Process for spin-dyeing of acid-modified polymers of acrylonitrile by the wet-spinning procedure using quaternary ammonium or cyclammonium dyestuffs of low M value and high cation weight having two or three said ammonium or cyclammonium groups

摘要

Improvement of a process for spin-dyeing acid-modified polymers or copolymers of acrylonitrile in which cationic quaternary dyestuffs are added to the spinning mass and spun according to the wet- spinning procedure. The improvement is characterized by using dyestuffs characterized by a migration factor M of 20 or less than 20, by a combination index K of less than 2.5 and a cation weight of more than 310. Migration factor M and combination index K are known values in the dyestuff field or can be determined. The dyestuff to be used according to the invention can belong to the most different classes of dyestuffs; they fix rapidly on the polymer, and thus they do not color, or color only to a minor extent, the coagulation, stretching and washing baths although they are soluble in water and aqueous solutions of these baths. The fibers and filaments obtained by the process of the invention have outstanding fastnesses to wet processing and, owing to the absence of dyestuff aggregates at the surface of the fiber such as occur when spin- dyeing with pigments, very good fastnesses to dry and wet rubbing. The fibers are intense, absolutely transparent and free from specks.