JP7614826B2 - Toner and method for producing the same - Google Patents

Description

The present invention relates to a toner used in electrophotography and a method for producing the toner.

Electrophotographic technology is used in copiers, printers, facsimile receiving devices, and the like, and as the equipment develops, the demands from users become more stringent every year.
In recent years, there has been an increasing demand for higher image quality, and in order to meet this demand for higher image quality, it is necessary to improve the coloring power, saturation, and brightness of toner.

In response to such needs, for example, Patent Document 1 discloses a toner containing a naphthol pigment and a quinacridone pigment having an average particle size of 20 nm or more and a specific X-ray diffraction pattern.
Furthermore, Patent Documents 2 to 4 disclose techniques for incorporating a condensed polycyclic pigment in a toner.
Patent Document 2 describes a quinacridone pigment for water-based inks, the pigment having a crystallite size of 27 nm or more.
Furthermore, Patent Document 3 describes a particle growth inhibitor and a dichlorodiketopyrrolopyrrole pigment having a crystallite size of 5 nm to 23 nm.
Furthermore, Patent Document 4 describes a quinacridone pigment for use in water-based inks, the pigment having a crystallite size of 2 to 40 nm.

JP 2006-267741 A JP 2009-275125 A JP 2011-068852 A JP 2009-108199 A

However, when these pigments are used in toners, it has been difficult to achieve the coloring power, brightness and chroma required for the high image quality that has been demanded in recent years.
On the other hand, with conventional toners containing pigments, it has been difficult to improve hot offset resistance to the level required in recent years.

In other words, the present invention aims to provide a toner that has coloring power, brightness, and saturation that can meet the demands of high image quality, and also has high hot offset resistance.

The present invention provides a toner having toner particles containing a binder resin having an ester group and a condensed polycyclic pigment,
The toner is characterized in that, when the toner is subjected to X-ray diffraction measurement using CuKα radiation, a peak A derived from the condensed polycyclic pigment is present at a position of 2θ=5.65°±0.50°, where θ is the Bragg angle, and the crystallite diameter of the crystals to which the peak A belongs is 5 nm or more and 20 nm or less.

As described above, the present invention can provide a toner and a method for producing the toner that has coloring power, brightness, and saturation that can meet the demands of high image quality, as well as high hot offset resistance.

This is an example of a twin screw extruder.

In the present invention, the expressions "xx or more and xx or less" or "xx to xx" that express a numerical range refer to a numerical range including the lower and upper limit endpoints, unless otherwise specified.

The crystalline resin is a resin in which an endothermic peak is observed in differential scanning calorimetry (DSC).
The toner of the present invention has toner particles containing a binder resin having an ester group and a condensed polycyclic pigment,
When the toner is subjected to X-ray diffraction measurement using CuKα radiation, a peak A derived from the condensed polycyclic pigment is present at a position of 2θ=5.65°±0.50°, where θ is the Bragg angle, and the crystallite diameter of the crystals to which the peak A belongs is 5 nm or more and 20 nm or less.

The above toner has coloring power, brightness, and saturation that can meet the needs of high image quality, and also has high hot offset resistance that can be improved to the level desired by the present invention.

First, in the present invention, it is necessary that the pigment is a condensed polycyclic pigment having a peak at 2θ (hereinafter also referred to as "diffraction angle 2θ") of 5.65°±0.50° in an X-ray diffraction spectrum, where θ is the Bragg angle. It is believed that the present invention can achieve the desired level of chroma for the following reasons. That is, the diffraction angle 2θ is determined by the lattice spacing of the crystallites of the condensed polycyclic pigment. On the other hand, the lattice spacing correlates with the energy level of the crystallites.
The energy levels in turn relate to the wavelengths of light absorbed and emitted by the crystallites.
Therefore, the diffraction angle 2θ correlates with the hue angle in the color development from the crystallites, and in order to achieve high image quality, this hue angle must be an angle that contributes to the realization of a wide color gamut and must also have high saturation at this hue angle.
Furthermore, since the pigment is a condensed polycyclic pigment having a peak at a diffraction angle 2θ of 5.65°±0.50°, it is believed that the chroma can be efficiently improved at the hue angle as a magenta pigment, which contributes to the realization of a wide color gamut, and that the chroma can be achieved at a level sufficient to achieve the high image quality that is the objective of the present invention.

Furthermore, the crystallite diameter of the crystals to which the peak (Peak A) derived from the condensed polycyclic pigment belongs must be 5 nm or more and 20 nm or less. By specifying the crystallite diameter within a specific range, the condensed polycyclic pigment in the toner can absorb light efficiently and effectively, and the coloring power as well as the brightness and saturation can be increased.

This is believed to be due to the following reasons.
Even if a condensed polycyclic pigment has a specific crystal structure, if the crystallite diameter is large as in the past, when the pigment ratio present in the toner is kept constant, the ratio of crystal faces present in the pigment that absorb light of a desired wavelength and generate a color with high coloring power, saturation, and brightness at a desired hue angle decreases.

Therefore, as specified in the present invention, when a toner has a specific crystal structure and is finely divided to have a crystallite diameter of 20 nm or less, the number of crystal faces that absorb light of a desired wavelength and develop color at a desired hue angle increases relatively, resulting in a toner that efficiently increases coloring power, chroma, and brightness.
Furthermore, by making the crystallite diameter 5 nm or more, it is possible to prevent light from being transmitted through the pigment without being received by the crystal surfaces due to the crystallites being too small, and by maintaining efficient light absorption at the crystal surfaces, it is possible to increase the coloring power, saturation and brightness of the toner.

Furthermore, when the binder resin has an ester group, the crystallite size in the above range exerts an effect of preventing offset, and the mechanism thereof is considered to be as follows.
First, it is believed that the crystal faces of condensed polycyclic pigments are active surfaces onto which ester groups are easily adsorbed.
That is, when the ratio of pigment present in the toner is constant, the ratio of the pigment crystal planes present in the toner decreases as the crystallite diameter of the pigment increases. It is presumed that when ester groups are present in the binder resin of the toner, the ester groups adsorb to the crystal planes of the pigment, thereby exerting a filler effect and exerting an effect on offset resistance. Therefore, as specified in the present invention, by reducing the crystallite diameter and increasing the ratio of the crystal planes present in the toner, the adsorption sites of the ester groups to the crystallites increase, making it easier for the filler effect to occur. It is believed that this increases the viscosity of the toner during fixing in a copier or the like, thereby improving hot offset resistance.

The crystallite size of the crystals to which peak A belongs is preferably 10 nm or more and 16 nm or less for the reasons of further improving the efficiency of the light absorption of the toner and enhancing the coloring power.
In addition, by having the crystallite diameter in the above range, the number of adsorption sites of the ester groups to the crystallites increases, which makes it easier for the filler effect to be produced, which is believed to increase the viscosity of the toner and improve the hot offset resistance.
The method of the present invention for controlling the crystallite size to such a size will be described in detail in the description of the pigment kneading step and the toner kneading step described later.

<Pigments>
The condensed polycyclic pigments described above are a general term for a series of organic pigments having various chemical structures that have a condensed polycyclic aromatic ring structure consisting of a benzene ring or a heterocycle and that have good fastness properties such as weather resistance, heat resistance, and solvent resistance.
Examples of the pigments include quinacridone pigments, threne pigments, indigo pigments, perinone pigments, perylene pigments, phthalone pigments, dioxazine pigments, isoindolinone pigments, metal complex pigments, methine azomethine pigments, and diketopyrrolopyrrole pigments.
Among these, quinacridone pigments are particularly preferred as the condensed polycyclic pigment from the viewpoints of fine crystallites of the condensed polycyclic pigment, the effect of increasing coloring power, chroma and brightness which are thereby exhibited, and hot offset resistance.

The reasons for this are thought to be as follows.
That is, the quinacridone pigment easily interacts with the ester group contained in the binder resin, and the ester group is easily adsorbed to the crystal surface. This easily produces a filler effect and increases the viscosity of the toner. Therefore, the hot offset resistance is easily improved, and from this point of view, it is preferable that the condensed polycyclic pigment is a quinacridone pigment.

Furthermore, when the quinacridone pigment is contained in the kneaded product in the pigment kneading step described below, the viscosity of the kneaded product tends to increase due to the ease of interaction with the ester groups in the binder resin, and therefore the shear force during kneading tends to increase.
This makes it easier to make the crystallites of the condensed polycyclic pigment finer, and increases the number of crystal faces in the toner that absorb light of the desired wavelength and develop color at the desired hue angle, thereby improving saturation and brightness.

（式（１）中、Ｘ_１及びＸ_２は、それぞれ独立して、水素原子、塩素原子又はメチル基を示す。）
上記式（１）で表される化合物は、単独又は複数を組み合わせて用いることができる。
また、２種類以上のキナクリドン化合物の固溶体であってもよい。 The quinacridone pigment contains a compound represented by the following formula (1).

(In formula (1), _X1 and _X2 each independently represent a hydrogen atom, a chlorine atom, or a methyl group.)
The compounds represented by the above formula (1) can be used alone or in combination of two or more.
Also, it may be a solid solution of two or more kinds of quinacridone compounds.

The compound may also be treated with a rosin compound containing abietic acid or the like to facilitate dispersion in the binder resin.

Pigments that can be used together with condensed polycyclic pigments include known organic pigments and carbon black.

For example, cyan pigments include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

Examples of magenta pigments include condensed azo compounds (hereinafter simply referred to as "azo pigments"), diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

Yellow pigments include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

Black colorants include carbon black or those toned to black using the above-mentioned yellow pigments, magenta pigments, and cyan pigments.

The pigments may be used alone or in combination of two or more.
In particular, it is preferable to use a mixture of a condensed polycyclic pigment and an azo pigment. The preferable ratio of the pigments when mixed will be described later in the pigment kneading step.

The content of the pigment varies depending on the color, but is preferably from 1.0% by mass to 15.0% by mass based on the mass of the toner.
If the content exceeds 15.0% by weight, the pigments are likely to aggregate, which makes it difficult to absorb light and develop color efficiently, and the saturation and brightness are likely to be low. Therefore, the content is preferably 15.0% by weight or less.
On the other hand, if the content is less than 1.0% by mass, the coloring strength is unlikely to increase, so that the content is preferably 1.0% by mass or more.

It is further preferable that the pigment content is 3% by mass or more and 10% by mass or less based on the mass of the toner.

In particular, the magenta pigment may contain a pigment or dye other than the compound represented by formula (1) above.

For example, the following may be mentioned for magenta pigments:
C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; C.I. Pigment Violet 19; C.I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35. These may be used alone or in combination of two or more.

Examples of magenta dyes include the following:
C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C. I. Disperse Red 9; C. I. Solvent Violet 8, 13, 14, 21, 27; C. I. Disperse Violet 1, and other oil-soluble dyes; C. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; and C. I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28, and other basic dyes. These may be used alone or in combination.

<Inorganic fine particles>
The toner particles of the present invention preferably contain inorganic fine particles.
The inorganic fine particles may be any known inorganic salt, inorganic oxide, or mineral, and examples of the inorganic salt include carbonates such as calcium carbonate and magnesium carbonate, and sulfates such as barium sulfate. Examples of the inorganic oxide include silica, alumina, titania, and strontium titanate. Examples of the mineral include kaolin, clay, and talc.
Among the above, inorganic fine particles having an irregular shape are preferred as a grinding agent for the pigment in the production method described below.
Also, different types of inorganic fine particles can be used in combination.

The content of such inorganic fine particles in the toner particles is preferably 3.0% by mass or more and 40.0% by mass or less based on the mass of the toner particles for the following reasons.
By making the content 3.0% by mass or more, the coloring power is ensured, and by making the content 40.0% by mass or less, the inhibition of light absorption by the pigment due to the presence of inorganic fine particles in the toner particles can be suppressed, thereby making it possible to increase the coloring power while also increasing the brightness and saturation.

In addition, since it is preferable that inorganic fine particles do not affect the coloring power even when contained in toner particles, inorganic fine particles that are easily available and have a refractive index close to that of the toner binder resin are preferred.

Such inorganic fine particles are preferably at least one inorganic fine particle selected from the group consisting of calcium carbonate particles, barium sulfate particles, Mg ₃ Si ₄ O ₁₀ (OH) ₂ particles, and Al ₂ Si ₂ O ₅ (OH) ₄ particles.
The Mg ₃ Si ₄ O ₁₀ (OH) ₂ particles include talc particles.
Examples of the Al ₂ Si ₂ O ₅ (OH) ₄ particles include kaolin particles and clay particles.

The reason why the coloring power is maintained by using such inorganic fine particles is believed to be as follows.
That is, since the refractive _index of calcium carbonate particles, _{Al2Si2O5 (OH)4 particles, Mg3Si4O10 (OH)2 particles , and barium} sulfate particles is close to the refractive index of the binder resin compared to other inorganic fine particles, reflection at the interface between these inorganic fine particles and the binder resin is suppressed.
This allows the condensed polycyclic pigment to absorb light and develop color more efficiently than other inorganic fine particles.
Therefore, by containing inorganic fine particles selected from the group consisting of calcium carbonate particles _{, Al2Si2O5} ( _{OH)4 particles, Mg3Si4O10(OH)2 particles , and barium} sulfate particles in the toner particles, it is possible to increase the coloring power while also increasing the brightness _and saturation.

<Binder resin>
In the present invention, the binder resin must be a resin containing an ester group.
Examples of resins containing an ester group include amorphous polyesters, crystalline polyesters, styrene-acrylic acid ester copolymers, styrene-methacrylic acid ester copolymers, styrene-α-methyl chloromethacrylate copolymers, acrylic resins, and methacrylic resins.

In the present invention, the crystalline resin is a resin in which an endothermic peak is observed in differential scanning calorimetry (DSC).
Of these, it is preferable that the binder resin contains an amorphous polyester for the following reasons.
That is, since amorphous polyester has strong intermolecular forces and high internal cohesive forces, when the binder resin contains amorphous polyester, the viscosity of the toner tends to increase, which tends to increase the hot offset resistance, which is preferable.

In addition, it is preferable that the ester group concentration of the binder resin is 10.0% by mass or more and 30.0% by mass or less from the viewpoint of achieving both coloring power and hot offset resistance.

The ester group concentration herein refers to a value indicating the amount of ester group [—C(═O)O—] bonding sites contained in the binder resin in terms of mass %, and specifically, is a value represented by the following formula.
Ester group concentration (unit: %)=[(N×44)/number average molecular weight]×100
Here, N is the average number of ester groups per molecule in the binder resin, and 44 is the formula weight of the ester group [-C(=O)O-]. The number average molecular weight is the number average molecular weight of the binder resin.

From the viewpoint of achieving both coloring power and hot offset resistance, the ester group concentration is preferably from 10.0% by mass to 30.0% by mass for the following reasons.
That is, by having an ester group concentration of 10.0% by mass or more, more ester groups are adsorbed to the crystal faces of the crystallites in the condensed polycyclic pigment, which facilitates the production of a filler effect, thereby increasing the viscosity of the toner and improving the hot offset resistance.
In particular, when the condensed polycyclic pigment is a quinacridone pigment, it interacts more easily with the ester group and is more easily adsorbed to the quinacridone pigment, which promotes improvement in hot offset resistance.
On the other hand, by making the ester group concentration 30.0% by mass or less, an excessive increase in the viscosity of the toner is suppressed, which makes it possible to suppress the occurrence of light scattering due to the occurrence of unevenness on the image surface.
This can increase the coloring power.

Furthermore, the smaller the crystallite size, the stronger the effect of improving coloring power when the occurrence of unevenness on the image surface is suppressed.
That is, when the crystallite diameter is small, particularly when it is 16 nm or less, the crystallites tend to be uniformly dispersed within the image surface.
Therefore, when unevenness is suppressed, the crystal faces of the crystallites are uniformly dispersed within the image surface, which makes it easier for the crystals to absorb light more efficiently and more easily, thereby making it easier to express effective color development.
This synergistic effect can further increase coloring ability, saturation, and brightness.

Furthermore, by making the ester group concentration 10% by mass or more, the viscosity of the kneaded product during melt kneading in the pigment kneading step can be increased, and the efficiency of making the crystallites finer by the inorganic fine particles can be further improved.
That is, the ester group concentration is 10.0% by mass or more, so that the viscosity is increased, and the presence of inorganic fine particles in the kneaded product in which the shearing force is increased due to the increased viscosity, effectively reduces the crystallites.
From the viewpoints of hot offset resistance and coloring power, the ester group concentration is more preferably 15.0% by mass or more and 19.0% by mass or less.
Therefore, it is preferable to select the components constituting the amorphous polyester so that the ester group concentration falls within the above range.

Specific examples of components that constitute such an amorphous polyester structure include divalent or higher alcohol components, and carboxylic acid components such as divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters.

Examples of the dihydric or higher alcohol component include the following.
Alkylene oxide adducts of bisphenol A such as polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (2.0)-polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, and polyoxypropylene (6)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentane, etc. glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

On the other hand, examples of carboxylic acid components such as divalent or higher carboxylic acids, divalent or higher carboxylic anhydrides, and divalent or higher carboxylic esters include the following.
Aromatic dicarboxylic acids or their anhydrides, such as phthalic acid, isophthalic acid, and terephthalic acid; alkyl dicarboxylic acids or their anhydrides, such as succinic acid, adipic acid, sebacic acid, and azelaic acid; succinic acid or its anhydrides substituted with an alkyl or alkenyl group having from 6 to 18 carbon atoms; unsaturated dicarboxylic acids or their anhydrides, such as fumaric acid, maleic acid, and citraconic acid.
Among these, preferred examples include terephthalic acid, succinic acid, adipic acid, fumaric acid, trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, and anhydrides thereof.

The acid value of the amorphous polyester resin can be adjusted to the above range by adjusting the type and amount of monomers used in the amorphous polyester resin. Specifically, it can be controlled by adjusting the mixing ratio of the alcohol monomer and the acid monomer during resin production, or the molecular weight of the resin. It can also be adjusted by reacting a polyvalent carboxylic acid monomer (e.g., trimellitic acid or its anhydride) with the hydroxyl group present at the end of the condensation polymer after condensation polymerization of the alcohol component and the carboxylic acid component.

The binder resin may contain the known polymers or resins shown below within a range that satisfies the above-mentioned condition of the ester group concentration.
The following polymers or resins may be used alone or in combination of two or more.
Examples of the copolymer include homopolymers of styrene and its substitutes, such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-based copolymers, such as styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, and styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone-indene resin, and petroleum-based resin.

The binder resin preferably contains a crystalline polyester in an amount of 0.1% by mass or more and 5.0% by mass or less based on the mass of the binder resin for the following reasons.
That is, by including 0.1% by mass or more of the crystalline polyester in the binder resin based on the mass of the binder resin, the dissolution and spreading during fixing is promoted, and the dispersibility of the pigment contained in the toner during fixing is improved, so that even with a small pigment content, it is possible to increase the coloring power while also increasing the brightness and saturation.

Furthermore, the effect of increasing the coloring power, chroma and brightness increases as the crystallite size of the condensed polycyclic pigment decreases.
That is, when the melt spreading during fixing is promoted due to the fine crystallites, the crystal faces tend to be uniformly dispersed in the in-plane direction on the paper.
This allows for more efficient absorption of incident light by multiple crystal faces, resulting in more efficient color development, and therefore higher color strength as well as increased lightness and saturation in a synergistic manner.
This effect is enhanced when the crystallite size is 16 nm or less.

This effect is further enhanced when the inorganic fine particles are at least one inorganic fine particle selected from the group consisting of calcium carbonate particles, barium sulfate particles, Mg ₃ Si ₄ O ₁₀ (OH) ₂ particles, and Al ₂ Si ₂ O ₅ (OH) ₄ particles.
In other words, when the crystalline polyester is contained in an amount of 0.1% by mass or more based on the mass of the binder resin, the dissolving and spreading during fixing is promoted, the thickness of the toner layer on the paper becomes thinner, and therefore the influence of the optical properties of the inorganic fine particles becomes stronger.
In this case, if the inorganic fine particles are inorganic fine particles selected from the group, the difference in refractive index between the inorganic fine particles and the binder resin is small, so that the influence of the inorganic fine particles being present on the light path is reduced, and the coloring power, brightness, and saturation due to dissolution and spreading can be further increased.

On the other hand, crystalline polyester has high molecular mobility and therefore relatively high charge decay property, so that the content of crystalline polyester in the binder resin is preferably 5.0% by mass or less based on the mass of the binder resin in order to maintain the chargeability of the toner.
Due to this improved charge retention, good developability and transferability are maintained in the image forming process, so that coloring power can be maintained even with a small amount of pigment.

Such a crystalline polyester can be obtained, for example, by reacting a divalent or higher polyvalent carboxylic acid with a diol.
Among these, a condensation polymer of an aliphatic diol and an aliphatic dicarboxylic acid is preferred because it has a high degree of crystallinity.

The crystalline polyester may be used alone or in combination of two or more kinds.
The crystalline polyester is preferably a condensation polymer of an alcohol component containing at least one compound selected from the group consisting of aliphatic diols having from 2 to 22 carbon atoms and derivatives thereof, and a carboxylic acid component containing at least one compound selected from the group consisting of aliphatic dicarboxylic acids having from 2 to 22 carbon atoms and derivatives thereof.

Among them, from the viewpoint of hot offset resistance, it is more preferable that the crystalline polyester is a condensation polymer of an alcohol component containing at least one compound selected from the group consisting of aliphatic diols having 6 to 12 carbon atoms and their derivatives, and a carboxylic acid component containing at least one compound selected from the group consisting of aliphatic dicarboxylic acids having 6 to 12 carbon atoms and their derivatives.

The aliphatic diol having 2 to 22 carbon atoms (preferably having 6 to 12 carbon atoms) is not particularly limited, but is more preferably a chain (preferably linear) aliphatic diol from the viewpoint of hot offset resistance.
Examples include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-butadiene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.
Among these, preferred examples include straight-chain aliphatic α,ω-diols such as 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

The above derivatives are not particularly limited as long as they can be obtained by condensation polymerization with a similar resin structure. For example, derivatives obtained by esterifying diols can be mentioned.

In the alcohol component constituting the crystalline polyester, at least one compound selected from the group consisting of aliphatic diols having 2 to 22 carbon atoms (preferably 6 to 12 carbon atoms) and derivatives thereof is preferably 50 mass% or more, and more preferably 70 mass% or more, of the total alcohol components constituting the crystalline polyester.
Moreover, polyhydric alcohols other than the above aliphatic diols can also be used.

Among the polyhydric alcohols, examples of diols other than the above aliphatic diols include aromatic alcohols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A; 1,4-cyclohexanedimethanol, etc.

Among polyhydric alcohols, examples of trihydric or higher polyhydric alcohols include aromatic alcohols such as 1,3,5-trihydroxymethylbenzene; and aliphatic alcohols such as pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane.

Furthermore, monohydric alcohols may be used to the extent that they do not impair the properties of the crystalline polyester. Examples of monohydric alcohols include n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, 2-ethylhexanol, cyclohexanol, and benzyl alcohol.

On the other hand, the aliphatic dicarboxylic acid having 2 to 22 carbon atoms (preferably 6 to 12 carbon atoms) is not particularly limited, but may be a chain (preferably linear) aliphatic dicarboxylic acid.
Examples include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, glutaconic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, and itaconic acid.
Also included are those obtained by hydrolyzing these acid anhydrides or lower alkyl esters.

The derivatives are not particularly limited as long as they can be obtained by condensation polymerization with a similar resin structure. Examples include acid anhydrides of dicarboxylic acid components, and derivatives obtained by methyl esterification, ethyl esterification, or acid chloride of dicarboxylic acid components.

In the carboxylic acid components constituting the crystalline polyester, at least one compound selected from the group consisting of aliphatic dicarboxylic acids having 2 to 22 carbon atoms (preferably 6 to 12 carbon atoms) and their derivatives preferably accounts for 50% by mass or more, and more preferably 70% by mass or more, of the total carboxylic acid components constituting the crystalline polyester.

Polyvalent carboxylic acids other than the above aliphatic dicarboxylic acids can also be used. Among the polyvalent carboxylic acids, examples of divalent carboxylic acids other than the above aliphatic dicarboxylic acids include aromatic carboxylic acids such as isophthalic acid and terephthalic acid; aliphatic carboxylic acids such as n-dodecyl succinic acid and n-dodecenyl succinic acid; and alicyclic carboxylic acids such as cyclohexane dicarboxylic acid, as well as their acid anhydrides and lower alkyl esters.

In addition, among other polyvalent carboxylic acids, examples of trivalent or higher polyvalent carboxylic acids include aromatic carboxylic acids such as 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and pyromellitic acid, and aliphatic carboxylic acids such as 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, and 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, as well as derivatives such as their acid anhydrides and lower alkyl esters.

Furthermore, monovalent carboxylic acids may be used to the extent that they do not impair the properties of the crystalline polyester. Examples of monovalent carboxylic acids include benzoic acid, naphthalene carboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenyl carboxylic acid, acetic acid, propionic acid, butyric acid, and octanoic acid.

The crystalline polyester can be produced according to a conventional polyester synthesis method. For example, the carboxylic acid component and the alcohol component are subjected to an esterification reaction or an ester exchange reaction, and then the crystalline polyester can be obtained by carrying out a condensation polymerization reaction according to a conventional method under reduced pressure or by introducing nitrogen gas.

The esterification or transesterification reaction can be carried out, if necessary, using a conventional esterification or transesterification catalyst such as sulfuric acid, titanium butoxide, tin 2-ethylhexanoate, dibutyltin oxide, manganese acetate, and magnesium acetate.

The condensation polymerization reaction can be carried out using a conventional polymerization catalyst, such as titanium butoxide, tin 2-ethylhexanoate, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, and germanium dioxide. The polymerization temperature and the amount of catalyst are not particularly limited and may be determined appropriately.

In the esterification or transesterification reaction, or polycondensation reaction, in order to increase the strength of the resulting crystalline polyester, it is possible to use a method in which all the monomers are charged at once, or in order to reduce the amount of low molecular weight components, a divalent monomer is reacted first, and then a trivalent or higher monomer is added and reacted.

<Release Agent>
The toner particles may also contain a wax, if desired.
Specific examples include hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of hydrocarbon waxes such as oxidized polyethylene wax or block copolymers thereof; waxes containing fatty acid esters as the main component such as carnauba wax; and partially or completely deoxidized fatty acid esters such as deoxidized carnauba wax.

Further examples include: saturated straight-chain fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassidic acid, eleostearic acid, and parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; polyhydric alcohols such as sorbitol; esters of fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid with alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, and hexamethylene bisstearyl alcohol. Examples include saturated fatty acid bisamides such as arylamides; unsaturated fatty acid amides such as ethylene bisoleamide, hexamethylene bisoleamide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bisstearamide and N,N'-distearyl isophthalamide; fatty metal salts (commonly known as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; waxes grafted onto aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having hydroxyl groups obtained by hydrogenating vegetable oils and fats.

<Charge Control Agent>
The toner may also contain a charge control agent, if necessary.
As the charge control agent, known substances can be used, but particularly preferred are metal compounds of aromatic carboxylic acids which are colorless, can charge the toner quickly, and can stably maintain a constant charge amount.
Examples of negative charge control agents include metal salicylate compounds, metal naphthoate compounds, metal dicarboxylate compounds, polymeric compounds having sulfonic acid or carboxylic acid on the side chain, polymeric compounds having sulfonate or sulfonate ester on the side chain, polymeric compounds having carboxylate or carboxylate ester on the side chain, boron compounds, urea compounds, silicon compounds, and calixarenes.
The charge control agent may be added internally or externally to the toner particles.
The content of the charge control agent is preferably 0.2 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the binder resin.

<External Additives>
The toner may contain an external additive as necessary in order to improve fluidity and adjust the amount of triboelectric charge.
As the external additive, inorganic fine particles such as silica fine particles, titanium oxide fine particles, aluminum oxide fine particles, and strontium titanate fine particles are preferred. The inorganic fine particles are preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.
The specific surface area of the external additive is preferably 10 m ² /g or more and 50 m ² /g or less from the viewpoint of suppressing embedding of the external additive.
The content of the external additive is preferably 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
There is no particular limitation on the mixing of the toner particles and the external additive, and a known mixer such as a Henschel mixer can be used.

Next, the developer and the magnetic carrier will be described.
From the viewpoint of obtaining stable images over a long period of time, the toner is preferably mixed with a magnetic carrier and used as a two-component developer.
As the magnetic carrier, generally known ones can be used, such as metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earth elements, alloy particles thereof, or oxide particles thereof; magnetic materials such as ferrite; and magnetic material-dispersed resin carriers (so-called resin carriers) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state.

Next, a method for producing the toner will be described.
The toner may be produced by any one of the methods alone or in combination. For example, a shell may be formed on toner particles obtained by the kneading and pulverizing method or the dissolution and suspension method using the emulsion aggregation method.

<Kneading and grinding method>
In the kneading and pulverizing method, first, the constituent materials of the toner, that is, a pigment dispersion (described later), a binder resin, a release agent added as necessary, a colorant, and other additives are thoroughly mixed, and melt-kneaded using a known heat kneader such as a heated roll or a kneader (hereinafter, also referred to as a "melt kneader") (toner kneading step). Thereafter, the mixture is mechanically pulverized to a desired toner particle size (pulverizing step), classified to a desired particle size distribution (classifying step), and an external additive is added to the toner particles (external addition step) to produce a toner.
The pigment kneading step, which is a process for producing the pigment dispersion, will be described later.

(Toner kneading process)
The melt-kneading of the toner constituent materials can be carried out using a known heat kneading machine such as a heating roll, a kneader, etc. In the toner kneading step, it is preferable that the toner constituent materials are sufficiently mixed in advance using a mixer.

Examples of mixers include Henschel mixers (manufactured by Mitsui Mining Co., Ltd.); Super mixers (manufactured by Kawata Co., Ltd.); Ribocones (manufactured by Okawara Manufacturing Co., Ltd.); Nauta mixers, Turbulizers, and Cyclomixes (manufactured by Hosokawa Micron Corporation); Spiral Pin Mixers (manufactured by Pacific Machinery Co., Ltd.); and Lödige mixers (manufactured by Matsubo Co., Ltd.).

Examples of thermal kneaders include the KRC kneader (manufactured by Kurimoto Iron Works); the Buss-Co kneader (manufactured by Buss); the TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); the TEX twin-screw kneader (manufactured by Japan Steel Works); the PCM kneader (manufactured by Ikegai Iron Works); the Trimix, planetary mixer, three-roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho Co., Ltd.); the Kneadex (manufactured by Mitsui Mining Co., Ltd.); the MS-type pressure kneader, the Niderruder (manufactured by Moriyama Seisakusho Co., Ltd.); and the Banbury mixer (manufactured by Kobe Steel, Ltd.). The toner kneading process will be described in detail later.

(Crushing process)
The pulverization process is a process in which the toner kneaded product obtained in the above kneading process is cooled until it reaches a pulverizable hardness, and then coarsely pulverized with a pulverizer such as a crusher, hammer mill, feather mill, or pin mill.Then, the toner is mechanically pulverized to the toner particle size with a known pulverizer such as a collision plate jet mill, a fluidized bed jet mill, or a rotary mechanical mill.From the viewpoint of pulverization efficiency, it is desirable to use a fluidized bed jet mill as the pulverizer.

Examples of grinding machines include counter jet mills, micron jets, and innomizers (manufactured by Hosokawa Micron Corporation); IDS type mills and PJM jet grinders (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); cross jet mills (manufactured by Kurimoto Iron Works); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet-O-Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Kogyo Co., Ltd.); and Super Rotor (manufactured by Nisshin Engineering Co., Ltd.).

(Classification process)
The classification step is a step in which the finely pulverized product obtained in the above-mentioned pulverization step is classified to obtain toner particles having a desired particle size distribution.

Classifiers used for classification include known devices such as wind classifiers, inertial classifiers, and sieve classifiers. Specific examples include Classeal, Micron Classifier, and Spedic Classifier (manufactured by Seishin Enterprises); Turbo Classifier (manufactured by Nisshin Engineering); Micron Separator, Turbo Flex (ATP), and TSP Separator (manufactured by Hosokawa Micron Corporation); Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), Dispersion Separator (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); and YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.).

(External Addition Process)
After obtaining the toner particles, external additives such as inorganic fine particles such as silica, alumina, titania, and calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin are added as required to obtain a toner. They may be added by applying a shear force in a dry state. These inorganic fine particles and resin fine particles function as external additives such as a flowability aid and a cleaning aid.

As a mixing device for external addition, it is recommended to use a device that has a rotor with an agitating member and a main casing that is spaced apart from the agitating member.

Examples of mixing devices include Henschel mixers (manufactured by Mitsui Mining Co., Ltd.); Super mixers (manufactured by Kawata Co., Ltd.); Ribocones (manufactured by Okawara Manufacturing Co., Ltd.); Nauta mixers, Turbulizers, Cyclomixes (manufactured by Hosokawa Micron Co., Ltd.); Spiral Pin Mixers (manufactured by Pacific Machinery Co., Ltd.); Lödige mixers (manufactured by Matsubo Co., Ltd.), and Nobilta (manufactured by Hosokawa Micron Co., Ltd.). To uniformly mix the toner particles and external additives and to loosen the external additives, a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) is preferably used.

As mixing conditions for the external addition, the amount of external additive to be treated, the rotation speed of the stirring shaft, the stirring time, the shape of the stirring blade, the temperature inside the device, etc. may be appropriately selected to achieve the desired toner performance.
In addition, when coarse aggregates of additives are present in a free state in the obtained toner, a sieving machine or the like may be used as necessary.

<Dissolution suspension method>
The solution suspension method is a method in which a pigment dispersion, a resin component, and, if necessary, a release agent and the like are dissolved or dispersed in an organic solvent, the resulting solution or dispersion is dispersed in a poor solvent such as water to a size approximately equal to that of toner particles, and the organic solvent is distilled off in this state to produce toner particles.
In the solution suspension method, the toner is manufactured through a resin dissolving step, a granulating step, a solvent removing step, and a washing and drying step.
The pigment dispersion and the pigment kneading step, which is a process for producing the pigment dispersion, will be described later.

(Resin dissolving process)
The resin dissolving step is, for example, a step of preparing a resin composition by heating and dissolving a pigment dispersion and a styrene-acrylic acid copolymer as a binder resin in an organic solvent. If necessary, other resins, plasticizers, colorants, release agents, etc. may be dissolved or dispersed.
The organic solvent used may be any solvent that dissolves the binder resin in the pigment dispersion, and specific examples include toluene and xylene.
The amount of the organic solvent used is not limited, but may be an amount that provides a viscosity that allows the resin composition to be dispersed in an aqueous medium and granulated. Specifically, from the viewpoints of granulation properties and toner production efficiency, it is preferable that the mass ratio of the resin composition containing the pigment dispersion, the styrene-acrylic acid copolymer, and, if necessary, other resins, plasticizers, colorants, etc., to the organic solvent is 10/90 or more and 50/50 or less.
On the other hand, the pigment and grinding agent in the pigment dispersion, and the colorant and release agent added as necessary, do not need to be dissolved in an organic solvent and may be dispersed. When the colorant and release agent are used in a dispersed state, they are preferably dispersed using a dispersing machine such as a bead mill.

(Granulation process)
The granulation process is a process in which the obtained resin composition is dispersed in an aqueous medium using a dispersant to obtain a predetermined toner particle size, thereby preparing a dispersion (granulated material). The aqueous medium is mainly water. The aqueous medium preferably contains 1% by mass or more and 30% by mass or less of a monovalent metal salt. By containing the monovalent metal salt, the organic solvent in the resin composition is prevented from diffusing into the aqueous medium, and the particle size distribution of the toner is easily improved.
Examples of monovalent metal salts include sodium chloride, potassium chloride, lithium chloride, and potassium bromide, and among these, sodium chloride and potassium chloride are preferred.
The mixing ratio of the aqueous medium to the resin composition (aqueous medium/resin composition, mass ratio) is preferably 90/10 or more and 50/50 or less.

The dispersant is not particularly limited, but cationic, anionic and nonionic surfactants are used as organic dispersants, with anionic surfactants being preferred. Examples include sodium alkylbenzenesulfonate, sodium α-olefinsulfonate, sodium alkylsulfonate, sodium alkyldiphenyletherdisulfonate, etc. On the other hand, inorganic dispersants include tricalcium phosphate, hydroxyapatite, calcium carbonate, titanium oxide and silica powder.
Among these, the inorganic dispersant tricalcium phosphate is preferred because it has extremely little adverse effect on the granulation properties and stability thereof, and further on the properties of the toner obtained.

The amount of dispersant added is determined according to the particle size of the granulated material, and the particle size decreases as the amount of dispersant added increases. Therefore, the amount of dispersant added varies depending on the desired particle size, but it is preferably 0.1 to 15 parts by mass per 100 parts by mass of the resin composition. If it is 0.1 part by mass or more, coarse powder is less likely to be generated, and if it is 15% by mass or less, unnecessary fine particles are less likely to be generated.

In addition, when preparing a dispersion of the resin composition in an aqueous medium, it is preferable to carry out the preparation under high speed shearing. The dispersion of the resin composition dispersed in the aqueous medium is preferably granulated to a volume average particle size of 10 μm or less, more preferably 4 μm or more and 9 μm or less.
Devices for imparting high-speed shear include various high-speed dispersers and ultrasonic dispersers.
On the other hand, the volume average particle size of the dispersion can be measured by a particle size distribution analyzer (Coulter Multisizer III, manufactured by Coulter, Inc.) using the Coulter method.

(Solvent removal process)
The solvent removal step is a step of removing the organic solvent from the obtained dispersion. The organic solvent is preferably removed while stirring. If necessary, the removal rate of the organic solvent can be controlled by heating or reducing pressure.

(Washing and drying process)
After the solvent removal step, a washing and drying step may be carried out in which the toner particles are washed multiple times with water or the like, and then filtered and dried. When a dispersant that dissolves under acidic conditions, such as tricalcium phosphate, is used as the dispersant, it is preferable to wash with water after washing with hydrochloric acid or the like. By carrying out washing, the dispersant used for granulation can be removed, and the toner properties can be improved.
After washing, the toner particles can be obtained by filtering and drying. The obtained toner particles may be used as they are as a toner. Alternatively, similar to the external addition step of the kneading and pulverizing method, inorganic fine particles such as silica, alumina, titania, calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin may be added to the toner particles as necessary by applying a shear force in a dry state to obtain a toner. These inorganic fine particles and resin particles function as external additives such as a charging assistant, a flow assistant, and a cleaning assistant.

<Suspension Polymerization Method>
First, a pigment dispersion (described later) and other necessary components (e.g., a release agent, a crosslinking agent, a charge control agent, a chain transfer agent, a plasticizer, a pigment dispersant, a release agent dispersant) are dissolved or dispersed in a known polymerizable monomer to prepare a polymerizable monomer composition. In this case, a dispersing machine such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine can be used. Next, the polymerizable monomer composition is charged into an aqueous medium containing a dispersion stabilizer prepared in advance, and suspended using a high-speed dispersing machine such as a high-speed stirrer or an ultrasonic dispersing machine to perform granulation. The polymerization initiator may be mixed with other additives when preparing the polymerizable monomer composition, or may be mixed into the polymerizable monomer composition immediately before suspending it in the aqueous medium. In addition, the polymerization initiator may be added in a state dissolved in the polymerizable monomer or another solvent, as necessary, during or after granulation is completed, i.e., immediately before starting the polymerization reaction. Thereafter, the suspension is heated, and a polymerization reaction is carried out while stirring so that the droplet particles of the polymerizable monomer composition in the suspension maintain a particle state and do not float or settle, thereby forming toner particles. Thereafter, the suspension is cooled, washed as necessary, and dried and classified by various methods to obtain toner particles. The obtained toner particles may be used as they are as a toner. Alternatively, as in the external addition step of the kneading and pulverizing method, inorganic fine particles such as silica, alumina, titania, and calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin may be added to the toner particles as necessary by applying a shear force in a dry state to obtain a toner. These inorganic fine particles and resin particles function as external additives such as charging assistants, flow assistants, and cleaning assistants.

<Emulsion aggregation method>
The emulsion aggregation method is a manufacturing method in which a dispersion of fine resin particles that is sufficiently small relative to the target particle diameter is prepared in advance, and the fine resin particles are aggregated in an aqueous medium to produce toner particles.
In the emulsion aggregation method, a toner is produced through a process of preparing a resin fine particle dispersion, an aggregation process, a fusion process, a cooling process, and a washing process. A specific method for producing a toner using the emulsion aggregation method will be described below, but the method is not limited thereto.

(Step of Preparing Resin Particle Dispersion)
In the emulsion aggregation method, resin fine particles are first prepared. The resin fine particles can be produced by a known method, but are preferably produced by the following method.
For example, a polyester resin is dissolved in an organic solvent to form a uniform solution. Then, a basic compound and a surfactant are added as necessary. Furthermore, an aqueous medium is added to the solution to form fine particles. Then, the solvent is removed to obtain a resin fine particle dispersion in which the resin fine particles are dispersed.

More specifically, the polyester resin is dissolved in an organic solvent by heating, and a surfactant or base is added as necessary. Next, the aqueous medium is slowly added while applying shear using a homogenizer or the like, or the aqueous medium is added and then sheared using a homogenizer or the like to form resin microparticles. The solvent is then removed by heating or reducing pressure to produce a resin microparticle dispersion.

The concentration of the polyester resin when dissolved in the organic solvent is preferably 10% by mass or more and 50% by mass or less, more preferably 30% by mass or more and 50% by mass or less. Any organic solvent can be used as long as it can dissolve the polyester resin, but solvents that have high solubility for the polyester resin, such as toluene, xylene, and tetrahydrofuran, are preferred.

The surfactant is not particularly limited, and examples thereof include anionic surfactants such as sulfate salts, sulfonates, carboxylates, phosphates, and soaps, cationic surfactants such as amine salts and quaternary ammonium salts, and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols.
Examples of the base include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as triethylamine, trimethylamine, dimethylaminoethanol, diethylaminoethanol, etc. The base may be used alone or in combination of two or more kinds.

The volume-based median diameter of the resin microparticles is preferably 0.05 μm or more and 1.0 μm or less, and more preferably 0.1 μm or more and 0.6 μm or less. When the median diameter is within the above range, it becomes easier to obtain toner particles having the desired particle size. The volume-based median diameter can be measured using a dynamic light scattering particle size distribution meter (Nanotrac UPA-EX150: manufactured by Nikkiso).

The pigment dispersion may be mixed with a polyester resin to produce a fine particle dispersion consisting of the polyester resin and the pigment dispersion, or a fine particle dispersion (emulsion) consisting of the pigment dispersion alone may be produced. When producing a fine particle dispersion by mixing, the pigment dispersion is added when dissolving the polyester resin in an organic solvent in the resin fine particle dispersion preparation process, thereby producing a fine particle dispersion consisting of the polyester resin and the pigment dispersion. When producing a fine particle dispersion (emulsion) alone, the pigment dispersion, a surfactant, and an aqueous medium are mixed, and then the temperature is raised to a temperature at which the binder in the pigment dispersion melts, and shear is applied using a homogenizer or the like. The mixture is then cooled to produce a dispersion of the pigment dispersion in which the pigment dispersion is dispersed in the aqueous medium.

(Aggregation process)
The aggregation step is a step of preparing a mixed liquid by mixing a microparticle dispersion of a release agent, a microparticle dispersion of a charge control agent, etc., as necessary, with a microparticle dispersion consisting of a polyester resin and a pigment dispersion, or with a dispersion of a resin microparticle dispersion and a pigment dispersion. Then, the particles contained in the prepared mixed liquid are aggregated to form aggregate particles. Suitable examples of the method of forming aggregate particles include a method of adding and mixing an aggregating agent into the mixed liquid, raising the temperature, or appropriately applying mechanical power.

The release agent microparticle dispersion liquid used as necessary in the aggregation step is prepared by dispersing the release agent described above. The release agent microparticles are dispersed by a known method, for example, by mixing the release agent with an aqueous medium, heating the mixture to a temperature at which the release agent melts, shearing the mixture using a media-type dispersing machine such as a rotary shear type homogenizer, a ball mill, a sand mill, or an attritor, or a high-pressure counter-collision type dispersing machine, and then cooling the mixture to obtain a release agent dispersion liquid dispersed in the aqueous medium. In addition, a surfactant or polymer dispersing agent that imparts dispersion stability can be added as necessary.

Examples of flocculants used in the flocculation process include metal salts of monovalent metals such as sodium and potassium; metal salts of divalent metals such as calcium and magnesium; metal salts of trivalent metals such as iron and aluminum; and polyvalent metal salts such as polyaluminum chloride. From the viewpoint of particle size controllability in the flocculation process, divalent metal salts such as calcium chloride and magnesium sulfate are preferred.

It is preferable to add and mix the flocculant at a temperature between room temperature (25°C) and 75°C. When mixing is performed under these temperature conditions, flocculation proceeds in a stable state. Mixing can be performed using a known mixing device, homogenizer, mixer, etc.

The average particle size of the aggregate particles formed in the aggregation process is not particularly limited, but it is usually best to control the volume average particle size to 4.0 μm or more and 7.0 μm or less so that it is approximately the same as the average particle size of the toner particles to be obtained. This can be easily controlled, for example, by appropriately setting and changing the temperature when adding and mixing the aggregating agent and the like and the stirring and mixing conditions. The particle size distribution of the aggregate particles can be measured using a particle size distribution analyzer (Coulter Multisizer III: manufactured by Coulter) using the Coulter method.

(Fusion process)
The fusion step is a step of producing particles with smooth surfaces by heating the aggregate particles to a temperature equal to or higher than the glass transition temperature of the polyester resin to fuse them. Prior to the primary fusion step, a chelating agent, a pH adjuster, a surfactant, etc. may be appropriately added to prevent fusion between particles.

Examples of chelating agents include ethylenediaminetetraacetic acid (EDTA) and its alkali metal salts such as the Na salt, sodium gluconate, sodium tartrate, potassium and sodium citrate, nitrilotriacetate (NTA) salts, and many water-soluble polymers containing both COOH and OH functionality (polyelectrolytes).

The heating temperature should be equal to or higher than the glass transition temperature of the polyester resin contained in the aggregate, but lower than the temperature at which the polyester resin thermally decomposes. The heating/fusion time is shorter if the heating temperature is high, but longer if the heating temperature is low. In other words, the heating/fusion time depends on the heating temperature and cannot be generally determined, but is generally between 10 minutes and 10 hours.

(Cooling process)
The cooling step is a step of cooling the temperature of the aqueous medium containing the particles obtained in the fusion step to a temperature lower than the glass transition temperature of the polyester resin. By cooling to a temperature lower than the glass transition temperature, the generation of coarse particles can be suppressed. The specific cooling rate is 0.1° C./min or more and 50° C./min or less.

(Washing process)
The particles produced through the above process can be washed, filtered, and then repeatedly washed to remove impurities from the toner particles. Specifically, it is preferable to wash the toner particles using an aqueous solution containing a chelating agent such as ethylenediaminetetraacetic acid (EDTA) and its Na salt, and then wash the particles with ion-exchanged water. By repeatedly filtering the washed particles with ion-exchanged water multiple times, metal salts, surfactants, and the like can be removed from the toner particles. The number of filtrations is preferably 3 to 20 times from the viewpoint of production efficiency, and more preferably 3 to 10 times.

(Drying process)
The particles obtained in the above process are dried to obtain toner particles. The obtained toner particles may be used as they are as a toner. If necessary, an external additive may be added to obtain a toner, similar to the external addition process of the kneading and pulverizing method. Examples of the external additive include inorganic particles such as silica, alumina, titania, and calcium carbonate, and resin particles such as vinyl resin, polyester resin, and silicone resin. These can be added, for example, by applying a shear force in a dry state. These inorganic particles and resin particles function as external additives such as flowability aids and cleaning aids.

<Pigment kneading process and toner kneading process>
The method for producing the toner of the present invention is not particularly limited, but from the viewpoint of the coloring power and hot offset resistance of the toner, it is preferable that the method is a production method having a pigment kneading step and a toner kneading step as described in detail below.
That is, a pigment kneading step in which a mixture 1 containing a part of the binder resin, the condensed polycyclic pigment, the azo pigment, and inorganic fine particles is melt-kneaded in a twin-screw extruder to obtain a pigment dispersion;
a toner kneading step of melting and kneading a mixture 2 containing the pigment dispersion and the remaining binder resin to obtain a toner kneaded product;
It is preferable that the toner production method includes the steps of:
Here, a portion of the binder resin refers to the binder resin used when producing a pigment dispersion in the pigment kneading process, and the remaining binder resin refers to the binder resin newly used when producing a toner mixture in the toner kneading process.

The reason why the above-mentioned production method is preferred is that the crystallite diameter of the condensed polycyclic pigment can be made finer by carrying out a pigment kneading step in which a mixture 1 containing a part of the binder resin, the condensed polycyclic pigment, the azo pigment, and inorganic fine particles is melt-kneaded in a twin-screw extruder to obtain a pigment dispersion.
Then, a toner kneading step is carried out in which a mixture 2 of the pigment dispersion produced in the pigment kneading step and the remaining binder resin is melt-kneaded. As a result, a toner kneaded product containing crystallites of the condensed polycyclic pigment micronized in the pigment kneading step is produced, forming the basis of the toner physical properties according to the present invention.
Therefore, by pulverizing this toner kneaded product, it is possible to produce a toner having improved coloring power, saturation and brightness even with a small pigment content.

In particular, in the pigment kneading process, in the case of condensed polycyclic pigments, which have a peak at a diffraction angle 2θ of 5.65°±0.50°, and in particular in the case of quinacridone pigments, the inorganic fine particles can more efficiently reduce the size of the crystallites in the pigment.

The reasons for this are thought to be as follows.
That is, the condensed polycyclic pigment, especially the quinacridone pigment, having a peak at a diffraction angle 2θ of 5.65°±0.50° easily interacts with the ester group in the binder resin, and the ester group easily adsorbs to the pigment. Therefore, the viscosity of the molten kneaded material during the pigment kneading process is likely to increase, and the shear force in the kneading device is increased. When inorganic fine particles are present in the kneaded material with increased shear force, the inorganic fine particles, which have high hardness, exert a pressing effect on the pigment, thereby achieving fine crystallites. In this way, the inorganic fine particles can more effectively fine the crystallites of the condensed polycyclic pigment.
As a result, the number of crystal faces that absorb light of the desired wavelength and produce color at the desired hue angle is increased, thereby increasing coloring power, saturation, and brightness even when the pigment content in the toner is low.

The pigment kneading step and the toner kneading step will be described in detail below.
<Pigment kneading process>
As described above, the pigment kneading step is a step in which a pigment dispersion is prepared by uniformly mixing a pigment, inorganic fine particles as a grinding agent, and a portion of the binder resin contained in the toner, and then kneading the mixture.
For example, as the raw materials for the pigment dispersion, at least the pigment, inorganic fine particles, and binder resin are weighed in predetermined amounts, blended, and mixed to obtain a mixed raw material for the pigment dispersion (hereinafter, also simply referred to as "Mixture 1"). As the mixing device, a mixer similar to that described in the above-mentioned toner kneading process can be used.

Next, the mixed pigment dispersion raw material is charged into a melt kneader and melt-kneaded to uniformly disperse the pigment and inorganic fine particles, and the pigment is crushed by the inorganic fine particles in the shear field inside the melt kneader to obtain a pigment dispersion. In the present invention, the pigment dispersion refers to granular material having a size of several millimeters or less that has been coarsely crushed by the above-mentioned hammer mill or pin mill or the like.
In the pigment kneading step, the same device as that described above for the toner heat kneader can be used. In particular, it is preferable to use a twin-screw extruder, which can efficiently reduce the crystallite size of the condensed polycyclic pigment to 5 nm or more and 20 nm or less.
By reducing the crystallite size of the condensed polycyclic pigment in this manner, the coloring power, chroma, brightness and hot offset resistance of the toner can be improved.

Examples of twin-screw extruders (hereinafter also referred to as "twin-screw kneaders") include the KTK type twin-screw extruder (manufactured by Kobe Steel, Ltd.), the TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), the PCM twin-screw kneader (manufactured by Ikegai Iron Works), and the twin-screw extruder (manufactured by KCK Corporation).

The twin-screw extruder will now be described.
A twin-screw extruder is a kneading machine in which two melt-kneading shafts called paddles pass through a barrel, which is a heated cylinder that keeps the temperature constant.
An example of this is shown in Figure 1. The mixture 1 is supplied from one end of a melt-kneading shaft, and while being heated to a molten state, is kneaded by the rotation of the melt-kneading shaft and is extruded from the other end.
Vent holes may be installed midway for the main purpose of degassing. The cross section of the melt-kneading shaft is propeller-shaped or triangular, and is set out of phase with one end always rotating as if rubbing against the other. This structure has a self-cleaning effect that sends the kneaded material forward without adhering to the melt-kneading shaft or barrel wall.
In addition, by rotating the melt-kneading shafts in the same direction, an appropriate shear force can be applied.
This allows the pigment to be finer.
Therefore, it is preferable that the rotation directions of the two melt-kneading shafts are the same.
The melting part is the part of the melt-kneading shaft from the barrel (C1) next to the material supply port to the extrusion port. Usually, the barrel (C0) of the material supply port is not melted because the material needs to be inserted into the melt-kneading shaft. Therefore, it is not considered as the melting part in the setting of the kneading conditions.

It is preferable that the length of the melted portion of the melt-kneading shaft is 500 mm or more and 1500 mm or less.
When the length of the molten portion is within the above range, the molten residence time of the mixture is appropriate, so that sufficient kneading can be performed. In addition, excessive heat and shearing can be prevented from being applied to the kneaded product.
The melt-kneading shaft is roughly divided into two parts, one is the feed screw part and the other is the kneading part. The screw part has the function of sending the molten kneaded material forward while heating it. When the viscosity of the molten kneaded material inside the cylinder is high, the molten kneaded material is kneaded by the high shear force caused by friction between the wall of the screw part and the molten kneaded material. On the other hand, when the viscosity is low, the shear force tends to decrease and the molten kneaded material is not easily kneaded. Also, the kneading part has almost no effect of sending the molten kneaded material forward, and the kneaded material remains and fills the kneading part.

<Toner kneading process>
The toner kneading step, as described above, is a step in which the pigment dispersion produced in the pigment kneading step is kneaded with the remaining binder resin to produce a toner kneaded product.
In the toner kneading process, the pigment dispersion produced in the pigment kneading process, the remaining binder resin after use in the pigment kneading process, and other necessary additives such as a release agent and a charge control agent are weighed out in predetermined amounts, and then uniformly mixed to obtain a mixed toner raw material (hereinafter simply referred to as "mixture 2").
Next, the mixture 2 is put into a melt kneader and melt-kneaded to obtain a toner mixture.

In the pigment kneading step and the toner kneading step, a preferred specific method for reducing the crystallite size of the condensed polycyclic pigment, particularly for controlling and reducing the crystallite size to a range of 5 nm or more and 20 nm or less, is as follows.
That is,
In the pigment kneading step, a part of the binder resin, a condensed polycyclic pigment, an azo pigment, and inorganic fine particles are used as the pigments to be melt-kneaded, and assuming that the content of the part of the binder resin is Mr (mass%), the content of the condensed polycyclic pigment is Ma (mass%), the content of the azo pigment is Mb (mass%), and the content of the inorganic fine particles is Mi (mass%) based on the mass of mixture 1,
In the toner kneading step, the remaining binder resin is 30.0% by mass or more and 75.0% by mass or less based on the mass of the mixture 2, and
In the pigment kneading process, 30.0≦Mr≦75.0
0.20≦(Ma+Mb)/Mr≦1.40
0.17≦Mi/Mr≦1.30
It is preferable to satisfy the above in order to reduce the crystallite size of the condensed polycyclic pigment in the toner.

By satisfying such a numerical range, the crystallite diameter of the condensed polycyclic pigment can be made smaller than before, and the dispersibility of the condensed polycyclic pigment in the toner kneaded product can be improved, and at the same time, the dispersibility of the crystallites can be improved.
That is, by setting the content Mr of the binder resin used in the pigment kneading step to 30.0 mass % or more, the filler effect caused by the ester groups in the binder resin being adsorbed to the condensed polycyclic pigment is easily exhibited.
This increases the viscosity of mixture 1 during melt kneading, thereby increasing the shear force.

In this manner, with the shear force being increased, by containing in mixture 1 an inorganic fine particle content Mi of 0.17 or more as a ratio to the binder resin content Mr, the crushing force of the inorganic fine particles on the condensed polycyclic pigment is increased and the crystallite size of the condensed polycyclic pigment is made finer.

Furthermore, by having the sum (= Ma + Mb) of the condensed polycyclic pigment content Ma and the azo pigment content Mb contained in mixture 1 be 0.20 or more in ratio to the binder resin content Mr, the pigment itself exerts its effect as a grinding aid.
By satisfying these control conditions, it becomes easier to further refine the crystallite size of the condensed polycyclic pigment to 20 nm or less.

Furthermore, when a quinacridone pigment is used as the condensed polycyclic pigment, it is likely to interact with and adsorb the ester group, which makes it easier for the filler effect to be expressed and increases the shear force during melt kneading.
In addition, when the type of inorganic fine particles is at least one inorganic fine particle selected from the group consisting of calcium carbonate particles, barium sulfate particles, Mg ₃ Si ₄ O ₁₀ (OH) ₂ particles, and Al ₂ Si ₂ O ₅ (OH) ₄ particles, the crystallite size is easily reduced.
The combined effects of the different types of inorganic fine particles enhance the effect of reducing the crystallite diameter by satisfying the above-mentioned numerical conditions of Ma, Mb, Mi, and Mr. As a result, the crystallite diameter can be stably reduced to 20 nm or less, and more preferably to 16 nm or less.

On the other hand, in order to increase the coloring power while also increasing the brightness and chroma, the crystallite size is required to be 5 nm or more, more preferably 10 nm or more.
In order to make the crystallite size equal to or larger than the lower limit, it is preferable that the ratio of the content Mi of the inorganic fine particles to the content Mr of the binder resin in the mixture 1 in the pigment kneading step is 1.30 or less.
By not incorporating too many inorganic fine particles in this way, it becomes easier to control the crystallite size so that it does not become too fine.

In addition, by restricting the sum (= Ma + Mb) of the condensed polycyclic pigment content Ma and the azo pigment content Mb contained in mixture 1 to a ratio to the binder resin content Mr of 1.40 or less, the effect of the pigment itself as a grinding aid can be suppressed.
By satisfying these conditions, excessive miniaturization of the crystallites can be suppressed, and the crystallite diameter can be easily controlled to 5 nm or more.

Furthermore, by setting Mr to 75.0 mass % or less, stable operation of the kneading device in the pigment kneading step becomes possible, and stable control of the crystallite size as described above becomes possible.
In this way, by making it possible to stably reduce the crystallite size to an appropriate level, it is possible to increase the coloring power, chroma, and brightness even with a small pigment content as a toner.Furthermore, the viscosity of the toner is increased, and the hot offset resistance can be improved.

Furthermore, it is preferable that the remaining binder resin in the toner kneading process is 30.0% by mass or more and 75.0% by mass or less, based on the mass of mixture 2. In the toner kneading process, the crystallite size and pigment dispersion state obtained in the pigment kneading process are well maintained, and it is possible to finally obtain a toner having the fine crystallite size according to the present invention.

Furthermore, in the pigment kneading step, the content of the magenta pigment is more preferably as follows.
That is, Ma and Mb are
3.0≦Ma≦16.0
1.00≦Mb/Ma≦4.00
It is preferable to satisfy the above in terms of further improving the coloring power, brightness and chroma of the toner.
When Ma and Mb are within the above ranges, the effect of the pigment itself as a grinding aid for finely breaking down the crystallites of the condensed polycyclic pigment can be enhanced.
This allows the crystallite size of the condensed polycyclic pigment to be made fine, enabling the toner to absorb light efficiently, and thus enabling the coloring power to be increased even with a small pigment content, while also increasing the brightness and saturation.

In addition, the ester groups in the binder resin are more easily adsorbed to the pigment, which increases the toner viscosity and improves hot offset resistance.

In addition, by having the content of the condensed polycyclic pigment within the above range, the fine crystallites are more easily dispersed uniformly within the toner, which increases the coloring power while also increasing the brightness and saturation.

In addition, when the pigment content is within the above range and the _{inorganic fine particles are at least one inorganic fine particle selected from the group consisting of calcium carbonate particles, barium sulfate particles, Mg3Si4O10(OH)2 particles, and Al2Si2O5 ( OH ) 4 particles , the} crystallites are more easily dispersed uniformly in the toner.
That is, by using inorganic fine particles selected from the group, the crystallites can be made finer, and therefore the pigment content within the above range can be more effectively improved to facilitate uniform dispersion.
This promotes the adsorption of the ester group in the binder resin to the condensed polycyclic pigment, which tends to increase the viscosity of the toner and therefore tends to increase the hot offset resistance.
In addition, light can be absorbed more effectively, and color development with high saturation and brightness can be achieved.

Furthermore, when the pigment content is within the above range and the crystalline polyester in the binder resin is contained in an amount of 0.1 mass % or more based on the mass of the binder resin, the uniform dispersion of crystallites during fixing is dramatically improved.
That is, since the crystalline polyester has high molecular mobility, it enhances the dispersibility of the crystallites in the toner during fixing, and the pigment content within the above range has the effect of further enhancing the uniform dispersion of the crystallites during fixing.
As a result, in the fixed image, it is possible to increase the coloring power, brightness and saturation even with a small pigment content.

It is preferable to then subject the toner kneaded product obtained in the toner kneading step to the pulverizing step, classification step and external addition step in the kneading and pulverizing method described above to produce a toner, since this can keep production costs low.
In addition, the pigment dispersion produced in the pigment kneading step may be used to produce a toner by applying the dissolution suspension method, suspension polymerization method, or emulsion aggregation method as described above, and any of these methods may be used.

Hereinafter, methods for measuring various physical properties of the toner and raw materials will be described.
<Method of measuring the Bragg angle and crystallite size of peak A derived from condensed polycyclic pigment>
The Bragg angle of peak A originating from the condensed polycyclic pigment and the crystallite size are measured by X-ray diffraction measurement.
The X-ray diffraction measurement is performed using a measurement device "RINT-TTRII" (manufactured by Rigaku Corporation) and control software and analysis software that come with the device.
The measurement conditions are as follows.
X-ray: Cu/50kV/300mA
Goniometer: Rotor horizontal goniometer (TTR-2)
Attachment: Standard sample holder Divergence slit: Open Divergence vertical limit slit: 10.00 mm
Scattering slit: open Receiving slit: open Counter: scintillation counter Scanning mode: continuous Scanning speed: 4.0000°/min.
Sampling width: 0.0200°
Scan axis: 2θ/θ
Scanning range: 10.0000° to 40.0000°
Next, the toner is placed on the sample plate and the measurement is started.
For CuKα characteristic X-rays, the Bragg angle is θ, the diffraction angle is 2θ, and an X-ray diffraction spectrum is obtained with 2θ in the range of 3° to 35°, with the diffraction angle 2θ on the horizontal axis and the X-ray intensity on the vertical axis.
From this spectrum, the diffraction angle 2θ at which peak A originating from the condensed polycyclic pigment occurs can be determined.

When the full width at half maximum of this peak A is β, the Bragg angle is θ, λ is the X-ray wavelength, and K is a constant, the crystallite diameter D can be calculated from D = (K * λ) / (β * cos θ), where K is the shape factor and is set to 0.9.

<Method of measuring crystalline polyester content>
Add 160 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a sucrose concentrate. Add 31 g of the sucrose concentrate and 6 mL of Contaminon N (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, with a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.) to a centrifuge tube to prepare a dispersion. Add 1.0 g of toner to this dispersion, and break up the toner clumps with a spatula or the like. Next, shake the centrifuge tube with a shaker. After shaking, transfer the solution to a glass tube (50 mL) for a swing rotor and separate it in a centrifuge at 3500 rpm for 30 min.
This operation separates the toner particles from the removed external additives. It is visually confirmed that the toner particles and the aqueous solution are sufficiently separated, and the toner particles are collected and filtered with a vacuum filter, and then dried in a dryer for at least one hour to obtain toner particles from which the external additives have been separated.
The binder resin is dissolved from the toner particles from which the external additives have been separated by the above-mentioned method using a solvent such as tetrahydrofuran, and the resulting solution is filtered to obtain a filtrate 1 and a residue 1.
After drying the residue 1, the crystalline polyester is dissolved in a solvent such as heated methyl ethyl ketone, and filtered to obtain a filtrate 2 and a residue 2. The filtrate 2 is centrifuged, concentrated and dried to measure the content of the crystalline polyester.

<Method of measuring ester group concentration of binder resin>
The filtrate 1 is centrifuged, concentrated and dried to obtain a binder resin. In the present invention, the ester group concentration Er (mass%) of the binder resin is a weighted average of the ester group concentrations of the binder resin and the crystalline polyester, each of which is taken into account in the toner particles. A specific measurement method is as follows.
The soluble matter (filtrate 1) from the first separation is centrifuged, concentrated and dried to separate the binder resin. The ester group concentration Er1 (mass%) in the separated binder resin is measured by nuclear magnetic resonance spectroscopy (NMR).
The soluble portion (filtrate 2) of the second separation is centrifuged, concentrated and dried to separate the crystalline polyester. The ester group concentration Er2 (mass%) of the separated crystalline polyester is measured by nuclear magnetic resonance spectroscopy (NMR).
Furthermore, the ester group concentration Er (mass %) of the resin component is calculated using the following formula.
Er=(Er1×Mr1)/Mr+(Er2×Mr2)/Mrt
Here, Mr1 is the mass of the binder resin obtained from filtrate 1, Mr2 is the mass of the crystalline polyester obtained from filtrate 2, and Mrt is the sum of Mr1 and Mr2.

<Identification of inorganic fine particles and measurement of content>
The filter cake 2 is dispersed in THF, and the centrifugal force in the centrifugation method is changed to separate the inorganic fine particles and the colorant due to the difference in specific gravity. The inorganic fine particles are recovered from the liquid after the centrifugation, dried, and the content Mc of the inorganic fine particles is measured. The inorganic fine particles are identified using powder X-ray diffraction (XRD), infrared spectroscopy (IR), and X-ray fluorescence analysis (XRF).

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following formulations, parts and percentages are by weight unless otherwise specified.

<Production Example of Binder Resin 1>
Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane
A mixture of 50.0 parts of terephthalic acid, 25.0 parts of terephthalic acid and 23.5 parts of isophthalic acid was placed in a 4-liter, four-necked glass flask, which was then fitted with a thermometer, a stirring rod, a condenser and a nitrogen inlet tube and placed in a mantle heater.
Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was reacted for 4 hours at a temperature of 200° C. with stirring (first reaction step).
after that,
1.5 parts of trimellitic anhydride was added and reacted at 180° C. for 1 hour (second reaction step), to obtain binder resin 1, which is an amorphous polyester resin.

<Production Example of Binder Resin 2>
Styrene 92.0 parts n-Butyl acrylate 8.0 parts The above components were placed in a four-neck flask, the inside of the vessel was thoroughly replaced with nitrogen, and the temperature was raised to 130°C. Then, 200 parts of xylene was added dropwise with stirring over a period of 3 hours.
Further, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain Binder Resin 2.

<Production Example of Binder Resin 3>
Styrene 77.0 parts n-Butyl acrylate 23.0 parts The above components were placed in a four-neck flask, the inside of the vessel was thoroughly replaced with nitrogen, and the temperature was raised to 130°C. Then, 200 parts of xylene was added dropwise with stirring over a period of 3 hours.
Further, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain Binder Resin 3.

<Production Example of Binder Resin 4>
Styrene 100.0 parts The above components were placed in a four-neck flask, the inside of the vessel was thoroughly replaced with nitrogen, and the temperature was raised to 130° C., after which 200 parts of xylene was added dropwise with stirring over a period of 3 hours.
Further, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain Binder Resin 4.

<Production Example of Crystalline Polyester 1>
1,6-hexanediol 50.0 parts 1,10-dodecanedioic acid 50.0 parts The above materials were weighed into a flask equipped with a cooling tube, a stirrer, a nitrogen inlet tube, and a thermocouple.
Next, the atmosphere in the flask was replaced with nitrogen gas, and the temperature was gradually raised with stirring, and the mixture was reacted at 140° C. for 3 hours with stirring.
after that,
0.5 parts of tin 2-ethylhexanoate was added, the pressure inside the flask was reduced to 8.3 kPa, and the temperature was maintained at 200° C. while allowing the reaction to proceed for 4 hours.
Thereafter, the pressure inside the flask was reduced to 5 kPa or less, and the mixture was reacted at 200° C. for 3 hours, thereby obtaining crystalline polyester 1.

<Preparation of Pigment Dispersion 1>
Pigment type 1: Condensed polycyclic magenta pigment: Pigment. Red 122
13.7 parts by weight Pigment type 2: Soluble azo pigment: Pigment. Red 57:1
16.4 parts by weight Grinding agent: calcium carbonate 30.0 parts by weight Binder resin: binder resin 1 39.9 parts by weight The above materials were mixed in a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s ⁻¹ for a rotation time of 5 minutes to obtain mixture 1.
Thereafter, the mixture was kneaded using a twin-screw kneader (PCM-30 type, manufactured by Ikegai Corporation) as the kneader. The kneading temperature was set to 130° C. The obtained kneaded product was cooled and coarsely pulverized with a pin mill to a volume average particle size of 100 μm or less, to obtain a coarsely pulverized product of pigment dispersion 1.
The crystallite diameter of the condensed polycyclic pigment in the obtained pigment dispersion was 12.1 nm.

<Production of Pigment Dispersions 2 to 4, 6 to 8, 13 to 15, 24 to 27, 32 to 42, and 44>
Pigment dispersions 2 to 4, 6 to 8, 13 to 15, 24 to 27, 32 to 42, and 44 were produced in the same manner as in the production of Pigment Dispersion 1, except that the types and parts of Pigment Type 1, Pigment Type 2, Grinding Agent, and Binder Resin were changed to those shown in Table 1.
Here, pigment type 1 was all condensed polycyclic pigments, and pigment type 2 was an azo pigment.
The crystallite size of the condensed polycyclic pigment in the resulting pigment dispersion is shown in Table 1.
Table 1 also lists (Ma+Mb)/Mr, Mi/Mr, and Mb/Ma, where Mr is the content of the binder resin (mass%), Ma is the content of the condensed polycyclic pigment (mass%), Mb is the content of the azo pigment (mass%), and Mi is the content of the inorganic fine particles (mass%), all based on the mass of mixture 1.

<Preparation of Pigment Dispersion 5>
Pigment type 1: Condensed polycyclic magenta pigment: Pigment. Red 122
10.0 parts by weight Pigment type 2: Soluble azo pigment: Pigment. Red 57:1
12.0 parts by mass Grinding agent: calcium carbonate 27.5 parts by mass Binder resin: binder resin 1 50.5 parts by mass The above materials were mixed using a Henschel mixer (FM-75 type, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s-1 and a rotation time of 5 min to obtain mixture 1.
Thereafter, the mixture was kneaded using a planetary kneader (Trimix, manufactured by Inoue Seisakusho Co., Ltd.) as a kneader. The kneading temperature was set to 130° C. The obtained kneaded product was cooled and coarsely pulverized with a pin mill to a volume average particle size of 100 μm or less, to obtain a coarsely pulverized product of Pigment Dispersion 5.
The crystallite diameter of the condensed polycyclic pigment in the obtained pigment dispersion was 14.2 nm.

<Production of Pigment Dispersions 9 to 12, 16 to 23, 28 to 31, 43, 45, and 46>
Pigment dispersions 9 to 12, 156 to 23, 28 to 31, 43, 45, and 46 were produced in the same manner as in the production of Pigment Dispersion 5, except that the types and parts of Pigment Type 1, Pigment Type 2, Grinding Agent, and Binder Resin were changed to those shown in Table 1.

<Production Example of Toner 1>
Binder resin 1 65.6 parts by mass Pigment dispersion 1 26.6 parts by mass Synthetic wax i 5.0 parts by mass (hydrocarbon wax, maximum endothermic peak temperature 90° C.)
Crystalline polyester 1: 2.8 parts by mass (ratio of crystalline polyester to binder resin component: 3.7%)
The above materials were mixed using a Henschel mixer (FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s ^-1 for a rotation time of 5 min to obtain a mixture 2, which was then kneaded using a twin-screw kneader (PCM-30, manufactured by Ikegai Co., Ltd.). The obtained toner kneaded product was cooled and coarsely pulverized using a pin mill to obtain a coarsely pulverized product having a volume average particle size of 100 μm or less. The obtained coarsely pulverized product was finely pulverized using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.) by adjusting the rotation speed and the number of passes so as to obtain a target particle size. Further, classification was performed using a rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) to obtain toner particles. The rotation speed of the rotary classifier (200TSP, manufactured by Hosokawa Micron Corporation) was adjusted to obtain the target particle size and particle size distribution, and classification was performed. To 100 parts by mass of the obtained toner particles, 1.8 parts by mass of silica fine particles having a specific surface area of 200 m ² /g measured by the BET method and hydrophobized with silicone oil were added, and the mixture was mixed in a Henschel mixer (FM-75 type, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s ^-1 for a rotation time of 10 min to obtain Toner 1.

<Production Examples of Toners 2 to 46>
Toners 2 to 45 were produced in the same manner as in the production example of Toner 1, except that the type of binder resin, the type of pigment dispersion and the parts thereof, and the parts of the crystalline polyester were as shown in Table 2.
Additionally, the ester group concentration of the binder resin for each toner, the pigment concentration in the toner, the contents of various inorganic particles in the toner particles, and the content ratio of the crystalline polyester to the binder resin are shown in Table 2. Additionally, Table 2 shows the diffraction angle (2θ) of peak A derived from the condensed polycyclic pigment and the crystallite diameter of the condensed polycyclic pigment when X-ray diffraction measurement was performed on each toner.

<Production Example of Magnetic Core Particle 1>
Step 1 (weighing and mixing step):
・Fe ₂ O ₃ 62.7% by mass
・MnCO ₃ 29.5% by mass
・Mg(OH) ₂ 6.8% by mass
・SrCO ₃ 1.0% by mass
The ferrite raw materials were weighed so as to obtain the above composition ratio, and then pulverized and mixed for 5 hours in a dry vibration mill using stainless steel beads with a diameter of 1/8 inch.

Step 2 (pre-firing step):
The obtained pulverized material was made into pellets of about 1 mm square using a roller compactor. The pellets were passed through a vibrating sieve with 3 mm openings to remove coarse powder, and then through a vibrating sieve with 0.5 mm openings to remove fine powder. The pellets were then fired in a burner-type firing furnace at 1000° C. for 4 hours in a nitrogen atmosphere (oxygen concentration 0.01% by volume) to produce calcined ferrite. The composition of the resulting calcined ferrite was as follows:
(MnO) _a (MgO)b(SrO)c( _Fe2O3 )d
In the above formula, a=0.257, b=0.117, c=0.007, d=0.393

Step 3 (grinding step):
The obtained calcined ferrite was crushed to about 0.3 mm with a crusher, and then 30 parts of water was added to 100 parts of the calcined ferrite and the mixture was crushed in a wet ball mill using zirconia beads with a diameter of 1/8 inch for 1 hour. The obtained slurry was crushed in a wet ball mill using alumina beads with a diameter of 1/16 inch for 4 hours to obtain a ferrite slurry (finely crushed calcined ferrite).

・Process 4 (granulation process):
To the ferrite slurry, 1.0 part of ammonium polycarboxylate as a dispersant and 2.0 parts of polyvinyl alcohol as a binder were added per 100 parts of calcined ferrite, and the mixture was dried in a spray dryer (manufacturer: Okawara Kakoki) to form spherical particles. The resulting particles were granulated, and the particle size was adjusted, and then the particles were heated at 650° C. for 2 hours in a rotary kiln to remove the organic components of the dispersant and binder.

Step 5 (firing step):
In order to control the firing atmosphere, the material was heated from room temperature to 1300° C. in a nitrogen atmosphere (oxygen concentration 1.00% by volume) in an electric furnace over a period of 2 hours, and then fired at a temperature of 1150° C. for 4 hours. The temperature was then lowered to 60° C. over a period of 4 hours, and the material was returned from the nitrogen atmosphere to the air, and taken out at a temperature of 40° C. or less.

Step 6 (sorting step):
After the aggregated particles were crushed, low magnetic particles were removed by magnetic separation, and coarse particles were removed by sieving through a sieve with 250 μm openings, to obtain magnetic core particles 1 having a volume distribution-based 50% particle size (D50) of 37.0 μm.

<Preparation of Coating Resin 1>
Cyclohexyl methacrylate monomer 26.8% by mass
Methyl methacrylate monomer 0.2% by mass
Methyl methacrylate macromonomer 8.4% by mass
(Macromonomer having a weight average molecular weight of 5000 and a methacryloyl group at one end)
Toluene 31.3% by mass
Methyl ethyl ketone 31.3% by mass
Azobisisobutyronitrile 2.0% by mass
Among the above materials, cyclohexyl methacrylate monomer, methyl methacrylate monomer, methyl methacrylate macromonomer, toluene, and methyl ethyl ketone were placed in a four-necked separable flask equipped with a reflux condenser, a thermometer, a nitrogen inlet tube, and a stirrer, and nitrogen gas was introduced to create a sufficient nitrogen atmosphere. After that, the mixture was heated to 80°C, azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours to polymerize. Hexane was poured into the resulting reaction product to precipitate a copolymer, and the precipitate was filtered and then vacuum dried to obtain coating resin 1.
Next, 30 parts of coating resin 1 was dissolved in 40 parts of toluene and 30 parts of methyl ethyl ketone to obtain polymer solution 1 (solid content 30% by mass).

<Preparation of Coating Resin Solution 1>
・Polymer solution 1 (resin solid content concentration 30%) 33.3% by mass
Toluene 66.4% by mass
Carbon black Regal 330 (manufactured by Cabot) 0.3% by mass
(Primary particle size 25 nm, nitrogen adsorption specific surface area 94 m ² /g, DBP oil absorption 75 mL/100 g)
The mixture was dispersed for 1 hour using a paint shaker with zirconia beads having a diameter of 0.5 mm. The resulting dispersion was filtered through a 5.0 μm membrane filter to obtain a coating resin solution 1.

<Production Example of Magnetic Carrier 1>
(Resin coating process):
Magnetic core particles 1 and coating resin solution 1 were put into a vacuum degassing kneader maintained at room temperature (the amount of coating resin solution 1 put in was 2.5 parts as a resin component for 100 parts of magnetic core particles 1). After the put-in, the mixture was stirred at a rotation speed of 30 rpm for 15 minutes, and after a certain amount of the solvent (80 mass%) had evaporated, the mixture was heated to 80°C while mixing under reduced pressure, and toluene was distilled off over 2 hours, after which it was cooled. The obtained magnetic carrier was separated into low magnetic products by magnetic separation, passed through a sieve with an opening of 70 μm, and then classified with a wind classifier to obtain magnetic carrier 1 having a 50% particle size (D50) of 38.2 μm based on volume distribution.

<Production Example of Two-Component Developer 1>
92.0 parts of the magnetic carrier 1 and 8.0 parts of the toner 1 were mixed in a V-type mixer (V-20, manufactured by Seishin Enterprise Co., Ltd.) to obtain a two-component developer 1.

<Production Examples of Two-Component Developers 2 to 45>
As shown in Table 3, except that toner 1 was changed to toners 2 to 46, two-component developers 2 to 46 were obtained in the same manner as in the production example of two-component developer 1.

Example 1
Using the two-component developer 1, the toner 1 was evaluated for coloring power, brightness, chroma and hot offset resistance.

<Method for Evaluating Toner Tinting Strength>
As the image forming apparatus, a Canon full-color copying machine imageRUNNER ADVANCE C5255 was used, and a two-component developer was charged into the developing device of the magenta station to perform the evaluation.
The evaluation environment was normal temperature and humidity (23° C., 50% RH), and the evaluation paper used was plain copy paper CS-680 (A4 paper, basis weight: 68 g/m ² , sold by Canon Marketing Japan Inc.).
First, in the evaluation environment, an image was output with a constant developing bias, and the image density of the output image was examined.
The image density was measured using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite Corporation).
Based on the results of the X-Rite color reflection densitometer, the coloring power of the toner was evaluated according to the following criteria. The evaluation results are shown in Table 4.
(Evaluation Criteria)
A: 1.30 or more B: 1.25 or more and less than 1.30 C: 1.20 or more and less than 1.25 D: less than 1.20 In the present invention, C or more was determined to be an acceptable level.

<Method for Evaluating Toner Brightness and Saturation>
As the image forming apparatus, a Canon full-color copying machine imageRUNNER ADVANCE C5255 was used, and a two-component developer was charged into the developing device of the magenta station to perform the evaluation.
The evaluation environment was normal temperature and humidity (23° C., 50% RH), and the evaluation paper used was plain copy paper CS-680 (A4 paper, basis weight: 68 g/m ² , sold by Canon Marketing Japan Inc.).
First, in the evaluation environment, the amount of toner applied on the paper was changed to examine the relationship between the image density and the amount of toner applied on the paper.
Next, the image density of the FFH image (solid portion) was adjusted to 1.40, and a solid image was output.
The L1*, a1*, and b1* of the solid image were measured using a SpectroScan Transmission (manufactured by Gretag Macbeth) (measurement conditions: D50, viewing angle 2°).

The larger L1* is, the higher the lightness is, and the evaluation was performed according to the following criteria. The evaluation results are shown in Table 4.
(Evaluation Criteria)
A: 54.0 or more B: 52.0 or more but less than 54.0 C: 50.0 or more but less than 52.0 D: less than 50.0

In addition, C1* for each gradation was calculated using the following formula.
C1*={(a1*)2+(b1*)2}0.5
The higher the C1*, the higher the saturation, and the evaluation was performed according to the following criteria. The evaluation results are shown in Table 4.
(Evaluation Criteria)
A: 70.0 or more B: 65.0 or more but less than 70.0 C: 60.0 or more but less than 65.0 D: less than 60.0

<Hot offset resistance>
Paper: CS-680 (68.0g/m ² )
(Sold by Canon Marketing Japan Inc.)
Toner loading: 0.08 mg/ ^cm2
Evaluation image: A monochrome halftone image (2 cm x 2 cm) placed in the center of the A4 paper Fixing test environment: Normal temperature and low humidity environment: temperature 23°C / relative humidity 5% (hereinafter referred to as "N/L")
Process speed: 321 mm/sec
Fixing temperature: 200°C
After the unfixed image was produced, hot offset resistance was evaluated. The procedure was as follows: first, 10 blank postcards were passed through the center of the fixing belt, and then the unfixed image was passed through. The fog value was used as an evaluation index for hot offset. The average reflectance Dr (%) of the evaluation paper before image output and the reflectance Ds (%) of the white background after the fixing test were measured using a reflectometer (REFLECTOMETER MODEL TC-6DS manufactured by Tokyo Denshoku Co., Ltd.), and the fog was calculated using the following formula. The obtained fog was evaluated according to the following evaluation criteria.
Fog (%) = Dr (%) - Ds (%)
The results are shown in Table 4.
(Evaluation Criteria)
A: less than 0.2% B: 0.2% or more and less than 0.7% C: 0.7% or more and less than 1.1% D: 1.1% or more In the present invention, C or more was determined to be an acceptable level.

<Examples 2 to 43 and Comparative Examples 1 to 3>
The evaluation was carried out in the same manner as in Example 1, except that the toner and developer used were changed. The evaluation results are shown in Table 4.

Claims (10)

A toner having toner particles containing a binder resin having an ester group , a condensed polycyclic pigment , and inorganic fine particles ,
the inorganic fine particles are at least one inorganic fine particle selected from the group consisting of calcium carbonate particles, Al ₂ Si ₂ O ₅ (OH) ₄ particles, Mg ₃ Si ₄ O ₁₀ (OH) ₂ particles, and barium sulfate particles;
The condensed polycyclic pigment is C.I. Pigment Red 122, C.I. Pigment Red 202, or C.I. Pigment Violet 19;
When the toner was subjected to X-ray diffraction measurement using CuKα radiation, a peak A derived from the condensed polycyclic pigment was present at a position of 2θ=5.65°±0.50°, where θ is the Bragg angle,
The toner is characterized in that the crystallite diameter of the crystals to which the peak A belongs, calculated based on the peak A using the following formula, is 5 nm or more and 20 nm or less.
Crystallite size = (K × λ) / (β × cos θ)
[Wherein,
K (constant representing the shape factor) = 0.9
λ: X-ray wavelength
θ: Bragg angle
β: Full width at half maximum] 2. The toner of claim 1 , wherein the toner particles contain an azo pigment. 3. The toner according to claim 1 , wherein the inorganic fine particles are contained in an amount of 3.0% by mass to 40.0% by mass based on the mass of the toner particles. 4. The toner according to claim 1, wherein the crystallite diameter of the crystals to which the peak A belongs is 10 nm or more and 16 nm or less. 5. The toner according to claim 1, wherein the binder resin contains an amorphous polyester. 6. The toner according to claim 1, wherein the binder resin has an ester group concentration of 10.0% by mass or more and 30.0% by mass or less. 7. The toner according to claim 1, wherein the binder resin contains a crystalline polyester, and the content of the crystalline polyester is 0.1% by mass or more and 5.0% by mass or less based on the mass of the binder resin. A method for producing the toner according to any one of claims 1 to 7 ,
The production method includes a pigment kneading step of melt-kneading a mixture 1 containing a part of a binder resin, a condensed polycyclic pigment, an azo pigment, and inorganic fine particles in a twin-screw extruder to obtain a pigment dispersion;
a toner kneading step of melting and kneading a mixture 2 containing the pigment dispersion and the remaining binder resin to obtain a toner kneaded product;
A method for producing a toner having the formula: Based on the mass of the mixture 1, the content of the portion of the binder resin is Mr (mass%), the content of the condensed polycyclic pigment is Ma (mass%), the content of the azo pigment is Mb (mass%), and the content of the inorganic fine particles is Mi (mass%),
30.0≦Mr≦75.0
0.20≦(Ma+Mb)/Mr≦1.40
0.17≦Mi/Mr≦1.30
Fulfilling
The method for producing a toner according to claim 8 , wherein a content of the remaining binder resin added in step 2 is 30.0% by mass or more and 75.0% by mass or less based on a mass of the mixture 2 . The Ma and the Mb are
3.0≦Ma≦16.0
1.00≦Mb/Ma≦4.00
The method for producing a toner according to claim 9 , which satisfies the above condition.

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