Metal-coated shielding materials and articles fabricated therefrom

The present invention features a new shield material useful in the fabrication of shielded wire or cable articles. The conductive core of the wire and cable is layered with a shielding wrapping tape, foil or film. A shielding insulation compound can also be extruded over the conductive wire or cable core. Wire and cable articles containing the new shield material have an extended interference frequency attenuation range resulting from the improved shield layer. The shield material contains metal-coated magnetic particles dispersed within a polymeric binder, such as a fluorocarbon polymer. Other particles of metal such as copper, silver, nickel, manganese, zinc, or silver-coated copper in combination with metal coated and non-coated ferrites and magnetites dispersed within the polymer matrix may also be part of the blend formulation. The shielded wire or cable attenuates both RFI/EMI and microwave/radar interferences. The conductive particles themselves provide the attenuation of the electromagnetic (EM) wave throughout the entire frequency range, while the metal coating on the magnetic particles provide attenuation of the magnetic component of the EM wave at high frequencies exceeding 100 MHz. The shield layer ratio of conductive particles to metal-coating on the ferrite particles can be tuned to provide attenuation within a particularly troublesome frequency range, and can also provide attenuation throughout the entire frequency range.