Scratch-resistant single-layer antireflective coating by a low-temperature sol-gel route

Abstract

A novel quarterwave-thick narrow-bandwidth antireflective coating has been developed for both plastic and vitreous substrates by a sol-gel route. This coating has revealed pronounced scratch- and climatic-resistances under adverse conditions. The single-layer coating consists basically of a composite material made of silica as the discontinuous phase and of a polytetrafluoroethylene-derived (Teflon<SUP>TM</SUP>) organic polymer as the continuous phase. This leads to a fluorine-containing silica-based product so-called Fluosil-coating. The coating is applied by spin or dip from specific solutions at room temperature followed by a mild and short heat treatment. In addition to remarkable abrasion and environmental resistance properties, such coatings have displayed excellent laser-induced damage threshold levels surpassing uncoated substrates. We hope such a product might open new perspectives concerning household articles, architectural optical thin-films, ophthalmic uses and so on.