The present work aims to investigate and develop a series of coumarin dyes containing nitro or amino benzimidazole group for the polyester and nylon fabrics and so on. Dye A was obtained by the condensing 2-benzimidazolyl acetic acid with4-N, N-diethylamino-salicylaldehyde. Dye B was obtained by nitration with Dye A and nitric acid, and Dye C was obtained by reduction with Dye B and Sodium Sulfide. These dyes were dyed on polyester (PET, PTT), Nylon, Wool and Cotton with different pH value (3, 4, 5, 6) and fastness properties evaluated. The fastness properties of all the dyed samples were in accord with commercial requirements except.
