Method for manufacturing toner for electrostatic image development

Abstract

To provide a method for manufacturing a toner for electrostatic charge image development which is excellent in low temperature fixability, and has narrow charge amount distribution.SOLUTION: A method for manufacturing a toner for electrostatic charge image development includes a step of aggregating and fusing resin particles containing an amorphous resin and a crystalline resin in the same or different particles in an aqueous medium, wherein the amorphous resin contains an amorphous polyester resin (A) which is a polycondensation product of an alcohol component (a) containing aliphatic diol having 2 to 5 carbon atoms and a carboxylic acid component (b), and the crystalline resin contains a crystalline polyester resin (C) which is a polycondensation product of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In the field of electrophotography, the development of electrophotographic systems has created a demand for the development of electrophotographic toners that can handle higher speeds and higher image quality. To meet the demands of higher speeds, toners need to have rapid thermal response, and it has been found that conventional toners have insufficient low-temperature fixing properties. Furthermore, as speeds increase, the time it takes for toner to transfer to paper also decreases, so toners with excellent electrostatic properties are required.

[0003] Patent Document 1 describes a toner comprising an amorphous polyester resin and a crystalline polyester resin binder resin and a release agent, wherein the amorphous polyester resin is an amorphous polyester resin obtained by polycondensation of a dicarboxylic acid monomer mainly composed of terephthalic acid or isophthalic acid and a diol monomer mainly composed of ethylene glycol, the crystalline polyester resin is a crystalline polyester resin obtained by polycondensation of a dicarboxylic acid monomer mainly composed of an aliphatic dicarboxylic acid having 9 to 22 carbon atoms and a diol monomer mainly composed of an aliphatic diol having 2 to 10 carbon atoms, and the release agent is a synthetic ester wax with a hydroxyl value of less than 5 mgKOH / g, and it is stated that the toner has excellent low-temperature fixation properties and prevents filming. Patent Document 2 describes a pulverized toner produced by melt kneading, comprising an amorphous polyester A which is a polycondensate of an alcohol component containing an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom having 3 to 5 carbon atoms and a carboxylic acid component containing an aromatic dicarboxylic acid compound, and a crystalline polyester C which is a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound, wherein the glass transition temperature of amorphous polyester A is within a specific range, and the solubility parameter of amorphous polyester A, the solubility parameter of crystalline polyester C, and the crystallization temperature satisfy a specific relationship, and the toner is described as having excellent low-temperature fixability, heat resistance for storage, and suppression of streaking. Patent Document 3 describes a toner binder resin composition for electrostatic image developing, which contains an amorphous resin containing polyester resin A, which is a polycondensate of an alcohol component containing an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom, a carboxylic acid component, and polyethylene terephthalate, and a crystalline resin containing polyester resin C, which is a polycondensate of an alcohol component containing 50 mol% to 100 mol% of ethylene glycol, wherein the mass ratio of the amorphous resin to the crystalline resin is within a specific range, and the toner for electrostatic image developing is described as having excellent low-temperature fixability, long-term stability of low-temperature fixability, and durability. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2016-145857 [Patent Document 2] Japanese Patent Publication No. 2018-59964 [Patent Document 3] Japanese Patent Publication No. 2019-66536 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Although the toners described in Patent Documents 1 to 3 exhibit the effects described above, they are manufactured by a grinding method, which exposes crystalline polyester on the surface. As a result, they have the problem of having a wide charge distribution and being prone to fogging. This invention relates to a method for manufacturing a toner for developing electrostatic images that exhibits excellent low-temperature fixing properties and a narrow charge distribution. [Means for solving the problem]

[0006] The present inventors have found that a toner for developing electrostatic images, manufactured by a method including the steps of agglomerating and fusing resin particles containing the same or different resins, in an aqueous medium, exhibits excellent low-temperature fixing properties and a narrow charge distribution. This toner contains an amorphous polyester resin (A), which is a polycondensate of an alcohol component (a) containing an aliphatic diol with 2 to 5 carbon atoms and a carboxylic acid component (b), and a crystalline polyester resin (C), which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d). The present invention relates to the following [1]. [1] A method for manufacturing toner for electrostatic image development, comprising the steps of agglomerating and fusing resin particles containing amorphous resin and crystalline resin in the same or different particles in an aqueous medium, The amorphous resin contains an amorphous polyester resin (A) which is a polycondensate of an alcohol component (a) containing an aliphatic diol having 2 to 5 carbon atoms and a carboxylic acid component (b), The crystalline resin contains a crystalline polyester resin (C) which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d). A method for manufacturing toner for developing electrostatic images. [Effects of the Invention]

[0007] The present invention provides a method for manufacturing a toner for developing electrostatic images that exhibits excellent low-temperature fixing properties and a narrow charge distribution. [Modes for carrying out the invention]

[0008] [Manufacturing method for toner for electrostatic image development] The present invention provides a method for producing a toner for electrostatic image development (hereinafter also simply referred to as "toner"), which includes a step of agglomerating and a step of fusing resin particles containing amorphous resin and crystalline resin in the same or different particles in an aqueous medium. The amorphous resin contains an amorphous polyester resin (A) (hereinafter also simply referred to as "resin (A)") which is a polycondensate of an alcohol component (a) containing an aliphatic diol having 2 to 5 carbon atoms and a carboxylic acid component (b). The crystalline resin contains a crystalline polyester resin (C) (hereinafter also simply referred to as "resin (C)") which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d). The above manufacturing method yields a toner with excellent low-temperature fixing properties and a narrow charge distribution.

[0009] The detailed mechanism by which the manufacturing method of the present invention yields a toner with excellent low-temperature fixation properties and a narrow charge distribution is not yet clear, but it is thought to be as follows. In chemical toners produced by conventional emulsion aggregation methods, the hydrophobic crystalline polyester resin among binder resins is mostly present inside the toner by avoiding the interface with water during production, so conventional chemical toners are disadvantageous in terms of rapid thermal responsiveness during fixing. In contrast, in the production method of the present invention, by using a crystalline resin containing a crystalline polyester resin (C) whose hydrophilicity is relatively improved by including ethylene glycol in the alcohol component (c), the resin (C) can be present closer to the toner surface. Therefore, it is considered that the thermal responsiveness of the toner is improved, the toner can be melted by instantaneous heating during fixing, and a toner excellent in high-speed low-temperature fixability can be produced. Furthermore, by using an amorphous polyester resin (A) which is a polycondensate of an alcohol component (a) containing an aliphatic diol having 2 to 5 carbon atoms and a carboxylic acid component (b), the hydrophilicity of the amorphous resin is also improved, and in the step of aggregating resin particles, an amorphous resin containing the amorphous polyester resin (A), which has higher hydrophilicity than the resin (C), is present on the outermost surface of the aggregated particles. Therefore, in the fused particles obtained in the step of fusing the aggregated particles, the surface exposure of the resin (C) is suppressed, whereby a toner with a narrow charge amount distribution can be obtained, and it is considered that the chargeability of the toner is improved. This effect is not limited to the case where the amorphous resin containing the resin (A) and the crystalline resin containing the resin (C) are contained in different resin particles respectively, it is considered that the same effect can be obtained also when the amorphous resin containing the resin (A) and the crystalline resin containing the resin (C) are contained in the same resin particle.

[0010] Definitions of various terms used in the present specification are shown below. In the specification, the carboxylic acid component of the polyester-based resin includes not only the compound itself, but also anhydrides that decompose to generate carboxylic acid during the reaction, and alkyl esters of each carboxylic acid (where the alkyl group has 1 or more and 3 or less carbon atoms). Whether a resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum endothermic peak temperature (softening point (°C) / maximum endothermic peak temperature (°C)) in the measurement method described in the examples mentioned later. A crystalline resin is one having 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 when an endothermic peak is observed, the crystallinity index is less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted according to production conditions such as the type and ratio of raw material monomers, reaction temperature, reaction time, and cooling rate. With respect to hydrocarbon groups, descriptions with "(iso or tertiary)" and "(iso)" in parentheses mean both cases where these prefixes are present and where they are absent, and when these prefixes are absent, it indicates normal. "(Meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid. "(Meth)acrylate" means at least one selected from acrylate and methacrylate. "(Meth)acryloyl group" means at least one selected from an acryloyl group and a methacryloyl group. "Styrenic compound" means unsubstituted or substituted styrene. "Main chain" means the relatively longest bonding chain in an addition polymer.

[0011] A method for producing a toner according to one embodiment of the present invention includes a step of aggregating and a step of fusing resin particles containing an amorphous resin and a crystalline resin in the same or different particles in an aqueous medium. The resin particles can be obtained, for example, by a phase inversion emulsification method using an amorphous resin and / or a crystalline resin as described later. Hereinafter, the present invention will be described by taking this embodiment as an example.

[0012] [Step of aggregating resin particles] In the step of agglomerating resin particles, resin particles containing amorphous resin and crystalline resin in the same or different particles are agglomerated in an aqueous medium to obtain agglomerated particles 1. Here, it is preferable to further agglomerate at least one of a colorant and a release agent in addition to the resin particles, and it is more preferable to agglomerate these particles by mixing a resin particle dispersion containing resin particles with a colorant particle dispersion containing colorant particles and / or a release agent particle dispersion containing release agent particles. It is even more preferable that the resin particle dispersion, colorant particle dispersion, and release agent particle dispersion are aqueous dispersions of resin particles, colorant particles, and release agent particles, respectively.

[0013] [Amorphous resin] The amorphous resin is used as a binder resin for toner and contains amorphous polyester resin (A), which is a polycondensate of an alcohol component (a) containing an aliphatic diol with 2 to 5 carbon atoms and a carboxylic acid component (b). Resin (A) has higher hydrophilicity than crystalline polyester resin (C). Therefore, it is believed that amorphous resin is present on the outermost surface of the toner obtained by the manufacturing method of the present invention, and that surface exposure of resin (C) is suppressed.

[0014] [Amorphous polyester resin (A)] The polyester resin (A) is a polycondensate of an alcohol component (a) and a carboxylic acid component (b), and the alcohol component contains an aliphatic diol having 2 to 5 carbon atoms. Examples of aliphatic diols having 2 to 5 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, and neopentyl glycol. Preferably, the aliphatic diol having 2 to 5 carbon atoms is ethylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, and neopentyl glycol, and more preferably ethylene glycol, 1,2-propanediol, 2,3-butanediol, and neopentyl glycol. In the alcohol component (a), the content of aliphatic diols having 2 to 5 carbon atoms is preferably 85 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, and preferably 100 mol%, from the viewpoint of suppressing surface exposure of the crystalline polyester resin (C).

[0015] Examples of alcohol components (a) other than aliphatic diols having 2 to 5 carbon atoms include alkylene oxide adducts of aromatic diols, aliphatic diols having 6 or more carbon atoms, alicyclic diols, and polyhydric alcohols with a valency of 3 or higher. Preferably, the alkylene oxide adduct of an aromatic diol is of formula (I):

[0016] [ka] It is preferable to include an alkylene oxide adduct of bisphenol A represented by the formula (wherein OR and RO are oxyalkylene groups, R is independently an ethylene or propylene group, x and y represent the average number of moles of alkylene oxide added, each being a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, 16 or less, preferably 8 or less, and more preferably 4 or less). Examples of alkylene oxide adducts of bisphenol A represented by formula (I) include propylene oxide adducts of 2,2-bis(4-hydroxyphenyl)propane and ethylene oxide adducts of 2,2-bis(4-hydroxyphenyl)propane. One or more of these may be used.

[0017] Examples of aliphatic diols having 6 or more carbon atoms include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and 1,4-butenediol. Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and alkylene oxide adducts of hydrogenated bisphenol A with 2 to 4 carbon atoms (average number of added moles: 2 to 12). Examples of polyhydric alcohols with a valency of 3 or higher include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used individually or in combination of two or more types.

[0018] Examples of carboxylic acid component (b) include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds. Among these, the carboxylic acid component (b) preferably includes an aromatic dicarboxylic acid compound, from the viewpoint of suppressing surface exposure of the resin (C). Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, and terephthalic acid. Of these, at least one selected from terephthalic acid and isophthalic acid is more preferred from the above viewpoint. The content of the aromatic dicarboxylic acid compound in the carboxylic acid component (b) is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and preferably 100 mol% or less, from the viewpoint of suppressing surface exposure of the resin (C).

[0019] Examples of aliphatic dicarboxylic acid compounds include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, and other aliphatic dicarboxylic acids that may be substituted with aliphatic hydrocarbon groups having 1 to 20 carbon atoms. Examples of succinic acid substituted with aliphatic hydrocarbon groups having 1 to 20 carbon atoms include octyl succinic acid and dodecenyl succinic acid (tetrapropenyl succinic acid). Among these, fumaric acid is preferred. The content of the aliphatic dicarboxylic acid compound in the carboxylic acid component (b) is preferably 40 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, and preferably 0 mol% or more, from the viewpoint of obtaining a toner with excellent low-temperature fixability.

[0020] Examples of trivalent or higher carboxylic acid compounds include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalentricarboxylic acid, and pyromellitic acid. Among these, trimellitic acid and its anhydride are preferred. The content of trivalent or higher carboxylic acid compounds in carboxylic acid component (b) is preferably 60 mol% or less, more preferably 30 mol% or less, even more preferably 10 mol% or less, and 0 mol% or more, from the viewpoint of low-temperature fixability. The alcohol component (a) may optionally contain a monohydric alcohol, and the carboxylic acid component (b) may optionally contain a monohydric carboxylic acid compound.

[0021] The equivalent ratio [COOH group / OH group] of the carboxyl group of the carboxylic acid component (b) to the hydroxyl group of the alcohol component (a) is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0022] (Method of manufacturing polyester resin (A)) The resin (A) may be produced, for example, by polycondensation of raw material monomers containing an alcohol component (a) and a carboxylic acid component (b).

[0023] The polycondensation of the alcohol component (a) and the carboxylic acid component (b) can be carried out, for example, in an inert gas atmosphere, at a temperature of approximately 120°C to 250°C, in the presence of an esterification catalyst, esterification co-catalyst, polymerization inhibitor, etc., as needed. Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) di(2-ethylhexanoate), and titanium compounds such as titanium diisopropoxybis(triethanolamine). Examples of esterification co-catalysts that can be used together with the esterification catalyst include gallic acid. The amount of esterification catalyst used is preferably 0.01 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the total amount of the alcohol component (a) and carboxylic acid component (b), which are raw material monomers of the resin (A). The amount of esterification co-catalyst used is preferably 0.001 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the total amount of alcohol component (a) and carboxylic acid component (b). Examples of polymerization inhibitors include radical polymerization inhibitors such as 4-tert-butylcatechol. When a polymerization inhibitor is used, the amount of polymerization inhibitor used is preferably 0.001 parts by mass or more and 1 part by mass or less per 100 parts by mass of the total amount of alcohol component (a) and carboxylic acid component (b).

[0024] (Physical properties of polyester resin (A)) The softening point of resin (A) is preferably 70°C or higher, more preferably 80°C or higher, and even more preferably 90°C or higher, from the viewpoint of heat-resistant storage, and preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixing properties. The glass transition temperature of resin (A) is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 45°C or higher, from the viewpoint of heat-resistant storage, and preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 60°C or lower, from the viewpoint of low-temperature fixing properties.

[0025] The acid value of resin (A) is preferably 5 mg KOH / g or more, more preferably 10 mg KOH / g or more, even more preferably 15 mg KOH / g or more, and preferably 40 mg KOH / g or less, more preferably 30 mg KOH / g or less, and even more preferably 25 mg KOH / g or less. The softening point, glass transition temperature, and acid value of resin (A) can be appropriately adjusted depending on the type and amount of raw material monomer used, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. These values ​​can be determined by the method described in the examples. Furthermore, when using two or more types of resin (A) in combination, it is preferable that the softening point, glass transition temperature, and acid value obtained from the mixture thereof are within the aforementioned ranges.

[0026] The amorphous resin preferably contains 90% by mass or more of amorphous polyester resin (A). From the viewpoint of suppressing surface exposure of resin (C), the content of resin (A) in the amorphous resin is more preferably 92% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, and 100% by mass or less, and preferably 100% by mass.

[0027] [Amorphous polyester resin (B)] The amorphous resin may contain resins other than resin (A) as long as it does not impair the effects of the present invention. Examples of such resins include amorphous polyester resins (B) (hereinafter also simply referred to as "resin (B)") in which the alcohol component does not contain aliphatic diols having 2 to 5 carbon atoms, and other polyester resins. Examples of resin (B) 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 polymerization resin segments. Among these, polyester resins and composite resins containing polyester resin segments and addition polymerization resin segments are preferred.

[0028] Examples of the alcohol component of resin (B) include alkylene oxide adducts of aromatic diols, aliphatic diols, alicyclic diols, and polyhydric alcohols of trihydric or higher hydric value. An example of an alkylene oxide adduct of an aromatic diol is the alkylene oxide adduct of bisphenol A represented by formula (I) in resin (A) described above, and the preferred range is the same. The content of the bisphenol A alkylene oxide adduct is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, and more preferably 100 mol%, in the alcohol component.

[0029] Aliphatic diols include all aliphatic diols except those with 2 to 5 carbon atoms.

[0030] Examples of alicyclic diols and polyhydric alcohols with a valency of 3 or higher include the alicyclic diols and polyhydric alcohols with a valency of 3 or higher in the resin (A) described above, and the preferred range is the same.

[0031] Examples of carboxylic acid components in resin (B) include those exemplified in resin (A) above, specifically aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds. The amount of aromatic dicarboxylic acid is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 75 mol% or less, in the carboxylic acid component.

[0032] The amount of aliphatic dicarboxylic acid is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less, in the carboxylic acid component.

[0033] When a polycarboxylic acid with three or more valent properties is included, the amount of the polycarboxylic acid with three or more valent properties is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, and preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 15 mol% or less, in the carboxylic acid component. These carboxylic acid components may be used individually or in combination of two or more types.

[0034] The equivalent ratio [COOH group / OH group] of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0035] If resin (B) is a composite resin, the same composite resin as composite resin (D) described later can be used.

[0036] (Method for producing amorphous polyester resin (B)) If resin (B) is a polyester resin, resin (B) can be produced by the same method as the method for producing polyester resin (A) described above, and the reaction conditions are also the same.

[0037] If resin (B) is a composite resin comprising a polyester resin segment and an addition polymerization resin segment, resin (B) may be manufactured, for example, by the same method as the method for manufacturing composite resin (D) described later.

[0038] (Physical properties of amorphous polyester resin (B)) The softening point of resin (B) is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 95°C or higher. Furthermore, from the viewpoint of further improving low-temperature fixability, it is preferably 150°C or lower, more preferably 140°C or lower, and even more preferably 125°C or lower. The glass transition temperature of resin (B) is preferably 30°C or higher, more preferably 35°C or higher, and even more preferably 40°C or higher, and from the viewpoint of further improving low-temperature fixation, it is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower.

[0039] The acid value of resin (B) is preferably 5 mg KOH / g or more, more preferably 10 mg KOH / g or more, even more preferably 15 mg KOH / g or more, and preferably 40 mg KOH / g or less, more preferably 35 mg KOH / g or less, and even more preferably 30 mg KOH / g or less. The softening point, glass transition temperature, and acid value of resin (B) can be appropriately adjusted depending on the type and amount of raw material monomer used, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. These values ​​can be determined by the method described in the examples. Furthermore, when using two or more types of resin (B) in combination, it is preferable that the softening point, glass transition temperature, and acid value obtained from the mixture thereof are within the aforementioned ranges.

[0040] [Crystalline resin] The crystalline resin is used as a binder resin for toner and contains a crystalline polyester resin (C), which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d). Because resin (C) has a structure derived from the alcohol component (c) containing ethylene glycol, its hydrophilicity is relatively improved. Therefore, in the manufacturing method of the present invention, it is considered possible for resin (C) to be present near the surface of the aggregated particles 1 during emulsification and aggregation.

[0041] [Crystalline polyester resin (resin (C))] The resin (C) is a polycondensate of the alcohol component (c) and the carboxylic acid component (d). The alcohol component (c) contains ethylene glycol. The alcohol component (c) may include an α,ω-aliphatic diol in addition to ethylene glycol. Examples of α,ω-aliphatic diols include 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.

[0042] In the alcohol component (c), the ethylene glycol content is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, and even more preferably 100 mol%, from the viewpoint of improving the hydrophilicity of the resin (C).

[0043] Alcohol component (c) may contain other alcohol components different from α,ω-aliphatic diols. Examples of other alcohol components include aliphatic diols other than α,ω-aliphatic diols, aromatic diols, trivalent or higher alcohols, etc. One or more of these alcohol components may be used.

[0044] The carboxylic acid component (d) preferably includes an aliphatic dicarboxylic acid. The number of carbon atoms in the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 14 or less, more preferably 12 or less, from the viewpoint of improving the hydrophilicity of resin (C) and balancing the hydrophilicity of resin (A). Examples of aliphatic dicarboxylic acids include fumaric acid, succinic acid, adipic acid, sebacic acid, dodecanediic acid, and tetradecanediic acid. Among these, linear saturated aliphatic dicarboxylic acids are preferred, with sebacic acid, dodecanediic acid, and tetradecanediic acid being preferred, and sebacic acid being more preferred. One or more of these carboxylic acid components may be used.

[0045] From the viewpoint of improving the hydrophilicity of resin (C) and balancing the hydrophilicity of resin (C) and resin (A), the amount of aliphatic dicarboxylic acid is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, and even more preferably 100 mol%.

[0046] The carboxylic acid component may contain other carboxylic acid components other than aliphatic dicarboxylic acids. Examples of other carboxylic acid components include monovalent carboxylic acids such as stearic acid; aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; and polyvalent carboxylic acids of three or more valents. One or more of these carboxylic acid components may be used.

[0047] The equivalent ratio [COOH group / OH group] of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0048] (Physical properties of resin (C)) The softening point of resin (C) is preferably 60°C or higher, more preferably 65°C or higher, even more preferably 70°C or higher, and preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of heat-resistant storage. The melting point of resin (C) is preferably 50°C or higher, more preferably 55°C or higher, even more preferably 60°C or higher, and preferably 140°C or lower, more preferably 110°C or lower, and even more preferably 100°C or lower, from the viewpoint of heat-resistant storage.

[0049] The acid value of resin (C) is preferably 5 mg KOH / g or more, more preferably 8 mg KOH / g or more, and more preferably 25 mg KOH / g or less, more preferably 20 mg KOH / g or less, and even more preferably 15 mg KOH / g or less.

[0050] The softening point, melting point, and acid value of resin (C) can be appropriately adjusted depending on the type and ratio of raw material monomers, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. These values ​​can be determined by the method described in the examples below. When two or more types of resin (C) are used in combination, it is preferable that the softening point, melting point, and acid value obtained from the mixture thereof are within the aforementioned ranges.

[0051] Resin (C) is obtained, for example, by polycondensation of an alcohol component (c) and a carboxylic acid component (d). The conditions for polycondensation can be, for example, those shown for polycondensation in resin (A) described above.

[0052] The crystalline resin preferably contains 90% by mass or more of crystalline polyester resin (C). From the viewpoint of obtaining a toner with excellent low-temperature fixability, the content of resin (C) in the crystalline resin is more preferably 92% by mass or more, even more preferably 95% by mass or more, even more preferably 97% by mass or more, and 100% by mass or less, and preferably 100% by mass.

[0053] The total content of resin (A) and resin (C) in the amorphous resin and crystalline resin in the resin particles is preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less, and preferably 100% by mass, from the viewpoint of obtaining a toner with excellent low-temperature fixing properties and a narrow charge distribution.

[0054] The mass ratio of resin (C) to resin (A) [resin (C) / resin (A)] is preferably 5 / 95 or higher, more preferably 10 / 90 or higher, even more preferably 15 / 85 or higher, and preferably 40 / 60 or lower, more preferably 30 / 70 or lower, and even more preferably 25 / 75 or lower, from the viewpoint of obtaining a toner with excellent low-temperature fixing properties and a narrow charge distribution.

[0055] [Method for manufacturing resin particles] Amorphous resin particles and crystalline resin particles may be manufactured as aqueous dispersions of resin particles containing amorphous resin and crystalline resin in the same or different particles. A water-based medium is preferred for use in the aqueous dispersion.

[0056] Dispersion can be carried out using known methods, but dispersion by phase inversion emulsification is preferred. Examples of phase inversion emulsification methods include adding an aqueous medium to an organic solvent solution of amorphous resin and / or crystalline resin, or to molten amorphous resin and / or crystalline resin, and then performing phase inversion emulsification. Adding an aqueous medium to an organic solvent solution of resin and then performing phase inversion emulsification is preferred. For example, by adding an aqueous medium to an organic solvent solution of amorphous resin and crystalline resin and performing phase inversion emulsification, an aqueous dispersion of resin particles containing amorphous resin and crystalline resin in the same particle can be produced. The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves amorphous and crystalline resins and is water-soluble, but an example is methyl ethyl ketone. A neutralizing agent may be added to the organic solvent solution. Examples of neutralizing agents include basic substances. Examples of basic substances include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine, and diethanolamine. Among these, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide are preferred. The degree of neutralization of amorphous resin and / or crystalline 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 preferably 100 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. The degree of neutralization of amorphous and / or crystalline resins contained in resin particles can be determined by the following formula. Degree of neutralization (mol%) = [{Amount of neutralizing agent added (g) / Equivalent amount of neutralizing agent} / [{Weighted average acid value of the resin constituting the resin particles (mgKOH / g) × Mass of the resin constituting the resin particles (g)} / (56 × 1000)]] × 100

[0057] While stirring the organic solvent solution or molten resin, gradually add an aqueous medium to induce phase inversion. When adding an aqueous medium, the temperature of the organic solvent solution is preferably above the glass transition temperature of resin (A), more preferably above 60°C, even more preferably above 65°C, even more preferably above 70°C, and preferably below 100°C, more preferably below 90°C, and even more preferably below 80°C, from the viewpoint of improving the dispersion stability of resin particles including amorphous resin and / or crystalline resin.

[0058] After phase inversion emulsification, the organic solvent may be removed from the resulting dispersion by distillation or other means, if necessary. Alternatively, the resin particles may be isolated by filtration or other means. In the aggregation and fusion steps of the present invention, it is preferable to use an aqueous dispersion of resin particles from which the organic solvent has been removed after phase inversion emulsification. In this case, the amount of residual organic solvent is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably substantially 0% by mass in the dispersion.

[0059] Volume median particle size D of resin particles in dispersion 50 From the viewpoint of obtaining a toner with excellent low-temperature fixation properties and a narrow charge distribution, the particle size is preferably 0.05 μm or more, more preferably 0.08 μm or more, and 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 with excellent low-temperature fixation properties and a narrow charge distribution, the CV value of the resin particles in the dispersion is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less.

[0060] The solid content concentration of the aqueous dispersion of 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 preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 25% by mass or less, from the viewpoint of improving toner productivity and improving the dispersion stability of the aqueous dispersion of resin particles. Note that the solid content represents the total amount of non-volatile components. Furthermore, in the process of agglomerating resin particles, the agglomerated particles 1 may contain a coloring agent and / or a mold release agent, and may also contain other additives such as a charge control agent, magnetic powder, flowability improver, conductivity modifier, reinforcing filler such as fibrous material, antioxidant, anti-aging agent, and cleaning properties improver.

[0061] [Aqueous medium] In the present invention, the aqueous medium is a medium whose main component is water, and the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and 100% by mass or less. Deionized water, ion-exchanged water, or distilled water are preferred as the water. Other components that can form an aqueous medium together with water include alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and organic solvents that dissolve in water, such as cyclic ethers such as tetrahydrofuran. Among these, alkyl alcohols having 1 to 5 carbon atoms are preferred, and ethanol is more preferred.

[0062] [Coloring agents] It is preferable to include the coloring agent in the aggregated particles 1 by mixing it with resin particles as a dispersion of coloring agent particles and causing aggregation. As a coloring agent, all dyes, pigments, etc. used as coloring agents for toners can be used. Examples of colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazo yellow. The toner may be either black toner or a color toner other than black.

[0063] (Dispersion of coloring agent particles) The colorant particles are preferably incorporated into aggregated particles 1 by mixing them with resin particles as a dispersion of colorant particles and agglomerating them. It is preferable to obtain the colorant by dispersing the colorant and an aqueous medium using a disperser such as a homogenizer or an ultrasonic disperser. From the viewpoint of improving the dispersion stability of the colorant, it is preferable to carry out this dispersion in the presence of an addition polymer (hereinafter, the addition polymer used for dispersing the colorant is also referred to as "addition polymer E") or a surfactant. Examples of such surfactants include nonionic surfactants, anionic surfactants, and cationic surfactants. The addition polymer E preferably has structural units derived from addition polymerizable monomer a having an aromatic group, and more preferably further contains at least one selected from the group consisting of addition polymerizable monomer b having an ionic group, addition polymerizable monomer c having a polyalkylene oxide group, and macromonomer d. For the colorant particle dispersion and the addition polymer E, refer to the addition polymer E described in Japanese Patent Application Publication No. 2021-026129.

[0064] [Release agent] It is preferable to incorporate the release agent into the aggregated particles 1 by mixing it with resin particles as a dispersion of release agent particles containing the release agent and causing aggregation. Examples of release agents include polypropylene wax, polyethylene wax, polypropylene-polyethylene copolymer wax; hydrocarbon waxes such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and sazole wax, or their oxides; ester waxes such as carnauba wax, montane wax, or their deoxidizing waxes, and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. One or more of these may be used.

[0065] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and more preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 100°C or lower. The release agent content is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, in the toner particles.

[0066] (Release agent particle dispersion) While the mold release agent particle dispersion can be obtained using a surfactant, it is preferable to obtain it by mixing the mold release agent with the resin particles S described later. By preparing the mold release agent particles using the mold release agent and the resin particles S, the mold release agent particles are stabilized by the resin particles S, making it possible to disperse the mold release agent in an aqueous medium without using a surfactant. In the mold release agent particle dispersion, it is thought that the mold release agent particles have a structure in which many resin particles S are attached to the surface.

[0067] The resin constituting the resin particles S in which the mold release agent is dispersed is preferably a polyester resin, and it is more preferable to use a composite resin (D) having polyester resin segments and addition polymerization resin segments. [Composite resin (D)] The composite resin (D) is a modified polyester resin, and examples include a composite resin comprising a polyester resin segment and an addition polymerization resin segment.

[0068] Examples of the alcohol component of composite resin (D) include alkylene oxide adducts of aromatic diols, aliphatic diols, alicyclic diols, and polyhydric alcohols of trihydric or higher valency. An example of an alkylene oxide adduct of an aromatic diol is the alkylene oxide adduct of bisphenol A represented by formula (I) in resin (A) described above, and the preferred range is the same. The content of the bisphenol A alkylene oxide adduct is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, and more preferably 100 mol%, in the alcohol component.

[0069] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol.

[0070] Examples of alicyclic diols and polyhydric alcohols with a valency of 3 or higher include the alicyclic diols and polyhydric alcohols with a valency of 3 or higher in the resin (A) described above, and the preferred range is the same.

[0071] Examples of carboxylic acid components in composite resin (D) include those exemplified in resin (A) described above, specifically aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds. Among these, terephthalic acid and succinic acid are preferred. The amount of aromatic dicarboxylic acid is preferably 20 mol% or more, more preferably 30 mol% or more, even more preferably 40 mol% or more, and preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 75 mol% or less, in the carboxylic acid component.

[0072] The amount of aliphatic dicarboxylic acid is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 60 mol% or less, in the carboxylic acid component.

[0073] When a polycarboxylic acid with three or more valent properties is included, the amount of the polycarboxylic acid with three or more valent properties is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 8 mol% or more, and preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 15 mol% or less, in the carboxylic acid component. These carboxylic acid components may be used individually or in combination of two or more types.

[0074] The equivalent ratio [COOH group / OH group] of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.7 or higher, more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0075] Examples of addition polymerization resin segments of composite resin (D) include addition polymerization products of raw material monomers containing styrene compounds. Examples of styrene compounds include unsubstituted or substituted styrene. Examples of substituents that can be substituted for styrene include alkyl groups having 1 to 5 carbon atoms, halogen atoms, alkoxy groups having 1 to 5 carbon atoms, sulfonic acid groups, or salts thereof. Examples of styrene-based compounds include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrene sulfonic acid, or salts thereof. Among these, styrene is preferred. The content of styrene compounds in the raw material monomers of the addition polymerization resin segment is preferably 50% by mass or more, more preferably 65% ​​by mass or more, even more preferably 75% by mass or more, and 100% by mass or less, preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0076] Other raw material monomers besides styrene compounds include, for example, (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylate is more preferred. The number of carbon atoms in the alkyl group of (meth)acrylate is preferably 1 or more, more preferably 4 or more, even more preferably 6 or more, and preferably 24 or less, more preferably 22 or less, and even more preferably 20 or less. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, iso(or tertiary)butyl (meth)acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, isododecyl (meth)acrylate, isopalmityl (meth)acrylate, isostearyl (meth)acrylate, isobehenyl (meth)acrylate, and so on. Preferably, 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate, more preferably stearyl (meth)acrylate, and even more preferably stearyl methacrylate.

[0077] The content of (meth)acrylic acid ester in the raw material monomer of the addition polymerization resin segment is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 35% by mass or less, and even more preferably 25% by mass or less. The total amount of styrene compounds and (meth)acrylic acid esters in the raw material monomers of the addition polymerization resin segment is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass.

[0078] The composite resin (D) preferably has constituent units derived from both reactive monomers that are covalently bonded to the polyester resin segment and the addition polymerization resin segment. "Constituent units derived from both reactive monomers" refers to units formed by the reaction of the functional groups and addition polymerizable groups of both reactive monomers. Examples of addition polymerizable groups include carbon-carbon unsaturated bonds (ethylenically unsaturated bonds). Examples of both reactive monomers include addition polymerizable monomers having at least one functional group selected from hydroxyl groups, carboxyl groups, epoxy groups, primary amino groups, and secondary amino groups within the molecule. Among these, addition polymerizable monomers having at least one functional group selected from hydroxyl groups and carboxyl groups are preferred from the viewpoint of reactivity, and addition polymerizable monomers having carboxyl groups are more preferred. Examples of addition polymerizable monomers having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, acrylic acid and methacrylic acid are preferred from the viewpoint of reactivity in both polycondensation and addition polymerization reactions, with acrylic acid being more preferred. When both reactive monomers are addition polymerizable monomers having a carboxyl group, the amount of constituent units derived from both reactive monomers is preferably 1 mole or more, more preferably 5 moles or more, even more preferably 8 moles or more, and preferably 30 moles or less, more preferably 25 moles or less, and even more preferably 20 moles or less, per 100 moles of the alcohol component of the polyester resin segment of the composite resin (D).

[0079] The polyester resin segment content in the composite resin (D) is preferably 35% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 75% by mass or less.

[0080] The content of the addition polymerization resin segment in the composite resin (D) is preferably 5% by mass or more, more preferably 15% by mass or more, even more preferably 25% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 45% by mass or less.

[0081] The amount of constituent units derived from both reactive monomers in the composite resin (D) 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, and preferably 10% by mass or less, more preferably 7% by mass or less, and even more preferably 4% by mass or less.

[0082] The total amount of the polyester resin segment, the addition polymerization resin segment, and the constituent units derived from both reactive monomers in the composite resin (D) 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.

[0083] The above amounts are calculated based on the ratio of the raw material monomers for the polyester resin segment, the addition polymerization resin segment, the two reactive monomers, and the radical polymerization initiator. The mass of the polyester resin segment, etc., is based on the mass excluding the mass of water produced by polycondensation. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is included in the calculation of the addition polymerization resin segment.

[0084] (Method for manufacturing composite resin (D)) If the composite resin (D) is a composite resin comprising a polyester resin segment and an addition polymerization resin segment, it may be produced, for example, by a method comprising step A of polycondensing an alcohol component and a carboxylic acid component, and step B of addition polymerization of the raw material monomers of the addition polymerization resin segment and both reactive monomers. Process A may be performed after process B, or process B may be performed after process A, or process A and process B may be performed simultaneously. In step A, a portion of the carboxylic acid component is subjected to a polycondensation reaction, and then step B is carried out. After that, the remaining carboxylic acid component is added to the polymerization system to further advance the polycondensation reaction in step A and the polycondensation reaction with the carboxyl groups of both reactive monomers or constituent parts derived from both reactive monomers.

[0085] In step A, if necessary, the esterification catalyst and esterification co-catalyst described in the method for producing the polyester resin (A) may be used in the same amounts for polycondensation. Furthermore, when using monomers having unsaturated bonds, such as fumaric acid, in polycondensation, the polymerization inhibitor described in the method for producing polyester resin (A) above may be used in the same amount as necessary. The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, even more preferably 180°C or higher, and preferably 250°C or lower, more preferably 240°C or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0086] Examples of radical polymerization initiators for the addition polymerization in step B include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of radical polymerization initiator used is preferably 1 to 20 parts by mass per 100 parts by mass of raw material monomers of the addition polymerization resin segment. The addition polymerization temperature is preferably 110°C or higher, more preferably 130°C or higher, and preferably 230°C or lower, more preferably 220°C or lower, and even more preferably 210°C or lower.

[0087] The softening point of the composite resin (D) is preferably 70°C or higher, more preferably 80°C or higher, even more preferably 85°C or higher, and preferably 140°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower. The glass transition temperature of the composite resin (D) is preferably 30°C or higher, more preferably 35°C or higher, and even more preferably 40°C or higher, and from the viewpoint of further improving low-temperature fixation, it is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 60°C or lower.

[0088] The acid value of the composite resin (D) is preferably 5 mg KOH / g or more, more preferably 10 mg KOH / g or more, even more preferably 15 mg KOH / g or more, even more preferably 20 mg KOH / g or more, and preferably 40 mg KOH / g or less, more preferably 35 mg KOH / g or less, and even more preferably 30 mg KOH / g or less, from the viewpoint of obtaining fine resin particles and fine release agent particle dispersions.

[0089] The softening point, glass transition temperature, and acid value of composite resin (D) can be appropriately adjusted depending on the type and amount of raw material monomers used, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate. These values ​​can be determined by the method described in the examples. Furthermore, when using two or more composite resins (D) in combination, it is preferable that the softening point, glass transition temperature, and acid value obtained from the mixture thereof are within the aforementioned ranges.

[0090] A dispersion of resin particles S can be obtained, for example, by the phase inversion emulsification method described above. Volume-intermediate particle size D of resin particles S 50 From the viewpoint of the dispersion stability of the release agent particles, the particle size is preferably 0.01 μm or larger, more preferably 0.03 μm or larger, and preferably 3.0 μm or smaller, more preferably 1.0 μm or smaller. The CV value of the resin particles S is preferably 10% or more, more preferably 15% or more, and more preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less, from the viewpoint of the dispersion stability of the release agent particles. Volume-intermediate particle size D of resin particles S 50 The CV value is measured by the method described in the examples.

[0091] A mold release agent particle dispersion can be obtained, for example, by dispersing a dispersion of a mold release agent and resin particles S, along with an aqueous medium as needed, at a temperature above the melting point of the mold release agent using a disperser such as a homogenizer, high-pressure disperser, or ultrasonic disperser. The heating temperature during dispersion is preferably above the melting point of the release agent and 80°C or higher, more preferably 85°C or higher, and even more preferably 90°C or higher. Furthermore, it is preferably less than 10°C higher than the softening point of the resin contained in the resin particles S and 100°C or lower, more preferably 98°C or lower, and even more preferably 95°C or lower.

[0092] The amount of resin particles S is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and preferably 100 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of the release agent.

[0093] Release agent particle volume median particle size D 50 From the viewpoint of obtaining uniform aggregated particles 1 by aggregation, the particle size is preferably 0.05 μm or larger, more preferably 0.1 μm or larger, even more preferably 0.2 μm or larger, and preferably 1 μm or smaller, more preferably 0.8 μm or smaller, and even more preferably 0.6 μm or smaller. The CV value of the release agent particles is preferably 10% or more, more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, and even more preferably 30% or less. Release agent particle volume median particle size D 50 The CV value is measured by the method described in the examples.

[0094] The aggregated particles 1 may also contain other additives such as charge control agents, magnetic powders, flowability enhancers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, anti-aging agents, and cleaning properties enhancers.

[0095] [Surfactants] In the process of agglomerating resin particles, when mixing the dispersions of each particle to prepare a mixed dispersion, the process may be carried out in the presence of a surfactant from the viewpoint of improving the dispersion stability of resin particles, release agent particles, colorant particles, etc. Examples of surfactants include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers. When a surfactant is used, the total amount used is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, even more preferably 0.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of the total amount of resin particles.

[0096] [Flocculant] In the process of agglomerating resin particles, it is preferable to add a flocculant from the viewpoint of efficiently carrying out the agglomeration. Examples of flocculants include cationic surfactants such as quaternary salts, organic flocculants such as polyethyleneimine, and inorganic flocculants. Examples of inorganic flocculants include inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate; and metal complexes with a valency of 2 or higher. From the viewpoint of improving cohesiveness and obtaining uniform aggregated particles 1, inorganic flocculants with a valency of 1 to 5 are preferred, inorganic metal salts and inorganic ammonium salts with a valency of 1 to 2 are more preferred, inorganic ammonium salts are even more preferred, and ammonium sulfate is even more preferred.

[0097] Using a flocculant, for example, 5 to 50 parts by mass of a flocculant per 100 parts by mass of resin in a mixed dispersion containing resin particles, release agent particles, and colorant particles at a temperature of 0°C to 40°C, the resin particles, release agent particles, and colorant particles are flocculated in an aqueous medium to obtain flocculated particles 1. Furthermore, from the viewpoint of promoting flocculation, it is preferable to raise the temperature of the dispersion after adding the flocculant.

[0098] Methods for stopping coagulation include cooling the dispersion, adding a coagulation inhibitor, and diluting the dispersion. From the viewpoint of reliably preventing unnecessary coagulation, adding a coagulation inhibitor to stop coagulation is preferred.

[0099] [Flocculant inhibitor] As the flocculation inhibitor, surfactants are preferred, and anionic surfactants are more preferred. Examples of anionic surfactants include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, and polyoxyalkylene alkyl ether sulfates. One or more of these may be used. The flocculation inhibitor may be added in aqueous solution. From the viewpoint of reliably preventing unnecessary aggregation, the amount of flocculation inhibitor added is preferably 1 part by mass or more, more preferably 3 parts by mass or more, per 100 parts by mass of resin in the resin particles, and from the viewpoint of reducing residue in the toner, it is preferably 15 parts by mass or less, more preferably 12 parts by mass or less, and even more preferably 10 parts by mass or less.

[0100] Volume-intermediate particle size D of aggregated particle 1 50 The particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less.

[0101] Furthermore, in the present invention, after the step of agglomerating the resin particles and before the fusion step, there may be a step of agglomerating the shell resin particles, in which shell resin particles containing amorphous resin (preferably amorphous polyester resin) are attached to the obtained agglomerated particles 1 to obtain agglomerated particles 2. By including a step of agglomerating the shell resin particles, toner particles having a core-shell structure can be obtained. Here, the above-mentioned polyester resin (B) is an example of an amorphous resin used for the shell resin particles. The shell resin particles are obtained by the same method as the resin particles containing the amorphous resin and / or crystalline resin described above. Furthermore, if the toner manufacturing method includes a step of agglomerating resin particles for the shell, it is preferable to stop the agglomeration in this step when the agglomerated particles 2 have grown to a size appropriate for toner particles, and it is preferable to stop the agglomeration by adding the above-mentioned agglomeration inhibitor.

[0102] [Fusing process] In the fusion process, for example, aggregated particles are fused together in an aqueous medium. Fusion bonding fuses the individual particles contained within the aggregated particles, resulting in fused particles. In the fusion process, from the viewpoint of improving the fusion properties of the aggregated particles and achieving both low-temperature fixation and heat-resistant storage properties of the toner, the particles are held at a temperature above the glass transition temperature of the resin with the highest glass transition temperature among the resins contained in the aggregated particles. The holding temperature for fusing the aggregated particles is preferably 5°C higher, more preferably 10°C higher, and even more preferably 15°C higher than the glass transition temperature of the resin, from the viewpoint of improving the fusion properties of the aggregated particles and improving the productivity of the toner. Furthermore, it is preferably 40°C higher or lower, more preferably 35°C higher or lower, and even more preferably 33°C higher or lower than the glass transition temperature of the resin. In this case, the time for holding the resin at a temperature above its glass transition temperature 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, and even more preferably 90 minutes or less, from the viewpoint of achieving both low-temperature fixability and heat-resistant storage of the toner. Furthermore, it is preferable to maintain the temperature mentioned above until the desired degree of circularity is achieved.

[0103] Volume median particle size D of fused particles obtained by fusion 50 The particle size is preferably 2 μm or more, more preferably 3 μm or more, even more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less.

[0104] The circularity of the fused particles obtained by fusion is preferably 0.955 or higher, more preferably 0.960 or higher, and more preferably 0.990 or lower, more preferably 0.985 or lower, and even more preferably 0.980 or lower. It is preferable to terminate the fusion process after achieving the desired degree of circularity described above. The roundness is measured by the method described in the examples.

[0105] [Post-processing steps] A post-processing step may be performed after the fusion step, and toner particles can be obtained by isolating the fused particles. Since the fused particles obtained in the fusion step are present in an aqueous medium, it is preferable to first perform solid-liquid separation. Suction filtration or the like is preferably used for solid-liquid separation. It is preferable to perform washing after solid-liquid separation. At this time, it is also preferable to remove the added surfactant, so it is preferable to wash with an aqueous medium at a temperature below the cloud point of the surfactant. It is preferable to perform washing multiple times. Next, drying is preferable. Examples of drying methods include vacuum low-temperature drying, vibratory fluidized bed drying, spray drying, freeze drying, and flash jet drying.

[0106] [Toner particles] Volume-intermediate particle size D of toner particles 50 From the viewpoint of obtaining a toner with excellent low-temperature fixing properties and a narrow charge distribution, and from the viewpoint of 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 preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less.

[0107] From the viewpoint of obtaining high-quality images, the circularity of the toner particles is preferably 0.955 or higher, more preferably 0.960 or higher, and from the viewpoint of cleanability, it is preferably 0.990 or lower, more preferably 0.985 or lower, and even more preferably 0.980 or lower.

[0108] From the viewpoint of improving toner productivity, the CV value of the toner particles is preferably 10% or more, more preferably 15% or more, still more preferably 20% or more, and from the viewpoint of obtaining high-quality images, it is preferably 40% or less, more preferably 35% or less, still more preferably 30% or less. Volume-median particle diameter D of toner particles 50 can be measured by the method described in the Examples.

[0109] [Toner for developing electrostatic charge images] The toner for developing electrostatic charge images of the present invention contains toner particles. Although the toner particles can be used directly as a toner, it is preferable to use a product obtained by externally adding an external additive such as a fluidizing agent to the surface of the toner particles as the toner.

[0110] [External Additive] Examples of the external additive include fine particles of inorganic materials such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. The external additive may be used alone in one kind, or two or more kinds may be used. Further, two or more kinds of hydrophobic silica having different particle diameters may be used. When the surface treatment of toner particles is performed using an external additive, the addition amount of the external additive is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still 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, still more preferably 4 parts by mass or less, relative to 100 parts by mass of the toner particles.

[0111] The toner is used for electrostatic charge image development in electrophotographic printing. The toner can be used, for example, as a one-component developer, or mixed with a carrier to be used as a two-component developer.

Examples

[0112] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. Each property value was measured and evaluated by the following method. In notations such as "alkylene oxide (X)," the number X in parentheses represents the average number of moles of alkylene oxide added.

[0113] [Measurement method] The properties of polyester resin, resin particles, toner, etc., were measured and evaluated using the following method. [Softening point, crystallinity index, melting point, and glass transition temperature of resins] (1) Softening point Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample was heated at a heating rate of 6°C / min while a load of 1.96 MPa was applied by a plunger, and the sample was extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of plunger descent of the flow tester was plotted against temperature, and the temperature at which half of the sample flowed out was defined as the softening point. (2) Crystallinity index Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan and cooled to 0°C at a cooling rate of 10°C / min. The sample was then left to stand still for 1 minute, and then heated to 180°C at a heating rate of 10°C / min, and the amount of heat was measured. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was defined as the maximum endothermic peak temperature (1), and the crystallinity index was determined by (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)). (3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then cooled to 0°C at a rate of 10°C / min. The sample was then heated again at a rate of 10°C / min, and the amount of heat was measured. Among the observed endothermic peaks, the temperature of the peak with the largest peak area was defined as the maximum endothermic peak temperature (2). In the case of crystalline resins, this peak temperature was defined as the melting point. Furthermore, in the case of amorphous resins, if a peak was observed, the temperature of that peak was defined as the glass transition temperature. If no peak was observed but a step was observed, the temperature at the intersection of the tangent line showing the maximum slope of the curve in the step portion and the extension of the baseline on the low-temperature side of the step was defined as the glass transition temperature.

[0114] [Acid value of resins] The acid value of the resin was measured according to the neutralization titration method described in JIS K 0070:1992. However, the measurement solvent was a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0115] [Melting point of release agent] Using a differential scanning calorimeter "Q100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. Next, the sample was heated again at a rate of 10°C / min, the amount of heat was measured, and the maximum peak temperature of endothermic reaction was defined as the melting point.

[0116] [Volume median particle size D of resin particles, colorant particles, and mold release agent particles] 50 [and CV value] (1) Measuring device: Laser diffraction particle size analyzer "LA-920" (manufactured by Horiba, Ltd.) (2) Measurement conditions: Take the sample dispersion into a measuring cell, add distilled water, and adjust the concentration to the appropriate range for absorbance, using a volume-average particle size D. 50 The volume-average particle size Dv was also measured. Furthermore, the CV value was calculated according to the following formula. CV value (%) = (Standard deviation of particle size distribution / Volume-average particle size Dv) × 100

[0117] [Solid content concentration of resin particle dispersion, colorant particle dispersion, and mold release agent particle dispersion] Using an infrared moisture meter "FD-230" (manufactured by Kett Scientific Research Institute Co., Ltd.), the moisture content (mass%) of a 5g sample was measured at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, moisture content fluctuation range 0.05%). The solid content concentration was calculated according to the following formula. Solid concentration (mass%) = 100-moisture (mass%)

[0118] [Volume-intermediate particle size D of aggregated particles] 50 ] Volume-intermediate particle size D of aggregated particles 50 The following measurements were taken: • Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 50 μm • Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte solution to adjust the concentration so that the particle size of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured again, and the volume median particle size D was determined from the particle size distribution. 50 They sought it.

[0119] [Circularity of fused particles] The circularity of the fused particles was measured under the following conditions. • Measurement device: Flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) • Preparation of dispersion: The dispersion of fused particles was prepared by diluting it with deionized water to a solid content concentration of 0.001 to 0.05% by mass. • Measurement mode: HPF measurement mode

[0120] [Toner particle volume median particle size D] 50 [and CV value] Volume-intermediate particle size D of toner particles 50 The following measurements were taken: The measuring device, aperture diameter, analysis software, and electrolyte are the volume median particle size D of the aggregated particles as described above. 50 The same equipment used in the measurement was employed. • Dispersion: Polyoxyethylene lauryl ether "Emulgen® 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) was dissolved in the electrolyte to obtain a dispersion with a concentration of 5% by mass. • Dispersion conditions: 10 mg of the measurement sample of dried toner particles was added to 5 mL of the dispersion, dispersed for 1 minute using an ultrasonic disperser, then 25 mL of the electrolyte was added, and dispersed for another minute using an ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration to a level that allows for the measurement of 30,000 particle sizes in 20 seconds. Then, 30,000 particles are measured, and the volume median particle size D is determined from the particle size distribution. 50 and volume-average particle size D V They sought it. Furthermore, the CV value (%) was calculated according to the following formula. CV value (%) = (Standard deviation of particle size distribution / Volume average particle size D) V ) × 100

[0121] [Weight-average molecular weight of addition polymers] The solutions prepared by dissolving phosphoric acid and lithium bromide in N,N-dimethylformamide at concentrations of 60 mmol / L and 50 mmol / L, respectively, were used as eluents. The results were measured using gel permeation chromatography (GPC instrument "HLC-8320GPC" (Tosoh Corporation), columns "TSKgel SuperAWM-H", "TSKgel SuperAW3000", "TSKgel guardcolum Super AW-H" (Tosoh Corporation), flow rate: 0.5 mL / min) and monodisperse polystyrene kits with known molecular weights as standard substances (PStQuick B (F-550, F-80, F-10, F-1, A-1000), PStQuick C (F-288, F-40, F-4, A-5000, A-500), Tosoh Corporation) as the eluents.

[0122] [Resin manufacturing] [Manufacturing of amorphous polyester resin (A)] Manufacturing Example A1 (Manufacturing of Resin A-1) The raw material monomers for polyester resins other than fumaric acid, and the esterification catalyst shown in Table 1, were placed in a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube fitted with a fractionation tube through which 98°C hot water was passed, a stirrer, and a thermocouple. Under a nitrogen atmosphere, the reaction system was kept warm at 180°C for 1 hour, then the temperature was increased from 180°C to 230°C at 10°C / h, and then held at 230°C for 5 hours to allow polycondensation. After cooling to 180°C, 5 g of fumaric acid and a radical polymerization inhibitor (4-tert-butylcatechol) were added to the reaction system, the temperature was increased from 180°C to 210°C at 10°C / h, and the reaction was carried out at 210°C for 1 hour. The reaction was then carried out at 210°C and 10 kPa until the softening point shown in Table 1 was reached to obtain resin A-1. The physical properties are shown in Table 1.

[0123] Manufacturing examples A2 and A4 (Manufacturing of resins A-2 and A-4) Resins A-2 and A-4 were obtained in the same manner as in manufacturing example A1, except that the raw material monomers for the polyester resin were changed as shown in Table 1. The physical properties are shown in Table 1.

[0124] Manufacturing example A3 (Manufacturing of resin A-3) The raw material monomers for polyester resins other than isophthalic acid, and the esterification catalyst, as shown in Table 1, were placed in a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube fitted with a fractionation tube through which 98°C hot water was passed, a stirrer, and a thermocouple. Under a nitrogen atmosphere, the reaction system was kept warm at 180°C for 1 hour, then the temperature was increased from 180°C to 230°C at 10°C / h, and then held at 230°C for 5 hours to allow polycondensation. After cooling to 180°C, isophthalic acid was added to the reaction system, the temperature was increased from 180°C to 230°C at 10°C / h, and the reaction was carried out at 230°C for 1 hour. The reaction was then carried out at 230°C and 10 kPa until the softening point shown in Table 1 was reached to obtain resin A-3. The physical properties are shown in Table 1.

[0125] Manufacturing example A5 (Manufacturing of resin A-5) The raw material monomers, esterification catalysts, and esterification co-catalysts for polyester resins other than isophthalic acid, as shown in Table 1, were placed in a 10 L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple. Under a nitrogen atmosphere, the reaction system was kept warm at 205°C for 1 hour, then the temperature was increased from 205°C to 235°C at 10°C / h, and then held at 235°C for 5 hours to allow polycondensation. After cooling to 180°C, isophthalic acid was added to the reaction system, the temperature was increased from 180°C to 230°C at 10°C / h, and the reaction was carried out at 230°C for 1 hour. The reaction was then carried out at 230°C and 10 kPa until the softening point shown in Table 1 was reached to obtain resin A-5. The physical properties are shown in Table 1.

[0126] [Table 1]

[0127] [Manufacturing of crystalline polyester resin (C)] Manufacturing example C1 (Manufacturing of resin C-1) A 10L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen, and the raw material monomers for the polyester resin shown in Table 2 were added. While stirring the reaction system, the temperature was raised to 135°C and held at 135°C for 3 hours, and then the temperature was raised from 135°C to 200°C over 10 hours. Subsequently, 10g of tin(II) di(2-ethylhexanoate) was added to the reaction system, and the temperature was further raised to 200°C for 1 hour. Then, the pressure inside the flask was reduced to 8kPa and held under reduced pressure for 1 hour to obtain resin C-1, a crystalline polyester resin. The physical properties are shown in Table 2.

[0128] Manufacturing Examples C2-C6 (Manufacturing of resins C-2-C-6) Resins C-2 to C-6 were obtained in the same manner as in production example C1, except that the raw material monomers for the polyester resin were changed as shown in Table 2. The physical properties are shown in Table 2.

[0129] [Table 2]

[0130] [Manufacturing of resin particle dispersions] Manufacturing Example X1 (Manufacturing of Resin Particle Dispersion X-1) In a 3L container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, 160g of resin A-1, 40g of resin C-1, and 200g of methyl ethyl ketone were placed and dissolved at 73°C for 2 hours. To the resulting solution, a 5% by mass aqueous sodium hydroxide solution was added to achieve a degree of neutralization of 60 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes with stirring at 200 r / min to induce phase inversion emulsification. The resulting solution was then maintained at 73°C, and methyl ethyl ketone was removed under reduced pressure to obtain a dispersion. Subsequently, the dispersion was cooled to 30°C while continuing to stir, and then deionized water was added to achieve a solid content concentration of 20% by mass to obtain resin particle dispersion X-1. The physical properties are shown in Table 3.

[0131] Manufacturing Examples X2~X10 (Manufacturing of resin particle dispersions X-2~X-10) Resin particle dispersions X-2 to X-10 were obtained in the same manner as in manufacturing example X1, except that the resin was changed as shown in Table 3. The physical properties are shown in Table 3.

[0132] [Table 3]

[0133] [Manufacturing of composite resin (D)] Manufacturing example D1 (Manufacturing of resin D-1) A 10L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 4,313g of bisphenol A propylene oxide (2.2) adduct, 818g of terephthalic acid, 30g of tin(II) di(2-ethylhexanoate), and 3.0g of gallic acid were added. Under a nitrogen atmosphere, the reaction system was stirred and heated to 235°C, where it was maintained for 5 hours. After that, the pressure inside the flask was reduced and maintained at 8kPa for 1 hour. After returning to atmospheric pressure, it was cooled to 160°C and maintained at 160°C. A mixture of 2,756g of styrene, 689g of stearyl methacrylate, 142g of acrylic acid, and 413g of dibutyl peroxide was added dropwise to the reaction system over 1 hour. The reaction system was then maintained at 160°C for 30 minutes, then the temperature was raised to 200°C, and the pressure in the flask was further reduced to 8 kPa and maintained for 1 hour. After returning to atmospheric pressure, it was cooled to 190°C, 727 g of succinic acid was added, the temperature was raised to 210°C at 10°C / h, and then the reaction was carried out at 4 kPa until the desired softening point was reached to obtain resin D-1. The physical properties are shown in Table 4.

[0134] [Table 4]

[0135] Manufacturing Example S1 (Manufacturing of Resin Particle Dispersion S-1) In a 3L container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, 200g of resin D-1 and 200g of methyl ethyl ketone were placed and dissolved at 73°C for 2 hours. To the resulting solution, a 5% by mass aqueous sodium hydroxide solution was added to achieve a degree of neutralization of 60 mol% relative to the acid value of resin D-1, and the mixture was stirred for 30 minutes. Next, while maintaining the temperature at 73°C, 700 g of deionized water was added over 50 minutes while stirring at 280 r / min to induce phase inversion emulsification. The resulting solution was then maintained at 73°C, and methyl ethyl ketone was removed under reduced pressure to obtain an aqueous dispersion. Subsequently, the aqueous dispersion was cooled to 30°C while stirring at 280 r / min, and then deionized water was added to achieve a solid content concentration of 20% by mass to obtain resin particle dispersion S-1. The physical properties are shown in Table 5.

[0136] [Table 5]

[0137] [Manufacturing of mold release agent particle dispersion] Manufacturing Example W1 (Manufacturing of Release Agent Particle Dispersion W-1) In a 1L beaker, 120g of deionized water, 86g of resin particle dispersion S-1, and 40g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75℃) were added, and the mixture was stirred while maintaining a temperature of 90-95℃ to melt it, obtaining a molten mixture. The obtained molten mixture was subjected to dispersion treatment for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.) while maintaining its temperature at 90-95°C, and then cooled to room temperature (20°C). Deionized water was added to the obtained dispersion to adjust the solid content concentration to 20% by mass, thereby obtaining release agent particle dispersion W-1. The physical properties of the release agent particles in release agent particle dispersion W-1 are shown in Table 6.

[0138] Manufacturing example W2 (Manufacturing of release agent particle dispersion W-2) In manufacturing example W1, the mold release agent particle dispersion W-2 was obtained in the same manner, except that the type of mold release agent was changed to Fischer-Tropsch wax "FNP-0090" (manufactured by Nippon Seiro Co., Ltd., melting point 90°C) as shown in Table 6. The physical properties of the mold release agent particles in the mold release agent particle dispersion W-2 are shown in Table 6.

[0139] [Table 6]

[0140] [Production of addition polymers (E)] Manufacturing Example E1 (Synthesis of Addition Polymer E-1) The types and quantities of raw material monomers shown in Table 7 were mixed to prepare a monomer mixture with a total monomer content of 100 g. A four-necked flask equipped with a nitrogen inlet tube, dropping funnel, stirrer, and thermocouple was purged with nitrogen, and 18 g of methyl ethyl ketone, 0.03 g of 2-mercaptoethanol, and 10% by mass of the monomer mixture were added. The mixture was heated to 75°C while stirring. While maintaining the reaction system at 75°C, 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.) were added dropwise to the reaction system over 3 hours using a dropping funnel. After the addition was complete, the reaction system was maintained at 75°C for 2 hours. Then, a solution of 3 g of V-65 dissolved in 5 g of methyl ethyl ketone was added, and the system was maintained at 75°C for 2 hours and then at 80°C for 2 hours. Subsequently, the methyl ethyl ketone was removed by distillation under reduced pressure to obtain addition polymer E-1. Table 7 shows the weight-average molecular weight of the obtained addition polymers.

[0141] [Table 7]

[0142] [Manufacturing of colorant particle dispersion] Manufacturing Example Z1 (Manufacturing of Colorant Particle Dispersion Z-1) In a 5L container equipped with a stirrer with a disperser blade, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube, 75g of addition polymer E-1 and 630g of methyl ethyl ketone were added and the resin was dissolved at 20°C. To the resulting solution, 101g of 5% by mass aqueous sodium hydroxide solution (an amount that neutralizes addition polymer E-1 to 91 mol%) was added, followed by 955g of deionized water, and the mixture was stirred with a disperser blade at 2000 r / min at 20°C for 10 minutes. Next, 300g of Pigment Yellow 155 (Toner Yellow 3GP-CT, molecular weight 717, manufactured by Clariant Chemicals Co., Ltd.) was added, and the mixture was stirred at 6400 r / min with a disperser blade at 20°C for 2 hours. After that, it was passed through a 200-mesh filter and subjected to 15 passes at a pressure of 150 MPa using a homogenizer "Microfluidizer M-110EH" (manufactured by Microfluidics). The resulting dispersion was stirred and methyl ethyl ketone and some water were removed under reduced pressure at 70°C. After cooling, it was passed through a 200-mesh filter, and deionized water was added to obtain a colorant particle dispersion Z-1 by reducing the solid content to 20% by mass. The median particle size D of the colorant particles in the obtained aqueous dispersion Z-1 50 The particle size was 0.10 μm, and the CV value was 28%.

[0143] [Toner manufacturing] Example 1 (Manufacturing of Toner 1) In a 3L four-necked flask equipped with a dehydration tube, a stirrer, and a thermocouple, 500g of resin particle dispersion X-1, 49g of release agent particle dispersion W-1, 49g of release agent particle dispersion W-2, 63g of coloring agent particle dispersion Z-1, and 3.3g of 15% by mass sodium dodecylbenzenesulfonate aqueous solution "Neoperex G-15" (manufactured by Kao Corporation, anionic surfactant) were added and mixed at a temperature of 25°C. Next, while stirring the mixture, a solution prepared by dissolving 43g of ammonium sulfate in 980g of deionized water and adding a 4.8% by mass potassium hydroxide aqueous solution to adjust the pH to 8.2 was added dropwise over 10 minutes at 25°C, and the temperature was raised to 58°C over 2 hours to determine the volume-median particle size D of the aggregated particles. 50 The mixture was maintained at 58°C until it reached a size of 6.2 μm, and a dispersion of aggregated particles 1 was obtained. To the resulting dispersion of aggregated particles 1, 22 g of polyoxyethylene lauryl ether sodium sulfate "Emal E-27C" (manufactured by Kao Corporation, anionic surfactant, effective concentration 27% by mass) and 1100 g of deionized water were added. The mixture was then heated to 78°C over 1 hour and maintained at 78°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles in which the aggregated particles 1 had fused together. The resulting dispersion of fused particles was cooled to 30°C, and the dispersion was filtered by suction to separate the solid components. The mixture was then washed with deionized water at 25°C and filtered by suction at 25°C for 2 hours. Subsequently, toner particles were obtained by vacuum drying at 33°C for 24 hours using a vacuum constant-temperature dryer "DRV622DA" (manufactured by ADVANTEC). 100 parts by mass of toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.04 μm), and 1.0 part by mass of hydrophobic silica "Cabosil® TS720" (manufactured by Cabot Japan Co., Ltd., average particle size: 0.012 μm) were placed in a Henschel mixer and stirred. The mixture was then passed through a 150-mesh sieve to obtain toner 1. The physical properties of the toner particles are shown in Table 8.

[0144] [Toner evaluation] The low-temperature fixability and charge distribution of the obtained toner were evaluated as follows. [Low temperature retention] Using high-quality paper "J Paper A4 size" (manufactured by Fuji Xerox Co., Ltd.) and a commercially available printer "Microline® 5400" (manufactured by Oki Electric Industry Co., Ltd.), the amount of toner adhering to the paper was 0.60 ± 0.01 mg / cm². 2 The resulting solid image was printed on A4 paper, leaving a 5mm margin at the top edge, and extending to a length of 50mm without being fixed. Next, a modified version of the printer with a variable-temperature fuser was prepared. The fuser temperature was set to 100°C, and toner was fixed at a speed of 0.9 seconds per sheet in the A4 portrait direction to obtain a printed document. Using a similar method, the fuser temperature was increased by 5°C increments to fix the toner and obtain printed materials. From the top margin of the printed image to the solid image, lightly attach a 50mm length of Scotch® Mending Tape 810 (manufactured by Sumitomo 3M Co., Ltd., 18mm wide) and then place a 500g weight (contact area 1963mm²) on top. 2A sample was placed on top and pressed back and forth once at a speed of 10 mm / s. Then, the attached tape was peeled off from the bottom end at a peeling angle of 180° and a speed of 10 mm / s to obtain the printed material after tape removal. Thirty sheets of high-quality paper, "Excellent White Paper A4 size" (manufactured by OKI Electric Industry Co., Ltd.), were placed under the printed material before and after tape application. The reflected image density of the fixed image portion of each printed material before and after tape application was measured using a colorimeter "SpectroEye" (manufactured by Gretag Macbeth, light emission conditions: standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard), and the fixing rate was calculated from each reflected image density according to the following formula. Fixation rate (%) = (Reflective image density after tape removal / Reflective image density before tape application) × 100 The lowest temperature at which the fixing rate exceeds 90% was defined as the minimum fixing temperature T1. A lower minimum fixing temperature indicates better low-temperature fixing performance.

[0145] [Toner charge distribution] 0.6g toner and ferrite carrier (ferrite core, silicone coating, saturation magnetization: 71Am) 2 19.4 g (1 / kg) was placed in a 50 mL polypropylene bottle, "PP Sample Bottle Wide Mouth" (manufactured by Sanplatec Co., Ltd.), stirred in a ball mill for 20 minutes, and then 5 g was taken and measured using a charge meter "q-test" (manufactured by Epping Co., Ltd.) under the following measurement conditions. Toner Flow (mL / min): 160 Electrode Voltage (V): 4000 Deposition Time(s): 2 The median q / d was defined as the toner charge amount Q / d (fC / 10μm). The specific density was set to 1.2 g / cm³. 3 The Median Diameter is the volume-intermediate particle size (D) of the toner. 50 The value of ) was adopted. A graph of the charge distribution was created by connecting the obtained Q / d values ​​in the range of -0.4 to 0.4 (fC / 10μm) with a straight line. The charge distribution was evaluated by the width at half maximum (FWHM) of the maximum peak in the obtained graph (the width of the cross-section when the distribution is cut at half the height of the maximum peak in the distribution). A smaller value indicates a narrower charge distribution and better charge stability. The evaluation results are shown in Table 8.

[0146] Examples 2-3, 8 and Comparative Example 2 (Manufacturing of Toners 2-3, 8 and 10) In Example 1, toner was obtained in the same manner as in Example 1, except that the resin particle dispersion was changed to the aqueous dispersion shown in Table 8. Similar to Example 1, the low-temperature fixability and charge distribution of toners 2-3, 8, and 10 were also measured. The physical properties and evaluation results of the toners are shown in Table 8.

[0147] Example 4 (Manufacturing of Toner 4) In Example 1, the resin particle dispersion was changed to the aqueous dispersion shown in Table 8, and toner 4 was obtained in the same manner as in Example 1, except that the temperature was raised to 87°C over 1 hour to fuse the aggregated particles 1, and the temperature was held at 87°C until the circularity reached 0.970. In the same manner as in Example 1, the low-temperature fixability and the charge distribution of toner were measured for toner 4. The physical properties and evaluation results of the toner are shown in Table 8.

[0148] Example 5 (Manufacturing of Toner 5) In Example 1, the resin particle dispersion was changed to the aqueous dispersion shown in Table 8, and toner 5 was obtained in the same manner as in Example 1, except that the temperature was raised to 91°C over 1 hour to fuse the aggregated particles 1, and the temperature was held at 91°C until the circularity reached 0.970. In the same manner as in Example 1, the low-temperature fixability and the charge distribution of toner were measured for toner 5. The physical properties and evaluation results of the toner are shown in Table 8.

[0149] Examples 6-7 (Manufacturing of toners 6-7) In Example 1, the resin particle dispersion was changed to the aqueous dispersion shown in Table 8, and toners 6 and 7 were obtained in the same manner as in Example 1, except that the temperature was raised to 77°C over 1 hour to fuse the aggregated particles 1, and the temperature was maintained at 77°C until the circularity reached 0.970. In the same manner as in Example 1, the low-temperature fixability and the charge distribution of the toner were measured for toners 6 and 7. The physical properties and evaluation results of the toners are shown in Table 8.

[0150] Comparative Example 1 (Manufacturing of Toner 9) In Example 1, the resin particle dispersion was changed to the aqueous dispersion shown in Table 8, and toner 9 was obtained in the same manner as in Example 1, except that the temperature was raised to 74°C over 1 hour to fuse the aggregated particles 1, and the temperature was maintained at 74°C until the circularity was 0.970. In the same manner as in Example 1, the low-temperature fixability and the charge distribution of toner were measured for toner 9. The physical properties and evaluation results of the toner are shown in Table 8.

[0151] [Table 8]

[0152] As shown in Table 8, the present invention provides a manufacturing method that includes a step of agglomerating and fusing resin particles containing an amorphous polyester resin (A), which is a polycondensate of an alcohol component (a) containing an aliphatic diol with 2 to 5 carbon atoms and a carboxylic acid component (b), and a crystalline polyester resin (C), which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d), in an aqueous medium. This method yields toners 1 to 8 that exhibit excellent low-temperature fixability and a narrow charge distribution. On the other hand, in toner 9, since the alcohol component (c) is 1,6-hexanediol, the resin (C) could not be present near the surface of the toner during the aggregation and fusion processes, which is thought to have resulted in a relatively high fixing temperature. Furthermore, in toner 10, the hydrophilicity of resin (A), which is an alkylene oxide (2.2) adduct of bisphenol A, was insufficient, which is thought to have prevented the exposure of resin (C) to the surface of the fused particles from being suppressed, resulting in a wider charge distribution.

Claims

1. A method for manufacturing toner for electrostatic image developing, comprising the steps of agglomerating and fusing resin particles containing amorphous resin and crystalline resin in the same or different particles in an aqueous medium, The amorphous resin contains an amorphous polyester resin (A) which is a polycondensate of an alcohol component (a) containing an aliphatic diol having 2 to 5 carbon atoms and a carboxylic acid component (b), The aliphatic diol contains at least one selected from 1,2-propanediol, 2,3-butanediol, and neopentyl glycol. The crystalline resin contains a crystalline polyester resin (C) which is a polycondensate of an alcohol component (c) containing ethylene glycol and a carboxylic acid component (d), The mass ratio of the crystalline polyester resin (C) to the amorphous polyester resin (A) [crystalline polyester resin (C) / amorphous polyester resin (A)] is 5 / 95 or more and 40 / 60 or less. A method for manufacturing toner for developing electrostatic images.

2. The method for producing electrostatic image developing toner according to claim 1, wherein the content of the aliphatic diol having 2 to 5 carbon atoms in the alcohol component (a) is 85 mol% to 100 mol%.

3. The method for producing electrostatic image developing toner according to claim 1, wherein the carboxylic acid component (b) contains at least one selected from terephthalic acid and isophthalic acid.

4. The method for producing a toner for electrostatic image development according to claim 3, wherein the carboxylic acid component (b) further contains fumaric acid.

5. The method for producing electrostatic image developing toner according to claim 1, wherein the content of ethylene glycol in the alcohol component (c) is 80 mol% or more and 100 mol% or less.

6. The method for producing a toner for electrostatic image developing according to claim 1, wherein the carboxylic acid component (d) includes an aliphatic dicarboxylic acid.

7. The method for producing a toner for electrostatic image development according to claim 6, wherein the aliphatic dicarboxylic acid contains at least one selected from sebaciic acid, dodecanediic acid, and tetradecanediic acid.

8. A method for producing a toner for electrostatic image developing according to claim 6, wherein the amount of aliphatic dicarboxylic acid is 80 mol% or more and 100 mol% or less in the carboxylic acid component (d).

9. The method for producing a toner for electrostatic image development according to claim 1, wherein the carboxylic acid component (d) contains a monovalent carboxylic acid.

10. A method for producing electrostatic image developing toner according to any one of claims 1 to 9, comprising further agglomerating at least one of the coloring agent and the mold release agent in the agglomeration step.

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