PTFE layers and methods of manufacturing

Patent metadata

Field	Value
Publication number	US-11510774-B2
Application number	US-202017115658-A
Country	US
Kind code	B2
Filing date	Dec 8, 2020
Priority date	Apr 13, 2005
Publication date	Nov 29, 2022
Grant date	Nov 29, 2022

Abstract

Thin PTFE layers are described having little or no node and fibril microstructure and methods of manufacturing PTFE layers are disclosed that allow for controllable permeability and porosity of the layers. In some embodiments, the PTFE layers may act as a barrier layer in an endovascular graft or other medical device.

First claim

What is claimed is:

1. A composite film comprising:
a first layer comprising:
a material comprising polytetrafluoroethylene; and
a closed cell microstructure with a plurality of interconnected high-density regions of polytetrafluoroethylene, the closed cell microstructure being substantially free of a node and fibril microstructure between the high-density regions; and

a second layer of expanded polytetrafluoroethylene having a substantial node and fibril microstructure secured to the first layer, the first layer and the second layer defining an inflatable space therebetween.

2. The composite film of claim 1 , wherein the first layer has a thickness from 0.00005 inch to 0.005 inch.

3. The composite of claim 1 , wherein the first layer has substantially no fluid permeability with a Gurley Number of greater than 12 hours for 100 cc of air at a pressure of 12.4 cm of water or a limited fluid permeability with a Gurley Number of greater than 1,500 seconds for 100 cc of air at a pressure of 12.4 cm of water.

4. The composite film of claim 1 , wherein the material comprises a copolymer of polytetrafluoroethylene.

5. The composite film of claim 4 , wherein the copolymer of polytetrafluoroethylene is a fluorinated copolymer of polytetrafluoroethylene.

6. The composite film of claim 4 , wherein the copolymer of polytetrafluoroethylene is perfluoropropylvinylether-modified polytetrafluoroethylene.

7. The composite film of claim 4 , wherein the copolymer of polytetrafluroethylene is about 2% or less of the mass of the material.

8. A tubular structure comprising:
a composite film having a first layer and a second layer,
the first layer comprising:
a material comprising polytetrafluoroethylene; and
a closed cell microstructure with a plurality of interconnected high-density regions of polytetrafluoroethylene, the closed cell microstructure being substantially free of a node and fibril microstructure between the high-density regions, and

the second layer comprising:
a material comprising expanded polytetrafluoroethylene; and
a substantial node and fibril microstructure,

wherein the second layer is secured to the first layer, and an inflatable space is defined by the space therebetween.

9. The structure of claim 8 , wherein the tubular structure is a portion of a vascular graft.

10. The structure of claim 8 , wherein the first layer comprises a thickness from 0.00005 inch to 0.005 inch.

11. The structure of claim 8 , wherein the first layer has a limited or substantially no fluid permeability.

12. The structure of claim 11 , wherein the first layer has a Gurley Number of greater than 12 hours for 100 cc of air at a pressure of 12.4 cm of water.

13. The structure of claim 11 , wherein the first layer has a Gurley Number of greater than 1,500 seconds for 100 cc of air at a pressure of 12.4 cm of water.

14. The structure of claim 8 , wherein the material comprises a copolymer of polytetrafluoroethylene.

15. The structure of claim 14 , wherein the copolymer of polytetrafluoroethylene is a fluorinated copolymer of polytetrafluoroethylene.

16. The structure of claim 14 , wherein the copolymer of polytetrafluoroethylene is perfluoropropylvinylether-modified polytetrafluoroethylene.

17. The structure of claim 14 , wherein the copolymer of polytetrafluoroethylene is about 2% or less of the mass of the material.

18. The structure of claim 14 , wherein the copolymer of polytetrafluoroethylene is perfluoropropylvinylether-modified polytetrafluoroethylene.

Assignees

• Trivascular Inc

Inventors

• Humphrey Joseph W
• Skiba Jeffrey B

Classifications

• A61L27/16

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• B29C48/0011

  combined with compression moulding · CPC title

• B29C48/0018

  combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence) · CPC title

• A61L27/56

  Porous materials, {e.g. foams or sponges} · CPC title

• B29C55/005

  characterised by the choice of materials · CPC title