Toner for developing electrostatic images

Abstract

To provide an electrophotographic toner excellent in bending resistance of printed matter.SOLUTION: The toner for developing electrostatic images includes a binder resin containing: a silicone-modified polyester resin that is a reaction product of raw monomer components including a carboxylic acid component having a valence of at least two, an alcohol component having a valence of at least two, and a modified silicone; a crystalline polyester resin; and a styrene-based resin, the binder resin containing at least 45 mass% and 80 mass% or less of the styrene-based resin.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, and the like. [Background technology]

[0002] In recent years, with the growth of the print-on-demand market, there has been an increasing demand for faster electrophotographic technology. To address this demand for higher speeds, toners with excellent low-temperature fixability are being used, allowing the toner to be fixed to paper with less energy. However, reducing the viscosity of toners to meet this demand for higher speeds has resulted in problems such as poor separation between the fixing device and the toner image, and poor hot offset resistance.

[0003] In order to solve these problems, for example, Patent Document 1 describes a toner for developing electrostatic images that includes toner particles, the toner particles having a core-shell structure, and the shell portion contains a silicone-modified amorphous composite resin that includes a polyester resin segment, an addition polymerization resin segment that includes a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment.

[0004] Furthermore, Patent Document 2 describes a toner for developing electrostatic images, which contains toner particles having a core-shell structure, and the shell portion contains a silicone-modified amorphous composite resin that includes a polyester resin segment, an addition polymerization resin segment containing a structural unit derived from a styrene-based compound, and a polyorganosiloxane segment. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-54636 [Patent Document 2] Japanese Patent Publication No. 2023-11500 Summary of the Invention [Problem to be solved by the invention]

[0006] However, while the toners described in Patent Documents 1 and 2 have excellent hot offset resistance, there is room for improvement in the bending resistance of printed matter. The present invention relates to a toner for developing electrostatic images that has excellent resistance to folding of printed matter. [Means for solving the problem]

[0007] The present invention relates to the following [1]. [1] A toner for developing electrostatic images, comprising a silicone-modified polyester resin, which is a reaction product of raw material monomer components including a divalent or higher alcohol component, a divalent or higher carboxylic acid component, and a modified silicone, a crystalline polyester resin, and a binder resin including a styrene resin, The binder resin contains the styrene-based resin in an amount of 45% by mass or more and 80% by mass or less. Toner for developing electrostatic images. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a toner for electrophotography that provides excellent bending resistance to printed matter. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Electrophotographic toner] An electrophotographic toner (hereinafter also simply referred to as "toner") according to one embodiment of the present invention comprises a silicone-modified polyester-based resin, which is a reaction product of raw material monomer components including a divalent or higher alcohol component, a divalent or higher carboxylic acid component, and a modified silicone, a crystalline polyester-based resin, and a binder resin containing a styrene-based resin, and the binder resin contains 45% by mass or more and 80% by mass or less of the styrene-based resin. According to the above-mentioned configuration, it is possible to provide a toner for electrophotography that has excellent bending resistance for printed matter.

[0010] The reason why the present invention is effective is not clear, but is thought to be as follows. In order to maintain the low-temperature fixability of a toner, a technique of using a styrene-based resin and a crystalline polyester-based resin in combination as a binder resin composition for a toner is widely used. However, styrene-based resins and crystalline polyester-based resins have low compatibility, and domains containing the crystalline polyester-based resin are generated in a printed image. When the printed image is folded, the printed image breaks from these domains, which causes a problem of deterioration in the folding resistance of the printed matter. Furthermore, in order to maintain the hot offset resistance of the toner, a technique has been used in which a silicone-modified resin is incorporated into the shell portion of a toner having a core-shell structure. In this case, the silicone-modified resin is localized in the outer layer of the toner, making it difficult for it to affect the crystalline polyester-based resin in the toner. The binder resin contained in the toner of the present invention contains a silicone-modified polyester-based resin throughout the binder resin, in addition to a styrene-based resin and a crystalline polyester-based resin. Therefore, the silicone segments of the silicone-modified polyester-based resin improve the dispersibility of the crystalline polyester-based resin in the printed material, thereby reducing the size of domains containing the crystalline polyester-based resin that occur in the printed image and improving the bending resistance of the printed material. Furthermore, during the recrystallization process of the crystalline polyester-based resin during printing, the crystalline polyester-based resin recrystallizes while incorporating the structure derived from the modified silicone in the silicone-modified polyester-based resin, making the domains containing the crystalline polyester-based resin themselves less likely to crack, thereby improving the bending resistance of the printed material.

[0011] The definitions of various terms used in this specification are shown below. The crystallinity of a resin is expressed by the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter (DSC), i.e., the crystallinity index defined as "softening point (°C) / maximum endothermic peak temperature (°C)". The term "crystalline resin" refers to a resin having a crystallinity index of 0.6 or more and 1.4 or less. The term "amorphous resin" refers to a resin in which no endothermic peak is observed by differential scanning calorimetry (DSC), or, if an endothermic peak is observed, the resin has a crystallinity index of less than 0.6 or more than 1.4. The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the endothermic peaks observed under the conditions of the measurement method described in the Examples. The crystallinity of the resin can be adjusted by the types and ratios of raw material monomers, and production conditions (e.g., reaction temperature, reaction time, cooling rate), etc. The term "alkylene oxide adduct of bisphenol A" refers to the entire structure in which alkylene oxide is added to 2,2-bis(4-hydroxyphenyl)propane. The term "carboxylic acid component" includes not only carboxylic acids but also their anhydrides and alkyl esters having 1 to 3 carbon atoms. In other words, in this specification, when only the name of a carboxylic acid is mentioned, it is understood that the mention also includes the anhydrides and alkyl esters having 1 to 3 carbon atoms of the carboxylic acid. Volume median particle size (D 50 )" is the particle size at which the cumulative volume frequency calculated by volume fraction is 50% calculated from the smallest particle size.

[0012] [Silicone-modified polyester resin] The silicone-modified polyester resin is a reaction product of raw material monomer components including a divalent or higher alcohol component, a divalent or higher carboxylic acid component, and a modified silicone. The silicone-modified polyester resin may be a silicone-modified amorphous composite resin containing a polyester resin segment, which is a reaction product of raw material monomer components including a divalent or higher alcohol component, a divalent or higher carboxylic acid component, and a modified silicone, and a styrene resin segment containing a structural unit derived from a styrene compound.

[0013] (dihydric or higher alcohol components) Examples of the dihydric or higher alcohol component include diols and trihydric or higher polyhydric alcohols. Examples of the diols include aromatic diols, aliphatic diols, and alicyclic diols. The dihydric or higher alcohol component may be used alone or in combination of two or more.

[0014] Examples of aromatic diols include alkylene oxide adducts of bisphenol A. From the viewpoint of obtaining a toner that provides excellent bending resistance to printed matter, the alkylene oxide adducts of bisphenol A are preferably those represented by the following formula (I):

[0015] [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. Examples of alkylene oxide adducts of bisphenol A include propylene oxide adducts of bisphenol A and ethylene oxide adducts of bisphenol A. These may be used alone or in combination. Among these, propylene oxide adducts of bisphenol A, ethylene oxide adducts of bisphenol A, and combinations thereof are preferred. The content of the aromatic diol in the alcohol component is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[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, and 1,12-dodecanediol. 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. These alcohol components may be used alone or in combination of two or more.

[0017] (divalent or higher carboxylic acid component) Examples of divalent or higher carboxylic acid components include dicarboxylic acids and trivalent or higher polycarboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids and aliphatic dicarboxylic acids, and 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 50 mol% or more, more preferably 55 mol% or more, even more preferably 60 mol% or more, and is preferably 95 mol% or less, more preferably 92 mol% or less, even more preferably 90 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 acid substituted with a hydrocarbon group having from 1 to 20 carbon atoms. Examples of succinic acid substituted with a hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, succinic acid and succinic acid substituted with a hydrocarbon group having from 1 to 20 carbon atoms are preferred, succinic acid substituted with an alkenyl group is more preferred, and succinic acid substituted with a branched alkenyl group is even more preferred. The amount of the aliphatic dicarboxylic acid in the carboxylic acid component is preferably 5 mol% or more, more preferably 8 mol% or more, even more preferably 10 mol% or more, and is preferably 50 mol% or less, more preferably 45 mol% or less, even more preferably 40 mol% or less.

[0019] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, such as trimellitic acid.

[0020] The equivalent ratio (COOH groups / OH groups) of the carboxyl groups (COOH groups) of the carboxylic acid component to the hydroxyl groups (OH groups) of the alcohol component 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] (Modified silicone) The modified silicone includes at least one selected from modified silicones having a repeating unit represented by formula (1) and a repeating unit represented by formula (2), and modified silicones having a repeating unit represented by formula (2) and a structure represented by formula (3). From the viewpoint of obtaining a toner having excellent folding resistance for printed matter, the modified silicone is preferably a modified silicone having a repeating unit represented by formula (1) and a repeating unit represented by formula (2), i.e., a modified silicone having at least one functional group selected from an amino group, a carboxy group, an epoxy group, and a carbinol group, and more preferably a modified silicone having an amino group. Furthermore, from the viewpoint of obtaining a toner having excellent folding resistance for printed matter, a modified silicone having a functional group in a side chain is preferred. That is, a modified silicone having an amino group in a side chain is even more preferred.

[0022] [ka] [In formula (1), each R is independently a hydrocarbon group having from 1 to 6 carbon atoms, each R' is independently an alkylene group having from 1 to 10 carbon atoms, a is 1 or 0, each X is independently a group containing an amino group, a carboxy group, an epoxy group, or a hydroxy group, and * is a bonding site.]

[0023] [ka] [In formula (2), each R is independently a hydrocarbon group having 1 to 6 carbon atoms, and * represents a bonding site.]

[0024] *-SiR 3-b (R''-X) b (3) [In formula (3), each R is independently a hydrocarbon group having from 1 to 6 carbon atoms, each R" is independently an alkylene group having from 1 to 10 carbon atoms, b is an integer of from 1 to 3, each X is independently a group containing an amino group, a carboxy group, an epoxy group, or a hydroxy group, and * is a bonding site to the repeating unit represented by formula (2)]

[0025] The repeating units represented by formula (1) and the repeating units represented by formula (2) may be random or block, and are not particularly limited.

[0026] In formulas (1) to (3), the hydrocarbon group of R has 6 or less carbon atoms, preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, and even more preferably 1 carbon atom. Examples of hydrocarbon groups for R include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, and phenyl groups. Among these, methyl is preferred.

[0027] In formula (1) and formula (3), the alkylene groups of R' and R'' have 10 or less carbon atoms, preferably 8 or less, more preferably 5 or less, even more preferably 4 or less, still more preferably 3 or less, and preferably 1 or more. Examples of the alkylene group for R' and R'' include a methanediyl group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, an n-propane-1,3-diyl group, and an n-propane-1,2-diyl group. Among these, a methanediyl group, an ethane-1,2-diyl group, an n-propane-1,3-diyl group, and an n-propane-1,2-diyl group are preferred.

[0028] Each X is independently a group having an amino group, a carboxy group, an epoxy group, or a hydroxy group, and is preferably an amino group, a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group. The hydroxyalkyloxy group may have multiple hydroxy groups, and the carboxyalkyloxy group may have multiple carboxy groups. Among these, from the viewpoint of reactivity with the carboxy group of a divalent or higher carboxylic acid, X is preferably a group having an amino group.

[0029] The modified silicone preferably contains 40 or less repeating units represented by formula (1), more preferably 20 or less, even more preferably 10 or less, and preferably 1 or more repeating units. The repeating units represented by formula (2) are contained in an amount of 500 or less, preferably 450 or less, more preferably 400 or less, and preferably 10 or more, preferably 30 or more, more preferably 50 or more.

[0030] The functional group equivalent weight of the modified silicone is preferably 300 g / mol or more, more preferably 500 g / mol or more, even more preferably 1,000 g / mol or more, even more preferably 2,000 g / mol or more, and is preferably 10,000 g / mol or less, more preferably 8,000 g / mol or less, even more preferably 6,000 g / mol or less. The functional group equivalent weight means the mass of the modified silicone per mole of the functional group.

[0031] The kinematic viscosity of the modified silicone is preferably 20 mm at 25° C. in order to obtain a toner that has excellent bending resistance of printed matter. 2 / s or more, preferably 50 mm 2 / s or more, more preferably 90 mm 2 / s or more, and preferably 20,000 mm 2 / s or less. The kinematic viscosity of the modified silicone may be a catalog value, or may be measured using, for example, a fully automatic micro kinematic viscometer (manufactured by Viscotec Co., Ltd.).

[0032] Examples of the modified silicones include modified silicones having amino groups on the side chains (commercially available products include "KF-864" and "KF-865" manufactured by Shin-Etsu Chemical Co., Ltd.), modified silicones having amino groups on both ends (commercially available products include "KF-8008" and "KF-8012" manufactured by Shin-Etsu Chemical Co., Ltd.), modified silicones having an amino group on one end; modified silicones having a carboxy group on the side chain (commercially available products include "X-22-3701E" manufactured by Shin-Etsu Chemical Co., Ltd. and "BY16-880" manufactured by Dow Corning Toray Co., Ltd.), modified silicones having carboxy groups on both ends (commercially available products include "X-22-162C" manufactured by Shin-Etsu Chemical Co., Ltd.), modified silicones having a carboxy group on one end (commercially available products include "X-22-3710" manufactured by Shin-Etsu Chemical Co., Ltd.), and modified silicones having an epoxy group on the side chain. Examples of such modified silicones include those having an epoxy group at one end (commercially available products include "X-22-163B" and "X-22-169B" manufactured by Shin-Etsu Chemical Co., Ltd.), those having an epoxy group at both ends (commercially available products include "X-22-173BX" manufactured by Shin-Etsu Chemical Co., Ltd.), those having a hydroxy group at the side chain (commercially available products include "X-22-4015" and "X-22-4039" manufactured by Shin-Etsu Chemical Co., Ltd.), those having a hydroxy group at both ends (commercially available products include "KF-6003" and "KF-6002" manufactured by Shin-Etsu Chemical Co., Ltd.), and those having a hydroxy group at one end (commercially available products include "X-22-170BX" and "X-22-170DX" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0033] When the modified silicone has a group containing an amino group, in the repeating unit represented by formula (1) and the structure represented by formula (3), *-(R') a Examples of the group represented by -X and the group represented by -(R''-X) include the following substituents 1a-1 to 1a-3.

[0034] [ka]

[0035] When the modified silicone is a modified silicone having a group containing a hydroxy group, in the repeating unit represented by formula (1) and the structure represented by formula (3), *-(R') a Examples of the group represented by -X and the group represented by -(R''-X) include the following substituents 1b-1 to 1b-3. Among these, the substituent 1b-1 or the substituent 1b-2 is preferred, and the substituent 1b-1 is more preferred.

[0036] [ka]

[0037] When the modified silicone is a modified silicone having a group containing an epoxy group, in the repeating unit represented by formula (1) and the structure represented by formula (3), X and Y are preferably a glycidyl group, a glycidyloxy group, and an alicyclic epoxy group, and *-(R') a Examples of the group represented by -X and the group represented by -(R''-X) include the following substituents 1b-4 to 1b-6. Among these, the substituent 1b-4 is preferred.

[0038] [ka]

[0039] When the modified silicone is a modified silicone having a group containing a carboxy group, in the repeating unit represented by formula (1) and the structure represented by formula (3), X and Y are preferably a carboxy group or a carboxyalkyloxy group, and *-(R') a Examples of the group represented by -X and the group represented by -(R''-X) include the following substituent 1b-7.

[0040] [ka]

[0041] In the silicone-modified polyester resin, the content of the structure derived from the modified silicone is preferably 2% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 22% by mass or less.

[0042] (styrene resin segment) When the silicone-modified polyester resin is a silicone-modified amorphous composite resin, the styrene-based resin segment preferably contains a structural unit derived from a styrene-based compound and 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 the styrene-based compound in the raw material monomers of the styrene-based resin segment is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less.

[0043] 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. Preferred are 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate, more preferred are 2-ethylhexyl acrylate and stearyl methacrylate, and even more preferred are 2-ethylhexyl acrylate. In addition, "(iso or tertiary)" and "(iso)" refer to both the presence and absence of these prefixes, and the absence of these prefixes indicates normal. In addition, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid.

[0044] The content of (meth)acrylic acid ester in the raw material monomers of the styrene-based 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 30% by mass or less, more preferably 25% by mass or less, even more preferably 20% by mass or less. The total amount of the styrene compound and (meth)acrylic acid ester in the raw material monomers of the styrene 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.

[0045] The silicone-modified amorphous composite resin preferably has a structural unit derived from a bireactive monomer that is bonded to a polyester resin segment and a styrene-based resin segment via a covalent bond. 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 structural unit derived from the bireactive monomer is preferably 1 molar part or more, more preferably 3 molar parts or more, and preferably 15 molar parts or less, more preferably 10 molar parts or less, relative to 100 molar parts of the alcohol component of the polyester resin segment of the silicone-modified amorphous composite resin.

[0046] The content of the polyester resin segment in the silicone-modified amorphous composite resin is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 78% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 82% by mass or less. The mass of the polyester resin segment is the mass including the structure derived from the modified silicone and the structural unit derived from the bireactive monomer. The content of the styrene resin segment in the silicone-modified amorphous composite resin is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 18% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, even more preferably 22% by mass or less. The content of the modified silicone-derived structure in the silicone-modified amorphous composite resin is preferably 4% by mass or more, more preferably 6% by mass or more, even more preferably 8% by mass or more, and is preferably 18% by mass or less, more preferably 15% by mass or less, even more preferably 12% by mass or less. The content of bireactive monomer-derived structural units in the silicone-modified amorphous composite resin is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, and is preferably 2% by mass or less, more preferably 1.5% by mass or less, even more preferably 1% by mass or less.

[0047] (Method of manufacturing silicone-modified polyester resin) The silicone-modified polyester resin is preferably produced by a method including, for example, step A of polycondensing raw material monomers including a divalent or higher carboxylic acid component, a divalent or higher alcohol component, and a modified silicone, and, if necessary, step B of addition polymerizing raw material monomers for a styrene-based resin segment and a bireactive monomer. When producing by a method including step B, step B may be performed after step A, step A may be performed after step B, or step A and step B may be performed simultaneously. A preferred method is to subject a part 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 the carboxy group of the bireactive monomer or the constituent moiety derived from the bireactive monomer.

[0048] In step A, if necessary, polycondensation may be carried out using an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropoxybis(triethanolaminate) in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the divalent or higher carboxylic acid component, the divalent or higher alcohol component, and the modified silicone; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) 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 the polycondensation reaction, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and is preferably 260°C or lower, more preferably 250°C or lower.

[0049] Examples of the radical polymerization initiator for the addition polymerization in step B include peroxides such as di-tert-butyl 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 styrene-based 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. The reaction may be carried out in an inert gas atmosphere.

[0050] (Physical properties of silicone-modified polyester resin) From the viewpoint of obtaining a toner that exhibits excellent folding resistance in printed matter, the softening point of the silicone-modified polyester resin is preferably 70°C or higher, more preferably 80°C or higher, and even more preferably 85°C or higher, and is 130°C or lower, preferably 120°C or lower, and more preferably 115°C or lower. The glass transition temperature of the silicone-modified polyester resin 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 70°C or lower, even more preferably 60°C or lower. The acid value of the silicone-modified polyester resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 25 mgKOH / g or less. The weight average molecular weight of the silicone-modified polyester resin is preferably 3,000 or more, more preferably 3,500 or more, and even more preferably 4,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less. The softening point, glass transition temperature, acid value, and weight average molecular weight of the silicone-modified polyester resin can be adjusted appropriately 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 silicone-modified polyester resins are used in combination, the softening point, glass transition temperature, acid value, and weight-average molecular weight of the resulting mixture preferably fall within the aforementioned ranges.

[0051] From the viewpoint of obtaining a toner that has excellent folding resistance for printed matter, the content of the silicone-modified polyester resin in the binder resin is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 33% by mass or less.

[0052] In the binder resin, the mass of the modified silicone-derived structure in the silicone-modified polyester resin is 3 parts by mass or more, preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and 45 parts by mass or less, preferably 35 parts by mass or less, more preferably 33 parts by mass or less, relative to 100 parts by mass of the crystalline polyester resin described below, from the viewpoint of obtaining a toner that has excellent folding resistance of printed matter.

[0053] [Crystalline polyester resin] The crystalline polyester resin is, for example, a polycondensate of an alcohol component and a carboxylic acid component. Alternatively, the crystalline polyester resin may be a crystalline composite resin containing a polyester resin segment that is a polycondensate of an alcohol component and a carboxylic acid component, and a styrene resin segment that contains a structural unit derived from a styrene compound.

[0054] (alcohol content) The alcohol component preferably comprises an α,ω-aliphatic diol. The α,ω-aliphatic diol preferably has 2 or more carbon atoms, and preferably 16 or less, more preferably 14 or less, and 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, ethylene glycol, 1,4-butanediol, and 1,12-dodecanediol are preferred.

[0055] The amount of the 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, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0056] The alcohol component may contain other alcohol components different from the α,ω-aliphatic diol. Examples of other alcohol components include aliphatic diols other than α,ω-aliphatic diols, such as 1,2-propylene glycol and neopentyl glycol; aromatic diols, such as alkylene oxide adducts of bisphenol A; and trihydric or higher alcohols, such as glycerin, pentaerythritol, and trimethylolpropane. These alcohol components may be used alone or in combination.

[0057] (carboxylic acid component) The carboxylic acid component preferably comprises an aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid preferably has 4 or more carbon atoms, more preferably 6 or more carbon atoms, and preferably has 18 or less carbon atoms, more preferably 16 or less carbon atoms. Examples of aliphatic dicarboxylic acids include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid and tetradecanedioic acid are preferred. These carboxylic acid components may be used alone or in combination of two or more.

[0058] The amount of the aliphatic dicarboxylic acid in the carboxylic acid component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0059] The carboxylic acid component may contain other carboxylic acid components different from the aliphatic dicarboxylic acid. Examples of other carboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polycarboxylic acids having three or more carboxylic acids. These carboxylic acid components may be used alone or in combination of two or more.

[0060] 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.

[0061] (styrene resin segment) When the crystalline polyester resin is a crystalline composite resin, the styrene resin segment preferably contains a structural unit derived from a styrene compound and is an addition polymer of raw material monomers containing a styrene compound. Examples of raw material monomers for the styrene-based resin include the same raw material monomers as those listed for the (styrene-based resin segment) in the silicone-modified polyester-based resin, and the preferred ranges are also the same.

[0062] (Method for producing crystalline polyester resin) The crystalline polyester resin can be obtained, for example, by polycondensation of an alcohol component and a carboxylic acid component. The polycondensation conditions are, for example, as described above in (Method for producing silicone-modified polyester resin), and the method may include step A and, if necessary, step B. Examples of the esterification catalyst and esterification co-catalyst used in the method for producing a crystalline polyester resin include the esterification catalyst and esterification co-catalyst used in step A described above (Method for producing a silicone-modified polyester resin), and the amounts used may be the same as those described above. The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and preferably 230°C or lower, more preferably 220°C or lower, even more preferably 210°C or lower.

[0063] When the crystalline polyester resin is a crystalline composite resin, examples of the radical polymerization initiator for the addition polymerization in step B include peroxides such as di-tert-butyl 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 styrene-based 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.

[0064] (Physical properties of crystalline polyester resin) The softening point of the crystalline polyester resin is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher, and is preferably 120°C or lower, more preferably 115°C or lower, and even more preferably 110°C or lower. The melting point of the crystalline polyester resin is preferably 60°C or higher, more preferably 70°C or higher, even more preferably 75°C or higher, and preferably 110°C or lower, more preferably 100°C or lower, even more preferably 95°C or lower. The acid value of the crystalline polyester resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 25 mgKOH / g or less. The weight average molecular weight of the crystalline polyester resin is preferably 5,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 30,000 or less.

[0065] The softening point, melting point, acid value, and weight-average molecular weight of the crystalline polyester resin can be appropriately adjusted by adjusting the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate. These values ​​are determined by the method described in the Examples below. When two or more crystalline polyester resins are used in combination, it is preferable that the softening point, melting point, acid value, and weight-average molecular weight of the resulting mixture are within the aforementioned ranges.

[0066] From the viewpoint of obtaining a toner that has excellent bending resistance for printed matter, the content of the crystalline polyester resin in the binder resin is preferably 2% by mass or more, more preferably 5% by mass or more, even more preferably 8% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 12% by mass or less.

[0067] [Styrene-based resin] The styrene-based resin is an addition polymer of raw material monomers containing a styrene-based compound. Examples of raw material monomers for the styrene-based resin include the same raw material monomers as those listed above (for the styrene-based resin segment).

[0068] The styrene-based compound is preferably at least one selected from styrene, α-methylstyrene, β-methylstyrene, methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, and methoxystyrene, more preferably styrene. The content of styrene compounds in the raw material monomers of the styrene resin is preferably 65% ​​by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less.

[0069] The raw material monomer for the styrene-based resin other than the styrene-based compound is preferably a (meth)acrylic acid ester, more preferably an alkyl (meth)acrylate, and even more preferably n-butyl (meth)acrylate. The content of alkyl (meth)acrylate in the raw material monomers of the styrene-based 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 35% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less.

[0070] (Method of producing styrene-based resin) The styrene-based resin may be produced, for example, by the method including step B shown above (Method for producing silicone-modified polyester-based resin). Examples of radical polymerization initiators used in the method for producing a styrene-based resin include peroxides such as dicumyl peroxide and di-tert-butyl 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 styrene-based resin. 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.

[0071] (Physical properties of styrene-based resins) The softening point of the styrene resin is preferably 70°C or higher, more preferably 80°C or higher, and even more preferably 90°C or higher, and is preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 125°C or lower. The glass transition temperature of the styrene resin is preferably 30°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, even more preferably 60°C or lower. The softening point, glass transition temperature, and acid value of the styrene-based resin can be appropriately adjusted by the type and amount 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 styrene-based resins are used in combination, it is preferable that the softening point, glass transition temperature and acid value of the resulting mixture are each within the above-mentioned ranges.

[0072] From the viewpoint of obtaining a toner that has excellent bending resistance for printed matter, the content of the styrene resin in the binder resin is 45% by mass or more, preferably 47% by mass or more, more preferably 48% by mass or more, and 80% by mass or less, preferably 79% by mass or less, more preferably 78% by mass or less.

[0073] [Other resins] The binder resin may contain a resin other than the silicone-modified polyester resin, the crystalline polyester resin, and the styrene-based resin. Examples of other resins include amorphous polyester resins. Examples of amorphous polyester resins include polyester resins made of polycondensates and modified polyester resins. Examples of modified polyester resins include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing a polyester resin segment, a styrene-based resin segment, and a bireactive monomer-derived structural unit that bonds the polyester resin segment and the styrene-based resin segment via a covalent bond.

[0074] [Core-shell toner] The toner particles contained in the electrostatic image developing toner of the present invention may have a core-shell structure. In this case, it is preferable that the core part of the core-shell structure contains the binder resin. The shell portion of the core-shell structure contains an amorphous resin. Examples of amorphous resins include amorphous polyester resins and styrene resins. The amorphous polyester resin is not particularly limited as long as it contains a polycondensate of an alcohol component and a carboxylic acid component, and examples thereof include polyester resins made of polycondensates 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-polymerized resin segments. The resin contained in the shell portion is preferably a composite resin, and is preferably an amorphous composite resin containing a polyester resin segment, a styrene-based resin segment, and a bireactive monomer-derived structural unit that bonds the polyester resin segment and the styrene-based resin segment via a covalent bond. Examples of such composite resins include amorphous composite resins containing the polyester resin segment and the styrene-based resin segment listed above in [Silicone-modified polyester-based resin], and a bireactive monomer-derived structural unit that bonds them via a covalent bond.

[0075] When the toner particles have a core-shell structure, the ratio of the total mass of the resin in the shell portion to the total mass of the resin in the core portion (resin in shell portion / resin in core portion) is preferably 3 / 97 or more, more preferably 5 / 95 or more, even more preferably 7 / 93 or more, from the viewpoint of obtaining a toner that has excellent bending resistance in printed matter, and is preferably 20 / 80 or less, more preferably 15 / 85 or less, even more preferably 12 / 88 or less.

[0076] The toner particles may contain additives such as a colorant, a release agent, 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. (coloring agent) As the colorant, any dye, pigment, etc. that is used as a colorant for toner can be used. Examples of the dye include azine dyes, anthraquinone dyes, perinone dyes, and rhodamine dyes. The pigment may be either an inorganic pigment or an organic pigment, and examples of the inorganic pigment include carbon black and metal oxides, while examples of the organic pigment include azo pigments, diazo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, etc. These may be used alone or in combination of two or more. From the viewpoint of improving the image density of the toner, the amount of the colorant is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 6 parts by mass or less, relative to 100 parts by mass of the total of the binder resins.

[0077] (mold 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, and oxides thereof; ester waxes such as carnauba wax, montan wax, and deacidified waxes thereof, and fatty acid ester wax; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts, and these may be used alone or in combination of two or more. The amount of the release agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 5 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 12 parts by mass or less, relative to 100 parts by mass of the total binder resin.

[0078] (charge control agent) Examples of the charge control agent include chromium-based azo dyes, iron-based azo dyes, aluminum azo dyes, salicylic acid metal complexes, etc. These may be used alone or in combination of two or more. From the viewpoint of the charging stability of the toner, the amount of the charge control agent is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 3 parts by mass or less, more preferably 1.5 parts by mass or less, relative to 100 parts by mass of the total of the binder resins.

[0079] [Toner manufacturing method] The toner may be obtained by any known method such as a melt-kneading method, an emulsion phase inversion method, a polymerization method, or an emulsion aggregation method, but from the viewpoint of productivity, the emulsion aggregation method is preferred. When a toner is produced by the emulsion phase inversion method, the process includes a step (1) of aggregating particles containing a binder resin in an aqueous medium to obtain aggregated particles, and a step (2) of fusing the obtained aggregated particles to obtain toner particles.

[0080] [Step (1)] Step (1) is a step of aggregating particles containing a binder resin (hereinafter also referred to as "binder resin particles") in an aqueous medium to obtain aggregated particles.

[0081] (Method for producing particles containing binder resin) The binder resin particles contain a silicone-modified polyester resin, a crystalline polyester resin, and a styrene resin in the same or different resin particles. Hereinafter, a method for producing resin particles X containing a silicone-modified polyester resin in the particles will be described. The binder resin particles may be produced as an aqueous dispersion of resin particles. The aqueous medium is preferably one containing water as a main component. From the viewpoint of improving the dispersion stability of the binder resin particle dispersion and from the viewpoint of environmental friendliness, the water content in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, even more preferably 100% by mass. Deionized water or distilled water is preferred as the water. Examples of components other than water that may be contained in the aqueous medium include water-soluble organic solvents such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having a total carbon number of 3 to 5, such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran. Among these, methyl ethyl ketone is preferred.

[0082] Dispersion can be carried out using known methods, but is preferably carried out by phase inversion emulsification, such as a method in which an aqueous medium is added to an organic solvent solution of a silicone-modified polyester resin or a molten silicone-modified polyester resin to effect phase inversion emulsification.

[0083] The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the silicone-modified polyester resin, and examples thereof include methyl ethyl ketone. It is preferable to add a neutralizing agent to the organic solvent solution of the silicone-modified polyester resin. Examples of the neutralizing agent include basic substances. Examples of the basic substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. The degree of neutralization of the silicone-modified polyester resin contained in the resin particles X is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and is preferably 100 mol% or less, more preferably 90 mol% or less, even more preferably 80 mol% or less. The degree of neutralization of the silicone-modified polyester resin contained in the resin particles X can be determined by the following formula. Degree of neutralization (mol %)=[{weight (g) of neutralizing agent added / equivalent weight of neutralizing agent} / [{weighted average acid value (mg KOH / g) of silicone-modified polyester resin constituting resin particle X × weight (g) of silicone-modified polyester resin constituting resin particle X} / (56 × 1000)]] × 100

[0084] Phase inversion emulsification is carried out by gradually adding an aqueous medium to an organic solvent solution of the silicone-modified polyester resin or a molten silicone-modified polyester resin while stirring. From the viewpoint of improving the dispersion stability of the resin particles X, the temperature of the organic solvent solution when the aqueous medium is added is preferably equal to or higher than the glass transition temperature of the silicone-modified polyester resin constituting the resin particles X, more preferably equal to or higher than 50°C, even 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.

[0085] After the phase inversion emulsification, if necessary, the organic solvent may be removed from the obtained dispersion by distillation, etc. In this case, the amount of the remaining organic solvent in the dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass.

[0086] Volume median particle size D of resin particles X in the dispersion 50 From the viewpoint of obtaining a toner that can produce high-quality images, the particle size is preferably 50 nm or more, more preferably 80 nm or more, and is preferably 300 nm or less, more preferably 200 nm or less, and even more preferably 150 nm or less. Volume median particle size D 50is determined by the method described in the Examples below. Resin particles Y containing a crystalline polyester resin, resin particles Z containing a styrene resin, resin particles XY containing a silicone-modified polyester resin and a crystalline polyester resin, resin particles XZ containing a silicone-modified polyester resin and a styrene resin, resin particles YZ containing a crystalline polyester resin and a styrene resin, and resin particles XYZ containing a silicone-modified polyester resin, a crystalline polyester resin, and a styrene resin can all be produced in accordance with the above-mentioned method. The volume median particle diameter D of resin particles Y, resin particles Z, resin particles XY, resin particles XZ, resin particles YZ, and resin particles XYZ 50 The preferred range of is the same as the range described above.

[0087] (Agglomeration of binder resin particles) In step (1), the binder resin particles produced above are aggregated to obtain aggregated particles. When aggregating the binder resin particles, additives such as a colorant, a release agent, and a charge control agent may be mixed with an aqueous dispersion of the binder resin particles to obtain aggregated particles. The additives are preferably mixed as an aqueous dispersion with the aqueous dispersion of the binder resin particles, and the mixing is carried out by a conventional method.

[0088] (surfactant) In step (1), the binder resin particle dispersion and the additive dispersion are mixed to prepare a mixed dispersion, and the mixture may be prepared in the presence of a surfactant in order to improve the dispersion stability of the binder resin particles and the additives. Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers; anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and cationic surfactants such as quaternary salts. When a surfactant is used in the dispersion of binder resin particles, the amount of each type of surfactant used is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less, relative to 100 parts by mass of binder resin particles. When a surfactant is used in the dispersion of the additive, the amount used is, for each type of surfactant, preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 18 parts by mass or less, even more preferably 15 parts by mass or less, per 100 parts by mass of the additive.

[0089] [Flocculant] In the step (1), it is preferable to add a flocculant from the viewpoint of efficient flocculation. Examples of the flocculant include cationic surfactants such as quaternary salts, organic flocculants such as polyethyleneimine, and inorganic flocculants. Examples of the inorganic flocculant include inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and divalent or higher metal complexes. From the viewpoint of improving the coagulation properties and obtaining uniformly coagulated particles, inorganic coagulants having a valence of 1 to 5 are preferred, inorganic metal salts having a valence of 1 to 2 and inorganic ammonium salts are more preferred, inorganic metal salts are even more preferred, and calcium chloride is even more preferred.

[0090] In step (1), for example, 0.2 to 5 parts by mass of a flocculant per 100 parts by mass of the total amount of resin is added to a mixed dispersion containing binder resin particles and additives at 0 to 40° C., and the binder resin particles and additives are aggregated in an aqueous medium to obtain aggregated particles. Furthermore, from the viewpoint of promoting aggregation, it is preferable to increase the temperature of the dispersion after adding the flocculant.

[0091] The aggregation may be stopped when the aggregated particles grow to a suitable particle size for toner particles. Methods for stopping aggregation include a method of cooling the dispersion, a method of adding an aggregation terminator, a method of diluting the dispersion, etc. From the viewpoint of reliably preventing unnecessary aggregation, a method of stopping aggregation by adding an aggregation terminator is preferred.

[0092] [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, and polyoxyalkylene alkyl ether sulfates. 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, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin in the binder resin particles, from the viewpoint of reliably preventing unnecessary aggregation, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, from the viewpoint of reducing residue in the toner.

[0093] Volume median particle size of agglomerated particles D 50 is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 7 μm or less.

[0094] When producing toner particles having a core-shell structure, a step (step (1')) may be included after step (1) and before step (2) in which shell resin particles containing an amorphous resin are allowed to adhere to the aggregated particles (aggregated particles 1) obtained in step (1) to obtain aggregated particles 2. By including step (1'), toner particles having a core-shell structure can be obtained. Here, examples of the amorphous resin used for the shell resin particles include the polyester resin segments and styrene resin segments listed above in [Silicone-modified polyester resin], and amorphous composite resins consisting of structural units derived from bireactive monomers that bond these via covalent bonds. The shell resin particles can be obtained by the same method as for the binder resin particles described above. Furthermore, when the toner manufacturing method includes step (1'), it is preferable to terminate the aggregation of aggregated particles 2 in step (1') when they have grown to a particle size appropriate for toner particles, and a method of terminating the aggregation by adding the above-mentioned aggregation terminator is preferred.

[0095] [Step (2)] In step (2), for example, the aggregated particles are fused in an aqueous medium. By fusion, the particles contained in the aggregated particles are fused together to obtain fused particles. In step (2), from the viewpoint of improving the fusion property of the aggregated particles, 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 resins contained in the aggregated particles. The holding temperature when fusing the aggregated particles is, from the viewpoint of improving the fusing properties of the aggregated particles and improving the productivity of the toner, preferably at least 5°C higher than the glass transition temperature of the resin, more preferably at least 10°C higher, and even more preferably at least 15°C higher, and is preferably not higher than 50°C higher, more preferably not higher than 45°C higher, and even more preferably not higher than 40°C higher than the glass transition temperature of the resin. In this case, the time for maintaining the temperature at or above the glass transition temperature of the resin is preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and 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.

[0096] The volume median particle size D of the fused particles obtained by fusion 50is 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.

[0097] 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.

[0098] (Post-processing process) A post-treatment step may be carried out after step (2), and toner particles can be obtained by isolating the fused particles. Since the fused particles obtained in step (2) are present in an aqueous medium, it is preferable to first 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 drying methods include vacuum low-temperature drying, vibration fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0099] [Toner particles] Volume median particle size D of toner particles 50 From the viewpoint of obtaining high-quality images and further improving the cleaning properties of the toner, the particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 7 μm or less. Volume median particle size D of toner particles 50 can be measured by the method described in the Examples.

[0100] [Electrostatic image developing toner] The toner for developing electrostatic images (hereinafter also simply referred to as toner) of the present invention can be the toner of the above toner particles as they are, but it is preferable to use the toner after adding a fluidizing agent or the like as an external additive to the surface of the toner particles.

[0101] (external additives) Examples of external additives include inorganic fine particles such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica and titanium oxide are 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 1.2 parts by mass or more, even more preferably 1.5 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.

[0102] 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]

[0103] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Physical properties of resins and the like were measured 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.

[0104] [Measurement method] <Resin softening point, crystallinity index, melting point and glass transition temperature> (1) Softening point Using a flow tester "CFT-500EX" (Shimadzu Corporation), 1 g of sample was heated at a temperature increase rate of 6°C / min, while applying a load of 1.96 MPa with the plunger, and extruding it 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 "Q-20" (TA Instruments Japan), 0.01-0.02 g of sample was weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The sample was then left to stand for 1 minute, after which it was heated 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 "Q-20" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated from room temperature (20°C) to 200°C at a heating rate of 10°C / min, and cooled from that temperature to 0°C at a heating rate of 10°C / min. The sample was then heated to 180°C at a heating rate of 10°C / min, and the endothermic peak was measured. Of the endothermic peaks observed, the temperature of the peak with the largest peak area was taken as the endothermic maximum peak temperature (2), and in the case of a crystalline resin, this peak temperature was taken as the melting point. In the case of an amorphous resin, when a peak is observed, the temperature of the peak is taken as the glass transition temperature. When a step is observed instead of a peak, 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 is taken as the glass transition temperature.

[0105] <Acid value of resin> The acid value of the resin was measured based on the neutralization titration method described in JIS K 0070: 1992. However, the measurement solvent was changed from the ethanol and ether mixed solvent specified in JIS K 0070: 1992 to a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)) for amorphous resins and to tetrahydrofuran for crystalline resins.

[0106] <Weight average molecular weight of resin> The molecular weight distribution was measured by gel permeation chromatography (GPC) obtained by the following method, and the weight average molecular weight of the resin was determined. (1) Preparation of sample solution The sample was dissolved in tetrahydrofuran in the case of amorphous resin, or in chloroform in the case of crystalline resin, at 25° C. to a concentration of 0.5 g / 100 mL. Next, this solution was filtered using a fluororesin filter "DISMIC-25JP" (manufactured by ADVANTEC) with a pore size of 0.2 μm in the case of amorphous resin, or a fluororesin filter "FP-200" (manufactured by Sumitomo Electric Industries, Ltd.) with a pore size of 2 μm in the case of crystalline resin, to remove insoluble matter, and a sample solution was obtained. (2) Molecular weight measurement The following measuring equipment and analytical column were used, and tetrahydrofuran was used as the eluent for amorphous resins, and chloroform was used for crystalline resins, with the flow rate being 1 mL per minute. The column was stabilized in a thermostatic bath at 40°C. 100 μL of sample solution was injected into the column and the measurement was performed. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. The calibration curve used here included several types of monodisperse polystyrene "A-500" (5.0 × 10 2 ), "A-1000" (1.01 x 10 3 ), "A-2500" (2.63 x 10 3 ), "A-5000" (5.97 x 10 3 ), "F-1" (1.02 x 10 4 ), "F-2" (1.81 x 10 4 ), "F-4" (3.97 x 10 4 ), "F-10" (9.64 x 10 4 ), "F-20" (1.90 x 10 5), "F-40" (4.27 x 10 5 ), "F-80" (7.06 x 10 5 ), "F-128" (1.09 x 10 6 ) (all manufactured by Tosoh Corporation) were used as standard samples. The numbers in parentheses indicate molecular weights. Measuring device: "HLC-8420CPC" (manufactured by Tosoh Corporation) (for amorphous resins) or "HLC-8320CPC" (manufactured by Tosoh Corporation) (for crystalline resins) Analytical column: "GMHXL" + "G3000HXL" (manufactured by Tosoh Corporation)

[0107] <Melting point of release agent> Using a differential scanning calorimeter "Q-20" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200°C at a heating rate of 10°C / min, and cooled from 200°C to -10°C at a heating rate of 5°C / min. Next, the sample was heated to 180°C at a heating rate of 10°C / min. The maximum endothermic peak temperature observed in the melting endothermic curve was taken as the melting point of the release agent.

[0108] <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 moisture content (mass%) of 5 g of the measurement sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, moisture content fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0109] <Volume median particle diameter D of resin particles, colorant particles, release agent particles, and charge control agent particles 50 > (1) Measuring device: Laser diffraction particle size measuring instrument "LA-920" (manufactured by Horiba Ltd.) (2) Measurement conditions: Put the sample dispersion in a 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 was measured.

[0110] <Average particle size of external additives> Using a field emission scanning electron microscope (FE-SEM) ("S-4800" manufactured by Hitachi High-Technologies Corporation), the particle sizes of 500 external additives (the average values ​​of the major and minor axes of each particle of the external additive) were measured, and the number average value of the particle sizes was taken as the average particle size of the external additives.

[0111] <Volume median particle size D of toner particles 50 > Volume median particle size D of toner particles 50 was measured as follows: Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (Beckman Coulter, Inc.) Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) was dissolved in the electrolyte solution to adjust the concentration to 5% by mass. Dispersion conditions: 10 mg of a measurement sample of dried toner particles was added to 5 mL of the dispersion, and the mixture was dispersed for 1 minute using an ultrasonic disperser (US-1 manufactured by SND Corporation, output 80 W). 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. 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.

[0112] [Production of Silicone-Modified Polyester Resin] Manufacturing example A1 (resin A-1) Of the raw material monomers for the silicone-modified polyester resin shown in Table 1, the raw material monomers other than succinic acid, the esterification catalyst, and the esterification co-catalyst 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 235°C over 2 hours in a nitrogen atmosphere in a mantle heater. After confirming that the reaction rate had reached 95% or more at 235°C, the mixture was cooled to 180°C. Succinic acid was then added, and the temperature was raised to 210°C over 2 hours. After reacting at 210°C for 1 hour, the reaction was continued under a reduced pressure of 40 kPa until the softening point shown in Table 1 was reached, yielding a silicone-modified polyester resin (Resin A-1). The reaction rate refers to the value of the amount of water produced by reaction (mol) / theoretical amount of water produced (mol) × 100. The physical properties are shown in Table 1.

[0113] Production Examples A2, A3, and A5 to A9 [Resins A-2, A-3, and A-5 to A-9] Silicone-modified polyester resins (resins A-2, A-3, and A-5 to A-9) were obtained in the same manner as in Production Example A1, except that the raw material monomers for the polyester resin segment and their amounts were changed as shown in Table 1. The physical properties are shown in Table 1.

[0114] Manufacturing example A4 (resin A-4) The raw material monomers for the polyester resin segment shown in Table 1 were placed in a 10 L four-neck flask equipped with a thermometer, stainless steel stirrer, downflow condenser, and nitrogen inlet tube. The temperature was raised to 160°C over 1 hour in a nitrogen atmosphere in a mantle heater. A mixed solution of the raw material monomers for the styrene resin segment, bireactive monomers, and radical polymerization initiator shown in Table 1 was then added dropwise over 1 hour. After maintaining the temperature at 160°C for 30 minutes, the temperature was raised to 200°C and the reaction was continued for another 1 hour under a reduced pressure of 8 kPa. After cooling to 160°C, an esterification catalyst and esterification cocatalyst were added, and the temperature was raised to 235°C over 2 hours. After 8 hours of reaction at 235°C, the reaction was continued under a reduced pressure of 40 kPa until the softening point shown in Table 1 was reached, yielding a silicone-modified polyester resin (Resin A-4). The physical properties are shown in Table 1.

[0115] The DDSA-C and modified silicones used in Production Examples A1 to A9 are as follows. DDSA-C: Dodecenyl succinic anhydride with a branched structure in the alkenyl group KF-865: Modified silicone "KF-865" (silicone with amino groups on the side chain, kinematic viscosity (25°C) = 110 mm 2 / s, functional group equivalent weight = 5,000 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) KF-8012: Modified silicone oil "KF-8012" (silicone with amino groups at both ends, kinematic viscosity (25°C) = 90 mm 2 / s, functional group equivalent weight = 2,200 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-162C: Modified silicone oil "X-22-162C" (silicone with carboxyl groups at both ends, kinematic viscosity (25°C) = 220 mm 2 / s, functional group equivalent 2,300 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) KF-6003: Modified silicone oil "KF-6003" (silicone with carbinol groups (hydroxyl groups) at both ends, kinematic viscosity (25°C) = 110 mm 2 / s, functional group equivalent weight = 2,500 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.) KF-1001: Modified silicone oil "KF-1001" (silicone with epoxy groups on the side chain, kinematic viscosity (25°C) = 17000mm 2 / s, functional group equivalent weight = 3,500 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0116] [Table 1]

[0117] [Production of amorphous polyester resin] Manufacturing example B1 (resin B-1) The raw material monomers for the polyester resin shown in Table 2, excluding succinic acid, the esterification catalyst, and the esterification co-catalyst, 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. The mixture was heated to 235°C over 2 hours in a nitrogen atmosphere in a mantle heater. After confirming that the reaction rate had reached 95% or more at 235°C, the mixture was cooled to 180°C. Succinic acid was then added, and the mixture was heated to 210°C over 2 hours. After reacting at 210°C for 1 hour, the mixture was reacted under a reduced pressure of 40 kPa until the softening point shown in Table 2 was reached, yielding an amorphous polyester resin (Resin B-1). The physical properties are shown in Table 2.

[0118] Manufacturing example B2 (resin B-2) The raw material monomers for the polyester resin segment shown in Table 2, except for succinic acid, 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. The temperature was raised to 160°C over 1 hour in a nitrogen atmosphere using a mantle heater. A mixed solution of the raw material monomers for the styrene-based resin segment, the bireactive monomer, and the radical polymerization initiator shown in Table 2 was then added dropwise over 1 hour. After maintaining the temperature at 160°C for 30 minutes, the temperature was raised to 200°C and the reaction was continued for 1 hour under a reduced pressure of 8 kPa. After cooling to 160°C, an esterification catalyst and an esterification co-catalyst were added, and the temperature was raised to 235°C over 2 hours. After confirming that the reaction rate had reached 95% or higher at 235°C, the mixture was cooled to 180°C. Succinic acid was then added, and the temperature was raised to 210°C over 2 hours. After reacting at 210° C. for 1 hour, the reaction was continued under reduced pressure of 40 kPa until the softening point shown in Table 2 was reached, yielding an amorphous polyester resin (Resin B-2).

[0119] [Table 2]

[0120] [Production of crystalline polyester resin] Production example C1 (resin C-1) Of the raw material monomers for the polyester resin segment shown in Table 3, all of the alcohol component and half of the carboxylic acid component were placed in a 10 L four-neck flask equipped with a thermometer, stainless steel stirrer, flow-through condenser, and nitrogen inlet tube. The mixture was heated from 130°C to 160°C over 5 hours in a nitrogen atmosphere in a mantle heater, and then reacted at 160°C. A mixed solution of the raw material monomers for the styrene resin segment, bireactive monomers, and radical polymerization initiator shown in Table 3 was then added dropwise over 1 hour. After maintaining the temperature at 160°C for 30 minutes, the remaining carboxylic acid component was added, and the temperature was raised from 130°C to 200°C over 8 hours. An esterification catalyst was then added, and the reaction was continued under a reduced pressure of 8 kPa until the acid value listed in Table 3 was reached, yielding a crystalline polyester resin (Resin C-1). The physical properties are shown in Table 3.

[0121] Manufacturing example C2 (resin C-2) The raw material monomers for the crystalline polyester resin shown in Table 3 were placed in a 10-liter four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube. The temperature was raised from 130°C to 200°C over 8 hours in a nitrogen atmosphere in a mantle heater, and the mixture was reacted at 200°C for 2 hours. An esterification catalyst was then added, and the reaction was continued under a reduced pressure of 8 kPa until the acid value shown in Table 3 was reached, yielding a crystalline polyester resin (Resin C-2). The physical properties are shown in Table 3.

[0122] Production example C3 (resin C-3) A crystalline polyester resin (Resin C-3) was obtained in the same manner as in Production Example C2, except that the raw material monomers for the crystalline polyester resin were changed as shown in Table 3. Table 3 shows the physical properties.

[0123] [Table 3]

[0124] [Production of styrene-based resin] Manufacturing example D1 (resin D-1) Two liters of xylene was placed in a 10-liter four-neck flask equipped with a thermometer, a stainless steel stirrer, a downflow condenser, a dropping funnel, and a nitrogen inlet tube. The raw material monomers and radical polymerization initiator for the styrene resin shown in Table 4 were placed in the dropping funnel attached to the four-neck flask. The xylene in the four-neck flask was then heated to 135°C under a nitrogen atmosphere, and the mixture of raw material monomers and radical polymerization initiator was added dropwise to the xylene from the dropping funnel over 1 hour. The temperature was then further raised to 200°C and maintained at 200°C for 2 hours. The mixture was then maintained under a reduced pressure of 8 kPa for 1 hour to remove the xylene, yielding a styrene resin (Resin D-1).

[0125] [Table 4]

[0126] [Production of Resin Particle Dispersion] Production Examples X1 to X9, and Production Examples X'1 and X'2 (Production of Silicone-Modified Polyester Resin Particle Dispersions X-1 to X-9, and Amorphous Polyester Resin Particle Dispersions X'-1 and X'-2) 100 g of the silicone-modified polyester resin or amorphous polyester resin shown in Table 5, 100 g of methyl ethyl ketone, and 16.7 g (4.5% by mass relative to 100 g of resin) of the anionic surfactant "EMAL E27C" (Kao Corporation, solids content 27% by mass) were added to a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and dissolved at 73°C for 2 hours. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution to achieve a degree of neutralization of 70 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes. While maintaining the temperature at 73°C, 475 g of deionized water was added over 77 minutes while stirring at 280 r / min (circumferential speed 88 m / min) to cause phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure, and water was further distilled off until the solids concentration reached 20% by mass. The aqueous dispersion was then cooled to 30°C while stirring at 280 r / min (circumferential speed 88 m / min), yielding aqueous dispersions in which silicone-modified polyester-based resin particles or amorphous polyester-based resin particles were dispersed in an aqueous medium (silicone-modified polyester-based resin particle dispersions X-1 to X-9, and amorphous polyester-based resin particle dispersions X'-1 and X'-2). The volume median particle diameter D of the particles in dispersions X-1 to X-9, and dispersions X'-1 and X'-2 was 50 The solid content concentrations of dispersions X-1 to X-9, and dispersions X′-1 and X′-2 are shown in Table 5.

[0127] [Table 5]

[0128] Production Examples Y1 to Y3 (Production of Crystalline Polyester Resin Particle Dispersions Y-1 to Y-3) Aqueous dispersions of crystalline polyester resin particles (crystalline polyester resin particle dispersions Y-1 to Y-3) were obtained in the same manner as in Production Example X1, except that the silicone-modified polyester resin was replaced with the crystalline polyester resin shown in Table 6. The volume median particle diameter D of the particles in dispersions Y-1 to Y-3 was 50 The solid content concentrations of dispersions Y-1 to Y-3 are shown in Table 6.

[0129] [Table 6]

[0130] Production Example Z1 (Production of styrene-based resin particle dispersion Z-1) In a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, 100 g of styrene-based resin D-1, 100 g of methyl ethyl ketone, and 16.7 g (4.5% by mass relative to 100 g of resin) of anionic surfactant "EMAL E27C" (Kao Corporation, solid content 27% by mass) were mixed at 25°C and dissolved at 73°C for 2 hours. The resulting solution was mixed with 475 g of deionized water at 73°C and dispersed for 30 minutes at 350 W using an ultrasonic homogenizer (Dr. Hielscher GmbH, trade name: "UP-400S"). The methyl ethyl ketone was then distilled off under reduced pressure at 70°C to obtain an aqueous dispersion of styrene-based resin particles (styrene-based resin particle dispersion Z-1). The volume median particle diameter D of the particles in dispersion Z-1 was 1.0 g. 50 The solid content of dispersion Z-1 is shown in Table 7.

[0131] [Table 7]

[0132] (Production of colorant dispersion) 50 g of copper phthalocyanine "ECB-301" (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), 5 g of nonionic surfactant "Emulgen 150" (polyoxyethylene lauryl ether, manufactured by Kao Corporation), and 200 g of deionized water were mixed and dispersed using an ultrasonic homogenizer (manufactured by Dr. Hielscher Co., Ltd., product name: "UP-400S") at an output of 350 W for 10 minutes to obtain a colorant dispersion containing colorant fine particles. The volume median particle diameter D of the colorant fine particles was 50 The particle diameter was 120 nm, and the solid content concentration of the colorant dispersion was 22% by mass.

[0133] (Production of release agent dispersion) 50 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point: 79°C), 5 g of cationic surfactant "Sanisol (registered trademark) B50" (manufactured by Kao Corporation, alkylbenzyldimethylammonium chloride, active ingredient 50% by mass), and 200 g of deionized water were heated to 95°C and dispersed for 30 minutes using an ultrasonic homogenizer (manufactured by Dr. Hielscher Co., Ltd., product name: "UP-400S") at an output of 350 W to obtain a release agent dispersion containing release agent particles. The volume median particle diameter D of the release agent particles 50 The particle diameter was 550 nm, and the solid content of the release agent dispersion was 22% by mass.

[0134] (Production of Charge Control Agent Dispersion) 50 g of the salicylic acid compound "Bontron E-84" (manufactured by Orient Chemical Industries Co., Ltd.) as a charge control agent, 5 g of "Emulgen 150" (polyoxyethylene lauryl ether, manufactured by Kao Corporation) as a nonionic surfactant, and 200 g of deionized water were mixed, and the mixture was dispersed for 10 minutes using glass beads and a sand grinder ("4G" manufactured by Aimex Co., Ltd.) to obtain a charge control agent dispersion containing charge control agent particles. The volume median particle diameter D of the charge control agent particles was 50 The particle diameter was 400 nm, and the solid content concentration of the charge control agent dispersion was 22% by mass.

[0135] Example 1 20 g of silicone-modified polyester resin particle dispersion X-1 (shown in Table 8) as the core resin, 20 g of crystalline polyester resin particle dispersion Y-1, 140 g of styrene resin particle dispersion Z-1, 8 g of colorant dispersion, 20 g of release agent dispersion, 2 g of charge control agent dispersion, and 127 g of deionized water were placed in a 2 L container, and 150 g of a 0.1 mass % calcium chloride aqueous solution at 20°C was added dropwise over 30 minutes while stirring at 100 r / min (circumferential speed 31 m / min) with an anchor stirrer. The temperature was then raised to 50°C while stirring. The volume median particle size (D 50Once the particle size (D) reached 5 μm, 20 g of amorphous polyester resin particle dispersion X'-2 was immediately added as a shell resin and dispersed by stirring. Subsequently, a dilution of 4.2 g of anionic surfactant "EMAL E27C" (Kao Corporation, solids content 27% by mass) diluted with 37 g of deionized water was added as an aggregation terminator to obtain aggregated particles 2. The temperature was then raised to 80°C and maintained at 80°C for 1 hour, after which heating was terminated. This allowed aggregated particles 2 to fuse together to form fused particles, which were then gradually cooled to 20°C and filtered through a 150-mesh (150 μm mesh) wire screen, followed by suction filtration, washing, and drying to obtain toner particles having a core-shell structure. Table 8 shows the volume median particle size (D) of the toner particles. 50 Shows. For 100 parts by weight of the resulting toner particles, 1 part by weight of hydrophobic silica "NAX-50" (manufactured by Nippon Aerosil Co., Ltd., average particle size 40 nm), 0.6 parts by weight of hydrophobic silica "R972" (manufactured by Nippon Aerosil Co., Ltd., average particle size 16 nm), and 0.5 parts by weight of titanium oxide "JMT-150IB" (manufactured by Teika Corporation, average particle size 15 nm) were added to a 10-liter Henschel mixer (manufactured by Nippon Coke and Engineering Co., Ltd.) equipped with ST and A0 stirring blades and stirred at 3000 rpm for 2 minutes to obtain a toner. The resulting toner was evaluated for folding resistance of printed matter using the following evaluation method. The results are shown in Table 8.

[0136] Examples 2 to 5, 7 to 9, 11 to 13 and Comparative Example 1 Toner particles and toner were produced in the same manner as in Example 1, except that the resin particle dispersion liquid shown in Table 8 was used as the core resin. 50 The evaluation results of the print and the bending resistance are shown in Table 8.

[0137] Example 6 Toner particles and a toner were produced in the same manner as in Example 1, except that 40 g of the silicone-modified polyester resin particle dispersion X-2 and 120 g of the styrene resin particle dispersion Z-1 were used. 50 The evaluation results of the print quality and bending resistance are shown in Table 8.

[0138] Example 10 Toner particles and a toner were produced in the same manner as in Example 1, except that 60 g of the silicone-modified polyester-based resin particle dispersion X-1 and 100 g of the styrene-based resin particle dispersion Z-1 were used. 50 The evaluation results of the print quality and bending resistance are shown in Table 8.

[0139] Example 14 22 g of silicone-modified polyester resin particle dispersion X-1 (shown in Table 8) as the core resin, 22 g of crystalline polyester resin particle dispersion Y-1, 156 g of styrene resin particle dispersion Z-1, 8 g of colorant dispersion, 20 g of release agent dispersion, 2 g of charge control agent dispersion, and 127 g of deionized water were placed in a 2 L container, and 150 g of a 0.1 mass % calcium chloride aqueous solution at 20°C was added dropwise over 30 minutes while stirring at 100 r / min (circumferential speed 31 m / min) with an anchor stirrer. The temperature was then raised to 50°C while stirring. The volume median particle diameter (D 50 The temperature was maintained at 50°C until the volume median particle diameter D was 5 μm. Thereafter, a diluted solution prepared by diluting 4.2 g of anionic surfactant "EMAL E27C" (Kao Corporation, solid content 27% by mass) with 37 g of deionized water was added as an aggregation terminator. The temperature was then raised to 80°C, and once it reached 80°C, the mixture was maintained at 80°C for 1 hour, after which the heating was terminated. This resulted in the formation of fused particles, which were then gradually cooled to 20°C, filtered through a 150 mesh (opening 150 μm) wire mesh, suction filtered, washed, and dried to obtain toner particles. Table 8 shows the volume median particle diameter D of the toner particles. 50 Shows. Thereafter, a toner was obtained in the same manner as in Example 1. The folding resistance of printed matter of the obtained toner was evaluated using the following evaluation method. The results are shown in Table 8.

[0140] Comparative Example 2 Toner particles and a toner were produced in the same manner as in Example 1, except that 80 g of the silicone-modified polyester-based resin particle dispersion X-1 and 80 g of the styrene-based resin particle dispersion Z-1 were used. 50The evaluation results of the print quality and bending resistance are shown in Table 8.

[0141] [Evaluation method] <Bending resistance> The toner was placed in a copy machine "AR-505" (manufactured by Sharp Corporation) whose fixing unit was modified to enable fixing outside the machine, and a printout was obtained in an unfixed state (print area: 20 cm × 20 cm, adhesion amount: 0.5 mg / cm 2 Then, the image was fixed at a fixing roll temperature of 160°C using a fixing machine (fixing speed 300mm / sec) adjusted to a total fixing pressure of 40kgf. 2 The maximum width of the image defect after folding inward for 30 seconds, reopening, and wiping off the damaged image with a soft cloth was used as an index of the folding resistance of the printed matter. The smaller the maximum width of the image defect, the better the folding resistance of the printed matter. 2 The results are shown in Table 8.

[0142] [Table 8]

[0143] As shown in Table 8, printed materials using the toners of Examples 1 to 14 had excellent bending resistance compared to Comparative Example 1, which did not contain a silicone-modified amorphous polyester resin, and Comparative Example 2, which had a low content of styrene resin.

Claims

1. A toner for developing electrostatic images, comprising a silicone-modified polyester-based resin, which is a reaction product of raw material monomer components including a divalent or higher alcohol component, a divalent or higher carboxylic acid component, and a modified silicone, a crystalline polyester-based resin, and a binder resin including a styrene-based resin, The binder resin contains the styrene-based resin in an amount of 45% by mass or more and 80% by mass or less. Toner for developing electrostatic images.

2. 2. The toner for developing electrostatic images according to claim 1, wherein the mass of the structure derived from the modified silicone in the silicone-modified polyester resin is 3 parts by mass or more and 45 parts by mass or less relative to 100 parts by mass of the crystalline polyester.

3. 2. The toner for developing electrostatic images according to claim 1, wherein the modified silicone is a modified silicone having at least one functional group selected from the group consisting of an amino group, a carboxy group, an epoxy group, and a carbinol group.

4. 2. The toner for developing electrostatic images according to claim 1, wherein the modified silicone is a modified silicone having an amino group.

5. 2. The toner for developing electrostatic images according to claim 1, wherein the modified silicone is a modified silicone having a functional group on a side chain.

6. 2. The toner for developing electrostatic images according to claim 1, wherein the silicone-modified polyester resin contains a constitutional unit derived from succinic acid substituted with an alkenyl group.

7. 7. The toner for developing electrostatic images according to claim 1, which has a core-shell structure, and the core portion contains the binder resin.

Images