JP3132314B2 - Method for producing aqueous pigment dispersion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous pigment dispersion which, when used in an aqueous paint or an aqueous ink, has excellent gloss and coloring power of a film, and has good fluidity and storage stability.

[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. Water-based paints and water-based inks are required to have properties such as fluidity, storage stability, film gloss, sharpness, and coloring power, as in the case of oiliness. However, most pigments are remarkably inferior in pigment dispersibility and the like to aqueous vehicles, so that satisfactory properties cannot be obtained by ordinary dispersing methods. Therefore, the use of various additives, such as a pigment dispersing resin for water or a surfactant, has been conventionally studied, but it satisfies all the above characteristics and is comparable to existing high quality oil-based paints or oil-based inks. Water-based paints and water-based inks have not been obtained. That is, the use of a certain kind of aqueous dispersing resin improves the gloss, sharpness, coloring power, etc. of the film immediately after dispersion to some extent, but impairs fluidity, increases viscosity or gels over time, and physical properties of the film. There are practically fatal drawbacks such as adversely affecting the performance.

[0003]

As a method for solving the above-mentioned drawbacks, the present inventors have proposed an aqueous pigment dispersion,
When neutralizing an acidic functional group in a resin with an amine, it was found that it is effective to use a resin using an organic dye compound represented by the general formula (1) as a neutralizing agent as a resin for pigment dispersion. The invention has been completed.

[0004]

SUMMARY OF THE INVENTION The present invention provides a
50-80% by weight of lylic acid alkyl ester, carboxylic acid
Contained monomer 5 to 30% by weight and other monomers 0 to 20
Acrylic copolymer resin consisting of
Step of neutralizing with the organic dye compound represented by (1)
And neutralization of the acrylic copolymer-based resin obtained in the above process
Dispersing the pigment in an aqueous medium in the presence of
A process for producing an aqueous pigment dispersion.

The general formula (1)

Embedded image Wherein, Q; organic pigment residue or heterocyclic residue X; direct bond, -NH -, - CONH-Y 2 -, - SO
₂ NH-Y ₂ - or -CH ₂ NHCOCH ₂ NH-Y
_2- (Y ₂ ; an alkylene group or an arylene group which may have a substituent) Y ₁ ; —NH— or —O—Z; a hydroxyl group, an alkoxy group or the general formula (2)

Formula (2)

Embedded image (Y ₃ ; —NH— or —O—), or n = 1
In the case of, -NH-XQ may be R ₁ , R ₂ ; each independently may be a substituted or unsubstituted alkyl group or at least a hetero ring may be formed by R ₁ and R ₂ . m; an integer of 1 to 6 n; an integer of 1 to 4

A method for producing the organic dye compound of the present invention represented by the general formula (1) is described in JP-A-61-246261. That is, a commercially available dye or pigment is first subjected to chlorosulfonation and chloroacetic acid amide methylation according to a conventional method. Next, the organic dye compound of the present invention can be obtained by reacting with an amine represented by the following general formula (3).

General formula (3)

Embedded image In the general formula (3), Y ₁ ; —NH— or —O—Y ₂ ; an alkylene group or an arylene group optionally having a substituent Z; a hydroxyl group, an alkoxy group, or a general formula (2) R ₁ , R ₂ ; each independently may be a substituted or unsubstituted alkyl group or at least a heterocycle with R ₁ and R ₂ . m; an integer from 1 to 6

The organic dye residue represented by Q in the general formula (1) includes phthalocyanine, insoluble azo, azo lake, anthraquinone, quinacridone, dioxazine, diketopyrrolopyrrole, anthrapyrimidine, Anthanthrone, indanthrone, flavanthrone, perinone, thioindigo and the like. These organic dyes may be used singly or in combination of two or more, but it is industrially more advantageous to use one having a hue close to the pigment used.

The heterocyclic residue represented by Q in the general formula (1) includes, for example, thiophene, furan, xanthene, pyrrole, imidazole, isoindoline,
Isoindolinone, benzimidazolone, indole,
Examples include quinoline, carbazole, acridine, acridone, anthraquinone and the like. When Q is a heterocyclic residue, the organic dye compound represented by the general formula (1) is colorless or hardly colored, which is desirable in terms of versatility.

X in the general formula (1) is a direct bond, -N
H-, -CONH-Y_Two-, -SO _TwoNH-Y_Two−,
Or -CH_TwoNHCOCH_TwoNH-Y_Two− (Y_Two; Place
An alkylene group or an arylene group which may have a substituent)
A bonding group selected from

In the general formula (1), Y ₁ is a bonding group selected from —NH— and —O—.

Z in the general formula (1) is a hydroxyl group, an alkoxy group or a bonding group selected from the following general formula (2), and is preferably the general formula (2).

General formula (2)

Embedded image (Y ₃ ; —NH— or —O—), or n = 1
In the case of -NH-XX may be

R ₁ in the general formulas (1) and (2),
R ₂ may be each independently a substituted or unsubstituted alkyl group, or R ₁ and R ₂ may form at least a heterocyclic ring, and an unsubstituted alkyl group is preferable. These alkyl groups may be branched up to a maximum of 18 carbon atoms, and lower alkyl groups such as a methyl group, an ethyl group, a propyl group and a butyl group are particularly preferred.

In the general formulas (1) and (2), m is 1
An integer of 1 to 6, and n is an integer of 1 to 4.

The aqueous resin of the present invention is preferably an acrylic copolymer-based water-dispersible resin or a water-soluble resin.

This acrylic copolymer-based resin is (meth)
Acrylic acid alkyl ester 50-80% by weight, acrylic acid, methacrylic acid, maleic acid, carboxylic acid-containing monomer such as itaconic acid 5-30% by weight and other monomers 0
Weight average molecular weight of 5,000 to 30,000 obtained by emulsion polymerization or solution polymerization in a water-soluble solvent.
0, a resin having an acid value of 1 to 200.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, and isopropyl (meth) acrylate. , (Meth) acrylic isobutyl, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, lauryl (meth) acrylate and the like.

The other monomers include 2-hydroxyethyl (meth) acrylate and 2 (meth) acrylic acid.
-Hydroxypropyl, acrylamide, N-methylolacrylamide, diacetoneacrylamide, glycidyl (meth) acrylate, styrene, vinyltoluene, vinyl acetate, acrylonitrile, vinyl alcohol, ethylene and the like.

The aqueous medium of the aqueous acrylic resin may be water alone, but depending on the case, an alcoholic solvent such as ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butanol or ethylene glycol or diethylene glycol. Water-miscible organic solvents such as mono- or dialkyl ethers can be incorporated up to 50% by weight in the aqueous medium.

Examples of the pigment of the present invention include phthalocyanine pigments, insoluble azo pigments, azo lake pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments,
Diketopyrrolopyrrole pigment, anthrapyridine pigment, anthanthrone pigment, indanthrone pigment, flavanthrone pigment, perinone pigment, perylene pigment, thioindigo pigment, carbon black, iron oxide, lead white, lead red, ultramarine, navy blue, cobalt oxide , Titanium dioxide, titanium dioxide coated mica, strontium chromate, titanium yellow,
Examples include titanium black, zinc chromate, iron black, molybdenum red, molybdenum white, lithopone, emerald green, cadmium yellow, cadmium red, and cobalt blue.

The aqueous pigment dispersion of the present invention is obtained through the following two-step procedure. That is, the first step is a step of producing an aqueous pigment dispersing resin, and the second step is a step of dispersing a pigment using the pigment dispersing resin.

The aqueous pigment dispersing resin is obtained by neutralizing a carboxyl group, which is an acidic functional group, in the above-mentioned aqueous acrylic copolymer-based resin with an organic dye compound represented by the general formula (1).

The procedure of neutralization with an organic dye compound having a basic group at the terminal is as follows.
This aqueous acrylic copolymer-based resin is heated to lower the viscosity, and the mixture is neutralized by adding an organic dye compound represented by the general formula (1) while stirring with a disper. As the method of addition, the organic dye compound represented by the general formula (1) may be used in the form of a dried powder, or may be mixed with water or the above-mentioned water-miscible organic solvent to obtain a solid content of 30 to 95%. It is more effective to use it as a slurry. At this time, when the organic dye compound represented by the general formula (1) is added, the viscosity of the system is remarkably lowered, and it can be confirmed that the carboxyl group of the resin is neutralized. In addition, it can be confirmed that the neutralized resin is easily dissolved because the resin is easily dissolved. The neutralization rate of the carboxyl group by the organic dye compound is 50 to 120%, preferably 70 to 100%. If it is lower than 50%, it is difficult to make the resin soluble in water. After neutralization, the mixture is diluted with water or the above-mentioned water-miscible organic solvent to a viscosity that allows easy operation. The PH at that time is 7.5 to 7.5
9

In order to obtain an aqueous pigment dispersion using the pigment dispersing resin solution neutralized with the organic dye compound having a basic group in this manner, 100 parts by weight of the pigment is mixed with a solid content of 5%.
It is desirable to disperse the pigment-dispersed resin solution having -100 parts by weight, preferably 5-50 parts by weight. If the solid content is less than 5 parts by weight, the pigment is insufficiently wet and the dispersion is poor. Even if the solid content is more than 100 parts by weight, the effect of the used amount cannot be obtained.

When used as a concentrated dispersion of a water-based paint or water-based ink, if necessary, after the dispersion is completed, the solid content of the water-based resin may be 5 to 300 parts by weight with respect to 100 parts by weight of the pigment. Add resin solution.

In order to prepare a water-based paint and a water-based ink, various water-based resins and a curing agent such as melamine shown below are further added, and the solid content of the resin is 1 to 100 parts by weight of the pigment.
It is preferable that the amount be from 00 to 700 parts by weight.

As the concentrated aqueous dispersion of the water-based paint / water-based ink or the diluted water-based resin added to obtain the water-based paint / water-based ink, the above-described pigment-dispersing resin neutralized with an organic dye compound may be used. Alternatively, an aqueous acrylic copolymer-based resin solution neutralized with an amine compound such as triethylamine, ethanolamine, dimethylethanolamine, diethanolamine, triethanolamine, or the like, in whole or in part, may be used instead of the organic dye compound. Further, an aqueous resin other than the acrylic copolymer system, for example, a water-dispersible resin or a water-soluble resin such as a styrene-acrylic acid copolymer system, a styrene-maleic acid copolymer system, an alkyd system, an epoxy system, a polyester system, or a urethane system is used. be able to.

The aqueous pigment dispersion of the present invention includes a dispersion before dilution, a concentrated dispersion of an aqueous paint and an aqueous ink, and an aqueous paint and an aqueous ink.

【Example】

Example 1 The following phthalocyanine-based organic dye compound (a) was used as a neutralizing agent, and the weight-average molecular weight was 2,500 when the neutralization ratio was 80%.
Acrylic resin having an acid value of 60 is used as a pigment dispersion resin. 12.5 parts of this acrylic resin solution (solid content 20%), CIPi
gment Blue 15: 1 (phthalocyanine pigment) 10 parts, ion exchange water 20 parts, and 3 mm φ alumina beads 150 parts
The mixture was placed in a ml glass container and dispersed with a paint conditioner for 3 hours. 37.5 parts of an acrylic resin and a methylated melamine resin (trade name Cymel 303 Mitsui Cyanamid Co., Ltd.) having the same contents as the above pigment dispersion resin except that dimethylethanolamine was used instead of the following organic dye compound (a) as a neutralizing agent Was diluted with 4.3 parts to obtain an aqueous paint. When the viscosity of this water-based paint was measured by a B-type rotational viscometer, excellent fluidity of a TI value (6 rpm viscosity / 60 rpm viscosity) of 1.1 was obtained. The water-based paint was spread on a PET film using a 4 mil film applicator, and heated at 140 ° C.
After baking for 30 minutes, excellent film gloss was obtained. Gloss was measured at 20 ° gloss using a digital variable-angle gloss meter and found to be 72%.

Organic dye compound (a) (phthalocyanine)

Embedded image

Example 2 Except that the degree of neutralization of the pigment-dispersed resin was changed to 120%, a paint was formed in the same manner as in Example 1, and the resultant was spread on a PET film and baked. Gloss is obtained and T
The I value was 1.1 and the 20 ° gloss was 68%.

Example 3 A paint was prepared in the same manner as in Example 1 except that the pigment-dispersed resin was also used as a diluting acrylic resin, and the resultant was spread on a PET film and baked. As a result, excellent fluidity and excellent film gloss were obtained. Was obtained, the TI value was 1.2 and the 20 ° gloss was 70%.

Examples 4 to 14 When pigment dispersing resins using the following organic dye compounds (b) to (i) as neutralizing agents were used for various pigments according to Example 1, As in Example 1, excellent film gloss was obtained. The results are shown in Tables 1 and 2.

Organic dye compound (b) (phthalocyanine)

Embedded image

Organic dye compound (c) (phthalocyanine)

Embedded image

Organic dye compound (d) (quinacridone type)

Embedded image

Organic dye compound (e) (dioxazine type)

Embedded image

Organic dye compound (f) (anthraquinone type)

Embedded image

Organic dye compound (g) (perylene type)

Embedded image

Organic dye compound (h) (diaminoanthraquinone type)

Embedded image

Organic dye compound (i) (benzimidazolone type)

Embedded image

Comparative Examples 1 to 9 The pigments used in Examples 1 to 14 were dispersed in an acrylic resin neutralized with dimethylethanolamine, formed into a paint, spread and baked to obtain organic dye compounds (a) to (i). ) Was inferior in fluidity and gloss as compared with the case where) was used as a neutralizing agent. The results are shown in Tables 1 and 2.

[0045]

[Table 1]

[0046]

[Table 2]

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ identification code FI C09D 17/00 C09D 17/00 // C08F 8/44 C08F 8/44 (58) Fields surveyed (Int.Cl. ⁷ , DB Name) C08L 1/00-101/16 C08K 3/00-13/08 C09D 17/00 C09B 67/20 C09B 67/46 C09B 69/10

Claims (2)

(57) [Claims] 1. An alkyl (meth) acrylate 5
0 to 80% by weight, 5 to 30% by weight of carboxylic acid-containing monomer
And other acrylic monomers comprising 0 to 20% by weight.
Conversion of polymer resin to organic dye represented by the following general formula (1)
Neutralizing with the compound and the acrylic
Pigment in aqueous medium in the presence of neutralized copolymer resin
Dispersing into the aqueous pigment component,
How to make powder. General formula (1) Wherein, Q; organic pigment residue or heterocyclic residue X; direct bond, -NH -, - CONH-Y 2 -, - SO 2
NH-Y ₂ - or _{-CH 2 NHCOCH 2 NH-Y 2} -
(Y ₂ ; an alkylene group or an arylene group which may have a substituent) Y ₁ ; —NH— or —O—Z; a hydroxyl group, an alkoxy group or a general formula (2) (Y _3; -NH - or is - O-), or n = 1 and a may optionally be -NH-X-Q. R ₁ and R ₂ ; each independently may be a substituted or unsubstituted alkyl group or at least a heterocyclic ring formed by R ₁ and R ₂ ; m; an integer of 1 to 6 n; an integer of 1 to 4 2. 100 parts by weight of a pigment and an acrylic copolymer
The method for producing an aqueous pigment dispersion according to claim 1, comprising 5 to 700 parts by weight of the system resin .