Coating rehabilitation onto deteriorated anodic oxidation aluminum alloy building materials Part2

Abstract

In case of anodic oxidation aluminum alloy materials have been applied to a building exterior use, it is pointed out that it has been deteriorated over time like change in color, adhesion of dirt and localized pitting corrosion. This paper describes coating rehabilitation method onto the deteriorated aluminum alloy building materials surfaces based on experimental results. Main conclusion is as follows. 1) According to electron microscope observation and elemantary analysis of the aluminum surface and cross section that has been deteriorated with 5000-hour-sunshine carbon arc type accelerated weathering, it is presumed that the surface is smoothing because of slight hydration. The surface haydration is suggested because the suface has glossiness degradation however the surface change in color is not clear. It is considered that the gloss reduction on the surface is not a change in composition but a change to fine surface roughness. 2) The coating system that is easily soluble in aliphatic hydrocarbon-based solvent has adequate surface appearance and the hardened coating film adhesion to the aluminum surface. It is judged that the coating system is able to be applied onto the deteriorated aluminum surface. And its confirmation would be continued.