Polymer composition for W and C application with advantageous electrical properties
View Patent ↗The invention relates to a use of a polymer composition with improved DC electrical properties in a power cable layer and to a cable surrounded by at least one layer comprising the polymer composition.
1. A direct current (DC) power 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 comprises a non-crosslinked polymer composition comprising an antioxidant and 95 to 100 wt % of a polyolefin,
wherein the polyolefin is the only polymer component of the insulation layer and the polyolefin is:
a high density polyethylene (HDPE) homopolymer having a density of 945 kg/m 3 or more; or
a HDPE copolymer of ethylene and one or more comonomers selected from the group consisting of butene, hexene, and octene, the HDPE copolymer having a density of 945 kg/m 3 or more;
wherein the polymer composition has an electrical conductivity of 90 fS/m or less;
wherein the insulation layer has a thickness of 2 mm or more;
wherein each of the inner semiconductive layer and the outer semiconductive layer independently comprise from 10 to 50 wt % carbon black; and
wherein the inner semiconductive layer and the outer semiconductive layer each independently have a thickness that is less than the thickness of the insulation layer.
2. The cable according to claim 1 , wherein the outer semiconductive layer comprises a non-crosslinked second semiconductive composition and the inner semiconductive layer comprises a non-crosslinked first semiconductive composition.
3. The cable according to claim 1 , wherein the polyolefin is a polyethylene polymerized in the presence of an olefin polymerization catalyst.
4. The cable according to claim 1 , wherein the polyolefin is multimodal with respect to molecular weight distribution.
5. The cable according to claim 1 , wherein the polymer composition comprises 100 wt % of the polyolefin.
6. A direct current (DC) power 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 comprises a non-crosslinked polymer composition comprising an antioxidant and 95 to 100 wt % of a polyolefin,
wherein the polyolefin is the only polymer component of the insulation layer and the polyolefin is:
a linear low density polyethylene (LLDPE) copolymer of ethylene and one or more comonomers selected from the group consisting of butene, hexene, and octene, the LLDPE copolymer having a density of from 909 to 930 kg/m 3 ;
wherein the polymer composition has an electrical conductivity of 90 fS/m or less;
wherein the insulation layer has a thickness of 2 mm or more;
wherein each of the inner semiconductive layer and the outer semiconductive layer independently comprise from 10 to 50 wt % carbon black; and
wherein the inner semiconductive layer and the outer semiconductive layer each independently have a thickness that is less than the thickness of the insulation layer.
7. The cable according to claim 6 , wherein the outer semiconductive layer comprises a non-crosslinked second semiconductive composition and the inner semiconductive layer comprises a non-crosslinked first semiconductive composition.
8. The cable according to claim 6 , wherein the polyolefin is a polyethylene polymerized in the presence of an olefin polymerization catalyst.
9. The cable according to claim 6 , wherein the polyolefin is multimodal with respect to molecular weight distribution.
10. The cable according to claim 6 , wherein the polymer composition comprises 100 wt % of the polyolefin.
11. A direct current (DC) power 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 comprises a non-crosslinked polymer composition comprising an antioxidant and 95 to 100 wt % of a polyolefin,
wherein the polyolefin is the only polymer components of the insulation layer and the polyolefin is:
a medium density polyethylene (MDPE) copolymer of ethylene and one or more comonomers selected from the group consisting of butene, hexene, and octene, the MDPE copolymer having a density of from 930 to 945 kg/m 3 ;
wherein the polymer composition has an electrical conductivity of 90 fS/m or less;
wherein the insulation layer has a thickness of 2 mm or more;
wherein each of the inner semiconductive layer and the outer semiconductive layer independently comprise from 10 to 50 wt % carbon black; and
wherein the inner semiconductive layer and the outer semiconductive layer has a thickness that is less than the thickness of the insulation layer.
12. The cable according to claim 11 , wherein the outer semiconductive layer comprises a non-crosslinked second semiconductive composition and the inner semiconductive layer comprises a non-crosslinked first semiconductive composition.
13. The cable according to claim 11 , wherein the polyolefin is a polyethylene polymerized in the presence of an olefin polymerization catalyst.
14. The cable according to claim 11 , wherein the polyolefin is multimodal with respect to molecular weight distribution.
15. The cable according to claim 11 , wherein the polymer composition comprises 100 wt % of the polyolefin.