JP2000081733A - Toner matrix particles, toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain electrostatic charge image developing toner matrix particles which ensure clear satisfactory color reproducibility and color forming property when a full-color image is formed and to obtain a toner using the toner matrix particles and a developer. SOLUTION: A soln. prepd. by dissolving an org. pigment and a pigment dispersant of the formula P-[X-Y-Z-N(R1)R2]n in sulfuric acid is put in water, a fine deposit is formed and filtration and washing are repeatedly carried out to obtain a treated pigment. An aq. paste of the treated pigment 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 toner matrix particles. In the formula, P is the residue of an org. dye, the residue of a heterocycle or the like, X is a divalent bonding group consisting of 2-15 atoms selected from S, C, N, O and H, Y is a direct bond or-N(R)-(R is H, 1-18C alkyl or the like), Z is 1-6C alkylene, R1 and R2 are each 1-18C alkyl or the like (n) is an integer of 1-3.

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-resolution 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 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 recording medium.

[0005] 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. Today, toners used for full-color image formation are required to have various properties, such as stable chargeability and good fluidity, as in the case of the most common conventional black toners.
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 a recording medium 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 particularly remarkable 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 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, pigments generally have the property of agglomerating when dried, and using a normal disperser such as a sand mill, three-roll mill, ball mill, or extruder, breaks the agglomerated state of the agglomerated pigment and returns to the original primary particles. For this purpose, a dry pigment is dispersed and kneaded together with a resin and a solvent to obtain a pigment dispersion pair such as a paint or ink. However, a large amount of energy is required for the dispersion and kneading.

[0008] A resin or a resin solution is added to an aqueous slurry or an aqueous paste containing a pigment at a high concentration before drying, and mixed and stirred to replace the water around the pigment with the resin or the resin solution. Removing the solvent is generally referred to as flushing. In this method, since there is no step of drying the pigment, the aggregation of the pigment is less likely to occur, and the pigment particles can be coated with the resin in a fine state. The body is obtained.

Patent Nos. 2097052 and 2507
No. 779, No. 2507780, No. 2568252,
JP-A-06-161154, JP-A-07-234
No. 543, JP-A-07-319206 and the like disclose a method in which this flushing step is applied to the production of an electrostatic image developing toner. As the formation of full-color images with 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 further improved 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 plural colors is superimposed on the same recording medium. When combined to form a full-color image, color reproducibility closer to the original can be obtained. 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, sharpness and transparency of the image are improved.
Is required.

[0010]

According to the present invention, when a full-color image is formed by using a full-color copying machine or a printer, a clearer and more satisfactory image can be obtained by dispersing the pigment more finely than the conventional flushing method. It is an object of the present invention to provide toner base particles for electrostatic image development capable of obtaining color reproducibility and color developability, and a toner and a developer using the toner base particles.

[0011]

The first invention comprises an organic pigment (A) and a pigment dispersant (B) represented by the following general formula (1).
A solution in which sulfuric acid was dissolved in sulfuric acid was poured into water to form fine precipitates, and then an aqueous paste (C) of the treated pigment obtained by repeating filtration and washing and a resin (D) as a solid at room temperature were heated and kneaded. And then kneading the resin-coated pigment (E) obtained by removing the water with the binder resin (F) under heating and kneading. General formula (1) P- [XYZN (R ¹ ) R ² ] _n (where P is an organic dye residue or a heterocyclic residue, or an aromatic polycyclic compound residue, X is a divalent linking group consisting of a chemically rational combination composed of 2 to 15 atoms selected from S, C, N, O and H, Y is a direct bond or-
N (R)-(where R is H or an alkyl group having 1 to 18 carbon atoms or ZN (R ¹ ) R ² ) or -O-, Z is an alkylene group having 1 to 6 carbon atoms, R ¹ , R ² is each independently
An optionally substituted alkyl group having 1 to 18 carbon atoms or an optionally substituted heterocyclic ring which may contain N, O or S together with R ¹ and R ^2, and n represents an integer of 1 to 3, respectively. . )

[0012] A second aspect of the present invention is to throw a solution obtained by dissolving an organic pigment (A) and a pigment dispersant (B) represented by the above general formula (1) in sulfuric acid into continuously flowing water. The toner base particles for developing an electrostatic image according to the first aspect of the present invention.

The third invention is characterized in that the organic pigment (A) is quinacridone pigment, phthalocyanine pigment, benzimidazolone pigment, diketopyrrolopyrrole pigment, perinone pigment, anthraquinone pigment, dioxazine pigment, perylene. A pigment selected from the group consisting of pigments based on azo pigments, isoindolinone pigments and azo pigments.
Or the toner mother particles for developing an electrostatic image according to the second invention.

According to a fourth 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 third aspects and an external additive. It is.

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

[0016]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a solution in which an organic pigment (A) and a pigment dispersant (B) are dissolved in sulfuric acid is poured into water to form fine precipitates. The aqueous paste (C) of the treated pigment obtained by repeating filtration and washing is dispersed in a resin (D) which is a solid at room temperature by a flushing method, and the resin-coated pigment (E) is dispersed.
And by using this as a colorant for the toner base particles, a solution in which the organic pigment (A) and the pigment dispersant (B) are dissolved in sulfuric acid is thrown into continuously flowing water. Aqueous paste of the treated pigment obtained by repeating filtration and washing into a fine precipitate produced by the method (C)
Is dispersed in a room temperature solid resin (D) by a flushing method to obtain a resin-coated pigment (E) in which a fine pigment is kept in a dispersed state, and by using such a resin-coated pigment (E), This makes it possible to obtain a clear and excellent image.

When a solution prepared by dissolving the organic pigment (A) and the pigment dispersant (B) in sulfuric acid is poured into water, the liquid is poured into a continuously flowing water to form a liquid from the first step to the last step. Since constant conditions are always maintained until the stage, not only fine particles are stably generated, but also particles of constant quality can be obtained. When the liquid in which the organic pigment is dissolved in sulfuric acid is thrown into retained water, the liquid temperature rises sharply due to the heat of dissolution when the sulfuric acid dissolves in water, and the finely divided organic pigment crystals tend to grow. , 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 . In order to add a liquid in which an organic pigment or the like is dissolved in sulfuric acid to the water that is continuously flowing, quantitatively using a water aspirator, or a liquid in which the organic pigment is dissolved in sulfuric acid is 0.5 to It is preferred to pressurize to 4.5 kg / cm ² and to spray water continuously flowing from the capillary.

An aqueous solution in which an organic pigment (A) and a pigment dispersant (B) are dissolved in sulfuric acid is brought into contact with continuously flowing water to precipitate an organic pigment and the like. And washed with water, ion-exchanged water or a dilute alkaline aqueous solution, for example, an aqueous solution of caustic soda or caustic potassium to form an aqueous paste (C) having a solid content of 10 to 40% by weight.

The particle size of the treated pigment after completion of the acid pasting is preferably 0.2 μm or less, more preferably 0.1 μm, based on the average particle size by centrifugal sedimentation.
It is as follows. It has been found that with such a particle size, when an image is formed, clear and sufficient color reproducibility and color developability are easily obtained.

Examples of the organic pigment (A) used in the present invention include quinacridone pigments such as quinacridone red and quinacridone magenta; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; benzimidazolone pigments; diketopyrrolopyrrole pigments; Perinone pigments, anthraquinone pigments, dioxazine pigments,
Perylene red, perylene pigments such as perylene scarlet, isoindolinone pigments, azo pigments and the like are used, quinacridone pigments, phthalocyanine pigments, benzimidazolone pigments, diketopyrrolopyrrole pigments,
It is preferable to use perinone pigments, anthraquinone pigments, dioxazine pigments, perylene pigments, isoindolinone pigments, azo pigments and the like. Further, a surface-treated pigment obtained by adding a functional group to the surface of the pigment may be used.

Among the toner base particles of the present invention, in the case of black toner base particles, three colored processing pigments of yellow, cyan and red may be obtained, and these three colored processing pigments may be used as a coloring agent. In the present invention, among the toner base particles, in the case of black toner base particles, the use of carbon black as a colorant is not prevented. As the carbon black, all known ones such as channel black, furnace black and lamp black can be used.

The pigment dispersant (B) represented by the general formula (1)
Prevents the re-agglomeration of pigment particles fined by acid pasting and is effective also in the subsequent dispersing step, and improves transparency, color reproducibility, and color development when an image is formed. In the general formula (1), the organic dye constituting the organic dye residue represented by P includes phthalocyanine, insoluble azo, azo lake, anthraquinone, quinacridone, dioxazine, diketopyrrolopyrrole, and anthrapyrimidine. System, anthanthrone system, indanthrone system, flavanthrone system, perinone system, perylene system, thioindigo system and the like. These dyes can be arbitrarily selected, but those having a hue close to the pigment used are industrially more advantageous. Examples of the heterocyclic ring constituting the heterocyclic residue include, for example, thiophene, furan, xanthene, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, indole, quinoline, carbazole, acridine, acridone, anthraquinone and the like. is there. When P is a heterocyclic ring, the pigment dispersant of the general formula (1) is preferable in terms of versatility, since a pigment that is hardly colored can be obtained.

In the general formula (1), X is S, C, N, O, H
A divalent linking group consisting of a chemically rational combination consisting of 2 to 15 atoms selected from, for _{example, -SO 2 -, - CO -} , - CH 2 -, - O-, -C
OO -, - NH-, or a combination thereof, preferably _{-SO 2 -, - CO -,} - CH 2 -, - CH 2
NHCOCH _2- and the like. When R ¹ and R ² are alkyl groups, lower alkyl groups such as a methyl group, an ethyl group, a propyl group and a butyl group are preferred. These alkyl groups may be branched or substituted up to a maximum of 18 carbon atoms. Further, in some cases, R ¹ and R ² may combine to form a 5- or 6-membered heterocyclic ring containing N, O or S.

The pigment dispersant (B) of the present invention is in the form of a dry powder, added to the organic pigment (A), dissolved together in sulfuric acid, and the solution is poured into water to form fine precipitates. That is, in these steps, the primary particle diameter of the pigment can be made smaller than before, and the pigment dispersant can be more strongly adsorbed on the pigment surface.

The resin-coated pigment (E) can be obtained, for example, as follows. The resin (D) at room temperature is added to the aqueous paste (C) of the treated pigment, and other various additives are added as required, and the mixture is mixed and stirred by a mixing and dispersing machine such as a kneader or a super mixer. At this time, heating may be performed if necessary. In about 10 to 20 minutes, the pigment content is transferred to the resin. The separated water is removed by decantation, the remaining kneaded material is heated as necessary, and water is removed using two or three rolls.
What is necessary is just to obtain the resin-coated pigment (E)).

As the resin (D) which is a solid at room temperature, that is, a resin which can be used for flashing, any known solid at room temperature can be used. Considering the transparency of the image, a colorless and transparent resin is preferred. 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. The production method of any resin is not particularly limited.

The toner base particles of the present invention can be obtained according to a conventional method. That is, the binder resin (F) and, if necessary, other charge control agents and additives are added to the resin-coated pigment (E) and premixed with a Henschel mixer or the like. Thereafter, melt kneading is performed using an extruder or the like. Then, 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.

As the binder resin (F), that is, a resin that can be used for melt-kneading after flushing, known resins can be widely used. Considering the transparency of the image, a colorless and transparent resin is more preferable. Although it is possible to use the same kind of resin as the above-mentioned ordinary temperature solid resin (D), it is not always necessary that the binder resin (F) and the ordinary temperature solid resin (D) match.

The toner base particles of the present invention preferably contain a charge control agent. As the charge control agent, any known charge control agent can be used, but a colorless or light-colored charge control agent that 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 di-tert-butylsalicylic acid) can be given.

Toner particles can be obtained by adding various particles as external additives to the toner base particles of the present invention as a fluidity improver, a cleaning aid and the like. Any known external additives can be used. For example, 0.01-0.
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, and other 1 to 50 μm polytetrafluoroethylene; It is preferable to add a fine powder such as polyvinylidene fluoride, polymethyl methacrylate, polystyrene, or silicone. It is also preferable to add an external additive obtained by variously surface-treating these mixtures and these fine powders.

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 for the 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. Examples of the core material of the carrier include particles of iron oxide (magnetite), reduced iron, copper, ferrite, nickel, cobalt, and the like, and alloys of these with zinc, aluminum, and the like. Acrylic resin as coating resin,
Any of known materials such as an epoxy resin, a silicone resin, a urethane resin, a polyacetal resin, a polyamide resin, a polycarbonate resin, a phenol resin, a vinyl acetate resin, a cellulose resin, a polyolefin resin, a fluororesin, and an amino resin may be used. The carrier preferably has a particle size of about 20 to 200 μm. Generally, the developer preferably contains 1 to 30% of toner.

[0033]

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. Table 1 shows typical examples of the pigment dispersants a to n used in the examples.

[0034]

[Table 1]

Example 1 Lionol Blue FG-7
330 (Phthalocyanine pigment, manufactured by Toyo Ink Manufacturing Co., Ltd.)
28 parts, 2 parts of compound a as a pigment dispersant, and 300 parts of sulfuric acid
The mixture is weighed and placed in 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
After washing with water to 7.0 and filtering, an aqueous paste (C1) having a solid content of 40.0% was obtained.

Next, the process proceeds to a flushing step. The above aqueous paste (C1) 125.0 parts Unsaturated polyester resin (: room temperature solid resin (D)) 25.0 parts Methanol 0.5 parts 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 mill to obtain a high-concentration pigment chip, that is, a resin-coated pigment (E1).

Unsaturated polyester resin (: binder resin (F)) 100.0 parts High-concentration pigment chip (: resin-coated pigment (E1)) 5.0 parts Negative charge control agent 4.0 parts The raw materials are melt-kneaded with an extruder. After cooling, the mixture was roughly pulverized using a hammer mill and then finely pulverized using a jet mill.
0.0 μm colorant-containing fine particles, that is, toner base particles are obtained. An average particle diameter of 0.
0.4 parts of 05 μm titanium oxide fine powder was added 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. 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.

[Examples 2 to 4] Instead of compound a used in Example 1, Example 2: Compound b Example 3: Compound c Example 4: Compound d Same as Example 1 except that each was used. Then, a toner and a developer were obtained, and the image was evaluated. The result was the same as that in Example 1.

Example 5 28 parts of Hostaperm Pink E (a quinacridone pigment, manufactured by Hoechst) was used as a pigment instead of Lionol Blue FG-7330, and 2 parts of compound e was used instead of compound a as a pigment dispersant. An aqueous paste (C5) having a solid content of 30.0% was obtained in the same manner as in Example 1 except that the paste was used.

Next, the process proceeds to a flushing step. Except for using 167.0 parts of aqueous paste (C5) in place of 125.0 parts of aqueous paste (C1), a high-concentration pigment chip, that is, resin-coated pigment (E5), toner base particles, When a toner and a developer were obtained and the image was evaluated, the result was the same as in Example 1.

[Examples 6 to 8] In the same manner as in Example 1 except that the compound e used in Example 5 was replaced with Example 6: Compound f Example 7: Compound g Example 8: Compound h Then, toner base particles, a toner and a developer were obtained, and the image was evaluated. The results were the same as in Example 5.

Example 9 Hansa Brilliant Yellow 5GX02 (monoazo pigment, Hoechst) instead of Lionol Blue FG-7330 was used as a pigment.
Part of compound i in place of compound a as a pigment dispersant
In the same manner as in Example 1 except that the toner base particles,
When a toner and a developer were obtained and the image was evaluated, the result was the same as in Example 1.

Example 10 Compound i used in Example 9
Was used in place of compound j to form toner base particles, a toner and a developer. When an image was evaluated using this developer, the same results as in Example 9 were obtained.

Example 11 Irgazi Yellow 2GL was used in place of Lionol Blue FG-7330 as a pigment.
28 parts of TE (isoindolinone-based pigment, Ciba-Geigy), compound k instead of compound a as a pigment dispersant
Was used in the same manner as in Example 1 except that 2 parts of was used to obtain toner base particles, a toner and a developer, and the image was evaluated.
The result was the same as in Example 1.

Example 12 A toner base particle, a toner and a developer were formed by using the compound 1 in place of the compound k used in the example 11. When an image was evaluated using this developer, the same results as in Example 11 were obtained.

[Comparative Example 1] Lionol Blue FG-7
330 (Phthalocyanine pigment, manufactured by Toyo Ink Manufacturing Co., Ltd.)
28 parts, 2 parts of the pigment dispersant a and 300 parts of sulfuric acid are weighed into a 1-liter glass beaker, and stirred for 1 hour to be sufficiently dissolved. The total amount of the dissolved solution was measured at a gauge pressure of 3.50 kg / cm ^2.
The solution was dropped in one minute through an aspirator connected to the water flow set in the step (1). The precipitate is collected by filtration, washed with water to pH 7.0, filtered, dried and pulverized, and used as a colorant for producing toner base particles.

The above colorant 3.0 parts Unsaturated polyester resin 100.0 parts Negative charge control agent 3.0 parts After cooling, coarsely pulverized by using a hammer mill, then finely pulverized by a jet mill, and then subjected to air classification Average particle size 10,0
A colorant-containing fine particle of μm, that is, a toner base particle is obtained. To 100 parts of the coloring agent-containing fine particles, 0 and 4 parts of titanium oxide fine powder having an average particle diameter of 0.05 μm are added 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.) and evaluated.
The image had a high saturation and a clear image was obtained. Although considerable transparency was obtained when an image was formed on the OHP sheet, it was inferior to Examples 1 to 4 using the same pigment, and the effect of flushing was confirmed.

Comparative Examples 2 to 4 Comparative Example 2: Lionol Blue FG-733 as a pigment
28 parts of Hosta Palm Pink E (a quinacridone pigment, Hoechst) instead of 0, 2 parts of compound e instead of compound a as a pigment dispersant, Comparative Example 3: Lionol Blue FG-733 as a pigment
28 parts of Hansa Brilliant Yellow 5GX02 (monoazo pigment, Hoechst) instead of 0, 2 parts of compound i instead of compound a as a pigment dispersant, Comparative Example 4: Lionol Blue FG-733 as a pigment
In the same manner as in Comparative Example 1 except that 28 parts of Irgazi Yellow 2GLTE (isoindolinone-based pigment, manufactured by Ciba Geigy) was used instead of 0, and 2 parts of compound i was used instead of compound k as a pigment dispersant, respectively. Then, toner mother particles, a toner and a developer were obtained, and the image was evaluated. The result was the same as that of Comparative Example 1.

Comparative Example 5 The following materials were premixed with a Henschel mixer and melt-kneaded with an extruder. Lionol Blue FG-7330 3.0 parts (Phthalocyanine pigment, manufactured by Toyo Ink Manufacturing Co., Ltd.) Unsaturated polyester resin 100.0 parts Negative charge control agent 3.0 parts After cooling, coarsely pulverized using a hammer mill, Next, after finely pulverizing with a jet mill, the average particle size was 10, 0 with an air classifier.
A colorant-containing fine particle of μm, that is, a toner base particle is obtained. To 100 parts of the coloring agent-containing fine particles, 0 and 4 parts of titanium oxide fine powder having an average particle diameter of 0.05 μm are added 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. When an image was obtained using a commercially available full-color copying machine (CLC350, manufactured by Canon Inc.) using this developer, clear and sufficient color reproducibility and coloring were not obtained, and Examples 1-4 using the same pigment were compared. When comparing the images side by side with Example 1, the difference was evident.

[Comparative Examples 6 to 8] Lionol Blue FG-7330 (phthalocyanine pigment,
Comparative Example 6: Hostaperm Pink E (quinacridone pigment, manufactured by Hoechst) instead of Toyo Ink Mfg. Comparative Example 7: Hansa Brilliant Yellow 5GX02 (monoazo pigment, manufactured by Hoechst) Comparative Example 8: Toner mother particles, a toner and a developer were obtained in the same manner as in Comparative Example 5 except that Irgazine Yellow 2GLTE (isoindolinone-based pigment, manufactured by Ciba Geigy) was used, and an image was obtained in the same manner. The image quality was lower than in each of the examples, and particularly when an image was formed on an OHP sheet, the transparency was remarkably inferior.
For example, using the same pigment, Examples 5 to 8, Comparative Example 2,
When the images were compared side by side with No. 6, the image quality decreased in this order, and the difference was obvious.

[0053]

According to the present invention, the pigment particle diameter in the toner base particles is small, clear and sufficient color reproducibility and color developability are obtained, and particularly when an image is formed on a transparent substrate such as an OHP sheet. As a result, toner base particles, a toner, and a developer for developing an electrostatic image, which can obtain clear and remarkable transparency, were obtained. When the dispersion state of the pigment in the toner mother particles was observed with a microscope,
It was confirmed that the particles were in a good dispersion state without aggregation.

Claims (5)

[Claims] 1. A solution in which an organic pigment (A) and a pigment dispersant (B) represented by the following general formula (1) are dissolved in sulfuric acid is poured into water to form fine precipitates, and then filtered and washed. The resin-coated pigment (E) obtained by heating and kneading the aqueous paste (C) of the treated pigment obtained by repeating the above process and a resin (D) which is a solid at room temperature is removed from the binder resin (F). ) And heat-kneading, the toner base particles for developing an electrostatic image. General formula (1) P- [XYZN (R ¹ ) R ² ] _n (where P is an organic dye residue or a heterocyclic residue, or an aromatic polycyclic compound residue, X is a divalent linking group consisting of a chemically rational combination composed of 2 to 15 atoms selected from S, C, N, O and H, Y is a direct bond or-
N (R)-(where R is H or an alkyl group having 1 to 18 carbon atoms or ZN (R ¹ ) R ² ) or -O-, Z is an alkylene group having 1 to 6 carbon atoms, R ¹ , R ² is each independently
An optionally substituted alkyl group having 1 to 18 carbon atoms or an optionally substituted heterocyclic ring which may contain N, O or S together with R ¹ and R ^2, and n represents an integer of 1 to 3, respectively. . ) 2. A method in which a solution in which an organic pigment (A) and a pigment dispersant (B) represented by the general formula (1) are dissolved in sulfuric acid is thrown into continuously flowing water. The toner base particles for developing an electrostatic image according to claim 1. 3. An organic pigment (A) comprising a quinacridone pigment, a phthalocyanine pigment, a benzimidazolone pigment, a diketopyrrolopyrrole pigment, a perinone pigment, an anthraquinone pigment, a dioxazine pigment, a perylene pigment, 3. The toner base particles according to claim 1, wherein the toner base particles are one selected from the group consisting of indolinone pigments and azo pigments. 4. A toner for developing an electrostatic image, comprising a mixture of the toner base particles for developing an electrostatic image according to claim 1 and an external additive. 5. A developer comprising a mixture of the toner for developing an electrostatic charge image according to claim 4 and a carrier.