| abstract |
Heavy metal complexes can be prepared from azo compounds that contain a heterocyclic diazo component containing a complex-forming group such as hydroxyl, carboxyl, alkoxy or amino, or containing a hetero nitrogen atom able to form a coordinate bond, exemplified by quinolinyl and benzthiazolyl. The coupling component is 5-halogeno-2,3-dihydroxypyridyl where halogen is preferably chloro or bromo. The dyestuffs are useful, inter alia, for dyeing natural and synthetic polyamides such as wool and nylon. The dyeings obtained are uniform, are resistant to acid and alkali, are fast to light and to rubbing and barely change their appearance in artificial light. |