Cable with improved electrical properties

Patent metadata

Field	Value
Publication number	US-10679769-B2
Application number	US-201716312400-A
Country	US
Kind code	B2
Filing date	Jun 20, 2017
Priority date	Jun 21, 2016
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A cable comprising a conductor surrounded by at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, wherein the insulation layer is not crosslinked or is cross-linked and comprises at least 90 wt % of a polymer composition, said polymer composition comprising: (I) 95.5 to 99.9 wt % of an LDPE; and (II) 0.1 to 4.5 wt % of an HDPE having a density of at least 940 kg/m3.

First claim

The invention claimed is:

1. A cable comprising one or more conductors surrounded by at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, wherein the insulation layer is not crosslinked or is cross-linked and comprises at least 90 wt % of a polymer composition, said polymer composition comprising:
(I) 95.5 to 99.9 wt % of an LDPE; and
(II) 0.1 to 4.5 wt % of an HDPE having a density of at least 940 kg/m 3 .

2. The cable of claim 1 , wherein the cable is a power cable.

3. The cable of claim 2 , wherein the power cable is a direct current (DC) power cable, operating at or capable of operating at 320 kV or more.

4. The cable of claim 1 , wherein the LDPE has an MFR 2 (2.16 kg, 190° C.) of 0.1 to 10 g/10 min.

5. The cable of claim 4 , wherein the LDPE has an MFR 2 (2.16 kg, 190° C.) of 0.1 to 5.0 g/10 min.

6. The cable of claim 1 , wherein the LDPE is a homopolymer.

7. The cable of claim 1 , wherein the HDPE has a density of 945 to 965 kg/m 3 .

8. The cable of claim 1 , wherein the LDPE has a density of 920 to 932 kg/m 3 .

9. The cable of claim 1 , wherein the HDPE has a MFR 2 (2.16 kg, 190° C.) of 0.1-40 g/10 min.

10. The cable of claim 1 , wherein the polymer composition of the insulation layer has a conductivity of 1.5 fS/m or less when measured according to DC conductivity method as described under “Determination Method A”.

11. The cable of claim 1 , wherein the polymer composition of the insulation layer has a conductivity of 3.5×10 −17 S/cm or less when measured according to DC conductivity method as described under “Determination Methods B”.

12. The cable of claim 1 , wherein the polymer composition comprises 1.0 to 3.0 wt % HDPE.

13. The cable of claim 1 , wherein the insulation layer is crosslinked and the HDPE is unimodal.

14. The cable of claim 1 , wherein the HDPE is a single site produced HDPE.

15. The cable of claim 1 , wherein the insulation layer comprises 99 wt % or more of the polymer composition.

16. A process for producing a cable comprising:
applying on one or more conductors, an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, wherein the insulation layer comprises at least 90 wt % of a polymer composition as defined in claim 1 and is optionally cross-linked.

17. A cable comprising one or more conductors surrounded by at least an inner semiconductive layer, an insulation layer and an outer semiconductive layer, in that order, wherein the insulation layer is not cross-linked and comprises at least 90 wt % of a polymer composition, said polymer composition comprising:
(I) 95.5 to 99.9 wt % of an LDPE; and
(II) 0.1 to 4.5 wt % of a multimodal HDPE having a density of at least 940 kg/m 3 .

Assignees

• Borealis Ag

Inventors

• Hagstrand Per-Ola
• Gkourmpis Thomas
• Gitsas Antonios
• Englund Villgot
• Nilsson Ulf
• Andersson Mattias
• Hynynen Jonna
• Müller Christian

Classifications

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08L23/083

  with aliphatic polyenes, i.e. containing two or more carbon-to-carbon double bonds · CPC title

• C08L2207/062

  HDPE · CPC title

• C08L2207/066

  LDPE (radical process) · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title