The use of powder coatings has been of limited use in replacing liquid coating compositions, in part, due to the high curing temperatures required. Many powder coating formulations also suffer from yellowing. Powder coatings in slurry form can be utilised and overcome many of the limitations of dry powder coatings but they can be unstable and settle upon storage at temperatures above 20°C. Aqueous coatings also suffer from requiring ramped baking conditions to achieve a coalesced and continuous film on the surface as well as containing substantial amounts of organic solvents to improve flow. This patent describes an organic solvent-free, clearcoat that can be applied by conventional application means over an uncured pigmented base coat.
展开▼
