| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a white polyester film for protecting a rear surface of a solar cell including, as a hydrolysis resistance improver, a carbodiimide-based compound, the film having excellent hydrolysis resistance, preventing a carbodiimide-based compound from bleeding out, and suppressing degradation in mechanical properties and degradation in adhesion between the film and a filler or an adhesive of the solar cell even in use for a long period of time under severe natural environment such as high temperature and high humidity. <P>SOLUTION: A white polyester film for protecting a rear surface of a solar cell is a biaxially oriented polyester film having a three-layered structure composed of a base material layer (B) and surface layers (A) disposed on both surfaces of the base material layer. The surface layers (A) are made of thermoplastic polyester including no carbodiimide-based compound, and each of the surface layers (A) has a thickness of 3.0 μm or more. The base material layer (B) includes a carbodiimide-based compound and a white pigment, and a content of the carbodiimide-based compound is 0.3 pts.wt. or more and 2.5 pts.wt. or less based on 100 pts.wt. of thermoplastic polyester constituting the base material layer (B). <P>COPYRIGHT: (C)2012,JPO&INPIT |
