Patent US4474676A successfully refreshed from Google Patents.
US4474676A
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Electromagnetic interference shielding material
Assignee: TDK Corp
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Filing: 1983-08-12
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Granted: 1984-10-02
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Expires: 2003-08-12
Abstract
Abstract The present invention relates to an electromagnetic interference shielding material used for shielding radios and the like from electromagnetic waves emitted from a computer or the like. In the prior art, a zinc flame-sprayed shielding material is applied on the housing of a computer or the like to shield it from electromagnetic waves. The present invention provides an electromagnetic interference shielding material having an improved durability and shield effectiveness (SE) and comprising a ferromagnetic amorphous alloy having a conductivity of 10 2 Ω -1 ·cm -1 or more and a permeability of 100 or more at 1 kHz.
Inventors
- 👤 Ken Ishino
- 👤 Yasuo Hashimoto
- 👤 Yoshikazu Narumiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:33
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/0083; C; C08; C08K; C08K3/00; C08K3/02; C08K3/08; C08K3/10; H05K9/009
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
52 words
An electromagnetic interference shielding material, characterized in that a ferromagnetic amorphous alloy having a conductivity of 10 2 Ω -1 ·cm -1 or more and a permeability of 100 or more at 1 kHz is incorporated into a polymeric organic substance in the form of short pieces, short fibers, flakes, or grains.
Claim 2
Dependent Claim
52 words
An electromagnetic interference shielding material, characterized in that a ferromagnetic amorphous alloy having a conductivity of 10 2 Ω -1 ·cm -1 or more and a permeability of 100 or more at 1 kHz is incorporated into a polymeric organic substance in the form of short pieces, short fibers, flakes, or grains.
Claim 3
Dependent Claim
21 words
An electromagnetic interference shielding material, characterized in that said ferromagnetic amorphous alloy has an aspect ratio of from 1 to 20,000.
Claim 4
Dependent Claim
21 words
An electromagnetic interference shielding material, characterized in that said ferromagnetic amorphous alloy has an aspect ratio of from 1 to 20,000.
Claim 5
Dependent Claim
28 words
An electromagnetic interference shielding material according to claim 1, wherein the volume ratio of said ferromagnetic amorphous alloy to electromagnetic interference shielding material is from 0.04:0.96 to 0.65:0.35.
Claim 6
Dependent Claim
29 words
An electromagnetic interference shielding material according to claim 1, wherein said ferromagnetic amorphous alloy is in the form of short fibers having a length of 20 mm or less.
Claim 7
Dependent Claim
33 words
An electromagnetic interference shielding material according to claim 1, wherein said ferromagnetic amorphous alloy is in the form of flakes, the largest side of said flakes being 1 mm or less in size.
References Cited (Backward Citations)
US2283925A
Cited
US3668176A
Cited
US3800158A
Cited
US4308155A
Cited
US4331285A
Cited
US4431979A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |