Reaction solution for producing colored passivation film on zinc and its alloys, e.g. on iron or steel, is based on aqueous acid solution containing trivalent chromium ions and contains quinoline dye, preferably quinoline yellow

摘要

Reaction solution for passivation of zinc (Zn) and its alloys, consisting of an aqueous acid reaction solution (I) with trivalent chromium ions, Cr(III), also contains quinoline dye(s) (II). Independent claims are also included for: (1) process for passivating Zn (alloys) based on (I), with addition of (II); (2) passivation film for Zn (alloys), which is as free as possible from Cr(VI), is colored by using a passivation solution with added (II) and provides corrosion protection of not less than 50 hours in the salt spray cabinet to DIN 50021 SS.