KR20200089961A - Silicone rubber composition having the high tensile strength and high tear strength, and high voltage silicone cable using the same - Google Patents

Abstract

The present invention relates to a silicone rubber composition having high tensile strength and high tear strength properties, and a high voltage cable using the same. More particularly, the present invention includes 71.50 to 96.00 wt% of silicone rubber, 0.99 to 7.20 wt% of a crosslinking agent, 0.10 to 3.50 wt% of a lubricant, 1.92 to 3.50 wt% of a heat resistance improver, and 0.99 to 14.30 wt% of a filler.

Description

Silicone rubber composition having high tensile strength and high tear strength characteristics and high voltage silicone cable using the same{SILICONE RUBBER COMPOSITION HAVING THE HIGH TENSILE STRENGTH AND HIGH TEAR STRENGTH, AND HIGH VOLTAGE SILICONE CABLE USING THE SAME}

The present invention relates to a high voltage silicone cable, and more particularly, to a high voltage silicone cable made of a silicone rubber composition having high tensile strength and high tear strength characteristics.

In general, the development and dissemination of electric vehicles, eco-friendly vehicles, are gradually spreading around the world in accordance with the strengthening of global environmental regulations and energy saving trends, and the demand for high-voltage cables to improve the performance of electric vehicles is increasing.

High-voltage cables used in electric vehicles need to secure flexibility in limited spaces in vehicles due to the large-capacity battery as well as withstand voltage and insulation resistance characteristics that can withstand high voltages. In addition to the withstand voltage and insulation resistance characteristics and flexibility, properties such as heat resistance, flame retardancy, low temperature flexibility, oil resistance and chemical resistance must be satisfied. In addition, not only the required physical properties, but also the dimensional stability and the smooth surface without protrusions for hunting of the exterior during wire extrusion molding should be simultaneously provided.

In addition, the exclusion of environmentally harmful substances such as halogens and heavy metals is a global trend, and DBDPO (decabromodiphenyl oxide) used as a specific bromine-based flame retardant that exhibits relatively good flame retardancy in polymers used for cables is suspected to be a dioxin generating material. Since it is banned in some European countries, it is necessary to use material properties with an eco-friendly flame retardant system.

In the case of an XLPE cable that is used as a high voltage cable, the outer diameter of the product is increased compared to a silicone rubber cable because the conductor cross-sectional area must be increased to increase the current capacity due to the lower heat resistance than silicon insulators. Due to the increased weight of the cable due to the increase in outer diameter and the low flexibility due to the high hardness, it has many constraints when designing automotive wiring.

However, silicone rubber cables have poor tensile and tear strength characteristics compared to XLPE cables, so there is a high possibility of problems such as tearing of insulators during the cable wiring harness process, so thick insulation compared to XLPE cables for quality control of automobile parts A thick silicone rubber cable should be applied to the vehicle.

In order to reduce fuel efficiency and increase the capacity of eco-friendly electric vehicles, there is an increasing demand for silicone rubber cables to which silicone rubber compositions having tensile strength and tear strength, which are the disadvantages of conventional silicone rubber, are equivalent or higher than XLPE cables. .

Korean Registered Patent No. 10-0508107

In view of the above, the technical problem to be achieved in the present invention is to use a low-hardness silicone rubber as a base resin to increase the mounting characteristics in an eco-friendly vehicle with a small space due to the installation of a large-capacity battery. Shore hardness A (Shore Hardness, shore A) is to provide a silicone rubber composition having a high flexibility at a level of 60 or less.

In addition, by using a silicone rubber composition having high tensile strength and high tear strength characteristics, a silicone rubber composition having high tensile strength and high tear strength characteristics capable of thinning an insulator in a high voltage cable at the level of an existing XLPE cable and a method for manufacturing the same It aims to provide.

In order to achieve the above object, the silicone rubber composition having high tensile strength and high tear strength characteristics of the present invention is silicone rubber (Silicone Rubber) 71.50 to 96.00% by weight, crosslinking agent 0.99 to 7.20% by weight, lubricant 0.10 to 3.50% by weight , Heat-resistant improver 1.92 to 3.50% by weight and filler 0.99 to 14.30% by weight; characterized in that it comprises a.

The silicone rubber, Shore Hardness A (Shore Hardness, shore A) may be used a silicone rubber of 60 or less, more preferably tensile strength is 1.08 kgf / mm ² or more, Shore Hardness A (Shore Hardness, shore A) is A mixture of any one or two selected from a first silicone rubber of 57 or less, and a second silicone rubber having a tensile strength of 1.22 kgf/mm ² or more and a Shore Hardness (Shore A) of 53 or less, may be used.

The crosslinking agent is used to improve the crosslinking properties by decomposing at high temperature to generate active radicals, 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, which are peroxide crosslinking agents, 2,5-dimethyl-2,5-bis-(tert-butylperoxy)-hexane (2,5-dimethyl-2,5-bis-(tert-butylperoxy)-hexane), bis(4-methylbenzoyl) Any one or more selected from peroxide (bis(4-methylbenzoyl)peroxide) may be used, and among them, it is preferable to use 2,4-dichlorobenzoyl peroxide, but is not limited thereto. No, and any crosslinking agent commonly used for silicone rubber can be used.

In the silicone rubber composition, the crosslinking agent is preferably included in an amount of 0.99 to 7.20% by weight, and if the content of the crosslinking agent is less than the above range, the thermal and mechanical properties of the silicone rubber deteriorate as the trace amount is added, and conversely, the above-mentioned range In more cases, the quality decrease occurs due to the residual of the unreacted crosslinking agent, so it is preferable that the content range of the crosslinking agent satisfies the above-mentioned range.

The lubricant is an additive that helps the dispersion of various additives contained in the silicone rubber composition, and then smooths the appearance during extrusion molding of the silicone rubber composition prepared with a high voltage silicone cable, wherein the lubricant is based on 100% by weight of the total lubricant. It is possible to use a polydimethylsiloxane-based silicone rubber containing 10 to 20% by weight of stearic acid.

If the content of the lubricant in the silicone rubber composition is less than 0.1% by weight, the effect on the dispersibility of various additives is insignificant, resulting in a poor appearance of the composition and extrusion with a high-voltage silicone cable. When it exceeds 3.5% by weight, slip occurs in the screw when extruding the high voltage silicone cable, and the outer diameter is not uniform due to the uneven extrusion amount.

The heat-resistant enhancer may be a silicon gum containing cerium hydroxide.

If the content of the heat-resistant enhancer in the silicone rubber composition is less than 0.92% by weight, dispersibility is reduced to a very small amount, so that a required heat resistance of 180°C cannot be obtained, and when the heat-resistant enhancer exceeds 3.5% by weight, It causes deterioration and the mechanical and mechanical properties are reduced.

The filler (filler) is an additive that serves to increase the mechanical properties, such as tensile strength, elongation and tear strength, silica (SiO ₂ ), calcium carbonate (CaCO ₃ ), magnesium hydroxide (Mg (OH) ₂ ) and hydro Any one selected from hydrotalcite can be used.

The hydrotalcite-type composite metal hydrate used as the filler refers to a layered composite hydroxide called anionic clay, layered double hydrate or layered mixed metal hydroxide. That is, the layered mixed metal hydroxide is a compound in the form of a hydrotalcite, and refers to a material having a structure in which anions are fixed between a layer and a layer composed of a mixed metal component and a hydroxyl group (OH-).

If the content of the filler in the silicone rubber composition is less than 0.99% by weight, there is no improvement in mechanical properties by adding the filler, and when the content of the filler is 14.3% by weight or more, problems such as tensile strength and tear strength are reduced. .

In order to achieve another object of the present invention, the high voltage silicone cable of the present invention is the silicone rubber (Silicone Rubber) 71.50 to 96.00% by weight, the crosslinking agent 0.99 to 7.20% by weight, the lubricant 0.10 to 3.50% by weight, and the heat resistance enhancer 1.92 to 3.50 as described above. The silicone rubber composition comprising weight percent and fillers 0.99 to 14.30 weight percent constitutes an insulator surrounding at least one conductor.

The high voltage silicone cable has an elongation of 675% or more, a tensile strength of 1.11 kgf/mm ² or more, and a tear strength of 57 N/mm or more according to the ASTM D624 Type C evaluation method, and shore hardness A according to the KE91110-05 evaluation method. (Shore Hardness, shore A) is characterized in that less than 60.

Description of components such as silicone rubber, crosslinking agent, lubricant, heat resistance improving agent, and filler in the silicone rubber composition used in the high voltage silicone cable of the present invention is the same as in the silicone rubber composition described above, so duplicate description will be omitted.

The thermal, mechanical, and electrical properties and effects of the high voltage silicone cable of the present invention will be described in more detail through examples to be described below.

The silicone rubber composition of the present invention as described above reflects a trend of eco-friendly automobile parts, and applies an eco-friendly flame retardant system that does not contain halogen elements, and has heat resistance and withstand voltage characteristics corresponding to 180°C cables according to ISO6722, an international standard for automobile wires. It is suitable for compact and large-capacity high-voltage cable materials for electric vehicles because it has high tensile and high tear characteristics and flexible characteristics with high mechanical properties compared to existing silicone rubber cables.

The high voltage silicone cable for electric vehicles using the silicone rubber composition having high tensile strength and high tear strength characteristics of the present invention satisfies the high voltage characteristic of 1 kV for 180°C cable based on ISO6722, compared to the existing 125°C 600V XLPE high voltage cable. It has excellent heat resistance and withstand voltage characteristics, and it is possible to reduce the size of a completed cable when applied in a vehicle due to an increase in the heat resistance rating, so it is expected to have an excellent effect on reducing the fuel efficiency of eco-friendly electric vehicles through compactness, light weight, and high capacity. do.

1 is a result of comparing the flexibility (bending force) effect of the existing XLPE high voltage cable (AHEX 40SQ) and the high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber composition of the present invention is applied.
Figure 2 is a comparison of the finished outer diameter of the existing XLPE high voltage cable (AHEX 40SQ) and a high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber composition of the present invention is applied.

Hereinafter, the present invention will be described in more detail using examples and comparative examples. However, these examples and comparative examples are only examples of the composition for the invention, and the scope of the present invention is not limited to these examples and comparative examples, and may be variously modified and changed.

As used herein, the terms “consisting of”, “comprising”, or “added” are not to be construed as including all of the various elements described in the specification, and some of them are not to be included. It may also be construed to further include additional components.

After filtering to remove foreign substances in the raw materials of the composition shown in Table 1, when the final rubber compounding agent is used in the composition and content, it is compounded by mixing through a two roll mill, etc. so that the rubber raw materials and various additives are sufficiently dispersed. Mix to mix evenly.

In Table 1 below, the crosslinking agent A contains 50% by weight of 2,4-dichlorobenzoyl peroxide in the silicone gum, and the crosslinking agent B is dicumyl in the silicone gum. It shows that 50% by weight of peroxide (dicumyl peroxide) is included.

In addition, the silica (SiO ₂ ) used as the filler in Table 1 uses an average particle size of 1 μm or less and a purity of 99.2%, and the lubricant is stearic acid based on 100% by weight of the total lubricant. 10 to 20% by weight of polydimethylsiloxane (Polydimethylsiloxane)-based silicone rubber is used, the heat-resistant enhancer was used as a silicon gum (silicone gum) containing cerium hydroxide (cerium hydroxide).

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 wt.% wt.% wt.% wt.% wt.% Suzy 1st silicone rubber 43.7 43.7 39.4 87.4 - Second silicone rubber 43.7 43.7 39.4 - 87.4 Filler Silica (SiO ₂ ) 6.5 6.5 15.6 6.5 6.5 Crosslinker Crosslinker A 2.6 - 2.4 2.6 2.6 Crosslinker B - 2.6 - - - Glide 0.9 0.9 0.8 0.9 0.9 Heat resistant improver 2.6 2.6 2.4 2.6 2.6 Total 100 100 100 100 100

In order to evaluate the properties of the silicone rubber composition prepared in Examples and Comparative Examples, a silicone rubber sheet (Sheet) was prepared through a press-crosslinking process of the silicone rubber compositions of Examples and Comparative Examples. The physical properties were evaluated, and the results are shown in Table 2 below.

Tensile strength and elongation were measured according to the evaluation method of KE91110-05, and the results are shown in Table 2 below.

The tear strength was measured according to the ASTM D624 Type C evaluation method, and the tear strength of the silicone rubber sheets of Examples and Comparative Examples was measured, and the results are shown in Table 2 below.

The volume resistance reference value is a value described in LV 216, and the volume resistance was measured for the silicone rubber sheet 100×100×2 mm ³ specimens of Examples and Comparative Examples to evaluate insulation, and the results are shown in Table 2 below.

The short-term heat resistance measurement was performed after heating for 240 hours at a temperature of 205°C according to the evaluation methods of ISO6722 and EN50363-1, and then measuring the elongation rate for a specimen maintained at -35°C for 30 minutes, and the results are shown in Table 2 below.

The heat shrinkage measurement was performed by heating the specimen at 230°C for 15 minutes according to the ISO6722 evaluation method, and measuring the length of change when placed at room temperature of 25±5°C, and the results are shown in Table 2 below.

The low-temperature impact measurement was performed after leaving the specimen at -45°C for 5 minutes according to the ISO812 evaluation method, and measuring whether the specimen was destroyed after hitting 2 m/s, and the results are shown in Table 2 below.

The hardness was measured for Shore Hardness A (shore A) according to the JIS K6253 evaluation method, and the results are shown in Table 2 below.

Odor is measured using smell, and if the smell is severe, it is indicated as'strong', and if the smell is weak, it is indicated as'about'.

Test Items Requirements Exam conditions Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Elongation (%) More than 150 KE91110-05 675 665 510 670 660 Tensile strength (kgf/mm ² ) 0.9 or higher KE91110-05 1.11 1.10 0.60 0.85 1.15 Tear strength (N/mm) 40 or more ASTM D624C 57 55 39 70 35 Volume resistance (Ω·mm) 10 ¹³ or more LV 216 1×10 ¹⁵ 1×10 ¹⁵ 1×10 ⁹ 1×10 ¹⁵ 1×10 ¹⁵ Short-term heat resistance
(%) After heating at 205℃ for 240 hours
-35℃, after standing for 30 minutes
Elongation rate over 100% ISO 6722
EN 50363-1 430 420 300 408 405 Heat shrink
(mm) 230℃, after 15 minutes
Shrink length within 2mm ISO 6722 0.3 0.5 0.3 0.4 0.4 Low temperature shock -45℃, after 5 minutes of standing
After hitting the specimen 2 m/s
No destruction ISO812 No Crack No Crack No Crack No Crack No Crack Hardness Shore A 60 or less JIS K6253 56 54 65 59 55 smell - smell about River about about about

Looking at the mechanical properties evaluation of Example 1 and Comparative Examples 1 to 4 are as follows.

Comparative Example 1 used dicumyl peroxide as a crosslinking agent, and after crosslinking, byproducts such as acetophenone, alpha-methylstyrene, and alpha-cumyl alcohol were generated. There is a serious smell.

In Comparative Example 2, the silica (SiO ₂ ) used as a filler was used in an excess of 15.6% by weight, which exceeded the amount that the silicone rubber resin can load, and the tensile and tear strengths, which are mechanical properties, did not meet the requirements. Crazy

Comparative Example 3 was evaluated using only the first silicone rubber having a tensile strength of 1.08kgf/mm ² as a resin. As a result, it can be confirmed that the tensile strength did not reach the required value. This occurs because the silicone rubber itself has a relatively low tensile strength. It is seen as a phenomenon.

Comparative Example 4 is evaluated by using only a second silicone rubber having a tensile strength of 1.22 kgf/mm ² as a resin, which has a higher tensile strength than Comparative Example 3, but confirms that the tear strength is less than 35 N/mm. This can be seen as a phenomenon that occurs because the tear strength of the silicone rubber itself is relatively low.

However, the silicone rubber composition as in Example 1 is all the values required according to the elongation, tensile strength, tear strength, volume resistance, short-term heat resistance, heat shrinkage, low temperature impact, hardness and odor presented unlike Comparative Examples 1 to 4 It was confirmed that satisfactory.

In addition, the physical properties of the insulating sheet of the existing silicone rubber cable product (FL2G 25SQ) and the properties of Example 1 are shown in Table 3 below.

Test Items Of existing products (FL2G 25SQ)
Silicone rubber insulation sheet Silicone rubber insulation sheet of Example 1 effect Heat resistance grade (℃) 180 180 Satisfaction Tensile strength (kgf/mm ² ) 0.60 1.11 Compared to existing products
85% improvement Tear strength (N/mm) 30 57 Compared to existing products
90% improvement

As shown in Table 3, the silicone rubber insulating sheet of Example 1 was compared with the silicone rubber insulating sheet of the existing silicone rubber cable product (FL2G 25SQ), and tensile strength was improved by 85% and tear strength was improved by about 90%. .

In the case of the existing silicone rubber cable product (FL2G 25SQ), the heat resistance of the insulator is excellent, but it is difficult to apply to an electric vehicle due to low tensile strength and tear strength, whereas the silicone rubber composition of Example 1 of the present invention has physical properties applicable to vehicles. Have

In addition, in order to examine the physical properties of the cable actually manufactured using the silicone rubber composition of the present invention, after extruding the silicone rubber composition of Example 1 using a silicone rubber extruder, atmospheric pressure air vulcanization (hot air vulcanization, HAV) to prepare a high voltage silicone cable (FHL2G 25SQ) and evaluate the properties, and compare the XLPE high voltage cable product (AHEX 40SQ) with the allowable current and flexibility.

The properties of the high voltage silicone cable (FHL2G 25SQ) using the silicone rubber composition of Example 1 and the comparison results with the existing XLPE high voltage cable (AHEX 40SQ) are shown in Tables 4 to 6 below.

Table 4 is a result of evaluating the physical properties of a high voltage silicone cable (FHL2G 25SQ) using the silicone rubber composition of Example 1.

Test Items Test standard/procedure Evaluation results Withstand voltage 5kV> 0.5mm ² / sample number 1,
3% NaCl x 4 hours, 1 kV x 30 minutes (500 V/s) Pass Tensile strength (kgf/mm ² ) Measurement of tensile strength at room temperature, tensile speed (250mm/min) 0.969 Elongation (%) Elongation at room temperature measurement, (250mm/min) 504 Low temperature bending (Winding) -40℃ X After 4 hours bending,
Wind 1xV×1 minute by wrapping a 5x round bar Pass Low temperature shock (Impact) 3 samples, -15℃×4hours, drop the hammer weighing 300g, there is no crack and endure 1kV×1 minute Pass Flexibility (N) 400mm sample based on 25SQ,
Measure the maximum load (N) from the round bar to 100mm/min at a speed of 80mm to 40mm. 8 Heat denaturation After heating 3 samples (600mm) 200℃×4h (weight applied),
After immersing in ice water for 10 seconds, 1kV×1 minute Pass Long-term heat resistance
(3,000 hours) After 180℃×3,000 hours, there is no crack when bending on a round rod 1.5 times the outer diameter, and it will withstand 1kV×1 minute.
Elongation, tensile residual rate should be measured Pass
Elongation residual rate: 27.7%
Tensile residual: 71.6% Short-term heat resistance
(240 hours) After 205℃×240 hours, there is no crack when bending on a round bar 5 times outside diameter, and it will withstand 1kV×1 minute.
Elongation, tensile residual rate should be measured Pass
Elongation residual rate: 66.7%
Tensile residual: 121.5% Heat shrink Not exceed 2mm
Length measurement at room temperature, re-measurement after 230℃×15 minutes 0 Thermal overload
(Thermal overload) After bending at 230℃ for 6 hours, 1kV × 1 minute Pass Long-term chemical resistance
(1,000 hours) After soaking for 10 seconds in the prescribed oil, after 180℃×1,000 hours
1kV×1 minute Pass Short term chemical resistance
(240 hours) After soaking for 10 seconds in the prescribed oil, after 180℃×240 hours
1kV×1 minute Pass Ozone resistance Wrap on a standard round bar and check the hook rack left in the ozone chamber for 192 hours Pass Flame retardant
(Within 70 seconds) Apply flame for 30 seconds, extinguish within 70 seconds, and remain at least 50 mm from the sample 1s/480mm

Table 5 compares the properties of the allowable current and flexibility for the existing XLPE high voltage cable product (AHEX 40SQ) and the high voltage silicone cable (FHL2G 25SQ) using the silicone rubber composition of Example 1, wherein the allowable current Is the permissible current measured at an ambient temperature of 80℃, and the bending force is to measure the force required for bending the cable and to maintain the flexibility of the highly flexible cable. After fixing to the jig of the flexibility measuring device so that the radius is 80 mm, the load cell is lowered at a rate of 100 mm/min to measure the maximum load (N) until the bending radius becomes 40 mm. Did.

Test Items Original product
(AHEX 40SQ) The present invention
(FHL2G 25SQ) effect Allowable current (A) 210 209 Compared to existing products
Equivalent electrical performance Flexibility (N) 28 8 Compared to existing products
71.4% improvement

As shown in Table 5 above, the high-voltage silicone cable (FHL2G 25SQ) using the silicone rubber composition of Example 1 has an equal current level compared to the existing XLPE high-voltage cable (AHEX 40SQ), and the conductor cross-sectional area is reduced from 40SQ to 25SQ. Even if it can be confirmed that it has an equivalent allowable current value.

1 is a result of comparing the flexibility (bending force) effect of the existing XLPE high voltage cable (AHEX 40SQ) and the high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber composition of the present invention is applied, as shown in FIG. 1, the existing XLPE high voltage The flexibility (bending force) of the cable (AHEX 40SQ) is 28 N, but the flexibility (bending force) of the high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber according to the present invention is applied decreases to 8 N, confirming that the flexibility is improved by 71.4%. Can.

Test Items Original product
(AHEX 40SQ) The present invention
(FHL2G 25SQ) effect Finished outer diameter (mm) 12 9 Compared to existing products
25% finished outer diameter
Size reduction effect Weight (g/m) 433 274 Compared to existing products
36% reduction

In addition, as shown in Table 6 and FIG. 2, as a result of comparing the finished outer diameter and weight of the existing XLPE high voltage cable (AHEX 40SQ) and the high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber composition of the present invention is applied, an embodiment of the present invention The high voltage silicone cable (FHL2G 25SQ) to which the silicone rubber composition according to 1 is applied has better silicone rubber (180℃ class) than XLPE cable (125℃ class) than conventional products (AHEX 40SQ), reducing conductor size (down sizing) ) As the effect, the finished outer diameter is reduced, and accordingly, it can be confirmed that the weight is reduced by about 36%.

Here, the term “finished outer diameter” means the overall diameter of the finished product of the cable.

As compared with the examples and comparative examples described above, the high voltage silicone cable using the silicone rubber composition according to the present invention uses a low hardness silicone rubber as a base resin, a crosslinking agent, a lubricant, a heat resistance improving agent and a filler. By implementing the high tensile strength and high tear properties of silicone rubber through optimization of the formulation, it is possible to provide a silicone rubber cable for a robust high voltage wiring harness that can overcome the technical limitations of compactness, light weight, and high capacity of electric vehicles.

In addition, the silicone rubber composition of the present invention has a Shore Hardness A (Shore Hardness, shore A) of 60 or less, and is characteristic of excellent room temperature flexibility and cold resistance due to its unique low hardness, and is suitable for use in vehicle mounting and low temperature environments, It is excellent in oil resistance, so it is not possible for vehicle oil to penetrate, so it can be used safely in vehicles.

Claims (7)

Silicone Rubber 71.50 to 96.00% by weight;
Crosslinking agent 0.99 to 7.20 wt%;
Lubricant 0.10 to 3.50% by weight;
Heat resistance improver 1.92 to 3.50% by weight; And
Silicone rubber composition comprising a filler; 0.99 to 14.30% by weight. According to claim 1,
The silicone rubber,
A first silicone rubber having a tensile strength of 1.08 kgf/mm ² or more and a Shore Hardness A (shore A) of 57 or less; And
A second silicone rubber having a tensile strength of 1.22 kgf/mm ² or more and Shore Hardness A (shore A) of 53 or less; Silicone rubber composition, characterized in that any one or two selected from the mixture. According to claim 1,
The crosslinking agent,
2,4-dichlorobenzoyl peroxide, benzoyl peroxide 2,5-dimethyl-2,5-bis-(tert-butylperoxy)-hexane (2,5- Silicone rubber composition, characterized in that at least one selected from dimethyl-2,5-bis-(tert-butylperoxy)-hexane), bis(4-methylbenzoyl)peroxide. According to claim 1,
The lubricant,
A silicone rubber composition characterized in that it is a polydimethylsiloxane-based silicone rubber containing 10 to 20% by weight of stearic acid based on 100% by weight. According to claim 1,
The heat-resistant enhancer,
Silicone rubber composition characterized in that it is a silicon gum (silicone gum) containing cerium hydroxide (cerium hydroxide). According to claim 1,
The filler,
Silicone rubber composition, characterized in that any one selected from SiO ₂ , CaCO ₃ , Mg(OH) ₂ and hydrotalcite. High voltage silicone cable, characterized in that the silicone rubber composition of any one of claims 1 to 6 constitutes an insulator surrounding at least one conductor.

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