US4379098A
Expired / Lapsed
US
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Electromagnetic radiation shielding composites and method of production thereof
Assignee: Transmet Corp
•
Filing: 1980-07-17
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Granted: 1983-04-05
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Expires: 2000-07-17
Abstract
Abstract A method is disclosed for the preparation of an electromagnetic shielding composite which exhibits high conductivity and low resistance. The method comprises applying an electrical potential difference across a composite comprised of an electrically conductive material dispersed within a matrix material to increase the conductivity of the composite. An electrical current of sufficient magnitude is then passed through the composite to further increase the conductivity of the composite while maintaining the electrical potential difference at a value which does not exceed the value of the electrical potential difference which was previously applied.
Inventors
- 👤 Anthony Gumienny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:55
CPC Classifications
H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/0083; B; B29; B29C; B29C70/00; B29C70/88; B29C70/882; B29C71/00; B29C71/0081; B29K; B29K2995/00; B29K2995/0003; B29K2995/0005; Y; Y10; Y10S; Y10S264/00; Y10S264/45
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
137 words
A method of preparing an electromagnetic shielding composite which exhibits high conductivity and low resistance comprising: providing a composite comprising an electrically conductive material dispersed within a matrix material; and applying an electrical potential difference across said composite of sufficient magnitude to increase the conductivity of the composite whereby an additional application of said electrical potential difference will not further increase the conductivity of the composite, and thereafter passing an electrical current through the composite of sufficient magnitude to further increase the conductivity of the composite while maintaining the electrical potential difference at a value which does not exceed the value of the electrical potential difference which was previously applied, said electrical current being of a value greater than the value of any current which previously passed through the composite during application of said electrical potential difference.
Claim 2
Independent Claim
137 words
A method of preparing an electromagnetic shielding composite which exhibits high conductivity and low resistance comprising: providing a composite comprising an electrically conductive material dispersed within a matrix material; and applying an electrical potential difference across said composite of sufficient magnitude to increase the conductivity of the composite whereby an additional application of said electrical potential difference will not further increase the conductivity of the composite, and thereafter passing an electrical current through the composite of sufficient magnitude to further increase the conductivity of the composite while maintaining the electrical potential difference at a value which does not exceed the value of the electrical potential difference which was previously applied, said electrical current being of a value greater than the value of any current which previously passed through the composite during application of said electrical potential difference.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the matrix material is selected from the group consisting of thermoplastic or thermosetting materials.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein the matrix material comprises a foamed material.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein the matrix material is a thermoplastic material.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein the matrix material is selected from the group consisting of polyethylene, polystyrene and polycarbonate.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein the electrically conductive material comprises carbon fibers.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein the electrically conductive material is selected from the group consisting of metallic solids and metallized non-conductive solids.
Claim 9
Dependent Claim
41 words
The method of claim 7 wherein the electrically conductive material comprises metallic solids which are comprised of a material selectd from the group consisting of copper, zinc, aluminum, silver, iron, nickel, gold, tungsten, niobium, carbon steel, stainless steel and mixtures thereof.
Claim 10
Dependent Claim
35 words
The method of claim 1 wherein the conductive material is dispersed within the matrix material in an amount ranging from about 5 to about 60 percent by weight based on the weight of the composite.
Claim 11
Dependent Claim
30 words
The method of claim 9 wherein the conductive material is present in an amount ranging from about 5 to 40 percent by weight based on the weight of the composite.
Claim 12
Dependent Claim
30 words
The method of claim 9 wherein the conductive material is present in a amount ranging from about 15 to 30 percent by weight based on the weight of the composite.
Claim 13
Dependent Claim
20 words
The method of claim 1 wherein the electrical potential difference which is applied ranges from about 500 to 15,000 volts.
Claim 14
Dependent Claim
24 words
The method of claim 1 wherein the electrical current which is passed through the composite ranges from about 100 microamps to about 100 milliamps.
Claim 15
Dependent Claim
45 words
The method of claim 1 wherein a first and at least one additional electrical current of differing magnitudes are passed through the composite and wherein the magnitude of said at least one additional electrical current is greater than the magnitude of said first electrical current.
Claim 16
Independent Claim
204 words
A method of preparing an electromagnetic radiation shielding composite which exhibits high conductivity and low resistance comprising: providing a composite comprising an electrically conductive material dispersed within a matrix material; and applying an electrical potential difference across said composite such that a first and at least one additional electrical potential difference are applied across said composite, each said potential difference being greater than the potential difference which precedes it and each said additional potential difference which is applied being of such a value so as to increase the conductivity of said composite in comparison to that which said composite exhibits prior to applying said additional electrical potential difference, said electrical potential differences being applied a sufficient number of times and increased to such a value so that the conductivity of the composite no longer increases, thereafter passing an electrical current through the composite of sufficient magnitude to further increase the conductivity of the composite while maintaining the electrical potential difference at a value which does not exceed the value of the highest electrical potential difference previously applied, said electrical current being of a value greater than the value of any current which previously passed through the composite during application of said electrical potential difference.
Claim 17
Independent Claim
204 words
A method of preparing an electromagnetic radiation shielding composite which exhibits high conductivity and low resistance comprising: providing a composite comprising an electrically conductive material dispersed within a matrix material; and applying an electrical potential difference across said composite such that a first and at least one additional electrical potential difference are applied across said composite, each said potential difference being greater than the potential difference which precedes it and each said additional potential difference which is applied being of such a value so as to increase the conductivity of said composite in comparison to that which said composite exhibits prior to applying said additional electrical potential difference, said electrical potential differences being applied a sufficient number of times and increased to such a value so that the conductivity of the composite no longer increases, thereafter passing an electrical current through the composite of sufficient magnitude to further increase the conductivity of the composite while maintaining the electrical potential difference at a value which does not exceed the value of the highest electrical potential difference previously applied, said electrical current being of a value greater than the value of any current which previously passed through the composite during application of said electrical potential difference.
Claim 18
Dependent Claim
20 words
The method of claim 15 wherein the matrix material is selected from the group consisting of thermoplastic or thermosetting materials.
Claim 19
Dependent Claim
13 words
The method of claim 15 wherein the matrix material comprises a foamed material.
Claim 20
Dependent Claim
12 words
The method of claim 16 wherein the matrix material is thermoplastic material.
Claim 21
Dependent Claim
20 words
The method of claim 18 wherein the matrix material is selected from the group consisting of polyethylene, polystyrene and polycarbonate.
Claim 22
Dependent Claim
13 words
The method of claim 15 wherein the electrically conductive material comprises carbon fibers.
Claim 23
Dependent Claim
23 words
The method of claim 15 wherein the electrically conductive material is selected from the group consisting of metallic solids and metallized non-conductive solids.
Claim 24
Dependent Claim
41 words
The method of claim 21 wherein the electrically conductive material comprises metallic solids which are comprised of a material selected from the group consisting of copper, zinc, aluminum, silver, iron, nickel, gold, tungsten, niobium, carbon steel, stainless steel and mixtures thereof.
Claim 25
Dependent Claim
34 words
The method of claim 15 wherein the conductive material is dispersed whithin the matrix material in an amount ranging from about 5 to 60 percent by weight based on the weight of the composite.
Claim 26
Dependent Claim
30 words
The method of claim 23 wherein the conductive material is present in an amount ranging from about 5 to 40 percent by weight based on the weight of the composite.
Claim 27
Dependent Claim
30 words
The method of claim 23 wherein the conductive material is present in an amount ranging from about 15 to 30 percent by weight based on the weight of the composite.
Claim 28
Dependent Claim
20 words
The method of claim 15 wherein the electrical potential difference which is applied ranges from about 500 to 15,000 volts.
Claim 29
Dependent Claim
18 words
The method of claim 15 wherein from two to ten electrical potential differences of differing magnitudes are applied.
Claim 30
Dependent Claim
18 words
The method of claim 27 wherein from three to six electrical potential differences of differing magnitudes are applied.
Claim 31
Dependent Claim
34 words
The method of claim 15 wherein the value of said at least one additional electrical potential difference exceeds the value of the electrical potential difference which precedes it by about 25 to 300 percent.
Claim 32
Dependent Claim
19 words
The method of claim 15 wherein the values of the electrical potential differences which are applied are increased intermittently.
Claim 33
Dependent Claim
19 words
The method of claim 15 wherein the values of the electrical potential differences which are applied are increased continuously.
Claim 34
Dependent Claim
45 words
The method of claim 15 wherein a first and at least one additional electrical current of differing magnitudes are passed through the composite and wherein the magnitude of said at least one additional electrical current is greater than the magnitude of said first electrical current.
Claim 35
Dependent Claim
24 words
The method of claim 15 wherein the electrical current which is passed through the composite ranges from about 100 microamps to about 100 milliamps.
Claim 36
Dependent Claim
30 words
The method of claim 3 wherein the foamed matrix material exhibits a density in excess of 70 percent of the density exhibited by said matrix material in an unfoamed state.
Claim 37
Dependent Claim
30 words
The method of claim 17 wherein the foamed matrix material exhibits a density in excess of 70 percent of the density exhibited by said matrix material in an unfoamed state.
Claim 38
Dependent Claim
45 words
The method of claim 1 wherein said electrical potential difference is of a magnitude such that the composite is not physically degraded by application thereof and the conductivity of the composite cannot be increased further by application of an electrical potential difference of greater magnitude.
Claim 39
Dependent Claim
49 words
The method of claim 15 wherein the highest electrical potential difference which is applied is of a magnitude such that the composite is not physically degraded by application thereof and the conductivity of the composite cannot be increased further by application of an electrical potential difference of greater magnitude.
Claim 40
Dependent Claim
36 words
The method of claim 1 wherein said electrical current is of sufficient magnitude such that it exceeds the magnitude of any electrical current previously passed through the composite during the application of said electrical potential difference.
Claim 41
Dependent Claim
42 words
The method of claim 15 wherein said electrical current is of sufficient magnitude such that it exceeds the magnitude of any electrical current previously passed through the composite during application of said first and said at least one additional electrical potential difference.
References Cited (Backward Citations)
US2321587A
Cited
US2406714A
Cited
US3194860A
Cited
US3393257A
Cited
US4216423A
Cited
US4243460A
Cited
US4227037A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |