| abstract |
Azo dyestuffs of the formula <IMAGE> in which D represents the radical of a diazo component, R denotes alkyl, cycloalkyl, aralkyl or aryl, X represents a nitrile group or an optional substituted carbonamide or carboxylic acid ester group, A represents oxygen WHEREIN R1-R4denote hydrogen, alkyl or aralkyl as well as their preparation and use for dyeing of synthetic materials are disclosed. For example, polyolefines, polyvinyl polymers, cellulose 2 1/2 acetate, cellulose triacetate and particularly polyesters are dyed by customary dyeing and printing proceses to give yellow to blue dyeings and prints with good fastness properties especially fastness to light and sublimation. |