JP2011039110A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which, even when improved low-temperature fixing performance is achieved, has good heat-resistant preservability and durable stability, excels in hot offset resistance and infiltration resistance, and enables a high-quality image to be formed. <P>SOLUTION: The toner includes: toner particles comprising at least a binder resin, a colorant and a release agent; and an inorganic fine powder. The toner has a peak Ta(°C) at 35.0-60.0°C, a peak Tb(°C) at 65.0-90.0°C and a peak Tc(°C) at 95.0-135.0°C in a temperature (x-axis)-G'10/G'1 (y-axis) curve formed by plotting a ratio (G'10/G'1) of a storage modulus (G'10) at a frequency of 10 Hz to a storage modulus (G'1) at a frequency of 1 Hz as the y-axis and a temperature (°C) at which the storage moduli are measured as the x-axis. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner used for developing an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, magnetic recording, or toner jet recording.

  When the low-temperature fixing performance of the toner is improved, the performance (heat resistant storage performance) of preventing a so-called blocking phenomenon in which agglomeration occurs between toners in contact with each other in a high-temperature environment to form a lump is easily deteriorated. Furthermore, since the performance (durability and stability performance) that suppresses the occurrence of image defects in a large amount of continuous printing tends to be reduced, a toner that satisfies these performances simultaneously is desired. In the fixing process, when the surface temperature of the heat roller or the fixing film is high, a high temperature offset phenomenon that occurs due to excessive softening and melting of the uppermost toner layer among the toner layers on the fixing sheet. Suppressing performance (high temperature resistant offset performance) tends to decrease. Furthermore, the performance (smudge resistance) that suppresses the occurrence of unevenness in the gloss of the image tends to decrease.

  Various toners having a core-shell structure have been proposed with the aim of achieving both low-temperature fixing performance and heat-resistant storage performance. That is, the core particle surface containing at least a colorant and a release agent and containing a binder resin having a low glass transition temperature (Tg) as a main component is coated with a resin having a high Tg, whereby low-temperature fixing performance and heat-resistant storage are achieved. The aim is to achieve both performances (see Patent Document 1). Further, a toner has been proposed that aims to have good low-temperature fixing performance, heat-resistant storage performance and durability stability performance by forming a coating layer of resin fine particles (see Patent Documents 2 and 3). On the other hand, as a rheological property of the binder resin contained in the toner, the dynamic viscoelasticity of the toner is measured at a temperature of Tg + 35 ° C. of the binder resin, and the ratio value of the storage elastic modulus G ′ measured at different frequencies is obtained. There has been proposed a toner aiming at achieving both low-temperature fixing performance and stability in continuous printing by controlling. However, it is difficult for these toners to satisfy the other performances described above when further improving the low-temperature fixing performance.

JP 2008-58620 A JP 2008-9385 A JP 2004-226572 A JP 2007-225917 A

  An object of the present invention is to provide a toner that solves the above-mentioned problems when improving low-temperature fixing performance, has good heat-resistant storage stability and durability stability performance, and is excellent in high-temperature offset resistance performance and penetration resistance performance. It is.

  The present invention is a toner comprising toner particles having a coating layer formed by fixing resin fine particles to core particles containing at least a binder resin, a colorant, and a release agent, and inorganic fine powder. The measurement temperature (° C.) in the x-axis direction and the ratio (G′10 / G ′) of the storage elastic modulus (G′1) at a frequency of 1 Hz and the storage elastic modulus (G′10) at a frequency of 10 Hz in the y-axis direction. The temperature-G′10 / G′1 curve created by plotting 1) has a peak Ta at 35.0 to 60.0 ° C. and a peak Tb at 65.0 to 90.0 ° C. And a toner having a peak Tc at 95.0 to 135.0 ° C.

  According to the present invention, even when the low temperature fixing performance is improved, it has good heat storage stability and durability stability performance, is excellent in high temperature offset resistance and penetration resistance, and enables formation of high quality images. Toner can be provided.

It is an example of the temperature-G'10 / G'1 curve of the toner of the present invention determined by a dynamic viscoelasticity test. It is a conceptual diagram which shows the surface shape of the serrated parallel plate used for a dynamic viscoelasticity measurement. FIG. 3 is a conceptual diagram showing a positional relationship when toner pellets are set in a dynamic viscoelasticity measuring apparatus.

The method for measuring dynamic viscoelasticity in the present invention is described below. As a measurement sample, a sample formed by pressure molding using a tablet molding machine in an environment of a temperature of 25 ° C. and a humidity of 60% RH is used. When the true density of the toner is ρ (g / cm ³ ), the toner is weighed 0.20 × ρ (g), a 20 kN load is applied for 2 minutes, and a cylindrical pellet having a diameter of 8 mm and a thickness of 4 mm is formed. To do. The following measurements are performed using this pellet. As a measuring device, for example, ARES (Rheometric Scientific F.E. Co., Ltd.) can be used. Specific measurement conditions are shown below.
-Array (Geometry Type): Parallel Plates (Parallel Plates)
・ Parallel plate: Serrated type parallel plate is used ・ Measurement start temperature (Initial Temp): described later (TgT-10 (° C.))
-Measurement end temperature (Final Temp): 180 (° C)
-Gap adjustment (Change Gap to Match Tool Thermal Expansion): on
・ Expansion coefficient (Tool Thermal Expansion Coefficient): 0.0 (μm / ° C.)
-Density (Fluid Density): 1.0 (g / cm ³ )
-Apparatus compliance: 0.83 (μrad / g · cm)
Test mode: Dynamic Temperature Ramp
・ Frequency
1 Hz: 6.2832 (rad · s)
10 Hz: 62.832 (rad · s)
・ Ramp rate: 2.0 (° C / min)
・ Soak Time After Ramp: 1.0 (s)
Measurement interval (Time Per Measurement): 30.0 (s)
-Strain: 0.02 (%)
-Tension adjustment (Auto Tension Adjustment): on
-Mode: Apply Constant Static Force
・ Tension direction (AutoTension Direction): Compression
-Initial static force (Initial Static Force): 10.0 (g)
・ Auto Tension Sensitivity: 40.0 (g)
-Automatic tension operating conditions (When Sample Modulus <): 1.00e + 08 (dyn / cm ² )
・ Auto Tension Limit (AutoTension Limits): Default
・ Maximum automatic tension rate: 0.01 (mm / s)
-Automatic distortion adjustment (AutoStrain): on
Maximum strain (Max Applied Strain): 40.0 (%)
Maximum torque (Max Allowed Torque): 150.0 (g · cm)
・ Minimum Torque: 1.0 (g · cm)
-Strain adjustment: 20.0 (%)
-Strain width adjustment (Default Amplitude Control): Default Behavior
・ Option (Measurement Option): Default Delay Settings
Cycles: 0.5
Time: 3.0 (s)
-Transducer (Transducer): Transducer 1

  FIG. 2 is a conceptual diagram of the surface shape of a serrated parallel plate used for measuring the dynamic viscoelasticity of toner in the present invention. FIG. 3 is a conceptual diagram showing the positional relationship when the toner pellets are set in the dynamic viscoelasticity measuring apparatus.

  The sample chamber of the measuring apparatus is held at 25.0 ° C. in advance, the pellet is set so that the load (Axial Force) is 30, and the hold switch is turned on. The hold switch has a function of holding the load applied to the pellet at the value of the load when the switch is turned on by adjusting the distance (Gap) between the plates sandwiching the pellet. When the glass transition point of the toner measured by a differential scanning calorimeter (DSC) described later is TgT (° C.), the temperature of the sample chamber is heated to TgT + 2 (° C.). When the sample chamber is stabilized at the temperature, the hold switch is removed, the distance between the plates is adjusted so that the load applied to the pellet (Axial Force) is 1500, and the hold switch is turned on again. Then, since the convex portion of the serrated plate is gradually embedded in the surface of the pellet due to the load, the distance between the plates gradually decreases. When the hold switch is turned on as the load 1500, the hold switch is removed when the distance between the plates becomes 10% smaller than the distance between the plates. Further, the distance between the plates is increased so that the load applied to the pellet is 150. At this time, care should be taken to move the plate slowly and gradually. Also, the load should not be less than 150. When the load reaches 150, the hold switch is turned on again, and the temperature of the sample chamber is set to the measurement start temperature. The measurement start temperature is the TgT-10 (° C.). When the measurement start temperature is reached and the sample chamber temperature is stabilized, the hold switch is removed and the distance between the plates at that time is input. Then, measurement is started.

  In the above measurement, the purpose of fixing the pellets at a temperature of TgT + 2 (° C.) is to prevent the toner from being overheated. As a result, the presence state of the binder resin, wax and other additives contained in the toner can be suppressed from being changed by heat before the measurement is started, and the physical properties of the toner can be measured more accurately. .

  The measurement is performed twice using two pellets, when the measurement frequency is 1 Hz and when the measurement frequency is 10 Hz. The storage elastic modulus obtained when the measurement frequency is 1 Hz is G′1 (Pa), and the storage elastic modulus obtained when the measurement frequency is 10 Hz is G′10 (Pa). A temperature-G′1 curve in which each measured temperature is taken on the x-axis, a value of G′1 at that time is taken on the y-axis, and a temperature −G′10 in which the value of G′10 is taken on the y-axis. Get a curve. Further, the ratio of G′1 and G′10 (G′10 / G′1) is taken on the y axis, and the average value of the measured temperature at the frequency of 1 Hz and the measured temperature at the frequency of 10 Hz is taken on the x axis, A temperature-G′10 / G′1 curve is created.

  The storage elastic modulus obtained by the above measurement is an index often used to express the thermal physical properties of the toner. The present inventors have examined the storage elastic modulus of the toner and found the following. In the toner temperature-storage modulus curve obtained by dynamic viscoelasticity measurement, behavior due to the thermal characteristics of the toner appears. Further, in the high temperature region of the temperature-G′10 curve obtained by measuring the dynamic viscoelasticity of the toner at 10 Hz, the temperature-G′1 curve measured at 1 Hz which is a standard frequency in dynamic viscoelasticity measurement. May show characteristic behavior that is not seen. In particular, the more the toner having a so-called core-shell structure and a uniform coating state by the coating layer, the more the above behavior appears in the high temperature region of the temperature-G′10 curve. Furthermore, the measurement temperature (° C.) in the x-axis direction and the ratio (G′10 / G ′) of the storage elastic modulus (G′1) at a frequency of 1 Hz and the storage elastic modulus (G′10) at a frequency of 10 Hz in the y-axis direction. In the temperature-G′10 / G′1 curve created by plotting 1), the characteristics of the toner as described above can be clearly expressed.

  The present inventors have examined the temperature-G′10 / G′1 curve. As a result, the curve has three peaks, and each peak exists within a predetermined temperature range. The present inventors have found that it is important for achieving both high-quality images with excellent low-temperature fixing performance, heat-resistant storage performance, and durability stability performance. Specifically, the toner temperature-G′10 / G′1 curve has a peak Ta at a temperature of 35.0 to 60.0 ° C. and a peak Tb at a temperature of 65.0 to 90.0 ° C. When the temperature is 95.0 to 135.0 ° C. and has a peak Tc, the above-mentioned object can be achieved.

  Here, the peak Ta refers to a point that appears on the lowest temperature side in the temperature-G′10 / G′1 curve and the slope of the curve turns from positive to negative. The peak Tb is a point where the slope of the curve turns from negative to positive, which appears on the high temperature side next to the bottom Td in the temperature-G′10 / G′1 curve. The peak Tc refers to a point that appears on the high temperature side next to the bottom Te in the temperature-G′10 / G′1 curve, and the slope of the curve turns from negative to positive. In the present invention, there is no particular limitation on whether or not there is a peak at a temperature higher than the peak Tc.

  In dynamic viscoelasticity measurements, there is a correlation between temperature and frequency. When dynamic viscoelasticity measurement of a general toner manufactured by a pulverization method or a polymerization method is performed, the temperature-G′1 curve and the temperature-G′10 curve have almost the same shape, and the temperature-G′10. The curve is a state in which the temperature-G′1 curve is parallel shifted to the high temperature side by about 5 ° C. When a temperature-G′10 / G′1 curve is created for such a toner, a peak corresponding to the peak Tb appearing at 65.0 to 90.0 ° C. does not appear in the present invention. On the other hand, when the temperature-G′1 curve and the temperature-G′10 curve are compared, the toner of the present invention has a characteristic that the shape of the curve is different in a relatively high temperature region as described above. That is, the value of G′10 is particularly large compared to G′1 in a specific temperature range, and thereby a characteristic peak Tb is detected in the temperature-G′10 / G′1 curve.

  In order to satisfy the storage elastic modulus characteristic defined in the present invention, it is considered that at least the toner needs to have a thermodynamically hard portion and a soft portion. However, the temperature-G′10 / G′1 curve defined by the present invention cannot be obtained simply by their presence in the toner. For example, when dynamic viscoelasticity measurement of a toner prepared by mixing a resin a having a certain glass transition point (Tg) and a resin b having a Tg higher than that of the resin a is performed, the Tg of the resin a and the resin Only a behavioral change corresponding to Tg between b and Tg is detected. Therefore, in the temperature-G′10 / G′1 curve, a behavior change corresponding to Tg of the resin a or the resin b is not detected, and only one peak is observed.

  On the other hand, in a toner such as a core-shell structure in which the resin a and the resin b are separated in phase, the dynamic viscoelasticity measurement corresponds to the Tg of the resin a regardless of whether the frequency is 1 Hz or 10 Hz. A behavior and a behavior corresponding to the Tg of the resin b are detected. However, for example, when the resin a is not sufficiently coated with the resin a, the peak Tb is assimilated with the peak Tc in the temperature-G′10 / G′1 curve, and only two peaks are observed.

  The toner particles of the present invention have a so-called core-shell structure having core particles and a coating layer covering the core particles. Furthermore, it is preferable that the coating layer is formed by fixing resin fine particles to the core particles. The reason why the toner of the present invention has the above storage elastic modulus characteristics is considered as follows.

  The toner particles of the present invention have a uniform coating state with the shell phase in a state where a part of the core phase and the shell phase (coating layer) are compatible or in a sufficiently close contact state. Furthermore, there is a difference in the thermal hardness of the core phase and the shell phase and the softening point of the toner as a whole. When having such a configuration, physical properties of the core phase and the shell phase are detected in the dynamic viscoelasticity measurement at a frequency of 1 Hz. On the other hand, under high frequency measurement conditions such as a frequency of 10 Hz, there is a significant difference between the hardness of the shell phase and the entire softened state of the toner particles in a specific temperature range. Thereby, in addition to the physical properties of the core phase and the shell phase, it is possible to detect the physical properties of the entire toner particles derived from the softening point of the toner, which are difficult to detect at a frequency of 1 Hz.

  From the above, in the temperature-G′10 / G′1 curve of the toner of the present invention, the thermal hardness of the core phase and the shell phase appears favorably, so that two peaks appear. It is considered that the third peak appears because of the difference between the target hardness and the softening point of the toner as a whole. As will be described below, the presence of these three peaks indicates that the core phase, the shell phase, and the entire toner particles exhibit the required thermal characteristics.

  The toner in the present invention has a peak Ta at a temperature of 35.0 to 60.0 ° C. This peak Ta corresponds to the thermal hardness of the core phase. If the value of Ta is within the above range, the core phase is sufficiently soft and the low-temperature fixability is high. If Ta is less than 35.0 ° C., the heat resistant storage performance and durability stability performance will be reduced. On the other hand, when Ta exceeds 60.0 ° C., low temperature offset is likely to occur, and the low temperature fixing performance is deteriorated. Ta mainly depends on the glass transition point of the core particles of the toner. In addition to this, it is comprehensively controlled by the material constituting the toner, the presence state of the material, and the manufacturing conditions.

  The toner in the present invention has a peak Tb at a temperature of 65.0 to 90.0 ° C. The peak Tb is derived from the thermal hardness of the shell phase, and if Tb is within the above range, the thermal hardness of the shell phase is suitably expressed, so that the durability stability and heat resistant storage stability are improved. . If Tb is less than 65.0 ° C., the heat-resistant storage performance and the durability stability performance deteriorate. On the other hand, if Tb exceeds 90.0 ° C., peeling of the fixed image is likely to occur, and the low-temperature fixing performance is deteriorated. Tb can be controlled by the glass transition point, the coating amount, and the coating state of the resin forming the shell phase.

  Further, the toner in the present invention has a peak Tc at a temperature of 95.0 to 135.0 ° C. The peak Tc corresponds to the softened state of the entire toner particle. If Tc is within the above range, the toner can be prevented from being excessively soft in the temperature range applied to the toner in the fixing step, so that the high-temperature offset resistance performance, penetration resistance performance and durability stability performance are improved. When Tc is less than 95.0 ° C., the high-temperature offset resistance performance, the penetration resistance performance, and the durability stability performance deteriorate. When Tc exceeds 135.0 ° C., the low-temperature fixing performance deteriorates. Tc can be controlled by the resin used for the toner, the melting point of the release agent, and the toner production conditions.

  When the thermal hardness of the core phase and the shell phase is close, the peak Ta and the peak Tb are assimilated, and the number of peaks becomes two. Further, when the thermal hardness of the shell phase is close to the softening point of the whole toner, the peak Tb and the peak Tc are assimilated, and the number of peaks is also two. In addition, if the amount of the coating layer is uneven in each toner particle, or if the coating state by the coating layer is uneven, the physical property behavior corresponding to the shell phase will not be detected, and this A peak corresponding to the peak Tb of the invention does not appear.

  The toner of the present invention has a bottom Td between the Ta and the Tb in the temperature-G′10 / G′1 curve, and the value of G′10 / G′1 at the Tb (G′b). And the difference (G′b−G′d) between G′10 / G′1 (G′d) in Td is preferably 1.00 to 5.00. G′b-G′d is considered to indicate the phase separation state of the core phase and the shell phase. If the value of G′b−G′d is within the above range, the core phase and the shell phase are appropriately compatible, and the heat resistant storage performance is high and low temperature offset hardly occurs.

  The toner of the present invention has a bottom Te between the Tb and the Tc in the temperature-G′10 / G′1 curve, and the G′b and the G′10 / G′1 in the Te The difference (G′b−G′e) from the value (G′e) is preferably 0.20 to 4.00. G′b-G′e is considered to indicate variations in the coating state of the coating layer in the toner particles and the amount of the coating layer contained in the toner. If the value of G′b−G′e is within the above range, the content of the coating layer is less uneven in each toner particle, the coating state by the coating layer becomes sufficiently thin and uniform, and heat resistant storage The low-temperature fixing performance is improved while maintaining the properties.

  The toner of the present invention preferably has a maximum value (Mp) at a molecular weight of 4000 to 18000 in a molecular weight distribution in terms of polystyrene by gel permeation chromatography (GPC) of a THF soluble component. Further, in the molecular weight distribution in terms of polystyrene by GPC, the weight average molecular weight (Mw) is preferably 10,000 to 150,000. When the values of Mp and Mw are within the above ranges, the low-temperature fixing performance and the permeation resistance performance are further improved while maintaining the durability stability performance of the toner. The preferable range of Mp is 8000 to 16000, and the preferable range of Mw is 35000 to 130,000.

  The toner of the present invention preferably contains 5.0 to 30.0% by mass of a THF-insoluble component obtained by a Soxhlet extraction method. When the content of the THF-insoluble component is within the above range, the low-temperature fixing performance and the high-temperature offset resistance performance are further improved while maintaining the durability stability performance of the toner.

  In the toner of the present invention, the glass transition point (Tg1) of the core particles is preferably 25.0 to 55.0 ° C. Moreover, when forming a coating layer with resin fine particles, it is preferable that the glass transition point (Tg2) of resin fine particles is 55.0 or more and 90.0 degrees C or less. Moreover, it is preferable that the difference (Tg2-Tg1) between the glass transition point (Tg1) of the core particles and the glass transition point (Tg2) of the resin fine particles is 10.0 to 40.0 ° C. When Tg2, Tg1, and Tg2-Tg1 are within the above ranges, the durability and heat-resistant storage performance are improved without impairing the low-temperature fixing performance.

  In order to satisfy the storage elastic modulus defined by the present invention, the toner particles of the present invention comprise a core containing at least a binder resin, a colorant, and a release agent in an aqueous medium having a sparingly water-soluble inorganic dispersant. Forming a dispersion having particles, adding the resin fine particles to the dispersion to form a composite dispersion, heating the composite dispersion, and the poorly water-soluble inorganic in the composite dispersion. It is preferably formed through a step of dissolving the dispersant. This will be specifically described below.

  First, the core particle obtained by the method etc. which are mentioned later is added to the aqueous medium which has an inorganic dispersing agent, and a dispersion liquid is created. In this step, by using a poorly water-soluble inorganic dispersant, the surface of the core particles can be uniformly coated with the inorganic dispersant, and the inorganic dispersant can be uniformly adhered between the core particles. . As the inorganic dispersion stabilizer, it is preferable to use a material such as tricalcium phosphate having a polarity that is significantly different from that of the core particle. At this time, the zeta potential (Zc) of the dispersion of core particles is -15.0 mV or less (negatively large), and (Zs + 10.0) to (Zs + 50.0) mV in relation to Zs described later. Preferably there is.

  After the surfaces of the core particles are coated with an inorganic dispersant, resin fine particles are added to the core particle dispersion to form a composite dispersion. When the resin fine particles are added, the adsorption force works due to the interaction between the inorganic dispersant and the resin fine particles. Thereby, it is considered that the resin fine particles can be uniformly adhered to the surface of the core particles using the inorganic dispersant as a medium, and the content of the resin fine particles can be made uniform between the core particles.

  Here, the zeta potential (Zs) of the resin fine particle dispersion is preferably −110 or more and −50 mV or less. The value of Zs is considered to be derived from the type and content of acidic groups possessed by the resin fine particles and the particle diameter of the resin fine particles. When Zs is within the above range, the adhesion between the core particles and the resin fine particles of the toner becomes better, and the coating state of the resin fine particles covering the core particles becomes more uniform.

  After forming a state in which the resin fine particles are uniformly adhered to the core particles, the core particles and the resin fine particles are softened by heating the composite dispersion containing these core particles and the resin fine particles. In this step, the temperature of the composite dispersion is preferably maintained at Tg1 or more and Tg2 or less.

  Furthermore, the process of melt | dissolving the inorganic dispersing agent on the core particle surface is performed. By dissolving the inorganic dispersant, the resin fine particles are fixed to the surface of the core particles, and the content of the resin fine particles and the coating state can be made uniform between the core particles. Here, the term “fixed” refers to a state in which the resin fine particles do not easily peel off or fall off from the core particle surface.

  As a method for dissolving the inorganic dispersant, it is preferable to perform an acid treatment step of adjusting the pH of the dispersion by adding hydrochloric acid. By dissolving an inorganic dispersant such as a poorly water-soluble inorganic salt in the acid treatment step, the resin fine particles can be uniformly fixed to all the core particles in the dispersion. Therefore, the development stability performance of the toner is further improved.

  The concentration of hydrochloric acid is preferably 0.1 to 0.5 mol / l. As a result, the coating layer formed on each toner particle tends to be uniform among the toner particles. Moreover, in the said acid treatment process, in order to keep the state of the resin fine particles adhering to the core particles uniform, it is preferable to slowly add hydrochloric acid. A suitable addition rate is 0.05 parts by mass / min to 2.00 parts by mass / min with respect to 100 parts by mass of the solid content of the core particle dispersion. As a result, the coating layer formed on each toner particle tends to be uniform between the toners.

  In the acid treatment step, the acid treatment step is performed while heating at a temperature not higher than the Tg2 (° C) and higher by 5.0 ° C to 50.0 ° C than the Tg1 (° C). Is preferable from the viewpoint of the durability and stability of the toner.

  After the acid treatment step, it is preferable to have a second heating step of adjusting the pH of the dispersion to a pH region where the poorly water-soluble inorganic dispersant is reprecipitated and then heat-treating at a temperature of Tg2 or higher. By adjusting the pH and reprecipitating the inorganic dispersant, the surface of the particles to which the resin fine particles are fixed is coated with the inorganic dispersant, so that aggregation of the particles is suppressed even when heated above the Tg of the resin fine particles. be able to. As a result, the coating layer of the resin fine particles is smoothed, and becomes a more uniform and dense layer.

  In the toner of the present invention, the coating amount of the coating layer formed from the resin fine particles is preferably 1.0 to 15.0% by mass with respect to the core particles. When the coating amount is within the above range, a dense coating layer can be formed without deteriorating the toner fixing property.

  The weight average particle diameter (D4) of the toner is preferably 4.0 to 8.0 μm. If the weight average particle diameter of the toner particles is within the above range, the resin fine particles are appropriately fixed to the core particles, and the resin fine particles can be prevented from peeling off or embedded in the core particles.

  As a method for producing the resin fine particles used in the present invention, there is a phase inversion emulsification method. In the phase inversion emulsification method, a resin having self-water dispersibility or a resin capable of expressing self-water dispersibility by neutralization is used. Here, the resin having self-water dispersibility is a resin containing a functional group capable of self-dispersion in an aqueous medium in the molecule, specifically, a resin containing an acidic group or a salt thereof. . Further, a resin that can exhibit self-water dispersibility by neutralization is a resin that contains an acidic group in a molecule that has increased hydrophilicity by neutralization and can be self-dispersed in an aqueous medium. When these resins are dissolved in an organic solvent, a neutralizing agent is added as necessary, and mixed with an aqueous medium while stirring, the resin solution undergoes phase inversion emulsification and fine particles are generated. The organic solvent is removed using a method such as heating or decompression after phase inversion emulsification. As described above, according to the phase inversion emulsification method, a stable aqueous dispersion of resin fine particles can be obtained by the action of an acidic group substantially without using an emulsifier or a dispersion stabilizer.

  The material of the resin fine particles may be any material that can be used as a binder resin for toner, and resins such as vinyl resins, polyester resins, epoxy resins, and urethane resins are used. Of these, polyester resins are preferred because they have sharp melt properties and therefore do not obstruct the low-temperature fixability of the core particles.

  The average particle diameter of the resin fine particles is preferably 10 to 300 nm as a median diameter (D50) determined by particle size distribution measurement by a laser scattering method. More preferably, it is 30 to 200 nm. If D50 of the resin fine particles is within the above range, it is possible to obtain a sufficient fixing strength to the core particles while preventing the resin fine particles from being embedded in the core particles. The median diameter is a particle diameter defined as a 50% value (central cumulative value) of a cumulative curve of particle size distribution. For example, a laser diffraction / scattering particle size distribution measuring apparatus (LA-) manufactured by HORIBA, Ltd. 920). The weight average molecular weight (Mw) of the resin fine particles is preferably 5000 to 25000 from the viewpoint of achieving both low-temperature fixing performance, blocking resistance performance, durability stability performance, offset resistance performance, and penetration resistance performance of the toner.

  The core particles are polymerized by adding a polymerizable monomer composition containing at least a polymerizable monomer, a colorant and a release agent to an aqueous medium, and granulating the polymerizable monomer composition in the aqueous medium. It is preferably obtained by forming particles of the polymerizable monomer composition and polymerizing the polymerizable monomer contained in the particles of the polymerizable monomer composition. Specifically, first, at least a colorant and a release agent are added to the polymerizable monomer that is the main constituent material of the core particle, and a disperser such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic disperser is used. A polymerizable monomer composition in which these are uniformly dissolved or dispersed is prepared. At this time, additives such as a polyfunctional monomer, a chain transfer agent, a charge control agent, and a plasticizer can be appropriately added to the polymerizable monomer composition as necessary. Next, the polymerizable monomer composition is put into an aqueous medium containing a dispersion stabilizer prepared in advance, and suspended using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser. Granulate.

  The polymerization initiator may be mixed with other additives when preparing the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition just before being suspended in the aqueous medium. Good. Moreover, it can also add in the state melt | dissolved in the polymerizable monomer and other solvent as needed just before starting a polymerization reaction. In the polymerization reaction, the granulated suspension is heated to a temperature of 50 ° C. or more and 90 ° C. or less, the particles of the polymerizable monomer composition in the suspension maintain the particle state, and the particles float or settle. Is carried out with stirring so as not to occur.

  By repeating the addition reaction with the polymerization initiator in a chain manner, the polymerization reaction proceeds, and core particles whose main constituent material is the binder resin derived from the polymerizable monomer are formed. Distillation may be performed in the latter half of the polymerization reaction or after the completion of the polymerization reaction. By performing the distillation step, the remaining unreacted polymerizable monomer can be removed.

  The following are mentioned as a polymerizable monomer which can be used for manufacture of a core particle. Styrene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and other styrenic monomers; methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic Acrylic acid esters such as isobutyl acid, n-propyl acrylate; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate; acrylonitrile, methacrylate Ronitrile, acrylamide. Among these polymerizable monomers, it is preferable to use a mixture of styrene or a styrene-based monomer and another polymerizable monomer from the viewpoint of developing characteristics and durability of the toner. The mixing ratio of these polymerizable monomers is appropriately selected in consideration of the desired glass transition point of the core particles.

  As the polymerization initiator used in the production of the core particles, known peroxide polymerization initiators and azo polymerization initiators can be used, but peroxide polymerization initiators have little residue of decomposition products. Is preferred. Two or more polymerization initiators can be used simultaneously as required. In this case, the preferred amount of the polymerization initiator used is 0.1 to 20 parts by mass with respect to 100 parts by mass of the monomer. Examples of peroxide polymerization initiators include the following. t-butyl peroxylaurate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, etc. Peroxyester polymerization initiator; di-n-propyl peroxydicarbonate, di-n-butyl peroxydicarbonate, di-n-pentyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butylper Peroxydicarbonate-based polymerization initiators such as oxydicarbonate; diisobutyryl peroxide, diisononanoyl peroxide, di-n-octanoyl peroxide, dilauroyl peroxide, distearoyl peroxide, dibenzoyl peroxide , J-m Diacyl peroxide polymerization initiators such as toluoyl peroxide and benzoyl-m-toluoyl peroxide; t-hexylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl mono Peroxymonocarbonate polymerization initiators such as carbonate and t-butylperoxyallylmonocarbonate; 1,1-di-t-hexylperoxycyclohexane, 1,1-di-t-butylperoxy-3,3 Peroxyketal polymerization initiators such as 5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di-t-butylperoxybutane; dicumyl peroxide, di-t-butyl Peroxide, t-butyl Dialkyl peroxide-based polymerization initiators such as mill peroxide.

  In the production of the core particles, a chain transfer agent can be used for the purpose of adjusting the molecular weight. Examples of the chain transfer agent include the following. alkyl mercaptans such as n-pentyl mercaptan, isopentyl mercaptan, 2-methylbutyl mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan; alkyl esters of thioglycolic acid; alkyl esters of mercaptopropionic acid Halogenated hydrocarbons such as chloroform, carbon tetrachloride, ethylene bromide, carbon tetrabromide; α-methylstyrene dimer. These chain transfer agents are not necessarily used, but a preferable addition amount when used is 0.05 to 3 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the production of the core particles, a small amount of a polyfunctional monomer can be used in combination for the purpose of improving high temperature offset resistance. As the polyfunctional monomer, a compound having two or more polymerizable double bonds is mainly used. 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, divinyl ether and divinyl Divinyl compounds such as sulfide and divinyl sulfone; compounds having three or more vinyl groups. These polyfunctional monomers are not necessarily used, but a preferable addition amount when used is 0.01 to 1 part by mass with respect to 100 parts by mass of the polymerizable monomer.

  In the production of the core particles, as the dispersion stabilizer added to the aqueous medium, known surfactants, organic dispersants, and inorganic dispersants can be used. Among these, inorganic dispersants can be suitably used because they are less likely to produce ultrafine powder, are less likely to lose stability even when the polymerization temperature is changed, are easily washed, and do not adversely affect the toner. Examples of such inorganic dispersants include the following. Polyvalent metal phosphates such as tricalcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate; carbonates such as calcium carbonate and magnesium carbonate; inorganic salts such as calcium metasuccinate, calcium sulfate and barium sulfate; Inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite and alumina. When these inorganic dispersants are used, they may be used as they are in an aqueous medium, but in order to obtain finer particles, they are prepared and used in an aqueous medium using a compound capable of generating inorganic dispersant particles. You can also For example, in the case of tricalcium phosphate, sodium phosphate aqueous solution and calcium chloride aqueous solution can be mixed under high speed stirring to produce water-insoluble tricalcium phosphate, which enables more uniform and fine dispersion. Become. These inorganic dispersants can be almost completely removed by adding an acid or an alkali after the polymerization and dissolving. These inorganic dispersants are desirably used alone in an amount of 0.2 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. A surfactant of 1 part by mass or less may be used in combination. Examples of the surfactant include the following. Sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate.

  Moreover, you may superpose | polymerize by adding a polyester resin in the polymerizable monomer composition mentioned above. The polyester resin is a resin having a relatively high polarity including many ester bonds. When this polyester resin is dissolved in the polymerizable monomer composition and polymerized, the resin tends to move to the surface layer of the droplets in the aqueous medium, and is unevenly distributed on the surface of the particle as the polymerization proceeds. Therefore, the granulation property is improved. Moreover, the above-described release agent can be easily included. As said polyester resin, what polycondensated the polyhydric alcohol component and the polyhydric carboxylic acid component by the well-known method can be used.

  The addition amount of the polyester resin is preferably in the range of 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. Moreover, you may add the hybrid resin which has a polyester unit and a vinyl-type copolymer unit instead of a polyester resin.

  Specific examples of the monomer for producing a polyester resin that can be used for the production of resin fine particles and core particles include the following compounds.

  As the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane , Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxy) Phenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane-like alkylene oxide adducts such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1 , 3-propylene glycol, 1,4-butanediol, neopentylglycol 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, Hydrogenated bisphenol A, following formula (VII)

(In the formula, R represents an ethylene or propylene group, x and y each represents an integer of 1 or more, and the average value of x + y represents 2 or more and 10 or less.)
Or a bisphenol derivative represented by the following formula (VIII)

The compound shown by these is mentioned.

  Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1 , 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene. .

  As the polyvalent carboxylic acid component, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof; alkyl dicarboxylic acids such as oxalic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; Succinic acid substituted with 6 to 12 alkyl groups or anhydrides thereof; Unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof; n-dodecenyl succinic acid, isododecenyl succinic acid, tri A merit acid is mentioned.

  Among them, in particular, a bisphenol derivative represented by the general formula (VIII) and an alkyl diol having 2 to 6 carbon atoms as a diol component, a divalent carboxylic acid or an acid anhydride thereof, or a lower alkyl thereof. Carboxylic acid components comprising esters (for example, fumaric acid, maleic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, alkyl dicarboxylic acids having 4 to 10 carbon atoms, and acids of these compounds Polyester obtained by polycondensing these with an acid anhydride as an acid component is preferable as a color toner because it has good charging characteristics.

  Examples of the method for producing the polyester include an oxidation reaction synthesis method, synthesis from a carboxylic acid and its derivatives, an ester group introduction reaction represented by a reaction with Michael, and a dehydration condensation reaction from a carboxylic acid compound and an alcohol compound. Examples of the method used include a reaction from an acid halide and an alcohol compound, and a transesterification reaction. The catalyst may be a general acidic or alkaline catalyst used in the esterification reaction, such as zinc acetate or a titanium compound. Thereafter, it may be highly purified by a production method such as a recrystallization method or a distillation method.

  Examples of the release agent used in the toner of the present invention include the following. Petroleum wax such as paraffin wax, microcrystalline wax, petrolatum and derivatives thereof; montan wax and derivatives thereof; hydrocarbon wax and derivatives thereof according to Fischer-Tropsch method; polyolefin wax and derivatives thereof typified by polyethylene; carnauba wax and candelilla Natural waxes such as waxes and derivatives thereof. Derivatives include block copolymers with oxides and vinyl monomers, and graft modified products. Furthermore, higher fatty alcohols, fatty acids such as stearic acid and palmitic acid, or compounds thereof, acid amide waxes, ester waxes, ketones, hydrogenated castor oil and derivatives thereof, plant-based waxes and animal waxes can also be used.

  Among these release agents, paraffin wax that is more easily included in the core particles is particularly preferable. The addition amount of the release agent is preferably in the range of 3.0 to 30.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Known colorants can be used as the colorant used in the toner of the present invention. Examples of the black colorant include carbon black and magnetic powder. Examples of yellow colorants include C.I. I. Pigment yellow 12, 13, 14, 15, 62, 73, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180, 185 and the like. Examples of magenta colorants include C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, 269 and the like. Examples of cyan colorants include C.I. I. Pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66, and the like.

  These colorants can be used alone or in combination, and further in the form of a solid solution. When magnetic powder is used as the black colorant, the amount added is preferably 40 to 150 parts by mass with respect to 100 parts by mass of the polymerizable monomer. When carbon black is used as the black colorant, the amount added is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer. In the case of a color toner, the preferable addition amount is 1 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  These colorants need to pay attention to polymerization inhibition and aqueous phase migration, and are preferably subjected to surface modification such as a hydrophobization treatment as necessary. For example, a preferable method for surface-treating a dye-based colorant includes a method in which a polymerizable monomer is polymerized in the presence of a dye in advance, and the obtained colored polymer is added to the monomer composition. . For carbon black, in addition to the same treatment as that for the dye, grafting may be performed with a substance (for example, polyorganosiloxane) that reacts with the surface functional group of carbon black.

  Moreover, it is preferable that the surface of the magnetic powder is uniformly hydrophobized with a coupling agent. Examples of the coupling agent that can be used include a silane coupling agent and a titanium coupling agent, and a silane coupling agent is particularly preferably used.

  The toner of the present invention can contain a charge control agent as necessary for the purpose of stabilizing the charge characteristics. As a method of inclusion, there are a method of adding to the inside of toner particles and a method of adding externally. As the charge control agent, a known one can be used, but when added inside, 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. Negative charge control agents include salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, metal compounds of aromatic carboxylic acids such as dicarboxylic acids; metal salts or metal complexes of azo dyes or azo pigments; sulfonic acid or carboxylic acid groups A high molecular compound having a side chain; boron compounds, urea compounds, silicon compounds, calixarene, and the like. Examples of the positive charge control agent include quaternary ammonium salts, polymer compounds having the quaternary ammonium salt in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  The amount of these charge control agents used is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method. Therefore, although it is not uniquely limited, in the case of internal addition, it is preferably in the range of 0.1 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. Used in In the case of external addition, the amount is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.3 part by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention contains inorganic fine powder for the purpose of improving fluidity. The inorganic fine powder is preferably added externally to the toner particles and mixed. Examples of the inorganic fine powder include titanium oxide fine powder, silica fine powder, and alumina fine powder. It is particularly preferable to use silica fine powder.

As the inorganic fine powder, those having a specific surface area by nitrogen adsorption measured by BET method of 30 m ² / g or more, particularly those in the range of 50 to 400 m ² / g are preferably used. The inorganic fine powder is preferably used in an amount of 0.1 to 5.0 parts by weight, more preferably 0.1 to 3.0 parts by weight, based on 100 parts by weight of the toner particles.

  The toner of the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a magnetic carrier. In particular, in the one-component development method, since there are many opportunities for the developer and each member to be in direct contact with each other, each member is easily contaminated due to the deterioration of the developer. For this reason, the toner of the present invention, which does not easily cause the coating layer to be detached and hardly deteriorates, is particularly excellent as a one-component developer. When used as a two-component developer, the average particle size of the carrier to be mixed is preferably 10 to 100 μm, and the toner concentration in the developer is preferably 2 to 15% by mass.

The weight average molecular weight (Mw), number average molecular weight (Mn), and maximum value (Mp) of the molecular weight distribution by GPC are values determined by the following method. A sample to be measured is put in THF (tetrahydrofuran) and left at room temperature for 24 hours. This is filtered through a solvent-resistant membrane filter “Maeshori Disc” (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is 0.8% by mass. Using this sample solution, measurement is performed under the following conditions.
Apparatus: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: Seven series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: THF
Flow rate: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

  In calculating the molecular weight of the sample, a molecular weight calibration curve prepared using the following standard sample is used. Polymer Laboratories standard polystyrene Easy PS-1 (Molecular weights 750,000, 841700, 148000, 28500, 2930, and molecular weights 256,000, 320,000, 59500, 9920, 580) and PS-2 (Molecular weights 377400, 96000, 19720) , 4490, 1180 and mixtures of molecular weights 188700, 46500, 9920, 2360, 580). An RI (refractive index) detector is used as the detector.

The content of the THF-insoluble component of the toner is measured by the Soxhlet extraction method shown below. Cylindrical filter paper (for example, Toyo Filter Paper No. 86R can be used) is vacuum-dried at a temperature of 40 ° C. for 24 hours, and then left in an environment adjusted to a temperature and humidity of 25 ° C. and 60% RH for 3 days. Weigh 2.0 g of the sample to be measured on this cylindrical filter paper, and let the weight of the sample at this time be W1 (g). Using a Soxhlet extractor, 200 ml of THF or IPA is used as a solvent, and extraction is performed for 24 hours in an oil bath at a temperature of 90 ° C. Thereafter, the cylindrical filter paper is gently taken out and vacuum-dried at a temperature of 40 ° C. for 24 hours. After leaving this in an environment adjusted to a temperature of 25 ° C. and a humidity of 60% RH for 3 days, the amount of solid content remaining on the cylindrical filter paper is weighed, and this is defined as W2 (g). The content of THF-insoluble matter is calculated from the following formula.
Content of THF-insoluble component of sample (mass%) = (W2 / W1) × 100

  The glass transition point (Tg) of the toner, the resin to be used, and the core particles is measured using a differential scanning calorimeter (DSC). Specifically, for example, Q1000 (manufactured by TA Instruments) can be used as the DSC. In the measurement method, 4 mg of a sample is precisely weighed in an aluminum pan, an empty aluminum pan is used as a reference pan, and measurement is performed in a nitrogen atmosphere with a modulation amplitude of 1.0 ° C. and a frequency of once / minute. The measurement temperature was held at 10 ° C. for 10 minutes, and then a reversing heat flow curve obtained by scanning from 10 ° C. to 180 ° C. at a heating rate of 1 ° C./min was used as a DSC curve, and the midpoint method was used. To obtain Tg. The glass transition point determined by the midpoint method is the glass transition point at the intersection of the baseline before the endothermic peak and the baseline after the endothermic peak in the DSC curve at elevated temperature and the rising curve. It is.

The zeta potential of the core particles and resin fine particles can be measured using a laser Doppler electrophoresis type zeta potential measuring device. Specifically, it can be measured using Zetasizer Nano ZS (model: ZEN3600, manufactured by Malvern Instruments Ltd). The core particles or resin fine particles are adjusted with ion-exchanged water so that the solid content concentration is 0.05% by mass. Adjust the pH to 7.0 with hydrochloric acid or sodium hydroxide. 20 ml of this dispersion is dispersed for 3 minutes using an ultrasonic cleaner (BRANSONIC 3510, manufactured by BRANSON). Using this, the value of Zeta Potential (mV) obtained by measurement by the method recommended in the instruction manual, except for the following conditions, is Z _C (mV) for the core particles, and Z _S (mV) for the resin fine particles. ).
-Cell: DTS1060C-Clear disposable zeta cell
・ Dispersant: water
・ Measurement duration: Automatic
・ Model: Smolchowski
・ Temperature: 25.0 ° C
・ Result Calculation: General Purpose

  The acid value of the resin is determined as follows. Basic operation conforms to JIS-K0070. The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acid groups and the like contained in 1 g of a sample is referred to as an acid value, and is measured by the following method.

(1) Reagent (a) Preparation of solvent As a sample solvent, an ethyl ether-ethyl alcohol mixture (1 + 1 or 2 + 1) or a benzene-ethyl alcohol mixture (1 + 1 or 2 + 1) is used. These solutions are neutralized with a 0.1 mol / l potassium hydroxide ethyl alcohol solution using phenolphthalein as an indicator immediately before use.
(B) Preparation of phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) Preparation of 0.1 mol / l potassium hydroxide-ethyl alcohol solution Dissolve 7.0 g of potassium hydroxide in as little water as possible, add 1 liter of ethyl alcohol (95 v / v%), and leave it for 2 days. I have. The standardization is performed according to JISK 8006 (basic matters concerning titration during the reagent content test).

(2) Operation Weigh 10 g of sample correctly, add 100 ml of solvent and a few drops of phenolphthalein solution as an indicator, and shake well until the sample is completely dissolved. In the case of a solid sample, dissolve it by heating on a water bath. After cooling, this was titrated with a 0.1 mol / l potassium hydroxide-ethyl alcohol solution, and the neutralization end point was reached when the indicator continued to light red for 30 seconds.

(3) Calculation formula The acid value is calculated by the following formula.
A = B × f × 5.661 / S
A: Acid value (mgKOH / g)
B: Amount used of 0.1 mol / l-potassium hydroxide ethyl alcohol solution (ml)
f: 0.1 mol / l-factor of potassium hydroxide ethyl alcohol solution S: sample (g)

  Moreover, when calculating | requiring the acid value of the sulfonic acid group in resin fine particles, quantitative analysis of S element is performed, for example using a fluorescent X-ray-analysis apparatus (XRF), and the functional group equivalent contained in 1g of resin is made into potassium hydroxide. It can be calculated in terms of the amount.

  The weight average particle diameter D4 (μm) and the number average particle diameter D1 (μm) of the toner are specifically measured by the following method. As the apparatus, a precision particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electric resistance method equipped with an aperture tube of 100 μm 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, a solution obtained by dissolving special grade sodium chloride in ion-exchanged water so as to have a concentration of 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Before performing measurement and analysis, set the dedicated software as follows. On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and the Kd value is “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and 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) In a glass 250 ml round bottom beaker for exclusive use of Multisizer 3, 200 ml of the electrolytic aqueous solution is placed and 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) Put 30 ml of the aqueous electrolytic solution 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. 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water.
(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. A predetermined amount of ion-exchanged water is placed in a water tank of an ultrasonic dispersing device, and 2 ml of the above-mentioned Contaminone N is added to this 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, 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 (1) installed in the sample stand, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to 5%. The 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. When the graph / volume% is set with the dedicated software, the “average diameter” on the “analysis / volume statistics (arithmetic average)” screen is the weight average particle diameter (D4), and the graph / number% is set. The “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

  Hereinafter, the present invention will be specifically described with reference to production examples and examples. Note that “parts” and “%” in the following formulations are based on mass unless otherwise specified.

<Production Example 1 of Resin Fine Particle Dispersion>
(Production of polyester resin)
The following monomers are charged into a reaction vessel equipped with a stirrer, condenser, thermometer, and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate is added as an esterification catalyst, and the temperature is raised to 220 ° C. in a nitrogen atmosphere. Then, the reaction was carried out for 5 hours with stirring.
Bisphenol A-propylene oxide 2-mole adduct (BPA-PO): 48.0 parts by mass Ethylene glycol: 9.1 parts by mass Terephthalic acid: 25.0 parts by mass Isophthalic acid: 10.0 parts by mass 5-sodium sulfoisophthalic acid : 7.9 parts by mass Subsequently, the reaction vessel was further reacted for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg, whereby a polyester resin 1 was obtained.

(Preparation of resin fine particle dispersion)
A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 100.0 parts by mass of the obtained polyester resin 1, 45.0 parts by mass of methyl ethyl ketone, and 45.0 parts by mass of tetrahydrofuran, and heated to 85 ° C. And dissolved. Next, under stirring, 300.0 parts by mass of ion-exchanged water at 85 ° C. was added and dispersed in water, and then the resulting aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C. It was. After cooling, ion-exchanged water was added to the obtained aqueous dispersion to adjust the resin concentration in the dispersion to 20%. This was designated as resin fine particle dispersion 1.

<Production Examples 2 to 11 of resin fine particle dispersion>
Resin fine particle dispersions 2 to 11 were prepared in the same manner as in Production Example 1 of the resin fine particle dispersion, except that the reaction conditions for producing the polyester resin, the types of raw materials, and the amounts used were changed as shown in Table 1. Created.

  For the resin fine particle dispersions 1 to 11, the average particle size (D50) of the fine particles in each dispersion was measured using a laser diffraction / scattering particle size distribution measuring apparatus. Further, the zeta potential of each dispersion was measured. Further, the weight average molecular weight (Mw), acid value, and glass transition temperature Tg2 of the resin used in each dispersion were measured. The acid value of the resin fine particle dispersion was obtained by measuring the amount of sulfur element in each resin using a fluorescent X-ray analyzer (XRF) and calculating it. The results are shown in Table 1.

<Preparation of polyester resin 12>
The following monomers were charged in a reaction vessel equipped with a stirrer, condenser, thermometer, and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 220 ° C. in a nitrogen atmosphere. The reaction was carried out for 5 hours with stirring.
Bisphenol A-propylene oxide 2 mol adduct: 47.2 parts by mass Ethylene glycol: 7.8 parts by mass Terephthalic acid: 21.8 parts by mass Isophthalic acid: 11.7 parts by mass Next, trimellitic anhydride 11.5 parts by mass Was added, and the reaction was further carried out for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg to obtain a polyester resin 12. The weight average molecular weight (Mw) of the polyester resin 12 was 18300, the acid value was 33.5 mgKOH / g, and the glass transition temperature was 68.7 ° C.

<Preparation of polyester resin 13>
The following monomers were charged in a reaction vessel equipped with a stirrer, condenser, thermometer, and nitrogen introduction tube, 0.03 parts by mass of tetrabutoxy titanate was added as an esterification catalyst, and the temperature was raised to 220 ° C. in a nitrogen atmosphere. The reaction was carried out for 5 hours with stirring.
Bisphenol A-propylene oxide 2 mol adduct: 53.5 parts by mass Ethylene glycol: 5.0 parts by mass Terephthalic acid: 17.7 parts by mass Isophthalic acid: 1.8 parts by mass Next, 22.0 parts by mass of trimellitic anhydride Was added, and the reaction was further carried out for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg to obtain a polyester resin 13. The weight average molecular weight (Mw) of the polyester resin 13 was 36500, the acid value was 64.1 mgKOH / g, and the glass transition temperature was 82.6 degreeC.

<Production Example 1 of Core Particle Dispersion>
(Preparation of pigment dispersion paste)
Styrene: 60.0 parts by mass Cu phthalocyanine (Pigment Blue 15: 3): 8.0 parts by mass After sufficiently premixing the above materials in a container, the attritor (manufactured by Mitsui Miike Chemical Co., Ltd.) is kept at 20 ° C. or less. Was uniformly dispersed and mixed for about 4 hours to prepare a pigment dispersion paste.

(Preparation of core particles)
390.0 parts by mass of 0.1 mol / l-sodium phosphate (Na ₃ PO ₄ ) aqueous solution was added to 700.0 parts by mass of ion-exchanged water, and the mixture was stirred using CLEARMIX (M Technique Co., Ltd.). After heating to 60 ° C., 60.0 parts by mass of 1.0 mol / l-calcium chloride (CaCl ₂ ) aqueous solution was added and stirring was continued, and the mixture was composed of tricalcium phosphate (Ca ₃ (PO ₄ ) ₂ ). An aqueous medium containing a dispersion stabilizer was prepared.

On the other hand, the following materials were added to the pigment dispersion paste and dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a monomer composition.
n-Butyl acrylate: 40.0 parts by mass Amorphous polyester: 5.0 parts by mass (polycondensate of bisphenol A propylene oxide 2 mol adduct and isophthalic acid, Tg = 58 ° C., Mw = 7800, acid value 13 )
Aluminum salicylate compound: 0.5 part by mass (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
Divinylbenzene: 0.2 part by mass The monomer composition was heated to 60 ° C., and wax (HNP-10: manufactured by Nippon Seiwa Co., Ltd.): 10.5 parts by mass was added and mixed and dissolved. Subsequently, 15.0 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added and dissolved as a polymerization initiator. This was put into the aqueous medium, and granulated by stirring for 10 minutes at 12000 rpm in a nitrogen atmosphere at 60 ° C. using CLEARMIX (M Technique Co., Ltd.). Furthermore, the obtained suspension was subjected to polymerization at 90 ° C. (polymerization temperature) for 10 hours while stirring with a paddle stirring blade at a rotation speed of 150 rotations / minute.

  After the completion of the polymerization, the obtained dispersion of polymer particles was cooled and adjusted so that the concentration of polymer particles in the dispersion was 20%. This was designated as core particle dispersion 1, and the physical properties of the dispersion were measured. A part of the sample was dried to obtain a sample for DSC measurement. Table 2 shows the physical properties of the core particle dispersion 1.

<Production Examples 2-18 of Core Particle Dispersion>
In the production example 1 of the core particle dispersion, the core particle dispersions 2 to 18 were obtained in the same manner as in the production example 1 of the core particle dispersion except that the amount of raw materials used and the polymerization temperature were changed to the conditions shown in Table 2. It was. The physical properties of the core particle dispersions 2 to 18 were measured in the same manner as in Production Example 1 of the core particle dispersion. The physical properties are shown in Table 2.

<Example 1>
(Production of toner particles)
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, the core particle dispersion 1: 500.0 parts by mass (solid content: 100.0 parts by mass) and the resin fine particle dispersion 1: 15.0 parts by mass. (Solid content: 3.0 parts by mass) was added and stirred at 200 rpm for 15 minutes to obtain a composite dispersion. Subsequently, it heated at 55 degreeC, stirring at 200 rotation / min. Subsequently, 0.2 mol / l of dilute hydrochloric acid was added dropwise to the dispersion at a dropping rate of 1.0 part by mass / min, and the addition of dilute hydrochloric acid was continued until the pH of the dispersion reached 1.3. Stirring was further continued for 3 hours to obtain a dispersion having resin fine particles fixed to the core particles. (Heating process 1)
While stirring the dispersion obtained by passing through the above steps and having the fine resin particles fixed to the core particles at 200 rpm, a 1.0 mol / l sodium hydroxide aqueous solution was added at a dropping rate of 10.0 parts by mass / min. The solution was added dropwise to adjust the pH of the dispersion to 7.1. The dispersion was heated to 72 (° C.) and further stirred for 1 hour (heating step 2). The mixture was cooled to 20 ° C., filtered and dried to obtain toner particles 1.

(External addition process)
Toner particles 1: Hydrophobic titanium oxide treated with nC ₄ H ₉ Si (OCH ₃ ) ₃ on 100.0 parts by mass (BET specific surface area: 110 m ^{2 /} g): 1.3 parts by mass and hexamethyldi Toner 1 was obtained by adding 0.7 parts by mass of hydrophobic silica (BET specific surface area of 150 m ^{2 /} g) treated with silicone oil after silazane treatment and mixing with a Henschel mixer. For toner 1, the glass transition point, particle diameter (D4, D1), Mp, Mw, and THF-insoluble content were measured. The physical properties of Toner 1 are shown in Tables 4 and 5.

<Examples 2 to 13, Comparative Examples 4 to 6, 8, and 9>
In Example 1, toners 2 to 13 and 18 to 20 were prepared in the same manner as in Example 1 except that the conditions of the core particles and resin fine particles used, the heating process 1 and the heating process 2 were changed to the conditions shown in Table 3. 22 and 23 were obtained.
The physical properties of each toner are shown in Tables 4 and 5.

<Example 14>
(Preparation of pigment dispersion paste)
Styrene: 68.0 parts by mass Cu phthalocyanine (Pigment Blue 15: 3): 8.0 parts by mass After the above materials were sufficiently premixed in a container, an attritor (manufactured by Mitsui Miike Chemical Co., Ltd.) was kept at 20 ° C. or lower. ) Was uniformly dispersed and mixed for about 4 hours to prepare a pigment dispersion paste.

(Production of toner particles)
While putting 390.0 parts by mass of 0.1 mol / l-sodium phosphate (Na ₃ PO ₄ ) aqueous solution into 700.0 parts by mass of ion-exchanged water and stirring using CLEARMIX (M Technique Co., Ltd.), After heating to 60 ° C., 60.0 parts by mass of 1.0 mol / l-calcium chloride (CaCl ₂ ) aqueous solution was added and stirring was continued, and the mixture was composed of tricalcium phosphate (Ca ₃ (PO ₄ ) ₂ ). An aqueous medium containing a dispersion stabilizer was prepared.

On the other hand, the following materials were added to the pigment dispersion paste and dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a monomer composition.
n-Butyl acrylate: 32.0 parts by mass Amorphous polyester: 5.0 parts by mass (Condensation product of bisphenol A propylene oxide 2 mol adduct and isophthalic acid, Tg = 58 ° C., Mw = 7800, acid value 13 )
Polyester resin 12: 10.0 parts by mass obtained by the production of the polyester resin 12 Polyester resin 13: 15.0 parts by mass of the aluminum salicylate compound obtained by the production of the polyester resin 13: 0.5 parts by mass (Bontron E -88: manufactured by Orient Chemical Co.)
Divinylbenzene: 0.2 part by mass The monomer composition was heated to 60 ° C., and wax (HNP-10: manufactured by Nippon Seiwa Co., Ltd.): 10.5 parts by mass was added and mixed and dissolved. Next, 15.0 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was further added and dissolved. This was put into the aqueous medium, and granulated by stirring for 10 minutes at 12000 rpm in a nitrogen atmosphere at 60 ° C. using CLEARMIX (M Technique Co., Ltd.). Furthermore, the obtained suspension was polymerized at 85 ° C. (polymerization temperature) for 10 hours while stirring with a paddle stirring blade at a rotation speed of 150 rotations / minute. After completion of the polymerization, the obtained dispersion of polymer particles was cooled, diluted hydrochloric acid was added to adjust the dispersion to pH 1.5, followed by filtration, washing and drying to obtain toner particles 14.

(External addition process)
The resulting toner particles 14 were externally added in the same manner as in Example 1 to obtain toner 14. The physical properties of the toner are shown in Tables 4 and 5.

<Comparative Example 1>
(Production of toner particles)
Dilute hydrochloric acid was added to the core particle dispersion 2 obtained in Production Example 2 of the core particle dispersion to adjust the dispersion to pH 1.3, followed by filtration, washing and drying.

(External addition process)
The toner particles obtained were externally added in the same manner as in Example 1 to obtain toner 15. The physical properties of the toner are shown in Tables 4 and 5.

<Comparative Example 2>
(Preparation of core particles)
Dilute hydrochloric acid was added to the core particle dispersion 2 obtained in Production Example 2 of the core particle dispersion to adjust the dispersion to pH 1.5, followed by filtration, washing and drying.

(Production of toner particles)
A dry product of the core particles 2: 100.0 parts by mass and a dry product of the resin fine particles 11: 5.0 parts by mass were mixed for 3 minutes at 2000 rpm using a Henschel mixer, and then hybridizer type 1 (Nara Machinery) And processed at 6000 rpm for 5 minutes to obtain surface-treated toner particles.

(External addition process)
The obtained toner particles were externally added in the same manner as in Example 1 to obtain toner 16. The physical properties of the toner are shown in Tables 4 and 5.

<Comparative Example 3>
(Preparation of pigment dispersion paste)
Styrene: 68.0 parts by mass Cu phthalocyanine (Pigment Blue 15: 3): 8.0 parts by mass After sufficiently premixing the above materials in a container, the attritor (manufactured by Mitsui Miike Chemical Co., Ltd.) is kept at 20 ° C. or less. Was uniformly dispersed and mixed for about 4 hours to prepare a pigment dispersion paste.

(Production of toner particles)
While putting 390.0 parts by mass of 0.1 mol / l-sodium phosphate (Na ₃ PO ₄ ) aqueous solution into 700.0 parts by mass of ion-exchanged water and stirring using CLEARMIX (M Technique Co., Ltd.), After heating to 60 ° C., 60.0 parts by mass of 1.0 mol / l-calcium chloride (CaCl ₂ ) aqueous solution was added and stirring was continued, and the mixture was composed of tricalcium phosphate (Ca ₃ (PO ₄ ) ₂ ). An aqueous medium containing a dispersion stabilizer was prepared.

On the other hand, the following materials were added to the pigment dispersion paste and dispersed and mixed using an attritor (manufactured by Mitsui Miike Chemical Industries) to prepare a monomer composition.
n-butyl acrylate: 32.0 parts by mass Polyester resin produced in Production Example 1 of the above resin fine particle dispersion 1: 20.0 parts by mass Aluminum salicylate compound: 0.5 parts by mass (Bontron E-88: manufactured by Orient Chemical Co., Ltd.) )
Divinylbenzene: 0.2 part by mass The monomer composition was heated to 60 ° C., and wax (HNP-10: manufactured by Nippon Seiwa Co., Ltd.): 10.5 parts by mass was added and mixed and dissolved. Subsequently, 15.0 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was further added and dissolved as a polymerization initiator. This was put into the aqueous medium, and granulated by stirring for 10 minutes at 12000 rpm in a nitrogen atmosphere at 60 ° C. using CLEARMIX (M Technique Co., Ltd.). Furthermore, the obtained suspension was subjected to polymerization at 90 ° C. (polymerization temperature) for 10 hours while stirring with a paddle stirring blade at a rotation speed of 150 rotations / minute. After the completion of the polymerization, the obtained dispersion of polymer particles was cooled, diluted hydrochloric acid was added to adjust the dispersion to pH 1.5, and then filtered, washed and dried to obtain toner particles 17.

(External addition process)
The obtained toner particles 17 were externally added in the same manner as in Example 1 to obtain toner 17.
The physical properties of the toner are shown in Tables 4 and 5.

<Comparative Example 7>
In Example 1, instead of the core particle dispersion 1, the core particle dispersion 16 was used, and instead of the resin fine particle dispersion 1: 15.0 parts by mass (solid content: 3.0 parts by mass), the resin fine particles Dispersion 9: 50.0 parts by mass (solid content: 10.0 parts by mass) was used. Further, in the heating step 1, 0.2 mol / l dilute hydrochloric acid was not added dropwise and stirred for 3 hours. Thereafter, heating step 2 was not performed. A toner 21 was obtained in the same manner as in Example 1 except for the above conditions.
The physical properties of the toner are shown in Tables 4 and 5.

  The toners prepared in the above examples and comparative examples were evaluated according to the procedure described below. The results are shown in Table 6.

<Heat resistant storage stability test method>
5 g of toner is weighed into a 100 ml capacity polycup and placed in a thermostatic chamber with an internal temperature of 50.0 ° C. and left for 14 days. Thereafter, the polycup is taken out, and the state change of the toner inside is visually evaluated. The evaluation criteria are as follows.
A: No change B: There is an aggregate, but loosens immediately C: There are a few aggregates, but loosens when shock is applied D: Many aggregates are not easily loosened E: Little loosened

<Evaluation methods for low-temperature fixability, penetration resistance, and offset resistance>
A commercially available color laser printer (LBP-5500, manufactured by Canon Inc.) was used, and the toner from the cyan cartridge was taken out and filled with the toner. The cartridge is mounted on a cyan station, and an unfixed toner image (0.8 mg / cm ² ) of 2.0 cm in length and 15.0 cm in width is passed through an image receiving paper (Canon office planner, 64 g / m ² ). It formed in the part of 2.0 cm from the upper end part and 2.0 cm from the lower end part with respect to the paper direction. Next, the fixing unit removed from the commercially available color laser printer (LBP-5500, manufactured by Canon) was remodeled so that the fixing temperature and process speed could be adjusted, and a fixing test for unfixed images was performed using this. Under normal temperature and normal humidity, the process speed was set to 260 mm / second, and the toner image was fixed at each temperature while changing the set temperature every 5 ° C. within the range of 120 ° C. to 240 ° C. According to the following evaluation criteria, low temperature offset resistance, rubbing resistance, penetration resistance, and high temperature offset resistance were evaluated.

<Low temperature offset resistance>
A: Low temperature offset does not occur when fixing at 120 ° C. or higher B: Low temperature offset does not occur when fixing at 130 ° C. or higher C: Low temperature offset does not occur when fixing at 140 ° C. or higher D: Low temperature offset occurs when fixing at 150 ° C. or higher Does not occur E: Low temperature offset does not occur when fixing at 160 ° C or higher

<Abrasion resistance>
The image obtained by the above method was rubbed with Silbon paper at 5 reciprocations of 0.98 N (100 g load), and the peeling of the image was evaluated by the density reduction rate (%) of the reflection density.
A: Density reduction rate (%) becomes 10% or less by fixing at 125 ° C. or higher B: Density reduction rate (%) becomes 10% or less by fixing at 135 ° C. or higher C: Density reduction by fixing at 145 ° C. or higher The rate (%) becomes 10% or less. D: The density reduction rate (%) becomes 10% or less by fixing at 155 ° C. or higher. E: The density reduction rate (%) becomes 10% or less by fixing at 165 ° C. or higher.

<Evaluation criteria for penetration resistance>
Using a handy gloss meter PG-3D (manufactured by Nippon Denshoku Industries Co., Ltd.), the gloss was measured under the condition of a light incident angle of 75 °. Gloss values of the image glossiness becomes the highest value (t _1), the gloss value of an image created at a temperature + 10 ° C. fixing device when creating the image (t ₂₎ and rate of change [rate of change ( %) = (T ₁ −t ₂ ) × 100 / t ₁ ] was evaluated according to the following criteria.
A: Gloss change rate is less than 5% B: Gloss change rate is 5% or more and less than 10% C: Gloss change rate is 10% or more and less than 15% D: Glossiness Change rate is 15% or more and less than 20% E: Change rate of glossiness is 20% or more

<Evaluation criteria for high-temperature offset performance>
A: Minimum temperature at which low temperature offset does not occur + No high temperature offset at a temperature range of 70 ° C. or higher B: Lowest temperature at which low temperature offset does not occur + No high temperature offset at a temperature range of 60 ° C. or higher C: Lowest at which low temperature offset does not occur High temperature offset does not occur in the temperature range of temperature + 50 ° C. or higher D: Minimum temperature at which low temperature offset does not occur + High temperature offset does not occur at temperature range of 40 ° C. or higher E: Minimum temperature at which low temperature offset does not occur + temperature range of 30 ° C. or higher No high temperature offset

<Durability test method>
A commercially available color laser printer (LBP-5900SE, manufactured by Canon Inc.) was used to take out the toner from the cyan cartridge, and 120 g of the toner was filled therein. The cartridge was allowed to stand for 30 days in an environment of a temperature of 30 ° C. and a humidity of 90% RH. This cartridge is installed in the cyan station of the printer, and is used at room temperature and normal humidity (23 ° C., 60% RH) and image receiving paper (Canon office planner, 64 g / m ² ). Continuous printing was performed. Durability was evaluated according to the following evaluation criteria.
A: No image defect occurs and the image quality is particularly excellent B: Image defect does not occur and the image quality is excellent C: Image defect does not occur and the image quality is good D: Image defect occurs Or, the image quality is inferior to C. E: An image defect occurs and the image quality is inferior to D.

Claims (7)

A toner comprising core particles containing at least a binder resin, a colorant, and a release agent, toner particles having a coating layer covering the core particles, and inorganic fine powder,
Measurement temperature (° C.) in the x-axis direction, and ratio (G′10 / G′1) of storage elastic modulus (G′1) at a frequency of 1 Hz and storage elastic modulus (G′10) at a frequency of 10 Hz in the y-axis direction The temperature-G′10 / G′1 curve created by plotting the curve has a peak Ta at 35.0 to 60.0 ° C., a peak Tb at 65.0 to 90.0 ° C., and 95 A toner having a peak Tc at 0.0 to 135.0 ° C.   In the temperature-G′10 / G′1 curve, there is a bottom Td between the Ta and the Tb, and the value (G′b) of G′10 / G′1 in the Tb and the Td The toner according to claim 1, wherein a difference (G′b−G′d) from a value of G′10 / G′1 (G′d) is 1.00 to 5.00.   In the temperature-G′10 / G′1 curve, there is a bottom Te between the Tb and the Tc, and the G′b and the value of G′10 / G′1 in the Te (G′e The toner according to claim 1, wherein a difference (G′b−G′e) with respect to (A) is 0.20 to 4.00.   The molecular weight distribution in terms of polystyrene by gel permeation chromatography of a THF-soluble component has a maximum value (Mp) at a molecular weight of 4000 to 18000 and a weight average molecular weight (Mw) of 10,000 to 150,000. The toner according to any one of 1 to 3.   The toner according to any one of claims 1 to 4, wherein the content of the THF-insoluble component by Soxhlet extraction method is 5.0 to 30.0% by mass.   The toner particles form a composite dispersion by adding a dispersion of resin fine particles to the dispersion in a step of forming a dispersion having the core particles in an aqueous medium having a poorly water-soluble inorganic dispersant. It forms through the process, the process of heating this composite dispersion liquid, and the process of melt | dissolving the said poorly water-soluble inorganic dispersing agent in this composite dispersion liquid. Toner.   The toner according to claim 6, wherein the dispersion of the resin fine particles has a zeta potential (Zs) of −110 or more and −50 mV or less.

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