JP6632066B2 - Method for producing toner for developing electrostatic images - Google Patents

Description

  The present invention relates to a method for producing a toner for developing an electrostatic image.

  In the field of electrophotography, with the development of electrophotographic systems, there has been a demand for the development of a toner for developing an electrostatic image capable of achieving high image quality and high speed. On the other hand, in recent years, it has been proposed that the toner has a core-shell structure having a core portion and a shell portion covering the core portion.

For example, Patent Document 1 is a recycled polyester resin, and when used in an electrostatic image developing toner, is excellent in initial image quality, low-temperature fixability, image quality under high temperature and high humidity, and chargeability under high temperature and high humidity. A polyester resin for an electrostatic image developing toner. Here, it is a regenerated polyester resin having an alkylene terephthalate structure as a constituent unit, which contains a depolymerization catalyst and is insoluble in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) at 25 ° C. The content of the polyester resin is from 1 to 30% by weight.
U.S. Pat. No. 6,037,086 discloses a sustainable toner resin, a polyester comprising a bio-based polyacid or polyester reagent, and a polyol comprising a depolymerized recycled plastic (including oligomeric polyethylene terephthalate (PET)). The present invention relates to a toner resin containing an optional wax and an optional colorant.

JP 2009-192856 A JP 2014-98149 A

It is described that the toner for developing an electrostatic image described in Patent Documents 1 and 2 exhibits good low-temperature fixability. However, a toner having a good low-temperature fixability is such that when stored in a high-temperature and high-humidity environment, toner particles are fused together, and a problem is likely to occur from the viewpoint of heat-resistant storage stability. The toner was fused or adhered to the developing roll of the photographic system, causing streaks, and problems were likely to occur from the viewpoint of durability.
An object of the present invention is to provide a method for producing a toner for developing an electrostatic image, which is excellent in low-temperature fixability, heat-resistant storage stability and durability.

  The present inventors have proposed a toner for developing an electrostatic image containing core-shell particles, in which the mixing ratio of polyethylene terephthalate used in the step of obtaining the resin for core (a) and the resin for shell (b) satisfies a predetermined relationship. Thus, it was found that a toner for developing an electrostatic charge image having excellent low-temperature fixability, heat-resistant storage stability and durability can be obtained.

The present invention relates to a method for producing a toner including the following steps 1 to 5, wherein the difference [BA] between the following A and the following B is 20 mol% or more.
Step 1: a step of obtaining a resin for core (a) through a reaction between an alcohol component, a carboxylic acid component, and optionally polyethylene terephthalate.
Step 2: a step of reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate to obtain a shell resin (b).
Step 3: a step of obtaining aggregated particles (I) from the aqueous dispersion containing the core resin (a) and the release agent.
Step 4: a step of adding the shell resin (b) to the aggregated particles (I) obtained in Step 3 to obtain a dispersion of the aggregated particles (II).
Step 5: a step of fusing the aggregated particles (II) obtained in Step 4 to obtain core-shell particles.
A: A (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the mole number of the alcohol component in step 1 and the mole number of ethylene glycol units in polyethylene terephthalate. Amount.
B: B (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the number of moles of the alcohol component in step 2 and the number of moles of ethylene glycol units in polyethylene terephthalate. Amount.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrostatic image developing toner which is excellent in low-temperature fixability, heat-resistant storage stability, and durability can be provided.

[Production method of toner for developing electrostatic image]
The method for producing a toner for developing an electrostatic image of the present invention includes the following steps 1 to 5, wherein the difference [BA] of the following A with respect to the following B is 20 mol% or more.
Step 1: a step of obtaining a resin for core (a) through a reaction between an alcohol component, a carboxylic acid component, and optionally polyethylene terephthalate.
Step 2: a step of reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate to obtain a shell resin (b).
Step 3: a step of obtaining aggregated particles (I) from the aqueous dispersion containing the core resin (a) and the release agent.
Step 4: a step of adding the shell resin (b) to the aggregated particles (I) obtained in Step 3 to obtain a dispersion of the aggregated particles (II).
Step 5: a step of fusing the aggregated particles (II) obtained in Step 4 to obtain core-shell particles.
A: A (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the mole number of the alcohol component in step 1 and the mole number of ethylene glycol units in polyethylene terephthalate. Amount.
B: B (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the number of moles of the alcohol component in step 2 and the number of moles of ethylene glycol units in polyethylene terephthalate. Amount.

The reason why the toner for developing an electrostatic image obtained by the production method of the present invention is excellent in durability, low-temperature fixability and heat-resistant storage stability is not clear, but is considered as follows.
The electrostatic image developing toner obtained by the production method of the present invention has a core-shell type structure, and the shell resin (b) is obtained by reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate. The difference [BA] of A is as large as 20 mol% or more. Thereby, the compatibility between the resin for shell (b) and the resin for core (a) is appropriately reduced, and the core portion and the shell portion are favorably adhered to each other and excessively compatible with each other is suppressed. It is considered that a core-shell structure is formed, and the resin (b) of the shell portion and the resin (a) of the core portion can sufficiently exhibit the respective functions described below.
Since the resin for shell (b) uses polyethylene terephthalate, which is a polymer resin, as a raw material, it is considered that low molecular weight components such as monomers and oligomers can be reduced, and durability is considered to be good. In addition, the core resin (a) has a lower or no polyethylene terephthalate content than the shell resin (b), and thus has high hydrophobicity. As a result, it is considered that the dispersibility of the release agent is improved, the release agent is easily melted at a low temperature, and the low-temperature fixability is considered to be good. In addition, since the shell portion contains a large amount of polyethylene terephthalate, the hydrophobicity is reduced, the affinity with the release agent is reduced, and the release agent is considered to be less exposed to the surface than the core portion. It is considered that the heat-resistant storage stability is good while satisfying the fixability.

Difference [BA]
The difference [BA] in the production method of the present invention is 20 mol% or more, more preferably 25 mol% or more, and still more preferably 27 mol% from the viewpoint of obtaining excellent low-temperature fixability, heat-resistant storage stability and durability. Mol% or more, more preferably 30 mol% or more. The difference [BA] is preferably 95 mol% or less, more preferably 80 mol% or less, still more preferably 60 mol% or less, further preferably from the viewpoint of obtaining excellent low-temperature fixability, heat-resistant storage stability and durability. Is 50 mol% or less.

  A (mol%) is polyethylene in terms of the ratio of the mole number a2 of ethylene glycol units derived from polyethylene terephthalate to the sum of the mole number a1 of the alcohol component in step 1 and the mole number a2 of ethylene glycol units in polyethylene terephthalate. The amount is terephthalate.

Note that A is obtained by the following equation (a-1).

Here, a2 is obtained by the following equation (a-2).

  A (mol%) is preferably 80 mol% or less, more preferably 75 mol% or less, still more preferably 60 mol% or less, further preferably from the viewpoint of obtaining excellent low-temperature fixability, heat-resistant storage stability and durability. 50 mol% or less, more preferably 40 mol% or less, more preferably 30 mol% or less, further preferably 25 mol% or less, further preferably 20 mol% or less, further preferably 10 mol% or less, and still more preferably 5 mol% or less. % Or less, and 0 mol% or more, and more preferably 0 mol%.

  B (mol%) is polyethylene in terms of the ratio of the number of moles b2 of ethylene glycol units derived from polyethylene terephthalate to the sum of the number of moles b1 of alcohol component in step 2 and the number of moles b2 of ethylene glycol units in polyethylene terephthalate. The amount is terephthalate.

Note that B is obtained by the following equation (b-1).

Note that b2 is obtained by the following equation (b-2).

  B (mol%) is preferably 20 mol% or more, more preferably 25 mol% or more, more preferably 27 mol% or more, further preferably from the viewpoint of obtaining excellent low-temperature fixability, heat-resistant storage stability and durability. 30 mol% or more, and from the same viewpoint, preferably 95 mol% or less, more preferably 80 mol% or less, still more preferably 70 mol% or less, still more preferably 60 mol% or less, and still more preferably 50 mol% or less. % Or less.

<Step 1>
Step 1 involves reacting the alcohol component (a-al), the carboxylic acid component (a-ac), and optionally polyethylene terephthalate (a-pet) from the viewpoint of improving the low-temperature fixability and durability of the toner. Through the process, a core resin (a) is obtained.
Step 1 includes at least the following step 1a, and may further include step 1b.
Step 1a: a step of reacting an alcohol component (a-al), a carboxylic acid component (a-ac), and optionally polyethylene terephthalate (a-pet) Step 1b: a raw material vinyl monomer of a vinyl resin segment (A2) And optionally a step of performing an addition polymerization reaction with a bi-reactive monomer. In step 1, a polyester is obtained in step 1a, and a composite resin having a polyester resin segment (A1) and a vinyl resin segment (A2) in steps 1a and 1b. (A _h ) can be obtained.
When the method includes the step 1b, the step 1b may be performed after the step 1a, the step 1a may be performed after the step 1b, or the step 1a and the step 1b may be performed in parallel.
Here, "arbitrarily" means that it may or may not be included.

{Step 1a}
[Alcohol component (a-al)]
Examples of the alcohol component (a-al) include diols, polyhydric alcohols having a valency of 3 or more, and diols are preferable.
Examples of the diol include an aliphatic diol having 2 to 12 carbon atoms, an aromatic diol, and an alicyclic diol.

The aliphatic diol is preferably an aliphatic diol having 3 to 6 carbon atoms having a hydroxy group bonded to a secondary carbon atom.
Examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, and 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol and the like.
Examples of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom and having 3 to 6 carbon atoms include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-propanediol. Butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, 3,3-dimethyl Examples thereof include -1,2-butanediol and the like, preferably at least one kind selected from 1,2-propanediol and 2,3-butanediol, and more preferably 1,2-propanediol.

Examples of the aromatic diol include an alkylene oxide adduct of bisphenol A.
The alkylene oxide adduct of bisphenol A is preferably a compound represented by the following general formula (I).

In the general formula (I), OR ¹ and R ² O are both oxyalkylene groups, preferably each independently an oxyalkylene group having 1 to 4 carbon atoms, and more preferably an oxyethylene group. Or an oxypropylene group, and more preferably an oxypropylene group.
x and y correspond to the number of moles of the alkylene oxide added. Further, from the viewpoint of reactivity with the carboxylic acid component, the average value of the sum of x and y is preferably 2 or more. From the same viewpoint, the average value of the sum of x and y is preferably 7 or less, more preferably 5 or less, and still more preferably 3 or less.
In addition, x OR ¹ and y R ² O may be the same or different, but are preferably the same from the viewpoint of improving the fixability of the toner to the recording medium. The alkylene oxide adduct of bisphenol A may be used alone or in combination of two or more. The alkylene oxide adduct of bisphenol A is preferably a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A, and more preferably a propylene oxide adduct of bisphenol A.

  Examples of the alicyclic diol include cyclohexanediol and hydrogenated bisphenol A.

As the alcohol component (a-al), among these, preferably, an alkylene oxide adduct of bisphenol A, hydrogenated bisphenol A, and a C3 to C6 compound having a hydroxy group bonded to a secondary carbon atom. It is at least one selected from aliphatic diols, more preferably an alkylene oxide adduct of bisphenol A, and even more preferably a propylene oxide adduct of bisphenol A.
The alcohol component (a-al) can be used alone or in combination of two or more.

  The blending amount of the alkylene oxide adduct of bisphenol A is preferably at least 30 mol%, more preferably at least 50 mol%, based on the total amount of the alcohol component (a-al) and polyethylene glycol derived from polyethylene terephthalate in step 1. , More preferably at least 65 mol%, further preferably at least 80 mol%, still more preferably at least 90 mol%, and preferably at most 100 mol%.

[Carboxylic acid component (a-ac)]
Examples of the carboxylic acid component include dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and their acid anhydrides and their alkyl esters having 1 to 3 carbon atoms. More preferably, it consists of a dicarboxylic acid. The carboxylic acid component (a-ac) includes not only a free acid but also an anhydride that is decomposed during the reaction to generate an acid, or an alkyl ester of each carboxylic acid having 1 to 3 carbon atoms.
Dicarboxylic acids include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid and terephthalic acid, and terephthalic acid is preferred.
Examples of the aliphatic dicarboxylic acid include fumaric acid, adipic acid, sebacic acid, maleic acid, azelaic acid, succinic acid, and succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. Or anhydrides thereof (hereinafter also referred to as “alkenyl succinic acid”) and the like.

(Alkenyl succinic acid)
The carbon number of the alkenyl group in the alkenyl succinic acid is preferably 9 or more, and more preferably 18 or less, from the viewpoint of obtaining a toner for developing an electrostatic image having excellent low-temperature fixability, heat-resistant storage stability and durability. It is preferably 16 or less, more preferably 14 or less. Further, these alkenyl groups may be linear or branched. However, from the viewpoint of obtaining a toner for developing an electrostatic image having excellent low-temperature fixing property, heat-resistant storage stability and durability, the alkenyl group may be a branched chain. Preferably, there is.

  The alkenyl succinic acid preferably has 9 to 18 carbon atoms, more preferably 9 to 16 carbon atoms, and still more preferably 9 to 16 carbon atoms, from the viewpoint of obtaining an electrostatic image developing toner having excellent low-temperature fixability, heat-resistant storage stability and durability. Is preferably a mixture containing two or more of alkenyl succinic acids having 9 to 14 branched alkenyl groups. By using alkenyl succinic acid having a branched alkenyl group having a different number of carbon atoms in combination, the resulting resin has a broad endothermic peak near the glass transition point in differential scanning calorimetry (DSC), and a binder resin for toner. Has a very wide fixing temperature range.

From the viewpoint of obtaining a toner for developing electrostatic images excellent in low-temperature fixing property, heat-resistant storage stability and durability, alkenyl succinic acid is compounded with a compound having an alkylene group (alkylene compound), maleic acid, fumaric acid and their acid anhydrides. It is preferably obtained by a reaction with at least one selected from products. Among these acids, maleic anhydride is preferred from the viewpoint of reactivity.
As the alkylene compound, specifically, those obtained from ethylene, propylene, isobutylene, normal butylene and the like, for example, trimers and tetramers thereof are preferably used. Among these, propylene tetramer is preferred. From the viewpoint that the resin (a) has a very wide fixing temperature range, the alkylene compound has 9 to 18 (preferably 9 to 14) carbon atoms under gas chromatography mass spectrometry under the measurement conditions shown in the examples. It preferably has two or more peaks corresponding to the alkylene compound, more preferably four or more peaks, and even more preferably six or more peaks.

  The alkenyl succinic acid can be obtained by any production method. For example, by mixing an alkylene compound with at least one selected from maleic acid, fumaric acid and their acid anhydrides, and heating the mixture, It can be obtained by utilizing the reaction (see JP-A-48-23405, JP-A-48-23404, U.S. Pat. No. 3,374,285, etc.).

  From the viewpoint of obtaining a toner for developing an electrostatic image having excellent low-temperature fixability, heat-resistant storage stability and durability, the amount of the alkenyl succinic acid is the total of the carboxylic acid component in the resin (a) and terephthalic acid derived from polyethylene terephthalate. The amount is preferably at least 3 mol%, more preferably at least 5 mol%, further preferably at least 10 mol%, further preferably at least 15 mol%, further preferably at least 20 mol%, based on the amount. From the viewpoint of properties, the content is preferably 50 mol% or less, more preferably 45 mol% or less, still more preferably 40 mol% or less, and still more preferably 35 mol% or less.

Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid. Examples of the trivalent or higher polycarboxylic acid include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, and anhydrides thereof.
From the viewpoint of obtaining a toner for developing an electrostatic charge image having excellent low-temperature fixability, heat-resistant storage stability and durability, the compounding amount of the trivalent or higher polycarboxylic acid is derived from the carboxylic acid component in the resin (a) and polyethylene terephthalate. Is preferably at least 1 mol%, more preferably at least 3 mol%, even more preferably at least 4 mol%, and preferably at most 20 mol%, from the viewpoint of heat-resistant storage stability, based on the total amount of terephthalic acid. , More preferably at most 15 mol%, further preferably at most 10 mol%, further preferably at most 8 mol%.

The carboxylic acid component is preferably at least one selected from isophthalic acid, terephthalic acid, fumaric acid, adipic acid, sebacic acid, and alkenyl succinic acid, more preferably terephthalic acid, fumaric acid, adipic acid, And alkenylsuccinic acid.
The carboxylic acid component can be used alone or in combination of two or more.

[Polyethylene terephthalate (a-pet)]
In the present invention, in step 1, polyethylene terephthalate (a-pet) may be blended. In step 1, polyethylene terephthalate in which a polyol component and an acid component are polycondensed in advance is reacted with other alcohol components and acid components to be taken into the structure of the core resin (a).
As the polyethylene terephthalate, a polyethylene terephthalate produced by polycondensation of ethylene glycol with terephthalic acid, dimethyl terephthalate, or the like according to a conventional method can be used.

The intrinsic viscosity (hereinafter also referred to as “IV value”) of polyethylene terephthalate is preferably at least 0.40, more preferably at least 0.40, from the viewpoint of obtaining a toner for developing an electrostatic image having excellent low-temperature fixability, heat-resistant storage stability and durability. 0.50 or more, more preferably 0.55 or more, and preferably 1.0 or less, more preferably 0.90 or less, further preferably 0.80 or less, still more preferably 0.75 or less, and still more preferably Is 0.70 or less. The IV value is an index of the molecular weight. The IV value of polyethylene terephthalate can be adjusted by the polycondensation time and the like.
The IV value is measured, for example, by dissolving a sample in a phenol / tetrachloroethane = 60/40 (mass ratio) mixed solvent at a concentration of 0.4 g / dL, measuring with an Ubbelohde viscometer, and using the following formula. Can be calculated according to
[Where k is the Huggins constant, C is the concentration of the sample solution (g / dL), η = (t ₁ / t ₀ ) −1, and t ₀ is the number of seconds over which only the solvent falls. And t ₁ is the number of seconds during which the sample solution falls. k was set to 0.33. ]

Commercial products of polyethylene terephthalate include “RAMAPET L1” (manufactured by Indorama Ventures, IV value: 0.60), “RAMAPET N2G” (manufactured by Indorama Ventures, IV value: 0.75), and “TRN-NTJ” (manufactured by Teijin Limited) , IV value: 0.53), and “TRN-RTJC” (manufactured by Teijin Limited, IV value: 0.64).
In addition, the suitable compounding quantity of polyethylene terephthalate is as above-mentioned A.

  In step 1, the equivalent ratio (COOH group / OH group) of the carboxy group (COOH group) of the carboxylic acid component to the hydroxy group (OH group) of the alcohol component in the polyester resin is preferably 0.65 or more, more preferably 0.80 or more, and preferably 1.2 or less, more preferably 1.1 or less.

[Reaction conditions of step 1a]
In the reaction of step 1a, for example, an alcohol component (a-al), a carboxylic acid component (a-ac), and optionally polyethylene terephthalate (a-pet) are esterified in an inert gas atmosphere, if necessary. The polycondensation can be performed at a temperature of 120 ° C. or more and 250 ° C. or less using a catalyst, a co-catalyst, and a polymerization inhibitor.
As the esterification catalyst, an esterification catalyst such as a tin compound such as dibutyltin oxide or tin di (2-ethylhexanoate) or a titanium compound such as titanium diisopropylate bistriethanolaminate can be used.
The amount of the esterification catalyst is not limited, but is preferably at least 0.01 part by mass, more preferably at least 0.1 part by mass, based on 100 parts by mass of the carboxylic acid component and the alcohol component. , Preferably 1.5 parts by mass or less, more preferably 1.0 part by mass or less.

Examples of the cocatalyst include a pyrogallol compound. The pyrogallol compound has a benzene ring in which three adjacent hydrogen atoms are substituted with a hydroxyl group, and includes pyrogallol, gallic acid, gallic acid ester, 2,3,4-trihydroxybenzophenone, 2,2 ′, Examples thereof include benzophenone derivatives such as 3,4-tetrahydroxybenzophenone, and catechin derivatives such as epigallocatechin and epigallocatechin gallate. Gallic acid is preferred from the viewpoint of reactivity.
The amount of the cocatalyst used in the polycondensation reaction is preferably 0.001 parts by mass or more, based on 100 parts by mass of the alcohol component and the carboxylic acid component used in the polycondensation reaction, from the viewpoint of reactivity. It is preferably at least 0.005 parts by mass, more preferably at least 0.01 parts by mass, and preferably at most 1 part by mass, more preferably at most 0.4 parts by mass, even more preferably at most 0.2 parts by mass. is there.
The mass ratio of the co-catalyst to the esterification catalyst (promoter / esterification catalyst) is preferably 0.01 or more, more preferably 0.03 or more, and still more preferably 0.05 or more from the viewpoint of reactivity. And preferably 0.5 or less, more preferably 0.3 or less, and still more preferably 0.15 or less.

  Further, a radical polymerization inhibitor can be used as needed. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol. The amount of the radical polymerization inhibitor used is preferably at least 0.01 part by mass, more preferably at least 0.05 part by mass, and preferably at least 0.05 part by mass, based on 100 parts by mass of the total of the alcohol component and the carboxylic acid component. It is at most 0.5 part by mass, more preferably at most 0.1 part by mass.

{Step 1b}
By the step 1b, a composite resin (a _h ) having the polyester resin segment (A1) and the vinyl resin segment (A2) is obtained.
The composite resin (a _h ) is a polyester resin segment (A1), a vinyl resin segment (A2), and a bi-reactive monomer capable of reacting with any of the polyester resin segment (A1) and the vinyl resin segment (A2). It is preferable that it is composed of three constituent parts, namely, constituent parts derived therefrom. Further, components other than these three components may be included within a range not to impair the object of the present invention, but it is preferable that components other than the three components are not included.

The mass ratio [(A1) / (A2)] between the polyester resin segment (A1) and the vinyl resin segment (A2) in the composite resin (a _h ) is preferably 40/60 or more, more preferably 50/50. Above, more preferably 60/40 or more, and preferably 95/5 or less, more preferably 90/10 or less, more preferably 80/20 or less.
In the calculation of the mass ratio, the mass of the polyester resin segment (A1) is a value obtained by removing the dehydration amount during the condensation reaction from the total amount of the raw material monomers of the polyester resin segment (A1). The mass of the resin segment (A2) uses the total amount of the raw material monomer and the polymerization initiator of the vinyl-based resin segment (A2). The bireactive monomer used as needed is calculated as the mass of the polyester resin segment (A1).
In the composite resin (a _h ), the total content of the polyester resin segment (A1), the vinyl-based resin segment (A2), and the constituent unit derived from the amphoteric monomer is preferably 90 mol% or more, more preferably It is at least 95 mol%, more preferably at least 99 mol%, more preferably 100 mol%.

[Polyester resin segment (A1)]
The polyester resin constituting the polyester resin segment (A1) is not particularly limited as long as it is a polyester resin for toner having physical properties and the like generally used for toner. Those obtained by polycondensation of polyethylene terephthalate and made of the polyester resins exemplified as the above polyester resins are preferably used.

[Vinyl resin segment (A2)]
The vinyl-based resin segment (A2) contains a constituent unit derived from a vinyl monomer, preferably contains a constituent unit derived from a styrene compound, and more preferably has a constituent unit derived from a styrene compound and an alkyl group having 6 to 22 carbon atoms. And a structural unit derived from a vinyl monomer. That is, the raw material vinyl monomer of the vinyl resin segment (A2) preferably contains a styrene compound, and more preferably contains a styrene compound and a vinyl monomer having an alkyl group having 6 to 22 carbon atoms. .
Examples of the styrene compound include styrene and α-methylstyrene.
The carbon number of the alkyl group of the vinyl monomer having an alkyl group having 6 to 22 carbon atoms is preferably 6 or more, more preferably 8 or more, and is preferably 22 or less, more preferably 16 or less, and more preferably. Is 10 or less.
Among these, the vinyl monomer having an alkyl group having 6 to 22 carbon atoms is preferably 2-ethylhexyl (meth) acrylate.

As a raw material vinyl monomer of the vinyl resin segment (A2), a vinyl monomer other than the above monomers can be used in combination.
Other vinyl monomers include ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; Esters of ethylenic monocarboxylic acids such as dimethylaminoethyl acrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone.

The content of the styrene compound in the raw monomer of the vinyl-based resin segment (A2) is preferably 30% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, and preferably 99% by mass or more. It is at most 90 mass%, more preferably at most 90 mass%, more preferably at most 85 mass%.
The content of the vinyl monomer having an alkyl group having 6 to 22 carbon atoms in the raw monomer of the vinyl resin segment (A2) is preferably 1% by mass or more, more preferably 5% by mass or more, more preferably It is at least 10% by mass, more preferably at least 15% by mass, and preferably at most 70% by mass, more preferably at most 60% by mass, more preferably at most 50% by mass, more preferably at most 30% by mass.

  The total content of the vinyl monomer having an alkyl group having 6 to 22 carbon atoms and the styrene compound in the raw material monomer of the vinyl resin segment (A2) is preferably 90% by mass or more, more preferably 95% by mass or more. , More preferably 99% by mass or more, more preferably 100% by mass.

(Bi-reactive monomer)
The composite resin (a _h ) preferably further contains a structural unit derived from a bi-reactive monomer. When a bi-reactive monomer is used as a raw material monomer of the composite resin (a _h ), the bi-reactive monomer reacts with both the polyester resin segment (A1) and the vinyl-based resin segment (A2) to form the composite resin ( a _h ) can be produced favorably.
That is, the composite resin (a _h ) of the present invention is obtained by polymerizing a raw material monomer of the polyester resin segment (A1), a raw material monomer of the vinyl resin segment (A2), and a bi-reactive monomer. preferable.
As the bi-reactive monomer, a compound having in the molecule one or more functional groups selected from a carboxy group, a hydroxyl group, an epoxy group, a primary amino group and a secondary amino group, and an ethylenically unsaturated bond Is mentioned. Among these, from the viewpoint of reactivity, a compound having at least one selected from a hydroxyl group and a carboxy group and an ethylenically unsaturated bond, and a compound having a carboxy group and an ethylenically unsaturated bond are more preferable. .

Specifically, examples of the amphoteric monomer include acrylic acid, methacrylic acid, maleic acid, and maleic anhydride. From the viewpoint of the reactivity of the polycondensation reaction and the addition polymerization reaction, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred.
The amount of the amphoteric monomer used is preferably at least 0.5 part by mass, more preferably at least 1.0 part by mass, based on 100 parts by mass of the vinyl monomer which is a raw material of the vinyl resin segment (A2). It is more preferably at least 1.5 parts by mass, and preferably at most 10 parts by mass, more preferably at most 6 parts by mass, more preferably at most 5 parts by mass.

[Reaction conditions when step 1b is included]
The composite resin (a _h ) is preferably manufactured as any one of the following steps (1) to (3). In addition, it is preferable that the amphoteric monomer is supplied to the reaction system together with the raw material monomer of the vinyl resin segment (A2) from the viewpoint of reactivity. From the same viewpoint, a catalyst such as an esterification catalyst and an esterification co-catalyst may be used, and a polymerization initiator and a polymerization inhibitor may be used.

(1) After step 1a of reacting an alcohol component (a-al), a carboxylic acid component (a-ac), and optionally polyethylene terephthalate (a-pet), a raw material vinyl of the vinyl resin segment (A2) is obtained. Performing step 1b of the addition polymerization reaction with the monomer and optionally a bi-reactive monomer.
In step 1a, a part of the carboxylic acid component (a-ac) is subjected to a polycondensation reaction, and then, after performing step 1b, the reaction temperature is increased again to remove the remaining carboxylic acid component (a-ac). More preferred is a method of adding to the polymerization system to further advance the polycondensation reaction in step 1a and, if necessary, the reaction with a bi-reactive monomer.

(2) After the step 1b of the addition polymerization reaction with the raw material vinyl monomer of the vinyl-based resin segment (A2) and optionally a bireactive monomer, an alcohol component (a-al), a carboxylic acid component (a-ac), Optionally performing step 1a of reacting with polyethylene terephthalate (a-pet).
The alcohol component (a-al) and the carboxylic acid component (a-ac) are allowed to exist in the reaction system at the time of the addition polymerization reaction, and at an appropriate temperature for the polycondensation reaction, the esterification catalyst and, if necessary, the esterification catalyst. A polycondensation reaction can be started by adding a co-catalyst, or an alcohol component (a-al) and a carboxylic acid component (a-ac) are added to the reaction system at a temperature suitable for the polycondensation reaction. ) Can also initiate the polycondensation reaction. In the former case, the molecular weight and the molecular weight distribution can be adjusted by adding an esterification catalyst and, if necessary, an esterification promoter at a temperature suitable for the polycondensation reaction.

(3) Step 1a of reacting an alcohol component (a-al), a carboxylic acid component (a-ac), and optionally polyethylene terephthalate (a-pet), and a raw vinyl monomer for a vinyl-based resin segment (A2) And optionally performing step 1b of the addition polymerization reaction with the amphoteric monomer in parallel.
In this method, the steps 1a and 1b are performed under reaction temperature conditions suitable for the addition polymerization reaction, the reaction temperature is increased, and the polyester resin segment (if necessary) under the temperature conditions suitable for the polycondensation reaction. It is preferable to add the trivalent or higher valent starting monomer of A1) as a crosslinking agent to the polymerization system, and to further carry out the polycondensation reaction in step 1a. At that time, under a temperature condition suitable for the polycondensation reaction, a radical polymerization inhibitor can be added to advance only the polycondensation reaction. The amphoteric monomer participates in the polycondensation reaction together with the addition polymerization reaction.
Among them, (1) is preferable because the degree of freedom of the reaction temperature of the polycondensation reaction is high. The steps (1) to (3) are preferably performed in the same container.

The polyester resin used as the polyester resin segment (A1) can be produced by polycondensing an alcohol component (a-al), a carboxylic acid component (a-ac), and optionally a polyester (a-pet). .
The types of the alcohol component (a-al) and the carboxylic acid component (a-ac), which are the raw materials of the polyester resin, and the reaction conditions are determined according to the alcohol component (a-al), which is the raw material of the polyester resin of the composite resin (a _h ). ) And the type of the carboxylic acid component (a-ac), and the reaction conditions, and the preferred embodiments are also the same.

From the viewpoint of reactivity, the temperature of the addition polymerization reaction in step 1b is preferably 110 ° C or higher, more preferably 130 ° C or higher, more preferably 150 ° C or higher, and preferably 220 ° C or lower, more preferably 190 ° C or lower. ° C or lower, more preferably 170 ° C or lower. Further, it is preferable to accelerate the reaction by reducing the pressure of the reaction system in the latter half of the polymerization.
In step 1b, it is preferable to add a polymerization inhibitor. Examples of the polymerization inhibitor include 4-t-butylcatechol and the like.

[Physical properties of resin (a)]
Resin (a) is preferably an amorphous polyester resin.
In the present invention, the term “amorphous” refers to the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter (DSC), (softening point (° C.)) / (Maximum endothermic peak temperature (° C.)). Means that the crystallinity index defined by the formula is more than 1.4 or less than 0.6. The crystallinity index can be appropriately determined depending on the types and ratios of the raw material monomers and production conditions.

  The acid value of the resin (a) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, further preferably 15 mgKOH / g or more, and more preferably 15 mgKOH / g or more, from the viewpoint of improving the low-temperature fixability and durability of the toner. Is 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 27 mgKOH / g or less.

The softening point of the resin (a) is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, even more preferably 90 ° C. or higher, and from the same viewpoint, preferably 165 ° C. or lower, more preferably 130 ° C. or lower And more preferably 110 ° C. or lower.
When two or more polyester resins are used in combination, the glass transition temperature and the softening point are values obtained by a method described in Examples as a mixture of two or more polyester resins.

  The glass transition temperature of the resin (a) is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, further more preferably 50 ° C. or higher, and preferably 90, from the viewpoint of improving the low-temperature fixability and durability of the toner. ° C or lower, more preferably 80 ° C or lower, still more preferably 70 ° C or lower.

  The number average molecular weight of the resin (a) is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more, from the viewpoint of improving the low-temperature fixability and durability of the toner. It is preferably at most 6,000, more preferably at most 5,000, even more preferably at most 4,000.

  The weight average molecular weight of the resin (a) is preferably 6,000 or more, more preferably 8,000 or more, and still more preferably 9,000 or more, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. It is preferably at most 100,000, more preferably at most 80,000, even more preferably at most 50,000.

The acid value, softening point, glass transition temperature, and average molecular weight of the resin (a) can be appropriately adjusted according to the type and ratio of the raw material monomers, and the production conditions such as reaction temperature, reaction time, and cooling rate. , And their values are determined by the method described in Examples below.
When two or more resins (a) are used in combination, the softening point, glass transition temperature, and acid value obtained as a mixture thereof are preferably within the above ranges.

<Step 2>
In step 2, an alcohol component (b-al), a carboxylic acid component (b-ac), and polyethylene terephthalate (b-pet) are reacted to obtain a shell resin (b).

[Alcohol component (b-al)]
Examples of the alcohol component (b-al) include the same as the alcohol component (a-al).
As the aliphatic diol, an aliphatic diol having 2 to 6 carbon atoms is preferable, and ethylene glycol is more preferable.
The aliphatic diol having a hydroxyl group bonded to a secondary carbon atom and having 3 to 6 carbon atoms is preferably at least one selected from 1,2-propanediol and 2,3-butanediol, more preferably 1,2-propanediol.

As the aromatic diol, a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A are preferable, and a propylene oxide adduct of bisphenol A is more preferable.
The alkylene oxide adduct of bisphenol A is preferably an ethylene oxide adduct of bisphenol A (polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane) and a propylene oxide adduct of bisphenol A (polyoxypropylene- 2,2-bis (4-hydroxyphenyl) propane), and more preferably an ethylene oxide adduct of bisphenol A from the viewpoint of enhancing the durability of the toner.

Among these, the alcohol component (b-al) is preferably at least one selected from aliphatic diols having 2 to 6 carbon atoms, an alkylene oxide adduct of bisphenol A, and hydrogenated bisphenol A, More preferably, it is at least one selected from aliphatic diols having 2 to 6 carbon atoms and an alkylene oxide adduct of bisphenol A, and still more preferably aliphatic diols having 2 to 6 carbon atoms. Is 1,2-propanediol.
The alcohol component can be used alone or in combination of two or more.

In step 2, the compounding amount of the aliphatic diol having 2 to 6 carbon atoms is preferably at least 40 mol%, preferably at least 50 mol%, based on the total amount of the alcohol component and the ethylene glycol derived from polyethylene terephthalate. It is more preferably at least 65 mol%, further preferably at least 70 mol%, and preferably at most 80 mol%, more preferably at most 75 mol%.
In step 2, the compounding amount of the alkylene oxide adduct of bisphenol A is preferably at least 30 mol%, more preferably at least 50 mol%, more preferably at least 30 mol%, based on the total amount of the ethylene glycol derived from the alcohol component and polyethylene terephthalate. It is at least 65 mol%, more preferably at least 70 mol%, and preferably at most 80 mol%.

The alcohol component (b-al) may contain another polyhydric alcohol other than the alkylene oxide adduct of bisphenol A. Other polyhydric alcohol components that may be contained in the alcohol component (b-al) are the same as the polyhydric alcohol component (a-al) constituting the resin (a) described above. Examples thereof include aromatic diols, alicyclic diols, trihydric or higher polyhydric alcohols, and adducts of alkylene oxides having 2 to 4 carbon atoms (average addition mole number of 1 to 16).
These alcohol components (b-al) can be used alone or in combination of two or more.

[Carboxylic acid component (b-ac)]
Examples of the carboxylic acid component (b-ac) include those similar to the carboxylic acid component (a-ac). Among them, dicarboxylic acids are preferable, and it is more preferable to use a dicarboxylic acid and a trivalent or higher polycarboxylic acid in combination.

  The dicarboxylic acid is preferably at least one selected from aromatic dicarboxylic acids and aliphatic dicarboxylic acids, and more preferably aromatic dicarboxylic acids.

The aliphatic dicarboxylic acid has a carbon number of preferably 2 or more, more preferably 3 or more, and preferably 30 or less, more preferably 20 or less, from the viewpoint of improving the low-temperature fixability and durability of the toner. .
Examples of the aliphatic dicarboxylic acid having 2 to 30 carbon atoms include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid And succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. From the viewpoint of improving the charging characteristics of the toner, fumaric acid is preferred. Specific examples of 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, and octenyl succinic acid.
Among these, at least one selected from terephthalic acid, fumaric acid, and dodecenyl succinic acid is preferable, and terephthalic acid is more preferable.

  In the step 2, the compounding amount of the dicarboxylic acid is preferably at least 30 mol%, preferably at least 50 mol%, more preferably at least 65 mol%, based on the total amount of the carboxylic acid component and the ethylene glycol derived from polyethylene terephthalate. , More preferably at least 70 mol%, and preferably at most 80 mol%.

The trivalent or higher carboxylic acid is preferably at least one selected from trimellitic acid and acid anhydrides thereof, and more preferably trimellitic acid, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. It is anhydrous.
When the polycarboxylic acid containing a tri- or higher polycarboxylic acid is contained, the amount is preferably 3 mol% or more, more preferably 5 mol% or more, and preferably 30 mol%, in the carboxylic acid component (b-ac). Mol% or less, more preferably 20 mol% or less.
These carboxylic acid components (b-ac) can be used alone or in combination of two or more.

[Polyethylene terephthalate (b-pet)]
The polyethylene terephthalate suitably used as polyethylene terephthalate (b-pet) is the same as that described in the above (a-pet).

  In step 2, the equivalent ratio (COOH group / OH group) of the carboxylic acid component (b-ac) to the alcohol component (b-al) is preferably 0.7 or more, more preferably 0.8 or more, and , Preferably 1.2 or less, more preferably 1.1 or less, and still more preferably 1.05 or less.

(Physical properties of resin (b))
Resin (b) is preferably an amorphous polyester resin.
An amorphous polyester resin is a polyester resin having a crystallinity index of more than 1.4 or less than 0.6. The crystallinity index can be adjusted according to the types and ratios of the raw material monomers and the production conditions (eg, reaction temperature, reaction time, cooling rate, etc.), and the values thereof are described in Examples described later. Required by method.

  The acid value of the resin (b) is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, further preferably 15 mgKOH / g or more, and more preferably 15 mgKOH / g or more, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. Is 35 mgKOH / g or less, more preferably 30 mgKOH / g or less, and even more preferably 27 mgKOH / g or less.

  The softening point of the resin (b) is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, further preferably 110 ° C. or higher, and preferably 160 ° C., from the viewpoint of enhancing the low-temperature fixability and durability of the toner. Below, more preferably 140 ° C or less, still more preferably 130 ° C or less.

  The glass transition temperature of the resin (b) is preferably 40 ° C. or higher, more preferably 50 ° C. or higher, further more preferably 60 ° C. or higher, and preferably 90, from the viewpoint of improving the low-temperature fixability and durability of the toner. ° C or lower, more preferably 80 ° C or lower, still more preferably 70 ° C or lower.

  The number average molecular weight of the resin (b) is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. It is preferably at most 6,000, more preferably at most 5,000, even more preferably at most 4,000.

  The weight average molecular weight of the resin (b) is preferably 6,000 or more, more preferably 8,000 or more, further preferably 9,000 or more, from the viewpoint of improving the low-temperature fixability and durability of the toner. It is preferably at most 100,000, more preferably at most 80,000, even more preferably at most 50,000.

The acid value, softening point, glass transition temperature, and average molecular weight of the resin (b) can be appropriately adjusted depending on the kind and ratio of the raw material monomers, and the production conditions such as the reaction temperature, the reaction time, and the cooling rate. , And their values are determined by the method described in Examples described later.
When two or more resins (b) are used in combination, the softening point, glass transition temperature, and acid value obtained as a mixture thereof are preferably within the above ranges.

[Reaction conditions of step 2]
The polyester resin of the resin (b) may be prepared, for example, by mixing the alcohol component (b-al), the carboxylic acid component (b-ac), and polyethylene terephthalate (b-pet) in an inert gas atmosphere, if necessary. It can be produced by polycondensation using an esterification catalyst, a co-catalyst, a radical polymerization inhibitor and the like.
The esterification catalyst, co-catalyst, and radical polymerization inhibitor may be the same as those used in the synthesis of the resin (a), and the production conditions are preferably in the same range.

<Step 3>
In step 3, aggregated particles (I) are obtained from an aqueous dispersion containing the core resin (a) and a release agent. In this step, preferably, an aqueous dispersion containing the resin for core (a) and a release agent is prepared, and then aggregated particles (I) are obtained from the dispersion. More preferably, the resin containing the resin for core (a) An aqueous dispersion of the particles (X) and an aqueous dispersion of the release agent are respectively prepared, then the dispersions are mixed, and then the aggregated particles (I) are obtained from the obtained dispersion.

As the aqueous medium used for the aqueous dispersion, those containing water as a main component are preferable, from the viewpoint of improving the dispersion stability of the aqueous dispersion, and from the viewpoint of environmental friendliness, the content of water in the aqueous medium is preferably Is 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, further preferably 98% by mass or more, and still more preferably 100% by mass. As the water, deionized water or distilled water is preferable.
Components other than water that can constitute an aqueous medium together with water include alkyl alcohols having 1 to 5 carbon atoms; dialkyl ketones having 3 to 5 carbon atoms, such as acetone and methyl ethyl ketone; and soluble in water, such as cyclic ethers such as tetrahydrofuran. Organic solvent is used. Among these, from the viewpoint of preventing the organic solvent from being mixed into the toner, an alkyl alcohol having 1 to 5 carbon atoms that does not dissolve the polyester resin is preferable, and methanol, ethanol, isopropanol, and butanol are more preferable.

[Aqueous dispersion of resin particles (X)]
The resin particles (X) include, for example, a resin component containing the resin (a) and, if necessary, an optional component such as a release agent and a colorant (hereinafter, the resin component and the optional component are collectively referred to as “resin component, etc.” Is also dispersed in an aqueous medium to obtain an aqueous dispersion.
Examples of a method for obtaining an aqueous dispersion of the resin particles (X) include a method in which a resin component or the like is added to an aqueous medium and dispersion treatment is performed using a disperser or the like. A method of phase addition emulsification by gradually adding (phase inversion emulsification) and the like can be mentioned. Among these, a method using phase inversion emulsification is preferable from the viewpoint of improving the low-temperature fixability and durability of the toner.

(Phase inversion emulsification method)
As the phase inversion emulsification method, a method in which a resin component or the like is dissolved in an organic solvent and an aqueous medium is added to the obtained solution to carry out phase inversion emulsification (A), or a method in which the resin component or the like is melted and mixed. A method (B) in which an aqueous medium is added to the obtained resin mixture to carry out phase inversion emulsification. The method (A) is preferred from the viewpoint of obtaining a homogeneous aqueous dispersion of the resin particles (X).

In the method (A), it is preferable to first dissolve a resin component or the like in an organic solvent to obtain a solution of the resin component or the like in an organic solvent, and then add an aqueous medium to the solution to perform phase inversion emulsification.
The organic solvent used in the phase inversion emulsification method has a solubility parameter (SP value: POLYMER HANDBOOK THIRD EDITION 1989 by John Wiley & Sons, Inc), preferably 15.0 MPa ^1/2 or more, more preferably 16.0 MPa. ^1/2 or more, more preferably 17.0 MPa ^1/2 or more, and preferably 26.0 MPa ^1/2 or less, more preferably 24.0 MPa ^1/2 or less, and still more preferably 22.0 MPa ^1/2. It is as follows.
Examples of the organic solvent include alcohol solvents such as ethanol (26.0), isopropanol (23.5) and isobutanol (21.5); acetone (20.3), methyl ethyl ketone (19.0), and methyl isobutyl ketone ( 17.2), ketone solvents such as diethyl ketone (18.0); ether solvents such as dibutyl ether (16.5), tetrahydrofuran (18.6), dioxane (20.5); ethyl acetate (18. 6) and acetic acid ester solvents such as isopropyl acetate (17.4). The numerical value in parentheses after each solvent is the respective SP value (unit: MPa ^1/2 ). Among these, from the viewpoint of easy removal from the mixed solution after the addition of the aqueous medium, preferably one or more selected from ketone solvents and acetate solvents, more preferably selected from methyl ethyl ketone, ethyl acetate and isopropyl acetate. Or more, more preferably methyl ethyl ketone.

In the phase inversion emulsification method, it is preferable to treat the resin with a neutralizing agent.
Examples of the neutralizing agent include basic substances. Examples of the basic substance include hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; nitrogen-containing basic compounds such as ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, diethanolamine, triethanolamine, and tributylamine. And the like. Of these, from the viewpoint of improving the dispersion stability and cohesiveness of the resin particles (X), preferably at least one selected from ammonia and hydroxides of alkali metals, more preferably ammonia And at least one selected from sodium hydroxide and sodium hydroxide, and more preferably ammonia.

The use equivalent (mol%) of the neutralizing agent to the acid groups of the resin is preferably 10 mol% or more, more preferably 30 mol% or more, and preferably 150 mol% or less, more preferably 120 mol%. Or less, more preferably 100 mol% or less.
In addition, the use equivalent (mol%) of a neutralizing agent can be calculated | required by the following formula.
Equivalent weight (mol%) of neutralizing agent = [{addition mass of neutralizing agent (g) / equivalent weight of neutralizing agent] / [{acid value of resin (mg KOH / g) × weight of resin (g)} / (56 × 1000)]] × 100

From the viewpoint of improving the dispersion stability of the resin particles (X), the temperature at which the aqueous medium is added is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, even more preferably 50 ° C. or higher, and preferably Is 90 ° C. or lower, more preferably 80 ° C. or lower, still more preferably 70 ° C. or lower.
From the viewpoint of obtaining the resin particles (X) having a small particle diameter, the addition rate of the aqueous medium is preferably 100 parts by mass of the resin (a) constituting the resin particles (X) until the phase inversion is completed. 0.1 parts by mass / min or more, more preferably 0.5 parts by mass / min or more, still more preferably 3 parts by mass / min or more, and preferably 50 parts by mass / min or less, more preferably 30 parts by mass. / Min or less, more preferably 20 parts by mass / min or less, more preferably 10 parts by mass / min or less. The rate of addition of the aqueous medium after the phase inversion is not limited.

  After the phase inversion emulsification, if necessary, a step of removing the organic solvent from the obtained dispersion may be provided. The method for removing the organic solvent is preferably distillation since the organic solvent is dissolved in water. The residual amount of the organic solvent in the aqueous dispersion is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably substantially 0%.

The solid concentration of the aqueous dispersion of the resin particles (X) is preferably 5% by mass or more from the viewpoint of improving the productivity of the toner and improving the dispersion stability of the aqueous dispersion of the resin particles (X). , More preferably at least 10% by mass, even more preferably at least 15% by mass, and preferably at most 50% by mass, more preferably at most 40% by mass, still more preferably at most 30% by mass, still more preferably at most 25% by mass. It is as follows. The solid content is the total amount of nonvolatile components such as a resin, a colorant, and a surfactant.
The content of the core resin (a) in the solid content of the aqueous dispersion of the resin particles (X) is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more. And 100% by mass or less, preferably 98% by mass or less.

The volume median particle diameter (D ₅₀ ) of the resin particles (X) in the aqueous dispersion is preferably at least 0.05 μm, more preferably at least 0.10 μm, even more preferably at least 0.12 μm, and preferably Is 0.80 μm or less, more preferably 0.40 μm or less, and still more preferably 0.20 μm or less.
The CV value of the resin particles (X) is preferably 5% or more, more preferably 15% or more, and still more preferably 20% or more, from the viewpoint of improving the productivity of the aqueous dispersion of the resin particles (X). From the viewpoint of obtaining a toner capable of obtaining a high quality image, the content is preferably 50% or less, more preferably 40% or less, and further preferably 30% or less.

〔Release agent〕
The melting point of the release agent is preferably 60 ° C. or higher, more preferably 65 ° C. or higher, further preferably 70 ° C. or higher, further more preferably 73 ° C. or higher, from the viewpoint of improving the low-temperature fixability of the toner. Is 100 ° C. or less, more preferably 95 ° C. or less, still more preferably 90 ° C. or less, and still more preferably 85 ° C. or less.
In the present invention, the melting point of the release agent is raised to 200 ° C. using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), and the temperature is decreased at a rate of 10 ° C./min. The sample cooled to 0 ° C. is measured at a heating rate of 10 ° C./min, and the maximum peak temperature of the heat of fusion is defined as the melting point. When two or more release agents are used in combination, the melting point of the release agent is determined by the melting point of the release agent having the largest mass ratio among the release agents contained in the obtained toner. Melting point. In addition, when all the ratios are the same, the lowest value is set.

Examples of the release agent include wax.
Examples of the wax include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicone waxes; fatty acid amides such as oleamide and stearamide; plant waxes such as carnauba wax, rice wax and candelilla wax; animals such as beeswax. Mineral wax such as montan wax, paraffin wax, and Fischer-Tropsch wax; and synthetic wax such as ester wax. These release agents can be used alone or in combination of two or more. Among them, from the viewpoint of improving the low-temperature fixability of the toner, at least one kind selected from carnauba wax and paraffin wax, and more preferably paraffin wax is preferred.

  The amount of the release agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and still more preferably 3 parts by mass, based on 100 parts by mass of the binder resin in the toner, from the viewpoint of improving the low-temperature fixability of the toner. It is at least 20 parts by mass, preferably at most 20 parts by mass, more preferably at most 15 parts by mass, even more preferably at most 10 parts by mass.

  The release agent particles are preferably obtained as a dispersion in which the release agent is dispersed in an aqueous medium. Specifically, it is preferable to obtain the release agent and the aqueous medium by dispersing them in the presence of a surfactant or the like at a temperature equal to or higher than the melting point of the release agent using a disperser.

Examples of the disperser used include a homogenizer, an ultrasonic disperser, and a high-pressure disperser.
As the ultrasonic disperser, for example, an ultrasonic homogenizer can be mentioned. Commercially available products include “US-150T”, “US-300T”, “US-600T” (manufactured by Nippon Seiki Seisakusho), “SONIFIER (registered trademark) 4020-400”, and “SONIFIER (registered trademark) 4020”. -800 "(manufactured by Branson).
As a device that is commercially available as a high-pressure disperser, a high-pressure wet-type atomization device “Nanomizer (registered trademark) NM2-L200-D08” (manufactured by Yoshida Kikai Co., Ltd.) can be mentioned.
Before using the disperser, it is preferable that the releasing agent, the surfactant, and the aqueous medium are preliminarily dispersed by a mixer such as a homomixer or a ball mill.
The preferred embodiment of the aqueous medium of the release agent is the same as the aqueous medium used for obtaining the aqueous dispersion of the resin particles (X).

The dispersion of the release agent particles in the aqueous medium is preferably 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.
Examples of the surfactant include anionic surfactants such as sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, sodium lauryl ether sulfate and dipotassium alkenyl succinate; cationic surfactants; nonionic surfactants and the like. From the viewpoint of improving the dispersion stability of the mold agent particles, and from the viewpoint of improving the cohesion of the release agent particles and the resin particles, an anionic surfactant is preferable, and dipotassium alkenyl succinate is more preferable.

  The content of the surfactant in the aqueous release agent dispersion is from the viewpoint of improving the dispersion stability of the release agent particles and the viewpoint of improving the cohesiveness of the release agent particles at the time of preparing the toner and preventing liberation. From 0.1% by mass or more, more preferably 0.3% by mass or more, still more preferably 0.5% by mass or more, and preferably 5.0% by mass or less, more preferably 3.0% by mass or less. % By mass or less.

  The solid content concentration of the release agent particle dispersion is preferably 5% by mass or more, more preferably 10% by mass, from the viewpoint of improving the productivity of the toner and the dispersion stability of the release agent particle dispersion. %, More preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less.

The volume median particle size (D ₅₀ ) of the release agent particles is preferably 0.10 μm or more, more preferably 0.20 μm or more, and still more preferably 0.30 μm or more, from the viewpoint of obtaining uniform aggregated particles. And it is preferably 1.0 μm or less, more preferably 0.80 μm or less, and still more preferably 0.60 μm or less.

  The CV value of the release agent particles is preferably 10% or more, more preferably 25% or more from the viewpoint of improving the productivity of the toner, and is preferably 50% or less from the viewpoint of obtaining uniform aggregated particles. , More preferably at most 45%, even more preferably at most 42%.

(Optional components)
In the step 3, a known resin used for the toner, for example, a polyester resin other than the resin (a), a styrene-acryl copolymer, an epoxy, a polycarbonate, a polyurethane, or the like may be further blended.
In the step 3, other charge control agents, magnetic powders, flow improvers, conductivity adjusters, extenders, reinforcing fillers such as fibrous substances, antioxidants, antioxidants, cleaning improvers, etc. Additives may be appropriately blended.
In the present specification, a resin component including the resin (a) and the above-mentioned known resin optionally used may be referred to as a “binder resin”.
The content of the resin (a) in the binder resin in Step 3 is preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and more preferably 100% by mass.

(Colorant)
The coloring agent is not particularly limited and includes known coloring agents, which can be appropriately selected according to the purpose. Specifically, carbon black, inorganic composite oxide, chrome yellow, Hansa yellow, benzidine yellow, slen yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, briliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Risole Red, Rhodamine B Lake, Lake Red C, Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, etc. Various pigments: acridine, xanthene, azo, benzoquinone, azine, anthraquinone, indico, Indigo dyes, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, include various dyes of thiazole, and the like. These can be used alone or in combination of two or more.
The content of the colorant in the toner is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the binder resin, from the viewpoint of improving the image density of the toner. It is preferably at least 1.0 part by mass, and preferably at most 40 parts by mass, more preferably at most 20 parts by mass, more preferably at most 10 parts by mass.

(Colorant dispersion)
When the colorant is mixed in step 3, it is preferable to use a colorant dispersion in which the colorant is dispersed in an aqueous medium.
The colorant dispersion is preferably obtained by dispersing a colorant and an aqueous medium using a disperser in the presence of a surfactant or the like. As the disperser, a homogenizer, an ultrasonic disperser, or the like is preferable.
The preferred embodiment of the aqueous medium is the same as the aqueous medium used for the aqueous dispersion of the resin particles (X).

When dispersing the colorant particles in the aqueous medium, it is preferable to carry out the dispersion in the presence of a surfactant from the viewpoint of improving the dispersion stability of the colorant particles.
Examples of the surfactant include a nonionic surfactant, an anionic surfactant, a cationic surfactant, and the like. From the viewpoint of improving the cohesiveness with X) and the resin particles (Y), an anionic surfactant is preferred. Specific examples include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium lauryl ether sulfate, dipotassium alkenylsuccinate and the like, and preferably sodium dodecylbenzenesulfonate.

  The content of the surfactant in the colorant dispersion is preferably from the viewpoint of improving the dispersion stability of the colorant particles, and from the viewpoint of improving the cohesiveness of the colorant particles during toner preparation and preventing liberation. 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1.0% by mass or more, and preferably 5.0% by mass or less, more preferably 4.5% by mass or less. is there.

  The solid content concentration of the colorant particle dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of improving the productivity of the toner and improving the dispersion stability of the colorant particle dispersion. And more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

The volume median particle size (D ₅₀ ) of the colorant particles is preferably 0.050 μm or more, more preferably 0.080 μm or more, and still more preferably 0.10 μm or more, from the viewpoint of obtaining a toner from which a high-quality image can be obtained. And preferably 0.50 μm or less, more preferably 0.30 μm or less, and still more preferably 0.15 μm or less.

(Charge control agent)
Examples of the charge control agent include a chromium-based azo dye, an iron-based azo dye, an aluminum azo dye, and a salicylic acid metal complex. These may be used alone or in combination of two or more.
The content of the charge control agent in the toner is preferably at least 0.01 part by mass, more preferably at least 0.1 part by mass, based on 100 parts by mass of the binder resin, from the viewpoint of the charging stability of the toner. Preferably it is 0.2 parts by mass or more, and preferably 3.0 parts by mass or less, more preferably 2.0 parts by mass or less, more preferably 1.5 parts by mass or less.

When the charge control agent is mixed in step 3, it is preferable to use a charge control agent dispersion in which the charge control agent is dispersed in an aqueous medium.
The charge control agent dispersion is preferably obtained by dispersing a charge control agent and an aqueous medium using a disperser in the presence of a surfactant or the like. As the disperser, a sand grinder, a homogenizer, an ultrasonic disperser or the like is preferable. The type and content of the surfactant are the same as those of the above-mentioned preferred examples of the colorant dispersion.

  The solid concentration of the charge control agent dispersion is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of improving the productivity of the toner and the dispersion stability of the charge control agent dispersion. And more preferably 15% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less.

The volume median particle size (D ₅₀ ) of the charge control agent particles is preferably 0.050 μm or more, more preferably 0.080 μm or more, and still more preferably 0.10 μm, from the viewpoint of obtaining a toner from which a high-quality image can be obtained. And preferably 0.50 μm or less, more preferably 0.30 μm or less, and even more preferably 0.15 μm or less.

(Flocculant)
When a dispersion of the aggregated particles (I) is obtained in step 3, it is preferable to add an aggregating agent from the viewpoint of efficiently performing aggregation.
The coagulant is preferably an electrolyte, and more preferably a salt, from the viewpoint of obtaining a toner having a desired particle size while preventing excessive coagulation. Examples of the coagulant include a cationic surfactant of a quaternary salt, an organic coagulant such as polyethyleneimine; an inorganic coagulant such as an inorganic metal salt, an inorganic ammonium salt, and a divalent or higher metal complex. Among these, from the viewpoint of improving cohesiveness and obtaining uniform aggregated particles, an inorganic coagulant is preferable, an inorganic metal salt and an inorganic ammonium salt are more preferable, and an inorganic ammonium salt is more preferable.
The valence of the cation of the inorganic coagulant is preferably pentavalent or less, more preferably divalent or less, and still more preferably monovalent, from the viewpoint of obtaining a toner having a desired particle size while preventing excessive aggregation. Examples of the monovalent cation of the inorganic coagulant include a sodium ion, a potassium ion, and an ammonium ion. Among these, an ammonium ion is preferred.
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 the inorganic ammonium salt include ammonium sulfate, ammonium chloride, and ammonium nitrate.
The coagulant is more preferably ammonium sulfate.

  The amount of the coagulant to be used is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 100 parts by mass of the resin (a), from the viewpoint of controlling the aggregation to obtain a desired particle size. It is 20 parts by mass or more, and preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and still more preferably 40 parts by mass or less.

The coagulant is preferably added dropwise to the mixed dispersion. The coagulant may be added at a time, intermittently or continuously. It is preferable to perform sufficient stirring during and after the addition.
The coagulant is preferably added dropwise as an aqueous solution from the viewpoint of controlling the coagulation to obtain coagulated particles having a desired particle size, and the concentration of the coagulant aqueous solution is preferably 2% by mass or more, more preferably 4% by mass. The above is still more preferably 6% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, and further preferably 10% by mass or less.

[Step 3 conditions]
The temperature for aggregation in step 3 is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and still more preferably 15 ° C. or higher, from the viewpoint of controlling the aggregation to obtain aggregated particles (I) having a desired particle size. And it is preferably 40 ° C. or lower, more preferably 30 ° C. or lower.
Further, from the viewpoint of controlling the aggregation to obtain aggregated particles having a desired particle size and particle size distribution, it is preferable to use the aqueous solution of the aggregating agent after adjusting the pH to 7.0 or more and 9.0 or less.

  The dropping time of the coagulant is preferably 1 minute or more, more preferably 3 minutes or more, from the viewpoint of controlling the aggregation to obtain the aggregated particles having a desired particle size, and from the viewpoint of improving the productivity of the toner. , Preferably 120 minutes or less, more preferably 60 minutes or less, and still more preferably 40 minutes or less.

Further, from the viewpoint of accelerating aggregation and obtaining aggregated particles having a desired particle size and particle size distribution, it is preferable to increase the temperature of the dispersion after adding the aggregating agent. The holding temperature is preferably 45 ° C. or higher, more preferably 50 ° C. or higher, and is preferably 70 ° C. or lower, more preferably 60 ° C. or lower, and further preferably 55 ° C. or lower.
It is preferable to confirm the progress of aggregation by monitoring the volume median particle diameter (D ₅₀ ) of the aggregated particles in the above temperature range.

[Agglomerated particles (I)]
The volume median particle size (D ₅₀ ) of the obtained aggregated particles (I) is preferably 2 μm or more, more preferably 3 μm or more, and still more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less. , More preferably 6 μm or less. The volume median particle diameter (D ₅₀ ) of the aggregated particles (I) can be determined by the method described in Examples described later.

<Step 4>
In Step 4, the resin for shell (b) is added to the aggregated particles (I) obtained in Step 3 to obtain a dispersion of the aggregated particles (II). In the step 4, preferably, a dispersion of the resin particles (Y) containing the resin (b) is added to the aggregated particles (I) obtained in the step 3, and the aggregated particles (Y) This is a step of obtaining aggregated particles (II) containing I).

[Aqueous dispersion of resin particles (Y)]
The resin particles (Y) are produced by a method in which a resin component containing the resin (b) is dispersed in an aqueous medium to obtain an aqueous dispersion of the resin particles (Y).
The resin particles (Y) are preferably obtained by dispersing a resin component containing the resin (b) and, if necessary, the above-mentioned optional components in an aqueous medium to obtain an aqueous dispersion of the resin particles (Y).
The method for obtaining the aqueous dispersion is the same as that for the resin particles (X).

From the viewpoint of improving the dispersion stability of the resin particles (Y), it is preferable to add a neutralizing agent to the solution. Preferred embodiments of the neutralizing agent are the same as in the production of the resin particles (X).
The use equivalent (mol%) of the neutralizing agent to the acid groups of the resin is preferably 10 mol% or more, more preferably 30 mol% or more, and preferably 150 mol% or less, more preferably 120 mol%. Or less, more preferably 100 mol% or less.

The preferable range of the temperature, the addition speed, and the solid content concentration of the obtained aqueous dispersion of the resin particles (Y) at the time of adding the aqueous medium are the same as the preferable ranges exemplified for the resin particles (X) described above.
The content of the resin (b) in the solid content of the aqueous dispersion of the resin particles (Y) is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more, and , 100% by mass or less, preferably 98% by mass or less.

The volume median particle diameter (D ₅₀ ) of the resin particles (Y) in the aqueous dispersion is preferably 0.05 μm or more, more preferably 0.08 μm or more, from the viewpoint of obtaining a toner capable of obtaining a high-quality image. It is more preferably at least 0.10 μm, and preferably at most 0.50 μm, more preferably at most 0.40 μm, even more preferably at most 0.30 μm.

  Further, the CV value of the resin particles (Y) is preferably 5% or more, more preferably 10% or more, and still more preferably 15% or more, from the viewpoint of improving the productivity of the aqueous dispersion of the resin particles (Y). From the viewpoint of obtaining a toner capable of obtaining a high-quality image, the content is preferably 50% or less, more preferably 40% or less, and further preferably 30% or less.

The resin particles (Y) contain, in addition to the resin (b), a known resin used for the toner, for example, a polyester resin other than the resin (b), a styrene-acryl copolymer, an epoxy, a polycarbonate, a polyurethane, and the like. be able to.
The content of the resin (b) in all the resin components contained in the resin particles (Y) is preferably 80% by mass or more, more preferably 90% by mass or more, from the viewpoint of improving low-temperature fixability and durability of the toner. More preferably, it is at least 95% by mass, more preferably 100% by mass.
Further, the colorant and the charge control agent may be contained in the resin particles (Y) as necessary. Further, as long as the effects of the present invention are not impaired, a reinforcing filler such as a fibrous substance and the like, and additives such as an antioxidant and an antioxidant may be contained.

(Aggregation stop agent)
In step 4, aggregation is preferably stopped by adding an aggregation stopping agent.
As the aggregation terminator, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl sulfate, alkyl ether sulfate, polyoxyalkylene alkyl ether sulfate, and the like, preferably polyoxyalkylene alkyl ether sulfate, more preferably polyoxyethylene. Lauryl ether sulfate, more preferably sodium polyoxyethylene lauryl ether sulfate.
Aggregation terminators can be used alone or in combination of two or more.
The addition amount of the aggregation terminator is preferably 0.1 part by mass or more, based on 100 parts by mass of the total amount of the resin particles (X) and the resin particles (Y), from the viewpoint of reliably preventing unnecessary aggregation. It is preferably at least 1 part by mass, more preferably at least 2 parts by mass, and from the viewpoint of reducing the residual on the toner, preferably at most 15 parts by mass, more preferably at most 10 parts by mass, further preferably at most 7 parts by mass. It is as follows. The aggregation stopper is preferably added in an aqueous solution from the viewpoint of improving the productivity of the toner.

[Step 4 conditions]
Before adding the aqueous dispersion of the resin particles (Y) to the dispersion of the aggregated particles (I), an aqueous medium may be added to the dispersion of the aggregated particles (I) for dilution. In addition, when an aqueous dispersion of the resin particles (Y) is added to the dispersion of the aggregated particles (I), the above-described aggregation is performed in order to efficiently adhere the resin particles (Y) to the aggregated particles (I). An agent may be used.

  The temperature at which the aqueous dispersion of the resin particles (Y) is added is preferably 40 ° C. or higher, more preferably 45 ° C. or higher, and still more preferably 47 ° C. or higher, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. And preferably 80 ° C. or lower, more preferably 70 ° C. or lower, even more preferably 65 ° C. or lower.

The aqueous dispersion of the resin particles (Y) may be continuously added over a certain period of time, added at one time, or added in multiple portions. It is preferable to add continuously or add in multiple portions. Such addition makes it easier for the resin particles (Y) to selectively adhere to the aggregated particles (I). Above all, from the viewpoint of promoting selective adhesion and improving the productivity of toner, it is preferable to add continuously over a certain period of time.
When the aqueous dispersion of the resin particles (Y) is continuously added, the addition speed is preferably 100 masses of the aggregated particles (I) from the viewpoint of obtaining uniform aggregated particles (II) and improving the productivity of the toner. Parts, the resin particles (Y) are preferably at least 0.03 parts by mass / min, more preferably at least 0.07 parts by mass / min, and preferably at most 1.0 part by mass / min, More preferably, it is 0.5 parts by mass / min or less, further preferably 0.3 parts by mass / min or less.

  The amount of the resin particles (Y) to be added is from the viewpoint of enhancing the low-temperature fixability and the durability of the toner, from the mass ratio of the resin particles (Y) to the total of the resin particles (X) and the resin particles (Y) [(Y ) / ((X) + (Y))] is preferably at least 0.1, more preferably at least 0.15, even more preferably at least 0.2, and preferably at most 0.9, more preferably Is an amount of 0.6 or less, more preferably 0.4 or less.

  The amount of the shell resin (b) is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 100 parts by mass of the core resin (a) contained in the aggregated particles (I). It is 20 parts by mass or more, and preferably 50 parts by mass or less, preferably 45 parts by mass or less, preferably 40 parts by mass or less.

In step 4, the aggregation may be stopped when the aggregated particles have grown to an appropriate particle size as the toner.
Examples of the method of 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, a method of adding an aggregation stopper to stop aggregation is preferable.

  From the viewpoint of improving the productivity of the toner, the temperature at which the aggregation terminator is added is preferably the same as the temperature at which the dispersion of the aggregated particles (II) is maintained, preferably at least 40 ° C, more preferably at least 45 ° C. And more preferably 47 ° C. or higher, and preferably 80 ° C. or lower, more preferably 70 ° C. or lower, and still more preferably 65 ° C. or lower.

[Agglomerated particles (II)]
In step 4, the volume median particle diameter (D ₅₀ ) of the aggregated particles (II) in the obtained dispersion is preferably 2 μm or more, more preferably 3 μm or more, from the viewpoint of enhancing the low-temperature fixability and durability of the toner. It is still more preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and still more preferably 6 μm or less.

<Step 5>
Step 5 is a step of fusing the aggregated particles (II) obtained in step 4 to obtain core-shell particles. The particles in the aggregated particles (II), which have been mainly physically attached to each other, are fused and integrated to form core-shell particles (fused particles).

In step 5, the resin constituting the resin particles (X) or the resin particles (Y) is formed from the viewpoint of improving the fusion property of the aggregated particles (II), and improving the low-temperature fixability and durability of the toner. It is preferable to maintain the temperature at or above the maximum value of the glass transition temperature of the resin.
The holding temperature is the glass transition temperature of the resin constituting the resin particles (X) or the resin constituting the resin particles (Y) from the viewpoint of improving the fusibility of the aggregated particles and the productivity of the toner. The temperature is preferably 2 ° C. or higher, more preferably 4 ° C. or higher, even more preferably 6 ° C. or higher than the maximum value, and the resin or resin particles (Y) constituting the resin particles (X) are The temperature is preferably 30 ° C. or lower, more preferably 20 ° C. or lower, more preferably 12 ° C. higher or lower than the maximum value of the glass transition temperature of the constituent resin.
At this time, the time during which the resin constituting the resin particles (X) or the resin constituting the resin particles (Y) is maintained at a temperature equal to or higher than the maximum value of the glass transition temperature improves the low-temperature fixability and durability of the obtained toner. From the viewpoint of the above, it is preferably 1 minute or more, more preferably 10 minutes or more, further preferably 30 minutes or more, and preferably 240 minutes or less, more preferably 180 minutes or less, still more preferably 120 minutes or less, and still more preferably. Is less than 90 minutes.

  In the core-shell particles, the mass ratio [resin (b) / resin (a)] of the resin (b) contained in the shell portion to the resin (a) contained in the core portion is preferably 5/100 or more, more preferably It is at least 10/100, more preferably at least 20/100, and preferably at most 60/100, more preferably at most 50/100, even more preferably at most 40/100.

The volume median particle diameter (D ₅₀ ) of the core-shell particles in the dispersion obtained in Step 5 is preferably 2 μm or more, more preferably 3 μm or more, from the viewpoint of improving the low-temperature fixability and durability of the toner. Is 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less, and still more preferably 6 μm or less.
The circularity of the core-shell particles in the dispersion obtained in Step 5 is preferably 0.955 or more, more preferably 0.960 or more, and still more preferably 0.90 or more, from the viewpoint of improving the low-temperature fixability and durability of the toner. 965 or more, and preferably 0.990 or less, more preferably 0.985 or less, and still more preferably 0.980 or less.

<Post-processing step>
A post-treatment step may be performed after step 5, and the core-shell particles may be isolated.
Since the core-shell particles in the dispersion obtained in Step 5 are present in the aqueous medium, it is preferable to first perform solid-liquid separation. For the solid-liquid separation, a suction filtration method or the like is preferably used.
Washing is preferably performed after solid-liquid separation. At this time, it is preferable that the added surfactant is also removed. Therefore, it is preferable to wash the surfactant with an aqueous medium at or below the cloud point of the surfactant. Washing is preferably performed a plurality of times.

Next, drying is preferably performed. The drying temperature is preferably such that the temperature of the core-shell particles themselves is lower than the minimum value of the glass transition temperature of the resin (a) or the resin (b). As a drying method, it is preferable to use a vacuum low-temperature drying method, a vibration-type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like. The moisture content after drying is adjusted to preferably 1.5% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of improving the charging characteristics of the toner.
It is preferable that the core-shell particles obtained by adding a fluidizing agent or the like to the surface of the core-shell particles as an external additive be used as the toner. Examples of the external additive include those described above.

(External additive)
In the toner for developing an electrostatic charge image, it is preferable to use, as the toner, the core-shell particles obtained by adding a fluidizing agent or the like as an external additive to the surface of the core-shell particles.
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 polycarbonate, polymethyl methacrylate, and polymer fine particles such as a silicone resin. Hydrophobic silica is preferred.
When the surface treatment of the core-shell particles is performed using an external additive, the amount of the external additive is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more based on 100 parts by mass of the core-shell particles. And more preferably at least 0.3 part by mass, and preferably at most 5 parts by mass, more preferably at most 4 parts by mass, even more preferably at most 3 parts by mass.

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

  The properties of the resin, resin particles, toner and the like were measured and evaluated by the following methods.

[Acid value of resin]
The acid value of the resin was measured based on the method of JIS K0070. However, only the measurement solvent was changed from a mixed solvent of ethanol and ether prescribed in JIS K 0070 to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Resin softening point, glass transition temperature, etc.]
(1) Softening Point Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), while heating 1 g of a sample at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger, and the diameter was reduced. It was extruded from a 1 mm long, 1 mm long nozzle. The plunger descent of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.
(2) Maximum temperature of endothermic peak Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), the sample was cooled from room temperature (20 ° C.) to 0 ° C. at a rate of 10 ° C./min. The sample was kept as it was for 1 minute, and then measured while heating up to 180 ° C. at a rate of 10 ° C./min. Of the endothermic peaks observed, the temperature of the peak on the highest temperature side was taken as the maximum temperature of the endothermic peak.
(3) Glass transition temperature Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of a sample is weighed in an aluminum pan, and heated to 200 ° C. Then, the temperature was lowered to 0 ° C. at a rate of temperature drop of 10 ° C./min. Next, the measurement was performed while the temperature was raised to 150 ° C. at a rate of 10 ° C./min. The temperature at the intersection of the extension line of the base line below the maximum temperature of the endothermic peak and the tangent line indicating the maximum slope from the rising portion of the peak to the peak of the peak was defined as the glass transition temperature.

[Number average molecular weight and weight average molecular weight of polyester resin]
The molecular weight distribution was measured by gel permeation chromatography (GPC) according to the following method, and the number average molecular weight Mn and the weight average molecular weight Mw of the resin were determined.
(1) Preparation of sample solution The resin was dissolved in chloroform so that the concentration became 0.5 g / 100 mL. Next, this solution was filtered using a fluororesin filter (manufactured by Sumitomo Electric Industries, Ltd., trade name: FP-200) having a pore size of 2 μm to remove insoluble components to obtain a sample solution.
(2) Measurement of molecular weight Using the following apparatus, chloroform was flowed as an eluent at a flow rate of 1 ml per minute, and the column was stabilized in a constant temperature bath at 40 ° C. 100 μl of the sample solution was injected thereinto and the measurement was performed. The molecular weight of the sample was calculated based on a previously prepared calibration curve. At this time, the calibration curve includes several types of monodisperse polystyrenes having known molecular weights (manufactured by Tosoh Corporation; 2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁵ ; manufactured by GL Sciences Corporation; 2.10 × 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) were used as standard samples.
Measuring device: CO-8010 (trade name, manufactured by Tosoh Corporation)
Analysis column: GMH _XL + G3000H _XL (all trade names, manufactured by Tosoh Corporation)

[Agglomerated Particles (I), Core-Shell Particles, and Volume Median Particle Size (D ₅₀ )]
The volume median particle diameter of the aggregated particles (I), the core-shell particles, and the toner was measured as follows.
・ Measuring machine: Coulter Multisizer III (trade name, manufactured by Beckman Coulter)
・ Aperture diameter: 50 μm
・ Analysis software: Multisizer III version 3.51 (trade name, manufactured by Beckman Coulter)
・ Electrolyte: Isoton II (trade name, manufactured by Beckman Coulter)
-Dispersion: Polyoxyethylene lauryl ether (trade name: Emulgen 109P, HLB: 13.6, manufactured by Kao Corporation) was dissolved in the electrolyte to obtain a dispersion having a concentration of 5% by mass.
Dispersion conditions: 10 mg of a measurement sample was added to 5 mL of the dispersion, dispersed for 1 minute with an ultrasonic disperser, and then 25 mL of electrolyte solution was added, and further dispersed for 1 minute with an ultrasonic disperser. A sample dispersion was prepared.
Measurement conditions: The sample dispersion was added to 100 mL of the electrolytic solution to adjust the particle size of 30,000 particles to a concentration that can be measured in 20 seconds. Then, 30,000 particles were measured, and the particle size distribution was measured. The volume median particle size (D ₅₀ ) was determined from the above.

[Volume median particle diameter (D ₅₀ ) of colorant particles, charge control agent particles and release agent particles]
(1) Measuring device: Laser diffraction type particle size analyzer "LA-920" (manufactured by Horiba, Ltd.)
(2) Measurement conditions: Distilled water was added to the measurement cell, and the volume median particle diameter (D ₅₀ ) was measured at a concentration at which the absorbance was within an appropriate range.

[Solid concentration of aqueous dispersion]
Using an infrared moisture meter "FD-230" (manufactured by Kett Science Laboratory Co., Ltd.), 5 g of the sample were dried under the conditions of a drying temperature of 150 ° C. and a measurement mode of 96 (monitoring time: 2.5 minutes / fluctuation: 0.05%). And dried, and the water content (% by mass) of the sample was measured. The solid content was calculated according to the following equation.
Solid content concentration (% by mass) = 100−moisture of sample (% by mass)

[Low-temperature fixability of toner]
The toner was mounted on an apparatus in which a fixing machine of a copying machine “AR-505” (manufactured by Sharp Corporation) was modified so that it could be fixed outside the apparatus, and a printed matter was obtained in an unfixed state (print area: 2 cm). × 12 cm, adhesion amount: 0.5 mg / cm ² ). Then, using a fixing machine (fixing speed: 300 mm / sec) adjusted so that the total fixing pressure becomes 40 kgf, the temperature of the fixing roll is gradually increased from 100 ° C. to 240 ° C. by 5 ° C., and unfixed at each temperature. A fixing test of the printed matter in the state was performed. A cellophane adhesive tape “UNICEF Cellophane” (manufactured by Mitsubishi Pencil Co., width: 18 mm, JIS Z1522) is attached to the image portion of the obtained printed matter, and a fixing roller set at 30 ° C. different from the fixing roll of the fixing machine. Then, the tape was peeled off. The optical reflection densities before and after applying the tape were measured using a reflection densitometer “RD-915” (manufactured by Gretag Macbeth), and the ratio of both (after peeling / before attaching × 100) was initially 90%. The temperature of the fixing roll exceeding the minimum fixing temperature was defined as the minimum fixing temperature. The lower the minimum fixing temperature, the better the low-temperature fixability. As the fixing paper, “Copy Bond SF-70NA” (manufactured by Sharp Corporation, 75 g / m ² ) was used.

[Heat storage stability of toner]
10 g of the toner was placed in a 50 ml polycup and kept at 55 ° C. and 60% RH for 24 hours. Thereafter, in a powder tester (manufactured by Hosokawa Micron Corporation), three sieves of a sieve A (aperture 250 μm), a sieve B (aperture 150 μm), and a sieve C (aperture 75 μm) are placed in order from the top, and placed. 10 g of the toner was placed on the sieve A and vibrated for 60 seconds. With respect to the value (α) calculated from the following equation, the fluidity was evaluated based on the following evaluation criteria. The larger the value, the better.
α = 100 − [(mass (g) of toner remaining on sieve A) + (mass (g) of toner remaining on sieve B) × 0.6 + (mass (g) of toner remaining on sieve C) × 0.2] / 10 (g) x 100

[Toner durability]
The toner is mounted on a printing machine “Page Presto N-4” (manufactured by Casio Computer Co., Ltd., fixing: contact fixing method, developing: non-magnetic one-component developing method, developing roll diameter: 2.3 cm), temperature 32 ° C., humidity Under an environment of 85%, an oblique stripe pattern having a blackening ratio of 5.5% was continuously printed. On the way, a black solid image was printed every 500 sheets, and the presence or absence of streaks on the image was confirmed. Printing was stopped when streaks occurred on the image, and printing was performed up to 9000 sheets. The number of printed sheets up to the point where the streaks were visually observed on the image was defined as the number of streaks generated by the toner being fused and fixed to the developing roll, and the durability was evaluated. That is, it can be determined that the greater the number of sheets where no streak occurs, the higher the durability of the toner.

[Production of alkenyl succinic anhydride]
Synthesis example AS1
(Production of alkylene compound (a))
Using propylene tetramer (trade name: “Light Tetramer” manufactured by Nippon Oil Co., Ltd.), the alkylene compound (a) was obtained by fractionating under heating conditions of 183 to 208 ° C. The obtained alkylene compound (a) had 40 peaks in gas chromatography mass spectrometry described later. The distribution of the alkylene compound was measured according to the mass spectrometry gas chromatography analysis of the alkylene compound A described in JP-A-2014-013384. C ₉ H ₁₈ : 0.5% by mass, C ₁₀ H ₂₀ : 4% by mass, C ₁₁ H _22: 20 by mass%, C ₁₂ H _24: 66 by mass%, C ₁₃ H _26: 9 mass%, C ₁₄ H _28: 0.5 wt% (number peak corresponding to alkylene compounds of 9-1 carbon atoms 6).

(Production of alkenyl succinic anhydride)
In a 1 L autoclave manufactured by Nitto Koatsu Co., Ltd., 542.4 g of alkylene compound (a), 157.2 g of maleic anhydride, 0.4 g of antioxidant Chelex-O (Triisooctyl phosphite, manufactured by SC Organic Chemicals, Inc.), polymerization inhibitor And 0.1 g of butylhydroquinone was added thereto, and pressure nitrogen substitution (0.2 MPaG) was repeated three times. After stirring was started at 60 ° C., the temperature was raised to 230 ° C. over 1 hour, and the reaction was carried out for 6 hours. The pressure at the time of reaching the reaction temperature was 0.3 MPaG. After the completion of the reaction, the mixture was cooled to 80 ° C., returned to normal pressure (101.3 kPa), and transferred to a 1 L four-necked flask. The temperature was raised while stirring to 180 ° C., and the remaining alkylene compound was distilled off at 1.3 kPa for 1 hour. Subsequently, after cooling to room temperature (25 ° C.), the pressure was returned to normal pressure (101.3 kPa) to obtain 406.1 g of the target product, alkenyl succinic anhydride. The average molecular weight of the alkenyl succinic anhydride determined from the acid value was 268.

[Production of resin (a) and resin (b)]
Synthesis Examples A1 to A7, A11 to A13 (Production of Resins A-1 to A-7, A-11 to A-13)
The raw material monomer, esterification catalyst, and gallic acid of the polyester resin (segment (A1)) other than trimellitic anhydride shown in the table were converted into a 5-liter volume equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. The mixture was placed in a four-necked flask, heated to 235 ° C. in a nitrogen atmosphere, and then subjected to polycondensation at 235 ° C. for 6 hours. Thereafter, the temperature was lowered to 160 ° C., and a mixture of acrylic acid (amphoteric monomer), a raw material monomer of a vinyl-based resin (segment (A2)), and a polymerization initiator was dropped by a dropping funnel over 1 hour. After dropping, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C, and then the temperature was raised to 200 ° C and the pressure was reduced at 10 kPa for 1 hour. Thereafter, the pressure was released, the temperature was lowered to 180 ° C., trimellitic anhydride shown in the table was added, the temperature was raised from 180 ° C. to 210 ° C. at a rate of 10 ° C./hour, and then the reaction was performed at 210 ° C. for 1 hour. Further, the reaction was carried out at 210 ° C. under a reduced pressure of 10 kPa to the softening point shown in the table to obtain a polyester resin. The physical properties are shown in the table.

Synthesis Example A8 (Production of resin A-8)
The raw material monomer, esterification catalyst and gallic acid of the polyester resin (segment (A1)) other than trimellitic anhydride, adipic acid and fumaric acid shown in the table were converted into a dehydration tube equipped with a nitrogen introduction tube, a stirrer and a thermocouple. The mixture was placed in a equipped 5-liter four-necked flask, heated to 235 ° C. in a nitrogen atmosphere, and then subjected to polycondensation at 235 ° C. for 6 hours. afterwards. The temperature was lowered to 160 ° C., and a mixture of acrylic acid (amphoteric monomer), a raw material monomer of a vinyl-based resin (segment (A2)), and a polymerization initiator was dropped by a dropping funnel over 1 hour. After dropping, the addition polymerization reaction was aged for 1 hour while maintaining the temperature at 160 ° C., then the temperature was raised to 200 ° C., and the pressure was reduced at 10 kPa for 1 hour. After opening the pressure, the temperature was lowered to 180 ° C., and trimellitic anhydride, adipic acid, fumaric acid and a polymerization inhibitor shown in the table were added, and the temperature was raised from 180 ° C. to 210 ° C. at a rate of 10 ° C./hour. Allowed to react for hours. Further, the reaction was carried out at 210 ° C. under a reduced pressure of 10 kPa to the softening point shown in the table to obtain a polyester resin A-8. The physical properties are shown in the table.

Synthesis Examples A9, B5 to B7 (Production of Resins A-9, B-5 to B-7)
The raw material monomer, esterification catalyst and gallic acid of the polyester resin other than trimellitic anhydride shown in the table were put into a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple, and placed under a nitrogen atmosphere. The temperature was raised to 235 ° C., and then polycondensation was performed at 235 ° C. for 6 hours. Thereafter, the temperature was lowered to 210 ° C., trimellitic anhydride was added, and the reaction was performed at 210 ° C. for 1 hour. Then, the reaction was further performed at 210 ° C. under a reduced pressure of 10 kPa to the softening point described in Table 2, and the polyester resin I got The physical properties are shown in the table.

Synthesis Examples A10, B1 to B4, B8 to B9 (Production of Resins A-10, B-1 to B-4, B-8 to B-9)
As shown in the table, the raw material monomer of polyester other than trimellitic anhydride, the esterification catalyst and gallic acid were converted into a nitrogen introduction tube, a dehydration tube equipped with a fractionating tube through which hot water of 98 ° C. was passed, a stirrer, and a thermocouple. The mixture was placed in a equipped 5-liter four-necked flask, kept at 180 ° C. for 1 hour in a nitrogen atmosphere, heated from 180 ° C. to 210 ° C. at 10 ° C./hour, and then subjected to polycondensation at 210 ° C. for 10 hours. . Thereafter, trimellitic anhydride was added and reacted at 210 ° C. for 1 hour, and further reacted at 210 ° C. under reduced pressure of 10 kPa to the softening point shown in the table to obtain a polyester resin. The physical properties are shown in the table.

[Production of aqueous dispersion of resin particles (X) containing resin (a) for core]
Production Example A1
600 g of methyl ethyl ketone was put into a 5 L container equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, and 150 g of the polyester resin A-1 produced in Synthesis Example A1 was added at 60 ° C. Was dissolved. To the obtained solution, a 20% by mass aqueous ammonia solution (pKa: 9.3) was added so as to have a degree of neutralization of 100 mol% with respect to the acid value of the resin, followed by stirring for 30 minutes to obtain a mixture. . Subsequently, 675 g of ion-exchanged water was added over 77 minutes. Then, methyl ethyl ketone was distilled off under reduced pressure at a temperature of 50 ° C. or less while stirring at 250 r / min, and then anionic surfactant “Emal E27C” (sodium polyoxyethylene lauryl ether sulfate, manufactured by Kao Corporation, (Solid content 28% by mass) were mixed and completely dissolved. Thereafter, the solids concentration of the aqueous dispersion was measured, and the solids concentration of the aqueous dispersion was adjusted to 20% by mass by adding ion-exchanged water.

Production Examples A2 to A13
In Production Example A1, an aqueous dispersion of resin particles was obtained in the same manner as in Production Example A1, except that the polyester resin used was changed to polyesters A-2 to A-13 obtained in Synthesis Examples A2 to A13. .

[Production of aqueous dispersion of resin particles (Y) containing resin (b) for shell]
Production Examples B1 to B9
In Production Example A1, an aqueous dispersion of resin particles for shell was prepared in the same manner as in Production Example A1, except that the polyester resin used was changed to polyesters B-1 to B-9 obtained in Synthesis Examples B1 to B9. Obtained.

[Production of release agent dispersion]
Production Example W1
50 g of paraffin wax (trade name: HNP0190, manufactured by Nippon Seiro Co., Ltd., melting point: 85 ° C.), 5 g of cationic surfactant (trade name: Sanisol B50, manufactured by Kao Corporation) and 200 g of ion-exchanged water are heated to 95 ° C. Then, after the paraffin wax was dispersed by using a homogenizer, the dispersion was performed by a pressure discharge type homogenizer to obtain a release agent dispersion liquid W1 containing release agent particles having a solid content concentration of 20% by mass. The volume median particle size (D ₅₀ ) of the release agent particles was 550 nm.

[Production of charge control agent dispersion]
Production example CH1
A salicylic acid-based compound “Bontron E-84” (manufactured by Orient Chemical Industries, Ltd.) as a charge control agent (50 g), “Emulgen 150” (Kao Corporation) as a nonionic surfactant, 5 g, and 200 g of ion-exchanged water were mixed. Using a glass bead, the mixture was dispersed at 25 ° C. for 10 minutes using a sand grinder to obtain a charge control agent dispersion containing charge control agent particles. The volume-average particle diameter (D ₅₀ ) of the charge control agent particles having a solid content of 20% by mass was 500 nm.

[Production of colorant dispersion]
Production Example P1
In a 1-liter beaker, 116.2 g of a copper phthalocyanine pigment “ECB-301” (manufactured by Dainichi Seika Kogyo Co., Ltd.) and an anionic surfactant “Neoperex (registered trademark) G-15” (manufactured by Kao Corporation, 154.9 g of a 15% by mass aqueous solution of sodium dodecylbenzenesulfonate) and 340 g of deionized water were mixed and dispersed at room temperature for 3 hours using a homogenizer, and then deionized water was adjusted to a solid concentration of 24% by mass. Was added to obtain a colorant dispersion P1. The volume median particle size (D ₅₀ ) of the colorant particles in the dispersion was 118 nm.

[Production of toner for developing electrostatic images]
Example 1
300 g of an aqueous dispersion of core resin particles produced in Production Example A1, 15 g of a release agent dispersion produced in Production Example W1, 8 g of a colorant dispersion produced in Production Example P1, and a charge control agent produced in Production Example CH1 2 g of the dispersion liquid is placed in a 3 L container, and 150 g of a 0.1 mass% calcium chloride aqueous solution is dropped at 30 ° C. over 30 minutes at 100 ° C./min (peripheral speed: 31 m / min) with an anchor-type stirrer. did. Thereafter, the temperature was raised to 50 ° C. while stirring. After 3 hours, aggregated particles (I) having a volume median particle size (D ₅₀ ) of 5 μm were obtained. Thereafter, 90 g of an aqueous dispersion of the resin particles for shell prepared in Production Example B1 was added, and the mixture was stirred and dispersed to obtain aggregated particles (II) obtained by aggregating the resin particles for shell with aggregated particles (I). . Then, a diluent obtained by diluting 4.2 g of an anionic surfactant “Emal E27C” (manufactured by Kao Corporation, solid content: 28% by mass) with 37 g of deionized water in a dispersion of the aggregated particles (II) was used as a coagulation terminator. Was added to obtain an aggregate. Next, the temperature was raised to 80 ° C., and after maintaining at 80 ° C. for 1 hour from the time when the temperature reached 80 ° C., the heating was terminated. After the core-shell particles are formed, the mixture is gradually cooled to 20 ° C., filtered through a 150-mesh (mesh opening: 150 μm) wire mesh, suction-filtered, sufficiently washed with ion-exchanged water, and dried. Thus, core-shell particles were obtained. The volume-median particle size (D ₅₀ ) of the obtained core-shell particles was 5.1 μm.
To 100 parts by mass of the core-shell particles, 0.5 part by mass of an external additive (hydrophobic silica, manufactured by Nippon Aerosil Co., Ltd., trade name: Aerosil R-972, number average particle size: 16 nm) was added, and a Henschel mixer (Japan) was added. The mixture was mixed at 3600 r / min (peripheral speed: 31.7 m / sec) for 5 minutes with an external additive treatment to obtain a toner (volume median particle diameter D ₅₀ = 5.1 μm). . The evaluation results of the obtained toner are shown in the table.

Examples 2 to 18 and Comparative Examples 1 to 5
A toner was prepared in the same manner as in Example 1 except that the type and amount of the aqueous dispersion of resin particles used in Example 1 were changed to the types and amounts of the aqueous dispersion of resin particles shown in Table 4. Got. The evaluation results of the obtained toner are shown in the table.

Comparative Example 6
A toner was obtained in the same manner as in Example 1 except that the releasing agent dispersion liquid was not used. The evaluation results of the obtained toner are shown in the table.

  From Table 4, it can be seen that the toners of Examples 1 to 18 are superior to the toners of Comparative Examples 1 to 6 in low-temperature fixability, heat-resistant storage stability and durability.

Claims (9)

A method for producing a toner, comprising the following steps 1 to 5, wherein the difference [BA] of the following A with respect to the following B is 20 mol% or more.
Step 1: a step of obtaining a resin for core (a) through a reaction between an alcohol component, a carboxylic acid component, and optionally polyethylene terephthalate.
Step 2: a step of reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate to obtain a shell resin (b).
Step 3: a step of obtaining aggregated particles (I) from the aqueous dispersion containing the core resin (a) and the release agent.
Step 4: a step of adding the shell resin (b) to the aggregated particles (I) obtained in Step 3 to obtain a dispersion of the aggregated particles (II).
Step 5: a step of fusing the aggregated particles (II) obtained in Step 4 to obtain core-shell particles.
A: A (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the mole number of the alcohol component in step 1 and the mole number of ethylene glycol units in polyethylene terephthalate. Amount.
B: B (mol%) is the blending of polyethylene terephthalate in terms of the molar ratio of polyethylene terephthalate-derived ethylene glycol units to the sum of the number of moles of the alcohol component in step 2 and the number of moles of ethylene glycol units in polyethylene terephthalate. Amount.   2. The process according to claim 1, wherein the amount of the shell resin (b) is 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the core resin (a) contained in the aggregated particles (I) in step 4. The method for producing a toner for developing electrostatic images according to the above.   3. The method for producing a toner for developing electrostatic images according to claim 1, wherein the blending amount B of the polyethylene terephthalate in the step 2 is 20 mol% or more and 80 mol% or less.   The method for producing a toner for developing electrostatic images according to any one of claims 1 to 3, wherein the IV value of the polyethylene terephthalate compounded in the step 2 is 0.4 or more and 0.75 or less.   The aliphatic diol having 2 or more and 6 or less carbon atoms is 40 mol% or more and 80 mol% or less based on the total amount of the alcohol component and the ethylene glycol derived from polyethylene terephthalate, which are blended in step 2. A method for producing a toner for developing an electrostatic image according to the above item (1).   The method for producing an electrostatic image developing toner according to any one of claims 1 to 5, wherein the blending amount A of polyethylene terephthalate in step 1 is 0 mol% or more and 40 mol% or less.   The method for producing an electrostatic image developing toner according to any one of claims 1 to 6, wherein the IV value of polyethylene terephthalate in step 1 is 0.40 or more and 0.75 or less.   The electrostatic charge according to any one of claims 1 to 7, wherein in step 1, succinic acid or an anhydride thereof substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms is further blended. A method for producing an image developing toner.   9. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the alkylene oxide adduct of bisphenol A in the alcohol component in step 1 is at least 50 mol%.