| 摘要 |
A substrate of glazing material carries a multi-layer coating which comprises a reflective layer of silver sandwiched between a transparent undercoat and a transparent overcoat. The undercoat for the silver layer comprises at least one layer of a metal oxide selected from tin oxide, titanium dioxide, aluminium oxide, bismuth oxide and a mixture of two or more thereof, over which is deposited a layer of zinc oxide having a thickness not greater than 15 nm. The overcoat for the silver layer comprises a layer of an oxide of a sacrificial metal selected from the group consisting of titanium, aluminium, stainless steel, bismuth, tin and mixtures of two or more thereof, which is formed by initial deposition of the sacrificial metal and its conversion to oxide. For forming a low emissivity coating with good light transmission, the silver layer is 8 to 12 nm thick. A specific multi-layer low emissivity coating is formed by depositing the following layers, starting from the substrate surface: Undercoat 3 nm titanium dioxide 20 nm tin oxide (SnO2) 13 nm zinc oxide Reflective layer 10 nm silver Overcoat 3.5 nm titanium for conversion to titanium dioxide 22 nm tin oxide 12 nm titanium dioxide. |
