KR20030037522A - Polymer composition with low smoke and heat resistance for insulating material and Locomotive wire using it - Google Patents

Abstract

PURPOSE: Provided are a high molecular composition for an insulating material having heat resistance/oil resistance and improved cold resistance, as well as low smoking property, and an electric wire for vehicles using the same. CONSTITUTION: The composition comprises 100 parts by weight of mixed basic resin obtained by mixing (a) ethylene-vinyl acetate copolymer resin having 24-32% of vinyl acetate, (b) low density polyethylene resin, and (c) ethylene vinyl acetate resin(c) comprising maleic anhydride, or by mixing (a) with (b) or (c); 10-100 parts by weight of inorganic flame-retardants; 1-50 parts by weight of inorganic flame-retardant aids; 20-100 parts by weight of flame-retardant of halogen; 0.5-10 parts by weight of activator; 1-10 parts by weight of antioxidant; 1-10 parts by weight of crosslinking agent; and 1-10 parts by weight of crosslinking aid.

Description

Polymer composition with low smoke and heat resistance for insulating material and Locomotive wire using it}

The present invention relates to a polymer composition for insulating materials having heat resistance / oil resistance and excellent cold resistance at the same time in a use environment and having a low smoke property and a vehicle electric wire using the same.

Since railroad car wires are used in more severe conditions than ordinary wires, they must have excellent characteristics in heat resistance and oil resistance, and especially they must be able to maintain their characteristics for a long time under various climatic conditions such as high temperature and low temperature as well as rapid temperature change. In addition, in order to ensure safety and to minimize the loss of life, cargo and equipment when a fire occurs in the vehicle, it is necessary to have fire safety such as flame retardancy as well as low smoke. Recently, due to the expansion of the construction of high-speed railways and the increase in the range of use, there is a growing demand for the use and role of the wires for vehicles, and thus, more excellent characteristics are required.

Conventional products use crosslinking in the manufacturing process to improve heat resistance, and polyolefin-based resins are most suitable for applying this technique. However, the polyolefin resin was not excellent in heat resistance and fell short of the ICEA S 19-81 specification (the tensile strength and elongation after initial 168 hours at 170 ° C. should be at least 50%).

In addition, there have been attempts to blend and use EVA or EEA to secure oil resistance, but in this case, the crosslinking degree is not high, resulting in poor heat resistance, and the oil resistance is also ICEA S 66-524 standard (ASTM No. 2 at a temperature of 150 ° C). Tensile strength and elongation after soaking in the test oil for 6 days should not reach the initial 50%).

Since the regulation of halogen-based materials is still only partially introduced into railway vehicle wires, halogen-containing flame retardants including bromine may be introduced to improve flame retardancy. However, it is known that cold resistance, which is an essential characteristic, deteriorates rapidly when a part of it is replaced by an inorganic filler to satisfy low smokeability.

The present invention relates to a composition comprising a base resin and all additives used as vehicle wires and insulating materials satisfying all the above specifications and expressing excellent mechanical properties.

For materials developed by existing inventions and technologies, tensile strength and elongation after soaking for 6 days in ASTM No. 2 test oil at room temperature and 150 ° C as specified in ICEA S 66-524, and as specified in ICEA S 19-81 Tensile strength and elongation after heating at 170 ° C for 168 hours, cold winding and low temperature impact after 1 hour at -55 ° C as defined in ICEA S 61-402, and 1 minute 30 seconds and 4 as specified in NFPA 258. The criterion for smoke density after minutes was not satisfied at the same time.

The present invention is to solve the problems of the prior art, satisfies all the standards for tensile strength and elongation after room temperature, after heating, after immersion, and satisfies the winding and impact characteristics and smoke density and VFT flame retardant characteristics at low temperatures. In addition, it is an object of the present invention to provide a vehicle wire that does not change the surface at all after a sudden temperature change for 42 days at 90 ℃ and -18 ℃ for 42 hours.

Figure 1 shows the structure of the vehicle wire of the present invention.

The present invention relates to a vehicle wire and a flame retardant polymer composition for insulating materials used therefor that exhibits excellent heat resistance and oil resistance at the same time in use environment, and has low smoke resistance. In order to configure the electric wire with materials such as base resin and additives.

Flame-retardant insulating material of the present invention, polyethylene, polar ethylene vinyl acetate, ethylene vinyl acetate as a base resin, the inorganic flame retardant of inorganic metal compounds, inorganic flame retardant aids and halogen flame retardant introduced flame retardant properties, antioxidants and lubricants And a crosslinking agent and a crosslinking aid suitable for the required properties.

The flame retardant polymer composition for insulating materials of the present invention,

Ethylene-vinyl acetate copolymer (a) having a vinyl acetate content of 24 to 32% is mixed with ethylene vinyl acetate resin (c) having a low density polyethylene resin (b) and maleic anhydride introduced therein, or (a) 100 parts by weight of the mixed base resin mixed with b) or (c) alone; 10 to 100 parts by weight of the inorganic flame retardant; 1 to 50 parts by weight of the inorganic flame retardant aid; 20 to 100 parts by weight of halogen flame retardant; 0.5 to 10 parts by weight of lubricant; 1 to 10 parts by weight of antioxidant; 1 to 10 parts by weight of a crosslinking agent; And 1 to 10 parts by weight of the crosslinking aid.

The base resin is preferably, 60 to 100 parts by weight of ethylene-vinyl acetate copolymer resin (a); 5 to 40 parts by weight of the low density polyethylene resin (b); 5 to 40 parts by weight of ethylene vinyl acetate resin (c) introduced with maleic anhydride. In addition, the base resin and 60 to 100 parts by weight of ethylene-vinyl acetate copolymer resin (a); 5 to 40 parts by weight of (b) or (c).

The ethylene-vinyl acetate copolymer resin is preferably 28% vinyl acetate.

In the present invention, inorganic flame retardants, halogen flame retardants and flame retardant aids are used to impart flame retardancy.

As the inorganic flame retardant, a known general inorganic flame retardant may be used. Preferably, magnesium hydroxide or aluminum hydroxide is used in an amount of 10 parts by weight to 100 parts by weight based on 100 parts by weight of the base resin. More preferably, the magnesium hydroxide or aluminum hydroxide uses a surface-treated product of vinylsilane, fatty acid, amino polysiloxane, or the like to satisfy the mechanical and flame retardant properties of the insulating material.

As the halogen flame retardant, preferably 20 parts by weight to 80 parts by weight of bromine system is used.

As a flame retardant aid, 10 to 50 parts by weight of the existing antimony-based or zinc-based products are used to enhance the flame retardant properties.

Conventional antioxidants are used to improve durability, and preferably 1 to 10 parts by weight of dialkyl ester, thioester or phenolic antioxidants are used. In addition, small amounts (0.5 to 10 parts by weight) of conventional lubricants are used to improve processability.

The vehicle wire of the present invention is generally a conductor bundle; An insulator surrounding the conductor bundle; And a separation film positioned between the conductor bundle and the insulator, wherein the insulator portion is made of the polymer composition of the present invention described above. The wire for a vehicle of the present invention is usually configured as shown in FIG.

Automotive wires of the present invention, as confirmed by the following examples, the room temperature characteristics of ICEA S 66-524, after-heating characteristics of ICEA S 19-81, oil resistance characteristics of ICEA S 66-524, IEA S 61-402 It is a vehicle wire that has heat resistance, oil resistance, cold resistance, low smoke resistance and excellent mechanical properties satisfying both the low temperature property and the smoke property of NFPA 258.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the scope of the present invention is not limited by the following examples, and those skilled in the art to which the present invention pertains should be within the equivalent scope of the technical concept of the present invention and the claims to be described below. Of course, various modifications and variations are possible.

Examples 1 to 3

After kneading in an open roll with a composition as shown in Table 1, an insulating material specimen including the flame retardant polymer composition of the present invention was prepared by molding for 10 minutes in a press at a temperature of 170 ° C. In addition, the vehicle wire of the present invention was made with the structure as shown in Figure 1 using the prepared insulating material. The prepared specimens were evaluated for properties in the following test examples, and the prepared wires were subjected to VFT flame retardant test and smoke density test according to NFPA 258 standard. In the flame-retardant material of the produced electric wire, the thickness was 0.5-5 mm.

Comparative Examples 1 to 4

After kneading in an open roll with a composition as shown in Table 1, a polymer material specimen was prepared by molding in a press at 170 ° C. for 10 minutes. In addition, a vehicle wire having a structure as shown in FIG. 1 was made using the prepared insulating material. The prepared specimens were evaluated for properties in the following test examples, and the prepared wires were subjected to VFT flame retardant test and smoke density test according to NFPA 258 standard. In the flame-retardant material of the produced electric wire, the thickness was 0.5-5 mm. The characteristics of each comparative example are as follows.

(1) Comparative Example 1

In order to secure the heat resistance and mechanical properties, a blend of ethylene-vinyl acetate copolymer resin containing 18% vinyl acetate and high density polyethylene resin was used as the base resin, and the fire safety was given by the inorganic flame retardant and the halogen flame retardant.

(2) Comparative Example 2

Ethylene-vinyl acetate copolymer resin containing 18% vinyl acetate was used as the base resin by increasing the specific gravity of polyolefin resin suitable for crosslinking to enhance heat resistance and low temperature characteristics, and impart fire stability with inorganic flame retardant and halogen flame retardant. It was.

(3) Comparative Example 3

In order to improve oil resistance and low temperature characteristics, ethylene-vinyl acetate copolymer resin containing 28% vinyl acetate was used as a base resin, and a flame retardant was added to impart fire stability.

(4) Comparative Example 4

In order to enhance the heat resistance, cold resistance and oil resistance properties, a blend of ethylene-vinyl acetate copolymer resin containing 28% vinyl acetate, high density polyethylene resin and low density polyethylene was used as a base resin. Increasing the proportion of flame retardants.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Resin a - - - 80 100 - - Resin b 90 70 80 - - 100 80 Resin c - - - 20 - - 10 Resin d 10 20 - - - - 10 Resin e - 10 20 - - - - Inorganic flame retardants 40 25 55 40 45 55 35 Halogen flame retardant 45 55 40 55 50 40 70 Inorganic flame retardant 25 25 25 25 25 25 25 Lubricant 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Antioxidant 4.5 4.5 4.5 4.5 4.5 4.5 4.5 Crosslinking agent 6 6 6 6 6 6 6 Crosslinking aid 2 2 2 2 2 2 2

Resin a: Vinyl acetate 18% containing ethylene-vinyl acetate copolymer resin

Resin b: Vinyl acetate 28% containing ethylene-vinyl acetate copolymer resin

Resin c: high density polyethylene

Resin d: low density polyethylene

Resin e: Ethylene vinyl acetate containing maleic anhydride

Test Example

The following tests were conducted on the polymer materials and wires of Examples 1 to 3 and Comparative Examples 1 to 4 to evaluate the characteristics, and the VFT flame retardant test and the smoke density test according to the NFPA 258 standard were conducted on the manufactured wires. Was carried out. The test results are shown in Table 2 below.

Tensile strength (㎏ _f / Mm2) 1.71 1.63 1.89 2.10 1.81 1.38 1.91 Elongation (%) 316 336 271 205 280 367 266 Heat-resistant tensile strength 1.60 1.52 1.93 2.07 1.76 leaving out 1.83 Heat resistance 245 260 221 189 177 leaving out 212 Intrinsic tensile strength 1.24 1.07 1.33 1.43 leaving out 0.83 1.36 Oil resistance 206 215 189 151 leaving out 229 181 Low temperature shock after heating pass pass pass leaving out pass pass pass Repeated change pass pass pass leaving out pass pass pass Shrink after heating pass pass pass pass pass pass pass VFT flame retardant pass pass pass pass pass pass pass Smoke generation 1.5 minutes (N) * 0 0 0 0 0 0 13 Smoke generation 1.5 minutes (F) * 2 3 1.5 4 3.5 1.5 leaving out 4 minutes of smoke 0 0 0 0 0 0 172 4 minute smoke generation (F) 50 62 46 65 63 57 leaving out Oxygen index 40.5 41.3 40.8 41.6 39.4 40.6 43.5

* N: Nonflaming mode

F: Flaming mode

(1) Evaluation method of characteristic

The evaluation method of various characteristics is as follows.

1) Room temperature characteristics

When tensile strength and elongation are measured according to ICEA S 66-524 standard, the tensile strength should be more than 1.0kg _f / mm ² and the elongation should be more than 200%.

2) heat resistance

According to the ICEA S 19-81 standard, the tensile strength and the elongation rate should be not less than 50% of the initial value after 168 hours at 170 ℃.

3) Oil resistance

According to ICEA S 66-524 standard, after soaking at 150 ℃ for 6 days, the tensile strength and elongation rate should be more than 50% of the initial value respectively.

4) Low temperature shock after heating

A sample of 7.5 m in length was wound on a coil, left at a temperature of 170 ° C. for 7 days, and then divided into three parts. A sample having a length of 60 cm or less was wound six times on an axis of 2.5 cm in diameter according to the ICEA S-61-402 standard. When left at a temperature of ± 2 ℃ for more than one hour and released at a speed of 15 rpm, no cracks shall occur.

5) Shrink after heating

A 7.2 meter long sample shall be wound on a loose coil, left at 170 ° C for 7 days, cooled at room temperature for at least 1 hour, and not less than 3.18 mm measured when the change in length is measured.

6) Temperature change repetition

A sample of 2.4 m in length should be left at a temperature of 150 ° C for 4 hours, and then cracked after 250 repetitions of two hours at 90 ° C and -18 ° C.

7) VFT flame retardant

After burning for 15 seconds, the time until extinguishing should be measured and within 10 seconds.

8) Smoke generation

When tested for the presence of flame in accordance with NFPA 258, the smoke density at 1 minute 30 seconds and 4 minutes after combustion commencement shall be less than 100 and 200, respectively.

(2) Test result of Examples 1-3

1) ICEA S 61-402

As a result of the low temperature test according to the prescribed test method, it was confirmed that no crack was generated on the surface when bent or swelled after being left for 1 hour at a temperature of -55 ° C.

2) ICEA S 19-81

According to the prescribed test method, both tensile strength and elongation exceeded the initial 75% even after one week at 170 ℃, which is impossible to use with conventional prescription. In addition, the characteristics did not change even after being left at a high temperature of 170 ° C. for 1 week after being left at -55 ° C. for 1 hour. The test was conducted for 2 consecutive days at the rapid temperature change by applying the temperature of 2 hours alternately, and no problem such as crack occurred.

3) Test of oil resistance

Tensile strength and elongation were measured after soaking the sample in ASTM No. 2 test oil at 150 ° C for 6 days in accordance with ICEA S 66-524. In all cases, the initial characteristics were above 65%.

4) NFPA 258

When the test was conducted according to the regulations, the smoke density after 1 minute 30 seconds and 4 minutes in the absence of a flame was 0, and in the case of the flame, the results were 2 and 50, respectively.

5) VFT flame retardant test

After 15 seconds of combustion, it was confirmed that the fire extinguished immediately. It was confirmed that the oxygen index is 39 to 44 and has sufficient flame retardancy.

(3) Test result of comparative example

1) Comparative Example 1

The low content of vinyl acetate and high density polyethylene resin resulted in poor oil resistance test according to the ICEA S 66-524 standard and failed to meet the characteristics required for the cold test according to the ICEA S 61-402 standard.

2) Comparative Example 2

Due to the low content of vinyl acetate, the oil resistance test according to ICEA S 66-524 standard resulted in a defect.

3) Comparative Example 3

The oil resistance test according to the ICEA S 66-524 standard was good, but the heat resistance test according to the ICEA S 19-81 standard was defective due to the high content of vinyl acetate.

4) Comparative Example 4

The heat resistance test according to the ICEA S 19-81 standard, the oil test according to the ICEA S 66-524 standard, and the cold test according to the IEA S 61-402 standard were all satisfied. Due to the high content, the smoke performance exceeded the standard of smoke density test according to NFPA 258 standard.

As confirmed through the above examples and test examples, the flame retardant polymer composition for insulating materials of the present invention and the vehicle wire using the same have flame retardancy and low smoke resistance, and thus exhibit heat resistance, oil resistance, cold resistance, and excellent mechanical properties. It can be widely used in various environments in various environments regardless of climatic and ambient conditions because of stability to minimize loss of life and cargo in case of fire as well as harsh conditions such as temperature change.

Claims (10)

Ethylene-vinyl acetate copolymer (a) having a vinyl acetate content of 24 to 32% is mixed with ethylene vinyl acetate resin (c) having a low density polyethylene resin (b) and maleic anhydride introduced therein, or (a) b) or (c) 100 parts by weight of a mixed base resin alone; 10 to 100 parts by weight of the inorganic flame retardant; 1 to 50 parts by weight of the inorganic flame retardant aid; 20 to 100 parts by weight of halogen flame retardant; 0.5 to 10 parts by weight of lubricant; 1 to 10 parts by weight of antioxidant; 1 to 10 parts by weight of a crosslinking agent; And 1 to 10 parts by weight of the crosslinking aid. The method according to claim 1, The base resin is 60 to 100 parts by weight of ethylene-vinyl acetate copolymer resin (a); 5 to 40 parts by weight (b) of the low density polyethylene resin; 5 to 40 parts by weight of ethylene vinyl acetate resin (c) incorporating maleic anhydride. The method according to claim 1, The base resin is 60 to 100 parts by weight (a) of the ethylene-vinyl acetate copolymer resin; A composition comprising 5 to 40 parts by weight of a low density polyethylene resin (b) or 5 to 40 parts by weight of ethylene vinyl acetate resin (c) incorporating maleic anhydride. The method according to any one of claims 1 to 3, The ethylene-vinyl acetate copolymer resin is characterized in that the content of vinyl acetate is 28%. The method according to any one of claims 1 to 3, The inorganic flame retardant is a composition characterized in that the magnesium hydroxide or aluminum hydroxide surface-treated with vinylsilane, fatty acid, or amino polysiloxane. The method according to any one of claims 1 to 3, The halogen flame retardant is a composition characterized in that the bromine material. The method according to any one of claims 1 to 3, The flame retardant aid is a composition, characterized in that the antimony or zinc-based material. The method according to any one of claims 1 to 3, Wherein said antioxidant is selected from dialkyl esters, thioesters, phenolic materials and mixtures thereof. Conductor bundle; An insulator surrounding the conductor bundle; And a separation film positioned between the conductor bundle and the insulator, The insulator is a vehicle wire, characterized in that made of the polymer composition of claim 1. The method according to claim 9, The vehicle electric wires satisfy the room temperature characteristics of ICEA S 66-524, after heating of ICEA S 19-81, oil resistance characteristics of ICEA S 66-524, low temperature characteristics of ICEA S 61-402, and smoke characteristics of NFPA 258. wire.