Process for the production of a structured film

Patent metadata

Field	Value
Publication number	US-9849629-B2
Application number	US-201414907668-A
Country	US
Kind code	B2
Filing date	Aug 21, 2014
Priority date	Aug 23, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The present invention relates to a process for the formation of a structured film, a structured film as such, an article comprising the structured film, a device for the continuous formation of such a structured film and a composite comprising the structured film.

First claim

The invention claimed is:

1. A process for the formation of a structured porous film comprising:
a) applying a porous film onto an elastic substrate in a stretched state such that a reversible adhesion of the porous film on the stretched substrate occurs,
b) relaxing the substrate with the applied film thereon to obtain a structured porous film, and
c) removing the structured porous film from the substrate.

2. The process according to claim 1 , further comprising applying a backer material to the structured porous film.

3. The process according to claim 1 , wherein the porous film comprises a member selected from fluoropolymer, a polyvinylalcohol, a polyurethane and combinations thereof.

4. The process according to claim 3 , wherein the porous film comprises a member selected from polytetrafluoroethylene (PTFE) a modified PTFE, a fluorothermoplastic, a fluoroelastomer and combinations thereof.

5. The process according to claim 1 , wherein the porous film has a thickness between 0.5 μm and 250 μm.

6. The process according to claim 1 , wherein the substrate comprises a member selected from a polysiloxane, fluorosilicone a rubber and combinations thereof.

7. The process according to claim 1 , wherein the substrate is stretched at a processing ratio of at least 110% in at least one direction.

8. The process according to claim 1 , wherein the elastic substrate is stretched at a processing ratio of at most 1100% in at least one direction.

9. A structured porous film obtained by the process according to claim 1 .

10. The structured film according to claim 9 , wherein structures in the structured film have a height of at least two times the thickness of a non-structured film, and wherein the structure density in at least one direction is at least 1/mm.

11. A structured porous film comprising a porous film reversibly adhered to an elastic substrate, wherein structures in the porous film have a height at least two times the thickness of a non-structured film and the structure density in at least one direction is at least 1/mm.

12. The structured porous film according to claim 11 , wherein the structure density in at least one direction is at least 2/mm.

13. The structured porous film according to claim 12 , wherein the structure height is from 2 μm to 2000 μm.

14. The structured porous film according to claim 13 , wherein the area increase factor of the structured film is at least 1.8.

15. An article comprising a structured porous film according to claim 11 , wherein said elastic substrate is removed.

16. The article according to claim 15 , wherein the article is a vent or a filter.

17. A structured porous film obtained by the process of claim 1 , wherein said structured porous film has applied thereto a backer material to form a composite, and wherein said composite has an asymmetric airflow of at least 30%.

18. A composite comprising a structured film obtained by the process of claim 1 and having an asymmetric airflow of at least 30%.

19. A structured porous film consisting of:
a porous film having structures in the porous film that have a height at least two times the thickness of a non-structured film and the structure density in at least one direction is at least 1/mm,
wherein said porous film has a multi-layered structure.

20. The structured porous film according to claim 19 , wherein the structure density in at least one direction is at least 2/mm.

21. The structured porous film according to claim 20 , wherein the structure height is from 2 μm to 2000 μm.

22. A structured porous film comprising:
a porous film having structures therein that have a height at least two times the thickness of the non-structured film and the structure density in at least one direction is at least 1/mm,
wherein said structures are permanent in said porous film separate from a substrate.

23. The structured porous film according to claim 22 , wherein the structure density in at least one direction is at least 2/m.

24. The structured porous film according to claim 22 , wherein the structure height is from 2 μm to 2000 μm.

25. The structured porous film according to claim 24 , wherein the area increase factor of the structured film is at least 1.8.

26. The structured porous film according to claim 22 , wherein said porous film has a multi-layered structure.

27. The structured porous film according to claim 11 , wherein said porous film has a multi-layered structure.

28. The composite of claim 18 , wherein said composite is in the form of a vent or filter.

Assignees

• Gore W L & Ass Gmbh
• Gore & Ass

Inventors

• Zaggl Alexander
• Heller Bernadette
• Hartmann Andre

Classifications

• B32B2383/00

  Polysiloxanes · CPC title

• B32B27/283

  comprising polysiloxanes · CPC title

• B29C66/727

  being porous, e.g. foam · CPC title

• B29D7/01 Primary

  Films or sheets · CPC title

• B32B27/08

  of synthetic resin · CPC title