JP5715478B2 - Method for producing toner for electrophotography - Google Patents

Description

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

In the field of electrophotographic toner, with development of an electrophotographic system, development of a toner corresponding to high image quality and high speed is required.
As a method for controlling the particle size and reducing the particle size in response to higher image quality, an aggregation coalescence method (aggregation fusion) is used to obtain toner by agglomerating and fusing fine resin particles in an aqueous medium. The toner is manufactured by the above method.

For example, Patent Document 1 discloses an electrostatic charge developing toner having at least a crystalline polyester resin and a colorant and having a specific dielectric loss rate for the purpose of improving low-temperature fixability, high density image, and fog suppression. As a method for this, a resin particle dispersion in which binder resin particles containing a crystalline polyester resin are dispersed and a colorant dispersion in which a colorant is dispersed are mixed, and an aggregating agent is added thereto to form aggregated particles. A method for producing a toner is disclosed, which includes an aggregated particle forming step and a fusion / union step in which the aggregated particle is heated and fused and united while adding an acid and a surfactant.
In Patent Document 2, for the purpose of obtaining a developer having high image quality and good particle size distribution, a flocculant is added to a dispersion liquid containing fine particles containing a binder resin and a colorant to cause aggregation and fusion. In the manufacturing method of the developer that forms toner particles, a manufacturing method is disclosed in which each pH of the dispersion before adding the flocculant, the dispersion after adding the flocculant, and the dispersion after fusing satisfies a specific relationship. Yes.
In Patent Document 3, polymer fine particles are obtained by emulsion polymerization in the presence of an emulsifier containing a nonionic surfactant for the purpose of obtaining a toner satisfying low-temperature fixability, offset resistance, developability, and storage stability. The step of forming, the toner base particles and the polymer fine particles are mixed in an aqueous medium and heated to a temperature above the cloud point of the nonionic surfactant, preferably above the glass transition temperature of the polymer fine particles. A method for producing a toner is disclosed which includes a step of attaching polymer fine particles to the surface of the base particles and a step of using the polymer fine particles attached to the base particles as a polymer coating layer.
In Patent Document 4, for the purpose of obtaining toner particles having a high degree of circularity, a step of emulsifying a binder resin containing polyester in an aqueous medium, and the emulsified particles in the obtained emulsion are converted to a glass transition point + 20 ° C. An electron having a step of agglomerating at the following temperature, a step of adding alkyl ether sulfate ester salt or alkyl sulfate ester salt to stop aggregation, and a step of heating the aggregated particles at a specific temperature to unite A method for producing a photographic toner is disclosed.

JP 2009-75342 A JP 2009-122694 A JP-A-9-179336 JP 2008-164808 A

By using a release agent in the toner, the fixing temperature of the obtained toner can be lowered due to its melting characteristics. Thereby, it is possible to reduce the power consumption of the printing press and obtain a toner suitable for high-speed printing. However, the toner containing a release agent causes problems such as disturbance of the dots of the printed matter, which deteriorates the image quality of the printed matter, and lowers the chargeability.
An object of the present invention is to provide an electrophotographic toner having both good low-temperature fixability and chargeability and excellent dot reproducibility of the obtained printed matter, and a method for producing the same.

  The inventors of the present invention have considered the factors affecting the fixing temperature, the chargeability, and the image quality of the printed matter based on the position and state of the resin and the release agent constituting the toner. As a result, it is good by fusing the agglomerated particles containing resin particles and release agent particles and the nonionic surfactant having a specific structure and fusing the agglomerated particles in the aqueous mixture at a specific pH. It has been found that an electrophotographic toner can be obtained which has both low-temperature fixability and chargeability and excellent dot reproducibility of the obtained printed matter.

（式中、Ｒ¹は、水素原子又は炭素数１〜１２のアルキル基を表し、Ｒ²は、水素原子又はメチル基を表し、ｍは平均値が１〜４であり、ＡＯはエチレンオキシ基及び／又はプロピレンオキシ基を表し、ｎは平均値が５〜１００である。）
〔２〕前記〔１〕に記載の製造方法で得られる電子写真用トナー。 That is, the present invention provides the following [1] and [2].
[1] The pH at 25 ° C. of an aqueous mixture containing aggregated particles including resin particles (A) and release agent particles and a nonionic surfactant represented by the following general formula (1) is 2.5. A method for producing an electrophotographic toner, comprising a step of fusing the aggregated particles in the aqueous mixed solution after and / or while adjusting to ~ 5.5.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or a methyl group, m represents an average value of 1 to 4, and AO represents an ethyleneoxy group. And / or a propyleneoxy group, and n has an average value of 5 to 100.)
[2] An electrophotographic toner obtained by the production method according to [1].

  According to the present invention, it is possible to provide an electrophotographic toner having both good low-temperature fixability and chargeability and excellent dot reproducibility of the obtained printed matter, and a method for producing the same.

  The method for producing an electrophotographic toner of the present invention comprises an aqueous mixed solution containing aggregated particles containing resin particles (A) and release agent particles, and a nonionic surfactant represented by the general formula (1). After the pH at 25 ° C. is adjusted to 2.5 to 5.5 and / or while adjusting, the aggregated particles in the aqueous mixed solution are fused.

The reason why the electrophotographic toner obtained by the production method of the present invention has both good low-temperature fixability and chargeability and is excellent in dot reproducibility of the obtained printed matter is not clear, but is as follows. Conceivable.
In the present invention, when the agglomerated particles containing the resin particles (A) and the release agent particles are fused in an aqueous medium, the pH (25 ° C.) of the aqueous mixed solution containing the agglomerated particles is 2.5 to 5. .5 is adjusted. When fusion is performed at a pH in this acidic range, the dispersibility of the resin particles becomes unstable and fusion occurs quickly. Therefore, the fusion is completed before the release agent dissolves or separates. Therefore, even if the release agent is added to the extent that it has an effect on low-temperature fixability, the release agent is exposed to the toner surface. Is suppressed, and the chargeability is considered to be good.
On the other hand, if the pH of the aqueous mixed solution is made weakly acidic, the stability of the particles decreases, and not only the fusion between the resin particles (A) but also the fusion between the aggregated particles is promoted. However, in the present invention, by containing the nonionic surfactant represented by the general formula (1), the nonionic surfactant is present on the surface of the aggregated particles due to the aromatic group having high affinity with the resin. It is considered that a toner having a sharp particle size distribution can be obtained by localizing and preventing fusion of the aggregated particles due to steric repulsion due to the alkyleneoxy moiety. Therefore, since there is no variation between toners during development and transfer, it is considered that the dot reproducibility is excellent and the image quality of the obtained printed matter is also excellent.
As described above, since a toner containing a releasing agent and having a sharp particle size distribution can be obtained, the electrophotographic toner obtained by the production method of the present invention can achieve both good low-temperature fixability and chargeability. It is considered that the obtained printed matter is also excellent in dot reproducibility.
Hereinafter, each component and process used in the present invention will be described.

[Resin particles (A)]
In the present invention, the resin particles (A) preferably contain a crystalline polyester (a). When the resin particles (A) contain the crystalline polyester (a), the content of the crystalline polyester (a) in the resin particles (A) improves the low-temperature fixability of the toner and prevents hot offset. In the resin constituting the resin particles (A), 1 to 50% by weight is preferable, 10 to 50% by weight is preferable, 10 to 30% by weight is further preferable, and 13 to 20% by weight is particularly preferable.

(Crystalline polyester (a))
In the present invention, the crystalline polyester (a) is the ratio between the softening point and the maximum endothermic peak temperature measured by a differential scanning calorimeter (DSC), (softening point (° C)) / (maximum endothermic peak temperature (° C)). The crystallinity index defined in (1) is from 0.6 to 1.4, and from the viewpoint of low-temperature fixability of the toner, 0.8 to 1.3 is preferable, and 0.9 to 1.2. More preferably, the thing of 0.9-1.1 is still more preferable.
The crystalline polyester (a) preferably has an acid group at the molecular end from the viewpoint of emulsifiability. Examples of the acid group include a carboxyl group, a sulfonic acid group, a phosphonic acid group, and a sulfinic acid. Among these, a carboxyl group is preferable from the viewpoint of achieving both the dispersibility of the resin and the 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., from the viewpoint of low-temperature fixability and storage stability of the toner, and from 60 to 80 ° C. Is particularly preferred.
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 particularly preferably 60 to 85 ° C.
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 3,000 to 5,000, from the viewpoint of low-temperature fixability of the toner. Further preferred.
The acid value of the crystalline polyester (a) is preferably 5 to 30 mgKOH / g, more preferably 10 to 27 mgKOH / g, and still more preferably 15 to 25 mgKOH / g, from the viewpoint of the charge amount of the toner.
In addition, crystalline polyester (a) can be used individually or in combination of 2 or more types.
In the present invention, the melting point, softening point and number average molecular weight 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 as a mixture of crystalline polyester (a).

The crystalline polyester (a) can be produced by polycondensation reaction of an acid component and an alcohol component, preferably in the presence of a catalyst, preferably at 180 to 250 ° C.
Examples of the acid component include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, anhydrides of these acids, and alkyl (C1 to C3) esters. Among these, aliphatic dicarboxylic acids are preferable from the viewpoints of low-temperature fixability, storage stability, and chargeability of the toner.
Specific examples of the aliphatic dicarboxylic acid 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 from the viewpoint of low-temperature fixability, storage stability and chargeability 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.
These can be used alone or in combination of two or more.

Examples of the alcohol component include aliphatic diols having 2 to 12 carbon atoms in the main chain, aromatic diols, hydrogenated products of bisphenol A, trihydric or higher polyhydric alcohols, etc. Among them, the crystallinity of polyester is promoted. From the viewpoint of improving the low-temperature fixability of the toner, an aliphatic diol having 2 to 12 main chain carbon atoms is preferred.
Among the aliphatic diols having 2 to 12 main chain carbon atoms, α, ω-linear alkanediol is preferable from the viewpoint of promoting the crystallinity of the polyester and improving the low-temperature fixability of the toner. Those of ˜12 are more preferred.
Specific examples of α, ω-linear alkanediol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane. Examples include diol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, among others, low-temperature fixability and storage of toner. From the viewpoints of stability and chargeability, 1,6-hexanediol and 1,9-nonanediol are preferred.
Specific examples of other aliphatic diols having 2 to 12 main chain carbon atoms include neopentyl glycol and 1,4-butenediol.
Specific examples of the aromatic diol include alkylene (carbon) of bisphenol A such as polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane. Number 2-3) Oxide adduct (average number of added moles 1-16) and the like.
Specific examples of the trihydric or higher polyhydric alcohol include glycerin and pentaerythritol.

  The alcohol component can be used alone or in combination of two or more. From the viewpoint of promoting the crystallinity of the polyester, the alcohol component contains 80 to 100 moles of an aliphatic diol having 2 to 12 carbon atoms in the main chain. %, And more preferably 90 to 100 mol%.

As the catalyst, from the viewpoint of the efficiency of the condensation polymerization reaction, a tin compound, a titanium compound, and the like are preferable, a tin compound is more preferable, and di (2-ethylhexanoic acid) tin, dibutyltin oxide, and the like can be given.
Examples of the titanium compound include titanium diisopropylate bistriethanolamate.
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, and 0.1-0.6 weight part 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) preferably further contain an amorphous polyester (c) from the viewpoint of improving storage stability and chargeability while maintaining low-temperature fixability of the toner and preventing hot offset. 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) improves the low-temperature fixability, storage stability and chargeability of the toner. From the viewpoint of preventing hot offset, 5/95 to 50/50 is preferable, 5/95 to 40/60 is more preferable, 10/90 to 30/70 is more preferable, and 13/87 to 25/75. Is more preferable, and 15/85 to 20/80 is still more preferable.

  As the amorphous polyester (c) that can be contained in the resin particles (A), the same polyester as the amorphous polyester (b) described later can be preferably used. A resin having the same composition as that of the amorphous polyester (b) may be used, or a resin having a different composition may be used. However, it is preferable to use a resin having the same composition from the viewpoints of aggregation control and low-temperature fixability of the toner.

The amorphous polyester (c) can be produced by polycondensation reaction between an acid component and an alcohol component, and preferred acid components and alcohol components are the same as those for the amorphous polyester (b). More than one species may be used. Specifically, preferred acid components include dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, and acid anhydrides and alkyl (C1 to C3) esters thereof. Among them, dicarboxylic acid is preferable.
The dicarboxylic acid is preferably an aromatic dicarboxylic acid, a succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms.
As the aromatic dicarboxylic acid, terephthalic acid is preferable, and as a specific example of succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, dodecenyl succinic acid is preferable, and trivalent or more. As the polyvalent carboxylic acid, trimellitic acid and its acid anhydride are preferable.

Preferable alcohol components include aromatic diols such as polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene-2,2-bis (4-hydroxyphenyl) propane. An alkylene (2 to 3 carbon atoms) oxide adduct (average number of added moles 1 to 16) is preferred.
The glass transition point, softening point, number average molecular weight and acid value of the amorphous polyester (c) are preferably in the same range as the amorphous polyester (b).

  The amorphous polyester (c) may be used alone or in combination of two or more, and contains two types of polyesters having different softening points from the viewpoint of low-temperature fixability, offset resistance and durability of the toner. It is preferable to do. When two types of polyesters having different softening points are polyesters (c-1) and (c-2), respectively, the softening point of one polyester (c-1) is preferably 70 ° C. or higher and lower than 115 ° C., and the other polyester The softening point of (c-2) is preferably 115 ° C. or higher and 165 ° C. or lower. The weight ratio ((c-1) / (c-2)) between the polyester (c-1) and the polyester (c-2) is preferably 10/90 to 90/10, and 50/50 to 90/10. More preferred.

The resin particle (A) is a resin other than the crystalline polyester (a) and the amorphous polyester (c), for example, a styrene-acrylic copolymer, an epoxy resin, a polycarbonate, and a polyurethane as long as the effects of the present invention are not impaired. A resin such as
The resin particles (A) may contain a release agent and a charge control agent as long as the effects of the present invention are not impaired. Moreover, you may contain additives, such as reinforcement fillers, such as a fibrous material, antioxidant, and anti-aging agent, as needed.

In addition, the resin particles (A) may be particles composed only of a resin or may be colorant-containing resin particles containing a colorant. From the viewpoint of sharpening the particle size distribution of the toner, the colorant It is preferable that it is a coloring agent containing resin particle containing a coloring agent.
When the resin particles (A) are colorant-containing resin particles, the content of the colorant is 1 to 20 weights with respect to 100 parts by weight of the resin constituting the resin particles (A) from the viewpoint of toner image density. Part is preferable, and 5 to 10 parts by weight is more preferable.

(Coloring agent)
The colorant used in the present invention may be used as a colorant particle in an aqueous medium by surface treatment or use of a dispersant, or may be used by being contained in resin particles such as resin particles (A). From the viewpoint of sharpening the particle size distribution of the toner, the resin particles (A) are preferably used.
As the colorant, pigments and dyes are used, and pigments are preferable from the viewpoint of image density of the toner.
Specific examples of the pigment include carbon black, inorganic composite oxide, chrome yellow, benzidine yellow, brilliantamine 3B, brilliantamine 6B, Bengal, aniline blue, ultramarine blue, copper phthalocyanine, phthalocyanine green, and the like. Phthalocyanine is preferred.
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.

(Production 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 low-temperature fixability of the toner, 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, but the alkaline aqueous solution and the optional components may be used. 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, cationic surfactants, etc. Among them, nonionic surfactants are preferable, and nonionic surfactants and anionic surfactants or It is more preferable to use a cationic surfactant in combination, and it is more preferable to use a nonionic surfactant and an anionic surfactant in combination from the viewpoint of sufficiently emulsifying the resin.
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, and more preferably 0.5 to 5.

Nonionic surfactants include polyoxyethylene nonylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl aryl ethers such as polyoxyethylene lauryl ether or polyoxyethylene alkyl ethers, polyethylene glycol monolaurate, Examples include polyoxyethylene fatty acid esters such as polyethylene glycol monostearate and polyethylene glycol monooleate, and oxyethylene / oxypropylene block copolymers. Among them, from the viewpoint of emulsion stability of the resin, polyoxyethylene alkyl ether Are preferred.
Specific examples of the anionic surfactant include sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, sodium alkyl ether sulfate, etc. Among them, from the viewpoint of emulsion stability of the resin, sodium dodecyl benzene sulfonate, alkyl ether sulfate Sodium is preferred.
Specific examples of the cationic surfactant include alkyltrimethylammonium chloride.

  The content of the surfactant is preferably 20 parts by weight or less, and preferably 15 parts by weight or less with respect to 100 parts by weight of the resin constituting the resin particles (A) from the viewpoint of obtaining homogeneous resin particles and from the viewpoint of chargeability. More preferably, 0.1-10 weight part is still more preferable, and 0.5-10 weight part is still more preferable.

  As a method for obtaining the resin mixture, from the viewpoint of low-temperature fixability, the resin containing the crystalline polyester (a), the alkaline aqueous solution, and the above optional component, preferably a surfactant, are placed in a container and stirred with a stirrer. A method of melting and uniformly mixing the resin 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).
The aqueous medium preferably contains water as a main component, and from the viewpoint of environmental properties, the water content in the aqueous medium is preferably 80% by weight or more, more preferably 90% by weight or more, and further 95% by weight or more. Preferably, substantially 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 alkyl 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 alkyl alcohol having 1 to 5 carbon atoms that does not dissolve the polyester is preferable, and methanol, ethanol, isopropanol, and butanol are more preferable.

  When the resin containing the crystalline polyester (a) contains the amorphous polyester (c), the temperature at the time of adding the aqueous medium is that of the amorphous polyester (c) from the viewpoint of obtaining uniform resin particles. The glass transition point or higher is preferable, and from the viewpoint of obtaining homogeneous resin particles, the melting point of the crystalline polyester (a) or higher 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 small. 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 of the resin particles (A) in the dispersion containing the obtained resin particles (A) is preferably 0.02 to 2 μm. From the viewpoint of obtaining a high-image toner, 0.02 to 1.5 μm is preferable, 0.05 to 1 μm is more preferable, and 0.05 to 0.5 μm is still more preferable. Here, the volume-median particle size is a particle size at which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle size.
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, still more preferably 30% or less, from the viewpoint of obtaining a high-image toner. 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

[Releasing agent particles]
The release agent particles preferably contain a surfactant from the viewpoint of aggregation. 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, and preferably 0.1 to 5 parts from the viewpoint of aggregation properties and chargeability of the obtained toner. Part by weight is more preferred.
The volume median particle size of the release agent particles is preferably from 0.1 to 1 μm, more preferably from 0.1 to 0.7 μm, and more preferably from 0.1 to 0. 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)
As release agents, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point upon heating; fatty acid amides such as oleic acid amide and stearic acid amide; carnauba wax, rice wax and candelilla wax Plant waxes such as beeswax; animal waxes such as beeswax; mineral / petroleum 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.
The melting point of the release agent is preferably 65 to 100 ° C., more preferably 75 to 95 ° C., further preferably 75 to 90 ° C., and more preferably 80 to 90 ° C. from the viewpoints of low-temperature fixability and storage stability of the toner. ° C is even more preferred.
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 usually preferably 1 to 20 parts by weight with respect to 100 parts by weight of the resin in the toner from the viewpoint of improving the low-temperature fixability by improving the releasability of the toner and from the viewpoint of chargeability. 2 to 15 parts by weight 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.

（式中、Ｒ¹は、水素原子又は炭素数１〜１２のアルキル基を表し、Ｒ²は、水素原子又はメチル基を表し、ｍは平均値が１〜４であり、ＡＯはエチレンオキシ基及び／又はプロピレンオキシ基を表し、ｎは平均値が５〜１００である。） [Nonionic surfactant represented by general formula (1)]
The nonionic surfactant used in the present invention is represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or a methyl group, m represents an average value of 1 to 4, and AO represents an ethyleneoxy group. And / or a propyleneoxy group, and n has an average value of 5 to 100.)

R ¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and from the viewpoint of improving the chargeability of the toner, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable, and a hydrogen atom or a methyl group is more preferable. A hydrogen atom is more preferable.

R ² represents a hydrogen atom or a methyl group, preferably a methyl group, from the viewpoint of sharpening the particle size distribution of the obtained toner and improving the chargeability of the toner. The plurality of R ² may be the same or different, but are preferably the same.
The nonionic surfactant represented by the general formula (1) may be a mixture of compounds in which m is any one of 1 to 4, and m has an average value of 1 to 4, From the viewpoint of improving the chargeability, 2 to 3 is preferable and 2 is more preferable.
In the case where R ² is a hydrogen atom, the average value of m is preferably 2 to 3, and more preferably 3.
The average value of m when R ² is a methyl group is preferably 1 to 2, and more preferably 2.

n represents the average number of added moles of the alkyleneoxy group AO. n has an average value of 5 to 100 mol from the viewpoint of improving the stability of the aggregated particles and the fusing property of the resin particles, improving the chargeability of the obtained toner, and obtaining a high-quality printed matter. 6-50 mol is preferable, 9-30 mol is more preferable, 11-20 mol is still more preferable, 15-19 mol is still more preferable.
A represents an ethylene group (—CH ₂ CH ₂ —) and / or a propylene group (—CH ₂ CH (CH ₃ ) — or —CH (CH ₃ ) CH ₂ —). A preferably contains an ethylene group or an ethylene group and a propylene group, and is preferably an ethylene group. When AO is a propyleneoxy group, the direction of the propylene group is not particularly limited.
When A is an ethylene group, n is an average value from the viewpoint of improving the stability of the aggregated particles and the fusing property of the resin particles, improving the chargeability of the obtained toner, and obtaining a high-quality printed matter. Is 5 to 100 mol, preferably 6 to 50 mol, more preferably 9 to 30 mol, still more preferably 12 to 20 mol, and still more preferably 16 to 19 mol.

  The HLB of the nonionic surfactant represented by the general formula (1) is preferably 10-18, more preferably 12-15.

Preferred nonionic surfactants represented by the general formula (1) include polyoxyethylene (5-100) distyrenated phenyl ether, polyoxypropylene (5-95) polyoxyethylene (95-5) distyrenated phenyl. And ethers and polyoxyethylene (5-100) tribenzylated phenyl ethers.
However, the number in parenthesis shows the average added mole number of an alkyleneoxy group.

  Examples of commercially available nonionic surfactants represented by the general formula (1) include polyoxyethylene (13) distyrenated phenyl ether (trade name: Emulgen A-60, manufactured by Kao Corporation), polyoxyethylene. (18) Distyrenated phenyl ether (trade name: Emulgen A-90, manufactured by Kao Corporation), polyoxyethylene (15) tribenzylated phenyl ether (trade name: Emulgen B-66, manufactured by Kao Corporation) It is done.

[Resin particles (B)]
In the present invention, the resin particles (B) preferably contain an amorphous polyester (b) from the viewpoints of storage stability and chargeability of the toner.
The glass transition point of the resin particle (B) is appropriately determined depending on the glass transition point of the resin such as the amorphous polyester (b) constituting the resin particle (B), the kind and amount of the additive, etc. From the viewpoint of durability, low-temperature fixability and storage stability, it is preferably 45 ° C. or higher, more preferably 45 to 70 ° C., still more preferably 50 to 70 ° C., and still more preferably 55 to 65 ° C.

The resin particles (B) preferably contain 70% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight of the amorphous polyester (b) from the viewpoint of storage stability and chargeability of the toner. % Or more, more preferably 95% by weight or more, and still more preferably substantially 100% by weight.
The resin particles (B) are, together with the amorphous polyester (b), further known resins usually used in toners, such as crystalline polyester (a), styrene acrylic copolymer, epoxy resin, polycarbonate, polyurethane, etc. A resin may be contained.
The resin particles (B) can be obtained by the same method as the method for producing the resin particles (A) described above, but the same alkaline aqueous solution, surfactant, and aqueous medium can be suitably used. .

(Amorphous polyester (b))
In the present invention, the amorphous polyester (b) is a polyester having a crystallinity index of more than 1.4 or less than 0.6.
The amorphous polyester (b) preferably has a crystallinity index of less than 0.6 or more than 1.4 and 4 or less, more preferably less than 0.6, from the viewpoint of low-temperature fixability of the toner. It is 1.5 or more and 4 or less, More preferably, it is less than 0.6 or 1.5 or more and 3 or less, More preferably, it is less than 0.6 or 1.5 or more and 2 or less. The crystallinity index can be appropriately determined depending on the type and ratio of raw material monomers, production conditions (eg, reaction temperature, reaction time, cooling rate), and the like.
As the amorphous polyester (b), an amorphous polyester (b) having an acid group at the molecular end is preferable. Examples of the acid group include a carboxyl group, a sulfonic acid group, a phosphonic acid group, and a sulfinic acid. Among these, a carboxyl group is preferable from the viewpoint of facilitating emulsification of the polyester.

  The amorphous polyester (b) can be produced by a polycondensation reaction between an acid component and an alcohol component in the same manner as the crystalline polyester (a).

Examples of the acid component include dicarboxylic acids, trivalent or higher polyvalent carboxylic acids, acid anhydrides thereof, and alkyl (C 1 -C 3) esters thereof, among which dicarboxylic acids are preferable.
The dicarboxylic acid is preferably an aromatic dicarboxylic acid, a succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, or an aliphatic carboxylic acid.
Specific examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid and the like. Of these, fumaric acid and terephthalic acid are preferable, and fumaric acid is more preferable.
Specific examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, octenyl succinic acid, and the like.
Specific examples of the aliphatic dicarboxylic acid include sebacic acid, fumaric acid, maleic acid, adipic acid, azelaic acid, succinic acid, and cyclohexanedicarboxylic acid.
Specific examples of the trivalent or higher polyvalent carboxylic acid include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, and the like. Among these, from the viewpoint of offset resistance, trimellitic acid and its Acid anhydrides are preferred.
An acid component can be used individually or in combination of 2 or more types.
The amorphous polyester (b) is an acid component containing a trivalent or higher polyvalent carboxylic acid and its acid anhydride or alkyl ester, preferably trimellitic acid or its anhydride, from the viewpoint of offset resistance of the toner. It is preferable to use at least one amorphous polyester (b) obtained using

As an alcohol component, the thing similar to the said alcohol component used for crystalline polyester (a) is mentioned. Among these, it is preferable to use an aromatic diol from the viewpoint of obtaining amorphous polyester, and polyoxypropylene-2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene-2,2-bis ( It is more preferable to use an alkylene (2 to 3 carbon) oxide adduct (average number of added moles of 1 to 16) of bisphenol A such as 4-hydroxyphenyl) propane.
An alcohol component can be used individually or in combination of 2 or more types.

The glass transition point of the amorphous polyester (b) is preferably 50 to 70 ° C., more preferably 55 to 68 ° C., and further preferably 58 to 66 ° C., from the viewpoint of toner durability, low-temperature fixability and storage stability. preferable.
From the same viewpoint, the softening point of the amorphous polyester (b) is preferably 70 to 165 ° C, more preferably 70 to 140 ° C, still more preferably 90 to 140 ° C, and particularly preferably 100 to 130 ° C.
In addition, the glass transition point and softening point in the case of using 2 or more types of amorphous polyester (b) mixed are used for the mixture obtained by mixing the amorphous polyester (b) used in the examples. It is a value obtained by measurement by a method.

The number average molecular weight of the amorphous polyester (b) is preferably 1,000 to 50,000, more preferably 1,000 to 10,000, from the viewpoints of toner durability, low-temperature fixability and storage stability. 2,000 to 8,000 is more preferable.
The acid value of the amorphous polyester (b) 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.

  The amorphous polyester (b) preferably contains two kinds of polyesters having different softening points from the viewpoints of low-temperature fixability, offset resistance and durability of the toner. When two types of polyesters having different softening points are polyesters (b-1) and (b-2), respectively, the softening point of one polyester (b-1) is preferably 70 ° C. or higher and lower than 115 ° C., and the other polyester The softening point of (b-2) is preferably 115 ° C. or higher and 165 ° C. or lower. The weight ratio ((b-1) / (b-2)) between the polyester (b-1) and the polyester (b-2) is preferably 10/90 to 90/10, and 50/50 to 90/10. More preferred.

  In addition, in this invention, what modified | denatured each of crystalline polyester (a), amorphous polyester (b), and (c) can be used in the range which does not impair the effect. Examples of methods for modifying the polyester include grafting with phenol, urethane, epoxy, etc. by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like. Examples thereof include a method of forming a block and a method of forming a composite resin having two or more resin units including a polyester unit.

[acid]
In the present invention, the acid is used to adjust the pH at 25 ° C. of the aqueous mixture used in the step of fusing the aggregated particles to a range of 2.5 to 5.5.
Although there is no restriction | limiting in the acid used, From a viewpoint of adjusting pH efficiently and fuse | melting an aggregated particle efficiently, an inorganic acid is preferable and a mineral acid is more preferable.
Examples of the mineral acid include hydrochloric acid, sulfuric acid, nitric acid and the like, hydrochloric acid and sulfuric acid are preferable, and sulfuric acid is more preferable.
When using an acid, it is preferably used as an aqueous solution, and the concentration is preferably 0.1 to 4N, and more preferably 0.5 to 2N. Here, “N” represents the normality of the acid (the acid concentration mol / liter multiplied by the equivalent amount).

<Method for producing electrophotographic toner>
The method for producing an electrophotographic toner of the present invention comprises an aqueous mixed solution containing aggregated particles containing resin particles (A) and release agent particles, and a nonionic surfactant represented by the general formula (1). After the pH at 25 ° C. is adjusted to 2.5 to 5.5 and / or while adjusting, the aggregated particles in the aqueous mixed solution are fused.
The agglomerated particles used in this step are a step (1) in which resin particles (A), a release agent particle and an aggregating agent are mixed in an aqueous medium to agglomerate to obtain agglomerated particles (1), and a step (1) The aggregated particles (2) obtained by the step (2) of adding the resin particles (B) containing the amorphous polyester (b) to the aggregated particles (1) obtained in (2) to obtain the aggregated particles (2) ) Is preferable.
In the step of fusing the aggregated particles, the aggregated particles (2) are maintained at a temperature not lower than 10 ° C. and not higher than 5 ° C. below the glass transition point of the amorphous polyester (b). The step (4) for obtaining the core-shell particles that are attached is preferable.
Furthermore, although it is an optional step, it has a step (3) of adding the nonionic surfactant represented by the general formula (1) after the step (2) and before the step (4). preferable.
Furthermore, in step (3) and / or step (4), it is preferable to adjust the pH to 2.0 to 6.0 by adding an acid. In particular, the toner has improved chargeability and dot reproducibility. From the viewpoint of obtaining a good and high-quality printed matter, it is preferable to adjust the pH to 2.5 to 5.5 by adding an acid in the step (3).

That is, the method for producing an electrophotographic toner of the present invention preferably includes the following steps (1) to (4).
Step (1): Step of obtaining aggregated particles (1) by mixing resin particles (A), release agent particles and aggregating agent in an aqueous medium and aggregating them Step (2): obtained in step (1) Step of obtaining aggregated particles (2) by adding resin particles (B) containing amorphous polyester (b) to aggregated particles (1) Step (3): represented by general formula (1) Step of adding nonionic surfactant Step (4): Holding the aggregated particles (2) at a temperature not lower than 15 ° C. and not higher than 10 ° C. below the glass transition point of the amorphous polyester (b). The step of obtaining fused core-shell particles Furthermore, preferably, in step (3) and / or step (4), an acid is added to adjust the pH to 2.5 to 5.5. That is, after adjusting the pH of the aqueous mixture to 2.5 to 5.5 in step (3) and / or while adjusting the pH of the aqueous mixture to 2.5 to 5.5 in step (4). Then, the aggregated particles in the aqueous mixed solution are fused to obtain fused core-shell particles.
Hereinafter, each step will be described.

[Step (1)]
Step (1) is a step of obtaining aggregated particles (1) obtained by mixing and aggregating resin particles (A), release agent particles and aggregating agent in an aqueous medium.

In this step, first, the resin particles (A) and the release agent particles are mixed in an aqueous medium to obtain a mixed dispersion.
In addition, although it is preferable to mix a colorant as an arbitrary component, the colorant may be mixed as a separate particle by itself, or may be contained in the resin particles (A). Therefore, it is preferably contained in the resin particles (A).
In this step, resin particles other than the resin particles (A) may be mixed. As resin particles other than the resin particles (A), resin particles containing amorphous polyester are preferable, and those having the same composition as the resin particles (B) are more preferable.
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, and 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 image density, and, as for a coloring agent, 3-15 weight part is more preferable. The release agent particles are preferably 1 to 20 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the total of the resin and the colorant, from the viewpoint of toner releasability and chargeability.
The mixing temperature is preferably 0 to 40 ° C. from the viewpoint of aggregation control.

Next, the particles in the mixed dispersion are aggregated to obtain a dispersion of aggregated particles (1). It is preferable to add a flocculant for efficient aggregation.
As the flocculant, a quaternary salt cationic surfactant, an organic flocculant such as polyethyleneimine; and an inorganic flocculant such as an inorganic metal salt, an inorganic ammonium salt, or a bivalent or higher metal complex are used.
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, more preferably 40 parts by weight or less, and further preferably 30 parts by weight with respect to 100 parts by weight of the resin constituting the resin particles (A), from the viewpoint of chargeability of the toner. Less than parts by weight. 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 still more preferably 5 parts by weight or more with respect to 100 parts by weight of the resin constituting the resin particles (A). is there. In consideration of the above points, the amount of the monovalent salt used is preferably 1 to 50 parts by weight, more preferably 3 to 40 parts by weight with respect to 100 parts by weight of the resin constituting the resin particles (A). More preferably, it is 5-30 weight part.

  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.

  The volume-median particle size of the obtained agglomerated particles (1) is preferably 1 to 10 μm, more preferably 2 to 9 μm from the viewpoint of obtaining a high-quality printed matter with a small particle size and good dot reproducibility. More preferably, it is 3-6 micrometers. The CV value is preferably 30% or less, more preferably 28% or less, and still more preferably 25% or less.

[Step (2)]
Step (2) is a step of obtaining aggregated particles (2) by adding resin particles (B) containing amorphous polyester (b) to aggregated particles (1) obtained in step (1). is there.
In this step, a dispersion of resin particles (B) containing amorphous polyester (b) is added to the dispersion of aggregated particles (1) obtained in step (1) to obtain aggregated particles (1 It is preferable that the resin particles (B) are further adhered to the particles to obtain aggregated particles (2).

Before adding the dispersion containing the resin particles (B) (resin particle (B) dispersion) to the dispersion containing the aggregated particles (1) (aggregated particles (1) dispersion), the aggregated particles (1) An aqueous medium may be added to the dispersion for dilution, and it is preferable to add an aqueous medium. By adding the aqueous medium, the resin particles (B) can be more uniformly attached to the aggregated particles (1).
When the resin particle (B) dispersion is added to the aggregated particle (1) dispersion, the aggregating agent may be used in order to efficiently attach the resin particle (B) to the aggregated particle (1).
As a preferable addition method in the case of adding the resin particle (B) dispersion to the aggregated particle (1) dispersion, a method of simultaneously adding the coagulant and the resin particle (B) dispersion, the coagulant and the resin particle (B ) A method of alternately adding the dispersion liquid, and a method of adding the resin particle (B) dispersion liquid while gradually raising the temperature of the aggregated particle (1) dispersion liquid. By doing in this way, the cohesiveness fall of the aggregated particle (1) and the resin particle (B) by the coagulant | flocculant density | concentration fall can be prevented. From the viewpoint of toner productivity and manufacturing simplicity, it is preferable to add the resin particle (B) dispersion while gradually increasing the temperature of the aggregated particle (1) dispersion.

  The temperature in the system in this step is 5 ° C. or more lower than the melting point of the crystalline polyester (a) contained in the resin particles (A) from the viewpoint of improving the low-temperature fixability, storage stability, and chargeability of the toner. The glass transition point of the quality polyester (b) is preferably 3 ° C. or more, more preferably 5 ° C. or more. When the aggregated particles (2) are produced in this temperature range, the low-temperature fixability and 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 the weight ratio of the resin particles (B) to the resin particles (A) (resin particles (B) / resin from the viewpoints of low-temperature fixability, chargeability improvement and storage stability of the toner. The amount of particles (A)) is preferably 0.3 to 1.5, more preferably 0.3 to 1.0, still more preferably 0.35 to 0.75.

  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 3 to 8 hours, from the viewpoint of obtaining uniform aggregated particles (2) and from the viewpoint of shortening the production time.

  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 adding the nonionic surfactant represented by the general formula (1). In step (3), it is preferable to adjust the pH of the dispersion to 2.5 to 5.5 by adding an acid to the dispersion of aggregated particles (2) obtained in step (2).
The addition amount of the surfactant is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the resin in the system from the viewpoint of suppressing the generation of coarse particles and reducing the remaining of the surfactant. Part by weight is more preferable, and 1.5 to 5 parts by weight is even more preferable.
The temperature at which the surfactant and the acid are added is not limited, but is preferably 10 ° C to 60 ° C, more preferably 20 ° C to 57 ° C, still more preferably 25 ° C to 57 ° C, and further preferably 25 ° C to 45 ° C. is there.
In this step, when an acid is added, the surfactant and the acid may be mixed and added, or may be added separately. When they are added separately, any of them may be added first, but from the viewpoint of suppressing the generation of coarse particles, it is preferable to add an acid after adding a surfactant.
In this step, when an acid is added, the pH of the resulting dispersion is lowered due to the addition of the acid, but the fusion property of the resin particles and the stability of the aggregated particles, that is, the fusion between the aggregated particles. From the viewpoint of preventing the adhesion, that is, sharpening the particle size distribution of the toner and obtaining a high-quality printed matter, it is preferable to add an acid so that the pH of the dispersion is 2.5 to 5.5, 2.5-5.0 is more preferable, it is still more preferable to add an acid so that it may become 2.5-3.5, and it is still more preferable to add an acid so that it may become 2.5-3.0. .

[Step (4)]
In step (4), the agglomerated particles (2) are maintained at a temperature not lower than 15 ° C. and not higher than 10 ° C. below the glass transition point of the amorphous polyester (b) to obtain fused core-shell particles. It is a process, and it is preferable to carry out so that the final pH is in the range of 2.5 to 5.5. If no acid is added in step (3), an acid may be added in this process. preferable.
In this step, the particles in the aggregated particles (2), which are mainly physically attached to each other, are fused and integrated to form core-shell particles.

From the viewpoint of fusing property and toner productivity, in this step, the temperature is at least 15 ° C. lower than the glass transition point of the amorphous polyester (b), preferably at least 13 ° C., more preferably at 11 ° C. It is more preferable to hold at a temperature equal to or higher than a low temperature, and in this step, 10 ° C. higher than the glass transition point of the amorphous polyester (b) from the viewpoint of obtaining good chargeability and obtaining a high-quality printed matter. It is more preferable to hold at a temperature not higher than the temperature, preferably not higher than the glass transition point, more preferably not higher than 3 ° C., more preferably not higher than 7 ° C.
Further, from the viewpoint of storage stability and chargeability of the toner, in this step, the temperature is 5 ° C. or lower, preferably 7 ° C. or lower, more preferably 10 ° C. or lower than the melting point of the crystalline polyester (a). It is more preferable to hold it.
Furthermore, from the viewpoints of fusing property, toner storage stability, chargeability, and toner productivity, in this step, the temperature is 8 ° C. lower than the glass transition point of the resin particles (B) and is higher than the glass transition point. It is preferable to hold at a temperature not higher than 10 ° C.
Further, from the viewpoint of the charging property of the toner, in this step, it is more preferable that the temperature be maintained at a temperature 5 ° C. or more lower than the melting point of the release agent, preferably 7 ° C. .
In this step, from the viewpoint of particle fusibility, the temperature is preferably maintained at 50 to 70 ° C, more preferably 51 to 63 ° C, still more preferably 52 to 58 ° C, still more preferably 54 to 57 ° C.
The pH of the dispersion in this step is preferably 2.5 to 5.5, and preferably 2.5 to 5 from the viewpoint of preventing the fusion of the resin particles and the stability of the aggregated particles, that is, preventing the fusion of the aggregated particles. 0.0 is more preferable, 2.5 to 3.5 is more preferable, and 2.5 to 3.0 is still more preferable.
In this step, when an acid is added, the pH of the dispersion after addition of the acid is 2.5 to 5.5, preferably 2.5 to 5.0, more preferably 2.5 to 3. 5, It is preferable to add an acid so that it may become 2.5-3.0 more preferably.

The holding time in this step is preferably 1 to 24 hours, more preferably 1 to 18 hours, still more preferably 2 to 12 hours, from the viewpoints of particle fusing property, storage stability, chargeability and toner productivity. .
In this step, when an acid is added, it is preferably added within 3 hours after reaching the holding temperature, more preferably within 2 hours, and further within 1 hour. preferable.

In this step, it is preferable to confirm the progress of fusion by monitoring the circularity of the generated core-shell particles. Circularity is monitored by the method described in the examples. When the circularity reaches 0.955 or more, the cooling is performed and the fusion is stopped. The roundness of the finally obtained core-shell particles is 0.955 to 0.995, preferably 0.958 to 0.985, from the viewpoint of obtaining the toner to be cleaned and obtaining a high-quality printed matter. 960 to 0.985 is more preferable, and 0.965 to 0.980 is even more preferable.
The circularity of the fused core-shell particles is preferably 0.01 or more larger than the circularity of the agglomerated particles (2) from the viewpoint of improving the heat-resistant storage stability of the toner and improving the chargeability. More preferably, it is more preferable, and it is further more preferable that it is 0.015 or more.
In this step, it is considered that by increasing the circularity by 0.01 or more, the encapsulation by the shell is improved, the heat resistant storage stability is improved, and the charging property is improved.
BET specific surface area by nitrogen adsorption method of fusing the core-shell particles, 1.0~5.0m ² / g from the viewpoint of chargeability and storage stability of the toner obtained is preferably, 1.0~4.0m ² / g, more preferably, 1.0～3.5M more preferably ² / g, more preferably 1.5~2.5m ² / g.

From the viewpoint of improving the image quality of the toner, the volume-median particle size of the core-shell particles obtained in this step is preferably 2 to 10 μm, more preferably 2 to 8 μm, more preferably 2 to 7 μm, still more preferably 3 to 8 μm. More preferably, it is 4-6 micrometers.
The average particle size of the fused core-shell particles obtained in this step is preferably equal to or less than the average particle size of the aggregated particles (2). That is, in this step, it is preferable that the core shell particles do not aggregate and fuse.

[Post-processing process]
In the present invention, a post-treatment step may be performed after the step (4), and it is preferable to obtain toner particles by isolating the core-shell particles.
Since the core-shell particles obtained in the step (4) are present in the aqueous medium, it is preferable to first perform solid-liquid separation. For solid-liquid separation, a suction filtration method or the like is preferably used.
It is preferable to perform washing after the solid-liquid separation. When a nonionic surfactant is used in the production of the resin particles (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 core-shell particle 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 reducing the amount of toner scattered and charging properties.

<Toner for electrophotography>
(toner)
The toner particles obtained by drying or the like can be used as they are as the toner of the present invention, but it is preferable to use toner particles whose surface has been treated as described below as the toner for electrophotography.
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 glass transition point is preferably 30 to 80 ° C., more preferably 40 to 70 ° C. from the viewpoints of low-temperature fixability, durability, and storage stability.
The circularity of the toner is preferably 0.955 to 0.985, more preferably 0.955 to 0.980, and still more preferably 0.965, from the viewpoint of storage stability of the toner, cleaning properties, and obtaining a high quality image. ~ 0.980. The circularity of the toner particles can be measured by the method described later. The circularity of the toner particles is a value obtained by a ratio of the circumference of the circle equal to the projected area / the circumference of the projected image. The more circular the particles are, the closer the circularity is to 1. .
The toner obtained by the method of the present invention has a core-shell structure, and amorphous polyester (b) is preferably contained in the shell part in an amount of 50 to 100% by weight, more preferably 70 to 100% by weight, and still more preferably 90 to 90%. Contains 100% by weight.
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 to 6 μm, from the viewpoint of high image quality and productivity of the toner.
The CV value of the toner is preferably 30% or less, more preferably 27% or less, still more preferably 25% or less, and further preferably 22% or less, from the viewpoint of high image quality and productivity.

(External additive)
In the electrophotographic toner of the present invention, the toner particles can be used as the toner as they are, but it is preferable to use a toner obtained by adding a fluidizing agent or the like to the toner particle surface as an external additive.
Examples of the external additive include 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 3.5 parts by weight, more preferably 1 to 3 parts by weight.

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

  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 chloroform.

[Polyester softening point, endothermic maximum peak temperature, melting point and glass transition point]
(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 Using a differential scanning calorimeter (manufactured by PerkinElmer, trade name: Pyris 6 DSC), the temperature is raised to 200 ° C., and the temperature lowering rate is 50 ° 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 peak temperature. 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.

[Glass Transition Point of Resin Particle (B) Containing Amorphous Polyester (b)]
When measuring the glass transition point of the resin particles (B), the solvent was removed from the dispersion of resin particles (B) by lyophilization, and the obtained solid was measured by the above method.
The lyophilization of the resin particle (B) dispersion is performed using a freeze dryer (manufactured by Tokyo Rika Kikai Co., Ltd., trade names: FDU-2100 and DRC-1000), and 30 g of the resin particle (B) dispersion is -25. Vacuum drying was performed at 1 ° C. for 1 hour, −10 ° C. for 10 hours, and 25 ° C. for 4 hours, and the water content was dried to 1% by weight or less. The moisture content was determined by using an infrared moisture meter (trade name: FD-230, manufactured by Kett Scientific Laboratory), drying 5 g of the sample at a drying temperature of 150 ° C. and a measurement mode 96 (monitoring time 2.5 minutes). / Fluctuation range 0.05%).
The method for measuring the glass transition point was the same as the method for measuring the glass transition point of polyester.

[Number average molecular weight of polyester]
The molecular weight distribution was measured by gel permeation chromatography and the number average molecular weight was calculated by the following method.
(1) Preparation of sample solution Polyester was dissolved in chloroform so that the concentration was 0.5 g / 100 ml. Subsequently, this solution was filtered using a fluororesin filter having a pore size of 2 μm (manufactured by Sumitomo Electric Industries, Ltd., trade name: FP-200) to remove insoluble components to obtain a sample solution.
(2) Molecular weight distribution measurement Chloroform was allowed to flow as a lysis solution at a flow rate of 1 ml / min, and the column was stabilized in a constant temperature bath at 40 ° C. 200 μl of the sample solution was injected there for measurement. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. In the calibration curve at this time, several types of monodisperse polystyrene (monodisperse polystyrene manufactured by Tosoh Corporation); molecular weights 1.11 × 10 ⁶ , 3.97 × 10 ⁵ , 1.89 × 10 ⁵ , 9.89 × 10 ⁴ , 1.71 × 10 ⁴ , 9.49 × 10 ³ , 5.87 × 10 ³ , 1.01 × 10 ³ , 5.00 × 10 ² ) were used as standard samples.
Measuring apparatus: HPLC LC-9130NEXT (trade name, manufactured by Nippon Analytical Industries, Ltd.)
Analytical column: JAIGEL-2.5-HA + JAIGEL-MH-A (both trade names, manufactured by Nippon Analytical Industries, Ltd.)

[Volume Median Particle Size (D ₅₀ ) and Particle Size Distribution of Resin Particles, 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 temperature at which the absorbance falls within an appropriate range. The CV value was calculated according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) × 100

[Solid content concentration of resin particle dispersion]
Using an infrared moisture meter (FD-230), 5 g of the resin particle dispersion was measured at a drying temperature of 150 ° C. in a measurement mode 96 (monitoring time 2.5 minutes / variation width 0.05%). 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 ) and Particle Size Distribution of Toner (Particles) and Aggregated Particles]
The volume median particle size of the toner (particles) was measured as follows.
-Measuring machine: 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 (trade name, Emulgen 109P, HLB: 13.6, manufactured by Kao Corporation) 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.
The CV value (%) was calculated according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) × 100
The volume-median particle size of the agglomerated particles and the agglomerated particles (2) are the same when the agglomerated particle dispersion and the agglomerated particles (2) are used as the sample dispersion in the measurement of the volume-median particle size of the toner (particles). Measured.

[Core shell particle, toner circularity]
-Preparation of dispersion: The dispersion of core-shell particles was diluted with deionized water so that the solid content concentration of the core-shell particles was 0.001 to 0.05%, and used as a sample dispersion. The toner dispersion was prepared by adding 50 mg of toner to 5 ml of 5 wt% polyoxyethylene lauryl ether (Emulgen 109P) aqueous solution, dispersing for 1 minute with an ultrasonic disperser, adding 20 ml of distilled water, A toner dispersion was obtained by dispersing for 1 minute using an ultrasonic disperser.
Measurement device: Flow-type particle image analyzer (manufactured by Sysmex Corporation, trade name: FPIA-3000)
・ Measurement mode: HPF measurement mode

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

[Evaluation of low-temperature fixability of toner]
Using a commercially available printer (trade name: ML5400, manufactured by Oki Data Co., Ltd.) on high-quality paper (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 being fixed 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 a variable temperature fixing device was prepared. The temperature of the fixing device was set to 100 ° C., and fixing was performed at a speed of 1.5 seconds per sheet in the A4 longitudinal direction to obtain a printed matter.
In the same manner, the temperature of the fixing device was increased by 5 ° C., and the fixing was performed to obtain a printed matter.
A 500 g weight is applied to the margin at the top of the printed image, after lightly pasting a piece of mending tape (product name: Scotch mending tape 810, width 18 mm) cut to a length of 50 mm. It was loaded and pressed once and again at a speed of 10 mm / sec. 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. , Measured using a colorimeter (GretagMacbeth, trade name: SpectroEye, light emission condition: standard light source D ₅₀ , observation field of view 2 °, density standard DINNB, absolute white standard) Calculated.
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.

[Dot reproducibility evaluation of printed matter]
The printer used was Microline 5400 (resolution 600 × 600 dpi) manufactured by Oki Data Corporation, and J paper manufactured by Fuji Xerox Co., Ltd. was used as the print medium. A halftone image of 2 by 2 (2 dots and 2 spaces) is output as an unfixed image using the above printer as a print image, and the output unfixed image is output using an optical microscope VHX-100 (manufactured by Keyence Corporation). 5 × 5 dots were enlarged and observed. A dot having a portion where the underlying paper is exposed was regarded as a missing dot, and the degree of missing a dot was evaluated according to the following evaluation criteria based on the number of dots. The dot reproducibility of the printed material indicates that the smaller the missing dots, the better.
A ... No more than one dot is missing out of 25 dots.
B: Out of 25 dots, the number of missing dots is 2 or more and 5 or less.
C: Out of 25 dots, there are 6 or more missing dots.

[Evaluation of toner chargeability]
A 50 cc cylindrical polypropylene bottle (Nikko Corporation) containing 2.1 g of toner and 27.9 g of a silicone ferrite carrier (manufactured by Kanto Denka Kogyo Co., Ltd., average particle size: 40 μm) at 25 ° C. and 50% RH. ) And shaken 10 times vertically and horizontally, and then mixed for 1 hour using a tumbler mixer. The charge amount at that time was measured using a q / m meter (manufactured by EPPING) to obtain the charge amount. The higher the absolute value of the charge amount, the better the chargeability.
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 (600V)
Suction time: 90 seconds Charge amount (μC / g) = Total amount of electricity after 90 seconds (μC) / Amount of toner sucked (g)

[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. Then, the pressure in the flask was lowered and maintained at 8.3 kPa for 4 hours to obtain crystalline polyester X1. . Table 1 shows the softening point, melting point, crystallinity index, number average molecular weight, and acid value of the obtained crystalline polyester X1.

Production Example 2
(Production of crystalline polyester X2)
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 2419 g of 1,6-hexanediol and 4957 g of 1,12-dodecanedioic 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, 30 g of di (2-ethylhexanoic acid) tin was added, and the mixture was further maintained at 200 ° C. for 1 hour. Then, the pressure in the flask was lowered and maintained at 8.3 kPa for 3 hours to obtain crystalline polyester X2. . Table 1 shows the softening point, melting point, crystallinity index, number average molecular weight, and acid value of the obtained crystalline polyester X2.

Production Example 3
(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 3322 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane (31 g), terephthalic acid (662 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 lowered and maintained at 8.0 kPa for 1 hour. After returning to atmospheric pressure, the mixture was cooled to 190 ° C., 685 g of fumaric acid and 0.49 g of tert-butylcatechol were added, maintained at 190 ° C. for 1 hour, and then heated to 210 ° C. over 2 hours. Further, the pressure in the flask was lowered and maintained at 8.0 kPa for 4 hours to obtain amorphous polyester Y1. Table 1 shows the softening point, glass transition point, crystallinity index, number average molecular weight, and acid value of the obtained amorphous polyester Y1.

Production Example 4
(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 1750 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, A nitrogen atmosphere containing 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 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 Y2 was obtained. Table 1 shows the softening point, glass transition point, crystallinity index, number average molecular weight, and acid value of the obtained amorphous polyester Y2.

Production Example 5
(Production of amorphous polyester Y3)
The inside of the four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3004 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 996 g of fumaric acid, 2 g of tert-butylcatechol and 8 g of dibutyltin oxide were added, heated to 210 ° C. over 5 hours with stirring in a nitrogen atmosphere, held at 210 ° C. for 2 hours, and then at 8.3 KPa. The reaction was continued until the desired softening point was reached to obtain amorphous polyester Y3. Table 1 shows the softening point, glass transition point, crystallinity index, number average molecular weight, and acid value of the obtained amorphous polyester Y3.

[Production of resin particles and release agent particles]
Production Example 6
(Preparation of resin particle dispersion (A-1))
In a flask equipped with a stirrer, 90 g of crystalline polyester X1, 300 g of amorphous polyester Y1, 210 g of amorphous polyester Y2, 45 g of copper phthalocyanine pigment (trade name: ECB301, manufactured by Dainichi Seika Kogyo Co., Ltd.), polyoxy Ethylene alkyl ether (nonionic surfactant, trade name: Emulgen 150, manufactured by Kao Corporation) 8.5 g, 15% by weight sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: Neoperex G-15) 80 g of Kao Co., Ltd.) and 266 g of 5 wt% aqueous potassium hydroxide solution were added, and the mixture was heated to 98 ° C. with melting and melted and mixed at 98 ° C. for 2 hours to obtain a resin mixture.
Next, 1116 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 a resin particle dispersion (A-1) was obtained through a 200-mesh (mesh 105 μm) wire mesh. Table 2 shows the solid content concentration, volume median particle size, and CV value of the obtained resin particle dispersion.

Production Example 7
(Preparation of resin particle dispersion (A-2))
In a flask equipped with a stirrer, 90 g of crystalline polyester X2, 300 g of amorphous polyester Y1, 210 g of amorphous polyester Y2, copper phthalocyanine pigment (trade name: ECB301, manufactured by Dainichi Seika Kogyo Co., Ltd.), polyoxy Ethylene alkyl ether (nonionic surfactant, trade name: Emulgen 150, manufactured by Kao Corporation) 8.5 g, 15% by weight sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: Neoperex G-15) 80 g of 5% by weight potassium hydroxide aqueous solution was added, and the mixture was heated to 98 ° C. with melting and melted, and mixed at 98 ° C. for 2 hours to obtain a resin mixture.
Next, 1109 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 a resin particle dispersion (A-2) was obtained through a 200-mesh (mesh 105 μm) wire mesh. Table 2 shows the solid content concentration, volume median particle size, and CV value of the obtained resin particle dispersion.

Production Example 8
(Preparation of resin particle dispersion (B-1))
In a flask equipped with a stirrer, 390 g of amorphous polyester Y1, 210 g of amorphous polyester Y2, polyoxyethylene alkyl ether (nonionic surfactant, trade name: Emulgen 430, manufactured by Kao Corporation), 6 g, 15 weight 40% of sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant, trade name: Neoperex G-15, manufactured by Kao Corporation) and 268 g of 5 wt% potassium hydroxide were added, and the temperature was raised to 95 ° C while stirring. The mixture was melted and mixed at 95 ° C. for 2 hours to obtain a resin mixture.
Next, 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 is cooled to 25 ° C., passed through a 200-mesh wire mesh, deionized water is added to adjust the solid content to 23.5% by weight, and a resin particle dispersion (B -1) was obtained. Table 2 shows the solid content concentration, volume median particle size, and CV value of the obtained resin particle dispersion.

Production Example 9
(Preparation of resin particle dispersion (B-2))
In a flask equipped with a stirrer, 600 g of amorphous polyester Y3, 6 g of polyoxyethylene alkyl ether (nonionic surfactant, trade name: Emulgen 430, manufactured by Kao Corporation), 15% by weight sodium dodecylbenzenesulfonate aqueous solution (Anionic surfactant, trade name: Neoperex G-15, manufactured by Kao Corporation) 40 g and 247 g of 5 wt% potassium hydroxide were added, and the mixture was heated to 95 ° C. and melted with stirring. For 2 hours to obtain a resin mixture.
Next, 1165 g of deionized water was added dropwise at a rate of 6 g / min while stirring to obtain an emulsion. Next, the obtained emulsion is cooled to 25 ° C., passed through a 200-mesh wire mesh, deionized water is added to adjust the solid content to 23.5% by weight, and a resin particle dispersion (B -2) was obtained. Table 2 shows the solid content concentration, volume median particle size, and CV value of the obtained resin particle dispersion.

Production Example 10
(Production of release agent particle dispersion)
In a beaker having an internal volume of 1 liter, 480 g of deionized water, 4.29 g of alkenyl (mixture of hexadecenyl group and octadecenyl group) dipotassium succinate (trade name: Latemulu ASK, Kao Corporation, effective concentration 28 wt%), 120 g of carnauba wax (produced by Hiroyuki Kato, melting point 85 ° C., acid value 5 mgKOH / g) was added and stirred. While maintaining the mixture at 90 to 95 ° C., the mixture was subjected to a dispersion treatment for 30 minutes using an ultrasonic disperser (trade name: Ultrasonic Homogenizer 600W, manufactured by Nippon Seiki Seisakusho Co., Ltd.), and then cooled to 25 ° C. Then, deionized water was added to adjust the solid content to 20% by weight to obtain a release agent particle dispersion. The volume median particle size of the release agent particles was 0.494 μm, and the CV value was 34%.

[Production of toner]
Example 1
(Preparation of Toner A)
<Step (1): Production of Aggregated Particle (1)>
Into a four-necked flask with an internal volume of 5 liters equipped with a dehydrating tube, a stirrer and a thermocouple, 250 g of resin particle (A-1) dispersion, 67.4 g of deionized water, and 42 g of release agent particle dispersion are heated. Mixed at 25 ° C. Next, while stirring the mixture, an aqueous solution in which 21 g of ammonium sulfate was dissolved in 219 g of deionized water was added dropwise at 25 ° C. over 5 minutes, and then the temperature was raised to 55 ° C. so that the volume-median particle size of the aggregated particles was 4 It was kept at 55 ° C. until it became 3 μm to obtain aggregated particles (1).
<Step (2): Production of Aggregated Particle (2)>
41 g of deionized water was added to the aggregated particle (1) dispersion (total amount) obtained in step (1), and the temperature of the aggregated particle (1) dispersion was cooled to 49 ° C. Next, while heating the dispersion at 49 ° C. at a rate of 1.6 ° C. per hour, 158.5 g of the resin particle (B-1) dispersion was dropped at a rate of 0.5 ml per minute to obtain aggregated particles (2). A dispersion was obtained. Table 3 shows the volume-median particle size, circularity, and pH of the dispersion of the obtained aggregated particles (2). Moreover, the temperature of the dispersion liquid after completion | finish of dripping was 57 degreeC.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 55 ° C. and held at 55 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.
<Washing / Drying / External Addition Process>
Next, the dispersion was cooled to 25 ° C., and the solid content was separated by suction filtration while being kept at 25 ° C., washed with deionized water, and dried at 33 ° C. to obtain toner particles. Table 3 shows the circularity, the BET specific surface area, and the volume-median particle size of the obtained toner. 100 parts by weight of the toner particles, 2.5 parts by weight of hydrophobic silica (trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.04 μm), and hydrophobic silica (trade name: Cabo Seal TS720, Cabot Corporation) Manufactured, average particle size: 0.012 μm) was put in a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain toner A. Table 3 shows the evaluation properties of the obtained toner and the evaluation of the toner.

Example 2
(Preparation of Toner B)
<Step (1): Production of Aggregated Particle (1)>
Into a four-necked flask with an internal volume of 5 liters equipped with a dehydrating tube, a stirrer, and a thermocouple, 250 g of resin particle (A-2) dispersion, 55.9 g of deionized water, and 41 g of release agent particle dispersion are heated. Mixed at 25 ° C. Next, while stirring the mixture, an aqueous solution in which 20 g of ammonium sulfate was dissolved in 211 g of deionized water was dropped at 25 ° C. over 5 minutes, and then the temperature was raised to 55 ° C. so that the volume-median particle size of the aggregated particles was 4 It was kept at 55 ° C. until it became 3 μm to obtain aggregated particles (1).
<Step (2): Production of Aggregated Particle (2)>
39 g of deionized water was added to the aggregated particle (1) dispersion (total amount) obtained in step (1), and the temperature of the aggregated particle (1) dispersion was cooled to 49 ° C. Next, 152.7 g of the resin particle (B-1) dispersion was dropped at a rate of 0.5 ml / min while the temperature of the dispersion at 49 ° C. was raised at a rate of 1.6 ° C./h to obtain aggregated particles (2). A dispersion was obtained. Table 3 shows the volume-median particle size, circularity, and pH of the dispersion of the obtained aggregated particles (2). Moreover, the temperature of the dispersion liquid after completion | finish of dripping was 57 degreeC.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in step (3) was heated to 55 ° C. and held at 55 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.
<Washing / Drying / External Addition Process>
Next, the dispersion was cooled to 25 ° C., and the solid content was separated by suction filtration while being kept at 25 ° C., washed with deionized water, and dried at 33 ° C. to obtain toner particles. Table 3 shows the circularity, the BET specific surface area, and the volume-median particle size of the obtained toner. 100 parts by weight of the toner particles, 2.5 parts by weight of hydrophobic silica (trade name: RY50, manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.04 μm), and hydrophobic silica (trade name: Cabo Seal TS720, Cabot Corporation) Manufactured, average particle size: 0.012 μm) was added to a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain toner B. Table 3 shows the physical properties of the toner and the evaluation of the toner.

Example 3
(Preparation of toner C)
A toner was prepared in the same manner as in Example 1 except that the step (4) was held at 53 ° C. for 3 hours. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 4
(Preparation of Toner D)
A toner was prepared in the same manner as in Example 1 except that the step (4) was held at 60 ° C. for 3 hours. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 5
(Preparation of Toner E)
A toner was prepared in the same manner as in Example 1 except that the step (3) was changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 2.5.

Example 6
(Production of Toner F)
A toner was prepared in the same manner as in Example 1 except that the step (3) was changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 4.5.

Example 7
(Preparation of toner G)
A toner was prepared in the same manner as in Example 1 except that the step (3) was changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 5.5.

Example 8
(Preparation of Toner H)
Except that the amount of polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) was changed to 1.72 g. A toner was prepared in the same manner as in Example 1. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
Example 9
(Preparation of Toner I)
Except that the amount of polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) was changed to 1.15 g. A toner was prepared in the same manner as in Example 1. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 10
(Production of Toner J)
Except that the amount of polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) was changed to 5.17 g. A toner was prepared in the same manner as in Example 1. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 11
(Preparation of toner K)
Polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, product name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) is polyoxyethylene (18) distyrenated phenyl ether (nonion) A toner was prepared in the same manner as in Example 1 except that the surfactant was changed to Emulgen A-90 (trade name: manufactured by Kao Corporation). Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 12
(Preparation of Toner L)
Polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) is converted to polyoxyethylene (15) tribenzylphenyl ether (nonion) A toner was prepared in the same manner as in Example 1 except that the surfactant was changed to Emulgen B-66, manufactured by Kao Corporation. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Example 13
(Preparation of Toner M)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Step (3): Aggregated Particle (2) Addition of Surfactant to Dispersion>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) is added to polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation. ) A mixed aqueous solution of 3.45 g and 3813 g of deionized water was added.
<Step (4): Fusion Step of Aggregated Particles (2) and Addition of Acid>
The dispersion obtained by mixing the agglomerated particles (2) and the surfactant added in the step (3) is heated to 55 ° C. and held at 55 ° C. for 1 hour, and then 2.0 N sulfuric acid is added to adjust the pH. Adjusted to 3.5. Thereafter, the temperature was further maintained at 55 ° C. for 2 hours, and the particles were fused to obtain core-shell particles.

Example 14
(Preparation of toner N)
A toner was prepared in the same manner as in Example 1 except that the step (4) was changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 65 ° C. and held at 65 ° C. for 1 hour, and the particles were fused to obtain core-shell particles.

Example 15
(Production of Toner O)
A toner was prepared in the same manner as in Example 1 except that the resin particles added in the step (2) were changed to the resin particles (B-2). Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.

Comparative Example 1
(Production of Toner P)
A toner was prepared in the same manner as in Example 1 except that sulfuric acid was not added in step (3). Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. Of the toner evaluations, regarding the low-temperature fixability and dot reproducibility, the toner was crushed at the time of evaluation, and a printed matter that could be evaluated was not obtained.

Comparative Example 2
(Production of Toner Q)
Polyoxyethylene (13) distyrenated phenyl ether (nonionic surfactant, trade name: Emulgen A-60, manufactured by Kao Corporation) used in step (3) is dissolved in sodium dodecylbenzenesulfonate aqueous solution (anionic surfactant) Toner was prepared in the same manner as in Example 1 except that the product name was changed to 31.2 g (trade name: Neoperex G-15, manufactured by Kao Corporation, solid content 16%). Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. Of the toner evaluations, regarding the low-temperature fixability and dot reproducibility, the toner was crushed at the time of evaluation, and a printed matter that could be evaluated was not obtained.

Comparative Example 3
(Preparation of Toner R)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) was added to a sodium alkyldiphenyl ether disulfonate aqueous solution (anionic surfactant, trade name: Perex SS-H, manufactured by Kao Corporation, solid content 50 %) A mixed solution of 10.0 g and 3813 g of deionized water was added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 4
(Production of Toner S)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) was added to a polyoxyethylene (2) sodium lauryl ether sulfate aqueous solution (anionic surfactant, trade name: EMAL E-27C, Kao Corporation) Manufactured, 27% solid content) and 18.5 g of a mixed solution of 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 5
(Preparation of toner T)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) The dispersion (total amount) is added to polyoxyethylene (12) stearyl ether (nonionic surfactant, trade name: Emulgen 320P, manufactured by Kao Corporation, solid content 100 %) 5.17 g and an aqueous solution mixed with 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 6
(Preparation of toner U)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) The dispersion (total amount) is added to polyoxyethylene (13) oleyl ether (nonionic surfactant, trade name: Emulgen 420, manufactured by Kao Corporation, solid content 100 %) 5.17 g and an aqueous solution mixed with 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 7
(Preparation of Toner V)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) The dispersion (total amount) was added to polyoxyethylene (9) lauryl ether (nonionic surfactant, trade name: Emulgen 109P, manufactured by Kao Corporation, solid content 100 %) 5.17 g and an aqueous solution mixed with 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 8
(Preparation of toner W)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner. As for the low-temperature fixability and dot reproducibility among the toner evaluations, a large amount of white spots (streak-shaped white lines that are not printed) occur in the printed material, and a printed material that can be evaluated was not obtained.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) The dispersion (total amount) is added to polyoxyethylene (47) lauryl ether (nonionic surfactant, trade name: Emulgen 150, manufactured by Kao Corporation, solid content 100 %) 5.17 g and an aqueous solution mixed with 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

Comparative Example 9
(Production of Toner X)
A toner was prepared in the same manner as in Example 1 except that the steps (3) and (4) were changed as follows. Table 3 shows the obtained aggregated particles (2), the physical properties of the toner, and the evaluation of the toner.
<Step (3): Aggregated particles (2) Addition of surfactant to dispersion and pH adjustment>
Aggregated particles obtained in step (2) (2) Dispersion liquid (total amount) was added to a polyoxyethylene (18) sodium lauryl ether sulfate aqueous solution (anionic surfactant, trade name: Latemul E-118B, Kao Corporation) Manufactured, 26% solid content) 19.9 g and an aqueous solution mixed with 3813 g of deionized water were added. Thereafter, 2.0 N sulfuric acid was added so that the pH at 25 ° C. was 3.5.
<Process (4): Fusion process of aggregated particles (2)>
The aggregated particle (2) dispersion whose pH was adjusted in the step (3) was heated to 60 ° C. and held at 60 ° C. for 3 hours, and the particles were fused to obtain core-shell particles.

  From Table 3, it can be seen that the electrophotographic toners of the examples are all excellent in low-temperature fixability and chargeability and dot reproducibility of the obtained printed matter as compared with the electrophotographic toners of the comparative examples.

  The electrophotographic toner obtained by the production method of the present invention has both good low-temperature fixability and chargeability, and is excellent in dot reproducibility of the obtained printed matter. Therefore, the electrophotographic toner used in the electrophotographic method Can be suitably used. According to the method of the present invention, a toner having such characteristics can be produced efficiently.

Claims (12)

The pH at 25 ° C. of an aqueous mixed solution containing the aggregated particles including the resin particles (A) and the release agent particles and the nonionic surfactant represented by the following general formula (1) is 2.5 to 5. 5. A method for producing an electrophotographic toner, comprising the step of fusing the aggregated particles in the aqueous mixed solution after and / or while adjusting.

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, R ² represents a hydrogen atom or a methyl group, m represents an average value of 1 to 4, and AO represents an ethyleneoxy group. And / or a propyleneoxy group, and n has an average value of 5 to 100.) The method for producing an electrophotographic toner according to claim 1, wherein the aggregated particles are aggregated particles (2) obtained by the following steps (1) and (2).
Step (1): Step of obtaining the aggregated particles (1) by mixing the resin particles (A), the release agent particles and the flocculant in an aqueous medium and aggregating them Step (2): Obtained in Step (1) Adding the resin particles (B) containing the amorphous polyester (b) to the obtained aggregated particles (1) to obtain the aggregated particles (2)   The step of fusing the agglomerated particles maintains the agglomerated particles (2) at a temperature not lower than 15 ° C lower than the glass transition point of the amorphous polyester (b) and not higher than 10 ° C higher than the glass transition point. The method for producing an electrophotographic toner according to claim 2, which is a step (4) of obtaining fused core-shell particles.   The toner for electrophotography according to claim 3, further comprising a step (3) of adding a nonionic surfactant represented by the general formula (1) after the step (2) and before the step (4). Manufacturing method. The method for producing an electrophotographic toner according to claim 4 , wherein in step (3) and / or step (4), an acid is added to adjust the pH to 2.5 to 5.5. The average particle diameter of the fused-shell particles, the average particle diameter or less of a aggregated particles (2), a manufacturing method of toner for electrophotography according to any one of claims 3-5. Circularity of the fused core-shell particles, 0.01 or more greater than the circularity of the aggregated particles (2), a manufacturing method of toner for electrophotography according to any one of claims 3-6. Temperature at the time of retention in the step (4) comprises resin particles (B) 8 ° C. lower temperatures or higher than the glass transition point of, and is 10 ° C. higher temperature or lower than the glass transition point, claim 3-7 The method for producing an electrophotographic toner according to any one of the above. The method for producing an electrophotographic toner according to any one of claims 3 to 8 , wherein the amorphous polyester (b) has a glass transition point of 50 to 70 ° C. The method for producing an electrophotographic toner according to any one of claims 1 to 9 , wherein the resin particles (A) contain a crystalline polyester (a) having a melting point of 60C to 90C. Resin particles (A) contains an amorphous polyester (c), the production method of toner for electrophotography according to any one of claims 1-10. The electrophotographic toner obtained by the manufacturing method according to any one of claims 1 to 11.