JPS61123668A - Azo lake pigment - Google Patents

Abstract

PURPOSE:The titled red pigment that is obtained by coupling both a diazo compound of a specific amine and diazotized chloromethylaniline sulfonic acid to hydroxynaphthalenesulfonic acid, forming the product into lake, thus showing high stability. CONSTITUTION:(A) The diazo compound of an amine of the formula (X is acylamino, alkoxy, nitro; Y is carboxyl, sulfonic group; Z is methyl, H) and (B) diazotized 3-chloro-4-methylaniline-6-sulfonic acid are coupled to (C) 2- hydroxynaphthalene-3-carboxylic acid and the product is made into lake. The content of component A is preferably 0.1-50mol%, while B, 99.9-50mol%.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to azo lake pigments for printing inks. More specifically, the present invention relates to a pigment that improves the tone of Watchan Red for printing inks, particularly for gravure or flexography.

BACKGROUND OF THE INVENTION In printing inks, especially gravure or flexo inks, bright and resistant red pigments are desired.

Conventionally, brilliant carmine 6B (C, I, Pigmen) has been used as a red pigment for such printing inks.
tRed 57: 1) is known, which diazotizes p-)shiidine-m-sulfonic acid and diazotizes it with 3-oxy-2
- It is obtained by making the dye produced by coupling with naphthoic acid insoluble (laked) using a lake forming agent. However, this pigment has disadvantages such as poor fluidity, thickening over time, and poor stability, and has been used only in limited applications.

Wochan Red is also used, but this has the disadvantage that the color tone is a little too yellowish, and in reality it is used as a complementary color with expensive naphthol pigments.

Problems to be Solved by the Invention Under these circumstances, there is a desire in this field to develop a new red pigment that can be expected to produce an excellent color tone in place of the conventional red pigment.

Therefore, an object of the present invention is to provide a red pigment for gravure or flexography that does not exhibit the above-mentioned drawbacks.

Means for Solving the Problems In view of the above-mentioned current state of red pigments for gravure or 7-lexo, the inventors have conducted various studies and research to improve the color tone of Wochan Red. The present inventors have found that the combined use of a diazotide and a diazotide of 3-chloro-4-methylaniline-6-sulfonic acid is extremely advantageous for achieving the above object, and have completed the present invention.

That is, the improved blushing material of the present invention has the following general formula (): % formula %) However, in the general formula (I), X is an acylamino group,
A diazotized product of an amine, which represents an alkoxy group or a nitro group, Y represents a carboxyl group or a sulfonic acid group, and Z represents a methyl group or a hydrogen atom, and 3-chloro-4-methylaniline-6-sulfone. A special effect of the pigment of the present invention, characterized in that the diazotide of the amine of general formula (I) is coupled to 2-hydroxynaphthalene-3-carboxylic acid to form a lake. The relative ratio of chloro-4-methylaniline-6-sulfonic acid to the diazotide is 0.1 in the former.
It is preferably within the range of ~50 mol%, and the latter is preferably within the range of 99.9~50 mol%. That is, in order to effectively improve the yellowish tone of Watchan Red, the mixture of diazotides in the above ratio should be mixed with 2-hydroxynaphthalene-3-
Coupling with a carboxylic acid is desirable.

In the amines of general formula (1) useful in the pigments of this invention, the acyl and alkyl moieties of the alkoxy substituent X are in the range of 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms.

Amines of formula (I) which are particularly useful in the pigments of the invention include, for example, 2-methoxyaniline-5-sulfonic acid, 4-methoxyaniline-2-sulfonic acid, 4-methoxyaniline-3-sulfonic acid, 4-methoxyaniline-3-sulfonic acid, -Ethoxyaniline-2-sulfonic acid, 4-acetylaminoaniline-2-
Sulfonic acid, 4-a7tylaminoaniline-2-carboxylic acid, 2-nitroaniline-4-sulfonic acid, 4-nitroaniline-2-sulfonic acid, 2-methoxy-5-methylaniline-4-sulfonic acid, 2-ethoxy-5-methylaniline-4-sulfonic acid, 4-butoxyaniline-
2-sulfonic acid, etc., and can be expected to have an excellent effect of improving the color tone of Wochan Red.

3-chloro-4-methylaniline-6-sulfonic acid (2
Diazotization of B acid) and the amine of general formula (I) can be carried out according to any known diazotization method, for example, by allowing both to exist simultaneously and allowing nitrous acid to act;
Alternatively, diazotization can be carried out by separately subjecting it to the action of nitrous acid.

Coupling of the diazotide thus produced with 2-hydroxynaphthalene-3-carboxylic acid and formation of a lake from the coupling product can be carried out using any of the known techniques.

That is, for example, a diazo component may be coupled to 2-hydroxynaphthalene-3-carboxylic acid and then formed into a lake, or a lake forming agent may be dissolved in advance in the diazo component and this may be combined with 2-hydroxynaphthalene-3-carboxylic acid. It is also possible to react with 3-carboxylic acid and perform coupling and lake formation at the same time.

In these coupling and lake forming reactions, either a batch method or a continuous method can be used.

In addition, as a rake agent, Ca, Ba5Sr, Mn
It is possible to use various salts of alkaline earth metals such as.

In this way, by changing Watchan Red, which has conventionally been yellowish in color, to a bluish carmine color, a pigment with fewer defects can be obtained.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the scope of the present invention is not limited in any way by these Examples.

Example 1 15.5 g of sodium 2B acid was dispersed in 400 cc of water with stirring, and then heated and dissolved. Add this to concentrated hydrochloric acid 16
, 3 g to precipitate crystals, cooled with ice, and diazotized by adding 4.6 g of sodium nitrite dissolved in water.

1.28 g of p-anisidine-〇-sulfonic acid was diazotized with 0.5 g of sodium nitrite in the same manner as above. Mix both to make a diazo solution.

13.4 g of β-oxynaphthoic acid is added to 500 cc of water, and 7.5 g of caustic soda is added and dissolved. 2 to this
Add the diazo solution at 0 to 25° C. and perform turn-pulling.

After neutralization, the temperature was raised to 50°C, and strontium chloride 20,
Add 8 g to form a rake. After further raising the temperature and boiling, filter, wash with water, and dry.

The pigment thus obtained was kneaded with a water-based varnish to form an ink, which was spread on liner paper. The color tone was a bluish carmine color, the concentration was high, and the stability over time was excellent.

The mixture was also kneaded with urethane varnish to form ink, which was then spread on a transparent film. The color tone was carmine, with excellent transparency, high density, and good gloss.

Examples 2-9 Following the procedure of Example 1, but using the p-
A similar azo lake pigment was prepared by substituting 1.28 g of anisidine-0-sulfonic acid with the amines listed in the table below, each in the amounts listed below.

In the same manner as in Example 1, these pigments were used to stain ink, and color measurements were performed under the same conditions. The results are shown in the table below.

Example 10 12.7 g of sodium 2B acid was dispersed in 120 cc of water with stirring, and then heated and dissolved. In the resulting solution, 3.5 g of p-anisidine-〇-sulfonic acid was added to 75 c of water.
In addition to c, a solution prepared by adding and dissolving 0.7 g of caustic soda was added, and then 17.1 g of concentrated hydrochloric acid was added to precipitate crystals. This is cooled with ice, and 5.2 g of sodium nitrite dissolved in water is added to perform diazotization to obtain a diazo liquid.

13.4 g of β-oxynaphthoic acid is added to 500 cc of water, and 7.5 g of caustic soda is added and dissolved.

The diazo solution is added at 20-25°C to perform coupling. After neutralization, the temperature was raised to 60°C and strontium chloride 20,
Add 8 g to form a rake. After boiling at elevated temperature, filter, wash with water, and dry. The pigment thus disgraced was kneaded with a water-based fest, turned into ink, and then spread on liner paper. The color tone was an extremely bluish carmine color, the concentration was high, and the stability over time was excellent.

In addition, the mixture was kneaded using a urethane-based cloth, and after being made into ink, the color was spread on a transparent film. The color tone was an extremely bluish carmine color with excellent transparency and density.

Effects of the Invention As explained in detail above, the azo lake pigment of the present invention is obtained by coupling a diazotide of an amine of the general formula (°I) and a diazotide of a 2B acid to a specific naphthoic acid and then forming a lake. However, this makes it possible to greatly improve the color tone of the red pigment, and also to obtain an azo lake pigment with high concentration and high stability over time. That is, Wochan Red has a marked yellowish tinge as it is, and there is a need to improve this. Conventionally, the above-mentioned drawbacks of Wochan Red have been improved by, for example, complementary coloring with expensive naphthol pigments. However, according to the present invention, it is possible to improve the conventional yellowish color by changing it to a bluish carmine color without using complementary colors using expensive pigments. Can be provided. Therefore, the present invention can be said to be extremely advantageous from an industrial standpoint.

Claims (6)

[Claims] (1) General formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) However, in the general formula (I), X is an acylamino group, an alkoxy group, or a nitro group, and Y is a carboxyl group or a sulfone group. is an acid group, and Z represents a methyl group or a hydrogen atom; and a diazotide of 3-chloro-4-methylaniline-6-sulfonic acid are combined into 2-
A pigment characterized by being coupled to hydroxynaphthalene-3-carboxylic acid to form a lake. (2) The diazotized product of the amine is within the range of 0.1 to 50 mol%, and the 3-chloro-4-methylaniline-
The pigment according to claim 1, characterized in that the diazotized product of 6-sulfonic acid is in the range of 99.9 to 50 mol%. (3) In the amine of the general formula (I), the substituent X
3. The pigment according to claim 1, wherein the acyl moiety of and the alkyl of alkoxy have 1 to 4 carbon atoms. (4) The pigment according to claim 3, wherein the acyl moiety of the substituent X and the alkyl moiety of the alkoxy have 1 to 2 carbon atoms. (5) The amine of the general formula (I) is 2-methoxyaniline-5-sulfonic acid, 4-methoxyaniline-2-sulfonic acid, 4-methoxyaniline-3-sulfonic acid, 4-methoxyaniline-3-sulfonic acid,
-Ethoxyaniline-2-sulfonic acid, 4-ethoxyaniline-3-sulfonic acid, 4-acetylaminoaniline-2-sulfonic acid, 4-acetylaminoaniline-2-
Carboxylic acid, 2-nitroaniline-4-sulfonic acid, 4
-Nitroaniline-2-sulfonic acid, 2-methoxy-5
-Methylaniline-4-sulfonic acid, 2-ethoxy-5
The pigment according to claim 4, which is at least one selected from the group consisting of -methylaniline-4-sulfonic acid and 4-butoxyaniline-2-sulfonic acid. (6) The pigment according to claim 5, wherein the laked metal is an alkaline earth metal.