JP7198640B2 - Toner for electrostatic charge image development - Google Patents

Description

The present invention relates to a toner for electrostatic charge image development.

In recent years, in the field of electrophotography, along with the development of electrophotographic systems, there has been a demand for the development of electrostatic charge image developing toners (hereinafter also referred to simply as "toners") that are compatible with higher image quality and higher speeds. For example, toners are required to have excellent low-temperature fixability in order to cope with high-speed and energy-saving printing devices such as printers and copiers. In addition, in order to cope with high image quality, as a method of obtaining a toner with a narrow particle size distribution and a small particle size, the aggregation fusion method ( Toner is produced by an emulsion aggregation method, an aggregation coalescence method). In particular, a toner containing core-shell type toner particles has been proposed in order to improve thermal properties such as low-temperature fixability.
For example, Patent Document 1 discloses a crystalline composite resin (CH) containing a polycondensation resin component (CH-1) and a styrene resin component (CH-2), and an amorphous resin (A). In the binder resin composition for an electrophotographic toner, the polycondensation resin component (CH-1) contains an alcohol component containing 80 mol % to 100 mol % of an aliphatic diol having 2 to 4 carbon atoms, and and a carboxylic acid component containing 80 mol % to 100 mol % of an aliphatic dicarboxylic acid compound having 12 to 14 carbon atoms, and a binder resin composition for an electrophotographic toner obtained by polycondensation. Are listed. It is described that the electrophotographic toner is excellent in low-temperature fixability, hot offset resistance, charging stability, and heat-resistant storage stability under high humidity.

JP 2016-218272 A

As described above, toners containing core-shell type toner particles have been proposed in order to improve thermal properties such as low-temperature fixability and charging stability. Therefore, there is a demand for a toner that is excellent in image density of printed matter.
Further, in the electrophotographic toner described in Japanese Patent Laid-Open No. 2002-200001, there is also a demand for an improvement in the image density of printed matter.
Accordingly, the present invention relates to a toner for electrostatic charge image development which is excellent in low-temperature fixability and charge stability, and which is excellent in image density of printed matter.

The present inventors found that in toner particles having a core-shell structure, the core contains a styrene-based resin (AS) and a specific crystalline composite resin (CH), and the shell contains a specific amorphous composite resin (AH ), it is possible to obtain an electrostatic charge image developing toner capable of solving the above problems.
Specifically, the present invention relates to the following [1].
[1] A toner for electrostatic image development containing toner particles having a core-shell structure having a core and a shell,
The core comprises a styrene resin (AS), an alcohol component (C-al) containing 95 to 100 mol% of 1,4-butanediol, and 95 of an aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms. A polyester segment (CH-1) which is a polycondensation portion with a carboxylic acid component (C-ac) containing mol% or more and 100 mol% or less, and an addition polymerization portion of a monomer component (Ch-st) containing a styrenic compound and a crystalline composite resin (CH) containing a certain vinyl resin segment (CH-2),
The shell is a polycondensation portion of an alcohol component (A-al) containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component (A-ac) containing 5 mol% or more and 40 mol% or less of succinic acid. Segment (AH-1), and an amorphous composite resin (AH) containing a vinyl resin segment (AH-2) which is an addition polymerization portion of a monomer component (A-st) containing a styrene compound, Toner for electrostatic charge image development.

According to the present invention, it is possible to provide an electrostatic charge image developing toner which is excellent in low-temperature fixability and charge stability, and which is excellent in image density of printed matter.

[Electrostatic charge image developing toner]
As described in [1] above, the toner for electrostatic charge image development of the present invention contains toner particles having a core-shell structure having a core and a shell (hereinafter also simply referred to as "toner particles"), and has low-temperature fixability and chargeability. It is excellent in stability, and is also excellent in image density (hereinafter also simply referred to as "image density") of printed matter.
Although the reason why such an effect is obtained is not clear, it is considered as follows.
In order to obtain a toner having a better image density, it is considered necessary to control the aggregation speed of particles when producing toner particles having a core-shell structure to sharpen the particle size distribution of the toner. When producing toner particles having a core-shell structure, the core resin particles are first aggregated in an aqueous medium to prepare core aggregated particles, then the shell resin particles are added, and part of the surface of the core aggregated particles is formed. Alternatively, agglomerated particles having a core-shell structure are produced by covering the whole with the shell resin. At this time, the toner for electrostatic charge image development of the present invention contains a certain amount or more of a structure derived from succinic acid with a high pKa value (low acidity) at the end of the amorphous composite resin (AH) used for the shell. As a result, the stability of the shell particles is increased, so that the aggregation speed of the shell containing the amorphous composite resin (AH) is slowed down, making it easier to control the particle size. As a result, the shell particles can be uniformly adhered to the core particles, so that the particle size distribution of the toner can be sharpened. As a result, it is believed that the toner of the present invention has improved image density.
In addition, since the crystalline composite resin (CH) used for the core has a vinyl resin segment (CH-2) which is an addition polymerization portion of a monomer component (Ch-st) containing a styrene compound, It is considered that the compatibility with the styrene-based resin (AS), which is another resin component in the core, was improved, and the exposure of the crystalline composite resin (CH) in the core to the toner surface was reduced. As a result, it is believed that the toner of the present invention has improved charging stability.
In addition, since the structure derived from succinic acid in the amorphous composite resin (AH) partially forms a microcrystalline packing state, compatibility with the core resin is prevented during storage of the toner. On the other hand, at high temperature during toner fixing, the packing state in the amorphous composite resin (AH) is released, improving the compatibility with the core resin and exhibiting good low-temperature fixability. receive.

Definitions of various terms used in this specification are shown below.
Whether a resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum endothermic peak temperature (softening point (°C)/maximum endothermic peak temperature (°C)) in the measurement method described in the Examples below. A crystalline resin has a crystallinity index of 0.6 or more and 1.4 or less. Amorphous resins are those having a crystallinity index of less than 0.6 or greater than 1.4. The crystallinity index can be appropriately adjusted depending on the types and ratios of raw material components of the resin, and manufacturing conditions such as reaction temperature, reaction time, and cooling rate.
The "binder resin" means a resin component contained in the toner including styrene resin (AS), crystalline composite resin (CH), and amorphous composite resin (AH).
One or more selected from styrene and styrene derivatives are referred to as "styrenic compounds".
Carboxylic acid components, which are raw materials for resins, include not only these compounds, but also anhydrides that decompose during the reaction to generate acids, and alkyl esters of each carboxylic acid (where the number of carbon atoms in the alkyl group is 1 or more and 3 or less). included.
"Alkyl (meth)acrylate" means both alkyl acrylate and alkyl methacrylate. Similarly, "(meth)acrylate" means both acrylate and methacrylate, and "(meth)acryloyl group" means both acryloyl group and methacryloyl group.
"Volume median particle size D ₅₀ " is the particle size at which the cumulative volume frequency calculated by volume fraction is 50% calculated from the smaller particle size. It is a particle size measured by the measuring method described in .

<Toner particles>
Core-shell toner particles have a core and a shell. The shell covers part or all of the surface of the core, preferably the entire surface of the core.

(Styrene-based resin (AS))
Examples of the styrene resin (AS) contained in the core include polystyrene, styrene derivative polymers, styrene-acrylic copolymers, and the like. At least one selected from copolymers is preferred, at least one selected from polystyrene and styrene-acrylic copolymers is more preferred, and styrene-acrylic copolymers are even more preferred.

From the viewpoint of low temperature fixability, the monomer component (AS-st) of the styrene resin (AS) preferably contains at least a styrene compound, more preferably at least styrene. ) acrylates.
The styrene derivative is preferably one or more selected from methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid and salts thereof.
In the monomer component (AS-st), the content of the styrene compound is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and even more preferably, from the viewpoint of low-temperature fixability. is 70% by mass or more, more preferably 75% by mass or more, and from the same viewpoint, preferably 100% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, and even more preferably is 85% by mass or less. The monomer component (AS-st) does not contain a polymerization initiator.

Compounds other than styrenic compounds that may be contained in the monomer component (AS-st) include alkyl (meth)acrylates; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; vinyl esters such as vinyl acetate and vinyl propionate; ethylenic monocarboxylic acid esters such as dimethylaminoethyl (meth)acrylate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; Examples include N-vinyl compounds such as pyrrolidone. Among these, alkyl (meth)acrylates are preferred from the viewpoint of low-temperature fixability.

Alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso or tertiary) butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, (iso)behenyl (meth)acrylate and the like. Among these, n-butyl acrylate is preferred.
"(iso or tertiary)" and "(iso)" mean both when these prefixes are present and when they are not present, and when these prefixes are not present, normal is indicated.
The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate that the monomer component (AS-st) may contain is preferably 1 or more, more preferably 2 or more, and still more preferably 3 or more, from the viewpoint of low-temperature fixability, and , preferably 12 or less, more preferably 10 or less, even more preferably 8 or less, and even more preferably 6 or less.
Here, "the number of carbon atoms in the alkyl group of the alkyl(meth)acrylate" means the number of carbon atoms derived from the alcohol component constituting the alkyl(meth)acrylate.
The content of the alkyl (meth)acrylate in the monomer component (AS-st) is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more, from the viewpoint of low-temperature fixability. , and preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less.

The styrenic resin (AS) can be produced by subjecting the monomer component (AS-st) to an addition polymerization reaction. The temperature of the addition polymerization reaction is preferably 120° C. or higher, more preferably 150° C. or higher, and preferably 230° C. or lower, more preferably 220° C. or lower, from the viewpoint of reactivity.

The softening point of the styrene-based resin (AS) is preferably 90° C. or higher, more preferably 105° C. or higher, and still more preferably 115° C. or higher from the viewpoint of storage stability. It is 150° C. or lower, more preferably 135° C. or lower, still more preferably 125° C. or lower.
The glass transition temperature of the styrene-based resin (AS) is preferably 30° C. or higher, more preferably 40° C. or higher, and still more preferably 50° C. or higher from the viewpoint of storage stability. is 90° C. or lower, more preferably 70° C. or lower, still more preferably 60° C. or lower.
The softening point and glass transition temperature of the styrenic resin (AS) can be appropriately adjusted depending on the type and ratio of the monomer component (AS-st) and production conditions such as reaction temperature, reaction time and cooling rate.

(Crystalline composite resin (CH))
The crystalline resin (CH) contained in the core is an alcohol component (C-al) containing 95 to 100 mol% of 1,4-butanediol and 95 of an aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms. A polyester segment (CH-1) which is a polycondensation portion with a carboxylic acid component (C-ac) containing mol% or more and 100 mol% or less, and an addition polymerization portion of a monomer component (Ch-st) containing a styrenic compound Contains a certain vinyl resin segment (CH-2).
The crystalline composite resin (CH) preferably has a crystallinity index of 0.7 or more and 1.2 or less, more preferably 0.9 or more and 1.2 or less.

The crystalline composite resin (CH) comprises a polyester segment (CH-1), a vinyl resin segment (CH-2), and a polyester segment (CH -1) and a structural portion derived from a bi-reactive monomer capable of reacting with both the vinyl resin segment (CH-2).
In the crystalline composite resin (CH), the mass ratio of the polyester segment (CH-1) and the vinyl resin segment (CH-2) [segment (CH-1)/segment (CH-2)] is the low-temperature fixability. And from the viewpoint of charging stability, it is preferably 60/40 or more, more preferably 70/30 or more, still more preferably 80/20 or more, still more preferably 85/15 or more, and even more preferably 90/10 or more. , and preferably 98/2 or less, more preferably 96/4 or less, and even more preferably 95/5 or less.
In the calculation of the mass ratio [segment (CH-1)/segment (CH-2)], the mass of the polyester segment (CH-1) is calculated from the total amount of raw material components of the polyester segment (CH-1), The value obtained by removing the amount of dehydration during the condensation reaction is used, and the mass of the vinyl resin segment (CH-2) is the monomer component (Ch-st) of the vinyl resin segment (CH-2) and the polymerization initiator. Use the total amount. Also, the bi-reactive monomer used if necessary is calculated as the mass of the polyester segment (CH-1). The mass ratio [segment (AH-1) / segment (AH-2)] of the polyester segment (AH-1) and the vinyl resin segment (AH-2) in the amorphous composite resin (AH) described later is also the same. calculated using the method of

[Polyester segment (CH-1)]
The mass ratio [(CH-1)/(CH)] of the polyester segment (CH-1) in the crystalline composite resin (CH) is preferably 60/100 or more from the viewpoint of low-temperature fixability and charging stability. More preferably 70/100 or more, still more preferably 80/100 or more, still more preferably 85/100 or more, and from the same viewpoint, preferably 98/100 or less, more preferably 96/100 or less, and further Preferably it is 95/100 or less.

{Alcohol component (C-al)}
The content of 1,4-butanediol in the alcohol component (C-al) is 95 mol % or more and 100 mol % or less, preferably 96 mol %, from the viewpoint of low-temperature fixability, charging stability and image density. Above, it is more preferably 98 mol % or more, still more preferably 99 mol % or more, and still more preferably 100 mol %.
Alcohols other than 1,4-butanediol include aliphatic diols other than 1,4-butanediol, aromatic diols, alicyclic diols, trihydric or higher polyhydric alcohols, or those having 2 or more carbon atoms. 4 or less alkylene oxide (average addition mole number 1 or more and 16 or less) adducts, and the like.

{Carboxylic acid component (C-ac)}
In the carboxylic acid component (C-ac), the content of the aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms is 95 mol% or more and 100 mol% or less, preferably 96 mol%, from the viewpoint of low temperature fixability. Above, more preferably 98 mol % or more, still more preferably 99 mol % or more, and even more preferably 100 mol %.

The aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms is preferably a linear aliphatic dicarboxylic acid compound, more preferably an α,ω-linear aliphatic dicarboxylic acid compound, from the viewpoint of improving low-temperature fixability.
The number of carbon atoms in the dicarboxylic acid compound is 12 or more, preferably 14 or more, from the viewpoint of further improving image density, and is 16 or less, preferably 14, from the viewpoint of low-temperature fixability. Here, the "carbon number of the dicarboxylic acid compound" is a number including the carbon number of the carboxy group in the carbon number of the linear or branched hydrocarbon group, and the dicarboxylic acid compound is an alkyl ester of dicarboxylic acid. In the case of , the number of carbon atoms in the alkyl group is not included.
Examples of the α,ω-linear aliphatic dicarboxylic acid compounds include dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, and alkyl esters thereof having 1 to 3 carbon atoms. mentioned. Among these, one or more selected from dodecanedioic acid and tetradecanedioic acid is preferable from the viewpoint of low-temperature fixability, and tetradecanedioic acid is more preferable from the viewpoint of further improving image density.

The carboxylic acid component (C-ac) may contain a carboxylic acid other than the aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms, for example, an aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms. Dicarboxylic acid compounds other than the above, aromatic dicarboxylic acid compounds, trivalent or higher polyvalent carboxylic acid compounds, and the like.

The equivalent ratio (COOH group/OH group) of the carboxylic acid component (C-ac) to the alcohol component (C-al) is preferably 0.7 or more, more preferably 0, from the viewpoint of low-temperature fixability and charge stability. 0.8 or more, more preferably 0.9 or more, and preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less.
From the viewpoint of adjusting physical properties, the alcohol component (C-al) may appropriately contain a monohydric alcohol, and the carboxylic acid component (C-ac) may suitably contain a monovalent carboxylic acid compound. may be

[Vinyl resin segment (CH-2)]
The mass ratio [(CH-2)/(CH)] of the vinyl resin segment (CH-2) in the crystalline composite resin (CH) is preferably 2/100 from the viewpoint of low-temperature fixability and charge stability. above, more preferably 3/100 or more, more preferably 4/100 or more, and from the same viewpoint, preferably 40/100 or less, more preferably 20/100 or less, still more preferably 10/100 or less, More preferably 8/100 or less, still more preferably 6/100 or less.

Examples of the monomer component (Ch-st) of the vinyl resin segment (CH-2) include those similar to the monomer components of the styrene resin (AS) described above in the section of the styrene resin (AS). From the viewpoint of fixability and charge stability, it preferably contains at least a styrene compound, more preferably contains at least styrene, and still more preferably contains both styrene and an alkyl (meth)acrylate.
In the monomer component (Ch-st), the content of the styrene compound is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and even more preferably, from the viewpoint of low-temperature fixability. is 70% by mass or more, more preferably 75% by mass or more, and from the same viewpoint, preferably 100% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, and even more preferably is 85% by mass or less.

Examples of the alkyl (meth)acrylate that the monomer component (Ch-st) may contain include the same alkyl (meth)acrylates that the monomer component (AS-st) of the styrene resin (AS) may contain. Among these, 2-ethylhexyl acrylate and/or butyl acrylate are used from the viewpoint of improving low-temperature fixability by introducing an alkyl (meth)acrylate into the vinyl resin segment (CH-2) to lower the glass transition temperature. is preferred, and 2-ethylhexyl acrylate is more preferred.
In the monomer component (Ch-st), the content of alkyl (meth)acrylate is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more, from the viewpoint of low-temperature fixability. , and preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less.

[Double-reactive monomer]
The crystalline composite resin (CH) preferably further contains a structural unit derived from a bireactive monomer. The “structural unit derived from a bireactive monomer” means a unit obtained by reacting a functional group and an addition polymerizable group of a bireactive monomer.
The bi-reactive monomer means, for example, in the molecule, the functional group used for reaction with the polyester segment (CH-1) and the addition polymerizable monomer used for reaction with the vinyl resin segment (CH-2) and a compound having a group. By using such a bireactive monomer, low-temperature fixability, charging stability and image density can be further improved.
As the functional group, for example, one or more selected from hydroxyl group, carboxy group, epoxy group, primary amino group and secondary amino group used for reaction with the polyester segment (CH-1), preferably hydroxyl group and/or a carboxy group, more preferably a carboxy group.
Examples of the addition polymerizable group include carbon-carbon unsaturated bonds such as ethylenically unsaturated bonds used for reaction with the vinyl resin segment (CH-2).
As the bi-reactive monomer, one or more selected from acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride is preferable from the viewpoint of further improving low-temperature fixability, charging stability and image density. , methacrylic acid and fumaric acid, more preferably one or more selected from acrylic acid and methacrylic acid, and still more preferably acrylic acid.
However, when used together with a polymerization inhibitor, a carboxylic acid compound having a carbon-carbon unsaturated bond such as an ethylenically unsaturated bond such as fumaric acid functions as a raw material component for the polyester segment (CH-1). In this case, fumaric acid or the like is not a bireactive monomer, but a raw material component of the polyester segment (CH-1).

From the viewpoint of further improving low-temperature fixability, charging stability and image density, the content of the bi-reactive monomer is preferably at least 1 mol part, more preferably at least 1 mol part, per 100 mol parts of the alcohol component (C-al). 1.5 mol parts or more, more preferably 2 mol parts or more, and from the viewpoint of low-temperature fixability, preferably 30 mol parts or less, more preferably 20 mol parts or less, still more preferably 10 mol parts or less, and more It is more preferably 5 mol parts or less, even more preferably 4 mol parts or less, still more preferably 3 mol parts or less.

[Method for producing crystalline composite resin (CH)]
The crystalline composite resin (CH) can be produced, for example, by any one of the following methods (1) to (3). From the viewpoint of reactivity, the dual-reactive monomer is preferably supplied to the reaction system together with the monomer component (Ch-st), which is the raw material component of the vinyl resin segment (CH-2). From the same viewpoint as above, a catalyst such as an esterification catalyst and an esterification co-catalyst may be used, and a polymerization initiator and a polymerization inhibitor may also be used.

(1) After the step (X) of the polycondensation reaction by the alcohol component (C-al) and the carboxylic acid component (C-ac) which are raw materials of the polyester segment (CH-1), the vinyl resin segment (CH- A method of carrying out the step (Y) of the addition polymerization reaction using the monomer component (Ch-st) which is the raw material component of 2) and, if necessary, the bi-reactive monomer.
(2) After the addition polymerization reaction step (Y) of the monomer component (Ch-st) which is the raw material component of the vinyl resin segment (CH-2) and the bi-reactive monomer, the raw material of the polyester segment (CH-1) A method of carrying out the step (X) of the polycondensation reaction with the alcohol component (C-al) and the carboxylic acid component (C-ac) as components.
(3) Step (X) of polycondensation reaction by alcohol component (C-al) and carboxylic acid component (C-ac) which are raw materials of polyester segment (CH-1), and vinyl resin segment (CH-2 ) and the step (Y) of the addition polymerization reaction by the monomer component (Ch-st), which is the raw material component of () and the bi-reactive monomer, proceed in parallel.

Among the methods (1) to (3), the crystalline composite resin (CH) is preferably produced by the method (1), more preferably by a method comprising the following steps I to III. .
Step I: a step of polycondensing a part of the alcohol component (C-al) and/or the carboxylic acid component (C-ac), which are raw materials of the polyester segment (CH-1) Step II: obtained in step I Step of addition polymerization of the monomer component (Ch-st) of the vinyl resin segment (CH-2) in the presence of the polycondensate Step III: In the presence of the reactant obtained in Step II, the remaining polyester segment ( A step of polycondensing the alcohol component (C-al) and/or the carboxylic acid component (C-ac), which are the raw material components of CH-1). It is preferably used together with the monomer component (Ch-st) of the segment (CH-2).
By performing the above steps I to III, the polyester segment (CH-1) and the vinyl resin segment (CH-2) in the crystalline composite resin (CH) are in a moderately dispersed state, and the polyester segment (CH-1 ) can be enhanced, and low-temperature fixability, charging stability and image density can be further improved.

From the viewpoint of reactivity, the temperature of the polycondensation reaction in step I is preferably 130° C. or higher, and preferably 230° C. or lower, more preferably 200° C. or lower, and even more preferably 180° C. or lower.
The temperature of the addition polymerization reaction in step II is preferably 130° C. or higher, and preferably 200° C. or lower, more preferably 180° C. or lower, from the viewpoint of reactivity.
The temperature of the polycondensation reaction in Step III is preferably 120° C. or higher, more preferably 130° C. or higher, and preferably 230° C. or lower, more preferably 220° C. or lower, from the viewpoint of reactivity.

Examples of the esterification catalyst include titanium compounds and tin(II) compounds having no Sn—C bond, and these can be used alone or in combination of two or more.
As the titanium compound, a titanium compound having a Ti—O bond is preferable, and a compound having an alkoxy group, an alkenyloxy group, or an acyloxy group having a total carbon number of 1 to 28 is more preferable.
Examples of tin (II) compounds having no Sn—C bond include tin (II) compounds having an Sn—O bond, tin (II) compounds having an Sn—X (X represents a halogen atom) bond, and the like. Among them, a tin (II) compound having an Sn—O bond is preferred, and among them, di(2-ethylhexanoic acid) is used from the viewpoint of reactivity, molecular weight adjustment, and physical property adjustment of the crystalline composite resin (CH). Tin(II) is more preferred.
When an esterification catalyst is used in the polycondensation reaction, the amount of the alcohol component (C-al) and the carboxylic acid component (C It is preferably 0.1 parts by mass or more and preferably 1.5 parts by mass or less with respect to 100 parts by mass as the total amount of -ac).

Pyrogallol compounds are preferred as esterification co-catalysts. The pyrogallol compound has a benzene ring in which three adjacent hydrogen atoms are substituted with hydroxyl groups, and pyrogallol, gallic acid, gallic acid ester, 2,3,4-trihydroxybenzophenone, 2,2' , 3,4-tetrahydroxybenzophenone and other benzophenone derivatives, epigallocatechin, epigallocatechin gallate and other catechin derivatives, etc. Gallic acid is preferred from the viewpoint of reactivity.

The softening point of the crystalline composite resin (CH) is preferably 60° C. or higher, more preferably 70° C. or higher, even more preferably 80° C. or higher, and even more preferably 85° C. or higher, from the viewpoint of storage stability, and From the viewpoint of low-temperature fixability, the temperature is preferably 120° C. or lower, more preferably 100° C. or lower, still more preferably 90° C. or lower, and even more preferably 88° C. or lower.
The melting point of the crystalline composite resin (CH) is preferably 50° C. or higher, more preferably 60° C. or higher, still more preferably 70° C. or higher, and even more preferably 75° C. or higher, from the viewpoint of storage stability. From the viewpoint of fixability, the temperature is preferably 110° C. or lower, more preferably 90° C. or lower, and even more preferably 80° C. or lower.
The acid value of the crystalline composite resin (CH) is preferably 3 mgKOH/g or more, more preferably 10 mgKOH/g or more, still more preferably 15 mgKOH/g or more, still more preferably 15 mgKOH/g or more, from the viewpoint of low-temperature fixability and charge stability. 20 mgKOH/g or more, and from the same viewpoint, preferably 40 mgKOH/g or less, more preferably 35 mgKOH/g or less, even more preferably 30 mgKOH/g or less, and even more preferably 25 mgKOH/g or less.
The hydroxyl value of the crystalline composite resin (CH) is preferably 1 mgKOH/g or more, more preferably 2 mgKOH/g or more, and still more preferably 3 mgKOH/g or more from the same viewpoint as described above. , preferably 30 mgKOH/g or less, more preferably 20 mgKOH/g or less, even more preferably 10 mgKOH/g or less, still more preferably 5 mgKOH/g or less.
The softening point, melting point, acid value and hydroxyl value of the crystalline composite resin (CH) can be appropriately adjusted depending on the types and ratios of raw material components and production conditions such as reaction temperature, reaction time and cooling rate. The softening point, melting point, acid value and hydroxyl value are determined by the methods described in Examples.

In addition to the styrenic resin (AS) and the crystalline composite resin (CH), the core may include known resins used in toners, such as styrenic resins (AS) and Polyester, styrene-acrylic copolymer, epoxy, polycarbonate, polyurethane, etc., other than the crystalline composite resin (CH) may be contained.
The total amount of the styrenic resin (AS) and the crystalline composite resin (CH) in the binder resin constituting the core is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass. More preferably, it is 98% by mass or more, preferably 100% by mass or less, and more preferably 100% by mass.
Further, the mass ratio [(CH)/(AS)] of the amount of the styrene resin (AS) in the core and the amount of the crystalline composite resin (CH) is determined from the viewpoint of low-temperature fixability and charging stability. Therefore, it is preferably 5/95 or more, more preferably 10/90 or more, still more preferably 15/85 or more, and from the same viewpoint, preferably 50/50 or less, more preferably 40/60 or less, and further It is preferably 30/70 or less, more preferably 20/80 or less.

(Amorphous composite resin (AH))
The amorphous composite resin (AH) contained in the shell includes an alcohol component (A-al) containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component (A- ac), a polyester segment (AH-1), which is a polycondensation portion, and a vinyl resin segment (AH-2), which is an addition polymerization portion of a monomer component (A-st) containing a styrene compound.
The amorphous composite resin (AH) is a resin having a crystallinity index of more than 1.4 or less than 0.6, preferably more than 1.5 or less than 0.5, more preferably 1 0.6 or more and 0.5 or less.
In the amorphous composite resin (AH), the mass ratio of the polyester segment (AH-1) and the vinyl resin segment (AH-2) [segment (AH-1)/segment (AH-2)] From the viewpoint of properties, charging stability and image density, the ratio is preferably 60/40 or more, more preferably 70/30 or more, still more preferably 75/25 or more, and preferably 95/5 or less, more preferably 90. /10 or less, more preferably 85/15 or less.

[Polyester segment (AH-1)]
The mass ratio [(AH-1)/(AH)] of the polyester segment (AH-1) in the amorphous composite resin (AH) is preferably 60 from the viewpoint of low-temperature fixability, charging stability and image density. /100 or more, more preferably 70/100 or more, still more preferably 75/100 or more, and from the same viewpoint, preferably 95/100 or less, more preferably 90/100 or less, still more preferably 85/100 It is below.

{Alcohol component (A-al)}
The alcohol component (A-al) contains an alkylene oxide adduct of bisphenol A, preferably an alkylene oxide of bisphenol A represented by the following general formula (I), from the viewpoint of low-temperature fixability, charging stability and image density. Contains oxide adducts.

(In general formula (I), OR ¹ and R ² O are each independently an alkyleneoxy group having 1 to 4 carbon atoms. x and y are the average number of moles of alkylene oxide added, is a positive number, the value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 5 or less, even more preferably 4 or less Also, x OR ¹ and y R ² O may be independently the same or different.)

The alkylene oxide adduct of bisphenol A represented by the general formula (I) is preferably a propylene oxide adduct of bisphenol A (hereinafter referred to as "BPA-PO ”), an ethylene oxide adduct of bisphenol A (hereinafter also referred to as “BPA-EO”), and the like.
The alcohol component (A-al) preferably contains at least BPA-PO, more preferably both BPA-PO and BPA-EO.

When the alcohol component (A-al) contains BPA-PO, the content of BPA-PO in the alcohol component (A-al) is preferably 70 mol% or more from the same viewpoint as above, and It is preferably 100 mol % or less, more preferably 90 mol % or less.
When the alcohol component (A-al) contains BPA-EO, the content of BPA-EO in the alcohol component (A-al) is preferably 10 mol% or more, more preferably 15 mol%, from the same viewpoint as above. mol % or more, preferably 30 mol % or less, more preferably 25 mol % or less.
The content of the alkylene oxide adduct of bisphenol A in the alcohol component (A-al) is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol%, from the same viewpoint as described above. More preferably, it is 90 mol % or more, preferably 100 mol % or less, and more preferably 100 mol %.
The alcohol component (A-al) may contain alcohol components other than the alkylene oxide adduct of bisphenol A represented by the general formula (I).
Other alcohol components that the alcohol component (A-al) may contain include, for example, the same alcohols as those mentioned above as the alcohol component (C-al).

{Carboxylic acid component (A-ac)}
The content of succinic acid in the carboxylic acid component (A-ac) is 5 mol% or more and 40 mol or less, preferably 7 mol% or more, more preferably 7 mol% or more, from the viewpoint of low-temperature fixability, charging stability and image density. 10 mol% or more, more preferably 11 mol% or more, still more preferably 12 mol% or more, and preferably 35 mol% or less, more preferably 30 mol% or less, still more preferably 25 mol% or less, and even more It is preferably 20 mol % or less, more preferably 15 mol % or less.

Examples of carboxylic acids other than succinic acid that can be contained in the carboxylic acid component (A-ac) include linear aliphatic dicarboxylic acid compounds other than succinic acid, aromatic dicarboxylic acid compounds, and trivalent or higher polyvalent carboxylic acid compounds. Among them, aromatic dicarboxylic acid compounds are preferred from the viewpoint of charging stability and image density, more preferably one or more selected from terephthalic acid and isophthalic acid, and still more preferably terephthalic acid.
The content of the aromatic dicarboxylic acid compound in the carboxylic acid component (A-ac), preferably the content of one or more selected from terephthalic acid and isophthalic acid, and more preferably the content of terephthalic acid, each independently From the same viewpoint as above, preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 75 mol% or more, even more preferably 80 mol% or more, and even more preferably 85 mol% or more, From the same viewpoint, it is preferably 95 mol% or less, more preferably 93 mol% or less, even more preferably 90 mol% or less, even more preferably 89 mol% or less, and even more preferably 88 mol% or less.

The equivalent ratio (COOH group/OH group) of the carboxylic acid component (A-ac) to the alcohol component (A-al) is preferably 0.7 or more, more It is preferably 0.8 or more, more preferably 0.9 or more, and preferably 1.2 or less, more preferably 1.1 or less, and still more preferably 1.0 or less.
From the viewpoint of adjusting physical properties, the alcohol component (A-al) may appropriately contain a monohydric alcohol, and the carboxylic acid component (A-ac) may suitably contain a monovalent carboxylic acid compound. may be

[Vinyl resin segment (AH-2)]
The mass ratio [(AH-2)/(AH)] of the vinyl resin segment (AH-2) in the amorphous composite resin (AH) is preferable from the viewpoint of low-temperature fixability, charging stability and image density. is 5/100 or more, more preferably 10/100 or more, still more preferably 15/100 or more, and from the same viewpoint, preferably 40/100 or less, more preferably 30/100 or less, still more preferably 25 /100 or less.
As the monomer component (A-st) of the vinyl resin segment (AH-2), the monomer component (Ch-st) of the vinyl resin segment (CH-2) described above in the section of the crystalline composite resin (CH) , and preferred embodiments thereof (including the composition of each compound and their content) are also the same.

[Double-reactive monomer]
The amorphous composite resin (AH) preferably further contains structural units derived from bi-reactive monomers.
Examples of the bi-reactive monomer include the same bi-reactive monomers mentioned as the raw material component of the crystalline composite resin (CH), and the preferred types thereof are also the same.
The content of the dually reactive monomer is preferably 1 mol part or more, more preferably 3 mol parts, per 100 mol parts of the alcohol component (A-al), from the viewpoint of low-temperature fixability, charging stability and image density. Above, it is more preferably 5 mol parts or more, and preferably 30 mol parts or less, more preferably 20 mol parts or less, still more preferably 10 mol parts or less, still more preferably 7 mol parts or less.

[Method for producing amorphous composite resin (AH)]
The amorphous composite resin (AH) can be produced by the same methods as the production methods (1) to (3) of the crystalline composite resin (CH).
Among the methods (1) to (3), the amorphous composite resin (AH) is preferably produced by the same method as the method (1), and the same method as the method having the steps I to III. Those manufactured by the method are more preferable.
Incidentally, the method similar to the method having the production methods (1) to (3) of the crystalline composite resin (CH) specifically refers to the crystalline composite resin (CH) in the above (1) to (3). , polyester segment (CH-1), alcohol component (C-al), carboxylic acid component (C-ac), vinyl resin segment (CH-2), and monomer component (Ch-st), respectively, amorphous complex resin (AH), polyester segment (AH-1), alcohol component (A-al), carboxylic acid component (A-ac), vinyl resin segment (AH-2), and monomer component (A-st) A method similar to that replaced with

Then, in the method for producing the amorphous composite resin (AH), from the viewpoint of further improving the image density, the method including the steps I to III is produced by a method with the following changes. is more preferred.
Regarding step I, it is preferable to change the following points with respect to the above-described method.
It is preferable to add a carboxylic acid other than succinic acid to the carboxylic acid component (A-ac) as a raw material component of the polyester segment (AH-1) to be subjected to step I. It is more preferable to add in Step I the total amount of carboxylic acids other than succinic acid and the total amount of alcohol component (A-al) in carboxylic acid component (A-ac).
The temperature of the polycondensation reaction in step I is preferably 150° C. or higher, preferably 250° C. or lower, more preferably 240° C. or lower, from the viewpoint of reactivity.
Further, the polycondensation reaction in step I is terminated at the time when the starting material component of the polyester segment (AH-1) subjected to step I is preferably 85 mol% or more, more preferably 90 mol% or more. preferable.
Moreover, it is preferable to carry out the step I in the presence of the esterification catalyst and the esterification co-catalyst.

Regarding step III, it is preferable to change the following points with respect to the above-described method.
It is preferable to add the entire amount of succinic acid contained in the carboxylic acid component (A-ac) as a raw material component of the remaining polyester segment (AH-1) to be subjected to Step III.
Therefore, from the viewpoint of further improving the image density, the amorphous composite resin (AH) is prepared by adding succinic acid after polycondensing a carboxylic acid other than succinic acid as the carboxylic acid component (A-ac). , is more preferably a resin obtained by polycondensation. That is, from the viewpoint of further improving the image density, the amorphous composite resin (AH) is considered to be a resin having a structure derived from succinic acid at the end of the polyester segment (AH-1).

The esterification catalyst, esterification co-catalyst, polymerization initiator and polymerization inhibitor used in the production of the amorphous composite resin (AH) may be the esterification catalysts described above in the section of the crystalline composite resin (CH). , esterification cocatalyst, polymerization initiator and polymerization inhibitor, and when these are used, preferred embodiments are also the same.
When an esterification catalyst is used in the production of the amorphous composite resin (AH), the amount of the alcohol component (A-al ) and the carboxylic acid component (A-ac) is preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less.
When an esterification co-catalyst is used in the production of the amorphous composite resin (AH), the amount of the alcohol component (A-al ) and the carboxylic acid component (A-ac) in an amount of 100 parts by mass, preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and preferably 0.2 parts by mass. Below, more preferably 0.1 parts by mass or less.

From the viewpoint of storage stability, the softening point of the amorphous composite resin (AH) is preferably 80°C or higher, more preferably 90°C or higher, still more preferably 100°C or higher, and even more preferably 106°C or higher, and C., preferably 140.degree. C. or less, more preferably 130.degree. C. or less, still more preferably 120.degree.
The glass transition temperature of the amorphous composite resin (AH) is preferably 30° C. or higher, more preferably 50° C. or higher, still more preferably 55° C. or higher, and even more preferably 58° C. or higher, from the viewpoint of storage stability. From the viewpoint of low-temperature fixability, the temperature is preferably 80° C. or lower, more preferably 70° C. or lower, even more preferably 65° C. or lower, and even more preferably 62° C. or lower.
The acid value of the amorphous composite resin (AH) is preferably 3 mgKOH/g or more, more preferably 5 mgKOH/g or more, still more preferably 10 mgKOH/g or more, still more preferably from the viewpoint of low-temperature fixability and image density. is 15 mgKOH/g or more, and from the same viewpoint, it is preferably 40 mgKOH/g or less, more preferably 30 mgKOH/g or less, still more preferably 20 mgKOH/g or less.
The softening point, glass transition temperature, and acid value of the amorphous composite resin (AH) can be appropriately adjusted depending on the type and ratio of raw material monomers, and production conditions such as reaction temperature, reaction time, and cooling rate. Also, the softening point, glass transition temperature, and acid value of the amorphous composite resin (AH) are determined by the methods described in Examples.

In addition to the amorphous composite resin (AH), the shell may contain known resins used in toners, such as polyesters other than the amorphous composite resin (AH), styrene, etc., as long as the effects of the present invention are not impaired. - It may contain styrenic resin such as acrylic copolymer, epoxy, polycarbonate, polyurethane, and the like.
In the binder resin constituting the shell, the amount of the amorphous composite resin (AH) is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass. % by mass or more, preferably 100% by mass or less, and more preferably 100% by mass.

In the toner particles, the mass ratio of the binder resin used for the core and the binder resin used for the shell [core binder resin/shell binder resin] is preferably 70/30 or more, more preferably 75/25 or more. , more preferably 80/20 or more, and preferably 97/3 or less, more preferably 95/5 or less, even more preferably 90/10 or less, and even more preferably 85/15 or less.

Toner particles contain colorants, charge control agents, release agents, magnetic powders, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, cleaning improvers, and the like. may contain additives. The additive may be contained in the core or shell, but is preferably contained in the core.

[Coloring agent]
As the colorant, all dyes, pigments, etc. used as colorants for toners can be used.
Dyes include azine dyes, anthraquinone dyes, perinone dyes, rhodamine dyes, and the like.
The pigment may be either an inorganic pigment or an organic pigment. Examples of inorganic pigments include carbon black and metal oxides. Examples of organic pigments include azo pigments, diazo pigments, phthalocyanine pigments, quinacridone pigments, Examples include isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthraquinone pigments and quinophthalone pigments. You may use these individually or in combination of 2 or more types.
From the viewpoint of improving the image density of the toner, the amount of the colorant is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more with respect to the total of 100 parts by mass of the binder resin. is 40 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less.

[Charge control agent]
Examples of charge control agents include chromium-based azo dyes, iron-based azo dyes, aluminum azo dyes, salicylic acid metal complexes, and the like. You may use these individually or in combination of 2 or more types.
From the viewpoint of charging stability of the toner, the amount of the charge control agent is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the binder resin in total, and , preferably 3 parts by mass or less, more preferably 1.5 parts by mass or less.

〔Release agent〕
Release agents include polyolefin wax, paraffin wax, silicones; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide; carnauba wax, rice wax, candelilla wax, wood wax, jojoba animal waxes such as beeswax; mineral and petroleum waxes such as montan wax, ozokerite, ceresin, microcrystalline wax and Fischer-Tropsch wax. You may use these individually or in combination of 2 or more types.
The amount of the release agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 4 parts by mass or more, and preferably 20 parts by mass with respect to the total of 100 parts by mass of the binder resin. parts or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less.

The volume-median particle diameter (D ₅₀ ) of the toner particles is preferably 2 μm or more, more preferably 3 μm or more, and still more preferably 4 μm or more, from the viewpoint of further improving low-temperature fixability, charging stability and image density. And it is preferably 10 μm or less, more preferably 8 μm or less, still more preferably 7 μm or less.
The amount of toner particles in the toner is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, from the same viewpoint as above, and , 100% by mass or less, preferably 99% by mass or less.

<External Additives>
Although the toner particles can be used as they are as a toner, it is preferable to subject the toner particles to a surface treatment using an external additive in order to improve the fluidity of the toner.
Examples of external additives include inorganic particles such as silica, alumina, zirconia, titanium oxide, tin oxide and zinc oxide; organic particles such as resin particles; The toner may contain one or more of these external additives. The toner preferably contains at least one selected from silica and titanium oxide as an external additive, and more preferably contains at least silica. The silica is more preferably hydrophobic silica that has been subjected to hydrophobizing treatment.
Hydrophobizing agents for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), methyltriethoxysilane, and the like. be done.
When the toner particles are surface-treated using an external additive, the amount of the external additive is preferably 0.1 mass parts per 100 parts by mass of the toner particles, from the viewpoint of charging property and fluidity of the toner. parts or more, more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less.

The volume-median particle diameter ( _D50 ) of the toner is preferably 3.0 μm or more, more preferably 4.0 μm or more, and still more preferably 4.0 μm or more, from the viewpoint of further improving low-temperature fixability, charging stability and image density. It is 5 μm or more, and preferably 9.0 μm or less, more preferably 8.5 μm or less, and even more preferably 7.5 μm or less.

[Manufacturing Method of Toner for Developing Electrostatic Charge Image]
The toner of the present invention is preferably produced, for example, by a method including steps 1 to 5 below.
Step 1-1: Step of mixing a styrene resin (AS) and an organic solvent to obtain a liquid containing the styrene resin (AS) Step 1-2: Containing the styrene resin (AS) obtained in Step 1-1 A step of mixing at least water with the liquid to obtain an aqueous dispersion of resin particles (X1) containing a styrene resin (AS) Step 2-1: Composite crystalline resin (CH), organic solvent and neutralizing agent Step of mixing to obtain a crystalline composite resin (CH)-containing liquid Step 2-2: Mixing at least water with the crystalline composite resin (CH)-containing liquid obtained in step 2-1 to obtain a crystalline composite resin Step of obtaining an aqueous dispersion of resin particles (X2) containing (CH) Step 3: mixing the resin particles (X1) obtained in step 1-2 and the resin particles (X2) obtained in step 2-2 and aggregating in an aqueous medium to obtain aggregated particles (1) Step 4: resin particles (Y) containing the amorphous composite resin (AH) in the aggregated particles (1) obtained in step 3 aggregating to obtain aggregated particles (2) Step 5: fusing the aggregated particles (2) obtained in step 4 to obtain core-shell particles

<Step 1-1>
(organic solvent)
As the organic solvent, from the viewpoint of solubility, alcohol solvents such as isopropanol and isobutanol; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and diethyl ketone; ether solvents such as dibutyl ether and dioxane; ethyl acetate and isopropyl acetate. Acetic acid ester solvents such as are preferably mentioned.

(Surfactant)
In step 1-1, it is preferable to use a surfactant from the viewpoint of low-temperature fixability, charge stability and image density of the resulting toner.
Surfactants include nonionic, anionic and cationic surfactants. Among these, from the viewpoint of emulsion stability of the resin, one or more selected from nonionic surfactants and anionic surfactants are preferred, and anionic surfactants are more preferred.
In step 1-1, the above-mentioned colorant, charge control agent, release agent, magnetic powder, fluidity improver, conductivity modifier, reinforcing filler such as fibrous substance, antioxidant, anti-aging agent , cleaning improvers, and other optional additives may be added. Additives such as colorants, charge control agents, and release agents may be mixed in advance with the binder resin. In this case, the binder resin and additives are preferably melt-kneaded.
For melt-kneading, it is preferable to use an open-roll type twin-screw kneader. An open-roll type twin-screw kneader is a kneader in which two rolls are arranged in parallel and close to each other, and a heating function or a cooling function can be imparted by passing a heating medium through each roll.

<Step 1-2>
Methods for obtaining an aqueous dispersion of resin particles (X1) include a method in which a resin or the like is added to an aqueous medium and dispersed using a disperser, a method in which an aqueous medium is gradually added to a resin or the like to effect phase inversion emulsification, and the like. mentioned.
When a disperser is used, it is preferable to use a disperser such as an ultrasonic homogenizer to disperse the resin particles (X1) containing the styrene resin (AS) in the aqueous medium.
The aqueous medium is a liquid containing at least water, preferably containing water as a main component.
Components other than water that the aqueous medium may contain include organic solvents that dissolve in water, such as methanol, ethanol, acetone, and cyclic ethers such as tetrahydrofuran.
In step 1-2, it is preferable to remove the organic solvent used in step 1-1 from the resulting aqueous dispersion. The method for removing the organic solvent is not particularly limited, and any method can be used, but distillation is preferred because it is dissolved in water.

<Step 2-1>
As the organic solvent used in step 2-1, the same organic solvent as described in step 1-1 can be used, and the preferred embodiments are also the same.

(Neutralizer)
Neutralizing agents used in step 2-1 include metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonia; organic compounds such as trimethylamine, ethylamine, diethylamine, triethylamine, triethanolamine and tributylamine bases.
In step 2-1, it is preferable to use a surfactant from the viewpoint of further improving the low-temperature fixability, charging stability and image density of the resulting toner. As the surfactant used in step 2-1, the same surfactants as those described above in step 1-1 can be used, and preferred embodiments thereof are also the same.
Also, in step 2-1, any of the aforementioned additives may be added.

<Step 2-2>
Methods for obtaining an aqueous dispersion of resin particles (X2) include a method of adding a resin or the like to an aqueous medium and dispersing it using a dispersing machine, a method of gradually adding an aqueous medium to the resin or the like and subjecting the mixture to phase inversion emulsification, and the like. From the viewpoint of further improving the low-temperature fixability, charging stability and image density of the resulting toner, a method of gradually adding an aqueous medium to a resin or the like for phase inversion emulsification is preferred.
In the phase inversion emulsification method, a W/O phase is first formed by adding an aqueous medium to a crystalline composite resin (CH)-containing liquid, and then the phase is inverted to an O/W phase. Whether or not phase inversion occurs can be confirmed by visual observation or electrical conductivity, for example.
As the aqueous medium, the same one as described in step 1-2 can be used, and the preferred embodiments are also the same.
In step 2-2, it is preferable to remove the organic solvent used in step 2-1 from the resulting aqueous dispersion. The method for removing the organic solvent is not particularly limited, and any method can be used. Examples thereof include the same methods as those described above in Step 1-2, and preferred embodiments thereof are also the same.

<Step 3>
In step 3, it is preferable to add a flocculating agent for efficient flocculation.
As the flocculant, organic flocculants such as quaternary salt cationic surfactants and polyethyleneimine; and inorganic flocculants such as inorganic metal salts and inorganic ammonium salts are used. From the viewpoint of the particle size distribution of the resulting toner, inorganic flocculants are preferred, and inorganic metal salts are particularly preferred.
Examples of inorganic metal salts include sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, and aluminum chloride.
Alternatively, in step 3, the agglomeration may be performed after adding any of the additives described above.

<Step 4>
The resin particles (Y) are preferably obtained as an aqueous dispersion of the resin particles (Y). By using the amorphous composite resin (AH) as the binder resin, the aqueous dispersion of the resin particles (X2) and It can be manufactured by a similar method.
In step 4, an aqueous dispersion of resin particles (Y) is added to the dispersion of aggregated particles (1) obtained in step 3 to further adhere resin particles (Y) to aggregated particles (1). , it is preferable to obtain a dispersion of aggregated particles (2).
In step 4, the total amount of the resin particles (Y) may be added, and aggregation may be stopped when the toner particles have grown to an appropriate particle size. Methods for stopping aggregation include a method of cooling the dispersion, a method of adding an aggregation inhibitor, and a method of diluting the dispersion. From the viewpoint of reliably preventing unnecessary aggregation, a method of stopping aggregation by adding an aggregation terminator is preferred.
As the aggregation terminator, a surfactant is preferably used, and an anionic surfactant is more preferably used. The aggregation terminator may be added as an aqueous solution.

<Step 5>
The temperature in the system in step 5 is preferably 70° C. from the viewpoints of the target toner particle size, particle size distribution, shape control and particle fusibility, low temperature fixability, charging stability and image density. Above, it is more preferably 75° C. or higher, and preferably 100° C. or lower, more preferably 90° C. or lower, and still more preferably 85° C. or lower.
By appropriately subjecting the core-shell particles obtained in step 5 to a solid-liquid separation step such as filtration, a washing step, and a drying step, the toner particles can be preferably obtained.
In the washing step, it is preferable to completely remove the added surfactant by washing.

<External Addition Process>
In order to improve the fluidity of the toner, it is preferable to perform surface treatment of the toner particles using the aforementioned external additive in the external addition step. Preferred aspects and amounts of the external additive are as described above.

The toner for developing an electrostatic charge image and the toner for developing an electrostatic charge image obtained by the above production method can be suitably used as a one-component developing toner or as a two-component developer mixed with a carrier. , a one-component development system or a two-component development system image forming apparatus.

The raw materials used and the properties of the obtained resins, particles, dispersions, toners, etc. were measured and evaluated by the following methods.

[Resin softening point, crystallinity index, melting point and glass transition temperature]
(1) Softening point Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a temperature increase rate of 6 ° C./min, a load of 1.96 MPa is applied with a plunger, and the diameter It was extruded through a 1 mm, 1 mm long nozzle. The amount of plunger depression of the flow tester was plotted against the temperature, and the softening point was defined as the temperature at which half of the sample flowed out.
(2) Crystallinity index Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan and cooled at a rate of 10 from room temperature (25 ° C.). Cooled to 0°C at °C/min. Next, the sample was held as it was for 1 minute, and then heated to 180°C at a heating rate of 10°C/min, and the calorific value was measured. Among the observed endothermic peaks, the temperature of the peak with the maximum peak area is defined as the maximum endothermic peak temperature (1), and (softening point (°C)) / (maximum endothermic peak temperature (1) (°C)) A crystallinity index was determined.
(3) Melting point and glass transition temperature Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed in an aluminum pan, heated to 200 ° C., It was cooled from that temperature to 0°C at a cooling rate of 10°C/min. Then, the temperature of the sample was increased at a temperature increase rate of 10°C/min, and the calorie was measured. Among the observed endothermic peaks, the temperature of the peak with the maximum peak area was defined as the maximum endothermic peak temperature (2). In the case of a crystalline resin, the peak temperature was taken as the melting point.
In the case of an amorphous resin, when a peak is observed, the temperature of the peak is measured. The temperature at the point of intersection with the extended line of the baseline on the low temperature side was defined as the glass transition temperature.

[Acid value and hydroxyl value of resin]
The acid value and hydroxyl value of the resin were measured according to the neutralization titration method described in JIS K 0070:1992. However, regarding the measurement solvent, if the resin is amorphous, a mixed solvent of ethanol and ether specified in the JIS standard, a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)) , and measured. When the resin was crystalline, the mixed solvent was changed to chloroform for the measurement.

[Volume Median Particle Diameter ( _D50 ) of Colorant Particles, Charge Control Agent Particles, Release Agent Particles, and Binder Resin Composition Particles]
(1) Measuring device: Laser diffraction particle size measuring machine “LA-920” (manufactured by HORIBA, Ltd.)
(2) Measurement conditions: Distilled water was added to the measurement cell, and the volume-median particle size (D ₅₀ ) was measured at a concentration at which the absorbance was within the proper range.

[Colorant Dispersion, Charge Control Agent Dispersion, Release Agent Dispersion, Solid Concentration of Aqueous Dispersion of Binder Resin Composition Particles]
Using an infrared moisture meter "FD-230" (manufactured by Ketsuto Kagaku Kenkyusho Co., Ltd.), 5 g of the sample is dried at a temperature of 150 ° C. and under the conditions of measurement mode 96 (monitoring time 2.5 minutes, fluctuation width 0.05%). The sample was dried with a vacuum cleaner, and the moisture content (% by mass) of the sample was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (mass%) = 100-M
M: Moisture content of the sample (% by mass)

[Volume median particle size ( _D50 ) of aggregated particles and toner during toner manufacture]
The volume median particle size ( _D50 ) of the aggregated particles and toner during toner manufacture was measured as follows.
・ Measuring device: "Coulter Multisizer III" (manufactured by Beckman Coulter, Inc.)
・Aperture diameter: 50 μm
・ Analysis software: "Coulter Multisizer III Version 3.51" (manufactured by Beckman Coulter, Inc.)
・Electrolyte solution: “Isoton (registered trademark) II” (manufactured by Beckman Coulter, Inc.)
- Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin method) = 13.6] is dissolved in the electrolyte to obtain a dispersion with a concentration of 5% by mass. rice field.
- Dispersion conditions: Add 10 mg of the measurement sample (in terms of solid content) to 5 mL of the dispersion liquid, disperse it for 1 minute with an ultrasonic disperser, then add 25 mL of the electrolytic solution, and further 1 with an ultrasonic disperser. A sample dispersion was prepared by dispersing for minutes.
Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured. A volume-median particle size ( _D50 ) was obtained from the obtained particle size distribution.

[Number average particle size of external additive]
The number average particle size of 500 particles measured from a scanning electron microscope (SEM) photograph was taken as the number average particle size of the external additive. If there is a major axis and a minor axis, it refers to the major axis.

[Toner evaluation]
<Low temperature fixability>
Toner was mounted on a color page printer (non-magnetic one-component developing device) "Microline (registered trademark) 5400" (manufactured by Oki Data Co., Ltd.) so that the toner adhesion amount was 0.45±0.03 mg/cm ² . After adjustment, a solid image of 4.1 cm×13.0 cm was printed on "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.). An unfixed image was obtained by removing the solid image before passing through the fixing device. The obtained unfixed image was fixed at 240 mm/sec by setting the temperature of the fixing roll to 100° C. and using an external fixing device that was a modification of the fixing device of “Microline (registered trademark) 3010” (manufactured by Oki Data Co., Ltd.). Fixed at speed. After that, the fixing roll temperature was set to 105° C., and the same operation was performed. The unfixed image was fixed at each temperature while increasing the temperature by 5° C. up to 200° C. to obtain a fixed image. After attaching a mending tape (manufactured by 3M Japan Co., Ltd.) to the image fixed at each temperature, a 500 g cylindrical weight was placed so that the contact area with the tape was 4 cm ² , and pressure was applied for 1 minute. was applied to sufficiently adhere the tape to the fixed image. Thereafter, the mending tape was slowly peeled off from the fixed image, and the reflection image density of the image after the tape was peeled off was measured using a reflection densitometer "RD-915" (manufactured by Gretag Macbeth). The reflection image density of the image before application of the tape was also measured in advance, and the ratio of the measured value ([reflection image density after tape removal/reflection image density before tape application]×100) initially exceeded 90%. The temperature of the fixing roll exceeding the minimum fixing temperature was taken as an index of low-temperature fixability.

<Charging stability under high temperature and high humidity>
After the toner was left for 72 hours in an environment with a temperature of 40° C. and a humidity of 80%, 0.6 g of the toner and 19.4 g of silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size: 90 μm) were added to 50 mL of polyethylene. and mixed with a ball mill at 250 r/min. After mixing for 60 seconds and 3,600 seconds, the charge amount of each toner was measured by a Q/M meter (EPPING Co., Ltd.) by the following method. (manufactured).
After a predetermined mixing time, a specified amount of a mixture of toner and carrier is put into a cell attached to a Q/M meter, and the toner alone is passed through a 32 μm mesh sieve (made of stainless steel, twill weave, wire diameter: 0.0035 mm) for 90 seconds. aspirated. The voltage change on the carrier generated at that time was monitored, and the value of [total amount of electricity (μC) after 90 seconds/amount of toner attracted (g)] was taken as the amount of charge (μC/g).
The ratio of the charge amount after 60 seconds of mixing time to the charge amount after 3,600 seconds of mixing time (charge amount after 3,600 seconds of mixing time/charge amount after 60 seconds of mixing time) was calculated. The closer to 1 the charge amount ratio, the better the charge stability, and the ratio is preferably 0.70 or more, more preferably 0.80 or more, and even more preferably 0.90 or more.

<Image Density>
Using a color page printer (non-magnetic single-component developing device) "Microline (registered trademark) 5400" (manufactured by Oki Data Co., Ltd.) on high-quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), the toner on the paper A solid image having an adhesion amount of 0.45±0.03 mg/cm ² was output to obtain a printed matter.
Next, the temperature of the fixing device was set to 130° C., and the toner was fixed at a rate of 1.5 seconds per A4 sheet in the longitudinal direction to obtain a printed matter.
The reflected image density of the fixed image portion of the output print was measured using a colorimeter "SpectroEye" (manufactured by GretagMacbeth, light irradiation conditions; standard light source D50, observation field of view 2°, density standard DINNB, absolute white standard). . The higher the reflection image density, the better the image density.

[Manufacturing of crystalline resin for core]
Synthesis Examples 1 to 3 (Production of Core Crystalline Composite Resins C-1 to C-3)
Of the raw material components of the polyester segment shown in Table 1 below, the total amount of the alcohol component and half the amount (50% by mass) of the carboxylic acid component are each equipped with a thermometer, a stainless steel stirring rod, a flow-down type condenser and a nitrogen introduction tube. The mixture was placed in a four-necked flask with an internal volume of 10 liters, heated from 135°C to 160°C over 6 hours in a nitrogen atmosphere in a mantle heater, and then reacted at 160°C. Thereafter, after confirming that the reaction rate reached 95% or more, a mixed solution of raw material monomers for the vinyl resin segment, bi-reactive monomers and radical polymerization initiator shown in Table 1 below was added dropwise over 1 hour. Then, after holding at 160° C. for 30 minutes, the remaining carboxylic acid component was added and the temperature was raised from 130° C. to 200° C. over 8 hours. After that, the reaction was further carried out under a reduced pressure of 8 kPa until the softening point shown in Table 1 below was reached, and each crystalline composite resin (CH) for cores was obtained. In addition, the said reaction rate is a value calculated using the following formula. The same applies hereinafter throughout the specification.
Reaction rate = [amount of reaction water produced (mol) / theoretical amount of water produced (mol)] x 100

Synthesis Example 4 (Production of crystalline polyester C-4 for core)
The raw material monomers shown in Table 1 below were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser, and a nitrogen inlet tube, and heated to 130°C in a nitrogen atmosphere in a mantle heater. After the temperature was raised from to 200°C over 8 hours, the reaction was carried out at 200°C for 2 hours. After that, the esterification catalyst shown in Table 1 below was further added, and the reaction was carried out under a reduced pressure of 8 kPa until the softening point shown in Table 1 below was reached, to obtain a crystalline polyester for core C-4.

[Production of core styrene resin (AS)]
Synthesis Example 5 (Production of core styrene resin A-1)
Place 2 liters of xylene in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser, a dropping funnel, and a nitrogen inlet tube, and use the raw material monomer for the styrene resin shown in Table 2 below. and a radical polymerization initiator were placed in a dropping funnel equipped with a four-necked flask. Then, xylene in the four-necked flask was heated to 135° C. under a nitrogen atmosphere, and a mixture of raw material monomers and a polymerization initiator was dropped into xylene from a dropping funnel over 1 hour. Furthermore, the temperature was raised to 200° C. and held at 200° C. for 2 hours. Thereafter, xylene was further removed by holding under reduced pressure of 8 kPa for 1 hour to obtain core styrene resin (A-1).

[Production of amorphous composite resin for shell]
Synthesis Examples 6 to 10 (Production of Amorphous Composite Resins A-2 to A-6 for Shell)
Of the raw material components of the polyester segment (AH-1) shown in Table 3 below, the raw materials other than succinic acid, the esterification catalyst and the esterification co-catalyst were added to a thermometer, a stainless steel stirring rod, a flow-down condenser and nitrogen introduction. It was placed in a four-necked flask with an internal volume of 10 liters equipped with a tube, and heated to 235° C. over 2 hours in a mantle heater in a nitrogen atmosphere. After confirming that the reaction rate reached 90% or more at 235°C, the mixture was cooled to 160°C. After that, a mixed solution of raw material monomers for the vinyl resin segment (AH-2) shown in Table 3 below, bi-reactive monomers and a radical polymerization initiator was added dropwise over 1 hour. After that, the temperature was maintained at 160°C for 30 minutes, the temperature was raised to 200°C, the reaction was further performed under a reduced pressure of 8 kPa for 1 hour, and the temperature was cooled to 180°C. After that, succinic acid was added under normal pressure, and the temperature was raised to 210° C. over 2 hours. Then, after reacting at 210° C. for 1 hour, the reaction was continued under a reduced pressure of 40 kPa until the softening point shown in Table 4 below was reached, thereby obtaining amorphous composite resins (AH) for shells.

Synthesis Example 11 (Production of Amorphous Composite Resin A-7 for Shell)
Of the raw material components of the polyester segment (AH-1) shown in Table 3 below, a raw material other than fumaric acid, an esterification catalyst and an esterification co-catalyst, a thermometer, a stainless steel stirring rod, a flow-down type condenser and a nitrogen introduction tube It was placed in an equipped four-necked flask with an internal volume of 10 liters, and heated to 235° C. over 2 hours in a mantle heater in a nitrogen atmosphere. After confirming that the reaction rate reached 90% or more at 235°C, the mixture was cooled to 160°C. After that, a mixed solution of raw material monomers for the vinyl resin segment (AH-2) shown in Table 3 below, bi-reactive monomers and a radical polymerization initiator was added dropwise over 1 hour. After that, the temperature was maintained at 160°C for 30 minutes, the temperature was raised to 200°C, the reaction was further performed under a reduced pressure of 8 kPa for 1 hour, and the temperature was cooled to 180°C. After that, under normal pressure, a radical polymerization inhibitor and fumaric acid shown in Table 3 below were added, and the temperature was raised to 210° C. over 2 hours. Then, after reacting at 210° C. for 1 hour, the reaction was continued under a reduced pressure of 40 kPa until the softening point shown in Table 4 below was reached, to obtain an amorphous composite resin for shell A-7.

[Production of colorant dispersion]
Preparation example 1
50 g of copper phthalocyanine "ECB-301" (manufactured by Dainichiseika Kogyo Co., Ltd.), 5 g of nonionic surfactant "Emulgen (registered trademark) 150" (polyoxyethylene lauryl ether, manufactured by Kao Corporation) and 200 g of deionized water and dispersed for 10 minutes using a homogenizer to obtain a colorant dispersion containing colorant particles. The volume-median particle size ( _D50 ) of the colorant particles was 120 nm, and the solid content concentration was 22% by mass.

[Production of charge control agent dispersion]
Preparation example 2
50 g of a salicylic acid-based compound "Bontron (registered trademark) E-84" (manufactured by Orient Chemical Industry Co., Ltd.) as a charge control agent, 5 g of "Emulgen (registered trademark) 150" (manufactured by Kao Corporation) as a nonionic surfactant, and 200 g of ion-exchanged water was mixed and dispersed for 10 minutes using glass beads and a sand grinder to obtain a charge control agent dispersion containing charge control agent particles. The charge control agent particles had a volume-median particle diameter ( _D50 ) of 400 nm and a solid content concentration of 22% by mass.

[Production of Release Agent Dispersion]
Preparation example 3
50 g of paraffin wax "HNP9" (manufactured by Nippon Seiro Co., Ltd.), 5 g of cationic surfactant "Sansol (registered trademark) B50" (manufactured by Kao Corporation, alkylbenzyldimethylammonium chloride) and 200 g of deionized water were heated to 95°C. It is heated and dispersed for 30 minutes at an output of 350 W using an ultrasonic homogenizer (manufactured by Dr. Hielscher Co., Ltd., trade name: "UP-400S") to disperse the release agent containing release agent particles. I got the liquid. The paraffin wax (release agent particles) had a volume median particle diameter ( _D50 ) of 550 nm and a solid content concentration of 22% by mass.

[Production of Aqueous Dispersion of Binder Resin Composition for Toner]
Production Example 1 (Production of aqueous dispersion c-1 of binder resin composition for toner)
In a container with an internal volume of 3 liters equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen inlet tube, 100 g of the crystalline composite resin C-1, 100 g of methyl ethyl ketone, and an anionic surfactant "Emar (registered trademark). 16.7 g (4.5% by mass with respect to 100 g of resin) of E27C" (manufactured by Kao Corporation, solid content: 27% by mass) was added and dissolved at 73°C over 2 hours. A 5 mass % sodium hydroxide aqueous solution was added to the obtained solution so that the degree of neutralization was 70 mol % with respect to the acid value of the resin, and the mixture was stirred for 30 minutes.
Then, while maintaining the temperature at 73° C. and stirring at 280 r/min (peripheral speed of 88 m/min), 675 g of ion-exchanged water was added over 77 minutes for phase inversion emulsification. Methyl ethyl ketone was distilled off under reduced pressure while the temperature was continuously maintained at 73°C. After that, the aqueous dispersion was cooled to 30° C. while stirring at 280 r/min (peripheral speed 88 m/min). After that, the solid content concentration of the aqueous dispersion is measured, and ion-exchanged water is added so that the solid content concentration becomes 20% by mass. An aqueous dispersion c-1 of the resin-adhering composition was obtained.
Table 4 below shows the volume median particle diameter (D ₅₀ ) of the binder resin composition particles for toner in the obtained aqueous dispersion and the solid content concentration of the aqueous dispersion of the binder resin composition for toner.

Production Examples 2 to 4 and 6 to 11 (Production of Aqueous Dispersions c-2 to c-4 and a-2 to a-7 of Binder Resin Compositions for Toners)
Aqueous dispersion c- of each binder resin composition for toner was prepared in the same manner as in Production Example 1, except that in Production Example 1, the crystalline composite resin C-1 was changed to the type of resin shown in Tables 4 and 5. 2 to c-4 and a-2 to a-7 were obtained.
The volume-median particle size ( _D50 ) of the toner binder resin composition particles in each aqueous dispersion obtained and the solid content concentration of each aqueous dispersion of each binder resin composition for toner are shown in Tables 4 and 5 below. shown in

Production Example 5 (Production of Aqueous Dispersion a-1 of Binder Resin Composition for Toner)
100 g of amorphous styrene resin A-1, 100 g of methyl ethyl ketone, 16.7 g of anionic surfactant "Emal (registered trademark) E27C" (manufactured by Kao Corporation, solid content 27% by mass) (amorphous styrene (corresponding to 4.5 parts by mass of solid content per 100 parts by mass of Resin A-1) was mixed at 25° C. and dissolved at 73° C. over 2 hours. The resulting solution was mixed with 600 g of ion-exchanged water at 73° C., and dispersed using an ultrasonic homogenizer (manufactured by Dr. Hielscher, trade name: “UP-400S”) at an output of 350 W for 30 minutes. Thereafter, methyl ethyl ketone was distilled off under reduced pressure at 70° C. to obtain an aqueous dispersion. Thereafter, the solid content concentration of the aqueous dispersion is measured, and ion-exchanged water is added so that the solid content concentration becomes 20% by mass. An aqueous dispersion a-1 of a binder resin composition was obtained.
Table 5 below shows the volume-median particle diameter (D ₅₀ ) of the binder resin composition particles for toner in the obtained aqueous dispersion and the solid content concentration of the aqueous dispersion of the binder resin composition for toner.

[Production of Toner for Developing Electrostatic Charge Image]
Example 1 (Production of Toner A)
45 g of an aqueous dispersion c-1 of a binder resin composition for toner containing a crystalline composite resin C-1, and an aqueous dispersion a- of a binder resin composition for a toner containing an amorphous styrene resin A-1 210 g of 1, 8 g of the colorant dispersion, 20 g of the release agent dispersion, 2 g of the charge control agent dispersion and 52 g of deionized water were placed in a container with an internal volume of 2 liters, and stirred at 100 r/min (circumference) with an anchor type stirrer. While stirring at a speed of 31 m/min), 150 g of a 0.1% by mass calcium chloride aqueous solution was added dropwise at 20° C. over 30 minutes. After that, the temperature was raised to 50° C. while stirring. It was held at 50° C. until the volume median particle size (D ₅₀ ) reached 5 μm. Immediately thereafter, 45 g of aqueous dispersion a-2 of a binder resin composition for toner containing amorphous composite resin A-2 was added and dispersed by stirring. Thereafter, a diluted solution obtained by diluting 4.2 g of an anionic surfactant "Emal (registered trademark) E27C" (manufactured by Kao Corporation, solid content 27% by mass) with 37 g of deionized water was added as an aggregation terminator. Next, the temperature of the dispersion was raised to 80°C, and the temperature was maintained at 80°C for 1 hour after reaching 80°C, after which the heating was terminated. After the fused particles were formed in this way, the particles were gradually cooled to 20° C., filtered through a 150-mesh wire mesh (opening of 150 μm), suction-filtered, washed, and dried to obtain toner particles. .

(External addition process)
Based on 100 parts by mass of the toner particles, 1.0 part by mass of hydrophobic silica "NAX-50" (manufactured by Nippon Aerosil Co., Ltd., number average particle diameter 40 nm), hydrophobic silica "R972" (manufactured by Nippon Aerosil Co., Ltd., Number average particle size 16 nm) 0.6 parts by mass, titanium oxide "JMT-150IB" (manufactured by Tayka Corporation, number average particle size 15 nm) 0.5 parts by mass, ST (upper blade) and A0 (lower blade) The mixture was placed in a 10-liter Henschel mixer (manufactured by Nippon Coke Kogyo Co., Ltd.) equipped with a stirring blade and stirred at 3,000 r/min for 2 minutes to obtain Toner A. Table 6 shows the evaluation results of Toner A.

Examples 2 to 7, Comparative Examples 1 to 2 (manufacture of toners B to G and H to I)
Toners B to G and Toners B to G, and HI was obtained. The total amount of the water-based dispersion of the binder resin composition for toner used for the core was the same as in Example 1 (255 g). Table 6 shows the evaluation results of Example Toners B to G and Comparative Example Toners H to I.

As shown in Table 6, it was confirmed that the toners A to G of Examples are toners for electrostatic charge image development excellent in all of low-temperature fixability, charge stability and image density.
On the other hand, Comparative Example toner H, in which the crystalline resin of the core is not the crystalline composite resin (CH), and the raw material constituting the polyester segment portion included in the amorphous composite resin of the shell do not contain succinic acid. It was confirmed that Toner I was inferior to Example Toners A to G in either charging stability or image density.

Claims (5)

A toner for electrostatic charge image development containing toner particles having a core-shell structure having a core and a shell,
The core comprises a styrene resin (AS), an alcohol component (C-al) containing 95 to 100 mol% of 1,4-butanediol, and 95 of an aliphatic dicarboxylic acid compound having 12 to 16 carbon atoms. A polyester segment (CH-1) which is a polycondensation portion with a carboxylic acid component (C-ac) containing mol% or more and 100 mol% or less, and an addition polymerization portion of a monomer component (Ch-st) containing a styrenic compound and a crystalline composite resin (CH) containing a certain vinyl resin segment (CH-2),
The shell is a polycondensation portion of an alcohol component (A-al) containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component (A-ac) containing 5 mol% or more and 40 mol% or less of succinic acid. Segment (AH-1), and an amorphous composite resin (AH) containing a vinyl resin segment (AH-2) which is an addition polymerization portion of a monomer component (A-st) containing a styrene compound, Toner for electrostatic charge image development. 2. The toner for electrostatic charge image development according to claim 1, wherein the carboxylic acid component (A-ac) contains 7 mol % or more of succinic acid. 3. The toner for electrostatic charge image development according to claim 1, wherein the aliphatic dicarboxylic acid compound is a linear aliphatic dicarboxylic acid compound. Claims 1 to 3, wherein acrylic acid is contained in the raw material components of the amorphous composite resin (AH) at 1 mol part or more and 7 mol parts or less with respect to 100 mol parts of the alcohol component (A-al). The toner for electrostatic charge image development according to any one of the above. 5. Any one of claims 1 to 4, wherein the raw material components of the crystalline composite resin (CH) contain 1 mol part or more and 4 mol parts or less of acrylic acid with respect to 100 mol parts of the alcohol component (C-al). 1. The toner for electrostatic image development according to 1. above.