Process for the preparation of the yarn obtained from aramid copolymer fibers having a low residual sulfur

摘要

The present invention relates to a method of producing a yarn comprising a polymer comprising an imidazole group, the method, by spinning the following (a) solution of the polymer in sulfuric acid, a step of bringing a plurality of dope filament , it comprises a step of the as-spun yarns of multifilaments, the aqueous acid or halide comprising (c) the as-spun multifilament yarn, halides and solidifying the (b) a plurality of dope filament I and a step of washing with an aqueous salt, or combinations thereof.