Black 7984, Food Black 2, or C.I. 27755, is a brown-to-black synthetic diazo dye. It is often used as the tetrasodium salt.
Production In the synthesis of Food Black 2, sulfanilic acid 1 is first reacted with sodium nitrite under acid diazotization conditions, and the resulting diazonium salt 2 is subjected to azo coupling with 8-aminonaphthalene-2-sulfonic acid 3. The monoazo dye 4 is subsequently diazotized to form the diazonium compound 5 and then reacted with 3-amino-5-hydroxynaphthalene-2,7-disulfonic acid 6 to yield the diazo dye 7.
Use Under the designation E 152, Food Black 2 was approved in the EU as a food colorant by Directive 62/2645/EEC until the end of 1976.Aufgenommen durch die EU-Richtlinie 1962 2645.Gestrichen durch die EU-Richtlinie 1976 399.
Food Black 2 is approved in the EU under Regulation (EC) No 1223/2009 as a colorant in cosmetics.EU-Verordnung 2009 1223, Anhang IV: Liste der in kosmetischen Mitteln zugelassene Farbstoffe, Laufende Nummer 52. Its use as a hair dye is not permitted.EU-Verordnung 2013 344, Anhang II: Liste der Stoffe, die in kosmetischen Mitteln verboten sind, Laufende Nummer 1354.
Together with Acid Yellow 23 and Acid Red 52, Food Black 2 is used in inks for inkjet printing.
Black 7984 is also used in cosmetics.
See also Carbon black
References