JPH08195128A - Flame-resistant insulated electric wire - Google Patents

Abstract

PURPOSE: To provide a flame-resistant insulated electric wire having excellent abrasion resistance and terminal workability and generating no corrosive halogenous gas at the time of burning. CONSTITUTION: This flame-resistant insulated electric wire is covered with an inner layer insulator 2 and an outer layer insulator 3 on a conductor 1. The inner layer insulator 2 is formed with a resin composition mixed with calcium carbonate 50-250 pts.wt. to polyolefin 100 pts.wt. The outer layer insulator 3 is formed with a resin composition mixed with a metal hydroxide 30-150 pts.wt. to a blended material 100 pts.wt. of polyolefin and unsaturated carboxylic acid or the polyolefin denatured by its derivative.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant insulated wire which has excellent wear resistance and end workability and does not generate a corrosive halogen-based gas when incinerated.

[0002]

2. Description of the Related Art Conventionally, the insulation of wire harness wires used in electric and electronic circuits of passenger cars, home appliances, etc.
Polyvinyl chloride (PV with excellent insulation and processability
C) is often used.

However, this polyvinyl chloride (PV
C) generates corrosive halogen-based gas when incinerated, and heavy metals such as lead and antimony added as stabilizers and flame retardant aids remain in the combustion residue, and after these are buried,
It is feared that there will be adverse effects on the environment, such as runoff from rainwater and pollution of rivers.

Therefore, recently, as an electric wire insulator, polyvinyl chloride (PV) is apt to generate such harmful substances.
Instead of C), the use of a non-halogen flame-retardant material in which a metal hydroxide is mixed with polyolefin is being considered.

[0005]

However, such a halogen-free flame-retardant material is a polyvinyl chloride (PV).
In addition to being inferior in wear resistance to C), when the insulator covered by the terminal is crimped for crimping the terminal, the insulator is not completely removed and is likely to remain on the conductor. It was a hindrance to terminal processing.

Therefore, the present invention has been devised to solve the above problems, and its object is to generate a corrosive halogen-based gas when incinerated, which has excellent wear resistance and end workability. Not to provide a new flame-retardant insulated wire.

[0007]

In order to achieve the above object, the present invention provides a flame-retardant insulated wire in which a conductor is coated with an inner layer insulator and an outer layer insulator. 5 parts by weight of calcium carbonate
The resin composition is mixed with 0 to 250 parts by weight, and the outer layer insulator is formed by adding a metal hydroxide to 100 parts by weight of a blend of a polyolefin and a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof. Thirty
~ 150 parts by weight of the resin composition mixed.

The polyolefin used in the present invention is
Ultra low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, ethylene butene copolymer and the like can be mentioned, and these may be used alone or in combination of two or more kinds.

The calcium carbonate used as the filler for the inner layer insulator may be surface-treated with a fatty acid, a silane coupling agent, a resin acid, a cationic activator or the like, and the admixing amount is 50 to 250 parts by weight with respect to 100 parts by weight of the polyolefin. And That is, if the mixing amount is less than 50 parts by weight, the desired end workability cannot be improved, and if it exceeds 250 parts by weight, the wear resistance is significantly impaired.

On the other hand, the polyolefin modified with an unsaturated carboxylic acid or a derivative thereof is a polyolefin which is copolymerized or graft modified by reacting an unsaturated carboxylic acid or a derivative thereof with a polyolefin during or after the polymerization of the polyolefin. Examples of the polyolefin include polyethylene, polypropylene, polybutene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl acrylate, ethylene propylene rubber and ethylene butene copolymer.

Examples of the unsaturated carboxylic acid include acrylic acid, maleic acid, fumaric acid and the like, and examples of the derivative thereof include metal salts of the above unsaturated carboxylic acids, amides,
There are esters and anhydrides, and maleic anhydride is most preferred.

In the present invention, the mixing ratio of the polyolefin and the polyolefin modified with the unsaturated carboxylic acid or its derivative is not particularly limited, but the weight ratio is 99/1 to 99%, respectively.
A range of 70/30 is preferred.

Examples of metal hydroxides include aluminum hydroxide, magnesium hydroxide, hydrotalcite, calcium aluminate, calcium hydroxide, and the like.
Among them, magnesium hydroxide having the highest flame retardant effect is preferable. From the viewpoint of improving wear resistance, these metal hydroxides are preferably surface-treated with a fatty acid, a silane coupling agent, a titanate coupling agent or the like, and among them, a silane coupling agent is particularly preferable. The silane coupling agent is represented by the following chemical formula 1.

[0014]

[Image Omitted] (R) n-Si- (X) 4-n R: Functional group that reacts with organic matter X: Group that binds with inorganic matter (chloro group, methoxy group, ethoxy group, methoxyethoxy group, etc.) n: 1 In natural number 1 to 3, vinyl as R, methacryloxy,
There are phenyl-based, epoxy-based, amino-based, mercapto-based, etc., but especially vinyl-based and methacryloxy-based surface treatment effects are remarkable. Vinyl-based silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, and methacryloxy-based γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltrisilane. There are ethoxysilane and the like.

The amount of the silane coupling agent added is arbitrary, but it is preferably treated in the range of 0.5 to 3% by weight with respect to the metal hydroxide. The surface treatment method of this silane coupling agent is a method of directly adding it during compounding, or a method of treating the surface of the metal hydroxide.
There are two ways, but the latter is more effective. In the case of surface-treating a metal hydroxide, the silane coupling agent is diluted with an organic solvent such as alcohol or acetic acid water, and then sprayed on the metal hydroxide powder or added to the water slurry. Is common. The metal hydroxide thus surface-treated may be used in combination with another surface-treatment such as fatty acid or phosphoric acid ester.

The amount of the metal hydroxide mixed is 30 to 30 parts by weight based on 100 parts by weight of the total amount of the polyolefin and the polyolefin modified with the unsaturated carboxylic acid or its derivative.
150 parts by weight is preferred. That is, if the mixing amount is less than 30 parts by weight, the desired flame retardancy cannot be imparted,
Also, if it exceeds 150 parts by weight, the wear resistance is significantly impaired.

In the present invention, in addition to the above components, a crosslinking agent,
Antioxidants, copper anti-corrosion agents, lubricants, pigments, nucleating agents, etc. may be added as appropriate, and a composition composed of these may be subjected to electron beam irradiation or the like for crosslinking.

[0018]

According to the present invention, as described above, the insulator coated on the conductor has a two-layer structure composed of the inner layer insulator and the outer layer insulator, and each insulator is formed from the resin composition as described above. As a result, a flame-retardant insulated wire excellent in wear resistance and terminal processability can be obtained. That is, since the inner layer insulator that is in direct contact with the conductor has excellent releasability, the terminal processability is improved, and the outer layer insulator exhibits excellent wear resistance.

[0019]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

An insulating material composed of the blended components shown in each column of Tables 1 and 2 was used on a conductor 1 having a core wire outer diameter of 2.6 mmφ as shown in FIG. 1 using a 40 mm extruder set at 220 ° C.
The thickness ratio of the outer layer insulator 3 and the inner layer insulator 2 is 1 respectively.
A plurality of sample electric wires were prepared by extrusion coating so as to be / 9 to 4/6. At this time, the insulating material shown in Table 1 was used as the outer layer insulator 3, and the insulating material shown in Table 2 was used as the inner layer insulator 2. Then, thereafter, the following evaluations were performed on these various sample electric wires.

[0021]

[Table 1]

[0022]

[Table 2]

(1) Abrasion resistance According to JASO-D611, as shown in FIG. 2, a weight of 1350 g was measured so that a sample electric wire having a length of 90 mm was in contact with abrasion tape No. 150G specified in JIS-R6251. After adding and fixing, 4 points per sample were read from the tape at a speed of 1500 mm / min, and the average value was evaluated.

(2) Flame retardance According to JASO-D608-87, a sample 300 mm was supported horizontally, and the afterflame time was measured after a reducing flame of a Bunsen burner was applied for 10 seconds. And the afterflame time is 30
The test was judged to be acceptable within 2 seconds and to be unacceptable for more than 30 seconds.

(3) Terminal Machinability A 3.0 mmφ blade of a wire stripper made by Vessel is applied to the position of 10 mm from the end of the sample of 30 cm to peel off the insulator, and thereafter, as shown in FIG. The work of measuring the extended length L was carried out at 10 points for each sample, and those having an elongation of 1 mm or less were passed, and the others were rejected.

[0026]

[Table 3]

As a result, as shown in Table 3, Examples 1 and 2 according to the present invention both had excellent wear resistance and flame retardancy, and had good end workability.

On the other hand, in Comparative Example 1 in which the polyolefin modified with the unsaturated carboxylic acid or its derivative was not added, the abrasion resistance was significantly lowered, and JASO-D61 was used.
It did not satisfy 1 cm or more of 41 cm. Further, in Comparative Examples 2 and 3 in which the amount of the metal hydroxide mixed was out of the specified range of the present invention, the flame retardancy of the former and the wear resistance of the latter were significantly lowered. In addition, Comparative Example 4 in which the filler of the present invention outside the specified value of the present invention is used for the inner layer insulator, and Comparative Example 5 in which the amount of calcium carbonate mixed is less than the limit value of the present invention are both insulators during terminal processing The elongation was large and the terminal processability was insufficient. Further, in the case of Comparative Example 6 in which the amount of calcium carbonate mixed exceeded the specified value of the present invention, the wear resistance was significantly reduced.

[0029]

In summary, according to the present invention, it goes without saying that a highly corrosive halogen gas is not generated during incineration.
It has excellent effects such as excellent wear resistance and end workability.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing an embodiment of a flame-retardant insulated wire according to the present invention.

FIG. 2 is a schematic diagram relating to an abrasion resistance test used in this example.

FIG. 3 is a schematic view of a terminal processability test used in this example.

[Explanation of symbols]

 1 conductor 2 inner layer insulator 3 outer layer insulator

Claims (3)

[Claims] 1. A flame-retardant insulated wire in which a conductor is coated with an inner layer insulator and an outer layer insulator, the inner layer insulator comprising:
A blend 100 comprising a resin composition in which 50 to 250 parts by weight of calcium carbonate is mixed with 100 parts by weight of polyolefin, and the outer layer insulator is a polyolefin and a polyolefin modified with an unsaturated carboxylic acid or a derivative thereof. 30 parts by weight of metal hydroxide to parts by weight
A flame-retardant insulated electric wire, which is formed of a resin composition mixed in an amount of up to 150 parts by weight. 2. The flame-retardant insulated wire according to claim 1, wherein the metal hydroxide is surface-treated with any one of a fatty acid, a silane coupling agent and a titanate coupling agent. 3. The flame-retardant insulated wire according to claim 1, wherein the thickness ratio of the outer layer insulator to the inner layer insulator is 1/9 to 7/3.