PROCESS FOR THE SINGLE-BATH DYEING OF CELLULOSE FIBRES OR MIXTURES THEREOF WITH SYNTHETIC FIBRES WITH WATER-INSOLUBLE AZO DYESTUFFS PRODUCED ON THE FIBRE BY THE EXHAUSTION METHOD

摘要

1422995 Dyeing cellulosic materials with azoic dyes HOECHST AG 16 March 1973 [18 March 1972] 12782/73 Heading D1B Cellulosic fibres, or mixtures thereof with synthetic fibres e.g. polyester are dyed by treating the material at room temperature to 30‹C with an aqueous dyebath formed by addition to water of an alkaline agent, sodium nitrite, an anionic dispersing agent, a solution or dispersion of a non-diazotised primary amine in a water-miscible organic solvent and a solution or dispersion of an azo coupling component in a water miscible organic solvent, allowing the material to absorb the coupling component and subsequently adding an acid or acid salt at room temperature to cause dyestuff formation. The cellulosic fibres include flax, hemp, linen, cotton, regenerated fibres, viscose staple fibres, spun or modal fibres and a goods: liquor ratio of 1:10 to 1:30 is preferred. Both components may be dissolved or dispersed together or separately in an aliphatic C 1 -C 4 alcohol e.g. methanol, ethanol, propanol or butanol, preferably mixed with sodium hydroxide solution and water and the amine may also be dissolved in diacetone alcohol, dimethylsulphoxide, dimethylformamide, dimethylacetamide, tetrahydrofurfuryl alcohol. glycerin or methoxy butanol. A second anionic dispersing agent may be added after addition of the acid. The dyeing is finally soaped off.