Polymer composition and a power cable comprising the polymer composition

Patent metadata

Field	Value
Publication number	US-9595374-B2
Application number	US-201113883271-A
Country	US
Kind code	B2
Filing date	Nov 1, 2011
Priority date	Nov 3, 2010
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

The invention relates to a use of a polymer composition for producing an insulation layer of an AC power cable with and to an AC cable surrounded by at least an insulating layer comprising said polymer composition.

First claim

What is claimed is:

1. An alternating current (AC) power cable, comprising a conductor surrounded by at least an inner semiconductive layer comprising a first semiconductive composition, an insulation layer comprising a polymer composition, an outer semiconductive layer comprising a second semiconductive composition and,
wherein the polymer composition of the insulation layer comprises a polyolefin and a crosslinking agent, wherein the polyolefin is an unsaturated LDPE polymer, which is selected from the group consisting of an unsaturated LDPE homopolymer and an unsaturated LDPE copolymer of ethylene with one or more comonomer(s), and
wherein the polymer composition of the insulation layer has a dielectric loss expressed as tan δ (50 Hz) of 12.0 ×10 −4 or less, when measured at 25 kV/mm and 130° C. according to “Test for Tan δ measurements on 10 kV cables” as described in the description part under “Determination methods”; and
wherein the polyolefin is obtainable by a high pressure process comprising:
(a) compressing one or more monomer(s) under pressure in a compressor, using a compressor lubricant for lubrication,
(b) polymerizing a monomer optionally together with one or more comonomer(s) in a polymerization zone, and
(c) separating the obtained polyolefin from the unreacted products and recovering the separated polyolefin in a recovery zone,
wherein the compressor lubricant comprises a mineral oil.

2. The cable according to claim 1 , wherein the polymer composition of the insulation layer has a dielectric loss expressed as tan δ (50 Hz) of 11.0×10 −4 or less, when measured at 25 kV/mm and 130° C. according to “Test for Tan δmeasurements on 10 kV cables” as described in the description part under “Determination methods”.

3. The cable according to claim 1 , wherein the polymer composition of the insulation layer has a dielectric loss expressed as tan δ (50 Hz) of 0.01 −10.0×10 −4 , when measured at 25 kV/mm and 130° C. according to “Test for Tan δ measurements on 10 kV cables” as described in the description part under “Determination methods”.

4. The cable according to claim 1 , wherein the compressor lubricant comprises a white oil as the mineral oil and is suitable for production of polymers for food or medical industry.

5. The alternating current power cable according to claim 4 , wherein the white oil comprises paraffinic hydrocarbons.

6. The alternating current power cable according to claim 4 , wherein the white oil meets at least one of the following requirements:
a) the white oil has a viscosity of at least 8.5×10 −6 m 2 /s at 100° C.;
b) the white oil contains 5% per weight or less of hydrocarbons having less than 25 carbon atoms; and
c) the white oil contains hydrocarbons having an average molecular weight of 480 or more.

7. The cable according to claim 1 , wherein the mineral oil is a white mineral oil which meets the requirements given for white mineral oil in European Directive 2002/72/EC of 6 Aug. 2002, Annex V, for plastics used in food contact.

8. The cable according to claim 1 , wherein the crosslinking agent is peroxide.

9. The cable according to claim 1 , wherein the polyolefin is an unsaturated LDPE homopolymer or an unsaturated LDPE copolymer of ethylene with at least one polyunsaturated comonomer.

10. The cable according to claim 9 , wherein the polyolefin is an unsaturated LDPE copolymer of ethylene with at least one polyunsaturated comonomer and one or more other comonomer(s).

11. The cable according to claim 1 , wherein each of the inner and outer semiconductive composition comprises independently a conductive filler.

12. The cable according to claim 1 , wherein the cable comprises a jacketing layer comprising a jacketing composition.

13. The cable according to claim 1 , wherein at least the polymer composition of the insulation layer is crosslinked in the presence of said crosslinking agent.

14. The cable according to claim 1 , wherein at least the first semiconductive composition of the inner semiconductive layer and the polymer composition of the insulation layer are crosslinked.

15. The cable according to claim 1 , which is a MV, HV or EHV AC power cable.

16. A process for producing an alternating current (AC) power cable according to claim 1 , wherein the process comprises:
applying on a conductor an inner semiconductive layer comprising a first semiconductive composition, an insulation layer comprising a polymer composition, an outer semiconductive layer comprising a second semiconductive composition.

17. The process according to claim 16 , further comprising:
applying a jacketing layer comprising a jacketing composition on the conductor.

18. The alternating current power cable according to claim 1 , wherein the conductor is further surrounded by a jacketing layer comprising a jacketing composition.

19. The alternating current power cable according to claim 1 , wherein the mineral oil is a by-product in distillation of petroleum to produce gasoline and other petroleum based products from crude oil.

20. The alternating current power cable according to claim 1 , wherein the polyolefin is an unsaturated LDPE copolymer of ethylene with one or more comonomer(s).

Assignees

• Nilsson Ulf
• Smedberg Annika
• Campus Alfred
• Borealis Ag

Inventors

• Nilsson Ulf
• Smedberg Annika
• Campus Alfred

Classifications

• C08K5/14

  Peroxides · CPC title

• C08J3/24

  Crosslinking, e.g. vulcanising, of macromolecules (mechanical aspects B29C35/00; crosslinking agents C08K) · CPC title

• C08K5/01

  Hydrocarbons {(C08K5/0091 takes precedence)} · CPC title

• C08K3/04 Primary

  Carbon · CPC title

• H01B3/441

  from alkenes · CPC title