Disazo sulfophenylpyrazolone-sulfostilbene dyes

摘要

A new group of disazo sulphophenylpyrazolone-sulphostilbene compounds useful as orange-hued dyes for cellulosics having excellent color stability over a wide range of pH. When mixed with certain direct blue dyes and also with combinations of certain direct blue and yellow dyes, they form dye mixtures that are highly soluble in water and can effectively function as uniquely stable liquid black paper dyes which do not change hue over a wide range of pH conditions, thereby simplifying the problem of the dyer in matching and maintaining uniformity of hue.