Multilayer coating for defrosting glass

摘要

This invention is directed to a glass substrate having deposited thereon an electroconductive coating useful for defrosting the glass. The coating comprises three layers. The first layer deposited on the glass is selected from the group consisting essentially of: (a) silicon oxide and (b) silicon nitride and it is deposited on at least a portion of a surface of the glass substrate. The second layer comprises an electrically conductive material selected from the group consisting essentially of (a) aluminum doped zinc oxide and (b) gallium doped zinc oxide. It is deposited on at least a portion of the first layer in a thickness of at least 1 micron. This second layer has a sheet resistance of less than 20 ohms per square. A third layer comprising a protective material is deposited on and is at least coextensive with the second layer. It is deposited in a thickness of at least 10 microns and is selected from the group of materials consisting essentially of: (a) fluorine doped tin oxide, and (b) silicon nitride. This third layer has a refractive index within 10% of that of the second layer./!