JP2002317126A - Surface-treated pigment and dispersion thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent pigment excellent in initial dispersibility and a long-term dispersibility in water or an organic solvent and hardly causing aggregation of pigment particles, and to provide a method for manufacturing a surface-treated pigment improved in dispersibility. SOLUTION: The surface-treated pigment is obtained by causing an organic pigment particle to adsorb on the surface thereof a mixture deposited into water from a strong acid solution of a hardly water-soluble compound having an acidic functional group bonded to a coloring material portion and a compound which is a constituent of the organic pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a surface-treated pigment and a dispersion thereof.

[0002]

2. Description of the Related Art Conventionally, pigments are hardly soluble or insoluble in water or organic solvents. Therefore, when used in coloring image forming materials such as inks, paints, plastic colorants, liquid developers, etc. It is used by dispersing it in a medium such as an organic solvent or a resin. In order to efficiently disperse the pigment in the medium, it is adsorbed on the surface of the pigment by using a dispersant such as a surfactant, a synthetic resin, and a pigment derivative to improve the coatability on the medium and at the same time dispersibility of the pigment itself Has been improved.

However, in a pigment dispersion obtained by a pigment surface treatment method using a dispersant such as a surfactant or a synthetic resin, the dispersant adsorbed on the pigment surface and the unadsorbed dispersant are mixed in an equilibrium state. Therefore, if an additive is added to the dispersion at the time of ink formation, it is easily affected by the type of additive used, and a problem such as a decrease in dispersibility due to aggregation of the pigment occurs. Among them, a dispersant having a pigment skeleton similar to the pigment to be dispersed in the molecule, such as a pigment derivative, has a higher adsorptivity to the pigment surface than a dispersant such as a surfactant or a synthetic resin. It is hardly affected by additives sometimes added.

Until now, JP-A-8-218014, JP-A-9-151344 and JP-A-11-111344 have disclosed a method of manufacturing a semiconductor device.
No. 49974 discloses a technique of adsorbing a pigment derivative or a dye component on the surface of a pigment to disperse the pigment.
However, pigment derivatives or dye components having a large number of hydrophilic groups such as sulfonic acid groups and carboxylic acid groups in one molecule,
Since the solubility or affinity for water is too large compared to the affinity of the pigment for the particle surface, problems such as color mixing and bleeding occur when the ink is formed.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a surface-treated pigment which is excellent in initial dispersibility and long-term dispersibility in water and an organic solvent, and which hardly causes aggregation of pigment particles.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a mixture of a compound which is hardly soluble in water having an acidic functional group bonded to a dye portion and a compound which is a component of an organic pigment, and which is precipitated in water from a strong acid solution. The present invention relates to a surface-treated pigment characterized in that the pigment is adsorbed on the surface of particles. Further, the present invention provides a method wherein the compound as a component of the organic pigment is 3 to 7 based on the mixture.
0% by weight. Furthermore, the present invention
The present invention relates to a surface-treated pigment wherein the acidic functional group is -SO3H or a salt thereof. Further, the present invention provides an organic pigment 100 parts by weight,
And a surface-treated pigment comprising 1 to 50 parts by weight of a mixture precipitated in water from a strong acid solution of a compound having poor solubility in water having an acidic functional group bonded to a dye portion and a compound as a component of an organic pigment. Further, the present invention relates to a pigment dispersion obtained by dispersing the above-mentioned surface-treated pigment in a vehicle. Furthermore, the present invention relates to the above pigment dispersion, wherein the vehicle is an aqueous medium.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The organic pigments usable in the present invention include, for example, azo pigments such as diketopyrrolopyrrole pigments, soluble and insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, quinacridone pigments, Indolinone pigments, isoindoline pigments, quinophthalone pigments, perylene / perinone pigments, dioxazine pigments,
Anthraquinone pigments, dianthraquinonyl pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, pyranthrone pigments, vat dye pigments and basic dye pigments, etc. be able to.

The organic pigment usually has a primary particle size of 50,000 to 5
Although it is obtained as 0 nm, when the particle size of the organic pigment is relatively large, it is preferable to carry out wet pulverization such as salt milling or solvent milling or dry pulverization in order to make finer and control the particle diameter.

In the present invention, the mixture adsorbed on the surface of the pigment particles preferably contains 3 to 70% by weight of a compound having the same chemical structure as the organic pigment to be treated. By using a compound that is a component of the organic pigment, the solubility of the mixture in water is reduced, and at the same time, the adsorptive power to the pigment surface is increased. This mixture has a dispersed particle size that is about the same size or smaller than the pigment to be treated, and is not a single compound with high crystallinity such as a pigment, but a crystalline compound in which several compounds are mixed at the molecular level. Low or amorphous particles. The mixture of the present invention, by containing a compound that is a component of the organic pigment,
At the same time as efficiently adsorbing at high density on the pigment particle surface,
It suppresses the crystal growth of the mixture due to external stimuli caused by a change in temperature or a change in the dispersion medium. When the amount of the compound which is a component of the organic pigment in the mixture is reduced, the solubility of the mixture in water is increased, and crystal precipitation and crystal growth are easily caused by a change in temperature, and the particle size is much larger than that of the pigment to be subjected to the treatment. Not only does it become difficult to adsorb to the pigment particle surface, but it also tends to settle itself in water, thereby deteriorating the pigment dispersion efficiency during treatment.

In the present invention, the compound having a chemical structure in which an acidic functional group is bonded to the dye moiety is preferably hardly soluble in water, and has a solubility of 0.2% by weight or less. The lower the value, the higher the dispersion stability of the dispersion of the surface-treated pigment.

In the present invention, the acidic functional group of the water-insoluble compound having an acidic functional group bonded to the dye moiety includes -S
O3H or a salt thereof, -COOH or a salt thereof,-
SO2NHCH2SO3H or a salt thereof, -SO2N
H (CH2) 2SO3H or a salt thereof, -SO2NH
(CH2) 3SO3H or a salt thereof, -SO2NHC
6H4SO3H or a salt thereof, -CH2NHCOCH
2NHCH2SO3H or a salt thereof, -CH2NHC
OCH2NH (CH2) 2SO3H or a salt thereof,
CH2NHCOCH2NH (CH2) 3SO3H or a salt thereof, -CH2NHCOCH2NHC6H4SO3
H or a salt thereof, -CONHCH2SO3H or a salt thereof, -CONH (CH2) 2SO3H or a salt thereof, -CONH (CH2) 3SO3H or a salt thereof,
-CONHC6H4SO3H or a salt thereof, -SO2
NH (CH2) 4COOH or a salt thereof, -SO2N
H (CH2) 6COOH or a salt thereof, -SO2NH
C6H4COOH or a salt thereof, -CH2NHCOC
H2NH (CH2) 4COOH or a salt thereof, -CH
2NHCOCH2NH (CH2) 6COOH or a salt thereof, -CH2NHCOCH2NHC6H4COOH or a salt thereof, -CONH (CH2) 4COOH or a salt thereof, -CONH (CH2) 6COOH or a salt thereof, and -CONHC6H4COOH or a salt thereof. Preferably, a highly hydrophilic functional group such as -SO3H or -COOH is preferred, and the number of acidic functional groups is preferably one compound. When the number of substituents of the acidic functional group increases, the solubility in an organic solvent or resin serving as a dispersion medium increases, which is a major factor in lowering dispersion stability. Therefore, there is an optimum number of substituents depending on the chemical structure of the dye moiety, and an optimum composition ratio of the compound in the mixture exists.

The water-insoluble compound of the present invention having an acidic functional group bonded to the dye moiety can be produced by introducing an acidic functional group using the above-mentioned organic pigment as a dye component. For example, a compound in which a sulfonic acid group is bonded to a dye portion is produced by allowing a sulfonating agent such as fuming sulfuric acid, concentrated sulfuric acid, or chlorosulfuric acid to act on the pigment. In the sulfonation, it is preferable to control the reaction conditions such as the reaction temperature and the reaction time so that the solubility of the compound having a functional group in the dye moiety in the mixture in water is 0.2% by weight or less. The product obtained by this sulfonation step contains at least 3 to 70% by weight of an unreacted compound, which is a component of the pigment to be surface-treated, as a composition ratio. In this sulfonation step, it is preferable to produce a compound into which one sulfonic acid group has been introduced, and a highly water-soluble compound into which a plurality of sulfonic acid groups have been introduced has too high a hydrophilicity of the mixture itself. Since the adsorptive power to the pigment particle surface decreases, the smaller the content, the better.

In the present invention, the mixture of the water-insoluble compound having an acidic functional group bonded to the dye moiety and the compound which is a component of the organic pigment allows the latter compound to remain unreacted in the production of the former compound, After completion of the reaction, the solution can be obtained as a precipitate by pouring a solution of the reactant into a large amount of water. Alternatively, the former compound and the latter compound, which are individually manufactured, can be obtained as a precipitate by dissolving the compound in a strong acid such as sulfuric acid and then pouring the solution into a large amount of water.

As another example of the method of introducing an acidic functional group into the dye portion, a typical method for producing -SO2NH (CH2) 4COOH is outlined below. First, the organic pigment is chlorosulfonated with chlorosulfuric acid, and a compound having a chlorosulfonic acid group is reacted with 4-amino-n-butylic acid to form a functional group -SO2NH.
A compound having (CH2) 4COOH can be produced.

An acidic functional group is bonded to the dye moiety of the present invention.
Even if the acidic functional group of the compound that is hardly soluble in water forms a salt,
good. Examples of the salt include alkali metal salts such as Na and K;
NH _ThreeAlternatively, a salt with an organic amine is preferable. Organic net
Primary amine, secondary amine, tertiary amine
Min and quaternary amines can be used. Concrete
Typically, primary amines are ethylamine, propylamine,
Isopropylamine, butylamine, isobutylamine
, Sec-butylamine, ethanolamine, isopamine
Lopanolamine, octylamine, dodecylamine,
Laurylamine, stearylamine, oleylamine
The secondary amines are dimethylamine, diethylamine,
Dipropylamine, diethanolamine, distearyl
Tertiary amines such as amines
Tylamine, triethanolamine, triisopropano
Amine, dimethylethanolamine, diethyl eta
Nolamine, n-butyldiethanolamine, N, N
-Dimethyl-1,3-diaminopropane, N, N-die
Chill-1,3-diaminopropane, dimethyloctylua
Min, dimethyldecylamine, dimethyllaurylamine
Dimethyl myristylamine, dimethyl palmitia
Min, dimethyl stearyl amine, dimethyl behenylua
Min, dilauryl monomethylamine, trioctylami
Quaternary amines are dimethyldidodecylammonium
Muchloride, dimethyldioleyl ammonium chloride
Id, trimethyl stearyl ammonium chloride
And so on.

In the surface-treated pigment of the present invention, various dispersers can be used to adsorb the mixture on the surface of the organic pigment particles. As a dispersing machine, a paint conditioner (manufactured by Red Devil), a ball mill,
Sand mill (“Dyno mill” manufactured by Shinmaru Enterprises, etc.), attritor, pearl mill (“DCP mill” manufactured by Eirich, etc.), Koball mill, homomixer, homogenizer (“Clearmix” manufactured by M Technique Co., Ltd.), wet jet Mills (“Genus PY” manufactured by Genus, “Nanomizer” manufactured by Nanomizer) and the like. When using a medium as a dispersing machine, it is preferable to use glass beads, zirconia beads, alumina beads, magnetic beads, and styrene beads.

The amount of the mixture used in the present invention is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, based on 100 parts by weight of the organic pigment. If the amount of the mixture added to the pigment is less than the above value, the adsorbed amount of the mixture to the pigment is insufficient, and a satisfactory pigment dispersion cannot be obtained. On the other hand, when the content is too large, the viscosity of the dispersion increases and the adsorption efficiency is reduced, so that a satisfactory pigment dispersion cannot be obtained. Furthermore, the pigment concentration in the pigment dispersion in the mixture adsorption step of the present invention is preferably from 5 to 40% by weight, more preferably from 10 to 30% by weight.

The surface-treated pigment of the present invention is dispersed in an aqueous vehicle such as water or a non-aqueous vehicle such as a solvent.
As a dispersing machine, paint conditioner (Red Devil Co., Ltd.), ball mill, sand mill (Shinmaru Enterprises Co., Ltd. "Dyno Mill", etc.), attritor,
Pearl mill (e.g., "DCP mill" manufactured by Erich), Koball mill, homomixer, homogenizer ("Clearmix", manufactured by M Technique), wet jet mill ("Genus PY" manufactured by Genus, "Nanomizer" manufactured by Nanomizer) Good dispersion can be achieved by using an ultrasonic disperser or the like. When using a medium as a dispersing machine, it is preferable to use glass beads, zirconia beads, alumina beads, magnetic beads, and styrene beads.

Examples of the vehicle to which the surface-treated pigment of the present invention is preferably used include gravure inks such as lime rosin varnish, polyamide resin varnish or vinyl chloride resin varnish, nitrocellulose lacquer, amino-alkyd resin, and the like. Base resin paint, acrylic resin paint and the like.

The surface-treated pigment of the present invention can be used for coloring of plastics, water-based inks, water-based paints, emulsion-type inks, emulsion-type paints, and ink-jet inks in addition to non-aqueous inks and vehicles for coatings.
A coloring matter having excellent dispersing effect and coloring power can be obtained.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples. In the examples, parts represent parts by weight. The dispersion particle size of the mixture to be adsorbed in water and the measurement of the particle size of the pigment were measured by the following methods.

(1) Composition ratio measurement in a mixture of compounds which are components of an organic pigment in the mixture The mixture is dissolved in a polar solvent such as methanol, dimethylformamide, dimethylsulfoxide, 1-methyl-2-pyrrolidone. The mixture was separated using reverse-phase HPLC (HPLC column: Crestpak C18S manufactured by JASCO Corporation), and the composition ratio of the compound as a component of the organic pigment was measured.

(2) Dispersion Particle Size of the Mixture D50 was measured using a laser diffraction type particle size distribution analyzer (“Mitersizer 2000” manufactured by Sysmex Corporation).

(3) Average Particle Size of Pigment The pigment was dispersed in a solvent, applied on a cell, and observed with a transmission electron microscope (TEM) to determine the average particle size.

Production Example 1 (Production of mixture (a)) I. Pigment Yellow 180 (50 parts) was added to 750 parts of 95% by weight sulfuric acid at 10 ° C. or lower. Next, the mixture was heated and stirred at 15 ° C. for 1.5 hours, and then poured into ice water to precipitate. The precipitate was filtered and washed with 5% by weight saline to obtain 285 parts of a water paste of a mixture of a sulfonated product of a pigment and an unreacted product (52 parts when dried). Next, the water paste was reslurried with ion-exchanged water to prepare a 1% by weight aqueous dispersion,
After desalting and concentrating using an ultrafiltration device ("Centramate" manufactured by Pall Corporation) equipped with a filtration membrane ("Centramate Cassette" manufactured by Nippon Pall Co., Ltd., molecular weight: 300000), ion-exchanged water is added. Then, a 3% by weight aqueous dispersion of the mixture (a) was prepared. The composition ratio of the compound as the unreacted pigment component in this mixture was 32% by weight, and the dispersed particle size D50 in water was 95 nm.

Production Example 2 (Production of mixture (b)) I. Pigment Blue 15: 3 20 parts was added to a mixture of 150 parts of 22% by weight fuming sulfuric acid and 40 parts of 98% by weight of sulfuric acid at 20 ° C. or lower. Next, the mixture was heated and stirred at 47 ° C. for 3.5 hours, and then poured into ice water to precipitate. The precipitate was filtered and washed with 600 parts of 5% by weight hydrochloric acid, and 140 parts of a water paste of a mixture of a sulfonated product of a pigment and an unreacted product (2 parts when dried)
5 parts). Next, the above-mentioned water paste was reslurried with ion-exchanged water to prepare an 8% by weight aqueous dispersion, and a semi-permeable membrane ("Specc Medidal Industries", "Spec") was used.
tra / Por "molecular weight cut-off 12,000-14000)
After removing and concentrating the contained inorganic ion components using
Deionized water was added to prepare a 3% by weight aqueous dispersion of the mixture (b). The composition ratio of the compound which was the unreacted pigment component in this mixture was 25% by weight, and the dispersed particle size D50 in water was 160 nm.

Production Example 3 (Production of mixture (c)) I. Pigment Violet 19 (20 parts) was added to 98% by weight sulfuric acid (260 parts) at 20 ° C. or lower. There 6 parts of chloroacetamide and 2.5 parts of paraformaldehyde
Parts at 20 ° or less. Next, raise the temperature to 45.
After stirring at 5 ° C. for 5 hours, the mixture was poured into ice water to precipitate. The precipitate was filtered and washed with ion-exchanged water to obtain 175 parts of a water paste of a mixture of a chloroacetamidomethylated product of a pigment and an unreacted product (23 parts when dried). Next, 96 parts of the above-mentioned water paste (12.6 parts when dried) was dispersed in 1,000 parts of ion-exchanged water, and 6.5 parts of 4-aminobenzoic acid and an aqueous sodium hydroxide solution were added to adjust the pH to 10 and then raised. The mixture was heated and stirred at 90 ° C. for 4 hours. The precipitate was filtered, washed with ion-exchanged water, and dried to obtain 26 parts of a mixture (c). The composition ratio of the compound as the unreacted pigment component in this mixture was 35% by weight, and the dispersed particle size D50 in water was 80 nm.

Production Example 4 (Production of mixture (d)) I. Pigment Violet 19 (20 parts) was added to 98% by weight sulfuric acid (260 parts) at 20 ° C. or lower. There 3 parts of chloracetamide and 1.2 parts of paraformaldehyde
5 parts were added at 20 ° C. or less. Next, raise the temperature to 3
After stirring at 5 ° C. for 3 hours, the mixture was poured into ice water to precipitate. The precipitate was filtered and washed with ion-exchanged water to obtain 170 parts of a water paste of a mixture of a chloroacetamidomethylated product of a pigment and an unreacted product (21 parts when dried). Next, 80 parts of the above-mentioned water paste (9.9 parts when dried) was dispersed in 1,000 parts of ion-exchanged water, 4 parts of 4-aminobenzoic acid and an aqueous solution of sodium hydroxide were added to adjust the pH to 10, and then the temperature was raised. Stirring was performed at 90 ° C. for 4 hours. The precipitate is filtered, washed with ion exchanged water, dried and the mixture (d)
Was obtained in 22 parts. The composition ratio of the compound as the unreacted pigment component in this mixture was 73% by weight, and the dispersed particle size D50 in water was 120 nm.

Production Example 5 (Production of treating agent (e)) 4.0 parts of sodium hydroxide was dissolved in 100 parts of ion-exchanged water, and 8.65 parts of 4-aminobenzenesulfonic acid was added. 25 parts of concentrated hydrochloric acid was added thereto, and the mixture was cooled to 0 ° C. or lower. Next, 3.6 parts of sodium nitrite was added to deionized water 1
After dissolving in 0 parts, the mixture was dropped into the reaction system and stirred at 5 ° C. or lower for 1 hour. Next, 5.2 parts of sodium hydroxide were dissolved in 500 parts of ion-exchanged water, and 11.7 parts of acetoacetylbenzimidazole was added. 85% by weight acetic acid 1
2.8 parts were added, the diazonium salt solution prepared above was added dropwise, and the mixture was stirred at room temperature for 1 hour. The precipitate is filtered, washed with ion-exchanged water, dried, and treated with a treating agent (e) having the following structure.
One copy was obtained. This treating agent (e) was composed of only a compound containing one sulfonic acid group, was poorly soluble in water, and had a dispersed particle size D50 in water of 260 nm.

[0030]

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Production Example 6 (Production of Mixture (f)) 35 parts of concentrated hydrochloric acid was added to 100 parts of ion-exchanged water, and 4.65 parts of aniline was added, followed by cooling to 0 ° C. or lower.
Next, 3.6 parts of sodium nitrite were dissolved in 10 parts of ion-exchanged water, dropped into the reaction system, and stirred at 5 ° C. or lower for 1 hour. Next, 5.2 parts of sodium hydroxide were dissolved in 500 parts of ion-exchanged water, and 11.7 parts of acetoacetylbenzimidazole was added. To this, 85% by weight acetic acid.
Eight parts were added, the diazonium salt solution prepared above was added dropwise, and the mixture was stirred at room temperature for 1 hour. The precipitate was filtered, washed with ion exchanged water, and dried to obtain 16.5 parts of a product having the following structure. Next, 10 parts of the above product and 10 parts of the treating agent (e) obtained in Production Example 5 were added and dissolved in 200 parts of 95% by weight sulfuric acid at a temperature of 10 ° C. or lower, and then poured into ice water to precipitate. The precipitate was filtered, washed with ion exchanged water, and dried to obtain 16.3 parts of a mixture (f) having the following structure. In this mixture, the composition ratio of the compound similar to the constituent component of the pigment having no acidic functional group is 50% by weight, and the dispersed particle size in water D
50 was 145 nm.

[0032]

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Example 1 (Production of yellow surface-treated pigment) C.I. having an average primary particle size of 130 nm. I. 29.5 parts of CI Pigment Yellow 180, 79.5 parts of an aqueous dispersion of the mixture (a) obtained in Production Example 1 (3% by weight of solids) and 88.5 parts of ion-exchanged water were mixed, and the pH of the aqueous dispersion was mixed. Was adjusted to 9.0, and dispersed using a paint shaker with zirconia beads as a medium for about 5 hours to obtain a yellow surface-treated pigment in which the mixture (a) was adsorbed on the surface of the pigment particles. .

Example 2 (Production of a yellow surface-treated pigment) C.I. having an average primary particle size of 130 nm. I. 29.5 parts of CI Pigment Yellow 180, 79.5 parts of an aqueous dispersion of the mixture (f) obtained in Production Example 6 (3% by weight of solids) and 88.5 parts of ion-exchanged water are mixed, and the pH of the aqueous dispersion is mixed. Was adjusted to 9.0, and dispersed using a paint shaker with zirconia beads as a medium for about 5 hours to obtain a yellow-based surface-treated pigment having the mixture (f) adsorbed on the surface of the pigment particles. .

Example 3 (Production of a cyan-based surface-treated pigment) C.I. having an average primary particle size of 180 nm. I. Pigment Blue 15: 3 20 parts, an aqueous dispersion of the mixture (b) obtained in Production Example 2 54 parts (solid content 3% by weight) and ion exchange water 56 parts were mixed to adjust the pH of the mixture to 9.0. An aqueous solution of sodium hydroxide was added thereto, and the mixture was dispersed for about 7 hours using a zirconia bead as a medium using a paint shaker to obtain a cyan-based surface-treated pigment in which the mixture (b) was adsorbed on the surface of the pigment particles.

Example 4 (Production of magenta surface-treated pigment) C.I. having an average primary particle size of 140 nm. I. Pigment Red 122, 20 parts, mixture (c) obtained in Production Example 3
7 parts and 113 parts of ion-exchanged water are mixed, and p
Aqueous ammonia was added so that H became 9.0, and the mixture was dispersed for about 7 hours using a zirconia bead as a medium using a paint shaker to obtain a magenta-based surface-treated pigment in which the mixture (c) was adsorbed on the surface of the pigment particles. .

Application Example 1 Using the yellow surface-treated pigment obtained in Example 1, a paint was prepared according to the following formulation. The paint is placed in a container with components other than the resin to be added after the dispersion of the following formulation and placed in a container.
After adding φ-alumina beads and dispersing with a paint conditioner, the mixture was prepared by adding 37.5 parts of the following acrylic resin and 4.3 parts of a methylated melamine resin (trade name: Cymel 303, manufactured by Mitsui Cytec). Yellow-based surface-treated pigment 10.0 parts Acrylic resin solution (weight average molecular weight 25,000, acid value 60, monomer composition (weight ratio) acrylic acid / dimethylaminoethyl methacrylate / ethyl acrylate / methyl methacrylate / vinyl acetate = 7.7 /15/37.3/30/10 (solid content 20%)) 12.5 parts Ion-exchanged water 20.0 parts The obtained paint was evaluated by the following method. It showed luster.

Evaluation method of paint viscosity The viscosity of the obtained paint was evaluated with a B-type viscometer (measuring temperature 25 ° C, rotation speed 6 (rpm) and 60 (rpm)).

Evaluation method of coating film gloss The obtained water-based coating material was spread on a PET film with a 4 mil film applicator, baked at 140 ° C for 30 minutes, and measured with a digital variable gloss meter at 20 ° gloss. The sharpness of the surface was evaluated.

Comparative Example 1 (Production of a yellow surface-treated pigment) The average primary particle size was 13
C. which is 0 nm. I. Pigment Yellow 180 2
9.6 g, 2.4 g of the treating agent (e) obtained in Production Example 5 and 88.5 g of ion-exchanged water were mixed, and the pH of the mixture was 9.
Triethanolamine was added so as to be 0 and dispersed for about 5 hours using a zirconia bead as a medium using a paint shaker to obtain a yellow-based surface-treated pigment in which the treating agent (e) was adsorbed on the surface of the pigment particles. In Application Example 1, a coating material was prepared using 10 parts of the obtained yellow surface-treated pigment. The obtained paint was inferior to Example 1 in fluidity and gloss.

Application Example 2 Using the yellow surface-treated pigment obtained in Example 2, an ink was prepared according to the following formulation. The ink was prepared by placing components other than glycerin and ethylene glycol to be added after dispersion in the following formulation into a container, adding zirconia beads, dispersing with a paint shaker, and then adding glycerin and ethylene glycol. Cyan-based surface-treated pigment 8.0 parts Triethanolamine 1.0 part Ion-exchanged water 71.0 parts Glycerin 15.0 parts Ethylene glycol 5.0 parts The obtained ink was evaluated by the following method.
It was stable for more than 3 weeks at 0 ° C, and no bleeding was observed.

Evaluation Method of Ink Storage Stability The number of days of the storage period in which the obtained ink had a change in particle size at 70 ° C. of less than 15 nm and a change in viscosity of less than 0.5 cps was evaluated (dispersion particle size: laser diffraction). The particle size was measured using a particle size distribution meter (“Microtrack UPA” manufactured by Nikkiso Co., Ltd.) to measure D50 and D99.Viscosity: Vibration viscometer (“VM-1A” manufactured by Yamaichi Electric Co., Ltd.) in the low viscosity region. The viscosity at 25 ° C. was measured using a B-type viscometer for the medium viscosity region and above.)

Comparative Example 2 (Production of a yellow surface-treated pigment) The average primary particle size was 13
C. which is 0 nm. I. Pigment Yellow 180 2
9.6 g, 2.4 g of the treating agent (e) obtained in Production Example 5 and 88.5 g of ion-exchanged water were mixed, and the pH of the mixture was 9.
Triethanolamine was added so as to be 0 and dispersed for about 5 hours using a zirconia bead as a medium using a paint shaker to obtain a yellow-based surface-treated pigment in which the treating agent (e) was adsorbed on the surface of the pigment particles. In Application Example 2, an ink was prepared using 8.0 parts of the obtained yellow surface-treated pigment. In the obtained ink, the particle size and viscosity increased in one week at 70 ° C. as compared with Example 2, and crystals in which the treating agent (e) had grown in the sediment were confirmed.

Application Example 3 Using the cyan surface-treated pigment obtained in Example 3, an ink was prepared according to the following formulation. The ink was prepared by placing components other than glycerin and ethylene glycol to be added after dispersion in the following formulation into a container, adding zirconia beads, dispersing with a paint shaker, and then adding glycerin and ethylene glycol. Cyan-based surface-treated pigment 8.0 parts Triethanolamine 1.0 part Ion-exchanged water 71.0 parts Glycerin 15.0 parts Ethylene glycol 5.0 parts The obtained ink was evaluated by the following method.
It was stable for more than 3 weeks at 0 ° C, and no bleeding was observed.

Evaluation Method of Ink Storage Stability The number of days of storage period in which the obtained ink had a change in particle size at 70 ° C. of less than 15 nm and a change in viscosity of less than 0.5 cps was evaluated (dispersion particle size: laser diffraction). The particle size was measured using a particle size distribution meter (“Microtrack UPA” manufactured by Nikkiso Co., Ltd.) to measure D50 and D99.Viscosity: Vibration viscometer (“VM-1A” manufactured by Yamaichi Electric Co., Ltd.) in the low viscosity region. The viscosity at 25 ° C. was measured using a B-type viscometer for the medium viscosity region and above.)

Evaluation Method of Ink Bleeding Property (2) The solution was dropped on filter paper, and the bleed was visually evaluated.

Comparative Example 3 (Production of a surface-treated pigment of cyan type) The average primary particle size was 180.
nm. I. Pigment Blue 15: 3 20
g, 1.6 g of sodium salt of copper phthalocyanine tetrasulfonic acid (manufactured by Sigma-Aldrich Japan Co., Ltd.) and 108 g of ion-exchanged water, and dispersed using a paint shaker for about 7 hours using zirconia beads as a medium. A cyan surface-treated pigment obtained by adsorbing sodium sulfonate on the surface of pigment particles was obtained. In Application Example 3, an ink was prepared using 8 parts of the obtained cyan surface-treated pigment. The obtained ink was 1 hour at 70 ° C.
Weekly, the particle size and viscosity increased, and this ink was diluted with ion-exchanged water to a concentration of 3% by weight. 2 When the solution was dropped onto filter paper, bleeding of copper phthalocyanine tetrasulfonic acid sodium salt having high water solubility was confirmed.

Application Example 4 A coating material was prepared using the magenta-based surface-treated pigment obtained in Example 4 according to the following formulation. Paint, in the following formulation components other than the mixed varnish to be added after dispersion into a container,
After adding a steel ball and dispersing with a paint shaker, a mixed varnish was added to prepare the mixture. Magenta-based surface-treated pigment 10.0 parts Alkyd resin-based varnish (non-volatile content 60%) 26.4 parts Melamine resin-based varnish (non-volatile content 50%) 13.6 parts Thinner (xylene / n-butanol = 8/2) 20 0.03 parts Mixed varnish added after dispersion (alkyd resin-based varnish / melamine resin-based varnish = 7/3 (solid content)) 48.3 parts The obtained paint was evaluated by the following method. It showed a glossy coating.

Method for Evaluating Paint Viscosity The viscosity of the obtained paint was evaluated using a B-type viscometer (measuring temperature: 25 ° C., rotation speed: 6 rpm and 60 rpm).

Evaluation Method for Film Gloss The obtained paint was coated with a Ford cup 4 having a final paint viscosity of 23.
Seconds were prepared with a thinner, sprayed on a tin plate with an air spray gun and baked, and the glossiness of the coated surface was evaluated by measuring 20 ° gloss with a gloss meter.

Comparative Example 4 (Production of magenta surface-treated pigment) The average primary particle size was 14
C. which is 0 nm. I. Pigment Red 122 20
g, 1.7 g of the mixture (d) obtained in Production Example 4 and 113 g of ion-exchanged water were mixed, ammonia water was added so that the pH of the mixture became 9.0, and a paint shaker was prepared using zirconia beads as a medium. And the mixture (d) was adsorbed on the surface of the pigment particles to obtain a magenta-based surface-treated pigment. In Application Example 4, a paint was prepared using the obtained magenta-based surface-treated pigment as 10 parts.
The obtained paint was inferior to Example 4 in fluidity and gloss.

[0052]

The surface-treated pigment of the present invention, when mixed with a vehicle or a solvent to form an ink or paint, has excellent dispersion stability as compared with an untreated pigment, and can be stored for a long period of time. No pigment aggregation or sedimentation is observed.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshifumi Uemura 2-3-113 Kyobashi, Chuo-ku, Tokyo Inside Toyo Ink Manufacturing Co., Ltd.

Claims (6)

[Claims] 1. A mixture of a water-insoluble compound having an acidic functional group bonded to a dye portion and a compound as a component of an organic pigment, which is precipitated in water from a strong acid solution, is adsorbed on the surface of the organic pigment particles. A surface-treated pigment, characterized in that: 2. The surface-treated pigment according to claim 1, wherein the amount of the compound constituting the organic pigment is 3 to 70% by weight based on the mixture. 3. The surface-treated pigment according to claim 1, wherein the acidic functional group is —SO3H or a salt thereof. 4. A mixture of 100 parts by weight of an organic pigment and 1 to 50 parts by weight of a mixture precipitated in water from a strong acid solution of a water-insoluble compound in which an acidic functional group is bonded to a dye portion and a compound that is a component of the organic pigment. The surface-treated pigment according to any one of claims 1 to 3, comprising: 5. A pigment dispersion obtained by dispersing the surface-treated pigment according to claim 1 in a vehicle. 6. The pigment dispersion according to claim 5, wherein the vehicle is an aqueous medium.