| abstract |
The present invention relates to an aqueous solution of leucoindigo comprising an aromatic amine, in particular aniline or aniline and N-methylaniline, the concentration of said aromatic amine being less than 200 ppm, the leucoindigo salt in the solution in the form of a mixed salt of sodium and potassium, the molar ratio of sodium to potassium being in the range of greater than 3: 1 to 10: 1, and preferably the concentration salt being in the range of greater than 25 to 45% by weight, based on the total weight of the solution. |