Patent attributes
The present invention provides smooth and even ultraviolet (UV) cured powder coatings for wood comprising one, two or three layers of one or more waterborne stains, or clear or tinted waterborne basecoat coatings and one or more topcoat layers of clear or tinted clear powder coatings made from one or more than one free radical UV curing resin, one or more than one photoinitiator, and one or more than one post-blend dry flow additive, such as fumed alumina. The coatings of the present invention have a natural wood appearance, are foam free and fully coat substrates at powder coating thicknesses ranging from 0.5 mil (12.7 μm) to 2.0 mil (50.8 μm). Accordingly, the coatings will fully and evenly coat uneven, beveled and/or routered substrate surfaces, including open grain natural wood substrates, such as oak. In addition, the present invention provides a method for making coatings comprising applying one or more waterborne stain to the wood to form a stain layer, drying or curing the said stain layer, sanding or grinding to de-nibb the said stain layer, applying clear or tinted UV curing coating powder to the stained substrate, flowing out the applied coating powder to form a continuous film, and UV curing the film formed from the powder.
