Method for improving the fastness of dyeings with basic dyes on cellulosic substrates

摘要

The fastness properties of basic dyeings on cellulosic substrates are improved by treating the substrate with a fixing agent comprising a precondensate or mixture of (A) the reaction product of an amine with cyanamide, dicyandiamide, guanidine or biguanidine, or, (B) a quaternary polyalkylene polyamine with (C) formaldehyde and/or, (D) an N-methylol compound optionally together with (E) a catalyst, e.g. MgCl2. The fixing agents are normally applied as an aftertreatment, with a subsequent heat-curing step.