| abstract |
The present invention relates to a solar cell back encapsulating sheet, which is a solar cell back encapsulating sheet comprising only one piece of polyester film, the polyester film being composed of at least the following A layer and B layer or by layer A and layer B and The polyester film has a whiteness of 50 or more, an average reflectance of 50 to 95% in a wavelength range of 400 to 800 nm, and an acid value of the polyester constituting the polyester film of 1 to 50 eq/ Ton, having a thickness of 150 to 380 μm, has a multilayer structure in which the layer A is disposed as at least one outermost layer, and the thickness of the layer A is 3 to 30% with respect to the thickness of the entire polyester film, as opposed to the entire polyester film. The thickness of the layer B is 20% or more in terms of thickness, and the content of inorganic fine particles in the entire polyester film is 0.5 to 10% by mass. A layer: polyester resin layer B layer having inorganic fine particle content of 10 to 35 mass%: inorganic fine particle content of 0 to 8 mass%, and polyester resin layer having the smallest content of inorganic fine particles in layer A, layer B, and layer C C layer: The polyester resin layer having an inorganic fine particle content of 0.4 to 10% by mass can provide a solar cell module which is excellent in environmental durability, inexpensive, and lightweight by using the solar cell back encapsulating sheet of the present invention. |