Insulation composition having low dielectric constant, and cable including insulation layer formed therefrom

Patent metadata

Field	Value
Publication number	US-10438716-B2
Application number	US-201716084777-A
Country	US
Kind code	B2
Filing date	Feb 27, 2017
Priority date	Mar 15, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

Provided is an insulation composition having a low dielectric constant and a cable including an insulation layer formed of the insulation composition. More particularly, the present invention relates to an insulation composition for reducing a space charge to increase superimposed impulse breakdown strength when impulse voltages overlap during application of a direct-current (DC) voltage, having a low dielectric constant, and improving impulse breakdown strength, and a cable including an insulation layer formed of the insulation composition.

First claim

The invention claimed is:

1. An insulation composition comprising:
a base resin; and
a metal or non-metal oxide having a size of 1 to 100 nm included in the base resin,
wherein the metal or the non-metal oxide comprises at least one selected from the group consisting of magnesium oxide (MgO), zinc oxide (ZnO), silicon oxide (SiO2), aluminum oxide (Al2O3) and titanium oxide (TiO2), and a content of the metal or non-metal oxide is 0.01% by weight or more and less than 1% by weight, based on a total weight of the insulation composition,
wherein a dielectric constant of the insulation composition is less than that of the base resin,
wherein a dielectric constant reduction rate (%) defined by Equation 1 below is 1% or more,
dielectric constant reduction (%)=[( a−b )/ a ]*100,  [Equation 1]

wherein a represents the dielectric constant of the base resin, and b represents the dielectric constant of the insulation composition.

2. The insulation composition of claim 1 , wherein the dielectric constant reduction rate (%) is 2% or more.

3. The insulation composition of claim 1 , wherein an electric field distortion factor (%) defined by Equation 2 below is less than 150%,
electric field distortion factor (%)=α/β,  [Equation 2]

wherein α represents an electric field (kV/mm) applied to an insulation layer sample formed of the insulation composition, and β represents an electric field (kV/mm) distorted due to a distribution of space charges in the insulation composition.

4. The insulation composition of claim 3 , wherein the electric field distortion factor (%) is 120% or less.

5. The insulation composition of claim 1 , wherein the metal or the non-metal oxide has a cubic shape.

6. The insulation composition of claim 1 , wherein the metal or the non-metal oxide is surface modified to be hydrophobic.

7. The insulation composition of claim 1 , wherein the base resin is an olefin homopolymer or copolymer resin.

8. The insulation composition of claim 1 , further comprising 0.5 to 2% by weight of a crosslinking agent, 0.1 to 1% by weight of an antioxidant, and 0.1 to 1% by weight of a scorch inhibitor, based on a total weight of the insulating composition.

9. A cable comprising:
a conductor;
an inner semiconducting layer covering the conductor;
an insulation layer covering the inner semiconducting layer, and formed of the insulation composition of claim 1 ;
an outer semiconducting layer covering the insulation layer; and
a sheath layer covering the outer semiconducting layer.

Assignees

• Ls Cable & System Ltd

Inventors

• Nam Jin Ho
• Lee Won Suck
• Ryu Ik Hyun
• Yang Yi Seul
• Jung Hyun Jung
• Lee Tae Hyun

Classifications

• C08K2201/005

  Additives being defined by their particle size in general · CPC title

• C08K9/06

  with silicon-containing compounds · CPC title

• C08K3/22

  of metals · CPC title

• C08K3/041

  Carbon nanotubes · CPC title

• C08K3/042

  Graphene or derivatives, e.g. graphene oxides · CPC title