JP5173484B2 - Toner production method - Google Patents

Description

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

  Various methods are known as image forming methods by electrophotography. Generally, an electrostatic latent image is formed on an electrostatic charge image bearing member (hereinafter also referred to as “photosensitive member”) by using a photoconductive substance by various means. Next, the electrostatic latent image is developed with toner to form a toner image. If necessary, the toner image is transferred onto a transfer material such as paper, and then the toner image is fixed on the recording medium by heat or pressure. Thus, a copy or a print is obtained. Such image forming apparatuses include printers and copiers.

  In recent years, these printers and copiers are required to increase the resolution of images by digitization, and at the same time, increase the printing or copying speed, or save space and reduce power consumption by downsizing the apparatus. Yes. Various types of fixing devices used in these printers and copiers have been put to practical use, but the most common method is a heat-pressing method using a heat roller. In this method, a fixing sheet as a recording medium to which toner is transferred is provided between a heat roller having a surface made of a material having releasability with respect to toner and a pressure roller that presses the surface. Fixing is performed by passing the toner image surface so as to be in contact with the heat roller side. In this method, since the surface of the heat roller and the toner image surface of the fixing sheet are in contact with each other under pressure, the toner is excellent in thermal efficiency when fusing onto the fixing sheet, and thus a particularly high speed is required. It is suitably used for applications. Further, as a method used for applications requiring low power consumption, a film fixing method can be mentioned as a representative method. This method uses a film unit equipped with a heating device in place of the heat roller, and performs fixing by passing a sheet to be fixed under a relatively low pressure between the film and the pressure roller. It is. In this method, the heat capacity of the film is small and the wait time can be shortened, so that the power consumption can be reduced.

  On the other hand, in order to satisfy the above-mentioned demands for higher speed and lower power consumption, improvement in fixing performance of the toner itself is also required. That is, it is desired to realize a toner that can be fixed at a lower temperature.

  Generally, when trying to improve the low-temperature fixability of a toner, a technique of lowering the glass transition temperature (hereinafter referred to as Tg) of the toner is taken. However, simply lowering the Tg reduces the heat-resistant storage stability of the toner, and a problem arises that a so-called blocking phenomenon in which agglomeration occurs between the toners in contact with each other in a high-temperature environment and a lump is likely to occur. Therefore, in order to improve the low-temperature fixability, the ability to prevent the blocking phenomenon (hereinafter referred to as blocking resistance) is essential.

  Various attempts to manufacture toner having a capsule structure have been proposed for this problem. That is, the present invention aims to achieve both low-temperature fixability and blocking resistance by forming a coating layer on the surface of core particles containing a resin having a low Tg with resin fine particles containing a resin having a high Tg.

  Conventionally, in order to enable fixing at a lower temperature, a technique of sharpening the binder resin is known as one of the effective methods. In this respect, the polyester resin has excellent characteristics. Show.

  As a wet method that can use a sharp melt polyester resin, a spherical toner is formed by dissolving a resin component in an organic solvent immiscible with water and dispersing the solution in an aqueous phase to form oil droplets. A so-called “dissolution suspension method” has been proposed (see Patent Document 1).

  According to this method, it is possible to easily obtain a spherical polyester toner having a small particle diameter by using polyester having excellent low-temperature fixability as a binder resin. Also for the toner particles produced by the dissolution suspension method, capsule-type toner particles having a so-called core-shell structure have been proposed.

  For example, toner base particles (core particles) are prepared by a dissolution suspension method in the presence of resin fine particles including any of vinyl resins, polyurethane resins, epoxy resins, polyester resins, or a combination thereof, and the toner base particles are formed using the fine particles. There has been proposed a method of adjusting toner particles coated on the surface (see Patent Documents 2 and 3).

  Further, after preparing toner particles (core particles) by a dissolution suspension method, a surfactant having a polarity different from the polar group on the toner particle surface and organic fine particles are added, and the organic fine particles are aggregated and adhered to the toner particle surface. Discloses a method of forming a coating layer (see Patent Document 4).

  In addition, after preparing the core particles by the dissolution suspension method, the vinyl resin fine particles obtained by soap-free emulsion polymerization are fixed to the core particles with a water-soluble polymerization initiator in a wet process to form a coating layer Is also disclosed (see Patent Document 5).

  Patent Documents 2 and 3 propose a method of preparing toner particles by a dissolution suspension method in the presence of polyurethane resin fine particles. However, the toner in which the polyurethane resin fine particles are arranged on the surface layer is not described in detail, and there is room for improvement in order to form a high-quality image excellent in low-temperature fixability and developability.

  In Patent Document 4, the charge of the organic fine particle dispersion in water is neutralized by the addition of a surfactant having a reverse polarity, so that the organic fine particles are aggregated and adhered to the surface of the toner particles. It is difficult to coat. Therefore, there is a possibility that sufficient blocking resistance cannot be obtained. In addition, the remaining organic fine particles aggregate and the surfactant remaining in the toner may adversely affect the charging stability.

  Also in Patent Document 5, although the vinyl resin fine particles are firmly fixed to the core particles by the water-soluble polymerization initiator, no means for forming a shell covering the entire surface of the core particles is taken. Therefore, further improvement of blocking resistance is considered necessary.

  In such a capsule-type toner, if the surface of the core particle is not uniformly coated with the coating layer, the toner is easily affected by the resin characteristics used for the core particle, and the blocking resistance is lowered.

  As described above, in the toner production method by the dissolution suspension method, particularly in a toner having a capsule structure in which the surface of core particles having a low Tg is coated with resin fine particles having a high Tg later, low-temperature fixability and resistance. At present, a toner that satisfies the blocking sufficiently has not been obtained yet.

JP-A-8-24868 JP 2004-226572 A JP 2004-271919 A JP 2005-24839 A JP-A-1-257856

  Accordingly, it is an object of the present invention to provide a toner manufacturing method that solves the above-described conventional problems.

  That is, an object of the present invention is to provide a toner production method having excellent low-temperature fixability and excellent blocking resistance particularly in the production of toner by a dissolution suspension method.

To achieve the above object, a manufacturing method of the toner of the present invention, the binder resin, a colorant and a solvent capable dissolving the binder resin at least containing, in the binder resin dissolved in the solvent the mixture in which the colorant is dispersed, a dispersion stabilizer is dispersed in an aqueous medium containing a form dissolved resin droplets, the solvent was removed from the soluble resin droplets, core particles containing core particles are dispersed dispersions (a) and the resulting Ru Engineering as (a),
To the core particle protégé dispersion liquid (A), the dispersion is the same as polarity the core particles to stabilizing agent, and then adding a resin fine particles having a higher than the binder resin Tg, the resin particles wherein the dispersion stabilizer as engineering to obtain a dispersion (B) having agent was allowed to adhere to the surface of the core particle while interposing particles (B),
The dispersion (B) temperature than Tg of the binder resin, and while holding Chi below Tg of the resin particles, the pH of the dispersion, the dispersion stabilizer is adjusted to a pH region exhibit solubility by removing the dispersion stabilizer by dissolving the dispersion stabilizer to obtain a dispersion (C) with said resin fine particles are fixed on the surface of the core particles particles (C)
The toner particles are generated by passing through at least.

  According to the present invention, it is possible to provide a toner excellent in blocking resistance while being a capsule toner excellent in low-temperature fixability, particularly in the dissolution suspension method.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

  Dissolved suspension toner is a dispersion-stabilized oil phase that contains a dissolved product obtained by dissolving or dispersing a binder resin, colorant, and if necessary a release agent and other additives in an organic solvent. A toner having particles obtained by dispersing in an aqueous medium containing an agent to form oil droplets and then removing the organic solvent. This method is excellent in that a resin that can be used as the binder resin has a wide range of versatility, and in particular, a polyester resin excellent in fixing ability can be used.

  In the present invention, in the toner production process by the dissolution suspension method, the particles contained in the dispersion liquid in which oil droplets are formed and the organic solvent is removed are used as the core particles.

  The present inventors pay attention to the dispersion stabilizer present on the surface of the core particle, and by adding resin fine particles having the same polarity as the core particle to the dispersion stabilizer, an electrical interaction with the dispersion stabilizer is achieved. By the action, the resin fine particles were uniformly attached to the surface of the core particles via a dispersion stabilizer. Furthermore, the inventors have found a method for removing the dispersion stabilizer without detaching resin fine particles adhering to the surface of the core particles, and have completed the present invention.

  In the present invention, it is necessary that the resin fine particles have a higher Tg than the binder resin. That is, the dispersion stabilizer is removed while maintaining the dispersion of the core particles to which the resin fine particles are uniformly adhered in a temperature range not lower than Tg of the binder resin and not higher than Tg of the resin fine particles. The fine resin particles are fixed on the surface while maintaining the dispersed state of the particles.

  By the above method, a uniform and strong resin fine particle layer can be formed on the surface of the core particle, thereby greatly improving the blocking resistance as a toner while maintaining the low temperature fixability of the core particle. Became possible.

  Hereinafter, an embodiment of a toner manufacturing method according to the present invention will be described in detail according to the steps.

  The granulation step in the present invention is a step for obtaining core particles.

  Specifically, first, the binder resin that is the main constituent material of the core particles is dissolved in an organic solvent in which the binder resin can be dissolved, and at least a colorant is added, and the homogenizer, ball mill, colloid mill, ultrasonic dispersion is added. A mixture in which these are uniformly dissolved or dispersed is prepared using a dispersing machine such as a machine.

  In this case, it is preferable to blend in the organic solvent in the range of 40% by mass to 60% by mass, although it varies depending on the viscosity and solubility of the binder resin as the binder resin component. When the binder resin is dissolved, heating at a temperature equal to or lower than the boiling point of the organic solvent is preferable because the solubility of the binder resin in the organic solvent is increased.

  At this time, a wax as a mold release agent, a charge control agent, and an additive such as a dispersant can be appropriately added to the mixture as necessary.

  Solvents that can be used as an organic solvent for dissolving the binder resin and the like include hydrocarbon solvents such as ethyl acetate, xylene, and hexane, halogenated hydrocarbon solvents such as methylene chloride, chloroform, and dichloroethane, methyl acetate, ethyl acetate, Examples thereof include ester solvents such as butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, and ketone solvents such as acetone, methyl ethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexane.

  Next, the mixture 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. Form.

  There is no restriction | limiting in particular as a stirring apparatus which has a rotary blade, If it is a general thing as an emulsifier and a disperser, it can be used.

  For example, Ultra Turrax (manufactured by IKA), Polytron (manufactured by Kinematica), TK Auto Homo Mixer (manufactured by Special Mechanized Industry Co., Ltd.), Ebara Milder (manufactured by Ebara Corporation), TK Homomic Line Flow (Made by Special Machine Industries Co., Ltd.), colloid mill (made by Shinko Pantech Co., Ltd.), thrasher, trigonal wet pulverizer (made by Mitsui Miike Chemical Co., Ltd.), Cavitron (made by Eurotech), fine flow mill Examples thereof include a continuous type emulsifier such as (manufactured by Taiheiyo Kiko Co., Ltd.), a batch type such as Claremix (manufactured by M Technique Co., Ltd.), and a fill mix (manufactured by Tokushu Kika Kogyo Co., Ltd.).

  When a high-speed shearing disperser is used, the number of revolutions is not particularly limited, but is usually 1000 to 30000 rpm, preferably 3000 to 20000 rpm.

  The dispersion time is usually 0.1 to 5 minutes in the batch method. The temperature during dispersion is usually 10 to 150 ° C. (under pressure), preferably 10 to 100 ° C.

  As an aqueous medium used in the present invention, water alone may be used, but a solvent miscible with water may be used in combination. Examples of the miscible solvent include alcohols such as methanol, isopropanol and ethylene glycol, cellsolves such as dimethylformamide, tetrahydrofuran and methyl cellosolve, and lower ketones such as acetone and methyl ethyl ketone. It is also a preferable production method that an appropriate amount of the organic solvent used as the mixture is mixed in the aqueous medium used in the present invention. This is considered to have the effect of enhancing the droplet stability during granulation and facilitating the suspension of the aqueous medium and the mixture.

  In order to remove the organic solvent from the dissolved resin droplets thus obtained, a method is adopted in which the temperature of the entire system is gradually raised and the organic solvent in the dissolved resin droplets is completely removed by evaporation. be able to. The organic solvent is removed from the dissolved resin droplets as described above to form an aqueous dispersion of core particles.

  In the present invention, the dispersion stabilizer is not removed, and the dispersion stabilizer is used in the subsequent adhesion step in a state dispersed in an aqueous medium.

  The attaching step in the present invention is a step of attaching resin fine particles to the core particles in the dispersion.

  In this step, while stirring the dispersion, resin fine particles having the same polarity as the core particle and having a Tg higher than that of the binder resin are added in a state of being dispersed in an aqueous medium. In this way, the resin fine particles can be densely and uniformly attached to the core particles in a state where the dispersion stabilizer is adsorbed on the surface.

  In the adhering step, it is preferable to slowly add the aqueous dispersion of the resin fine particles in order to prevent the resin fine particles from agglomerating and adhere more uniformly. A preferable addition rate is 0.1 parts by mass / min to 2.0 parts by mass / min as solids of resin fine particles with respect to 100 parts by mass of solids of the dispersion of core particles.

  Further, the fixing step in the present invention is a step of fixing the resin fine particles attached to the surface of the core particle via a dispersion stabilizer. In the present invention, the term “fixation” refers to a state in which the resin fine particles are fixed on the surface of the core particles with a strength that does not easily peel off or drop off.

  In this step, the dispersion is first heated to a temperature not lower than Tg of the binder resin and not higher than Tg of the resin fine particles. At this time, the core particles are in a soft state, but it is considered that the dispersed state can be maintained because the resin fine particles maintain a hardness that is sufficiently necessary to exhibit steric stability.

  Next, when the dispersion stabilizer existing between the core particles and the resin fine particles is removed while maintaining such a state, the resin fine particles adhered to the surface of the core particles until the removal is completed. It is considered that a part thereof is embedded in the core particle surface and the remaining part is exposed on the core particle surface.

  That is, the resin fine particles are stably fixed to the core particles in a state in which they are difficult to peel off. In this way, the present inventors believe that it is possible to form a finer, more uniform and stronger resin fine particle layer than in the past.

  In the fixing step, the dispersion stabilizer is preferably removed by controlling the pH of the dispersion.

  Removal of the dispersion stabilizer by adjusting the pH is a very simple technique. For example, when a colloid of a water-insoluble or hardly water-soluble inorganic compound is used as the dispersion stabilizer, the dispersion stabilizer is composed of core particles and resin fine particles. Even if it exists between them, it can be easily dissolved and removed by adjusting the pH region of the dispersion to the acidic side. Adjustment of pH can be normally performed by adding hydrochloric acid and a sulfuric acid.

  At this time, in order to keep the state of the resin fine particles adhering to the core particles uniform, it is preferable to slowly add the 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. The acid to be added is preferably used as an aqueous solution having a concentration of 0.1 mol / liter to 0.5 mol / liter.

  After this step, the toner particles can be obtained by filtration by a known method, washing and drying.

  In the fixing step, when the pH is not controlled only by setting the dispersion of the core particles to not less than Tg of the binder resin and not more than Tg of the resin particles, a dispersion stabilizer is provided between the resin particles and the core particles. Therefore, the adhesion between the resin fine particles and the core particles is low, and sufficient strength cannot be obtained.

  Also, in the fixing process, after the pH control, the dispersion liquid temperature is set to be not less than the Tg of the binder resin and not more than the Tg of the resin fine particles. For this reason, the resin fine particles cannot stably exist on the core particles. Therefore, there is no difference from the conventional method in which the resin fine particles are fixed to the core particles from which the dispersion stabilizer has been previously removed.

  As described above, the present invention can be achieved by uniformly attaching resin fine particles using the dispersion stabilizer used in the granulation step, and simultaneously removing the dispersion stabilizer and fixing the resin fine particles. Thus, it has been impossible to achieve the object of the present invention with the conventional method as described above.

  Further, in the present invention, after the fixing step, the dispersion stabilizer is reprecipitated so that the surface of the particles to which the resin fine particles are fixed is coated with the dispersion stabilizer, and the particles can be obtained even if heat treatment is performed to Tg or more of the resin fine particles. Aggregation between each other can be suppressed.

  Since the heating is performed to Tg or more of the resin fine particles, the layer made of the resin fine particles is smoothed to become a more uniform and dense layer. Through this smoothing step, the blocking resistance is further improved.

  Further, in the smoothing step, thermal spheroidization of the particles to which the resin fine particles are fixed occurs, and another effect of improving developability is obtained.

  In the smoothing step, the same dispersion stabilizer may be added separately when redispersing the dispersion stabilizer. A small amount of a surfactant can also be added.

  After the smoothing step, the dispersion stabilizer is removed with the acid as described above, filtered by a known method, washed and dried to obtain toner particles.

  In the present invention, the resin fine particles preferably cover 90% or more of the surface of the core particles. When the coating is 90% or less, the surface of the core particle is exposed and the blocking resistance is impaired.

  A more preferable range of the coverage is from 100% to 150%. In the present invention, a coating rate exceeding 100% indicates that the resin fine particle layer is a multilayer.

  That is, it is more preferable that the resin fine particles cover one or more core particles. However, if the coverage exceeds 150%, it is not preferable because sufficient fixing strength cannot be obtained.

  The coverage can also be obtained directly from an observation image of each toner cross section with a transmission electron microscope (TEM). However, when the resin fine particles contain an element specific to the resin (for example, a sulfonic acid group). S) derived from the above, a quantitative analysis of the element contained in the toner is performed using a fluorescent X-ray analyzer (XRF), and it can be obtained by calculation.

In the present invention, the average particle diameter of the resin fine particles is a median diameter value determined by particle size distribution measurement by a laser scattering method, and is preferably in the range of 10 to 100 nm. More preferably, it is used in the range of 30 to 70 nm. If the average particle size is less than 10 nm, the fine particles may be embedded in the core particles in the fixing step, and thus control is difficult. Further, when the average particle diameter exceeds 100 nm, it may be difficult to obtain sufficient fixing strength. Therefore, in any case, it becomes difficult to obtain a toner having sufficient blocking resistance.

  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).

  In the present invention, the suitable fixing amount of the resin fine particles is not uniquely determined, and may be appropriately adjusted according to the desired coverage and the particle diameters of the core particles and the resin fine particles. In the present invention, the fixed amount refers to the amount fixed to the core particle surface. In the range of the coverage and the average particle diameter described above, it is preferably in the range of 1.0 to 10.0% by mass. If the addition amount of the resin fine particles is less than 1.0%, it may be difficult to densely coat in the adhesion process. When the addition amount exceeds 10.0%, the resin fine particles once fixed are likely to be peeled off, and the toner fixability may be lowered.

  The resin fine particles used in the present invention are preferably composed of self-water dispersible resin fine particles having acidic groups.

  Self-water dispersible resin fine particles do not require the addition of a separate surfactant, and the dispersion capacity of the resin fine particles can be adjusted by adjusting the pH. Can be immobilized on the core particles. Examples of the acidic group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among these, a carboxyl group, a sulfonic acid group, or a combination thereof is preferably used, and at least a sulfonic acid group is included. This is particularly preferable in that good chargeability can be imparted to the toner.

  Further, the Tg of the resin fine particles is preferably 55 to 90 ° C. When Tg is lower than 55 ° C., it is difficult to obtain a sufficient effect of improving blocking resistance. On the other hand, when Tg is higher than 90 ° C., the low-temperature fixability is impaired.

  Further, the resin fine particles preferably have an acid value of 5.0 to 40.0 mgKOH / g. More preferably, it is used in the range of 10.0 to 25.0 mg KOH / g.

  When the acid value is less than 5.0 mgKOH / g, it is difficult to obtain fine particles having sufficient self-water dispersibility. Further, in the attaching step, the resin fine particles are difficult to adhere to the core particles. When the acid value is higher than 40.0 mgKOH / g, the hygroscopicity when the toner is formed is increased, and the charging stability may be impaired. In addition, the electric repulsion between the resin fine particles increases, and the resin fine particles that do not adhere to the surface of the core particles in the adhesion step and remain dispersed in the aqueous medium tend to increase.

  In addition, the acid value here represents content of the said acidic group, and when an acidic group is a salt state, it shows the value computed as what returned to the acid state. The acid value of the resin fine particles is represented by the amount of potassium hydroxide required to neutralize the functional group contained in 1 g of the resin, and is determined by the following method.

The basic operation is based on JISK-0070. This method is particularly suitable for obtaining the acid value of a carboxylic acid group.
1) First, 0.5 to 2.0 g of the sample is precisely weighed in a 300 ml beaker, and the weight at this time is defined as Wg. When the functional group of the sample is in a salt state, a sample that has been returned to an acid state in advance is used.
2) To this, 150 ml of a mixed solution of toluene / ethanol (4/1) is added and dissolved.
3) Titrate with 0.1 mol / l KOH ethanol solution. The titration can be performed, for example, using automatic titration using a potentiometric titration measuring device AT-400 (winworkstation) manufactured by Kyoto Electronics Co., Ltd. and an ABP-410 electric burette.
4) The consumption of the KOH solution at this time is Sml. At the same time, a blank is measured, and the consumption of KOH at this time is defined as Bml.
5) Calculate the acid value according to the following formula. In the formula, f is a factor of KOH.
Acid value (mgKOH / g) = {(SB) × 0.1f × 56.1} / W

  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.

  As a method for producing the self-water dispersible resin fine particles as described above, 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 solution of the resin undergoes phase inversion emulsification to produce fine particles. The organic solvent is removed using a method such as heating and decompression after phase inversion emulsification.

  Thus, according to the phase inversion emulsification method, a stable aqueous dispersion of resin fine particles can be obtained without substantially using an emulsifier or a dispersion stabilizer due to the action of the acidic group.

  The resin fine particles obtained in this way can be used for the adhesion process to the core particles as an aqueous dispersion as it is. Further, an acid may be added to the aqueous dispersion to return the acidic group in the resin from the salt state to the acid state, and after filtration and washing, the acid group may be redispersed in water.

  As the material of the resin, any resin can be used as long as it can be used as a binder resin for toner, and vinyl resins, polyester resins, epoxy resins, and urethane resins are used. Among them, polyester resins have sharp melt properties. Therefore, it is preferable that the core particles have a low temperature fixability.

  As the dispersion stabilizer used in the present invention, a surfactant, an organic dispersant, and an inorganic dispersant can be used, and among these, as described above, a colloid of a water-insoluble or poorly water-soluble inorganic salt is used. Is particularly preferable from the viewpoint of solubility in acids.

  In addition, since the inorganic salt has high thermal stability, even when the organic solvent is removed from the dissolved resin droplets at a high temperature, the droplets can be kept stable, and also in the fixing process, the resin adhered to the core particles. This is preferable because it can be fixed while maintaining the uniformity of the fine particles.

  These inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, sulfuric acid Barium is mentioned.

  Furthermore, in the present invention, since the dispersion stabilizer is reprecipitated and used in the smoothing step, it is preferably reversible with respect to pH.

  Among the inorganic dispersants described above, tricalcium phosphate can be particularly preferably used because it can be dissolved and precipitated reversibly in the pH range of 3 to 5.

  These dispersion stabilizers are preferably used in an amount of 0.01 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  As the binder resin used in the present invention, various resins conventionally known as binder resins for electrophotography are used. Among them, (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl copolymer unit, (c) a mixture of the hybrid resin and the vinyl copolymer, (d) a hybrid resin and a polyester. A mixture of a resin, (e) a mixture of a polyester resin and a vinyl copolymer, and (f) a polyester resin, a hybrid resin having a polyester unit and a vinyl copolymer unit, a vinyl copolymer, and It is preferable that a resin selected from the group consisting of

  Specific examples of the monomer that can be used in the binder resin of the present invention 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-propanediol, 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, the following formula (I)

（式中、Ｒはエチレンまたはプロピレン基を示し、ｘ，ｙはそれぞれ１以上の整数を示し、且つｘ＋ｙの平均値は２乃至１０を示す。）
で示されるビスフェノール誘導体、または下記式（ＩＩ）

(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 to 10.)
Or a bisphenol derivative represented by the following formula (II)

（式中、Ｒ’は−ＣＨ₂ＣＨ₂−、−ＣＨ₂ＣＨ（ＣＨ₃）−、または−ＣＨ₂−Ｃ（ＣＨ₃）₂−である。）
で示される化合物が挙げられる。

(In the formula, R ′ represents —CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) —, or —CH ₂ —C (CH ₃ ) ₂ —).
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, trimellit An acid etc. are mentioned.

  Among them, in particular, a bisphenol derivative represented by the general formula (II) and an alkyldiol having 2 to 6 carbon atoms as a diol component, a divalent carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof (For example, fumaric acid, maleic acid, maleic acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, alkyl dicarboxylic acid having 4 to 10 carbon atoms, and acid anhydrides of these compounds) Polyester obtained by polycondensation of these with an acid component is preferred 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.

  As a preferable method for producing the binder resin, a dehydration condensation reaction and a transesterification reaction may be mentioned.

  Furthermore, the Tg of the binder resin is preferably 20 to 50 ° C. When Tg is lower than 20 ° C., the storage stability of a copy or print on which a toner image is fixed is impaired. When Tg is higher than 50 ° C., the Tg difference between the resin fine particles to be fixed to the surface of the core particles and the core particles becomes small in the fixing step, so that the fixing is insufficient and the resin fine particles are likely to be peeled or detached.

  As the colorant used in the toner of the present invention, known ones can be used, and examples thereof include carbon black as a black colorant, magnetic powder, and yellow / magenta / cyan colorants shown below.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 are preferably used.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like are used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 are preferably used.

  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 binder resin. 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 binder resin. In the case of a color toner, it is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner, and the preferred addition amount is 1 with respect to 100 parts by mass of the binder resin. Thru | or 20 mass parts.

  In addition, the magnetic powder is mainly composed of iron oxide such as triiron tetroxide and γ-iron oxide, and since it is generally hydrophilic, it is magnetic by interaction with water as a dispersion medium. The powder tends to be unevenly distributed on the particle surface, and the resulting toner particles are inferior in fluidity and frictional charging uniformity due to the magnetic powder exposed on the surface. Therefore, the surface of the magnetic powder is preferably subjected to a hydrophobic treatment uniformly 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 preferably contains a release agent in order to improve fixability. Usable release agents include, for example, paraffin wax, microcrystalline wax, petroleum wax such as petrolatum and derivatives thereof, montan wax and derivatives thereof, hydrocarbon wax and derivatives thereof by Fischer-Tropsch method, and polyethylene. Examples thereof include polyolefin wax and derivatives thereof, carnauba wax, candelilla wax, natural wax and derivatives thereof. Derivatives include block copolymers with oxides and vinyl monomers, graft modified products, and the like. 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. These mold release agents may be used independently and may use 2 or more types together.

  Among these release agents, those having a maximum endothermic peak in the region of 40 to 130 ° C. at the time of temperature rise in the DSC curve measured by a differential differential calorimeter are preferable, and further in the region of 45 to 120 ° C. Is more preferable. By using such a release agent, the release property can be effectively expressed while greatly contributing to the low-temperature fixability. When the maximum endothermic peak is less than 40 ° C., the self-aggregating force of the release agent component becomes weak, and as a result, the high temperature offset resistance deteriorates.

  Here, the high temperature offset is a phenomenon in which the toner melted at the time of fixing adheres to the surface of the above-mentioned heat roller or fixing film, and this contaminates the subsequent fixing sheet.

  Further, exudation of the release agent is likely to occur at times other than during fixing, and the charge amount of the toner is reduced, and the durability under high temperature and high humidity is reduced. On the other hand, if the maximum endothermic peak exceeds 130 ° C., the fixing temperature becomes high and low temperature offset tends to occur, which is not preferable. Here, the low temperature offset is a phenomenon in which toner that is not sufficiently melted at the time of fixing adheres to the surface of the above-described heat roller or fixing film, which contaminates the subsequent fixing sheet. Furthermore, if the maximum endothermic peak temperature is too high, problems such as precipitation of the release agent component during granulation occur, and the dispersibility of the release agent decreases, which is not preferable.

  The content of the release agent is preferably 1 to 30 parts by mass and more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the binder resin. When the content of the release agent is less than 1 part by mass, a sufficient addition effect cannot be obtained and the offset suppressing effect is insufficient. On the other hand, when the amount exceeds 30 parts by mass, the long-term storage stability is deteriorated and the dispersibility of other toner materials such as a colorant is deteriorated, resulting in a decrease in toner fluidity and image characteristics. Further, exfoliation of the release agent component occurs other than at the time of fixing, resulting in poor durability under high temperature and high humidity.

  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 the toner particles inside and a method of externally adding them. As the charge control agent, known ones can be used, but when added inside, a charge control agent substantially free from a solubilized product in an aqueous dispersion medium is particularly preferable. Specific compounds include, as negative charge control agents, metal compounds of aromatic carboxylic acids such as salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, dicarboxylic acid, metal salts or metal complexes of azo dyes or azo pigments, Examples thereof include a polymer compound having a sulfonic acid or carboxylic acid group in the side chain, a boron compound, a urea compound, a silicon compound, and a calixarene. Examples of positive charge control agents include quaternary ammonium salts, polymer compounds having quaternary ammonium salts in the side chain, guanidine compounds, nigrosine compounds, and imidazole compounds.

  The amount of use of these charge control agents is determined by the toner production method including the type of binder resin, the presence or absence of other additives, and the dispersion method, and is not uniquely limited. In the case of internal addition, it is preferably used in the range of 0.1 to 10.0 parts by mass, more preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the binder resin. When externally added, the amount is preferably 0.005 to 1.000 parts by mass, more preferably 0.01 to 0.30 parts by mass with respect to 100 parts by mass of the toner.

  The toner of the present invention is preferably externally added with a fluidity improver to improve image quality. As the fluidity improver, inorganic fine powders of silicate fine powder, titanium oxide, and aluminum oxide are preferably used. These inorganic fine powders are preferably hydrophobized with a hydrophobizing agent such as a silane coupling agent, silicone oil or a mixture thereof.

  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. 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.

  Here, in the present invention, the glass transition temperature (Tg) of the binder resin and the resin fine particles can be determined as follows using, for example, a differential scanning calorimeter (Q1000) manufactured by TA Instruments. .

  First, about 6 mg of a sample is precisely weighed in an aluminum pan, and an empty aluminum pan is prepared as a reference pan. In a nitrogen atmosphere, the measurement temperature range is 20 to 150 ° C., the temperature rising rate is 2 ° C./min, and the modulation amplitude is ± 0. The measurement is performed at 6 ° C. and at a frequency of once / minute.

  From the reversing heat flow curve at the time of temperature rise obtained by measurement, draw a tangent line between the endothermic curve and the front and back baselines, find the midpoint of the straight line connecting the intersections of each tangent line, and this is the glass transition Let it be temperature.

  The weight average particle diameter (D4) of the core particles and the toner particles is a precise particle size distribution measuring apparatus “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube. And the dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) for measurement condition setting and measurement data analysis. The measurement data was analyzed and calculated.

  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, dedicated software was set up as follows.

  In the “Standard Measurement Method (SOM) Change Screen” of the dedicated software, set the total count in the control mode to 50000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter, Inc.) Set the value obtained using The threshold and noise level are automatically set by pressing the threshold / noise level measurement button. Also, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the aperture tube flash 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 aqueous solution is put 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 rotations / second. Then, dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the analysis software.

  (2) About 30 ml of the electrolytic aqueous solution is put in a glass 100 ml flat bottom beaker, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder pH 7 precision measurement is used as a dispersant therein. About 0.3 ml of a diluted solution obtained by diluting a 10% by weight aqueous solution of a neutral detergent for washing a vessel (made by Wako Pure Chemical Industries, Ltd.) 3 times with ion exchange water is added.

  (3) Two oscillators with an oscillation frequency of 50 kHz are incorporated in a state where the phase is shifted by 180 degrees, and placed in a water tank of an ultrasonic dispersion device “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W. A fixed amount of ion-exchanged water is added, and about 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, about 10 mg of core particles or toner particles are 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%. . 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) is calculated. The “average diameter” on the analysis / volume statistics (arithmetic average) screen when the graph / volume% is set with the dedicated software is the weight average particle diameter (D4).

  The average circularity of the toner obtained by the present invention is preferably 0.970 or more. The average circularity is an index representing the degree of unevenness of toner particles, and is 1.000 when the toner is a perfect sphere, and the value becomes smaller as the surface shape becomes more complicated. That is, that the average circularity is 0.970 or more means that the toner shape is substantially spherical. The toner having such a shape is likely to be uniformly charged, and is effective in suppressing fog and sleeve ghost. In addition, since the toner ears formed on the toner carrier are uniform, control in the developing unit is facilitated, and development stability performance is improved.

  Furthermore, since it has a spherical shape, it has good fluidity and is not easily stressed in the developing device, so that the chargeability is not easily lowered even when used for a long time under high humidity. Further, since heat and pressure are easily applied to the entire toner even at the time of fixing, it contributes to improvement of fixing properties.

  The average circularity in the present invention was measured using a flow type particle image analyzer (FPIA-3000 type) manufactured by Sysmex Corporation.

  As a specific measurement method, a suitable amount of a surfactant, preferably alkylbenzene sulfonate, is added to 20 ml of ion-exchanged water, 0.02 g of a measurement sample is added, and a desktop with an oscillation frequency of 50 kHz and an electrical output of 150 W is added. Dispersion treatment is carried out for 2 minutes using a type ultrasonic cleaner disperser (for example, VS-150 manufactured by VervoCrea Co., Ltd.) to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC.

  For the measurement, the flow type particle image measuring apparatus equipped with a standard objective lens (10 times) is used, and a particle sheath (PSE-900A) manufactured by Sysmex Corporation is used as the sheath liquid. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image measuring apparatus, 3000 toner particles are measured in the total count mode, and the analysis particle diameter is set to a circle equivalent diameter of 3.00 μm or more and 200.00 μm or less. Limit and determine the average circularity of the toner particles.

  In measurement, automatic focus adjustment is performed using standard latex particles (for example, a product obtained by diluting 5200A manufactured by Duke Scientific with ion-exchanged water) before the measurement is started. Thereafter, it is preferable to perform focus adjustment every two hours from the start of measurement.

  In the examples, a flow-type particle image measuring apparatus that has been calibrated by Sysmex Corporation and has been issued a calibration certificate issued by Sysmex Corporation has an analysis particle diameter of 3.00 μm or more. Except for limiting to 200.00 μm or less, measurement was performed under the measurement and analysis conditions when the calibration certificate was received.

  The toner of the present invention preferably has a maximum endothermic peak by a differential scanning calorimeter (DSC) at 60 to 140 ° C. The endothermic peak is derived from the melting point of the release agent contained in the toner, but the melting deformation of the toner in the fixing process is significantly accelerated from the time when the toner present in the image area is heated to a temperature higher than the melting point of the release agent. Is done. For this reason, when the amount of toner on the paper is reduced, it is easily affected by the melting behavior of the release agent in the fixing step. In addition, when an image is formed by reducing the amount of toner on the paper when the fixing process does not have an oil application mechanism or uses only a small amount of oil, the amount of toner present on the paper is small. Therefore, the release agent contained in the toner layer constituting the image is also reduced. For this reason, when trying to form an image with the same amount of image data with a smaller amount than when using normal toner, a low temperature offset and a high temperature offset are particularly likely to occur. When the temperature of the maximum endothermic peak is less than 60 ° C., when the release agent is melted in the fixing step, it is easy to dissolve in the binder resin and the melt viscosity of the toner is likely to be lowered. Further, when the release agent is melted in the fixing step, a part of the release agent is dissolved in the binder resin, and the toner release performance is likely to be deteriorated. For this reason, when the toner consumption is reduced and used, high temperature offset is remarkably likely to occur. On the other hand, when the maximum endothermic peak exceeds 140 ° C., when the release agent melts in the fixing step, the amount that dissolves in the binder resin is remarkably small, and it is difficult to obtain a plastic effect by the release agent. In addition, since the release agent having a maximum endothermic peak exceeding 140 ° C. has high crystallinity, when the amount of toner on the paper is reduced, the influence of the release agent crystals mixed in the fixed image is large, and the image that can be expressed. The color gamut tends to decrease. For this reason, the maximum endothermic peak is more preferably 60 to 95 ° C., and further preferably 65 to 90 ° C.

  For the same reason as described above, the maximum endothermic peak of the toner of the present invention preferably has a half width of 0.5 to 20.0 ° C. In addition, when the amount of toner on the paper is reduced, if the half width exceeds 20.0 ° C., gloss unevenness and density unevenness are likely to occur in the image in the first half and the second half in the sheet passing direction. When the half width is less than 0.5 ° C., an offset is likely to occur in the latter half of the sheet passing direction. Therefore, the full width at half maximum is more preferably 1.0 to 15.0 ° C, and particularly preferably 2.0 to 10.0 ° C.

  EXAMPLES Hereinafter, although a manufacture example and an Example demonstrate this invention concretely, these do not limit this invention at all.

[Synthesis Example 1: Resin fine particle dispersion (a)]
(Production of polyester resin)
The following monomers were charged into 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 210 ° C. in a nitrogen atmosphere. Then, the reaction was carried out for 5 hours with stirring.

Bisphenol A-propylene oxide 2-mol adduct: 49.2 parts by mass Ethylene glycol: 8.9 parts by mass Terephthalic acid: 21.7 parts by mass Isophthalic acid: 14.4 parts by mass 5-sodium sulfoisophthalic acid: 5.8 parts by mass Part

  Next, the reaction was further carried out for 5 hours while reducing the pressure inside the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

(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, 45.0 parts by mass of methyl ethyl ketone, and 45.0 parts by mass of tetrahydrofuran, and heated to 80 ° C. And dissolved.

  Next, under stirring, 300.0 parts by mass of ion-exchanged water at 80 ° 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 (a).

[Synthesis Example 2: Resin fine particle dispersion (b)]
(Production of polyester resin)
The following monomers were charged into 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. Warmed and reacted for 5 hours with stirring.

Bisphenol A-propylene oxide 2 mol adduct: 49.9 parts by mass Ethylene glycol: 9.0 parts by mass Terephthalic acid: 20.5 parts by mass Isophthalic acid: 13.7 parts by mass

  Next, 7.0 parts by mass of trimellitic anhydride was added, and the reaction was further performed for 5 hours while reducing the pressure in the reaction vessel to 5 to 20 mmHg to obtain a polyester resin.

(Preparation of resin fine particle dispersion)
In a reaction vessel equipped with a stirrer, condenser, thermometer, and nitrogen introduction tube, 100.0 parts by mass of the obtained polyester resin and 75.0 parts by mass of butyl cellosolve were charged and dissolved by heating to 90 ° C. Until cooled.

  Subsequently, 18.0 parts by mass of a 1 mol / liter aqueous ammonia solution was added, and the mixture was stirred for 30 minutes while maintaining the above temperature. Then, 300.0 parts by mass of ion-exchanged water at 70 ° C. was added and dispersed in water. . The obtained aqueous dispersion was transferred to a distillation apparatus and distilled until the fraction temperature reached 100 ° C.

  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 (b).

[Synthesis Examples 3 to 4: Resin fine particle dispersions (c) to (d)]
In Synthesis Example 1, the stirring time and the ion exchange water addition conditions were appropriately changed to obtain two types of polyester resin aqueous dispersions having different average particle diameters. This was designated as resin fine particle dispersions (c) and (d).

[Synthesis Example 5: Resin fine particle dispersion (e)]
In Synthesis Example 1, an aqueous dispersion of a polyester resin was obtained in the same manner as in Synthesis Example 1, except that the monomer charge was changed as follows. This was designated as resin fine particle dispersion (e).

Bisphenol A-propylene oxide 2 mol adduct: 50.0 parts by mass Ethylene glycol: 9.0 parts by mass Terephthalic acid: 23.5 parts by mass Isophthalic acid: 15.6 parts by mass 5-sodium sulfoisophthalic acid: 2.0 parts by mass Part

[Synthesis Example 6: Resin fine particle dispersion (f)]
In Synthesis Example 1, an aqueous dispersion of a polyester resin was obtained in the same manner as in Synthesis Example 1, except that the monomer charge was changed as follows. This was designated as resin fine particle dispersion (f).

Bisphenol A-propylene oxide 2-mol adduct: 46.5 parts by mass Ethylene glycol: 8.4 parts by mass Terephthalic acid: 15.1 parts by mass Isophthalic acid: 10.0 parts by mass 5-sodium sulfoisophthalic acid: 20.0 parts by mass Part

[Synthesis Example 7: Resin fine particle dispersion (g)]
In Synthesis Example 1, an aqueous dispersion of a polyester resin was obtained in the same manner as in Synthesis Example 1, except that the monomer charge was changed as follows. This was designated as resin fine particle dispersion (g).

Bisphenol A-propylene oxide 2-mol adduct: 62.4 parts by mass Ethylene glycol: 7.5 parts by mass Terephthalic acid: 12.4 parts by mass Isophthalic acid: 12.3 parts by mass Fumaric acid: 8.8 parts by mass 5-sodium Sulfoisophthalic acid: 5.4 parts by mass

[Synthesis Example 8: resin fine particle dispersion (h)]
(Production of styrene / acrylic resin)
A reaction vessel equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube was charged with 350.0 parts by mass of ion-exchanged water and 0.5 parts by mass of sodium dodecylbenzenesulfonate, and the temperature was raised to 90 ° C. in a nitrogen atmosphere. Then, 8 parts by mass of 2% aqueous hydrogen peroxide solution and 8 parts by mass of 2% ascorbic acid aqueous solution were added.

  Subsequently, the following monomer mixture, aqueous emulsifier solution and aqueous polymerization initiator solution were added dropwise over 5 hours with stirring.

(Monomer)
Styrene: 94.0 parts by weight Methacrylic acid: 3.3 parts by weight Methyl methacrylate: 2.6 parts by weight t-dodecyl mercaptan: 0.05 parts by weight

(emulsifier)
Sodium dodecylbenzenesulfonate: 0.3 parts by mass Polyoxyethylene nonylphenyl ether: 0.01 parts by mass Ion exchange water: 20.0 parts by mass

(Polymerization initiator)
2% aqueous hydrogen peroxide solution: 40.0 parts by mass 2% aqueous ascorbic acid solution: 40.0 parts by mass

  After dropping, the polymerization reaction was further carried out for 2 hours while maintaining the above temperature, followed by cooling to obtain an aqueous dispersion of styrene / acrylic resin.

  Ion exchange 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 (h).

  For the resin fine particle dispersions (a) to (h) thus obtained, the average particle size of the fine particles in each dispersion was measured using a laser diffraction / scattering particle size distribution measuring apparatus. Further, the acid value and glass transition temperature of the resin used in each dispersion were measured. With respect to the resin fine particle dispersion (h), a part of the dispersion was washed and dried, and the one taken out as a solid content was measured. The acid values of the resin fine particle dispersions (a) and (c) to (h) having sulfonic acid groups were calculated by measuring the amount of S element in each resin using a fluorescent X-ray analyzer (XRF). It is what I asked for. The results are summarized in Table 1 respectively.

[Example 1]
(Example of production of binder resin solution)
The following were charged into a reaction vessel equipped with a stirrer, condenser, thermometer, cooling pipe, nitrogen introduction pipe and stirrer.
-1,2-propanediol: 847 parts by mass-Terephthalic acid dimethyl ester: 861 parts by mass-1,6-hexanedioic acid: 212 parts by mass-Tetrabutoxy titanate (condensation catalyst): 3 parts by mass

  The reaction was carried out for 7 hours at 170 ° C. while distilling off the produced methanol under a nitrogen stream. Next, while gradually raising the temperature to 240 ° C., the reaction was performed for 5 hours while distilling off the produced propylene glycol and water in a nitrogen stream, and the reaction was further carried out under a reduced pressure of 20 mmHg, followed by removal. The resin taken out was cooled to room temperature and then pulverized and granulated to obtain polyester resin 1 (binder resin 1). The Tg of polyester resin 1 was 44 ° C.

  Next, 50 parts by mass of ethyl acetate is put into a sealed container with stirring wings, and 50 parts by mass of the polyester resin 1 is added to the agitation at 100 rpm. The binder resin solution is stirred for 3 days at room temperature. 1 was prepared.

(Production example of release agent dispersion)
・ Carnauba wax (melting point 83 ° C.): 18 parts by mass ・ Ethyl acetate: 82 parts by mass The above was put into a container with a stirring blade and the system was heated to 70 ° C. to dissolve the carnauba wax in ethyl acetate. It was.

  Next, the system was gradually cooled while gently stirring at 100 rpm, and cooled to 30 ° C. over 2 hours to obtain a milky white liquid.

  This solution was put into a heat-resistant container together with 20 parts by mass of 1 mm glass beads, dispersed for 3 hours with a paint shaker, glass beads were removed with a nylon mesh, and wax dispersion 1 was obtained.

(Example of production of colorant dispersion)
-Binder resin 1: 20 parts by mass-Cu phthalocyanine (Pigment Blue 15: 3): 20 parts by mass-Ethyl acetate: 60 parts by mass After sufficiently premixing the above materials in a container, this is kept at 20 ° C or lower. A colorant dispersion 1 was obtained by uniformly dispersing and mixing for about 4 hours using an attritor (manufactured by Mitsui Miike Chemical Industries).

<Granulation process>
-Preparation of oil phase Wax dispersion 1:50 parts by mass (Carnauba WAX solid content: 18%)
Colorant dispersion 1:25 parts by mass (pigment solid content: 20%, resin solid content: 20%)
Binder resin solution 1: 160 parts by mass (resin solid content: 50%)
Ethyl acetate: 15 parts by mass The above solution was put into a container, and an oil phase was prepared by stirring and dispersing at 2000 rpm for 5 minutes with a homodisper (manufactured by Tokushu Kika Kogyo Co., Ltd.).

-Preparation of aqueous phase 390.0 parts by mass of 0.1 mol / liter-sodium phosphate (Na ₃ PO ₄ ) aqueous solution was added to 1152.0 parts by mass of ion-exchanged water, and Claremix (M Technique Co., Ltd.) was added. The mixture was heated to 60 ° C. with stirring. Thereafter, 58.0 parts by mass of 1.0 mol / liter-calcium chloride (CaCl ₂ ) aqueous solution was added and stirring was continued to produce a dispersion stabilizer composed of tricalcium phosphate (Ca ₃ (PO ₄ ) ₂ ). Further, 100 parts by mass of ethyl acetate was added to prepare an aqueous medium.

Emulsification and solvent removal The oil phase is put into the aqueous phase and granulated by stirring for 1 minute at 10,000 rpm in a nitrogen atmosphere at 60 ° C. using CLEARMIX (M Technique). Went.

  Further, the resulting suspension was stirred with a paddle stirring blade at a rotation speed of 150 rotations / minute, and the solvent was removed at 60 ° C. and reduced pressure to 500 mgHg for 5 hours to disperse the core particles. A liquid was obtained.

  The obtained dispersion of core particles was cooled, and the supernatant was removed to adjust the concentration of core particles in the dispersion to 20%. This was designated as core particle dispersion (A).

A part of the dispersion (A) was taken out, added with dilute hydrochloric acid, filtered, washed and dried, and used for measurement of the weight average particle diameter (D4) of the obtained core particles.

The weight average particle diameter (D4) of the core particles was 6.3 μm.

<Adhesion process>
The resin particle dispersion (a) 20.0 mass obtained in Synthesis Example 1 is added to 500.0 mass parts (solid content: 100.0 mass parts) of the core particle dispersion (A) obtained through the granulation step. Parts (solid content: 4.0 parts by mass) were added at a dropping rate of 1.0 part by mass / min.

  Subsequently, stirring was performed at 200 rpm for 30 minutes.

  A part of the dispersion was taken out, filtered, washed, and dried, and observed with a scanning electron microscope (SEM). As a result, it was confirmed that the surface was uniformly covered with resin fine particles.

  Thus, a dispersion liquid (B) in which resin fine particles adhered to the core particle surfaces was obtained.

<Fixing process>
The dispersion liquid (B) to which the resin fine particles adhered, obtained through the adhesion step, was heated to 60 ° C. with stirring at 200 rpm.

  Subsequently, 0.2 mol / liter of dilute hydrochloric acid is dropped into the dispersion (B) at a dropping rate of 1.0 part by mass / min, and dilute hydrochloric acid is dropped until the pH of the dispersion (B) becomes 1.2. Continued. Stirring was further continued for 2 hours to obtain a dispersion (C) in which resin fine particles were fixed.

<Smoothing process>
While stirring the dispersion (C) to which the resin fine particles are fixed, obtained through the fixing step at 200 rpm, 10.0 parts by mass of a 1 mol / liter sodium hydroxide aqueous solution is added to the dispersion (C). The dispersion (C) was adjusted to pH 7.1 by dropping at a dropping rate of / min.

  By stirring for 30 minutes in this state, tricalcium phosphate once dissolved was reprecipitated on the core particles to which the resin fine particles were fixed.

  This dispersion was heated to 70 ° C., which is a temperature equal to or higher than Tg of the resin fine particles, and further stirred for 1 hour.

  The dispersion was cooled to 20 ° C., diluted hydrochloric acid was added until the pH reached 1.5, filtered, washed, and dried to obtain toner particles 1.

<External addition process>
Toner particles 1: Hydrophobic titanium oxide treated with n-C ₄ H ₉ Si (OCH ₃ ) ₃ on 100.0 parts by mass (BET specific surface area: 110 m ² / g): 0.9 parts by mass and hexamethyldi Hydrophobic silica (BET specific surface area of 150 m ^{2 /} g) treated with silicone oil after silazane treatment: 0.7 parts by mass was added and mixed with a Henschel mixer to obtain toner 1.

[Example 2]
In Example 1, resin fine particle dispersion (b) obtained in Synthesis Example 2 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the attaching step 20. Toner 2 was obtained in the same manner as in Example 1 except that 0 part by mass (solid content: 4.0 parts by mass) was used.

Example 3
In Example 1, the toner 3 was obtained in the same manner as in Example 1 except that the smoothing step was omitted, and the dispersion having the resin fine particles fixed thereto was cooled to 20 ° C., filtered, washed and dried at the end of the fixing step. It was.

Example 4
In Example 1, the addition amount of the resin fine particle dispersion (a) is changed from 20.0 parts by mass (solid content: 4.0 parts by mass) to 10.0 parts by mass (solid content: 2.0 parts by mass) in the adhesion step. Toner 4 was obtained in the same manner as in Example 1 except that

Example 5
In Example 1, the addition amount of the resin fine particle dispersion (a) is 20.0 parts by mass (solid content: 4.0 parts by mass) to 40.0 parts by mass (solid content: 8.0 parts by mass) in the attaching step. A toner 5 was obtained in the same manner as in Example 1 except that the addition was changed.

Example 6
In Example 1, resin fine particle dispersion (c): 30 obtained in Synthesis Example 3 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the attaching step: 30 Toner 6 was obtained in the same manner as in Example 1 except that 0.0 part by mass (solid content: 6.0 parts by mass) was used.

Example 7
In Example 1, resin fine particle dispersion (d) obtained in Synthesis Example 4 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the adhesion step: 50 Toner 7 was obtained in the same manner as in Example 1 except that 0.0 part by mass (solid content: 10.0 parts by mass) was used.

Example 8
In Example 1, resin fine particle dispersion (e) obtained in Synthesis Example 5 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the attaching step: 15 Toner 8 was obtained in the same manner as in Example 1 except that 0.0 part by mass (solid content: 3.0 parts by mass) was used.

Example 9
In Example 1, resin fine particle dispersion (f) obtained in Synthesis Example 6 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the adhesion step: 25 Toner 9 was obtained in the same manner as in Example 1 except that 0.0 part by mass (solid content: 5.0 parts by mass) was used.

Example 10
In Example 3, resin fine particle dispersion (g) obtained in Synthesis Example 7 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the adhesion step: 20 0.0 parts by mass (solid content: 4.0 parts by mass) was used, the heating temperature was changed from 60 ° C. to 50 ° C. in the fixing step, and the heating temperature was changed from 70 ° C. to 55 ° C. in the smoothing step. A toner 10 was obtained in the same manner as in Example 3 except that.

Example 11
In Example 3, resin fine particle dispersion (h): 55 obtained in Synthesis Example 8 instead of resin fine particle dispersion (a): 20.0 parts by mass (solid content: 4.0 parts by mass) in the attaching step: 55 Toner 11 was obtained in the same manner as Example 3 except that 0.0 part by mass (solid content: 11.0 parts by mass) was used and the heating temperature was changed from 70 ° C. to 100 ° C. in the smoothing step.

Example 12
In Example 7, the toner 12 was used in the same manner as in Example 7 except that instead of 1: 160 parts by mass of the binder resin solution in the granulation step, 160 parts by mass of the binder resin solution described below was used. Got.

(Example of production of binder resin solution)
The following was put into a reaction vessel equipped with a cooling tube, a nitrogen introducing tube and a stirrer.
-1,3-butanediol 1036 parts by mass-terephthalic acid dimethyl ester 892 parts by mass-1,6-hexanedioic acid 205 parts by mass-tetrabutoxy titanate (condensation catalyst) 3 parts by mass

  The reaction was carried out for 7 hours at 170 ° C. while distilling off the produced methanol under a nitrogen stream. Next, while gradually raising the temperature to 240 ° C., the reaction was performed for 5 hours while distilling off the produced propylene glycol and water in a nitrogen stream, and the reaction was further carried out under a reduced pressure of 20 mmHg, followed by removal. The resin taken out was cooled to room temperature and then pulverized and granulated to obtain polyester resin 2 (binder resin 2). The Tg of polyester resin 2 was 38 ° C.

  Next, 50 parts by mass of ethyl acetate is put into a sealed container with stirring wings, and 50 parts by mass of the polyester resin 2 is added to the mixture while stirring at 100 rpm. The binder resin solution 2 is stirred at room temperature for 3 days. Was prepared.

[Comparative Example 1]
In Example 3, Toner 13 was obtained in the same manner as in Example 3 except that the heating temperature was changed from 60 ° C. to 40 ° C. in the fixing step.

[Comparative Example 2]
In Example 3, Toner 14 was obtained in the same manner as in Example 3 except that the heating temperature was changed from 60 ° C. to 80 ° C. in the fixing step.

  Table 2 summarizes the basic conditions of the fixing process and the smoothing process in Examples 1 to 12 and Comparative Examples 1 and 2.

[Comparative Example 3]
(Preparation of core particles)
Diluted hydrochloric acid was added to the core particle dispersion (A) obtained in the granulation step of Example 1 to adjust the dispersion (A) to pH 1.2, followed by filtration, washing and drying to obtain core particles.

(Production of toner particles)
Resin fine particle dispersion h shown in Table 1: 65.0 parts by mass (solid content: 13.0 parts by mass) is added to 400.0 parts by mass of ion-exchanged water, and 100.0 parts by mass of the core particles are added while stirring. Was gradually added and dispersed uniformly.

  The stearylamine acetate 1 mass% aqueous solution was gradually dripped here under stirring, and also stirred for further 1 hour after that.

  Next, the obtained dispersion was filtered, washed with water and dried to obtain toner particles.

(Production of toner)
The toner particles obtained were externally added in the same manner as in Example 1 to obtain toner 15.

[Comparative Example 4]
(Preparation of core particles)
Diluted hydrochloric acid was added to the core particle dispersion (A) obtained in the granulation step of Example 1 to adjust the dispersion (A) to pH 1.2, followed by filtration, washing and drying to obtain core particles.

(Production of toner particles)
Resin fine particle dispersion h shown in Table 1: 65.0 parts by mass (solid content: 13.0 parts by mass) is added to 400.0 parts by mass of ion-exchanged water, and 100.0 parts by mass of the core particles are added while stirring. Was gradually added and dispersed uniformly.

  To this, 1 mol / liter hydrochloric acid aqueous solution was added to adjust the pH of the dispersion to 1.3, and the mixture was stirred for 1 hour, then the temperature of the dispersion was raised to 60 ° C., and further stirred for 2 hours. A dispersion was obtained.

  Next, the obtained dispersion was cooled, filtered, washed with water and dried to obtain toner particles.

(Production of toner)
The obtained toner particles were externally added in the same manner as in Example 1 to obtain toner 16.

[Comparative Example 5]
In Example 3, a toner 17 was obtained in the same manner as in Example 3 except that the fixing step was performed as follows.

<Fixing process>
The dispersion liquid (B) to which the resin fine particles adhered, obtained through the adhesion step, was heated to 60 ° C. with stirring at 200 rpm. Stirring was further continued for 2 hours, and the dispersion was cooled to 20 ° C., diluted hydrochloric acid was added until the pH reached 1.5, filtered, washed and dried to obtain toner particles 17.

  For each of the toners obtained in Examples 1 to 12 and Comparative Examples 1 to 5, the amount of fine powder (a particle ratio of 0.6 μm or more and 2.0 μm or less as measured by FPIA-3000) was evaluated as a production stability evaluation. The weight average particle diameter (D4) was measured. Moreover, measurement of average circularity, low-temperature fixability, and evaluation of blocking resistance were performed according to the procedures described below. The results are summarized in Table 3.

-Manufacturing stability evaluation-
・ Evaluation criteria of fine powder amount Particle ratio (X) of 0.6 μm or more and 2.0 μm or less when core particles are measured with FPIA-3000 and 0.6 μm or more when each toner particle is measured with FPIA-3000 When taking the ratio (Y / X) of the particle ratio (Y) of 0 μm or less,
A: Y / X is less than 1.25. (Particularly little increase in fine powder)
B: Y / X is 1.25 or more and less than 1.50. (Increase in the amount of fine powder is small)
C: Y / X is 1.50 or more and less than 1.75. (The amount of fine powder increases slightly)
D: Y / X is 1.75 or more. (The amount of fine powder increases)

Evaluation Criteria for Weight Average Particle Size (D4) The ratio (D4b / D4a) of the weight average particle size (D4a) of the core particles and the weight average particle size (D4b) of the toner particles is taken. Judgment criteria are as follows.
A: D4b / D4a is less than 1.05. (Toner particles do not aggregate)
B: D4b / D4a is 1.05 or more and less than 1.10. (Toner particles hardly aggregate)
C: D4b / D4a is 1.10 or more and less than 1.20. (Toner particles slightly aggregate)
D: D4b / D4a is 1.20 or more and less than 1.40. (Toner particles aggregate)
E: D4b / D4a is 1.40 or more. (Toner particles remarkably aggregate)

・ Evaluation criteria for average circularity Judgment criteria are as follows.
A: Average circularity is 0.980 or more.
B: The average circularity is 0.970 or more and less than 0.980.
C: The average circularity is 0.960 or more and less than 0.970.
D: The average circularity is 0.950 or more and less than 0.960.
E: Average circularity is less than 0.950.

-Fixability test method-
Toner and a ferrite carrier surface-coated with a silicone resin (average particle size 42 μm) were mixed to a toner concentration of 6% by mass to prepare a two-component developer. An unfixed toner image (0.6 mg / cm ² ) was formed on the image receiving paper (80 g / m ² ) using a commercially available full color digital copying machine (CLC5000, manufactured by Canon). The fixing unit removed from the copying machine was remodeled so that the fixing temperature could be adjusted, and a fixing test of an unfixed image was performed using this. Under normal temperature and humidity (22 ° C., 60% RH), the process speed was set to 250 mm / s, and the toner image was fixed at each temperature while changing the set temperature from 140 ° C. every 5 ° C.

In the present invention, for the low temperature fixability, a temperature at which no low temperature offset is observed is defined as a low temperature side starting point. The evaluation criteria for the low-temperature fixing performance are as follows.
A: Starting point on the low temperature side is 140 ° C. or lower (low temperature fixing performance is particularly excellent)
B: Low temperature side starting point is 145 ° C. (low temperature fixing performance is good)
C: low temperature side starting point is 150 ° C. (low temperature fixing performance is at a level where there is no problem)
D: Low temperature side starting point is 155 ° C. (low temperature fixing performance is slightly inferior)
E: Starting point on the low temperature side is 160 ° C. or higher (low temperature fixing performance is poor)

-Blocking resistance test method-
10 g of toner is weighed into a 100 ml capacity polycup and placed in a thermostat with an internal temperature of 50 ° C. and left for 8 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: A little aggregate, difficult to loosen D: Many aggregates, not easily loosened E: Not loosened at all

  From the above table, the toner 1 of Example 1 was excellent in low-temperature fixability and excellent in blocking resistance. The amount of fine powder in the toner was extremely small, and aggregation of the toner was suppressed, and the toner could be produced stably.

  Comparing Example 1 and Example 3, it can be seen that the average circularity is increased and the blocking resistance is improved by passing through the smoothing step.

  Moreover, from the results of Example 1 and Example 4, it can be seen that the blocking resistance decreases when the amount of resin fine particles used in the outer shell decreases. When the cross section of each toner was observed with a transmission electron microscope (TEM), the toner of Example 4 was found to have a slight defect that was not covered with the outer shell, but the toner of Example 1 was apparently It was confirmed that it was completely covered.

  When fixed at Tg or less of the core particle as in Comparative Example 1, since the resin fine particles are not fixed to the core particle, the amount of fine powder increases and the blocking resistance is remarkably lowered.

  When the resin particles are fixed at Tg or higher as in Comparative Example 2, the core particles cannot be maintained in a dispersed state and agglomeration occurs.

As in Comparative Examples 3, 4, and 5, when the resin fine particles are adhered and fixed in a process different from that of the present invention, it is difficult to form a uniform and dense resin fine particle layer. Inferior in performance.

Claims (6)

A binder resin, a colorant and contains at least a solvent capable dissolving the binder resin, the mixture in which the colorant is dispersed in the binder resin dissolved in the solvent, water-based containing a dispersion stabilizer dispersed in a medium to form a dissolved resin droplets, the dissolved resin liquid solvent was removed from the droplets, the core particle dispersion prepared by dispersing core particles (a) obtained Ru Engineering as (a),
To the core particle protégé dispersion liquid (A), the dispersion is the same as polarity the core particles to stabilizing agent, and then adding a resin fine particles having a higher than the binder resin Tg, the resin particles wherein the dispersion stabilizer as engineering to obtain a dispersion (B) having agent was allowed to adhere to the surface of the core particle while interposing particles (B),
The dispersion (B) temperature than Tg of the binder resin, and while holding Chi below Tg of the resin particles, the pH of the dispersion, the dispersion stabilizer is adjusted to a pH region exhibit solubility by removing the dispersion stabilizer by dissolving the dispersion stabilizer to obtain a dispersion (C) with said resin fine particles are fixed on the surface of the core particles particles (C)
A method for producing toner, wherein toner particles are produced through at least the process. After enough before climate (C), the pH of the dispersion (C), adjusted to pH region in which the dispersion stabilizer is reprecipitated, then smoothed to a heat treatment at a temperature higher than Tg of the resin particles The toner production method according to claim 1, further comprising a step. Method for producing a toner according to claim 1 or 2, characterized in that the Tg of the binder resin is 20 to 50 ° C.. The Tg of the resin particles, method for producing a toner according to any one of claims 1 to 3, characterized in that a 55 to 90 ° C.. The average particle diameter of the resin fine particles, method for producing a toner according to any one of claims 1 to 4, characterized in that in the range of 10 to 100 nm. In more before climate (B), the amount sticking of the resin fine particles relative to the core particles, in any one of claims 1 to 5, characterized in that a 1.0 to 10.0 wt% A method for producing the toner according to the description.