JP2020003717A - Method for producing toner for electrostatic charge image development - Google Patents

Abstract

To provide a method for producing a toner for electrostatic charge image development which is excellent in low temperature fixability and charging performance maintenance ratio.SOLUTION: A method for producing a toner for electrostatic charge image development includes: a step of mixing resin particles X containing a composite resin A and a crystalline polyester resin C in the same or different resin particles with an oxazoline group-containing polymer, and heating the mixture at a temperature equal to or higher than the melting point of the crystalline polyester resin C; a step of aggregating the resin particles X in an aqueous medium to obtain aggregated particles; and a step of fusing the obtained aggregated particles at a temperature lower than the melting point of the crystalline polyester resin C by 10°C or more, in which the composite resin A contains a polyester resin segment that is a polycondensate of an alcohol component and a carboxylic acid component and a vinyl-based resin segment that is an addition polymer of a raw material monomer containing a styrenic compound, an amount of the oxazoline group-containing polymer to be added is 0.02 equivalent or more as a mol number (Oxz equivalent) of oxazoline groups of the oxazoline group-containing polymer to the mol number of the acid groups of the composite resin A and the crystalline polyester resin C.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a toner for developing an electrostatic image used for developing a latent image formed in electrophotography, electrostatic recording, electrostatic printing, and the like.

  In the field of electrophotography, with the development of electrophotographic systems, development of toner for electrophotography that supports high image quality and high speed has been demanded. As a method of obtaining a toner having a narrow particle size distribution, a small particle size, and a fixing property capable of coping with high speed in response to high image quality, fine resin particles and the like are aggregated and fused in an aqueous medium. 2. Description of the Related Art A so-called chemical toner is manufactured by an aggregation-fusion method (emulsion aggregation method or aggregation coalescence method) for obtaining a toner.

  Patent Document 1 discloses an electrostatic image developing toner containing a polyester resin and a styrene-acryl-modified polyester resin, wherein a carboxyl group present in the styrene-acryl-modified polyester resin has an oxazoline group, a glycidyl group, or an aziridine group. And a toner for developing an electrostatic image, wherein the toner is modified with a compound having at least one substituent selected from the group consisting of carbodiimide groups. Is described.

  Patent Document 2 discloses a process (1) of emulsifying a resin containing a polyester (a) having at least an acid group to obtain resin particles (A), and coagulating the resin particles (A) in an aqueous medium, Step (2) of obtaining the aggregated particles (I), the resin particles (C) containing an amorphous polyester (c) having at least an acid group and having a glass transition temperature of 55 ° C. or higher are mixed with the aggregated particles (I). A) aggregating the particles on the surface to obtain agglomerated particles (II); and (a) transferring the agglomerated particles (II) from the glass transition temperature of the amorphous polyester (c) −5 ° C. to the glass transition temperature + 10 ° C. A process of fusing the agglomerated particles (II) to obtain core-shell particles while maintaining the temperature in a range of 4 ° C., and obtaining a core-shell particle. , A polymer containing at least two oxazoline groups Adding the compound in a range where the number of moles of the oxazoline group of the polymer compound is 0.02 equivalent or more and 0.45 equivalent or less with respect to the number of moles of the acid group in the polyester (a); A method for producing an electrophotographic toner, wherein the difference in solubility parameter (SP value) between (a) and the amorphous polyester (c) by the Fedors method is 0.6 or more and less than 1.8 is described. According to this method, it is described that an electrophotographic toner having excellent heat resistance storage stability and maintaining a high charge amount even after continuous printing can be manufactured.

  Patent Document 3 discloses a step (A) of neutralizing a resin containing a polyester having an acid group in an aqueous medium to obtain a resin particle dispersion, and the resin particle dispersion obtained in the step (A). And a polymer having an oxazoline group at a temperature of 60 to 100 ° C, and a crosslinked resin having a volume median particle diameter (D50) of 0.05 to 0.7 µm. A particle dispersion and an electrophotographic toner obtained by aggregating and coalescing crosslinked resin particles in the dispersion of the crosslinked resin particles are described. It is described that the toner has excellent low-temperature fixability, hot offset resistance, and image characteristics.

JP 2013-160807 A JP 2015-125406 A JP 2009-79207 A

In recent years, the speed of the electrophotographic system has been remarkably increased compared to the toners of Patent Literatures 1 to 3, and therefore, further improvement in low-temperature fixability of the toner is required. For example, there is a method in which a polyester excellent in low-temperature fixing is used as a toner binder, and a crystalline polyester resin that can be melted at a low temperature is further compounded.
However, if the crystalline polyester resin is present in the vicinity of the surface, it adversely affects the chargeability of the toner, so it is required to be present inside the toner particles.
Even when the crystalline polyester resin is present inside the toner particles as described above, the crystalline polyester resin inside the toner remains in the toner when the toner is transported or after the toner temperature rises inside the printer or copier. A phenomenon was found in which the particles moved to the vicinity of the surface and markedly reduced the chargeability.
The present invention relates to a method for producing a toner for developing an electrostatic image, which is excellent in low-temperature fixability and excellent in a charging performance maintenance ratio.

In order to solve such a problem, the present inventor mixes and heats the resin particles X before aggregation with an oxazoline group-containing polymer, and further adjusts the fusion temperature after aggregation to a predetermined range, so that the low-temperature fixing property is improved. It has been found that a toner for developing an electrostatic image, which is excellent and has an excellent charging performance maintenance ratio, can be obtained.
In the present invention, a resin particle X containing the composite resin A and the crystalline polyester resin C in the same or different resin particles, and an oxazoline group-containing polymer are mixed and heated at a temperature equal to or higher than the melting point of the crystalline polyester resin C. Process,
Aggregating the resin particles X in an aqueous medium to obtain aggregated particles, and
Including a step of fusing the obtained aggregated particles at a temperature of 10 ° C. or lower than the melting point of the crystalline polyester resin C,
The composite resin A includes a polyester resin segment that is a polycondensate of an alcohol component and a carboxylic acid component, and a vinyl resin segment that is an addition polymer of a raw material monomer containing a styrene compound,
The amount of the oxazoline group-containing polymer to be added is 0.1 as the number of moles (Oxz equivalent) of the oxazoline group of the oxazoline group-containing polymer relative to the number of moles of the acid groups in the composite resin A and the crystalline polyester resin C. The present invention relates to a method for producing an electrostatic image developing toner having an equivalent of 02 equivalent or more.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrostatic image developing toner which is excellent in low-temperature fixability and is excellent in charge performance maintenance rate can be provided.

[Production method of toner for developing electrostatic image]
The method for producing a toner for developing an electrostatic image of the present invention (hereinafter, also simply referred to as “toner”) includes:
Mixing resin particles X containing the composite resin A and the crystalline polyester resin C in the same or different resin particles, and an oxazoline group-containing polymer, and heating the mixture at a temperature equal to or higher than the melting point of the crystalline polyester resin C;
Aggregating the resin particles X in an aqueous medium to obtain aggregated particles, and
A step of fusing the obtained aggregated particles at a temperature of at least 10 ° C. lower than the melting point of the crystalline polyester resin C.
The composite resin A includes a polyester resin segment which is a polycondensate of an alcohol component and a carboxylic acid component, and a vinyl resin segment which is an addition polymer of a raw material monomer containing a styrene compound.
Further, the addition amount of the oxazoline group-containing polymer is 0.02 equivalent as the number of moles of oxazoline groups of the oxazoline group-containing polymer (Oxz equivalent) with respect to the number of moles of acid groups in the composite resin A and the crystalline polyester resin C. That is all.
According to the above-described method, a toner having excellent low-temperature fixability and excellent charge performance maintenance ratio can be obtained.

The reason is not clear, but is considered as follows.
A toner containing a crystalline polyester resin inside the toner particles is excellent in low-temperature fixability. However, in a state in which the temperature of the toner rises and the resin constituting the toner tends to soften, the force of agglomeration of the resin molecules acts, so that the crystalline polyester resin exerts a force in a direction of pushing it from the inside to the outside. In addition, the crystalline polyester resin moves to or near the surface of the toner particles, and the chargeability of the toner decreases.
In contrast, by adding an oxazoline group-containing polymer to the inside of the toner particles to form a crosslinked structure, it is possible to inhibit the movement of the crystalline polyester resin, and as a result, the chargeability of the toner deteriorates. It is thought to lead to suppression.
Further, it is considered that, by heating under a predetermined condition to further form a crosslinked structure in the fusion step, the movement of the crystalline polyester resin is more strongly inhibited, and the charging performance retention rate can be improved.

The definitions of various terms in this specification are shown below.
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 endothermic peak temperature (softening point (° C.) / Endothermic maximum peak temperature (° C.)) in the measuring method described in Examples described later. The crystalline resin has a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one having a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted depending on the kind and ratio of the raw material monomers, and the production conditions such as the reaction temperature, the reaction time, and the cooling rate.
In the specification, the carboxylic acid component of the polyester resin includes not only the compound, but also an anhydride which is decomposed during the reaction to generate an acid, and an alkyl ester of each carboxylic acid (the alkyl group has 1 to 3 carbon atoms). Is also included.
The “volume median particle size D ₅₀ ” is a particle size at which the cumulative volume frequency calculated by the volume fraction becomes 50% calculated from the smaller particle size.
The variation coefficient of the particle size distribution (hereinafter, also simply referred to as “CV value”) is a value represented by the following equation. The volume average particle size in the following formula is a particle size obtained by multiplying a particle size measured on a volume basis by a ratio of particles having the particle size value, and dividing a value obtained thereby by the number of particles. is there.
CV value (%) = [standard deviation of particle size distribution (μm) / volume average particle size (μm)] × 100

The method for producing a toner according to one embodiment of the present invention includes, for example, mixing a resin particle X containing a composite resin A and a crystalline polyester resin C in the same or different resin particles, and an oxazoline group-containing polymer, Heating at a temperature equal to or higher than the melting point of the hydrophilic polyester resin C (hereinafter, also referred to as “step (1)”);
A step of aggregating the resin particles X in an aqueous medium to obtain aggregated particles 1 (hereinafter, also referred to as “step (2)”);
A step of adhering the resin particles Y containing the amorphous polyester-based resin B to the aggregated particles 1 to obtain aggregated particles 2 (hereinafter, also referred to as “step (3)”), and
A step of fusing the obtained aggregated particles 2 at a temperature of 10 ° C. or lower than the melting point of the crystalline polyester resin C (hereinafter, also referred to as “step (4)”).
Hereinafter, the present invention will be described using the embodiment as an example.

<Step (1)>
In order to obtain excellent low-temperature fixability, the resin particles X preferably include the composite resin A and the crystalline polyester resin C in the same or different resin particles, and from the viewpoint of further improving the low-temperature fixability and the charge performance maintenance ratio, , A composite resin A and a crystalline polyester resin C in the same resin particle.

≪Composite resin A≫
The composite resin A is excellent in low-temperature fixability, and from the viewpoint of obtaining a toner excellent in the charging performance maintenance ratio, a polyester resin segment which is a polycondensate of an alcohol component and a carboxylic acid component, and a raw material monomer containing a styrene compound. A vinyl resin segment which is an addition polymer.
The composite resin A is preferably an amorphous composite resin A.

Examples of the alcohol component include an aromatic diol, a linear or branched aliphatic diol, an alicyclic diol, and a trihydric or higher polyhydric alcohol. Of these, aromatic diols are preferred.
The aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably of formula (I):

(Wherein OR ¹ and R ² O are oxyalkylene groups, R ¹ and R ² are each independently an ethylene group or a propylene group, and x and y represent the average number of moles of alkylene oxide added. And the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, and more preferably 4 or less. It is an oxide adduct.
Examples of the alkylene oxide adduct of bisphenol A include a propylene oxide adduct of bisphenol A [2,2-bis (4-hydroxyphenyl) propane] and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination of two or more. Among these, a propylene oxide adduct of bisphenol A is preferable.
The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably at least 70 mol%, more preferably at least 90 mol%, still more preferably at least 95 mol%, and is at most 100 mol%, More preferably, it is 100 mol%.

Examples of the linear or branched aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. , 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, , 12-dodecanediol.
Examples of the alicyclic diol include hydrogenated bisphenol A [2,2-bis (4-hydroxycyclohexyl) propane] and alkylene oxide adducts of hydrogenated bisphenol A having 2 to 4 carbon atoms (average addition mole 2 12 or less).
Examples of the trihydric or higher polyhydric alcohol include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.
One or more of these alcohol components may be used.

Examples of the carboxylic acid component include dicarboxylic acids and trivalent or higher polycarboxylic acids.
Examples of the dicarboxylic acid include an aromatic dicarboxylic acid, a linear or branched aliphatic dicarboxylic acid, and an alicyclic dicarboxylic acid. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferable.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferable, and terephthalic acid is more preferable.
The amount of the aromatic dicarboxylic acid in the carboxylic acid component is preferably at least 20 mol%, more preferably at least 30 mol%, further preferably at least 40 mol%, further preferably at least 50 mol%, and preferably at least 50 mol%. It is 90 mol% or less, more preferably 85 mol% or less, and still more preferably 80 mol% or less.

The carbon number of the linear or branched aliphatic dicarboxylic acid is preferably 2 or more, more preferably 3 or more, and preferably 30 or less, more preferably 20 or less.
Examples of the linear or branched aliphatic dicarboxylic acids include, for example, 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 aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, fumaric acid, sebacic acid, and succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms are preferable.
The amount of the linear or branched aliphatic dicarboxylic acid in the carboxylic acid component is preferably at least 1 mol%, more preferably at least 3 mol%, still more preferably at least 5 mol%, and preferably at least 80 mol%. Or less, more preferably 50 mol% or less, further preferably 30 mol% or less.

The trivalent or higher polycarboxylic acid is preferably a trivalent carboxylic acid, for example, trimellitic acid. Preferably, trimellitic acid or its anhydride is used.
When a polycarboxylic acid having a valence of 3 or more is contained, 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, and still more preferably 8 mol% in the carboxylic acid component. It is at least 30 mol%, more preferably 25 mol% or less, further preferably 20 mol% or less.
One or more of these carboxylic acid components may be used.

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

The addition polymer resin segment is, for example, an addition polymer of a raw material monomer containing a styrene compound.
Examples of the styrene compound include unsubstituted and substituted styrene. Examples of the substituent substituted with styrene 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, and a salt thereof.
Examples of the styrene-based compound include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid and salts thereof. Of these, styrene is preferred.
The content of the styrene compound in the raw material monomer of the addition polymerization resin segment is preferably 50% by mass or more, more preferably 65% by mass or more, further preferably 75% by mass or more, and 100% by mass or less. , Preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less.

Raw material monomers other than styrene compounds include, for example, (meth) acrylates such as alkyl (meth) acrylate, benzyl (meth) acrylate and dimethylaminoethyl (meth) acrylate; ethylene, propylene, butadiene and the like. Olefins; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. . Of these, (meth) acrylates are preferred, and alkyl (meth) acrylates are more preferred.
The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably 1 or more, more preferably 6 or more, and still more preferably 10 or more, and preferably 24 or less, more preferably 22 or less, and still more preferably 20 or more. It is as follows.
Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, (iso or tertiary) butyl (meth) acrylate, and (meth) alkyl. ) (Iso) amyl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) decyl (meth) acrylate, (meth) acrylic acid ( Iso) dodecyl, (iso) palmityl (meth) acrylate, (iso) stearyl (meth) acrylate, (iso) behenyl (meth) acrylate, and the like, and 2-ethylhexyl (meth) acrylate or (meth) acrylate. Stearyl acrylate is preferred, and stearyl (meth) acrylate is more preferred.
Note that “(iso or tertiary)” and “(iso)” mean both the case where these prefixes are present and the case where these prefixes are not present, and indicate the case where these prefixes are not present. Further, “(meth) acrylic acid” indicates acrylic acid or methacrylic acid.

  The content of the (meth) acrylate in the raw material monomer of the addition polymerization resin segment is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and preferably 50% by mass or more. It is at most 35 mass%, more preferably at most 35 mass%, even more preferably at most 25 mass%.

  The total amount of the styrene compound and the (meth) acrylate in the raw material monomer of the addition polymerization resin segment is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and still more preferably. Is 100% by mass.

The composite resin preferably has a structural unit derived from a bi-reactive monomer bonded to the polyester resin segment and the addition-polymerized resin segment via a covalent bond.
The “structural unit derived from a bi-reactive monomer” means a unit in which a functional group and an addition-polymerizable group of the bi-reactive monomer have reacted.
Examples of the addition-polymerizable group include a carbon-carbon unsaturated bond.
Examples of the amphoteric monomer include an addition polymerizable monomer having at least one functional group selected from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule. . Among these, from the viewpoint of reactivity, an addition polymerizable monomer having at least one functional group selected from a hydroxyl group and a carboxy group is preferable, and an addition polymerizable monomer having a carboxy group is more preferable.
Examples of the addition-polymerizable monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred, from the viewpoint of the reactivity of both the polycondensation reaction and the addition polymerization reaction.
The amount of the structural unit derived from the amphoteric monomer is preferably 1 mol part or more, more preferably 5 mol parts or more, and still more preferably 8 mol parts, based on 100 mol parts of the alcohol component of the polyester resin segment of the composite resin A. And it is preferably at most 30 mol parts, more preferably at most 25 mol parts, even more preferably at most 20 mol parts.

  The content of the polyester resin segment in the composite resin A is preferably 35% by mass or more, more preferably 45% by mass or more, even more preferably 50% by mass or more, and preferably 90% by mass or less, more preferably It is at most 85% by mass, more preferably at most 75% by mass.

  The content of the addition polymerization resin segment in the composite resin A is preferably 5% by mass or more, more preferably 15% by mass or more, still more preferably 25% by mass or more, and preferably 60% by mass or less, more preferably Is 55% by mass or less, more preferably 45% by mass or less.

  The amount of the structural unit derived from the amphoteric monomer in the composite resin A is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and It is preferably at most 10% by mass, more preferably at most 5% by mass, still more preferably at most 3% by mass.

  In the composite resin A, the total amount of the structural units derived from the polyester resin segment, the addition polymerization resin segment, and the amphoteric monomer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. And 100% by mass or less, and more preferably 100% by mass.

The composite resin A may be produced, for example, by a method including a step A of polycondensing an alcohol component and a carboxylic acid component, and a step B of addition polymerization of a raw material monomer and a bi-reactive monomer of an addition-polymerized resin segment.
Step B may be performed after step A, step A may be performed after step B, and step A and step B may be performed simultaneously.
In the step A, a part of the carboxylic acid component is subjected to a polycondensation reaction, and then, after the step B is carried out, the remainder of the carboxylic acid component is added to the polymerization system. Preferred is a method for further promoting the reaction with the reactive monomer.

In the step A, if necessary, an esterification catalyst such as tin (II) di (2-ethylhexanoate), dibutyltin oxide, titanium diisopropylate bistriethanolaminate may be used in a total amount of alcohol component and carboxylic acid component of 100%. 0.01 parts by mass or more and 5 parts by mass or less with respect to parts by mass; esterification promoter such as gallic acid (same as 3,4,5-trihydroxybenzoic acid) or the like in total of 100 parts by mass of alcohol component and carboxylic acid component The polycondensation may be performed using 0.001 parts by mass or more and 0.5 parts by mass or less with respect to parts.
When using a monomer having an unsaturated bond such as fumaric acid for the polycondensation, preferably 0.001 part by mass or more based on 100 parts by mass of the total of the alcohol component and the carboxylic acid component as necessary. 0.5 parts by mass or less of a radical polymerization inhibitor may be used. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol.
The temperature of the polycondensation reaction is preferably 120 ° C. or higher, more preferably 160 ° C. or higher, further preferably 180 ° C. or higher, and preferably 250 ° C. or lower, more preferably 240 ° C. or lower. The polycondensation may be performed in an inert gas atmosphere.

Examples of the radical polymerization initiator for the addition polymerization in the step B include peroxides such as dibutyl peroxide, persulfates such as sodium persulfate, and 2,2′-azobis (2,4-dimethylvaleronitrile). An azo compound is exemplified.
The amount of the radical polymerization initiator used is preferably 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the raw material monomer of the addition polymerization resin segment.
The temperature of the addition polymerization is preferably 110 ° C. or higher, more preferably 130 ° C. or higher, and is preferably 230 ° C. or lower, more preferably 220 ° C. or lower, and further preferably 210 ° C. or lower.

(Physical properties of composite resin A)
The softening point of the composite resin A is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, and further preferably 100 ° C. or higher, from the viewpoint of further improving the charging performance retention rate, and further improves low-temperature fixability. From the viewpoint, the temperature is preferably 150 ° C. or lower, more preferably 140 ° C. or lower, and further preferably 125 ° C. or lower.
The glass transition temperature of the composite resin A is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, and still more preferably 40 ° C. or higher, from the viewpoint of further improving the charging performance retention rate, and further improves low-temperature fixability. From the viewpoint of performing the heating, the temperature is preferably 80 ° C or lower, more preferably 70 ° C or lower, and further preferably 60 ° C or lower.

The acid value of the composite resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, and preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less. More preferably, it is 30 mgKOH / g or less.
The softening point, glass transition temperature, and acid value of the composite resin A can be appropriately adjusted depending on the type of the raw material monomer and the amount used, and the reaction temperature, reaction time, production conditions such as cooling rate, and the like. The value is determined by the method described in the examples.
When two or more composite resins A are used in combination, the softening point, glass transition temperature, and acid value obtained as a mixture thereof are preferably within the above ranges.

  The content of the composite resin A is preferably at least 40% by mass, more preferably at least 50% by mass, even more preferably at least 60% by mass with respect to the total amount of the resin components of the resin particles X, and preferably It is 95% by mass or less, more preferably 90% by mass or less, further preferably 85% by mass or less, further preferably 80% by mass or less, and still more preferably 75% by mass or less.

<< Crystalline polyester resin C >>
The crystalline polyester resin C is a polycondensate of an alcohol component and a carboxylic acid component.
As the alcohol component, α, ω-aliphatic diol is preferable.
The carbon number of the α, ω-aliphatic diol is preferably 2 or more, more preferably 4 or more, still more preferably 6 or more, and preferably 16 or less, more preferably 14 or less, and still more preferably 12 or less. is there.
Examples of the α, ω-aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol and 1,14-tetradecanediol No. Among these, 1,6-hexanediol, 1,10-decanediol and 1,12-dodecanediol are preferred, and 1,10-decanediol is more preferred.

  The amount of the α, ω-aliphatic diol is preferably at least 80 mol%, more preferably at least 85 mol%, still more preferably at least 90 mol%, still more preferably at least 95 mol% in the alcohol component, and Mol% or less, more preferably 100 mol%.

  The alcohol component may contain another alcohol component different from the α, ω-aliphatic diol. Other alcohol components include, for example, aliphatic diols other than α, ω-aliphatic diols such as 1,2-propanediol and neopentyl glycol; aromatic diols such as alkylene oxide adducts of bisphenol A; glycerin, pentane And trihydric or higher alcohols such as erythritol and trimethylolpropane. One or more of these alcohol components may be used.

As the carboxylic acid component, an aliphatic dicarboxylic acid is preferable, and a linear aliphatic dicarboxylic acid is more preferable.
The carbon number of the aliphatic dicarboxylic acid is preferably 4 or more, more preferably 8 or more, further preferably 10 or more, and preferably 14 or less, more preferably 12 or less.
Examples of the aliphatic dicarboxylic acid include fumaric acid, sebacic acid, dodecandioic acid, and tetradecandioic acid. Among these, sebacic acid and dodecanedioic acid are preferred, and sebacic acid is more preferred. One or more of these carboxylic acid components may be used.

  The amount of the aliphatic dicarboxylic acid in the carboxylic acid component is preferably at least 80 mol%, more preferably at least 85 mol%, further preferably at least 90 mol%, further preferably at least 95 mol%, and %, More preferably 100 mol%.

  The carboxylic acid component may contain another carboxylic acid component different from the aliphatic dicarboxylic acid. Other carboxylic acid components include, for example, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; and trivalent or higher polycarboxylic acids. One or more of these carboxylic acid components may be used.

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

  The method for producing the crystalline polyester resin C includes, for example, the same example as in the step A of the composite resin A described above.

(Physical properties of crystalline polyester resin C)
The softening point of the crystalline polyester resin C is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, further preferably 80 ° C. or higher, from the viewpoint of the storage stability of the toner, and further improves the low-temperature fixability. Therefore, the temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, and still more preferably 100 ° C. or lower.

  The melting point of the crystalline polyester resin C is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and still more preferably 70 ° C. or higher, from the viewpoint of storability of the toner, and from the viewpoint of further improving low-temperature fixability. , Preferably 100 ° C or lower, more preferably 90 ° C or lower, still more preferably 80 ° C or lower.

  The acid value of the crystalline polyester resin C is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and preferably 35 mgKOH / g or less, more preferably 25 mgKOH / g or less, and still more preferably 20 mgKOH / g. It is as follows.

  The softening point, melting point, and acid value of the crystalline polyester resin C can be appropriately adjusted by the kind of the raw material monomer and the amount used, and the reaction temperature, reaction time, cooling rate, and other production conditions. Is determined by the method described in (1). When two or more crystalline polyester resins C are used in combination, the values of the softening point, melting point, and acid value obtained as a mixture thereof are preferably within the above ranges.

  The content of the crystalline polyester resin C is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and still more preferably 20% by mass or more, based on the total amount of the resin components of the resin particles X. It is at least 25 mass%, more preferably at least 25 mass%, and preferably at most 50 mass%, more preferably at most 45 mass%, even more preferably at most 40 mass%.

  The mass ratio of the crystalline polyester resin C to the composite resin A in the resin particles X [crystalline polyester resin C / composite resin A] is determined based on the viewpoint of further improving the low-temperature fixability and the steps (1) and (4). ) From the viewpoint of enhancing the effect of (1) and obtaining a better charging performance retention rate, preferably 5/95 or more, more preferably 10/90 or more, further preferably 15/85 or more, further preferably 20/80 or more, and It is preferably at least 25/75, and more preferably at most 60/40, more preferably at most 50/50, even more preferably at most 45/55, even more preferably at most 40/60.

  The total amount of the composite resin A and the crystalline polyester resin C is preferably at least 70% by mass, more preferably at least 80% by mass, further preferably at least 90% by mass, based on the total amount of the resin component of the resin particles X. , More preferably 95% by mass or more, and 100% by mass or less, and more preferably 100% by mass.

<< Method of manufacturing resin particles X >>
A dispersion of the resin particles X is obtained by dispersing the composite resin A in an aqueous medium. The crystalline polyester resin C may be simultaneously dispersed to form resin particles X containing the crystalline polyester resin C, or resin particles Xa containing the composite resin A and resin particles Xb containing the crystalline polyester resin C. May be used. The dispersion of the resin particles Xa and Xb can also be obtained by the same method as the following method for producing the dispersion of the resin particles.
As the aqueous medium, those containing water as a main component are preferable, and from the viewpoint of improving the dispersion stability of the dispersion liquid of the resin particles, and from the viewpoint of environmental friendliness, the content of water in the aqueous medium is preferably 80 mass%. % Or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and 100% by mass or less, further preferably 100% by mass. As the water, deionized water or distilled water is preferable. Components other than water that can be contained in the aqueous medium include, for example, alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms such as acetone and methyl ethyl ketone; and water soluble such as cyclic ethers such as tetrahydrofuran. Organic solvent.

  Dispersion can be performed using a known method, but it is preferable to perform dispersion by a phase inversion emulsification method. The phase inversion emulsification method includes, for example, a method in which an aqueous medium is added to an organic solvent solution of a resin or a molten resin to carry out phase inversion emulsification.

The organic solvent used for phase inversion emulsification is not particularly limited as long as it dissolves the resin. From the viewpoint of facilitating phase inversion, for example, alcohol solvents such as ethanol, isopropanol and isobutanol; acetone, methyl ethyl ketone and methyl isobutyl ketone And ether solvents such as dibutyl ether, tetrahydrofuran and dioxane; and acetate solvents such as ethyl acetate and isopropyl acetate. Among these, ketone solvents and acetate solvents are preferable, and methyl ethyl ketone, ethyl acetate, and isopropyl acetate are more preferable, from the viewpoint of easy removal from the mixed solution after the addition of the aqueous medium.
It is preferable to add a neutralizing agent to the organic solvent solution. Examples of the neutralizing agent include basic substances. Examples of the basic substance include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine and diethanolamine.
The equivalent (mol%) of the neutralizing agent to the acid group of the resin contained in the resin particles X is preferably 10 mol% or more, more preferably 30 mol% or more, further preferably 40 mol% or more, and It is preferably at most 90 mol%, more preferably at most 70 mol%.
In addition, the use equivalent (mol%) of a neutralizing agent can be calculated | required by the following formula. When the equivalent of the neutralizing agent is 100 mol% or less, it has the same meaning as the degree of neutralization.
Equivalent weight (mol%) of neutralizing agent = [{weight of neutralizing agent added (g) / equivalent weight of neutralizing agent] / [{weighted average acid value of resin constituting resin particle X (mg KOH / g) × Mass of resin constituting resin particles X (g)｝ / (56 × 1000)]] × 100

While stirring the organic solvent solution or the molten resin, an aqueous medium is gradually added to cause phase inversion.
From the viewpoint of improving the dispersion stability of the resin particles X, the temperature of the organic solvent solution at the time of adding the aqueous medium is preferably equal to or higher than the glass transition temperature of the resin constituting the resin particles X, more preferably equal to or higher than 50 ° C, and still more preferably. Is 60 ° C. or higher, and is preferably 85 ° C. or lower, more preferably 80 ° C. or lower.
The contents of the composite resin A and the crystalline polyester resin C are as described above.

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

The volume median particle diameter (D ₅₀ ) of the resin particles X in the dispersion is preferably 0.05 μm or more, more preferably 0.08 μm or more, from the viewpoint of obtaining a toner capable of obtaining a high-quality image. , Preferably 0.8 μm or less, more preferably 0.4 μm or less, and still more preferably 0.3 μm or less.
The CV value of the resin particles X in the dispersion is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, from the viewpoint of obtaining a toner capable of obtaining a high-quality image. Is 35% or less, more preferably 30% or less.
The volume median particle size (D ₅₀ ) and CV value of the resin particles can be determined by the methods described in Examples described later.

When resin particles Xa containing composite resin A and resin particles Xb containing crystalline polyester resin C are used, resin particles Xa and Xb can be obtained by the same method as described above.
The addition amount of the resin particles Xa and the resin particles Xb is preferably such that the content of the composite resin A and the crystalline polyester resin C is attained.

<< Oxazoline group-containing polymer >>
The oxazoline group-containing polymer is, for example, a polymer of a polymerizable monomer having an oxazoline group.
The oxazoline group-containing polymer may be a polymer of a polymerizable monomer having an oxazoline group and a polymerizable monomer having no oxazoline group.

  Examples of the polymerizable monomer having an oxazoline group include, for example, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl -2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline. Among these, 2-isopropenyl-2-oxazoline is preferred.

Examples of the polymerizable monomer having no oxazoline group include (meth) acrylic acid ester, (meth) acrylic acid or a salt thereof, (meth) acrylonitrile, (meth) acrylamide, vinyl esters such as vinyl acetate, and methyl ester. Examples thereof include vinyl ethers such as vinyl ether, α-olefins such as ethylene and propylene, halogen-containing α, β-unsaturated aliphatic hydrocarbons such as vinyl chloride, and α, β-unsaturated aromatic hydrocarbons such as styrene.
Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, Cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate 2-hydroxypropyl (meth) acrylate, monoester of (meth) acrylic acid and polyethylene glycol, 2-aminoethyl (meth) acrylate or a salt thereof, caprolactone-modified (meth) acrylic acid, (Meth) acrylic acid-2,2,6,6-tetramethylpiperidine (Meth) acrylic acid 1,2,2,6,6-pentamethyl piperidine.
In addition, (meth) acrylic acid means at least one selected from acrylic acid and methacrylic acid.

The content of the oxazoline group in the oxazoline group-containing polymer is preferably 0.1 mmol / g or more, more preferably 0.5 mmol / g or more, further preferably 1 mmol / g or more, and preferably 50 mmol / g. Or less, more preferably 20 mmol / g or less, further preferably 10 mmol / g or less.
The oxazoline value of the oxazoline group-containing polymer is preferably 100 g / eq or more, more preferably 150 g / eq or more, further preferably 200 g / eq or more, and preferably 600 g / eq or less, more preferably 400 g / eq. Or less, more preferably 300 g / eq or less.
The oxazoline value means the mass of the oxazoline group-containing polymer per one molar equivalent of the oxazoline group.
The content of the oxazoline group and the oxazoline value in the oxazoline group-containing polymer can be measured by ¹ H-NMR in CDCl ₃ .

The number average molecular weight of the oxazoline group-containing polymer is preferably 500 or more, more preferably 1,000 or more, and preferably 2,000,000 or less, more preferably 1,000,000 or less, and further preferably It is 100,000 or less, more preferably 50,000 or less.
The number average molecular weight of the oxazoline group-containing polymer is a value measured by gel permeation chromatography using polystyrene as a standard substance.

  Commercially available oxazoline group-containing polymers include, for example, “WS-300”, “WS-500”, “WS-700”, “K-2010E”, “K-2020E”, “K-2020E” of the “Epocross” series. -2030E "(all manufactured by Nippon Shokubai Co., Ltd.).

  In the step (1), the addition amount of the oxazoline group-containing polymer is preferably 0.1 mass with respect to a total of 100 mass parts of the composite resin A and the crystalline polyester resin C from the viewpoint of improving the charging performance maintenance rate. Parts by mass or more, more preferably 0.3 parts by mass or more, still more preferably 0.5 parts by mass or more, still more preferably 0.6 parts by mass or more, and from the viewpoint of improving low-temperature fixability, preferably 4 parts by mass. Parts by mass, more preferably 3 parts by mass or less, further preferably 2.5 parts by mass or less, further preferably 2.0 parts by mass or less, and still more preferably 1.0 parts by mass or less.

In the step (1), the addition amount of the oxazoline group-containing polymer is determined by the number of moles of oxazoline groups of the oxazoline group-containing polymer relative to the number of moles of acid groups in the composite resin A and the crystalline polyester resin C (hereinafter referred to as “Oxz equivalent”). ), From the viewpoint of obtaining a toner having an excellent charging performance maintenance ratio, the amount is 0.02 equivalent or more, preferably 0.05 equivalent or more, more preferably 0.08 equivalent or more, and is excellent in low-temperature fixability. From the viewpoint of obtaining a toner, the amount is preferably 0.55 equivalent or less, more preferably 0.35 equivalent or less, further preferably 0.25 equivalent or less, and further preferably 0.15 equivalent or less.
The Oxz equivalent is calculated by the following equation.

In the method for calculating the Oxz equivalent, the number of moles of the acid groups in the composite resin A and the crystalline polyester resin C is calculated from the acid value of the composite resin A and the crystalline polyester resin C and the amount of each resin added.
When the resin is neutralized, the acid value of the resin is the acid value before neutralization in the method for calculating the Oxz equivalent.
The number of moles of the oxazoline group in the oxazoline group-containing polymer is calculated from the content (mmol / g) and the amount of the oxazoline group in the oxazoline group-containing polymer. The content of the oxazoline group in the oxazoline group-containing polymer can be calculated from the intensity of the peak derived from the oxazoline group in the spectrum obtained by ¹ H-NMR analysis of the oxazoline group-containing polymer.

(Mixing conditions)
In the step (1), a resin particle X containing the composite resin A and the crystalline polyester resin C in the same or different resin particles and an oxazoline group-containing polymer are mixed, and the mixture is heated at a temperature equal to or higher than the melting point of the crystalline polyester resin C. Heat. By heating at a temperature equal to or higher than the melting point of the crystalline polyester resin C, the reaction between the oxazoline group-containing polymer and the crystalline polyester resin C is promoted, and the charging performance retention rate can be improved.
The temperature of the step (1) is preferably at least 5 ° C. higher than the melting point of the crystalline polyester resin C, more preferably at least 10 ° C. higher than the melting point of the crystalline polyester resin C, and still more preferably the crystalline polyester resin. The temperature is at least 15 ° C. higher than the melting point of C, and is preferably at most 10 ° C. higher than the softening point of the composite resin A, more preferably at most 5 ° C. higher than the softening point of the composite resin A, even more preferably. Is below the softening point of the composite resin A.
The heating time in the step (1) is preferably 0.5 hours or more, more preferably 1 hour or more, further preferably 2 hours or more, and preferably 6 hours or less, more preferably 5 hours or less, and further more preferably. Is less than 4 hours.
Here, the heating time is a time during which the temperature is equal to or higher than the melting point of the crystalline polyester resin C.
In the step (1), the mixing method can be performed by a known method.

<Step (2)>
In the step (2), the resin particles X are aggregated in an aqueous medium to obtain aggregated particles 1.

〔Release agent〕
In the step (2), release agent particles containing a release agent may be aggregated together with the resin particles X.
Examples of the release agent include polypropylene wax, polyethylene wax, polypropylene-polyethylene copolymer wax; hydrocarbon waxes such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and Sasol wax or oxides thereof; carnauba wax , Montan wax or their deoxidizing waxes, ester waxes such as fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts. These may be used alone or in combination of two or more.

The melting point of the release agent is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and is preferably 160 ° C. or lower, more preferably 150 ° C. or lower, and even more preferably 140 ° C. or lower.
The content of the release agent in the toner is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 5% by mass or more, and preferably 20% by mass or less, more preferably It is 15% by mass or less.

(Dispersion of release agent particles)
The release agent is preferably contained in the aggregated particles 1 by mixing and aggregating with the resin particles X as a dispersion of release agent particles.
The dispersion liquid of the release agent particles can be obtained by using a surfactant, but is preferably obtained by mixing a release agent and resin particles Z described later. By preparing the release agent particles using the release agent and the resin particles Z, the release agent particles are stabilized by the resin particles Z, and the release agent can be added to the aqueous medium without using a surfactant. It can be dispersed. It is considered that the dispersion of the release agent particles has a structure in which a large number of resin particles Z adhere to the surface of the release agent particles.

  The resin constituting the resin particles Z in which the release agent is dispersed is preferably a polyester resin from the viewpoint of improving the charging performance maintenance ratio, and a composite resin D having a polyester resin segment and an addition polymer resin segment may be used. More preferred.

The softening point of the composite resin D is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and is preferably 140 ° C. or lower, more preferably 120 ° C. or lower, and further preferably 100 ° C. or lower.
The acid value of the composite resin D is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, further preferably 15 mgKOH / g or more, further preferably 20 mgKOH / g or more, and preferably 40 mgKOH / g or less. It is more preferably at most 35 mgKOH / g, even more preferably at most 30 mgKOH / g.

The other preferable ranges of the resin properties of the composite resin D, the preferable examples of the raw material monomers constituting the resin, and the like are the same as those of the example shown for the composite resin A. The dispersion of the resin particles Z can be obtained, for example, by the phase inversion emulsification method described above.
The volume median particle size (D ₅₀ ) of the resin particles Z is preferably 0.01 μm or more, more preferably 0.03 μm or more, and preferably 0.1 μm or more, from the viewpoint of dispersion stability of the release agent particles. It is 3 μm or less, more preferably 0.2 μm or less.
The CV value of the resin particles Z is preferably 10% or more, more preferably 15% or more, and preferably 40% or less, more preferably 35% or less, from the viewpoint of dispersion stability of the release agent particles. It is more preferably at most 30%.

The release agent particle dispersion is, for example, a release agent and a resin particle dispersion and an aqueous medium as needed, at a temperature equal to or higher than the melting point of the release agent, a homogenizer, a high-pressure disperser, an ultrasonic disperser, or the like. It is obtained by dispersing using a disperser.
The heating temperature at the time of dispersion is preferably not less than the melting point of the release agent and not less than 80 ° C, more preferably not less than 85 ° C, still more preferably not less than 90 ° C, and preferably, softening of the resin contained in the resin particles Z. The temperature is less than 10 ° C. higher than the point and 100 ° C. or less, more preferably 98 ° C. or less, and further preferably 95 ° C. or less.

  The amount of the resin particles Z is preferably at least 5 parts by mass, more preferably at least 10 parts by mass, even more preferably at least 20 parts by mass, and preferably at most 100 parts by mass, based on 100 parts by mass of the release agent. , More preferably 70 parts by mass or less, even more preferably 50 parts by mass or less.

The volume median particle diameter (D ₅₀ ) of the release agent particles is preferably 0.05 μm or more, more preferably 0.2 μm or more, and still more preferably 0.4 μm or more, from the viewpoint of obtaining uniform aggregated particles by aggregation. And preferably 1 μm or less, more preferably 0.8 μm or less, and still more preferably 0.6 μm or less.
The CV value of the release agent particles is preferably at least 10%, more preferably at least 20%, and is preferably at most 40%, more preferably at most 35%, even more preferably at most 30%.
The method for measuring the volume median particle diameter (D ₅₀ ) and the CV value of the release agent particles is based on the method described in Examples.

(Colorant)
In the step (2), the colorant particles containing the colorant may be aggregated together with the resin particles X.
As the colorant, all dyes, pigments, and the like used as colorants for toner can be used.
Examples of the coloring agent include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazo yellow. Can be The toner may be either a black toner or a color toner other than black.

  From the viewpoint of improving the image density of the toner, the content of the colorant is preferably at least 1 part by mass, more preferably at least 2 parts by mass, based on 100 parts by mass of the total of the composite resin A and the crystalline polyester resin C. It is more preferably at least 5 parts by mass, even more preferably at least 8 parts by mass, and preferably at most 40 parts by mass, more preferably at most 30 parts by mass, even more preferably at most 20 parts by mass.

(Dispersion of colorant particles)
The colorant is preferably contained in the aggregated particles 1 by mixing and aggregating with the resin particles X as a dispersion of the colorant particles.
The dispersion of the colorant particles is preferably obtained by dispersing the colorant and the aqueous medium using a disperser such as a homogenizer or an ultrasonic disperser. The dispersion is preferably performed in the presence of a surfactant from the viewpoint of improving the dispersion stability of the colorant. Examples of the surfactant include a nonionic surfactant, an anionic surfactant, and a cationic surfactant. From the viewpoint of improving the dispersion stability of the colorant particles, preferably the anionic surfactant is used. Agent. Examples of the anionic surfactant include dodecylbenzene sulfonate, dodecyl sulfate, lauryl ether sulfate, and alkenyl succinate. Of these, dodecylbenzene sulfonate is preferred.

  The content of the surfactant in the dispersion of the colorant particles is preferably 1 part by mass or more, more preferably 5 parts by mass, based on 100 parts by mass of the colorant, from the viewpoint of improving the dispersion stability of the colorant. As mentioned above, it is more preferably at least 10 parts by mass, and preferably at most 40 parts by mass, more preferably at most 30 parts by mass.

The volume median particle size (D ₅₀ ) of the colorant particles is preferably at least 0.05 μm, more preferably at least 0.08 μm, still more preferably at least 0.1 μm, and preferably at most 0.3 μm, Preferably it is 0.2 μm or less.
The method for measuring the volume median particle size (D ₅₀ ) of the colorant particles is based on the method described in Examples.

  The agglomerated particles 1 may further contain additives such as a charge control agent, a magnetic powder, a fluidity improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, an antioxidant, and a cleanability improver. May be included.

(Surfactant)
In the step (2), the resin particles X are preferably aggregated after preparing the mixed dispersion.
When preparing the mixed dispersion, the mixed dispersion may be prepared in the presence of a surfactant from the viewpoint of improving the dispersion stability of the resin particles X and optional components such as wax particles added as necessary. Examples of the surfactant include an anionic surfactant such as an alkyl benzene sulfonate and an alkyl ether sulfate; and a nonionic surfactant such as a polyoxyethylene alkyl ether and a polyoxyethylene alkenyl ether.
When a surfactant is used, its amount is preferably at least 0.1 part by mass, more preferably at least 0.5 part by mass, and preferably at least 10 parts by mass, based on 100 parts by mass of the resin particles X. Or less, more preferably 5 parts by weight or less, and still more preferably 3 parts by weight or less.

  The above-mentioned dispersion of the resin particles X and the mixing of the optional components are performed by a conventional method. It is preferable to add an aggregating agent to the mixed dispersion obtained by the mixing from the viewpoint of efficiently performing aggregation.

  Examples of the coagulant include cationic surfactants of quaternary salts, organic coagulants such as polyethyleneimine; inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate; ammonium sulfate, chloride Inorganic ammonium salts such as ammonium and ammonium nitrate; and inorganic coagulants such as divalent or higher metal complexes. From the viewpoint of improving cohesiveness and obtaining uniform aggregated particles, a monovalent to pentavalent inorganic coagulant is preferable, a monovalent to divalent inorganic metal salt and an inorganic ammonium salt are more preferable, and ammonium sulfate is still more preferable. .

  Using a coagulant, for example, a mixed dispersion containing resin particles X at 0 ° C. or higher and 40 ° C. or lower, and adding 5 to 50 parts by mass of a coagulant to 100 parts by mass of resin particles X, X is aggregated in an aqueous medium to obtain aggregated particles 1. Further, from the viewpoint of promoting coagulation, it is preferable to increase the temperature of the dispersion after adding the coagulant.

The volume median particle diameter (D ₅₀ ) of the aggregated particles 1 is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less. The volume median particle size (D ₅₀ ) of the aggregated particles 1 is determined by a method described in Examples described later.

<Step (3)>
In the step (3), the resin particles Y containing the amorphous polyester resin B are attached to the aggregated particles 1 to obtain the aggregated particles 2.
[Resin particles Y]
The dispersion of the resin particles Y can be obtained by the same method as the method for producing the dispersion of the resin particles X described above.
In the step (3), for example, the resin particles Y are attached to the aggregated particles 1 in an aqueous medium by adding the dispersion of the resin particles Y to the dispersion containing the aggregated particles 1 at 30 ° C. or more and 80 ° C. or less. To obtain aggregated particles 2.

<< Amorphous polyester resin B >>
Examples of the amorphous polyester-based resin B include a polyester resin and a composite resin including a polyester resin segment and an addition-polymerized resin segment. Among these, a polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component is preferable.

When the amorphous polyester resin B is a polyester resin, the alcohol component and the carboxylic acid component are the same as those of the polyester resin segment in the composite resin A described above. In the case of a composite resin, examples of the amorphous polyester-based resin B are the same as those of the composite resin A described above.
Hereinafter, common examples will be omitted, and preferred embodiments of the polyester-based resin B will be described.
The alcohol component is preferably an aromatic diol, more preferably an alkylene oxide adduct of bisphenol A, and still more preferably an alkylene oxide adduct of bisphenol A represented by the formula (I). As the alkylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol A is preferable.
The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably at least 70 mol%, more preferably at least 90 mol%, still more preferably at least 95 mol%, and is at most 100 mol%, More preferably, it is 100 mol%.

  Examples of the method for producing the amorphous polyester-based resin B include the same examples as in the step A of the composite resin A described above.

(Physical properties of amorphous polyester resin B)
The softening point of the amorphous polyester resin B is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, further preferably 100 ° C. or higher, and preferably 140 ° C. from the viewpoint of further improving low-temperature fixability. Or less, more preferably 130 ° C. or less, further preferably 125 ° C. or less.

  The glass transition temperature of the amorphous polyester resin B is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and still more preferably 50 ° C. or higher. From the viewpoint of further improving low-temperature fixability, it is preferably 80 ° C. C. or lower, more preferably 75.degree. C. or lower, still more preferably 70.degree. C. or lower.

The acid value of the amorphous polyester-based resin B is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, from the viewpoint of further improving the charging performance maintenance rate, and It is preferably at most 40 mgKOH / g, more preferably at most 35 mgKOH / g, even more preferably at most 30 mgKOH / g.
The softening point, glass transition temperature, and acid value of the amorphous polyester-based resin B can be appropriately adjusted depending on the type of the raw material monomer and the amount used, as well as the reaction temperature, the reaction time, and the production conditions such as the cooling rate, Further, those values are obtained by the method described in the examples.
When two or more amorphous polyester-based resins B are used in combination, the softening point, glass transition temperature, and acid value obtained as a mixture thereof are preferably within the above ranges.

  The resin particles Y containing the amorphous polyester resin B are obtained, for example, by the same method as that for the resin particles X described above.

The content of the amorphous polyester resin B is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, based on the total amount of the resin components of the resin particles Y. Is 95% by mass or more, and 100% by mass or less, more preferably 100% by mass.
The mass ratio of the amorphous polyester resin B to the total amount of the composite resin A and the crystalline polyester resin C (the total amount of the amorphous polyester resin B / the composite resin A and the crystalline polyester resin C) is preferably Is 5/95 or more, more preferably 10/90 or more, still more preferably 15/85 or more, and preferably 30/70 or less, more preferably 25/75 or less, and even more preferably 20/80 or less. .

Aggregation may be stopped when the aggregated particles have grown to an appropriate particle size as toner particles.
Examples of the method of stopping the aggregation include a method of cooling the dispersion, a method of adding an aggregation stopper, a method of diluting the dispersion, and a method of changing the pH. From the viewpoint of surely preventing unnecessary aggregation, a method of adding an aggregation stopper to stop aggregation is preferable.

(Aggregation stop agent)
As the aggregation terminator, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include an alkyl benzene sulfonate, an alkyl sulfate, an alkyl ether sulfate, and a polyoxyalkylene alkyl ether sulfate. One or more aggregation stopping agents may be used. The aggregation terminator may be added in an aqueous solution.
The addition amount of the aggregation stopping agent is preferably 0 with respect to 100 parts by mass of the total amount of the composite resin A, the crystalline polyester resin C and the amorphous polyester resin B from the viewpoint of reliably preventing unnecessary aggregation. 0.1 part by mass or more, more preferably 1 part by mass or more, and preferably 30 parts by mass or less, and more preferably 15 parts by mass or less, from the viewpoint of reducing residual toner.

The volume median particle size (D ₅₀ ) of the aggregated particles 2 is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less. The volume median particle size (D ₅₀ ) of the aggregated particles is determined by a method described in Examples described later.

<Step (4)>
In the step (4), the aggregated particles 2 are fused at a temperature equal to or higher than 10 ° C. lower than the melting point of the crystalline polyester resin C in order to further improve the charging performance maintenance rate. It is considered that by performing the fusion at this temperature, the crosslinking of the resin by the oxazoline group-containing polymer is promoted, the movement of the crystalline polyester resin C is inhibited, and the charge performance retention rate can be further improved.
The fusion temperature is preferably at least 8 ° C. below the melting point of the crystalline polyester resin C, more preferably at least 4 ° C. below the melting point of the crystalline resin C, and preferably at least The temperature is 20 ° C. or lower than the melting point of the resin C, more preferably 10 ° C. or lower than the melting point of the crystalline polyester resin C, further preferably 5 ° C. or lower than the melting point of the crystalline polyester resin C.
Further, the fusing temperature is preferably 65 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 75 ° C. or higher, from the viewpoint of accelerating the crosslinking reaction by the oxazoline group and further improving the charging performance retention rate. , Preferably 100 ° C or lower.
In the fusion, the time maintained at the fusion temperature is preferably 1.5 hours or more, more preferably 2 hours or more, and still more preferably 2.5 hours or more, from the viewpoint of improving the charging performance retention rate. , Preferably 6 hours or less, more preferably 5 hours or less, and still more preferably 4 hours or less.
The fusion is usually performed in an aqueous medium.
It is preferable that the fusion be monitored by monitoring the circularity of the fused particles described below and be completed when the fusion degree becomes an appropriate range.

In step (4), an acidic substance may be added for fusion.
(Acidic substance)
Examples of the acidic substance include an inorganic acid and an organic acid.
Examples of the inorganic acid include nitric acid, sulfuric acid, hydrochloric acid, and phosphoric acid.
Examples of the organic acid include carboxylic acid compounds such as monocarboxylic acid, dicarboxylic acid, and tricarboxylic acid; sulfonic acid compounds such as methanesulfonic acid, benzenesulfonic acid, and toluenesulfonic acid; ascorbic acid, phenol, and cresol. Of these, carboxylic acid compounds are preferred.
Examples of the carboxylic acid compound include acetic acid, lactic acid, tartaric acid, propionic acid, benzoic acid, oxalic acid, terephthalic acid, fumaric acid, succinic acid, acrylic acid, and adipic acid.
Among these, inorganic acids are preferred, and sulfuric acid is more preferred.

The acidic substance is preferably added to the system as an aqueous solution of the acidic substance.
When the acidic substance is added as an aqueous solution, the concentration of the acidic substance in the aqueous solution of the acidic substance is preferably 0.01 mol / L or more, more preferably 0.03 mol / L or more, and still more preferably 0.05 mol / L or more. And preferably 1 mol / L or less, more preferably 0.8 mol / L or less, and still more preferably 0.5 mol / L or less.

  The method of adding the acidic substance may be any of a method of adding all at once, a method of adding the whole amount in two or more portions, and a method of adding continuously over a certain period of time. From the viewpoint of suppressing further agglomeration of the particles, either a method of adding the particles in a divided manner or a method of continuously adding the particles over a certain period of time is preferable. The temperature at which the acidic substance is added is preferably in the range of the above-mentioned fusing temperature.

The volume median particle size (D ₅₀ ) of the fused particles obtained by fusion is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 4 μm or more, and preferably 10 μm or less, more preferably It is 8 μm or less, more preferably 6 μm or less.
The circularity of the fused particles is preferably 0.945 or more, more preferably 0.950 or more, still more preferably 0.955 or more, and more preferably 0.95 or more, from the viewpoint of further improving the charging performance retention rate. It is 990 or less, more preferably 0.980 or less, and still more preferably 0.975 or less.
The circularity of the fused particles is determined according to the method described in Examples.

<Post-processing step>
A post-treatment step may be performed after the step (4), and toner particles are obtained by isolating the fused particles. Since the fused particles obtained in the step (4) exist in an aqueous medium, it is preferable to first perform solid-liquid separation. Examples of the solid-liquid separation include a suction filtration method, a pressure filtration method, and a centrifugal filtration method, and the suction filtration method is preferably used.
Washing is preferably performed after solid-liquid separation. At this time, since it is preferable to remove the added surfactant, it is preferable to wash with an aqueous medium at or below the cloud point of the surfactant. Washing is preferably performed a plurality of times.
Next, drying is preferably performed. Examples of the drying method include a vacuum low-temperature drying method, a vibration-type fluidized drying method, a spray drying method, a freeze drying method, and a flash drying method.

(Toner particles)
Although the toner particles can be used as they are, it is preferable to use those obtained by treating the surfaces of the toner particles as described below.
The volume median particle diameter (D ₅₀ ) of the toner particles is preferably 2 μm or more, more preferably 3 μm or more, and still more preferably 4 μm or more, from the viewpoint of obtaining a high-quality image and further improving the cleaning property of the toner. And preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less.
The volume median particle size (D ₅₀ ) of the toner particles can be measured by the method described in Examples.

  The content of the toner particles in the toner is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, further preferably 95% by mass or more, and 100% by mass or less. And preferably 99% by mass or less.

(External additive)
Although the toner particles can be used as they are, it is preferable to use a toner obtained by adding a fluidizing agent or the like to the surface of the toner particles as an external additive.
Examples of the external additive include inorganic material fine particles such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred.
When the surface treatment of the toner particles is performed using an external additive, the amount of the external additive is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 100 parts by mass of the toner particles. It is at least 3 parts by mass, and preferably at most 5 parts by mass, more preferably at most 4.5 parts by mass, even more preferably at most 4 parts by mass.

  The electrostatic image developing toner obtained by the present invention can be used as a one-component developer or as a two-component developer by mixing with a carrier.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like. In the following examples and the like, measurement and evaluation of each physical property were performed by the following methods.

[Measuring method]
(Resin acid value)
The acid value of the resin was measured according to JIS K0070: 1992. However, the measurement solvent was a mixed solvent of acetone and toluene [acetone: toluene = 1: 1 (volume ratio)].

(Resin softening point, crystallinity index, melting point and glass transition temperature)
(1) Softening point Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), while heating 1 g of a sample at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, and the diameter was increased. It was extruded from a 1 mm long, 1 mm long nozzle. The plunger descent of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.
(2) Crystallinity Index Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan, and the temperature was reduced to 10 ° C./min at 0 ° C. Until cooled. Next, the sample was allowed to stand still for 1 minute, and then heated to 180 ° C. at a heating rate of 10 ° C./min, and the calorie was measured. Of the endothermic peaks observed, the temperature of the peak having the largest peak area is defined as the maximum endothermic peak temperature (1), and (softening point (° C.)) / (Maximum endothermic peak temperature (1) (° C.)) The crystallinity index was determined.
(3) Melting point and glass transition temperature Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan, and heated to 200 ° C. From that temperature, it was cooled to 0 ° C. at a rate of 10 ° C./min. Thereafter, the temperature was raised at a rate of 10 ° C./min, and the calorific value was measured. Among the observed endothermic peaks, the peak temperature having the largest peak area was defined as the maximum endothermic peak temperature (2). For a crystalline resin, the peak temperature was taken as the melting point. When a level difference was observed in the case of an amorphous resin, the temperature at the intersection of the tangent line indicating the maximum slope of the curve of the level difference portion and the extension of the base line on the low temperature side of the level difference was defined as the glass transition temperature.

(Melting point of release agent)
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of a sample was weighed in an aluminum pan, heated to 200 ° C., and then cooled at a rate of 10 ° C. from 200 ° C. / Min at 0 ° C. Next, the sample was heated at a heating rate of 10 ° C./min, the amount of heat was measured, and the maximum endothermic peak temperature was defined as the melting point.

[Volume median particle diameter (D ₅₀ ) and CV value of resin particles, release agent particles, and colorant particles]
(1) Measuring device: Laser diffraction type particle size analyzer "LA-920" (manufactured by HORIBA, Ltd.)
(2) Measurement conditions: The sample dispersion liquid was taken in a measurement cell, distilled water was added, and the volume median particle diameter (D ₅₀ ) and the volume average particle diameter were measured at a temperature at which the absorbance was in an appropriate range. The CV value was calculated according to the following equation.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) × 100

(Resin particle dispersion, release agent particle dispersion, solid content concentration of colorant particle dispersion)
Using an infrared moisture meter "FD-230" (manufactured by Kett Science Laboratory Co., Ltd.), 5 g of the measurement sample was dried at 150 ° C. in a measurement mode of 96 (monitoring time: 2.5 minutes, fluctuation: 0.05%). And the water content (% by mass) of the dispersion was measured. The solid concentration was calculated according to the following equation.
Solid content concentration (% by mass) = 100-moisture (% by mass)

[Volume median particle size of aggregated particles (D ₅₀ )]
The volume median particle size (D ₅₀ ) of the aggregated particles was measured as follows.
-Measuring machine: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.)
・ Aperture diameter: 50 μm
-Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.)
・ Electrolyte: "Isothon (registered trademark) II" (manufactured by Beckman Coulter, Inc.)
Measurement conditions: after adding the sample dispersion to 100 mL of the electrolytic solution to adjust the particle size of 30,000 particles to a concentration that can be measured in 20 seconds, 30,000 particles were measured again, and the particle size was measured. The volume median particle size (D ₅₀ ) was determined from the distribution.

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

[Volume median particle diameter (D ₅₀ ) and CV value of toner particles]
The volume median particle size (D ₅₀ ) of the toner particles was measured as follows.
The same measurement device, aperture diameter, analysis software, and electrolyte solution as those used in the measurement of the volume median particle size (D ₅₀ ) of the aggregated particles described above were used.
-Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophil-Lipophile Balance) = 13.6) is dissolved in the electrolyte, and a dispersion having a concentration of 5% by mass. Got.
Dispersion conditions: 10 mg of a dried toner particle measurement sample was added to 5 mL of the above dispersion, dispersed for 1 minute with an ultrasonic disperser, and then 25 mL of electrolyte solution was added, and further, an ultrasonic disperser was used. The sample was dispersed for 1 minute to prepare a sample dispersion liquid.
Measurement conditions: The sample dispersion was added to 100 mL of the electrolytic solution to adjust the particle size of 30,000 particles to a concentration that can be measured in 20 seconds, and then 30,000 particles were measured. The volume median particle diameter (D ₅₀ ) and the volume average particle diameter were determined from the distribution.
The CV value (%) was calculated according to the following equation.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) × 100

[Evaluation method]
[Low-temperature fixability of toner]
Using a commercially available printer "Microline (registered trademark) 5400" (manufactured by Oki Data Co., Ltd.) on high quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), the toner adhesion amount on the paper is 1.49 to 1 A solid image of 0.51 mg / cm ² was output with a length of 50 mm without fixing, leaving a blank portion of 5 mm from the upper end of A4 paper. Next, the same printer in which the fixing device was modified so as to be variable in temperature was prepared, the temperature of the fixing device was set to 100 ° C., and the toner was fixed at a speed of 1.3 seconds per sheet in the A4 lengthwise direction to obtain a printed matter.
In the same manner, the temperature of the fixing device was increased by 5 ° C. at a time, and the toner was fixed to obtain a printed matter.
A piece of mending tape "Scotch (registered trademark) Mending Tape 810" (manufactured by Sumitomo 3M Limited, width 18 mm) cut to a length of 50 mm is lightly applied from the top margin to the solid image on the printed image. After that, a 500 g weight (contact area: 1963 mm ² ) was placed and pressed one reciprocation at a speed of 10 mm / s. Thereafter, the attached tape was peeled from the lower end side at a peeling angle of 180 ° and a speed of 10 mm / s to obtain a printed material after the tape was peeled off. 30 sheets of high-quality paper “Excellent White Paper A4 Size” (manufactured by Oki Data Co., Ltd.) are laid under the printed matter before and after the tape is attached, and the reflection image density of the fixed image portion of each printed matter before and after the tape is attached is measured. It was measured using a colorimeter "SpectroEye" (manufactured by GretagMacbeth Co., Ltd., light irradiation conditions; standard light source D50, observation field of 2 °, density standard DINNB, absolute white standard), and the fixing rate was calculated from each reflected image density according to the following formula. Was calculated.
Fixing rate (%) = (reflective image density after tape peeling / reflective image density before tape sticking) × 100
The lowest temperature at which the fixing rate became 90% or more was defined as the lowest fixing temperature. The lower the minimum fixing temperature in this test, the better the low-temperature fixability.

[Maintenance rate of toner charging performance]
At 25 ° C., a solid image was printed on excellent white paper (80 g / m ² paper made by Oki Data Co., Ltd.) using a commercially available printer “Microline (registered trademark) 5400” (made by Oki Data Co., Ltd.), and the half of A4 paper was printed. When the transfer was completed, the machine was stopped, a 1 cm × 2 cm jig was attached to each of the portions 3 cm from both ends on the developing roller, and the charge amount was measured using a Q / m meter “210HS” (manufactured by Trek). The value of this charge amount is defined as the initial charge amount.
Next, the toner was allowed to stand in a dryer at a temperature of 55 ° C. for 8 hours, then taken out, and allowed to cool at 25 ° C. for 12 hours. The amount of charge on the developing roller after printing by the same method using the cooled toner was measured. The value of the charge amount was defined as the charge amount after storage, and the charge retention was determined by the following equation. The larger the value, the better the charge retention.
Charging ability maintenance rate (%) = Charge amount after storage / Initial charge amount × 100

[Production of resin]
Production Example A1 (Production of amorphous resin A-1)
The inside of a 10 L four-necked flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple was purged with nitrogen, and 4200 g of propylene oxide (2.2) adduct of bisphenol A, 1355 g of terephthalic acid, 31 g of tin (II) (2-ethylhexanoate) and 3 g of gallic acid (3,4,5-trihydroxybenzoic acid) were added, and the mixture was heated to 235 ° C. with stirring under a nitrogen atmosphere, and heated at 235 ° C. After maintaining for 5 hours, the pressure in the flask was lowered and maintained at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, the mixture was cooled to 160 ° C., and a mixture of 1819 g of styrene, 455 g of stearyl methacrylate, 138 g of acrylic acid, and 227 g of dibutyl peroxide was added dropwise over 1 hour while maintaining the temperature at 160 ° C. Thereafter, the temperature was maintained at 160 ° C. for 30 minutes, then the temperature was raised to 200 ° C., the pressure in the flask was further reduced, and the temperature was maintained at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, it cooled to 190 degreeC, 223 g of fumaric acid, 230 g of trimellitic anhydride, and 2.5 g of 4-tert-butylcatechol were added, and it heated up to 210 degreeC at 10 degreeC / hr. Thereafter, the reaction was performed at 4 kPa to a desired softening point to obtain an amorphous resin A-1. Various physical properties of the resin were measured and are shown in Table 1.

Production Example A2 (Production of amorphous resin A-2)
Amorphous resin A-2 was obtained in the same manner as in Production Example A1, except that the amounts of various monomers were changed as shown in Table 1. Various physical properties of the resin were measured and are shown in Table 1.

Production Example B1 (Production of amorphous resin B-1)
The inside 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 ethylene oxide (2.2) adduct of bisphenol A, 1780 g of terephthalic acid, 40 g of tin (II) (2-ethylhexanoate) and 4 g of gallic acid were added, and the mixture was heated to 235 ° C. and stirred at 235 ° C. for 8 hours under a nitrogen atmosphere, and then the pressure in the flask was lowered. , 8 kPa for 1 hour. Then, after returning to atmospheric pressure, it cooled to 180 degreeC, 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, and it was 10 degreeC to 220 degreeC. / Hr, the pressure in the flask was lowered, and the reaction was performed at 10 kPa to a desired softening point to obtain an amorphous resin B-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.

Production Example D1 (Production of amorphous resin D-1)
The inside of a 10 L four-necked flask equipped with a nitrogen introducing tube, a dehydrating tube, a stirrer, and a thermocouple was purged with nitrogen, 4313 g of propylene oxide (2.2) adduct of bisphenol A, 818 g of terephthalic acid, and succinic acid were added. After adding 727 g of acid, 30 g of di (2-ethylhexanoic acid) tin (II) and 3 g of gallic acid, the mixture was heated to 235 ° C. while stirring under a nitrogen atmosphere, and kept at 235 ° C. for 5 hours. , And kept at 8 kPa for 1 hour. Then, after returning to the atmospheric pressure, the mixture was cooled to 160 ° C., and a mixture of 2755 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 while maintaining the temperature at 160 ° C. Then, after maintaining at 160 ° C. for 30 minutes, the temperature was raised to 200 ° C., the pressure in the flask was further reduced, and the reaction was performed at 8 kPa to a desired softening point to obtain an amorphous resin D-1. Various physical properties of the resin were measured and are shown in Table 1.

Production Example C1 (Production of crystalline polyester resin C-1)
The inside of a 10 L four-necked flask equipped with a nitrogen introducing tube, a dehydrating tube, a stirrer, and a thermocouple was purged with nitrogen, and 3,416 g of 1,10-decanediol and 4084 g of sebacic acid were charged. While stirring, the temperature was raised to 135 ° C., maintained at 135 ° C. for 3 hours, and then raised from 135 ° C. to 200 ° C. over 10 hours. Thereafter, 23 g of tin (II) di (2-ethylhexanoate) was added, and the mixture was further maintained at 200 ° C. for 1 hour. Then, the pressure in the flask was lowered, and the flask was maintained at 8.3 kPa for 1 hour. C-1 was obtained. Various physical properties of the resin were measured and are shown in Table 2.

[Production of resin particle dispersion]
Production Example X1 (Production of resin particle dispersion liquid X-1)
A three-liter container equipped with a stirrer “Three One Motor BL300” (manufactured by Shinto Kagaku Co., Ltd.), a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, 210 g of amorphous resin A-1 and crystals 90 g of the water-soluble polyester resin C-1 and 300 g of methyl ethyl ketone were added, and the resin was dissolved at 73 ° C. for 2 hours. To the resulting solution, a 5% by mass aqueous solution of sodium hydroxide was added so as to have a degree of neutralization of 55 mol% with respect to the acid value of the resin, and the mixture was stirred for 60 minutes.
Next, 600 g of deionized water was added over 60 minutes while stirring at 200 r / min (peripheral speed 63 m / min) while maintaining the temperature at 73 ° C., and the mixture was subjected to phase inversion emulsification. While maintaining the temperature at 73 ° C., 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 then adjusted by adding deionized water so that the solid content concentration became 30% by mass. -1 was obtained. Table 3 shows the volume median particle size (D ₅₀ ) and CV value of the obtained resin particles.

Production Example X2 (Production of resin particle dispersion liquid X-2)
A resin particle dispersion liquid X-2 was obtained in the same manner as in Production Example X1, except that the amorphous resin and the crystalline polyester resin used were combined as shown in Table 3. Table 3 shows the volume median particle size (D ₅₀ ) and CV value of the obtained resin particles.

Production Examples X3, Y1, Z1 (Production of Resin Particle Dispersions X-3, Y-1, Z-1)
Production except that the amorphous resin and the crystalline polyester resin used were combined as shown in Table 3, and the resin was neutralized with an aqueous solution of sodium hydroxide so that the degree of neutralization was 60 mol% with respect to the acid value of the resin. Resin particle dispersions X-3, Y-1, and Z-1 were obtained in the same manner as in Example X1. Table 3 shows the volume median particle size (D ₅₀ ) and CV value of the obtained resin particles.

[Production of crosslinked resin particle dispersion]
Production Example XC1 (Production of Crosslinked Resin Particle Dispersion XC-1)
A three-liter container equipped with a stirrer “Three One Motor BL300” (manufactured by Shinto Kagaku Co., Ltd.), a reflux condenser, and a thermometer, 500 g of the resin particle dispersion X-1 and an oxazoline group-containing polymer aqueous solution “Epocross” WS-700 "(manufactured by Nippon Shokubai Co., Ltd., solid content 25% by mass, oxazoline group content 4.5 mmol / g, oxazoline value 220 g / eq (based on solid content), number average molecular weight Mn2000, weight average molecular weight Mw 4000) 4. 8 g was added, and the mixture was stirred and mixed at 25 ° C. Thereafter, the temperature was raised to 95 ° C over 30 minutes while stirring, and the temperature was maintained at 95 ° C for 1 hour. After cooling to 30 ° C. with stirring, the solid content was adjusted by adding deionized water to 30% by mass, and then filtered through a 150-mesh wire net to obtain a crosslinked resin particle dispersion XC-1.

Production Examples XC2 to XC7, XC82 to XC83 (Production of Crosslinked Resin Particle Dispersions XC-2 to XC-7, XC-82 to XC-83)
In Production Example XC1, the resin particle dispersion, the amount of the oxazoline group-containing polymer added, and the heat treatment conditions were changed as shown in Table 4, and the crosslinked resin particle dispersions XC-2 to XC-7, XC-82 to XC-83 was obtained.

Production Example XC81 (Production of Crosslinked Resin Particle Dispersion XC-81)
In Preparation Example XC1, a crosslinked resin particle dispersion XC-81 was obtained in the same manner except that the mixture was stirred and mixed at 25 ° C., and then maintained at 25 ° C. for 1 hour without raising the temperature to 95 ° C.

[Production of release agent particle dispersion]
Production Example W1 (Production of release agent particle dispersion W-1)
To a beaker having an inner volume of 1 L, 120 g of deionized water, 53 g of resin particle dispersion Z-1 and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point: 75C) are added, and the mixture is heated to 90 to 95C. The mixture was melted while maintaining the temperature and stirred to obtain a molten mixture. While maintaining the temperature at 90 to 95 ° C., a dispersion treatment was performed for 20 minutes using an ultrasonic homogenizer “US-600T” (manufactured by Nippon Seiki Seisaku-sho, Ltd.), followed by cooling to room temperature (20 ° C.). Deionized water was added to the obtained dispersion to adjust the solid content concentration to 20% by mass to obtain a release agent particle dispersion W-1. The volume median particle size (D ₅₀ ) was 0.45 μm, and the CV value was 26%.

[Production of colorant particle dispersion]
Production Example P1 (Production of Colorant Particle Dispersion P-1)
In a beaker having an inner volume of 1 L, 136.0 g of a copper phthalocyanine pigment “ECB-301” (manufactured by Dainichi Seika Kogyo Co., Ltd.) and an anionic surfactant “Neoperex (registered trademark) G-15” (manufactured by Kao Corporation, 181.3 g of a 15% by mass aqueous sodium dodecylbenzenesulfonate solution and 340 g of deionized water are mixed, and dispersed using a homogenizer at room temperature (20 ° C.) for 3 hours, so that the solid content concentration becomes 24% by mass. Colorant particle dispersion P-1 was obtained by adding deionized water. The volume median particle size (D ₅₀ ) of the colorant particles in the dispersion was 0.12 μm.

[Manufacture of toner]
Example 1 (Production of Toner 1)
300 g of the crosslinked resin particle dispersion XC-1, 50.6 g of the release agent particle dispersion W-1 and 50.6 g of the colorant particles were dispersed in a 2 L four-necked flask equipped with a dehydrating tube, a stirrer, and a thermocouple. 33.8 g of liquid P-1, 9 g of a 10% by mass aqueous solution of a nonionic surfactant "Emulgen (registered trademark) 150" (manufactured by Kao Corporation, polyoxyethylene (average addition mole number: 50) lauryl ether), anion 6 g of a water-soluble surfactant “Neodelex G15” (manufactured by Kao Corporation, sodium dodecylbenzenesulfonate, effective concentration 15%) and 150.0 g of deionized water were mixed at 25 ° C. Next, while stirring the mixture, 22.4 g of a 4.8 mass% aqueous potassium hydroxide solution was added to an aqueous solution in which 31.0 g of ammonium sulfate was dissolved in 449 g of deionized water to adjust the pH to 8.4. After dropping at 15 ° C. over 15 minutes, the temperature was raised to 62 ° C. over 2 hours, and kept at 62 ° C. until the volume median particle size (D ₅₀ ) of the aggregated particles became 5.1 μm. Was obtained.
While cooling the dispersion of the aggregated particles 1 to 55 ° C. and keeping the dispersion at 55 ° C., a mixed liquid of 60.0 g of the resin particle dispersion Y-1 and 18.3 g of deionized water was added over 120 minutes, and the aggregated particles were added. A dispersion liquid of aggregated particles 2 in which resin particles were aggregated in 1 was obtained.
17.4 g of anionic surfactant "Emal (registered trademark) E-27C" (manufactured by Kao Corporation, sodium polyoxyethylene lauryl ether sulfate, effective concentration 27% by mass) was added to the dispersion of the aggregated particles 2, and deionized. An aqueous solution obtained by mixing 590.1 g of water was added. Thereafter, the temperature was raised to 75 ° C. over 1 hour. After reaching 75 ° C., 98.0 g of a 0.1 mol / L aqueous sulfuric acid solution was added. By maintaining the temperature at 75 ° C. for 3 hours, a fused particle dispersion in which the aggregated particles 2 were fused was obtained.
The obtained dispersion of the fused particles was cooled to 30 ° C., filtered by suction to separate a solid content, washed with deionized water at 25 ° C., and vacuum-dried at 35 ° C. for 48 hours to obtain a toner. Particles were obtained. 100 parts by mass of the toner particles, 2.5 parts by mass of hydrophobic silica “RY50” (manufactured by Nippon Aerosil Co., Ltd., number average particle size: 0.04 μm), and hydrophobic silica “Cabosil (registered trademark) TS720” (Cabot Japan) 1.0 part by mass (manufactured by Co., Ltd., number average particle size: 0.012 μm) was placed in a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain Toner 1. The obtained toner was evaluated, and the results are shown in Table 5.

Examples 2 to 9, Comparative Examples 1 to 5 (Toners 2 to 9, 81 to 85)
Toners 2 to 9, 81 to 85 were obtained in the same manner as in Example 1 except that the dispersion liquid and the fusion step conditions (time and temperature) were changed as shown in Table 5. The obtained toner was evaluated, and the results are shown in Table 5.

From the results of Examples and Comparative Examples, it can be seen that the present invention can provide a toner having excellent low-temperature fixability and an excellent charge performance maintenance ratio.
According to Comparative Example 1, in the toner containing no crystalline polyester resin, there is no particular problem regarding the charging performance maintenance ratio, but satisfactory low-temperature fixability cannot be obtained. On the other hand, as shown in Comparative Example 2, it was clarified that the toner containing the crystalline polyester resin improved the low-temperature fixability, but decreased the charging performance maintenance ratio. Furthermore, as shown in Comparative Example 3, even when a resin particle dispersion in which resin particles X and an oxazoline group-containing polymer are mixed is used, if heating is not performed under a predetermined range of temperature conditions, The charging performance maintenance rate is not remarkable. On the other hand, as shown in Example 1, it can be seen from the production method of the present invention that the obtained toner is excellent in low-temperature fixability and charging performance maintenance rate.

Claims (7)

Mixing resin particles X containing the composite resin A and the crystalline polyester resin C in the same or different resin particles, and an oxazoline group-containing polymer, and heating the mixture at a temperature equal to or higher than the melting point of the crystalline polyester resin C;
A step of aggregating the resin particles X in an aqueous medium to obtain aggregated particles, and
Including a step of fusing the obtained aggregated particles at a temperature of 10 ° C. or lower than the melting point of the crystalline polyester resin C,
The composite resin A includes a polyester resin segment which is a polycondensate of an alcohol component and a carboxylic acid component, and a vinyl resin segment which is an addition polymer of a raw material monomer containing a styrene compound.
The amount of the oxazoline group-containing polymer to be added is 0.1 as the number of moles (Oxz equivalent) of the oxazoline group of the oxazoline group-containing polymer relative to the number of moles of the acid groups in the composite resin A and the crystalline polyester resin C. A method for producing a toner for developing an electrostatic image, which is at least 02 equivalents.   In the step of obtaining the aggregated particles, after the resin particles X are aggregated in an aqueous medium, the resin particles Y containing the amorphous polyester-based resin B are further attached to the aggregated particles to obtain aggregated particles. 2. The method for producing an electrostatic image developing toner according to item 1.   3. The electrostatic image developing device according to claim 1, wherein in the fusing step, the temperature is maintained at a temperature of 10 ° C. or lower than the melting point of the crystalline polyester resin C for 1.5 hours to 6 hours. 4. Manufacturing method of toner.   The mass ratio [crystalline polyester resin C / composite resin A] of the crystalline polyester resin C and the composite resin A in the resin particles X is 15/85 or more and 60/40 or less. The method for producing a toner for developing electrostatic images according to any one of the above.   The amount of the oxazoline group-containing polymer to be added is 0.1 as the number of moles (Oxz equivalent) of the oxazoline group of the oxazoline group-containing polymer relative to the number of moles of the acid groups in the composite resin A and the crystalline polyester resin C. The method for producing a toner for developing electrostatic images according to any one of claims 1 to 4, wherein the amount is from 02 equivalents to 0.55 equivalents.   The addition amount of the oxazoline group-containing polymer is 0.1 part by mass or more and 2.5 parts by mass or less based on 100 parts by mass of the total amount of the composite resin A and the crystalline polyester resin C. 6. The method for producing a toner for developing an electrostatic image according to any one of items 1 to 5.   The static polyester according to any one of claims 1 to 6, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing an α, ω-aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid. A method for producing a toner for developing a charge image.