Structured dense fluoropolymer films and methods of making same

Patent metadata

Field	Value
Publication number	US-12031001-B2
Application number	US-201817277776-A
Country	US
Kind code	B2
Filing date	Oct 5, 2018
Priority date	Oct 5, 2018
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

A structured fluoropolymer film including a plurality of structures having a height at least two times a thickness of a corresponding unstructured fluoropolymer film and at least a 20% increase in displacement induction period when compared to the corresponding unstructured fluoropolymer film when measured in a biaxial tensile curve at a temperature of about 125° C. In addition, the structured fluoropolymer film has a methane permeability of less than 500 μg*μm/cm 2 /min. The structured fluoropolymer film exhibits a higher resistance to strain and retain barrier properties during manufacture and/or use.

First claim

What is claimed is:

1. A structured fluoropolymer film comprising:
a dense fluoropolymer film including a plurality of structures having a height at least two times a thickness of a corresponding unstructured fluoropolymer film, wherein the thickness of the corresponding unstructured fluoropolymer film is from about 1 μm to about 50 μm, and wherein the height of the plurality of structures is from 2 μm to 500 μm; and
at least a 20% increase in a displacement induction period when compared to the corresponding unstructured dense fluoropolymer film when measured in a biaxial tensile curve at a temperature of about 125° C.,
wherein the dense fluoropolymer film has a water vapor permeability coefficient of 0.015 g-mm/m 2 /day or less, and a matrix tensile strength of at least 69 MPa in both the x and y directions,
wherein the dense fluoropolymer film has a thickness from 0.5 microns to 250 microns,
wherein the structured fluoropolymer film has at least a 5% increase in mass per unit area when compared to the corresponding unstructured fluoropolymer film, and

wherein the structured fluoropolymer film has a methane permeability of less than 500 μg*μm/cm 2 /min.

2. The film of claim 1 , wherein the structured fluoropolymer film has a structural density in at least one direction of at least 1/mm.

3. The film of claim 1 , wherein the structured fluoropolymer film has a void volume of less than 20%.

4. The film of claim 1 , wherein the structured fluoropolymer film has a matrix tensile strength that is greater than or equal to about 7.0 MPa in at least one direction.

5. The film of claim 1 , wherein the increase in the displacement induction period when compared to the corresponding unstructured fluoropolymer film is at least about 100%.

6. The film of claim 1 , wherein the structured fluoropolymer film comprises polytetrafluoroethylene (PTFE).

7. The film of claim 6 , wherein the PTFE is a PTFE homopolymer, a modified PTFE, a tetrafluoroethylene (TFE) copolymer, or any combination thereof.

8. A composite comprising the structured fluoropolymer film of claim 1 .

9. The composite of claim 8 , further comprising at least one thermoplastic selected from the group consisting of fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), perfluoro (alkyl vinyl) ethers (PAVE), perfluoroelastomeric materials, a polymer of tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride (THV), perfluoroalkoxy alkane (PFA), a copolymer of ethylene and tetrafluoroethylene (ETFE) and polychlorotrifluoroethylene (PCTFE).

10. A laminate comprising the structured fluoropolymer film of claim 1 .

Assignees

• Gore & Ass

Inventors

• Kennedy Michael E
• Ran Shaofeng

Classifications

• C08L27/18

  Homopolymers or copolymers or tetrafluoroethene · CPC title

• C08J2327/18

  Homopolymers or copolymers of tetrafluoroethylene · CPC title

• B32B2307/7246

  Water vapor barrier · CPC title

• B32B2307/518

  bi-axially · CPC title

• B32B38/0012

  Mechanical treatment, e.g. roughening, deforming, stretching · CPC title