| 摘要 |
<p>A biaxially oriented polyester film, comprising a polyester (A) at least mainly composed of ethylene terephthalate and a polyether imide (B), having a single glass transition temperature, and having a refractive index of 1.60 to 1.80 at least in either the machine direction or the transverse direction, has excellent thermal dimensional stability, clarity and is easy to produce. It can be prepared by melt-extruding a polyester (A) at least mainly composed of ethylene terephthalate and polyether imide (B), to mold a resin sheet with a single glass transition temperature, and stretching the resin sheet at a ratio of 3.0 to 10 times in the machine direction and at a ratio of 3.0 to 10 times in the transverse direction.</p> |
