JPH1152622A - Toner base grain, toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrostatic image developing toner base grain that can obtain sufficient color reproducibility and coloring property with clearness by containing a specific pigment. SOLUTION: A solution with an organic pigment dissolved in sulfuric acid is put in water to obtain a fine deposit, and the fine deposit is treated at 40-200 deg.C in lower alcohol with the carbon number of 1-5 under the presence of a pigment dispersant to form a pigment. An aqueous solution with the organic pigment deposited by bringing organic pigment dissolved liquid into contact with continuously flowing water is filtered to separate water and a product, and the product is washed with water, ion-exchange water or an alkaline aqueous solution of low concentration so as to be formed into a paste state with 10-40 wt.% of solid part content. The thus obtained pigment is used as a coloring agent for toner base grain, particularly the fine deposite manufactured by putting the solution with the organic pigment dissolved in sulfuric acid, into continuously flowing water is used as the coloring agent so as to obtain an image excellent in clearness and more transparent than a conventional one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 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 toner base particle. And a developer formed using the toner. More specifically, when copying or the like is performed using magenta, cyan, yellow, and black toners, a clear and sufficient color reproducibility, a toner mother particle for developing an electrostatic image capable of obtaining color development, and the toner mother particles are provided. The present invention relates to a toner and a developer formed by use.

[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 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 a plurality of color toners are superimposed on the same transfer material, 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 refining the primary particles of the pigment, a method is known in which the 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. I have. Pigments refined by this method cause strong secondary agglomeration when dried, so it is very difficult to re-disperse the dried ones to primary particles.Also, as a method for improving dispersibility, alcohol or the like is used. Heat treatment in a solvent is also known, but is undesirable because crystal growth occurs and the pigment particle size increases.

[0008]

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 an object of the present invention to provide a toner base particle for developing an electrostatic image capable of obtaining a color developing property, and a toner and a developer using the toner base particle.

[0009]

According to the present invention, a solution in which an organic pigment is dissolved in sulfuric acid is poured into water to form fine precipitates, and then a lower alcohol having 1 to 5 carbon atoms is present in the presence of a pigment dispersant. The toner base particles for developing an electrostatic image are characterized by containing a pigment processed at a medium temperature of 40 to 200 ° C.

According to a second aspect of the present invention, there is provided the toner base particles for developing an electrostatic image according to the first aspect, wherein a solution in which an organic pigment is dissolved in sulfuric acid is poured into continuously flowing water.

In a third aspect, the organic pigment is a quinacridone pigment, a phthalocyanine pigment, a benzimidazolone pigment, a diketopyrrolopyrrole pigment, a perinone pigment,
The toner mother particles for electrostatic image development according to the first or second aspect, wherein the mother particles are one selected from the group consisting of anthraquinone pigments, dioxazine pigments, perylene pigments, and isoindolinone pigments. is there.

A fourth invention is characterized in that the pigment dispersant is at least one of the compounds represented by the following general formulas (1), (2) and (3): A toner base particle for developing an electrostatic charge image according to any one of the inventions. Formula (1) P- (X- (CH 2) n -N (R 1) R 2 ] _m Formula (2) P- [X- (CH _{2) n} -Y] _m Formula (3) P -(SO ₃ H) _m (where P is an organic dye residue or a heterocyclic residue, X
Is SO ₂ NH or CONH, Y is SO ₃ H or CO
OH, R ¹ and R ² each independently form an optionally substituted alkyl group having 1 to 18 carbon atoms or a heterocyclic ring which may have a substituent with R ¹ and R ^2. And n represents an integer of 1 to 6, and m represents an integer of 1 to 3. ]

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

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

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a solution in which an organic pigment is dissolved in sulfuric acid is poured into water to form fine precipitates (hereinafter, this step is referred to as acid pasting). By using a treated pigment treated at 40 to 200 ° C. in a lower alcohol as a colorant for toner base particles, a solution in which an organic pigment is dissolved in sulfuric acid is particularly poured into continuously flowing water. By using the fine precipitate produced by the thing as a colorant,
This makes it possible to obtain an image which is more transparent and clearer than before.

When a solution prepared by dissolving an organic pigment in concentrated sulfuric acid is poured into water, constant conditions are always maintained from the first stage to the last stage of the operation by pouring into a continuously flowing water. As a result, not only fine particles are stably generated, but also particles having a constant quality can be obtained. When the liquid in which the organic pigment is dissolved in concentrated sulfuric acid is thrown into the retained water, the liquid temperature rises sharply due to the heat of dissolution when the sulfuric acid is dissolved in the water, and finely divided organic pigment crystals grow. Due to the tendency, it is preferable to pour into continuous flowing water.

More specifically, the continuously flowing water used in the present invention means water flowing through a pipe or tube having a water pressure of 0.5 to 4.5 kg / cm ² . The liquid obtained by dissolving the organic pigment in concentrated sulfuric acid is added to the continuous flowing water quantitatively by using a water jet aspirator, or the liquid obtained by dissolving the organic pigment in concentrated sulfuric acid is added in a volume of 0.5%. It is preferable to pressurize to 4.5 kg / cm ² and spray water continuously flowing from the capillary.

An aqueous solution in which an organic pigment is dissolved in concentrated sulfuric acid is brought into contact with a continuously flowing water to precipitate an organic pigment, and the aqueous solution is filtered to separate water and a product. Washed with an alkaline aqueous solution of, for example, an aqueous solution of caustic soda or caustic potassium, and the solid content is 10 to 40.
It is good to make it into paste by weight.

Further, the above-mentioned acid-pasted organic pigment is treated in a lower alcohol having 1 to 5 carbon atoms in the presence of 0.1 to 20% by weight of a pigment dispersant. The pigment dispersant prevents crystal growth of the pigment at the time of treatment at 40 to 200 ° C. in a lower alcohol having 1 to 5 carbon atoms, and improves the dispersibility as fine crystals. Next, the pigment that has been subjected to the alcohol treatment is washed with water, dried, and pulverized, and used as a colorant for a toner for developing an electrostatic image (hereinafter, referred to as a treated pigment).

The use of pigments fined by acid pasting, the subsequent treatment of such pigments with alcohol in the presence of a pigment dispersant, the development of a treated pigment obtained by using these methods in combination, and the development of an electrostatic image. By using it as a colorant for toner base particles for use, an image which is clearer and has excellent color reproducibility and color developability than before can be formed.

The organic dye constituting the organic dye residue in the general formulas (1) to (3) includes phthalocyanine, quinacridone, benzimidazolone, anthraquinone, and the like.
Examples include dioxazine, diketopyrrolopyrrole, anthraquinone, anthanthrone, indanthrone, flavanthrone, perinone, perylene, thioindigo and the like. These dyes can be arbitrarily selected, but it is industrially advantageous to use a dye having a hue close to the pigment used. Further, as the heterocyclic ring constituting the heterocyclic residue, for example, thiophene, furan, xanthene,
Pyrrole, imidazole, isoindolinone, isoindoline, benzimidazolone, indole, quinoline,
Examples include carbazole, acridine, acridone, anthraquinone and the like.

The substituent added to the organic dye residue or the heterocyclic residue P is-(X- (CH ₂ ) _n -N
(R ¹ ) R ² ] _m or-[X- (CH ₂ ) _n -Y] _m
Or a -SO ₃ H _m, X is SO ₂ NH, or CON
H and Y are SO ₃ H or COOH, and R ¹ and R ² are each independently substituted with an optionally substituted alkyl group having 1 to 18 carbon atoms or R ¹ and R ^2. May form a heterocyclic ring, n is an integer of 1 to 6, m is 1 to
Represents an integer of 3.

The method for producing the pigment dispersant is firstly a known method.
To the organic dye or heterocycle _TwoCl-, -COC
l-, -CH_TwoCl-, -CH_TwoNHCOCH_TwoCl-
And the like. In the general formula (1),-(C
H_Two)_n−N (R¹) R^TwoAn amine component having the structure
The reaction is performed to obtain a pigment dispersant of the general formula (1). These nets
As the component, for example, N, N-dimethylaminomethyl
, N, N-dimethylaminoethyl, N, N-dimethyl
Aminopropyl, N, N-dimethylaminoamyl, N,
N-dimethylaminobutyl, N, N-diethylamino
Chill, N, N-diethylaminopropyl, N, N-die
Tylaminohexyl, N, N-diethylaminoethoxy
Propyl, N, N-diethylaminobutyl, N, N-di
Ethylaminopentyl, N, N-dipropylaminobuty
, N, N-dibutylaminopropyl, N, N-dibutyl
Aminoethyl, N, N-dibutylaminobutyl, N,
N-diisobutylaminopentyl, N, N-methyl-la
Urylaminopropyl, N, N-ethyl-hexylami
Noethyl, N, N-distearylaminoethyl, N, N
-Dioleylaminoethyl, N, N-distearylamido
Amine or alcohol of nobutyl or N-amino
Noethylpiperidine, N-aminoethyl-4-pipecoli
, N-aminoethylmorpholine, N-aminopropyl
Piperidine, N-aminopropyl-2-pipecholine, N
-Aminopropyl-4-pipecholine, N-aminopropyl
Rumorpholine, N-aminomethylpiperidine, or N
-Hydroxymethylpiperidine, N-hydroxyethyl
Piperidine, N-hydroxypropylpiperidine, N-
Hydroxyethyl pipecoline, N-hydroxypropyl
Pipecoline, N-hydroxymethylpyrrolidine, N-hi
Droxyethylmorpholine, N-hydroxybutylmol
Holin and the like. These pigment dispersants have 1 to 5 carbon atoms.
0.1-20 weight of pigment when treated with lower alcohol
% Is desirable.

The solvent used in the present invention is a C1-C5 lower alcohol, specifically methanol, ethanol, n
-Propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol. These solvents are preferably used in an amount of 1 to 30 times by weight based on the solid content of the water paste having a solid content of 10 to 30% by weight of the pigment. Treat at ° C.

When a finely divided pigment is treated with a lower alcohol having 1 to 5 carbon atoms and a solvent that is not completely miscible with water is used, a nonionic surfactant such as polyoxyethylene alkyl is further added. Ether, sorbitan fatty acid ester, polyoxyethylene fatty acid ester,
Glycerin fatty acid ester or the like, or anionic surfactant such as fatty acid salt, alkyl sulfate salt, alkyl benzene sulfonate, alkyl sulfosuccinate or the like is added at 0.2 to 20% by weight to the pigment. Is also possible.

The preferred particle size of the treated pigment is such that the average particle size measured by laser scattering is 1.0 μm or less,
More preferably, it is 0.2 μm or less. With such a particle size, a clear and sufficient color reproducibility and coloring property can be obtained when an image is formed.

In the case of the black toner base particles among the toner base particles of the present invention, the three processed pigments of yellow, cyan and red may be obtained, and these three processed pigments may be used as the colorant. In the case of black toner base particles among the toner base particles of the present invention, use of carbon black as a colorant is not prevented.

The toner base particles of the present invention can be obtained according to a conventional method. That is, a binder resin and, if necessary, other charge control agents and additives are added to the above treated pigment, preliminarily mixed with a Henschel mixer or the like, and then melt-kneaded using an extruder or the like. 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 a classified product having an average particle size of about 5 to 20 μm and a predetermined particle size distribution.

As the binder resin of the toner base particles of the present invention, conventionally known binder resins can be widely used, but colorless and transparent resins are more preferable in consideration of image transparency. 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, Examples include molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, rosin ester, rosin and the like. The production method of any resin is not particularly limited.

It is also preferred that the toner base particles of the present invention contain a charge control agent. As the charge control agent, any of known positive and negative charges can be used, but a colorless or light-colored charge control agent which 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 preferably used.

The toner base particles of the present invention preferably contain various particles as an external additive as a fluidity improver, a cleaning aid and the like. 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 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.

[0033]

The present invention will be described in more detail with reference to the following examples. In the examples, parts and% indicate parts by weight and% by weight, respectively. In addition, the pigment dispersants a to
The types of h are shown in the table below. _{a: Q-SO 2 NH (} CH 2) 3 N (C 2 H 5) 2 b: Q-SO 2 NH (CH 2) 3 N (C 4 H 9) 2 c: Q-SO 3 H d: P _{-SO 2 NH (CH 2) 3} N (C 2 H 5) 2 e: P-SO 3 H f: B-CONH (CH 2) 3 N (C 2 H 5) 2 g: A-CONH (CH 2 ) ₃ N (C ₂ H ₅ ) ₂ where Q represents a quinacridone residue, P represents a phthalocyanine residue, B represents a benzimidazolone residue, and A represents an anthraquinone residue.

Example 1 30 parts of Hosta Palm Pink E (quinacridone pigment, manufactured by Hoechst) and 98% sulfuric acid 30
0 parts are weighed into a 1 liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate is collected by filtration and adjusted to pH
The resultant was washed with water to 6.8 to obtain a water paste having a solid content of 10.50%. The obtained water paste, 0.9 part of the pigment dispersant a and 300 parts of isobutanol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then heated at 90 ° C.
For 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 30.0%. It is dried and pulverized and used as a colorant for toner base particles.

The above colorant for toner base particles 3.0 parts Unsaturated polyester resin 100.0 parts Negative charge control agent 3.0 parts
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 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 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. Further, 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 by an optical microscope. As a result, it was found that the dispersion state was very good without aggregation.

[Examples 2 and 3] Instead of the pigment dispersant a used in Example 1, 0.9 parts each of the pigment dispersant b (Example 2) and the pigment dispersant c (Example 3) were used. Except for the above, toner mother particles, a toner and a developer were obtained.

Comparative Example 1 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were prepared. Hosta Palm Pink E (quinacridone pigment, manufactured by Hoechst) 10.0 parts Unsaturated polyester resin 100.0 parts As in Example 1, a commercially available full-color copying machine (CLC35)
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 4 Lionol Blue FG-7
351 (phthalocyanine pigment, manufactured by Toyo Ink Manufacturing Co., Ltd.) 3
0 parts and 300 parts of sulfuric acid are weighed into a 1-liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate is collected by filtration, washed with water until pH 7.0, and solid content is 10.50%.
Water paste was obtained. The obtained water paste, 0.9 parts of the pigment dispersant d and 300 parts of diethylene glycol were placed in a 1-liter flask equipped with a cooling tube, stirred at room temperature for 30 minutes, and then treated at 80 ° C. for 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 40.0%. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Example 5 Toner base particles, a toner and a developer were obtained in the same manner except that 0.9 parts of the pigment dispersant e was used instead of the pigment dispersant d used in Example 4. .

Comparative Example 2 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Lionol Blue FG-7351 (Phthalocyanine pigment, manufactured by Toyo Ink Mfg. Co., Ltd.) 10.0 parts Unsaturated polyester resin 100.0 parts As in Example 1, a commercially available full-color copying machine (CLC35)
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 6 Hosta Palm Yellow H3
30 parts of G (benzimidazolone pigment, manufactured by Hoechst) and 300 parts of sulfuric acid are weighed into a 1-liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate was collected by filtration and washed with water to pH 7.0 to obtain a water paste having a solid content of 10.50%. The obtained water paste and pigment dispersant f
0.9 parts and 300 parts of isobutanol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then treated at 90 ° C. for 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 35.0%. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Comparative Example 3 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Hosta Palm Yellow H3G (benzimidazolone pigment, manufactured by Hoechst) 10.0 parts Unsaturated polyester resin 100.0 parts As in Example 1, a commercially available full-color copying machine (CLC35)
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 7 Irgazine DPP RED
BO (diketopyrrolopyrrole pigment manufactured by Ciba Geigy)
30 parts and 300 parts of sulfuric acid are weighed into a 1 liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate was collected by filtration, washed with water until pH 7.0, and solid content was 10.50.
% Water paste was obtained. The obtained water paste, 0.9 part of the pigment dispersant a and 300 parts of isobutanol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then treated at 90 ° C. for 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 30.0%. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Example 8 Toner base particles, toner and developer were obtained in the same manner except that 0.9 parts of pigment dispersant c was used instead of pigment dispersant a used in Example 7. .

Comparative Example 4 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Irgazine DPP RED BO (diketopyrrolopyrrole pigment, Ciba-Geigy) 10.0 parts Unsaturated polyester resin 100.0 parts Commercial full-color copier (CLC35) as in Example 1.
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 9 Chromophthal Red A2B
(Anthraquinone pigment, Ciba-Geigy) 30 parts and 9
300 parts of 8% sulfuric acid is weighed into a 1 liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate was collected by filtration and washed with water to pH 6.8 to obtain a water paste having a solid content of 10.50%. The obtained water paste and pigment dispersant g
0.9 parts and 300 parts of diethylene glycol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then treated at 80 ° C. for 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 30.0%. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Comparative Example 5 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Chromophthal Red A2B (anthraquinone pigment, manufactured by Ciba Geigy) 10.0 parts Unsaturated polyester resin 100.0 parts As in Example 1, a commercially available full-color copying machine (CLC35)
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 10 Irgazine Red BPT
(Perylene pigment, Ciba Geigy) 30 parts and 98 parts of 98% sulfuric acid are weighed into a 1 liter glass beaker,
Stir for 1 hour to fully dissolve. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate was collected by filtration and washed with water to pH 6.8 to obtain a water paste having a solid content of 10.50%. The obtained water paste and the pigment dispersant b0.
9 parts and 300 parts of diethylene glycol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then treated at 80 ° C. for 1 hour. Filter the pigment-treated product,
After washing with water, a pigment-treated product having a solid content of 30.0% was obtained. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Comparative Example 6 The following materials were mixed and melt-kneaded in an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Irgazine Red BPT (Perylene pigment, manufactured by Ciba Geigy) 10.0 parts Unsaturated polyester resin 100.0 parts As in Example 1, a commercially available full-color copying machine (CLC35)
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

Example 11 Irgazi Yellow 2 GLT
30 parts of E (isoindolinone pigment, manufactured by Ciba Geigy) and 300 parts of sulfuric acid are weighed into a 1-liter glass beaker, stirred for 1 hour, and sufficiently dissolved. The entire amount of the dissolved solution was dropped in one minute through an aspirator connected to a water flow set at a gauge pressure of 3.50 kg / cm ² . The precipitate was collected by filtration and washed with water to pH 7.0 to obtain a water paste having a solid content of 10.50%. The obtained water paste and pigment dispersant f
0.9 parts and 300 parts of diethylene glycol were placed in a flask equipped with a 1-liter cooling tube, stirred at room temperature for 30 minutes, and then treated at 80 ° C. for 1 hour. The pigment-treated product was collected by filtration and washed with water to obtain a pigment-treated product having a solid content of 40.0%. Using the obtained pigment-treated product, the same operation as in Example 1 was performed to obtain toner base particles, a toner, and a developer.

Comparative Example 7 The following materials were mixed and melt-kneaded with an extruder. Thereafter, in the same manner as in Example 1, toner base particles, a toner and a developer were obtained. Irgazi Yellow 2GLTE (isoindolinone pigment, Ciba-Geigy) 10.0 parts Unsaturated polyester resin 100.0 parts Commercially available full-color copier (CLC35) as in Example 1.
0, manufactured by Canon Inc.), the image quality was degraded. In particular, when an image was formed on an OHP sheet, the transparency was extremely poor.

[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.

Claims (6)

[Claims] 1. A solution prepared by dissolving an organic pigment in sulfuric acid is poured into water to form a fine precipitate, which is then treated in a lower alcohol having 1 to 5 carbon atoms at 40 to 200 ° C. in the presence of a pigment dispersant. And toner base particles for developing an electrostatic image. 2. The method according to claim 1, wherein a solution in which an organic pigment is dissolved in sulfuric acid is thrown into continuously flowing water.
The toner mother particles for electrostatic image development according to the above. 3. The organic pigments are quinacridone pigments, phthalocyanine pigments, benzimidazolone pigments, diketopyrrolopyrrole pigments, perinone pigments, anthraquinone pigments, dioxazine pigments, perylene pigments, and isoindolinone pigments. 3. The toner base particles for developing an electrostatic image according to claim 1, wherein the base particles are one kind selected from the group consisting of pigments. 4. A pigment dispersant represented by the following general formula (1):
4. The toner base particles for developing an electrostatic image according to claim 1, which is at least one of the compounds represented by (2) and (3). Formula (1) P- (X- (CH 2) n -N (R 1) R 2 ] _m Formula (2) P- [X- (CH _{2) n} -Y] _m Formula (3) P -(SO ₃ H) _m (where P is an organic dye residue or a heterocyclic residue, X
Is SO ₂ NH or CONH, Y is SO ₃ H or CO
OH, R ¹ and R ² each independently form an optionally substituted alkyl group having 1 to 18 carbon atoms or a heterocyclic ring which may have a substituent with R ¹ and R ^2. And n represents an integer of 1 to 6, and m represents an integer of 1 to 3. ] 5. An electrostatic image developing toner comprising a mixture of an electrostatic image developing toner base particle according to claim 1 and an external additive. 6. A developer comprising a mixture of the toner for developing an electrostatic charge image according to claim 5 and a carrier.