Dye acid

Most of the dyes are complex structure organic or inorganic chemical compound. Consistence of acid inside the dye is not so important for all dyes. But some of the dyes are show different attitude when associate with the organic or inorganic acid solution inside dyebath of dyeing machine. These are chemical organic acid consisting of the hydrophobic dye residue and the hydrophilic auxochrome groups of dyes. The latter are mainly organic sulphonic acid (–SO3H) and/or carboxyl (–COOH) or hydroxyl groups (–OH) which, with their acid character and negative charge, make the dye residue function as a dye acid and become a dye ion inside the dye solution. Free dye acids exist, for example, in the acid dye range, either in the commercial form itself or they are formed by the addition of acid in an acidic dyebath:

chemical construction of dye acid

 he dye acid formed during the vatting of vat dyes are known as  Vat acids. Due to their ionic behavior in aqueous solution, formation of the dye acid and their alkali salts ( Dye salts) occurs in contrast to Õ Colour bases, i.e. the main group contained in cationic dyes ( Dye ions).

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