Synthesis of cationized anthraquinone dyes and their dyeing properties for meta-aramid fiber

Due to compact structure of meta-aramid fiber caused by the intermolecular hydrogen bondings of amide groups, the degree of crystallinity increased, thus its poor dyeing properties arises. Among commercial dyes used in many previous researches, the basic dyes showed comparatively higher exhaustion yields as comparing to those of disperse dyes and acid dyes. The anthraquinone moiety was adopted for good performances of light fastness on meta-aramid fiber. In this study, eight of anthraquinone dye was synthesized. The three of them were obtained from chloro-anthraquinone, by Ullmann reactions with the corresponding heterocylic residues such as morpholine and one of them was obtained from lueco quinizarine by condensation with the corresponding heterocylic residues. The others were prepared by quaternization from dyes above. The synthesized disperse and cationic dyes were dyed on meta-aramid fibers and investigated for their build-up dyeing properties and wash fastness.