Polymer, polymer microfiber, polymer nanofiber and applications including filter structures

• US 6,743,273 B2
• Filed: 05/31/2001
• Issued: 06/01/2004
• Est. Priority Date: 09/05/2000
• Status: Expired due to Term

• Current Assignee: Donaldson Company Incorporated
• Original Assignee: Donaldson Company Incorporated
• Inventors: Chung, Hoo Y., Hall, John R. B., Gogins, Mark A., Weik, Thomas M., Crofoot, Douglas G.
• Primary Examiner(s): Smith, Duane
• Assistant Examiner(s): Greene, Jason M.
• Application Number:
  US09/871,583
• Publication Number:
  US 20030106294A1
• Time in Patent Office: 1,097 Days
• Field of Search: 554/82, 554/86, 554/87, 553/851, 553/853, 555/27, 555/28, 555/29, 553/02, 555/25, 555/26, 555/24, 442/36
• US Class Current: 55/482
• CPC Class Codes: B01D 2239/025 comprising nanofibres
• CPC Class Codes: B01D 2239/0428 Rendering the filter material hydrophobic
• CPC Class Codes: B01D 2239/0492 on fibres
• CPC Class Codes: B01D 2239/0613 Woven
• CPC Class Codes: B01D 2239/0618 Non-woven
• CPC Class Codes: B01D 2239/0627 Spun-bonded
• CPC Class Codes: B01D 2239/064 The fibres being mixed
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material
• CPC Class Codes: B01D 2239/0654 Support layers
• CPC Class Codes: B01D 2239/1233 Fibre diameter
• CPC Class Codes: B01D 2239/1258 Permeability
• CPC Class Codes: B01D 2275/10 Multiple layers
• CPC Class Codes: B01D 39/04 Organic material, e.g. cellulose, cotton
• CPC Class Codes: B01D 39/086 of inorganic material
• CPC Class Codes: B01D 39/1623 of synthetic origin
• CPC Class Codes: B01D 39/163 sintered or bonded
• CPC Class Codes: B01D 39/18 the material being cellulose or derivatives thereof cork or peat B01D39/1646 ; making filter paper D21F11/14
• CPC Class Codes: B01D 46/0001 Making filtering elements
• CPC Class Codes: B01D 46/02 Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
• CPC Class Codes: B01D 46/10 Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• CPC Class Codes: B01D 46/2411 : Filter cartridges
• CPC Class Codes: B01D 46/521 : using folded, pleated material
• CPC Class Codes: B01D 46/523 : with means for maintaining spacing between the pleats or folds
• CPC Class Codes: B01D 46/546 : using nano- or microfibres
• CPC Class Codes: C08L 65/00 : Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 77/00 : Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain of polyhydrazides C08L79/06; of polyamideimides or polyamide acids C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: D01D 5/0007 : Electro-spinning non-woven fabrics produced by electro-spinning D04H1/728
• CPC Class Codes: D01D 5/003 : the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01D 5/0084 : Coating by electro-spinning, i.e. the electro-spun fibres are not removed from the collecting device but remain integral with it, e.g. coating of prostheses
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: D01F 6/80 : from copolyamides
• CPC Class Codes: D01F 6/90 : of polyamides
• CPC Class Codes: D01F 6/92 : of polyesters
• CPC Class Codes: D04H 3/02 : characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
• CPC Class Codes: Y10S 428/903 : Microfiber, less than 100 micron diameter
• CPC Class Codes: Y10T 428/1362 : Textile, fabric, cloth, or pile containing [e.g., web, net, woven, knitted, mesh, nonwoven, matted, etc.]
• CPC Class Codes: Y10T 428/24686 : Pleats or otherwise parallel adjacent folds
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/26 : Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension
• CPC Class Codes: Y10T 428/29 : Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2915 : including textile, cloth or fabric
• CPC Class Codes: Y10T 428/2933 : Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/2938 : Coating on discrete and individual rods, strands or filaments
• CPC Class Codes: Y10T 428/2967 : Synthetic resin or polymer
• CPC Class Codes: Y10T 428/2969 : Polyamide, polyimide or polyester
• CPC Class Codes: Y10T 428/298 : Physical dimension
• CPC Class Codes: Y10T 442/16 : Two or more nonwoven layers
• CPC Class Codes: Y10T 442/614 : Strand or fiber material specified as having microdimensions [i.e., microfiber]
• CPC Class Codes: Y10T 442/626 : Microfiber is synthetic polymer
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric

Abstract

Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.

Claims

1. A filter media comprising a fine fiber layer and a substrate layer having a basis weight of about 8 to 200 grams/meter², the fine fiber comprising a blend of a hydrophobic additive and a polymer comprising a blend of at least two different polymers, the fine fiber having a fiber size of about 0.01 to 0.5 micron, the substrate comprising a filtration media;

wherein after exposure to air at 140°

F. and 100% relative humidity for 1 to 16 hours, at least 50% of the fine fiber remains substantially unchanged.

2. The media of claim 1 wherein the fine fiber layer can be exposed to an alcoholic solvent at 70°

F. and wherein at least 50% of the fiber remains after 5 minutes.

3. The media of claim 1 wherein a temperature of 160°

F. is used for 3 hours.

4. The media of claim 1 wherein the fine fiber comprises a blend of two nylon polymers and has a diameter of 0.1 to 0.5 micron.

5. The media of claim 1 wherein the fine fiber has a diameter of 0.01 to 0.2 micron.

6. The media of claim 1 wherein the fine fiber layer survives immersion in hot water at 140°

F. and at least 50% of the fiber survives after 5 minutes.

7. The media of claim 1 wherein the media, when exposed to an air stream having a temperature of about 140°

F. and a relative humidity of about 100%, greater than about 50% of the fiber survives for more than 16 hours.

8. The media of claim 1 wherein a temperature of 160°

F. is used.

9. The media of claim 1 wherein the filter media also comprises a woven or non-woven substrate.

10. The media of claim 9 wherein the non-woven substrate comprises a fiber selected from cellulose, glass, polymer, metal, and combinations thereof.

11. The media of claim 1 wherein the substrate comprises spunbonded polymeric non-woven fabric.

12. The media of claim 1 wherein the substrate comprises a non-woven polymeric fabric.

13. The media of claim 1 wherein the substrate comprises a knit fabric.

14. The media of claim 12 wherein the fine fiber comprises a microfiber having a diameter of about 0.1 to 0.5 micron.

15. The media of claim 12 wherein the fine fiber comprises a nanofiber having a diameter of about 0.01 to 0.2 micron.