ANILINE-BASED OIL-SOLUBLE AZO DYES

摘要

Azo dyes of the formula R1, R2 and R3 independently denote hydrogen, C1-C4-alkyl or C1-C4-alkoxy, R4 denotes C1-C8-alkyl and R5 denotes C2-C8-alkyl which is substituted by hydroxy and may be interrupted by 1, 2 or 3 oxygen atoms, provided that the total number of carbon atoms in the radicals R4 and R5 is at least 5, mineral oils containing one or more of said novel dyes and the use of sand dyes for marking mineral oils.