POLYESTER FILM, BACK SHEET FOR SOLAR CELL MODULE AND MANUFACTURING METHOD OF POLYESTER FILM

摘要

The present invention relates to a polyester film. More specifically, the present invention relates to: the polyester film having excellent hydrolysis properties; a back sheet including the same; and a method for manufacturing the same polyester film. The polyester film includes 30 eq/10^6 g or less of a carboxyl terminal group with respect to weight of polyester, has intrinsic viscosity of 0.62-0.78 dl/g, and includes 1.6% or less of an oligomer. The method for manufacturing the polyester film includes the steps of: a) manufacturing a polyester resin chip by performing a sold-state polymerization reaction on a polyester resin; b) manufacturing an unstretched sheet by melting and extruding the polyester chip of step a); c) manufacturing the film by vertically and horizontally stretching the sheet; and d) thermosetting and releasing the film. According to the present invention, the polyester film having excellent durability and hydrolysis resistance can be provided.