ABSTRACT
Abstract: Aniline in its hydrochloride form goes on attaching with multiple such hydrochlorides stepwise through progressive oxidation to develop jet black shades finally, called oxidation black. The process is cumbersome but important to produce cheap bright black shades on cellulosics. All the three methods of formation of oxidation black, viz. direct black, aged black and steam black are associated with tendering of cellulose. Diphenyl black is another superior black with less or no tendering – but costlier – is produced from diphenyl amine.
