JPH0696680B2 - Azo pigment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an azo pigment having excellent suitability for use, particularly fluidity, gloss, sharpness and stability over time.

(Prior Art) A pigment in which an azo dye having two or more acid groups in one molecule is laked is glossy and vivid due to poor dispersion when used in an aqueous coating agent such as an aqueous printing ink or an aqueous paint. It was difficult to put it into practice because the viscosity was high due to physicochemical interaction with the binder, and the ink thickened or gelled during storage.

Heretofore, as a method for solving the problem, a method of surface-treating various resins or surfactants on a pigment or a method of co-lake with a different alkaline earth metal has been carried out. Didn't arrive.

(Problems to be Solved by the Invention) Calcium or barium lake pigments of one or more azo dyes containing two or more acid groups in one molecule contain one acid group in one molecule. Unlike water-based coatings, the rheological properties are particularly poor. The present invention relates to an azo pigment effective for suitability for use of an aqueous coating material.

(Structure of the Invention) (Means for Solving the Problem) The present invention forms a sparingly soluble salt with an alkaline earth metal ion in an azo dye (I) having two or more carboxylic acid groups or sulfonic acid groups. 1 water-soluble anion activator (II)
It is an azo pigment characterized in that a mixture obtained by mixing up to 20% by weight thereof is laked with a calcium metal salt or a barium metal salt and a strontium metal salt.

Although an azo lake pigment using calcium and strontium is known, it is difficult to say that the obtained pigment has sufficient sharpness and gloss.

The present invention produces a calcium or barium lake pigment having a carboxylic acid group or a sulfonic acid group in the presence of a water-soluble anionic activator (II), and then adds strontium ion to part of the calcium or barium ion and strontium ion. Mixture of calcium or barium and strontium lake pigments, and activator calcium or barium and sparingly soluble salts of strontium, by performing ion exchange of strontium or adding strontium ions and then adding calcium or barium ions. Is generated. In the present invention, an azo dye (I) containing two or more acid groups in one molecule
Examples of the water-soluble activator (II) include CI15825, CI15880, CI16105 and the like. Examples of the water-soluble active agent (II) include sodium soap, sodium linoleate, sodium stearate, ammonium lauryl sulfate, sodium polyoxyethylene alkylphenol ether sulfate, and naphthalene sulfonic acid. Formalin condensate sodium salt, sodium dodecylbenzene sulfonate, sodium alkylnaphthalene sulfonate, polycarboxylic acid type polymer activator and the like can be mentioned. Examples of the calcium metal salt or barium metal salt include calcium chloride and barium chloride, and examples of the strontium metal salt include strontium chloride and strontium nitrate.

The water-soluble activator (II) is preferably used in an amount of 1 to 20% by weight based on the azo dye (I). Calcium metal salt or barium metal salt is 0.7 per mol of pigment produced.
.About.2.5 mol, and for strontium metal salt, 0.3 to 2.0 mol per mol of pigment produced.

(Function) In the present invention, the water-soluble anionic activator (II) is considered to act as a dispersant to make the pigment particles fine and evenly distributed by uniformly performing lake formation. Further, the sparingly soluble salt of the water-soluble anionic activator (II) acts as an agent for improving dispersibility at the time of forming an ink by the effect of preventing crystal growth when the pigment particles are precipitated, and also has stability over time. It is believed that it contributes to prevent the deterioration of rheological properties by the interaction between the varnish and the lake pigment of calcium or barium during storage of the ink.

If the amount of the strontium metal salt added exceeds 2 moles per 1 mole of the produced pigment, the above-mentioned crystal growth preventing effect and fluidity improving effect are improved, but the hue becomes yellowish, so that it is practically 0.3- 2 mol is desirable.

Additives usually used for the azo pigment of the present invention can be added as required.

The present invention will be described below with reference to examples. In the examples, "middle part" means "part by weight" and "%" means "% by weight".

Example 1 30 parts of 4-aminotoluene-3-sulfonic acid are completely dissolved by stirring with 400 parts of water and 7 parts of sodium hydroxide at room temperature for 10 minutes. After adding 40 parts of 35% hydrochloric acid to acidify, add 200 parts of ice and cool to 30 ° C or below. 12 parts of sodium nitrite dissolved in 40 parts of water was added, and β-oxynaphthoic acid was added.
33 parts of water, 600 parts of water, 15 parts of sodium hydroxide and 9 parts of sodium carbonate were stirred at room temperature for 60 minutes to completely dissolve them to obtain a coupler component. The above-mentioned diazo component is required for 15 minutes in this coupler component, and after dropwise addition, stirring is further continued for 1 hour to complete the coupling reaction. The pH of the coupling liquid was 8.5. Then add 8 parts of sodium stearate and stir for 30 minutes, then add 20% calcium chloride aqueous solution.
Add 250 parts, then 30% strontium chloride aqueous solution 100
Parts were added, heated to 80 ° C. and stirred for 30 minutes. After filtration and washing with water, the product was dried in a hot air circulation type oven at 80 ° C. overnight to obtain 80 parts of a red pigment.

A diazo component and a coupler component as shown in Table 1 were reacted according to Example 1 and then an activator (resin in the comparative example) metal salt was added to obtain a pigment.

The tests on the pigments obtained in Examples 1, 2 and 3 and Comparative Examples 1 and 2 were carried out as follows. Pigment 14g
Was dispersed in 86 g of common aqueous gravure varnish using 150 g of alumina beads. The viscosity of the ink obtained,
The results of hue sharpness, tinting strength and gloss are summarized in Table 2.

Comparative Example 3 An azo pigment was obtained in the same manner as in Example 1 except that sodium rosin was used in place of sodium stearate. The performance of the aqueous gravure ink obtained by using the azo pigment in the same manner as described above is shown below.

[Effects of the Invention] The following effects were confirmed by the present invention.

(1) The water-based coating agent markedly improves the suitability for use such as fluidity and non-polymerizability.

(2) The aqueous coating agent was excellent in hue clarity, tinting strength and gloss.

Claims (4)

[Claims] 1. An azo dye (I) having two or more carboxylic acid groups or sulfonic acid groups, and 1 to 20 parts by weight of a water-soluble anionic activator (II) which forms a sparingly soluble salt with an alkaline earth metal ion. %, An azo pigment obtained by lake-forming the mixed mixture with a calcium metal salt or a barium metal salt and a strontium metal salt. 2. The azo pigment according to claim 1, wherein the azo dye (I) is a β-oxynaphthoic acid azo dye or a β-naphthol azo dye. 3. The azo pigment according to claim 1, wherein the amount of the calcium metal salt or the barium metal salt is 0.7 to 2.5 mol per mol of the produced pigment. 4. The azo pigment according to any one of claims 1 to 3, wherein the amount of the strontium metal salt is 0.3 to 2.0 mol per mol of the produced pigment.