JPH06234889A - Abrasion-resistant composition and electric wire using the same - Google Patents

Abstract

PURPOSE:To provide an abrasion-resistant composition having flame resistance, not generating a hydrogen halide on its combustion, excellent in abrasion resistance, and capable of being dyed into multicolors, and to provide an electric wire using the same. CONSTITUTION:An abrasion-resistant composition characterized by adding 30-200 pts.wt. metal hydrate to 100 pts.wt. high density polyethylene having a density of >=0.94 and the weight-average mol.wt./number-average mol.wt. ratio of >=5, or an abrasion-resistant composition characterized by adding 0.5-50 pts.wt. functional group-containing polyolefin resin to the above-mentioned composition, and an abrasion-resistant electric wire having a coating layer comprising the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for transportation means such as automobiles and ships, and industrial machines such as elevators and robots. It is particularly flame-retardant, but it produces toxic gas and smoke even when incinerated. The present invention relates to a wear-resistant composition that can be suppressed, and a wear-resistant electric wire having a coating layer of the composition.

[0002]

2. Description of the Related Art As a covering material for electric wires for automobiles, for example, an insulating material containing polyvinyl chloride as a main component, which is a mixture of a polyvinyl chloride resin with a filler, a plasticizer, a stabilizer and the like, is often used. However, since such halogen-containing materials generate harmful hydrogen halide gas or generate a large amount of smoke when burned, there is a problem from the viewpoint of the impact on the human body and the environment in the event of a fire or disposal. It has become to. For this reason, for example, it is desired to recover and reuse the insulating material without incinerating the automobile electric wire after scrapping the vehicle.

However, since electric wires for automobiles have thin wires and wires of different lengths that are complicatedly laid inside the vehicle body, only the electric wires are separated when the automobile is dismantled, and insulation containing polyvinyl chloride that generates toxic gas is generated. It is very difficult to recover and reuse the material. In reality, when the automobile is disposed of, these electric wires are often disposed of by incineration or landfill. If a large amount of polyvinyl chloride is incinerated, the problem of air pollution will be directly caused by the hydrogen chloride gas, and the treatment cost will increase. Also, even if it is landfilled, the cost is high nowadays due to the serious land shortage,
It cannot be continued in the future. In addition, as securing a new landfill site will lead to environmental damage, this problem will become more serious today as the number of scrapped vehicles reaches a huge number.

On the other hand, for cables and electric wires used in public buildings and the like, from the viewpoint of disaster prevention measures, it has been difficult to use an insulating material which does not generate hydrogen halide during combustion and produces a small amount of smoke. Flammable wires have been developed. As such an insulating material, for example, in JP-A-51-46341, aluminum hydroxide, magnesium hydroxide or a composite of magnesium hydroxide and magnesium carbonate is blended with a thermoplastic resin, and a carbon fine powder is further added. Additive compositions are disclosed. JP-A-57-92037 discloses a composition in which a hydrate of an inorganic metal compound and a red phosphorus flame retardant are added to a polyolefin resin.

[0005]

These compositions are insulating materials that impart flame retardancy to electric wires and do not generate hydrogen halide during combustion. However, when these insulating materials are coated on a conductor to form an electric wire for an automobile, the coating is remarkably damaged due to friction with the vehicle main body or parts during assembly or friction with the vehicle main body or another electric wire during use. There was a risk of wear. As described above, the electric wire using the flame-retardant insulating material is inferior in abrasion resistance required for the electric wire for automobiles.

Further, since carbon fine powder is added to the composition disclosed in JP-A-51-46431, an electric wire coated with this material becomes black, and coloring with another color is not allowed. Very difficult. Insulated electric wires of small diameter used for automobiles, robots, elevators, etc. need to be multicolored for identification, and from this point also, the above-mentioned material containing carbon fine powder is unsuitable.

[0007]

The present invention solves the above-mentioned problems and is flame retardant, while it does not generate hydrogen halide during combustion, has excellent abrasion resistance, and is capable of multicoloring. A high wear resistance composition and an electric wire using the same, characterized by high density polyethylene having a density of 0.94 or more and a weight average molecular weight to weight average molecular weight ratio of 5 or more 1
Abrasion resistant composition in which 30 to 200 parts by weight of metal hydrate is added to 00 parts by weight, or abrasion resistant composition in which 0.5 to 50 parts by weight of a polyolefin resin containing a functional group is added to the above composition And wear resistant wires comprising a coating layer of these compositions.

[0008]

The high density polyethylene used in the present invention imparts abrasion resistance to the composition. The ratio of the weight average molecular weight to the number average molecular weight represents the degree of the molecular weight distribution of the polydisperse polymer compound. In the present invention, this ratio is 5
With the above, excellent molding characteristics are secured. This is considered to be because when the molecular weight distribution of high-density polyethylene is wide, the low molecular weight region acts as a processing aid during extrusion molding. For this effect, a single resin may be used, two or more kinds of high-density polyethylene may be mixed, and at least either linear low-density polyethylene or low-density polyethylene may be mixed. If the ratio of the weight average molecular weight to the number average molecular weight is 5 or less, the moldability becomes poor.

The metal hydrate acts as a flame retardant. As the metal hydrate, aluminum hydroxide, magnesium hydroxide,
Examples thereof include calcium hydroxide and a mixture thereof. These metal hydrates may be used alone, or may be surface-treated with a fatty acid, a silane coupling agent, a phosphoric acid ester or the like. . The amount of metal hydrate added is 30
~ 200 parts by weight means that if the addition amount is less than 30 parts by weight, a sufficient flame retardant effect cannot be obtained, and if it exceeds 200 parts by weight,
This is because the moldability of the composition and the mechanical strength such as breaking strength and abrasion resistance are reduced.

As with the metal hydrate, red phosphorus can be used as a flame retardant. When the above metal hydrate and red phosphorus are used in combination, a higher flame retardant effect is brought about by the synergistic effect. It is desirable to add 50 parts by weight or less,
When it exceeds the weight part, the moldability of the composition and the mechanical strength such as breaking strength and abrasion resistance decrease.

The polyolefin-based resin containing a functional group enables high-density polyethylene to be mixed with high density polyethylene such as magnesium hydroxide and red phosphorus, which are flame retardants, without lowering the mechanical strength. The functional group refers to an acid anhydride, a carboxylic acid, a carboxylic acid metal salt, a carboxylic acid ester, an epoxy ring, and an isocyanate, which is contained in an amount of 0.1 to 5.0% by weight based on the polyolefin resin. The content of these functional groups is 0.1 to 5.0% by weight,
This is because if it is less than 0.1% by weight, the effect of addition is not sufficient, and if it exceeds 5% by weight, the functional group reacts with water due to moisture absorption and becomes extremely hard.

The addition amount of the polyolefin resin containing a functional group is set to 0.5 to 50 parts by weight, because the addition effect is not sufficient if the addition amount is less than 0.5 parts by weight, and the composition is exceeded when it exceeds 50 parts by weight. This is because the mechanical strength such as moldability and wear resistance of the product is reduced.

In addition to the above, the anti-aging composition, antioxidant, vulcanizing agent, vulcanizing agent, plasticizer, coloring agent, lubricant, flame retardant auxiliary agent and the like are added to the wear resistant composition of the present invention in appropriate amounts. Of course, it can be added.

By coating a conductor with the above-mentioned abrasion resistant composition of the present invention, it is possible to provide an electric wire having excellent molding characteristics, flame retardancy and abrasion resistance.
Moreover, since the above composition does not contain a halogen compound,
Even if it is incinerated, it does not generate hydrogen halide and emits a small amount of smoke. Further, since the above composition does not contain carbon, it can be colored by adding a coloring agent or the like, and the electric wire coated with this composition can be multicolored.

[0015]

[Example] Seven annealed copper wires having a diameter of 0.32 mm were twisted to form a conductor cross-sectional area of 0.5 mm ^2, and the materials shown in Tables 1 and 2 were extrusion-coated to a coating thickness of 0.3 mm to form an automobile electric wire. I made a prototype.
Figure 1 is a cross-sectional view of the prototype wire, 1 is a twisted conductor,
2 is a coating layer of an insulating material.

[0016]

[Table 1]

[0017]

[Table 2]

1 to 9 in Table 1 use the composition of the present invention, 1 to 7 in Table 2 indicate that the composition ratio is outside the range of the present invention, and the conventional polyvinyl chloride composition in the conventional examples. The thing using the thing is shown. These prototype electric wires were evaluated for appearance after extrusion, abrasion resistance, breaking strength, flame retardancy, and hydrogen chloride generation amount during combustion.

The test method is as follows. Abrasion resistance : As shown in FIG. 2, a load of 714 gf is applied on the wire sample 3 of about 10 cm, and a metal rod 4 of 0.5 mmφ is placed orthogonally thereto. Then, the metal rod 4 is moved at a speed of 60 reciprocations for 1 minute to wear the electric wire sample. The number of reciprocations of the metal rod 4 until the metal rod 4 and the conductor of the electric wire sample 3 were electrically connected was defined as the abrasion resistance index. This index should be 300 or more. Breaking strength: According to JIS C 3005. Tensile strength is 16
More than MPa is desirable. Flame-retardant: Hold a wire sample of about 30 cm horizontally, make a reducing flame of Bunsen burner indirect in the central part of the wire sample for 30 seconds, then gently remove the flame and measure the afterflame time and spread length. . For flame retardancy, it is desirable to extinguish itself and not spread fire. Hydrogen chloride generation rate: According to JCS C53.

As a result of the above evaluation, the examples of the present invention shown in Tables 1 to 9 are the comparative examples of Tables 1 to 7 and the conventional PV.
Compared to C electric wire, it has excellent extrusion appearance, wear resistance, breaking strength, and flame retardancy. Further, the electric wire according to the present invention does not generate hydrogen chloride gas during combustion.

[0021]

As described above, the wear resistant composition of the present invention has excellent flame retardancy and good wear resistance.
Since it can be multicolored, it can be remarkably extended in life by being applied to electric wires which are constantly rubbed with each other, such as an electric wire for an elevator, an electric wire for a robot, and an electric wire for an automobile harness. Further, since it has a safe burning performance without generating harmful gas, it can be used for wiring in a densely crowded area or in a dense room to ensure safety.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric wire formed in an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method for abrasion resistance test of an electric wire.

Claims (3)

[Claims] 1. A high-density polyethylene 100 having a density of 0.94 or more and a ratio of the weight average molecular weight to the number average molecular weight of 5 or more.
A wear-resistant composition, characterized in that 30 to 200 parts by weight of a metal hydrate is added to parts by weight. 2. A high-density polyethylene 100 having a density of 0.94 or more and a ratio of the weight average molecular weight to the number average molecular weight of 5 or more.
A wear-resistant composition comprising 30 to 200 parts by weight of a metal hydrate and 0.5 to 50 parts by weight of a polyolefin resin containing a functional group, based on parts by weight. 3. A wear-resistant electric wire comprising a coating layer of the wear-resistant composition according to claim 1 or 2.