JPH11184162A - Toner mother particles, toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the yellow toner mother particles, for developing an electrostatic charge image, capable of dispersing a pigment more minutely than the conventional flashing method, and attaining higher sharpness and sufficient color reproducibility and development at the time of forming a full color image by using a full color copying machine or printer or the like, and to provide the yellow toner and the yellow developer each using these yellow toner mother particles. SOLUTION: These yellow toner mother particles, for developing an electrostatic charge image, is obtained by mechanically kneading a mixture comprising at least 3 components of an epindoridione pigment (A) represented by the formula, and an aqueous inorganic salt (B), and a water-soluble solvent (C), and then, heat kneading an aqueous paste (D) of the processed pigment, obtained by rinsing and removing the components (B) and (C), with a resin solid at normal temperature, and further, heat kneading the resin-coated pigment freed of water, with a binder resin (G). In the formula, each of R1 -R8 is, independently, an H or halogen atom and at least 3 of R1 -R4 are halogen atoms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yellow toner base particle for developing an electrostatic image used for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like, and the yellow toner. The present invention relates to a yellow toner and a yellow developer formed using mother particles. More specifically, when an image is formed using magenta, cyan, and black toners and the like, a clear and sufficient color reproducibility, a yellow toner mother particle for electrostatic image development including a novel epidridione pigment capable of obtaining color development, and The present invention relates to a yellow toner and a yellow developer formed using the yellow toner base particles.

[0002]

2. Description of the Related Art In recent years, the development of full-color images in copying machines, printers, and the like has been rapidly progressing, and their practical use has been greatly increased. However, compared to photographs and printed matter, it is hard to say that a full-color electrophotographic image currently in practical use has reached a satisfactory image quality. In recent years, with the progress and development of computers, high-definition televisions, and the like, there is a strong demand for a method of forming a higher-definition full-color image. For this reason, there is a strong demand for further improving the quality of full-color electrophotographic images.

In electrophotography, an electrostatic latent image is generally developed using toner. The methods are roughly classified into a method using a two-component developer in which a small amount of toner is dispersed in a medium called a carrier, and a method using a one-component developer without using a carrier. For full color electrophotography,
A two-component developer in which a carrier and a toner are mixed and used is often used.

In color image formation by full-color electrophotography, all colors are reproduced by using three color toners of three primary colors, yellow, magenta and cyan, and preferably four color blacks for inking. Things.
In this method, for example, light from a document is first subjected to analog or digital color separation and guided to a photoconductive layer of a photoreceptor to form an electrostatic latent image of the first color. Subsequently, the toner is held on a transfer material such as paper through a development and transfer process. Further, for the second and subsequent colors, the above-described steps are sequentially performed a plurality of times, and the toners of a plurality of colors are superimposed on the same material to be transferred, and a final full-color image is obtained by one-time fixing.

The use of full-color copying machines, full-color printers, and the like to form full-color images on a transparent substrate such as a sheet for an overhead projector (hereinafter abbreviated as OHP) has been increasing. Today,
Toners used for full-color image formation are required to have various characteristics, for example, stable chargeability and good fluidity, as in the case of the most common conventional black toner,
Transparency, sharpness, color reproducibility and the like are further required.

[0006] Initially, pigments used in ordinary inks and paints have been used as they are as colorants for full-color toners used in full-color copying machines and full-color printers. However, a pigment having sufficiently satisfactory transparency and sharpness was not obtained. Unlike pigments used for toners, pigments used in ordinary inks and paints do not require much transparency and sharpness. There is also a strong demand in the market, and it has been necessary to newly form a pigment which is easy to obtain transparency and clearness when an image is formed, as a colorant for a full-color toner.

[0007] Among the organic pigments, a group of pigments called condensed polycyclics are also called high-grade pigments because of their excellent heat resistance, light resistance and solvent resistance, and various pigments have been used. Is being developed. Under these circumstances, representative pigments developed relatively early include anthraquinone and
Perylene, perinone and the like are known. Subsequently, dioxazine, quinacridone, isoindolinone, etc. were developed,
In recent years, quinophthalones, methine pigments, and the like have been developed.

[0008] Of these, isoindolinone and quinophthalone have been developed especially as yellow to orange pigments. Isoindolinone pigments are described in J. Chem. Soc.,
1941, as seen in the 625 there is a first report in 1941. After that, BP833,548, J.Paint Technol.Official D
igest, 37 , 1071, etc., it was used as a pigment in the 1960s. Especially because it is excellent in weather resistance, solvent resistance, heat resistance, resin, fiber coloring,
Widely used in paints and the like. Furthermore, in recent years, there has been a great demand as a substitute for heavy metal-based inorganic pigments. Quinophthalone is a bright yellow compound synthesized by the condensation of quinaldine with phthalic anhydride. Studies have been conducted on this compound to improve the pigment suitability, in particular, the light resistance and the solvent resistance. For example, it has been used as a pigment since the 1970s as shown in JP-B-47-3,476.

Other known condensed polycyclic pigments include pigments such as fluorbin and epindridione. Fluorubin is a compound synthesized for the first time in 1903 as shown in Ber., 36 , 4048. As a pigment, for example, it has excellent light resistance and solvent resistance as shown in JP-B-38-17,831. Also, as reported in Ann. Chem., 518 , 245, quinacridone first synthesized in 1935
As seen in P2,884,484 and USP2,884,485, in 1958 it became widely used as a new red pigment in the printing ink and paint industries. This led to a search for compounds with a structure similar to quinacridone. Epindridione was one of the compounds studied at that time. Epindridione is a structure lacking a central benzene ring in the chemical structure of quinacridone, which corresponds to a structural isomer of indigo. This compound is
M.Soc., are initially synthesized as a 1934, as reported in 1508 2,8 dimethyl substitution product, Helv. Chim. Acta, 3
As seen in 1,716, the maternal skeleton was first synthesized in 1948. The patent for this compound as a pigment is USP
3,334,102 only, in this patent dimethoxy, diethoxy substituted and di, tri, tetrahalogen substituted,
It is described as a pigment having excellent light fastness and coloring power.

Generally, the properties required for pigments include:
Coloring properties such as tinting strength, clarity, hue, light resistance, heat resistance, acid resistance, alkali resistance, solvent resistance, durability such as migration resistance and dispersibility, fluidity etc. Can be Of these required properties, the color properties and durability are properties that directly affect the quality of the pigment and are particularly important. Regarding the condensed polycyclic high-grade pigments described so far, in any of these properties, at present, excellent pigments are very limited,
The appearance of new pigments having excellent properties is expected.

That is, since a full-color image is obtained by superimposing a plurality of color toners on a material to be transferred as described above, if the light transmittance of each toner is insufficient, color reproducibility deteriorates. It is difficult to obtain a clear image. This phenomenon is remarkable especially when a full-color image is formed on a transparent substrate such as an OHP sheet, and it is difficult to obtain a good transparent image.

As a countermeasure, it is conceivable to increase the degree of dispersion of the pigment, that is, to reduce the pigment particle size in the toner. Generally, as the particle size of the pigment is reduced to increase the degree of dispersion, the transparency of the pigment dispersion is improved. However, ordinary dispersing machines such as a sand mill, a three-roll mill, a ball mill, and an extruder mainly break only secondary particles (primary particles are weakly agglomerated) of pigment into primary particles. And the like, it is difficult to make the pigment finer. By using a high-speed sand mill or the like, it is possible to further refine the pigment depending on the kind of the pigment, but it requires a very large amount of energy.

As means for refining the primary particles of the pigment,
There is known a method in which a pigment is dissolved in a strong acid such as concentrated sulfuric acid or polyphosphoric acid, and the solution is poured into cold water to precipitate the pigment as fine particles. In this method, the pigments that can be used are significantly limited in terms of solubility and stability of the pigment in strong acids.
In addition, since pigments finely divided by this method cause strong secondary aggregation when dried, it is very difficult to re-disperse the dried pigment to primary particles.Also, as a method for improving dispersibility, alcohol is used. However, it is known that heat treatment is performed in a solvent such as these, but undesired crystal growth occurs and the pigment particle size increases.

As another method, a method is known in which a pigment and a solid resin are heated and kneaded with a two-roll mill or a Banbury mixer while heating. However, since pigments generally grow at high temperatures, in the present method, the end point is reached when the mechanical crushing force and the crystal growth reach an equilibrium state, and there is a limit to the fineness of the pigment.

Further, as a method for finely dividing the primary particles of the pigment, a mixture of the pigment and a water-soluble inorganic salt such as salt is moistened with a small amount of a water-soluble solvent, kneaded strongly with a kneader or the like, and then mixed with the inorganic salt. There is a method in which the solvent is washed away with water and dried to obtain a pigment having fine primary particles. This method is generally known as a pigmentation method of β-type copper phthalocyanine in which crude copper phthalocyanine is mechanically ground in the presence of a water-soluble organic solvent by using salt as a grinding agent. In this case, the water-soluble organic solvent is used as a binder and to prevent the β-type crystal from being crystallized to the α-type crystal due to the mechanical shearing force of the kneader. In general, this method is called solvent salt milling, and is distinguished from a method of simply mechanically reducing the size without using a grinding agent (called dry milling). In a broad sense, salt milling without using a solvent is also called drying.

However, this method has a problem that the pigment tends to undergo strong secondary agglomeration during drying and the particle size of the pigment becomes large.

A resin or a resin solution is added to an aqueous slurry or an aqueous cake containing a pigment at a high concentration before the pigment is dried, and mixed and stirred to replace water around the pigment with the resin or the resin solution. The method of removing water and solvent is generally called flushing. In this method, since there is no step of drying the pigment, the aggregation of the pigment hardly occurs, and the pigment particles can be coated with the resin in a fine state. Can be

As the formation of full-color images using color toners has become common, the quality desired by users has improved, and the quality of electrophotography has been required to be as high as that of ordinary silver halide photographs. . Therefore, the dispersion of the pigment in the toner is improved even more than in the case where the conventional flushing treatment pigment is used, the light transmittance at the time of forming an image is improved, and the toner of multiple colors is superimposed on the same transfer material. When a full color image is formed
To obtain color reproducibility closer to the original. The dispersion of the pigment in the toner is further improved so that the pigment is sufficiently colored and a good image with a high density can be obtained.

When a full-color image is formed on a transparent substrate such as an OHP sheet, the sharpness and transparency of the image are improved. Is required.

[0020]

According to the present invention, when a full-color image is formed using a full-color copying machine or a printer, the pigment is more finely dispersed than the conventional flushing method. It is an object of the present invention to provide a yellow toner base particle for developing an electrostatic image capable of obtaining color reproducibility and color developability, and a yellow toner and a yellow developer using the yellow toner base particle.

[0021]

According to the present invention, at least three components of an organic pigment (A) represented by the following general formula (1), a water-soluble inorganic salt (B), and a water-soluble solvent (C) are provided. After mechanically kneading the mixture consisting of (A) and (B) and (C), the aqueous paste (D) of the treated pigment obtained by washing with water and the resin (E) which is a solid at room temperature are heated and kneaded.
Yellow toner mother particles for electrostatic image development, which are obtained by heating and kneading a resin-coated pigment (F) obtained by removing water and a binder resin (G).

General formula (1)

[0023]

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In the formula, R _{1 to} R ₈ each independently represent a hydrogen atom or a halogen atom, and at least three of R _{1 to} R ₄ are halogen atoms.

The second invention relates to at least three of the organic pigment (A), the water-soluble inorganic salt (B) and the water-soluble solvent (C) represented by the general formula (1) in the first invention. The mixture comprising the components is kneaded mechanically, and then the aqueous paste (D) of the treated pigment obtained by washing and removing (B) and (C) and the resin (E) which is a solid at room temperature are heated and kneaded.
Yellow toner mother particles for electrostatic image development, which are obtained by heating and kneading a resin-coated pigment (F) obtained by removing water and a binder resin (G). However, in the formula, R
_{1 to} R ₈ each independently represent a hydrogen atom, a fluorine atom or a chlorine atom, and at least three of R _{1 to} R ₄ are a fluorine atom or a chlorine atom.

According to a third aspect of the present invention, at least three of the organic pigment (A), the water-soluble inorganic salt (B), and the water-soluble solvent (C) represented by the general formula (1) in the first invention are provided. The mixture comprising the components is kneaded mechanically, and then the aqueous paste (D) of the treated pigment obtained by washing and removing (B) and (C) and the resin (E) which is a solid at room temperature are heated and kneaded.
Yellow toner mother particles for electrostatic image development, which are obtained by heating and kneading a resin-coated pigment (F) obtained by removing water and a binder resin (G). However, in the formula, R
₁ and R ₅ , R ₂ and R ₆ , R ₃ and R ₇ , R ₄ and R ₈ are respectively equal. R _{1 to} R ₄ each independently represent a hydrogen atom, a fluorine atom or a chlorine atom;
The individual is a fluorine atom or a chlorine atom.

The fourth invention is characterized in that the water-soluble inorganic salt (B) is used 2 to 20 times in weight ratio to the water-soluble solvent (C). The yellow toner mother particles for electrostatic image development according to any one of the above.

According to a fifth aspect of the present invention, there is provided a method for developing an electrostatic image, comprising mixing the yellow toner base particles for developing an electrostatic image according to any one of the first to fourth aspects and an external additive. Yellow toner.

According to a sixth aspect of the present invention, there is provided a yellow developer comprising a mixture of the yellow toner for developing an electrostatic image according to the fifth aspect of the invention and a carrier.

Examples of the compound represented by the general formula (1) are shown in Table 1 below as exemplary compounds.

[0031]

[Table 1]

[0032]

[0033]

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, an epindridione pigment has the property of being extremely insoluble in organic solvents. In J. Org. Chem., 33 , 4004 (1968), this property is due to strong intermolecular hydrogen bonding between the oxygen of the carbonyl group in the molecular structure and the hydrogen atom of the imide group in other molecular structures. It has been reported that this intermolecular hydrogen bond is more remarkably observed in the solid state than in the solution state. In the case of indigo, it is known that, due to intermolecular hydrogen bonding, the solid state transitions to a longer wavelength than the spectrum in a solution. Observation results in the case of the epidridione pigment are similar to the results in the case of the indigo, so that the existence of a similar intermolecular hydrogen bond is presumed.

The feature of the chemical structure of the epindridione pigment used in the present invention is that the benzene ring constituting the molecule has at least three halogen atoms. Such introduction of a halogen atom causes a change in the intermolecular force of the epidridione pigment, and as a result, it is possible to obtain a pigment having well-balanced properties in terms of color and various properties.

The method for producing the epindridione pigment used in the present invention differs depending on whether the chemical structure of the pigment is symmetric or asymmetric. In the case of a symmetrical chemical structure, it can be produced from a four-stage process of esterification of dihydroxyfumaric acid, dehydration condensation with a halogenated aniline, followed by a two-stage condensed cyclization process. In the case of an asymmetric chemical structure, it can be manufactured by the following method. First, an oxalacetic acid diester substituted with a halogenated phenylamino group is synthesized from an ester of glycine substituted with a nitrogen atom with a halogenated phenyl group and an oxalic acid diester. Next, by reacting with a halogenated aniline, a mixture of maleic acid and fumaric acid diester in which adjacent carbon atoms are substituted with different halogenated phenylamino groups is synthesized. As in the case of the symmetric structure described above, this mixture can be subjected to a two-stage condensed cyclization step to produce an epindridione pigment.

The epidridione pigment used in the present invention has a characteristic of easily obtaining transparency and clearness when used as a colorant for a toner for developing a full-color electrostatic charge image. Further, in the present invention, by carrying out the solvent salt milling of such an epindrizione pigment, it is possible to obtain an image which is more transparent and excellent in clarity than ever before. For example,
The organic pigment (A) and the water-soluble inorganic salt (B) are used as crushing aids, and the water-soluble solvent (C) is added in a small amount as a wetting agent. It shall be smaller than before. Thereafter, the mixture is poured into water and stirred with a high-speed mixer or the like to form a slurry. Next, the slurry is repeatedly filtered and washed with water to remove the water-soluble inorganic salt (B) and the water-soluble solvent (C), thereby obtaining an aqueous paste (D) of the treated pigment.

In the present invention, examples of the water-soluble inorganic salt (B) used for mechanical kneading include salt, potassium chloride, and glass nitrate, but are not limited thereto. Absent. The water-soluble inorganic salt is preferably used in a weight ratio of 1 to 20 times with respect to the pigment composition (A), and 3 to 1 times.
It is most preferable to use 0 times.

The water-soluble solvent (C) used in the present invention is not particularly limited.
From the viewpoint of safety, a solvent having a high boiling point is preferable because the solvent is easily evaporated. The water-soluble solvent (C) is preferably used in a weight ratio of 0.1 to 10 times, more preferably 0.5 to 5 times the weight of the pigment composition (A).

Examples of the water-soluble solvent (C) include 2-
(Methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2-
(Hexyloxy) ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol,
Examples thereof include 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and low molecular weight polypropylene glycol.

In the present invention, a resin may be added if necessary during mechanical kneading. The type of resin used is not particularly limited, and natural resins, modified natural resins, synthetic resins, synthetic resins modified with natural resins, and the like can be used. The resin used is preferably solid at room temperature, water-insoluble, and when using a solvent during kneading,
More preferably, it is partially soluble in the solvent. Furthermore,
A pigment derivative and a dispersant may be added.

The particle diameter of the pigment at the end of the salt milling is preferably 0.2 μm or less, more preferably 0.1 μm, based on the average particle diameter determined by a laser scattering method.
When the particles have such a particle size, a clear and sufficient color reproducibility and coloring property are easily obtained when an image is formed.

In the present invention, the above salt milling is performed,
It is important to obtain an aqueous paste (D) of a finely treated pigment, and then to flush the pigment without drying. By heating and kneading the aqueous paste (D) of the treated pigment with a resin (E) at room temperature, a resin-coated pigment (F) obtained by coating the treated pigment with the resin (E) at room temperature, a so-called flushing pigment is obtained. By using such a flushing pigment as a colorant for the yellow toner base particles, it is possible to obtain an image having much more excellent clarity and transparency than before.

The resin-coated pigment (F) in the present invention can be obtained, for example, as follows. The aqueous paste (D) of the treated pigment is transferred to a mixing and dispersing machine such as a kneader or a supermixer, and the room temperature solid resin (E) and other various additives as necessary are added and mixed and stirred. At this time, heating may be performed if necessary. About 10 minutes ~
In 20 minutes, the pigment content is transferred to the resin. The separated water is removed by decantation, and the remaining kneaded material is removed with water using two or three rolls as necessary to obtain a resin-coated pigment (F) (a pigment-rich chip). Good.

The resin (E) which is a solid at room temperature, that is, a resin that can be used for flushing, can be widely used, including known resins. In consideration of image transparency, a colorless and transparent resin is more preferable. For example, all known resins such as styrene-acrylic and polyester resins such as acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, and mixtures thereof can be used. In addition, polyethylene, polypropylene, polystyrene, styrene-butadiene copolymer, chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic resin, phenol resin, rosin-modified phenol resin, epoxy resin, ionomer resin, polyurethane resin, Silicone resin, rosin / ester, rosin and the like can be mentioned. The production method of any resin is not particularly limited.

The yellow toner base particles of the present invention can be obtained according to a conventional method. That is, the binder resin (G) and, if necessary, other charge control agents and additives are added to the resin-coated pigment (F) and premixed by a Henschel mixer or the like. Then dilute with an extruder, etc.
Perform melt kneading. Next, after cooling, it is coarsely pulverized by a hammer mill or the like and finely pulverized by a jet mill or the like. Thereafter, the particles are classified by an air classifier or the like to obtain a classified product having a predetermined particle size distribution with an average particle size of about 5 to 20 μm, that is, yellow toner base particles.

The binder resin (G), that is, a resin that can be used for melt-kneading after flushing, can be widely used, including known resins. In consideration of image transparency, a colorless and transparent resin is more preferable. The same type of resin as the resin (E) can be used, but the binder resin (G) does not necessarily need to match the resin (E).

It is also preferable to add a charge control agent to the yellow toner base particles of the present invention. As charge control agents,
All known types of positive and negative charges can be used, but a colorless or light-colored charge control agent that does not affect the color tone of an image is preferable. For example, an organic metal complex such as a metal complex of an alkyl-substituted salicylic acid (for example, a chromium complex, an aluminum complex, or a zinc complex of di-tert-butylsalicylic acid) can be given.

It is also preferred that the yellow toner base particles of the present invention contain an external additive as a fluidity improver and a cleaning aid. Any known external additives can be used. For example, 0.01 to 0.5 μm silica, alumina, metal oxides such as titanium oxide, silicon carbide, abrasives such as tungsten carbide, zinc stearate, lubricants such as fatty acid metal salts such as aluminum stearate, etc. 50
μm polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, polystyrene,
It is preferable to add a fine powder such as silicone. It is also preferable to add an external additive obtained by variously surface-treating these mixtures and further, these fine powders.

The yellow developer of the present invention is obtained by mixing the above-described yellow toner and carrier, and can be obtained by a conventionally known method, and is not particularly limited. As the carrier used for the yellow developer according to the present invention, all known carriers can be used. In general, carriers constituting a two-component developer are roughly classified into conductive carriers and insulating carriers. Normally, oxidized or unoxidized iron powder is used as the conductive carrier.
A typical example of the insulating carrier is a carrier in which the surface of a carrier core material particle generally made of a ferromagnetic material is uniformly coated with an insulating resin. Carrier as core material,
For example, particles of iron oxide (magnetite), reduced iron, copper, ferrite, nickel, cobalt, and the like, and alloys of zinc, aluminum, and the like can be used. As the coating resin, any of known materials such as acrylic resin, epoxy resin, silicone resin, urethane resin, polyacetal resin, polyamide resin, polycarbonate resin, phenol resin, vinyl acetate resin, cellulose resin, polyolefin resin, fluorine resin, amino resin, etc. It may be. The carrier preferably has a particle size of about 20 to 200 μm. Generally, the developer contains 1 to 1 toner.
It is preferable to contain 30%.

[0051]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. However, this does not limit the embodiment of the present invention at all. In Examples and Comparative Examples, parts and% indicate parts by weight and% by weight, respectively.

Example 1 [Synthesis Step of Epindridione Pigment] 44.4 parts of dihydroxyfumaric acid was dissolved in 190 parts of methanol, and 60 parts of anhydrous magnesium sulfate was added to this solution. The suspension is cooled to 0-5 ° C. and hydrogen chloride is bubbled in at this temperature for 4.5 hours with stirring. Next, this liquid is allowed to stand at room temperature for 3 days, and then the precipitated crystals are filtered. The crystals obtained are washed with a small amount of methanol, suspended in 600 parts of cold water and then quickly filtered. Further, the crystals were washed with cold water until the washing liquid became neutral, and dried at 70 ° C. to obtain 45.3 parts of an ester having the following structure.

[0053]

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Next, after suspending 44.0 parts of the above ester in 158 parts of methanol, 2,3,4-
80.9 parts of trifluoroaniline and 3 parts of concentrated hydrochloric acid are added, and the mixture is heated under reflux for 6 hours. During the heating, the reaction solution once becomes a solution, and then pale yellow crystals precipitate. After the reaction solution was cooled to 5 to 10 ° C., the precipitated crystals were filtered and dried at 70 ° C. to obtain 94.7 parts of a compound having the following structure.

[0055]

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86.8 parts of the above compound was added to Dowtherm A868
The suspension added in the solution was heated to 120 to 130 ° C. to form a solution, and the solution was heated under reflux to Dowtherm A347.
Add to parts over 30 minutes. Then, reflux heating was performed for 1 while removing the mixture of Dowtherm A and the generated methanol.
Perform for 5 minutes and cool to room temperature. The precipitated crystals were washed with petroleum ether and dried at 70 ° C. to obtain 61.9 parts of a compound having the following structure.

[0057]

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60.3 parts of the above compound are added to 603 parts of polyphosphoric acid with stirring. The mixture is added for 15 hours in one hour.
After heating to 0 ° C, it is heated at 145 to 150 ° C for 2 hours and then cooled to 40 to 50 ° C. Next, 1340 parts of methanol are gradually added while maintaining 40 to 50 ° C. After the addition is completed, the mixture is heated under reflux for 90 minutes and filtered. The solution was washed with water until the washing solution became neutral, and dried to obtain 50.0 parts of a pigment represented by Compound No. 1 in Table 1.

[Salt milling step] The above pigment: 250
Parts, 2500 parts of sodium chloride and 160 parts of polyethylene glycol 300 (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded for 3 hours. Next, this mixture was poured into 2.5 liters of warm water and stirred for about 1 hour with a high speed mixer while heating to about 80 ° C. to form a slurry. Thereafter, filtration and washing were repeated five times to remove sodium chloride and the solvent, thereby obtaining an aqueous paste having a solid content of 50%.

[Flushing step] The above aqueous paste 100.0 parts Unsaturated polyester resin: resin at room temperature solid (E) 25.0 parts Methanol 0.5 part About 30 parts while heating the above raw materials to 100 ° C. with a kneader.
Mix for a minute and transfer (flushing) the pigment to the resin,
Disperse uniformly in resin. After removing the separated water and solvent from the kneader, the remaining kneaded material was passed five times with a heating-type two roll to obtain a high-concentration pigment chip, that is, a resin-coated pigment.

[Toner Forming Step] Unsaturated polyester resin: binder resin (G) 100.0 parts High-concentration pigment chip 5.0 parts Negative charge control agent 4.0 parts Next, the above raw materials are extruded by an extruder. Melt and knead. After cooling, the mixture was roughly pulverized using a hammer mill and then finely pulverized using a jet mill.
0.0 μm toner base particles are obtained. The toner base particles 1
0.4 parts of titanium oxide fine powder is added to 00.0 parts and mixed with a Henschel mixer to obtain a toner.

[Toner Evaluation Step] 6 parts of the obtained toner was added to 100 parts of ferrite, and mixed with a ball mill to obtain a developer. Using this developer, an image was formed with a commercially available full-color copying machine (CLC350, manufactured by Canon) and evaluated.

Example 2 [Synthesis Step of Epindridione Pigment] 44.0 parts of the methyl ester of dihydroxyfumaric acid described in Example 1 was suspended in 158 parts of methanol.
108.1 parts of 4,5-trichloroaniline and concentrated hydrochloric acid 3
And heating at reflux for 6 hours. During the heating, the reaction solution once becomes a solution, and then pale yellow crystals precipitate. After cooling the reaction solution to 5 to 10 ° C., the precipitated crystals were filtered, and
By drying at 0 ° C., compound 109.
One part was obtained.

[0064]

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The above compound (106.4 parts) was added to Dowtherm A10
The suspension added in 64 parts was heated to 120 to 130 ° C. to form a solution, and this solution was heated under reflux to Dowtherm A4.
Add to 25 parts over 30 minutes. Then Dowtherm A
The mixture is refluxed and heated for 15 minutes while removing a mixed solution of and formed methanol, and cooled to room temperature. The precipitated crystals were washed with petroleum ether and dried at 70 ° C. to obtain 82.3 parts of a compound having the following structure.

[0066]

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75.0 parts of the above compound are added to 750 parts of polyphosphoric acid with stirring. The mixture is added for 15 hours in one hour.
After heating to 0 ° C., it is heated at 145 to 150 ° C. for 2 hours, and then cooled to 40 to 50 ° C. Next, 1660 parts of methanol are gradually added while maintaining 40 to 50 ° C. After the addition is completed, the mixture is heated under reflux for 90 minutes and filtered. Washing was carried out with water until the washing liquid became neutral, and dried to obtain 62.3 parts of a pigment represented by Compound No. 2 in Table 1. Using this pigment, toner base particles, a toner, and a developer were obtained in the same manner as in Example 1, and evaluated in the same manner.

Example 3 [Synthesis Step of Epindridione Pigment]
In 9 parts are added, with stirring, 14.3 parts of sodium ethoxide. After the sodium ethoxide has completely dissolved,
At room temperature, 29.2 parts of diethyl oxalate and N-
Add 49.6 parts of (3,4-dichlorophenyl) glycine ethyl ester and stir at 25 ° C. for 20 hours. Next, ethanol is distilled off under reduced pressure, 150 parts of water and 15 parts of acetic acid are added, and the mixture is vigorously stirred. Further toluene 10
After adding 4 parts, stirring a little, and allowing to stand at room temperature, the reaction solution separates into an oil layer and an aqueous layer. The aqueous layer is separated, extracted twice with 35 parts of toluene, the extract is mixed with the oil layer and filtered. The filtrate was washed with 120 parts of water, and toluene was removed by distillation under reduced pressure to give Compound 5 having the following structure.
8.4 parts were obtained.

[0069]

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52.2 parts of the above compound, 29.6 parts of 2,4,5-trichloroaniline and 1.8 parts of concentrated hydrochloric acid are heated under reflux for 3 hours in 101 parts of ethanol. Next, after removing 61 parts of ethanol by distillation under reduced pressure, the precipitated crystal was filtered and washed with 16 parts of ethanol.
To obtain 48.2 parts of a mixture composed of compounds having the following two structures.

[0071]

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[0072]

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The above compound (47.4 parts) was added to Dowtherm A474.
The suspension added in the mixture was heated to 120 to 130 ° C. to form a solution, and the solution was heated under reflux to Dowtherm A190.
Add to parts over 30 minutes. Then, reflux heating was performed for 1 while removing the mixture of Dowtherm A and the generated methanol.
Perform for 5 minutes and cool to room temperature. The precipitated crystals were washed with petroleum ether and dried at 70 ° C. to obtain 36.3 parts of a compound having the following structure.

[0074]

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33.6 parts of the above compound are added to 336 parts of polyphosphoric acid with stirring. The mixture is added for 15 hours in one hour.
After heating to 0 ° C., it is heated at 145 to 150 ° C. for 2 hours, and then cooled to 40 to 50 ° C. Next, 747 parts of methanol are gradually added while maintaining the temperature at 40 to 50 ° C. After the addition is completed, the mixture is heated under reflux for 90 minutes and filtered. The resultant was washed with water until the washing liquid became neutral, and dried to obtain 27.2 parts of a pigment represented by Compound No. 3 in Table 1. Using this pigment, toner base particles, a toner and a developer were obtained in the same manner as in Example 1, and evaluated in the same manner.

Comparative Examples 1 to 3 The following Comparative Examples 1 to 3 show examples in which only salting was performed and only flushing was performed. In Comparative Example 1, each pigment represented by Compound No. 1 in Table 1, in Comparative Example 2, Compound No. 2 in Table 1, and in Comparative Example 3, each pigment represented by Compound No. 3 in Table 1, was filtered after completion of washing with water after synthesis. As shown below, the aqueous paste was not subjected to the salt milling step, but only the flushing step was performed to obtain toner base particles, a toner, and a developer, which were similarly evaluated.

[Flushing Step] Aqueous paste: 125.0 parts (After synthesis, only washing and filtration, solid content: 40.0%) Unsaturated polyester resin: resin (E) 25.0 parts methanol as solid at room temperature 5 parts While heating the above raw material to 100 ° C with a kneader, about 30
Mix for a minute and transfer (flushing) the pigment to the resin,
Disperse uniformly in resin. After removing the separated water and solvent from the kneader, the remaining kneaded material was passed five times with a heating-type two roll to obtain a high-concentration pigment chip, that is, a resin-coated pigment.

[Toner Forming Step] Unsaturated polyester resin: binder resin (G) 100.0 parts Resin-coated pigment 5.0 parts Negative charge control agent 4.0 parts Next, the above raw materials are melted by an extruder. Knead. After cooling, the mixture was roughly pulverized using a hammer mill and then finely pulverized using a jet mill.
0.0 μm toner base particles are obtained. The toner base particles 1
0.4 parts of titanium oxide fine powder was added to 00.0 parts and mixed with a Henschel mixer to obtain a toner.

Comparative Examples 4 to 6 The following Comparative Examples 4 to 6 show examples of toners formed by a usual method. That is, neither salt milling nor flushing is performed. In Comparative Example 4, each pigment represented by Compound No. 1 in Table 1 was used. In Comparative Example 5, compound No. 2 in Table 1 was used. In Comparative Example 5, each pigment represented by Compound No. 3 in Table 1 was used. The toner mother particles, the toner, and the developer were obtained without passing through the flushing step, and evaluated in the same manner.

[Toner Forming Step] Pigment (not subjected to the salt milling step) 3.0 parts Unsaturated polyester resin: binder resin (G) 100.0 parts Negative charge control agent 3.0 parts Premix with a Henschel mixer,
Melt and knead with a twin-screw extruder. After cooling, the mixture is roughly pulverized using a hammer mill and finely pulverized using a jet mill, and then toner base particles having an average particle diameter of 10.0 μm are obtained using an air classifier. 0.4 parts of titanium oxide fine powder was added to 100 parts of the toner base particles and mixed with a Henschel mixer to obtain a toner.

In Examples 1 to 3, after the synthesis of the epidridione pigment, salt milling was performed, and further, a toner was formed through a flushing step. The images had high chroma and sharp images were obtained. Also, a clear image was obtained for the intermediate colors using the toners of the individual colors. When an image was formed on the OHP sheet, clear and remarkable transparency comparable to that of a dye was obtained. In addition, the obtained toner was melted by hot pressing to form a uniform thin layer on a glass plate, and the dispersion state was observed with an optical microscope. It was confirmed that the dispersion state was very good without aggregation. done.

In Comparative Examples 1 to 3, salt milling was not performed.
This is an example in which only flushing is performed. The image had a high saturation and a clear image was obtained. Also, a clear image was obtained for the intermediate colors using the toners of the individual colors. Although considerable transparency was obtained when an image was formed on the OHP sheet, it was inferior to Examples 1 to 4, and the effect of salt milling was confirmed.

In Comparative Examples 4 to 6, toners were formed by the same combination using the pigments and resins used in Examples 1 to 3 and Comparative Examples 1 to 3 by the usual production method. That is, neither salt milling nor flushing was performed. In Comparative Examples 4 to 6 above, clear and sufficient color reproducibility and color development were not obtained, and Example 1 and Comparative Example 1 using the same pigment were not obtained.
When the images of Comparative Example 4 and Comparative Example 4 were compared, the image quality decreased in this order, and the difference was clear.

[0084]

After refinement by salt milling,
Further, by using the flushed epidridione pigment as a colorant for the toner base particles, the pigment particle diameter in the toner base particles can be reduced, and clear and sufficient color reproducibility and color development can be obtained when an image is formed. Especially O
When an image was formed on a transparent substrate such as a sheet for HP, clear and remarkable transparency was obtained. Further, when the dispersion state of the pigment in the yellow toner was observed with a microscope, it was confirmed that the dispersion state was favorable without aggregation.

Claims (6)

[Claims] 1. An organic pigment (A) represented by the following general formula (1), a water-soluble inorganic salt (B), and a water-soluble solvent (C)
The mixture consisting of at least three components is mechanically kneaded, and then the aqueous paste (D) of the treated pigment obtained by washing and removing (B) and (C) with water and the resin (E) which is a solid at room temperature are heated and kneaded. And then subjecting the resin-coated pigment (F) obtained by removing water to kneading with a binder resin (G) under heating and kneading. General formula (1) However, in the formula, R _{1 to} R ₈ each independently represent a hydrogen atom or a halogen atom, and at least three of R _{1 to} R ₄ are halogen atoms. 2. A mixture comprising at least three components of the organic pigment (A) represented by the general formula (1), the water-soluble inorganic salt (B), and the water-soluble solvent (C) according to claim 1. An aqueous paste (D) of the treated pigment, which is obtained by mechanically kneading and then washing and removing (B) and (C), and a resin (E) which is a solid at room temperature, are heated and kneaded, and then water is removed. And a binder resin (G) obtained by heating and kneading the obtained resin-coated pigment (F) and the binder resin (G). However, in the formula, R _{1 to} R ₈ each independently represent a hydrogen atom, a fluorine atom or a chlorine atom, and at least three of R _{1 to} R ₄ are a fluorine atom or a chlorine atom. 3. A mixture comprising at least three components of the organic pigment (A) represented by the general formula (1), the water-soluble inorganic salt (B), and the water-soluble solvent (C) according to claim 1. An aqueous paste (D) of the treated pigment, which is obtained by mechanically kneading and then washing and removing (B) and (C), and a resin (E) which is a solid at room temperature, are heated and kneaded, and then water is removed. And a binder resin (G) obtained by heating and kneading the obtained resin-coated pigment (F) and the binder resin (G). Where R ₁ and R ₅ , R ₂ and R ₆ , R ₃ and R
₇ , R ₄ and R ₈ are each equal. R _{1 to} R ₄ each independently represent a hydrogen atom, a fluorine atom or a chlorine atom, and at least three are a fluorine atom or a chlorine atom. 4. The electrostatic charge according to claim 1, wherein the weight ratio of the water-soluble inorganic salt (B) to the water-soluble solvent (C) is 2 to 20 times. Yellow toner base particles for image development. 5. A yellow toner for developing an electrostatic charge image, comprising a mixture of the yellow toner base particles for developing an electrostatic charge image according to claim 1 and an external additive. 6. A yellow developer comprising a mixture of the yellow toner for developing an electrostatic image according to claim 5 and a carrier.