Double-layer polyester film and preparation method thereof

The invention relates to the technical field of thermal-insulation films and particularly relates to a double-layer polyester film and a preparation method thereof. By forming a self-cleaning auxiliary wear-resistant layer on the upper surface of a first substrate layer, the wear resistance of the film is ensured, the film has hydrophobic, oleophobic, anti-frost, anti-fog, pollution-resistant, antibacterial and self-cleaning functions and the transmittance of the film can also be increased; the self-cleaning auxiliary wear-resistant layer is prepared by curing specific component in a specific proportion, the double-layer polyester film is strong in self-cleaning capability, and the contact angle is 140 degrees-158 degrees. A UV-resistant and infrared-resistant thermal-insulation layer is formed between the first substrate layer and the second substrate layer, is prepared by curing specific component in a specific proportion and can well shield ultraviolet and 800-2500nm infrared light; hollow glass microspheres are added so that the thickness of the coating can be precisely controlled and since the hollow glass microspheres have the characteristics of being hollow, light in weight and low in thermal conductivity, the purposes that the heat transfer coefficient is reduced and the thermal-insulation performance of the film is enhanced are achieved.