Preparation of functional coatings for display glass applications by sol-gel derived techniques

Abstract

Thin glasses are very important for display applications. If high bending strength is required, state-of-the-art technologies cannot be applied due to the small thickness. SiO2 coatings derived from tetraorthosilicate and also from a methyl modified silane in combination with a nanoparticulate silica sol are applied to 0 5 nn thick soda-lime glasses by dipping and are fired at 500°C. The bending strength of the glass (double ring method) is increased from about 450 MPa to 1100 MPa by a combination of filling and clamping of the micro flaws in the glass surface. An organic-inorganic coating of only 10 µm in thickness is introduced, which can protect 2 mm thick float glass with extremely high bending strength (600 MPa) completely against the mechanical load of a sand falling test, whereas the bending strength of uncoated float glass is decreased down to 10 % of its initial value by this test. In addition, coatings with optical functions, useful for display applications like antireflective properties, NIR reflectance or colour neutral absorbance of visible light for contrast enhancement, are introduced briefly.