Method for manufacturing toner for electrostatic charge image development

Abstract

To provide a method for manufacturing a toner for electrostatic charge image development which has good low temperature fixability even in high speed printing.SOLUTION: A method for manufacturing a toner for electrostatic charge image development includes the following steps (1) to (3): a step (1) of mixing a release agent with dispersion liquid of resin particles containing 90 mass% or more of a polyester-based resin (A) containing a silicone-modified polyester resin, emulsifying the mixture, and obtaining dispersion liquid of release agent particles; a step (2) of mixing the dispersion liquid of the release agent particles obtained in the step (1) with the dispersion liquid of the polyester-based resin (B) as a binder resin, aggregating the mixture, and obtaining aggregated particles; a step (3) of fusing the aggregated particles obtained in the step (2), and obtaining fused particles, wherein a mass ratio (release agent / polyester-based resin (A)) of the release agent to the polyester-based resin (A) in the step (1) is 1 or more and 100 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a toner for developing electrostatic images used in developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, etc., and to a release agent dispersion liquid that can be used in the production method. [Background technology]

[0002] In the field of electrophotography, with the advancement of electrophotographic systems, there is a demand for the development of electrophotographic toners that can meet the demands for higher image quality and higher speeds. In order to meet the demands for higher image quality, a method for obtaining toners with narrow particle size distribution and small particle sizes has been adopted, in which so-called chemical toners are produced by aggregating and fusing fine resin particles or the like in an aqueous medium (also called an emulsion aggregation method or an aggregation-coalescence method).

[0003] Patent Document 1 describes a method for producing a toner for developing electrostatic images, which includes the steps of mixing and emulsifying a release agent with an aqueous dispersion of resin particles (A) that contain a polyester resin (X) containing a component derived from a hydrocarbon wax having a hydroxyl group or a carboxyl group and has a volume average particle size (DV) of 0.01 μm or more and 1.0 μm or less to obtain an aqueous dispersion of release agent particles, mixing the aqueous dispersion of release agent particles with an aqueous dispersion of resin particles (B) to aggregate them to obtain aggregated particles, and fusing the aggregated particles to obtain fused particles. Patent Document 2 describes a method for producing an aqueous dispersion of release agent particles, which includes a step of obtaining an aqueous dispersion of release agent particles by mixing a release agent with an aqueous dispersion of resin particles (A) containing 90 mass % or more of a composite resin having segments (a1) made of a polyester resin and vinyl resin segments (a2) containing structural units derived from a styrene compound, wherein the mass ratio of the release agent to the resin particles (A) [release agent / resin particles (A)] is 100 / 1 to 100 / 100. Patent Document 3 describes a method for producing a toner for developing electrostatic images, which includes the steps of: mixing and emulsifying a release agent with a dispersion of resin particles (A) containing 90% by mass or more of a polyester containing an aliphatic carboxylic acid-derived component in the acid component, and having a volume median particle size of 0.02 μm or more and 0.05 μm or less, to obtain a dispersion of release agent particles; mixing and aggregating the dispersion of release agent particles with a dispersion of resin particles (B) containing 90% by mass or more of polyester in the resin, to obtain aggregated particles; and fusing the aggregated particles to obtain fused particles, wherein the content of a surfactant in the dispersion of release agent particles is 0.5 parts by mass or less per 100 parts by mass of the release agent. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-44986 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-199759 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-45840 Summary of the Invention [Problem to be solved by the invention]

[0005] In the toner manufacturing method described in Patent Document 1, a polyester resin containing a hydrocarbon wax-derived component is used to prepare a dispersion of release agent particles. However, the difference between the surface tension of the release agent and that of the hydrocarbon wax-derived component is small, resulting in an insufficient coverage of the release agent by the polyester resin-containing resin particles. This leaves room for improvement in low-temperature fixability, particularly in high-speed printing. Furthermore, in the toner using the release agent particles manufactured by the manufacturing method described in Patent Document 2, resin particles containing a composite resin having a vinyl resin segment are used to prepare an aqueous dispersion of release agent particles. However, the surface tension of the vinyl resin segment is higher than that of the release agent, resulting in an insufficient coverage of the release agent by the composite resin-containing resin particles. This leaves room for improvement in low-temperature fixability, particularly in high-speed printing. Furthermore, in the toner manufacturing method described in Patent Document 3, polyester-containing resin particles are used to prepare a dispersion of release agent particles. However, the surface tension of the polyester is higher than that of the release agent, resulting in an insufficient coverage of the release agent by the composite resin-containing resin particles. This leaves room for improvement in low-temperature fixability, particularly in high-speed printing. The present invention relates to a method for producing a toner for developing electrostatic images, which has good low-temperature fixability even in high-speed printing. [Means for solving the problem]

[0006] The present inventors have discovered that when dispersing a release agent in an aqueous medium, by using resin particles containing 90% by mass or more of a polyester resin (A) containing a silicone-modified polyester resin, a dispersion of the release agent (B) can be prepared without using a dispersant such as a surfactant, and that a toner produced by a chemical method in which these release agent particles and the polyester resin (B) as a binder resin are aggregated and fused in an aqueous medium has good low-temperature fixability even in high-speed printing. The present invention relates to the following [1] and [2]. [1] A method for producing a toner for developing electrostatic images, comprising the following steps (1) to (3): Step (1): A step of mixing a release agent with a dispersion of resin particles containing 90% by mass or more of a polyester resin (A) and emulsifying the mixture to obtain a dispersion of release agent particles. Step (2): A step of mixing the dispersion of the release agent particles obtained in step (1) with a dispersion of a polyester resin (B) as a binder resin, and aggregating the mixture to obtain aggregated particles. Step (3): A step of fusing the aggregated particles obtained in step (2) to obtain fused particles. In the step (1), the mass ratio of the release agent to the polyester resin (A) (release agent / polyester resin (A)) is 1 or more and 100 or less, The polyester resin (A) contains a silicone-modified polyester resin. A method for producing a toner for developing electrostatic images. [2] A release agent dispersion containing a release agent dispersed in a silicone-modified polyester resin. [Effects of the Invention]

[0007] According to the present invention, there is provided a method for producing a toner for developing electrostatic images which has good low-temperature fixability even in high-speed printing. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Method of manufacturing electrostatic image developing toner] The method for producing the toner for developing electrostatic images (hereinafter also simply referred to as "toner") of the present invention includes the steps of: step (1) of mixing a release agent with a dispersion of resin particles containing 90% by mass or more of a polyester-based resin (A) (hereinafter also simply referred to as "resin (A)") and emulsifying the mixture to obtain a dispersion of release agent particles; step (2) of mixing the dispersion of release agent particles obtained in step (1) with a dispersion of a polyester-based resin (B) (hereinafter also simply referred to as "resin (B)") as a binder resin, aggregating the mixture to obtain aggregated particles; and step (3) of fusing the aggregated particles obtained in step (2) to obtain fused particles. In the step (1), the mass ratio of the release agent to the polyester resin (A) (release agent / polyester resin (A)) is from 1 to 100. The polyester resin (A) contains a silicone-modified polyester resin. By the above-described manufacturing method, a toner having good low-temperature fixability can be obtained even in high-speed printing.

[0009] Although the detailed mechanism by which the production method of the present invention can provide a toner having good low-temperature fixability even in high-speed printing is not clear, it is thought to be as follows. When a toner is produced by a chemical method, if a surfactant is used to disperse the release agent in an aqueous medium, the surfactant's high dispersing power makes it difficult for the release agent to be encapsulated in the toner. Even if the release agent is encapsulated, it tends to be exposed on the surface of the toner particles. To prevent this, it is desirable to disperse the release agent in the medium without using surfactants as much as possible. In the present invention, in step (1), the release agent is dispersed on the surface of the release agent using resin particles containing 90% by mass or more of a polyester-based resin (A) containing a silicone-modified polyester resin. The silicone moiety of the silicone-modified polyester resin contained in the polyester-based resin (A) has high affinity with the release agent, and the silicone moiety has low surface tension, so it easily spreads over the release agent surface. This increases the coverage of the release agent with the polyester-based resin (A), resulting in highly stable release agent particles. As a result, aggregation of release agent particles is suppressed during toner production. Furthermore, aggregation of release agent particles is suppressed even when the release agent particle dispersion is stored for a long period of time. Furthermore, because polyester moieties are present on the surface of the release agent particles, they have a high affinity with the binder resin during the aggregation and fusion processes in steps (2) and (3), and the release agent particles are well dispersed in the toner particles. As a result, the release effect is manifested at a lower temperature during the fixing process in high-speed printing, which is thought to result in good low-temperature fixing properties even at high speeds. Furthermore, in the release agent dispersion containing the release agent dispersed in the silicone-modified polyester resin of the present invention, the release agent is dispersed by being coated with the silicone-modified polyester resin at a high coverage rate. As a result, it is presumed that by using the release agent dispersion of the present invention in a toner production method, it becomes possible to produce a toner that has excellent low-temperature fixability even in high-speed printing, due to the same mechanism as described above. The above-mentioned mechanism regarding the effects of the present invention is only a supposition, and the present invention is not limited to this.

[0010] The definitions of various terms used in this specification are shown below. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself but also anhydrides that decompose during the reaction to produce carboxylic acids, and alkyl esters of each carboxylic acid (alkyl groups having 1 to 3 carbon atoms). Whether a resin is crystalline or amorphous is determined by its crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the endothermic maximum peak temperature (softening point (°C) / endothermic maximum peak temperature (°C)) measured by the method described in the Examples below. A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or, if an endothermic peak is observed, one with a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be adjusted appropriately by adjusting the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate.

[0011] A method for producing a toner according to one embodiment of the present invention includes the steps of: Step (1): A step of mixing a release agent with a dispersion of resin particles containing 90% by mass or more of a polyester resin (A) and emulsifying the mixture to obtain a dispersion of release agent particles. Step (2): A step of mixing the dispersion of the release agent particles obtained in step (1) with a dispersion of a polyester resin (B) as a binder resin, and aggregating the mixture to obtain aggregated particles. Step (3): A step of fusing the aggregated particles obtained in step (2) to obtain fused particles. Includes. The present invention will be described below by taking this embodiment as an example.

[0012] [Process (1)] In step (1), a release agent is mixed with a dispersion of resin particles containing 90% by mass or more of a polyester resin (A) and emulsified to obtain a dispersion of release agent particles. The dispersion of resin particles containing resin (A) is preferably an aqueous dispersion. By preparing release agent particles using a release agent and resin particles containing resin (A), the release agent is stabilized by the resin (A), making it possible to stably disperse the release agent in an aqueous medium without using a surfactant. It is believed that the dispersion of release agent particles has a structure in which many resin particles containing resin (A) are attached to the periphery of the release agent.

[0013] The dispersion of release agent particles can be obtained, for example, by dispersing a dispersion of resin particles containing the release agent and 90% by mass or more of the resin (A) and, if necessary, an aqueous medium at a temperature equal to or higher than the melting point of the release agent using a disperser having a strong shear force, such as a homogenizer, a high-pressure disperser, or an ultrasonic disperser. The heating temperature during dispersion is preferably equal to or higher than the melting point of the release agent and 80°C or higher, more preferably 85°C or higher, and even more preferably 90°C or higher, and is preferably less than a temperature 10°C higher than the softening point of the resin (A) and 100°C or lower, more preferably 98°C or lower, and even more preferably 95°C or lower.

[0014] From the viewpoints of improving the dispersion stability of the release agent particles, improving the long-term stability of the release agent particle dispersion, suppressing detachment and exposure of the release agent, obtaining uniformly aggregated particles in the subsequent aggregation step, containing the release agent in the toner even after heating in the fusion step, and improving low-temperature fixability in high-speed printing, the mass ratio of the release agent to the resin (A) (release agent / resin (A)) is 1 or more, preferably 1.5 or more, more preferably 1.8 or more, and 100 or less, preferably 50 or less, more preferably 20 or less, and even more preferably 10 or less.

[0015] When a surfactant is used in this step, the high dispersing power of the surfactant makes it easier for the release agent to be exposed to the surface of the toner particles. Therefore, it is preferable not to use a surfactant, but when a surfactant is used, the total amount used is preferably less than 0.1 parts by mass, more preferably 0.05 parts by mass or less, and even more preferably 0.01 parts by mass or less, relative to 100 parts by mass of the total amount of the release agent. Examples of such surfactants include those described in paragraph

[0074] of JP 2016-197207 A.

[0016] <Release agent particles> The release agent particles contain a release agent and resin particles containing 90% by mass or more of the resin (A).

[0017] Volume median particle size D of release agent particles 50 From the viewpoint of obtaining uniformly aggregated particles in step (2), the average particle size is preferably 0.01 μm or more, more preferably 0.10 μm or more, even more preferably 0.20 μm or more, and is preferably 3 μm or less, more preferably 1 μm or less, even more preferably 0.50 μm or less. Volume median particle size D of release agent particles 50 The measurement method is the method described in the Examples.

[0018] [Release agent] The release agent may be a wax, such as a hydrocarbon wax, an ester wax, a silicone wax, or a fatty acid amide wax. Examples of hydrocarbon waxes include mineral or petroleum-based hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax; and synthetic hydrocarbon waxes such as polyolefin waxes such as polyethylene wax, polypropylene wax and polybutene wax. Examples of ester waxes include mineral or petroleum-based ester waxes such as montan wax; plant-based ester waxes such as carnauba wax, rice wax, and candelilla wax; and animal-based ester waxes such as beeswax. Examples of fatty acid amide waxes include oleic acid amide and stearic acid amide. Among these, from the viewpoint of toner releasability, preferred are hydrocarbon waxes and ester waxes, more preferred are at least one selected from paraffin wax, Fischer-Tropsch wax, polyolefin wax, and ester wax, even more preferred are at least one selected from paraffin wax and ester wax, and even more preferred is paraffin wax. The release agent may be used alone or in combination of two or more kinds.

[0019] The melting point of the release agent is preferably 60°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher from the viewpoint of the releasability of the toner, and is preferably 100°C or lower, more preferably 95°C or lower from the viewpoint of improving the low-temperature fixability of the toner and widening the fixable temperature range. When two or more release agents are used in combination, it is preferable that all of them have melting points of 60°C or higher and 100°C or lower. That is, when two or more release agents are used in combination, it is preferable to contain at least two release agents having melting points of 60°C or higher and 100°C or lower, and it is more preferable that all of the release agents have melting points of 65°C or higher and 95°C or lower. In the present invention, the melting point of the release agent is determined by the method described in the examples. When two or more release agents are used in combination, the melting point of the release agent with the largest mass ratio among the release agents contained in the resulting toner is taken as the melting point of the release agent in the present invention. When all the release agents have the same mass ratio, the melting point of the release agent with the lowest melting point is taken as the melting point of the release agent in the present invention.

[0020] From the viewpoint of the releasability of the toner, the amount of the release agent used is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, even more preferably 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, in the toner particles.

[0021] [Resin particles] The resin particles contain 90% by mass or more of resin (A). From the viewpoint of improving the dispersibility of the release agent and the affinity between the release agent particles and resin (B), the content of resin (A) is preferably 92% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, and 100% by mass or less, preferably 100% by mass. Components contained in the resin particles other than resin (A) include other resins such as polyester resins. Resin (A) contains a silicone-modified polyester resin, and the content of the silicone-modified polyester resin is, from the same viewpoint as above, preferably 95% by mass or more, more preferably 97% by mass or more, and 100% by mass or less, preferably 100% by mass. Components in resin (A) other than the silicone-modified polyester resin include resin (B) and resin (C) described below.

[0022] [Silicone-modified polyester resin] From the viewpoint of obtaining a stable dispersion of release agent particles in step (1) and improving the dispersion of the release agent particles in the toner particles in the aggregation and fusion processes of steps (2) and (3), the silicone-modified polyester resin is preferably a reaction product of an alcohol component containing a divalent or higher alcohol, a carboxylic acid component containing a divalent or higher carboxylic acid compound, and a modified silicone having at least one functional group selected from a hydroxy group, a carboxy group, and an epoxy group. Furthermore, it is more preferable that resin E be an amorphous resin.

[0023] <Alcohol content> The alcohol component includes dihydric or higher alcohols. The content of dihydric or higher alcohol in the alcohol component is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, and 100% by mass or less. Examples of dihydric or higher alcohols include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols and linear or branched aliphatic diols are preferred.

[0024] The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0025] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each a positive number that indicates the average number of moles of alkylene oxide added, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, and more preferably 4 or less. Examples of alkylene oxide adducts of bisphenol A include propylene oxide adducts of bisphenol A and ethylene oxide adducts of bisphenol A. One or more of these may be used. Among these, a combination of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A is preferred. The molar ratio of the propylene oxide adduct of bisphenol A to the ethylene oxide adduct of bisphenol A (propylene oxide adduct of bisphenol A / ethylene oxide adduct of bisphenol A) is preferably 10 / 90 or more, more preferably 15 / 85 or more, even more preferably 20 / 80 or more, and is preferably 90 / 10 or less, more preferably 70 / 30 or less, even more preferably 50 / 50 or less, even more preferably 35 / 65 or less. When an alkylene oxide adduct of bisphenol A is contained, the amount thereof is preferably 70 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol% in the alcohol component.

[0026] As the linear or branched aliphatic diol, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferred. The aliphatic diol having a hydroxyl group bonded to a secondary carbon atom preferably has 3 or more and 4 or less carbon atoms. Examples of aliphatic diols having a hydroxyl group bonded to a secondary carbon atom include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol. Among these, 1,2-propanediol is preferred. When an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is used as the alcohol component, the amount thereof is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %, in the alcohol component.

[0027] Other linear or branched aliphatic diols include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and neopentyl glycol.

[0028] Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and adducts of hydrogenated bisphenol A with alkylene oxides having 2 to 4 carbon atoms (average number of added moles: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.

[0029] <Carboxylic acid component> The carboxylic acid component includes a divalent or higher carboxylic acid compound. The content of the divalent or higher carboxylic acid compound in the carboxylic acid component is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, and is 100% by mass or less. Examples of divalent or higher carboxylic acid compounds include aromatic dicarboxylic acid compounds, linear or branched aliphatic dicarboxylic acid compounds, alicyclic dicarboxylic acid compounds, and trivalent or higher polycarboxylic acid compounds. Among these, aromatic dicarboxylic acid compounds are preferred.

[0030] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. The amount of the aromatic dicarboxylic acid compound in the carboxylic acid component is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, and preferably 100 mol% or less, more preferably 95 mol% or less, even more preferably 93 mol% or less.

[0031] The carbon number of the linear or branched aliphatic dicarboxylic acid compound is preferably 2 or more, more preferably 4 or more, even more preferably 8 or more, and even more preferably 10 or more, and is preferably 22 or less, more preferably 16 or less. Examples of linear or branched aliphatic dicarboxylic acid compounds include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms, or anhydrides or alkyl esters having from 1 to 3 carbon atoms. Examples of succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, succinic acid substituted with an aliphatic hydrocarbon group having from 1 to 20 carbon atoms, or anhydrides thereof, are preferred. When a linear or branched aliphatic dicarboxylic acid compound is contained, the amount thereof is preferably 2 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, in the carboxylic acid component.

[0032] The trivalent or higher polyvalent carboxylic acid compound is preferably a trivalent carboxylic acid, such as trimellitic acid or its anhydride, of which trimellitic acid or its anhydride is preferred. When a trivalent or higher polycarboxylic acid compound is contained, the amount of the trivalent or higher polycarboxylic acid compound in the carboxylic acid component is preferably 1 mol % or more, more preferably 5 mol % or more, even more preferably 7 mol % or more, and is preferably 35 mol % or less, more preferably 30 mol % or less. These carboxylic acid compounds may be used alone or in combination of two or more.

[0033] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0034] <Modified silicone> The modified silicone used in the silicone-modified polyester resin reacts with at least one of an alcohol component and a carboxylic acid component to obtain a stable dispersion of release agent particles in step (1) and to improve the dispersion of the release agent particles in the toner particles in the aggregation and fusion processes of steps (2) and (3). From this viewpoint, the modified silicone preferably has at least one functional group selected from a hydroxy group, a carboxy group, and an epoxy group at a side chain, one end, or both ends, and more preferably at one end or both ends.

[0035] More specifically, the modified silicone is preferably a compound represented by the formula (1):

[0036] [ka] [In the formula, each R is independently a hydrocarbon group having from 1 to 6 carbon atoms, each R' is independently an alkylene group having from 1 to 10 carbon atoms, each R'' is independently a hydrocarbon group having from 1 to 10 carbon atoms, each X is independently a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group, s is an integer of from 1 to 3, t is an integer of from 0 to 3, and n is an integer of from 5 to 300.]

[0037] The hydrocarbon group of R has 6 or less carbon atoms, preferably 5 or less, more preferably 4 or less, even more preferably 3 or less, still more preferably 2 or less, and still more preferably 1 carbon atom. Examples of hydrocarbon groups for R include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, and phenyl groups. Among these, methyl is preferred. The alkylene group of R' has 10 or less carbon atoms, preferably 8 or less, more preferably 5 or less, even more preferably 4 or less, still more preferably 3 or less carbon atoms, and preferably 1 or more, more preferably 2 or more carbon atoms. Examples of the alkylene group represented by R' include methanediyl, ethane-1,2-diyl, ethane-1,1-diyl, n-propane-1,3-diyl, and n-propane-1,2-diyl. Among these, ethane-1,2-diyl, n-propane-1,3-diyl, and n-propane-1,2-diyl are preferred. The hydrocarbon group of R'' has 10 or less carbon atoms, preferably 8 or less, more preferably 6 or less, even more preferably 4 or less, even more preferably 3 or less, even more preferably 2 or less, and even more preferably 1 carbon atom. Examples of the hydrocarbon group for R'' include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, and a benzyl group. X is a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group. The hydroxyalkyloxy group and the hydroxyalkyloxy group may have multiple hydroxy groups. The carboxyalkyloxy group may have multiple carboxy groups. s is 3 or less, preferably 2 or less, and more preferably 1. t is 3 or less, preferably 2 or less, and more preferably 0 or 1. n is 300 or less, preferably 200 or less, more preferably 100 or less, and even more preferably 50 or less, and is 5 or more, preferably 8 or more, and more preferably 10 or more.

[0038] The weight average molecular weight (Mw) of the modified silicone is preferably 600 or more, more preferably 800 or more, even more preferably 1,000 or more, and preferably 20,000 or less, more preferably 10,000 or less, even more preferably 7,000 or less, even more preferably 6,000 or less, even more preferably 5,000 or less, even more preferably 4,000 or less. The number average molecular weight (Mn) of the modified silicone is preferably 500 or more, more preferably 700 or more, even more preferably 800 or more, and preferably 10,000 or less, more preferably 5,000 or less, even more preferably 4,000 or less, even more preferably 3,000 or less.

[0039] The kinematic viscosity of the modified silicone is preferably 10 mm at 25°C. 2 / s or more, preferably 15 mm 2 / s or more, more preferably 20 mm 2 / s or more, and preferably 500 mm 2 / s or less, preferably 400 mm 2 / s or less, more preferably 300 mm 2 / s or less. The kinematic viscosity of the modified silicone is measured at 25°C using a fully automatic micro kinematic viscometer (manufactured by Viscotec Co., Ltd.).

[0040] The functional group equivalent weight of the modified silicone is preferably 300 g / mol or more, more preferably 500 g / mol or more, even more preferably 700 g / mol or more, and is preferably 5,000 g / mol or less, more preferably 4,000 g / mol or less, even more preferably 3,000 g / mol or less. The functional group equivalent weight means the mass of the modified silicone per mole of the functional group.

[0041] As the modified silicone used in the silicone-modified polyester resin, a modified silicone (a) having a hydroxy group at one or both ends (hereinafter simply referred to as "modified silicone (a)") is preferred, from the viewpoint of obtaining a toner that has excellent low-temperature fixing properties even in high-speed printing. That is, the modified silicone (a) is preferably a compound represented by the formula (1a):

[0042] [ka] [wherein R, R′, R″, s, t, and n are defined as in the above formula (1)]. 1 are each independently a hydroxy group or a hydroxyalkyloxy group. The hydroxyalkyloxy group may have a plurality of hydroxy groups. The number of carbon atoms in the hydroxyalkyl group is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less. R'X 1 Examples of the group represented by the formula include the following substituents 2a-1 to 2a-3. Among these, the substituent 2a-1 or the substituent 2a-2 is preferred, and the substituent 2a-1 is more preferred. * is a bonding site with Si.

[0043] [ka]

[0044] From the viewpoint of further improving low-temperature fixability even in high-speed printing, the modified silicone (a) preferably has one hydroxy group at each end or one at one end, i.e., in the above formula (1a), s and t are 1 or s is 1 and t is 0. Examples of modified silicones (a) include silicones modified with carbinol at both ends (commercially available products include "X-22-160AS," "KF-6000," "KF-6001," "KF-6002," and "KF-6003" (all manufactured by Shin-Etsu Chemical Co., Ltd.)), and silicones modified with carbinol at one end (commercially available products include "X-22-170BX," "X-22-170DX," "X-22-176DX," and "X-22-176GX-A" (all manufactured by Shin-Etsu Chemical Co., Ltd.)).

[0045] As the modified silicone used in the silicone-modified polyester resin, a modified silicone (b) having an epoxy group at one or both ends is also preferred from the viewpoint of obtaining a toner that has excellent low-temperature fixability even in high-speed printing. In other words, the modified silicone (b) is Preferably, the compound of formula (1b):

[0046] [ka] [wherein R, R′, R″, s, t, and n are defined as in the above formula (1)]. 2 are each independently at least one functional group selected from an epoxy group, a glycidyl group, a glycidyloxy group, and an alicyclic epoxy group. R'X 2 Examples of the group represented by the formula include the following substituents 2b-1 to 2b-3. Among these, the substituent 2b-1 is preferred.

[0047] [ka]

[0048] From the viewpoint of further improving low-temperature fixability even in high-speed printing, the modified silicone (b) preferably has one epoxy group at each end or one at one end, i.e., in the above formula (1b), s and t are 1 or s is 1 and t is 0. Examples of modified silicones (b) include silicones modified at both ends with epoxy groups (commercially available products include "KF-105," "X-22-163A," "X-22-163B," "X-22-163C," "X-22-169AS," and "X-22-169B" (all manufactured by Shin-Etsu Chemical Co., Ltd.)), and silicones modified at one end with epoxy groups (commercially available products include "X-22-173BX" and "X-22-173DX" (all manufactured by Shin-Etsu Chemical Co., Ltd.)).

[0049] As the modified silicone used in the silicone-modified polyester resin, a modified silicone (c) having a carboxy group at one or both ends is also preferred from the viewpoint of obtaining a toner that has excellent low-temperature fixability even in high-speed printing. That is, the modified silicone (c) is preferably a compound represented by the formula (1c):

[0050] [ka] [wherein R, R′, R″, s, t, and n are defined as in the above formula (1)]. 3 are each independently a carboxy group or a carboxyalkyloxy group. R'X 3 Examples of the group represented by the formula include the following substituent 2c-1.

[0051] [ka]

[0052] From the viewpoint of further improving low-temperature fixability even in high-speed printing, the modified silicone (c) preferably has one carboxy group at each end or one at one end, i.e., in the above formula (1c), s and t are 1 or s is 1 and t is 0. Examples of modified silicones (c) include silicones modified with carboxyl groups at both ends (commercially available products include "X-22-162C" and "BY16-750" manufactured by Shin-Etsu Chemical Co., Ltd.), and silicones modified with carboxyl groups at one end (commercially available product includes "X-22-3710" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0053] In the raw materials for the silicone-modified polyester resin, the amount of modified silicone relative to the total amount of the alcohol component, carboxylic acid component, and modified silicone is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, from the viewpoint of obtaining a toner that has excellent low-temperature fixability even in high-speed printing, and is preferably 9% by mass or less, more preferably 7% by mass or less, even more preferably 6% by mass or less.

[0054] In the raw materials for the silicone-modified polyester resin, the total amount of the alcohol component and the carboxylic acid component, relative to the total amount of the alcohol component, the carboxylic acid component, and the modified silicone, is preferably 91% by mass or more, more preferably 93% by mass or more, even more preferably 94% by mass or more, and is preferably 99.9% by mass or less, more preferably 99% by mass or less, even more preferably 98% by mass or less, even more preferably 96% by mass or less.

[0055] The above amounts are calculated based on the alcohol component, carboxylic acid component, and modified silicone, and do not take into account the amount of water removed by condensation. When the modified silicone has a hydroxy group or a carboxy group, it can also be understood as an alcohol component or a carboxylic acid component, but when a compound having a hydroxy group or a carboxy group contains a silicone skeleton, it is considered to be a modified silicone. For example, when calculating the total amount of the alcohol component and the carboxylic acid component, the modified silicone having a hydroxy group or a carboxy group is not included in this total amount.

[0056] <Method for producing silicone-modified polyester resin> Silicone-modified polyester resins can be obtained, for example, by reacting an alcohol component, a carboxylic acid component, and a modified silicone. In this reaction, if necessary, an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropylate bistriethanolamine may be used in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the alcohol component and the carboxylic acid component combined, or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) may be used in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the alcohol component and the carboxylic acid component combined. The reaction temperature is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and is preferably 250°C or lower, more preferably 240°C or lower. The reaction may be carried out in an inert gas atmosphere.

[0057] <Physical properties of silicone-modified polyester resin> From the viewpoint of obtaining a toner having good low-temperature fixability even in high-speed printing, the number average molecular weight of the silicone-modified polyester resin is preferably 800 or more, more preferably 1,500 or more, even more preferably 2,500 or more, and is preferably 30,000 or less, more preferably 20,000 or less, even more preferably 10,000 or less, even more preferably 5,000 or less, even more preferably 4,000 or less.

[0058] The acid value of the silicone-modified polyester resin is preferably 1 mgKOH / g or more, more preferably 5 mgKOH / g or more, even more preferably 10 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 20 mgKOH / g or less.

[0059] From the viewpoint of obtaining a toner having good low-temperature fixing properties even in high-speed printing, the softening point of the silicone-modified polyester resin is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and even more preferably 105°C or higher, and is preferably 140°C or lower, more preferably 130°C or lower, even more preferably 120°C or lower, and even more preferably 115°C or lower.

[0060] From the viewpoint of obtaining a toner for developing electrostatic images that has good low-temperature fixability even in high-speed printing, the glass transition temperature of the silicone-modified polyester resin is preferably 45°C or higher, more preferably 50°C or higher, even more preferably 55°C or higher, and is preferably 80°C or lower, more preferably 75°C or lower, even more preferably 70°C or lower.

[0061] The number average molecular weight, acid value, softening point, and glass transition temperature of the silicone-modified polyester resin can be adjusted appropriately by adjusting the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the methods described in the examples. When two or more silicone-modified polyester resins are used in combination, it is preferable that the number average molecular weight, acid value, hydroxyl value, softening point, and glass transition temperature of the resulting mixture each fall within the aforementioned ranges.

[0062] [Method for producing dispersion of resin particles containing polyester resin (A)] The resin particles containing the resin (A) may be produced as an aqueous dispersion of the resin particles. The aqueous medium used for the aqueous dispersion is preferably one containing water as the main component.

[0063] Dispersion can be carried out using known methods, but is preferably carried out by a phase inversion emulsification method. Examples of phase inversion emulsification methods include a method in which an aqueous medium is added to an organic solvent solution of resin (A) or molten resin (A) to effect phase inversion emulsification. A preferred method is a method in which an aqueous medium is added to an organic solvent solution of resin (A) to effect phase inversion emulsification. For example, an aqueous dispersion of resin particles containing resin (A) can be produced by adding an aqueous medium to an organic solvent solution of resin (A) to effect phase inversion emulsification. The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin (A) and is water-soluble, and examples thereof include methyl ethyl ketone. After dissolving the resin (A) in an organic solvent, it is preferable to neutralize the resin E before adding the aqueous solvent. Examples of neutralizing agents include basic substances. Examples of basic substances include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred. The degree of neutralization of the resin contained in the resin particles is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and is preferably 100 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less. The degree of neutralization of the resin contained in the resin particles can be determined by the following formula. Degree of neutralization (mol %)=[{weight (g) of neutralizing agent added / equivalent weight of neutralizing agent} / [{weighted average acid value (mg KOH / g) of resin constituting resin particles × weight (g) of resin constituting resin particles} / (56 × 1000)]] × 100

[0064] While stirring the organic solvent solution or the molten resin, the aqueous medium is gradually added to cause phase inversion. From the viewpoint of improving the dispersion stability of the resin particles, the temperature of the organic solvent solution when the aqueous medium is added is preferably equal to or higher than the glass transition temperature of the resin having the highest glass transition temperature among the resins contained in the resin particles, more preferably equal to or higher than 60°C, even more preferably equal to or higher than 65°C, even more preferably equal to or higher than 70°C, and is preferably equal to or lower than 100°C, more preferably equal to or lower than 90°C, even more preferably equal to or lower than 80°C.

[0065] After the phase inversion emulsification, the organic solvent may be removed from the resulting dispersion by distillation or the like, if necessary. Alternatively, the resin particles may be isolated by filtration or the like. In the aggregation and fusion steps of the present invention, it is preferable to use an aqueous dispersion of resin particles obtained by removing the organic solvent from the dispersion obtained after the phase inversion emulsification. In this case, the amount of the remaining organic solvent in the dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass.

[0066] Volume median particle size D of resin particles in dispersion 50 From the viewpoint of improving the dispersion stability of the dispersion liquid of the release agent particles, the average particle size is preferably 0.05 μm or more, more preferably 0.08 μm or more, and is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less.

[0067] From the viewpoint of improving the dispersion stability of the dispersion of the release agent particles, the solid content concentration of the aqueous dispersion of the resin particles is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 25% by mass or less. The solid content is the total amount of non-volatile components.

[0068] [Process (2)] In step (2), the dispersion of the release agent particles obtained in step (1) is mixed with a dispersion of the polyester resin (B) as a binder resin and aggregated to obtain aggregated particles. In step (2), a dispersion of colorant particles and other additives may be added before aggregation and aggregated together with the release agent particles and the polyester resin (B). The amount of the release agent particles relative to 100 parts by mass of the total amount of resin (B) used in step (2) is preferably 4 parts by mass or more, more preferably 8 parts by mass or more, even more preferably 12 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, from the viewpoint of further stabilizing the dispersibility of the release agent and obtaining a toner that has excellent low-temperature fixability even in high-speed printing.

[0069] <Polyester resin (B)> In step (2), the polyester resin (B) as the binder resin may contain an amorphous polyester resin (B1) (hereinafter also simply referred to as "resin (B1)"). The polyester resin (B) is preferably resin (B1) from the viewpoint of obtaining a toner that satisfactorily encapsulates release agent particles in the toner and has excellent low-temperature fixability even in high-speed printing.

[0070] [Amorphous polyester resin (B1)] The amorphous polyester resin (B1) contains an amorphous polyester resin or an amorphous polyester segment which is a polycondensation product of an alcohol component containing a diol compound and a carboxylic acid component containing a dicarboxylic acid compound. Examples of amorphous polyester resins include polyester resins and modified polyester resins. Examples of modified polyester resins include urethane-modified polyester resins, epoxy-modified polyester resins, and composite resins containing polyester resin segments and addition-polymerized resin segments. Among these, polyester resins and composite resins are preferred, and polyester resins are more preferred.

[0071] Examples of the alcohol component include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols are preferred from the viewpoint of having high affinity with the release agent particles. The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0072] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each a positive number that indicates the average number of moles of alkylene oxide added, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, and more preferably 4 or less. Examples of alkylene oxide adducts of bisphenol A include a propylene oxide adduct of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination of two or more. Among these, a combination of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A is preferred. The amount of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0073] Examples of linear or branched aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol. Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and adducts of hydrogenated bisphenol A with alkylene oxides having 2 to 4 carbon atoms (average number of added moles: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.

[0074] Examples of the carboxylic acid component include dicarboxylic acids and trivalent or higher polycarboxylic acids. Examples of dicarboxylic acids include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred. Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. The amount of aromatic dicarboxylic acid in the carboxylic acid component is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less.

[0075] The linear or branched aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably 30 or less, more preferably 20 or less carbon atoms. Examples of linear or branched aliphatic dicarboxylic acids include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acid substituted with a hydrocarbon group having from 1 to 20 carbon atoms. Examples of succinic acid substituted with a hydrocarbon group having from 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, adipic acid and succinic acid substituted with an alkyl or alkenyl group are preferred. The amount of the linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably 1 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, even more preferably 25 mol% or more, and is preferably 50 mol% or less, more preferably 45 mol% or less, even more preferably 40 mol% or less.

[0076] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, such as trimellitic acid or its anhydride. When a trivalent or higher polycarboxylic acid is contained, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, and is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 15 mol% or less. These carboxylic acid components may be used alone or in combination of two or more.

[0077] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0078] <Method for producing resin (B1)> The resin (B1) may be produced, for example, by a method including a step of carrying out a polycondensation reaction between an alcohol component and a carboxylic acid component. In the step of carrying out the polycondensation reaction, if necessary, polycondensation may be carried out using an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropoxybis(triethanolaminate) in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; or an esterification promoter such as gallic acid (equivalent to 3,4,5-trihydroxybenzoic acid) in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. When a monomer having an unsaturated bond such as fumaric acid is used in the polycondensation reaction, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and is preferably 260°C or lower, more preferably 250°C or lower.

[0079] <Physical properties of resin (B1)> The softening point of the resin (B1) is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 140°C or lower, more preferably 130°C or lower, even more preferably 125°C or lower. The glass transition temperature of the resin (B1) is preferably 30°C or higher, more preferably 40°C or higher, even more preferably 50°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, even more preferably 60°C or lower.

[0080] The acid value of the resin (B1) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, even more preferably 15 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 25 mgKOH / g or less. The softening point, glass transition temperature, and acid value of the resin (B1) can be appropriately adjusted by the types and amounts of raw material monomers used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the methods described in the examples. When two or more resins (B1) are used in combination, the softening point, glass transition temperature and acid value of the resulting mixture are preferably within the above-mentioned ranges.

[0081] In the present invention, the binder resin preferably further contains a resin (C) from the viewpoint of obtaining a toner having excellent low-temperature fixability even in high-speed printing. The resin (C) is preferably a crystalline polyester resin (C1) (hereinafter also referred to as "resin (C1)").

[0082] [Crystalline polyester resin (C1)] The resin (C1) is, for example, a polycondensate of an alcohol component and a carboxylic acid component. The alcohol component preferably comprises an α,ω-aliphatic diol. The α,ω-aliphatic diol preferably has 2 or more carbon atoms, and preferably 16 or less, more preferably 14 or less, and even more preferably 12 or less carbon atoms. Examples of α,ω-aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol. Among these, ethylene glycol is preferred.

[0083] The amount of the α,ω-aliphatic diol in the alcohol component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0084] The alcohol component may contain other alcohol components different from the α,ω-aliphatic diol. Examples of other alcohol components include aliphatic diols other than α,ω-aliphatic diols, such as 1,2-propylene glycol and neopentyl glycol; aromatic diols, such as alkylene oxide adducts of bisphenol A; and trihydric or higher alcohols, such as glycerin, pentaerythritol, and trimethylolpropane. These alcohol components may be used alone or in combination.

[0085] The carboxylic acid component preferably comprises an aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid preferably has 4 or more carbon atoms, more preferably 6 or more carbon atoms, and preferably has 18 or less carbon atoms, more preferably 16 or less carbon atoms. Examples of aliphatic dicarboxylic acids include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid, dodecanedioic acid, and tetradecanedioic acid are preferred, and tetradecanedioic acid is more preferred. These carboxylic acid components may be used alone or in combination.

[0086] The amount of the aliphatic dicarboxylic acid in the carboxylic acid component is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and is 100 mol% or less, even more preferably 100 mol%.

[0087] The carboxylic acid component may contain other carboxylic acid components different from the aliphatic dicarboxylic acid. Examples of other carboxylic acid components include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and polycarboxylic acids having three or more carboxylic acids. These carboxylic acid components may be used alone or in combination of two or more.

[0088] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0089] <Method for producing resin (C1)> Resin (C1) can be obtained, for example, by polycondensation of an alcohol component and a carboxylic acid component. The polycondensation conditions can be the same as those for the polycondensation of resin (B1) described above.

[0090] <Physical properties of resin (C1)> The softening point of the resin (C1) is preferably 60°C or higher, more preferably 70°C or higher, even more preferably 80°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, even more preferably 110°C or lower. The melting point of the resin (C1) is preferably 60°C or higher, more preferably 70°C or higher, even more preferably 75°C or higher, and preferably 110°C or lower, more preferably 100°C or lower, even more preferably 95°C or lower.

[0091] The acid value of the resin (C1) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 25 mgKOH / g or less.

[0092] The softening point, melting point, and acid value of the resin (C1) can be adjusted appropriately by adjusting the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate. These values ​​are determined by the methods described in the Examples below. When two or more resins (C1) are used in combination, it is preferable that the softening point, melting point, and acid value of the resulting mixture are within the aforementioned ranges.

[0093] The mass ratio of resin (C) to resin (B) (resin (C) / resin (B)) is preferably 1 / 99 or more, more preferably 3 / 97 or more, even more preferably 5 / 95 or more, and is preferably 50 / 50 or less, more preferably 40 / 60 or less, even more preferably 30 / 70 or less.

[0094] In the resin components of the toner, the total content of resin (B) and resin (C) is preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less, preferably 98% by mass or less.

[0095] [Method for producing binder resin particles] When the binder resin contains resin (B) and resin (C), the binder resin contains resin (B) and resin (C) in the same or different resin particles. Here, in the following explanation, resin particles X containing resin (B) within the particles will be explained. The aqueous medium is preferably one containing water as a main component. From the viewpoint of improving the dispersion stability of the binder resin particle dispersion and from the viewpoint of environmental friendliness, the water content in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, even more preferably 100% by mass. Deionized water or distilled water is preferred as the water. Examples of components other than water that may be contained in the aqueous medium include water-soluble organic solvents such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having a total carbon number of 3 to 5, such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran. Among these, methyl ethyl ketone is preferred.

[0096] The dispersion can be carried out by a known method, but is preferably carried out by a phase inversion emulsification method, such as a method in which an aqueous medium is added to an organic solvent solution of a resin or a molten resin to carry out phase inversion emulsification.

[0097] The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin, and examples thereof include methyl ethyl ketone. It is preferable to add a neutralizing agent to the organic solvent solution of the resin. Examples of the neutralizing agent include basic substances. Examples of the basic substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. The degree of neutralization of the resin contained in the resin particles X is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and is preferably 100 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less. The degree of neutralization of the resin contained in the resin particles can be determined by the following formula. Degree of neutralization (mol %)=[{weight (g) of neutralizing agent added / equivalent weight of neutralizing agent} / [{weighted average acid value (mg KOH / g) of resin constituting resin particle X × weight (g) of resin constituting resin particle X} / (56 × 1000)]] × 100

[0098] Phase inversion emulsification is carried out by gradually adding an aqueous medium to a solution of the resin in an organic solvent or a molten resin while stirring the solution. From the viewpoint of improving the dispersion stability of the resin particles X, the temperature of the organic solvent solution when the aqueous medium is added is preferably equal to or higher than the glass transition temperature of the amorphous resin (B) constituting the resin particles X, more preferably equal to or higher than 50°C, even more preferably equal to or higher than 60°C, even more preferably equal to or higher than 70°C, and is preferably equal to or lower than 100°C, more preferably equal to or lower than 90°C, even more preferably equal to or lower than 80°C. In addition, when producing resin particles Y, the temperature of the organic solvent solution when adding the aqueous medium is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 70°C or higher, from the viewpoint of improving dispersion stability, and is preferably 100°C or lower, more preferably 90°C or lower, even more preferably 80°C or lower.

[0099] After the phase inversion emulsification, if necessary, the organic solvent may be removed from the obtained dispersion by distillation, etc. In this case, the amount of the remaining organic solvent in the dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass.

[0100] Volume median particle size D of resin particles X in the dispersion 50 From the viewpoint of obtaining a toner that can produce high-quality images, the particle size is preferably 0.05 μm or more, more preferably 0.08 μm or more, and is preferably 1 μm or less, more preferably 0.5 μm or less, and even more preferably 0.3 μm or less. From the viewpoint of obtaining a toner that can produce high-quality images, the CV value of the resin particles X in the dispersion is preferably 10% or more, more preferably 20% or more, and is preferably 40% or less, more preferably 30% or less. Volume median particle size D 50 The CV value can be determined by the method described in the Examples below. Both the resin particles Y containing the resin (C) and the resin particles XY containing the resins (B) and (C) can be produced in accordance with the above-mentioned method. 50 The preferred range of the CV value is the same as the range described above.

[0101] <Colorant particles> [Coloring Agent] The colorant is preferably mixed with resin particles as a dispersion of colorant particles, and then aggregated to be contained in the aggregated particles. As the colorant, any dye, pigment, etc. that is used as a colorant for toner can be used. Examples of colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, disazo yellow, etc. The toner may be either black toner or a color toner other than black.

[0102] [Method for producing colorant particle dispersion] The colorant particles are preferably mixed with resin particles to form a dispersion of colorant particles, followed by aggregating the colorant particles, and are incorporated into the aggregated particles, and are preferably obtained by dispersing the colorant and aqueous medium using a disperser such as a homogenizer or an ultrasonic disperser. From the viewpoint of improving the dispersion stability of the colorant, the dispersion is preferably carried out in the presence of an addition polymer (hereinafter, the addition polymer used to disperse the colorant is also referred to as "addition polymer E") or a surfactant, and more preferably in the presence of an addition polymer. Examples of the surfactant include a nonionic surfactant, an anionic surfactant, and a cationic surfactant. The addition polymer E preferably has a constituent unit derived from an addition polymerizable monomer a having an aromatic group, and preferably further contains at least one selected from the group consisting of an addition polymerizable monomer b having an ionic group, an addition polymerizable monomer c having a polyalkylene oxide group, and a macromonomer d. For details of the colorant particle dispersion and the addition polymer E, reference is made to the addition polymer E described in JP 2021-026129 A.

[0103] [Surfactant] In step (2), when the dispersions of the respective particles are mixed to prepare a mixed dispersion, the process may be carried out in the presence of a surfactant in order to improve the dispersion stability of the resin particles containing the resin (B), the release agent particles, the colorant particles, etc. Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. When a surfactant is used, the total amount used is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, even more preferably 0.5 parts by mass or more, per 100 parts by mass of the total amount of resin particles including resin (B), and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less.

[0104] The dispersion of resin particles containing the resin (B), the dispersion of release agent particles, the dispersion of colorant particles, and any optional components are mixed by a conventional method. From the viewpoint of efficiently performing aggregation, it is preferable to add an aggregating agent to the mixed dispersion obtained by the mixing.

[0105] [Flocculant] Examples of the flocculant include cationic surfactants such as quaternary salts, organic flocculants such as polyethyleneimine, and inorganic flocculants. Examples of the inorganic flocculant include inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and divalent or higher metal complexes. From the viewpoint of improving the coagulation properties and obtaining uniformly coagulated particles, inorganic coagulants having a valence of 1 to 5 are preferred, inorganic metal salts having a valence of 1 to 2 and inorganic ammonium salts are more preferred, inorganic ammonium salts are even more preferred, and ammonium sulfate is even more preferred.

[0106] For example, a flocculant is added to a mixed dispersion containing resin particles containing resin (B), release agent particles, and colorant particles at a temperature of 0° C. to 40° C. in an amount of 5 parts by mass to 50 parts by mass per 100 parts by mass of the total amount of resin, and the resin particles containing resin (B), release agent particles, and colorant particles are aggregated in an aqueous medium to obtain aggregated particles. Furthermore, from the viewpoint of promoting aggregation, it is preferable to increase the temperature of the dispersion after adding the flocculant.

[0107] The aggregation may be stopped when the aggregated particles grow to a suitable particle size for toner particles. Methods for stopping aggregation include a method of cooling the dispersion, a method of adding an aggregation terminator, a method of diluting the dispersion, etc. From the viewpoint of reliably preventing unnecessary aggregation, a method of stopping aggregation by adding an aggregation terminator is preferred.

[0108] [Aggregation Stopper] The aggregation terminator is preferably a surfactant, more preferably an anionic surfactant. Examples of anionic surfactants include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, and polyoxyalkylene alkyl ether sulfates. These may be used alone or in combination. The aggregation terminator may be added in the form of an aqueous solution. The amount of the aggregation terminator added is preferably 1 part by mass or more, more preferably 5 parts by mass or more, per 100 parts by mass of the resin in the resin particles containing resin (B), from the viewpoint of reliably preventing unnecessary aggregation, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, from the viewpoint of reducing residue in the toner.

[0109] Volume median particle size of agglomerated particles D 50is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less.

[0110] In the present invention, after step (2) and before step (3), a step (step (2')) may be included in which shell resin particles containing an amorphous resin (preferably an amorphous polyester resin) are attached to the aggregated particles (aggregated particles 1) obtained in step (2) to obtain aggregated particles 2. By including step (2'), toner particles having a core-shell structure can be obtained. Here, examples of the amorphous resin used for the shell resin particles include the polyester resin (B) described above. The shell resin particles can be obtained by the same method as for the resin particles containing the resin (B) described above. Furthermore, when the toner manufacturing method includes step (2'), it is preferable to terminate the aggregation of aggregated particles 2 in step (2') when they have grown to a particle size appropriate for toner particles, and a method of terminating the aggregation by adding the above-mentioned aggregation terminator is preferred.

[0111] [Process (3)] In step (3), for example, the aggregated particles are fused in an aqueous medium. By fusion, the particles contained in the aggregated particles are fused together to obtain fused particles. In step (3), from the viewpoint of improving the fusion property of the aggregated particles, the aggregated particles are maintained at a temperature equal to or higher than the glass transition temperature of the resin having the highest glass transition temperature among the resins contained in the aggregated particles. The holding temperature when fusing the aggregated particles is, from the viewpoint of improving the fusing properties of the aggregated particles and improving the productivity of the toner, preferably at least 5°C higher than the glass transition temperature of the resin, more preferably at least 10°C higher, and even more preferably at least 15°C higher, and is preferably not higher than 40°C higher, more preferably not higher than 30°C higher, and even more preferably not higher than 25°C higher than the glass transition temperature of the resin. In this case, the time for maintaining the temperature at or above the glass transition temperature of the resin is preferably 1 minute or more, more preferably 10 minutes or more, even more preferably 30 minutes or more, and preferably 240 minutes or less, more preferably 180 minutes or less, even more preferably 120 minutes or less, even more preferably 90 minutes or less. It is preferable to maintain the temperature at the above temperature until the desired circularity is achieved.

[0112] The volume median particle size D of the fused particles obtained by fusion 50 is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 7 μm or less.

[0113] The circularity of the fused particles obtained by fusion is preferably 0.955 or more, more preferably 0.960 or more, and is preferably 0.990 or less, more preferably 0.985 or less, and even more preferably 0.980 or less. The fusion is preferably terminated after the desired circularity is reached. The circularity is measured by the method described in the Examples.

[0114] <Post-processing process> A post-treatment step may be carried out after step (3), and toner particles are obtained by isolating the fused particles. Since the fused particles obtained in step (3) are present in an aqueous medium, it is preferable to first carry out solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used. It is preferable to wash the solid-liquid separation product. At this time, it is preferable to remove the added surfactant, so washing with an aqueous medium at a temperature below the cloud point of the surfactant is preferable. Washing is preferably performed multiple times. Next, it is preferable to carry out drying. Examples of drying methods include vacuum low-temperature drying, vibration fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0115] [Toner particles] Volume median particle size D of toner particles 50 From the viewpoint of obtaining high-quality images and further improving the cleaning properties of the toner, the particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 7 μm or less.

[0116] The CV value of the toner particles is preferably 12% or more, more preferably 16% or more, and even more preferably 20% or more from the viewpoint of improving toner productivity, and is preferably 35% or less, more preferably 30% or less from the viewpoint of obtaining high-quality images. Volume median particle size D of toner particles 50 The CV value can be measured by the method described in the Examples.

[0117] [Electrostatic image developing toner] The toner for developing electrostatic images (hereinafter also simply referred to as toner) of the present invention contains toner particles. Although the toner particles can be used as they are, it is preferable to use the toner after adding a fluidizing agent or the like as an external additive to the surface of the toner particles.

[0118] <External additives> Examples of external additives include fine particles of inorganic materials such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and fine particles of polymers such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. One type of external additive may be used alone, or two or more types may be used. Two or more types of hydrophobic silica having different particle sizes may also be used. When the surface treatment of the toner particles is performed using an external additive, the amount of the external additive added is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, even more preferably 4 parts by mass or less, relative to 100 parts by mass of the toner particles.

[0119] Toners are used to develop electrostatic images in electrophotographic printing. Toners can be used, for example, as a one-component developer or as a two-component developer mixed with a carrier.

[0120] [Release agent dispersion] The release agent dispersion according to one embodiment of the present invention contains a release agent dispersed in a silicone-modified polyester resin. From the viewpoint of storage stability, the release agent dispersion is preferably an aqueous dispersion. The release agent contained in the release agent dispersion liquid can be any of the release agents listed above for the release agent particles. The silicone-modified polyester resin in which the release agent is dispersed can be any of the silicone-modified polyester resins listed above as the resin (A) contained in the resin particles.

[0121] The method for producing the release agent dispersion may be the same as the step (1) in the toner production method.

[0122] From the viewpoint of improving the dispersion stability of the release agent dispersion, the mass ratio of the release agent to the silicone-modified polyester resin (release agent / silicone-modified polyester resin) is preferably 1 or more, more preferably 1.5 or more, even more preferably 1.8 or more, and is preferably 100 or less, more preferably 50 or less, even more preferably 20 or less, even more preferably 10 or less. Volume median particle size D of particles made of release agent dispersed in silicone-modified polyester resin 50 is preferably 0.01 μm or more, more preferably 0.10 μm or more, even more preferably 0.20 μm or more, and is preferably 3 μm or less, more preferably 1 μm or less, even more preferably 0.50 μm or less. [Example]

[0123] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Each property value was measured and evaluated by the following methods. In the notation "alkylene oxide (X)" and the like, the number X in parentheses means the average number of moles of alkylene oxide added.

[0124] [Measurement method] <Acid value of resin> The acid value of the resin was measured according to the neutralization titration method described in JIS K 0070:1992, except that the measurement solvent was chloroform. <Resin softening point, crystallinity index, melting point and glass transition temperature> (1) Softening point Using a flow tester "CFT-500D" (Shimadzu Corporation), 1 g of sample was heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa was applied by the plunger, and the sample was extruded from a nozzle 1 mm in diameter and 1 mm in length. The plunger depression distance of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point. (2) Crystallinity index Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The sample was then left to stand for 1 minute, and then heated to 180°C at a rate of 10°C / min, and the calorific value was measured. The temperature of the peak with the largest peak area among the observed endothermic peaks was defined as the endothermic maximum peak temperature (1), and the crystallinity index was calculated by (softening point (°C)) / (endothermic maximum peak temperature (1) (°C)). (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled from that temperature to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the calorific value was measured. Of the endothermic peaks observed, the temperature of the peak with the largest peak area was taken as the maximum endothermic peak temperature (2). For crystalline resins, this peak temperature was taken as the melting point. In the case of an amorphous resin, when a peak is observed, the temperature of the peak is taken as the glass transition temperature. When a step is observed instead of a peak, the temperature at the intersection of the tangent line showing the maximum slope of the curve at the step and an extension of the baseline on the low-temperature side of the step is taken as the glass transition temperature.

[0125] <Melting point of release agent> Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, the calorific value was measured, and the maximum endothermic peak temperature was taken as the melting point.

[0126] <Volume median particle size D of resin particles, colorant particles, and release agent particles 50 and CV value> (1) Measuring device: Laser diffraction particle size measuring instrument "LA-920" (manufactured by Horiba Ltd.) (2) Measurement conditions: Put the sample dispersion in a measurement cell, add distilled water, and measure the volume median particle size D at a concentration where the absorbance is in the appropriate range. 50 and volume average particle size D v The CV value was calculated according to the following formula: CV value (%) = (standard deviation of particle size distribution) / volume average particle size D v ) x 100

[0127] <Solid Content Concentration of Resin Particle Dispersion, Colorant Particle Dispersion, and Release Agent Particle Dispersion> Using an infrared moisture meter "FD-230" (Kett Electric Laboratory Co., Ltd.), the moisture content (mass%) of 5 g of the measurement sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, moisture content fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0128] <Moisture content of toner particles> Using an infrared moisture meter "FD-230" (manufactured by Kett Electric Laboratory Co., Ltd.), the moisture content (mass%) of 5 g of toner particles was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, moisture content fluctuation range 0.05%).

[0129] <Volume median particle size of agglomerated particles D 50 > Volume median particle size of agglomerated particles D 50 was measured as follows: Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (Beckman Coulter, Inc.) Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured again, and the volume median particle size D is calculated from the particle size distribution. 50 asked for.

[0130] <Circularity of fused particles> The circularity of the fused particles was measured under the following conditions. Measurement equipment: Flow particle image analyzer "FPIA-3000" (Sysmex Corporation) Preparation of dispersion: The dispersion of fused particles was diluted with deionized water to a solids concentration of 0.001 to 0.05% by mass. Measurement mode: HPF measurement mode

[0131] <Volume median particle size D of toner particles 50 and CV value> Volume median particle size D of toner particles 50 was measured as follows: The measurement device, aperture diameter, analysis software, and electrolyte were determined based on the volume median particle diameter D 50 The same material as that used in the measurement was used. Dispersion: Polyoxyethylene lauryl ether "EMULGEN (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) was dissolved in the electrolyte solution to obtain a dispersion with a concentration of 5 mass %. Dispersion conditions: 10 mg of a measurement sample of dried toner particles was added to 5 mL of the dispersion liquid, and the mixture was dispersed for 1 minute using an ultrasonic disperser. Thereafter, 25 mL of the electrolyte solution was added, and the mixture was further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion liquid. Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, 30,000 particles are measured, and the volume median particle size D is calculated from the particle size distribution. 50 and volume average particle size D V asked for. The CV value (%) was calculated according to the following formula: CV value (%) = (standard deviation of particle size distribution) / volume average particle size D V ) x 100

[0132] [Evaluation method] <Storage stability of dispersion of release agent particles> 100 g of the dispersion of release agent particles was placed in a 250 g plastic container, and the container was kept sealed at 40°C for two months, after which the particle size of the release agent particles was compared with the particle size before storage. The storage stability of the dispersion of release agent particles is expressed as the ratio of the particle size of the release agent particles after storage at 40°C for 2 months to the particle size of the release agent particles before storage (particle size of release agent particles after storage at 40°C for 2 months / particle size of release agent particles before storage), and the closer the number is to 1, the better the storage stability of the dispersion of release agent particles. The particle size of the release agent particles is measured according to the above-mentioned <Volume Median Particle Size D of Resin Particles, Colorant Particles, and Release Agent Particles>. 50 and CV values ​​are as shown.

[0133] <Low temperature fixability under high speed conditions> Using a commercially available printer "Microline (registered trademark) 5400" (manufactured by OKI Data Corporation) on high-quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), the amount of toner adhered to the paper was 0.45±0.01mg / cm 2 The solid image was printed without fixing, leaving a 5mm margin from the top edge of an A4 sheet of paper, and a length of 50mm. Next, the same printer was prepared with a modified temperature-variable fixing unit, and the temperature of the fixing unit was set to 100°C. The toner was fixed onto an A4 sheet in portrait orientation at a speed of 0.8 seconds per sheet, resulting in a printed product. In the same manner, the temperature of the fixing device was increased by 5° C. each time, and the toner was fixed to obtain a printed matter. A 50 mm length of Scotch (registered trademark) Mending Tape 810 (manufactured by Sumitomo 3M Limited, width 18 mm) was lightly applied from the top margin of the printed image to the solid image, and then a 500 g weight (contact area 1963 mm) was applied. 2 ) was placed on the print and pressed back and forth at a speed of 10 mm / s. The applied tape was then peeled off from the bottom edge at a peeling angle of 180° and a speed of 10 mm / s to obtain a print after tape removal. Thirty sheets of high-quality paper "Excellent White Paper, A4 size" (manufactured by OKI Data Corporation) were placed under the print before and after tape removal. The reflection image density of the fixed image portion of each print before and after tape removal was measured using a "SpectroEye" colorimeter (manufactured by GretagMacbeth, lighting conditions: standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard). The fixation rate was calculated from each reflection image density according to the following formula: Fixation rate (%) = (reflected image density after tape peeling / reflected image density before tape application) x 100 The lowest temperature at which the fixing rate is 90% or more is defined as the minimum fixing temperature T1. The lower the minimum fixing temperature, the better the low-temperature fixing ability.

[0134] [Resin manufacturing] <Production of Polyester Resin (A)> Production Example A1 (Production of Resin A-1) A 10 L four-neck flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 1380 g of propylene oxide (2.2) adduct of bisphenol A, 4059 g of ethylene oxide (2.2) adduct of bisphenol A, 2182 g of terephthalic acid, 374 g of silicone "X-22-170BX" (Shin-Etsu Chemical Co., Ltd.), and 40 g of tin(II) di(2-ethylhexanoate) were added. The mixture was heated to 235°C under nitrogen atmosphere with stirring. After maintaining this temperature for 6 hours, the pressure in the flask was reduced and the temperature was maintained at 8 kPa for 1 hour. After returning to atmospheric pressure, the mixture was cooled to 210°C, 379 g of trimellitic anhydride was added, and the mixture was reacted for 1 hour. The pressure in the flask was then reduced and the reaction was continued at 8 kPa until the desired softening point was reached, yielding Resin A-1. The physical properties are shown in Table 1.

[0135] Manufacturing Examples A2 to A4 and Manufacturing Examples A81 to A82 (Resins A-2 to A-4 and Resins A-81 to A-82) Resins A-2 to A-4 and A-81 to A-82 were obtained in the same manner as in Production Example A1, except that the raw material compositions were changed as shown in Table 1. Table 1 shows the physical properties.

[0136] Manufacturing Example A5 (Manufacturing of Resin A-5) A 10 L four-neck flask equipped with a nitrogen inlet, a dehydration tube fitted with a fractionating column containing 98°C hot water, a stirrer, and a thermocouple was purged with nitrogen. 2712 g of 1,2-propanediol, 4740 g of terephthalic acid, 374 g of silicone "X-22-170BX" (Shin-Etsu Chemical Co., Ltd.), and 40 g of tin(II) di(2-ethylhexanoate) were added. The mixture was stirred under a nitrogen atmosphere at 180°C for 1 hour, then heated from 180°C to 230°C at a rate of 10°C / hr. Polycondensation was then carried out at 230°C for 5 hours. The mixture was then cooled to 210°C, 548 g of trimellitic anhydride was added, and the mixture was reacted for 1 hour. The pressure in the flask was then reduced, and the reaction was continued at 8 kPa until the desired softening point was reached, yielding Resin A-5. The physical properties are shown in Table 1.

[0137] In Table 1, the various silicones used have the following compositions. X-22-170BX: Modified silicone oil "X-22-170BX" (a silicone having a carbinol group at one end [the aforementioned modified silicone (a) (in formula (1a) R and R" are methyl groups, and R'X 1 is a group represented by formula (2a-1), s = 1, t = 0)], kinematic viscosity (25°C) 40 mm 2 / s, number average molecular weight Mn 1,900, weight average molecular weight Mw 3,500, functional group equivalent 2,800 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd. KF-6001: Modified silicone oil "KF-6001" (a silicone having carbinol groups at both ends [the above-mentioned modified silicone (a) (in formula (1a), R and R" are methyl groups, and R'X 1 is a group represented by formula (2a-1), s = 1, t = 1)], kinematic viscosity (25°C) 45 mm 2 / s, number average molecular weight Mn 1,800, weight average molecular weight Mw 2,700, functional group equivalent 900 g / mol, manufactured by Shin-Etsu Chemical Co., Ltd. KF96-100cs: Unmodified silicone oil "KF96-100cs" (silicone oil, kinematic viscosity (25°C) 100mm 2 / s, manufactured by Shin-Etsu Chemical Co., Ltd.) The kinematic viscosity and functional group equivalent weight of the modified and unmodified silicones were determined from the catalog values ​​of each product.

[0138] [Table 1]

[0139] <Production of amorphous polyester resin (B1)> Production Example B1 (Production of Resin B1-1) A four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 3880 g of propylene oxide (2.2) adduct of 2,2-bis(4-hydroxyphenyl)propane, 1544 g of ethylene oxide (2.2) adduct of 2,2-bis(4-hydroxyphenyl)propane, 1578 g of terephthalic acid, 694 g of adipic acid, and 40 g of tin (II) di(2-ethylhexanoate) were added under a nitrogen atmosphere with stirring. The mixture was heated to 235 ° C. and maintained at 235 ° C. for 6 hours, after which the pressure in the flask was further reduced and maintained at 8.3 kPa for 1 hour. The mixture was then cooled to 215 ° C. and returned to atmospheric pressure. 304 g of trimellitic anhydride was added, and the mixture was maintained at 215 ° C. for 1 hour. The pressure in the flask was further reduced and the reaction proceeded to the desired softening point at 8.3 kPa to obtain Resin B1-1. The physical properties of the resulting resin are shown in Table 2.

[0140] Production Example B2 (Production of Resin B1-2) A four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 3558 g of propylene oxide (2.2) adduct of 2,2-bis(4-hydroxyphenyl)propane, 1416 g of ethylene oxide (2.2) adduct of 2,2-bis(4-hydroxyphenyl)propane, 1229 g of terephthalic acid, 1518 g of dodecenylsuccinic anhydride, and 40 g of tin (II) di(2-ethylhexanoate) were added. The mixture was stirred under a nitrogen atmosphere and heated to 230 ° C., maintained at 230 ° C. for 6 hours, then the pressure in the flask was reduced and maintained at 8.3 kPa for 1 hour. The mixture was then cooled to 215 ° C. and returned to atmospheric pressure. 279 g of trimellitic anhydride was added, maintained at 215 ° C. for 1 hour, and then the pressure in the flask was reduced and maintained at 8.3 kPa for 3 hours to obtain Resin B1-2. The physical properties are shown in Table 2.

[0141] [Table 2]

[0142] <Production of Crystalline Polyester Resin (C1)> Production Example C1 (Production of Resin C1-1) A 10 L four-neck flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 1453 g of ethylene glycol and 6047 g of tetradecanedioic acid were added and heated to 135°C with stirring. The mixture was then held at 135°C for 3 hours, and then heated from 135°C to 200°C over 10 hours. 15 g of tin(II) di(2-ethylhexanoate) was then added and the mixture was held at 200°C for another hour. The pressure inside the flask was then reduced and the mixture was held under a reduced pressure of 8 kPa for 1 hour, yielding Resin C1-1. The physical properties are shown in Table 3.

[0143] [Table 3]

[0144] <Production of Addition Polymer E> Production Example E1 (Production of Addition Polymer E-1) The types and amounts of raw material monomers shown in Table 4 were mixed to prepare a monomer mixture having a total monomer amount of 100 g. The inside of a four-neck flask equipped with a nitrogen inlet tube, dropping funnel, stirrer, and thermocouple was replaced with nitrogen. 18 g of methyl ethyl ketone, 0.03 g of 2-mercaptoethanol, and 10% by mass of the monomer mixture were added and heated to 75°C with stirring. While maintaining the temperature at 75°C, a mixture of the remaining 90% by mass of the monomer mixture, 0.27 g of 2-mercaptoethanol, 42 g of methyl ethyl ketone, and 3 g of 2,2'-azobis(2,4-dimethylvaleronitrile) "V-65" (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise from the dropping funnel over 3 hours. After the addition was completed, the temperature was maintained at 75°C for 2 hours. A solution of 3 g of V-65 in 5 g of methyl ethyl ketone was added, and the mixture was further maintained at 75°C for 2 hours and then at 80°C for 2 hours. The methyl ethyl ketone was then distilled off under reduced pressure to obtain addition polymer E-1. The weight average molecular weight of the resulting addition polymer E-1 is shown in Table 4.

[0145] [Table 4]

[0146] [Production of resin particle dispersion] Production Example X1 (Production of Resin Particle Dispersion X-1) 300 g of Resin B1-1, 360 g of methyl ethyl ketone, and 59 g of deionized water were placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of the resin was 60 mol%, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while stirring at 280 r / min (circumferential speed 63 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion X-1. The volume median particle diameter D of the resulting resin particles was 50 and CV values ​​are shown in Table 5.

[0147] Production Example X2 (Production of Resin Particle Dispersion X-2) Resin particle dispersion X-2 was obtained in the same manner as in Production Example X1, except that the type of resin used was changed as shown in Table 5. The volume median particle diameter D of the obtained resin particles 50 and CV values ​​are shown in Table 5.

[0148] Production Example Y1 (Production of Resin Particle Dispersion Y-1) A mixed solvent of 300 g of resin C1-1, 300 g of methyl ethyl ketone, and 41 g of deionized water was placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of the resin was 55 mol%, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while continuing to stir at 280 r / min (circumferential speed 88 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion Y-1. The volume median particle diameter D of the resulting resin particles was 50 and CV values ​​are shown in Table 5.

[0149] [Table 5]

[0150] Production Example Z1 (Production of Resin Particle Dispersion Z-1) A mixed solvent of 300 g of Resin A-1, 300 g of methyl ethyl ketone, and 41 g of deionized water was placed in a 3 L vessel equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and the resin was dissolved over 2 hours at 73° C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization was 55 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 600 g of deionized water was added over 60 minutes while stirring at 280 r / min (circumferential speed 88 m / min), resulting in phase inversion emulsification. While continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, while continuing to stir at 280 r / min (circumferential speed 88 m / min), the aqueous dispersion was cooled to 30°C, and deionized water was added to obtain a solids concentration of 20 mass%, thereby obtaining resin particle dispersion Z-1. The volume median particle diameter D of the resulting resin particles was 50 and CV values ​​are shown in Table 6.

[0151] Production Examples Z2 to Z5 and Production Examples Z81 to Z82 (Production of Resin Particle Dispersions Z-2 to Z-5 and Resin Particle Dispersions Z-81 to Z-82) Resin particle dispersions Z-2 to Z-5 and resin particle dispersions Z-81 to Z-82 were obtained in the same manner as in Production Example Z1, except that the type of resin used was changed as shown in Table 6. The volume median particle diameter D 50 and CV values ​​are shown in Table 6.

[0152] [Table 6]

[0153] <Production of Colorant Particle Dispersion> Production Example V1 (Production of Colorant Particle Dispersion V-1) A 5L vessel equipped with a stirrer equipped with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube was charged with 75g of addition polymer E-1 and 630g of methyl ethyl ketone, and the resin was dissolved at 20°C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of addition polymer E-1 was 91 mol%, and 955g of deionized water was then added. The mixture was stirred with a disperser blade at 20°C for 10 minutes to effect phase inversion emulsification. Next, 300g of Pigment Yellow 155 (Clariant Chemicals, "Toner Yellow 3GP-CT", molecular weight 717) was added, and the mixture was stirred with a disperser blade at 6400 r / min for 2 hours at 20°C. The mixture was then passed through a 200-mesh filter and subjected to 15 passes at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (Microfluidics). The resulting dispersion was stirred at 70°C under reduced pressure to remove methyl ethyl ketone and a portion of the water. After cooling, the mixture was passed through a 200-mesh filter, and deionized water was added to adjust the solid content to 20% by mass, to obtain colorant particle dispersion V-1. The volume median particle diameter D of the resulting colorant particles was 50 The particle size was 0.10 μm and the CV value was 28%.

[0154] <Production of Release Agent Particle Dispersion (Step (1))> Production Example W1 (Production of Release Agent Particle Dispersion W-1) 120 g of deionized water, 80 g of resin particle dispersion Z-1, and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) were added to a 1 L beaker, and the mixture was melted by maintaining the temperature at 90-95°C and stirred to obtain a molten mixture. The obtained molten mixture was further dispersed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while maintaining the temperature at 90 to 95°C, and then cooled to room temperature (20°C). Deionized water was added to adjust the solid content to 20% by mass, thereby obtaining a release agent particle dispersion W-1. The volume median particle diameter D of the release agent particles in the obtained dispersion was 50 The CV value and storage stability are shown in Table 7.

[0155] Production Examples W2 to W8 and Production Examples W81 to W82 (Production of Release Agent Particle Dispersions W-2 to W-8 and Release Agent Particle Dispersions W-81 to W-82) Release agent particle dispersions W-2 to W-8 and release agent particle dispersions W-81 to W-82 were prepared in the same manner as in Production Example W1, except that the types of resin particle dispersions and release agents used were changed as shown in Table 7. The volume median particle diameter D 50 The CV values ​​and storage stability are shown in Table 7.

[0156] Production Example W83 (Production of Release Agent Particle Dispersion W-83) A 1-L beaker was charged with deionized water (120 g) and 167 g of 15% by weight sodium dodecylbenzenesulfonate aqueous solution "Neopelex G-15" (anionic surfactant, manufactured by Kao Corporation) was dissolved therein. Then, 100 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75°C) was added. The mixture was melted and stirred while maintaining the temperature at 90-95°C to obtain a molten mixture. While maintaining the temperature at 90-95°C, the mixture was dispersed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) and then cooled to room temperature. Deionized water was added to the resulting dispersion to adjust the solids concentration to 20% by weight, yielding release agent particle dispersion W-83. The physical properties are shown in Table 7.

[0157] [Table 7]

[0158] [Toner Production (Steps (2) and (3))] Example 1 (Production of Toner 1) In a 3 L four-neck flask equipped with a dehydration tube, a stirrer, and a thermocouple, 450 g of resin particle dispersion X-1, 50 g of resin particle dispersion Y-1, 80 g of release agent particle dispersion W-1, 81 g of colorant particle dispersion V-1, 5 g of a 10 mass% aqueous solution of polyoxyethylene (50) lauryl ether "EMULGEN 150" (Kao Corporation, nonionic surfactant), and 2 g of a 15 mass% aqueous solution of sodium dodecylbenzenesulfonate "NEOPELEX G-15" (Kao Corporation, anionic surfactant) were mixed at 25°C. Next, while stirring the mixture, a solution prepared by dissolving 43 g of ammonium sulfate in 580 g of deionized water and adding 4.8 mass% aqueous potassium hydroxide to adjust the pH to 8.4 was added dropwise over 10 minutes at 25°C, and the mixture was then heated to 60°C over 2 hours to measure the volume median particle diameter D of the aggregated particles. 50 The temperature was maintained at 60°C until the particle size reached 5.5 µm, thereby obtaining a dispersion of aggregated particles. To the resulting dispersion of aggregated particles, an aqueous solution containing 48 g of sodium polyoxyethylene lauryl ether sulfate "EMAL E-27C" (Kao Corporation, anionic surfactant, effective concentration 27% by mass), 500 g of deionized water, and 60 g of 0.1 mol / L aqueous sulfuric acid solution was added. The temperature was then raised to 83°C over 1 hour and maintained at 83°C for 30 minutes. After that, 10 g of 0.1 mol / L aqueous sulfuric acid solution was added, and the mixture was further maintained at 83°C for 15 minutes. Thereafter, 10 g of 0.1 mol / L aqueous sulfuric acid solution was added again, and the mixture was maintained at 83°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles in which the aggregated particles were fused. The resulting fused particle dispersion was cooled to 30°C, and the dispersion was suction filtered to separate the solids. The solids were then washed with deionized water at 25°C and suction filtered at 25°C for 2 hours. The solids were then vacuum dried at 33°C for 24 hours using a vacuum constant temperature dryer "DRV622DA" (manufactured by ADVANTEC Corporation), yielding toner particles with a moisture content of 0.5% by mass or less. The physical properties of the resulting toner particles are shown in Table 8. 100 parts by mass of toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 0.04 μm), and 1.0 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., number average particle size: 0.012 μm) were placed in a Henschel mixer, stirred, and passed through a 150 mesh sieve to obtain Toner 1. The evaluation results of the obtained toner are shown in Table 8.

[0159] Examples 2 to 9 and Comparative Examples 1 to 3 (Production of Toners 2 to 9 and Toners 81 to 83) Toners 2 to 9 and toners 81 to 83 were produced in the same manner as in Example 1, except that the types of resin particle dispersions and colorant particle dispersions used were changed as shown in Table 8. The physical properties of the obtained toner particles and the evaluation results of the toners are shown in Table 8.

[0160] [Table 8]

[0161] As shown in Table 8, the results of the Examples and Comparative Examples demonstrate that the toner for developing electrostatic images obtained by the production method of the present invention has good low-temperature fixability even in high-speed printing. On the other hand, the toner obtained by the manufacturing method of Comparative Example 1, which used a release agent particle dispersion liquid in which a release agent was dispersed using polyester resin A-81 instead of resin (A) containing a silicone-modified polyester resin, the toner obtained by the manufacturing method of Comparative Example 2, which used a release agent particle dispersion liquid in which a release agent was dispersed using a mixture A-82 of a polyester resin and silicone oil, and the toner obtained by the manufacturing method of Comparative Example 3, which used a release agent particle dispersion liquid in which a release agent was dispersed using an anionic surfactant, all had poor low-temperature fixability when printing at high speeds.

Claims

1. A method for producing a toner for developing electrostatic images, comprising the following steps (1) to (3): Step (1): A step of mixing a release agent with a dispersion of resin particles containing 90% by mass or more of a polyester-based resin (A) and emulsifying the mixture to obtain a dispersion of release agent particles. Step (2): A step of mixing the dispersion of the release agent particles obtained in step (1) with a dispersion of the polyester resin (B) as a binder resin, and aggregating the mixture to obtain aggregated particles. Step (3): A step of fusing the aggregated particles obtained in step (2) to obtain fused particles. In the step (1), the mass ratio of the release agent to the polyester resin (A) (release agent / polyester resin (A)) is 1 or more and 100 or less, The polyester resin (A) contains a silicone-modified polyester resin. A method for producing a toner for developing electrostatic images.

2. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the silicone-modified polyester resin is a reaction product of an alcohol component containing a divalent or higher alcohol, a carboxylic acid component containing a divalent or higher carboxylic acid compound, and a modified silicone having at least one functional group selected from a hydroxy group, a carboxy group, and an epoxy group.

3. The method for producing a toner for developing electrostatic images according to claim 2 , wherein the modified silicone comprises a modified silicone represented by formula (1): 【Chemistry 1】 (In the formula, each R is independently a hydrocarbon group having from 1 to 6 carbon atoms; each R' is independently an alkylene group having from 1 to 10 carbon atoms; each R'' is independently a hydrocarbon group having from 1 to 10 carbon atoms; each X is independently a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group; s is an integer of from 1 to 3; t is an integer of from 0 to 3; and n is an integer of from 5 to 300.)

4. 3. The method for producing a toner for developing electrostatic images according to claim 2, wherein the modified silicone has a hydroxy group at one or both ends.

5. 3. The method for producing a toner for developing electrostatic images according to claim 2, wherein the content of the modified silicone is 0.1% by mass or more and 9% by mass or less with respect to the total amount of the alcohol component, the carboxylic acid component, and the modified silicone.

6. The method for producing a toner for developing electrostatic images according to claim 1 , wherein the polyester resin (B) comprises an amorphous polyester resin (B1).

7. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the amount of the surfactant used in step (1) is less than 0.1 parts by mass per 100 parts by mass of the total amount of the release agent.

8. The volume median particle size D of the release agent particles ５０ 8. The method for producing a toner for developing electrostatic images according to claim 1, wherein the particle size is 0.01 μm or more and 3 μm or less.

9. A release agent dispersion comprising a release agent dispersed in a silicone modified polyester resin.

10. 10. The release agent dispersion according to claim 9, wherein a mass ratio of the release agent to the silicone-modified polyester resin (release agent / silicone-modified polyester resin) is 1 or more and 100 or less.

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