| abstract |
This invention pertains to coated polymer sheets which are useful as visibly transparent heat reflective thermal control films and which are suitable for use in glazing applications. The coated polymer sheets are characterized by a high transmission of visible radiation (i.e., visibly transparent) and a high reflectance at one or more near infrared radiation center wavelengths (i.e., heat reflective), and rely primarily on the interference effects of the dielectric layers to achieve these results. More specifically, the present invention pertains to thermal control films comprising (a) a thin flexible polymeric sheet having a first face and an opposite second face and a thickness of from 0.1 to 100 mils; and, (b) a multilayer coating adhered to said first face, said coating comprising two or more contiguous alternating layers of high and low index of refraction inorganic dielectric material of optical thickness approximately equal to one quarter of an infrared center wavelength, lambd0, between 750 and 2000 nm; said thermal control film characterized by an average transmittance of visible radiation of wavelength 380 to 750 nm at 0° incidence of at least 50%; said thermal control film further characterized an average reflectance of infrared radiation in an infrared radiation band which is at least 100 nm wide and falls within the wavelength band 750 to 2000 nm, at 0° incidence, of at least 50%. |