US4388607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductive polymer compositions, and to devices comprising such compositions
Assignee: Raychem Corp
•
Filing: 1979-10-17
•
Granted: 1983-06-14
•
Expires: 1999-10-17
Abstract
Abstract Conductive polymer compositions which have improved voltage stability and which preferably exhibit PTC behavior. The compositions comprise a carbon black dispersed in a crystalline copolymer of an olefin and at least 10% by weight of an olefinically unsaturated comonomer containing a polar group. The carbon black has a particle size greater than 18 millimicrons, preferably greater than 30 millimicrons, a d-spacing greater than 360 and a surface area which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black. The carbon black is preferably present in amount at least 15% by weight of the composition. Particularly useful devices including such compositions are self-regulating heaters.
Inventors
- 👤 Lester T. Toy
- 👤 Wendell W. Moyer
- 👤 Bernard J. Lyons
- 👤 David A. Horsma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:31
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/02; H01C7/027; H01B; H01B1/00; H01B1/20; H01B1/24
Claims Analysis
Total Claims: 55
Claim 1
Independent Claim
229 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which exhibits PTC behavior with an R 14 value of at least 2.5 and which comprises (a) conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; subject to the proviso that when (i) said crystalline copolymer (b) has a melt index of more than 20 and (ii) 2L+5 log 10 R<45 where L is the content of carbon black in percent by weight based on the weight of the composition and R is the resistivity of the composition at 25° C. in ohm.cm., said composition has a gel fraction of at least 0.6.
Claim 2
Dependent Claim
229 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which exhibits PTC behavior with an R 14 value of at least 2.5 and which comprises (a) conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; subject to the proviso that when (i) said crystalline copolymer (b) has a melt index of more than 20 and (ii) 2L+5 log 10 R<45 where L is the content of carbon black in percent by weight based on the weight of the composition and R is the resistivity of the composition at 25° C. in ohm.cm., said composition has a gel fraction of at least 0.6.
Claim 3
Dependent Claim
18 words
A device according to claim 1 wherein said carbon black has a particle size greater than 30 millimicrons.
Claim 4
Dependent Claim
19 words
A device according to claim 1 wherein said carbon black has a particle size of at most 75 millimicrons.
Claim 5
Dependent Claim
17 words
A device according to claim 1 wherein said composition has a gel fraction of at least 0.6.
Claim 6
Dependent Claim
80 words
A device according to claim 1 wherein said composition also comprises (c) at least one crystalline polymer which is selected from polymers consisting essentially of units derived from at least one olefin, polymers comprising at least 50% by weight of --CH 2 CHCl-- units and polymers comprising at least 50% by weight of --CH 2 CF 2 -- units; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 7
Dependent Claim
21 words
A device according to claim 5 wherein said composition has a resistivity at 25° C. of 80 to 10 5 ohm.cm.
Claim 8
Dependent Claim
24 words
A device according to claim 6 which comprises a pair of laminar electrodes having a said element in the form of a lamina therebetween.
Claim 9
Dependent Claim
42 words
A device according to claim 7 which comprises (1) an elongate element of a said composition; (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 10
Dependent Claim
49 words
A device according to claim 1 wherein said composition also comprises (c) at least one crystalline polymer which consists essentially of units derived from at least one olefin; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 11
Dependent Claim
13 words
A device according to claim 9 wherein said crystalline polymer (c) is polyethylene.
Claim 12
Dependent Claim
29 words
A device according to claim 10 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate and vinyl acetate.
Claim 13
Dependent Claim
33 words
A device according to claim 9 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate, vinyl acetate, acrylic acid and methacrylic acid.
Claim 14
Dependent Claim
27 words
A device according to claim 1 wherein the copolymer (b) is a copolymer of ethylene and vinyl acetate and wherein the conductive polymer composition also comprises polyethylene.
Claim 15
Dependent Claim
48 words
A device according to claim 13 which is a self-limiting heater and which comprises (1) an elongate element of a said composition; (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 16
Dependent Claim
27 words
A device according to claim 1 wherein the copolymer (b) is a copolymer of ethylene and ethyl acrylate and wherein the conductive polymer composition also comprises polyethylene.
Claim 17
Dependent Claim
48 words
A device according to claim 15 which is a self-limiting heater and which comprises (1) an elongate element of a said composition; (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 18
Dependent Claim
180 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which has a gel fraction of at least 0.6 and which comprises (a) a conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; the content of carbon black in said composition being L% by weight and the resistivity of said composition at 25° C. being R ohm.cm, and R and L being such that 2L+5 log.sub.10 R>45.
Claim 19
Dependent Claim
180 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which has a gel fraction of at least 0.6 and which comprises (a) a conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; the content of carbon black in said composition being L% by weight and the resistivity of said composition at 25° C. being R ohm.cm, and R and L being such that 2L+5 log.sub.10 R>45.
Claim 20
Dependent Claim
18 words
A device according to claim 17 wherein said carbon black has a particle size greater than 30 millimicrons.
Claim 21
Dependent Claim
19 words
A device according to claim 17 wherein said carbon black has a particle size of at most 75 millimicrons.
Claim 22
Dependent Claim
79 words
A device according to claim 17 wherein said composition also comprises (c) at least one crystalline polymer which is selected from polymers consisting essentially of units derived from at least one olefin, polymers comprising at least 50% by weight of --CH 2 CHCl-- units and polymers comprising at least 50% by weight of --CH 2 CF 2 units; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 23
Dependent Claim
21 words
A device according to claim 20 wherein said composition has a resistivity at 25° C. of 80 to 10 5 ohm.cm.
Claim 24
Dependent Claim
24 words
A device according to claim 21 which comprises a pair of laminar electrodes having a said element in the form of a lamina therebetween.
Claim 25
Dependent Claim
48 words
A device according to claim 21 which is a self-limiting heater and which comprises (1) an elongate element of a said composition; (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 26
Dependent Claim
49 words
A device according to claim 17 wherein said composition also comprises (c) at least one crystalline polymer which consists essentially of units derived from at least one olefin; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 27
Dependent Claim
13 words
A device according to claim 24 wherein said crystalline polymer (c) is polyethylene.
Claim 28
Dependent Claim
29 words
A device according to claim 25 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate and vinyl acetate.
Claim 29
Dependent Claim
33 words
A device according to claim 24 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate, vinyl acetate, acrylic acid and methacrylic acid.
Claim 30
Dependent Claim
90 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which exhibits PTC behavior with an R 100 value at least 10 and which comprises (a) conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than
Claim 31
Dependent Claim
90 words
An electrical device comprising an element composed of a conductive polymer and at least two electrodes adapted to be connected to an external source of electrical power so as to cause an electrical current to pass through the element, said element being composed of a cross-linked conductive polymer composition which exhibits PTC behavior with an R 100 value at least 10 and which comprises (a) conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than
Claim 32
Dependent Claim
139 words
2S+e S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; subject to the proviso that when (i) said crystalline copolymer (b) has a melt index of more than 20 and (ii) 2L+5 log 10 R≦45, where L is the content of carbon black in percent by weight based on the weight of the composition and R is the resistivity of the composition at 25° C. in ohm.cm, said composition has a gel fraction of at least 0.6.
Claim 33
Dependent Claim
139 words
2S+e S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group; subject to the proviso that when (i) said crystalline copolymer (b) has a melt index of more than 20 and (ii) 2L+5 log 10 R≦45, where L is the content of carbon black in percent by weight based on the weight of the composition and R is the resistivity of the composition at 25° C. in ohm.cm, said composition has a gel fraction of at least 0.6.
Claim 34
Dependent Claim
18 words
A device according to claim 28 wherein said carbon black has a particle size greater than 30 millimicrons.
Claim 35
Dependent Claim
19 words
A device according to claim 28 wherein said carbon black has a particle size of at most 75 millimicrons.
Claim 36
Dependent Claim
17 words
A device according to claim 29 wherein said composition has a gel fraction of at least 0.6.
Claim 37
Dependent Claim
80 words
A device according to claim 27 wherein said composition also comprises (c) at least one crystalline polymer which is selected from polymers consisting essentially of units derived from at least one olefin, polymers comprising at least 50% by weight of --CH 2 CHCl-- units and polymers comprising at least 50% by weight of --CH 2 CF 2 -- units; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 38
Dependent Claim
21 words
A device according to claim 32 wherein said composition has a resistivity at 25° C. of 80 to 10 5 ohm.cm.
Claim 39
Dependent Claim
24 words
A device according to claim 33 which comprises a pair of laminar electrodes having a said element in the form of a lamina therebetween.
Claim 40
Dependent Claim
42 words
A device according to claim 33 which comprises (1) an elongate element of a said composition; (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 41
Dependent Claim
49 words
A device according to claim 28 wherein said composition also comprises (c) at least one crystalline polymer which consists essentially of units derived from at least one olefin; which has a softening point higher than said copolymer (b); and which serves as a matrix for the carbon-black-containing copolymer (b).
Claim 42
Dependent Claim
13 words
A device according to claim 36 wherein said crystalline polymer (c) is polyethylene.
Claim 43
Dependent Claim
29 words
A device according to claim 37 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate and vinyl acetate.
Claim 44
Dependent Claim
33 words
A device according to claim 36 wherein said crystalline copolymer (b) is a copolymer of ethylene and a polar comonomer selected from methyl acrylate, ethyl acrylate, vinyl acetate, acrylic acid and methacrylic acid.
Claim 45
Dependent Claim
197 words
A self-limiting heater which comprises (1) an elongate element composed of a cross-linked conductive polymer composition which has a gel fraction of at least 0.6, which exhibits PTC behavior, which has a resistivity at 25° C. of 80 to 50,000 ohm.cm, and which comprises (a) a conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group and (c) at least one crystalline polymer which consists essentially of units derived from at least one olefin and which has a softening point higher than said co-polymer (b); (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 46
Dependent Claim
197 words
A self-limiting heater which comprises (1) an elongate element composed of a cross-linked conductive polymer composition which has a gel fraction of at least 0.6, which exhibits PTC behavior, which has a resistivity at 25° C. of 80 to 50,000 ohm.cm, and which comprises (a) a conductive carbon black having a particle size greater than 18 millimicrons, a d-spacing greater than 360, and a surface area (A) which is less than 1.2S+e.sup.S/50 where S is the DBP absorption of the carbon black, said carbon black being present in amount at least 15% by weight of the composition and being dispersed in (b) at least one crystalline copolymer which consists essentially of units derived from at least one olefin and at least 10 weight %, based on the copolymer, of units derived from at least one olefinically unsaturated comonomer containing a polar group and (c) at least one crystalline polymer which consists essentially of units derived from at least one olefin and which has a softening point higher than said co-polymer (b); (2) at least two longitudinally extending electrodes embedded in said composition parallel to each other; and (3) an outer layer of a protective and insulating composition.
Claim 47
Dependent Claim
21 words
A heater according to claim 40 wherein the copolymer (b) is an ethylene/vinyl acetate copolymer and the polymer (c) is polyethylene.
Claim 48
Dependent Claim
17 words
A heater according to claim 41 wherein the copolymer (b) has a melt index less than 20.
Claim 49
Dependent Claim
17 words
A heater according to claim 41 wherein the copolymer (b) has a melt index less than 10.
Claim 50
Dependent Claim
21 words
A heater according to claim 40 wherein the copolymer (b) is an ethylene/ethyl acrylate copolymer and the polymer (c) is polyethylene.
Claim 51
Dependent Claim
17 words
A heater according to claim 44 wherein the copolymer (b) has a melt index less than 20.
Claim 52
Dependent Claim
17 words
A heater according to claim 44 wherein the copolymer (b) has a melt index less than 10.
Claim 53
Dependent Claim
14 words
A heater according to claim 40 wherein the carbon black is a furnace black.
Claim 54
Dependent Claim
14 words
A heater according to claim 40 wherein the carbon black is a thermal black.
Claim 55
Dependent Claim
14 words
A heater according to claim 40 wherein the carbon black is a channel black.
References Cited (Backward Citations)
US601424A
Cited
US790977A
Cited
GB931999A
Cited
DE1219674B
Cited
GB942789A
Cited
FR1332065A
Cited
US3243753A
Cited
US3567607A
Cited
US3591526A
Cited
US3673121A
Cited
FR2077021A5
Cited
US3689736A
Cited
US3793716A
Cited
US3861029A
Cited
US3914363A
Cited
FR2199172B1
Cited
US3849333A
Cited
FR2321751A1
Cited
US4017715A
Cited
US4188276A
Cited
US4304987A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |