New Fluoropolymer Latex Clearcoat Technology for the Enhanced Protection of Heat-Sensitive Substrates

By Celine Autran, Ravi Gupta, Kurt Wood

Clearcoats containing UV absorbers are widely used to extend the lifetime of UV-sensitive materials, such as wood and plastic substrates, as well as UV­-sensitive pigments and binders in basecoats ( notably in the automotive industry). There are two basic types of UV absorbers that are commercially available for clearcoats: organic and inorganic.

Organic UV absorbers are typically designed for use in solution, so they have outstanding transparency in clearcoats; however, they also have two important limitations. First, the UV absorbers themselves are somewhat susceptible to photochemical attack, and so cannot be reasonably expected to provide quasi-permanent UV pro­tection. Second, as materials in solution, the precise grade of UV absorber used must be matched correctly to the formulation’s solvency properties, in order to get an appropriate amount of UV absorber into the final clearcoat film.

For many water-based formulations, the choices for organic UV absorbers are particularly limited, as dispersibility rather than solvency becomes the important factor for good performance. However, with these limitations under­stood, the ability of organic UV absorbers to extend the lifetime of coatings can often be quite dramatic.