Relation between chip resistance and mechanical properties of automotive coatings

This work addresses the correlation between stone-chip resistance and mechanical properties of automotive solid colour coating systems. Single-impact tests, which are believed to realistically simulate chipping due to stone impact, were performed to investigate eight different coating systems. Additionally, conventional tests on chip resistance currently used in automotive industry were performed. Results were related to mechanical properties of the coatings, measured by dynamic mechanical thermal analysis and double cantilever adhesion test. It is found that coating systems with a low glass transition temperature for the primer have better stone-chip resistance.