KR20210120460A - Fluororesin insulating composition having execellent heat resistance and flexibility and a cable comprising the same - Google Patents

Abstract

The present invention relates to a fluororesin insulating composition and a cable comprising the same. The fluororesin insulating composition according to the present invention can simultaneously satisfy heat resistance and flexibility. In addition, the fluororesin insulating composition according to the present invention has excellent cold resistance, hardness, tensile strength, and the like, and thus can provide the high quality fluororesin insulating composition.

Description

Fluororesin insulation composition with excellent heat resistance and flexibility, and a cable comprising the same

The present invention relates to a fluororesin insulating composition having excellent heat resistance and flexibility, and a cable comprising the same.

The engine room of a vehicle is an environment exposed to high temperatures, and accordingly, parts requiring high heat resistance are used. Automotive cables also require higher high-temperature characteristics compared to other cables, and must be made of materials with a continuous use temperature of 150℃ (T4 class) or higher in consideration of harsh conditions such as hot regions or summer. In addition, since the engine room with a narrow space is an environment in which cables are installed in a bent and bent form in order to properly arrange various parts, flexibility is fundamentally required.

In particular, electric vehicles were produced in small quantities in the United States until the mid-1920s due to their simple structure, durability, and ease of operation. Electric vehicles are attracting attention as next-generation vehicles due to rising oil prices and rising oil prices. In other words, electric vehicles using non-polluting electric energy can fundamentally solve environmental problems such as harmful exhaust gas and noise of internal combustion engine vehicles, which account for around 70% of air pollution factors. It is possible to extend the lifespan of a resource by more than double, so its widespread use is rapidly taking place.

In the case of such an electric vehicle, as the capacity of a high-voltage battery applied instead of an engine increases and various electrical system components increase, the cables used require higher heat resistance and flexibility characteristics.

On the other hand, polyethylene, polypropylene, polyvinyl chloride, etc., which are generally used as insulation materials for cables focusing on flexibility, have insufficient heat resistance and chemical resistance to be applied as insulation materials for high heat-resistant cables. In this required use, a cable having a heat resistance rating of T4 to T6 class by applying silicone or fluororesin is used.

On the other hand, recently, in order to improve the processability of the fluororesin, a fluorine copolymer or a terpolymer to which a monomer capable of lowering the melting temperature is applied has been used, but these conventionally known compositions have any one of heat resistance, chemical resistance, flexibility, cold resistance, and flame retardancy. There is a problem in that the above physical properties are insufficient and the manufacturing cost of the composition is increased.

For example, an insulating composition designed in consideration of heat resistance and abrasion resistance has a limit in flexibility, which is the opposite characteristic.

Accordingly, the present invention solves the above problems, and there is an urgent need for an insulating composition having high heat resistance and high flexibility.

In order to solve the problems of the prior art, the present inventors, by combining the base resin in a specific content, satisfy the high heat resistance of 200°C (T6 class) without increasing the manufacturing cost, and a fluororesin insulating composition with significantly improved flexibility compared to the conventional cable and a cable including the same.

In addition, the present invention is to provide a fluororesin insulating composition excellent in abrasion resistance and cold resistance in addition to the above properties.

The present invention, in order to solve the above-mentioned problems,

ethylene vinyl acetate rubber; a first fluororesin having a melting point of 120°C to 150°C; And it provides a fluororesin insulating composition comprising a base resin comprising a second fluororesin having a melting point of 160°C to 180°C.

In addition, the present invention provides a fluororesin insulating composition, wherein the base resin further comprises a fluoroelastomer.

In addition, the present invention, the base resin, ethylene vinyl acetate rubber 0.1% to 10% by weight; 30% to 60% by weight of a fluoroelastomer; 5 wt% to 20 wt% of a first fluororesin having a melting point of 120 to 150°C; And it provides a fluororesin insulating composition comprising 30% to 50% by weight of a second fluororesin having a melting point of 160 to 180°C.

In addition, the present invention provides a fluororesin insulating composition, characterized in that the ethylene vinyl acetate rubber is contained in an amount of 5 wt% to 10 wt% based on the total weight of the base resin.

In addition, the present invention provides a fluororesin insulating composition, characterized in that the fluoroelastomer is a binary (VDF+HFP) fluororubber of vinylidene fluoride (VDF) and hexafluoropropylene (HFP).

In addition, the present invention provides a fluororesin insulating composition, characterized in that the fluoroelastomer has a Mooney viscosity (ML1+10 (121°C)) of 60MU to 70MU.

In addition, the present invention provides a fluororesin insulating composition, characterized in that the fluoroelastomer is included in an amount of 40% to 50% by weight based on the total weight of the base resin.

In addition, the present invention provides a fluororesin insulating composition, wherein the first fluororesin and the second fluororesin each contain polyvinylidene fluoride (PVDF).

In addition, in the present invention, the first fluororesin is included in an amount of 5% to 10% by weight based on the total weight of the base resin, and the second fluororesin is 30% to 45% by weight based on the total weight of the base resin. It provides a fluororesin insulating composition, characterized in that it is included in %.

In addition, the present invention provides a fluororesin insulating composition, characterized in that the total content of the first fluororesin and the second fluororesin is comprised in an amount of 40 wt% to 55 wt% based on the total weight of the base resin.

Further, in the present invention, the fluororesin insulation composition further comprises one or more additives selected from the group consisting of antioxidants, lubricants, stabilizers, fillers, plasticizers, crosslinking agents, and crosslinking aids. Fluorine resin insulation A composition is provided.

In addition, the present invention provides a fluororesin insulating composition comprising the antioxidant, a phenol-based primary antioxidant and a phosphorus-based secondary antioxidant.

In addition, the present invention provides a fluororesin insulating composition in which the phenol-based primary antioxidant and the phosphorus-based secondary antioxidant are included in a weight ratio of 1:1 to 3:1.

In addition, the present invention provides a fluororesin insulating composition in which the additive is included in a total amount of 10 to 30 parts by weight based on 100 parts by weight of the base resin.

On the other hand, the present invention is also a conductor; and an insulating layer surrounding the conductor and formed from the fluororesin insulating composition according to claim 1 .

The fluororesin insulating composition according to the present invention satisfies the high heat resistance of 200°C (T6 grade), can exhibit improved flexibility compared to the prior art, and has excellent workability, and also has excellent tensile strength, abrasion resistance and cold resistance.

Hereinafter, the fluororesin insulating composition and the cable including the same according to the present invention will be sequentially described in detail, but the scope of the fluororesin insulating composition and the cable including the same is not limited by the following description.

The present invention relates to a fluororesin insulating composition.

More specifically, the present invention relates to a fluororesin insulating composition capable of simultaneously improving heat resistance and flexibility by including a specific material in a specific content.

The fluororesin insulating composition includes: ethylene vinyl acetate rubber; A first fluororesin having a melting point of 120°C to 150°C; and a base resin comprising a second fluororesin having a melting point of 160°C to 180°C.

In addition, the base resin may further include a fluoroelastomer.

The base resin, 0.1 wt% to 10 wt% of ethylene vinyl acetate rubber; 30% to 60% by weight of a fluoroelastomer; 5 wt% to 20 wt% of a first fluororesin having a melting point of 120 °C to 150 °C; and 30% to 50% by weight of the second fluororesin having a melting point of 160°C to 180°C.

Here, when the ethylene vinyl acetate rubber is mixed with the fluororesin insulating composition, the fluoroelastomer and the fluororesin alone have low surface energy, which causes slippage and lacks sufficient frictional force, so it is preferable to be mixed for workability.

The ethylene vinyl acetate rubber is preferably contained in an amount of 0.1 wt% to 10 wt% based on the above content, that is, the total weight of the base resin, and specifically, 1 wt% or more, 3 wt% or more, 5 wt% or more Or 7% by weight or more, preferably included in 10% by weight or less.

Out of the above range, if too little is included, workability may be reduced, and if too much is included, the content of the base resin for substantially high heat resistance and high flexibility of the insulating composition, such as a fluororesin, is relatively reduced, so the abrasion resistance However, a problem in which pinch characteristics may be deteriorated may occur.

Meanwhile, the fluoroelastomer is a key material for high heat resistance and high flexibility.

More specifically, the fluoroelastomer, also called "fluororubber", is a material capable of improving physical properties such as flexibility, cold resistance and extrudability in a fluororesin insulating composition, for example, vinylidene fluoride ( VDF) and hexafluoropropylene (HFP) binary system (VDF + HFP) fluororubber, or vinylidene fluoride (VDF), hexafluoropropylene (HFP) and tetrafluoroethylene (TFE) or vinylidene fluoride ( VDF), tetrafluoroethylene (TFE) and perfluoromethylvinyl ether (PMVE) ternary (VDF+HFP+TFE, VDF+TFE+PMVE) fluororubber may be included, and in the present invention, heat resistance and flexibility In order to maximize the improvement effect of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) binary system (VDF + HFP) fluororubber can be used.

Although not particularly limited, the fluoroelastomer may have a number average molecular weight (Mn) of 90,000 to 120,000.

In addition, the Mooney viscosity (ML1+10 (121° C.)) of the fluoroelastomer may be 50MU to 80MU, specifically 60MU to 70MU.

The Mooney viscosity is obtained by using a Mooney viscometer (Alpha Technologies) at 121° C. to obtain an ML1+10 value, where M is Mooney, L means the size of the plate, 1 is the preheating time (min), 10 may mean that the value is read after 10 minutes by operating the rotor.

Out of the above range, if the number average molecular weight (Mn) is less than 90,000 or the Mooney viscosity is less than 50, the heat resistance of the fluororesin insulating composition may be deteriorated, and the number average molecular weight is more than 120,000 or the Mooney viscosity is more than 80 In this case, there may be problems in that physical properties such as flexibility, cold resistance and extrudability of the fluororesin composition may be deteriorated.

As described above, the fluoroelastomer is preferably included in an amount of 30 wt% to 60 wt% based on the total weight of the base resin, and more specifically, 35 wt% or more, or 40 wt% or more, and may be 55 wt% % or less, or 50 wt% or less.

When the content of the fluoroelastomer is less than 30% by weight, there may occur a problem that physical properties such as flexibility, cold resistance, and extrudability of the fluororesin insulating composition may be reduced, and if it exceeds 60% by weight, the fluororesin insulating composition There may be problems in that physical properties such as hardness and abrasion resistance may be deteriorated.

On the other hand, the fluororesin is a high heat-resistance resin for mixing with the fluoroelastomer, and two types of fluororesins having different melting points may be included together.

When two types of fluororesins having different melting points are included as described above, flexibility and heat resistance can be improved, and additional physical properties such as tensile strength and hardness can be improved, whereas when only one fluororesin is included There may be problems that may be difficult to commercialize due to low tensile strength and hardness.

Here, the first fluororesin and the second fluororesin are not particularly limited, but for example, may be materials of the same composition having different melting points, and more specifically, include a homopolymerized fluororesin or a block/random copolymerized fluororesin. can do.

More specifically, the first fluororesin and the second fluororesin include, for example, polyvinyldenefluoride (PVDF), or vinylidenefluoride (VDF) and hexafluoropropylene ; HFP), tetrafluoroethylene (TFE), chlorotetrafluoroethylene (CTFE), perfluoromethylvinylether (perfluoromethylvinylether; PMVE), etc. copolymer resin with one or more monomers selected from the group consisting of may include, and more preferably, polyvinyldenefluoride (PVDF).

The first fluororesin and the second fluororesin that may be included in the present invention may have different physical properties, such as melting point and flexural modulus.

For example, the first fluororesin may be a material having a melting point of 120°C to 150°C and a flexural modulus of 600Mpa to 800Mpa, and the second fluororesin has a melting point of 160°C to 180°C, and a flexural modulus of It may be a material of 200 Mpa to 400 Mpa.

When fluororesins of different melting points are mixed as described above, processability and heat resistance of the fluororesin insulating composition can be secured at the same time. Specifically, by using a material having a melting point of 120° C. to 150° C. and a flexural modulus of 600 Mpa to 800 Mpa, it is possible to increase flexibility while securing workability by lowering the melting temperature, and the melting point is 160° C. to 180° C., and flexural modulus By using this 200Mpa to 400Mpa material, it may be possible to improve hardness while securing high heat resistance properties.

When considering the properties such as heat resistance, flexibility, tensile strength and hardness, the first fluororesin may be included in an amount of 5 wt% to 20 wt%, more preferably 5 wt% to 10 wt%, based on the total weight of the base resin. and the second fluororesin may be included in an amount of 30 wt% to 50 wt%, more preferably 30 wt% to 45 wt%, based on the total weight of the base resin.

When the content of the first fluororesin exceeds 20% by weight or the content of the second fluororesin is included in less than 30% by weight, there may be problems that heat resistance and flexibility may be lowered, and the first fluororesin may contain less than 30% by weight. When the content is less than 5% by weight or the content of the second fluororesin is more than 50% by weight, the flexibility of the fluororesin insulating composition may be increased, but there may be problems that the tensile strength and elongation may be reduced.

In addition, the total content of the first fluororesin and the second fluororesin may be included in an amount of 35 wt% to 70 wt%, more preferably 40 wt% to 55 wt%, based on the total weight of the base resin.

Out of the above range, if the total content of the first fluororesin and the second fluororesin is less than 35% by weight based on the total weight of the base resin, there may be a problem that the heat resistance of the fluororesin insulating composition may be lowered. And, when it is included in more than 70% by weight, there may be problems that the flexibility and extrudability of the fluororesin insulating composition may be lowered.

Additionally, the fluororesin insulating composition may further include one or more additives selected from the group consisting of antioxidants, lubricants, stabilizers, fillers, plasticizers, processing aids, crosslinking agents, and crosslinking aids in addition to the base resin.

The antioxidant performs a function of preventing deterioration of the ethylene vinyl acetate rubber, which has relatively low heat resistance.

The antioxidant is not particularly limited, but for example, a phenol-based primary antioxidant and a phosphorus-based secondary antioxidant may be used together.

The phenolic primary antioxidant may prevent oxidation of the final product, and the phosphorus secondary antioxidant may prevent aging due to heat that may occur during processing of a product including the composition.

When the phenolic primary antioxidant and the phosphorus secondary antioxidant are included and used simultaneously, the phenolic primary antioxidant and the phosphorus secondary antioxidant may be included in a weight ratio of 1:1 to 3:1, respectively, More preferably, it may be included in a weight ratio of 1.5:1 to 2:1.

Out of the above range, if too little of the phenolic primary antioxidant is included as compared to the phosphorus secondary antioxidant, there may be a problem in that the antioxidant function of the final product is lowered, and the phenolic primary antioxidant is When too much of the phosphorus-based secondary antioxidant is included compared to the phosphorus-based secondary antioxidant, the content of the phosphorus-based secondary antioxidant is relatively reduced, so that there may be a problem of aging due to heat that may occur during processing of a product including the composition.

The total content of the antioxidant performing this function may be included in an amount of 0.5 parts by weight to 1.5 parts by weight based on 100 parts by weight of the base resin.

The lubricant serves to maintain the physical properties, particularly the elongation, after heating of the fluororesin insulating composition. Conventional lubricants such as polyethylene wax may disappear upon heating. It is preferable to include a fluorine-containing lubricant capable of maintaining elongation, for example, a fluorinated olefin-based lubricant.

The amount of the lubricant may be 0.3 parts by weight to 1 part by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

The stabilizer may include, for example, calcium hydroxide, aluminum oxide, zinc oxide, magnesium oxide, etc. as a processing aid, and more preferably calcium hydroxide.

The content of the stabilizer may be 3 parts by weight to 8 parts by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

The filler may serve to improve the processability of the fluororesin insulating composition by increasing the friction coefficient of the composition, and may include, for example, talc, calcium carbonate, silica or clay. , preferably a mixture of silica and kaolinite, and may include a filler coated with vinyl silane.

The content of the filler may be 3 parts by weight to 10 parts by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

The plasticizer may be added to further improve the cold resistance and extrudability of the fluororesin insulating composition, for example, a phthalic acid ester-based, aliphatic dibasic acid ester-based, polyester-based, epoxy-based plasticizer, etc. may be used. , may be added in an amount of 1 to 4 parts by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

The crosslinking agent can improve room temperature physical properties, especially tensile strength and heat resistance, of the fluororesin insulating composition through the "chemical crosslinking" method or "irradiation crosslinking" method of the fluororesin, and in particular, it can be used in the "chemical crosslinking" method The type of cross-linking agent is not particularly limited, but, for example, an amine-based cross-linking agent, a silane-based cross-linking agent, a polyol-based cross-linking agent, or a peroxide-based cross-linking agent may be used.

The amount of the crosslinking agent may be added in an amount of 1 to 3 parts by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

In addition, if you want to improve the physical properties of the fluororesin by "irradiation crosslinking" method, a crosslinking aid can be used among additives, and the room temperature physical properties, especially tensile strength and heat resistance, of the fluororesin insulating composition can be improved through the crosslinking aid. In this case, the type of crosslinking aid that can be used is not particularly limited, but for example, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC), trimethylolpropane trimethacrylate ( TMPTMA) or trimethylolpropane triacrylate (TMPTA) may be used.

In addition, the content of the crosslinking aid may be added in an amount of 1 to 5 parts by weight based on 100 parts by weight of the base resin, but is not particularly limited thereto.

Meanwhile, the total content of the above-described additives may be 10 parts by weight to 30 parts by weight based on 100 parts by weight of the base resin.

Out of the above range, when the content of the additive is included too little, a problem may occur that the effect of the additives is insignificant, and when the content of the additive is included too much, the relative content of resin and rubber is reduced. As a result, a problem may occur in realization of physical properties.

The present invention also provides a conductor; and an insulating layer surrounding the conductor and formed from the fluororesin insulating composition.

The conductor may have a composite stranded wire structure made by twisting a plurality of metal wires at a constant pitch, and the metal wire may be made of a single metal or at least two or more metal alloys. That is, the metal wire may be made of a metal selected from copper, aluminum, iron, and nickel or an alloy of these metals, but is not particularly limited thereto.

The insulating layer is formed from the above-described insulating composition according to the present invention so as to surround the outside of the conductor, and a detailed description thereof is the same as described above, and thus, a detailed description thereof will be omitted.

Hereinafter, the present invention will be described in more detail through specific experimental examples. However, these experimental examples are for illustrative purposes only and the scope of the present invention is not limited to these experimental examples.

[Experimental design and composition preparation]

A fluororesin insulating composition was prepared with the composition shown in Table 1 below.

For the experimental sample, the combination of each composition shown in Table 1 is mixed through a Two-Roll Mill or a Kneader, and pressurized at 200° C. for 10 minutes using a press to make a sheet or to a sheet form using a Haake extruder. After extruding, various evaluations were performed by manufacturing a specimen on a dumbbell.

As the main evaluation items, specific gravity, room temperature tensile strength/elongation, 2% secant modulus, 5% secant modulus, heat tensile residual ratio and heat elongation residual ratio were evaluated, and hardness and low temperature impact level were evaluated as other characteristics. Heat evaluation was compared by accelerated aging under conditions of 250°C/24 hours instead of 225°C/96 hours.

division comparative example Example One 2 3 4 5 6 7 8 9 10 One 2 3 4 resin 1 5 5 5 10 10 10 10 10 10 10 10 10 10 10 resin 2 35 40 45 30 30 30 30 30 50 40 40 40 40 40 resin 3 60 55 50 60 30 - 60 60 - - 20 5 10 10 resin 4 - - - - 30 60 - - 40 50 30 45 40 40 Antioxidant 1 One One One One One One 0.5 One 0.5 One One One One 0.5 Antioxidant 2 - - - - - - 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Antioxidant 3 - - - - - - - - 0.5 0.5 - - - 0.5 Stabilizer 1 4 4 4 4 4 4 4 4 4 - - - 4 4 Stabilizer 2 2 2 2 2 2 2 2 2 2 5 5 5 2 2 processing lubricant 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 filler 8 8 8 8 8 8 8 8 8 8 8 8 8 8 plasticizer 3 3 3 3 3 3 3 3 3 3 3 3 3 3 crosslinking aid 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 crosslinking agent 3 3 3 3 3 3 3 3 3 3 3 3 3 3 *Resin 1: Ethylene vinyl acetate rubber with VA content of 70wt%
*Resin 2: It is a binary fluororubber with VDF+HFP structure, and has a Mooney viscosity (ML1+10 (121℃)) of 62MU.
*Resin 3: PVDF resin with a melting point of 140°C and a flexural modulus of 750 MPa
*Resin 4: PVDF resin with a melting point of 165℃ and a flexural modulus of 250MPa
*Antioxidant 1: Phenolic primary antioxidant
*Antioxidant 2: Phosphorus-based secondary antioxidant
*Antioxidant 3: Phosphorus-based secondary antioxidant
*Stabilizer 1: Calcium hydroxide
*Stabilizer 2: Zinc Oxide
*Processing lubricant: FPA (Fluorinated processing aid)
*Filler: Silica coated with vinylsilane
*Plasticizer: dioctyl sebacate plasticizer
*Crosslinking aid: TAIC (Triallyl isocyanurate)
*Crosslinking agent: peroxide-based crosslinking agent

[Evaluation of physical properties]

The physical property evaluation was performed as follows, and the results of the physical property evaluation are shown in Table 2 below.

1. Room temperature properties (tensile strength/elongation)

The dumbbell-like tensile strength/elongation of the insulating composition was measured according to the IEC 60811-1-1 standard, and the length of the dumbbell part was 20mm, the width was 4mm, and the tensile speed was evaluated as 250mm/min. Evaluation criteria should be a tensile strength of 1.4kgf/mm ² or more and an elongation of 300% or more.

2. 2% and 5% secant modulus (flexibility)

It proceeds in the same manner as the room temperature physical property evaluation, but the tensile strength corresponding to the elongation of 2% and 5%, respectively, was measured. As for the evaluation criteria, the 2% modulus should be 0.3 kgf/mm ² or less and the 5% modulus ^{should be 0.4 kgf/mm 2} or less.

3. Physical properties after heating (residual tensile rate and elongation residual rate)

Tensile test conditions were the same as at room temperature, but the dumbbell-shaped specimen was placed in an oven at 250° C. in advance for 24 hours, and then it was taken out and left at room temperature for 12 hours before evaluation. The evaluation criteria should be 60% or more in both the heating and tensile residual ratio and the heating extension residual ratio.

4. Cold Strike (Cold Resistance)

In accordance with ASTM D746 standard, evaluation of cold-resistant hitting on dumbbells was performed. Five specimens prepared with a thickness of 2 mm were left at -20°C for 4 minutes, and then using a striking edge at a speed of 1800 mm/s to 2200 mm/s at a 90 degree angle to the surface of the specimen. The number of cracks/breaks/cuts was determined visually. As for the evaluation criteria, there should be no cracks/breaks/cuts when observed with the naked eye.

5. Hardness (wear resistance)

It was evaluated by the Shore A method using a durometer. The evaluation criteria should be 80 or higher.

division condition comparative example Example One 2 3 4 5 6 7 8 9 10 One 2 3 4 Hardness (shore A) RT 93.
48 91.
54 91.6 88.
78 88.
26 83.
46 91.46 94.
76 78.
68 78.
66 85.
13 84.
99 84.
86 85.
01 Seal
burglar
(kgf/mm ² ) RT 1.731 1.453 1.218 1.648 1.415 0.977 2.080 1.812 1.152 1.5
81 1.5
231 1.4000 1.4132 1.4
212 Elongation (%) RT 463.85 423.39 428.9 324.11 323.69 242.92 386.9 347.93 440.25 490.4 450.25 302.41 430.1 406.13 2% secant modulus
(kgf/mm ² ) RT 0.55 0.462 0.355 0.481 0.350 0.222 0.474 0.545 0.155 0.252 0.293 0.236 0.261 0.267 5% secant modulus
(kgf/mm ² ) RT 0.698 0.589 0.459 0.628 0.454 0.290 0.635 0.693 0.201 0.309 0.397 0.311 0.349 0.36 heating
Seal
balance
(%) 250℃
(24 hours) 84.46 82.73 93.35 100.97 107.77 101.74 92.84 105.24 76.51 92.41 100.35 105.47 103.66 98.38 heating
kidney
balance
(%) 250℃
(24 hours) 23.
97 36.
92 42.39 16.
43 39.
33 35.
22 48.51 43.
82 61.
88 62.19 60.
11 65.
84 61.5 60.
84 cold weather
blow crack
(Count) -20℃
(4 minutes) 0 0 0 2 0 0 One 0 0 0 0 0 0 0 cold weather
damage
fracture
(Count) -20℃
(4 minutes) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 cold weather
damage
cut
(Count) -20℃
(4 minutes) 5 5 5 0 0 0 0 0 0 0 0 0 0 0

Referring to Table 2, in the case of Examples 1 to 5, compared to Comparative Example 4, which is a configuration used for a conventional vehicle cable for an internal combustion engine, 5% Secant modulus is about twice as flexible as 40 to 60%, and heat elongation It can be seen that the residual ratio is improved by about 45%, so that the heat resistance is also very excellent.

In addition, when Comparative Examples 1, 2, and 3 were compared with each other, as the ratio of Resin 2 increased, the Secant modulus was lowered to become flexible, and the heat resistance was improved by increasing the residual heating elongation. However, in Comparative Examples 1, 2 and 3, as the content of Resin 1 was blended at 5 wt%, it took a lot of time to generate heat, and it was confirmed that the processability was poor due to the slip phenomenon with the equipment during extrusion. In addition, it was confirmed that the flexibility was not good and the heat resistance was also inferior.

In addition, in Comparative Examples 4, 5 and 6, the amount of Resin 1 was increased to 10% by weight to improve workability, and when comparing Comparative Examples 4, 5, and 6 with each other, the flexural modulus was about 1/3 level compared to Resin 3 As the ratio of phosphorus resin 4 increased, the secant modulus value was remarkably decreased and it was found to be flexible, but it was confirmed that the tensile strength and hardness also decreased. In addition, it was confirmed that the residual heating elongation rate was still too low to be applied to products.

In addition, in the case of Comparative Examples 7 and 8, the physical properties and hardness at room temperature satisfied the evaluation criteria, and it was confirmed that the heating elongation residual rate was improved due to the compatibility of the antioxidants 1 and 2, but the 2% Secant modulus value was 0.4 kgf / mm ² to 0.6kgf/mm ² As compared to the Examples, it was confirmed that the flexibility was about twice as low. In addition, in order to simultaneously improve flexibility and heat resistance, it was confirmed that it is preferable to use two types of PVDF having different melting points and to include a resin 2 content higher than 30% by weight.

In addition, when comparing Comparative Examples 9 and 10 with each other, the 2% Secant modulus value ^{was lowered to 0.2kgf/mm 2} level through mixing of Resin 2 and Resin 4 and adjusting the stabilizer and processing aid, maximizing flexibility and heating elongation residual rate of 60 % or more, the heat resistance was greatly improved, but in Comparative Examples 9 and 10, it was confirmed that it was difficult to commercialize at a level where the physical properties at room temperature were insufficient due to the absence of the resin 3 having a high flexural modulus, and the hardness was also lowered.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present application.

Claims (15)

A fluororesin insulating composition comprising:
ethylene vinyl acetate rubber;
a first fluororesin having a melting point of 120°C to 150°C; and
A fluororesin insulating composition comprising a base resin comprising a second fluororesin having a melting point of 160°C to 180°C.
The fluororesin insulating composition according to claim 1, wherein the base resin further comprises a fluoroelastomer.
According to claim 2, wherein the base resin,
0.1% to 10% by weight of ethylene vinyl acetate rubber;
30% to 60% by weight of a fluoroelastomer;
5 wt% to 20 wt% of a first fluororesin having a melting point of 120 to 150°C; and
A fluororesin insulating composition comprising 30% to 50% by weight of a second fluororesin having a melting point of 160 to 180°C.
The fluororesin insulating composition according to claim 2, wherein the ethylene vinyl acetate rubber is included in an amount of 5 to 10 wt% based on the total weight of the base resin.
The fluororesin insulating composition according to claim 2, wherein the fluoroelastomer is a binary (VDF+HFP) fluororubber of vinylidene fluoride (VDF) and hexafluoropropylene (HFP).
The fluororesin insulating composition according to claim 2, wherein the fluoroelastomer has a Mooney viscosity (ML1+10 (121°C)) of 60MU to 70MU.
[3] The fluororesin insulating composition according to claim 2, wherein the fluoroelastomer is included in an amount of 40 wt% to 50 wt% based on the total weight of the base resin.
The fluororesin insulation composition according to claim 1, wherein the first fluororesin and the second fluororesin each contain polyvinylidene fluoride (PVDF).
The method according to claim 2, wherein the first fluororesin is included in an amount of 5 wt% to 10 wt% based on the total weight of the base resin, and the second fluororesin is 30 wt% to 45 wt% based on the total weight of the base resin. % of the fluororesin insulating composition.
The fluororesin insulating composition according to claim 2, wherein the total content of the first fluororesin and the second fluororesin is 40 wt% to 55 wt% based on the total weight of the base resin.
11. The method according to any one of claims 1 to 10, wherein the fluororesin insulating composition comprises at least one additive selected from the group consisting of antioxidants, lubricants, stabilizers, fillers, plasticizers, processing aids, crosslinking agents, and crosslinking aids. Fluorine resin insulation composition, characterized in that it further comprises.
The fluororesin insulation composition according to claim 11, wherein the antioxidant comprises a phenol-based primary antioxidant and a phosphorus-based secondary antioxidant.
The fluororesin insulating composition according to claim 12, wherein the phenol-based primary antioxidant and the phosphorus-based secondary antioxidant are included in a weight ratio of 1:1 to 3:1.
The fluororesin insulating composition according to claim 11, wherein the additive is included in a total amount of 10 to 30 parts by weight based on 100 parts by weight of the base resin.
conductor; and
A cable surrounding the conductor and comprising an insulating layer formed from the fluororesin insulating composition according to claim 1 .