The influence of organic UV absorbers on the weathering resistance of an automotive clearcoat containing surface energy reducing agent

Clearcoats containing surface energy reducing additive were exposed to the UV light in a QUV weathering test chamber. The influence of organic UV absorbers on the clearcoat resistance against photo-degradation was studied. The clearcoats degradation behaviors at various UV exposure times were investigated by a gonio-spectrophotometry analysis. Atomic force microscopy (AFM) and contact angle measurements were performed to characterize the coatings surface morphology and chemistry changes after weathering test. Results showed that addition of the organic UV absorber reduced the coating degradation resulting in lower surface morphology and easy-to-clean properties changes of the clearcoat.