JP2976761B2 - Pigment dispersant, pigment composition and aqueous pigment dispersion using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pigment dispersant which, when used in a water-based ink or water-based paint, has excellent film gloss and coloring power, good flowability and storage stability, and a pigment composition using the same. And an aqueous pigment dispersion.

[0002]

2. Description of the Related Art In recent years, water-based paints and inks have been developed due to increasing needs for resource protection, environmental protection, and improvement of work stability. The quality required for the water-based paint and the water-based ink is, like the oil-based paint and the oil-based ink, fluidity, storage stability, film gloss, sharpness, coloring power, and the like. However, most pigments have extremely poor suitability such as pigment dispersibility in an aqueous vehicle, so that satisfactory quality cannot be obtained by a usual dispersion method. Therefore, the use of various additives such as a pigment dispersing resin for water or a surfactant has been studied in the past.However, it satisfies all of the above suitability and obtains a quality comparable to existing high quality oil-based paints. Not been. That is, the gloss, clarity, coloring power, etc. of the film immediately after dispersion are improved to some extent by the use of a certain kind of aqueous dispersing resin. It is not always sufficient in the required fields, and further has practically fatal drawbacks such as loss of fluidity, thickening or gelling over time, and adversely affecting the physical properties of the film.

[0003]

As a method for solving the above-mentioned drawbacks, the inventor of the present invention used a diazotized product obtained by diazotizing an anthraquinone derivative or an acridone derivative having an aromatic amino group as a polymerization initiator to prepare an acidic functional group. The present inventors have found that a pigment dispersant characterized by polymerizing an addition-polymerizable monomer containing the above-mentioned addition-polymerizable monomer is effective, and have completed the present invention.

[0004]

SUMMARY OF THE INVENTION The present invention comprises an addition-polymerizable monomer having an acidic functional group using a diazotized product obtained by diazotizing an anthraquinone derivative or an acridone derivative having an aromatic amino group as a polymerization initiator. Pigment dispersant and pigment 1 characterized by polymerizing an addition polymerizable monomer
The present invention relates to a pigment composition comprising 00 parts by weight and 0.1 to 30 parts by weight of the above-mentioned pigment dispersant, and an aqueous pigment dispersion comprising the above-mentioned pigment composition and an aqueous resin.

The anthraquinone derivative or acridone derivative having an aromatic amino group of the present invention includes, for example, 1-aminoanthraquinone, 2-aminoanthraquinone, 1,2-diaminoanthraquinone, 1,4-diaminoanthraquinone, 1,5- Diaminoanthraquinone, 1-aminoacridone, 2-aminoacridone,
Compounds in which an amino group is directly bonded to an anthraquinone skeleton or an acridone skeleton such as 1,2-diaminoacridone, 1,4-diaminoacridone, 1,5-diaminoacridone, and any substitutable position of these compounds There are compounds having a substituent such as a nitro group, a sulfone group, a carboxyl group, a hydroxyl group, an alkyl group, an alkoxyl group, a halogen group, and a mercapto group.

[0006] These anthraquinone derivatives or acridone derivatives can be obtained by amino-substituting anthraquinone or acridone or a compound having a substituent introduced into them by a conventional method. As a method of amino substitution, for example, after nitrating the starting material anthraquinone or acridone with a mixed acid or the like, iron, zinc, a combination of a metal such as tin and an acid such as hydrochloric acid, acetic acid, iron, zinc, tin, etc. Reduction by a combination of a metal and an alkali such as sodium hydroxide or potassium hydroxide, or a reducing agent such as hydrogen sulfide and its alkali metal salt or hydrosulfite, or amino substitution by electrolytic reduction or catalytic reduction And a method in which a halogen group, a sulfone group, and a hydroxyl group are amino-substituted by ammonolysis.

[0007] The anthraquinone derivative or acridone derivative having an aromatic amino group of the present invention may also have an anthraquinone skeleton or an acridone skeleton containing -SO _2- , -C
_{O -, - CH 2 NHCOCH 2} -, - CH 2 - 2 -valent compound aromatic amino compound is bonded through a linking group, and a nitro group in any substitutable position of these compounds such as sulfone group And compounds having a substituent such as a carboxyl group, a hydroxyl group, an alkyl group, an alkoxyl group, a halogen group, and a mercapto group. These compounds are obtained by adding -SO ₂ Cl, -CO to anthraquinone or acridone or a compound having a substituent introduced therein.
Cl, -CH ₂ NHCOCH ₂ Cl, a substituent such as -CH ₂ Cl was introduced by a conventional method, containing both substituents, such as amino group or a hydroxyl group and an aromatic amino group capable of binding with these substituents Compounds such as o-phenylenediamine, m-phenylenediamine, 2-aminophenol,
It can be obtained by binding 3-aminophenol, 4-aminophenol and the like.

The method for diazotizing an anthraquinone derivative or an acridone derivative having an aromatic amino group of the present invention can be carried out according to a conventionally known method for diazotizing an aromatic primary amine. The diazonium salt can be isolated in the form of a more stable double salt by using a stabilizer such as zinc chloride or stannic chloride if necessary.

In the polymerization method of the present invention, a diazotized product obtained by diazotizing an anthraquinone derivative or an acridone derivative having an aromatic amino group is decomposed in the presence of an addition-polymerizable monomer, and the free radical formed is used as a polymerization initiator. And covalently bonding to an anthraquinone derivative or an acridone derivative. The form of polymerization is conventionally known polymerization methods, such as solution polymerization, emulsion polymerization, suspension polymerization, polymerization can be performed by any method such as bulk polymerization, but when used in an aqueous vehicle in a water-soluble organic solvent. Solution polymerization or emulsion polymerization is advantageous.

In the method for decomposing the diazotized product, the reaction system may be heated to 40 to 120 ° C., or an inorganic or organic reducing agent such as an alkali metal such as sodium, lithium, magnesium, calcium or the like, or an alkaline earth. Metals, zinc, aluminum, iridium, chromium, tin,
Heavy metals such as cerium, titanium, iron, copper, vanadium and their metal salt compounds, diisobutylaluminum hydride, organotin hydride, metal hydrides such as hydrosilane, lithium aluminum hydride, sodium aluminum hydride, sodium borohydride Metal hydrides such as lithium borohydride, calcium borohydride, potassium borohydride, zinc borohydride, tetraalkylammonium borohydride, diborane and substituted diborane, hydrazine, diimide, trialkylphosphine, triphenylphosphine , Trialkyl phosphite, hexamethylphosphorus triamide or the like.

The proportion of the addition-polymerizable monomer and the anthraquinone derivative or acridone derivative having an aromatic amino group as a polymerization initiator is such that the number of moles of the addition-polymerizable monomer is 10 to the number of moles of the polymerization initiator. And the weight average molecular weight of the resulting dispersant is from 2000 to 10.
It is preferable to select 0000. In addition, the reaction rate of the polymerization initiator varies depending on the polymerization reaction system, and an unreacted initiator may remain, but this does not affect the performance of the dispersant at all.

As the addition polymerizable monomer of the present invention, all conventionally known addition polymerizable monomers can be used. For example, unsaturated carboxylic acids and their esters, acid anhydrides, acid chlorides, acid amides, derivatives such as methylolamide and alkylmethylolamide, vinyl monomers, diene monomers, ethylene, etc. . Examples of the addition polymerizable monomer having an acidic functional group include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, and fumaric acid.

Other addition-polymerizable monomers include methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, n- (meth) acrylate
Butyl, isopropyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, lauryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate , 2-hydroxypropyl (meth) acrylate,
(Meth) acrylamide, N-methylol acrylamide, diacetone acrylamide, glycidyl (meth) acrylate, (meth) acrylic acid chloride, methyl crotonate, ethyl crotonate, propyl crotonate, n-butyl crotonate, isopropyl crotonate, croton Isobutyl acid, 2-ethylhexyl crotonate, n-hexyl crotonate, lauryl crotonate, 2-hydroxyethyl crotonate, 2-hydroxypropyl crotonate, crotonamide, N-methylol crotonamide, diacetonecrotonamide, glycidyl crotonate Crotonic acid chloride, monomethyl itaconate, monoethyl itaconate, monopropyl itaconate, mono-n-butyl itaconate, monoisopropyl itaconate,
Monoisobutyl itaconate, mono-2-ethylhexyl itaconate, mono-n-hexyl itaconate, monolauryl itaconate, mono-2-hydroxyethyl itaconate, mono-2-hydroxypropyl itaconate, itaconamide, N-methylol Itaconamide, diacetone itaconamide, monoglycidyl itaconate, itaconic chloride, dimethyl itaconate, diethyl itaconate, dipropyl itaconate, di-n-butyl itaconate, diisopropyl itaconate, diisobutyl itaconate, di-2 itaconate -Ethylhexyl, di-n-hexyl itaconate, dilauryl itaconate, di-2-hydroxyethyl itaconate, di-2-hydroxypropyl itaconate, itacondiamide, N, N-dimethylolitacondiamide Diacetone itaconate Nji amides, diglycidyl itaconate, itaconic acid anhydride, maleic acid -
Monomethyl, monoethyl maleate, monopropyl maleate, mono-n-butyl maleate, monoisopropyl maleate, monoisobutyl maleate, mono-2-ethylhexyl maleate, mono-n-hexyl maleate, monolauryl maleate, maleic acid Mono-2-hydroxyethyl, mono-2-hydroxypropyl maleate, maleic monoamide, N-methylol maleamide, diacetone maleamide, monoglycidyl maleate, maleic chloride, dimethyl maleate, diethyl maleate, dipropyl maleate Di-n-butyl maleate, diisopropyl maleate, diisobutyl maleate, di-2-ethylhexyl maleate,
Di-n-hexyl maleate, dilauryl maleate,
Di-2-hydroxyethyl maleate, di-maleate
2-hydroxypropyl, maleic diamide, N, N-
Dimethylol maleic diamide, diacetone maleic diamide, diglycidyl maleate, maleic anhydride, monomethyl fumarate, monoethyl fumarate, monopropyl fumarate, mono-n-butyl fumarate, monoisopropyl fumarate, monoisobutyl fumarate, Fumaric acid mono-2
-Ethylhexyl, mono-n-hexyl fumarate, monolauryl fumarate, mono-2-hydroxyethyl fumarate, mono-2-hydroxypropyl fumarate, fumaramido, N-methylol fumaramido, diacetone fumaramido, monoglycidyl fuma Rate, fumaric acid chloride, dimethyl fumarate, diethyl fumarate, dipropyl fumarate, di-n-butyl fumarate, diisopropyl fumarate, diisobutyl fumarate, di-2-ethylhexyl fumarate, di-n-hexyl fumarate, Dilauryl fumarate, di-2-hydroxyethyl fumarate, di-2-hydroxypropyl fumarate, fumadiamide, N, N
-Alkyl carboxylate such as dimethylol fumadiamide, diacetone fumadiamide, diglycidyl fumarate. Examples of the vinyl monomer include vinyl acetate, vinyl alcohol, vinyl chloride, vinyl toluene, styrene, vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl n-butyl ether, vinyl isopropyl ether, vinyl isobutyl ether, and acrylonitrile. , Vinylidene chloride, vinyl fluoride, vinylidene fluoride, vinyl carbazole, vinyl pyrrolidone, vinyl pyridine, vinyl imidazole, and the like, and diene monomers include butadiene, chloroprene, isoprene and the like.

These monomers can be used in any ratio except that the above-mentioned unsaturated carboxylic acid is used as an essential component, but a monomer having a similar composition to the resin used in the vehicle in which the pigment is dispersed is used. A larger effect can be obtained by using. The proportion of the unsaturated carboxylic acid used is preferably from 5 to 30% by weight based on all monomers. By selecting the above-mentioned monomers, the pigment dispersant of the present invention has an effect on almost all types of aqueous inks or paints currently used, and more preferably an acrylic copolymer type aqueous solution. The effect is great for aqueous inks or paints composed of a water-soluble resin or a water-dispersible resin alone or as a mixture. Further, since there is almost no coloring, there is an advantage that it can be used for inks or paints of all hues. When the pigment dispersant of the present invention is used, it may be used in the form of a dry powder, or may be used after being dissolved or dispersed in a solvent compatible with the ink or paint used. Particularly when used in an aqueous vehicle, a solution or dispersion obtained by neutralizing a pigment dispersant with an inorganic alkali, ammonia, or an organic amine and adding water, or an aqueous dispersion of a pigment dispersant obtained by emulsion polymerization Is industrially advantageous.

The inorganic alkali used for neutralization includes, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium hydrogen carbonate, and the like. The organic amine includes, for example, ammonia, methylamine, dimethylamine, and the like. Trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, isobutylamine, diisobutylamine, 2-butanamine, N-
(1-methylpropyl) -1-propanamine, N, N
-Dimethylbutylamine, 1,2-dimethylpropylamine, N-ethyl-1,2-dimethylpropylamine,
Allylamine, diallylamine, triallylamine,
N, N-dimethylallylamine, N-methyldiallylamine, 3-pentylamine, N, N-diisopropylethylamine, 2- (hydroxymethylamino) ethanol, 2-aminolopanol, 3-aminolopanol, triethanolamine, dimethylaminopropanol, N
-Isobutyldiethanolamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-propyloxypropylamine, 3-isopropyloxypropylamine, 3-butoxypropylamine and the like.

When a dry powder is used, it may be added at the time of dispersing the pigment, or may be used by mixing with the pigment in advance. When using a solution dissolved or dispersed in a solvent, it may be added either at the time of dispersing the pigment or after forming the paint.Add it to the water of the pigment or a slurry of the solvent and adsorb it on the surface of the pigment. It may be used as a dried pigment composition accordingly. The pigment composition of the present invention can be obtained by mixing the pigment dispersant of the present invention with a pigment. The mixing method may be to mix the dried pigment dispersant powder with the pigment or to add the pigment dispersant dissolved or dispersed in a solvent to a pigment water or solvent slurry, followed by filtration and drying as necessary. The simplest method is to apply a powder or a solution or a dispersion liquid of a pigment dispersant during a coupling process for an azo pigment, a phthalocyanine pigment, a quinacridone pigment, and a dioxazine pigment during a pigmentation step such as a salt milling method and a sulfuric acid dissolving method. It can also be obtained by a method of adding and adsorbing on the surface of the pigment.

In the present invention, the proportion of the pigment dispersant used is 0.1 to 30 parts by weight with respect to 100 parts by weight of the pigment.
When used in an amount of more than 0 parts by weight, the performance of the film when used in ink or paint is adversely affected. Pigments used in the pigment composition of the present invention include, for example, phthalocyanine pigments, insoluble azo pigments, azo lake pigments, anthraquinone pigments,
Quinacridone pigments, dioxazine pigments, diketopyrrolopyrrole pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, perinone pigments, perylene pigments, thioindigo pigments, carbon black, iron oxide, lead white, lead tin, Ultramarine, navy blue, cobalt oxide, titanium dioxide, titanium dioxide coated mica, strontium chromate, titanium yellow, titanium black, zinc chromate, iron black, molybdenum red, molybdenum white, lithopone, emerald green, cadmium yellow, cadmium red, cobalt blue, etc. There is.

The aqueous resin used in the aqueous pigment dispersion of the present invention includes acrylic copolymers, styrene-acrylic acid copolymers, styrene-maleic acid copolymers, alkyds, epoxies, polyesters, and urethanes. And the like, and an acrylic copolymer-based water-dispersible resin or a water-soluble resin is particularly preferable. The acrylic copolymer-based resin is composed of 50 to 80% by weight of a (meth) acrylic acid alkyl ester and 5 to 3 carboxylic acid-containing monomers such as acrylic acid, methacrylic acid, maleic acid and itaconic acid.
It is a resin having a weight average molecular weight of 5,000 to 300,000 and an acid value of 1 to 200, obtained by emulsion polymerization or solution polymerization of 0 to 20% by weight of other monomers in an aqueous solvent. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylate. ) Isobutyl acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, lauryl (meth) acrylate, and the like. Examples of the other monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, acrylamide, N-methylolacrylamide,
Examples include diacetone acrylamide, glycidyl (meth) acrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, vinyl alcohol, and ethylene.

The above water-dispersible resin can be produced by dropping a mixture of the above monomers into an aqueous medium containing an emulsifier and emulsion-polymerizing the mixture. A high molecular weight dispersant may be used instead of or in combination with the emulsifier. The water-dispersible resin of the present invention may be dispersed in the aqueous dispersion by neutralizing the carboxylic acid incorporated in the resin by adding an amine or ammonia. For example,
A water-dispersible resin can be obtained by neutralizing an acrylic copolymer resin having a free carboxylic acid polymerized in a hydrophilic organic solvent with ammonia or an organic amine and adding water. As the organic amine used here, those described above can be used here.

The water-soluble resin can be obtained by neutralizing an acrylic copolymer resin having a free carboxylic acid polymerized from the monomer in a hydrophilic organic solvent with the organic amine and adding water. it can. The aqueous medium of the aqueous resin used in the present invention may be only water,
In some cases, an alcohol-based solvent such as ethyl alcohol, isopropyl alcohol, n-propyl alcohol, or n-butanol, or a water-miscible organic solvent such as ethylene glycol or diethylene glycol mono- or dialkyl ether is mixed up to 50% by weight in an aqueous medium. Can be done.

In the method for producing an aqueous pigment dispersion of the present invention, it is most simple to mix a pigment and a pigment dispersant into a dispersion or solution of an aqueous resin, respectively. Alternatively, a pigment composition comprising a pigment and a pigment dispersant may be blended into a dispersion or solution of an aqueous resin. The mixing ratio of each is 100 parts by weight of the pigment, 0.1 to 30 parts by weight of the pigment dispersant, and 5 to 200 parts by weight of the solid content of the aqueous resin. In order to disperse the pigment or the pigment composition in the dispersion or solution of the aqueous resin, it is preferable to use a disperser such as a dissolver, a high-speed mixer, a homomixer, a sand mill, and an attritor. The aqueous pigment dispersion of the present invention can be used as an aqueous printing ink or an aqueous paint, and as a concentrated dispersion thereof.

[0022]

【Example】

Production Example 1 0.7 parts of sodium nitrite was added to 20 parts of cooled 98% sulfuric acid, heated to 70 ° C., cooled again, and 2.2 parts of 2-aminoanthraquinone was added at 10 ° C. or less. After stirring at 10 ° C. for 1 hour, 10 parts of ethyl acrylate and 10 parts of methyl methacrylate were cooled to 10 ° C. or less.
It was added dropwise to a solution consisting of 5 parts of methacrylic acid and 50 parts of diethylene glycol dimethyl ether. After heating in a nitrogen stream and polymerizing at 80 ° C. for 2 hours, 100 parts of water was added to precipitate a resin component, which was filtered, washed with water, dried and pulverized to obtain 24 parts of a resin powder.

Production Example 2 0.7 parts of sodium nitrite was added to 20 parts of cooled 98% sulfuric acid, heated to 70 ° C., cooled again, and 2.2 parts of 2-aminoanthraquinone was added at 10 ° C. or less. After stirring at 10 ° C. for 1 hour as it was, it was added dropwise to 200 parts of a 25% aqueous zinc chloride solution cooled to 10 ° C. or lower to precipitate a zinc chloride double salt of a diazonium compound, which was filtered and washed with water. The obtained press cake is dispersed in a solution composed of 10 parts of ethyl acrylate, 10 parts of methyl methacrylate, 5 parts of methacrylic acid, and 50 parts of diethylene glycol dimethyl ether, and the mixture is stirred for 30 minutes in a nitrogen stream. Then, polymerization was carried out at 60 ° C. for 2 hours. The pH was adjusted to 8 with an aqueous triethanolamine solution to give a solid content of 22.
% Resin dispersion was obtained.

Production Example 3 0.7 parts of sodium nitrite was added to 20 parts of cooled 98% sulfuric acid, heated to 70 ° C., cooled again, and 2.2 parts of 2-aminoanthraquinone was added at 10 ° C. or lower. After stirring at 10 ° C. for 1 hour as it was, it was added dropwise to 200 parts of a 25% aqueous zinc chloride solution cooled to 10 ° C. or lower to precipitate a zinc chloride double salt of a diazonium compound, which was filtered and washed with water. The obtained press cake, 1000 parts of ethyl acrylate, 1000 parts of methyl methacrylate, 500 parts of methacrylic acid,
Dispersed in a cooled emulsion consisting of 200 parts of sodium lauryl sulfate and 5000 parts of water, stirred in a nitrogen stream for 30 minutes, and added with 500 parts of a 20% aqueous solution of titanium trichloride.
Polymerization was performed at 0 ° C. for 2 hours, and the pH was adjusted to 8 with aqueous ammonia to obtain 10,000 parts of a resin dispersion having a solid content of 25%.

Production Examples 4 to 6 Resin powders and resin dispersions were obtained in exactly the same manner as in Production Examples 1 to 3, except that 2-aminoacridone was used instead of 2-aminoanthraquinone.

Example 1 10 parts of CI Pigment Blue 15: 1, 1 part of the resin powder obtained in Production Example 1, 12.5 parts of an acrylic resin solution having a weight average molecular weight of 25,000 and an acid value of 60 (solid content 20%), ion-exchanged water 20 parts, and 3
150 parts of mmφ alumina beads were placed in a 225 ml glass container and dispersed with a paint conditioner for 3 hours. 37.5 parts of the above acrylic resin and methylated melamine resin (trade name
4.3 parts of Cymel 303 (manufactured by Mitsui Cyanamid) were added and mixed to obtain an aqueous paint. The obtained water-based paint was spread on a PET film using a 4 mil film applicator, and heated at 140 ° C for 30 minutes.
After baking for a minute, an excellent film gloss was obtained. The gloss was measured at 20 ° gloss using a digital variable-angle gloss meter. Table 1 shows the measurement results.

Examples 2 to 20 Various pigments were coated with the resin powders and resin dispersions obtained in Production Examples 2 to 6 in the same manner as in Example 1 (provided that the resin dispersion was The addition amount was converted to solid content.) Similarly, excellent film gloss was obtained. Table 1 shows the results.
And Table 2.

Example 21 A wet cake containing 20 parts of CI Pigment Blue 15: 1 was dispersed in 200 parts of water, and 4.5 parts of the resin dispersion obtained in Production Example 2 was added and mixed. Then filtration, washing, drying,
The mixture was pulverized to obtain 23 parts of a pigment composition. When the obtained pigment composition was formed into a paint and colored by the following methods, excellent film gloss was obtained. Table 1 shows the measurement results.

(Method of coating and spreading) 10 parts of a pigment composition, 12.5 parts of an acrylic resin solution having a weight average molecular weight of 25,000 and an acid value of 60 (solid content: 20%), 20 parts of ion-exchanged water, and 150 parts of 3 mmφ alumina beads Was placed in a 225 ml glass container and dispersed with a paint conditioner for 3 hours. Acrylic resin above
37.5 parts and methylated melamine resin (trade name Cymel 303
4.3 parts (Mitsui Cyanamid) were added and mixed to obtain an aqueous paint. The resulting water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes. The gloss was measured at 20 ° gloss using a digital variable-angle gloss meter.

Examples 22 to 24 The pigment dispersions obtained in Production Examples 2, 3, 5, and 6 were mixed with various pigments according to Example 21, and the mixture was formed into a paint and spread. A film gloss was obtained. Table 1 shows the results.

COMPARATIVE EXAMPLE The pigment used in Examples 1 to 24 was made into a paint without adding the resin powder or the resin dispersion obtained in Production Examples 1 to 6, and was colored. I was The results are shown in Tables 1 and 2.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

EFFECT OF THE INVENTION According to the present invention, there are no drawbacks such as an increase in viscosity with time and adverse effects on the physical properties of the film. A pigment dispersion such as a water-based paint or a water-based printing ink that satisfies gloss, sharpness, coloring power, and the like can be obtained. In addition, since the anthraquinone derivative or the acridone derivative itself has almost no coloring, it can be used as a general-purpose pigment dispersant without considering the hue of the pigment.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09C 3/10 C09C 3/10 C09D 5/02 C09D 5/02 7/02 7/02 // C08F 4/04 C08F 4/04 (58) Field surveyed (Int.Cl. ⁶ , DB name) C09D 17/00 C09B 67/20 C09C 3/10 C09D 5/00 C09D 7/00

Claims (3)

(57) [Claims] 1. A diazotized product obtained by diazotizing an anthraquinone derivative or an acridone derivative having an aromatic amino group is used as a polymerization initiator to polymerize an addition polymerizable monomer containing an addition polymerizable monomer having an acidic functional group. Pigment dispersing agent that is at least used. 2. A pigment composition comprising 100 parts by weight of a pigment and 0.1 to 30 parts by weight of the pigment dispersant according to claim 1. 3. An aqueous pigment dispersion comprising the pigment composition according to claim 2 and an aqueous resin.