POLYVINYL ACETAL FILM HAVING IMPROVED REFLECTANCE AND PREPARATION METHOD THEREOF

摘要

PURPOSE: A polyvinylacetal film is provided to be used as a sealing film for a solar cell module by having excellent light resistance, penetration resistance, and reflectivity. CONSTITUTION: A polyvinylacetal film comprises a polyvinylacetal resin, and a titanium oxide which is heat-resistant coated and has a diameter of 0.4 micrometers or less. The reflectivity of the polyvinylacetal film to a wavelength of 350-1100 nm is 93% or more and the difference of a yellowness index according to EN 410 between before and after UV irradiation(ΔY.I.) is 2.0 or less. A manufacturing method of the polyvinylacetal film comprises: a step of manufacturing a raw material resin by mixing a plasticizer and the heat-resistant coated titanium oxide; and a step of melt-extruding the raw material resin at a temperature of 100-200 deg. C and cooling the extrudate to obtain a final film.