| 摘要 |
A biaxially oriented polyester film for solar cells which is made of a composition of a polyethylene terephthalate prepared by using an antimony compound and/or a titanium compound as a polycondensation catalyst(s), wherein
the composition contains 10 to 80 mmol% of a phosphorus atom derived from specific phosphonic acid or specific phosphinic acid and 2 to 60 mmol% of the total of an antimony atom and/or a titanium atom as metal atoms based on the number of moles of all dicarboxylic acid components constituting the polyethylene terephthalate, the biaxially oriented polyester film has a plane orientation coefficient "fn" of 0.160 to 0.175, and the polyester of the film has an intrinsic viscosity number of 0.56 to 0.74 dl/g and a terminal carboxyl group concentration of 6 to 29 equivalents/ton. |
