BREATHABLE, CHEMICAL RESISTANT, DURABLE, AND WATERPROOF COATED POROUS MEMBRANE

• US 20100255741A1
• Filed: 04/02/2009
• Published: 10/07/2010
• Est. Priority Date: 04/02/2009
• Status: Active Grant

• Current Assignee: Parker-Hannifin Corporation
• Original Assignee: BHA Group Incorporated (GE Vernova, Inc.)
• Inventors: Tee, Yit-Hong, Abujoudeh, Taher
• Granted Patent: US 8,334,227 B2
• Time in Patent Office: Days
• US Class Current: 442/77
• CPC Class Codes: B32B 2264/0257 Polyolefin particles, e.g. polyethylene or polypropylene homopolymers or ethylene-propylene copolymers
• CPC Class Codes: B32B 2274/00 Thermoplastic elastomer material
• CPC Class Codes: B32B 23/046 of natural rubber or synthetic rubber
• CPC Class Codes: B32B 2307/714 Inert, i.e. inert to chemical degradation, corrosion
• CPC Class Codes: B32B 2307/724 Permeability to gases, adsorption
• CPC Class Codes: B32B 2307/7265 Non-permeable
• CPC Class Codes: B32B 2307/73 Hydrophobic
• CPC Class Codes: B32B 2437/00 Clothing
• CPC Class Codes: B32B 25/047 of particles
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 25/10 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 2571/00 Protective equipment
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/12 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 27/14 next to a particulate layer
• CPC Class Codes: B32B 27/281 comprising polyimides
• CPC Class Codes: B32B 27/286 comprising polysulphones; polysulfides
• CPC Class Codes: B32B 27/304 comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• CPC Class Codes: B32B 27/322 comprising halogenated polyolefins, e.g. PTFE
• CPC Class Codes: B32B 27/34 comprising polyamides
• CPC Class Codes: B32B 27/36 : comprising polyesters
• CPC Class Codes: B32B 27/40 : comprising polyurethanes
• CPC Class Codes: B32B 5/022 : Non-woven fabric
• CPC Class Codes: B32B 5/024 : Woven fabric
• CPC Class Codes: B32B 5/026 : Knitted fabric
• CPC Class Codes: Y10T 428/24289 : Embedded or interlocked
• CPC Class Codes: Y10T 428/24322 : Composite web or sheet
• CPC Class Codes: Y10T 428/24512 : Polyurethane
• CPC Class Codes: Y10T 428/249978 : Voids specified as micro
• CPC Class Codes: Y10T 428/24998 : Composite has more than two layers
• CPC Class Codes: Y10T 442/2148 : Coating or impregnation is specified as microporous but is not a foam
• CPC Class Codes: Y10T 442/2328 : Organosilicon containing
• CPC Class Codes: Y10T 442/2344 : Coating or impregnation is anti-slip or friction-increasing other than specified as an abrasive
• CPC Class Codes: Y10T 442/674 : Nonwoven fabric with a preformed polymeric film or sheet

Abstract

A waterproof, vapor-permeable and air-permeable sheet material. The sheet material includes a waterproof microporous polymer substrate and a microporous thermoplastic coating layer attached to the polymer substrate. The thermoplastic coating layer is vapor-permeable and air-permeable. The thermoplastic coating layer is at least partially interpenetrated into pores of the polymer substrate forming an interface that prevents passage of water droplets, while permitting passage of water vapor and air, when a chemical is present on the sheet material that would otherwise cause the polymer substrate to permit passage of water droplets. The interface is resistant to chemical interference with at least the waterproof property of the sheet material.

Claims

1. A waterproof, vapor-permeable and air-permeable sheet material including:

a waterproof microporous polymer substrate;

a microporous thermoplastic coating layer attached to the polymer substrate, the thermoplastic coating layer being vapor-permeable and air-permeable; and

the thermoplastic coating layer being at least partially interpenetrated into pores of the polymer substrate forming an interface that prevents passage of water droplets, while permitting passage of water vapor and air, when a chemical is present on the sheet material that would otherwise cause the polymer substrate to permit passage of water droplets.

2. The sheet material of claim 1, wherein the polymer substrate is expanded polytetrafluoroethylene.

3. The sheet material of claim 1, wherein the polymer substrate includes at least one of a fluoropolymer, sulfonated polymer, polyamide, polyimide, and cellulosic polymer.

4. The sheet material of claim 1, wherein the thermoplastic coating layer is polyurethane.

5. The sheet material of claim 1, wherein the thermoplastic coating layer is an elastomer.

6. The sheet material of claim 1, wherein the sheet material includes at least one of woven fabrics, nonwoven fabrics, knitted fabrics, and yam.

7. The sheet material of claim 1, wherein the at least partially interpenetrated thermoplastic coating layer into the pores of the polymer substrate is provided by heated melt of the thermoplastic coating layer.

8. The sheet material of claim 7, wherein the heated melt includes heating a first temperature, subsequently heating at a second temperature that is higher than the first temperature, and then subsequently heating at a third temperature that is higher than the second temperature.

9. A waterproof, vapor-permeable and air-permeable sheet material including:

a waterproof microporous polymer substrate;

a microporous thermoplastic coating layer attached to the polymer substrate, the thermoplastic coating layer being vapor-permeable and air-permeable; and

the thermoplastic coating layer being at least partially interpenetrated into pores of the polymer substrate forming an interface that is resistant to chemical interference with at least the waterproof property of the sheet material.

10. The sheet material of claim 9, wherein the polymer substrate is expanded polytetrafluoroethylene.

11. The sheet material of claim 9, wherein the polymer substrate includes at least one of a fluoropolymer, sulfonated polymer, polyamide, polyimide, and cellulosic polymer.

12. The sheet material of claim 9, wherein the thermoplastic coating layer is polyurethane.

13. The sheet material of claim 9, wherein the thermoplastic coating layer is an elastomer.

14. The sheet material of claim 9, wherein the sheet material includes at least one of woven fabrics, nonwoven fabrics, knitted fabrics, and yarn.

15. The sheet material of claim 9, wherein the at least partially interpenetrated thermoplastic coating layer into the pores of the polymer substrate is provided by heated melt of the thermoplastic coating layer.

16. The sheet material of claim 15, wherein the heated melt includes heating a first temperature, subsequently heating at a second temperature that is higher than the first temperature, and then subsequently heating at a third temperature that is higher than the second temperature.