JP2008040285A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that when a softening point and a glass transition temperature of a polyester resin are lowered, the content of volatile organic compounds (VOC) included in the polyester resin increases, and when a toner containing a polyester resin having a low softening point and a low glass transition temperature as a raw material is fixed, the amount of VOC also increases. <P>SOLUTION: A thermoplastic polyester resin having a softening point of 90 to 100°C, a glass transition point of 35 to 50°C and the content of volatile organic compounds of 170 ppm or less is used as a resin component of the toner. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner that is suitably used for a copying machine, a printer, a fax machine, and the like, and further used for a toner jet printer or the like.

In image output devices such as electrophotographic copiers, printers, fax machines, etc., the resolution of printed images is improved, the gradation is improved, the amount of waste toner is reduced, and the energy consumption is reduced by lowering the fixing temperature. In view of demands for improving image characteristics in full-color images, toner particles used for image formation use a polymerization method, an emulsification dispersion method, or the like instead of a pulverization method in which small particle size particles are produced by pulverization.
In the toner manufacturing method by the polymerization method, since the binder resin is limited to a vinyl polymer capable of radical polymerization, the toner cannot be manufactured using a polyester resin as a raw material. In addition, the polymerization method has a problem that volatile organic compounds composed of unreacted monomers remain.
On the other hand, an emulsification dispersion method has been proposed in which particles are produced after a mixture of a binder resin and a colorant is mixed with an aqueous medium and emulsified. The emulsion dispersion method is a method in which a mixture of a binder resin and a colorant is mixed with an aqueous medium and emulsified to obtain toner particles. Therefore, since a mixed solvent is used, it is difficult to recover and reuse the solvent. In addition, there is a problem that the yield of the toner is reduced because fine particles are generated.

Therefore, a method has been proposed in which a polyester resin or the like is emulsified and dispersed as a binder resin, and then the obtained fine particles are aggregated and further heated and fused to form an aggregate. Therefore, there is a problem that it is necessary to stir at high temperature for a long time.
In addition, a method has been proposed in which fine particles are produced by emulsification and dispersion, and then the step of aggregating the fine particles and the step of fusing the agglomerated fine particles are performed at the same time. They are united by collisions between particles under force. For this reason, the coalescence tends to be non-uniform, and the generation of aggregates is inevitable. On the other hand, since emulsification and dispersion are performed under shearing force, and then the particles are aggregated under the same conditions, crushing occurs at the same time as coalescence, so the generation of fine particles increases, and the particle size distribution of the toner particles to be generated is increased. There was a limit to narrowing.

In contrast to these methods, there is a toner production method called a phase inversion emulsification method in which a polyester resin, wax, colorant and the like are dissolved or dispersed in an organic solution, and the obtained oil phase component is dispersed and granulated in an aqueous medium. Proposed. In this method, in order to reduce emulsification loss and obtain a sharp particle size distribution, an oil phase component is emulsified in an aqueous medium to form fine particles of the mixture in the aqueous medium, followed by dispersion stabilization. A toner is manufactured through a coalescing step in which the fine particles are coalesced by adding an agent and sequentially adding an electrolyte (see, for example, Patent Documents 1 and 2). The toner particles obtained by this production method can achieve low-temperature fixing of the toner by using a polyester resin having a low softening point and glass transition temperature, but if the softening point and glass transition temperature of the polyester resin are lowered, VOCs generated when fixing toners made from polyester resin, which has a high softening point and low glass transition temperature, and contains a large amount of volatile organic compounds (VOC) such as residual unreacted monomers contained in the polyester resin There was a problem that the amount also increased.
JP 2003-122051 A JP 2004-198598 A

  In the present invention, when the softening point and glass transition temperature of the polyester resin are lowered, the content of the volatile organic compound (VOC) contained in the polyester resin is increased, and the polyester resin having a low softening point and glass transition temperature is used as a raw material. An object of the present invention is to solve the problem that the amount of VOC generated when fixing toner is also increased.

The present invention is characterized in that a polyester resin having a softening point of 90 to 100 ° C., a glass transition temperature of 35 to 50 ° C. and a volatile organic compound content of 170 ppm or less is used as the resin component.
The present invention is also an electrostatic image developing toner, characterized in that the thermoplastic polyester resin is contained in an amount of 30% by mass or more based on the resin component.
The toner of the present invention comprises a step of obtaining a colored resin solution by dissolving or dispersing the binder resin, wax and colorant containing the thermoplastic polyester resin in an organic solvent, and adding a basic compound and water to the colored resin solution. Step of emulsifying the colored resin solution in the aqueous medium sequentially, adding the electrolyte aqueous solution to the prepared emulsion suspension, and combining the dispersoids in the emulsion suspension to produce colored resin fine particles The particles are produced through a step of forming particles, removing an organic solvent under reduced pressure, and then separating, washing, and drying the colored resin fine particles from the aqueous medium.
The present invention is characterized in that the toner has a core-shell structure.
The present invention is characterized in that the toner has a volatile organic compound content of 50 ppm or less.
According to the present invention, a thermoplastic polyester toner having a low softening point and glass transition temperature and a low VOC content is provided.

The present invention will be described in detail below. The polyester resin of the present invention is produced by reacting a divalent basic acid with a dihydric alcohol.
Examples of the divalent basic acid compound include phthalic anhydride, terephthalic acid, isophthalic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, cyclohexanedicarboxylic acid, and succinic acid. , Dicarboxylic acids such as malonic acid, glutaric acid, azelaic acid and sebacic acid or derivatives thereof.

  Examples of the divalent aliphatic alcohol include 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, neopentyl glycol, butanediol, pentanediol, and hexanediol. Diols such as polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer diol, polycaprocactone diol It is done.

Usually, when a polyester resin is synthesized, a dehydration condensation reaction or a transesterification reaction is performed in the presence of a catalyst using raw material components.
As a catalyst for performing the above reaction, for example, tetrabutyl titanate, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid and the like are appropriately used. In the reaction, after the raw materials are charged into the reaction kettle, the reaction is heated and the reaction proceeds at normal pressure or under pressure. When the resin reactant becomes transparent (a state in which about 90% of the reaction has progressed), the pressure is reduced and the reaction is continued. Proceed to obtain a resin with the desired viscosity. The resin of the present invention is characterized in that the use of the catalyst is suppressed as much as possible and the progress of the reaction after depressurization is made as slow as possible, and the depressurization reaction time at the time of resin production is made as long as possible to remove the residual monomer of the resin and reduce the VOC. To do.

  The glass transition temperature of the polyester resin of this invention is 35-50 degreeC, and it is especially preferable that it is 40-50 degreeC. When the glass transition temperature of the polyester resin is lower than 35 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. Further, if the glass transition temperature of the polyester resin is higher than 50 ° C., it is not preferable because the low toner fixing property of the toner is lowered.

  The softening point of the polyester resin of the present invention is 90 ° C to 100 ° C, and particularly preferably 90 ° C to 95 ° C. This is because when the softening point of the polyester resin is less than 90 ° C., the toner tends to cause agglomeration phenomenon, which is likely to cause trouble during storage or printing. When the softening point of the polyester resin exceeds 100 ° C. This is because the toner fixing property is likely to deteriorate.

  The VOC content of the polyester resin of the present invention is 170 ppm or less, and more preferably 150 ppm or less. When the VOC content of the polyester resin exceeds 180 ppm, the VOC content of the toner also increases, and as a result, the VOC amount generated at the time of fixing the toner increases.

The softening point of the polyester resin is a T1 / 2 temperature measured using a constant load extrusion type capillary rheometer (Flow Tester CFT-500 manufactured by Shimadzu Corporation). The measurement is performed under the conditions of a piston cross-sectional area of 1 cm ² , a cylinder pressure of 0.98 MPa, a die hole length of 1 mm, a die hole diameter of 1 mm, a measurement start temperature of 50 ° C., a temperature increase rate of 6 ° C./min, and a sample mass of 1.5 g. .

  Moreover, the measurement of the glass transition temperature of a polyester resin is measured using DSC (Shimadzu DSC-60A). 20 mg of sample is put in an aluminum crimp cell, heated to 180 ° C. at a heating rate of 10 ° C./min, cooled to room temperature at a cooling rate of 10 ° C./min from 180 ° C., and again to 180 ° C. at a heating rate of 10 ° C./min. The temperature rise and the second run value are Tg.

  The volatile organic compound content (VOC) was measured by gas chromatography (Shimadzu GC-17A). Weigh 500 mg of sample into a 27 ml headspace viable and plug. The vial is heated at 200 ° C. for 5 minutes. Take out the heated vial, aspirate 0.8 ml of gas with a microsyringe from the upper part, inject it into gas chromatography, perform measurement, cut 300 or less of the resulting area, convert it to toluene, and calculate the TVOC (Total VOC) value. Obtained. Gas chromatography measurement conditions were as follows: Column (Shimadzu CBP10-S50-050: Length 50m Inner diameter 0.33mm, Film thickness 0.5μm), Column inlet pressure (64kPa), Split ratio (1:40), Vaporization chamber temperature (250 ° C) , Detector temperature (270 ° C.), detector (FID), temperature program (measurement temperature: 50 to 240 ° C. hold at 50 ° C. for 7 min, temperature rise at 3 ° C./min, hold at 240 ° C. for 15 min).

Next, the toner of the present invention will be described in detail. The toner production method of the present invention comprises the following steps.
(1) Colored resin solution preparation step In this step, a colored resin solution is obtained by dissolving or dispersing the binder resin, wax and colorant containing the polyester resin of the present invention in an organic solvent.
(2) Emulsification step In this step, a basic compound and water are sequentially added to the colored resin solution to emulsify the colored resin solution in an aqueous medium.
(3) Coalescence Step At least one operation of forming particles by adding colored electrolyte solution to the prepared emulsion suspension and coalescing the dispersoid in the emulsion suspension to form colored resin fine particles. It is a process to be performed.
(4) Separation / Drying Step In this step, after removing the organic solvent under reduced pressure, the colored resin fine particles are separated from the aqueous medium, washed and dried to form toner base particles.

  After the coalescence process, before the separation / drying process, an emulsion suspension of the shell-forming resin and the dispersion containing the colored resin fine particles obtained in the coalescence process are mixed, and an aqueous electrolyte solution is added to the core / shell structure. You may implement the shell formation process which forms the particle | grains which have.

In the colored resin solution preparation step, first, a binder resin containing the polyester resin of the present invention, a wax and a colorant are introduced into an organic solvent and dissolved or dispersed.
The binder resin, wax and colorant containing the polyester resin of the present invention are preferably dissolved or dispersed in an organic solvent with a high-speed stirrer. In this case, the colorant may be pre-dispersed in advance to prepare a master kneading chip, and finely dispersed below the toner particle diameter to be prepared. The wax may also be mixed after preparing the master kneading chip in advance. Alternatively, a wax master solution finely dispersed below the toner particle size by wet dispersion using media may be used.

In the colored resin solution preparation step, Desper (Asada Iron Works Co., Ltd .: Despa Tsubasa), T.W. K. A high-speed stirrer such as a homomixer (Primix Co., Ltd .: TK homodisper type 2.5 blade) can be used. The blade tip speed at this time is preferably 4 to 30 m / s, and more preferably 8 to 25 m / s. By using the high-speed stirrer, the binder resin can be efficiently dissolved in the organic solvent, and uniform fine dispersion of the colorant in the binder resin solution can be achieved. That is, the state of the colorant finely dispersed in advance can be maintained in the binder resin solution by stirring at high speed.
When the blade tip speed is lower than 4 m / s, fine dispersion of the colorant, wax, etc. in the colored resin solution becomes insufficient. Or, the undissolved portion of the resin remains unfavorable. On the other hand, if it is higher than 30 m / s, heat generation due to shearing becomes large, and it is not preferable because uniform stirring becomes difficult in combination with volatilization of the solvent. Moreover, the temperature in the case of melt | dissolving or disperse | distributing has the preferable range of 20-60 degreeC, and the range of 30-50 degreeC is more preferable.

As an organic solvent, the thing whose solubility with respect to water in 25 degreeC is 0.1-30 mass% is preferable, and what is 0.1-25 mass% is more preferable. The boiling point at normal pressure is preferably lower than the boiling point of water. Further, the organic solvent is preferably a solvent having a low boiling point because it dissolves the binder resin and can be easily removed in a subsequent process.
As such an organic solvent, for example, ketones such as methyl ethyl ketone and methyl isopropyl ketone, and esters such as ethyl acetate and isopropyl acetate are used. Two or more organic solvents can be mixed and used, but from the viewpoint of solvent recovery, it is preferable to use the same type of solvent alone. Of these, methyl ethyl ketone is preferable.

In the step of preparing the colored resin solution, it is preferable to add an emulsifier.
In order for the emulsifier to function in the coalescing step, it is necessary to have a characteristic capable of maintaining dispersion stability even in the presence of an electrolyte added later. Examples of emulsifiers having such properties include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene Examples include nonionic emulsifiers such as oxyethylene sorbitan fatty acid esters and various pluronics, alkyl sulfate ester salt type and alkyl sulfonate salt type anionic emulsifiers, and quaternary ammonium salt type cationic emulsifiers. Moreover, an alkylbenzene sulfonate type emulsifier and a linear alkyl benzene sulfonic acid type emulsifier can be mentioned.
The above-mentioned emulsifiers may be used alone or in combination of two or more. That is, in the production method of the present invention, it is possible to prevent non-uniform coalescence by adding an electrolyte in the presence of an emulsifier. Thereby, a preferable particle size distribution is obtained.

  The amount of the emulsifier to be used is preferably 0.1 to 3.0% by mass, more preferably 0.3 to 2.0% by mass, and more preferably 0.3 to 1.5% by mass with respect to the solid content. It is particularly preferred that When the amount of the emulsifier to be used is less than 0.1% by mass with respect to the solid content, the desired effect of preventing the generation of coarse particles cannot be obtained. Further, when the amount of the emulsifier used is more than 3.0% by mass with respect to the solid content, the coalescence of the dispersoid in the emulsified suspension does not sufficiently proceed even if the amount of the electrolyte is increased, and the predetermined amount. As a result, fine particles remain and the yield decreases.

Next, in the emulsification step, a basic compound and water are sequentially added to the colored resin solution to emulsify the colored resin solution in the aqueous medium. Here, it is preferable to gradually add water to the colored resin solution in which the carboxyl group of the polyester resin which is the resin component of the toner of the present invention is neutralized with the basic compound. By neutralizing the carboxyl group, the hydrophilicity of the polyester resin, which is the resin component of the toner of the present invention, is improved, and the affinity with water is improved.
The added water is hydrated to the carboxyl group portion of the polyester resin, and the binder resin containing the polyester resin of the present invention is finely dispersed in combination with the stirring effect. On the other hand, the viscosity of the system containing the colored resin solution increases with the addition of water. When a certain amount of water is added, there is a point that the viscosity decreases, which is called a so-called phase inversion point. The viscosity increases until just before this, and the viscosity reaches the maximum value. The increase in viscosity correlates with the addition amount of the basic compound, and the increase in viscosity increases as the addition amount increases.

  On the other hand, the amount of the basic compound affects not only the emulsification step but also the uniformity and speed when the colored resin fine particles are produced in the coalescence step described later. The range of 1-3 equivalent is preferable with respect to the carboxyl group of binder resin. Moreover, the range of 1-2 equivalent is still more preferable. By adding in excess of the amount required to neutralize all the carboxyl groups of the binder resin in this way, it is possible to prevent the formation of irregularly shaped particles in the coalescing step, and toner particles The particle size distribution can be made narrow.

  The ratio of the organic solvent to the total amount of the organic solvent and water after the emulsification step is preferably in the range of 20 to 35% by mass, and more preferably in the range of 20 to 30% by mass. As described above, the amount of water up to the phase inversion point decreases as the amount of organic solvent in the colored resin solution preparation step decreases, and increases as the amount of basic compound increases. At the phase inversion point, the viscosity of the emulsified suspension may be high, and the colored resin solution may not be completely finely dispersed in the aqueous medium. Therefore, it is preferable to add water. The ratio of water after dripping water in the emulsified suspension obtained in this step (the total amount of water used for emulsification, water from emulsion wax, water added with neutralizing base, etc.) and the organic solvent is 50:50 to 80:20 is preferable, and 60:40 to 80:20 is more preferable.

  The acid value of the polyester resin that is the resin component of the toner of the present invention is not particularly limited, but is preferably 3 to 30 KOHmg / g, and more preferably 5 to 20 KOHmg / g. When the acid value of the polyester resin, which is the resin component of the toner of the present invention, is less than 3, the toner of the present invention cannot be produced. On the other hand, if the acid value of the polyester resin, which is the resin component of the toner of the present invention, is greater than 30, the charge amount under the toner use environment of the present invention is not stable.

  Examples of the basic compound for neutralization include inorganic bases such as sodium hydroxide, potassium hydroxide, and ammonia, and organic bases such as diethylamine, triethylamine, and isopropylamine. In particular, an aqueous solution of an inorganic base such as sodium hydroxide, potassium hydroxide or ammonia is preferred.

  The emulsified suspension produced by the above-described method exists in a state where the colored resin solution is emulsified and dispersed in an aqueous medium. The state varies depending on the type of organic solvent, the amount used, the acid value of the binder resin, the amount of basic compound used, the stirring conditions, etc. It is preferable to be emulsified and dispersed with an average particle size of less than 1 μm. Such a state is preferable because the stability of the emulsified suspension, the unitary stability in the subsequent steps, the particle size distribution of the colored resin fine particles, and the like are improved.

Next, the coalescence process will be described. By adding an electrolyte to the obtained emulsion suspension while stirring, the dispersoid in the emulsion suspension is salted out or destabilized. At this time, by stirring the emulsified suspension, the dispersoids collide with each other to be integrated. Finely dispersed resin oil droplets, wax dispersoids, colorant dispersoids and the like that are dispersoids are integrated into colored resin fine particles. Thereafter, the colored resin fine particles collide with each other, coalescence proceeds, and larger colored resin fine particles are generated. Thereby, the colored resin fine particles become particles having almost the same composition. By controlling the coalescing speed, colored resin fine particles having a desired size and particle size distribution can be obtained.
These colored resin fine particles are in a kind of swollen state containing an organic solvent, and so-called coalescence occurs in which fusion occurs simultaneously with the collision. For this reason, the colored resin fine particles after solvent removal in the subsequent step have sufficient strength, and it is not necessary to provide a separate fusion step by heating.

  Examples of the electrolyte used here include sodium sulfate, ammonium sulfate, potassium sulfate, magnesium sulfate, sodium phosphate, sodium dihydrogen phosphate, sodium chloride, potassium chloride, ammonium chloride, calcium chloride, sodium acetate, sodium bicarbonate, etc. Organic and inorganic water-soluble salts can be effectively used as the electrolyte. These electrolytes to be added for unity may be used alone or in combination of two or more kinds. Among them, monovalent cation sulfates such as sodium sulfate and ammonium sulfate are preferable for promoting uniform coalescence.

Moreover, the colored resin fine particles obtained are swollen by a solvent, and it is preferable that the particles collide with each other by stirring with a low shearing force to advance the coalescence. Unlike the so-called dissolution suspension method, it is not necessary to finely disperse oil droplets by high-speed stirring, so that no fine powder is generated and the toner particle size distribution can be narrow and good.
It is preferable to select an agitation speed so as to obtain a low shearing force in such a range that only coalescence in which the colored resin fine particles are not split proceeds.

In order to promote uniform coalescence, agitation conditions at the same time are important. For example, anchor blade, turbine blade, fowler blade, full zone blade, max blend blade (registered trademark, manufactured by Sumitomo Heavy Industries, Ltd.), half moon blade, etc. Is used. Among them, it is preferable to use a large wing that is excellent in uniform mixing properties even at a low rotation, such as a Max blend wing or a full zone wing.
The peripheral speed of the stirring blade for generating uniform colored resin fine particles is preferably 0.2 to 10 m / s, and more preferably stirring at a low shear of 0.2 to 8 m / s. In particular, 0.2 to 6 m / s is preferable. If the peripheral speed of the stirring blade is higher than 10 m / s, fine particles remain, which is not preferable. On the other hand, if the peripheral speed is less than 0.2 m / s, stirring is not uniform and coarse particles are generated, which is not preferable. Under the above-described conditions, coalescence proceeds only by collision between the colored resin fine particles, and the colored resin fine particles are not dissociated and dispersed. In particular, in the coalescing process, the generation of fine particles is small and a narrow particle size distribution can be obtained.
That is, it is preferable to stir with a high-speed stirrer such as a desper in the colored resin solution preparation step and the emulsification step, and a large blade that can be uniformly mixed at a low speed such as a max blend blade is suitable in the coalescence step. For this reason, it is preferable to carry out the coalescing step by transferring the emulsified suspension obtained in the emulsifying step to another container attached to the large blade.

Moreover, 0.5-15 mass% is preferable with respect to solid content, and, as for the quantity of the electrolyte to be used, it is more preferable that it is 1-12 mass%, and it is especially preferable that it is 1-6 mass%. When the amount of the electrolyte is less than 0.5% by mass, coalescence does not proceed sufficiently. If the amount is more than 15% by mass, it is not preferable because a large amount of stop water is required in the subsequent process, and it takes time for washing and drying.
Moreover, 1-15 mass% is preferable and, as for the density | concentration of electrolyte solution, it is more preferable that it is 3-10 mass%. If the amount is less than 1% by mass, the effect of the electrolyte is not sufficiently exhibited, and a large amount of electrolyte is required for salting out and coalescence. Or, colored resin fine particles may not be generated. On the other hand, if it is higher than 15% by mass, unevenness is likely to occur in the system, and in particular, aggregates and coarse particles are likely to be generated during the formation of colored resin fine particles in the initial stage of coalescence, which is not preferable.

  In the coalescence process, when adding the aqueous electrolyte solution, it is preferable to increase the stirring speed in order to mix the electrolyte uniformly and quickly in the system. The temporary temperature is preferably in the range of 10 to 50 ° C. More preferably, it exists in the range of 20-40 degreeC, and it is especially preferable that it is 20-35 degreeC. When the temperature is lower than 10 ° C., it is difficult to perform coalescence, which is not preferable. On the other hand, when the temperature is higher than 50 ° C., the coalescence speed is increased, and aggregates and coarse particles are easily generated, which is not preferable. In the production method of the present invention, for example, colored resin fine particles can be produced by coalescence under a low temperature condition of 20 to 40 ° C.

Next, a shell formation step for forming particles having a core / shell structure may be performed before the separation / drying step. By coating the core colored resin fine particles with a resin having a glass transition temperature higher than the glass transition temperature of the resin constituting the colored resin fine particles, the toner has both low-temperature fixability and heat-resistant storage stability, and the surface The development durability can be increased by preventing the wax from being exposed to the surface.
The emulsion suspension of the shell-forming resin used in the shell-forming step may be only the resin from which the colorant and wax have been removed, or may contain a charge control agent and the like. The method for preparing the emulsified suspension of the shell-forming resin may be prepared by any method as long as the resin for the shell is emulsified, but from the compatibility with the colored resin fine particles, the colored resin solution preparation step And it is preferable to prepare by the same operation as the emulsification step. That is, an emulsifier, a basic compound, and water are sequentially added to a resin solution obtained by dissolving a shell-forming resin in an organic solvent to prepare an emulsion suspension in which the shell-forming resin is emulsified in an aqueous medium. To do.

The shell resin oil droplets in the shell emulsified suspension are preferably submicron in size. These oil droplets adhere to the surface of the colored resin fine particles to form a shell structure. The size ratio between the colored resin fine particles and the shell resin oil droplets is about 30: 1 to 50: 1, and the number ratio is 1: 5, assuming that the shell ratio in the toner is about 5% by mass, although it depends on the amount of shell input. 150 to 1: 250. Therefore, when the shell emulsification suspension is added and stirred and dispersed, there are about 150 to 250 shell resin oil droplets around one colored resin fine particle, and when stirring is performed under the coalescence conditions, The colored resin fine particles first collide with and adhere to the shell resin oil droplets. At this time, coalescence proceeds due to the effect of the electrolyte in the colored resin particle dispersion.
On the other hand, when there are too many shell resin oil droplets, many of the oil droplets collide with each other and remain without adhering to the colored resin fine particles, or even if adhering to the colored resin fine particles, they remain as large particles. The structure tends to be non-uniform and easily peeled off.

Next, an aqueous electrolyte solution is further added and stirred. The stirring conditions and the electrolyte used are the same as in the coalescing step. By adding the electrolyte aqueous solution, the shell-forming resin fine particles are further destabilized, and the shell-forming resin oil droplets remaining in the liquid that cannot be adhered in the previous stage are increased, and the surface of the colored resin fine particles is fixed. A shell is formed.
In order to fix the shell-forming resin fine particles to the surface of the colored resin fine particles, it is preferable to add a basic compound before adding the shell emulsion suspension. By adding the basic compound, there is an effect that the colored resin fine particles are further swollen and the shell-forming resin fine particles are easily fixed.

  In the shell forming step, the colored resin fine particles swollen by the organic solvent and the shell forming resin oil droplets collide with each other to grow the particles. Therefore, the shell can be formed even if it is lower than the glass transition temperature of the shell-forming resin. Depending on the glass transition temperature of the shell-forming resin, a shell can be formed even at 30 ° C. or lower. Therefore, heating is not required in the shell forming step, and naturally, cooling after heating is not required, so that a great deal of energy is not consumed and temperature management becomes simple.

  Particle growth can be expressed by creating a blotted particle growth curve from time and particle size to maintain a nearly constant growth rate under certain conditions. As a result, the arrival time of the target particle diameter can be estimated from the curve. Moreover, it is preferable to stop shell formation by adding water. The amount of water when the shell formation is stopped is related to the amount of the organic solvent added during the preparation of the colored resin solution and the emulsion suspension of the shell forming resin. As the amount of the organic solvent relative to the solid content is larger, the amount of the organic solvent taken into the particles is relatively larger, so that it is necessary to suppress swelling with a larger amount of water.

  If necessary, the colored resin fine particle dispersion formed into a shell is desolvated and proceeds to the next step. The solvent removal is preferably carried out with stirring under reduced pressure in order to carry out quickly under low temperature conditions. In removing the solvent, an antifoaming agent is preferably added. The antifoaming agent is preferably in the form of a silicone emulsion. Examples of silicone-based antifoaming agents include BY22-517, SH5503, SM5572F, BY28-503 (manufactured by Toray Dow Corning Silicone), KM75, KM89, KM98, KS604, KS538 (manufactured by Shin-Etsu Chemical Co., Ltd.), and the like. . Of these, BY22-517 is preferred as having little influence on physical properties and a high defoaming effect. The amount of the antifoaming agent is preferably 30 to 100 ppm with respect to the solid content.

The toner particles of the present invention are characterized in that a colorant or wax is encapsulated in a binder resin, and the colorant or wax is encapsulated in the particle by observation with a transmission electron microscope or the like. It can be confirmed that the particles are almost uniformly dispersed.
The shape of the toner particles is determined by a particle image analyzer (Sysmex flow type particle image analyzer FPIA-1000) or the like, and the degree of circularity is the circumference of a circle corresponding to the projected area of the observed particle image. It is expressed as an average circularity which is an average value of numerical values expressed as a ratio to the perimeter of the projected image of the observed particle.
Regarding the shape of the toner particles, the average circularity is preferably 0.95 or more, more preferably 0.96 or more, and further preferably 0.97 or more. This is because powder fluidity is improved and transfer efficiency is improved by making the average circularity into a substantially spherical shape or a spherical shape with 0.97 or more.

  Next, in the separation / drying step, the colored resin fine particles are separated, washed and dehydrated. Separation and dehydration from the aqueous medium can be performed by a separation means such as a centrifugal separator, a filter press, or a belt filter. Washing is performed by stirring and solidifying the solid content using ion exchange water or the like and repeating dehydration. Next, toner particles can be obtained by drying the particles. Drying is a fluidized bed dryer such as a ribocorn dryer (Okawara Seisakusho), a mixed vacuum dryer such as Nauta Mixer (Hosokawa Micron), a fluidized bed dryer (Okawara Seisakusho), or a vibrating fluidized bed dryer (central processing machine). However, it is not limited to these dryers.

Regarding the particle size distribution of the toner, 50% volume particle size / 50% number particle size (Dv / Dn) is 1.20 or less as measured by Beckman Coulter Multisizer II type (aperture tube diameter: 100 μm). Is preferable, and it is more preferable that it is 1.15 or less. This is because it is easy to obtain a good image when it is 1.10 or less.
The toner preferably has a 50% volume average particle diameter (Dv50) of 3 to 8 μm, and the use of a toner having a small particle diameter not only improves resolution and gradation, but also forms a printed image. The thickness of the layer is reduced, the amount of heat required for fixing can be reduced, and at the same time, the toner consumption can be reduced.

  As the binder resin of the toner of the present invention, a resin other than the polyester resin of the present invention may be mixed with the polyester resin of the present invention. The binder resin and the shell forming resin other than the polyester resin of the present invention are not particularly limited, but are preferably a cross-linked polyester resin or a linear polyester resin, and a compound selected from the following raw materials is reacted. Can be obtained.

The crosslinked polyester is preferably produced by reacting a divalent basic acid or derivative thereof, a divalent alcohol, and a polyvalent compound as a crosslinking agent. In particular, it is preferable to produce by reacting a divalent basic acid or a derivative thereof, a divalent aliphatic polyhydric alcohol, and a polyvalent epoxy compound as a crosslinking agent. The linear polyester resin is produced by reacting a divalent basic acid with a dihydric alcohol.
Examples of the divalent basic acid compound and divalent aliphatic alcohol used when producing the crosslinked polyester resin and the linear polyester resin include those used when producing the polyester resin of the present invention.

  By using an aliphatic alcohol as a raw material for the cross-linked polyester resin and the linear polyester resin, the compatibility with waxes is improved, and offset resistance is preferably improved. Moreover, fixing property at low temperature is improved by softening the polyester main chain. When producing a crosslinked polyester resin, a polyvalent epoxy compound is further used as a crosslinking agent. Examples of such compounds include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, ethylene glycol diglycidyl ether, hydroquinone diglycidyl ether, N, N-diglycidyl aniline lysine triglycidyl ester, Trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetrakis 1,1,2,2 (P-hydroxyphenyl) ethane tetraglycidyl ether, cresol novolac epoxy resin, phenol novolac epoxy resin A polymer or copolymer of an epoxy group-containing vinyl compound, an epoxidized resorcinol-acetone condensate, a partial epoxy Polybutadiene, polymers of vinyl compounds having an epoxy group, or a copolymer, such as semi-drying or drying fatty acid ester epoxy compound. Among the above compounds, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, glycerin / triglycidyl ether, trimethylolpropane triglycidyl ether, trimethylol Ethanetriglycidyl ether and pentaerythritol tetraglycidyl ether are more preferably used.

  Specific examples of bisphenol A type epoxy resins include Dainippon Ink Chemical Co., Ltd. Epicron 850, Epicron 1050, Epicron 2055, Epicron 3050, and the like. Epicron 830, Epicron 520, etc. manufactured by Dainippon Ink & Chemicals, Inc. as examples of orthocresol novolac type epoxy resins, N-660, N-665, N-667, N-670, N- 673, N-680, N-690, N-695, etc. are examples of phenol novolac type epoxy resins. Epiklon N-740, N-770, N-775, N-manufactured by Dainippon Ink & Chemicals, Inc. 865 etc. As a polymer or copolymer of a vinyl compound having an epoxy group, Examples thereof include a homopolymer of glycidyl (meth) acrylate, an acrylic copolymer, and a copolymer with styrene.

Moreover, the epoxy compound mentioned above can also be used in combination of 2 or more types, Furthermore, the mono epoxy compound described below can also be used together as a modifier | denaturant of resin. Examples of the monoepoxy compound that can be used at the same time include phenyl glycidyl ether, alkylphenyl glycidyl ether, alkyl glycidyl ether, alkyl glycidyl ester, glycidyl ether of alkylphenol alkylene oxide adduct, α-olefin oxide, monoepoxy fatty acid alkyl ester, etc. Is mentioned.
By using these monoepoxy compounds in combination, fixability and resistance to offset at high temperatures are improved. Among these, alkyl glycidyl esters are particularly preferably used. A specific example is Cardura E (Neodecanoic acid glycidyl ester manufactured by Shell Japan).

The cross-linked polyester resin and the linear polyester resin can be obtained, for example, by performing a dehydration condensation reaction or a transesterification reaction in the presence of a catalyst using the raw material components described above.
As the catalyst for performing the above reaction, for example, tetrabutyl titanate, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, paratoluenesulfonic acid, and the like can be used as appropriate.

  The polyester resin of the present invention needs to be contained in an amount of 30% by mass or more based on the resin component of the toner of the present invention. When the content of the polyester resin of the present invention is less than 30% by mass relative to the resin component of the toner, the VOC content of the toner increases.

  When a mixture of a crosslinked polyester resin and a linear polyester resin is used as the resin component of the toner of the present invention, the mixing ratio is not particularly limited, but (mass of the crosslinked polyester resin) / (linear polyester) (Mass of resin) = 5/95 to 60/40 is preferable, 10/90 to 40/60 is more preferable, and 20/80 to 40/60 is particularly preferable. When the ratio of the cross-linked polyester resin is less than 5% by mass, the hot offset resistance, the coalescence speed, and the dispersibility of wax, colorant and the like are not preferable. On the other hand, when the ratio of the cross-linked polyester resin is more than 60% by mass, the melt viscosity (T1 / 2 temperature) increases and the low-temperature fixability decreases, which is not preferable.

  The glass transition temperature of the crosslinkable polyester resin other than the polyester resin of the present invention is not particularly limited, but is preferably 40 to 90 ° C, and particularly preferably 40 to 80 ° C. When the glass transition temperature is lower than 40 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. On the other hand, if the glass transition temperature is higher than 90 ° C., the low-temperature fixability is lowered, which is not preferable.

  The glass transition temperature of the linear polyester resin other than the polyester resin of the present invention is not particularly limited, but is preferably 35 to 70 ° C, and particularly preferably 40 to 65 ° C. When the glass transition temperature is lower than 35 ° C., a blocking phenomenon (thermal aggregation) tends to occur when the toner is stored, transported, or exposed to a high temperature inside the developing device of the machine. On the other hand, if the glass transition temperature is higher than 70 ° C., the low wrinkle fixing property is lowered, which is not preferable.

  The softening point of the cross-linked polyester resin other than the polyester resin of the present invention is not particularly limited, but is preferably 150 ° C. or higher, more preferably 150 ° C. to 220 ° C., and 170 ° C. to 190 ° C. It is particularly preferable that when the softening point is less than 150 ° C., the toner tends to cause agglomeration phenomenon, which is likely to cause trouble during storage or printing. It is because it becomes easy to get worse.

The softening point of the linear polyester resin other than the polyester resin of the present invention is not particularly limited, but is preferably 90 ° C or higher, more preferably 90 ° C to 130 ° C, and more preferably 90 ° C to 110 ° C. It is particularly preferable that the temperature is C. As with the cross-linked polyester resin, when the softening point is less than 90 ° C., the glass transition temperature is lowered, and the toner tends to cause aggregation phenomenon, which is likely to cause trouble during storage or printing. If the temperature exceeds 130 ° C., the fixability tends to deteriorate.
The softening point and glass transition temperature of the cross-linked and linear polyester resins are measured by the same method as the method for measuring the softening point and glass transition temperature of the polyester resin of the present invention.

  In the method for producing the toner of the present invention, waxes that can be introduced in the colored resin solution preparation step include hydrocarbon waxes such as polypropylene wax, polyethylene wax, and Fischer trophy fish wax, synthetic ester waxes, and carnauba wax. And waxes selected from natural ester waxes such as rice wax. Of these, natural ester waxes such as carnauba wax and rice wax, synthetic ester waxes obtained from a high alcohol and a long-chain monocarboxylic acid, and hydrocarbon waxes such as Fischer-Trofisch wax are suitable. Examples of the synthetic ester wax include WEP-5 and WEP-7 (manufactured by NOF Corporation). The wax content is preferably in the range of 1 to 40% by mass with respect to the total toner. If the wax content is less than 1% by mass with respect to the whole toner, the releasability becomes insufficient. It becomes easy to do.

  The colored resin solution can be prepared by mixing a charge control agent. The positively chargeable charge control agent is not particularly limited, and known and commonly used nigrosine dyes, quaternary ammonium compounds, onium compounds, triphenylmethane compounds and the like can be used for toners. In addition, basic group-containing compounds such as amino groups, imino groups, and N-heterocycles, such as tertiary amino group-containing styrene acrylic resins, are also effective as a positively chargeable charge control agent. As a control agent, it can be used alone or in combination with the positively chargeable charge control agent. Depending on the application, a small amount of a negative charge control agent such as an azo dye metal complex or a salicylic acid derivative metal complex salt may be used in combination with these positively chargeable charge control agents. In addition, as the negatively chargeable charge control agent, heavy metals such as trimethylethane dyes, salicylic acid metal complexes, benzylic acid metal complexes, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes, etc. Examples thereof include acidic dyes, calixarene-type phenol condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like. The content of the charge control agent is preferably 0.01 to 10% by mass, and particularly preferably 0.1 to 6% by mass with respect to the whole toner.

  Examples of the colorant that can be added in the colored resin solution preparation step include C.I. I. Pigment Black 11 and other iron oxide pigments, C.I. I. Examples thereof include iron-titanium complex oxide pigments such as Pigment Black 12, and carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black.

  Examples of blue colorants include phthalocyanine C.I. I. Pigment Blue 1, 2, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 15, 16, 17: 1, 27, 28, 29, 56, 60, 63 and the like. Among these, C.I. I. Pigment Blue 15: 3, 15, 16, 60 are preferable. I. Pigment Blue 15: 3, 60 is more preferable.

  Examples of yellow colorants include C.I. I. Pigment Yellow 1, 3, 4, 5, 6, 12, 13, 14, 15, 16, 17, 18, 24, 55, 65, 73, 74, 81, 83, 87, 93, 94, 95, 97, 98 , 100, 101, 104, 108, 109, 110, 113, 116, 117, 120, 123, 128, 129, 133, 138, 139, 147, 151, 153, 154, 155, 156, 168, 169, 170 , 171, 172, 173, 180, 184, 185 and the like. Among these, C.I. I. Pigment Yellow 17, 74, 93, 97, 110, 155 and 180 are preferable. I. Pigment Yellow 74, 93, 97, 180, and 184 are more preferable. I. Pigment Yellow 93, 97, 180, and 184 are more preferable.

  Examples of red colorants include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 17, 18, 22, 23, 31, 37, 38, 41, 42, 48: 1, 48 : 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58: 4, 60: 1, 63 : 1, 63: 2, 64: 1, 65, 66, 67, 68, 81, 83, 88, 90, 90: 1, 112, 114, 115, 122, 123, 133, 144, 146, 147, 149 , 150, 151, 166, 168, 170, 171, 172, 174, 175, 176, 177, 178, 179, 184, 185, 187, 188, 189, 190, 193, 194, 202, 208, 209, 214 216, 220, 221, 2 4,242,243,243: 1,245,246,247, and the like. Among these, C.I. I. Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 53: 1, 57: 1, 122, 184, 209 are preferred. I. Pigment Red 57: 1, 122, 184, and 209 are more preferable.

  The content of the colorant is preferably 1 to 20% by mass, more preferably 2 to 18% by mass, and still more preferably 2 to 15% by mass with respect to the whole toner. These colorants can be used alone or in combination of two or more.

  The toner particles produced by the production method of the present invention can be adjusted in fluidity, electrostatic property, etc. by adding fine particles such as silica and titania or those hydrophobized to these as external additives. The obtained toner particles can be used as a one-component toner, but can also be used as a two-component toner by mixing a carrier.

(Synthesis of cross-linked polyester resin 1)
Terephthalic acid 9.06 parts by mass Isophthalic acid 3.90 parts by mass Ethylene glycol 2.54 parts by mass Neopentyl glycol 4.26 parts by mass Tetrabutyl titanate 0.10 parts by mass Epicron 830 0.30 parts by mass (Dainippon Ink & Chemicals, Inc. Bisphenol F type epoxy resin, epoxy equivalent 170 (g / eq)
Cardura E 0.10 parts by mass (Shell Japan alkyl glycidyl ester) epoxy equivalent 250 (g / eq)
The above raw materials were put into a stainless steel 50 L reaction kettle and reacted for 12 hours at 200 ° C. under a normal pressure nitrogen stream until a transparent resin was obtained. Then, the temperature was reduced to 240 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 5 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 65 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 178 ° C., and a VOC content of 8 ppm. The polymer is hereinafter referred to as “H1”.

(Synthesis of cross-linked polyester resin 2)
Terephthalic acid 3.90 parts by mass Isophthalic acid 9.06 parts by mass Neopentyl glycol 4.26 parts by mass Ethylene glycol 2.54 parts by mass Tetrabutyl titanate 0.10 parts by mass Epicron 830 0.30 parts by mass (Dainippon Ink & Chemicals, Inc. Bisphenol F type epoxy resin (Epoxy equivalent 170g / eq)
0.10 parts by weight of Cardura E (Shell Japan alkyl glycidyl ester epoxy equivalent 250 g / eq)
The above raw materials were put into a stainless steel 50 L reaction kettle and reacted for 12 hours at 200 ° C. under a normal pressure nitrogen stream until a transparent resin was obtained. Then, the temperature was reduced to 240 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 5 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 60 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 178 ° C., and a VOC content of 27 ppm. The polymer is hereinafter referred to as “H2”.

(Synthesis of linear polyester resin 1)
Terephthalic acid 7.97 parts by mass Isophthalic acid 5.31 parts by mass Ethylene glycol 2.86 parts by mass Neopentyl glycol 4.80 parts by mass Tetrabutyl titanate 0.10 parts by mass or more of raw materials are placed in a 50 L stainless steel reaction kettle. The reaction was carried out for 12 hours at 200 ° C. under a normal pressure nitrogen stream until a transparent resin was obtained. Then, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 2 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 55 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 107 ° C., and a VOC content of 25 ppm. The polymer is hereinafter referred to as “L2”.

(Synthesis of linear polyester resin 2)
Terephthalic acid 7.97 parts by mass Isophthalic acid 5.31 parts by mass Ethylene glycol 2.86 parts by mass Neopentyl glycol 4.80 parts by mass Tetrabutyl titanate 0.10 parts by mass or more of raw materials are placed in a 50 L stainless steel reaction kettle. The reaction was carried out for 12 hours at 200 ° C. under a normal pressure nitrogen stream until a transparent resin was obtained. Thereafter, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 1 hour. The obtained polymer was a colorless solid, and had a glass transition temperature of 47 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 95 ° C., and a VOC content of 200 ppm. The polymer is hereinafter referred to as “L5”.

(Synthesis of linear polyester resin 3)
Terephthalic acid 53.1 parts by mass Isophthalic acid 79.7 parts by mass Ethylene glycol 26.0 parts by mass Neopentyl glycol 43.7 parts by mass Tetrabutyl titanate 0.05 parts by mass or more of raw materials were placed in a stainless steel 50 L reaction kettle, The reaction was carried out for 17 hours under a normal pressure nitrogen stream until a transparent resin was obtained at 200 ° C. Then, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 4 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 46 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 95 ° C., and a VOC content of 142 ppm. The polymer is hereinafter referred to as “L27”.

(Synthesis of linear polyester resin 4)
Terephthalic acid 53.1 parts by mass Isophthalic acid 79.7 parts by mass Ethylene glycol 26.0 parts by mass Neopentyl glycol 43.7 parts by mass Tetrabutyl titanate 0.05 parts by mass or more of raw materials were placed in a stainless steel 50 L reaction kettle, The reaction was carried out for 17 hours under a normal pressure nitrogen stream until a transparent resin was obtained at 200 ° C. Then, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 3 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 36 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 87 ° C., and a VOC content of 165 ppm. The polymer is hereinafter referred to as “L19”.

(Synthesis of linear polyester resin 5)
Terephthalic acid 53.1 parts by mass Isophthalic acid 79.7 parts by mass Ethylene glycol 26.0 parts by mass Neopentyl glycol 43.7 parts by mass Tetrabutyl titanate 0.05 parts by mass or more of raw materials were placed in a stainless steel 50 L reaction kettle, The reaction was carried out for 17 hours under a normal pressure nitrogen stream until a transparent resin was obtained at 200 ° C. Thereafter, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 5 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 49 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 98 ° C., and a VOC content of 50 ppm. The polymer is hereinafter referred to as “L21”.

(Synthesis of linear polyester resin 6)
Isophthalic acid 132.8 parts by mass Ethylene glycol 26.0 parts by mass Neopentyl glycol 43.7 parts by mass of raw materials are put into a stainless steel 50 L reaction kettle to obtain a transparent resin at 200 ° C. under a normal pressure nitrogen stream. The reaction was allowed to proceed for 18 hours. Then, the temperature was reduced to 210 ° C. and the pressure was reduced to 30 Torr, and deaeration was performed for 6 hours. The obtained polymer was a colorless solid, and had a glass transition temperature of 46 ° C. by a DSC measurement method, a softening point (T1 / 2) by a flow tester of 95 ° C., and a VOC content of 130 ppm. The polymer is hereinafter referred to as “L20”.

  Table 1 shows the softening point 1/2, the glass transition temperature Tg, and the VOC content (TVOC) of the linear polyester resins L2, L5, L27, L19, L21, L20, and the crosslinked polyester resins H1 and H2.

  The linear polyester resins L27, L19, L21, and L20, which are specific examples of the present invention, are less than half the amount of catalyst used and more than double the degassing time than the linear polyester resins L2 and L5. is there. The linear polyester resins L27, L19, L21 and L20 have a softening point and a glass transition temperature lower than those of the linear polyester resin L2. The linear polyester resins L27, L19, L21 and L20 and the linear polyester resin L5 have the same softening point and glass transition temperature, but the linear polyester resins L27, L19, L21 and L20 are the same. The VOC content is less than the VOC content of the linear polyester resin L5.

(Example 1)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by mass, linear polyester resin L2 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedec And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L2 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
20L Henschel set with 2000 parts by mass of Ket Blue 111 (Cyan Pigment manufactured by Dainippon Ink and Chemicals, Inc., CI Pigment B-15: 3) and 2000 parts by mass of a linear polyester resin L2 The mixture was put into a mixer (Mitsui Mine Co., Ltd.) and stirred at 698 min ⁻¹ for 2 minutes to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with linear polyester resin L2 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 times optical microscope, the colorant was uniformly dispersed and coarse particles There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the above wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L27 and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.46 parts by mass of the emulsion suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

(Example 2)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Kato Yoko) 30 parts by mass, linear polyester resin L27 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L27 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd., cyan pigment, CI Pigment B-15: 3) 2000 parts by mass and linear polyester resin L27 2000 parts by mass 20 L Henschel set with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with the linear polyester resin L27 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 times optical microscope, the colorant was uniformly dispersed and coarse particles were observed. There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the above wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L27 and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.46 parts by mass of the emulsion suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

(Example 3)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by mass, linear polyester resin L19 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L19 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd. cyan pigment, CI Pigment B-15: 3) 2000 parts by mass and linear polyester resin L19 2000 parts by mass 20 L Henschel set with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with linear polyester resin L19 and methyl ethyl ketone, and the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400-fold optical microscope. The colorant was uniformly dispersed and coarse particles There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L19, and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade was charged with 41.54 parts by mass (27 parts by mass of solid content) of the colored resin solution, and then 4.5 parts by mass of 1N ammonia water was added to 777 min ^−1. And the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.21 parts by mass of the emulsified suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

Example 4
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by mass, linear polyester resin L20 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L20 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd. Cyan Pigment, CI Pigment B-15: 3) 2000 parts by mass and linear polyester resin L20 2000 parts by mass 20 L Henschel set with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with the linear polyester resin L20 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 × optical microscope, the colorant was uniformly dispersed and coarse particles There was no.

(Preparation of colored resin solution)
22.5 parts by weight of the above wax master solution, 3.78 parts by weight of the colorant master chip, 4.48 parts by weight of the cross-linked polyester resin H2, 9.74 parts by weight of the linear polyester resin L20 and 7.79 parts by weight of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.21 parts by mass of the emulsified suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

(Example 5)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by mass, linear polyester resin L21 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L21 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
20L Henschel set with 2000 parts by weight of Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd., cyan pigment, CI Pigment B-15: 3) and 2000 parts by weight of linear polyester resin L21. The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with linear polyester resin L21 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 × optical microscope, the colorant was uniformly dispersed and coarse particles were observed. There was no.

(Preparation of colored resin solution)
22.5 parts by weight of the above wax master solution, 3.78 parts by weight of the colorant master chip, 4.48 parts by weight of the cross-linked polyester resin H2, 9.74 parts by weight of the linear polyester resin L20 and 7.79 parts by weight of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.21 parts by mass of the emulsified suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

(Example 6)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Kato Yoko) 30 parts by mass, linear polyester resin L27 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L27 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd., cyan pigment, CI Pigment B-15: 3) 2000 parts by mass and linear polyester resin L27 2000 parts by mass 20 L Henschel set with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with the linear polyester resin L27 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 times optical microscope, the colorant was uniformly dispersed and coarse particles were observed. There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the above wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L27 and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle.

(Comparative Example 1)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by mass, linear polyester resin L5 70 parts by mass and methyl ethyl ketone 150 parts by mass were premixed with Desper, and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L5 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
20L Henschel set with 2000 parts by mass of Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd., cyan pigment, CI Pigment B-15: 3) and 2000 parts by mass of linear polyester resin L5. The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with linear polyester resin L5 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400 times optical microscope, the colorant was uniformly dispersed and coarse particles There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the above wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L5 and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of a colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Preparation process of emulsion suspension for shell)
Mixing 7.33 parts by mass of methyl ethyl ketone and 6 parts by mass of cross-linked polyester resin H1 in a range of 35 to 40 ° C. using a desper with a blade diameter of 135 mm (manufactured by Asada Iron Works Co., Ltd.) at 1200 min ⁻¹ for 30 minutes, then 0.033 parts by mass of anionic emulsifier Neogen SC-F (Daiichi Kogyo Seiyaku Co., Ltd.) was added and mixed for 30 minutes to obtain a solution / dispersion. Next, 1.765 parts by mass of 1N aqueous ammonia was added and stirred, and the temperature was adjusted to 35 ° C. Next, the stirring speed was changed to 1550 min ⁻¹ and 13.83 parts by mass of deionized water was added dropwise at 0.6 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 11 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 10 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, the resin was dissolved and no unemulsified product was observed (Step C).

(Shelling process)
In Step B, the rotational speed was 120 min ⁻¹ , and 5.21 parts by mass of the emulsified suspension for shell obtained in Step C was added dropwise to colored resin fine particles having a particle diameter of 4.5 μm at 0.5 parts by mass / min. For 10 minutes at a rotational speed of 75 min ⁻¹ . Next, the number of revolutions was set to 120 min ⁻¹ and the above was repeated twice (added three times in total). Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 1.2 parts by mass of a 5 mass% sodium sulfate aqueous solution was dropped at 1 part by mass / min, and 5 minutes after the completion of the dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. and stirred at 65min ^-1 5 minutes, the mixture was stirred at 47min ^-1 15 minutes to stop the combined deionized water were added 10 parts by weight.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle. A core / shell structure was confirmed by observing a cross-section of the toner base particles with a microtome with a transmission electron microscope. The centrifuge filtrate was clear.

(Comparative Example 2)
(Preparation of wax master solution)
Carnauba wax (Carnauba wax No. 1, imported by Yoko Kato) 30 parts by weight, 70 parts by weight of linear polyester resin L5 and 150 parts by weight of methyl ethyl ketone were premixed with Desper and then Starmill LMZ-10 (Ashizawa Finedeck) And a wax master solution having a solid content of 40% by mass was prepared. The composition of the wax master solution is L5 / wax / methyl ethyl ketone = 28/12/60.

(Preparation of colorant master chip)
Ket Blue 111 (Dai Nippon Ink Chemical Co., Ltd., cyan pigment, CI Pigment B-15: 3) 2000 parts by mass and linear polyester resin L5 2000 parts by mass 20 L Henschel set with ST / A0 blades The mixture was put into a mixer (manufactured by Mitsui Mining Co., Ltd.) and stirred for 2 minutes at 698 min ⁻¹ to obtain a mixture. The mixture was melt-kneaded using a kneedex MOS140-800 (an open roll continuous extrusion kneader manufactured by Mitsui Mining Co., Ltd.) to prepare a master chip. The obtained master chip was diluted with the linear polyester resin L5 and methyl ethyl ketone, and when the dispersion state of the colorant and the presence or absence of coarse particles were observed with a 400-fold optical microscope, the colorant was uniformly dispersed and coarse particles There was no.

(Preparation of colored resin solution)
22.5 parts by mass of the above wax master solution, 3.78 parts by mass of the colorant master chip, 4.48 parts by mass of the cross-linked polyester resin H2, 9.74 parts by mass of the linear polyester resin L5 and 7.79 parts by mass of methyl ethyl ketone. Using a desper (manufactured by Asada Iron Works Co., Ltd.) having a blade diameter of 230 mm in the range of 40 to 45 ° C., the mixture was mixed at 777 min ⁻¹ for 2 hours for dissolution and dispersion. The resulting mixture was further added methyl ethyl ketone, the solid content was adjusted to 65% by mass, and 0.22 parts by mass of dodecylbenzenesulfonic acid-based emulsifier (Daiichi Kogyo Seiyaku Neogen SC-F) was added as an emulsifier. A colored resin solution was prepared by dissolving and dispersing (Step A).

(Emulsification process)
A cylindrical container having a blade with a blade diameter of 230 mm as a stirring blade is charged with 41.54 parts by mass (27 parts by mass of solid content) of the colored resin solution, and then 4 parts by mass of 1N ammonia water is added and stirred at 777 min ⁻¹ . Then, the temperature was adjusted to 35 ° C. Subsequently, the stirring speed was changed to 1100 min ⁻¹ and 38.25 parts by mass of deionized water was added dropwise at 10 parts by mass / min to prepare an emulsified suspension. The peripheral speed of the stirring blade at this time was 13.2 m / s. As deionized water was added, the viscosity of the system increased, but water was taken into the system at the same time as the dropwise addition, and stirring and mixing were uniform. After adding 26 parts by weight of deionized water, a sharp drop in viscosity was observed (phase inversion emulsification). Further, when a predetermined amount of the remaining deionized water was added and the emulsion suspension was observed with an optical microscope, it was observed that the resin was dissolved and the pigment and wax fine particles were dispersed (step B). . No unemulsified material was observed. Since the pigment and wax fine particles are stably dispersed in the aqueous medium, it is considered that the resin is adsorbed on the surfaces of the fine particles.

(Joint process)
Next, after the suspension was transferred to a cylindrical container attached to a Max Blend blade (registered trademark, manufactured by Sumitomo Heavy Industries) with a blade diameter of 340 mm, the temperature was maintained at 26 ° C. while maintaining the stirring speed at 85 min ^−1. It was adjusted. Thereafter, the rotational speed was adjusted to 120 min ⁻¹ , 10.8 parts by mass of a 3.5 mass% sodium sulfate aqueous solution was added dropwise at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. , 65 min ⁻¹ for 5 minutes, and 47 min ⁻¹ for 20 minutes. The peripheral speed of the stirring blade at this time was 0.47 m / s. Subsequently, the rotational speed was adjusted to 120 min ⁻¹ , 2 parts by mass of a sodium sulfate aqueous solution having a concentration of 5.0 mass% was dropped at 1 part by mass / min, and 5 minutes after the completion of dropping, the rotational speed was 85 min ⁻¹ for 5 minutes. The mixture was stirred at 65 min ⁻¹ for 5 minutes and then continued at 47 min ⁻¹ . When the particle size became 4.5 μm, the mixture was stirred at 85 min ⁻¹ for 30 minutes.

(Separation and drying process)
Thereafter, after adding 0.006 parts by mass of antifoaming agent BY22-517 (manufactured by Toray Dow Corning Silicone Co., Ltd.), methyl ethyl ketone and water were distilled off under reduced pressure until the recovered amount became 35 parts by mass. The slurry after the solvent removal was repeatedly washed by solid-liquid separation and redispersion, and then a colored resin fine particle dispersion obtained by removing the solvent with a basket type centrifuge was obtained. Then, it dried with the ribocorn mixing vacuum dryer, and it was set as the toner mother particle.

  The particle size, Dv / Dn (volume average diameter / number average diameter), average circularity, softening point T1 / 2, glass transition temperature Tg, and toner base particles obtained in Examples 1 to 6 and Comparative Examples 1 and 2 Table 2 shows the VOC content TVOC.

  The toner base particles of Examples 1 to 6 containing the polyester resin of the present invention and the toner base particles of Comparative Examples 1 and 2 containing a polyester resin having a higher VOC content than the polyester resin of the present invention have a softening point and a glass transition. The temperature is comparable. However, the VOC content of the toner base particles of Examples 1 to 6 is considerably lower than the VOC content of the toner base particles of Comparative Examples 1 and 2. Therefore, it can be seen that by using the polyester resin of the present invention, a toner having a softening point and a glass transition temperature comparable to those of a conventional toner and a low VOC content can be obtained.

Claims (5)

A toner comprising a thermoplastic polyester resin having a softening point of 90 to 100 ° C., a glass transition temperature of 35 to 50 ° C. and a volatile organic compound content of 170 ppm or less as a resin component. The toner according to claim 1, wherein the thermoplastic polyester resin is contained in an amount of 30% by mass or more based on the resin component. A step of obtaining a colored resin solution by dissolving or dispersing a binder resin, a wax and a colorant containing the thermoplastic polyester resin according to claim 1 in an organic solvent, a basic compound and water sequentially in the colored resin solution Adding, emulsifying the colored resin solution in an aqueous medium, adding an aqueous electrolyte solution to the prepared emulsion suspension, and combining the dispersoids in the emulsion suspension to produce colored resin fine particles. The method according to claim 2, wherein the particles are produced through a step of forming particles, a step of separating, washing and drying the colored resin fine particles from the aqueous medium after removing the organic solvent under reduced pressure. Toner for charge image development. 4. The toner according to claim 1, wherein the toner has a core-shell structure. The toner according to claim 1, wherein the volatile organic compound content is 50 ppm or less.