JP2008201865A - Aqueous dispersion of polyester resin fine particle, and toner produced by using the aqueous dispersion of the polyester resin fine particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dispersion of polyester resin fine particles, substantially free from an organic solvent and having excellent preservation stability in hot condition. <P>SOLUTION: The aqueous dispersion of the polyester resin fine particles has ≤100 μg/g content of an organic solvent having ≤100°C boiling point in the aqueous dispersion of the polyester resin fine particles, the peak top of a main peak within the range of ≥3,500 and ≤15,000 molecular weight in the molecular weight distribution of tetrahydrofuran-dissolvable components in the polyester resin particles, measured by a gel-permeation chromatography, and ≥5,000 and ≤50,000 weight average molecular weight, and contains ≥0.1% and ≤20.0% component having ≥500 and <2,000 molecular weight based on the whole components. The polyester resin fine particles have ≥0.02 μm and ≤1.00 μm 50% particle diameter based on volume distribution. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an aqueous dispersion of fine polyester resin particles used in fields such as electrophotographic toners, printing materials such as ink, paints, adhesives, pressure-sensitive adhesives, fiber processing, papermaking / paper processing, civil engineering, and the like. The present invention relates to an electrophotographic toner produced using an aqueous dispersion of fine particles.

  As a binder resin for an electrophotographic toner, a polyester resin is known to have an advantageous effect on fixing properties because of its melt viscosity characteristics and hardness, and is widely used as a binder resin for color toners. Further, with the shift to chemical toners, it is desired to apply polyester resins to toners using an emulsion aggregation method. An electrophotographic toner using the emulsion aggregation method is produced by separately finely dividing a toner functional substance such as a resin, a pigment, and a wax, and uniformly recombining them. On the other hand, the volume average particle diameter of the electrophotographic toner is usually 3 to 10 μm. Therefore, when a polyester resin is used in the emulsion aggregation method, an aqueous dispersion of polyester resin fine particles having a volume average particle size of 1 μm or less is required.

A high molecular weight polyester resin composed of a polybasic acid component and a polyhydric alcohol component is used as a film-forming resin as a film processability, resistance to organic solvents (solvent resistance), weather resistance, and resistance to various substrates. Because of its excellent adhesion, it is used in large quantities as a binder component in the fields of paints, inks, adhesives, coating agents and the like.
In recent years, the use of organic solvents has tended to be restricted from the standpoints of environmental protection, resource conservation, dangerous goods regulations by the Fire Service Act, and workplace environment improvement. Polyester resin is used as a polyester resin binder that can be used in the above applications. Development of an aqueous dispersion of a polyester resin finely dispersed in an aqueous medium has been actively conducted.
As an example, an aqueous dispersion of a polyester resin dispersed in an aqueous medium by neutralizing a polyester resin having a relatively low acid value and a high molecular weight with a basic compound has been proposed (for example, Patent Document 1). To 3).
Although all of these have reduced the usage-amount of the organic solvent, the amount of the organic solvent is manufactured using 0.5 mass% or more with respect to the aqueous dispersion of the polyester resin. Conventionally, an aqueous dispersion of a polyester resin has been produced using an organic solvent. Among the methods for obtaining an aqueous dispersion of a polyester resin, the following methods are known as methods using an organic solvent. (1) A method of obtaining an aqueous dispersion of a polyester resin by dissolving a water-dispersible polyester resin in an organic solvent and adding water with stirring. (2) A method of dispersing a water-dispersible polyester resin in a mixture of an organic solvent and water (see, for example, Patent Document 4).
Using an organic solvent, once the aqueous dispersion of the polyester resin containing the organic solvent is produced, the organic solvent is distilled off from the aqueous dispersion under normal pressure or reduced pressure. There is also known a method of producing an aqueous dispersion of a polyester resin in a reduced form (see, for example, Patent Document 5).
However, it is difficult to completely remove the organic solvent from the aqueous dispersion of the polyester resin, and even if it is possible, the process and equipment become complicated and are not practical.

Moreover, the method of manufacturing the aqueous dispersion of a polyester resin, without using an organic solvent is also known (for example, refer patent documents 6-11).
However, these methods tend to cause the following problems, for example. (1) The resin is limited to a specific polyester containing a sulfone group (see, for example, Patent Documents 6, 7, and 8). (2) Since a strong shearing force is applied at a high temperature (for example, see Patent Documents 9 and 10), the polyester resin undergoes hydrolysis, and the molecular weight distribution of the obtained polyester resin increases on the low molecular weight side with a molecular weight of 2,000 or less. To do.
On the other hand, there is known a method for producing an aqueous dispersion in the presence of a basic substance so as not to cause the hydrolysis (see, for example, Patent Document 11), but the resin is a crystalline polyester having a relatively low melting temperature. It is limited to.
JP-A-9-296100 JP 2000-26709 A JP 2000-313793 A Japanese Examined Patent Publication No. 61-58092 Japanese Patent Publication No. 64-10547 JP-A-8-245769 JP 2001-305996 A JP 2002-82485 A JP 2000-191892 A JP 2004-189765 A JP 2004-287149 A

An object of the present invention is to provide an aqueous dispersion of polyester resin fine particles that is substantially free of an organic solvent that has solved the problems of the prior art as described above and has excellent heat-resistant storage stability.
An object of the present invention is to provide an aqueous dispersion of polyester resin microparticles having a specific molecular weight distribution and a specific particle diameter so as to satisfy fixing offset property and heat-resistant storage stability, when substantially containing no organic solvent, and used as a toner. Is to provide.
An object of the present invention is to provide a toner produced by an emulsion aggregation method using an aqueous dispersion of polyester resin fine particles substantially free of an organic solvent.

As a result of intensive studies to solve such problems, the present inventors have found that an aqueous dispersion of polyester resin fine particles having substantially no organic solvent, having a specific molecular weight distribution, and a specific particle size. However, the present inventors have found that the above-mentioned problems can be achieved and achieved the present invention.
That is, the present invention is as follows.
(1) An aqueous dispersion of polyester resin fine particles, wherein the content of the organic solvent having a boiling point of 100 ° C. or less in the aqueous dispersion of polyester resin fine particles is 100 μg / g or less,
In the molecular weight distribution measured by gel permeation chromatography (GPC) of the polyester resin fine particles in tetrahydrofuran (THF), the peak top of the main peak exists in the molecular weight range of 3,500 to 15,000, A weight average molecular weight of 5,000 or more and 50,000 or less, a component having a molecular weight of 500 or more and less than 2,000 is contained in an amount of 0.1% or more and 20.0% or less of the total component amount, and the volume distribution standard of the polyester resin fine particles An aqueous dispersion of polyester resin fine particles, wherein the 50% particle size of the polyester resin is 0.02 μm or more and 1.00 μm or less.
(2) The aqueous dispersion of polyester resin fine particles according to (1), wherein the polyester resin fine particles have a volume distribution standard 50% particle size of 0.02 μm or more and 0.40 μm or less.
(3) The polyester resin fine particles according to (1) or (2), wherein the content of the organic solvent having a boiling point of 200 ° C. or less in the aqueous dispersion of the polyester resin fine particles is 100 μg / g or less. Aqueous dispersion.
(4) In the molecular weight distribution measured by gel permeation chromatography (GPC) of tetrahydrofuran (THF) soluble matter of the polyester resin fine particles, the component having a molecular weight of 500 or more and less than 2,000 is 0.1% of the total component amount. The aqueous dispersion of polyester resin fine particles according to any one of (1) to (3), wherein the content is 15.0% or less.
(5) An agglomeration step in which an aqueous dispersion of polyester resin fine particles and a colorant are mixed and the polyester resin fine particles and the colorant are aggregated in an aqueous medium to form an aggregate; and the aggregate is heated and fused. Wherein the polyester resin fine particle aqueous dispersion is a polyester resin fine particle aqueous dispersion according to any one of (1) to (4). Toner.

  According to the present invention, it is possible to provide an aqueous dispersion of polyester resin fine particles that are substantially free of an organic solvent and excellent in heat-resistant storage stability. In addition, according to the present invention, an aqueous dispersion of polyester resin fine particles having a specific molecular weight distribution and a specific particle diameter for satisfying fixing offset property and heat-resistant storage stability when substantially used as a toner without containing an organic solvent. Can be provided.

Hereinafter, the present invention will be described in detail.
The aqueous dispersion of polyester resin fine particles of the present invention has a content of an organic solvent having a boiling point of 100 ° C. or lower in the aqueous dispersion of polyester resin fine particles of 100 μg / g or less, and the polyester resin fine particles are soluble in tetrahydrofuran (THF). In the molecular weight distribution measured by gel permeation chromatography (GPC) for 1 minute, the peak top of the main peak exists in the molecular weight range of 3,500 to 15,000, and the weight average molecular weight is 5,000 to 50,000. The component having a molecular weight of 500 or more and less than 2,000 is contained in an amount of 0.1% or more and 20.0% or less of the total component amount, and the 50% particle size based on the volume distribution of the polyester resin fine particles is 0.02 μm or more and 1. It is characterized by being not more than 00 μm.
As described above, the polyester resin fine particles of the present invention have a peak top of the main peak in the molecular weight range of 3,500 to 15,000 in the molecular weight distribution measured by GPC of THF-soluble matter. When the peak top of the main peak is present at a molecular weight of less than 3,500, the thermal stability of the resin fine particles is poor. In addition, the aqueous dispersion tends to cause aggregation and separation at 40 ° C. or higher. Furthermore, the thermal stability when the polyester resin fine particles and the like are agglomerated and combined into a toner tends to deteriorate.
On the other hand, when the peak top of the main peak exceeds a molecular weight of 15,000, it is difficult to obtain low temperature fixability when the polyester resin fine particles are used as a toner.
Similarly, the weight average molecular weight (Mw) of the polyester resin fine particles is 5,000 or more and 50,000 or less (preferably 5,000 or more and 30,000 or less). When the weight average molecular weight (Mw) is less than 5,000, the thermal stability of the polyester resin fine particles tends to be poor. On the other hand, when the weight average molecular weight (Mw) exceeds 50,000, it is difficult to impart a sufficient acid value to the polyester resin, and it is difficult to obtain low-temperature fixability when used as a toner.
Furthermore, the polyester resin fine particles contain a component having a molecular weight of 500 or more and less than 2,000, 0.1% or more and 20.0% or less of the total component amount (preferably 0.1% or more and 15.0% or less of the total component amount). To do.
If the amount of the component having a molecular weight of 500 or more and less than 2,000 exceeds 20.0%, the powder characteristics, particularly the thermal stability, of the toner is likely to deteriorate.
In order to adjust the molecular weight, the weight average molecular weight (Mw), and the molecular weight of 500 to less than 2,000 in the main peak to the above ranges, the composition of the polyester resin is selected and It is recommended to select a method that does not cause hydrolysis or molecular chain breakage during atomization.

In the present invention, the 50% particle size on the basis of volume distribution of the polyester resin fine particles in the aqueous dispersion is 0.02 μm or more and 1.00 μm or less (preferably 0.02 μm or more and 0.40 μm or less).
When the 50% particle size based on the volume distribution exceeds 1.00 μm, the resin fine particles are not stable in storage and are liable to cause sedimentation separation. In addition, when the toner is manufactured by the emulsion aggregation method using the polyester resin fine particles, the toner particle diameter is 3 to 7 μm, and therefore the presence of particles of 1.00 μm or more indicates that the toner composition is uniform. It is difficult to keep sex. Therefore, in consideration of toner production, the 50% particle size based on the volume distribution is preferably 0.40 μm or less. In order to adjust the 50% particle size of the polyester resin fine particles based on the volume distribution within the above range, the fine particles may be atomized by a high-pressure impact force or a high-speed shearing force while being heated to a temperature higher than the melting temperature of the polyester.

  In the present invention, the content of the organic solvent having a boiling point of 100 ° C. or less in the aqueous dispersion of polyester resin fine particles is 100 μg / g or less (preferably the content of the organic solvent having a boiling point of 200 ° C. or less is 100 μg / g g or less). When the amount is outside the above range, a process for removing and recovering the organic solvent is newly required when the toner is produced by the emulsion aggregation method, which imposes a load on wastewater treatment measures. In addition, when aggregation is performed using sodium chloride as a flocculant, the particle size distribution of the aggregate tends to be broad.

Although the method to manufacture the aqueous dispersion of the said polyester resin microparticles | fine-particles is demonstrated below, it is not limited to these.
The polyester resin fine particle aqueous dispersion is obtained by dry pulverization (preliminary pulverization) of polyester resin with a jet mill or mechanical pulverizer, etc., and mixing with an aqueous medium, followed by atomization with a high-pressure impact disperser or the like. It is done. At this time, it is preferable to add a basic substance, a surfactant or the like having an appropriate concentration for preventing hydrolysis.

  The polyester resin comprises a polybasic acid component and a polyhydric alcohol component. Polybasic acid components include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid and other aromatic dicarboxylic acids, oxalic acid, succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dodecane Saturated or unsaturated aliphatic dicarboxylic acid such as diacid, hydrogenated dimer acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, dimer acid, 1,4- Mention may be made of alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornenedicarboxylic acid and its anhydride, tetrahydrophthalic acid and its anhydride. it can.

  Further, as the polybasic acid, a tribasic or higher polybasic acid can be used. Examples of such tribasic or higher polybasic acids include trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, trimesic acid, ethylene glycol bis (Anhydro trimellitate), glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid and the like may be contained. The trifunctional or higher polybasic acid is preferably 10 mol% or less, more preferably 8 mol% or less, and more preferably 5 mol% or less in the polybasic acid component from the viewpoint of maintaining good processability of the resin film. Particularly preferred.

Examples of the polyhydric alcohol component of the polyester resin include aliphatic glycol, alicyclic glycol, ether bond-containing glycol and the like. Aliphatic glycols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl Examples include glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-ethyl-2-butylpropanediol. Examples of the alicyclic glycol include 1,4-cyclohexanedimethanol. Examples of the ether bond-containing glycol include diethylene glycol, triethylene glycol, dipropylene glycol, and ethylene oxide or propylene oxide in two phenolic hydroxyl groups of bisphenols such as 2,2-bis (4-hydroxyethoxyphenyl) propane. Examples include glycols obtained by adding 1 to several moles of each, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like. In addition, as the trifunctional or higher polyhydric alcohol, for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like may be included.

  In addition, the polyester resin may contain, as necessary, fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, and ester-forming derivatives thereof, benzoic acid, p-tert-butyl. Monocarboxylic acids such as benzoic acid, cyclohexane acid and 4-hydroxyphenyl stearic acid, monoalcohols such as stearyl alcohol and 2-phenoxyethanol, hydroxycarboxylic acids such as ε-caprolactone, lactic acid, β-hydroxybutyric acid and p-hydroxybenzoic acid Or an ester-forming derivative thereof may be copolymerized.

Although the acid value of the said polyester resin is not specifically limited, 3-35 mgKOH / g is preferable and 8-25 mgKOH / g is more preferable. When the acid value exceeds 35 mgKOH / g, the charge-up in a low-humidity environment tends to be remarkable. On the other hand, when the acid value is less than 3 mgKOH / g, the chargeability is low and is not suitable for toner use. .
Moreover, the hydroxyl group may be introduce | transduced into the said polyester resin.
Further, the glass transition temperature (hereinafter referred to as Tg) of the polyester resin is not particularly limited, but is preferably 50 to 75 ° C, more preferably 52 to 70 ° C.

  In the present invention, the polyester resin is obtained by polycondensation of one or more of the above polybasic acid components and one or more of the polyhydric alcohol components, depolymerization with the polybasic acid component after polycondensation, It can be produced by a known method such as adding an acid anhydride after the condensation. A hydroxyl group can also be introduced by the same method.

  In the toner of the present invention, an aqueous dispersion of the polyester resin fine particles and a colorant are mixed at least, and the polyester resin fine particles and the colorant are aggregated to a desired toner particle size in an aqueous medium to form an aggregate. It is obtained by a production method including a step and a step of heating and fusing the aggregate.

Although the said manufacturing method is not specifically limited, The following methods can be illustrated suitably.
(Aggregation process)
In the aggregation step, the polyester resin fine particle aqueous dispersion is mixed with toner components such as a colorant and a release agent to prepare a mixed solution. Next, aggregated particles are formed in the mixed solution to prepare an aggregated particle dispersion. The agglomerated particles can be formed in the mixed solution by adding, for example, a pH adjusting agent, a flocculant, and a stabilizer to the mixed solution and mixing them, and appropriately adding temperature, mechanical power and the like.
Examples of the pH adjusting agent include alkalis such as ammonia and sodium hydroxide, and acids such as nitric acid and citric acid. Examples of the flocculant include monovalent metal salts such as sodium and potassium; divalent metal salts such as calcium and magnesium; trivalent metal salts such as iron and aluminum; and alcohols such as methanol, ethanol and propanol. can give. Examples of the stabilizer mainly include a surfactant itself or an aqueous medium containing the surfactant.
The addition / mixing of the flocculant and the like is preferably performed at a temperature not higher than the glass transition point (Tg) of the polyester resin fine particles contained in the mixed solution. When the above mixing is performed under this temperature condition, aggregation proceeds in a stable state. The said mixing can be performed using a well-known mixing apparatus, a homogenizer, a mixer, etc.
The average particle size of the aggregated particles formed here is not particularly limited, but it is usually preferable to control the average particle size to be approximately the same as the average particle size of the toner to be obtained. The control can be easily performed, for example, by appropriately setting and changing the temperature and the stirring and mixing conditions. In the above aggregation step, aggregated particles having an average particle size substantially the same as the average particle size of the toner are formed, and an aggregated particle dispersion liquid in which the aggregated particles are dispersed is prepared.

(Heating / fusion process)
The heating / fusion step is a step of heating and aggregating the aggregated particles. Before entering the heating / fusion step, the pH adjusting agent, the surfactant and the like can be appropriately added to prevent fusion between the toner particles.
The heating temperature may be any temperature from the glass transition point (Tg) of the resin contained in the aggregated particles to the decomposition temperature of the resin.
As the heating / fusion time, a short time is sufficient if the heating temperature is high, and a long time is required if the heating temperature is low. That is, the fusion time depends on the temperature of the heating and cannot be defined in general, but is generally 30 minutes to 10 hours.
In the present invention, toner particles are obtained by washing, filtering, drying, and the like of the toner obtained after completion of the heating / fusion process under appropriate conditions. Further, a shearing force is applied to the surface of the obtained toner particles by applying inorganic particles such as silica, alumina, titania, calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin in a dry state. It may be added. These inorganic particles and resin particles function as external additives such as fluidity aids and cleaning aids.

The physical property measuring method in the present invention will be described below.
<Measurement of Molecular Weight Distribution and Weight Average Molecular Weight (Mw) Measured by Gel Permeation Chromatography (GPC) of Polyester Resin and Polyester Resin Fine Particles in Tetrahydrofuran (THF)>
The molecular weight distribution and weight average molecular weight (Mw) measured by GPC of the polyester resin and polyester resin fine particles in THF are determined as follows.
The column is stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml / min, and about 100 μl of THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, a product with a molecular weight of about 10 ² to 10 ⁷ manufactured by Tosoh Corporation or Showa Denko is used, and at least about 10 standard polystyrene samples are suitably used. is there. An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, a combination of shodex GPC KF-801, 802, 803, 804, 805, 806, 807, 800P manufactured by Showa Denko, A combination of TSKgel G1000H (HXL), G2000H (HXL), G3000H (HXL), G4000H (HXL), G5000H (HXL), G6000H (HXL), G7000H (HXL), and TSKguardcolumn is given.
The sample is prepared as follows.
Put polyester resin or air-dried polyester resin fine particles (sample) in tetrahydrofuran (THF), let stand for several hours, shake well, mix well with THF (until the sample is no longer united), and let stand for more than 12 hours Put. At this time, the standing time in THF is set to be 24 hours or more. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5: manufactured by Tosoh Corporation, Excro Disc 25CR: manufactured by Gelman Science Japan Co., Ltd., etc. can be used) is passed. This is used as a GPC sample. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.
Further, from the created molecular weight distribution, it is possible to derive the molecular weight (Mp) at which the peak top of the main peak exists, and the component amount having a molecular weight of 500 or more and less than 2,000 with respect to the total component amount. The component amount having a molecular weight of 500 or more and less than 2,000 with respect to the total component amount can be calculated, for example, by subtracting the frequency distribution accumulated value up to the molecular weight 500 from the frequency distribution accumulated value up to the molecular weight 2000.

<Measurement of glass transition point of polyester resin>
The glass transition point (Tg) of the polyester resin can be measured using a differential scanning calorimeter (DSC) measuring device. In DSC measurement, from the measurement principle, it is preferable to measure with a differential scanning calorimeter of high accuracy internal heat type input compensation type. The measurement method is performed according to ASTM D3418-82. Specifically, the glass transition point (Tg (° C.)) is calculated from the DSC curve measured when the temperature is raised and lowered once, the previous history is taken, and the temperature is raised at 10 ° C./min. The central value of the intersection point between the baseline before and after the endotherm and the tangent to the endothermic curve is defined as Tg (° C.).

<Measurement of acid value of polyester resin>
The acid value of the polyester resin is determined as follows. The basic operation conforms to JIS-K0070. The acid value refers to the number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids and the like contained in 1 g of a sample.
(1) Reagent (a) Solvent: N / 10 potassium hydroxide ethyl alcohol solution using phenolphthalein as an indicator immediately before use of ethyl ether-ethyl alcohol mixture (1 + 1 or 2 + 1) or benzene-ethyl alcohol mixture (1 + 1 or 2 + 1) Neutralize with.
(B) Phenolphthalein solution: 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 10 potassium hydroxide-ethyl alcohol solution: Dissolve 7.0 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. . The standardization is performed according to JIS K 8006 (basic matters concerning titration during the reagent content test).
(2) Operation Weigh correctly 1 to 20 g of polyester resin (sample), add 100 ml of solvent and a few drops of phenolphthalein solution as an indicator, and shake well until the sample is completely dissolved. In the case of a solid sample, dissolve it by heating on a water bath. After cooling, this is titrated with an N / 10 potassium hydroxide ethyl alcohol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds. (3) Calculation formula The acid value is calculated by the following formula.
A = B × f × 5.661 / S
A: Acid value B: Amount used of N / 10 potassium hydroxide ethyl alcohol solution (ml)
f: Factor of N / 10 potassium hydroxide ethyl alcohol solution S: Sample (g)

<Measurement of organic solvent content>
The content of the organic solvent present in the aqueous dispersion of the polyester resin fine particles is determined as follows.
Using gas chromatography (GC), the organic solvent content is measured by determining the peak area of the organic solvent under the following conditions. The measuring method is that a sodium chloride aqueous solution is added to a sample (an aqueous dispersion of polyester resin fine particles) until a solid content is precipitated, and after constant volume with purified water, the solution is centrifuged, and the supernatant is measured by GC.
[GC conditions]
Measuring device: GC-15A (with capillary) (manufactured by Shimadzu Corporation)
Carrier: He
Split 40ml / min.
Column: DB-WAX 30m x 0.25mmφ
Temperature rise: After holding at 40 ° C. for 3 minutes, the temperature is raised to 250 ° C. at a rate of 15 ° C. per minute. Hold at 250 ° C. for 2 minutes.
Sample volume: 1.0 μl

<Measurement of particle size distribution of fine particles such as polyester resin fine particles>
The particle size distribution of fine particles such as polyester resin fine particles is measured using a laser diffraction / scattering particle size distribution measuring device (LA-920: manufactured by Horiba, Ltd.) according to the operation manual of the device.
Specifically, in the sample introduction part of the measurement apparatus, the measurement sample was adjusted so that the transmittance was within the measurement range (70 to 95%), and the volume distribution was measured.
The 50% particle size based on volume distribution is the particle size (median diameter) corresponding to 50% cumulative, and the 95% particle size based on volume distribution is the particle size corresponding to 95% cumulative from the smallest.
The coefficient of variation was calculated according to the following formula.
(Formula) coefficient of variation [%] = (arithmetic standard deviation / arithmetic mean diameter) x 100

<Measurement of Number Average Particle Size (D1) and Weight Average Particle Size (D4) of Toner Particles>
The number average particle diameter (D1) and weight average particle diameter (D4) of the toner particles are measured by particle size distribution analysis by the Coulter method. A Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter, Inc.) is used as a measuring device, and measurement is performed according to the operation manual of the device. About 1% sodium chloride aqueous solution is prepared using 1st grade sodium chloride as electrolyte solution. For example, ISOTON-II (manufactured by Coulter Scientific Japan) can be used. As a specific measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant in 100 to 150 ml of the electrolytic aqueous solution, and a measurement sample (toner particles) is added in 2 to 2 ml. Add 20 mg. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. The obtained dispersion treatment liquid is measured by the measurement apparatus equipped with a 100 μm aperture as an aperture, and the volume and number of toner particles are measured for each channel to calculate the volume distribution and number distribution of toner. Then, the number average particle diameter (D1) obtained from the toner number distribution and the weight-based toner weight average particle diameter (D4) obtained from the toner volume distribution (the median value of each channel is a representative value for each channel). Ask).
The channels include: 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm Use 13 channels from 32.00 to 40.30 μm.

Hereinafter, although the present invention is explained still in detail using an example and a comparative example, the mode of the present invention is not limited to these.

(Example 1)
Polyester resin A ((composition (molar ratio) / polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: polyoxyethylene (2.0) -2,2-bis (4- Hydroxyphenyl) propane: terephthalic acid: fumaric acid: trimellitic acid = 30: 20: 26: 20: 4), acid value of 11, weight average molecular weight (Mw) of 11,000, molecular weight of 500 to less than 2,000 The components are 8.5%, Tg is 56 ° C.) and pulverized using a Linrex mill (manufactured by Hosokawa Micron Corporation) so that the maximum particle size is 1.0 μm or less, and the 50% particle size based on volume distribution is 18 μm. A resin pulverized product was obtained. 100 parts by mass of this resin pulverized product was mixed with 900 parts by mass of ion-exchanged water to which 3 parts by mass of a nonionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neugen EA-167) was added. After adding 3 parts by mass of 5N aqueous potassium hydroxide solution to the obtained mixture, the mixture was heated to 155 ° C. immediately before the treatment unit using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) It introduce | transduced into the process part (generator) and emulsified at 200 Mpa, and obtained the aqueous dispersion 1 of the polyester resin microparticles | fine-particles.
The aqueous dispersion 1 of the obtained polyester resin fine particles has a 50% particle size based on volume distribution of 0.26 μm and a coefficient of variation of 16.7%, and has a boiling point of 200 ° C. or lower and a boiling point of 100 existing in the aqueous dispersion. The amount of organic solvent below ℃ was less than the detection lower limit of 10 μg / g. Further, the THF soluble content of the polyester resin fine particles solid obtained by air-drying the aqueous dispersion 1 of the polyester resin fine particles at 30 ° C. was measured by GPC. As a result, the molecular weight (Mp) at the peak top of the main peak was 8,000, the weight average molecular weight (Mw) was 8,600, and the proportion of components having a molecular weight of 500 to 2000 was 10.1%.
The obtained polyester resin fine particle aqueous dispersion 1 was stored at room temperature (25 ° C.) for 30 days, but no sedimentation or separation occurred. Moreover, although it was left to stand at 40 degreeC for 24 hours, there was no change similarly. The obtained results are shown in Table 1. In Tables 1 and 2 below, the storage stability evaluation criteria are as follows. In the case of “storage at room temperature (25 ° C.) for 30 days” or “standing for 24 hours at 40 ° C.”, “○” indicates that no sedimentation or separation occurs, and “△” indicates that some sedimentation or separation occurs. ”, The case where sedimentation or separation occurred clearly was marked“ x ”.

(Example 2)
Nonionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neugen EA-167) 3 parts by mass Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Prisurf AL) 5 parts by mass, 5N potassium hydroxide An aqueous dispersion 2 of polyester resin fine particles was obtained in the same manner as in Example 1 except that the amount of addition was changed to 27 parts by mass. The aqueous dispersion 2 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

(Example 3)
Polyester resin A is converted to polyester resin B ((composition (molar ratio) / polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: ethylene glycol: terephthalic acid: maleic acid: trimellitic acid = 35: 15: 33: 15: 2), acid value is 13,
The weight average molecular weight (Mw) was changed to 16,500, the component having a molecular weight of 500 or more and less than 2,000 was 7.1%, and the Tg was 67 ° C.) (50% particle size based on volume distribution was 19 μm) An aqueous dispersion 3 of polyester resin fine particles was obtained in the same manner as in Example 1 except that the amount of 5N potassium hydroxide aqueous solution added was changed to 12 parts by mass. The aqueous dispersion 3 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

Example 4
An aqueous dispersion 4 of polyester resin fine particles was obtained in the same manner as in Example 3 except that 12 parts by mass of 5N potassium hydroxide aqueous solution was changed to 2 parts by mass of N, N-dimethylaminoethanol. The aqueous dispersion 4 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the obtained results are shown in Table 1.

(Example 5)
The polyester resin A 100 parts by mass, ion-exchanged water 895 parts by mass and an anionic interface are placed in a hermetically pressurized (350 ml) container equipped with a high-speed shearing emulsifier CLEARMIX (M Technique Co., Ltd .: CLM-2.2S). 5 parts by mass of an activator (Daiichi Kogyo Seiyaku Co., Ltd .: Prisurf AL) was added and mixed. While the mixture in the vessel was heated to 130 ° C., the rotor rotation speed was 18,000 r / min and shear dispersed for 30 minutes. Thereafter, cooling was performed, and when the temperature became 100 ° C. or lower, 7 parts by mass of 5N potassium hydroxide aqueous solution was added, and then cooled to room temperature. Aqueous dispersion of polyester resin fine particles having a 50% particle size of 3.4 μm based on volume distribution. Got the body. This aqueous dispersion of polyester resin fine particles was introduced into the treatment section (generator) by heating the aqueous dispersion to 155 ° C. immediately before the treatment section using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.). The emulsion 5 was emulsified at 200 MPa to obtain an aqueous dispersion 5 of polyester resin fine particles. The aqueous dispersion 5 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

(Example 6)
In the same manner as in Example 5, an aqueous dispersion of polyester resin fine particles having a 50% particle size of 3.4 μm based on volume distribution was obtained. After adding 0.6 part by mass of 6N aqueous sodium hydroxide to the aqueous dispersion of polyester resin fine particles, the aqueous dispersion is used immediately before the treatment part using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.). Was heated to 155 ° C., introduced into a treatment section (generator), and emulsified at 200 MPa to obtain an aqueous dispersion 6 of polyester resin fine particles. The aqueous dispersion 6 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

(Example 7)
Changing 27 parts by mass of 5N aqueous potassium hydroxide solution to 2 parts by mass of N, N-dimethylaminoethanol, and changing the heating temperature of the mixture immediately before the treatment part of the treatment using the high-pressure impact disperser Nanomizer to 130 ° C Except that, an aqueous dispersion 7 of polyester resin fine particles was obtained in the same manner as in Example 2. The aqueous dispersion 7 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

(Example 8)
An aqueous dispersion 8 of polyester resin fine particles was obtained in the same manner as in Example 7 except that N, N-dimethylaminoethanol was changed to 0.6 parts by mass. The aqueous dispersion 8 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

Example 9
Except for changing the anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Prisurf AL) to 10 parts by mass and changing 27 parts by mass of 5N aqueous potassium hydroxide to 1.5 parts by mass of sodium carbonate, In the same manner as in Example 2, an aqueous dispersion 9 of polyester fine particles was obtained. The aqueous dispersion 9 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 1.

(Comparative Example 1)
100 parts by mass of the polyester resin A and 300 parts by mass of tetrahydrofuran were dissolved in a 1 L reactor having a stirrer, a temperature controller, and a dropping funnel, and then 4 parts by mass of a 25% aqueous ammonia solution was added. While stirring at room temperature, 300 parts by mass of ion-exchanged water was added dropwise from the dropping funnel to the dissolved and neutralized resin solution at a rate of 10 g / min. After completion of the dropwise addition, the mixture was heated to 50 ° C., 400 parts by mass of tetrahydrofuran and water were distilled off from the reaction system under reduced pressure, and ion-exchanged water was further added to obtain a solid content concentration of 10%. Got. The aqueous dispersion 11 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 2.

(Comparative Example 2)
In a 1 L reactor having a stirrer and a temperature controller, 100 parts by mass of the polyester resin B, 100 parts by mass of acetone, 100 parts by mass of methyl ethyl ketone, 50 parts by mass of isopropyl alcohol, 50 parts by mass of ethylene glycol, and 300 parts by mass of ion-exchanged water are added. The mixture was heated to 80 ° C., stirred for 5 hours, and further heated under reduced pressure to distill 400 parts by mass of acetone, methyl ethyl ketone, isopropyl alcohol, ethylene glycol and water in total. Further, ion-exchanged water was added to obtain an aqueous dispersion 12 of polyester resin fine particles with a solid content concentration of 10%. The aqueous dispersion 12 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 2.

(Comparative Example 3)
Polyester resin A 100 parts by mass, ion-exchanged water 870 parts by mass and anionic surface activity in a tightly pressurizable (350 ml) container equipped with a high-speed shearing emulsifier CLEARMIX (M Technique Co., Ltd .: CLM-2.2S) 30 parts by mass of an agent (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) was added and mixed. While the mixture in the vessel was heated to 160 ° C., the rotor rotation speed was 18,000 r / min and shear dispersed for 30 minutes. Then, it cooled to 30 degreeC and obtained the aqueous dispersion 13 of the polyester resin microparticles | fine-particles. The aqueous dispersion 13 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the obtained results are shown in Table 2.

(Comparative Example 4)
Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Prisurf AL) changed to 30 parts by mass, 5N aqueous potassium hydroxide solution changed to 30 parts by mass, treatment using high pressure impact disperser Nanomizer An aqueous dispersion 14 of polyester resin fine particles was obtained in the same manner as in Example 2 except that the heating temperature of the mixture immediately before the treatment part was changed to 175 ° C. The aqueous dispersion 14 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the obtained results are shown in Table 2.

(Comparative Example 5)
In the same manner as in Example 5, an aqueous dispersion of polyester resin fine particles having a 50% particle size of 3.4 μm based on volume distribution was obtained. After adding 36 parts by mass of 5N aqueous potassium hydroxide to the aqueous dispersion of the polyester resin fine particles, a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) was used, and the aqueous dispersion was added 155 immediately before the treatment part. The mixture was heated to 0 ° C., introduced into a processing section (generator), and emulsified at 200 MPa to obtain an aqueous dispersion 15 of polyester fine particles. The aqueous dispersion 15 of the polyester resin fine particles was measured and evaluated in the same manner as in Example 1, and the results obtained are shown in Table 2.

Next, an aggregation step of mixing at least the aqueous dispersion of the polyester resin fine particles and the colorant to aggregate the resin fine particles and the colorant in an aqueous medium to form an aggregate, and a step of heating and aggregating the aggregate A toner obtained by a production method including the following will be described.
(Toner Production Example 1)
<Preparation of release agent particle dispersion>
-Ester wax (melting point 65 ° C) 10 parts by mass-Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK)
-Ion-exchanged water 88 parts by mass The above was heated to 95 ° C and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50), and then dispersed with a pressure discharge type homogenizer. This release agent particle dispersion was measured using the laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.). As a result, the 50% particle size based on the volume distribution of the contained release agent particles was 0.2 μm, and coarse particles exceeding 1 μm were not observed.

<Preparation of colorant particle dispersion>
-Phthalocyanine pigment (PB-15: 3) 10 parts by mass-Anionic surfactant 2 parts by weight

(Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK)
-Ion exchange water 88 mass parts The above was mixed and disperse | distributed using the sand grinder mill. The colorant particle dispersion was measured using the laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.). As a result, the 50% particle size on the basis of volume distribution of the contained colorant particles was 0.2 μm, and coarse particles exceeding 1 μm were not observed.

<Preparation of charge control particle dispersion>
・ Metal compound of dialkyl-salicylic acid 20 parts by mass (charge control agent, Bontron E-84, manufactured by Orient Chemical Industries)
・ Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK)
-Ion exchange water 78 mass parts The above was mixed and it disperse | distributed using the sand grinder mill. The charge control particle dispersion was measured using the laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.). As a result, the 50% particle size based on the volume distribution of the charge control particles contained was 0.2 μm, and coarse particles exceeding 1 μm were not observed.

<Preparation of liquid mixture>
-Polyester resin fine particle aqueous dispersion 1 250 parts by weight-Colorant particle dispersion 50 parts by weight-Release agent particle dispersion 70 parts by weight 1 liter equipped with a stirrer, cooling tube and thermometer It put into the separable flask and stirred.

<Aggregated particle forming step>
As a flocculant, 70 parts by mass of a 10% sodium chloride aqueous solution was added dropwise to this mixed solution, and the mixture was heated to 57 ° C. while stirring the inside of the flask in a heating oil bath. At this temperature, 3 parts by mass of the polyester resin fine particle aqueous dispersion 1 and 10 parts by mass of the charge control agent particle dispersion were added. Then, after maintaining at 57 ° C. for 1 hour, the volume average particle diameter of the formed aggregated particles was measured using a flow type particle image analyzer (manufactured by Sysmex Corporation: FPIA-3000) according to the operation manual of the apparatus. . As a result, it was confirmed that aggregated particles 1 having a volume average particle diameter of about 4.9 μm were formed.

<Heating and fusion process>
Then, after adding 3 mass parts of surfactant made from an anion (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) here, it heated to 75 degreeC, continuing stirring, and hold | maintained for 3 hours. Then, after cooling, the reaction product was filtered, washed thoroughly with ion exchange water, and then dried to obtain toner particles 1.
When the toner particles 1 were measured by the above Coulter Multisizer II (manufactured by Coulter Inc.), the weight average particle diameter D4 was 5.1 μm, and the number average particle diameter D1 was 4.2 μm. That is, D4 / D1 is 1.21, and the toner particle 1 shows a sharp particle size distribution.
Next, this toner particle 1 was mixed with 1.5% by mass of hydrophobic silica fine powder (primary average particle size 0.01 μm) having a BET specific surface area of 200 m ² / g to prepare the toner 1 of the present invention.

(Toner Production Examples 2 to 9)
Toners 2 to 9 were prepared in the same manner as in Toner Production Example 1 except that the aqueous dispersion 1 of polyester resin fine particles was changed to aqueous dispersions 2 to 9 of polyester resin fine particles in the mixed liquid preparation step. .

(Comparative toner production examples 1 to 5)
Comparative toners 11 to 15 were prepared in the same manner as in the toner production example 1 except that the aqueous dispersion 1 of the polyester resin fine particles was changed to the aqueous dispersions 11 to 15 of the polyester resin fine particles in the mixed liquid preparation step. Prepared.

  Tables 1 and 2 show the particle diameters of the toners 1 to 9 and the comparative toners 11 to 15 and the evaluation of these toners.

<Examples 10 to 18 and Comparative Examples 6 to 10>
The following evaluations were performed using the toners 1 to 9 and the comparative toners 11 to 15. The results are shown in Tables 1 and 2.

(Evaluation of blocking)
Each of the toners was allowed to stand for 24 hours in a thermostatic chamber adjusted to 50 ° C., and the degree of blocking was evaluated.
○: Blocking does not occur Δ: Blocking occurs, but disperses easily when force is applied.
X: Blocking occurs and does not disperse even when force is applied.

(Evaluation of fixing offset)
Evaluation was performed in an environment of normal temperature and humidity using an apparatus in which the process speed of a contact developing type LBP-2510 (manufactured by Canon Inc.) was modified to 150 mm / sec. The set temperature (fixing temperature) of the fixing device of the apparatus is increased from 130 ° C. to 230 ° C. by 5 ° C., and the toner amount per unit area is 0.6 mg / cm on 75 g / m ² paper of A4 at each fixing temperature. ^A solid image was formed to be ² . The formed solid image was observed to examine the temperature at which the high temperature offset phenomenon occurs (high temperature offset temperature). The presence or absence of the high temperature offset phenomenon was judged by visually observing stains on the image and the back of the paper.
○: 220 ° C. or higher ・ Δ: 210 ° C. or higher and lower than 220 ° C. Δ: 200 ° C. or higher and lower than 210 ° C. ×: Less than 210 ° C.

Claims (5)

An aqueous dispersion of polyester resin fine particles,
In the aqueous dispersion of the polyester resin fine particles, the content of the organic solvent having a boiling point of 100 ° C. or less is 100 μg / g or less,
In the molecular weight distribution measured by gel permeation chromatography (GPC) of the polyester resin fine particles in tetrahydrofuran (THF), the peak top of the main peak exists in the molecular weight range of 3,500 to 15,000, The weight average molecular weight is 5,000 or more and 50,000 or less, and the component having a molecular weight of 500 or more and less than 2,000 is contained 0.1% or more and 20.0% or less of the total component amount,
An aqueous dispersion of polyester resin fine particles, wherein the polyester resin fine particles have a volume distribution standard 50% particle size of 0.02 μm or more and 1.00 μm or less.   2. The polyester resin fine particle aqueous dispersion according to claim 1, wherein a 50% particle size of the polyester resin fine particle based on a volume distribution is 0.02 μm or more and 0.40 μm or less. The aqueous dispersion of polyester resin fine particles according to claim 1 or 2, wherein the content of the organic solvent having a boiling point of 200 ° C or less in the aqueous dispersion of the polyester resin fine particles is 100 µg / g or less.   In the molecular weight distribution measured by gel permeation chromatography (GPC) of the polyester resin fine particles in tetrahydrofuran (THF), the component having a molecular weight of 500 or more and less than 2,000 is 0.1% or more and 15. The aqueous dispersion of polyester resin fine particles according to any one of claims 1 to 3, wherein the content is 0% or less. An aggregating step of mixing an aqueous dispersion of polyester resin fine particles and a colorant, aggregating the polyester resin fine particles and the colorant in an aqueous medium to form an aggregate, and a step of heating and aggregating the aggregate. A toner obtained by a production method comprising:
The toner according to claim 1, wherein the aqueous dispersion of polyester resin fine particles is the aqueous dispersion of polyester resin fine particles according to claim 1.