POLYESTER FILM AND METHOD FOR PRODUCING SAME, BACKSHEET FOR SOLAR CELL, AND SOLAR CELL MODULE

摘要

PURPOSE: A polyester film, a producing method thereof, a back sheet for a solar battery, and a solar battery module are provided to offer the excellent weather ability and the low thermal shrinkage of the film. CONSTITUTION: A producing method of a polyester film comprises the following steps: dissolve-extruding a polyester resin having the inherent viscosity of 0.74-0.91dL/g for forming the polyester film; extending the polyester film; and thermal-fixing the extended polyester film by applying the localized temperature variation at 0.1-10deg C or the localized wind speed variation of 0.1-10% to the film width direction.