AQUEOUS DYESTUFF PREPARATION, PROCESS FOR ITS PRODUCTION AND ITS USE IN DYEING AND PRINTING

摘要

The aqueous dyestuff formulation of an tetrakisazo direct dyestuff which is stable to alkali and contains at least one aromatic hydroxyl group and/or enol group and at least one group conferring solubility in water, or a mixture of such azo direct dyestuffs, is characterized in that it has a pH value equal to or greater than 12 and is prepared by mixing an azo direct dyestuff which is stable to alkali, water and a tertiary alkali metal phosphate and/or alkali metal metasilicate and/or alkali metal hydroxide, and by choosing the proportions such that the dyestuff formulation contains 5 to 50% by weight of dyestuff and has a pH value equal to or greater than 12. The dyestuff formulation is used, after dilution with water, for dyeing and printing natural or synthetic materials containing hydroxyl groups.