Method for manufacturing toner for electrostatic charge image development

Abstract

To provide a method for manufacturing a toner for electrostatic charge image development capable of obtaining a printed matter with high image density and dot reproducibility.SOLUTION: A method for manufacturing a toner for electrostatic image development comprises a step of aggregating and fusing resin particles and colorant particles in an aqueous medium. In the method for manufacturing a toner for electrostatic image development, the colorant particles are obtained by a step of mixing particles containing a colorant and an addition polymer of a raw material monomer containing an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxyl group, and a monofunctional compound that has in a molecule one functional group that is reactive with a carboxy group.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a toner for developing electrostatic images used in developing latent images formed in electrophotography, electrostatic recording, electrostatic printing and the like. [Background technology]

[0002] In the field of electrophotography, with the development of electrophotographic systems, there is a demand for the development of electrophotographic toners that can meet the demands of higher image quality and higher speeds. In order to meet the demands of higher image quality, a method for obtaining a toner with a narrow particle size distribution and small particle size is being carried out, in which fine resin particles or the like are aggregated and fused in an aqueous medium to obtain a toner, so-called chemical toners are produced by an aggregation fusion method (also called an emulsion aggregation method or an aggregation coalescence method).

[0003] Patent Document 1 describes a method for producing a toner that can provide a high image density and excellent charging stability, the method including a process for aggregating and fusing resin particles and colorant particles in an aqueous medium, the resin particles containing a polyester resin segment, an addition polymerized resin segment that is an addition polymer of a raw material monomer containing a styrene-based compound, and a composite resin containing a structural unit derived from a bireactive monomer bonded to the polyester resin segment and the addition polymerized resin segment via a covalent bond, the colorant particles containing a colorant and an addition polymer of a raw material monomer containing a styrene-based compound, the addition polymer containing a structural unit derived from the styrene-based compound in its main chain, and the mass ratio of the colorant to the addition polymer in the colorant particles is 50 / 50 or more and 95 / 5 or less. Furthermore, Patent Document 2 describes a method for producing a toner for developing electrostatic images, the method comprising a step of aggregating and fusing resin particles, crosslinked colorant particles, and release agent particles in an aqueous medium, the crosslinked colorant particles being obtained by a production method comprising a step of mixing colorant particles with a polyfunctional compound having a plurality of functional groups selected from oxazoline groups, carbodiimide groups, epoxy groups, and aziridine groups, the colorant particles being particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, for the purpose of providing a toner for developing electrostatic images and a production method thereof, which can provide a toner having excellent charge stability and durability in a high-temperature and high-humidity environment. Furthermore, Patent Document 3 describes a toner containing toner particles including a binder resin, a pigment having a structure derived from a basic compound, a resin having an acidic functional group, and a fixing aid, for the purpose of providing a toner and a method for producing the toner, which have improved pigment dispersibility compared to conventional toners and are excellent in low-temperature fixing property and heat-resistant storage property, and is characterized in that the glass transition temperatures of the binder resin and the fixing aid satisfy a specific relationship, and when the hydrophobic parameter of the resin having an acidic functional group is HP1 and the hydrophobic parameter of the fixing aid is HP2, HP1 is 0.60 or more, and HP1 and HP2 satisfy a specific relationship. Furthermore, Patent Document 4 describes a toner for developing electrostatic images having toner particles containing a polyester resin (a), a styrene acrylic resin (b) having a moiety selected from the group consisting of a carboxyl group and a hydroxyl group, and a primary alcohol (c) having 2 to 13 carbon atoms, for the purpose of providing a toner for developing electrostatic images in which the difference in charging performance due to changes in humidity environment is reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-139229 A [Patent Document 2] JP 2020-201416 A [Patent Document 3] JP 2017-173811 A [Patent Document 4] JP 2015-152784 A Summary of the Invention [Problem to be solved by the invention]

[0005] The manufacturing method described in Patent Document 1 provides a toner that provides high image density and excellent charge stability, but there is room for improvement in the dot reproducibility of the resulting image. The toner manufactured by the manufacturing method described in Patent Document 2 provides a toner that is excellent in charge stability and durability in a high-temperature, high-humidity environment, but there is room for improvement in the dot reproducibility of the resulting image. Furthermore, the toner described in Patent Document 3 has improved coloring power, and is also excellent in low-temperature fixability and heat-resistant storage stability, but there is room for improvement in the image density and dot reproducibility of the resulting image. Furthermore, the toner described in Patent Document 4 reduces the difference in charge performance due to changes in the humidity environment, but there is room for improvement in the image density and dot reproducibility of the resulting image. The present invention relates to a method for producing a toner for developing electrostatic images, which can provide a printed matter having high image density and dot reproducibility, and a method for producing a colorant particle dispersion liquid that can be used in the production method. [Means for solving the problem]

[0006] The present inventors have found that by using colorant particles obtained by a process of mixing particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, with a monofunctional compound having one functional group in the molecule that is reactive with a carboxy group, it is possible to obtain a toner for developing electrostatic images that can produce printed matter with high image density and dot reproducibility. The present invention relates to the following [1] and [2]. [1] A method for producing a toner for developing electrostatic images, comprising a process for aggregating and fusing resin particles and colorant particles in an aqueous medium, wherein the colorant particles are obtained by a process for mixing particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, with a monofunctional compound having one functional group in the molecule that is reactive with a carboxy group. [2] A method for producing a colorant particle dispersion liquid, comprising the following steps a to c: Step a: mixing an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group with an organic solvent, and then further mixing with an aqueous medium to obtain a dispersion of the addition polymer; Step b: A step of dispersing the dispersion obtained in step a and a colorant to obtain a dispersion of particles containing a colorant and an addition polymer. Step c: mixing the dispersion of particles containing the colorant and the addition polymer obtained in step b with a monofunctional compound having one functional group reactive with a carboxy group in the molecule. Effect of the Invention

[0007] According to the present invention, there are provided a method for producing a toner for developing electrostatic images, which can give printed matter with high image density and dot reproducibility, and a method for producing a colorant particle dispersion liquid that can be used in the method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Method of manufacturing toner for developing electrostatic images] The method for producing the toner for developing electrostatic images (hereinafter, also simply referred to as "toner") of the present invention includes a process for aggregating and fusing resin particles and colorant particles in an aqueous medium. The colorant particles are obtained by a process for mixing particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, with a monofunctional compound having one functional group reactive with a carboxy group in the molecule. According to the above-mentioned manufacturing method, a toner for developing electrostatic images can be obtained which can give printed matter having high image density and dot reproducibility.

[0009] The detailed mechanism by which a toner for developing electrostatic images that can give printed matter with high image density and dot reproducibility is obtained by the production method of the present invention is not clear, but is thought to be as follows. The method for producing the toner in the present invention includes a step of aggregating and fusing resin particles and colorant particles in an aqueous medium. The colorant particles are obtained by a process of mixing particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, with a monofunctional compound having one functional group in the molecule that is reactive with a carboxy group. The addition polymer used to disperse the colorant contains a structure derived from an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, so that it is possible to achieve both compatibility with the hydrophobic portion of the colorant due to the structure derived from the addition polymerizable monomer having an aromatic group and dispersion stability in water due to the structure derived from the addition polymerizable monomer having a carboxy group, and contribute to improving the dispersion stability of the colorant in water. On the other hand, the colorant dispersed with the addition polymer has high dispersion stability in an aqueous medium, so that it has low coagulation in water compared to resin particles, resulting in a difference in the coagulation rate. As a result, the aggregated particles with a high proportion of the colorant dispersed with the addition polymer are less likely to grow in particle size, and are present in large amounts in the toner as small toner particles due to fusion. Small toner particles have a higher frequency of contact with a charging member than large toner particles, and are easily overcharged. Overcharged toner may be developed in areas that should not be developed, so toners containing a large number of small toner particles have a negative effect on dot reproducibility during image formation. In contrast, in the present invention, a monofunctional compound having reactivity with the terminal carboxyl group of the addition polymer is mixed with particles containing a colorant and an addition polymer to prepare colorant particles, thereby reducing the electrostatic repulsion of the colorant particles due to the carboxylic acid, and reducing the excessively high dispersion stability in an aqueous medium. In addition, in the process of aggregating the resin particles and the colorant particles, three-dimensional entanglement of molecular chains occurs between the structure derived from the monofunctional compound on the surface of the colorant particles and the polymer on the surface of the resin particles, improving the aggregability between the particles and generating aggregated particles of the colorant particles and the resin particles. Subsequently, the aggregated particles of the colorant particles and the resin particles further aggregate, thereby mitigating the difference in the aggregation speed between the colorant particles and the resin particles, and uniform aggregation occurs between each particle, which is believed to result in a toner having a high proportion of toner particles with a desired particle size and a low proportion of small toner particles. As a result, the chargeability of the toner particles becomes uniform, and a toner with improved dot reproducibility is obtained.

[0010] The definitions of various terms used in this specification are given below. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to produce a carboxylic acid, and alkyl esters of each carboxylic acid (alkyl groups having 1 to 3 carbon atoms). Whether a 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 endothermic peak temperature (softening point (°C) / maximum endothermic peak temperature (°C)) in the measurement method described in the examples below. A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or, if observed, has a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted by the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate. With respect to hydrocarbon groups, the references "(iso or tertiary)" and "(iso)" in parentheses refer to both the cases with and without the prefixes present; the absence of the prefixes indicates normal. "(Meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid. "(Meth)acrylate" means at least one selected from acrylate and methacrylate. By "styrenic compound" is meant unsubstituted or substituted styrene.

[0011] A method for producing a toner according to one embodiment of the present invention includes, for example, A step of aggregating resin particles and colorant particles in an aqueous medium to obtain aggregated particles (hereinafter also referred to as "step 1"); and A step of fusing the aggregated particles in an aqueous medium (hereinafter also referred to as "step 2"). Includes.

[0012] ≪Process 1≫ In step 1, resin particles and colorant particles are aggregated in an aqueous medium to obtain aggregated particles. In step 1, in addition to the resin particles and colorant particles, other additives such as release agent particles may also be aggregated.

[0013] <Resin particles> In step 1, the resin particles preferably contain an amorphous resin A (hereinafter also referred to as "resin A").

[0014] In the present invention, from the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the resin particles preferably contain at least resin A, and more preferably contain, as resin A, an amorphous polyester resin A1 (hereinafter also referred to as "resin A1").

[0015] [Amorphous polyester resin A1 (resin A1)] The amorphous polyester resin A1 contains an amorphous polyester resin or a polyester resin segment which is a polycondensation product of an alcohol component including a diol compound and a carboxylic acid component including a dicarboxylic acid compound. Examples of the resin A1 include polyester resin and modified polyester resin. Examples of the modified polyester resin include urethane modified polyester resin, epoxy modified polyester resin, and composite resin containing polyester resin segment and addition polymerization resin segment. Among these, polyester resin and composite resin are preferred.

[0016] Examples of the alcohol component include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0017] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 each independently represents an ethylene group or a propylene group, x and y represent the average number of moles of alkylene oxide added and are each positive numbers, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, and more preferably 4 or less. Examples of the alkylene oxide adduct of bisphenol A include a propylene oxide adduct of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination. Among these, a propylene oxide adduct of bisphenol A is preferred. When the alkylene oxide adduct of bisphenol A is a propylene oxide adduct of bisphenol A, it is preferred because a toner capable of producing a printed matter with high image density and dot reproducibility can be obtained. The amount of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %.

[0018] Examples of linear or branched aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol. Among these, 1,2-propanediol is preferred. When the linear or branched aliphatic diol is 1,2-propanediol, a toner that can produce a printed matter with high image density and dot reproducibility is obtained, which is preferable. Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and adducts of hydrogenated bisphenol A with alkylene oxides having 2 to 4 carbon atoms (average number of moles added: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.

[0019] The amount of the linear or branched aliphatic diol in the alcohol component is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %.

[0020] Examples of the carboxylic acid component include dicarboxylic acids and polycarboxylic acids having three or more carboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. When the alcohol component is an alkylene oxide adduct of an aromatic diol, the amount of the aromatic dicarboxylic acid in the carboxylic acid component is preferably 40 mol % or more, more preferably 45 mol % or more, and preferably 75 mol % or less, more preferably 70 mol % or less. When the alcohol component is an alcohol component other than an alkylene oxide adduct of an aromatic diol, the amount of the aromatic dicarboxylic acid in the carboxylic acid component is preferably 75 mol % or more, more preferably 80 mol % or more, and preferably 95 mol % or less, more preferably 90 mol % or less.

[0021] The linear or branched aliphatic dicarboxylic acid preferably has 2 or more, more preferably 3 or more, and preferably has 30 or less, more preferably 20 or less. Examples of linear or branched aliphatic dicarboxylic acids 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 a hydrocarbon group having 1 to 20 carbon atoms. Examples of succinic acid substituted with a hydrocarbon group having 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, fumaric acid and succinic acid substituted with an alkyl or alkenyl group are preferred.

[0022] When the alcohol component is an alkylene oxide adduct of an aromatic diol, the amount of linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably 10 mol % or more, more preferably 20 mol % or more, even more preferably 25 mol % or more, and preferably 60 mol % or less, more preferably 50 mol % or less, even more preferably 45 mol % or less. When the alcohol component is an alcohol component other than an alkylene oxide adduct of an aromatic diol, the amount of linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably 5 mol % or more, more preferably 8 mol % or more, even more preferably 10 mol % or more, and is preferably 25 mol % or less, more preferably 20 mol % or less.

[0023] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, and examples thereof include trimellitic acid and its anhydride. When a trivalent or higher polycarboxylic acid is contained, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component is preferably 5 mol % or more, more preferably 8 mol % or more, even more preferably 10 mol % or more, and is preferably 30 mol % or less, more preferably 20 mol % or less, even more preferably 15 mol % or less. These carboxylic acid components may be used alone or in combination of two or more.

[0024] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) is preferably 0.8 or more, more preferably 0.9 or more, and is preferably 1.2 or less, more preferably 1.1 or less.

[0025] The addition polymerized resin segment is, for example, an addition polymer of raw material monomers including a styrene-based compound. Examples of the styrene-based compound include unsubstituted or substituted styrene. Examples of the substituent substituted on styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group, or a salt thereof. Examples of styrene-based compounds include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid, and salts thereof. Among these, styrene is preferred. The content of the styrene-based compound in the raw material monomers of the addition polymerization resin segment is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even 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, even more preferably 85% by mass or less.

[0026] Examples of raw material monomers other than styrene-based compounds include (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylates are more preferred. The number of carbon atoms in the alkyl group in the alkyl (meth)acrylate is preferably 1 or more, more preferably 4 or more, even more preferably 6 or more, and is preferably 24 or less, more preferably 22 or less, even more preferably 20 or less. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso- or tertiary)butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate. Of these, 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate is preferred, 2-ethylhexyl acrylate and stearyl (meth)acrylate are more preferred, and stearyl methacrylate is even more preferred.

[0027] In the raw material monomers of the addition polymerization resin segment, the content of the (meth)acrylic acid ester is preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 15 mass% or more, and preferably 50 mass% or less, more preferably 35 mass% or less, even more preferably 25 mass% or less. The total amount of the styrene-based compound and the (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 80 mass % or more, more preferably 90 mass % or more, even more preferably 95 mass % or more, and even more preferably 100 mass %.

[0028] Resin A1 preferably has a constitutional unit derived from a bireactive monomer bonded via a covalent bond to a polyester resin segment and an addition polymerization resin segment. The term "structural unit derived from a bireactive monomer" refers to a unit formed by reaction of a functional group and an addition polymerizable group of a bireactive monomer. An example of the addition polymerizable group is a carbon-carbon unsaturated bond (ethylenically unsaturated bond). Examples of the bireactive monomer include addition polymerizable monomers having at least one functional group selected from a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, addition polymerizable monomers having at least one functional group selected from a hydroxyl group and a carboxyl group are preferred, and addition polymerizable monomers having a carboxyl group are more preferred. Examples of the addition polymerizable monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, from the viewpoint of reactivity in both the polycondensation reaction and the addition polymerization reaction, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred. When the bireactive monomer is an addition polymerizable monomer having a carboxy group, the amount of the constitutional units derived from the bireactive monomer is preferably 1 molar part or more, more preferably 5 molar parts or more, even more preferably 8 molar parts or more, and is preferably 30 molar parts or less, more preferably 25 molar parts or less, even more preferably 20 molar parts or less, relative to 100 molar parts of the alcohol component of the polyester resin segment of Resin A1.

[0029] The content of the polyester resin segment in the resin A1 is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, and preferably 95% by mass or less, more preferably 85% by mass or less, even more preferably 75% by mass or less, even more preferably 65% ​​by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment. The constitutional unit derived from the bireactive monomer is defined as a polyester resin segment.

[0030] The content of the addition polymerization resin segment in the resin A1 is preferably 5 mass% or more, more preferably 15 mass% or more, even more preferably 25 mass% or more, even more preferably 35 mass% or more, and is preferably 60 mass% or less, more preferably 50 mass% or less, even more preferably 45 mass% or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment.

[0031] The amount of the structural units derived from the bireactive monomer in the resin A1 is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, even more preferably 0.8 mass% or more, and is preferably 10 mass% or less, more preferably 7 mass% or less, even more preferably 4 mass% or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment.

[0032] The above amount is calculated based on the ratio of the amounts of the polyester resin segment, the raw material monomer for the addition polymerization resin segment, the bireactive monomer, and the radical polymerization initiator, and the mass of the polyester resin segment, etc. is based on the mass excluding the mass of water generated by polycondensation. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is calculated by including it in the addition polymerization resin segment.

[0033] (Manufacturing method of resin A1) Resin A1 may be produced, for example, by a method including step A of polycondensing an alcohol component and a carboxylic acid component. When resin A1 is a composite resin, it may be produced by a method including step A and step B of addition polymerizing raw material monomers of the addition polymerization resin segment and a bireactive monomer. Step B may be carried out after step A, step B may be carried out after step A, or step A and step B may be carried out simultaneously. In step A, a part of the carboxylic acid component is subjected to a polycondensation reaction, and then step B is carried out, and thereafter the remainder of the carboxylic acid component is added to the polymerization system to further proceed with the polycondensation reaction of step A and the polycondensation reaction with the carboxy group of the bireactive monomer or the constitutional unit derived from the bireactive monomer.

[0034] In step A, if necessary, polycondensation may be performed using an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, titanium diisopropoxybis(triethanolaminate) in an amount of 0.01 part by mass or more and 5 parts by mass or less per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component, and an esterification promoter such as gallic acid (same as 3,4,5-trihydroxybenzoic acid) in an amount of 0.001 part by mass or more and 0.5 part by mass or less per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. In addition, when a monomer having an unsaturated bond such as fumaric acid is used in the polycondensation reaction, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. An example of the radical polymerization inhibitor is 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, even more preferably 180° C. or higher, and is preferably 260° C. or lower, more preferably 250° C. or lower.

[0035] Examples of the radical polymerization initiator for the addition polymerization in step B include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the radical polymerization initiator used is preferably 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the raw material monomer of the addition polymerization resin segment. The temperature of the addition polymerization is preferably 110° C. or higher, more preferably 130° C. or higher, and preferably 230° C. or lower, more preferably 220° C. or lower, and further preferably 210° C. or lower.

[0036] (Physical properties of resin A1) The softening point of Resin A1 is preferably 70° C. or higher, more preferably 80° C. or higher, and even more preferably 90° C. or higher, and is preferably 130° C. or lower, more preferably 120° C. or lower, and even more preferably 110° C. or lower. The glass transition temperature of resin A1 is preferably 30° C. or higher, more preferably 40° C. or higher, and even more preferably 50° C. or higher, and is preferably 80° C. or lower, more preferably 70° C. or lower, and even more preferably 60° C. or lower.

[0037] The acid value of Resin A1 is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 25 mgKOH / g or less. The softening point, glass transition temperature, and acid value of Resin A1 can be appropriately adjusted by the type and amount of raw material monomer used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the methods described in the examples. When two or more kinds of resins A1 are used in combination, it is preferable that the softening point, glass transition temperature and acid value of the mixture obtained are each within the above-mentioned ranges.

[0038] [Crystalline resin C (resin C)] In the present invention, the resin particles may contain a crystalline resin C (hereinafter, also referred to as "resin C") in addition to the amorphous resin A. As the resin C, a crystalline polyester resin is preferable. For crystalline polyester resins, see JP2019-152855A.

[0039] When the resin particles contain resin C, the mass ratio of resin C to resin A (resin C / resin A) is preferably 1 / 99 or more, more preferably 3 / 97 or more, even more preferably 5 / 95 or more, and preferably 50 / 50 or less, more preferably 40 / 60 or less, even more preferably 30 / 70 or less.

[0040] In the resin component of the toner, the total content of resin A and resin C is preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less, preferably 98% by mass or less.

[0041] [Method for producing resin particles] As the resin particles, it is preferable to use resin particles X containing resin A. When the resin particles further contain resin C, any of resin particles X containing resin A, resin particles Y containing resin C, and resin particles XY containing resin A and resin C in the same particle may be used, but it is preferable to use resin particles X containing resin A and resin particles Y containing resin C. In the following description, resin particles X containing resin A therein will be described.

[0042] The dispersion of resin particles X can be obtained by dispersing resin A in an aqueous medium. The aqueous medium is preferably one containing water as a main component, and from the viewpoint of improving the dispersion stability of the dispersion liquid of the resin particles and from the viewpoint of environmental friendliness, the content of water in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, and even more preferably 100% by mass. Deionized water or distilled water is preferable as the water. Examples of components other than water that can be contained in the aqueous medium include organic solvents that dissolve in water, such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having a total carbon number of 3 to 5, such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran. Among these, methyl ethyl ketone is preferable.

[0043] The dispersion can be carried out by a known method, but is preferably carried out by a phase inversion emulsification method, for example, a method in which an aqueous medium is added to an organic solvent solution of resin A or a molten resin A to carry out phase inversion emulsification.

[0044] The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin A, and examples thereof include methyl ethyl ketone. It is preferable to add a neutralizing agent to the organic solvent solution of resin A. Examples of the neutralizing agent include basic substances. Examples of the basic substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. The neutralization degree of the resin A contained in the resin particles X is preferably 10 mol % or more, more preferably 20 mol % or more, even more preferably 30 mol % or more, even more preferably 40 mol % or more, and is preferably 100 mol % or less, more preferably 80 mol % or less, even more preferably 70 mol % or less. The degree of neutralization of the resin A contained in the resin particles X can be calculated by the following formula. Degree of neutralization (mol%)=[{weight of neutralizing agent added (g) / equivalent weight of neutralizing agent} / {weighted average acid value of resin A constituting resin particle X (mgKOH / g)×weight of resin A constituting resin particle X (g)} / (56×1000)]×100

[0045] The phase inversion emulsification is carried out by gradually adding an aqueous medium to a solution of resin A in an organic solvent or a molten resin A while stirring the solution. From the viewpoint of improving the dispersion stability of the resin particles X, the temperature of the organic solvent solution when the aqueous medium is added is preferably not less than the glass transition temperature of the resin A constituting the resin particles X, more preferably not less than 50° C., even more preferably not less than 60° C., even more preferably not less than 70° C., and is preferably not more than 100° C., more preferably not more than 90° C., even more preferably not more than 80° C.

[0046] After the phase inversion emulsification, if necessary, the organic solvent may be removed from the obtained dispersion by distillation, etc. In this case, the amount of the remaining organic solvent in the dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass.

[0047] Volume median particle size D of resin particles X in the dispersion 50From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the particle size is preferably 0.05 μm or more, more preferably 0.08 μm or more, and is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the CV value of the resin particles X in the dispersion is preferably 20% or more, more preferably 25% or more, and is preferably 40% or less, more preferably 35% or less. Volume median particle size D 50 The CV value is determined by the method described in the Examples below. Both the resin particles Y containing the resin C and the resin particles XY containing the resin A and the resin C can be produced in accordance with the above-mentioned method. 50 The preferred range of the CV value is the same as that described above.

[0048] <Colorant particles> From the viewpoint of obtaining a toner that can produce a printed matter with high image density and dot reproducibility, the colorant particles are obtained by a process of mixing a particle containing a colorant, an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, and a monofunctional compound having one functional group reactive with a carboxy group in the molecule. The colorant particles, for example, have an addition polymer on the surface of the colorant, preferably the surface of the colorant is coated with the addition polymer, and a part of the carboxy group of the addition polymer is bonded to the monofunctional compound having one reactive functional group in the molecule via a covalent bond.

[0049] [Coloring Agent] As the colorant, all of the dyes and pigments used as toner colorants can be used, and examples thereof include carbon black, phthalocyanine blue (e.g., CI 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, monoazo yellow (e.g., CI Pigment Yellow 74), and disazo yellow. The toner may be either a black toner or a color toner other than black. The colorants may be used alone or in combination of two or more kinds.

[0050] [Addition polymer] The addition polymer is an addition polymer of raw material monomers including an addition polymerizable monomer a having an aromatic group (hereinafter also simply referred to as "monomer a") and an addition polymerizable monomer b having a carboxy group (hereinafter also simply referred to as "monomer b") from the viewpoint of obtaining a toner that can provide a printed matter with high image density and dot reproducibility. From the viewpoint of further improving the image density and dot reproducibility of the printed matter, the addition polymer preferably contains a constituent unit derived from the addition polymerizable monomer a having an aromatic group in the main chain. The raw material monomers for the addition polymer preferably further contain, in addition to monomer a and monomer b, at least one selected from addition polymerizable monomer c having a polyalkylene oxide group (hereinafter also simply referred to as "monomer c") or macromonomer d (hereinafter also simply referred to as "monomer d").

[0051] The molecular weight of monomer a is preferably less than 1,000, more preferably 800 or less, more preferably 500 or less, more preferably 300 or less, and preferably 80 or more, more preferably 90 or more, more preferably 100 or more. Monomer a is preferably non-ionic. Examples of the monomer a include a styrene-based compound a-1 and an aromatic group-containing (meth)acrylate a-2. The styrene-based compound a-1 may be, for example, substituted or unsubstituted styrene. Examples of the substituent substituted on styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfo group, or a salt thereof. The molecular weight of the styrene-based compound a-1 is preferably less than 1,000, more preferably 800 or less, even more preferably 500 or less, even more preferably 300 or less, and preferably 80 or more, more preferably 90 or more, even more preferably 100 or more. Examples of the styrene-based compound a-1 include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid or a salt thereof. Among these, styrene and α-methylstyrene are preferred, and styrene is more preferred. From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the amount of the styrene-based compound a-1 is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and is preferably 98% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, even more preferably 75% by mass or less, in the raw material monomers of the addition polymer.

[0052] An example of the aromatic group-containing (meth)acrylate a-2 is benzyl (meth)acrylate.

[0053] From the viewpoint of obtaining a toner that can give printed matter with high image density and dot reproducibility, the amount of the addition polymerizable monomer a having an aromatic group is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and is preferably 98% by mass or less, more preferably 90% by mass or less, even more preferably 80% by mass or less, even more preferably 75% by mass or less, in the raw monomers of the addition polymer.

[0054] Examples of the monomer b include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, and 2-methacryloyloxymethylsuccinic acid. Among these, (meth)acrylic acid is preferred from the viewpoint of improving the dispersion stability of colorant particles in an aqueous medium. The content of monomer b in the raw material monomers of the addition polymer is preferably 2 mass% or more, more preferably 5 mass% or more, even more preferably 10 mass% or more, and preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 35 mass% or less.

[0055] The average number of moles of alkylene oxide groups added in monomer c is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, and is preferably 30 or less, more preferably 20 or less, even more preferably 15 or less. Monomer c is preferably non-ionic. Examples of monomer c include polyalkylene glycol (meth)acrylates such as polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate; alkoxy polyalkylene glycol (meth)acrylates such as methoxy polyethylene glycol (meth)acrylate; and aryloxy polyalkylene glycol (meth)acrylates such as phenoxy (ethylene glycol-propylene glycol copolymer) (meth)acrylate. When monomer c is contained, the amount of monomer c in the raw material monomers of the addition polymer is preferably 3 mass% or more, more preferably 10 mass% or more, even more preferably 20 mass% or more, and preferably 50 mass% or less, more preferably 40 mass% or less, even more preferably 30 mass% or less.

[0056] Examples of the monomer d include a styrene-based compound polymer having an addition polymerizable functional group at one end (hereinafter, also referred to as a "styrene-based macromonomer"). Examples of the addition polymerizable functional group include a vinyl group, an allyl group, and a (meth)acryloyl group. Among these, a (meth)acryloyl group is preferred. In the monomer d, the styrene-based compound is preferably styrene. The number average molecular weight of the monomer d is preferably 1,000 to 10,000. The number average molecular weight is measured by gel permeation chromatography using chloroform containing 1 mmol / L dodecyldimethylamine as a solvent and polystyrene as a standard substance. Commercially available styrene macromonomers include, for example, "AS-6", "AS-6S", "AN-6", "AN-6S", "HS-6", and "HS-6S" (all manufactured by Toagosei Co., Ltd.). When monomer d is contained, the amount of monomer d in the raw material monomers of the addition polymer is preferably 3 mass% or more, more preferably 6 mass% or more, even more preferably 10 mass% or more, and preferably 30 mass% or less, more preferably 25 mass% or less, even more preferably 20 mass% or less.

[0057] Furthermore, the raw material monomers of the addition polymer may contain addition polymerizable monomers (other monomers) other than the monomers a to d. Examples of the other monomers include alkyl (meth)acrylates having an alkyl group with a carbon number of 1 to 22 (preferably 6 to 18). A specific example is stearyl (meth)acrylate. When other monomers are contained, the amount of the other monomers in the raw material monomers of the addition polymer is preferably 70 mass % or less, more preferably 60 mass % or less, and even more preferably 50 mass % or less.

[0058] From the viewpoint of obtaining a toner that can give printed matter with high image density and dot reproducibility, the weight average molecular weight of the addition polymer is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 10,000 or more, and is preferably 200,000 or less, more preferably 150,000 or less, even more preferably 100,000 or less, even more preferably 70,000 or less. The weight average molecular weight can be measured by the method described in the Examples.

[0059] The addition polymer can be produced, for example, by copolymerizing raw material monomers by a known polymerization method, such as a solution polymerization method in which raw material monomers are polymerized by heating in a solvent together with a polymerization initiator, a polymerization chain transfer agent, and the like. Examples of the polymerization initiator include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the polymerization initiator to be added is not particularly limited, but from the viewpoint of promoting the polymerization reaction and suppressing side reactions, the amount is preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, relative to 100 parts by mass of the raw material monomer. Examples of the polymerization chain transfer agent include mercaptans such as 2-mercaptoethanol, 2-mercaptopropionic acid, and 3-mercaptopropionic acid. The amount of the polymerization chain transfer agent added is not particularly limited, but is preferably 0.01 part by mass or more, more preferably 0.03 part by mass or more, even more preferably 0.1 part by mass or more, and is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, relative to 100 parts by mass of the raw material monomer. After the polymerization reaction is completed, the produced polymer may be isolated and purified by a known method such as reprecipitation from the reaction solution or distillation of the solvent.

[0060] In the colorant particles, the mass ratio of the colorant to the addition polymer (colorant / addition polymer) is, from the viewpoint of obtaining a toner which can give printed matter with high image density and dot reproducibility, preferably 60 / 40 or more, more preferably 70 / 30 or more, even more preferably 75 / 25 or more, and is preferably 98 / 2 or less, more preferably 97 / 3 or less, even more preferably 96 / 4 or less.

[0061] [Monofunctional compounds having one functional group reactive with a carboxy group in the molecule] A monofunctional compound having one functional group reactive with a carboxy group in the molecule (hereinafter also simply referred to as a "monofunctional compound") bonds with the carboxy group of the addition polymer present on the particle surface in the process of mixing with a particle containing a colorant and an addition polymer. Therefore, the functional group reactive with a carboxy group (hereinafter also referred to as a "carboxy group reactive group") is preferably present near the end of the monofunctional compound, more preferably at the end, and even more preferably no other substituent is present near the functional group.

[0062] The carboxyl group-reactive group possessed by the monofunctional compound may be any group that reacts with a carboxyl group. From the viewpoints of reactivity, availability, and stability, an oxazoline group or an epoxy group is preferred, and an epoxy group is more preferred.

[0063] Examples of monofunctional compounds having one oxazoline group in the molecule include linear or branched alkyl-substituted oxazolines such as 2-methyl-2-oxazoline and 2-n-butyl-2-oxazoline; and substituted or unsubstituted aryloxazolines such as 2-phenyl-2-oxazoline.

[0064] Examples of monofunctional compounds having one epoxy group in the molecule include linear or branched alkyl-substituted epoxides such as 1,2-epoxydodecane and 1,2-epoxyoctane; substituted or unsubstituted aryl-substituted epoxides such as styrene oxide; linear or branched alkyl glycidyl ethers such as dodecyl glycidyl ether and 2-ethylhexyl glycidyl ether; substituted or unsubstituted aryl glycidyl ethers such as phenyl glycidyl ether and p-tert-butylphenyl glycidyl ether; alkoxy polyalkylene glycol glycidyl ethers such as methoxy polyethylene glycol glycidyl ether and lauryloxy polyethylene glycol glycidyl ether; and aryloxy polyalkylene glycol glycidyl ethers such as phenoxy polyethylene glycol glycidyl ether. Examples of monofunctional compounds having one epoxy group in the molecule include the "Denacol series" manufactured by Nagase ChemteX Corporation.

[0065] [Method for producing a dispersion of colorant particles] The method for producing a dispersion of colorant particles includes a step of mixing particles containing a colorant and an addition polymer with a monofunctional compound. This step is carried out before step 1, that is, before the step of aggregating the resin particles and the colorant particles in an aqueous medium to obtain aggregated particles.

[0066] (Method for producing a dispersion of particles containing a colorant and an addition polymer) The particles containing a colorant and an addition polymer can be obtained, for example, by mixing a colorant and an addition polymer. There is no particular limitation on the method for producing a dispersion of particles containing a colorant and an addition polymer. 50 It is only necessary to control the colorant particles to obtain the above colorant particles.

[0067] The method for producing a dispersion of particles containing a colorant and an addition polymer preferably includes the steps of: Step a: mixing an addition polymer with an organic solvent, optionally mixing a neutralizing agent therewith, and then mixing an aqueous medium therewith to obtain a dispersion of the addition polymer; and Step b: A step of dispersing the dispersion obtained in step a and a colorant to obtain a dispersion of particles containing a colorant and an addition polymer. It is a method having the following structure. By including an organic solvent, the colorant and the addition polymer dissolve in the organic solvent, and the addition polymer is more easily adsorbed to the colorant, thereby further enhancing the dispersibility of the colorant. Furthermore, step b is preferably a step of dispersing the dispersion obtained in step a and a colorant using a bead mill or a homogenizer to obtain a dispersion of particles containing the colorant and the addition polymer.

[0068] In step a, it is preferable to first mix and dissolve the addition polymer in an organic solvent. It is more preferable that the addition polymer is dissolved in the organic solvent by mixing the addition polymer with an organic solvent. Examples of the organic solvent used here include alkyl alcohols having 1 to 3 carbon atoms, dialkyl ketones having a total of 3 to 5 carbon atoms, and cyclic ethers. Among these, dialkyl ketones having a total of 3 to 5 carbon atoms are preferred, and methyl ethyl ketone is more preferred. When the addition polymer is synthesized by solution polymerization, the solvent used in the polymerization may be used as is.

[0069] Subsequently, an aqueous medium is mixed with the mixture of the addition polymer and the organic solvent to obtain a dispersion of the addition polymer. The aqueous medium is preferably one containing water as a main component, and from the viewpoint of improving the dispersion stability of the dispersion liquid of the addition polymer particles and from the viewpoint of environmental friendliness, the content of water in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, even more preferably 100% by mass. Deionized water or distilled water is preferable as the water. Examples of components other than water that can be contained in the aqueous medium include organic solvents that dissolve in water, such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having a total carbon number of 3 to 5, such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran.

[0070] The neutralizing agent may, for example, be a basic substance, such as an alkali metal hydroxide, such as sodium hydroxide, potassium hydroxide, or a nitrogen-containing basic substance, such as ammonia, trimethylamine, or diethanolamine. The degree of neutralization of the addition polymer is preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 75 mol % or more, and preferably 100 mol % or less, more preferably 98 mol % or less, even more preferably 95 mol % or less. The degree of neutralization of the addition polymer can be determined by the following formula. Degree of neutralization (mol%)=[{weight (g) of neutralizing agent added / equivalent weight of neutralizing agent} / {weight ratio of addition polymerizable monomer having an acidic group constituting the addition polymer×weight (g) of the addition polymer / molecular weight of addition polymerizable monomer having an acidic group}]×100 In step a, the device used for mixing may be, for example, a mixer / stirrer equipped with an anchor blade, a disperser blade, or the like. The temperature during mixing is preferably 0° C. or higher, more preferably 10° C. or higher, and is preferably 40° C. or lower, more preferably 30° C. or lower, and further preferably 25° C. or lower. The mixing time is preferably 5 minutes or more, more preferably 8 minutes or more, and preferably 3 hours or less, more preferably 1 hour or less, and even more preferably 0.5 hour or less.

[0071] In step b, the dispersion liquid obtained in step a and a colorant are subjected to a dispersion treatment to obtain a dispersion liquid of particles containing the colorant and the addition polymer. Note that the dispersion treatment is preferably performed after mixing the dispersion liquid obtained in step a and the colorant. In the step b, the mass ratio of the colorant to the addition polymer [colorant / addition polymer] is as described above.

[0072] Examples of the device used in step b include kneaders such as roll mills and kneaders, homogenizers such as Microfluidizer (manufactured by Microfluidics), and media-type dispersers such as paint shakers and bead mills. One or more of these devices may be used. Among these, from the viewpoint of reducing the particle size of the pigment, bead mills and homogenizers are preferred, and homogenizers are more preferred. In the step b, when a homogenizer is used, the treatment pressure is preferably 60 MPa or more, more preferably 100 MPa or more, even more preferably 130 MPa or more, and preferably 270 MPa or less, more preferably 200 MPa or less, even more preferably 180 MPa or less. The number of passes is preferably 5 or more, more preferably 7 or more, and even more preferably 10 or more, and is preferably 30 or less, and more preferably 20 or less.

[0073] It is preferable to remove the organic solvent from the obtained dispersion of particles containing the colorant and the addition polymer. It is also preferable to filter the dispersion of particles containing the colorant and the addition polymer through a wire mesh or the like to remove coarse particles and the like. In addition, various additives such as organic solvents, preservatives, and antifungal agents may be added to the dispersion of particles containing a colorant and an addition polymer. In addition, an aqueous medium may be added appropriately so as to obtain a desired solid content concentration.

[0074] In the dispersion of particles containing a colorant and an addition polymer, the colorant is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less. The solids concentration of the dispersion of particles containing a colorant and an addition polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, from the viewpoint of reactivity with the monofunctional compound, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, from the viewpoint of the stability of the dispersion.

[0075] Volume median particle size D of particles containing colorant and addition polymer 50 From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the particle size is preferably 0.05 μm or more, more preferably 0.07 μm or more, even more preferably 0.08 μm or more, and is preferably 0.3 μm or less, more preferably 0.2 μm or less, even more preferably 0.15 μm or less. From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the CV value of the particles containing a colorant and an addition polymer is preferably 10% or more, more preferably 15% or more, and is preferably 40% or less, more preferably 30% or less. Volume median particle size D of particles containing colorant and addition polymer 50 and CV values ​​are measured by the methods in the Examples.

[0076] (Method for producing a dispersion of colorant particles) The colorant particles are obtained by a process of mixing particles containing a colorant and an addition polymer with a monofunctional compound. There is no particular limitation on the method for producing the dispersion of colorant particles, as long as the carboxy group of the addition polymer contained in the particles containing the colorant and the addition polymer reacts with the monofunctional compound via the carboxy group-reactive group.

[0077] The step of mixing the particles containing a colorant and an addition polymer with a monofunctional compound is preferably Step c: mixing the dispersion of particles containing the colorant and the addition polymer obtained in step b with a monofunctional compound. It is a method having the following structure.

[0078] From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the amount of the monofunctional compound mixed is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, even more preferably 2 parts by mass or more, and is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, relative to 100 parts by mass of the particles containing a colorant and an addition polymer. In step c, the ratio of the number of moles of carboxy reactive groups in the monofunctional compound to the number of moles of carboxy groups in the addition polymer contained in the particles containing a colorant and an addition polymer (carboxy reactive groups in monofunctional compound / carboxy groups in addition polymer) is preferably 0.20 or more, more preferably 0.30 or more, even more preferably 0.40 or more, even more preferably 0.45 or more, and is preferably 0.80 or less, more preferably 0.70 or less, even more preferably 0.60 or less, even more preferably 0.55 or less.

[0079] It is preferable to have a step of heating the particles containing the colorant and the addition polymer mixed with the monofunctional compound after mixing the particles containing the colorant and the addition polymer with the monofunctional compound. The heating may be performed during mixing or after mixing, and is not particularly limited. The temperature during heating is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 70°C or higher from the viewpoint of promoting the reaction between the carboxy group of the colorant particles and the functional group reactive with the carboxy group of the monofunctional compound, and is preferably 95°C or lower, more preferably 90°C or lower, and even more preferably 85°C or lower from the viewpoint of suppressing side reactions. The mixing time of the particles containing a colorant and an addition polymer with the monofunctional compound depends on the temperature during mixing, but from the viewpoint of sufficient reaction between the carboxy group of the particles containing a colorant and an addition polymer and the functional group reactive with the carboxy group of the monofunctional compound, and from the viewpoint of productivity, is preferably 30 minutes or more, more preferably 1 hour or more, even more preferably 2 hours or more, and is preferably 12 hours or less, more preferably 6 hours or less, even more preferably 4 hours or less. During the above heating, it is preferable to heat while mixing.

[0080] In the dispersion of colorant particles, the colorant is preferably 5% by mass or more, more preferably 8% by mass or more, even more preferably 12% by mass or more, and preferably 45% by mass or less, more preferably 35% by mass or less, even more preferably 25% by mass or less. The solids concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less.

[0081] Volume median particle size D of colorant particles 50From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the particle size is preferably 0.05 μm or more, more preferably 0.07 μm or more, even more preferably 0.08 μm or more, and is preferably 0.3 μm or less, more preferably 0.2 μm or less, even more preferably 0.15 μm or less. From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the CV value of the colorant particles is preferably 10% or more, more preferably 15% or more, and is preferably 40% or less, more preferably 30% or less.

[0082] From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the amount of colorant particles is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, per 100 parts by mass of resin particles.

[0083] In the present invention, the resin particles and the colorant particles are aggregated in step 1. In addition to the above components, it is preferable to contain release agent particles. That is, it is preferable that the release agent is added in the form of release agent particles, and aggregates together with the resin particles and the colorant particles.

[0084] [Release Agent] Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene-polyethylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, or oxides thereof; ester waxes such as carnauba wax, montan wax, or deacidified waxes thereof, and fatty acid ester wax; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. These may be used alone or in combination of two or more. Among these, the release agent is preferably a hydrocarbon wax or an ester wax, and more preferably a hydrocarbon wax.

[0085] The melting point of the release agent is preferably 60° C. or higher, more preferably 70° C. or higher, and is preferably 160° C. or lower, more preferably 130° C. or lower, and further preferably 100° C. or lower.

[0086] The amount of the release agent in the toner is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 5% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less.

[0087] (Dispersion of release agent particles) The release agent is preferably mixed as a dispersion of release agent particles with a resin particle dispersion and a colorant particle dispersion, and then aggregated. The dispersion of release agent particles can be obtained using a surfactant, but is preferably obtained by mixing the release agent with resin particles S described below. By preparing the release agent particles using the release agent and resin particles S, the release agent particles are stabilized by the resin particles S, and it becomes possible to disperse the release agent in an aqueous medium without using a surfactant. It is considered that the dispersion of release agent particles has a structure in which a large number of resin particles S are attached to the surface of the release agent particles. The resin constituting the resin particles S in which the release agent is dispersed is preferably a polyester resin, and it is more preferable to use a composite resin D having a polyester resin segment and an addition polymerization resin segment. As the composite resin D, a resin similar to the composite resin listed in the above-mentioned resin A can be used. In addition, for the release agent particle dispersion and the composite resin D, reference is made to JP 2021-182045 A.

[0088] In step 1, the aggregation of the resin particles and the colorant particles in the aqueous medium may be carried out in the presence of other additives in addition to the release agent. As the aqueous medium, the aqueous medium shown in the method for producing resin particles can be used, and the preferred ranges thereof are also the same. Examples of other additives include charge control agents, magnetic powders, flow improvers, conductivity adjusters, reinforcing fillers such as fibrous substances, antioxidants, antiaging agents, and cleaning improvers.

[0089] [Surfactant] In step 1, when the dispersions of the individual particles are mixed to prepare a mixed dispersion, the process may be carried out in the presence of a surfactant in order to improve the dispersion stability of optional components such as the resin particles, colorant particles, and release agent particles added as necessary. Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. When a surfactant is used, the amount used, for each type of surfactant, is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, per 100 parts by mass of resin particles, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less.

[0090] The resin particle dispersion, the colorant particle dispersion, and the optional components are mixed by a conventional method. From the viewpoint of efficiently performing aggregation, it is preferable to add an aggregating agent to the mixed dispersion obtained by the mixing.

[0091] [Flocculant] Examples of the flocculant include cationic surfactants such as quaternary salts, organic flocculants such as polyethyleneimine, and inorganic flocculants. Examples of the inorganic flocculant include 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 divalent or higher metal complexes. From the viewpoint of improving the coagulation properties and obtaining uniformly coagulated particles, inorganic coagulants having a valence of 1 to 5 are preferred, inorganic metal salts having a valence of 1 to 2 and inorganic ammonium salts are more preferred, inorganic ammonium salts are even more preferred, and ammonium sulfate is even more preferred.

[0092] For example, 5 to 60 parts by mass of the aggregating agent is added to a mixed dispersion containing resin particles and colorant particles at 0° C. to 40° C., based on 100 parts by mass of the total amount of resin in the resin particles, to aggregate the resin particles and colorant particles in an aqueous medium, thereby obtaining aggregated particles. Furthermore, from the viewpoint of promoting aggregation, it is preferable to increase the temperature of the dispersion after adding the aggregating agent.

[0093] The aggregation may be stopped when the aggregated particles grow to a suitable particle size as toner particles. Examples of a method for stopping the aggregation include a method of cooling the dispersion, a method of adding an aggregation terminator, a method of diluting the dispersion, etc. From the viewpoint of reliably preventing unnecessary aggregation, a method of stopping the aggregation by adding an aggregation terminator is preferred.

[0094] [Aggregation Stopper] The aggregation terminator is preferably a surfactant, more preferably an anionic surfactant. Examples of the anionic surfactant include alkylbenzenesulfonate, alkyl sulfate, alkyl ether sulfate, polyoxyalkylene alkyl ether sulfate, etc. These may be used alone or in combination. The aggregation terminator may be added in the form of an aqueous solution. The amount of the aggregation terminator added is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the resin in the resin particles, from the viewpoint of reliably preventing unnecessary aggregation, and is preferably 60 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, from the viewpoint of reducing residue in the toner.

[0095] Volume median particle size of agglomerated particles D 50 is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 9 μm or less, even more preferably 8 μm or less. 50 can be determined by the method described in the Examples below.

[0096] In the present invention, after step 1 and before step 2, a step (step 1') may be included in which resin particles X' containing an amorphous resin (preferably an amorphous polyester-based resin) are adhered to the aggregated particles (aggregated particles 1) obtained in step 1 to obtain aggregated particles 2. Here, the above-mentioned resin A1 is exemplified as the amorphous polyester resin used for the resin particles X'. The resin particles X' can be obtained by the same method as the resin particles X described above. Furthermore, when the toner manufacturing method includes step 1', it is preferable to terminate the aggregation of aggregated particles 2 in step 1' when the aggregated particles 2 have grown to an appropriate particle size as toner particles, and a method of terminating the aggregation by adding the above-mentioned aggregation terminator is preferable.

[0097] ≪Process 2≫ In step 2, for example, the aggregated particles are fused in an aqueous medium. By fusion, the particles contained in the aggregated particles are fused together to obtain fused particles. From the viewpoint of improving the fusibility of the aggregated particles, the fusion is performed by maintaining the particles at a temperature equal to or higher than the glass transition temperature of the resin having the highest glass transition temperature among the resins contained in the resin particles. The holding temperature when fusing the aggregated particles is, from the viewpoint of improving the fusing property of the aggregated particles and improving the productivity of the toner, preferably at least 5° C. higher than the glass transition temperature of the resin, more preferably at least 10° C. higher, and even more preferably at least 15° C. higher, and is preferably not higher than 35° C. higher, more preferably not higher than 30° C. higher, and even more preferably not higher than 25° C. higher than the glass transition temperature of the resin. In this case, the time for which the resin is maintained at a temperature equal to or higher than the glass transition temperature is preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and is preferably 240 minutes or less, more preferably 180 minutes or less, even more preferably 120 minutes or less, even more preferably 90 minutes or less. It is preferable to maintain the temperature at the above temperature until the desired circularity is achieved.

[0098] The volume median particle size D of the fused particles obtained by fusion50 is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 9 μm or less, even more preferably 8 μm or less.

[0099] The circularity of the fused particles obtained by fusion is preferably 0.955 or more, more preferably 0.960 or more, and is preferably 0.990 or less, more preferably 0.985 or less, and further preferably 0.980 or less. The fusion is preferably terminated after the above-mentioned preferred circularity is reached. The circularity is measured by the method described in the Examples.

[0100] <Post-processing process> A post-treatment step may be performed after step 2, and toner particles are obtained by isolating the fused particles. Since the fused particles obtained in step 2 are present in an aqueous medium, it is preferable to first perform solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used. It is preferable to wash the solid-liquid separation product. In this case, it is preferable to remove the surfactant added, and therefore it is preferable to wash the product with an aqueous medium at a temperature below the cloud point of the surfactant. It is preferable to wash the product several times. Next, drying is preferably performed. Examples of the drying method include vacuum low-temperature drying, vibration-type fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0101] [Toner particles] Volume median particle size of toner particles D 50 From the viewpoint of obtaining a toner that can produce printed matter with high image density and dot reproducibility, the particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 9 μm or less, even more preferably 8 μm or less. Volume median particle size of toner particles D 50 can be measured by the method described in the Examples.

[0102] [Toner for developing electrostatic images] The toner comprises toner particles. The toner particles can be used as they are, but it is preferable to use the toner after adding a fluidizing agent or the like as an external additive to the surface of the toner particles.

[0103] [External additives] Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. The external additive may be used alone or in combination with two or more kinds. In addition, two or more kinds of hydrophobic silica having different particle sizes may be used. When the toner particles are surface-treated using an external additive, the amount of the external additive added is, relative to 100 parts by mass of the toner particles, preferably 1 part by mass or more, more preferably 2 parts by mass or more, even 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, even more preferably 4 parts by mass or less.

[0104] Toners are used for developing electrostatic images in electrophotographic printing. The toners can be used, for example, as one-component developers or mixed with a carrier to form two-component developers. EXAMPLES

[0105] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Each property value was measured and evaluated by the following methods. In the notation such as "alkylene oxide (X)", the number X in parentheses means the average number of moles of alkylene oxide added. Furthermore, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

[0106] [Measurement method]

[0107] [Softening point, crystallinity index, and glass transition temperature of resin] (1) Softening point Using a flow tester "CFT-500D" (Shimadzu Corporation), 1 g of sample was heated at a temperature increase rate of 6°C / min, while applying a load of 1.96 MPa with the plunger, and extruding the sample 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 sample was weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The sample was then left to stand for 1 minute, and then heated to 180°C at a rate of 10°C / min to measure the amount of heat. The temperature of the peak with the largest peak area among the observed endothermic peaks was taken as the endothermic maximum peak temperature (1), and the crystallinity index was calculated by (softening point (°C)) / (endothermic maximum peak temperature (1) (°C)). (3) 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 rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the amount of heat was measured. The temperature of the peak with the largest peak area among the observed endothermic peaks was taken as the endothermic maximum peak temperature (2). The intersection temperature of the extension of the baseline below the endothermic maximum peak temperature (2) and the tangent line showing the maximum slope from the rising part of the peak to the apex of the peak was taken as the glass transition temperature.

[0108] [Acid value of resin] The measurement was performed in accordance with JIS K0070, except that the measurement solvent was a mixed solvent of acetone and toluene (acetone:toluene=1:1 (volume ratio)).

[0109] [Melting point of release agent] Using a differential scanning calorimeter "Q-20" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, the calorific value was measured, and the maximum endothermic peak temperature was taken as the melting point.

[0110] [Volume median particle diameter D of resin particles, colorant particles, and release agent particles 50 and CV value] (1) Measuring device: Laser diffraction type particle size measuring device "LA-920" (manufactured by Horiba Ltd.) (2) Measurement conditions: Put a thoroughly stirred sample dispersion into the measurement cell, add distilled water, and measure the volume median particle size D at a concentration where the absorbance is in the appropriate range. 50 The volume average particle diameter Dv was measured, and the CV value was calculated according to the following formula. CV value (%) = (Standard deviation of particle size distribution / Volume average particle size Dv) x 100

[0111] [Solid Content Concentration of Aqueous Dispersion of Resin Particles, Aqueous Dispersion of Release Agent Particles, and Colorant Dispersion] Using an infrared moisture meter "FD-230" (Kett Electric Laboratory Co., Ltd.), the moisture content (mass%) of 5 g of the measurement sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes / fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0112] [Volume median particle diameter of agglomerated particles D 50 〕 Volume median particle size of agglomerated particles D 50 was measured as follows: Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50μm Analysis software: "Multisizer (registered trademark) III version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured again, and the volume median particle size D is calculated from the particle size distribution. 50 asked for.

[0113] [Circularity of fused particles] The circularity of the fused particles was measured under the following conditions. Measurement equipment: Flow-type particle image analyzer "FPIA-3000" (Sysmex Corporation) Preparation of dispersion: A dispersion of fused particles was prepared by diluting with deionized water to a solids concentration of 0.001 to 0.05% by mass. Measurement mode: HPF measurement mode

[0114] [Volume median particle size of toner particles D 50 〕 Volume median particle size of toner particles D 50 was measured as follows: The measuring instrument, aperture diameter, analysis software, and electrolyte are the volume median particle diameter D 50 The same as in the measurement was used. Dispersion liquid: Polyoxyethylene lauryl ether "EMULGEN 109P" (manufactured by Kao Corporation, HLB: 13.6) was dissolved in the above-mentioned electrolyte to obtain a dispersion liquid with a concentration of 5% by mass. Dispersion conditions: 10 mg of a toner measurement sample was added to 5 mL of the dispersion liquid, and dispersed for 1 minute using an ultrasonic disperser. Thereafter, 25 mL of electrolyte was added, and the mixture was further dispersed for 1 minute using an ultrasonic disperser to prepare a sample dispersion liquid. Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured and the volume median particle size D is calculated from the particle size distribution. 50 , and the volume ratio of toner particles having a particle size of 2 μm or less were determined.

[0115] [Evaluation method] [Image density of printed matter] Using a commercially available printer "Microline (registered trademark) 5400" (manufactured by Oki Electric Industry Co., Ltd.) on high-quality paper "J paper A4 size" (manufactured by Fujifilm Business Innovation Co., Ltd.), the amount of toner attached on the paper was 0.35 mg / cm 2 The solid image was output without being fixed. Next, the same printer was prepared with a modified temperature-variable fixing unit, the temperature of the fixing unit was set to 130° C., and the toner was fixed on A4 sheets in portrait orientation at a speed of 1.5 seconds per sheet to obtain a printout. Thirty sheets of high-quality paper "Excellent White Paper A4 size" (Oki Electric Industry Co., Ltd.) were placed under the print, and the reflected image density of the solid image part of the output print was measured using a colorimeter "SpectroEye" (GretagMacbeth, light irradiation conditions: standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard), and the values ​​measured at any 10 points on the image were averaged to obtain the image density. The higher the value, the better the image density.

[0116] [Dot reproducibility] A halftone image of 2 dots and 2 spaces was printed at a resolution of 1200 dpi on high-quality paper "J paper A4 size" (manufactured by Fujifilm Business Innovation Co., Ltd.) using a commercially available printer "Microline (registered trademark) 5400" (manufactured by Oki Electric Industry Co., Ltd.). This was visually evaluated on the following 5-point scale. The higher the number, the less toner scattering around the dot and the less white space within the dot, and the clearer the dot. 5: Almost no scattered toner was observed around the dots, the dots were very clear, and there were no blank spaces within the dots. 4: Although a small amount of scattered toner is observed around the dots, the dots are clear and there are no blank spaces within the dots. 3: Although scattered toner was observed around the dots and the dots were somewhat unclear, there was no white space within the dots. 2: Toner scattering was observed around the dots, making the dots somewhat unclear and blank spaces could also be seen within the dots. 1: Toner scattering around the dots is noticeable, making the dots unclear and the white space within the dots is also noticeable.

[0117] [Production of resin particles] [Production of amorphous polyester resin A1] Production Example A1 (Production of Resin A1-1) The raw material monomer (A) of polyester resin other than fumaric acid shown in Table 1, and esterification catalyst were placed in a 10L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube equipped with a fractionating tube through which hot water of 98 ° C. was passed, a stirrer, and a thermocouple. Under a nitrogen atmosphere, the reaction system was kept at 180 ° C. for 1 hour, then heated from 180 ° C. to 230 ° C. at 10 ° C. / h, and then held at 230 ° C. for 5 hours to perform polycondensation. After that, after cooling to 180 ° C., 5 g of fumaric acid and a radical polymerization inhibitor (4-tert-butylcatechol) were added to the reaction system, heated from 180 ° C. to 210 ° C. at 10 ° C. / h, and reacted at 210 ° C. for 1 hour. The reaction was continued at 210 ° C. and 10 kPa until the softening point shown in Table 1 was obtained. The physical properties are shown in Table 1.

[0118] Production Example A2 (Production of Resin A1-2) The raw material monomers (A) other than fumaric acid shown in Table 1 were placed in a 10L four-neck flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple, and the reaction system was heated to 160°C under a nitrogen atmosphere. Then, a mixture of the bireactive monomer, the raw material monomer (B), and a radical polymerization initiator (dibutyl peroxide) was dropped into the reaction system over 1 hour using a dropping funnel. After the dropping, the temperature was kept at 160°C and the addition polymerization reaction was matured for 1 hour, then the temperature was raised to 200°C and reacted for 1 hour under a reduced pressure of 8.0 kPa. The esterification catalyst and esterification promoter shown in Table 1 were then added to the reaction system, followed by polycondensation reaction at 235°C for 6 hours, and further reaction at 235°C and 8.0 kPa for 1 hour. After cooling to 180°C, fumaric acid and 5g of a radical polymerization inhibitor (4-tert-butylcatechol) were added to the reaction system, the temperature was raised from 180°C to 210°C at 10°C / h, and the reaction was carried out at 210°C for 1 hour, and the reaction was continued at 210°C and 10kPa until the softening point shown in Table 1 was reached, yielding Resin A1-2. The physical properties are shown in Table 1.

[0119] Production Example A3 (Production of Resin A1-3) The raw material monomer (A) other than trimellitic anhydride shown in Table 1 and the esterification catalyst were placed in a 10L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and the reaction system was heated to 235°C under a nitrogen atmosphere and reacted for 6 hours. After reacting for 1 hour under a reduced pressure of 8.0 kPa and further lowering the temperature to 210°C, trimellitic anhydride was added to the reaction system, reacted for 1 hour at 210°C, and reacted at 210°C and 40 kPa until the softening point shown in Table 1 was obtained. Resin A1-3 was obtained by reacting the physical properties in Table 1.

[0120] [Table 1]

[0121] [Production of Resin Particle Dispersion] Production Example X1 (Production of Resin Particle Dispersion X-1) In a 3 L vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 200 g of resin A1-1 and 200 g of methyl ethyl ketone were placed and dissolved for 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization with respect to the acid value of the resin was 60 mol%, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 200 r / min to cause phase inversion emulsification. While maintaining the temperature at 73°C, the methyl ethyl ketone was distilled off under reduced pressure to obtain a dispersion. Thereafter, while continuing to stir, the dispersion was cooled to 30°C, and deionized water was added so that the solid concentration was 20 mass%, to obtain resin particle dispersion X-1. The physical properties are shown in Table 2.

[0122] Production Examples X2 and 3 (Production of Resin Particle Dispersions X-2 and X-3) Resin particle dispersions X-2 and X-3 were obtained in the same manner as in Production Example X1, except that the resin shown in Table 2 was used instead of Resin A1-1.

[0123] [Table 2]

[0124] [Production of release agent particles] [Production of Composite Resin D] Manufacturing Example D1 (Manufacturing of Resin D-1) The inside of a 10L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple was replaced with nitrogen, and 4,313g of a propylene oxide (2.2) adduct of bisphenol A, 818g of terephthalic acid, 30g of tin (II) di(2-ethylhexanoate) and 3.0g of gallic acid were added, and the reaction system was heated to 235°C while stirring under a nitrogen atmosphere, and then maintained at 235°C for 5 hours, after which the pressure in the flask was reduced and maintained at 8kPa for 1 hour. After that, the pressure was returned to atmospheric pressure, and the temperature was cooled to 160°C, and while maintaining the temperature at 160°C, a mixture of 2,756g of styrene, 689g of stearyl methacrylate, 142g of acrylic acid and 413g of dibutyl peroxide was added dropwise to the reaction system over 3 hours. The reaction system was then held at 160°C for 30 minutes, then heated to 200°C, and the pressure in the flask was further reduced and held at 8kPa for 1 hour. After that, the pressure was returned to atmospheric pressure, and the mixture was cooled to 190°C, 727g of succinic acid was added, and the mixture was heated to 210°C at 10°C / hr, and then reacted at 4kPa until the desired softening point was reached, yielding Resin D-1. The physical properties are shown in Table 3.

[0125] [Table 3]

[0126] Production Example S1 (Production of Resin Particle Dispersion S-1) In a 3 L vessel equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 200 g of Resin D-1 and 200 g of methyl ethyl ketone were placed and dissolved for 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization with respect to the acid value of Resin D-1 was 60 mol %, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 280 r / min to cause phase inversion emulsification. While maintaining the temperature at 73°C, the methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while stirring at 280 r / min, the aqueous dispersion was cooled to 30°C, and deionized water was added so that the solids concentration was 20 mass%, to obtain resin particle dispersion S-1. Volume median particle diameter D of resin particles in resin particle dispersion S-1 50 The diameter was 0.90 μm and the CV value was 23%.

[0127] [Preparation of Release Agent Particle Dispersion] Production Example W1 (Production of Release Agent Particle Dispersion W-1) Into a 1 L beaker, 120 g of deionized water, 86 g of resin particle dispersion S-1, and 40 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 while melting and stirring to obtain a molten mixture. The obtained molten mixture was dispersed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while maintaining the temperature at 90 to 95°C, and then cooled to room temperature (20°C). Deionized water was added to the obtained dispersion to adjust the solid content to 20 mass%, thereby obtaining release agent particle dispersion W-1. The volume median particle diameter D of the release agent particles in release agent particle dispersion W-1 was 50 The thickness was 0.28 μm and the CV value was 20%.

[0128] Production Example W2 (Production of Release Agent Particle Dispersion W-2) A release agent particle dispersion W-2 was obtained in the same manner as in Production Example W1, except that the paraffin wax "HNP-9" was changed to Fischer-Tropsch wax "FNP-0090" (manufactured by Nippon Seiro Co., Ltd., melting point 90°C). 50 The diameter was 0.24 μm and the CV value was 20%.

[0129] [Production of colorant particles] [Production of Addition Polymer] Production Example E1 (Production of Addition Polymer E-1) A raw material monomer mixture was prepared by mixing 31 parts by mass of acrylic acid (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 59 parts by mass of styrene (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), and 10 parts by mass of α-methylstyrene (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.). Into a reaction vessel, 10 parts by mass of methyl ethyl ketone, 0.3 parts by mass of 2-mercaptopropionic acid as a polymerization chain transfer agent, and 10% by mass of the raw material monomer mixture were placed and mixed, and the atmosphere was thoroughly replaced with nitrogen gas. Meanwhile, the remaining raw material monomer mixture, 0.27 parts by mass of the polymerization chain transfer agent, 40 parts by mass of methyl ethyl ketone, and 1.1 parts by mass of an azo radical polymerization initiator (V-501; 4,4'-azobis(4-cyanovaleric acid) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were placed in a dropping funnel, and the monomer mixture in the reaction vessel was heated to 65°C while stirring under a nitrogen atmosphere, and the mixture in the dropping funnel was dropped over 3 hours. After 2 hours at 65°C from the end of the dropping, a solution in which 0.15 parts by mass of the polymerization initiator was dissolved in 2.5 parts by mass of methyl ethyl ketone was added, and the mixture was further aged at 65°C for 2 hours and at 70°C for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure drying to obtain an addition polymer E-1. The physical properties of the obtained addition polymer are shown in Table 4.

[0130] Production Example E2 (Synthesis of Addition Polymer E-2) A raw material monomer mixture was prepared by mixing 16 parts by mass of methacrylic acid (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 44 parts by mass of styrene (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.), 30 parts by mass (15 parts by mass as solids) of styrene macromonomer "AS-6S" (manufactured by Toagosei Co., Ltd., number average molecular weight 6,000, solids concentration 50% by mass), and 25 parts by mass of methoxypolyethylene glycol methacrylate "BLEMMER PME-200" (manufactured by NOF Corporation). Into a reaction vessel, 18 parts by mass of methyl ethyl ketone, 0.03 parts by mass of 2-mercaptoethanol as a polymerization chain transfer agent, and 10% by mass of the raw material monomer mixture were placed and mixed, and the atmosphere was thoroughly replaced with nitrogen gas. On the other hand, a mixture of the remaining 90% by mass (103.5 parts by mass) of the raw material monomer mixture, 0.27 parts by mass of the polymerization chain transfer agent, 42 parts by mass of methyl ethyl ketone, and 3 parts by mass of the polymerization initiator 2,2'-azobis(2,4-dimethylvaleronitrile) "V-65" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a dropping funnel, and the mixed solution in the reaction vessel was heated to 75°C while stirring under a nitrogen atmosphere, and the mixed solution in the dropping funnel was dropped over 3 hours. After 2 hours at 75°C from the end of the dropping, a solution in which 3 parts by mass of the polymerization initiator was dissolved in 5 parts by mass of methyl ethyl ketone was added, and the mixture was further aged at 75°C for 2 hours and at 80°C for 2 hours. Thereafter, methyl ethyl ketone was distilled off under reduced pressure drying to obtain an addition polymer E-2. The physical properties of the obtained addition polymer are shown in Table 4.

[0131] [Table 4]

[0132] Production Example F1 (Production of Dispersion F-1 of Particles Containing Colorant and Addition Polymer) In a 5 L vessel equipped with a stirrer equipped with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 17 g of the addition polymer E-1 and 630 g of methyl ethyl ketone were placed 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 such that the degree of neutralization of the addition polymer E-1 becomes 80 mol%) was added, and further 955 g of deionized water was added, and the mixture was stirred with a disperser blade at 2000 r / min at 20° C. for 10 minutes. Next, 300 g of 15:3 Pigment Blue (manufactured by Dainichiseika Color & Chemicals Co., Ltd., "ECB301") was added, and the mixture was stirred with a dispersing blade at 6400 r / min at 20°C for 2 hours. After that, the mixture was passed through a 200 mesh filter, and treated with a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics) at a pressure of 150 MPa for 15 passes. While stirring the obtained dispersion, methyl ethyl ketone and a part of the water were removed under reduced pressure at 70°C. After cooling, the mixture was passed through a 200 mesh filter, and deionized water was added so that the solid content concentration was 28% by mass, thereby obtaining a dispersion F-1 of particles containing a colorant and an addition polymer. The volume median particle diameter D of the particles in the obtained dispersion F-1 was 50 The thickness was 0.08 μm and the CV value was 20%.

[0133] Production Example F2 (Production of Dispersion F-2 of Particles Containing Colorant and Addition Polymer) In a 5 L vessel equipped with a stirrer equipped with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 75 g of the addition polymer E-1 and 630 g of methyl ethyl ketone were placed and the resin was dissolved at 20° C. To the resulting solution, 51 g of a 5% by mass aqueous sodium hydroxide solution (an amount such that the degree of neutralization of the addition polymer E-1 becomes 80 mol%) was added, and further 955 g of deionized water was added, and the mixture was stirred with a disperser blade at 2000 r / min at 20° C. for 10 minutes. Next, 300 g of 15:3 Pigment Blue (manufactured by Dainichiseika Chemicals Co., Ltd., "ECB301") was added, and the mixture was stirred with a dispersing blade at 6400 r / min at 20°C for 2 hours. The mixture was then passed through a 200 mesh filter, and treated 15 times with a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics) at a pressure of 150 MPa. The resulting dispersion was stirred at 70°C under reduced pressure to remove methyl ethyl ketone and a portion of the water. After cooling, the mixture was passed through a 200 mesh filter, and deionized water was added so that the solid content concentration was 28% by mass, thereby obtaining a dispersion F-2 of particles containing a colorant and an addition polymer. The volume median particle diameter D of the particles in the resulting dispersion F-2 was 150 r / min at 20°C ... 50 The thickness was 0.08 μm and the CV value was 20%.

[0134] Production Example F3 (Production of Dispersion F-3 of Particles Containing Colorant and Addition Polymer) Dispersion F-3 of particles containing a colorant and an addition polymer was prepared in the same manner as in F1, except that the colorant was changed as shown in Table 5. The physical properties of the particles in dispersion F-3 are shown in Table 5.

[0135] Production Examples F4 to F6 (Production of Particle Dispersions F-4 to F-6 Containing Colorant and Addition Polymer) Dispersions F-4 to F-6 of particles containing a colorant and an addition polymer were prepared in the same manner as F2, except that the colorant was changed as shown in Table 5. The physical properties of the particles in dispersions F-4 to F-6 are shown in Table 5.

[0136] Production Example F7 (Production of Dispersion F-7 of Particles Containing Colorant and Addition Polymer) In a 5 L vessel equipped with a stirrer equipped with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 75 g of the addition polymer E-2 and 630 g of methyl ethyl ketone were placed and the resin was dissolved at 20° C. To the resulting solution, 101 g of a 5% by mass aqueous sodium hydroxide solution (an amount such that the degree of neutralization of the addition polymer E-1 becomes 91 mol%) was added, and further 955 g of deionized water was added, and the mixture was stirred with a disperser blade at 2000 r / min at 20° C. for 10 minutes. Next, 300 g of 15:3 Pigment Blue (manufactured by Dainichiseika Chemicals Co., Ltd., "ECB301") was added, and the mixture was stirred with a dispersing blade at 6400 r / min at 20°C for 2 hours. The mixture was then passed through a 200 mesh filter, and treated 15 times with a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics) at a pressure of 150 MPa. The resulting dispersion was stirred at 70°C under reduced pressure to remove methyl ethyl ketone and a portion of the water. After cooling, the mixture was passed through a 200 mesh filter, and deionized water was added so that the solids concentration was 28% by mass, thereby obtaining a dispersion F-7 of particles containing a colorant and an addition polymer. The volume median particle diameter D of the particles in the resulting dispersion F-7 was 150 r / min. 50 The thickness was 0.12 μm and the CV value was 20%.

[0137] Production Example F8 (Production of Colorant Dispersion F-8) In a beaker with an internal volume of 1 L, 100 g of Pigment Blue 15:3 (manufactured by Dainichiseika Color & Chemicals Co., Ltd., "ECB301"), 167 g of 15 mass % sodium dodecylbenzenesulfonate aqueous solution "Neopelex G-15" (manufactured by Kao Corporation, anionic surfactant), and 102 g of deionized water were mixed and dispersed at 20°C and a stirring blade rotation speed of 8000 r / min for 1 hour using a homogenizer "TKAGI HOMOMIXER 2M-03" (manufactured by Primix Corporation), and then processed 15 times at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). Then, the mixture was passed through a 200 mesh filter, and deionized water was added so that the solid concentration was 28 mass %, to obtain a colorant dispersion liquid F-8. The volume median particle diameter D of the particles in the obtained dispersion liquid F-8 was 50 The thickness was 0.12 μm and the CV value was 22%.

[0138] [Table 5] *1:ECB301 refers to the cyan pigment "ECB301" (CI Pigment Blue 15:3, manufactured by Dainichi Seikagaku Kogyo Co., Ltd.). *2:5GX01 refers to the yellow pigment "Hansa Yellow 5GX01" (Clariant, CI Pigment Yellow 74). *3:MAGENTA R refers to the magenta pigment "FASTOGEN SUPER MAGENTA R" manufactured by Clariant, CI Pigment Red 122). *4:Regal 330R refers to the carbon black pigment "Regal 330R" (Cabot Corporation, CI Pigment Black 7). *5:Printex F80 refers to the carbon black pigment "Printex F80" (Orion Engineered Carbons, CI Pigment Black 7). *6: G-15 refers to the aqueous solution of sodium dodecylbenzenesulfonate "Neopelex G-15" (anionic surfactant, manufactured by Kao Corporation). *7: Indicates the mass ratio of colorant to surfactant.

[0139] [Production of colorant particle dispersion] Production Example G1 (Production of Colorant Particle Dispersion G-1) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-1 (solid content concentration 28% by mass), 3.8 g of p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy equivalent 255 g / eq), and 215 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-1 with a solid content concentration of 20% by mass. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0140] Production Example G2 (Production of Colorant Particle Dispersion G-2) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-2 (solid content concentration 28 mass%), 15.4 g of p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy equivalent 255 g / eq), and 261 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-2 with a solid content concentration of 20 mass%. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0141] Production Example G3 (Production of Colorant Particle Dispersion G-3) A colorant particle dispersion G-3 having a solid content concentration of 20% by mass was obtained in the same manner as in Production Example G1, except that the type of dispersion used was changed as shown in Table 6. The volume median particle diameter D of the obtained colorant particles 50and CV values ​​are shown in Table 6.

[0142] Production Examples G4 to G6 (Production of Colorant Particle Dispersions G-4 to G-6) Colorant particle dispersions G-4 to G-6 with a solid content concentration of 20% by mass were obtained in the same manner as in Production Example G2, except that the type of dispersion used was changed as shown in Table 6. The volume median particle diameter D 50 and CV values ​​are shown in Table 6.

[0143] Production Example G7 (Production of Colorant Particle Dispersion G-7) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-1 (solid content concentration 28% by mass), 2.3 g of p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy equivalent 255 g / eq), and 209 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-7 with a solid content concentration of 20% by mass. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0144] Production Example G8 (Production of Colorant Particle Dispersion G-8) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-1 (solid content concentration 28% by mass), 5.3 g of p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy equivalent 255 g / eq), and 221 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-8 with a solid content concentration of 20% by mass. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0145] Production Example G9 (Production of Colorant Particle Dispersion G-9) 500g of dispersion F-1 (solid content concentration 28% by mass), 2.8g of 2-ethylhexyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-121, molecular weight 186, epoxy value 187g / eq), and 211g of deionized water were added to a 1L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-9 with a solid content concentration of 20% by mass. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0146] Production Example G10 (Production of Colorant Particle Dispersion G-10) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-1 (solid content concentration 28 mass%), 14.6 g of lauryl alcohol EO (15) glycidyl ether (Nagase ChemteX Corporation, Denacol EX-171, molecular weight 903, epoxy value 971 g / eq), and 259 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-10 with a solid content concentration of 20 mass%. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0147] Production Example G11 (Production of Colorant Particle Dispersion G-11) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-1 (solid content concentration 28 mass%), 6.0 g of phenol EO(5) glycidyl ether (Nagase ChemteX Corporation, Denacol EX-145, molecular weight 370, epoxy value 400 g / eq), and 224 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-11 with a solid content concentration of 20 mass%. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0148] Production Example G12 (Production of Colorant Particle Dispersion G-12) Into a 1 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of dispersion F-6 (solid content concentration 28% by mass), 7.0 g of p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy value 255 g / eq), and 228 g of deionized water were added and mixed, and heated at 80°C for 3 hours while stirring with a stirrer. After 3 hours, the temperature was lowered to room temperature and passed through a 200 mesh filter to obtain colorant particle dispersion G-12 with a solid content concentration of 20% by mass. The volume median particle diameter D of the obtained colorant particles was 50 and CV values ​​are shown in Table 6.

[0149] Production Examples G13 to 15 (Production of Colorant Particle Dispersions G-13 to G-15) Colorant particle dispersions G-13 to G-15 with a solid content concentration of 20% by mass were obtained in the same manner as in Production Example G1, except that the type of dispersion used was changed as shown in Table 6, no monofunctional compound was used, and 200 g of deionized water was added. 50 and CV values ​​are shown in Table 6.

[0150] [Table 6] *1: H-1 means p-tert-butylphenyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-146, molecular weight 197, epoxy value 255 g / eq). *2: H-2 means 2-ethylhexyl glycidyl ether (Nagase ChemteX Corporation, Denacol EX-121, molecular weight 186, epoxy value 187g / eq). *3: H-3 means lauryl alcohol EO (15) glycidyl ether (Nagase ChemteX Corporation, Denacol EX-171, molecular weight 903, epoxy value 971 g / eq). *4: H-4 means phenol EO(5) glycidyl ether (Nagase ChemteX Corporation, Denacol EX-145, molecular weight 370, epoxy value 400 g / eq). *5: This refers to the amount (parts by mass) of a monofunctional compound relative to 100 parts by mass of particles containing a colorant and an addition polymer. *6: This refers to the molar ratio of the carboxyl group reactive group in the monofunctional compound to the amount of carboxyl groups in the addition polymer (carboxyl group reactive group / carboxy group).

[0151] [Toner manufacturing] Example 1 (Production of Toner 1) In a 3 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500 g of resin particle dispersion X-1, 29 g of wax particle dispersion W-1, 28 g of wax particle dispersion W-2, 44 g of monofunctional compound reactive colorant particle dispersion G-1, 15 g of a 10 mass% aqueous solution of polyoxyethylene (50) lauryl ether "EMULGEN 150" (manufactured by Kao Corporation, nonionic surfactant), and 17 g of a 15 mass% aqueous solution of sodium dodecylbenzenesulfonate "NEOPELEX G-15" (manufactured by Kao Corporation, anionic surfactant) were mixed at a temperature of 25° C. Next, while stirring the mixture, a solution obtained by dissolving 40 g of ammonium sulfate in 568 g of deionized water and adding a 4.8 mass% aqueous solution of potassium hydroxide to adjust the pH to 8.6 was dropped over 10 minutes at 25° C., and the temperature was raised to 61° C. over 2 hours, and the volume median particle diameter D of the aggregated particles was measured. 50 The temperature was maintained at 61° C. until the particle diameter reached 6.2 μm, to obtain a dispersion of aggregated particles. To the obtained dispersion of aggregated particles, an aqueous solution of 48 g of sodium polyoxyethylene lauryl ether sulfate "EMAL E-27C" (Kao Corporation, anionic surfactant, effective concentration 27% by mass), 313 g of deionized water, and 40 g of 0.1 mol / L aqueous sulfuric acid solution was added. The temperature was then raised to 75°C over 1 hour, and the mixture was kept at 75°C for 30 minutes, after which 20 g of 0.1 mol / L aqueous sulfuric acid solution was added and the mixture was further kept at 75°C for 15 minutes. Thereafter, 20 g of 0.1 mol / L aqueous sulfuric acid solution was added again, and the mixture was kept at 75°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles in which aggregated particles were fused. The obtained dispersion of fused particles was cooled to 30°C, and the solid content was separated by suction filtration of the dispersion, washed with deionized water at 25°C, and suction filtration was performed for 2 hours at 25°C. Thereafter, the solid content was vacuum dried at 33°C for 24 hours using a vacuum constant temperature dryer "DRV622DA" (manufactured by ADVANTEC Co., Ltd.) to obtain toner particles. 100 parts by mass of toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size; 0.04 μm), and 1.0 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., number average particle size; 0.012 μm) were put into a Henschel mixer and stirred, and passed through a 150 mesh sieve to obtain toner 1. The physical properties of the obtained toner and the evaluation results of the toner are shown in Table 7.

[0152] Examples 2 to 14 and Comparative Examples 1 to 3 (Preparation of Toners 2 to 17) Toners 2 to 17 were obtained in the same manner as in Example 1, except that the types of resin particle dispersion liquid and colorant particle dispersion liquid used were changed as shown in Table 7. The physical properties of the obtained toners and the evaluation results of the toners are shown in Table 7.

[0153] [Table 7]

[0154] As shown in Table 7, the results of the Examples and Comparative Examples show that by using the toner for developing electrostatic images obtained by the manufacturing method of the present invention, printed matter having high image density and dot reproducibility can be obtained. On the other hand, the toners obtained by the manufacturing methods of Comparative Examples 1 and 2, in which a dispersion of particles containing a colorant and an addition polymer was used as a colorant dispersion, and the toner obtained by the manufacturing method of Comparative Example 3, in which a colorant particle dispersion in which a colorant was dispersed using an anionic surfactant was used, had low dot reproducibility and poor image density.

Claims

1. A method for producing a toner for developing electrostatic images, comprising a step of aggregating and fusing resin particles and colorant particles in an aqueous medium, the colorant particles are obtained by a step of mixing particles containing a colorant and an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group, with a monofunctional compound having one functional group reactive with a carboxy group in the molecule; A method for producing a toner for developing electrostatic images.

2. 2. The method for producing a toner for developing electrostatic images according to claim 1, further comprising a step of heating the mixture at a temperature of 50[deg.] C. or higher after the mixing step.

3. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the functional group reactive with a carboxy group is selected from an oxazoline group or an epoxy group.

4. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the raw material monomer further comprises an addition-polymerizable monomer having a polyalkylene oxide group.

5. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein a ratio of the number of moles of functional groups reactive with carboxy groups in the monofunctional compound to the number of moles of carboxy groups in the addition polymer (functional groups reactive with carboxy groups in the monofunctional compound / carboxy groups in the addition polymer) is 0.30 or more and 0.70 or less.

6. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein a mass ratio of the colorant to the addition polymer (colorant / addition polymer) is 60 / 40 or more and 98 / 2 or less.

7. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the particles containing the colorant and the addition polymer are obtained by a production method comprising the following steps a and b: Step a: mixing an addition polymer with an organic solvent, and then further mixing with an aqueous medium to obtain a dispersion of the addition polymer; Step b: A step of dispersing the dispersion obtained in step a and a colorant to obtain a dispersion of particles containing the colorant and the addition polymer.

8. 8. The method for producing a toner for developing electrostatic images according to claim 1, wherein the resin particles contain an amorphous polyester resin.

9. A method for producing a colorant particle dispersion liquid, comprising the following steps a to c: Step a: a step of mixing an addition polymer of raw material monomers including an addition polymerizable monomer having an aromatic group and an addition polymerizable monomer having a carboxy group with an organic solvent, and then further mixing with an aqueous medium to obtain a dispersion of the addition polymer; Step b: A step of dispersing the dispersion obtained in step a and a colorant to obtain a dispersion of particles containing the colorant and the addition polymer. Step c: A step of mixing the dispersion of particles containing the colorant and the addition polymer obtained in step b with a monofunctional compound having one functional group reactive with a carboxy group in the molecule.