EP0008235A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Semi-conductive polymeric compositions suitable for use in electrical heating devices; flexible heating cables made by using said compositions and method for making the like cables
Assignee: Eaton Corp
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Filing: 1979-08-10
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Granted: —
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Expires: 1999-08-10
Abstract
Abstract Disclosed are improved melt processable, self-temperature regulating, irradiation cross-linkable, electrically semi-conductive polymeric compositions (5) which in conjunction with annealing at a temperature at or above their melt point temperatures subsequent to their having been radiation cross-linked provide for improved self-temperature regulating electrical heating devices (1) including flexible electrical heating cables. Heating cables (1) made in accordance with the invention comprise two or more elongate substantially parallel spaced-apart electrical conductors that are electrically interconnected by means of extruded forms of the compositions which have been annealed at a, temperature at or above their melt point temperatures prior and subsequent to their having been cross-linked by irradiation. The compositions of the invention have an amount of electrically conductive particles, such as carbon black, dispersed therein, that is controlled within the range of 17% to 25% by weight to the total weight of the compositions.
Inventors
- 👤 Richard W. Farkas
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 04:06
CPC Classifications
H; H01; H01B; H01B13/00; H01B13/06; H01B13/14; H01B1/00; H01B1/20; H01B1/24; H01C; H01C7/00; H01C7/02; H01C7/027; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/146; H05B3/40; H05B3/54; H05B3/56; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
123 words
A melt-processable, radiation cross-linkable, electrically semi-conductive composition having a positive temperature coefficient of electrical resistance and adapted for use in a self-temperature regulating electrical heating device, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said composition being characterised in that it contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to promote the electrical characteristics desired thereof at temperature that is at or above its melt point temperature subsequent to its having been melt processed and cross-linked by radiation.
Claim 2
Dependent Claim
123 words
A melt-processable, radiation cross-linkable, electrically semi-conductive composition having a positive temperature coefficient of electrical resistance and adapted for use in a self-temperature regulating electrical heating device, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said composition being characterised in that it contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to promote the electrical characteristics desired thereof at temperature that is at or above its melt point temperature subsequent to its having been melt processed and cross-linked by radiation.
Claim 3
Dependent Claim
19 words
A composition as claimed in Claim 1, characterised in that the composition is cross-linked by means of electron radiation.
Claim 4
Dependent Claim
137 words
A self-temperature regulating electrical heating device having heating means comprising a melt processed, radiation cross-linked, electrically semi-conductive composition (5) having a positive temperature coefficient of electrical resistance and electrically interconnecting two or more spaced-apart electrical conductors (2, 9), said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said device being characterised in that the composition contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to provide the electrical characteristics desired thereof at a temperature that is at or above its melt point temperature subsequent to its having been melt processed and cross-linked by irradiation.
Claim 5
Dependent Claim
137 words
A self-temperature regulating electrical heating device having heating means comprising a melt processed, radiation cross-linked, electrically semi-conductive composition (5) having a positive temperature coefficient of electrical resistance and electrically interconnecting two or more spaced-apart electrical conductors (2, 9), said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said device being characterised in that the composition contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to provide the electrical characteristics desired thereof at a temperature that is at or above its melt point temperature subsequent to its having been melt processed and cross-linked by irradiation.
Claim 6
Dependent Claim
22 words
An electrical heating device as claimed in Claim 3, characterised in that the semi-conductive composition is cross-linked by means of electron radiation.
Claim 7
Dependent Claim
146 words
_ A flexible self-temperature regulating electrical heating cable having heating means comprising two or more substantially parallel spaced apart elongate electrical conductors (2, 9) electrically interconnected by means of an extruded, radiation cross-linked, electrically semi-conductive composition (5) having a positive temperature coefficient of electrical resistance, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said cable being characterised in that said composition contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to promote the electrical characteristics desired thereof at a temperature that is at or above its melt point temperature prior and subsequent to its having been cross-linked by radiation following its extrusion.
Claim 8
Dependent Claim
146 words
_ A flexible self-temperature regulating electrical heating cable having heating means comprising two or more substantially parallel spaced apart elongate electrical conductors (2, 9) electrically interconnected by means of an extruded, radiation cross-linked, electrically semi-conductive composition (5) having a positive temperature coefficient of electrical resistance, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof, said cable being characterised in that said composition contains an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, and said composition having been annealed for a period of time sufficient to promote the electrical characteristics desired thereof at a temperature that is at or above its melt point temperature prior and subsequent to its having been cross-linked by radiation following its extrusion.
Claim 9
Dependent Claim
25 words
A heating cable as claimed in Claim 5, characterised in that the electrical conductive particles dispersed in the semi-conductive composition are particles of carbon black.
Claim 10
Dependent Claim
21 words
A heating cable as claimed in Claim 5, characterised in that the semi-conductive composition is cross-linked by means of electron radiation.
Claim 11
Dependent Claim
57 words
A heating cable as claimed in Claim 5, characterised by a generally tubular shaped form having an electrical conductor (2) disposed along the central longitudinal axis thereof and one or more electrical conductors (8) disposed about the outer surface of the composition and which are electrically interconnected with the central conductor by means of the semi-conductive composition.
Claim 12
Dependent Claim
23 words
A heating cable as claimed in Claim 5, characterised by a protective jacket (6) disposed in encompassing relationship about the composition and conductors.
Claim 13
Independent Claim
276 words
A method of making a flexible self-temperature regulating electrical heating cable comprising two or more substantially parallel spaced-apart elongate electrical conductors electrically interconnected by means of an extruded, radiation cross-linked, electrically semi-conductive composition having a positive temperature coefficient of electrical resistance, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof and containing an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, the method being characterised by the steps of: (a) extruding the cross-linkable composition about two or more substantially parallel spaced apart elongate electrical conductors in such a manner as to provide a form having a cross-sectional shape thereof transverse to its longitudinal axis that is suitable for use as a heating cable with the semi-conductive composition electrically interconnecting the spaced apart conductors; (b) disposing a radiation penetrable shape retaining covering in encompassing relationship about the extruded composition and conductors having a melt point temperature thereof which is higher than the temperature chosen to anneal the composition such that the covering prevents or minimizes distortion of the composition during the annealing process; (c) annealing the covered cross-linkable semi-conductive composition at a temperature that is at or above its melt point temperature for a period of time sufficient to promote the electrical characteristics desired thereof; (d) cross-linking the annealed semi-conductive composition by means of radiation; and (e) annealing the radiation cross-linked composition at a temperature that is at or above its melt point temperature for a period of time sufficient to promote the electrical characteristics desired thereof.
Claim 14
Independent Claim
276 words
A method of making a flexible self-temperature regulating electrical heating cable comprising two or more substantially parallel spaced-apart elongate electrical conductors electrically interconnected by means of an extruded, radiation cross-linked, electrically semi-conductive composition having a positive temperature coefficient of electrical resistance, said composition containing one or more polymeric components therein to provide sufficient crystallinity to promote the self-temperature heat regulating characteristics thereof and containing an amount of electrically conductive particles dispersed therein that is controlled within the range of 17% to 25% by weight to the total weight of the composition, the method being characterised by the steps of: (a) extruding the cross-linkable composition about two or more substantially parallel spaced apart elongate electrical conductors in such a manner as to provide a form having a cross-sectional shape thereof transverse to its longitudinal axis that is suitable for use as a heating cable with the semi-conductive composition electrically interconnecting the spaced apart conductors; (b) disposing a radiation penetrable shape retaining covering in encompassing relationship about the extruded composition and conductors having a melt point temperature thereof which is higher than the temperature chosen to anneal the composition such that the covering prevents or minimizes distortion of the composition during the annealing process; (c) annealing the covered cross-linkable semi-conductive composition at a temperature that is at or above its melt point temperature for a period of time sufficient to promote the electrical characteristics desired thereof; (d) cross-linking the annealed semi-conductive composition by means of radiation; and (e) annealing the radiation cross-linked composition at a temperature that is at or above its melt point temperature for a period of time sufficient to promote the electrical characteristics desired thereof.
Claim 15
Dependent Claim
62 words
The method of claim 10 characterised in that the semi-conductive composition (5) is extruded to form a generally tubular shape with an electrical conductor disposed along the central longitudinal axis thereof and one or more radiation penetrable electrical conductors are disposed about the outer surface of the composition and are electrically inter-connected with the central conductor by means of the semi-conductive composition.
Claim 16
Dependent Claim
42 words
The method of claim 11 characterised in that the one or more electrical conductors disposed about the outer surface of the semi-conductive composition provide the shape retaining covering (6) required to prevent or minimize distortion of the composition during the annealing process.
Claim 17
Dependent Claim
18 words
The method of claim 10 characterised in that the shape retaining covering (6) is an extruded protective jacket.
Claim 18
Dependent Claim
17 words
The method of claim 13, characterised in that the jacket is cross-linked during the step of radiation.
Claim 19
Dependent Claim
13 words
The method of claim 10 characterised in that the radiation is electron radiation.
References Cited (Backward Citations)
No citation records indexed.
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