JPH10340637A - Insulated wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide sufficient flame resistance, and improve abrasion resistance and heating deformation resistance by laminating an inner layer composed of a polypropylene-polybutene alloyed resin and the specific composition of a metallic hydroxide and an outer layer composed of a polyamide resin on an outer periphery, and setting the thickness dimension ratio of the inner layer to the outer layer to a specific value. SOLUTION: An outer periphery of a copper conductor 1 is covered with an insulating layer composed of an inner layer 2 and an outer layer 3, and the inner layer 2 is composed of a resin composition by blending a metallic hydroxide by 50 to 400 pts.wt. to 100 pts.wt. of a polypropylene-polybutene alloyed resin. The outer layer 3 is composed of a polyamide resin, and the thickness dimension ratio of the inner layer 2 to the outer layer 3 is set to the inner layer 2/the outer layer 3=6/4 to 9/1. In this case, since the polypropylene-polybutene alloyed resin is excellent in flame resistance and flexibility, these characteristics and be enhanced in the inner layer 2, and in the outer layer 3, heating deformation resistance and abrasion resistance can be improved by the use of the polyamide resin, and economical efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-layer insulated wire having excellent properties such as abrasion resistance, flame retardancy, and heat deformation resistance.

[0002]

2. Description of the Related Art For example, as an insulating covering material used for insulated wires for automobiles, from the viewpoint of appropriate flexibility and flame retardancy,
Polyvinyl chloride resin is used more often than ever. However, when this wire is incinerated and disposed of with the scrapping of vehicles, the insulation coating burns in the incinerator, generating hydrogen chloride gas, damaging the incinerator or being discharged into the atmosphere, resulting in environmental pollution. Has the problem of causing

[0003] Therefore, in recent years, electric wires using a flame-retardant resin composition containing no halogen component such as chlorine as an insulating coating material have been studied, and the structure thereof is a mixture of a polyolefin resin and a metal hydroxide. Things are common.

[0004]

However, conventional flame-retardant resin compositions of this type are inferior in flexibility and flexibility as compared with polyvinyl chloride, and have a large amount of metallic water to provide flame retardancy. Mixing the oxide has a problem that mechanical strength such as wear resistance and tensile strength is reduced.

Therefore, as shown in, for example, JP-A-6-176631, a flame-retardant olefin material containing a large amount of a flame retardant is used in the inner layer, and an olefin resin containing little or no flame retardant is contained in the outer layer. Are considered.

However, such an example has a problem that the insulated wire is easily deformed at a high temperature.

Accordingly, an object of the present invention is to provide an insulating material which does not generate harmful gas during incineration, has excellent flexibility and bendability, has sufficient flame retardancy, and has excellent wear resistance and heat deformation resistance. To provide the wires.

[0008]

The insulated wire according to the present invention is an insulated wire in which an outer peripheral layer of a conductive core is covered with an insulating layer composed of an inner layer and an outer layer, and the inner layer is formed of a polypropylene / polybutene alloy resin by weight. On the other hand, 50
The outer layer is made of a polyamide resin, and the thickness ratio of the inner layer and the outer layer is such that the inner layer / outer layer = 6/4 to 9/1. You.

In the present invention, the reason why the polypropylene / polybutene alloyed resin is used for the inner layer is that the other hard resins are insufficient in flexibility and cold resistance. As the metal hydroxide, magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like are preferable. The average particle size of these metal hydroxides is preferably from 0.1 to 5 μm from the viewpoint of dispersibility in a polymer, workability, electric wire characteristics, and the like. The objective of can be achieved. In addition, for the purpose of preventing aggregation of the metal hydroxide, improving dispersibility in the polymer, and improving adhesion to the polymer, surface treatment is performed using a silane coupling agent, a titanate coupling agent, a fatty acid and a metal salt thereof, and the like. It is preferable to use those that have been used.

In the inner layer, 5 parts of metal hydroxide are added to 100 parts by weight of the polypropylene / polybutene alloyed resin.
0 to 400 parts by weight, but if the amount is less than 50 parts by weight, the flame retardancy of the wire is insufficient, and if the amount is more than 400 parts by weight, the whitening resistance and flexibility, the abrasion resistance, and the tensile strength of the wire are further reduced. This is due to lack of quality.

In the present invention, a polyamide resin is used for the outer layer. This is because the use of a soft resin other than the polyamide resin results in insufficient heat deformation resistance and wear resistance. Furthermore, in order to enhance the flame retardancy, a flame retardant auxiliary such as hydrotalcites, silica, carbon black, zinc borate, and a phosphorus compound may be added.
An antioxidant, a lubricant, a dispersant, a copper damage inhibitor, a cross-linking agent, a cross-linking aid or a colorant may be added, and the polymer may be cross-linked by various cross-linking methods.

The thickness dimension ratio of the inner layer and the outer layer is defined as inner layer / outer layer =
The reason why the ratio is 6/4 to 9/1 is that if the ratio is 6/4 or less, the insulated wire has insufficient flexibility, and if it is 9/1 or more, the wear resistance and the tensile strength are insufficient.

[0013]

As described above, according to the insulated wire of the present invention, the polypropylene / polybutene alloyed resin is more flame-retardant than the commonly used polyolefin resin.
Because of excellent flexibility, these properties can be enhanced in the inner layer.

On the other hand, since the polyamide resin used for the outer layer is generally more expensive than the olefin resin, it is economically unsuitable to apply it to a flame-retardant formulation and use it for general-purpose electric wires. However, as a result of increased flame retardancy in the inner layer,
In the outer layer, it has become possible to use a polyamide resin which is excellent in economical efficiency while taking advantage of the property of being excellent in heat deformation resistance and abrasion resistance.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below.

As Example 1 of the present invention, a resin obtained by kneading a polypropylene / polybutene alloyed resin, a polyamide resin, aluminum hydroxide, magnesium hydroxide, and silica and red phosphorus as flame retardant aids in the proportions shown in Table 1. A composition was made.

On the other hand, as Comparative Examples 1 to 8, polypropylene / polybutene alloyed resin, ethylene-vinyl acetate copolymer (vinyl acetate content = 20%), ethylene-ethyl acrylate copolymer (ethyl acrylate content = 25
%), High density polyethylene (melting point = 135 ° C, Shore D)
Hardness = 63), low density polyethylene (melting point = 98 ° C., Shore D hardness = 48), linear low density polyethylene (melting point = 110 ° C., Shore D hardness = 58), polyamide resin,
A resin composition was prepared by kneading aluminum hydroxide, magnesium hydroxide, silica, and red phosphorus at the ratios shown in Tables 2 and 3.

The ethylene-vinyl acetate copolymer is Ultracene (trade name) manufactured by Tosoh Corporation, the ethylene-ethyl acrylate copolymer is Evaflex EEA (trade name) manufactured by DuPont-Mitsui Polychemicals, and high-density polyethylene is Japan. J-LEX HD (trade name) manufactured by Polyolefin,
The low-density polyethylene used was Jakelex LD (trade name) manufactured by Japan Polyolefin Co., Ltd. The linear low-density polyethylene used was Jakex LL (trade name) manufactured by Japan Polyolefin Co., Ltd., and the polyamide resin was nylon (trade name) manufactured by Ube Industries.

As shown in FIG. 1, these resin compositions were subjected to the following characteristic evaluation using a thin electric wire prepared by extruding an inner layer 2 and an outer layer 3 on the outer periphery of a copper core wire 1 to the thicknesses shown in the respective tables. went. Flame retardancy: A 300 mm long wire sample is supported horizontally, and the tip of the reducing flame is applied from below the center of the sample using a Bunsen burner with a diameter of 10 mm until it burns within 30 seconds.
After gently removing the flame, the degree of combustion of the sample was determined. Abrasion resistance: At room temperature of 23 ± 5 ° C., the insulating coating surface of a 750 mm long wire sample fixed on a table is reciprocated and abraded by a blade over a length of 10 mm or more in the axial direction. When the blade is reciprocated 50 or 60 times per minute,
The number of reciprocations until the blade contacts the core conductor due to wear of the insulator is measured. Next, the sample is moved 100 mm, rotated 90 degrees clockwise, and the above measurement is repeated.
This measurement was performed a total of four times with the same sample, and the minimum value was defined as abrasion resistance. Whitening resistance: The film was gently wound several times around a cylinder having a radius of 6 mm, and the degree of whitening of the surface was visually checked in that state.

The evaluation results are shown in Tables 1 to 3.

[0021]

[Table 1]

[0022]

[Table 2]

[Table 3] First, as shown in Table 1, in Example 1 relating to the resin composition of the present invention, all of the flame retardancy, the heat deformation resistance, the whitening resistance, and the flexibility were good. The wear resistance is also the target value of 3
The characteristic value was much higher than 00 times and good tensile strength and elongation were obtained.

On the other hand, in Comparative Examples 1, 2, 3, and 5 in which no polyamide resin was used for the outer layer, the abrasion resistance, the tensile strength, and the heat deformation rate were significantly reduced.

In Comparative Example 3 in which a resin other than the polypropylene / polybutene alloyed resin was used for the inner layer, flexibility, which is a property required for the inner layer resin, was insufficient. When the amount of the metal hydroxide in the inner layer is small as in Comparative Example 6,
Insufficient flame retardancy of electric wires. In addition, when the amount of metal hydroxide in the outer layer resin is increased in order to ensure flame retardancy, flame retardancy is improved, but characteristics such as wear resistance and tensile strength are reduced (Comparative Example 5). Conversely, if the amount of metal hydroxide in the inner layer is too large as in Comparative Example 7, the flame retardancy is improved, but the abrasion resistance, tensile strength, flexibility and the like are reduced. further,
When the thickness dimension ratio of the inner layer and the outer layer is 4/6 or less, the flexibility of the insulated wire is insufficient (Comparative Example 4), and conversely, 9/1.
Above, the wear resistance and tensile strength are insufficient (Comparative Example 8).

[Brief description of the drawings]

FIG. 1 is a sectional view of an insulated wire.

[Explanation of symbols]

 1: Copper core wire (conductive core wire) 2: Inner layer 3: Outer layer

Claims (1)

[Claims] 1. An insulated wire in which an outer periphery of a conductive core wire is coated with an insulating layer composed of an inner layer and an outer layer, wherein the inner layer contains 50 to 400 parts by weight of a metal hydroxide with respect to 100 parts by weight of a polypropylene / polybutene alloyed resin. And the outer layer is made of a polyamide resin, and the thickness dimension ratio of the inner layer and the outer layer is defined as inner layer / outer layer =
An insulated wire having a ratio of 6/4 to 9/1.