CN1828783A - Non-halogen flame retardant wire and cable - Google Patents

Abstract

This invention provides non-halogen electric wire and cable those have both stiffness in flexure and mechanical strength. The electric wire 1 and cable 10 are covered with resin composition 3 and 6, and the resin composition 3 and 6 are composed by bending 100 relative weight shares mixed polymers and 30~50 weight shares metal hydroxides. Wherein the mixed polymers comprises 40~95 weight shares polyolefin and 60~5 weight shares ethylene interpolymers modified with maleic anhydride, and the modified alkene interpolymers are modified ethylene-propylene copolymers or modified ethylene-butylene copolymers.

Description

Non-halogen flame retardant wire and cable

technical field

The present invention relates to non-halogen flame-retardant wires and cables with small environmental loads, in particular to non-halogen flame-retardant wires and cables that take into account both flexibility and mechanical strength.

Background technique

In recent years, non-halogen flame-retardant wires and cables that do not use polyvinyl chloride and halogen-based flame retardants and have a small environmental load have rapidly become popular as environmentally friendly wires and cables. In these conventional non-halogen flame-retardant wires and cables, a resin composition in which a large amount of non-halogen flame retardant represented by magnesium hydroxide is mixed with polyolefin is generally used as the wire insulator or the cable sheath.

Furthermore, as one of recent trends, electric wires and cables using a resin composition made of a non-halogen material having excellent flexibility are required.

Here, prior art document information related to the invention of the present application is as follows.

[Patent Document 1] JP-A-2004-256621

[Patent Document 2] JP-A-2004-196877

Contents of the invention

In order to impart flexibility to electric wires and cables, a rubber-based soft material can be used in the resin composition matrix. However, since rubber-based soft materials have low mechanical strength, crosslinking is required to improve the mechanical strength, and it is difficult to apply non-crosslinked resin compositions.

In addition, in order to enable recycling of electric wires and cables, it is desirable to have a non-crosslinking resin composition.

Thus, it is difficult to balance the flexibility and mechanical strength of electric wires and cables using a non-crosslinked resin composition.

Therefore, an object of the present invention is to provide non-halogen flame-retardant electric wires and cables that balance flexibility and mechanical strength.

The present invention has been accomplished in order to achieve the above objects. The invention of claim 1 is a non-halogen flame-retardant wire and cable, which is a non-halogen flame-retardant wire and cable coated with a resin composition that is passed through a weight of 100 30-150 parts by weight of mixed polymers are mixed with 30 to 150 parts by weight of metal hydroxide, and the mixed polymers are a mixture of 40 to 95 parts by weight of polyolefin and 60 to 5 parts by weight of olefinic copolymer modified with maleic anhydride, The ethylenic copolymer modified with maleic anhydride is a maleic acid-modified ethylene-propylene copolymer or a maleic acid-modified ethylene-butene copolymer.

The invention of claim 2 is the non-halogen flame-retardant electric wire and cable according to claim 1, wherein the average particle size of the metal hydroxide is 0.5 μm or less, and the surface thereof is coated with methacrylate silane. processed.

The invention of claim 3 is the non-halogen flame-retardant electric wire and cable described in claim 1 or 2, which is produced by coating the resin composition in a non-crosslinked manner.

The invention of claim 4 is the non-halogen flame-retardant wire and cable according to any one of claims 1 to 3, wherein the 10% modulus of the non-halogen flame-retardant wire and cable is 3 MPa or less.

According to the present invention, it is possible to obtain a non-halogen flame-retardant electric wire and cable having both flexibility and mechanical strength.

Description of drawings

Fig. 1 is a cross-sectional view showing an example of a non-halogen flame-retardant electric wire and cable as a preferred embodiment of the present invention.

Symbol Description

1 non-halogen flame retardant wire

2 conductors

3 insulator (resin composition)

6 skin (resin composition)

10 non-halogen flame retardant cable

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described.

The non-halogen flame retardant resin composition related to this embodiment is prepared by mixing 30 to 150 parts by weight of metal hydroxide as a flame retardant with respect to 100 parts by weight of a mixed polymer, and the mixed polymer is 40 to 95 parts by weight of poly A mixture of olefin and 60 to 5 parts by weight of an olefinic copolymer modified with maleic anhydride (maleic acid modified olefinic copolymer).

As polyolefin, high, medium and low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, Linear low-density polyethylene (LLDPE), ultra-low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-butene copolymer, ethylene-methyl methacrylate copolymer, ethylene-octene copolymer, ethylene・Vinyl acetate copolymer (EVA), etc.

In order to impart excellent flexibility to electric wires and cables, ethylene-propylene copolymers, ethylene-propylene-diene terpolymers, ethylene-butene copolymers, and ethylene-octene copolymers are particularly preferable as polyolefins.

On the other hand, as the maleic acid-modified vinyl copolymer, a copolymer of ethylene-propylene copolymer or ethylene-butene copolymer modified with maleic anhydride as a soft polymer (maleic acid-modified ethylene propylene copolymer or maleic acid modified ethylene-butene copolymer).

The above-mentioned maleic acid-modified ethylene-propylene copolymer and maleic acid-modified ethylene-butene copolymer and conventionally used hard maleic acid-modified polymers (polyethylene, polypropylene, ethylene-ethyl acrylate copolymer) , maleic acid-modified type of ethylene-vinyl acetate copolymer), its advantage is that it is very excellent in flexibility.

The reason why the blending amount of the polyolefin is 40 to 95 parts by weight and the blending amount of the maleic acid-modified vinyl copolymer is 60 to 5 parts by weight is that if the blending amount of the maleic acid-modified vinyl copolymer is less than 5 parts by weight If the content is low, the bonding with the metal hydroxide is weak, and sufficient mechanical strength cannot be obtained for electric wires and cables. Another reason is that if the blending amount of the maleic acid-modified vinyl copolymer exceeds 60 parts by weight, the elongation of electric wires and cables will be greatly reduced.

As the metal hydroxide, magnesium hydroxide (Mg(OH) ₂ ), aluminum hydroxide (Al(OH) ₃ ), hydrotalcite, calcium aluminate hydrate, calcium hydroxide, barium hydroxide and the like are used. As magnesium hydroxide, synthetic magnesium hydroxide, natural magnesium hydroxide obtained by pulverizing natural ore, magnesium hydroxide forming a solid solution with other elements such as Ni, and the like are used.

The reason why the mixing amount of the metal hydroxide is 30 to 150 parts by weight relative to 100 parts by weight of the mixed polymer is that if the mixing amount is less than 30 parts by weight, the flame retardancy of the wire and cable is insufficient; if the mixing amount exceeds 150 parts by weight, the mechanical properties of wires and cables will be greatly reduced.

The metal hydroxide may have, for example, an average particle diameter of 0.5 μm or less, and its surface may be treated with methacrylic silane.

If the average particle size of the metal hydroxide exceeds 0.5 μm, the particle size becomes large, it is difficult to uniformly disperse the metal hydroxide in the resin composition, the mechanical strength of the wire and cable will decrease, and the heat deformation will also increase, so Preferably, it is equal to or less than 0.5 μm.

Moreover, compared with general silane coupling agents, such as vinyl silane (vinyl silane), methacryl silane (methacryl silane) has a large molecular weight, and has a linear long structure. It is considered that the elongated structure has a greater relaxation effect when subjected to stress than the short structure, and as a result, properties such as tensile strength and elongation are improved.

After the metal hydroxide is sprayed or impregnated with the methacrylic silane, the methacrylic silane can be adhered to the surface of the metal hydroxide by drying. The metal hydroxide surface-treated with methacrylic silane was mixed in the mixed polymer.

In addition, to the resin composition according to this embodiment, in addition to the above components, crosslinking aids, flame retardant aids, antioxidants, lubricants, stabilizers, fillers, colorants, silicones, etc. wait.

Next, an example of a non-halogen flame-retardant electric wire and cable according to this embodiment will be described.

As shown in FIG. 1 , the non-halogen flame-retardant wire (insulated wire) 1 according to the present embodiment is such that an insulator 3 made of the above-mentioned non-halogen flame-retardant resin composition is coated on a conductor 2 (periphery), and is non-crosslinked. made wires.

In addition, the non-halogen flame-retardant cable 10 according to the present embodiment is made of the above-mentioned non-halogen flame-retardant resin composition on the outer periphery of the core 5 formed by twisting two parallel insulated wires 1 and the inclusions 4 at the same time. The sheath 6 is a cable made in a non-crosslinked manner. Generally, the blending of the resin composition used for the insulator 3 is somewhat different from the blending of the resin composition used for the sheath 6, and details will be described later.

This cable 10 can be used, for example, as a round or flat elevator cable or a rubber insulated cable. As the conductor 2 , for example, a Cu or Cu alloy twisted wire, or a Cu or Cu alloy single wire is used. As the inclusions 4, polypropylene is used, for example.

Next, the operation of this embodiment will be described.

For the electric wire 1 and the cable 10, a resin containing a maleic acid-modified ethylene-propylene copolymer or a maleic acid-modified ethylene-butylene copolymer as a soft adhesive polymer is used as the insulator 3 and the sheath 6 combination. Therefore, compared with electric wires and cables using conventional resin compositions containing hard maleic acid-modified polymers, they are very soft and can greatly improve flexibility.

For example, in the examples described later, both the electric wire 1 and the cable 10 have a 10% modulus (tensile strength at 10% elongation) as an index of flexibility of 3 MPa or less.

In addition, the average particle size of the metal hydroxide is as small as 0.5 μm or less, and the metal hydroxide is uniformly dispersed in the resin composition, so the mechanical strength of the electric wire 1 and the cable 10 is improved and heat deformation is small. When producing the electric wire 1 and the cable 10, the extruded appearance of the resin composition also becomes good.

Furthermore, since the electric wire 1 and the cable 10 are pseudo-crosslinked by the metal hydroxide treated with methacrylic acid silane between the maleic acid-modified polymers bonded to polyolefin, they have sufficient mechanical strength even if they are not crosslinked. .

Thus, the electric wire 1 and the cable 10 can achieve both mechanical strength (tensile strength) and flexibility.

When high flame retardancy is required for electric wires and cables, it is necessary to mix a large amount of metal hydroxide in the mixed polymer, but even in this case, there is little decrease in mechanical strength.

The electric wire 1 and the cable 10 are coated with the resin composition according to this embodiment on the conductor 2 or the core 5, and are produced in a non-crosslinked manner. Since the resin composition is not crosslinked, it is not only flexible, but also can be easily recycled ( Reshaping), which is also a big advantage.

Since the electric wire 1 and the cable 10 do not contain halogen elements and phosphorus, no harmful gases such as hydrogen halide and phosphine will be produced when burned, and the safety in the event of a fire is high. Moreover, since the electric wire 1 and the cable 10 do not contain heavy metals, they do not cause environmental pollution when they are disposed of by incineration, landfill, etc., and are excellent in environmental performance.

The resin composition according to this embodiment is not limited to the electric wire 1 and the cable 10 shown in FIG. 1 , and can be used, for example, as a handrail of an escalator, a tail rope for an elevator, or a flame-retardant film.

Example

Embodiment (electric wire) 1～5

Put the polymers, antioxidants, flame retardants, and fillers shown in Table 1 into a kneader (8-inch open roll) kept at 100-130°C for mixing, and use a 40mm extruder kept at 180°C (L/D=24) Extrude the coated and kneaded resin composition on a copper twisted wire (conductor 2) with a cross-sectional area of 2 ^mm2 with a thickness of 1 mm to form an insulator 3, and make the insulation shown in Figure 1 in a non-crosslinked manner. Wire 1.

Embodiment (cable) 6～8

On the core 5 obtained by simultaneously twisting the insulated wire 1 of Example 3 and the polypropylene inclusion 4, the coating shown in Table 1 was extruded using a 40mm extruder (L/D=24) maintained at 180°C. A resin composition composed of polymers, antioxidants, flame retardants, and fillers forms the sheath 6 to make the cable 10 in FIG. 1 in a non-cross-linked manner.

Comparative example (wire) 1-4

Using the blended resin compositions shown in Table 1, insulated wires were produced in the same manner as in Examples 1 to 5.

The evaluation method of each electric wire and cable was performed as follows.

(1) Tensile properties

For electric wires, a tensile test was performed according to JIS C3005 using a tube obtained by drawing out a conductor. Also, for the cable, the sheath was stripped and cut into dumbbell size 3, and a tensile test was performed according to JIS K6251. The stretching speeds were all 200 mm/min. The targets for tensile strength and elongation are 10 MPa or more and 350% or more, respectively.

(2) Flexibility: 10% modulus

For flexibility, a tensile test was performed on a sample prepared in the same manner as the above-mentioned tensile test using a Tensioner (single yarn strength testing machine) according to JIS K6251, and the tensile strength at an elongation of 10% was measured. The stretching speed was 200 mm/min. The target of flexibility is 3.0MPa or less.

(3) heating deformation

For electric wires, a composition of the same quality as an insulator is molded into a plate shape with a width of 15mm, a length of 30mm, and a thickness of 2mm. This is used as a sample, and a load of 1.5kg is applied at 75°C according to JIS C3005. For cables, a sample with a length of 30mm is taken from the finished product, the inner surface is smoothed, and the same test as that of the electric wire is carried out. Deformation less than or equal to 10% is set as qualified.

(4) Flame retardancy

Flame retardancy at 60° tilt was evaluated for each electric wire and cable according to JIS C3005. The evaluation criterion is that the setting that extinguishes within 60 seconds or less after ignition is confirmed is considered acceptable, and the setting that continues to burn for more than 60 seconds is considered unqualified.

Table 1 shows the blending of the resin compositions of the electric wires and cables of Examples 1-5, Examples 6-8, and Comparative Examples 1-4 and their evaluation results. The compounding quantities in Table 1 are shown in parts by weight.

Table 1 type Example (Wire) Example (cable) Comparative example (wire) 1 2 3 4 5 6 7 8 1 2 3 4 Cooperate polymer Ethylene, propylene, and diene terpolymer (EP21, manufactured by JSR Corporation) 65 50 50 40 30 30 20 45 100 45 45 Ethylene-propylene copolymer (Tafma DF810, manufactured by Mitsui Chemicals Co., Ltd.) 30 35 Ethylene-butene copolymer (Tafma DF9200, manufactured by Mitsui Chemicals Co., Ltd.) 30 Ethylene-butene copolymer (Tafma DF9700, manufactured by Mitsui Chemicals Co., Ltd.) 10 10 15 15 15 LLDPE (density 0.921, comonomer: propylene) 10 20 EVA (VA content 33%, MFR0.2) 10 40 Maleic acid-modified ethylene-butene copolymer (Tafma MH7020, manufactured by Mitsui Chemicals Co., Ltd.) 5 20 40 40 60 40 65 40 40 Maleic acid-modified ethylene-propylene copolymer (Tafma MP0620, manufactured by Mitsui Chemicals Co., Ltd.) 30 60 Antioxidants イルガノツツクス 1010 (manufactured by Chiba Gaigi Co., Ltd.) 1 1 1 1 1 1 1 1 1 1 1 1 flame retardant Magnesium hydroxide (methacrylate silane treatment, average particle size 0.3μm) 40 60 150 50 40 60 60 Magnesium hydroxide (vinyl silane treatment, average particle size 0.3μm) 30 60 Magnesium hydroxide (vinyl silane treatment, average particle size 1.0 μm) 50 25 Magnesium hydroxide (stearic acid treatment, average particle size 1.0μm) 60 95 Filler Calcium carbonate (stearic acid treatment, average particle size 0.1μm) 20 20 20 20 20 20 20 20 20 20 20 20 Evaluation results Tensile strength (MPa) Target ≥10 12.6 13.6 11.4 10.8 11.5 13.2 11.6 12.4 6.2 16.7 7.8 9.2 Elongation (%) target ≥ 350 600 550 480 520 380 480 540 520 640 220 400 600 Flexibility 10% modulus (MPa) target ≤ 3.0 1.5 1.8 2.2 2 2.8 1.9 2.2 1.3 1 2.9 3.9 1.8 Heating deformation (75°C, 1.5kg) (%) Target ≤10 7.8 4.8 6.9 9.2 6.6 7.8 9.6 8.1 18 6.4 8.8 9.8 Flame retardancy (JIS gradient) qualified qualified qualified qualified qualified qualified qualified qualified qualified qualified qualified unqualified

As shown in Table 1, in Examples 1 to 5, the ratio of polyolefin and soft maleic acid modified polymer is within the specified range of the present invention, the tensile strength is 10.8 to 13.6 MPa, and the elongation is 380 to 380 MPa. 600%, all on target, good tensile properties. In addition, the 10% modulus was 1.5 to 2.8 MPa, all of which met the target, not only excellent in flexibility, but also small in heating deformation, and excellent in flame retardancy.

In addition, Examples 6 to 8 were the same as Examples 1 to 5, and the tensile strength was 12.4 to 13.2 MPa, and the elongation was 480 to 540%, all of which reached the target, and the tensile properties were good. In addition, the 10% modulus was 1.3 to 2.2 MPa, all of which met the target, not only excellent in flexibility, but also small in heating deformation, and excellent in flame retardancy.

On the contrary, in Comparative Example 1, since the mixed polymer is only composed of rubber-based materials and no maleic acid-modified polymer is used, even if magnesium hydroxide with an average particle size of 0.3 μm treated with methacrylic acid silane is mixed, the The tensile strength is also low, and the heating deformation is also large.

In Comparative Example 2, the elongation rate was low because the maleic acid-modified polymer was outside the specified range of the present invention. In Comparative Example 3, since the compounding amount of magnesium hydroxide was 155 parts by weight, which was outside the prescribed range of the present invention, the tensile strength was low and flexibility was also impaired. In Comparative Example 4, since there was little magnesium hydroxide, the flame retardancy was unacceptable.

Claims (4)

1. Non-halogen flame-retardant wires and cables, characterized in that they are non-halogen flame-retardant wires and cables coated with a resin composition obtained by mixing 30 to 150 parts by weight of metal with 100 parts by weight of a mixed polymer Hydroxide, the mixed polymer is a mixture of 40 to 95 parts by weight of polyolefin and 60 to 5 parts by weight of an olefinic copolymer modified with maleic anhydride, and the olefinic copolymer modified with maleic anhydride The copolymer is a maleic acid-modified ethylene-propylene copolymer or a maleic acid-modified ethylene-butene copolymer. 2. The non-halogen flame-retardant wire and cable according to claim 1, characterized in that the average particle size of the metal hydroxide is less than or equal to 0.5 μm, and its surface is treated with methacrylic silane. 3. The non-halogen flame-retardant wire and cable according to claim 1 or 2, characterized in that the resin composition coated is made in a non-crosslinked manner. 4. The non-halogen flame-retardant wire and cable according to any one of claims 1-3, characterized in that the 10% modulus of the non-halogen flame-retardant wire and cable is less than or equal to 3 MPa.

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