Complex Chromogen Systems Applied on Leather

The restrictions included in the environmental legislation have oriented the leather dyes market toward metal-complex dyes class with lower ecological impact. The main aim of the paper was to obtain new acid azo （1：2） metal-complex dyes, conditioned in ecological microgranular form, with good physico-chemical and coloristic performances, with a minimum impact on the environment and on the human health. The synthesized metal-complex dyes are based on o,o＇-dihydroxy-azo system and they are dyeing leather in ruby, reddish-violet, violet, blue, olive and gray shades. The synthesis involved specific processes like diazotizing, coupling, complexing, filtration, drying and grinding. The conditioning of the synthesized dyes was achieved by micro-granulation in order to obtain a new commercialized presentation form. For experiments raw materials were used with reduced eco-toxicological risks. We＇ve obtained acid azoic （1：2） symmetrical and asymmetrical metal-complex dyes; metal is chromium or cobalt. The new structure