| Abstract: | A member of the new series of cationic reactive dyes containing a thioether‐ethylsulphone grouping referred to in Part 1 of this series has been applied to nylon at pH 3–10. The dye is water soluble and shows excellent substantivity for nylon 6.6 when dyed at the boil at pH 8–10. Under alkaline conditions, gradual β‐elimination back to the vinylsulphone dye occurs and covalent bond formation quickly takes place with the fibre; the higher the pH the more rapidly this occurs. Dyeings carried out at pH 10 showed very good brightness and levelling, together with good wash fastness. The light fastness of dyeings at moderate depth was 4–5 on the Blue Wool scale. |
