Toner for developing electrostatic images

Abstract

This invention relates to a toner for electrostatic image development that can produce printed materials with high image density. [Solution] A toner for developing electrostatic images containing a binder resin and a colorant, wherein the binder resin contains amorphous polyester resin A containing a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and the colorant contains CI pigment red 254.

Description

[Technical Field]

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

[0002] In the field of electrophotography, the development of electrophotographic systems has created a demand for the development of electrophotographic toners that can handle higher image quality and higher speeds. To meet the demand for higher image quality, toners capable of producing printed materials with high image density are required.

[0003] Patent Document 1 describes a magenta toner that can cover the magenta color tone in process inks by using a specific pigment in combination, has high coloring power that covers a wide dynamic range from low to high density, has high saturation and brightness, excellent OHP transparency, and high lightfastness, and aims to provide a magenta toner that contains at least a binder resin and a colorant, characterized in that, in a spectral distribution diagram with the vertical axis as reflectance (%) and the horizontal axis as wavelength (nm), the reflectance obtained as toner in powder form is in the range of 5 to 10% at a wavelength of 425 nm and in the range of 65 to 70% at a wavelength of 675 nm. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-280278 [Overview of the project] [Problems that the invention aims to solve]

[0005] CI Pigment Red 254 has a bright color tone and high safety, making it desirable to use as a coloring agent to improve the performance of electrostatic image developing toners. Through our investigations, we have found that when CI Pigment Red 254 is used as a coloring agent in the magenta toner described in Patent Document 1, it cannot be sufficiently dispersed in the toner, and there is a risk that printed materials with excellent image density cannot be obtained using this toner. The present invention relates to a toner for electrostatic image development that can produce printed materials with high image density. [Means for solving the problem]

[0006] The inventors have discovered that by using a binder resin containing an amorphous polyester resin including segments derived from polyethylene terephthalate, it is possible to obtain a toner for electrostatic image development that can produce printed materials with high image density even when CI Pigment Red 254 is used as a coloring agent. The present invention relates to the following [1]. [1] A toner for developing electrostatic images containing a binder resin and a colorant, The aforementioned binder resin contains amorphous polyester resin A, which comprises a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate. The aforementioned coloring agent contains CI Pigment Red 254. Toner for developing electrostatic images. [Effects of the Invention]

[0007] According to the present invention, a toner for electrostatic image development is provided that can produce printed materials having high image density. [Modes for carrying out the invention]

[0008] [Toner for developing electrostatic images] The electrostatic image developing toner of the present invention (hereinafter also simply referred to as "toner") comprises a binder resin and a colorant. The binder resin contains amorphous polyester resin A (hereinafter also simply referred to as "resin A") which contains a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate (PET), and the colorant contains CI pigment red 254. Due to the above features, printed materials with high image density can be obtained using the toner of the present invention. While toner particles containing a binder resin and a colorant (hereinafter also simply referred to as "toner particles") can be used as is as the toner of the present invention, it is preferable to use toner particles that have been treated by adding a fluidizing agent or the like as an external additive to their surface.

[0009] The mechanism by which the toner of the present invention can be used to obtain printed materials with high image density is not yet clear, but it is thought to be as follows. C.I. Pigment Red 254 has a diketopyrrolopyrrole skeleton, is highly planar, and has chlorine atoms and amide bonds, so it is likely to aggregate due to intermolecular interactions. Therefore, C.I. Pigment Red 254 is not easily dispersed in toner particles, which is a factor that reduces the image density of printed matter produced using the resulting toner. In the present invention, the binder resin contains an amorphous polyester resin A containing PET segments. In the polycondensation reaction of an alcohol component, a carboxylic acid component, and PET, although PET undergoes transesterification while undergoing depolymerization and is incorporated into the polyester resin chain, it is not completely randomized, and molecular chains called PET segments exist in the resulting resin. Since the PET segments have a high ester group concentration and a certain length, they have a high affinity for C.I. Pigment Red 254, and the amorphous polyester resin A and C.I. Pigment Red 254 interact. This interaction relaxes the intermolecular interaction of C.I. Pigment Red 254. Therefore, the aggregation of C.I. Pigment Red 254 is suppressed, making it easier to disperse C.I. Pigment Red 254 in the amorphous polyester resin A, and enabling C.I. Pigment Red 254 to be incorporated more uniformly into the toner particles. As a result, it is considered that printed matter having a high image density can be obtained using the toner of the present invention. Note that the above mechanism regarding the effects of the present invention is an estimate, and the present invention is not limited thereto.

[0010] The definitions of various terms in this specification are shown below. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to generate carboxylic acids, and alkyl esters (alkyl groups having 1 to 3 carbon atoms) of each carboxylic acid. Whether the resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum peak temperature of endotherm in the measurement method described in the examples below (softening point (°C) / maximum peak temperature of endotherm (°C)). A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one where no endothermic peak is observed, or if an endothermic peak is observed, the crystallinity index is less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted according to the type and ratio of the raw material monomers, and manufacturing conditions such as reaction temperature, reaction time, and cooling rate. “(meth)acrylic acid” means at least one selected from acrylic acid and methacrylic acid. “(meth)acrylate” means at least one selected from acrylate and methacrylate.

[0011] 〔Toner particles〕 In the present invention, the toner particles contain a binder resin and a colorant. The toner particles may contain each component (essential components and optional components) such as a binder resin and a colorant alone or in combination of two or more. Also, the raw materials of each component contained in the toner particles such as an alcohol component and a carboxylic acid component may be used alone or in combination of two or more.

[0012] <Binder resin> (Amorphous polyester resin A) In the present invention, the binder resin contains an amorphous polyester resin A (hereinafter, also simply referred to as “resin A”) which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate. The content of the polycondensate of the alcohol component, the carboxylic acid component, and polyethylene terephthalate in resin A is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and 100% by mass or less, preferably 100% by mass, from the viewpoint of obtaining a printed matter with high image density. Examples of resin A include polyester resin, and composite resins containing polyester resin segments and addition polymerization resin segments.

[0013] Examples of alcohol components include aliphatic diols, alicyclic diols, alkylene oxide adducts of aromatic diols, and polyhydric alcohols of trihydric or higher hydricity. Among these, from the viewpoint of obtaining printed materials with high image density, at least one selected from aliphatic diols and alkylene oxide adducts of aromatic diols is preferred, with aliphatic diols being more preferred.

[0014] The aliphatic diol has two or more carbon atoms, preferably 16 or fewer, more preferably 12 or fewer, even more preferably 8 or fewer, and even more preferably 5 or fewer. 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, neopentyl glycol (2,2-dimethyl-1,3-propanediol), 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol. Ethylene glycol, 1,2-propanediol, 2,3-butanediol, and neopentyl glycol are preferred, and 1,2-propanediol and neopentyl glycol are more preferred.

[0015] Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and alkylene oxide adducts of hydrogenated bisphenol A with 2 to 4 carbon atoms (average number of added moles: 2 to 12).

[0016] The amount of constituent units derived from aliphatic diols is preferably 40 mol% or more, more preferably 60 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and 100 mol% or less, and preferably 100 mol%, of the constituent units derived from the alcohol component of resin A.

[0017] The amount of ethylene glycol constituent units derived from PET is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and 100 mol% or less, preferably 90 mol% or less, and more preferably 80 mol% or less, compared to the constituent units derived from aliphatic diols.

[0018] Examples of alkylene oxide adducts of aromatic diols include those of formula (I): [ka] An example of an alkylene oxide adduct of bisphenol A is given by the formula (wherein OR and RO are oxyalkylene groups, R is independently an ethylene or propylene group, x and y represent the average number of moles of alkylene oxide added, each being a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, 16 or less, preferably 8 or less, and more preferably 4 or less). Examples of alkylene oxide adducts of bisphenol A represented by formula (I) include propylene oxide adducts of 2,2-bis(4-hydroxyphenyl)propane and ethylene oxide adducts of 2,2-bis(4-hydroxyphenyl)propane. When the alcohol component contains an alkylene oxide adduct of bisphenol A, the amount of constituent units derived from the alkylene oxide adduct of bisphenol A is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less, of the constituent units derived from the alcohol component of resin A.

[0019] Examples of polyhydric alcohols with a valency of 3 or higher include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.

[0020] Examples of carboxylic acid components in resin A include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and polycarboxylic acids with a valency of three or more.

[0021] Examples of aromatic dicarboxylic acids include terephthalic acid, phthalic acid, and isophthalic acid. Examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, and azelaic acid. Examples of alicyclic dicarboxylic acids include cyclohexanedicarboxylic acid. Among these, it is preferable that the presence of an aromatic dicarboxylic acid be included, and more preferably that the presence of terephthalic acid be included. The amount of constituent units derived from aromatic dicarboxylic acid is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and 100 mol% or less, and preferably 100 mol%, of the constituent units derived from the carboxylic acid component of resin A.

[0022] The amount of terephthalic acid constituent units derived from PET is preferably 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and 100 mol% or less, preferably 90 mol% or less, and even more preferably 85 mol% or less, compared to the constituent units derived from aromatic dicarboxylic acid.

[0023] Examples of polycarboxylic acids with a valency of 3 or higher include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalentricarboxylic acid, and pyromellitic acid. Among these, trimellitic acid is preferred.

[0024] PET is produced by a polycondensation reaction between an alcohol component and a carboxylic acid component, and / or by the depolymerization of a portion of PET. The resulting ethylene glycol and terephthalic acid are used as raw material monomers in the polycondensation reaction and incorporated into the polyester resin. PET is an equimolar polycondensate of ethylene glycol and terephthalic acid, and the amounts of constituent units derived from the alcohol component and the carboxylic acid component mentioned above include ethylene glycol constituent units and terephthalic acid constituent units derived from PET, respectively. PET can be manufactured by conventional methods through polycondensation of ethylene glycol with terephthalic acid, dimethyl terephthalate, etc. The PET may be new virgin PET or recycled PET. Recycled PET is obtained by collecting used PET, washing and separating it from other materials as needed, pulverizing it, depolymerizing the pulverized material to monomer units, and then resynthesizing it using these as raw materials.

[0025] The intrinsic viscosity of PET (hereinafter also referred to as "IV value") is preferably 0.40 or higher, more preferably 0.50 or higher, even more preferably 0.55 or higher, and preferably 0.85 or lower, more preferably 0.80 or lower, even more preferably 0.75 or lower, and even more preferably 0.70 or lower, from the viewpoint of obtaining printed materials with high image density. The IV value of PET can be adjusted by the polycondensation time, etc. The IV value can be measured, for example, by dissolving the sample at a concentration of 0.4 g / dL in a phenol / tetrachloroethane = 60 / 40 (mass ratio) mixed solvent, measuring it with an Ubbelohde viscometer, and calculating it according to the following formula.

[0026]

number

[0027] Examples of commercially available PET products include "RAMAPET L1" (manufactured by Indorama Ventures, IV value: 0.60), "RAMAPET BF3067" (manufactured by Indorama Ventures, IV value: 0.65), "RAMAPET N2G" (manufactured by Indorama Ventures, IV value: 0.75), "TRN-NTJ" (manufactured by Teijin Limited, IV value: 0.53), "TRN-RTJC" (manufactured by Teijin Limited, IV value: 0.64), and "UK-31" (manufactured by Utsumi Recycling Systems Co., Ltd., IV value: 0.67).

[0028] In resin A, the molar equivalent ratio (COOH group / OH group) of the carboxyl group (COOH group / OH group) of the carboxylic acid component to the hydroxyl group (OH group) of the alcohol component is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower. Furthermore, the "molar equivalent ratio (COOH group / OH group)" shall be calculated assuming that the alcohol component contains the same amount of ethylene glycol as the ethylene glycol constituent units derived from PET, and the carboxylic acid component contains the same amount of terephthalic acid as the terephthalic acid constituent units derived from PET.

[0029] The PET content is preferably 3 mol% or more, more preferably 7 mol% or more, even more preferably 15 mol% or more, and preferably 85 mol% or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less, out of 100 mol% of the total amount of alcohol component, carboxylic acid component, and PET that are raw materials of resin A, from the viewpoint of obtaining printed materials with high image density. Since PET is a polycondensate of ethylene glycol, terephthalic acid, dimethyl terephthalate, etc., the terephthalic acid-ethylene glycol unit (Mw: 192) is considered as 1 mole. Therefore, moles of PET = moles of ethylene glycol = moles of terephthalic acid.

[0030] ≪Method for producing amorphous polyester resin A≫ Resin A can be produced by polycondensation of raw materials containing an alcohol component, a carboxylic acid component, and PET. The polycondensation of the alcohol component, carboxylic acid component, and PET can be carried out, for example, in an inert gas atmosphere, at a temperature of approximately 120°C to 250°C, in the presence of an esterification catalyst, esterification co-catalyst, polymerization inhibitor, etc., as needed. Examples of esterification catalysts include tin compounds such as dibutyltin oxide and di(2-ethylhexanoate)tin(II), and titanium compounds such as titanium diisopropoxybis(triethanolamine). Examples of esterification co-catalysts that can be used together with the esterification catalyst include gallic acid (3,4,5-trihydroxybenzoic acid). The amount of esterification catalyst used is preferably 0.01 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total amount of the alcohol component, carboxylic acid component, and PET that are the raw materials of resin A. The amount of esterification co-catalyst used is preferably 0.001 parts by mass or more and 1 part by mass or less, relative to 100 parts by mass of the total amount of the alcohol component, carboxylic acid component, and PET that are the raw materials of resin A. Examples of polymerization inhibitors include radical polymerization inhibitors such as 4-tert-butylcatechol. When a polymerization inhibitor is used, the amount of polymerization inhibitor used is preferably 0.001 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component, carboxylic acid component, and PET that are the raw materials of resin A.

[0031] ≪Physical properties of polyester resin A≫ The softening point of resin A is preferably 70°C or higher, more preferably 85°C or higher, even more preferably 95°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, and even more preferably 120°C or lower. The glass transition temperature of resin A is preferably 35°C or higher, more preferably 40°C or higher, even more preferably 45°C or higher, and preferably 75°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower.

[0032] The acid value of resin A is preferably 1 mg KOH / g or more, more preferably 3 mg KOH / g or more, even more preferably 5 mg KOH / g or more, and preferably 30 mg KOH / g or less, more preferably 25 mg KOH / g or less, and even more preferably 20 mg KOH / g or less.

[0033] The softening point, glass transition temperature, and acid value of resin A can be appropriately adjusted depending on the type and amount of raw material monomer used, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. These values ​​can be determined by the method described in the examples. Furthermore, when using two or more types of resin A in combination, it is preferable that at least one of them falls within the range of the above-mentioned physical properties. Moreover, it is even more preferable that the softening point, glass transition temperature, and acid value obtained as a mixture thereof are each within the aforementioned ranges.

[0034] (Crystalline polyester resin C) From the viewpoint of obtaining printed materials with high image density, the binder resin may contain crystalline polyester resin C (hereinafter also simply referred to as "resin C"), and it is preferable that it contains resin C.

[0035] Crystalline polyester resin C is a polycondensate of an alcohol component and a carboxylic acid component. As the alcohol component, α,ω-aliphatic diols are preferred. The number of carbon atoms in the α,ω-aliphatic diol is preferably 2 or more, preferably 16 or less, more preferably 12 or less, and even more preferably 8 or less. Examples of α,ω-aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol. Among these, 1,6-hexanediol is preferred.

[0036] The amount of α,ω-aliphatic diol 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 100 mol% or less, and preferably 100 mol%, in the alcohol component.

[0037] The alcohol component may contain other alcohol components other than α,ω-aliphatic diols. Examples of other alcohol components include aliphatic diols other than α,ω-aliphatic diols such as 1,2-propanediol and neopentyl glycol; alkylene oxide adducts of aromatic diols such as alkylene oxide adducts of bisphenol A; and trivalent or higher alcohols such as glycerin, pentaerythritol, and trimethylolpropane.

[0038] As the carboxylic acid component, aliphatic dicarboxylic acids are preferred, and linear aliphatic dicarboxylic acids are more preferred. The number of carbon atoms in the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 14 or less, more preferably 12 or less. Examples of aliphatic dicarboxylic acids include fumaric acid, sebacic acid, dodecanediic acid, and tetradecanediic acid. Among these, sebacic acid is preferred.

[0039] The amount of aliphatic dicarboxylic acid is preferably 70 mol% or more, more preferably 75 mol% or more, even more preferably 80 mol% or more, even more preferably 85 mol% or more, and 100 mol% or less, and preferably 95 mol% or less, in the carboxylic acid component.

[0040] From the viewpoint of obtaining printed materials with high image density, the carboxylic acid component preferably contains a monocarboxylic acid. From the same viewpoint, the number of carbon atoms in the monocarboxylic acid is preferably 6 or more, more preferably 8 or more, even more preferably 12 or more, even more preferably 16 or more, and preferably 24 or less, more preferably 22 or less, and even more preferably 20 or less. Examples of monocarboxylic acids include caprylic acid, pelargonic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, and lignoceric acid. Among these, caprylic acid, lauric acid, stearic acid, and behenic acid are preferred, more preferably stearic acid and behenic acid, and even more preferably stearic acid. When the carboxylic acid component includes a monocarboxylic acid, the amount of monocarboxylic acid is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and preferably 25 mol% or less, more preferably 20 mol% or less, and even more preferably 15 mol% or less, of the carboxylic acid component.

[0041] The carboxylic acid component may contain other carboxylic acid components other than aliphatic dicarboxylic acids and monocarboxylic acids. Examples of other carboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; and polycarboxylic acids with a valency of three or more, such as trimellitic acid.

[0042] The equivalent ratio [COOH group / OH group] of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0043] A method for manufacturing resin C may be, for example, the same method as for resin A.

[0044] ≪Physical properties of crystalline polyester resin C≫ The softening point of resin C is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. From the viewpoint of further improving low-temperature fixation, it is preferably 130°C or lower, more preferably 110°C or lower, and even more preferably 90°C or lower.

[0045] The melting point of resin C is preferably 50°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher. From the viewpoint of further improving low-temperature fixability, it is preferably 130°C or lower, more preferably 110°C or lower, and even more preferably 90°C or lower.

[0046] The acid value of resin C is preferably 3 mg KOH / g or more, more preferably 5 mg KOH / g or more, and more preferably 20 mg KOH / g or less, more preferably 15 mg KOH / g or less, and even more preferably 10 mg KOH / g or less.

[0047] The softening point, melting point, and acid value of resin C can be appropriately adjusted depending on the type and amount of raw material monomer used, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. The softening point, melting point, and acid value can be determined by the method described in the examples. When two or more types of resin C are used in combination, it is preferable that the softening point, melting point, and acid value obtained from the mixture thereof are within the aforementioned ranges.

[0048] From the viewpoint of obtaining printed materials with high image density, the content of the binder resin in the toner particles is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, and preferably 99% by mass or less, more preferably 97% by mass or less.

[0049] From the viewpoint of obtaining printed materials with high image density, the content of resin A in the binder resin is preferably 65% ​​by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and 100% by mass or less, and preferably 95% by mass or less.

[0050] When the binder resin contains resin C, the content of resin C in the binder resin is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, and preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, from the viewpoint of low-temperature fixation.

[0051] When the binder resin contains resin C, the mass ratio of resin C to resin A in the toner particles [resin C / resin A] is preferably 1 / 99 or more, more preferably 5 / 95 or more, even more preferably 7 / 93 or more, even more preferably 12 / 88 or more, and preferably 45 / 55 or less, more preferably 40 / 60 or less, even more preferably 35 / 65 or less, and even more preferably 30 / 70 or less.

[0052] <Coloring agent> In the present invention, the toner particles contain a colorant, and the colorant contains CI Pigment Red 254, which is a pigment. The toner particles may contain colorants other than CI Pigment Red 254, as long as the effects of the present invention are not impaired.

[0053] The colorant content in the toner particles is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0054] From the viewpoint of obtaining a printed coating with good image quality, the content of pigment red 254 in the coloring agent is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and 100% by mass or less, and preferably 100% by mass.

[0055] The colorant content is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, from the viewpoint of improving dispersibility in toner particles, per 100 parts by mass of binder resin.

[0056] <Release agent> Toner particles preferably contain a release agent. Examples of release agents include hydrocarbon waxes or oxides thereof such as polypropylene wax, polyethylene wax, ethylene propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; ester waxes such as carnauba wax, montane wax or their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts.

[0057] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and more preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 100°C or lower. The release agent content is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and preferably 25% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, in the toner particles.

[0058] In addition, the toner particles may contain additives such as charge control agents, magnetic powders, flowability enhancers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, anti-aging agents, and cleaning performance enhancers.

[0059] <Physical properties of toner particles> Volume-intermediate particle size D of toner particles 50 From the viewpoint of obtaining a print coating with good image quality and further improving the cleanability of the toner, the thickness is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less.

[0060] From the viewpoint of obtaining a print coating (image) with good image quality, the circularity of the toner particles is preferably 0.945 or higher, more preferably 0.950 or higher, even more preferably 0.955 or higher, and even more preferably 0.960 or higher. From the viewpoint of cleanability, it is preferably 0.990 or lower, more preferably 0.985 or lower, and even more preferably 0.980 or lower. Volume-intermediate particle size D of toner particles 50 The roundness can be measured by the method described in the examples.

[0061] The CV value of the toner particles is preferably 10% or more, more preferably 12% or more, and even more preferably 14% or more, from the viewpoint of improving toner productivity, and preferably 50% or less, more preferably 45% or less, and even more preferably 40% or less, from the viewpoint of obtaining good image quality.

[0062] [Method for manufacturing toner for electrostatic image development] The method for producing electrostatic image developing toner of the present invention (hereinafter also simply referred to as "toner production method") may be any known method such as the melt-kneading method, the emulsion-phase inversion method, the suspension polymerization method, or the emulsion-coagulation method, but the emulsion-coagulation method and the melt-kneading method are preferred, and the emulsion-coagulation method is more preferred.

[0063] <Emulsification aggregation method> The emulsification and coagulation method includes the steps of coagulating and fusing resin particles containing the same or different resin particles with a coloring agent containing CI Pigment Red 254 in an aqueous medium. Examples of "resin particles containing resins in the same particle" include resin particles containing resin A and resin C. Examples of "resin particles containing resins in different particles" include resin particles containing resin A and resin particles containing resin C.

[0064] (Process for agglomerating resin particles) In the process of agglomerating resin particles, resin particles containing the same or different resin particles are agglomerated with CI pigment red 254 in an aqueous medium to obtain agglomerated particles 1. It is preferable to mix a resin particle dispersion containing resin particles with a coloring agent particle dispersion containing CI pigment red 254, and to agglomerate these particles to obtain agglomerated particles 1. It is preferable to further agglomerate a release agent in addition to the resin particles and coloring agent. Furthermore, in the process of agglomerating resin particles, the agglomerated particles 1 may contain additives such as charge control agents, magnetic powders, flowability enhancers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, anti-aging agents, and cleaning properties enhancers. In the present invention, the aqueous medium is a medium whose main component is water, and the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and 100% by mass or less. Deionized water or distilled water is preferred as the water. Other components that can constitute an aqueous medium together with water include alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and organic solvents that dissolve in water, such as cyclic ethers such as tetrahydrofuran.

[0065] ≪Method for producing resin particle dispersion≫ The resin particles are preferably manufactured as an aqueous dispersion using an aqueous medium. Dispersion can be carried out using known methods, but dispersion by phase inversion emulsification is preferred. Examples of phase inversion emulsification methods include adding an aqueous medium to an organic solvent solution of the resin or to a molten resin and then emulsifying it. Adding an aqueous medium to an organic solvent solution of the resin and then emulsifying it is preferred. The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin and is water-soluble, but for example, methyl ethyl ketone can be used for resins A and C. A neutralizing agent may be added to the organic solvent solution. Examples of neutralizing agents include basic substances. Examples of basic substances include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred. The degree of neutralization of the resin constituting the resin particles is preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 55 mol% or more, and preferably 100 mol% or less, more preferably 95 mol% or less, and even more preferably 90 mol% or less. The degree of neutralization of the resin constituting the resin particles can be determined by the following formula. Degree of neutralization (mol%) = [{Amount of neutralizing agent added (g) / Equivalent amount of neutralizing agent} / [{Weighted average acid value of the resin constituting the resin particles (mgKOH / g) × Mass of the resin constituting the resin particles (g)} / (56 × 1000)]] × 100

[0066] While stirring the organic solvent solution of the resin, or the molten resin, an aqueous medium is gradually added to induce phase inversion. When adding an aqueous medium, the temperature of the organic solvent solution is preferably above the glass transition temperature of the resin constituting the resin particles, more preferably above 70°C, and more preferably below 100°C, more preferably below 95°C, and even more preferably below 90°C, from the viewpoint of improving the dispersion stability of the resin particles.

[0067] After phase inversion emulsification, the organic solvent may be removed from the resulting dispersion by distillation or other means, if necessary. Alternatively, the resin particles may be isolated by filtration or other means. It is preferable to use an aqueous dispersion of resin particles from which the organic solvent has been removed after phase inversion emulsification. In this case, the amount of residual 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.

[0068] Volume-intermediate particle size D of resin particles 50 The particle size is preferably 0.08 μm or more, more preferably 0.15 μm or more, and preferably 1 μm or less, more preferably 0.6 μm or less, and even more preferably 0.4 μm or less. The CV value of the resin particles is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less. Volume-intermediate particle size D of resin particles 50The CV value is measured by the method described in the examples.

[0069] The solid content concentration of the resin particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, from the viewpoint of improving toner productivity and improving the dispersion stability of the aqueous dispersion of resin particles. Note that the solid content represents the total amount of non-volatile components.

[0070] ≪Method for producing a dispersion of coloring agent particles≫ The colorant particle dispersion is preferably obtained by dispersing the pigment CI Pigment Red 254 and an aqueous medium using a disperser such as a homomixer, homogenizer, or ultrasonic disperser. From the viewpoint of improving the dispersion stability of the pigment, this dispersion is preferably carried out in the presence of a polymer-type pigment dispersant (preferably addition polymer E) or a surfactant.

[0071] For addition polymer E that improves the dispersion stability of the pigment, for example, the addition polymer described in Japanese Patent Publication No. 2024-25642 can be referenced.

[0072] Examples of surfactants that improve the dispersion stability of pigments include nonionic surfactants, anionic surfactants, and cationic surfactants, with nonionic surfactants being preferred from the viewpoint of improving the dispersion stability of pigments. Examples of nonionic surfactants include polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, and polyoxyalkylene aryl ethers. Among these, polyoxyethylene aryl ethers are preferred, and polyoxyethylene distyleninated phenyl ethers are more preferred.

[0073] In the colorant particle dispersion, the mass ratio of colorant to surfactant (colorant / surfactant) is preferably 50 / 50 or more, more preferably 55 / 45 or more, even more preferably 60 / 40 or more, even more preferably 65 / 35 or more, and preferably 95 / 5 or less, more preferably 90 / 10 or less, and even more preferably 85 / 15 or less, from the viewpoint of the image density of the printed material.

[0074] The solid content concentration of the coloring agent particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0075] Volume-intermediate particle size D of colorant particles 50 From the viewpoint of improving dispersibility in toner particles, the particle size is preferably 0.05 μm or larger, more preferably 0.08 μm or larger, even more preferably 0.1 μm or larger, and preferably 0.4 μm or smaller, more preferably 0.3 μm or smaller, and even more preferably 0.2 μm or smaller. From the viewpoint of improving dispersibility in toner particles, the CV value of the colorant particles is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. Volume-intermediate particle size D of colorant particles 50 The CV value is measured by the method of the example.

[0076] ≪Method for manufacturing a release agent particle dispersion≫ A mold release agent particle dispersion can be obtained, for example, by dispersing a dispersion of mold release agent and resin particles, along with an aqueous medium as needed, at a temperature above the melting point of the mold release agent using a dispersion machine such as a homogenizer, high-pressure disperser, or ultrasonic disperser. The heating temperature during dispersion is preferably above the melting point of the release agent and 80°C or higher, more preferably 85°C or higher, even more preferably 90°C or higher, and preferably 100°C or lower, more preferably 98°C or lower, and even more preferably 96°C or lower.

[0077] While a release agent particle dispersion can be obtained using a surfactant, it is preferable to obtain it by mixing the release agent and resin particles. By preparing release agent particles using the release agent and resin particles, the release agent particles are stabilized by the resin constituting the resin particles, making it possible to disperse the release agent in an aqueous medium without using a surfactant. In the release agent particle dispersion, it is thought that the release agent particles have a structure in which many resin particles are attached to the surface. The resin constituting the resin particles that disperse the mold release agent is preferably a polyester resin, and more preferably a composite resin having a polyester resin segment and an addition polymerization resin segment. For details on the mold release agent particle dispersion and the composite resin, refer to Japanese Patent Application Publication No. 2024-25642. Alternatively, the aforementioned resin A may be used. The dispersion of resin particles that disperse the mold release agent is obtained by the method for producing the resin particle dispersion described above.

[0078] Release agent particle volume median particle size D 50 From the viewpoint of obtaining uniform aggregated particles 1 by aggregation, the particle size is preferably 0.05 μm or larger, more preferably 0.2 μm or larger, even more preferably 0.3 μm or larger, and preferably 1 μm or smaller, more preferably 0.8 μm or smaller, and even more preferably 0.6 μm or smaller. The CV value of the release agent particles is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less. Release agent particle volume median particle size D 50 The CV value is measured by the method described in the examples.

[0079] - Surfactants - In the process of agglomerating resin particles, when mixing the dispersions of each particle to prepare a mixed dispersion, the process may be carried out in the presence of a surfactant from the viewpoint of improving the dispersion stability of resin particles, release agent particles, colorant particles, etc. Examples of surfactants include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. When a surfactant is used, the total amount used is preferably 0.03 parts by mass or more, more preferably 0.06 parts by mass or more, even more preferably 0.1 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of resin particles.

[0080] -Agglutinant- In the process of agglomerating resin particles, it is preferable to add a flocculant from the viewpoint of efficiently carrying out the agglomeration. Examples of flocculants include cationic surfactants such as quaternary salts, organic flocculants such as polyethyleneimine, and inorganic flocculants. Examples of inorganic flocculants 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 metal complexes with a valency of 2 or higher. From the viewpoint of improving cohesiveness and obtaining uniform aggregated particles 1, inorganic metal salts with a valency of 1 to 5 are preferred, inorganic metal salts with a valency of 1 to 2 are more preferred, inorganic ammonium salts are even more preferred, and ammonium sulfate is even more preferred.

[0081] Using a flocculant, for example, 25 to 50 parts by mass of a flocculant per 100 parts by mass of resin particles is added to a mixed dispersion containing resin particles, release agent particles, and colorant particles at a temperature of 0°C to 40°C, and the resin particles, release agent particles, and colorant particles are flocculated in an aqueous medium to obtain flocculated particles 1. Furthermore, from the viewpoint of promoting flocculation, it is preferable to raise the temperature of the dispersion after adding the flocculant.

[0082] As methods for stopping aggregation, there are methods such as cooling the dispersion liquid, adding an aggregation stopping agent, diluting the dispersion liquid, and the like. From the viewpoint of reliably preventing unnecessary aggregation, the method of adding an aggregation stopping agent to stop aggregation is preferred. When there is a step of aggregating the shell resin particles for the purpose of manufacturing toner having a core-shell structure, the step of aggregating the shell resin particles may be performed when the aggregated particles 1 have grown to an appropriate particle size without stopping the aggregation.

[0083] The volume median diameter D of the aggregated particles 1 50 is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less. The volume median diameter D of the aggregated particles 1 50 is measured by the method described in the examples.

[0084] In the present invention, after the step of aggregating the resin particles and before the step of fusing, there may be a step of obtaining aggregated particles 2 by attaching and aggregating shell resin particles containing an amorphous resin to the obtained aggregated particles 1. By having a step of aggregating the shell resin particles, toner particles having a core-shell structure can be obtained. The shell resin particles are preferably an amorphous resin, more preferably an amorphous polyester resin. The shell resin particle dispersion liquid is obtained by the method for producing the resin particle dispersion liquid described above. The mass ratio of the shell resin particles to the mass of the aggregated particles 1 [shell resin particles / aggregated particles 1] is preferably 1 / 99 or more, more preferably 3 / 97 or more, still more preferably 5 / 95 or more, and is preferably 25 / 75 or less, more preferably 20 / 80 or less, still more preferably 15 / 85 or less, from the viewpoint of the low-temperature fixing property of the toner. When the toner manufacturing method has a step of aggregating the shell resin particles, it is preferable to stop the aggregation when the aggregated particles 2 have grown to an appropriate particle size as toner particles in this step, and the method of adding an aggregation stopping agent to stop the aggregation is preferred.

[0085] -Agglutination inhibitor- As a flocculation inhibitor, surfactants are preferred, and anionic surfactants are more preferred. Examples of anionic surfactants include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, polyoxyalkylene alkyl ether sulfates, aryl sulfonates, and aryl sulfonic acid formalin condensates. From the viewpoint of reliably preventing unnecessary aggregation, the amount of aggregation inhibitor added is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, per 100 parts by mass of aggregated particles immediately before adding the aggregation inhibitor, and from the viewpoint of reducing residue in the toner, it is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less.

[0086] (Fusing process) In the fusion process, for example, aggregated particles are fused together in an aqueous medium. Fusion bonding fuses the individual particles contained within the aggregated particles, resulting in fused particles. In the fusion process, from the viewpoint of improving the fusion properties of the aggregated particles and improving the low-temperature fixation properties of the toner, the aggregated particles are held at a temperature above the glass transition temperature of the amorphous polyester resin with the highest glass transition temperature among those contained in the aggregated particles. The holding (heating) temperature when fusing aggregated particles is preferably, from the viewpoint of improving toner productivity, at or above the glass transition temperature of the resin having the highest glass transition temperature among amorphous polyester resins, more preferably at or above 2°C higher, and even more preferably at or above 5°C higher, and preferably at or below 40°C higher, more preferably at or below 30°C higher, and even more preferably at or below 25°C higher than the glass transition temperature of the resin having the highest glass transition temperature among amorphous polyester resins. In this case, it is preferable to maintain the temperature mentioned above until the desired degree of circularity is achieved.

[0087] Volume median particle size D of fused particles obtained by fusion 50The particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less.

[0088] The circularity of the fused particles obtained by fusion is preferably 0.955 or higher, more preferably 0.960 or higher, and more preferably 0.990 or lower, more preferably 0.985 or lower, and even more preferably 0.980 or lower. It is preferable to terminate the fusion process after achieving the desired degree of circularity described above. The roundness is measured by the method described in the examples.

[0089] (Post-processing steps) A post-processing step may be performed after the fusion step, and toner particles can be obtained by isolating the fused particles. Since the fused particles obtained in the fusion step are present in an aqueous medium, it is preferable to first perform solid-liquid separation. Suction filtration or the like is preferably used for solid-liquid separation. It is preferable to perform washing after solid-liquid separation. At this time, it is also preferable to remove the added surfactant, so it is preferable to wash with an aqueous medium at a temperature below the cloud point of the surfactant. It is preferable to perform washing multiple times. Next, drying is preferable. Examples of drying methods include vacuum constant temperature drying, vibratory fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0090] <Melting and mixing method> In the present invention, the melt-kneading method involves uniformly mixing additives such as a binder resin, a colorant, and optionally a mold release agent in a mixer such as a Henschel mixer, and then melt-kneading in a closed-type kneader, a single-screw or twin-screw extruder, an open-roll type kneader, etc. Subsequently, toner particles can be obtained by cooling, grinding, and classifying the mixture.

[0091] [External additives] As described above, it is preferable to use toner particles treated with an external additive as the toner of the present invention. Examples of external additives include fine particles of inorganic materials such as hydrophobic silica, titanium dioxide, alumina, cerium oxide, and carbon black, as well as polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. One external additive may be used alone, or two or more may be used. In addition, two or more hydrophobic silicas with different particle sizes may be used. When surface treatment of toner particles is performed using an external additive, the amount of external additive added is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and even more preferably 4 parts by mass or less, per 100 parts by mass of toner particles.

[0092] Toner is used in electrophotographic printing for electrostatic image development. Toner can be used, for example, as a one-component developer, or mixed with a carrier to form a two-component developer. [Examples]

[0093] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. Each property value was measured and evaluated by the following method. In notations such as "alkylene oxide (X)," the number X in parentheses represents the average number of moles of alkylene oxide added.

[0094] [Measurement method] [Acid value of resins] The acid value of the resin was measured according to the neutralization titration method described in JIS K 0070:1992. However, chloroform was used as the measurement solvent.

[0095] [Softening point, crystallinity index, melting point, and glass transition temperature of resins] (1) Softening point Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample was heated at a heating rate of 6°C / min while a load of 1.96 MPa was applied by a plunger, and the sample was extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of plunger descent of the flow tester was plotted against temperature, and the temperature at which half of the sample flowed out was defined as the softening point. (2) Crystallinity index Using a differential scanning calorimeter "Q100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan and cooled to 0°C at a cooling rate of 10°C / min. The temperature was then maintained for 1 minute, and then the temperature was increased to 180°C at a heating rate of 10°C / min, and the amount of heat was measured. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was defined as the maximum endothermic peak temperature (1), and the crystallinity index was determined by (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)). (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. The sample was then heated again at a rate of 10°C / min, and the amount of heat was measured. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was defined as the maximum endothermic peak temperature (2). For crystalline resins, this peak temperature was defined as the melting point. For amorphous resins, if a peak was observed, the temperature of that peak was defined as the glass transition temperature. If no peak was observed but a step was observed, the temperature at the intersection of the tangent line showing the maximum slope of the curve in the step portion and the extension of the baseline on the low-temperature side of the step was defined as the glass transition temperature.

[0096] [Melting point of release agent] Using a differential scanning calorimeter "Q100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. The sample was then heated again at a rate of 10°C / min, the amount of heat was measured, and the maximum peak temperature of endothermic heating was defined as the melting point.

[0097] [Volume-intermediate particle size D of resin particles, release agent particles, and colorant particles] 50 [and CV value] (1) Measuring device: Laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.) (2) Measurement conditions: Place the sample dispersion in the measurement cell, add distilled water, and adjust the concentration to the appropriate range for absorbance, using a volume-average particle size D. 50 and volume-average particle size D V The following measurements were taken. Furthermore, the CV value (particle size distribution) was calculated according to the following formula. CV value (%) = (Standard deviation of particle size distribution / Volume average particle size D) V ) × 100

[0098] [Solid content concentration of resin particle dispersion, colorant particle dispersion, and mold release agent particle dispersion] Using an infrared moisture meter "FD-230" (manufactured by Kett Scientific Research Institute Co., Ltd.), the moisture content (mass%) of a 5g sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 min / fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0099] [Volume-intermediate particle size D of aggregated particles] 50 ] • Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 50 μm • Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte solution to adjust the concentration to one that could measure the particle size of 30,000 particles in 20 seconds. Then, the 30,000 particles were measured, and the volume median particle size D was determined from the particle size distribution. 50 They sought it.

[0100] [Circularity of fused particles and toner particles] • Measurement device: Flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) • Preparation of dispersion: A dispersion of fused particles or toner particles was prepared by diluting it with deionized water to a solid content concentration of 0.001 to 0.05% by mass. • Measurement mode: Circularity was determined using HPF measurement mode.

[0101] [Toner particle volume medium particle size D] 50 ] The measuring instrument, aperture diameter, analysis software, and electrolyte are related to the volume-median particle size D of the aggregated particles mentioned above. 50 The same equipment used in the measurement was employed. • Dispersion: Polyoxyethylene lauryl ether "Emulgen® 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance): 13.6) was dissolved in the electrolyte to obtain a dispersion with a concentration of 5% by mass. • Dispersion conditions: 10 mg of the toner particle measurement sample was added to 5 mL of the dispersion, dispersed for 1 minute using an ultrasonic disperser, then 25 mL of the electrolyte was added, and dispersed for another minute using an ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration to a level that allows for the measurement of 30,000 particle sizes in 20 seconds. Then, 30,000 particles are measured, and the volume median particle size D is determined from the particle size distribution. 50 They sought it.

[0102] [Manufacturing of binding resins] [Manufacturing of amorphous polyester resin] Manufacturing Example A1 (Manufacturing of Amorphous Polyester Resin A-1) The alcohol component, carboxylic acid component, PET, esterification catalyst, and esterification co-catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, dehydration tube with condenser, and thermocouple. Under a nitrogen atmosphere, the temperature was raised to 235°C, and polycondensation was carried out at 235°C for 6 hours. After that, the temperature was lowered to 210°C, and the reaction was carried out under reduced pressure of 10 kPa until the softening point shown in Table 1 was reached to obtain amorphous polyester resin A-1. The physical properties are shown in Table 1.

[0103] Manufacturing Examples A2-A7 (Manufacturing of amorphous polyester resins A-2-A-7) The alcohol component, carboxylic acid component, PET, esterification catalyst, and esterification co-catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer, a dehydration tube fitted with a fractionation tube through which 98°C hot water was passed, and a thermocouple. Under a nitrogen atmosphere, the mixture was held at 180°C for 1 hour, then the temperature was increased from 180°C to 235°C at a rate of 10°C / h, and polycondensation was carried out at 235°C for 5 hours. After that, the temperature was reduced to 210°C and the reaction was carried out under reduced pressure of 10 kPa until the softening point shown in Table 1 was reached to obtain amorphous polyester resins A-2 to A-7. The physical properties are shown in Table 1.

[0104] Manufacturing Example A51 (Manufacturing of Amorphous Polyester Resin A-51) The alcohol component, carboxylic acid component, esterification catalyst, and esterification co-catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, dehydration tube with condenser, and thermocouple. Under a nitrogen atmosphere, the temperature was raised to 235°C, and polycondensation was carried out at 235°C for 6 hours. After that, the temperature was lowered to 210°C, and the reaction was carried out under reduced pressure of 10 kPa until the softening point shown in Table 1 was reached to obtain amorphous polyester resin A-51. The physical properties are shown in Table 1.

[0105] Manufacturing Example A52 (Manufacturing of Amorphous Polyester Resin A-52) The alcohol component, carboxylic acid component, esterification catalyst, and esterification co-catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube fitted with a fractionation tube through which 98°C hot water was passed, a stirrer, and a thermocouple. Under a nitrogen atmosphere, the mixture was held at 180°C for 1 hour, then the temperature was increased from 180°C to 235°C at a rate of 10°C / h, and polycondensation was carried out at 235°C for 5 hours. After that, the temperature was reduced to 210°C and the reaction was carried out under reduced pressure of 10 kPa until the softening point shown in Table 1 was reached to obtain amorphous polyester resin A-52. The physical properties are shown in Table 1.

[0106] [Table 1]

[0107] [Manufacturing of crystalline resins] Manufacturing Example C1 (Manufacturing of Crystalline Polyester Resin C-1) The alcohol and carboxylic acid components shown in Table 2 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube with a fall-flow condenser, and a nitrogen inlet tube. The mixture was heated to 200°C over 8 hours in a mantle heater under a nitrogen atmosphere. Subsequently, the esterification catalyst shown in Table 2 was added, and the reaction was carried out at 8 kPa until the softening point shown in Table 2 was reached, yielding crystalline polyester resin C-1. The physical properties are shown in Table 2.

[0108] [Table 2]

[0109] Manufacturing example D1 (Manufacturing of resin D-1) A 10L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 3450g of bisphenol A propylene oxide (2,2) adduct, 655g of terephthalic acid, 24g of tin(II) di(2-ethylhexanoate), and 2.4g of gallic acid (3,4,5-trihydroxybenzoic acid) were added. Under a nitrogen atmosphere, the reaction system was stirred and the temperature was raised to 235°C, where it was maintained for 5 hours. After that, the pressure inside the flask was reduced and maintained at 8kPa for 1 hour. After returning to atmospheric pressure, it was cooled to 160°C, and while maintained at 160°C, a mixture of 2133g of styrene, 533g of stearyl methacrylate, 114g of acrylic acid, and 320g of dibutyl peroxide was added dropwise over 3 hours. The reaction system was then maintained at 160°C for 30 minutes, then the temperature was raised to 200°C, and the pressure in the flask was further reduced to 8 kPa and maintained for 1 hour. After returning to atmospheric pressure, it was cooled to 190°C, 582 g of succinic acid was added, and the temperature was raised to 210°C at a rate of 10°C / hr. The reaction was then carried out at 4 kPa until the desired softening point was reached to obtain resin D-1. The softening point of resin D-1 was 91°C, the crystallinity index was 1.8, the glass transition temperature was 42°C, and the acid value was 24 mg KOH / g.

[0110] [Manufacturing of resin particle dispersions] Manufacturing Example X1 (Manufacturing of Resin Particle Dispersion X-1) In a 3-liter container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, 160 g of resin A-1, 40 g of resin C-1, and 200 g of methyl ethyl ketone were placed, and the resins were dissolved at 73°C for 2 hours. To the resulting solution, a 5% by mass aqueous sodium hydroxide solution was added to achieve a degree of neutralization of 60 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 200 r / min (peripheral speed 63 m / min) to induce phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was removed under reduced pressure to obtain a resin dispersion. Afterward, the dispersion was cooled to 30°C while continuing to stir, and then deionized water was added to achieve a solid content concentration of 20% by mass to obtain resin particle dispersion X-1. The obtained resin particle medium particle size D 50 The corresponding CV values ​​are shown in Table 3.

[0111] Production examples X2~X7, X51, X52 (manufacture of resin particle dispersions X-2~X-7, X-51, X-52) Except for changing the type of resin used as shown in Table 3, resin particle dispersions X-2 to X-7, X-51, and X-52 were obtained in the same manner as in production example X1. The median volume particle size D of the obtained resin particles 50 The corresponding CV values ​​are shown in Table 3.

[0112] [Table 3]

[0113] Manufacturing Example Y1 (Manufacturing of resin particle dispersion Y-1) In a 3L container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, 200g of resin D-1 and 200g of methyl ethyl ketone were placed, and the resin was dissolved at 73°C for 2 hours. To the resulting solution, a 5% by mass aqueous sodium hydroxide solution was added to achieve a degree of neutralization of 60 mol% relative to the acid value of resin D-1, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 280 r / min (peripheral speed 88 m / min) to induce phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was removed under reduced pressure to obtain an aqueous dispersion of the resin. Subsequently, the aqueous dispersion was cooled to 30°C while stirring at 280 r / min (peripheral speed 88 m / min), and then deionized water was added to obtain resin particle dispersion Y-1 by bringing the solid content concentration to 20% by mass. The median volume particle size of the obtained resin particles was 0.09 μm, and the CV value was 23%.

[0114] [Manufacturing of mold release agent particle dispersion] Manufacturing Example W1 (Manufacturing of Release Agent Particle Dispersion W-1) In a 1L beaker, 120g of deionized water, 86g of resin particle dispersion Y-1, and 40g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) were added. The mixture was melted while maintaining a temperature of 90-95°C and stirred to obtain a molten mixture. The obtained molten mixture was further dispersed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while maintaining the temperature at 90-95°C, and then cooled to room temperature (20°C). Deionized water was added to the obtained dispersion to adjust the solid content concentration to 20% by mass, and release agent particle dispersion W-1 was obtained. The volume-median particle size D of the release agent particles 50 The particle size was 0.47 μm, and the CV value was 27%.

[0115] [Manufacturing of colorant particle dispersion] Manufacturing Example E1 (Manufacturing of Colorant Particle Dispersion E-1) 150g of CI Pigment Red 254 (PV Fast Red D3G, manufactured by Heubach Color Japan Co., Ltd.), 50g of nonionic surfactant (polyoxyethylene distyrenated phenyl ether) "Emulgen A-60", and 750g of deionized water were added to a 2L container. The mixture was stirred at 6400 r / min at 20°C for 1 hour using a stirrer equipped with a disperser blade, "Labo-Solution" (manufactured by Primix Co., Ltd.). Afterwards, the mixture was passed through a 200-mesh filter and subjected to 15 passes at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). Subsequently, the mixture was passed through a 200-mesh filter again, and deionized water was added to obtain a colorant particle dispersion E-1 by reducing the solid content concentration to 20% by mass. The median particle size D of the obtained colorant particles was... 50 The corresponding CV values ​​are shown in Table 4.

[0116] Manufacturing Example E51 (Manufacturing of Colorant Particle Dispersion E-51) Colorant particle dispersion E-51 was obtained in the same manner as in production example E1, except that the pigment used was changed to CI Pigment Red 150 (FUJI FAST CARMINE 520, manufactured by Fuji Pigment Co., Ltd.). The volume-median particle size D of the obtained colorant particles 50 The corresponding CV values ​​are shown in Table 4.

[0117] [Table 4]

[0118] Example 1 (Manufacturing of Toner 1) In a 3L four-necked flask equipped with a reflux condenser, stirrer, and thermocouple, 500g of resin particle dispersion X-1, 40g of mold release agent particle dispersion W-1, 47g of coloring agent particle dispersion E-1, and 1.1g of 15% by mass sodium dodecylbenzenesulfonate aqueous solution "Neoperex G-15" (manufactured by Kao Corporation, anionic surfactant) were added and mixed at a temperature of 25°C. Next, while stirring the resulting mixture, a solution prepared by dissolving 40g of ammonium sulfate in 570g of deionized water and adding a 4.8% by mass potassium hydroxide aqueous solution to adjust the pH to 8.4 was added dropwise over 10 minutes at 25°C, and the temperature was raised to 61°C over 2 hours to determine the volume-median particle size D of the aggregated particles. 50 The mixture was maintained at 61°C until it reached a size of 6.3 μm, and a dispersion of aggregated particles 1 was obtained. To the dispersion of the obtained aggregated particles 1, an aqueous solution was added, which consisted of 10 g of polyoxyethylene lauryl ether sodium sulfate "Emal E-27C" (manufactured by Kao Corporation, anionic surfactant, effective concentration 27% by mass), 280 g of deionized water, and 35 g of 0.1 mol / L sulfuric acid aqueous solution. The mixture was then heated to 72°C over 1 hour, held at 72°C for 30 minutes, and then 15 g of 0.1 mol / L sulfuric acid aqueous solution was added, followed by a further 15 minutes of holding at 72°C. After that, another 10 g of 0.1 mol / L sulfuric acid aqueous solution was added, and the mixture was held at 72°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles in which the aggregated particles 1 had fused together. The resulting dispersion of fused particles was cooled to 30°C, and the dispersion was filtered by suction to separate the solid components. The mixture was then washed with deionized water at 25°C and filtered by suction at 25°C for 2 hours. Subsequently, vacuum drying was performed at 33°C for 24 hours using a vacuum constant-temperature dryer "DRV622DA" (manufactured by ADVANTEC) to obtain toner particles 1. The median volume particle size D of the obtained toner particles 1... 50 The diameter was 6.0 μm, and the circularity was 0.970. To 100 parts by mass of toner particles 1, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.04 μm) and 1 part by mass of hydrophobic silica "Cabosil® TS720" (manufactured by Cabot Corporation, average particle size: 0.012 μm) were mixed in a Henschel mixer and stirred, and the mixture was passed through a 150-mesh sieve to obtain toner 1. The obtained toner 1 was evaluated as follows. The evaluation results of toner 1 are shown in Table 5.

[0119] [Image density of printed materials] Using high-quality paper "J Paper A4 size" (manufactured by Fujifilm Business Innovation Co., Ltd.) and a commercially available printer "Microline® 5400" (manufactured by Oki Electric Industry Co., Ltd.), the amount of toner adhering to the paper was 0.30 mg / cm². 2 The resulting solid image was output without being fixed. Next, a modified version of the printer with a variable-temperature fuser was prepared. The fuser temperature was set to 115°C, and toner was fixed at a rate of 2.0 seconds per sheet in A4 portrait orientation to obtain a printed document. Thirty sheets of high-quality paper, "Excellent White Paper A4 size" (manufactured by OKI Electric Industry Co., Ltd.), were placed under the printed material. The reflective image density of the solid image areas of the printed material was measured using a colorimeter, "SpectroEye" (manufactured by Gretag Macbeth, lighting conditions: standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard). The average of the values ​​measured at 10 arbitrary points on the image was used as the image density. A higher numerical value indicates better image density.

[0120] Examples 2-7, Comparative Examples 1-3 (Manufacturing of toners 2-7 and 81-83) Toners 2-7 and 81-83 were manufactured in the same manner as in Example 1, except that the types of resin particle dispersion and colorant particle dispersion used were changed as shown in Table 5. The evaluation results for toners 2-7 and 81-83 are shown in Table 5.

[0121] [Table 5]

[0122] Example 8 (Manufacturing of Toner 8) 80 parts by mass of resin A-1, 20 parts by mass of resin C-1, 7 parts by mass of CI pigment red 254 (PV Fast Red D3G, manufactured by Heubach Color Japan Co., Ltd.), and 4 parts by mass of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) as a release agent were mixed in a Henschel mixer. The resulting mixture was melt-kneaded using a co-rotating twin-screw extruder with a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm, at a screw rotation speed of 200 r / min and a barrel setting temperature of 100°C to obtain a molten compound. The mixture was fed at a rate of 20 kg / hour, and the average residence time was approximately 18 seconds. The obtained molten compound was cooled and coarsely ground, then ground in a jet mill, and classified using an air-flow classifier (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain a medium volume particle size D 50 This yielded powder (toner particles 8) with a particle size of 6.0 μm and a circularity of 0.948. To 100 parts by mass of toner particles 8, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.04 μm) and 1 part by mass of hydrophobic silica "Cabosil® TS720" (manufactured by Cabot Corporation, average particle size: 0.012 μm) were mixed in a Henschel mixer and stirred, and the mixture was passed through a 150-mesh sieve to obtain toner 8. The evaluation results of toner 8 are shown in Table 6.

[0123] Example 9 (Manufacturing of Toner 9) Toner 9 was manufactured in the same manner as in Example 8, except that the resin used was changed as shown in Table 6. The evaluation results of toner 9 are shown in Table 6.

[0124] [Table 6]

[0125] Tables 5 and 6 show that printed materials obtained using the toner of the present invention, which contains amorphous polyester resin A, a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and CI pigment red 254, exhibit excellent image density (Examples 1-9). In contrast, printed materials obtained using a toner containing amorphous polyester resin manufactured without polyethylene terephthalate had low image density (Comparative Examples 1 and 2). Furthermore, printed materials obtained using a toner containing CI pigment red 150 also had low image density (Comparative Example 3).

Claims

1. A toner for developing electrostatic images containing a binder resin and a colorant, The aforementioned binder resin contains amorphous polyester resin A, which comprises a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate. The aforementioned coloring agent contains C.I. Pigment Red 254. Toner for developing electrostatic images.

2. The electrostatic image developing toner according to claim 1, wherein the constituent units derived from the alcohol component of amorphous polyester resin A include constituent units derived from aliphatic diols, and the content of the aliphatic diol-derived constituent units is 40 mol% or more of the constituent units derived from the alcohol component.

3. The electrostatic image developing toner according to claim 1 or 2, wherein the polyethylene terephthalate content is 3 mol% or more and 85 mol% or less of the total amount of alcohol component, carboxylic acid component and polyethylene terephthalate, with terephthalate-ethylene glycol units considered as 1 mole.

4. The electrostatic image developing toner according to claim 1 or 2, wherein the binder resin further contains a crystalline polyester resin C.

5. A method for producing an electrostatic image developing toner according to claim 1 or 2, comprising the steps of agglomerating resin particles and colorant particles, and fusing the agglomerated particles obtained in the step, The aforementioned resin particles contain amorphous polyester resin A, which contains a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate. A method for manufacturing toner for electrostatic image developing, wherein the colorant contained in the colorant particles contains C.I. Pigment Red 254.

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