JP3496473B2 - Toner base particles, and toner and developer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing toner mother particle used for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing and the like, and the toner mother particle. Relates to a developer formed by using. More specifically, the present invention relates to yellow toner mother particles for electrostatic image development, which can obtain clear and sufficient color reproducibility and color development when copying is performed, and a toner and a developer formed by using the toner mother particles. .

[0002]

2. Description of the Related Art In recent years, full-color images have been rapidly developed in copying machines, printers, etc., and their practical use has been greatly made. However, compared with photographs and printed materials, it is hard to say that the full-color electrophotographic images currently in practical use have reached a satisfactory image quality. Further, in recent years, with the advancement and development of computers and high-definition, there has been a strong demand for a method of forming a full-color image with higher definition. For this reason, there is a strong demand for higher quality full-color electrophotographic images.

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

In color image formation by full-color electrophotography, all three colors are reproduced by using three primary colors, magenta, cyan, and yellow, and preferably four black toners for black ink. It is a thing.
In the method, for example, first, light from an original is color-separated in an analog or digital manner and guided to a photoconductive layer of a photoconductor to form a first-color electrostatic latent image. 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, toners of a plurality of colors are superposed on the same recording medium, and the final full-color image is obtained by fixing once.

Nowadays, it has been increasing to form a full color image on a transparent substrate such as a sheet for an over head projector (hereinafter abbreviated as OHP) using a full color copying machine or a full color printer. The toner used for full-color image formation is required to have various characteristics, for example, stable chargeability and good fluidity, as in the case of the most general black toner in the past.
Further, transparency, sharpness, color reproducibility, etc. are required. That is, since a full-color image is obtained by superimposing a plurality of color toners on the recording medium as described above, if the light transmittance of each toner is insufficient, the color reproducibility is deteriorated and a clear image is obtained. It becomes difficult to obtain an image. Especially O
This phenomenon is remarkable when a full-color image is formed on a transparent substrate such as a HP sheet, and it is difficult to obtain a good transparent image.

As a countermeasure, it is possible to increase the degree of dispersion of the pigment, that is, to reduce the particle size of the pigment in the toner. Generally, the transparency of a pigment dispersion is improved by decreasing the particle size of the pigment and increasing the dispersity. However, ordinary dispersers such as sand mills, three-roll mills, ball mills, and extruders mainly break secondary particles of pigment (primary particles are weakly agglomerated) into primary particles. It is difficult to make the pigment finer with this disperser. By using a high speed sand mill or the like, it is possible to further miniaturize 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 put into cold water to precipitate the pigment as fine particles. However, since the pigment finely divided by this method causes strong secondary aggregation when dried, it is very difficult to redisperse the dried pigment to the primary particles. Heat treatment in a solvent such as alcohol is known as a method for improving dispersibility, but it is not desirable because it causes crystal growth and increases the pigment particle size.

Further, as a method for making the primary particles of the pigment finer, a mixture of the pigment and a water-soluble inorganic salt such as salt or sodium sulfate is moistened with a small amount of a solvent such as polyethylene glycol, and the mixture is rubbed with a strong force such as a kneader. After crushing, there is a method in which an inorganic salt and a solvent are washed off with water and dried to obtain a fine pigment having 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 washing and drainage water, resulting in a high production cost.

[0009]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned conventional methods, and when an image is formed by using a copying machine, a printer or the like, it is clear and has sufficient color reproducibility and color developability. It is an object of the present invention to provide toner core particles for developing an electrostatic image, a toner, and a developer, which are obtained.

[0010]

[Means for Solving the Problems]

A first aspect of the present invention is to provide two or more kinds of diazotized reaction products obtained from an aromatic amine represented by the following general formula (1) and 5-acetoacetylaminobenzimidazo represented by the following chemical formula (2). Aqueous paste of benzimidazolone pigment (A) obtained by coupling reaction with ron
And a resin (B) that is solid at room temperature are heated and kneaded, and then a resin-coated pigment (C) obtained by removing water and a binder resin (D) are heated and kneaded. Toner mother particles for charge image development.

[0012]

[Chemical 3]

(However, X and Y in the formula are independent of each other,
^{_{-H, -NO 2, -CONHR 1,}} -COOR 2, -C
F _3, represents -CN, halogen atom, an alkyl group or an alkoxy group having 1 to 18 carbon atoms having 1 to 6 carbon atoms, R ¹ is -
H represents an alkyl group having 1 to 18 carbon atoms or an aryl group, and R ² represents -H or an alkyl group having 1 to 6 carbon atoms. In the general formula (1), the halogen atom is a fluorine atom, a chlorine atom, a bromine atom or the like, and the alkyl group is a methyl group, an ethyl group, a butyl group, an isopropyl group, a hexyl group or the like, and an alkoxy group. Is a methoxy group, an ethoxy group, a butoxy group, a stearyloxy group, an oleyloxy group or the like, and R ¹ is the above alkyl group,
Examples of R ² such as a phenyl group, a tolyl group, and an ethylphenyl group may include the above-mentioned alkyl groups and the like, but are not limited to these substituents.

[0014]

[Chemical 4]

A second invention is a toner for developing an electrostatic charge image, which is characterized in that the toner mother particles for developing an electrostatic charge image according to the first invention are mixed with an external additive.

A third invention is a developer comprising the toner for developing an electrostatic charge image according to the second invention and a carrier, which are mixed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The benzimidazolone pigment used in the present invention has an extremely clear hue from bluish yellow to reddish yellow, and is used as a colorant for toner mother particles for electrostatic image development. It 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 arbitrarily selected. Is mixed, preferably different aromatic amines are mixed at a ratio of 1 mol% or more with respect to the total number of moles of the aromatic amine to be used, and the diazotization reaction is carried out by a conventional method, and then 5-acetoacetylaminobenz It can be produced by a coupling reaction with imidazolone, and two or more kinds of compound molecules of the general formula (3) form crystal particles of a pigment.

[0018]

[Table 1]

[0019]

[Chemical 5]

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

The coupling reaction proceeds smoothly under both acidic and alkaline conditions, preferably pH 3 to
A clear pigment can be obtained by carrying out pH adjustment to pH 9 with hydrochloric acid or sodium hydroxide aqueous solution. After the coupling reaction, it is filtered and washed with water to neutrality, and an aqueous paste (A)
To get

In the coupling reaction, various surfactants such as nonionic, cation, anionic and amphoteric ions, various water-soluble resins such as rosin, various organic solvents such as butyl acetate, xylene and isobutyl alcohol are used. In addition, when the surface treatment of the pigment is performed, aggregation can be prevented and dispersion becomes easy. When the surface treatment is performed with rosin, after the coupling reaction is completed, the reaction solution is made alkaline and various rosin sodium aqueous solutions are added, and calcium chloride or barium chloride is further added to form an insoluble rosin salt to coat the pigment surface. . Instead of adding calcium chloride or barium chloride, the surface of the pigment may be acidified with mineral acid or the like and the surface of the pigment may be coated with rosin. As the rosin, gum rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleated rosin, fumarized rosin, wood rosin and the like can be used.

The above-mentioned production method is characterized in that two or more kinds of aromatic amines are mixed at an arbitrary ratio to carry out a diazotization reaction to perform a coupling reaction. The benzimidazolone pigment obtained by this method is , 2 with different chemical structures
A mixture of more than one kind of compound, and such a mixture is a mixture of pure pigments obtained by individually diazotizing an aromatic amine and then subjecting each to a coupling reaction, and a particle size, shape, Physical properties such as surface area and crystallinity are completely different. This difference in properties is brought about by the random arrangement of molecules having different chemical structures in the crystal structure. Compared with a pure benzimidazolone type pigment obtained by subjecting one kind of aromatic amine to a diazotization reaction and mixing reaction without mixing, the primary particles of the pigment are remarkably small and therefore the surface area is remarkably large. .

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

[0025]

[Chemical 6]

(In the formula, A is CO, SO ₂ , CH ₂
A linking group such as NHCOCH ₂ , B is an alkyl group, and n is an integer. ) Dispersing aids such as pigment derivatives are excellent in dispersing pigments and have a great effect of preventing reaggregation of pigments after dispersion. Therefore, by using pigment derivatives or the like, the above-mentioned benzimidazo of extremely fine particles can be obtained. It is possible to produce toner base particles for developing an electrostatic charge image which can bring out the characteristics of the Ron-based pigment to the maximum and can form an image that is clear and has excellent color reproducibility and color development. Further, these derivatives may be added when the above-mentioned benzimidazolone pigment is dispersed in the toner mother particles, but when the above-mentioned benzimidazolone pigment is produced, aromatic compounds shown in Table 1 are used. It is also possible to mix an amine and an aromatic amine of the following general formulas (6) and (7) and simultaneously carry out a diazotization reaction and then a coupling reaction.

[0027]

[Chemical 7]

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

As the colorant of the toner mother particles for developing an electrostatic image, the finer the primary particles of the pigment used, the more preferable. However, since the pigment generally has the property of aggregating when dried, it is obtained as described above. In order to utilize the fine state of the pigment in the aqueous paste of benzimidazolone-based pigment (A) as it is for toner mother particles, heating the resin (B) which is solid at room temperature without drying the aqueous paste (A) After kneading, the water content is removed and the resin (B) is coated to obtain a resin-coated pigment (C) in which pigment agglomeration is prevented (this step is referred to as flushing hereinafter), and the resin-coated pigment (C) is combined with the resin-coated pigment (C). It is important in the present invention that the resin composition (D) is kneaded by heating.

The flushing process will be described below. As the resin (B) that is solid at room temperature, that is, as the resin that can be used for flushing, any known resin that is solid at room temperature can be widely used. A colorless transparent resin is more preferable in consideration of the transparency of an image. For example, polystyrene, styrene-acrylic acid ester copolymer,
Styrene-butadiene copolymer, chlorinated resin, styrene-
Vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, rosin
Examples thereof include esters and rosins. These resins can also be used for dilution after flushing and melt kneading.

The resin-coated pigment (C) in the present invention can be obtained, for example, as follows. To the aqueous paste (A) of the benzimidazolone-based pigment obtained as described above, a resin (B) which is solid at room temperature and, if necessary, other various additives are added, and a mixing and dispersing machine such as a kneader or a super mixer. And mix and stir. At this time, you may heat as needed. The pigment content is transferred to the resin in about 10 to 20 minutes. The separated water is removed by decantation, and the remaining kneaded product is heated, if necessary, using two or three rolls to remove the water, and the resin-coated pigment (C) (pigment high concentration chip ).

The toner mother particles of the present invention can be obtained by a conventional method. That is, the binder resin (D) and, if necessary, other charge control agents and additives are added to the above resin-coated pigment (C), premixed with a Henschel mixer, and then melted using an extruder or the like. Knead. Then, after cooling, coarsely pulverize with a hammer mill or the like, finely pulverize with a jet mill or the like, and classify with an air classifier or the like to obtain an average particle size of 5 to 20.
It is sufficient to obtain a classified product having a predetermined particle size distribution of about μm.

As the binder resin (D), that is, a resin that can be used for melt-kneading after flushing, known resins can be widely used. A colorless transparent resin is more preferable in consideration of the transparency of an image. The same type of resin as the solid resin (B) at room temperature can be used, but it is not always the binder resin (D).
Does not have to match the resin (B).

It is also preferable to add a charge control agent to the toner mother particles of the present invention. As the charge control agent, all known charge control agents can be used, but colorless or light color agents that do not affect the color tone of the toner are preferable. For example, an organometallic complex such as a metal complex of alkyl-substituted salicylic acid (for example, a chromium complex, an aluminum complex, a zinc complex, or the like of ditertiarybutyl salicylic acid) can be used.

It is also preferable to add various particles as an external additive to the toner mother particles of the present invention as a fluidity improver, a cleaning aid and the like. All known external additives can be used. For example, 0.01 to 0.5 μm silica, alumina, metal oxides such as titanium oxide, abrasives such as silicon carbide and tungsten carbide, zinc stearate,
Lubricants such as fatty acid metal salts such as aluminum stearate,
In addition, it is preferable to add fine powder of 1 to 50 μm such as polytetrafluoroethylene, polyvinylidene fluoride, polymethacrylate, polystyrene and silicone. It is also suitable to add a mixture of these, and further an external additive obtained by subjecting these fine powders to various surface treatments.

The developer of the present invention is a mixture of the above-mentioned toner and carrier, can be obtained by a conventionally known method, and is not particularly limited. As the carrier used for the developer of the present invention, all known carriers can be used. Generally, the carriers that constitute the two-component developer are roughly classified into conductive carriers and insulating carriers.
As the conductive carrier, oxidized or unacidified iron powder or the like is usually used. A typical example of the insulating carrier is a carrier obtained by uniformly coating the surface of carrier core material particles made of a ferromagnetic material with an insulating resin. Examples of the core material of the carrier include iron oxide (magnetite),
Examples thereof include particles of reduced iron, copper, ferrite, nickel, cobalt and the like, and particles of alloys of these with zinc, aluminum and the like. Examples of the coating resin include acrylic resins, epoxy resins, silicone resins, urethane resins, polyacetal resins, polyamide resins, polycarbonate resins, phenol resins, vinyl acetate resins, cellulose resins, polyolefin resins, fluororesins, amino resins, and other known materials. Either may be used. 20 to 2 as a carrier
The size is preferably about 00 μm. In general, it is preferable that the developer contains 1 to 30% by weight of toner.

[0037]

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

Example 1 6.2 parts of 1-amino-2-methoxybenzene (aromatic amine 25 in Table 1), 1-amino-4-nitrobenzene (aromatic amine 3 in Table 1) 6.
9 parts and 31 parts of 35% hydrochloric acid were added to 200 parts of ice water, and then a solution of 7.0 parts of sodium nitrite dissolved in 50 parts of water was added at 5 ° C. or below and stirred for 1 hour to carry out a diazotization reaction to obtain a diazo solution. Was prepared. On the other hand, 23.3 parts of 5-acetoacetylaminobenzimidazolone and 16 parts of sodium hydroxide were dissolved in 1000 parts of ice water by stirring at 10 ° C. or lower, and 220 parts of 12% acetic acid aqueous solution was stirred at 10 ° C. or lower in this solution. While adding thereto, fine crystals of 5-acetoacetylaminobenzimidazolone were precipitated to prepare a weakly acidic coupler solution having a pH of about 5. While stirring this coupler solution, the above diazo solution was added at 20 ° C. or lower and stirred for 3 hours, further heated to 70 ° C. and stirred for 1 hour, and then filtered and washed with water to obtain the desired benzimidazolone-based yellow pigment a. 123 parts (solid content 30%) of the aqueous paste of was obtained.

Aqueous paste of pigment a (30% solid content product) 120.0 parts Unsaturated polyester resin (: room temperature solid resin (B)) 18.0 parts Methanol 0.4 parts Stainless steel 1 gallon kneader (Inoue Seisakusho Co., Ltd.) and mixed while heating at 100 ° C., and the pigment component transferred to the resin (flushing) in about 10 minutes. After removing the separated water and solvent from the kneader,
The remaining kneaded product was passed through a heating type two-roll five times to obtain a high-concentration pigment chip (resin-coated pigment).

Next, unsaturated polyester resin (: binder resin (D)) 100.0 parts The above pigment high concentration chip 5.0 parts Negative charge control agent 4.0 parts The above raw materials are melt-kneaded in an extruder. After cooling, coarse pulverization is performed with a hammer mill and fine pulverization with a jet mill, and toner mother particles having an average particle size of 10.0 μm are obtained using an air classifier. To 100.0 parts of the obtained toner mother particles, 0.4 parts 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.

An image was obtained using this developer with a commercially available full-color copying machine (CLC350, manufactured by Canon). As a result, the image was clear and had excellent color reproducibility and color development. The obtained toner was melted by hot pressing to form a uniform thin layer on the glass plate, and the dispersion state of the pigment was observed with an optical microscope to find that it was in a very good dispersion state without aggregation. Was confirmed.

(Comparative example 1)
129 parts of an aqueous paste of pure benzimidazolone-based yellow pigment b in the same manner as in Example 1 above, using only 12.3 parts of 1-amino-2-methoxybenzene without mixing with -amino-4-nitrobenzene. (Solid content 28%) was obtained. Also, pure benzimidazolone-based yellow pigment c water was prepared in the same manner as in Example 1 above, except that 13.8 parts of 1-amino-4-nitrobenzene was used without mixing 1-amino-2-methoxybenzene. 123 parts of cake (31% of solid content) were obtained. Instead of the aqueous paste of pigment a, 63.6 parts of the aqueous paste of pigment b and 58.6 parts of the aqueous paste of pigment c were mixed to obtain a total of 122.2 parts of the aqueous paste (having substantially the same composition as the aqueous paste of pigment a). )Using,
After the flushing, in the same manner as in Example 1, yellow toner mother particles for developing an electrostatic image, a toner and a developer were formed.
Further, when an image was obtained using a commercially available full-color copying machine (CLC350, manufactured by Canon) using this developer in the same manner as in Example 1, the image quality was deteriorated. Especially, when the image was formed on the OHP sheet, the transparency was improved. The difference was clear.

(Example 2) 1-amino-2-of Example 1
1-amino-2 instead of 6.2 parts of methoxybenzene,
5-dichlorobenzene (aromatic amine 15 in Table 1) 4.
9 parts, 11.3 parts of 1-amino-2-trifluoromethylbenzene (aromatic amine 12 in Table 1) was used instead of 6.9 parts of 1-amino-4-nitrobenzene. Aqueous paste 160 of benzimidazolone-based yellow pigment d was obtained by performing a coupling reaction with 23.3 parts of 5-acetoacetylaminobenzimidazolone.
Parts (solid content 25%) were obtained.

Using 144 parts of the aqueous paste of pigment d in place of the aqueous paste of pigment a of Example 1, toner mother particles for electrostatic image development, toner and developer were obtained in the same manner as in Example 1. Similarly, when the dispersed state of the image and the pigment was evaluated, it was the same as in Example 1.

(Comparative Example 2) In the above-mentioned Example 2, 1-
Aqueous pure benzimidazolone yellow pigment e in the same manner as in Example 1 except that 16.2 parts of 1-amino-2,5-dichlorobenzene were used without mixing with amino-2-trifluoromethylbenzene. 148 parts (27% solids) of paste were obtained. In addition, without mixing 1-amino-2,5-dichlorobenzene, only 16.1 parts of 1-amino-2-trifluoromethylbenzene was used in the same manner to prepare a pure aqueous benzimidazole yellow pigment f. 160 parts (solid content 25%) of paste were obtained. Instead of the aqueous paste of pigment a, a total of 140.7 parts of an aqueous paste obtained by mixing 40.9 parts of the aqueous paste of pigment e and 99.8 parts of the aqueous paste of pigment f (substantially the same composition as pigment d)
After the flushing, yellow mother particles for developing an electrostatic image, toner and developer were obtained in the same manner as in Example 1 and evaluated in the same manner.
The difference in transparency was apparent when the image was formed on the working sheet.

(Example 3) 1.4 parts of anthranilic acid (aromatic amine 9 of Table 1), 14.5 parts of 1-amino-2-trifluoromethylbenzene (aromatic amine 12 of Table 1) and 35% Hydrochloric acid (31 parts) was added to ice water (300 parts), and then a solution of sodium nitrite (7.0 parts) dissolved in water (50 parts) was added.
The mixture was added at a temperature of not higher than 0 ° 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 were dissolved in 1500 parts of ice water by stirring at 10 ° C or lower, and 220 parts of 12% acetic acid aqueous solution was stirred at 10 ° C or lower in this solution. While adding it all at once, fine crystals of 5-acetoacetylaminobenzimidazolone were precipitated to prepare a weakly acidic coupler solution having a pH of about 5. While stirring this coupler solution, the above diazo solution was added at 20 ° C. or lower and stirred for 3 hours, further heated to 80 ° C. and stirred for 1 hour, then filtered, washed with water and dried at 80 ° C. to obtain the desired benz. 133 parts aqueous paste of g of imidazolone type yellow pigment (solid content 30%)
Got

120. of the aqueous paste of pigment g obtained.
When 0 part was used in the same manner as in Example 1, toner mother particles for electrostatic image development, a toner and a developer were obtained, and the dispersed state of the image and the pigment was evaluated in the same manner.

(Comparative Example 3) 1 was obtained by the method of synthesizing the above pigment g.
127 parts of an aqueous paste of pure benzimidazolone-based yellow pigment h (solids content) in the same manner as in Example 3 above, using 13.7 parts of anthranilic acid without mixing with amino-2-trifluoromethylbenzene. 30%) was obtained.
Instead of the aqueous paste of pigment g, 11.5 parts of the aqueous paste of pigment h and the aqueous paste of pigment f of Comparative Example 2 13
A total of 141.7 parts of an aqueous paste (having substantially the same composition as the pigment g) mixed with 0.2 parts was used to prepare toner mother particles for electrostatic charge image development, a toner and a developer in the same manner as in Example 3. When obtained and evaluated in the same manner, the image quality was remarkably deteriorated, and when the image was formed on the OHP sheet, the difference in transparency was obvious.

Example 4 Instead of 1.4 parts of anthranilic acid of Example 3, 1-amino-benzene-3,5-
Ethyl dicarboxylate (aromatic amine 11 in Table 1) 11.
8 parts, 1-amino-2-trifluoromethylbenzene 1
Using 1-amino-4-chlorobenzene (aromatic amine 14 in Table 1) 6.4 parts instead of 4.5 parts, the same diazotization reaction and 5-acetoacetylaminobenzimidazolone 23.3 parts Was subjected to a coupling reaction with to obtain 128 parts (solid content: 32%) of an aqueous paste of benzimidazolone series yellow pigment i.

Then, an electrostatic charge image was prepared in the same manner as in Example 1 except that an aqueous paste of pigment i (32% solid content product) 166.0 parts unsaturated polyester resin 25.0 parts methanol 0.5 parts was used. The toner mother particles for development, the toner and the developer were obtained, and the dispersion state of the image and the pigment was evaluated in the same manner.

(Comparative Example 4) In the above-mentioned Example 3, 1-
Aqueous pure benzimidazolone yellow pigment j in the same manner as in Example 3 except that 12.8 parts of 1-amino-4-chlorobenzene was used without mixing ethyl amino-benzene-3,5-dicarboxylate. 123 parts of paste (30% of solid content) were obtained. Also, without mixing 1-amino-4-chlorobenzene, only 23.7 parts of 1-amino-benzene-3,5-dicarboxylic acid ethyl ester was used in the same manner to obtain pure benzimidazole type yellow pigment k. 155 parts of aqueous paste (29% solids) were obtained. Instead of the aqueous paste of pigment i, 79.7 parts of the aqueous paste of pigment j and 100.7 parts of the aqueous paste of pigment k were mixed to give a total of 1
Using 80.4 parts of the aqueous paste (having almost the same composition as the pigment i), toner mother particles for electrostatic image development, a toner and a developer were obtained in the same manner as in Example 4 and evaluated in the same manner. The image quality deteriorated, and when the image was formed on the OHP sheet, the difference in transparency was obvious.

(Example 5) 8.8 parts of anthranilic acid (aromatic amine 9 of Table 1), 1-amino-2-trifluoromethylbenzene (aromatic amine 12 of Table 1) 4.8 parts,
2.5 parts of 1-amino-2-methoxybenzene (aromatic amine 25 of Table 1) and 31 parts of 35% hydrochloric acid were added to 200 parts of ice water.
A solution of 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 solution. On the other hand, ice water 150
5-acetoacetylaminobenzimidazolone 2 in 0 parts
3.3 parts and 16 parts of sodium hydroxide were dissolved by stirring at 10 ° C. or below, and 220 parts of 12% acetic acid aqueous solution was added to 1 part of this solution.
While stirring at 0 ° C. or lower, added at once to precipitate fine crystals of 5-acetoacetylaminobenzimidazolone,
A weakly acidic coupler solution having a pH of about 5 was prepared. While stirring this coupler solution, the above diazo solution was added at 20 ° C. or lower and stirred for 3 hours, further heated to 80 ° C. and stirred for 1 hour, and then filtered and washed with water to obtain the desired benzimidazolone-based yellow pigment 1. 123 parts of aqueous paste (solid content 30
%) Was obtained.

Using 120 parts of the obtained pigment l aqueous paste, toner mother particles for electrostatic image development, a toner and a developer were obtained in the same manner as in Example 1, and similarly the dispersion state of the image and the pigment was evaluated. However, it was similar to Example 1.

(Comparative Example 5) Instead of the aqueous paste of pigment l, 24.6 parts of the aqueous paste of benzimidazolone pigment b of Comparative Example 1 and the aqueous paste of benzimidazolone pigment f of Comparative Example 2 45. Example 5 using 4 parts and 59.3 parts of an aqueous paste of the benzimidazolone pigment h of Comparative Example 3 and a total of 129.3 parts of the aqueous paste (having substantially the same composition as Pigment 1) were used. In the same manner as described above, toner base particles for developing an electrostatic image, a toner and a developer were obtained and evaluated in the same manner, the image quality was remarkably deteriorated, and especially when an image was formed on an OHP sheet, a difference in transparency was obvious. Met.

[0055]

EFFECT OF THE INVENTION By using a benzimidazolone pigment obtained by mixing two or more kinds of 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 an electrostatic charge image, which are clear and have excellent color reproducibility and color development, and can form a remarkably transparent image when an image is formed on a transparent substrate such as an OHP sheet. 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.

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Claims (3)

(57) [Claims] 1. A cup of two or more diazotized reaction products obtained from an aromatic amine represented by the following general formula (1) and 5-acetoacetylaminobenzimidazolone represented by the following chemical formula (2). A resin-coated pigment (C) obtained by heat-kneading an aqueous paste (A) of a benzimidazolone-based pigment obtained by ring reaction and a resin (B) solid at room temperature, and then removing water, and a binder resin. Toner mother particles for developing an electrostatic charge image, which are obtained by heating and kneading (D). [Chemical 1] (However, X and Y in the formula are independently -H, -NO.
_{^{2, -CONHR 1, -COOR 2,}} -CF 3, -C
N, 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 having 1 to 18 carbon atoms or an aryl group, and R ² represents-.
H or an alkyl group having 1 to 6 carbon atoms is represented. ) [Chemical 2] 2. An electrostatic charge image developing toner comprising a mixture of the electrostatic charge image developing toner mother particles 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.