JP2018092948A - Insulated wire and cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulated wire that can be reduced in its diameter even when having a flame-retardant layer with a high content of metal hydroxide as a flame retardant, and provide a cable.SOLUTION: An insulated wire 10 has a conductor 1, a flame-retardant inner layer 2 provided around the conductor 1 and containing metal hydroxide, and a moisture entry prevention layer 3 provided around the flame-retardant inner layer 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an insulated wire and a cable.

  Insulated wires used for internal wiring of electronic devices are required to have flame retardance so that the fire does not spread through the wires in the event of a fire accident of the device or the like. The flame retardance standard of the internal wiring material is determined by, for example, the UL758 standard in the United States.

  On the other hand, in Europe where the railway vehicle network is developed, the adoption of the regional standard called EN standard (European standard) is spreading, wear resistance, hydrolysis resistance, flame resistance, heat resistance, low smoke generation There is a demand for the use of materials having electrical properties (DC stability).

  In order to meet the requirements of such standards, conventionally, a flame retardant resin composition to which metal hydroxide such as magnesium hydroxide or aluminum hydroxide is added is used as a resin composition used for electric wires or cables. (For example, see Patent Document 1).

  In Patent Document 1, at least 10 to 100 parts by weight of calcined clay is added to 100 parts by weight of a conductor and a base polymer mainly composed of modified poly (2,6-dimethylphenylene ether) on the conductor. The inner layer coated with the resin composition, and further, on the basis of 100 parts by weight of the base polymer mainly composed of the polyester resin, 50 to 150 parts by weight of the polyester block copolymer, 0.5 to 0.5 parts of the hydrolyzable inhibitor A multilayer insulated wire having an outer layer coated with a polyester resin composition composed of 3 parts by weight and 10 to 30 parts by weight of magnesium hydroxide is disclosed.

JP 2013-214487 A

  However, a flame retardant layer containing a large amount of metal hydroxide as a flame retardant is liable to break down due to water absorption and does not function as an electrical insulation layer. Therefore, it is necessary to provide an electrical insulation layer as an inner layer.

  Recently, in particular, there has been a demand for reducing the diameter of insulated wires and cables, but it has been difficult to meet the demand for reducing the diameter of the conventional configuration.

  Then, the objective of this invention is providing the insulated wire and cable which can be reduced in diameter, even if it has a flame retardant layer containing many metal hydroxides as a flame retardant.

  In order to achieve the above object, the present invention provides the following insulated wires and cables.

[1] An insulated wire comprising a conductor, a flame retardant inner layer containing a metal hydroxide provided on the outer periphery of the conductor, and a moisture intrusion prevention layer provided on the outer periphery of the flame retardant inner layer.
[2] The insulated wire according to [1], wherein the flame retardant inner layer contains a metal hydroxide.
[3] The insulated wire according to [1] or [2], wherein the moisture intrusion prevention layer is made of an inorganic film having a thickness of less than 5 μm.
[4] The insulated wire according to [1] or [2], wherein the moisture intrusion prevention layer is made of a metal film having a thickness of less than 5 μm.
[5] The insulated wire according to [1] or [2], wherein the moisture intrusion prevention layer is formed of a high-density polymer film or a low-density polymer film having a thickness of 10 μm to 200 μm.
[6] The insulated wire according to [1], wherein the flame retardant inner layer is provided immediately above the conductor.
[7] A cable including the insulated wire according to any one of [1] to [6].

  ADVANTAGE OF THE INVENTION According to this invention, even if it has a flame retardant layer containing many metal hydroxides as a flame retardant, the insulated wire and cable which can be reduced in diameter can be provided.

It is a cross-sectional view which shows an example of the insulated wire which concerns on embodiment of this invention.

[Insulated wire]
An insulated wire according to an embodiment of the present invention includes a conductor, a flame retardant inner layer containing a metal hydroxide provided on the outer circumference of the conductor, and a moisture intrusion prevention layer provided on the outer circumference of the flame retardant inner layer. Is provided.

FIG. 1 is a cross-sectional view showing an example of an insulated wire according to an embodiment of the present invention.
As shown in FIG. 1, an insulated wire 10 according to the present embodiment includes a conductor 1, a flame retardant inner layer 2 containing a metal hydroxide provided on the outer circumference of the conductor 1, and an outer circumference of the flame retardant inner layer 2. And a moisture intrusion prevention layer 3 provided on the surface. It is preferable to further include a flame retardant outer layer 4 provided on the outer periphery of the moisture intrusion prevention layer 3.

(Conductor 1)
The conductor 1 is made of a general-purpose material such as pure copper, tin-plated copper, or aluminum. The number of conductors 1 is not limited to one as shown in FIG. 1, and a plurality of strands may be twisted. For example, a tin-plated annealed copper stranded wire can be suitably used. As the conductor 1, for example, a conductor having an outer diameter of about 0.15 to 7 mmφ can be used.

(Flame retardant inner layer 2)
The flame retardant inner layer 2 contains a metal hydroxide as a flame retardant.

  Examples of the metal hydroxide include magnesium hydroxide, aluminum hydroxide, hydrotalcite, calcium aluminate hydrate, calcium hydroxide, barium hydroxide and the like.

  The content of the metal hydroxide is preferably 80 parts by weight or more and 250 parts by weight or less, and preferably 150 parts by weight or more and 250 parts by weight or less with respect to 100 parts by weight of the base polymer constituting the flame retardant inner layer 2. More preferred.

  As the base polymer constituting the flame retardant inner layer 2, a general-purpose material, for example, a polyolefin such as a vinyl chloride resin, a fluorine resin, or polyethylene can be used.

  Examples of the vinyl chloride resin include a homopolymer of vinyl chloride (that is, polyvinyl chloride), a copolymer of vinyl chloride and another copolymerizable monomer (for example, vinyl chloride-vinyl acetate copolymer), and these A mixture is mentioned. If necessary, two or more types of vinyl chloride resins having different degrees of polymerization may be blended and used.

  Examples of fluororesin include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polytetrafluoroethylene (PTFE), ethylene / tetrafluoroethylene / hexafluoro. A propylene copolymer (EFEP), an ethylene-tetrafluoroethylene copolymer (ETFE), or the like can be used. These may be used alone or in combination. The fluororesin is desirably crosslinked.

  Examples of the polyolefin include polyethylene and polypropylene.

  The base polymer constituting the flame retardant inner layer 2 may include other flame retardants, flame retardant aids, fillers, crosslinking agents, crosslinking aids, plasticizers, stabilizers, ultraviolet absorbers, and light stabilizers as necessary. It is also possible to add additives such as lubricants, antioxidants, colorants, processability improvers, inorganic fillers, compatibilizers, foaming agents, antistatic agents and the like.

  The flame retardant inner layer 2 can be formed, for example, by coating the base polymer filled with a metal hydroxide filler on the outer periphery of the conductor 1 by molding means such as extrusion coating. Thereafter, crosslinking may be performed by a method such as electron beam irradiation.

  The thickness of the flame retardant inner layer 2 is preferably, for example, 30 μm or more and 300 μm or less.

  In the present embodiment, the flame retardant inner layer 2 may be composed of a single layer or may have a multilayer structure. Furthermore, you may give a separator, a braiding, etc. as needed.

(Water intrusion prevention layer 3)
The moisture intrusion prevention layer 3 provided on the outer periphery of the flame retardant inner layer 2 has a function of preventing moisture from entering the flame retardant inner layer 2 from the outside. For example, it is preferable to select a material / layer thickness at which the water vapor transmission rate measured by the JIS K7129 moisture sensor method (Lyssy method) is 50 g · m ⁻² · day or less, and 40 g · m ⁻² · day. It is more preferable to select materials / layer thicknesses that are as follows, and it is even more preferable to select materials / layer thicknesses that are 30 g · m ⁻² · day or less.

  The material of the moisture intrusion prevention layer 3 is not particularly limited as long as it has the above function, and is made of, for example, an inorganic film, a metal film, a high density polymer film, or a low density polymer film. It is preferable. These may be used alone or in combination of two or more.

The inorganic film is made of, for example, SiO ₂ , Al ₂ O ₃ , or TiO ₂ . The thickness of the inorganic film is preferably less than 5 μm, more preferably 1 μm or less, still more preferably 0.3 μm or less, and most preferably 0.15 μm or less. Further, the lower limit of the film thickness is preferably 10 nm or more, more preferably 30 nm or more, further preferably 50 nm or more, and most preferably 70 nm or more. When the film thickness is 5 μm or more, the flexibility of the electric wire or cable is not sufficient, and the film may be peeled off.

  The inorganic film is generated from inorganic alkoxy such as alkoxysilane, for example. It can be provided by spraying a material on the outer periphery of the flame retardant inner layer 2.

  The metal film is made of, for example, Au, Ag, Cu, Al, Ni, or Sn. A preferable film thickness is the same as that of the inorganic film. When the film thickness is 5 μm or more, the flexibility of the electric wire or cable is not sufficient, and the film may be peeled off.

  The metal film is generated by sputtering, for example. It can also be generated by electroless plating.

  The high-density polymer film is made of, for example, high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), or chlorine-based resin. The low density polymer film is made of, for example, low density polyethylene (LDPE). The film thickness of the high-density polymer film and the low-density polymer film is preferably from 10 μm to 200 μm, more preferably from 30 μm to 180 μm, and still more preferably from 50 μm to 150 μm.

  The high-density polymer film can be formed by extrusion coating. It may be formed by winding a high density polymer tape.

(Flame retardant outer layer 4)
The flame retardant outer layer 4 preferably contains a metal hydroxide as a flame retardant.

  As the metal hydroxide, those described above can be used.

  The content of the metal hydroxide is preferably 80 parts by weight or more and 250 parts by weight or less, and preferably 150 parts by weight or more and 250 parts by weight or less with respect to 100 parts by weight of the base polymer constituting the flame retardant outer layer 4. More preferred.

  As the base polymer constituting the flame retardant outer layer 4, the same ones as described above for the flame retardant inner layer 2 can be used.

  The flame retardant outer layer 4 is preferably made of the same resin composition as the flame retardant inner layer 2.

  The flame retardant outer layer 4 can be formed, for example, by coating the outer periphery of the moisture intrusion prevention layer 3 with a base polymer filled with a metal hydroxide filler by a molding means such as extrusion coating. Thereafter, crosslinking may be performed by a method such as electron beam irradiation.

  The thickness of the flame retardant outer layer 4 is preferably 50 μm or more and 450 μm or less, for example. Since the total thickness of the flame retardant inner layer 2 and the flame retardant outer layer 4 only needs to be the same thickness as the flame retardant layer of the conventional insulated wire, there is no need to provide a separate electric insulation layer. The insulated wire 10 according to the embodiment is suitable for reducing the diameter.

  In the present embodiment, the flame retardant outer layer 4 may be composed of a single layer or may have a multilayer structure. Furthermore, you may give a separator, a braiding, etc. as needed.

  The insulated wire 10 may be provided with a layer other than the above within the range where the effects of the present invention are exhibited. For example, an electrical insulating layer made of polyethylene or the like not containing a flame retardant may be provided between the conductor 1 and the flame retardant inner layer 2 or between the flame retardant inner layer 2 and the moisture intrusion prevention layer 3. However, from the viewpoint of reducing the diameter, it is preferable not to provide it. Even if it is provided, the layer thickness is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less.

〔cable〕
The cable which concerns on embodiment of this invention is equipped with the said insulated wire which concerns on embodiment of this invention, It is characterized by the above-mentioned.

  The cable according to the present embodiment includes, for example, an insulated wire 10 and a sheath that is extrusion-coated on the outer periphery thereof. The insulated wire 10 may be a multi-core stranded wire.

[Effect of the embodiment of the present invention]
According to the embodiment of the present invention, by providing the moisture intrusion prevention layer 3 and the flame retardant inner layer 2 on the inner side thereof, the flame retardant inner layer 2 also functions as an electric insulating layer. Therefore, it is necessary to separately provide an electric insulating layer. Since there is no, even if it has a flame retardant layer containing many metal hydroxides as a flame retardant, the insulated wire and cable which can be reduced in diameter can be provided.

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

  The insulated wire 10 having the structure shown in FIG. 1 was manufactured and evaluated by the following method.

[Production of insulated wires]
The outer periphery of a tin-plated conductor with an outer diameter of 1.23 mm (a twisted conductor obtained by twisting 37 strands with a diameter of 0.18 mm) is coated with the flame-retardant inner layer 2 with a 40 mm extruder, and moisture enters the flame-retardant inner layer 2 The prevention layer 3 was coated, and the flame retardant outer layer 4 was coated on the moisture intrusion prevention layer 3. As materials for the flame retardant inner layer 2 and the flame retardant outer layer 4, resin compositions having the formulations shown in Table 1 below were used. As materials for the moisture intrusion prevention layer 3, Examples 1-4, 7 and 8 are high-density polyethylene (manufactured by Prime Polymer Co., Ltd., trade name: Hi-Zex (registered trademark) 5305E, MFR: 0.8 g / 10 min, density: 0.951 / cm ³ ) 100 parts by mass, a resin composition obtained by kneading 1 part by mass of a hindered phenolic antioxidant (manufactured by BASF, trade name: Irganox 1010), Examples 5 and 6 are low density polyethylene (Ube Maruzen) Product name: UBE polyethylene (registered trademark) UBE C450, MFR: 1 g / 10 min, density: 0.921 / cm ³ ) 100 parts by mass, hindered phenol antioxidant (manufactured by BASF Corporation, product name) Irganox 1010) A resin composition kneaded with 1 part by mass was used. The thickness of each layer was molded as shown in Table 2 below.

[Measurement of water vapor permeability of moisture intrusion prevention layer 3]
As a measurement sample, a film corresponding to the moisture intrusion prevention layer 3 of each example was produced on a plate glass. The water vapor transmission rate was measured by the JIS K7129 moisture sensor method (Lyssy method).

[Evaluation of insulated wires]
The produced insulated wire was evaluated by the following method. The evaluation results are shown in Table 2.

(1) Electrical property test
A 300V DC stability test was performed in accordance with EN50305.6.7. Those that were not short-circuited for 240 hours were accepted, and those that were short-circuited for less than 240 hours were rejected.

(2) Flame retardancy test Flame retardancy was evaluated by the following VFT and VTFT.
(VFT)
A vertical combustion test (VFT = Vertical Flame Test) was performed. A 600 mm long insulated wire was kept vertical, and a flame was applied to the insulated wire for 60 seconds. After removing the flame, the fire extinguisher within 30 seconds was passed (◎), the fire extinguished within 31 seconds to 60 seconds was passed (○), and the fire extinguished within 60 seconds was rejected ( X).
(VTFT)
Based on EN50266-2-4, a vertical tray burning test (VTFT = Vertical Ray Flame Test) was performed. Specifically, an insulated wire with a total length of 3.5 m is made into one bundle of 7 twists, 11 bundles are arranged vertically at equal intervals, burned with a burner for 20 minutes from below the insulated wire, self-extinguishing, carbonized The target length was 2.5 m or less from the lower end. If the carbonization length is 1.5 m or less, it will be accepted (）), if the carbonization length exceeds 1.5 m and 2.5 m or less, it will be accepted (◯), and if it exceeds 2.5 m, it will be rejected. (X).

〔Comprehensive judgment〕
As a comprehensive judgment, all the evaluations of the above tests are passed (◎), the DC stability test and VFT evaluation are passed, and VTFT is rejected (○), the DC stability test And VFT were rejected (x).

  In addition, this invention is not limited to the said embodiment and Example, A various deformation | transformation implementation is possible.

10: insulated wire 1: conductor, 2: flame retardant inner layer, 3: moisture intrusion prevention layer, 4: flame retardant outer layer

Claims (7)

  An insulated wire comprising a conductor, a flame retardant inner layer containing a metal hydroxide provided on the outer periphery of the conductor, and a moisture intrusion prevention layer provided on the outer periphery of the flame retardant inner layer.   The insulated wire according to claim 1, wherein the flame retardant inner layer contains a metal hydroxide.   The insulated wire according to claim 1 or 2, wherein the moisture intrusion prevention layer is made of an inorganic film having a thickness of less than 5 µm.   The insulated wire according to claim 1, wherein the moisture intrusion prevention layer is made of a metal film having a thickness of less than 5 μm.   The insulated wire according to claim 1 or 2, wherein the moisture intrusion prevention layer is made of a high-density polymer film or a low-density polymer film having a thickness of 10 µm to 200 µm.   The insulated wire according to claim 1, wherein the flame retardant inner layer is provided immediately above the conductor.   The cable provided with the insulated wire of any one of Claims 1-6.

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