JP5872891B2 - Method for producing toner for developing electrostatic latent image - Google Patents

Description

  The present invention relates to a method for producing an electrostatic latent image developing toner and an electrostatic latent image developing toner obtained thereby.

With the development of electrophotographic systems and the like, development of toners corresponding to higher image quality and higher speed is required.
As a method for producing a toner having a controlled particle size or a reduced particle size corresponding to high image quality, a method of emulsifying a resin in water or obtaining colored resin particles by polymerization in water has been performed. . Among them, an aggregation coalescence method (emulsion aggregation method, aggregation fusion method) is performed in which fine resin particles and the like are aggregated and fused in an aqueous medium to obtain a toner. Furthermore, in order to improve thermal characteristics such as fixing property and offset resistance, attempts have been made to use a mixture of a plurality of types of resins.

For example, Patent Document 1 discloses a resin particle (A) containing a colorant, a crystalline polyester (a), and a release agent particle for the purpose of improving low-temperature fixability, chargeability, and storage stability. A step of agglomerating in an aqueous medium to obtain core agglomerated particles, a step of attaching resin particles (B) containing amorphous polyester (b) in an aqueous medium to obtain a core-shell agglomerated particles, and a specific temperature; And a method for producing a toner for electrophotography, which comprises a step of obtaining core-shell particles having a specific circularity by holding in the above.
Patent Document 2 discloses that a vinyl resin and a polyester having an acid value of 5 to 50 mgKOH / g are used for the purpose of obtaining a toner having a small particle size that has no off-flavor, good fixability, and a sharp particle size distribution. A method for producing a toner comprising a step of forming aggregated particles from a water-based resin dispersion obtained by polymerizing a raw material monomer of the vinyl-based resin in the presence of a neutralized product of the polyester is disclosed. ing.
Patent Document 3 discloses a polyester resin obtained by condensing a polyhydric alcohol and an unsaturated polyvalent carboxylic acid for the purpose of eliminating offset and excessive gloss and obtaining a toner that does not have toner detachment at a crease, that is, insufficient fixing strength In a water-based medium to prepare a polyester resin particle dispersion, and after adding a vinyl polymerizable monomer and a radical polymerization initiator to the polyester resin particle dispersion, a radical polymerization reaction is carried out on the polyester resin. A step of preparing a dispersion of resin particles made of a resin reacted with a vinyl polymerizable monomer, a resin particle made of a resin obtained by reacting a vinyl polymerizable monomer with the polyester resin, and a dispersion of colorant particles; And a step of aggregating the resin particles and the colorant particles to form toner particles.

JP 2011-186053 A JP 2004-354413 A JP 2011-95736 A

In order to reduce power consumption during printing and to support high-speed printing, low-temperature fixability (low-temperature fixability) is required. Toner that does not block during high-temperature storage while fixing at low temperatures. It is desired. In addition, according to the toner obtained by the aggregation coalescence method (emulsion aggregation method, aggregation fusing method) using polyester, a high-quality print can be obtained with a small particle size, but polyester has a carboxyl group and a hydroxyl group at the molecular end. Since it is difficult to adjust the chargeability in a low temperature and low humidity environment, there is a problem that the image density in a low temperature and low humidity environment becomes low.
An object of the present invention is to provide a method for producing a toner for developing an electrostatic latent image that has both low-temperature fixability and heat-resistant storage stability and is excellent in image density in a low-temperature and low-humidity environment, and for developing an electrostatic latent image obtained thereby. To provide toner.

  The inventors of the present invention have considered that the factors affecting the low-temperature fixability, heat-resistant storage stability, and image density in a low-temperature and low-humidity environment are the composition of the resin of the surface layer constituting the toner. As a result, resin particles containing crystalline polyester as a core part are used in an aggregation fusion method in which resin particles are aggregated in a medium to obtain a dispersion of aggregated particles, and the aggregated particles are fused to obtain a toner. By using resin particles containing an amorphous polyester having an unsaturated bond as a shell portion, and aggregating and fusing them, and then polymerizing with an addition polymerizable monomer having an aromatic group, It has been found that a toner having both high heat storage stability and excellent image density in a low temperature and low humidity environment can be obtained.

That is, the present invention provides the following [1] and [2].
[1] A method for producing a toner for developing an electrostatic latent image, comprising the following steps (1) to (4).
Step (1): Step of obtaining an aqueous dispersion of aggregated particles (1) by mixing and aggregating the resin particles (A) containing the crystalline polyester (a) and the aggregating agent in an aqueous medium. ): The resin particles (B) containing the amorphous polyester (b1) having a non-aromatic carbon-carbon unsaturated bond in the main chain are added to the aqueous dispersion of the agglomerated particles (1) for aggregation. Step for obtaining an aqueous dispersion of aggregated particles (2) Step (3): Step for obtaining an aqueous dispersion of fused particles by fusing the aggregated particles (2) Step (4): Aqueous of the fused particles Step 2 of adding an addition polymerizable monomer (b2) having an aromatic group to the dispersion and polymerizing to obtain an aqueous dispersion of toner particles [2] The electrostatic latent obtained by the production method described in [1] Toner for image development.

  According to the present invention, it is possible to provide a toner production method that achieves both low-temperature fixability and heat-resistant storage stability and is excellent in image density in a low-temperature and low-humidity environment, and a toner obtained thereby.

The toner production method of the present invention includes the following steps (1) to (4).
Step (1): Step of obtaining an aqueous dispersion of aggregated particles (1) by mixing and aggregating the resin particles (A) containing the crystalline polyester (a) and the aggregating agent in an aqueous medium. ): The resin particles (B) containing the amorphous polyester (b1) having a non-aromatic carbon-carbon unsaturated bond in the main chain are added to the aqueous dispersion of the agglomerated particles (1) for aggregation. Step for obtaining an aqueous dispersion of aggregated particles (2) Step (3): Step for obtaining an aqueous dispersion of fused particles by fusing the aggregated particles (2) Step (4): Aqueous of the fused particles A step of adding an addition-polymerizable monomer (b2) having an aromatic group to the dispersion and polymerizing to obtain an aqueous dispersion of toner particles

The reason why the toner obtained by the production method of the present invention can achieve both low-temperature fixability and heat-resistant storage stability and is excellent in image density in a low-temperature and low-humidity environment is not clear, but can be considered as follows.
According to the production method of the present invention, a core-shell type toner having a crystalline polyester in the core portion and an amorphous polyester in the shell portion is obtained by steps (1) to (3). As described above, the toner has excellent low-temperature fixability by having crystalline polyester. Further, in step (4), an addition polymerization resin having an aromatic group in the form of a graft on the outermost surface of the toner is obtained by adding an addition polymerizable monomer having an aromatic group to the amorphous polyester and polymerizing the shell part. It is thought that a film is formed. Thereby, the influence of the hydrophilic group at the molecular end of the polyester can be suppressed, and the obtained toner is considered to be excellent in image density in a low temperature and low humidity environment. The toner of the present invention is also excellent in heat-resistant storage stability. This is considered to be improved in heat-resistant storage stability while maintaining low-temperature fixability by having a core-shell structure, but has the aromatic group. It is considered that the heat-resistant storage stability is remarkably improved by the addition polymerization resin film.
Hereinafter, each component and process used in the present invention will be described.

[Resin particles (A)]
The resin particles (A) of the present invention are used from the viewpoint of improving the low-temperature fixability of the obtained toner.
The resin particles (A) of the present invention contain a crystalline polyester (a).
<Crystalline polyester (a)>
In the present invention, the crystalline polyester means a ratio between a softening point and a maximum endothermic peak temperature measured by a differential scanning calorimeter (DSC), [(softening point (° C)) / (maximum endothermic peak temperature (° C))]. The crystallinity index defined by is from 0.6 to 1.4, preferably from 0.8 to 1.3 from the viewpoint of low-temperature fixability of the toner, and from 0.9 to 1.2 Is more preferable, and 0.9 to 1.1 is still more preferable.
The crystalline polyester (a) preferably has an acid group at the molecular end from the viewpoint of dispersion stability and emulsification of the resin particle dispersion. Examples of the acid group include a carboxy group, a sulfonic acid group, a phosphonic acid group, and a sulfinic acid. Among these, a carboxy group is preferable from the viewpoint of compatibility between the dispersibility of the resin and the heat-resistant storage stability of the obtained toner.

The melting point of the crystalline polyester (a) is preferably from 50 to 150 ° C., more preferably from 55 to 130 ° C., further preferably from 60 to 90 ° C., further preferably from 60 to 80 ° C., from the viewpoint of heat-resistant storage stability of the toner.
From the same viewpoint, the softening point of the crystalline polyester (a) is preferably 50 to 140 ° C, more preferably 55 to 130 ° C, still more preferably 60 to 110 ° C, and further preferably 60 to 85 ° C.
The acid value of the crystalline polyester (a) is preferably 5 to 30 mgKOH / g, more preferably 10 to 27 mgKOH / g, and more preferably 10 to 25 mgKOH / g, from the viewpoints of dispersion stability and charge amount of the resin particle dispersion of the toner. Is more preferable, 15-25 mgKOH / g is still more preferable, and 15-22 mgKOH / g is still more preferable.
The number average molecular weight of the crystalline polyester (a) is preferably 1,500 to 50,000, more preferably 2,000 to 10,000, and more preferably 2,500 to 50,000, from the viewpoint of low-temperature fixability and heat-resistant storage stability of the toner. 5,000 is more preferable.
In addition, crystalline polyester (a) can be used individually or in combination of 2 or more types.
In the present invention, the crystallinity index, melting point, and softening point of the crystalline polyester (a) are determined by the methods described in the examples. When two or more kinds are used in combination, the melting point of the crystalline polyester (a) having the largest weight ratio in the crystalline polyester (a) contained in the obtained toner is the melting point of the crystalline polyester (a) in the present invention. The melting point. When all have the same ratio, the lowest value is set. A softening point and a number average molecular weight are calculated | required by the method as described in an Example using the mixture mixed by the ratio which uses all the crystalline polyester (a).

The crystalline polyester (a) can be suitably produced by subjecting an acid component and an alcohol component to a polycondensation reaction, preferably in the presence of a catalyst.
Examples of the acid component include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, and trivalent or higher polyvalent carboxylic acids. Among them, aliphatic dicarboxylic acids are used from the viewpoint of heat-resistant storage stability and chargeability of the toner. Acid is preferred.
The acid component includes not only a free acid but also an acid anhydride that generates an acid by reaction and an alkyl ester having 1 to 3 carbon atoms.
The aliphatic dicarboxylic acid preferably has 2 to 18 carbon atoms, more preferably 8 to 12 carbon atoms, from the viewpoint of heat-resistant storage stability of the toner.
Examples of the aliphatic carboxylic acid having 2 to 18 carbon atoms include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, 1,12-dodecanedioic acid. , Azelaic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid and the like. Among them, sebacic acid and 1,12-dodecanedioic acid are preferable, and sebacic acid is more preferable from the viewpoint of heat-resistant storage stability of the toner.
Specific examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid.
Specific examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like.
Specific examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid and pyromellitic acid.
In the carboxylic acid component, the aliphatic carboxylic acid is preferably 80 mol% or more, more preferably 90 mol% or more, and 100 mol% from the viewpoint of improving the heat-resistant storage stability of the toner. Further preferred.
These can be used alone or in combination of two or more.

Examples of alcohol components include aliphatic diols, aromatic diols, hydrogenated bisphenol A, and trihydric or higher polyhydric alcohols. Among them, the crystallinity of polyester is promoted and the low-temperature fixability of toner is improved. From the viewpoint of making them, an aliphatic diol is preferable.
Among the aliphatic diols, α, ω-alkanediol is preferable from the viewpoint of promoting the crystallinity of the polyester and improving the low-temperature fixability of the toner.
The α, ω-alkanediol has preferably 2 to 18 carbon atoms, more preferably 4 to 12 carbon atoms, and still more preferably 6 to 12 carbon atoms from the viewpoint of heat-resistant storage stability of the obtained toner.
Specific examples of the α, ω-alkanediol having 2 to 18 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and the like. From the viewpoint of heat-resistant storage stability, 1,6-hexanediol and 1,9-nonanediol are preferable, and 1,9-nonanediol is more preferable.
The α, ω-alkanediol having 2 to 18 carbon atoms can be used alone or in combination of two or more.
Specific examples of the aromatic diol include alkylene (2 to 3 carbon) oxide adduct (average number of added moles 1 to 16) of bisphenol A.
Specific examples of the trihydric or higher polyhydric alcohol include glycerin and pentaerythritol.

  Although an alcohol component can be used individually or in combination of 2 or more types, from a viewpoint of accelerating the crystallinity of polyester, α, ω-alkanediol having 2 to 18 carbon atoms is 80 to 100 in the alcohol component. It is preferably mol%, more preferably 90 to 100 mol%, and still more preferably 100 mol%.

  A preferable combination of an acid component and an alcohol component is preferably a combination of an aliphatic dicarboxylic acid and an aliphatic diol from the viewpoint of low-temperature fixability, heat-resistant storage stability and chargeability of the obtained toner, and has 4 to 12 carbon atoms. A preferable combination of the α, ω-alkanediol and the aliphatic dicarboxylic acid having 8 to 12 carbon atoms is more preferable.

As the catalyst, the same one as that used for obtaining the amorphous polyester can be used. Among them, a tin compound is more preferable from the viewpoint of the efficiency of the polycondensation reaction, and di (2-ethylhexanoic acid) tin is preferable. Is preferred.
Although there is no restriction | limiting in the usage-amount of a catalyst, 0.01-1 weight part is preferable with respect to 100 weight part of total amounts of an acid component and an alcohol component from a viewpoint of the efficiency of a polycondensation reaction especially, 0.6 part by weight is more preferable.
The polycondensation reaction is preferably performed by adding an acid component and an alcohol component to a reaction vessel and maintaining at 140 to 200 ° C. for 5 to 15 hours, and then adding a catalyst and maintaining at 140 to 200 ° C. for 1 to 5 hours. Then, the reaction is allowed to proceed, and the method of obtaining the crystalline polyester by reducing the pressure to 5.0 to 20 kPa and maintaining it for 1 to 10 hours is preferable.

<Amorphous polyester (c)>
The resin particles (A) of the present invention preferably contain an amorphous polyester (c) from the viewpoint of improving the adhesion with the shell portion of the obtained toner and improving the heat resistant storage stability.
In the present invention, the amorphous polyester (c) is a ratio between a softening point and a maximum endothermic peak temperature measured by a differential scanning calorimeter (DSC), [(softening point (° C.)) / (Maximum endothermic peak temperature ( ° C))] is greater than 1.4, and from the viewpoint of heat resistant storage stability, 1.45 or more is preferable, 1.5 or more is more preferable, and 1.6 or more is even more preferable.
The total amount of the crystalline polyester (a) and the amorphous polyester (c) in the resin particles (A) is preferably 50 to 100 in the resin constituting the resin particles (A) from the viewpoint of improving the low-temperature fixability of the toner. % By weight, more preferably 80 to 100% by weight, still more preferably 90 to 100% by weight. The weight ratio ((a) / (c)) between the crystalline polyester (a) and the amorphous polyester (c) in the resin particles (A) is from the viewpoint of improving the low-temperature fixability and heat-resistant storage stability of the toner. The ratio is preferably 5/95 to 50/50, more preferably 5/95 to 30/70, still more preferably 10/90 to 25/75, and still more preferably 15/85 to 20/80.

The amorphous polyester (c) can be produced by polycondensation reaction between an acid component and an alcohol component.
Examples of the acid component include dicarboxylic acids and trivalent or higher polyvalent carboxylic acids. Among these, dicarboxylic acids are preferable, and dicarboxylic acids and trivalent or higher polyvalent carboxylic acids are more preferably used in combination.
The dicarboxylic acid is preferably at least one of alkyl succinic acid having a branched alkyl group having 9 to 14 carbon atoms, alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms, and aromatic dicarboxylic acid. It is more preferable to use an alkyl succinic acid having a branched alkyl group of -14 and / or an alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms and an aromatic dicarboxylic acid in combination.

Among alkyl succinic acid having a branched alkyl group having 9 to 14 carbon atoms and / or alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms, the affinity with a crystalline polyester is increased, and the low-temperature fixability of the toner is also improved. From the viewpoint of increasing the alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms is preferable.
Further, from the viewpoint of enhancing the affinity with the crystalline polyester and thus enhancing the low-temperature fixability of the toner, the number of carbon atoms of the branched alkyl group or branched alkenyl group is preferably 10-14, more preferably 12-14.
Specific examples of the alkyl succinic acid having a branched alkyl group having 9 to 14 carbon atoms and / or the alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, octenyl succinic acid, From the viewpoint of improving the low-temperature fixability of the toner, dodecenyl succinic acid is preferable.
The branched structure may exist in any part of the alkyl group and the alkenyl group, but a mixture having a plurality of branched structures is preferable from the viewpoint of enhancing the compatibility with the crystalline polyester.
Alkyl succinic acid having a branched alkyl group having 9 to 14 carbon atoms and / or alkenyl succinic acid having a branched alkenyl group having 9 to 14 carbon atoms increases the affinity with the crystalline polyester, thereby lowering the low-temperature fixability of the toner. From the viewpoint of increasing, it is preferably contained in the acid component in an amount of 30 to 60 mol%, more preferably 30 to 50 mol%, still more preferably 35 to 40 mol%.

As the aromatic dicarboxylic acid, phthalic acid, isophthalic acid and terephthalic acid are preferable, and terephthalic acid is more preferable.
The trivalent or higher polyvalent carboxylic acid is preferably a trivalent to pentavalent aromatic carboxylic acid.
Examples of the trivalent to pentavalent aromatic carboxylic acid include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, and the like, and trimellitic acid is preferable from the viewpoint of improving the heat resistant storage stability of the toner. .
From the viewpoint of improving the heat resistant storage stability of the toner, the trivalent to pentavalent aromatic carboxylic acid is preferably contained in the acid component in an amount of 5 to 30 mol%, more preferably 7 to 20 mol%, and still more preferably. 8-15 mol% is contained, More preferably, 9-11 mol% is contained.

  Preferred alcohol components include aromatic diols, and alkylene (2 to 3 carbon) oxide adducts (average number of added moles of 1 to 16) of bisphenol A are preferred.

The number average molecular weight of the amorphous polyester (c) is preferably from 1,000 to 50,000, more preferably from 1,500 to 10,000, from the viewpoint of toner durability, low-temperature fixability and heat-resistant storage stability. 2,000 to 8,000 is more preferable, and 2,000 to 4,000 is more preferable.
The glass transition point of the amorphous polyester (c) is preferably from 50 to 70 ° C., more preferably from 55 to 68 ° C., and still more preferably from 58 to 66 ° C., from the viewpoint of toner durability and heat-resistant storage stability.
The softening point of the amorphous polyester (c) is preferably 70 to 165 ° C, more preferably 70 to 140 ° C, still more preferably 90 to 140 ° C, and further preferably 100 to 130 ° C, from the viewpoint of heat-resistant storage stability of the toner. preferable.
In addition, when using 2 or more types of amorphous polyesters (c), the glass transition point and the softening point are each described in the examples as a mixture of 2 or more types of amorphous polyesters (c). The value obtained by the method.

The acid value of the amorphous polyester (c) is preferably 6 to 35 mgKOH / g, more preferably 10 to 35 mgKOH / g, and still more preferably 15 to 35 mgKOH / g, from the viewpoint of emulsification in the aqueous medium of the resin.
Amorphous polyester (c) may be used alone or in combination of two or more.
In the present invention, the glass transition point, softening point, and crystallinity index of the amorphous polyester (c) are determined by the methods described in the examples. In addition, when using 2 or more types of amorphous polyester (c) together, a glass transition point, a softening point, and a number average molecular weight use the mixture mixed by the ratio which uses all the amorphous polyesters (c). It is calculated | required by the method of an Example description.

<Colorant>
The resin particles (A) may be particles made of resin alone, or may be colorant-containing resin particles containing a colorant, but contain a colorant from the viewpoint of sharpening the particle size distribution of the toner. The colorant-containing resin particles are preferable.
When the resin particles (A) are colorant-containing resin particles, the content of the colorant is based on 100 parts by weight of the resin constituting the resin particles (A) from the viewpoint of image density in a low-temperature and low-humidity environment of the toner. 1 to 20 parts by weight is preferable, and 5 to 10 parts by weight is more preferable.

In addition, when using a coloring agent in this invention, it replaces with or uses as a coloring agent containing resin particle by making it contain in a resin particle (A) as mentioned above, and it is resin in an aqueous medium as a coloring agent particle. Although it may be contained together with the particles (A), as described above, it is preferably contained in the resin particles (A) from the viewpoint of sharpening the particle size distribution of the toner.
As the colorant, pigments and dyes are used, and pigments are preferable from the viewpoint of image density of toner in a low temperature and low humidity environment.
Examples of the pigment include a cyan pigment, a yellow pigment, a magenta pigment, and a black pigment.
The cyan pigment is preferably a phthalocyanine pigment, and more preferably copper phthalocyanine. The yellow pigment is preferably a monoazo pigment, isoindoline pigment, or benzimidazolone pigment, and the magenta pigment is preferably a soluble azo pigment such as a quinacridone pigment or a BONA lake pigment, or an insoluble azo pigment such as a naphthol AS pigment. The black pigment is preferably carbon black.
Specific examples of the dye include acridine series, azo series, benzoquinone series, azine series, anthraquinone series, indico series, phthalocyanine series, and aniline black series.
A coloring agent can be used individually by 1 type or in combination of 2 or more types.

<Manufacture of resin particles (A)>
The resin particles (A) are produced by a method in which the above-mentioned optional components such as the resin containing the crystalline polyester (a) and the colorant are dispersed in an aqueous medium to obtain a dispersion containing the resin particles (A). Is preferred.
Examples of a method for obtaining a dispersion include a method in which a resin or the like is added to an aqueous medium and a dispersion treatment is performed using a disperser or the like, and a method in which an aqueous medium is gradually added to a resin or the like to perform phase inversion emulsification. From the viewpoint of reducing the toner particle size, a method using phase inversion emulsification is preferred. Hereinafter, a method by phase inversion emulsification will be described.

First, the resin containing the crystalline polyester (a), the alkaline aqueous solution, and the optional components such as the colorant are melted and mixed to obtain a resin mixture.
When the resin containing the crystalline polyester (a) is composed of a plurality of resins, a mixture of the crystalline polyester (a) and other resins may be used in advance, It may be obtained by adding at the same time when adding, melting and mixing. For example, when the resin containing the crystalline polyester (a) contains the amorphous polyester (c), the crystalline polyester (a), the amorphous polyester (c), the alkaline aqueous solution, and the above optional components A method of melting and mixing the toner to obtain a resin mixture is preferable from the viewpoint of low-temperature fixability of the toner.
In mixing, it is preferable to add a surfactant from the viewpoint of the emulsion stability of the resin.

  Examples of the alkali in the alkaline aqueous solution include hydroxides of alkali metals such as potassium hydroxide and sodium hydroxide, and ammonia. From the viewpoint of improving the dispersibility of the resin, potassium hydroxide and sodium hydroxide are preferable. . Moreover, 1-30 weight% is preferable, as for the density | concentration of the alkali in aqueous alkali solution, 1-25 weight% is more preferable, and 1.5-20 weight% is still more preferable.

Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants. Among them, nonionic surfactants are preferable from the viewpoint of sufficiently emulsifying the resin, and nonionic interfaces are preferable. It is more preferable to use an active agent and an anionic surfactant or a cationic surfactant in combination, and it is more preferable to use a nonionic surfactant and an anionic surfactant in combination.
When a nonionic surfactant and an anionic surfactant are used in combination, the weight ratio of the nonionic surfactant to the anionic surfactant (nonionic surfactant / anionic surfactant) is sufficient for the resin. From the viewpoint of emulsifying, it is preferably 0.3 to 10, more preferably 0.5 to 5.

Nonionic surfactants include polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, oxyethylene / oxypropylene block copolymers, and the like. From the viewpoint, polyoxyethylene alkyl ethers are preferable.
Examples of polyoxyethylene alkylaryl ethers include polyoxyethylene nonylphenyl ether.
Examples of polyoxyethylene alkyl ethers include polyoxyethylene oleyl ether and polyoxyethylene lauryl ether.
Examples of polyoxyethylene fatty acid esters include polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate, and the like.
Examples of anionic surfactants include dodecyl benzene sulfonate, dodecyl sulfate, alkyl ether sulfate, and the like. From the viewpoint of improving the emulsion stability of the resin, dodecyl benzene sulfonate, alkyl ether sulfate. Is preferred.
As dodecylbenzenesulfonate, an alkali metal salt of dodecylbenzenesulfonate is preferable, and sodium dodecylbenzenesulfonate is more preferable. As dodecyl sulfate, an alkali metal salt of dodecyl sulfate is preferable, and sodium dodecyl sulfate is more preferable. As the alkyl ether sulfate, an alkali metal salt of alkyl ether sulfate is preferable, and sodium alkyl ether sulfate is more preferable.

As a method for obtaining the resin mixture, the resin containing the crystalline polyester (a), the alkaline aqueous solution, and, if necessary, the above optional component, preferably a surfactant, are put in a container, and the resin is stirred while stirring with a stirrer. A method of melting and mixing uniformly is preferable.
When the resin containing the crystalline polyester (a) contains the amorphous polyester (c), the temperature at which the resin is melted and mixed is preferably equal to or higher than the glass transition point, and the homogeneous resin particles are obtained. Therefore, the melting point of the crystalline polyester (a) is more preferable.

Next, an aqueous medium is added to the resin mixture and phase inversion is performed to obtain a dispersion containing resin particles (A).
As the aqueous medium, those containing water as a main component are preferable, and from the viewpoint of stability of phase inversion emulsification and environmental properties, the content of water in the aqueous medium is preferably 80% by weight or more, more preferably 90% by weight or more, 95% by weight or more is more preferable, and 100% by weight is more preferable. As water, deionized water or distilled water is preferably used.
As components other than water, organic solvents that dissolve in water such as aliphatic alcohols having 1 to 5 carbon atoms; dialkyl (carbon numbers 1 to 3) ketones such as acetone and methyl ethyl ketone; and cyclic ethers such as tetrahydrofuran are used. Among these, from the viewpoint of preventing mixing into the toner, an aliphatic alcohol having 1 to 5 carbon atoms that does not dissolve the polyester is preferable, and methanol, ethanol, isopropanol, and butanol are more preferable.

The temperature at which the aqueous medium is added is preferably equal to or higher than the glass transition point of the amorphous polyester (c) when the resin containing the crystalline polyester (a) contains the amorphous polyester (c). From the viewpoint of obtaining resin particles, the melting point of the crystalline polyester (a) is more preferable.
The addition rate of the aqueous medium is from 0.1 to 50 parts by weight / 100 parts by weight of the resin constituting the resin particles (A) until the phase inversion is completed from the viewpoint of making the resin particles have a small particle size. Preferably 0.1 to 30 parts by weight / minute, more preferably 0.5 to 10 parts by weight / minute, and 0.5 to 5 parts by weight / minute. Is more preferable. There is no restriction | limiting in the addition rate of the aqueous medium after phase inversion.
The amount of the aqueous medium used is preferably 100 to 2000 parts by weight, and 150 to 1500 parts by weight with respect to 100 parts by weight of the resin constituting the resin particles (A) from the viewpoint of obtaining uniform aggregated particles in the subsequent aggregation step. More preferred is 150 to 500 parts by weight.
From the viewpoint of the stability and ease of handling of the obtained resin particle dispersion, the solid content concentration is preferably 7 to 50% by weight, more preferably 10 to 40% by weight, still more preferably 20 to 40% by weight, More preferably, it is 25 to 35% by weight. In addition, solid content is the total amount of non-volatile components, such as resin and surfactant.

The volume median particle size (D ₅₀ ) of the resin particles (A) in the dispersion containing the obtained resin particles (A) is 0.02 to 2 μm from the viewpoint of obtaining a toner capable of obtaining a high-quality image. Preferably, 0.02 to 1.5 μm is more preferable, 0.05 to 1 μm is still more preferable, and 0.05 to 0.5 μm is still more preferable. Here, the volume-median particle size (D ₅₀ ) is a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% when calculated from the smaller particle size. It is required by the method of
Further, the coefficient of variation (CV value) (%) of the particle size distribution of the resin particles is preferably 40% or less, more preferably 35% or less, and more preferably 30% from the viewpoint of obtaining a toner capable of obtaining a high-quality image. The following is more preferable, and 28% or less is more preferable. The CV value is a value represented by the following formula, and is specifically obtained by the method described in the examples.
CV value (%) = [standard deviation of particle size distribution (μm) / volume average particle size (μm)] × 100

<Crosslinking>
From the viewpoint of improving the heat resistant storage stability and low-temperature fixability of the toner, it is preferable to crosslink the polyester resin contained in the resin particles (A), and it is more preferable to crosslink with a compound having an oxazoline group.
As the compound having an oxazoline group, a compound containing a plurality of oxazoline groups in the molecule can be used, but a polymer containing an oxazoline group is preferred. The weight average molecular weight is preferably 500 to 2,000,000, more preferably 1,000 to 1,000,000 from the viewpoint of reactivity with the polyester resin.
Examples of commercially available polymers containing oxazoline groups include EPOCROSS WS series (water-soluble type, main chain acrylic), K series (emulsion type, main chain styrene / acrylic) manufactured by Nippon Shokubai Co., Ltd. Also product name).
The content or addition amount of the compound having an oxazoline group is preferably 0.1 to 30 as a solid content with respect to 100 parts by weight of the resin in the resin dispersion, from the viewpoint of crosslinking reactivity with the resin and productivity. Parts by weight, more preferably 0.5 to 20 parts by weight, still more preferably 1 to 10 parts by weight.

  By adding a compound having an oxazoline group and mixing at a predetermined temperature, a part of the resin particles dispersed in the resin dispersion is crosslinked. The temperature at this time is preferably 60 to 100 ° C, more preferably 70 to 98 ° C. The presence of crosslinking of the resin by the compound having an oxazoline group can be confirmed by an amide group generated by crosslinking.

[Releasing agent particles]
The release agent particles preferably contain a surfactant from the viewpoint of aggregation. As the surfactant, an anionic surfactant is preferable, an anionic surfactant containing a carboxy group is more preferable, and sodium polycarboxylate is still more preferable. In the case of using the surfactant, the content is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the release agent, from the viewpoint of aggregation properties and chargeability of the obtained toner, and preferably 0.1 to 5 parts by weight. Part by weight is more preferred.
The volume median particle size of the release agent particles is preferably 0.1 to 1 μm, more preferably 0.1 to 0.7 μm, and more preferably 0.1 to 0.7 μm from the viewpoint of preventing chargeability and hot offset of the obtained toner. 5 μm is more preferable.
The CV value of the release agent particles is preferably 15 to 50%, more preferably 15 to 40%, and still more preferably 15 to 35%, from the viewpoint of the chargeability of the obtained toner.

<Release agent>
Release agents include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicone waxes; fatty acid amides such as oleic acid amide and stearic acid amide; plant waxes such as carnauba wax, rice wax and candelilla wax Animal-based waxes such as beeswax; mineral and petroleum-based waxes such as montan wax, paraffin wax, and Fischer-Tropsch wax. These release agents can be used alone or in combination of two or more, and it is preferable to use in combination of two or more. Further, it is preferable to use a plant-based wax and a mineral / petroleum-based wax from the viewpoint of low-temperature fixability of the toner.
The melting point of the release agent is preferably 60 to 100 ° C., more preferably 60 to 90 ° C., further preferably 75 to 90 ° C., and more preferably 80 to 90 ° C. from the viewpoint of low-temperature fixability and heat-resistant storage stability of the toner. Further preferred. When using 2 or more types together, it is preferable that melting | fusing point of all the mold release agents is 60-90 degreeC from a viewpoint of the low temperature fixability of a toner.
In the present invention, the melting point of the release agent is determined by the method described in the examples. When two or more kinds are used in combination, the melting point of the release agent having the largest weight ratio among the release agents contained in the obtained toner is the melting point of the release agent in the present invention. When all have the same ratio, the lowest value is set.
The amount of the release agent used is preferably 1 to 20 parts by weight, preferably 2 to 15 parts by weight with respect to 100 parts by weight of the resin in the toner, from the viewpoint of improving the releasability of the toner and improving the low-temperature fixability. Is more preferable.

<Manufacture of release agent particles>
The release agent particles are preferably obtained as a dispersion of release agent particles by dispersing the release agent in an aqueous medium.
The dispersion of the release agent particles is preferably obtained by dispersing the release agent and the aqueous medium using a disperser in the presence of a surfactant at a temperature equal to or higher than the melting point of the release agent. As the disperser to be used, a homogenizer, an ultrasonic disperser or the like is preferable.
As the aqueous medium and the surfactant used in the production, those used for obtaining the resin mixture are preferably used.

[Flocculant]
In the present invention, in order to obtain aggregated particles for use as toner particles, the resin particles (A) and the like are aggregated using an aggregating agent to obtain a dispersion of aggregated particles. Aggregation can be efficiently performed by adding a flocculant.
The aggregating agent is preferably an electrolyte, and more preferably a salt, for the purpose of obtaining a toner having a target particle size while preventing excessive aggregation. The valence is preferably 1 to 5, more preferably 1 to 2, and even more preferably 1. That is, a monovalent salt is preferable. As the monovalent salt, an ammonium salt is preferable.
Specific examples of flocculants include quaternary salt cationic surfactants, organic flocculants such as polyethyleneimine; inorganic flocculants such as inorganic metal salts, inorganic ammonium salts, and bivalent metal complexes. It is done.
Examples of the inorganic metal salt include metal salts such as sodium sulfate, 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, ammonium nitrate and the like, and ammonium sulfate is more preferable.
The use amount of the flocculant is preferably 50 parts by weight or less with respect to 100 parts by weight of the resin constituting all the resin particles used (resin particles (A) and (B)), from the viewpoint of chargeability of the toner. More preferably, it is 40 weight part or less, More preferably, it is 30 weight part or less. From the viewpoint of the cohesiveness of the resin particles, the amount is preferably 1 part by weight or more, more preferably 3 parts by weight or more, and further preferably 5 parts by weight or more with respect to 100 parts by weight of the resin constituting all the resin particles. . In consideration of the above points, the amount of monovalent salt used is preferably 1 to 50 parts by weight, more preferably 3 to 40 parts by weight, and more preferably 3 to 40 parts by weight with respect to 100 parts by weight of the resin constituting all the resin particles. Preferably it is 5-30 weight part.

[Resin particles (B)]
The resin particle (B) of the present invention contains an amorphous polyester (b1) having a non-aromatic carbon-carbon unsaturated bond in the main chain. The resin particles (B) form a shell of the core-shell type toner of the present invention, and the resin particles (B) contain amorphous polyester, so that the obtained toner has good heat-resistant storage stability It becomes. In addition, the amorphous polyester (b1) constituting the resin particle (B) has a non-aromatic carbon-carbon unsaturated bond in the main chain, so it is good with the addition polymerizable monomer (b2) having an aromatic group. To polymerize.
The resin particles (B) may contain, as an optional component other than the amorphous polyester (b1), an amorphous polyester other than the amorphous polyester (b1), a crystalline polyester, and a colorant. From the viewpoint of image density under low humidity, it is preferable to contain an amorphous polyester other than the amorphous polyester (b1).

<Amorphous polyester (b1)>
In the present invention, the amorphous polyester means the ratio between the softening point and the maximum peak temperature of the endotherm measured by a differential scanning calorimeter (DSC), [(softening point (° C)) / (maximum endothermic peak temperature (° C)). ] Is larger than 1.4, and from the viewpoint of heat-resistant storage stability, 1.45 or more is preferable, 1.5 or more is more preferable, and 1.6 or more is more preferable.
The amorphous polyester (b1) is an amorphous polyester having a non-aromatic carbon-carbon unsaturated bond in the main chain, and is a raw material monomer (hereinafter simply referred to as “amorphous polyester (b1) ) Is also an alcohol component and a carboxylic acid component, and is obtained by condensation polymerization of an alcohol component and a carboxylic acid component.
Among them, the amorphous polyester (b1) is obtained by polycondensing a carboxylic acid component containing a dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having a carboxy group at both ends and an alcohol component. It is preferable to be obtained.

  As an alcohol component which is a raw material monomer of the amorphous polyester (b1), an alkylene oxide adduct of 2,2-bis (4-hydroxyphenyl) propane, a non-aromatic carbon-carbon unsaturated bond, Examples thereof include diols having hydroxyl groups at both ends, such as polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane. It is preferable to use an alkylene (2 to 3 carbon atoms) oxide adduct (average number of added moles 1 to 16).

As the diol having a non-aromatic carbon-carbon unsaturated bond and having hydroxyl groups at both ends, for example, an alcohol component containing an unsaturated aliphatic diol is preferably used.
Other alcohol components include, for example, ethylene glycol, propylene glycol (1,2-propanediol), glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, allyl alcohol or alkylene thereof (2 to 2 carbon atoms). 4) Oxide adduct (average number of added moles of 1 to 16) and the like. You may use the said alcohol component individually or in combination of 2 or more types.

  The carboxylic acid component which is a raw material monomer of the amorphous polyester (b1) has a non-aromatic carbon-carbon unsaturated bond and a dicarboxylic acid having a carboxy group at both ends, such as an unsaturated aliphatic dicarboxylic acid. And / or an unsaturated alicyclic dicarboxylic acid. By using a dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having carboxy groups at both ends thereof, a carbon-carbon unsaturated bond can be introduced into the main chain of the resulting polyester.

  Examples of dicarboxylic acids (unsaturated aliphatic dicarboxylic acids and unsaturated alicyclic dicarboxylic acids) having a non-aromatic carbon-carbon unsaturated bond and having a carboxy group at both ends include fumaric acid and maleic acid. Unsaturated aliphatic dicarboxylic acid; unsaturated alicyclic dicarboxylic acid such as tetrahydrophthalic acid. From the viewpoint of reactivity, fumaric acid, maleic acid and tetrahydrophthalic acid are preferable, and fumaric acid is more preferable.

  In the carboxylic acid component, the content of the dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having a carboxy group at both ends thereof is preferably 20 to 100 mol%, more preferably 40 to 80 mol%. More preferably, it is 50-70 mol%.

Examples of other carboxylic acids include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; aliphatic dicarboxylic acids such as adipic acid, succinic acid, succinic acid having an alkyl group and / or alkenyl group; cyclohexanedicarboxylic acid Alicyclic dicarboxylic acids such as acids and decalin dicarboxylic acids; Trivalent or higher polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid, and anhydrides of these acids and their alkyl (1 to 3 carbon atoms) esters Etc. From the viewpoint of heat resistant storage stability of the toner, an aromatic dicarboxylic acid is preferable, and terephthalic acid is more preferable. The said carboxylic acid component may be individual or 2 or more types may be contained.
Of the raw material monomers for amorphous polyester (b1), unsaturated aliphatic dicarboxylic acids, unsaturated alicyclic dicarboxylic acids, unsaturated fats are used as raw material monomers having non-aromatic carbon-carbon unsaturated bonds. One or more selected from the group diols may be included, but from the viewpoint of reactivity, it is preferable to include unsaturated aliphatic dicarboxylic acid and / or unsaturated alicyclic dicarboxylic acid, and only unsaturated aliphatic dicarboxylic acid. It is more preferable.

  In the present invention, as the acid group contained in the amorphous polyester (b1), the carboxy group is preferably 90 mol% or more, more preferably 100 mol% of the acid group.

The amorphous polyester (b1) is obtained by, for example, subjecting the alcohol component and the carboxylic acid component to condensation polymerization at a temperature of 180 to 250 ° C. using an esterification catalyst as necessary in an inert gas atmosphere. It can manufacture suitably.
From the viewpoint of heat-resistant storage stability of the toner, the polyester preferably has a sharp molecular weight distribution, and is preferably subjected to polycondensation using an esterification catalyst. Examples of the esterification catalyst include metal compounds such as tin catalyst, titanium catalyst, antimony trioxide, zinc acetate, and germanium dioxide. From the viewpoint of the reaction efficiency of the esterification reaction in the synthesis of the polyester, a tin catalyst is preferable. As the tin catalyst, dibutyltin oxide, di (2-ethylhexanoic acid) tin or the like is preferably used.
In the present invention, since a carboxylic acid having a non-aromatic carbon-carbon unsaturated bond is used, it is preferable to use a radical polymerization inhibitor. As the radical polymerization inhibitor, hydroquinone, 4-t-butylcatechol and the like are preferable.

The number average molecular weight of the amorphous polyester (b1) is preferably from 1,000 to 50,000, more preferably from 1,500 to 10,000, from the viewpoints of toner durability, low-temperature fixability and heat-resistant storage stability. 2,000 to 8,000 are more preferable, and 2,000 to 4,000 are more preferable.
From the viewpoint of heat-resistant storage stability of the toner, the softening point of the amorphous polyester (b1) is preferably 80 to 165 ° C, and the glass transition temperature is preferably 50 to 85 ° C. From the viewpoint of dispersion stability of the resin particle dispersion and heat-resistant storage stability of the toner, the acid value of the amorphous polyester (b1) is 5 to 40 mgKOH / g, preferably 5 to 35 mgKOH / g, more preferably 10 It is -30 mgKOH / g, More preferably, it is 15-25 mgKOH / g.
The glass transition temperature, softening point, and acid value can all be obtained by appropriately adjusting the type of monomer used, the blending ratio, the temperature of condensation polymerization, and the reaction time.
In the present invention, the glass transition point, softening point, and crystallinity index of the amorphous polyester (b1) are determined by the methods described in the examples. In addition, when using 2 or more types of amorphous polyester (b1) together, a glass transition point, a softening point, and a number average molecular weight use the mixture mixed by the ratio which uses all the amorphous polyesters (b1). It is determined by the method described in the examples.
The resin particles (B) may contain a resin other than the amorphous polyester (b1) as a resin. However, the resin particles have an image density under low temperature and low humidity, heat resistant storage stability and low temperature fixability. From the viewpoint, the content of the amorphous polyester (b1) in the resin constituting the resin particles (B) is preferably 50% by weight or more, more preferably 80% by weight or more, and 100% by weight. More preferably.
The resin other than the amorphous polyester (b1) contained in the resin particles (B) is preferably an amorphous polyester other than the amorphous polyester (b1), and the amorphous polyester ( The weight ratio of (b1) to other amorphous polyester ((b1) / (other amorphous polyester)) is preferably 100/0 to 50/50, and 100/0 to 60/40 is preferably 100/0 to 60/40. More preferred is 100/0 to 90/10.

<Manufacture of resin particles (B)>
The resin particles (B) are obtained as a dispersion containing the resin particles (B) by dispersing the resin containing the amorphous polyester (b1) and other optional components such as other amorphous polyesters in an aqueous medium. It is preferable to manufacture by a method.
Examples of a method for obtaining a dispersion include a method in which a resin or the like is added to an aqueous medium and a dispersion treatment is performed using a disperser or the like, and a method in which an aqueous medium is gradually added to a resin or the like to perform phase inversion emulsification. From the viewpoint of reducing the toner particle size, a method using phase inversion emulsification is preferred. Hereinafter, a method by phase inversion emulsification will be described.
In addition, the description similar to manufacture of the resin particle (A) points out to that effect, and is abbreviate | omitted.

First, the resin containing the amorphous polyester (b1), the aqueous alkali solution, and the optional components such as the colorant are melted and mixed to obtain a resin mixture.
When the resin containing the amorphous polyester (b1) is composed of a plurality of resins, a mixture of the amorphous polyester (b1) and another resin may be used in advance. It may be obtained by adding the components at the same time when adding the components, and melting and mixing them.
In mixing, it is preferable to add a surfactant from the viewpoint of the emulsion stability of the resin.
The kind and density | concentration of the alkali in aqueous alkali solution are the same as that of the case of manufacture of the said resin particle (A).
The kind and content of the surfactant are the same as in the production of the resin particles (A).

As a method for obtaining a resin mixture, amorphous polyester (b1), an aqueous alkali solution, preferably a surfactant, and optional components as necessary are placed in a container, and the resin is melted uniformly while stirring with a stirrer. It is preferable to mix them.
The temperature at which the resin is melted and mixed is preferably equal to or higher than the glass transition point of the amorphous polyester (b1).

Next, an aqueous medium is added to the resin mixture and phase inversion is performed to obtain a dispersion containing resin particles (B).
As the aqueous medium, those containing water as a main component are preferable. From the viewpoint of the stability of phase inversion emulsification and environmental properties, the content of water in the aqueous medium is preferably 80% by weight or more, more preferably 90% by weight or more. 95% by weight or more is more preferable, and 100% by weight is more preferable. As water, deionized water or distilled water is preferably used.
About components other than water, it is the same as that of the case of manufacture of the said resin particle (A).

The temperature at which the aqueous medium is added is preferably equal to or higher than the glass transition point of the amorphous polyester (b1) from the viewpoint of obtaining uniform resin particles.
The addition rate and usage amount of the aqueous medium are the same as in the production of the resin particles (A).
The volume median particle size (D ₅₀ ) and the coefficient of variation (CV value) (%) of the particle size distribution of the resin particles (B) in the dispersion containing the obtained resin particles (B) are the above-mentioned resin particles ( This is the same as in the case of manufacturing A).

[Addition polymerizable monomer (b2)]
The addition polymerizable monomer (b2) used in the present invention is an addition polymerizable monomer having an aromatic group. Since the toner obtained using this addition polymerizable monomer (b2) has an aromatic group, it is excellent in heat resistant storage stability and image density in a low temperature and low humidity environment.
Specific examples of the addition polymerizable monomer (b2) include styrene, methyl styrene, α-methyl styrene, β-methyl styrene, t-butyl styrene, chlorostyrene, chloromethyl styrene, methoxy styrene, styrene sulfonic acid or a salt thereof, and the like. And (meth) acrylic acid esters such as benzyl (meth) acrylate (“(meth) acrylic acid” refers to acrylic acid and / or methacrylic acid).
Among these, styrene, methylstyrene, and benzyl (meth) acrylate are preferable, and styrene is more preferable from the viewpoint of image density in a low-temperature and low-humidity environment and heat-resistant storage stability.
In the present invention, other addition polymerizable monomers may be polymerized to the fused particles together with the addition polymerizable monomer (b2).
Examples of other addition polymerizable monomers include (meth) acrylic acid esters having no aromatic group such as alkyl (meth) acrylate (C1-18) and dimethylaminoethyl (meth) acrylate; ethylene Olefins such as propylene and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinylpyrrolidone and the like Examples thereof include N-vinyl compounds. When other addition polymerizable monomers are polymerized together with the addition polymerizable monomer (b2), among the constituent units derived from the addition polymerizable monomer in the toner particles, the addition polymerizable monomer (b2) having an aromatic group is used. The content of the structural unit derived from is preferably 85% by weight or more, more preferably in terms of the addition-polymerizable monomer according to the structural unit, from the viewpoint of image density in a low-temperature and low-humidity environment of the toner and heat-resistant storage stability. Is 90% by weight or more, more preferably 95% by weight or more, and still more preferably 100% by weight.

[Method for producing toner for developing electrostatic latent image]
The method for producing a toner for developing an electrostatic latent image of the present invention includes the following steps (1) to (4).

<Step (1)>
Step (1) is a step of obtaining an aqueous dispersion of aggregated particles (1) by mixing and aggregating resin particles (A) containing crystalline polyester (a) and an aggregating agent in an aqueous medium. .
In this step, the resin particles (A) and the flocculant may be mixed by any method. Examples thereof include a method of adding a flocculant to the dispersion of resin particles (A), a method of adding a dispersion of resin particles (A) to an aqueous medium containing the flocculant, and the like.
In this step, it is preferable to use release agent particles. When the release agent particles are used, first, the resin particles (A) and the release agent particles are mixed in an aqueous medium to obtain a mixed dispersion. It is preferable to obtain.
In addition, it is preferable to mix a coloring agent as an arbitrary component. The colorant may be mixed as separate particles by itself and may be contained in the resin particles (A), but is preferably contained in the resin particles (A) from the viewpoint of controlling aggregation.
There is no restriction | limiting in order of mixing, You may add any in order and may add simultaneously.

In the mixed dispersion, the resin particles (A) are preferably 10 to 40 parts by weight, and more preferably 20 to 30 parts by weight. The aqueous medium is preferably 60 to 90 parts by weight, more preferably 70 to 80 parts by weight.
Moreover, 1-20 weight part is preferable with respect to 100 weight part of resin which comprises a resin particle (A) from a viewpoint of the image density in a low-temperature low-humidity environment, and 3-15 weight part is more preferable. . From the viewpoint of toner releasability and chargeability, the release agent particles are preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total of the resin and the colorant constituting the resin particles (A). 15 parts by weight is more preferable.
The mixing temperature is preferably 0 to 40 ° C. from the viewpoint of aggregation control.

Next, a flocculant is mixed to agglomerate particles in the mixed dispersion to obtain an aqueous dispersion of aggregated particles (1).
As an aggregating method, an aggregating agent is preferably added dropwise as an aqueous solution to a container containing a mixed dispersion. The flocculant may be added at one time, or may be added intermittently or continuously. However, it is preferable to perform sufficient stirring at the time of addition and after completion of the addition. From the viewpoint of controlling aggregation and shortening the toner production time, the dropping time of the aggregating agent is preferably 1 to 120 minutes. Moreover, 0-50 degreeC is preferable from a viewpoint of aggregation control. In addition, from the viewpoint of promoting aggregation, it is preferable to hold the coagulant at 45 to 60 ° C. after dropping, and it is preferable to raise the temperature from 1 to 5 hours from the dropping temperature to the holding temperature.
The volume median particle size of the obtained aggregated particles (1) is preferably 1 to 10 μm, more preferably 2 to 9 μm, and further preferably 3 to 6 μm, from the viewpoint of reducing the particle size of the toner. The CV value is preferably 30% or less, more preferably 28% or less, and still more preferably 25% or less.

<Step (2)>
In step (2), resin particles (B) containing amorphous polyester (b1) having a non-aromatic carbon-carbon unsaturated bond in the main chain are added to the aqueous dispersion of aggregated particles (1). And agglomerating to obtain an aqueous dispersion of aggregated particles (2).
As a method of adding the resin particles (B) to the aqueous dispersion of the aggregated particles (1), a method of adding the resin particles (B) as an aqueous dispersion is preferable.
When the resin particle (B) dispersion is added to the aggregated particle (1) dispersion, the aggregating agent may be further used in order to efficiently attach the resin particle (B) to the aggregated particle (1).
The temperature in the system is 5 ° C. or more lower than the melting point of the crystalline polyester (a) contained in the resin particles (A) and 3 from the glass transition point of the amorphous polyester (c) from the viewpoint of heat-resistant storage stability of the toner. It is preferably lower by at least 5 ° C., more preferably by at least 5 ° C. When the aggregated particles (2) are produced in this temperature range, the low-temperature fixability and heat-resistant storage stability of the obtained toner are improved. The reason for this is not clear, but because the agglomeration of the aggregated particles (2) does not occur, the generation of coarse particles is suppressed, and the crystallinity of the crystalline polyester (a) can be maintained. Conceivable.

The addition amount of the resin particles (B) is such that the weight ratio of the resin particles (B) to the resin particles (A) (resin particles (B) / resin particles (A) from the viewpoint of low-temperature fixability and heat-resistant storage stability of the toner. ) Is preferably 0.1 to 0.9, more preferably 0.1 to 0.5, and still more preferably 0.2 to 0.4.
Compared to the resin particles (A), by adding a small amount of the resin particles (B), the effect of the core portion of the toner of the present invention in which the crystalline polyester (a) and the amorphous polyester (c) are mixed is sufficiently obtained. In addition, the high temperature offset property can be improved, and the heat resistant storage stability can be improved.

  The resin particle (B) dispersion may be added continuously over a certain period of time, may be added at a time, or may be added in a plurality of divided portions. It is preferable to add them continuously or in several divided portions. By adding as described above, the resin particles (B) are likely to selectively adhere to the aggregated particles (1). Among these, it is preferable to add continuously over a certain time from the viewpoint of promoting selective adhesion and the efficiency of production. The time for continuous addition is preferably 1 to 10 hours, and more preferably 2 to 7 hours, from the viewpoint of obtaining uniform aggregated particles (2) and from the viewpoint of shortening the production time. Moreover, 0-60 degreeC is preferable and the dropping temperature is more preferably 30-57 degreeC from a viewpoint of obtaining uniform aggregated particle (2), and a viewpoint of shortening of manufacturing time.

The total amount of the resin particles (B) is added, and aggregation is stopped when the toner particles have grown to an appropriate particle size.
As a particle size for stopping the aggregation, the volume median particle size is preferably 1 to 10 μm, more preferably 2 to 10 μm, still more preferably 3 to 9 μm, and further preferably 4 to 6 μm.
Examples of the method for stopping the aggregation include a method of cooling the dispersion, a method of adding an aggregation stopper, and a method of diluting the dispersion. From the viewpoint of surely preventing unnecessary aggregation, the aggregation stopper A method of stopping the aggregation by adding is preferable.
As the aggregation terminator, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate, alkyl sulfates, and linear alkylbenzene sulfonates. The aggregation terminators can be used alone or in combination of two or more.
The addition amount of the aggregation terminator is preferably 0.1 to 15 parts by weight with respect to 100 parts by weight of the total resin in the system, from the viewpoint of reducing the aggregation terminator and the residual of the aggregation terminator in the toner. Preferably it is 0.1-10 weight part, More preferably, it is 0.1-8 weight part. The aggregation terminator may be added in any form, but is preferably added in an aqueous solution from the viewpoint of productivity.

  The volume median particle size of the aggregated particles (2) obtained in the step (2) is preferably 1 to 10 μm, more preferably 2 to 10 μm, and further preferably 3 to 9 μm from the viewpoint of improving the image quality of the toner. 4 to 6 μm is preferable.

<Step (3)>
Step (3) is a step of fusing the aggregated particles (2) to obtain an aqueous dispersion of fused particles.
In terms of fusing property and toner productivity, in this step, the temperature is preferably at least 10 ° C. lower than the glass transition point of the amorphous polyester (b1), more preferably at least 5 ° C. lower than the glass transition point. In view of improving the heat-resistant storage stability of the toner, the amorphous polyester (b1) is preferably used from the viewpoint of maintaining the temperature preferably at or above the glass transition point, more preferably at a temperature of 5 ° C. or higher than the glass transition point. The temperature is maintained at a temperature not higher than 30 ° C., more preferably not higher than 20 ° C., more preferably not higher than 15 ° C.
In this step, from the viewpoint of particle fusibility, the temperature is preferably 55 to 85 ° C, more preferably 60 to 80 ° C, and still more preferably 65 to 75 ° C.
The holding time in this step (including the temperature rising time to the above holding temperature) is preferably 0.5 to 24 hours, more preferably from the viewpoints of particle fusing property, heat resistant storage stability, chargeability and toner productivity. 0.7 to 18 hours, more preferably 1 to 12 hours.

From the viewpoint of obtaining a high-quality image (from the viewpoint of image density under low temperature and low humidity), the volume median particle size of the fused particles obtained in this step is preferably 2 to 10 μm, more preferably 2 to 8 μm, and more. Preferably it is 2-7 micrometers, More preferably, it is 3-8 micrometers, More preferably, it is 4-6 micrometers.
The volume median particle size of the fused particles obtained in this step is preferably not more than the volume median particle size of the aggregated particles (2). That is, in this step, it is preferable that the fused particles do not aggregate and fuse.

<Step (4)>
Step (4) is a step of adding an addition polymerizable monomer (b2) having an aromatic group to the aqueous dispersion of the fused particles to obtain an aqueous dispersion of toner particles.
As described above, in the present invention, other addition polymerizable monomers may be polymerized to the fused particles together with the addition polymerizable monomer (b2).
Arbitrary polymerization initiators, crosslinking agents, and the like are added to the polymerization in this step as necessary. As a polymerization initiator, a water-soluble initiator is preferable, a radical polymerization initiator is more preferable, and a persulfate is still more preferable. From the viewpoint of allowing polymerization to proceed at a relatively low temperature, sodium persulfate or ammonium persulfate is preferred. Further, it is preferable to use a redox initiator in combination with a reducing agent. As the reducing agent to be combined, ascorbic acid is preferable.
It is preferable to advance the polymerization reaction by heating a mixed solution containing the dispersion of the fused particles and the addition polymerizable monomer (b2). The polymerization temperature depends on the type of polymerization initiator used. For example, when sodium persulfate is used, it is preferably 60 to 100 ° C., more preferably 65 to 80 from the viewpoint of efficiently performing the polymerization reaction. ° C.
The addition amount of the addition polymerizable monomer (b2) in this step is selected from the viewpoint of improving the heat resistant storage stability of the obtained toner and the image density under low temperature and low humidity, and the amorphous polyester (b1) and the addition polymerizable monomer (b2). ) Weight ratio [(b1) / (b2)] is preferably 99/1 to 30/70, more preferably 96/4 to 80/20, and 94/6 to 90/10. More preferably it is.
Further, the addition amount of the addition polymerizable monomer (b2) in this step is used for the addition polymerizable monomer (b2) and the toner from the viewpoint of improving the heat resistant storage stability of the obtained toner and the image density under low temperature and low humidity. The weight ratio [(b2) / total polyester] to the polyester (that is, the total amount of all the polyesters contained in the resin particles (A) and the resin particles (B)) is 0.5 to 10% by weight. Preferably, it is 1.0 to 5% by weight, more preferably 1.5 to 3% by weight.

<Post-processing process>
In the present invention, a post-treatment step may be performed after step (4), and it is preferable to obtain a toner by isolating the toner particles.
Since the toner particles obtained in the step (4) are present in an aqueous medium, it is preferable to first perform solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used.
It is preferable to perform washing after the solid-liquid separation. When a nonionic surfactant is used in the production of the resin particles (A) and (B), it is preferable to remove the added nonionic surfactant, so that it is aqueous below the cloud point of the nonionic surfactant. Washing with a solution is preferred. The washing is preferably performed a plurality of times.
Next, although it is preferable to dry, the temperature at the time of drying is preferably set so that the temperature of the toner particles itself is 5 ° C. or more lower than the melting point of the crystalline polyester, and is set so as to be 10 ° C. or more lower. It is more preferable. As a drying method, it is preferable to use a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like. The water content after drying is preferably adjusted to 1.5% by weight or less, more preferably 1.0% by weight or less, from the viewpoint of chargeability of the toner.

[Electrostatic latent image developing toner]
<Toner>
The toner particles obtained by drying and the like can be used as they are as the toner of the present invention, but it is preferable to use toner particles whose surfaces have been treated as described below.
The softening point of the obtained toner is preferably 60 to 140 ° C., more preferably 60 to 130 ° C., and still more preferably 60 to 120 ° C. from the viewpoint of low-temperature fixability of the toner.
The volume median particle size of the toner is preferably 1 to 10 μm, more preferably 2 to 8 μm, still more preferably 3 to 7 μm, and still more preferably 4 from the viewpoint of image density and productivity in a low temperature and low humidity environment of the toner. ~ 6 μm.
The CV value of the toner is preferably 30% or less, more preferably 27% or less, still more preferably 25% or less, and still more preferably 23% or less, from the viewpoint of image density and productivity in a low temperature and low humidity environment.

<External additive>
In the toner of the present invention, the toner particles can be used as the toner as they are, but it is preferable to use a toner obtained by adding a fluidizing agent or the like to the toner particle surface as an external additive.
Examples of the external additive include inorganic fine particles such as hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, and carbon black, and arbitrary fine particles such as polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Of these, hydrophobic silica is preferred.
When the surface treatment of the toner particles is performed using the external additive, the amount of the external additive added is preferably 1 to 5 parts by weight, more preferably 100 parts by weight of the toner particles before the treatment with the external additive. 1 to 4 parts by weight, more preferably 2 to 4 parts by weight.

  The toner obtained by the present invention can be suitably used as a toner for developing an electrostatic latent image, and can be more suitably used as a one-component developer or mixed with a carrier as a two-component developer. it can.

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

[Acid value of polyester]
It measured according to JIS K0070. However, the measurement solvent was a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Polyester softening point, endothermic maximum peak temperature, melting point, glass transition point and crystallinity index]
(1) Softening point Using a flow tester (manufactured by Shimadzu Corporation, trade name: CFT-500D), a load of 1.96 MPa was applied by a plunger while heating a 1 g sample at a heating rate of 6 ° C / min. And extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of flow tester drop by the flow tester was plotted against the temperature, and the temperature at which half the sample flowed out was taken as the softening point.
(2) Endothermic maximum peak temperature, melting point and glass transition point The temperature was raised to 200 ° C. using a differential scanning calorimeter (manufactured by PerkinElmer, trade name: Pyris 6 DSC), and the temperature was lowered at a rate of 10 ° C./min. The sample cooled to 0 ° C. was measured at a heating rate of 10 ° C./min. Among the observed endothermic peaks, the temperature of the peak having the maximum peak area was defined as the maximum endothermic temperature (1). In the case of crystalline polyester, the peak temperature was taken as the melting point. In the case of an amorphous polyester, when an endothermic peak is observed, the temperature of the peak is measured, and when a step is observed without a peak being observed, the tangent indicating the maximum slope of the curve of the step and the step The glass transition point was defined as the temperature at the intersection with the base line extension line on the high temperature side.
(3) Crystallinity Index Using a differential scanning calorimeter (manufactured by PerkinElmer, trade name: Pyris 6 DSC), a sample cooled from room temperature (20 ° C.) to 0 ° C. at a temperature lowering rate of 10 ° C./min is left still for 1 minute. Then, the temperature was raised to 180 ° C. at a temperature raising rate of 10 ° C./min. Of the observed peaks, the peak temperature with the maximum peak area is defined as the endothermic maximum peak temperature (2), and the crystallinity by (softening point (° C)) / (maximum endothermic peak temperature (2) (° C)). The index was determined.
(4) Number average molecular weight By the following method, molecular weight distribution is measured by gel permeation chromatography, and a number average molecular weight is calculated.
(4-1) Preparation of sample solution A polyester sample is dissolved in a solvent (chloroform) so that the concentration is 0.5 g / 100 ml. Subsequently, this solution is filtered using a fluororesin filter having a mesh of 0.45 μm [manufactured by Advantech Co., Ltd., “DISMIC-25JP”] to remove insoluble components to obtain a sample solution.
(4-2) Measurement of molecular weight distribution Using the following apparatus, a solvent (chloroform) is flowed at a flow rate of 1 ml per minute, and the column is stabilized in a constant temperature bath at 40 ° C. 100 μl of the sample solution is injected therein and measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. In this calibration curve, several types of monodisperse polystyrene (2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁵ , manufactured by Tosoh Corporation), 2.10 × manufactured by GL Sciences, Inc. 10 ³ , 7.00 × 10 ³ , 5.04 × 10 ⁴ ) are used as standard samples.
Measuring apparatus: HLC-8220 GPC (manufactured by Tosoh Corporation)
Analytical column: GMH _XL + G3000H _XL (manufactured by Tosoh Corporation)

[Volume Median Particle Size (D ₅₀ ), Volume Average Particle Size (D _v ), and Particle Size Distribution of Resin Particles and Release Agent Particles]
(1) Measuring device: Laser diffraction particle size measuring machine (Horiba, Ltd., trade name: LA-920)
(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 in an appropriate range.
Further, as the particle size distribution, the CV value (%) was calculated from the volume average particle size (D _v ) and standard deviation displayed by the particle size measuring instrument according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size (D _v )) × 100

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

[Volume Median Particle Size (D ₅₀ ), Volume Average Particle Size (D _v ), and Particle Size Distribution of Toner]
The volume median particle size of the toner was measured as follows.
Measuring instrument: Coulter Multisizer III (trade name, manufactured by Beckman Coulter)
・ Aperture diameter: 50μm
・ 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 (manufactured by Kao Corporation, trade name: Emulgen 109P, HLB: 13.6) was dissolved in the electrolytic solution to obtain a dispersion having a concentration of 5% by weight.
-Dispersion condition: 10 mg of a toner measurement sample is added to 5 mL of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, and then 25 mL of electrolyte is added, and further dispersed for 1 minute with an ultrasonic disperser. A sample dispersion was prepared.
Measurement conditions: The sample dispersion is added to 100 mL of the electrolytic solution to adjust the particle size of 30,000 particles to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured and the particle size distribution thereof. From this, the volume median particle size (D ₅₀ ) was determined.
Further, as the particle size distribution, the CV value (%) was calculated from the volume average particle size (D _v ) and standard deviation displayed by the analysis software according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size (D _v )) × 100

[Charge amount of toner at low temperature and low humidity]
50 cc cylindrical polypropylene bottle (manufactured by Nikko Corporation) with 2.1 g of toner and 27.9 g of silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size: 40 μm) at a temperature of 10 ° C. and a relative humidity of 20% The mixture was shaken 10 times vertically and horizontally, then mixed using a ball mill, and the charge amount at a mixing time of 1 hour was measured using a q / m meter (manufactured by EPPING) to obtain the charge amount.
Measurement equipment, settings, etc. are as follows.
Measuring instrument: q / m-meter manufactured by EPPING
Setting: Mesh size: 635 mesh (aperture: 24 μm, made of stainless steel)
Soft blow, blow pressure (1000V)
Suction time: 90 seconds Charge amount (μC / g) = Total amount of electricity after 90 seconds (μC) / Amount of toner sucked (g)

[Evaluation of image density of toner under low temperature and low humidity]
In a low-temperature and low-humidity environment (10 ° C., 20% relative humidity), a high-quality paper (Fuji Xerox Co., Ltd., J paper A4 size) was used with a commercially available printer (Oki Data Co., Ltd., trade name: MicroLine 5400). A solid image with a toner adhesion amount on the paper of 0.42 to 0.48 mg / cm ² was output to obtain a printed matter.
30 sheets of high-quality paper (Oki Data Co., Ltd., Excellent White Paper A4 size) are laid under the printed material, and the reflected image density of the solid image portion of the printed material is measured by a colorimeter (trade name: SpectroEye, Gretag-Macbeth). , Light emission conditions: standard light source D ₅₀ , observation field of view 2 °, density standard DINNB, absolute white standard), and measured values of three arbitrary points on the image were averaged to obtain an image density. The larger the value of the reflection image density, the better the image density in a low temperature and low humidity environment.

[Evaluation of low-temperature fixability of toner (minimum fixing temperature)]
Using a commercially available printer (trade name: Microline 5400, manufactured by Fuji Xerox Co., Ltd., J paper A4 size), the toner adhesion amount on the paper is 0.42 to 0.48 mg. A solid image of / cm ² was output without fixing at a length of 50 mm, leaving a margin of 5 mm from the top edge of the A4 paper.
Next, the same printer with the temperature-variable fixing device prepared was prepared, the temperature of the fixing device was set to 90 ° C., and fixing was performed at a speed of 1.5 seconds per sheet in the A4 longitudinal direction, thereby obtaining a printed matter.
In the same manner, the temperature of the fixing device was increased by 5 ° C. and fixed, and a printed matter was obtained.
A mending tape (product name: Scotch Mending Tape 810, width 18 mm) is lightly pasted from the margin of the printed material to the image portion, and then a 500 g weight is placed on it, making a round trip at a speed of 10 mm / sec. Pressed. Thereafter, the affixed tape was peeled off from the lower end side at a peeling angle of 180 degrees and a speed of 10 mm / second to obtain a printed matter after the tape was peeled off. 30 sheets of high quality paper (Oki Data Co., Ltd., Excellent White Paper A4 size) is placed under the printed material before and after the tape is applied, and the reflected image density of the fixed image portion before and after the tape is applied to each printed material. , Using a colorimeter (GretagMacbeth, trade name: SpectroEye, light condition; standard light source D ₅₀ , observation field of view 2 °, density standard DINNB, absolute white standard), and calculating the fixing rate using the following formula did.
Fixing rate = (reflected image density after peeling tape / reflected image density before applying tape) × 100
The temperature at which the fixing rate was 90% or more was defined as the minimum fixing temperature. The lower the minimum fixing temperature, the better the low-temperature fixing property.

[Evaluation of heat-resistant storage stability of toner]
20 g of toner was put in a wide-mouthed polybin having an internal volume of 100 ml, sealed, and allowed to stand at a temperature of 50 ° C. for 12 hours. Then, it is allowed to stand for 12 hours or more while being sealed at a temperature of 25 ° C. and cooled. A 250 μm mesh sieve is set on a vibrating table of a powder tester (manufactured by Hosokawa Micron Corporation). The toner (20 g) was placed thereon and vibrated for 30 seconds, and the weight of the toner remaining on the sieve was measured. The smaller the value, the more the toner is not blocked and the better heat resistant storage stability.

[Production of polyester]
Production Example 1
(Production of crystalline polyester X1)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was purged with nitrogen, and 3936 g of 1,9-nonanediol and 4848 g of sebacic acid were added. While stirring, the temperature was raised to 140 ° C., maintained at 140 ° C. for 3 hours, and then heated from 140 ° C. to 200 ° C. over 10 hours. Thereafter, 50 g of di (2-ethylhexanoic acid) tin was added, and the mixture was further maintained at 200 ° C. for 1 hour, and then the pressure in the flask was lowered and maintained at 8.3 kPa for 4 hours to obtain crystalline polyester X1. .

Production Example 2
(Production of amorphous polyester Y1)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 1750 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Put 1625 g of polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, 1145 g of terephthalic acid, 161 g of dodecenyl succinic anhydride, 480 g of trimellitic anhydride, and 10 g of dibutyltin oxide under nitrogen atmosphere While stirring, the temperature was raised to 220 ° C. and maintained at 220 ° C. for 5 hours. After confirming that the softening point measured according to ASTM D36-86 reached 120 ° C., the temperature was lowered to stop the reaction, Amorphous polyester Y1 was obtained.

Production Example 3
(Production of amorphous polyester Y2)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3374 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane (33 g), terephthalic acid (672 g), and dibutyltin oxide (10 g) were added, and the temperature was raised to 230 ° C. with stirring in a nitrogen atmosphere. After maintaining the time, the pressure in the flask was further reduced and maintained at 8.3 kPa for 1 hour. Then, after cooling to 210 ° C. and returning to atmospheric pressure, 696 g of fumaric acid and 0.49 g of tert-butylcatechol were added and maintained at a temperature of 210 ° C. for 5 hours. It was maintained at 3 kPa for 4 hours to obtain amorphous polyester Y2.

Production Example 4
(Production of amorphous polyester Y3)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3528 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane (1404 g), terephthalic acid (1248 g), dodecenyl succinic anhydride (1541 g), and dibutyltin oxide (20 g) were added and stirred at 230 ° C. in a nitrogen atmosphere. The temperature in the flask was maintained at 230 ° C. for 6 hours, and then the pressure in the flask was further reduced and maintained at 8.3 kPa for 1 hour. Then, after cooling to 215 ° C. and returning to atmospheric pressure, 300 g of trimellitic anhydride was added and maintained at 215 ° C. for 1 hour, then the pressure in the flask was further lowered and maintained at 8.3 kPa for 3 hours. As a result, amorphous polyester Y3 was obtained.

Production Example 5
(Production of amorphous polyester Y4)
The inside of a four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 32 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane (2896 g), terephthalic acid (1524 g), glycerin (83 g), and di (2-ethylhexanoic acid) tin (20 g) were added and stirred in a nitrogen atmosphere. However, the temperature was raised to 235 ° C. and maintained at 235 ° C. for 3.5 hours to obtain amorphous polyester Y4.
The physical properties of the above polyester are shown in Table 1.

[Production of resin particles]
Production Example 6
(Production of resin particle dispersion 1)
In a flask equipped with a stirrer, 510 g of amorphous polyester Y3, 90 g of crystalline polyester X1, copper phthalocyanine pigment (trade name: ECB301, manufactured by Dainichi Seika Kogyo Co., Ltd.), polyoxyethylene alkyl ether (nonionic) Surfactant, trade name: Emulgen 150, manufactured by Kao Corporation) 8.5 g, 15 wt% sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: Neoperex G-15, manufactured by Kao Corporation) 80.0 g, 278.5 g of 5 wt% potassium hydroxide aqueous solution was added, and the mixture was heated to 95 ° C. with melting and melted, and mixed at 95 ° C. for 2 hours to obtain a resin mixture.
Next, while maintaining the temperature of the system at 95 ° C., 1222 g of deionized water was added dropwise at a rate of 6 g / min while stirring to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., and stirred at 25 ° C., while stirring the oxazoline group-containing polymer aqueous solution (trade name: Epocross WS-700, manufactured by Nippon Shokubai Co., Ltd., nonvolatile content 25% by weight, acrylic 28 g of the main chain) was added, and then the temperature was raised to 95 ° C. and held at 95 ° C. for 1 hour. Next, the mixture was cooled to 25 ° C., and the obtained emulsion was passed through a 200 mesh (mesh 105 μm) wire mesh to obtain a resin particle dispersion 1. The solid content concentration was 32%, the volume median particle size (D ₅₀ ) of the resin particles was 154 nm, and the CV value was 26%.

Production Example 7
(Production of resin particle dispersion 2)
Resin particle dispersion 2 was obtained in the same manner as in Production Example 6, except that 510 g of amorphous polyester Y3 was replaced with 210 g of amorphous polyester Y1 and 300 g of amorphous polyester Y2. The solid content concentration was 32%, the volume median particle size (D ₅₀ ) of the resin particles was 286 nm, and the CV value was 29%.

Production Example 8
(Production of resin particle dispersion 3)
In Production Example 6, 510 g of amorphous polyester Y3 and 90 g of crystalline polyester X1 were replaced with 210 g of amorphous polyester Y1 and 390 g of amorphous polyester Y2, and 80.0 g of 15% by weight aqueous sodium dodecylbenzenesulfonate 40. Except for changing to 0 g and changing 8.5 g of polyoxyethylene alkyl ether (nonionic surfactant, trade name: Emulgen 150, manufactured by Kao Corporation) to Emulgen 430 6.0 g, the same as Production Example 6 Thus, a resin particle dispersion 3 was obtained. The solid content concentration was 32%, the volume median particle size (D ₅₀ ) of the resin particles was 180 nm, and the CV value was 28%.

Production Example 9
(Production of resin particle dispersion 4)
In a flask equipped with a stirrer, 210 g of amorphous polyester Y1, 390 g of amorphous polyester Y2, polyoxyethylene alkyl ether (nonionic surfactant, trade name: Emulgen 430, manufactured by Kao Corporation) 6 g, 15 40% by weight of sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: Neoperex G-15, manufactured by Kao Corp.) 40 g, 268 g of 5% by weight aqueous potassium hydroxide solution was added and stirred at 95 ° C. The mixture was heated to melt and mixed at 95 ° C. for 2 hours to obtain a resin mixture.
Next, while maintaining the temperature of the system at 95 ° C., 1145 g of deionized water was added dropwise at a rate of 6 g / min while stirring to obtain an emulsion. Next, the obtained emulsion was cooled to 25 ° C., and the obtained emulsion was passed through a 200-mesh wire mesh to obtain a resin particle dispersion 4. The solid content concentration was 31%, the volume median particle size (D ₅₀ ) of the resin particles was 158 nm, and the CV value was 24%.

Production Example 10
(Production of resin particle dispersion 5)
A resin particle dispersion 5 was obtained in the same manner as in Production Example 9, except that 210 g of amorphous polyester Y1 and 390 g of amorphous polyester Y2 were replaced with 600 g of amorphous polyester Y2 in Production Example 9. The solid content concentration was 31%, the volume median particle size (D ₅₀ ) of the resin particles was 142 nm, and the CV value was 24%.

Production Example 11
(Production of resin particle dispersion 6)
A resin particle dispersion 6 was obtained in the same manner as in Production Example 9, except that 390 g of amorphous polyester Y2 was replaced with 390 g of amorphous polyester Y4 in Production Example 9. The solid content concentration was 31%, the volume median particle size (D ₅₀ ) of the resin particles was 142 nm, and the CV value was 24%.

[Manufacture of release agent particles]
Production Example 12
(Production of release agent particle dispersion)
In a beaker, 3.8 g of a sodium acrylate-sodium maleate copolymer aqueous solution (trade name: Poise 521, effective concentration 40% by weight, manufactured by Kao Corporation) as a sodium polycarboxylate aqueous solution was dissolved in 200 g of deionized water. After that, carnauba wax (trade name: Carnauba wax No. 1, melting point 83 ° C.) 5 g and paraffin wax (manufactured by Nippon Seiki Co., Ltd., trade name: HNP-9, melting point) 75 g) was added, and the mixture was melted while maintaining the temperature at 90 to 95 ° C. to obtain a molten mixture in which carnauba wax and paraffin wax were melted together.
The aqueous solution containing the obtained molten mixture was further subjected to a dispersion treatment for 30 minutes with an ultrasonic homogenizer (manufactured by Nippon Seiki Co., Ltd., trade name: US-600T) while maintaining the temperature at 90 to 95 ° C. Then, ion-exchanged water was added thereto to adjust the release agent solid content to 20% by weight to obtain a release agent particle dispersion. The volume median particle size (D ₅₀ ) of the release agent particles in the release agent particle dispersion was 450 nm, and the CV value was 30%.

[Production of toner]
Example 1
(Preparation of Toner 1)
In a four-necked flask equipped with a dehydrating tube, a stirrer, and a thermocouple, 250 g of resin particle dispersion 1, 62 g of deionized water, and 21 g of release agent particle dispersion were mixed at 25 ° C. Next, while stirring the mixture at 25 ° C., an aqueous solution in which 22.8 g of ammonium sulfate was dissolved in 243 g of deionized water was added dropwise at 25 ° C. over 30 minutes, and then the temperature was raised to 55 ° C. over 120 minutes. A dispersion containing aggregated particles having a volume-median particle size of 4.5 μm was obtained. (Process (1))
After the temperature of the aggregated particle dispersion is cooled to 50 ° C., a mixture obtained by mixing 472 g of resin particle dispersion 472 and 22 g of deionized water while raising the temperature of the dispersion at a rate of 1 ° C./hour is used. The solution was added dropwise over 180 minutes to obtain an aggregated particle dispersion having a volume median particle size of 4.9 μm. (Process (2))
Subsequently, after adding an aqueous solution in which 16.0 g of polyoxyethylene lauryl ether sodium sulfate (manufactured by Kao Corporation, trade name: Emar E27C, solid content: 28% by weight) and 625 g of deionized water were added, it took 1 hour. The temperature was raised to 70 ° C. and held at 70 ° C. for 0.5 hour to obtain 4.8 μm fused particles. (Process (3))
The fused particle dispersion was cooled to 25 ° C. with stirring, and the obtained fused particle dispersion was subjected to solid-liquid separation by suction filtration to obtain a wet cake of fused particles. Deionized water was added to the resulting fused particle wet cake, stirred for 30 minutes, and redispersed to obtain a redispersed fused particle dispersion (solid content concentration 7.6%). .
After replacing the inside of the flask containing the fused particle dispersion with nitrogen, 1.10 g of styrene monomer was added dropwise under a nitrogen atmosphere, and the mixture was stirred for 30 minutes after the completion of the addition. Next, with stirring, the temperature was raised to 70 ° C. over 1 hour, 1.72 g of 1% sodium persulfate aqueous solution was added, then 0.18 g of 1% sodium ascorbate aqueous solution was added, and held for 3 hours. A dispersion of toner particles was obtained. Then, it cooled to 25 degreeC. (Process (4))
The obtained dispersion was cooled to 25 ° C., and the solid content of the dispersion was separated by suction filtration, washed with deionized water, and dried to obtain toner particles. (Post-processing process)
To 100 parts by weight of the toner particles, hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., trade name: RY50, number average particle size; 0.04 μm), 2.5 parts by weight, hydrophobic silica (manufactured by Cabot Corporation, product) Name: Cabosea TS720, number average particle size: 0.012 μm) 1.0 part by weight, and polymer fine particles (manufactured by Nippon Paint Co., Ltd., trade name: Finesphere P2000, number average particle size: 0.5 μm) 0.8 A weight part was put into a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain toner 1. (Surface treatment process)
Table 2 shows the physical properties of the toner.

Example 2
(Preparation of Toner 2)
In Example 1, except that 1.10 g of styrene monomer was changed to 0.76 g, 1.72 g of 1% sodium persulfate aqueous solution was changed to 1.18 g, and 0.18 g of 1% sodium ascorbate aqueous solution was changed to 0.12 g. Toner 2 was obtained in the same manner as in Example 1.

Example 3
(Preparation of Toner 3)
In Example 1, except that 1.10 g of styrene monomer was changed to 1.70 g, 1.72 g of 1% sodium persulfate aqueous solution was changed to 2.65 g, and 0.18 g of 1% sodium ascorbate aqueous solution was changed to 0.28 g. Toner 3 was obtained in the same manner as in Example 1.

Example 4
(Preparation of Toner 4)
A toner 4 was obtained in the same manner as in Example 1 except that the resin particle dispersion 4 to be dropped was changed to the resin particle dispersion 5.

Example 5
(Preparation of Toner 5)
A toner 5 was obtained in the same manner as in Example 1 except that the resin particle dispersion 1 was changed to the resin particle dispersion 2.

Comparative Example 1
(Production of Toner 6)
In Example 1, the same process up to the step (3) was performed, and the post-treatment step and the surface were carried out without adding the styrene monomer, sodium persulfate and sodium ascorbate of the step (4) to the obtained fused particles. Processing was performed in the same manner as in Example 1 to obtain Toner 6.

Comparative Example 2
(Preparation of Toner 7)
A toner 7 was obtained in the same manner as in Example 1 except that the resin particle dispersion 4 to be dropped was changed to the resin particle dispersion 6.

Comparative Example 3
(Production of Toner 8)
A toner 8 was obtained in the same manner as in Example 1 except that the resin particle dispersion 1 was changed to the resin particle dispersion 3.

Comparative Example 4
(Preparation of Toner 9)
In Example 1, except that the resin particle dispersion 1 is changed to the resin particle dispersion 2, the process is similarly performed up to the step (1), and the resulting aggregated particles are added with the resin particle dispersion 4 in the step (2). Without performing the steps, the fusion in the step (3), the addition of the styrene monomer, sodium persulfate, and sodium ascorbate in the step (4) are performed, and the post-processing step and the surface treatment are performed in the same manner as in Example 1. 9 was obtained.
Table 2 shows the physical properties and evaluation of the toner.

  From Table 2, it can be seen that the toners of the examples are excellent in both low-temperature fixability and heat-resistant storage stability and image density in a low-temperature and low-humidity environment as compared with the toners of the comparative examples.

  The toner obtained by the production method of the present invention has both low-temperature fixability and heat-resistant storage stability, and is excellent in image density in a low-temperature and low-humidity environment. Therefore, it is suitable as a toner for developing an electrostatic latent image used in electrophotography. Can be used. According to the method of the present invention, a toner having such characteristics can be produced efficiently.

Claims (10)

A method for producing a toner for developing an electrostatic latent image, comprising the following steps (1) to (4):
Step (1): Step of obtaining an aqueous dispersion of aggregated particles (1) by mixing and aggregating the resin particles (A) containing the crystalline polyester (a) and the aggregating agent in an aqueous medium. ): The resin particles (B) containing the amorphous polyester (b1) having a non-aromatic carbon-carbon unsaturated bond in the main chain are added to the aqueous dispersion of the agglomerated particles (1) for aggregation. Step for obtaining an aqueous dispersion of aggregated particles (2) Step (3): Step for obtaining an aqueous dispersion of fused particles by fusing the aggregated particles (2) Step (4): Aqueous of the fused particles A step of adding an addition-polymerizable monomer (b2) having an aromatic group to the dispersion and polymerizing to obtain an aqueous dispersion of toner particles   The electrostatic latent image developing according to claim 1, wherein the weight ratio [(b1) / (b2)] of the amorphous polyester (b1) and the addition polymerizable monomer (b2) is 99/1 to 30/70. Toner manufacturing method.   Amorphous polyester (b1) obtained by polycondensing a carboxylic acid component containing a dicarboxylic acid having a non-aromatic carbon-carbon unsaturated bond and having a carboxy group at both ends and an alcohol component The method for producing a toner for developing an electrostatic latent image according to claim 1, wherein:   The method for producing a toner for developing an electrostatic latent image according to claim 1, wherein in the step (1), the release agent particles are mixed together with the resin particles (A).   The method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 4, wherein the resin particles (A) contain an amorphous polyester (c).   The toner for developing an electrostatic latent image according to claim 5, wherein the weight ratio [(a) / (c)] of the crystalline polyester (a) and the amorphous polyester (c) is 5/95 to 30/70. Manufacturing method.   The crystalline polyester (a) is a crystalline polyester obtained by polycondensation of an α, ω-alkanediol having 4 to 12 carbon atoms and an aliphatic carboxylic acid having 8 to 12 carbon atoms. The method for producing a toner for developing an electrostatic latent image according to any one of the above.   The method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 7, wherein the crystalline polyester (a) has a melting point of 60 to 90 ° C.   The method for producing a toner for developing an electrostatic latent image according to claim 1, wherein the resin particles (A) contain a colorant.   In step (3), the temperature of the system containing the aggregated particles (2) is maintained at a temperature not lower than 5 ° C. lower than the glass transition point of the amorphous polyester (b1), and fused. The method for producing a toner for developing an electrostatic latent image according to any one of claims 1 to 9, which is a step of obtaining.