JP2018123249A - Method for producing crystalline polyester resin aqueous dispersion and method for producing toner for electrostatic charge image development - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a crystalline polyester resin aqueous dispersion which has a small particle diameter and sharp grain size distribution, and to provide a method for producing a toner.SOLUTION: A method for producing a crystalline polyester resin aqueous dispersion includes: a dissolution step of dissolving a crystalline polyester resin in a solvent; a neutralization step of adding a neutralization agent to a solution obtained in the dissolution step; and a phase inversion emulsification step of dropping an aqueous medium to the neutralization liquid obtained in the neutralization step, and phase inversion emulsifies the neutralization liquid, where in the phase inversion emulsification step, a ratio of water in a solvent contained in the neutralization liquid immediately before the drop of the aqueous medium is in a range of 12-50 mass%, and the phase inversion emulsification step is performed at a temperature lower than a melting point of the crystalline polyester resin by 20°C or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a crystalline polyester resin aqueous dispersion and a method for producing an electrostatic charge image developing toner. More specifically, the present invention provides a method for producing a crystalline polyester resin aqueous dispersion having a small particle size and a sharp particle size distribution, and a fixing property produced using the crystalline polyester resin aqueous dispersion. The present invention relates to a method for producing a good toner for developing electrostatic images.

  In recent years, for the purpose of increasing the printing speed, expanding the type of paper, reducing the environmental load, etc., it is required to reduce the thermal energy when fixing the toner image. In order to reduce the thermal energy at the time of fixing the toner image, a technique capable of improving the low-temperature fixability of the electrostatic image developing toner (hereinafter also simply referred to as toner) is required, and one of the means for achieving this. As a method, a method using a crystalline resin such as crystalline polyester excellent in sharp melt property as a binder resin is known.

  Since this crystalline resin is finely dispersed in the toner, it is easy to obtain an effect of uniformly softening the whole toner at the time of fixing. However, in order to finely disperse in the toner, a small particle size and a particle size distribution are obtained. A sharp dispersion of crystalline resin particles is required. A phase inversion emulsification method is known as a method for obtaining a resin particle dispersion (see, for example, Patent Document 1 and Patent Document 2).

  Patent Document 1 discloses phase inversion emulsification of amorphous polyester, but unlike amorphous polyester, crystalline polyester having a clear melting point has molecular mobility at a temperature near the melting point. Will change drastically. Therefore, if the phase inversion emulsification temperature of the crystalline polyester is not appropriate, problems such as an increase in the particle size of the emulsified dispersion and an increase in the particle size distribution occur.

  On the other hand, Patent Document 2 discloses phase inversion emulsification of crystalline polyester. However, since the amount of water in the solution before phase inversion emulsification is small, the neutralizing agent is poorly mixed and the acidic groups of the crystalline polyester resin are not sufficiently neutralized, resulting in an increase in the diameter of the emulsified particles. There's a problem.

  Therefore, when a toner is manufactured using a dispersion of crystalline resin fine particles obtained by the methods described in Patent Document 1 and Patent Document 2, it is difficult to manufacture a toner having good fixability.

JP 2013-97307 A JP 2010-77319 A

  The present invention has been made in consideration of the above problems and circumstances, and the solution is to provide a method for producing an aqueous dispersion of a crystalline polyester resin having a small particle size and a sharp particle size distribution. Is to provide.

  Another object of the present invention is to provide a method for producing a toner having good fixability.

In order to solve the above-mentioned problems, the present inventors, in the process of examining the cause of the above-mentioned problem, set the water content in the solution and the phase inversion emulsification temperature immediately before phase inversion emulsification, that is, immediately before dropping of the aqueous medium. It has been found that the above problems can be solved by controlling and carrying out phase inversion emulsification, and the present invention has been completed.
That is, the said subject which concerns on this invention is solved by the following means.

1. A dissolution step of dissolving the crystalline polyester resin in a solvent;
A neutralizing step of adding a neutralizing agent to the solution obtained in the dissolving step;
A phase inversion emulsification step in which an aqueous medium is added dropwise to the neutralization liquid obtained in the neutralization step to phase inversion emulsify,
In the phase inversion emulsification step, the ratio of water in the solvent contained in the neutralization solution immediately before the dropping of the aqueous medium is in the range of 12 to 50% by mass,
A method for producing a crystalline polyester resin aqueous dispersion, wherein the phase inversion emulsification step is performed at a temperature of 20 ° C. or lower than the melting point of the crystalline polyester resin.

  2. 2. The method for producing an aqueous crystalline polyester resin dispersion according to claim 1, wherein the dissolving step is performed at a temperature not lower than 20 ° C. lower than the melting point of the crystalline polyester resin.

  3. 3. The method for producing an aqueous crystalline polyester resin dispersion according to item 1 or 2, wherein the neutralization step is performed at a temperature of 20 ° C. or lower than the melting point of the crystalline polyester resin.

4). The volume average particle diameter of the crystalline polyester resin particles constituting the crystalline polyester resin aqueous dispersion is in the range of 50 to 500 nm, and
The coefficient of variation (CV value) of the crystalline polyester resin particles is in the range of 10 to 60%, and the crystalline polyester resin aqueous solution according to any one of items 1 to 3, A method for producing a dispersion.

  5. The said melt | dissolution process is a process of dissolving 50-300 mass parts of said crystalline polyester resins in 100 mass parts of said solvents, The 1st term | claim characterized by the above-mentioned. A method for producing an aqueous dispersion of crystalline polyester resin.

  6). The crystalline polyester resin contains a styrene / acryl modified polyester resin formed by bonding a crystalline polyester resin segment and a styrene / acrylic resin segment, any one of items 1 to 5 The manufacturing method of crystalline polyester resin aqueous dispersion as described in claim | item.

  7). The crystalline polyester resin particles contained in the crystalline polyester resin aqueous dispersion according to any one of items 1 to 6 have a step of aggregating and fusing in an aqueous medium. A method for producing a toner for developing an electrostatic image.

According to the present invention, it is possible to provide a method for producing an aqueous crystalline polyester resin dispersion having a small particle size and a sharp particle size distribution.
In addition, according to the present invention, by using a crystalline polyester resin aqueous dispersion having a small particle size and a sharp particle size distribution, the toner is produced, whereby the dispersibility of the crystalline polyester resin inside the toner is improved. It is possible to provide a method for producing a toner that is improved and has good fixability.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

In general, the phase inversion emulsification method involves dissolving a resin in a solvent and then adding a neutralizing agent to ionize the acidic group of the resin to drop an aqueous medium to invert the aqueous phase and the oil phase, An emulsion is prepared.
In the system immediately before the dropping of the aqueous medium, water that has diluted the neutralizing agent or water contained in the solvent already exists, but the amount of water in the system before phase inversion emulsification is low. If the amount is too large, a part of the oil phase inverts into oil droplets (emulsified dispersed particles) before dropping the aqueous medium in the phase inversion emulsification step, and the phase inversion process is not uniform. It is considered that the emulsion dispersion has a wide particle size distribution.

  On the other hand, even if the amount of water in the system before phase inversion emulsification is too small, the miscibility of the neutralizing agent decreases, the carboxy groups in the polyester resin are not fully neutralized, and the particle size of the crystalline polyester resin particles Therefore, it is considered that the emulsion dispersion has a wide particle size distribution.

  In addition, the crystalline polyester resin greatly increases the mobility of molecules on the higher temperature side than the temperature near its melting point. If the molecular mobility at the oil-water interface during phase inversion emulsification is not uniform (both those dissolved in the solvent and those not dissolved at the molecular level), phase inversion does not occur uniformly, and as a result It is considered that only an emulsified dispersion having a wide particle size distribution can be obtained.

On the other hand, in the present invention, by controlling the water content in the system immediately before phase inversion emulsification, i.e. immediately before dropping of the aqueous medium, by performing phase inversion emulsification, the state of the entire oil-water interface in the system becomes uniform, An emulsified dispersion having a small particle size and a sharp particle size distribution can be obtained.
Furthermore, in the present invention, by performing the phase inversion emulsification step at a temperature of 20 ° C. lower than the melting point of the crystalline polyester resin, sufficient molecular mobility that does not inhibit phase inversion can be ensured, The emulsion-dispersed liquid can be obtained with a uniform oil-water interface state, a small particle size, and a sharp particle size distribution.

  Thus, in the phase inversion emulsification step, the present invention controls the water content in the system immediately before the dropping of the aqueous medium and the phase inversion emulsification temperature, thereby reducing the particle size and the particle size distribution. A sharp emulsified dispersion can be obtained.

Flow chart showing a series of steps of a method for producing a crystalline polyester resin aqueous dispersion

[Method for producing crystalline polyester resin aqueous dispersion]
The method for producing a crystalline polyester resin aqueous dispersion of the present invention includes a dissolution step of dissolving a crystalline polyester resin in a solvent, a neutralization step of adding a neutralizing agent to the solution obtained in the dissolution step, A phase change emulsification step in which an aqueous medium is dropped into the neutralization solution obtained in the neutralization step and phase inversion emulsification is included in the neutralization solution immediately before the addition of the aqueous medium in the phase inversion emulsification step. The ratio of water in the solvent is within a range of 12 to 50% by mass, and the phase inversion emulsification step is performed at a temperature of 20 ° C. or lower than the melting point of the crystalline polyester resin. . This feature is a technical feature common to the claimed invention.

  As an embodiment of the present invention, since it is desirable to uniformly disperse the crystalline polyester resin at a molecular level in a solvent, the dissolution step is performed at a temperature equal to or higher than a temperature 20 ° C. lower than the melting point of the crystalline polyester resin. It is preferable to carry out with.

  Furthermore, in order to allow the neutralizing agent to uniformly act on the entire crystalline polyester resin when the neutralizing agent is added, it is desirable that the crystalline polyester resin is uniformly dispersed in the solvent at the molecular level. The neutralization step is preferably performed at a temperature equal to or higher than a temperature 20 ° C. lower than the melting point of the crystalline polyester resin.

  Further, from the viewpoint of improving the dispersibility of the crystalline polyester resin particles in the toner, and hence the fixability of the toner produced using the crystalline polyester resin aqueous dispersion of the present invention, the crystalline polyester resin aqueous dispersion is constituted. It is preferable that the volume average particle diameter of the crystalline polyester resin particles to be performed is in the range of 50 to 500 nm, and the coefficient of variation (CV value) of the crystalline polyester resin particles is in the range of 10 to 60%. .

  From the viewpoint of manifesting the effects of the present invention, the dissolving step is preferably a step of dissolving 50 to 300 parts by mass of the crystalline polyester resin in 100 parts by mass of the solvent.

  In order to improve the fixing property and the high temperature offset property, it is preferable to use a styrene / acrylic resin having a property of high elasticity at a high temperature as a binder resin of the toner, and the styrene / acrylic resin and the crystalline polyester. From the viewpoint of increasing the affinity of the resin, the crystalline polyester resin preferably contains a styrene / acryl modified polyester resin formed by bonding a crystalline polyester resin segment and a styrene / acryl resin segment.

  The crystalline polyester resin aqueous dispersion is suitably used for a toner production method including a step of aggregating and fusing the crystalline polyester resin particles contained in the crystalline polyester resin aqueous dispersion in an aqueous medium. It is done.

  Hereinafter, constituent elements of the present invention (each component and process used in the present invention), and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Method for producing crystalline polyester resin aqueous dispersion]
The method for producing an aqueous dispersion of crystalline polyester resin of the present invention includes a dissolving step (step 1) for dissolving the crystalline polyester resin in a solvent, and a neutralizing step for adding a neutralizing agent to the solution obtained in the dissolving step. (Step 2), having a phase inversion emulsification step (Step 3) in which an aqueous medium is dropped into the neutralized liquid obtained in the neutralization step and phase inversion emulsification is performed. The ratio of water in the solvent contained in the neutralization liquid is in the range of 12 to 50% by mass, and step 3 is performed at a temperature equal to or higher than a temperature 20 ° C. lower than the melting point of the crystalline polyester resin. Features.

  In the present invention, the aqueous polyester resin dispersion refers to a liquid material in which the polyester resin dispersible in the aqueous medium in the present invention is dispersed in the aqueous medium. Here, the aqueous medium is a medium composed of a liquid containing water, and may contain an organic solvent and a basic compound.

FIG. 1 is a flowchart showing a series of steps of a method for producing a crystalline polyester resin aqueous dispersion. The method for producing a crystalline polyester resin aqueous dispersion of the present invention essentially includes step 1 (step S11) to step 3 (step S13), and after step 3 (step S13), a desolubilization step (step 4 ( Step S14)) may be provided and preferably comprises step 4 (step S14).
Hereinafter, each of the steps 1 to 4 will be described.

<< Dissolution process (process 1) >>
The dissolving step (step 1) is a step of dissolving the crystalline polyester resin in a solvent. In this step, a crystalline polyester resin solution (hereinafter, also referred to as “CPES solution”) is obtained by dissolving the crystalline polyester resin in a solvent.
The crystalline polyester resin that can be used in this step is not particularly limited.

  The crystalline polyester resin used in this step preferably has an acid group at the end of the molecular chain from the viewpoint of facilitating emulsification of the resin particle dispersion and enhancing the dispersion stability. Examples of the acid group include a carboxy group, a sulfonic acid group, a phosphonic acid group, a sulfinic acid group, and the like, from the point that the dispersion stability of the resin can be obtained, and the heat-resistant storage stability of the obtained toner can be improved. A carboxy group is preferred.

  The content of the crystalline polyester resin having an acid group facilitates emulsification of the resin particle dispersion, can improve the dispersion stability, and further improves the dot reproducibility and charging stability of the obtained toner. From the point which can do, etc., Preferably it is in the range of 80-100 mass parts with respect to 100 mass parts of resin which comprises the resin particle in crystalline polyester resin aqueous dispersion, More preferably, it exists in the range of 90-100 mass parts. More preferably, it is in the range of 95 to 100 parts by mass, particularly preferably 100 parts by mass. The raw material monomer of the crystalline polyester resin having an acid group is not particularly limited, and any alcohol component and any carboxylic acid component can be used. Hereinafter, based on these points, the crystalline polyester resin component will be described.

[Crystalline polyester resin]
In the present invention, the crystalline polyester resin is a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). A resin having a clear endothermic peak. Specifically, the “clear endothermic peak” means a peak in which the half-value width of the endothermic peak is within 15 ° C. when measured at a heating rate of 10 ° C./min in differential scanning calorimetry (DSC). means.

By including the crystalline polyester resin in the toner particles, the sharp melt property of the toner particles can be improved, and the low-temperature fixing property and the fixing separation property can be improved.
The polyvalent carboxylic acid used for the preparation of the crystalline polyester resin is a compound containing two or more carboxy groups in one molecule, and can form a crystalline resin by polycondensation reaction. That's fine.

  Specifically, for example, saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid and n-dodecyl succinic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; phthalates Aromatic dicarboxylic acids such as acid, isophthalic acid and terephthalic acid; trivalent or higher polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid; and anhydrides of these carboxylic acid compounds or alkyl esters having 1 to 3 carbon atoms Etc. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The polyhydric alcohol used for the preparation of the crystalline polyester resin is a compound containing two or more hydroxy groups in one molecule and can form a crystalline resin by polycondensation reaction. Good.

  Specifically, for example, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1 , 8-octanediol, neopentyl glycol, 1,4-butenediol, and other aliphatic diols; trihydric or higher polyhydric alcohols such as glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These may be used individually by 1 type and may be used in combination of 2 or more type.

(Melting point of crystalline polyester resin)
The melting point of the crystalline polyester resin is preferably less than 20 ° C. lower than the boiling point of the solvent used, and from the viewpoint that sufficient low-temperature fixability can be obtained, it is within the range of 60 to 90 ° C. Preferably, it is 70-85 degreeC. The melting point of the crystalline polyester resin can be controlled by the resin composition.

(Measuring method of melting point of crystalline polyester resin)
As a method for measuring the melting point of the crystalline polyester resin, a differential scanning calorimeter (DSC) “Diamond DSC” (manufactured by Perkin Elmer) was used, and the temperature was raised from room temperature (25 ° C.) to 150 ° C. at an elevation rate of 10 ° C./min. The first temperature rising process in which isothermal holding is performed at 150 ° C. for 5 minutes, the cooling process in which cooling is performed from 150 ° C. to 0 ° C. at a cooling rate of 10 ° C./min, and isothermal holding at 5 ° C. for 5 minutes, The measurement is performed under the measurement conditions (temperature increase / cooling conditions) through the second temperature increase process in which the temperature is increased from 0 ° C. to 150 ° C. at / min. The measurement is performed by sealing 3.0 mg of crystalline polyester resin in an aluminum pan and setting it in a sample holder of a differential scanning calorimeter “Diamond DSC”. An empty aluminum pan is used as a reference, and in the above measurement, the temperature at the top of the endothermic peak in the second temperature raising step can be the melting point of the crystalline polyester.

(Weight average molecular weight, number average molecular weight of crystalline polyester resin)
The weight average molecular weight (Mw) of the crystalline polyester resin is not particularly limited, but is preferably in the range of 5,000 to 100,000, and more preferably in the range of 5,000 to 50,000. If the weight average molecular weight (Mw) is 5000 or more, the heat-resistant storage property of the toner can be improved, and if it is 100000 or less, the low-temperature fixability can be further improved. The number average molecular weight (Mn) of the resin is preferably 1000 to 15000 from the viewpoint of low-temperature fixability and gloss stability.

(Measurement method of weight average molecular weight and number average molecular weight of resin)
The molecular weight (weight average molecular weight and number average molecular weight) of each resin (amorphous polyester resin, hybrid amorphous polyester resin, crystalline polyester resin, hybrid crystalline polyester resin, etc.) by gel permeation chromatography (GPC) is Measurement is performed as follows. That is, using an apparatus “HLC-8120GPC” (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. Run at 0.2 mL / min. The measurement sample (resin) is dissolved in tetrahydrofuran so as to have a concentration of 1 mg / mL. The solution is prepared by performing treatment at room temperature for 5 minutes using an ultrasonic disperser. Next, a sample solution is obtained by processing with a membrane filter having a pore size of 0.2 μm, 10 μL of this sample solution is injected into the apparatus together with the carrier solvent, and detected using a refractive index detector (RI detector). The molecular weight distribution of the measurement sample is calculated based on a calibration curve created using monodisperse polystyrene standard particles. Ten points are used as polystyrene for the calibration curve measurement.

(Method for producing crystalline polyester resin)
The method for producing the crystalline polyester resin is not particularly limited, and the resin can be produced by polycondensation (esterification) of the polyvalent carboxylic acid and the polyhydric alcohol using a known esterification catalyst. it can.

  Catalysts that can be used in the production include alkali metal compounds such as sodium and lithium; compounds containing Group 2 elements such as magnesium and calcium; aluminum, zinc, manganese, antimony, titanium, tin, zirconium, germanium, and the like Metal compounds; phosphorous acid compounds; phosphoric acid compounds; and amine compounds. Considering availability, dibutyltin oxide, tin octylate, tin dioctylate, salts thereof, tetranormal butyl titanate (tetrabutyl orthotitanate), tetraisopropyl titanate (titanium tetraisopropoxide), tetramethyl titanate, etc. Is preferably used. You may use these individually by 1 type or in combination of 2 or more types.

The temperature of polycondensation (esterification) is not particularly limited, but is preferably 150 to 250 ° C. The time for polycondensation (esterification) is not particularly limited, but is preferably 0.5 to 15 hours. During the polycondensation, the reaction system may be depressurized as necessary.
Moreover, as a crystalline polyester resin, the hybrid crystalline polyester resin demonstrated below can be used.

[Hybrid crystalline polyester resin]
A hybrid crystalline polyester resin (also abbreviated as a hybrid resin) is a resin in which a crystalline polyester resin segment and an amorphous resin segment are chemically bonded.
The crystalline polyester resin segment refers to a molecular chain constituting the crystalline polyester resin. The amorphous resin segment refers to a molecular chain that constitutes an amorphous resin (a resin that cannot take a crystal structure).

(Weight average molecular weight of hybrid resin)
The weight average molecular weight (Mw) of the hybrid resin is preferably in the range of 5,000 to 100,000, and preferably 7,000 to 50,000, from the viewpoint of ensuring both sufficient low-temperature fixability and excellent long-term storage stability. More preferably, it is especially preferable in the range of 8000-40000. By setting the weight average molecular weight (Mw) of the hybrid resin to 100000 or less, sufficient low-temperature fixability can be obtained. On the other hand, by setting the weight average molecular weight (Mw) of the hybrid resin to 5000 or more, when the hybrid resin and the amorphous resin are used together as a binder resin during toner storage, the compatibility between these resins is excessive. Image progression due to fusion between toners can be effectively suppressed.

(Crystalline polyester resin segment in hybrid resin)
The crystalline polyester resin segment is a portion derived from a known polyester resin obtained by a polycondensation reaction between a divalent or higher carboxylic acid (polyvalent carboxylic acid) and a divalent or higher alcohol (polyhydric alcohol). In the differential scanning calorimetry of the toner, it refers to a resin segment having a clear endothermic peak rather than a stepwise endothermic change.

  The crystalline polyester resin segment is not particularly limited as long as it is defined above. For example, this resin (or resin having a structure in which other components are copolymerized with a main chain of a crystalline polyester resin segment, or a resin having a structure in which a crystalline polyester resin segment is copolymerized with a main chain composed of other components) If the toner containing the resin has a clear endothermic peak as described above, the resin corresponds to a hybrid resin having a crystalline polyester resin segment in the present invention.

  Further, the valences of the polyvalent carboxylic acid component and the polyhydric alcohol component are each preferably 2 to 3, particularly preferably 2 respectively. , Dicarboxylic acid component, 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. By using a linear type, there is an advantage that crystallinity is improved. 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, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. Acid (dodecanedioic acid), 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid (tetradecanedioic acid), 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecane Examples thereof include dicarboxylic acid and 1,18-octadecanedicarboxylic acid, and these lower alkyl esters and acid anhydrides can also be used.

Among the above aliphatic dicarboxylic acids, aliphatic dicarboxylic acids having 6 to 12 carbon atoms are preferable because the above-described effects are easily obtained.
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.

  As the dicarboxylic acid component for forming the crystalline polyester resin segment, the content of the aliphatic dicarboxylic acid is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol%. % Or more, and particularly preferably 100 mol%. When the content of the aliphatic dicarboxylic acid in the dicarboxylic acid component is 50 mol% or more, the crystallinity of the crystalline polyester resin segment can be sufficiently ensured.

  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 aliphatic diol, a linear diol is preferably used. By using a linear type, there is an advantage that crystallinity is improved. A diol component may be used individually by 1 type and may be used 2 or more types.

  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-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples include octadecanediol and 1,20-eicosanediol.

Among the aliphatic diols, the diol component is preferably an aliphatic diol having 2 to 12 carbon atoms, more preferably an aliphatic diol having 6 to 12 carbon atoms, because the above-described effects are easily obtained.
Examples of the diol other than the aliphatic diol used as necessary include a diol having a double bond and a diol having a sulfonic acid group. Specifically, examples of the diol having a double bond include 2 -Butene-1,4-diol, 3-hexene-1,6-diol, 4-octene-1,8-diol and the like.

  As the diol component for forming the crystalline polyester resin segment, the content of the aliphatic diol is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more. And particularly preferably 100 mol%. When the content of the aliphatic diol in the diol component is 50 mol% or more, the crystallinity of the crystalline polyester resin segment can be ensured. As a result, the toner produced using the dispersion of the present invention has excellent low-temperature fixability and excellent gloss of the finally formed image.

  The use ratio of the diol component to the dicarboxylic acid component is such that the equivalent ratio [OH] / [COOH] of the hydroxy group [OH] of the diol component to the carboxy group [COOH] of the dicarboxylic acid component is 1.5 / 1. It is preferable to be within a range of ˜1 / 1.5, and more preferably within a range of 1.2 / 1 to 1 / 1.2.

  The method for forming the crystalline polyester resin segment is not particularly limited, and the segment is formed by polycondensation (esterification) of the polyvalent carboxylic acid and the polyhydric alcohol using a known esterification catalyst. Can do.

  Catalysts that can be used in the production of the crystalline polyester resin segment include alkali metal compounds such as sodium and lithium; group 2 metal compounds of the periodic table of elements such as magnesium and calcium; aluminum, zinc, manganese, and antimony Metal compounds such as titanium, tin, zirconium and germanium; phosphorous acid compounds; phosphoric acid compounds; and amine compounds.

  Specifically, examples of the tin compound include dibutyltin oxide, tin octylate, tin dioctylate, and salts thereof. Titanium compounds include titanium alkoxides such as tetranormal butyl titanate, tetraisopropyl titanate, tetramethyl titanate, and tetrastearyl titanate; titanium acylates such as polyhydroxy titanium stearate; titanium tetraacetylacetonate, titanium lactate, titanium triethanolamine Examples thereof include titanium chelates such as nates. Examples of germanium compounds include germanium dioxide. Furthermore, examples of the aluminum compound include oxides such as polyaluminum hydroxide, aluminum alkoxide, and the like, and tributylaluminate and the like can be given. You may use these individually by 1 type or in combination of 2 or more types.

  The polymerization temperature is not particularly limited, but is preferably in the range of 150 to 250 ° C. Moreover, although superposition | polymerization time is not specifically limited, It is preferable to exist in the range of 0.5 to 10 hours. During the polymerization, the pressure in the reaction system may be reduced as necessary.

The constituent component and the content ratio of each segment in the hybrid resin can be specified by, for example, NMR measurement or methylation reaction Py-GC / MS measurement.
Here, the hybrid resin includes an amorphous resin segment described in detail below in addition to the crystalline polyester resin segment. The hybrid resin may be in any form such as a block copolymer or a graft copolymer as long as it includes the crystalline polyester resin segment and the amorphous resin segment, and is a graft copolymer. preferable. By using a graft copolymer, the orientation of the crystalline polyester resin segment can be easily controlled, and sufficient crystallinity can be imparted to the hybrid resin.

Furthermore, from the above viewpoint, it is preferable that the crystalline polyester resin segment is grafted with the amorphous resin segment as a main chain. That is, the hybrid crystalline polyester resin is preferably a graft copolymer having a crystalline polyester resin segment as a main chain and an amorphous resin segment as a side chain.
By setting it as the said form, the orientation of a crystalline polyester resin segment can be raised more and the crystallinity of hybrid resin can be improved.

  In addition, substituents, such as a sulfonic acid group, a carboxy group, and a urethane group, may be further introduced into the hybrid resin. The introduction of the substituent may be in the crystalline polyester resin segment or in the amorphous resin segment described below.

(Amorphous resin segment in hybrid resin)
The amorphous resin segment is a portion derived from an amorphous resin other than the crystalline polyester resin in the hybrid resin. The amorphous resin segment has a function of controlling the affinity between these resins when a hybrid resin and an amorphous resin are used in combination as a binder resin, and the amorphous resin segment is present. Therefore, when a hybrid resin and an amorphous resin are used in combination as a toner binder resin, the affinity between them is improved, and the hybrid resin is easily incorporated into the amorphous resin, improving the charging uniformity and the like. Can be made.

  The inclusion of an amorphous resin segment in the hybrid resin (and also in the toner) can be confirmed by specifying the chemical structure using, for example, NMR measurement or methylation reaction Py-GC / MS measurement. .

  The amorphous resin segment does not have a melting point and has a relatively high glass transition temperature (Tg) when differential scanning calorimetry (DSC) is performed on a resin having the same chemical structure and molecular weight as the segment. It is a resin segment. At this time, for the resin having the same chemical structure and molecular weight as the segment, the glass transition temperature (Tg1) in the first temperature rising process in DSC measurement is preferably in the range of 30 to 80 ° C., particularly 40 to 40 ° C. It is preferably within the range of 65 ° C.

  The amorphous resin segment is not particularly limited as long as it is defined above. For example, for a resin having a structure in which a main chain of an amorphous resin segment is copolymerized with other components, or a resin having a structure in which an amorphous resin segment is copolymerized with a main chain composed of other components, this resin ( If the toner containing the resin has an amorphous resin segment as described above, the resin corresponds to the hybrid resin having an amorphous resin segment in the present invention.

  The amorphous resin segment is preferably composed of the same type of resin as the amorphous resin contained in the binder resin used for toner production. By adopting such a form, the affinity between the hybrid resin and the amorphous resin is further improved, the hybrid resin is further easily taken into the amorphous resin, and the charging uniformity is further improved.

  Here, “the same kind of resin” means that a characteristic chemical bond is commonly contained in the repeating unit. Here, “characteristic chemical bond” is described in the National Institute for Materials Science (NIMS) Substance / Material Database (http://polymer.nims.go.jp/PoLyInfo/guide/jp/term_polymer.html). According to “Polymer classification”. That is, polyacryl, polyamide, polyanhydride, polycarbonate, polydiene, polyester, polyhaloolefin, polyimide, polyimine, polyketone, polyolefin, polyether, polyphenylene, polyphosphazene, polysiloxane, polystyrene, polysulfide, polysulfone, polyurethane, polyurea Chemical bonds constituting polymers classified according to a total of 22 types of polyvinyl and other polymers are referred to as “characteristic chemical bonds”.

  In addition, the “same kind of resin” in the case where the resin is a copolymer is characteristic when the monomer type having the above chemical bond is used as a constituent unit in the chemical structure of a plurality of monomer types constituting the copolymer. Refers to resins having common chemical bonds. Therefore, even if the characteristics of the resin itself are different from each other, or even when the molar component ratios of the monomer species constituting the copolymer are different from each other, the same type of chemical bonds are used as long as they have a common chemical bond. Considered resin.

  For example, a resin (or resin segment) formed of styrene, butyl acrylate and acrylic acid and a resin (or resin segment) formed of styrene, butyl acrylate and methacrylic acid have at least chemical bonds constituting polyacryl. These are the same kind of resins. To further illustrate, a resin (or resin segment) formed of styrene, butyl acrylate and acrylic acid and a resin (or resin segment) formed of styrene, butyl acrylate, acrylic acid, terephthalic acid and fumaric acid are mutually As a common chemical bond, it has a chemical bond constituting at least polyacryl. Therefore, these are the same kind of resins.

  The resin component constituting the amorphous resin segment is not particularly limited, and examples thereof include a vinyl resin segment, a urethane resin segment, and a urea resin segment. Among these, a vinyl resin segment is preferable because it is easy to control thermoplasticity.

  The vinyl resin segment is not particularly limited as long as a vinyl compound is polymerized, and examples thereof include an acrylic ester resin segment, a styrene / acrylic ester resin segment, and an ethylene-vinyl acetate resin segment. These may be used individually by 1 type and may be used in combination of 2 or more type.

  Among the vinyl resin segments, a styrene / acrylic acid ester resin segment (styrene / acrylic resin segment) is preferable from the viewpoint of forming a uniform and fine domain structure of the plasticizer. Therefore, the styrene / acrylic resin segment as the amorphous resin segment will be described below. A resin formed by bonding a crystalline polyester resin segment and a styrene / acrylic resin segment is referred to as a styrene / acrylic modified polyester resin.

The styrene / acrylic resin segment is formed by addition polymerization of at least a styrene monomer and a (meth) acrylic acid ester monomer. Styrene monomer as referred to herein, in addition to styrene represented by the structural formula _{CH 2 = CH-C 6 H} 5, is intended to include a structure having a known side-chain or functional groups styrene structure. In addition, the (meth) acrylic acid ester monomer referred to here is an acrylic acid ester derivative or methacrylic acid in addition to the acrylic acid ester compound or methacrylic acid ester compound represented by CH ₂ = CHCOOR (R is an alkyl group). It includes an ester compound having a known side chain or functional group in the structure of an ester derivative or the like.

  Specific examples of styrene monomers and (meth) acrylate monomers that can form styrene / acrylic resin segments are shown below, but they can be used to form styrene / acrylic resin segments used in the present invention. These are not limited to those shown below.

  First, specific examples of the styrene monomer include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4- Examples thereof include dimethyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, and pn-dodecyl styrene. These styrene monomers can be used alone or in combination of two or more.

  Specific examples of the (meth) acrylic acid ester monomer include, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate. Acrylate monomers such as stearyl acrylate, lauryl acrylate, and phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, Stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl meta Relate, methacrylic acid esters such as dimethyl aminoethyl methacrylate.

  In this specification, “(meth) acrylic acid ester monomer” is a general term for “acrylic acid ester monomer” and “methacrylic acid ester monomer”. “Methyl acrylate” is a general term for “methyl acrylate” and “methyl methacrylate”.

  These acrylic acid ester monomers or methacrylic acid ester monomers can be used alone or in combination of two or more. That is, a copolymer is formed using a styrene monomer and two or more acrylate monomers, and a copolymer is formed using a styrene monomer and two or more methacrylic ester monomers. Either a coalescence can be formed, or a copolymer can be formed by using a styrene monomer, an acrylate monomer, and a methacrylate ester monomer in combination.

  It is preferable that the content rate of the structural unit derived from the styrene monomer in an amorphous resin segment exists in the range of 40-90 mass% with respect to the whole quantity of an amorphous resin segment. Moreover, the content rate of the structural unit derived from the (meth) acrylic acid ester monomer in an amorphous resin segment may be in the range of 10-60 mass% with respect to the whole quantity of an amorphous resin segment. preferable. By making it within such a range, it becomes easy to control the plasticity of the hybrid resin.

  Further, the amorphous resin segment is preferably formed by addition polymerization of a compound for chemically bonding to the crystalline polyester resin segment in addition to the styrene monomer and the (meth) acrylate monomer. . Specifically, it is preferable to use a compound that is ester-bonded to a polyhydric alcohol-derived hydroxy group [—OH] or a polyvalent carboxylic acid-derived carboxy group [—COOH] contained in the crystalline polyester resin segment. Therefore, the amorphous resin segment can be addition-polymerized with respect to the styrene monomer and the (meth) acrylate monomer, and has a carboxy group [—COOH] or a hydroxy group [—OH]. It is preferable to further polymerize the compound.

  Examples of such compounds include compounds having a carboxy group such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester; 2-hydroxy Ethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate And compounds having a hydroxy group, such as polyethylene glycol mono (meth) acrylate.

It is preferable that the content rate of the structural unit derived from the said compound in an amorphous resin segment exists in the range of 0.5-20 mass% with respect to the whole quantity of an amorphous resin segment.
The method for forming the styrene / acrylic resin segment is not particularly limited, and examples thereof include a method of polymerizing a monomer using a known oil-soluble or water-soluble polymerization initiator. Specific examples of the oil-soluble polymerization initiator include the following azo or diazo polymerization initiators and peroxide polymerization initiators.

  Examples of the azo or diazo polymerization initiator include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1 -Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and the like.

  As the peroxide polymerization initiator, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4 -Dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4-t-butylperoxycyclohexyl) propane, tris- (t-butylperoxy) triazine and the like.

  Moreover, when forming resin particles by an emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and its salts, hydrogen peroxide, and the like.

  The content of the amorphous resin segment is preferably 20% by mass or less with respect to the total amount of the hybrid resin. Thereby, the effect that a more uniform crystalline polyester resin domain can be formed while maintaining sufficient crystallinity is obtained.

(Method for producing hybrid resin)
The method for producing the hybrid resin is not particularly limited as long as it can form a polymer having a structure in which the crystalline polyester resin segment and the amorphous resin segment are chemically bonded. Specific examples of the method for producing the hybrid resin include the following methods.

(1) A method of producing a hybrid resin by polymerizing an amorphous resin segment in advance and performing a polymerization reaction to form a crystalline polyester resin segment in the presence of the amorphous resin segment.

  In this method, first, a monomer (preferably a vinyl monomer such as a styrene monomer and a (meth) acrylic acid ester monomer) constituting the above-described amorphous resin segment is subjected to an addition reaction to form an amorphous material. A conductive resin segment is formed. Next, in the presence of the amorphous resin segment, a polyvalent carboxylic acid and a polyhydric alcohol are polymerized to form a crystalline polyester resin segment. At this time, a polyhydric carboxylic acid and a polyhydric alcohol are subjected to a condensation reaction, and a polycarboxylic acid or a polyhydric alcohol is added to the amorphous resin segment to form a hybrid resin.

In this method, it is preferable to incorporate a site where these segments can react with each other in the crystalline polyester resin segment or the amorphous resin segment.
Specifically, when the amorphous resin segment is formed, in addition to the monomer constituting the amorphous resin segment, a carboxy group [—COOH] or a hydroxy group [—OH] remaining in the crystalline polyester resin segment A compound having a site capable of reacting with the non-crystalline resin segment and a site capable of reacting with the amorphous resin segment is also used. That is, when this compound reacts with the carboxy group [—COOH] or the hydroxy group [—OH] in the crystalline polyester resin segment, the crystalline polyester resin segment may be chemically bonded to the amorphous resin segment. it can.

Moreover, you may use the compound which can react with a polyhydric alcohol or polyhydric carboxylic acid at the time of formation of a crystalline polyester resin segment, and has a site | part which can react with an amorphous resin segment.
By using this method, a hybrid resin having a structure (graft structure) in which a crystalline polyester resin segment is chemically bonded to an amorphous resin segment can be formed.

(2) A method of producing a hybrid resin by forming a crystalline polyester resin segment and an amorphous resin segment, respectively, and combining them.
In this method, a polyvalent carboxylic acid and a polyhydric alcohol are first subjected to a condensation reaction to form a crystalline polyester resin segment. In addition to the reaction system for forming the crystalline polyester resin segment, the above-described monomer constituting the amorphous resin segment is subjected to addition polymerization to form the amorphous resin segment. At this time, it is preferable to incorporate a site where the crystalline polyester resin segment and the amorphous resin segment can react with each other. In addition, since the method of incorporating such a reactive site is as described above, detailed description thereof is omitted.

  Next, the crystalline polyester resin segment formed above and the amorphous resin segment are reacted to form a hybrid resin having a structure in which the crystalline polyester resin segment and the amorphous resin segment are chemically bonded. Can do.

  In addition, when the reactive site is not incorporated in the crystalline polyester resin segment and the amorphous resin segment, a system in which the crystalline polyester resin segment and the amorphous resin segment coexist is formed, You may employ | adopt the method of throwing in the compound which has a site | part which can be combined with a crystalline polyester resin segment and an amorphous resin segment. Then, a hybrid resin having a structure in which the crystalline polyester resin segment and the amorphous resin segment are chemically bonded can be formed via the compound.

  (3) A method for producing a hybrid resin by forming a crystalline polyester resin segment in advance and performing a polymerization reaction to form an amorphous resin segment in the presence of the crystalline polyester resin segment.

  In this method, first, a polyvalent carboxylic acid and a polyhydric alcohol are subjected to a condensation reaction for polymerization to form a crystalline polyester resin segment. Next, in the presence of the crystalline polyester resin segment, a monomer constituting the amorphous resin segment is polymerized to form an amorphous resin segment. At this time, it is preferable to incorporate a site where these segments can react with each other in the crystalline polyester resin segment or the amorphous resin segment, as in the above (1). In addition, since the method of incorporating such a reactive site is as described above, detailed description thereof is omitted.

By using the above method, a hybrid resin having a structure (graft structure) in which an amorphous resin segment is chemically bonded to a crystalline polyester resin segment can be formed.
Among the methods (1) to (3), the method (1) facilitates the formation of a hybrid resin having a structure in which a crystalline polyester resin chain is grafted to an amorphous resin chain, and simplifies the production process. This is preferable because it is possible. In the method (1), since the amorphous resin segment is formed in advance and then the crystalline polyester resin segment is bonded, the orientation of the crystalline polyester resin segment tends to be uniform. Therefore, it is preferable because a hybrid resin suitable for the toner specified in the present invention can be reliably formed.

<solvent>
The solvent (organic solvent) used for the preparation of the CPES solution (oil phase) has a low boiling point and low water solubility from the viewpoint of easy removal after phase inversion emulsification. Specific examples 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.

  In addition, when the crystalline polyester resin is dissolved, it is preferable to use water as a solvent in addition to the above solvent (organic solvent). In the neutralization step described later, the neutralizing agent is easily diffused, and the acidic groups of the polyester resin that is not neutralized is reduced. As a result, a fine particle dispersion having a substantially uniform particle diameter is obtained. As usage-amount of the water with respect to an organic solvent, it is preferable that it is 11-98 mass parts with respect to 100 mass parts of organic solvents, and it is more preferable that it is 54-82 mass parts.

(Dissolved resin concentration)
The resin dissolution concentration (hereinafter also referred to as “dissolution resin concentration”) is preferably 50 to 300 parts by mass of a crystalline polyester resin in 100 parts by mass of a solvent (organic solvent).
When the amount of the crystalline polyester resin used is 300 parts by mass or less, since the oil / water interface is not destabilized without the resin concentration being too high, a dispersion having a sharp particle size distribution can be obtained. Moreover, it is preferable to use 50 mass parts or more of crystalline polyester resin from a viewpoint of productivity improvement. Moreover, since the oil-water interface is stabilized and a dispersion having a small particle size and a sharp particle size distribution is obtained, 100 to 150 parts by mass of the crystalline polyester resin is dissolved in 100 parts by mass of the solvent (organic solvent). Is more preferable.

<Preparation of CPES solution>
The crystalline polyester resin and an organic solvent (oil phase) are mixed. Thereby, a solution (CPES solution (oil phase)) is prepared. As the conditions for this dissolution step, it is desirable to uniformly disperse the crystalline polyester resin at the molecular level in an organic solvent. Therefore, the temperature is 20 ° C. lower than the melting point of the crystalline polyester resin, more preferably, It is preferable to dissolve the crystalline polyester resin at a temperature (liquid temperature) that is 10 ° C. lower than the melting point. The upper limit of the temperature range in the dissolution step is not higher than the boiling point of the organic solvent (the azeotropic point when plural types of solvents are mixed, such as when the solvent contains water) and lower than the temperature at which the resin decomposes. Good.

  Moreover, what is necessary is just to mix (stir) for 40 to 60 minutes as mixing (stirring) time. The mixing and stirring device is not particularly limited and may be appropriately selected according to the production scale. That is, as a method for obtaining a CPES solution (oil phase), an organic solvent (oil phase) is placed in a container and heated to the above temperature (liquid temperature). A method in which a crystalline polyester resin is added and mixed here, and the polyester resin is dissolved in an organic solvent (oil phase) and uniformly mixed while stirring with a stirrer. However, after the crystalline polyester resin and the organic solvent (oil phase) are put in a container in advance, the crystalline polyester resin is dissolved in the organic solvent (oil phase) while heating and stirring to the above temperature (liquid temperature). There is no particular limitation such as uniform mixing.

<< Neutralization process (process 2) >>
The neutralization step (step 2) is a step of adding a neutralizing agent to the solution obtained in the dissolution step. In this step, a neutralizing agent is added to the CPES solution (oil phase) obtained in Step 1 and mixed. Thereby, a neutralized liquid (cophase) is prepared. When adding the neutralizing agent, it is desirable that the crystalline polyester resin is uniformly dispersed at the molecular level in the solvent so that the neutralizing agent acts uniformly on the entire crystalline polyester resin. It is preferable to add the neutralizing agent while holding the CPES solution at a temperature (liquid temperature) of 20 ° C. lower than the melting point of the polyester resin, more preferably 10 ° C. lower than the melting point. . The upper limit of the temperature range in the neutralization step is not more than the boiling point of the organic solvent (the azeotropic point when a plurality of solvents are mixed, such as when the solvent contains water) and not more than the temperature at which the resin decomposes. Good. Further, a surfactant (aqueous solution) may be added to and mixed with a solution (oil phase) in which the crystalline polyester resin is dissolved in an organic solvent. By adding the surfactant, the surface tension at the interface between the oil phase and the water phase can be further lowered and the interface can be stabilized.

<Surfactant (aqueous solution)>
In Step 2, before adding the neutralizing agent as described above, the surfactant (aqueous solution) is added to and mixed with the solution (oil phase) in which the crystalline polyester resin is dissolved in the organic solvent, and water droplets are added to the oil phase. A solution (emulsion) in a state (W / O) in which is dispersed may be formed.
The surfactant is not particularly limited, and known surfactants can be used, and are selected from cationic surfactants, anionic surfactants, nonionic surfactants, and the like. Can be used. Two or more of these surfactants may be used in combination. The surfactant can also be used in a dispersion liquid such as a colorant or an offset preventing agent used in the production of the toner. The surfactant is used as an aqueous solution from the viewpoint of forming a solution (emulsion) in a state where water droplets are dispersed in the oil phase (W / O).

  Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, and hexadecyl trimethyl ammonium bromide.

  Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose.

  Specific examples of anionic surfactants include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and polyoxyethylene (2) sodium lauryl ether sulfate. Can do.

These surfactants can be used alone or in combination of two or more as required.
From the viewpoint of forming a solution in which water droplets are dispersed in the oil phase (W / O) with respect to 100 parts by mass of the polyester resin in the PES solution (oil phase) 13, Preferably it is 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass. It is below mass parts.

  The temperature (liquid temperature) when adding the surfactant aqueous solution is the temperature of the solution (CPES solution) obtained in Step 1 on the side where the surfactant is added, the particle size is small, the particle size From the viewpoint of obtaining a dispersion (aqueous phase) of CPES particles having a narrow distribution, the temperature is 20 ° C. lower than the melting point of the crystalline polyester resin, more preferably 10 ° C. lower than the melting point, and the surfactant. The boiling point of the aqueous solution is preferred.

<Neutralizing agent>
In the present invention, the neutralizing agent for neutralizing the crystalline polyester resin can obtain a crystalline polyester resin aqueous dispersion having a small particle size and a narrow particle size distribution, and from the viewpoint of ease of handling, It is preferably used as an aqueous solution. When a W / O solution is formed using the surfactant (aqueous solution), the neutral phase is added to the solution to dissociate the polyester terminal group (COOH group), thereby allowing the oil phase and water to dissociate. It is possible to reduce the interfacial tension with the phase and form a neutralized liquid in which the oil phase and the aqueous phase are mixed (cophase). In addition, when no surfactant is added to the solution (oil phase), a solution in which water droplets are dispersed in the oil phase (W / O) can be obtained by adding an aqueous neutralizing agent solution. Forming and further dissociating the polyester end groups (COOH groups) to lower the interfacial tension between the oil phase and the aqueous phase, thereby forming a neutralized solution in which the oil phase and the aqueous phase are mixed (co-phase) You can also.

  The neutralizing agent may be an alkaline compound, and any of an inorganic alkaline compound and an organic alkaline compound may be used. Examples of the inorganic alkaline compound include alkali metal hydroxide salts such as potassium, sodium, and lithium, carbonates, bicarbonates, and ammonia. Specific examples of the alkali metal hydroxide salt, carbonate, and bicarbonate include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate. Examples of the organic alkaline compound include alkanolamines such as diethylethanolamine. Further, from the viewpoint of controlling the pH of the alkaline aqueous solution without reducing the neutralization reaction efficiency, a buffer solution obtained by mixing a strongly alkaline compound and a weakly acidic compound may be used. For example, potassium hydroxide And a buffer solution obtained by mixing phosphoric acid. Of these, sodium hydroxide is more preferred because of its availability and strong alkali.

  When the neutralizing agent is used as an aqueous solution, the concentration of the neutralizing agent (alkaline compound) in the aqueous solution is preferably 1% by mass or more, more preferably 5% by mass or more from the viewpoint of forming a stable cophase state earlier. More preferably, it is 8% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less.

  The temperature (liquid temperature) at which the neutralizing agent aqueous solution is added maintains the temperature of the solution (CPES solution) obtained in Step 1 on the side where the neutralizing agent is added, the particle size is small, the particle size From the viewpoint of obtaining a dispersion (aqueous phase) of CPES particles having a narrow distribution, the temperature is 20 ° C. lower than the melting point of the crystalline polyester resin, more preferably 10 ° C. lower than the melting point. The boiling point of the aqueous solution is preferred.

<< Phase inversion emulsification process (process 3) >>
The phase inversion emulsification step (step 3) is a step in which an aqueous medium is dropped into the neutralized liquid obtained in the neutralization step to perform phase inversion emulsification. In this step, an aqueous medium (pure water) is continuously added to the solution (neutralization solution (cophase)) obtained in step 2 to form resin particles (CPES particles). Thereby, phase inversion emulsification is completed, and a crystalline polyester resin aqueous dispersion (CPES particle dispersion (aqueous phase)) can be obtained. Here, when pure water is continuously added dropwise to the solution obtained in step 2 (neutralization solution (cophase)), the polyester end groups are dissociated and imparted with self-emulsifying properties, so resin particles (CPES) are added to the aqueous phase. A dispersion liquid (emulsion) in a state (O / W) in which particles are dispersed is formed.

  In the present invention, the aqueous medium is dropped into a neutralizing solution containing water in the range of 12 to 50% by mass with respect to the total amount of the solvent, and phase inversion emulsification is performed, so that the particle size distribution is small and the particle size distribution is small. A dispersion of sharp crystalline polyester resin particles (CPES particles) is obtained. That is, the present invention is characterized in that the ratio of water in the solvent contained in the neutralization solution immediately before the dropping of the aqueous medium (hereinafter also referred to as “water content before phase inversion emulsification”) is set to a predetermined amount. . The water content before phase inversion emulsification is in the range of 12 to 50% by mass, more preferably in the range of 15 to 30% by mass, and the phase of the emulsification in the system makes the state of the entire oil-water interface uniform. An emulsion dispersion having a sharp particle size distribution and a small particle size can be obtained.

  In general, in the phase inversion emulsification method, an activator or neutralizing agent is added to a resin solution to ionize acidic groups in the molecule, and then an aqueous medium is added to perform phase inversion. Water in which the agent is diluted is also contained in the system. Before the phase inversion, if the ratio of water contained in the system is too much with respect to the total amount of the solvent in the neutralized liquid, the oil-water interface is destabilized and before the aqueous medium is dropped in the phase inversion emulsification step. In addition, part of the oil phase is phase-inverted to form oil droplets (emulsified dispersion particles), and the phase inversion process is non-uniform, resulting in an emulsion dispersion having a wide particle size distribution. For this reason, if the water content before phase inversion emulsification exceeds 50% by mass, that is, it is excessive, phase inversion emulsification starts in a part of the cophase state before dropping of the aqueous medium. The particle size distribution becomes wider. Further, if the water content before phase inversion emulsification is excessive, phase inversion emulsification may not be performed. The reason for this is that as the water content before phase inversion emulsification increases, the state of the oil / water interface before phase inversion becomes unstable (that is, the cophase state becomes unstable), and the cophase state cannot be formed well. I guess. Further, if the water content before phase inversion emulsification is less than 12% by mass, that is, too little, in the neutralization step, the mixing property of the neutralizing agent is lowered, and the carboxy group in the crystalline polyester resin is sufficiently neutralized. However, the particle size distribution becomes wider. On the other hand, in the present invention, by carrying out phase inversion emulsification with a predetermined amount of water before phase inversion emulsification, the state of the oil-water interface throughout the system is made uniform, and an emulsion dispersion having a sharp particle size distribution and a small particle size is obtained. It is done.

<Pure water>
In this step (phase inversion emulsification step), pure water is used from the viewpoint of easy preparation of a dispersion (water phase) of CPES particles having a small particle size and a narrow particle size distribution. The pure water is not particularly limited, and conventionally known water can be used. For example, RO water (water through a reverse osmosis membrane) obtained by a method of removing impurities from water (clean water, etc.), deionized water (water from which ions have been removed by an ion exchange resin, etc.), distilled water (with a distiller) Distilled water) can be used.

  The temperature at which pure water is added (liquid temperature) maintains the temperature of the solution (neutralizing liquid) obtained in step 2 on the side where pure water is added, the particle size is small, and the particle size distribution is narrow. From the viewpoint of obtaining a dispersion (aqueous phase) of CPES particles, the temperature is at least 20 ° C. lower than the melting point of the crystalline polyester resin, more preferably at least 10 ° C. lower than the melting point. Or less than the boiling point.

  From the viewpoint of obtaining a dispersion (aqueous phase) of CPES particles having a small particle size and a narrow particle size distribution, the addition rate when continuously adding pure water is from the viewpoint of obtaining (dispersing) phase inversion emulsification. Preferably it is 0.1 mass part / min or more with respect to 100 mass parts of resin which comprises the resin particle in the solution obtained at the process 2, More preferably, it is 1 mass part / min or more, More preferably, it is 3 mass parts / min. Min. Or more, preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 15 parts by mass or less, and particularly preferably 8 parts by mass or less. That is, pure water can be continuously added by the operation of adding pure water at the above addition rate. In addition, there is no restriction | limiting in the addition speed | rate of the pure water after completion | finish of phase inversion emulsification (It is preferable to finish addition of the pure water after completion | finish of phase inversion emulsification as quickly as possible). Completion of phase inversion emulsification can be confirmed by the milky white dispersion.

  From the viewpoint of improving the production efficiency of the PES particle dispersion (aqueous phase), the amount of pure water used is preferably 50 masses relative to 100 mass parts of the resin particles constituting the resin particles in the solution obtained in step 2. Part or more, more preferably 100 parts by weight or more, still more preferably 150 parts by weight or more, and preferably 2000 parts by weight or less, more preferably 1000 parts by weight or less, still more preferably 500 parts by weight or less.

(Preparation of CPES particle dispersion (aqueous phase))
Pure water is continuously added to the neutralized solution (cophase) within the range of the temperature (liquid temperature) and the amount used, specifically at the addition rate, and mixed. This produces an emulsified CPES particle dispersion (aqueous phase) (emulsion). The condition during continuous addition of pure water (phase inversion emulsification step) was obtained in step 2 on the side where pure water was added from the viewpoint of obtaining an emulsified dispersion having a sharp particle size distribution and a small particle size. While maintaining the solution (neutralization solution) at a temperature 20 ° C. or more lower than the melting point of the crystalline polyester resin, more preferably at a temperature (liquid temperature) 10 ° C. lower than the melting point, while stirring, It is preferable to add a fixed amount of pure water 18 continuously. The upper limit of the temperature range in the phase inversion emulsification step is not more than the boiling point of the organic solvent (the azeotropic point when a plurality of solvents are mixed, such as when the solvent contains water) and not more than the temperature at which the resin decomposes. I just need it.

  As described above, the present invention is characterized in that the phase inversion emulsification step is performed at a temperature of 20 ° C. or more lower than the melting point of the crystalline polyester resin. Unlike amorphous polyesters, crystalline polyesters with a melting point change molecular mobility greatly before and after the melting point, so it is sufficient not to inhibit phase inversion by emulsifying at a temperature of 20 ° C. or lower than the melting point. It is necessary to ensure proper molecular mobility. By heating in an organic solvent, sufficient molecular mobility can be secured if the temperature is 20 ° C lower than the melting point even if the melting point is not reached, the state of the entire oil-water interface in the system is uniformed, and the particle size An emulsified dispersion having a sharp distribution and a small particle size is obtained. The reaction vessel used for phase inversion emulsification is not particularly limited, but the reaction vessel used in the previous step is preferably used as it is. The emulsification and dispersion can be performed using mechanical energy, and the disperser (mixing and stirring device) for performing emulsification and dispersion is not particularly limited. Examples include a shearing disperser, a friction disperser, a high-pressure jet disperser, and an ultrasonic disperser. Specifically, for example, a TK homomixer (manufactured by Primix Co., Ltd.) can be used.

The dispersion diameter of the oil droplets in the emulsion (CPES particle dispersion (aqueous phase)) is preferably in the range of 60 to 1000 nm, more preferably in the range of 80 to 500 nm.
The dispersion diameter of the oil droplets is determined by a particle size distribution measuring device (for example, Nanotrack Wave (manufactured by Microtrack Bell)) or a laser diffraction / scattering type particle size distribution measuring device (for example, LA-750, LA-960 (both are corporations). Volume average particle diameter measured using HORIBA, Ltd.).

[Method for measuring water content before phase inversion emulsification]
In the present invention, the amount of water before phase inversion emulsification is the ratio of water in the solvent contained in the neutralized solution immediately before the dropping of the aqueous medium, and examples of the measurement method include the following.
First, five samples are prepared by mixing a solvent, a crystalline polyester resin, and water in an arbitrary ratio. Using gas chromatography, the peak area of water in each sample is calculated, and a calibration curve (the horizontal axis: the ratio of water in the sample solvent, the ratio of water in the actual sample solvent) (Vertical axis: peak area of water obtained by gas chromatography). Next, gas chromatography measurement is performed using the target sample, and the ratio of water in the sample solvent is calculated from the peak area of the obtained water using a calibration curve.

Apparatus: Headspace autosampler “G1888” and gas chromatograph “Agilent 7890A GC system” (all manufactured by Agilent Technologies)
The measurement conditions are as follows.

<Head space autosampler setting conditions>
Oven temperature: 110 ° C
Needle temperature: 150 ° C
Transfer temperature: 150 ° C

<Gas chromatograph measurement conditions>
Column: DB-624 (inner diameter 250 μm, film thickness 1.4 μm, length 30 mm) (manufactured by Agilent Technologies)
Carrier: Helium gas Injection temperature: 200 ° C
Detector temperature: 250 ° C
Column flow rate: 1.5 mL / min Column temperature: Hold at 40 ° C. for 2 minutes, then measure up to 230 ° C. at a heating rate of 10 ° C./min. In addition to the actual measurement using the gas chromatography, phase inversion emulsification Calculation can also be performed from the amount of each reagent used before the process and the water content of each reagent.

<< Demelting process (process 4) >>
The desolubilization step (step 4) is a step of desolvating the organic solvent from the resin particle dispersion obtained in step 3. By desolubilization, a dispersion liquid (CPES particle dispersion liquid (aqueous phase)) in which the crystalline polyester resin particles of the present invention are dispersed in an aqueous medium is obtained.

  As a specific method for removing the organic solvent, for example, a vacuum distillation method for promoting the evaporation of the organic solvent by heating the emulsion and placing it in a pressure state lower than the atmospheric pressure can be mentioned as a preferable method. The heating temperature, reduced pressure conditions, and the like are appropriately determined according to the type and boiling point of the organic solvent. Preferably, the heating temperature of the emulsified liquid is 30 to 100 ° C., the pressure during decompression is 3 to 60 kPa (30 to 600 mbar), and the temperature is maintained for 40 to 180 minutes while stirring.

(Volume average particle diameter of resin particles (CPES particles) in CPES particle dispersion (water phase))
The volume average particle diameter of the resin particles (CPES particles) in the crystalline polyester resin aqueous dispersion (CPES particle dispersion (aqueous phase)) obtained in step 4 is 50 to 500 nm, more preferably 200 to 400 nm. is there. When the volume average particle size is larger than 50 nm, the cohesive force between particles does not become too strong, and dispersion is maintained in a state where the CPES particles are primary particles, which is preferable (if the volume average particle size is too small, 1 The secondary particles may aggregate to form secondary particles having a large particle size). A volume average particle size of less than 500 nm is preferable because the dispersibility of the crystalline polyester resin in the toner becomes good and the fixability is improved. Here, the volume average particle size is determined by a particle size distribution measuring device such as a particle size distribution measuring device (for example, Nanotrac Wave EX150 (manufactured by Microtrac Bell)) or a laser diffraction particle size distribution measuring device (for example, laser diffraction). / A scattering type particle size distribution measuring device LA-750, LA-960 (manufactured by Horiba, Ltd.) can be used.

(CV value of resin particles (CPES particles) in CPES particle dispersion (aqueous phase))
The coefficient of variation (CV value) of the resin particles (CPES particles) in the aqueous crystalline polyester resin dispersion (CPES particle dispersion (aqueous phase)) obtained in Step 4 is 10 to 60%, more preferably 25. ~ 35%. The CV value is an index of particle size distribution, and the smaller the CV value, the sharper the particle size distribution. A CV value of less than 60% is preferable because the particle size distribution is sharp and many resin particles having a small particle diameter are present, the dispersibility of the crystalline polyester resin in the toner becomes good, and the fixability is improved.

  On the other hand, when the CV value is 10% or more, there are some crystalline polyester resin fine particles having a particle size smaller than the volume average particle size, and the fine particles having a small particle size exhibit an effect as a plasticizer at the time of fixing the toner. Therefore, it is preferable.

The formula for calculating the CV value is represented by the following formula 1.
Formula 1: coefficient of variation (CV value) (%) = (standard deviation of particle size distribution / volume average particle size) × 100
The crystalline polyester resin aqueous dispersion of the present invention can be produced by the steps described above. Next, a toner manufacturing method using this will be described.

<Method for producing toner>
The toner production method of the present invention is characterized by using the CPES particle dispersion obtained above and aggregating and fusing at least resin particles contained in the CPES particle dispersion in an aqueous medium. Is. By producing a toner using the crystalline polyester resin aqueous dispersion having a small particle size and a sharp particle size distribution according to the present invention, the dispersibility of the crystalline polyester resin inside the toner is improved and fixing is performed. Can be improved.

  Here, the CPES particle dispersion obtained above is an aqueous dispersion in which CPES particles which are one kind of binder resin (hereinafter also referred to as “binder resin fine particles (1)”) are dispersed. . Also, for example, binder resins other than CPES particles, for example, acrylic resins such as styrene resins and alkyl acrylates and alkyl methacrylates, resins such as styrene / acrylic resins, silicone resins, olefin resins, amide resins, and epoxy resins An aqueous dispersion in which particles (hereinafter also referred to as “binder resin fine particles (2)”) are dispersed; an aqueous dispersion in which fine particles of colorant (hereinafter also referred to as “colorant fine particles”) are dispersed. An aqueous dispersion in which fine particles of a release agent (hereinafter also referred to as “release agent fine particles”) are dispersed may be used.

  That is, in the toner production method of the present invention, the binder resin fine particles (2) may be added to the CPES particle dispersion obtained above (aqueous dispersion in which the binder resin fine particles (1) are dispersed) as necessary. Are mixed with an aqueous dispersion in which colorant fine particles are dispersed, an aqueous dispersion in which release agent fine particles are dispersed, and the like. In this method, toner particles are formed by agglomerating and fusing the resin particles (2), the colorant particles, the release agent particles, etc.).

An example of a toner production method (an example in which an amorphous resin (binding resin fine particle (2) forming resin) and a crystalline polyester resin (binding resin fine particle (1) forming resin) are used as a binding resin). Specifically,
(A) forming a precursor (I) (core particle) of the binder resin fine particles (2);
(B) forming a precursor (II) of the binder resin fine particles (2) (intermediate layer covering the surface of the core particles; intermediate layer-coated particles);
(C) Binder resin fine particles (2) (core particles / intermediate layer / by formation of precursor (III) of binder resin fine particles (2) (outermost layer covering intermediate layer coated particle surface; outermost layer coated particles) A step of forming the outermost three-layer particles),
(D) a step of preparing an aqueous dispersion in which fine particles (binder resin fine particles (1)) of a crystalline polyester resin are dispersed as the CPES particle dispersion obtained above,
(E) a step of preparing an aqueous dispersion in which colorant fine particles are dispersed in an aqueous medium;
(F) a step of forming toner particles;
(G) a step of cooling the dispersion of toner particles;
(H) separating the toner particles from the aqueous medium and removing the surfactant from the toner particles;
(I) drying the washed toner particles;
If necessary, (j) a step of adding an external additive to the dried toner particles can be added.

Here, the “aqueous dispersion” is a dispersion in which a dispersion (fine particles) is dispersed in an aqueous medium, and the aqueous medium is one in which a main component (50% by mass or more) is water. .
Examples of components other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are particularly preferable.

(A) Binder resin fine particle (2) precursor (I) (core particle) forming step (first polymerization)
In this step, the precursor (I) (core particle) of the binder resin fine particles (2) is formed by emulsion polymerization according to a conventional method.
Specifically, the polymerization initiator is added to the surfactant solution and heated, and the monomer solution for forming the core particles of the binder resin fine particles (2) is dropped and reacted while stirring.
The reaction temperature is preferably in the range of 70 to 90 ° C, for example.

  The average particle diameter of the precursor (I) (core particle) of the binder resin fine particles (2) is preferably in the range of 50 to 150 nm in terms of volume-based median diameter. The volume-based median diameter of the precursor (I) (core particle) of the binder resin fine particles (2) is a value measured using “UPA-150” (manufactured by Microtrack).

(B) Step of forming precursor (II) of binder resin fine particles (2) (intermediate layer covering core particle surface; intermediate layer coated particles) (second polymerization)
In this step, the binder resin fine particles (2) containing a polymerization initiator and a release agent in a dispersion of the precursor (I) (core particles) of the binder resin fine particles (2) formed by the first polymerization. The intermediate layer-coated particles are formed by adding the polymerizable monomer for forming the intermediate layer to form the precursor (II) (intermediate layer) of the binder resin fine particles (2).
Specifically, a binder resin fine particle (2) in which a surfactant solution is added to a dispersion of the precursor (I) (core particle) of the binder resin fine particles (2) and a release agent are dissolved. The intermediate layer forming polymerizable monomer is heated, mixed and dispersed by a mechanical disperser, added with a polymerization initiator, and polymerized by stirring while heating.

Moreover, the amount of the dispersion liquid in which the precursor (I) (core particle) of the binder resin fine particles (2) is dispersed is in the range of 5 to 50 parts by mass in the total solvent for performing the second polymerization. It is preferable in that both elasticity and low temperature fixability can be maintained.
The reaction temperature is preferably in the range of, for example, 70 to 95 ° C.

(C) Binder resin fine particles (2) (core particle / intermediate layer / outermost layer 3 layers) by forming precursor (III) of binder resin fine particles (2) (outermost layer covering the surface of the intermediate layer coated particles) Structure particle) formation step (third polymerization)
In this step, a binder resin fine particle (2) precursor (II) (intermediate layer coated particle) dispersion formed by the second polymerization is further added to the binder resin fine particle (2) for forming the outermost layer. The binder resin fine particles (2) (core particle / intermediate layer / outermost layer, three layers) are formed by adding a functional monomer to form the precursor (III) (outermost layer) of the binder resin fine particles (2). Structure particles).
Specifically, a polymerization initiator is added to the dispersion of the heated binder resin fine particle (2) precursor (II), and the polymerizable monomer for forming the binder resin fine particles (2) is added while stirring. Drop and polymerize.
The reaction temperature is preferably in the range of, for example, 70 to 95 ° C.

<Binder Resin Used for Binder Resin Fine Particles (2)>
The binder resin is preferably a thermoplastic resin, and can be used without particular limitation as long as it is other than a crystalline polyester resin among those generally used as a binder resin constituting a toner. In addition, even if it is a polyester resin, if it is an amorphous polyester resin, it can be used as a binder resin. Specific examples include styrene resins, acrylic resins such as alkyl acrylates and alkyl methacrylates, styrene / acrylic resins, silicone resins, olefin resins, amide resins, and epoxy resins. These resins can be used alone or in combination of two or more.
The content of the binder resin (amorphous resin) in the binder resin fine particles (2) is in the range of 50 to 95% by mass with respect to the total amount of toner particles from the viewpoint of charging stability of the toner. Is preferable, and it is more preferable that it is 70-95 mass%.

  The binder resin particularly preferably contains a styrene / acrylic resin obtained by polymerizing a styrene monomer and an acrylic monomer. Since the styrene / acrylic resin is a resin having a characteristic of high elasticity at a high temperature, the effect of improving the fixing separation property and the high temperature offset property can be obtained.

The binder resin preferably contains 30% by mass or more of styrene / acrylic resin from the viewpoint of manifesting the above effects.
The weight average molecular weight (Mw) of the styrene / acrylic resin is in the range of 25000 to 60000 and the number average molecular weight (Mn) is in the range of 8000 to 15000. It is preferable from the viewpoint of securing.

  Examples of polymerizable monomers used in styrene / acrylic resins include aromatic vinyl monomers and (meth) acrylic acid ester monomers, and ethylenically unsaturated bonds capable of radical polymerization. Those having the following are preferred.

  Styrene monomers include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2,4-dimethylstyrene 3,4-dichlorostyrene and the like and derivatives thereof. These aromatic vinyl monomers can be used alone or in combination of two or more.

  Examples of acrylic monomers include acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and phenyl acrylate. As ester monomers, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, methacrylic acid Examples thereof include dimethylaminoethyl and diethylaminoethyl methacrylate. These (meth) acrylic acid ester monomers can be used alone or in combination of two or more. Among the above, it is preferable to use a styrene monomer in combination with at least one of an acrylate monomer or a methacrylic acid monomer.

  As the polymerizable monomer, a third vinyl monomer can also be used. Examples of the third vinyl monomer include acid monomers such as acrylic acid, methacrylic acid, maleic anhydride, and vinyl acetic acid, and acrylamide, methacrylamide, acrylonitrile, ethylene, propylene, butylene, vinyl chloride, and N-vinylpyrrolidone. And butadiene.

  As the polymerizable monomer, a polyfunctional vinyl monomer may be further used. Examples of the polyfunctional vinyl monomer include diacrylates such as ethylene glycol, propylene glycol, butylene glycol, and hexylene glycol, and dimethacrylates and trimethacrylates of tertiary or higher alcohols such as divinylbenzene, pentaerythritol, and trimethylolpropane. Etc. The copolymerization ratio of the polyfunctional vinyl monomer to the entire polymerizable monomer is usually within the range of 0.001 to 5% by mass, preferably within the range of 0.003 to 2% by mass, more preferably 0. Within the range of 0.01 to 1% by mass. Although the gel component insoluble in tetrahydrofuran is generated by using the polyfunctional vinyl monomer, the proportion of the gel component in the whole polymer is usually 40% by mass or less, preferably 20% by mass or less.

  The binder resin is preferably prepared by an emulsion polymerization method according to the forming steps (a) to (c) described as an example of the toner production method. Emulsion polymerization can be obtained by dispersing and polymerizing a polymerizable monomer such as styrene or acrylate in an aqueous medium. In order to disperse the polymerizable monomer in the aqueous medium, it is preferable to use a surfactant. For polymerization (for example, the first polymerization or the third polymerization in the forming steps (a) to (c) above), polymerization is performed. An initiator, a chain transfer agent, etc. can be used.

(Polymerization initiator)
The polymerization initiator used for the polymerization of the binder resin (the first polymerization to the third polymerization in the forming steps (a) to (c) above) is not particularly limited, and a known one is used. can do. Specifically, for example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, peroxide Lauroyl, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid tert-hydroperoxide, tert-butyl formate, Peroxides such as tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) palmitate; 2,2 '-Azobis ( -Aminodipropane) hydrochloride, 2,2'-azobis- (2-aminodipropane) nitrate, 1,1'-azobis (sodium 1-methylbutyronitrile-3-sulfonate), 4,4'- And azo compounds such as azobis-4-cyanovaleric acid and poly (tetraethylene glycol-2,2′-azobisisobutyrate). The addition amount of the polymerization initiator varies depending on the desired molecular weight and molecular weight distribution, but specifically, it is preferably added in the range of 0.1 to 5% by mass with respect to the polymerizable monomer.

(Chain transfer agent)
In the production of the binder resin (the first polymerization to the third polymerization in the forming steps (a) to (c) above), it is also preferable to add a chain transfer agent together with the polymerizable monomer. The molecular weight of the polymer can be controlled by adding a chain transfer agent. In the polymerization step of polymerizing the aromatic vinyl monomer and the (meth) acrylic acid ester monomer, the molecular weight of the styrene / acrylic polymerizable monomer is generally adjusted for the purpose of adjusting the molecular weight. The chain transfer agent used can be used. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans and mercapto fatty acid esters.
The addition amount of the chain transfer agent varies depending on the desired molecular weight and molecular weight distribution, but specifically, it is preferably added in the range of 0.1 to 5% by mass with respect to the polymerizable monomer.

(Surfactant)
When the binder resin is dispersed in an aqueous medium and polymerized by an emulsion polymerization method (the first polymerization to the third polymerization in the forming steps (a) to (c) above), in order to prevent aggregation of the dispersed droplets, Usually a dispersion stabilizer is added. As the dispersion stabilizer, a known surfactant can be used, and a dispersion stabilizer selected from a cationic surfactant, an anionic surfactant, a nonionic surfactant and the like can be used. Two or more of these surfactants may be used in combination. The dispersion stabilizer can also be used in a dispersion liquid such as a colorant and an offset preventing agent.

  Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, and hexadecyl trimethyl ammonium bromide.

  Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose.

  Specific examples of anionic surfactants include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and polyoxyethylene (2) sodium lauryl ether sulfate. Can do. These surfactants can be used alone or in combination of two or more as required.

<Release agent>
The release agent may be contained in the toner particles. That is, in the production of the binder resin (the first polymerization to the third polymerization in the forming steps (a) to (c) above), it is also preferable to add a release agent together with the polymerizable monomer. However, it may be used as an aqueous dispersion in which release agent fine particles are dispersed. By containing the release agent in the toner particles, it becomes difficult to be compatible with the crystalline polyester resin (one kind of binder resin) contained in the toner particles, and it is easy to ooze out during heat fixing. High fixing separation can be obtained.

The content of the release agent is preferably 5 to 20% by mass with respect to the total amount of toner particles excluding the colorant. Thereby, it is possible to obtain an effect that fixing separation property can be improved while suppressing a decrease in heat resistance and durability due to the addition of a release agent.
The average particle diameter of the release agent contained in the binder resin (or toner particles) is not particularly limited, but for example, it is preferably 3 μm or less in volume-based median diameter.

As the releasing agent, various known waxes can be used. From the viewpoint of improving the low-temperature fixability and releasing property of the toner, a hydrocarbon wax or an ester wax is preferable.
Specifically, for example, low molecular weight polyethylene wax, low molecular weight polypropylene wax, Fischer-Tropsch wax, microcrystalline wax, hydrocarbon wax such as paraffin wax, carnauba wax, pentaerythritol behenate, behenyl behenate, And ester waxes such as behenyl citrate. These can be used alone or in combination of two or more.

  Of these waxes, from the viewpoint of releasability during low-temperature fixing, it is preferable to use a wax having a low melting point, specifically, a melting point in the range of 40 to 90 ° C.

  Further, it is preferable to form an independent domain different from the domain of the crystalline polyester resin (binder resin) as the state of presence of the release agent in the toner particles. The release agent and the crystalline polyester resin (binder resin) form different independent domains, so that each function is easily exhibited.

  In the production method of the present invention, when toner particles are produced in a state where a wax (release agent) is coated with the binder resin, domains different from the crystalline polyester resin (binder resin) are likely to be formed. Since the crystalline polyester resin (binder resin) and the release agent are not compatible with each other and exist in the matrix as different independent domains, the functions of the crystalline polyester resin (binder resin) and the release agent can be achieved. Since the respective functions can be fully exhibited without being impaired, a toner having good low-temperature fixability, fixing separation property and offset property on rough paper can be obtained.

(D) Step of preparing an aqueous dispersion of crystalline polyester resin fine particles In this step, an aqueous dispersion of crystalline polyester resin fine particles using a crystalline polyester resin is prepared by the above-described CPES particle dispersion manufacturing method. Then, prepare an aqueous dispersion. In detail, it is as having demonstrated with the manufacturing method of above-mentioned CPES particle dispersion.

  The content of the crystalline polyester resin is preferably 5 to 30% by mass and more preferably 5 to 20% by mass with respect to the total amount of toner particles. Thereby, while obtaining the effect of improving the low-temperature fixability by improving the sharp melt property of the binder resin, it is possible to suppress a decrease in heat resistance due to the addition of the crystalline polyester resin.

(E) Preparation Step of Aqueous Dispersion of Colorant Fine Particles This step is a step that is performed as necessary when toner particles containing a colorant are desired, and the colorant is finely divided in an aqueous medium. In which an aqueous dispersion of fine colorant particles is prepared.

The aqueous dispersion of colorant fine particles can be obtained by dispersing the colorant in an aqueous medium in which a surfactant is added to a critical micelle concentration (CMC) or higher.
The colorant can be dispersed using mechanical energy, and the disperser to be used is not particularly limited. However, an ultrasonic disperser, a mechanical homogenizer, a manton gourin or a pressure homogenizer is preferably used. Examples thereof include medium dispersers such as a pressure disperser, a sand grinder, a Getzman mill, and a diamond fine mill.

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

<Colorant>
As the colorant, various known pigments and dyes can be used.
Examples of the carbon black that is one of the colorants include channel black, furnace black, acetylene black, thermal black, lamp black, and the like. Examples of black iron oxide include magnetite, hematite, and iron titanium trioxide. Can be mentioned.

  Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 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, 60, 70, 93, 95 and the like.

  Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 48: 3, 53: 1, 57: 1, 81: 4, 122, 139, 144, 149, 150, 166, 177, 178, 222, 238, 269, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment yellow 14, 17, 74, 93, 94, 138, 155, 156, 158, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, and the like.

The colorant for obtaining the toner of each color by the toner production method of the present invention can be used singly or in combination of two or more for each color.
The colorant used in the method for producing a toner of the present invention is obtained by dispersing fine colorant particles in the obtained toner particles so as to be preferably in the range of 1 to 10% by mass, more preferably in the range of 2 to 8% by mass. It is preferable to prepare an aqueous dispersion. When the content of the colorant is within the above range, the desired toner can be obtained with a desired coloring power, and the influence on the chargeability from the release of the colorant or adhesion to the carrier is minimized. Can do.

  In this step, an aqueous dispersion containing other additives than the colorant may be prepared. For example, when a toner particle containing a charge control agent is desired, an aqueous solution of the charge control agent containing the charge control agent in an aqueous medium may be prepared as necessary.

<Charge control agent>
Various known compounds can be used as the charge control agent. The content of the charge control agent is preferably in the range of 0 to 5% by mass in the toner particles obtained by the production method of the present invention, and more preferably in the range of 0 to 0.5% by mass. In addition, it is preferable to prepare an aqueous solution of the charge control agent.

(F) Toner particle forming step In this step, the crystalline polyester resin fine particles prepared in the step (d) are formed on the surface of the binder resin fine particles (2) formed by the third polymerization in the step (c). The colorant fine particles prepared in the step (e) are aggregated and further fused by heating to form toner particles.
Specifically, a coagulant having a critical coagulation concentration or more is added to an aqueous dispersion in which the binder resin fine particles (2), the crystalline polyester resin fine particles, and the colorant fine particles are dispersed, and then aggregated by heating. , Fuse. This forms toner particles.
The fusing temperature is preferably in the range of 70 to 95 ° C, for example.

(Flocculant)
The flocculant used in this step is not particularly limited, but those selected from metal salts such as alkali metal salts and alkaline earth metal salts are preferably used.
Examples of the metal salt include monovalent metal salts such as sodium, potassium, and lithium; divalent metal salts such as calcium, magnesium, manganese, and copper; and trivalent metal salts such as iron and aluminum.

  Specific metal salts can include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. It is particularly preferable to use a divalent metal salt. These can be used alone or in combination of two or more.

In addition to the toner particle forming step, it is also preferable to provide an aging step.
In the aging step, the toner particles obtained in the toner particle forming step are aged by heat energy until a desired shape is obtained.
Specifically, the aging treatment is performed by heating and stirring the system in which the toner particles are dispersed, thereby adjusting the shape of the toner particles by a heating temperature, a stirring speed, a heating time and the like until a desired circularity is obtained. Done.

(G) Cooling Step This step is a step of cooling the toner particle dispersion.
As a condition for the cooling treatment, it is preferable to cool at a cooling rate within a range of 1 to 20 ° C./min. The specific method of the cooling treatment is not particularly limited, and examples include a method of cooling by introducing a refrigerant from the outside of the reaction vessel, a method of cooling by directly introducing cold water into the reaction system, and the like. it can.

(H) Filtration / Washing Step This step involves solid-liquid separation of the toner particles from the cooled dispersion of toner particles, and a toner cake obtained by solid-liquid separation (aggregating toner particles in a wet state in a cake form) This is a step of removing adhering substances such as a surfactant and an aggregating agent from the aggregate).
The solid-liquid separation is not particularly limited, and a centrifugal separation method, a vacuum filtration method using Nutsche or the like, a filtration method using a filter press, or the like can be used. Further, in washing, it is preferable to wash with water until the electric conductivity of the filtrate reaches 10 μS / cm.

(I) Drying Step This step is a step of drying the washed toner cake, and can be carried out according to a drying step in a generally-known method for producing toner particles.
Specifically, examples of the dryer used for drying the toner cake include a spray dryer, a vacuum freeze dryer, and a vacuum dryer, and a stationary shelf dryer, a mobile shelf dryer, a fluidized bed, and the like. It is preferable to use a dryer, a rotary dryer, a stirring dryer or the like.

  The moisture of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less. In addition, when the dried toner particles are aggregated by a weak interparticle attractive force, 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.

(J) External additive addition step This step is a step that is performed as necessary when an external additive is added to the toner particles.
The above toner particles can be used as toners as they are, but in order to improve fluidity, chargeability, cleaning properties, etc., external additives such as fluidizing agents and cleaning aids are added to the toner particles. You may use it in the state.

<External additive>
Various external additives may be used in combination.
The total addition amount of these external additives is preferably in the range of 0.05 to 5 parts by mass, more preferably in the range of 0.1 to 3 parts by mass with respect to 100 parts by mass of the toner particles. It is said.
As the external additive mixing device, a mechanical mixing device such as a Henschel mixer or a coffee mill can be used.

[Toner obtained by the production method of the present invention]
The toner obtained by the production method of the present invention refers to an aggregate of toner particles. The toner particles obtained by the production method of the present invention are particles comprising a binder resin, a colorant and a release agent, and the binder resin is a polyester resin derived from the CPES particle dispersion obtained above. including. Further, as described above, the toner particles obtained by the production method of the present invention may further contain other components such as a charge control agent as necessary, so-called fluidizing agents, cleaning aids, etc. These external additives may be externally added.

<Glass transition temperature of toner>
The toner obtained by the production method of the present invention preferably has a glass transition temperature (Tg) in the range of 50 to 70 ° C, more preferably in the range of 55 to 65 ° C. When the glass transition temperature of the toner is in the above range, sufficient low-temperature fixing property and heat-resistant storage property can be reliably achieved. Further, when the glass transition temperature of the toner is in the above range, the heat resistance (thermal strength) of the toner is maintained, and as a result, sufficient heat storage stability and hot offset resistance can be reliably obtained. Conceivable.

<Melting point of toner>
The toner obtained by the production method of the present invention preferably has a melting point (Tm) in the range of 60 to 90 ° C, more preferably in the range of 65 to 80 ° C. When the melting point of the toner is in the above range, sufficient low-temperature fixing property and heat-resistant storage property can be surely achieved. In addition, by setting the melting point of the toner within the above range, it is considered that the heat resistance (thermal strength) of the toner is maintained well, and thereby sufficient heat storage stability can be secured. The glass transition temperature and melting point of the toner are measured in the same manner as the crystalline polyester resin.

<Toner particle size>
In the toner obtained by the production method of the present invention, the average particle diameter of the toner particles is preferably in the range of 3 to 8 μm, and more preferably in the range of 5 to 8 μm, for example, on a volume basis median diameter. is there. This average particle size can be controlled by the concentration of the flocculant used in the production, the amount of organic solvent added, the fusing time, and / or the composition of the binder resin. When the volume-based median diameter is in the above range, a very small dot image of 1200 dpi level can be faithfully reproduced.

The volume-based median diameter of the toner particles is measured and calculated using a measuring device in which “Multisizer 3” (manufactured by Beckman Coulter) is connected to a computer system equipped with data processing software “Software V3.51”. Value.
Specifically, 0.02 g of a measurement sample (toner) was added to 20 mL of a surfactant solution (for example, a surfactant obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). The solution is added to the solution and allowed to acclimate. Then, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is added to a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Then, inject with a pipette until the displayed concentration of the measuring device is 8%. By using this concentration, a reproducible measurement value can be obtained.
In the measurement apparatus, the measurement particle count is 25000, the aperture diameter is 100 μm, the frequency range is calculated by dividing the range of 2 to 60 μm, which is the measurement range, into 256, and the volume integrated fraction is 50 % Particle diameter is defined as the volume-based median diameter.

<Average circularity of toner particles>
In the toner obtained by the production method of the present invention, the average circularity of the individual toner particles constituting the toner is in the range of 0.930 to 1.000 from the viewpoint of stability of charging characteristics and low-temperature fixability. Is preferably within the range of 0.950 to 0.995. When the average circularity is within the above range, the individual toner particles are less likely to be crushed, the contamination of the frictional charge imparting member is suppressed, the toner chargeability is stabilized, and the image quality of the formed image is high. It will be a thing.

The average circularity of the toner particles is a value measured using “FPIA-2100” (manufactured by Sysmex).
Specifically, the measurement sample (toner) was blended with an aqueous solution containing a surfactant, dispersed by performing ultrasonic dispersion for 1 minute, and then subjected to measurement conditions HPF by “FPIA-2100” (manufactured by Sysmex). In the (high-magnification imaging) mode, imaging is performed in an appropriate density range of 3000 to 10,000 HPF detections, and the circularity is calculated for each toner particle according to the following equation (y). The average circularity of the toner particles is a value calculated by adding the circularity of each toner particle and 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 having the same projection area as the particle image) / (perimeter of the particle projection image)

<Developer>
The toner obtained by the production method of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.
When the toner is used as a two-component developer, the carrier uses magnetic particles made of a conventionally known material such as a metal such as iron, ferrite, or magnetite, or an alloy of such a metal with a metal such as aluminum or lead. In particular, ferrite particles are preferred.

Further, as the carrier, a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, a dispersion type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.
The average particle diameter of the carrier is preferably in the range of 20 to 100 μm, more preferably in the range of 25 to 80 μm in terms of volume-based median diameter.
The volume-based median 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.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

<Method for measuring water content before phase inversion emulsification>
The water content before phase inversion emulsification (the ratio of water in the solvent contained in the neutralized solution immediately before the dropping of the aqueous medium) measured in the preparation of the crystalline polyester resin fine particle dispersions (C1 to C10) described below is as follows. Measured.
First, five samples were prepared by mixing a solvent, a crystalline polyester resin, and water in an arbitrary ratio. Using gas chromatography, the peak area of water in each sample is calculated, and a calibration curve (the horizontal axis: the ratio of water in the sample solvent, the ratio of water in the actual sample solvent) Vertical axis: peak area of water obtained by gas chromatography). Next, gas chromatography measurement was performed using the target sample, and the ratio of water in the sample solvent was calculated from the obtained water peak area using a calibration curve.
Apparatus: Headspace autosampler “G1888” and gas chromatograph “Agilent 7890A GC system” (all manufactured by Agilent Technologies)
The measurement conditions are as follows.

<Head space autosampler setting conditions>
Oven temperature: 110 ° C
Needle temperature: 150 ° C
Transfer temperature: 150 ° C

<Gas chromatograph measurement conditions>
Column: DB-624 (inner diameter 250 μm, film thickness 1.4 μm, length 30 mm) (manufactured by Agilent Technologies)
Carrier: Helium gas Injection temperature: 200 ° C
Detector temperature: 250 ° C
Column flow rate: 1.5 mL / min Column temperature: Measured up to 230 ° C. at a heating rate of 10 ° C./min after holding at 40 ° C. for 2 minutes

[Preparation of crystalline polyester resin (c1)]
The raw material monomer and radical polymerization initiator of the following styrene / acrylic resin segment containing both reactive monomers were placed in a dropping funnel.
Styrene 36.0 parts by weight n-butyl acrylate 13.0 parts by weight Acrylic acid 2.0 parts by weight Polymerization initiator (di-t-butyl peroxide) 7.0 parts by weight

Moreover, the raw material monomer of the following crystalline polyester resin segment was put into a four-necked flask equipped with a nitrogen gas introduction tube, a dehydration tube, a stirrer, and a thermocouple, and heated to 170 ° C. to be dissolved.
Tetradecanedioic acid 315 parts by mass 1,4-butanediol 252 parts by mass

Next, the raw material monomer of the styrene / acrylic resin segment was dropped into the four-necked flask over 90 minutes with stirring, and after aging for 60 minutes, unreacted under reduced pressure (8 kPa). The raw material monomer of the styrene / acrylic resin segment was removed. The amount of the raw material monomer removed at this time was very small with respect to the raw material monomer charged as described above. Thereafter, 0.8 parts by mass of Ti (OBu) ₄ was added as a catalyst, the temperature was raised to 235 ° C., and the reaction was performed under normal pressure (101.3 kPa) for 5 hours and further under reduced pressure (8 kPa) for 1 hour. went. The crystalline polyester resin (c1) had a weight average molecular weight of 22,000 and a melting point of 79 ° C. The weight average molecular weight of the crystalline polyester resin was measured as described above using the apparatus “HLC-8120GPC” (manufactured by Tosoh Corporation) and the column “TSKguardcolumn + TSKgelSuperHZM-M3 series” (manufactured by Tosoh Corporation). Further, the melting point of the crystalline polyester resin was measured using a differential scanning calorimeter (DSC) “Diamond DSC” (manufactured by Perkin Elmer) as described above.

[Preparation of Crystalline Polyester Resin (c2)]
In the production of the crystalline polyester resin (c1), the addition amount of tetradecanedioic acid was changed to 440 parts by mass, and the addition amount of 1,4-butanediol was changed to 153 parts by mass. The same operation as in the production was performed to obtain a crystalline polyester resin (c2). The weight average molecular weight of the crystalline polyester resin (c2) was 24500, and the melting point was 85 ° C.

[Preparation of Crystalline Polyester Resin Fine Particle Dispersion (C1)]
122 parts by mass of crystalline polyester resin c1 was added to a mixed solution of 100 parts of methyl ethyl ketone (MEK) as a solvent and 54 parts by mass of pure water, and the mixture was stirred and dissolved at 70 ° C. for 60 minutes. Subsequently, 3 mass parts of 25 mass% sodium hydroxide aqueous solution which is a neutralizing agent was added with stirring, hold | maintaining the obtained solution at 70 degreeC. At this time, the water content before phase inversion emulsification calculated by measurement using the gas chromatography described above was 36% by mass. Subsequently, while maintaining the obtained solution at 70 ° C. (phase inversion emulsification temperature), 305 parts by mass of pure water at 70 ° C. was continuously added for 60 minutes (at an addition rate of 5.1 parts by mass / min). This was added to obtain a dispersion in which the oil-phase polyester-containing droplets were dispersed in the aqueous medium.

  Next, methyl ethyl ketone is removed from the dispersion by vacuum concentration, and then the dispersion is cooled to 30 ° C. Then, sodium dodecyl diphenyl ether disulfonate is added to the dispersion in an amount corresponding to 3 parts by mass relative to the resin solids, A crystalline polyester resin dispersion (C1) was obtained. It was 250 nm when the volume average particle diameter of the resin particles in the crystalline polyester resin dispersion C1 was measured by “Nanotrac Wave EX150” (manufactured by Microtrack Bell Co., Ltd.). Further, using “Nanotrac Wave EX150” (manufactured by Microtrack Bell Co., Ltd.), the coefficient of variation (CV value) of the resin particles in the crystalline polyester resin dispersion C1 is calculated using the measured volume average particle diameter. As a result, the CV value was 25%.

[Preparation of crystalline polyester resin fine particle dispersion C2, C3, C8]
The preparation of the crystalline polyester resin fine particle dispersion C1 was carried out in the same manner as the preparation of the crystalline polyester resin fine particle dispersion C1, except that the amount of pure water added was changed as shown in Table I. Polyester resin fine particle dispersions C2, C3, and C8 were prepared. Further, the volume average particle diameter and coefficient of variation (CV value) of the resin particles in each prepared crystalline polyester resin fine particle dispersion are shown in Table II.

[Preparation of Crystalline Polyester Resin Fine Particle Dispersions C4 to C7, C9, C10]
In the preparation of the crystalline polyester resin fine particle dispersion C1, the crystalline polyester resin c2 was used instead of the crystalline polyester resin c1, and the addition amounts of the crystalline polyester resin and pure water were changed as shown in Table I. Prepared the crystalline polyester resin fine particle dispersions C4 to C7, C9, and C10 in the same manner as the preparation of the crystalline polyester resin fine particle dispersion C1. In the preparation of the crystalline polyester resin fine particle dispersion C4, the phase inversion emulsification temperature was changed to 65 ° C. Further, the volume average particle diameter and coefficient of variation (CV value) of the resin particles in each prepared crystalline polyester resin fine particle dispersion are shown in Table II.

[Preparation of Amorphous Resin Fine Particle Dispersion (X1)]
(1) First-stage polymerization Into a 5 L reaction vessel equipped with a stirrer, temperature sensor, cooling pipe and nitrogen introduction device, 8 parts by mass of sodium dodecyl sulfate and 3000 parts by mass of ion-exchanged water were charged and stirred at 230 rpm under a nitrogen stream. The internal temperature was raised to 80 ° C. while stirring at a speed. After raising the temperature, 10 parts by mass of potassium persulfate dissolved in 200 parts by mass of ion-exchanged water was added, the temperature was again set to 80 ° C., and a monomer mixture having the following composition was added dropwise over 1 hour, Polymerization was carried out by heating and stirring at 80 ° C. for 2 hours to prepare a dispersion (x1) of resin fine particles.
Styrene 480 parts by mass n-butyl acrylate 250 parts by mass Methacrylic acid 68 parts by mass

(2) Second-stage polymerization In a 5 L reaction vessel equipped with a stirrer, temperature sensor, cooling pipe and nitrogen introducing device, 7 parts by mass of polyoxyethylene (2) sodium dodecyl ether sulfate was dissolved in 3000 parts by mass of ion-exchanged water. A solution prepared by dissolving 80 parts by mass (in terms of solid content) of a resin fine particle dispersion (x1), a monomer having the following composition, and a release agent at 90 ° C. Were added and dispersed for 1 hour using a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path to prepare a dispersion containing emulsified particles (oil droplets).
Styrene (St) 285 parts by weight n-butyl acrylate (BA) 95 parts by weight Methacrylic acid (MAA) 20 parts by weight n-octyl-3-mercaptopropionate 8 parts by weight Release agent: behenyl behenate (melting point 73 ° C.) 190 parts by weight

  Next, an initiator solution prepared by dissolving 6 parts by mass of potassium persulfate in 200 parts by mass of ion-exchanged water is added to the dispersion, and polymerization is performed by heating and stirring the system at 84 ° C. for 1 hour. A dispersion (x2) of resin fine particles was prepared.

(3) Third-stage polymerization Further, 400 parts by mass of ion-exchanged water was added to the resin fine particle dispersion (x2) and mixed well, and then 11 parts by mass of potassium persulfate was dissolved in 400 parts by mass of ion-exchanged water. The solution was added, and a monomer mixed solution having the following composition was added dropwise over one hour under a temperature condition of 82 ° C. After completion of the dropwise addition, polymerization was carried out by heating and stirring for 2 hours, followed by cooling to 28 ° C. to prepare an amorphous resin fine particle dispersion (X1) composed of a vinyl resin (styrene-acrylic resin).
Styrene (St) 437 parts by mass n-butyl acrylate (BA) 17 parts by mass n-octyl acrylate 143 parts by mass Acrylic acid (AA) 52 parts by mass n-octyl-3-mercaptopropionate 8 parts by mass

[Preparation of Colorant Fine Particle Dispersion (Bk)]
90 parts by weight of sodium dodecyl sulfate is dissolved in 1600 parts by weight of ion-exchanged water while stirring, and while stirring this solution, 420 parts by weight of carbon black “Regal 330R” (manufactured by Cabot) is gradually added. A colorant fine particle dispersion liquid [Bk] in which colorant fine particles are dispersed was prepared by performing a dispersion treatment using “CLEAMIX” (manufactured by M Technique Co., Ltd.). When the volume-based median diameter of the colorant fine particles in the colorant fine particle dispersion (Bk) was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), it was 120 nm.

[Preparation of Amorphous Polyester Resin (s1)]
A raw material monomer of the following addition polymerization resin (styrene-acrylic resin: StAc) containing both reactive monomers and a radical polymerization initiator were placed in a dropping funnel.
Styrene 80 parts by mass n-butyl acrylate 20 parts by mass Acrylic acid 10 parts by mass Polymerization initiator (di-t-butyl peroxide) 16 parts by mass

In addition, the raw material monomer of the following polycondensation resin (amorphous polyester resin) was placed in a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and heated to 170 ° C. to dissolve. .
Bisphenol A propylene oxide 2-mole adduct 285.7 parts by mass Terephthalic acid 66.9 parts by mass Fumaric acid 47.4 parts by mass

Next, the raw material monomer of the addition polymerization resin is dropped into the four-necked flask over 90 minutes with stirring, and after aging for 60 minutes, unreacted addition polymerization monomer under reduced pressure (8 kPa). Was removed. Thereafter, 0.4 parts by mass of Ti (OBu) ₄ was added as an esterification catalyst, the temperature was raised to 235 ° C., and the reaction was performed at normal pressure (101.3 kPa) for 5 hours and further under reduced pressure (8 kPa) for 1 hour. went. Next, after cooling to 200 ° C., the reaction was performed under reduced pressure (20 kPa) until the desired softening point was reached. Next, the solvent was removed to obtain a shell resin (s1) as an amorphous resin. With respect to the obtained resin for shell (s1), the glass transition temperature (Tg) was 60 ° C., and the weight average molecular weight (Mw) was 30000.

[Preparation of Amorphous Polyester Resin Fine Particle Dispersion (S1)]
After mixing 150 parts by mass of amorphous polyester resin s1 with 100 parts of methyl ethyl ketone, the mixture was stirred and dissolved at 70 ° C. for 60 minutes, and then 3 parts by mass of a 25% by mass sodium hydroxide aqueous solution as a neutralizer was added to the resulting solution. Then, 370 parts by mass of pure water at 70 ° C. is added to the obtained dispersion over 80 minutes to obtain a dispersion in which the oil-phase polyester-containing droplets are dispersed in an aqueous medium. It was.

  Next, methyl ethyl ketone is removed from the dispersion by vacuum concentration, and then the dispersion is cooled to 30 ° C. Then, sodium dodecyl diphenyl ether disulfonate is added to the dispersion in an amount corresponding to 3 parts by mass relative to the resin solids, An amorphous polyester resin dispersion S1 which is an aqueous polyester particle dispersion was obtained. It was 148 nm when the volume average particle diameter of the resin particles in the amorphous polyester resin dispersion S1 was measured by “Nanotrac Wave EX150” (manufactured by Microtrack Bell Co., Ltd.).

<< Manufacture of Developer 1 >>
In a reaction vessel equipped with a stirrer, a temperature sensor and a cooling tube, 200 parts by mass of amorphous resin fine particle dispersion (X1) in terms of solid content, and 14 parts by weight of colorant fine particle dispersion in terms of colorant solid content ( Bk) and 2000 parts by mass of ion-exchanged water were added, and then a 5 mol / L aqueous sodium hydroxide solution was further added to the reaction vessel, so that the pH of the mixed solution in the reaction vessel was 10 (temperature 30 ° C.). It was adjusted.

  Next, an aqueous solution in which 60 parts by mass of magnesium chloride was dissolved in 60 parts by mass of ion-exchanged water was added to the above mixed solution over 10 minutes at 30 ° C. with stirring. Next, the obtained mixed liquid is heated to 80 ° C. over 90 minutes, and then 20 parts by mass of the crystalline polyester resin fine particle dispersion (C1) in terms of solid content is added to the mixed liquid over 20 minutes. Then, the number of agitation is appropriately reduced, and the particle size of the associated particles is measured with “Coulter Multisizer 3” (manufactured by Beckman Coulter, Inc.). Went.

  Next, 37 parts by mass (in terms of solid content) of amorphous polyester resin particle dispersion (S1) for shell layer was added over 30 minutes, and when the supernatant of the reaction solution became transparent, 190 parts by mass of sodium chloride was added. An aqueous solution dissolved in 760 parts by mass of ion-exchanged water was added to stop particle growth (aggregation). Next, the obtained dispersion was heated and stirred at 80 ° C. to advance the fusion of the particles. When the average circularity of the particles in the dispersion was measured using a measuring device “FPIA-2100” (manufactured by Sysmex) (the number of detected HPF was 4000), the average circularity reached 0.955. Then, the dispersion was cooled to 30 ° C. to stop the fusion of the particles. Thus, a toner dispersion liquid 1 containing toner base particles 1 was obtained.

  The toner base particles 1 are separated from the obtained toner dispersion 1, washed and dried, and 1% by mass of hydrophobic silica particles and 1.2% by mass of hydrophobic titanium oxide particles are added to the obtained toner base particles 1. Then, using a Henschel mixer, mixing was performed for 20 minutes under the condition of a peripheral speed of the rotating blades of 24 m / s, and the obtained mixed powder was passed through a 400 mesh sieve to separate coarse powder. Thus, toner particles 1 in which an external additive was adhered to the surface of toner base particles 1 were obtained. Further, to the toner particles 1, a ferrite carrier having a volume average particle diameter of 60 μm coated with a silicone resin was added and mixed so that the toner particle concentration was 6% by mass. In this way, Developer 1 which is a two-component developer was produced.

<< Manufacture of Developers 2 to 10 >>
In the production of the developer 1, in the same manner as in the production method of the developer 1 except that the crystalline polyester resin fine particle dispersions C2 to C10 are used instead of the crystalline polyester resin fine particle dispersion C1. Ten productions were made.

<Evaluation method>
[Evaluation machine]
Developers 1 to 10 were loaded into a developing device of a commercially available color multifunction peripheral “bizhub PRESS C1060” (manufactured by Konica Minolta), and a test image was formed and evaluated.

[Fixation evaluation]
In an environment of normal temperature and normal humidity (temperature 20 ° C., relative humidity 50% RH), an unfixed solid image (adhesion amount 11.3 g / m2) on an A4-sized mondi color copy 90 g / m ² (manufactured by mondi) in an image forming apparatus. m ² ) was formed. Next, the surface temperature of the pressure roller of the fixing device was set to 100 ° C., and the surface temperature of the heating roller was changed in a range of 130 to 170 ° C. in steps of 2 ° C. to perform fixing.

The printed matter obtained in the fixing experiment at each fixing temperature was folded by a folding machine so as to apply a load to the solid image, and compressed air of 0.35 MPa was sprayed. The crease portion was ranked according to the following evaluation criteria, and among the fixing experiments of rank 3 or higher, the fixing temperature in the fixing experiment with the lowest fixing temperature was set as the minimum fixing temperature. The lower the lower limit fixing temperature, the stronger the folding resistance, that is, the better the image strength.
The evaluation results of the obtained image intensity are shown in Table III below. In addition, the evaluation result of the image strength was Δ or more (lower limit fixing temperature 151 ° C. or higher and lower than 156 ° C.) or higher.

(Folding fixability evaluation criteria)
Rank 5: No peeling at all.
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: Large peeling according to the crease.

(Image intensity evaluation criteria)
A: The lower limit fixing temperature is less than 146 ° C.
○: The lower limit fixing temperature is 146 ° C. or more and less than 151 ° C.
Δ: Lower limit fixing temperature is 151 ° C. or higher and lower than 156 ° C.
X: The lower limit fixing temperature is 156 ° C. or higher.

  From the above evaluation, it was confirmed that a crystalline polyester resin fine particle dispersion having a small particle size and a sharp particle size distribution can be obtained by using the method for producing an aqueous dispersion of a crystalline polyester resin of the present invention. . Furthermore, it was confirmed that the toner produced using the crystalline polyester resin fine particle dispersion obtained by the present invention has good fixability.

On the other hand, in the crystalline polyester resin fine particle dispersion C8 of the comparative example, the water content in the solution before phase inversion emulsification is too small, so that the neutralizing agent is poorly mixed and the carboxy group of the crystalline polyester resin is sufficiently removed. Since the particles could not be dissociated, the emulsified particles became large and the particle size distribution was broad.
Further, the crystalline polyester resin fine particle dispersion C9 of Comparative Example could not carry out phase inversion emulsification because the amount of water in the solution before the phase inversion emulsification was excessive. This is presumably because the co-phase state before phase inversion was not stably formed.
Moreover, since the crystalline polyester resin fine particle dispersion C10 of the comparative example had a low phase inversion emulsification temperature, the crystalline polyester resin was not completely dissolved in the solution, and phase inversion emulsification could not be performed.

Claims (7)

A dissolution step of dissolving the crystalline polyester resin in a solvent;
A neutralizing step of adding a neutralizing agent to the solution obtained in the dissolving step;
A phase inversion emulsification step in which an aqueous medium is dropped into the neutralization solution obtained in the neutralization step, and phase inversion emulsification is performed;
In the phase inversion emulsification step, the ratio of water in the solvent contained in the neutralization solution immediately before the dropping of the aqueous medium is in the range of 12 to 50% by mass,
A method for producing a crystalline polyester resin aqueous dispersion, wherein the phase inversion emulsification step is performed at a temperature of 20 ° C. or lower than the melting point of the crystalline polyester resin.   The method for producing an aqueous crystalline polyester resin dispersion according to claim 1, wherein the dissolving step is performed at a temperature of 20 ° C or lower than the melting point of the crystalline polyester resin.   The method for producing a crystalline polyester resin aqueous dispersion according to claim 1 or 2, wherein the neutralization step is performed at a temperature equal to or higher than a temperature 20 ° C lower than the melting point of the crystalline polyester resin. The volume average particle diameter of the crystalline polyester resin particles constituting the crystalline polyester resin aqueous dispersion is in the range of 50 to 500 nm, and
The coefficient of variation (CV value) of the crystalline polyester resin particles is in the range of 10 to 60%, and the crystalline polyester resin aqueous solution according to any one of claims 1 to 3 A method for producing a dispersion.   The said melt | dissolution process is a process of dissolving 50-300 mass parts of said crystalline polyester resins in 100 mass parts of said solvents, The any one of Claim 1 to 4 characterized by the above-mentioned. A method for producing an aqueous dispersion of crystalline polyester resin.   6. The crystalline polyester resin includes a styrene / acryl modified polyester resin formed by bonding a crystalline polyester resin segment and a styrene / acrylic resin segment. The manufacturing method of crystalline polyester resin aqueous dispersion as described in claim | item.   It has the process of aggregating and fusing the crystalline polyester resin particle contained in the crystalline polyester resin aqueous dispersion as described in any one of Claim 1- Claim 6 in an aqueous medium, It is characterized by the above-mentioned. A method for producing a toner for developing an electrostatic image.

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