JP2002124139A - Abrasion and flame resistant insulation cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasion and flame resistant insulation cable using a non-halogen flame resistant component for an insulation layer having an abrasion resistibility equal to or higher than that of polyvinyl chloride resin component. SOLUTION: An insulation layer 2 of the abrasion and flame resistant insulation cable 10 is made of a flame resistant component, which contains magnesium hydroxide with BET specific surface area of 10-50 m2/g, with the ratio of 50-200 weight part against 100 weight part of the polyolefin resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-resistant insulated wire used for automobiles, and more particularly to a flame-resistant insulated wire having excellent wear resistance.

[0002]

2. Description of the Related Art Conventionally, it is important that an insulated wire mounted on an automobile has excellent wear resistance against vibration when mounted on an automobile and also has flame retardancy. As a flame-retardant composition with excellent heat resistance, it is added to polyvinyl chloride resin, which itself has flame retardancy, by adjusting the type and amount of plasticizer and filler according to the required properties of abrasion resistance A polyvinyl chloride resin composition is used.

[0003]

However, this polyvinyl chloride resin composition is excellent in flame retardancy, but has a drawback that a corrosive halogen-based gas is generated during combustion. Therefore, in recent years, as an insulating material used for an insulated wire, a halogen-free non-halogen flame-retardant composition has been studied. This composition is obtained by adding a metal hydroxide as a flame retardant to a polyolefin resin, but in order to give this composition the same flame retardancy as a polyvinyl chloride resin composition, a metal While it is necessary to add a large amount of hydroxide, adding a large amount of metal hydroxide has a disadvantage that abrasion resistance deteriorates.

As an improvement over this drawback, Japanese Patent Application Laid-Open No.
There is a non-halogen flame-retardant composition disclosed in Japanese Patent No. 283030. This composition is a composition obtained by adding a metal hydroxide surface-treated with a silane coupling agent to a blend of a polyolefin resin and a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof. The abrasion resistance is improved by firmly adhering the polyolefin resin and the metal hydroxide by the convenience of the derivative-modified polyolefin and the silane coupling agent.

However, although the halogen-free flame retardant composition has improved abrasion resistance as compared with the conventional halogen-free flame retardant composition, it has not been improved as much as the conventional polyvinyl chloride resin composition. .

Accordingly, an object of the present invention is to provide a wear-resistant flame-retardant insulated wire using a non-halogen flame-retardant composition having an abrasion resistance equal to or higher than that of a polyvinyl chloride resin composition for an insulating layer. .

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive studies to improve the adhesion between the polyolefin resin and the metal hydroxide, and as a result, have found that the metal added to the polyolefin resin can be improved. It has been found that by using a hydroxide having a specific surface area within a certain range, the wear resistance is remarkably improved, and the present invention has been completed.
That is, according to the first aspect of the present invention, the insulating layer contains 50 to 20 magnesium hydroxide having a BET specific surface area of 10 to 50 m ² / g with respect to 100 parts by weight of the polyolefin resin.
It is formed by a flame retardant composition containing 0 parts by weight.

[0008]

<Embodiment> A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a wear-resistant flame-retardant insulated wire according to a first embodiment of the present invention.

As shown in FIG. 1, a wear-resistant flame-retardant insulated wire 10 according to this embodiment has a conductor portion 1 such as a stranded wire.
And an insulating layer 2 covering the conductor portion 1.

The insulating layer 2 is formed of a non-halogen flame-retardant composition obtained by adding magnesium hydroxide as a metal hydroxide to a polyolefin resin.

As the polyolefin resin, polyethylene, polypropylene, a copolymer of ethylene and another α-olefin, an ethylene-vinyl acetate copolymer, ethylene ethyl acrylate, or the like is used alone or in combination of two or more. At this time, it is preferable to use polypropylene having a high melting point in consideration of heat resistance against heat generation during friction.

As disclosed in JP-A-6-283030, a small amount of a carboxylic acid or acid anhydride modified polymer may be added to the polyolefin resin,
A silane coupling agent may be added.

If necessary, an antioxidant, a processing aid, a softening agent, etc. may be added to the polyolefin resin. If heat resistance is required, a crosslinking agent, a crosslinking aid, etc. May be added, and heat crosslinking or electron beam crosslinking may be performed.

Magnesium hydroxide having a BET specific surface area of 10 to 50 m ² / g is used. This allows
The adhesion between the polyolefin resin and magnesium hydroxide, which is a metal hydroxide, is improved, and the wear resistance of the insulating layer 2 is significantly improved.

The amount of magnesium hydroxide added is preferably 50 to 200 parts by weight based on 100 parts by weight of the polyolefin resin. This is because if the amount is less than 50 parts by weight, the flame retardancy of the insulating layer 2 cannot be sufficiently exhibited.
If the amount exceeds 00 parts by weight, the cold resistance, the breaking strength and the breaking elongation are lowered, and it becomes impossible to endure practical use.

The metal hydroxide includes aluminum hydroxide, magnesium hydroxide, calcium hydroxide and the like. The use of magnesium hydroxide as the metal hydroxide to be added to the polyolefin resin is difficult when the BET specific surface area is 1%.
This is because the only metal hydroxide that can be 0 to 50 m ² / g is magnesium hydroxide. By the way, in Kyowa Chemical Industry Co., Ltd. made magnesium hydroxide (trade name skimmer) produced by the seawater method which is usually used as flame retardant,
The specific surface area is 4 to 7 m ² / g, and the BET specific surface area is 10
５０50 m ² / g of magnesium hydroxide can be obtained, for example, by hydrating magnesium oxide.

In this embodiment, the case where a stranded wire is used as the conductor portion 1 has been described, but the present invention is not limited to the stranded wire. For example, a rectangular conductor having a rectangular cross section or a conductor having a circular cross section may be used.

<Examples> Examples of the present invention and comparative examples will be described below. Table 1 shows the compositions of the insulating layers of the insulated wires according to Examples 1 to 4 and Comparative Examples 1 to 3.

[0019]

[Table 1]

As the insulated wires of Examples 1 to 4 and Comparative Examples 1 to 3, the conductor portion 1 was formed by twisting seven soft copper wires having a diameter of 0.32 mm into a copper stranded wire having an outer diameter of about 1.0 mm. At the same time, the insulating layer 2 was mixed with a material shown in Table 1 at a mixing temperature of 250 ° C. using a biaxial kneader to form a pellet-shaped composition using a pelletizer, and the composition was extruded using an extruder. Then, a material formed by extruding the conductor portion 1 to a thickness of 0.2 mm around the conductor portion 1 was prepared. The extrusion temperature at that time was 250 ° C.

The following tests were conducted on these insulated wires.

(1) As a test for elongation at break, JASO-
In accordance with D611-94 "Thin low-voltage wires for automobiles", the insulating layer 2 obtained by removing the conductor portion 1 from the covered electric wire was used as a tubular test piece, and measurement was performed at a pulling speed of 200 mm / min. Good elongation at break of 125% or more.

(2) As flame retardancy, JASO-D611
In accordance with −94, an insulated wire 300 mm as a material was horizontally supported, a reducing flame of a Bunsen burner was applied until it burned within 30 seconds, and a residual flame time after removing the flame was measured. A residual flame time of 15 seconds or less was judged as pass, and a flame of 15 seconds or longer was judged as rejected.

(3) JASO-D61 as wear resistance
In accordance with 1-94, an abrasion resistance test of the insulating layer was performed by a blade reciprocation method. The outline of the wear resistance test will be described with reference to FIG. 2. An insulated wire of a predetermined length is fixed on a test table 6, and a hard copper wire 5 provided at the lower end of the blade 3 is attached to the surface of the insulating layer 2 of the insulated wire. Is reciprocated along the longitudinal direction of the insulated wire while being pressed with a load of 7N, and the number of reciprocations until the insulating layer 2 is worn and the hard copper wire 5 comes into contact with the conductor portion 1 is measured. The contact between the hard copper wire 5 and the conductor 1 is detected by an ammeter connected between the blade 3 and the conductor 1. The number of reciprocations until the hard copper wire 5 came into contact with the conductor portion 1 was determined to be 300 or more.

The test results of the above (1) to (3) are also shown in Table 1. From these results, Examples 1 to 4 satisfied all of the elongation at break, flame retardancy, and abrasion resistance, whereas Comparative Examples 2 and 3 did not satisfy all of them.
As can be seen from the results, the insulated wires of Examples 1 to 3 are excellent in elongation at break, flame retardancy and abrasion resistance, and have the same abrasion resistance as the polyvinyl chloride resin composition of Comparative Example 1. Can be considered. Also, as in Example 4,
It can be considered that even if a small amount of magnesium hydroxide B is added to magnesium hydroxide A, the abrasion resistance is slightly reduced, but the level is not a problem.

On the other hand, the BET specific surface area is 7 m ² /
It can be considered that Comparative Example 2 in which g of magnesium hydroxide B was added did not have sufficient abrasion resistance, and Comparative Example 3 in which magnesium hydroxide was small had insufficient flame retardancy.

Accordingly, from these results, the wear-resistant flame-retardant insulated wire 10 of the present invention has sufficient characteristics and can be sufficiently replaced with a PVC insulated wire currently in use.

[0028]

According to the first aspect of the present invention, the insulating layer has a BET specific surface area of 10 to 5 on the polyolefin resin.
Since it is formed of a flame retardant composition to which 0 m ² / g of magnesium hydroxide is added, the adhesion between the polyolefin resin and magnesium hydroxide is improved, and the wear resistance of the insulating layer can be significantly improved. .

Further, by containing the magnesium hydroxide in an amount of 50 to 200 parts by weight based on 100 parts by weight of the polyolefin resin, the insulating layer is designed to sufficiently exhibit flame retardancy.

[Brief description of the drawings]

FIG. 1 is a sectional view of a wear-resistant flame-retardant insulated wire according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a blade reciprocating method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor part 2 Insulation layer 10 Wear-resistant flame-retardant insulated wire

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Koji Fujimoto 1-114 Nishisuehirocho, Yokkaichi-shi, Mie Sumitomo Wiring Systems, Ltd. (72) Inventor Masafumi Sato 1-114, Nishisuehirocho, Yokkaichi-shi, Mie Sumitomo (72) Inventor Jun Yoshimoto 1-14 Nishisuehiro-cho, Yokkaichi City, Mie Prefecture F-term (reference) 4J002 BB031 BB051 BB061 BB071 BB121 DE076 FD136 GQ01 5G313 AB03 AB09 AC02 AD03 AE02 AE07 5G315 CA03 CA04 CB02 CC08 CD02 CD14

Claims (1)

[Claims] The insulating layer is made of a polyolefin resin.
A wear-resistant flame-retardant insulated wire comprising a flame-retardant composition containing 50 to 200 parts by weight of magnesium hydroxide having a BET specific surface area of 10 to 50 m ² / g with respect to 0 parts by weight.