| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyester film which is excellent in moldability, heat resistance, flavor characteristics, and food hygiene and is suitable for high- impact metal cans prepd. by molding by blending two specific polyesters. SOLUTION: A polyester A in an amount of 1-30 pts.wt. formed by copolymerizing a dimerized fatty acid having an unsatd. bond or an ester- forming deriv. thereof and 70-99 pts.wt. polyester B of which at least 80 wt.% of the structural units are ethylene terephthalate units are blended. Polyester A of which 60-99 wt.% of the structural units are butylene terephthalate units is pref. in terms of impact strength, and polyester A which is prepd. by using a titanium compd. as a catalyst and contains 100-300 ppm titanium (based on the polymer) is pref. Polyester B of which 1-20 wt.% of the structural units are ethylene isophthalate units is pref. in terms of moldability and compatibility with polyester A. |
