Patent attributes
The invention relates to a high gloss car wash-resistant coating composition comprising a hydroxyl-functional binder and a cross-linker reactive with the hydroxyl groups of the binder and a method to prepare such a car wash-resistant coating. The invention further relates to the use of said coating composition, as a pigment-free top coat or a clear coat, in the finishing and refinishing of articles, for example motorcycles, cars, trains, buses, trucks, and aeroplanes. The coating composition after curing forms a coating having an initial gloss of at least 81 GU and a loss of gloss (LoG) of less than 0.18, the loss of gloss being determined by the formula (I): LoG=A+B·E′·(X)−1·10(C·ΔTg)+D·(E′)−0.5; wherein A=0.0132, B=1.0197, C=0.0113, and D=0.0566, E′ reflects the tensile storage modulus at 40° C. in GPa, ΔTg the width of the glass transition temperature in ° C., and X the cross-link density parameter in kPA/K all three parameters determined in a DMTA test at 11 Hz and a heating rate of 5° C./min.
