Electrical element comprising a layer of a polymeric material having an electrical conductivity gradient

Patent metadata

Field	Value
Publication number	US-9697925-B2
Application number	US-201214345314-A
Country	US
Kind code	B2
Filing date	Sep 27, 2012
Priority date	Sep 28, 2011
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

The present invention related to an electrical element ( 100, 101, 102 ) including an electrically conductive element ( 3, 5, 10, 31, 32, 51 ), characterized in that the electrical element also includes a first layer ( 1 ) of a polymer material with electrical conductivity gradient obtained from a polymer composition including at least one polymer and conductive carbonaceous fillers.

First claim

The invention claimed is:

1. An electrical element comprising:
an electrically conductive element, wherein the electrical element has a first layerof a polymeric material having an electrical conductivity gradient, which material is obtained from a polymeric composition having at least one polymer and conductive carbon fillers and where said electrical conductivity of said polymeric material gradually varies in the thickness of the first layer.

2. The electrical element as claimed in claim 1 , wherein the electrical element has a second layer of an electrically insulating material, said first layer being positioned between the electrically conductive element and the second layer.

3. The electrical element as claimed in claim 2 , wherein the electrical conductivity at the surface of the first layer closest the electrically conductive element is higher than the electrical conductivity at the surface of the first layer closest the second layer.

4. The electrical element as claimed in claim 2 , wherein said electrical element has a fourth layer of a material identical to that of the first layer, and a fifth layer of a semiconductive material, said fourth layer being positioned between the second layer and the fifth layer.

5. The electrical element as claimed in claim 2 , the wherein second layer encircles the electrical conductor.

6. The electrical element as claimed in claim 1 , wherein the conductive carbon fillers are selected from the group consisting of carbon blacks, carbon fibers, graphites, graphenes, fullerenes, carbon nanotubes or one of their mixtures.

7. The electrical element as claimed in claim 1 , the carbon nanotubes are selected from the group consisting of single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes, or one of their mixtures.

8. The electrical element as claimed in claim 1 , wherein the electrical conductivity of the first layer is comprised between 1×10 3 S/m and 1×10 −18 S/m (limits inclusive).

9. The electrical element as claimed in claim 1 , wherein the polymeric composition of the first layer comprises at most 30% by weight conductive carbon fillers.

10. The electrical element as claimed in any one of claims 1 to 9 , the electrically conductive element is an electrical conductor.

11. The electrical element as claimed in claim 10 , wherein the electrical element is an electrical cable in which the electrically conductive element is the electrical conductor.

12. The electrical element as claimed in claim 1 , wherein the electrically conductive element is a third layer of a semiconductive material.

13. The electrical element as claimed in claim 12 , wherein the electrical element is an electrical cable in which the electrically conductive element is the third layer.

14. The electrical element as claimed in claim 12 , wherein the electrical element is an electrical cable joint in which the electrically conductive element is the third layer.

15. The electrical element as claimed in claim 12 , wherein the electrical element is an electrical cable terminal in which the electrically conductive element is the third layer.

16. A process for manufacturing a layer of a polymeric material having an electrical conductivity gradient, for an electrical element such as defined in claim 1 , said method comprising the steps of:
a heat treatment of a layer of a polymeric material obtained from a polymeric composition comprising at least one polymer and conductive carbon fillers, said layer having a thickness bounded by a first and a second surface, said treatment step being carried out by applying a first temperature T 1 to the first surface and a second temperature T 2 to the second surface, so as to form a temperature gradient in the thickness of said layer and to obtain said layer of a material having an electrical conductivity gradient.

17. The process as claimed in claim 16 , wherein at least one of the temperatures, T 1 or T 2 , is a temperature equal to or above the melting point Tf or glass transition temperature Tg of said polymer.

18. The manufacturing process as claimed in claim 16 , wherein when the electrical element is either one of an electrically conductive element of an electrical cable or a electrically conductive third layer, the electrical conductor of the electrical cable is used as a heat source to apply the temperature gradient.

19. The electrical element as claimed in claim 1 , wherein said electrically conductive element is an element different from said first layer.

Assignees

• Nexans

Inventors

• Allais Arnaud
• Fournier Jerome
• Kebbabi Lazhar
• Bayon Lorrene
• Combessis Anthony
• Flandin Lionel

Classifications

• F27D2019/0028

  Regulation · CPC title

• H02G15/184

  with devices for relieving electrical stress · CPC title

• Y10S977/783

  Organic host/matrix, e.g. lipid · CPC title

• F27D2019/0093

  Maintaining a temperature gradient · CPC title

• H02G15/068

  connected to the cable shield only (H02G15/072 takes precedence) · CPC title