JPH11119461A - Toner mother grains, and toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electrostatic charge image developing toner mother grains obtained by dispersing a pigment in more minute state than in a conventional flashing method and capable of obtaining a sharp and sufficient color reproducibility and color developability, and to provide a toner and a developer both using the toner mother grains. SOLUTION: The electrostatic charge image developing toner mother grains contain a pigment and a binder resin and a pigment dispersing agent represented by the formula: P-[X-Y-Z-N(R<1> )R<2> ]N in which P is an organic dye residue or heterocyclic or aromatic polycyclic group; X is a divalent bonding group comprising 2-15 atoms selected from among S, C, N, O, and H; Y is a simple bond or -N(R)- or -O- group; R is H atom or a 1-18 C alkyl group or the like; Z is a 1-6 C alkylene group; each of R<1> and R<2> is a 1-18 C alkyl group or the like; and (n) is 1, 2, or 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-definition full-color image. For this reason, there is a strong demand for further improving the quality of full-color electrophotographic images.

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

In color image formation by full-color electrophotography, all colors are reproduced by using three color toners of three primary colors, magenta, cyan and yellow, and preferably four color blacks for inking. Things.
In this method, for example, light from a document is first subjected to analog or digital color separation and guided to a photoconductive layer of a photoreceptor to form an electrostatic latent image of the first color. Subsequently, the toner is held on a transfer material such as paper through a development and transfer process. Further, for the second and subsequent colors, the above-described steps are sequentially performed a plurality of times, and a plurality of color toners are superimposed on the same transfer material, and a final full-color image is obtained by one-time fixing.

The use of full-color copying machines, full-color printers, and the like to form full-color images on transparent substrates such as sheets for overhead projectors (hereinafter, abbreviated as OHP) has been increasing. As with the most common conventional black toner, the toner used for full-color image formation is required to have various characteristics, such as stable chargeability and good fluidity,
Transparency, sharpness, color reproducibility and the like are further required. That is, since a full-color image is obtained by superimposing a plurality of color toners on the material to be transferred as described above, if the light transmittance of each toner is insufficient, color reproducibility is deteriorated and a clear image is obtained. It is difficult to obtain an image. Especially OH
This phenomenon is remarkable when a full-color image is formed on a transparent substrate such as a sheet for P, and it is difficult to obtain a good transparent image.

As a countermeasure, it is conceivable to increase the degree of dispersion of the pigment, that is, to reduce the particle size of the pigment in the toner. Generally, as the particle size of the pigment is reduced to increase the degree of dispersion, the transparency of the pigment dispersion is improved. However, ordinary dispersing machines such as a sand mill, a three-roll mill, a ball mill, and an extruder mainly break down the secondary particles of the pigment (primary particles are weakly agglomerated) into primary particles. With the disperser described above, it is difficult to make the pigment finer. By using a high-speed sand mill or the like, it is possible to further refine the pigment depending on the kind of the pigment, but it requires a very large amount of energy.

[0007]

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

[0008]

In a first aspect of the present invention, there is provided an electrostatic image developing method comprising a pigment, a binder resin, and a pigment dispersant represented by the following general formula (1). These are toner base particles. 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 a 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, . )

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

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

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the pigment of the present invention, various organic pigments, inorganic pigments and mixtures thereof used in toners can be used. For example, phthalocyanine blue,
Phthalocyanine pigments such as phthalocyanine green, toluidine red, toluidine maroon, hansa yellow,
Insoluble azo pigments such as benzidine yellow and pyrazolone red, azo lake pigments, anthraquinone pigments, quinacridone red, quinacridone-based pigments such as quinacridone magenta, dioxazine pigments, diketopyrrolopyrrole pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, Examples include flavanthrone pigments, perinone pigments, perylene pigments such as perylene red and perylene scarlet, isoindolinone pigments, and thioindigo pigments.

Such a pigment may be used in the form of an aqueous slurry or a wet cake after the formation of the pigment, or the slurry may be powdered by drying such as spray drying. However, as described above, the smaller the dispersed particle size of the pigment in the toner for developing an electrostatic image is, when an image is formed, a clear and sufficient color reproducibility and color developability are obtained, so that the pigment is less likely to aggregate. In this respect, it is preferable to use undried ones. In addition, it is preferable to select a pigment that can be more easily refined in the dispersion step.

The preferred particle size of the pigment is 0.2 μm or less, more preferably 0.1 μm or less, as the average particle size by centrifugal sedimentation. With such a particle size, when an image is formed, clear and sufficient color reproducibility and color development can be obtained.

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

As the binder resin of the toner base particles of the present invention, conventionally known binder resins can be widely used, but colorless and transparent resins are more preferable in consideration of image transparency. For example, polystyrene, styrene- (meth) acrylonitrile copolymer, styrene- (meth) acrylamide copolymer, styrene-acrylate copolymer, styrene-butadiene copolymer, chloride resin, styrene-vinyl acetate copolymer , Rosin-modified maleic resin, phenolic resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin,
Examples include polyurethane resin, silicone resin, rosin / ester, and rosin. The production method of any resin is not particularly limited.

The pigment dispersant represented by the general formula (1) used in the toner base particles of the present invention disperses the pigment in the toner base particles more finely, and provides sharpness and color reproduction when an image is formed. And color development. 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 it is industrially advantageous to use a dye having a hue close to the pigment used.
Further, as the heterocyclic ring constituting the heterocyclic residue, for example,
Thiophene, furan, xanthene, pyrrole, imidazole, isoindolin, isoindolinone, benzimidazolone, indole, quinoline, carbazole, acridine, acridone, anthraquinone and the like. 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 of the present invention may be used in the form of a dry powder when the pigment is dispersed, or may be used by mixing with the pigment in advance. When using a solution dissolved or dispersed in a solvent or a mineral acid or organic acid aqueous solution, add it to the pigment water or solvent slurry and allow it to be adsorbed on the surface of the pigment. For pigments, quinacridone pigments, dioxazine pigments, etc., during the pigmentation process such as salt milling and sulfuric acid dissolution, add a powder or solution or dispersion of a pigment dispersant, adsorb it on the surface of the pigment, and filter it. May be used as a pigment composition obtained by a drying method.

The toner base particles of the present invention can be obtained in a conventional manner. That is, the pigment, the binder resin, the pigment dispersant represented by the general formula (1), and if necessary, other charge control agents and additives are added, and the mixture is preliminarily mixed with a Henschel mixer and then extruded. Is used for melt-kneading. Then, after cooling, coarsely pulverized with a hammer mill or the like,
Pulverize finely with a jet mill, classify with a wind classifier, etc.
What is necessary is just to obtain a classified product having a predetermined particle size distribution with an average particle size of about 5 to 20 μm.

As the charge control agent to be incorporated into the toner base particles of the present invention, any known charge control agent, both positively and negatively charged, 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.

[0023]

The present invention will be described in more detail with reference to the following examples. In the examples, parts and% indicate parts by weight and% by weight, respectively. In addition, the pigment dispersants a to
Table 1 shows typical examples of n.

[0024]

[Table 1]

[0025]

EXAMPLES Example 1 The following materials were premixed with a Henschel mixer and melt-kneaded with an extruder. Lionol Blue FG-7330 (pigment, manufactured by Toyo Ink Manufacturing Co., Ltd.) 2.8 parts Unsaturated polyester resin 97.0 parts Pigment dispersant a 0.2 part After cooling, coarsely pulverized using a hammer mill, and then jet milled. After pulverizing, the average particle size is 10.0 with an air classifier.
μm toner base particles are obtained. 0.4 parts of titanium oxide fine powder having an average particle diameter of 0.05 μm is added to 100 parts of the toner base particles, and mixed with a Henschel mixer to obtain a cyan toner.

Examples 2 to 4 Cyan toners were formed using compounds b to d according to Example 1.

Example 5 2.8 parts of Hosta Palm Pink E (manufactured by Hoechst) was used in place of Lionol Blue FG-7330 as a pigment, and 0.2 part of e was used in place of a as a pigment dispersant. Other than the above, in the same manner as in Example 1,
A toner base particle and a magenta toner are obtained.

Examples 6 to 8 Magenta toners were formed using compounds f to h according to Example 5.

Example 9 2.8 parts of Hansa Brilliant Yellow 5GX02 (manufactured by Hoechst) was used in place of Lionol Blue FG-7330 as a pigment, and 0.2 part of i was used in place of a as a pigment dispersant. Except for the above, toner base particles and a yellow toner are obtained in the same manner as in Example 1.

Example 10 Compound j according to Example 9
Was used to form a yellow toner.

EXAMPLE 11 Irgazine Yellow 2GL was used in place of Lionol Blue FG-7330 as a pigment.
Toner base particles and a yellow toner are obtained in the same manner as in Example 1, except that 2.8 parts of TE (manufactured by Ciba) and 0.2 parts of i are used instead of a as the pigment dispersant.

Example 12 A yellow toner was formed using Compound 1 in the same manner as in Example 11.

Example 13 Except that 2.8 parts of Monarch 800 (manufactured by Cabot) were used instead of Lionol Blue FG-7330 as a pigment and 0.2 parts of k instead of a as a pigment dispersant. In the same manner as in Example 1,
A toner base particle and a black toner are obtained.

Comparative Example 1 The following materials were premixed with a Henschel mixer and melt-kneaded with an extruder. Lionol Blue FG-7330 3.0 parts Unsaturated polyester resin 97.0 parts After cooling, coarsely pulverized using a hammer mill, finely pulverized with a jet mill, and then averaged with a pneumatic classifier to have an average particle size of 10.0.
μm toner base particles are obtained. 0 and 4 parts of titanium oxide fine powder having an average particle size of 0.05 μm are added to 100 parts of the toner base particles and mixed with a Henschel mixer to obtain a cyan toner.

Comparative Example 2 In the same manner as in Comparative Example 1, except that 3.0 parts of Hostaperm Pink E (manufactured by Hoechst) was used instead of Lionol Blue FG-7330 as a pigment, toner base particles and Obtain magenta toner.

Comparative Example 3 In the same manner as in Comparative Example 1, except that 3.0 parts of Hansa Brilliant Yellow 5GX02 (manufactured by Hoechst) was used instead of Lionol Blue FG-7330 as a pigment, toner base particles and Obtain yellow toner.

Comparative Example 4 Irgazine Yellow 2 GLT was used instead of Lionol Blue FG-7330 as a pigment.
A toner base particle and a yellow toner are obtained in the same manner as in Comparative Example 1, except that 3.0 parts of E (manufactured by Ciba) is used.

Comparative Example 5 Toner base particles and black toner were prepared in the same manner as in Comparative Example 1 except that 3.0 parts of Monarch 800 (manufactured by Cabot) was used instead of Lionol Blue FG-7330 as a pigment. Get.

6 parts of each of the toners for developing electrostatic images obtained in Examples 1 to 13 and Comparative Examples 1 to 5 were 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.). In each of the examples containing the pigment dispersant of the present invention, clear and sufficient color reproducibility and color development were obtained. Further, the obtained toner was melted by a hot press to form a uniform thin layer on a glass plate, and the dispersion state was observed with an optical microscope. On the other hand, each comparative example containing no pigment dispersant was unclear,
Sufficient color reproducibility and coloring were not obtained, and the difference from the examples was clear.

[0040]

As described above, according to the present invention, toner base particles for electrostatic image development, and a toner and a developer having a small particle diameter of the pigment in the toner, and providing clear and sufficient color reproducibility and color development can be obtained.

Claims (3)

[Claims] 1. A pigment, a binder resin, and the following general formula (1)
A toner base particle for developing an electrostatic image, comprising a pigment dispersant represented by the formula: 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 a 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, . ) 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.