Method for producing a dispersion of resin particles for toner

Abstract

The present invention provides a method for producing a toner resin particle dispersion liquid capable of obtaining a toner having more excellent low-temperature fixing property. The method for producing a toner resin particle dispersion liquid of the present invention has a step of cooling by continuously mixing a resin particle dispersion liquid containing an amorphous resin and a crystalline resin with an aqueous medium while flowing.

Description

Technical Field

[0001] The present invention relates to a method for producing a toner resin particle dispersion, and more particularly to a method for producing a toner resin particle dispersion used in electrophotographic toners used in electrophotography, electrostatic recording, electrostatic printing, and the like. Background Art

[0002] In the field of electrophotographic toners, the development of electrophotographic systems has led to a demand for toners that support higher image quality and faster processing speeds. To achieve this, toner particle size reduction is required, leading to the development of so-called chemical toners, which utilize chemical methods such as polymerization and emulsion dispersion, replacing the conventional melt-kneading method. Chemical toner production typically involves heating and stirring an aqueous dispersion of resin particles and a coagulant to aggregate and fuse the particles, followed by cooling.

[0003] For example, in Japanese Patent Publication No. 2018-22132 (Patent Document 1), a method for producing a colorant for electrostatic image development is disclosed, with the aim of obtaining a colorant having excellent low-temperature fixing properties and capable of suppressing the reduction of low-temperature fixing properties over time. The method includes a step of cooling a dispersion of colorant particles containing an amorphous resin (A) and a crystalline resin (B), wherein the cooling step satisfies specific temperature conditions.

[0004] In addition, in Japanese Patent Publication No. 2018-13589 (Patent Document 2), for the same problem as Patent Document 1, a method for producing a colorant for electrostatic image development is disclosed, which comprises a step (1): a step of agglomerating an amorphous composite resin and a crystalline resin in an aqueous medium to obtain a dispersion of agglomerated particles, a step (2): a step of fusing the obtained agglomerated particles to obtain a dispersion of fused particles, and a step (3): a step of cooling the obtained dispersion of fused particles at a rate of 10°C / min or higher, wherein the amorphous composite resin contains a polyester resin segment and a vinyl resin segment containing a structural unit derived from a vinyl monomer having a hydrocarbon group having 6 or more and 22 carbon atoms. Summary of the Invention

[0005] The present invention relates to the following [1] and [2].

[0006] [1] A method for producing a resin particle dispersion for toner, comprising the steps of flowing a resin particle dispersion containing an amorphous resin and a crystalline resin together with an aqueous medium, continuously mixing the mixture, and then cooling the mixture.

[0007] [2] A method for producing a toner for electrostatic image development, comprising the method described in [1]. DETAILED DESCRIPTION

[0008] In Patent Documents 1 and 2, since it is difficult to rapidly lower the temperature of the dispersion of fused particles of toner particles, the crystal domains derived from the crystalline resin in the toner particles tend to become larger.

[0009] The present invention provides a method for producing a resin particle dispersion for toner, which can obtain a toner having further excellent low-temperature fixing property.

[0010] The present invention has found that a resin particle dispersion for toner can be obtained by adopting a specific cooling step, and the resin particle dispersion for toner can provide a toner having excellent low-temperature fixing properties.

[0011] That is, the present invention relates to the above-mentioned [1] and [2].

[0012] According to the production method of the present invention, it is possible to obtain a resin particle dispersion for toner, which can produce a toner having excellent low-temperature fixing properties.

[0013] [Method for producing resin particle dispersion for toner]

[0014] The method for producing a resin particle dispersion for toner of the present invention includes a step of flowing a resin particle dispersion containing an amorphous resin (hereinafter also referred to as amorphous resin (A)) and a crystalline resin (hereinafter also referred to as crystalline resin (B)) with an aqueous medium, continuously mixing the mixture, and then cooling the mixture.

[0015] The resin particle dispersion containing (A) an amorphous resin and (B) a crystalline resin used in the present invention can be particles obtained by any of the conventionally known methods such as melt kneading, emulsification phase inversion, polymerization, and coacervation fusion, but particles based on the coacervation fusion method are preferred.

[0016] In the case of the coacervation fusion method, the manufacturing method includes, for example:

[0017] Step 1: A step of agglomerating the amorphous resin (A) and the crystalline resin (B) in an aqueous medium to obtain a dispersion of aggregated particles (hereinafter also referred to as "Step 1");

[0018] Step 2: a step of heating and fusing the obtained aggregated particles in an aqueous medium to obtain a dispersion of fused particles (resin particle dispersion) (hereinafter also referred to as "step 2"); and

[0019] Step 3: A step of obtaining a resin particle dispersion for toner by flowing the obtained resin particle dispersion containing the amorphous resin (A) and the crystalline resin (B) with an aqueous medium, continuously mixing the mixture, and cooling the mixture (hereinafter also referred to as "step 3").

[0020] In the method of adding a dispersion of fused particles of colorant particles to cold water, or adding cold water to a dispersion of fused particles of colorant particles, as described in Patent Documents 1 and 2, the temperature of the cold water or the above-mentioned dispersion slowly changes with the addition, so the size of the crystal domain fluctuates, resulting in particles with large crystal domains.

[0021] It is believed that structural defects are generated at the interface between the amorphous resin and the crystalline resin during toner fixing, promoting fixing. Therefore, it is believed that as the crystal domains of the crystalline resin increase in size, the interface area decreases, resulting in a decrease in the meltability of the crystalline resin during toner fixing, and a reduction in low-temperature fixing properties.

[0022] It is believed that in the present invention, since the resin particle dispersion containing the amorphous resin (A) and the crystalline resin (B) is allowed to flow together with the aqueous medium and continuously mixed and cooled, it is cooled in a short time, thereby suppressing the expansion of the crystal domains in the resin particles.

[0023] Furthermore, it is believed that since the temperature of the resin particle dispersion and the temperature of the aqueous medium to be mixed are constant, a toner resin particle dispersion of the same quality can be always obtained, and fluctuation in the size of crystal domains between the resin particles can be suppressed.

[0024] It is considered that, as a result, according to the production method of the present invention, a resin particle dispersion for toner having improved low-temperature fixing properties can be obtained.

[0025] <Process 1>

[0026] Step 1 is a step of agglomerating the amorphous resin (A) and the crystalline resin (B) in an aqueous medium to obtain a dispersion of aggregated particles.

[0027] The resin constituting the resin particles is not particularly limited as long as it can constitute an aqueous dispersion. However, from the viewpoint of low-temperature fixing ability and charging properties of the toner, a polyester resin is preferred.

[0028] That is, the resin particles contain an amorphous resin (A) and a crystalline resin (B), and preferably contain an amorphous polyester resin and a crystalline polyester resin.

[0029] Here, whether the resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined by the ratio of the softening point of the resin to the maximum peak temperature of heat absorption (softening point (°C) / maximum peak temperature of heat absorption (°C)) in the measurement method described in the examples described later. The so-called crystalline resin is a resin having a crystallinity index of 0.6 or more and 1.4 or less. The so-called amorphous resin is a resin having a crystallinity index of less than 0.6 or greater than 1.4. The crystallinity index can be appropriately adjusted using the types and ratios of the raw monomers, as well as manufacturing conditions such as reaction temperature, reaction time, and cooling rate.

[0030] (Amorphous resin (A))

[0031] From the perspective of obtaining a toner exhibiting low-temperature fixing properties, image density of printed materials, and hot offset resistance, the amorphous resin (A) is preferably a polyester resin, and more preferably a polyester resin comprising a component derived from a hydrocarbon wax W1 having at least one of a hydroxyl group and a carboxyl group, and a polyester resin segment. The amorphous resin (A) is preferably a resin obtained, for example, by polycondensing an alcohol component and a carboxylic acid component in the presence of a hydrocarbon wax W1 having at least one of a hydroxyl group and a carboxyl group.

[0032] For the amorphous resin (A), from the viewpoint of further improving low-temperature fixing property, image density of printed materials and hot offset resistance, it is more preferable to have a constituent component derived from a hydrocarbon wax W1 having at least one of a hydroxyl group and a carboxyl group, a polyester resin segment and an addition polymerization resin segment.

[0033] [Components derived from hydrocarbon wax W1]

[0034] The “constituents derived from the hydrocarbon wax W1” refer to residual components of the hydrocarbon wax W1 in which at least one of the hydroxyl group and the carboxyl group of the hydrocarbon wax has reacted and covalently bonded to the polyester resin segment.

[0035] The hydrocarbon wax W1 has at least one of a hydroxyl group and a carboxyl group. The hydrocarbon wax W1 may have either or both of a hydroxyl group and a carboxyl group. However, from the perspective of improving low-temperature fixing properties, image density of printed materials, and hot offset resistance, the hydrocarbon wax W1 preferably has a hydroxyl group and a carboxyl group.

[0036] The hydrocarbon wax W1 can be obtained, for example, by modifying an unmodified hydrocarbon wax using a known method. Examples of the raw materials for the hydrocarbon wax W1 include paraffin wax, Fischer-Tropsch wax, microcrystalline wax, polyethylene wax, and polypropylene wax. Among these, paraffin wax and Fischer-Tropsch wax are preferred.

[0037] Examples of commercially available paraffin wax and Fischer-Tropsch wax as raw materials for the hydrocarbon wax W1 include "HNP-11", "HNP-9", "HNP-10", "FT-0070", "HNP-51", and "FNP-0090" (all manufactured by Nippon Seiro Co., Ltd.).

[0038] Hydrocarbon waxes having hydroxyl groups are, for example, hydrocarbon waxes obtained by modifying hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax by oxidation. Examples of oxidation methods include those described in Japanese Patent Application Laid-Open No. 62-79267 and Japanese Patent Application Laid-Open No. 2010-197979. Specifically, a method in which a hydrocarbon wax is subjected to liquid-phase oxidation using an oxygen-containing gas in the presence of boric acid can be exemplified.

[0039] Examples of commercially available products of hydrocarbon waxes having a hydroxyl group include "Unilin 700," "Unilin 425," and "Unilin 550" (all manufactured by Baker Petrolite).

[0040] Examples of hydrocarbon waxes having a carboxyl group include acid-modified hydrocarbon waxes.

[0041] Acid-modified hydrocarbon waxes can be obtained, for example, by introducing carboxyl groups into hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax through acid modification. Examples of acid modification methods include those described in Japanese Patent Application Publication Nos. 2006-328388 and 2007-84787. Specifically, an organic peroxide such as dicumyl peroxide and a carboxylic acid compound having an unsaturated bond are added as reaction initiators to a melt of the hydrocarbon wax as a raw material, and the mixture is reacted to introduce carboxyl groups.

[0042] Examples of commercially available hydrocarbon waxes having a carboxyl group include a maleic anhydride-modified ethylene-propylene copolymer "HI-WAX 1105A" (manufactured by Mitsui Chemicals, Inc.).

[0043] The hydrocarbon wax having a hydroxyl group and a carboxyl group can be obtained, for example, by the same method as the oxidation treatment of the hydrocarbon wax having a hydroxyl group.

[0044] Examples of commercially available hydrocarbon waxes having a hydroxyl group and a carboxyl group include "Paracol 6420," "Paracol 6470," and "Paracol 6490" (all manufactured by Nippon Seiro Co., Ltd.).

[0045] 〔Polyester resin segment〕

[0046] The polyester resin segment is, for example, a segment containing a polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component.

[0047] Hereinafter, each component of the polyester resin segment of the amorphous resin (A) will be described.

[0048] Examples of the alcohol component include diols having an aromatic group, linear or branched aliphatic diols, alicyclic diols, and trivalent or higher polyols. Among these, aromatic diols are preferred.

[0049] The diol having an aromatic group is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of bisphenol A represented by formula (I):

[0050] [Chemistry 1]

[0051]

[0052] (Where R 1 O and OR 2 is an oxyalkylene group, R 1 and R 2 Each independently represents an ethylene group or a propylene group, x and y represent the average number of added moles of alkylene oxide, each being a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, more preferably 2 or more, and 16 or less, preferably 8 or less, more preferably 4 or less)

[0053] Examples of the alkylene oxide adducts of bisphenol A include polypropylene oxide adducts of bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and polyethylene oxide adducts of bisphenol A. It is preferred to use one or more of these.

[0054] The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol% or more, more preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and is 100 mol% or less, more preferably 100 mol%.

[0055] Examples of the carboxylic acid component include dicarboxylic acids and trivalent or higher-valent polycarboxylic acids.

[0056] Examples of the dicarboxylic acid include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids, among which at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferred.

[0057] Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred.

[0058] The amount of the aromatic dicarboxylic acid is preferably 20 mol% or more, more preferably 30 mol% or more, and even more preferably 40 mol% or more, and is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 80 mol% or less in the carboxylic acid component.

[0059] The carbon number of the linear or branched aliphatic dicarboxylic acid is preferably 2 or more, more preferably 3 or more, and is preferably 30 or less, more preferably 20 or less.

[0060] Examples of the linear or branched aliphatic dicarboxylic acid include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, and succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. Examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, fumaric acid and succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms are preferred, and fumaric acid is more preferred.

[0061] The amount of the linear or branched aliphatic dicarboxylic acid is preferably 1 mol% or more, more preferably 2 mol% or more, and even more preferably 3 mol% or more, and is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less in the carboxylic acid component.

[0062] As the trivalent or higher polycarboxylic acid, a trivalent carboxylic acid is preferred, and an example thereof is trimellitic acid.

[0063] When a polycarboxylic acid having a valence of 3 or more is included, the amount of the polycarboxylic acid having a valence of 3 or more is preferably 3 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, further preferably 20 mol% or less in the carboxylic acid component.

[0064] These carboxylic acid components can be used alone or in combination of two or more.

[0065] The ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0066] 〔Addition polymerization resin segment〕

[0067] The addition polymerization resin segment is preferably an addition polymer of a raw material monomer containing a styrene compound from the viewpoint of improving low-temperature fixing property and image density of printed matter.

[0068] Examples of the styrene-based compound include substituted or unsubstituted styrenes, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group or a salt thereof.

[0069] Examples of the styrene-based compound include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid or salts thereof, of which styrene is preferred.

[0070] The content of the styrene compound in the raw material vinyl monomer of the addition polymerization resin segment is preferably 40% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, further preferably 70% by mass or more, and is preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 87% by mass or less, further preferably 85% by mass or less, from the viewpoint of improving low-temperature fixing properties and image density of printed materials.

[0071] Examples of raw material monomers other than styrene compounds include (meth)acrylates such as alkyl (meth)acrylates, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylates are preferred, and alkyl (meth)acrylates are more preferred, from the perspective of improving low-temperature fixing properties and image density of printed materials, as well as improving hot offset resistance.

[0072] The number of carbon atoms in the alkyl group of (meth)acrylic acid is preferably 1 or more, more preferably 6 or more, even more preferably 10 or more, and is preferably 24 or less, more preferably 22 or less, even more preferably 20 or less, from the viewpoint of further improving low-temperature fixing property and image density of printed materials, and from the viewpoint of further improving hot offset resistance.

[0073] From the viewpoint of improving low-temperature fixing properties and image density of printed materials, the raw material monomers of the addition polymerization resin segment preferably contain styrene or styrene and a (meth)acrylate, more preferably contain styrene and a (meth)acrylate, and even more preferably contain styrene and an alkyl (meth)acrylate having an alkyl group having 6 to 20 carbon atoms.

[0074] The content of (meth)acrylate in the raw material vinyl 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 even more preferably 17% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, from the viewpoint of improving low-temperature fixing properties and image density of printed materials.

[0075] The total content of the styrene compound and the (meth)acrylate 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 is 100% by mass or less, and even more preferably 100% by mass, from the viewpoint of further improving the low-temperature fixing property and the image density of the printed matter.

[0076] When the amorphous resin (A) has an addition polymerization resin segment, the amorphous resin (A) preferably has a structural unit derived from a bireactive monomer covalently bonded to the polyester resin segment and the addition polymerization resin segment. The "structural unit derived from a bireactive monomer" refers to a unit in which the functional group or unsaturated bond site of the bireactive monomer has reacted.

[0077] Examples of the bireactive monomer include addition polymerizable monomers having at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, addition polymerizable monomers having a hydroxyl group or a carboxyl group are preferred, and addition polymerizable monomers having a carboxyl group are more preferred.

[0078] Examples of the bireactive monomer include acrylic acid, methacrylic acid, fumaric acid, maleic acid, etc. Among these, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred from the viewpoint of reactivity in both polycondensation reaction and addition polymerization reaction.

[0079] The amount of the structural unit derived from the bireactive monomer is preferably 1 mol part or more, more preferably 5 mol parts or more, and even more preferably 8 mol parts or more, and is preferably 30 mol parts or less, more preferably 25 mol parts or less, and even more preferably 20 mol parts or less, based on 100 mol parts of the alcohol component of the polyester resin segment of the amorphous resin (A).

[0080] The amount of the constituent components derived from the hydrocarbon wax W1 in the amorphous resin (A) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, and is preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of further improving the low-temperature fixing property and the image density of printed materials, as well as from the viewpoint of further improving the hot offset resistance.

[0081] The amount of the polyester resin segment in the amorphous resin (A) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and is preferably 99% by mass or less, more preferably 98% by mass or less, from the viewpoint of further improving the low-temperature fixing property and the image density of printed materials, and from the viewpoint of further improving the hot offset resistance. When the amorphous resin (A) contains an addition polymerization-based resin segment, the amount is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less.

[0082] The amount of the addition polymerization resin segment in the amorphous resin (A) is preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, further preferably 25% by mass or more, further preferably 35% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, further preferably 45% by mass or less, from the viewpoint of further improving the low-temperature fixing property and the image density of the printed matter.

[0083] The amount of the structural unit derived from the bireactive monomer in the amorphous resin (A) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 0.8% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

[0084] The total amount of the constituent components derived from the hydrocarbon wax W1, the polyester resin segment, the addition polymerization resin segment and the structural units derived from the bireactive monomer in the amorphous resin (A) is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 93% by mass or more, further preferably 95% by mass or more, and is 100% by mass or less.

[0085] The above amounts are calculated based on the ratio of the amounts of the polyester resin segment, the raw material monomers for the addition polymerization resin segment, the bireactive monomer, and the free radical polymerization initiator, and do not take into account the amount of dehydration caused by the polycondensation of the polyester resin segment, etc. It should be noted that when a free radical polymerization initiator is used, the mass of the free radical polymerization initiator is included in the calculation of the addition polymerization resin segment.

[0086] [Production of amorphous resin (A)]

[0087] The amorphous resin (A) can be obtained, for example, by polycondensation of an alcohol component and a carboxylic acid component in the presence of a hydrocarbon wax W1 having a hydroxyl group or a carboxyl group.

[0088] If necessary, polycondensation can be carried out using an esterification catalyst such as 0.01 part by mass or more and 5 parts by mass or less of tin (II) di(2-ethylhexanoate), dibutyltin oxide, or diisopropyl bis(triethanolamine)titanate, relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component; and an esterification co-catalyst such as 0.001 part by mass or more and 0.5 parts by mass or less of gallic acid (the same as 3,4,5-trihydroxybenzoic acid), relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0089] The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, more preferably 230° C. or lower. The polycondensation reaction may be performed in an inert gas atmosphere.

[0090] When the amorphous resin (A) has an addition polymerization resin chain segment, it can be manufactured, for example, in the presence of hydrocarbon wax W1, using a method comprising step A of a condensation reaction based on an alcohol component and a carboxylic acid component, and step B of an addition polymerization reaction based on a raw material monomer of the addition polymerization resin chain segment and a direactive monomer.

[0091] Step B may be performed after step A, step A may be performed after step B, or step A and step B may be performed simultaneously.

[0092] A more preferred method is to subject a portion of the carboxylic acid component to a polycondensation reaction in step A, then perform step B, raise the reaction temperature again, and add the remainder of the polycarboxylic acid component to the polymerization system to further advance the polycondensation reaction in step A and, if necessary, the reaction with the bireactive monomer.

[0093] [Physical properties of amorphous resin (A)]

[0094] The softening point of the amorphous resin (A) is preferably 70°C or higher, more preferably 90°C or higher, more preferably 100°C or higher, further preferably 110°C or higher, and is preferably 140°C or lower, more preferably 135°C or lower, further preferably 130°C or lower, from the viewpoint of further improving low-temperature fixing property and image density of printed materials, and further improving hot offset resistance.

[0095] The glass transition temperature of the amorphous resin (A) is preferably 30°C or higher, more preferably 35°C or higher, and even more preferably 40°C or higher, and is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower, from the viewpoint of further improving low-temperature fixing property and image density of printed materials, as well as further improving hot offset resistance.

[0096] The acid value of the amorphous resin (A) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and even more preferably 16 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, and even more preferably 30 mgKOH / g or less, from the viewpoint of further improving low-temperature fixing properties and image density of printed materials.

[0097] The softening point, glass transition temperature and acid value of the amorphous resin (A) can be appropriately adjusted by adjusting the types and ratios of the raw monomers, and production conditions such as reaction temperature, reaction time and cooling rate. These values ​​can also be determined by the methods described in the Examples.

[0098] In addition, when using two or more non-crystalline resins (A) as a mixture, it is preferable that the softening point, glass transition temperature, and acid value obtained as the mixture thereof are each within the above-mentioned range.

[0099] (Crystalline resin (B))

[0100] Examples of the crystalline resin (B) include crystalline polyester resins, which are polycondensates of an alcohol component and a carboxylic acid component.

[0101] As the alcohol component, α,ω-aliphatic diol is preferred. The carbon number of the α,ω-aliphatic diol is preferably 2 or more, more preferably 4 or more, and even more preferably 6 or more, and is preferably 16 or less, more preferably 14 or less, and even more preferably 12 or less. Examples of α,ω-aliphatic diols include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol. Among these, 1,6-hexanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred, and 1,10-decanediol is more preferred.

[0102] The amount of the α,ω-aliphatic diol in the alcohol component is preferably 80 mol% or more, more preferably 85 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and is 100 mol% or less, more preferably 100 mol%.

[0103] The alcohol component may contain another alcohol component other than the α,ω-aliphatic diol.

[0104] As the carboxylic acid component, an aliphatic dicarboxylic acid is preferred. The carbon number of the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, even more preferably 10 or more, and preferably 14 or less, more preferably 12 or less. Examples of aliphatic dicarboxylic acids include fumaric acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, sebacic acid and dodecanedioic acid are preferred, with sebacic acid being more preferred. These carboxylic acid components may be used alone or in combination of two or more.

[0105] The amount of the aliphatic dicarboxylic acid is preferably 80 mol% or more, more preferably 85 mol% or more, further preferably 90 mol% or more, further preferably 95 mol% or more, and is 100 mol% or less, more preferably 100 mol% or less, in the carboxylic acid component.

[0106] The carboxylic acid component may contain other carboxylic acid components other than the aliphatic dicarboxylic acid.

[0107] The ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0108] The crystalline resin (B) is obtained, for example, by polycondensation of an alcohol component and a carboxylic acid component. The conditions for the polycondensation reaction are the same as those described in the method for producing the amorphous resin (A).

[0109] [Physical properties of crystalline resin (B)]

[0110] The softening point of the crystalline resin (B) is preferably 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher from the viewpoint of improving low-temperature fixing properties and image density of printed materials, and is preferably 150°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower from the viewpoint of improving image density and hot offset resistance of printed materials.

[0111] The melting point of the crystalline resin (B) is preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 65°C or higher, from the viewpoint of improving low-temperature fixing properties and image density of printed materials, and is preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 80°C or lower.

[0112] The acid value of the crystalline resin (B) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and even more preferably 15 mgKOH / g or more, from the viewpoint of improving the dispersion stability of the resin particles (Y) described later, and is preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 25 mgKOH / g or less.

[0113] The softening point, melting point and acid value of the crystalline resin (B) can be appropriately adjusted by adjusting the types and ratios of the raw monomers, and production conditions such as reaction temperature, reaction time and cooling rate. These values ​​can also be determined by the methods described in the Examples.

[0114] In addition, when using crystalline resins (B) by mixing two or more types, it is preferable that the softening point, melting point, and acid value obtained as the mixture thereof are respectively within the above-mentioned ranges.

[0115] (Production of Crystalline Resin (B))

[0116] The crystalline resin (B) can be produced by a known method. For example, in the case of a crystalline polyester resin, it can be produced by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, optionally using an esterification catalyst, an esterification co-catalyst, a radical polymerization inhibitor, and the like.

[0117] As the esterification catalyst, esterification co-catalyst, and radical polymerization inhibitor, the same ones as those used in the production of the amorphous resin (A) can be used.

[0118] The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 5 parts by mass or less, more preferably 2 parts by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0119] The temperature of the polycondensation reaction is preferably 120°C or higher, more preferably 160°C or higher, and even more preferably 180°C or higher, and is preferably 250°C or lower, more preferably 230°C or lower, and even more preferably 220°C or lower.

[0120] (Water-based media)

[0121] The aqueous medium is preferably a medium containing water as a main component. From the perspective of improving the dispersion stability of the aqueous dispersion and from the perspective of environmental protection, the water content in the aqueous medium is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more and 100% by mass or less. The water is preferably deionized water, ion-exchanged water, or distilled water.

[0122] As components other than water that can constitute an aqueous medium together with water, organic solvents soluble in water such as alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran can be used.

[0123] Among them, methyl ethyl ketone is preferred.

[0124] (Conditions of process 1)

[0125] The process 1 preferably includes the following process 1-1, and may subsequently include the process 1-2 in order to obtain toner particles having a core-shell structure.

[0126] Step 1-1: A step of agglomerating resin particles (X) comprising an amorphous resin (A) and a crystalline resin (B) in an aqueous medium to obtain aggregated particles (1)

[0127] Step 1-2: Adding resin particles (Y) containing amorphous resin (C) to the aggregated particles (1) obtained in step 1-1 to obtain aggregated particles (2) in which the resin particles (Y) are attached to the aggregated particles (1)

[0128] It should be noted that, when step (1) includes step (1-1) and step (1-2), the “aggregated particles obtained” in step (2) refer to “aggregated particles (2) obtained in step (1-2)”. Furthermore, when step (1) includes only step (1-1), the “aggregated particles obtained” in step (2) refer to “aggregated particles (1) obtained in step (1-1)”.

[0129] (Process 1-1)

[0130] In step 1-1, in addition to the amorphous resin (A) and the crystalline resin (B), optional components such as wax (D), a colorant, a coagulant, and a surfactant may be coagulated in an aqueous medium as needed.

[0131] The resin particles (X) may be formed by agglomerating an aqueous dispersion of an amorphous resin (A) and an aqueous dispersion of a crystalline resin (B), or by agglomerating an aqueous dispersion of a mixed resin containing the amorphous resin (A) and the crystalline resin (B), without particular limitation.

[0132] [Resin particles (X)]

[0133] A resin component containing an amorphous resin (A) and a crystalline resin (B) and optional components such as a colorant used as needed (hereinafter, the resin component and optional components are collectively referred to as "resin component, etc.") are dispersed in an aqueous medium to obtain resin particles (X) as an aqueous dispersion.

[0134] Examples of methods for obtaining an aqueous dispersion of the resin particles (X) include a method of adding the resin component, etc. to an aqueous medium and dispersing the mixture using a disperser, etc., and a method of gradually adding the aqueous medium to a melt or an organic solvent solution of the resin component, etc. to effect phase inversion emulsification (phase inversion emulsification). Among these, the method using phase inversion emulsification is preferred from the viewpoints of excellent low-temperature fixing properties, suppression of deterioration of low-temperature fixing properties over time, and excellent heat-resistant storage properties.

[0135] Examples of the phase inversion emulsification method include method (a) of dissolving the resin component and the like in an organic solvent and adding an aqueous medium to the resulting solution to perform phase inversion emulsification, and method (b) of adding an aqueous medium to a resin mixture obtained by melting and mixing the resin component and the like to perform phase inversion emulsification. Method (a) is preferred from the viewpoint of obtaining a uniform aqueous dispersion of the resin particles (X).

[0136] Among the methods (a), a method is preferred in which the resin component and the like are first dissolved in an organic solvent to obtain an organic solvent solution of the resin component and the like, and then an aqueous medium is added to the solution to perform phase inversion emulsification.

[0137] The organic solvent used in the phase inversion emulsification method is preferably at least one selected from ketone solvents and acetate solvents, more preferably at least one selected from methyl ethyl ketone, ethyl acetate, and isopropyl acetate, and even more preferably methyl ethyl ketone.

[0138] The mass ratio of the organic solvent to the resin constituting the resin particles (X) (organic solvent / resin constituting the resin particles (X)) is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.4 or more, and is preferably 4 or less, more preferably 2 or less, and even more preferably 1.5 or less, from the viewpoint of facilitating dissolution of the resin and phase transition to the aqueous medium and improving the dispersion stability of the resin particles (X).

[0139] In the phase inversion emulsification method, the resin is preferably treated with a neutralizing agent.

[0140] Examples of the neutralizing agent include alkaline substances. Examples of the alkaline substance include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; and nitrogen-containing alkaline substances such as ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, diethanolamine, triethanolamine, and tributylamine. Among these, alkali metal hydroxides are preferred, and sodium hydroxide is more preferred, from the perspective of improving the dispersion stability and cohesion of the resin particles (X).

[0141] The usage equivalent (mol %) of the neutralizing agent relative to the acid groups of the resin is preferably 10 mol % or more, more preferably 30 mol % or more, and preferably 150 mol % or less, more preferably 120 mol % or less, and further preferably 100 mol % or less.

[0142] It should be noted that the usage equivalent amount (mol %) of the neutralizing agent can be calculated using the following formula: When the usage equivalent amount of the neutralizing agent is 100 mol % or less, it is synonymous with the degree of neutralization. When the usage equivalent amount of the neutralizing agent in the following formula is greater than 100 mol %, it means that the neutralizing agent is in excess relative to the acid groups of the resin, and the degree of neutralization of the resin at this time is regarded as 100 mol %.

[0143] Neutralizer usage equivalent (mol %) = [{neutralizer added mass (g) / neutralizer equivalent} / [{weighted average acid value of resin (mgKOH / g) × resin mass (g)} / (56 × 1000)]] × 100

[0144] The amount of the aqueous medium added in the phase inversion emulsification method is preferably 100 parts by mass or more, more preferably 150 parts by mass or more, and is preferably 900 parts by mass or less, more preferably 600 parts by mass or less, further preferably 400 parts by mass or less, and even more preferably 250 parts by mass or less, relative to 100 parts by mass of the resin component constituting the resin particles (X), from the viewpoint of improving the dispersion stability of the resin particles (X).

[0145] Further, from the viewpoint of improving the dispersion stability of the resin particles (X), the mass ratio of the aqueous medium to the organic solvent (aqueous medium / organic solvent) is preferably 20 / 80 or more, more preferably 50 / 50 or more, and further preferably 80 / 20 or more, and is preferably 97 / 3 or less, more preferably 93 / 7 or less, and further preferably 90 / 10 or less.

[0146] [ Wax (D) ]

[0147] In the process 1-1, it is preferable to coagulate the wax particles containing the wax (D) together with the resin particles X and the colorant particles.

[0148] As the wax, for example, polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax; microcrystalline wax, paraffin wax, Fischer-Tropsch wax, Sasol wax, or the like hydrocarbon-based wax or their oxides; carnauba wax, montan wax, or their deoxidized wax, ester-based wax such as fatty acid ester wax; fatty acid amide, fatty acid, higher alcohol, fatty acid metal salt can be given. One or two or more kinds thereof can be used.

[0149] The melting point of the wax is preferably 60°C or more, more preferably 70°C or more, and is preferably 160°C or less, more preferably 140°C or less, further preferably 120°C or less, and further preferably 100°C or less.

[0150] The content of the wax is preferably 0.1% by mass or more, more preferably 1% by mass or more, and further preferably 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, in the toner.

[0151] It is preferable to mix the dispersion liquid of the wax particles with the dispersion liquid of the resin particles and the dispersion liquid of the colorant particles and coagulate them, thereby allowing the wax to be contained in the coagulated particles.

[0152] The dispersion liquid of the wax particles can also be obtained using a surfactant, but it is preferable to obtain it by mixing the wax with the resin particles Z described later. By using the wax and the resin particles Z to prepare the wax particles, the resin particles Z can be used to stabilize the wax particles, and the wax can be dispersed in the aqueous medium even without using a surfactant. It is considered that, in the dispersion liquid of the wax particles, a structure in which a large number of resin particles Z are attached to the surface of the wax particles is formed.

[0153] The resin constituting the resin particles Z that disperse the wax is preferably a polyester resin, and from the viewpoint of improving the dispersibility of the wax in the aqueous medium, it is more preferably a composite resin having a polyester resin segment and an addition polymerization-based resin segment.

[0154] The solid content concentration of the wax particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more, and is preferably 50% by mass or less, and more preferably 40% by mass or less, from the viewpoint of improving the productivity of the colorant and improving the dispersion stability of the wax particle dispersion.

[0155] The volume median particle size (D 50 ), from the viewpoint of obtaining uniform agglomerated particles and improving low-temperature fixing properties and the image density of printed materials, it is preferably 0.1 μm or more, more preferably 0.2 μm or more, further preferably 0.3 μm or more, and is preferably 1 μm or less, more preferably 0.8 μm or less, further preferably 0.6 μm or less.

[0156] The CV value of the wax particles is preferably 10% or more, more preferably 25% or more, from the viewpoint of improving toner productivity, and is preferably 50% or less, more preferably 45% or less, and further preferably 42% or less, from the viewpoint of obtaining uniform aggregated particles.

[0157] Specifically, the volume median particle size (D 50 ) and CV values.

[0158] Colorant

[0159] As colorants, pigments and dyes can be mentioned. From the viewpoint of improving low-temperature fixing properties and the image density of printed materials, pigments are preferred. As pigments, cyan pigments, yellow pigments, magenta pigments, and black pigments can be mentioned. Cyan pigments are preferably phthalocyanine pigments, and more preferably copper phthalocyanine. Yellow pigments are preferably monoazo pigments, isoindoline pigments, and benzimidazolone pigments. Magenta pigments are preferably soluble azo pigments such as quinacridone pigments and BONA lake pigments, and insoluble azo pigments such as naphthol AS pigments. Black pigments are preferably carbon black. As dyes, acridine dyes, azo dyes, benzoquinone dyes, azine dyes, anthraquinones, indigo dyes, phthalocyanine dyes, and nigrosine dyes can be mentioned. Colorants can be used alone or in combination of two or more.

[0160] The colorant is preferably added in the form of colorant particles.

[0161] The colorant particles can be produced, for example, by dispersing the colorant and an aqueous medium in the presence of a surfactant or the like using a disperser. Examples of the disperser include a homogenizer and an ultrasonic disperser. The preferred form of the aqueous medium is the same as that used in the aqueous dispersion of the resin particles (X).

[0162] As a dispersion machine, for example, a homomixer, a homogenizer, an ultrasonic disperser can be enumerated. As a commercially available product of a suitable dispersion machine, for example, a homomixer " TKAGI HOMOMIXER 2M-03 " (made by Special Machinery Chemical Industry Co., Ltd.), a high-pressure homogenizer " Microfluidizer M-110EH ", " Microfluidizer M-7115 " (made by Microfluidics Co., Ltd.), an ultrasonic homogenizer " US-600T " (made by Nippon Seiki Co., Ltd.). These dispersion machines can be used alone or in combination.

[0163] The solid content concentration of the dispersion of the colorant particles is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, from the viewpoint of improving the productivity of the toner and improving the dispersion stability of the dispersion of the colorant particles.

[0164] The volume median particle size (D 50 ), from the viewpoint of obtaining a colorant capable of obtaining low-temperature fixing properties and high-quality images, it is preferably 0.050 μm or more, more preferably 0.080 μm or more, further preferably 0.10 μm or more, and is preferably 0.50 μm or less, more preferably 0.30 μm or less, further preferably 0.20 μm or less.

[0165] The CV value of the colorant particles is preferably 10% or more, more preferably 25% or more, from the viewpoint of improving the productivity of the toner, and is preferably 50% or less, more preferably 45% or less, and further preferably 42% or less, from the viewpoint of obtaining uniform agglomerated particles.

[0166] Specifically, the volume median particle size (D 50 ) and CV values.

[0167] 〔Coagulant〕

[0168] Examples of coagulants include cationic surfactants such as quaternary ammonium salts, organic coagulants such as polyethyleneimine, 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 inorganic coagulants such as metal complexes with a valence of 2 or higher. From the perspective of improving cohesion and obtaining uniform coagulated particles, inorganic coagulants with a valence of 1 or higher and 5 or lower are preferred, inorganic metal salts with a valence of 1 or higher and 2 or lower, and inorganic ammonium salts are more preferred, inorganic ammonium salts are even more preferred, and ammonium sulfate is even more preferred.

[0169] The amount of the aggregating agent used is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the resin constituting the resin particles (X) and the resin particles (Y), from the viewpoint of controlling aggregation to obtain a desired particle size. From the viewpoint of improving the low-temperature fixing ability and heat-resistant storage stability of the toner, the amount is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0170] The coagulant is preferably added dropwise to the mixed dispersion in the form of an aqueous solution. The coagulant may be added all at once, intermittently, or continuously. It is preferred to stir the mixture thoroughly during and after addition.

[0171] In addition, from the viewpoint of controlling aggregation to obtain aggregated particles having a desired particle size and particle size distribution, the aqueous solution of the coagulant is preferably adjusted to a pH of 7.0 or higher and 9.0 or lower before use.

[0172] The temperature for dropping the aggregating agent is preferably 0°C or higher, more preferably 10°C or higher, and even more preferably 20°C or higher, and is preferably 45°C or lower, more preferably 40°C or lower, even more preferably 35°C or lower, and even more preferably 30°C or lower, from the viewpoint of improving the productivity of the toner.

[0173] Furthermore, from the perspective of promoting aggregation and obtaining aggregated particles with the desired particle size and particle size distribution, it is preferred to increase the temperature of the dispersion after adding the coagulant. The temperature maintained is preferably 45°C or higher, more preferably 50°C or higher, and even more preferably 55°C or higher, and is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 63°C or lower.

[0174] It is preferred to monitor the volume median diameter of the aggregated particles within the aforementioned temperature range to confirm the progress of aggregation.

[0175] The volume median particle size (D 50 ), preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 4 μm or more, from the viewpoint of excellent low-temperature fixing property, suppression of degradation of low-temperature fixing property over time, and excellent heat-resistant storage property, and preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 6 μm or less. The volume median particle size of the aggregated particles (1) is determined by the method described in the Examples below.

[0176] (Process 1-2)

[0177] [Amorphous resin (C)]

[0178] When step 1-2 is included, the amorphous resin (C) has a crystallinity index greater than 1.4 or less than 0.6. The crystallinity index can be adjusted by adjusting the types and ratios of the raw monomers and the production conditions (e.g., reaction temperature, reaction time, cooling rate, etc.). Alternatively, the value can be determined by the method described in the Examples below.

[0179] The amorphous resin (C) is preferably a polyester resin obtained by polycondensing an alcohol component (C-al) and a carboxylic acid component (C-ac) from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0180] 《Alcohol component (C-al)》

[0181] The alcohol component (C-a1) preferably comprises an alkylene oxide adduct of bisphenol A, and more preferably comprises an alkylene oxide adduct of bisphenol A represented by formula (I), from the viewpoints of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0182] [Chemistry 2]

[0183]

[0184] 〔Where, OR 1 and R 1 O is alkylene oxide, R 1 is an alkylene group having 2 or 3 carbon atoms, preferably an ethylene group, x and y represent positive numbers indicating the average number of added moles of alkylene oxide, and the sum of x and y is 1 or more, preferably 1.5 or more, more preferably 2 or more, and is 16 or less, preferably 8 or less, more preferably 4 or less.]

[0185] The alcohol component (C-a1) preferably contains 80 mol% or more of an alkylene oxide adduct of bisphenol A. The content of the alkylene oxide adduct of bisphenol A in the alcohol component (C-a1) is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, further preferably 98 mol% or more, and is 100 mol% or less, and more preferably 100 mol% or less, from the viewpoints of excellent low-temperature fixing property, suppression of degradation of low-temperature fixing property over time, and excellent heat-resistant storage performance.

[0186] As the alkylene oxide adduct of bisphenol A, a propylene oxide adduct of bisphenol A is preferred from the viewpoints of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0187] Carboxylic acid component (C-ac)

[0188] Examples of the carboxylic acid component (C-ac) include dicarboxylic acids, trivalent or higher polycarboxylic acids, etc. Among them, dicarboxylic acids are preferred, and the combined use of dicarboxylic acids and trivalent or higher polycarboxylic acids is more preferred.

[0189] Examples of the dicarboxylic acid include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. At least one selected from aromatic dicarboxylic acids and aliphatic dicarboxylic acids is preferred, and aromatic dicarboxylic acids are more preferred.

[0190] The carboxylic acid component (C-ac) includes not only free acids but also acid anhydrides that decompose during the reaction to generate acids and alkyl esters of carboxylic acids having 1 to 3 carbon atoms.

[0191] Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. From the viewpoints of excellent low-temperature fixing ability, suppression of degradation of low-temperature fixing ability over time, and excellent heat-resistant storage properties, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred.

[0192] The aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably 30 or less, more preferably 20 or less carbon atoms, from the viewpoint of excellent low-temperature fixing property, suppression of degradation of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0193] Among them, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms is preferred, and dodecenylsuccinic acid is more preferred. Furthermore, from the viewpoints of excellent low-temperature fixing properties, suppression of degradation of low-temperature fixing properties over time, and excellent heat-resistant storage properties, it is more preferred to use succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms in combination with terephthalic acid, fumaric acid, adipic acid, sebacic acid, or the like. It is even more preferred to use terephthalic acid, fumaric acid, and dodecenylsuccinic acid in combination.

[0194] The polycarboxylic acid having a valence of three or more is preferably a tricarboxylic acid from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property. It is more preferably at least one selected from trimellitic acid and its anhydride, and even more preferably trimellitic anhydride.

[0195] In addition, the content of a polycarboxylic acid containing trivalent or higher valence is preferably 3 mol% or more, more preferably 5 mol% or more, and is preferably 30 mol% or less, more preferably 20 mol% or less, in the carboxylic acid component (C-ac), from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0196] These carboxylic acid components (C-ac) can be used alone or in combination of two or more.

[0197] The molar equivalent ratio (COOH group / OH group) of the carboxyl group (COOH group) of the carboxylic acid component (C-ac) to the hydroxyl group (OH group) of the alcohol component (C-al) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.2 or less, more preferably 1.15 or less, and even more preferably 1.12 or less, from the viewpoint of obtaining a resin having preferred thermal properties.

[0198] The softening point of the amorphous resin (C) is preferably 90°C or higher, more preferably 100°C or higher, and even more preferably 105°C or higher, and is preferably 160°C or lower, more preferably 140°C or lower, and even more preferably 120°C or lower, from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0199] The glass transition temperature of the amorphous resin (C) is preferably 40°C or higher, more preferably 50°C or higher, and even more preferably 60°C or higher, and is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 70°C or lower, from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0200] The acid value of the amorphous resin (C) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and even more preferably 15 mgKOH / g or more, from the viewpoint of improving the dispersion stability of the resin particles (Y) described later, and is preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 25 mgKOH / g or less.

[0201] The softening point, glass transition temperature, and acid value can be determined by the methods described in the Examples below. The softening point, glass transition temperature, and acid value of the amorphous resin (C) can be appropriately adjusted by the types and ratios of the raw monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate.

[0202] In addition, when using two or more non-crystalline resins (C) in combination, it is preferable that the softening point, glass transition temperature, and acid value obtained as a mixture thereof are each within the above-mentioned range.

[0203] [Resin particles (Y)]

[0204] The resin particles (Y) are produced by a method in which a resin component containing an amorphous resin (C) is dispersed in an aqueous medium to obtain an aqueous dispersion of the resin particles (Y).

[0205] It is preferred to disperse a resin component containing the amorphous resin (C) and the optional components described above as needed in an aqueous medium to obtain the resin particles (Y) as an aqueous dispersion of the resin particles (Y).

[0206] The method for obtaining the aqueous dispersion and the suitable conditions are the same as those for the resin particles (X).

[0207] The solid content concentration of the aqueous dispersion of the resin particles (Y) is preferably 5% by mass or more, more preferably 15% by mass or more, and even more preferably 30% by mass or more, and is preferably 50% by mass or less, and more preferably 40% by mass or less, from the perspective of improving toner productivity and dispersion stability of the resin particles (Y). It should be noted that the solid content refers to the total amount of non-volatile components such as the resin and surfactant.

[0208] The volume median particle size (D 50 ), from the viewpoint of obtaining a colorant capable of obtaining low-temperature fixing properties and high-quality images, it is preferably 0.05 μm or more, more preferably 0.08 μm or more, further preferably 0.10 μm or more, and is preferably 0.50 μm or less, more preferably 0.30 μm or less, further preferably 0.20 μm or less.

[0209] 〔Agglomerated particles (2)〕

[0210] Step (1-2) is a step of adding resin particles (Y) to the agglomerated particles (1) obtained in step (1-1) to obtain agglomerated particles (2) in which resin particles (Y) are attached to the agglomerated particles (1). It is preferred to add an aqueous dispersion of resin particles (Y) to the aforementioned dispersion of agglomerated particles (1), thereby further attaching resin particles (Y) to the agglomerated particles (1) to obtain a dispersion of agglomerated particles (2).

[0211] Before adding the aqueous dispersion of the resin particles (Y) to the dispersion of the aggregated particles (1), an aqueous medium may be added to dilute the dispersion. Furthermore, when adding the aqueous dispersion of the resin particles (Y) to the dispersion of the aggregated particles (1), the aforementioned coagulant may be used in step (1-2) to efficiently adhere the resin particles (Y) to the aggregated particles (1).

[0212] The temperature when adding the aqueous dispersion of the resin particles (Y) is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower, from the viewpoint of obtaining uniform agglomerated particles, excellent low-temperature fixing property, suppression of degradation of low-temperature fixing property over time, and excellent heat-resistant storage performance.

[0213] The amount of resin particles (Y) added is such that the mass ratio of the resin particles (Y) to the resin particles (X) [(Y) / (X)] is preferably 0.05 or more, more preferably 0.10 or more, and preferably 0.5 or less, more preferably 0.3 or less, further preferably 0.2 or less, and further preferably 0.15 or less, from the viewpoint of excellent low-temperature fixing property, suppression of deterioration of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0214] It should be noted that in the production method of the present invention, in addition to the amorphous resin (A), the crystalline resin (B), and the amorphous resin (C), known resins used in toners, such as styrene-acrylic copolymers, epoxy resins, polycarbonates, and polyurethanes, may be contained within the range that does not impair the effects of the present invention. The mass ratio of the amorphous resin (A) to the crystalline resin (B) [(A) / (B)] is preferably 5 / 5 or more, more preferably 6 / 4 or more, and preferably 9 / 1 or less, more preferably 8 / 2 or less, from the perspective of improving the low-temperature fixing ability and durability of the toner.

[0215] When step (1-2) is carried out, the total content of the amorphous resin (A), the crystalline resin (B) and the amorphous resin (C) is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and further preferably 100% by mass relative to the total amount of the resin components of the colorant, from the viewpoint of excellent low-temperature fixing property and suppression of degradation of low-temperature fixing property over time, and excellent heat-resistant storage property.

[0216] In addition, from the viewpoint of improving the low-temperature fixing ability and durability of the toner, the mass ratio of the amorphous resin (C) to the total of the amorphous resin (A) and the crystalline resin (B) [(C) / ((A)+(B))] is preferably 0.05 or more, more preferably 0.10 or more, and is preferably 0.5 or less, more preferably 0.3 or less, further preferably 0.2 or less, and further preferably 0.15 or less.

[0217] The total mass ratio of the crystalline resin (B) to the amorphous resin (A) and the amorphous resin (C) [(B) / ((A)+(C))] is preferably 0.1 or more, more preferably 0.2 or more, and is preferably 0.5 or less, more preferably 0.4 or less, from the viewpoint of improving the low-temperature fixing ability and durability of the toner.

[0218] The volume median particle size (D 50 ), from the viewpoint of obtaining a colorant capable of obtaining high-quality images, and from the viewpoint of excellent low-temperature fixing ability and suppression of degradation of low-temperature fixing ability over time, and excellent heat-resistant storage performance, it is preferably 2 μm or more, more preferably 3 μm or more, further preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, further preferably 6 μm or less.

[0219] In step (1-2), aggregation of aggregated particles can be stopped when the aggregated particles grow to a particle size suitable for toner.

[0220] Examples of methods for stopping aggregation include cooling the dispersion, adding an aggregation-stopping agent, and diluting the dispersion. From the viewpoint of reliably preventing unnecessary aggregation, stopping aggregation by adding an aggregation-stopping agent is preferred.

[0221] 〔Agglomeration stopper〕

[0222] The aggregation-inhibiting agent is preferably a surfactant, more preferably an anionic surfactant. Examples of the anionic surfactant include alkylbenzene sulfonates, alkyl sulfates, alkyl ether sulfates, and polyoxyalkylene alkyl ether sulfates. Polyoxyalkylene alkyl ether sulfates are preferred, polyoxypropylene lauryl ether sulfates are more preferred, and sodium polyoxypropylene lauryl ether sulfate is even more preferred.

[0223] The aggregation inhibitors can be used alone or in combination of two or more.

[0224] The amount of the aggregation-stopping agent added is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, even more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the total amount of the resin in the toner, from the perspective of reliably preventing unnecessary aggregation. From the perspective of reducing residue in the toner, the amount is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 55 parts by mass or less. From the perspective of improving toner productivity, the aggregation-stopping agent is preferably added as an aqueous solution.

[0225] The temperature for adding the aggregation-stopping agent is preferably the same as the temperature of the dispersion liquid in which the aggregated particles (2) are maintained from the viewpoint of improving the productivity of the toner. The temperature for adding the aggregation-stopping agent is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and is preferably 80°C or lower, more preferably 70°C or lower, and even more preferably 65°C or lower.

[0226] Furthermore, from the viewpoint of stabilizing the aggregated particles and preventing the temporarily aggregated particles from dispersing before fusing, it is preferred to add an acid at the same time as the aggregation is stopped so that the dispersion of the aggregated particles changes from neutral to acidic.

[0227] There is no limitation on the acid to be added. For example, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, etc. are preferred. From the viewpoint of rapid pH change upon addition, at least one selected from hydrochloric acid, sulfuric acid, nitric acid, and acetic acid is preferred, at least one selected from hydrochloric acid, sulfuric acid, and nitric acid is more preferred, and sulfuric acid is still more preferred.

[0228] The acid is preferably added in the form of an aqueous solution and may be added together with the above-mentioned aggregation-inhibiting agent.

[0229] <Process 2>

[0230] Step 2 is a step of, for example, heating and fusing the aggregated particles obtained in step 1 in an aqueous medium to obtain a dispersion of fused particles (resin particle dispersion).

[0231] The particles in the aggregated particles that are mainly physically attached to each other are fused together to form fused particles. Preferably, the volume median particle size is reduced by fusion.

[0232] In addition, step 1 and step 2 may be performed continuously at the same heating temperature.

[0233] In step 2, from the viewpoint of improving the fusibility of the aggregated particles, achieving excellent low-temperature fixability, suppressing the deterioration of the low-temperature fixability over time, and achieving excellent heat-resistant storage properties, the temperature is preferably maintained at a temperature 15° C. or higher lower than the melting point of the crystalline resin (B).

[0234] As for the holding temperature, from the viewpoint of improving the fusibility of the aggregated particles and improving the productivity of the toner, it is more preferably a temperature 10°C lower than the melting point of the crystalline resin (B), further preferably a temperature 8°C lower than the melting point of the crystalline resin (B), further preferably a temperature 5°C lower than the melting point of the crystalline resin (B), further preferably a temperature above the melting point of the crystalline resin (B), and preferably a temperature 30°C higher than the melting point of the crystalline resin (B), more preferably a temperature 20°C higher than the melting point of the crystalline resin (B), further preferably a temperature 12°C higher than the melting point of the crystalline resin (B).

[0235] At this time, the time for maintaining the temperature at a temperature 15°C lower than the melting point of the crystalline resin (B) is preferably 1 minute or more, more preferably 10 minutes or more, and even more preferably 30 minutes or more, and is 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 improving the fusibility of the agglomerated particles and improving the productivity of the colorant.

[0236] The volume median particle size (D 50 ), from the viewpoint of excellent low-temperature fixing property and suppression of degradation of low-temperature fixing property over time and excellent heat-resistant storage property, it is preferably 2 μm or more, more preferably 3 μm or more, further preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, further preferably 6 μm or less.

[0237] The circularity of the fused particles in the resin particle dispersion obtained in step 2 is preferably 0.955 or more, more preferably 0.960 or more, and is preferably 0.990 or less, more preferably 0.985 or less, and even more preferably 0.980 or less, from the viewpoints of excellent low-temperature fixing property and suppression of deterioration of low-temperature fixing property over time, excellent heat-resistant storage property, and obtaining high-quality images.

[0238] <Process 3>

[0239] Step 3 is a step of obtaining a resin particle dispersion for toner by flowing and continuously mixing the resin particle dispersion containing the amorphous resin (A) and the crystalline resin (B) obtained in step 2 with an aqueous medium and then cooling the mixture.

[0240] As an apparatus for causing a resin particle dispersion containing an amorphous resin (A) and a crystalline resin (B) to flow and continuously mix with an aqueous medium, there is no particular limitation as long as the apparatus introduces the resin particle dispersion and the aqueous medium into a single apparatus, mixes them, and discharges them. The apparatus may include an apparatus having two or more inlets and one or more outlets (hereinafter also referred to as a cooling apparatus). Specifically, an inline mixer, a T-tube, a Y-tube, or the like is preferably used, an inline mixer is more preferred, and a static mixer is even more preferred.

[0241] Generally speaking, static mixers do not apply shearing force, or even if they do, the shearing force is weak. Therefore, they can suppress the deformation of the resin and, when the resin particles are core-shell resins, the resin particles are cut off, thereby exposing the core crystalline resin to the resin surface. Therefore, they are suitable for the production of resin particles for toner.

[0242] In addition, static mixers are suitable for industrial production because they can perform continuous processing.

[0243] Therefore, step 3 is preferably a step of obtaining a resin particle dispersion for toner by mixing the resin particle dispersion containing the amorphous resin (A) and the crystalline resin (B) obtained in step 2 with an aqueous medium using a static mixer and cooling the mixture.

[0244] The toner resin particles obtained in step 3 may be core-shell type particles having a core and a shell present on the surface of the core. When the toner resin particles are core-shell type particles, the core contains the amorphous resin (A) and the crystalline resin (B), and the shell contains the amorphous resin (C).

[0245] In the resin particles to be cooled (resin particles in the resin particle dispersion before cooling), the mass ratio of the amorphous resin (A) to the crystalline resin (B) [amorphous resin (A) / crystalline resin (B)] is preferably 50 / 50 or more, more preferably 55 / 45 or more, and even more preferably 60 / 40 or more from the viewpoint of heat-resistant storage stability, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, even more preferably 85 / 15 or less, and even more preferably 80 / 20 or less from the viewpoint of low-temperature fixing property.

[0246] In the cooled resin particles (resin particles in the resin particle dispersion before cooling), the mass ratio of the amorphous resin to the crystalline resin [amorphous resin / crystalline resin] is preferably 50 / 50 or greater, more preferably 55 / 45 or greater, and even more preferably 60 / 40 or greater from the perspective of heat-resistant storage stability, and is preferably 95 / 5 or less, more preferably 90 / 10 or less, even more preferably 85 / 15 or less, and even more preferably 80 / 20 or less from the perspective of low-temperature fixing properties. Here, when the amorphous resin includes the amorphous resin (A) and the amorphous resin (C), this refers to the total amount.

[0247] The so-called static mixer that can be suitably used in step 3 is a stationary mixing agitator without a moving part. More specifically, it refers to an inline mixer designed so that mixing is achieved solely by causing the liquid to reverse and switch its flow as it passes through a resistance member fixed inside the pipe.

[0248] The flow characteristics of the liquid flow, that is, the mixing characteristics, may be changed depending on the structure of the resistance member. A member in which a rectangular plate is twisted 180 degrees in opposite directions is a typical example.

[0249] Such static mixers are available on the market, and representative products thereof are given below.

[0250] (1) 3 / 4-N60S-331-0, 1 / 2-N60S-331-0, and 1-N30-131-F manufactured by Noritake Company Limited

[0251] (2) SMX-DN 25×10 and SMX-DN 25×5 manufactured by SULZER CHEMTECH.

[0252] These static mixers generally have a tube inner diameter of about 20 to 50 mm and a tube length of about 20 to 50 cm.

[0253] Hereinafter, although a static mixer is described as an example, the preferred conditions are the same also for the above-mentioned cooling devices other than the static mixer.

[0254] The method for passing the mixed system of the resin particle dispersion and the aqueous medium through the static mixer is not particularly limited, but pumping is generally used. The delivery rate, while also depending on the inner diameter of the tube, is generally set at approximately 1 to 100 kg / minute. This operation can be repeated multiple times, but is preferably performed once. That is, the mixture can be passed through the static mixer multiple times, but preferably only once.

[0255] The mixing ratio of the aqueous medium to the resin particle dispersion (aqueous medium / resin particle dispersion, mass ratio) is preferably 1 / 1 or more, more preferably 1.5 / 1 or more, and even more preferably 2 / 1 or more, from the viewpoint of accelerating the cooling rate and improving the low-temperature fixing property, and is preferably 10 / 1 or less, more preferably 5 / 1 or less, and even more preferably 3 / 1 or less, from the viewpoint of production efficiency.

[0256] The temperature of the resin particle dispersion before cooling is preferably at least -18°C from the melting point of the crystalline resin (B), more preferably at least -15°C from the melting point of the crystalline resin (B), and even more preferably at least -12°C from the melting point of the crystalline resin (B), from the viewpoint of low-temperature fixing properties. From the viewpoint of economic efficiency, it is preferably at most +30°C from the melting point of the crystalline resin (B), more preferably at most +20°C from the melting point of the crystalline resin (B), and even more preferably at most +10°C from the melting point of the crystalline resin (B).

[0257] The temperature of the resin particle dispersion after cooling is preferably the melting point of the crystalline resin (B) - 20°C or lower, more preferably the melting point of the crystalline resin (B) - 30°C or lower, and even more preferably the melting point of the crystalline resin (B) - 40°C or lower, from the viewpoint of low-temperature fixing properties. From the viewpoint of operating efficiency, it is preferably the melting point of the crystalline resin (B) - 80°C or higher, more preferably the melting point of the crystalline resin (B) - 60°C or higher, and even more preferably the melting point of the crystalline resin (B) - 50°C or higher.

[0258] The temperature of the resin particle dispersion before cooling is preferably not less than 18°C ​​from the melting point of the crystalline resin (B), and the temperature of the resin particle dispersion after cooling is not more than 20°C from the melting point of the crystalline resin (B). More preferably, the temperature of the resin particle dispersion before cooling is not less than 15°C from the melting point of the crystalline resin (B), and the temperature of the resin particle dispersion after cooling is not more than 20°C from the melting point of the crystalline resin (B). Further preferably, the temperature of the resin particle dispersion before cooling is not less than 12°C from the melting point of the crystalline resin (B), and the temperature of the resin particle dispersion after cooling is not more than 30°C from the melting point of the crystalline resin (B). Further preferably, the temperature of the resin particle dispersion before cooling is not less than 12°C from the melting point of the crystalline resin (B), and the temperature of the resin particle dispersion after cooling is not more than 40°C from the melting point of the crystalline resin (B).

[0259] The cooling rate of the resin particle dispersion in step 3 is preferably 20°C / second or more, more preferably 30°C / second or more, and even more preferably 60°C / second or more from the viewpoint of low-temperature fixability, and is preferably 500°C / second or less, more preferably 300°C / second or less, and even more preferably 200°C / second or less from the viewpoint of operability and equipment load.

[0260] Here, the cooling rate is a value obtained by dividing the temperature difference between the resin particle dispersion before cooling and the resin particle dispersion after cooling by the average residence time in the static mixer.

[0261] The average residence time in the static mixer is preferably 0.1 second or more, more preferably 0.15 second or more, and even more preferably 0.2 second or more from the viewpoint of operability, and is preferably 3 seconds or less, more preferably 2 seconds or less, and even more preferably 1 second or less from the viewpoint of low-temperature fixing properties.

[0262] The cooling step is preferably performed by cooling the resin particle dispersion to 20°C or higher, more preferably to 30°C or higher, and even more preferably to 40°C or higher, from the perspective of low-temperature fixing properties. From the perspective of operating efficiency, the cooling step is preferably performed by cooling to 80°C or lower, more preferably to 70°C or lower, and even more preferably to 60°C or lower.

[0263] <Post-processing>

[0264] After step (3), a post-treatment step may be performed, and toner particles are preferably obtained by separation.

[0265] Since the resin particles in the toner resin particle dispersion obtained in step (3) are present in an aqueous medium, solid-liquid separation is preferably performed first. For the solid-liquid separation, a suction filtration method or the like is preferably used.

[0266] It is preferred to perform washing after solid-liquid separation. At this time, it is preferred to also remove the added surfactant, and it is preferred to perform washing with an aqueous medium below the cloud point of the surfactant. It is preferred to perform multiple washings.

[0267] The toner particles are then preferably dried. The drying temperature is preferably set below the glass transition temperature of the resin constituting the particles, and more preferably below the minimum glass transition temperature of the resin constituting the toner particles. Preferred drying methods include vacuum low-temperature drying, vibration-type fluidized bed drying, fluidized bed drying, spray drying, freeze drying, and rapid jet drying. The moisture content after drying is preferably adjusted to 1.5% by mass or less, and more preferably 1.0% by mass or less, to improve the charging properties of the toner.

[0268] [toner for electrostatic image development]

[0269] [toner particles]

[0270] While the toner particles obtained by performing drying or the like can be used as the toner for electrostatic image development as they are, it is preferable to use the toner particles obtained by treating the surface of the toner particles as described later as the toner for electrostatic image development.

[0271] In the case where the production method of the toner resin particle dispersion liquid of the present application has the step 1-1 and the step 1-2, the content of the crystalline resin (B) in the coagulated particles (1) obtained in the step 1-1 is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more, and is preferably 45% by mass or less, more preferably 40% by mass or less, and further preferably 35% by mass or less, from the viewpoints of excellent low-temperature fixing property, suppression of reduction in low-temperature fixing property over time, and excellent heat-resistant storage property.

[0272] In the case where the production method of the toner resin particle dispersion liquid of the present application has the step 1-1 and the step 1-2, the amount of the amorphous resin (C) added in the step 1-2 with respect to the total amount of the crystalline resin (B) and the amorphous resin (A) contained in the coagulated particles (1) obtained in the step 1-1 is preferably 3% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less, from the viewpoints of excellent low-temperature fixing property, suppression of reduction in low-temperature fixing property over time, and excellent heat-resistant storage property.

[0273] In addition, the content of the crystalline resin (B) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more, and is preferably 45% by mass or less, more preferably 40% by mass or less, and further preferably 35% by mass or less, with respect to the total amount of the resin components in the toner, from the viewpoints of excellent low-temperature fixing property, suppression of reduction in low-temperature fixing property over time, and excellent heat-resistant storage property.

[0274] The volume median particle diameter (D 50), from the viewpoint of improving the productivity of the colorant, improving the image density of the printed matter, excellent low-temperature fixing ability and suppression of the decrease in low-temperature fixing ability over time, and excellent heat-resistant storage performance, it is preferably 2 μm or more, more preferably 3 μm or more, further preferably 4 μm or more, and is preferably 10 μm or less, more preferably 8 μm or less, further preferably 6 μm or less.

[0275] The CV value of the colorant particles is preferably 12% or more, more preferably 16% or more, and further preferably 20% or more from the viewpoint of improving the productivity of the colorant, and is preferably 30% or less, more preferably 26% or less from the viewpoint of obtaining high-quality images.

[0276] The circularity of the colorant particles is preferably 0.955 or more, more preferably 0.960 or more, and even more preferably 0.965 or more, and is preferably 0.990 or less, more preferably 0.985 or less, and even more preferably 0.980 or less, from the viewpoint of improving the low-temperature fixing ability and charging characteristics of the colorant.

[0277] It is preferable to treat the toner particles by adding a fluidizing agent or the like as an external additive to the toner particle surface, and use the obtained material as the toner.

[0278] Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide fine particles, aluminum oxide fine particles, cerium oxide fine particles, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred.

[0279] When surface treatment of the toner particles is performed using an external additive, the amount of the external additive added is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, and is preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and even more preferably 4 parts by mass or less, relative to 100 parts by mass of the toner particles.

[0280] The external additives may be used alone or in combination of two or more. When two or more external additives are used in combination, the total amount of the external additives added is preferably the above-mentioned amount.

[0281] The electrostatic image developing toner obtained by the present invention can be used as a single-component developer or as a two-component developer after being mixed with a carrier.

[0282] The present invention also discloses the following [1] to

[29] .

[0283] [1] A method for producing a resin particle dispersion for toner, comprising the steps of flowing a resin particle dispersion containing an amorphous resin and a crystalline resin with an aqueous medium, continuously mixing the mixture, and then cooling the mixture.

[0284] [2] The method for producing a resin particle dispersion for toner according to [1], wherein the cooling step is a step of continuously mixing the resin particle dispersion and the aqueous medium using a static mixer.

[0285] [3] The method for producing a resin particle dispersion for toner according to [2], wherein the average residence time in the static mixer is 3 seconds or less.

[0286] [4] The method for producing a resin particle dispersion for toner according to [2] or [3], wherein the average residence time in the static mixer is 0.1 seconds to 3 seconds.

[0287] [5] The method for producing a resin particle dispersion for toner according to any one of [2] to [4], wherein the average residence time in the static mixer is 0.1 seconds to 2 seconds.

[0288] [6] The method for producing a resin particle dispersion for toner according to any one of [2] to [5], wherein the average residence time in the static mixer is 0.15 seconds to 2 seconds or less.

[0289] [7] The method for producing a resin particle dispersion for toner according to any one of [1] to [6], wherein the cooling rate in the cooling step is 20° C. / second or more.

[0290] [8] The method for producing a resin particle dispersion for toner according to any one of [1] to [7], wherein the cooling rate in the cooling step is 20° C. / s to 500° C. / s.

[0291] [9] The method for producing a resin particle dispersion for toner according to any one of [1] to [8], wherein the cooling rate in the cooling step is 30° C. / s to 300° C. / s.

[0292]

[10] The method for producing a resin particle dispersion for toner according to any one of [1] to [9], wherein the cooling rate in the cooling step is 60° C. / s to 200° C. / s.

[0293]

[11] The method for producing a resin particle dispersion for toner according to any one of [1] to

[10] , wherein the cooling step is a step of cooling the resin particle dispersion to 20° C. or higher.

[0294]

[12] The method for producing a resin particle dispersion for toner according to any one of [1] to

[11] , wherein the cooling step is a step of cooling the resin particle dispersion to a temperature of 20° C. to 80° C.

[0295]

[13] The method for producing a resin particle dispersion for toner according to any one of [1] to

[12] , wherein the cooling step is a step of cooling the resin particle dispersion to 30° C. or higher and 80° C. or lower.

[0296]

[14] The method for producing a resin particle dispersion for toner according to any one of [1] to

[13] , wherein the cooling step is a step of cooling the resin particle dispersion to 40° C. or higher and 70° C. or lower.

[0297]

[15] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[14] , wherein the temperature of the resin particle dispersion before cooling is at least -18°C from the melting point of the crystalline resin, and the temperature of the resin particle dispersion after cooling is at most -20°C from the melting point of the crystalline resin.

[0298]

[16] A method for producing a resin particle dispersion for a toner according to any one of [1] to

[15] , wherein the temperature of the resin particle dispersion before cooling is not less than -18°C of the melting point of the crystalline resin and not more than +30°C of the melting point of the crystalline resin.

[0299]

[17] A method for producing a resin particle dispersion for a toner according to any one of [1] to

[16] , wherein the temperature of the resin particle dispersion before cooling is not less than -15°C of the melting point of the crystalline resin and not more than +30°C of the melting point of the crystalline resin.

[0300]

[18] A method for producing a resin particle dispersion for a toner according to any one of [1] to

[17] , wherein the temperature of the resin particle dispersion before cooling is not less than -15°C of the melting point of the crystalline resin and not more than +20°C of the melting point of the crystalline resin.

[0301]

[19] The method for producing a resin particle dispersion for a toner according to any one of [1] to

[18] , wherein the temperature of the resin particle dispersion after cooling is not less than -80°C of the melting point of the crystalline resin and not more than -20°C of the melting point of the crystalline resin.

[0302]

[20] A method for producing a resin particle dispersion for a toner according to any one of [1] to

[19] , wherein the temperature of the resin particle dispersion after cooling is not less than -80°C of the melting point of the crystalline resin and not more than -30°C of the melting point of the crystalline resin.

[0303]

[21] The method for producing a resin particle dispersion for a toner according to any one of [1] to

[20] , wherein the temperature of the resin particle dispersion after cooling is not less than -60°C of the melting point of the crystalline resin and not more than -30°C of the melting point of the crystalline resin.

[0304]

[22] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[21] , wherein the mixing ratio of the aqueous medium to the resin particle dispersion (aqueous medium / resin particle dispersion) is greater than 1 / 1 and less than 10 / 1.

[0305]

[23] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[22] , wherein the mixing ratio of the aqueous medium to the resin particle dispersion (aqueous medium / resin particle dispersion) is greater than 1.5 / 1 and less than 10 / 1.

[0306]

[24] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[23] , wherein the mixing ratio of the aqueous medium to the resin particle dispersion (aqueous medium / resin particle dispersion) is greater than 1.5 / 1 and less than 5 / 1.

[0307]

[25] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[24] , wherein the mass ratio of the amorphous resin to the crystalline resin [amorphous resin / crystalline resin] in the resin particles to be cooled (resin particles in the resin particle dispersion before cooling) is greater than 50 / 50 and less than 95 / 5.

[0308]

[26] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[25] , wherein the mass ratio of the amorphous resin to the crystalline resin [amorphous resin / crystalline resin] in the resin particles to be cooled (resin particles in the resin particle dispersion before cooling) is 55 / 45 or more and 90 / 10 or less.

[0309]

[27] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[26] , wherein the mass ratio of the amorphous resin to the crystalline resin [amorphous resin / crystalline resin] in the resin particles to be cooled (resin particles in the resin particle dispersion before cooling) is greater than 60 / 40 and less than 85 / 15.

[0310]

[28] A method for producing a resin particle dispersion for a colorant according to any one of [1] to

[27] , wherein the resin particle dispersion before cooling is a dispersion of fused particles obtained by using steps 1 and 2, wherein the step 1 is a step of agglomerating amorphous resin and crystalline resin in an aqueous medium to obtain a dispersion of agglomerated particles, and the step 2 is a step of heating and fusing the obtained agglomerated particles in an aqueous medium to obtain a dispersion of fused particles.

[0311]

[29] A method for producing a toner for electrostatic image development, comprising the method according to any one of [1] to

[28] .

[0312] Example

[0313] The values ​​of various properties were measured by the following methods. Various evaluations were performed by the following methods.

[0314] [Measurement]

[0315] 〔Acid value and hydroxyl value of resin and wax〕

[0316] The acid value and hydroxyl value of the resin and wax were measured according to the neutralization titration method described in JIS K 0070: 1992. However, the measurement solvent was chloroform.

[0317] 〔Resin softening point, crystallinity index, melting point and glass transition temperature〕

[0318] (1) Softening point

[0319] Using a rheometer "CFT-500D" (manufactured by Shimadzu Corporation), a 1g sample was heated at a rate of 6°C / min while applying a load of 1.96 MPa with a plunger, and extruded from a nozzle with a diameter of 1mm and a length of 1mm. The amount of plunger descent was plotted against temperature, and the temperature at which half of the sample had flowed out was defined as the softening point.

[0320] (2) Crystallinity index

[0321] Using a differential scanning calorimeter "Q100" (manufactured by TA Instrument Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan and cooled from room temperature (20°C) to 0°C at a cooling rate of 10°C / min. The sample was then left as is for 1 minute, then heated to 180°C at a heating rate of 10°C / min, and the calorific value 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). The crystallinity index was calculated as (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)).

[0322] (3) Melting point and glass transition temperature

[0323] Using a differential scanning calorimeter "Q100" (manufactured by TA Instrument Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan, heated to 200°C, and then cooled from this temperature to 0°C at a cooling rate of 10°C / min. The sample was then heated at a heating rate of 10°C / min, and the calorific value 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 a crystalline resin, this peak temperature was defined as the melting point.

[0324] In addition, in the case of an amorphous resin, when a peak is observed, the temperature of the peak is set as the glass transition temperature. When no peak is observed but a step is observed, the temperature of the intersection of the tangent line showing the maximum inclination of the curve of the step part and the extension line of the baseline on the low temperature side of the step is set as the glass transition temperature.

[0325] Melting point of wax

[0326] Using a differential scanning calorimeter "Q100" (manufactured by TA Instrument Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a temperature drop rate of 10°C / min. The sample was then heated at a temperature drop rate of 10°C / min, and the heat content was measured. The maximum peak temperature of the endothermic absorption was defined as the melting point.

[0327] [Number average molecular weight of wax (Mn)]

[0328] The number average molecular weight (Mn) was measured by the gel permeation chromatography (GPC) method shown below.

[0329] (1) Preparation of sample solution

[0330] A sample was dissolved in chloroform at 25° C. to a concentration of 0.5 g / 100 mL, and the solution was filtered using a 0.2 μm pore size fluororesin filter “DISMIC, 25JP” (manufactured by ADVANTEC) to remove insoluble components to prepare a sample solution.

[0331] (2) Determination

[0332] Using the following measuring apparatus and analytical column, chloroform was allowed to flow as the eluent at a flow rate of 1 mL / min. The column was stabilized in a thermostat at 40°C, and 100 μL of the sample solution was injected into the column to measure the molecular weight. The molecular weight (number average molecular weight Mn) of the sample was obtained by using the type name (Mw) of various monodisperse polystyrenes "TSKgel Standard Polystyrenes": "A-500 (5.0 × 10 2 )", "A-1000(1.01×10 3), "A-2500 (2.63 x 10 3 ), "A-5000 (5.97 x 10 3 ), "F-1 (1.02 x 10 4 ), "F-2 (1.81 x 10 4 ), "F-4 (3.97 x 10 4 ), "F-10 (9.64 x 10 4 ), "F-20 (1.90 x 10 5 ), "F-40 (4.27 x 10 5 ), "F-80 (7.06 x 10 5 ), "F-128 (1.09 x 10 6 ) (manufactured by Tosoh Corporation) were used as standard samples, and the concentration was calculated based on a standard curve prepared in advance.

[0333] • Measuring device: "HLC-8220 GPC" (manufactured by Tosoh Corporation)

[0334] • Analysis column: "GMHXL" and "G3000HXL" (manufactured by Tosoh Corporation)

[0335] [Volume median particle diameter (D 50 ) and CV value of resin particles, colorant particles, and wax particles]

[0336] (1) Measuring device: Laser diffraction type particle size measuring machine "LA-920" (manufactured by Horiba Ltd.)

[0337] (2) Measuring conditions: Distilled water was added to a measuring cell, and the volume median particle diameter (D 50 ) and the volume average particle diameter were measured at a concentration in which the absorbance was in an appropriate range. Note that the relative refractive index was set to 1.10, the circulation pump was set to ON, and the circulation speed was set to 5. In addition, the CV value was calculated in accordance with the following equation.

[0338] CV value (%) = (standard deviation of particle size distribution / volume average particle diameter) x 100

[0339] [Concentration of solid content of resin particle dispersion liquid, colorant particle dispersion liquid, and wax particle dispersion liquid]

[0340] Using an infrared moisture meter "FD-230" (manufactured by KETT Science Institute Co., Ltd.), the moisture content (mass %) of 5 g of the measurement sample was measured at a drying temperature of 150°C and in measurement mode 96 (monitoring time 2.5 minutes, variation range of moisture content 0.05%). The concentration of solid content was calculated in accordance with the following equation.

[0341] Solid content concentration (mass %) = 100 - water (mass %)

[0342] Volume median diameter of agglomerated particles (D 50 )〕

[0343] (1) Measuring device: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter Co., Ltd.)

[0344] (2) Analysis software: "Multisizer (registered trademark) III Version 3.51" (manufactured by Beckman Coulter Co., Ltd.)

[0345] (3) Measurement conditions:

[0346] Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter Co., Ltd.)

[0347] Aperture diameter: 50μm

[0348] The sample dispersion was added to 100 mL of the electrolyte solution, and the concentration was adjusted to be able to measure the particle size of 30,000 particles in 20 seconds. 30,000 particles were measured again, and the volume median particle size (D) was calculated based on the particle size distribution. 50 ).

[0349] [Low-temperature fixability of toner]

[0350] The amount of toner adhered to the paper was 0.45 ± 0.03 mg / cm2 when the toner was outputted without fixing the toner over a length of 50 mm using a commercially available printer "Microline (registered trademark) 5400" (manufactured by Okidata Co., Ltd.) onto high-quality "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), leaving a 5 mm margin from the top of the A4 paper. 2 Full page image.

[0351] Next, the same printer was prepared in which a fixing device was modified to have a variable temperature. The fixing device temperature was set to 90° C., and the toner was fixed at a rate of 1.5 seconds to obtain a printed product.

[0352] The toner was fixed in the same manner by increasing the temperature of the fixing device by 5° C. at a time to obtain a printed matter.

[0353] Gently apply the repair tape "Scotch (registered trademark) Repair Tape 810" (manufactured by Sumitomo 3M Co., Ltd., width 18 mm) from the upper margin of the printed image to the solid image. Cut the tape into 50 mm lengths and place 500 g (shape: cylindrical, bottom area 1963 cm) on the printed image. 2) weight, pushing back and forth once at a speed of 10 mm / s. The applied tape was then peeled off from the lower end at a peeling angle of 180° and a speed of 10 mm / s, yielding a printed material after the tape was peeled off. Thirty sheets of high-quality "excellent white" A4-size paper (manufactured by Okidata Co., Ltd.) were placed under the printed material before and after the tape was applied. A "SpectroEye" colorimeter (manufactured by GretagMacbeth, illumination conditions: standard illuminant D50, observation field 2°, concentration reference DINNB, absolute white reference) was used to measure the reflected image density of the fixed image portion of each printed material before and after the tape was applied. The fixing rate was calculated based on the respective reflected image densities according to the following formula.

[0354] Fixing rate (%) = (reflection image density after tape peeling / reflection image density before tape sticking) × 100

[0355] The lowest temperature at which the fixing rate reaches 90% or higher is defined as the minimum fixing temperature. The lower the minimum fixing temperature, the better the low-temperature fixing property.

[0356] [Manufacturing of resin]

[0357] Production Example A1 (Production of Amorphous Resin A-1)

[0358] The interior of a 20 L four-necked flask equipped with a nitrogen inlet, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen. 6536 g of a polypropylene oxide (2.2) adduct of bisphenol A, 2170 g of terephthalic acid, 60 g of tin(II) di(2-ethylhexanoate), 6 g of 3,4,5-trihydroxybenzoic acid, and 788 g of hydrocarbon wax W1 "Paracol 6490" (manufactured by Nippon Seiro Co., Ltd.) were added. Under a nitrogen atmosphere, the temperature was raised to 235°C while stirring. After maintaining the temperature at 235°C for 8 hours, the pressure in the flask was reduced and maintained at 8 kPa for 1 hour. The flask was then returned to atmospheric pressure and cooled to 155°C. While maintaining the temperature at 155°C, a mixture of 4276 g of styrene, 1068 g of stearyl methacrylate, 216 g of acrylic acid, and 642 g of dibutyl peroxide was added dropwise over 3 hours. After maintaining the temperature at 155°C for 30 minutes, the temperature was raised to 200°C, and the pressure in the flask was reduced and maintained at 8 kPa for 1 hour. The flask was then returned to atmospheric pressure and cooled to 190°C. 140 g of fumaric acid, 538 g of trimellitic anhydride, and 5.0 g of 4-tert-butylcatechol were added. The temperature was then raised to 210°C at a rate of 10°C / hr. The reaction was then continued at 8 kPa until the desired softening point was reached, yielding amorphous resin A-1. The physical properties are shown in Table 1.

[0359] Production Example A2 (Production of Amorphous Resin A-2)

[0360] The atmosphere in a 10-liter four-necked flask equipped with a nitrogen inlet, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen. 4313 g of a polypropylene oxide (2.2) adduct of bisphenol A, 818 g of terephthalic acid, 727 g of succinic acid, 30 g of tin(II) di(2-ethylhexanoate), and 3.0 g of 3,4,5-trihydroxybenzoic acid were added. Under a nitrogen atmosphere, the temperature was raised to 235°C while stirring. After maintaining the temperature at 235°C for 5 hours, the pressure in the flask was reduced and maintained at 8 kPa for 1 hour. The flask was then returned to atmospheric pressure and cooled to 160°C. While maintaining the temperature at 160°C, a mixture of 2756 g of styrene, 689 g of stearyl methacrylate, 142 g of acrylic acid, and 413 g of dibutyl peroxide was added dropwise over 1 hour. After maintaining at 160°C for 30 minutes, the temperature was raised to 200°C, and the pressure in the flask was reduced, and the reaction was carried out at 8 kPa until the desired softening point was reached, thereby obtaining amorphous resin A-2.

[0361] Production Example C1 (Production of Amorphous Resin C-1)

[0362] The interior of a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 5363 g of an ethylene oxide (2.2) adduct of bisphenol A, 1780 g of terephthalic acid, 40 g of di(2-ethylhexanoate)tin(II), and 4 g of 3,4,5-trihydroxybenzoic acid were added. Under a nitrogen atmosphere, the temperature was raised to 235° C. while stirring. After maintaining at 235° C. for 8 hours, the pressure in the flask was reduced and maintained at 8 kPa for 1 hour. After returning to atmospheric pressure, the mixture was cooled to 180°C, and 287 g of fumaric acid, 221 g of dodecenylsuccinic anhydride, 380 g of trimellitic anhydride, and 2.5 g of 4-tert-butylcatechol were added. The temperature was then raised to 220°C at a rate of 10°C / hr. The pressure in the flask was then reduced, and the reaction was continued at 10 kPa until the desired softening point was reached, yielding amorphous resin C-1. Various physical properties of the resin were measured and are shown in Table 1. Various physical properties of the resin were measured and are shown in Table 1.

[0363] [Table 1]

[0364] Table 1

[0365]

[0366] *1: BPA-PO is a polypropylene oxide (2.2) adduct of bisphenol A. The values ​​in parentheses indicate an average addition mole of 2.2.

[0367] *2: It means the molar parts of each monomer constituting the raw material monomer P and the bireactive monomer when the alcohol component of the raw material monomer P is taken as 100 molar parts.

[0368] *3: It means the content (mass %) of each monomer constituting the raw material monomer (V) in the total amount of the raw material monomer V.

[0369] *4: Calculated based on the ratio of the raw monomers, hydrocarbon wax W1, bireactive monomer, and radical polymerization initiator, without considering the amount of dehydration due to polycondensation. The mass of the radical polymerization initiator is included in the addition polymerization resin segment.

[0370] *5: Paracol 6490: Made by Nippon Seiro Co., Ltd., Mn 800, melting point 76°C, acid value 18 mgKOH / g, hydroxyl value 97 mgKOH / g

[0371] Production Example B1 (Production of Crystalline Resin B-1)

[0372] The interior of a 10-L four-necked flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was purged with nitrogen. 3416 g of 1,10-decanediol and 4084 g of sebacic acid were added and heated to 135°C while stirring. After maintaining at 135°C for 3 hours, the temperature was raised from 135°C to 200°C over 10 hours. Subsequently, 23 g of tin(II) mono(2-ethylhexanoate) was added. After maintaining at 200°C for another hour, the pressure in the flask was reduced and the flask was maintained at a reduced pressure of 8 kPa for 1 hour to obtain crystalline resin B-1. The physical properties are shown in Table 2.

[0373] [Table 2]

[0374] Table 2

[0375]

[0376] *1: It means the molar part of each monomer constituting the raw material monomer when the alcohol component of the raw material monomer is taken as 100 molar parts.

[0377] [Manufacturing of Resin Particle Dispersion]

[0378] Production Example X1 (Production of Resin Particle Dispersion X-1)

[0379] In a 100 L reaction vessel equipped with a stirrer, a cooler, a thermometer, and a nitrogen inlet tube, 12,600 g of amorphous resin A-1, 5,400 g of crystalline resin B-1, and 18,000 g of methyl ethyl ketone were added and stirred at 73°C for 4 hours to dissolve the resins. A 5% by mass aqueous sodium hydroxide solution was added to the resulting solution to a neutralization degree of 50 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes.

[0380] Then, while maintaining the temperature at 73°C, 36,000 g of deionized water was added over 60 minutes while stirring to perform phase inversion emulsification. The temperature was maintained at 73°C, and methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, the aqueous dispersion was cooled to 30°C while stirring, and deionized water was added to make the solid content concentration 35% by mass. Then, the dispersion was filtered through a 150-mesh metal mesh to obtain a resin particle dispersion X-1. The volume median particle size (D 50 ) and CV values ​​are shown in Table 3.

[0381] [Table 3]

[0382] Table 3

[0383] Manufacturing Example Production Example X1 Resin particle dispersion X-1 Amorphous resin (A) A-1 Amorphous resin (B) B-1 (A) / (B) 70 / 30 Volume median particle size D 5o (μm) 0.18 CV value (%) 23

[0384] Production Example Y1

[0385] (Production of Resin Particle Dispersion Y-1)

[0386] 2000 g of amorphous resin C-1 and 2000 g of methyl ethyl ketone were added to a 10 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, and the resin was dissolved at 73°C for 3 hours. A 5% by mass aqueous sodium hydroxide solution was added to the resulting solution so that the acid value relative to the amorphous resin C-1 reached a neutralization degree of 60 mol%, and stirred for 30 minutes. Then, while maintaining 73°C and stirring at 250 r / min, 4000 g of deionized water was added over 60 minutes to perform phase inversion emulsification. While continuing to maintain 73°C, the methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, the aqueous dispersion was cooled to 30°C while stirring at 200 r / min, deionized water was added so that the solid content concentration was 35% by mass, and then filtered with a 150 mesh metal mesh to obtain a resin particle dispersion Y-1. The volume median particle size (D 50 ) is 0.11 μm and the CV value is 23%.

[0387] Production Example Z1

[0388] (Production of Resin Particle Dispersion Z-1)

[0389] 1200 g of amorphous resin A-2 and 1200 g of methyl ethyl ketone were added to a 10 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube. The resin was dissolved at 73°C over 2 hours. A 5% by mass aqueous sodium hydroxide solution was added to the resulting solution to a neutralization degree of 60 mol% relative to the acid value of the amorphous resin A-2, and the mixture was stirred for 60 minutes.

[0390] Then, while maintaining the temperature at 73°C, 2400 g of deionized water was added over 60 minutes while stirring at 250 r / min (circumferential speed 79 m / min) to perform phase inversion emulsification. Continuing to maintain the temperature at 73°C, methyl ethyl ketone was distilled off under reduced pressure to obtain an aqueous dispersion. Thereafter, after the aqueous dispersion was cooled to 30°C while stirring at 280 r / min (circumferential speed 88 m / min), deionized water was added to make the solid content concentration 35% by mass, and then filtered with a 150-mesh metal mesh to obtain a resin particle dispersion Z-1. The volume median particle size (D 50 ) is 0.09 μm and the CV value is 23%.

[0391] [Production of Wax Particle Dispersion]

[0392] Preparation Example D1 (Preparation of Wax Particle Dispersion D-1)

[0393] 7572 g of deionized water, 3429 g of resin particle dispersion Z-13 and 3000 g of paraffin "HNP-9" (manufactured by Nippon Seira Co., Ltd., melting point 75°C) were added to a stainless steel container with an internal volume of 30 L, and the mixture was melted while being maintained at a temperature of 90 to 95°C and stirred to obtain a molten mixture. The obtained molten mixture was dispersed at 40 MPa for 120 minutes using a pressure ejection type homogenizer (manufactured by Golin Co., Ltd., Golin homogenizer) while being maintained at a temperature of 90 to 95°C, and then cooled to room temperature. Deionized water was added to adjust the solid content concentration to 30% by mass to obtain a wax particle dispersion D-1. The volume median particle size D of the wax particles in the dispersion was adjusted to 100%. 50 The CV values ​​are shown in Table 4.

[0394] [Table 4]

[0395] Table 4

[0396] Manufacturing Example Production Example D1 Wax particle dispersion D-1 wax HNP-9*1 Melting point of wax (℃) 75 Resin particle dispersion Z-1 <![CDATA[体积中值粒径D 50 (μm)]]> 0.47 CV value (%) 27

[0397] *1: HNP-9: Paraffin wax (manufactured by Nippon Seiro Co., Ltd.)

[0398] [Production of Colorant Particle Dispersion]

[0399] Production Example P1 (Production of Colorant Particle Dispersion Liquid P-1)

[0400] In a stainless steel container with an internal volume of 10 L, 2400 g of a cyan pigment "ECB-301" (copper phthalocyanine pigment manufactured by Dainichi Seika Industries, Ltd.), 960 g of polyoxyethylene (13) distyrenated phenyl ether "Emulgen A-60" (manufactured by Kao Corporation, nonionic surfactant, average addition mole number of polyethylene oxide is 13) and 4800 g of deionized water were mixed and dispersed at room temperature for 1 hour using a homomixer "TKAGI HOMOMIXER 2M-03" (manufactured by Tokushiki Kagaku Kogyo Co., Ltd.) at a stirring blade speed of 8000 rpm. The mixture was then treated with a "Microfluidizer M-7115" (manufactured by Microfluidics) at a pressure of 150 MPa for 15 cycles, and then passed through a 200-mesh filter. Deionized water was added to adjust the solid content concentration to 30% by mass, thereby obtaining a colorant particle dispersion P-1. The volume median particle size (D) of the obtained colorant particles was 2.3747 W / cm2. 50 ) is 0.18 μm and the CV value is 25%.

[0401] Example 1

[0402] (Cohesion and Fusion Process)

[0403] In a 300-liter spherical-bottom cylindrical tank (inner diameter 0.7 m) equipped with a stirring device and a hot water jacket and 45° inclined paddle blades (blade diameter 0.35 m), 26.03 kg of resin particle dispersion X-1, 10.44 kg of wax particle dispersion D-1, 5.30 kg of colorant particle dispersion P-1, 0.93 kg of a 10% by mass aqueous solution of Emulgen 150 (manufactured by Kao Corporation, polyoxypropylene lauryl ether), 1.24 kg of Neopelex G-15 (manufactured by Kao Corporation, sodium dodecylbenzenesulfonate), and 21.19 kg of deionized water were mixed at a temperature of 25°C and a stirring speed of 40 r / min for 5 minutes. Then, while stirring the mixture, a solution prepared by adding 2.72 kg of a 4.8% by mass potassium hydroxide aqueous solution to an aqueous solution of 3.20 kg of ammonium sulfate dissolved in 46.46 kg of deionized water to adjust the pH to 8.6 was added dropwise at 25°C over 30 minutes. The stirring speed was then increased to 92 r / min, and the temperature was raised to 62°C over 2 hours and maintained at 62°C until the volume median particle size of the aggregated particles reached 5.2 μm, thereby preparing a dispersion of aggregated particles (1).

[0404] The dispersion of the above-mentioned agglomerated particles (1) was cooled to 53°C over 30 minutes. While maintaining the temperature at 53°C, 3.15 kg of the resin particle dispersion Y-1 and 1.69 kg of deionized water were added dropwise over 1 hour to prepare a dispersion of agglomerated particles (2).

[0405] To the dispersion of the aggregated particles (2) were added 20.75 kg of anionic surfactant "Emul (registered trademark) E-27C" (manufactured by Kao Corporation, containing sodium polyoxypropylene lauryl ether sulfate, effective concentration 27% by mass), 35.27 kg of deionized water, and 3.12 kg of an aqueous solution of 0.1 mol / L sulfuric acid. The mixture was then heated to 75°C over 1 hour, and 7.75 kg of 0.1 mol / L sulfuric acid was added. The mixture was then maintained at 75°C until the circularity reached 0.963 and the volume median particle size reached 4.9 μm, thereby preparing a dispersion of toner resin particles (3) in which the aggregated particles were fused.

[0406] (Cooling process)

[0407] 124.4 kg of deionized water was added to a 200-liter metal drum and cooled to 7.7°C. The cooled deionized water (124.4 kg) and the fused toner particle dispersion (3) (55.3 kg) were fed to a static mixer (model 1 / 4-N30-232-F, manufactured by Noritake Co., Ltd.) at 2.43 kg / min and 1.08 kg / min, respectively, and mixed. The toner resin particle dispersion was cooled to 27°C. The fused toner resin particles were cooled in the pipeline during transportation and were at 71°C at the inlet of the static mixer.

[0408] The static mixer used had 12 stirring blades, a pipe inner diameter of 10.5 mm, and a length of 200 mm. The residence time in the static mixer used was 0.3 seconds.

[0409] (Filtration and drying process)

[0410] The cooled dispersion of the toner resin particles was suction filtered to separate the solid content, washed with 25°C deionized water, and suction filtered at 25°C for 2 hours. Thereafter, the dispersion was vacuum dried at 33°C for 48 hours using a vacuum low-temperature dryer (DRV622DA manufactured by ADVANTEC) to prepare toner particles (4).

[0411] (External addition process)

[0412] 100 parts by mass of the toner particles (4), 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon AEROSIL Co., Ltd., number average particle size: 0.04 μm), and 1.0 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., number average particle size: 0.012 μm) were added to a Henschel mixer and stirred. The mixture was then passed through a 150-mesh sieve to obtain Toner 1. The evaluation results of the obtained Toner 1 are shown in Table 5.

[0413] Example 2

[0414] Toner 2 was obtained in the same manner as in Example 1 except that the cooling step was changed as shown below. The evaluation results of the obtained Toner 2 are shown in Table 5.

[0415] (Cooling process)

[0416] 16.3 kg of deionized water was added to a 50-liter stainless steel drum and cooled to 10.6°C. The cooled deionized water (16.3 kg) and the fused toner particle dispersion (3) (7.2 kg) were fed to a static mixer (model 1 / 4-N30-232-F, manufactured by Noritake Co., Ltd.) at 1.42 kg / min and 0.63 kg / min, respectively, and mixed to cool the toner resin particle dispersion to 26.3°C. The fused toner resin particles were cooled in the pipeline during transport and had a temperature of 65.2°C at the inlet of the static mixer.

[0417] The static mixer used had 12 stirring blades, a pipe inner diameter of 10.5 mm, and a length of 200 mm. The residence time in the static mixer used was 0.5 seconds.

[0418] Example 3

[0419] Toner 3 was obtained in the same manner as in Example 2 except that the filtration and drying step was changed as shown below. The evaluation results of the obtained Toner 3 are shown in Table 5.

[0420] (Filtration and drying process)

[0421] The cooled dispersion of the toner resin particles was transferred to a filter press (PF-7C manufactured by Nippon Filter Equipment Co., Ltd.), squeezed to separate the solid content, and then washed with deionized water at 25°C. Thereafter, an airflow dryer (FJD-4 manufactured by Seishin Enterprise Co., Ltd.) was used at an inlet air volume of 10 m 3 The toner particles (3) were prepared by drying under the conditions of 43°C / min, inlet temperature of 43°C, and outlet temperature of 37°C.

[0422] Example 4

[0423] Toner 4 was obtained in the same manner as in Example 3 except that the cooling step was changed as shown below. The evaluation results of the obtained Toner 4 are shown in Table 5.

[0424] (Cooling process)

[0425] 26.1 kg of deionized water was added to a 50-liter stainless steel drum and cooled to 20.7°C. The cooled deionized water (26.1 kg) and the fused toner particle dispersion (3) (5.6 kg) were fed to a static mixer (model 1 / 4-N30-232-F, manufactured by Noritake Co., Ltd.) at 2.90 kg / min and 0.62 kg / min, respectively, and mixed to cool the toner resin particle dispersion to 27.4°C. The fused toner resin particles were cooled in the pipeline during transportation and had a temperature of 63.5°C at the inlet of the static mixer.

[0426] The static mixer used had 12 stirring blades, a pipe inner diameter of 10.5 mm, and a length of 200 mm. The residence time in the static mixer used was 0.3 seconds.

[0427] Comparative Example 1

[0428] Toner 5 was obtained in the same manner as in Example 1 except that the cooling step was changed as shown below. The evaluation results of the obtained Toner 5 are shown in Table 5.

[0429] (Cooling process)

[0430] 6.8 kg of deionized water was added to a 20-liter container and cooled to 7.7°C. While stirring the cooled deionized water, 3.0 kg of the dispersion (3) of the toner resin particles fused at 71°C was added to the cooled deionized water at a rate of 18 kg / min over 10 seconds and stirred until the dispersion of the toner particles was cooled to 27°C. Note that in Comparative Example 1, the mixing transport time was set to 10 seconds, the stirring time after mixing was set to 10 seconds, and the processing time (retention time) was set to 20 seconds.

[0431] Reference Example 1

[0432] Toner 6 was obtained in the same manner as in Example 2 except that the drying step was changed as shown below. Table 5 shows the evaluation results of the obtained Toner 6.

[0433] (Drying process)

[0434] Using a fluidized bed type dryer (AGM-2PJ manufactured by HOSOKAWA MICRON Corporation), drying was performed for 1 hour under conditions of an inlet air volume of 0.75 m 3 / min and an in-dryer temperature of 30°C to produce toner 6.

[0435] [Table 5]

[0436]

[0437] Industrial Applicability

[0438] The resin particles in the resin particle dispersion liquid obtained by the production method of the present application are suitably used as an electrostatic image developing toner excellent in low-temperature fixing property.

Claims

1. A method for producing a resin particle dispersion for toner, The method comprises the steps of flowing a resin particle dispersion containing an amorphous resin and a crystalline resin together with an aqueous medium, continuously mixing the mixture, and continuously discharging the mixture to cool the mixture. The cooling process uses an apparatus having two or more inlets and one or more outlets, and the cooling rate of the cooling process is 20°C / second or more. The cooling step is a step of cooling the resin particle dispersion to 20° C. or higher.

2. The method for producing a resin particle dispersion for toner according to claim 1, wherein: The cooling step is a step of using a static mixer to flow the resin particle dispersion and the aqueous medium together, continuously mixing them, and continuously discharging the mixture.

3. The method for producing a resin particle dispersion for toner according to claim 2, wherein: The average residence time in the static mixer was less than 3 seconds.

4. The method for producing a resin particle dispersion for toner according to claim 2 or 3, wherein: The average residence time in the static mixer is 0.1 seconds or more and 3 seconds or less.

5. The method for producing a resin particle dispersion for toner according to claim 2 or 3, wherein: The average residence time in the static mixer is 0.1 seconds or more and 2 seconds or less.

6. The method for producing a resin particle dispersion for toner according to claim 2 or 3, wherein: The average residence time in the static mixer is 0.15 seconds or more and 2 seconds or less.

7. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling rate in the cooling step is 20° C. / second or higher and 500° C. / second or lower.

8. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling rate in the cooling step is 30° C. / second or higher and 300° C. / second or lower.

9. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling rate in the cooling step is 60° C. / second or higher and 200° C. / second or lower.

10. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling step is a step of cooling the resin particle dispersion to a temperature of 20° C. or higher and 80° C. or lower.

11. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling step is a step of cooling the resin particle dispersion to a temperature of 30° C. or higher and 80° C. or lower.

12. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The cooling step is a step of cooling the resin particle dispersion to a temperature of 40° C. or higher and 70° C. or lower.

13. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion before cooling is the melting point of the crystalline resin - 18°C ​​or higher, and the temperature of the resin particle dispersion after cooling is the melting point of the crystalline resin - 20°C or lower.

14. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion before cooling is not less than the melting point of the crystalline resin -18°C and not more than the melting point of the crystalline resin +30°C.

15. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion before cooling is not less than the melting point of the crystalline resin -15°C and not more than the melting point of the crystalline resin +30°C.

16. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion before cooling is not less than the melting point of the crystalline resin -15°C and not more than the melting point of the crystalline resin +20°C.

17. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion after cooling is not less than the melting point of the crystalline resin - 80°C and not more than the melting point of the crystalline resin - 20°C.

18. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion after cooling is not less than the melting point of the crystalline resin - 80°C and not more than the melting point of the crystalline resin - 30°C.

19. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The temperature of the resin particle dispersion after cooling is not less than the melting point of the crystalline resin - 60°C and not more than the melting point of the crystalline resin - 30°C.

20. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The mixing ratio of the aqueous medium to the resin particle dispersion, that is, aqueous medium / resin particle dispersion, is 1 / 1 or more and 10 / 1 or less.

21. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The mixing ratio of the aqueous medium to the resin particle dispersion, that is, aqueous medium / resin particle dispersion, is 1.5 / 1 or more and 10 / 1 or less.

22. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The mixing ratio of the aqueous medium to the resin particle dispersion, that is, aqueous medium / resin particle dispersion, is 1.5 / 1 or more and 5 / 1 or less.

23. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: In the cooled resin particles, that is, the resin particles in the resin particle dispersion before cooling, the mass ratio of the amorphous resin to the crystalline resin, that is, amorphous resin / crystalline resin is 50 / 50 or more and 95 / 5 or less.

24. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: In the cooled resin particles, that is, the resin particles in the resin particle dispersion before cooling, the mass ratio of the amorphous resin to the crystalline resin, that is, amorphous resin / crystalline resin is 55 / 45 or more and 90 / 10 or less.

25. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: In the cooled resin particles, that is, the resin particles in the resin particle dispersion before cooling, the mass ratio of the amorphous resin to the crystalline resin, that is, amorphous resin / crystalline resin is 60 / 40 or more and 85 / 15 or less.

26. The method for producing a resin particle dispersion for toner according to claim 1 or 2, wherein: The resin particle dispersion before cooling is a dispersion of fused particles obtained in steps 1 and 2. The step 1 is a step of agglomerating the amorphous resin and the crystalline resin in an aqueous medium to obtain a dispersion of aggregated particles. The step 2 is a step of heating and fusing the obtained aggregated particles in an aqueous medium to obtain a dispersion of fused particles. 27 . A method for producing a toner for electrostatic image development, comprising the method according to claim 1 .

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