STUDIES ON DISPERSE DYES

Abstract

Eighty-nine disperse dyes of aminoanthraquinone series were synthesized and their dyeability and fastness were examined. Relationship between structure and dyeability is discussed in terms of a/o and molecular size of dye. The a/o (inorganic property/organic property) is calculated by the use of Fuijita's conceptional diagram. The a/o is equivalent to hydrophility/hydrophobity. The average a/o value of dyes, having good dyeability on acetate, is about 1.25 and this is consistent with that of secondary cellulose acetate. It seems that the molecular size of dyes which can diffuse into cellulose acetate is less than about 13 A in normal dyeing process. The light fastness of dyes decreases in the following order. 1-Amino-4-hydroxyanthraquinones>1, 4-Diaminoanthraquinones>1, 4, 5-Triamino-8-hydroxyanthraquinones>1-Aminoanthrquinones>1, 4, 5, 8-Tetraminoanthraquinones. An electron attractive N-substituent, such as β-chloroethoxycarbonyl group, increases the light fastness and an electron donating group, such as β-hydroxyethyl group, decreases the light fastness. It seems that the a/o ratio of dyes, having poor wash fastness, is more than 1.25, and the molecular size of the dyes is less than about 11.0A.