Method for producing porous articles from alternating poly(ethylene tetrafluoroethylene) and articles produced therefrom

Patent metadata

Field	Value
Publication number	US-9932429-B2
Application number	US-201514811510-A
Country	US
Kind code	B2
Filing date	Jul 28, 2015
Priority date	Jul 29, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

Poly(ethylene tetrafluoroethylene) (ETFE) polymers having an average molecular weight of at least 300,000 g/mol and a melt enthalpy of at least 57 J/g are provided. The ETFE polymer may include at least one additional comonomer. The ETFE polymer is used to form a porous tape or membrane that has a node and fibril structure. A porous ETFE tape may be formed by lubricating the ETFE polymer and subjecting the lubricated polymer to pressure at a temperature below the melting point of the ETFE polymer. Optionally, the ETFE tape may be expanded at a temperature below the melting temperature of the ETFE polymer to form an expanded ETFE membrane. Alternatively, the ETFE polymer may subjected to heat and pressure without the addition of a lubricant to form a dense preform. The dense preform may be subsequently slit in a length direction and stretched to form a dense ETFE fiber.

First claim

What is claimed is:

1. A microporous poly(ethylene tetrafluoroethylene) (ETFE) article comprising:
a microporous ETFE tape formed from an ETFE polymer having an average molecular weight of at least about 300,000 g/mol, a melting point from about 260° C. to 300° C., and a melt enthalpy of at least 57 J/g, said tape having a node and fibril structure.

2. The microporous article of claim 1 , wherein, said ETFE polymer includes from about 0.001 mol % to about 10 mol % of an additional monomer.

3. The microporous article of claim 1 , wherein said ETFE tape has a thickness from about 0.01 to about 4 mm.

4. The microporous article of claim 1 , wherein said ETFE tape has a porosity greater than about 10%.

5. The microporous article of claim 1 , wherein said ETFE polymer has an average molecular weight from about 500,000 g/mol and about 20,000,000 g/mol.

6. A microporous polyethylene tetrafluoroethylene) (ETFE) article comprising:
a microporous ETFE membrane formed from an ETFE polymer having an, average molecular weight of at least about 300,000 g/mol, a melting point from about 260° C. to 300° C., and a melt enthalpy of at least 57 J/g, said ETFE membrane having a node and fibril structure.

7. The microporous article of claim 6 , wherein said ETFE polymer includes from about 0,001 mol % to about 10 mol % of an additional comonomer.

8. The microporous article of claim 6 , wherein said ETFE membrane has a thickness less than about 1 mm.

9. The microporous article of claim 6 , wherein said ETFE membrane has a thickness from about 0.08 mm to about 0.5 mm.

10. The microporous article of claim 6 , wherein said FIFE membrane has a porosity greater than about 10%.

11. The microporous article of claim 6 , wherein said ETFE polymer has an average molecular weight from about 500,000 g/mol to about 20,000,000 g/mol.

12. The microporous article of claim 6 , wherein said article is selected from a sheet, membrane, fiber, tube and three dimensional self-supporting structure.

Assignees

• Gore & Ass

Inventors

• Sbriglia Guy A

Classifications

• B29C48/04

  Particle-shaped (making granules B29B9/00) · CPC title

• C08F214/26

  Tetrafluoroethene · CPC title

• B29K2027/12

  containing fluorine · CPC title

• B29C48/022 Primary

  characterised by the choice of material · CPC title

• B29K2995/0041

  Crystalline · CPC title