JP2017069130A - Insulation wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulation wire having flame resistance added and improved defect due to reduction of elongation and tensile strength.SOLUTION: An insulation wire has at least a center conductor 11 and an insulator 12 coating the periphery of the center conductor 11. The insulator 12 is manufactured by adding a flame retardant containing halogen and silica to a polyolefin resin and crosslinking them. The silica has average particle diameter of 0.1 to 1.0 μm and is added at 10 to 15 pts.wt. based on 100 pts.wt. of the polyolefin resin.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an insulated wire, and more particularly, to an insulated wire in which flame resistance is imparted to an insulator coated around a conductor.

   Insulated wires used for internal wiring of electronic equipment and automotive wiring are required to be flame retardant. For example, the United States UL (Under Writers Laboratories Inc.) standard and the Canadian CSA (Canadian Standards Association) standard A predetermined level of flame retardancy is required for an insulated wire used for a target electric device or electronic device, or a device that is subject to the upper limit of the use temperature of an insulator in the Electrical Appliance and Material Safety Law.

  As a flame retardant for enhancing the flame retardancy of an insulated wire, an inorganic filler such as silica may be blended with a resin compound such as a polyolefin resin. For example, Patent Document 1 discloses an insulated wire using a resin composition in which an inorganic filler and an organosilicon compound are blended with a polymer material. Here, it is described that a metal oxide such as silica is used as the inorganic filler. The particle size of the inorganic filler is preferably set in the range of 0.1 to 10 μm, and the blending amount is preferably 50 to 250 parts by weight with respect to 100 parts by weight of the polymer material. Yes. When forming an insulated wire, a composition containing the above inorganic filler and an organosilicic compound is extrusion coated onto a core conductor and irradiated with ionizing radiation such as an electron beam. Crosslink molecular material.

JP-A-6-256567

  With the compounding described in Patent Document 1, elongation (Elongation) and tensile strength at break (Tensile Strength) of an insulated wire that has been crosslinked by extrusion coating with addition of an inorganic filler or the like to a polymer material ), There is a need for an insulated wire having an insulator with better characteristics.

  This invention is made | formed in view of the situation mentioned above, and aims at provision of the insulated wire which improved elongation and tensile strength in the insulated wire to which a flame retardance is provided.

  An insulated wire according to the present invention is an insulated wire having at least a conductor and an insulator covering the periphery of the conductor, the insulator being made of a flame retardant containing halogen, silica, and polyolefin resin. In addition, the silica is an insulated wire having an average particle diameter of 0.1 to 1.0 μm and 10 to 15 parts by weight added to 100 parts by weight of the polyolefin-based resin. is there.

  ADVANTAGE OF THE INVENTION According to this invention, in the insulated wire to which a flame retardance is provided, the insulated wire which improved elongation and tensile strength can be provided.

It is a figure which shows the structural example of the insulated wire by this invention, and is a figure which shows the structure of the insulated wire which coat | covered the circumference | surroundings of the center conductor with the insulator. It is a figure which shows the structural example of the insulated wire by this invention, and is a figure which shows the structure of the coaxial electric wire which coat | covered the circumference | surroundings of the center conductor with the insulator, and was further provided with the external conductor, and the outer side of the external conductor was covered with the jacket. is there. It is a figure which shows the measurement result of elongation and tensile strength by the Example and comparative example of this invention.

First, embodiments of the present invention will be listed and described.
(1) The insulated wire of the present application is an insulated wire having at least a conductor and an insulator covering the periphery of the conductor, and the insulator is a polyolefin-based resin, a flame retardant containing halogen, Silica is added and crosslinked, and the silica has a particle size of 0.1 to 1.0 μm, and 10 to 15 parts by weight are added to 100 parts by weight of the polyolefin resin. It is. Thereby, in the insulated wire to which a flame retardance is provided, the insulated wire which improved the defect by extension and the fall of a tensile strength can be provided.

(2) The polyolefin resin is preferably a mixture of an ethylene / vinyl acetate copolymer resin and a polyethylene resin. Thereby, the polyolefin resin material suitable for a flame-retardant insulated wire is provided.

(3) The weight mixing ratio of the ethylene / vinyl acetate copolymer resin and the polyethylene resin is preferably in the range of 2: 8 to 5: 5. This gives an optimum mixing ratio of the ethylene / vinyl acetate copolymer resin and the polyethylene resin to improve defects due to elongation and decrease in tensile strength.

[Details of the embodiment of the present invention]
Specific examples of the insulated wire according to the present invention will be described below with reference to the drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and includes all the changes in a claim and the range equivalent to this.

1A and 1B are diagrams showing a configuration example of an insulated wire according to the present invention. An insulated wire 10 shown in FIG. 1A has a configuration in which a central conductor 11 is covered with an insulator 12.
In addition, in the insulated wire 10 shown in FIG. 1B, the periphery of the center conductor 11 is covered with an insulator 12, and an outer conductor 13 is provided on the outer periphery of the insulator 12. ) It is configured as a coaxial wire covered and protected by 14. The embodiment according to the present invention can be applied to both configurations of FIG. 1A and FIG. 1B.

  The insulator 12 of FIGS. 1A and 1B characterizes the embodiment according to the present invention. A flame retardant containing halogen and a silica are added to a polyolefin-based resin and crosslinked to form silica particles. A diameter is 0.1-1.0 micrometer, and 10-15 weight part of silica is added with respect to 100 weight part of polyolefin resin. Further, in the configuration of the insulated wire 10 in FIG. 1A, the center conductor 11 may be covered with a multilayer resin material. In this case, the innermost resin material layer coated around the central conductor 11 is a polyolefin resin layer in which the halogen flame retardant and silica are blended.

1A and 1B, the center conductor 11 is formed of a single wire or a stranded wire obtained by twisting a plurality of strands, such as copper, mild steel, silver, nickel-plated mild steel, tin-plated mild steel, silver-plated mild steel wire, etc. It is possible to use a material made of a conductive material. The center conductor 11 preferably has a cross-sectional area of ² to 40 mm ² .

The insulator 12 is added with a flame retardant containing halogen and silica, and is crosslinked by an electron beam or the like to the polyolefin resin.
As the polyolefin resin used as the base of the insulator 12, an ethylene / vinyl acetate copolymer or polyethylene can be used, and in particular, a mixture of the ethylene / vinyl acetate copolymer and polyethylene can be suitably used. . In this case, the weight mixing ratio of the ethylene / vinyl acetate copolymer and polyethylene is preferably in the range of 2: 8 to 5: 5. That is, in a two-component mixed system of ethylene / vinyl acetate copolymer and polyethylene, the weight mixing ratio of the ethylene / vinyl acetate copolymer is preferably in the range of 20% to 50%.
As the polyethylene, low density polyethylene (LDPE), linear low density polyethylene (L-LDPE), and high density polyethylene (HDPE) can be used. In addition, ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), etc. can be used as polyolefin resin.

  The flame retardant containing halogen imparts flame retardancy to the insulated wire 10, and an organic flame retardant containing a halogen atom can be used. For example, a brominated aromatic compound can be used as the halogen-based organic flame retardant. As the brominated aromatic compound, for example, polybromobiphenyl (PBB) or polybromodiphenyl ether (PBDE) can be used. In this embodiment, flame retardants such as metal hydroxides, metal oxides, and metal carbonates are not added, but these flame retardants may be used as necessary.

Silica is blended as an inorganic filler that imparts flame retardancy to the insulated wire 10. Moreover, the tensile strength of the insulator 12 can be increased by blending silica.
The silica particle size is preferably in the range of 0.1 to 1.0 μm, and preferably 10 to 15 parts by weight with respect to 100 parts by weight of the polyolefin resin serving as the base of the insulator 12. When the particle diameter of the silica is larger than the above range, the dispersibility of the silica inside the polyolefin resin is deteriorated, and the elongation and tensile strength of the polyolefin resin are lowered. In particular, when a mixture of an ethylene / vinyl acetate copolymer and polyethylene is used, silica having a large particle size is poor in dispersibility in polyethylene and causes elongation and a decrease in tensile strength. By optimizing the particle size of the silica in the range of 0.1 to 1.0 μm, it is possible to improve the dispersion of the silica with respect to the polyolefin resin and to prevent the elongation of the polyolefin resin and the decrease in the tensile strength. .
In addition to this, other compounding components such as a lubricant, an anti-aging agent, a processing aid, and a colorant can be appropriately mixed with the polyolefin-based resin serving as the base of the insulator 12 as necessary.

  In the case of the coaxial cable shown in FIG. 1B, the outer conductor 13 is formed by, for example, winding an annealed copper wire or a copper alloy wire, or a silver-plated or tin-plated annealed copper wire around the outer periphery of the insulator 12 by braiding or lateral winding. Alternatively, a metal tape is wound as the outer conductor 13. The jacket 14 can be made of the same material as the insulator 12. Alternatively, the jacket 14 can be appropriately configured by extruding and coating PVC (vinyl chloride resin), polyethylene resin, fluororesin material or the like, or winding a resin tape such as a polyester tape.

In the insulated wire 10 having the above configuration, the insulator 12 is given a three-dimensional network structure by being crosslinked. Here, the polyolefin resin containing the halogen-based flame retardant and the compounding agent such as silica as described above is extrusion-coated around the center conductor 11, and the extrusion-coated polyolefin resin is irradiated with an electron beam. A polyolefin resin can be crosslinked.
By irradiating with an electron beam as described above, the polyolefin resin can be effectively cross-linked in terms of cross-linking speed and simplicity, but in addition to this, other such as alpha rays, gamma rays, X-rays, ultraviolet rays, etc. The polyolefin resin may be crosslinked by irradiating with ionizing radiation, or a method such as kneading an organic peroxide in advance with the polyolefin resin and crosslinking by heating, or a method such as water crosslinking is adopted. May be.

  By blending the above structure, the conductor has at least an insulator covering the periphery of the conductor, and the insulator is cross-linked by adding a flame retardant containing halogen and silica to the polyolefin resin. An insulated wire having a configuration in which 10 to 15 parts by weight of silica having a particle size of 0.1 to 1.0 μm is added to 100 parts by weight of a polyolefin-based resin is provided. This polyolefin resin is a mixture of an ethylene / vinyl acetate copolymer resin and a polyethylene resin, and the weight mixing ratio thereof is preferably in the range of 2: 8 to 5: 5. By adding silica, flame retardancy to the polyolefin resin can be imparted and the tensile strength of the polyolefin resin can be increased. At this time, by making the particle diameter of the silica within the range of 0.1 to 1.0 μm, the dispersibility of the silica to the polyolefin resin is improved, the elongation of the polyolefin resin due to poor dispersion of the silica, and the decrease in the tensile strength Can be prevented. Thereby, in the insulated wire to which a flame retardance is provided, the insulated wire which improved the defect by extension and the fall of a tensile strength can be provided.

(Example)
In the configuration of FIG. 1A, a polyolefin resin is coated and molded around the center conductor 11 and cross-linked with an electron beam to form an insulated wire 10, and the elongation of the polyolefin resin (breaking elongation (%); Elongation) The tensile strength (tensile strength at break; Tensile Strength) was measured. The measurement results are shown in FIG.
The central conductor 11 was a stranded wire in which 41 tin-plated annealed copper wires having an outer diameter of 0.254 mmφ were twisted, and the cross-sectional area was 2 mm ² . As the polyolefin resin to be coated around the center conductor 11, a mixture of ethylene / vinyl acetate copolymer (EVA) and polyethylene (PE) at a weight ratio shown in FIG. 2 was used. The polyolefin resin was blended with a flame retardant containing halogen and silica. The compounding amount (parts by weight) relative to the average particle diameter (D50) of silica and the polyolefin resin (a mixture of EVA and PE) was changed. Then, a polyolefin resin containing the halogen-containing flame retardant and silica was extruded around the center conductor 11 to form a coating, and then irradiated with an electron beam to crosslink the polyolefin resin to obtain an insulated wire. The thickness of the coating layer made of polyolefin resin was 0.76 mm, and the outer shape of the insulated wire was 3.59 mm. The elongation and tensile strength of the polyolefin resin of this insulated wire were measured. As a measuring method, after crosslinking of the polyolefin resin, a 10 mm width sample was taken from the coating layer of the polyolefin resin, and the elongation at break and the strength at break (tensile strength) of the sample were measured by a tensile tester. .

No. 1 to No. 3 shown in FIG. 2 are examples, and No. 4 is a comparative example. In this configuration, it is necessary that the elongation is 400% or more and the tensile strength is 14.7 MPa (1.50 kg / mm ² ). No. In Example 1, the weight mixing ratio of EVA and PE is 4: 6, the average particle diameter of silica is 0.1 μm, and the blending amount of silica with respect to the mixture of EVA and PE is 15 parts by weight. The elongation at this time was 425%, the tensile strength was 16.9 MP, and both the elongation and the tensile strength were good levels.

No. In Example 2, the weight mixing ratio of EVA and PE is 5: 5, the average particle size of silica is 1.0 μm, and the blending amount of silica with respect to the mixture of EVA and PE is 10 parts by weight. The elongation at this time was 447%, the tensile strength was 15.5 MP, and both the elongation and the tensile strength were at a satisfactory level.
No. In Example 3, the weight mixing ratio of EVA and PE is 2: 8, the average particle diameter of silica is 0.1 μm, and the blending amount of silica with respect to the mixture of EVA and PE is 15 parts by weight. The elongation at this time was 409%, the tensile strength was 17.7 MP, and both the elongation and the tensile strength were good levels.
On the other hand, no. In Comparative Example 4, the weight mixing ratio of EVA and PE is 4: 6, the average particle diameter of silica is 6.0 μm, and the blending amount of silica with respect to EVA / PP is 10 parts by weight. The elongation at this time was 379%, the tensile strength was 14.5 MP, and neither the elongation nor the tensile strength was at a satisfactory level. Thereby, the average particle diameter of silica is 0.1 to 6.0 μm, the weight ratio of EVA to PE is in the range of 2: 8 to 5: 5, and the blending amount of silica with respect to EVA / PE is 10 to 15 parts by weight. Thus, an insulated wire having good elongation and tensile strength could be obtained.

DESCRIPTION OF SYMBOLS 10 ... Insulated electric wire, 11 ... Center conductor, 12 ... Insulator, 13 ... Outer conductor, 14 ... Outer jacket.

Claims (3)

An insulated wire having at least a conductor and an insulator covering the conductor,
The insulator is added to a polyolefin resin with a flame retardant containing halogen and silica, and is crosslinked.
The insulated wire has an average particle diameter of 0.1 to 1.0 μm, and is added to 10 to 15 parts by weight with respect to 100 parts by weight of the polyolefin resin.   The insulated wire according to claim 1, wherein the polyolefin-based resin is a mixture of an ethylene / vinyl acetate copolymer resin and a polyethylene resin. The insulated wire according to claim 2, wherein a weight mixing ratio of the ethylene / vinyl acetate copolymer resin and the polyethylene resin is in a range of 2: 8 to 5: 5.

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