The effect of basecoat pigmentation on the scratch resistance and weathering performance of an acrylic–melamine basecoat/clearcoat automotive finish

Scratch resistance of an acrylic/melamine clearcoat (on the black and silver basecoats) was studied by means of laboratory simulator carwash and nano-scratch tests before and after carrying out a weathering test. The scratch morphology was studied by scanning electron microscope (SEM). Gonio-spectrophotometer and micro-indentation were utilized to investigate appearance changes and mechanical properties of the clearcoats. Results showed that scratch resistance of the silver sample was higher than the black one. The scratch resistance of the black and silver samples was improved at short exposure times. A decrease in scratch resistance of the coatings was obtained at long times.

► Effects of the basecoat pigmentation on an automotive clearcoat friction behavior.
► Increased scratch resistances at low xenon test exposure times.
► More fracture behavior of scratch produced on the silver sample than that of black sample.
► Scratches can be healed during the weathering test.
► Higher scratch resistances of silver sample than that of black sample were obtained.