Intumescent, flame retardant pressure sensitive adhesive composition for EMI shielding applications

Claim 2

A flame retardant, EMI shielding material comprising: an electrically-conductive layer having first surface and a second surface; and a flame retardant pressure sensitive adhesive (PSA) layer disposed on one or both of said first or second surface of said electrically-conductive layer, said PSA layer being formed of an intumescent PSA composition comprising an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles.

Claim 3

The EMI shielding material of claim 1 wherein said intumescent PSA composition comprises, by weight of components (a)-(d), less than about 70% of said PSA component (a); less than about 10% of said halogenated first flame retardant component (b); less than about 20% of said metal-based second flame retardant component (c); and less than about 20% of said filler component (d).

Claim 4

The EMI shielding material of claim 1 wherein said PSA component (a) is acrylic-based; said halogenated first flame retardant component (b) is a polybrominated diphenyl compound; and said metal-based second flame retardant component (c) is antimony-based.

Claim 5

The EMI shielding material of claim 3 wherein said halogenated first flame retardant component (b) is decabromodiphenyl oxide or decabromodiphenyl ether, and said second flame retardant component (c) is antimony oxide, antimony trioxide, or antimony pentoxide.

Claim 6

The EMI shielding material of claim 1 wherein said filler component (d) is expandable graphite flake.

Claim 7

The EMI shielding material of claim 5 wherein said graphite flake has a mean average particle size of between 50-100 mesh (300-100 μm).

Claim 8

The EMI shielding material of claim 1 wherein said PSA layer has a thickness of between about 5-50 mils (0.125-1.25 mm).

Claim 9

The EMI shielding material of claim 1 wherein said electrically-conductive layer is fabric or mesh which comprises: cotton, wool, silk, cellulose, polyester, polyamide, nylon, or polyimide fibers having an electrically-conductive coating wherein said coating is copper, nickel, silver, aluminum, tin, carbon, graphite, or a combination thereof; copper, nickel, silver, aluminum, bronze, and tin wire and alloys thereof; carbon, graphite, and conductive polymer fibers; or combinations thereof.

Claim 10

The EMI shielding material of claim 8 wherein said electrically-conductive layer comprises a metal foil.

Claim 11

The EMI shielding material of claim 9 further comprising a fabric reinforcement layer interposed between said electrically-conductive layer and said PSA layer.

Claim 12

A flame retardant, intumescent pressure sensitive adhesive (PSA) composition comprising an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles.

Claim 13

A flame retardant, intumescent pressure sensitive adhesive (PSA) composition comprising an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles.

Claim 14

The PSA composition of claim 11 which comprises, by weight of components (a)-(d), less than about 70% of said PSA component (a); less than about 10% of said halogenated first flame retardant component (b); less than about 20% of said metal-based second flame retardant component (c); and less than about 20% of said filler component (d).

Claim 15

The PSA composition of claim 11 wherein said PSA component (a) is acrylic-based; said halogenated first flame retardant component (b) is a polybrominated diphenyl compound; and said metal-based second flame retardant component (c) is antimony-based.

Claim 16

The PSA composition of claim 13 wherein said halogenated first flame retardant component (b) is decabromodiphenyl oxide or decabromodiphenyl ether, and said second flame retardant component (c) is antimony oxide, antimony trioxide, or antimony pentoxide.

Claim 17

The PSA composition of claim 11 wherein said filler component (d) is expandable graphite flake.

Claim 18

The PSA composition of claim 15 wherein said graphite flake has a mean average particle size of between about 50-100 mesh (300-100 μm).

Claim 19

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 in defining a widthwise extent of said gasket; an electrically-conductive outer member externally surrounding said core member, said outer member being wrapped over the widthwise extent of said gasket and having an interior surface disposed facing the outer surface of said core member and an oppositely-facing exterior surface; and a flame retardant, pressure sensitive adhesive (PSA) layer covering at least a portion of the interior surface of said outer member and bonding said outer member to the outer surface of said core member, said PSA layer being formed of an intumescent PSA composition comprising an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles.

Claim 20

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 in defining a widthwise extent of said gasket; an electrically-conductive outer member externally surrounding said core member, said outer member being wrapped over the widthwise extent of said gasket and having an interior surface disposed facing the outer surface of said core member and an oppositely-facing exterior surface; and a flame retardant, pressure sensitive adhesive (PSA) layer covering at least a portion of the interior surface of said outer member and bonding said outer member to the outer surface of said core member, said PSA layer being formed of an intumescent PSA composition comprising an admixture of: (a) a PSA component; (b) a halogenated first flame retardant component; (c) a metal-based second flame retardant component; and (d) a filler component of expandable, intercalated graphite particles.

Claim 21

The gasket of claim 17 wherein said PSA composition comprises, by weight of components (a)-(d), less than about 70% of said PSA component (a); less than about 10% of said halogenated first flame retardant component (b); less than about 20% of said metal-based second flame retardant component (c); and less than about 20% of said filler component (d).

Claim 22

The gasket of claim 17 wherein said PSA component (a) is acrylic-based; said halogenated first flame retardant component (b) is a polybrominated diphenyl compound; and said metal-based second flame retardant component (c) is antimony-based.

Claim 23

The gasket of claim 19 wherein said halogenated first flame retardant component (b) is decabromodiphenyl oxide or decabromodiphenyl ether, and said second flame retardant component (c) is antimony oxide, antimony trioxide, or antimony pentoxide.

Claim 24

The gasket of claim 17 wherein said filler component (d) is expandable graphite flake.

Claim 25

The gasket of claim 21 wherein said graphite flake has a mean average particle size of between about 50-100 mesh (300-100 μm).

Claim 26

The gasket of claim 17 wherein said PSA layer has a thickness of between about 5-50 mils (0.125-1.25 mm).

Claim 27

The gasket of claim 17 wherein said electrically-conductive outer comprises a fabric or mesh selected from the group consisting of: cotton, wool, silk, cellulose, polyester, polyamide, nylon, and polyimide fibers coated with an electrically-conductive material wherein said material is copper, nickel, silver, aluminum, tin, carbon, graphite, or a combination thereof; copper, nickel, silver, aluminum, bronze, and tin wire and alloys thereof, carbon, graphite, and conductive polymer fibers; and combinations thereof.

Claim 28

The gasket of claim 24 wherein said electrically-conductive outer layer comprises a metal foil.

Claim 29

The gasket of claim 25 further comprising a fabric reinforcement layer interposed between said electrically-conductive layer and said PSA layer.

Claim 30

The gasket of claim 17 wherein said core member is formed of a foamed elastomeric material selected from the group consisting of polyethylenes, polypropylenes, polypropylene-EPDM blends, butadienes, styrene-butadienes, nitriles, chlorosulfonates, neoprenes, urethanes, silicones, and combinations thereof.