JPH11237754A - Toner mother particles and toner and developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner mother particles and the toner and the developer using these toner mother particles capable of obtaining sharp and sufficient color reproduction performance and color development performance at the time of forming a full color image by using a full color copying machine or a printer or the like. SOLUTION: These electrostatic charge image developing toner mother particles composed essentially of a pigment and a binder resin are characterized by containing a pigment dispersant represented by the formula in which P is an organic dye residue or a heterocyclic group; X is a simple bond or a divalent bonding group composed of 1-50 C, N, O, and H atoms; Y is a -N(R<4> )-R<3> - or -O-R<3> - group; R<3> is 1-10C alkylene or phenylene group; R<4> is an H atom or a 1-18C alkyl group or the like; Z is a hydroxyl or 1-4C alkoxy group or the like.

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 an image is formed using magenta, cyan, yellow, and black toners, the toner base particles for developing an electrostatic image capable of obtaining clear and sufficient color reproducibility and color development, and the toner base particles are used. To a toner and a developer formed by the above method.

[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 the toners of a plurality of colors are superimposed on the same material to be transferred, 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 a transparent substrate such as a sheet for an overhead projector (hereinafter abbreviated as OHP) has been increasing. Today,
Toners used for full-color image formation are required to have various characteristics, for example, stable chargeability and good fluidity, as in the case of the most common conventional black toner,
Transparency, sharpness, color reproducibility and the like are further required.

That is, since a full-color image is obtained by superimposing a plurality of color toners on a transfer material as described above, if the light transmittance of each toner is insufficient, color reproducibility deteriorates. It is difficult to obtain a clear image. This phenomenon is particularly remarkable when a full-color image is formed on a transparent substrate such as an OHP sheet, and it is difficult to obtain a good transparent image.

As a countermeasure, it is conceivable to increase the degree of dispersion, 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 secondary particles of the pigment (primary particles are weakly agglomerated) into primary particles,
With these ordinary dispersing machines, 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.

[0008]

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

[0009]

According to the present invention, there is provided a toner base particle for developing an electrostatic image mainly comprising a pigment and a binder resin, comprising a pigment dispersant represented by the following general formula (1). The toner base particles for electrostatic image development are characterized in that:

General formula (1)

Embedded image(Where P is an organic dye residue or a heterocyclic residue, and X is
1 to 50 selected from a direct bond or S, C, N, O, H
From a chemically rational combination of atoms
A divalent linking group, Y is -N (R^Four) -R^Three-Or -O
-R^Three− (R^ThreeIs a substituted C 1-10
Alkylene group which may be substituted or which may be substituted
Phenylene group, R^FourIs H or alkyl having 1 to 18 carbons
Group or -R ^Three−N (R¹) R^TwoRepresents ), Z is a hydroxyl group
Or an alkoxy group having 1 to 4 carbon atoms or -YN (R¹)
R^TwoAnd R¹, R^TwoAre replaced independently
An alkyl group having 1 to 18 carbon atoms which may be
R¹, R^TwoAnd is optionally substituted with N, O or S
Represents an optionally substituted heterocyclic ring. )

According to a second aspect of the present invention, there is provided a method according to the first aspect, wherein the pigment dispersant represented by the general formula (1) is contained in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the pigment. These are toner base particles for charge image development.

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

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

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the pigment used in the present invention include various organic pigments and inorganic pigments used in toners, and mixtures thereof. For example, phthalocyanine-based pigments such as phthalocyanine blue and phthalocyanine green, insoluble azo pigments such as toluidine red, toluidine maroon, hanza yellow, 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, flavanthrone pigments, perinone pigments, perylene pigments such as perylene red and perylene scarlet, isoindolinone pigments, thioindigo pigments and the like. Can be done.

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, in the toner for developing an electrostatic image, the smaller the particle size of the pigment dispersed in the toner is, the more clear and sufficient color reproducibility and color forming properties can be obtained when an image is formed. It is preferable to make the particle size finer. Alternatively, it is preferable to select a pigment that can be miniaturized in the dispersion step.

In the case of the toner base particles of the present invention, in the case of black toner base particles, yellow, cyan and red are used.
A color processing pigment may be obtained, and these three processing pigments may be used as a colorant, or carbon black may be used. As the carbon black, all known ones such as channel black, furnace black and lamp black can be used.

The pigment dispersant represented by the general formula (1) used in the present invention facilitates dispersion of the pigment in the toner, makes the pigment particles finer, and provides clear and sufficient color reproducibility and color formation during image formation. So that sex is obtained. General formula (1)
Examples of the organic dye constituting the organic dye residue represented by P include phthalocyanine, insoluble azo, azo lake, anthraquinone, quinacridone, dioxazine, diketopyrrolopyrrole, anthrapyrimidine, anthanthrone, There are indanthrone type, flavanthrone type, perinone type, perylene type, thioindigo type 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. Examples of the heterocyclic ring constituting the heterocyclic residue include, for example, thiophene, furan, xanthene, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, indole, quinoline, carbazole, acridine, acridone, anthraquinone and the like. is there. When P is a heterocyclic ring, the pigment dispersant of the general formula (1)
There is versatility because it is possible to obtain something that is hardly colored,
It is also preferred for color toners.

X is selected from S, C, N, O and H;
A divalent linking group consisting of a chemically rational combination consisting of 15 atoms, for example, -SO ₂ -, -
_{C0 -, - CH 2 -,} - O -, - COO -, - NH- or a combination此are like, 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 with up to 18 carbon atoms. Further, in some cases, R ¹ and R ² are linked to further form N, O or S
May form a 5- or 6-membered heterocyclic ring.

Table 1 shows typical examples of the compound represented by the general formula (1).

[Table 1]

[0020]

Embedded image

[0021]

Embedded image

[0022]

Embedded image

The above-mentioned pigment dispersant may be used in the form of a dry powder when the pigment is dispersed in a binder resin during the production of a toner, or may be used in combination with a previously dried powder dispersant and a pigment. May be mixed and dispersed in a binder resin. In the case of using a solution dissolved or dispersed in a solvent or an aqueous solution of a mineral acid or an organic acid, a solution or dispersion of a pigment dispersant may be added to a slurry of water or a solvent of the pigment and adsorbed on the surface of the pigment. Alternatively, azo pigments among the pigments during coupling, phthalocyanine pigments, quinacridone pigments and dioxazine pigments, etc., during the pigmentation step such as the salt milling method and sulfuric acid dissolving method, etc. A pigment composition may be obtained by adding a solution or a dispersion, adsorbing a pigment dispersant on the surface of the pigment, filtering, and drying as necessary. Hereinafter, the pigment to which the pigment dispersant is added is referred to as a treated pigment.

In the present invention, the pigment dispersant represented by the general formula (1) is preferably contained in an amount of 0.01 to 30 parts by weight based on 100 parts by weight of the pigment.

The toner base particles of the present invention can be obtained according to a conventional method. The above-mentioned pigment, binder resin, and if necessary, other charge control agents and additives are added, and premixed by a Henschel mixer or the like. Thereafter, melt kneading is performed by an extruder or the like. Next, after cooling, it is coarsely pulverized by a hammer mill or the like and finely pulverized by a jet mill or the like. Thereafter, the particles are classified by an air classifier or the like to obtain a classified product having a predetermined particle size distribution with an average particle size of about 5 to 20 μm, that is, toner base particles.

The binder resin of the toner base particles of the present invention can be widely used, including known resins. In consideration of image transparency, a colorless and transparent resin is more preferable. For example, polystyrene, styrene-acrylate copolymer, styrene-butadiene copolymer, chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, low molecular weight polyethylene, Examples include molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, rosin ester, rosin and the like. The production method of any resin is not particularly limited.

It is also preferable to add a charge control agent to the toner base particles of the present invention. As the charge control agent, any of known positive and negative charges can be used. When the toner base particles are black, as a charge control agent, for example, a nigrosine dye, a triphenylmethane dye, a chromium-containing metal complex, a molybdate chelate pigment, a rhodamine dye,
Examples thereof include organometallic complexes such as alkoxy-based amines, quaternary ammonium salts, alkylamides, and metal complexes of alkyl-substituted salicylic acids (for example, chromium, aluminum, and zinc complexes of di-tert-butylsalicylic acid). Further, when the toner base particles are other than black, a colorless or light-colored charge control agent that 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 given.

A fluidity improver is added to the toner base particles of the present invention.
It is also preferable to add an external additive as a cleaning aid. 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, etc. It is preferable to add a fine powder of 50 μm, such as polytetrafluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, polystyrene, or silicone. It is also preferable to add an external additive obtained by variously surface-treating these mixtures and further, these fine powders.

The developer of the present invention is obtained by mixing the above-mentioned toner and carrier, and can be obtained by a conventionally known method, and is not particularly limited. As the carrier used for the developer according to the present invention, all known carriers can be used. In general, carriers constituting a two-component developer are roughly classified into conductive carriers and insulating carriers. Normally, oxidized or unoxidized iron powder is used as the conductive carrier. A typical example of the insulating carrier is a carrier in which the surface of a carrier core material particle generally made of a ferromagnetic material is uniformly coated with an insulating resin. Examples of the core material of the carrier include particles of iron oxide (magnetite), reduced iron, copper, ferrite, nickel, cobalt, and the like, and alloys of these and zinc, aluminum, and the like. Acrylic resin as coating resin,
Any of known materials such as an epoxy resin, a silicone resin, a urethane resin, a polyacetal resin, a polyamide resin, a polycarbonate resin, a phenol resin, a vinyl acetate resin, a cellulose resin, a polyolefin resin, a fluororesin, and an amino resin may be used. The carrier preferably has a particle size of about 20 to 200 μm. Generally, the developer preferably contains 1 to 30% of toner.

[0030]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. However, this does not limit the embodiment of the present invention at all. In Examples and Comparative Examples, parts and% indicate parts by weight and% by weight, respectively.

Example 1 Preparation of Magenta Toner Pigment (Brilliant Carmine 6B, manufactured by Toyo Ink Mfg. Co., Ltd.) 2.8 parts Polyester resin (manufactured by Mitsubishi Rayon) 97.0 parts Compound a in Table 1 (: Pigment dispersion 0.2 part of agent (C) Premix the above amounts with a Henschel mixer,
Melt and knead with a twin-screw extruder. After cooling, the mixture is roughly pulverized using a hammer mill, and then finely pulverized using a jet mill, and then toner base particles having an average particle diameter of 10.0 μm are obtained using an air classifier. 0.4 parts of titanium oxide fine powder is added to 100.0 parts of the toner base particles and mixed with a Henschel mixer to obtain a magenta toner.

Preparation of Cyan Toner Copper phthalocyanine (Lionol Blue F
G-7351, manufactured by Toyo Ink Mfg. Co., Ltd.), and a cyan toner is obtained in the same manner as in the preparation of the magenta toner, except that the compound b in Table 1 is used.

Preparation of Yellow Toner Disazo Yellow (Lionol Yellow G)
R, manufactured by Toyo Ink Mfg. Co., Ltd.), and a yellow toner is obtained in the same manner as in the preparation of the magenta toner except that compound c in Table 1 is used.

Preparation of Black Toner Carbon black (PRINTEX 70,
A black toner is obtained in the same manner as in the preparation of the magenta toner except that the compound d in Table 1 is used.

Preparation of Carrier 100.0 parts of ferrite particles having an average particle diameter of 50 μm are coated with 0.5 part of a straight silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd.) and baked at 120 ° C. for 4 hours to obtain a carrier.

The obtained toner was melted by a hot press to form a uniform thin layer on a glass plate, and the dispersion state of the pigment was observed with an optical microscope. It was confirmed that it was.

To 100 parts of the carrier, the toner 6
Each part was added, a developer was prepared, and image evaluation was performed using a commercially available full-color copying machine (CLC350, manufactured by Canon). The order of development and transfer of this copying machine is magenta, cyan, yellow, and black. In the full-color mode, a high-definition full-color image free from image defects such as fog and faithfully reproducing the original chart was obtained.

[Comparative Examples 1 to 4] Toners were prepared in the same steps as in Example 1 except that pigment dispersants a to d were not used and the same parts by weight were replaced with pigments.

Using these toners, a developer was prepared by the method described above, and a commercially available full-color copying machine (CLC35) was used.
0, manufactured by Canon Inc.) in the same manner as in Example 1. There was a decrease in image quality as compared with Example 1, and the difference in transparency was clear.

[0040]

As described above, according to the present invention, a toner and a developer for developing an electrostatic image, which have a small particle diameter of the pigment in the toner, and provide clear and sufficient color reproducibility and color developing property are obtained. When the dispersion state of the pigment in the toner was observed with a microscope, it was confirmed that the dispersion state was favorable without aggregation.

Claims (4)

[Claims] 1. An electrostatic image mainly comprising a pigment and a binder resin.
The toner base particles for development are represented by the following general formula (1).
Charge, characterized by containing a pigment dispersant
Toner base particles for image development. General formula (1)(Where P is an organic dye residue or a heterocyclic residue, X is
1 to 50 selected from a direct bond or S, C, N, O, H
From a chemically rational combination of atoms
A divalent linking group, Y is -N (R^Four) -R^Three-Or -O
-R^Three− (R^ThreeIs a substituted C 1-10
Alkylene group which may be substituted or which may be substituted
Phenylene group, R^FourIs H or alkyl having 1 to 18 carbons
Group or -R ^Three−N (R¹) R^TwoRepresents ), Z is a hydroxyl group
Or an alkoxy group having 1 to 4 carbon atoms or -YN (R¹)
R^TwoAnd R¹, R^TwoAre replaced independently
An alkyl group having 1 to 18 carbon atoms which may be
R¹, R^TwoAnd is optionally substituted with N, O or S
Represents an optionally substituted heterocyclic ring. ) 2. Formula (1) based on 100 parts by weight of pigment
2. The toner base particles for developing an electrostatic image according to claim 1, further comprising 0.01 to 30 parts by weight of a pigment dispersant represented by the formula: 3. An electrostatic image developing toner comprising a mixture of the toner particles for electrostatic image development according to claim 1 and an external additive. 4. A developer comprising a mixture of the toner for developing an electrostatic image according to claim 3 and a carrier.