To provide a biaxially oriented polyester film which has a practical antistatic property at ordinary temperature and which, in addition, little causes the deterioration of the antistatic property by the heat applied upon the post-processing.

The antistatic polyester film is a film obtained by coating at least one surface with a coating liquid containing a polymer having a pyrrolidinium ring in the main chain and then carrying out orientation and heat setting. The surface resistivity of its coated surface is ≤1×1011Ω, and the increasing rate of the surface resistivity of the coated surface after the heat treatment of the film in the air at 250°C for one minute is ≤50 times.

COPYRIGHT: (C)2008,JPO&INPIT