JP2015125406A - Manufacturing method of electrophotographic toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an electrophotographic toner that has an excellent heat-resistant storage property and holds a high charge amount even after continuous printing.SOLUTION: A manufacturing method of an electrophotographic toner includes: a step (1) of emulsifying a resin containing a polyester (a) having an acid radical to obtain resin particles (A); a step (2) of aggregating the resin particles (A) in an aqueous medium to obtain aggregated particles (I); a step (3) of aggregating resin particles (C) having an acid radical and containing an amorphous polyester (c) having a Tg of 55°C or more on the surface of the aggregated particles (I) to obtain aggregated particles (II); and a step (4) of holding the particles (II) within a range of a Tg of -5°C to a Tg of +10°C of the polyester (c) to obtain core-shell particles, where the method further including a step of adding at least two oxazoline group-containing polymer compounds within such a range that the mol number of the oxazoline group in the polymer compound to the mol number of the acid radical of the polyester (a) becomes an equivalent of 0.02 to 0.45 before the step (3), and the difference in an SP value between the polyester (a) and the polyester (c) is 0.6 or more and less than 1.8.

Description

  The present invention relates to a method for producing an electrophotographic toner.

In the field of electrophotographic toners, needs such as high-speed printing and high image quality are desired with the development of electrophotographic systems. In recent years, as a toner having a small particle size and a uniform particle size distribution, a so-called chemical toner obtained by a chemical method such as a suspension polymerization method or an emulsion aggregation method has been proposed instead of the conventional melt-kneading pulverization method.
For example, Patent Document 1 and Patent Document 2 disclose a technique for producing a core-shell toner using polyester. By adding an agent capable of reacting with polyester, storage stability is good and the non-offset region is expanded. A technique relating to a chemical toner or a toner having excellent low-temperature fixability is disclosed. In addition, chemical toners may be functionally separated by a core-shell structure using different types of polymers. For example, in Patent Document 3, in order to obtain a toner excellent in fixing releasability, an encapsulated toner using a different polymer for a resin constituting a core and a resin constituting a shell can react with polyester. Techniques for adding ingredients are disclosed.

JP 2009-58927 A JP 2010-78828 A JP 2013-160807 A

However, none of the techniques described in Patent Documents 1 to 3 are sufficiently compatible with high-speed printing and high image quality that have been required in recent years. When a large amount of printing was continuously performed, a high charge amount could not be maintained, and a problem remained. In response to the need for higher speeds, in general, a resin having a low glass transition temperature (Tg) is used as the resin constituting the core, so that low-temperature fixing can be achieved and high-speed printing can be achieved. In order to ensure storage stability and chargeability, it is necessary to use a resin that is easily charged with a high Tg as a resin constituting the shell. In the core-shell toners disclosed in Patent Documents 2 and 3, different resins are used for the core and the shell, but due to heat during toner production, compatibility occurs between the core-shell, resulting in a decrease in Tg on the toner surface. Preservability may deteriorate. On the other hand, the toner of the core-shell structure has a problem that the core-shell structure is broken due to a share in the image forming apparatus (an external load is applied to the toner), causing a decrease in chargeability.
An object of the present invention is to provide a method for producing an electrophotographic toner that has excellent heat-resistant storage stability and retains a high charge amount even after continuous printing.

The present invention relates to the following method for producing an electrophotographic toner.
Step (1): Step of emulsifying a resin containing at least a polyester (a) having an acid group to obtain resin particles (A),
Step (2): a step of aggregating the resin particles (A) in an aqueous medium to obtain agglomerated particles (I);
Step (3): The resin particles (C) containing at least an acid group and containing an amorphous polyester (c) having a glass transition temperature of 55 ° C. or higher are aggregated on the surface of the aggregated particles (I). Obtaining aggregated particles (II), and
Step (4): The aggregated particles (II) are fused within the range of the glass transition temperature of the amorphous polyester (c) from −5 ° C. to the glass transition temperature + 10 ° C. And obtaining a core-shell particle, a method for producing an electrophotographic core-shell toner comprising:
Before the step (3), the polymer compound containing at least two oxazoline groups has a molar number of oxazoline groups of the polymer compound of 0.02 equivalents or more relative to the number of acid groups in the polyester (a). Having a step of adding in a range of 0.45 equivalent or less,
A method for producing an electrophotographic toner, wherein a difference in solubility parameter (SP value) between the polyester (a) and the amorphous polyester (c) by a Fedors method is 0.6 or more and less than 1.8.

  According to the present invention, it is possible to produce an electrophotographic toner that has excellent heat resistant storage stability and retains a high charge amount even after continuous printing.

<Method for producing electrophotographic toner>
The method for producing the electrophotographic toner of the present invention includes:
Step (1): Step of emulsifying a resin containing at least a polyester (a) having an acid group to obtain resin particles (A),
Step (2): a step of aggregating the resin particles (A) in an aqueous medium to obtain agglomerated particles (I);
Step (3): The resin particles (C) containing at least an acid group and containing an amorphous polyester (c) having a glass transition temperature of 55 ° C. or higher are aggregated on the surface of the aggregated particles (I). Obtaining aggregated particles (II), and
Step (4): The aggregated particles (II) are fused within the range of the glass transition temperature of the amorphous polyester (c) from −5 ° C. to the glass transition temperature + 10 ° C. And obtaining a core-shell particle, a method for producing an electrophotographic core-shell toner comprising:
Before the step (3), the polymer compound containing at least two oxazoline groups has a molar number of oxazoline groups of the polymer compound of 0.02 equivalents or more relative to the number of acid groups in the polyester (a). Having a step of adding in a range of 0.45 equivalent or less,
The difference in solubility parameter (SP value) by the Fedors method between the polyester (a) and the amorphous polyester (c) is 0.6 or more and less than 1.8.
The solubility parameter of the polyester (a) by the Fedors method is sometimes referred to as “SPa”, and the solubility parameter of the amorphous polyester (c) by the Fedors method is sometimes referred to as “SPc”. Furthermore, the difference (| SPa−SPc |) in solubility parameter by the Fedors method between polyester (a) and amorphous polyester (c) may be referred to as “ΔSP”.

The reason why an electrophotographic toner that has excellent heat-resistant storage stability and retains a high charge amount even after continuous printing can be manufactured by using the above-described method for producing an electrophotographic toner is not clear. Presumably due to action.
In the method for producing an electrophotographic toner of the present invention, a chemical toner having a core-shell structure including a resin constituting a core and a resin constituting a shell is produced using an aqueous medium. Hereinafter, the resin constituting the core may be referred to as “core resin”, and the resin constituting the shell may be referred to as “shell resin”.
Conventionally, when polyesters having different properties are used as the core resin and the shell resin, the core resin and the shell resin may be separated after the toner is manufactured. In addition, in order to suppress separation of the core resin from the shell resin, if the compatibility is increased, the core resin and the shell resin are integrated to achieve both heat-resistant storage and high charge retention even after continuous printing. Was insufficient. Therefore, in order for the toner to exhibit the functions of the core and the shell, and to achieve both heat-resistant storage stability and high charge retention even after continuous printing, the core resin and the shell resin are incompatible, and the core resin and the shell resin Is not required to be separated.

On the other hand, in the present invention, it is considered that the core resin and the shell resin can be phase-separated by controlling the difference (ΔSP) between the SP value of the core resin and the SP value of the shell resin within a certain range. . Further, after the preparation of the resin particles (A) containing the core resin and before obtaining the aggregated particles (II) containing the shell resin, a polymer compound containing at least two oxazoline groups (hereinafter referred to as “the present invention”). It is considered that the acid group of the polyester and the oxazoline group are strongly chemically bonded by introducing an “oxazoline polymer compound”. By chemically bonding the phase-separated resins, the core-shell structure can be maintained stably, and by physically bonding with the oxazoline polymer compound of the present invention, a physically strong core-shell toner can be obtained. It is considered possible.
At this time, after introducing the polymer compound containing the oxazoline group, the core resin is fused by fusing the shell resin in the range of the glass transition temperature −5 ° C. to the glass transition temperature + 10 ° C. of the amorphous polyester (c). In addition, since the reaction of the polyester between the oxazoline and the core shell can be promoted while appropriately suppressing the molecular motion of the polyester contained in the shell resin, it is considered that the chemical bond between the phase separated resins is facilitated.
Therefore, it is considered that the core resin and the shell resin can be bonded to each other while maintaining the phase separation between the core resin and the shell resin, and the toner maintains the core-shell structure. In addition, the core / shell structure of the core resin and the shell resin by the oxazoline compound is a chemical bond and is firmly fixed. Therefore, even in an environment where the toner is repeatedly printed and exposed to an external load, the core / shell structure of the toner It is thought to maintain.
As a result, the toner maintains a core-shell structure in which the core resin is protected by a shell resin that is excellent in heat-resistant storage stability. Therefore, the toner has excellent heat-resistant storage stability and retains a high charge even after continuous printing (for example, after printing 500 sheets) I think it can be done.
Hereinafter, each component and process used in the present invention will be described.

[Step (1)]
Step (1) emulsifies a resin containing polyester (a) having at least an acid group to obtain resin particles (A).
What is necessary is just to perform emulsification of resin containing polyester (a) by a well-known method.
For example, a step of mixing a resin containing polyester (a) with a basic aqueous solution to obtain a resin neutralized product, adding an aqueous medium to the obtained resin neutralized product, and emulsifying the resin neutralized product In the step of obtaining the resin particle dispersion, the resin containing the polyester (a) can be emulsified to obtain the resin particle (A) dispersion.
The resin particles (A) may contain, for example, a colorant, a surfactant and the like in addition to the resin containing the polyester (a).

(Polyester (a))
The polyester (a) has at least an acid group.
When the polyester (a) has an acid group, emulsification of the resin containing the polyester (a) is facilitated, and the dispersion stability of the resin particles (A) is increased. Examples of the acid group include a carboxy group, a sulfonic acid group, a phosphonic acid group, and a sulfinic acid group, and a carboxy group is preferable from the viewpoint of achieving both the dispersion stability of the resin and the heat-resistant storage stability of the obtained toner.

Moreover, the difference of the solubility parameter (SP value) by the Fedors method with respect to polyester (a) and amorphous polyester (c) mentioned later is 0.6 or more and less than 1.8.
In the present specification, the “solubility parameter value (SP value)” is a value δ determined based on the following equation by the method of Fedors [Robert F. Fedors, Polymer Engineering and Science, 14, 147-154 (1974)]. It is.
Fedors equation: δ = (ΣΔei / ΣΔvi) ^1/2
[Unit: (cal / cm ³ ) ^1/2 ]
[Where Δei is the evaporation energy (cal / mol) of atoms and atomic groups, and Δvi is the molar volume (cm ³ / mol). ]
The polyester (a) is contained by setting the difference (ΔSP) between the solubility parameter SPa of the polyester (a) by the Fedors method and the solubility parameter SPc of the amorphous polyester (c) by the Fedors method to 0.6 or more. Compatibility between the resin and the resin containing the amorphous polyester (c) can be suppressed, and the phase separation state can be maintained. Further, the Tg of the resin containing the polyester (a) and the Tg of the resin containing the amorphous polyester (c) are easily separated. The resin containing the polyester (a) functions as a core resin of the core-shell toner, and the resin containing the amorphous polyester (c) can function as a shell resin. Therefore, the functional separation by the core-shell structure can be sufficiently achieved, and the heat resistant storage stability of the toner can be expressed.
ΔSP is less than 1.8, so that there is some room for mutual diffusion while maintaining the phase separation state between the resin containing polyester (a) and the resin containing amorphous polyester (c). Therefore, damage to the core-shell structure such as peeling of the shell resin from the core resin can be suppressed.

ΔSP is preferably 0.7 or more, more preferably 0.8 or more, still more preferably 0.9 or more, from the viewpoint of maintaining the core-shell structure of the toner while maintaining phase separation between the core resin and the shell resin. More preferably, it is 1.0 or more. From the same viewpoint, the upper limit of ΔSP is preferably 1.5 or less, more preferably 1.4 or less, and still more preferably 1.3 or less.
Although it differs depending on the combination of the polyester (a) and the amorphous polyester (c), SPa is preferably 8.0 or more, more preferably 9. from the viewpoint of obtaining good storage stability by suppressing compatibility with the shell. It is 0 or more, more preferably 10.0 or more. From the same viewpoint, the upper limit of SPa is preferably 12.0 or less, more preferably 11.5 or less, and still more preferably 11.0 or less.

The raw material monomer of the polyester (a) having an acid group is not particularly limited, and any alcohol component and any carboxylic acid component such as carboxylic acid, carboxylic acid anhydride, or carboxylic acid ester can be used.
Preferable specific examples of the carboxylic acid component include aromatic dicarboxylic acid, aliphatic dicarboxylic acid, and polyvalent carboxylic acid, and anhydrides of these acids and alkyl esters (1 to 3 carbon atoms) of those acids. Etc.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like.
Examples of the aliphatic dicarboxylic acid include fumaric acid, maleic acid, adipic acid, succinic acid, sebacic acid, azelaic acid, an alkyl group having 1 to 20 carbon atoms, or a succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms. Etc.
Specific examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, octenyl succinic acid, and the like. Among them, alkenyl succinic acid is preferable from the viewpoint of maintaining the charge amount of the toner and imparting low-temperature fixability to the toner. The number of carbon atoms of the alkenyl group of the alkenyl succinic acid is preferably 2 or more, more preferably 4 or more, still more preferably 8 or more, and preferably 20 or less, more preferably 18 or less, still more preferably 16 or less. . As alkenyl succinic acid, dodecenyl succinic acid and its acid anhydride are preferable.
Examples of the polyvalent carboxylic acid include trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid.

These carboxylic acid components may be used individually by 1 type, and may be used in combination of 2 or more type.
Among these, from the viewpoint of maintaining a high toner charge amount and a low-temperature fixability toner, the aliphatic dicarboxylic acid and aromatic dicarboxylic acid and their acid anhydrides, more preferably fumaric acid and alkenyl succinic acid are preferred. It is at least one of acid, phthalic acid, trimellitic acid and isophthalic acid and their acid anhydrides.
From the viewpoint of maintaining a higher charge amount of the toner, the carboxylic acid component is more preferably at least one of alkenyl succinic acid, trimellitic acid, isophthalic acid, and acid anhydrides thereof. Further, from the viewpoint of further improving the low-temperature fixability of the toner, the carboxylic acid component is more preferably at least one of fumaric acid, alkenyl succinic acid and isophthalic acid, and acid anhydrides thereof.
Further, the ratio of the aromatic dicarboxylic acid and the acid anhydride in the total of 100 mol% of the aliphatic dicarboxylic acid and the acid anhydride and the aromatic dicarboxylic acid and the acid anhydride maintains a high charge amount of the toner. From the viewpoint of imparting low-temperature fixability to the toner, it is preferably less than 60 mol%, more preferably 57 mol% or less, still more preferably 55 mol% or less, and preferably 40 mol% or more.

  Preferable specific examples of the alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane (sometimes referred to as “BPA-PO”), polyoxyethylene (2.2 ) -2,2-bis (4-hydroxyphenyl) propane [may be referred to as “BPA-EO”], etc. Bisphenol A alkylene (2 to 3 carbon atoms) oxide (average added mole number 1 to 16) ) Aromatic diols such as adducts; alicyclic diols such as hydrogenated bisphenol A; and ethylene glycol, 1,2-propanediol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, 2 , 3-butanediol, 1,6-hexanediol or their alkylene (2 to 4 carbon atoms) oxide (standard Addition mole number 1 to 16) Aliphatic diols such as adducts; addition of glycerin, pentaerythritol, trimethylolpropane, sorbitol or their alkylene (2 to 4 carbon atoms) oxide (average addition mole number 1 to 16) Aliphatic polyhydric alcohols such as products. These alcohols may be used individually by 1 type, and may be used in combination of 2 or more type.

From the viewpoint of maintaining the charge amount of the toner and fixing at low temperature, the alcohol component includes ethylene glycol, 1,2-propanediol, neopentyl glycol, 1,4-butanediol, 1,3-butanediol, and 2,3-butane. Aliphatic diols having 2 to 4 carbon atoms such as diol, and alkylene (2 to 3 carbon atoms) oxide (average added mole number 1 to 16) adducts of bisphenol A such as BPA-PO and BPA-EO Aromatic diols such as are preferred.
From the viewpoint of maintaining the charge amount of the toner, the alcohol component is more preferably BPA-PO and BPA-EO. From the same viewpoint, the content of BPA-PO and BPA-EO is preferably 70 mol in the total alcohol components. % Or more, more preferably 80 mol% or more, still more preferably substantially 100 mol%, still more preferably 100 mol%.
The alcohol component is more preferably 1,2-propanediol from the viewpoint of low-temperature fixability of the toner. From the same viewpoint, the content of 1,2-propanediol is preferably 70 mol% or more in the total alcohol components. More preferably, it is 80 mol% or more, More preferably, it is substantially 100 mol%, More preferably, it is 100 mol%.

The polyester (a) is a polyester obtained by condensation polymerization of a carboxylic acid component containing at least one of alkenyl succinic acid and its acid anhydride and an alcohol component from the viewpoint of maintaining the charge amount of the toner and fixing at low temperature. Is preferred.

The equivalent ratio (COOH group / OH group) of the carboxylic acid component and the alcohol component in the polyester (a) is preferably from the viewpoint of facilitating emulsification of the resin containing the polyester (a) and enhancing the dispersion stability. It is 80 or more, more preferably 0.85 or more, preferably 1.10 or less, more preferably 1.05 or less.

  The polycondensation reaction between the alcohol component and the carboxylic acid component is carried out in an inert gas atmosphere, if necessary, in the presence of an esterification catalyst, an esterification cocatalyst, a polymerization inhibitor, etc., at about 180 ° C. or more and about 250 ° C. Can be produced by condensation polymerization at a temperature of Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and di (2-ethylhexanoic acid) tin, and titanium compounds such as titanium diisopropylate bistriethanolamate. Examples of the esterification cocatalyst include gallic acid. Etc. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1. parts by mass or more with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. 0 parts by mass or less, more preferably 0.8 parts by mass or less. The amount of the esterification cocatalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0 with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. 0.5 parts by mass or less, more preferably 0.1 parts by mass or less.

The softening point of the polyester (a) is preferably 65 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 75 ° C. or higher, from the viewpoint of improving the heat-resistant storage stability of the toner. From the viewpoint of improving, it is preferably 95 ° C. or lower, more preferably 85 ° C. or lower, and still more preferably 80 ° C. or lower.
The softening point of the polyester (a) can be controlled by adjusting the types and composition ratios of the alcohol component and the carboxylic acid component, the amount of catalyst, and the like, and selecting reaction conditions such as reaction temperature, reaction time, and reaction pressure.

The glass transition temperature (Tg) of the polyester (a) is preferably less than 50 ° C., more preferably 46 ° C. or less, still more preferably 42 ° C. or less, from the viewpoint of low-temperature fixability of the toner. Preferably it is 38 degrees C or less. Further, from the viewpoint of improving the heat resistant storage stability of the toner, it is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, and further preferably 30 ° C. or higher.
The glass transition temperature of the polyester resin can be controlled by the type and composition ratio of the alcohol component and carboxylic acid component.

The acid value of the polyester (a) is preferably 5 mgKOH / g from the viewpoint of maintaining the reactivity with the oxazoline polymer compound of the present invention, the dispersion stability in the dispersion of the resin particles (A) and the charge amount of the toner. From the viewpoint of improving the charging stability of the toner, it is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, still more preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more. Is 25 mg KOH / g or less.
The hydroxyl value of the polyester (a) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and further preferably 15 mgKOH / g or more, from the viewpoint of improving the dispersion stability in the dispersion of the resin particles (A). From the viewpoint of improving the charging stability of the toner, it is preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less, and still more preferably 30 mgKOH / g or less.

  The acid value and hydroxyl value of the polyester can be controlled by adjusting the types and composition ratios of the alcohol component and carboxylic acid component, the amount of catalyst, and the like, and selecting reaction conditions such as reaction temperature, reaction time, and reaction pressure.

  The content of the polyester (a) in the resin particles (A) is such that the resin particles (A) are added from the viewpoint of facilitating emulsification of the resin containing the polyester (a) and enhancing the dispersion stability of the resin particles (A). In the constituting resin, it is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, still more preferably substantially 100% by mass, and still more preferably 100% by mass.

(Basic aqueous solution)
A basic aqueous solution is preferably used for emulsifying the resin containing the polyester (a).
The pH of the basic aqueous solution is 8.5 or more from the viewpoint of maintaining the charge amount of the toner, preferably 9.0 or more, more preferably 10.0 or more, still more preferably 11.0 or more, and still more preferably. Is 12.0 or more. From the same viewpoint, it is 13.5 or less, preferably 13.0 or less, more preferably 12.8 or less, and still more preferably 12.5 or less.

Examples of the basic compound used in the basic aqueous solution include inorganic basic compounds and organic basic compounds.
Examples of inorganic base compounds include hydroxides of alkali metals such as potassium, sodium and lithium, as well as carbonates and hydrogen carbonates. Specific examples thereof include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and carbonate. Examples thereof include sodium hydrogen and potassium hydrogen carbonate. Examples of the organic base include ammonia and alkanolamines such as diethylethanolamine.
Among these, potassium carbonate and sodium carbonate are preferable and potassium carbonate is more preferable from the viewpoint of maintaining the charge amount of the toner.
Further, from the viewpoint of controlling the pH of the basic aqueous solution without reducing the neutralization reaction efficiency, it is preferable to use a buffer solution obtained by mixing a strong base and a weak acid, and mixing potassium hydroxide and phosphoric acid. The buffer solution obtained by this is preferable.

  The concentration of the basic compound in the basic aqueous solution is preferably 1% by mass or more, more preferably 5% by mass or more, from the viewpoint of obtaining a resin particle (A) dispersion having a small particle size and a narrow particle size distribution. Preferably it is 8 mass% or more, Preferably it is 50 mass% or less, More preferably, it is 40 mass% or less, More preferably, it is 30 mass% or less.

The basic aqueous solution is mixed so that the acid groups of the polyester (a) are neutralized and the resin particles (A) can be stably dispersed. The neutralization degree of the resin particle (A) dispersion after mixing the basic aqueous solution is preferably 50 mol% or more from the viewpoint of obtaining a resin particle (A) dispersion having a small particle size and a narrow particle size distribution. More preferably, it is 70 mol% or more, More preferably, it is 80 mol% or more. Further, from the viewpoint of suppressing the hydrolysis of the polyester resin, it is preferably 200 mol% or less, more preferably 180 mol% or less, and still more preferably 160 mol% or less.
The degree of neutralization of the resin particle (A) dispersion can be calculated by the method described in the examples.

(Surfactant)
In emulsifying the resin containing the polyester (a), it is preferable to use a surfactant from the viewpoint of facilitating the emulsification of the resin containing the polyester (a) and enhancing the dispersion stability of the resin particles (A).
Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants. From the viewpoint of improving the dispersion stability of the resin particles (A), nonionic surfactants are preferable. More preferably, a nonionic surfactant and an anionic surfactant or a cationic surfactant are used in combination, and a nonionic surfactant and an anionic surfactant are more preferably used in combination.
When a nonionic surfactant and an anionic surfactant are used in combination, the mass ratio of the nonionic surfactant to the anionic surfactant (nonionic surfactant / anionic surfactant) is the resin particle ( From the viewpoint of improving the dispersion stability of A), it is preferably 0.1 or more, more preferably 0.3 or more, still more preferably 0.5 or more, and preferably 10 or less, more preferably 5 or less, More preferably, it is 2 or less.

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, oxyethylene / oxypropylene block copolymer, and the like. Dispersion stability of resin particles (A) From the viewpoint of improving the viscosity, polyoxyethylene alkyl ether is preferable.
Examples of the polyoxyethylene alkyl ether include polyoxyethylene oleyl ether and polyoxyethylene lauryl ether.
Examples of the polyoxyethylene alkyl aryl ether include polyoxyethylene nonyl phenyl ether.
Examples of the polyoxyethylene fatty acid ester include polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate and the like.

Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate, alkyl ether sulfate and the like. From the viewpoint of improving the dispersion stability of the resin particles (A), alkylbenzene sulfonate and alkyl ether Sulfate is preferred.
As the alkyl benzene sulfonate, an alkali metal salt of dodecyl benzene sulfonic acid is preferable, and sodium dodecyl benzene sulfonate is more preferable. As the alkyl sulfate, an alkali metal salt of dodecyl sulfate is preferable, and sodium dodecyl sulfate is more preferable. As the alkyl ether sulfate, an alkali metal salt of dodecyl ether sulfate is preferable, and sodium dodecyl ether sulfate is more preferable.

  Examples of the cationic surfactant include alkylbenzene trimethyl ammonium chloride, alkyl trimethyl ammonium chloride, dialkyl dimethyl ammonium chloride and the like.

  From the viewpoint of improving the dispersion stability of the resin particles (A), the amount of the surfactant added is preferably 0.1 parts by mass or more, more preferably 100 parts by mass of the resin constituting the resin particles (A). Is 0.5 parts by mass or more, more preferably 1 part by mass or more, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less.

(Coloring agent)
A coloring agent can be used individually by 1 type or in combination of 2 or more types.
Examples of the colorant used in the present invention include pigments and dyes, and pigments are preferable from the viewpoint of improving the image density of printed matter.
Examples of the pigment include a cyan pigment, a yellow pigment, a magenta pigment, and a black pigment.
The cyan pigment is preferably a phthalocyanine pigment, and more preferably copper phthalocyanine. The yellow pigment is preferably a monoazo pigment, isoindoline pigment or benzimidazolone pigment, and the magenta pigment is preferably a soluble azo pigment such as quinacridone pigment or BONA lake pigment, or an insoluble azo pigment such as naphthol AS pigment. The black pigment is preferably carbon black.
Examples of the dye include acridine dyes, azo dyes, benzoquinone dyes, azine dyes, anthraquinone dyes, indigo dyes, phthalocyanine dyes, aniline black dyes, and the like.
A coloring agent can be used individually by 1 type or in combination of 2 or more types.

  The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 3 parts by mass or more with respect to 100 parts by mass of the polyester (a) from the viewpoint of improving the image density of the toner. From the viewpoint of imparting low-temperature fixability to the toner, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less.

(Organic solvent)
The neutralized resin may contain an organic solvent as long as the effects of the present invention are not impaired.
Examples of the organic solvent include aliphatic alcohols having 1 to 5 carbon atoms such as methanol, ethanol and isopropanol; dialkyl ketones having an alkyl group having 1 to 3 carbon atoms such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran. It is done.
The content of the organic solvent in the resin neutralized product is 10% by mass or less, preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably substantially 0% by mass, and still more preferably 0%. % By mass.

(Aqueous medium)
As an aqueous medium, the thing which has water as a main component is preferable, and content of the water in an aqueous medium becomes like this from a viewpoint of improving the dispersion stability of a fat particle (A), Preferably it is 80 mass% or more, Preferably it is 90 mass. % Or more, more preferably 95% by mass or more, still more preferably substantially 100% by mass, and still more preferably 100% by mass. The water is preferably deionized water or distilled water.
Components other than water include aliphatic alcohols having 1 to 5 carbon atoms such as methanol, ethanol and isopropanol; dialkyl ketones having 1 to 3 carbon atoms in alkyl groups such as acetone and methyl ethyl ketone; cyclic ethers such as tetrahydrofuran, etc. An organic solvent that dissolves in water is used.

From the viewpoint of improving the dispersion stability of the resin particles (A), the temperature at which the aqueous medium is added is preferably not less than the glass transition temperature of the polyester (a) and preferably not more than the boiling point of the aqueous medium. Specifically, it is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, still more preferably 90 ° C. or higher, and preferably less than 100 ° C., more preferably 98 ° C. or lower.
The amount of the aqueous medium used is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and still more preferably from 100 parts by mass of the resin constituting the resin particles (A) from the viewpoint of improving the productivity of the toner. Is 150 parts by mass or more, preferably 2000 parts by mass or less, more preferably 1000 parts by mass or less, and still more preferably 500 parts by mass or less.

  The solid content concentration of the resin particle (A) dispersion is preferably 7% by mass or more, more preferably 10% by mass from the viewpoint of improving the productivity of the toner and improving the dispersion stability of the resin particles (A). More preferably, it is 20% by mass or more, more preferably 25% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 35% by mass or less. In addition, solid content is the total amount of non-volatile components, such as resin and surfactant.

The volume median particle size (D ₅₀ ) of the resin particles (A) in the resin particle (A) dispersion is preferably 20 nm or more, more preferably 50 nm or more, and still more preferably from the viewpoint of improving the low-temperature fixability of the toner. Is 100 nm or more, preferably 500 nm or less, more preferably 400 nm or less, and still more preferably 300 nm or less.
Here, the volume median particle size (D ₅₀ ) is determined by the method described in the examples.
Here, the volume average particle diameter (D _v ) is determined by the method described in Examples.
The coefficient of variation (CV value) (%) of the particle size distribution of the resin particles (A) is preferably 30% or less, more preferably 26% or less, and still more preferably 24% or less from the viewpoint of obtaining a high-quality toner. More preferably, it is 22% or less, still more preferably 20% or less. From the viewpoint of economy and ease of production, it is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more. . The CV value is determined by the method described in the examples.

[Step (2)]
Step (2) is a step in which the resin particles (A) obtained in step (1) are aggregated in an aqueous medium to obtain aggregated particles (I).
When aggregating the resin particle dispersion containing the resin particles (A), release agent particles containing a release agent, charge control agent particles containing a charge control agent, colorant particles containing a colorant, etc. It may be agglomerated.
The colorant is preferably contained in the resin particles (A) from the viewpoint of imparting low-temperature fixability to the toner. Further, from the viewpoint of improving the low-temperature fixability and high-temperature offset property of the toner, it is preferable that the release agent particles are aggregated together with the resin particles (A).

(Release agent particles)
In producing the release agent particles, it is preferable to contain a surfactant from the viewpoint of suppressing aggregation of the release agent particles. The content in the case of using a surfactant is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass with respect to 100 parts by mass of the release agent from the viewpoint of suppressing aggregation of the release agent particles. Part or more, more preferably 0.5 part by weight or more, and from the viewpoint of improving the chargeability of the toner, it is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 2 parts by weight or less. is there.
The volume median particle size of the release agent particles is preferably 100 nm or more, more preferably 200 nm or more, and preferably 1000 nm or less, more preferably, from the viewpoint of improving the charging stability and high-temperature offset resistance of the toner. Is 700 nm or less, more preferably 500 nm or less.
The CV value of the release agent particles is preferably 50% or less, more preferably 40% or less, still more preferably 35% or less from the viewpoint of obtaining a high-quality toner, and from the viewpoint of improving productivity. Preferably it is 15% or more, More preferably, it is 20% or more, More preferably, it is 25% or more.

(Release agent)
Release agents include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicone waxes; fatty acid amides such as oleic acid amides and stearic acid amides; plant waxes; animal waxes such as beeswax; mineral or petroleum waxes; esters Synthetic waxes such as waxes may be mentioned.
Examples of plant waxes include carnauba wax, rice wax, and candelilla wax. Carnauba wax is preferred from the viewpoint of improving the low-temperature fixability of the toner.
Examples of the mineral or petroleum-based wax include montan wax, paraffin wax, and Fischer-Tropsch wax. Paraffin wax is preferable from the viewpoint of improving the low-temperature fixability of the toner.
These release agents can be used alone or in combination of two or more, and it is preferable to use 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 further preferably 80 ° C. or higher from the viewpoint of improving the heat-resistant storage stability of the toner, and also improves the low-temperature fixability of the toner. From the viewpoint, it is preferably 100 ° C. or lower, more preferably 95 ° C. or lower, and still more preferably 90 ° C. or lower. When two or more types are used in combination, it is preferable that the melting point is 60 ° C. or higher and 90 ° C. or lower from the viewpoint of improving the low-temperature fixability of the toner.
In the present invention, the melting point of the release agent is determined by the method described in the examples. When two or more kinds are used in combination, the melting point of the release agent having the largest mass ratio among the release agents contained in the obtained toner is the melting point of the release agent in the present invention. When all have the same ratio, the lowest value is set.

  The amount of the release agent used is preferably 1 part by mass or more, more preferably 2 parts by mass or more with respect to 100 parts by mass of the resin in the toner, from the viewpoint of improving the releasability and low-temperature fixability of the toner. The amount is preferably 5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less from the viewpoint of improving the heat-resistant storage stability of the toner.

(Surfactant)
The dispersion of the release agent particles in the aqueous medium may be performed in the presence of a surfactant from the viewpoint of improving the dispersion stability of the release agent particles and obtaining uniform aggregated particles in the subsequent aggregation step. preferable.
As the surfactant, from the viewpoint of improving the dispersion stability of the release agent and improving the cohesiveness with the resin particles (A), a nonionic surfactant, an anionic surfactant, a cationic surfactant is used. An anionic surfactant is preferable, a carboxylate is more preferable, and a polycarboxylate and an alkenyl succinate are still more preferable.
From the viewpoint of improving the dispersion stability of the release agent, the amount of the surfactant used is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, with respect to 100 parts by mass of the release agent. More preferably, it is 0.5 parts by mass or more, and from the viewpoint of improving the cohesiveness with the resin particles (A), it is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 2 parts by mass. It is as follows.

(Manufacture of release agent particles)
The release agent particles are preferably obtained as a dispersion of release agent particles by dispersing the release agent in an aqueous medium.
The dispersion of the release agent particles is preferably obtained by dispersing the release agent and the aqueous medium using a disperser in the presence of a surfactant at a temperature equal to or higher than the melting point of the release agent. As the disperser to be used, a homogenizer, an ultrasonic disperser or the like is preferable.
A preferred embodiment of the aqueous medium used in the step (2) is the same as the aqueous medium used when emulsifying the resin containing the polyester (a) in the step (1).
The solid content concentration of the dispersion of the release agent particles is preferably 5% by mass or more, more preferably 10% from the viewpoint of improving the productivity of the toner and the dispersion stability of the resin particle (A) dispersion. It is at least 15% by mass, more preferably at least 15% by mass, preferably at most 40% by mass, more preferably at most 30% by mass, still more preferably at most 25% by mass. In addition, solid content is the total amount of non-volatile components, such as a mold release agent and surfactant.

When a release agent is included in the aggregated particles (I), first, the resin particles (A) and the release agent particles are mixed in an aqueous medium to obtain a mixed dispersion.
There is no restriction | limiting in order of mixing, You may add any in order and may add simultaneously.

From the viewpoint of improving the productivity of the toner, the resin particles (A) are preferably 10% by mass or more, more preferably 20% by mass or more in the mixed dispersion liquid. From the viewpoint of obtaining the aggregated particles (I), it is preferably 40% by mass or less, more preferably 30% by mass or less.
The aqueous medium is preferably 60% by mass or more, more preferably 70% by mass or more in the mixed dispersion, from the viewpoint of obtaining aggregation particles (I) having a desired particle size by controlling aggregation. From the viewpoint of improving productivity, it is preferably 90% by mass or less, more preferably 80% by mass or less.
From the viewpoint of improving the releasability and low-temperature fixability of the toner, the release agent particles are preferably 1 part by mass or more, more preferably 2 parts by mass or more, and still more preferably with respect to 100 parts by mass of the resin particles (A). Is 5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less from the viewpoint of improving the heat-resistant storage stability of the toner.
The mixing temperature is preferably 0 ° C. or higher and 40 ° C. or lower from the viewpoint of controlling aggregation and obtaining aggregated particles (I) having a desired particle size.

Next, the particles in the mixed dispersion are aggregated to obtain a dispersion of aggregated particles (I). From the viewpoint of efficiently performing the aggregation, it is preferable to add an aggregating agent.
The flocculant is preferably an electrolyte, and more preferably a salt, from the viewpoint of obtaining a toner having a desired particle diameter while preventing excessive aggregation.
As the aggregating agent, a quaternary salt cationic surfactant, an organic aggregating agent such as polyethyleneimine, and an inorganic aggregating agent such as an inorganic metal salt, an inorganic ammonium salt, or a bivalent or higher metal complex are used. From the viewpoint of improving the charging stability of the toner, inorganic flocculants are preferred, inorganic metal salts and inorganic ammonium salts are more preferred, and inorganic ammonium salts are even more preferred.
The valence of the cation of the inorganic flocculant is preferably from 1 to 5 and more preferably from 1 to 2 and more preferably from the viewpoint of obtaining a toner having a desired particle size while preventing excessive aggregation. Is monovalent.
Examples of the monovalent cation of the inorganic flocculant include sodium, potassium, and ammonium. Ammonium is preferable from the viewpoint of improving the charging stability of the toner.
Examples of the inorganic metal salt include metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate, and inorganic metal salt polymers such as polyaluminum chloride and polyaluminum hydroxide.
Examples of inorganic ammonium salts include ammonium sulfate, ammonium chloride, and ammonium nitrate.
As the flocculant, ammonium sulfate is more preferable.

  The amount of the flocculant used is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, more preferably 40 parts by mass or less, based on 100 parts by mass of the resin constituting the resin particles (A) from the viewpoint of improving the charging stability of the toner. Preferably it is 30 mass parts or less. Further, from the viewpoint of controlling the aggregation of the resin particles (A) to obtain a desired particle size, it is preferably 1 part by mass or more, more preferably 5 parts by mass with respect to 100 parts by mass of the resin constituting the resin particles (A). Part or more, more preferably 10 parts by weight or more.

The flocculant is added continuously to the mixture dispersion. The flocculant may be added at one time, or may be added intermittently or continuously, but from the viewpoint of obtaining the desired particle size by controlling the aggregation of the resin particles (A), the addition and completion of the addition It is preferable to perform sufficient stirring later.
The flocculant is preferably added dropwise as an aqueous solution from the viewpoint of controlling the aggregation of the resin particles (A) to obtain a desired particle size. The concentration of the aqueous solution of the flocculant is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more, from the viewpoint of controlling the aggregation of the resin particles (A) to obtain a desired particle size. Moreover, it is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 15% by mass or less.

As an aggregating method, the aggregating agent is preferably continuously added as an aqueous solution to a container containing the mixed dispersion. The flocculant may be added at one time, or may be added intermittently or continuously. However, it is preferable to perform sufficient stirring at the time of addition and after completion of the addition.
The dropping time of the flocculant is preferably 1 minute or more, more preferably 2 minutes or more, and further preferably 3 minutes or more from the viewpoint of controlling aggregation and obtaining a desired particle size. From the viewpoint of improvement, it is preferably 120 minutes or less, more preferably 60 minutes or less, still more preferably 30 minutes or less, and even more preferably 10 minutes or less.
Further, the temperature at which the flocculant is dropped is preferably 0 ° C. or higher, more preferably 10 ° C. or higher from the viewpoint of improving toner productivity, and from the viewpoint of controlling the aggregation to obtain a desired particle size. The temperature is preferably 50 ° C. or lower, more preferably 40 ° C. or lower, and still more preferably 30 ° C. or lower.
Furthermore, from the viewpoint of promoting aggregation and obtaining aggregated particles (I) having a desired particle size and particle size distribution, it is preferable to increase the temperature of the dispersion after adding the flocculant. As temperature to maintain, 50 to 70 degreeC is preferable.

  The total amount of the resin particles (A) is added, and the aggregation is stopped when the toner particles grow to an appropriate particle size. As the particle size for stopping the aggregation, the volume-median particle size of the aggregated particles (I) is preferably 2 μm or more, more preferably 3 μm or more, and further preferably 4 μm or more, from the viewpoint of obtaining low-temperature fixability of the toner. Moreover, it is preferably 10 μm or less, more preferably 8 μm or less, and still more preferably 6 μm or less.

  Examples of the method for stopping the aggregation include a method of cooling the dispersion, a method of adding an aggregation stopper, and a method of diluting the dispersion. From the viewpoint of reliably preventing unnecessary aggregation, the aggregation stopper A method of stopping the aggregation by adding is preferable.

As the aggregation terminator, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include alkyl ether sulfates, alkyl sulfates, and linear alkylbenzene sulfonates. The aggregation terminators can be used alone or in combination of two or more.
The addition amount of the aggregation terminator is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, further with respect to 100 parts by mass of the resin particles (A), from the viewpoint of reliably preventing unnecessary aggregation. Preferably, it is 2 parts by mass or more, and from the viewpoint of reducing the residual of the aggregation terminator in the toner and improving the charging stability of the toner, it is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, Preferably it is 6 mass parts or less. The aggregation terminator is preferably added as an aqueous solution from the viewpoint of improving productivity.

  The temperature at which the aggregation terminator is added is preferably the same as the temperature at which the aggregated particle (I) dispersion is retained, and is preferably 50 ° C. or higher and 70 ° C. or lower from the viewpoint of improving toner productivity.

The volume median particle size of the obtained aggregated particles (I) is preferably 1 μm or more, more preferably 2 μm or more, still more preferably 3 μm or more, and preferably 10 μm from the viewpoint of maintaining the charge amount of the toner. Hereinafter, it is more preferably 8 μm or less, and further preferably 6 μm or less.
The CV value is preferably 30% or less, more preferably 28% or less, and still more preferably 25% or less from the viewpoint of obtaining a high-quality toner.

[Step (3)]
In the step (3), the resin particles (C) containing the amorphous polyester (c) having at least an acid group and having a glass transition temperature of 55 ° C. or higher are obtained from the aggregated particles obtained in the step (2) ( This is a step of agglomerating on the surface of I) to obtain aggregated particles (II).

(Amorphous polyester (c))
The amorphous polyester (c) is not particularly limited as long as it has at least an acid group, has a glass transition temperature (Tg) of 55 ° C. or higher, and is an amorphous polyester.
Here, the polyester is amorphous means the ratio between the softening point and the maximum peak temperature of the endotherm measured by a differential scanning calorimeter (DSC), (softening point (° C.)) / (Maximum endothermic peak temperature (° C.)). The crystallinity index defined by) is greater than 1.4 or less than 0.6.
From the viewpoint of improving the heat-resistant storage stability of the toner, the crystallinity index of the amorphous polyester (c) is preferably less than 0.6 or more than 1.4 and less than 4, more preferably less than 0.6 or 1.5. It is 4 or less, more preferably less than 0.6 or 1.5 or more and 3 or less, and still more preferably less than 0.6 or 1.5 or more and 2 or less. The crystallinity index of the polyester can be appropriately determined depending on the production conditions such as the type and ratio of the raw material monomers, the reaction temperature, the reaction time, and the cooling rate.

Further, as already described in the description of the polyester (a), the SP value (SPc) of the amorphous polyester (c) is 0.6 (SP) different from the SP value (SPa) of the polyester (a). It is less than 1.8.
Although it varies depending on the combination of the polyester (a) and the amorphous polyester (c), SPc is preferably 9.0 or more, more preferably 10.5, from the viewpoint of easy synthesis of the amorphous polyester (c). It is 0 or more, more preferably 11.0 or more. From the same viewpoint, the upper limit of SPc is preferably 13.0 or less, more preferably 12.5 or less, and still more preferably 12.0 or less.

The amorphous polyester (c) preferably has at least an acid group and an acid group at the molecular end. Examples of the acid group include acid groups that the polyester (a) may have. Among these, a carboxy group is preferable from the viewpoint of facilitating emulsification of the resin containing the amorphous polyester (c).
The amorphous polyester (c) is produced by polycondensing a carboxylic acid component and an alcohol component, if necessary, in the presence of an esterification catalyst, a polymerization inhibitor or the like, preferably at 180 ° C. or higher and 250 ° C. or lower. be able to.

As a carboxylic acid component, the carboxylic acid component mentioned as a raw material monomer of polyester (a) can be preferably used alone or in combination of two or more.
Among them, from the viewpoint of heat resistant storage stability of the toner, preferably, at least one of aliphatic dicarboxylic acid and aromatic dicarboxylic acid and acid anhydrides thereof, more preferably fumaric acid, phthalic acid, terephthalic acid, and acid anhydrides thereof. Species, more preferably at least one of fumaric acid and terephthalic acid and their anhydrides.
Further, the ratio of the aromatic dicarboxylic acid and the acid anhydride in 100 mol% of the total of the aliphatic dicarboxylic acid and the acid anhydride and the aromatic dicarboxylic acid and the acid anhydride is determined from the viewpoint of heat resistant storage stability of the toner. Therefore, it is preferably 60 mol% or more, more preferably 64 mol% or more, still more preferably 68 mol% or more, and preferably 80 mol% or less.

As an alcohol component, the alcohol component similar to the alcohol component quoted as a raw material monomer of polyester (a) can be used individually or in combination of 2 or more types, and a preferable aspect is also the same.
The amorphous polyester (c) is a polyester obtained by polycondensing a carboxylic acid component containing at least one of terephthalic acid and its acid anhydride and an alcohol component from the viewpoint of improving the heat-resistant storage stability of the toner. Is preferred.
The equivalent ratio of the carboxylic acid component and the alcohol component in the amorphous polyester (c), the polycondensation reaction of the alcohol component and the carboxylic acid component, the esterification catalyst that can be used in the reaction, and the embodiment of the esterification catalyst are polyester (a) The preferred embodiments are also the same.

The glass transition temperature (Tg) of the amorphous polyester (c) is 55 ° C. or higher, preferably 57 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of improving the heat resistant storage stability of the toner. From the viewpoint of low-temperature fixability, it is preferably 70 ° C. or lower, and more preferably 67 ° C. or lower.
The softening point of the amorphous polyester (c) is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and still more preferably 90 ° C. or higher, from the viewpoint of improving the heat resistant storage stability of the toner. From this viewpoint, it is preferably 150 ° C. or lower, more preferably 135 ° C. or lower, and further preferably 120 ° C. or lower.

The acid value of the amorphous polyester (c) is preferably 6 mgKOH / g from the viewpoint of improving the reactivity with the oxazoline polymer compound of the present invention and the emulsifiability of the resin containing the amorphous polyester (c). As mentioned above, More preferably, it is 10 mgKOH / g or more, More preferably, it is 15 mgKOH / g or more. From the same viewpoint, the upper limit of the acid value of the amorphous polyester (c) is preferably 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and further preferably 25 mgKOH / g or less.
The hydroxyl value of the amorphous polyester (c) is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more, still more preferably 20 mgKOH, from the viewpoint of improving the dispersion stability in the dispersion of the resin particles (C). From the viewpoint of improving the charging stability of the toner, it is preferably 45 mgKOH / g or less, more preferably 40 mgKOH / g or less.

The content of the amorphous polyester (c) in the resin particles (C) is preferably 70% by mass or more in the resin constituting the resin particles (C) from the viewpoint of improving the heat-resistant storage stability of the toner. Is 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably substantially 100% by mass, and still more preferably 100% by mass.
The resin particles (C) may contain, in addition to the amorphous polyester (c), well-known resins usually used for toners, for example, resins such as styrene-acrylic copolymers, epoxy resins, polycarbonates, and polyurethanes. Good.
The resin particles (C) can be obtained by the same method as the method for producing the resin particles (A), but the same basic aqueous solution, surfactant and aqueous medium can be preferably used.

The volume median particle size (D ₅₀ ) of the resin particles (C) in the dispersion containing the obtained resin particles (C) is preferably 70 nm or more, more preferably 85 nm or more, and further preferably 100 nm or more. Moreover, it is preferably 200 nm or less, more preferably 170 nm or less, and still more preferably 140 nm or less.
Further, the coefficient of variation (CV value) (%) of the particle size distribution of the resin particles (C) is preferably 40% or less, more preferably 37% or less, and more preferably 34% or less from the viewpoint of obtaining a high-quality toner. Is more preferably 31% or less, more preferably 5% or more, more preferably 10% or more, and still more preferably 15% or more from the viewpoint of economy and ease of production. The volume median particle size and CV value of the resin particles (C) are determined by the same method as that for the resin particles (A), and specifically, the methods described in the examples.

  The solid content concentration of the resin particles (C) in the dispersion containing the resin particles (C) is preferably 7 from the viewpoint of improving the stability of the obtained resin particle dispersion and facilitating handling. It is at least 10 mass%, more preferably at least 10 mass%, still more preferably at least 20 mass%, preferably at most 50 mass%, more preferably at most 40 mass%, still more preferably at most 35 mass%.

In step (3), a dispersion (resin particles (C)) containing resin particles (C) in a dispersion (aggregated particles (I) dispersion) containing aggregated particles (I) obtained in step (2). Add dispersion).
When the resin particle (C) dispersion is added to the aggregated particle (I) dispersion, the aggregating agent may be used in order to efficiently aggregate the resin particles (C) in the aggregated particles (I).
As a preferable addition method in the case of adding the resin particle (C) dispersion to the aggregated particle (I) dispersion, a method of simultaneously adding the coagulant and the resin particle (C) dispersion, the coagulant and the resin particle (C ) A method of adding the dispersion liquid alternately, and a method of adding the resin particle (C) dispersion liquid while gradually raising the temperature of the aggregated particle (I) dispersion liquid. By doing in this way, the cohesiveness fall of the aggregated particle (I) and the resin particle (C) by the coagulant | flocculant density | concentration fall can be prevented. From the viewpoint of improving the productivity of the toner and from the viewpoint of easy production, it is preferable to add the resin particle (C) dispersion while gradually raising the temperature of the aggregated particle (I) dispersion.

  The addition amount of the resin particles (C) is selected from the viewpoints of improving the low temperature fixability of the toner, improving the heat resistant storage stability, and suppressing the scattering of the toner in a printer such as a printer. The mass ratio with the resin particles (A) (resin particles (C) / resin particles (A)) is preferably 0.1 to 1.5, more preferably 0.2 to 1.0, still more preferably 0.00. An amount of 3 to 0.75 is preferred.

  The resin particle (C) dispersion may be added continuously over a certain period of time, may be added at a time, or may be added in a plurality of divided portions. It is preferable to add them continuously or in several divided portions. By adding as described above, the resin particles (C) are likely to selectively adhere to the aggregated particles (I). Among these, it is preferable to add continuously over a certain time from the viewpoint of promoting selective adhesion and the efficiency of production. The time for continuous addition is preferably 1 hour or more, more preferably 3 hours or more from the viewpoint of obtaining uniform aggregated particles (II) and shortening the production time, and from the same viewpoint, preferably Is 10 hours or less, more preferably 8 hours or less.

  The volume median particle size of the aggregated particles (II) obtained in the step (3) is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 3 μm or more, and still more preferably from the viewpoint of obtaining a high-quality toner. 4 μm or more. Further, from the same viewpoint, the volume median particle size of the aggregated particles (II) is preferably 10 μm or less, more preferably 9 μm or less, and further preferably 6 μm. The volume-median particle size of the aggregated particles (II) is specifically determined by the method described in the examples.

[Addition of polymer compound containing at least two oxazoline groups]
In this invention, it has the process of adding the high molecular compound (oxazoline high molecular compound of this invention) containing an at least 2 oxazoline group before a process (3).
By having such a process, the resin containing the polyester (a) functioning as the core resin and the resin containing the amorphous polyester (c) functioning as the shell resin are combined by chemical bonding. By using the oxazoline polymer compound of the present invention, the phase-separated resins can be chemically bonded to stably maintain the core-shell structure of the toner, and the bond between the core resin and the shell resin is strong. Can be. Therefore, a physically strong toner can be obtained, and even in an environment where continuous printing (for example, 500 sheets printing) is performed, the core-shell structure of the toner is not easily broken, and both heat resistant storage stability and high charge amount maintenance can be achieved. .
The addition time of the oxazoline polymer compound of the present invention is the step (1), after the step (1) and before the step (2), during the step (2), after the step (2) and after the step (3). It may be added only at any addition time, or may be added at each of a plurality of addition times.
Among these, from the viewpoint of easily maintaining the core-shell structure of the toner, the addition time of the oxazoline polymer compound of the present invention is preferably before step (2), more preferably during step (1), and further preferably step (1). ) And after emulsification of the resin containing polyester (a).

The addition amount of the oxazoline polymer compound of the present invention is such that the number of moles of oxazoline groups of the oxazoline polymer compound of the present invention relative to the number of moles of acid groups in the polyester (a) from the viewpoint of easily maintaining the core-shell structure of the toner. The range is 0.02 equivalents or more and 0.45 equivalents or less. Hereinafter, “the number of moles of the oxazoline group of the oxazoline polymer compound of the present invention relative to the number of moles of the acid group in the polyester (a)” is referred to as “Oxz equivalent”.
When the Oxz equivalent is 0.02 equivalent (Eq) or more, the reaction between the oxazoline group and the acid group in the polyester (a) and the acid group of the amorphous polyester (c) added later easily proceeds. It is easy to form a stable core-shell structure. Further, when the Oxz equivalent is 0.45 equivalent (Eq) or less, the exposure of the oxazoline polymer compound of the present invention to the toner surface can be suppressed, and the reduction in the charge amount of the toner can be suppressed.
The Oxz equivalent is preferably 0.025 equivalent or more, more preferably 0.03 equivalent or more, and still more preferably 0.05 equivalent or more. Further, the upper limit of Oxz equivalent is preferably 0.35 equivalent or less, more preferably 0.25 equivalent or less, and still more preferably 0.15 equivalent or less.

The number of oxazoline groups of the oxazoline polymer compound of the present invention may be 2 or more per molecule, and may be 3 or more.
The content of the oxazoline group in the oxazoline polymer compound of the present invention can be measured by ¹ HNMR in CDCl ₃ , and the wax is released from the binder resin having a carboxy group during the production of the toner. From the viewpoint of suppression, it is preferably 0.1 mmol / g or more, more preferably 0.5 mmol / g or more, still more preferably 1 mmol / g or more, and from the viewpoint of reaction density, preferably 50 mmol / g or less, more preferably 20 mmol. / G or less, more preferably 10 mmol / g or less.

  The oxazoline polymer compound of the present invention can be obtained, for example, by polymerizing a polymerizable monomer having an oxazoline group, and if necessary, a polymerizable monomer having an oxazoline group and the oxazoline group It can also be obtained by copolymerization of a polymerizable monomer having a copolymerizable monomer. Here, the polymerizable monomer copolymerizable with the polymerizable monomer having an oxazoline group includes both a polymerizable monomer having an oxazoline group and a polymerizable monomer having no oxazoline group. be able to.

  The polymerizable monomer having an oxazoline group is not particularly limited, but 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, From 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, etc. At least one selected can be used. Among these, 2-isopropenyl-2-oxazoline is preferable from the viewpoint of availability.

Among the polymerizable monomers copolymerizable with the polymerizable monomer having an oxazoline group, the polymerizable monomer having no oxazoline group is not particularly limited, but (meth) acrylic acid ester, (meta ) Acrylic acid and its salts, unsaturated nitriles, unsaturated amides, vinyl esters, vinyl ethers, α-olefins, halogen-containing α, β-unsaturated aliphatic hydrocarbons, α, β-unsaturated aromatic hydrocarbons, etc. At least one of the above can be used.
The oxazoline polymer compound of the present invention preferably has a structural unit derived from (meth) acrylic acid and (meth) acrylic acid ester from the viewpoint of maintaining the charge amount of the toner and improving the heat-resistant storage stability of the toner. .

  The number average molecular weight of the oxazoline polymer compound of the present invention is not particularly limited, but is preferably 500 or more, more preferably 1,000 or more from the viewpoint of the reaction efficiency of the oxazoline group and the charge amount of the toner. From the viewpoint of quantity, it is preferably 2,000,000 or less, more preferably 1,000,000 or less, still more preferably 10,000,000 or less, and still more preferably 50,000 or less.

  As a commercially available product generally used as the oxazoline polymer compound of the present invention, EPOCROSS WS series (water-soluble type), K series (emulsion type) manufactured by Nippon Shokubai Co., Ltd. can be used.

[Step (4)]
In the step (4), the aggregated particles (II) obtained in the step (3) are held in the range of the glass transition temperature −5 ° C. to the glass transition temperature + 10 ° C. of the amorphous polyester (c). This is a step of fusing (II) to obtain core-shell particles. Through the step (4), the particles in the agglomerated particles (II), which are mainly physically attached to each other, are fused and united to form core-shell toner particles (core-shell particles). The At this time, due to the oxazoline polymer compound of the present invention interposed between the core resin and the shell resin, the bonding between the core resin and the shell resin proceeds more sufficiently, and the core-shell structure of the toner particles is more easily maintained.
When the glass transition temperature of the amorphous polyester (c) is “Tgs”, the retention temperature of the aggregated particles (II) can be expressed as (Tgs−5) ° C. or more and (Tgs + 10) ° C. or less.

From the viewpoint of promoting fusing and improving toner productivity, the retention temperature of the aggregated particles (II) is preferably (Tgs-3) ° C. or higher, more preferably (Tgs) ° C. or higher, and still more preferably (Tgs + 1). ) That's it. From the viewpoint of controlling the shape of the toner, the retention temperature of the aggregated particles (II) is preferably (Tgs + 8) ° C. or less, more preferably (Tgs + 6) ° C. or less, and further preferably (Tgs + 5) ° C. or less.
Further, from the viewpoint of improving the low-temperature fixability of the toner, in step (4), the temperature is preferably maintained at a temperature not higher than the melting point of the release agent, more preferably not higher than 3 ° C., more preferably not higher than 5 ° C. To do. When the toner contains a plurality of release agents, the release agent having the highest melting point is used as a reference.
The holding time in the step (4) is preferably 3 minutes or more, more preferably 5 minutes or more, and further preferably 8 minutes or more from the viewpoint of reliably fusing the agglomerated particles. From the viewpoint of improving, it is preferably 10 hours or less, more preferably 5 hours or less, still more preferably 3 hours or less, and even more preferably 1.5 hours or less.

The volume median particle size of the core-shell particles obtained in the step (4) is preferably 2 μm or more, more preferably 3 μm or more, and still more preferably from the viewpoint of improving the charging stability of the toner and obtaining a high-quality image. It is 4 μm or more, preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less.
In addition, it is preferable that the average particle diameter of the core-shell particle obtained by a process (4) is below the average particle diameter of aggregated particle (II). That is, in this step, it is preferable that aggregation and fusion between the aggregated particles (II) do not occur.

(Post-processing process)
In the present invention, a post-treatment step may be performed after step (4), and it is preferable to obtain core-shell particles by isolation.
Since the core-shell particles obtained in the step (4) are present in the aqueous medium, it is preferable to first perform solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used.
It is preferable to perform washing after the solid-liquid separation. When a nonionic surfactant is used in the production of the resin particles, it is preferable to remove the added nonionic surfactant, and therefore it is preferable to wash with an aqueous solution below the cloud point of the nonionic surfactant. . The washing is preferably performed a plurality of times.

  Next, although it is preferable to perform drying, it is preferable that the temperature at the time of drying is such that the temperature of the core-shell particles themselves is 5 ° C. or more lower than the glass transition temperature of the polyester, and preferably 10 ° C. or more. More preferred. As a drying method, it is preferable to use a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like. The water content after drying is preferably adjusted to 1.5% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of improving the charging stability of the toner.

<Toner for electrophotography>
The toner particles obtained by drying the core-shell particles can be used as they are as the electrophotographic toner of the present invention. However, the toner particles whose surface is treated as described below can be used as the electrophotographic toner. preferable.
The volume median particle size of the toner (particles) is preferably 2 μm or more, more preferably 3 μm or more, and further preferably 4 μm or more, from the viewpoint of improving the charging stability of the toner and obtaining a high-quality image. Further, it is preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less.
The CV value of the toner (particles) is preferably 30% or less, more preferably 28% or less, and further preferably 26% or less from the viewpoint of obtaining a high-quality toner, and from the viewpoint of improving toner productivity. Therefore, it is preferably 15% or more, more preferably 18% or more.
BET specific surface area by nitrogen adsorption method of the toner (particles) maintains the charge of the resulting toner, from the viewpoint of improving the heat-resistant storage stability, preferably 1.0 m ² / g or more, more preferably 1.1 m ² / G or more. From the same viewpoint, the BET specific surface area is preferably 2.5 m ² / g or less, more preferably 2.0 m ² / g or less, and still more preferably 1.9 m ² / g or less.
The degree of circularity of the toner (particles) is preferably 0.965 or more, more preferably 0.968 or more, and further preferably 0.970 or more, from the viewpoint of improving the heat resistant storage stability of the toner. From the same viewpoint, the circularity of the toner (particles) is preferably 0.990 or less, more preferably 0.985 or less, and still more preferably 0.980 or less.

(External additive)
In the electrophotographic toner of the present invention, the toner particles can be used as the toner as they are, but it is preferable to use a toner obtained by adding a fluidizing agent or the like to the toner particle surface as an external additive.
Examples of the external additive include hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, inorganic fine particles such as 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 added is preferably 1 part by mass or more, more preferably 2 parts by mass or more with respect to 100 parts by mass of the toner particles. , Preferably 5 parts by mass or less, more preferably 4 parts by mass or less.

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

  With respect to the above-described embodiment, the present invention discloses the following method for producing an electrophotographic toner.

<1> Step (1): Step of obtaining resin particles (A) by emulsifying a resin containing at least an acid group-containing polyester (a),
Step (2): a step of aggregating the resin particles (A) in an aqueous medium to obtain agglomerated particles (I);
Step (3): The resin particles (C) containing at least an acid group and containing an amorphous polyester (c) having a glass transition temperature of 55 ° C. or higher are aggregated on the surface of the aggregated particles (I). Obtaining aggregated particles (II), and
Step (4): The aggregated particles (II) are fused within the range of the glass transition temperature of the amorphous polyester (c) from −5 ° C. to the glass transition temperature + 10 ° C. And obtaining a core-shell particle, a method for producing an electrophotographic core-shell toner comprising:
Before the step (3), the polymer compound containing at least two oxazoline groups has a molar number of oxazoline groups of the polymer compound of 0.02 equivalents or more relative to the number of acid groups in the polyester (a). Having a step of adding in a range of 0.45 equivalent or less,
A method for producing an electrophotographic toner, wherein a difference in solubility parameter (SP value) between the polyester (a) and the amorphous polyester (c) by a Fedors method is 0.6 or more and less than 1.8.

<2> The production of the electrophotographic toner according to <1>, wherein the acid group of the polyester (a) is a carboxy group, a sulfonic acid group, a phosphonic acid group, or a sulfinic acid group, preferably a carboxy group. Method.
<3> The difference (ΔSP) in solubility parameter (SP value) by the Fedors method between the polyester (a) and the amorphous polyester (c) is preferably 0.7 or more, more preferably 0.8 or more. More preferably, it is 0.9 or more, more preferably 1.0 or more, preferably 1.5 or less, more preferably 1.4 or less, still more preferably 1.3 or less. <1> or <2> The method for producing an electrophotographic toner according to <2>.
<4> The solubility parameter (SPa) of the polyester (a) by the Fedors method is preferably 8.0 or more, more preferably 9.0 or more, still more preferably 10.0 or more, and preferably 12. The method for producing an electrophotographic toner according to any one of <1> to <3>, which is 0 or less, more preferably 11.5 or less, and still more preferably 11.0 or less.
<5> The acid value of the polyester (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 The method for producing an electrophotographic toner according to any one of <1> to <4>, wherein the toner is 30 mg KOH / g or less, more preferably 25 mg KOH / g or less.
<6> The method for producing an electrophotographic toner according to any one of <1> to <5>, wherein the polyester (a) is obtained by condensation polymerization of a carboxylic acid component and an alcohol component.
<7> The carboxylic acid component is preferably an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid and their acid anhydrides, more preferably fumaric acid, alkenyl succinic acid, phthalic acid, trimellitic acid and isophthalic acid, and their acids. The method for producing an electrophotographic toner according to <6>, which is at least one of anhydrides.
<8> The alcohol component is preferably at least one of an aliphatic diol having 2 to 4 carbon atoms and an aromatic diol, and more preferably an aliphatic diol having 2 to 4 carbon atoms and an alkylene of bisphenol A ( 2 or more and 3 or less carbon atoms) oxide (average addition mole number of 1 or more and 16 or less) adduct, more preferably ethylene glycol, 1,2-propanediol, neopentyl glycol, 1,4-butanediol 1,3-butanediol, 2,3-butanediol, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2- <6> or <7>, which is at least one selected from the group consisting of bis (4-hydroxyphenyl) propane A method for producing the electrophotographic toner according to claim.
<9> The equivalent ratio (COOH group / OH group) of the carboxylic acid component and the alcohol component in the polyester (a) is preferably 0.80 or more, more preferably 0.85 or more, and preferably Is 1.10 or less, more preferably 1.05 or less, The method for producing an electrophotographic toner according to any one of <6> to <8>.
<10> The polyester (a) is obtained by condensation polymerization of a carboxylic acid component containing at least one of alkenyl succinic acid and acid anhydride thereof and an alcohol component, according to any one of <7> to <9>. Manufacturing method of electrophotographic toner.
<11> The glass transition temperature (Tg) of the polyester (a) is preferably less than 50 ° C., more preferably 46 ° C. or less, still more preferably 42 ° C. or less, and even more preferably 38 ° C. or less. The method for producing an electrophotographic toner according to any one of <1> to <10>, which is preferably 20 ° C. or higher, more preferably 25 ° C. or higher, and further preferably 30 ° C. or higher.

<12> The content of the polyester (a) in the resin particles (A) is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably in the resin constituting the resin particles (A). Is 95% by mass or more, more preferably substantially 100% by mass, and still more preferably 100% by mass. The method for producing an electrophotographic toner according to any one of <1> to <11>.
<13> The volume median particle size (D ₅₀ ) of the resin particles (A) is preferably 20 nm or more, more preferably 50 nm or more, still more preferably 100 nm or more, and preferably 500 nm or less, more preferably The method for producing an electrophotographic toner according to any one of <1> to <12>, which is 400 nm or less, more preferably 300 nm or less.

<14> Any one of <1> to <13>, wherein the acid group of the amorphous polyester (c) is a carboxy group, a sulfonic acid group, a phosphonic acid group, or a sulfinic acid group, and preferably a carboxy group. A method for producing the toner for electrophotography according to claim 1.
<15> The solubility parameter (SPc) of the amorphous polyester (c) by the Fedors method is preferably 9.0 or more, more preferably 10.0 or more, still more preferably 11.0 or more, and preferably Is 13.0 or less, more preferably 12.5 or less, and still more preferably 12.0 or less. The method for producing an electrophotographic toner according to any one of <1> to <14>.
<16> The glass transition temperature (Tg) of the amorphous polyester (c) is preferably 57 ° C. or higher, more preferably 60 ° C. or higher, and preferably 70 ° C. or lower, more preferably 67 ° C. The method for producing an electrophotographic toner according to any one of <1> to <15>, which is as follows.
<17> The acid value of the amorphous polyester (c) is preferably 6 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, and preferably 35 mgKOH / g or less, The method for producing an electrophotographic toner according to any one of <1> to <16>, more preferably 30 mgKOH / g or less, and still more preferably 25 mgKOH / g or less.
<18> The method for producing an electrophotographic toner according to any one of <1> to <17>, wherein the amorphous polyester (c) is obtained by condensation polymerization of a carboxylic acid component and an alcohol component.
<19> The carboxylic acid component is preferably aliphatic dicarboxylic acid and aromatic dicarboxylic acid and acid anhydrides thereof, more preferably at least one of fumaric acid, phthalic acid, terephthalic acid and acid anhydrides thereof, More preferably, the method for producing an electrophotographic toner according to <18>, which is at least one of fumaric acid, terephthalic acid, and acid anhydrides thereof.
<20> The alcohol component is preferably at least one of an aliphatic diol having 2 to 4 carbon atoms and an aromatic diol, and more preferably an aliphatic diol having 2 to 4 carbon atoms and an alkylene of bisphenol A ( 2 or more and 3 or less carbon atoms) oxide (average addition mole number of 1 or more and 16 or less) adduct, more preferably ethylene glycol, 1,2-propanediol, neopentyl glycol, 1,4-butanediol 1,3-butanediol, 2,3-butanediol, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2- <18> or <1 which is at least one selected from the group consisting of bis (4-hydroxyphenyl) propane The method for producing an electrophotographic toner according to 9>.
<21> Any one of <18> to <20>, wherein the amorphous polyester (c) is obtained by condensation polymerization of a carboxylic acid component containing at least one of terephthalic acid and an acid anhydride thereof and an alcohol component. A process for producing an electrophotographic toner as described in 1 above.

<22> The content of the amorphous polyester (c) in the resin particles (C) is preferably 70% by mass or more, more preferably 80% by mass or more in the resin constituting the resin particles (C). More preferably, it is 90% by mass or more, more preferably 95% by mass or more, still more preferably substantially 100% by mass, and still more preferably 100% by mass, according to any one of <1> to <21>. Manufacturing method of electrophotographic toner.
<23> The volume median particle size (D ₅₀ ) of the resin particles (C) is preferably 70 nm or more, more preferably 85 nm or more, still more preferably 100 nm or more, and preferably 200 nm or less, more preferably The method for producing an electrophotographic toner according to any one of <1> to <22>, which is 170 nm or less, more preferably 140 nm or less.
<24> The mass ratio of the resin particles (C) to the resin particles (A) (resin particles (C) / resin particles (A)) is preferably 0.1 to 1.5, more preferably 0.8. The method for producing an electrophotographic toner according to any one of <1> to <23>, wherein the amount is 2 to 1.0, more preferably 0.3 to 0.75.

<25> The method for producing an electrophotographic toner according to any one of <1> to <24>, wherein the polymer compound has structural units derived from (meth) acrylic acid and (meth) acrylic acid ester.
<27> The amount of the polymer compound added is such that the number of moles of the oxazoline group of the polymer compound with respect to the number of moles of acid groups in the polyester (a) is preferably 0.025 equivalents or more, more preferably 0.03 equivalents. More preferably, it is 0.05 equivalent or more, preferably 0.35 equivalent or less, more preferably 0.25 equivalent or less, still more preferably 0.15 equivalent or less, <1> to <26>. The method for producing an electrophotographic toner according to any one of the above.

<28> The retention temperature of the aggregated particles (II) in the step (4) is preferably a glass transition temperature (Tgs) of the amorphous polyester (c) of −3 ° C. or higher, more preferably Tgs ° C. or higher. The toner for electrophotography according to any one of <1> to <27>, more preferably Tgs + 1 ° C. or more, preferably Tgs + 8 ° C. or less, more preferably Tgs + 6 ° C. or less, and further preferably Tgs + 5 ° C. or less. Manufacturing method.

  Each property value of polyester, resin particles, toner, etc. was measured and evaluated by the following method.

[Acid value and hydroxyl value of polyester]
It measured according to JIS K0070. However, the measurement solvent was chloroform.

[Polyester solubility parameter (SP value)]
The solubility parameter (SP value) of the polyester was calculated based on the Fedors equation [δ = (ΣΔei / ΣΔvi) ^1/2 ] described above.

[Softening point of polyester or toner, maximum peak temperature of endotherm, and glass transition temperature]
(1) Softening point Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a 1 g sample was heated at a heating rate of 6 ° C./min, and a load of 1.96 MPa was applied by a plunger. The nozzle was extruded from a nozzle having a diameter of 1 mm and a length of 1 mm. The amount of plunger drop 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) Maximum endothermic peak temperature and glass transition temperature Using a differential scanning calorimeter “Pyris 6 DSC” (manufactured by PerkinElmer), the temperature is increased to 200 ° C., and the temperature is decreased to 0 ° C. at a temperature decreasing rate of 50 ° C./min. The measured samples were measured at a heating rate of 10 ° C./min. Of the endothermic peaks observed, the peak temperature having the maximum peak area was defined as the maximum endothermic peak temperature.
When the endothermic peak is observed when the measurement target is amorphous polyester, the temperature of the peak is observed, and when the step is observed without the peak being observed, a tangent indicating the maximum slope of the curve of the step portion The temperature at the intersection of the step with the extended line of the base line on the high temperature side was defined as the glass transition temperature.

[Melting point of release agent]
A differential scanning calorimeter “DSC210” (manufactured by Seiko Denshi Kogyo Co., Ltd.) was used to measure from 20 ° C. at a rate of temperature increase of 10 ° C./min, and the maximum peak temperature was taken as the melting point.

[Volume Median Particle Size (D ₅₀ ) and Particle Size Distribution of Resin Particles and Release Agent Particles]
The volume median particle size of the resin particles and release agent particles was measured as follows.
・ Measuring device: Laser diffraction particle size measuring instrument “LA-920” (manufactured by Horiba, Ltd.)
Measurement conditions: Distilled water was added to the measurement cell, and the volume-median particle size (D ₅₀ ) and the volume average particle size (D _v ) were measured at a concentration at which the absorbance was in an appropriate range.
Further, as the particle size distribution, the CV value (%) was calculated from the volume average particle size (D _v ) and standard deviation displayed by the particle size measuring instrument according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size (D _v )) × 100

[Solid content concentration of resin particle dispersion and release agent particle dispersion]
Using an infrared moisture meter “FD-230” (manufactured by Kett Scientific Laboratory), 5 g of a measurement sample is set at a drying temperature of 150 ° C. and in a measurement mode 96 (monitoring time 2.5 minutes / variation width 0.05%). The moisture percentage was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (% by mass) = 100-M
M: moisture (%) = [(W−W ₀ ) / W] × 100
W: Sample mass before drying (initial sample mass)
W ₀ : Sample weight after drying (absolute dry weight)

[Toner circularity]
-Preparation of dispersion: Toner dispersion was prepared by adding 50 mg of toner to 5 ml of a 5% by weight aqueous solution of polyoxyethylene lauryl ether “Emulgen 109P” (manufactured by Kao Corporation, HLB: 13.6). For 1 minute, 20 ml of distilled water was added, and the mixture was further dispersed for 1 minute with an ultrasonic disperser.
Measurement device: Flow type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation)
・ Measurement mode: HPF measurement mode

[BET specific surface area of toner (particles)]
Using “Micromeritics FlowSorb III” (manufactured by Shimadzu Corporation), the BET specific surface area was measured under the following conditions.
Toner sample amount: 0.09 to 0.11 g
・ Deaeration condition: 40 ° C., 10 minutes ・ Adsorption gas: Nitrogen gas

[Volume Median Particle Size (D ₅₀ ) and Particle Size Distribution of Aggregated Particles and Toner (Particles)]
The volume median particle size of the aggregated particles and toner was measured as follows.
・ Measuring machine: "Coulter Multisizer III" (Beckman Coulter, Inc.)
・ Aperture diameter: 50μm
・ Analysis software: “Multisizer III version 3.51” (manufactured by Beckman Coulter)
・ Electrolyte: “Isoton II” (Beckman Coulter, Inc.)
Dispersion: Polyoxyethylene lauryl ether “Emulgen 109P” (manufactured by Kao Corporation, HLB: 13.6) was dissolved in the electrolytic solution to obtain a dispersion having a concentration of 5% by mass.
-Dispersion condition: 10 mg of a toner measurement sample is added to 5 mL of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, and then 25 mL of electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. A sample dispersion was prepared.
Measurement conditions: The sample dispersion is 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 are measured and the particle size distribution thereof. From this, the volume median particle size (D ₅₀ ) was determined.
Further, as the particle size distribution, the CV value (%) was calculated from the volume average particle size (D _v ) and standard deviation displayed by the analysis software according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size (D _v )) × 100

[Evaluation of storage stability of toner at 45 ° C.]
20 g of toner was put in a wide-mouth polyethylene bottle having an internal volume of 100 ml, sealed, and allowed to stand for 48 hours in an environment at a temperature of 45 ° C. Thereafter, it was allowed to stand for 12 hours or more while being sealed at a temperature of 25 ° C. and cooled. Next, a 250 μm mesh sieve is set on a vibrating table of a powder characteristic evaluation device “Powder Tester” (manufactured by Hosokawa Micron Co., Ltd.). The toner mass was measured. The smaller the value, the better the heat resistant storage stability of the toner.

[Evaluation of storage stability of toner at 50 ° C.]
20 g of toner was placed in a 100 ml wide-mouth polyethylene bottle, sealed, and allowed to stand for 48 hours in an environment at a temperature of 50 ° C. Thereafter, it was allowed to stand for 12 hours or more while being sealed at a temperature of 25 ° C. and cooled. Next, a 250 μm mesh sieve is set on a vibrating table of a powder characteristic evaluation device “Powder Tester” (manufactured by Hosokawa Micron Co., Ltd.). The toner mass was measured. The smaller the value, the better the heat resistant storage stability of the toner.

[Initial charge amount of toner]
A solid image was printed on paper (A4 size) using a commercially available printer “ML5400” (Oki Data Corporation). The printer is stopped when half of the A4 paper is transferred, and a 1 cm × 2 cm jig is attached to each 3 cm portion from both ends of the developing roller, and the amount of charge is measured using a Q / m meter (Trek: 210HS). It was measured. The chargeability is negative and the higher the absolute value of the charge amount, the higher the chargeability.

[Charge amount of toner after printing 500 sheets]
Using the same printer and paper as the initial charge amount evaluation, after printing 500 images with a printing rate of 5% continuously, using the same method as the above initial charge amount measurement method, The amount of charge was measured. The chargeability is negative and the higher the absolute value of the charge amount, the higher the chargeability.

[Production of polyester]
Production Examples 1, 2, and 3
(Production of amorphous polyesters a, b, and c)
Raw material other than fumaric acid shown in Table 1, di (2-ethylhexanoic acid) tin and gallic acid, nitrogen introduction pipe, dehydration pipe equipped with fractionation pipe through which hot water of 98 ° C was passed, stirrer and thermocouple Was put into a 10-liter four-necked flask equipped with the above and heated to 180 ° C. in a nitrogen atmosphere. The temperature was raised from 180 ° C. to 210 ° C. at 10 ° C./hr, and then a condensation polymerization reaction was carried out at 210 ° C. for 7 hours. Then, fumaric acid and 4-tert-butylcatechol were added and reacted at 210 ° C. for 5 hours at normal pressure, and then reacted at 8.3 kPa until the softening point shown in Table 1 was reached. Quality polyesters a, b and c were obtained.
Table 1 shows the physical properties of the amorphous polyesters a, b, and c.

Production Example 4
(Production of amorphous polyester d)
The inside of a four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer, and thermocouple was replaced with nitrogen, and the raw material monomers and esterification catalyst excluding trimellitic anhydride shown in Table 1 were placed in a nitrogen atmosphere. While stirring, the temperature was raised to 230 ° C. and maintained at 230 ° C. for 6 hours, and then the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 215 ° C. and returning to atmospheric pressure, trimellitic anhydride was added and maintained at 215 ° C. for 1 hour, then the pressure in the flask was further lowered and maintained at 8.3 kPa for 3 hours. Amorphous polyester d was obtained.
Table 1 shows the physical properties of the amorphous polyester d.

Production Example 5
(Production of amorphous polyester e)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple is purged with nitrogen, and the raw material monomer and esterification catalyst excluding fumaric acid shown in Table 1 are added and stirred in a nitrogen atmosphere However, after raising the temperature to 230 ° C. and maintaining at 230 ° C. for 5 hours, the pressure in the flask was further lowered and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, fumaric acid and tert-butylcatechol were added and maintained at a temperature of 210 ° C. for 5 hours, and then the pressure in the flask was further lowered at 8.3 kPa. The polyester resin e was obtained by maintaining for 4 hours.
Table 1 shows the physical properties of the amorphous polyester e.

  In Table 1, the molar ratios shown in the “alcohol component” column and the “carboxylic acid component” column indicate the number of moles when all alcohol components are 100, respectively.

Production Example 6
(Production of basic aqueous solution 1)
100 g of potassium carbonate and 400 g of deionized water were placed in a 1 L beaker and stirred for 30 minutes with a magnetic stirrer to prepare a 20 mass% potassium carbonate aqueous solution having a pH of 12.4 at 25 ° C.

Production Example 7
(Production of basic aqueous solution 2)
100 g of potassium hydroxide and 400 g of deionized water were placed in a 1 L beaker and stirred for 30 minutes with a magnetic stirrer to prepare a 20 mass% potassium hydroxide aqueous solution. Next, at 25 ° C., while stirring this potassium hydroxide aqueous solution with a magnetic stirrer, a predetermined amount of phosphoric acid and deionized water were added while the electrode of the pH meter was immersed in the solution, and the pH was measured. The basic aqueous solution 2 containing 10% by mass of potassium hydroxide and having a pH of 10.0 at 25 ° C. was prepared until the pH at 25 ° C. reached 10.0.

Production Example 8
(Production of basic aqueous solution 3)
50 g of potassium hydroxide and 450 g of deionized water were placed in a 1 L beaker and stirred with a magnetic stirrer for 30 minutes to prepare a basic aqueous solution 3 having a pH of 14.0 at 25 ° C.

[Production of resin particles]
Production Example 9
(Production of resin particle dispersion Em-1)
In a 2 liter stainless steel kettle, amorphous polyester a (600 g), copper phthalocyanine pigment “ECB-301” (manufactured by Dainichi Seika Kogyo Co., Ltd.), anionic surfactant “Neopelex G-15” ( 40.0 g, 15 mass% sodium dodecylbenzenesulfonate aqueous solution, manufactured by Kao Corporation, nonionic surfactant “Emulgen 430” (manufactured by Kao Corporation, polyoxyethylene (26 mol) oleyl ether, HLB: 16.2 ) 6.0 g, basic aqueous solution 1 (68 g; equivalent to a neutralization degree of 100 mol%), and 150 g of deionized water were mixed, and the mixture was mixed up to 95 ° C. with stirring at 1.2 m / s with a Kai-type stirrer. Was heated. The mixture was kept at 95 ° C. for 2 hours under stirring at 1.2 m / s with a Kai-type stirrer to obtain a resin neutralized product.
Next, 1156 g of deionized water was added dropwise at 95 ° C. with stirring of 1.2 m / s with a Kai-type stirrer to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., passed through a 200 mesh (mesh: 105 μm) wire mesh, deionized water was added to adjust the solid content concentration to 30% by mass, and 1800 g was weighed. Then, while stirring at 25 ° C., 2.3 g of an aqueous oxazoline group-containing polymer aqueous solution “Epocross WS-700” (manufactured by Nippon Shokubai Co., Ltd., solid content 25% by mass, acrylic main chain, oxazoline number 220 (g solid / eq)) The number of moles of oxazoline groups to the number of moles of carboxy groups in the resin particles: 0.0156 equivalent) was added, and the temperature was raised to 95 ° C. and held at 95 ° C. for 1 hour. Next, after cooling to 25 ° C., the obtained emulsion was passed through a 200 mesh (mesh 105 μm) wire mesh, deionized water was added to adjust the solid content to 28% by mass, and the resin particle dispersion Em-1 was obtained.
The physical properties are shown in Table 2.

Production Examples 10-14
(Production of resin particle dispersions Em-2 to Em-6)
Resin particle dispersions Em-2 to Em-6 were produced in the same manner as in Production Example 9 except that the amount of the oxazoline group-containing polymer used in Production Example 9 was changed to that shown in Table 2.
The physical properties are shown in Table 2.

Production Example 15
(Production of resin particle dispersion Em-7)
In a 2-liter stainless steel kettle, 40.0 g of amorphous polyester b (600 g), an anionic surfactant “Neopelex G-15” (15% by weight sodium dodecylbenzenesulfonate aqueous solution, manufactured by Kao Corporation), Nonionic surfactant “Emulgen 430” (manufactured by Kao Corporation, polyoxyethylene (26 mol) oleyl ether, HLB: 16.2) 6.0 g, basic aqueous solution 1 (64 g; equivalent to a neutralization degree of 100 mol%) , And 160 g of deionized water, and the mixture was heated to 95 ° C. with stirring at 1.2 m / s with a chi-type stirrer. The mixture was kept at 95 ° C. for 2 hours under stirring at 1.2 m / s with a Kai-type stirrer to obtain a resin neutralized product.
Next, 1955 g of deionized water was added dropwise at 95 ° C. with stirring of 1.2 / s with a Kai-type stirrer to obtain an emulsion. Next, the obtained emulsion is cooled to 25 ° C., passed through a 200 mesh (mesh: 105 μm) wire mesh, deionized water is added, and the solid content concentration is adjusted to 28% by mass to obtain a resin particle dispersion. Em-7 was obtained.
The physical properties are shown in Table 2.

Production 16
(Production of resin particle dispersion Em-8)
In a 2 liter stainless steel kettle, amorphous polyester c (600 g), anionic surfactant “Neopelex G-15” (manufactured by Kao Corporation, 15% by weight sodium dodecylbenzenesulfonate aqueous solution) 40.0 g, Nonionic surfactant “Emulgen 430” (manufactured by Kao Corporation, polyoxyethylene (26 mol) oleyl ether, HLB: 16.2) 6.0 g, basic aqueous solution 1 (81 g; equivalent to a neutralization degree of 100 mol%) , And 160 g of deionized water, and the mixture was heated to 95 ° C. with stirring at 1.2 m / s with a chi-type stirrer. The mixture was kept at 95 ° C. for 2 hours under stirring at 1.2 m / s with a Kai-type stirrer to obtain a resin neutralized product.
Next, 1156 g of deionized water was added dropwise at 95 ° C. with stirring of 1.2 / s with a Kai-type stirrer to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., passed through a 200 mesh (mesh: 105 μm) wire mesh, deionized water was added to adjust the solid content concentration to 30% by mass, and 1800 g was weighed. Then, while stirring at 25 ° C., 9.4 g of oxazoline group-containing polymer aqueous solution “Epocross WS-700” (manufactured by Nippon Shokubai Co., Ltd., solid content 25 mass%, acrylic main chain, oxazoline number 220 (g solid / eq)) The number of moles of oxazoline groups relative to the number of moles of carboxy groups in the resin particles: 0.0625 equivalent) was added, and then the temperature was raised to 95 ° C. and held at 95 ° C. for 1 hour. Next, after cooling to 25 ° C., the obtained emulsion was passed through a 200 mesh (mesh 105 μm) wire mesh, deionized water was added to adjust the solid content to 28% by mass, and the resin particle dispersion Em-8 was obtained.
The physical properties are shown in Table 2.

Production Example 17
(Production of resin particle dispersion Em-9)
In a 2 liter stainless steel kettle, 40.0 g of amorphous polyester d (600 g), anionic surfactant “Neopelex G-15” (15% by weight sodium dodecylbenzenesulfonate aqueous solution, manufactured by Kao Corporation), Nonionic surfactant “Emulgen 430” (manufactured by Kao Corporation, polyoxyethylene (26 mol) oleyl ether, HLB: 16.2) 6.0 g, basic aqueous solution 2 (92 g; equivalent to a neutralization degree of 100 mol%) And 132 g of deionized water were mixed, and the mixture was heated to 95 ° C. with stirring at 1.2 m / s with a chi-type stirrer. The mixture was kept at 95 ° C. for 2 hours under stirring at 1.2 m / s with a Kai-type stirrer to obtain a resin neutralized product.
Then, 1160 g of deionized water was added dropwise at 95 ° C. with stirring of 1.2 / s with a Kai-type stirrer to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., passed through a 200 mesh (mesh: 105 μm) wire mesh, deionized water was added to adjust the solid content concentration to 30% by mass, and 1800 g was weighed. Then, while stirring at 25 ° C., 9.4 g of oxazoline group-containing polymer aqueous solution “Epocross WS-700” (manufactured by Nippon Shokubai Co., Ltd., solid content 25 mass%, acrylic main chain, oxazoline number 220 (g solid / eq)) The number of moles of oxazoline groups relative to the number of moles of carboxy groups in the resin particles: 0.0625 equivalent) was added, and then the temperature was raised to 95 ° C. and held at 95 ° C. for 1 hour. Next, after cooling to 25 ° C., the obtained emulsion was passed through a 200 mesh (mesh 105 μm) wire mesh, deionized water was added to adjust the solid content to 28% by mass, and the resin particle dispersion Em-9 was obtained.
The physical properties are shown in Table 2.

Production Example 18
(Production of resin particle dispersion Em-10)
In a 2 liter stainless steel kettle, 40.0 g of amorphous polyester e (600 g), anionic surfactant “Neopelex G-15” (15% by weight sodium dodecylbenzenesulfonate aqueous solution, manufactured by Kao Corporation), Nonionic surfactant “Emulgen 430” (manufactured by Kao Corporation, polyoxyethylene (26 mol) oleyl ether, HLB: 16.2) 6.0 g, basic aqueous solution 3 (92 g; neutralization degree equivalent to 100 mol%) And 132 g of deionized water were mixed, and the mixture was heated to 95 ° C. with stirring at 1.2 m / s with a chi-type stirrer. The mixture was kept at 95 ° C. for 2 hours under stirring at 1.2 m / s with a Kai-type stirrer to obtain a resin neutralized product.
Then, 1160 g of deionized water was added dropwise at 95 ° C. with stirring of 1.2 / s with a Kai-type stirrer to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., passed through a 200 mesh (mesh: 105 μm) wire mesh, deionized water was added, the solid content concentration was adjusted to 28% by mass, and resin particle dispersion was performed. A liquid Em-10 was obtained.
The physical properties are shown in Table 2.

[Manufacture of release agent particles]
Production Example 19
(Production of release agent particle dispersion W-1)
In a 1 liter beaker, 3.8 g of a sodium acrylate-sodium maleate copolymer aqueous solution “Poise 521” (manufactured by Kao Corporation, effective concentration 40% by mass) is dissolved in 200 g of deionized water as a sodium polycarboxylate aqueous solution. After that, 5 g of carnauba wax “Carnauba Wax No. 1” (manufactured by Kato Hiroyuki, melting point 83 ° C.) and paraffin wax “HNP-9” (manufactured by Nippon Seiki Co., Ltd., melting point 75 ° C.) 45 g were added, While maintaining the temperature at 90 to 95 ° C., the mixture was melted and stirred to obtain a molten mixture in which carnauba wax and paraffin wax were fused together.
The aqueous solution containing the obtained molten mixture was further subjected to a dispersion treatment for 30 minutes with an ultrasonic homogenizer “US-600T” (manufactured by Nippon Seiki Co., Ltd.) while maintaining the temperature at 90 to 95 ° C., and then cooled to room temperature. Deionized water was added thereto to adjust the release agent solid content to 20% by mass to obtain a release agent particle dispersion. The volume median particle size (D ₅₀ ) of the release agent particles in the release agent particle dispersion was 450 nm, and the CV value was 30%.

[Production of toner]
Example 1
(Preparation of cyan toner A)
Into a 2 liter four-necked flask equipped with a dehydrating tube, a stirrer and a thermocouple, resin particle dispersion Em-3 (200 g), deionized water 32 g, and release agent particle dispersion W-1 (20 g) ) At a temperature of 25 ° C. Next, while stirring the mixture, an aqueous solution in which 15 g of ammonium sulfate was dissolved in 195 g of deionized water was added dropwise at 25 ° C. over 10 minutes, and then the temperature was raised to 45 ° C. so that the volume median particle size of the aggregated particles was 5 The mixture was held at 45 ° C. until 1 μm was obtained to obtain an agglomerated particle dispersion (1).
While increasing the temperature of the aggregated particle (1) dispersion from 45 ° C. to 50 ° C. over 5 hours, the dispersion obtained by mixing the resin particle dispersion Em-7 (97 g) and 19 g of deionized water was reduced to 0 per minute. The solution was added dropwise at a rate of 4 ml to obtain an agglomerated particle dispersion (2).
An aqueous solution in which 13 g of an anionic surfactant “Emar E27C” (manufactured by Kao Corporation, sodium polyoxyethylene lauryl ether sulfate, effective concentration 27 mass%) and 511 g of deionized water were added to the aggregated particle dispersion (2). Thereafter, the temperature was raised to 65 ° C. over 1.5 hours and held at 65 ° C. for 1 hour to fuse the aggregated particles to obtain core-shell particles.
The obtained core-shell particle dispersion was cooled to 25 ° C., the solid content of the dispersion was separated by suction filtration, washed with deionized water, and dried at 28 ° C. to obtain toner particles. 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 “Cabo Seal TS720” (manufactured by Cabot, number average particles) 1.0 part by mass (diameter: 0.012 μm) was placed in a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain cyan toner A.
Table 3 shows the physical properties and evaluation of cyan toner A.

Examples 2, 3, 4, and 5
(Production of cyan toners B, C, D, and E)
Cyan toners B, C, D, and E were obtained in the same manner as in Example 1 except that the resin particle dispersion in Example 1 was changed to the resin particle dispersion described in Table 3 or Table 4.
The physical properties and evaluation of the toner are shown in Table 3 or Table 4.

Comparative Examples 1, 2, and 3
(Production of cyan toners F, G, and H)
In Example 1, cyan toners F, G, and H were obtained in the same manner as in Example 1 except that the resin particle dispersion was changed to the resin particle dispersion shown in Table 4.
Table 4 shows the physical properties and evaluation of the toner.

  In Tables 3 to 4, “after resin particle formation” shown in the “addition time” column of the oxazoline polymer means that the oxazoline polymer is a resin particle dispersion Em-1 to Em-6, Em-8 or Em-9. It represents adding after phase inversion emulsification in preparation (after resin particle formation).

  As can be seen from Tables 3 to 4, the toners of the examples hardly aggregated after being stored at 45 ° C. and 50 ° C., and maintained a high charge amount not only at the initial stage but also after printing 500 sheets. The toner of the comparative example easily aggregated after being stored at 45 ° C. and 50 ° C. In the comparative example, the initial charge amount was small, and the charge amount further decreased after printing 500 sheets.

Claims (5)

Step (1): Step of emulsifying a resin containing at least a polyester (a) having an acid group to obtain resin particles (A),
Step (2): a step of aggregating the resin particles (A) in an aqueous medium to obtain agglomerated particles (I);
Step (3): The resin particles (C) containing at least an acid group and containing an amorphous polyester (c) having a glass transition temperature of 55 ° C. or higher are aggregated on the surface of the aggregated particles (I). Obtaining aggregated particles (II), and
Step (4): The aggregated particles (II) are fused within the range of the glass transition temperature of the amorphous polyester (c) from −5 ° C. to the glass transition temperature + 10 ° C. And obtaining a core-shell particle, a method for producing an electrophotographic core-shell toner comprising:
Before the step (3), the polymer compound containing at least two oxazoline groups has a molar number of oxazoline groups of the polymer compound of 0.02 equivalents or more relative to the number of acid groups in the polyester (a). Having a step of adding in a range of 0.45 equivalent or less,
A method for producing an electrophotographic toner, wherein a difference in solubility parameter (SP value) between the polyester (a) and the amorphous polyester (c) by a Fedors method is 0.6 or more and less than 1.8.   The method for producing an electrophotographic toner according to claim 1, wherein the polyester (a) is obtained by condensation polymerization of a carboxylic acid component containing at least one of alkenyl succinic acid and an acid anhydride thereof and an alcohol component.   The method for producing an electrophotographic toner according to claim 1 or 2, wherein the polyester (a) has a glass transition temperature of less than 50C.   The electrophotographic image according to any one of claims 1 to 3, wherein the amorphous polyester (c) is obtained by condensation polymerization of a carboxylic acid component containing at least one of terephthalic acid and acid anhydride thereof and an alcohol component. Of manufacturing toner.   The manufacturing method of the toner for electrophotography in any one of Claims 1-4 in which the said high molecular compound has a structural unit derived from (meth) acrylic acid and (meth) acrylic acid ester.