| 摘要 |
PROBLEM TO BE SOLVED: To provide a laminated white polyester film suitable for use as a light reflector.SOLUTION: A white polyester film includes at least two layers, i.e., a layer A having substantially no pores and a layer B having pores, both composed of polyester, wherein the white polyester film satisfies all of following requirements (1) to (4): (1) the layer B is a film containing a resin immiscible with polyester and inorganic particles and having air bubbles, (2) a content of the resin immiscible with polyester in the layer B is 5 mass% or more and less than 12 mass%, (3) a content of the inorganic particles in the layer B is 15 mass% or more and less than 30 mass%, and (4) a thickness T (μm) and flexural rigidity S (mN×m) of the entire film satisfy expression of 1≤S/T×1,000≤25. |
