JPH1172964A - Toner mother particles and toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the yellow toner capable of obtaining sharp and sufficient color reproduction performance and development performance by incorporating a benzimidazolone type pigment obtained by coupling >=2 kinds of diazotization products derived from a specified aromatic amine with 5- acetoacetylaminobenzimidazolone. SOLUTION: The benzimidazolone type pigment is prepared by coupling the >=2 kinds of diazotization products derived from the aromatic amine represented by formula I with the 5-aceto-acetylaminobenzimidazolone represented by formula II. In formula I, each of X and Y is, independently, an H or halogen atom or a -NO2 , -CONHR<1> , -COOR<2> , -CF3 , -CN, 1-6C alkyl, or 1-18C alkoxy group; R<1> is an H atom or a 1-18C alkyl or aryl group; and R<2> is an H atom or a 1-6C alkyl group.

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 More specifically, the present invention relates to a yellow toner base particle for developing an electrostatic image capable of obtaining clear and sufficient color reproducibility and color developability when performing copying or the like, and a toner and a developer formed using the 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 toners of a plurality of colors on a recording medium as described above, if 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 O
This phenomenon is remarkable when a full-color image is formed on a transparent substrate such as an HP 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, 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 a means for making the primary particles fine, there is known a method in which a pigment dissolved in a strong acid such as concentrated sulfuric acid or polyphosphoric acid is poured into cold water to precipitate the pigment as fine particles. However, since pigments fined by this method cause strong secondary aggregation when dried, it is very difficult to re-disperse the dried pigment to primary particles. Heat treatment in a solvent such as alcohol is known as a method for improving dispersibility, but this is not desirable because crystal growth occurs and the pigment particle size increases.

Further, as a method for making the primary particles of the pigment fine, a mixture of the pigment and a water-soluble inorganic salt such as sodium chloride or sodium sulfate is moistened with a small amount of a solvent such as polyethylene glycol, and the mixture is ground with a strong force such as a kneader. After crushing, there is a method in which an inorganic salt and a solvent are washed away with water and dried to obtain a fine pigment of primary particles. This method also requires a large amount of energy for grinding, and requires a large amount of cost for treating a large amount of rinsing wastewater, resulting in high production costs.

[0009]

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

[0010]

[Means for Solving the Problems]

The first invention comprises two or more diazotized reactants obtained from an aromatic amine represented by the following general formula (1) and 5-acetoacetylaminobenzimidazo represented by the following chemical formula (2). And a benzimidazolone-based pigment obtained by a coupling reaction with lon.

[0012]

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(Where X and Y in the formula are independent of each other;
^{_{-H, -NO 2, -CONHR 1,}} -COOR 2, -C
F ₃ , —CN, a halogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, and R ¹ represents —
H represents an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ² represents -H or an alkyl group having 1 to 6 carbon atoms. In the above general formula (1), a halogen atom is a fluorine atom, a chlorine atom, a bromine atom or the like; an alkyl group is a methyl group, an ethyl group, a butyl group, an isopropyl group, a hexyl group or the like; are methoxy, ethoxy, butoxy group, stearyl group, oleyloxy group, and examples of the R ^1, the above-described alkyl group,
Examples of R ² such as a phenyl group, a tolyl group, and an ethylphenyl group include the above-described alkyl groups and the like, but are not limited to these substituents.

[0014]

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According to a second aspect of the present invention, there is provided an electrostatic image developing toner comprising a mixture of the toner particle according to the first aspect and an external additive.

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

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The benzimidazolone pigment used in the present invention has an extremely vivid hue from a bluish yellow to a reddish yellow and is used as a colorant for toner base particles for developing an electrostatic image. Can be used widely. The method for producing the benzimidazolone pigment used in the present invention will be described in detail. Two or more kinds of various aromatic amines as specifically shown in Table 1 (where the substitution position of the amino group is 1) are optional. , Preferably different aromatic amines are mixed at a ratio of 1 mol% or more based on the total number of moles of the aromatic amine to be used, and a diazotization reaction is carried out according to a conventional method. It can be produced by a coupling reaction with imidazolone, and two or more kinds of compound molecules of the general formula (3) form pigment crystal particles.

[0018]

[Table 1]

[0019]

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The above aromatic amine is usually prepared by using sodium nitrite in water in the presence of a mineral acid such as hydrochloric acid or sulfuric acid.
The diazotization reaction is preferably performed at a temperature of 20 ° C. or lower to produce a diazo liquid. The diazotization reaction can also be carried out by using a hydrophilic solvent other than water, such as alcohol, acetone, and dioxane, and similarly using sodium nitrite in the presence of a mineral acid such as hydrochloric acid or sulfuric acid. On the other hand, 5-acetoacetylaminobenzimidazolone is usually added at room temperature together with an equimolar amount or more of sodium hydroxide or potassium hydroxide at room temperature to prepare a so-called coupler liquid as an aqueous solution. Also, 5-acetoacetylaminobenzimidazolone is dissolved in water together with sodium hydroxide and potassium hydroxide, and an acid such as acetic acid is added thereto to precipitate fine 5-acetoacetylaminobenzimidazolone from a weakly acidic medium. Slurry liquids are often used as coupler liquids.
Further, similarly to the above diazotization reaction, a hydrophilic solvent such as alcohol, acetone and dioxane can be used. A coupling reaction (mixing coupling) is performed by injecting the diazo solution prepared by the above method at room temperature or under heating into this coupler solution, and the benzimidazolone used for the toner base particles for developing an electrostatic image of the present invention is used. A pigment can be produced.

The coupling reaction proceeds smoothly under both acidic and alkaline conditions.
A clearer pigment can be obtained by adjusting the pH to pH 9 with hydrochloric acid or an aqueous sodium hydroxide solution. After the coupling reaction, the mixture is filtered and washed with water until neutral, and the obtained aqueous paste may be dried and used as a colorant, or may be used without drying. Further, at the time of the coupling reaction, various surfactants such as nonionic, cationic, anionic and zwitterionic, various water-soluble resins such as rosin, various organic solvents such as butyl acetate, xylene and isobutyl alcohol are added, and the pigment is added. When the surface treatment is performed, aggregation can be prevented and dispersion becomes easy. When performing surface treatment with rosin, after completing the coupling reaction, make the reaction solution alkaline, add various sodium rosin aqueous solutions, and further add calcium chloride, barium chloride, etc., and coat the pigment surface with an insoluble rosin salt. . Instead of adding calcium chloride or barium chloride, the pigment surface may be coated with rosin after being made acidic with a mineral acid or the like. As the rosin, gum rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleated rosin, fumarated rosin, wood rosin and the like can be used.

A feature of the above-mentioned production method is that two or more aromatic amines are mixed at an arbitrary ratio to carry out a diazotization reaction to carry out a coupling reaction. The benzimidazolone pigment obtained by this method is , Different in chemical structure 2
It is a mixture of two or more kinds of compounds, and such a mixture is obtained by individually diazotizing an aromatic amine, and then simply mixing a pure pigment obtained by coupling reaction with a mixture of pure pigments. Physical properties such as surface area and crystallinity are completely different. This difference in properties is caused by the random arrangement of molecules with different chemical structures in the crystal structure. In particular, the primary particles of the pigment are remarkably small compared to a pure benzimidazolone pigment obtained by subjecting one kind of aromatic amine to a diazotization reaction and a coupling reaction without mixing, resulting in a pigment having a remarkably large surface area. .

As the colorant for the toner base particles for developing an electrostatic image, it is preferable that the primary particles of the pigment used are finer, and it has been found that the above-mentioned benzimidazolone pigment is most suitable as the colorant. When the above-mentioned benzimidazolone pigment is used as a colorant for a toner for developing an electrostatic image, a clear image having excellent color reproducibility and color developability can be obtained.

Further, since the benzimidazolone pigment of the present invention is extremely fine particles, it is not necessary to further reduce the size using a large amount of energy as in the prior art, which is industrially more advantageous. The benzimidazolone pigment used in the present invention also has very weak aggregation of primary particles, and uses a large amount of energy even in a dispersion process when producing a colored composition using these pigments, that is, toner base particles. The toner base particles can be easily dispersed without necessity, and the toner base particles can be easily manufactured at lower cost.

In order to improve the dispersion of the pigment, a dispersing aid such as a derivative of the pigment may be added. As the pigment derivative, a basic compound obtained by introducing a dialkylamino group or the like as a terminal substituent into an organic dye, for example, the following general formulas (4) and (5) can be used. It is not limited to derivatives.

[0026]

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(Where A is CO, SO ₂ , CH ₂
A linking group such as NHCOCH ₂ , B represents an alkyl group, and n represents an integer. The dispersing aid such as a pigment derivative is excellent in dispersing the pigment and has a large effect of preventing re-aggregation of the pigment after the dispersion. Therefore, by using the pigment derivative or the like, the benzimidazo of the above-mentioned very fine particles can be obtained. It is possible to produce toner base particles for developing an electrostatic image capable of maximizing the properties of a lon-based pigment and forming a clear and excellent image with excellent color reproducibility and coloring. These derivatives may be added when the above-mentioned benzimidazolone-based pigment is dispersed in the toner base particles. However, when the above-mentioned benzimidazolone-based pigment is produced, the aromatic compound shown in Table 1 is used. The amine and an aromatic amine represented by the following general formulas (6) and (7) may be mixed and simultaneously subjected to a diazotization reaction and then a coupling reaction.

[0028]

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(However, A, B and n in the formula have the same meanings as in the general formulas (4) and (5).)

The toner base particles of the present invention can be obtained according to a conventional method. That is, the benzimidazolone-based pigment is added with a binder resin and, if necessary, other charge control agents and additives, and premixed 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 for 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 resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, Molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, rosin ester, rosin and the like can be mentioned. The production method of any resin is not particularly limited.

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-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.

[0035]

The present invention will be specifically described below with reference to examples. In the examples, "parts" all indicate parts by weight, and "%"
All indicate% by weight.

Example 1 6.2 parts of 1-amino-2-methoxybenzene (aromatic amine 25 in Table 1) and 1-amino-4-nitrobenzene (aromatic amine 3 in Table 1)
9 parts and 31 parts of 35% hydrochloric acid were added to 200 parts of ice water, then a solution prepared by dissolving 7.0 parts of sodium nitrite in 50 parts of water was added at 5 ° C. or lower, and the mixture was stirred for 1 hour to carry out a diazotization reaction to carry out a diazotization reaction. Was prepared. On the other hand, 23.3 parts of 5-acetoacetylaminobenzimidazolone and 16 parts of sodium hydroxide are dissolved in 1000 parts of ice water by stirring at 10 ° C or lower, and 220 parts of a 12% aqueous acetic acid solution is stirred at 10 ° C or lower in this solution. Then, fine crystals of 5-acetoacetylaminobenzimidazolone were precipitated to prepare a weakly acidic coupler solution having a pH of about 5. While stirring the coupler solution, the above diazo solution was added at 20 ° C. or lower and stirred for 3 hours. The mixture was further heated to 70 ° C. and stirred for 1 hour, and then filtered and washed with water to obtain a desired benzimidazolone yellow pigment a. 123 parts (solid content: 30%) of an aqueous paste was obtained. It is dried and pulverized and used as a toner colorant.

The toner colorant (pigment a) 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. To 100.0 parts of the obtained toner base particles, 0.4 part of titanium oxide fine powder is 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 color development were obtained. 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.

(Comparative Example 1)
Using only 12.3 parts of 1-amino-2-methoxybenzene (aromatic amine 25 in Table 1), 129 parts of an aqueous paste of pure benzimidazolone-based yellow pigment b (solid Min 28%). Also, 1-
Amino-4-nitrobenzene (aromatic amine 3 in Table 1)
Using only 13.8 parts, 123 parts (solid content 31%) of an aqueous paste of pure benzimidazolone yellow pigment c was obtained in the same manner as in Example 1 above. Instead of the aqueous paste of the pigment a, a total of 48 parts of the aqueous paste obtained by mixing 25 parts of the water cake of the pigment b and 23 parts of the water cake of the pigment c. The composition having the same composition as the aqueous paste of the pigment a) is dried and pulverized to obtain a mixture of the pigment b and the pigment c.

In place of the toner colorant (pigment a) of Example 1, a mixture of the above-mentioned pigments b and c was used as a toner colorant. When the toner base particles, the toner and the developer were obtained and the image was evaluated in the same manner, the image quality was remarkably deteriorated, and the difference in transparency was evident particularly when the image was formed on the OHP sheet.

(Example 2) 1-Amino-2- of Example 1
1-amino-2 instead of 6.2 parts of methoxybenzene,
3. 5-dichlorobenzene (aromatic amine 15 in Table 1)
9 parts and 11.3 parts of 1-amino-4-trifluoromethylbenzene (aromatic amine 12 in Table 1) instead of 6.9 parts of 1-amino-4-nitrobenzene A coupling reaction was performed with 23.3 parts of 5-acetoacetylaminobenzimidazolone to obtain 160 parts (solid content: 25%) of a water cake of benzimidazolone yellow pigment d. It was dried and pulverized to obtain a colorant for toner (pigment d).

In place of the toner colorant (pigment a) of Example 1, pigment d was used as the toner colorant. An agent was obtained, and the dispersion state of the image and the pigment was evaluated in the same manner.

(Comparative Example 2)
Using only 16.2 parts of amino-2,5-dichlorobenzene (aromatic amine 15 in Table 1), 148 parts (solid) of an aqueous paste of pure benzimidazolone yellow pigment e was obtained in the same manner as in Example 1. Min 27%). Similarly, using only 16.1 parts of 1-amino-2-trifluoromethylbenzene (aromatic amine 12 in Table 1), an aqueous paste 160 of pure benzimidazolone yellow pigment f was prepared in the same manner.
(Solid content 25%). Instead of the aqueous paste of the pigment a, a total of 55 parts of an aqueous paste of 16 parts of the aqueous paste of the pigment e and 39 parts of the aqueous paste of the pigment f were mixed. The ratio of the amine becomes almost the same composition as the aqueous paste of the pigment d) is dried and pulverized to obtain toner base particles for electrostatic image development, a toner and a developer in the same manner as in Example 2 below. As a result of evaluation, the image quality was remarkably deteriorated, and a difference in transparency was apparent particularly when an image was formed on an OHP sheet.

Example 3 1.4 parts of anthranilic acid (aromatic amine 9 in Table 1), 14.5 parts of 1-amino-2-trifluoromethylbenzene (aromatic amine 12 in Table 1) and 35% 31 parts of hydrochloric acid were added to 300 parts of ice water, and then a solution prepared by dissolving 7.0 parts of sodium nitrite in 50 parts of water was added.
The solution was added at a temperature of not more than ° C and stirred for 1 hour to carry out a diazotization reaction to prepare a diazo solution. On the other hand, 23.3 parts of 5-acetoacetylaminobenzimidazolone and 16 parts of sodium hydroxide are dissolved in 1500 parts of ice water by stirring at 10 ° C. or lower, and 220 parts of a 12% aqueous acetic acid solution is stirred at 10 ° C. or lower in this solution. The mixture was added all at once to precipitate fine crystals of 5-acetoacetylaminobenzimidazolone, thereby preparing a weakly acidic coupler liquid having a pH of about 5. While stirring the coupler solution, the above diazo solution was added at a temperature of 20 ° C. or less, and the mixture was stirred for 3 hours. The mixture was further heated to 80 ° C. and stirred for 1 hour. 133 parts of aqueous paste of imidazolone yellow pigment g (solid content 30%)
I got This was dried and pulverized to obtain a toner colorant (pigment g).

Using the toner colorant (pigment g) thus obtained, toner base particles, a toner and a developer for electrostatic charge image development were obtained in the same manner as in Example 1, and the dispersion of the image and the pigment was similarly performed. When the state was evaluated, it was the same as in Example 1.

(Comparative Example 3)
Using only 13.7 parts of anthranilic acid (aromatic amine 9 in Table 1), 127 parts (solid content: 30%) of an aqueous paste of pure benzimidazolone yellow pigment h was obtained in the same manner as in Example 3 above. Was. Instead of the aqueous paste of the pigment g, 4.8 parts of the aqueous paste of the pigment h and the pigment f of the comparative example 2 were used.
59.1 parts of an aqueous paste obtained by mixing 59.3 parts of the aqueous paste (when the aqueous paste is mixed at this ratio, the ratio of the amine evaluated in moles is almost the same as that of the aqueous paste of the pigment g). Was dried and pulverized to obtain toner base particles for electrostatic image development, a toner and a developer in the same manner as in Example 3, and the same evaluation was performed. When formed
The difference in transparency was evident.

Example 4 In place of 1.4 parts of anthranilic acid in Example 3, 1-amino-benzene-3,5-
10. Ethyl dicarboxylate (aromatic amine 11 in Table 1)
8 parts, 1-amino-2-trifluoromethylbenzene 1
Similarly, using 6.4 parts of 1-amino-4-chlorobenzene (aromatic amine 14 in Table 1) instead of 4.5 parts, 23.3 parts of diazotization reaction and 5-acetoacetylaminobenzimidazolone were performed. Was performed to obtain 128 parts (solid content: 32%) of an aqueous paste of a benzimidazolone yellow pigment i. It is dried and pulverized and used as a toner colorant.

Using the toner colorant (pigment i) thus obtained, toner base particles, a toner and a developer for developing an electrostatic image were obtained in the same manner as in Example 1, and the dispersion of the image and the pigment was similarly performed. When the state was evaluated, it was the same as in Example 1.

(Comparative example 4)
Amino-4-chlorobenzene (aromatic amine 1 in Table 1)
4) 123 parts (solid content: 30%) of pure benzimidazolone yellow pigment j aqueous paste j was obtained in the same manner as in Example 3 using only 12.8 parts. Also, 1-amino-
Benzene-3,5-dicarboxylic acid ethyl ester (Table 1)
Using only 23.7 parts of the aromatic amine 11), 155 parts (solid content 29%) of an aqueous paste of pure benzimidazolone yellow pigment k were obtained in the same manner. Instead of the aqueous paste of the pigment i, a total of 51 parts of the aqueous paste obtained by mixing 22.5 parts of the aqueous paste of the pigment j and 28.5 parts of the aqueous paste of the pigment k. The resulting amine has a composition substantially the same as that of the aqueous paste of the pigment i), and is dried and pulverized to obtain toner base particles for electrostatic image development, a toner and a developer in the same manner as in Example 4. As a result, when the image quality was significantly reduced, especially when an image was formed on an OHP sheet,
The difference in transparency was evident.

Example 5 8.8 parts of anthranilic acid (aromatic amine 9 in Table 1), 4.8 parts of 1-amino-2-trifluoromethylbenzene (aromatic amine 12 in Table 1)
2.5 parts of 1-amino-2-methoxybenzene (aromatic amine 25 in Table 1) and 31 parts of 35% hydrochloric acid were added to 200 ml of ice water.
Then, a solution prepared by dissolving 7.0 parts of sodium nitrite in 50 parts of water was added at 5 ° C. or lower and stirred for 1 hour to carry out a diazotization reaction to prepare a diazo liquid. On the other hand, ice water 150
0 part is 5-acetoacetylaminobenzimidazolone 2
3.3 parts and 16 parts of sodium hydroxide are dissolved by stirring at 10 ° C. or less, and 220 parts of a 12% aqueous acetic acid solution is added to 1 part of the solution.
With stirring at 0 ° C. or less, fine crystals of 5-acetoacetylaminobenzimidazolone were added at a stretch to precipitate fine crystals,
A slightly acidic coupler solution of about pH 5 was prepared. While stirring the coupler solution, the above diazo solution was added at 20 ° C. or less, stirred for 3 hours, further heated to 80 ° C., stirred for 1 hour, and then filtered and washed with water to obtain a desired benzimidazolone yellow pigment. 123 parts of an aqueous paste (solid content 3
0%). This is pulverized by drying and used as a colorant for toner (pigment 1).

Using the toner colorant (pigment 1) thus obtained, toner base particles, a toner and a developer for developing an electrostatic image were obtained in the same manner as in Example 1, and the dispersion of the image and the pigment was similarly performed. When the state was evaluated, it was the same as in Example 1.

(Comparative Example 5) Instead of the aqueous paste of the pigment 1, 16.4 parts of an aqueous paste of a benzimidazolone pigment b of Comparative Example 1, and an aqueous paste of 30.2 of a benzimidazolone pigment f of Comparative Example 2 And a total of 86.1 parts of an aqueous paste obtained by mixing 39.5 parts of the aqueous paste of the benzimidazolone pigment h of Comparative Example 3 (when the aqueous paste was mixed at this ratio, the ratio of the amine evaluated in mol was 1 having the same composition as the aqueous paste of Example 1) was dried and pulverized to obtain toner base particles for electrostatic image development, a toner and a developer in the same manner as in Example 5 and evaluated similarly. The difference in transparency was evident especially when an image was formed on the OHP sheet.

[0053]

By using a benzimidazolone pigment obtained by mixing two or more aromatic amines to carry out a diazotization reaction and then performing a coupling reaction with 5-acetoacetylaminobenzimidazolone. Toner mother particles, toner and developer for developing electrostatic images, which are sharp and have excellent color reproducibility and color developing properties, and which can form remarkably transparent images especially when images are formed on transparent substrates such as OHP sheets. was gotten. 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 (3)

[Claims] 1. A cup comprising two or more diazotized reactants obtained from an aromatic amine represented by the following general formula (1) and 5-acetoacetylaminobenzimidazolone represented by the following chemical formula (2): Toner base particles for electrostatic image development, comprising a benzimidazolone pigment obtained by a ring reaction. Embedded image (Where X and Y in the formula are each independently —H, -NO
_{^{2, -CONHR 1, -COOR 2,}} -CF 3, -C
N represents a halogen atom, an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, R ¹ represents -H, an alkyl group or an aryl group having 1 to 18 carbon atoms, and R ² represents-
H represents an alkyl group having 1 to 6 carbon atoms. ) 2. An electrostatic image developing toner comprising a mixture of the toner particle for electrostatic image development according to claim 1 and an external additive. 3. A developer comprising a mixture of the toner for developing an electrostatic charge image according to claim 2 and a carrier.