JPH1184728A - Toner matrix particles, toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the color reproducibility and color forming property by kneading a mixture of a specified insoluble azo pigment, a water-soluble inorg. salt and a water-soluble solvent to finely divide the azo pigment, carrying out washing, heating and kneading the resultant aq. paste and a resin, which is solid at ordinary temp., removing the water, heating and kneading the resultant resin coated pigment and a bonding resin. SOLUTION: A tetrazo component such as dichlorobenzidine, a compd. represented by formula I, etc., as a principal coupler component and a compd. represented by formula II, etc., are mixed and coupled to obtain an insoluble azo pigment. A mixture of the azo pigment, a water-soluble inorg. salt and a water-soluble solvent is kneaded to finely divide the azo pigment and the water-soluble inorg. salt and solvent are removed by washing to prepare an aq. paste of the insoluble azo pigment. The aq. paste and a resin, which is solid at ordinary temp., are heated and kneaded, the water is removed and the resultant resin coated pigment and a bonding resin are heated and kneaded to obtain the objective yellow toner matrix particles. In the formulae I, II, R1 -R3 , and R10 -R12 are individually H, CH3 , etc., and M is a metal or an amine salt.

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 developer formed using mother particles. More specifically, the present invention relates to a yellow toner base particle for developing an electrostatic image capable of forming a clear image having excellent color reproducibility and color developability, and a yellow developer formed by using the yellow toner base particle.

[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 advancement 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, magenta, cyan and yellow, 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 recording medium such as paper through development and transfer steps. Further, for the second and subsequent colors, the above-described steps are sequentially performed a plurality of times, and a plurality of color toners are superimposed on the same recording medium, 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 transparent substrates such as sheets for overhead projectors (hereinafter, abbreviated as OHP) has been increasing. As with the most common conventional black toner, the toner used for full-color image formation is required to have various characteristics, such as stable chargeability and good fluidity,
Transparency, sharpness, color reproducibility and the like are further required. That is, since a full-color image is obtained by superimposing a plurality of color toners on the material to be transferred as described above, if the light transmittance of each toner is insufficient, color reproducibility is deteriorated and a clear image is obtained. It is difficult to obtain an image. Especially OH
This phenomenon is remarkable when a full-color image is formed on a transparent substrate such as a sheet for P, 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 particle size of the pigment 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 down the secondary particles of the pigment (primary particles are weakly agglomerated) into primary particles. With the disperser described above, 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 another method for making the pigment finer, there is known a method in which the pigment and the solid resin are heated and kneaded with a two-roll mill or a Banbury mixer while being heated. However, since pigments generally grow at high temperatures, in such a method, the end point is reached when mechanical crushing and crystal growth are in an equilibrium state, and there is a limit to the fineness of the pigment.

Further, as a method of making the primary particles of the pigment fine, 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 for 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 transformed into the α-type crystal due to 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 dry milling.
However, in this method, there is a problem that the pigment easily undergoes strong secondary aggregation during drying, and the pigment particle size becomes large.

[0009]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional method, and provides clear and sufficient color reproducibility when a full-color image is formed using a full-color copying machine or printer. It is another object of the present invention to provide a yellow toner for developing an electrostatic image capable of obtaining color development, and a yellow developer containing the yellow toner and a carrier.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on how to uniformly disperse the pigment as fine particles in the toner, and found that a specific insoluble azo pigment (A) A water-soluble inorganic salt (B) is added as a crushing aid, a small amount of a water-soluble solvent (C) is added to the mixture as a wetting agent, and the mixture is kneaded vigorously with a kneader or the like. The salt (B) and the water-soluble solvent (C) are dissolved to form a slurry, and then the slurry is repeatedly filtered and washed with water to remove the inorganic salt (B) and the solvent (C). An aqueous paste (D) of an insoluble azo pigment (hereinafter abbreviated as aqueous paste (D)) is obtained, and a resin-coated pigment (F) obtained by flashing the aqueous paste (D) is used as a colorant for toner base particles. By the conventional And it reached the present invention that it is possible to obtain an image excellent in far clarity and transparency than.

That is, a first aspect of the present invention is to provide dichlorobenzidine or tetrachlorobenzidine as a tetrazo component, and at least one compound selected from the following general formulas (1) and (2) as a main coupler component. Of an insoluble azo pigment (A), a water-soluble inorganic salt (B), and a water-soluble solvent (C) obtained by mixing and coupling (3) and at least one compound selected from the general formula (4). An aqueous paste of the insoluble azo pigment (A) obtained by mechanically kneading a mixture consisting of at least three components to make the insoluble azo pigment (A) fine, and then removing (B) and (C) by washing with water ( D) is heated and kneaded with a room temperature solid resin (E), and then heated and kneaded with a resin-coated pigment (F) obtained by removing water and a binder resin (G). You A yellow toner base particles for developing electrostatic images.

General formula (1)

Embedded image

(R ₁ , R ₂ and R ₃ each independently represent H, CH ₃ , OCH ₃ , OC ₂ H ₅ or Cl.)

General formula (2)

Embedded image

(R ₄ is H, CH ₃ , OCH ₃ , Cl, O
H or COOC ₂ H ₅ , wherein R ₅ is H, CH ₃ , OC
It represents of H ₃ or COOC ₂ H _5. )

General formula (3)

Embedded image

(R ₆ , R ₇ and R ₈ are each independently:
H, CH ₃ , OCH ₃ , OC ₂ H ₅ , Cl, NH ₂ , X
-NR ₉ R ₉ 'or X-NH (CH ₂ ) _n NR ₉ R ₉ '
(Provided that at least one of R ₆ , R ₇ and R ₈ is NH ₂ , X-NR ₉ R ₉ ′ or X-NH (CH
₂ ) _n NR ₉ R ₉ ′. ), X is a direct bond or S,
Represents a divalent linking group consisting of a chemically rational combination composed of 2 to 50 atoms selected from C, N, O and H, n represents an integer of 1 to 4, R ₉ , R ₉ ′ independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, or R ₉ and R ₉ ′ are substituted with an alkyl group having 5 or less carbon atoms which may contain a nitrogen atom or an oxygen atom. Represents a 5- or 6-membered heterocyclic ring which may be contained as a group. )

General formula (4)

Embedded image

(R ₁₀ , R ₁₁ and R ₁₂ are each independently
H, CH ₃ , OCH ₃ , OC ₂ H ₅ , Cl, SO ₃ H,
Represents COOH, COOM or SO ₃ M (provided that R ₁₀ ,
At least one of R ₁₁ and R ₁₂ is SO ₃ H, CO
OH, COOM or SO ₃ M. ), M represents a metal or an amine salt. )

The second invention is characterized in that the water-soluble solvent (C) is used in an amount of 2 to 20 times by weight the water-soluble inorganic salt (B) with respect to the water-soluble solvent (C). Yellow toner base particles for charge image development.

According to a third aspect of the present invention, there is provided a yellow toner for developing an electrostatic image, comprising a mixture of the yellow toner base particles according to the first or second aspect and an external additive. It is.

A fourth invention is a yellow developer comprising a mixture of the yellow toner for developing an electrostatic image according to the third invention and a carrier.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The insoluble azo pigment (A) in the present invention reacts a tetrazo component with a plurality of coupler components as described above. In particular, 3,3'-dichlorobenzidine is used as a tetrazo component. Or 2,
One or two or more coupling components selected from acetoacetanilides represented by the general formula (1) and pyrazolones represented by the general formula (2) using 2 ', 5,5'-tetrachlorobenzidine It is preferably an insoluble azo pigment obtained by mixing and coupling a basic coupler or an acidic coupler.

As specific examples of the acetoacetanilide represented by the general formula (1), acetoacetanilide, acetoaceto-m-xylide, acetoaceto-o-toluidide, acetoaceto-p-toluid, acetoaceto-o-
Anisidide, acetoacet-p-anisidide, acetoacet-p-ethoxyanilide, acetoaceto-o-chloro-p-methoxyanilide, acetoaceto-2, 5-dimethoxyanilide, acetoaceto-p-chloroanilide, acetoaceto-2, 5-dimethoxy- 4-chloroanilide and the like. Specific examples of the pyrazolones represented by the general formula (2) include N-phenyl-3-methylpyrazolone, Np-tolyl-3-methylpyrazolone,
-Phenyl-3-propionyloxypyrazolone;

In the pigment obtained by the mixed coupling, since the molecules having different chemical structures are randomly arranged in the crystal concept, the size and shape of the particles are smaller than those of the pigment obtained by separately coupling. , Surface area, crystallinity, etc. In particular, the effect is remarkable in the mixed coupling of acetoacetanilides with a basic coupler or an acidic coupler, and a fine pigment excellent in heat resistance during salt milling can be obtained.

Specific examples of the basic coupler of the general formula (3) include 4-acetoacetylamino-N- [3- (diethylamino) propyl] benzenesulfonamide,
-Acetoacetylamino-N- [3- (2-methylpipecolyl) propyl] benzenesulfonamide, 4-acetoacetylamino-N- [3- (diethylamino) propyl] -3-chlorobenzenecarbamide, 4-acetoacetylamino- N- [3- (dipropylamino) propyl] -3-methylbenzylamine, 4-acetoacetylaminobenzamide, acetoacetoortho-N-methylaminoanilide, acetoacetoortho-N-stearylaminoanilide, acetoaceto-2- Chloro-4-
N, N-dimethylaminoanilide, acetoaceto-2-
Hydroxy-4-N, N-dimethylaminoanilide, 3
-Acetoacetylaminobenzenesulfonylamide and the like.

Specific examples of the acidic coupler of the general formula (4) include acetoaceto-2-carboxyanilide, acetoaceto-2-carboxy-4-chloroanilide, acetoaceto-2-carboxy-4-methylanilide, and acetoaceto-2- Carboxy-5-methylanilide, acetoaceto-2-carboxy-4-hydroxyanilide,
Acetoaceto-p-sulfonylanilide, acetoaceto-2-sulfonyl-4-chloroanilide, acetoaceto-2-sulfonyl-5-hydroxyanilide, 4-acetoacetoaminobenzenesulfonic acid, and their sodium, potassium and calcium salts Salt, barium salt,
Strontium salts, manganese salts, zinc salts, magnesium salts, aluminum salts, quaternary ammonium salts and the like.

Known methods may be used for the tetrazotization method and the coupling method. The amount of the acidic or basic coupler to be added is 0.1 to 30% by weight, preferably 1 to 10% by weight in the coupler component. If the amount is large, the dispersion of the pigment is adversely affected. If the amount is small, the effect on the heat resistance during kneading cannot be sufficiently exerted. The coupling slurry is heated as it is, or the sodium salt of rosin is added by adding sodium hydroxide to the alkali side of pH 10 or more, heated and stirred to 80 ° C., left for 30 minutes, and then added with hydrochloric acid to add an acidic solution of pH 5 or less. To cover the pigment surface with rosin. This is filtered and washed with water to obtain an aqueous paste (D).

Examples of the water-soluble inorganic salt (B) used for salt milling include salt, potassium chloride, sodium sulfate and the like.

The water-soluble solvent (C) used for salt milling is not particularly limited as long as it is water-soluble. However, the temperature rises during salt milling, and the solvent evaporates easily. A solvent having a high boiling point is also preferable from the viewpoint of the properties. Examples are 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, 1-ethoxy-2-propanol, 1-
Ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, low molecular weight polypropylene glycol and the like are used.

In addition to the above compounds, additives such as a dispersant and a plasticizer may be used in combination during salt milling, or two or more pigments may be mixed and treated.

[0032] A treated pigment having a finer particle diameter than that of an untreated pigment can be obtained by salt milling. However, after the drying step, the pigment is agglomerated, and a pigment having a large particle diameter is obtained. Easy to be formed. Very large energy is required to disperse this into small particle sizes again. The present invention provides an aqueous paste (D) of an insoluble azo pigment which has been subjected to a salt milling treatment, that is, an aqueous dispersion, which is dried by kneading (hereinafter, referred to as flushing) with a resin (E) which is a solid at room temperature without drying. The resin-coated pigment (F) maintaining the previous fine state is used as a colorant to form toner base particles for electrostatic image development. The preferred particle size of the resin-coated pigment (F) has an average particle size of 1.0 μm or less, more preferably 0.2 μm or less, as measured by laser scattering. With such a particle size, sharpness and transparency are extremely excellent when an image is formed.

As the resin (E) which is a solid at room temperature, that is, a resin which can be used for flushing, any solid resin at room temperature can be used, including known resins. In consideration of image transparency, a colorless and transparent resin is more preferable. For example, polystyrene, styrene-acrylate copolymer, styrene-butadiene copolymer, chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, Low molecular weight polypropylene,
Examples include ionomer resin, polyurethane resin, silicone resin, rosin / ester, and rosin. These resins can also be used for dilution and melt-kneading after flushing.

The resin-coated pigment (F) in the present invention can be obtained, for example, as follows. To the aqueous paste (D) of the insoluble azo pigment, a resin (E) which is a solid at room temperature and other various additives as necessary are added, and the mixture is stirred and mixed by a mixing and dispersing machine such as a kneader or a super mixer. 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 heated, if necessary, using two or three rolls to remove the water, and the resin-coated pigment (F) (pigment high concentration chip ).

The 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, and then melted using an extruder or the like. Perform kneading. Then, after cooling, coarsely pulverized by a hammer mill or the like, finely pulverized by a jet mill or the like, and classified by an air classifier or the like to obtain an average particle size of 5 to 20.
What is necessary is just to obtain a classified product having a predetermined particle size distribution of about μm.

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

It is also preferred that the toner base particles of the present invention contain a charge control agent. As the charge control agent, any known charge control agent can be used, but a colorless or light-colored one which does not affect the color tone of the toner 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 ditertiary butyl salicylic acid) can be given.

The toner base particles of the present invention preferably contain various particles as external additives, such 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,
In addition, it is preferable to add a fine powder of 1 to 50 μm such as polytetrafluoroethylene, polyvinylidene fluoride, polymethacrylate, polystyrene, or silicone. It is also preferable to add a mixture of the above and an external additive obtained by subjecting these fine powders to various surface treatments.

The developer of the present invention is obtained by mixing the above-mentioned toner and carrier, and can be obtained by a conventionally known method, and is not particularly limited. As the carrier used in the developer of 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.
As the conductive carrier, an oxidized or non-acid value iron powder or the like is usually used. A typical example of the insulating carrier is a carrier in which the surface of carrier core material particles made of a ferromagnetic material is uniformly coated with an insulating resin. Examples of the carrier core material include iron oxide (magnetite),
Particles of reduced iron, copper, ferrite, nickel, cobalt and the like and alloys thereof with zinc, aluminum and the like can be given. As the coating resin, 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, fluororesin, amino resin, etc. Any one may be used. 20 ~ 2 as a carrier
Those having a size of about 00 μm are preferred. In general, the developer preferably contains 1 to 30% by weight of a toner.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. In the examples, "parts" indicates parts by weight. [Example 1] A tetrazo solution was obtained from 25.3 parts of 3,3'-dichlorobenzidine according to a conventional method. On the other hand, a submerged solution was prepared using 36.3 parts of acetoaceto-o-toluidide and 3.7 parts of a basic coupler, 4-acetoacetylamino-N- [3- (diethylamino) propyl] benzenesulfonamide, according to a conventional method. did. A pigment slurry formed by adding a tetrazo solution to the undercoat and coupling the mixture is heated to 80 ° C., left for 30 minutes, and then filtered,
Washed with water and dried. The powder was pulverized with a pulverizer to form a powder. This pigment (A-1): 250 parts, sodium chloride:
2500 parts and 200 parts of diethylene glycol (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. This mixture is then 2.
The mixture was poured into 5 liters of warm water and stirred for about 1 hour with a high speed mixer while being heated to about 80 ° C. to form a slurry. Then, filtration and washing were repeated 5 times to remove sodium chloride and the solvent, and the solid content was 50%. Thus, an aqueous pigment dispersion (aqueous paste) was obtained.

Next, the process proceeds to a flushing step. The aqueous pigment dispersion (solid content: 50%) 100.0 parts Unsaturated polyester resin (normal temperature solid) 25.0 parts Methanol 0.5 part The above raw materials were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho), and 100 When the mixture was mixed while being heated to ℃, the pigment content was transferred to the resin (flushing) in about 10 minutes. After removing the separated water and solvent from the kneader, the remaining kneaded material was passed five times with a heating-type two roll,
A high concentration chip (resin-coated pigment) was obtained.

The above-mentioned unsaturated polyester resin 100.0 parts The above-mentioned pigment high-concentration chips 5.0 parts The negative charge control agent 4.0 parts Next, the above-mentioned raw materials were melt-kneaded with an extruder,
After cooling, the mixture is roughly pulverized with a hammer mill and further finely pulverized with a jet mill to obtain toner base particles having an average particle diameter of 10.0 μm. 0.4 parts of titanium oxide fine powder is added to 100 parts of the toner base particles and mixed with a Henschel mixer to obtain a toner.

6 parts of the obtained toner was added to 100 parts of ferrite and mixed with a ball mill mixer to obtain a developer. Using this developer, a commercially available full-color copying machine (CLC
350, manufactured by Canon Inc.), clear and sufficient color reproducibility and coloring were obtained. In particular, when an image was formed on an OHP sheet, remarkable improvement in transparency was observed as compared with the conventional case. Also, the obtained toner was melted by hot pressing to form a uniform thin layer on a glass plate, and the dispersion state of the pigment was observed with an optical microscope. Was confirmed.

Example 2 Acetoaceto-o of Example 1
-36.0 parts of acetoaceto-o-anisidide instead of toluidide, acetoaceto-2,5-dimethoxy-4-
5.2 parts of chloroanilide, 4- as a basic coupler
A pigment aqueous dispersion (aqueous paste) having a solid content of 50% was obtained in the same manner as in Example 1 except that 1.5 parts of acetoacetylaminobenzamide was used. Thereafter, in the same manner as in Example 1, toner base particles for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Example 3 Acetoaceto-o of Example 1
-Except using 42.3 parts of acetoaceto-o-chloroanilide instead of toluidide and 4.0 parts of 4-acetoacetylamino-N- [3- (dimethylamino) propyl] benbencarbamide as basic coupler. An aqueous pigment dispersion (aqueous paste) having a solid content of 50% was obtained in the same manner as in Example 1. Thereafter, in the same manner as in Example 1, toner base particles for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Example 4 Acetoaceto-o of Example 1
Acetoacetanilide instead of toluidide 33.6
Parts, a pigment aqueous dispersion having a solid content of 50% (the same as in Example 1) except that 3.2 parts of 4-acetoacetylamino-N- [3- (diethylamino) propyl] benzylamine was used as a basic coupler. Aqueous paste). Thereafter, in the same manner as in Example 1, toner base particles for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Example 5 Acetoaceto-o of Example 1
Acetoacetanilide instead of toluidide 33.6
, And aqueous dispersion of the pigment having a solid content of 50% in the same manner as in Example 1 except that 4.0 parts of 4-acetoacetylamino-N- [3- (2-methylpipeconyl) propyl] benzylamine was used as the basic coupler. A body (aqueous paste) was obtained. Thereafter, in the same manner as in Example 1, toner base particles for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Example 6 Acetoaceto-o of Example 1
Aceto-m-xylide 35.2 instead of toluidide
Parts, except that 2.3 parts of sodium 4-acetoacetylaminobenzenesulfonate was used as the acidic coupler in place of the basic coupler in the same manner as in Example 1.
% Aqueous pigment dispersion (aqueous paste) was obtained. afterwards,
In the same manner as in Example 1, a toner base particle for electrostatic image development, a toner and a developer were formed. The result is shown in Example 1.
Was similar to

Example 7 34.4 parts of acetoaceto-o-toluizide, acetoaceto-o-carboxyanilide as an acidic coupler instead of a basic coupler
A pigment aqueous dispersion (aqueous paste) having a solid content of 50% was obtained in the same manner as in Example 1 except that 4 parts were used. Thereafter, in the same manner as in Example 1, toner base particles for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Example 8 34.4 parts of acetoaceto-p-toluidide in place of acetoaceto-o-toluidide 4.7 parts of acetoaceto-2-carboxy-4-hydroxyanilide was used as an acidic coupler in place of the basic coupler. Other than the above, the solid content was 50 in the same manner as in Example 1.
% Aqueous pigment dispersion (aqueous paste) was obtained. afterwards,
In the same manner as in Example 1, a toner base particle for electrostatic image development, a toner and a developer were formed. The result is shown in Example 1.
Was similar to

Example 9 A tetrazo solution was obtained from 25.3 parts of 3,3′-dichlorobenzidine according to a conventional method. On the other hand, a submersion solution was prepared in accordance with a conventional method using 31.3 parts of N-phenyl-3-methylpyrazolone and 4.5 parts of a quaternary ammonium salt of 4-acetoacetylaminobenzenesulfonic acid as a basic coupler. A tetrazo solution was added to the underpoured solution for coupling. The resulting pigment slurry was adjusted to pH 10 by adding sodium hydroxide,
After heating to 0 ° C and standing for 30 minutes, the slurry was filtered, washed with water and dried. The powder was pulverized with a pulverizer to form a powder. Using this pigment, a pigment aqueous dispersion (aqueous paste) having a solid content of 50% was obtained in the same manner as in Example 1. Then, Example 1
In the same manner as in the above, a toner base particle for electrostatic image development, a toner and a developer were formed. The results were the same as in Example 1.

Comparative Example 1 A solid content of 50% was obtained in the same manner as in Example 1 except that 38.2 parts of acetoaceto-o-toluidide was used and a basic coupler was not used.
% Aqueous pigment dispersion (aqueous paste) was obtained. afterwards,
When toner base particles for electrostatic image development, toner and developer were formed in the same manner as in Example 1, and an image was formed in the same manner, the image was significantly reduced.

[0053]

As described above, according to the present invention, toner base particles for electrostatic image development, and a toner and a developer having a small particle diameter of the pigment in the toner, and providing clear and sufficient color reproducibility and color development can be obtained. When the dispersion state of the pigment in the toner was observed with an optical microscope, it was confirmed that the dispersion state was very good without aggregation.

Claims (4)

[Claims] 1. A method according to claim 1, wherein dichlorobenzidine or tetrachlorobenzidine is a tetrazo component, and at least one compound selected from the following general formulas (1) and (2) is a main coupler component. It comprises at least three components of an insoluble azo pigment (A), a water-soluble inorganic salt (B), and a water-soluble solvent (C) obtained by mixing and coupling with at least one compound selected from (4). The mixture is mechanically kneaded to make the insoluble azo pigment (A) finer, and then (B) and (C) are washed with water to remove the insoluble azo pigment (A).
The aqueous paste (D) and the room temperature solid resin (E) are heated and kneaded, and then the resin-coated pigment (F) obtained by removing water and the binder resin (G) are heated and kneaded. Yellow toner base particles for developing an electrostatic charge image. General formula (1) (R ₁ , R ₂ and R ₃ are each independently H, CH ₃ ,
Represents OCH ₃ , OC ₂ H ₅ or Cl. ) General formula (2) (R ₄ is H, CH ₃ , OCH ₃ , Cl, OH or COO
Represents C ₂ H ₅ , wherein R ₅ is H, CH ₃ , OCH ₃ or CO
Represents OC ₂ H ₅ . ) General formula (3) (R ₆ , R ₇ and R ₈ are each independently H, CH ₃ ,
_{OCH 3, OC 2 H 5,} Cl, NH 2, X-NR
₉ R ₉ ′ or X—NH (CH ₂ ) _n NR ₉ R ₉ ′ (provided that at least one of R ₆ , R ₇ and R ₈ is
_{NH 2, X-NR 9 R} 9 ' , or X-NH (CH _{2) n}
NR ₉ R ₉ ′. ), X is a direct bond or S, C,
Represents a divalent linking group consisting of a chemically rational combination composed of 2 to 50 atoms selected from N, O and H, n represents an integer of 1 to 4, R ₉ , R ₉ Each independently represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or R ₉ and R ₉ ′, which may contain a nitrogen atom or an oxygen atom, and an alkyl group having 5 or less carbon atoms as a substituent. Represents a 5- or 6-membered hetero ring which may be possessed. ) General formula (4) (R ₁₀ , R ₁₁ and R ₁₂ are each independently H, CH ₃ ,
OCH ₃ , OC ₂ H ₅ , Cl, SO ₃ H, COOH, C
OOM or SO ₃ M (provided that at least one of R ₁₀ , R ₁₁ and R ₁₂ is SO ₃ H, COOH, COO
M or SO ₃ M. ), M represents a metal or an amine salt. ) 2. The electrostatic image developing yellow 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. Toner mother particles. 3. A yellow toner for developing an electrostatic image, comprising a mixture of the yellow toner base particles according to claim 1 and an external additive. 4. A developer comprising a mixture of the yellow toner for developing an electrostatic image according to claim 3 and a carrier.