JP2001081390A - Aqueous pigment dispersion, its production and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous pigment dispersion capable of providing an aqueous coating composition having the same fluidity, storage stability, luster of coating film, clarity, tinting strength, etc., as those of oily coating material and an oily ink and to provide a method for producing the aqueous pigment dispersion. SOLUTION: This aqueous pigment dispersion is obtained by a process (1) for kneading (A) a pigment with (B) a resin which is prepared by copolymerizing an ethylenically unsaturated monomer composition composed of (a) an ethylenically unsaturated monomer containing at least one carboxy group in the molecule and (b) an ethylenically unsaturated monomer containing at least one hydroxy group in the molecule and has >=0 deg.C Tg by rolls to give a solid chip and a process (2) for dispersing the solid chip into an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an aqueous pigment dispersion having excellent dispersion stability, a method for producing the same, and an aqueous coating composition using the pigment dispersion.

[0002]

2. Description of the Related Art Conventionally, water-based paints and inks have been developed with increasing needs for resource protection, environmental protection, improvement of work stability, and the like.

The qualities required for aqueous paints and inks are fluidity, storage stability, gloss, sharpness, tinting strength, etc., similar to oil-based paints and oil-based inks.

However, most pigments are extremely poor in suitability such as pigment dispersibility in an aqueous vehicle as compared with oily ones, and satisfactory quality cannot be obtained by ordinary dispersing methods. Therefore, conventionally, the use of various additives, for example, a pigment dispersing resin for water or a surfactant has been considered, but it is comparable to an existing high-quality oil-based paint or oil-based ink that satisfies all of the above suitability. Things have not been obtained.

[0005] In particular, in fields where pigments are required to be miniaturized, such as ink jet and automotive coatings, satisfactory satisfactorily high quality has not been obtained.

[0006]

A water-based paint or ink which improves the above-mentioned various drawbacks and has the same fluidity, storage stability, film gloss, sharpness, coloring power, etc. as oil-based paints or oil-based inks. It is an object of the present invention to provide an aqueous coating composition as described above. Another object of the present invention is to provide an aqueous pigment dispersion capable of providing the aqueous coating composition and a method for producing the same.

[0007]

That is, the first invention comprises (A) a pigment, (B) (a) an ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule, and (b) Tg0 obtained by copolymerizing an ethylenically unsaturated monomer composition containing an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule.
An aqueous pigment dispersion obtained by a step (1) of kneading a resin at a temperature of not less than ° C with a roll to form a solid chip, and a step (2) of dispersing the solid chip in an aqueous medium.

A second invention is the aqueous pigment dispersion according to the first invention, wherein the step (1) is carried out in the presence of (C) water and / or a water-miscible organic solvent.

A third invention is the aqueous pigment dispersion according to the first or second invention obtained through a step (3) of further dispersing the dispersion obtained in the step (2) by a media type disperser. .

In a fourth aspect, the step (1) or the step (2) comprises:
The aqueous pigment dispersion according to any one of the first to third inventions, which is performed in the presence of a basic organic dye derivative.

A fifth invention is the aqueous pigment dispersion according to any one of the first to fourth inventions, wherein the step (2) is carried out in the presence of an alkali compound.

A sixth aspect of the present invention relates to (A) a pigment, and (B)
(A) an ethylenically unsaturated monomer containing at least one carboxylic acid group in the molecule and (b) an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule A step (1) of kneading a resin having a Tg of 0 ° C. or higher obtained by copolymerizing the body composition with a roll to form a solid chip, and then dispersing the solid chip in an aqueous medium (2). It is a characteristic aqueous pigment dispersion.

A seventh aspect of the present invention is an aqueous coating composition comprising the aqueous pigment dispersion according to any one of the first to fifth aspects.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The pigment (A) used in the present invention includes:
For example, azo pigments such as soluble and insoluble azo pigments and condensed azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, perylene / perinone pigments, dioxazine pigments, anthraquinone pigments, diketopyrrolopyrrole pigments Organic pigments such as pigments, anthrapyrimidine pigments, anthanthrone pigments, indanthrone pigments, flavanthrone pigments, thioindigo pigments, carbon black, titanium oxide, graphite, cadmium yellow, cadmium red, red stalk, iron There are inorganic pigments such as black, zinc white, navy blue, and ultramarine blue.

The resin (B) used in the present invention comprises (a)
Ethylenically unsaturated monomer composition containing an ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule and (b) an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule Is obtained by copolymerizing

(A) The ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule is not particularly limited. For example, acrylic acid, methacrylic acid, 2-carboxyethyl acrylate, phthalic acid Monohydroxyethyl acrylate, ω-carboxy-polycaprolactone monoacrylate, maleic acid, itaconic acid, fumaric acid, glutaconic acid, tetrahydrophthalic acid, and mixtures thereof, and the like.

(A) The ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule is preferably 1 to 50% by weight of the ethylenically unsaturated monomer. 1% by weight
In the following, it is difficult to sufficiently disperse the pigment, and when it is 50% by weight or more, the viscosity of the pigment dispersion easily increases, which is not preferable.

(B) The ethylenically unsaturated monomer having at least one hydroxyl group in the molecule is not particularly restricted but includes, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl ( (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 2-
Hydroxybutyl (meth) acrylate, glycerin (meth) acrylate, polyethylene glycol mono (meth) acrylate (n = 2 to 50), polycaprolactone-modified hydroxyethyl (meth) acrylate (n
= 1 to 6), epoxy (meth) acrylate, hydroxyl-terminated urethane (meth) acrylate, and mixtures thereof.

(B) The ethylenically unsaturated monomer having at least one hydroxyl group in the molecule is preferably 1 to 50% by weight of the ethylenically unsaturated monomer. If it is less than 1% by weight, it is difficult to sufficiently disperse the pigment.
It is not preferable because the viscosity of the pigment dispersion easily increases.

Further, (a) an ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule and (b) an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule. The ethylenically unsaturated monomer composition may contain other ethylenically unsaturated monomers as required. Other ethylenically unsaturated monomers are not particularly limited, and include, for example, styrene, vinyl toluene, alkyl (meth) acrylate, (meth) acrylonitrile, vinyl acetate, vinyl alkyl ether and the like. .

The polymerization of the ethylenically unsaturated monomer is carried out in the presence of an initiator under an inert gas stream at 50 to 150 ° C.
This takes place over 10 hours. If necessary, the reaction may be performed in the presence of a solvent.

Examples of the initiator include organic peroxides such as benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, diisopropyl peroxycarbonate, di-t-butyl peroxide and t-butyl peroxybenzoate. And azo compounds such as 2'-azobisisobutyronitrile. The initiator is preferably used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the ethylenically unsaturated monomer.

The resin has a Tg of 0 ° C. or higher, preferably 0 to 60 ° C., and more preferably 15 to 40 ° C.
If the temperature is 0 ° C. or lower, a uniform sheet cannot be obtained during kneading and dispersing the rolls, resulting in poor workability and no good quality.

In the present invention, the blending amounts of the (A) pigment and the (B) resin in the step (1) are as follows:
The amount of the resin (B) is preferably 5 to 100 parts by weight, more preferably 10 to 40 parts by weight with respect to parts by weight. If the amount of the resin is less than the above values, the effect of dispersing the pigment is small,
It is not preferable because the workability is poor, and even if the amount of the resin is larger than the above value, the effect of the used amount cannot be obtained.

In the present invention, in the step (1), (C)
It is preferred to add water and / or a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohol solvents such as ethyl alcohol, isopropyl alcohol, and n-propyl alcohol, and mono- or dialkyl ethers of ethylene glycol or diethylene glycol.

Further, it is preferable that the water and / or water-miscible organic solvent (C) added in the step (1) remain in the solid chip, and in this case, the solid content of the solid chip is 80 to 98. % By weight is preferred. If the non-volatile content of the solid chips is less than 80% by weight, the shear force at the time of kneading the rolls is insufficient, so that the quality of the coating film is poor and problems such as sticking during storage of the solid chips are liable to occur. If the non-volatile content of the solid chips is more than 98%, the dispersibility of the solid chips in the aqueous medium is poor in step (2), and the undispersed coarse particles tend to cause deterioration in coating film quality.

The roll in the present invention includes two rolls and three rolls. Preferably, two rolls having a large shear force are used.

As the aqueous medium used in the step (2) in the present invention, water alone may be used, but it is preferable to add a small amount of an alkali compound or a water-miscible organic solvent since dispersion becomes easy. Examples of the alkali compound include various organic amine compounds such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, 2-aminoethanol, 2-dimethylaminoethanol, and 2-diethylaminoethanol; ammonia; and sodium hydroxide. Representative inorganic basic substances and other various quaternary ammonium compounds can be used. In particular, organic amine compounds are preferred from the viewpoint of workability and versatility. The amount of the alkali compound added is as follows: (A) Pigment 1
0.1 to 5 parts by weight is preferable with respect to 00 parts by weight.

As the water-miscible organic solvent, those described above can be used. The addition amount of the water-miscible organic solvent is preferably 5 to 30 parts by weight based on 100 parts by weight of the pigment (A).

It is preferable to add an aqueous resin in the step (2). The Tg of the aqueous resin to be added is not specified at all, and can be selected from known ones used for aqueous coating compositions such as aqueous inks and aqueous paints. Examples include acrylic copolymers, styrene-acrylic acid copolymers, styrene-maleic acid copolymers,
Water-dispersible resins or water-soluble resins such as alkyd, epoxy, polyester, urethane, and cellulose are exemplified. In the step (2), the compounding amount of the aqueous resin is preferably 5 to 200 parts by weight based on 100 parts by weight of the pigment (A) as the compounding amount with respect to the pigment.

In the present invention, as a dispersion method in the step (2), it is preferable to put a solid chip in an aqueous medium and stir for a certain time using a disperser such as a dissolver, a high-speed mixer or a homogenizer. At this time, it is desirable to apply a temperature of 30C to 80C as needed.

In the present invention, in the step (1) or (2), an organic dye derivative is preferably added in order to improve the dispersibility of the pigment. As the organic dye derivative, there is a compound represented by the following general formula 1 or the following general formula 2. General formula 1

[0034]

Embedded image[Wherein Q is an organic dye residue, X is a direct bond, -COOH
-Y₁Or -SO_TwoNH-Y₁− (Y₁Has a substituent
An alkylene group or an optionally substituted
Z represents a hydroxyl group or -NH- (CH
_Two)_mNR₁R _Two(R₁, R_TwoAre each independently a substituent
And m is an integer of 1 to 6.
You. ), N represents an integer of 1 to 4. General formula 2 Q- [XY] n wherein Q is an organic dye residue, X is a direct bond, -CONH
-Y₁-, -SO_TwoNH-Y₁-, -CH_TwoNHCOC
H_TwoNH-Y₁−

[0035]

Embedded image (Y ₁ represents the same meaning as above.) Y is-(CH ₂ ) _m
NR ₁ R ₂ or

[0036]

Embedded image (R ₁ , R ₂ and m represent the same meaning as described above.) N represents the same meaning as described above. The organic dye residue in the above general formula includes phthalocyanine dyes, azo dyes, anthraquinone dyes, quinacridone dyes, dioxazine dyes, anthrapyrimidine dyes, anthanthrone dyes, indanthrone dyes, flavans It is a residue of a sulphone dye, a perylene / perinone dye, a thioindigo dye, an isoindolinone dye, a diketopyrrolopyrrole dye, or the like.

Of the above organic dye derivatives, -NR ₁ R ₂
Basic organic dye derivatives having a group are preferred.

The proportion of the organic dye derivative to the pigment is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the pigment (A). If the amount is less than 0.5 part by weight, the effect is small and it is not preferable. Further, even if it is used in an amount of more than 10 parts by weight, the effect of the used amount cannot be obtained, and there is a possibility that the coating film performance is adversely affected.

The media type disperser in the step (3) of the present invention is not particularly limited,
It is preferable to use a bead mill such as a sand mill, an attritor, and a DCP mill. As the medium, glass beads, zirconia beads, alumina beads and the like can be used.

In step (3) of the present invention, an aqueous resin can be added as required. As the aqueous resin, it is preferable to add 10 to 1000 parts by weight, in terms of solid content, based on 100 parts by weight of the pigment (A) among the known aqueous inks and water-based paints described above. In particular, when used as a concentrated dispersion, (A) pigment 100
The resin is preferably 10 to 200 parts by weight on a solids basis with respect to parts by weight, and when used as a paint or printing ink, the resin is 100 to 1000 parts by weight on a solids basis with respect to 100 parts by weight of the pigment (A). Is preferred. (A) Pigment 10
If the resin is less than 10 parts by weight with respect to 0 parts by weight, the pigment is difficult to disperse.

When the aqueous pigment dispersion of the present invention is used as a paint or printing ink, a curing agent resin such as a melamine resin, a curing catalyst, a surfactant and the like may be added. If necessary, conventionally known additives such as a preservative and an adhesion control agent may be added.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
In the examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

Production Example 1 A temperature control regulator was placed in a separable four-necked flask.
Attach a cooling pipe and stirrer, and install butyl carbitol 6
After charging 5.7 parts, the temperature was raised to about 95 ° C., and the inside of the reaction vessel was purged with nitrogen.
0 parts, ethyl acrylate 30 parts, butyl acrylate 10 parts, 2-hydroxyethyl methacrylate 20 parts,
One part of 2,2'-azobisisobutyronitrile was added dropwise over 2 hours. After the completion of the dropwise addition, the reaction was continued for another 3 hours,
A resin having a Tg of 40 ° C. was obtained. After cooling, 19.8 parts of dimethylaminoethanol and 63.5 parts of water were added with sufficient stirring to obtain an aqueous resin solution (B1) having a solid content of 40%.

Production Example 2 A temperature control regulator was placed in a separable four-necked flask.
Attach a cooling pipe and stirrer, and install butyl carbitol 6
After charging 5.7 parts, the temperature was raised to about 90 ° C., and the inside of the reaction vessel was purged with nitrogen. Then, 30 parts of methacrylic acid, 25 parts of ethyl acrylate, 30 parts of butyl acrylate, 10 parts of butyl methacrylate, and 10 parts of 4-hydroxybutyl 5 parts of acrylate and 1 part of 2,2'-azobisisobutyronitrile were added dropwise over 2 hours. After completion of the dropwise addition, the reaction was continued for another 3 hours to obtain a resin having a Tg of 29 ° C. After cooling, 24.8 parts of dimethylaminoethanol and 58.5 parts of water were added with sufficient stirring, and an aqueous resin solution having a solid content of 40% (B
2) was obtained.

Production Example 3 A temperature control regulator was placed in a separable four-necked flask.
Attach a cooling pipe and stirrer, and install butyl carbitol 6
After charging 5.7 parts, the temperature was raised to about 90 ° C., and the inside of the reaction vessel was purged with nitrogen.
Parts, methyl methacrylate 5 parts, ethyl acrylate 1
5 parts, 35 parts of butyl acrylate, 30 parts of 2-hydroxyethyl methacrylate, and 1 part of 2,2′-azobisisobutyronitrile were added dropwise over 2 hours. After dropping,
The reaction was further continued for 3 hours to obtain a resin having a Tg of 16 ° C. After cooling, 4.9 parts of dimethylaminoethanol and 78.4 of water
The mixture was added with sufficient stirring to obtain an aqueous resin solution (B3) having a solid content of 40%.

Production Example 4 A temperature control regulator was placed in a separable four-necked flask.
Attach a cooling pipe and stirrer, and install butyl carbitol 6
After charging 5.7 parts, the temperature was raised to about 90 ° C., and the inside of the reaction vessel was purged with nitrogen. Then, 10 parts of acrylic acid, 30 parts of ethyl acrylate, 50 parts of butyl acrylate, 10 parts of 2-hydroxyethyl methacrylate were added from a dropping tube. 1 part of 2,2'-azobisisobutyronitrile was added dropwise over 2 hours. After the completion of the dropwise addition, the reaction was continued for another 3 hours to obtain a resin having a Tg of -18 ° C. After cooling, dimethylaminoethanol 9.9
And 73.4 parts of water were added with sufficient stirring to obtain an aqueous resin solution (B4) having a solid content of 40%.

Production Example 5 A temperature control regulator was placed in a separable four-necked flask.
Attach a cooling pipe and stirrer, and install butyl carbitol 6
After charging 5.7 parts, the temperature was raised to about 90 ° C., and the inside of the reaction vessel was replaced with nitrogen, and then 20 parts of acrylic acid, 30 parts of ethyl acrylate, 10 parts of butyl acrylate, 40 parts of styrene, 2,2′- One part of azobisisobutyronitrile was added dropwise over 2 hours. After the completion of the dropwise addition, the reaction was continued for another 3 hours to obtain a resin having a Tg of 41 ° C. After cooling, 19.8 parts of dimethylaminoethanol and 63.5 parts of water were added with sufficient stirring, and an aqueous resin solution (B5) having a solid content of 40% was added.
I got

Example 1 Step (1) The following mixture was treated with two rolls 20 times to obtain a solid content of 88%.
Of solid chips were obtained.

Pigment (CI Pigment Blue 15: 1) 10.0 parts Aqueous resin solution (B1) 6.0 parts Deionized water 0.2 parts Butyl carbitol 0.2 parts Step (2) Obtained The chips were dispersed in the following composition for 60 minutes using a high-speed mixer.

Solid chip 14.1 parts Dimethylaminoethanol 0.3 parts Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After re-dispersion, an aqueous paint having the following composition was prepared.

Redispersion 41.4 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 7.4 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

As shown in Table 1, the dispersion particle size and the coating film gloss of the present invention were superior to those of the comparative examples.

Example 2 Step (1) The following mixture was treated with a two-roll mill 20 times to obtain a solid content of 88.
% Solid chips were obtained.

Pigment (CI Pigment Blue 15: 1) 9.5 parts Organic dye derivative a * 0.5 part Aqueous resin solution (B1) 6.0 parts Deionized water 0.2 parts Butyl carbitol 0. 2 parts * organic dye derivative _{a CuPc-SO 2 NH (CH} 2) 3 N (C 2 H 5) 2 CuPc; of copper phthalocyanine radical step (2) resulting chips following composition, 60 a high-speed mixer Dispersed for minutes.

Solid chip 14.1 parts Dimethylaminoethanol 0.3 parts Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After redispersion, an aqueous paint was prepared with the following composition.

Redispersion 41.4 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 7.4 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

As shown in Table 1, the dispersion particle size and coating film gloss of the present invention were superior to those of the comparative examples.

Comparative Example 1 The following mixture was dispersed using a sand mill.

Pigment (CI Pigment Blue 15: 1) 10.0 parts Aqueous resin solution (B1) 6.0 parts Ion-exchanged water 25.4 parts After dispersion, an aqueous paint having the following composition was prepared.

Dispersion 41.4 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Deionized water 7.4 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, 98% solids) The water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes.

Comparative Example 2 Step (1) The following mixture was treated with two rolls 20 times to obtain a solid content of 88.
% Solid chips were obtained.

Pigment (CI Pigment Blue 15: 1) 10.0 parts Aqueous resin solution (B4) 6.0 parts Ion-exchanged water 0.2 parts Butyl carbitol 0.2 parts Step (2) Obtained The chips were dispersed in the following composition for 60 minutes using a high-speed mixer.

Solid chip 14.1 parts Dimethylaminoethanol 0.3 parts Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After dispersion, a water-based paint having the following composition was prepared.

Redispersion 41.4 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 7.4 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

Comparative Example 3 Step (1) The following mixture was treated 20 times with two rolls to obtain a solid content of 88.
% Solid chips were obtained.

Pigment (CI Pigment Blue 15: 1) 10.0 parts Aqueous resin solution (B5) 6.0 parts Deionized water 0.2 parts Butyl carbitol 0.2 parts Step (2) Obtained The chips were dispersed in the following composition for 60 minutes using a high-speed mixer.

Solid chip 14.1 parts Dimethylaminoethanol 0.3 parts Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After dispersion, a water-based paint having the following composition was prepared.

Redispersion 41.4 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 7.4 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98 %) 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.

Example 3 Step (1) The following mixture was treated with two rolls 20 times to obtain a solid content of 86.
% Solid chips were obtained.

Pigment (CI Pigment Violet 19) 9.7 parts Organic dye compound b * 0.3 parts Aqueous resin solution (B1) 8.0 parts Ion-exchanged water 0.2 parts Butyl carbitol 0.2 parts * Organic dye compound b

[0075]

Embedded image Step (2) The obtained chips were dispersed in the following composition for 60 minutes using a high-speed mixer.

Solid chip 15.3 parts Dimethylaminoethanol 0.3 part Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After redispersion, an aqueous paint was prepared with the following composition.

Redispersed material 42.6 parts Aqueous resin solution (B2) 62.0 parts Cymel 303 * 12.2 parts Ion exchange water 8.2 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

As shown in Table 1, the dispersion particle size and coating film gloss of the present invention were superior to those of the comparative examples.

Comparative Example 4 The following mixture was dispersed using a sand mill.

Pigment (CI Pigment Violet 19) 10.0 parts Aqueous resin solution (B1) 8.0 parts Ion-exchanged water 24.6 parts After dispersion, an aqueous paint having the following composition was prepared.

Dispersion 42.6 parts Aqueous resin solution (B2) 62.0 parts Cymel 303 * 12.2 parts Ion exchange water 8.2 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, 98% solids) The water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes.

Example 4 Step (1) The following mixture was treated 20 times with two rolls to obtain a solid content of 85
% Solid chips were obtained.

Pigment (CI Pigment Red 254) 9.5 parts Organic dye compound b * 0.5 part Aqueous resin solution (B1) 10.0 parts Deionized water 0.2 parts Butyl carbitol 0.2 parts * Organic dye compound b

[0085]

Embedded image Step (2) The obtained chips were dispersed in the following composition for 60 minutes using a high-speed mixer. Solid chip 16.5 parts Dimethylaminoethanol 0.4 parts Butyl carbitol 2.0 parts Deionized water 25.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After the redispersion, an aqueous paint having the following composition was prepared.

Redispersion 43.9 parts Aqueous resin solution (B2) 60.0 parts Cymel 303 12.2 parts Ion-exchanged water 8.9 parts The obtained aqueous paint was spread on a PET film with a 4 mil film applicator. Colored and baked at 140 ° C. for 30 minutes.

As shown in Table 1, the dispersion particle size and coating film gloss of the present invention were superior to those of the comparative examples.

Comparative Example 5 The following mixture was dispersed using a sand mill.

Pigment (CI Pigment Red 254) 10.0 parts Aqueous resin solution (B1) 10.0 parts Ion-exchanged water 23.9 parts After dispersion, an aqueous paint having the following composition was prepared.

Dispersion 43.9 parts Aqueous resin solution (B2) 60.0 parts Cymel 303 * 12.2 parts Ion exchange water 8.9 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98% The water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes.

Example 5 Step (1) The following mixture was treated with two rolls 20 times to obtain a solid matter of 91%.
% Solid chips were obtained.

Pigment (CI Pigment Red 177) 9.9 parts Organic dye compound c * 0.1 parts Aqueous resin solution (B2) 7.5 parts Ion exchange water 0.2 parts Butyl carbitol 0.2 parts * Organic dye compound c

[0094]

Embedded image Step (2) The obtained chips were dispersed in the following composition for 60 minutes using a high-speed mixer.

Solid chip 14.3 parts Dimethylaminoethanol 0.2 parts Butyl carbitol 2.2 parts Deionized water 30.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After the redispersion, an aqueous paint having the following composition was prepared.

Redispersion 46.7 parts Aqueous resin solution (B2) 62.5 parts Cymel 303 * 12.2 parts Ion-exchanged water 3.6 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

As shown in Table 1, the dispersion particle size and the gloss of the coating film according to the present invention were superior to those of the comparative examples.

Comparative Example 6 The following mixture was dispersed using a sand mill.

Pigment (CI Pigment Red 177) 10.0 parts Aqueous resin solution (B2) 7.5 parts Ion-exchanged water 29.2 parts After dispersion, an aqueous paint having the following composition was prepared.

Dispersion 46.7 parts Aqueous resin solution (B2) 62.5 parts Cymel 303 * 12.2 parts Ion exchanged water 3.6 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, 98% solids) The water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes.

Example 6 Step (1) The following mixture was treated with two rolls 20 times to obtain a solid matter of 93%.
% Solid chips were obtained.

Pigment (CI Pigment Green 36) 9.7 parts Organic dye compound a * 0.3 parts Aqueous resin solution (B3) 6.0 parts Ion-exchanged water 0.2 parts Butyl carbitol 0.2 parts * organic dye compound _{a CuPc-SO 2 NH (CH} 2) 3 N (C 2 H 5) 2 CuPc; copper phthalocyanine residue step (2) resulting chip by the following composition for 60 minutes at a high speed mixer dispersion did.

Solid chips 13.3 parts Dimethylaminoethanol 0.2 parts Butyl carbitol 2.0 parts Deionized water 30.0 parts Step (3) The above dispersion was redispersed using a sand mill.

After re-dispersion, an aqueous paint having the following composition was prepared.

Redispersion 45.5 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 3.3 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, solid content 98) %) 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.

As shown in Table 1, the dispersion particle size and the gloss of the coating film according to the present invention were superior to those of the comparative examples.

Comparative Example 7 The following mixture was dispersed using a sand mill.

Pigment (CI Pigment Green 36) 10.0 parts Aqueous resin solution (B3) 6.0 parts Ion-exchanged water 29.5 parts After dispersion, an aqueous paint having the following composition was prepared.

Dispersion 45.5 parts Aqueous resin solution (B2) 64.0 parts Cymel 303 * 12.2 parts Ion exchange water 3.3 parts * Cymel 303 (Methylated melamine resin manufactured by Mitsui Cytec, 98% solids) The water-based paint was spread on a PET film with a 4 mil film applicator and baked at 140 ° C. for 30 minutes.

[0111]

[Table 1]

[0112]

According to the present invention, there is provided an aqueous pigment dispersion used for an aqueous coating composition such as ink and paint,
The suitability for use, such as non-aggregation and fluidity, as well as the sharpness and gloss of the color tone of the coated product were significantly improved.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/00 C09D 133/00 11/00 C08J 3/03 CEY 133/00 (72) Inventor Masashi Itabashi Tokyo 2-13-13 Kyobashi, Chuo-ku, Tokyo F-term (reference) in Toyo Ink Manufacturing Co., Ltd. CC01 CC13 CC15 CC16 CC17 CC23 CC24 CC26 DD23 EE08 EE28 EE43 FF15 4J038 EA011 GA03 KA08 KA15 MA08 MA10 4J039 AD03 AD06 AD08 AD09 AD10 AD11 AD13 AD14 AD20 BA04 BA13 BA23 BA31 BA34 BA35 BA36 BA37 BC17 BC19 BC33 BC35 BC36 BC35 BC36 BC35 BC35 BC36 BC35 BC36 BC35 BC35 BC35 BC36 BE12 CA06 DA02 DA05 DA08 EA33 EA44 EA45

Claims (7)

[Claims] (A) a pigment, and (B) (a) an ethylenically unsaturated monomer having at least one carboxylic acid group in a molecule, and (b) an ethylenic unsaturated monomer having at least one hydroxyl group in a molecule. Step (1) of kneading a resin having a Tg of 0 ° C. or higher obtained by copolymerizing an ethylenically unsaturated monomer composition containing an unsaturated monomer with a roll to form a solid chip, and An aqueous pigment dispersion obtained by the step (2) of dispersing in an aqueous medium. 2. The aqueous pigment dispersion according to claim 1, wherein the step (1) is carried out in the presence of (C) water and / or a water-miscible organic solvent. 3. The aqueous pigment dispersion according to claim 1, which is obtained through a step (3) in which the dispersion obtained in the step (2) is further dispersed by a media type disperser. 4. The method according to claim 1, wherein the step (1) or (2) is performed in the presence of a basic organic dye derivative.
3. The aqueous pigment dispersion according to any one of 3. 5. The aqueous pigment dispersion according to claim 1, wherein the step (2) is performed in the presence of an alkali compound. 6. A pigment (A), (B) (a) an ethylenically unsaturated monomer having at least one carboxylic acid group in the molecule, and (b) an ethylenically unsaturated monomer having at least one hydroxyl group in the molecule. Tg obtained by copolymerizing an ethylenically unsaturated monomer composition containing a saturated monomer
A method for producing an aqueous pigment dispersion, comprising: a step (1) of kneading a resin at 0 ° C. or higher by a roll to form a solid chip, and a step (2) of dispersing the solid chip in an aqueous medium. 7. An aqueous coating composition comprising the aqueous pigment dispersion according to claim 1.