| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film for protecting a back surface of a solar battery, in which hydrolysis resistance and static electricity application and adhesion property are both improved even when a reactive terminal-blocking agent is compounded.SOLUTION: (A) The polyester film for protecting a back surface of a solar battery comprises a polyester resin polymerized by using an aluminum compound and a P compound having an aromatic group in the molecule, as a catalyst, and satisfies the following requirements (B) to (D) and (1) and (2). (B) The polyester film contains at least one of an alkali metal compound and an alkaline earth metal compound, in which the total of contents of the alkali metal compound and the alkaline earth metal compound is over 10 ppm and 60 ppm or less. (C) The polyester resin is produced by melting and polymerizing after a heterocyclic compound having a pKa of over 7 and including a nitrogen atom is added by 0.5 to 3.0 mol/ton to the resin. (D) The film is produced by extruding a polyester resin composition prepared by adding a reactive terminal-blocking agent to the above polyester. The polyester film has such properties that: (1) (film AV value)≤10 eq/ton; and (2) (resistivity of a molten film at 275°C)≤1.5×10&OHgr; cm. |
