Flame retardant EMI shielding gasket

• US 6,387,523 B2
• Filed: 06/18/2001
• Issued: 05/14/2002
• Est. Priority Date: 02/27/1998
• Status: Expired due to Term

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: Parker-Hannifin Corporation
• Inventors: Bunyan, Michael H., Flanders, William I.
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US09/883,785
• Publication Number:
  US 20010031589A1
• Time in Patent Office: 330 Days
• Field of Search: 428/457
• US Class Current: 428/457
• CPC Class Codes: H05K 9/0015 Gaskets or seals
• CPC Class Codes: Y10T 428/215 Seal, gasket, or packing
• CPC Class Codes: Y10T 428/24996 With internal element bridging layers, nonplanar interface between layers, or intermediate layer of commingled adjacent foam layers
• CPC Class Codes: Y10T 428/24997 Of metal-containing material
• CPC Class Codes: Y10T 428/249974 Metal- or silicon-containing element
• CPC Class Codes: Y10T 428/24998 Composite has more than two layers
• CPC Class Codes: Y10T 428/24999 Inorganic
• CPC Class Codes: Y10T 428/31678 Of metal
• CPC Class Codes: Y10T 442/109 Metal or metal-coated fiber-containing scrim
• CPC Class Codes: Y10T 442/2418 Coating or impregnation increases electrical conductivity or anti-static quality
• CPC Class Codes: Y10T 442/2631 Coating or impregnation provides heat or fire protection
• CPC Class Codes: Y10T 442/2656 Antimony containing
• CPC Class Codes: Y10T 442/268 Phosphorus and nitrogen containing compound
• CPC Class Codes: Y10T 442/2713 Halogen containing
• CPC Class Codes: Y10T 442/3049 Including strand precoated with other than free metal or alloy
• CPC Class Codes: Y10T 442/3325 Including a foamed layer or component
• CPC Class Codes: Y10T 442/3333 Including a free metal or alloy constituent
• CPC Class Codes: Y10T 442/3366 Woven fabric is coated, impregnated, or autogenously bonded
• CPC Class Codes: Y10T 442/3382 Including a free metal or alloy constituent

Abstract

A flame retardant, electromagnetic interference (EMI) shielding gasket construction. The construction includes a resilient core member formed of a foamed elastomeric material, an electrically-conductive fabric member surrounding the outer surface of the core member, and a flame retardant layer coating at least a portion of the interior surface of the fabric member. The flame retardant layer is effective to afford the gasket construction with a flame class rating of V-0 under Underwriter'"'"'s Laboratories (UL) Standard No. 94.

Claims

1. A flame retardant, electromagnetic interference (EMI) shielding gasket comprising:

a resilient core member extending lengthwise along a central longitudinal axis and having an outer surface extending circumferentially about said longitudinal axis, said core member being formed of a foamed elastomeric material;

an electrically-conductive fabric member surrounding the outer surface of said core member, said fabric member having an interior surface disposed facing the outer surface of said core member and an oppositely-facing exterior surface at least the exterior surface being electrically-conductive and the exterior surface defining with the interior surface a thickness dimension of the fabric member therebetween; and

a flame retardant layer coating at least a portion of the interior surface of said fabric member, said flame retardant layer penetrating into said fabric member to a depth which is less than the thickness dimension of said fabric member such that the exterior surface of said fabric member remains electrically-conductive.

2. The gasket of claim 1 wherein said flame retardant layer has a thickness of between about 2-4 mils (0.05-0.10 mm).

3. The gasket of claim 1 wherein said flame retardant layer is formed as a cured film of a flame retardant acrylic latex emulsion.

4. The gasket of claim 1 wherein said fabric member is a metal-plated cloth.

5. The gasket of claim 4 wherein said cloth comprises fibers selected from the group consisting of cotton, wool, silk, cellulose, polyester, polyamide, nylon, and combinations thereof, and said metal is selected from the group consisting of copper, nickel, silver, nickel-plated-silver, aluminum, tin, and combinations thereof.

6. The gasket of claim 1 wherein said foamed elastomeric material is selected from the group consisting of polyethylenes, polypropylenes, polypropylene-EPDM blends, butadienes, styrene-butadienes, nitrites, chlorosulfonates, neoprenes, urethanes, silicones, and polyolefin resin/monoolefin copolymer blends, and combinations thereof.

7. The gasket of claim 1 wherein said fabric member has a thickness of between about 2-4 mils (0.05-0.10 mm).

8. The gasket of claim 1 wherein said flame retardant layer is effective to afford the gasket a flame class rating of V-0 under Underwriter'"'"'s Laboratories (UL) Standard No. 94.