KR102160312B1 - Fluororesin composition with excellent wear-resistance, and low voltage cable having a dielectric layer made from the same - Google Patents

Abstract

The present invention relates to a low-voltage electric wire including a fluororesin composition excellent in both heat resistance and abrasion resistance, and an insulating layer formed therefrom. Specifically, the present invention is a fluororesin composition having improved flexibility, cold resistance, flame retardancy, processability, etc., and at the same time excellent in both heat resistance, chemical resistance, and abrasion resistance in conflict with it so that it can be used as an insulating layer material for high heat-resistant wires. It relates to a low-voltage electric wire including an insulating layer formed from.

Description

Fluororesin composition with excellent wear-resistance, and low voltage cable having a dielectric layer made from the same}

The present invention relates to a low-voltage electric wire comprising a fluororesin composition having excellent wear resistance and an insulating layer formed therefrom. Specifically, the present invention is fluorine having excellent heat resistance and chemical resistance, excellent flexibility and abrasion resistance in conflict with it, and additionally improved cold resistance, flame resistance, and workability so that it can be used as an insulating layer material for high heat-resistant wires. It relates to a low-voltage electric wire comprising a resin composition and an insulating layer formed therefrom.

Electric wires for fuel pumps of automobiles, tubes for defense, etc. can be made of highly heat-resistant materials since the continuous use temperature is 200°C or higher.

1 is a schematic cross-sectional view of a T6 class high heat-resistant wire that can be used as a wire for the fuel pump for an automobile. As shown in FIG. 1, the T6 class high heat-resistant wire may be made of a plurality of stone conductors 10 and an insulating layer 20 of a high heat-resistant material surrounding them, and an insulating material forming the insulating layer 20 Is required for high heat resistance.

In particular, when a T6 class high heat-resistant wire is used as a high heat-resistant wire for an automobile, the insulating material forming the insulating layer 20 must satisfy heat resistance and chemical resistance according to standards ARX-9 and ISO 6722, and In a convection oven maintained at 225±1.0℃ for 10 days, a heat-resistance test should be conducted to satisfy the specified standard values for tensile strength and elongation (tensile strength residual ratio of 50% or more, elongation residual ratio of 60% or more). The external diameter change rate should not exceed 25% by conducting a chemical resistance test for 240 hours in a convection oven at 150℃ while immersed in transmission oil.

In addition, the insulating material forming the insulating layer 20 is heated in an oven at 225°C for 10 days in the state of an electric wire surrounding the conductor, and the withstand voltage evaluation proceeds after bending and heating in an oven at 250°C for 1 hour and then bending. All of the withstand voltage evaluation must be satisfied, and other specifications such as flexibility, pinch characteristics, cold resistance, and flame retardancy must be satisfied.

Polyethylene, polypropylene, polyvinyl chloride, etc., which are generally used as insulation layer materials of conventional electric wires, are insufficient in heat resistance and chemical resistance to be applied as insulation layers of high heat resistant electric wires, so such high heat resistance and high chemical resistance are required. In the application, fluororesin is used.

While the fluororesin exhibits excellent high heat resistance and chemical resistance, it is difficult to process due to its high melting temperature, and also has a problem of inferior flexibility because of its high hardness, so that when applied to wires or tubes, wiring work may become difficult.

Meanwhile, in order to improve the processability of the fluororesin, a fluorine copolymer or terpolymer to which a monomer capable of lowering the melting temperature is applied may be used, but at least one of heat resistance, chemical resistance, flexibility, cold resistance, and flame retardancy Physical properties may be insufficient.

In addition, a technique of adding fluorine rubber to improve the flexibility of the fluororesin is known, but the flexibility is improved to some extent by the addition of the fluorine rubber, but there is a problem that abrasion resistance is greatly reduced.

Therefore, there is an urgent need for a fluororesin composition having excellent heat resistance, chemical resistance, and abrasion resistance in conflict with it so that it can be applied to the insulating layer of high heat-resistant wires, and with improved flexibility, cold resistance, flame resistance, and workability. to be.

An object of the present invention is to provide a fluororesin composition having excellent heat resistance and chemical resistance, and excellent both flexibility and abrasion resistance in conflict with this.

In addition, an object of the present invention is to provide a fluororesin composition having additionally improved cold resistance, flame retardancy, processability, etc. required for use as an insulating layer for high heat-resistant electric wires for automobiles.

Further, an object of the present invention is to provide a low-voltage electric wire having an insulating layer formed from the fluororesin composition.

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

50 to 70 parts by weight of a fluorine copolymer having a melting point of 100 to 155°C, 25 to 45 parts by weight of the first fluorine rubber, and a number average molecular weight (Mn) that is 50,000 to 150,000 larger than the number average molecular weight (Mn) of the first fluorine rubber A base resin comprising 3 to 10 parts by weight of a second fluororubber having; And, based on 100 parts by weight of the base resin, 3 to 7 parts by weight of a fluorine-containing processing aid, 3 to 6 parts by weight of a plasticizer, and 1 to 5 parts by weight of a crosslinking agent to provide a fluororesin composition.

In addition, the fluorine copolymer provides a fluororesin composition, characterized in that it comprises a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP).

In addition, the first fluororubber has a number average molecular weight (Mn) of 90,000 to 120,000, and the second fluororubber has a number average molecular weight (Mn) of 150,000 to 300,000.It provides a fluororesin composition.

Here, the first fluorine rubber and the second fluorine rubber are binary (VDF+HFP) fluorine rubber of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), vinylidene fluoride (VDF), and hexafluoro, respectively. Ternary (VDF+HFP+TFE) fluororubber of low propylene (HFP) and tetrafluoroethylene (TFE), or vinylidene fluoride (VDF), tetrafluoroethylene (TFE) and perfluoromethylvinyl ether ( It provides a fluororesin composition comprising a ternary (VDF+TFE+PMVE) fluororubber of PMVE).

In addition, it provides a fluorine resin composition, characterized in that the fluorine content (F contents) of the first fluorine rubber and the second fluorine rubber is 60 to 70%.

On the other hand, it provides a fluororesin composition, characterized in that the 5% secant modulus is 15 kgf / mm 2 or less.

In addition, the fluorine-containing processing aid provides a fluorine resin composition, characterized in that it comprises a fluorinated olefin-based processing aid.

And, the plasticizer provides a fluororesin composition, characterized in that it comprises an aliphatic dibasic acid ester plasticizer.

In addition, the Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of the second fluororubber is 50 to 50 to that of the first fluororubber (ML(1+10) at 121°C, ASTM D1646). It provides a fluororesin composition, characterized in that 70 large.

Here, the first fluorine rubber has a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of 40 to 80, and the second fluorine rubber has a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) is characterized in that 100 to 150, it provides a fluororesin composition.

Meanwhile, at least one stone wire conductor; And an insulating layer formed from the fluororesin composition according to claim 1 or 2 and surrounding the conductor.

The fluororesin composition according to the present invention improves not only heat resistance and chemical resistance, but also flexibility and processability by adopting a fluoropolymer having a controlled melting point as a base resin, and at the same time, by adding two types of fluororubbers having different viscosities, flexibility and It shows an excellent effect of improving all of the abrasion resistance in conflict.

In addition, the fluororesin composition according to the present invention exhibits excellent effects that satisfy all of the cold resistance, flame retardancy, and processability required for use as an insulating layer for high heat-resistant electric wires for automobiles by the addition of processing aids and plasticizers.

1 is a schematic cross-sectional view of a T6 class high heat-resistant wire.

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

The fluororesin composition according to the present invention may include, as a base resin, a fluoropolymer and a resin in which two types of fluororubbers having different molecular weights are blended.

The fluorine copolymer is not particularly limited as long as it has a melting point of 100 to 155°C. When the melting point of the fluoropolymer exceeds 155°C, the processability of the fluororesin composition may be greatly deteriorated.

The fluorine copolymer is, for example, vinylidenefluoride (VDF) and hexafluoropropylene (HFP), tetrafluoroethylene (TFE), chlorotetrafluoroethylene (CTFE), and purple. It may include a copolymer with one or more monomers selected from the group consisting of perfluoromethylvinylether (PMVE), and the like, and preferably, a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP). May include coalescence.

The fluorine copolymer not only has excellent heat resistance and chemical resistance, but also has high electrical insulation properties. The fluorine copolymer may include a block or random copolymer, and flexibility may be greatly improved compared to the fluorine homopolymer. The flexibility of the fluororesin composition containing the fluoropolymer may be evaluated as having a 5% secant modulus of the specimen prepared therefrom of 15 kgf/mm 2 or less.

The first fluorine rubber, which is one of the two types of fluorine rubber contained in the base resin, has a number average molecular weight (Mn) of 90,000 to 120,000 and a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of 40 to 80. As phosphorus fluorine rubber, binary (VDF+HFP) fluorine rubber of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), or vinylidene fluoride (VDF), hexafluoropropylene (HFP) and tetrafluoroethylene (TFE) or vinylidene fluoride (VDF), tetrafluoroethylene (TFE), and ternary (VDF+HFP+TFE) fluorine rubber of perfluoromethylvinyl ether (PMVE). The first fluororubber may further improve flexibility, cold resistance, and processability of the fluororesin composition.

The second fluorine rubber, which is another one of the two types of fluorine rubber, has a number average molecular weight (Mn) of 150,000 to 300,000 and a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of 100 to 150. As the first fluorine rubber, binary or ternary fluorine rubber may be included. The second fluororubber may improve the wear resistance of the fluororesin composition.

Based on 100 parts by weight of the base resin, the content of the fluoropolymer is 50 to 70 parts by weight, the content of the first fluororubber is 25 to 45 parts by weight, and the content of the second fluororubber is 3 to 10 parts by weight. I can.

When the content of the fluoropolymer is less than 50 parts by weight, the heat resistance and chemical resistance of the fluororesin composition may be insufficient, whereas when the content of the fluororesin composition is more than 70 parts by weight, the flexibility of the fluororesin composition may be greatly reduced.

In addition, if the content of the first fluororubber is less than 25 parts by weight, the flexibility, cold resistance, processability, etc. of the fluororesin composition may be insufficient, whereas if it exceeds 45 parts by weight, the abrasion resistance of the fluororesin composition may be significantly reduced. have.

Further, when the content of the second fluororubber is less than 3 parts by weight, the abrasion resistance of the fluororesin composition may be insufficient, whereas when the content is more than 10 parts by weight, the flexibility of the fluororesin composition may be significantly reduced.

Here, the fluorine content (F contents) of the first fluororubber and the second fluororubber may be preferably 60 to 70% by weight, more preferably 66% by weight, and the number average molecular weight of the second fluororubber (Mn) is 50,000 to 150,000 larger than the number average molecular weight (Mn) of the first fluororubber, and accordingly, the Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of the second fluororubber is It is preferably 50 to 70 higher than the Mooney viscosity of fluororubber.

The fluororesin composition according to the present invention may improve not only heat resistance and chemical resistance, but also flexibility and processability by including a fluorine copolymer having a controlled melting point as a base resin in a specific mixing ratio as described above, and also have different molecular weights. Accordingly, by including two types of fluororubbers having different viscosities at a specific mixing ratio, both flexibility and abrasion resistance in conflict with this can be improved.

The fluororesin composition according to the present invention may further include additives such as processing aids, plasticizers, and crosslinking agents.

The processing aid serves to maintain the physical properties, especially the elongation rate after heating of the fluororesin composition, and since ordinary processing aids such as polyethylene wax can be destroyed upon heating, the elongation rate of the fluororesin composition is excellent in heat resistance even under heating conditions. It is preferable to include a fluorine-containing processing aid capable of holding, for example, a fluorinated olefin-based processing aid. The content of the processing aid may be 3 to 7 parts by weight based on 100 parts by weight of the base resin.

In addition, the plasticizer may be added to further improve the cold resistance and processability of the fluororesin composition, for example, phthalic acid ester, aliphatic dibasic acid ester, polyester, epoxy plasticizer, etc. may be used. , It may be added in an amount of 3 to 6 parts by weight based on 100 parts by weight of the base resin.

The crosslinking agent can improve the room temperature properties, especially tensile strength and heat resistance of the fluororesin composition through crosslinking of the fluororesin, for example, amine-based, silane-based, polyol-based, peroxide-based crosslinking agents, etc. can be used. , It may be added in an amount of 1 to 5 parts by weight based on 100 parts by weight of the base resin.

The present invention relates to a low-voltage electric wire including a plurality of stone conductors and an insulating layer formed of the fluororesin composition as an insulating layer surrounding the conductors.

[Example]

1. Manufacturing example

A fluororesin composition specimen and a wire specimen according to each of the Examples and Comparative Examples were prepared with the components and contents shown in Table 1 below. The fluororesin composition specimen was prepared by kneading at 155° C. for 30 minutes using a 3L kneader, and the wire specimen was prepared with an outer diameter of 1.72 mm using a 0.5 mm2 conductor through a wire extruder. The units of the content listed in Table 1 below are parts by weight.

2. Property evaluation

1) Room temperature properties (tensile strength, elongation and flexibility)

The tensile strength, elongation and flexibility of the fluororesin composition specimens of each of the Examples and Comparative Examples were measured according to the ARX-9 standard, the tensile strength should be 1.05 kgf/mm2 or more, the elongation rate should be 150% or more, and the flexibility is 5% secant. If the modulus was 15 kgf/mm 2 or less, it was evaluated as good (○), and if it exceeded 15 kgf/mm 2, it was evaluated as bad (x).

2) Physical properties after heating (tensile strength and elongation)

According to the ARX-9 standard, the fluororesin composition specimens of Examples and Comparative Examples were heated in a convection oven at 225°C for 240 hours, and then tensile strength and elongation were measured, and the residual tensile strength was 50% or more, and the residual elongation was 60. It must be at least %.

3) Cold resistance evaluation

In accordance with ARX-9 and ISO 6722 standards, the wire specimens of each of the Examples and Comparative Examples were wound around a mandrel 5 times the magnetic diameter in a -40°C convection oven, and a cold resistance test was conducted for about 4 hours with a 5 kg weight attached, There should be no cracks by rotating it twice at a speed of once per second, and there should be no abnormalities by performing the withstand voltage evaluation afterwards.

4) Wear resistance evaluation

In accordance with the ARX-9 standard, the wire specimens of each of the Examples and Comparative Examples should not be energized while passing a length of at least 457 mm while rubbing against sandpaper while pressing with a load of 450 g.

5) Pinch characteristics evaluation

According to the ARX-9 standard, when pressure is applied to the insulating surface of each of the wire specimens in Examples and Comparative Examples, the pressure to be energized must be at least 2.7 kgf/㎟.

6) Evaluation of extrudability

Extrusion properties were evaluated very good (◎), good (○), and bad (×) during extrusion for the production of wire specimens according to the examples and comparative examples, respectively.

Example Comparative example One 2 One 2 3 4 5 6 7 8 9 10 11 12



Furtherance Suzy 1 50 70 45 72 58 50 50 50 50 50 50 50 50 Suzy2 50 Rubber 1 40 27 45 25 40 38 40 40 40 40 40 40 40 40 Rubber 2 10 3 10 3 2 12 10 10 10 10 10 10 Rubber 3 10 Rubber 4 10 Processing aid 1 6 6 6 6 6 6 6 6 6 6 6 6 6 Processing aid 2 6 Plasticizer 5 5 5 5 5 5 5 5 5 5 0 8 5 5 Crosslinking agent 2.5 3 2.5 3 3 2.5 2.5 2.5 2.5 2.5 2.5 2.5 0 10 Item spec. Properties Room temperature
The tensile strength 1.05
kgf/㎟ One.
50 One.
72 One.
48 One.
79 One.
57 One.
47 One.
69 One.
47 One.
68 One.
49 One.
84 One.
43 One.
37 One.
69 Room temperature
Elongation 150% 348 271 371 265 389 377 327 358 366 367 373 361 462 261 Tensile strength residual 50% 95 93 94 94 92 95 95 93 95 127 102 - - 108 Elongation
Balance 60% 92 94 98 97 93 95 93 97 98 14 98 - - 91 flexibility ○ ○ ○ ○ × ○ ○ × ○ ○ ○ ○ ○ ○ ○ Cold resistance ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ × ○ ○ × Wear resistance 457mm 520 677 487 721 421 537 647 409 566 498 739 391 547 549 Pinch characteristics 2.7kgf/㎟ 3.4 5.1 2.3 5.7 2.5 3.6 4.9 2.3 3.4 3.2 6.3 2.2 3.8 4.1 Extrudability ◎○ ◎ ◎ ○ ◎ ◎ × ◎ ○ × ◎ ○ ◎ ◎ ◎

Resin 1: Block co-polymerization PVDF resin with a melting point of 140~145℃ (manufacturer: Arkema, product name: Kynarflex 2800)

Resin 2: Monopolymerized PVDF resin with a melting point of 160℃ (manufacturer: Arkema, product name: Kynarflex 2850)

Rubber 1: Fluorine rubber (molecular weight: 100,000, Mooney viscosity (ML(1+10) at 121℃, ASTM D1646): 62, fluorine content: 66% by weight)

Rubber 2: Fluorine rubber (molecular weight: 200,000, Mooney viscosity (ML(1+10) at 121℃, ASTM D1646): 124, fluorine content: 66% by weight)

Rubber 3: Fluorine rubber (molecular weight: 130,000, Mooney viscosity (ML(1+10) at 121℃, ASTM D1646): 97, fluorine content: 66% by weight)

Rubber 4: Fluorine rubber (molecular weight: 350,000, Mooney viscosity (ML(1+10) at 121℃, ASTM D1646): 150, fluorine content: 66% by weight)

Processing aid 1: Processing aid for fluorine rubber (Manufacturer: Solvay, Product name: Tecnoflon FPA-1)

Processing aid 2: General processing aid (PE Wax)

Plasticizer: bis(2-ethylhexyl)sebacate (manufacturer: LG Chem, product name: DOS)

Crosslinking agent: Trimethylolpropane trimethacrylate (TMPTMA) (manufacturer: Sartomer, product name: SR-350)

As shown in Table 1, the electric wire including the fluororesin composition of Examples 1 and 2 and the insulating layer formed therefrom according to the present invention maintains physical properties even after heating, so that it has excellent heat resistance, and in particular, flexibility and Abrasion resistance, other cold resistance, pinch characteristics, and extrudability were all confirmed to satisfy the standards of ARX-9 and ISO 6722.

On the other hand, the wire specimen of Comparative Example 1 contained an insufficient amount of a fluorine copolymer in the fluororesin composition forming the insulating layer thereof, so that the pinch characteristics were poor, and the fluororesin composition of Comparative Example 2 contained an excessive amount of the fluoropolymer. Therefore, it was confirmed that the flexibility was greatly reduced.

In addition, the fluororesin composition of Comparative Example 3 contained an insufficient amount of the second fluororubber to reduce abrasion resistance and pinch characteristics, and the fluororesin composition of Comparative Example 4 was added in excess of the second fluororubber, resulting in decreased extrudability. .

In addition, the fluororesin composition of Comparative Example 5 used a resin having a high melting point, and the flexibility was decreased.

On the other hand, in the wire specimen of Comparative Example 6, the molecular weight of the fluorine rubber contained in the fluororesin composition forming the insulating layer thereof was insufficient to be 150,000 or less, so that abrasion resistance and pinch characteristics were deteriorated, and the wire specimen of Comparative Example 7 had an insulating layer thereof. The molecular weight of the fluororubber contained in the fluororesin composition to be formed was excessive to 300,000 or more, and the extrudability was deteriorated.

In addition, it was confirmed that the fluororesin composition of Comparative Example 8 significantly decreased the elongation residual rate after heating due to the disappearance of the processing aid under heating conditions by adding a general processing aid, not a processing aid for fluorine rubber. The composition was confirmed that the cold resistance was significantly lowered by not adding a plasticizer, and in the wire specimen of Comparative Example 10, it was confirmed that the fluororesin composition forming the insulating layer thereof contained an excessive amount of the plasticizer, so that both abrasion resistance and pinch characteristics were reduced.

In addition, since the fluororesin composition of Comparative Example 11 did not contain a crosslinking agent, the heat resistance was greatly deteriorated, and it melted when the oven was put for a heating test, so that the residual tensile strength and the elongation residual after heating could not be evaluated.The fluororesin composition of Comparative Example 12 It was confirmed that the cold resistance was significantly reduced by including an excessive amount of the crosslinking agent.

Although the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art may variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You can do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be seen that all are included in the technical scope of the present invention.

10: conductor 20: insulating layer

Claims (11)

A number average molecular weight of 50 to 70 parts by weight of a fluorine copolymer having a melting point of 100 to 155°C as a base resin, 25 to 45 parts by weight of the first fluororubber, and 50,000 to 150,000 larger than the number average molecular weight (Mn) of the first fluororubber Including 3 to 10 parts by weight of a second fluororubber having (Mn),
The first fluorine rubber has a number average molecular weight (Mn) of 90,000 to 120,000, the second fluorine rubber has a number average molecular weight (Mn) of 150,000 to 300,000,
5% secant modulus (secant modulus), characterized in that 15 kgf / mm 2 or less, fluororesin composition. The method of claim 1,
The fluoropolymer is characterized in that it comprises a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), a fluororesin composition. delete The method of claim 1,
The first fluororubber and the second fluororubber are binary (VDF+HFP) fluorine rubbers of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), vinylidene fluoride (VDF), and hexafluoropropylene, respectively. (HFP) and tetrafluoroethylene (TFE) ternary (VDF+HFP+TFE) fluororubber, or vinylidene fluoride (VDF), tetrafluoroethylene (TFE) and perfluoromethylvinyl ether (PMVE) A fluorine resin composition comprising a ternary (VDF + TFE + PMVE) fluorine rubber. The method of claim 4,
The fluorine resin composition, characterized in that the fluorine content (F contents) of the first fluororubber and the second fluororubber is 60 to 70% by weight. delete The method according to claim 1 or 2,
The fluorine-containing processing aid comprises a fluorinated olefin-based processing aid. The method according to claim 1 or 2,
The plasticizer, characterized in that it comprises an aliphatic dibasic acid ester plasticizer, fluororesin composition. The method according to claim 1 or 2,
The Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of the second fluororubber is 50 to 70 greater than the Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of the first fluororubber Characterized in that, fluororesin composition. The method of claim 9,
The first fluororubber has a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) of 40 to 80, and the second fluororubber has a Mooney viscosity (ML(1+10) at 121°C, ASTM D1646) A fluororesin composition, characterized in that from 100 to 150. One or more stone conductors; And
A low-voltage electric wire comprising an insulating layer formed from the fluororesin composition according to claim 1 or 2 and surrounding the conductor.

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