JPH0848890A - Resin for dispersing aqueous pigment and aqueous pigment dispersant using the same - Google Patents

Abstract

PURPOSE:To obtain the subject resin excellent in gloss of film and coloring force and capable of providing an aqueous pigment dispersant having good fluidity and storage stability by neutralizing an aqueous resin with a neutralizing agent consisting of a specific organic compound. CONSTITUTION:This resin is obtained by neutralizing an aqueous resin with a neutralizing agent mainly comprising an organic pigment compound containing a terminal basic group of formula I [Q is an organic pigment residue or a heterocyclic residue; X is a direct bond, NH, etc.; Y1 is NH or O; Z is OH, an alkoxy, etc.; R1 and R2 are each a (substituted)alkyl; (m) is 1-6; (n) is 1-4]. An acrylic copolymer-based resin having 5000-300000 weight-average molecular weight and 1-200 acid value and obtained by subjecting a monomer mixture comprising 50-80wt.% of a (meth)acrylic acid alkyl ester, 5-30wt.% of a carboxylic acid-containing monomer such as (meth)acrylic acid and 0-20wt.% of other monomer to emulsion polymerization or solution polymerization in a water-soluble solvent is preferably used as the aqueous resin.

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 tinting strength 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 the increasing needs such as 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 tinting strength as in the case of oil-based paints. However, most of the pigments have extremely poor suitability in terms of pigment dispersibility and the like with respect to the aqueous vehicle, so that satisfactory characteristics cannot be obtained by a usual dispersion method. Therefore, various additives such as a water-based pigment-dispersed resin and a surfactant have been studied in the past, but they satisfy all of the above characteristics and are comparable to existing oil-based paints or oil-based inks having high quality. Aqueous paints and inks have not been obtained. That is, the use of a certain type of aqueous dispersion resin improves the gloss, sharpness, and coloring power of the film immediately after dispersion to some extent, but the fluidity is impaired, the viscosity increases or gels over time, and the physical properties of the film. There was a practically fatal defect such as adversely affecting

[0003]

As a method for solving the above-mentioned drawbacks, the present inventor has found that in an aqueous pigment dispersion,
When neutralizing an acidic functional group in a resin with an amine, it has been 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 pigment dispersion resin. The invention was completed.

[0004]

The present invention is characterized by being neutralized with a neutralizing agent containing an organic dye compound having a basic group at the terminal represented by the general formula (1) as a main component. And a resin for dispersing an aqueous pigment, wherein the pigment is dispersed using the resin.

General formula (1)

[Chemical 3] 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 optionally substituted alkylene group or an arylene group) Y _1; -NH- or -O- Z; a hydroxyl group, an alkoxy group or general formula (2)

General formula (2)

[Chemical 4] (Y ₃ ; -NH-, or -O-), or n = 1
In the case of -NH-X-Q may be R < ₁ >, R < ₂ >; each independently a substituted or unsubstituted alkyl group or R < ₁ > and R < ₂ > may form at least a heterocycle. m; an integer of 1 to 6 n; an integer of 1 to 4

The 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, generally commercially available dyes or pigments are first chlorosulfonated and chloroacetic acid amidomethylated 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 general formula (3).

General formula (3)

Embedded image Formula (3) wherein, Y _1; -NH- or -O- Y _2; an optionally substituted alkylene group or an arylene group Z; a hydroxyl group, an alkoxy group or general formula (2) R _1, R ₂ ; each independently, a substituted or unsubstituted alkyl group or R ₁ and R ₂ may form at least a heterocycle. m; integer from 1 to 6

Examples of the organic dye residue represented by Q in the general formula (1) include phthalocyanine type, insoluble azo type, azo lake type, anthraquinone type, quinacridone type, dioxazine type, diketopyrrolopyrrole type, anthrapyrimidine type, Ansanthurones, indanthrone, flavanthrone, perinone, thioindigo, etc. Any of these organic dyes may be used alone or in combination, but it is industrially advantageous to use one having a hue close to that of the pigment used.

Examples of the heterocyclic residue represented by Q in the general formula (1) include thiophene, furan, xanthene, pyrrole, imidazole, isoindoline,
Isoindolinone, benzimidazolone, indole,
Examples include quinoline, carbazole, acridine, acridone, and anthraquinone. 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-Y₂-, -SO ₂NH-Y₂-,
Or -CH₂NHCOCH₂NH-Y₂-(Y₂;
(Alkylene group or arylene group which may have a substituent)
Is a bonding group selected from

Y ₁ in the general formula (1) is a bonding group selected from —NH— or —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 preferably the general formula (2).

General formula (2)

[Chemical 6] (Y ₃ ; -NH-, or -O-), or n = 1
In the case of, it may be -NH-X-Q.

R ₁ in the general formulas (1) and (2),
R _2's may each independently be a substituted or unsubstituted alkyl group, or R ₁ and R ₂ may form at least a heterocycle, and an unsubstituted alkyl group is preferable. These alkyl groups may be branched in a range of up to 18 carbon atoms, and lower alkyl groups such as methyl group, ethyl group, propyl group and butyl group are particularly preferable.

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

As the water-based resin of the present invention, acrylic copolymer system, styrene-acrylic acid copolymer system, styrene-maleic acid copolymer system, alkyd system, epoxy system,
Examples thereof include water-soluble resins or water-soluble resins such as polyester-based and urethane-based resins, and water-soluble resins or water-soluble resins based on acrylic copolymers are particularly preferable.

This acrylic copolymer resin is (meth)
Acrylic acid alkyl ester 50 to 80% by weight, acrylic acid, methacrylic acid, maleic acid, itaconic acid and other carboxylic acid-containing monomers 5 to 30% by weight and other monomers 0
~ 20% by weight obtained by emulsion polymerization or solution polymerization in a water-soluble solvent, weight average molecular weight 5,000 to 30,000
A resin having an acid value of 0 and an acid value of 1 to 200.

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

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

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

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

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

The resin for dispersing an aqueous pigment is obtained by neutralizing the carboxyl group which is an acidic functional group in the above-mentioned aqueous acrylic copolymer 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 end is as follows.
This aqueous acrylic copolymer resin is heated to lower the viscosity, and the organic dye compound represented by the general formula (1) is added to the resin for neutralization while stirring with a disper. As a method of addition, the organic dye compound represented by the general formula (1) may be used in a dry powder form, or water or the water-miscible organic solvent may be used to obtain a solid content of 30 to 95%. It is more effective when used 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 reduced, and it can be confirmed that the carboxyl groups of the resin are neutralized. Also, it can be confirmed that the resin was neutralized because the resin after the neutralization was easily dissolved. The carboxyl group neutralization rate by the organic dye compound is 50 to 120%, and preferably 70 to 100%. If it is less than 50%, it is difficult to solubilize the resin, and if it is used more than 120%, the effect of the amount used cannot be obtained. After neutralization, water or the water-miscible organic solvent described above is used to dilute the viscosity to make it easy to work. Also, the PH at that time is 7.5.
9

In order to obtain an aqueous pigment dispersion by using the pigment dispersion resin solution thus neutralized with the organic dye compound having a basic group, 100 parts by weight of the pigment is added to the solid content of 5 parts by weight.
It is desirable to disperse with this pigment-dispersed resin solution having ˜100 parts by weight, preferably 5-50 parts by weight. When the solid content is less than 5 parts by weight, wetting of the pigment is insufficient and dispersion becomes poor. Even if the solid content is more than 100 parts by weight, the effect of the used amount cannot be obtained.

When it is used as a concentrated dispersion of an aqueous paint or an aqueous ink, an aqueous solution is optionally added after the dispersion so that the solid content of the aqueous resin is 5 to 300 parts by weight with respect to 100 parts by weight of the pigment. Add resin solution.

To prepare water-based paints and water-based inks, various kinds of water-based resins and curing agents such as melamine shown below are further added, and the solid content of the resin is 1 per 100 parts by weight of the pigment.
It is preferable that the amount is 100 to 700 parts by weight.

As the concentrated 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-mentioned pigment-dispersing resin neutralized with the organic dye compound may be used. Instead of the organic dye compound, the whole amount or a part thereof may be an aqueous acrylic copolymer resin solution neutralized with an amine compound such as triethylamine, ethanolamine, dimethylethanolamine, diethanolamine or triethanolamine. Further, an aqueous resin other than the acrylic copolymer system, for example, a styrene-acrylic acid copolymer system, a styrene-maleic acid copolymer system, an alkyd-based, epoxy-based, polyester-based, urethane-based water-dispersed resin or water-soluble resin is used. be able to.

The aqueous pigment dispersion of the present invention includes a dispersion before dilution, a concentrated dispersion of a water-based paint / water-based ink, and a water-based paint / water-based ink.

【Example】

Example 1 Using the following phthalocyanine-based organic dye compound (a) as a neutralizing agent, a weight average molecular weight of 2500 was obtained with a neutralization rate of 80%.
An acrylic resin having an acid value of 60 and 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-exchanged water 20 parts, and 3 mmφ alumina beads 150 parts 225
It was put in a glass container of ml and dispersed for 3 hours with a paint conditioner. 37.5 parts of an acrylic resin having the same content as the above pigment dispersion resin and a methylated melamine resin (trade name: Cymel 303 Mitsui Cyanamid Co., Ltd.) except that dimethylethanolamine was used as a neutralizing agent instead of the following organic dye compound (a) The product was diluted with 4.3 parts to obtain a water-based paint. When the viscosity of this water-based paint was measured by a B-type rotary viscometer, excellent fluidity with a TI value (6 rpm viscosity / 60 rpm viscosity) of 1.1 was obtained. Also, this water-based paint was spread on PET film with a 4 mil film applicator, and the temperature was increased to 140 ° C.
After baking for 30 minutes, excellent film gloss was obtained. The measurement of gloss was 72% when 20 ° gloss was measured with a digital variable angle gloss meter.

Organic dye compound (a) (phthalocyanine type)

[Chemical 7]

Example 2 A paint was prepared in the same manner as in Example 1 except that the neutralization ratio of the pigment-dispersed resin was changed to 120%, and the mixture was spread on a PET film and baked, resulting in excellent fluidity and excellent film formation. Gloss is obtained, 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 dilute acrylic resin, and the mixture was spread on a PET film and baked to find excellent fluidity and excellent film gloss. The TI value was 1.2 and the 20 ° gloss was 70%.

Examples 4 to 14 Pigment dispersion resins containing the following organic dye compounds (b) to (i) as neutralizing agents were used in accordance with Example 1 for various pigments. As with No. 1, excellent film gloss was obtained. The results are shown in Tables 1 and 2.

Organic dye compound (b) (phthalocyanine type)

Embedded image

Organic dye compound (c) (phthalocyanine type)

[Chemical 9]

Organic dye compound (d) (quinacridone type)

[Chemical 10]

Organic dye compound (e) (dioxazine type)

[Chemical 11]

Organic dye compound (f) (anthraquinone type)

[Chemical 12]

Organic dye compound (g) (perylene type)

[Chemical 13]

Organic dye compound (h) (diaminoanthraquinone type)

Embedded image

Organic dye compound (i) (benzimidazolone type)

[Chemical 15]

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

[0045]

[Table 1]

[0046]

[Table 2]

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Claims (4)

[Claims] 1. A water-based pigment dispersion, characterized in that the water-based resin is neutralized with a neutralizing agent whose main component is an organic dye compound having a basic group at the terminal represented by the general formula (1). resin. 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 ; alkylene group or arylene group which may have a substituent) Y ₁ ; -NH- or -O-Z; hydroxyl group, alkoxy group or general formula (2) general formula (2) ] (Y ₃ ; -NH-, or -O-), or n = 1
In the case of -NH-X-Q may be R < ₁ >, R < ₂ >; each independently a substituted or unsubstituted alkyl group or R < ₁ > and R < ₂ > may form at least a heterocycle. m; an integer of 1 to 6 n; an integer of 1 to 4 2. The resin for dispersing an aqueous pigment according to claim 1, wherein the aqueous resin is an acrylic copolymer system. 3. An aqueous pigment dispersion, comprising a pigment dispersed by the resin for dispersing an aqueous pigment according to claim 1 or 2. 4. The aqueous pigment dispersion according to claim 3, which comprises 100 parts by weight of the pigment and 5 to 700 parts by weight of the aqueous resin.