US4957612A — Electrodes for use in electrochemical processes

Claim 1

Independent Claim 215 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which (i) is composed of a first conductive material having a first resistivity at 23°C., and (ii) does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material which is a conductive polymer and which has a second resistivity at 23° C., the second resistivity being at least 1200 ohm.cm and being higher than the first resistivity, (iii) does not provide any part of the electrochemically active surface of the electrode, and (iv) has a transverse resistance of at least 1 ohm.meter; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is a conductive polymer and which has a third resistivity of 23° C., the third resistivity being 0.01 to 300 ohm.cm, and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 2

Dependent Claim 215 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which (i) is composed of a first conductive material having a first resistivity at 23°C., and (ii) does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material which is a conductive polymer and which has a second resistivity at 23° C., the second resistivity being at least 1200 ohm.cm and being higher than the first resistivity, (iii) does not provide any part of the electrochemically active surface of the electrode, and (iv) has a transverse resistance of at least 1 ohm.meter; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is a conductive polymer and which has a third resistivity of 23° C., the third resistivity being 0.01 to 300 ohm.cm, and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 3

Dependent Claim 14 words

An article according to claim 1 wherein the first conductive material is a metal.

Claim 4

Dependent Claim 53 words

An article according to claim 1 wherein the first conductive material is a metal, the second conductive material in a conductive polymer having a resistivity at 23° C. of at least 1200 ohm.cm and the third conductive material is a conductive polymer having a resistivity at 23° C. of 0.1 to 50 ohm.cm.

Claim 5

Dependent Claim 26 words

An article according to claim 1 wherein the second resistivity is at least 100 times the third resistivity and at least 10,000 times the first resistivity.

Claim 6

Dependent Claim 43 words

An article according to claim 1 wherein the second material has a current density at 2 volts in 3% sodium chloride solution which is less than 0.1 times the current density of the third material at 2 volts in 3% sodium chloride solution.

Claim 7

Dependent Claim 204 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which (i) is composed of a metal having a first resistivity at 23° C., and (ii) does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material which is a conductive polymer and which has a second resistivity at 23° C., the second resistivity being higher than the first resistivity, (iii) does not provide any part of the electrochemically active surface of the electrode, and (iv) has a transverse resistance of at least 1 ohm.meter; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is selected from graphite, mixtures of graphite and carbon, and dispersions of carbonaceous materials in thermoset resins, and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 8

Dependent Claim 204 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which (i) is composed of a metal having a first resistivity at 23° C., and (ii) does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material which is a conductive polymer and which has a second resistivity at 23° C., the second resistivity being higher than the first resistivity, (iii) does not provide any part of the electrochemically active surface of the electrode, and (iv) has a transverse resistance of at least 1 ohm.meter; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is selected from graphite, mixtures of graphite and carbon, and dispersions of carbonaceous materials in thermoset resins, and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 9

Dependent Claim 180 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which is composed of a first conductive material having a first resistivity at 23° C. and which does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material having a second resistivity at 23° C., and (iii) does not provide any part of the electrochemically active surface of the electrode; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is more electrochemically active than the second conductive material, and which has a third resistivity at 23° C., and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 10

Dependent Claim 180 words

An elongate article which is suitable for use as a distributed electrode in an electrochemical process and which comprises (a) an elongate core which is composed of a first conductive material having a first resistivity at 23° C. and which does not provide any part of the electrochemically active surface of the electrode; (b) an elongate intermediate element which (i) is secured to and electrically surrounds the core, (ii) is composed of a second conductive material having a second resistivity at 23° C., and (iii) does not provide any part of the electrochemically active surface of the electrode; and (c) at least one outer element which (i) is secured to and is in electrical contact with the core and the intermediate element so that all electrical paths between the core and the outer element pass through the intermediate element, (ii) is composed of a third conductive material which is more electrochemically active than the second conductive material, and which has a third resistivity at 23° C., and (iii) provides at least part of the electrochemically active surface of the electrode.

Claim 11

Dependent Claim 22 words

An article according to claim 2 wherein the first resistivity is less than the second resistivity and less than the third resistivity.

Claim 12

Dependent Claim 30 words

An article according to claim 7 wherein the third material is a conductive polymer and the second material is a conductive polymer having a resistivity of at least 25 ohm.cm.

Claim 13

Dependent Claim 21 words

An article according to claim 7 wherein the third material is a conductive polymer and the second material is a metal.

Claim 14

Dependent Claim 144 words

An elongate article which is suitable for use as a distributed anode in the cathodic protection of reinforcing bars embedded in concrete, and which comprises (1) a continuous elongate tape which is composed of a first conductive polymer having an elongation of at least 10% and a resistivity at 23° C. of 0.01 to 10 3 ohm.cm; and (2) a continuous elongate filamentous member which is at least partially embedded in the tape and which comprises (a) a continuous elongate metal core which has a resistance at 23° C. of less than 0.03 ohm/meter; and (b) a continuous elongate intermediate element which electrically surrounds the core and which is composed of a second conductive polymer having an elongation of at least 10% and a resistivity at 23° C. which is at least 2 times the resistivity at 23° C. of the first conductive polymer.

Claim 15

Dependent Claim 144 words

An elongate article which is suitable for use as a distributed anode in the cathodic protection of reinforcing bars embedded in concrete, and which comprises (1) a continuous elongate tape which is composed of a first conductive polymer having an elongation of at least 10% and a resistivity at 23° C. of 0.01 to 10 3 ohm.cm; and (2) a continuous elongate filamentous member which is at least partially embedded in the tape and which comprises (a) a continuous elongate metal core which has a resistance at 23° C. of less than 0.03 ohm/meter; and (b) a continuous elongate intermediate element which electrically surrounds the core and which is composed of a second conductive polymer having an elongation of at least 10% and a resistivity at 23° C. which is at least 2 times the resistivity at 23° C. of the first conductive polymer.

Claim 16

Dependent Claim 31 words

An article according to claim 11 which further comprises a carrier which is composed of an insulating material and which can be secured to a surface of a mass of concrete.

Claim 17

Dependent Claim 32 words

An article according to claim 12 wherein the carrier is in the form of a shallow trough with laterally extending side members comprising means for securing the carrier to a concrete surface.

Claim 18

Dependent Claim 47 words

An article according to claim 13 which comprises an elastically compressible member which lies between the elongate tape and the carrier and is such that when the carrier is secured to a concrete surface, the compressible member is compressed and urges the tape towards the concrete surface.

Claim 19

Dependent Claim 41 words

An article according to claim 12 which comprises a layer of a deformable electrically conductive material on the major surface of the tape which, when the carrier is secured to a surface of a mass of concrete, is nearer the concrete.

Claim 20

Dependent Claim 47 words

An article according to claim 11 wherein the first conductive polymer has a resistivity of 0.1 to 100 ohm.cm and the second conductive polymer has a resistivity which is at least 50 ohm.cm and at least 50 ohm.cm higher than the resistivity of the first conductive polymer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-09-17	1994-03-19	1994-09-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-09-17	1998-03-19	1998-09-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-09-17	2002-03-19	2002-09-18	$7700.00	Window Closed / Lapsed

Electrodes for use in electrochemical processes

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