Electromagnetic radiation absorptive coating composition containing metal coated microspheres
AssigneeSpectro Dynamics Systems, L.P.
InventorsWayne Laval Gindrup, Rebecca Reeves Vinson
Life of this patent
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Abstract
A strong lightweight composition containing metal coated microspheres has very broad band absorption properties for electromagnetic radiation and is useful as a thin coating or as a structural composite material in various applications. The microspheres have a diameter of from 1 to 350 microns and contain at least one radiation absorbing material selected from the group consisting of carbon, ferrites, magnetite, iron, nickel and cobalt, and have a thin-coating of metal on the microsphere surface. The metal coating is present at a weight percentage of 0.01 percent to 22 percent.
Claims21
An electromagnetic radiation absorptive composition which comprises an electromagnetic radiation nonabsorptive binder, and a plurality of electromagnetic radiation absorptive microspheres dispersed in said binder, said microspheres having a diameter from 1 to 350 microns, said microspheres containing at least one material selected from the group consisting of carbon, ferrites, magnetite, iron, nickel and cobalt;
- and having a thin coating of metal on the microsphere surface, said metal coating being present at a percentage by weight of 0.01 percent to 22 percent, and said coating being so thin that appreciable light transmission occurs when the microspheres are examined microscopically and so that the microspheres absorb electromagnetic radiation.
An electromagnetic radiation absorptive composition which comprises an electromagnetic radiation non-absorptive binder;
- and a multiplicity of electromagnetic radiation absorptive microspheres dispersed in said binder, said microspheres having a diameter of from 1 to 350 microns and containing at least one material selected from the group consisting of carbon, ferrites, magnetite, iron, nickel and cobalt, said microspheres having a bright mirror-like metal plating uniformly covering the microspheres surface, said metal plating being present at a percentage by weight of 0.01 to 22 percent and being of such a thickness as to provide a resistivity of from 0.2 ohms to 200 ohms.
A structure which absorbs electromagnetic radiation comprising an electrically conductive substrate, an insulating coating of an electrically insulating material overlying said substrate, and an electromagnetic radiation absorptive coating overlying said insulating coating, said electromagnetic radiation absorptive coating comprising a binder and a multiplicity of microspheres dispersed in and bound by said binder, said microspheres having a diameter of from 1 to 350 microns and containing at least one radiation absorptive material selected from the group consisting of carbon, ferrites, magnetite, iron, nickel and cobalt;
- and having a thin radiation absorbing metal plating on the microsphere surface, said metal plating being present at a percentage by weight of 0.01 percent to 22 percent.
Dependencies are inferred from the claim text.