Syntheses of several dyes having carbazide group, -CON
3, have been made by use of the following method. Reaction of 1 mole p-, m- or o-aminobenzhydrazide, 2 moles sodium nitrite, and hydrochloric acid gave carbazide benzenediazonium chloride and coupling of this with various coupling agents gave dyes. The aqueous solution of these dyes in the presence of sodium chloride was used for dyeing of cellulosic fiber at room temperature, then an addition of sodium carbonate gave an ester-like binding as indicated in equation (1) by the reaction of OH group in cellulose: D-CON
3+HO-Cellulose D-COO-Cellulose + NH
3(1) where D = dye matrix having sulfonyl group. On the other hand, heating of dyed product in a neutral or weakly acidic solution gave a dye molecule of urethan combination as shown in equation (2) from OH group of cellulose fiber: D-CON
3 D-N=C=O + N2
2 D-N=C=O + HO-Cellulose → D-NHC00-Cellulose (2) A group of these dyes was named as a diact Color “C” by the author.
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