Short duration hot seal for anodized metal surfaces

摘要

PCT No. PCT/EP96/04373 Sec. 371 Date Apr. 20, 1998 Sec. 102(e) Date Apr. 20, 1998 PCT Filed Oct. 9, 1996 PCT Pub. No. WO97/14828 PCT Pub. Date Apr. 24, 1997A process for sealing anodized metal surfaces is characterized by bringing the anodized metal into contact with an aqueous solution at a temperature from 75 DEG C. to the boiling point of the solution for a time equal to from 0.5 to 2 minutes per micrometer of anodized layer thickness. The solution contains: a) from 0.0001 to 5 g/l of one or more alkali metal and/or alkaline earth metal ions and b) from 0.0005 to 0.5 g/l of one or more organic acids selected from: polycarboxylic acids with from 3 to 6 carboxyl groups; phosphonic acids; and/or polyphosphinocarboxylic acids, the solution containing a greater amount of metal ions of group a) than is needed to insure complete neutralization of the acids of group b).