Method of sealing oxidized aluminum surfaces with aqueous solutions of polycarboxylic acids

摘要

In the process of treating an aluminum or aluminum alloy surface which comprises anodically oxidizing the surface and subsequently sealing the surface, the improvement consisting of sealing in an aqueous solution at a temperature between 90 DEG C and the boiling temperature of the solution, said aqueous solution having a pH value of from 4 to 8 and containing from 0.0005 to 0.2 gm per liter of cycloaliphatic or aromatic polycarboxylic acid or water-soluble salt thereof, said cycloaliphatic or aromatic polycarboxylic acid having 4 to 6 carboxyl groups.