Innovative, scratch proof nanocomposites for clear coatings

The incorporation of inorganic nanoscale particles into an organic matrix is of interest in many applications. Specific combinations of properties in coatings such as transparency and wear resistance can be obtained by using nanoparticles. The aim of the project is the development of high-grade transparent lacquers to provide clear coatings for mobile phones, skis, snowboards and helmets. The incorporation of nanoparticles produced by the process of high-temperature flame synthesis should improve the scratch resistance while transparency and gloss remain constant. Non-aggregated silica nanopowder with an average particle size of less than 100 nm has been produced by the process of flame synthesis. Following surface-modification with different silanes, e.g. with reactive coupling groups, nanoparticles were dispersed in a two-package polyurethane lacquer using high-speed dissolvers and ball mills. Total volume pigment contents of up to 23% were attained. Nanolacquers with different nanoparticle contents were applied to glass sheets in order to investigate changes to their scratch resistance and transparency. (c) 2004 Elsevier Ltd. All rights reserved.