Process for the dyeing in a gel state of fibrous articles spun from acrylonitrile polymer solutions in organic solvents.

摘要

A wet-spun never-dried fibre material in the gel form comprising an acid-modified homopolymer or copolymer of acrylonitrile (PAC fibre) is advantageously dyeable with colour-fast results using soluble dyes which have in their molecule a plurality of groups, specifically more than one quaternary grouping and/or an uncharged strongly basic grouping, which act basic toward the acid groups of the fibre substance. The chromophore of this colorant can come from the category of the monoazo or disazo dyes, the methine, azamethine or diazamethine dyes or the naphthalactam dyes. The dyeing of the never-dried fibre is advantageously carried out continuously or batchwise from a solvent-containing dyebath which in addition to water contains portions of an organic solvent, specifically the solvent used for spinning the polymer the drawing of the fibres can take place before, during or immediately after the dyeing process. Owing to their special nature, the fast-dyeing dyes of the aforementioned type give optimum rates of fixation in the dyeing of PAC gel fibre, and do not cause any marked staining of machine parts and working baths, for example drawing or aftertreatment baths, due to leached dye in the subsequent production stages. Investigations of the fibre penetration, the rate of fixation and the resulting fastness properties, such as the wet fastness, did not reveal any disadvantages compared with conventional dyes.