US4505847A
Expired / Lapsed
US
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Electrically-conductive materials
Assignee: University of Strathclyde
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Filing: 1983-03-17
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Granted: 1985-03-19
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Expires: 2003-03-17
Abstract
Abstract Electrically-conductive materials comprising silicone rubber in combination with carbon particles in graphitic form incorporate a vegetable oil additive to provide enhanced physical and electrical resistance properties. Electrical resistivity for stress loadings below 500 grammes per square millimeter is less than 500 ohm-meters and for step changes in stress is of the order of 1K ohms-cm. A large number of vegetable oils provide these characteristics in the materials when the vegetable oils are present in the material in the range of 10-30% by volume. Carbon loading may be in the range 50-90% when measured in carbon grammes weight in relation to the milliliter content of the volume of silicone rubber and vegetable oil.
Inventors
- 👤 John Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:09
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/20; H01B1/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
An electrically-conductive material in which electrical resistivity is related to stress loading, which material comprises a homogeneous combination of a silicone rubber, graphitic carbon and a vegetable oil, the silicone rubber and vegetable oil together forming a unit volume of which the silicone rubber is present in the range 70-90% and the vegetable oil is present in the range 30-10%, the graphitic carbon being in particulate form and present in an amount of of grammes weight in the range 50-90% of the milliliter content of said unit volume, the arrangement being such that the material has an electrical resistivity not exceeding 500 ohm-meters for stress loadings not exceeding 500 gm/mm 2 the magnitude of resistivity change for a stress change of 500 gm/mm 2 being at least one ohm-meter.
Claim 2
Dependent Claim
129 words
An electrically-conductive material in which electrical resistivity is related to stress loading, which material comprises a homogeneous combination of a silicone rubber, graphitic carbon and a vegetable oil, the silicone rubber and vegetable oil together forming a unit volume of which the silicone rubber is present in the range 70-90% and the vegetable oil is present in the range 30-10%, the graphitic carbon being in particulate form and present in an amount of of grammes weight in the range 50-90% of the milliliter content of said unit volume, the arrangement being such that the material has an electrical resistivity not exceeding 500 ohm-meters for stress loadings not exceeding 500 gm/mm 2 the magnitude of resistivity change for a stress change of 500 gm/mm 2 being at least one ohm-meter.
Claim 3
Dependent Claim
38 words
A material as claimed in claim 1, wherein said silicone rubber comprises a silicone gum and a curing agent for said gum, said gum and curing agent being present in proportions by volume of 100 to 1 respectively.
Claim 4
Dependent Claim
21 words
A material as claimed in claim 2, wherein for stress loadings not exceeding 500 gm/mm 2 the stress/strain relationship is elastic.
Claim 5
Dependent Claim
20 words
A material as claimed in claim 1, wherein said silicone rubber comprises a silicone gum loaded with an inert filler.
Claim 6
Dependent Claim
30 words
A material as claimed in claim 1, wherein said vegetable oil is selected from the group of vegetable oils consisting of olive oil, coconut oil, palm oil and arachis oil.
Claim 7
Dependent Claim
24 words
A material as claimed in claim 1, wherein said graphitic carbon is in the form of particles having a size not exceeding 55 μm.
Claim 8
Dependent Claim
109 words
An electrically-conductive material in which electrical resistivity is related to stress loading, which material comprises a homogeneous combination of a silicone rubber, graphitic carbon and a vegetable oil, the silicone rubber and vegetable oil together forming a unit volume of which the silicone rubber is present in the range 70-90% and the vegetable oil is present in the range 30-10%, the graphitic carbon being in micron-sized particulate form present in an amount of grammes weight in the range 50-90% of the milliliter content of said unit volume, and wherein said vegetable oil includes at least one unsaturated fatty acid having a carbon chain length of not less than 16.
Claim 9
Dependent Claim
109 words
An electrically-conductive material in which electrical resistivity is related to stress loading, which material comprises a homogeneous combination of a silicone rubber, graphitic carbon and a vegetable oil, the silicone rubber and vegetable oil together forming a unit volume of which the silicone rubber is present in the range 70-90% and the vegetable oil is present in the range 30-10%, the graphitic carbon being in micron-sized particulate form present in an amount of grammes weight in the range 50-90% of the milliliter content of said unit volume, and wherein said vegetable oil includes at least one unsaturated fatty acid having a carbon chain length of not less than 16.
Claim 10
Dependent Claim
22 words
A material as claimed in claim 7, wherein said at least one unsaturated fatty acid has a carbon chain length of 18.
Claim 11
Dependent Claim
30 words
A material as claimed in claim 7, wherein said vegetable oil is selected from the group of vegetable oils consisting of olive oil, coconut oil, palm oil and arachis oil.
References Cited (Backward Citations)
US4051454A
Cited
US4145317A
Cited
US4382024A
Cited
US4387046A
Cited
US4273697A
Cited
US4433096A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-18 | 1988-09-17 | 1989-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-18 | 1992-09-17 | 1993-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-18 | 1996-09-17 | 1997-03-19 | $7700.00 | Window Closed / Lapsed |