| abstract |
The invention relates to a method for producing liquid adjustments of basic azo dyes from a phenylenediamine I, which can be substituted by alkyl or alkoxy, by diazotization and coupling in an acidic solution. According to said method, the phenylenediamine is diazotized with sodium nitrite in the presence of at least two organic acids comprising at least one first acid (A) with a pkA value of = 4.0 and at least one second acid (B) with a pKA value = 4.1 and a nanofiltration is carried out once the coupling has been completed. |