Biaxially-stretched polyester film and method for producing the same

A method for producing a biaxially-stretched polyester film, the method comprising:

• providing a polyester resin matrix having a refractive index within a range from 1.5 to 1.7;
• providing a plurality of spherical smoothing agents, each of the spherical smoothing agents having a refractive index within a range from 1.3 to 1.9, a particle size within a range from 30 nm to 5 μm, and a circularity greater than or equal to 0.6;
• and
• mixing and then melt-extruding the polyester resin matrix and the spherical smoothing agents, so as to form the biaxially-stretched polyester film through a biaxial stretching process,
• wherein, based on 100 parts by weight of the biaxially-stretched polyester film, a content range of the polyester resin matrix is from 50 to 99.999 parts by weight, and a content range of the spherical smoothing agents is from 0.0001 to 10 parts by weight, and
• wherein, after the biaxial stretching process, the biaxially-stretched polyester film has a haze lower than or equal to 2% and a transparency greater than or equal to 85%.