What do you get when you cross a mylar film with given compounds, polymers and UV light? The answer, in this patent application, isn't clear—it's blue. And it indicates when a sunscreen has run its protective course.
Polymer, mylar film and method for indicating maximum UV exposure
WIPO Patent Application WO/2016/048426
Publication date: March 31, 2016
Assignee: Genesis Laboratories Inc.
Described in this patent application is a composition including a UV filter and an indicator that responds to reduced UV protection. Specifically, the cream/lotion/gel formulas include a hydro-alcoholic solution and anhydrous compound, in addition to polymer and mylar films.
The compounds and formulations have an aesthetically pleasant, clear application to skin but turn blue when the limit for photon absorption has been reached, according to the SPF factor on the indicator itself, or accompanying sunscreen. This color change tells the user to re-apply the product.
Patent accessed April 4, 2016.