Biaxially-oriented polyester film for fabrication and method of producing the same

• US 6,905,774 B2
• Filed: 08/27/2003
• Issued: 06/14/2005
• Est. Priority Date: 12/03/1999
• Status: Expired due to Term

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Takahashi, Kohzo, Kimura, Masahiro, Matsui, Ryosuke
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US10/648,320
• Publication Number:
  US 20040219316A1
• Time in Patent Office: 657 Days
• Field of Search: 428/458, 428/35.7, 428/35.8, 428/35.9, 428/457, 428/480, 428/910, 428/331, 428/446, 428/447, 428/450, 528/275, 528/283, 528/302, 528/305, 528/308, 528/308.1, 528/308.3, 528/308.6, 528/308.8, 524/275, 524/277, 524/261, 525/165, 525/437, 525/446
• US Class Current: 428/458
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 15/09 comprising polyesters
• CPC Class Codes: B32B 2307/306 Resistant to heat
• CPC Class Codes: B32B 2307/518 bi-axially
• CPC Class Codes: B32B 2307/73 Hydrophobic
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2439/66 Cans, tins
• CPC Class Codes: B32B 2439/70 Food packaging
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B65D 25/14 Linings or internal coatings of containers made by folding or erecting blanks made of paper B65D5/56 ; linings for domestic water storage heaters F24H1/183
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1355 Elemental metal containing [e.g., substrate, foil, film, coating, etc.]
• CPC Class Codes: Y10T 428/1359 Three or more layers [continuous layer]
• CPC Class Codes: Y10T 428/259 Silicic material
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 428/31681 : Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]

Abstract

Biaxially-drawn polyester film for fabrication which is characterized in that it is a film comprising polyester in which ethylene terephthalate units and/or ethylene naphthalate units are the chief structural component, and the melting point of said film is 180-270° C., the angle of contact to water is 70°-120°, and the planar orientation coefficient is 0.08-0.15. This film shows outstanding release properties following repeated use, use after fabrication and use in an aqueous environment and, furthermore, it exhibits stable properties with little variation and, in particular, following lamination to metal sheet such as steel or aluminium, when used as the inner face of a fabricated metal can, it is outstanding in its non-stick properties to the contents, and provides a combination of heat resistance and processability.

Claims

1. Biaxially-oriented polyester film for fabrication which is characterized in that it is a film comprising polyester in which ethylene terephthalate units and/or ethylene naphthalate units are the chief structural component and containing 0.001-5 wt % of a wax compound and/or silicone compound, and the melting point of said film is 180-270°

C., the angle of contact to water is 70°

-120°

, and the planar orientation coefficient is 0.08-0.15.

2. Biaxially-oriented polyester film for fabrication according to claim 1 where the surface free energy is 20-40 mN/m.

3. Biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that 0.2-5 wt % of inorganic particles and/or organic particles are included in the film.

4. Biaxially-oriented polyester film for fabrication according to claim 1 in which there is contained 1 to 200 ppm of germanium element.

5. Biaxially-oriented polyester film for fabrication which is characterized in that it is a laminate film comprising a structure of at least two layers, and at least one face is polyester film according to claim 1.

6. Biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that it is used in food packaging applications.

7. Biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that it is used by lamination to sheet metal.

8. A method of producing the biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that the production is carried out by dilution of a master batch containing 1-200 ppm of germanium element and 1-10 wt % of carnauba wax.

9. Biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that the average lengthwise and widthwise breaking elongation at 100°

C. is 200 to 500%.

10. Biaxially-oriented polyester film for fabrication according to claim 1 which is characterized in that the absolute value of the difference between the lengthwise breaking elongation and the widthwise breaking elongation at 100°

C. is no more than 50%.

11. Biaxially-oriented polyester film for fabrication according to claim 1 where the melting point of the film is 246-265°

C.