Patent ID: 9328423
Filing Date: 2016-05-03
CPC Classification: C23C

Claim Text:
1. A hexavalent chromium free trivalent chromate solution for an aluminium or aluminium alloy, the solution consisting of a source of the trivalent chromium, a source of a metal selected from the group consisting of zinc, cobalt, and a combination thereof, a source of fluorine, a pH adjuster and water, in which the concentration of a trivalent chromium is in the range of from 1.1 to 20 g/L, the concentration of zinc, when present, is in the range of from 0.05 to 20 g/L, the concentration of cobalt, when present, is in the range of from 0.1 to 50 g/L, the concentration of fluorine is in the range of from 0.5 to 10 g/L, the pH is in the range of from 1.0 to 4.0, and the pH adjuster is selected from the group consisting of inorganic acids and alkaline agents.