KR20170082874A - Insulating composition having excellent fire resistance - Google Patents

Abstract

The present invention relates to an insulating composition having excellent flame retardancy. Specifically, the present invention relates to a non-halogenated polypropylene insulating composition for a cable, which satisfies the T3 grade (125 DEG C) of the ISO standard, and which satisfies the high flame retardancy required by the ISO standard and has excellent cold resistance and abrasion resistance Lt; / RTI >

Description

[0001] Insulating composition having excellent fire resistance [

The present invention relates to an insulating composition having excellent flame retardancy. Specifically, the present invention relates to a non-halogenated polypropylene insulating composition for a cable, which satisfies the T3 grade (125 DEG C) of the ISO standard, and which satisfies the high flame retardancy required by the ISO standard and has excellent cold resistance and abrasion resistance Lt; / RTI >

Automobile wires are classified into various categories according to the temperature class and material used, and there are various specifications for each manufacturer. There are movements to integrate these specifications, and the JASO standard and the ISO standard are representative of the widely used integrated standards in the world.

The JASO standard was enacted in Japan and adopted by some automobile manufacturers in Japan and Korea. Automobile manufacturers in Europe and North America have adopted the ISO standard. However, the tendency to follow the ISO standard worldwide is dominant, and it is required to hold the product according to the ISO standard for the overseas shipment of the product.

The ISO standard test method is similar to the JASO standard, but the criteria for some evaluation items are strict and the products conforming to the JASO standard do not satisfy some items according to the ISO standard.

The JASO D618 flame retardant test method is a test to determine whether to turn off the flame vertically after horizontally installing the wire with horizontal flame retardation. On the other hand, the flame retardant test method required by ISO 6722 is to test whether the wire is set up at 45 ° and the flame is lowered to 45 ° angle so that it is perpendicular to the wire sample and ignites and turns itself off.

Generally, in the case of flame propagation test, the closer the wire sample is to the vertical, the higher the flame retardancy is required. Therefore, it is difficult to satisfy the flame retardancy of the vertical flame retardancy required by the ISO standard in the wire sample having horizontal flame retardancy required by the JASO standard.

It is necessary to increase the content of the flame retardant added to the insulating composition in order to satisfy the high flame retardancy required by the ISO standard. In this case, it is difficult to avoid the deterioration of the mechanical properties and the cold resistance and the abrasion resistance may be lowered. Resistance to cold and abrasion are also more strict than those of JASO standards, so that it is extremely difficult to satisfy flame resistance, cold resistance and abrasion resistance according to ISO standards at the same time.

1 schematically shows a cross section of a halogen-free polypropylene insulated wire corresponding to T3 grade (125 DEG C) among ISO standards.

As shown in FIG. 1, the insulated wire may include a conductor 10 and an insulating layer 20 surrounding it. The ISO standard specifies the dimensions of the insulation layer 20 and the wire outer diameter in accordance with the cross-sectional area of the conductor 10.

The cross sectional area of the conductor 10 varies depending on the sectional area of the conductor 10, but the smaller the sectional area of the conductor 10 is, the harder it is to satisfy the wear resistance. On the other hand, , It is extremely difficult to simultaneously satisfy the physical properties required in the wires to which the conductors 10 of various cross-sectional areas are applied at the same time.

Accordingly, it is an object of the present invention to provide an insulating composition which is a non-halogenated polypropylene insulating composition for electric wires satisfying the T3 grade (125 DEG C) among the ISO standards and which satisfies the high flame retardancy required by the ISO standard and is inferior in cold resistance and abrasion resistance, An insulating composition which can be applied to various wires having various cross-sectional conductors is desperately required.

An object of the present invention is to provide an insulating composition satisfying the high flame resistance required by the ISO standard.

It is another object of the present invention to provide an insulating composition excellent in physical properties such as cold resistance and abrasion resistance which are in conflict with each other even though the flame retardancy is excellent.

Further, it is an object of the present invention to provide an insulating composition applicable to various electric wires to which conductors having various cross-sectional areas according to the ISO standard are applied.

In order to solve the above problems,

A conductor and an insulating layer surrounding the conductor, wherein the insulating composition comprises a polypropylene block copolymer, a polymerized thermoplastic polyolefin, and a grafted polypropylene homopolymer Based on 100 parts by weight of the base resin, the content of the polypropylene block copolymer is 20 to 60 parts by weight, the content of the polymerizable thermoplastic polyolefin is 30 to 70 parts by weight, Wherein the content of the maleic anhydride-grafted polypropylene homopolymer is 8 to 30 parts by weight.

Here, when the cross-sectional area of the conductor is 0.22 mm 2 or less, the content of the polypropylene block copolymer is 35 to 50 parts by weight, the content of the polymerizable thermoplastic polyolefin is 30 to 40 parts by weight based on 100 parts by weight of the base resin, Wherein the content of the maleic anhydride-grafted polypropylene homopolymer is 20 to 30 parts by weight, and when the cross-sectional area of the conductor is 0.35 to 0.75 mm 2, the amount of the polypropylene block copolymer , The content of the polymerizable thermoplastic polyolefin is 30 to 35 parts by weight, the content of the maleic anhydride-grafted polypropylene homopolymer is 8 to 13 parts by weight, the cross-sectional area of the conductor is 1.0 To 6.0 mm < 2 >, the content of the polypropylene block copolymer is within 20 30 parts by weight, the content of the polymerized thermoplastic polyolefin content of 60 to 70 parts by weight of the maleic anhydride grafted polypropylene homopolymer provides an insulating composition, characterized in that deny 8 to 13 wt.

When the cross-sectional area of the conductor is equal to or less than 0.75 mm 2, the content (A) of the polypropylene block copolymer is defined by the following formula (1) based on 100 parts by weight of the base resin, and the maleic anhydride- The content (B) of the propylene homopolymer is defined by the following formula (2)

[Equation 1]

A = [aln {cross-sectional area of conductor (mm 2) -0.2199} + 0.6029] * 100

In the above equation (1)

a is from 0.12 to 0.27.

&Quot; (2) "

B = [0.0347 * cross-sectional area of conductor (mm 2) + 0.6447-A / 100] * 100

(A) of the polypropylene block copolymer is defined by the following formula (3) based on 100 parts by weight of the base resin when the cross-sectional area of the conductor is 1.0 mm 2 or more, and the maleic anhydride grafted polypropylene alone And the content (B) of the polymer is defined by the following formula (4).

&Quot; (3) "

A = [-0.044 ln {cross-sectional area of conductor (mm 2)} + b] * 100

In Equation (3)

b is 0.27 to 0.3.

&Quot; (4) "

B = [- 0.052 ln {cross-sectional area of conductor (mm 2)} + 0.3831-A / 100] * 100

On the other hand, the polypropylene block copolymer has a melting point of 160 to 170 占 폚, a specific gravity of 0.900 to 0.920 and a load of 2.16 kg and a melt volume index (MFR) of 3 to 5 under a temperature condition of 190 占 폚. Lt; / RTI >

The polymerizable thermoplastic polyolefin has a melting point of 135 to 145 DEG C and a shore A hardness of 70 to 80,

And the additive includes 95 to 110 parts by weight of a metal hydroxide whose surface is modified to be hydrophobic based on 100 parts by weight of the base resin.

Wherein the metal hydroxide comprises a combination of aluminum hydroxide, magnesium hydroxide, or an alloy.

On the other hand, the additive provides an insulating composition, characterized in that it comprises a lubricant, an antioxidant, a processing aid, or a combination thereof.

Wherein the antioxidant comprises at least one antioxidant selected from the group consisting of a primary antioxidant, a secondary antioxidant, and an antioxidant.

And an insulation layer formed from the insulation composition according to any one of claims 1 to 3 to surround the conductor and the conductor.

The insulating composition according to the present invention possesses high flame retardancy required by the ISO standard, and exhibits excellent effects such as cold resistance and abrasion resistance which are in conflict with each other.

In addition, the insulating composition according to the present invention exhibits an excellent effect that can be applied to insulating layers of wires of various standards to which conductors having various cross-sectional areas are applied.

1 schematically shows a cross section of a halogen-free polypropylene insulated wire corresponding to T3 grade (125 DEG C) among ISO standards.

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 having excellent flame retardancy, particularly an insulating composition for an insulating layer of a halogen-free polypropylene non-crosslinked insulating wire corresponding to T3 grade (125 ° C) among ISO standards. Additives.

The base resin may include a polypropylene block copolymer, a polymerized thermoplastic polyolefin (rTPO), and a maleic anhydride grafted polypropylene homopolymer. Here, the polypropylene block copolymer as the base resin acts to improve wear resistance of the insulating layer formed from the insulating composition.

The polypropylene block copolymer includes a block copolymer of propylene and another? -Olefin such as ethylene, propene, butene, pentene, hexene, heptene or octene and has a melting point of 160 to 170 ° C., The melt volume index (MFR) under a load of 0.900 to 0.920, a load of 2.16 kg and a temperature condition of 230 ° C may be 3 to 5.

If the melting point of the polypropylene block copolymer is less than 160 캜, the heat resistance of the insulating layer formed from the insulating composition may be insufficient, so that it may be difficult to apply the insulating composition to the insulating layer of the T3 grade (125 캜) automobile electric wire. In addition, when the melt volume index (MFR) is less than 3, the molecular weight and crystallinity are excessive, and the extrudability of the insulating composition and the compatibility of the base resin and the additive, particularly the flame retardant described later, If it is more than 5, the mechanical strength, abrasion resistance, etc. of the insulating layer formed from the insulating composition may be deteriorated.

The content of the polypropylene block copolymer may be 20 to 60 parts by weight based on 100 parts by weight of the base resin. When the content of the polypropylene block copolymer is less than 20 parts by weight, the hardness of the insulating layer formed from the insulating composition is lowered and the abrasion resistance is lowered. When the content of the polypropylene block copolymer is more than 60 parts by weight, And the physical properties such as flexibility and cold resistance may be insufficient.

The polymerizable thermoplastic polyolefin (rTPO) as the base resin improves the flexibility and cold resistance of the insulating layer formed from the insulating composition and improves the compatibility of the base resin and the additive, particularly, the flame retardant described later, Propylene and has a melting point of 135 to 145 DEG C and a shore A hardness of 70 to 80. [

The content of the polymerizable thermoplastic polyolefin (rTPO) may be 30 to 70 parts by weight based on 100 parts by weight of the base resin. If the content of the polymerizable thermoplastic polyolefin (rTPO) is less than 30 parts by weight, the compatibility of the base resin with the additive, particularly the flame retardant described below may be lowered, and the elongation percentage of the insulating layer formed from the insulating composition may be greatly decreased, And cold resistance may be inadequate, while if it exceeds 70 parts by weight, the hardness of the insulating layer may be lowered and the abrasion resistance may be lowered.

The polypropylene homopolymer in which the maleic anhydride is grafted as the base resin further improves the abrasion resistance of the insulating layer formed from the insulating composition. The content of the maleic anhydride-grafted polypropylene homopolymer may be 8 to 30 parts by weight based on 100 parts by weight of the base resin.

When the content of the maleic anhydride-grafted polypropylene homopolymer is less than 8 parts by weight, the compatibility of the base resin with the additive, particularly the flame retardant described later, may be lowered and the abrasion resistance of the insulating layer may be lowered, If the amount is more than 30 parts by weight, the bonding force between the base resin and the additive, particularly a flame retardant described later, is excessive, and the elongation percentage of the insulating layer is lowered, so that flexibility and cold resistance may be insufficient.

As the cross-sectional area of the electric wire including the insulating layer formed from the insulating composition according to the present invention increases, the thickness of the insulating layer increases and wear resistance improves, but flexibility and cold resistance deteriorate. Therefore, The content of each of the resins included as the base resin in the insulating composition forming the insulating layer should be adjusted differently according to the conductor cross-sectional area.

For example, when the conductor cross-sectional area of the electric wire including the insulating layer formed from the insulating composition is less than 0.22 mm 2 on the basis of 100 parts by weight of the base resin, the content of the polypropylene block copolymer is 35 to 50 parts by weight , The content of the polymerizable thermoplastic polyolefin is 30 to 40 parts by weight, and the content of the maleic anhydride-grafted polypropylene homopolymer is 20 to 30 parts by weight.

When the cross-sectional area of the conductor is a fine line of 0.35 to 0.75 mm 2, the content of the polypropylene block copolymer is 55 to 60 parts by weight, the content of the polymerizable thermoplastic polyolefin is 30 to 35 parts by weight, the maleic anhydride is grafted The content of the polypropylene homopolymer may be 8 to 13 parts by weight.

In the case of a conductor having a cross-sectional area of 1.0 to 6.0 mm 2, the content of the polypropylene block copolymer is 20 to 30 parts by weight, the content of the polymerizable thermoplastic polyolefin is 60 to 70 parts by weight, the maleic anhydride is grafted The content of the polypropylene homopolymer may be 8 to 13 parts by weight.

(A) of the polypropylene block copolymer is defined by the following formula (1) based on 100 parts by weight of the base resin, and the content of the maleic anhydride The content (B) of the grafted polypropylene homopolymer can be defined by the following equation (2).

[Equation 1]

A = [aln {cross-sectional area of conductor (mm 2) -0.2199} + 0.6029] * 100

In the above equation (1)

a is from 0.12 to 0.27.

&Quot; (2) "

B = [0.0347 * cross-sectional area of conductor (mm 2) + 0.6447-A / 100] * 100

When the cross-sectional area of the conductor is a critical line of 1.0 mm 2 or more, the content (A) of the polypropylene block copolymer is defined by the following formula (3) based on 100 parts by weight of the base resin, and the maleic anhydride is grafted The content (B) of the polypropylene homopolymer can be defined by the following equation (4).

&Quot; (3) "

A = [-0.044 ln {cross-sectional area of conductor (mm 2)} + b] * 100

In Equation (3)

b is 0.27 to 0.3.

&Quot; (4) "

B = [- 0.052 ln {cross-sectional area of conductor (mm 2)} + 0.3831-A / 100] * 100

The insulating composition according to the present invention has a flame retardancy according to the ISO standard and a trade-off relationship between the above-mentioned base resin and the precisely controlled content when forming an insulation layer of wires of various specifications such as fine wire, fine wire, And exhibits excellent effects of simultaneously improving physical properties such as weather resistance and abrasion resistance.

The insulating composition according to the present invention may include a flame retardant as the additive, and the flame retardant may include a metal hydroxide such as aluminum hydroxide, magnesium hydroxide, and the like. When the surface of the metal hydroxide is modified to be hydrophobic, compatibility with the base resin is increased and the flame retardant is uniformly dispersed in the base resin Even when a relatively small amount of the flame retardant is added, flame retardancy can be realized.

The flame retardant may be included in an amount of 95 to 110 parts by weight based on 100 parts by weight of the base resin. If the content of the flame retardant is less than 95 parts by weight, the flame retardancy may be insufficient. If the content of the flame retardant exceeds 110 parts by weight, the extrudability of the insulating composition may be deteriorated and the surface characteristics of the insulating layer formed from the insulating composition may be deteriorated.

In addition, the insulating composition according to the present invention may further include a lubricant, an antioxidant, a processing aid, and the like as the additive. Here, the antioxidant may include a primary antioxidant such as a phenol-based or amine-based antioxidant, a secondary antioxidant such as a thio-based or phosphorus-based antioxidant, or a combination thereof.

[Example]

1. Manufacturing Example

Using a Pilot 3L kneader, insulating compositions were prepared at 190 ° C with the constituents and contents as shown in Tables 1 to 3 below, and a wire sample of each fine wire, fine wire, and fine wire was measured using a 45 mm extruder . The units of the constituent components shown in Tables 1 to 3 below are parts by weight.

Fine lines (0.22SQ) Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Resin 1 40 42 40 58 Resin 2 40 Resin 3 40 Resin 4 35 34 35 35 35 32 Resin 6 25 24 25 25 25 10 Flame Retardant 1 100 105 100 95 80 100 Antioxidant 1 2 2 2 2 2 2 Antioxidant 2 2 2 2 2 2 2 Antioxidant 3 One One One One One One Lubricant One One One One One One

Fine wire (0.35SQ) Example 3 Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Resin 1 58 60 25 65 58 Resin 4 32 30 65 10 30 32 Resin 5 60 Resin 6 10 10 10 25 10 Resin 7 10 Flame Retardant 1 100 105 100 95 105 100 Antioxidant 1 2 2 2 2 2 2 Antioxidant 2 2 2 2 2 2 2 Antioxidant 3 One One One One One One Lubricant One One One One One One

(1SQ) Example 5 Example 6 Comparative Example 9 Comparative Example 10 Comparative Example 11 Resin 1 25 27 58 25 25 Resin 4 65 64 32 65 65 Resin 6 10 9 10 10 10 Flame Retardant 1 100 100 130 100 Flame Retardant 2 105 Antioxidant 1 2 2 2 2 2 Antioxidant 2 2 2 2 2 2 Antioxidant 3 One One One One Lubricant One One One One One

Resin 1: Polypropylene block copolymer (Tm: 166 占 폚, specific gravity: 0.90, MFR (2.16 kg, 230 占 폚): 4.0)

- Resin 2: Polypropylene block copolymer (Tm: 165 캜, specific gravity: 0.91, MFR (2.16 kg, 230 캜): 10.0)

Resin 3: High density polyethylene (Tm: 130 占 폚, specific gravity: 0.93, MFR (2.16 kg, 230 占 폚): 0.7)

Resin 4: Polymerization type thermoplastic polyolefin (Tm: 141 占 폚, specific gravity: 0.87, MFR (2.16 kg, 230 占 폚): 0.6)

- Resin 5: Polymerization type thermoplastic polyolefin (Tm: 161 캜, specific gravity: 0.88, MFR (2.16 kg, 230 캜): 0.6)

Resin 6: Polypropylene grafted with maleic anhydride

- Resin 7: Ethylene vinyl acetate grafted with maleic anhydride

Flame Retardant 1: Magnesium hydroxide coated with vinyl silane

- Flame retardant 2: Magnesium hydroxide

- Antioxidant 1: Phenolic antioxidant (primary antioxidant)

- Antioxidant 2: Sulfur antioxidant (secondary antioxidant)

- Antioxidant 3: Phenolic antioxidant

- Lubricant: PE-based wax

2. Property evaluation

1) Evaluation of heat resistance

Heat resistance evaluation was carried out according to ISO 6722 standard. The heat resistance evaluation was divided into a short-term heat resistance test and a long-term heat resistance test. In the short-term heat resistance test, the wire samples of the examples and comparative examples were retained in a 150 ° C oven for 240 hours, , And the wire sample that has been evaluated by the winding test should pass the underwater voltage test at a voltage of 1 kV and pass the test. In the long-term heat resistance test, the wire samples of the examples and the comparative examples were allowed to stand for 3,000 hours in a 125 ° C oven, and then the wire was evaluated for cracks. The wire samples subjected to the wire evaluation were subjected to an underwater voltage test at a voltage of 1 kV It should be no pass.

2) Evaluation of oil resistance

The oil resistance evaluation was performed in accordance with the ISO 6722 standard. The oil resistance evaluation was divided into short-term oil and long-term oil resistance tests. The short-term oil resistance test was conducted in an oven at 125 ° C for 240 hours to sample the wire samples of the examples and comparative examples minus 10 seconds of oil specified in the specification. , And the cable sample subjected to the evaluation of the winding should be tested for underwater voltage with a voltage of 1 kV so that there is no abnormality. In the long-term oil-resistance test, the electric wire samples of Examples and Comparative Examples in which oil was immersed for 10 seconds in the standard oil for 10 seconds were retained in an oven at 125 캜 for 240 hours and then repeated four times. During the last stay, 280 hours were allowed to stay for a total of 1,000 hours There should be no cracks by proceeding with the winding evaluation, and the electric wire sample which has completed the evaluation of the winding should be tested for underwater withstand voltage under 1kV voltage.

3) Cold resistance evaluation

The cold resistance evaluation was carried out in accordance with the ISO 6722 standard. The cold resistance test was carried out in an oven at -40 DEG C for 4 hours, and then the wire sample was kept for 4 hours. Thereafter, the wire was evaluated for cracks and the wire sample subjected to the wire wrapping evaluation was subjected to an underwater voltage test at a voltage of 1 kV There should be no.

4) Abrasion resistance evaluation

Abrasion resistance evaluation was carried out according to ISO 6722 standard. The abrasion resistance test is divided into abrasion test in the sandpaper and abrasion test in the blade, and the load and the acceptance standard are different according to the conductor cross-sectional area.

5) Evaluation of flame retardancy

The flame retardancy evaluation was carried out in accordance with the ISO 6722 standard. A flame-retardant test was carried out in such a manner that a wire sample of the examples and comparative examples was installed at an angle of 45 ° with respect to the ground, and the burner was also installed at an angle of 45 ° with respect to the ground. If the cross - sectional area of the conductor is 2.5 mm2 or less, the application time of the flame is 15 seconds. If the conductor cross - sectional area is 2.5 mm2 or more, the application time of the flame is 30 seconds.

The evaluation results of the physical properties are shown in Tables 4 to 6 below.

Fine lines (0.22 SQ) spec. Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Heat resistance
long time Crack X Crack X Crack X Crack X Melt away Crack X Crack X short-term Crack X Crack X Crack X Crack X Melt away Crack X Crack X Oil resistance
long time Crack X Crack X Crack X Crack X Melt away Crack X Crack X short-term Crack X Crack X Crack X Crack X Melt away Crack X Crack X Cold resistance Crack X Crack X Crack X Crack X Crack O Crack X Crack X Abrasion resistance
Sandpaper 250mm 600 585 406 475 652 457 knife 150 times 191 178 113 152 238 116 Flammability 70 seconds 10 11 9 11 X 10

Fine (0.35 SQ) spec. Example 3 Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Heat resistance
long time Crack X Crack X Crack X Crack X Crack X Crack X Crack X short-term Crack X Crack X Crack X Crack X Crack X Crack X Crack X Oil resistance
long time Crack X Crack X Crack X Crack X Crack X Crack X Crack X short-term Crack X Crack X Crack X Crack X Crack X Crack X Crack X Cold resistance Crack X Crack X Crack X Crack X Crack O Crack O Crack X Abrasion resistance
Sandpaper 250mm 618 597 372 732 572 451 knife 150 times 246 218 109 262 169 112 Flammability 70 seconds 10 13 11 9 8 10

Tight line (1.0 SQ) spec. Example 5 Example 6 Comparative Example 9 Comparative Example 10 Comparative Example 11 Heat resistance
long time Crack X Crack X Crack X Crack X Crack X Crack O short-term Crack X Crack X Crack X Crack X Crack X Crack O Oil resistance
long time Crack X Crack X Crack X Crack X Crack X Crack X short-term Crack X Crack X Crack X Crack X Crack X Crack X Cold resistance Crack X Crack X Crack X Crack O Crack O Crack X Abrasion resistance
Sandpaper 400mm 1481 1522 1057 1277 1310 knife 400 times 1000 ↑ 1000 ↑ 1000 ↑ 672 1000 ↑ Flammability 70 seconds 10 11 9 6 9

As shown in Tables 4 to 6, the electric wire samples of Examples 1 to 6 including the insulating layer formed from the insulating composition according to the present invention were tested in accordance with the ISO standard for both conductors of fine lines, fine lines, Flame retardancy and excellent physical properties such as cold resistance, abrasion resistance, heat resistance and oil resistance which are in conflict with each other.

On the other hand, in the case of the ultra fine wire, the wire sample of Comparative Example 1 was attempted to improve the workability by using the resin having an excessively high melt volume index (MFR), but the abrasion resistance did not satisfy the specification. In the wire sample of Comparative Example 2, Although it was tried to lower the processing temperature, the heat and oil temperature conditions of the samples, which were not crosslinked type, were similar to the melting point of the resin, so that they were melted in the oven and cracks were observed in the cold resistance evaluation test. The sample was intended to improve the abrasion resistance and cold resistance by reducing the content of the flame retardant agent, but the flame retardancy was below the standard. In the wire sample of Comparative Example 4, the cost of the prescription was reduced by applying the prescription for the fine wire to the ultra fine wire, Was found to be below the specification.

In the case of the fine wire, the wire sample of Comparative Example 5 was applied to the fine wire, but the abrasion resistance evaluation result was below the specification. The wire sample of Comparative Example 6 increased the content of Resin 1 and Resin 6, And cracks were found as a result of the cold resistance evaluation. The wire sample of Comparative Example 7 was replaced with Resin 5 without applying Resin 1, and a resin having a low melt volume index (MFR) was applied to improve the abrasion resistance But the abrasion resistance was not improved, and the wire sample of Comparative Example 8 was replaced with Resin 7 without applying Resin 6, but the abrasion resistance did not satisfy the specification.

In the case of the intermediate wire, the wire sample of Comparative Example 9 was found to have excellent abrasion resistance, but a crack was found as a result of the cold resistance evaluation, and the evaluation item was not satisfied. In the wire sample of Comparative Example 10, the content of the flame retardant was increased. The evaluation result was below the standard, and the electric wire sample of Comparative Example 11 did not satisfy the criteria of heat resistance evaluation by applying only one antioxidant.

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 (10)

1. An insulating composition for an insulating layer of an electric wire comprising a conductor and an insulating layer surrounding the conductor,
Wherein the insulating composition comprises a base resin comprising a polypropylene block copolymer, a polymerized thermoplastic polyolefin and a maleic anhydride grafted polypropylene homopolymer and an additive,
Wherein the content of the polypropylene block copolymer is 20 to 60 parts by weight based on 100 parts by weight of the base resin, the content of the polymerizable thermoplastic polyolefin is 30 to 70 parts by weight, the maleic anhydride is grafted with polypropylene Wherein the content of the homopolymer is 8 to 30 parts by weight. The method according to claim 1,
The content of the polypropylene block copolymer is 35 to 50 parts by weight and the content of the polymerizable thermoplastic polyolefin is 30 to 40 parts by weight based on 100 parts by weight of the base resin when the sectional area of the conductor is 0.22 mm 2 or less, The content of the polypropylene homopolymer grafted with the acid anhydride is 20 to 30 parts by weight,
The content of the polypropylene block copolymer is 55 to 60 parts by weight and the content of the polymerizable thermoplastic polyolefin is 30 to 35 parts by weight based on 100 parts by weight of the base resin when the cross section of the conductor is 0.35 to 0.75 mm 2, The content of the maleic anhydride-grafted polypropylene homopolymer is 8 to 13 parts by weight,
The content of the polypropylene block copolymer is 20 to 30 parts by weight based on 100 parts by weight of the base resin, the content of the polymerizable thermoplastic polyolefin is 60 to 70 parts by weight, Wherein the content of the maleic anhydride-grafted polypropylene homopolymer is 8 to 13 parts by weight. 3. The method of claim 2,
(A) of the polypropylene block copolymer is defined by the following formula (1) based on 100 parts by weight of the base resin when the cross-sectional area of the conductor is equal to or smaller than 0.75 mm 2, and the maleic anhydride grafted polypropylene alone The content (B) of the polymer is defined by the following formula (2)
[Equation 1]
A = [aln {cross-sectional area of conductor (mm 2) -0.2199} + 0.6029] * 100
In the above equation (1)
a is from 0.12 to 0.27.
&Quot; (2) "
B = [0.0347 * cross-sectional area of conductor (mm 2) + 0.6447-A / 100] * 100
(A) of the polypropylene block copolymer is defined by the following formula (3) based on 100 parts by weight of the base resin when the cross-sectional area of the conductor is 1.0 mm 2 or more, and the maleic anhydride grafted polypropylene alone And the content (B) of the polymer is defined by the following formula (4).
&Quot; (3) "
A = [-0.044 ln {cross-sectional area of conductor (mm 2)} + b] * 100
In Equation (3)
b is 0.27 to 0.3.
&Quot; (4) "
B = [- 0.052 ln {cross-sectional area of conductor (mm 2)} + 0.3831-A / 100] * 100 4. The method according to any one of claims 1 to 3,
Wherein the polypropylene block copolymer has a melt volume index (MFR) of 3 to 5 under a load of 160 to 170 占 폚, a specific gravity of 0.900 to 0.920 and a load of 2.16 kg and a temperature of 230 占 폚. 4. The method according to any one of claims 1 to 3,
Wherein the polymerizable thermoplastic polyolefin has a melting point of 135 to 145 DEG C and a shore A hardness of 70 to 80. The thermoplastic polyolefin according to claim 1, 4. The method according to any one of claims 1 to 3,
Wherein the additive comprises 95 to 110 parts by weight of a metal hydroxide whose surface has been modified to be hydrophobic based on 100 parts by weight of the base resin. The method according to claim 6,
Wherein the metal hydroxide comprises aluminum hydroxide, magnesium hydroxide, or a combination thereof. 4. The method according to any one of claims 1 to 3,
Wherein the additive comprises a lubricant, an antioxidant, a processing aid, or a combination thereof. 9. The method of claim 8,
Wherein the antioxidant comprises at least one antioxidant selected from the group consisting of a primary antioxidant, a secondary antioxidant, and a antioxidant. A conductor comprising a conductor and an insulation layer surrounding the conductor and formed from the insulation composition of any one of claims 1 to 3.

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