| abstract |
The present invention relates to an oriented aromatic polyester film and a method of manufacture thereof. The film is biodegradable, transparent and heat-sealable, and has excellent mechanical properties. The film comprises an acid component that is about 50 to 90 mol % terephthalic acid, about 0.2 to 6 mol % sulfonic acid metal salt, and about 4 to 49.8 mol % aliphatic dicarboxylic acid; and a glycol component that is about 50 to 99.9 mol % ethylene glycol and about 0.1 to 50 mol % diethylene glycol. The film has an impulse seal strength and a high-frequency seal strength of at least 3 N/15 mm. In addition, the film also has low moisture vapor transmission, oxygen transmission and carbon dioxide transmission, and has ultrasonic sealability. |