One-bath dyeing of PET/cotton blends with azohydroxypyridone disperse dyes containing a fluorosulfonyl group

Azohydroxypyridone disperse dyes containing a fluorosulfonyl group were dyed on PET/cotton blends and their dyeing and fastness properties were investigated. Specially, the azohydroxypyridone dyes containing a nitro group in place of the fluorosulfonyl group in the para position to azo group were synthesized in order to compare their dyeing and fastness properties on PET/cotton blends with those of fluorosulfonyl-substituted analogues. As these dyes can be alkali cleared in the same bath, a one-bath dyeing method was used and the results were compared with that of a conventional two-bath dyeing method. In particular, the cross-staining of cotton was studied in order to assess their suitability for the one-bath dyeing of PET/cotton blends.