ALKALINE AQUEOUS SOLUTION FOR IMPROVING CORROSION RESISTANCE OF A CR(III) CONVERSION COATING AND METHOD FOR PRODUCING SUCH COATING AND ITS USE

摘要

This invention relates to a composition and a method for preparing an organic protective coating on a Cr(lll) conversion layer which is localized on aluminium or an aluminium alloy to enhance corrosion protection. The composition is an alkaline aqueous solution which contains at least one corrosion inhibitor, a buffering agent and at least one organic film former. According to the method of the present invention, the composition is used for post-treating of a Cr(lll) conversion layer on aluminium or an aluminium alloy and on anodized alumin¬ ium or an anodized aluminium alloy.