| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an oriented polyester film free from optical defects which is not solved by a conventional method and further free from pin holes. <P>SOLUTION: In the oriented polyester film, the existing number of the crater-like optical defects having diameters of ≥0.2 mm is not more than 3 per 10,000 m<SP POS="POST">2</SP>of the film. When an unstretched film is stretched by a tenter method, an oligomer gas concentration in the stretching zone in the tenter is controlled to ≤0.2 mg/m<SP POS="POST">3</SP>. <P>COPYRIGHT: (C)2012,JPO&INPIT |
