Manufacturing method of toner particle dispersion liquid for electrostatic charge image development

Abstract

To reduce the content of coarse particles in a toner obtained in manufacturing of the toner by agglomeration and fusion means in a highly-productive manufacturing method of an electrostatic charge image developing toner.SOLUTION: In a flow-type fusion process of a manufacturing method of a toner particle dispersion liquid for electrostatic charge image development, an aqueous dispersion liquid A of agglomerated particles containing an amorphous resin A and an aqueous medium B are respectively introduced into different flow channels, are circulated together, and are continuously mixed at a confluence part, so that a dispersion liquid is obtained. The agglomerated particles in the dispersion liquid are fused at a glass transition temperature or more of the amorphous resin A at the confluence part and / or in a flow channel after the confluence, so that a dispersion liquid containing fused particles is obtained.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for producing a toner particle dispersion for electrostatic charge image development.

Background Art

[0002] In the field of electrophotography, with the development of electrophotographic systems, there is a demand for the development of electrophotographic toners that can cope with higher image quality and higher speed. In order to meet the requirement of higher image quality, as a method for obtaining toner with a narrow particle size distribution and small particle size, toner is produced by an aggregation and fusion method (emulsion aggregation method, aggregation unification method) in which fine resin particles or the like are aggregated and fused in an aqueous medium. For example, Patent Document 1 discloses a continuous process for unifying toner particles, which includes: heating an aggregated polyester particle slurry to a first temperature exceeding its glass transition temperature in a first heat exchanger to form a unified particle slurry; after a residence time, rapidly cooling the unified particle slurry to a second temperature below the glass transition temperature; and recovering the rapidly cooled unified particle slurry at the outlet. The roundness of the particles in the aggregated particle slurry is about 0.900 to about 0.940, and the roundness of the particles in the unified particle slurry increases to a value of about 0.940 to about 0.999.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method described in Patent Document 1, as the solid content concentration of the polyester particle slurry increases, the content of coarse particles (coarse toner particles) in the obtained toner may increase. The present invention relates to a method for producing a toner particle dispersion by an aggregation and fusion method, which can reduce the content of coarse particles (coarse particles in the toner particle dispersion) in the obtained toner particle dispersion and has high productivity for producing an electrostatic charge image developing toner particle dispersion.

Means for Solving the Problems

[0005] The inventors of the present invention, in a method for producing an electrostatic charge image developing toner particle dispersion having an aggregation and fusion step, continuously mix the aggregated particles obtained by the aggregation step with an aqueous medium, and heat the aggregated particles at a specific temperature or higher in a confluence part and / or in the flow path after confluence to fuse them, and perform a flow type fusion step. By doing so, it has been found that the content of coarse particles in the obtained resin particle dispersion can be reduced and a toner particle dispersion can be obtained with high productivity.

[0006] That is, the present invention relates to the following [1]. [1] An aqueous dispersion A of aggregated particles containing an amorphous resin A and an aqueous medium B are introduced into different flow paths, respectively, and both are circulated, and the aqueous dispersion A and the aqueous medium B are continuously mixed at the confluence part to obtain a dispersion, and in the confluence part and / or in the flow path after confluence, the aggregated particles in the dispersion are fused at a temperature equal to or higher than the glass transition temperature of the amorphous resin A to obtain a dispersion containing fused particles, a method for producing an electrostatic charge image developing toner particle dispersion having a flow type fusion step.

Effects of the Invention

[0007] According to the present invention, in the production of a toner particle dispersion by an aggregation and fusion method, a method for producing an electrostatic charge image developing toner particle dispersion that can reduce the content of coarse particles in the obtained toner particle dispersion and has high productivity is provided.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

DETAILED DESCRIPTION OF THE INVENTION

[0009] [Method for Producing Electrostatic Charge Image Developing Toner Particle Dispersion] In the method for producing an electrostatic charge image developing toner particle dispersion of the present invention, an aqueous dispersion A of aggregated particles containing an amorphous resin A and an aqueous medium B are introduced into different flow paths, respectively, and caused to flow together. At the confluence part, the aqueous dispersion A and the aqueous medium B are continuously mixed to obtain a dispersion. In the confluence part or in the flow path after confluence, the aggregated particles in the dispersion are fused at a temperature equal to or higher than the glass transition temperature of the amorphous resin A to obtain fused particles, and the method has a flow-type fusing step. Hereinafter, the method for producing an electrostatic charge image developing toner particle dispersion of the present invention may also be simply referred to as "the production method of the present invention". Further, the electrostatic charge image developing toner particle dispersion obtained by the production method of the present invention may also be simply referred to as "toner particle dispersion". Further, the electrostatic charge image developing toner particles obtained from the electrostatic charge image developing toner particle dispersion obtained by the production method of the present invention may also be simply referred to as "toner particles". Further, "electrostatic charge image developing toner" may also be simply referred to as "toner".

[0010] The outline of one embodiment of the production method of the present invention will be described with reference to FIG. 1 (an explanatory diagram showing an outline of one embodiment of the apparatus 100 used in the production method of the present invention). It should be noted that the present invention is not limited to the form shown in the drawings in any way other than the matters defined in the present invention. In one embodiment of the manufacturing method of the present invention, in the flow-type fusion step, an aqueous dispersion A containing aggregated particles of amorphous resin A is introduced into the aqueous dispersion A supply channel 1 from the aqueous dispersion A supply tank 10 and circulated, and an aqueous medium B is introduced into the aqueous medium B supply channel 2 from the aqueous medium B supply tank 20 and circulated. Then, the aqueous dispersion A and the aqueous medium B are joined at the junction J1, and while the obtained dispersion is circulated through the channel 3 downstream from the junction J1, the aggregated particles are heated and fused at a temperature equal to or higher than the glass transition temperature of the amorphous resin A. The heating is performed from the time of joining (starting mixing) of the aqueous dispersion A and the aqueous medium B or after the joining time. The dispersion obtained at the junction J1 can be circulated through the stirring unit M1 in order to increase the mixing efficiency as it circulates through the channel 3. The dispersion that has passed through the stirring unit M1 can be circulated through the channels 4 and the heat exchanger H1 in order to suppress a decrease in the temperature of the dispersion or to heat the dispersion. Further, the dispersion that has passed through the heat exchanger H1 is circulated through the channels 5 and the heat exchanger C1 for cooling and then circulated through the channel 6 and recovered in the recovery tank 30. Although not shown in FIG. 1, instruments necessary for the batch-type aggregation step and the flow-type fusion step described later, such as heat exchangers other than the heat exchanger H1 and liquid feed pumps such as rotary pumps, can be appropriately installed. Further, according to the manufacturing method of the present invention, a toner particle dispersion can also be obtained without using the channels 4 to 6, the stirring unit M1, and the heat exchangers H1 and C1.

[0011] In this specification, "upstream" and "downstream" are used with respect to the direction in which the liquid flows. The side where the liquid is introduced (in FIG. 1, the side of the aqueous dispersion A supply tank 10 and the aqueous medium B supply tank 20) is the upstream, and the side where the liquid is recovered (in FIG. 1, the side of the recovery tank 30) is the downstream.

[0012] According to the manufacturing method of the present invention, the content of coarse particles in the obtained toner particle dispersion can be reduced, and a toner particle dispersion can be obtained with high productivity. The reason for obtaining the above effects is not clear, but it is considered as follows. In the production method of the present invention, an aqueous dispersion A of aggregated particles containing an amorphous resin A and an aqueous medium B are introduced into different flow paths, respectively, and the aqueous dispersion A and the aqueous medium B are circulated in each flow path (circulated together), and the aqueous dispersion A and the aqueous medium B are made to merge at the merging portion. Then, from the time of merging (starting mixing) of the aqueous dispersion A and the aqueous medium B or after the time of merging, heating is performed at a temperature equal to or higher than the glass transition temperature of the amorphous resin A to fuse the aggregated particles. By merging the aqueous dispersion A and the aqueous medium B and the fusion step being a flow type, the collision frequency between the aggregated particles under heating can be reduced, and the aggregated particles can be fused. Therefore, the generation of coarse fused particles can be suppressed, and the content of coarse particles in the obtained toner particle dispersion can be reduced. Further, in the flow type fusion step of the production method of the present invention, since the aqueous dispersion A and the aqueous medium B are merged, even when using an aqueous dispersion A with a relatively high solid content concentration, the generation of coarse fused particles can be suppressed. Therefore, the productivity of the toner particle dispersion can be improved. Note that the above mechanism regarding the effects of the present invention is an estimation and is not limited thereto.

[0013] The definitions of various terms in this specification are shown below. Regarding the hydrocarbon group, the description with parentheses "(iso or tertiary)" and "(iso)" means both the case where these prefixes are present and the case where they are not present. When these prefixes are not present, it indicates normal. "(Meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid, and "(meth)acrylate" means at least one selected from acrylate and methacrylate. Whether the resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum peak temperature of endotherm in the measurement method described in the examples below (softening point (°C) / maximum peak temperature of endotherm (°C)). A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one with a crystallinity index less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted according to the type and ratio of the raw material monomers, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. The carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to produce acids, and alkyl esters of each carboxylic acid (alkyl group having 1 to 3 carbon atoms). "Volume median diameter D 50 " means the particle diameter at which the cumulative volume frequency calculated by volume fraction reaches 50% when calculated from the smaller particle diameters. The coefficient of variation of the particle size distribution (hereinafter also simply referred to as "CV value") is a value represented by the following formula. The volume average particle diameter in the following formula is the particle diameter measured on a volume basis, multiplied by the ratio of the particles having that particle diameter value, and then divided by the number of particles to obtain the particle diameter. CV value (%) = [standard deviation of particle size distribution (μm) / volume average particle diameter (μm)] × 100

[0014] <aqueous dispersion A> Aqueous dispersion A contains aggregated particles containing amorphous resin A. The aggregated particles used in the "aqueous dispersion A of aggregated particles containing amorphous resin A" used in the production method of the present invention are preferably prepared by a batch-type aggregation process. The batch-type aggregation process is preferably carried out in the aqueous dispersion A supply tank 10 shown in Figure 1. The aggregated particles obtained in the batch-type aggregation process include aggregated particles 1 obtained by aggregating resin particles X in the aqueous medium A, or aggregated particles 2 obtained by attaching and aggregating shell resin particles containing an amorphous resin to this core in the aqueous medium A using aggregated particles 1 as the core. In this specification, when simply described as "aggregated particles", it means aggregated particles 1 or 2.

[0015] In the batch-type aggregation step, in addition to the resin particles X, it is preferable to aggregate the colorant particles and the release agent particles to obtain the aggregated particles 1, and it is more preferable to mix the resin particle dispersion liquid X, the colorant particle dispersion liquid, and the release agent particle dispersion liquid and aggregate these particles to obtain the aggregated particles 1.

[0016] [Resin particles X] The resin particle dispersion liquid X used in the batch-type aggregation step contains the resin particles X. The resin particles X contain the amorphous resin A in the resin particles. From the viewpoint of the low-temperature fixability of the resulting toner, it is preferable that the resin particles X contain the crystalline polyester resin C in the same or different resin particles in addition to the amorphous resin A. That is, it is preferable that the aggregated particles contain the crystalline polyester resin C in addition to the amorphous resin A.

[0017] <<Amorphous resin A>> The amorphous resin A preferably contains the amorphous polyester resin A. Hereinafter, the amorphous polyester resin A may be simply referred to as "resin A".

[0018] (Amorphous polyester resin A) The amorphous polyester resin A is a polycondensate of an alcohol component and a carboxylic acid component. Examples of the alcohol component include aliphatic diols, alkylene oxide adducts of aromatic diols, alicyclic diols, and polyhydric alcohols having a valence of 3 or more. Among these, aliphatic diols are preferable from the viewpoint of reducing the content of coarse particles in the resulting toner particle dispersion liquid.

[0019] The number of carbon atoms of the aliphatic diol is preferably 2 or more, more preferably 3 or more, and preferably 16 or less, more preferably 12 or less, and still more preferably 8 or less. Examples of the aliphatic diol include α,ω-aliphatic diols such as 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, and aliphatic diols other than α,ω-aliphatic diols such as 1,2-propanediol and neopentyl glycol. Among these, neopentyl glycol is preferred.

[0020] The amount of the aliphatic diol is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, and 100 mol% or less, preferably 100 mol% in the alcohol component.

[0021] The amount of neopentyl glycol in the alcohol component is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, still more preferably 90 mol% or more, and 100 mol% or less, preferably 100 mol% from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion.

[0022] The alkylene oxide adduct of the aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably the formula (I):

[0023] [Chemical formula] (In the formula, OR 1 and R 2 O is an oxyalkylene group, R 1 and R 2Each is independently an ethylene group or a propylene group, x and y represent the average number of moles of added alkylene oxide, each is a positive number, and the value of the sum of x and y is 1 or more, preferably 1.5 or more, 16 or less, preferably 8 or less, more preferably 4 or less), and is an alkylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane represented by

[0024] Examples of the alkylene oxide adduct of bisphenol A represented by formula (I) include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. When the alcohol component contains an alkylene oxide adduct of bisphenol A, the content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 1 mol% or more, more preferably 1.5 mol% or more, and 16 mol% or less, and more preferably 4 mol% or less.

[0025] Examples of the alicyclic diol include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and an adduct of hydrogenated bisphenol A with an alkylene oxide having 2 to 4 carbon atoms (average number of moles of addition: 2 to 12).

[0026] Examples of the polyhydric alcohol having a trivalent or higher valence include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. One or more kinds of alcohol components may be used.

[0027] Examples of the carboxylic acid component include dicarboxylic acids and polyvalent carboxylic acids having a trivalent or higher valence.

[0028] Examples of the dicarboxylic acid include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, aromatic dicarboxylic acids are preferred.

[0029] Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred. The amount of the aromatic dicarboxylic acid is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol% or more, still more preferably 80 mol% or more, still more preferably 90 mol% or more in the carboxylic acid component, and is 100 mol% or less, preferably 100 mol%.

[0030] The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 2 or more, more preferably 3 or more, and is preferably 30 or less, more preferably 20 or less. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid. When the carboxylic acid component contains an aliphatic dicarboxylic acid, the amount of the aliphatic dicarboxylic acid is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more in the carboxylic acid component, and is preferably 50 mol% or less, more preferably 45 mol% or less, still more preferably 40 mol% or less.

[0031] Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid.

[0032] The polyvalent carboxylic acid having a valence of 3 or more is preferably a trivalent carboxylic acid, and examples thereof include trimellitic acid or its anhydride. When the carboxylic acid component contains a polyvalent carboxylic acid having a valence of 3 or more, the amount of the polyvalent carboxylic acid having a valence of 3 or more is preferably 3 mol% or more, more preferably 6 mol% or more, still more preferably 9 mol% or more in the carboxylic acid component, and is preferably 25 mol% or less, more preferably 20 mol% or less, still more preferably 15 mol% or less. One or more kinds of carboxylic acid components may be used.

[0033] The equivalent ratio of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0034] (Method for producing amorphous polyester resin A) Resin A is produced by a method of polycondensing an alcohol component and a carboxylic acid component. In this reaction, if necessary, an esterification catalyst such as tin(II) bis(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropylate bistriethanolamineate is used in an amount of 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; an esterification co-catalyst such as gallic acid (the same as 3,4,5-trihydroxybenzoic acid) is used in an amount of 0.001 part by mass or more and 0.5 part by mass or less with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component, and the reaction may be carried out. When using a monomer having an unsaturated bond such as fumaric acid for polycondensation, if necessary, a radical polymerization inhibitor in an amount of preferably 0.001 part by mass or more and 0.5 part by mass or less may be used with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The reaction temperature is preferably 120°C or higher, more preferably 150°C or higher, still more preferably 170°C or higher, and is preferably 250°C or lower, more preferably 240°C or lower. The reaction may be carried out in an inert gas atmosphere.

[0035] (Physical properties of amorphous resin A) The softening point of amorphous resin A is preferably 70 °C or higher, more preferably 85 °C or higher, still more preferably 95 °C or higher, and is preferably 140 °C or lower, more preferably 130 °C or lower, still more preferably 120 °C or lower. The preferred range of the softening point of amorphous polyester resin A is the same as the preferred range of the softening point of amorphous resin A. The glass transition temperature of amorphous resin A is preferably 35 °C or higher, more preferably 40 °C or higher, still more preferably 45 °C or higher, and is preferably 75 °C or lower, more preferably 70 °C or lower, still more preferably 65 °C or lower, preferably from 35 °C to 75 °C, more preferably from 40 °C to 70 °C, still more preferably from 45 °C to 65 °C. The preferred range of the glass transition temperature of amorphous polyester resin A is the same as the preferred range of the glass transition temperature of amorphous resin A.

[0036] The acid value of amorphous resin A is preferably 5 mgKOH / g or higher, more preferably 10 mgKOH / g or higher, still more preferably 15 mgKOH / g or higher, and is preferably 35 mgKOH / g or lower, more preferably 30 mgKOH / g or lower, still more preferably 25 mgKOH / g or lower. The preferred range of the acid value of amorphous polyester resin A is the same as the preferred range of the acid value of amorphous resin A.

[0037] The softening point, glass transition temperature and acid value of amorphous resin A can be appropriately adjusted according to the types and amounts of raw material monomers used, and production conditions such as reaction temperature, reaction time and cooling rate. Also, their values are determined by the method described in the examples. When two or more types of amorphous resin A are used in combination, it is preferable that the softening point, glass transition temperature and acid value obtained as their mixture are respectively within the above ranges. The softening point, glass transition temperature and acid value can be determined by weighted average according to the respective masses when a plurality of amorphous resins A are used.

[0038] The content of the amorphous resin A in the resin particles X is preferably 60% by mass or more, more preferably 65% by mass or more, still more preferably 70% by mass or more, still more preferably 75% by mass or more, and is 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

[0039] From the viewpoint of low-temperature fixability, the content of the amorphous polyester resin A in the amorphous resin A is preferably 80% by mass or more, more preferably 85% by mass or more, still more preferably 90% by mass or more, and is 100% by mass or less, preferably 100% by mass.

[0040] The content of the amorphous resin A in the toner particles is preferably 55% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and is preferably 85% by mass or less, more preferably 80% by mass or less, still more preferably 75% by mass or less.

[0041] ≪Crystalline polyester resin C≫ The crystalline polyester resin C is, for example, a crystalline polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component. In this specification, the crystalline polyester resin C may also be simply referred to as "resin C". Resin C is a polycondensate of an alcohol component and a carboxylic acid component. As the alcohol component, α,ω-aliphatic diol is preferable. The carbon number of the α,ω-aliphatic diol is preferably 2 or more, and is preferably 16 or less, more preferably 14 or less, still more preferably 12 or less. Examples of the α,ω-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, and 1,14-tetradecanediol, with ethylene glycol being preferred.

[0042] The amount of the α,ω-aliphatic diol is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less, and more preferably 100 mol% in the alcohol component.

[0043] The alcohol component may contain other alcohol components different from the α,ω-aliphatic diol.

[0044] As the carboxylic acid component, aliphatic dicarboxylic acids are preferred, and linear aliphatic dicarboxylic acids are more preferred. The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, still more preferably 10 or more, and preferably 14 or less, more preferably 12 or less. Examples of the aliphatic dicarboxylic acid include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid and dodecanedioic acid are preferred, and sebacic acid is more preferred.

[0045] The amount of the aliphatic dicarboxylic acid is preferably 75 mol% or more, more preferably 80 mol% or more, still more preferably 85 mol% or more, and 100 mol% or less, and preferably 95 mol% or less in the carboxylic acid component.

[0046] From the viewpoint of the low-temperature fixability of the toner, the carboxylic acid component preferably further contains a monocarboxylic acid. From the same viewpoint, the number of carbon atoms of the monocarboxylic acid is preferably 6 or more, more preferably 8 or more, still more preferably 12 or more, and even more preferably 16 or more, and is preferably 24 or less, more preferably 22 or less, and still more preferably 20 or less. As the monocarboxylic acid, an aliphatic monocarboxylic acid is preferable, and examples thereof include caprylic acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and the like. Among these, preferably one or more selected from caprylic acid, lauric acid, stearic acid, and behenic acid, and from the viewpoints of the low-temperature fixability and chargeability of the toner and the reduction of fogging of the obtained image, more preferably stearic acid and behenic acid, and still more preferably stearic acid. One kind or two or more kinds of the carboxylic acid component may be used.

[0047] The amount of the monocarboxylic acid is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more in the carboxylic acid component, and is preferably 35 mol% or less, more preferably 30 mol% or less, still more preferably 20 mol% or less, and even more preferably 15 mol% or less.

[0048] The equivalent ratio of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0049] Examples of the method for producing the crystalline polyester resin C include the same examples as those of the aforementioned amorphous polyester resin A.

[0050] ≪Physical properties of crystalline polyester resin C≫ The softening point of Resin C is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of the storage stability of the toner, and is preferably 150°C or lower, more preferably 120°C or lower, still more preferably 100°C or lower, from the viewpoint of further improving the low-temperature fixability. The melting point of Resin C is preferably 50°C or higher, more preferably 60°C or higher, still more preferably 70°C or higher, from the viewpoint of the storage stability of the toner, and is preferably 100°C or lower, more preferably 90°C or lower, still more preferably 80°C or lower, from the viewpoint of further improving the low-temperature fixability.

[0051] The acid value of Resin C is preferably 3 mgKOH / g or higher, more preferably 5 mgKOH / g or higher, and is preferably 35 mgKOH / g or lower, more preferably 25 mgKOH / g or lower, still more preferably 20 mgKOH / g or lower, still more preferably 15 mgKOH / g or lower. The softening point, melting point, and acid value of Resin C can be appropriately adjusted by the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and are determined by the methods described in the examples below. When two or more types of Resin C are used in combination, it is preferable that the values of the softening point, melting point, and acid value obtained as a mixture thereof are within the respective ranges.

[0052] When the resin particles X contain crystalline polyester C (Resin C), the mass ratio of the amorphous resin A to Resin C in the resin particles X [amorphous resin A / Resin C] is preferably 60 / 40 or higher, more preferably 65 / 35 or higher, still more preferably 70 / 30 or higher, and is preferably 95 / 5 or lower, more preferably 90 / 10 or lower, still more preferably 85 / 15 or lower.

[0053] When the resin particles X contain Resin C, the content of Resin C in the resin particles X is preferably 5% by mass or higher, more preferably 10% by mass or higher, still more preferably 15% by mass or higher, and is preferably 35% by mass or lower, more preferably 30% by mass or lower, still more preferably 25% by mass or lower.

[0054] When the toner particles contain resin C, the content of resin C in the toner particles is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less.

[0055] The preparation of the resin particle dispersion liquid X containing the amorphous resin A can be carried out using a known method, but it is preferably dispersed by the phase inversion emulsification method. Examples of the phase inversion emulsification method include a method in which an aqueous medium A is added to an organic solvent solution of a resin or a molten resin to cause phase inversion emulsification.

[0056] The volume median particle diameter D of the resin particles X in the dispersion 50 is preferably 0.05 μm or more, more preferably 0.08 μm or more, still more preferably 0.10 μm or more, and preferably 0.8 μm or less, more preferably 0.4 μm or less, still more preferably 0.3 μm or less, from the viewpoint of obtaining a toner particle dispersion liquid capable of obtaining a high-quality image. The CV value of the resin particles X in the dispersion is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less, from the viewpoint of obtaining a toner particle dispersion liquid capable of obtaining a high-quality image. The volume median particle diameter D of the resin particles X 50 and the CV value are determined by the method described in the examples below.

[0057] The solid content concentration of the resin particle dispersion liquid X is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, from the viewpoints of improving the productivity of the toner particle dispersion liquid and improving the dispersion stability of the resin particle dispersion liquid X. Note that the solid content is the total amount of non-volatile components.

[0058] Incidentally, the resin particle dispersion liquid X containing the amorphous resin A and the crystalline polyester resin C can be obtained by the same method as described above. Further, when the resin particle dispersion liquid Xa containing the amorphous resin A and the resin particle dispersion liquid Xb containing the crystalline polyester resin C are mixed and used, these resin particle dispersion liquids can be obtained by the same method as described above.

[0059] 〔Aqueous medium A〕 In the present invention, the "aqueous medium A" is a medium mainly composed of water, and the water content in the aqueous medium A is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and 100% by mass or less. As the water, deionized water or distilled water is preferable. As components other than water that can constitute the aqueous medium together with water, alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; organic solvents soluble in water such as cyclic ethers such as tetrahydrofuran are used. Among these, alkyl alcohols having 1 to 5 carbon atoms are preferable, and methanol or ethanol is more preferable.

[0060] 〔Colorant particles〕 In the batch-type aggregation step, it is preferable to aggregate colorant particles containing a colorant together with the resin particles X. The colorant particles are preferably mixed with the above-described resin particle dispersion liquid X as a colorant particle dispersion liquid in which colorant particles containing a colorant are dispersed in an aqueous medium. As the colorant, all dyes, pigments, etc. used as colorants for toners can be used. Examples of the colorant include carbon black, phthalocyanine blue (e.g., C.I. Pigment Blue 15:3), Permanent Brown FG, Brilliant Fast Scarlet, Pigment Green B, Rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, quinacridone, Carmine 6B, and disazo yellow. The toner may be either a black toner or a color toner other than black. From the perspective of image density, the content of the colorant in the toner particles is preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, and is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less.

[0061] 〔Method for producing colorant particle dispersion〕 The colorant particles are preferably obtained by dispersing a colorant and an aqueous medium A using a disperser such as a homogenizer or an ultrasonic disperser as a colorant particle dispersion. From the perspective of improving the dispersion stability of the colorant, this dispersion is preferably carried out in the presence of a surfactant or an addition polymer (hereinafter, the addition polymer used for dispersing the colorant is also referred to as "addition polymer E").

[0062] Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants.

[0063] The addition polymer E is obtained by addition polymerization of an aromatic group-containing monomer and a hydrophilic monomer. The addition polymer E may contain a structural unit derived from a hydrophobic monomer.

[0064] From the perspective of the image density of the printed matter, the content of the colorant in the colorant particle dispersion is preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 5% by mass or more, and is preferably 35% by mass or less, more preferably 30% by mass or less, still more preferably 25% by mass or less. The solid content concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and is preferably 35% by mass or less, more preferably 25% by mass or less.

[0065] The volume median particle diameter D of the colorant particles 50 From the perspective of improving the dispersibility of the colorant in the toner, it is preferably 0.03 μm or more, more preferably 0.05 μm or more, and is preferably 0.3 μm or less, more preferably 0.2 μm or less, still more preferably 0.15 μm or less. The CV value of the colorant particles is preferably 10% or more, more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, still more preferably 30% or less, from the viewpoint of improving the dispersibility of the colorant in the toner. The volume median particle diameter D of the colorant particles 50 and the CV value are measured by the method of the examples.

[0066] [Release agent particles] In the batch aggregation step, it is preferable to aggregate release agent particles containing a release agent together with the resin particles X and the colorant particles. The release agent particles are preferably mixed with the above-described resin particle dispersion liquid X as a release agent particle dispersion liquid in which release agent particles containing a release agent are dispersed in the aqueous medium A. Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax; microcrystalline wax, paraffin wax, Fischer-Tropsch wax or their oxides; ester waxes such as carnauba wax, montan wax or their deacidified waxes, fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. These may be used alone or in combination of two or more.

[0067] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and preferably 160°C or lower, more preferably 140°C or lower, still more preferably 120°C or lower, still more preferably 100°C or lower.

[0068] The content of the release agent in the toner particles is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 5% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less.

[0069] [Method for producing release agent particle dispersion liquid] The release agent particle dispersion can be obtained using a surfactant, but it is preferably obtained by mixing a release agent and resin particles X. By preparing release agent particles using the release agent and resin particles X, the release agent particles are stabilized by the resin constituting the resin particles X, and it becomes possible to disperse the release agent in an aqueous medium without using a surfactant. In the release agent particle dispersion, it is considered to have a structure in which a large number of resin particles X adhere to the surface of the release agent particles. The resin constituting the resin particles X for dispersing the release agent is preferably a polyester resin, and the aforementioned amorphous polyester resin A is more preferable. Further, a composite resin D having a polyester resin segment and an addition polymerization resin segment may be used. Regarding the composite resin D, reference is made to JP-A-2021-182045.

[0070] The volume median diameter D of the release agent particles 50 is preferably 0.05 μm or more, more preferably 0.1 μm or more, still more preferably 0.2 μm or more, from the viewpoint of obtaining uniform aggregated particles 1 by aggregation, and is preferably 1 μm or less, more preferably 0.8 μm or less, still more preferably 0.6 μm or less. The CV value of the release agent particles is preferably 10% or more, more preferably 15% or more, and is preferably 45% or less, more preferably 40% or less. The volume median diameter D of the release agent particles 50 and the CV value are measured by the method described in the examples.

[0071] The aggregated particles 1 may further contain additives such as a charge control agent, magnetic powder, fluidity improver, conductivity adjuster, reinforcing fillers such as fibrous substances, antioxidant, anti-aging agent, and cleaning property improver.

[0072] 〔Surfactant〕 In the batch-type aggregation step, it is preferable to aggregate the resin particles X after preparing a mixed dispersion obtained by mixing the resin particle dispersion X and, if necessary, a colorant particle dispersion and a release agent particle dispersion. When preparing the mixed dispersion, from the viewpoint of improving the dispersion stability of resin particles X and optional components such as colorant particles and mold release agent particles that are added as required, it may be carried out in the presence of a surfactant. Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. One kind or two or more kinds of surfactants may be used. When using a surfactant, the amount used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 5 parts by mass or less, more preferably 1 part by mass or less, based on 100 parts by mass of resin particles X, as the total amount of the surfactant.

[0073] The mixing of the aforementioned resin particle dispersion X and optional components is carried out by a conventional method. From the viewpoint of efficiently performing aggregation, it is preferable to add a flocculant to the mixed dispersion obtained by the mixing.

[0074] 〔Flocculant〕 Examples of the flocculant include cationic surfactants of quaternary salts, organic flocculants such as polyethyleneimine; inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and inorganic agents such as divalent or higher metal complexes. From the viewpoint of improving the aggregability and obtaining uniform aggregated particles 1, inorganic flocculants with a valence of 1 or more and 5 or less are preferable, inorganic metal salts and inorganic ammonium salts with a valence of 1 or more and 2 or less are more preferable, and ammonium sulfate is even more preferable.

[0075] Using a flocculant, for example, to a mixed dispersion containing resin particles X, mold release agent particles, and colorant particles at 0°C or higher and 40°C or lower, 5 parts by mass or more and 50 parts by mass or less of the flocculant is added based on 100 parts by mass of the resin particles, and the resin particles, mold release agent particles, and colorant particles are aggregated in an aqueous medium to obtain aggregated particles 1. Further, from the viewpoint of promoting aggregation, it is preferable to raise the temperature of the dispersion after adding the flocculant.

[0076] The volume median diameter D of the aggregated particles 1 obtained in the batch aggregation process 50 is preferably 3 μm or more, more preferably 4 μm or more, still more preferably 5 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less. It is preferable to continue aggregation to obtain the aggregated particles 1 until the desired volume median diameter is reached.

[0077] In the production method of the present invention, in order to obtain toner particles having a core-shell structure, in the batch aggregation process, using the obtained aggregated particles 1 as a core, shell resin particles containing a shell resin B are attached and aggregated to obtain aggregated particles 2 having a core-shell structure. As the shell resin B, an amorphous resin is preferable, an amorphous polyester resin is more preferable, and the above-described resin A is still more preferable. The shell resin particle dispersion (resin particle dispersion Y) is obtained by the production method of the above-described resin particle dispersion X.

[0078] Before adding the resin particle dispersion Y to the dispersion of the aggregated particles 1, an aqueous medium A may be added to the dispersion of the aggregated particles 1 for dilution. Further, when adding the resin particle dispersion Y to the dispersion of the aggregated particles 1, the aggregating agent may be used in order to efficiently attach the shell resin particles to the aggregated particles 1. The temperature at the time of adding the resin particle dispersion Y is preferably 30°C or more, more preferably 35°C or more, still more preferably 40°C or more, and is preferably 80°C or less, more preferably 70°C or less, still more preferably 60°C or less.

[0079] The resin particle dispersion Y may be added continuously over a certain period of time, added all at once, or added in multiple divided portions. However, it is preferable to add it continuously over a certain period of time or add it in multiple divided portions. By adding it as described above, the resin particles for the shell are more likely to selectively adhere to the aggregated particles 1. Among them, from the viewpoints of promoting selective adhesion and improving the productivity of the toner, it is preferable to add it continuously over a certain period of time. The time in the case of continuous addition is preferably 10 minutes or more, more preferably 30 minutes or more, from the viewpoints of obtaining uniform aggregated particles 2 and improving the productivity of the toner, and is preferably 10 hours or less, more preferably 7 hours or less, still more preferably 3 hours or less.

[0080] The mass ratio of the resin particles for the shell to the mass of the aggregated particles 1 [resin particles for the shell / aggregated particles 1] is preferably 1 / 99 or more, more preferably 3 / 97 or more, from the viewpoint of the low-temperature fixability of the toner, and is preferably 20 / 80 or less, more preferably 15 / 85 or less, still more preferably 10 / 90 or less.

[0081] The volume median diameter D of the obtained aggregated particles 2 50 is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, from the viewpoint of productivity, and is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 6.5 μm or less, from the viewpoint of obtaining a toner that can obtain high-quality images. The content of the amorphous resin A in the aggregated particles is preferably 60% by mass or more, more preferably 65% by mass or more, still more preferably 70% by mass or more, from the viewpoint of fixing the colorant, and is preferably 98% by mass or less, more preferably 95% by mass or less, still more preferably 90% by mass or less, from the viewpoints of containing the colorant and the release agent. The preferable range of the content of the amorphous polyester resin A in the aggregated particles is the same as the preferable range of the content of the amorphous resin A.

[0082] The solid content concentration of the aqueous dispersion A to be joined and mixed with the aqueous medium B is preferably 8% by mass or more, more preferably 10% by mass or more, still more preferably 11% by mass or more from the viewpoint of toner productivity, and from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, it is preferably 20% by mass or less, more preferably 18% by mass or less, still more preferably 16% by mass or less. From these viewpoints, it is preferably 8% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 18% by mass or less, still more preferably 11% by mass or more and 16% by mass or less. Also, the content of aggregated particles in the aqueous dispersion A to be joined and mixed with the aqueous medium B is preferably 8% by mass or more, more preferably 10% by mass or more, still more preferably 11% by mass or more from the viewpoint of toner productivity, and from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, it is preferably 20% by mass or less, more preferably 18% by mass or less, still more preferably 16% by mass or less. From these viewpoints, it is preferably 8% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 18% by mass or less, still more preferably 11% by mass or more and 16% by mass or less.

[0083] <Flow-type fusion process> The manufacturing method of the present invention has a flow-type fusion process. In the manufacturing method of the present invention, after the batch-type aggregation process, it is preferable to perform a flow-type fusion process using the aqueous dispersion A obtained by this process. An embodiment of the flow-type fusion process will be described with reference to FIG. 1. In one embodiment of the flow-type fusion process, an aqueous dispersion A containing aggregated particles of amorphous resin A is introduced and circulated from the aqueous dispersion A supply tank 10 through the aqueous dispersion A supply flow path 1.

[0084] The capacity of the aqueous dispersion A supply tank 10 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A, etc., and is preferably 1 L or more, more preferably 10 L or more, still more preferably 100 L or more, and is preferably 20000 L or less, more preferably 1000 L or less, still more preferably 300 L or less. The material of the aqueous dispersion A supply tank is, for example, stainless steel, glass, brass, or titanium.

[0085] The equivalent diameter of the aqueous dispersion A supply channel 1 can be appropriately adjusted according to the concentrations and amounts of the aqueous dispersion A and the aqueous medium B, preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less. The above "equivalent diameter" is also called the equivalent (straight) diameter. The "equivalent diameter" is a term used in the field of mechanical engineering. The "equivalent diameter" is the diameter of the cross-section of the equivalent circular pipe when assuming an equivalent circular pipe for a pipe or flow channel with an arbitrary cross-sectional shape inside the pipe. The equivalent diameter (deq) is defined as deq = 4A / p (A: the cross-sectional area of the pipe inside the pipe, p: the wetted perimeter (inner perimeter) of the pipe). When the equivalent diameter is applied to a circular pipe, it coincides with the diameter of the cross-section of the circular pipe. The equivalent diameter is used to estimate the flow or heat transfer characteristics of the pipe based on the data of the equivalent circular pipe and represents the spatial scale (representative length) of the phenomenon. For an equivalent diameter, in the case of a square pipe with a side a of the inner cross-section of the pipe, deq = 4a 2 / 4a = a, and in the case of an equilateral triangle pipe with a side a, deq = a / 3 1 / 2 In the case of the flow between parallel flat plates with a flow channel height h, deq = 2h (for example, refer to "Dictionary of Mechanical Engineering" edited by the Japan Society of Mechanical Engineers, 1997, Maruzen Co., Ltd.). In addition, when explaining the inner cross-sectional size (equivalent diameter) of a flow channel, a confluence part, a mixer, etc. in this specification, it is the size excluding the connecting parts between flow channels, the connecting parts between a flow channel and a confluence part, and the connecting parts between a flow channel and a mixer. That is, the size of each of the above connecting parts is appropriately adjusted using a connecting tube or the like so that the fluid flows from upstream to downstream through the connecting part.

[0086] The length of the aqueous dispersion A supply channel 1 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 1 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and preferably 100 m or less, more preferably 50 m or less, still more preferably 10 m or less.

[0087] The material of the pipe of the aqueous dispersion A supply channel 1 is, for example, stainless steel, brass, titanium, and an alloy containing at least one of these and other metals, as well as glass, polytetrafluoroethylene (PTFE), and perfluoroalkoxy alkane (PFA).

[0088] The flow rate at which the aqueous dispersion A is introduced from the aqueous dispersion A supply tank 10 into the aqueous dispersion A supply channel 1, that is, the flow rate at which the aqueous dispersion A flows through the aqueous dispersion A supply channel 1, can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 10 mL / min or more, more preferably 30 mL / min or more, still more preferably 50 mL / min or more, and preferably 100 L / min or less, more preferably 50 L / min or less, still more preferably 10 L / min or less.

[0089] In the flow-type fusion process, the aqueous medium B is introduced into the aqueous medium B supply channel 2 from the aqueous medium B supply tank 20 and circulated.

[0090] 〔Aqueous medium B〕 The aqueous medium B has the same meaning as the above-mentioned aqueous medium A. From the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, the aqueous medium B is preferably an aqueous dispersion B containing a dispersant.

[0091] ≪Dispersant≫ As the dispersant, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, polyoxyalkylene alkyl ether sulfates, aryl sulfonates, aryl sulfonic acid formalin condensates, etc. Preferably, it is an alkali metal salt of an aryl sulfonic acid formalin condensate, and more preferably a sodium salt of a β-naphthalene sulfonic acid formalin condensate. These may be used alone or in combination of two or more. From the viewpoint of reliably preventing unnecessary aggregation, the concentration of the dispersant in the aqueous dispersion B is preferably 1% by mass or more, more preferably 2% by mass or more, and from the viewpoint of reducing the residue in the toner, it is preferably 10% by mass or less, more preferably 5% by mass or less.

[0092] The capacity of the aqueous medium B supply tank 20 can be appropriately adjusted according to the concentration and amount of the aqueous medium B, etc. Preferably, it is 3 L or more, more preferably 30 L or more, still more preferably 300 L or more, and preferably 40000 L or less, more preferably 2000 L or less, still more preferably 600 L or less. The material of the aqueous medium B supply tank is, for example, stainless steel, glass, plastic, brass, titanium.

[0093] The equivalent diameter (inner diameter) of the piping of the aqueous medium B supply passage 2 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc. Preferably, it is 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0094] The length of the piping of the aqueous medium B supply passage 2 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc. Preferably, it is 1 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and preferably 100 m or less, more preferably 50 m or less, still more preferably 10 m or less.

[0095] Specific examples of the material of the pipe of the aqueous medium B supply flow path 2 are the same as the specific examples of the material of the aqueous dispersion A supply flow path 1.

[0096] The flow rate at which the aqueous medium B is introduced from the aqueous medium B supply flow path 2, that is, the flow rate at which the aqueous medium B flows through the aqueous medium B supply flow path 2, can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 20 mL / min or more, more preferably 60 mL / min or more, still more preferably 100 mL / min or more, and preferably 200 L / min or less, more preferably 100 L / min or less, still more preferably 20 L / min or less.

[0097] In one embodiment of the flow type fusion process, the aqueous dispersion A flowing through the aqueous dispersion A supply flow path 1 and the aqueous medium B flowing through the aqueous medium B supply flow path 2 are joined at the junction J1. In the embodiment of FIG. 1, a T-shaped connector is used as the junction J1, but a Y-shaped connector may also be used. As will be described later, a static mixer may also be used.

[0098] The equivalent diameter (inner diameter) of the flow path in the junction J1 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc. From the viewpoint of efficiently mixing the aqueous dispersion A and the aqueous medium B, it is preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0099] The material of the junction J1 is, for example, rubber and the material of the pipe of the aqueous dispersion A supply flow path 1 described above.

[0100] In one embodiment of the flow-type fusing process, continuous mixing occurs at the confluence section J1. By causing both the aqueous dispersion A of agglomerated particles containing the amorphous resin A and the aqueous medium B to flow through the flow path, continuous mixing can be achieved. Since the confluence section J1 serves as a mixer, it is possible to cause the mixture to flow downstream of the confluence section J1 while mixing the aqueous dispersion A and the aqueous medium B. Note that "continuous" includes temporary interruptions and intermittent mixing. Then, in one embodiment of the flow-type fusing process, the agglomerated particles in the dispersion obtained by the confluence of the aqueous dispersion A and the aqueous medium B at the confluence section J1 are heated in the confluence section or in the flow path after confluence (downstream of the confluence section) to promote the fusion of the agglomerated particles. Fusion may be carried out both in the confluence section and in the flow path after confluence. The temperature of the agglomerated particles can be adjusted by adjusting the temperature of the dispersion. Fusion can be carried out by heating the agglomerated particles to a temperature equal to or higher than the glass transition temperature by causing the aqueous dispersion A and the aqueous medium B heated to a temperature equal to or higher than the glass transition temperature of the amorphous resin A contained in the agglomerated particles to confluence and mix. Also, when the temperature of the dispersion obtained at the confluence section J1 is lower than the glass transition temperature, fusion can also be carried out by heating the dispersion downstream of the confluence section J1 to heat the agglomerated particles to a temperature equal to or higher than the glass transition temperature. In the production method of the present invention, from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, fusion is preferably carried out by causing the aqueous dispersion A and the aqueous medium B heated to a temperature equal to or higher than the glass transition temperature of the amorphous resin A contained in the agglomerated particles to confluence and mix.

[0101] From the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, the temperature of the aqueous dispersion A that confluences and mixes with the aqueous medium B is preferably lower than the glass transition temperature of the amorphous resin A, more preferably 60°C or lower, still more preferably 55°C or lower, and from the viewpoint of the productivity of the toner particle dispersion, it is preferably 35°C or higher, more preferably 40°C or higher, still more preferably 45°C or higher. Also, from the viewpoint of reducing the content of coarse particles in the resulting toner particle dispersion, the temperature of the aqueous dispersion A that joins and mixes with the aqueous medium B is preferably below the glass transition temperature of the amorphous resin A, more preferably 3°C or more lower than the glass transition temperature of the amorphous resin A, still more preferably 5°C or more lower. From the viewpoint of toner productivity, it is preferably -40°C or more of the glass transition temperature of the amorphous resin A, more preferably -30°C or more of the glass transition temperature of the amorphous resin A, still more preferably -20°C of the glass transition temperature of the amorphous resin A. From these viewpoints, it is preferable that it is -40°C or more and less than the glass transition temperature of the amorphous resin A, more preferably -30°C or more and -3°C or less of the glass transition temperature of the amorphous resin A, still more preferably -20°C or more and -5°C or less of the glass transition temperature of the amorphous resin A.

[0102] The temperature of the aqueous medium B that joins and mixes with the aqueous dispersion A can be appropriately adjusted according to the concentrations and amounts of the aqueous dispersion A and the aqueous medium B, etc. From the viewpoint of reducing the content of coarse particles in the resulting toner particle dispersion, it is preferably at or above the glass transition temperature of the amorphous resin A, more preferably at a temperature 10°C or more higher than the glass transition temperature of the amorphous resin A, still more preferably at a temperature 15°C or more higher, even more preferably at a temperature 20°C or more higher. And from the viewpoint of productivity, it is preferably at a temperature 40°C or less higher than the glass transition temperature of the amorphous resin A, more preferably at a temperature 35°C or less higher, still more preferably at a temperature 30°C or less higher. From these viewpoints, it is preferable that it is at or above the glass transition temperature of the amorphous resin A and at or below the glass transition temperature of the amorphous resin A + 40°C, more preferably at or above the glass transition temperature of the amorphous resin A + 10°C and at or below the glass transition temperature of the amorphous resin A + 35°C, still more preferably at or above the glass transition temperature of the amorphous resin A + 15°C and at or below the glass transition temperature of the amorphous resin A + 30°C.

[0103] The temperature of the dispersion obtained at the confluence part J1 is preferably equal to or higher than the glass transition temperature of the amorphous resin A contained in the aggregated particles, that is, equal to or higher than the temperature at which the fusion of the aggregated particles proceeds. From the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, the temperature of the dispersion obtained at the confluence part J1 is preferably 3°C or more, more preferably 5°C or more, still more preferably 10°C or more higher than the glass transition temperature of the amorphous resin A, and from the viewpoint of productivity, it is preferably 40°C or less, more preferably 30°C or less, still more preferably 20°C or less higher. From these viewpoints, the temperature of the dispersion at the confluence part J1 is preferably equal to or higher than the glass transition temperature of the amorphous resin A contained in the aggregated particles and equal to or lower than the glass transition temperature of the amorphous resin A + 40°C, more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 5°C and equal to or lower than the glass transition temperature of the amorphous resin A + 30°C, still more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 10°C and equal to or lower than the glass transition temperature of the amorphous resin A + 20°C. The preferable temperature range of the dispersion downstream of the confluence part J1 or the preferable temperature range of the dispersion when heating the dispersion in the flow path after confluence to advance the fusion of the aggregated particles is the same as above.

[0104] A heat exchanger (not shown in FIG. 1) can be arranged in the aqueous dispersion A supply flow path 1 and the aqueous medium B supply flow path 2 to adjust the aqueous dispersion A and the aqueous medium B to a desired temperature and circulate them to the confluence part for temperature control.

[0105] The mixing ratio of the aqueous medium B to the aqueous dispersion A at the confluence part J1 (mass of the aqueous medium B / mass of the aqueous dispersion A) is preferably 0.5 / 1 or more, more preferably 1 / 1 or more, still more preferably 1.5 / 1 or more, still more preferably 2 / 1 or more per unit time from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, and from the viewpoint of productivity, it is preferably 10 / 1 or less, more preferably 5 / 1 or less, still more preferably 3 / 1 or less. From these viewpoints, it is preferably 0.5 / 1 or more and 10 / 1 or less, more preferably 1 / 1 or more and 5 / 1 or less, still more preferably 1.5 / 1 or more and 3 / 1 or less, still more preferably 2 / 1 or more and 3 / 1 or less.

[0106] From the viewpoint of reducing the content of coarse particles in the resulting toner particle dispersion, it is preferable to keep the mixed liquid heated to a temperature equal to or higher than the glass transition temperature of the amorphous resin A at a temperature equal to or higher than the glass transition temperature of the amorphous resin A while continuing the mixing until the fused particles reach the desired roundness. From the viewpoint of obtaining a high-quality image, the roundness of the fused particles is preferably 0.955 or more, more preferably 0.960 or more, still more preferably 0.965 or more, and preferably 0.990 or less, more preferably 0.985 or less, still more preferably 0.980 or less. From these viewpoints, it is preferably 0.955 or more and 0.990 or less, more preferably 0.960 or more and 0.985 or less, still more preferably 0.965 or more and 0.980 or less.

[0107] In one embodiment of the flow-type fusing step, from the viewpoint of reducing the content of coarse particles in the resulting toner particle dispersion, the dispersion obtained at the confluence part J1 can be passed through the flow path 3 which is the flow path after confluence and then through the stirring part M1.

[0108] The equivalent diameter (inner diameter) of the piping of the flow path 3 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., and is preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0109] The length of the piping of the flow path 3 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., and is preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 100 cm or less, more preferably 50 cm or less, still more preferably 10 cm or less.

[0110] The material of the piping of the flow path 3 is the same as the specific example of the material of the aqueous dispersion A supply flow path 1.

[0111] The stirring unit M1 has an in-line mixer, and a static mixer is preferred as the in-line mixer. Generally, since a static mixer is not subjected to shear force or is subjected to weak shear force, when the resin is deformed or when the aggregated particles have a core-shell structure (aggregated particles 2), the aggregated particles are prevented from being broken and the resin of the core is prevented from being exposed on the resin surface. Therefore, it is suitable for the production of toner particle dispersions. In addition, since a static mixer can be continuously processed, it is also suitable for industrial production. As the static mixer, a stationary type mixing and stirring device having no moving part is preferred. The stationary type mixing and stirring device refers to a static mixer designed such that the dispersion liquid obtained at the confluence part J1 passes through a resistance member fixed inside the pipe, and the purpose of mixing is achieved by the reversal and conversion of the liquid flow accompanying the progress of the liquid. Although the flow characteristics of the liquid flow, that is, the mixing characteristics, may vary depending on the structure of the resistance member, a member in which a rectangular plate is twisted 180° in the left-right reverse direction is typical.

[0112] Such static mixers are commercially available, and specific examples are shown below. (1) 3 / 4-N60S-331-0, 1 / 2-N60S-331-0, and 1-N30-131-F manufactured by Noritake Company Limited (2) SMX-DN 25×10 and SMX-DN 25×5 manufactured by SULZER CHEMTECH, etc.

[0113] The equivalent diameter of the stirring unit M1 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., for example, it is 2 to 3 cm, and the length is, for example, 20 to 50 cm.

[0114] In one embodiment of the flow-type fusion process, in order to suppress the temperature drop or maintain the temperature of the mixed liquid flowing through the stirring unit M1, the mixed liquid flowing through the stirring unit M1 can be made to flow through the flow path 4 and then through the heat exchanger H1.

[0115] The equivalent diameter (inner diameter) of the pipe of the flow path 4 can be appropriately adjusted according to the concentrations and amounts of the aqueous dispersion A and the aqueous medium B, preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0116] The length of the pipe of the flow path 4 can be appropriately adjusted according to the concentrations and amounts of the aqueous dispersion A and the aqueous medium B, preferably 1 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and preferably 100 m or less, more preferably 50 m or less, still more preferably 10 m or less.

[0117] The material of the flow path 4 is the same as the specific examples of the material of the aqueous dispersion A supply flow path 1.

[0118] Note that the flow path after confluence downstream of the confluence portion J1 can be appropriately heated by, for example, a belt heater to control the temperature of the dispersion. Also, the temperature of the dispersion can be controlled by the heat exchanger H1.

[0119] Since the fused particles obtained in the flow-type fusion step are present in the heated aqueous medium, first, it is preferable to cool the fused particles. That is, the production method of the present invention preferably has a step of cooling the fused particles after the flow-type fusion step.

[0120] The cooling of the fused particles can be performed, for example, by flowing through the flow path 5 from the heat exchanger H1 and then flowing through the heat exchanger (cooler) C1. The temperature of the dispersion containing the cooled fused particles is preferably lower than the glass transition temperature of the amorphous resin A.

[0121] Note that, from the perspective of productivity, it is preferable to circulate the dispersion containing the fused particles through the flow path 5 from the heat exchanger H1 and collect it in the recovery tank 30 without using the flow path 6 and the heat exchanger C1, and then place the recovery tank 30 in an ice bath or the like to cool the fused particles. That is, after fusing the aggregated particles in the flow path, it is preferable to discharge the dispersion containing the obtained fused particles from the flow path, and then cool the dispersion containing the fused particles.

[0122] The equivalent diameter (inner diameter) of the pipe of the flow path 5 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0123] The length of the pipe of the flow path 5 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 1 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and preferably 10 m or less, more preferably 5 m or less, still more preferably 1 m or less.

[0124] The material of the pipe of the flow path 5 is the same as the specific example of the material of the aqueous dispersion A supply flow path 1.

[0125] The equivalent diameter (inner diameter) of the pipe of the flow path 6 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 0.3 cm or more, more preferably 1.5 cm or more, still more preferably 3 cm or more, and preferably 20 cm or less, more preferably 10 cm or less, still more preferably 5 cm or less.

[0126] The length of the pipe of the flow path 6 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 1 cm or more, more preferably 5 cm or more, still more preferably 10 cm or more, and preferably 10 m or less, more preferably 5 m or less, still more preferably 1 m or less.

[0127] The material of the pipe of the flow path 6 is the same as the specific example of the material of the aqueous dispersion A supply flow path 1.

[0128] The capacity of the recovery tank 30 can be appropriately adjusted according to the concentration and amount of the aqueous dispersion A and the aqueous medium B, etc., preferably 3 L or more, more preferably 30 L or more, still more preferably 300 L or more, and preferably 60000 L or less, more preferably 3000 L or less, still more preferably 900 L or less. The material of the recovery tank 30 is, for example, stainless steel, glass, brass, or titanium.

[0129] <Toner particle dispersion for electrostatic charge image development> After the cooling step, from the viewpoint of productivity, the content (concentration) of the solid content in the toner particle dispersion for electrostatic charge image development obtained by the method for producing a toner particle dispersion for electrostatic charge image development of the present invention is preferably 2% by mass or more, more preferably 3% by mass or more, and from the viewpoint of reducing the content of coarse particles in the obtained toner particle dispersion, preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less. In addition, the solid content refers to the total amount of the resin, colorant, and release agent, and excludes surfactants and the like that do not participate in the performance of the toner that is removed in the cleaning step. The preferable range of the content of the toner particles in the toner particle dispersion is the same as the preferable range of the content of the solid content. From the viewpoint of obtaining a fine image, the content of coarse particles in the toner particle dispersion is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 5% by mass or less, and from the viewpoint of productivity, for example, it may be 1% by mass or more. The content of coarse particles can be determined by the method described in the examples.

[0130] The volume median diameter D of the toner particles 50 From the viewpoint of the versatility of the toner, it is preferably 3 μm or more, more preferably 4 μm or more, still more preferably 5 μm or more, and from the viewpoint of obtaining a precise image, it is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less. Incidentally, the volume median diameter D of the toner particles50 It is preferably not larger than the volume median particle diameter of the aggregated particles. That is, in the flow-type fusing step, it is preferable that aggregation and fusion of the aggregated particles do not occur.

[0131] After cooling the toner particle dispersion, it is preferable to perform solid-liquid separation. For the solid-liquid separation, a suction filtration method or the like is preferably used. It is preferable to perform washing after the solid-liquid separation. At this time, since it is preferable to remove the added surfactant and the like, when the surfactant has a cloud point, it is preferable to wash with an aqueous medium at a temperature not higher than the cloud point of the surfactant. It is preferable to perform the washing a plurality of times.

[0132] Next, it is preferable to perform drying. The temperature during drying is preferably such that the temperature of the fused particles themselves is lower than the glass transition temperature of the amorphous resin A, and more preferably 10 °C or lower. As the drying method, it is preferable to use a vacuum low-temperature drying method, a vibration-type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like.

[0133] 〔Toner particles〕 In the production method of the present invention, the particles obtained after drying may be used as toner particles, or the surface of the obtained particles may be treated to obtain toner particles. The volume median particle diameter D of the toner particles 50 is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less, from the viewpoint of improving the productivity and low-temperature fixability of the toner. The CV value of the toner particles is preferably 12% or more, more preferably 14% or more, still more preferably 16% or more, from the viewpoint of improving the productivity of the toner, and preferably 40% or less, more preferably 35% or less, from the viewpoint of obtaining a high-quality image. The volume median particle diameter D of the toner particles 50 , and the CV value are determined by the method described in the examples below. The circularity of the toner particles is preferably 0.955 or more, more preferably 0.960 or more, still more preferably 0.965 or more, and preferably 0.990 or less, more preferably 0.985 or less, still more preferably 0.980 or less, from the viewpoint of obtaining a high-quality image. These toner particles are used as an electrostatic charge developing toner.

[0134] [Electrostatic charge image developing toner] The toner particles can be used as the toner as they are, or those obtained by adding a fluidizing agent or the like as an external additive to the surface of the toner particles may be used as the toner. Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferable. The external additive may be used alone or in combination of two or more. Also, the same kind of external additives having different particle sizes may be used in combination. When performing surface treatment of the toner particles using the external additive, the addition amount of the external additive is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, still more preferably 4 parts by mass or less, based on 100 parts by mass of the toner particles.

[0135] The electrostatic charge image developing toner obtained by the present invention can be used as a one-component developer or as a two-component developer by mixing with a carrier.

[0136] The present invention includes the following aspects. <1> An aqueous dispersion A of aggregated particles containing an amorphous resin A and an aqueous medium B are introduced into different flow paths, respectively, and caused to flow together. At the confluence part, the aqueous dispersion A and the aqueous medium B are continuously mixed to obtain a dispersion. In the confluence part and / or in the flow path after confluence, the aggregated particles in the dispersion are fused at a temperature equal to or higher than the glass transition temperature of the amorphous resin A to obtain a dispersion containing fused particles. A method for producing a toner particle dispersion for electrostatic charge image development having a flow-type fusing step. <2> The method for producing a toner particle dispersion for electrostatic charge image development according to <1>, wherein the glass transition temperature of the amorphous resin A is preferably 35°C or higher and 75°C or lower, more preferably 40°C or higher and 70°C or lower, still more preferably 45°C or higher and 65°C or lower. <3> The method for producing a toner particle dispersion for electrostatic charge image development according to <1> or <2>, wherein the amorphous resin A contains an amorphous polyester resin A. <4> The method for producing a toner particle dispersion for electrostatic charge image development according to <3>, wherein the glass transition temperature of the amorphous polyester resin A is preferably 35°C or higher and 75°C or lower, more preferably 40°C or higher and 70°C or lower, still more preferably 45°C or higher and 65°C or lower. <5> The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <4>, wherein the aggregated particles further contain a crystalline polyester resin C. <6> The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <5>, which has a step of cooling after discharging the dispersion containing the fused particles obtained in the flow-type fusing step from the flow path. <7> The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <6>, wherein the solid content concentration of the aqueous dispersion A that is confluent with and mixed with the aqueous medium B is preferably 8% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 18% by mass or less, still more preferably 11% by mass or more and 16% by mass or less. <8> The content of the aggregated particles in the aqueous dispersion A that joins and mixes with the aqueous medium B is preferably 8% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 18% by mass or less, still more preferably 11% by mass or more and 16% by mass or less. The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <7>. <9> The temperature of the aqueous dispersion A that joins and mixes with the aqueous medium B is preferably equal to or higher than the glass transition temperature of the amorphous resin A - 40°C and lower than the glass transition temperature of the amorphous resin A, more preferably equal to or higher than the glass transition temperature of the amorphous resin A - 30°C and equal to or lower than the glass transition temperature of the amorphous resin A - 3°C, still more preferably equal to or higher than the glass transition temperature of the amorphous resin A - 20°C and equal to or lower than the glass transition temperature of the amorphous resin A - 5°C. The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <8>. <10> The temperature of the aqueous medium B that joins and mixes with the aqueous dispersion A is preferably equal to or higher than the glass transition temperature of the amorphous resin A and equal to or lower than the glass transition temperature of the amorphous resin A + 40°C, more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 10°C and equal to or lower than the glass transition temperature of the amorphous resin A + 35°C, still more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 15°C and equal to or lower than the glass transition temperature of the amorphous resin A + 30°C. The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <9>. <11> The temperature of the dispersion in the confluence part is preferably equal to or higher than the glass transition temperature of the amorphous resin A contained in the aggregated particles and equal to or lower than the glass transition temperature of the amorphous resin A + 40°C, more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 5°C and equal to or lower than the glass transition temperature of the amorphous resin A + 30°C, still more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 10°C and equal to or lower than the glass transition temperature of the amorphous resin A + 20°C. The method for producing a toner particle dispersion for electrostatic charge image development according to any one of <1> to <10>. <12> The temperature of the dispersion liquid downstream of the confluence section (inside the flow path after confluence) is preferably equal to or higher than the glass transition temperature of the amorphous resin A contained in the aggregated particles and equal to or lower than the glass transition temperature of the amorphous resin A + 40°C, more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 5°C and equal to or lower than the glass transition temperature of the amorphous resin A + 30°C, still more preferably equal to or higher than the glass transition temperature of the amorphous resin A + 10°C and equal to or lower than the glass transition temperature of the amorphous resin A + 20°C. The method for producing a toner particle dispersion liquid for electrostatic charge image development according to any one of <1> to <11>. <13> The aqueous medium B contains a dispersant. The method for producing a toner particle dispersion liquid for electrostatic charge image development according to any one of <1> to <12>. <14> The mixing ratio per unit time of the aqueous medium B to the aqueous dispersion liquid A in the confluence section (mass of the aqueous medium B / mass of the aqueous dispersion liquid A) is preferably 0.5 / 1 or more and 10 / 1 or less, more preferably 1 / 1 or more and 5 / 1 or less, still more preferably 1.5 / 1 or more and 3 / 1 or less, and even more preferably 2 / 1 or more and 3 / 1 or less. The method for producing a toner particle dispersion liquid for electrostatic charge image development according to any one of <1> to <13>. <15> The circularity of the fused particles is preferably 0.955 or more and 0.990 or less, more preferably 0.960 or more and 0.985 or less, still more preferably 0.965 or more and 0.980 or less. The method for producing a toner particle dispersion liquid for electrostatic charge image development according to any one of <1> to <14>.

Examples

[0137] The present invention will be described more specifically with reference to examples and the like below. In the following examples and the like, the measurement and evaluation of each physical property were carried out by the following methods.

[0138] [Measurement] [Acid value of resin] Measured according to JIS K0070:1992. However, the measurement solvent was a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0139] 〔Softening Point, Crystallinity Index, Melting Point, and Glass Transition Temperature of Resin〕 (1) Softening Point Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), while heating 1 g of the sample at a heating rate of 6 °C / min, a load of 1.96 MPa was applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The plunger descent amount of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point. (2) Crystallinity Index Using a differential scanning calorimeter “Q100” (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan and cooled to 0 °C at a cooling rate of 10 °C / min. Then the sample was left stationary for 1 minute, and then heated to 180 °C at a heating rate of 10 °C / min to measure the heat quantity. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was taken as the maximum endothermic peak temperature (1), and the crystallinity index was determined by (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)). (3) Melting Point and Glass Transition Temperature Using a differential scanning calorimeter “Q100” (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200 °C, and cooled from that temperature to 0 °C at a cooling rate of 10 °C / min. Then the sample was heated at a heating rate of 10 °C / min, and the heat quantity was measured. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was taken as the maximum endothermic peak temperature (2). In the case of a crystalline resin, the peak temperature was taken as the melting point. Also, in the case of an amorphous resin, when a peak was observed, the temperature of the peak was taken as the glass transition temperature. When no peak was observed but a step was observed, the temperature at the intersection of the tangent line showing the maximum slope of the curve at the step portion and the extension of the baseline on the low-temperature side of the step was taken as the glass transition temperature.

[0140] 〔Weight-Average Molecular Weight (Mw) of the Addition Polymer E〕 Using a solution prepared by dissolving phosphoric acid and lithium bromide in N,N-dimethylformamide at concentrations of 43 mmol / L and 50 mmol / L, respectively, as the eluent, gel permeation chromatography [manufactured by Tosoh Corporation, GPC apparatus (HLC-8320GPC), columns manufactured by Tosoh Corporation (TSKgel SuperAWM-H, TSKgel SuperAW3000, TSKgel guardcolumn Super AW-H), flow rate: 0.5 mL / min] was used to measure with a monodisperse polystyrene kit of known molecular weight [PStQuick B (F-550, F-80, F-10, F-1, A-1000), PStQuick C (F-288, F-40, F-4, A-5000, A-500), manufactured by Tosoh Corporation] as the standard substance. For the measurement sample, 0.1 g of the polymer was mixed with 10 mL of the above eluent in a glass vial, stirred with a magnetic stirrer at 25 °C for 10 hours, and filtered through a syringe filter (DISMIC-13HP PTFE 0.2 μm, manufactured by Advantec Co., Ltd.) for use.

[0141] 〔Melting point of the release agent〕 Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated up to 200 °C, and then cooled from 200 °C to 0 °C at a cooling rate of 10 °C / min. Next, the sample was heated up at a heating rate of 10 °C / min, and the heat quantity was measured, and the maximum peak temperature of the endotherm was taken as the melting point.

[0142] 〔Volume median diameter D of resin particles, colorant particles, and release agent particles 50 and CV value〕 (1) Measuring device: Laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.) (2) Measurement conditions: The sample dispersion was placed in the measurement cell, distilled water was added, and the volume median diameter D 50 and volume average diameter D v were measured at a concentration where the absorbance was within the appropriate range. Also, the CV value was calculated according to the following formula. CV value (%) = (standard deviation of the particle size distribution / volume average diameter D v ) × 100

[0143] 〔Solid content concentrations of resin particle dispersion, colorant particle dispersion, and release agent particle dispersion〕 Using an infrared moisture meter "FD-230" (manufactured by Kett Science Laboratory Co., Ltd.), 5 g of the measurement sample was measured for moisture (mass%) at a drying temperature of 150°C and a measurement mode of 96 (monitoring time: 2.5 minutes, fluctuation range of moisture content: 0.05%). The solid content concentration was calculated according to the following formula. Solid content concentration (mass%) = 100 - moisture (mass%)

[0144] 〔Volume median diameter D of aggregated particles 50 〕 The volume median diameter D of aggregated particles 50 was measured as follows. · Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) · Aperture diameter: 50 μm · Analysis software: "Multisizer (registered trademark) III Version 3.51" (manufactured by Beckman Coulter, Inc.) · Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) · Measurement conditions: The sample dispersion was added to 100 mL of the above electrolyte, and after adjusting the concentration to a level where the particle sizes of 30,000 particles could be measured in 20 seconds, 30,000 particles were measured again, and the volume median diameter D 50 was determined from the particle size distribution.

[0145] 〔Circularity of fused particles〕 The circularity of fused particles was measured under the following conditions. · Measuring device: Flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) · Preparation of dispersion: The dispersion of fused particles was prepared by diluting with deionized water so that the solid content concentration was 0.001 to 0.05 mass%. · Measurement mode: HPF measurement mode

[0146] 〔Volume median diameter D of toner particles 50 and CV value〕 The volume median diameter D of toner particles50 It was measured as follows. The measuring device, aperture diameter, analysis software, and electrolytic solution were the same as those used in the measurement of the volume median diameter D of the aggregated particles described above. 50 The same ones as those used in the measurement were used. · Dispersion liquid: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) was dissolved in the electrolytic solution to obtain a dispersion liquid with a concentration of 5% by mass. · Dispersion conditions: 10 mg of the measurement sample of the toner particles after drying was added to 5 mL of the dispersion liquid, and dispersed with an ultrasonic disperser for 1 minute. Then, 25 mL of the electrolytic solution was added, and further dispersed with an ultrasonic disperser for 1 minute to prepare a sample dispersion liquid. · Measurement conditions: By adding the sample dispersion liquid to 100 mL of the electrolytic solution, after adjusting to a concentration at which the particle diameters of 30,000 particles can be measured in 20 seconds, 30,000 particles were measured, and the volume median diameter D 50 and the volume average diameter D V were determined. Also, the CV value (%) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution / volume average diameter D V ) × 100

[0147] [Manufacture of Resin] [Manufacture of Amorphous Polyester Resin] Production Example A1 (Production of Resin A-1) Neopentyl glycol, terephthalic acid, and tin(II) bis(2-ethylhexanoate) shown in Table 1 were placed in a 10 L four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a cooling tube, and a nitrogen introduction tube, and heated to 180 °C in a mantle heater under a nitrogen atmosphere. After reacting for 2 hours, the temperature was gradually raised to 210 °C at a rate of 5 °C / h. Then, after cooling to 180 °C, isophthalic acid shown in Table 1 was added, the temperature was raised to 190 °C again, and after reacting for 1 hour, the temperature was gradually raised to 220 °C at a rate of 10 °C / h. Then, the reaction was carried out at 13.3 kPa until the softening point shown in Table 1 was reached to obtain Resin A-1. The physical property values are shown in Table 1.

[0148] Production Example B1 (Production of Resin B-1) 1,2-propanediol, terephthalic acid, and tin(II) bis(2-ethylhexanoate) shown in Table 1 were placed in a 10 L four-necked flask equipped with a nitrogen inlet tube, a distillation tube through which hot water at 98 °C was passed, a stirrer, and a thermocouple. After maintaining the reaction system at 180 °C for 1 hour under a nitrogen atmosphere, the temperature was raised from 180 °C to 230 °C at a rate of 10 °C / h, held at 230 °C for 5 hours, and polycondensed. Then, after cooling to 180 °C, 2 g of fumaric acid and 4-tert-butylcatechol were added to the reaction system, the temperature was raised from 180 °C to 230 °C at a rate of 10 °C / h, reacted at 230 °C for 1 hour, and reacted at 230 °C and 10 kPa to the softening point shown in Table 1 to obtain Resin B-1. The physical property values are shown in Table 1.

[0149] [Table 1]

[0150] [Production of Crystalline Polyester Resin] Production Example C1 (Production of Resin C-1) Ethylene glycol, sebacic acid, and stearic acid shown in Table 2 were placed in a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple under a nitrogen atmosphere. While stirring the reaction system, the temperature was raised to 135 °C, held at 135 °C for 3 hours, and then raised from 135 °C to 200 °C over 10 hours. Then, 10 g of tin(II) bis(2-ethylhexanoate) was added to the reaction system, held at 200 °C for 1 hour, the pressure in the flask was reduced, and held under a reduced pressure of 8 kPa for 1 hour to obtain Resin C-1, which is a crystalline polyester resin. The physical property values are shown in Table 2.

[0151] [Table 2]

[0152] [Production of Resin Particle Dispersion Liquid] Production Example X1a (Production of Resin Particle Dispersion Liquid X-1a) Into a 5 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 800 g of resin A-1, 200 g of resin C-1, and 1000 g of methyl ethyl ketone were added, and the resin was dissolved at 80 °C over 1 hour. To the resulting solution, a 5 mass% aqueous sodium hydroxide solution was added to a neutralization degree of 80 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 80 °C and stirring at 280 r / min, 3000 g of deionized water was added over 60 minutes to carry out phase inversion emulsification. Subsequently, while maintaining the temperature at 80 °C, methyl ethyl ketone was distilled off under reduced pressure to obtain a resin dispersion. Thereafter, while stirring at 280 r / min, the dispersion was cooled to 30 °C, and then deionized water was added so that the solid content concentration became 26 mass% to obtain a resin particle dispersion X-1a. The volume median diameter D of the resin particles in the obtained resin particle dispersion X-1a 50 and the CV value are shown in Table 3.

[0153] Production Example X1b (Production of Resin Particle Dispersion X-1b) A resin particle dispersion X-1b was obtained in the same manner as in Production Example X1a, except that deionized water was added so that the solid content concentration became 24 mass%. The volume median diameter D of the resin particles in the obtained resin particle dispersion X-1b 50 and the CV value are shown in Table 3.

[0154] Production Example Y1a (Production of Resin Particle Dispersion Y-1a) Into a 3 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 200 g of resin B-1 and 200 g of methyl ethyl ketone were placed and dissolved at 73 °C over 2 hours. To the resulting solution, a 5 mass% aqueous sodium hydroxide solution was added to a neutralization degree of 60 mol% with respect to the acid value of resin B-1, and the mixture was stirred for 30 minutes. Then, while maintaining the temperature at 73 °C and stirring at 200 r / min, 700 g of deionized water was added over 50 minutes to effect phase inversion emulsification. The resulting solution was kept at 73 °C, and methyl ethyl ketone was distilled off under reduced pressure to obtain a resin dispersion. Thereafter, while continuing stirring, the dispersion was cooled to 30 °C, and then deionized water was added so that the solid content concentration became 21 mass% to obtain a resin particle dispersion Y-1a. The volume median diameter D of the resin particles in the obtained resin particle dispersion Y-1a 50 and the CV value are shown in Table 3.

[0155] Production Example Y1b (Production of Resin Particle Dispersion Y-1b) A resin particle dispersion Y-1b was obtained in the same manner as in Production Example Y1a, except that deionized water was added so that the solid content concentration became 24 mass%. The volume median diameter D of the resin particles in the obtained resin particle dispersion Y-1b 50 and the CV value are shown in Table 3.

[0156] Production Example V1 (Production of Resin Particle Dispersion V-1) In a 3 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 200 g of resin A-1 and 200 g of methyl ethyl ketone were placed, and resin A-1 was dissolved at 80 °C over 1 hour. To the resulting solution, a 5 mass% aqueous sodium hydroxide solution was added to a neutralization degree of 75 mol% with respect to the acid value of resin A-1, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 80 °C and stirring at 280 r / min, 700 g of deionized water was added over 50 minutes to perform phase inversion emulsification. Subsequently, while maintaining the temperature at 80 °C, methyl ethyl ketone was distilled off under reduced pressure to obtain a resin dispersion. Thereafter, while stirring at 280 r / min, the dispersion was cooled to 30 °C, and then deionized water was added so that the solid content concentration became 20 mass% to obtain a resin particle dispersion V-1. The volume median diameter D of the resin particles in the obtained resin particle dispersion V-1 50 and the CV value are shown in Table 3.

[0157] [Table 3]

[0158] [Production of Release Agent Particle Dispersion] Production Example W1a (Production of Release Agent Particle Dispersion W-1a) To a 1 L beaker, 30 g of deionized water, 100 g of resin particle dispersion V-1, and 50 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75 °C) were added, and the temperature was maintained at 90 to 95 °C to melt and stir to obtain a molten mixture. While maintaining the temperature of the obtained molten mixture at 90 to 95 °C, it was dispersed using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Co., Ltd.) for 20 minutes and then cooled to room temperature (20 °C). Deionized water was added to adjust the solid content concentration to 40 mass% to obtain a release agent particle dispersion W-1a. The volume median diameter D of the release agent particles in the release agent particle dispersion W-1a 50 was 0.29 μm and the CV value was 37%.

[0159] Production Example W1b (Production of Release Agent Particle Dispersion W-1b) Deionized water was added, and a mold release agent particle dispersion liquid W-1b was obtained in the same manner as in Production Example W1a, except that the solid content concentration was adjusted to 39% by mass. The volume median particle diameter D of the mold release agent particles in the mold release agent particle dispersion liquid W-1b 50 was 0.29 μm, and the CV value was 37%.

[0160] Production Example W1c (Production of mold release agent particle dispersion liquid W-1c) Deionized water was added, and a mold release agent particle dispersion liquid W-1c was obtained in the same manner as in Production Example W1a, except that the solid content concentration was adjusted to 35% by mass. The volume median particle diameter D of the mold release agent particles in the mold release agent particle dispersion liquid W-1c 50 was 0.29 μm, and the CV value was 37%.

[0161] Production Example W2a (Production of mold release agent particle dispersion liquid W-2a) A mold release agent particle dispersion liquid W-2a was obtained in the same manner as in Production Example W1a, except that the type of mold release agent used was changed to Fischer-Tropsch wax "FNP-0090" (manufactured by Nippon Seiro Co., Ltd., melting point 90°C). The volume median particle diameter D of the mold release agent particles in the mold release agent particle dispersion liquid W-2a 50 was 0.26 μm, and the CV value was 39%.

[0162] Production Example W2b (Production of mold release agent particle dispersion liquid W-2b) Deionized water was added, and a mold release agent particle dispersion liquid W-2b was obtained in the same manner as in Production Example W2a, except that the solid content concentration was adjusted to 41% by mass. The volume median particle diameter D of the mold release agent particles in the mold release agent particle dispersion liquid W-2b 50 was 0.26 μm, and the CV value was 39%.

[0163] [Production method of addition polymer E] Production Example E 31 g of acrylic acid (reagent, manufactured by Fujifilm Wako Pure Chemical Corporation), 59 g of styrene (reagent, manufactured by Fujifilm Wako Pure Chemical Corporation), and 10 g of α-methylstyrene (reagent, manufactured by Fujifilm Wako Pure Chemical Corporation) were mixed to prepare a raw material monomer mixture. 10 g of methyl ethyl ketone, 0.3 g of 2-mercaptopropionic acid (polymerization chain transfer agent), and 10% by mass of the raw material monomer mixture were placed in a reaction vessel and mixed, and sufficient nitrogen gas substitution was performed. On the other hand, in a dropping funnel, a mixed solution of the remaining raw material monomer mixture, 0.27 g of the polymerization chain transfer agent, 40 g of methyl ethyl ketone, and 1.1 g of an azo radical polymerization initiator (V-501 manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.; 4,4'-azobis(4-cyanovaleric acid)) was placed. While stirring the monomer mixture in the reaction vessel under a nitrogen atmosphere, the temperature was raised to 65°C, and the mixed solution in the dropping funnel was dropped over 3 hours. After 2 hours had elapsed at 65°C from the end of the dropping, a solution prepared by dissolving 0.15 g of the polymerization initiator in 2.5 g of methyl ethyl ketone was added, and the reaction was allowed to proceed at 65°C for 2 hours and then at 70°C for 2 hours to obtain a solution of an addition polymer E having a carboxy group (weight average molecular weight: 11,800, acid value 240 mgKOH / g, glass transition temperature 101.75°C).

[0164]

Table 4

[0165] [Production of Colorant Particle Dispersion Liquid] Production Example E1a (Production of Colorant Particle Dispersion Liquid E-1a) 17 g of addition polymer E and 630 g of methyl ethyl ketone were placed in a 5 L container equipped with a stirrer with a dispersing blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, and the resin was dissolved at 20°C. To the resulting solution, 11 g of a 5% by mass aqueous sodium hydroxide solution (an amount that gives a neutralization degree of 80 mol% of addition polymer E) was added, and further 955 g of deionized water was added, and the mixture was stirred at 2000 r / min at 20°C for 10 minutes with a dispersing blade. Next, 300 g of C.I. Pigment Blue 15:3 (manufactured by Dainichi Seika Co., Ltd., "ECB301", molecular weight 576) was added, and stirring was carried out at 20 °C for 2 hours at 6400 r / min with a dispersing blade. Then, it was passed through a 200-mesh filter and treated for 15 passes at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). While stirring the obtained dispersion, methyl ethyl ketone and a part of water were removed at 70 °C under reduced pressure. After cooling, deionized water was added through a 200-mesh filter so that the solid content concentration became 21% by mass, thereby obtaining a colorant particle dispersion E-1a. The volume median diameter D of the colorant particles in the colorant particle dispersion E-1a 50 was 0.08 μm, and the CV value was 20%.

[0166] Production Example E1b (Production of Colorant Particle Dispersion E-1b) A colorant particle dispersion E-1b was obtained in the same manner as in Production Example E1a, except that deionized water was added so that the solid content concentration became 20% by mass. The volume median diameter D of the colorant particles in the colorant particle dispersion E-1b 50 was 0.08 μm, and the CV value was 20%.

[0167] [Production of Toner Particle Dispersion] Example 1 Using the apparatus 200 shown in FIG. 2, toner particles were obtained as follows. Into a four-necked flask (aqueous dispersion A supply tank 10) with an internal volume of 3 liters (inner diameter 16 cm) equipped with a stirring device (supermix blade (blade diameter 10 cm) and a thermocouple), 610 g of resin particle dispersion X-1a (solid content concentration 26% by mass), 42 g of release agent particle dispersion W-1a (solid content concentration 40% by mass), 41 g of release agent particle dispersion W-2a (solid content 40% by mass), 66 g of colorant particle dispersion E-1a (solid content concentration 21% by mass), and 1.6 g of a 5% by mass aqueous solution of a nonionic surfactant "ADEKA (registered trademark) Pluronic P-84" (manufactured by ADEKA Corporation), and 62 g of deionized water were mixed at a temperature of 25 °C. Next, while stirring the obtained mixture at a stirring rotation speed of 200 r / min, an aqueous solution prepared by dissolving 38 g of ammonium sulfate in 946 g of deionized water was added with a 4.8 mass% potassium hydroxide aqueous solution to adjust the pH to 8.2, and the adjusted solution was added dropwise at 25°C over 30 minutes. Then, the temperature was raised to 54°C over 1 hour and 30 minutes, and the mixture was held at 54°C until the volume median diameter D 50 of the aggregated particles reached 5.9 μm, and a dispersion of aggregated particles 1 was obtained. After cooling the obtained dispersion of aggregated particles 1 to 50°C, 113 g of a resin particle dispersion Y-1a (solid content concentration: 21 mass%) was added over 1 hour to obtain a dispersion (aqueous dispersion A, solid content concentration: 11.9 mass%) of aggregated particles 2 (aggregated particles having a core-shell structure, the glass transition temperature (weight average) of the amorphous polyester resin in the aggregated particles 2 being 58.4°C, and the content of the amorphous polyester resin in the aggregated particles 2 being 70 mass%). 357 g of a 30 mass% aqueous solution of an anionic surfactant "Demol N" (sodium salt of β-naphthalene sulfonic acid formalin condensate, manufactured by Kao Corporation), 50 g of a 4.8 mass% potassium hydroxide aqueous solution, and 3593 g of deionized water were poured into a 5-liter plastic container (aqueous medium B supply tank 20) and mixed to prepare an aqueous dispersant solution (aqueous medium B). From the aqueous dispersion A supply tank 10, the aqueous dispersion A was circulated through the aqueous dispersion A supply flow path 1 at 30 mL / min (average linear velocity: 62 mm / s) using a mono pump (model 2NL-PU, manufactured by Heishin Sobi Co., Ltd.) and passed through a heat exchanger H2 (double-tube heat exchanger) arranged in the aqueous dispersion A supply flow path 1 to raise the temperature to 50°C. Also, from the aqueous medium B supply tank 20, the aqueous medium B was circulated through the aqueous medium B supply flow path 2 at 60 mL / min (average linear velocity: 123 mm / s) using a pulse-free plunger pump (model NP-KX-500, manufactured by Nippon Seimitsu Kagaku Co., Ltd.) and passed through a heat exchanger H3 (double-tube heat exchanger) arranged in the aqueous medium B supply flow path 2 to raise the temperature to 85°C. The aqueous dispersion A and the aqueous medium B were continuously mixed at the confluence J1 (mixing temperature: 73°C), and the flow path 3 was maintained at 73°C using a belt heater, and the mixed dispersion was circulated through the flow path 3. The mixing ratio of the aqueous medium B to the aqueous dispersion A per unit time (mass of the aqueous medium B / mass of the aqueous dispersion A) in the confluence section J1 was 2 / 1. The mixed dispersion (solid content concentration: 3.9% by mass) was passed through the flow path 3 until the circularity reached 0.970, the resin particles 2 were fused, and then collected in the recovery tank 30. The dispersion collected in the recovery tank 30 was cooled to 30°C to obtain a toner particle dispersion. Furthermore, after the dispersion was suction filtered to separate the solid content, it was washed with deionized water and dried at 33°C to obtain toner particles. The volume median diameter D of the toner particles 50 and the like are shown in Table 5. Note that the solid content concentrations of the aqueous dispersion A, the dispersion of the fused particles, and the toner particle dispersion were calculated with the total amount of the resin, the colorant, and the release agent, which are toner raw materials, as the solid content. The same applies hereinafter.

[0168] (Example 2) Using the apparatus shown in FIG. 2, toner particles were obtained as follows. Into a four-necked flask (aqueous dispersion A supply tank 10) with an internal volume of 3 liters (inner diameter 16 cm) equipped with a stirring device (supermix blade (blade diameter 10 cm) and a thermocouple), 600 g of a resin particle dispersion X-1b (solid content concentration: 24% by mass), 39 g of a release agent particle dispersion W-1b (solid content concentration: 39% by mass), 37 g of a release agent particle dispersion W-2b (solid content: 41% by mass), 61 g of a colorant particle dispersion E-1b (solid content concentration: 20% by mass), and 1.4 g of a 5% by mass aqueous solution of a nonionic surfactant "ADEKA (registered trademark) Pluronic P-84" (manufactured by ADEKA CORPORATION), and 119 g of deionized water were mixed at a temperature of 25°C. Next, while stirring the obtained mixture at a stirring rotation speed of 250 r / min, an aqueous solution prepared by dissolving 39 g of ammonium sulfate in 408 g of deionized water and adding a 4.8% by mass aqueous potassium hydroxide solution to adjust the pH to 8.2 was added dropwise at 25°C over 1 hour, and then the temperature was raised to 54°C over 1 hour and 30 minutes. The volume median diameter D of the aggregated particles 50 was maintained at 54°C until it reached 5.9 μm to obtain a dispersion of the aggregated particles 1. After cooling the dispersion of the obtained aggregated particles 1 to 48°C, 89 g of the resin particle dispersion Y-1b (solid content concentration: 24% by mass) was added over 1 hour, and a dispersion of aggregated particles 2 (aggregated particles having a core-shell structure, glass transition temperature (weight average) of the amorphous polyester resin in the aggregated particles 2: 58.4°C, content of the amorphous polyester resin in the aggregated particles 2: 70% by mass) (aqueous dispersion A, solid content concentration: 14.8% by mass) was obtained. 469 g of a 20% by mass aqueous solution of the anionic surfactant "Demol N" (sodium salt of β-naphthalenesulfonic acid formalin condensate, manufactured by Kao Corporation), 11 g of a 4.8% by mass aqueous potassium hydroxide solution, and 3323 g of deionized water were poured into a 5-liter plastic container (aqueous medium B supply tank 20) and mixed to prepare an aqueous dispersant solution (aqueous medium B). From the aqueous dispersion A supply tank 10, the aqueous dispersion A was circulated through the aqueous dispersion A supply flow path 1 at 24.3 mL / min (average linear velocity: 50 mm / s) using a monopump (model 2NL-PU, manufactured by Heishin Sobi Co., Ltd.) and passed through a heat exchanger H2 (double-tube heat exchanger) arranged in the aqueous dispersion A supply flow path 1 to raise the temperature to 48°C. Further, from the aqueous medium B supply tank 20, the aqueous medium B was circulated through the aqueous medium B supply flow path 2 at 65.7 mL / min (average linear velocity: 135 mm / s) using a pulse-free plunger pump (model NP-KX-500, manufactured by Nippon Seimitsu Kagaku Co., Ltd.) and passed through a heat exchanger H3 (double-tube heat exchanger) arranged in the aqueous medium B supply flow path 2 to raise the temperature to 83°C. The aqueous dispersion A and the aqueous medium B were continuously mixed at the confluence part J1 (mixing temperature: 72°C), and the flow path 3 was maintained at 72°C using a belt heater, and the mixed dispersion was circulated through the flow path 3. The mixing ratio per unit time of the aqueous medium B to the aqueous dispersion A at the confluence part J1 (mass of the aqueous medium B / mass of the aqueous dispersion A) was 2.7 / 1. The mixed dispersion (solid content concentration: 4.0% by mass) was circulated through the flow path 3 until the circularity reached 0.970, the resin particles 2 were fused, and then collected in the collection tank 30. The dispersion collected in the collection tank 30 was cooled to 30°C to obtain a toner particle dispersion. Furthermore, after suction filtering the dispersion liquid to separate the solid content, it was washed with deionized water and dried at 33 °C to obtain toner particles. The volume median diameter D of the toner particles 50 and the like are shown in Table 5.

[0169] (Comparative Example 1) Into a 3-liter (inner diameter 16 cm) four-necked flask equipped with a stirring device (supermix blade (blade diameter 10 cm) and a thermocouple), 400 g of resin particle dispersion liquid X-1a (solid content concentration 26% by mass), 27 g of mold release agent particle dispersion liquid W-1a (solid content concentration 40% by mass), 27 g of mold release agent particle dispersion liquid W-2a (solid content concentration 40% by mass), 43 g of colorant particle dispersion liquid E-1a (solid content concentration 21% by mass), and 1.0 g of a 5% by mass aqueous solution of a nonionic surfactant "Adeka (registered trademark) Pluronic P-84" (manufactured by ADEKA CORPORATION), and 122 g of deionized water were mixed at a temperature of 25 °C. Next, while stirring the obtained mixture at a stirring rotation speed of 200 r / min, an aqueous solution prepared by dissolving 23 g of ammonium sulfate in 293 g of deionized water and adding a 4.8% by mass aqueous potassium hydroxide solution to adjust the pH to 8.2 was added dropwise at 25 °C over 30 minutes, and then the temperature was raised to 54 °C over 1 hour and 30 minutes. The volume median diameter D of the aggregated particles 50 was maintained at 54 °C until it reached 5.9 μm to obtain a dispersion liquid of aggregated particles 1. After cooling the obtained dispersion liquid of aggregated particles 1 to 50 °C, 73 g of resin particle dispersion liquid Y-1 (solid content concentration 21% by mass) was added at 50 °C over 1 hour to obtain a dispersion liquid of aggregated particles 2 (aggregated particles having a core-shell structure) (aqueous dispersion liquid A, solid content concentration 14.8% by mass). Thereafter, to the aqueous dispersion liquid A, 144 g of a 40% by mass aqueous solution of an anionic surfactant "Demol N" (sodium salt of β-naphthalenesulfonic acid formalin condensate, manufactured by Kao Corporation), 24 g of a 48% by mass aqueous potassium hydroxide solution, and 72 g of deionized water were added, and the temperature was raised to 73 °C over 1 hour and maintained at 73 °C until the circularity reached 0.970 to obtain a dispersion liquid of fused particles (solid content concentration 11.9% by mass). The dispersion of the obtained fused particles was cooled to 30 °C, and after separating the solid content of the dispersion by suction filtration, it was washed with deionized water and dried at 33 °C to obtain toner particles. The volume median diameter D of the toner particles 50 and the like are shown in Table 5.

[0170] (Comparative Example 2) Into a 4-necked flask with an internal volume of 3 liters (inner diameter 16 cm) equipped with a stirring device (supermix blade (blade diameter 10 cm) and a thermocouple), 230 g of resin particle dispersion X-1a (solid content concentration 26% by mass), 19 g of mold release agent particle dispersion W-1c (solid content concentration 35% by mass), 17 g of mold release agent particle dispersion W-2a (solid content concentration 40% by mass), 26 g of colorant particle dispersion E-1a (solid content concentration 21% by mass), and 0.63 g of a 5% by mass aqueous solution of a nonionic surfactant "ADEKA (registered trademark) Pluronic P-84" (manufactured by ADEKA Corporation), and 82 g of deionized water were mixed at a temperature of 25 °C. Next, while stirring the obtained mixture at a stirring rotation speed of 200 r / min, a solution prepared by adding a 4.8% by mass aqueous potassium hydroxide solution to an aqueous solution in which 23 g of ammonium sulfate was dissolved in 678 g of deionized water and adjusted to pH 8.2 was added dropwise at 25 °C over 30 minutes, and then the temperature was raised to 54 °C over 1 hour and 30 minutes. The volume median diameter D of the aggregated particles 50 was maintained at 54 °C until it reached 5.9 μm to obtain a dispersion of aggregated particles 1. After cooling the obtained dispersion of aggregated particles 1 to 50 °C, 44 g of resin particle dispersion Y-1a (solid content concentration 21% by mass) was added at 50 °C over 1 hour to obtain a dispersion of aggregated particles 2 (aggregated particles having a core-shell structure) (aqueous dispersion A, solid content concentration 8.0% by mass). Thereafter, 87 g of a 20% by mass aqueous solution of an anionic surfactant "Demol N" (sodium salt of β-naphthalenesulfonic acid formalin condensate, manufactured by Kao Corporation), 241 g of a 4.8% by mass aqueous potassium hydroxide solution, and 784 g of deionized water were added to the aqueous dispersion A, and the temperature was raised to 73 °C over 1 hour and maintained at 73 °C until the circularity reached 0.970 to obtain a dispersion of fused particles (solid content concentration 4.0% by mass). The dispersion of the obtained fused particles was cooled to 30°C, and after separating the solid content of the dispersion by suction filtration, it was washed with deionized water and dried at 33°C to obtain toner particles. The volume median particle diameter D of the toner particles 50 etc. are shown in Table 5.

[0171] [Evaluation Method] [Amount of Coarse Particles in Toner Particle Dispersion] The cooled toner particle dispersion (dispersion of fused particles) was measured under the following conditions. · Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) · Aperture diameter: 50 μm · Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) · Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) · Measurement conditions: By adding the sample dispersion to 100 mL of the electrolyte, the concentration was adjusted to a concentration at which the particle sizes of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured again, and the ratio of the particles present in the range of 10 μm to 30 μm in the obtained volume particle size distribution was calculated as the amount of coarse particles. [Productivity of Toner Particles (Comparison of Solid Content Concentrations of Aqueous Dispersion A Containing Agglomerated Particles)] Since there is almost no difference in time between the process of obtaining fused particles from agglomerated particles by flow-type fusion and batch-type fusion, the difference in the productivity of the aqueous dispersion A containing agglomerated particles was compared by assuming the same production amount of the aqueous dispersion and setting the solid content concentration of the aqueous dispersion A in Comparative Example 2 as "1.0".

[0172]

Table 5

[0173] From Table 5, it can be seen that by the production method of the present invention, a toner particle dispersion with a small amount of coarse particles was obtained using the aqueous dispersion A with a solid content concentration of 11.9 or 14.8% by mass. That is, by using the aqueous dispersion A with a relatively high concentration by the production method of the present invention, a toner particle dispersion with a small amount of coarse particles can be obtained with high productivity (Examples 1 and 2). On the other hand, in Comparative Example 1 where the fusion step was carried out batchwise using the aqueous dispersion A with the same solid content concentration as in Example 2, the amount of coarse particles in the toner particles was large. The solid content concentration of the toner particle dispersion in Comparative Example 1 is higher than that in Example 2, but this is because the batch capacity is limited and it cannot be reduced to the same concentration as in Example 2. Also, even in the case of Comparative Example 2 where the productivity was lowered and the aqueous dispersion A with a solid content concentration lower than that in the examples was used and the toner particle dispersion with the same concentration as in the examples was produced, the amount of coarse particles was larger compared to the examples. Since the production method of the present invention performs the fusion step in a flow type, the production amount of the aggregation step is not limited by the batch capacity, and the toner particle dispersion can be produced. Therefore, compared with the production method that performs the fusion step in a batch type, the productivity is high, and the amount of coarse particles in the obtained toner particle dispersion is also low.

Explanation of symbols

[0174] 1 Aqueous dispersion A supply channel 2 Aqueous medium B supply channel 3, 4, 5, 6 Channels J1 Confluence part M1 Stirring part H1, H2, H3, C1 Heat exchangers 10 Aqueous dispersion A supply tank (stirring tank) 20 Aqueous medium B supply tank 30 Recovery tank 100, 200 Devices

Claims

1. A method for producing a toner particle dispersion for developing an electrostatic image, comprising a flow-type fusion step in which an aqueous dispersion A of aggregated particles containing an amorphous resin A and an aqueous medium B are introduced into different flow paths, respectively, and allowed to flow together, and at a junction, the aqueous dispersion A and the aqueous medium B are continuously mixed to obtain a dispersion, and at the junction and / or in the flow path after the junction, the aggregated particles in the dispersion are fused at a temperature equal to or higher than the glass transition temperature of the amorphous resin A to obtain a dispersion containing fused particles.

2. 2. The method for producing a toner particle dispersion liquid for developing an electrostatic image according to claim 1, further comprising a step of cooling the dispersion liquid containing the fused particles obtained in the flow type fusion step after discharging the dispersion liquid from a flow path.

3. 3. The method for producing a toner particle dispersion for developing electrostatic images according to claim 1, wherein the aqueous dispersion A to be joined and mixed with the aqueous medium B has a solids concentration of 8% by mass or more.

4. 3. The method for producing a toner particle dispersion for developing electrostatic images according to claim 1, wherein the temperature of the aqueous dispersion A to be joined and mixed with the aqueous medium B is lower than the glass transition temperature of the amorphous resin A.

5. 3. The method for producing a toner particle dispersion for developing electrostatic images according to claim 1, wherein the temperature of the aqueous medium B to be joined and mixed with the aqueous dispersion A is equal to or higher than the glass transition temperature of the amorphous resin A.

6. The method for producing a toner particle dispersion for developing electrostatic images according to claim 1 or 2, wherein the aqueous medium B contains a dispersant.

7. 3. The method for producing a toner particle dispersion liquid for developing electrostatic images according to claim 1, wherein a mixing ratio per unit time of the aqueous medium B to the aqueous dispersion A at the confluence (mass of the aqueous medium B / mass of the aqueous dispersion A) is 0.5 / 1 or more and 10 / 1 or less.

8. The method for producing a toner particle dispersion for developing electrostatic images according to claim 1 or 2, wherein the amorphous resin A comprises an amorphous polyester resin A.

Images