Study of degradation mechanisms of a paint coating during an artificial aging test

The degradation of a paint coating applied to the backs of mirrors was stud ied using infrared spectroscopy during a standard test. This analytical too l showed that the protective coating is subject to alterations within a thi ckness ranging from the surface to at least 7.65 mu m. The effects of the n ormalized test lead to the dissolution of the calcium carbonate extenders a nd to chemical modifications of the paint binder. These phenomena are respo nsible for the progressive erosion of the paint coating surface and for a w eakening of its protective properties. The paint film's degradation lead to random corrosion of the metallic layers that make up the mirror backs. (C) 1999 Elsevier Science Ltd. All rights reserved.