Electromagnetic wave-shielding materials
First Claim
1. An electromagnetic wave-shielding material comprising:
- (1) an electromagnetic wave-shielding layer comprised of;
(A) a thermoplastic resin;
(B) an aluminum or aluminum alloy; and
(C) electrically conductive carbon black; and
(2) a surface layer comprised of a thermoplastic resin, wherein;
(a) the thermoplastic resin (A) is selected from the group consisting of;
(i) polyolefins modified with unsaturated carboxylic acids or derivatives of unsaturated carboxylic acids;
(ii) copolymers of ethylene and unsaturated carboxylic acids and/or anhydrides thereof;
(iii) copolymers of ethylene and an alkyl acrylate and/or an alkyl methacrylate;
(iv) styrene-based resins;
(v) vinyl chloride-based resins;
(vi) polyamide resins;
(vii) polycarbonate resins; and
(viii) polyolefins,(b) the aluminum or aluminum alloy is in the form of;
(i) particles having a mean size of 250 to 20 mesh;
(ii) a fiberous aluminum or a fiberous aluminum alloy having a diameter of from 0.002 to 0.05 mm and a length of 10 mm or less;
or (iii) a flake having a surface area of from 0.1×
0.1 mm to 5×
5 mm,(c) the electrically conductive carbon black has a specific surface area of from 20 to 1,800 m2 /g, and(d) the proportions of the electrically conductive carbon black and the aluminum or aluminum alloy in the electromagnetic wave-shielding layer are from 5 to 50% by volume, respectively, provided that the total proportion of the carbon black and the aluminum or aluminum alloy is from 10 to 60% by volume, and the difference in solubility parameter between the thermoplastic resin of the surface layer and the thermoplastic resin (A) of the electromagnetic wave-shielding layer is 3.0 or less.
1 Assignment
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Accused Products
Abstract
An electromagnetic wave-shielding material is disclosed. The material is comprised of one or more electromagnetic wave-shielding layers and one or more surface layers. The shielding layers are comprised of a thermoplastic resin, an aluminum or aluminum alloy and electrically conductive carbon black. The surface layers are comprised substantially of thermoplastic resin. The proportion of the carbon black and aluminum in the shielding layer are from 5 to 50% by volume and 5 to 50% by volume, respectively, provided the total proportion of the carbon black and aluminum is 10 to 60% by volume. The difference in solubility parameter between the thermoplastic resin of the surface layer and the thermoplastic resin of the shielding layer is 3.0 or less. The material has superior mechanical strength and electromagnetic wave-shielding properties.
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Citations
12 Claims
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1. An electromagnetic wave-shielding material comprising:
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(1) an electromagnetic wave-shielding layer comprised of; (A) a thermoplastic resin; (B) an aluminum or aluminum alloy; and (C) electrically conductive carbon black; and (2) a surface layer comprised of a thermoplastic resin, wherein; (a) the thermoplastic resin (A) is selected from the group consisting of; (i) polyolefins modified with unsaturated carboxylic acids or derivatives of unsaturated carboxylic acids; (ii) copolymers of ethylene and unsaturated carboxylic acids and/or anhydrides thereof; (iii) copolymers of ethylene and an alkyl acrylate and/or an alkyl methacrylate; (iv) styrene-based resins; (v) vinyl chloride-based resins; (vi) polyamide resins; (vii) polycarbonate resins; and (viii) polyolefins, (b) the aluminum or aluminum alloy is in the form of;
(i) particles having a mean size of 250 to 20 mesh;
(ii) a fiberous aluminum or a fiberous aluminum alloy having a diameter of from 0.002 to 0.05 mm and a length of 10 mm or less;
or (iii) a flake having a surface area of from 0.1×
0.1 mm to 5×
5 mm,(c) the electrically conductive carbon black has a specific surface area of from 20 to 1,800 m2 /g, and (d) the proportions of the electrically conductive carbon black and the aluminum or aluminum alloy in the electromagnetic wave-shielding layer are from 5 to 50% by volume, respectively, provided that the total proportion of the carbon black and the aluminum or aluminum alloy is from 10 to 60% by volume, and the difference in solubility parameter between the thermoplastic resin of the surface layer and the thermoplastic resin (A) of the electromagnetic wave-shielding layer is 3.0 or less. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification