LAMINATED POLYESTER FILM FOR PROTECTION OF SOLAR CELL UNDERSIDES

摘要

Provided is a laminated polyester film for protecting solar cell undersides, said film having excellent weather resistance and hydrolysis resistance and being capable of maintaining strength over a long period of time. The laminated polyester film comprises a surface layer (A) and a base layer (B). The surface layer (A) is a polyester composite comprising, by weight, 10-30% rutile titanium oxide particles and 70-90% polyester. The base layer (B) is a polyester composite comprising, by weight, 0.1-4% rutile titanium oxide particles and 96-99.9% polyester. The thickness of the base layer (B) is 70-97% of the total thickness of the film. The weight-average molecular weight of the polyester in the laminated film is between 47,000 and 65,000, and the COOH end group concentration is between 6 and 25 eq/ton. The mean weight content of rutile titanium oxide particles in all layers of the laminated film is between 3 and 8%.