Toner for electrostatic charge image development and method for producing the same

Abstract

To provide a toner for electrostatic charge image development which enables formation of a printed coating film having high fastness on a printing medium (base material) such as a plastic film, and a method for producing the same.SOLUTION: A toner for electrostatic charge image development contains toner particles containing an amorphous resin A, a crystalline polyester resin C, and a coloring agent, wherein the crystalline polyester resin C contains a polycondensation product of an alcohol component, and a carboxylic acid component having 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less, and when a value obtained by dividing the total number of -NH- and -NH2 in one molecule by a molecular amount is represented by an NH group amount, the coloring agent contains a yellow pigment having an NH group amount of 6.0 mmol / g or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] The diversification of print media has led to a growing demand for electrophotographic printing on print media other than paper. Major media include plastic films such as polyethylene terephthalate film, polypropylene film, and polyethylene film, which are used for PET bottle labels and various packages. Because these plastic films have smooth surfaces, the anchoring effect between the surface and the coating film (printed coating film) formed by printing electrophotographic toner on the surface is poor, and the printed coating film is prone to peeling off from the plastic film. Patent Document 1 discloses a method for forming an image on a polypropylene film or a polyethylene film using a toner containing a crystalline polyester resin C in a binder resin, with the aim of providing an image forming method that produces an image with excellent image density and excellent abrasion resistance, wherein the SP value of the crystalline polyester resin C is 9.0 or more and 10.1 or less, the content of the crystalline polyester resin C in the binder resin is 10% by mass or more and 60% by mass or less, the surface tension of the printed surface of the polypropylene film or polyethylene film is 35 mN / m or more and 49 mN / m or less, and the fixing temperature is not more than a temperature 5°C higher than the melting point of the polypropylene film or polyethylene film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-54448 Summary of the Invention [Problem to be solved by the invention]

[0004] Printed packaging materials such as PET bottle labels and packaging films require high robustness of the printed coating film from the viewpoint of protecting the quality of the contents and displaying information. The hardness of printed coating films formed using printing inks for printed packaging materials is evaluated by a pencil hardness test. The inventors of the present invention have conducted research and found that, while the printed packaging materials obtained by forming a printed coating film on a printing medium such as a plastic film using the image forming method described in Patent Document 1 have robustness of the printed coating film in tape peel tests and fingernail scraping tests, their robustness in pencil hardness tests needs improvement. The present invention relates to a toner for developing electrostatic images, which is capable of forming a highly durable printing coating film on a printing medium (substrate) such as a plastic film, and a method for producing the same. [Means for solving the problem]

[0005] The present inventors have found that when toner particles contain an amorphous resin, a crystalline polyester resin, and a colorant, the crystalline polyester resin is a polycondensate of an alcohol component and a carboxylic acid component containing a specific amount or more of an aliphatic dicarboxylic acid having four carbon atoms, the ester group concentration of the crystalline polyester resin C is within a specific range, and the colorant contains a yellow pigment having an NH group amount equal to or greater than a specific value, a printed coating film with high robustness can be formed using a toner for developing electrostatic images containing the above toner particles. The present invention relates to the following [1] and [2]. [1] A toner for developing electrostatic images, comprising toner particles containing an amorphous resin A, a crystalline polyester resin C, and a colorant, the crystalline polyester resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less; The colorant contains a yellow pigment having an NH group amount of 6.0 mmol / g or more, when the total number of -NH- and -NH2 contained in one molecule is divided by the molecular weight to define the NH group amount. Toner for developing electrostatic images. [2] A method for producing a toner for developing electrostatic images, comprising a step of aggregating and fusing resin particles, the resin particles containing an amorphous resin A and a crystalline polyester resin C in the same or different particles, and a colorant in an aqueous medium, the method comprising: the crystalline polyester resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less; The colorant contains a yellow pigment having an NH group amount of 6.0 mmol / g or more, when the total number of -NH- and -NH2 contained in one molecule is divided by the molecular weight to define the NH group amount. A method for producing a toner for developing electrostatic images. [Effects of the Invention]

[0006] According to the present invention, there are provided a toner for developing electrostatic images, which is capable of forming a highly durable printing coating film on a printing medium (substrate) such as a plastic film, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0007] [Electrostatic image developing toner] The toner for developing electrostatic images (hereinafter also simply referred to as "toner") of the present invention contains an amorphous resin A, a crystalline polyester resin C (hereinafter also simply referred to as "resin C"), and a colorant. The crystalline polyester resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, the ester group concentration of the crystalline polyester resin C is 6.0 mmol / g or more and 9.5 mmol / g or less, and the colorant contains a yellow pigment having an NH group amount of 6.0 mmol / g or more, when the NH group amount is the total number of -NH- and -NH2 groups in one molecule divided by the molecular weight. Due to the above-mentioned characteristics, the toner of the present invention can provide a printed coating film with high durability. Although toner particles containing amorphous resin A, resin C, and a colorant (hereinafter simply referred to as "toner particles") can be used as they are as the toner of the present invention, 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.

[0008] The reason why the toner of the present invention can provide a printed coating film with high fastness is not clear, but is thought to be as follows. It has been found that the hardness of the printed coating film itself is important for improving the pencil hardness test durability of printed coating films formed on substrates such as plastic films. This is thought to be due to the strong localized force applied when scraping the coating film with a sharp pencil. In the toner of the present invention, the crystalline polyester resin C contained in the toner particles is a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of a C4 aliphatic dicarboxylic acid, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less. Furthermore, since the NH group content of the yellow pigment colorant is 6.0 mmol / g or more, the ester groups in the crystalline polyester resin C, including adjacent ester groups derived from a C4 aliphatic dicarboxylic acid, and the NH groups contained in the yellow pigment effectively interact with each other, significantly improving the cohesive strength of the crystalline polyester resin C. As a result, after coating film formation, recrystallization of the crystalline polyester resin C is promoted in the amorphous resin A, which is thought to increase the hardness of the printed coating film and improve its durability.

[0009] The definitions of various terms used in this specification are shown 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 carboxylic acids, 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 its crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the endothermic maximum peak temperature (softening point (°C) / endothermic maximum peak temperature (°C)) measured by the 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 an endothermic peak is observed, one with a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be adjusted appropriately by adjusting 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 parenthetical expressions "(iso or tertiary)" and "(iso)" refer to both the presence and absence of these prefixes; the absence of these prefixes indicates normal. "(Meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid. The term "styrenic compound" means unsubstituted or substituted styrene.

[0010] [Toner particles] In the present invention, the toner particles contain an amorphous resin A, a crystalline polyester resin C (hereinafter also simply referred to as "resin C"), and a colorant. The toner particles may contain one kind of each component (essential component and optional component) such as amorphous resin A, resin C, and colorant, or may contain two or more kinds in combination. Furthermore, the raw materials of each component contained in the toner particles, such as alcohol component and carboxylic acid component, may be used one kind alone, or two or more kinds in combination.

[0011] <Amorphous resin A> In the present invention, the amorphous resin A preferably contains an amorphous polyester resin A.

[0012] (Amorphous polyester resin A) The amorphous polyester resin A is used as a binder resin for toner and is, for example, an amorphous polyester resin containing a polycondensate of an alcohol component and a carboxylic acid component. Hereinafter, the amorphous polyester resin A may be simply referred to as "resin A." Examples of resin A include polyester resins and modified polyester resins. Examples of modified polyester resins include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing polyester resin segments and addition polymerization resin segments. Among these, resin A is preferably a polyester resin or a composite resin, and more preferably a composite resin.

[0013] Examples of the alcohol component of Resin A include alkylene oxide adducts of aromatic diols, aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols are preferred from the viewpoint of low-temperature fixability of the toner. 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):

[0014] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each a positive number that indicates the average number of moles of alkylene oxide added, 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.

[0015] Examples of the alkylene oxide adduct of bisphenol A represented by formula (I) include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. Among these, it is preferable to contain a propylene oxide adduct of bisphenol A. In the alcohol component, the content of alkylene oxide adduct of bisphenol A is preferably 80 mol % or more, more preferably 90 mol % or more, and is 100 mol % or less, and even more preferably 100 mol %.

[0016] Examples of 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, 1,12-dodecanediol, and 3-methyl-1,5-pentanediol. 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 added moles: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.

[0017] Examples of the carboxylic acid component of Resin A include dicarboxylic acids and trivalent or higher polycarboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one selected from aromatic dicarboxylic acids and 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. The amount of aromatic dicarboxylic acid in the carboxylic acid component is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less.

[0018] The aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably has 30 or less carbon atoms, more preferably 20 or less carbon atoms. Examples of 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 acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms. Examples of succinic acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, fumaric acid, succinic acid, sebacic acid, adipic acid, and succinic acids substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms are preferred, with fumaric acid and sebacic acid being more preferred. The amount of aliphatic dicarboxylic acid in the carboxylic acid component is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and preferably 60 mol% or less, more preferably 50 mol% or less, even more preferably 40 mol% or less. An example of the alicyclic dicarboxylic acid is cyclohexanedicarboxylic acid.

[0019] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, such as trimellitic acid. 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 3 mol% or more, more preferably 6 mol% or more, even more preferably 9 mol% or more, and is preferably 25 mol% or less, more preferably 20 mol% or less, even more preferably 15 mol% or less.

[0020] 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 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0021] When the resin A is a composite resin, an example of the addition polymerized resin segment is an addition polymer of raw material monomers containing a styrene-based compound. Examples of styrene compounds 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 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 styrene-based compounds 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.

[0022] 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; halovinyl compounds 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 alkyl (meth)acrylates 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, stearyl (meth)acrylate is more preferred, and stearyl methacrylate is even more preferred.

[0023] When the addition polymerization resin segment contains a structural unit derived from a (meth)acrylic acid ester, the content of the (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, even more preferably 25% by mass or less.

[0024] The total amount of the styrene compound and (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 100% by mass.

[0025] The composite resin preferably has a constitutional unit derived from a bireactive monomer bonded via a covalent bond to a polyester resin segment and an addition polymerized 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 addition-polymerizable monomers having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, from the viewpoint of reactivity in both polycondensation reactions and addition polymerization reactions, 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 unit derived from the bireactive monomer is preferably 1 mol part or more, more preferably 5 mol parts or more, even more preferably 8 mol parts or more, and preferably 30 mol parts or less, more preferably 25 mol parts or less, even more preferably 20 mol parts or less, relative to 100 mol parts of the alcohol component of the polyester resin segment of the composite resin.

[0026] The content of the polyester resin segment in the composite resin is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 55% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment. The structural unit derived from the bireactive monomer is referred to as the polyester resin segment.

[0027] The content of the addition polymerization resin segment in the composite resin is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, even more preferably 45% by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment.

[0028] The amount of the bireactive monomer-derived structural units in the composite resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 4% by mass or less, based on the total amount of the polyester resin segment and the addition polymerization resin segment.

[0029] The total amount of polyester resin segments and addition polymerization resin segments in the composite resin is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and is 100% by mass or less, even more preferably 100% by mass.

[0030] The above amounts are calculated based on the ratio of the amounts of the polyester resin segment, raw material monomer for the addition polymerization resin segment, bireactive monomer, and radical polymerization initiator, and the mass of the polyester resin segment, etc. is based on the mass excluding the mass of water produced by polycondensation. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is calculated by including it in the mass of the addition polymerization resin segment.

[0031] <Method for producing amorphous polyester resin A> -Method for producing amorphous polyester resin- When the resin A is an amorphous polyester resin, the resin A can be produced by polycondensing raw material monomers containing an alcohol component and a carboxylic acid component. In this reaction, if necessary, an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropylate bistriethanolamine may be used in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) may be used in an amount of 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. When a monomer having an unsaturated bond such as fumaric acid is used in polycondensation, 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. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The reaction temperature is preferably 120°C or higher, more preferably 150°C or higher, even more preferably 170°C or higher, and is preferably 250°C or lower, more preferably 240°C or lower. The reaction may be carried out in an inert gas atmosphere.

[0032] -Method of manufacturing composite resin- When resin A is a composite resin containing a polyester resin segment and an addition polymerization resin segment, it may be produced, for example, by a method including step A of polycondensing an alcohol component and a carboxylic acid component, 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. A preferred method is to subject a portion of the carboxylic acid component to a polycondensation reaction in step A, then carry out step B, and then add the remainder of the carboxylic acid component to the polymerization system to further promote the polycondensation reaction of step A and the polycondensation reaction with, for example, a carboxy group possessed by the bireactive monomer or the constituent unit derived from the bireactive monomer.

[0033] In step A, if necessary, polycondensation may be carried out using the same amounts of the esterification catalyst and esterification promoter used in the above "Method for producing amorphous polyester resin". Furthermore, when a monomer having an unsaturated bond such as fumaric acid is used in polycondensation, the polymerization inhibitor used in the above "Method for producing amorphous polyester resin" may be used in the same amount as in the above "Method for producing amorphous polyester resin" as needed. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, and more preferably 240° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0034] 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 with respect to 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 even more preferably 210°C or lower.

[0035] <Physical properties of amorphous polyester resin A> The softening point of Resin A is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, even more preferably 125°C or lower. The glass transition temperature of Resin A is preferably 30°C or higher, more preferably 35°C or higher, even more preferably 40°C or higher, and preferably 80°C or lower, more preferably 75°C or lower, even more preferably 70°C or lower.

[0036] The acid value of Resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, even more preferably 30 mgKOH / g or less.

[0037] The softening point, glass transition temperature, and acid value of Resin A can be appropriately adjusted by adjusting the types and amounts of raw material monomers 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 resins A are used in combination, it is preferable that at least one of them has the above-mentioned ranges for each of the physical properties.Moreover, it is more preferable that the softening point, glass transition temperature, and acid value obtained as a mixture of these resins each fall within the above-mentioned ranges.

[0038] From the viewpoint of the robustness of the printed coating film, the content of the amorphous resin A in the toner particles is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, even more preferably 75% by mass or less.

[0039] From the viewpoint of the robustness of the printed coating film, the content of amorphous polyester resin A in amorphous resin A is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and is 100% by mass or less, preferably 100% by mass.

[0040] <Crystalline polyester resin C> Resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less. Resin C may be a composite resin containing a polyester resin segment and an addition polymerization resin segment, but is preferably a polycondensate of an alcohol component and a carboxylic acid component.

[0041] From the viewpoint of fastness of the printed coating film, the ester group concentration of Resin C is 6.5 mmol / g or more and 9.0 mmol / g or less, preferably 6.7 mmol / g or more and preferably 8.8 mmol / g or less, more preferably 8.5 mmol / g or less, and even more preferably 8.2 mmol / g or less. The ester group concentration of Resin C is calculated by the following formula.

[0042]

number

[0043] The alcohol component is preferably an α,ω-aliphatic diol. The α,ω-aliphatic diol has preferably 2 or more, more preferably 4 or more, even more preferably 6 or more, even more preferably 8 or more carbon atoms, and preferably 16 or less, more preferably 14 or less, even more preferably 12 or less carbon atoms. Examples of α,ω-aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol. Among these, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol are preferred, 1,9-nonanediol and 1,12-dodecanediol are more preferred, and 1,9-nonanediol is even more preferred.

[0044] The amount of α,ω-aliphatic diol in the alcohol component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and is 100 mol% or less, preferably 100 mol%.

[0045] The alcohol component may contain an alcohol component other than the α,ω-aliphatic diol. Examples of other alcohol components include aliphatic monoalcohols such as stearyl alcohol and behenyl alcohol; alkylene oxide adducts of aromatic diols such as alkylene oxide adducts of bisphenol A; and trihydric or higher alcohols such as glycerin, pentaerythritol, and trimethylolpropane.

[0046] From the viewpoint of crystallinity, the carboxylic acid component contains 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms. Specific examples of the aliphatic dicarboxylic acid having 4 carbon atoms include succinic acid, fumaric acid, and maleic acid. Among these, succinic acid and fumaric acid are preferred, and fumaric acid is more preferred.

[0047] The amount of the aliphatic dicarboxylic acid having 4 carbon atoms in the carboxylic acid component is 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more, and even more preferably 85 mol% or more, and is 100 mol% or less, preferably 95 mol% or less. The carboxylic acid component may contain an aliphatic dicarboxylic acid other than an aliphatic dicarboxylic acid having 4 carbon atoms, and is preferably an α,ω-aliphatic dicarboxylic acid. Specific examples of aliphatic dicarboxylic acids other than the aliphatic dicarboxylic acids having 4 carbon atoms include adipic acid, sebacic acid, 1,11-undecanedioic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, and 1,16-hexadecanedioic acid.

[0048] From the viewpoints of hydrophobicity and crystallinity, the carboxylic acid component preferably contains a monocarboxylic acid. From the same viewpoints, the number of carbon atoms of the monocarboxylic acid is preferably 6 or more, more preferably 8 or more, even more preferably 12 or more, even more preferably 16 or more, and preferably 24 or less, more preferably 22 or less, even more preferably 20 or less. Examples of monocarboxylic acids include caprylic acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, etc. Among these, preferred are caprylic acid, lauric acid, stearic acid, and behenic acid, and from the viewpoints of hydrophobicity and crystallinity, more preferred are stearic acid and behenic acid, and even more preferred is stearic acid. When the carboxylic acid component contains a monocarboxylic acid, the amount of the monocarboxylic acid in the carboxylic acid component is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and preferably 25 mol% or less, more preferably 20 mol% or less, even more preferably 15 mol% or less. The carboxylic acid component may contain other carboxylic acid components different from aliphatic dicarboxylic acids and monocarboxylic acids, such as aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and trivalent or higher polycarboxylic acids such as trimellitic acid.

[0049] 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 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0050] Resin C can be produced, for example, in the same manner as Resin A.

[0051] (Physical properties of crystalline polyester resin C) The softening point of Resin C is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher, and from the viewpoint of further improving low-temperature fixability, it is preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower.

[0052] The melting point of Resin C is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher, and from the viewpoint of further improving low-temperature fixability, it is preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower.

[0053] The acid value of Resin C is preferably 2 mgKOH / g or more, more preferably 4 mgKOH / g or more, and preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, and even more preferably 10 mgKOH / g or less.

[0054] The ester group concentration, softening point, melting point, and acid value of Resin C can be appropriately adjusted by the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and the softening point, melting point, and acid value are determined by the methods described in the Examples. When two or more types of Resin C are used in combination, it is preferable that the ester group concentration, softening point, melting point, and acid value obtained as a mixture thereof each fall within the above-mentioned ranges.

[0055] In the toner particles, the mass ratio of the amorphous resin to the resin C [resin C / amorphous resin A] is preferably 5 / 95 or more, more preferably 10 / 90 or more, even more preferably 13 / 87 or more, even more preferably 15 / 85 or more, from the viewpoint of the robustness of the printed coating film, and is preferably 40 / 60 or less, more preferably 35 / 65 or less.

[0056] The content of resin C in the toner particles is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 13% by mass or more, even more preferably 15% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less.

[0057] <Coloring agent> In the present invention, the toner particles contain a yellow pigment as a colorant. When the total number of -NH- and -NH2 groups in one molecule of the yellow pigment is divided by the molecular weight of the yellow pigment to define the NH group amount, the NH group amount of the yellow pigment is 6.0 mmol / g or more. There is no particular upper limit, but it is preferably 20.0 mmol / g or less, and more preferably 15.0 mmol / g or less. The yellow pigment is preferably a yellow organic pigment, and from the viewpoint of achieving a desired amount of NH groups, is preferably at least one of an isoindoline pigment and a benzimidazolone pigment. Examples of isoindoline pigments include CI Pigment Yellow 139 (total number of -NH- and -NH2 groups in one molecule = 5, molecular weight = 367, NH group amount = 13.6 mmol / g) and CI Pigment Yellow 185 (total number of -NH- and -NH2 groups in one molecule = 4, molecular weight = 337, NH group amount = 11.9 mmol / g). An example of a benzimidazolone pigment is CI Pigment Yellow 180 (total number of -NH- and -NH2 groups in one molecule=6, molecular weight=733, NH group amount=8.2 mmol / g). The yellow pigment used in the present invention is preferably at least one selected from CI Pigment Yellow 185 and CI Pigment Yellow 180, from the viewpoint of obtaining a printed coating film with high fastness.

[0058] The content of the colorant in the toner particles is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the total of amorphous resin A and resin C, from the viewpoint of improving dispersibility in the toner particles. The content of the colorant in the toner particles is, from the viewpoint of the robustness of the printed coating film, preferably 3 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 40 parts by mass or less, per 100 parts by mass of Resin C in the toner particles, from the viewpoint of the robustness of the printed coating film. The content of the colorant in the toner particles is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less. The content of the yellow pigment in the colorant is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, still more preferably 98% by mass or more, and is 100% by mass or less, preferably 100% by mass.

[0059] <Release agent> The toner particles of the present invention preferably contain a release agent. Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, ethylene-propylene 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.

[0060] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 100°C or lower. The content of the release agent in the toner particles is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% 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. In addition, the toner particles may contain additives such as a charge control agent, a magnetic powder, a flowability improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, an antiaging agent, and a cleaning property improver.

[0061] (Physical properties of toner particles) Volume median particle size D of toner particles 50 From the viewpoint of obtaining a printed coating film with good image quality and further improving the cleaning properties of the toner, the thickness 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 8 μm or less, even more preferably 7 μm or less.

[0062] The circularity of the toner particles is preferably 0.940 or more, more preferably 0.950 or more, and even more preferably 0.960 or more, from the viewpoint of obtaining a printed image of good quality, and is preferably 0.990 or less, more preferably 0.985 or less, and even more preferably 0.980 or less, from the viewpoint of cleanability.

[0063] Volume median particle size D of toner particles 50 The circularity can be measured by the method described in the Examples.

[0064] [Method of manufacturing electrostatic image developing toner] The method for producing the toner for developing electrostatic images of the present invention (hereinafter also referred to as "toner production method") may be any known method such as a melt-kneading method, an emulsion phase inversion method, a suspension polymerization method, or an emulsion aggregation method, but the emulsion aggregation method is preferred.

[0065] [Emulsification aggregation method] The emulsion aggregation method includes a step of aggregating and fusing resin particles containing amorphous resin A and resin C in the same or different particles, and a colorant in an aqueous medium.

[0066] <Step of aggregating resin particles> In the step of aggregating the resin particles, resin particles containing amorphous resin A and resin C in the same or different particles and a colorant are aggregated in an aqueous medium to obtain aggregated particles 1. It is preferable to mix a resin particle dispersion containing resin particles with a colorant particle dispersion containing a colorant to aggregate these particles and obtain aggregated particles 1. Here, it is preferable to further aggregate a release agent in addition to the resin particles and colorant, and it is more preferable to mix a resin particle dispersion, a colorant particle dispersion, and a release agent particle dispersion to aggregate these particles and obtain aggregated particles 1.

[0067] In the present invention, the aqueous medium is a medium containing water as a main component, and the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and 100% by mass or less. The water is preferably deionized water or distilled water. Examples of components other than water that can constitute the aqueous medium together with water include water-soluble organic solvents such as alkyl alcohols having 1 to 5 carbon atoms, dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone, and cyclic ethers such as tetrahydrofuran. Among these, alkyl alcohols having 1 to 5 carbon atoms are preferred, and ethanol is more preferred.

[0068] (Method of manufacturing resin particle dispersion) The resin particles of amorphous resin A and resin particles of resin C may be produced as an aqueous dispersion of resin particles containing amorphous resin A and resin C in the same or different particles.

[0069] Dispersion can be carried out using known methods, but is preferably carried out by a phase inversion emulsification method. Examples of the phase inversion emulsification method include a method in which an aqueous medium is added to an organic solvent solution of a resin or a molten resin to carry out phase inversion emulsification. A method in which an aqueous medium is added to an organic solvent solution of a resin to carry out phase inversion emulsification is preferred. The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin and is water-soluble, and examples thereof include methyl ethyl ketone. A neutralizing agent may be added to the organic solvent solution. 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. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred. The degree of neutralization of the resin contained in the resin particles 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 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 contained in the resin particles can be determined 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 constituting resin particles (mg KOH / g) × weight of resin constituting resin particles (g)} / (56 × 1000)]] × 100

[0070] While stirring the organic solvent solution or the molten resin, the aqueous medium is gradually added to cause phase inversion. From the viewpoint of improving the dispersion stability of resin particles containing the resin, the temperature of the organic solvent solution when the aqueous medium is added is preferably equal to or higher than the glass transition temperature of resin A, more preferably equal to or higher than 60°C, even more preferably equal to or higher than 70°C, and is preferably equal to or lower than 100°C, more preferably equal to or lower than 90°C, even more preferably equal to or lower than 80°C.

[0071] After the phase inversion emulsification, the organic solvent may be removed from the resulting dispersion by distillation or the like, if necessary. Alternatively, the resin particles may be isolated by filtration or the like. It is preferable to use an aqueous dispersion of resin particles obtained by removing the organic solvent from the dispersion obtained after the phase inversion emulsification. 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.

[0072] Resin particle volume median diameter D 50 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. The CV value of the resin particles is preferably 10% or more, more preferably 20% or more, and is preferably 40% or less, more preferably 35% or less. Resin particle volume median diameter D 50 The CV value is measured by the method described in the Examples.

[0073] From the viewpoint of improving toner productivity and dispersion stability of the resin particle dispersion, the solid content concentration of the resin 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. The solid content is the total amount of non-volatile components. Furthermore, in the process of aggregating the resin particles, the aggregated particles 1 may contain a release agent, and may also contain additives such as a charge control agent, a magnetic powder, a flowability improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, an antiaging agent, and a cleaning property improver.

[0074] (Method of manufacturing colorant particle dispersion) The colorant particle dispersion is preferably obtained by dispersing the yellow pigment and an aqueous medium using a disperser such as a homomixer, a homogenizer, an ultrasonic disperser, etc. The dispersion is preferably carried out in the presence of a surfactant, from the viewpoint of improving the dispersion stability of the yellow pigment. Furthermore, from the viewpoint of improving the dispersion stability of the yellow pigment, the dispersion of the yellow pigment may be carried out in the presence of addition polymer E. The addition polymer E preferably has a structural unit derived from addition polymerizable monomer a having an aromatic group, and preferably further contains at least one selected from the group consisting of addition polymerizable monomer b having an ionic group, addition polymerizable monomer c having a polyalkylene oxide group, and macromonomer d. For colorant particle dispersions using addition polymer E, reference is made to the addition polymer E described in JP 2024-25642 A.

[0075] Examples of surfactants that improve the dispersion stability of the yellow pigment include nonionic surfactants, anionic surfactants, and cationic surfactants. From the viewpoint of improving the dispersion stability of the yellow pigment, nonionic surfactants are preferred. Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, and polyoxyalkylene aryl ethers. Among these, polyoxyethylene aryl ethers are preferred, and polyoxyethylene distyrenated phenyl ether is more preferred.

[0076] From the viewpoint of improving the dispersion stability of the yellow pigment, the content of the surfactant in the colorant particle dispersion is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, relative to 100 parts by mass of the yellow pigment.

[0077] In the colorant particle dispersion, 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, and even more preferably 30% by mass or less. The solid content concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, 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.

[0078] Volume median particle size D of colorant particles 50 From the viewpoint of improving dispersibility in toner particles, the average particle size is preferably 0.05 μm or more, more preferably 0.08 μm or more, even more preferably 0.1 μm or more, and is preferably 0.4 μm or less, more preferably 0.3 μm or less, even more preferably 0.2 μm or less. From the viewpoint of improving dispersibility in toner particles, the CV value of the colorant particles is preferably 10% or more, more preferably 20% or more, and is preferably 45% or less, more preferably 40% or less, and even more preferably 35% or less. Volume median particle size D of colorant particles 50 and CV values ​​are measured by the methods in the Examples.

[0079] (Method of producing release agent particle dispersion) The release agent particle dispersion liquid can be obtained, for example, by dispersing a release agent, a dispersion liquid of resin particles S described below, and, if necessary, an aqueous medium at a temperature equal to or higher than the melting point of the release agent, using a disperser such as a homogenizer, a high-pressure disperser, or an ultrasonic disperser. The heating temperature during dispersion is preferably the melting point of the release agent or higher and 80°C or higher, more preferably 85°C or higher, even more preferably 90°C or higher, and is preferably 100°C or lower, more preferably 98°C or lower, even more preferably 96°C or lower.

[0080] The release agent particle dispersion can be obtained using a surfactant, but is preferably obtained by mixing the release agent and resin particles. By preparing the release agent particles using the release agent and resin particles, the release agent particles are stabilized by the resin that constitutes the resin particles, and it becomes possible to disperse the release agent in an aqueous medium without using a surfactant. It is believed that the release agent particle dispersion has a structure in which a large number of resin particles adhere to the surfaces of the release agent particles. The resin constituting the resin particles 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. For details about the release agent particle dispersion and the composite resin D, see JP 2024-25642 A. Alternatively, the aforementioned amorphous polyester resin A may be used.

[0081] Volume median particle size D of release agent particles 50 From the viewpoint of obtaining uniform aggregated particles by aggregation, the particle size is preferably 0.05 μm or more, more preferably 0.2 μm or more, even more preferably 0.4 μm or more, and is preferably 1 μm or less, more preferably 0.8 μm or less, even more preferably 0.6 μm or less. The CV value of the release agent particles is preferably 10% or more, more preferably 20% or more, and is preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. Volume median particle size D of release agent particles 50 The CV value is measured by the method described in the Examples.

[0082] <Surfactants> In the step of aggregating the resin particles, when dispersions of the respective particles are mixed to prepare a mixed dispersion, the process may be carried out in the presence of a surfactant from the viewpoint of improving the dispersion stability of the resin particles, colorant particles, release agent particles, etc. 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 total amount used is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of resin particles, and is preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

[0083] <Flocculant> In the step of aggregating the resin particles, it is preferable to add an aggregating agent from the viewpoint of efficient aggregation. 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 aggregating property and obtaining uniform aggregated particles 1, inorganic aggregating agents 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.

[0084] For example, 5 to 50 parts by mass of the aggregating agent is added to 100 parts by mass of resin particles in a mixed dispersion containing resin particles, colorant particles, and release agent particles at a temperature of 0° C. to 40° C., and the resin particles, colorant particles, and release agent particles are aggregated in an aqueous medium to obtain aggregated particles 1. Furthermore, from the viewpoint of promoting aggregation, it is preferable to increase the temperature of the dispersion after adding the aggregating agent.

[0085] Methods for stopping aggregation include cooling the dispersion, adding an aggregation terminator, and diluting the dispersion. From the viewpoint of reliably preventing unnecessary aggregation, a method of stopping aggregation by adding an aggregation terminator is preferred. Furthermore, when a step of aggregating shell resin particles is included for the purpose of producing a toner having a core-shell structure, the step of aggregating shell resin particles may be performed when aggregated particles 1 have grown to an appropriate particle size without terminating the aggregation.

[0086] Volume median particle size D of agglomerated particles 1 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 8 μm or less, even more preferably 7 μm or less. Volume median particle size D of agglomerated particles 1 50is measured by the method described in the Examples.

[0087] The toner manufacturing method of the present invention may include a step of adhering and aggregating shell resin particles to the obtained aggregated particles 1 as cores to obtain aggregated particles 2. By including the step of aggregating shell resin particles, toner particles having a core-shell structure can be obtained. The shell resin particles are preferably made of an amorphous resin, more preferably an amorphous polyester resin. The shell resin particle dispersion liquid can be obtained by the same method as the above-mentioned method for producing the resin particle dispersion liquid. From the viewpoint of low-temperature fixability of the toner, the mass ratio of the shell resin particles to the mass of the aggregated particles 1 [shell resin particles / aggregated particles 1] is preferably 1 / 99 or more, more preferably 3 / 97 or more, even more preferably 5 / 95 or more, and is preferably 25 / 75 or less, more preferably 20 / 80 or less, even more preferably 15 / 85 or less. When the toner manufacturing method includes a step of aggregating shell resin particles, it is preferable to stop the aggregation in the step when the aggregated particles 2 have grown to a particle size appropriate for toner particles, and a method of stopping the aggregation by adding an aggregation terminator is preferred.

[0088] <Aggregation stopper> The aggregation terminator is preferably a surfactant, more preferably an anionic surfactant. Examples of anionic surfactants include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, polyoxyalkylene alkyl ether sulfates, aryl sulfonates, and aryl sulfonic acid formalin condensates. 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 0.5 parts by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of aggregated particles immediately before the addition of the aggregation terminator, from the viewpoint of reliably preventing unnecessary aggregation, and is preferably 10 parts by mass or less, from the viewpoint of reducing residue in the toner.

[0089] <Fusion process> In the fusion step, for example, aggregated particles 1 or aggregated particles 2 are fused in an aqueous medium. By fusion, the particles contained in the aggregated particles are fused together to obtain fused particles. In the fusion step, from the viewpoint of improving the fusion properties of the aggregated particles and improving the low-temperature fixability of the toner, the aggregated particles are maintained at a temperature equal to or higher than the glass transition temperature of the resin having the highest glass transition temperature among the amorphous resins contained in the aggregated particles. From the viewpoint of improving the fusion properties of the aggregated particles and improving the productivity of the toner, the holding temperature when fusing the aggregated particles is preferably at least 2°C higher, more preferably at least 3°C ​​higher, and even more preferably at least 5°C higher than the glass transition temperature of the resin having the highest glass transition temperature among the amorphous resins, 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 having the highest glass transition temperature among the amorphous resins. In this case, the time for maintaining the temperature at or above the glass transition temperature of the amorphous resin is preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, from the viewpoint of improving the low-temperature fixability of the toner, 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.

[0090] The volume median particle size D of the fused particles obtained by fusion 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 8 μm or less, even more preferably 7 μm or less.

[0091] 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 even more preferably 0.980 or less. The fusion is preferably terminated after the desired circularity is reached. The circularity is measured by the method described in the Examples.

[0092] <Post-processing process> A post-treatment step may be carried out after the fusion step, and the fused particles are isolated to obtain toner particles. Since the fused particles obtained in the fusion step are present in an aqueous medium, it is preferable to first carry out 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. At this time, it is preferable to remove the added surfactant, so washing with an aqueous medium at a temperature below the cloud point of the surfactant is preferable. Washing is preferably performed multiple times. Next, it is preferable to carry out drying. Examples of the drying method include vacuum constant temperature drying, vibration fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0093] [Melt-kneading method] In the present invention, the melt-kneading method involves, for example, uniformly mixing amorphous resin A, resin C, a colorant, and, if necessary, additives such as a release agent and a charge control agent in a mixer such as a Henschel mixer, and then melt-kneading the mixture in an internal kneader, a single-screw or twin-screw extruder, an open-roll kneader, etc. The mixture is then cooled, pulverized, and classified to obtain toner particles.

[0094] [External additives] As described above, it is preferable to use the toner of the present invention in which an external additive has been added to the surface of the toner particles. Examples of external additives include fine particles of inorganic materials such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and fine particles of polymers such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. One type of external additive may be used alone, or two or more types may be used. Two or more types of hydrophobic silica having different particle sizes may also be used. When the surface treatment of the toner particles is performed using an external additive, the amount of the external additive added is 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, relative to 100 parts by mass of the toner particles.

[0095] Toners are used to develop electrostatic images in electrophotographic printing. Toners can be used, for example, as a one-component developer or as a two-component developer mixed with a carrier. [Example]

[0096] 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 "alkylene oxide (X)" and the like, the number X in parentheses means the average number of moles of alkylene oxide added.

[0097] [Measurement method] [Softening point, crystallinity index, melting point 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 extruded from a nozzle 1 mm in diameter and 1 mm in length. The plunger depression distance 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" (TA Instruments Japan), 0.02 g of sample was weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The temperature was then held for 1 minute, after which the temperature was raised to 180°C at a rate of 10°C / min and the calorific value was measured. The temperature of the endothermic peak with the largest area was defined as the endothermic maximum peak temperature (1), and the crystallinity index was calculated by (softening point (°C)) / (endothermic maximum peak temperature (1) (°C)). (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (TA Instruments Japan), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled from 200°C to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the calorific value was measured. The temperature of the endothermic peak with the largest peak area was taken as the maximum endothermic peak temperature (2). For crystalline resins, this peak temperature was taken as the melting point. For amorphous resins, if a peak was observed, the peak temperature was used; if no peak was observed but a step was observed, the glass transition temperature was taken as the temperature at the intersection of the tangent line showing the maximum slope of the curve at the step and an extension of the baseline on the low-temperature side of the step.

[0098] [Acid value of resin] The acid value of the resin was measured according to the neutralization titration method described in JIS K 0070:1992, except that the measurement solvent was chloroform.

[0099] [Ester group concentration of resin] Calculated using the above formula.

[0100] [Melting point of release agent] Using a differential scanning calorimeter "Q100" (TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled from 200°C 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.

[0101] [Volume median particle diameter D of resin particles, release agent particles, and colorant particles 50 and CV value) (1) Measuring device: Laser diffraction particle size measuring instrument "LA-920" (manufactured by Horiba Ltd.) (2) Measurement conditions: Put the 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 and volume average particle size D V The CV value (particle size distribution) was calculated according to the following formula. CV value (%) = (standard deviation of particle size distribution) / volume average particle size D V ) x 100

[0102] [Solid Content Concentration of Resin Particle Dispersion, Colorant Particle Dispersion, and Release Agent Particle Dispersion] Using an infrared moisture meter "FD-230" (Kett Electric Laboratory Co., Ltd.), the water 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 min / fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0103] [Volume median particle size of agglomerated particles D 50 〕 Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III version 3.51" (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, and the volume median particle size D is calculated from the particle size distribution. 50 asked for.

[0104] [Circularity of Fused Particles and Toner Particles] Measurement equipment: Flow particle image analyzer "FPIA-3000" (Sysmex Corporation) Preparation of dispersion: A dispersion of fused particles or toner particles was prepared by diluting it with deionized water so that the solid content concentration was 0.001 to 0.05% by mass. Measurement mode: HPF measurement mode

[0105] [Volume median particle size D of toner particles 50 〕 The measuring instrument, aperture diameter, analysis software, and electrolyte are all set to the volume median particle diameter D 50 The same material as that used in the measurement was used. Dispersion: Polyoxyethylene lauryl ether "EMULGEN (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance): 13.6) was dissolved in the electrolyte to obtain a dispersion with a concentration of 5% by mass. Dispersion conditions: 10 mg of a measurement sample of toner particles was added to 5 mL of the dispersion liquid, and the mixture was dispersed for 1 minute using an ultrasonic disperser. Thereafter, 25 mL of the electrolyte solution was added, and the mixture was further dispersed for 1 minute using the 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 asked for.

[0106] [Resin manufacturing] [Production of amorphous resin] Production Example A1 (Production of Resin A-1) A 10 L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 4,367 g of propylene oxide (2.2) adduct of bisphenol A, 1,098 g of terephthalic acid, 32 g of tin(II) di(2-ethylhexanoate), and 3.2 g of gallic acid (3,4,5-trihydroxybenzoic acid) were added. The reaction system was heated to 235°C under a nitrogen atmosphere while stirring, and then maintained at 235°C for 5 hours. The pressure in the flask was then reduced and maintained at 8 kPa for 1 hour. The pressure was then returned to atmospheric pressure, cooled to 160°C, and a mixture of 1,070 g of styrene, 267 g of stearyl methacrylate, 144 g of acrylic acid, and 160 g of dibutyl peroxide was added dropwise to the reaction system over 3 hours while maintaining the temperature at 160°C. The reaction system was then maintained at 160°C for 30 minutes, then heated to 200°C. The pressure in the flask was then reduced to 8 kPa and maintained at this temperature for 1 hour. The pressure was then returned to atmospheric pressure, cooled to 190°C, and 174 g of fumaric acid, 378 g of sebacic acid, 240 g of trimellitic anhydride, and 3.2 g of 4-tert-butylcatechol were added. The temperature was then raised to 210°C at a rate of 10°C / hr, and the reaction was continued at 4 kPa until the softening point shown in Table 1 was reached, yielding Resin A-1 (composite resin). The physical properties are shown in Table 1.

[0107] Manufacturing Example D1 (Manufacturing of Resin D-1) A 10 L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 3450 g of a propylene oxide (2.2) adduct of bisphenol A, 655 g of terephthalic acid, 24 g of tin(II) di(2-ethylhexanoate), and 2.4 g of gallic acid (3,4,5-trihydroxybenzoic acid) were added. Under a nitrogen atmosphere, the reaction system was heated to 235°C while stirring and maintained at 235°C for 5 hours. The pressure inside the flask was then reduced and maintained at 8 kPa for 1 hour. After returning to atmospheric pressure, the flask was cooled to 160°C, and a mixture of 2133 g of styrene, 533 g of stearyl methacrylate, 114 g of acrylic acid, and 320 g of dibutyl peroxide was added dropwise over 3 hours while maintaining the temperature at 160°C. The reaction system was then maintained at 160°C for 30 minutes, then heated to 200°C, and the pressure inside the flask was further reduced to 8 kPa and maintained at 8 kPa for 1 hour. After returning to atmospheric pressure, the system was cooled to 190°C, 582 g of succinic acid was added, and the temperature was raised to 210°C at a rate of 10°C / hr. The reaction was then continued at 4 kPa until the softening point shown in Table 1 was reached, yielding Resin D-1 (composite resin). The physical properties are shown in Table 1.

[0108] [Table 1]

[0109] [Production of Crystalline Polyester Resin C] Manufacturing Example C1 (Manufacturing of Resin C-1) The alcohol component, carboxylic acid component, and radical polymerization inhibitor shown in Table 2 were placed in a 10-L four-neck flask equipped with a thermometer, stainless steel stirring rod, downflow condenser, and nitrogen inlet tube, and the temperature was raised to 200°C over 8 hours in a nitrogen atmosphere using a mantle heater. The esterification catalyst shown in Table 2 was then added, and the reaction was continued at 8 kPa until the softening point shown in Table 2 was reached, yielding Resin C-1). The physical properties are shown in Table 2.

[0110] Manufacturing Examples C2 and C3 (Manufacturing of Resins C-2 and C-3) Resins C-2 and C-3 were obtained in the same manner as in Production Example C1, except that the alcohol component, carboxylic acid component, radical polymerization inhibitor, and esterification catalyst shown in Table 2 were used in the amounts shown in Table 2. Physical property values ​​are shown in Table 2.

[0111] Manufacturing Example C4 (Manufacturing of Resin C-4) The alcohol and carboxylic acid components shown in Table 2 were placed in a 10 L four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube, and the temperature was raised to 200°C over 8 hours in a nitrogen atmosphere in a mantle heater. An esterification catalyst was then added, and the reaction was continued at 8 kPa until the softening point shown in Table 2 was reached, yielding Resin C-4. The physical properties are shown in Table 2.

[0112] Manufacturing example C51 (manufacturing of resin C-51) Resin C-51 was obtained in the same manner as in Production Example C1, except that the alcohol component, carboxylic acid component, radical polymerization inhibitor, and esterification catalyst shown in Table 2 were used in the amounts shown in Table 2. Physical property values ​​are shown in Table 2.

[0113] Manufacturing example C52 (manufacturing of resin C-52) Resin C-52 was obtained in the same manner as in Production Example C4, except that the alcohol component, carboxylic acid component, and esterification catalyst shown in Table 2 were used in the amounts shown in Table 2. Table 2 shows the physical property values.

[0114] [Table 2]

[0115] [Production of resin particle dispersion] Production Example X1 (Production of Resin Particle Dispersion X-1) 240 g of Resin A-1, 60 g of Resin C-1, 300 g of methyl ethyl ketone, and 59 g of deionized water were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resins were dissolved over 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 relative 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, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min, resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous resin dispersion. Thereafter, while stirring at 280 r / min (peripheral speed 63 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion X-1. The volume median particle diameter D of the resulting resin particles was 50 and CV values ​​are shown in Table 3.

[0116] Production examples X2~X6, X51, X52 (manufacture of resin particle dispersions X-2~X-6, X-51, X-52) Resin particle dispersions X-2 to X-6, X-51, and X-52 were obtained in the same manner as in Production Example X1, except that the type and amount of resin used were changed as shown in Table 3. The volume median particle diameter D 50 and CV values ​​are shown in Table 3.

[0117] [Table 3]

[0118] Production Example Y1 (Production of Resin Particle Dispersion Y-1) 200 g of Resin D-1 and 200 g of methyl ethyl ketone were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 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 relative 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 induce phase inversion emulsification. While maintaining the temperature at 73°C, the methyl ethyl ketone was removed under reduced pressure to obtain an aqueous resin dispersion. The aqueous dispersion was then cooled to 30°C while stirring at 280 r / min, and deionized water was added to obtain a solids concentration of 20% by mass to obtain Resin Particle Dispersion Y-1. The volume median particle diameter of the resin particles was 0.09 μm, and the CV value was 23%.

[0119] [Production of release agent particle dispersion] Production Example W1 (Production of Release Agent Particle Dispersion W-1) 120 g of deionized water, 86 g of resin particle dispersion Y-1, and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) were added to a 1 L beaker, and the mixture was melted by maintaining the temperature at 90 to 95°C and stirred to obtain a molten mixture. The obtained molten mixture was further 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% by mass, thereby obtaining release agent particle dispersion W-1. The volume median particle diameter D of the release agent particles 50 The particle size was 0.47 μm and the CV value was 27%.

[0120] [Production of colorant particle dispersion] Production Example E1 (Production of Colorant Particle Dispersion E-1) In a 1 L beaker, 75 g of the yellow pigment "Paliotol Yellow D1155" (BASF Color & Effects Japan, CI Pigment Yellow 185), 25 g of polyoxyethylene (13) distyrenated phenyl ether "Emulgen A-60" (Kao Corporation, nonionic surfactant), and 300 g of deionized water were mixed and dispersed using a homomixer "TKAGI HOMOMIXER 2M-03" (Tokushu Kika Kogyo Co., Ltd.) at room temperature (20°C) with a stirring blade rotation speed of 8000 rpm for 1 hour. The mixture was then passed through a "Microfluidizer M-110EH" (Microfluidics) at a pressure of 150 MPa for 15 passes. The mixture was then passed through a 200-mesh filter and deionized water was added to obtain colorant particle dispersion E-1. The physical properties are shown in Table 4.

[0121] Production Examples E2, E51, and E52 (Production of Colorant Particle Dispersions E-2, E-51, and E-52) Colorant particle dispersions E-2, E-51, and E-52 were obtained in the same manner as in Production Example E1, except that the yellow pigment was changed as shown in Table 4. Table 4 shows the physical properties of the dispersions.

[0122] [Table 4]

[0123] [Toner manufacturing] Example 1 (Production of Toner 1) 500 g of resin particle dispersion X-1, 35 g of release agent particle dispersion W-1, 44 g of colorant particle dispersion E-1, and 1.1 g of a 15% by mass aqueous solution of sodium dodecylbenzenesulfonate "Neopelex G-15" (Kao Corporation, anionic surfactant) were placed in a 3 L four-neck flask equipped with a reflux condenser, a stirrer, and a thermocouple, and mixed at 25° C. Next, while stirring the resulting mixture, a solution prepared by dissolving 40 g of ammonium sulfate in 570 g of deionized water and adding a 4.8% by mass aqueous solution of potassium hydroxide to adjust the pH to 8.4 was added dropwise over 10 minutes at 25° C., and the mixture was then heated to 61° C. over 2 hours to measure the volume median particle diameter D of the aggregated particles. 50 The temperature was maintained at 61°C until the particle size reached 6.3 µm, thereby obtaining a dispersion of aggregated particles 1. To the obtained dispersion of aggregated particles 1, an aqueous solution prepared by mixing 15 g of sodium polyoxyethylene lauryl ether sulfate "EMAL E-27C" (manufactured by Kao Corporation, anionic surfactant, effective concentration 27% by mass), 280 g of deionized water, and 40 g of a 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 maintained at 75°C for 30 minutes. After that, 15 g of a 0.1 mol / L aqueous sulfuric acid solution was added, and the mixture was maintained at 75°C for an additional 15 minutes. Thereafter, 15 g of a 0.1 mol / L aqueous sulfuric acid solution was again added, and the mixture was maintained at 75°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles in which aggregated particles 1 were fused. The obtained dispersion of fused particles was cooled to 30°C, and the dispersion was subjected to suction filtration to separate the solid content, which was then washed with deionized water at 25°C and suction filtrated at 25°C for 2 hours. Thereafter, the solid content was vacuum dried at 33°C for 24 hours using a vacuum constant temperature dryer "DRV622DA" (manufactured by ADVANTEC Corporation) to obtain toner particles 1. The volume median particle diameter D of the obtained toner particles 1 was 50 The diameter was 6.0 μm and the circularity was 0.970. 100 parts by mass of toner particles 1 were mixed with 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 0.04 μm) and 1 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Corporation, number average particle size: 0.012 μm) in a Henschel mixer, and the mixture was passed through a 150 mesh sieve to obtain toner 1. The obtained toner 1 was evaluated as follows. The evaluation results of toner 1 are shown in Table 5.

[0124] [Toner Evaluation] [Evaluation of pencil hardness of printed coating film (fastness of printed coating film)] Polypropylene film labels, OPP50C (manufactured by Lintec Corporation), cut to A4 size were printed using a commercially available printer, Microline (registered trademark) 5400 (manufactured by Oki Electric Industry Co., Ltd.), with the toner adhesion amount on the film label being 0.43 to 0.45 mg / cm. 2 A solid image of the above was printed without fixing, leaving a 5mm margin from the top edge of an A4-sized film label, and a length of 50mm. Next, the same printer was prepared with a temperature-adjustable fixing unit modified, and the fixing unit temperature was set to 100°C. Toner 1 was fixed at a speed of 3 seconds per sheet in portrait A4 format to form a printed coating, and a label print was obtained (equivalent to 20 sheets per minute in portrait A4 format). The pencil hardness of the printed coating film of the resulting label print was measured in accordance with JIS K5600-5-4 using a pencil scratch coating hardness tester ("D-NP (model number)" manufactured by Toyo Seiki Seisakusho Co., Ltd.) and pencils for pencil scratch value testing (6B, 5B, 4B, 3B, 2B, B, HB, F, H) (manufactured by Mitsubishi Pencil Co., Ltd.). The printed coating film was scratched five times with pencils of each hardness in the order of 6B, 5B, 4B, 3B, 2B, B, HB, F, and H. The hardest pencil hardness that did not produce scratches three or more times was taken as the pencil hardness of the printed coating film of the label print. "H" indicates the best pencil hardness (fastness of the printed coating film).

[0125] Examples 2 to 7 and Comparative Examples 1 to 4 (Production of Toners 2 to 7 and 51 to 54) Toners 2 to 7 and 51 to 54 were produced in the same manner as in Example 1, except that the types of resin particle dispersion and colorant particle dispersion used were changed as shown in Table 5. The evaluation results of toners 2 to 7 and 51 to 54 are shown in Table 5.

[0126] [Table 5]

[0127] Example 8 (Production of Toner 8) 80 parts by weight of Resin A-1, 20 parts by weight of Resin C-1, 5 parts by weight of colorant PY185 ("Paliotol Yellow D1155", manufactured by BASF Color & Effects Japan, Ltd., CI Pigment Yellow 185), 1 part by weight of charge control agent "LR-147" (manufactured by Nippon Carlit Co., Ltd.), and 4 parts by weight of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) as a mold release agent were thoroughly mixed in a Henschel mixer and then melt-kneaded using a co-rotating twin-screw extruder with a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The screw rotation speed was 200 r / min, the heating temperature inside the screw was set to 90°C, the temperature of the kneaded material was 140°C, the kneaded material was fed at a rate of 10 kg / h, and the average residence time was approximately 18 seconds. The resulting melt-kneaded product was cooled and coarsely crushed, then crushed in a jet mill, and classified using an air classifier (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain a volume median particle diameter D 50 The volume median particle diameter D of the toner particles 8 was 6.5 μm. 50 The diameter was 6.5 μm and the circularity was 0.948. 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 0.04 μm) and 1 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Corporation, number average particle size: 0.012 μm) were placed in a Henschel mixer per 100 parts by mass of toner particles 8, and the mixture was stirred and passed through a 150 mesh sieve to obtain toner 8. The evaluation results of the obtained toner 8 are shown in Table 6.

[0128] [Table 6]

[0129] The printed coating film obtained from the toner produced using the amorphous resin A, resin C, and yellow pigment specified in the present invention has a pencil hardness of 2B or more, and is excellent in fastness (Examples 1 to 8). In contrast, the toners of Comparative Examples 1 and 2 used a yellow pigment with an NH group content of less than 6.0 mmol / g, and therefore the printed coating film obtained from these toners had a pencil hardness of "3B," and sufficient fastness of the printed coating film was not obtained. The toner of Comparative Example 3 used a crystalline polyester resin with an ester group concentration of more than 9.0 mmol / g, and therefore the printed coating film had a pencil hardness of "6B," and the fastness of the printed coating film was poor. The toner of Comparative Example 4 used a crystalline polyester resin produced without using an aliphatic dicarboxylic acid having four carbon atoms, and therefore the printed coating film had a pencil hardness of "3B," and sufficient fastness of the printed coating film was not obtained.

Claims

1. A toner for developing electrostatic images, comprising toner particles containing an amorphous resin A, a crystalline polyester resin C, and a colorant, the crystalline polyester resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less; The colorant has -NH- and -NH ２ The total number of the pigments is divided by the molecular weight to obtain an NH group amount, and the pigment contains a yellow pigment having an NH group amount of 6.0 mmol / g or more. Toner for developing electrostatic images.

2. 2. The toner for developing electrostatic images according to claim 1, wherein the yellow pigment is at least one selected from the group consisting of isoindoline pigments and benzimidazolone pigments.

3. 3. The toner for developing electrostatic images according to claim 1, wherein the yellow pigment is at least one selected from C. I. Pigment Yellow 185 and C. I. Pigment Yellow 180.

4. 3. The toner for developing electrostatic images according to claim 1, wherein the aliphatic dicarboxylic acid having 4 carbon atoms contains fumaric acid.

5. 3. The toner for developing electrostatic images according to claim 1, wherein the carboxylic acid component of the crystalline polyester resin C further contains a monocarboxylic acid having 6 to 24 carbon atoms.

6. 3. The toner for developing electrostatic images according to claim 1, wherein the content of the colorant in the toner particles is 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the crystalline polyester resin C.

7. 3. The toner for developing electrostatic images according to claim 1, wherein a mass ratio of the crystalline polyester resin C to the amorphous resin A (crystalline polyester resin C / amorphous resin A) is 5 / 95 or more and 40 / 60 or less in the toner particles.

8. A method for producing a toner for developing electrostatic images, the method comprising the steps of aggregating and fusing resin particles, the resin particles containing an amorphous resin A and a crystalline polyester resin C in the same or different particles, and a colorant in an aqueous medium, the crystalline polyester resin C contains a polycondensate of an alcohol component and a carboxylic acid component containing 70 mol% or more of an aliphatic dicarboxylic acid having 4 carbon atoms, and has an ester group concentration of 6.0 mmol / g or more and 9.5 mmol / g or less; The colorant has -NH- and -NH ２ The total number of the pigments is divided by the molecular weight to obtain an NH group amount, and the pigment contains a yellow pigment having an NH group amount of 6.0 mmol / g or more. A method for producing a toner for developing electrostatic images.

Images