COATED ALUMINIUM WORKPIECE

摘要

Aluminium alloy sheet having on a surface an anodic oxide film and an overlying coating consisting essentially of at least one adhesion promoter excluding silanes. Sheet for architectural use carries a paint layer over the adhesion promoter coating. Sheet for automobile use may carry an electroconductive paint primer layer over the adhesion promoter coating. Preferred adhesion promoters are polyacrylic acid and pretreatments containing Cr, Mn, Mo, Si, Ti, Zr and F values.