| abstract |
Fibrous materials of polyacrylonitrile, mixed polymers containing acrylonitrile or cellulose acetate are dyed or printed with a cyanine dyestuff of the formula <FORM:0897196/IV (c)/1> in which A and B are supplementary members of a 5- or 6-membered heterocyclic ring, which can be substituted, R1 and R4 are alkyl radicals, R2 and R3 are hydrogen atoms or nitrile groups or other substituents usual in cyanine chemistry, R5 is a dialkyl-substituted amine radical or an aryl, alkoxy or aryloxy radical or a nitro group or another substituent usual in cyanine chemistry, D is an arylene radical, X is an organic or inorganic anion and n, m and o are 0 or 1. The dyebaths or printing pastes may contain the usual levelling or dispersing agents and dyeing may be effected from an acid or neutral bath at the boil. Numerous dyestuffs are specified and examples of dyeing and printing are given. Specifications 897,195 and 897,197 are referred to. |