Polyester film and a production process thereof, and a surface light source, solar battery backsheet and solar battery respectively obtained by using the same

摘要

A polyester film includes a polyester layer (W layer) containing an aromatic polyester resin (A) and a component (B) incompatible with the polyester resin (A), wherein the incompatible component (B) contains an acid-denaturated polyolefin resin (b2) and is dispersed as dispersion pieces with a flatness of 10 or higher in the polyester layer (W layer), and wherein volume occupancy of the dispersion pieces in the polyester layer (W layer) is 3 vol % to less than 50 vol %, and volume occupancy of voids in the polyester layer (W layer) is less than 3 vol %.