DIRECT DYEING OF CELLULOSE

Abstract

The following results were obtained:(1) Weight of dye per 1kg of saturated solution for Congo Red first increases with increasing weight of dye added per 1kg of solvent (water), but at the end this value approaches to the constant value.(2) The order of decreasing solubility of the dye is; Congo Red (C. I. No.370) Nippon Sky Blue (C. I. No.520)>Aizen Direct Blue BBH (C. I. No.406)>Diamine Blue 3B (C. I. No.477)>Dianil Azurine G (C. I. No.502)>Benzopurpurine 4BKX (C. I. No.448)>Azo Blue (C. I. No.463)>Azoorseillin.(3) The affinity of these dyes for cotton first increases with decrease in the solubilities, and then decreases. The abnormally low solubility of Azoorseillin and Azo Blue is to be attributed to the chelate structure.