Air-permeable sheet filter material, methods for the production and use thereof

Patent metadata

Field	Value
Publication number	US-11607668-B2
Application number	US-201816767272-A
Country	US
Kind code	B2
Filing date	Sep 3, 2018
Priority date	Nov 28, 2017
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

The present invention relates to a sheet filter material, in particular having an aerosol filter function and/or a particle filter function, preferably having a protective function against chemical, biological and/or chemical harmful and toxic substances, and to a method for the production thereof. The sheet filter material is particularly suitable for producing protective equipment, protective objects, sports and leisure clothing and filters and filter materials of all types.

First claim

The invention claimed is:

1. A sheet filter material having an aerosol and particle filter function and further providing a protective function in relation to chemical, biological and radioactive harmful and toxic substances, wherein the sheet filter material comprises: (a) an air-permeable and water-vapor-permeable, planar foam-based support material having two opposite flat sides, wherein the support material is an air-permeable and discontinuously configured layer based on a dried and cured, cross-linked broken polymer foam structure, wherein the broken polymer foam structure is configured so as to be open-pored; (b) an air-permeable and water-vapor-permeable, planar nanofiber layer which is fixed to a first flat side of the foam-based support material, wherein the nanofiber layer comprises a multiplicity of nanofibers; and (c) at least one adsorption layer, wherein the adsorption layer comprises a multiplicity of individual and discrete adsorber particles and wherein the adsorption layer has two opposite flat sides, wherein the adsorption layer is disposed on the second flat side of the support material that faces away from the nanofiber layer.

2. The sheet filter material as claimed in claim 1 ,
wherein the support material has an area weight in the range from 5 g/m 2 to 500 g/m 2 ,
wherein the support material has a thickness in the range from 0.01 mm to 10 mm, and
wherein the support material has a density in the range of from 25 g/l to 250 g/l.

3. The sheet filter material as claimed in claim 1 ,
wherein the broken polymer foam structure comprises a multiplicity of dried or cured, cross-linked, destroyed or burst or collapsed foam bubbles.

4. The sheet filter material as claimed in claim 1 ,
wherein the broken polymer foam structure comprises a multiplicity of destroyed, broken or collapsed walls or webs formed from a polymer foam structure material; and
wherein the broken polymer foam structure comprises a proportion of destroyed, burst or collapsed foam bubbles in the range of from 10% up to 95%, in terms of the overall number of foam bubbles in the broken polymer foam structure.

5. The sheet filter material as claimed in claim 1 ,
wherein the broken polymer foam structure comprises a multiplicity of breakthroughs, pores, ducts or openings extending within the broken polymer foam structure and connecting the two flat sides of the support material.

6. The sheet filter material as claimed in claim 1 ,
wherein the broken polymer foam structure is configured so as to be contiguous and coherent.

7. The sheet filter material as claimed in claim 1 ,
wherein the nanofiber layer has two opposite flat sides.

8. The sheet filter material as claimed in claim 1 ,
wherein the nanofiber layer is fixed to the first flat side of the support material at least substantially across the entire area of a first flat side of the nanofiber layer.

9. The sheet filter material as claimed in claim 1 ,
wherein the nanofiber layer is fixed to the first flat side of the support material without the use of a bonding agent.

10. The sheet filter material as claimed in claim 1 ,
wherein the nanofiber layer is configured as a planar or three-dimensional textile formation comprising the nanofibers.

11. The sheet filter material as claimed in claim 1 ,
wherein the nanofibers are disposed randomly and in a non-oriented manner in the nanofiber layer; and
wherein the nanofibers are bonded to one another, within the nanofiber layer, by means of an inherent adhesiveness of the nanofibers.

12. The sheet filter material as claimed in claim 1 ,
wherein the nanofiber layer is configured as a cross-laid fabric or a textile composite cloth; and
wherein the nanofiber layer has a thickness in the range of from 0.001 μm to 100 μm.

13. The sheet filter material as claimed in claim 1 ,
wherein the nanofibers have mean fiber diameter D 50 in the range of from 2 nm to 4,500 nm; and
wherein the nanofiber layer has openings or pores which are delimited by the nanofibers, wherein the nanofiber layer has a mean openings or pore size of at most 150 μm.

14. The sheet filter material as claimed in claim 1 ,
wherein the nanofibers have a mean fiber diameter D 50 in the range of from 2 nm to 4,500 nm; and
wherein the nanofiber layer has openings or pores which are delimited by the nanofibers, wherein the ratio of the mean opening or pore size to the mean fiber diameter D 50 of the nanofibers, on the other hand, is in the range from 0.2 to 1,800.

15. The sheet filter material as claimed in claim 1 ,
wherein the sheet filter material furthermore comprises at least one textile carrier.

16. The sheet filter material as claimed in claim 15 ,
wherein the textile carrier is fixed to the support material and
wherein the textile carrier is configured as an air-permeable and water-vapor-permeable textile material.

17. The sheet filter material as claimed in claim 1 ,
wherein the sheet filter material furthermore comprises at least one covering layer.

18. The sheet filter material as claimed in claim 17 ,
wherein the covering layer is configured as an air-permeable and water-vapor-permeable textile material.

19. The sheet filter material as claimed in claim 1 ,
wherein the sheet filter material is configured as a self-supporting composite material,
wherein the sheet filter material has an overall area weight in the range of from 10 g/m 2 to 800 g/m 2 ;
wherein the sheet filter material has an air permeability of at least 10 l·m −2 ·s −1 at a flow resistance of 127 Pa;
wherein the sheet filter material at 25° C. has a water-vapor permeability of at least 10 l/m 2 per 24 h; and
wherein the sheet filter material has a water-vapor transmittance resistance R et at stationary conditions, measured according to DIN EN 31 092:1993 (February 1994) and international standard ISO 11 092, at 35° C., of at most 25 (m 2 ·Pascal)/Watt.

20. The sheet filter material as claimed in claim 1 ,
wherein the sheet filter material has an overall thickness in the range of from 0.1 mm to 30 mm.

21. A method for producing a sheet filter material as defined in claim 1 ,
wherein the method comprises the following steps:
providing an air-permeable and water-vapor-permeable planar foam-based support material having two opposite flat sides, wherein the support material is an air-permeable and discontinuously configured layer based on a dried and cured, cross-linked broken polymer foam structure, wherein the broken polymer foam structure is configured so as to be open-pored and/or not to be closed;
applying an air-permeable and water-vapor-permeable, planar nanofiber layer comprising a multiplicity of nanofibers on a first flat side of the foam-based support material in such a manner that the nanofiber layer is fixed to the first flat side of the support material;

wherein the sheet filter material is furthermore provided with at least one adsorption layer comprising a multiplicity of individual and discrete adsorber particles, wherein the adsorption layer has two opposite flat sides, wherein the adsorption layer is disposed on the second side of the support material that faces away from the nanofiber layer.

22. A protective equipment comprising a sheet filter material as defined in claim 1 .

23. The protective equipment as claimed in claim 22 ,
wherein the protective equipment is selected from the group consisting of protective items for the civil or defense sector, protective clot

Assignees

• Bluecher Gmbh

Inventors

• Böhringer Bertram
• Fischer Rainer
• Nguyen Congminh

Classifications

• B01D2239/045

  Deodorising additives · CPC title

• B32B5/022

  Non-woven fabric · CPC title

• B01D2239/1216

  Pore size · CPC title

• B01J20/103

  comprising silica · CPC title

• B01D2239/10

  Filtering material manufacturing · CPC title