Wärmeisolierglas mit dielektrischem Vielschichtenüberzug

摘要

The invention provides a heat insulating glass plate with a multilayer coating which is fairly low in transmittance for solar radiation and fairly high in transmittance for the visible light and also for radio waves. The multilayer coating is a lamination of transparent and dielectric layers and has three essential layers in which the middle layer is higher or lower in refractivity than the inner and outer layers. The coating may have five layers in which the second and fourth layers are higher or lower in refractivity than the remaining three layers. Each layer of the multilayer coating is a metal compound film deposited by sputtering or CVD. In a first embodiment of the three-layer coating each of the inner and outer layers is formed of SnOx, ZrOx, TaOx or AlNx having a refractive index of 1.8-2.1 and the middle layer is formed of TiOx having a refractive index of 2.2-2.5. In a second embodiment, each of the inner and outer layers is formed of SnOx, TiOx, ZrOx, TaOx, ZnOx, AlNx or SiNx having a refractive index of 1.8-2.5 and the middle layer is formed of SiOx, AlOx or Si.AlOx having a refractive index of 1.4-1.7. The heat insulating glass plates are useful as vehicle window glasses, and the second embodiment of the multilayer coating is very suitable for use in laminated glass.