METHOD FOR DYEING ARAMID FIBERS AND DYED ARAMID FIBERS

摘要

[Problem] To provide a method for dyeing aramid fibers which is applicable to any of para-aramid fibers, para-coaramid fibers, and meta-aramid fibers and by which aramid fibers are dyed in practical concentrations required for new applications of aramid fibers. The dyed aramid fibers have suffered neither considerable dyeing unevenness nor a considerable dimensional change nor a considerable decrease in material property. The dyed fibers further have satisfactory color fastness, in particular, light fastness. Also provided are dyed aramid fibers. [Solution] A dyeing method which comprises one or more dyeing operations each comprising a combination of the following steps: a dye application step in which a vat dye or a sulfur dye is applied to aramid fibers; a solvent treatment step in which the aramid fibers are treated with a treating liquid comprising a polar solvent; and a heat treatment step in which after the solvent treatment step, the aramid fibers are heat-treated according to need.