METHOD OF PRODUCING DIRECT BLACK DYE C Russian patent published in 2011 - IPC C09B41/00 

FIELD: chemistry.

SUBSTANCE: invention relates to production of azoddyes, particularly common direct black dye C. The disclosed method of producing direct black C dye involves the following steps: 1) preparation of an aqueous suspension of aminophenyl paramine acid in the presence of a micellar solution of silver and quartz nanoparticles, 2) diazotation of the obtained suspension with aminophenyl paramine acid in the presence of silver and quartz nanoparticles, 3) azo coupling the obtained diazo compound with Gamma-acid in the presence of nickel nanoparticles, 4) diazotation of the obtained diamine compound in the presence of iron nanoparticles and nickel-chromium nanoparticles to obtain a solution of a bis-diazo compound, 5) preparation of a solution of 1,3-phenylenediamine in the presence of a micellar solution of silver in chemically pure isooctane solvent and highly reactive carbon nanoparticles, obtained through cold decomposition, 6) azo coupling 1,3-phenylenediamine with the bis-diazo compound in the presence of nanoparticles fed into the step with suspensions of the bis-diazo compound and 1,3-diphenylenediamine. Further, the obtained dye is exposed to vibromechanical effects, undergoes decantation and drying.

EFFECT: invention improves environmental friendliness of the process owing to reduction of the amount of waste water, simplification of technology owing to carrying out the process at 18-20°C and shortening duration of the process to 21 hours while increasing colour concentration of the dye by 20% and obtaining a dye with a more saturated shade of blue colour.

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