KR100479738B1 - Polymer composition for insulating material and Locomotive wire using it - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composition for insulating materials of electric wires, and more particularly to a polymer composition used for electric wires for railway vehicles, which require relatively excellent mechanical and electrical properties compared to general electric wires.

The polymer composition of the present invention

(1) 60 to 100 parts by weight of (a) ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28%; And (b) 100 parts by weight of the base resin mixed with 5 to 30 parts by weight of ethylene vinyl acetate resin introduced with maleic anhydride;

(2) 30 to 90 parts by weight of an inorganic flame retardant;

(3) 10 to 30 parts by weight of the inorganic flame retardant;

(4) 20 to 50 parts by weight of halogen flame retardant;

(5) 1 to 4 parts by weight of crosslinking agent; And

(6) 3 to 6 parts by weight of the crosslinking aid.

Description

Polymer composition for insulating material and Locomotive wire using it}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer composition for insulating materials of electric wires, and more particularly to a polymer composition used for electric wires for railway vehicles, which require relatively excellent mechanical and electrical properties compared to general electric wires.

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, it is very important to develop and maintain electrical properties such as insulation resistance over a certain level in order to secure safety for a large number of people and a large amount of cargo and equipment due to the nature of the use.

In particular, in addition to the basic physical properties such as excellent heat resistance, oil resistance, cold resistance, fire stability, etc., the electric wire for railway vehicles requires high characteristics such as wear resistance and compression resistance.

In order to satisfy the physical properties required for railway vehicle electric wires, the present inventors have previously applied for a polymer composition for insulating materials having heat resistance / oil resistance and excellent cold resistance at the same time in use environment and having low smoke-free property as Korean Patent Application No. 2001-68731. have.

The polymer composition is excellent in basic physical properties such as heat resistance, oil resistance, cold resistance, fire stability, etc., but is not satisfactory such as insulation resistance, abrasion resistance, compression resistance and color invariance after heating.

Therefore, there is a need for a vehicle wire material which is basically excellent in heat resistance and cold resistance in an environment of use, exhibits oil resistance, low smoke resistance, and flame resistance, and excellent insulation resistance, abrasion resistance, and color invariance after heating.

Conventional electric wire material for railway vehicles is insulated resistance, discoloration degree after heating for 168 hours at 170 ℃, 81.6g load, extended length after standing at 250 ℃ for 90 minutes, scraper applied for 1000g load per minute The criterion for the number of times of 55 reciprocating wear until energization could not be satisfied at the same time.

The present invention is to solve the problems of the prior art, the object of the present invention exhibits excellent tensile strength, elongation rate, low temperature, flame retardant properties at room temperature or even after heating or infiltration, as well as insulation resistance, abrasion resistance, resistance to heat after heating To provide a vehicle wire and a polymer composition used in the wire having excellent compressibility and excellent color invariance.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the appended claims.

In order to achieve the above object, the polymer composition of the present invention is a basic resin blended with an ethylene-vinyl acetate copolymer resin containing 28% vinyl acetate and an ethylene-vinyl acetate copolymer resin containing maleic anhydride. It includes a flame retardant for imparting flame retardant properties, crosslinking agents, crosslinking aids and other additives.

The base resin is a blend of 60 to 100 parts by weight of ethylene-vinyl acetate copolymer resin having 28% vinyl acetate content and 5 to 30 parts by weight of ethylene-vinyl acetate copolymer resin into which maleic anhydride is introduced.

In addition, the base resin is 60 to 100 parts by weight of ethylene-vinyl acetate copolymer resin containing 28% vinyl acetate, 5 to 20 parts by weight of low density polyethylene and 5 to 30 parts by weight of ethylene-vinyl acetate copolymer resin into which maleic anhydride is introduced. It can also be achieved by blending parts.

As the flame retardant, an inorganic flame retardant, a flame retardant aid, and a halogen flame retardant were used.

The inorganic flame retardant is used 30 to 90 parts by weight based on 100 parts by weight of the base resin. As the inorganic flame retardant, magnesium hydroxide or aluminum hydroxide surface-treated with vinylsilane, fatty acid, amino polysiloxane, or the like was used. As such, when the inorganic flame retardant is surface treated, the mechanical and flame retardant properties of the polymer composition are further improved.

The inorganic flame retardant aid is used 10 to 30 parts by weight based on 100 parts by weight of the basic resin. Antimony-based and zinc-based materials were used as inorganic flame-retardant aids added to further enhance the flame retardant properties of the polymer composition.

The halogen flame retardant is used 20 to 50 parts by weight based on 100 parts by weight of the base resin. In the case of the present invention, a bromine-based material was used as the halogen flame retardant.

The crosslinking agent is used 1 to 4 parts by weight based on 100 parts by weight of the base resin, a peroxide-based crosslinking agent is preferred.

The crosslinking aid is used 3 to 6 parts by weight based on 100 parts by weight of the base resin, the cyanurate-based crosslinking aid is preferred.

The other additives are added to improve the durability and processability of the polymer composition, consisting of antioxidants, lubricants, processing aids.

The antioxidant is preferably used in an amount of 2 to 6 parts by weight based on 100 parts by weight of the base resin, and in particular, a dialkyl ester-based, thioester-based, phenol-based material or a mixture of these materials is used.

The lubricant was used 2 to 5 parts by weight based on 100 parts by weight of the base resin, and the processing aid was used 0.5 to 4 parts by weight based on 100 parts by weight of the base resin.

In addition, the vehicle wire of the present invention, as shown in Figure 1, the conductor bundle; An insulator surrounding the conductor bundle; And a separation film positioned between the conductor bundle and the insulator. At this time, the insulator portion is made of the polymer composition of the present invention described above.

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 composed of the polymer composition according to the present invention was prepared by molding in a press at a temperature of 170 ° C. for 10 minutes. In addition, a cable (wire material specimen) having a structure as shown in FIG. 1 was prepared using the polymer composition. At this time, the thickness of the insulating material of the cable was 0.5 to 5mm.

The prepared specimens were subjected to room temperature characteristics, insulation resistance, insulation resistance after heating, discoloration characteristics, abrasion resistance and hot set tests as follows.

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 cable (wire material specimen) having a structure as shown in FIG. 1 was prepared using the polymer composition. At this time, the thickness of the insulating material of the cable was 0.5 to 5mm.

Thus prepared specimens were subjected to room temperature characteristics, insulation resistance, insulation resistance after heating, discoloration characteristics, abrasion resistance and hot set tests as follows.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Resin a 80 80 80 80 80 90 90 Resin b 10 - - 20 10 10 10 Resin c 10 20 20 - 10 - - Inorganic flame retardant a - - - 50 40 - - Inorganic flame retardant b 40 70 40 - - 60 20 halogen Flame retardant 45 35 35 45 45 45 45 weapon Flame Retardant 25 20 20 25 25 25 45 Lubricant 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Processing aid 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Antioxidant 4.5 4.5 4.5 4.5 4.5 4.5 4.5 Crosslinking agent 3 3 3 6 7 6 7 Crosslinking aid 5 5 4 2 3 2 5

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

Resin b: low density polyethylene

Resin c: Ethylene-vinyl acetate copolymer resin incorporating maleic anhydride

Inorganic flame retardant a: No surface treatment

Inorganic flame retardant b: Surface treated with vinyl silane

Test Example

The following tests were performed on the polymer material specimens of Examples 1 to 3 and Comparative Examples 1 to 4 to evaluate the properties. The evaluation results are shown in Table 2 below.

(1) Room temperature characteristic

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 elongation should be more than 200%.

(2) insulation resistance

When the insulation resistance is measured using the HP 4339B and HP 16008B insulation resistance measuring devices, the value should be 10 ¹⁴ Ω · cm or more.

(3) Insulation resistance after heating

After leaving the specimen at a temperature of 170 ° C. for 168 hours, the insulation resistance should be greater than 10 ¹⁴ Ω · cm.

(4) discoloration characteristics

After leaving the specimen at a temperature of 170 ° C. for 168 hours, no discoloration should appear in comparison with the original color.

(5) wear resistance

Abrasion resistance was tested on 8 AWG wire samples which were stripped and fixed at 2.5 cm (1 inch) at both ends from a length of 61 cm (24 inches) using 158L238G1 from Wellman Thermal System or Repeated abrasion tester from General Electric.

Made of RC 61-65 standard SAE W2 tool steel, the reciprocator was reciprocated 55 times per minute for 1 cm length of wire sample with a load of 1000 g on a scraper with an angle of 90 ° and a radius of 0.13 mm (0.005 inch). The abrasion resistance test shall be carried out until energization is made, and insulation shall be maintained for not less than 2000 times when all four quadrants of the wire have been tested with successive 90 ° clockwise rotation.

(6) hot set

81.6 g of the specimen was loaded, left at 250 ° C. for 90 minutes, and the length was measured. After measuring for 5 minutes at room temperature, no change of more than 75% and 15% of the original length occurred, respectively. do.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 The tensile strength (Kg _f / Mm2) 1.72 1.42 1.71 1.75 1.81 1.61 1.76 Elongation (%) 296 334 316 261 178 271 245 Insulation resistance ( 10 ¹⁴ Ωcm) 11.24 15.75 7.44 0.75 0.49 0.61 2.04 Insulation resistance after heating ( 10 ¹⁴ Ωcm) 6.36 7.87 4.87 0.31 0.14 0.39 1.46 Wear resistance pass pass pass pass pass leaving out pass Hot set pass pass pass leaving out pass pass pass Discoloration degree pass pass pass leaving out leaving out leaving out leaving out

Evaluation result of characteristic

Examples 1 to 3

In the case of Examples 1 to 3, after standing at 170 ° C. for 168 hours, when the insulation resistance was measured using the HP 4339B and HP16008B insulation resistance measuring devices, the resistance was 10 ¹⁴ ? It was confirmed that the degree of is sufficiently maintained.

In addition, when the color of the sample of the above embodiment was left under the same conditions and irradiated, no color change was detected.

Using the Wellman Thermal System's 158L238G1 wear resistance measuring device, a reciprocating machine made of RC 61-65 standard SAE W2 tool steel with a radius of 0.13 mm (0.005 inch) scraper with a load of 1000g and 55 round trips per minute for 8 AWG wire sample Insulation resistance was maintained for more than 2000 times when the abrasion resistance test was conducted until energized.

In addition, the hot-set test for measuring the length after leaving the sample loaded with 81.6g for 90 minutes at 250 ° C. showed no change of more than 1 mm and showed sufficient results in tensile strength and elongation, which are basic properties. .

Comparative Example 1

A blend of an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28% and a low density polyethylene resin was used as the base resin, and a flame retardant was added thereto, and the ratio of the peroxide-based crosslinking agent and the crosslinking aid was 6: 2.

However, due to the problem of the low density polyethylene content and the ratio of the crosslinking agent to the crosslinking agent, defects occurred in the insulation resistance, the insulation resistance after heating and the discoloration test results.

Comparative Example 2

A blend of an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28%, a low density polyethylene resin and maleic anhydride, and an ethylene-vinyl acetate copolymer resin containing maleic anhydride was used as the base resin, and the ratio of the crosslinking agent and the crosslinking aid was 7: 3. It was made.

In Comparative Example 2, as can be seen in Table 2, a defect occurred in the insulation resistance and discoloration test results after heating.

Comparative Example 3

A blend of an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28% and a low density polyethylene resin was used as the base resin, and the ratio of the crosslinking agent and the crosslinking aid was 6: 2. In particular, 60 parts by weight of an inorganic flame retardant whose surface was treated with vinyl silane was used.

In Comparative Example 3, as can be seen from Table 2, defects occurred in all of the insulation resistance, insulation resistance after heating, abrasion resistance, and discoloration test results.

Comparative Example 4

A blend of an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28% and a low density polyethylene resin was used as the base resin, and the ratio of the crosslinking agent and the crosslinking aid was 7: 5. In particular, 20 parts by weight of an inorganic flame retardant whose surface was treated with vinyl silane was used.

In Comparative Example 4, as can be seen from Table 2, insulation resistance and wear resistance were satisfactory, but problems occurred in discoloration.

That is, as can be seen from the characteristics evaluation results of Comparative Examples 1 to 4, by blending the base resin appropriately and treating the surface of the inorganic flame retardant with vinyl silane, characteristics such as wear resistance and insulation resistance after heating are improved. However, the problem of discoloration after heating cannot be solved.

As mentioned above, although this invention was demonstrated by the limited embodiment, this invention is not limited by this and it will be described below by the person of ordinary skill in the art, and the following. Of course, various modifications and variations are possible within the scope of the claims.

The polymer composition for insulating materials according to the present invention is not only excellent in basic physical properties such as flame retardancy, low smoke resistance, heat resistance, oil resistance, cold resistance, and excellent mechanical properties required for electric wires for railroad cars, but also insulation resistance and color change in the use environment. The property is very stable against high temperature heat history.

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

Claims (16)

delete delete (1) 60 to 100 parts by weight of an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28%; 5 to 30 parts by weight of ethylene vinyl acetate resin introduced with maleic anhydride; And 100 parts by weight of the base resin mixed with 5 to 20 parts by weight of low density polyethylene; (2) 30 to 90 parts by weight of an inorganic flame retardant; (3) 10 to 30 parts by weight of the inorganic flame retardant; (4) 20 to 50 parts by weight of halogen flame retardant; (5) 1 to 4 parts by weight of crosslinking agent; And (6) 3 to 6 parts by weight of crosslinking aid; The polymer composition for insulating materials, characterized in that the addition ratio of the crosslinking agent and the crosslinking aid is 3: 4 to 3: 5. The method of claim 3, wherein 2 to 6 parts by weight of the antioxidant, and 2 to 5 parts by weight of the lubricant further comprises a polymer composition. The method of claim 4, wherein 1 to 4 parts by weight of the processing aid further comprises a polymer composition. The method of claim 5, wherein The inorganic flame retardant is a polymer composition, characterized in that the magnesium hydroxide or aluminum hydroxide surface-treated with vinylsilane, fatty acid, or amino polysiloxane. The method of claim 5, wherein Polymer composition, characterized in that the halogen flame retardant is a bromine-based material. The method of claim 5, wherein The polymer composition, characterized in that the flame retardant aid is an antimony or zinc-based material. The method of claim 5, wherein The antioxidant composition is selected from dialkyl ester-based, thioester-based, phenol-based materials and mixtures thereof. The method of claim 5, wherein The crosslinking agent is a peroxide-based material, the crosslinking aid is a polymer composition, characterized in that the cyanurate-based material. Conductor bundle; An insulator surrounding the conductor bundle; And a separation film positioned between the conductor bundle and the insulator, The insulator (1) 60 to 100 parts by weight of (a) ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 28%; And (b) 100 parts by weight of a base resin mixed with 5 to 30 parts by weight of ethylene vinyl acetate resin containing maleic anhydride; (2) 30 to 90 parts by weight of an inorganic flame retardant; (3) 10 to 30 parts by weight of the inorganic flame retardant; (4) 20 to 50 parts by weight of halogen flame retardant; (5) 1 to 4 parts by weight of crosslinking agent; And (6) an electric wire for a vehicle, comprising a polymer composition comprising 3 to 6 parts by weight of the crosslinking aid. The method of claim 11, An electric wire, characterized in that 5 to 20 parts by weight of the low density polyethylene is further mixed with the base resin. The method according to claim 11 or 12, The electric wire, characterized in that the addition ratio of the crosslinking agent and the crosslinking aid is 3: 4 to 3: 5. The method of claim 13, wherein the polymer composition is 2 to 6 parts by weight of antioxidant, and 2 to 5 parts by weight of lubricant. The method of claim 14, wherein the polymer composition The wire further comprises 1 to 4 parts by weight of the processing aid. The method of claim 15, And the inorganic flame retardant is magnesium hydroxide or aluminum hydroxide surface-treated with vinylsilane, fatty acid, or amino polysiloxane.