Biaxially oriented polyester film
AssigneeToyobo Co., Ltd.
InventorsMasayuki Haruta, Norimi Tabota
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Abstract
To provide a biaxially oriented polyester film that has extremely low content of antimony, excellent hygiene, few foreign substances, excellent transparency and heat resistance, and is excellent in printability, workability, and productivity. A biaxially oriented polyester film characterized by a content of antimony in the film of 10 ppm or less, a content of phosphorus in the film of 25 ppm or more and 75 ppm or less, an intrinsic viscosity of the film of 0.51 dl/g or more and 0.70 dl/g or less, and a number of defects with a size of 1 mm or more is 1.0 or less per 1000 square meters of the film.
Claims10
A biaxially-oriented polyester film satisfying the following requirements (1) to (7):
- (1) a content of antimony in the film is 10 ppm or less;
- (2) a content of phosphorus in the film is 25 ppm or more and 75 ppm or less;
- (3) an intrinsic viscosity of the film is 0.51 dl/g or more and 0.70 dl/g or less;
- (4) a number of defects with a size of 1 mm or more is 1.0 or less per 1000 square meters of the film;
- (5) the film contains no titanium compounds;
- (6) the film contains no germanium compounds;
- and
- (7) a content of aluminum in the film is 1 to 80 ppm;
- and
- wherein the polyester film is formed with a polyester resin as a polyester raw material containing at least one selected from aluminum compounds and at least one selected from phosphorus compounds as polymerization catalysts.
Dependencies are inferred from the claim text.