abstract |
There is provided a biaxially oriented polyester film comprising a polyester which contains repeating units containing 1,4-cyclohexanedicarboxylic acid and 1,4-cyclohexanedimethanol as main components, and exhibits a melting point of not less than 200° C., wherein the biaxially oriented polyester film has a heat shrinkage percentage of not more than 5% as measured at 130° C. in each of longitudinal and width directions thereof, and a total light transmittance of not less than 90%. The biaxially oriented polyester film of the present invention exhibits an excellent heat resistance notwithstanding the film is composed of an aliphatic polyester, and a good transparency inherent to the aliphatic polyester, and can be suitably used in optical applications. |