Particle-loaded nonwoven fibrous article for separations and purifications

• US 5,328,758 A
• Filed: 08/14/1992
• Issued: 07/12/1994
• Est. Priority Date: 10/11/1991
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Markell, Craig G., Hansen, Paul E., Baumann, Nicholas R., Hagen, Donald F.
• Primary Examiner(s): Bell, James J.
• Application Number:
  US07/929,985
• Time in Patent Office: 697 Days
• Field of Search: 428/280, 428/281, 428/296, 428/283, 428/331, 428/317.9, 428/903, 428/408, 428/323, 428/284, 264/122, 156/199, 156/221, 427/180, 55/316
• US Class Current: 442/351
• CPC Class Codes: B01D 15/08 Selective adsorption, e.g. chromatography
• CPC Class Codes: B01D 15/361 Ion-exchange
• CPC Class Codes: B01D 15/3804 Affinity chromatography
• CPC Class Codes: B01D 15/3833 Chiral chromatography
• CPC Class Codes: B01J 20/28014 characterised by their form
• CPC Class Codes: B01J 20/28028 Particles immobilised within fibres or filaments
• CPC Class Codes: B01J 20/28033 Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: B01J 20/28052 Several layers of identical or different sorbents stacked in a housing, e.g. in a column
• CPC Class Codes: B01J 20/28085 being more than 50 nm, i.e. macropores
• CPC Class Codes: B01J 47/018 Granulation; Incorporation of ion-exchangers in a matrix; Mixing with inert materials
• CPC Class Codes: D04H 1/54 by welding together the fibres, e.g. by partially melting or dissolving in combination with needling D04H1/485
• CPC Class Codes: D04H 1/56 in association with fibre formation, e.g. immediately following extrusion of staple fibres
• CPC Class Codes: G01N 2030/528 Monolithic sorbent material
• CPC Class Codes: Y10S 428/903 Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10T 156/1007 Running or continuous length work
• CPC Class Codes: Y10T 156/1043 Subsequent to assembly
• CPC Class Codes: Y10T 428/249986 Void-containing component contains also a solid fiber or solid particle
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 442/626 Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/699 Including particulate material other than strand or fiber material

Abstract

A particle loaded, porous, fibrous compressed or fused article comprises a nonwoven fibrous polymeric web, which preferably is thermoplastic, melt-extrudable, and pressure-fusible blown microfibrous web, and sorptive particles enmeshed in said web, the particle loaded fibrous article has a Gurley number of at least two seconds, and the article is useful in separation science. A method of preparation of the article and method of use is also disclosed.

Claims

1. A particle loaded, porous, fibrous, at least one of at least one of compressed or fused, article comprising

a) a thermoplastic nonwoven fibrous polymeric web, and

b) sorptive particles enmeshed in said web,

wherein said particle loaded fibrous article has been compressed or fused by at least one of calendering, heating, and applying pressure to provide said article with controlled porosity and a Gurley number of at least four seconds, and wherein said article is useful in separation science.

2. The article according to claim 1 comprising a nonwoven fibrous web selected from the group consisting of polyamide, polyolefin, polyurethane, polyester, and polyvinylhalide.

3. The article according to claim 1 having a thickness of at least 20 percent less than an unpressed article.

4. The article according to claim 1 comprising in the range of 30 to 70 volume percent polymeric fibers and in the range of 70 to 30 volume percent air.

5. The article according to claim 2 wherein said polyolefin is polypropylene.

6. The article according to claim 1 wherein said particles are selected from the group consisting of an organic compound or polymer, an inorganic oxide, carbon, and a support particle coated with an insoluble, non-swellable sorbed or bonded coating.

7. The article according to claim 4 wherein said inorganic oxide is selected from the group consisting of silica, alumina, titania, and zirconia.

8. The article according to claim 6 wherein said sorbed coating is polybutadiene or said covalently bonded coating is selected from the group consisting of a cyano, cyclohexyl, octyl, and octadecyl group.

9. The article according to claim 1 wherein said polymer is present in the range of 5 to less than 100 weight percent and said particles are present in the range of more than 0 to 95 weight percent.

10. The article according to claim 1 wherein said particles comprise at least 20 weight percent of said fibrous web.

11. The article according to claim 1 wherein said particles comprise at least 50 weight percent of said fibrous web.

12. The article according to claim 1 wherein said particles comprise at least 80 weight percent of the fibrous web.

13. The article according to claim 1 further comprising up to 20 weight percent property modifiers to aid at least one of increasing hydrophilicity or hydrophobicity, to indicate pH, to facilitate processing, and in coloring.

14. The article according to claim 1 wherein said pores have a mean pore size in the range of 0.2 to 10 micrometers.

15. The article according to claim 1 wherein said Gurley time is at least 5.

16. The article according to claim 1 wherein said sorptive particles are ion-exchange or chelating particles.

17. The article according to claim 1 wherein said sorptive particles have chiral functionality.

18. The article according to claim 1 wherein said sorptive particles have affinity functionality.

19. The article according to claim 1 which is a solid phase extraction medium.

20. The article according to claim 1 which is a chromatographic medium.

21. A stack of 2 or more disks wherein each disk is a solid phase extraction medium and at least one of said disks is according to claim 1.

22. The article according to claim 1 wherein said thermoplastic, nonwoven, fibrous, polymeric web is a melt-blown web.