JPH08199093A - Water-based pigment composition - Google Patents

Abstract

PURPOSE: To obtain a water-based pigment compsn. reduced in viscosity increase even after the lapse of time by using a pigment, an acrylic ester emulsion, a high-boiling water-soluble solvent, a condensed naphthalenesulfonic acid salt, a substance represented by a specific formula, and water. CONSTITUTION: This compsn. comprises (A) a pigment, (B) an acrylic ester emulsion, (C) a high-boiling water-soluble solvent, (D) a condensed naphthalenesulfonic acid salt, (E) a substance of the formula (wherein R is 1-10C alkyl; n is a positive integer; and M is Na, K or NH4 ), and (F) water. A conventional water-based pigment compsn. for use as a poster color, a water color, etc., comprises the components (A), (B), (C), and (F). In this case, when the amt. of the component (A) to be blended is increased in order to improve the color development of the compsn. or increase the density thereof, the applicability of the compsn. is deteriorated due to the viscosity increase thereof with the lapse of time. The compsn., when further blended with the components (D) and (E), is reduced in viscosity increase with the lapse of time, and can therefore be esp. suitably used as water-resistant poster color and water color.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based pigment composition suitable for use in water resistant poster colors, watercolors and the like. A water-based pigment composition used as a water-resistant poster color, watercolor paint, etc. is composed of a pigment, an acrylic ester emulsion, a high-boiling point water-soluble organic solvent, and water. It was The pigment is used as a coloring material. The acrylic ester emulsion is used as a fixing agent, and imparts water resistance to the application mark. The high boiling water-soluble organic solvent is used as an antifreezing agent and a drying time adjusting agent. By the way, when the aqueous pigment composition as described above is used as a poster color or a watercolor paint, the amount of the pigment to be mixed is adjusted in order to improve the color development or increase the concentration. If the amount is increased, the aqueous pigment composition thickens with time and the coating property of the paint is deteriorated. SUMMARY OF THE INVENTION The present invention is intended to obtain an aqueous pigment composition having a small increase in viscosity even after a lapse of time. The gist is an aqueous pigment composition comprising at least a boiling point water-soluble solvent, a condensed naphthalene sulfonate, a substance represented by Chemical formula 1, and water. Pigments are used as colorants. Various conventionally known inorganic pigments and organic pigments can be used. Specifically, carbon black, aniline black, titanium oxide, red iron oxide, cadmium red, lake red, carmine 3B, 6B, ocher, barium yellow, Hansa Yellow G, 10G, ultramarine, phthalocyanine blue, phthalocyanine green and the like can be mentioned. . These pigments may be used alone or as a mixture of two or more, and the amount thereof is preferably 10 to 50% by weight based on the total amount of the aqueous pigment composition. [0006] The acrylic ester type emulsion imparts water resistance to a coating mark and is also used as a color developing agent. Specifically, emulsions of esters such as methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, isopropyl acrylate, isopropyl methacrylate, butyl acrylate, and butyl methacrylate, or the above-mentioned acrylic ester or methacrylic acid. Examples thereof include emulsions of copolymers in which esters are combined. The amount used is preferably 5 to 30% by weight based on the total amount of the aqueous pigment composition. The high-boiling point water-soluble organic solvent is used as a freeze stabilizer, a drying regulator, etc., and examples thereof include glycerin, ethylene glycol, propylene glycol, dipropylene glycol and sorbitol. This high-boiling point water-soluble organic solvent can be used alone or as a mixture of two or more, and the amount used is 1 relative to the total amount of the aqueous pigment composition.
10% weight is preferred. The condensed naphthalene sulfonate is generally used as a pigment dispersant, and examples thereof include condensed naphthalene sulfonic acid sodium salt, condensed naphthalene sulfonic acid potassium salt, condensed naphthalene sulfonic acid ammonium salt and the like. The substance represented by Chemical formula 1 is generally called a polycarboxylic acid compound and is known to be used as a pigment dispersant. In the present invention, gelation of a composition containing a pigment and an acrylic ester emulsion is prevented by using the above-mentioned condensed naphthalene sulfonate and the polycarboxylic acid compound shown in Chemical formula 1 together. It becomes possible to improve the stability of the composition. The amount of each of the condensed naphthalene sulfonate and the polycarboxylic acid compound shown in Chemical formula 1 is preferably 0.1 to 10% by weight. In addition to the above components, if necessary, as an extender pigment such as calcium carbonate or barium sulfate, or a thickener,
0.05-2.0% by weight of water-soluble polymer such as carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose etc., or additives such as antiseptic / antifungal agent, antirust agent, defoaming / antifoaming agent, etc. You may use it suitably. The aqueous pigment composition of the present invention can be easily obtained by a conventionally known method. For example, the above components are mixed and dispersed by a disperser such as a three-roll mill, a horizontal ball mill, a horizontal bead mill. The surface of the pigment has the function of adsorbing various substances. When the amount of the pigment used is increased to improve the color development or to increase the concentration, the acrylic used as a fixing agent is used. The pigment adsorbs the emulsifier on the surface of the resin particles of the acid ester emulsion, and decomposes the acrylic ester emulsion. Therefore, the dispersion of the pigment that has adsorbed the emulsifier becomes poor and thickening occurs. It is considered that the condensed naphthalene sulfonate and the substance represented by Chemical Formula 1 are synergistically attached to the surface of the pigment, and the pigment can be in a state in which the emulsifier of the acrylic acid emulsion is not adsorbed, thus preventing thickening. EXAMPLES Examples and comparative examples will be shown below, but the present invention is not limited to the following examples. Example 1 Hansa Yellow G (CI Pigment Yellow 1) 10 parts by weight Polyacrylic acid ethyl emulsion 10 parts by weight Hydroxymethyl cellulose 0.5 parts by weight Glycerin 5 parts by weight Condensed naphthalene sulfonic acid sodium salt 0.5 parts by weight Part 1 Substance (M: sodium, R: ethyl group) 0.5 parts by weight Water 33 parts by weight Diethanolamine 0.5 parts by weight Calcium carbonate 40 parts by weight After the above ingredients are put in a lab mixer and stirred for 15 minutes, Two passes were performed on this roll mill to obtain a yellow aqueous pigment composition. Example 2 Carmine 6B (CI Pigment Red 57) 5 parts by weight Ethyl acrylate-butyl methacrylate copolymer emulsion 15 parts by weight Glycerin 5 parts by weight Condensed naphthalene sulfonic acid sodium salt 3 parts by weight Chemical formula 1 Substance (M: sodium, R: propyl group) 1 part by weight Water 40 parts by weight Concentrated ammonia water 0.5 parts by weight Carboxymethyl cellulose 0.5 parts by weight Calcium carbonate 30 parts by weight The above ingredients are placed in a lab mixer and stirred for 15 minutes. After that, the mixture was passed through a three-roll mill twice to obtain a red aqueous pigment composition. Example 3 Ultramarine (CI Pigment Blue 29) 40 parts by weight Butyl acrylate-methyl methacrylate copolymer emulsion 12 parts by weight Glycerin 5 parts by weight Condensed naphthalene sulfonic acid sodium salt 1 part by weight Substance (M: ammonium, R: hexyl group) 1 part by weight Water 37 parts by weight Concentrated ammonia water 0.5 parts by weight Hydroxypropyl cellulose 0.3 parts by weight Silicon oxide 3 parts by weight The above components were placed in a lab mixer and stirred for 15 minutes. Then, it was passed through a three-roll mill twice to obtain a blue water-based pigment composition. Example 4 Ultramarine (CI Pigment Blue 29) 40 parts by weight Butyl acrylate-ethyl methacrylate copolymer emulsion 12 parts by weight Glycerin 5 parts by weight Condensed naphthalene sulfonic acid ammonium salt 1 part by weight Substances shown (M: potassium, R: hexyl group) 1 part by weight Water 37 parts by weight Concentrated ammonia water 0.5 parts by weight Hydroxypropyl cellulose 0.3 parts by weight Silicon oxide 3 parts by weight The above components are put in a lab mixer and stirred for 15 minutes. After that, it was passed through a three-roll mill twice to obtain a blue aqueous pigment composition. Comparative Example 1 In Example 1, 0.5 part by weight of condensed sodium naphthalene sulfonate and 0.5 part by weight of the substance represented by Chemical Formula 1 were added.
A yellow aqueous pigment composition was obtained in the same manner as in Example 1 except that 1 part by weight of polyoxyethylene dodecyl ether known as a pigment dispersant was used. Comparative Example 2 In Example 2, 3 parts by weight of condensed sodium naphthalene sulfonate and 1 part by weight of the substance represented by Chemical Formula 1 were added to 4 parts by weight of polyoxyethylene dodecylphenyl ether known as a pigment dispersant. A red water-based pigment composition was obtained in the same manner as in Example 2 except that it was replaced. Comparative Example 3 Same as Example 3 except that 2 parts by weight of water was used instead of 1 part by weight of condensed sodium naphthalene sulfonate and 1 part by weight of the substance represented by Chemical formula 1. A blue aqueous pigment composition was obtained. The water-based pigment compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were subjected to a rheological property test. The results are shown in Table 1. Flow characteristic test JIS K 5101 Pigment test method 10.1 The average value of the values measured three times by the spread meter method was calculated. The unit is mm. The measurement was performed for the aqueous pigment compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3 immediately after preparation and after storage. Store 60 ml of each aqueous pigment composition
Was placed in a test tube with a lid, sealed and left at room temperature for 10 days. [Table 1] As described in detail above, the water-based pigment composition according to the present invention has little increase in viscosity over time, and is particularly useful as a water resistant poster color or watercolor paint.

Claims (1)

Claims: A pigment, an acrylic ester emulsion, a high-boiling water-soluble solvent, a condensed naphthalene sulfonate, and An aqueous pigment composition comprising at least the substance shown in 1) and water.