2P-112 : Flexible, but durable nanosol-coated cover window for foldable display

In this study, we present sol-gel based hard coating material for transparent and flexible cover window. We synthesized random-network silsesquioxane nano sol through sol-gel reaction to obtain mechanical toughness and flexibility at the same time. The synthesized silsesquioxane nano sol was coated on PET film and UV-cured to make solid hard coating film. The mechanical property and flexibility of nano sol based hard coating was measured by AFM, UTM, pencil hardness tester and film bending tester. The resultant hard coating layer presents high flexibility over 100k cycle folding at 1R folding radius without any crack. In addition, it shows 9H pencil hardness with 1050MPa of indentation hardness.