KR102076454B1 - Insulating composition with high fire retardance - Google Patents

Abstract

The present invention relates to a high refractory insulating composition. Specifically, the present invention not only has a high refractory insulation property at a high temperature, but also causes excellent workability due to excellent flexibility, excellent deposition properties, and the like, and a simple manufacturing process and can reduce manufacturing cost, a high refractory insulation composition. It is about.

Description

Insulating composition with high fire retardance

The present invention relates to a high refractory insulating composition. Specifically, the present invention not only has a high refractory insulation property at a high temperature, but also causes excellent workability due to excellent flexibility, excellent deposition properties, and the like, and a simple manufacturing process and can reduce manufacturing cost, a high refractory insulation composition. It is about.

The cross-sectional structure of a typical high fireproof cable is as shown in Figures 1a and 1b. As shown in FIGS. 1A and 1B, the high fireproof cable may be made of a fire resistant tape 5, an insulating layer 2, an inclusion 3, a sheath layer 4, and the like around the conductor 1.

High-rise buildings or large factories can lead to massive casualties in the event of a fire, so various electrical facilities, such as electric doors, elevators, and lighting equipment, that are required for evacuation for a predetermined time that people in the building can evacuate. Power should be supplied to fire alarm, emergency light and alarm sensor. Accordingly, the high fireproof cable is required to have a fire resistance capable of supplying power by maintaining insulation performance for a predetermined time at a high temperature of 750 ° C. or higher, preferably about 950 ° C.

Mica tape is used as the fire resistant tape 5. That is, it is used by winding the mica tape on the conductor 1 in a spiral manner and then extruding the insulator thereon. The mica tape is a product made by using a reinforcing material such as a glass tape or a polyester film after impregnating an epoxy resin in a wire hard or soft mica. The mica tape has been widely commercialized as a fireproof cable material due to its excellent heat resistance, fire resistance, electrical insulation, etc. in a flame at 800 to 900 ° C.

However, since the mica tape is a material in which mica powder is thinly spread on a glass tape or a polyester film and is easily broken and cracked by an external force, the mica tape may be separated according to the difference in manufacturing process capability or the manufacturing environment conditions. There is a problem that the performance as a refractory material can easily be changed.

In addition, the mica tape is spirally wound on the conductor 1, thereby reducing the flexibility of the cable, the installation properties and workability thereof, and the mica tape, which is the main raw material of the mica tape, is pulverized in the process of peeling the cable. There is a problem of flying around.

Because of the drawbacks of the mica tape, silicon is also used as a fireproof insulating material in accordance with some specific specifications. Silicon is also a material that can maintain electrical insulation to enable electricity in the flame of 800 ~ 900 ℃. In addition, as the silicon component decomposes at a high temperature, an oxide ash is generated, which is hardened by being adsorbed to the conductor, thereby protecting the conductor.

In addition, silicon insulating material has the advantages of excellent processability and flexibility compared to mica tape, but it is decisively expensive, and thus the workability at the time of installation is increased due to the rapid increase in material cost as the cross-sectional area of the cable increases and the close contact of the silicon insulating material to the conductor. There is a problem that it is somewhat degraded.

Therefore, the problem of the conventional high refractory material, that is, the difference in the refractory insulation performance of the high refractory material according to the difference in manufacturing process capability or the manufacturing environment conditions, the flexibility of the cable, the installation properties and the resulting workability is lowered EC 60331-1, IEC 60331-2, BS 6387, BS, which are further strengthened international fire test standards without causing problems such as dust blowing of high refractory materials during installation and expensive There is a need for a high fire resistant power cable having a new insulation material and an insulation layer made therefrom which exhibits fire resistant insulation at high temperatures in accordance with EN 50200, BS 8491 and is capable of maintaining insulation even in the more severe conditions of 1000 ° C and above. There is a situation.

It is an object of the present invention to provide a high refractory insulating composition having fireproof insulation performance at high temperatures in accordance with the international fire retardant test standards EC 60331-1, IEC 60331-2, BS 6387, BS EN 50200, BS 8491, which are further strengthened. It is done.

In addition, the present invention has a high refractory insulation, which has a fireproof insulation performance at the high temperature, and also has an excellent flexibility of the insulating layer to be produced, leading to excellent workability due to excellent laying properties of the cable including the insulating layer, and the like. It is an object to provide a composition.

Furthermore, it is an object of the present invention to provide a high refractory insulating composition which can simplify the manufacturing process of the insulating layer to be manufactured and the cable including the same and reduce the manufacturing cost.

In order to solve the above problems, the present invention,

A high refractory insulating composition comprising a base resin comprising a polyolefin resin, 120 to 160 parts by weight of one or more metal oxides, and 40 to 60 parts by weight of a flame retardant containing one or more metal hydroxides, based on 100 parts by weight of the base resin. Wherein the at least one metal hydroxide comprises at least one member selected from the group consisting of aluminum hydroxide, magnesium hydroxide, calcium hydroxide, magnesite hydroxide, basic magnesium carbonate, hydrotalcite and horn titer. It provides an insulation composition.

Here, the metal oxide is magnesium oxide, calcium oxide, potassium oxide, scandinium oxide, sodium oxide, boron oxide, barium oxide, silicon dioxide, titanium dioxide, zirconium dioxide, or a combination thereof, high refractory insulation To provide a composition.

In addition, the metal oxide provides a highly refractory insulating composition, characterized in that the metal oxide surface-modified by vinylsilane, stearic acid, oleic acid, aminopolysiloxane, or a combination thereof.

On the other hand, the metal hydroxide is a vinyl hydroxide, stearic acid, oleic acid, amino polysiloxane, it provides a high refractory insulating composition, characterized in that the metal hydroxide surface-modified by a combination thereof.

In addition, an inorganic flame retardant selected from the group consisting of red phosphorus, silicon-based compounds, boron compounds, and carbon powders based on 100 parts by weight of the base resin; Organic flame retardants selected from the group consisting of bromine flame retardants, chlorine flame retardants and fluorine flame retardants; Or 0.3 to 20 parts by weight of an auxiliary flame retardant including a combination thereof.

In addition, the polyolefin resin is a polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene copolymer or a combination thereof, provides a high refractory insulation composition.

Furthermore, based on 100 parts by weight of the base resin, it provides a high refractory insulating composition, characterized in that it further comprises 1 to 10 parts by weight of a crosslinking agent comprising a silane, an organic peroxide, ethylene butene copolymer, or a combination thereof. .

On the other hand, based on 100 parts by weight of the base resin, 0.1 to 5 parts by weight of a hindered phenol-based, phosphorus-based, imidazole-based, sulfur-based antioxidant, or a combination thereof; High molecular weight waxes, low molecular weight waxes, polyolefin waxes, paraffin waxes, paraffin oils, potassium stearate, barium stearate, lead stearate, metal soaps, organic silicones, fatty acid esters, fatty acid amides, fatty alcohols, fatty acids, or combinations thereof 0.5 to 8 parts by weight of lubricant; And 0.5 to 6 parts by weight of a processing aid comprising stearic acid, paraffin wax, crystalline wax, low molecular weight polyethylene wax, or a combination thereof.

The insulating layer of the high refractory insulating composition according to the present invention contains a specific metal oxide and a flame retardant in a specific base resin at a specific compounding ratio, thereby exhibiting excellent effects of exhibiting fire resistant insulating performance even at a high temperature of 950 ° C or higher.

In addition, the insulating layer of the high refractory insulating composition according to the present invention exhibits excellent fire resistant insulating performance at a high temperature even without using a fire resistant tape such as a mica tape, which has been used to impart flame retardancy, fire resistant insulation, etc. to a conventional cable. The problem of the fireproof tape, that is, spirally wound around the conductor of the cable reduces the flexibility of the cable, the fire resistance performance is different depending on the process capacity and manufacturing environment of the person who manufactures the fireproof tape, stripping mica for cable laying Problems such as dust blowing around can be avoided, and furthermore, the flexibility of the manufactured cable, the excellent laying property of the cable, workability and the like can be achieved.

Furthermore, the insulating layer of the high refractory insulating composition according to the present invention has excellent fire resistance insulation performance at a high temperature even without using expensive materials such as silicon insulating material which is superior in processability and flexibility compared to the conventional mica tape, and flexibility of the manufactured cable. As a result, excellent cable laying property and workability of the cable can be achieved, thereby simplifying the cable manufacturing process and reducing the manufacturing cost.

1 is a longitudinal cross-sectional view and a cross-sectional view schematically showing the cross-sectional structure of a conventional high refractory cable.
Figure 2 shows a longitudinal cross-sectional view and a cross-sectional view schematically showing the cross-sectional structure of a high fire resistant cable according to the present invention.

2 illustrates an embodiment of a high fire resistant power cable.

As shown in FIG. 2, the high refractory power cable may be disposed such that each sub core having the insulating layer 2 coated on the conductor 1 made of a conductive material such as copper or aluminum has three cores in a triangular shape. To fill an empty space excluding the space occupied by the sub-core in the sheath layer 4 to have a circular shape as a whole, it is made of an inclusion 3 made of a material such as synthetic resin, a sheath layer 4 for cable protection, and the like. Can be.

The size of the conductor, insulation layer, inclusions, sheath layer, etc. may vary depending on the use of the cable, transmission voltage, and the like, and the materials constituting the inclusion and sheath layer may be the same as or different from the materials constituting the insulation layer. have.

The high refractory insulation composition which concerns on this invention which comprises the insulating layer 2 of a high refractory power cable contains a base resin.

Since the polymer constituting the base resin is mostly an electrically insulating material, there is no particular limitation. In order for electricity to flow, there must be positive charges or free electrons such as ions or metals that can move electrons, because the polymer is a material composed of covalent bonds between carbons, so there is almost no such ability.

In general, polyolefins, preferably polyethylene, polypropylene, ethylene / propylene copolymers, ethylene / butene copolymers, and the like may be used as the base resin constituting the insulation composition for a high refractory cable.

The polyethylene may comprise ethylene homopolymers and / or copolymers of ethylene with α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene. In addition, the polyethylene may include ultra low density polyethylene, low density polyethylene, linear low density polyethylene, high density polyethylene, or a mixture thereof, for example, a density of 0.86 to 0.98 g / cm 3 (measured by ASTM D-792). ), The melt index may be from 0.01 to 100 dg / min (measured by ASTM D-1238), the weight average molecular weight (Mw) is 40,000 to 200,000, the molecular weight distribution (Mw / Mn) is 1.5 to 8.

Meanwhile, the polypropylene includes a propylene homopolymer and / or a copolymer of propylene and ethylene or an α-olefin having 4 to 8 carbon atoms, for example, 1-butene, 1-pentene, 1-hexene, 1-octene, and the like. can do. In particular, the propylene copolymer may be a random copolymer or block copolymer in which propylene and ethylene and / or α-olefins are polymerized without regularity, wherein the comonomer content is from about 0.5 to 20 based on the total weight of the polymer Weight percent.

The polypropylene can also be used in the presence of a Ziegler-Natta catalyst having low stereospecificity, representatively of a complex salt consisting of titanium trichloride and aluminum diethylaluminum, and at about 70 ° C. and 5 atm. It can be easily prepared by polymerization of propylene. For details on the method for producing the polypropylene, for example, Albizzati et al. in "Polypropylene Handbook", Chapter 2, page 11 on wards (Hanser Publisher, 1996).

Furthermore, the polypropylene has, for example, a melt index of 0.01 to 1000 dg / min (measured by ASTM D-1238), a melting point (Tm) of 110 to 175 ° C (measured by DSC), a maximum The crystallization temperature may be 110 to 125 ° C. (as measured by DSC). Here, if the maximum crystallization temperature is less than 110 ℃ may be insufficient heat resistance of the insulating layer, if it is more than 125 ℃ may cause a problem that the tensile elongation at room temperature is lowered.

In addition, the polypropylene may have, for example, a weight average molecular weight (Mw) of 200,000 to 450,000. When the weight average molecular weight (Mw) is less than 200,000, mechanical properties of the insulating layer may be lowered, and when the weight average molecular weight is more than 450,000, there may be a problem in that workability is decreased due to high viscosity. In addition, the polypropylene may have, for example, a molecular weight distribution (Mw / Mn) of 2 to 8. If the molecular weight distribution (Mw / Mn) is less than 2, there may be a problem that the workability is lowered to a high viscosity, and if it is more than 8, mechanical properties are lowered.

The polypropylene has an electrical property comparable to that of polyethylene, and in particular, has excellent heat resistance compared to polyethylene.

On the other hand, the polyethylene and polypropylene may be a non-crosslinked or crosslinked resin. Here, the crosslinked polyethylene and the crosslinked polypropylene may be prepared by silane, organic peroxides such as dicumyl peroxide (DCP), ethylene butene copolymer, or the like as a crosslinking agent. However, crosslinked polyethylene and crosslinked polypropylene have disadvantages that are difficult to recycle, and if crosslinking or scorch occurs early in the production of the insulating layer, it may cause long-term extrudability such as inability to exhibit uniform production capacity. . The crosslinking agent may be added in an amount of 1 to 10 parts by weight based on 100 parts by weight of the base resin.

The insulation composition constituting the insulation layer 2 of the high refractory power cable according to the invention is characterized in that it further comprises a metal oxide. The metal oxide may be magnesium oxide, calcium oxide, potassium oxide, scandium oxide, sodium oxide, boron oxide, barium oxide, silicon dioxide, titanium dioxide, zirconium dioxide, or a combination thereof. Such metal oxides lose their flexibility and harden at a high temperature of about 500 ° C. or more, thereby protecting the conductor and enabling energization.

The metal oxide may be surface modified by vinylsilane, stearic acid, oleic acid, aminopolysiloxane, or the like. Since the metal oxide is hydrophilic with high surface energy, while the base resin is hydrophobic with low surface energy, it is preferable to use a surface-modified metal oxide for uniform dispersion of the metal oxide in the base resin. desirable.

The metal oxide may be included in an amount of 120 to 160 parts by weight based on 100 parts by weight of the base resin. When the content of the metal oxide is less than 120 parts by weight, the breakdown voltage characteristic may be lowered, which may cause ignition easily at low voltage, whereas when the content of the metal oxide is greater than 160 parts by weight, the elongation rate, flexibility, and the like of the insulating layer may be reduced.

The insulating composition constituting the insulating layer 2 of the high refractory power cable according to the present invention may further comprise a flame retardant. The flame retardant may be a metal hydroxide such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide, magnesium hydroxide, basic magnesium carbonate, hydrotalcite, honite, or a combination thereof, preferably magnesium hydroxide. In addition, the metal hydroxide may be a metal hydroxide surface-treated with vinylsilane, stearic acid, oleic acid, amino polysiloxane, or a combination thereof.

The flame retardant may be included from 40 to 60 parts by weight based on 100 parts by weight of the base resin. If the content of the flame retardant is less than 40 parts by weight can not exhibit the desired flame retardant properties, if the content of more than 60 parts by weight may reduce the tensile strength, elongation rate, compression workability, etc. of the insulating layer prepared from the insulating composition.

In the highly refractory insulating composition according to the present invention, an auxiliary flame retardant may be used together with the flame retardant. The secondary flame retardant may reduce the content of the flame retardant and may increase the flame retardant effect. The auxiliary flame retardant may be a red phosphorus, a silicon compound, a boron compound, a carbon powder, or a combination thereof, and a bromine, chlorine or fluorine-based organic flame retardant may be used. The auxiliary flame retardant may be 0.3 to 20 parts by weight based on 100 parts by weight of the base resin.

The high refractory insulating composition according to the present invention is added with an antioxidant, a lubricant, a processing aid, and other additives, in addition to the base resin, metal oxide, flame retardant, and auxiliary flame retardant, in order to satisfy the electrical and mechanical properties required for the cable according to the use. Can be.

As the antioxidant, hindered phenol-based, phosphorus-based, imidazole-based, and sulfur-based antioxidants are generally used. Preferably, hindered phenol-based and sulfur-based antioxidants may be blended or imidazole-based antioxidants may be used. . The content of the antioxidant may be 0.1 to 5 parts by weight based on 100 parts by weight of the base resin. When the content of the antioxidant is less than 0.1 parts by weight can not be expected to prevent the antioxidant effect on the heat resistance improvement, when the content of more than 5 parts by weight may cause a decrease in flame retardancy, mechanical properties.

The lubricant may include high molecular weight wax, low molecular weight wax, polyolefin wax, paraffin wax, paraffin oil, potassium stearate, barium stearate, lead stearate, metal soap, organic silicone, fatty acid ester, fatty acid amide, fatty alcohol, fatty acid, and the like. Can be used, the amount of the lubricant may be 0.5 to 8 parts by weight based on 100 parts by weight of the base resin. If the amount of the lubricant is less than 0.5 parts by weight may cause a decrease in viscosity and uneven mixing of the compounding agent during the compounding process, if more than 8 parts by weight, the viscosity of the composition is sharply lowered, the kneading becomes uneven and the oxygen index Can be degraded.

As the processing aid, stearic acid, paraffin wax, crystalline wax, low molecular weight polyethylene wax, or a combination thereof may be used, and the content of the processing aid may be 0.5 to 6 parts by weight based on 100 parts by weight of the base resin. When the content of the processing aid is less than 0.5 parts by weight of the compound flow during the extrusion may not be smooth, when the content of more than 6 parts by weight when the extrusion process, the viscosity of the composition decreases rather than smooth extrusion and the oxygen index is lowered Problems may arise. Clay, talc, calcium carbonate, combinations thereof may be used as the other additives.

EXAMPLE

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

1. Preparation of Examples

The insulating compositions of Examples 1 to 3 were prepared with the ingredients shown in Table 1 and their contents, and each specimen was prepared with a 4 mm dumbbell in accordance with IEC 60811-1-1. Here, the unit representing the content of the component is parts by weight.

division Example 1 Example 2 Example 3 Base material resin 100 100 100 Metal oxide 120 135 160 Flame retardant 55 55 55 Crosslinking agent 3 3 3 Antioxidant One One One Processing aid One One One

-Base resin: Polypropylene (manufacturer: LG Chem; product name: SP 312)-metal oxide: magnesium oxide (manufacturer: Postec; product name: PRMAG 40)

-Flame Retardant: Magnesium Hydroxide (Manufacturer: Albermarle; Product Name: magniffin H5)

-Crosslinking agent: Dicumyl peroxide (manufacturer: LG Chemical)

-Antioxidant: Irganox 1010 (Manufacturer: Ciba)

-Processing aid: PE WAX (Manufacturer: Southeast Petrochemical)

2. Mechanical property evaluation

Mechanical property evaluation test of the specimen prepared according to Examples 1 to 3 was performed at a tensile speed of 250mm / min in accordance with BS IEC 60811-1, tensile strength should be 0.51 kgf / mm2 or more, elongation is 150% or more.

As a result of the test, the tensile strengths of the specimens according to Examples 1 to 3 were all above 0.51 kgf / mm 2, which is the reference value, but it was confirmed that the elongation was lowered as the content of the metal oxide increased. Specifically, in Example 3, the metal oxide content of 160 parts by weight, it was confirmed that the elongation rate slightly exceeds 150%, the lowest reference value. Therefore, when the content of the metal oxide in the insulating composition exceeds 160 parts by weight, it is expected that the elongation will not reach the standard value, thereby reducing the flexibility and the installation properties of the insulating layer and the cable including the same prepared from the insulating composition It is judged that it is not suitable due to insufficient workability.

3. Withstand voltage characteristics

The withstand voltage test to confirm the fire resistance performance of the specimens prepared according to Examples 1 to 3 was performed according to KS C IEC 60243-1: 2002.

Specifically, to evaluate the applicability to 1 kV fireproof cable, two electrodes were installed in an electric furnace at 830 ° C, each specimen was cut to a size of 4 × 4 cm, placed between the two electrodes, and then 1 kV voltage. An insulation breakdown test was conducted to apply a. When the temperature in the furnace reached 830 ° C, the voltage was increased at 0.1 kV / 30 sec intervals after 30 minutes of maintenance, and the applied voltage at the time of dielectric breakdown was recorded. The breakdown voltage is the average of five measurements taken for each specimen.

This is a test to determine how much withstand voltage characteristics are generated when an abnormal voltage is generated by heat generated from the outside when a topic actually occurs.

As a result, the specimen according to Example 1 having a metal oxide content of 120 parts by weight was measured to have an insulation breakdown voltage of about 1.1 kV. Therefore, when the metal oxide content is less than 120 parts by weight, it is expected to have an insulation breakdown voltage of less than 1 kV, that is, withstand voltage characteristics, it was determined that it is not suitable for application to 1 kV class fireproof cable. On the other hand, the specimen according to Example 3 having a metal oxide content of 160 parts by weight exhibited an insulation breakdown voltage of about 2 kV, that is, it was confirmed that the metal oxide improves the fire resistance performance of the insulation composition.

4. Flame retardancy evaluation

Insulation composition according to the present invention to evaluate the flame retardancy according to the content of the flame retardant in the insulating composition constituting the insulating layer (2) of the high fire resistance power cable according to the present invention, the insulating composition according to Comparative Examples 1 and 2 shown in Table 2 below And specimens prepared therefrom. Here, the unit representing the content of the component is parts by weight.

division Comparative Example 1 Comparative Example 2 Base material resin 100 100 Metal oxide 155 140 Flame retardant 35 70 Crosslinking agent 3 3 Antioxidant One One Processing aid One One

-Base resin: Polypropylene (manufacturer: LG Chem; product name: SP 312)-metal oxide: magnesium oxide (manufacturer: Postec; product name: PRMAG 40)

-Flame Retardant: Magnesium Hydroxide (Manufacturer: Albermarle; Product Name: magniffin H5)

-Crosslinking agent: Dicumyl peroxide (manufacturer: LG Chemical)

-Antioxidant: Irganox 1010 (Manufacturer: Ciba)

-Processing aid: PE WAX (Manufacturer: Southeast Petrochemical)

This flame retardant test was performed in accordance with IEC 60332-1. Specifically, each specimen according to Example 3 and Comparative Examples 1 and 2 having a length of 600 ± 25 mm was vertically fixed and 180 mm of flame was applied to each specimen by a burner inclined at 45 ° with respect to the specimen. The combustion length should be less than 540 mm from the upper end of the specimen.

As a result of the test, another specimen of Example 3 containing 55 parts by weight of the flame retardant passed the flame retardant test, but the specimen of Comparative Example 1 containing 35 parts by weight of less than 40 parts by weight of the flame retardant was found to have a combustion length of 580 mm or more. The insulating composition of Comparative Example 2 containing 70 parts by weight of more than 60 parts by weight of a flame retardant was judged to be a composition that is not suitable for cables because of poor extrudability.

5. Severe Fire Test

Performance standards for cables required to maintain circuit integrity under British Standard BS 6387: 1994 to demonstrate that the insulating composition constituting the insulating layer 2 of the high fire resistance power cable according to the present invention has fire resistance even in harsher conditions. Fire tests according to Cat.C) of fire conditions were performed. Category C of BS 6387 is one of the harsh fire tests in which cables are flamed for 180 minutes at 950 ± 40 ° C.

Cable samples of Examples 1 and 3 and Comparative Examples 3 and 4 were prepared for performance comparison of the insulating composition constituting the insulating layer 2 of the high refractory power cable according to the present invention and the prior art. Samples of the cables of Examples 1 and 3 and Comparative Examples 3 and 4 respectively include the structure of a 0.6 / 1 kV power cable, a conductor of tin-plated copper, a size of 1.5SQ, an insulation layer 0.7 mm thick, according to IEC 60502. LSZH (Low Smoke Zero Halogen) and each made to have a 1 mm thick sheath layer.

However, the cable samples of Examples 1 and 3 have an insulation layer made from the respective insulation compositions of Examples 1 and 3, while the cable samples of Comparative Example 3 have an insulation layer made from crosslinked polyethylene (XLPE) and the conductors And a mica tape between and the insulation layer, wherein the cable sample of Comparative Example 4 comprises a silicon insulation layer.

As a result of the severe fire resistance test, as shown in Table 3 below, the cable sample of Comparative Example 3 further including a mica tape as a fire resistant tape was shorted at 128 minutes, and the cable of Comparative Example 4 including a silicon insulating layer. The sample was shorted in about 90 minutes by continually cracking and cracking the silicon at a high temperature of 950 ° C. over time. On the other hand, the cable samples of Examples 1 and 3 according to the present invention exhibited excellent fire resistance performance which lasted 180 minutes at 950 ± 40 ° C. and the appearance was also preserved undamaged at high temperatures.

division Test result Example 1 Pass Example 3 Pass Comparative Example 3 Fail, 128 minutes Comparative Example 4 Fail, 90 minutes

As described above, the insulating composition constituting the insulating layer 2 of the high refractory power cable according to the present invention includes 120 to 160 parts by weight of a metal oxide and 40 to 60 parts by weight of a flame retardant based on 100 parts by weight of the base resin. It has been confirmed that the mechanical properties such as flexibility, flexibility, and the like are excellent in fire resistance, flame retardancy, and workability. The present specification has been described with reference to a preferred embodiment of the present invention, but those skilled in the art have the following claims. Various modifications and changes of the present invention will be possible without departing from the spirit and scope of the invention as set forth herein. Therefore, it should be seen that all modifications included in the technical scope of the present invention are basically included in the scope of the claims of the present invention.

1: conductor 2: insulation layer
3: inclusions 4: sheath layer
5: fireproof tape

Claims (8)

As a high refractory insulating composition,
A base resin comprising a polyolefin resin, 120 to 160 parts by weight of one or more metal oxides, and 40 to 60 parts by weight of a flame retardant including one or more metal hydroxides, based on 100 parts by weight of the base resin,
The at least one metal hydroxide comprises at least one member selected from the group consisting of aluminum hydroxide, magnesium hydroxide, calcium hydroxide, magnesium hydroxide, basic magnesium carbonate, hydrotalcite and horn titer. The method of claim 1,
The metal oxide is magnesium oxide, calcium oxide, potassium oxide, scandinium oxide, sodium oxide, boron oxide, barium oxide, silicon dioxide, titanium dioxide, zirconium dioxide, or a combination thereof, high refractory insulation composition. The method of claim 2,
The metal oxide is a high refractory insulation composition, characterized in that the metal oxide surface-modified by vinylsilane, stearic acid, oleic acid, aminopolysiloxane, or a combination thereof. The method according to any one of claims 1 to 3,
The metal hydroxide is a vinyl hydroxide, stearic acid, oleic acid, amino polysiloxane, or a metal hydroxide surface-modified by a combination thereof, high refractory insulation composition. The method according to any one of claims 1 to 3,
An inorganic flame retardant selected from the group consisting of red phosphorus, silicon-based compounds, boron compounds, and carbon powders based on 100 parts by weight of the base resin; Organic flame retardants selected from the group consisting of bromine flame retardants, chlorine flame retardants and fluorine flame retardants; Or 0.3 to 20 parts by weight of an auxiliary flame retardant including a combination thereof. The method according to any one of claims 1 to 3,
The polyolefin resin is a polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene copolymer or a combination thereof, high refractory insulation composition. The method according to any one of claims 1 to 3,
On the basis of 100 parts by weight of the base resin, characterized in that it further comprises 1 to 10 parts by weight of a crosslinking agent comprising a silane, an organic peroxide, an ethylene butene copolymer, or a combination thereof. The method according to any one of claims 1 to 3,
0.1 to 5 parts by weight of a hindered phenol-based, phosphorus-based, imidazole-based, sulfur-based antioxidant, or a combination thereof based on 100 parts by weight of the base resin; High molecular weight waxes, low molecular weight waxes, polyolefin waxes, paraffin waxes, paraffin oils, potassium stearate, barium stearate, lead stearate, metal soaps, organic silicones, fatty acid esters, fatty acid amides, fatty alcohols, fatty acids, or combinations thereof 0.5 to 8 parts by weight of lubricant; And 0.5 to 6 parts by weight of a processing aid comprising stearic acid, paraffin wax, crystalline wax, low molecular weight polyethylene wax, or combinations thereof.

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