Acid Black 243

Preparation

4-Amino-3-hydroxynaphthalene-1-sulfonic acid diazo, and Naphthalen-2-ol coupled; 4-Amino-3-hydroxy-7-nitronaphthalene-1-sulfonic acid diazo, and Naphthalen-2-ol coupling, and then two single azo dye into 1:2 chromium complex.

Properties and Applications

blue ash.