摘要 |
A heat insulating film comprises a plastic film, a surface metal layer coating the plastic film, a thin metal layer coating the surface metal layer and a protective membrane layer coating the thin metal layer. The surface metal layer has crystal grains having flat upper surfaces and the thin metal layer has flat crystal grains disposed in a single grain layer and formed and overlying respective flat upper surfaces of the crystal grains of the surface metal layer. Heat rays which irradiate on the heat insulating film pass freely through the protective membrane layer but are reflected by the crystal grains of the thin metal layer. Absorption of heat rays by the heat insulating film is remarkably suppressed. |