The Affinities of Vat Dyes in Relation to their Constitutions

The affinities of a series of anthraquinone and carbocyclic vat dyes have been determined. The attraction for the fibre appears to arise from two main causes‐ polar or hydrogen bonding and non‐polar or van der Waals forces. The results are analysed in terms of these. It is found that, in a series of related compounds, a relationship exists between the affinity and the van der Waals forces as determined by the extinction coefficients of the dyes.