JP2023147690A - Toner, toner cartridge, and image forming apparatus - Google Patents

Abstract

To provide a toner that has good adhesion to a print medium such as PET coating paper and is excellent in low temperature fixability and storage stability.SOLUTION: A toner has a core-shell structure. The core and the shell each contain a binder resin. The binder resin in the core includes a styrene-acrylic resin. The binder resin in the shell includes an amorphous polyester resin. When the binder resin in the shell is measured by a rheometer, the binder resin has a storage modulus at 70°C (G'(70°C)) of 500000 Pa or more and a storage modulus at 100°C (G'(100°C)) of 5000 Pa or less.SELECTED DRAWING: None

Description

The present invention relates to a toner that has excellent adhesion to print media, low-temperature fixability, and storage stability, and a toner cartridge and image forming apparatus containing this toner.

Toner for developing electrostatic images is used in image forming apparatuses such as printers, copiers, and facsimile machines to form images that visualize electrostatic images. Taking the formation of an image by electrophotography as an example, first, an electrostatic latent image is formed on a photoreceptor drum. Next, after this electrostatic latent image is developed with toner, it is transferred to a printing medium such as transfer paper, and the toner is heated and fixed to form an image.

Toners for developing electrostatic images generally have a structure in which fine solid particles such as silica are attached as external additives to the surface of toner base particles containing a binder resin, a colorant, wax, etc. Styrene acrylic resin is usually used as a binder resin for toner base particles.

Such toners are required to have excellent adhesion to printing media such as paper. In particular, in recent years, PET coated paper is often used as a printing medium in order to improve the diversity, design, luxury and durability of printed matter, and there is a need for excellent adhesion to PET coated paper. .

Furthermore, when forming an image on a print medium, the toner is heated to fix it, and the power for this heating accounts for most of the power consumption of image forming devices such as copying machines. Toners are required to have the property of fixing at lower temperatures (low-temperature fixability).

Conventionally, toners with excellent low-temperature fixability, heat-resistant storage properties, etc., have a core-shell structure for developing electrostatic images, in which a shell is provided on the surface of the core particles, and the core particles have a styrene acrylic resin and a release agent. The shell has a styrene acrylic modified polyester resin, the glass transition point of the styrene acrylic resin of the core particle is 35°C or more and 55°C or less, the weight average molecular weight is 20,000 or more and 40,000 or less, and the styrene acrylic modified polyester resin of the shell An electrostatic image developing toner has been proposed which has a glass transition point of 50° C. or more and 70° C. or less and a weight average molecular weight of 7,000 or more and 19,000 or less (Patent Document 1).

Japanese Patent Application Publication No. 2012-247659

Conventional toners using styrene acrylic resin as a binder resin have insufficient low temperature fixability. In order to improve low-temperature fixability, it is necessary to lower the viscosity of the toner, but lowering the viscosity of the toner deteriorates storage stability.
As a means to solve this problem, there is a toner with a core-shell structure as disclosed in Patent Document 1, but there is a trade-off problem between low-temperature fixability and storage stability for each viscosity. Balancing both was difficult.
The present invention solves the above-mentioned problems of the prior art, and provides a toner that has good adhesion to print media such as PET coated paper, excellent low-temperature fixability and storage stability, and a toner cartridge containing this toner. and an image forming apparatus.

The present inventor has repeatedly studied to solve the above problems, and in a toner with a core-shell structure, uses a styrene acrylic resin as a binder resin for the core and an amorphous polyester resin as a binder resin for the shell. The binder resin has a predetermined low viscosity, specifically, the storage modulus at 70°C (G'(70°C)) is a predetermined value or more, and the storage modulus at 100°C (G'(70°C)) It has been found that the above problem can be solved by using a material whose temperature (100° C.) is below a predetermined value.
That is, the gist of the present invention is as follows.

[1] A toner having a core-shell structure,
The core and the shell each contain a binder resin,
The binder resin of the core includes styrene acrylic resin,
The binder resin of the shell includes an amorphous polyester resin,
When the binder resin of the shell is measured with a rheometer, the storage modulus at 70°C (G' (70°C)) is 500000 Pa or more, and the storage modulus at 100°C (G' (100°C)) ) is 5000 Pa or less.

[2] The toner according to [1], wherein the core binder resin is a styrene acrylic resin, and the shell binder resin is an amorphous polyester resin.

[3] The toner according to [1] or [2], wherein the content of the amorphous polyester resin is 3% by mass or more and 40% by mass or less based on the total mass of the toner.

[4] The toner according to any one of [1] to [3], wherein the toner contains wax, and the content of the wax in the toner is 5% by mass or more and 30% by mass or less.

[5] A toner cartridge containing the toner according to any one of [1] to [4].

[6] An image forming apparatus containing the toner according to any one of [1] to [4].

According to the present invention, there is provided a toner that has good adhesion to print media such as PET coated paper and has excellent low-temperature fixability and storage stability, and a toner cartridge and image forming apparatus containing this toner. .

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments of the invention) will be described in detail. Note that the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

In this specification, when expressed as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it means "more than or equal to X and less than or equal to Y", and also means "preferably greater than It also includes the meaning of "less than".
In addition, when expressed as "more than or equal to X" (X is any number) or "less than or equal to Y" (Y is any number), the expression "preferably greater than X" or "preferably less than Y" should be used. It also includes intent.

[toner]
The toner according to the embodiment of the present invention (referred to as "main toner") is a toner having a core-shell structure, wherein the core and the shell each contain a binder resin, and the binder resin of the core is styrene acrylic. The binder resin of the shell includes an amorphous polyester resin, and the storage modulus at 70°C (G' (70°C)) (hereinafter referred to as , sometimes simply written as "G'(70°C)") is 500,000 Pa or more, and the storage modulus at 100°C (G' (100°C)) (hereinafter simply referred to as "G'(100°C)" )”) is 5000 Pa or less.

The present toner contains a binder resin, preferably further contains a colorant and a wax, and, if necessary, further contains toner base particles (“present toner base particles”) containing a charge control agent and other components. It is preferable that the toner is provided with an external additive.
However, the toner is not necessarily limited to the above configuration. For example, it is not necessary to include a colorant (clear toner), a charge control agent, or an external additive.

<Mechanism>
The amorphous polyester resin used for the shell of the core-shell structure has a certain degree of viscosity at low temperatures (approximately 50 to 70 degrees Celsius) in order to maintain storage stability, and has a certain degree of viscosity at low temperatures (approximately 50 to 70 degrees Celsius) in order to maintain storage stability. (approximately 120°C), the viscosity decreases and it is necessary to become soft.
In the present invention, by using an amorphous polyester resin for the shell which can maintain high viscosity even at a lower melting point than styrene acrylic resin due to intramolecular hydrogen bonding, etc., the above contradictory viscosity characteristics can be adjusted to G' (70℃ ) and G' (100℃), and G' (70℃) is 500,000 Pa or more to maintain good storage stability, and G' (100℃) is 5,000 Pa or less. , achieves excellent low-temperature fixing properties.
That is, in the present invention, by specifying G' (70°C) and G' (100°C) of the binder resin constituting the shell, especially the polyester resin preferably used as the binder resin of the shell, storage stability and Aim for both low temperature fixability.

To explain in more detail how the present invention achieves both storage stability and low-temperature fixability, in the present invention, the toner has a core-shell structure, and a low-viscosity amorphous polyester resin forms a shell on the outside of the toner particles. Since the outermost part of the particle is easily softened during fixing, fixing can be performed even at low temperatures.
On the other hand, in general, when the viscosity of the outer shell is reduced, the core and shell become compatible during the aging process, that is, the core, which generally has a lower viscosity than the shell, and the reduced viscosity shell become compatible. The viscosity of the shell, which has been reduced in viscosity, further decreases, and as a result, the viscosity of the toner particle surface decreases, resulting in a significant decrease in storage stability.
In the present invention, by adopting a structure in which the core and shell are separated, it is possible to realize low-temperature fixing properties, and even if the viscosity of the shell is reduced to the lower limit that maintains storage stability, the shell and the shell during the aging process can be Since the compatibility of the core can be suppressed, the viscosity of the shell does not further decrease due to the influence of the lower viscosity core, and it is thought that storage stability is maintained. This phenomenon occurs because the shell is discontinuously formed on the surface of the core and takes on a dispersed shape, which reduces the contact area between toner particles and makes it difficult for particles to fuse together when heat or pressure is applied. It is also conceivable that spacer effects and the like may also be contributing.
Regarding the above-mentioned structure in which the core and shell are separated, the styrene acrylic resin of the core and the amorphous polyester resin of the shell of the core-shell structure of the present toner are modified such as styrene acrylic modified polyester resin as in Patent Document 1 mentioned above. The fact that it is not a polyester resin is an important constituent requirement. That is, in Patent Document 1, the shell and core are composited by styrene-acrylic modification of polyester resin as a connecting part between the core and shell, but in the present invention, for example, such a connecting part is not provided, and the core is By having a structure in which the core and the shell are separated, the core is less affected by the shell, and stable storage stability can be obtained.

As described above, in the present invention, it is preferable to have a structure in which the core and shell are separated, but in order to obtain such a structure, the toner composition can be, for example, as follows.
1) The content of styrene acrylic segment in the amorphous polyester resin of the shell is below a certain value.
2) The content of polyester segments in the styrene acrylic resin of the core is below a certain value.
3) The ratio of the acid value of the core styrene acrylic resin and the shell amorphous polyester resin ([the acid value of the core styrene acrylic resin]/[the acid value of the shell amorphous polyester resin]) is 0.85. The above value is 2.9 or less.
In the case of 1) above, the content of the styrene acrylic segment in the amorphous polyester resin of the shell is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the amorphous polyester resin. Parts by mass or less are more preferable. That is, it is more preferable that the amorphous polyester resin of the shell does not contain a styrene acrylic segment, in other words, it is not a styrene acrylic modified polyester resin.
In the case of 2) above, the content of the polyester segment in the styrene acrylic resin of the core is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 5 parts by mass or less, based on 100 parts by mass of the styrene acrylic resin. preferable. That is, it is preferable that the core styrene acrylic resin does not contain a polyester segment. Note that the method for polymerizing the polyester segment into the styrene acrylic resin includes, for example, the following method, but any method may be used.
2-1) A method of reacting a bireactive monomer with a polyester polymerization segment and reacting with a styrene-acrylic raw material monomer.
2-2) A method in which a styrene acrylic resin is reacted with a bireactive monomer to react with a polyhydric carboxylic acid monomer and a polyhydric alcohol monomer.
2-3) A method of reacting styrene acrylic resin and polyester resin with bireactive monomers to chemically bond them.
In the case of 3) above, the ratio of the acid values of the styrene acrylic resin of the core and the amorphous polyester resin of the shell ([the acid value of the styrene acrylic resin of the core]/[the acid value of the amorphous polyester resin of the shell]) The lower limit is more preferably 0.90 or more, further preferably 1.0 or more, and the upper limit is more preferably 2.5 or less, even more preferably 2.0 or less. If the above lower limit is exceeded, the hydrophilicity of the shell becomes higher than that of the core, making it difficult for the toner particles to enter the inside of the toner particles during the aging process.If the above upper limit is exceeded, the hydrophilicity of the shell is not too high and the amorphous polyester resin The dispersion is moderately stabilized and an appropriate core-shell separation structure is obtained.

<Material toner particles>
In order to more effectively obtain the above effects, this toner has a core containing styrene acrylic resin as a binder resin, and a binder resin that satisfies specific G' (70°C) and G' (100°C). In the core-shell structure with a shell containing an amorphous polyester resin, the binder resin of the core is preferably a styrene acrylic resin, and the binder resin of the shell is preferably made of the above-mentioned amorphous polyester resin.

In the present invention, the term "core-shell structure" refers to a structure in which the surface of a core component is covered with a shell component, but is not limited to a structure in which a core component is completely covered with a shell component; A portion of the surface of the component may be exposed, or a portion may be dispersed in the shell component.

In any method for preparing toner base particles as described below, the shell component refers to a component that is unevenly distributed on the surface of the toner base particles. The shape of the shell component when it becomes a toner may be in the form of fine particles or a thin film, and furthermore, it may cover the core component continuously or discontinuously.

When producing toner base particles in a wet medium containing an aqueous and/or organic solvent as a continuous phase, shell fine particles are added at the same time as the core component, and the shell fine particles are thermodynamically bonded to the interface between the core component and the wet medium. There is a method of arranging shell particles (method of controlling polarity) and a method of adding shell particles after the core component and physically arranging them on the surface of the core component. Furthermore, there is a method of thermodynamically arranging shell particles at the interface between the core component and the wet medium (method of controlling polarity), and a method of adding shell particles after the core component and physically arranging them on the surface of the core component. Combinations of methods can also be used.

In addition, when adding shell particles after the core component, the composition and/or shape of the core component must be determined (after that, the shape, physical properties, compatibility, etc. of the core component may change due to heating, aging, stirring, etc.). ), and a method of adding additionally is also mentioned.

The present toner base particles preferably contain a binder resin such as styrene acrylic resin, and if necessary, a colorant and wax, and further preferably contain a charge control agent and other components. Although it is preferable that the shell uses the binder resin alone, it may contain a colorant or wax as necessary, and may further contain a charge control agent and other components.

<Styrene acrylic resin>
Styrene acrylic resin (hereinafter sometimes abbreviated as "StAc") is a copolymer formed using a styrene monomer and a (meth)acrylate monomer. Further, the copolymer is preferably a copolymer formed using a (meth)acrylic acid monomer in addition to a styrene monomer and a (meth)acrylic acid ester monomer.

Examples of styrenic monomers include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, p-ethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn -dodecylstyrene, 2,4-dimethylstyrene, dichlorostyrene, etc. These can be used alone or in combination of two or more.
Among these, from the viewpoints of reactivity, ease of polymerization, and cost, styrene and p-methylstyrene are preferred, and styrene is more preferred.

Examples of (meth)acrylic acid ester monomers include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, and hexyl acrylate. , cyclohexyl acrylate, heptyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, methacrylate Examples include 2-ethylhexyl acid, heptyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate. These can be used alone or in combination of two or more.
Among these, propyl acrylate, n-butyl acrylate, isobutyl acrylate, and 2-ethylhexyl acrylate are preferred from the viewpoint of toner fixability, non-offset property, and cost; 2-ethylhexyl is more preferred, and n-butyl acrylate is even more preferred.

Examples of the (meth)acrylic acid monomer include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and cinnamic acid. These can be used alone or in combination of two or more.
Among these, from the viewpoint of reactivity and ease of polymerization, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred.

The proportion of the styrene monomer in 100% by mass of all the monomers constituting the styrene acrylic resin is preferably 50% by mass or more, more preferably 60% by mass or more, and 65% by mass or more from the viewpoint of storage stability of the toner. More preferred. On the other hand, from the viewpoint of toner fixability, the content is preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less.
The proportion of the (meth)acrylic acid ester monomer in 100% by mass of all the monomers constituting the styrene acrylic resin is preferably 10% by mass or more, more preferably 15% by mass or more, and 20% by mass or more from the viewpoint of toner fixability. More preferably, the amount is % by mass or more. On the other hand, from the viewpoint of storage stability of the toner, the content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.
The proportion of the (meth)acrylic acid monomer in 100% by mass of all the monomers constituting the styrene acrylic resin is preferably 0.3% by mass or more, more preferably 0.5% by mass or more from the viewpoint of toner developability. It is preferably 0.7% by mass or more, and more preferably 0.7% by mass or more. On the other hand, from the viewpoint of the environmental stability of the toner, the content is preferably 3.0% by mass or less, more preferably 2.5% by mass or less, and even more preferably 2.0% by mass or less.

The content ratio of the styrene monomer and (meth)acrylic ester monomer constituting the styrene acrylic resin is preferably 0.18 or more, and 0.25 or more of the (meth)acrylic ester monomer to the styrene monomer. More preferably, on the other hand, it is preferably 0.67 or less, and more preferably 0.54 or less. In particular, by setting the amount in the range of 0.49 or more and 0.54 or less, excellent low-temperature fixability can be achieved while maintaining storage stability at a practically usable level.
The content ratio of the styrene monomer and (meth)acrylic acid monomer constituting the styrene acrylic resin is preferably 0.005 or more, more preferably 0.006 or more of the (meth)acrylic acid monomer to the styrene monomer. , on the other hand, is preferably 0.035 or less, more preferably 0.03 or less.

Furthermore, the styrene acrylic resin can be made into a crosslinked structure by using other monomers. Other monomers include hexanediol diacrylate, divinylbenzene, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, Examples include neopentyl glycol diacrylate. Among these, hexanediol diacrylate is preferred.

The styrene acrylic resin preferably has a mass average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) of 30,000 to 150,000.
When the mass average molecular weight (Mw) of the styrene acrylic resin is 30,000 or more, sufficient heat-resistant storage properties can be obtained. Furthermore, when the weight average molecular weight (Mw) of the styrene acrylic resin is 150,000 or less, sufficient low-temperature fixability can be obtained.
The method for measuring the mass average molecular weight (Mw) of the styrene acrylic resin is as described in the Examples section below.

Only one type of styrene acrylic resin may be used, or two or more types of styrene acrylic resins having different monomer compositions, physical properties, etc. may be used in combination.

The content of styrene acrylic resin in this toner is 60 to 85% by mass based on the total mass (100% by mass) of this toner from the viewpoint of cost reduction, environmental stability, fixing performance, and storage stability of the toner. The amount is preferably 65 to 80% by mass. If the content of styrene acrylic resin is above the above lower limit, there will be great cost benefits, and environmental stability and storage stability under high humidity conditions will be maintained. Since the content is sufficient, it is preferable from the viewpoint of improving adhesion to the medium and maintaining storage stability of the toner.

<Amorphous polyester resin>
The binder resin of the core of this toner satisfies specific G' (70°C) and G' (100°C), and is made of amorphous polyester resin (sometimes abbreviated as "amorphous PES"). It preferably consists of the amorphous polyester resin.

Amorphous polyester resin is a polyester that exhibits amorphous properties that have a glass transition point (Tg) in an endothermic curve obtained by differential scanning calorimetry (DSC), but do not have a clear endothermic peak when the temperature is increased. Refers to resin.

The amorphous polyester resin is obtained by polycondensation reaction using polycarboxylic acid monomers (derivatives) and polyhydric alcohol monomers (derivatives) as raw materials in the presence of an appropriate polymerization catalyst. As polyhydric carboxylic acid monomer derivatives, for example, alkyl esters, acid anhydrides, and acid chlorides of polyhydric carboxylic acid monomers can be used, and as polyhydric alcohol monomer derivatives, for example, esters and polyhydric alcohol monomers can be used. Hydroxycarboxylic acids can be used.

Examples of polycarboxylic acid monomers include oxalic acid, succinic acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, Fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, malic acid, citric acid, hexahydroterephthalic acid, malonic acid, pimelic acid, tartaric acid, mucilage acid, phthalic acid, Isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylene diacetic acid, m-phenylene diglycolic acid, p-phenylene diglycolic acid, o-phenylene diglycolic acid, Divalent acids such as diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, dodecenylsuccinic acid, etc. carboxylic acids; examples include trivalent carboxylic acids such as trimellitic acid, pyromellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, and pyrenetetracarboxylic acid. These can be used alone or in combination of two or more.
Among these, as divalent carboxylic acids, maleic acid, adipic acid, fumaric acid, cyclohexane-3,5-diene-1,2- Dicarboxylic acid, isophthalic acid, and terephthalic acid are preferred, adipic acid, isophthalic acid, and terephthalic acid are more preferred, and isophthalic acid and terephthalic acid are even more preferred.
As the trivalent carboxylic acid, from the viewpoint of ease of adjusting the polymerization rate, trimellitic acid and pyromellitic acid are preferred, and trimellitic acid is more preferred.

Examples of polyhydric alcohol monomers include ethylene glycol, neopentyl glycol, propylene glycol, butanediol, diethylene glycol, hexanediol, cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4- Dihydric alcohols such as cyclohexanedimethanol, octanediol, decanediol, dodecanediol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A; glycerin, pentaerythritol, trimethylolpropane, hexamethylolmelamine, hexaethyl Examples include trivalent or higher polyols such as roll melamine, tetramethylol benzoguanamine, and tetraethylol benzoguanamine. These can be used alone or in combination of two or more.
Among these, dihydric alcohols include ethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, and bisphenol A, from the viewpoint of reducing resin coloring, ease of obtaining raw materials, and charging characteristics. Ethylene oxide adducts and propylene oxide adducts of bisphenol A are preferred, ethylene glycol and ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A are more preferred, and ethylene glycol and propylene oxide adducts of bisphenol A are even more preferred. .
As the trivalent or higher polyol, from the viewpoint of ease of adjusting the polymerization rate, glycerin, pentaerythritol, and trimethylolpropane are preferred, and trimethylolpropane is more preferred.

The ratio of polyhydric carboxylic acid and polyhydric alcohol is such that the equivalent ratio (OH)/(COOH) of the hydroxyl group (OH) of the polyhydric alcohol and the carboxy group (COOH) of the polyhydric carboxylic acid is 1.5/1. It is preferably within the range of ~1/1.5.

An essential component of the binder resin of the shell according to the present invention is that G' (70° C.) is 500,000 Pa or more. When the binder resin of the shell has a G' (70° C.) of 500,000 Pa or more, excellent storage stability can be obtained. From the viewpoint of storage stability, the G' (70° C.) of the binder resin of the shell is preferably 700,000 Pa or more, more preferably 1,000,000 a or more. On the other hand, the G' (70° C.) of the binder resin of the shell is preferably 5,000,000 Pa or less, particularly 3,000,000 Pa or less from the viewpoint of low-temperature fixability.

Furthermore, an essential component of the binder resin of the shell used in the present invention is that G' (at 100° C.) is 5000 Pa or less. When the G' (70° C.) of the binder resin of the shell is 5000 Pa or less, excellent low-temperature fixability can be obtained. From the viewpoint of low-temperature fixability, the G' (100° C.) of the binder resin of the shell is preferably 3000 Pa or less, more preferably 2000 Pa or less. On the other hand, from the viewpoint of storage stability, G' (100° C.) of the binder resin of the shell is preferably 500 Pa or more, particularly 1000 Pa or more.
As mentioned above, in the present invention, the binder resin of the shell is preferably made of amorphous polyester resin, and therefore the amorphous polyester resin constituting the shell has the above-mentioned G' (70°C) and G' (100°C). It is preferable to meet the requirements.
Note that G' (70° C.) and G' (100° C.) of the binder resin are measured by the method described in the Examples section below.

In the present invention, in order to obtain a binder resin having contradictory physical properties as G' (70°C) and G' (100°C), the above G' (70°C) must be used alone as the binder resin of the shell. ) and G' (100°C), in addition to using an amorphous polyester resin that satisfies only the above G' (70°C) and an amorphous polyester that satisfies only the above G' (100°C). An example of this method is to mix the amorphous polyester resin with a resin so that G' (70° C.) and G' (100° C.) of the amorphous polyester resin as a mixture satisfy the above conditions.

The acid value of the amorphous polyester resin is preferably 6 mgKOH/g or more.
When the acid value of the amorphous polyester resin is equal to or higher than the above lower limit, sufficient stability can be obtained for use as a polyester dispersion in the aggregation step for producing toner base particles. On the other hand, the acid value of the amorphous polyester resin is preferably 20 mgKOH/g or less from the viewpoint of ease of producing particles having polyester on the surface.
The acid value of the amorphous polyester resin is more preferably 8 mgKOH/g or more, still more preferably 10 mgKOH/g or more, while more preferably 18 mgKOH/g or less, still more preferably 15 mgKOH/g or less.
Note that the acid value of the amorphous polyester resin is measured by the method described in the Examples section below.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably within the range of 50 to 65°C. If the glass transition temperature of the amorphous polyester resin is equal to or higher than the above lower limit, the storage stability of the toner is maintained. If the glass transition temperature of the amorphous polyester resin is below the above upper limit, the low-temperature fixing properties of the toner will not be deteriorated, and the surface of the particles will be easily covered evenly in the aging process during the preparation of toner base particles. The glass transition temperature of the amorphous polyester resin is more preferably 53°C or higher, even more preferably 55°C or higher, and more preferably 63°C or lower, even more preferably 60°C or lower.
Note that the glass transition temperature of the amorphous polyester resin is measured by the method described in the Examples section below.

Further, the softening temperature of the amorphous polyester resin is preferably within the range of 90 to 150°C. When the softening temperature of the amorphous polyester resin is equal to or higher than the above lower limit, the storage stability of the toner is maintained. If the softening temperature of the amorphous polyester resin is below the above upper limit, the low-temperature fixability of the toner will not deteriorate. The softening temperature of the amorphous polyester resin is more preferably 95°C or higher, even more preferably 100°C or higher, and more preferably 135°C or lower, even more preferably 125°C or lower.
Note that the softening temperature of the amorphous polyester resin is measured by the method described in the Examples section below.

The present toner may contain only one type of amorphous polyester resin as the shell binder resin, or may contain two or more types of amorphous polyester resins having different monomer compositions, physical properties, etc.

The amorphous polyester resin is preferably contained in a proportion of 3% by mass or more and 40% by mass or less based on the total mass of the toner. If the content of the amorphous polyester resin in the toner is 3% by mass or more, a toner with excellent storage stability can be obtained. From this point of view, the content of the amorphous polyester resin in the present toner is preferably 5% by mass or more, particularly preferably 8% by mass or more. On the other hand, if the content of the amorphous polyester resin in the toner is 40% by mass or less, a toner with excellent low-temperature fixability can be obtained. From this point of view, the content of the amorphous polyester resin in the present toner is preferably 30% by mass or less, particularly preferably 20% by mass or less.

<Colorant>
As the colorant contained in the present toner, any known colorant can be used. Specific examples of colorants include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes and pigments, chrome yellow, quinacridone dyes, benzidine yellow, rose bengal, triallylmethane dyes, and monoazo dyes. Any known dyes and pigments such as , disazo dyes and condensed azo dyes and pigments can be used alone or in combination.
In the case of full-color toner, yellow is a monoazo-based, disazo-based, polyazo-based, or condensed azo-based dye and pigment; magenta is a quinacridone-based and/or monoazo-based dye and pigment; cyan is a phthalocyanine-based dye and pigment; black It is preferable to use carbon black or the like. As a combination of toner sets, the magenta toner contains a quinacridone-based dye and pigment and/or a monoazo-based dye and pigment, the black toner contains carbon black, and the cyan toner contains a copper phthalocyanine-based dye and pigment; The yellow toner preferably contains at least one dye and pigment selected from monoazo, disazo, and condensed azo dyes.
Specifically, as cyan, C. I. Pigment Blue 15:3, C. I. pigment blue 15:4, yellow as C. I. Pigment Yellow 74, C.I. Pigment Yellow 74, a disazo dye and pigment. I. Pigment Yellow 83, a condensed azo dye and pigment C.I. I. Pigment Yellow 93, C. I. Pigment Yellow 155, C. I. Pigment Yellow 180, C. I. pigment yellow 185, magenta as C. I. Pigment Red 48:1, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 5, C.I., a quinacridone dye and pigment. I. Pigment Red 122, C. I. Pigment Red 209, C.I. Pigment Red 209, a monoazo dye and pigment. I. Pigment Red 269 (238) and the like.

The colorant is preferably used in an amount of 3 to 20% by weight based on the total weight (100% by weight) of the toner.

<Wax>
The present toner may further contain wax, and by containing wax, low-temperature fixing properties and high-temperature offset properties can be improved. The wax may be contained in any form in the toner. For example, a part or all of the wax may be present in a compatible manner with the binder resin, or the wax may be contained separately in the core as a domain. The toner may be separated from the shell as a domain and encapsulated therein, or may be present separately on the surface of the toner.

That is, by containing wax, particularly crystalline wax, when heat is applied to the toner, the wax melts instantly, thereby improving the fixability to the printing medium. In addition, when the wax is encapsulated in the core as a domain and separated from the core, the toner is not plasticized, so that retention stability can also be maintained. Specifically, when the wax is a crystalline wax that has a clearer melting point than normal wax, its compatibility with the binder resin decreases, resulting in a structure in which the wax and the core binder resin are separated. Therefore, the resin is difficult to plasticize and storage stability can be maintained.

The type of wax contained in the present toner is not limited. Among these, it is preferable to contain an ester wax, and more preferably a crystalline wax described below.

Examples of ester waxes include ester waxes having long chain aliphatic groups such as behenyl behenate, montanate ester, stearyl stearate, and erythritol tetrabehenate.
Among these, monoester waxes containing mainly C18 and/or C22 hydrocarbons are more preferable, and from the viewpoint of low dust and low temperature fixing, monoester waxes containing mainly behenyl behenate, stearyl behenate, and behenyl stearate are particularly preferred. Particularly preferred are those containing
Further, the number of carbon atoms in one molecule of the ester wax is preferably 36 or more, more preferably 40 or more, from the viewpoint of low dust. On the other hand, from the viewpoint of low-temperature fixing, it is preferably 95 or less, more preferably 60 or less, even more preferably 48 or less, and particularly preferably 44 or less.

The crystalline wax suitably used in the present toner preferably has a melting point peak (the top of the endothermic peak during the second DSC temperature rise of the toner) of 90°C or lower, more preferably 85°C or lower, and 80°C or lower. The temperature is more preferably 50°C or higher, more preferably 60°C or higher, and even more preferably 65°C or higher. If the melting point peak temperature of the wax is too low, blocking resistance tends to deteriorate, and if the wax melting point peak temperature is too high, low temperature fixing properties and high gloss properties tend to be impaired. Furthermore, the difference between the melting point peak of the wax and the onset temperature of the wax (the intersection temperature of the baseline before the endothermic peak in the second DSC of the toner and the tangent at the first inflection point that appears before the endothermic peak) is 15°C or less. The temperature is preferably 10°C or lower, and more preferably 10°C or lower.

(Other waxes)
The present toner may contain other waxes in addition to the above-mentioned ester-based wax, or may use other waxes in combination with the above-mentioned ester-based wax.
For example, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; vegetable waxes such as hydrogenated castor oil and carnauba wax; ketones with long chain alkyl groups such as distearyl ketone; Higher fatty acids such as stearic acid; Higher fatty acid amides such as oleic acid amide and stearic acid amide; and the like. Preferred examples include hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax; silicone waxes; and the like.

(Amount of wax)
The amount of wax contained in the toner is preferably 5 to 30% by weight, more preferably 10 to 20% by weight based on the total weight (100% by weight) of the toner.
Further, of the total wax content (100% by mass), the content of the low temperature fixing wax is preferably 30% by mass or more, more preferably 40% by mass or more and 80% by mass or less. It is preferable.

<Charge control agent>
The present toner may contain a charge control agent in order to improve the charging characteristics of the toner.
Any known charge control agent can be used as the charge control agent. Specific examples of charge control agents include nigrosine dyes, amino group-containing vinyl copolymers, quaternary ammonium salt compounds, and polyamine resins for positively chargeable properties, and chromium, zinc, iron, and cobalt for negatively chargeable properties. , metal-containing azo dyes containing metals such as aluminum, salts of salicylic acid or alkylsalicylic acid with the above-mentioned metals, metal complexes, and the like.

The amount of the charge control agent is preferably 0.1 to 25% by weight, more preferably 1 to 15% by weight based on the total weight (100% by weight) of the toner.
Note that the charge control agent may be mixed inside the toner base particles, or may be used in the form of being attached to the surface of the toner base particles.

<External additives>
The present toner usually includes external additives to improve the fluidity and charge controllability of the toner. The external additive is usually attached to the surface of the toner base particles, but the extent to which the external additive is embedded in the base particles may be in any state. In other words, part or all of the external additive may be attached to the surface of the base particle so that it is in contact with the surface of the base particle, or may be embedded and attached, or some or all of the external additive may be dispersed on the surface of the base particle. It may exist as a solid state or as an agglomerated state.
The particle size of the external additive particles is such that (particle size of external additive particles)/(average particle size of toner base particles) is in the range of 0.1% to 5% of the average particle size of toner base particles. Something is desirable.

The external additive can be appropriately selected from various inorganic or organic fine particles. Furthermore, two or more types of external additives may be used in combination.

Inorganic fine particles include various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, boron nitride, and titanium nitride. , various nitrides such as zirconium nitride, various borides such as zirconium boride, various oxides such as titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, cerium oxide, silica, colloidal silica, titanium Various titanic acid compounds such as calcium acid, magnesium titanate, and strontium titanate, phosphoric acid compounds such as calcium phosphate, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and carbon fluoride, aluminum stearate, and calcium stearate. , various metal soaps such as zinc stearate and magnesium stearate, talc, bentonite, various carbon blacks, conductive carbon black, magnetite, ferrite, etc. can be used.

As the organic fine particles, fine particles of styrene resin, acrylic resin, epoxy resin, melamine resin, etc. can be used. Furthermore, charging stability can be improved by using fine particles containing fluorine atoms. Among these external additives, silica, titanium oxide, alumina, zinc oxide, various carbon blacks, conductive carbon black, and the like are particularly preferably used. In addition, external additives include silane coupling agents such as hexamethyldisilazane (HMDS) and dimethyldichlorosilane (DMDS), titanate coupling agents, silicone oil, and dimethylsilicone oil. , modified silicone oil, amino-modified silicone oil, and other silicone oil processing agents, silicone varnish, fluorine-based silane coupling agents, fluorine-based silicone oil, and coupling agents with amino groups and quaternary ammonium bases. It is also possible to use a material that has been subjected to surface treatment such as oxidation. Two or more types of these processing agents can also be used in combination.

The amount of the external additive added is preferably 1.0 parts by mass or more, particularly preferably 1.5 parts by mass or more, and preferably 6.5 parts by mass or less, 5.5 parts by mass or more, based on 100 parts by mass of the toner base particles. Parts by mass or less are particularly preferred.

In this toner, conductive fine particles may be used as an external additive from the viewpoint of charge control. Examples of conductive fine particles include conductive metal oxides such as conductive titanium oxide, silica, and magnetite, or those doped with conductive substances, and conjugated double bonds such as polyacetylene, polyphenylacetylene, and poly-p-phenylene. Examples include organic fine particles obtained by doping a conductive substance such as a metal into a polymer having a It is more preferable to use titanium oxide or titanium oxide doped with a conductive substance.

The lower limit of the content of the conductive fine particles is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and 0.2 parts by mass or more based on 100 parts by mass of the present toner base particles. It is particularly preferable that On the other hand, the upper limit of the content of the conductive fine particles is preferably 3 parts by mass or less, more preferably 2 parts by mass or less, particularly preferably 1 part by mass or less.

<Form of this toner>
From the viewpoint of image reproducibility and toner consumption, the volume median particle size of the present toner is preferably 6.5 μm or less, particularly 6.3 μm or less, and even more preferably 6.0 μm or less.
On the other hand, from the viewpoint of environmental safety against dust, the volume median particle diameter of the present toner is preferably 3.0 μm or more, particularly 4.0 μm or more, and even more preferably 4.5 μm or more.
The "volume median particle diameter (Dv50)" in the present invention is defined as the one measured by the method described in the Examples section below, and is It is defined as measured on the toner particles finally obtained in the manufacturing process, with appropriate external additives.

Furthermore, in order to suppress fogging, white background stains, etc. and to stably obtain high-quality images, it is preferable that the number percent of particles with a primary particle diameter of 1.0 μm or less is 3.0% or less. Among them, it is preferably 2.0% or less, and particularly preferably 1.0% or less.

The shape of the present toner preferably has an average circularity of 0.92 or more and 0.99 or less as measured using a flow type particle image analyzer FPIA-3000 (manufactured by Malvern), particularly 0.95 or more, Among these, it is preferably 0.96 or more.

The number percentage occupied by particles having a particle diameter of 1.0 μm or less and the average circularity are measured by the method described in the Examples section below.

[Toner manufacturing method]
The present toner can be manufactured by producing the present toner base particles by a known method and externally adding an external additive to the present toner base particles as required.

<Method for manufacturing the present toner base particles>
A method can be used in which each raw material is prepared as particles smaller than the toner base particles, and the toner base particles are obtained by mixing, agglomerating, and aging the raw materials. For example, fine particles of binder resin (primary polymer particles), colorant particles, and if necessary wax or charge control agent are mixed, aggregated and aged (heat fused), filtered, washed, and dried. In this way, toner base particles can be obtained.
The fine particles of the binder resin (primary polymer particles) are obtained by obtaining the binder resin by emulsion polymerization or by any polymerization method (bulk polymerization, solution polymerization, suspension polymerization, etc.) and then mixing it with an aqueous medium. It can be obtained by emulsifying. Polymer primary particles of styrene-acrylic resin are obtained by emulsion polymerization, which yields a water-based emulsion, from the viewpoint that it is easier to control the circularity of the final mother particles by aggregating particles using an emulsion aggregation method performed in an aqueous system. is preferable, and for the same reason, it is preferable to obtain the polymer primary particles of the polyester resin as an aqueous emulsion by the latter emulsification method.
Furthermore, any of the methods for obtaining the polymer primary particles described above can be used both when producing the polymer primary particles of the core binder resin and when producing the polymer primary particles of the shell binder resin. be able to.

(Production method of polymer primary particles: emulsion polymerization)
For example, primary polymer particles containing the raw material monomer of the styrene acrylic resin described above can be obtained by emulsion polymerization with the monomer using an emulsifier, a polymerization initiator, and a chain transfer agent as necessary.
Known emulsifiers can be used, and one or more emulsifiers selected from cationic surfactants, anionic surfactants, and nonionic surfactants can be used in combination. Among these, anionic surfactants are preferred from the viewpoints of ease of particle preparation, cleansing properties, and waste liquid treatment.

Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and the like.

Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and sodium lauryl sulfate.

Examples of nonionic surfactants include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc. can be mentioned.

The amount of emulsifier used is preferably 0.1 parts by mass or more and 10 parts by mass or less based on 100 parts by mass of the raw material monomer. When the amount of emulsifier used is increased, the particle size of the obtained primary polymer particles becomes smaller, and when the amount used is reduced, the particle size of the obtained primary polymer particles becomes larger. Moreover, one or more types of polyvinyl alcohols such as partially or fully saponified polyvinyl alcohol, cellulose derivatives such as hydroxyethyl cellulose, etc. can be used in combination with these emulsifiers as protective colloids.

As the polymerization initiator, one kind or a combination of two or more kinds of known ones can be used. For example, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, etc., redox initiators containing these persulfates as one component in combination with reducing agents such as acidic sodium sulfite, hydrogen peroxide, 4,4 Water-soluble polymerization initiators such as '-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, etc., and redox in which these water-soluble polymerization initiators are combined as one component with a reducing agent such as ferrous salt. Initiators such as benzoyl peroxide and 2,2'-azobis-isobutyronitrile are used. Among these, hydrogen peroxide is preferred from the viewpoint of reactivity and cost. These polymerization initiators may be added to the polymerization system before, simultaneously with, or after the addition of the monomers, and these addition methods may be combined as necessary.

As the chain transfer agent, one kind or a combination of two or more kinds of known ones can be used. For example, trichlorobromomethane, carbon tetrachloride, t-dodecylmercaptan, 2-mercaptoethanol, etc. are used. Among these, trichlorobromomethane is preferred from the viewpoints of low molecular weight, sharp molecular weight distribution, and cost.

Among emulsion polymerizations, it is preferable to use so-called seed polymerization, in which wax is added as a seed during emulsion polymerization. By using seed polymerization, the wax is finely and uniformly dispersed in the toner, so that deterioration of the toner's chargeability and heat resistance can be suppressed. It is also possible to prepare a wax/long chain monomer dispersion by previously dispersing wax with a long chain monomer such as stearyl acrylate in an aqueous dispersion medium, and then polymerize the monomer in the presence of the wax/long chain monomer.

(Production method of polymer primary particles: A method of obtaining a binder resin by any polymerization method and then mixing it with an aqueous medium to emulsify it)
After obtaining a binder resin by any polymerization method such as bulk polymerization, solution polymerization, or suspension polymerization, the binder resin is mixed with an aqueous medium and emulsified by applying shearing force, thereby increasing the polymerization of the binder resin. Coalesced primary particles can be obtained.

Examples of emulsifiers for applying shearing force include homogenizers, homomixers, pressure kneaders, extruders, media dispersers, and the like.
If the viscosity of the binder resin during emulsification is high and the primary polymer particles cannot be reduced to the desired particle size, use an emulsifier that can pressurize above atmospheric pressure to increase the temperature at either the melting point or glass transition temperature of the resin. By raising the temperature above a high temperature and emulsifying the resin while lowering the viscosity, primary polymer particles having a desired particle size can be obtained.

Another method for lowering the resin viscosity is to mix an organic solvent into the binder resin in advance. The organic solvent used is not particularly limited as long as it dissolves the styrene acrylic resin, but includes ketone solvents such as tetrahydrofuran (THF), methyl acetate, ethyl acetate, and methyl ethyl ketone, and benzene such as benzene, toluene, and xylene. A system solvent or the like can be used. Furthermore, an alcoholic solvent such as ethanol or isopropyl alcohol may be added to water or the resin for the purpose of improving affinity with aqueous media and controlling particle size distribution. When an organic solvent is added, it is necessary to remove the organic solvent from the emulsion after emulsification is completed. As a method for removing the organic solvent, there is a method of volatilizing the organic solvent while reducing pressure at room temperature or under heating.

Further, for the purpose of particle size distribution control, salts such as sodium chloride and potassium chloride, ammonia, etc. may be added, and emulsifiers and dispersants may be added.
Examples of emulsifiers and dispersants at this time include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, carboxymethyl cellulose, and sodium polyacrylate; the above emulsifiers; tricalcium phosphate, aluminum hydroxide, calcium sulfate, and calcium carbonate. and inorganic compounds such as barium carbonate. The amount used is preferably 0.01 to 20 parts by weight per 100 parts by weight of the binder resin.

Further, as a method for obtaining a binder resin by any polymerization method and then mixing it with an aqueous medium to emulsify it, a phase inversion emulsification method may be used in addition to the above-mentioned method. In the phase inversion emulsification method, organic solvents, neutralizers, and dispersion stabilizers are added to the binder resin as necessary, and an aqueous medium is added dropwise to the binder resin under stirring to obtain emulsified particles. This method removes the organic solvent inside to obtain an emulsion. As the organic solvent, the same organic solvents as those described above can be used. As the neutralizing agent, general acids and alkalis such as nitric acid, hydrochloric acid, sodium hydroxide, and ammonia can be used.

(Particle size and molecular weight of polymer primary particles)
The median diameter (D50) of the primary polymer particles of the binder resin is preferably 100 nm or more, more preferably 150 nm or more, and even more preferably 180 nm or more. On the other hand, the thickness is preferably 350 nm or less, more preferably 300 nm or less, and even more preferably 280 nm or less.
Moreover, the mass average molecular weight (Mw) of the polymer primary particles of the binder resin is preferably 30,000 or more, more preferably 40,000 or more, and even more preferably 50,000 or more. On the other hand, it is preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 150,000 or less.
The median diameter (D50) and mass average molecular weight (Mw) of the primary polymer particles of the binder resin are measured by the method described in the Examples section below.

(Agglomeration process)
In the aggregation step, the polymer primary particles, if necessary, colorant particles, charge control agent, wax, etc. are mixed simultaneously or sequentially. A dispersion of each component, that is, a primary polymer particle dispersion, a colorant particle dispersion as necessary, a charge control agent dispersion, and a wax fine particle dispersion, are prepared in advance, and these are mixed to form a mixed dispersion. It is preferable to obtain the following from the viewpoint of uniformity of composition and uniformity of particle size.

When the toner base particles have a core-shell structure, the primary polymer particles of the core binder resin and the polymer primary particles of the shell binder resin may be charged at the same time, or the primary polymer particles of the core binder resin may be charged at the same time. After some or all of the components have been agglomerated with other components, the primary polymer particles of the shell binder resin may be added.

When the primary polymer particles of the core binder resin (also referred to as the core component) and the polymer primary particles of the shell binder resin (also referred to as the shell component) are charged at the same time, the core component and the medium (for example, If the polarity of the shell component is designed to have a polarity between that of water), the shell component will spontaneously adhere around the core component. When depositing the shell component in a wet medium such as water and/or an organic solvent, the composition of the raw material for the core component is determined (in the case where toner base particles are produced by agglomerating particles smaller than the toner base particles). It is preferable to add the shell component after agglomerating some or all of the core component, from the viewpoint of disposing the shell component more on the surface of the core component.

The shell component may be added once or multiple times. The first shell component and the subsequent shell components may be different and may be in any combination. Further, in order to increase the stability of the core-shell structure particle aggregate obtained in the aggregation step, it is preferable to perform fusion within the aggregated particles in the aging step after the aggregation step.

The colorant particles are preferably used in a dispersed state in water in the presence of an emulsifier, and the volume average particle diameter of the colorant particles is preferably 0.01 μm or more, particularly preferably 0.05 μm or more, Preferably it is 3 μm or less, particularly preferably 1 μm or less.

In the aggregation step, aggregation is usually carried out in a tank equipped with a stirring device, and there are methods of aggregation by heating, a method of aggregation by adding an electrolyte, and a method of combining these methods.

When performing flocculation by adding an electrolyte, the electrolyte may be acid, alkali, or salt, and may be organic or inorganic. Acids, etc.; as alkalis, sodium hydroxide, potassium hydroxide, aqueous ammonia, etc.; as salts, NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na, and the like. Among these, inorganic salts having a polyvalent metal cation of divalent or higher valence are preferred.

The amount of electrolyte added varies depending on the type of electrolyte, the intended particle size, etc., but is preferably 0.02 parts by mass or more, and more preferably 0.05 parts by mass or more, based on 100 parts by mass of solid components of the mixed dispersion. preferable. Further, the amount of electrolyte added is preferably 25 parts by mass or less, more preferably 15 parts by mass or less, particularly preferably 10 parts by mass or less.
The aggregation temperature when performing aggregation by adding an electrolyte is preferably 20°C or higher, particularly preferably 30°C or higher, and preferably 70°C or lower, particularly preferably 60°C or lower.

The time required for aggregation is optimized depending on the device shape and processing scale, but in order for the particle size of the toner base particles to reach the target particle size, it is necessary to hold the toner at the predetermined temperature for at least 30 minutes or more. is preferred. The temperature may be raised at a constant rate or may be raised in steps until the predetermined temperature is reached.

(Aging process)
In the aging step, the mixed dispersion obtained in the aggregation step is heated under sufficient stirring conditions.
In the case of a core-shell structure, the temperature of the aging step is preferably at least the Tg of the primary particles of the polymer of the binder resin of the shell, more preferably at least 5° C. higher than the Tg of the primary particles of the polymer of the binder resin of the shell. be. The time required for the aging step varies depending on the shape of the target toner base particles, but is preferably 0.1 to 10 hours, particularly preferably 0.1 to 10 hours after reaching the Tg of the primary polymer particles of the shell binder resin. It is desirable to hold the temperature for 0.5 to 5 hours.

After the aggregation step, preferably before or during the ripening step, it is preferable to add a surfactant, adjust the pH, or use both in combination. As the surfactant used here, one or more types of emulsifiers can be selected from emulsifiers that can be used when producing primary polymer particles. It is preferable to use the same emulsifier.

When adding a surfactant, the amount added is not limited, but is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and more preferably is 20 parts by mass or less, more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less.

By adding a surfactant or adjusting the pH after the aggregation process and before the completion of the ripening process, it is possible to suppress the agglomeration of particle aggregates obtained in the aggregation process, and improve the aging process. Coarse particle generation can be suppressed in some cases.

By controlling the time of the aging process, we can produce toner in various shapes depending on the purpose, such as a grape shape in which the primary polymer particles maintain an aggregated shape, a potato shape in which the fusion is advanced, and a spherical shape in which the fusion is further advanced. Base particles can be manufactured.

<How to add external additives>
Examples of methods for adding external additives include a method using a high-speed stirrer such as a Henschel mixer, a method using a device capable of applying compressive shear stress, and the like.
The toner can be produced by a one-step external addition method in which all external additives are simultaneously added to toner base particles. It can also be produced by a stepwise external addition method in which each external additive is externally added.
In order to prevent temperature rise during external addition, examples include installing a cooling device in the container and adding externally in stages.

[Usage form]
The present toner may be used in the form of either a two-component developer in which the toner is used together with a carrier, or a magnetic or non-magnetic one-component developer in which a carrier is not used.
When used as a two-component developer, known carriers such as magnetic substances such as iron powder, magnetite powder, and ferrite powder, or their surfaces coated with resin, and magnetic carriers can be used. As the coating resin for the resin coating carrier, commonly known styrene resins, acrylic resins, styrene-acrylic copolymer resins, silicone resins, modified silicone resins, fluororesins, or mixtures thereof can be used.

[Cartridge/image forming device]
Next, an embodiment of an image forming apparatus (image forming apparatus of the present invention) having the present toner will be described. However, the embodiments are not limited to the following description, and can be arbitrarily modified and implemented without departing from the gist of the present invention.

The image forming apparatus includes an electrophotographic photoreceptor, a charging device, an exposure device, a developing device, and a toner, and is further provided with a transfer device, a cleaning device, and a fixing device as necessary.

The electrophotographic photoreceptor is not particularly limited, but for example, a drum-shaped photoreceptor in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support can be used.
The charging device uniformly charges the surface of the electrophotographic photoreceptor to a predetermined potential. Typical charging devices include non-contact corona charging devices such as corotrons and scorotrons, and contact-type charging devices.

The type of exposure device is not particularly limited as long as it can expose the electrophotographic photoreceptor to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor.
The transfer device applies a predetermined voltage value (transfer voltage) with a polarity opposite to the charged potential of the toner, and transfers the toner image formed on the electrophotographic photoreceptor onto recording paper (paper, medium). The type of transfer device is not particularly limited, and a device using any method such as corona transfer, roller transfer, etc. can be used.
The cleaning device scrapes off residual toner adhering to the electrophotographic photoreceptor with a cleaning member and collects the residual toner. However, if there is little or almost no toner remaining on the surface of the electrophotographic photoreceptor, the cleaning device may not be provided. There are no particular limitations on the cleaning device, and any cleaning device such as a brush cleaner, magnetic roller cleaner, blade cleaner, etc. can be used.

In the image forming apparatus configured as described above, images are recorded in the following manner.

First, the surface (photosensitive surface) of the electrophotographic photoreceptor is charged to a predetermined potential by a charging device. At this time, charging may be performed using a DC voltage, or charging may be performed by superimposing an AC voltage on a DC voltage.
Subsequently, the photosensitive surface of the charged electrophotographic photoreceptor is exposed by an exposure device according to the image to be recorded, thereby forming an electrostatic latent image on the photosensitive surface. Then, the electrostatic latent image formed on the photosensitive surface of the electrophotographic photosensitive member is developed by a developing device.
The developing device thins the toner using a regulating member such as a developing blade, triboelectrically charges the toner to a predetermined polarity, carries the toner on a developing roller, and transports the toner to contact the surface of an electrophotographic photoreceptor.

When the charged toner carried on the developing roller comes into contact with the surface of the electrophotographic photoreceptor, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the electrophotographic photoreceptor. This toner image is then transferred onto recording paper or the like by a transfer device. Thereafter, toner remaining on the photosensitive surface of the electrophotographic photosensitive member without being transferred is removed by a cleaning device.
After the toner image is transferred to a printing medium such as recording paper, the final image is obtained by passing through a fixing device and thermally fixing the toner image onto the printing medium such as recording paper.
Note that, in addition to the above-described configuration, the image forming apparatus may have a configuration that can perform a static elimination process, for example. The static elimination process is a process in which static electricity is removed from the electrophotographic photoreceptor by exposing the electrophotographic photoreceptor to light.

Further, the image forming apparatus may be configured in a further modified manner, for example, it may be configured to perform processes such as a pre-exposure process and an auxiliary charging process, it may be configured to perform offset printing, or it may be configured to perform multiple types of printing. A full color tandem system configuration using toner may also be used.

Note that an integrated cartridge (hereinafter referred to as a "toner cartridge") is a combination of a member that stores toner and one or more of a charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a fixing device. ''), and this toner cartridge may be configured to be detachable from the main body of an image forming apparatus such as a copying machine or a laser beam printer.
The present toner is applied to this toner cartridge to constitute the toner cartridge of the present invention.

[Print media]
There are no particular restrictions on the printing media that can be printed using this toner, including general printing paper (including thick paper, postcards, envelopes, plain paper, thin paper, etc.), resins (plastics) such as PET, and metals. Any material commonly used in image forming apparatuses may be used, such as coated paper, OHP sheet, OHP film, and tracing paper. Among these, the present toner has excellent adhesion to PET coated paper, and is therefore suitable for printed matter using PET coated paper.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.
In the following Examples and Comparative Examples, "parts" simply means "parts by mass."

The methods for measuring various physical properties are as follows.

<Median diameter (D50) of primary polymer particles, wax, and colorant (pigment)>
The median diameter (D50) of the primary polymer particles, wax, and colorant (pigment) was determined using Nikkiso Co., Ltd. model MicrotracNanotrac150 (hereinafter referred to as Nanotrac) and the company's analysis software MicrotracParticle Analyzer Ver10.1.2-0.19EE. It was measured using
Using ion-exchanged water with an electrical conductivity of 0.5 μS/cm as a solvent, using the measurement conditions of solvent refractive index: 1.333, measurement time: 120 seconds, and number of measurements: 5 times, according to the method described in the instruction manual. It was measured and the average value was calculated. Other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: spherical, and density: 1.04.

<Volume median particle size of toner (Dv50)>
The volume median particle diameter (Dv50) of the toner was measured using Multisizer III (aperture diameter: 100 μm or less, abbreviated as Multisizer) manufactured by Beckman Coulter. The measurement was carried out by dispersing Isoton II manufactured by the same company as a dispersion medium so that the dispersoid concentration was 0.03% by mass. The measurement results were shown as "volume particle size".

<Average circularity and number % of particles with a particle size of 1.0 μm or less>
The average circularity and the number % of particles with a particle size of 1.0 μm or less were determined by dispersing the dispersoid in a dispersion medium (Celsheath: manufactured by Malvern Co., Ltd.) to 5,720 to 7,140 particles/μL, and using a flow type particle analyzer ( Measurement was carried out in HPF mode using FPIA3000 (manufactured by Malvern) under conditions of an HPF analysis amount of 0.35 LL and an HPF detection amount of 2000 to 2500 pieces. The measurement results were shown as "circularity" and "number % of 1.0 μm or less".

<Mass average molecular weight (Mw)>
After the styrene acrylic dispersion described below was freeze-dried to remove water, the THF-soluble components were measured by gel permeation chromatography (GPC) under the following conditions.
Equipment: Tosoh GPC equipment HLC-8320
Column: TOSOH TSKgel SuperHM-H (diameter 6m x length 150mm x 2)
Solvent: THF
Column temperature: 40℃
Flow rate: 0.5mL/min Sample concentration: 0.1% by mass
Calibration curve: standard polystyrene

<Emulsion solid content concentration>
The emulsion solid content concentration was determined by heating 2 g of a sample at 195° C. for 90 minutes to evaporate water using an infrared moisture meter FD-610 manufactured by Kett Scientific Research Institute.

<Glass transition temperature (Tg)>
The glass transition temperature of the amorphous polyester resin is determined by using a differential scanning calorimeter (Shimadzu Corporation, "DSC-60") between the baseline of the chart and the tangent of the endothermic curve at a heating rate of 5°C/min. Measured from the intersection of The measurement sample was measured by weighing 10 mg±0.5 mg into an aluminum pan, melting the sample at 100° C. above the glass transition temperature for 10 minutes, and rapidly cooling the sample using dry ice.

<Softening temperature (T4)>
The softening temperature of the amorphous polyester resin was determined using a flow tester (manufactured by Shimadzu Corporation, "CFT-500D") using a nozzle of 1 mmφ x 10 mm, a load of 294 N, and a constant temperature increase at a temperature increase rate of 3°C/min. The temperature at which 1/2 of 1.0 g of the resin sample flowed out was measured, and this was taken as the softening temperature.

<Acid value>
The acid value of the amorphous polyester resin was measured as follows.
Approximately 0.2 g of the measurement sample was accurately weighed in an Erlenmeyer flask with branches (a(g)), 20 mL of benzyl alcohol was added, and the mixture was heated in a nitrogen atmosphere with a heater at 230° C. for 15 minutes to dissolve the measurement sample. After cooling to room temperature, 20 mL of chloroform and several drops of cresol red solution were added, and titration was performed with a 0.02N KOH solution (titer amount = b (mL), titer of KOH solution = p). A blank measurement was performed in the same manner (titer amount = c (mL)), and the acid value was calculated according to the following formula.
Acid value (mgKOH/g) = {(b-c) x 0.02 x 56.11 x p}/a

<Storage modulus (G')>
The solid content obtained by vacuum drying the amorphous polyester dispersion obtained in the following example was used as the resin used in the dynamic viscoelasticity measurement.
Dynamic viscoelasticity measurements were performed using a rheometer ARES manufactured by TA Instruments as follows.
Approximately 1.3 g of the sample was placed in a jig for a diameter of 25 mm, and pressed for 10 minutes at a load of 30 kg using a press heated to 50° C. to form a pellet. The obtained pellets were placed in a measuring device equipped with a circular parallel plate having a diameter of 25 mm, and while the temperature was raised to 120° C., the upper plate was lowered to adjust the thickness of the pellets to 3.0 to 3.5 mm.
After that, the temperature was lowered, measurement frequency was 6.28 rad/sec, initial temperature was 40℃, delay time before measurement was 3 minutes, automatic tension adjustment (pulling direction, initial force was 0, automatic tension sensitivity was 2.0 g, automatic tension switching elastic modulus) 1.0E+08Pa), a final temperature of 150°C, a temperature increase rate of 4°C/min, a measurement cycle time of 1 minute, an initial strain of 0.1%, and automatic strain adjustment.

Next, the wax dispersion, colorant dispersion, and polymer primary particle dispersion (styrene acrylic dispersion, amorphous polyester dispersion) used in Examples and Comparative Examples will be explained.

<Wax dispersion W1>
As waxes, 30 parts of ester wax 1 (chemical formula: C ₂ 1H ₄₃ COOC ₂₂ H ₄₅ ), 1.93 parts of a 20% aqueous solution of sodium dodecylbenzenesulfonate (hereinafter abbreviated as 20% DBS aqueous solution), and 68.7 parts of demineralized water were used. The mixture was placed in a CSTR type stirring bed equipped with a three-stage inclined paddle blade, heated to 90° C. in the stirring bed, and mixed for 20 minutes.
Next, while heating this dispersion to 90°C, circulation emulsification was performed using a valve homogenizer (manufactured by Gorlin, model 15-M-8PA) under a pressure condition of 25 MPa, and the particle size was measured using a nanotrack. Wax dispersion W1 (emulsion solid content concentration: 30.5%) was prepared by dispersing until the diameter (D50) became 245 nm.

<Wax dispersion W2>
Wax dispersion W2 ( An emulsion solid content concentration: 30.5%) was prepared.

<Wax dispersion W3>
Ester wax 3 (NOF Corporation product name: WEP-3, melting point 73°C, acid value 0.1 mgKOH/g, hydroxyl value 3 mgKOH/g or less (all catalog values)) 30 parts, decaglycerin decabehenate ( Same as W1 above except that 0.24 parts of Mitsubishi Chemical Foods Co., Ltd. product name: B100D, hydroxyl value 27, melting point 70°C), 1.93 parts of 20% DBS aqueous solution, and 67.83 parts of demineralized water were used. A wax dispersion W3 (emulsion solid content concentration: 30.2%) was prepared by the method.

<Colorant dispersion liquid G1>
In a stirrer container equipped with propeller blades, 24 parts of Pigment Blue 15:3 (manufactured by Dainichiseika Chemical Co., Ltd., cyan pigment (copper phthalocyanine complex)) as a coloring agent, 1 part of a 20% DBS aqueous solution, and nonionic surfactant. 9 parts of Emulgen 120 (manufactured by Kao Corporation) and 67 parts of ion-exchanged water having a conductivity of 2 μS/cm were added and predispersed to obtain a pigment premix liquid. The premix liquid was supplied as a raw material slurry to a wet bead mill for dispersion. The inner diameter of the stator of the wet bead mill was 120 mmφ, the diameter of the separator was 60 mmφ, and zirconia beads with a diameter of 0.1 mm were used as the dispersion media. The effective internal volume of the stator was approximately 2 liters, and the media filling volume was 1.4 liters, so the media filling rate was 70%. With the rotational speed of the rotor constant (circumferential speed of the rotor tip approximately 11 m/sec), the raw material slurry is supplied from the supply port at a supply rate of approximately 40 liters/hr using a non-pulsating metering pump, and when a predetermined particle size is reached. Dispersion was stopped at , and a colorant dispersion G1 was obtained from the discharge port.
Note that during operation, cooling water at about 10° C. was circulated from the jacket. The dispersion median diameter (D50) of the colorant was 83 nm, the solid content of the dispersion was 34.3%, and the solid content of the colorant was 24.1%.

<Styrene acrylic dispersion A1>
70.7 parts of wax dispersion W2, 269 parts of demineralized water, and 0.5% iron (II) sulfate 7 were placed in a reactor equipped with a stirring device, a heating/cooling device, a concentration device, and a device for charging each raw material/auxiliary agent. 0.02 part of a hydrate aqueous solution was charged, and the temperature was raised to 70° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and emulsifier solution was added over 300 minutes while stirring to obtain an aqueous monomers and emulsifier solution. At this time, the time when addition of the mixture was started was defined as the start of polymerization, and the following initiator aqueous solution was added dropwise from 30 minutes to 420 minutes after the start of polymerization. Next, the temperature was raised to an internal temperature of 90° C. 300 minutes after the start of polymerization. The following iron sulfate aqueous solution was added 330 minutes after the start of polymerization. Heating and stirring was continued until 540 minutes from the start of polymerization.

(monomers)
・Styrene 65.5 parts ・Butyl acrylate 34.5 parts ・Acrylic acid 0.95 parts ・Trichlorobromomethane 1.0 parts ・Hexanedioldiacrylate 0.60 parts

(Emulsifier aqueous solution)
・20% DBS aqueous solution 1.0 parts ・Demineralized water 66.7 parts (initiator aqueous solution)
・8% hydrogen peroxide aqueous solution 15.5 parts ・8% L-(+) ascorbic acid aqueous solution 30.1 parts (iron sulfate aqueous solution)
・0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After the polymerization reaction was completed, it was cooled to obtain a milky white styrene acrylic dispersion A1. The median diameter (D50) of the polymer primary particles measured using NanoTrack was 231 nm. The mass average molecular weight (Mw) of the polymer primary particles was 74,822. Further, the acid value of this styrene acrylic resin was calculated from the amount of acrylic acid added and was 7.3 mgKOH/g.

<Styrene acrylic dispersion A2>
70.7 parts of wax dispersion W2, 269 parts of demineralized water, and 0.5% iron (II) sulfate 7 were placed in a reactor equipped with a stirring device, a heating/cooling device, a concentration device, and a device for charging each raw material/auxiliary agent. 0.02 part of a hydrate aqueous solution was charged, and the temperature was raised to 70° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and emulsifier solution was added over 300 minutes while stirring to obtain an aqueous monomers and emulsifier solution. At this time, the time when addition of the mixture was started was defined as the start of polymerization, and the following initiator aqueous solution was added dropwise from 30 minutes to 420 minutes after the start of polymerization. Next, the temperature was raised to an internal temperature of 90° C. 300 minutes after the start of polymerization. The following iron sulfate aqueous solution was added 330 minutes after the start of polymerization. Heating and stirring was continued until 540 minutes from the start of polymerization.

(monomers)
・Styrene 68.2 parts ・Butyl acrylate 31.8 parts ・Acrylic acid 0.95 parts ・Trichlorobromomethane 1.0 parts ・Hexanedioldiacrylate 0.60 parts

(Emulsifier aqueous solution)
・20% DBS aqueous solution 1.0 parts ・Demineralized water 66.7 parts (initiator aqueous solution)
・8% hydrogen peroxide aqueous solution 15.5 parts ・8% L-(+) ascorbic acid aqueous solution 30.1 parts (iron sulfate aqueous solution)
・0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After the polymerization reaction was completed, it was cooled to obtain a milky white styrene acrylic dispersion A2. The median diameter (D50) of the polymer primary particles measured using NanoTrack was 234 nm. The mass average molecular weight (Mw) of the polymer primary particles was 94,164. Further, the acid value of this styrene acrylic resin was calculated from the amount of acrylic acid added and was 7.3 mgKOH/g.

<Styrene acrylic dispersion A3>
70.7 parts of wax dispersion W1, 269 parts of demineralized water, and 0.5% iron (II) sulfate 7 were placed in a reactor equipped with a stirring device, a heating/cooling device, a concentration device, and a device for charging each raw material/auxiliary agent. 0.02 part of a hydrate aqueous solution was charged, and the temperature was raised to 70° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and emulsifier solution was added over 300 minutes while stirring to obtain an aqueous monomers and emulsifier solution. At this time, the time when addition of the mixture was started was defined as the start of polymerization, and the following initiator aqueous solution was added dropwise from 30 minutes to 420 minutes after the start of polymerization. Next, the temperature was raised to an internal temperature of 90° C. 300 minutes after the start of polymerization. The following iron sulfate aqueous solution was added 330 minutes after the start of polymerization. Heating and stirring was continued until 540 minutes from the start of polymerization.

(monomers)
・Styrene 68.2 parts ・Butyl acrylate 31.8 parts ・Acrylic acid 0.95 parts ・Trichlorobromomethane 1.0 parts ・Hexanedioldiacrylate 0.60 parts

(Emulsifier aqueous solution)
・20% DBS aqueous solution 1.0 parts ・Demineralized water 66.7 parts (initiator aqueous solution)
・8% hydrogen peroxide aqueous solution 15.5 parts ・8% L-(+) ascorbic acid aqueous solution 30.1 parts (iron sulfate aqueous solution)
・0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After the polymerization reaction was completed, it was cooled to obtain a milky white styrene acrylic dispersion A3. The median diameter (D50) of the polymer primary particles measured using NanoTrack was 216 nm. The mass average molecular weight (Mw) of the polymer primary particles was 80,649. Further, the acid value of this styrene acrylic resin was calculated from the amount of acrylic acid added and was 7.3 mgKOH/g.

<Styrene acrylic dispersion A4>
35.3 parts of wax dispersion W1, 258 parts of demineralized water, and 0.5% iron (II) sulfate 7 were placed in a reactor equipped with a stirring device, a heating/cooling device, a concentration device, and a device for charging each raw material/auxiliary agent. 0.02 part of a hydrate aqueous solution was charged, and the temperature was raised to 70° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and emulsifier solution was added over 300 minutes while stirring to obtain an aqueous monomers and emulsifier solution. At this time, the time when addition of the mixture was started was defined as the start of polymerization, and the following initiator aqueous solution was added dropwise from 30 minutes to 420 minutes after the start of polymerization. Next, the temperature was raised to an internal temperature of 90° C. 300 minutes after the start of polymerization. The following iron sulfate aqueous solution was added 330 minutes after the start of polymerization. Heating and stirring was continued until 540 minutes from the start of polymerization.

(monomers)
・Styrene 70.0 parts ・Butyl acrylate 30.0 parts ・Acrylic acid 0.95 parts ・Trichlorobromomethane 1.0 parts ・Hexanedioldiacrylate 0.60 parts

(Emulsifier aqueous solution)
・20% DBS aqueous solution 1.0 parts ・Demineralized water 66.7 parts (initiator aqueous solution)
・8% hydrogen peroxide aqueous solution 15.5 parts ・8% L-(+) ascorbic acid aqueous solution 30.1 parts (iron sulfate aqueous solution)
・0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After the polymerization reaction was completed, it was cooled to obtain a milky white styrene acrylic dispersion A4. The median diameter (D50) of the polymer primary particles measured using NanoTrack was 230 nm. The mass average molecular weight (Mw) of the polymer primary particles was 81,608. Further, the acid value of this styrene acrylic resin was calculated from the amount of acrylic acid added and was 7.3 mgKOH/g.

<Styrene acrylic dispersion A5>
34.8 parts of wax dispersion W3, 258 parts of demineralized water, and 0.5% iron (II) sulfate 7 were placed in a reactor equipped with a stirring device, a heating/cooling device, a concentration device, and a device for charging each raw material/auxiliary agent. 0.02 part of a hydrate aqueous solution was charged, and the temperature was raised to 70° C. under a nitrogen stream while stirring.
Thereafter, the following mixture of monomers and emulsifier solution was added over 300 minutes while stirring to obtain an aqueous monomers and emulsifier solution. At this time, the time when addition of the mixture was started was defined as the start of polymerization, and the following initiator aqueous solution was added dropwise from 30 minutes to 420 minutes after the start of polymerization. Next, the temperature was raised to an internal temperature of 90° C. 300 minutes after the start of polymerization. The following iron sulfate aqueous solution was added 330 minutes after the start of polymerization. Heating and stirring was continued until 540 minutes from the start of polymerization.

(monomers)
・Styrene 76.8 parts ・Butyl acrylate 23.2 parts ・Acrylic acid 1.5 parts ・Trichlorobromomethane 1.0 parts ・Hexanediol diacrylate 0.60 parts

(Emulsifier aqueous solution)
・20% DBS aqueous solution 1.0 parts ・Demineralized water 66.7 parts (initiator aqueous solution)
・8% hydrogen peroxide aqueous solution 15.5 parts ・8% L-(+) ascorbic acid aqueous solution 30.1 parts (iron sulfate aqueous solution)
・0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 part

After the polymerization reaction was completed, it was cooled to obtain a milky white styrene acrylic dispersion A5. The median diameter (D50) of the polymer primary particles measured using NanoTrack was 234 nm. The mass average molecular weight (Mw) of the polymer primary particles was 75,601. In addition, the acid value of this styrene acrylic resin is 11.4 mgKOH/g when calculated from the amount of acrylic acid added, and the storage modulus (G') of the resin is G' (70°C) = 1120000 Pa, G' (100 °C) = 10,800 Pa.

<Amorphous polyester resin>
Amorphous polyester resins A, B, C, and D were produced in the following manner.
A polyhydric carboxylic acid component, a polyhydric alcohol component, and a polymerization catalyst having the charge compositions shown in Table 1 were charged into a reaction vessel equipped with a distillation column. Note that the amount of the polymerization catalyst is the amount (ppm) relative to the acid component.
Next, the rotational speed of the stirring blade in the reaction vessel was maintained at 120 rpm, and the temperature was started to increase so that the temperature in the reaction system reached 265° C., and this temperature was maintained to carry out the esterification reaction. After no water is distilled out of the reaction system and the esterification reaction is completed, the temperature inside the reaction system is lowered and maintained at 240°C, and the pressure inside the reaction vessel is reduced over about 40 minutes to bring the degree of vacuum to 133 Pa, and the reaction is continued. Polycondensation reaction was carried out while distilling the alcohol component from the system.
The viscosity of the reaction system increased with the reaction, and as the viscosity increased, the degree of vacuum was increased, and the condensation reaction was carried out until the torque of the stirring blade reached a value indicating the desired softening temperature. Then, when a predetermined torque was exhibited, stirring was stopped, the reaction system was returned to normal pressure, and the reactant was taken out (discharged) from the reaction vessel by pressurizing with nitrogen to obtain each amorphous polyester resin.
The physical properties (glass transition temperature, softening temperature, acid value) of the obtained amorphous polyester resins A, B, C, and D were measured. These results are shown in Table 1.

In Table 1, "BPA-PO2.3 mol addition" and "BPA-EO 2.3 mol addition" mean the following.
BPA-PO 2.3 mol addition: Bisphenol A propylene oxide derivative (polyoxypropylene-(2.3)-2,2-bis(4-hydroxyphenyl)propane (PO 2.3 mol adduct))
BPA-EO 2.3 mol addition: Ethylene oxide derivative of bisphenol A (polyoxyethylene-(2.3)-2,2-bis(4-hydroxyphenyl)propane, (EO 2.3 mol adduct))

<Amorphous polyester dispersion P1>
12.5 parts of amorphous polyester resin A and 12.5 parts of amorphous polyester resin B were dissolved in 75 parts of methyl ethyl ketone (MEK), 19.9 g of 5% ammonia aqueous solution was added, and the mixture was stirred uniformly with a stirrer. A resin solution was prepared.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by vacuum distillation at 80° C. using an aspirator to obtain an amorphous polyester dispersion P1. The median diameter (D50) of the primary polymer particles of the polyester resin particles in the polyester dispersion P1 was measured using a nanotrack and found to be 182 nm. The storage modulus (G') of the resin was G' (70°C) = 1008200 Pa and G' (100°C) = 1176 Pa.

<Amorphous polyester dispersion P2>
8.3 parts of amorphous polyester resin A and 16.7 parts of amorphous polyester resin B were dissolved in 75 parts of methyl ethyl ketone (MEK), and 18.9 g of 5% ammonia aqueous solution was added and stirred uniformly with a stirrer. A resin solution was prepared.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by distillation under reduced pressure at 80° C. using an aspirator to obtain an amorphous polyester dispersion P2. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P2 was measured using a nanotrack and found to be 190 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 505390 Pa and G' (100°C) = 987 Pa.

<Amorphous polyester dispersion P3>
16.7 parts of amorphous polyester resin A and 8.3 parts of amorphous polyester resin B were dissolved in 75 parts of methyl ethyl ketone (MEK), 20.8 g of 5% ammonia aqueous solution was added, and the mixture was stirred uniformly with a stirrer. A resin solution was prepared.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by vacuum distillation at 80° C. using an aspirator to obtain an amorphous polyester dispersion P3. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P3 was measured using a nanotrack and found to be 188 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 1,568,900 Pa, and G' (100°C) = 1,990 Pa.

<Amorphous polyester dispersion P4>
A resin solution was prepared by dissolving 25 parts of amorphous polyester resin C in 75 parts of methyl ethyl ketone (MEK), adding 22.7 g of a 5% ammonia aqueous solution, and stirring uniformly with a stirrer.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by distillation under reduced pressure at 80° C. using an aspirator to obtain an amorphous polyester dispersion P4. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P4 was measured using a nanotrack and found to be 200 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 751970 Pa and G' (100°C) = 709 Pa.

<Amorphous polyester dispersion P5>
A resin solution was prepared by dissolving 25 parts of amorphous polyester resin D in 75 parts of methyl ethyl ketone (MEK), adding 24.6 g of a 5% ammonia aqueous solution, and stirring uniformly with a stirrer.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by vacuum distillation at 80° C. using an aspirator to obtain an amorphous polyester dispersion P5. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P5 was measured using a nanotrack and found to be 212 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 601120 Pa and G' (100°C) = 1632 Pa.

<Amorphous polyester dispersion P6>
A resin solution was prepared by dissolving 25 parts of amorphous polyester resin A in 75 parts of methyl ethyl ketone (MEK), adding 22.7 g of a 5% ammonia aqueous solution, and stirring uniformly with a stirrer.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by vacuum distillation at 80° C. using an aspirator to obtain an amorphous polyester dispersion P6. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P5 was measured using a nanotrack and found to be 180 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 31,750,000 Pa, and G' (100°C) = 5317 Pa.

<Amorphous polyester dispersion P7>
A resin solution was prepared by dissolving 25 parts of amorphous polyester resin B in 75 parts of methyl ethyl ketone (MEK), adding 17.0 g of a 5% ammonia aqueous solution, and stirring uniformly with a stirrer.
Next, 100 parts of demineralized water was placed in a round bottom flask, and the prepared resin solution was further added thereto, followed by dispersion using a homogenizer (Model T25 manufactured by IKA) for 10 minutes at a rotation speed of 8000 rpm.
Thereafter, the solvent was removed by vacuum distillation at 80° C. using an aspirator to obtain an amorphous polyester dispersion P3. The median diameter (D50) of the primary polymer particles of the amorphous polyester resin particles in the amorphous polyester dispersion P5 was measured using a nanotrack and found to be 190 nm. The storage modulus (G') of the amorphous polyester resin was G' (70°C) = 336110 Pa and G' (100°C) = 427 Pa.

[Example 1]
Toner C1 was produced as follows.

In a mixer equipped with a stirring device, a heating/cooling device, and a device for charging each raw material/auxiliary agent, add 90.0 parts (solid content) of styrene acrylic dispersion A1 and 0.17 parts (solid content) of 20% DBS aqueous solution. , 0.56 parts (solid content) of a 5% aqueous solution of iron (II) sulfate heptahydrate, and 4.4 parts (solid content) of colorant dispersion G1 were added in this order with stirring. The internal temperature was raised to 39.0°C over 60 minutes, and then to 42.0°C over 180 minutes.
Next, add 10.0 parts (solid content) of amorphous polyester dispersion P1 and 0.3 parts (solid content (amount equivalent to 2 parts per 100 parts of amorphous polyester) of 20% DBS aqueous solution). A mixture of these was added dropwise over 30 minutes. 30 minutes after the dropping was completed, the pH in the system was adjusted to 8.3 using a 4.8% aqueous potassium hydroxide solution, and 6.0 parts (solid content) of a 20% aqueous DBS solution and 232 parts of deionized water were added. After adding .4 parts, the temperature was raised to 65°C over 90 minutes, and then to 73°C over 60 minutes. Thereafter, the mixture was cooled to 30° C. over 30 minutes.

The obtained dispersion liquid was extracted, and No. 1 manufactured by Toyo Roshi Co., Ltd. Suction filtration was performed using an aspirator using 5C filter paper. The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), and ion-exchanged water with an electrical conductivity of 1 μS/cm was added and stirred to uniformly disperse it, followed by stirring for 30 minutes. After repeating this process until the electrical conductivity of the filtrate reached 2 μS/cm, the resulting cake was dried for 48 hours in a blower dryer set at 40° C. to obtain toner base particles B1.

Polymer/silica composite particles ATLAS100 (manufactured by Cabot, silica/polymer ratio = 70/30, true specific gravity = 1.7 g/cm ³ , octahydropenta 0.5 parts of titania/silica composite oxide particles STX50.1 (manufactured by Nippon Aerosil Co., Ltd.), and 0.4 parts of small particle size silica RY200L (manufactured by Nippon Aerosil Co., Ltd.) were added, and a Henschel mixer was added. The mixture was stirred and mixed for 15 minutes at 3000 rpm, and then sieved to obtain toner C1.
The core/shell structure of this toner C1 is as shown in Table 3.
The volume median particle diameter, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C1 were measured. The results are shown in Table 2.

[Example 2]
Toner C2 was produced in the same manner as toner C1 in Example 1, except that styrene acrylic dispersion A1 was replaced with styrene acrylic dispersion A2.
The core/shell structure of this toner C2 is as shown in Table 3.
The volume median particle diameter, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C2 were measured. The results are shown in Table 2.

[Example 3]
Toner C3 was produced in the same manner as toner C1, except that in Example 1, styrene acrylic dispersion A1 was changed to styrene acrylic dispersion A2, and amorphous polyester dispersion P1 was changed to amorphous polyester dispersion P2. did.
The core/shell structure of this toner C3 is as shown in Table 3.
The volume median particle diameter, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C3 were measured. The results are shown in Table 2.

[Example 4]
Toner C4 was produced in the same manner as toner C1, except that in Example 1, styrene acrylic dispersion A1 was changed to styrene acrylic dispersion A2, and amorphous polyester dispersion P1 was changed to amorphous polyester dispersion P3. did.
The core/shell structure of this toner C4 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C4 were measured. The results are shown in Table 2.

[Example 5]
In Example 1, styrene acrylic dispersion A1 was changed to 95.0 parts (solid content) of styrene acrylic dispersion A3, and amorphous polyester dispersion P1 was changed to 5.0 parts (solid content) of amorphous polyester dispersion P4. Toner C5 was produced in the same manner as toner C1 except for the following.
The core/shell structure of this toner C5 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C5 were measured. The results are shown in Table 2.

[Example 6]
In Example 1, styrene acrylic dispersion A1 was changed to 95.0 parts (solid content) of styrene acrylic dispersion A3, and amorphous polyester dispersion P1 was changed to 5.0 parts (solid content) of amorphous polyester dispersion P5. Toner C6 was produced in the same manner as toner C1 except for the following.
The core/shell structure of this toner C6 is as shown in Table 3.
The volume median particle diameter, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C6 were measured. The results are shown in Table 2.

[Comparative example 1]
Toner C7 was produced as follows.

In a mixer equipped with a stirring device, a heating/cooling device, and a device for charging each raw material/auxiliary agent, add 85.0 parts (solid content) of styrene acrylic dispersion A4 and 0.17 parts (solid content) of 20% DBS aqueous solution. , 0.56 parts (solid content) of a 5% aqueous solution of iron (II) sulfate heptahydrate, and 4.4 parts (solid content) of colorant dispersion G1 were added in this order with stirring. The internal temperature was raised to 41.0°C over 60 minutes, and then to 45.0°C over 180 minutes.
Next, 15.0 parts (solid content) of styrene acrylic dispersion A5 was added dropwise over 30 minutes. After 30 minutes, 4.0 parts of 20% DBS aqueous solution (solid content) and 23 parts of deionized water were added, and the temperature was raised to 80°C over 90 minutes, and then to 83°C over 60 minutes. . Thereafter, the mixture was cooled to 30° C. over 30 minutes.

The obtained dispersion liquid was extracted, and No. 1 manufactured by Toyo Roshi Co., Ltd. Suction filtration was performed using an aspirator using 5C filter paper. The cake remaining on the filter paper was transferred to a stainless steel container equipped with a stirrer (propeller blade), ion-exchanged water with an electrical conductivity of 1 μS/cm was added and stirred to uniformly disperse it, and then stirred for 30 minutes. After repeating this process until the electrical conductivity of the filtrate reached 2 μS/cm, the resulting cake was dried for 48 hours in a blower dryer set at 40° C. to obtain toner base particles B7.

Polymer/silica composite particles ATLAS100 (manufactured by Cabot Corporation, silica/polymer ratio = 70/30, true specific gravity = 1.7 g/cm ³ , octahydropenta 0.5 parts of titania/silica composite oxide particles STX50.1 (manufactured by Nippon Aerosil Co., Ltd.), and 0.4 parts of small particle size silica RY200L (manufactured by Nippon Aerosil Co., Ltd.) were added, and a Henschel mixer was added. The mixture was stirred and mixed for 15 minutes at 3000 rpm, and then sieved to obtain toner C7.
The core/shell structure of this toner C7 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C7 were measured. The results are shown in Table 2.

[Comparative example 2]
In Example 1, styrene acrylic dispersion A1 was changed to 95.0 parts (solid content) of styrene acrylic dispersion A3, and amorphous polyester dispersion P1 was changed to 5.0 parts (solid content) of amorphous polyester dispersion P6. Toner C8 was produced in the same manner as toner C1 except for the following changes.
The core/shell structure of this toner C8 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C8 were measured. The results are shown in Table 2.

[Comparative example 3]
In Example 1, styrene acrylic dispersion A1 was changed to 85.0 parts (solid content) of styrene acrylic dispersion A2, and amorphous polyester dispersion P1 was changed to 15.0 parts (solid content) of amorphous polyester dispersion P6. Toner C9 was produced in the same manner as toner C1 except for the following changes.
The core/shell structure of this toner C9 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C9 were measured. The results are shown in Table 2.

[Comparative example 4]
In Example 1, styrene acrylic dispersion A1 was changed to 90.0 parts (solid content) of styrene acrylic dispersion A2, and amorphous polyester dispersion P1 was changed to 10.0 parts (solid content) of amorphous polyester dispersion P7. Toner C10 was produced in the same manner as toner C1 except for the following.
The core/shell structure of this toner C10 is as shown in Table 3.
The volume median particle size, average circularity, and number % of particles of 1.0 μm or less of the obtained toner C10 were measured. The results are shown in Table 2.

<Adhesion evaluation (shaving test)>
The obtained toner was printed using a commercially available printer with a printing speed of 16 ppm, a non-magnetic single component, a developing rubber roller, a metal blade, and an organic photoreceptor charged by a charging roller (PCR), with the fixing unit removed, and two toner cartridges. An unfixed toner image with an adhesion amount of about 0.8 mg/cm ² was printed on glossy recording paper (waterproof paper Kareka, manufactured by Kokusai Paper and Pulp Shoji Co., Ltd.), which is a PET coated paper, using the printer.
The heat roll fixing machine has a roller diameter of 27 mm, a nip width of 9 mm, and a fixing speed of 95 mm/sec, has a heater on the upper roller, and has a roller surface made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). The material used was one without silicone oil applied.
The surface temperature of the roller was set at 175° C., and a recording paper carrying an unfixed toner image with an adhesion amount of about 0.8 mg/cm ² was conveyed to the fixing nip section to obtain a fixed image. A scraping test was conducted by scraping the fixed image with a flathead screwdriver installed vertically. The width of the tip of the flathead screwdriver was 1 mm, and the load on the tip was 250 g using a weight. The moving distance was set to 2 cm, and a total of three reciprocating scraping tests were performed. The moving speed was approximately 1 cm/s, and the angle between the moving direction and the tip surface of the flathead screwdriver was 90°. The degree of scratching was visually observed and evaluated using the following criteria. The evaluation results are shown in Table 4.
(Evaluation criteria)
◎: Could not be removed at all.
○: There was one or less small white spots formed by scraping.
Δ: The length of the scraped line was less than 3 mm, or there were multiple small white spots.
×: The length of the cut line was 3 mm or more.

<Low temperature fixability evaluation>
The obtained toner was printed on recording paper (OKI) at a printing speed of 16 ppm, using a commercially available printer equipped with an organic photoconductor charged with a non-magnetic one-component developing rubber roller, a metal blade, and a charging roller (PCR), with the fixing unit removed. An unfixed toner image with a toner adhesion amount of approximately 0.5 mg/cm ² was printed on Excellent White (trade name).
The heat roll fixing machine has a roller diameter of 27 mm, a nip width of 9 mm, and a heater on the upper roller.The roller surface is made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) and is not coated with silicone oil. I used what I didn't have. The surface temperature of the roller was set at 130° C., 135° C., 140° C., and 145° C., and fixing was carried out at each temperature at a fixing speed of 229 mm/sec to obtain a sample for evaluation. The evaluation criteria for the retention test were as follows. The evaluation results are shown in Table 4.
(Evaluation criteria)
○: The fixed image was not offset, and no image defects occurred even when rubbed.
Δ: Fixed image did not offset, but image defects occurred when rubbed.
x: The fixed image was offset.

<Storage stability evaluation>
A metal cylinder with a diameter of 2 cm was placed upright on a flat metal plate, and medicine packaging paper was wrapped around the inside of the cylinder. After 10 g of toner was gently placed into a vertically placed metal cylinder to fill it, a 20 g weight was placed on top of the toner.
Place the metal cylinder on the metal plate in a constant temperature and humidity chamber at a temperature of 50°C and a relative humidity of 55% (normal humidity conditions) and keep it there for 48 hours, or place it in a constant temperature and humidity chamber at a temperature of 50°C and a relative humidity of 80% (high humidity conditions). ) was placed in a high-temperature, high-humidity machine and held for 24 hours. After taking the sample out of the constant temperature and humidity chamber, the metal tube and medicine wrapper were gently removed, and the toner stuck in the cylindrical shape was taken out while standing vertically.
A load was applied in 10 g increments to the fixed toner placed vertically, and the load at which the cylindrical shape collapsed was measured. The measured values of this load were evaluated based on the following evaluation criteria. The evaluation results are shown in Table 4.
(Evaluation criteria)
○: Collapsed under a load of 500 g or less. This means that the toner has weak adhesion and good storage stability.
Δ: It did not collapse under a load of 500g, but collapsed under a load of 1500g or less.
×: It did not collapse under a load of 1500 g. This means that the toner sticks strongly and has poor storage stability.

<Consideration>
From the above Examples and Comparative Examples, by using styrene acrylic resin as the core binder resin and an amorphous polyester resin having an appropriate storage modulus as the shell binder resin, printing media such as PET coated paper It was found that the film has excellent adhesion to the film and low-temperature fixing properties, and does not cause deterioration in storage stability under high humidity.

Claims (6)

A toner having a core-shell structure,
The core and the shell each contain a binder resin,
The binder resin of the core includes styrene acrylic resin,
The binder resin of the shell includes an amorphous polyester resin,
When the binder resin of the shell is measured with a rheometer, the storage modulus at 70°C (G' (70°C)) is 500000 Pa or more, and the storage modulus at 100°C (G' (100°C)) ) is 5000 Pa or less. The toner according to claim 1, wherein the binder resin of the core is a styrene acrylic resin, and the binder resin of the shell is an amorphous polyester resin. The toner according to claim 1 or 2, wherein the content of the amorphous polyester resin is 3% by mass or more and 40% by mass or less based on the total mass of the toner. The toner according to any one of claims 1 to 3, wherein the toner contains wax, and the content of the wax in the toner is 5% by mass or more and 30% by mass or less. A toner cartridge containing the toner according to any one of claims 1 to 4. An image forming apparatus containing the toner according to any one of claims 1 to 4.