Verfahren zur Herstellung gummielastischer Faeden und Fasern mit verbesserter Anfaerbbarkeit fuer basische Farbstoffe

摘要

Pre-polymer is made by reacting a linear polyhydroxyl compound (OH value 35 - 120) with up to 300% excess of a di-isocyanate. This is reacted with a mixture of a conventional low m.w. chain extender (equivalent to 80 - 130% of the NCO groups) and the equivalent of 2 - 50% of the NCO groups of a bifunctional organic compound containing one or more sulphonic acid or disulphon-imide groups or their salts with alkali metals, ammonium or trialkylammonium:- -SO3M or -SO2-N(M)-SO2- an ammonium or trialkylammonium group, to give a polyurethane of the type:- -CO-NH-Y-NH-CO-X1-R-X2-NH-CO-Y-NH-CO-.