POLYESTER FILM FOR PROTECTION OF BACK SURFACES OF SOLAR CELLS

摘要

It is an object of the present invention to provide a polyester film for the protection of a back surface of a solar cell which, when applied to a silicon thin film solar cell, exhibits excellent durability even under high-temperature and high-humidity conditions and long term thermal stability. A polyester film for the protection of a back surface of a solar cell containing a polyester, as a main constituent, obtained by polymerization using a polycondensation catalyst containing aluminum and/or its compound as well as a phosphorus compound having an aromatic group in the molecule; having a whiteness degree of 50 or higher; containing 3 to 50% by mass of fine particles with a mean particle diameter of 0.1 to 3 µm; and having an acid value from not lower than 1 (eq/ton) and not higher than 30 (eq/ton).