SHORT-TERM HEAT-SEALING OF ANODIZED METAL SURFACES WITH SURFACTANT-CONTAINING SOLUTIONS

摘要

Sealing an anodised metal surface comprises: (i) contacting the anodised metal for 0.5-2 minutes per micrometer anodised layer thickness with an aqueous solution having a temperature of 75 deg C to the boiling point and a pH of 5.5-8.5; and (ii) using an aqueous solution including 0.0004-0.05 g/l cationic, anionic or non-ionic tenside and 0.0005-0.5 g/l organic acids selected from cyclic polycarboxylic acids with 3-6 carboxyl groups and/or phosphonic acids. Also claimed is an aqueous concentrate for preparation of the aqueous solution used in the above process.