into the suction port 11. Next, the preparation liquid introduced from the suction port 11 passes through the above-described minute gap and is discharged from the discharge port 5. The discharged preparation liquid circulates in the preparation tank 4, is then discharged from the discharge port 12, and returns to the holding tank 7 via the heat exchanger 13. Circulation is repeated in which the preparation liquid returned to the holding tank 7 is introduced again into the preparation tank inlet 10. By repeating the circulation of the cycle between the agitator and the holding tank 7, the prepared liquid is uniformly and efficiently dispersed. Since the holding tank 7 has a jacket structure, the processed material can be cooled and heated.

  The processing flow rate is measured by a flow meter 14 installed in the circulation path. Further, it is possible to apply a back pressure by the pressure adjusting valve 15. By applying the back pressure, it becomes possible to suppress the occurrence of cavitation due to the rotation of the stirring blade 1 and the screen 2, and it is possible to further apply a shearing force to the treatment liquid. As a result, the processed product can be finely and uniformly dispersed, and therefore, back pressure can be suitably applied in the present invention.

  When the circulation path is used, the circulation of the cycle between the stirrer and the holding tank is added to the above-described good circulation in the preparation tank 4, so that the preparation liquid can be dispersed more uniformly and efficiently. In the present invention, it is preferably used.

  As the above-mentioned stirring device, for example, Creamix W Motion (manufactured by M Technique Co., Ltd.) can be preferably used, but this is not restrictive.

  The peripheral speed of the stirring blade and the screen of the stirring device in the present invention is the peripheral speed of the maximum diameter of the stirring blade and the screen.

  Further, if the peripheral speed of the stirring blade 1 of the stirring device described above is E (m / s) and the peripheral speed of the screen 2 is F (m / s), the range is 15 ≦ E ≦ 60 and 15 ≦ F ≦ 60. It is preferable to carry out the dispersion of the prepared solution. When the stirring blade 1 and the screen 2 are smaller than 15, respectively, it is difficult to reach a desired dispersion level. Moreover, when each exceeds 60, since a dispersion | distribution state shows a saturation tendency and it becomes excess energy, it is unpreferable on energy saving. Moreover, when excessive temperature rise is suppressed using the above-mentioned cooling means, since the load to a cooling means will increase, it is unpreferable.

  Further, in the present invention, the peripheral speed of the stirring blade 1 is E, the peripheral speed of the screen 2 is F, and the relative peripheral speed “E + F” (m / s) is 40 ≦ E + F ≦ 80. This is preferable from the viewpoint of balancing the apparatus load.

  Hereinafter, a mixing apparatus including a rotor and a stator preferably used in the present invention will be described with reference to the drawings.

  FIG. 12 shows a system incorporating a mixing apparatus having a rotor and a stator used in the present invention, and FIG. 13 shows a side view of the main body of the mixing apparatus used in the present invention. 14 and 15 are cross-sectional views of the main body of the mixing device, which are a cross-sectional view taken along the line A-A 'in FIG. 12 and a cross-sectional view taken along the line B-B' in FIG. FIGS. 16 and 17 show a perspective view of a rotor and a perspective view of a stator, respectively, of the mixing device.

  Hereinafter, the mixing apparatus will be specifically described.

  In FIG. 12, a coloring agent-containing monomer in which at least a colorant is dispersed in the polymerizable monomer from the dispersing step in the holding tank 8 and a resin in which at least the resin is dissolved in the polymerizable monomer from the dissolving step. A single monomer pair is added to prepare a preparation. The introduced preparation liquid is supplied from the inlet of the mixing device via the circulation pump 10. In the mixing device, the prepared solution passes through the slits of the rotor 25 and the stator 21 provided in the casing 2 and is centrifuged. Discharged in the direction. When the preparation liquid passes through the mixing device, the preparation liquid is mixed by compression in the centrifugal direction caused by displacement of the slits of the rotor and the stator, impact by discharge, and impact by shear between the rotor and the stator. The shape of the rotor and stator used in the present invention is a shape in which ring-shaped protrusions having a plurality of slits are formed in multiple stages on concentric circles, and are coaxially arranged so as to mesh with each other at a constant interval. It is preferable that it is installed in.

  Since the rotor and the stator are arranged so as to mesh with each other, the short path is reduced and the preparation liquid can be sufficiently dispersed. In addition, since the rotor and the stator are alternately present in multiple stages in the concentric direction, a large amount of shear and impact are applied when the preparation liquid proceeds in the centrifugal direction, so that the dispersion level can be further increased. Since the holding tank 8 has a jacket structure, the processed product can be cooled and heated.

  The circumferential speed of the rotor and the stator in the present invention is the circumferential speed of the maximum diameter of the rotor and the stator. In the present invention, when the peripheral speed of the rotor 25 is G (m / s), it is preferable that the prepared liquid is mixed by rotating at 20 ≦ G ≦ 60. More preferably, the circumferential speed G of the rotor is 30 ≦ G ≦ 40. If the circumferential speed G of the rotor is 20 ≦ G ≦ 60, the shock caused by the compression and discharge of the prepared liquid in the centrifugal direction caused by the displacement of the slits of the rotor and the stator and the impact caused by the shear between the rotor and the stator And a high degree of dispersion is achieved. As a result, the dispersion of the prepared liquid is extremely less uneven than in the past, and a uniform dispersion state can be achieved.

  When the circumferential speed G of the rotor is smaller than 20 m / s, the impact due to the compression and discharge in the centrifugal direction and the impact due to the shear between the rotor and the stator are reduced, and it is difficult to reach a desired dispersion level. In addition, with the passage of time, a preparation solution having poor dispersion stability in which the colorant particles aggregate is often generated. Further, when the circumferential speed G of the rotor is larger than 60 m / s, a large pressure loss occurs when discharging from the slits of the rotor and the stator, so that not only a sufficient flow rate cannot be secured but also solid matter such as a colorant. And the polymerizable monomer may be separated, which is not preferable.

  As the above-mentioned mixing device, for example, Cavitron (manufactured by Eurotech) can be suitably used, but this is not a limitation.

  Moreover, in the said adjustment process, it is preferable that content of resin is 10 to 55 mass parts with respect to 100 mass parts of polymerizable monomers. If it is less than 10 parts by mass, when the colorant-containing monomer prepared in the dispersion step and the resin-containing monomer prepared in the dissolution step are mixed in the adjustment step, pigment shock is present in the adjustment solution. Hard to occur. Even if it occurs, there is little merit of installing an ultrasonic device because it is at a level where it can be re-dispersed by a known shear force of a stirring blade or the like. If it exceeds 55 parts by mass, the viscosity of the adjustment liquid increases significantly, so that the adjustment liquid tends to remain in the piping. As a result, the fluctuation of the discharge amount of the adjustment liquid increases to the granulation process in which the adjustment liquid is dispersed in an aqueous dispersion to produce particles of the polymerizable monomer composition, which is the next process. The fluctuation of the particle size distribution of the particles of the monomer composition is increased, and the yield rate is decreased, which is not preferable. Furthermore, there is a concern about problems such as blockage of piping due to the progress of adhesion, which is not preferable.

  The materials used in the present invention will be described below.

  Examples of the binder resin used in the present invention include styrene-acrylic copolymers, styrene-methacrylic copolymers, epoxy resins, and styrene-butadiene copolymers. Examples of the polymerizable monomer used in the production of the binder resin include vinyl polymerizable monomers capable of radical polymerization. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Examples of the polymerizable monomer include the following.

  Styrene; Styrenic monomers such as o- (m-, p-) methylstyrene, m- (p-) ethylstyrene; methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, Propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, stearyl acrylate, stearyl methacrylate, behenyl acrylate, behenyl methacrylate, 2-ethylhexyl acrylate, Acrylic acid ester monomers such as 2-ethylhexyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate and diethylaminoethyl methacrylate, Ether-based monomers; butadiene, isoprene, cyclohexene, acrylonitrile, methacrylonitrile, acrylic acid amide, such as ene-based monomers methacrylamide.

  These may be used alone or in general by appropriately mixing monomers with reference to the theoretical glass transition temperature (Tg) described in the publication Polymer Handbook 2nd edition III-p139 to 192 (manufactured by John Wiley & Sons). Used.

  In the toner of the present invention, it is also preferable that the toner particles contain a polar resin. Furthermore, it is preferable that the glass transition temperature (Tg) measured with the differential scanning calorimetry (DSC) apparatus of the said polar resin is 80 degreeC or more and 120 degrees C or less. By setting Tg within this range, the durability of the toner can be further enhanced. In the toner of the present invention, when Tg is less than 80 ° C., the durability of the toner tends to decrease, and when Tg exceeds 120 ° C., low-temperature fixability tends to decrease.

  The above Tg was measured using a differential scanning calorimeter (DSC measuring device) Q1000 (manufactured by TA Instruments Japan) according to ASTM D3418-82 under the following method and conditions.

<Measurement conditions and method>
(1) Use modulated mode.
(2) Keep the equilibrium at a temperature of 20 ° C. for 5 minutes.
(3) Using a modulation of 1.0 ° C./min, the temperature is increased to 140 ° C. at 1 ° C./min.
(4) Keep the equilibrium at a temperature of 140 ° C. for 5 minutes.
(5) The temperature is lowered to 20 ° C.

  About 3 mg of the measurement sample is accurately weighed. It is put in an aluminum pan, and an empty aluminum pan is used as a control, and measurement is performed at a temperature rising rate of 1 ° C./min between a measurement range of 20 to 140 ° C. The glass transition temperature (Tg) here is determined by the midpoint method.

  When the toner particles used in the present invention are produced by a suspension polymerization method, it is preferable to add a polar resin to the adjustment step. In that case, the presence state of the polar resin can be controlled according to the balance of polarity exhibited by the polymerizable monomer composition serving as toner particles and the aqueous dispersion medium. That is, the added polar resin can form a thin shell on the surface of the toner particles, or can exist with a gradient toward the center from the toner particle surface. In addition, the strength of the shell portion of the core-shell structure can be freely controlled by adding the polar resin. Therefore, it is possible to optimize the durability and fixability of the toner.

  The addition amount of the polar resin is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin. If the amount is less than 1 part by mass, the presence state of the polar resin in the toner particles tends to be uneven, and the triboelectric charge distribution of the toner tends to be broad. On the other hand, when the amount exceeds 30 parts by mass, the thin layer of polar resin formed on the surface of the toner particles becomes thick and the fixability tends to be lowered.

  Specific examples of the polar resin used in the present invention include polyester resins, epoxy resins, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-maleic acid copolymers. In particular, a styrene-methacrylic acid copolymer or a styrene-acrylic acid copolymer having a peak molecular weight of 3,000 or more and 50,000 or less is preferable as a polar resin because the addition amount during toner production can be freely controlled. Further, when a styrene-methacrylic acid copolymer or a styrene-acrylic copolymer is used as the polar resin, it is preferable because the compatibility of the toner with the binder resin is further improved. As a result, the toner particles tend to exist from the surface to the center with an inclination, and the adhesion between the core layer and the shell layer is increased, and the durability of the toner is improved.

As described above, the following points can be cited as preferred embodiments of the toner of the present invention.
-Toner particles have a core-shell structure.
-The adhesion between the core layer and the shell layer is enhanced.
-Toughness against external factors during toner pressurization is high at room temperature.
-The core component (especially wax) has bleeding properties when the toner is heated.

  These characteristics of the toner particles are thought to contribute to development characteristics, transfer characteristics, and fixing characteristics.

  The following are mentioned as a wax component used for this invention.

  Petroleum waxes and derivatives thereof such as paraffin wax, microcrystalline wax, petrolactam; montan wax and derivatives thereof; hydrocarbon waxes and derivatives thereof according to the Fischer-Tropsch method; polyolefin waxes and derivatives thereof such as polyethylene wax and polypropylene wax; Natural waxes such as waxes and candelilla waxes and derivatives thereof; higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid; acid amide waxes; ester waxes; hydrogenated castor oil and derivatives thereof; plant waxes;

  Among these, ester wax and hydrocarbon wax are preferable from the viewpoint of excellent releasability. More preferably, a compound containing 50 to 95% by mass of a compound having the same total number of carbon atoms has high wax purity and easily develops the effects of the present invention from the viewpoint of developability.

  In the present invention, in order to increase the mechanical strength of the toner particles and to control the molecular weight of the toner binder resin, a crosslinking agent may be used when the binder resin is synthesized.

  As the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used. The following aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline And divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These can be used alone or as a mixture. A preferable addition amount is 0.001 to 15 parts by mass with respect to 100 parts by mass of the binder resin.

  In the present invention, it is preferable to use a polymer having a sulfonic acid group in the side chain mainly for charge control and stabilization of granulation in an aqueous medium. Among them, it is particularly preferable to use a polymer or copolymer containing a sulfonic acid group, a sulfonic acid group, or a sulfonic acid ester group.

  Examples of the monomer having a sulfonic acid group for producing the polymer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 2-methacrylamide-2-methylpropane sulfonic acid, vinyl sulfonic acid, methacrylic acid. A sulfonic acid can be illustrated.

  The polymer containing a sulfonic acid group and the like used in the present invention may be a homopolymer of the above monomer, but is a copolymer of the above monomer and another monomer. It doesn't matter. As a monomer that forms a copolymer with the above monomer, there is a vinyl polymerizable monomer, and a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Monofunctional polymerizable monomers include the following styrene: α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn -Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene Styrene-based polymerizable monomers such as 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 Acrylic polymerizable monomers such as polyacrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Mer: 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 Methacrylic polymerizable monomers such as til methacrylate and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid ester; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and vinyl formate; vinyl methyl ether And vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  The following polyfunctional polymerizable monomers include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, Propylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxy-diethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tri Ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Coal dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane 2,2′-bis (4-methacryloxy-polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like.

  The polymer having a sulfonic acid group or the like preferably contains 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer or binder resin. More preferably, it is 0.1 to 3.0 parts by mass.

  In the toner of the present invention, a charge control agent can be mixed with toner particles as necessary. By adding a charge control agent, the charge characteristics can be stabilized, and the optimum triboelectric charge amount can be controlled according to the development system.

  As the charge control agent, known ones can be used, and in particular, a charge control agent that has a high frictional charging speed and can stably maintain a constant triboelectric charge amount is preferable. Further, when the toner is produced by a direct polymerization method, a charge control agent having a low polymerization inhibitory property and substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable.

  Examples of the charge control agent that control the toner to be negatively charged include organometallic compounds and chelate compounds. Examples thereof include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenols. Further examples include urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, and resin charge control agents.

  On the other hand, examples of the charge control agent that control the toner to be positively charged include the following. Nigrosine modified products with nigrosine and fatty acid metal salts; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Some onium salts such as phosphonium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid , Ferricyanides, ferrocyanides); metal salts of higher fatty acids; resin-based charge control agents.

  The toner of the present invention can contain these charge control agents alone or in combination of two or more.

  Among these charge control agents, a salicylic acid-based compound containing a metal is preferable in order to sufficiently exhibit the effects of the present invention, and the metal is particularly preferably aluminum or zirconium. The most preferred charge control agent is an aluminum 3,5-di-tert-butylsalicylate compound.

  A preferable blending amount of the charge control agent is 0.01 parts by mass or more and 20 parts by mass or less, more preferably 0.3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin. However, it is not essential to add a charge control agent to the toner of the present invention, and the toner does not necessarily contain a charge control agent by actively utilizing frictional charging with the toner layer thickness regulating member or the toner carrier. There is no need to let it.

  In the toner of the present invention, inorganic fine powder is externally added as a fluidizing agent.

  The inorganic fine powder externally added to the toner particles of the present invention preferably contains at least silica fine powder. The number average primary particle size of the silica fine powder is preferably 4 nm or more and 80 nm or less. In the present invention, when the number average primary particle size is in the above range, the fluidity of the toner is improved and the storage stability of the toner is also improved.

  The number average primary particle size of the inorganic fine powder is measured as follows.

  The number average primary particle size is observed with a scanning electron microscope, and the particle size of 100 inorganic fine powders in the visual field is measured to determine the average particle size.

  As the inorganic fine powder, silica fine powder and fine powder of titanium oxide, alumina or their double oxide can be used in combination. As the inorganic fine powder used in combination, titanium oxide is preferable.

The silica fine powder includes both dry silica produced by vapor phase oxidation of silicon halide or dry silica called fumed silica, and wet silica produced from water glass. As the silica, dry silica is preferable because it has few silanol groups on the surface and inside of the silica, and few Na ₂ O and SO ₃ ^2- production residues. In addition, dry silica can also be used to produce composite fine powders of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with silicon halogen compounds in the production process. Silica also includes them.

  The inorganic fine powder is added for improving the fluidity of the toner and making the frictional electrification of the toner particles uniform. Hydrophobic treatment of inorganic fine powder can provide functions such as adjustment of triboelectric charge amount of toner, improvement of environmental stability, improvement of characteristics under high humidity environment, etc. It is preferable to use inorganic fine powder. When the inorganic fine powder externally added to the toner particles absorbs moisture, the amount of triboelectric charge as the toner decreases, and the developability and transferability tend to decrease.

  Examples of the treatment agent for the hydrophobic treatment of the inorganic fine powder include the following.

  Unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. These treatment agents may be used alone or in combination.

  Among these, inorganic fine powder treated with silicone oil is preferable. More preferably, the inorganic fine powder is hydrophobized with a coupling agent at the same time or after the treatment, and the hydrophobized inorganic fine powder treated with silicone oil maintains a high triboelectric charge amount of the toner particles even in a high humidity environment. It is good for reducing selective developability.

  In the above production method by suspension polymerization, known inorganic and organic dispersants can be used as the dispersant.

  Specifically, examples of the inorganic dispersant include the following. Tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina Is mentioned.

  On the other hand, examples of the organic dispersant include the following. Polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, carboxymethyl cellulose sodium salt, starch.

  Further, commercially available nonionic, anionic and cationic surfactants can be used as the dispersant. Examples of such surfactants include the following. Sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate.

  As the dispersant, an inorganic poorly water-soluble dispersant is preferable, and it is preferable to use a poorly water-soluble inorganic dispersant that is soluble in an acid.

  In the present invention, when preparing a water-based dispersion medium using a hardly water-soluble inorganic dispersant, the amount of these dispersants used is 0.2 mass relative to 100 parts by mass of the polymerizable monomer. It is preferable that it is at least 2.0 parts by mass. In the present invention, it is preferable to prepare an aqueous dispersion medium using 300 to 3,000 parts by mass of water with respect to 100 parts by mass of the polymerizable monomer composition.

  In the present invention, when preparing an aqueous dispersion medium in which the poorly water-soluble inorganic dispersant as described above is dispersed, a commercially available dispersant may be used as it is. Further, in order to obtain dispersant particles having a fine uniform particle size, the above water-insoluble inorganic dispersant may be produced in a liquid medium such as water under high-speed stirring to prepare an aqueous dispersion medium. For example, when tricalcium phosphate is used as a dispersant, it is possible to form a tricalcium phosphate microparticle by mixing a sodium phosphate aqueous solution and a calcium chloride aqueous solution under high-speed stirring.

  The following are mentioned as a polymerization initiator used for this invention when manufacturing a toner by the said suspension polymerization method.

  2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis Azo or diazo polymerization initiators such as -4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl Peroxide-based polymerization initiators such as peroxide, lauroyl peroxide, tert-butyl-peroxypivalate.

  Although the usage-amount of these polymerization initiators changes with the target degree of polymerization, generally they are 3 mass parts or more and 20 mass parts or less with respect to 100 mass parts of said polymerizable monomers. The kind of the polymerization initiator is slightly different depending on the polymerization method, but is selected with reference to the 10-hour half-life temperature and used alone or in combination.

  Next, an image forming method used in the present invention will be described with reference to FIGS.

  FIG. 18 shows the configuration of an image forming apparatus including the image forming method used in the present embodiment. The image forming apparatus shown in FIG. 19 is a laser beam printer using a transfer type electrophotographic process. In particular, FIG. 19 shows a cross-sectional view of a tandem color LBP (color laser printer).

<Process cartridge>
FIG. 18 is a schematic cross-sectional view of a process cartridge 7 (hereinafter also referred to as “cartridge”) that can be suitably used in an image forming apparatus to which the image forming method of the present invention is applied.

  The cartridge 7 includes a photosensitive drum 1, a cleaner unit 50 having a charging unit 2 and a cleaning unit 6, and a developing unit 4 </ b> A having a developing unit 4 that develops an electrostatic latent image formed on the photosensitive drum 1. Have. The photosensitive drum 1 is rotatably attached to the cleaning frame 31 constituting the cleaner unit 50 via a bearing member (not shown).

  The photosensitive drum 1 has a charging roller 2 for uniformly charging the photosensitive layer provided on the outer peripheral surface of the photosensitive drum 1, and a developer (residual toner) remaining on the photosensitive drum 1 after transfer is removed. The cleaning blade 60 for making contact is in contact. The toner (removed toner) removed from the surface of the photosensitive drum 1 by the cleaning blade 60 is stored in a removed toner storage chamber 35 provided in the cleaning frame 31.

  The developing unit 4A has a developing frame body 45 (45a, 45b, 45e) that accommodates toner, and the developing roller 40 (rotated in the direction of arrow Y) is rotatably attached to the developing frame body 45 via a bearing member. It is supported. Further, a toner supply roller 43 (rotated in the arrow Z direction) and a toner regulating member 44 are provided in contact with the developing roller 40. Further, the developing device frame 45 is provided with a toner transport mechanism 42 for stirring the toner contained therein and transporting the toner to the toner supply roller 43.

  The developing unit 4A is supported so as to be swingable with respect to the cleaner unit 50. That is, the coupling holes 47 and 48 provided at both ends of the developing device frame 45 are aligned with the support holes (not shown) provided at both ends of the cleaning frame 31 of the cleaner unit 50, and pins (not shown) are inserted from both ends of the cleaner unit 50. It is out.

  Further, the developing unit 4A is always urged by a pressure spring (not shown) so that the developing roller 40 contacts the photosensitive drum 1 with the support hole as the rotation axis.

  At the time of development, the toner stored in the toner container 41 is conveyed to the toner supply roller 43 by the toner stirring mechanism 42. The toner supply roller 43 supplies toner to the developing roller 40 by rubbing with the developing roller 40, and causes the toner to adhere on the developing roller 40. The toner adhered on the developing roller 40 reaches the toner regulating member 44 as the developing roller 40 rotates. Then, the toner regulating member 44 regulates the toner to form a predetermined toner thin layer, and gives a desired charge amount. The toner thinned on the developing roller 40 is conveyed to the developing unit in which the photosensitive drum 1 and the developing roller 40 come close as the developing roller 40 rotates. Then, in the developing unit, the latent image is developed by attaching to the electrostatic latent image formed on the surface of the photosensitive drum 1 by a developing bias applied to the developing roller 40 from a power source (not shown). The toner remaining on the surface of the developing roller 40 without contributing to the development of the electrostatic latent image is returned into the developing frame 45 as the developing roller 40 rotates. Then, it is peeled off and collected from the developing roller 40 at the rubbing portion with the toner supply roller 43. The collected toner is stirred and mixed with the remaining toner by the toner stirring mechanism 42.

  Here, an elastic roller is used as the developing roller 40, and a method of bringing the roller into contact with the surface of the photosensitive drum 1 can be used. In general, in a developing method in which a toner carrier and a photoreceptor are in contact with each other, toner is easily damaged or deformed. However, when the toner described in the present invention is used, such a change can be effectively suppressed. preferable.

In the developing method in which the toner carrying member and the photosensitive member are in contact with each other, development is performed by an electric field acting between the photosensitive member and the elastic roller facing the surface of the photosensitive member through the toner. Therefore, the surface of the elastic roller or the vicinity of the surface has a potential, and it is necessary to have an electric field in a narrow gap between the surface of the photoreceptor and the surface of the toner carrying member. Therefore, it is possible to use a method in which the elastic rubber of the elastic roller is resistance-controlled in the middle resistance region to keep the electric field while preventing conduction with the surface of the photoreceptor, or a method of providing a thin insulating layer on the surface layer of the conductive roller. . Further, a conductive resin sleeve in which the side facing the surface of the photoconductor is coated with an insulating material on the conductive roller, or a conductive layer is provided on the side not facing the photoconductor with an insulating sleeve is also possible. . Further, it is possible to employ a configuration in which a rigid roller is used as the toner carrier and the photosensitive member is a flexible material such as a belt. The resistance value of the roller as the toner carrier is preferably in the range of 10 ^{2 to} 10 ⁹ Ω · cm.

  As the surface shape of the toner carrier, when the surface roughness Ra (μm) is set to 0.1 to 3.0, both high image quality and high durability can be achieved. The surface roughness Ra correlates with the toner conveying ability and the toner charging ability. When the surface roughness Ra of the toner carrier exceeds 3.0, it is difficult not only to make the toner layer on the toner carrier thin, but also the chargeability of the toner is not improved, so that improvement in image quality cannot be expected. . Since the toner carrying ability on the surface of the toner carrier is suppressed by setting it to 3.0 or less, the toner layer on the toner carrier is thinned, and the number of contact between the toner carrier and the toner increases. Since the chargeability of the toner is also improved, the image quality is synergistically improved. On the other hand, when the surface roughness Ra is smaller than 0.1, it becomes difficult to control the toner coat amount.

  In the present invention, the surface roughness Ra of the toner carrier is in accordance with Japanese Industrial Standard (JIS) B06014.2.1 (revision date January 20, 2001, confirmation date July 20, 2005). Arithmetic mean roughness determined. In the present invention, a surface roughness measuring device (Surfcoder SE3500 manufactured by Kosaka Laboratory Co., Ltd.) was used to measure from an arbitrary point on the surface of the toner carrier in a direction parallel to the rotation axis of the toner carrier. The cut-off value was 0.8 mm, the measurement length was 2.5 mm, and the measurement speed was 0.1 mm / second.

  In the image forming method of FIG. 18, the toner carrying member rotates in the same direction as the peripheral speed of the photosensitive member, but may rotate in the opposite direction. When the rotation is in the same direction, it is preferable to set the peripheral speed of the toner carrying member to be 1.05 to 3.0 times the peripheral speed of the photosensitive member.

  When the peripheral speed of the toner carrier is less than 1.05 times the peripheral speed of the photoreceptor, the stirring effect received by the toner on the photoreceptor is insufficient, and good image quality cannot be expected. On the other hand, when the peripheral speed ratio exceeds 3.0, toner deterioration due to mechanical stress and toner adhesion to the toner carrier are generated and promoted, which is not preferable.

  When the toner carrier is an elastic roller, a structure having an elastic layer on the surface is preferably used. The hardness of the material of the elastic layer used for the elastic roller is preferably 30 to 60 degrees (ASKER-C / load 1 kg).

  Further, the toner coating amount is controlled by the toner regulating member 44, and the toner regulating member 44 is in contact with the developing roller 40 through the toner layer. At this time, the contact pressure between the toner regulating member 44 and the developing roller 40 is preferably in a range of 0.05 N / cm to 0.5 N / cm as a linear pressure.

  The linear pressure is a load applied per length of the toner regulating member. For example, when a 1.2 N load is applied to the toner regulating member having a contact length of 1 m and brought into contact with the developing roller. The linear pressure is 1.2 N / m. If the linear pressure is less than 0.05 N / cm, it is difficult to control the toner coating amount and uniform triboelectric charging, resulting in fogging. On the other hand, if the linear pressure is higher than 0.5 N / cm, the toner particles are subjected to an excessive load, and therefore, deformation of the particles and adhesion of the toner to the toner regulating member or the developing roller are likely to occur.

  The free end portion of the toner regulating member 44 may have any shape. For example, in addition to a linear cross-sectional shape, an L-shape that is bent near the tip, or a shape that bulges in the vicinity of the tip. Etc. are preferably used.

  As the toner regulating member, a material in which a metal elastic body such as stainless steel, steel, phosphor bronze or the like is used as a base material and a resin is adhered or coated on a portion that contacts the sleeve contact portion is preferably used.

  Furthermore, by applying a DC electric field and / or an AC electric field to the toner regulating member, the uniform thin layer coating property and the uniform charging property are further improved due to the loosening action on the toner, and sufficient image density is achieved. A good quality image can be obtained.

<Image forming apparatus>
FIG. 19 is a schematic cross-sectional view showing an example of an image forming apparatus to which the image forming method of the present invention is applied. The image forming apparatus 100 has four image forming stations Pa, Pb, Pc, and Pd arranged in parallel in the vertical direction. The process cartridges 7 (7a, 7b, 7c, 7d) are detachably attached to the image forming stations Pa, Pb, Pc, Pd by attachment means (not shown). The magenta, cyan, yellow, and black cartridges 7a, 7b, 7c, and 7d have the same configuration.

  In this schematic diagram, the image forming stations Pa, Pb, Pc, and Pd are arranged side by side with a slight inclination in the vertical direction, but they may be arranged in the vertical direction without being inclined. Further, the process cartridge 7 may be the same as that illustrated in FIG. 18 or may be different.

  Each cartridge 7 (7a, 7b, 7c, 7d) includes a photosensitive drum 1 (1a, 1b, 1c, 1d). The photosensitive drum 1 is driven to rotate counterclockwise in the drawing by a driving means (not shown). The following means are provided around the photosensitive drum 1 in order according to the rotation direction. (A) Charging means 2 (2a, 2b, 2c, 2d) for uniformly charging the surface of the photosensitive drum 1. (B) A scanner unit 3 (3a, 3b, 3c, 3d) that irradiates a laser beam based on image information to form an electrostatic latent image on the photosensitive drum 1. (C) Developing means 4 (4a, 4b, 4c, 4d) for developing a toner image by attaching a developer (hereinafter referred to as “toner”) to the electrostatic latent image. (D) A transfer device 5 that transfers the toner image on the photosensitive drum 1 to the recording medium S. (E) Cleaning means 6 (6a, 6b, 6c, 6d) for removing toner remaining on the surface of the photosensitive drum 1 after transfer.

  Here, the photosensitive drum 1 and the charging means 2, the developing means 4, and the cleaning means 6, which are process means, are integrally constituted by a cartridge frame to form a cartridge to constitute a cartridge 7.

  The photosensitive drum 1 (1a, 1b, 1c, 1d) is configured by providing a photosensitive layer on the outer peripheral surface of a cylinder. Both ends of the photosensitive drum 1 are rotatably supported by support members. Then, when a driving force from a driving motor (not shown) is transmitted to one end portion, it is rotationally driven counterclockwise.

As the photoconductor, a photoconductor drum having a photoconductive insulating material layer such as a-Se, CdS, ZnO ₂ , OPC, or a-Si is preferably used. Further, the binder resin of the organic photosensitive layer in the OPC photoreceptor is not particularly limited. Of these, polycarbonate resins, polyester resins, and acrylic resins are particularly preferable because they are excellent in transferability and hardly cause toner fusion to the photoreceptor and filming of external additives.

  As the charging means 2 (2a, 2b, 2c, 2d), a contact charging type is used. The charging means 2 is a conductive roller formed in a roller shape. The roller is brought into contact with the surface of the photosensitive drum 1 and a charging bias voltage is applied to the roller. As a result, the surface of the photosensitive drum 1 is uniformly charged.

  As a preferable process condition when the charging roller is used, the contact pressure of the roller is 0.05 to 5 N / cm as a linear pressure. As the applied voltage, a DC voltage or a DC voltage superimposed with an AC voltage is preferably used. When a DC voltage superimposed with an AC voltage is used, it is preferable that AC voltage = 0.5 to 5 dVpp, AC frequency = 50 Hz to 5 kHz, and DC voltage = ± 0.2 to ± 1.5 kV. When a DC voltage is used, the DC voltage is preferably ± 0.2 to ± 5 kV.

  As charging means other than the charging roller, there are a method using a charging blade and a method using a conductive brush. These contact charging means have an effect that a high voltage is unnecessary and generation of ozone is reduced as compared with non-contact corona charging. The material of the charging roller and charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and the like are applicable.

  In the scanner unit 3 (3a, 3b, 3c, 3d), a laser diode (not shown) passes image light corresponding to an image signal through a polygon mirror (not shown) and an imaging lens (not shown) rotated at high speed. Then, the surface of the charged photosensitive drum 1 is exposed according to image information. As a result, an electrostatic latent image is formed on the photosensitive drum.

  The developing means 4 (4a, 4b, 4c, 4d) is composed of a toner container 41 that stores magenta, cyan, yellow, and black toners, respectively, and feeds toner in the toner container 41. To the toner supply roller 43.

  The toner supply roller 43 rotates in the clockwise direction in the figure, and supplies toner to the developing roller 40 as a toner carrying member and does not contribute to the development of the electrostatic latent image. Perform stripping.

    The toner supplied to the developing roller 40 is applied to the outer periphery of the developing roller 40 (rotated clockwise) by the toner regulating member 44 pressed against the outer periphery of the developing roller 40, and is given an electric charge. Then, a developing bias is applied to the developing roller 40 facing the photosensitive drum 1 on which the latent image is formed. Then, toner development is performed on the photosensitive drum 1 in accordance with the latent image.

  The transfer device 5 is provided with an electrostatic transfer belt 11 that circulates and moves so as to face and contact all the photosensitive drums 1 (1a, 1b, 1c, 1d). The transfer belt 11 is stretched around a driving roller 13, driven rollers 14a and 14b, and a tension roller 15, and electrostatically attracts the recording medium S to the outer peripheral surface on the left side in the drawing. The transfer belt 11 circulates so that the recording medium S is brought into contact with the photosensitive drum 1. As a result, the recording medium S is conveyed to the transfer position by the transfer belt 11 and the toner image on the photosensitive drum 1 is transferred.

  The transfer roller 12 (12a, 12b, 12c, 12d) is arranged in parallel at a position in contact with the inside of the transfer belt 11 and facing the four photosensitive drums 1 (1a, 1b, 1c, 1d). A bias is applied to the transfer rollers 12 at the time of transfer, and an electric charge is applied to the recording medium S via the electrostatic transfer belt 11. The toner image on the photosensitive drum 1 is transferred to the recording medium S in contact with the photosensitive drum 1 by the electric field generated at this time.

  The feeding unit 16 feeds and transports the recording medium S to the image forming stations Pa, Pb, Pc, and Pd. A plurality of recording media S are stored in the cassette 17 in the feeding unit 16. At the time of image formation, the feeding roller 18 (half-moon roller) and the registration roller 19 are driven and rotated according to the image forming operation. The feeding roller 18 separates and feeds the recording medium S in the cassette 17 one by one, and then stops the recording medium S by abutting against the registration roller 19. Thereafter, the registration roller 19 feeds the recording medium S to the electrostatic transfer belt 11 in synchronization with the rotation of the transfer belt 11 and the image writing position.

  The fixing unit 20 fixes the toner images of a plurality of colors transferred to the recording medium S. The fixing unit 20 includes a heating roller 21a and a pressure roller 21b that presses against the heating roller 21a and applies heat and pressure to the recording medium S. That is, the recording medium S to which the toner image formed on the photosensitive drum 1 has been transferred is conveyed by the pressure roller 21b and applied with heat and pressure by the heating roller 21a when passing through the fixing unit 20. As a result, a plurality of color toner images are fixed on the surface of the recording medium S.

  As an image forming operation, the cartridges 7 (7a, 7b, 7c, 7d) are sequentially driven in accordance with the image forming timing. In response to the driving, the photosensitive drums 1a, 1b, 1c, and 1d are rotationally driven in the counterclockwise direction. Then, the scanner units 3 corresponding to the respective cartridges 7 are sequentially driven. By this driving, the charging roller 2 applies a uniform charge to the peripheral surface of the photosensitive drum 1. The scanner unit 3 exposes the circumferential surface of the photosensitive drum in accordance with the image signal to form an electrostatic latent image on the circumferential surface of the photosensitive drum. The developing roller 40 in the developing unit 4 forms (develops) a toner image on the circumferential surface of the photosensitive drum 1 by transferring the toner to the low potential portion of the electrostatic latent image.

  At the timing when the leading edge of the toner image formed on the circumferential surface of the most upstream photosensitive drum 1 is rotated and conveyed to the point facing the transfer belt 11, the print start position of the recording medium S coincides with the point facing the transfer belt 11. Thus, the registration roller 19 rotates to feed the recording medium S to the transfer belt 11.

  The recording medium S is pressed against the outer periphery of the transfer belt 11 so as to be sandwiched between the suction roller 22 and the transfer belt 11. A voltage is applied between the transfer belt 11 and the suction roller 22. Electric charges are induced in the recording medium S that is a dielectric and the dielectric layer of the transfer belt 11, and the recording medium S is electrostatically adsorbed on the outer periphery of the transfer belt 11. Thereby, the recording medium S is stably adsorbed to the electrostatic transfer belt 11 and conveyed to the most downstream transfer unit.

  While being conveyed in this manner, the toner image on each photosensitive drum 1 is sequentially transferred to the recording medium S by an electric field formed between each photosensitive drum 1 and the transfer roller 12.

  The recording medium S to which the four color toner images are transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt driving roller 13 and is carried into the fixing unit 20. After the toner image is heat-fixed by the fixing unit 20, the recording medium S is discharged out of the main body by the paper discharge roller 23 with the image surface facing down from the paper discharge unit 24.

  The present invention will be specifically described with reference to the following examples. However, this does not limit the present invention in any way. A method for producing yellow toner particles will be described below. Unless otherwise specified, all parts and% in the examples and comparative examples are based on mass.

<Example 1>
To 900 parts of ion-exchanged water heated to 60 ° C., 9 parts of tricalcium phosphate and 11 parts of 10% hydrochloric acid are added and stirred at 10,000 rpm using a TK homomixer (manufactured by Special Machine Industries). An aqueous medium having a pH of 5.2 was prepared.

Further, the following materials were uniformly dissolved and mixed at 100 r / min with a propeller stirrer to prepare a resin-containing monomer.
Styrene 13.5 parts n-butyl acrylate 28.0 parts Polar resin 1: Styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer (copolymerization ratio = 80.85: 2.50: 1.65: 15 0.0, Mp = 19,700, Mw = 7,900, Tg = 96 ° C., acid value = 12.0 mgKOH / g, Mw / Mn = 2.1)
20.0 parts

In addition, the following formulation was dispersed with an attritor to obtain a colorant-containing monomer.
-Styrene 58.5 parts-C.I. I. Pigment Yellow 74 6.5 parts, charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 1.0 part, sulfonic acid group-containing polymer (FCA1001NS (manufactured by Fujikura Kasei)) 1.0 part

Next, after the colorant-containing monomer and the resin pigment monomer are mixed to obtain an adjustment liquid, the adjustment liquid is heated to 60 ° C., and a hydrocarbon wax (melting point 77 ° C.) HNP-51, manufactured by Nippon Seiwa Co., Ltd.): 8 parts were added. Next, an ultrasonic oscillator as shown in FIG. 3 was introduced into the adjustment liquid, and dispersion / mixing was performed while irradiating ultrasonic waves from the ultrasonic irradiation unit into the adjustment liquid for 2 hours. When oscillating ultrasonic waves, the ultrasonic output A is set to 4.8 kW and the A / B is set to 60.0 W / cm ² where the ultrasonic output is A and the ultrasonic irradiation area is B. Further, when the colorant-containing polymerizable monomer composition to be ultrasonically treated is C (kg) and the total output of the ultrasonic generator is D (kW), C / D is set to 58 kg / kW and dispersed. -Mixing was performed.

  In this, 8.0 parts of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition. The polymerizable monomer composition was put into the aqueous medium and stirred at 60 ° C. using a TK homomixer at 10,000 r / min for 30 minutes for granulation.

  Thereafter, the mixture was transferred to a propeller type stirring device and reacted at 70 ° C. for 5 hours while stirring at 100 r / min, then heated to 80 ° C. and further reacted for 5 hours to produce toner particles. After completion of the polymerization reaction, the slurry containing the particles was cooled to room temperature (25 ° C.), and hydrochloric acid was added to the suspension to dissolve the calcium phosphate salt, followed by filtration and washing to obtain wet colored particles.

  Next, the particles were dried at a temperature of 40 ° C. for 12 hours to obtain colored particles, and the colored particles were classified by wind classification to obtain toner particles 1.

100 parts of the above toner particles and 2.0 parts of hydrophobic silica fine powder having a BET value of 150 m ² / g as an external additive and a primary particle size of 10 nm are mixed with a Henschel mixer (Mitsui Miike Chemical Co., Ltd.). As a result, yellow toner (A) was obtained. Table 1 shows the physical properties of the yellow toner (A).

<Example 2>
In Example 1, a styrene-methacrylic acid-methyl methacrylate-butyl acrylate copolymer (styrene / methacrylic acid / methyl methacrylate / butyl acrylate = 83.85 / 2.50 / 1. A yellow toner (B) was obtained in the same manner except that 20.0 parts of 65 / 12.00) were added. Table 1 shows the physical properties of the yellow toner (B).

<Example 3>
In Example 1, when the resin-containing monomer was prepared, the yellow toner was prepared in the same manner except that the addition amount of styrene was changed to 18.5 parts and the addition amount of n-butyl acrylate was changed to 23.0 parts. (C) was obtained. Table 1 shows the physical properties of the yellow toner (C).

<Example 4>
A yellow toner (D) was obtained in the same manner as in Example 1 except that 5.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added. Table 1 shows the physical properties of the yellow toner (D).

<Example 5>
In Example 1, a yellow toner (with the same method except that 25.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added and the ultrasonic irradiation time was changed to 2.5 hours) E) was obtained. Table 1 shows the physical properties of the yellow toner (E).

<Example 6>
In Example 5, an ultrasonic output A is set to 2.8 kW, A / B is set to 35.0 W / cm ² , C / D is set to 100 kg / kW, and irradiation is performed for 2 hours. A yellow toner (F) was obtained in the same manner except that was prepared. Table 1 shows the physical properties of the yellow toner (F).

<Example 7>
In Example 6, a yellow toner (G) was obtained by the same method except that the colorant-containing polymerizable monomer composition was prepared by irradiating with ultrasonic waves for 1 hour. Table 1 shows the physical properties of the yellow toner (G).

<Example 8>
In Example 5, an ultrasonic output A is set to 5.2 kW, A / B is set to 65.0 W / cm ² , C / D is set to 54 kg / kW, and irradiation is performed for 3 hours. A yellow toner (H) was obtained by the same method except that was prepared. Table 1 shows the physical properties of the yellow toner (H).

<Example 9>
A yellow toner (I) was obtained in the same manner as in Example 6 except that the colorant-containing polymerizable monomer composition was prepared by irradiating with ultrasonic waves for 0.5 hour. Table 1 shows the physical properties of the yellow toner (I).

<Example 10>
In Example 7, a yellow toner (J) was obtained in the same manner except that 5.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added. Table 1 shows the physical properties of the yellow toner (J).

<Example 11>
A yellow toner (K) was obtained in the same manner as in Example 7 except that 25.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added. Table 1 shows the physical properties of the yellow toner (K).

<Example 12>
A yellow toner (L) was obtained in the same manner as in Example 8, except that 20.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added. Table 1 shows the physical properties of Toner (L).

<Example 13>
In Example 1, the ultrasonic oscillator shown in FIG. 6 was introduced into the preparation process, the ultrasonic output A was set to 5.6 kW, A / B to 330.0 W / cm ² , and C / D to 50 kg / kW. A yellow toner (M) was obtained in the same manner except that a colorant-containing polymerizable monomer composition was prepared by irradiation for 2 hours. Table 1 shows the physical properties of the yellow toner (M).

<Example 14>
In Example 1, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 30 m / s, and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (N) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (N).

<Example 15>
In Example 2, the stirring device shown in FIG. 11 was introduced in the preparation process instead of the ultrasonic oscillator, and the peripheral speed E of the stirring blade 1 was set to 30 m / s, and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (O) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (O).

<Example 16>
In Example 3, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 30 m / s, and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (P) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (P).

<Example 17>
In Example 4, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 30 m / s, and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (Q) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (Q).

<Example 18>
In Example 5, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, and the peripheral speed E of the stirring blade 1 was set to 30 m / s and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (R) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 3 hours. Table 1 shows the physical properties of the yellow toner (R).

<Example 19>
In Example 6, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, and the peripheral speed E of the stirring blade 1 was set to 20 m / s and the peripheral speed F of the screen 2 was set to 20 m / s. A yellow toner (S) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (S).

<Example 20>
In Example 7, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 20 m / s, and the peripheral speed F of the screen 2 was set to 20 m / s. A yellow toner (T) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 1 hour. Table 1 shows the physical properties of the yellow toner (T).

<Example 21>
In Example 8, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 60 m / s, and the peripheral speed F of the screen 2 was set to 60 m / s. A yellow toner (U) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 1 hour. Table 1 shows the physical properties of the yellow toner (U).

<Example 22>
In Example 9, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 15 m / s, and the peripheral speed F of the screen 2 was set to 15 m / s. A yellow toner (V) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (V).

<Example 23>
In Example 10, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillation device in the preparation process, the peripheral speed E of the stirring blade 1 was set to 20 m / s, and the peripheral speed F of the screen 2 was set to 20 m / s. A yellow toner (W) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 1 hour. Table 1 shows the physical properties of the yellow toner (W).

<Example 24>
In Example 11, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillator in the preparation step, and the peripheral speed E of the stirring blade 1 was set to 20 m / s and the peripheral speed F of the screen 2 was set to 20 m / s. A yellow toner (X) was obtained by the same method except that the colorant-containing polymerizable monomer composition was prepared by operating for 1 hour. Table 1 shows the physical properties of the yellow toner (X).

<Example 25>
In Example 12, the stirring device shown in FIG. 11 was introduced instead of the ultrasonic oscillator in the preparation process, and the peripheral speed E of the stirring blade 1 was set to 60 m / s and the peripheral speed F of the screen 2 was set to 60 m / s. A yellow toner (Y) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 1 hour. Table 1 shows the physical properties of the yellow toner (Y).

<Example 26>
In Example 13, the stirring device shown in FIG. 9 was introduced instead of the ultrasonic oscillator in the preparation process, and the peripheral speed E of the stirring blade 1 was set to 30 m / s and the peripheral speed F of the screen 2 was set to 30 m / s. A yellow toner (Z) was obtained in the same manner except that the colorant-containing polymerizable monomer composition was prepared by operating for 2 hours. Table 1 shows the physical properties of the yellow toner (Z).

<Example 27>
In Example 1, the mixing apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillator in the preparation process, the circumferential speed G of the rotor was set to 32 m / s, and the system was operated for 2 hours. A yellow toner (AA) was obtained by the same method except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AA).

<Example 28>
In Example 2, the mixing apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillator in the preparation process, and the peripheral speed G of the rotor was set to 32 m / s, and the system was operated for 2 hours. A yellow toner (AB) was obtained by the same method except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AB).

<Example 29>
In Example 3, the dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, the peripheral speed G of the rotor was set to 32 m / s, and the system was operated for 2 hours. A yellow toner (AC) was obtained by the same method except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AC).

<Example 30>
In Example 4, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, the rotor peripheral speed G was set to 32 m / s, and the operation was performed for 2 hours. A yellow toner (AD) was obtained in the same manner except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AD).

<Example 31>
In Example 5, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, the peripheral speed G of the rotor was set to 60 m / s, and the operation was performed for 1 hour. A yellow toner (AE) was obtained by the same method except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AE).

<Example 32>
In Example 6, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, and the peripheral speed G of the rotor was set to 32 m / s, and the system was operated for 1 hour. A yellow toner (AF) was obtained by the same method except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AF).

<Example 33>
In Example 7, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, and the peripheral speed G of the rotor was set to 32 m / s, and the system was operated for 0.5 hours to perform colorant-containing polymerization. A yellow toner (AG) was obtained in the same manner except that the photosensitive monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AG).

<Example 34>
In Example 8, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation step, the peripheral speed G of the rotor was set to 60 m / s, and the operation was performed for 2 hours. A yellow toner (AH) was obtained in the same manner except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AH).

<Example 35>
In Example 9, in the preparation process, the dispersing device shown in FIG. 12 was introduced instead of the ultrasonic oscillator, and the peripheral speed G of the rotor was set to 20 m / s, and the operation was performed for 2 hours. A yellow toner (AI) was obtained in the same manner except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AI).

<Example 36>
In Example 10, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, the peripheral speed G of the rotor was set to 32 m / s, and the operation was performed for 0.5 hour to perform colorant-containing polymerization. A yellow toner (AJ) was obtained by the same method except that the photosensitive monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AJ).

<Example 37>
In Example 11, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation process, and the peripheral speed G of the rotor was set to 32 m / s, and the operation was performed for 0.5 hour to perform colorant-containing polymerization. A yellow toner (AK) was obtained by the same method except that a functional monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AK).

<Example 38>
In Example 12, a dispersion apparatus shown in FIG. 12 was introduced instead of the ultrasonic oscillation apparatus in the preparation step, the peripheral speed G of the rotor was set to 60 m / s, and the operation was performed for 2 hours. A yellow toner (AL) was obtained in the same manner except that the monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (AL).

<Example 39>
In Example 1, it was the same except that the colorant-containing polymerizable monomer composition was obtained using CLEA SS5 manufactured by M Technique Co., Ltd. shown in FIGS. 20 to 22 instead of the ultrasonic oscillator in the adjustment step. Thus, yellow toner (AM) was obtained. Table 1 shows the physical properties of yellow toner (AM).

  FIG. 20 is a partial cross-sectional view of the dispersing apparatus used in Example 39. 21 is a schematic cross-sectional view of a main part of the disperser or mixer shown in FIG. The disperser or mixer includes a first holder 11, a second holder 21 disposed in front of (above) the first holder 11, a case 3 that covers the first holder 11 together with the second holder 21, and a mixed liquid or an object to be manufactured. A supply mechanism P such as a pump for supplying the granular liquid to the apparatus and a contact surface pressure applying mechanism 4 are provided. The first holder 11 is provided with a first processing ring 10 and a rotation shaft 50. The first processing ring 10 (mating ring) is a metal annular body (shown in FIG. 22), and has a first processing surface 1 that is mirror-finished. The rotary shaft 50 is fixed to a fixing tool 51 such as a bolt at the center of the first holder 11, and an end thereof is connected to a rotary drive device 5 (rotary drive mechanism) such as an electric motor. The force is transmitted to the first holder 11 to rotate the first holder 11. The first processing ring 10 is attached to the front (upper part) of the first holder 11 concentrically with the rotation shaft 50, and rotates integrally with the first holder 11 by the rotation of the rotation shaft 50. The first processing surface 1 is exposed from the first holder 11 and faces the second holder 21 side. The case 3 is a bottomed container having a discharge part 32, and the first holder 11 is accommodated in the internal space 30.

  The second holder 21 is provided with a second processing ring 20, a mixed liquid or granulated liquid introducing portion 22, and a contact pressure applying mechanism 4. The second processing ring 20 (compression ring) is a metal annular body, is fixed, is mirror-finished second processing surface 2, and is positioned inside the second processing surface 2, and the second processing surface 2. A pressure receiving surface 23 (hereinafter referred to as a separation adjusting surface 23) adjacent to the surface 2 is provided. As shown in the figure, the separation adjusting surface 23 is formed as an inclined surface. The mirror surface processing applied to the second processing surface 2 employs the same method as that for the first processing surface 1. In addition, the same material as that of the first processing ring 10 is used for the material of the second processing ring 20. The separation adjusting surface 23 is adjacent to the inner peripheral surface of the annular second processing ring 20.

  The contact surface pressure applying mechanism 4 presses the second processing surface 2 against the first processing surface 1 in a pressure contact state or close proximity, and fluid pressure (pressure on the mixed liquid generated by a supply mechanism such as a pump). ), A thin fluid film is generated by the balance with the force that separates the processing surfaces 1 and 2 from each other. In other words, the thin fluid film keeps the distance between the processing surfaces 1 and 2 at a very small distance.

  Specifically, in this embodiment, the contact surface pressure applying mechanism 4 includes an accommodating portion 41, a spring receiving portion 42 provided on the deepest portion of the accommodating portion 41, a spring 43, and an air introducing portion 44. It is composed of.

  The housing part 41 is provided with the second processing ring 20 so that the position of the second processing ring 20 in the housing part 41 can be displaced deeply or shallowly (up and down). One end of the spring 43 is in contact with the back of the spring receiving portion 42, and the other end of the spring 43 is in contact with the front portion (upper portion) of the second processing ring 20 in the housing portion 42.

  In FIG. 20, as described above, a pressurized gas such as pressurized air is introduced from the air introduction portion 44 into the housing portion 41. By introducing such a pressurized gas such as air, a pressure chamber can be provided between the accommodating portion 41 and the second processing ring 20 and air pressure can be applied to the second processing ring 20 as a pressing force together with the spring 43. .

  The contact surface pressure imparting mechanism 4 supplies and adjusts a part of the pressing force (contact surface pressure), and also serves as a displacement adjustment mechanism and a buffer mechanism. Specifically, the contact surface pressure applying mechanism 4 is a displacement adjusting mechanism, and can follow the axial displacement due to the elongation or wear in the axial direction during starting or during operation by adjusting the air pressure, and can maintain the initial pressing force. Further, as described above, the contact surface pressure applying mechanism 4 also functions as a buffer mechanism for fine vibration and rotational alignment by adopting a floating mechanism that holds the second processing ring 20 in a displaceable manner.

  Further, even if there is a margin between the upper portion of the second processing ring 20 and the uppermost portion of the housing portion 41 in the housing portion 41, the contact surface pressure applying mechanism 4 has the spring 43 and the first processing surface 1. 2 The upper limit of the width of the gap between the processing surface 2 is defined. The contact surface pressure imparting mechanism 4 functions as a separation inhibiting unit that inhibits separation exceeding the regulation of the first processing surface 1 and the second processing surface 2.

  Even if the first processing surface 1 and the second processing surface 2 are not in contact with each other, the spring 43 defines the lower limit of the width of the gap between the first processing surface 1 and the second processing surface 2. It functions as a proximity deterring unit that deters the proximity of the first processing surface 1 and the second processing surface 2 that is less than the specified range.

  Using this dispersing / mixing device, the rotation speed of the first processing ring is set to 8000 rpm, and 600 kPa of compressed air is introduced into the air introduction portion 44 to thereby provide a surface between the first processing ring 10 and the second processing ring 20. After adjusting the pressure, the prepared solution was introduced into the disperser through the introduction unit 22 using a pump, and mixed for 2 hours.

<Comparative example 1>
In Example 1, a yellow toner (a) was obtained by the same method except that the resin-containing monomer was prepared without using an ultrasonic oscillator in the preparation step. Table 1 shows the physical properties of the yellow toner (a).

<Comparative example 2>
In Example 1, 10.0 parts of styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added, and a colorant-containing polymerizable monomer composition was used without using an ultrasonic oscillator in the preparation process. A yellow toner (b) was obtained by the same method except that was prepared. Table 1 shows the physical properties of the yellow toner (b).

<Comparative Example 3>
In Example 1, 1.0 part of divinylbenzene was added, and a yellow toner (c) was prepared in the same manner except that a colorant-containing polymerizable monomer composition was prepared without using an ultrasonic oscillator in the preparation process. ) Table 1 shows the physical properties of the yellow toner (c).

<Comparative example 4>
In Example 1, when the resin-containing monomer was prepared, the addition amount of styrene was changed to 25.5 parts and the addition amount of n-butyl acrylate was changed to 16.0 parts without using an ultrasonic oscillator. A yellow toner (d) was obtained by the same method except that the colorant-containing polymerizable monomer composition was prepared. Table 1 shows the physical properties of the yellow toner (d).

<Comparative Example 5>
In Example 1, 5.0 parts by mass of a styrene-methacrylic acid-methyl methacrylate-α-methylstyrene copolymer was added, and a colorant-containing polymerizable monomer composition was used without using an ultrasonic oscillator in the preparation process. A yellow toner (e) was obtained by the same method except that the product was prepared. Table 1 shows the physical properties of the yellow toner (e).

  The evaluation method and evaluation criteria of the present invention will be described below.

  As the image forming apparatus, a modified machine of LBP-5400 (manufactured by Canon), which is a commercially available laser printer, was used.

The remodeling points of the evaluation machine are as follows.
(1) The process speed was set to 190 mm / sec by changing the gear and software of the evaluation machine main body.

  The cartridge used for the evaluation was a yellow cartridge. That is, the product toner was extracted from a commercially available yellow cartridge, the inside was cleaned by air blow, and then the toner according to the present invention was filled for evaluation. In addition, the product toner was extracted from each of the magenta, cyan, and black stations, and evaluation was performed by inserting magenta, cyan, and black cartridges in which the toner remaining amount detection mechanism was disabled.

<Evaluation for developability>
In a modified machine of LBP-5400 (manufactured by Canon Inc.), the developer is filled with 200 g of the toner described in the examples and comparative examples and placed in a high temperature and high humidity (temperature 30.0 ° C., humidity 85% RH) environment. Leave for 24 hours. At this time, the transfer paper is also left as it is. Xerox 4200 (manufactured by Xerox Co., Ltd.) (75 g / m ² paper) was used as the transfer paper. Thereafter, in a high temperature and high humidity (temperature 30.0 ° C., humidity 85% RH) environment, up to 10000 images of 1% printing ratio in intermittent mode (every 10 seconds for each printing, the developer is paused, The image was printed out in a mode that promotes the deterioration of the toner by the preliminary operation of the developing device at the time of restart. At that time, image evaluation was performed on the following items after initial, after endurance after 5,000 sheets and after endurance at 10,000 sheets.

(Image density)
The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth) to measure a relative density with respect to an image of a white background portion having a document density of 0.00. The following criteria A, B and C are levels that do not cause problems in use, while D is a level that causes problems in use.
A: 1.40 or more B: 1.30 or more and less than 1.40 C: 1.20 or more and less than 1.30 D: 1.10 or more and less than 1.20

(Fog)
The fog evaluation method outputs an image having a white background portion, and the whiteness (reflectance Ds (%)) of the white background portion of the printout image measured by “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku) and the transfer paper The fog density (%) (= Dr (%) − Ds (%)) was calculated from the difference in whiteness (average reflectance Dr (%)), and the image fog at the end of the durability evaluation was evaluated. A blue light filter was used as the filter. The following criteria A, B and C are levels that do not cause problems in use, while D is a level that causes problems in use.
A: Less than 0.5% B: 0.5% or more and less than 1.0% C: 1.0% or more and less than 1.5% D: 1.5% or more and less than 5.0%

(Transferability)
The evaluation of transferability was performed by measuring the transfer efficiency after the initial and after 5000 sheets and after the initial and after 10,000 sheets. The transfer efficiency is determined by tapering the transfer residual toner on the photoconductor after the solid black image transfer with a Mylar tape and pasting it on the paper. The Macbeth density value is C, and the Mylar is applied on the paper with the toner after the fixing before the transfer. The Macbeth density of the tape with the tape applied was E, and the Macbeth density of the Mylar tape affixed on the unused paper was D, and approximately calculated by the following formula.

The transfer efficiency was determined based on the transfer efficiency determined above based on the following criteria.
A: Very good (over 97%)
B: Good (94 to less than 97%)
C: Practical use possible (90 to less than 94%)
D: Not practical (less than 90%)

  If the transfer efficiency is 90% or more, there is no problem.

(Charge uniformity)
The charging uniformity was evaluated as follows. The particle size distribution of the toner in the cartridge after the initial and after 5000 sheets and after the initial and 10,000 sheets is measured in accordance with the above-mentioned measuring method of the weight average particle diameter (D4), and from each of the obtained weight average particle diameters (D4). The particle size change rate was calculated based on the following formula and evaluated based on the following criteria.
Initial weight average particle diameter (D4) / weight average particle diameter (D4) after 5000 sheets (or after 10,000 sheets) × 100 = change rate of particle size (%)
A: 95 ≦ particle size change rate (%) ≦ 100
B: 85 ≦ particle size change rate (%) <95
C: 75 ≦ particle size change rate (%) <85
D: Particle size change rate (%) <75

  A is the best and D is the worst.

(Rising rise)
The toner charge rise was judged by the following criteria based on the density change (measured with a Macbeth reflection densitometer) of the solid patch images from the first sheet to the 20th sheet of the print.
A: Number of sheets up to density 1.4 is 5 or less B: Number of sheets up to density 1.4 is 6 to 10 sheets C: Number of sheets up to density 1.4 is 11 to 20 sheets D: Density More than 21 sheets up to 1.4 (component contamination)
The member contamination was evaluated based on the following criteria by visually observing the state of toner and external additives adhering to the surface of the developer carrying member and the effect on the obtained image.
A: Not generated (no sticking)
B: Although sticking occurs slightly, the influence on the image is small. C: Sticking occurs, and image unevenness is slightly caused by this, but there are few problems in practical use.
D: There is a large amount of fixation, resulting in image unevenness. There are also practical problems.

(Contamination of the main body and cartridge due to toner scattering)
In order to evaluate the balance between chargeability and fluidity of the toner, the degree of contamination by toner around the cartridge and the cartridge in the main body was observed.
A: No contamination by toner around the cartridge and the cartridge in the main body is observed.
B: Contamination due to a small amount of toner is observed on the cartridge.
C: Stain due to toner around the cartridge and the cartridge in the main body is observed, but does not affect the attachment / detachment of the image / cartridge.
D: The area around the cartridge and the cartridge in the main body is markedly contaminated with toner, and the image / cartridge attachment / detachment is also adversely affected.

[Evaluation Tests 1 to 39 and Comparative Evaluation Tests 1 to 5]
Table 2 shows the results of the above evaluation for the yellow toners (A) to (AM) and the yellow toners (a) to (e).

Claims (8)

A yellow toner having toner particles and inorganic fine powder containing at least a binder resin, a release agent, a polar resin and a colorant,
As the colorant, C.I. I. Pigment Yellow 74,
In a minute compression test for the yellow toner, when a maximum load of 2.94 × 10 ⁻⁴ N is applied to the toner at a measurement temperature of 25 ° C. and a load speed of 9.8 × 10 ⁻⁵ N / sec. The displacement amount (μm) obtained in the above step is the displacement amount X ₁ , and after the maximum load is applied, the displacement amount (μm) obtained by leaving for 0.1 second at the maximum load is the maximum displacement amount X ₂ . After leaving for 1 second, unloading is performed at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement (μm) obtained when the load becomes 0 is expressed as displacement X ₃ , the maximum displacement X ₂ and the elastic displacement of the difference between the displacement X ₃ (X ₂ -X ₃₎ and then, the elastic displacement (X ₂ -X ₃₎ the maximum displacement X percentage of ₂ [{(X ₂ -X ₃ of ) / X _2} × 100: when the recovery ratio] was Z (25) (%), Z (25) is 80% or less 40% Satisfy the relationship,
A yellow toner characterized in that when the dielectric loss tangent tan δ at a temperature of 30 ° C. measured at a frequency of 100 kHz in the toner is α, α satisfies 0.0010 or more and 0.0030 or less.   2. The yellow toner according to claim 1, wherein β satisfies 0.0010 or more and 0.0040 or less, where β is a dielectric loss tangent tan δ measured at a frequency of 100 kHz at a temperature of 60 ° C. of the yellow toner. In the micro-compression test for the yellow toner, when a maximum load of 2.94 × 10 ⁻⁴ N was applied to one particle of the toner at a measurement temperature of 50 ° C. at a load speed of 9.8 × 10 ⁻⁵ N / sec. The displacement amount (μm) obtained is the displacement amount X ′ ₁ , and after the maximum load is applied, the displacement amount (μm) obtained by leaving the maximum load for 0.1 second is the maximum displacement amount X ′ ₂ . After leaving for 0.1 second, unloading is performed at an unloading speed of 9.8 × 10 ⁻⁵ N / sec, and the displacement amount (μm) obtained when the load becomes 0 is expressed as the displacement amount X ′ ₃ , the maximum displacement The difference between the amount X ′ ₂ and the displacement amount X ′ ₃ is defined as the elastic displacement amount (X ′ ₂ −X ′ ₃ ), and the elastic displacement amount (X ′ ₂ −X ′ ₃ ) with respect to the maximum displacement amount X ′ ₂ . percentages: when the _{[{(X '2 -X'} 3) / X '2} × 100 recovery ratio] was Z (50) (%), Z (50) is 55% more than 10% less The yellow toner according to claim 1 or 2, characterized by satisfying the relation.   Dispersing step of dispersing at least a colorant in a polymerizable monomer to obtain a colorant-containing monomer, dissolving step of obtaining a resin-containing monomer by dissolving at least a resin in the polymerizable monomer, and containing the obtained colorant A toner having at least a preparation step of mixing a monomer and a resin-containing monomer to obtain a preparation liquid, and a granulating step of dispersing the preparation liquid in an aqueous dispersion to produce particles of a polymerizable monomer composition A toner obtained by a method for producing particles, wherein the preparation step comprises mixing the colorant-containing monomer and the resin-containing monomer with an ultrasonic generator to obtain a preparation liquid. The yellow toner according to claim 1, comprising toner particles obtained by the method.   The ultrasonic generator has a vibrator for irradiating ultrasonic waves having convex portions in the circumferential direction of a cylinder, and the convex portions are convex portions that form concentric circles with respect to the cylinder, 5. The toner particles according to claim 4, comprising toner particles obtained by a production method characterized in that a preparation liquid is obtained by mixing the colorant-containing monomer and the resin-containing monomer by vibrating the vibrator. Yellow toner.   The preparation step is a step of mixing the colorant-containing monomer and the resin-containing monomer with a stirrer having a high-speed shearing force in the liquid, and the stirrer is a stirrer that rotates at high speed and the A stirring chamber formed by a screen that rotates at a high speed in the opposite direction to the stirring blade is provided around the stirring blade, and the prepared liquid is ejected from the stirring chamber. 4. The yellow toner according to claim 1, comprising toner particles obtained by a production method comprising mixing a monomer and the resin-containing monomer to obtain a preparation liquid. 5.   The stirrer is provided in a container, and the preparation liquid is repeatedly introduced and discharged through the container, and mixed for a predetermined time, whereby the colorant-containing monomer and the resin-containing monomer are mixed. The yellow toner according to claim 6, comprising toner particles obtained by a production method characterized in that a preparation liquid is obtained by mixing the toner.   In the preparation step, a stator having the same shape as a rotor in which ring-shaped protrusions having a plurality of slits are formed in multiple stages on concentric circles are arranged on the same axis so as to mesh with each other while maintaining a constant interval. It is obtained by a production method characterized in that the adjustment liquid is repeatedly introduced and discharged in a mixing apparatus and circulated, and the colorant-containing monomer and the resin-containing monomer are mixed to obtain a preparation liquid. The yellow toner according to claim 1, comprising toner particles.

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