Coated articles demonstrating electromagnetic radiation transparency and method of mitigating contaminant build-up on a substrate

A method of mitigating contaminant build-up on a substrate that is transparent to electromagnetic radiation having a frequency of 22 to 81 GHz, comprising:

• (1) applying a first coating comprising a pigmented, curable film-forming composition to at least a portion of the substrate to form a coated substrate;
• (2) applying a transparent, curable film-forming composition to at least a portion of the coated substrate formed in step (1) prior to substantially curing the first coating to form a multi-layer coated substrate, wherein the transparent, curable film-forming composition comprises:
• (a) a first film-forming polymer prepared from at least one hydrophobic monomer and having reactive functional groups, wherein the first film-forming polymer (a) is present in the curable film-forming composition in an amount of 20 to 40 percent by weight, based on the total weight of resin solids in the curable film-forming composition;
• (b) a second film-forming polymer different from the first film-forming polymer (a) and prepared from at least one hydrophobic monomer, wherein the second film-forming polymer (b) is present in the curable film-forming composition in an amount of 0.5 to 15 percent by weight, based on the total weight of resin solids in the curable film-forming composition;
• and
• (c) a curing agent comprising functional groups reactive with the reactive functional groups in (a);
• and
• (3) heating the multi-layer coated substrate formed in step (2) to a temperature and for a time sufficient to cure all the film-forming compositions.

A method of mitigating contaminant build-up on a substrate that is transparent to electromagnetic radiation having a frequency of 22 to 81 GHz, comprising:

• (1) applying a curable film-forming composition to at least a portion of the substrate to form a coated substrate, wherein the curable film-forming composition comprises:
• (a) a first film-forming polymer prepared from at least one hydrophobic monomer and having reactive functional groups, wherein the first film-forming polymer (a) is present in the curable film-forming composition in an amount of 20 to 40 percent by weight, based on the total weight of resin solids in the curable film-forming composition;
• (b) a second film-forming polymer different from the first film-forming polymer (a) and prepared from at least one hydrophobic monomer, wherein the second film-forming polymer (b) is present in the curable film-forming composition in an amount of 0.5 to 15 percent by weight, based on the total weight of resin solids in the curable film-forming composition;
• and
• (c) a curing agent comprising functional groups reactive with the reactive functional groups in (a);
• and
• (2) heating the coated substrate formed in step (1) to a temperature and for a time sufficient to cure the film-forming composition.