Patent ID: 11345631

Abstract:
Provided is a functional building material for a door and a window, comprising a transparent substrate and a low-emissivity coating formed on one surface of the transparent substrate, wherein the low-emissivity coating comprises a first dielectric layer, a second dielectric layer, a third dielectric layer, a first low-emissivity protection layer, a low-emissivity layer, a second low-emissivity protection layer, a fourth dielectric layer, a fifth dielectric layer and a sixth dielectric layer which are stacked sequentially from the transparent substrate, wherein the refractive index of the first dielectric layer and the refractive index of the third dielectric layer are each lower than the refractive index of the second dielectric layer, and the refractive index of the fourth dielectric layer and the refractive index of the sixth dielectric layer are each lower than the refractive index of the fifth dielectric layer.