Abstract
The dyeing properties of acid azo dyes having the same skeletal structure as p-X-aniline→γ-acid (2-amino-6-sulfo-8-hydroxynaphthalene) (alkali- and acid-coupling) were determined qualitatively, where X are H, SO3H, SO2NH2, COOH, COOC2H5, Cl, CH3, OCH3, OC2H5, NO2, NH2, NHCO CH3 and NH-_??_, respectively.
The absorption spectra of aqueous solution of alkali-coupling dyes (γA) and acid-coupling dyes (γS) in visible region are very different in shape, γA have two absorption maxima and γS have one maximum, then the shade on wool dyeings of the former are much duller than that of the latter.
The dyeing rate of γS on wool colth from boiling bath is larger than that of γA. All of these dyes used have a considerable affinity to wool from neutral dyeing condition, especially X=H, Cl, NO2.
The light fastness of dyeings of γS is better than that of γA, and the wash fastness is vice versa.
