A study on the depth distribution of melamine in polyester-melamine clear coats

摘要: Abstract The depth distribution of melamine in polyester-based coatings was investigated by XPS (X-ray photoelectron spectroscopy) as well Raman analysis on cryo-ultra-low-angle microtome (cryo-ULAM) prepared hot dip galvanized (HDG) steel panels. Additionally, free standing films were analyzed the air/coating and coating/substrate interfaces: for polyester/melamine ratios ≤20 wt.% concentration equal both sides films, which is accordance with literature. This finding could not be confirmed applied HDG panels that revealed a higher amount surface-near region. In addition various types non-linear gradients have been detected over spectroscopy. behavior all irrespective binder chemistry curing temperatures range 220–260°C. Whereas previous studies mainly focused where gradient properties are more pronounced, this work tries to fills gap towards lower contents, greater relevance industrial coatings. According these results, qualitative model has established, explains observed basis transport phenomena crosslinking kinetics within process. also agreement experimental findings from works.