Biaxially oriented polyester film
AssigneeToray Industries, Inc.
InventorsHideaki Maeba, Masato Horie, Tatsuo Yoshida
Life of this patent
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Abstract
A polyester film constituted of a polyester resin which has an intrinsic viscosity (IV value) of 0.640-0.700, wherein the polyester resin constituting the polyester film contains a P element and further contains at least one element selected from among Mn, Mg, Ca, K, and Na elements, and when the content of the P element in the whole polyester resin is expressed by P (mol/t) and the total content of the Mn, Mg, Ca, K, and Na elements is expressed by M (mol/t), then the following relationships (1) and (2) are satisfied: 1.00≤M−P≤2.50 (1) 1.60≤M/P≤4.00 (2) A polyester film satisfactory in terms of local heat resistance, printing sensitivity, processability, and manufacturability is provided.
Claims8
A polyester film, comprising a polyester resin having an intrinsic viscosity (IV value) of 0.640 to 0.700, wherein the polyester resin that constitutes the polyester film contains a P element and also contains at least one element of a Mn element, a Mg element, a Ca element, a K element, and a Na element, and a content P (mol/t) of the P element and a total M (mol/t) of contents of the Mn element, the Mg element, the Ca element, the K element, and the Na element in all the polyester resin satisfy the following expressions (1) and (2):
- 1.00≤M−P≤2.50 (1);
- and
- 1.60≤M/P≤4.00 (2),
- and wherein the thickness of the polyester film is 1.5 to 6.0 μm.
Dependencies are inferred from the claim text.