Toner and toner manufacturing method

Abstract

To provide a toner that achieves excellent image density stability, while maintaining high image density.SOLUTION: A toner has toner particles containing an organic pigment and a binder resin. In solid NMR measurement at 60°C using a solid content as a sample which is extracted according to a specific procedure for dissolving the toner in chloroform, the transverse relaxation time T2 of a peak observed between 1.5 ppm and 2.5 ppm is 0.08 ms or more and 0.13 ms or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a toner used in an electrophotographic image forming method and a method for producing the toner. [Background technology]

[0002] In recent years, electrophotographic full-color copiers have become widespread, and there is a demand for high speed, high image quality, high productivity, and low cost. To achieve such high image quality, it is known that the image density of printed matter can be increased by finely dispersing pigments in toner (Patent Document 1). Also, a technique is known in which inexpensive fillers are used to reduce the amount of toner raw materials used in order to achieve cost reduction (Patent Document 2).Furthermore, a technique is known in which a dispersant is blended with a pigment to improve the dispersibility of the pigment (Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-099422 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-114828 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-067285 Summary of the Invention [Problem to be solved by the invention]

[0004] However, it has been found that the toner described in the above document has room for improvement in terms of image density stability. The present disclosure provides a toner and a method for producing the toner that achieves excellent image density stability while maintaining high image density. [Means for solving the problem]

[0005] The present disclosure provides a toner having toner particles containing an organic pigment and a binder resin, In solid-state NMR measurements at 60 ° C. using the solid matter extracted in the following (Procedure 1) as a sample, The toner has a transverse relaxation time T2 of a peak observed at 1.5 ppm to 2.5 ppm of 0.08 ms or more and 0.13 ms or less. (Step 1) A sucrose concentrate was prepared by adding 160 g of sucrose to 100 mL of ion-exchanged water and dissolving it in a hot water bath. A centrifuge tube was charged with 31 g of the sucrose concentrate and 6 mL of surfactant to prepare a dispersion. 2.0 g of toner was added to the dispersion, and the toner clumps were broken down using a spatula. The centrifuge tube was then shaken in a shaker. After shaking, the solution was centrifuged at 3,500 rpm for 30 minutes with a 3 cm radius to remove the precipitate. The floating solids were filtered through a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids was dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes with a 3 cm radius. The supernatant was discarded. Another 20 mL of chloroform was added, and the same procedure was repeated twice. The precipitated solids were then dried in a dryer for at least 5 hours to obtain the sample. [Effects of the Invention]

[0006] The present disclosure makes it possible to provide a toner that achieves excellent image density stability while maintaining high image density. DETAILED DESCRIPTION OF THE INVENTION

[0007] In the present disclosure, unless otherwise specified, the expressions "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined in any way.

[0008] The present disclosure provides a toner having toner particles containing an organic pigment and a binder resin, In solid-state NMR measurements at 60 ° C. using the solid matter extracted in the following (Procedure 1) as a sample, The toner has a transverse relaxation time T2 of a peak observed at 1.5 ppm to 2.5 ppm of 0.08 ms or more and 0.13 ms or less. (Step 1) A sucrose concentrate was prepared by adding 160 g of sucrose to 100 mL of ion-exchanged water and dissolving it in a hot water bath. A centrifuge tube was charged with 31 g of the sucrose concentrate and 6 mL of surfactant to prepare a dispersion. 2.0 g of toner was added to the dispersion, and the toner clumps were broken down using a spatula. The centrifuge tube was then shaken in a shaker. After shaking, the solution was centrifuged at 3,500 rpm for 30 minutes with a 3 cm radius to remove the precipitate. The floating solids were filtered through a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids was dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes with a 3 cm radius. The supernatant was discarded. Another 20 mL of chloroform was added, and the same procedure was repeated twice. The precipitated solids were then dried in a dryer for at least 5 hours to obtain the sample.

[0009] The reason why the above toner can achieve both high image density and high image stability is as follows. It is known that if the colorant is finely dispersed within the image layer after toner fixation, visible light absorption occurs efficiently, resulting in an image with high image density. On the other hand, the finer the colorant, the stronger the cohesive force of the colorant, making it more likely to form colorant aggregates within the toner or on the toner surface, where the colorant aggregates and is unevenly distributed. If these colorant aggregates are exposed on the surface of the toner particles, the toner particles are likely to be positively charged due to frictional charging with the carrier in the developer. As a result, the chargeability of the toner particles is impaired, and increasing the number of prints leads to a decrease in image density.

[0010] However, the present inventors have found that the above toner can achieve high image density while also providing excellent image density stability. The reasons for this are believed to be as follows. By the above (Step 1), organic pigments contained in the toner and resin components that are no longer soluble in chloroform due to being bound to the organic pigments are extracted as samples. The peaks observed at 1.5 to 2.5 ppm in solid-state NMR measurements at 60°C reflect the mobility of hydrogen atoms belonging to alkyl groups in the resin. Therefore, it is believed that a gel-like high-molecular-weight resin is bound to the organic pigments contained in the toner that satisfy the above T2. This makes it difficult for the organic pigment to come into contact with the carrier and become charged, and instead the bound high-molecular-weight resin comes into contact with the carrier and becomes charged. This reduces the areas of the toner particles that impair their chargeability, so the toner charge is maintained even when the number of prints is increased, making it less likely that image density will decrease. In particular, we believe that this effect is specifically manifested by the binding of a high-molecular-weight resin with molecular mobility that results in the above-mentioned transverse relaxation time T2 of 0.08 ms to 0.13 ms to the pigment surface, resulting in the above-mentioned effects. Furthermore, toners that satisfy the above T2 have a polymer resin bonded to the surface of the organic pigment, which makes it difficult for secondary pigment aggregates to form during toner manufacturing. This allows the organic pigment to be finely dispersed in the toner, achieving high image density.

[0011] Each of the components of the toner will be described below. <Organic pigments> The toner particles contain an organic pigment. The organic pigment preferably includes at least one selected from the group consisting of a magenta pigment, a cyan pigment, and a yellow pigment. Furthermore, an organic pigment having an unsaturated bond (preferably a conjugated double bond) is preferred because it has a reactive site that facilitates bonding of the resin to the pigment surface. Specific examples include the following:

[0012] Examples of cyan pigments include CI Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, and 17; CI Vat Blue 6; CI Acid Blue 45; and copper phthalocyanine pigments having one to five phthalimidomethyl groups substituted on the phthalocyanine skeleton. From the viewpoint of color development, CI Pigment Blue 15:3 is preferred.

[0013] Examples of pigments for magenta toner include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; CI Pigment Violet 19; CI Bat Red 1, 2, 10, 13, 15, 23, 29, 35. From the viewpoint of color development, CI Pigment Red 122 is preferred.

[0014] Examples of yellow pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, and 185; CI Vat Yellow 1, 3, and 20. From the viewpoint of color development, CI Pigment Yellow 180 is preferred.

[0015] The organic pigment is more preferably at least one selected from the group consisting of CI Pigment Blue 15:3, CI Pigment Red 122, and CI Pigment Yellow 180.

[0016] The organic pigment can be removed from the toner particles by the following procedure 1. (Step 1) A sucrose concentrate was prepared by adding 160 g of sucrose to 100 mL of ion-exchanged water and dissolving it in a hot water bath. A centrifuge tube was charged with 31 g of the sucrose concentrate and 6 mL of surfactant to prepare a dispersion. 2.0 g of toner was added to the dispersion and the toner clumps were broken down using a spatula. The centrifuge tube was then shaken in a shaker. After shaking, the solution was centrifuged at 3,500 rpm for 30 minutes with a 3 cm radius to remove the precipitate. The floating solids were filtered through a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids was dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes with a 3 cm radius. The supernatant was discarded. Another 20 mL of chloroform was added, and the same procedure was repeated twice. The precipitated solids were then dried in a dryer for at least 5 hours to obtain the sample.

[0017] An example of a surfactant is Contaminon N (manufactured by Wako Pure Chemical Industries, Ltd.), which is a 10% by mass aqueous solution of a neutral detergent for cleaning precision measuring instruments, having a pH of 7, and which is composed of a nonionic surfactant, an anionic surfactant, and an organic builder. The shaker used is a YS-LD manufactured by Yayoi Co., Ltd., and the mixture is shaken at 200 rpm for 1 minute. The centrifuge used is a Front Lab FLD2012 (manufactured by AS ONE Corporation).

[0018] The organic pigment extracted here is bound to a polymer resin. In solid-state NMR measurements at 60°C using the solid content obtained in step 1 above as a sample, the transverse relaxation time T2 of the peak observed between 1.5 ppm and 2.5 ppm must be 0.08 ms or more and 0.13 ms or less.

[0019] The peak observed between 1.5 ppm and 2.5 ppm reflects the mobility of hydrogen atoms attributed to the alkyl groups of the resin. The fact that a resin with an alkyl group with such a short transverse relaxation time T2 is bonded to an organic pigment suggests that a high-molecular-weight resin with low mobility, similar to a gel, is bonded to the organic pigment. This results in a sufficient thickness of high-molecular-weight resin on the pigment surface, which prevents contact between the pigment surface and the carrier during the electrophotographic process and suppresses fluctuations in the charge of the toner particles.

[0020] One method for obtaining solids with such a transverse relaxation time is to knead an organic pigment with a high-molecular-weight resin under strong shear, and then bond mechanoradicals generated in the resin to the surface of the organic pigment. The transverse relaxation time T2 of the resulting solids can be controlled by adjusting the molecular weight of the resin. For example, increasing the molecular weight of the resin tends to shorten the transverse relaxation time T2. The transverse relaxation time T2 is preferably 0.09 ms or more and 0.12 ms or less, more preferably 0.10 ms or more and 0.12 ms or less, and even more preferably 0.10 ms or more and 0.11 ms or less. Within the above range, better image density and image density stability are obtained.

[0021] Here, in the solid content extracted by step 1, the resin content per 100 parts by mass of organic pigment is preferably 3.0 parts by mass or more and 50.0 parts by mass or less. By setting it in this range, the chargeability of the toner particles is well maintained and fluctuations in image density are less likely to occur. If it is 50 parts by mass or less, crosslinking between organic pigments can be suppressed, pigment dispersibility is improved, and image density is further improved.

[0022] The ratio of resin to pigment can be controlled, for example, by changing the molecular weight of the resin or by changing the number of times of kneading. In the solid content extracted by step 1, the content of the resin relative to 100 parts by mass of the organic pigment is more preferably 4.0 parts by mass or more and 10.0 parts by mass or less, even more preferably 4.5 parts by mass or more and 8.0 parts by mass or less, and even more preferably 5.0 parts by mass or more and 6.0 parts by mass or less. When the content is within the above range, better image density and image density stability are exhibited.

[0023] Furthermore, the number-average particle diameter of the organic pigment when the solid content extracted in step 1 above is observed with a scanning electron microscope is defined as DA. Furthermore, the solid content is stirred with a stirring device, dispersed in water with an impact disperser, and the resulting dispersion is observed with a dynamic light scattering particle size distribution analyzer, whereupon the number-average particle diameter is defined as DB. In this case, it is preferable that the DA / DB ratio be 2.2 or greater. When the ratio is within this range, the mobility of the organic pigment in the solvent decreases, suggesting that the resin is adsorbed to the organic pigment. This allows for better chargeability of the toner particles and reduces fluctuations in image density.

[0024] Here, DA / DB is preferably 2.3 or more. There is no particular upper limit to DA / DB, but it is preferably 3.0 or less, and more preferably 2.6 or less. Within the above range, better image density and image density stability are exhibited. The DA / DB value can be controlled, for example, by changing the molecular weight of the resin.

[0025] <Binder resin> The toner particles contain a binder resin. Known polymers can be used as the binder resin. Specifically, for example, the following polymers can be used: Examples of suitable styrene copolymers include polystyrene, poly-p-chlorostyrene, polyvinyltoluene, and other styrene and substituted styrene homopolymers; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, styrene-α-chloromethyl methacrylate copolymers, styrene-acrylonitrile copolymers, styrene-vinyl methyl ether copolymers, styrene-vinyl ethyl ether copolymers, styrene-vinyl methyl ketone copolymers, and styrene-acrylonitrile-indene copolymers; polyvinyl chloride, phenolic resins, natural resin-modified phenolic resins, natural resin-modified maleic acid resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyester resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone-indene resins, and petroleum-based resins. These resins may be used alone or in combination.

[0026] Among these, it is preferable that the binder resin contains a polyester resin from the viewpoint of the chargeability of the toner particles. Furthermore, it is preferable that the toner particles contain a polyester resin A and a polyester resin B. It is preferable that the polyester resin A and the polyester resin B are amorphous polyester resins.

[0027] The weight average molecular weight of the polyester resin A is preferably 3,000 to 50,000, more preferably 5,000 to 30,000, and even more preferably 8,000 to 15,000. The weight average molecular weight of the polyester resin B is preferably 500,000 to 2,300,000, more preferably 700,000 to 2,000,000, and even more preferably 1,000,000 to 1,500,000. From the viewpoint of charge stability, it is preferable that polyester resin B is bonded to the surface of the organic pigment.

[0028] It is preferable that polyester resin A and polyester resin B have the same monomer unit. In this case, the charge stability is improved. The monomer unit refers to the form in which the monomer substance in the polymer is reacted. The polyester resin is preferably a condensation polymer of a polyhydric alcohol compound and a polycarboxylic acid compound.

[0029] Examples of polyhydric alcohol compounds include alkylenes of bisphenol A such as polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(2.0)-polyoxyethylene(2.0)-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene(6)-2,2-bis(4-hydroxyphenyl)propane. Examples of the resin include oxide adducts, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and derivatives thereof. The derivatives are not particularly limited as long as they can be obtained by condensation polymerization with a similar resin structure. For example, derivatives obtained by esterifying an alcohol component are included.

[0030] The polyhydric alcohol compound is an alkylene oxide adduct of bisphenol A. It is preferable to use at least one selected from the group consisting of: The proportion of the alkylene oxide adduct of bisphenol A in the polyhydric alcohol compound is preferably 50 to 100 mol %, more preferably 70 to 100 mol %, and even more preferably 90 to 100 mol %.

[0031] Polycarboxylic acid compounds include aromatic dicarboxylic acids or their anhydrides such as phthalic acid, isophthalic acid, and terephthalic acid; alkyl dicarboxylic acids or their anhydrides such as succinic acid, adipic acid, sebacic acid, and azelaic acid; and alkyl groups having 6 to 18 carbon atoms. or alkenyl-substituted succinic acid or its anhydride; unsaturated dicarboxylic acids or their anhydrides such as fumaric acid, maleic acid, and citraconic acid; and derivatives thereof. The derivatives are not particularly limited as long as they can be used to obtain a similar resin structure by condensation polymerization. For example, derivatives in which the carboxylic acid component is methyl esterified, ethyl esterified, or acid chlorided can be used.

[0032] Among the polycarboxylic acid compounds, examples of trivalent or higher carboxylic acid components include trimellitic acid, trimellitic anhydride, and pyromellitic acid. As the polycarboxylic acid compound, aromatic dicarboxylic acids and trimellitic acid or its anhydride are preferred, and terephthalic acid and trimellitic acid or its anhydride are more preferred. The content of aromatic dicarboxylic acids such as terephthalic acid in the polycarboxylic acid compound is preferably 60 to 95 mol%, more preferably 70 to 90 mol%, and even more preferably 75 to 85 mol%. The content of trimellitic acid or its anhydride in the polycarboxylic acid compound is preferably 5 to 35 mol%, more preferably 10 to 30 mol%, and even more preferably 15 to 25 mol%.

[0033] Polyester resin A and polyester resin B preferably contain a monomer unit of an alkylene oxide adduct of bisphenol A, a monomer unit of terephthalic acid, and a monomer unit of trimellitic acid. That is, polyester resin A and polyester resin B are preferably condensation polymers of monomers containing an alkylene oxide adduct of bisphenol A, terephthalic acid, and trimellitic acid or its anhydride. In this case, the charge stability is improved. Furthermore, the inclusion of trimellitic acid tends to result in a resin containing a gel component, which in such cases tends to bond with the pigment during kneading, as described below.

[0034] The content of polyester resin A in the toner particles is preferably 60% by mass to 78% by mass, more preferably 70% by mass to 76% by mass. The content of polyester resin B in the toner particles is preferably 1% by mass to 10% by mass, more preferably 2% by mass to 5% by mass.

[0035] Furthermore, the toner particles preferably contain a crystalline polyester resin in addition to the binder resin. The crystalline polyester facilitates plasticization of the polyester resin bonded to the organic pigment surface. This facilitates loosening of the organic pigment particles in the toner during toner production, improving the dispersibility of the organic pigment, and thereby increasing the density of the resulting image.

[0036] The content of the crystalline polyester in the toner particles is preferably 1.0% by mass or more and 10.0% by mass or less, more preferably 2.0% by mass or more and 7.0% by mass or less, and even more preferably 3.0% by mass or more and 5.0% by mass or less. When the content is 1.0% by mass or more, the above-mentioned effects are easily achieved. When the content is 10.0% by mass or less, aggregation of the pigment in the toner during fixing can be suppressed, and image density is easily increased.

[0037] <Calcium carbonate particles> The toner particles preferably contain calcium carbonate particles. The content of calcium carbonate particles in the toner particles is preferably 3.0% by mass or more and 15.0% by mass or less. When the content is 3.0% by mass or more, the effect of pulverizing the pigment during kneading is enhanced, and color development is more likely to be improved. When the content is 15.0% by mass or less, color development can be further improved while suppressing light scattering by the calcium carbonate particles. The content of calcium carbonate particles in the toner particles is more preferably 3.5% by mass or more and 14.0% by mass or less, and even more preferably 5.0% by mass or more and 10.0% by mass or less.

[0038] When the toner is subjected to X-ray diffraction measurement using CuKα radiation, peaks are preferably present in the diffraction angle (2θ) range of 26.5°±0.1° and the diffraction angle (2θ) range of 29.5°±0.1°. The crystallite size of calcium carbonate calculated from the peak in the diffraction angle (2θ) range of 29.5°±0.1° is preferably 10 nm or more and 45 nm or less. Furthermore, the ratio of the peak intensity in the diffraction angle (2θ) range of 26.5°±0.1° to the peak intensity in the diffraction angle (2θ) range of 29.5°±0.1° (peak intensity at 26.5°±0.1° / peak intensity at 29.5°±0.1°) is preferably 0.15 or more and 0.24 or less. By forming calcium carbonate particles in this state, higher color development can be achieved.

[0039] Here, the crystallite size of the calcium carbonate particles calculated from the peak in the range of diffraction angle (2θ) = 29.5° ± 0.1° is more preferably 20 nm or more and 45 nm or less, and even more preferably 25 nm or more and 40 nm or less. The crystallite size can be controlled by changing the concentrations of the calcium carbonate particles and pigment in the first kneading step described below. Increasing the concentrations of the calcium carbonate particles and pigment results in kneading conditions with higher shear stress, resulting in a smaller crystallite size of the calcium carbonate particles.

[0040] Furthermore, the ratio of the peak intensity in the diffraction angle (2θ) range of 26.5°±0.1° to the peak intensity in the diffraction angle (2θ) range of 29.5°±0.1° is more preferably 0.16 or more and 0.23 or less, and even more preferably 0.17 or more and 0.22 or less. This ratio value can also be controlled by changing the concentrations of calcium carbonate particles and pigment in the first kneading step described below. Increasing the concentrations of calcium carbonate particles and organic pigment results in kneading conditions with greater shear stress, increasing the value of the ratio.

[0041] <Release agent> If necessary, a release agent may be used to suppress the occurrence of hot offset during the heat fixing of the toner. Typical examples of the release agent include low-molecular-weight polyolefins, silicone wax, fatty acid amides, ester waxes, carnauba wax, and hydrocarbon waxes.

[0042] <External additives> If necessary, external additives may be added to the toner particles. Examples of external additives include inorganic particles such as silica, alumina, titania, and calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin.

[0043] Here, it is preferable to use strontium titanate particles as the external additive. That is, the toner contains toner particles and an external additive, and the external additive preferably contains strontium titanate particles. By using particles with high dielectric constant and low resistance such as strontium titanate particles as the external additive, excess charge in the binder resin, such as polyester resin, bonded to the organic pigment is removed during the toner charging and development process. This suppresses initial charging, resulting in improved image density stability.

[0044] The content of strontium titanate particles in the toner is preferably 0.1 to 1.0 parts by weight, more preferably 0.1 to 0.9 parts by weight, per 100 parts by weight of toner particles. When the content is 0.1 parts by weight or more, the effect of charge stability is more easily exhibited. When the content is 1.0 part by weight or less, charge leakage can be suppressed, and image density stability is more easily improved.

[0045] <Toner manufacturing method> The method for producing the toner is not particularly limited, and known methods such as emulsion aggregation, kneading and pulverization, and suspension polymerization can be used. The kneading and pulverization method is preferred. The kneading and pulverization method will be described below.

[0046] First, predetermined amounts of materials constituting the toner particles, such as binder resin and organic pigment, and optionally other components such as calcium carbonate particles and a release agent, are weighed, blended, and mixed. Examples of mixing devices include a double cone mixer, a V-type mixer, a drum mixer, a super mixer, a Henschel mixer, a Nauta mixer, and a Mechano Hybrid (manufactured by Nippon Coke and Engineering Co., Ltd.).

[0047] Next, the mixed materials are melt-kneaded. In the melt-kneading step, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used, but a single-screw or twin-screw extruder is preferred because of its advantage of allowing continuous production. The melt-kneading temperature is preferably about 100 to 200°C.

[0048] The toner manufacturing method preferably includes a first kneading step in which a portion of the binder resin (preferably a portion of polyester resin A and polyester resin B) and an organic pigment (preferably further with calcium carbonate particles) are melt-kneaded to obtain a pigment mixture, and a second kneading step in which the pigment mixture and the remainder of the binder resin (preferably the remainder of polyester resin A) are melt-kneaded to obtain a resin composition. In the first kneading step, the total content of polyester resin A and polyester resin B in the pigment mixture is preferably 20% to 50% by mass, and the content of the organic pigment in the pigment mixture is preferably 20% to 60% by mass. Furthermore, in the second kneading step, the total content of polyester resin A and polyester resin B in the resin composition is preferably 50% to 80% by mass, and the content of the organic pigment in the resin composition is preferably 3% to 20% by mass.

[0049] Here, in the first kneading step, polyester resin B and the organic pigment are kneaded under high shear stress because the mixture contains a high proportion of solids that do not melt during kneading, such as organic pigments and calcium carbonate particles, which are added as needed. Under these conditions, it is thought that the molecular chains of polyester resin B are scissed by kneading, generating mechanoradicals that cause polyester resin B to bond to the surface of the organic pigment. The organic pigment thus produced, with polyester resin B bonded to its surface, has excellent charge stability.

[0050] Here, the higher the molecular weight of polyester resin B, the greater the amount of mechano radicals generated, which further promotes bonding to the pigment.When the molecular weight is low, mechano radicals are less likely to be generated by kneading, making bonding to the pigment less likely to occur.

[0051] In the first kneading step, the total content of polyester resin A and polyester resin B in the pigment mixture is more preferably 25% by mass to 40% by mass, and even more preferably 28% by mass to 35% by mass. The content of polyester resin B in the pigment mixture is preferably 5% by mass to 30% by mass, more preferably 10% by mass to 20% by mass, and even more preferably 13% by mass to 17% by mass. The content of the organic pigment in the pigment mixture is preferably 2. It is more preferably 5% by mass to 40% by mass. The content of calcium carbonate particles in the pigment mixture is preferably 10% by mass to 50% by mass, and more preferably 30% by mass to 45% by mass.

[0052] In the second kneading step, the total content of polyester resin A and polyester resin B in the resin composition is more preferably 70% by mass to 80% by mass. The content of the organic pigment in the resin composition is more preferably 4% by mass to 10% by mass. The content of polyester resin A in the resin composition is preferably 60% by mass to 78% by mass, more preferably 70% by mass to 76% by mass. The content of polyester resin B in the resin composition is preferably 1% by mass to 10% by mass, more preferably 2% by mass to 5% by mass. The content of calcium carbonate particles in the resin composition is preferably 3% by mass to 15% by mass, more preferably 5% by mass to 10% by mass.

[0053] Examples of kneading devices that can be used include a KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), a TEM twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), a PCM kneader (manufactured by Ikegai Iron Works), a twin-screw extruder (manufactured by KCK Corporation), a Co-Kneader (manufactured by Buss Co., Ltd.), and Kneedex (manufactured by Nippon Coke and Engineering Co., Ltd.) Furthermore, the resin composition obtained by melt kneading is rolled using a twin roll or the like, and quenched with water or the like in a cooling step.

[0054] The cooled resin composition is then crushed to a desired particle size in a crushing process. In the crushing process, the resin composition is coarsely crushed using a crusher such as a crusher, hammer mill, or feather mill. The resin composition is then further crushed into fine particles using a crusher such as a Kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), a Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), a Turbo Mill (manufactured by Turbo Kogyo Co., Ltd.), or an air jet type crusher, to obtain toner particles.

[0055] Thereafter, if necessary, the toner particles may be classified using a classifier or sieve such as an inertial classification type Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), a centrifugal classification type Turboplex (manufactured by Hosokawa Micron Corporation), a TSP Separator (manufactured by Hosokawa Micron Corporation), or a Faculty (manufactured by Hosokawa Micron Corporation), to obtain classified toner particles.

[0056] The weight-average particle size of the toner particles is preferably 4 to 12 μm, more preferably 5 to 8 μm. The toner particles produced through the above process may be used as a toner as is. If necessary, inorganic fine particles such as silica, alumina, titania, and calcium carbonate, or resin fine particles such as vinyl resin, polyester resin, and silicone resin may be added to the toner particles by applying shear force in a dry state. These inorganic fine particles and resin fine particles function as external additives such as flow aids and cleaning aids. The content of the external additive is preferably 1.0 to 10.0 parts by mass, more preferably 2.0 to 5.0 parts by mass, per 100 parts by mass of the toner particles.

[0057] The toner can be used as a one-component developer, or may be mixed with a magnetic carrier to be used as a two-component developer. As the magnetic carrier, for example, generally known magnetic materials such as surface-oxidized iron powder, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earth elements, alloy particles thereof, oxide particles, and ferrite, and magnetic material-dispersed resin carriers (so-called resin carriers) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state can be used.

[0058] When the toner is mixed with a magnetic carrier to be used as a two-component developer, the carrier mixing ratio in this case is preferably 2% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 13% by mass or less, in terms of the toner concentration in the two-component developer, and generally good results can be obtained. .

[0059] The methods for measuring each physical property are described below. <Transverse relaxation time T2 measurement> Measurement of the transverse relaxation time T2 using solid-state NMR is carried out as follows. The solid sample obtained by the above-mentioned procedure 1 is placed in a sample cell, and measurement is carried out under the following conditions. Equipment: JNM-ECA400-II manufactured by JEOL Ltd. Probe: 4mm MAS probe Sample rotation speed: 10kHz Measurement temperature: 60℃ Measurement nuclei: 1 H(proton) Measurement range: 5±125[ppm] Pulse mode: spin echo mode 90 degree pulse width: 3.121μsec 180 degree pulse width: 6.242 μsec Total echo time :0.3μs, 0.45μs, 0.69μs, 1.04μs, 1.58μs, 2.38μs, 3.61μs, 5.46μs, 8.27μs, 12.52μs, 18.96μs, 28.7μs, 43.44μs, 65.76μs, 99.54μs, 150.69μs, 228.11μs, 30 points: 345.31μs, 522.72μs, 791.28μs, 1.19783ms, 1.81326ms, 2.74488ms, 4.15516ms, 6.29ms, 9.5217ms, 14.4138ms, 21.819ms, 33.03ms, 50ms Repeat interval: 5 seconds Number of repetitions: 8 Number of data points: 1024

[0060] The obtained results are subjected to regression analysis calculations using JEOL's analysis software "Delta." Peaks between 1.0 ppm and 2.5 ppm are selected as the peaks to be analyzed, and the observed relaxation curve is fitted to f(t) = f(0) exp(-t / T2) in the analysis mode "Unweighted Linear Spin Lock mode" to determine the transverse relaxation time T2 [ms].

[0061] <Mass ratio of resin to pigment in the solid content obtained in step 1> The solid content separated from the toner by the method described in step 1 above is measured using a thermogravimetric / differential thermal analyzer (Rigaku Corporation, differential thermal balance TG-DTA, ThermoPlusTG8120). The temperature is raised from 25°C to 400°C at a rate of 10°C / min, and the amount of resin adsorbed is measured from the change in weight.

[0062] <Number average particle diameter DA of organic pigments measured using a scanning electron microscope (SEM)> The solid content obtained by the above procedure 1 is observed with a scanning electron microscope (S-4800, Hitachi High-Technologies Corporation). The major diameters of 100 organic pigment particles are measured, and the number-average particle diameter DA is calculated by finding the arithmetic mean value.

[0063] <Number average particle size DB when observed with a dynamic light scattering particle size distribution analyzer> Dodecylbenzenesulfonic acid is added in an amount of 5% by mass to the solid matter separated from the toner particles by the method of step 1 described above, and 3000 parts by mass of ion-exchanged water is further added to 100 parts by mass of the solid matter, and the mixture is stirred at 7000 rpm using an ultra-high speed stirring device TK Robomix (manufactured by Primix). The stirred dispersion is further dispersed using a high-pressure impact type disperser Nanomizer (manufactured by Yoshida Kikai Kogyo). The particles are dispersed at a pressure of 200 MPa. The particles are then measured using a dynamic light scattering particle size distribution analyzer, Nanotrac UPA-EX150, to determine the number average particle size DB. Specific operating conditions are a measurement time of 30 seconds, a refractive index of the sample particles of 1.50, and water as the dispersion medium, with a refractive index of 1.33. The volume particle size distribution of the measurement sample is measured, and the number average particle size is calculated from the measurement results.

[0064] <Identification of resin monomer units> The structure is analyzed using a pyrolysis gas chromatography mass spectrometer (GC-MS) as follows. 300 μg of toner, resin separated from toner, or solid obtained by the method described in Step 1 is embedded in Pyrofoil F590 (see below) and introduced into a pyrolysis furnace. Heat it to 590°C for 5 seconds in an inert (helium) atmosphere. The generated decomposition gas is introduced into the gas chromatograph inlet, and the oven profile is performed as described below. The column outlet is connected to the MS analyzer via a transfer line, and a total ion chromatogram (TIC) is obtained, plotting ion current on the vertical axis and retention time on the horizontal axis. Next, mass spectra are extracted for all detected peaks in the resulting chromatogram using the accompanying software, and compound assignments are performed based on the NIST-2017 database. The measurement device and measurement conditions are as follows. Pyrolysis furnace: Japan Analytical Industry JSP900 (manufactured by Japan Analytical Industry Co., Ltd.) Pyrofoil: F590 (Japan Analytical Industry Co., Ltd.) GC:Agilent Technologies 7890A GC MS: Agilent Technologies 5975C Column: HP-5ms 30 m, inner diameter 0.25 mm, mobile phase thickness 0.25 μm (Agilent) Carrier gas: He (purity 99.9995% or higher) Oven profile: (1) Hold at 40°C for 3 minutes, (2) Heat to 320°C at 10°C / min, (3) Hold at 320°C for 20 minutes Inlet temperature: 280℃ Split ratio: 50:1 Column flow rate: 1 mL / min (quantitative) Transfer line temperature: 280℃ Observation MS range: 30-600 Da Ionization: EI 70eV Ion source temperature: 280℃ Quadrupole temperature: 150℃

[0065] <Measurement of calcium carbonate particle content> A concentrated sucrose solution was prepared by adding 160 g of sucrose to 100 mL of ion-exchanged water and dissolving it in a hot water bath. A centrifuge tube was charged with 31 g of the concentrated sucrose solution and 6 mL of a surfactant (Contaminon N, manufactured by Wako Pure Chemical Industries, Ltd.) to prepare a dispersion. 2.0 g of toner was added to the dispersion, and the toner clumps were broken down using a spatula. The centrifuge tube was then shaken in a shaker. After shaking, the solution was centrifuged at 3,500 rpm for 30 minutes with a rotation radius of 3 cm to remove the precipitate. The floating solids were filtered using a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids was dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes with a rotation radius of 3 cm. The supernatant was discarded. Another 20 mL of chloroform was added, and the same procedure was repeated twice. The precipitated solids were then dried in a dryer for at least 5 hours to obtain the sample. The content of calcium carbonate particles in the solid content thus obtained is measured using a wavelength dispersive X-ray fluorescence analyzer "Axios" (manufactured by PANalytical).

[0066] <X-ray diffraction peak measurement of calcium carbonate particles> X-ray diffraction measurement of calcium carbonate particles in toner was performed using the RINT-TTRII measuring device. Measurements are performed using a CuKα characteristic X-ray spectroscope (manufactured by Rigaku Corporation) at a diffraction angle (2θ±0.20°) ranging from 3° to 35°. From the total integrated intensity of the obtained spectrum, the crystallite size of the crystals attributable to a diffraction angle (2θ) of 29.5°±0.5° and the ratio of the peak intensity of the crystals attributable to a diffraction angle (2θ) of 26.5°±0.5° to the peak intensity of the crystals attributable to a diffraction angle (2θ) of 29.5°±0.5° are determined. Toner is used as the sample. If it is necessary to remove the influence of external additives, these can be removed by the procedure up to the centrifugation at 3500 rpm in Step 1 above. Therefore, toner particles from which the external additives have been removed by this procedure may be used as the sample. The measurement conditions are as follows: X-ray:Cu / 50kV / 300mA Goniometer: Rotor horizontal goniometer (TTR-2) Attachment: Standard sample holder Divergence slit: open Divergence vertical limit slit: 10.00 mm Scattering slit: open Receiving slit: open Counter: Scintillation counter Scanning mode: Continuous Scan speed: 4.0000° / min. Sampling width: 0.0200° Scan axis: 2θ / θ Scanning range: 10.0000~40.0000°

[0067] <Measurement of weight average molecular weight of polyester resin A and polyester resin B> The weight average molecular weights of the polyester resin A and the polyester resin B are measured by gel permeation chromatography (GPC) as follows. First, the object to be measured (polyester resin A, polyester resin B, or toner) is dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution is then filtered through a solvent-resistant membrane filter "Myshoridisc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of components soluble in THF is approximately 0.8% by mass. This sample solution is used for measurements under the following conditions. Apparatus: HLC8120 GPC (detector: RI) (Tosoh Corporation) Column: Shodex KF-801, 802, 803, 804, 805, 806, 80 7-of-7 (Showa Denko) Eluent: tetrahydrofuran (THF) Flow rate: 1.0mL / min Oven temperature: 40.0℃ Sample injection volume: 0.10 mL To calculate the molecular weight of the sample, a molecular weight calibration curve prepared using standard polystyrene resins (trade names: "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500", manufactured by Tosoh Corporation) was used. When a toner is used as a sample, each peak is further separated from the obtained molecular weight distribution curve, and the weight average molecular weight of each polyester resin is calculated.

[0068] <Measurement of Crystalline Polyester Resin Content in Toner Particles> As described below, the content of the crystalline polyester resin can be determined by separating it from the toner by utilizing the difference in solubility in a solvent. First separation: Toner is dissolved in methyl ethyl ketone (MEK) at 23°C, and the soluble matter (binder resin) is separated from the insoluble matter (crystalline polyester resin, release agent, organic pigment, inorganic fine particles, etc.). do. Second separation: The insoluble matter obtained in the first separation (crystalline polyester resin, release agent, organic pigment, inorganic fine particles, etc.) is dissolved in MEK at 100°C, and the soluble matter (crystalline polyester resin, release agent) is separated from the insoluble matter (organic pigment, inorganic fine particles, etc.). Third separation: The soluble matter (crystalline polyester resin, release agent) obtained in the second separation is dissolved in chloroform at 23°C, and the crystalline polyester resin is separated as the soluble matter. After the solvent has been thoroughly dried and removed, the mass is measured, and the crystalline polyester resin content can be determined.

[0069] <Measurement of strontium titanate content in toner> The content of strontium titanate in the toner is measured by fluorescent X-ray measurement in accordance with JIS K 0119-1969, specifically as follows. The measurement equipment used was a wavelength dispersive X-ray fluorescence analyzer "Axios" (PANalytical) and the accompanying dedicated software "SuperQ ver.4.0F" (PANalytical) for setting measurement conditions and analyzing measurement data. Rh was used as the anode of the X-ray tube, the measurement atmosphere was vacuum, the measurement diameter (collimator mask diameter) was 27 mm, and the measurement time was 10 seconds. Light elements were detected using a proportional counter (PC), and heavy elements were detected using a scintillation counter (SC). The measurement sample is prepared by placing 4 g of toner in a special aluminum ring for pressing, flattening it, and then pressing it at 20 MPa for 60 seconds using the tablet molding compressor described below to form a pellet with a thickness of approximately 2 mm and a diameter of approximately 39 mm. Tablet molding and compression machine "BRE-32" (manufactured by Mayekawa Testing Machinery Manufacturing Co., Ltd.) Measurements are carried out under the above conditions, and elements derived from strontium titanate are identified based on the peak positions of the obtained X-rays. The strontium titanate content is then calculated from the counting rate (unit: cps), which is the number of X-ray photons per unit time. [Example]

[0070] The present invention will be described in more detail below using examples and comparative examples, but these are not intended to limit the present invention in any way. In the following formulations, parts are by mass unless otherwise specified.

[0071] <Production of cyan pigment masterbatch CM1> Cyan pigment (PB15:3): 30 parts Calcium carbonate 1 (number average particle size 400 nm): 40 parts Polyester resin A1: 15 parts Polyester resin B1: 15 parts (The monomer compositions and molar ratios of polyester resin A1 and polyester resin B1, as well as the weight average molecular weights, are shown in Table 1.) The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1After mixing for 5 minutes at 120°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation), the mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding a coarsely pulverized cyan pigment masterbatch CM1.

[0072] [Table 1]

[0073] <Production of cyan pigment masterbatches CM2 to CM9> Cyan pigment master batches CM2 to CM9 were obtained in the same manner as cyan pigment master batch CM1, except that the materials were changed as shown in Table 2. [Table 2] In the table, "amount of pigment / polyester resin" indicates the parts by mass of pigment when the amount of polyester resin is 100 parts by mass.

[0074] <Production of cyan pigment masterbatch CM10> The materials were changed to those shown in Table 2, and the mixture was produced in the same manner as in cyan pigment masterbatch CM1. The obtained powder was then mixed in a twin-screw mixer (PCM-30, manufactured by Ikegai Corporation) at 200 rpm and 120°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, to obtain a coarsely pulverized product of cyan pigment masterbatch CM10.

[0075] <Production of cyan masterbatch CM11> The materials were changed as shown in Table 2, and the resulting powder was kneaded in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation) at 200 rpm and 120°C. The resulting kneaded product was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding coarsely pulverized cyan pigment masterbatch CM11.

[0076] <Production of cyan pigment masterbatches CM12 to CM14> Cyan pigment master batches CM12 to CM14 were obtained in the same manner as in cyan pigment master batch CM1, except that the materials were changed as shown in Table 2.

[0077] <Production of Cyan Toner CT1> Polyester resin A1: 72 parts Pigment Masterbatch CM1: 20 parts 1 part synthetic wax: 8 parts (Hydrocarbon wax, maximum endothermic peak temperature 90℃) The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1 After mixing for 5 minutes, the mixture was kneaded in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation) at a set temperature of 130°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely pulverized product. The resulting coarsely pulverized product was finely pulverized in a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) by adjusting the rotation speed and number of passes to obtain the target particle size. The mixture was further classified using a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) to obtain toner particles. The rotation speed of a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) was adjusted to obtain the target particle size and particle size distribution, and classification was performed. 100 parts of the obtained toner particles were mixed with a toner having a specific surface area of ​​200 m2 measured by the BET method. 2 1.8 parts of silica particles hydrophobized with silicone oil were added, and the mixture was mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s -1 The mixture was mixed at a rotation time of 10 minutes to obtain a cyan toner CT1.

[0078] <Production example of cyan toner CT2 to CT5> Cyan toners CT2 to CT5 were obtained in the same manner as cyan toner CT1, except that the materials were changed as shown in Table 3. The following crystalline polyester resin C1 was used. (Crystalline polyester resin C1: composition (mol%) [1,6-hexanediol:dodecanedioic acid=100:100], melting point=72°C)

[0079] <Production example of cyan toner CT6> The materials were changed to those shown in Table 3, and toner particles were produced in the same manner as for cyan toner CT1. 100 parts of the obtained toner particles were mixed with a toner having a specific surface area of ​​200 m2 measured by the BET method. 2 / g, 1.8 parts of silica particles hydrophobized with silicone oil, and a specific surface area measured by the BET method of 50 m 2 0.1 parts of strontium titanate (1 / g) was added, and the mixture was mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s. -1 The mixture was mixed at a rotation time of 10 minutes to obtain toner CT6.

[0080] <Production example of cyan toner CT7> Cyan toner CT7 was obtained in the same manner as cyan toner CT6, except that the materials were changed to those shown in Table 3 and the amount of strontium titanate was changed to 0.9 parts.

[0081] <Production example of cyan toner CT8> Cyan toner CT8 was obtained in the same manner as cyan toner CT6, except that the materials were changed to those shown in Table 3 and the amount of strontium titanate was changed to 1.2 parts.

[0082] <Production example of cyan toner CT9-21> Cyan toners CT9 to CT21 were obtained in the same manner as cyan toner CT1, except that the materials were changed as shown in Table 3. Table 3 shows the physical properties of the cyan toners.

[0083] [Table 3] In Tables 3, 5, and 7, the calcium carbonate ratio indicates the content ratio of calcium carbonate particles in the toner particles. The "pigment / polyester resin amount" indicates the mass parts of the pigment when the total of polyester resins A and B is 100 parts. The CPES content indicates the mass of the crystalline polyester resin in the toner particles. The formula indicates the content of the terephthalate resin. T2 is the transverse relaxation time T2 (ms) of the peak observed at 1.5 ppm to 2.5 ppm in solid-state NMR measurement. X is the resin content (parts by mass) per 100 parts by mass of organic pigment in the solid content extracted in step 1. The crystalline size is the calcium carbonate crystallite size calculated from the peak at a diffraction angle (2θ) of 29.5°±0.1° in X-ray diffraction measurement of the toner. The peak intensity ratio is the ratio of the peak intensity at a diffraction angle (2θ) of 26.5°±0.1° to the peak intensity at a diffraction angle (2θ) of 29.5°±0.1° in X-ray diffraction measurement of the toner.

[0084] <Production of magenta pigment masterbatch MM1> Magenta pigment (PR122): 30 parts Calcium carbonate 1 (number average particle size 400 nm): 40 parts Polyester resin A1: 15 parts Polyester resin B1: 15 parts The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1 After mixing for 5 minutes at 120°C in a twin-screw kneader (PCM-30 model, manufactured by Ikegai Corporation), the mixture was kneaded at 200 rpm and 120°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, to obtain a coarsely pulverized magenta pigment masterbatch MM1.

[0085] <Production of magenta pigment masterbatches MM2 to MM9> Magenta pigment master batches MM2 to MM9 were obtained in the same manner as the magenta pigment master batch MM1, except that the materials were changed as shown in Table 4. [Table 4] In the table, "amount of pigment / polyester resin" indicates the parts by mass of pigment when the amount of polyester resin is 100 parts by mass.

[0086] <Production of magenta pigment masterbatch MM10> The magenta pigment masterbatch MM1 was produced in the same manner as for the magenta pigment masterbatch MM1, except for the materials changed as shown in Table 4. The resulting powder was then kneaded in a twin-screw kneader (PMM-30 model, manufactured by Ikegai Corporation) at 200 rpm and 120° C. The resulting kneaded product was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding coarsely pulverized magenta pigment masterbatch MM10.

[0087] <Production of magenta masterbatch MM11> The magenta pigment masterbatch MM11 was produced in the same manner as in MM8, except for changing the materials as shown in Table 4. The resulting powder was then kneaded in a twin-screw kneader (PMM-30 model, manufactured by Ikegai Corporation) at 200 rpm and 120°C. The resulting kneaded product was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding a coarsely pulverized magenta pigment masterbatch MM11.

[0088] <Production of magenta pigment masterbatches MM12 to MM14> Magenta pigment masterbatches MM12 to MM14 were obtained in the same manner as the magenta pigment masterbatch MM1, except that the materials were changed as shown in Table 4.

[0089] <Production of Magenta Toner MT1> Polyester resin A1: 72 parts Pigment Masterbatch MM1: 20 parts 1 part synthetic wax: 8 parts (Hydrocarbon wax, maximum endothermic peak temperature 90℃) The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. - After mixing for 5 minutes, the mixture was kneaded in a twin-screw kneader (PMM-30, manufactured by Ikegai Corporation) at a set temperature of 130°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely pulverized product. The resulting coarsely pulverized product was finely pulverized in a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) by adjusting the rotation speed and number of passes to obtain the target particle size. The mixture was further classified using a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) to obtain toner particles. The rotation speed of a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) was adjusted to obtain the target particle size and particle size distribution, and classification was performed. 100 parts of the obtained toner particles were mixed with a toner having a specific surface area of ​​200 m2 measured by the BET method. 2 1.8 parts of silica particles hydrophobized with silicone oil were added, and the mixture was mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s -1 The mixture was mixed for 10 minutes at a rotation time to obtain a magenta toner MT1.

[0090] <Production example of magenta toner MT2 to MT14> Magenta toners MT2 to MT14 were obtained in the same manner as magenta toner MT1, except that the materials were changed as shown in Table 5. Table 5 shows the physical properties of the magenta toners. [Table 5] The abbreviations in the table are as shown in Table 3. X is the content (parts by mass) of resin relative to 100 parts by mass of organic pigment in the solid content extracted in step 1.

[0091] <Production of yellow pigment masterbatch YM1> Yellow pigment (PY180): 30 parts Calcium carbonate 1 (number average particle size 400 nm): 40 parts Polyester resin A1: 15 parts Polyester resin B1: 15 parts The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1 After mixing for 5 minutes at 120°C in a twin-screw kneader (PCM-30, manufactured by Ikegai Corporation), the mixture was kneaded at 200 rpm and 120°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 µm or less, to obtain a coarsely pulverized product of yellow pigment masterbatch YM1.

[0092] <Production of yellow pigment masterbatches YM2 to YM9> Except for changing the materials shown in Table 6, the same production method as for yellow pigment masterbatch YM1 was used to obtain yellow pigment masterbatches YM2 to YM9. [Table 6] In the table, "amount of pigment / polyester resin" indicates the parts by mass of pigment when the amount of polyester resin is 100 parts by mass.

[0093] <Production of yellow pigment masterbatch YM10> The materials were changed as shown in Table 6, and the resulting powder was kneaded in a twin-screw kneader (PYM-30, manufactured by Ikegai Corporation) at 200 rpm and 120° C. The resulting kneaded product was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding coarsely pulverized yellow pigment masterbatch YM10.

[0094] <Production of Yellow Masterbatch YM11> The materials were changed as shown in Table 6, and the resulting powder was kneaded in a twin-screw kneader (PYM-30, manufactured by Ikegai Corporation) at 200 rpm and 120° C. The resulting kneaded product was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less, yielding coarsely pulverized yellow pigment masterbatch YM11.

[0095] <Production of yellow pigment masterbatches YM12 to YM14> Except for changing the materials shown in Table 6, production was carried out in the same manner as for yellow pigment masterbatch YM1, to obtain yellow pigment masterbatches YM12 to YM14.

[0096] <Production of Yellow Toner YT1> Polyester resin A1: 72 parts Pigment Masterbatch YM1: 20 parts 1 part synthetic wax: 8 parts (Hydrocarbon wax, maximum endothermic peak temperature 90℃) The above materials were mixed in a Henschel mixer (FM-75 model, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s. -1 After mixing for 5 minutes, the mixture was kneaded in a twin-screw kneader (PYM-30, manufactured by Ikegai Corporation) at a set temperature of 130°C. The resulting kneaded mixture was cooled and coarsely pulverized in a pin mill to a volume average particle size of 100 μm or less to obtain a coarsely pulverized product. The resulting coarsely pulverized product was finely pulverized in a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) by adjusting the rotation speed and number of passes to obtain the target particle size. The mixture was further classified using a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) to obtain toner particles. The rotation speed of a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) was adjusted to obtain the target particle size and particle size distribution, and classification was performed. 100 parts of the obtained toner particles were mixed with a toner having a specific surface area of ​​200 m2 measured by the BET method. 2 1.8 parts of silica particles hydrophobized with silicone oil were added, and the mixture was mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s -1 The mixture was mixed at a rotation time of 10 minutes to obtain a yellow toner YT1.

[0097] <Production example of yellow toner YT2 to YT14> Yellow toners YT2 to YT14 were obtained in the same manner as yellow toner YT1, except that the materials were changed as shown in Table 7. Table 7 shows the physical properties of the yellow toners. [Table 7] The abbreviations in the table are as shown in Table 3. X is the content (parts by mass) of resin relative to 100 parts by mass of organic pigment in the solid content extracted in step 1.

[0098] <Magnetic Carrier 1 Manufacturing Example> Number average particle size: 0.30 μm, magnetization strength: 65 Am under a magnetic field of 1000 / 4π (kA / m) 2 / kg) of magnetite 1 Number average particle size: 0.50 μm, magnetization strength: 65 Am under a magnetic field of 1000 / 4π (kA / m) 2 / kg) magnetite2 To 100 parts of each of the above materials, 4.0 parts of a silane compound (3-(2-aminoethylaminopropyl)trimethoxysilane) was added, and the mixture was mixed and stirred at high speed in a container at 100° C. or higher to treat each of the fine particles. Phenol: 10% by weight Formaldehyde solution: 6% by mass (40% by mass of formaldehyde, 10% by mass of methanol, 50% by mass of water) Magnetite treated with the above silane compound 1:58 mass% Magnetite treated with the above silane compound 2: 26 mass% 100 parts of the above material, 5 parts of a 28% by weight aqueous ammonia solution, and 20 parts of water were placed in a flask, and the mixture was heated to 85°C over 30 minutes while stirring and mixing, and then maintained at that temperature for 3 hours to polymerize and harden the resulting phenolic resin. The hardened phenolic resin was then cooled to 30°C, and water was added. The supernatant was removed, and the precipitate was washed with water and air-dried. This was then dried under reduced pressure (5 mmHg or less) at 60°C to obtain spherical magnetic carrier 1 with dispersed magnetic material. The volume-based 50% particle size (D50) of magnetic carrier 1 was 34.2 μm.

[0099] <Manufacturing example of cyan two-component developer CD1> 8.0 parts of cyan toner CT1 was added to 92.0 parts of magnetic carrier 1, and mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain a cyan two-component developer CD1.

[0100] <Cyan two-component developer CD2~CD21> Except for changing the materials shown in Table 8, the production was carried out in the same manner as for the cyan two-component developer CD1, to obtain cyan two-component developers CD2 to CD21.

[0101] <Production example of magenta two-component developer MD1> 8.0 parts of magenta toner MT1 was added to 92.0 parts of magnetic carrier 1, and mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain magenta two-component developer MD1.

[0102] <Magenta two-component developers MD2 to MD14> Except for changing the materials shown in Table 9, magenta two-component developers MD2 to MD14 were produced in the same manner as magenta two-component developer MD1.

[0103] <Production example of yellow two-component developer YD1> 8.0 parts of yellow toner YT1 was added to 92.0 parts of magnetic carrier 1, and mixed in a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain yellow two-component developer YD1.

[0104] <Yellow two-component developers YD2 to YD14> Except for changing the materials shown in Table 10, the same production method as for yellow two-component developer YD1 was used to obtain yellow two-component developers YD2 to YD14.

[0105] The evaluation method for images obtained using the above toner is described below. <Evaluation method for image density (toner coloring power)> The electrophotographic image forming apparatus used was a modified full-color copier (product name: image RUNNER ADVANCE C5255) manufactured by Canon Inc. The evaluation was carried out by loading the two-component developer to be evaluated into each of the cyan, magenta, or yellow developing devices according to the toner to be evaluated. The evaluation environment was a normal temperature and humidity environment (23°C / 50%RH), and the evaluation paper was plain copy paper (product name: GFC-081, A4 size paper, basis weight: 81.4 g / m 2 , sold by Canon Marketing Japan Inc.) was used, and an unfixed toner image (toner loading amount 0.45 mg / cm 2 The unfixed image was fixed using a fixing unit removed from a commercially available full-color digital copier (Image RUNNER ADVANCE C5255, manufactured by Canon). The image density of the resulting fixed image was measured using an X-Rite color reflection densitometer (500 series, manufactured by X-Rite). The image density at this time was evaluated according to the following criteria. (Evaluation criteria for cyan toner) A: 1.80 or higher B: 1.70 or more and less than 1.80 C: 1.60 or more and less than 1.70 D: Less than 1.60 (Evaluation criteria for magenta toner) A: 1.60 or higher B: 1.50 or more and less than 1.60 C: 1.40 or more and less than 1.50 D: Less than 1.40 (Evaluation criteria for yellow toner) A: 1.80 or higher B: 1.70 or more and less than 1.80 C: 1.60 or more and less than 1.70 D: Less than 1.60 The evaluation results are shown in Tables 8 to 10.

[0106] <Method for evaluating concentration stability> A modified full-color copier (product name: image RUNNER ADVANCE C5255) manufactured by Canon Inc. was used as the electrophotographic image forming apparatus. The two-component developer to be evaluated was placed in each of the cyan, magenta, or yellow developing units according to the toner to be evaluated, and the evaluation was carried out. The evaluation environment was 20°C / 8% RH. The evaluation paper was plain copy paper (product name: GFC-081, A4 size paper, basis weight: 81.4 g / m 2 (sold by Canon Marketing Japan Inc.) was used. The amount of toner applied to the paper was changed to form a 16-level image (initial image). The L of the obtained image was measured using a Spectro Scan Transmission (manufactured by Gretag Macbeth) (measurement conditions: D50, viewing angle 2°). * , a * , b * The measurement was carried out by L * -c * C in the coordinate axis * = 85 L1 at toner loading * , a1 * and b1 * were measured respectively.

[0107] Next, the amount of toner applied when the image density of the FFH image (solid area) became 1.45 was calculated, and the developing bias was adjusted. After adjusting the developing bias, a fixed amount of toner was replenished so that the toner density was constant for an image with a print ratio of 1%, and 50,000 sheets (50k) of images were output. After the completion of the image output of 50,000 sheets, the amount of toner on the paper was changed to form a 16-level image. The L of the obtained image was measured using a Spectro Scan Transmission (manufactured by Gretag Macbeth) (measurement conditions: D50, viewing angle 2°). * , a * , b * The measurement was carried out by L * -c * C in the coordinate axis * = 85 L2 at the toner loading amount * , a2 * and b2 * Measure the L of the initial image and the image after 20,000 images were output. * , a * and b * The evaluation results are shown in Tables 8 to 10. ΔE={(L1 * -L2 * ) 2 +(a1 * -a2 * ) 2 +(b1 * -b2 * ) 2} 1 / 2 A: ΔE is less than 2.0 B: ΔE is 2.0 or more and less than 3.5 C: ΔE is 3.5 or more and less than 5.0 D: ΔE is 5.0 or more

[0108] [Table 8]

[0109] [Table 9]

[0110] Table 10

Claims

1. A toner having toner particles containing an organic pigment and a binder resin, In a solid-state NMR measurement at 60°C using the solid content extracted in the following (Procedure 1) as a sample, The transverse relaxation time T2 of the peak observed at 1.5 ppm to 2.5 ppm is 0.08 ms or more and 0.13 ms or less, The binder resin contains a polyester resin A and a polyester resin B, The weight average molecular weight of the polyester resin A is 3,000 to 50,000, The weight average molecular weight of the polyester resin B is 500,000 to 2,300,000, The toner is characterized in that the organic pigment is bonded to the polyester resin B. (Step 1) Add 160 g of sucrose to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a sucrose concentrate. 31 g of the sucrose concentrate and 6 mL of surfactant are placed in a centrifuge tube to prepare a dispersion. 2.0 g of toner is added to this dispersion, and any clumps of toner are broken up with a spatula. The centrifuge tube is then shaken in a shaker. After shaking, the solution is centrifuged at 3500 rpm for 30 minutes with a rotation radius of 3 cm to remove the precipitate. The floating solids are filtered using a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids is dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes at a rotation radius of 3 cm. The supernatant is discarded. 20 mL of chloroform is added, and the same procedure is repeated twice. The precipitated solids are dried in a dryer for at least 5 hours to obtain the sample.

2. 2. The toner according to claim 1, wherein the solid content extracted in step 1 has a resin content of 3.0 parts by mass or more and 50.0 parts by mass or less per 100 parts by mass of the organic pigment.

3. The number average particle diameter of the organic pigment when the solid content extracted in step 1 is observed with a scanning electron microscope is defined as DA, The solid content is stirred with a stirring device, dispersed in water with an impact disperser, and the dispersion is observed with a dynamic light scattering particle size distribution meter, where DB is the number average particle diameter of the organic pigment, 3. The toner according to claim 1, wherein DA / DB is 2.2 or more.

4. The polyester resin A and the polyester resin B have the same monomer unit. The toner according to any one of claims 1 to 3.

5. 5. The toner according to claim 1, wherein the polyester resin A and the polyester resin B are condensation polymers of monomers containing an alkylene oxide adduct of bisphenol A, terephthalic acid, and trimellitic acid or its anhydride.

6. the polyester resin A and the polyester resin B are amorphous polyester resins, the toner particles further contain a crystalline polyester resin, 6. The toner according to claim 1, wherein the content of the crystalline polyester resin in the toner particles is 1.0% by mass or more and 10.0% by mass or less.

7. the toner contains the toner particles and an external additive; the external additive contains strontium titanate particles, 7. The toner according to claim 1, wherein the content of the strontium titanate particles in the toner is 0.1 part by mass or more and 1.0 part by mass or less with respect to 100 parts by mass of the toner particles.

8. the toner particles contain calcium carbonate particles, 8. The toner according to claim 1, wherein the content of the calcium carbonate particles in the toner particles is 3.0% by mass or more and 15.0% by mass or less.

9. When the toner is subjected to X-ray diffraction measurement using CuKα rays, peaks are present in the ranges of diffraction angle (2θ)=26.5°±0.1° and diffraction angle (2θ)=29.5°±0.1°, the crystallite size of the calcium carbonate calculated from a peak in a range of a diffraction angle (2θ) of 29.5°±0.1° is 10 nm or more and 45 nm or less; 9. The toner according to claim 8, wherein the ratio of the peak intensity in the range of a diffraction angle (2θ) of 26.5°±0.1° to the peak intensity in the range of a diffraction angle (2θ) of 29.5°±0.1° is 0.15 or more and 0.24 or less.

10. A method for producing a toner, comprising: the toner has toner particles containing an organic pigment and a binder resin; In a solid-state NMR measurement at 60°C using the solid content extracted in the following (Procedure 1) as a sample, The transverse relaxation time T2 of the peak observed at 1.5 ppm to 2.5 ppm is 0.08 ms or more and 0.13 ms or less, The binder resin contains a polyester resin A and a polyester resin B, The weight average molecular weight of the polyester resin A is 3,000 to 50,000, The weight average molecular weight of the polyester resin B is 500,000 to 2,300,000, The manufacturing method comprises: a first kneading step of melting and kneading a portion of the binder resin and the organic pigment to obtain a pigment mixture; and a second kneading step of melt-kneading the pigment mixture and the remainder of the binder resin to obtain a resin composition; In the first kneading step, the total content of the polyester resin A and the polyester resin B in the pigment mixture is 20% by mass to 50% by mass, the content of the organic pigment in the pigment mixture is 20% by mass to 60% by mass, In the second kneading step, the total content of the polyester resin A and the polyester resin B in the resin composition is 50% by mass to 80% by mass, The method for producing a toner is characterized in that the content of the organic pigment in the resin composition is 3% by mass to 20% by mass. (Step 1) Add 160 g of sucrose to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a sucrose concentrate. 31 g of the sucrose concentrate and 6 mL of surfactant are placed in a centrifuge tube to prepare a dispersion. 2.0 g of toner is added to this dispersion, and any clumps of toner are broken up with a spatula. The centrifuge tube is then shaken in a shaker. After shaking, the solution is centrifuged at 3500 rpm for 30 minutes with a rotation radius of 3 cm to remove the precipitate. The floating solids are filtered using a vacuum filter and then dried in a dryer for at least 1 hour. 1 g of the resulting solids is dissolved in 20 mL of chloroform and centrifuged at 15,000 rpm for 180 minutes at a rotation radius of 3 cm. The supernatant is discarded. 20 mL of chloroform is added, and the same procedure is repeated twice. The precipitated solids are dried in a dryer for at least 5 hours to obtain the sample.

11. 11. The method for producing a toner according to claim 10, wherein a content of the polyester resin B in the pigment mixture is 5% by mass to 30% by mass.

Images