POLYESTER FILM FOR SOLAR BATTERY BACK SHEET, AND METHOD FOR MANUFACTURING POLYESTER FILM ROLL FOR SOLAR BATTERY BACK SHEET, WHICH IS FORMED BY WINDING UP POLYESTER FILM FOR SOLAR BATTERY BACK SHEET

摘要

PROBLEM TO BE SOLVED: To provide a polyester film for a solar battery back sheet, which can increase the power generation efficiency and which is superior in productivity and low cost effectiveness because of its high diffusion and high reflectance, and a solar battery.SOLUTION: A polyester film used for a solar battery back sheet 2 satisfies the requirements (1) to (4) below. (1)In a section of the film, the content of voids is 4% or more and 40% or less. (2)The film includes a polyester resin composition which contains inorganic particles of which the content is 0.5 wt.% or more and 20 wt.% or less to a total weight of the polyester composition. (3)The Rz (maximum roughness) of at least one surface is 2 μm or less. (4)The polyester film is a laminate polyester film including three layers composed of surface layers 7, 9 as layers each having a film surface and a base layer 8 having no film surface.SELECTED DRAWING: Figure 2