CS252596B1 - Gray to black 1: 2 chromocomplexed azo dyes - Google Patents

Abstract

The invention relates to grey to black 1:2 chromium complex azo dyes. In the dyeing and printing of wool and PAD, ranges of acidic, sulfo-substituted 1:2 metal complex o,o* 1 * * -dihydroxy azo dyes have been gaining popularity in recent years, which are characterized by high fastness, high cold solubility, excellent uniformity and extractability and universal use. They are coordination complexes of 1 metal atom with coordination number 6 (most often chromium or cobalt) with two identical or different o,o'-dihydroxy-, o-hydroxy-o1-carboxy- or o-hydroxy-o'-amino azo dyes. The water solubility of these 1:2 metal complex azo dyes is increased by suitable substitution. 1:2 metal complex dyes are known, solubilized by nonionic, hydrophilicity-increasing substituents, such as sulfamoyl or methanesulfonyl groups. However, the production of these dyes is relatively expensive. The same quality of dyeing has also been achieved by using dyes solubilized by sulfo groups. However, the introduction of sulfo groups into the molecule of a 1:2 metal complex dye is not without problems. While nonionic substituted 1:2 metal complexes are essentially salts of monobasic acids, substitution by sulfo groups increases the negative charge of the dye anion and thus can understandably adversely affect its dyeing capabilities, especially dyeing equality and extractability. Moreover, the dyeing behavior is influenced not only by the electric charge, but also by the substitution topography and spatial arrangement of the dye complex molecule.

Description

Grey to black 1:2 macrocomplex azo dyes have now been found, consisting according to the invention of a mixture of monosulfonated (I) and disulfonated (II) 1:2 chromium complexes

II where

M = Na, K, NH ₄

= NO ₂ in the range 0.2 to 0.5 mol both x ₂ = no ₂ 0.5 until 0.8 mol ^X 3 " SO ₃ H and X ₄ = NO ₂ ^Y 1 = ^H 0.7 until 0.9 mol or both Y ₂ = NHCOCH ₃ 0.1 until 0.3 mol ^X 3 = NO ₂ and X ₄ = SO ₃ H

in the ratio I:II = 0.05 to 0.95:0.9.5 to 0*05 and can be prepared by coordination chromization of a mixture of unsulfonated and sulfonated o,o ¹ -dihydroxyazo dye and a 1:1 chromium complex of an o,o'-dihydroxyazo dye containing one sulfo group in the molecule, or directly by mixing I and II wet or dry, respectively.

By increasing the content of the disulfonated 1:2 chromium complex (II) according to the invention, the dyeing properties of the monosulfonated 1:2 chromium complex can be favorably influenced: dyes with a higher proportion of the disulfonated component (II) show a significant improvement in cold solubility while maintaining other dyeing properties such as extractability and evenness; they dye wool and PAD from a weakly acidic to neutral bath, they can be well combined with other dyes of the same or even a different metal complex range, or with common acidic dyes.

Example

49.2 g (0.1 mol) of the chromium 1:1 complex of the monoazo dye 6-nitro-2-aminophenol-4-sulfonic acid-.>· 2-naphthol in the form of a paste is introduced into a 70 °C warm alkaline suspension of 19.2 g (0.06 mol) of the monoazo dye from 2 parts of 4,S-nitro-2-aminophenol and 1 part of 4-nitro-2-aminophenol—fr 4 parts of 2-naphthol and 1 part of 1,7-acetaminonaphthol in the form of a paste or coupling suspension and 15.6 g (0.04 mol) of the monoazo dye 6-nitro-2-aminophenol-4-sulfonic acid—>» 2 naphthol in the form of a paste or coupling suspension. After several hours of heating at 85 to 95 °C, a solution of the mixed 1:2 chromium complex is formed in black. Evaporation yields 130 g of a strong dye that dyes wool and PAD a black shade.

Example 2 g of ostaline black FBGL and 30 g of chromium 1:2 complex of monoazo dye 6-nitro-2-aminophenol-4-sulfonic acid — 2-naphthol are homogenized. 100 g of dye is obtained, which dyes wool and PAD in a gray to black shade.

Example 3 g of ostaline Black FBGL and 20 g of chromium complex 1:2 complex of monoazo dye 4-nitro-2-aminophenol-6-sulfonic acid—^ 2-naphthol are homogenized. 100 g of dye is obtained, which dyes wool and PAD in a gray to black shade. j

SUBJECT OF THE INVENTION

Claims (1)

SUBJECT OF THE INVENTION grey to black 1:2 chromium complex azo dyes characterised in that they consist of a mixture of monosulfonated (I) and disulfonated (II) 1:2 chromium complex where M = Na, K, NH ₄ in the range both ^X 1 ^{= N0} 2 0.2 to 0.5 moles X ₃ = SOjH and X ₄ = NO ₂ or X ₂ = NO ₂ 0.5 to 0.8 moles X ₃ = NO ₂ and X ₄ = SO ₃ H ^Y 1 = ^H 0.7 to 0.9 moles Y ₂ = NHCOCH ₃ 0.1 to 0.3 moles in the ratio I:II = 0.05 to 0.95:0.95 to 0.05.