| abstract |
The invention relates to a condensation product that can be obtained by the reaction of a1) at least one aromatic or heteroaromatic, said aromatic or heteroaromatic being substituted with at least one hydroxy group (-OH) and at least one carboxy group (-COOH), the hydroxy and carboxy groups being present in the form of salts, a2) at least one carbonyl compound, a3) optionally at least one sulphonating agent, a4) optionally at least one urea derivative, and a5) optionally at least one additional aromatic or heteroaromatic, or a physiologically compatible salt thereof, on the condition that component a1) is not salicylic acid or sulphosalicylic acid, if component a4) is melamine. |