US 11,865,574 B2
Powder coating method and coated article
Michael Denis McCormick, Attadale Perth (AU); Oriol Aixala-Marimon, East Fremantle Perth (AU); and Frank Zimmermann, Frontenhausen (DE)
Assigned to Akzo Nobel Coatings International B.V., Amsterdam (NL)
Filed by Akzo Nobel Coatings International B.V., Amsterdam (NL)
Filed on Jan. 7, 2020, as Appl. No. 16/736,291.
Application 16/736,291 is a continuation in part of application No. PCT/NL2018/050446, filed on Jul. 6, 2018.
Claims priority of application No. 2019197 (NL), filed on Jul. 7, 2017.
Prior Publication US 2020/0139400 A1, May 7, 2020
Int. Cl. B05D 1/12 (2006.01); B05D 3/06 (2006.01); B05D 5/02 (2006.01); B05D 7/06 (2006.01); B05D 7/00 (2006.01); B27N 7/00 (2006.01); C09D 5/03 (2006.01)
CPC B05D 1/12 (2013.01) [B05D 3/067 (2013.01); B05D 5/02 (2013.01); B05D 7/06 (2013.01); B05D 7/542 (2013.01); B27N 7/005 (2013.01); C09D 5/03 (2013.01)] 8 Claims
 
1. A method of powder coating an article, comprising:
a) providing a substrate coated with a first powder coating layer, and heating the first powder coating layer to a temperature of below 140° C. so as to at least partially melt or soften the first powder coating layer, such that the first powder coating layer is not or only partially cured;
b) applying a second powder coating layer on the first powder coating layer, the first powder coating layer being in a non-cured or only partially cured state,
c) curing the first powder coating layer and second powder coating layer by heating the substrate including the first and second powder coating layers to a temperature of below 140° C. or subjecting it to UV radiation,
wherein the material of the first powder coating layer comprises a flow agent so as to achieve a smooth powder coating layer, the term smooth defining a surface substantially free from irregularities, roughness or projections and the material of the second powder coating layer comprises a texturing agent so as to achieve a textured powder coating layer, the term textured defining a surface having varying degree of roughness and wherein the first powder coating layer and the second powder coating layer both are based on low-temperature curing powder coating compositions that cure at temperatures below 150° C., and
wherein the coating has a surface with a gloss valve of less than 40 gloss units measured at 60° C., and an average roughness Sa of less than 1.50 μm.