| abstract |
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. |