Method: by 4-Aminophenol and 4-(4-Aminophenyl)benzenamine and 8-Aminonaphthalene-1-sulfonic acid condensation product and derived indophenol?Copper sulfate monohydrate in the presence of Sodium polysulfide and heating. In the vulcanization reaction to add Molybdic acid can get color is yellow dye (GP 590873)
