JP5553028B2 - Toner for developing electrostatic image and method for producing the same - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic charge image (hereinafter also simply referred to as “toner”) used for electrophotographic image formation and a method for producing the same.

In recent years, electrophotographic image forming apparatuses are required to have energy-saving systems in consideration of influence on the global environment. Improvements to a fixing system that consumes a large amount of energy among image forming apparatuses are progressing day by day, and in order to realize energy saving of the fixing system, there is an increasing demand for low-temperature fixability to toner.
Adopting a polyester resin that can rapidly change the melting characteristics as the temperature rises as a binder resin for toner is one of the effective means for realizing low-temperature fixing properties. Due to the goodness, problems such as difficulty in ensuring high-temperature offset resistance and formation of an image having excessive gloss may occur. Further, such a toner may be inferior in heat-resistant storage property.

  In order to solve such a problem, a method has been proposed in which a polyester resin having a cross-linked structure that suppresses a significant decrease in elasticity at high temperatures is used as a toner binder resin (see, for example, Patent Document 1). ).

However, the toner production method disclosed in Patent Document 1 relates to a pulverization method, and the pulverization method requires a great deal of energy to produce a toner having a small particle diameter. In addition, there is a limit to reducing the particle size of the toner, and in recent years, it may be difficult to achieve high image quality, which is another important quality item required for an electrophotographic image forming apparatus.
On the other hand, it is well known that it is effective to employ a polymerization method for a pulverization method in order to produce a toner having a small particle diameter. The polymerization method is a general term for a method for producing a toner by a chemical method under a wet condition (in water, an aqueous medium or an organic solvent).
As a means to achieve both low-temperature fixability and high-temperature offset resistance, suppression of excessive gloss in the formed image, and achievement of high image quality by reducing the particle size of the toner, a toner made of a polyester resin having a crosslinked structure by a polymerization method is used. Although it is conceivable to produce, the polymerization method includes a fine dispersion step of the polyester resin, the fine dispersion of the polyester resin having a crosslinked structure is impossible or requires a lot of energy. It is very difficult to balance performance.

  In order to solve the above-described problems, for example, Patent Document 2 and Patent Document 3 disclose, as a method for producing a toner containing a polyester resin having a crosslinked structure by a polymerization method, crystalline polyester resin fine particles, polymerizable non-polymerizable resin. Aggregated particles are produced by attaching core particles made of polyester resin fine particles containing saturated bonds, and polyester resin fine particles containing polymerizable unsaturated bonds to the peripheral surface of the core particles, and a radical polymerization initiator is added to the aggregated particles. A method for producing a toner having a core-shell structure by radically polymerizing a polymerizable unsaturated bond to form a crosslinked structure is disclosed.

  According to these production methods, it is possible to produce a toner containing a polyester resin having a crosslinked structure by a polymerization method. However, in the above production method, the number of steps increases because a shelling step is separately required. In addition, depending on the timing at which the radical polymerization initiator for the crosslinking reaction is applied, an aggregate of core particles or an aggregate of fine particles for forming a shell is formed, and the toner produced due to this At present, problems such as non-uniform charging characteristics occur due to the wide particle size distribution.

JP 2009-223281 A JP 2010-55094 A JP 2010-55092 A

  The present invention has been made based on the circumstances as described above, and the purpose thereof is basically capable of forming a high-quality image, and further having heat-resistant storage while having excellent low-temperature fixability. And a method for producing a toner for developing an electrostatic image, which can stably produce a toner that has excellent heat resistance and high-temperature offset resistance and can impart an appropriate gloss to an image to be formed. It is an object of the present invention to provide a toner for developing an electrostatic charge image obtained.

The method for producing a toner of the present invention is a method for producing a toner for developing an electrostatic image comprising toner particles containing a binder resin containing at least a polyester resin having a crosslinked structure,
(A-1) Step of producing fine particle aqueous medium dispersion with crystalline polyester resin (a-2) Fine particle aqueous medium dispersion with amorphous polyester resin containing polymerizable unsaturated double bond Process
Without providing a separate step of adding resin fine particles for the shell layer,
(B) In an aqueous medium, after undergoing a step of aggregating at least the fine particles of the crystalline polyester resin and the fine particles of the amorphous polyester resin containing the polymerizable unsaturated bond to form aggregated particles,
(C) A step of generating a polyester resin having a crosslinked structure by causing a radical polymerization initiator to act on the aggregated particles to perform a radical polymerization reaction is characterized.
In the method for producing a toner of the present invention, it is preferable that at least a part of the fine particles of the crystalline polyester resin to be aggregated in the step (b) comprises fine particles containing a crystalline polyester resin containing a polymerizable unsaturated bond. .

In the toner production method of the present invention, between the step (b) and the step (c),
It is preferable to go through a step of adding an aggregation terminator that suppresses aggregation of the fine particles of the crystalline polyester resin and the fine particles of the amorphous polyester resin containing a polymerizable unsaturated bond.

  The toner of the present invention is obtained by the toner production method described above.

According to the method for producing a toner of the present invention, since a crosslinked structure is formed after forming aggregated particles in a desired state in an aqueous medium, a polymerized toner containing a polyester resin having a crosslinked structure is reliably obtained. In addition, the produced toner has a high yield with respect to toner particles having a desired composition and structure, that is, has a sharp particle size distribution. As a result, while having excellent low-temperature fixability, the polyester resin having a crosslinked structure formed in the toner particles has excellent high-temperature offset resistance and heat-resistant storage stability, and is suitable for an image to be formed. Further, it is possible to stably produce a toner that can give gloss and can obtain a high-quality image with high density gradation reproducibility because of good charging characteristics due to a sharp particle size distribution.
In addition, according to this toner manufacturing method, since a cross-linked structure can be formed predominantly in the surface layer region of the aggregated particles, the so-called shell layer forming step for forming the shell layer can be omitted. The heat-resistant storage stability of the toner is ensured while simplifying the above.

  In the toner production method of the present invention, when fine particles of a crystalline polyester resin having a polymerizable unsaturated bond are used, the resulting toner has a crystalline polyester resin having a cross-linked structure, resulting in a crystalline property. The brittleness of the entire polyester resin is suppressed to a small level, and therefore the occurrence of filming in a cleaning process or the like can be suppressed.

  Hereinafter, the present invention will be specifically described.

[Toner Production Method]
The method for producing the toner of the present invention includes:
A method for producing a toner comprising toner particles containing a binder resin including at least a polyester resin having a crosslinked structure (hereinafter also referred to as “crosslinked polyester resin”),
(A-1) Step of producing an aqueous medium dispersion of fine particles (hereinafter also referred to as “crystalline polyester resin fine particles”) made of a crystalline polyester resin (a-2) Non-containing a polymerizable unsaturated double bond A step of producing an aqueous medium dispersion of fine particles from a crystalline polyester resin (hereinafter also referred to as “unsaturated amorphous polyester resin”); (b) in the aqueous medium, at least the crystalline polyester resin fine particles and After undergoing a step of agglomerating fine particles (hereinafter also referred to as “unsaturated amorphous polyester resin fine particles”) with a crystalline polyester resin to form aggregated particles,
(C) A method in which a radical polymerization initiator is allowed to act on the aggregated particles to perform a radical polymerization reaction, thereby producing a crosslinked polyester resin.

  In this toner manufacturing method, it is preferable that at least a part of the fine particles made of the crystalline polyester resin to be aggregated in the step (b) comprises fine particles containing a crystalline polyester resin containing a polymerizable unsaturated bond.

<First Embodiment>
As a specific example of such a toner production method,
(1-A-1) Crystalline polyester resin fine particle dispersion preparing step of synthesizing a crystalline polyester resin and preparing an aqueous medium dispersion of the crystalline polyester resin fine particles by the crystalline polyester resin,
(1-A-2) A crystalline polyester resin containing a polymerizable unsaturated bond (hereinafter, also referred to as “unsaturated crystalline polyester resin”) is synthesized, and fine particles (hereinafter referred to as “unsaturated crystalline polyester resin”). An unsaturated crystalline polyester resin fine particle dispersion preparing step of preparing an aqueous medium dispersion of “unsaturated crystalline polyester resin fine particles”),
(1-B-1) Amorphous polyester resin in which an amorphous polyester resin is synthesized and a dispersion of fine particles (hereinafter also referred to as “amorphous polyester resin fine particles”) of the amorphous polyester resin is prepared. Fine particle dispersion preparation process,
(1-B-2) Unsaturated amorphous polyester resin fine particle dispersion for synthesizing an unsaturated amorphous polyester resin and preparing a dispersion of unsaturated amorphous polyester resin fine particles by the unsaturated amorphous polyester resin Liquid preparation process,
(1-C) A colorant fine particle dispersion preparing step for preparing a dispersion of fine particles by colorant (hereinafter also referred to as “colorant fine particles”), if necessary,
(2) Resin fine particles used as a binder resin material such as crystalline polyester resin fine particles, unsaturated amorphous polyester resin fine particles, unsaturated crystalline polyester resin fine particles, and amorphous polyester resin fine particles in an aqueous medium; and An aggregating step for aggregating fine particles of toner constituents such as colorant fine particles, fine particles by a release agent, fine particles by a charge control agent to form aggregated particles, if necessary,
(3) an aggregation stopping step for stopping aggregation of the resin fine particles in the aqueous medium and the fine particles of the toner constituent component added as necessary to secure desired aggregated particles;
(4) a fusion process for fusing the secured aggregated particles to form fused particles;
(5) a crosslinking step of forming toner particles containing a crosslinked polyester resin by causing a radical polymerization initiator to act on the fused particles to perform a radical polymerization reaction;
(6) A filtration / washing process in which the obtained toner particles are separated from the aqueous medium, and the surfactant is washed away from the toner particles
(7) a step of drying the washed toner particles;
If necessary, (8) an external additive addition step of adding an external additive to the dried toner particles can be added.

(1-A-1) Crystalline Polyester Resin Fine Particle Dispersion Preparation Step This crystalline polyester resin fine particle dispersion preparation step synthesizes a crystalline polyester resin, which is a material of the binder resin constituting the toner particles. This is a step of preparing a dispersion of fine crystalline polyester resin particles by dispersing a fine polyester resin in an aqueous medium in the form of fine particles.
In the present invention, the crystalline polyester resin means a resin having a clear endothermic peak instead of a stepwise endothermic change in differential scanning calorimetry (DSC). The clear endothermic peak specifically means a peak in which the half-value width of the endothermic peak is within 15 ° C. when measured at a rate of temperature increase of 10 ° C./min in differential scanning calorimetry (DSC). To do. If it is such a crystalline polyester resin, it is not particularly limited. For example, for a resin having a structure in which other components are copolymerized on the main chain of the crystalline polyester resin, the resin has a clear endothermic peak as described above. If it shows, it corresponds to the crystalline polyester as used in the field of this invention.

The crystalline polyester resin used in the present invention preferably has a melting point in the range of 30 to 99 ° C, and more preferably in the range of 45 to 88 ° C.
Here, the melting point of the crystalline polyester resin indicates the temperature at the peak top of the endothermic peak. The differential scanning calorimeter “DSC-7” (manufactured by PerkinElmer) and the thermal analyzer controller “TAC7 / DX” (manufactured by PerkinElmer) DSC measurement by differential scanning calorimetry using
Specifically, 0.5 mg of crystalline polyester resin is sealed in an aluminum pan (KITNO.0219-0041), this is set in a sample holder of “DSC-7”, and the temperature is raised at 0 to 200 ° C. Heat-cool-Heat temperature control is performed under the measurement conditions of a temperature rate of 10 ° C./min and a temperature decrease rate of 10 ° C./min. Analysis was performed based on the data in Heat. However, an empty aluminum pan was used for the reference measurement.

This crystalline polyester resin preferably has a number average molecular weight (Mn) by gel permeation chromatography (GPC) soluble in tetrahydrofuran (THF) of 100 to 10,000, more preferably 800 to 5,000, and a weight average. The molecular weight (Mw) is preferably 1,000 to 50,000, more preferably 2,000 to 30,000.
When the weight-average molecular weight (Mw) of the THF soluble component in the crystalline polyester resin is less than 1,000, the resulting toner particles are compatible with the amorphous polyester resin in the fusion process described later. As a whole, the melting point may be low and the blocking resistance may be poor. When the weight average molecular weight is larger than 50,000, the obtained toner may be inferior in low-temperature fixability.

The molecular weight measurement by GPC was performed as follows. That is, using an apparatus “HLC-8220” (manufactured by Tosoh Corporation) and a column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 ° C., tetrahydrofuran (THF) was used as a carrier solvent at a flow rate of 0. The sample to be measured (crystalline polyester resin) was dissolved in tetrahydrofuran to a concentration of 1 mg / ml under a dissolution condition in which treatment was performed for 5 minutes using an ultrasonic disperser at room temperature. A sample solution is obtained by processing with a 2 μm membrane filter, and 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, detected using a refractive index detector (RI detector), and the molecular weight distribution of the measurement sample. Was measured using monodisperse polystyrene standard particles. Calculate using a quantitative curve. As a standard polystyrene sample for calibration curve measurement, molecular weights manufactured by Pressure Chemical Co., Ltd. are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1 .1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and at least about 10 standard polystyrene samples were measured, and a calibration curve It was created. A refractive index detector was used as the detector.

  The crystalline polyester resin can be generated from a dicarboxylic acid component and a diol component.

  As the dicarboxylic acid component, an aliphatic dicarboxylic acid is preferably used, and an aromatic dicarboxylic acid may be used in combination. As the aliphatic dicarboxylic acid, it is preferable to use a linear one. The dicarboxylic acid component is not limited to one type, and two or more types may be mixed and used.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. Acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid These lower alkyl esters and acid anhydrides can also be used. Among the above aliphatic dicarboxylic acids, adipic acid, sebacic acid, and 1,10-decanedicarboxylic acid are preferably used from the viewpoint of availability.

Examples of the aromatic dicarboxylic acid that can be used together with the aliphatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. Is mentioned. Among these, terephthalic acid, isophthalic acid, and t-butylisophthalic acid are preferably used from the viewpoints of availability and emulsification ease.
The amount of aromatic dicarboxylic acid used is preferably 20 component mol% or less, more preferably 10 component mol%, based on 100 mol% of the entire dicarboxylic acid component for forming the crystalline polyester resin. Hereinafter, it is particularly preferably 5 constituent mol% or less. When the amount of aromatic dicarboxylic acid used is 20 constituent mol% or less, the crystallinity of the crystalline polyester resin can be ensured, and excellent low-temperature fixability can be obtained in the produced toner. Glossiness is obtained in the formed image, and deterioration of image storage stability due to melting point depression is suppressed. Furthermore, when oil droplets are formed using an oil phase liquid containing the crystalline polyester resin, it is surely emulsified. Can be obtained.

Moreover, it is preferable to use aliphatic diol as a diol component, and you may contain diols other than aliphatic diol as needed.
As the diol component, it is more preferable to use a linear aliphatic diol having 2 to 22 carbon atoms constituting the main chain among the aliphatic diols, and further, availability and reliable low-temperature fixing. It is particularly preferable to use a straight-chain aliphatic diol having 2 to 14 carbon atoms constituting the main chain from the viewpoint of exhibiting properties and obtaining an image having high gloss.
The level at which low-temperature fixability is inhibited even when an aromatic dicarboxylic acid is used in combination as the dicarboxylic acid component because the number of carbon atoms constituting the main chain of the linear aliphatic diol used is 2 to 22 A polyester resin having a melting point of 5 is not formed, sufficient low-temperature fixability is obtained for the produced toner, and high glossiness is obtained for the finally formed image.
As the diol component, a branched aliphatic diol can also be used. In this case, from the viewpoint of ensuring crystallinity, it is used together with a linear aliphatic diol and the linear aliphatic diol. It is preferable to use at a higher ratio. By using the linear aliphatic diol in such a high proportion, it is possible to reliably obtain excellent low-temperature fixability in a toner manufactured with ensured crystallinity, and finally form an image. In this case, a decrease in image storability due to a decrease in melting point is suppressed, and further, blocking resistance can be reliably obtained.
The diol component is not limited to one type, and two or more types may be mixed and used.

  As the diol component for forming the crystalline polyester resin, the content of the aliphatic diol is preferably 80 constituent mol% or more, more preferably 90 constituent mol% or more. When the content of the aliphatic diol in the diol component is 80 constituent mol% or more, the crystallinity of the crystalline polyester resin can be ensured, and excellent low-temperature fixability can be obtained in the manufactured toner. Glossiness can be obtained in an image formed automatically.

  Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8- Octanediol, 1,9-nonanediol, 1,10-dodecanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Octadecanediol, 1,20-eicosanediol, and the like. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, and 1,10-decanediol are included. It is preferable to use it.

  Examples of diols other than aliphatic diols include diols having a sulfonic acid group.

The use ratio of the diol component to the dicarboxylic acid component is such that the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] of the diol component to the carboxyl group [COOH] of the dicarboxylic acid component is 1.5 / 1. It is preferable to be set to ˜1 / 1.5, and more preferably 1.2 / 1 to 1 / 1.2.
When the use ratio of the diol component and the dicarboxylic acid component is in the above range, a crystalline polyester resin having a desired molecular weight can be obtained with certainty.

  As a method of dispersing the crystalline polyester resin as described above in an aqueous medium, an oil phase liquid is prepared by dissolving or dispersing the crystalline polyester resin in an organic solvent, and the oil phase liquid is subjected to phase inversion emulsification or the like. And a method of removing an organic solvent after forming oil droplets in a state of being controlled to have a desired particle size by dispersing in an aqueous medium.

  In the present invention, the “aqueous medium” refers to a medium containing at least 50% by mass of water, and examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol. , Butanol, acetone, methyl ethyl ketone, dimethylformamide, methyl cellosolve, tetrahydrofuran and the like. Among these, it is preferable to use an organic organic solvent such as methanol, ethanol, isopropanol, and butanol, which is an organic solvent that does not dissolve the resin.

The amount of the aqueous medium used is preferably 50 to 2,000 parts by mass and more preferably 100 to 1,000 parts by mass with respect to 100 parts by mass of the oil phase liquid.
By making the usage-amount of an aqueous medium into said range, an oil phase liquid can be emulsified and dispersed to a desired particle size in an aqueous medium.

A dispersion stabilizer may be dissolved in the aqueous medium, and a surfactant, resin fine particles, and the like are added to the aqueous medium for the purpose of improving the dispersion stability of the oil droplets. Also good.
Examples of the dispersion stabilizer include inorganic compounds such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite, but it is necessary to remove the dispersion stabilizer from the obtained toner base particles. Therefore, it is preferable to use an acid or alkali-soluble material such as tricalcium phosphate, or from the environmental viewpoint, it is preferable to use a material that can be decomposed by an enzyme.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine Gerare also anionic surfactants and cationic surfactants having a fluoroalkyl group can be used.
The fine resin particles for improving the dispersion stability are preferably those having a particle size of 0.5 to 3 μm. Specifically, polymethyl methacrylate resin fine particles having a particle size of 1 μm and 3 μm, Examples thereof include polystyrene resin fine particles of 0.5 μm and 2 μm, polystyrene-acrylonitrile resin fine particles having a particle diameter of 1 μm, and the like.

The organic solvent used for the preparation of the oil phase liquid is preferably one having a low boiling point and low solubility in water from the viewpoint of easy removal treatment after formation of oil droplets. Examples thereof include methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene and the like. These can be used alone or in combination of two or more.
The usage-amount of an organic solvent is 1-300 mass parts normally with respect to 100 mass parts of crystalline polyester resins, Preferably it is 1-100 mass parts, More preferably, it is 25-70 mass parts.

The emulsification dispersion of the oil phase liquid can be performed using mechanical energy, and the disperser for performing the emulsification dispersion is not particularly limited, and a low-speed shear disperser, a high-speed shear disperser And a friction disperser, a high-pressure jet disperser, an ultrasonic disperser, and the like. Specific examples include a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.).
The dispersion diameter of the oil droplets is preferably 60 to 1000 nm, and more preferably 80 to 500 nm.
The dispersion diameter of the oil droplets is a volume-based median diameter measured using a laser diffraction / scattering particle size distribution measuring device “LA-750” (manufactured by Horiba, Ltd.). The dispersion diameter of the oil droplets can be controlled by the magnitude of mechanical energy at the time of emulsification dispersion.

The removal of the organic solvent after the formation of oil droplets is performed by gradually heating the entire dispersion liquid in which toner particles are dispersed in an aqueous medium in a laminar stirring state, and giving strong stirring in a certain temperature range. Then, it can be performed by an operation such as desolvation.
When toner particles are formed using a dispersion stabilizer, the dispersion stabilizer is also removed by adding an acid or alkali and mixing in addition to the removal treatment of the organic solvent.

(1-A-2) Unsaturated Crystalline Polyester Resin Fine Particle Dispersion Preparation Process This unsaturated crystalline polyester resin fine particle dispersion preparation process comprises a crystalline structure having a cross-linked structure as a binder resin material constituting toner particles. This is a step of synthesizing an unsaturated crystalline polyester resin to obtain a polyester resin, and dispersing the unsaturated crystalline polyester resin in a fine particle form in an aqueous medium to prepare a dispersion of unsaturated crystalline polyester resin fine particles. .
In the present invention, the unsaturated crystalline polyester resin is a crystalline polyester resin containing a polymerizable unsaturated bond capable of radical polymerization in its molecular chain.

  The unsaturated crystalline polyester resin is a dicarboxylic acid component and a diol component containing at least one polymerizable unsaturated bond as a dicarboxylic acid component and a diol component as raw materials in the above-described crystalline polyester resin synthesis step. It can synthesize | combine similarly except using these.

The dicarboxylic acid component and the diol component, which contain at least one polymerizable unsaturated bond,
(1) A diol component having all or part of a polymerizable unsaturated bond, and a dicarboxylic acid component having no polymerizable unsaturated bond,
(2) a diol component having no polymerizable unsaturated bond and a dicarboxylic acid component having all or part of a polymerizable unsaturated bond,
(3) A diol component having all or part of a polymerizable unsaturated bond, and a dicarboxylic acid component having all or part of a polymerizable unsaturated bond,
Any combination of

  As a diol component having a polymerizable unsaturated bond that can be used to form an unsaturated crystalline polyester resin, specifically, 2-butene-1,4-diol having a polymerizable unsaturated double bond, Alkene diols such as 3-hexene-1,6-diol and 4-octene-1,8-diol; 2-butyne-1,4 diol, 3-butyne-1,4 diol having a polymerizable unsaturated triple bond Alkynediols such as 9-octadecin-7,12diol. These can be used individually by 1 type or in combination of 2 or more types.

Specific examples of the dicarboxylic acid component having a polymerizable unsaturated bond that can be used to form a crystalline polyester resin include maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, and isododecenyl. And unsaturated aliphatic dicarboxylic acids such as succinic acid, n-dodecenyl succinic acid and n-octenyl succinic acid; and acid anhydrides or acid chlorides thereof.
These can be used individually by 1 type or in combination of 2 or more types.

The total content of the diol component having a polymerizable unsaturated bond and / or the dicarboxylic acid component having a polymerizable unsaturated bond with respect to 100 mol% of the total amount of the diol component and the dicarboxylic acid component is 1 to 10 mol% or less. It is preferred that
When the total content of the diol component having a polymerizable unsaturated bond and / or the dicarboxylic acid component having a polymerizable unsaturated bond is 1 constituent mol% or more, sufficient mechanical strength can be obtained in the obtained toner. Therefore, the risk of filming in the cleaning process can be reduced, and when the content is 10 constituent mol% or less, a rapid change in melting characteristics at the time of temperature rise peculiar to crystalline polyester resins can be achieved. It can be obtained and sufficient low-temperature fixability can be secured.

The melting point of the unsaturated crystalline polyester resin is preferably in the range of 30 to 99 ° C, and more preferably in the range of 45 to 88 ° C.
The melting point of the unsaturated crystalline polyester resin is measured by the same method as the melting point of the crystalline polyester resin except that the unsaturated crystalline polyester resin is used as a measurement sample.

This unsaturated crystalline polyester resin preferably has a number average molecular weight (Mn) by gel permeation chromatography (GPC) of THF soluble content of 100 to 10,000, more preferably 800 to 5,000, and a weight average molecular weight. (Mw) is preferably 1,000 to 50,000, more preferably 2,000 to 30,000.
When the weight-average molecular weight (Mw) of the THF soluble component in the crystalline polyester resin is less than 1,000, the resulting toner particles are compatible with the amorphous polyester resin in the fusion process described later. As a whole, the melting point may be low and the blocking resistance may be poor. When the weight average molecular weight is larger than 50,000, the obtained toner may be inferior in low-temperature fixability.
The molecular weight measurement by GPC is performed by the same method as the molecular weight measurement of the crystalline polyester resin except that the THF-soluble component of the unsaturated crystalline polyester resin is used as a measurement sample.

As a method of dispersing the unsaturated crystalline polyester resin in the aqueous medium as described above, the unsaturated crystalline polyester resin is dissolved in an organic solvent in the same manner as when the crystalline polyester resin is dispersed in the aqueous medium. Alternatively, an unsaturated crystalline polyester resin liquid is prepared by dispersion, and the unsaturated crystalline polyester resin liquid is dispersed in an aqueous medium by phase inversion emulsification or the like, so that oil droplets in a state of being controlled to a desired particle size are obtained. The method of removing an organic solvent after forming is mentioned.
The oil droplets preferably have a volume-based median diameter of 50 to 400 nm in a dispersed state, more preferably 80 to 200 nm.

(1-B-1) Amorphous polyester resin fine particle dispersion preparation step This amorphous polyester resin fine particle dispersion preparation step synthesizes an amorphous polyester resin as a binder resin material constituting the toner particles. In this step, the amorphous polyester resin is dispersed in the form of fine particles in an aqueous medium to prepare a dispersion of amorphous polyester resin fine particles.
In the present invention, the non-crystalline polyester resin refers to a polyester other than the above crystalline polyester resin, and usually has a melting point and a relatively high glass transition point (Tg).

  The amorphous polyester resin can be synthesized using a polyhydric alcohol component and a polyvalent carboxylic acid component in the same manner as the above-described crystalline polyester resin synthesis step.

The glass transition point (Tg) of the amorphous polyester resin is preferably 20 to 90 ° C, and particularly preferably 35 to 65 ° C.
Here, the glass transition point (Tg) of the amorphous polyester resin is determined using a differential scanning calorimeter “DSC-7” (manufactured by PerkinElmer) and a thermal analyzer controller “TAC7 / DX” (manufactured by PerkinElmer). It is measured. Specifically, 4.50 mg of amorphous polyester resin is sealed in an aluminum pan “KITNO.0219-0041”, which is set in a sample holder of “DSC-7”, and empty aluminum is used for reference measurement. Heat-cool-Heat temperature control was performed at a measurement temperature of 0 to 200 ° C. under a measurement temperature of 0 ° C./minute and a temperature decrease rate of 10 ° C./minute using a bread-making process. Data on Heat is acquired, and the glass transition point is the intersection of the baseline extension before the rise of the first endothermic peak and the tangent line indicating the maximum slope between the rise of the first endothermic peak and the peak apex. Shown as (Tg). 1st. When heating the heat, hold at 200 ° C. for 5 minutes.

This amorphous polyester resin preferably has a number average molecular weight (Mn) determined by gel permeation chromatography (GPC) of THF soluble content of 2,000 to 10,000, more preferably 2,500 to 8,000, The weight average molecular weight (Mw) is preferably 3,000 to 100,000, more preferably 4,000 to 70,000.
When the weight-average molecular weight (Mw) of the THF-soluble component in the amorphous polyester resin is less than 3,000, the resulting toner may be inferior in blocking resistance. Therefore, there is a possibility that the obtained toner may not have low temperature fixability.
The molecular weight measurement by GPC is performed by the same method as the molecular weight measurement of the crystalline polyester resin except that the THF-soluble component of the amorphous polyester resin is used as a measurement sample.

  Examples of the polyhydric alcohol component to form the amorphous polyester resin include, in addition to the above-mentioned aliphatic diol, bisphenols such as bisphenol A and bisphenol F, and ethylene oxide adducts and propylene oxide adducts thereof. Examples include bisphenol alkylene oxide adducts, and examples of the trihydric or higher polyhydric alcohol component include glycerin, trimethylolpropane, pentaerythritol, and sorbitol. Furthermore, it is preferable to use cyclohexanedimethanol, neopentyl alcohol, etc. from a manufacturing cost and environmental property. These can be used individually by 1 type or in combination of 2 or more types.

  Examples of the polyvalent carboxylic acid component to form an amorphous polyester resin include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid in addition to the above-mentioned aliphatic dicarboxylic acid. A trivalent or higher polyvalent carboxylic acid component such as trimellitic acid or pyromellitic acid may be used for the purpose of making the melt viscosity of the obtained amorphous polyester resin appropriate. These can be used individually by 1 type or in combination of 2 or more types.

As a method for dispersing the amorphous polyester resin in the aqueous medium, the amorphous polyester resin is dissolved or dispersed in an organic solvent in the same manner as when the crystalline polyester resin is dispersed in the aqueous medium. The oil phase liquid is prepared, and the oil phase liquid is dispersed in an aqueous medium by phase inversion emulsification or the like to form oil droplets in a state of being controlled to a desired particle size, and then the organic solvent is removed. A method is mentioned.
The dispersion diameter of the oil droplets is preferably 60 to 1000 nm, and more preferably 80 to 500 nm.
The dispersion diameter of the oil droplets is a volume-based median diameter measured using a laser diffraction / scattering particle size distribution measuring device “LA-750” (manufactured by Horiba, Ltd.). The dispersion diameter of the oil droplets can be controlled by the magnitude of mechanical energy at the time of emulsification dispersion.

(1-B-2) Unsaturated Amorphous Polyester Resin Fine Particle Dispersion Preparation Process This unsaturated amorphous polyester resin fine particle dispersion preparation process has a cross-linked structure that serves as a binder resin material constituting the toner particles. An unsaturated amorphous polyester resin for obtaining an amorphous polyester resin is synthesized, and the unsaturated amorphous polyester resin is dispersed in the form of fine particles in an aqueous medium to obtain a dispersion of unsaturated amorphous polyester resin fine particles. Is a step of preparing
In the present invention, the unsaturated amorphous polyester resin contains a polymerizable unsaturated bond capable of radical polymerization in its molecular chain, and unlike the above crystalline polyester resin, it usually does not have a melting point. It has a high glass transition point (Tg).

  The unsaturated amorphous polyester resin uses a polyhydric alcohol component containing at least one polymerizable unsaturated bond and a polyvalent carboxylic acid component in the same manner as the above-described crystalline polyester resin synthesis step. Can be synthesized.

The polyvalent diol and polyvalent dicarboxylic acid containing a polymerizable unsaturated bond in at least one of the following:
(1) a polyhydric alcohol component having all or part of a polymerizable unsaturated bond, and a polyvalent carboxylic acid component having no polymerizable unsaturated bond,
(2) a polyhydric alcohol component having no polymerizable unsaturated bond and a polyvalent carboxylic acid component having all or part of a polymerizable unsaturated bond,
(3) a polyhydric alcohol component having all or part of a polymerizable unsaturated bond, and a polyvalent carboxylic acid component having all or part of a polymerizable unsaturated bond,
Any combination of

The glass transition point (Tg) of the unsaturated amorphous polyester resin is preferably 20 to 90 ° C, and particularly preferably 35 to 65 ° C.
Moreover, it is preferable that the softening point of this amorphous polyester resin is 70-220 degreeC, and it is especially preferable that it is 80-180 degreeC.
The glass transition point of the unsaturated amorphous polyester resin is measured by the same method as the glass transition point of the amorphous polyester resin except that the unsaturated amorphous polyester resin is used as a measurement sample.
The softening point of the unsaturated amorphous polyester resin was measured in the same manner as in the method for measuring the softening point of the toner described in detail below, except that an unsaturated amorphous polyester resin was used as the measurement sample. Is done.

This unsaturated amorphous polyester resin has a number average molecular weight (Mn) by gel permeation chromatography (GPC) of a THF soluble content of preferably 1,000 to 15,000, more preferably 1,500 to 10, 000, and the weight average molecular weight (Mw) is preferably 2,000 to 50,000, more preferably 2,000 to 30,000.
The molecular weight measurement by GPC is performed by the same method as the molecular weight measurement of the crystalline polyester resin except that the THF-soluble component of the unsaturated amorphous polyester resin is used as a measurement sample.

  Examples of the polyhydric alcohol component that can be used to form the unsaturated amorphous polyester resin include polyhydric alcohol components for synthesizing the above-described amorphous polyester resin, and polymerization of the unsaturated amorphous polyester resin. When introducing an unsaturated bond from a polyhydric alcohol component, the polyhydric alcohol component that can be used to form an unsaturated amorphous polyester resin can be used to form an unsaturated crystalline polyester resin. The same thing as the diol component which has an unsaturated bond can be mentioned. These can be used individually by 1 type or in combination of 2 or more types.

  In addition, examples of the polyvalent carboxylic acid component that can be used to form the amorphous polyester resin include polyvalent carboxylic acids for synthesizing the above-described amorphous polyester resin, and polymerization of the unsaturated amorphous polyester resin. When the unsaturated unsaturated bond is introduced from the polyvalent carboxylic acid component, the polyvalent carboxylic acid component that can be used to form the unsaturated amorphous polyester resin can be used to form the unsaturated crystalline polyester resin. The same thing as the dicarboxylic acid component which has a polymerizable unsaturated bond can be mentioned. These can be used individually by 1 type or in combination of 2 or more types.

The total content of the polyhydric alcohol component having a polymerizable unsaturated bond and / or the polyvalent carboxylic acid component having a polymerizable unsaturated bond with respect to 100 mol% of the total amount of the polyhydric alcohol component and the polyvalent carboxylic acid component is: It is preferable to be 1-10 constituent mol% or less.
When the total content of the polyhydric alcohol component having a polymerizable unsaturated bond and / or the polyvalent carboxylic acid component having a polymerizable unsaturated bond is 1 constituent mol% or more, sufficient mechanical properties are obtained for the obtained toner. Strength can be obtained to ensure heat-resistant storage stability of the toner, and excellent high-temperature offset resistance can be obtained in the fixing process, and it is possible to obtain a fixed image imparted with moderate gloss by suppressing excessive gloss. Further, when the content is 10 constituent mol% or less, sufficient low-temperature fixability can be secured.

As a method for dispersing the unsaturated amorphous polyester resin in the aqueous medium as described above, the unsaturated amorphous polyester resin is dispersed in an organic solvent in the same manner as when the crystalline polyester resin is dispersed in the aqueous medium. An unsaturated amorphous polyester resin solution is prepared by dissolving or dispersing in an aqueous solution, and the unsaturated amorphous polyester resin solution is dispersed in an aqueous medium by phase inversion emulsification or the like, and the particle size is controlled to a desired particle size. A method of removing the organic solvent after forming oil droplets in a state is mentioned.
The oil droplets preferably have a volume-based median diameter of 50 to 400 nm in a dispersed state, more preferably 80 to 200 nm.

(1-C) Colorant Fine Particle Dispersion Preparation Step This colorant fine particle dispersion preparation step is a step that is performed as necessary when toner particles containing a colorant are desired. This is a step of preparing a dispersion of colorant fine particles by dispersing in a fine particle form in a medium.

[Colorant]
As the colorant, generally known dyes and pigments can be used.
As a colorant for obtaining a black toner, various known materials such as carbon black such as furnace black and channel black, magnetic materials such as magnetite and ferrite, dyes, and inorganic pigments containing nonmagnetic iron oxide are arbitrarily selected. Can be used.
As the colorant for obtaining a color toner, known ones such as dyes and organic pigments can be arbitrarily used. Specifically, examples of the organic pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 166, 177, 178, 222, 238 269, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Blue 15; 3, 60, 76, and the like. Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 68, 11, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 69, 70, 93, 95 and the like.
The colorant for obtaining the toner of each color can be used alone or in combination of two or more for each color.

The colorant can be dispersed using mechanical energy.
The colorant fine particles preferably have a volume-based median diameter of 10 to 300 nm in a dispersed state, more preferably 100 to 200 nm, and particularly preferably 100 to 150 nm.
The volume-based median diameter of the colorant fine particles is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.).

(2) Aggregation step This agglomeration step comprises a dispersion of crystalline polyester resin fine particles, a dispersion of unsaturated amorphous polyester resin fine particles, a dispersion of unsaturated crystalline polyester resin fine particles, and a dispersion of amorphous polyester resin fine particles. And, if necessary, a dispersion of colorant fine particles and / or a dispersion of other toner particle constituents such as a release agent and a charge control agent are added and mixed, and the repulsive force of the fine particle surface by pH adjustment And agglomerating agent by adding an aggregating agent composed of an electrolyte body, and agglomerating slowly while keeping the average particle size and particle size distribution controlled, and at the same time, by heating and stirring, the fine particles are fused. This is a step of forming aggregated particles containing at least crystalline polyester resin fine particles by performing shape control.
In this aggregation step, it is preferable to adjust the pH of the reaction system to 2-5.

The surfactant is not particularly limited, and various known ones can be used, but sulfonates such as sodium dodecylbenzenesulfonate and sodium arylalkylpolyethersulfonate; sodium dodecylsulfate, sodium tetradecylsulfate, Sulfate ester salts such as sodium pentadecyl sulfate and sodium octyl sulfate; ionic surface activity such as fatty acid salts such as sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate Agents.
Also, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and propylenoxide, sorbitan ester Nonionic surfactants such as can also be used.
The above surfactants can be used alone or in combination of two or more as desired.

  Examples of the aggregating agent that can be used in the aggregating step include monovalent, divalent, and trivalent metal salts. Examples of the metal constituting the flocculant include alkali metals such as lithium, potassium, and sodium; alkaline earth metals such as magnesium, calcium, strontium, and barium; and aluminum. Examples of the metal counter ion (anion constituting the salt) include chloride ion, bromide ion, iodide ion, carbonate ion, sulfate ion and the like.

  The addition ratio of the crystalline polyester resin fine particles to the reaction system in this aggregation step is preferably adjusted so that the content of the crystalline polyester resin in the finally obtained toner particles is 20 to 70% by mass. . If the amount is less than 20% by mass, the obtained toner may not be able to obtain sufficient low-temperature fixability. If the amount is more than 70% by mass, the mechanical strength of the obtained toner may be impaired. is there.

  In the present invention, the resin that forms the binder resin to be contained in the aggregated particles only needs to contain at least a crosslinked polyester resin. The amorphous polyester resin having a crosslinked structure, the crystalline polyester resin having a crosslinked structure. Further, a crystalline polyester resin having no cross-linked structure, an amorphous polyester resin having no cross-linked structure, and other resins may be further contained.

The addition ratio of the amorphous polyester resin fine particles to the reaction system is such that the total content of the amorphous polyester resin and the unsaturated amorphous polyester resin in the finally obtained toner particles is 10 to 60% by mass. It is preferable to adjust so that. If the amount is less than 10% by mass, the obtained toner may not have sufficient mechanical strength. If the amount is more than 60% by mass, sufficient low-temperature fixability may not be obtained for the obtained toner. is there.
Further, the relative addition of the total of the crystalline polyester resin fine particles and the unsaturated crystalline polyester resin fine particles and the total of the amorphous polyester resin fine particles and the unsaturated amorphous polyester resin fine particles in the aggregation process to the reaction system The mass ratio is preferably 85:15 to 25:75 by mass ratio, more preferably 70:30 to 40:60. When the polyester resin fine particles related to crystallinity are excessive, the obtained toner may be inferior in heat-resistant storage stability, and when the polyester resin fine particles related to crystallinity is insufficient, sufficient toner is obtained. Low temperature fixability may not be obtained.

  Further, the content ratio of the monomer containing a polymerizable unsaturated bond in all the monomers for forming the polyester resin constituting the toner, that is, the constituent mol% of all the monomers for forming the crystalline polyester resin and the amorphous % Of the monomer containing a polymerizable unsaturated bond in all monomers for forming the crystalline polyester resin and 100% by mole of the total mole% of all the monomers for forming the crystalline polyester resin. The total of the constituent mol% of the monomer containing a polymerizable unsaturated bond in all the monomers for forming the crystalline polyester resin is preferably 9 constituent mol% or less. By being in this range, sufficient mechanical strength can be obtained while ensuring sufficient low-temperature fixability.

  The addition ratio of the colorant fine particles to the reaction system in this aggregation step is preferably such that the content in the finally obtained toner particles is 1 to 10% by mass, more preferably 2 to 8% by mass. %. If the content of the colorant is less than 1% by mass in the toner, the desired coloring power may not be obtained. On the other hand, if the content of the colorant exceeds 10% by mass in the toner, coloring will occur. The release of the agent and the adhesion to the carrier may occur, which may affect the chargeability.

When an internal additive such as a release agent or a charge control agent is introduced into the toner particles, a dispersion liquid of internal additive fine particles consisting only of the internal additive is prepared before the aggregation step (2). In the step (2), the dispersion of the crystalline polyester resin fine particles, the dispersion of the amorphous polyester resin fine particles, the dispersion of the unsaturated amorphous polyester resin fine particles, the dispersion of the colorant fine particles and the internal additive fine particles Mix the dispersion.
Further, for example, in the amorphous polyester resin fine particle dispersion preparation step (1-B-1) or the unsaturated amorphous polyester resin fine particle dispersion preparation step (1-B-2), the amorphous polyester resin fine particles It is also possible to introduce into the toner particles by using the above-mentioned internal additives mixed in the saturated amorphous polyester resin fine particles.

〔Release agent〕
The release agent is not particularly limited, and known ones can be used. Specifically, for example, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; plant waxes such as synthetic ester wax, carnauba wax, rice wax, candelilla wax, wood wax, jojoba oil; montan wax, paraffin wax , Minerals such as microcrystalline wax and Fischer-Tropsch wax, petroleum-based wax; and modified products thereof.
The amount of the release agent added is usually 0.5 to 25 parts by mass, preferably 3 to 15 parts by mass with respect to 100 parts by mass of the binder resin in the finally obtained toner particles.

[Charge control agent]
Various known compounds can be used as the charge control agent.
The amount of the charge control agent added is usually 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the binder resin in the finally obtained toner particles. .

  The temperature of the reaction system in this aggregation step, that is, the aggregation temperature is preferably 10 to 35 ° C, and more preferably 20 to 30 ° C. By setting the agglomeration temperature in such a range, an appropriate speed is secured for the formation of the agglomerated particles, so that the agglomerated particles can be stably formed.

(3) Aggregation stopping step This aggregation stopping step is a step of securing aggregated particles having a desired composition and shape by stopping aggregation of various fine particles in the reaction system. In order to suppress the aggregating action of the fine particles in the agglomeration, an aggregation terminator made of a base compound that can adjust the pH in a direction away from the pH environment in which the aggregating action of the fine particles in the aggregating step (2) is promoted is added. This is done.
In this aggregation stopping step, it is preferable to adjust the pH of the reaction system to 5-9.
As the aggregation terminator (base compound), alkali metal salts such as ethylenediaminetetraacetic acid (EDTA) and its sodium salt, gluconal, sodium gluconate, potassium citrate and sodium citrate, nitrotriacetate (NTA) salt, GLDA (commercially available) L-glutamic acid N, Ndiacetic acid), humic acid and fulvic acid, maltol and ethyl maltol, pentaacetic acid and tetraacetic acid, known water-soluble polymers having both carboxyl group and hydroxyl group (polymer electrolyte) , Sodium hydroxide, potassium hydroxide and the like. Of these, alkali metal salts such as ethylenediaminetetraacetic acid (EDTA) and its sodium salt are particularly preferably used.

(4) Fusion process This fusion process is carried out in the aggregation stop step (3) by heating the reaction system to the desired fusion temperature after passing through the aggregation stop step (3). A process of forming fused particles by fusing the unsaturated amorphous polyester resin fine particles, unsaturated crystalline polyester resin fine particles, crystalline polyester resin fine particles, and amorphous polyester resin fine particles constituting the particles to fuse the aggregated particles It is.

The fusing temperature related to this fusion step is a temperature not lower than the glass transition point (Tg) of the unsaturated amorphous polyester resin or amorphous polyester resin and not higher than the melting point of the crystalline polyester resin or unsaturated crystalline polyester resin. It is preferable that
Moreover, it is preferable that the time to heat, ie, the fusion | melting time, is 1 hour or more, More preferably, it is 1 to 10 hours, More preferably, it is 2 to 5 hours.
The toner particles obtained by fusing at the fusing temperature and fusing time as described above tend to have both low-temperature fixability and heat-resistant storage stability.

(5) Crosslinking step This crosslinking step is performed by adding a radical polymerization initiator to the reaction system, and the polymerization failure in the unsaturated amorphous polyester resin present in the fused particles obtained through the fusing step (4). It acts as a shell layer by forming a cross-linked structure in the toner particles by radical polymerization reaction of saturated bonds, and in particular by forming a cross-linked structure in the unsaturated amorphous polyester resin present on the surface layer of the fused particles. It is a process of forming a layer.
By this process, an amorphous polyester resin having a crosslinked structure that exhibits high elasticity can be formed in the toner particles, the mechanical strength of the toner is improved, and high-temperature offset resistance during image formation is ensured. And excessive gloss in the obtained image can be suppressed.
The core part far from the surface layer of the fused particles is less likely to be cross-linked. For this reason, in the obtained toner particles, the closer to the core part, the more the polymerizable unsaturated bond is not subjected to radical polymerization reaction. The state that remains in the state.

  As the radical polymerization initiator that can be used in this cross-linking step, a known one can be used as long as it is a water-soluble polymerization initiator. Specifically, for example, 2,2′-azobis [2- (2- Imidazolin-2-yl) propane] dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] disulfate anhydride, 2,2′-azobis (2-methylpropionamidine) ) Dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis {2- [1- (2-hydroxyethyl)- 2-Imidazolin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis (1-imino-1-pyrrolidino- 2-Ethylop Pan) dihydrochloride, 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis [2-methyl- Water-soluble azo initiators such as N- (2-hydroxyethyl) propionamide]; persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, and hydrogen peroxide A water-soluble polymerization initiator can be mentioned. These 1 type (s) or 2 or more types can be used in combination.

The addition amount of the radical polymerization initiator added to the reaction system is 1 to 20% by mass when the total amount of the unsaturated amorphous polyester resin fine particles used for constituting the toner particles is 100% by mass. It is preferable, and it is more preferable to set it as 5-15 mass%.
When the addition amount of the radical polymerization initiator added to the reaction system is in the above range, generation of unnecessary particles in the reaction system is suppressed, and a high production yield is obtained.

The crosslinking temperature related to the formation of the crosslinked structure in the crosslinking step is not less than the decomposition temperature of the radical polymerization initiator used or the glass transition point of the amorphous polyester resin, and not more than the melting point of the crystalline polyester resin. Preferably there is.
If the crosslinking temperature is lower than the decomposition temperature of the radical polymerization initiator used or the glass transition point of the amorphous polyester resin, the crosslinking reaction may not proceed sufficiently, and the crosslinking temperature may be a crystalline polyester. When the melting point of the resin is exceeded, the crystalline polyester resin is compatible with the amorphous polyester resin, and thus there is a possibility that sufficient low-temperature fixability cannot be obtained.
Moreover, it is preferable that the crosslinking time concerning formation of the crosslinked structure in a crosslinking process is 1 hour or more, More preferably, it is 1 to 10 hours, More preferably, it is 2 to 5 hours.
Toner particles obtained by crosslinking at such a crosslinking temperature and crosslinking time are likely to ensure both low-temperature fixability and heat-resistant storage stability.

(6) Filtration / Washing Step In this filtration / washing step, the obtained dispersion of toner particles is cooled, and the toner particles are solid-liquid separated from the cooled dispersion of toner particles, and the toner particles are filtered off. A filtration treatment and a washing treatment for removing deposits such as a surfactant from the toner particles (cake-like aggregate) separated by filtration are performed. Specific solid-liquid separation and washing methods include, for example, a centrifugal separation method, a vacuum filtration method using Nutsche and the like, a filtration method using a filter press, and the like, and these are not particularly limited.

(7) Drying Step In this drying step, the toner particles that have been subjected to the washing treatment are dried. The dryers used in this drying process include spray dryers, vacuum freeze dryers, vacuum dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers, and agitation dryers. These are not particularly limited. The moisture content in the dried toner particles is preferably 5% by mass or less, and more preferably 2% by mass or less.

Here, the water content of the toner particles is measured by the Karl Fischer coulometric titration method. Specifically, an automatic thermal vaporization moisture measurement system “AQS-724” (manufactured by Hiranuma Sangyo Co., Ltd.) comprising a moisture meter “AO-6, AQI-601” (interface for AQ-6) and a heating vaporizer “LE-24S”. ), 0.5 g of toner particles left for 24 hours in an environment of 20 ° C. and 50% RH are accurately weighed into a 20 ml glass sample tube, and a Teflon (registered trademark) -coated silicone rubber packing is used. Then, the water content in the sealed environment is measured using the following measurement conditions and reagents. Furthermore, in order to correct the moisture content in the sealed environment, two empty samples are measured simultaneously.
Sample heating temperature: 110 ° C
-Sample heating time: 1 minute-Nitrogen gas flow rate: 150 mL / min-Reagent: Counter electrode solution (catholyte); Hydranal Coulomat CG-K (HYDRANAL (R) -Coulomat CG-K), generating solution (anolyte); Hydranal Coulomat AK (HYDRANAL (R) -Coulomat AK)

  Further, when the dried toner particles are aggregated by weak interparticle attractive force to form an aggregate, the aggregate may be crushed. Here, as the crushing treatment apparatus, a mechanical crushing apparatus such as a jet mill, a Henschel mixer, a coffee mill, or a food processor can be used.

(8) External additive addition step This external additive addition step is a step of adding a charge control agent and various inorganic fine particles to the dried toner particles for the purpose of adjusting flow characteristics, charging characteristics and improving cleaning properties. This is a step of adding fine particulate external additives such as organic fine particles and a lubricant. Examples of the apparatus used for adding the external additive include various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer.
The fine particles that can be used as the external additive are preferably inorganic oxide particles such as silica, titania, and alumina, and these inorganic fine particles are preferably hydrophobized with a silane coupling agent or a titanium coupling agent. .
The amount of the external additive added is 0.1 to 5.0% by mass in the toner, preferably 0.5 to 4.0% by mass. In addition, various external additives may be used in combination.

<Second Embodiment>
As another specific example of the method for producing the toner of the present invention, there is a method in which the fusion step (4) and the crosslinking step (5) in the first embodiment are carried out in the same manner except that they are carried out simultaneously. You can also.
Specifically, as described above, (1-A-1) crystalline polyester resin fine particle dispersion preparation step, (1-A-2) unsaturated crystalline polyester resin fine particle dispersion preparation step, (1-B -1) Amorphous polyester resin fine particle dispersion preparation step, (1-B-2) Unsaturated amorphous polyester resin fine particle dispersion preparation step, (1-C) Colorant fine particle dispersion preparation step, (2) Conditions under which a radical polymerization reaction of a polymerizable unsaturated bond by unsaturated amorphous polyester resin fine particles and unsaturated crystalline polyester resin fine particles proceeds on the aggregated particles produced through the aggregation step and (3) the aggregation stopping step; and In a condition where fusion proceeds, by adding a radical polymerization initiator to the reaction system, the crosslinking step and the fusion step are simultaneously performed to form a layer having an action like a shell layer. It can be formed if the particle.
In addition, from the viewpoint of ease of fusion of the aggregated particles, the method according to the first embodiment is more preferable than the fusion step and the crosslinking step performed simultaneously as in the method according to the second embodiment. Thus, it is preferable that a crosslinking process is performed after a fusion process is performed.

According to the toner manufacturing method as described above, since the crosslinked structure is formed after the aggregated particles are formed in a desired state in the aqueous medium, the polymerized toner containing the polyester resin having the crosslinked structure reliably. In addition, the manufactured toner has a high yield of toner particles having a desired composition and structure, that is, has a sharp particle size distribution. As a result, while having excellent low-temperature fixability, the polyester resin having a crosslinked structure formed in the toner particles has excellent high-temperature offset resistance and heat-resistant storage stability, and is suitable for an image to be formed. Further, it is possible to stably produce a toner capable of imparting gloss and having high density gradation reproducibility due to good charging characteristics due to a sharp particle size distribution.
In addition, according to this toner manufacturing method, since a cross-linked structure can be formed predominantly in the surface layer region of the aggregated particles, the so-called shell layer forming step for forming the shell layer can be omitted. The heat-resistant storage stability of the toner is ensured while simplifying the above.
In addition, in the toner production method of the present invention, when unsaturated crystalline polyester resin fine particles are used, the resulting toner has a crystalline polyester resin having a crosslinked structure, and the entire crystalline polyester resin is brittle. Therefore, the occurrence of filming in the cleaning process or the like can be suppressed.

The reason why toner particles having a desired composition and structure can be obtained in a high yield by forming a crosslinked structure after forming aggregated particles in a desired state is considered as follows.
That is, at the time when the radical polymerization initiator is allowed to act, since the formation of aggregates of fine particles by the amorphous polyester resin containing a polymerizable unsaturated bond is suppressed, an aqueous system is used after the radical polymerization reaction. This is considered to be because the formation of a crosslinked product of the aggregate in the medium is suppressed.

〔toner〕
The toner of the present invention is obtained by the production method as described above, and specifically comprises toner particles containing a binder resin containing at least a crosslinked polyester resin.
Further, the softening point of the toner is preferably 80 to 220 ° C., particularly preferably 80 to 150 ° C.
Here, the softening point of the toner is measured as follows. That is, first, in an environment of 20 ° C. and 50% RH, 1.3 g of toner is put in a petri dish and flattened, left to stand for 12 hours or more, and then 3820 kg / mm by a molding machine “SSP-10A” (manufactured by Shimadzu Corporation). Pressurize with a force of cm ² for 30 seconds to prepare a cylindrical molded sample having a diameter of 1 cm. Next, this molded sample was heated by a flow tester “CFT-500D” (manufactured by Shimadzu Corporation) under a 24 ° C., 50% RH environment, with a load of 196 N (20 kgf), a starting temperature of 60 ° C., and a preheating time of 300 seconds. Extruding from the hole of the cylindrical die (1 mm diameter x 1 mm) at the speed of 6 ° C / min using a 1 cm diameter piston from the end of preheating, and setting the offset value to 5 mm using the melting temperature measurement method of the temperature rising method The measured offset method temperature T _offset was taken as the softening point.

[Particle size of toner particles]
The toner obtained by the above manufacturing method preferably has a volume-based median diameter of 3 to 8 μm from the viewpoint of improving transfer characteristics, improving image quality, and fixing at low temperature.
The toner particle size distribution preferably has a CV value of 0 to 25, and more preferably 5 to 20. When the CV value is within this range, the uniformity of the charging characteristics of the toner becomes high, and high density gradation reproducibility can be obtained in the formed image.
The CV value is obtained by the following formula (x). However, the arithmetic average particle diameter is an average value of the volume-based particle diameter x for 25,000 toner particles.
Formula (x): CV value (%) = {(standard deviation) / (arithmetic mean particle size)} × 100

The volume-based median diameter and arithmetic average particle diameter of the toner are measured by “Coulter Multisizer III” (manufactured by Beckman Coulter, Inc.).
Specifically, 0.02 g of toner is added to 20 mL of a surfactant solution (for example, a surfactant solution in which a neutral detergent containing a surfactant component is diluted 10-fold with pure water for the purpose of dispersing the toner). Then, ultrasonic dispersion was performed for 1 minute to prepare a toner dispersion, and this toner dispersion was measured in a beaker containing an electrolytic solution “ISOTONII” (manufactured by Beckman Coulter) in a sample stand. Pipette until the displayed concentration of the device is 5-10%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measurement device, the measurement particle count is 25,000, the aperture diameter is 50 μm, the frequency range is calculated by dividing the measurement range of 1 to 30 μm into 256, and the volume integrated fraction is 50% from the largest. The particle diameter (volume D50% diameter) is defined as the volume-based median diameter.

[Average circularity of toner]
In addition, the toner obtained by the manufacturing method as described above has an average circularity of 0.930 to 1.000 from the viewpoints of charging property stability and low-temperature fixability with respect to individual toner particles constituting the toner. It is preferable that it is 0.950 to 0.995.
When the average circularity is in the above range, the individual toner particles are not easily crushed, the contamination of the frictional charge imparting member is suppressed, the toner chargeability is stabilized, and the toner layer transferred to the recording material As a result, the toner particle packing density is increased, fixing property is improved, and fixing offset is less likely to occur.

The average circularity of the toner particles is a value measured using “FPIA-2100” (manufactured by Sysmex). Specifically, the toner is blended with an aqueous solution containing a surfactant, and subjected to ultrasonic dispersion treatment for 1 minute to disperse, and then measurement conditions HPF (high magnification imaging) are performed according to “FPIA-2100” (manufactured by Sysmex). ) Mode, photographing is performed at an appropriate density of 3,000 to 10,000 HPF detections, the circularity is calculated according to the following formula (y) for each toner particle, and the circularity of each toner particle is added. , A value calculated by dividing by the total number of toner particles. If the number of HPF detections is in the above range, reproducibility can be obtained.
Formula (y):
Circularity = (perimeter of a circle with the same projected area as a particle image) / (perimeter of a particle role image)

[Glass transition point and softening point of toner]
The toner of the present invention preferably has a glass transition point (Tg) of 30 to 60 ° C., particularly 40 to 55 ° C.
Here, the glass transition point (Tg) is measured by the same method as described above except that the measurement sample is toner.

[Mechanical strength of toner]
Furthermore, the toner of the present invention preferably has a mechanical strength with a 10% deformation strength of 9 to 50 MPa.
This 10% deformation strength is a value measured in a compression test mode using a micro compression tester “MCT-W201” (manufactured by Shimadzu Corporation).

(Developer)
For example, the above toner may be used as a one-component magnetic toner containing a magnetic material, mixed with a so-called carrier to be used as a two-component developer, or a non-magnetic toner may be used alone. Any of these can be suitably used.

As the carrier constituting the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. It is particularly preferable to use ferrite particles.
The carrier preferably has a volume average particle diameter of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction particle size distribution measuring apparatus “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.
As the carrier, a carrier coated with a resin or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin can be used. The resin composition for coating is not particularly limited, and for example, olefin resin, styrene resin, styrene-acrylic resin, silicone resin, ester resin, or fluorine-containing polymer resin is used. Moreover, it does not specifically limit as resin for comprising a resin dispersion type carrier, A well-known thing can be used, For example, a styrene-acrylic resin, a polyester resin, a fluorine resin, a phenol resin etc. are used. be able to.

(Image forming method)
The toner as described above can be suitably used for an image forming method including a fixing step by a contact heating method. Specifically, as an image forming method, an electrostatic latent image electrostatically formed on an image carrier such as a photosensitive drum using the toner as described above is developed in a developing device by a developer. The toner image is visualized by charging with a frictional charging member to obtain a toner image, and the toner image is transferred to a recording material. By fixing, a visible image can be obtained.

  As mentioned above, although embodiment of this invention was described concretely, embodiment of this invention is not limited to said example, A various change can be added.

  Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto. In the following, molecular weight, melting point, glass transition point, and softening point were measured as described above.

<Preparation Example A1 of Amorphous Polyester Resin Fine Particle Dispersion>
In a heat-dried three-necked flask, 0.02 part by mass of dibutyltin oxide and the following composition [A1]
-Composition [A1]-
-Fumaric acid: 1.5 parts by mass-Terephthalic acid: 83.0 parts by mass-Sebacic acid: 15.5 parts by mass-Bisphenol A ethylene oxide 2-mol adduct (molecular weight 316): 25.0 parts by mass-Bisphenol A propylene 1 mol of oxide adduct (molecular weight: 286): 175.0 parts by mass were charged, and the air in the container was placed in an inert atmosphere with nitrogen gas by depressurization, followed by stirring and refluxing at 180 ° C. for 5 hours with mechanical stirring. It was. Thereafter, the temperature is gradually raised to 230 ° C. under reduced pressure, and the mixture is further stirred for 4 hours while maintaining the temperature at 230 ° C .. A crystalline polyester resin was obtained.
This unsaturated amorphous polyester resin has a weight average molecular weight (Mw) of 42,000, a number average molecular weight (Mn) of 6,600, a glass transition point (Tg) of 60.3 ° C., and a softening point of 87 ° C. there were.
In addition, the total content of the polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond in the composition [A1] is 1 component mol%.

Methyl ethyl ketone and isopropyl alcohol are added to a reaction vessel equipped with an anchor blade that gives stirring power, and then the resulting unsaturated amorphous polyester resin is coarsely pulverized with a hammer mill while stirring. A polyester resin solution that was completely dissolved to form an oil phase was obtained. Next, a quantity of dilute aqueous ammonia solution was added dropwise to the stirred oil phase, and this oil phase was added dropwise to ion-exchanged water for phase inversion emulsification, and then the solvent was removed while reducing the pressure with an evaporator. Unsaturated amorphous polyester resin fine particles are generated in the reaction system, and further, ion-exchanged water is added to this dispersion to adjust the solid content to 20% by mass, thereby unsaturated unsaturated polyester resin. A fine particle dispersion [1] was obtained.
The volume-based median diameter of unsaturated amorphous polyester resin fine particles in the obtained unsaturated amorphous polyester resin fine particle dispersion [A1] is measured by an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). It was 185 nm when measured using.

<Preparation Example A2 of Amorphous Polyester Resin Fine Particle Dispersion>
In the preparation example A1 of the amorphous polyester resin fine particle dispersion, the amorphous polyester resin fine particle dispersion [A2] was similarly used except that the following composition [A2] was used instead of the composition [A1]. Was prepared.
-Composition [A2]-
-Fumaric acid: 6.0 parts by mass-Terephthalic acid: 80.0 parts by mass-Sebacic acid: 9.8 parts by mass-2-butene-1,4-diol: 1.2 parts by mass-Bisphenol A ethylene oxide 2 mol Adduct (molecular weight 316): 28.0 parts by mass Bisphenol A propylene oxide 1 mol adduct (molecular weight 286): 175.0 parts by mass The resulting unsaturated amorphous polyester resin fine particle dispersion [A2] The saturated amorphous polyester resin has a weight average molecular weight (Mw) of 38,000, a number average molecular weight (Mn) of 6,500, a clear melting point is not confirmed, and a glass transition point (Tg) of 59.8 ° C. The softening point was 86 ° C.
In addition, the volume-based median diameter of the unsaturated amorphous polyester resin fine particles in the obtained unsaturated amorphous polyester resin fine particle dispersion [A2] is measured by an electrophoretic light scattering photometer “ELS-800” (Otsuka Electronics Co., Ltd.). Measured using a manufactured product, it was 190 nm.
In addition, the total content of the polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond in the composition [A2] is 5 component mol%.

<Preparation Example A3 of Amorphous Polyester Resin Fine Particle Dispersion>
Amorphous polyester resin fine particle dispersion [A3] was prepared in the same manner as in Preparation Example A1 for amorphous polyester resin fine particle dispersion, except that the following composition [A3] was used instead of composition [A1]. Was prepared.
-Composition [A3]-
-Fumaric acid: 12.0 parts by mass-Terephthalic acid: 75.5 parts by mass-2-butene-1,4-diol: 2.5 parts by mass-Sebacic acid: 8.0 parts by mass-Bisphenol A ethylene oxide 2 mols Adduct (molecular weight 316): 27.0 parts by mass Bisphenol A propylene oxide 1 mol adduct (molecular weight 286): 175.0 parts by mass The resulting unsaturated amorphous polyester resin fine particle dispersion [A3] The saturated amorphous polyester resin has a weight average molecular weight (Mw) of 41,000, a number average molecular weight (Mn) of 6,750, no clear melting point, and a glass transition point (Tg) of 59.4 ° C., The softening point was 86 ° C.
In addition, the volume-based median diameter of the unsaturated amorphous polyester resin fine particles in the obtained unsaturated amorphous polyester resin fine particle dispersion [A3] is measured by an electrophoretic light scattering photometer “ELS-800” (Otsuka Electronics Co., Ltd.). ) And 180 nm was measured.
In addition, the total content of the polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond in the composition [A3] is 10 constituent mol%.

<Preparation Example A4 of Amorphous Polyester Resin Fine Particle Dispersion>
Amorphous polyester resin fine particle dispersion [A4] was prepared in the same manner as in Preparation Example A1 of amorphous polyester resin fine particle dispersion, except that the following composition [A4] was used instead of composition [A1]. Was prepared.
-Composition [A4]-
-Fumaric acid: 17.0 parts by mass-Terephthalic acid: 72.5 parts by mass-2-butene-1,4-diol: 2.5 parts by mass-Sebacic acid: 8.0 parts by mass-Bisphenol A ethylene oxide 2 mols Adduct (molecular weight 316): 25.0 parts by mass Bisphenol A propylene oxide 1 mol adduct (molecular weight 286): 175.0 parts by mass The obtained unsaturated amorphous polyester resin fine particle dispersion [A4] The saturated amorphous polyester resin has a weight average molecular weight (Mw) of 35,000, a number average molecular weight (Mn) of 6,200, a clear melting point is not confirmed, and a glass transition point (Tg) of 58.2 ° C., The softening point was 84 ° C.
In addition, the volume-based median diameter of the unsaturated amorphous polyester resin fine particles in the obtained unsaturated amorphous polyester resin fine particle dispersion [A4] is measured by an electrophoretic light scattering photometer “ELS-800” (Otsuka Electronics Co., Ltd.). And 175 nm.
In addition, the total content of the polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond in the composition [A4] is 13 component mol%.

<Preparation Example A5 of Amorphous Polyester Resin Fine Particle Dispersion>
Amorphous polyester resin fine particle dispersion [A5] was prepared in the same manner as in Preparation Example A1 of amorphous polyester resin fine particle dispersion, except that the following composition [A5] was used instead of composition [A1]. Was prepared.
-Composition [A5]-
-Terephthalic acid: 84.0 parts by mass-Sebacic acid: 15.0 parts by mass-Bisphenol A ethylene oxide 2 mol adduct (molecular weight 316): 27.0 parts by mass-Bisphenol A propylene oxide 1 mol adduct (molecular weight 286) 174.0 parts by mass The amorphous polyester resin according to the obtained amorphous polyester resin fine particle dispersion [A5] has a weight average molecular weight (Mw) of 48,000 and a number average molecular weight (Mn) of 6,830. No clear melting point was confirmed, and the glass transition point (Tg) was 59.3 ° C. and the softening point was 88 ° C.
The volume-based median diameter of the amorphous polyester resin fine particles in the obtained amorphous polyester resin fine particle dispersion [A5] is measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). It was 185 nm when measured.
The composition [A5] does not contain a polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond.

<Preparation Example A6 of Amorphous Polyester Resin Fine Particle Dispersion>
In the preparation example A1 of the amorphous polyester resin fine particle dispersion, the amorphous polyester resin fine particle dispersion [A6] was used in the same manner except that the following composition [A6] was used instead of the composition [A1]. Was prepared.
-Composition [A6]-
-Fumaric acid: 0.8 parts by mass-Terephthalic acid: 84.2 parts by mass-Sebacic acid: 15.0 parts by mass-Bisphenol A ethylene oxide 2-mole adduct (molecular weight 316): 25.0 parts by mass-Bisphenol A propylene 1 mol of oxide adduct (molecular weight 286): 175.0 parts by mass The amorphous polyester resin according to the obtained amorphous polyester resin fine particle dispersion [A6] has a weight average molecular weight (Mw) of 42,000, The average molecular weight (Mn) was 6,400, no clear melting point was confirmed, the glass transition point (Tg) was 59.3 ° C., and the softening point was 87 ° C.
In addition, the volume-based median diameter of the amorphous polyester resin fine particles in the obtained amorphous polyester resin fine particle dispersion [A6] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). It was 185 nm when measured.
In addition, the total content of the polyhydric alcohol component / polycarboxylic acid component having a polymerizable unsaturated bond in the composition [A6] is 0.5 constituent mol%.

<Preparation Example B1 of Crystalline Polyester Resin Fine Particle Dispersion>
In Preparation Example A1 of Amorphous Polyester Resin Fine Particle Dispersion, Crystalline Polyester Resin Fine Particle Dispersion [B1] is the same except that the following Composition [B1] is used instead of Composition [A1]. Was prepared.
-Composition [B1]-
-Sebacic acid: 165.0 parts by mass-1,6-hexanediol: 135.0 parts by mass The crystalline polyester resin according to the obtained crystalline polyester resin fine particle dispersion [B1] has a weight average molecular weight (Mw). 14,000, a number average molecular weight (Mn) of 3,800, a clear melting point was confirmed, and the melting point was 88 ° C.
Further, the volume-based median diameter of the crystalline polyester resin fine particles in the obtained crystalline polyester resin fine particle dispersion [B1] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). As a result, it was 185 nm.
The composition [B1] does not contain a diol component / dicarboxylic acid component having a polymerizable unsaturated bond.

<Preparation Example B2 of Crystalline Polyester Resin Fine Particle Dispersion>
Crystalline polyester resin fine particle dispersion [B2] was prepared in the same manner as in Preparation Example B1 of crystalline polyester resin fine particle dispersion, except that the following composition [B2] was used instead of composition [B1]. Prepared.
-Composition [B2]-
Sebacic acid: 164.0 parts by mass Fumaric acid: 0.8 parts by mass 1,6-hexanediol: 134.0 parts by mass 2-butene-1,4-diol: 1.2 parts by mass The crystalline polyester resin according to the crystalline polyester resin fine particle dispersion [B2] has a weight average molecular weight (Mw) of 12,000, a number average molecular weight (Mn) of 4,600 and a clear melting point. It was 85 ° C.
Further, the volume-based median diameter of the crystalline polyester resin fine particles in the obtained crystalline polyester resin fine particle dispersion [B2] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). As a result, it was 175 nm.
In addition, the total content of the diol / dicarboxylic acid having a polymerizable unsaturated bond in the composition [B2] is 1 component mol%.

<Preparation Example B3 of Crystalline Polyester Resin Fine Particle Dispersion>
Crystalline polyester resin fine particle dispersion [B3] was prepared in the same manner as in Preparation Example B1 of crystalline polyester resin fine particle dispersion, except that the following composition [B3] was used instead of composition [B1]. Prepared.
-Composition [B3]-
-Sebacic acid: 162.3 parts by mass-Fumaric acid: 4.2 parts by mass-1,6-hexanediol: 128.0 parts by mass-2-butene-1,4-diol: 5.5 parts by mass The crystalline polyester resin according to the crystalline polyester resin fine particle dispersion [B3] has a weight average molecular weight (Mw) of 11,500, a number average molecular weight (Mn) of 4,300, a clear melting point, and the melting point is It was 87 ° C.
Further, the volume-based median diameter of the crystalline polyester resin fine particles in the obtained crystalline polyester resin fine particle dispersion [B3] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). As a result, it was 170 nm.
The total content of diol / dicarboxylic acid having a polymerizable unsaturated bond in the composition [B3] is 5 component mol%.

<Preparation Example B4 of Crystalline Polyester Resin Fine Particle Dispersion>
Crystalline polyester resin fine particle dispersion [B4] was prepared in the same manner as in Preparation Example B1 of crystalline polyester resin fine particle dispersion, except that the following composition [B4] was used instead of composition [B1]. Prepared.
-Composition [B4]-
Sebacic acid: 161.5 parts by mass Fumaric acid: 3.5 parts by mass 1,6-hexanediol: 120.0 parts by mass 2-butene-1,4-diol: 15.0 parts by mass The crystalline polyester resin according to the crystalline polyester resin fine particle dispersion [B4] has a weight average molecular weight (Mw) of 11,000, a number average molecular weight (Mn) of 4,100 and a clear melting point. It was 84 ° C.
Further, the volume-based median diameter of the crystalline polyester resin fine particles in the obtained crystalline polyester resin fine particle dispersion [B4] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). As a result, it was 180 nm.

In addition, the total content of diol / dicarboxylic acid having a polymerizable unsaturated bond in the composition [B4] is 10 constituent mol%.

<Preparation Example B5 of Crystalline Polyester Resin Fine Particle Dispersion>
In Preparation Example B1 of the crystalline polyester resin fine particle dispersion, the crystalline polyester resin fine particle dispersion [B5] was prepared in the same manner except that the following composition [B5] was used instead of the composition [B1]. Prepared.
-Composition [B5]-
-Sebacic acid: 157.0 parts by mass-Fumaric acid: 7.0 parts by mass-1,6-hexanediol: 120.0 parts by mass-2-butene-1,4-diol: 16.0 parts by mass The crystalline polyester resin according to the crystalline polyester resin fine particle dispersion [B5] has a weight average molecular weight (Mw) of 12,000, a number average molecular weight (Mn) of 4,700 and a clear melting point. It was 80 ° C.
Moreover, the volume-based median diameter of the crystalline polyester resin fine particles in the obtained crystalline polyester resin fine particle dispersion [B5] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). As a result, it was 180 nm.
In addition, the total content of the diol / dicarboxylic acid having a polymerizable unsaturated bond in the composition [B5] is 12 constituent mol%.

<Example of preparation of release agent fine particle dispersion>
Anionic surfactant “Neogen RK” (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass and 60 parts by mass of tribehenate citrate wax (melting point 83.2 ° C.) are put in 240 parts by mass of ion-exchanged water, and 95 ° C. And then sufficiently dispersed with “Ultra Turrax T50” (manufactured by IKA), followed by dispersion treatment with a pressure discharge type gorin homogenizer to obtain a dispersion of release agent fine particles. Ion exchange water was further added to the obtained dispersion to adjust the solid content to 20% by mass, thereby preparing a release agent fine particle dispersion [W]. The volume-based median diameter of the release agent fine particles in the obtained release agent fine particle dispersion [W] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.). It was 240 nm.

<Preparation Example of Black Colorant Fine Particle Dispersion>
8 parts by mass of sodium n-dodecylbenzenesulfonate are mixed and dissolved in 250 parts by mass of ion-exchanged water, and 10 parts by mass of carbon black “Regal 330 (manufactured by Cabot Corporation)” and C.I. I. Pigment Blue 15: 3 was added to 40 parts by mass and sufficiently dispersed with a homogenizer “Ultra Turrax T50” (manufactured by IKA), followed by a dispersion treatment for 20 minutes with an ultrasonic disperser, whereby black colorant fine particles A dispersion was obtained. Further, ion exchange water was added to the obtained dispersion to adjust the solid content to 20% by mass, thereby preparing a colorant fine particle dispersion [K]. The volume-based median diameter of the black colorant fine particles in the obtained colorant fine particle dispersion [K] was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), and was 215 nm. Met.

[Example 1: Toner Production Example 1]
<Aggregation process>
Amorphous polyester resin fine particle dispersion [A1]: 160.0 parts by weight Crystalline polyester resin fine particle dispersion [B1]: 80.0 parts by weight Colorant fine particle dispersion [K]: 25.0 parts by weight Release agent Fine particle dispersion [W]: 15.0 parts by mass Ion-exchanged water: 220 parts by mass was put into a homogenizer “Ultra Turrax T50” (manufactured by IKA) and mixed for 15 minutes while maintaining the temperature at 20 ° C. Next, 0.5 parts by mass of polyaluminum chloride is added as a flocculant, and a 0.3 mol / L aqueous nitric acid solution or 1 mol / L sodium hydroxide is added so that the pH is maintained at 4.1 to 4.3. Mixing and dispersion were continued for 2 hours while appropriately dropping the aqueous solution. The volume-based median diameter in the reaction system was measured with a Coulter Multitizer (manufactured by Beckman Coulter), and it was confirmed that the volume-based median diameter of the aggregated particles was 6.2 μm.
<Aggregation stopping step>
Thereafter, 2.5 parts by mass of ethylenediaminetetraacetic acid 4Na is added, and 1 mol / L of sodium hydroxide is added dropwise so that the pH is maintained at 8 to 8.5. Further adhesion of various fine particles to the surface of the aggregated particles In addition, the aggregation of particles existing in the reaction system was stopped, and aggregated particles having a desired composition were secured.
Immediately after finishing this aggregation stopping step, and after 1 hour, the volume-based median diameter of each aggregated particle was measured with a Coulter Multitizer (manufactured by Beckman Coulter, Inc.), which was 6.2 μm and 6.2 μm, respectively. There was no increase in particle size observed.
<Fusion process>
The reaction system in which the aggregated particles obtained in the aggregation stop step were formed was heated to 70 ° C. and stirred for 60 minutes to fuse the polyester resin fine particles in the aggregated particles, thereby obtaining uncrosslinked fused particles. .
<Crosslinking process>
20 parts by mass of a 20% aqueous solution of potassium persulfate is added to the reaction system in which the uncrosslinked fused particles obtained in the fusion step are formed, the temperature is raised to 75 ° C., and stirring is further performed at 75 ° C. for 120 minutes. Continuous radical polymerization reaction was performed to obtain toner particles having a crosslinked structure.
<Filtering / washing process-drying process>
Thereafter, the reaction system is cooled to 25 ° C. using a multi-tube heat exchanger, and then filtered using a filter paper of “No. 5” (manufactured by Toyo Roshi Kaisha, Ltd.) using a Nutsche suction filter. Washing and filtration were repeated until the pH of the filtrate was 6.5 or less and the electric conductivity was 12 μS / cm or less, and drying was performed for 12 hours by vacuum drying to obtain toner particles [1X].
The resulting toner particles [1X] had a volume-based median diameter (D ₅₀ ) of 6.1 μm and an average circularity of 0.968.
<External additive addition process>
With respect to 100 parts by mass of the obtained toner particles [1X], 2.5 parts by mass of cerium oxide particles (number volume average particle size 0.55 μm), titania particles (treated with dodecyltrimethoxysilane, volume average particle size 30 nm) 0 .8 parts by mass and 1.2 parts by mass of silica particles (hexamethyldisilazane-treated, volume average particle size 100 nm) were added, and the temperature inside the apparatus was adjusted by a “5 L Henschel mixer” (manufactured by Mitsui Miike Chemical Industries, Ltd.) The mixture was mixed for 10 minutes while flowing cooling water so that the temperature was maintained at 45 ° C., and coarse particles were removed from the resulting mixture using a high-speed sieving machine “Hi-Volter NR300” (manufactured by Tokyo Kikai Co., Ltd.) with a mesh opening of 45 μm. Thus, a toner [1] subjected to the external additive treatment was produced.

[Examples 2 to 12: Toner production examples 2 to 12]
In the toner production example 1, toners [2] to [12] were prepared in the same manner except that the types of the amorphous polyester resin fine particle dispersion and the crystalline polyester resin fine particle dispersion used were changed according to Table 1. Obtained. For these toners [2] to [12], the volume-based median diameter and average circularity of the toner particles obtained through the filtration / washing step to the drying step are appended in Table 1.

Example 13 Toner Production Example 13
<Aggregation process>
Amorphous polyester resin fine particle dispersion [A2]: 160.0 parts by weight Crystalline polyester resin fine particle dispersion [B3]: 80.0 parts by weight Colorant fine particle dispersion [K]: 25.0 parts by weight Release agent Fine particle dispersion [W]: 15.0 parts by mass Ion-exchanged water: 220 parts by mass was put into a homogenizer “Ultra Turrax T50” (manufactured by IKA) and mixed for 15 minutes while maintaining the temperature at 20 ° C. Next, 0.5 parts by mass of polyaluminum chloride is added as a flocculant, and a 0.3 mol / L aqueous nitric acid solution or 1 mol / L sodium hydroxide is added so that the pH is maintained at 4.1 to 4.3. Mixing and dispersion were continued for 2 hours while appropriately dropping the aqueous solution. The volume-based median diameter in the reaction system was measured with a Coulter Multitizer (manufactured by Beckman Coulter), and it was confirmed that the volume-based median diameter of the aggregated particles was 6.2 μm.
<Aggregation stopping step>
Thereafter, 2.5 parts by mass of ethylenediaminetetraacetic acid 4Na is added, and 1 mol / L of sodium hydroxide is added dropwise so that the pH is maintained at 8 to 8.5. Further adhesion of various fine particles to the surface of the aggregated particles In addition, the aggregation of particles existing in the reaction system was stopped, and aggregated particles having a desired composition were secured.
Immediately after finishing this aggregation stopping step, and after 1 hour, the volume-based median diameter of each aggregated particle was measured by a Coulter multitizer (manufactured by Beckman Coulter), which was 6.3 μm and 6.3 μm, respectively. There was no increase in particle size observed.
<Crosslinking / fusion process>
20 parts by mass of a 20% aqueous solution of potassium persulfate is added to the reaction system in which the uncrosslinked aggregated particles obtained in the aggregation stopping step are formed, the temperature is raised to 75 ° C., and stirring is continued at 75 ° C. for 240 minutes. Then, radical polymerization reaction and fusion of polyester resin fine particles were performed in parallel to obtain toner particles having a crosslinked structure.
<Filtering / washing process-drying process>
Thereafter, the reaction system is cooled to 25 ° C. using a multi-tube heat exchanger, and then filtered using a filter paper of “No. 5” (manufactured by Toyo Roshi Kaisha, Ltd.) using a Nutsche suction filter. Washing and filtration were repeated until the pH of the filtrate was 6.5 or less and the electric conductivity was 12 μS / cm or less, and the mixture was dried for 12 hours by vacuum drying to obtain toner particles [13X].
The toner particles [13X] thus obtained had a volume-based median diameter (D ₅₀ ) of 6.3 μm and an average circularity of 0.942.
<External additive addition process>
For 100 parts by mass of the obtained toner particles [13X], 2.5 parts by mass of cerium oxide particles (number volume average particle size 0.55 μm), titania particles (treated with dodecyltrimethoxysilane, volume average particle size 30 nm) 0 .8 parts by mass and 1.2 parts by mass of silica particles (hexamethyldisilazane-treated, volume average particle size 100 nm) were added, and the temperature inside the apparatus was adjusted by a “5 L Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.). The mixture is mixed for 10 minutes while flowing cooling water so that the temperature is maintained at 45 ° C., and coarse particles are removed from the resulting mixture by a wind-sieving machine “Hibolter NR300” (manufactured by Tokyo Kikai Co., Ltd.) with a mesh opening of 45 μm. Thus, a toner [13] subjected to the external additive treatment was produced.

Example 14 Toner Production Example 14
<Aggregation process>
Amorphous polyester resin fine particle dispersion [A2]: 160.0 parts by weight Crystalline polyester resin fine particle dispersion [B3]: 80.0 parts by weight Colorant fine particle dispersion [K]: 25.0 parts by weight Release agent Fine particle dispersion [W]: 15.0 parts by mass Ion-exchanged water: 220 parts by mass was put into a homogenizer “Ultra Turrax T50” (manufactured by IKA) and mixed for 15 minutes while maintaining the temperature at 20 ° C. Next, 0.5 parts by mass of polyaluminum chloride is added as a flocculant, and a 0.3 mol / L aqueous nitric acid solution or 1 mol / L sodium hydroxide is added so that the pH is maintained at 4.1 to 4.3. Mixing and dispersion were continued for 2 hours while appropriately dropping the aqueous solution. The volume-based median diameter in the reaction system was measured with a Coulter Multitizer (manufactured by Beckman Coulter), and it was confirmed that the volume-based median diameter of the aggregated particles was 6.2 μm.
Immediately after finishing this agglomeration step, a part of the reaction system was collected, and after 1 hour, the volume-based median diameter of the agglomerated particles was measured with a Coulter Multitizer (Beckman Coulter, Inc.). Was confirmed to increase.
<Crosslinking / fusion process>
20 parts by mass of a 20% aqueous solution of potassium persulfate is added to the reaction system in which the uncrosslinked aggregated particles obtained in the aggregation process are formed, the temperature is raised to 75 ° C., and stirring is continued at 75 ° C. for 240 minutes. Thus, the radical polymerization reaction and the fusion of the polyester resin fine particles were performed simultaneously to obtain toner particles having a crosslinked structure.
<Filtering / washing process-drying process>
Thereafter, the reaction system is cooled to 25 ° C. using a multi-tube heat exchanger, and then filtered using a filter paper of “No. 5” (manufactured by Toyo Roshi Kaisha, Ltd.) using a Nutsche suction filter. Washing and filtration were repeated until the pH of the filtrate was 6.5 or less and the electric conductivity was 12 μS / cm or less, and drying for 12 hours by vacuum drying gave toner particles [14X].
The toner particles [14X] thus obtained had a volume-based median diameter (D ₅₀ ) of 6.9 μm and an average circularity of 0.940. The reason why the volume-based median diameter increased immediately after the completion of the aggregation process seems to be because the aggregation particles continued to grow in the crosslinking / fusion process due to the absence of the addition of the aggregation terminator.
<External additive addition process>
For 100 parts by mass of the obtained toner particles [14X], 2.5 parts by mass of cerium oxide particles (number volume average particle diameter 0.55 μm), titania particles (treated with dodecyltrimethoxysilane, volume average particle diameter 30 nm) 0 .8 parts by mass and 1.2 parts by mass of silica particles (hexamethyldisilazane-treated, volume average particle size 100 nm) were added, and the temperature inside the apparatus was adjusted by a “5 L Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.). The mixture is mixed for 10 minutes while flowing cooling water so that the temperature is maintained at 45 ° C., and coarse particles are removed from the resulting mixture by a wind-sieving machine “Hibolter NR300” (manufactured by Tokyo Kikai Co., Ltd.) with a mesh opening of 45 μm. Thus, a toner [14] subjected to the external additive treatment was produced.

[Comparative Examples 1 and 2: Toner Production Examples 15 and 16]
In Toner Production Example 1, toners [15] and [16] were prepared in the same manner except that the types of amorphous polyester resin fine particle dispersion and crystalline polyester resin fine particle dispersion used were changed according to Table 1. Obtained. For these toners [15] and [16], the volume-based median diameter (D ₅₀ ) and average circularity of the toner particles obtained through the filtration / washing step to the drying step are shown in Table 1.

[Comparative Example 3: Toner Production Example 17]
<Aggregation process>
Amorphous polyester resin fine particle dispersion [A5]: 160.0 parts by weight Crystalline polyester resin fine particle dispersion [B3]: 80.0 parts by weight Colorant fine particle dispersion [K]: 25.0 parts by weight Release agent Fine particle dispersion [W]: 15.0 parts by mass Ion-exchanged water: 220 parts by mass was put into a homogenizer “Ultra Turrax T50” (manufactured by IKA) and mixed for 15 minutes while maintaining the temperature at 20 ° C. Next, 0.5 parts by mass of polyaluminum chloride is added as a flocculant, and a 0.3 mol / L aqueous nitric acid solution or 1 mol / L sodium hydroxide is added so that the pH is maintained at 4.1 to 4.3. Mixing and dispersion were continued for 2 hours while appropriately dropping the aqueous solution. The volume-based median diameter in the reaction system was measured with a Coulter Multitizer (manufactured by Beckman Coulter), and it was confirmed that the volume-based median diameter of the aggregated particles was 6.2 μm.
<Aggregation stopping step>
Thereafter, 2.5 parts by mass of ethylenediaminetetraacetic acid 4Na is added, and 1 mol / L of sodium hydroxide is added dropwise so that the pH is maintained at 8 to 8.5. Further adhesion of various fine particles to the surface of the aggregated particles In addition, the aggregation of particles existing in the reaction system was stopped, and aggregated particles having a desired composition were secured.
Immediately after finishing this aggregation stopping step, and after 1 hour, the volume-based median diameter of each aggregated particle was measured with a Coulter Multitizer (manufactured by Beckman Coulter, Inc.), which was 6.2 μm and 6.2 μm, respectively. There was no increase in particle size observed.
<Fusion process>
The reaction system in which the aggregated particles obtained in the aggregation stopping step were formed was heated to 75 ° C. and stirred for 180 minutes, thereby fusing the polyester resin fine particles in the aggregated particles to obtain toner particles.
<Filtering / washing process-drying process>
Thereafter, the reaction system is cooled to 25 ° C. using a multi-tube heat exchanger, and then filtered using a filter paper of “No. 5” (manufactured by Toyo Roshi Kaisha) using a Nutsche suction filter. Washing and filtration were repeated until the pH of the filtrate was 6.5 or less and the electric conductivity was 12 μS / cm or less, and drying for 12 hours by vacuum drying gave toner particles [17X].
The obtained toner particles [17X] had a volume-based median diameter (D ₅₀ ) of 6.2 μm and an average circularity of 0.965.
<External additive addition process>
For 100 parts by mass of the obtained toner particles [17X], 2.5 parts by mass of cerium oxide particles (number volume average particle size 0.55 μm), titania particles (treated with dodecyltrimethoxysilane, volume average particle size 30 nm) 0 .8 parts by mass and 1.2 parts by mass of silica particles (hexamethyldisilazane-treated, volume average particle size 100 nm) were added, and the temperature inside the apparatus was adjusted by a “5 L Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.). The mixture is mixed for 10 minutes while flowing cooling water so that the temperature is maintained at 45 ° C., and coarse particles are removed from the resulting mixture by a wind-sieving machine “Hibolter NR300” (manufactured by Tokyo Kikai Co., Ltd.) with a mesh opening of 45 μm. Thus, a toner [17] subjected to the external additive treatment was produced.

[Comparative Example 4: Toner Production Example 18]
<Aggregation process>
Amorphous polyester resin fine particle dispersion [A2]: 160.0 parts by weight Crystalline polyester resin fine particle dispersion [B3]: 80.0 parts by weight Colorant fine particle dispersion [K]: 25.0 parts by weight Release agent Fine particle dispersion [W]: 15.0 parts by mass Ion-exchanged water: 220 parts by mass was put into a homogenizer “Ultra Turrax T50” (manufactured by IKA) and mixed for 15 minutes while maintaining the temperature at 20 ° C. Next, 20 parts by mass of a 20% aqueous solution of potassium persulfate was added, the temperature was raised to 50 ° C., and stirring was continued at 50 ° C. for 120 minutes to carry out a radical polymerization reaction. Add 5 parts by mass, and mix for 2 hours while appropriately dropping 0.3 mol / L nitric acid aqueous solution or 1 mol / L sodium hydroxide aqueous solution so that pH is maintained at 4.1 to 4.3 Dispersion continued. The volume-based median diameter in the reaction system was measured with a Coulter Multitizer (manufactured by Beckman Coulter), and it was confirmed that the volume-based median diameter of the aggregated particles was 6.6 μm.
<Aggregation stopping step>
Thereafter, 2.5 parts by mass of ethylenediaminetetraacetic acid 4Na is added, and 1 mol / L of sodium hydroxide is added dropwise so that the pH is maintained at 8 to 8.5. Further adhesion of various fine particles to the surface of the aggregated particles In addition, the aggregation of particles existing in the reaction system was stopped, and aggregated particles having a desired composition were secured.
Immediately after finishing this aggregation stopping step, and after 1 hour, the volume-based median diameter of each aggregated particle was measured by a Coulter multitizer (manufactured by Beckman Coulter, Inc.). There was no increase in particle size observed.
<Fusion process>
The reaction system in which the aggregated particles obtained in the aggregation stop step were formed was heated to 75 ° C. and stirred for 180 minutes to fuse the polyester resin fine particles in the aggregated particles to obtain toner particles.
<Filtering / washing process-drying process>
Thereafter, the reaction system is cooled to 25 ° C. using a multi-tube heat exchanger, and then filtered using a filter paper of “No. 5” (manufactured by Toyo Roshi Kaisha, Ltd.) using a Nutsche suction filter. Washing and filtration were repeated until the pH of the filtrate was 6.5 or less and the electric conductivity was 12 μS / cm or less, and drying for 12 hours by vacuum drying gave toner particles [18X].
The obtained toner particles [18X] had a volume-based median diameter (D ₅₀ ) of 7.0 μm, an average circularity of 0.937, and had an irregular shape.
<External additive addition process>
For 100 parts by mass of the obtained toner particles [18X], 2.5 parts by mass of cerium oxide particles (number volume average particle size 0.55 μm), titania particles (treated with dodecyltrimethoxysilane, volume average particle size 30 nm) 0 .8 parts by mass and 1.2 parts by mass of silica particles (hexamethyldisilazane-treated, volume average particle size 100 nm) were added, and the temperature inside the apparatus was adjusted by a “5 L Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.). The mixture is mixed for 10 minutes while flowing cooling water so that the temperature is maintained at 45 ° C., and coarse particles are removed from the resulting mixture by a wind-sieving machine “Hibolter NR300” (manufactured by Tokyo Kikai Co., Ltd.) with a mesh opening of 45 μm. Thus, a toner [18] subjected to the external additive treatment was produced.

[Evaluation 1: Evaluation of heat-resistant storage stability]
For each of the toners [1] to [18], 0.5 g of the toner is put in a 10 mL glass bottle with an inner diameter of 21 mm, the lid is closed, and the mixture is shaken 600 times with a tap denser “KYT-2000” (manufactured by Seishin Enterprise). The lid was removed, and the mixture was left in an environment of a temperature of 57 ° C. and a humidity of 35% RH for 2 hours. Next, place the toner on a 48 mesh (350 μm aperture) sieve with care not to crush it, set it on a powder tester (manufactured by Hosokawa Micron), fix it with a press bar and knob nut, and achieve a vibration strength of 1 mm feed width. After adjusting and applying vibration for 10 seconds, the amount of residual toner remaining on the sieve was measured, the toner aggregation rate was calculated by the following formula (1), and evaluated according to the following evaluation criteria. The results are shown in Table 1.
Formula (1): toner aggregation rate (mass%) = {remaining toner amount (g) /0.5 (g)} × 100
-Evaluation criteria-
A: The toner aggregation rate is less than 10% by mass (excellent).
A: The toner aggregation rate is 10% by mass or more and less than 20% by mass (good).
Δ: The toner aggregation rate is 20% by mass or more and less than 30% by mass (possible).
X: The toner aggregation rate is 20% by mass or more (defect).

[Developer Preparation Examples 1-18]
For the produced toners [1] to [18], a ferrite carrier having a volume-based median diameter of 60 μm coated with a silicone resin is mixed so that the toner concentration becomes 6% by mass, and the developers [1] to [1] 18] was prepared.

[Evaluation 2: Evaluation of low-temperature fixability]
For the developers [1] to [18], in the full-color copier “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) of a commercially available composite printer, the surface temperature of the fixing heat roller is set to 100 to 210 ° C. Fixing to fix a solid image with a toner adhesion amount of 10 mg / cm ² , width 20 mm and length 50 mm on A4 (basis weight 80 g / m ² ) plain paper using a modified one that can be changed within the range The experiment was repeated while changing the set fixing temperature from 100 ° C. in increments of 5 ° C.
The printed matter obtained in the fixing experiment related to each fixing temperature is folded by a folding machine so as to apply a load to the solid image, and 0.35 MPa of compressed air is blown onto the printed image. The five fixing levels shown in the evaluation criteria were ranked, and the fixing temperature in the fixing experiment of rank 3 was set as the minimum fixing temperature, and this was used as an index of low-temperature fixing property. The results are shown in Table 1.
-Evaluation criteria-
Rank 5: No crease.
Rank 4: There is peeling according to some creases.
Rank 3: There is fine linear peeling according to the crease.
Rank 2: There is a thick linear peeling according to the crease.
Rank 1: There is large peeling.

[Evaluation 3: Evaluation of high-temperature offset resistance]
For developers [1] to [18], in the full-color copier “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) of a commercially available composite printer, the surface temperature of the fixing heat roller is set to 100 to 180 ° C. Fixing to fix a solid image with a toner adhesion amount of 10 mg / cm ² , width 20 mm and length 50 mm on A4 (basis weight 80 g / m ² ) plain paper using a modified one that can be changed within the range The experiment was repeated while changing the set fixing temperature from 100 ° C. in increments of 5 ° C.
The fixing temperature in the fixing experiment relating to the lowest temperature at which image staining due to high temperature offset was observed was measured as the high temperature offset temperature. The results are shown in Table 1. “Non-occurring” in Table 1 means that image contamination due to high temperature offset was not observed even at 210 ° C.

[Evaluation 4: Glossiness]
For developers [1] to [18], in a full-color copier “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) of a commercially available composite printer, the surface temperature of the fixing heat roller is set to 100 to 210 ° C. Using a modified version so that it can be changed within the range, and the surface temperature of the fixing heat roller is set to the higher one of the low temperature offset temperature and the lower limit fixing temperature (minimum fixing temperature) Then, a solid image (100% image) with a toner adhesion amount of 10 mg / cm ² was formed on an art-coated paper having a thickness of 250 g / m ² , and the 75% gloss of the 100% image using “Gardner micro-gloss 75 °”. Was measured as the glossiness. The results are shown in Table 1. In addition, when glossiness is 60-80, it is judged that it is a pass practically as there is moderate glossiness and there is no glare feeling. On the other hand, if the glossiness exceeds 80, it is determined that the glossiness is not suitable for practical use because of a sense of incongruity due to the glare.

[Evaluation 5: Image quality evaluation (GI value)]
For the developers [1] to [18], in the full-color copier “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) of a commercially available composite printer, the surface temperature of the fixing heat roller is set to 100 to 210 ° C. Using a modified version so that it can be changed within the range, and the surface temperature of the fixing heat roller is set to the higher one of the low temperature offset temperature and the lower limit fixing temperature (minimum fixing temperature) Then, a solid image (100% image) having a toner adhesion amount of 10 mg / cm ² and a 50% flat screen image were formed on an art-coated paper having a thickness of 250 g / m ² , and the GI value of the 50% flat screen image portion was determined. And an image analysis system “GI-es-8500AAC” (manufactured by NATIONAL INSTRUMENT). The results are shown in Table 1. If the GI value is 0.25 or less, it is determined that the image has less roughness and can be used practically.

[Evaluation 6: Evaluation of filming]
For developer [1] to [18], image formation is performed with the transfer current in the photosensitive drum being OFF in a full-color copier “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) of a commercially available composite printer. The image forming operation for outputting a halftone image with a toner adhesion amount of 0.1 mg / cm ² on A4 (basis weight 80 g / m ² ) plain paper was used, and the transfer current was turned off. The procedure was repeated 5,000 times. Thereafter, the surface of the photosensitive drum was observed, and the state was evaluated according to the following evaluation criteria. The results are shown in Table 1.
-Evaluation criteria-
A: No filming is present. O: Filming is slightly observed at the end of the photosensitive drum. Δ: Filming is observed slightly at the end other than the end of the photosensitive drum, but the image is not affected. Filming is seen and the resulting image is unacceptable

Claims (4)

A method for producing a toner for developing an electrostatic image comprising toner particles containing a binder resin including a polyester resin having at least a crosslinked structure,
(A-1) Step of producing fine particle aqueous medium dispersion with crystalline polyester resin (a-2) Fine particle aqueous medium dispersion with amorphous polyester resin containing polymerizable unsaturated double bond Step (b) In the aqueous medium, after undergoing a step of aggregating at least the fine particles of the crystalline polyester resin and the fine particles of the amorphous polyester resin containing the polymerizable unsaturated bond to form aggregated particles,
Without providing a separate step of adding resin fine particles for the shell layer,
(C) A method for producing a toner for developing an electrostatic charge image, comprising a step of producing a polyester resin having a crosslinked structure by causing a radical polymerization initiator to act on the aggregated particles to perform a radical polymerization reaction.   2. The electrostatic charge according to claim 1, wherein at least a part of the fine particles of the crystalline polyester resin to be aggregated in the step (b) comprises fine particles containing a crystalline polyester resin containing a polymerizable unsaturated bond. A method for producing toner for image development. Between the step (b) and the step (c),
3. The method according to claim 1, further comprising a step of adding an aggregation terminator for suppressing aggregation of the fine particles of the crystalline polyester resin and the fine particles of the amorphous polyester resin containing a polymerizable unsaturated bond. A method for producing a toner for developing electrostatic images.   An electrostatic image developing toner obtained by the method for producing an electrostatic image developing toner according to claim 1.