Polyester film and laminate using same

Patent metadata

Field	Value
Publication number	US-9492987-B2
Application number	US-201113997460-A
Country	US
Kind code	B2
Filing date	Dec 15, 2011
Priority date	Dec 24, 2010
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

A polyester film suitable for use in battery packages, particularly for use in deep drawn packages of lithium ion secondary batteries that includes an electrolyte (in a solid state or in a liquid state), and which is also suitable for use in packages of pharmaceutical products that have various shapes. The polyester film is characterized in that the stresses at 5% elongation (F5 values) and the stresses at 10% elongation (F10 values) of the film in the longitudinal direction and in the transverse direction at 25° C., respectively, satisfy (I) and (II):

1.5≧ F 10 MD /F 5 MD ≧1  (I)

1.5≧ F 10 TD /F 5 TD ≧1  (II).

First claim

The invention claimed is:

1. A polyester film having a stress at 5% elongation (F5 value) and a stress at 10% elongation (F10 value) at 25° C. in a longitudinal direction (MD) and those in a transverse direction (TD) that satisfy formulae (I), (II), (III) and (IV):
1.5≧ F 10 MD /F 5 MD ≧1  (I)

1.5≧ F 10 TD /F 5 TD ≧1  (II)

F 10 MD ≧120 MPa  (III)

F 10 TD ≧120 MPa  (IV),

wherein in the polyester film 95 mol % or more of glycol units are structural units derived from ethylene glycol and 95 mol % or more of dicarboxylic acid units are structural units derived from terephthalic acid.

2. The polyester film as defined in claim 1 , wherein the stress at 10% elongation at 25° C. in the longitudinal direction and that in the transverse direction satisfy formula (V):
1.2≧ F 10 MD /F 10 TD ≧0.8  (V).

3. The polyester film as defined in claim 1 , wherein the polyester film has a degree of heat shrinkage at 200° C. is −5 to 5% both in the longitudinal and transverse directions.

4. The polyester film as defined in claim 1 , wherein at least either of its surfaces has a dynamic friction coefficient μd of 0.3 to 0.8.

5. A laminate comprising the polyester film as defined in claim 1 laminated to a metal foil.

6. Packaging for batteries comprising the polyester film as defined in claim 1 .

7. Medical packaging containers comprising polyester film as defined in claim 1 .

8. Laminates comprising polyester film as defined in claim 1 , wherein at least either of surfaces is laminated with aluminum foil with a thickness of 10 μm or more and 60 μm or less.

9. Packaging for batteries comprising laminates as defined in claim 8 .

10. The polyester film as defined in claim 2 , wherein the polyester film has a degree of heat shrinkage at 200° C. is −5 to 5% both in the longitudinal and transverse directions.

11. The polyester film as defined in claim 2 , wherein at least either of its surfaces has a dynamic friction coefficient μd of 0.3 to 0.8.

12. A polyester film having a stress at 5% elongation (F5 value) and a stress at 10% elongation (F10 value) at 25° C. in a longitudinal direction (MD) and those in a transverse direction (TD) that satisfy formulae (I), (II), (III) and (IV):
1.5≧ F 10 MD /F 5 MD ≧1  (I)

1.5≧ F 10 TD /F 5 TD ≧1  (II)

F 10 MD ≧120 MPa  (III)

F 10 TD ≧120 MPa  (IV).

13. A polyester film having a stress at 5% elongation (F5 value) and a stress at 10% elongation (F10 value) at 25° C. in a longitudinal direction (MD) and those in a transverse direction (TD) that satisfy formulae (I) and (II):
1.5≧ F 10 MD /F 5 MD ≧1  (I)

1.5≧ F 10 TD /F 5 TD ≧1  (II),

wherein the polyester film has a degree of heat shrinkage at 200° C. is −5 to 5% both in the longitudinal and transverse directions.

14. A polyester film having a stress at 5% elongation (F5 value) and a stress at 10% elongation (F10 value) at 25° C. in a longitudinal direction (MD) and those in a transverse direction (TD) that satisfy formulae (I) and (II) given below:
1.5≧ F 10 MD /F 5 MD ≧1  (I)

1.5≧ F 10 TD /F 5 TD ≧1  (II)

wherein in the polyester film 95 mol % or more of glycol units are structural units derived from ethylene glycol and 95 mol % or more of dicarboxylic acid units are structural units derived from terephthalic acid.

Assignees

• Manabe Isao
• Tanaka Teruya
• Takahashi Kozo
• Toray Industries

Inventors

• Manabe Isao
• Tanaka Teruya
• Takahashi Kozo

Classifications

• H01M50/131

  characterised by physical properties, e.g. gas permeability, size or heat resistance · CPC title

• H01M50/136

  Flexibility or foldability · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M50/124

  having a layered structure · CPC title

• H01M50/133

  Thickness · CPC title