| abstract |
Disclosed are novel azo dyes of the structure X-N=N-C' wherein X represents the diazonium component comprising phenyl or a heterocyclic group commonly used in azo dyes and which is substituted by one or more fluorinated carboxylic or sulphonic ester groups. Additionally, X may be substituted by any of the groups commonly used in diazonium components such as nitro, cyano, halogen and the like. C' represents an aniline, tetrahydroquinoline or benzomorpholine coupler of the type commonly used in azo dyes. The dyes can be used in both the dyeing and heat transfer printing of textiles, are surprisingly bathochromic in shade, exhibit a good balance of properties such as light, crock, wash, and gas fastness, leveling, pH stability, and dyeability, and have unexpected thermal and hydrolytic stability as compared for example, to the hydrogen analogues. The dyes have particular utility on polyester fibers especially as regards lightfastness. |