| 摘要 |
<p>A porous polyester film comprising a composition comprising a polyester resin and a thermoplastic resin incompatible with the polyester resin, and a number of voids formed by dispersing the incompatible thermoplastic resin to provide particles in the polyester resin and stretching same, wherein the incompatible thermoplastic resin comprises a polyolefin resin, and the film satisfies the following requirements (a) to (c): (a) an apparent specific gravity of not more than 1.3; (b) an average size d of dispersed particles of the polyolefin resin of not more than 15 mu m; and (c) a ring crush strength G (unit:kg/mm) and a film thickness t (unit:mm) satisfying the following formula <MATH> is provided. According to the invention, a film having superior properties derived from a porous structure (e.g., cushioning property, low dielectric property, light weight) and good handling property.</p> |
