KR20190016667A - Insulation composition for high voltage cable and cable having an insulating layer formed from the same - Google Patents

Abstract

The present invention relates to an insulation composition for a high-voltage cable and a cable comprising an insulation layer formed therefrom and, more specifically, to an insulation composition which satisfies properties such as high heat resistance, high flexibility, and high insulation resistance required for a high-voltage cable for electric vehicles, and in which properties such as strength, abrasion resistance, and oil resistance in conflict with the same are excellent, and to a cable comprising an insulation layer formed therefrom. In addition, the insulation composition for a high-voltage cable comprises: a base resin; and an additive.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an insulating composition for a high-voltage cable, and a cable including the insulating layer formed therefrom.

The present invention relates to an insulation composition for a high voltage cable and a cable comprising the insulation layer formed therefrom. Specifically, the present invention relates to an insulating composition which satisfies high heat resistance, high flexibility, high insulation resistance characteristics and the like required in a high voltage cable for an electric vehicle and which is also inferior in properties such as strength, abrasion resistance and oil resistance, To a cable comprising an insulating layer formed thereon.

High-voltage cables for electric vehicles correspond to 600 ~ 1,000V class at 150 ℃ and there are various standard products according to the cross-sectional area of conductors.

Conventional high voltage cable insulators for electric vehicles have a nominal cross-sectional area exceeding 6 SQ for use in applications. Flexibility is important for easy installation in a vehicle having a limited volume. In order to secure such flexibility, vinyl acetate (EVA) resin having a high content of VA or a polyolefin elastomer (POE) having a low melting point (Tm). However, the properties such as strength, abrasion resistance, and oil resistance may be significantly deteriorated.

On the other hand, the insulator composition of conventional high-voltage cables for electric vehicles satisfies ISO 6722 and LV216, which are not evaluated for rigidity such as strength and abrasion resistance for products exceeding 6 SQ as an international standard, but 6 SQ , JASO D624, which requires high strength and abrasion resistance, is not satisfied.

Accordingly, it is an object of the present invention to provide an insulating composition which satisfies the high heat resistance, high flexibility, and high insulation resistance characteristics required in a high voltage cable for an electric vehicle, and which has characteristics such as strength, abrasion resistance and oil resistance, There is an urgent need for a cable to be included.

An object of the present invention is to provide an insulation composition that satisfies high heat resistance, high flexibility, high insulation resistance characteristics and the like required in a high voltage cable for an electric vehicle and an insulation layer formed therefrom.

It is another object of the present invention to provide a cable including an insulating composition excellent in characteristics such as strength, abrasion resistance and oil resistance required in a high voltage cable for an electric vehicle and an insulating layer formed from the insulating composition.

In order to solve the above problems,

An insulating composition for a high-voltage cable, which comprises a base resin and an additive, wherein the base resin is a blend of a copolymer resin of an ethylene monomer and a polar monomer, a polypropylene resin, a polyolefin elastomer and a grafted polyolefin resin And the gel fraction of the insulating layer formed by crosslinking of the insulating composition is 83 to 87%.

Here, the content of the copolymer resin of the ethylene monomer and the polar monomer is 5 to 20 parts by weight, the content of the polypropylene resin is 7 to 25 parts by weight, the content of the polyolefin elastomer is 40 to 100 parts by weight, Wherein the content of the maleic anhydride-grafted polyolefin resin is 5 to 18 parts by weight.

The content of the polar monomer is 20 to 40% by weight based on the total weight of the copolymer resin of the ethylene monomer and the polar monomer, and the melting point (Tm) of the copolymer resin is 50 to 70 ° C. An insulation composition for a high voltage cable is provided.

Furthermore, the polar monomers include at least one selected from the group consisting of vinyl acetate (VA), methyl acrylate (MA), ethyl acrylate (EA) and butyl acrylate (BA) ≪ / RTI >

On the other hand, the polypropylene resin has a melting point (Tm) of 138 to 144 캜 and a specific gravity of 0.860 to 0.890.

Here, the polypropylene resin is characterized by comprising a heterophasic resin in which a propylene copolymer is dispersed in a polypropylene matrix.

The polypropylene matrix also includes a propylene random copolymer, and the propylene copolymer dispersed in the polypropylene matrix is 60 to 90 wt% based on the total weight of the heterophasic resin. Thereby providing an insulating composition.

The polyolefin elastomer has a melting point (Tm) of 90 to 105 ° C and a specific gravity of 0.890 to 0.910.

On the other hand, the polyolefin resin in which the maleic anhydride is grafted has a melting point (Tm) of 120 to 125 ° C and a specific gravity of 0.925 to 0.935.

Here, an insulation composition for a high-voltage cable is provided, wherein the polyolefin-based resin includes a linear low-density polyethylene resin (LLDPE).

On the other hand, the additive includes an insulating composition for a high-voltage cable, which comprises at least one additive selected from the group consisting of a flame retardant, a crosslinking aid, an antioxidant and a lubricant.

Here, the flame retardant includes magnesium hydroxide or aluminum hydroxide, and the content of the flame retardant is 80 to 105 parts by weight based on 100 parts by weight of the base resin.

The crosslinking assistant may further comprise a crosslinking assistant, wherein the crosslinking assistant comprises 2 to 5 parts by weight, based on 100 parts by weight of the base resin, of an organic polyfunctional organic monomer to be irradiated with the base resin. .

On the other hand, And an insulation layer surrounding the conductor and formed from the insulation composition.

The insulating composition for a high-voltage cable according to the present invention includes a combination of specific resins and is precisely controlled in the gel fraction, so that a high heat resistance, a high flexibility, a high insulation resistance characteristic, and the like which are in conflict with these strengths, abrasion resistance, And exhibits excellent effects that can also improve the characteristics.

1 schematically illustrates a cross-sectional structure of one embodiment of a high voltage cable comprising an insulating layer formed from an insulating composition according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification.

The present invention relates to an insulating composition for a high voltage cable of an electric vehicle.

The insulating composition according to the present invention includes a base resin, a flame retardant dispersed in the resin, a crosslinking assistant and the like, and may further contain other additives such as an antioxidant and a lubricant.

Here, the base resin may include a blending resin of a copolymer resin of an ethylene monomer and a polar monomer, a polypropylene (PP) resin, a polyolefin elastomer (POE), and a grafted polyolefin resin grafted with maleic anhydride.

The insulation composition for a high-voltage cable according to the present invention adopts a combination of the above-described specific resins as a base resin and controls the gel fraction of the insulation layer formed by crosslinking of the composition to 83 to 87% , High flexibility, high insulation characteristics, and the like, and the strength, abrasion resistance and oil resistance which are in conflict with each other can be simultaneously improved.

Specifically, when the gel fraction is less than 83%, the strength, abrasion resistance, oil resistance, etc. of the insulating layer formed from the composition may be greatly reduced, on the assumption that the combination of the specific resins described above is adopted as the base resin, If the gel fraction is more than 87%, the flexibility, heat resistance, insulation properties, etc. of the insulating layer formed from the composition may be greatly reduced.

Here, the copolymer resin of the ethylene monomer and the polar monomer functions to improve the flexibility of the insulating composition, and the polar monomer may include vinyl acetate (VA), methyl acrylate (MA), ethyl acrylate (EA), butyl Acrylate (BA) and the like, preferably vinyl acetate (VA).

The polar monomer may be contained in an amount of 20 to 40% by weight based on the total weight of the copolymer resin, the melting point (Tm) of the copolymer resin may be 50 to 70 ° C, , And the content of the copolymer resin may be 5 to 20 parts by weight, preferably 10 to 17 parts by weight.

When the content of the polar monomer is less than 20% by weight or the content of the copolymer resin is less than 5% by weight, the oil resistance and flexibility of the insulating composition may be significantly lowered, while the content of the polar monomer is more than 40% If the content of the copolymer resin is more than 20 parts by weight, the strength, abrasion resistance and the like of the insulating composition may be greatly lowered. If the melting point (Tm) of the copolymer resin is less than 50 ° C, the heat resistance of the insulating composition may be lowered .

The polypropylene (PP) resin has a high melting point (Tm) of its own and is excellent in insulation resistance characteristics, oil resistance and the like, and can include a propylene homopolymer and / or a propylene copolymer. The propylene homopolymer has a total weight of monomers Means a polypropylene formed by polymerization of at least 99% by weight, preferably at least 99.5% by weight, of propylene.

The propylene copolymer is obtained by copolymerizing propylene with ethylene or an? -Olefin having 4 to 12 carbon atoms, such as 1-butene, 1-pentene, 4-methyl-1-pentene, Dodecene, and combinations thereof, and the like, preferably a copolymer with ethylene. This is because copolymerization of propylene and ethylene shows a hard and flexible property.

The propylene copolymer may include a random propylene copolymer and / or a block propylene copolymer, and the random propylene copolymer refers to a propylene copolymer in which propylene monomer and other olefin monomers are alternately arranged.

In particular, the polypropylene (PP) resin may comprise a heterophasic resin in which the propylene copolymer is dispersed in the polypropylene matrix. Here, the polypropylene matrix may include a propylene homopolymer and / or a propylene copolymer, preferably a propylene random copolymer, and more preferably a propylene random copolymer.

In addition, the propylene copolymer (hereinafter referred to as 'dispersed propylene copolymer') dispersed in the polypropylene matrix is substantially amorphous. Here, the amorphous propylene copolymer means that the propylene copolymer has a residual crystallinity with a melting enthalpy of less than 10 J / g. The dispersed propylene copolymer is selected from the group consisting of ethylene and C _4-8 alpha-olefins such as 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, And may include one or more comonomers.

The dispersed propylene copolymer may be 60 to 90 wt%, preferably 65 to 80 wt%, based on the total weight of the heterophasic resin. If the content of the dispersed propylene copolymer is less than 60% by weight, flexibility, flexibility and cold resistance of the formed insulating layer may be insufficient, while if it exceeds 90% by weight, the heat resistance and strength of the insulating layer may be insufficient can do.

The dispersed propylene copolymer may be a propylene-ethylene rubber (PER) or propylene-ethylene diene rubber (EPDM) containing 20 to 50 wt%, preferably 30 to 40 wt% of ethylene monomer based on the total weight of monomers . If the content of the ethylene monomer is less than 20% by weight, the formed insulation layer may have excellent flexibility and bending property but may be insufficient in cold resistance and the like. On the other hand, when the content of the ethylene monomer exceeds 50% by weight, the insulation layer has excellent cold resistance, heat resistance and mechanical strength But flexibility and the like can be reduced.

In the present invention, the particle size of the dispersed propylene copolymer may be 1 占 퐉 or less, preferably 0.9 占 퐉 or less, and more preferably 0.8 占 퐉 or less. Such a particle size of the dispersed propylene copolymer ensures uniform dispersion of the dispersed propylene copolymer in the polypropylene matrix and improves the strength, abrasion resistance and the like of the insulating layer containing the dispersed propylene copolymer. In addition, the particle size improves the likelihood of stopping already formed cracks or cracks while reducing the risk of fracture initiated by the particles.

The polypropylene (PP) resin may have a melting point (Tm) of 138 to 144 DEG C and a specific gravity of 0.860 to 0.890. When the melting point of the polypropylene (PP) resin is less than 138 占 폚 or the specific gravity is less than 0.860, the insulating properties, mechanical properties such as abrasion resistance and heat resistance of the insulating composition may be insufficient. On the other hand, The flexibility of the insulating composition may be greatly reduced.

The content of the polypropylene (PP) resin may be 7 to 25 parts by weight, preferably 10 to 20 parts by weight, based on 100 parts by weight of the base resin, and the content of the polypropylene (PP) resin is less than 7 parts by weight The insulating properties of the insulating composition, mechanical properties such as abrasion resistance, heat resistance and the like may be insufficient, while if it exceeds 25 parts by weight, the flexibility of the insulating composition of the insulating composition may be greatly deteriorated.

The polyolefin elastomer (POE) may further improve the insulation resistance and oil resistance of the insulating composition, have a melting point (Tm) of 90 to 105 ° C and a specific gravity of 0.890 to 0.910. When the melting point of the polyolefin elastomer (POE) is less than 90 占 폚 or the specific gravity is less than 0.890, the insulating properties and mechanical properties such as abrasion resistance, heat resistance and oil resistance of the insulating composition may be insufficient. On the other hand, If it exceeds 0.910, the flexibility, cold resistance and the like of the insulating composition may be largely lowered.

The amount of the polyolefin elastomer (POE) may be 40 to 70 parts by weight, preferably 50 to 65 parts by weight based on 100 parts by weight of the base resin. When the amount of the polyolefin elastomer (POE) is less than 40 parts by weight, The oil resistance and the like of the insulating composition may be insufficient. On the other hand, if it exceeds 70 parts by weight, the flexibility, cold resistance and the like of the insulating composition may be greatly lowered.

The polyolefin-based resin in which the maleic anhydride is grafted improves the compatibility of the base resin with the inorganic flame retardant and improves mechanical properties such as flame retardancy and strength of the insulating composition. In the polyolefin-based resin in which the maleic anhydride is grafted, the polyolefin-based resin may include linear low-density polyethylene (LLDPE). The linear low density polyethylene grafted with maleic anhydride may have a melting point (Tm) of less than 130 占 폚, for example, 120 to 125 占 폚, and a specific gravity of less than 0.948, for example, 0.925 to 0.935.

The maleic anhydride-grafted polyolefin-based resin may be 5 to 18 parts by weight based on 100 parts by weight of the base resin. When the content of the maleic anhydride-grafted polyolefin-based resin is less than 5 parts by weight, The flame retardancy, flexibility and cold resistance of the composition may be deteriorated. On the other hand, when the content is more than 18 parts by weight, the insulation resistance, mechanical properties such as abrasion resistance, heat resistance and the like of the insulating composition may be greatly lowered.

The flame retardant dispersed in the base resin can improve the flame retardancy of the insulating composition and can include, for example, metal hydroxides such as magnesium hydroxide and aluminum hydroxide. In order to improve dispersibility in the base resin, It can be surface-treated with a hydrophobic substance such as silane.

The content of the flame retardant may be 80 to 105 parts by weight, preferably 85 to 95 parts by weight, based on 100 parts by weight of the base resin. When the content of the flame retardant is less than 80 parts by weight, the flame retardancy of the insulating composition may be insufficient, while when it is more than 105 parts by weight, mechanical properties such as insulation resistance and abrasion resistance of the insulating composition may be greatly deteriorated.

The crosslinking aid may be added for irradiation crosslinking of the base resin, and may include, for example, a polyfunctional organic monomer, and its content may be 2 to 5 parts by weight based on 100 parts by weight of the base resin.

If the amount of the crosslinking aid is less than 2 parts by weight, the crosslinking degree of the base resin may be insufficient and mechanical properties such as insulation resistance, abrasion resistance, heat resistance and the like of the insulating composition may be greatly deteriorated. On the other hand, The flexibility and cold resistance of the insulating composition may be deteriorated.

As the other additives, the antioxidant may be further added to secure the long-term heat resistance of the insulating composition, and the lubricant may be further added to improve the compatibility of the base resin and other additives.

1 schematically illustrates a cross-sectional structure of one embodiment of a high voltage cable comprising an insulating layer formed from an insulating composition according to the present invention.

1, a cable according to the present invention may include a conductor 10 and an insulation layer 20 surrounding the conductor 10 and formed from the insulation composition described above. The conductor 10 is preferably a copper strand formed by connecting fine wires of copper to secure the flexibility of the cable. The nominal cross-sectional area of the conductor 10 and the thickness of the insulating layer 20 are determined by the cable standard and the use And may be appropriately selected by a person skilled in the art of cable technology according to the present invention.

[Example]

1. Manufacturing Example

The insulating composition was prepared by mixing the composition shown in Table 1 at 150 ° C for 30 minutes using a 3L kneader, and then an insulating layer was formed using a single screw extruder (Φ: 45 mm) did. In the preparation of the cable specimen, the conductor was coated with 6SQ peristaltic cable and the irradiation crosslinking was carried out after extrusion when forming the insulating layer from the insulating composition. The unit of the content shown in Table 1 below is parts by weight, and some of the commonly added additives are omitted.

Example Comparative Example One 2 3 One 2 3 4 5 6 7 8 Resin 1 10 16 15 10 29 15 16 7 10 10 Resin 2 17 12 17 17 15 35 12 15 20 17 17 Resin 3 62 64 56 62 45 37 64 75 36 62 62 Resin 4 11 8 12 11 13 8 10 12 11 11 Resin 5 11 Resin 6 25 Flame retardant 88 93 91 88 90 90 120 90 90 88 88 Crosslinking auxiliary 3 3 3 3 3 3 3 3 3 One 5

Resin 1: ethylene vinyl acetate (EVA) (melting point: 56 占 폚; vinyl acetate: 33% by weight)

Resin 2: polypropylene (PP) resin (melting point: 141 占 폚; specific gravity: 0.872)

Resin 3: polyolefin elastomer (POE) (melting point: 98 占 폚; specific gravity: 0.900)

- Resin 4: linear low density polyethylene having a maleic anhydride grafted (melting point: 122 占 폚; specific gravity: 0.930)

Resin 5: High-density polyethylene having a maleic anhydride grafted (melting point: 134 占 폚; specific gravity: 0.954)

Resin 6: ethylene propylene diene rubber (EPDM) (Specific gravity: 0.880, Mooney viscosity (ML1 + 4 @ 125 ° C): 21 to 29)

- Flame retardant: Magnesium hydroxide coated with vinyl silane (BET specific surface area: 4.0 to 6.0 m 2 / g)

- Crosslinking aid: trimethylolpropane trimethacrylate (TMPTMA)

2. Property evaluation

1) Evaluation of tensile strength and elongation at room temperature

According to the IEC 60811-1-1 standard, the conductors were removed from each of the cable specimens of Examples and Comparative Examples, and tensile strength was measured at a rate of 200 mm / min using a UTM tester to measure the tensile strength and elongation at breakage . The measured tensile strength should exceed 15 MPa and the elongation measured is 400%

2) Abrasion resistance evaluation

Examples and Comparative Examples According to JASO D624 Standard Sandpaper abrasion resistance evaluation was performed with a load of 1,350 g for each of the cable specimens. The movement distance of the conductor of the cable specimen and the aluminum indicator tape of the sandpaper to each other Respectively.

3) Evaluation of oil resistance

According to the ISO 6722 standard, each of the cable specimens of the examples and comparative examples was immersed in a beaker containing gasoline and diesel, respectively, and allowed to stand at room temperature for 20 hours. After taking out, the cable outer diameter was measured after 30 minutes. If the outer diameter after immersion is 15% (gasoline) or 5% (diesel), respectively, as compared with the pre-siege outer diameter, it is below the standard.

4) Evaluation of insulation resistance

The insulation resistance was measured for each of the cable specimens of the examples and comparative examples in accordance with the ISO 6722 standard. The insulation resistance measured shall exceed 10 ¹² Ω · ㎜.

5) Flexibility evaluation

According to the JASO D624 standard, each of the cable specimens was bent into a C-shape and mounted on a UTM equipment. The cable specimens were compressed at a rate of 100 mm / min until the radius of curvature of the cable specimen reached 40 cm from 80 cm The maximum value of the force to be measured was measured. The measured value should be 10 N or less.

6) Evaluation of heat resistance

The long and short term heat resistance of each of the cable specimens of Examples and Comparative Examples was evaluated in accordance with the ISO 6722 standard. The long term heat resistance was evaluated as follows. After the specimen was stood at 150 DEG C for 3,000 hours and then subjected to a voltage of 1 kV The short-term heat resistance shall not cause cracking during the low-temperature bending test in the -25 ° C chamber after staying at 175 ° C for 240 hours.

The physical property evaluation results are shown in Table 2 below.

Reference value Example Comparative Example One 2 3 One 2 3 4 5 6 7 8 The tensile strength > 15 MPa 15.5 16.8 16.3 16.3 17.7 13.1 15.9 14.2 13.6 14.8 17.2 Elongation rate > 400% 450 437 472 363 322 325 483 511 511 567 371 Abrasion resistance mm 1972 1821 2031 2031 1181 1577 1605 1785 1096 1721 2137 of mine
U
castle Gasoline ≤15% 9.0 9.8 9.5 10.2 10.7 10.5 9.7 13.2 11.9 13.4 10.7 diesel ≤5% 1.1 1.2 0.5 1.3 4.3 5.7 2.5 3.7 2.9 4.2 2.3 Insulation Resistance > 10 ¹² Ωmm 2.37E + 14 2.85E + 14 2.61E + 14 2.93E + 14 8.85E + 11 4.59E + 14 1.74E + 14 7.21E + 14 5.35E + 14 2.42E + 14 3.14E + 14 flexibility ≪ 5.8 6.3 6.7 6.4 5.5 12.3 8.7 11.5 6.5 4.8 6.7
Heat resistance
No Crack No Crack No Crack No Crack No Crack No Crack No Crack No Crack Crack No Crack No Crack No Crack Gel fraction 83 ~ 87 84.9 85.7 85.5 84.8 88.2 85.7 86.1 84.5 85.8 75.5 89.1

As shown in Table 2, in the cable specimen of Comparative Example 1, high-density polyethylene in which maleic anhydride having a high melting point and a high ratio was grafted was used as Resin 5, The test specimens were found to have improved elongation, abrasion resistance, insulation resistance, and under-standard, while the resin 3 content was lower than the reference level. In the cable specimen of Comparative Example 3, the content of Resin 2 was higher than the standard, , Elongation and flexibility were found to be lower or below the standards, the cable specimens of Comparative Example 4 were found to have lower abrasion resistance than the flame retardant content, and the cable specimens of Comparative Example 5 had a content of resin 3 exceeding the standard The tensile strength and the flexibility were found to be lower or lower than the standard, and the cable specimen of Comparative Example 6 had flexibility , The tensile strength and the abrasion resistance were found to be lower or lower than the reference value, and the cable specimen of Comparative Example 7 had a low level of flexibility and elongation characteristics due to the insufficient amount of the crosslinking aid, And the abrasion resistance was found to be lower or lower than the reference value. In the cable specimen of Comparative Example 8, the content of the crosslinking aid exceeded the standard and it was confirmed that the elongation percentage or the like was lower or lower than the reference.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. . It is therefore to be understood that the modified embodiments are included in the technical scope of the present invention if they basically include elements of the claims of the present invention.

10: conductor 20: insulating layer

Claims (14)

An insulation composition for a high-voltage cable,
A base resin and an additive,
Wherein the base resin comprises a blending resin of a copolymer resin of an ethylene monomer and a polar monomer, a polypropylene resin, a polyolefin elastomer and a maleic anhydride grafted polyolefin resin,
Wherein an insulating layer formed by crosslinking of the insulating composition has a gel fraction of 83 to 87%. The method according to claim 1,
The content of the copolymer resin of the ethylene monomer and the polar monomer is 5 to 20 parts by weight, the content of the polypropylene resin is 7 to 25 parts by weight, the content of the polyolefin elastomer is 40 to 70 parts by weight And the content of the maleic anhydride-grafted polyolefin-based resin is 5 to 18 parts by weight. 3. The method according to claim 1 or 2,
Wherein the content of the polar monomer is 20 to 40% by weight based on the total weight of the copolymer resin of the ethylene monomer and the polar monomer, and the melting point (Tm) of the copolymer resin is 50 to 70 ° C. / RTI > The method of claim 3,
Characterized in that said polar monomer comprises at least one member selected from the group consisting of vinyl acetate (VA), methyl acrylate (MA), ethyl acrylate (EA) and butyl acrylate (BA) Composition. 3. The method according to claim 1 or 2,
Wherein the polypropylene resin has a melting point (Tm) of 138 to 144 占 폚 and a specific gravity of 0.860 to 0.890. 6. The method of claim 5,
Wherein the polypropylene resin comprises a heterophasic resin in which a propylene copolymer is dispersed in a polypropylene matrix. The method according to claim 6,
Wherein the polypropylene matrix comprises a propylene random copolymer and the propylene copolymer dispersed in the polypropylene matrix is 60 to 90 weight percent based on the total weight of the heterophasic resin. . 3. The method according to claim 1 or 2,
Wherein the polyolefin elastomer has a melting point (Tm) of 90 to 105 DEG C and a specific gravity of 0.890 to 0.910. 3. The method according to claim 1 or 2,
Wherein the maleic anhydride-grafted polyolefin-based resin has a melting point (Tm) of 120 to 125 占 폚 and a specific gravity of 0.925 to 0.935. 10. The method of claim 9,
Wherein the polyolefin-based resin comprises a linear low-density polyethylene resin (LLDPE). 3. The method according to claim 1 or 2,
Wherein the additive comprises at least one additive selected from the group consisting of a flame retardant, a crosslinking aid, an antioxidant and a lubricant. 12. The method of claim 11,
Wherein the flame retardant comprises magnesium hydroxide or aluminum hydroxide, and the content of the flame retardant is 80 to 105 parts by weight based on 100 parts by weight of the base resin. 12. The method of claim 11,
Wherein the cross-linking assistant comprises an organic polyfunctional organic monomer in which the base resin is irradiated, and the amount of the cross-linking aid is 2 to 5 parts by weight based on 100 parts by weight of the base resin. Conductor; And
A cable wrapped around said conductor and comprising an insulating layer formed from the insulating composition of claim 1 or 2.

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