Electric cable with improved temperature ageing resistance

Patent metadata

Field	Value
Publication number	US-11257607-B2
Application number	US-201916722761-A
Country	US
Kind code	B2
Filing date	Dec 20, 2019
Priority date	Dec 21, 2018
Publication date	Feb 22, 2022
Grant date	Feb 22, 2022

Abstract

An electric cable has at least one semi-conductive layer obtained from a polymer composition having at least one polypropylene-based thermoplastic polymer material, at least one first antioxidant and at least one metal deactivator.

First claim

The invention claimed is:

1. Electric cable comprising:
at least one elongated electrically conductive element; and
at least one semi-conductive layer surrounding said elongated electrically conductive element,
wherein the semi-conductive layer is obtained from a polymer composition comprising at least one polypropylene-based thermoplastic polymer material, at least one first antioxidant,
and at least one metal deactivator,
wherein the semi-conductive layer is a non-crosslinked layer,
wherein the polymer composition further comprises a dielectric liquid
wherein the polypropylene-based thermoplastic polymer material comprises an amount of less than 10% by weight of polar polymer(s), with respect to the total weight of the polypropylene-based thermoplastic polymer material.

2. Electric cable according to claim 1 , wherein the first antioxidant is selected from hindered phenols, aromatic amines, and nitrogen-containing aromatic heterocyclics.

3. Electric cable according to claim 1 , wherein the polymer composition comprises at least 0.3% by weight of the first antioxidant, based on the total weight of the polymer composition.

4. Electric cable according to claim 1 , wherein the metal deactivator is selected from nitrogen-containing aromatic heterocycles, and aromatic compounds comprising at least one function —NH—C(═O)—.

5. Electric cable according to claim 1 , wherein the polymer composition comprises at least 0.2% by weight of the metal deactivator, based on the total weight of the polymer composition.

6. Electric cable according to claim 1 , wherein the polymer composition comprises at least 6% by weight of conductive filler, based on the total weight of the polymer composition.

7. Electric cable according to claim 1 , wherein the polypropylene-based thermoplastic polymer material comprises a propylene copolymer P 1 .

8. Electric cable according to claim 7 , wherein the polypropylene-based thermoplastic polymer material comprises a random propylene copolymer or a heterophasic propylene copolymer, as propylene copolymer P 1 .

9. Electric cable according to claim 1 , wherein the polypropylene-based thermoplastic polymer material comprises a random propylene copolymer and a heterophasic propylene copolymer, or two different heterophasic propylene copolymers.

10. Electric cable according to claim 1 , wherein the polypropylene-based thermoplastic polymer material can further comprise an olefin homopolymer or copolymer P 2 .

11. Electric cable according to claim 1 , wherein the polypropylene-based thermoplastic polymer material comprises at least 50% by weight of propylene polymer(s), based on the total weight of the polypropylene-based thermoplastic polymer material.

12. Electric cable according to claim 1 , wherein the polymer composition further comprises a second antioxidant different from the first antioxidant.

13. Electric cable according to claim 12 , wherein the polymer composition comprises at least 0.2% by weight of the second antioxidant, based on the total weight of the polymer composition.

14. Electric cable according to claim 1 , wherein the semi-conductive layer has a reduction in tensile strength after temperature ageing of at most 40%.

15. Electric cable according to claim 1 , wherein the semi-conductive layer has a reduction in elongation at break after temperature ageing of at most 50%.

16. Electric cable according to claim 1 , wherein said electric cable further comprises an electrically insulating layer.

17. Electric cable according to claim 1 , wherein the dielectric liquid includes a mineral oil.

Assignees

• Nexans

Inventors

• Koelblin Christian
• Maugin Melek
• Perego Gabriele
• Alcaraz Valéry

Classifications

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• H01B7/292 Primary

  using material resistant to heat · CPC title

• C08K5/005

  Stabilisers against oxidation, heat, light, ozone · CPC title

• C08L23/14 Primary

  Copolymers of propene (C08L23/16 takes precedence) · CPC title

• H01B9/027

  composed of semi-conducting layers · CPC title