| abstract |
A biaxially oriented polyester film for capacitors, wherein the polyester film comprises a polyester containing 80 mol % or more polyethylene terephthalate units, has at least one coating layer composed of water soluble or water dispersible resin, and has a heat shrinkage stress satisfying the following formulae (1) to (3):wherein S150 and S120 represent the values of heat shrinkage stress per unit cross section area of the film at 150° C. and 120° C., respectively, and Smax represents the maximum value of the heat shrinkage stress at a temperature within the rage of not less than 150° C. and not more than the melting point of the film. |