Toner for developing electrostatic images

Abstract

This invention relates to a toner for electrostatic image development that exhibits excellent weather resistance and image density, and to a method for manufacturing the same. [Solution] A toner for developing electrostatic images containing an amorphous polyester resin A and a colorant, wherein the amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and the colorant contains a quinacridone-based pigment, and a method for manufacturing the same.

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, and a method for manufacturing the same. [Background technology]

[0002] In recent years, toner-based printing has become increasingly common in industrial and commercial printing. Because printed materials are often used outdoors, weather resistance is a key requirement. Furthermore, the frequent use of high-resolution images such as photographs necessitates improved image density.

[0003] On the other hand, the use of polyethylene terephthalate as a raw material for the binder resin of toner is being considered (see Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-88255 [Overview of the project] [Problems that the invention aims to solve]

[0005] Among the magenta pigments used in toners for electrostatic image development, quinacridone pigments are known for their high weather resistance. Quinacridone pigments have high weather resistance due to strong intermolecular hydrogen bonds and layered molecular structure. However, these same intermolecular hydrogen bonds result in poor dispersibility in polyester resins, leading to low coloring power and the inability to obtain printed materials with high image density.

[0006] The present invention relates to a toner for electrostatic image development with excellent weather resistance and image density, and a method for manufacturing the same. [Means for solving the problem]

[0007] The present invention relates to 〔1〕 An electrostatic charge image developing toner containing a binder resin containing an amorphous polyester resin A and a colorant, wherein the amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and the colorant contains a quinacridone-based pigment, and 〔2〕 A method for producing the electrostatic charge image developing toner according to 〔1〕 above, including a step of melt-kneading at least a binder resin and a colorant, and a step of pulverizing the kneaded product obtained in this step relates to.

Effect of the Invention

[0008] The electrostatic charge image developing toner of the present invention exhibits excellent effects in terms of weather resistance and image density.

Embodiments for Carrying out the Invention

[0009] The electrostatic charge image developing toner of the present invention contains a binder resin and a colorant, and has a major feature in that the binder resin is an amorphous polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate (PET), and the colorant contains a quinacridone-based pigment. The reason for the effects of the present invention is not clear, but it is presumed as follows. The following mechanism is a presumption and is not limited thereto.

[0010] Quinacridone-based pigments are easy to stack due to the planar structure of the basic skeleton of quinacridone, and also show interactions due to intermolecular hydrogen bonds between NH groups and CO groups. Therefore, while they have excellent weather resistance, they have difficulty in dispersibility in polyester-based resins, and the coloring power inherent in the pigments cannot be fully utilized in the toner. By adding physical shear to improve the dispersibility of quinacridone-based pigments in polyester-based resins, the image density of printed matter is improved, but for some reason, the interaction between quinacridone-based pigment molecules is weakened, resulting in a decrease in weather resistance. In contrast, in the present invention, it has been found that by using a polycondensate of an alcohol component, a carboxylic acid component, and PET (amorphous polyester resin A), it is possible to achieve both high image density and excellent weather resistance of a printed matter. This is because in the polycondensation reaction of the alcohol component, the carboxylic acid component, and PET to obtain the amorphous polyester resin A, although PET undergoes depolymerization and is incorporated into the polyester resin chain by transesterification, it is not completely randomized and exists as a unit of a certain length called a PET segment in the resin. Due to the interaction between this PET segment and quinacridone-based pigment molecules, the dispersibility of the quinacridone-based pigment in the polyester resin is improved, and thus a printed matter with excellent image density can be obtained. At this time, although the interaction between quinacridone-based pigment molecules is weakened, it is presumed that a printed matter with excellent weather resistance can be obtained because the quinacridone-based pigment molecules are stabilized by the interaction between the amorphous polyester resin A and the quinacridone-based pigment.

[0011] Whether a resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum peak temperature of endotherm (softening point (°C) / maximum peak temperature of endotherm (°C)) in the measurement method described in the examples below. A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one 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 of the resin can be adjusted by the type and ratio of the raw material monomers, and manufacturing conditions (for example, reaction temperature, reaction time, cooling rate), etc. The maximum peak temperature of endotherm refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. In a crystalline resin, the maximum peak temperature of endotherm is taken as the melting point.

[0012] The amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component, and PET.

[0013] From the viewpoint of low-temperature fixing property, the alcohol component has the formula (I):

[0014] [ka]

[0015] (In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a 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 greater, preferably 1.5 or greater, and 16 or less, preferably 8 or less, more preferably 6 or less, and even more preferably 4 or less.) It is preferable to include an alkylene oxide adduct of bisphenol A represented by formula (I). Examples of alkylene oxide adducts of bisphenol A represented by formula (I) include ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A. It is preferable to use one or more of these.

[0016] The content of the bisphenol A alkylene oxide adduct represented by formula (I) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component. However, the ethylene glycol units of PET are not included in the alcohol component as referred to herein.

[0017] Other alcohol components include aliphatic diols and trivalent or higher alcohols.

[0018] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol, 1,3-butanediol, and neopentyl glycol.

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

[0020] From the viewpoint of resistance to hot offsetting, the carboxylic acid component preferably includes an aromatic dicarboxylic acid compound.

[0021] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0022] The content of aromatic dicarboxylic acid compounds is preferably 20 mol% or more, more preferably 35 mol% or more, even more preferably 45 mol% or more, even more preferably 55 mol% or more, and 100 mol% or less, of the carboxylic acid component. If the carboxylic acid component includes trivalent or higher carboxylic acid compounds, the content is preferably 90 mol% or less, more preferably 85 mol% or less. However, the terephthalic acid units contained in PET are not included in the carboxylic acid component as referred to herein.

[0023] Other carboxylic acid components include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, aliphatic dicarboxylic acids such as glutaric acid, adipic acid, and sebacic acid, trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0024] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0025] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol and carboxylic acid components.

[0026] In PET, ethylene glycol and terephthalic acid, produced by the polycondensation reaction of an alcohol component and a carboxylic acid component, and / or by the depolymerization of a portion of PET, are subjected to a polycondensation reaction as raw material monomers and incorporated into the polyester resin.

[0027] The PET can be either new virgin PET or recycled PET. Recycled PET refers to material obtained by collecting used PET, washing it as needed, separating it from other materials, crushing it, depolymerizing the crushed material to monomer units, and then resynthesizing it using these monomers as raw materials.

[0028] In this invention, it is preferable that the PET has a relatively low IV value, i.e., a low molecular weight, compared to conventionally used PET. By introducing low IV value (low molecular weight) PET into the polyester resin, the depolymerization of PET proceeds more uniformly.

[0029] From the viewpoint of the above, the IV value of PET is preferably 0.40 or higher, more preferably 0.45 or higher, even more preferably 0.50 or higher, and still more preferably 0.55 or higher. From the viewpoint of low-temperature fixability and homogenization of depolymerization, it is preferably 0.85 or lower, more preferably 0.80 or lower, even more preferably 0.75 or lower, even more preferably 0.70 or lower, and still more preferably 0.65 or lower. The IV value is the intrinsic viscosity and serves as an indicator of molecular weight. The IV value of PET can be adjusted by the polycondensation time, etc.

[0030] Commercially available PET products with an IV value between 0.40 and 0.85 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), RAMAPET S1 (manufactured by Indorama Ventures, IV value: 0.84), and UK-31 (manufactured by Utsumi Recycle Systems Co., Ltd., IV value: 0.67).

[0031] The content of low-IV PET 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, of the total amount of PET subjected to polycondensation.

[0032] The PET content is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 50 mol% or less, from the viewpoint of image density and weather resistance, relative to the total amount of alcohol component, carboxylic acid component, and PET. Since PET is an equimolar polycondensate of ethylene glycol, terephthalic acid, dimethyl terephthalate, etc., the terephthalic acid-ethylene glycol unit (Mw: 192) is considered as 1 mole. Therefore, the number of moles of PET = the number of moles of ethylene glycol units = the number of moles of terephthalic acid units. If amorphous polyester resin A consists of two or more resins, the weighted average value of the PET content of each resin shall be used as the PET content of amorphous polyester resin A.

[0033] The equivalent ratio (COOH group / OH group) of the carboxylic acid component (including terephthalic acid units in PET) to the alcohol component (including ethylene glycol units in PET) is preferably 0.6 or higher, more preferably 0.7 or higher, even more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0034] Amorphous polyester resin A is preferably a polycondensate obtained by reacting an alcohol component, a carboxylic acid component, and PET in the presence of an esterification catalyst. For example, it can be produced by polycondensing an alcohol component, a carboxylic acid component, and PET in an inert gas atmosphere, in the presence of an esterification catalyst, and optionally in the presence of a co-catalyst, polymerization inhibitor, etc., at a temperature preferably 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0035] Examples of esterification catalysts include tin-based catalysts and titanium-based catalysts, with titanium-based catalysts being preferred from the viewpoint of image density and weather resistance.

[0036] Examples of tin-based catalysts include dibutyltin oxide and tin(II) 2-ethylhexanoate.

[0037] As titanium-based catalysts, reaction products of titanium compounds and alkanolamines are preferred. Specific examples of reaction products of titanium compounds and alkanolamines include titanium tetrakis(monoethanol amine), titanium monohydroxytris(triethanol amine), titanium dihydroxybis(triethanol amine), titanium trihydroxytriethanol amine, titanium dihydroxybis(diethanol amine), titanium dihydroxybis(monoethanol amine), titanium dihydroxybis(monopropanol amine), titanium dihydroxybis(N-methyldiethanol amine), titanium dihydroxybis(N-butyldiethanol amine), and titanium monoisopropoxytris(tri Examples include ethanol ammonium compounds, titanium diisopropoxybis(triethanol ammonium compounds), titanium triisopropoxytriethanol ammonium compounds, reaction products of tetrahydroxytitanium and N,N,N',N'-tetrahydroxyethylethylenediamine, titanylbis(triethanol ammonium compounds), titanylbis(diethanol ammonium compounds), titanylbis(monoethanol ammonium compounds), titanyl hydroxyethanol ammonium compounds, titanyl hydroxytriethanol ammonium compounds, titanyl ethoxytriethanol ammonium compounds, titanyl isopropoxytriethanol ammonium compounds, and intramolecular or intermolecular polycondensates thereof.

[0038] The amount of esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, based on 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET.

[0039] Furthermore, gallic acid and the like can be used as co-catalysts for the esterification catalyst. The amount of co-catalyst used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of the alcohol component, carboxylic acid component and PET. Tert-butylcatechol and the like can be used as polymerization inhibitors. The amount of polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of the alcohol component, carboxylic acid component and PET.

[0040] In this invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins that have been grafted or blocked with phenol, urethane, epoxy, etc., by methods described in Japanese Patent Publication No. 11-133668, Japanese Patent Publication No. 10-239903, Japanese Patent Publication No. 8-20636, etc. Among modified polyester resins, urethane-modified polyester resins obtained by urethane elongation of polyester resin with a polyisocyanate compound are preferred.

[0041] The softening point of amorphous polyester resin A is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower, from the viewpoint of resistance to hot offset.

[0042] The glass transition temperature of amorphous polyester resin A is preferably 40°C or higher, more preferably 50°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of resistance to hot offset.

[0043] The acid value of amorphous polyester resin A is preferably 1 mg KOH / g or more, more preferably 3 mg KOH / g or more, and preferably 25 mg KOH / g or less, more preferably 20 mg KOH / g or less, from the viewpoint of low-temperature fixability and storage properties.

[0044] The content of amorphous polyester resin A in the binder resin is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less.

[0045] Other binder resins include amorphous polyester resins, crystalline polyester resins, vinyl resins such as styrene-acrylic resins, polyamide resins, epoxy resins, polycarbonate resins, polyurethane resins, and composite resins containing two or more of these resins, which are polycondensates of alcohols and carboxylic acid components that do not use PET.

[0046] Furthermore, the binder resin preferably contains two types of resins with different softening points, from the viewpoint of low-temperature fixability and fixation width. The difference in softening points between the two types of resins is preferably 10°C or more, more preferably 20°C or more, and preferably 60°C or less, more preferably 40°C or less.

[0047] The softening point of the resin with the higher softening point (resin AH) is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower, from the viewpoint of resistance to hot offset.

[0048] Furthermore, the softening point of the resin with the lower softening point (resin AL) is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 130°C or lower, more preferably 125°C or lower, and even more preferably 120°C or lower, from the viewpoint of resistance to hot offset.

[0049] Either resin AH or resin AL may be amorphous polyester resin A, or both may be amorphous polyester resin A. If either one is amorphous polyester resin A, the other resin is preferably amorphous polyester resin B, which is a polycondensate of alcohol and a carboxylic acid component that does not use PET. When the binder resin consists of amorphous polyester resin A and amorphous polyester resin B, it is preferable that the weighted average value of the PET content of each resin is within the range of the aforementioned PET content.

[0050] The mass ratio of resin AH to resin AL (resin AH / resin AL) is preferably 10 / 90 or more, more preferably 20 / 80 or more, even more preferably 30 / 70 or more, and preferably 90 / 10 or less, more preferably 80 / 20 or less, and even more preferably 70 / 30 or less.

[0051] The binder resin content in the toner is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and preferably 99% by mass or less, more preferably 97% by mass or less, and even more preferably 95% by mass or less.

[0052] Examples of quinacridone pigments include dimethylquinacridone pigment, unsubstituted quinacridone pigment, and dichloroquinacridone pigment. However, from the viewpoint of image density and weather resistance, quinacridone pigments that do not contain chloro groups are preferred, and dimethylquinacridone pigment is more preferred.

[0053] Examples of dimethylquinacridone pigments include CI Pigment Red 122.

[0054] Examples of unsubstituted quinacridone pigments include CI Pigment Violet 19, CI Pigment Red 206, CI Pigment Orange 48, and 49.

[0055] Examples of dichloroquinacridone pigments include CI Pigment Red 209 and 202.

[0056] The quinacridone pigment content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, per 100 parts by mass of the binder resin, and from the viewpoint of low-temperature fixation, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 12 parts by mass or less.

[0057] The toner of the present invention may contain colorants other than the quinacridone pigment, as long as the effects of the present invention are not impaired. However, the content of the quinacridone pigment is preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and 100% by mass or less, in the colorant. Other colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, carmine 6B, disazo yellow, naphthol pigment, and the like.

[0058] In addition to the binder resin (binder) and colorant, the toner of the present invention may contain additives such as a mold release agent, charge control agent, magnetic powder, flowability improver, conductivity modifier, reinforcing filler such as fibrous material, antioxidant, and cleaning performance improver.

[0059] Examples of mold release agents include hydrocarbon waxes and their oxides, 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 and their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which can be used individually or in combination of two or more.

[0060] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixation.

[0061] The release agent content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 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 7 parts by mass or less, per 100 parts by mass of binder resin, from the viewpoint of low-temperature fixation and offset resistance of the toner and dispersibility in the binder resin.

[0062] The charge control agent is not particularly limited and may contain either a positively charged charge control agent or a negatively charged charge control agent.

[0063] Positively charged charge control agents include nigrosine dyes, such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," "Bontron N-11," and "Bontron N-79" (all manufactured by Orient Chemical Industries, Ltd.); triphenylmethane-based dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX." Examples include VP435 (manufactured by Clariant), polyamine resins such as AFP-B (manufactured by Orient Chemical Industries, Ltd.), imidazole derivatives such as PLZ-2001 and PLZ-8001 (both manufactured by Shikoku Chemicals, Ltd.), and styrene-acrylic resins such as FCA-701PT and FCA-201-PS (manufactured by Fujikura Chemicals, Ltd.).

[0064] Furthermore, as negative charge control agents, polymer types such as "FCA-2521NJ" (manufactured by Fujikura Chemical Co., Ltd.), etc.; metal-containing azo dyes such as "Barifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", "Bontron S-36" (all manufactured by Orient Chemical Industry Co., Ltd.), "Eisenspiron Black TRH", "T-77" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; metal compounds of benzyl acid compounds such as "LR-147", "LR-297" (both manufactured by Nippon Carlit Co., Ltd.), etc.; metal compounds of salicylic acid compounds such as "Bontron E-81", "Bontron E-84", "Bontron E-88", "Bontron E-304" (all manufactured by Orient Chemical Industry Co., Ltd.), "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; copper phthalocyanine dyes; quaternary ammonium salts such as "COPY CHARGE Examples include "NX VP434" (manufactured by Clariant), nitroimidazole derivatives, organometallic compounds, etc.

[0065] From the viewpoint of the charge stability of the toner, the content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, per 100 parts by mass of the binder resin.

[0066] The toner of the present invention may be obtained by any of the conventionally known methods, such as melt-kneading, emulsification-coagulation, or suspension polymerization, and may also be a toner having a core-shell structure. However, from the viewpoint of the miscibility of the toner raw materials, it is preferable to manufacture it by a method that includes at least a step of melt-kneading a binder resin and a colorant (melt-kneading step), and a step of grinding the kneaded product obtained in the step (grinding step).

[0067] In the melt-mixing process, it is preferable to pre-mix the raw materials containing the binder resin and colorant to be melt-mixed using a Henschel mixer or the like before melt-mixing.

[0068] Melt mixing can be carried out using known kneaders such as closed-type kneaders, single-screw or twin-screw extruders, or open-roll type kneaders. From the viewpoint of reducing the temperature during melt mixing and improving the durability and low-temperature fixability of the toner, and from the viewpoint of efficiently dispersing additives such as colorants, charge control agents, and release agents in the toner without repeated mixing or the use of dispersion aids, it is preferable to use an open-roll type kneader, and it is preferable that the open-roll type kneader is provided with a feed port and a kneaded material discharge port along the axial direction of the rolls.

[0069] An open-roll type kneader is one in which the kneading section is not sealed but open, allowing for easy dissipation of the heat generated during melt-mixing. The open-roll type kneader used in this invention is equipped with a raw material supply port and a kneaded material discharge port located along the axial direction of the rolls, and from the viewpoint of production efficiency, a continuous open-roll type kneader is preferable.

[0070] The open-roll type kneader used in the present invention is preferably a kneader equipped with two rolls with different peripheral speeds, namely a roll with a high peripheral speed (high-speed roll) and a roll with a low peripheral speed (low-speed roll). In the present invention, from the viewpoint of dispersibility of the kneaded material, it is preferable that the high-speed roll functions as a heating roll and the low-speed roll functions as a cooling roll, namely that the set temperature of the high-speed roll is higher than the set temperature of the low-speed roll. If the set temperatures of the rolls differ on the raw material input side and the kneaded material discharge side, it is preferable that the set temperature of the high-speed roll is higher than the set temperature of the low-speed roll at least on the raw material input side, and it is more preferable that the set temperature of the high-speed roll is higher than the set temperature of the low-speed roll on both the raw material input side and the kneaded material discharge side.

[0071] The temperature of the roll can be adjusted, for example, by the temperature of the heat transfer medium passed through the roll. Each roll may also have its interior divided into two or more sections through which heat transfer mediums with different temperatures are passed.

[0072] From the viewpoint of reducing mechanical force during melting and kneading and suppressing heat generation, the temperature on the raw material input side of the high-speed roll is preferably 100°C or higher, more preferably 120°C or higher, and preferably 160°C or lower, more preferably 150°C or lower. From a similar viewpoint, the temperature on the raw material input side of the low-speed roll is preferably 25°C or higher, more preferably 40°C or higher, and preferably 90°C or lower, more preferably 80°C or lower.

[0073] In both high-speed and low-speed rolls, it is preferable that the temperature on the raw material input side is higher than the temperature on the mixed material discharge side. The temperature difference between the raw material input side and the mixed material discharge side is preferably 10°C or higher, more preferably 30°C or higher, and preferably 80°C or lower, more preferably 50°C or lower, from the viewpoint of preventing the mixed material from detaching from the rolls and reducing mechanical force during melt kneading to suppress heat generation.

[0074] The temperature on the raw material input side of the high-speed and low-speed rolls refers to the set temperature at the raw material input end, while the temperature on the kneaded material discharge side refers to the set temperature at the kneaded material discharge end.

[0075] The peripheral speed of the high-speed roll is preferably 2 m / min or more, more preferably 10 m / min or more, even more preferably 25 m / min or more, and preferably 100 m / min or less, more preferably 75 m / min or less, and even more preferably 50 m / min or less, from the viewpoint of reducing mechanical force during mixing and suppressing heat generation. The peripheral speed of the low-speed roll is preferably 1 m / min or more, more preferably 5 m / min or more, even more preferably 15 m / min or more, and preferably 90 m / min or less, more preferably 60 m / min or less, and even more preferably 30 m / min or less, from the same viewpoint. Furthermore, the ratio of the peripheral speeds of the two rolls (low-speed roll / high-speed roll) is preferably 1 / 10 or more, more preferably 3 / 10 or more, and preferably 9.9 / 10 or less, and even more preferably 8 / 10 or less.

[0076] Furthermore, there are no particular limitations on the structure, size, or material of each roll. The surface of the roll has grooves used for mixing, and these grooves can be straight, spiral, wavy, or uneven.

[0077] After the melt-mixing process, the resulting mixture is cooled to a suitable hardness for pulverization and then subjected to the subsequent pulverization process. Here, cooling refers to cooling the mixture to 0°C to 50°C, or to a temperature below the glass transition temperature of the binder resin in the mixture.

[0078] The crushing process is the process of crushing the mixture obtained in the melt-kneading process.

[0079] In the grinding process, the kneaded material may be ground all at once to the desired particle size, or it may be ground in stages. However, from the viewpoint of efficient and more uniform grinding, it is preferable to perform the grinding in two stages: coarse grinding and fine grinding.

[0080] Examples of grinders used for coarse grinding include hammer mills, cutter mills, atomizers, and Rotoplexes.

[0081] Examples of grinders used for fine grinding include counter-jet mills, fluidized bed jet mills, impact plate jet mills, and other types of jet mills, as well as mechanical mills.

[0082] The degree of fine grinding is preferably adjusted as appropriate according to the desired toner particle size.

[0083] After the crushing process, a classification process is performed as needed.

[0084] Classifiers used for classification include air-flow classifiers, inertia classifiers, and sieve classifiers. During the classification process, any pulverized material that is removed due to insufficient pulverization may be subjected to the pulverization process again, and the pulverization and classification processes may be repeated as needed.

[0085] In the toner of the present invention, it is preferable to use an external additive to improve fluidity. Examples of external additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more may be used in combination. Among these, silica is preferred, and from the viewpoint of toner fluidity, hydrophobic silica that has been hydrophobicized is more preferred.

[0086] Examples of hydrophobic agents used to hydrophobize the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0087] The average particle size of the external additive is preferably 10 nm or larger, more preferably 250 nm or smaller, more preferably 200 nm or smaller, and even more preferably 90 nm or smaller, from the viewpoint of the toner's chargeability, fluidity, and transferability.

[0088] External additive treatment, which involves mixing toner particles with external additives, can be carried out according to conventional methods, and a mixer such as a Henschel mixer can be used.

[0089] From the viewpoint of the toner's electrostatic properties, fluidity, and transferability, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, and more preferably 4 parts by mass or less, per 100 parts by mass of toner particles before treatment with the external additive.

[0090] The volume-intermediate particle size (D) of the toner of the present invention 50 The volume median particle size (D) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. 50) refers to the particle size at which the cumulative volume frequency calculated using volume fractions accounts for 50% when calculated from the smallest particle size. Furthermore, if the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0091] The toner of the present invention can be used as is as a one-component developing toner, or as a two-component developing toner used in combination with a carrier, in image forming apparatuses using either a one-component developing method or a two-component developing method, respectively. [Examples]

[0092] 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. The physical properties of resins, etc., can be measured by the following methods.

[0093] [PET IV value] The phenol / tetrachloroethane is dissolved at a concentration of 4 g / L in a 60 / 40 (mass ratio) mixed solvent, and the concentration is measured using an Ubbelohde viscometer and calculated using the following formula. IV = (-1 + √(1 + 4kη)) / (2kC) [In the formula, k = 0.33, C = 0.004 g / mL, and η = (t1 / t0) - 1 (t0: number of seconds for the solvent to fall, t1: number of seconds for the sample solution to fall).]

[0094] [Softening point of resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample is heated at a heating rate of 6°C / min while a load of 1.96 MPa is applied by a plunger, and the sample is 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 is plotted against temperature, and the temperature at which half of the sample has flowed out is defined as the softening point.

[0095] [Maximum peak temperature of endothermic resin] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and cooled from room temperature (25°C) to 0°C at a rate of 10°C / min, and maintained at 0°C for 1 minute. Then, measurements are taken at a rate of 10°C / min. Among the observed endothermic peaks, the temperature of the peak with the largest peak area is defined as the maximum endothermic peak temperature.

[0096] [Glass transition temperature of resins] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan, heated to 200°C, and then cooled to 0°C at a rate of 10°C / min. Next, the sample is heated again at a rate of 10°C / min, and the endothermic peak is measured. The temperature at the intersection of the baseline extension below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rise of the peak to the peak apex is defined as the glass transition temperature.

[0097] [Acid value of resins] The measurement will be performed according to the method of JIS K 0070:1992. However, the measurement solvent will be changed from the ethanol and ether mixture specified in JIS K 0070 to an acetone and toluene mixture (acetone:toluene = 1:1 (volume ratio)).

[0098] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample is 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. Next, the sample is heated again at a rate of 10°C / min, the amount of heat is measured, and the maximum peak temperature of endothermic heating is defined as the melting point.

[0099] [Volume median particle size and CV value of resin particles, colorant particles, and mold release agent particles] (1) Measuring device: Laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.) (2) Measurement conditions: Take the sample dispersion into a measuring cell, add distilled water, and measure the volume mid-particle size (D) at a temperature where the absorbance is within the appropriate range. 50 The volume-average particle size is measured. The CV value is calculated according to the following formula. CV value (%) = (Standard deviation of particle size distribution / Volume-average particle size) × 100

[0100] [Solid content concentration of resin dispersion, colorant dispersion, and mold release agent dispersion] Using the infrared moisture meter "FD-230" (manufactured by Kett Scientific Research Institute Co., Ltd.), 5g of the sample to be measured was dried at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, variation range 0.05%), and the moisture content (mass%) of the dispersion was measured. The solid content concentration was calculated according to the following formula. Solid content concentration (mass%) = 100-moisture (mass%)

[0101] [Medium particle size by volume of aggregated particles] • 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 )

[0102] [Toner volume medium particle size (D 50 )〕 • Measuring instrument: "Coulter Multisizer (Registered Trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 50 μm • Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Dispersion: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust the concentration to 5% by mass. • Dispersion conditions: Add 10 mg of the sample to 5 mL of the dispersion and disperse for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Corporation, output: 80W). Then, add 25 mL of electrolyte and disperse for another minute using the ultrasonic disperser to prepare the 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, the 30,000 particles are measured, and the volume median particle size (D) is determined from the particle size distribution. 50 )

[0103] [Toner circularity] The circularity of the toner particles will be measured under the following conditions. • Measurement device: Flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) • Preparation of dispersion: Prepare the dispersion of toner particles by diluting it with deionized water so that the solid content concentration is 0.001 to 0.05% by mass. • Measurement mode: HPF measurement mode

[0104] [Average particle size of external additives] The average particle diameter refers to the number-average particle diameter, which is calculated by measuring the particle size (average of the major and minor axes) of 500 particles (primary particles) from scanning electron microscope (SEM) images and using the number-average value of these measurements.

[0105] Resin manufacturing example 1 The alcohol components, carboxylic acid components other than trimellitic anhydride, PET, esterification catalyst, and co-catalyst shown in Tables 1 and 2 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, and thermocouple. The mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 6 hours. After that, the temperature was lowered to 210°C, trimellitic anhydride shown in Tables 1 and 2 was added, and the mixture was reacted at 210°C for 1 hour. The reaction was then carried out at 210°C under reduced pressure of 10 kPa until the softening point shown in Tables 1 and 2 was reached, yielding amorphous polyester resins (resins AH1-AH5, AH8, AH10-AH13). The physical properties are shown in Tables 1 and 2.

[0106] Resin manufacturing example 2 The alcohol component, carboxylic acid component, PET, esterification catalyst, and co-catalyst shown in Tables 1 and 3 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, and 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 lowered to 210°C and the reaction was carried out under reduced pressure of 10 kPa until the softening point shown in Tables 1 and 3 was reached to obtain amorphous polyester resins (resins AH6, AH7, resins AL6, AL7). The physical properties are shown in Tables 1 and 3.

[0107] Resin manufacturing example 3 The alcohol components, carboxylic acid components other than trimellitic anhydride and fumaric acid shown in Table 2, PET, esterification catalyst, and co-catalyst were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, and thermocouple. The mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 6 hours. After that, the temperature was lowered to 180°C, and trimellitic anhydride, fumaric acid, and polymerization inhibitor shown in Table 2 were added. The mixture was reacted at 180°C for 1 hour, then the temperature was raised from 180°C to 210°C at 10°C / h, and polycondensation was further carried out at 210°C for 1 hour. After that, the reaction was carried out at 210°C under reduced pressure of 10 kPa until the softening point shown in Table 2 was reached to obtain amorphous polyester resin (resin AH9). The physical properties are shown in Table 2.

[0108] Resin manufacturing example 4 The alcohol components, carboxylic acid components other than trimellitic anhydride, esterification catalyst, and co-catalyst shown in Table 2 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, and thermocouple. The mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 6 hours. After that, the temperature was lowered to 210°C, trimellitic anhydride as shown in Table 2 was added, and the mixture was reacted at 210°C for 1 hour. The reaction was then continued at 210°C under reduced pressure of 10 kPa until the softening point shown in Table 2 was reached, yielding an amorphous polyester resin (resin AH14). The physical properties are shown in Table 2.

[0109] Resin manufacturing example 5 The alcohol component, carboxylic acid component other than trimellitic anhydride, esterification catalyst, and co-catalyst shown in Table 2 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, trimellitic anhydride as shown in Table 2 was added, and the reaction was carried out at 210°C for 1 hour. Then, the reaction was carried out at 210°C under reduced pressure of 10 kPa until the softening point shown in Table 2 was reached, yielding an amorphous polyester resin (resin AH15). The physical properties are shown in Table 2.

[0110] Resin manufacturing example 6 The alcohol component, carboxylic acid component, PET, esterification catalyst, and co-catalyst shown in Tables 3 and 4 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, 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 Tables 3 and 4 was reached to obtain amorphous polyester resins (resins AL1-AL5, AL8, AL10-AL13). The physical properties are shown in Tables 3 and 4.

[0111] Resin manufacturing example 7 The alcohol component, carboxylic acid component other than fumaric acid, PET, esterification catalyst, and co-catalyst shown in Table 4 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, and thermocouple. Under a nitrogen atmosphere, the temperature was raised to 235°C, and polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 180°C, and the fumaric acid and polymerization inhibitor shown in Table 4 were added. The reaction was carried out at 180°C for 1 hour, and then the temperature was raised from 180°C to 210°C at a rate of 10°C / h, and polycondensation was carried out at 210°C for another 1 hour. After that, the reaction was carried out at 210°C under reduced pressure of 10 kPa until the softening point shown in Table 4 was reached to obtain amorphous polyester resin (resin AL9). The physical properties are shown in Table 4.

[0112] Resin manufacturing example 8 The alcohol component, carboxylic acid component, esterification catalyst, and co-catalyst shown in Table 4 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, stirrer, 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 4 was reached to obtain amorphous polyester resin (resin AL14). The physical properties are shown in Table 4.

[0113] Resin manufacturing example 9 The alcohol component, carboxylic acid component, esterification catalyst, and co-catalyst shown in Table 4 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. The mixture was held at 180°C for 1 hour under a nitrogen atmosphere, then the temperature was increased from 180°C to 235°C at a rate of 10°C / h, and then polycondensation was carried out at 235°C for 5 hours. Furthermore, the reaction was carried out at 235°C under reduced pressure of 10 kPa until the softening point shown in Table 4 was reached to obtain an amorphous polyester resin (resin AL15). The physical properties are shown in Table 4.

[0114] [Table 1]

[0115] [Table 2]

[0116] [Table 3]

[0117] [Table 4]

[0118] Examples 1, 6-17, 21, Comparative Example 2 [Melting and Kneading Method] 100 parts by mass of the binder resin shown in Table 5, 7 parts by mass of the coloring agent "FASTOGEN SUPER MAGENTA R3-E" (manufactured by DIC Corporation, quinacridone-based pigment, CI Pigment Red 122 (PR122)), 5 parts by mass of the release agent "FNP0090" (manufactured by Nippon Seiro Co., Ltd., Fischer-Tropsch wax, melting point: 90°C), and 0.5 parts by mass of the charge control agent "Bontron E-304" (manufactured by Orient Chemical Industries, Ltd.) were mixed in a Henschel mixer.

[0119] The obtained mixture was melt-mixed using a continuous double-roll open-roll mixer "Nidex" (manufactured by Nippon Coke Industries Co., Ltd.). The continuous double-roll open-roll mixer had a roll outer diameter of 0.14 m and an effective roll length of 0.8 m. The operating conditions were a rotation speed of 75 r / min (peripheral speed 33 m / min) for the high-speed roll (front roll), a rotation speed of 50 r / min (peripheral speed 22 m / min) for the low-speed roll (rear roll), and a roll gap of 0.1 mm. The heating and cooling media temperatures inside the rolls were set to 140°C on the raw material input side and 110°C on the mixed material discharge side of the high-speed roll, and to 65°C on the raw material input side and 30°C on the mixed material discharge side of the low-speed roll. The raw material mixture supply rate was 10 kg / h, and the average residence time was approximately 5 minutes.

[0120] The resulting mixture is 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 the medium volume particle size (D 50 ) yielded toner particles with a size of 7.0 μm.

[0121] 100 parts by mass of the obtained toner particles and 1 part by mass of "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic silica, hydrophobic treatment agent: DMDS, average particle size: 16 nm) and 2 parts by mass of "RY-50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic silica, hydrophobic treatment agent: silicone oil, average particle size: 40 nm) as external additives were mixed in a Henschel mixer at a rotation speed of 3000 r / min (peripheral speed 32 m / sec) for 3 minutes to obtain magenta toner.

[0122] Example 2, Comparative Example 1 Magenta toner was obtained in the same manner as in Example 1, except that the operating conditions of the continuous two-roll open-type kneader were set to a rotation speed of 75 r / min (peripheral speed 33 m / min) for the high-speed roll (front roll), a rotation speed of 30 r / min (peripheral speed 13 m / min) for the low-speed roll (rear roll), a roll gap of 0.1 mm, and the temperatures of the heating and cooling media inside the rolls were set to 100°C on the raw material input side and 30°C on the kneaded material discharge side of the high-speed roll, and to 45°C on the raw material input side and 30°C on the kneaded material discharge side of the low-speed roll, and the raw material mixture supply rate was set to 2 kg / h.

[0123] Example 3 A magenta toner was obtained in the same manner as in Example 1, except that 7 parts by mass of "Ink Jet Magenta E5B02" (manufactured by Clariant, quinacridone-based pigment, CI Pigment Violet 19 (PV19)) was used as a coloring agent instead of "FASTOGEN SUPER MAGENTA R3-E".

[0124] Example 4 A magenta toner was obtained in the same manner as in Example 1, except that 7 parts by mass of "FASTOGEN SUPER RED 209 228-6736" (manufactured by DIC Corporation, quinacridone-based pigment, CI Pigment Red 209 (PR209)) was used as a coloring agent instead of "FASTOGEN SUPER MAGENTA R3-E".

[0125] Example 5 A magenta toner was obtained in the same manner as in Example 1, except that 7 parts by mass of "FASTOGEN SUPER MAGENTA HS-01 (manufactured by DIC Corporation, quinacridone-based pigment, CI Pigment Red 202 (PR202))" were used as a coloring agent instead of "FASTOGEN SUPER MAGENTA R3-E".

[0126] Example 18 A magenta toner was obtained in the same manner as in Example 1, except that the amount of "FASTOGEN SUPER MAGENTA R3-E" used as a coloring agent was changed to 4.9 parts by mass, and 2.1 parts by mass of "Permanent Carmine 3810" (manufactured by Sanyo Shikkei Co., Ltd., naphthol-based pigment, CI Pigment Red 269 (PR269)) was also used.

[0127] Example 19 Magenta toner was obtained in the same manner as in Example 1, except that a co-rotating twin-screw extruder was used instead of a continuous twin-roll open-roll type kneader during melt-mixing. The co-rotating twin-screw extruder had a total length of 1560 mm for the kneading section, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The operating conditions were a screw rotation speed of 200 r / min, a barrel set temperature of 100°C, a mixture supply rate of 20 kg / h, and an average residence time of approximately 18 seconds.

[0128] Example 20 [Emulsification and Coagulation Method] <Preparation of resin dispersion for core> 600 g of methyl ethyl ketone was charged into a 5-liter container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, and 150 g of resin AH1 was added and dissolved at 60°C. To the resulting solution, an aqueous 5 mass% sodium hydroxide solution was added to a neutralization degree of 60 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes to obtain a mixture. Subsequently, 675 g of deionized water was added over 77 minutes. Then, while stirring at 250 r / min, methyl ethyl ketone and a part of the water were distilled off under reduced pressure at a temperature of 50°C or lower, and then the solid content concentration of the aqueous dispersion was measured. The solid content concentration of the aqueous dispersion was adjusted to 20 mass% with deionized water to obtain a core resin dispersion. The volume median diameter (D 50 ) of the resin particles in the dispersion was 200 nm and the CV value was 24%.

[0129] <Preparation of shell resin dispersion> 600 g of methyl ethyl ketone was charged into a 5-liter container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, and 150 g of resin AL1 was added and dissolved at 60°C. To the resulting solution, an aqueous 5 mass% sodium hydroxide solution was added to a neutralization degree of 60 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes to obtain a mixture. Subsequently, 675 g of deionized water was added over 77 minutes. Then, while stirring at 250 r / min, methyl ethyl ketone and a part of the water were distilled off under reduced pressure at a temperature of 50°C or lower, and then the solid content concentration of the aqueous dispersion was measured. The solid content concentration of the aqueous dispersion was adjusted to 20 mass% with deionized water to obtain a shell resin dispersion. The volume median diameter (D 50 ) of the resin particles in the dispersion was 110 nm and the CV value was 20%.

[0130] <Preparation of colorant dispersion> In a 1-liter beaker, 116.2 g of the coloring agent "FASTOGEN SUPER MAGENTA R3-E" (manufactured by DIC Corporation, quinacridone pigment, PR122), 154.9 g of the anionic surfactant "NEOPELEX® G-15" (manufactured by Kao Corporation, 15% by mass sodium dodecylbenzenesulfonate aqueous solution), and 260 g of deionized water were mixed and dispersed at room temperature for 3 hours using a homogenizer. Then, deionized water was added to obtain a coloring agent dispersion with a solid content concentration of 24% by mass. The median particle size (D) of the coloring agent particles in the dispersion was measured. 50 The wavelength was 125nm, and the CV value was 27%.

[0131] <Preparation of mold release agent dispersion> 50g of Fischer-Tropsch wax (manufactured by Nippon Seiro Co., Ltd., trade name: FNP0090, melting point: 90℃), 5g of cationic surfactant (manufactured by Kao Corporation, trade name: Sanizol B50), and 200g of deionized water were heated to 95℃, and the wax was dispersed using a homogenizer. After further dispersion treatment with a pressure-discharge type homogenizer, deionized water was added to obtain a release agent dispersion with a solid content of 20% by mass. The median particle size (D) of the release agent particles in the dispersion was measured. 50 The wavelength was 550nm, and the CV value was 26%.

[0132] <Preparation of toner particles> In a 3-liter four-necked flask equipped with a reflux condenser, a stirrer, and a thermocouple, 500 g of the core resin dispersion, 58 g of the coloring agent dispersion, 33 g of the mold release agent dispersion, and 3.3 g of 15% by mass sodium dodecylbenzenesulfonate aqueous solution "Neoperex G-15" (manufactured by Kao Corporation, anionic surfactant) were mixed at a temperature of 25°C. Next, while stirring the resulting mixture at 25°C, a solution prepared by dissolving 40 g of ammonium sulfate in 570 g of deionized water and adding a 4.8% by mass potassium hydroxide aqueous solution to adjust the pH to 8.2 was added dropwise over 10 minutes, and the temperature was raised to 62°C over 2 hours to determine the volume-median particle size (D) of the aggregated particles. 50 The mixture was maintained at 62°C until it reached a size of 6.9 μm, and a dispersion of aggregated particles (I) was obtained.

[0133] While maintaining the temperature of the dispersion of the obtained aggregated particles (I) at 62°C, 500 g of the shell resin dispersion was added dropwise at a rate of 0.6 mL / min (0.6 g / min) to obtain a dispersion of aggregated particles (II). The median volume particle size (D) of the aggregated particles (II) 50 The diameter was 7.0 μm.

[0134] To the dispersion of the obtained aggregated particles (II), an aqueous solution was added, which consisted of 20 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 40 g of 0.1 mol / L sulfuric acid aqueous solution. The mixture was then heated to 80°C over 1 hour, held at 80°C for 30 minutes, and then 10 g of 0.1 mol / L sulfuric acid aqueous solution was added, followed by a further 15 g of 0.1 mol / L sulfuric acid aqueous solution. The mixture was then held at 80°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles (core-shell particles) in which the aggregated particles had fused together.

[0135] The obtained core-shell particle dispersion was cooled to 30°C, and the dispersion was filtered by suction to separate the solid components. The dispersion was then washed with deionized water at 25°C and filtered by suction at 25°C for 2 hours. Subsequently, toner particles were obtained by vacuum drying at 33°C for 24 hours using a vacuum constant-temperature dryer "DRV622DA" (manufactured by ADVANTEC). The median particle size (D) of the obtained toner particles was measured. 50 The particle size was 7.0 μm, and the circularity was 0.970. The composition ratio (mass ratio) of the binder resin of the obtained toner particles was resin AH1 / resin AL1 = 50 / 50.

[0136] 100 parts by mass of the obtained toner particles and 1 part by mass of "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic silica, hydrophobic treatment agent: DMDS, average particle size: 16 nm) and 2 parts by mass of "RY-50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic silica, hydrophobic treatment agent: silicone oil, average particle size: 40 nm) as external additives were mixed in a Henschel mixer at a rotation speed of 3000 r / min (peripheral speed 32 m / sec) for 3 minutes to obtain magenta toner.

[0137] Test Example 1 [Printed Material Image Density] Toner was mounted on the non-magnetic single-component developer "COREFIDO C712dnw" (manufactured by OKI Electric Industry Co., Ltd.), and the toner adhesion amount was 0.80 mg / cm². 2 A solid image was printed on high-quality paper "J Paper A4 size" (manufactured by Fujifilm Business Innovation Co., Ltd.) without fixing it. Furthermore, the fuser of a "COREFIDO C712dnw" (manufactured by Oki Electric Industry Co., Ltd.) was modified into an external fuser with a fixing speed of 100 mm / sec, and the fixing temperature was set to 180°C to fix the unfixed image. The reflective image density of the solid image portion of the printed material was measured using a colorimeter "SpectroEye" (manufactured by X-Rite, lighting conditions: standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard), and the average of the values ​​measured at three arbitrary points on the image was used as the image density. The results are shown in Table 5. A higher value indicates better image density.

[0138] Test Example 2 [Weather Resistance of Printed Materials] Toner was mounted on the non-magnetic single-component developer "COREFIDO C712dnw" (manufactured by OKI Electric Industry Co., Ltd.), and the toner adhesion amount was 0.80 mg / cm². 2 The resulting solid image was printed on high-quality paper "J Paper A4 size" (manufactured by Fujifilm Business Innovation Co., Ltd.) without fixing it. Furthermore, the fuser of the "COREFIDO C712dnw" (manufactured by Oki Electric Industry Co., Ltd.) was modified into an external fuser with a fixing speed of 100 mm / sec, and the fixing temperature was set to 180°C to fix the unfixed image.

[0139] The obtained fixed images were subjected to weather resistance testing using a xenon weatherometer under the following conditions.

[0140] • Irradiation test machine: SX75, manufactured by Suga Test Machine Co., Ltd. • Light source: Xenon lamp Filter: Inner = Quartz filter, Outer = #275 Panel temperature: 50℃ ·Battle humidity: 35~50%RH ·Irradiation intensity: 50 (W / m 2 ), measured values ​​at 300-400 (nm) • Cumulative illuminance: 40,000 (kJ / m 2 ), integrated value at 300-400 (nm)

[0141] Using a SpectroEye colorimeter (manufactured by X-Rite, under the following lighting conditions: standard light source D50, observation field of view 2°, density reference DINNB, absolute white reference), the values ​​measured at three arbitrary points on the image were averaged, and the hue change (ΔE) was calculated based on the following formula. The results are shown in Table 5. A smaller ΔE indicates better weather resistance.

[0142] ΔE=[(L * 1-L * 2) 2 +(a * 1-a * 2) 2 +(b * 1-b * 2) 2 ] 1 / 2 L * 1, a * 1, b * 1: L before irradiation * a * b * value L * 2, a * 2, b * 2: L after irradiation * a * b * value

[0143] [Table 5]

[0144] From the above results, it can be seen that the toners of Examples 1 to 21 have high image density and good weather resistance. In contrast, the toner of Comparative Example 1, which contains an amorphous polyester resin without PET, shows improved dispersibility of the quinacridone pigment due to increased kneading strength, and although there are no major problems with image density, the weather resistance is significantly reduced. The toner of Comparative Example 2, which contains an amorphous polyester resin using ethylene glycol and terephthalic acid instead of PET, does not have sufficient weather resistance, and the decrease in image density is particularly significant. [Industrial applicability]

[0145] The electrostatic image developing toner of the present invention is suitably used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

Claims

1. A toner for developing electrostatic images, comprising a binder resin containing an amorphous polyester resin A and a colorant, wherein the amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and the colorant contains a quinacridone-based pigment.

2. The electrostatic image developing toner according to claim 1, wherein the polyethylene terephthalate content is 5 mol% or more and 75 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.

3. The electrostatic image developing toner according to claim 1 or 2, wherein the IV value of polyethylene terephthalate is 0.40 or more and 0.85 or less.

4. The toner for developing electrostatic images according to claim 1 or 2, wherein the quinacridone pigment is a quinacridone pigment that does not contain a chloro group.

5. The toner for developing electrostatic images according to claim 1 or 2, wherein the quinacridone pigment is C.I. Pigment Red 122.

6. The electrostatic image developing toner according to claim 1 or 2, wherein the amorphous polyester resin A is a polycondensate obtained by reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate in the presence of a titanium-based catalyst.

7. A method for producing electrostatic image developing toner according to claim 1 or 2, comprising the steps of melting and kneading at least a binder resin and a colorant, and pulverizing the kneaded product obtained in the step.

8. A method for producing electrostatic image developing toner according to claim 7, wherein melt kneading is performed using an open-roll type kneader.

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