Corrosion protection method
First Claim
1. A method of cathodically protecting an elongate, electrically conductive substrate which is buried in soil, which method comprises establishing a potential difference between the substrate as cathode and a distributed elongate anode which is buried in the soil adjacent to the substrate and spaced apart from the substrate by soil, the anode comprising a flexible strip comprising(1) a continuous elongate flexible metal core which has a resistance at 23°
- C. of less than 0.03 ohm/meter; and
(2) an elongate element which(i) is in electrical contact with the core;
(ii) is composed of a conductive polymer having an elongation of at least 10% and a resistivity at 23°
of 0.1 to 103 ohm.cm;
(iii) provides substantially the whole of the electrochemically active surface of the flexible strip; and
(iv) is at least 500 microns thick.
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Accused Products
Abstract
Methods of preventing corrosion in which current flows between the to-be-protected substrate and a distributed electrode whose electrochemically active surface is provided by an element which is composed of a conductive polymer and which is at least 500 microns thick. In one embodiment, the electrode is a flexible strip comprising a highly conductive core, e.g. of copper, and a conductive polymer element surrounding the core. In another embodiment, the electrode is a conductive polymer layer which conforms to the surface of the substrate but is separated from it by a layer of insulation.
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Citations
15 Claims
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1. A method of cathodically protecting an elongate, electrically conductive substrate which is buried in soil, which method comprises establishing a potential difference between the substrate as cathode and a distributed elongate anode which is buried in the soil adjacent to the substrate and spaced apart from the substrate by soil, the anode comprising a flexible strip comprising
(1) a continuous elongate flexible metal core which has a resistance at 23° - C. of less than 0.03 ohm/meter; and
(2) an elongate element which (i) is in electrical contact with the core; (ii) is composed of a conductive polymer having an elongation of at least 10% and a resistivity at 23°
of 0.1 to 103 ohm.cm;(iii) provides substantially the whole of the electrochemically active surface of the flexible strip; and (iv) is at least 500 microns thick. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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11. A method according to claim 10 wherein the substrate is a metal pipe having a diameter D.
- C. of less than 0.03 ohm/meter; and
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12. A method of cathodically protecting metal reinforcing bars encased in a mass of concrete, which method comprises establishing a potential difference between the reinforcing bars as cathode and a distributed anode which lies within the mass of concrete adjacent to the reinforcing bars and spaced apart from the reinforcing bars by concrete, the anode comprising a flexible strip comprising
(1) a continuous elongate flexible metal core which has a resistance at 23° - C. of less than 0.03 ohm/meter; and
(2) an elongate element which (i) is in electrical contact with the core; (ii) is composed of a conductive polymer having an elongation of at least 10% and a resistivity at 23°
C. of 0.1 to 103 ohm.cm;(iii) provides substantially the whole of the electrochemically active outer surface of the flexible strip; and (iv) is at least 500 microns thick. - View Dependent Claims (13, 14, 15)
- C. of less than 0.03 ohm/meter; and
Specification
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- Resources
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Current AssigneeTyco Electronics Corporation (TE Connectivity Limited)
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Original AssigneeRaychem Corporation (TE Connectivity Limited)
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InventorsStewart, Ray F., Masia, Michael, Macknick, Albert B.
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Primary Examiner(s)TUNG, TA HSUNG
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Application NumberUS06/403,203Time in Patent Office950 DaysField of Search204/147, 204/148, 204/196, 204/197, 204/280, 204/294, 204/291US Class Current205/734CPC Class CodesC23F 13/02 cathodic; Selection of cond...F16L 58/00 Protection of pipes or pipe...
