BIAXIALLY ORIENTED WHITE POLYETHYLENE TEREPHTHALATE FILM AND BACK PROTECTIVE FILM FOR USE IN SOLAR CELL MODULES

摘要

Disclosed is a low-cost biaxially oriented white polyethylene terephthalate film with excellent environmental resistance (hydrolysis resistance and UV resistance) and suitable in fields that demand reflection efficiency and light weight; also disclosed is a back protective film for use in solar cell modules. The biaxially oriented white polyethylene terephthalate film has a phosphorus content of 70 ppm by weight or less, 26 equivalent/ton or fewer terminal carboxyl groups, an intrinsic viscosity of 0.65 dl/g or more, a concentration of white pigment content of 2.0-10.0 weight%, and a thickness of 175 µm or greater.