JP6123666B2 - Non-halogen flame retardant polyester insulated wire - Google Patents

Description

  The present invention relates to a halogen-free flame retardant polyester insulated wire.

  Electric wires and cables used in the vicinity of engines or motors such as railway vehicles and automobiles are required to have high heat resistance, wear resistance, flame resistance, and the like as necessary. In order to satisfy such a requirement, an engineering plastic having a high melting point may be used. For example, it is known to use a halogen-based or phosphorus-based flame retardant for flame retardant in the case of using polyester typified by polybutylene terephthalate (PBT).

  However, halogen-based flame retardants generate halogen gas during combustion, and thus lack consideration for environmental problems that are increasing worldwide. Therefore, non-halogen flame retardants such as magnesium hydroxide have been used (see Patent Document 1).

  On the other hand, electric wires and cables wired to railway vehicles, automobiles, electronic devices and the like need to have high insulation performance depending on the environment in which they are used. For example, a technique is known in which a polyolefin such as polyethylene having excellent electrical insulation is coated directly on a conductor, and a non-halogen flame retardant resin composition based on polyester such as PBT is coated thereon (Patent Document). 1).

Japanese Patent No. 4330603

  However, since the polyolefin layer and the polyester layer have poor adhesion, there is a problem that peeling occurs during bending and the direct current stability is lowered. In order to solve this problem, there is a technique of applying maleic acid-modified polyolefin to the inner layer. However, the problem is that the adhesiveness to the conductor is high and the wire end workability is defective.

  Accordingly, an object of the present invention is to provide a non-halogen flame retardant polyester insulated electric wire having excellent flame retardancy and direct current stability and good wire end workability.

  In order to achieve the above object, according to the present invention, the following non-halogen flame retardant polyester insulated wires are provided.

[1] An inner layer made of a resin composition mainly composed of a nonpolar polyolefin is coated on the outer periphery of the conductor, and an intermediate layer composed of a resin composition mainly composed of an olefin resin having a glycidyl group is directly above the inner layer. A non-halogen flame retardant polyester insulated electric wire characterized in that an outer layer made of a flame retardant resin composition mainly composed of polyester containing a non-halogen flame retardant is coated directly on the intermediate layer.
[2] The nonpolar polyolefin is low density polyethylene, medium density polyethylene, high density polyethylene, very low density polyethylene, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer. The non-halogen flame retardant polyester insulated wire according to [1] above, which is one or more selected from polymers.
[3] The olefin resin is one or two selected from an ethylene-glycidyl methacrylate copolymer and an ethylene-glycidyl methacrylate-methyl acrylate copolymer. [2] Non-halogen flame retardant polyester insulated wire according to [2].
[4] In any one of [1] to [3], the polyester is one or two selected from polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN). Non-halogen flame retardant polyester insulated wire as described.
[5] The non-halogen flame retardant polyester insulated electric wire according to any one of [1] to [4], wherein the non-halogen flame retardant is magnesium hydroxide.
[6] The non-halogen flame-retardant polyester insulated wire according to [5], wherein the magnesium hydroxide is contained in an amount of 10 to 50 parts by mass with respect to 100 parts by mass of the polyester.
[7] The non-halogen flame-retardant polyester insulated electric wire according to any one of [1] to [6], wherein the inner layer and the intermediate layer are subjected to crosslinking treatment by electron beam irradiation.

  ADVANTAGE OF THE INVENTION According to this invention, the non-halogen flame-retardant polyester insulated electric wire which has the outstanding flame retardance and direct current | flow stability, and favorable electric wire end workability is provided.

It is a cross-sectional view of the non-halogen flame retardant polyester insulated wire according to an embodiment of the present invention.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a cross-sectional view of a non-halogen flame retardant polyester insulated wire according to an embodiment of the present invention.

In the non-halogen flame-retardant polyester insulated wire 10 according to the embodiment of the present invention, an outer layer of a conductor 1 is coated with an inner layer 2 made of a resin composition mainly composed of a nonpolar polyolefin, and an olefin having a glycidyl group immediately above the inner layer 2. An intermediate layer 3 made of a resin composition containing a resin as a main component is coated, and an outer layer 4 made of a flame retardant resin composition containing a polyester containing a non-halogen flame retardant as a main component is coated directly on the intermediate layer 3. It is.

  The conductor 1 is made of a general-purpose material such as pure copper or tin-plated copper.

(Inner layer 2)
For the inner layer 2, a resin composition mainly composed of nonpolar polyolefin is used. The non-polar polyolefin, it is preferable electric characteristics at the time of flooding is a good hygroscopic low Ipoh Li olefins. Specifically, low density polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, and the like. It is mentioned as a suitable thing. These may be used alone or in combination of two or more.

  When a metal hydroxide is added as a flame retardant, a small amount (for example, 0.5 to 10 parts by mass) of an acid-modified polyolefin may be blended for the purpose of improving adhesion to the metal hydroxide. Good. Examples of the acid include maleic acid, maleic anhydride, and fumaric acid.

  The polyolefin content in the resin composition is preferably 50% by mass or more, and most preferably 100% by mass.

  When higher flame retardancy is required, a metal hydroxide can be added. The amount of the metal hydroxide added is preferably 50 to 250 parts by mass, more preferably 75 to 150 parts by mass with respect to 100 parts by mass of the polyolefin, considering the balance between flame retardancy and mechanical properties. .

  Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like. The endothermic amount at the time of decomposition of calcium hydroxide is about 1000 J / g, whereas the endothermic amounts of aluminum hydroxide and magnesium hydroxide are as high as 1500 to 1600 J / g, and the flame retardancy is good. It is preferable to use aluminum or magnesium hydroxide. These may be used alone or in combination of two or more.

  The metal hydroxide can be subjected to a surface treatment with a silane coupling agent, a titanate coupling agent, a fatty acid such as stearic acid, and the like in consideration of dispersibility. Of these, a silane coupling agent is desirable in terms of enhancing the adhesion between the resin composition and the metal hydroxide. As the silane coupling agent, known materials can be used, and the surface treatment method can also be performed by a known method.

  The resin composition may include a crosslinking agent, a crosslinking aid, a flame retardant aid, an ultraviolet absorber, a light stabilizer, a softener, a lubricant, a colorant, a reinforcing agent, a surfactant, and an inorganic filler as necessary. Plasticizers, metal chelating agents, foaming agents, compatibilizers, processing aids, stabilizers, and the like can be added.

  The thickness of the inner layer 2 is preferably 0.03 to 0.15 mm, and more preferably 0.06 to 0.1 mm.

(Intermediate layer 3)
For the intermediate layer 3, a resin composition mainly composed of an olefin resin having a glycidyl group is used. In the olefin resin having a glycidyl group, the glycidyl group is effective in improving the adhesion because it is excellent in the reaction with the carbonyl of the polyester forming the outer layer 4. A glycidyl group-containing olefin-based copolymer is preferable, and among them, an ethylene-glycidyl methacrylate copolymer and an ethylene-glycidyl methacrylate-methyl acrylate copolymer are preferable because of excellent affinity with the polyolefin forming the inner layer 2. These may be used alone or in combination of two or more. A compound having a glycidyl group includes glycidyl methacrylate (GMA), and such a compound can be blended with a polyolefin such as polyethylene.

  The content of the olefin resin having a glycidyl group in the resin composition is preferably 50% by mass or more, and most preferably 100% by mass.

  In the resin composition, if necessary, a flame retardant, a crosslinking agent, a crosslinking aid, a flame retardant aid, an ultraviolet absorber, a light stabilizer, a softener, a lubricant, a colorant, a reinforcing agent, a surfactant, Inorganic fillers, plasticizers, metal chelating agents, foaming agents, compatibilizers, processing aids, stabilizers, and the like can be added.

  The thickness of the intermediate layer 3 is preferably 0.01 to 0.08 mm, and more preferably 0.03 to 0.05 mm.

(Crosslinking treatment)
The non-polar polyolefin of the inner layer 2 and the olefin resin having a glycidyl group of the intermediate layer 3 are preferably sufficiently crosslinked. The crosslinking treatment is preferably performed by electron beam irradiation, and the dose of the electron beam is not particularly limited, but is preferably 1 to 20 Mrad.

(Outer layer 4)
For the outer layer 4, a flame retardant resin composition mainly composed of polyester containing a non-halogen flame retardant is used. Examples of the polyester include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polybutylene naphthalate (PBN). Among these, PBT and PBN are preferable because they have a low melting point, and can be kneaded, for example, at or below the decomposition temperature of magnesium hydroxide, and there is little concern about hydrolysis.

  Examples of the non-halogen flame retardant contained in the flame retardant resin composition include red phosphorus typified by phosphorus flame retardants, other phosphorus compounds, and metal hydroxides.

  Phosphorus compounds include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl phenyl phosphate, cresyl di 2,6-xylenyl phosphate, resorcinol bis-diphenyl phosphate, resorcinol bis -Aromatic condensed phosphate esters such as dixylenyl phosphate and bisphenol A bis (diphenyl phosphate), phosphazene compounds and the like.

  Examples of the metal hydroxide include aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like. Among these, magnesium hydroxide is preferable because it has a high endotherm during decomposition. In consideration of dispersibility and the like, the metal hydroxide can be subjected to surface treatment as necessary with a silane coupling agent, a titanate coupling agent, a fatty acid such as stearic acid, and the like.

  The content of the polyester in the resin composition is preferably 50% by mass or more, and most preferably 100% by mass.

  For the resin composition, as necessary, a crosslinking agent, a crosslinking aid, an ultraviolet absorber, a light stabilizer, a softener, a lubricant, a colorant, a reinforcing agent, a surfactant, an inorganic filler, a plasticizer, a metal Chelating agents, foaming agents, compatibilizers, processing aids, stabilizers and the like can be added.

  The thickness of the outer layer 4 is preferably 1 mm or less.

  The non-halogen flame retardant polyester insulated wire according to the embodiment of the present invention is not limited to three layers as long as the inner layer, the intermediate layer, and the outer layer are provided, and as long as the effects of the present invention are exhibited, the outer layer It is also possible to have a coating layer on the outer side, and the inner layer, intermediate layer, and outer layer may each be composed of a plurality of layers.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

[Production of non-halogen flame-retardant polyester insulated wires of Examples and Comparative Examples]
A non-halogen flame retardant polyester insulated wire having the structure of FIG. 1 was produced by the following method.

  A tin-plated conductor having a structure of 19 / 0.26 mm was coated with an inner layer, an intermediate layer was coated on the inner layer, and an outer layer was coated on the intermediate layer to form an insulating coating layer. As the inner layer material, a resin composition in which 100 parts by mass of low density polyethylene and 100 parts by mass of magnesium hydroxide were kneaded was used. As the material for the intermediate layer, ethylene-glycidyl methacrylate was used. In Comparative Example 2, high density polyethylene was used. As the material for the outer layer, resin compositions having the formulations shown in Tables 1 and 2 were used.

  The inner layer, the intermediate layer, and the outer layer were subjected to three-layer extrusion with a 65 mm extruder so that the inner layer had a thickness of 0.1 mm, the intermediate layer had a thickness of 0.05 mm, and the outer layer had a thickness of 0.1 mm. The obtained electric wire was irradiated with an electron beam for crosslinking.

  In Comparative Example 1, no halogen-free flame retardant was used for the outer layer. In Comparative Example 2, high-density polyethylene was used as the intermediate layer instead of ethylene-glycidyl methacrylate. In the conventional example, no intermediate layer was provided. In Comparative Example 3, no inner layer was provided.

[Materials used] (Numbers correspond to the numbers in Tables 1 and 2)
1) PBT: Made by Mitsubishi Engineering Plastics, (trade name) Nova Duran 5026
2) Magnesium hydroxide: manufactured by Kyowa Chemical, (trade name) Kisuma 5L
3) Phosphorus compound: manufactured by Daihachi Chemical Industry, (trade name) PX-200
4) Ethylene-glycidyl methacrylate: manufactured by Sumitomo Chemical Co., Ltd. (trade name) Bond First 2C
5) Low density polyethylene: Prime polymer, (trade name) Evolue SP1510
6) High density polyethylene: made of prime polymer, (trade name) Hi-Zex 5305E

[Evaluation of insulated wires of Examples and Comparative Examples]
The insulated wire produced by the above procedure was evaluated by the following method. The measurement results are shown in Tables 1 and 2.

(Evaluation of wire end workability)
The case where the insulating coating layer was removed without resistance with a wire stripper was rated as “◯” (passed), and the case where it was difficult to pull out was rated as “x” (failed).

(Peel test)
An insulated wire is wound around a self-diameter mandrel, and a gap is not generated between the inner layer and the intermediate layer or between the intermediate layer and the outer layer. .

(DC stability test)
After winding an insulated wire around a self-diameter mandrel and then loosening it from the mandrel, it is immersed in 3% salt water at 85 ° C in accordance with EN50264-3-1, paragraph 7.7, minus 0.3 kV minus electricity, and direct current stability The test was conducted. The thing which does not short-circuit for 10 days was set as (circle) (pass), and the thing which short-circuits in less than 10 days was set as x (failed).

(Flame retardance evaluation)
The insulated wire was kept horizontal, applied with a flame for 10 seconds, removed the flame and then extinguished within 30 seconds. The number of tests was set to 5 times, ○ for those that passed 5 times, Δ for 4 to 1 times, and × for those that never passed.

(Comprehensive evaluation)
As a comprehensive evaluation, all of the above test results were evaluated as “、”, “◯” and “Δ” as only ○, and “x”.

  As shown in Table 1, in Examples 1 to 3 according to the present invention, the overall evaluations were ◯ to ◎.

  On the other hand, as shown in Table 2, in Comparative Example 1 in which a non-halogen flame retardant was not used in the outer layer, none passed in the combustion test.

  In Comparative Example 2 in which high-density polyethylene was used as the intermediate layer, peeling occurred between the outer layer and the intermediate layer, and the DC stability test failed.

  In the conventional example in which the intermediate layer was not provided, peeling occurred between the outer layer and the intermediate layer, and the DC stability test failed.

  In Comparative Example 3 in which the inner layer was not provided, the insulating coating layer was difficult to come off, so the wire end workability was unacceptable.

From the above, if the resin composition mainly composed of an olefin resin having a glycidyl group is not used in the intermediate layer, peeling from the outer layer occurs, and excellent DC stability cannot be obtained, and the flame retardant is added to the outer layer polyester. It was found that sufficient flame retardancy could not be obtained without adding, and good wire end workability could not be obtained unless an inner layer composed mainly of nonpolar polyolefin was provided.

1: conductor, 2: inner layer, 3: intermediate layer, 4: outer layer, 10: insulated wire

Claims (7)

An inner layer made of a resin composition mainly composed of nonpolar polyolefin is coated on the outer periphery of the conductor, and an intermediate layer made of a resin composition mainly composed of an olefin resin having a glycidyl group is directly coated on the inner layer, A non-halogen flame retardant polyester insulated wire, wherein an outer layer made of a flame retardant resin composition mainly comprising a polyester containing a non-halogen flame retardant is coated directly on the intermediate layer. The nonpolar polyolefin is selected from low density polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, and ethylene-octene-1 copolymer. The non-halogen flame retardant polyester insulated electric wire according to claim 1, wherein the non-halogen flame retardant polyester insulated electric wire is one type or two or more types selected.   The said olefin resin is 1 type or 2 types chosen from an ethylene-glycidyl methacrylate copolymer and an ethylene-glycidyl methacrylate-methyl acrylate copolymer, The Claim 1 or Claim 2 characterized by the above-mentioned. Non-halogen flame retardant polyester insulated wire.   The non-halogen flame-retardant polyester according to any one of claims 1 to 3, wherein the polyester is one or two selected from polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN). Insulated wire.   The non-halogen flame retardant polyester insulated electric wire according to any one of claims 1 to 4, wherein the non-halogen flame retardant is magnesium hydroxide.   The non-halogen flame-retardant polyester insulated wire according to claim 5, wherein the magnesium hydroxide is contained in an amount of 10 to 50 parts by mass with respect to 100 parts by mass of the polyester.   The non-halogen flame retardant polyester insulated electric wire according to any one of claims 1 to 6, wherein the inner layer and the intermediate layer are subjected to crosslinking treatment by electron beam irradiation.

Images