CS268606B1 - Method of mixed pigment preparation - Google Patents

Abstract

The mixed pigment is prepared by coupling mixtures of diazotized aminosulfonic acids benzene and naphthalenic acids series with 3-hydroxy-2-naphthoic acid and converting the resulting azo dye to insoluble pigment lacquer. The diazotized mixture is subjected to coupling aminosulfonic acid containing 75 to 99.5 mol% of diazotized amine of formula I wherein R 1 and R 1 are H, Cl or CH 2 and 0.5 to 25 4 mol diazotized 2-naphthylamino-n-sulfonic acid, wherein n is 1,5,6,7 or 8.

Description

The invention relates to mixed azo pigments based on 3-hydroxy-2-naphthoic acid and to a process for their preparation. ΘΘ _B. . . SO. HOCOO

Azolacs of the general formula J

dke R | and R ₂ are H, CH ₃ or Cl In various combinations and M is calcium, barium, magnesium, strontium or manganese, they are an important part of the palette of red pigments. They are used in the paint and varnish industry, for dyeing plastics and rubber and in printing. The strictest requirements are placed on azolacs used in color printing (offset, gravure printing), especially in terms of yield, color shade and tone purity. Conditions for the coupling of the diazotized amine with 3-hydroxy-2-naphthoic acid and for the coating of the resulting azo dye with soluble salts of calcium, barium, strontium or manganese, as well as the application of auxiliaries during or after synthesis (Czech author 's certificate No 221 701;

226 132) the required pigment yield can be achieved, but very often in industrial production it is not possible to obtain a product suitable in terms of color shade. The change in hue cannot be achieved by adding another pigment to the base pigment, because simply mixing two or more powder pigments worsens the brilliance of the hue and the product is also unsatisfactory in terms of application. .

Research has now shown that it is possible to produce mixed azo pigments (azolacs) of the desired shade by coupling a mixture of diazotized aminosulfonic acids of benzene and naphthalene series with 3-hydroxy-2-naphthoic acid and converting the resulting mixed azo dye into an insoluble pigment varnish with soluble calcium, barium and magnesium salts. , strontium contains or manganese, said mixture of diazotized aminosulfonic acids 75 to 99.5 mol% of diazotized amine of general formula

SO ₃ H (II)

R ₂ are H, Cl or CH ₃ , n-sulfonic, where n is 1,

5, 6, 7 r ₂ and 0.5 to 25% or 8.

mol of diazotized acid 2-naphthylamine In the preparation of the mixed pigment of the present invention, a mixture containing a diazotized amine of formula (II) is first prepared, which amine may be, for example, 4-amino-toluene-3-sulfoic acid, 3-aminotoluene-4-sulfoic acid, 2-chloro-4-aminotoluene-5-sulfoic acid, 2-chloro-5-aminotoluene-4-sulfoic acid, and diazotized 2-naphthylamine-n-sulfonic acid, i.e. for example 2-naphthylamine-1-sulfonic acid, or 2- naphthylamine-5-sulfonic, 2-naphthylamine-6-sulfonic, 2-naphthylamine-7-sulfonic, or 2-naphthylamine-8-sulfonic. The mixture contains 75 to 99.5 mol% of the diazotized amine of formula (I) and 0.5 to 25 mol% of the diazotized 2-naphthylamine-n-sulfonic acid. The amount of 2-naphthylamine-n-sulfonic acid must be chosen on a case-by-case basis according to the desired final shade of the product.

It is not decisive for the effect according to the invention whether the mixture of the two active components is diazotized or whether the diazo compound solutions are prepared separately and only then mixed. It is also not decisive whether the diazotization is performed directly or indirectly - 2 -. CS 268605 Bl way.

The mixture of diazotized aminosulfonic acids is coupled in an alkaline medium with 3-hydroxy-2-nitrophonic acid, preferably in the presence of compounds formed by the formation of dye insoluble salts or varnishes, for example calcium or barium, barium, magnesium, strontium chloride or nitrate. or aanganaty. The compounds formed with their dye insoluble salts can also be applied only after the coupling reaction has ended. During the coupling, surfactants such as rosin soap, oxyethylated alcohols or alkylphenols, condensation products of naphthalenesulfonic acid with formaldehyde, etc. may be present in the reaction mixture.

Coupling of a mixture of diazotized aminosulfonic acids of the benzene and naphthalene series and subsequent varnishing of the dye produces a pigment whose crystal lattice content is. is a molecule of both compounds formed in the coupling reaction. This guarantees a brilliant shade of the final products, which cannot be achieved by simply mixing pigment powders produced separately. At the same time, the ratio of the starting active components can vary the shade of the resulting mixed pigments in a very wide range according to the consumer's requirements.

The mixed pigments produced by the process according to the invention can be used in a number of applications, preferably in polygraphy, where the exact shade of the colorant is absolutely necessary.

The examples illustrate the process for the production of mixed pigments according to the invention.

Example 1

Diazotization

P. solution A: To 400 ml of a solution of sodium salt of 4-aminotoluene-3-sulfoic acid at a concentration of c = 0.48 mol 1 * (ie 0.192 mol) was added 100 ml of hydrochloric acid c (HCl) = 5 mol 1 and the mixture was cooled to -3 ° C. To this mixture, 39 ml of a sodium nitrite solution c (NaNO ₂ ) = 5.0 mol l ^-1 was admitted with vigorous stirring.

Solution B: To 32 ml of a solution of the sodium salt of 2-naphthylamine-1-sulfonic acid oc = 0.25 mol 1 (ie 0.008 mol) was added 5.0 ml of hydrochloric acid c (HCl) = 5 mol 1 and 50 ml calcium chloride solution c (CaCl ₂ ) = 3.0 mol l ^-1 (i.e. 0.15 mol). The mixture was cooled to -5 ° C, and 8.0 ml of a sodium nitrite solution (NaNO 3) = 1.0 mol 1 was added to the mixture with stirring. Solution B was added to solution A, and the mixture was stirred.

Coupling:

600 ml of a solution of the sodium salt of 3-hydroxy-2-naphthoic acid oc = 0.125 mol 1 (ie 0.2 mol) at pH = 10. was cooled to -5 ° C. A mixture of diazonium salts was added to this solution with stirring and cooling, while the pH was automatically maintained at 10 x 0.3 by adding sodium hydroxide solution (NaOH) = 10.0 mol 1 '. To the reaction mixture were then added 50 ml of a solution of calcium chloride c _(CaCl?)

-1 - ^z = 3.0 mol 1 and the suspension was stirred for 30 minutes. The reaction mixture was acidified with hydrochloric acid c (HCl) = 5.0 mol 1 to pH = 6, stirred for 30 minutes and filtered on a Bicht nut. Chloride ions were washed from the filter cake, and the product was dried at 90 ° C and ground. The mixed pigment produced contains 96.0 mol% of 4- (2-sulfo-4-methylbenzenazo) -3-hydroxy-2-naphthoic acid calcium salt and 4.0 mol% of 4- (1-sulfo-2-naphthalenazo) calcium salt. -3-hydroxy-2-naphthoic acid. Compared to the calcium salt of 4- (2-sulfo-4-methylbenzenazo) -3-hydroxy-2-naphthoic acid, this mixed pigment has a bluer shade, by 3 coloristic degrees.

CS 268606 Bl

- 3 Example 2

Following a procedure as in Example 1, a mixed pigment was prepared containing 92.0 mol% of the calcium salt of 4- (2-sulfo-4-methylbenzenazo) -3-hydroxy-2-naphthoic acid and 8.0 mol% of the calcium salt of 4- (1- sulfo-2-naphthalenazole-3-hydroxy-2-naphthoic acid. Compared to the calcium salt of 4- (2-sulfo-4-methylbenzenazo) -3-hydroxy-2-naphthoic acid, the mixed pigment has a bluer shade, by 7 coloristic degrees.

Example 3

A mixture of 95.0 mol% of 2-chloro-4-aminotoluene-3-sulfoic acid and 5.0 mol% of 2-naphthylamine-8-sulfonic acid was diazotized. The diaza solution was coupled as in Example 1 with 3-hydroxy-2-naphthoic acid sodium salt. The dye was converted to an insoluble varnish with barium chloride.

Example 4

Following a procedure as in Example 1, a mixed pigment containing 84.0 mol% of the strontium salt of 4- (2-sulfo-4-methylbenzenazo) -3-hydroxy-2-naphthoic acid and 16.0 mol% of the strontium salt of 4- (5-sulfo) was prepared. -2-naphthalenazole-3-hydroxy-2-naphthoic acid.

Claims (1)

OBJECT OF THE INVENTION Process for the preparation of a mixed pigment by coupling a mixture of diazotized aminosulfonic acids of benzene and naphthalene series with 3-hydroxy-2-naphthoic acid and converting the resulting mixed azo dye with soluble salts of calcium, barium, magnesium, strontium or manganese to an insoluble pigmented lacquer, characterized in that the coupling subjectes a mixture of diazotized aminosulfonic acids containing 75 to 99.5 mol% of a diazotized amine of general formula (I) NHj wherein R 1 and R ₂ are H, Cl or CH 2, and min-n-sulfonic, wherein n is 1, 5, 6, 0.5 to 25 mol% of diazotized 2-naphthyl acid7 or 8