Composite material for shielding against electromagnetic radiation

• US 4,471,015 A
• Filed: 07/14/1983
• Issued: 09/11/1984
• Est. Priority Date: 07/01/1980
• Status: Expired due to Fees

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Fitzky, Hans G., Oberkirch, Wolfgang, Ebneth, Harold
• Primary Examiner(s): Bell, James J.
• Application Number:
  US06/513,893
• Time in Patent Office: 425 Days
• Field of Search: 523/137, 523/215, 523/222, 174/35 MS, 174/35 GC, 174/35 R, 428/195, 428/206, 428/209, 428/283, 428/323, 428/328, 428/375, 428/379, 428/381, 428/389, 428/403, 428/922, 428/936
• US Class Current: 428/195.1
• CPC Class Codes: B29C 70/885 with incorporated metallic wires, nets, films or plates as lost heating elements B29C35/0272, B29C61/0625
• CPC Class Codes: B29K 2105/0809 Fabrics
• CPC Class Codes: B29K 2995/0005 Conductive
• CPC Class Codes: D04H 1/407 containing absorbing substances, e.g. activated carbon
• CPC Class Codes: D04H 1/42 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: H01Q 17/005 using woven or wound filaments; impregnated nets or clothes
• CPC Class Codes: H05K 9/0088 comprising a plurality of shielding layers; combining different shielding material structure
• CPC Class Codes: Y10S 428/922 Static electricity metal bleed-off metallic stock
• CPC Class Codes: Y10S 428/936 Chemical deposition, e.g. electroless plating
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/2481 including layer of mechanically interengaged strands, strand-portions or strand-like strips
• CPC Class Codes: Y10T 428/24818 Knitted, with particular or differential bond sites or intersections
• CPC Class Codes: Y10T 428/24893 including particulate material
• CPC Class Codes: Y10T 428/24909 Free metal or mineral containing
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/261 In terms of molecular thickness or light wave length
• CPC Class Codes: Y10T 428/2938 Coating on discrete and individual rods, strands or filaments
• CPC Class Codes: Y10T 428/2958 Metal or metal compound in coating
• CPC Class Codes: Y10T 428/2973 Particular cross section
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2998 : including synthetic resin or polymer
• CPC Class Codes: Y10T 428/30 : Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31678 : Of metal
• CPC Class Codes: Y10T 442/2607 : Radiation absorptive
• CPC Class Codes: Y10T 442/655 : Metal or metal-coated strand or fiber material

Abstract

A composite material comprising a polymer matrix containing metallized sheet-form textiles and/or metallized particles, and in addition additives for increasing the ohmic, electrical and/or magnetic losses which are uniformly present in the polymer and/or on the sheet-form textiles and/or particles, has a high shielding effect against electromagnetic radiation both in the short-range field and also in the long-range field over a wide frequency range.

Claims

1. A composite material comprising:

metallized particles contained in a polymer matrix with additives for increasing at least one of the ohmic, electrical and magnetic losses uniformly present in the polymer or on the particles, wherein the additives includes pigments or conductive carbon black in concentrations of no greater than 10% by weight and wherein the particles are at least partly surrounded by a 0.05 to 20 μ

m thick, highly conductive metal layer applied by currentless wet-chemical deposition.

2. A composite material as claimed in claim 1, wherein unmetallized regions are present on the particles and wherein the metallized regions are separated by intervals of from 0.01 to 10 μ

m.

3. A composite material as claimed in claim 1, wherein the layer thickness is from 0.05 to 20 mm.

4. A composite material as claimed in claim 1, wherein the particles are rodlet like.

8. A composite material as claimed in claim 1, wherein the material is overcoated.

9. A shielding material for electromagnetic radiation of no less than 0.05 GHz, comprising the composite material of claim 1.

5. A composite material comprising:

metallized particles contained in a polymer matrix with additives for increasing at least one of the ohmic, electrical and magnetic losses uniformly present in the polymer or on the particles, wherein the polymer matrix has a conductivity of from 10^-2 to 10⁴ ohm^-1 cm^-1.

6. A composite material comprising:

metallized particles contained in a polymer matrix with additives for increasing at least one of the ohmic, electrical and magnetic losses uniformly present in the polymer or on the particles, wherein the additives for increasing the ohmic, dielectric and/or magnetic losses are applied to the particles in a layer having a thickness of from 0.01 to 10 μ

m.

7. A composite material as claimed in claim 6, wherein the additive layer consists of organic pigments or of a semi-conducting inorganic material and has a conductivity of from 10°

to 10⁴ ohm^-1 cm^-1.

10. A composite material comprising:

metallized particles contained in a polymer matrix with additives for increasing at least one of the ohmic, electrical and magnetic losses uniformly present in the polymer or on the particles, wherein unmetallized regions are present on the particles and wherein the metallized regions are separated by intervals of from 0.01 to 10 μ

m.